# Little Dot Tube Amps: Vacuum Tube Rolling Guide



## Dept_of_Alchemy

*Little Dot Tube Amps: Vacuum Tube Rolling Guide*​   
*[size=16.0pt]A quick introduction: Who is this guide for? (plus some background)[/size]*
   
  When I purchased my first Little Dot amplifier in 2005 I was in a position many of you are in now.  I was new to high end headphones, and curious about the ‘tube’ sound. Being a student at the time I wasn’t in the financial league to afford a high end tube amp, and I began to look for the best “bang for the buck” I could find in an intro level amp.  It was in that context that I purchased my first Little Dot amp and began my very satisfying journey through the world of tube rolling.  Setting aside a little time each week, the following guide and tube ratings are compiled from notes I made during listening sessions with a Little Dot MkIII fed by a HeadRoom Max DAC (lossless files from MacBook Pro via USB).  My reference headphone is the Sennheiser HD650 and all of the tubes I listened to are matched pairs unless otherwise noted.  The tube descriptions and ratings in this guide are observations from my own subjective experience and as we often say on this forum - your mileage may vary.  I hope you will find this guide a useful reference and have as much fun reading as I did while writing it. Please share your own tube rolling impressions in this thread.  Happy listening!
   
   
*[size=16.0pt]Which Little Dot amp is this guide for?[/size]*
   
  The tubes reviewed in this guide can be used in all current production (2011) LD tube amps.  If you are not sure which tube family works with your amp (including out of production LD amps), please refer to this list for more information or ask us in this thread.
   
       - DoA
   
   
*[size=24.0pt]-= Contents =-[/size]*
_[size=10.5pt][click on chapter titles to go there directly][/size]_
_[size=10.5pt][sections marked in red are incomplete][/size]_
  
*1. EF91 FAMILY*
  1.1 Overview
  1.2 Brimar EF91
  1.3 Mullard EF91/6AM6
  1.4 Mullard M8083/CV4014
  1.5 Telefunken 6AM6
   
*2. EF92 Family*
  2.1 Overview
  2.2 Ediswan EF92
  2.3 Mullard CV131/6CQ6
  2.4 Mullard M8161/CV4015
  2.5 MWT W77
  2.6 United Electron EF92
   
*3. EF95 Family*
  3.1 Overview
  3.2 Amperex 5654
  3.3 Chinese 6J1
  3.4 Collins 6AK5
  3.5 GE 5654
  3.6 GE 5Star 5654 (Gray plate)
  3.7 GE JAN5654W
  3.8 Mullard M8100 / CV4010
  3.9 RCA 5654
  3.10 Voshkod 6ZH1P-EV
  3.11 Sylvania 5654
  3.12 Sylvania Gold Brand 5654
  3.13 Tung-Sol 6AK5
  3.14 Western Electric 403B
  3.15 Westinghouse 5654
   
*4. Power Tubes*
  4.1 Overview
4.2 Chinese 6N6
4.3 Russian 6H6P
4.4 Russian 6H6P-I
4.5 Sovtek 6H30EB
4.6 Electro-Harmonix 6H30Pi Gold
4.7 6H30P-DR
   
*5. Conclusion*
  5.1 Can’t Decide Which Tube to Try?
  5.2 Online Tube Sellers
  5.3 Useful Links
   
  .


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## Dept_of_Alchemy

*[size=18.0pt]1.[/size][size=18.0pt]EF91 FAMILY[/size]*   
*1.1 Overview*
   
  Known for its linear and extended presentation in the top-end but sometimes suffering from ‘boombox’ bass, the EF91 family of signal tubes is a great choice for jazz aficionados looking for that crystal-clear treble and who prefer (or do not mind) looser-than-neutral bass. The EF91 draws significantly more current (300mA) compared to the EF92 (200mA) and EF95 (175mA) families and therefore tends to run hotter as a result. When considering rolling these tubes be aware that some users have reported distortion problems when using tubes from the EF91 family although I have never experienced that problem with both high and low impedance headphones in my LD MkIII setup using matched Russian 6H6P-I power tubes (I suspect EF91 distortion problems are caused by low quality or mismatched power tubes). Dip switches must be set in their correct positions in Mk-series amps before using this family of tubes.
   
  Also Known As: *EF91, 6AM6, CV138, M8083, CV4014, Z77, 8D3, HP6, 6F12*
   
*1.2 Brimar EF91*
   
  The first thing you’ll notice about this tube is its very unique bass signature. People who enjoy this sound would say that its bass sound is entertaining while perfectly reasonable people can also argue that it needs more control and texture. To be sure, this tube doesn’t produce a proper ‘audiophile’ bass but it is nevertheless exciting sounding and there isn’t another tube that produces bass quite like this. The Brimar needs a lot of burn-in and the bass tightens up noticeably after 20 hours. The mids are uninspired compared with some other tubes in this family but still an improvement over stock 6J1’s. This is a great jazz tube on account of its excellent treble response and listening to instrumentals with this tube is very enjoyable indeed.
                  Bass: 14
                  Mid: 10
                  Treble: 19
                  Detail: 18
                  Soundstage: 17
                  Total: 78/100
   
*1.3 Mullard EF91/6AM6*
   
  Typical of the EF91 family, this tube needs a lot of burn in and its sound matures over time. The decay in treble energy with cymbals is excellent as well as treble extension. Bass and midrange are unobtrusive but not brilliant. Not to be confused with the great sounding mil-spec Mullard M8083.
                  Bass: 15
                  Mid: 13
                  Treble: 18
                  Detail: 14
                  Soundstage: 16
                  Total: 76/100
   
*1.4 Mullard M8083/CV4014*
   
  It is immediately obvious from the first listen that this tube is clearly the class leader of this family. First visual impression of this mil-spec tube reveals that it is extremely well-built with solid top getter and a blue colored screen side getter. My matched pair has the large Mullard shield logo printed on the tube and is dual printed M8083 and CV4014. Compared to the other tubes in the EF91 family, this tube does not need much burn-in time, vocals are especially vivid and noticeably stand out from the instruments. The decay of treble energy is surprisingly realistic, and this tubes’ uncanny ability to express nuances in the treble frequencies makes listening to live jazz recordings with this tube a joy in itself. Overall the sound of this tube is very impressive, with the small caveat that it has a slightly loose bass typical of EF91 tubes.
                  Bass: 18
                  Mid: 17
                  Treble: 20
                  Detail: 18
                  Soundstage: 18
                  Total: 86/100
   
*1.5 Telefunken 6AM6*
   
  This tube shows up relatively rarely on the market and it took some persistence on my part to find two tubes, but since it bears the celebrated Telefunken badge I decided to include this tube in this guide for the sake of completeness. Disappointingly, this tube failed to meet my expectations and even though it performed admirably well in reproducing treble frequencies, the sound in other areas is noticeably worse than the Mullard M8083 reviewed above. This tube also suffers from a particularly severe case of ‘boombox’ bass which is very distracting to me. I have to mention also that mine is not a matched pair which probably influenced its soundstage score somewhat.
                  Bass: 13
                  Mid: 16
                  Treble: 20
                  Detail: 16
                  Soundstage: 15
                  Total: 80/100


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## Dept_of_Alchemy

*[size=18.0pt]2. [/size][size=18.0pt]EF92 Family[/size]*   
   
*2.1 Overview*
   
  The EF92 family tends towards a more neutral sound with an emphasis on great vocal presentation, but the sound quality can vary wildly between different manufacturers. This is the only family of driver tubes that can be used on the older (out of production) LDII+ and LDII++ models (see List of LD Amps).
   
  Also known as: EF92, 6CQ6, CV131, M8161, 6065, W77, V884, VP6, 6F21, 9D6
   
*2.2 Ediswan EF92*
   
  One of my least favorite EF92 tubes, this tube has a harsh ‘digital’ sound that makes it fatiguing to listen to and the perception of ‘haze’ impinges on vocal music making the sound a bit too edgy and lifeless. Bit of a personal story, I actually first acquired these as stock tubes with the now discontinued LDII+ (my first LD amp) and it helped spark my enthusiasm for tube rolling ever since I discovered just how much better my amp can sound by rolling in different tubes. I don’t know if Little Dot still ships amps with this tube but if you are currently listening to only this tube I would highly recommend for you to check out some of the other tubes reviewed in this guide, you will be pleasantly surprised.
                  Bass: 13
                  Mid: 13
                  Treble: 9
                  Detail: 10
                  Soundstage: 14
                  Total: 59/100
   
*2.3 Mullard CV131/6CQ6*
   
  These are very nice sounding tubes with a laid back character that feels like you’re sitting a few rows back from the center of a concert hall. Keeping with the typical Mullard family sound, these tubes emphasize warmth and fullness, a characteristic I find very complimentary for my collection of Grado headphones. Bass quality is excellent in terms of texture and nuance, this is toe-tapping bass without being overpowering. Overall these are very nice tubes with no obvious faults and much to love.
                  Bass: 17
                  Mid: 18
                  Treble: 16
                  Detail: 14
                  Soundstage: 16
                  Total: 81/100
   
*2.4 Mullard M8161/CV401*
   
  Focus is the word. This mil-spec version of the Mullard CV131 is one of the best sounding EF92 tubes around. It brings to the table all of the fine qualities of the Mullard CV131 and adds to it a background so extraordinarily quiet you will actually _notice_ the silence between notes. A low noise floor lets details stand out, and music with female vocals in particular is presented with a magical sense of focused intimacy that draws you in and makes you feel as if the singer is standing right next to you, singing into your ears with all the inflections and emotions preserved. Overall this tube is well balanced and ‘audiophile’ sounding and is one of my personal favorites.
                  Bass: 19
                  Mid: 18
                  Treble: 19
                  Detail: 20
                  Soundstage: 19
                  Total: 95/100
   
*2.5 MWT W77*
   
  This rare and little known tube made by Marconi Wireless Telegraph sounds like no other in my collection. Otherwise uninspired with noticeably loose bass that colors the mid-bass and vocal frequencies, this tube’s special redeeming feature lies with its dramatically SPACIOUS presentation of soundstage which makes those close mic’d recordings (you know the ones you can’t bear to listen to anymore ever since you upgraded your headphones) enjoyable to listen to once again. Recommended for close mic’d rock and roll and overtly forward classical music. 
                  Bass: 16
                  Mid: 13
                  Treble: 14
                  Detail: 10
                  Soundstage: 19
                  Total: 72/100
   
*2.6 United Electron EF92*
   
  This is one of my favorite EF92 tubes besides the M8161. A great jazz tube with clear highs that’s well extended to the upper registers combined with outstanding soundstaging giving a sense of environment beyond the music.
                  Bass: 16
                  Mid: 16
                  Treble: 18
                  Detail: 18
                  Soundstage: 20
                  Total: 88/100


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## Dept_of_Alchemy

*[size=18.0pt]3. [/size][size=18.0pt]EF95 FAMILY[/size]*   
*3.1 Overview*
   
  The EF95 family is the most versatile and widely available of the three families of tubes reviewed in this guide. I recommend beginning users to start tube rolling within this family because it has the most variety of manufacturers and models to choose from, and gives you the most sound for your money (particularly starting with the 6ZH1P-EV). Little Dot Mk-series amps are factory configured to use this family and the Darkvoice 332/3322 amps also use this tube exclusively.
   
  Also known as: EF95, 5654, 6AK5, 6J1, 6ZH1P, 403B, CV850, M8100, 6DL5, DP61, PM05
   
*3.2 Amperex 5654*
   
  First impression of these tubes came off a bit shy sounding at the 10 hour mark. With about 50 hours of burn-in time, the sound eventually matured and developed a good amount of detail without being overly bright or edgy. My main reservations about these tubes are its lack of bass ‘oomph’ and its upper-mids is too forward sounding and smothers the top-octave ‘air’, robbing the overall sound of a sense of immediacy.
                  Bass: 12
                  Mid 18
                  Treble: 15
                  Detail: 16
                  Soundstage: 12
                  Total: 73/100
   
*3.3 Chinese 6J1*
   
  Manufactured at the Shuguang factory in China, these tubes are sometimes used as stock driver tubes for lower end LD amps and can be found cheaply from various overseas sellers on eBay (usually not matched). Sonically, these tubes are too ‘bright’ from the beginning, bass is muddy and undefined and vocals are masked by overpowering treble notes (which improves a bit as the tubes burn in), but in the end these tubes failed to approximate the ‘Hi-Fi’ sound and just do not do justice to the otherwise great sounding LD amps.
                  Bass: 10
                  Mid: 11
                  Treble: 13
                  Detail: 13
                  Soundstage: 12
                  Total: 59/100
   
*3.4 Collins 6AK5*
   
  These hard to find tubes have smooth and full bodied bass, somewhat recessed mids and a good sense of imaging.  They have a peculiar ‘congested’ sound during complex passages such as full orchestral music and suffers from a smidge of sibilance.
                  Bass: 16
                  Mid: 13
                  Treble: 15
                  Detail: 12
                  Soundstage: 15
                  Total: 68/100
   
*3.5 GE 5654*
   
  GE is one of the most widely available manufacturer of the EF95 family of tubes and comes stock with many LD amps.  Sound quality is average with a more upfront in-your-face sound.  Listening to the notoriously close-mic’d Jack Johnson’s “On and On” can be a claustrophobic experience with these tubes due to its up front qualities but chamber music is complimentary.
                  Bass: 12
                  Mid: 15
                  Treble: 13
                  Detail: 13
                  Soundstage: 10
                  Total: 63/100
   
*3.6 GE 5Star 5654*
   
  These hand-picked broadcast quality tubes are surprisingly unlike the standard GE tubes. I like these tubes for their evenness and silence which really lets you focus your mind on the music, and their soundstage is even and expansive as long as you have a matched pair.  I find myself tapping my toes listening to music with these tubes.
                  Bass: 17
                  Mid: 16
                  Treble: 17
                  Detail: 19
                  Soundstage: 18
                  Total: 87/100
   
*3.7 GE JAN5654W*
   
  These military spec tubes really have a sense of quality construction about them.  The first thing I noticed about these tubes when they arrived is just how neat and solid its internals look.  Their sound doesn’t disappoint either with incredibly good treble extension, clarity and quietness that reminds me of the GE 5 Star tubes reviewed above.  Its upfront sound is in keeping with the GE family sound, violins sounded desperately beautiful with these tubes. In the bass department, PRAT and OOMPH are the first adjectives that come to mind. Compared to the Mullard M8100, these tubes are airier and their bass not as soupy.  These tubes also have exceptionally clean vocal and lends itself well to modern jazz recordings such as Eva Cassidy’s “Live at Blues Valley” where the reverb of the room is clearly audible.
                  Bass: 19
                  Mid: 19
                  Treble: 20
                  Detail: 18
                  Soundstage: 17
                  Total: 93/100
   
*3.8 Mullard M8100 / CV4010*
   
  The Mullard house sound is much warmer compared to the GE tubes reviewed above. The warm tone is especially complimentary to female vocals where sultry voices such as Norah Jones and Dianna Krell’s come across as positively seductive. With rock music, the full body bass has a visceral impact.  These tubes don’t have the sweetest treble of the EF95 family (that title goes to the 6ZH1P-EV), but they nevertheless manage to give the music a sense of presence and body. Trumpets and strings unfortunately don’t have the most prat or the most natural decay but these are sins of omission that I could happily live with.
                  Bass: 20
                  Mid: 20
                  Treble: 18
                  Detail: 18
                  Soundstage: 18
                  Total: 94/100
   
*3.9 RCA 5654 (Black Plate)*
   
  The first thing you will notice about these tubes is how solid their bass response is.  If Mullard bass is too warm for you then definitely give these RCA black plates a try.  RCA cranked these out by the thousands back in the day, and in my experience they are very easy to find.  These tubes have a nice soundstage presentation and are extraordinarily good for classical music.  The sound has good balance overall and improves with burn-in.  They have the great quality of getting out of the way of the music and are a great middle-of-the-road choice.
                  Bass: 19
                  Mid: 17
                  Treble: 16
                  Detail: 19
                  Soundstage: 16
                  Total: 87/100
   
*3.10 Voshkod 6ZH1P-EV*
   
  I first became intrigued about these Russian tubes when several head-fi members began posting wildly contradictory comments about them – so dissimilar were people’s impressions about these tubes that I just had to find out for myself what they really sound like.  After some research I discovered that many versions of this tube were manufactured in various factories in the former USSR, and by far the best sounding version is the Voshkod 6ZH1P-EV which was made for cold war rockets.  I got my matched pair from Yen Audio and first impression out of the package proved that in keeping with its military heritage, these tubes are some of the most solidly constructed tubes I’ve ever encountered. Sonically, these tubes pleasantly surprised me with their stunningly clear and transparent treble and authoritative sounding bass that compliments my HD650 as well as my Grados.  Vocals are similarly impressive with a level of realism that is what I love about the ‘tube sound’. These are my favorite EF95 tubes.
                  Bass: 19
                  Mid: 20
                  Treble: 19
                  Detail: 19
                  Soundstage: 18
                  Total: 95/100
   
*3.11 Sylvania 5654*
   
  Reserved sounding tube at first and needs burn in. Good balance of frequency extremes and good imaging. Effortless sound quality during complex passages, good decay of cymbals.
                  Bass: 16
                  Mid: 15
                  Treble: 17
                  Detail: 18
                  Soundstage: 18
                  Total: 84/100
   
*3.12 Sylvania Gold Brand 5654*
   
  These are the best tubes Sylvania made and are easy to identify as they have golden pins. They are warmer sounding than GE and RCA tubes, and have slightly better vocal than Mullards but sacrifice some bass performance. My matched pair required a lot of burn in and sounded much better after 20 hours or so. The thing that stands out about these tubes is their razor sharp 3D imaging, and their outstanding balance of detail and warmth without compromising either quality.
                  Bass: 16
                  Mid: 19
                  Treble: 18
                  Detail: 20
                  Soundstage: 18
                  Total: 91/100
   
*3.13 Tung-Sol 6AK5*
   
  The famed Tung-Sol has always been one of my favorite vacuum tube brands since day one of my tube rolling journey.  The Tung-Sol 6AK5 didn’t disappoint, offering a smooth laid back sound. It has the richness and sweetness of the Mullard midrange but with better frequency extension in the top end. If Mullards are too warm for you then give this tube a try.
                  Bass: 18
                  Mid: 18
                  Treble: 17
                  Detail: 19
                  Soundstage: 19
                  Total: 91/100
   
*3.14 Western Electric 403B*
   
  The WE 403B has long been the standard bearer of 403B tubes.  Unfortunately they suffer from microphonic issues and all 3 of my matched pairs have audible chime-like ringing during power cycles.  I really wanted to like them as WE has a good reputation, but extended listening to these tubes always caused fatigue to my ears due to a high frequency glare and sibilance.
                  Bass: 12
                  Mid: 12
                  Treble: 08
                  Detail: 15
                  Soundstage: 10
                  Total: 57/100
   
*3.15 Westinghouse 5654*
   
  These tubes really like instrumentals and has great PRAT with guitar and piano recordings.  Vocals are recessed sounding and anemic sounding bass make these a bad pairing for rock 'n roll music but they have their charm with jazz recordings.
                  Bass: 10
                  Mid: 12
                  Treble: 17
                  Detail: 17
                  Soundstage: 18
                  Total: 74/100


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## Dept_of_Alchemy

*[size=18.0pt]4. [/size][size=18.0pt]POWER TUBES[/size]*   
*4.1 Overview*
   
  The power tubes reviewed in this guide only applies to the current production Mk series amps. Unlike their impressive flexibility with signal tubes, most current production Little Dot amps can only accept 6N6/6H6P power tubes with the exception of the MkIV which can accept the 6H30Pi (for clarification refer to this chart).  It is important for the longevity and performance of your amp that the power tubes you use are matched pairs, otherwise it is common for power tubes and other components in the amp to fail pre-maturely due to badly matched tubes.  I have had several power tubes fail within 100 hours of use due to matching issues.


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## Dept_of_Alchemy

*[size=18.0pt]5. [/size][size=18.0pt]CONCLUSION[/size]*   
*5.1 Can’t Decide Which Tube to Buy?*
   
  To Little Dot’s credit, their Mk-series amps have an impressive number of tube rolling options and there are more than a few very informative threads dedicated to this topic.  I would recommend anybody interested in upgrading their stock tubes to take advantage of our collective knowledge and take a look at those threads.  Occasionally I have received PMs from new members who are overwhelmed by the sheer number of tube rolling options, and asked for my recommendations so they can stop reading forums and get back to listening to their music.  So here’s my short list: I would recommend the Voshkod 6ZH1P-EV as the best place to start as it is a clear upgrade from the stock tubes, followed by the Mullard M8083 for its impressive treble clarity and top-octave ‘air’ (provided you have matched power tubes). The RCA 5654 (black plate) is also a wonderful option for its solid all-around performance, great bass response and availability.
   
*5.2 Tube Sellers*
   
  I’m very picky about whom I purchase my tubes from, particularly about how they match and test their tubes as well as warranty periods. The following is a quick list of tube sellers that I have personally dealt with and have been happy with. There are certainly many more just a Google search away.
   
Yen Audio
TubeDepot
VacuumTubes.net
Thetubestore.com
   
*5.3 Useful Links*
   
  Intro to Tubes: http://www.head-fi.org/forums/f5/new-improved-tube-faq-newbies-119389/
  Little Dot Official Site: www.littledot.net
  Official Little Dot Dealer: http://shop.ebay.com/davidzhezhe/m.html?_trksid=p4340.l2562
   
   
  ----------------------------------------------------------------------------------------------------------------
  Version History:
  1.0 - 07/22/2011 - original post


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## Dept_of_Alchemy

.


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## FrankWong

This. Is. Amazing. 
	

	
	
		
		

		
			





 Thanks for the reviews, my impressions are mostly in line with what you said. Gonna find some more tubes to roll....


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## AlexRoma

Thanks for this guide. The %-tage measurement is a great idea indeed. Very good structure and user-friendly guide.
   
  I have a question though.. I own an MKIII. Would a power tube upgrade ( 6H30** series ) deliver more horse-power, not just better SQ  ?
   
  I need a little more power for my 600ohm bayers, so I have to decide, am I spending ~70$ on super-tubes, or am I selling the amp as it is, add another 70$ and buy the darkvoice 336 instead.


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## zero7525

Very nice assessment! Can you do a rating on the WE408A too?


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## shipsupt

Great post. Nice to see all this information summarized in one place. Thanks.


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## Dept_of_Alchemy

Quote: 





alexroma said:


> Thanks for this guide. The %-tage measurement is a great idea indeed. Very good structure and user-friendly guide.
> 
> I have a question though.. I own an MKIII. Would a power tube upgrade ( 6H30** series ) deliver more horse-power, not just better SQ  ?
> 
> I need a little more power for my 600ohm bayers, so I have to decide, am I spending ~70$ on super-tubes, or am I selling the amp as it is, add another 70$ and buy the darkvoice 336 instead.


 

 Thank you for your kind words. Looking at their data sheets, the stock 6N6P tube draws 750mA compare to the 6H30Pi which draws 850mA heater current, which is not much of a difference. Empirically I never noticed a volume difference between the two (I'm using matched Novosibirsk 6H6P-I in my amp which sounds good with my 300ohm Sennheisers). To get the most volume have you tried setting the jumpers to their highest gain setting (off/off)? I think the jumper settings would have the most impact for your situation than any power tube upgrades which is usually done to improve sound quality.
   
  - DoA


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## TMRaven

Quote: 





alexroma said:


> Thanks for this guide. The %-tage measurement is a great idea indeed. Very good structure and user-friendly guide.
> 
> I have a question though.. I own an MKIII. Would a power tube upgrade ( 6H30** series ) deliver more horse-power, not just better SQ  ?
> 
> I need a little more power for my 600ohm bayers, so I have to decide, am I spending ~70$ on super-tubes, or am I selling the amp as it is, add another 70$ and buy the darkvoice 336 instead.


 


  Are you saying they're not being driven to their optimal dynamism, or their volume level isn't as high as it should be?  I find the volume level part hard to believe, as I own the weaker MKII and on the highest gain setting, I rarely find myself putting the volume knob over 20% with my 600Ω 990s.  The volume knob was even lower when I had the stock power tubes in as well (6n6?) compared to my current ones (6H6N)


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## AlexRoma

Thanks for replay, guys.. Sorry for not mentioning the gain I had used before. It was mine mistake. In fact I had made everything possible to rise the volume. I've set gain 10 (off, off) from the very beginning , used ASIO for transport (which turns off OS mixer, rising the volume to it's maximum level). Looks like my crappy DAC/AMP (AudioGD NFB11) simply gives too little volume on RCA outputs (low gain), and I will not turn High Gain on, cause, I get noticed decrease of DAC fidelity. I do never use DT880's below 50% cause it's too boring, bass tends to disappear at all below 50% . I get optimum performance only when raising the bar to 65-70% (one o'clock). I can stand this volume level for a whole day, so I don't consider this level fatigue loud. 
   
  Little Dot MKIII is capable of pushing my DT880 (600) to pretty high volume indeed (on 90-100% load) but when it's pushed over 65% (1 o'clock), the background isn't silent any more.. There is a clear Hissss sound , never noticed below that level. I just want extra 100 mW so that I have never had to rise my volume higher then 50%. My power tubes are stock (6N6P), drive tubes - Mullard M8100 CV4010 . 
   
  I don't know which is the optimal dynamism of DT880's. I've listened these through 3 different amps (MKIII , M3, NFB11 stock amp). They all sound different but there were no night / day difference so that I could clearly point the right performance, or the one which is below optimum. 
   
*Update :* PROBLEM SOLVED buy repalcing power tubes with backup 6N6p pair. Looks like the were some true matched tubes previously, if both were running same half-dead.


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## Impulsive

awesome test!
  I knew Vohskods are hidden talent!
  As soon as i collect some money i will buy pair and since you said that tung-sols are a bit darker than Mullards M8100, i have to give them a try too.
  How about Voshkod vs M8100, warm vs dark?


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## mordy

Hi Dept of Alchemy,
   
  This tube rolling guide is amazing! I agree with almost everything there. Would be nice to add the Telefunken and Raytheon small mica EF95 tubes to the list. It is obvious that a huge amount of work and time went into this guide. Many thanks!
  Looking forward to the power tube reviews which are not included yet.
  The only thing left after this is to point out which combinations of power tubes and driver tubes work best.
  (From a different post: I found it noteworthy that the 6N6P power tubes tame the overpowering treble of some tubes and make them very listenable.)
   
  I am also questioning how important tube matching is, having heard that there are very large differences with a range of tolerance of up to 10% in the production lines. Another thing I do not understand is the statement in section 4.1 that power tubes failed after 100 hours due to mismatching. According to David of Little Dot the amplifiers are designed with totally separate circuits for right and left to the point that you can run different tubes simultaneously on each channel without causing any problems. Since I also had one of my OEM power tubes fail after five months (none of the driver tubes have failed during use yet), perhaps one has to conclude that the power tubes are more prone to failure than driver tubes.
   
  In your conclusion you recommend the RCA black plate 5654 tubes for "solid all-around performance, great bass response and availability." I could not agree more. Right now I am enjoying the RCA 5654 tubes I have from Aug 1959 (rectangular slanted getters) and Novosibirsk 6N6P 1975 tubes. This combination is wonderful in my system with better bass than the Mullard M8100/EF95 tubes and has a lively, dynamic, toe-tapping inducing presentation. The sound as I am writing this is positively intoxicating. Powerful, tuneful bass, a beautiful, mellow mid range, exquisite highs, tremendous detail and a glorious 3D sound stage.
  And for frugal people like me, I especially enjoy that all four tubes cost me $10.64 incl. shipping (even though I had to buy 9 RCAs and four 6N6Ps to get these prices).


----------



## john57

[size=medium]I really enjoy my EF91/CV4014 GEC tube (not review here) and it is quite a gem. I have ordered the EF92 United Electron EF92 tube based on your comments and I will see how my comments compare to yours.   [/size]


----------



## AlexRoma

Impulsive, Voshkod 6ZH1P-EV = mine 6J1P-EV .  The trick is getting the ones made from 1970 to 1980.
   
  Take in consideration, the tubes on ebay called 6ZH1P-EV are 10 times more expensive (30$ for a matched pair).
   
  Don't get tricked ! Get the set of 10 tubes 6J1P-EV's from 1970's for 20$ shipped.
   
  On the question how do these sound compared to M8100's, I had writen a lot before... For our  headphones, Mullards are better match. For Sennheiser -> Russians.


----------



## mordy

Hi AlexRoma,
   
  I have a pair of Voshkod 6Sh1P-EV tubes from 11/73. Are these identical to the 6ZH1P-EV / 6J1P-EV tubes?


----------



## Impulsive

thanks for experiences guys.
  I just wonder how is overall sound quality.
  After reading this, i am pretty sure i should give Voshkods and Tung-Sols a try.
  Voshkods, because of the best ranking here and Tung-Sols because of darker sound.
  That might be what i am looking for 
  Also thanks for explaining tubes names, price difference is incredible!


----------



## mordy

Hi AR,
   
  Found the answer:  *Zh* (Russian: *Ж*) - sharp-cutoff pentode. (also transliterated sh or j). It is the same exactly. Problem is that I don't like the sound - will burn them in an extra 100 hours and see...   
   
  Here is a link that will tell you all you want to know about Russian tube designations:
   
  http://en.wikipedia.org/wiki/Russian_tube_designations


----------



## john57

My United Electron EF92 tube came and after burn in it was a good EF92 tube and it matched some of the comments you made for it. I prefer the GEC EF91 tube. The GEC tube has far greater soundstage more depth rather than width like the United Electron. The GECC also has more dynamic range to work with and seems to be able to push the Russian 6N6P harder to higher output. My lowly MKll now seems to be new stronger model. It did had a bit of grain at first but it migrated out after a bit of tube burn-in. GEC has great resolving power and will show weakness in the audio chain. Well recorded material sounds great and in certain aspects match some of the sound characteristics in my Stax headphones setup.  
Cons: The GEC tube needs a long time to warm up time like at least 40 mins to bring out its characteristic sonic signature. Poor recordings or poor upstream devices can sound harsh because of the resolving power of the tube. My journey for the best driver tube for my Little Dot has ended on a very good note. 
I have just one more power tube to roll, A Russian 6N6P tube that has 10 mg of gold on the grid wires. I decided not to try the 6H30 DR tube since it is quite costly and I prefer to save the money to go to unamplified concerts. The gold Russian 6N6P is much cheaper and it just came in before the weekend and I will compare it with two of my other power tubes for the LD.


----------



## mordy

Hi John57,
   
  I have seen gold plated 6J1P tubes (with gold grid), but I was not aware of 6N6P tubes with gold grid. Could you give the reference where to buy them?
  Looking forward to hear about your experience with these power tubes.


----------



## john57

There was just a three day period that the gold 6N6P tubes were available from this vendor with just three matched pairs on sale. The tubes were in a cardboard box in a plastic bag. Lucky the tubes were not crushed. 
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=130542830285&ssPageName=STRK:MEWNX:IT
This may be the same vendor that you were talking about 6J1P having Gold-Platinum grids. The seller price seems quite reasonable and well documented. It takes about three weeks for shipment from Russian Federation. 
The gold girded 6N6P tubes are burning in as we speak. They are a bit heavier than the stock 6N6P and the heaters do not glow as brightly. I may start forming an opinion maybe late Sunday.


----------



## Dept_of_Alchemy

Quote: 





john57 said:


> My United Electron EF92 tube came and after burn in it was a good EF92 tube and it matched some of the comments you made for it. I prefer the GEC EF91 tube. The GEC tube has far greater soundstage more depth rather than width like the United Electron. The GECC also has more dynamic range to work with and seems to be able to push the Russian 6N6P harder to higher output. My lowly MKll now seems to be new stronger model. It did had a bit of grain at first but it migrated out after a bit of tube burn-in. GEC has great resolving power and will show weakness in the audio chain. Well recorded material sounds great and in certain aspects match some of the sound characteristics in my Stax headphones setup.
> Cons: The GEC tube needs a long time to warm up time like at least 40 mins to bring out its characteristic sonic signature. Poor recordings or poor upstream devices can sound harsh because of the resolving power of the tube. My journey for the best driver tube for my Little Dot has ended on a very good note.
> I have just one more power tube to roll, A Russian 6N6P tube that has 10 mg of gold on the grid wires. I decided not to try the 6H30 DR tube since it is quite costly and I prefer to save the money to go to unamplified concerts. The gold Russian 6N6P is much cheaper and it just came in before the weekend and I will compare it with two of my other power tubes for the LD.


 

 I'll be posting the power tube reviews shortly, just waiting for the gold Russian tubes to arrive. =)


----------



## john57

[size=medium]I had a surprising discovery in the power tube rolling with results that I was not expecting. Right now I am rechecking on the validity of my results with all of my headphones and other amps.  [/size]


----------



## mordy

Isn't this what keeps up the interest in tube rolling? You never know what you will find. Tubes are very mysterious.


----------



## G~mann

Hi DoA,
   
Your guide is comprehensive and insightful.  As I continue to explorer tube-rolling I am certain to refer to this guide for months to come.  I just received my pair of Mullen 8100s.  I must say the first impression (less 5hrs burn-in) is I can definitely tell a difference between them and the RCA 5654 tubes. 
   
The RCA tubes I bought already burnt-in with my LD MK-III a few weeks ago.  The RCAs bass is more prevalent, the highs crisp and more detailed.  I definitely won’t be throwing out these tubes.
   
Now, the Mullard is noticeably warmer even in its current stage of burn-in.  They have body and great depth.  The mids are slightly laid back.  I don’t really know if it is too laid back at times, it’s still too early to tell. No listener fatigue so far.  I’ve only listen to only a few albums so far – Bob James, Chris Botti, Karrin Allyson and Fiona Apple, but everything you’ve described of the Mullard is spot-on.  I will continue to explore it’s sound listening to additional artists and larger music genres.  These tubes are a great complement to the RCAs. 
   
The only doleful thought is knowing that as the tube ages and its sound matures they move closer to their death.  Too bad tubes cannot last forever.
   
  Thanks,


----------



## mordy

Hi G~M,
   
  From what I understand the average tube lasts around 2000 hours, which is quite a lot. The Russian tubes with the EV/EB rating are supposed to last 5000 hours. The Russian DR tubes are designed to last 10,000 hours.
  It is my impression that certain variants of tubes were designed to last 10,000 hours. Mullard had something called the M Series (I only saw EF95 type tubes from the M Series once on Ebay); the GE Five Star tubes are also supposed to last 10,000 hours.
  Recently I bought a pair of 5654 Amperex tubes made in Holland with the letters PQ, which stands for Premium Quality. These are also supposed to last 10,000 hours. Early listening to the PQ tubes is very promising, but I have to wait to form an opinion.
  The obvious answer to the question about tubes being used up is to buy several of your favorite tube.
  Part of the tube mystique and the fun of collecting tubes is that you sometimes find one tube in the US, and the exact match in Bulgaria!


----------



## G~mann

Hi Mordy,
   
  Thanks for the info.  I just received my 6J1P-EV set from Ebay yesterday.  This may be the same set of 10 tubes AlexRoma mentioned in his post selling for $20 shipped.  I am not to happy with them.  For one, the arrived unboxed  and many of the tubes have no apparent markings on them.  There is no way of verifying the manufacturer, make, year or anything else (that I am aware of). It sound like I'm talking about cars.   If I had to do it over again I would have bought a matched pair from a more reputable seller even at a higher cost.  I suppose I may put the other unused tubes on ebay. 
   
  I will likely keep one pair or two though.  The sound quality at the moment (6 hrs on burn-in) at clearly the worst of the three pairs I own (Mullards 8100\CV 4010 and RCA 5654)
  It sounds a bit harsh but to be fair I must allow more time for burn-in.  I did notice subtle improvement after 4 to 6 hours of use.
   
  Do anyone know or have the ability to match tubes?  I bought this set of ten but would be willing to either donate a pair or pay in exchange for having them matched.
   
  Thanks,


----------



## mordy

Hi G~M,
   
  Look, for $2/tube you cannot complain about the prize. I am a little surprised that the tubes did not have markings - that is not the norm, even with used tubes, although some of the markings may be faint. Most of the tubes I bought on the cheap did not come with individual boxes. My guess is that many of these Russian tubes come egg crated 100/box, so you would not expect individual boxes.
  In any case, AlexRoma pointed out that these tubes need a very long burn in, maybe 120 hours, to sound their best. Just be patient, and take your time. The tubes will sound much better after the long burn in, and I could understand how they could be a very good match for certain headphones.
  Personally, I prefer the Mullards, but I really like a good bass presence, and here the RCAs really shine.


----------



## eclipes

this is an excellent thread... keep the updates going... Endless tube shopping


----------



## benzoylmethyl

Awesome.  Thanks so much for this!  I just bought the hifiman ef2 and a set of mullard m8100s today.    I'm extremely excited to get into the world of tube rolling, even though I should probably have gotten a solid state first with my listening preferences...but i just love that tube look. 
   
  Would a set of Amperex 6AK5 be the same tube as the one you reviewed?  I'm looking for that mythical bass-happy Amperex tube that I keep hearing mentioned, and I think I may have found *one* set.  In Russia. And they're about $65 shipped...i don't want to pay that for a single set of tubes unless they're the ones I"m looking for.
   
  Thanks!


----------



## mordy

Hi Benzo,
   
  Before you overpay for the Amperex tubes, get a pair of 60's-70's RCA black plate tubes. These are plentiful, cheap, and have great bass. Again, my tube rolling experience is with the Little Dot MKIII, and I am not familiar with the Hifiman equipment and how it reacts to different tubes.


----------



## donluca

Your work is awesome DoA, I cannot thank you enough for all the mini-reviews you're written. 
   
  Can't wait for the power tubes review though!


----------



## john57

[size=medium]I am starting to wrap up my own power tube testing on my LD MkII. It took me some time since the EF91 GEC tube was so clear sounding with the power gold grid 6N6P tube. I had to readjust the setting on my Behringer SRC2496 DAC, which is the master DAC. It is now easy to hear the difference between 16, 20 and 24 bit internal processing option. I also can reliably tell the difference between line and internal clocking options. I also had to readjust the internal sampling rate on the SRC2496 for best clarity and it was not the same setting as before. The SRC2496 then feeds my slave DAC which is my brand new RDL HR DAC1 DAC by way of an AES connection between the two DACS. Both DACS uses XLR balanced outputs for which I use a conversion PylePro cable that switches the  XLR balanced outputs  to RCA outputs  to my two Little Dot amps. My slave RDL HR DAC1  DAC drives my Little Dot MKII.[/size]
   
  [size=medium]The gold grid 6N6P power tube is punchier and more dynamic sounding than my standard Russian 6N6P tube.  Both have good tonal range. The standard OTK 5 Russian 6N6P tube is a more relaxed and just a bit softer sounding tube than the gold grid Russian 6N6P. Both tubes are good, but the gold grid 6N6P tubes are hard to find. Both power tubes have great synergy with the EF91 CV4014 driver tube.[/size]
  [size=medium]On the other hand, the Sovtek 6H30 power tube is awful sounding. It was very thin sounding and had very little bass compared to the previous two tubes that I mentioned above.  The EF91 GEC tube, which is just a bit brighter from neutral, just makes matters worse with the Sovtek 6H30. The synergy was not there. [/size]
   
  [size=medium]I did not try the Electro-Harmonix 6H30Pi Gold tube but depending on what DoA finds on his power tube reviews I may revise my decision.[/size]
   
  [size=medium]I ran into another surprise. My Denon AH-D2000 headphones, which I was thinking of selling because  of the burry bass, huge recessed midrange, and peaky treble, were transformed by the GEC EF91 and the gold 6N6P power tube combination. The midrange came back and the bass sound much better. The sound stage on the Denon is now huge, even better than the Sennheiser HD 598. However, the Denon headphone at 32 ohms is showing a bit of a strain on my LD MKII amp and I am in process of doing  an experiment to see if I can make the Denon headphones to work even better.  [/size]


----------



## donluca

Wow, thanks for the insight John!
   
  Those output tubes are quite pricey on the bay, especially if you want them matched (which is rather important for output tubes).
   
  Where are you getting yours?


----------



## eclipes

Hey John
   
  I was wondering what DAC are you using? Because Im currently using the LD I+ with M8083 and can't figure which dac will be best paired with the combo.


----------



## mordy

Hi John57,
   
  Can you comment on how the sound is in your set up with the OEM 6N6Pi power tubes?
   
  My experience has been that with tubes with a lot of high frequency energy the 6N6P tubes sound better than the 6N6Pi. With this type of driver tube the 6N6P power tubes seem to bring out the bass better and make the top end sweeter.


----------



## john57

I am mostly getting them from Ebay because that is the cheapest I can get the Russian tubes from Bulgaria easily without being concerned about currency conversation using PayPal and Ebay buyer protection. Only $7.77 for a tested 6N6P NOS pair with the OTK 5 mark from lci_electronics. You can even get the Russian 6N6P tubes cheaper by buying in lots. The gold grids 6N6P version came from Ebay seller 4951511020. The ones I was using are the 1982 version. He also has the gold grid 6N6P 1978 version as well for a bit more. May take a month or more for delivery  

  
  Quote: 





donluca said:


> Wow, thanks for the insight John!
> 
> Those output tubes are quite pricey on the bay, especially if you want them matched (which is rather important for output tubes).
> 
> Where are you getting yours?


----------



## john57

Quote: 





eclipes said:


> Hey John
> 
> I was wondering what DAC are you using? Because Im currently using the LD I+ with M8083 and can't figure which dac will be best paired with the combo.


 


  
  [size=medium]I have two DACs listed in my previous post Behringer SRC2496 and RDL HR DAC1[/size]
   
  [size=medium]Are you using the Cowon J3 player? That is a good player that has good quality outputs as I understand it. Have you tried the optional Cowon AV cable and use the audio jacks directly into the Little Dot amp? That way you can use all the Cowon audio effects to the Little Dot. I would look at that idea first and see if it will work for you.  [/size]


----------



## john57

Quote: 





mordy said:


> Hi John57,
> 
> Can you comment on how the sound is in your set up with the OEM 6N6Pi power tubes?
> 
> My experience has been that with tubes with a lot of high frequency energy the 6N6P tubes sound better than the 6N6Pi. With this type of driver tube the 6N6P power tubes seem to bring out the bass better and make the top end sweeter.


 


 My original power tube was the [size=medium]Beijing 6N6 which I threw away once the new Russian 6N6P  came in. [/size]
  [size=medium]Thanks for your comment.  [/size]


----------



## donluca

Quote:


john57 said:


> I am mostly getting them from Ebay because that is the cheapest I can get the Russian tubes from Bulgaria easily without being concerned about currency conversation using PayPal and Ebay buyer protection. Only $7.77 for a tested 6N6P NOS pair with the OTK 5 mark from lci_electronics. You can even get the Russian 6N6P tubes cheaper by buying in lots. The gold grids 6N6P version came from Ebay seller 4951511020. The ones I was using are the 1982 version. He also has the gold grid 6N6P 1978 version as well for a bit more. May take a month or more for delivery


 


  Thanks for the info!
   
  I've bought some tubes from 4951511020, but didn't see that he had the 6n6p as well because they weren't under the category "output tubes" :|
  They are under the normal tubes category... too bad, I might have saved a bit of money with the combined shipping.
  I saw a pair of tested 6n6p nos from orpheus_2005 (whose store is very similar, almost identical to lci_electronics) which are very close matched... I might try them.
   
  Do you think that the gold grid makes any difference?
   
  EDIT: by the way... take a look at orpheus' 6n6p... it seems that they have the gold grid as well:


----------



## Gatepc

Very cool, I've been waiting for something like this very well put together! Thank you for taking and money to write this review for us.


----------



## john57

Many Russian 6n6p  tubes use copper posts for the grid wires which may look like gold wires but are steel alloy. The [size=x-small]Sovtek 6H30  [/size]tube that I was testing also uses steel alloy grid wires. See post #36


----------



## donluca

oh, now you really made me wanting to try out both! Poor my wallet


----------



## donluca

Alright, I've bought a pair of matched 6n6p without gold grid.
   
  Maybe in the future I'll consider upgrading them.
   
  Meanwhile my amp still hasn't been shipped yet, lol.
   
  EDIT: It turned out that the ones I've bought are with the gold grid! The seller informed me right now.
   
  He still has some left, if I were you, for 10$ for a matched pair, I'd snatch them right now 
   
MATCHED PAIR 6N6P Military GOLD GRID TUBES ECC99 E182CC


----------



## DanPluck

Great guide you got going here. 
   
  Im pleased to see someone else raving about the Voshkod 6ZH1P-EV.  I have tried a large range of tubes with my LittleDot 1+ and keep comming back to them.


----------



## john57

[size=medium]This is a good catch and did the seller miss at first the fact that the tubes had gold grids on them? I looked again at my standard 6N6P tubes under the stereo scope and saw that the wires are steel (nickel colored) wrapped around posts that appeared to be cooper which in turn mask some of the color of the steel wires.  I enjoy my gold grid 6N6P tubes the peaks like the bass drum has more impact and the highs are smooth and dynamic as well.  [/size]


  
  Quote: 





donluca said:


> Alright, I've bought a pair of matched 6n6p without gold grid.
> 
> Maybe in the future I'll consider upgrading them.
> 
> ...


----------



## donluca

Quote:


john57 said:


> [size=medium]This is a good catch and did the seller miss at first the fact that the tubes had gold grids on them? I looked again at my standard 6N6P tubes under the stereo scope and saw that the wires are steel (nickel colored) wrapped around posts that appeared to be cooper which in turn mask some of the color of the steel wires.  I enjoy my gold grid 6N6P tubes the peaks like the bass drum has more impact and the highs are smooth and dynamic as well.  [/size]


 


  yeah, I first asked him if they were the gold grid ones and he said that they weren't, I bought them anyway.

 After a bit he messaged me telling me that he broke one by accident (I don't trust him on this, imho he broke one himself to check it out of curiosity) and that they had the gold grid indeed. Then he changed the name and description of the auction and included the photos of the broken tube where you can clearly see the gold grid.
  I immediately ordered another pair and made the combined shipment as it looked like a real bargain to me.
   
  I hope that I've not been fooled.


----------



## 188479

Hi All:
   
  I have had my mark III for a few weeks and have played with switching driver tubes.  Thanks for the great suggestions!  I just ordered these power tubes off Ebay:
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=130560513461&ssPageName=STRK:MEWNX:IT#ht_6908wt_1037
  How do they compare to the very available 6H30Pi from Electro Harmonix?  Anything else I should look at for power tubes?


----------



## AlexRoma

Good question on Electro Harmonix. I've been waiting for a long time the PowerTube section update. Dept_of_Alchemy, show must go on 
	

	
	
		
		

		
			





 !


----------



## Max F

Great guide!  Thanks for you hard work on this.
   
  I've had my MKIII for a few years with several tubes and have some observations that I can add.
   
  There's a greater difference in sound moving from tube family (EF95, EF92, EF91) than moving from brands within a family (with the possible exception of the EF95 tubes).
   
  The biggest change in sound moving from tube families is the soundstage:  EF95 - in your face, EF92 a little more spread out, EF91 wow you're getting out there, maybe too far.
   
  The EF95 tubes have the greatest diversity in sound between brands and types.
   
  The EF91 and EF92 tubes sound very similar to one another in the same family most likely due to the fact that they were manufactured in the same plants in England.
   
  You can get really good deals on relabled EF92 tubes sold in the US (still UK tubes).
   
  My favorite all around tube is the Raytheon black 6AK5W from the 1950s (for my HD650 headphones).


----------



## john57

[size=medium]Max F[/size]
  [size=medium]I agree mostly what you said. While most of the EG91 and EF92 tubes are built in England my EF91 GEC (General Electric) also made in England has a unique built make up that is different from others.  It is heavily guttered with black tops with silvered middle that is addition to the wide metal band that is common to the EF91 and EF92 family of tubes. The EF91 GEC also has a square wire anode ring on top and boxy structures underneath the anode ring that I do not recall in other tubes. The EF91 GEC and the United Electron EF92 tube do not sound the same but they both have big soundstage. Recording made in a cathedral like environment are fantastic. I also find great clarity for dialog in movies and even with Netflix and Hulu. The GEC tubes seems to be more picky on what power tube it is paired with. There is more to learn since I only own my MKII for two and half months and I am waiting on parts for my next experiment.     [/size]


----------



## Max F

Good point John.  I'd have to admit my sample sizes for the EF91 and EF92 tubes are rather small.
   
  Something else i forgot to mention, the guide mentions that some people reported distortion on some EF91 tubes.  If I remember correctly, the consensus was that the distortion occured on low impedance headphones only - ones that required more current to drive.


----------



## eclipes

Hey guys
   
  Have an extra pair match Mullard M8083 Large Shield, just pm me. Bought it based on review from the tube rolling thread and John's recommendation.


----------



## john57

Max F
   
I would think the point is that the power tubes is what really drive the headphones and the driver tubes like the EF91 just drive the power tubes grids. I am at the same opinion that with the OP (Dept_of_Alchemy) that distortion is more of an issue with the power tubes not the driver tubes until I learn otherwise. The OP stated that he never experienced the issue of distortion with the EF91 tubes using the 6H6P-I power tubes himself. The EF91 strong and clear midrange and treble just makes everything more obvious and it is my guess that is the reason that some users will notice distortion somewhere in the chain.


----------



## donluca

I got my mk2 yesterday, I'm burning it with the standard valves that came with the amp.
   
  Using an AKG K601 with gain set to 5.
   
  As soon as I have 100 hours I'll switch the power tubes and driver tubes.
   
  I have ready my 6H6P with gold grid and voshdok 6zh1p-eb from the '73. They should be my main setup, after I'll try playing with different driver tubes.


----------



## Impulsive

another happy owner of Voshkods.
  They are just awesome.
  Perfect highs, lovely midrange and punchy, exact, plastic bass.
  The best tubes that i ever heard on MK III


----------



## eclipes

How do you guys find the Voshkods against Mullard M8083? I really don't know if I should get it, what I expect from voshkods compared to the Mullard? Currently using opamp2107 with the M8083 so dont know if the voshkods will be a great match with it. Let me know guys


----------



## Oskari

You can call it Восход or Voshod or Voskhod but don't call it Voshkod anymore. Please.


----------



## Impulsive

Quote: 





oskari said:


> You can call it Восход or Voshod or Voskhod but don't call it Voshkod anymore. Please.


 


  It is not my fault, check here.
http://www.ebay.com/itm/2x-Voshkod-6ZH1P-EV-Matched-Pair-6AK5-EF95-403B-5654-/290581308804?pt=Vintage_Electronics_R2&hash=item43a7fee584


----------



## eclipes

yeah haha, its all yen audio's fault...


----------



## Frank I

Quote: 





eclipes said:


> yeah haha, its all yen audio's fault...


 


  Yen wen bad on ebay once under another user name. I bough tubes from him before he went bad but he took alot people money and never sent them tubes


----------



## TMRaven

I bought those same 6N6P tubes from orpheus, I don't really notice a difference compared to the stock tubes, except they're a little less powerful.  Nice to have as backup.


----------



## Impulsive

Quote: 





frank i said:


> Yen wen bad on ebay once under another user name. I bough tubes from him before he went bad but he took alot people money and never sent them tubes


 

 all good, tubes arrived packaged safe and fast.
  weird.


----------



## donluca

Quote: 





tmraven said:


> I bought those same 6N6P tubes from orpheus, I don't really notice a difference compared to the stock tubes, except they're a little less powerful.  Nice to have as backup.


 


  How much burn in time do they have?
   
  I'm still on stock tubes and I noticed that after 30h of burn in the amp plays louder.
  As soon as I have 50h of burn in I'll switch to the 6N6P from orpheus (which I can clearly see that they have the gold grid) and the voskhod ('73) tubes.


----------



## Frank I

Quote: 





impulsive said:


> all good, tubes arrived packaged safe and fast.
> weird.


 

 that does not make up for all the money Yen took last year and did not deliver. There are threads in the forum about it if you do a search


----------



## Impulsive

Quote: 





frank i said:


> that does not make up for all the money Yen took last year and did not deliver. There are threads in the forum about it if you do a search


 


  well, i heard about that, but for some reason they are here again and appears very reliable.


----------



## Frank I

Quote: 





impulsive said:


> well, i heard about that, but for some reason they are here again and appears very reliable.


 


  until he does it again. Once was enough for me to stay away Too many reliable vendors who will not rob you out there IMO


----------



## mordy

Just curious - Ebay is very strict and does not take kindly to people who are dishonest. Did Yen Audio operate under a different name before?


----------



## Frank I

Quote: 





mordy said:


> Just curious - Ebay is very strict and does not take kindly to people who are dishonest. Did Yen Audio operate under a different name before?


 


  Yen1233 was his user ID. So if you search ebay you will see what he did to people. if thats not enough to warn people here/ good luck just remember Leopards do not change their spots


----------



## TMRaven

Quote: 





donluca said:


> How much burn in time do they have?
> 
> I'm still on stock tubes and I noticed that after 30h of burn in the amp plays louder.
> As soon as I have 50h of burn in I'll switch to the 6N6P from orpheus (which I can clearly see that they have the gold grid) and the voskhod ('73) tubes.


 

  
  I havn't experienced any changes from burn in with them.


----------



## Impulsive

i just purchased lot of 4 NOS 6N6P Gold Grid for just 10 USD
  Good catch, what do you think?
http://www.ebay.com/itm/160642553035?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649
  If they wont sound any better, backup is always welcome.


----------



## donluca

sounds like a great bargain to me!


----------



## mordy

Hi Impulsive,
   
  I found this guy two weeks ago and asked him to set up the two pair deal that you see on Ebay. However, I have not yet received the tubes I ordered (sent on 8/19) and I did not want to report on the tubes until I had seen them and listened to them.
  This guy seems to be a good and co-operative seller, but he is just starting out with almost no feedback.
  It certainly is a very good deal, though.
  There should be enough tubes for everybody - he has 380 of the 6N6P gold grid tubes.


----------



## john57

Since the tubes comes from the  Russian Federation  it can take up to a month to get the tubes.


----------



## mordy

The present 1975 Voshwhatever (I am afraid to use the wrong spelling) 6N6P that I use came from Vladivostok (6500 miles away) in two weeks.
  I do recognize that it could take much longer - you never know. Will let you know when they arrive and first listening impressions.


----------



## adamrut

[size=10.0pt]Any difference between the 6N6P Gold Logo, "OTK" and the Rhombus 5 Logo from these 2 sellers?  They are both gold grid…[/size]
   
   
http://www.ebay.com/itm/MATCHED-PAIR-6N6P-Military-GOLD-GRID-TUBES-ECC99-E182CC-/250874846148?pt=Vintage_Electronics_R2&hash=item3a694e5bc4
   
http://www.ebay.com/itm/2-matched-6N6P-ECC99-E182CC-6N6-Gold-Grid-1978-Rare-/130560513461?pt=Vintage_Electronics_R2&hash=item1e660355b5


----------



## mordy

Hi Adamrut,
  Check out this link instead. If you e-mail him, he will make an auction on Ebay for two tubes for $7 + $8 shipping.
   
  http://www.ebay.com/itm/160642553035?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649
   
  As far as I know, OTK is just a Russian symbol for passing quality control.


----------



## john57

The top are 1983 tubes and the bottom are 1978 tubes.


----------



## john57

"*OTK*" means that the item was manufactured to military specifications . It is similar to American MIL-STD  standards


----------



## adamrut

Quote: 





mordy said:


> Hi Adamrut,
> Check out this link instead. If you e-mail him, he will make an auction on Ebay for two tubes for $7 + $8 shipping.
> 
> http://www.ebay.com/itm/160642553035?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649
> ...


 


  Thanks mordy! I will give a shout.

  
  Quote: 





john57 said:


> "*OTK*" means that the item was manufactured to military specifications . It is similar to American MIL-STD  standards


 

 Thanks john57 I new at tubes and trying to get my feet wet.


----------



## Impulsive

AFAIK about Rhombus Logo, this is what one of the sellers says about that tubes:
*6N6P / 6Н6П Soviet TUBES*
*!! MILITARY "Rhombus 5 Logo" VERSION !!*
   
  So it should be designed and made for Military purposes.
  I think OTK means that tubes passed some quality control test.
   
  BTW mordy are you now refering to which seller? el-rayder or orpheus ?
  Well, I do personally think that you just should wait a little longer, give it another week.
  You can always ask him what's going on or in the end open claim.
  I dont expect this 4-pack to arrive anytime soon, but the guys seems serious. I messaged him and he nicely replied back.


----------



## donluca

Today I've swapped the tubes for the 6N6P gold grid ones and the Voskhod ones and even without burn it the difference is night and day.
   
  Actually I feel that with the 6N6P it plays just a bit louder than with stock tubes.
   
  Strange that one of the 6N6P is more lit than the other... the channels are balanced.
  Oh well...


----------



## adamrut

Quote: 





impulsive said:


> AFAIK about Rhombus Logo, this is what one of the sellers says about that tubes:
> *6N6P / 6Н6П Soviet TUBES*
> *!! MILITARY "Rhombus 5 Logo" VERSION !!*
> 
> ...


 


  I messaged el-rayder and he is going to put some more up, so I will have to wait and see.


  Quote: 





donluca said:


> Today I've swapped the tubes for the 6N6P gold grid ones and the Voskhod ones and even without burn it the difference is night and day.
> 
> Actually I feel that with the 6N6P it plays just a bit louder than with stock tubes.
> 
> ...


 

 Good to hear, my Voskhod tubes are on their way!


----------



## donluca

Quote: 





adamrut said:


> Good to hear, my Voskhod tubes are on their way!


 

  
  Where did you buy them? There are a hell lot of different versions, I've bought something like 3 different pairs.
   
  The actual ones are 1975 Voskhod 6sh1p-ev.
   
  I'm waiting for others to come:
   
  2 matched Voskhod 6J1P-EV with gold grid from the 80's
  2 unmatched Voskhod 6J1P-EV with gold grid from the 70's
   
  I'm wondering if they'll sound different from the ones I have. Otherwise they'll do a nice backup.
   
  I'm currently scouting the bay for some ef91 and ef92 tubes for cheap.


----------



## adamrut

Quote: 





donluca said:


> Where did you buy them? There are a hell lot of different versions, I've bought something like 3 different pairs.


 

 I bought them from Yen Audio, he states they are from the 1970's.  Which ver do you like the most?
   
http://www.ebay.com/itm/2x-Voshkod-6ZH1P-EV-Matched-Pair-Little-Dot-Amp-III-IV-/290581023549?pt=Vintage_Electronics_R2&hash=item43a7fa8b3d#ht_1386wt_1344


----------



## mordy

Hi Imp,
   
  Only referring to El-Rayder.


----------



## mordy

Hi DonLuca,
   
  Please let us know if there is a difference with the gold 6J1p-EV compared to the non-gold variants once they arrive.
  Regarding the regular 6J1P-EV tubes I remember reading a post on this forum that stated that they all sound the same.
  Regarding the age of the tube a lot of people, and certainly Ebay sellers, seem to think that older is better, especially since they could get more money for older tubes.
  As far as I am concerned the proof is in how they sound. Therefore, a 1975 Sylvania tube may sound better than a 1950 Sylvania tube. However, there seems to be some type of consensus that Russian tubes made after 1990 are not as good as earlier ones, perhaps connected with the fall of communism and the chaos that followed in the manufacturing sector.
  It is also my impression that most, if not all Russian tubes, were made for the military in the 1970's to the 1990's.
  Regarding the OTK symbol, this is what I found:
   
  [size=medium]"The label OTK on the surface of the tube bulbe means that
 it is a Russian tube was gone under a military test.
 OTK is an abbreviation in Russian language.
 It means: it was controlled by a *Military* organization.[/size]"
   
  We have something similar on US made tubes made to military specifications: "JAN" which stands for "Joint Army and Navy". Sometimes US made tubes have a W after the designation, such as 6AK5W. The W stands for more rugged construction, although I do not know what this specification actually means.


----------



## DanPluck

Quote: 





donluca said:


> Where did you buy them? There are a hell lot of different versions, I've bought something like 3 different pairs.
> 
> The actual ones are 1975 Voskhod 6sh1p-ev.
> 
> ...


 


   


  Quote: 





adamrut said:


> I bought them from Yen Audio, he states they are from the 1970's.  Which ver do you like the most?
> 
> http://www.ebay.com/itm/2x-Voshkod-6ZH1P-EV-Matched-Pair-Little-Dot-Amp-III-IV-/290581023549?pt=Vintage_Electronics_R2&hash=item43a7fa8b3d#ht_1386wt_1344


 

 I have 10 1970s and 1980s 6ZH1P tubes on my LDMK1+ and Alessandro MS2i's and in all honesty i prefer the 80's tubes.  I cant put my finger on it as everyone raves about the 70's tubes but the 80's just sound better.
   
  Do yourselves a favour and jsut buy a batch of 10 from the international sellers for $15 and stop throwing money at Yenaudio for pairs.


----------



## mordy

Dear AR,
   
  Looking at the link below will make you into an expert on the different Russian tube factories. It looks to me that the "Rombus" referred to in the ad is the old symbol of the famous Reflektor factory.
   
   
   
  http://www.ominous-valve.com/russtube.html


----------



## donluca

Quote: 





danpluck said:


> Do yourselves a favour and jsut buy a batch of 10 from the international sellers for $15 and stop throwing money at Yenaudio for pairs.


 

 /this
   
  I wouldn't pay more than 8 euro + shipment for a couple of tubes, matched or not. Everything more is just legalized robbery.
   
  Quote: 





mordy said:


> Hi DonLuca,
> 
> Please let us know if there is a difference with the gold 6J1p-EV compared to the non-gold variants once they arrive.
> Regarding the regular 6J1P-EV tubes I remember reading a post on this forum that stated that they all sound the same.
> ...


 

 As soon as they arrive I'll let you know... they are dispatched from Moscow so I suppose that they'll be in my hands in mid september or so.
   
  Meanwhile I think that I'll lower the gain since most tracks are incredibly loud even at 9 o'clock.
   
  Last but not least, I'd like to say that what's important is what your ears like, not the date of production of the valve. Psychoacoustics apart, just try different valves and see what you like most, without thinking of their types, reviews etc.
   
  I've put my eyes on some french ef91 tubes on the bay, I'll see if I can get them for a reasonable price
   
  http://cgi.ebay.it/2-lampes-tubes-6AM6S-EF91-CSF-doccasionstestees-/180715896571?pt=FR_JG_Collections_Radios&hash=item2a1381befb#ht_500wt_1048
  http://cgi.ebay.it/Lot-de-2-lampes-tubes-6AM6-EF91-doccasions-testees-/180715895676?pt=FR_JG_Collections_Radios&hash=item2a1381bb7c#ht_500wt_1048


----------



## eclipes

Hey John what do think about the Mullard M8083 vs *Voshkod 6ZH1P-EV*

 Currently using the Mullard M8083 and was wondering how it compares with the Voshkod, I am looking for the warmest set up possible.
   
  Let me know guys


----------



## donluca

As far as I've read around, for the warmest setup possible you should go for the mil spec ef91 mullards.


----------



## Impulsive

I can confirm that Mullards EF91 CV5377 that were ones from my first tubes, were very bright and now I can say I do not have more brighter tubes.
http://cgi.ebay.com/EF91-SPECIAL-CV5377-MULLARD-MATCHED-PAIR-NOS-/260735396781?pt=UK_Consumer_VintageAudio_RL&hash=item3cb50a6bad
  They didnt cost too much, plays nice but too bright for me.
  Still big difference from stock.
   
  Well, Gold grid on Voskhods, hmm I never heard about them.
  I am curious on sound too.
   
  Regarding US "W" letter after name (6AK5W vs. 6AK5 for example)
  As far as I know, W stands for prolonged life, better build quality and so..


----------



## mordy

Dear Imp,
   
  Here is the link to the gold Voskhod 6J1P tubes:
   
  http://www.ebay.com/itm/2-pc-6J1P-EV-EF95-6F32-6AK7-Gold-Platinum-grid-NIB-/130436695928?pt=Vintage_Electronics_R2&hash=item1e5ea20778
   
  Have not seen any reviews of them anywhere.


----------



## Impulsive

hey Mordy.
  3 USD per tube? Good god, that makes no sense.
  Pair of Voskhods* 6ZH1P-EV* cost me 24 USD plus shipping.
  How can Gold-Platinum plated tube cost only 3 USD?
   
  Well, I feel stupid...


----------



## donluca

http://cgi.ebay.it/NEW-NOS-6Sh1P-EV-EF-95-6AK5-Russian-Pentode-T-/140540483178?pt=Röhren&hash=item20b8dd966a#ht_6823wt_1026
   
  These are the ones I'm using now. They cost 1,50 euro each.
   
  They are the closest to what the OP used.
  You should really stop throwing your money out at Yen or other tubes seller alike. Tubes are cheap things, there's no need to spend such money.


----------



## mordy

Dear Imp,
   
  We are all learning, and it is quite possible to get good deals with a little patience. However, you must take into account the shipping in the total price. So, shipping included, I would not pay more than $8/tube maximum, and preferably $8 for two tubes.


----------



## Impulsive

hmm.
  I bought only Voskhods from yen, the rest was cheaper, except of EF 91 Mullards.
  But never mind.
  I do not plan any more driver tubes. I am really happy with Voskhods.
  Just check out that Gold grid 6N6P and that's all.
  If I wont find something special again :-D


----------



## donluca

Does anyone know what's the difference between 6AM6 and 6AM6S in the EF91 family?
   
  Is the latter one mil spec?


----------



## mordy

Hi All,
   
  As far as I am concerned the most difficult quality to find in the driver tubes for the Little Dot MkIII is a hefty, strong, full, detailed, tuneful and convincing bass.
  Well, folks, here is the King of Bass in the EF95 family: Amperex 5654 PQ (Premium Quality) Made in Holland in the 50's. The bass is the best of any tubes I tried (Voskhod, Mullard, RCA, Tung Sol, Sylvania, GE etc etc).
  The presentation is in your face, like you are sitting in the first row, in front of the rhythm section. The highs are excellent, but the mid range is a slightly rough and not as sweet as the Mullards. But the bass... And that means a lot to me. (Somebody on this forum commented that these tubes are too bass heavy. My ATH-AD700 cans are bass shy, so for me it works very well, including my speakers.)
   
  How to celebrate the King of Bass? Listen to this drummer who when playing this solo was older than any tube you are likely to own (77 years). Go to 1 min 30 sec and crank it up as much as your ears can take! If you don't like New Orleans style drumming there is always that little X in the upper right corner of the screen.....
   
  http://www.youtube.com/watch?v=a3foG9N0jpg
   
  PS: These tubes are hard to find. Don't know if the British made version is as good. And don't pay astronomic prices for these tubes...


----------



## donluca

Alright, I've won the auction for both the pairs of french tubes. (10 euros total)
   
  One pair is marked as "Dario 6AM6", the other is marked as "CSF 6AM6S" with code 6064... maybe they are dated 1960/1964?
  Anyway, cannot wait to lay my hands on them and see how they sound!
   
  I'm really getting into this tube rolling thing 
   
  P.S.: I've put my eyes on those too: http://cgi.ebay.it/2-PIECES-OF-EF91-CV4014-6064-QTL-NOS-NEW-OWN-BOX-MIL-/370533573330?pt=LH_DefaultDomain_77&hash=item564585a2d2#ht_500wt_814
   
  From what I've found around it seems that these are Mullards CV4014 which were rebranded by QTL, a Philips division... sounds interesting, I've got to check on my wallet and decide to pull the plug or not.


----------



## Impulsive

Quote: 





mordy said:


> The bass is the best of any tubes I tried (Voskhod, Mullard, RCA, Tung Sol, Sylvania, GE etc etc).


 

 Must...resist....


----------



## donluca

Be yourself.
  Be impulsive.


----------



## mordy

Hi Imp,
   
  Be patient and look for good deals. I paid $20 including shipping for 11 tubes - 2 Amperex PQ, 1 Sylvania Gold, 4 Tung Sol and assorted GE and others. The deals are out there, but you have to be persistent and patient.
  If there is any interest, I am willing to give some hints and tips on how to shop Ebay for bargains - it may stop me from buying too many tubes!


----------



## dadong

hey guys i just got the 6zh1p-ev from yen audio. and i have to say these completely destoried the stock jan5654's that came with my MKIV. i'm just wondering if this:
http://www.ebay.com/itm/2-pc-6J1P-EV-EF95-6F32-6AK7-Gold-Platinum-grid-NIB-/130436695928?pt=Vintage_Electronics_R2&hash=item1e5ea20778#ht_5212wt_1163
   
  is legit? cause if it is i'm buying more for backup. 
   
  am also in search of some power tubes. the 6n6p gold grid looks quite promising. is it any good?
http://www.ebay.com/itm/2-matched-6N6P-ECC99-E182CC-6N6-Gold-Grid-1978-Rare-/130560513461?pt=Vintage_Electronics_R2&hash=item1e660355b5#ht_6908wt_1163


----------



## Impulsive

I do not know what's the difference, if even there is some, between usual and golden-platinum grid.
  Voskhods itself are awesome tubes.
  Regarding 6N6P golden grid, I have 4 pieces on the way so I cant tell yet. But definitely perfect as backup.
  But DONT buy that pair, 2 pieces for 29 USD? what the hell?
  I paid 10 USD for 4 pieces.
  There is that seller, el-rayder who has these tubes and he will make up auction for you if you PM him and i believe, for really better price than 29 USD.
  If you have MK IV, then you should be able to use another tube family, 6H30 if I am right.
  And 6H30 tubes are awesome.
  Pitty I cant use them.
   
  Mordy, you bought very nice lot, these lots are the best for trying out different tubes cheaply.
  No wonder you found this secret little gem.
   
  I wont buy any tube any time soon, because now I really run out of money..so just stalking what's out there and noting it all.


----------



## mordy

Dear Imp,
  If you have the latest version of LD MkIII there is no problem in using the 6H30 power tubes. However, I cannot remember reading that it was any great improvement over the standard power tubes.


----------



## Impulsive

Hey mordy.
  THat was the first thing I checked when I got my amp from fellow headfi-er.
  Circuit board is rev. 1.0, what requires resistor mod to use 6H30.
  But if I could use 6H30, I would definitely try this beast.
http://www.ebay.com/itm/ws/eBayISAPI.dll?ViewItem&item=150656561339


----------



## dadong

Cool Thanks for that Impulsive.
   
  So from the sounds of it the 6h30 is defiantly a better choice. I'm looking around trying to score some 6h30pi gold's. Still i'm curious how it fares against the stock sovtech 6h30n-eb's
   
  btw this a good deal?
   
http://www.ebay.com/itm/4x-MATCHED-TUBES-6J1P-EV-6J1P-EF95-6F32-6AK5-NOS-80s-/250855334278?pt=Vintage_Electronics_R2&hash=item3a6824a186#ht_2493wt_1163


----------



## Impulsive

this is what I found.
  Pretty new seller, I would give it a try.
  Definitely the cheapest 6H30Pi from EH
http://www.ebay.com/itm/6H30pi-EH-/270811204607?pt=Vintage_Electronics_R2&hash=item3f0d9b0bff
  or these ones.
  A bit more expensive, but still far cheaper than 74 USD usual pair
http://www.ebay.com/itm/NEW-SOVTEK-6H30PI-Supertube-ARC-Conrad-Johnson-BAT-2PCS-/120748685916?pt=Vintage_Electronics_R2&hash=item1c1d2eba5c


----------



## donluca

Quote: 





> Originally Posted by *dadong* /img/forum/go_quote.gif
> 
> btw this a good deal?
> 
> http://www.ebay.com/itm/4x-MATCHED-TUBES-6J1P-EV-6J1P-EF95-6F32-6AK5-NOS-80s-/250855334278?pt=Vintage_Electronics_R2&hash=item3a6824a186#ht_2493wt_1163


 


   
  from the picture it seems that they were made in the '81. Correct me if I'm wrong but those were manufactured post-war. As far as I know those made after the 80s were worse than the one made before (during cold war).
   
  But again, I can't say for sure, I've bought 3 different types of 6J1P-EV so I can compare them.
  Anyway you might give it a go since they are 10 dollars for 4 valves (matched).
   
  As of now it seems that my 6ZH1P-EV from the '75 give an extra-detailed sound, a lot transistor-like.
  Which is not bad by itself, but personally I was looking after a more warm, soft sound. Anyway they are still finishing burn-in period (I give 50 hours burn in to each pair of valve).
   
  Old and crappy recordings hiss and trebles are quite spiky, but on good recordings they sound amazing. 
  I'll report back in 2 days when they'll have settled.
   
  Oh, and 25$ per tube is way too much: I paid my little dot mk2 something like 120 dollars, I'm not willing spending another half of it for a pair of power tubes. IMHO obviously.


----------



## dadong

Quote: 





impulsive said:


> this is what I found.
> Pretty new seller, I would give it a try.
> Definitely the cheapest 6H30Pi from EH
> http://www.ebay.com/itm/6H30pi-EH-/270811204607?pt=Vintage_Electronics_R2&hash=item3f0d9b0bff
> ...


 
  Wait doesn't the MK IV come with the EH stock?? or are they different. 
   
  and i rather find a matched pair


----------



## Impulsive

I do not know what are stock tubes on MK IV.
  And we had discussion about paying more for matched pair vs. unmatched earlier, conclusion is that you should not worry or be scared from non-matched pairs, tubes should work flawlessly either because there is some quality testing being done and tolerance limits should allow to use any tube which passed quality control with any other QC passed tube and they should work the same, i.e. you should not hear any channel unbalance or something.


----------



## mordy

Here are the power tubes in the two versions of Little Dot MKIV:
   
   
  Power Tubes: 2x Soviet 6H30EH (MK IV) or 2x 6H30PI Gold-Pin (MK IV SE)
   
  The first two are the Sovtek 6H30 and the second are the Electro Harmonics 6H30Pi.  They sell for around $25 each and $36 respectively. Cannot speak about how they sound  because I have no experience with them.
   
  Dept of Alchemy: Would love to see your ratings of power tubes! When?


----------



## dadong

well i pulled the plug on the 4matched 6j1p-ev it's gonna be a while before they come. i can't wait to hear the difference between the yen audio 6zh1p-ev and the new pair. 
   
  I think i might also grab a pair of mullard 8100's to try as well as a ge jan5654w's just for the fun of it. man why is tuberolling such a fun thing
   
   
   
  and mordy if thats the case then is it safe to assume that the stock powertubes in the mkiv isn't all that bad and that an upgrade won't really affect my performance that badly.


----------



## mordy

Hi dadong,
   
  Cannot speak from personal experience about the Sovtek and EH 6H30 tubes but remember reading somewhere that the EH are better sounding, although this may depend on your equipment. (In addition, none of these meet my $8 rule as maximum per tube.)
  Just remember that the power tubes only account for about 15% of the sound, and that the different driver tubes make a much larger difference in sound.


----------



## Impulsive

yeah, mordy is right.
  Different power tubes make very little difference, because they just amplify, what driver tubes give them.
  But still, I am tempted by 6H30 I cant help myself 
	

	
	
		
		

		
			




   
  IMO good buy on that 4 6J1P-EV, 10 USD is good price.
  BTW Good choise on Mullards M8100, I really loved them, until I found out about Voskhods.
  I bought my Mullards here, price is OK for me and good seller too.
http://cgi.ebay.com/2x-NOS-MULLARD-CV4010-VALVE-EF95-M8100-6AK5-5654-Tubes-/290546585784?pt=Vintage_Electronics_R2&hash=item43a5ed10b8
  Mullards are real difference from stock.
  These M8100 are my second favourite tubes. Third goes EF91 CV5377 with very bright sounding(still not bad and very detailed, just shrilling was hurting my ears while listening to few s-s-s-s-s-s-s-sibilant songs).
  Just FYI, mullards bring out soundstage, details, clarity and more bass than stock tubes.
  EF91 VS Mullards: more brighter sounding, about equally detailed but not as much bass (I am freakin basshead so in terms of neutral sounding they DO sound neutral, I just love bass.)
  Voskhods are as good as M8100, The main difference I noticed immediately was amazing bass. My heart started to beat like crazy when I was in my bassy audio nirvana.
  The rest is pretty much same as on M8100, or I cant hear such small differences. Currently I am very happy with these Voskhods, they finally made my headphones sound in the way I wanted, I wont change a simple little thing now.
  But even M8100 vs stock tubes bring more bass, it was not just enough for me,
  Bass differences in chain: stock < M8100 < Voskhods are small, but when you jump from stock to Voskhods, that might be really big change. Juicy music brought me back to life.
  But dont think that bass overkills everything, on my DT 880 It is just more powerfull and plastic, very punchy but quality remains intact and bass is very exact. It does not kill any of details, trebles or mids.
   
   
  -Imp


----------



## donluca

great review there imp.
   
  It's strange that you've found the EF91 harsh, they should sound more mellow then an EF95.
   
  I'm still undecided on http://cgi.ebay.it/2-PIECES-OF-EF91-CV4014-6064-QTL-NOS-NEW-OWN-BOX-MIL-/370533573330?pt=LH_DefaultDomain_77&hash=item564585a2d2#ht_500wt_814 .
   
  7 € for shipping seems way too high to me, I might contact the seller and see if we can find a solution.
   
  P.S.: out of curiosity: how do you guys store your unused tubes? Did you just leave them in their boxes (if they have one!) or did you buy/make something apposite for them?


----------



## Impulsive

Thanks donluca,
   
  If any questions, just ask, I will try to do my best to provide you answer if I can.
  Yeah, EF91 sound very bright with ear piercing treble, but just on ear-piercingly-recorded songs.
  On the rest of my tubes the songs sound just fine.
  Well, I think of only cause why you experienced different, I think you havent had the same tubes as I have.
  We both have probably EF91 family, but different type and manufacturer.
  These are EF91 that I have.
http://cgi.ebay.com/EF91-SPECIAL-CV5377-MULLARD-MATCHED-PAIR-NOS-/260735396781?pt=UK_Consumer_VintageAudio_RL&hash=item3cb50a6bad
  Yeah, more expensive than yours. Maybe just because its simply Mullard.
   
  Regarding storing, I just pack tubes back to cigar wrapping, close them onto their small boxes and store inside my PC table in a drawer.


----------



## dadong

Thanks for that imp... definantly will give the mullards a try. XD and i'm also interested in the Tung-sol 6AK5's but they are freaken expensive. 
   
  XD the voshkod really made me doubt myself. at first i really hated the highs on my hd650 seemed overly bright when i bought it (upgraded form hd555 with foam mod and soundstage mod) now with these tubes i live for the highs. SO... nice.


----------



## britt2001b

After promising myself that I wouldn't buy any new tubes for my Little Dot MkIII for a while, I have broken my promise. The recent discussion about the Voskhod 6ZH1P-EV's was too much to resist. So, after about 30 hours of burn in, here are my impressions:
   
  Fantastically clear bass with an impressive sound stage. Also, a nice open, airiness sound that allows room acoustics to be heard well. I'm very satisfied with the Voskhods. 
   
  I've read the Voskhods require excessive burn in time. I'm curious if they will really continue to improve.


----------



## donluca

Quote: 





impulsive said:


> Thanks donluca,
> 
> If any questions, just ask, I will try to do my best to provide you answer if I can.
> Yeah, EF91 sound very bright with ear piercing treble, but just on ear-piercingly-recorded songs.
> ...


 


  Actually I don't own yet any EF91, I was speaking by reviews I've read around in this topic. 
   
  Sadly I only have the Voskhods from the '75, the others are still coming 
   
  About valve storing... I was thinking of making some custom sockets where I can also show them. I'm very fond of my valves and I like to show them. I'm not sure about the more appropriate material for making the "stand". I've bought a nice long piece of wood but I'm afraid that the wood might catch humidity and rust the connectors. Maybe polystyrene is more appropriate?


  Quote: 





britt2001b said:


> I've read the Voskhods require excessive burn in time. I'm curious if they will really continue to improve.


 

 Really? Where did you read that? If so, then I might give my Voskhod even more burn in time than the standard 50 hours. To me they sound a tad too bright for a valve.


----------



## britt2001b

_"Really? Where did you read that? If so, then I might give my Voskhod even more burn in time than the standard 50 hours. To me they sound a tad too bright for a valve."_
   
   
  Hello Donluca,
   
  I picked this up from the gigantic "Little Dot Mk III Tube Rolling" thread at post number 2522 quoted below. *Mordy* was replying to *AlexRoma*. It appears Mordy recognized some significant changes at 120 hours. You might want to give the Voskhods some more time. 
   
   
_"Hi AlexRoma,

 Thank you for pointing out that the Voshkod 6J1P-EV tubes need an extra long burn in perriod. I now have around 120 hours on my 1973 tubes and they sound very different compared to before. The bass, even though still very powerful, is much smoother, and the irritating sharp highs are gone.

  The entire presentation is more soft, and now the the highs even tend to be a little dark through my Audio Technica ATH-AD700 headphones."_


----------



## mordy

Hi Imp & DonLuca,
   
  I found a simple and cheap storage solution for my driver tubes: A see through plastic box with movable dividers made for storing screws, nuts and bolts. For $6 I bought a box with 48 compartments that each can store three tubes standing up. I use styrofoam "peanuts" from packaging to fill out empty spaces so that the tubes don't rattle around. If I selectively remove the dividers I can fit many more tubes into one compartment. (To find the right size box I brought a tube with me to the hardware store.)
  Then I stick on white address labels and write what is inside - Mullard EF95/CV850 Mitcham 5/63 as an example. In this way I have some 100 tubes easily accessible (don't worry, I have more tubes). You could put the tubes in alphabetical order or whatever to make them easy to find.
  The only drawback is that it is a little hard to grasp the tubes to get them out. I usually grab them by the tip or stick my pinkie in and slip them out one by one.
  My box is not deep enough for the power tubes. Here I remove a divider and lay them down.
   
  Gosh, I did not realize that I must have over 200 tubes by now! However, by buying lots and buying carefully, many tubes cost less than $1, and the most I paid was $7.50. The average price is probably around $3-4.
   
  Don't know why I find tube rolling so exciting, but when you find the perfect combination of tubes it is such a pleasure to listen to familiar recordings through the LD MKIII and hearing things I never heard before.


----------



## Impulsive

nicely said mordy!
  Would you mind taking photo of your storing system?
  I am very curious about it 
   
  Regarding Voskhods burn-in time, Well, I never had harsh highs.
  Highs were always lovely, fluid, non-shrilling.
  But that might be due to different headphones, maybe.


----------



## donluca

Quote: 





britt2001b said:


> Hello Donluca,
> 
> I picked this up from the gigantic "Little Dot Mk III Tube Rolling" thread at post number 2522 quoted below. *Mordy* was replying to *AlexRoma*. It appears Mordy recognized some significant changes at 120 hours. You might want to give the Voskhods some more time.


 


  Holy crap, 120 hours is an awful lot of burn in time. Anyway, thanks for the info! I'll keep on burning them in for the entire next week.


  Quote: 





mordy said:


> Hi Imp & DonLuca,
> 
> [...]


 


  Thanks, that's an awesome solution! Can you point me to an ebay seller that has these kind of things?


  Quote: 





> Originally Posted by *Impulsive* /img/forum/go_quote.gif
> 
> Regarding Voskhods burn-in time, Well, I never had harsh highs.
> Highs were always lovely, fluid, non-shrilling.
> But that might be due to different headphones, maybe.


 

 That's definitely headphone related, I have AKG K601 which have crystal clear highs, so I have to be careful about system matching.


----------



## mordy

Hi Donluca,
   
  Could not find this item on eBay - I now realize that it is a box made for fishing tackle. Here is a link to Amazon.com with a picture. It comes with 20 dividers. I used thin cardboard to make additional dividers.
  I don't know where you live, but I am sure that there are people who like fishing and need boxes to carry the various lures and hooks, so you should be able to find something.
   
   
  http://www.amazon.com/Flambeau-Flambeau%C2%AE-5004-Tuff-Tainer%C2%AE/dp/B0000AXMGN


----------



## HeatFan12

Quote: 





> Actually I don't own yet any EF91, I was speaking by reviews I've read around in this topic


 
   
  The EF91s are the hidden gem in these amps.  I don't see any elevated treble, just good all-around spectrum balance.
   
  My favorite:


----------



## britt2001b

Quote: 





donluca said:


> P.S.: out of curiosity: how do you guys store your unused tubes? Did you just leave them in their boxes (if they have one!) or did you buy/make something apposite for them?


 


  I took an old wooden chess set where the pieces are stored in a drawer below the board. The tubes fit in the places for the larger pieces but are too large for the pawn storage. The fits aren't perfect but it looks nice.


----------



## mordy

Hi Brit 2001b,
   
  A very aesthetical solution! Did you try some spikes or cones under the turntable?


----------



## britt2001b

Quote: 





mordy said:


> Hi Brit 2001b,
> 
> A very aesthetical solution! Did you try some spikes or cones under the turntable?


 

  Not yet. I don't use the turntable often. It was the only component I had matching in size that would cover the chess squares. I'm thinking about removing the turntable and replacing it with felt (to hide the squares) and placing the MK III on top. Visually, I think this would make a nice pedestal for it if the squares don't show.


----------



## donluca

Quote: 





britt2001b said:


> I took an old wooden chess set where the pieces are stored in a drawer below the board. The tubes fit in the places for the larger pieces but are too large for the pawn storage. The fits aren't perfect but it looks nice.


 


  That's awesome! Great idea.
   
  In the meantime the other Voskhods have arrived but the seller sent me 6 6J1P-EV from the '87... they should have been 4 from the 70s and 2 matched from the 80s. I contacted him and he said that he would send the Voskhods from the 70s for free, so now I have a lot of '87... as soon as I've finished burning in the other Voskhods I'll try these.


----------



## britt2001b

Thanks donluca.
   
  My Voskhods are at the 60 hour mark now and I'm still quite pleased. The bass is still very impressive, clean and powerful. I can't see how they could perform better but I'm sure enjoying the discovery process. The seller said they were manufactured in the 70's. I hope the 80's versions do as well for you. If not, you can look forward to the 70's. 
   
  As I'm writing this post, I'm listening to Wilco's "Sky Blue Sky" album which my son recommended. I don't think I have heard anything as nice as this through my headphones. Good sound, good songs, just a pleasure to the ears. I'm sure the Voskhods are contributing.


----------



## dadong

okay so my 80's voskhods is still gonna be a while before they arrive. now i want to also order some mullards ef92's any people who have this and can give recommendations on which kinds to get.
   
  also from what i can tell they average about 10-15 a tube. anyone know some good deals?


----------



## Cloud9Blue

Quote: 





dadong said:


> okay so my 80's voskhods is still gonna be a while before they arrive. now i want to also order some mullards ef92's any people who have this and can give recommendations on which kinds to get.
> 
> also from what i can tell they average about 10-15 a tube. anyone know some good deals?


 


  This is where I got myself a pair.  Fast shipping too; mine got to IL in less than a week.  
   
  http://www.ebay.com/itm/260735396718?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649#ht_500wt_1363
   
  However, I still think the Voskhods I got from Yen's Audio are superior.  The Mullards, in comparison to the Soviet tubes, produce harsh treble and rather loss bass, at least in my setup.
   
  Btw, I ordered 4 more Voskhods from this Italian supplier on ebay, as backup for my current ones.  Think these I am going to use these Voskhods until I upgrade my MkIII to something else (maybe the Phonitor).  But that won't be for awhile. 
   
  http://www.ebay.com/itm/130572501861?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649#ht_6823wt_1026


----------



## acetate

Great post. will try it soon


----------



## dadong

cloud9
   
  thanks for those links are those voshkods 80's or 70's?
   
  also you gave me a link to the mullards ef91's i'm looking for ef92's


----------



## Cloud9Blue

Quote: 





dadong said:


> cloud9
> 
> thanks for those links are those voshkods 80's or 70's?
> 
> also you gave me a link to the mullards ef91's i'm looking for ef92's


 


  70s, as written on the ebay post.  Should be the same as the ones I got Yen's Audio, but without inflated price.
   
  EF91 are pretty much the same on the Little Dot amps as EF92, both used the same jumper setting.  Well, these are the only EF91/92 tubes I have tried.


----------



## deadkenny64

Quote: 





cloud9blue said:


> This is where I got myself a pair.  Fast shipping too; mine got to IL in less than a week.
> 
> http://www.ebay.com/itm/260735396718?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649#ht_500wt_1363
> 
> ...


 
  Could you post once you receive these and try them out?  It looks like you are the only buyer so far (shows 4 sold) so it would be nice to have some confirmation before I buy a few more sets.


----------



## donluca

Quote: 





cloud9blue said:


> Btw, I ordered 4 more Voskhods from this Italian supplier on ebay, as backup for my current ones.  Think these I am going to use these Voskhods until I upgrade my MkIII to something else (maybe the Phonitor).  But that won't be for awhile.
> 
> http://www.ebay.com/itm/130572501861?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649#ht_6823wt_1026


 


  These are the Voskhods that I own, they have 50h on them and cannot commentate yet, I want to wait another 10-20 hour and then give a judgement. Apart from the initial harshness they have a wonderful sound, very detailed.


----------



## mordy

Hi DK64,
   
  The Voskhods in this posting and the seller are identical to what I bought about a year ago, but I believe that the seller is from Hungary.
   
  At first I liked the 1973 Voskhods, but as time wore on I liked them less because of harshness and some lack of definition in the bass and sharp highs. Then I read a post from AlexRoma that these tubes require extra long break in - 120 hours. (Regular tubes are said to last about 2000 hours. These EV/EB variants are rated for 5000 hours and maybe this is the reason that they require longer break in.)
  After 120 hours the tubes changed appreciably, becoming more mellow and better sounding with the sharp highs gone. However, in my set-up the Mullard M8100/CV4010, Amperex 5654 PQ, Tung Sol 6AK5 and Raytheon 5654/6AK5 small mica are better sounding.
   
  These Voskhods must be very strong tubes. The one I got from Budapest University came individually wrapped in a paper napkin inside a regular bubble wrap envelope and survived the trip fine!


----------



## AlexRoma

Voskhod 6J1P-EV tubes are simply FANTASTIC with all Senn's HD5** series..
   
  For BeyerDynamic, however, Mullard M8100/CV4010  perform better, softer and less fatigue on already emphasized "beyer" highs. Bass on my CV4010 is also, a little rolled off, but in a manner there is almost nothing to complain about. 
   
  I generally find russian tubes like V-shaped M8100 clone, with extra 3 db on both, bass and treble regions. But than again, with most Sennheiser phones, Voskhod sing great.


----------



## Cloud9Blue

Quote: 





alexroma said:


> Voskhod 6J1P-EV tubes are simply FANTASTIC with all Senn's HD5** series..
> 
> For BeyerDynamic, however, Mullard M8100/CV4010  perform better, softer and less fatigue on already emphasized "beyer" highs. Bass on my CV4010 is also, a little rolled off, but in a manner there is almost nothing to complain about.
> 
> I generally find russian tubes like V-shaped M8100 clone, with extra 3 db on both, bass and treble regions. But than again, with most Sennheiser phones, Voskhod sing great.


 

 Totally agree with this post.


----------



## Impulsive

Well, I have to disagree.
  As DT 880 user, Voskhods are totally superior to all tubes I currently have.
  I love the crystal clear detailed sound, lots of details, big soundstage, and the most important advantage over all my tubes, strong bass.
  Fck yeah.


----------



## Foresight

just ordered a pair of voskhods
  what power tubes do u guys recommend?


----------



## HeatFan12

What amp are you guys using these with?  LDIII, IV, I+?  I agree Voshs are great, but there is a great big ocean out there you have to experience.  EF95-  CBS Hytron 6AK5, Mullard CV850, GE 5-Star 5654W, GE 6096CT (excellent tube), SIemens 6AK5W, Tung-Sol 6AK5W, WE 403 A & B......EF91- Mullard or Brimar CV138........EF92- Mullard M8161 (CV4015)(large shield or small shield)...
   
  And if you have the I+, don't get me started on the 408As....Tung-Sol 6028s, Sylavania Gold...etc...
   
  Cheers


----------



## Foresight

Quote: 





heatfan12 said:


> What amp are you guys using these with?  LDIII, IV, I+?  I agree Voshs are great, but there is a great big ocean out there you have to experience.  EF95-  CBS Hytron 6AK5, Mullard CV850, GE 5-Star 5654W, GE 6096CT (excellent tube), SIemens 6AK5W, Tung-Sol 6AK5W, WE 403 A & B......EF91- Mullard or Brimar CV138........EF92- Mullard M8161 (CV4015)(large shield or small shield)...
> 
> And if you have the I+, don't get me started on the 408As....Tung-Sol 6028s, Sylavania Gold...etc...
> 
> Cheers


 
  little dot mk3


----------



## britt2001b

Quote: 





heatfan12 said:


> What amp are you guys using these with?  LDIII, IV, I+?  I agree Voshs are great, but there is a great big ocean out there you have to experience.  EF95-  CBS Hytron 6AK5, Mullard CV850, GE 5-Star 5654W, GE 6096CT (excellent tube), SIemens 6AK5W, Tung-Sol 6AK5W, WE 403 A & B......EF91- Mullard or Brimar CV138........EF92- Mullard M8161 (CV4015)(large shield or small shield)...


 

  Little Dot MK III here.


----------



## HeatFan12

I know ebay is the "goto" place for tubes and I have ordered many tubes from the bay.  But I have also branded out to many other sellers....
   
  Don't know if Jim ships outside the US, but he has great tubes at great prices.  Call him up and tell him you want a couple matched pairs....A man of few words, based in Orlando, FL, but great nevertheless....
   
http://www.vacuumtubesinc.com/Products/VacuumTubes/NewTubes1603to8950.aspx


----------



## dadong

Wondering what you guys use for DAC's around here.and any recommendations for someone wanting one for below 500 dollars?
   
  Something that will preferably make the hd650 faster and funner.


----------



## john57

I am using  [size=x-small]RDL HR DAC1  [/size]and a Behringer SRC2496 as a master  which is allot of fun. Not sure if it well make the headphone faster since that might mean different things.


----------



## Foresight

what power tubes do u guys recommend?
  using voskhods as drivers


----------



## donluca

Power tubes really don't change much in sound signature so don't worry about them, there's no need in wasting money on them. Yesterday I tried putting the chinese power tubes on and couldn't tell a difference between the new gold grid ones being a little bit louder.
   
  Little Dot MKII user here btw.


----------



## john57

I am also have the Little Dot MKII  and  using the gold grid 6N6P  tubes the sounds are more dynamic. It makes a difference with impact type of sounds like drums and musical peaks. Some say that power tubes are only 15% of the SQ but for me it is more like 25%


----------



## Impulsive

That's good to know, I ordered mine two weeks ago, should arrive some time now, I am looking forward


----------



## mordy

Hi John57,
   
  Finally got the 6N6P gold grid tubes from ElRayder - took three weeks. First impression is very favorable. The bass has much "more" of everything, exactly the way you describe it. These are the first power tubes I have used where the difference is approaching 25% (and not the 15% mentioned in various posts).
  However, this is a first impression, and I have to wait at least 100 hours of burn in to formulate a more definite opinion.
  The other thing to find out is which driver tubes work best in combination with these - any suggestions?
  Does anyone have experience with the Voskhod 6J1P-EV Gold tubes?
   
  http://www.ebay.com/itm/2-pc-6J1P-EV-EF95-6F32-6AK7-Gold-Platinum-grid-NIB-/130436695928?pt=Vintage_Electronics_R2&hash=item1e5ea20778


----------



## donluca

I have them, but only the ones from the 80s (1987).
  I still have to try them because I want to finish the burn in process of my voskhods from the '73


----------



## samman11

Has anyone compared JHY-6AK5 Hystron tubes with the ones mentioned above? I just started to listen to these in place of the default tubes that came with my LD Mk III. I like what I'm hearing in the mids and upper frequencies. Warm and clear, with nice bass. Of course, I have nothing to compare them to other than the stock LD tubes, so I thought I would ask others if they have heard them and what others think of them. Thanks.


----------



## HeatFan12

Quote: 





samman11 said:


> Has anyone compared JHY-6AK5 Hystron tubes with the ones mentioned above? I just started to listen to these in place of the default tubes that came with my LD Mk III. I like what I'm hearing in the mids and upper frequencies. Warm and clear, with nice bass. Of course, I have nothing to compare them to other than the stock LD tubes, so I thought I would ask others if they have heard them and what others think of them. Thanks.


 


 I love 'em...I use them with Grados...Gives them a smooth touch without losing extension.


----------



## rosgr63

Quote:


heatfan12 said:


> I know ebay is the "goto" place for tubes and I have ordered many tubes from the bay.  But I have also branded out to many other sellers....
> 
> Don't know if Jim ships outside the US, but he has great tubes at great prices.  Call him up and tell him you want a couple matched pairs....A man of few words, based in Orlando, FL, but great nevertheless....
> 
> http://www.vacuumtubesinc.com/Products/VacuumTubes/NewTubes1603to8950.aspx


 


   He does and his tubes are excellent.


----------



## Impulsive

Hey mordy!
  When did you ordered your tubes from el-rayder?
  I cant wait to get mine


----------



## mordy

Hi,
   
  Have just passed the 80 hour burn in mark on my new 1978 Novosibirsk 6N6P Gold Grid power tubes. Together with the Raytheon 50's small mica driver tubes the sound is absolutely enchanting and superbly beautiful and detailed - highly recommended. These power tubes add more in the lower and higher registers in a very pleasant way. (Thanks John57 for the Raytheon suggestion!)
  The cheapest place right now is ElRayder with $25 for four tubes including shipping. (Took me almost one month to get them.)
   
  http://www.ebay.com/itm/6N6P-ECC99-E182CC-Gold-Grid-1982year-NOS-Rare-Lot-4-/160652501737?pt=Vintage_Electronics_R2&hash=item2567a2a2e9


----------



## dadong

god waiting for tubes to arrive is too hard.
   
  I just won an auction for 6 mullards ef 91's for 8 dollars cad (with shipping) super excited to get them. will tell you guys what I think of them.
   
  Also just wondering what headphones are you guys using and with what gain setting?
   
  I played around with it last night and found a gain of 5 is pretty much perfect for the hd650's IMO.


----------



## britt2001b

Quote: 





dadong said:


> Also just wondering what headphones are you guys using and with what gain setting?
> 
> I played around with it last night and found a gain of 5 is pretty much perfect for the hd650's IMO.


 

 I also use gain setting 5 with my Sony MDR 7506 headphones. This setting provides an optimum  volume level at about 11:00.


----------



## Foresight

anyone else get static? its hard to notice @ low volumes but i can hear it when i turn the volume up w/ nothing playing


----------



## john57

The static could come from interference that the tubes are picking up or the tube pins may need cleaning to maintain good connection. The static could also being pick up on the inputs. Is the static coming from both channels?


----------



## Foresight

Yea from both channels, its only noticeable at really high volumes w/ no music. How do i clean the tube pins?


----------



## john57

Some will scrap with a knife or use *DeoxIT  * cleaner as an example. Tube equipment may not be as quiet as Solid State in some cases and if the volume control is set higher than the highest setting you would use with the headphone it is a moot point. Some tubes are a bit more quiet than others. Makes sure there is no wireless device very close to the tubes like you cell phone. In one cause I heard that the internal jumpers were not tight on the pins and someone replaced the jumpers with tighter ones. Does the static decrease or increase when you pull the RCA connections off from the Amp? Make sure that the volume is set low and Amp turn off before you do this.


----------



## dadong

I've found the MKIV to be very susceptible to electronic interference like john57 says. things like a un-properly grounded soundcard or bad shielding and even clumped up cables can cause static. Try moving the amp away from any electronic sources like monitors, computers, powercables, etc etc...
   
  you can also try cleaning out the mess in your computer. I used to get a hum in my amp but after taking apart my computer I noticed that there was an extra motherboard riser screw on my case I forgot to remove when I built it. After removing that, it started working perfectly.


----------



## Foresight

o.o i have a mk3 and its between my comp with wireless internet and my monitor. Internal Jumpers? @@. The only thing i know how to do is change the gain settings lol. This is my first tube amp so im a total noob.


----------



## Foresight

hmmm i think its because of my sound card asus dx 7.1 has no emi shielding


----------



## Alain3x

Hello, I have had a little dot mk3 for a few mounths now with the stock GE 5654. At my grandfather's I found a pair of 6CB6A. I looked up the specs which were almost the same as ef91's. So I switched the jumpers and tried them on. They work perfectly and sound better then the 5654s. If anyone is looking for more options then ef95, 92 and 91s check the 6CB6A's out. I Have ordered a few days ago a pair of m8161, mullard ef95 ,mullards ef91and the soviet rocket tubes so I will be able to compare more.


----------



## dadong

Alain that must have cost a pretty penny...
   
  i've got almost the same tubes coming my direction, but it's taking it's sweet time getting here. I also got a pair of superlux 668b so i'm extremely excited to see what that willl sound like with all the tubes.


----------



## donluca

Meanwhile I'm still waiting for my EF91 french tubes to arrive


----------



## Alain3x

Dadong, I hope your patience will be well rewarded. I checked out the superlux 668b, they look pretty cool. If they sound as good as they look they are a bargain. I use my mk3 to drive Akg K702's. Every headphones are different and I wonder which tubes mine will like compared to your's.
   
  Tubes forever,
  Alain.G


----------



## dadong

from what i read it's much better to find a a pair of k601's instead.. i hear they are still in production and way better than the plasticy k 7xx


----------



## donluca

ditto that.
   
  K601 owner here.


----------



## Impulsive

Ok so my 4 pack of 6N6P GOLD Grid arrived.
  first of all, when i was tracking the parcel, it took 2 weeks to travel from ULYANOVSK to MOSCOW, then two day from Moscow to My country :-D
  Now second thing, they DO work, all of them, so thats nice.
  But what makes me wonder, are grids.
  My stock 6N6P-I have more golden-like colored grids like 6N6P Gold Grid.
  But pure Gold should look more golder like probably-not-gold.
  I have only one explanation to this..mine 6N6P-I are gold grid too.
  Can somebody take pictures of grids of regular 6N6P and 6N6P-I?
  The best would be if somebody can take a photo of 6N6P Golden grid.
   
  I am including two photos of grids, check that.
  Regarding SQ, I dont have much time now, I will post my first impressions later in the evening.
  But super-quick listen tells me that SQ isnt worse what is great, and more bass I think.
  Nothing else for now.


----------



## dadong

I finally got the hd668B.... WOW i can't believe these are 60 bucks...... 

 fantastical fun even when not burned in. highs are so nice with the voshkods... defiantly a keeper and a modder.


----------



## donluca

I've given up after 100+ hours of burn in on my '73 Voskhods, now I'm burning in some Voskhods from the '87. Already they sound a little bit "softer" then their older brothers.
  I'll report back after 50h or more of burn in.
   
  The french EF91 tubes still aren't here


----------



## dadong

i know the wait is hard my 80's voskhods still haven't arrived yet. waiting on ef91's m8100 and 55's raytheons.
   
  this is hard ... i also ordered a Valab nos dac.. hope it does well with my system


----------



## vabch22

I just got a used LD i+ and was looking at trying some tubes. I've always used SS amps, so I am new to vacuum tubes. I keep seeing everyone mention the Voskhod's, but do not see the actual 6ZH1P-EV model listed anywhere. Is it the same thing as the 6J1P-EV ones? Also, what is the difference between the ones manf. in the 70's and 80's? I tried finding them on Yen Audio's ebay store, but no luck. Thanks


----------



## dadong

http://www.ebay.ca/itm/2x-Voshkod-6ZH1P-EV-Matched-Pair-Little-Dot-Amp-III-IV-/290613497027?pt=Vintage_Electronics_R2&hash=

 from yen audio... i got mine when they were 24 dollars, which is still overpriced but hey... i learned from that..

 if you keep looking around ebay i'm sure you can find better deals on it. 
   
  Like this:http://www.ebay.ca/itm/6J1P-EV-EF95-6F32-Pentode-Tubes-Lot-10-NEW-/160627769132?pt=LH_DefaultDomain_0&hash=item2566293f2c#ht_955wt_905

 from what i can understand  6ZH1P-EV = 6J1P-EV there isn't a difference. as for 70's vs 80's I hear that the 70's are better built and have brighter and more detailed highs. I'll say more when my 80's voshkods arrive.....
   
  but do get the voshkods... it's cheap and one of the best upgrades you can get for you ld amp.


----------



## kyledotroberts

LittleDot DAC_1 + Mk IV here - So far very impressed (subscribing to this thread!)


----------



## HeatFan12

Quote: 





vabch22 said:


> I just got a used LD i+ and was looking at trying some tubes. I've always used SS amps, so I am new to vacuum tubes. I keep seeing everyone mention the Voskhod's, but do not see the actual 6ZH1P-EV model listed anywhere. Is it the same thing as the 6J1P-EV ones? Also, what is the difference between the ones manf. in the 70's and 80's? I tried finding them on Yen Audio's ebay store, but no luck. Thanks


 


 Congratz....You have three families of tubes to try out.  If you are able try and get from the three families.  The 408As go up and down in price.  There are 6028s (408A) that are not expensive at all.  The EF91 & 92 families have great sounding tubes as well...
   
  Enjoy!!!


----------



## vabch22

Thanks for the links and suggestions guys. I just picked up a matched pair of the 6J1P's 70's since they can be dropped in without any jumper changes from the 6JI stock and are only about $20 shipped. From what I've read it should be a nice little cheap upgrade. I'll look into the 408a's and Mullard's also.


----------



## mmlogic

I just purchase a Little Dot MK6, currently using RCA 6AS7G and Valvo 6SL7 Jan，all sound great until I listen to John Mellencam，Just not enough bass attack, I will get a pair of KenRad VT-229 lately, may be it will help. 
  Meanwhile I am looking for Tungsol 7236, and they are really hard to find.


----------



## vabch22

What is the difference between the Sylvania GB 408a's and the GB 5654?


----------



## HeatFan12

Quote: 





vabch22 said:


> What is the difference between the Sylvania GB 408a's and the GB 5654?


 


  Different tubes altogether.  The 5654 is from the EF95 / 6AK5 / 403A/B/ 6096 / 6Zh1P-EV / CV4010 / M8100 etc...
   
  408a / 6028


----------



## Categg

Hey guys i just bought the Little Dot Mk IV SE and i see all this raving over the voshkod 6ZH1P-EV. Just wondering how big of an improvement it is over the stock CV4010, anyone can drop any comments?


----------



## dadong

Holy crap... something just happened to my Voshkods... ever since last week i've noticed something different about them... The soundstage widened to a noticible degree than when I had them for the first couple of weeks. highs are not as bright and more tamed and bass remained pretty much the same. My guess these are fully burned in now and they've pretty much became different monsters than when I first got them. 
   
  So I guess what was said about the voshkod and the 120+ hour burn in was true.. these take a while to open up.


----------



## mordy

My assumption of this blog is that various people honestly share their experiences with various tubes for the benefit of the group. While there always are differences of opinion, and different equipment reacts differently to different tubes, some general conclusions that apply to the majority can be drawn.
   
  Originally AlexRoma reported on the effect of the extra long burn-in of the Voskhods. I took the trouble to burn them in the extra hours up to 120, and also confirmed the change to a more mellow presentation. Nevertheless, the Voskhods even though highly rated, don't sound as good as other tubes with my speakers in the system I use.
   
  Somebody on this forum did not like my opinion and used unacceptable language. Head Fi has very clear rules that there is no room for bad language. BTW, one  cure for this is to go to that individual's profile and block it from appearing when you access the thread. In this way you cannot see his comments.
   
  Nevertheless, I can't dismiss all the people who think the the Voskhods are the best, so I ordered the gold grid version. They have not arrived yet, but I will let you know how they fare in my system.
   
  Here is a seller with a low starting price if you are interested in these tubes:
   
  http://www.ebay.com/itm/4x-MATCHED-TUBES-6J1P-EV-GOLD-GRID-6J1P-EF95-6F32-6AK5-NOS-80s-/250898160881?pt=Vintage_Electronics_R2&hash=item3a6ab21cf1


----------



## markkr

Quote: 





mordy said:


> Here is a seller with a low starting price if you are interested in these tubes:
> 
> http://www.ebay.com/itm/4x-MATCHED-TUBES-6J1P-EV-GOLD-GRID-6J1P-EF95-6F32-6AK5-NOS-80s-/250898160881?pt=Vintage_Electronics_R2&hash=item3a6ab21cf1


 


  Thanks for sharing!!


----------



## donluca

Hey mordy, I can say that my Voskhods from the '73 didn't change sound signature after more than 100 hours of burn in... now I'm burning in some Voskhods gold/platinum grid from the '87 and sound a bit more tamed on the highs... will report back when they'll have at least 50 hours on them.
   
  BTW, today arrived my french EF91 tubes! Maybe tomorrow I'll give them a go to see how they perform. 
   
  EDIT: hey, it turned out that a pair of the french tube are military grade! They have the top shielded and the navy logo on them (the anchor)!

 At first they are sounding less harsh on the highs but the sound seems a bit veiled... lets see if after some burn in they get better!


----------



## dadong

okay so my m8100, 80's voshkods, mullard ef92's. all came in one go. I will post impressions as I try out these diffrent tubes.
   
  So far M8100's sound extremely smooth very nice. great seperation, good mids and fair highs. I like these already. it's very musical. 
   
  The 80's voshkods are simply amazing. before burn in they have just the right amount of treble the soundstage isn't nearly as wide as the burned in 70's voshkods. otherwise they are the same as the 70's version except a lot cheaper
   
  the mullard ef92's are quite bright but extremely detailed. the soundstage so far is around the same as the voshkods I think i'll let these burn in since i feel they have the potential to turn into somehting great.


----------



## Impulsive

dadong, thats pretty much the same experience I have because i have the same tubes as you do, but instead of EF92 i have Mullards EF91 and these are very bright.
I think I still didnt passed 120 hours burn-in time with Voskhods, because I havent been listening to music lately very much. But we will see.


----------



## dadong

hmm it turns out that the ef92's i got were the 6CQC variation by mullard. no wonder it didn't sound as good as the mullard ef95's now i went back and got the proper tubes. damn it more waiting. 
   
  now i think the mullard m8100 might be my favorite tubes of the bunch. XD damn the separation and the tight bass impact is just mouth watering.


----------



## mordy

Hi Dadong,

You are pointing out an amazing aspect of the Mullard M8100 tubes: separation and delineation of individual instruments in the sound stage. No other tube that I have tried does this as well as the M8100. In addition, on some old mono recordings (20's), these tubes will portray a limited sound stage as well. On certain recordings you can place the players right, left and center, even though it is a mono recording. 
In addition, the mid range of these tubes is beautifully warm with the glorious tube sound.
So far in my experience, the best power tube combination with the M8100s has been the OEM 6N6P-i tubes.


----------



## dadong

really now the 6n6p-i.. i might have to look into getting a few of those. I'm runninng the MKIV so stock tubes are the 6n30ps which are too damn expensive. Anyone with hands on experience on how the 6n6p-i holds up against the 6n30p in a mkiv?


----------



## mordy

I should have pointed out that I only have experience with the Little Dot MkIII. However, looking at pictures it seems that the MkIV basically is the same with higher quality components. I am not aware of a comparison regarding how the two models sound relative to each other.


----------



## dadong

Cool my EF91's came as well as 1955 raytheon ef95s
   
  so far initial impressions of of the raytheon's is that it sounds very similar to the m8100's but it has heavier bass and more recessed mids. The instrument seperation isn't nearly as good as the mullards (i've been spoiled by it) however, the highs are brighter. The tubes have a slightly v shaped curve. These are fun little tubes which will be loved by bass heads. 
   
  ah god these mullard ef91's are amazing.. just needs a bit of eqing to tame the lows (77hz area) and they become fantastic. everyone needs to check these out. they go for pretty cheap too.


----------



## donluca

hey dadong,
  I'm really interested in these ef91 mullards, the problem is that I cannot find them for cheap on the bay.
  The cheapest I've found are 6 euros each + 6 euro shipment, which breaks my valve spending rule.
  Do you get them anywhere for cheaper?


----------



## dadong

hmm when i got it i was able to win a bid for 3 of them for around 10 bucks or so, however from the looks of it there arn't any deals right now. you might have to wait a bit for them then i guess.


----------



## mordy

Hi DonLuca,
   
  dadong is absolutely right - if you want a good deal you have to be patient. If you take your time, you will find somebody who has the tubes you want and does not try to get a fortune for them.
   
  Another valuable point is: Communicate. Ask questions from the seller. Some of these people do it as a sideline and hobby and like to hear from people. In several instances the seller threw in extra tubes in the sale after I told him that I have this little amp that only takes the 6AK5 "peanut" tubes and that I cannot really use the other 200 tubes he has for sale.
   
  One gentleman that sold me several tubes told me that he restores old tube equipment and suggested that I try a tube that is an equivalent to the 6AK5. (A friend of his had told him that it would give better bass than the 6AK5.) This tube is called 6AJ5 which is an older tube than the 6AK5.
  I asked David Zhe Zhe of Little Dot about it, but he said that he has no experience with it and cannot recommend it.
  I kept on looking at the specs, which were almost identical to the 6AK5 with the same pin out. Another friend (a retired electronics engineer) thought that it would work, but based on the specs the gain would be a little lower, which just would mean that I would have to turn it up a little more. (Correct assessment)
   
  I decided on looking for Tung Sol tubes since I only have good experiences with them. After a couple of weeks I found a seller that  met my buying criteria; $8 for two tubes, including shipping. I popped in the tubes. Would the thing work? Explode? Don't worry, everything is fine.
   
  The gold grid 6N6P sounded a little soft with these tubes, so I put in the OEM 6N6P-i power tubes. First impression is very positive: Nice fat bass, very good mid range and crystal highs. The sound is very nice and very listenable - will let you know further impressions when I have more time on these tubes.
   
  So if the tube rolling bug bites you, you may want to give these a try. There are many US manufacturers that made these tubes. No $68 tubes here, because there is almost no market for these tubes.


----------



## donluca

Thank you mordy, I'll definitely look after your suggestions!


----------



## dadong

http://www.ebay.ca/itm/Mullard-EF91-vintage-valve-tube-x-2-International-postage-available-/180735805195?pt=UK_Consumer_VintageAudio_RL&hash=item2a14b1870b#ht_500wt_1413
   
  yo donluca check this out...
   
  Edit: btw anyone heard of the mullard stc ef91 valves??? i got a pair along with my normal ef91's and they are pretty amazing too.


----------



## donluca

hey thank you dadong, I added them to the list under observation! I hope I can get them!


----------



## benzoylmethyl

I just got a chance to roll in a set of Voshkod 6ak5w's that I got from my dear friend DanPluck into my Hifiman EF2A.  I know it's not an LD, but the tubes are compatible and this is where he was originally describing them. I am always highly skeptical of anyone who says that any change to an existing piece of equipment "completely alters" the sound of a set of headphones--because it doesn't.  I didn't pay for these, so there's no chance of money influencing my opinion.
   
  I have to warn you, I'm really not very good at describing an audio experience, but I'll give it a shot.
   
  I've been using a set of Mullard M8100s for the past 4 months since I got the EF2A, and I have to say that I like the Voshkods better.  They seem more...authoritative.  The differences between them and the Mullards are subtle but noticeable.  Bass extension is noticeably better.  My 1964Q's have proven their ability to reach down to 20hz, where I can't even hear but can feel my ear hairs jiggle; with the Mullards, they rolled off at about 32hz or so.  The Voshkods don't "add" any bass...my initial impression is that there might be a very thin hair less quantity, but it feels more robust and the EF2 can push the Q's down to 22-24hz now.
   
  Mids are just as smooth as they were with the Mullards, but the Q is mid- and bass-centric.  It would take a lot to screw them up.  The highs don't really seem any different either...the upper midrange may have received a slight bump, as female vocals in the lower registers seem a bit more forward.
   
  Imaging seems a bit better, too.  The soundstage has the same depth and width, but it's more noticeable now...i'm assuming it's due to better instrument placement.  There's very little muddiness, even in complex metal tracks.  The Q doesn't lend itself to muddiness, but it will let you know immediately if the source isn't up to the task.  The Voshkods seem like they offer even better separation in complexity.
   
  I haven't noticed any additional detail retrieval.  These are very revealing headphones by default.
   
  ...I need to read more on the Science of vacuum tube amplifiers.  I'm not entirely sure how this little tube getting all hot and exciting some electrons can possibly make any difference in the frequency response, much less in the unmeasurable objective qualities I just mentioned.  But I guess it did.  I've spent more than enough time with the Mullards (that I _did_ pay for) and the rest of my current setup to be able to tell when things change.


----------



## donluca

Guys, I've snatched a super offer on the bay: 4 mullards m8083 (the seller says they are of the cv4014 type but can't find that on the image provided) for 14$, free shipping, that makes them 2,50 € each! I've found my bargain!
   
  He has more here 
   
  http://www.ebay.it/itm/Mullard-M8083-CV4014-ruggesided-EF91-Racal-RA-17-qty-4-in-a-lot-free-ship-/230690833481?pt=Vintage_Electronics_R2&hash=item35b63ec449#ht_500wt_1048
   
  if someone is interested.
  Can't wait to have them in my hands!
   
  And it's true: patience goes a long way on tube shopping!


----------



## DanPluck

Quote: 





benzoylmethyl said:


> I just got a chance to roll in a set of Voshkod 6ak5w's that I got from my dear friend DanPluck into my Hifiman EF2A.  I know it's not an LD, but the tubes are compatible and this is where he was originally describing them. I am always highly skeptical of anyone who says that any change to an existing piece of equipment "completely alters" the sound of a set of headphones--because it doesn't.  I didn't pay for these, so there's no chance of money influencing my opinion.


 

  Glad you enjoy them, that wasnt too long considering they practically went around the world twice


----------



## benzoylmethyl

Quote: 





danpluck said:


> Glad you enjoy them, that wasnt too long considering they practically went around the world twice


 


  Hah!  Actually, I posted that after I got home from my R&R.  I received them before I left, near the end of September!  Thanks again, man.


----------



## mordy

Hi Benzoylmethyl,
   
  Been thinking about you comment of being skeptical when somebody says that some equipment change completely alters the sound.
   
  IMHO it really depends on what kind of person you are; what you really like. Let's use a car as an example: Car A drives fine and holds the road well - you can take a certain curve at 40MPH. Car B has a much better suspension; with this car you can take the same curve at 70MPH without the tires squealing. Now, if driving that fast at that spot does not appeal to you, then the cars are about the same to YOU. But if you really appreciate that you can safely go that much faster, then there is an enormous difference to YOU between car A and B.
   
  I like a good, detailed, tight bass when listening to music. A tube that exhibits a much better bass response means a lot to me (given that the rest of the frequency response is good), and such a tube "completely alters" the sound to ME. Somebody else may be looking for something else in the sound signature and does not care about the bass, instead focusing on sound stage or instrument separation or timbre.
   
  At the present time I am evaluating an unusual tube and I am very surprised to find that with other tubes I have missed a very detailed and tight presentation of the treble without even knowing about it. With this set of tubes suddenly I hear details in the treble that I never heard before; cymbals are stunning. So these tubes completely alters the sound to me....
   
  Happy tube rolling!


----------



## eclipes

WOW that is good price for sureeee. Plus they are the large shields too. Yen audio sells the M8083 with small shield for around 60bucks for a pair.... I bought my pair for around 30 dollars.. oh my god..
  
  Quote: 





donluca said:


> Guys, I've snatched a super offer on the bay: 4 mullards m8083 (the seller says they are of the cv4014 type but can't find that on the image provided) for 14$, free shipping, that makes them 2,50 € each! I've found my bargain!
> 
> He has more here
> 
> ...


----------



## eclipes

Oh yeah, Can anyone recommend me a pair of tubes that are a good combination with the RS1s. Currently using M8083 large shield and OP2107 opamp.


----------



## donluca

hey eclipes, what's the difference bewteen the small shield and the large shield ones? Just wondering.


----------



## eclipes

im not too sure on the details of the difference. But Yen Audio told me that large shield will face less interference than small shield. And i believe he said, it has a larger soundstage and more bass depth. Don't remember too much but it should be something like that along the line.

  
  Quote: 





donluca said:


> hey eclipes, what's the difference bewteen the small shield and the large shield ones? Just wondering.


----------



## donluca

ahhh ok, "large shield" is referred to the upper shielding of the tube, it makes sense!


----------



## mordy

I  am not so sure of this, but IMHO the difference between Mullard large shield and small shield is the size of the logo in the shape of a shield. Whether there is a sonic difference between different size logos I will leave up to you.
  It is also a well known fact that a more expensive tube sounds better than a cheaper one, at least in the eyes of the seller. Look, a Voskhod tube for $18 HAS to sound better than one for $3....


----------



## eclipes

anyone with a good combination of tubes and opamps for Grado RS1s ???


----------



## Madcatyoji

Quick question, do you still need to modify the Little Dot MkIII to accept the 6h30pi golds? I just got mine on Monday and I was wondering if they modified that since it was originally discovered it didn't work. The original discovery was in like 08 or 09 in a tube rolling thread on here, but I don't know if it is still the case or if LD modified the amps at all over the last 2-3 years.


----------



## mordy

If you have a newer model, circuit revision 2.0, (you should be able to see this by looking underneath through the slots up front) it will work.
   
  This information is on the last inside page in the manual. If you do not have a manual, you can download it from the internet.


----------



## britt2001b

I just won this on Ebay from an auction by atsitubeman1 for $14.98 plus shipping. 
   
*5654 radio tubes Sylvania Gold Brand NOS 5 pcs. = 6AK5 radio tubes *
   
  I didn't expect to win them at this price as it was the opening required bid but I just couldn't pass it up. I did want some back ups but I didn't want to pay premium prices. Mordy, you're right, if you wait long enough a deal will come your way! Thanks for the advise.
   
  They were advertised as NOS that have never been used and tested good. But, to me, the picture showed pins that weren't as "gold" as I have seen in other pictures of these tubes. Maybe they are tarnished and require cleaning? I guess I will find out when they arrive. I'm really not convinced if the gold pins add to the quality of the sound because to me, the Sylvania JAN 5654's without gold pins sound better in my Little Dot MKIII.


----------



## dadong

so i had to pitch around 40 bucks to get myself the mullard m8161 ef92's
   
  gotta say though these things are different than any other tubes i've used. Pre-burn in it was a mess. Bass over empowers everything and the soundstage is very narrow. After a while on them I found these to the most detailed of all of the tubes I have. The highs are nice but not as bright as the voskods however the detail and decay of highs are extremely realistic. It has a narrow but accurate soundstage.  My only complaint about these tubes is that the  bass might be too boomy. I would have liked to have less sub bass and more tightness. Other than that great little (big) tubes.
   
  did i mention these are extremely well built tubes. A++ for mullard on making these things straight and not buldging out like other tubes.


----------



## mordy

Finally got the gold grid Voskhod tubes. These must be what people call groove tubes because the glass envelope has three vertical grooves in the glass.
  Took the trouble to burn them in for 120 hours. These 1977 tubes definitively sound much better than the 1973 Voskhods that I could not get to like. The gold grid ones have excellent bass and treble extension, with a forward and detailed sound, but not as warm as the Mullard M8100/CV4010. Very good sound stage, however,  the Mullards separate out the instruments more. The gold grid tubes have an extra energy in the low bass and in the treble, and I can understand now why they are very highly regarded. These tubes are among the best in the EF95 family.
   
  Below is a link to the ones I bought; there are other sellers on Ebay of these gold grid 6J1p-EV tubes, and the prices are reasonable
   
  http://www.ebay.com/itm/2-pc-6J1P-EV-EF95-6F32-6AK7-Gold-Platinum-grid-NIB-/130436695928?pt=Vintage_Electronics_R2&hash=item1e5ea20778
   
  Be prepared to wait; the tubes took almost one month from Russia to the US.


----------



## donluca

Hey mordy,
   
  I tried that tubes as well and couldn't like them as well due its harsh highs.
  As of now I'm good with the French 6AM6S tube (EF91). They have tamed the highs a bit and have good bass and warm mids.
   
  I'm still waiting for the mullards M8083 to arrive: we had several areas flooded in Italy and the post service has suffered a bit methinks.
   
  I hope to get them by the end of this week so I can report back.
   
  Meanwhile I'm trying to solve the brightness problem in the sound changing my DAC going for a total vintage equipment with a NOS DAC (probably the Valab one).


----------



## mordy

Have you tried to tame the highs with different driver tubes? I have good luck with the 6N6P standard and (even better) gold grid versions. These are available on Ebay from the East Bloc for modest prices, and compared to the OEM 6N6P-i tubes they tone down the highs.


----------



## eclipes

the mullards m8083 are really good tubes especially paired up with OPA2107 opamp
	

	
	
		
		

		
			




  
  Quote: 





donluca said:


> Hey mordy,
> 
> I tried that tubes as well and couldn't like them as well due its harsh highs.
> As of now I'm good with the French 6AM6S tube (EF91). They have tamed the highs a bit and have good bass and warm mids.
> ...


----------



## donluca

I have a little dot mkII, no opamps for me! 
   
  Yeah mordy, I have the gold grid 6N6P and they gave a little bit of boost on the low end but did nothing really for the highs.
   
  But I'm quite sure that the problem is with my DAC.
   
  The Mullards M8083 (CV4014 military variant) arrived today and even now they are sounding pretty sweet in my ears, I'm sure they'll get just better and better with some burn-in... maybe I've found the tube for me.


----------



## Enthusia

I just wanted to give a quick shout out to Yen Audio. I bought the Voshkod 6ZH1P-EV which are recommended in this thread by the OP. I recently had a problem with a little crackling in one of the tubes and they immediately agreed to send me new ones once I send the defectives one back. 
   
  I am now listening to the stock Little Dot MK III tubes and only now have I realized how bad they sound. One thing that stands out when compared to the Russian tubes is that in the stock tubes, the voices sound hollow. Female vocals sound like someone is singing to you down from a narrow hallway. I can definitely say the sound is less intimate, it sounds more digital and shrill. Soundstage is also not as wide or as deep, you can definitely feel a more in head experience than an outer head experience.


----------



## Tribbs

FYI, my favorite tube and opamp combination in my LD I+ with my Grado 325i turned out to be
  the Russian Восход 6Ж1П-ЕВ / Voskhod 6Zh1P-EV tubes with LME49720HA opamp.


----------



## donluca

Guys, I'm writing just to say that I think the EF91 CV4014 Mullards is the best valve for me on my LD MKII.
  I just love how they smooth the harshness in sound and the sibilance as well.
  They may not be the best ones in details and speed (the Voskhod is the king there) but they are very musical and not fatiguing.
   
  Anyway I'll be changing my DAC soon, so I may change idea somewhere in the future.
  But for now, long live the CV4014 Mullard!


----------



## audiophile noob

Quote: 





> Originally Posted by *mordy* /img/forum/go_quote.gif
> 
> <snip>
> 
> ...


 

  
  Hey Mordy: nowhere does it say that these are Voshkods - what am I missing? 
   
  $12 shipping seems excessive - what should I search for on Ebay perhaps paying more for the tubes and less for shipping for a chance to get them sooner?
   
  Thanks!


----------



## audiophile noob

Hi Enthusia: What year were your tubes manufactured? Does anyone know if Is 6zh1p-EV equal to 6j1p-EV?? Thanks!
  
  Quote: 





enthusia said:


> I just wanted to give a quick shout out to Yen Audio. I bought the Voshkod 6ZH1P-EV which are recommended in this thread by the OP. I recently had a problem with a little crackling in one of the tubes and they immediately agreed to send me new ones once I send the defectives one back.
> 
> I am now listening to the stock Little Dot MK III tubes and only now have I realized how bad they sound. One thing that stands out when compared to the Russian tubes is that in the stock tubes, the voices sound hollow. Female vocals sound like someone is singing to you down from a narrow hallway. I can definitely say the sound is less intimate, it sounds more digital and shrill. Soundstage is also not as wide or as deep, you can definitely feel a more in head experience than an outer head experience.


----------



## Tribbs

Quote: 





audiophile noob said:


> Hey Mordy: nowhere does it say that these are Voshkods - what am I missing?


 
   
http://www.ominous-valve.com/russtube.html


----------



## Tribbs

Quote: 





audiophile noob said:


> Does anyone know if Is 6zh1p-EV equal to 6j1p-EV?? Thanks!


 

 My understanding is that "_6Zh1p-EV"_ is the Russian designation for 6J1P-EV.
  In other words, they are the same tube.


----------



## mordy

Hi A Noob,
   
  If you look at your post above #237 you will see a link to a listing of all Russian vacuum tube manufacturers. Each factory has one or two logos that they use, whether on the boxes or on the tubes themselves. (Think Chevrolet Bow-Tie).
  The rocket symbol indicates the Voskhod factory. This symbol is very clearly pictured on the box for the tube, and it tells me that it is made by this factory, without being mentioned in the ad.
  As far as shopping on Ebay, I always click on the drop down menu that says "lowest price+shipping."  If the tubes cost $6 for two, and the shipping is $12, the total is the same as $18 for the tubes and free shipping. (The only difference is that the guy with the lower price pays less commission to Ebay.)
  A few times I emailed the seller that the shipping was very high for such light weight items, and asked if there was a cheaper way of shipping, knowing full well that everything goes air mail.  Some of the sellers knocked off a couple of bucks on shipping; others not. The main point is that you can negotiate.
  About faster shipping from Russia/Ukraine I don't have any advice. The items I ordered always took around 3- 3 1/2 weeks. My guess is that the customs inspections hold up the shipments.
  Tubes that I ordered from Hungary came in 7-8 days, and about the same time from Bulgaria. If a seller in Sophia, Bulgaria has the Voskhod gold grid tubes I would think that they would arrive much quicker than from Russia.


----------



## Oskari

Quote: 





tribbs said:


> My understanding is that "_6Zh1p-EV"_ is the Russian designation for 6J1P-EV.
> In other words, they are the same tube.


 

 The Russian designation is 6Ж1П-ЕВ.
   
  6Zh1P-EV and 6J1P-EV are merely transliterations of that.


----------



## audiophile noob

Thanks for the responses guys. I have learned a couple of things as well from an Ebay seller - not earth shattering in any way. 
   
  1. The -EV stands for tubes that are designed for 5000 hours of operation. Non -EV are rated for 3000 hours.
  2. There are 6J1P tubes made in the Soviet Union that are not Voskhods - there was another factory called Novosibirisk that also made them. Don't know if they compare well or poorly with Voskhod.
   
  FYI - I am trying to purchase Military grade (OTK), Gold grid, matched pair Voskhods made in the 80s based on recommendations on this forum!
   
  Quote: 





oskari said:


> The Russian designation is 6Ж1П-ЕВ.
> 
> 6Zh1P-EV and 6J1P-EV are merely transliterations of that.


----------



## Tribbs

Here are military grade, gold grid 6J1P / 6Ж1П made in the Novosibirsk factory  
   
http://www.ebay.com/itm/6J1P-GOLD-GRID-EF95-6AK5-NOVOSIBIRSK-MATCHED-PAIR-TUBE-70s-/350511816316


----------



## mordy

Hi A Noob,
   
  IMHO I would venture to say most Russian tubes were made for the military, so you don't have to look for them specially.
  It seems that only Novosibirsk made tubes with gold alloy grids.
  About the EV rating: There is another Russian higher rating called DR, which is rated for 10,000 hours of operation. I have not found any 6J1P tubes with this designation. However, there are other tubes out there in the EF95/6AK5 family that are rated for extra long life (10,000 hours). The Amperex PQ series, the Mullard Millenium series, and possibly the GE 5 Star and Sylvania Gold series, although I am not 100% sure about the last two.
  (Saw a post somewhere that Telefunken tubes have a very long life span, but I don't know if it refers to the 5654/6AK5 tubes.)
  Don't know how much this matters from a practical point of view, because so far very few of my tubes gave up. If you do a lot of tube rolling chances are that you won't play the tubes for a couple of thousand hours before you try the next one. And the next one....


----------



## audiophile noob

I was passing along some info I was able to learn (in my effort to give back) - I forgot that you guys were already experts. 
   
  I have placed an order for the Voskhods. I studiously avoided the Novosibirsk factory - because all I know is you guys said Voskhod!


----------



## cassper

Quote: 





oskari said:


> The Russian designation is 6Ж1П-ЕВ.
> 
> 6Zh1P-EV and 6J1P-EV are merely transliterations of that.


 

 Oskari, since you pointed it out I would like to correct one very common mistake in this thread regarding transliterations. The stock tube of LD mkIII is not 6N6Pi. It is 6Н6П = 6H6Pi = 6N6P. So 6N6P Gold grid is merely a version of a stock tube, not rolled tube or an upgrade per se.


----------



## mordy

Dear Cassper,
   
  Just took a look at the stock driver tube that came with my LD MKIII (bought in May 2010). The designation is 6N6П-*И* (6N6P-I). "*I* (Russian: *И*) - optimized for "pulsed" (i.e. switching) mode of operation."
  It appears to me that 6N6P and 6N6P-I are two different variants and not the identical driver tube. It also seems logical that 6N6Pi is another way of writing 6N6P-I and the same tube.
  The 6N6P gold grid tube is the same tube as any 6N6P, but the he construction is a little different, and it sounds  better to me with more punch in the bass.


----------



## cassper

Quote: 





mordy said:


> Dear Cassper,
> 
> Just took a look at the stock driver tube that came with my LD MKIII (bought in May 2010). The designation is 6N6П-*И* (6N6P-I). "*I* (Russian: *И*) - optimized for "pulsed" (i.e. switching) mode of operation."
> It appears to me that 6N6P and 6N6P-I are two different variants and not the identical driver tube. It also seems logical that 6N6Pi is another way of writing 6N6P-I and the same tube.
> The 6N6P gold grid tube is the same tube as any 6N6P, but the he construction is a little different, and it sounds  better to me with more punch in the bass.


 

 In that case you are absolutely right, 6N6P-I is indeed a different tube. Interesting information, as the Product manual and the web only mention 6N6P. Also, my mkIII, bought roughly a month ago, sports 6N6P (0381) tubes. No surprise that in your case 6N6P improved sound over 6N6P-I as these are, from available info, not very suitable for audio purposes. I have some Sovtek 6N30P-EV on the way to me, and will try also benefits of the 6N6P gold grids (cheap experiment), this is as far as I want to go with the power tubes.


----------



## olemungu

Mordy,
   
  Any difference between the gold Novosibirsk vs Voskhods based on your testing?


----------



## mordy

Dear Olemungu,
   
  Let's get it straight - I cannot compare the  Novosibirsk and Voskhod gold tubes to each other. Novosibirsk makes the various POWER tubes such as 6N6P and 6N6P-I.
  Voskhod makes different variants of the 6Zh1P-EV and 6J1P-EV DRIVER tubes.
  All in all, I found that the gold grid tubes, both power and driver tubes, sounded better in my system in comparison to non-gold grid tubes.
   
  As to the difference between 6N6P and 6N6P-I I found that the 6N6P sounded better with driver tubes with accented treble, but with other tubes 6N6P-I was better. All in all, my personal preference in power tubes is the the gold grid 6N6P.
   
  I would be interested in hearing more about your sources and reasons that the 6N6P-I is not as well suited for audio applications - I have not come across this information myself.
   
  It is worthwhile to note that the main differences and improvements in sound come from the driver tubes. The power tubes make a much smaller difference, maybe 15%. However, if they make a treble heavy tube pleasant and listenable, that could mean much more of an improvement to you.


----------



## olemungu

Since some of the sources are reasonably cheap, I will just test it out. Any major side effects of using non matching drivers? Also since some of these are sold in bulk without matching, any ways to match it at home?


----------



## Oskari

Quote: 





cassper said:


> The stock tube of LD mkIII is not 6N6Pi. It is 6Н6П = 6H6Pi = 6N6P.


 
  Quote: 





mordy said:


> It also seems logical that 6N6Pi is another way of writing 6N6P-I and the same tube.


 
   
  I believe that the "Pi" is a reflection of the fact that the Greek capital letter pi (Π) looks exactly the same as the Cyrillic capital letter pe (П).


----------



## cassper

Quote: 





oskari said:


> I believe that the "Pi" is a reflection of the fact that the Greek capital letter pi (Π) looks exactly the same as the Cyrillic capital letter pe (П).


 


  It is, indeed... In that case, however, we would be talking about 6H6Pi (=6N6P). The tube that Mordy mentioned is 6H6П-И (6H6Pi-И, =6N6P-I). There have been discussions on other forums about suitability of this tube for audio purposes due to its designation for the pulse operation and relatively short operation span (cca 500hrs). On the other hand it is being mentioned that 6N6P-I was later renamed to 6N30P, of which variants are considered to be superior to 6N6P. But again, many people have 6N6P in very high regard and consider 6N30P as a hype not worth the price premium.


----------



## mordy

Did some research the internet about the 6N6P-I tube. This tube was used in intermittent pulse mode in computers. The spec sheet rating is only 500 hours for this tube (compared to the 6N6P which is rated for 3000 hours).
  However, the consensus of many posts was that this short life span pertains to very demanding applications in tanks or airplanes, and that this tube should last much longer in audio use.
  Another very interesting aspect of manufacturing was that the factories were held to rigid government specs that could not be changed. However, in order to please customers they would change the specs to suit certain applications but not put these changes into writing. A certain customer could be reliably assured of getting the same upgraded quality from the same factory for a certain tube.
  Regarding the gold grid tubes one post stated that they do not sound different but that the manufacturing process was more difficult and rigorous, and thus the life expectancy of these tubes should be greater. (Personally, I find a sonic improvement.)
  Another interesting post mentioned that the best quality Russian tubes were made in the 60's and 70's. After the fall of communism there was much less demand for vacuum tubes, and manufacturing equipment and raw materials were sold for scrap. (Experienced workers were lost to manufacturing as well.)
  A number of posts stated that the highly touted 6H30 tubes made in the 90's and later are inferior to the early 6N6P tubes. (Early ones are very good, though, especially 6N30-DR)
  And here is a funny (and hopefully useful) quote:
 "OTK  Otbor tiehneecheskovo kachiestva - quality control level - they used the stamp OTK followed by a number. The lower number the better. The zero is if I am not mistaken the best. Zero was strictly military;  one - also military but not for nukes, and so on. I would like to read more about this aspect one day.
 Just don't forget that in the Soviet times for producing a faulty tube the worker could face 10 years in Siberian labour camp in minus 50 degrees without gloves. These times were not funny at all."
   
  I immediately ran to check my Voskhod gold grid groove tubes. Phew! OTK  1!  OK, so not OTK 0. I settle for no nukes; now I'll be able to sleep well....
  Shucks, my 1985 6N6P-I say OTK 5! And my 1978 6N6P say OTK 4! Luckily, both my 1975 gold grid 6N6P and 1975 regular 6N6P tubes don't have the OTK symbols on them - ignorance is bliss. Good night!


----------



## mordy

Tried to do a little research on the deciphering of the OTK symbol and the various numbers in the rhombus following the OTK letters.
  Basically, OTK is a Russian abbreviation for Quality Control. It is a symbol that is used on a number of products, and it is not specific to military use only. Sometimes the OTK letters are followed by a number, i.e. OTK 23. This simply means Quality Control, inspected by inspector 23.
   
  The numbers within the rhombus could be 1,3, 5, 7 and 9. The meaning of these numbers is as follows (from a Russian seller on EBay):
  [size=10pt]1 - usual OTK
 3 - usual + climate test
 5 - military
 7 - military + climate test
 9 - a special series[/size]
   
  Some of my Russian tubes have the OTK symbols printed on them and some not. Those that do not have them probably come from bulk packages that have the  OTK symbols  printed on the large box they came packaged in. (So far I have seen the numbers 1, 3 and 5 on my tubes.)
   
  My source claims that for audio use the different rhombus numbers do not matter. I would venture to guess that category 5 and 7 may be more rugged, perhaps corresponding to the W (6AK5W) in the US nomenclature, which indicates a more rugged construction for military use.


----------



## Tribbs

That's really cool.  Thanks for posting your findings.


----------



## mamaloney

So, I want to get a LD mk1+ and throw a pair of Voshkod 6ZH1P-EV tubes and an opa2107 op amp into it, how exactly do I swap these parts out? Is there any special equipment that I need or tweaking that I have to do, or is it pretty straightforward? I'm new to this kind of stuff.


----------



## cassper

Quote: 





mordy said:


> Tried to do a little research on the deciphering of the OTK symbol and the various numbers in the rhombus following the OTK letters.
> Basically, OTK is a Russian abbreviation for Quality Control. It is a symbol that is used on a number of products, and it is not specific to military use only. Sometimes the OTK letters are followed by a number, i.e. OTK 23. This simply means Quality Control, inspected by inspector 23.
> 
> The numbers within the rhombus could be 1,3, 5, 7 and 9. The meaning of these numbers is as follows (from a Russian seller on EBay):
> ...


 

 Two days ago I received 6J1P-EV with a rhombus and nr 6. They have OTK7, date code 9006. No factory logo - and they have grooves.


----------



## mordy

Don't know what the number 6 means in the rhombus - why don't you ask the seller if he knows? This kind of information is hard to find.


----------



## Napkin

Thanks for this awsome Guide! I'm also wondering like mamaloney how I'm supposed to go about when changing the tubes & OP-amp!


----------



## Tribbs

Here is a link to some Russian tube info http://www.arrakis.es/~igapop/russianotes.htm
   
  I have a Voshkod 6Ж1П-ЕВ tube with the number "47" inside the rhombus, OTK1, date(?) 07-87.
  I have two others with the number "10" inside the rhombus, both OTK1, both date(?) 03-88.


----------



## Melvins

Just received some Voshkod 6ZH1P-EV EF95's from a fellow headier and so far I adore them! Spot on description in OP's post. So smooth, very good for metal/rock and a perfect combination with the Grado's.


----------



## infinity650

Hello,
   
  please forgive my poor language - german guy. 
   
  I'm reading especially this thread for a few weeks and bought some tubes for my MK IV SE. I was lucky and got the 6H30 DR "Supertubes" right from the start. Long story, but I didn't pay the bunch of money for them.
   
  Now I want to list all of my tubes and post my impressions so far.
   
  Powertubes:

 2x 6H30-DR  -> nothing to complain about, much better than stock tubes but if it was my money I wouldn't buy them again - too expensive
 2x 6H30PI Gold-Pin  -> nothing to complan about either, in my ears pretty much the same as the "super tubes". Really recommend buying them, worth the money, acceptable price in my eyes


 Drivertubes (EF95):

 2x Voskhod 6ZH1P-EV    -> great detail and treble, nice bass. can sound harsh with bad recordings - but who listens to bad recordings 
 2x Mullard M8100/CV4010         -> lot of bass, warm and gentle. to me great for singer/songwriter, relaxed sound, less detailed, but great  
 2x RCA 5654 (Black Plate)     -> on their way to me
 2x GE JAN5654W EF95         -> on their way

 Drivertubes (EF92):

 looking out hardly for some Mullard CV4015 for a nice price! If you want to offer them to me you're welcome! I owned them but sold them with my former MK III.

 Drivertubes (EF91):

 2x Mullard CV 4014    -> on their way
  
   
  Also looking for: (offers welcome)
   
  Sylvania GB 5654 EF95
 Mullard CV4015 EF92
 Voskhod 6J1P EF95
 Tung-Sol 6AK5 EF 95
  United Electron EF92   
 Mullard CV131/6CQ6
   
   
   
  I previously owned the MK III stock tubes (really nothing special about them) and some Valvo EF92. These were pretty dark and undetailed. Maybe cool with some Bob Marley kind of music, but no good to me.
   
  That's it, let me know what you guys think and I wolud be happy to get feedback.
   
   
  Greetings,
   
  Nik


----------



## rogan

Hope this is the right thread
   
  My MK II is about to arrive, i use grado sr-125i's (32ohm i think) what gain setting shud it be on..?


----------



## rosgr63

Congratulations, enjoy it!
  I would start from the lowest gain.


----------



## Melvins

Quote: 





rogan said:


> Hope this is the right thread
> 
> My MK II is about to arrive, i use grado sr-125i's (32ohm i think) what gain setting shud it be on..?


 


  3.5. My little dot came with this gain setting already set up.


----------



## Melvins

but just to be sure I'd open that bad boy up and see what's up, the booklet that comes with the amp is pretty straight forward.


----------



## rcw9

Does anyone know if the Power Tubes were ever reviewed?  I saw one posting suggesting the 6H30P-DR's but way to expensive!


----------



## mordy

We are all waiting for the power tube review from Department of Alchemy (first post on this thread).  It's over half a year already, and I would really like to read the reviews about the power tubes!
  DOA - are you there? Could you at least give us a progress report?


----------



## infinity650

Hello,
   
  I own them. They are f* great, but way too expensive! They give just a little bit more control, a little bit more authority, but just buy the gold pins, they're nearly  as good and much much cheaper. I own them both, so I have a real comparison.


----------



## rcw9

Hi Infinity,
   
  I assume you're talking about the 6H30P-DR's?  Gold Pins.  Do you have a model number and source.  
   
  I'm new to the tubes and find it really confusing figuring out what matches to what tube etc.
   
   Any guidance is most appreciated!
   
  Thanks!


----------



## little dot

I am using the EH 6h30 gold pin power tubes in my little dot mk3  and feel there is a big difference from the stock power tubes.


----------



## infinity650

Hello
   
  I own these two pairs: 
   
  6H30-DR  
   
  http://www.ebay.de/itm/MATCHED-PAIR-6N30P-DR-6H30-Pi-SUPER-TUBES-UNUSED-TESTED-/150751226877?pt=Vintage_Electronics_R2&hash=item2319792bfd
   
  and   6H30PI Gold-Pin
   
  http://www.ebay.de/itm/2x-EH-6H30Pi-Gold-Matched-Pair-Mk-IV-SE-Little-Dot-Amp-/220845375202?pt=Vintage_Electronics_R2&hash=item336b68fee2
   
  These links are just examples, I'm neither the seller nor there's a garantee it's the lowest price right now. Just keep searching for a bargain, be patient and you'll find a good deal. EDIT: I just saw a quad of the DR Tubes on ebay for a very nice price (around 150€).
   
  Both tubes are way better than the stock tubes. You choose if a very small advance in sound quality is worth the money between these two models. Keep in mind driver tubes (perfectly discussed earlier in this thread) are much more important for the sound. It's the same thing here: look long enough for a bargain and you'll find it.


----------



## rcw9

Thanks Little Dot!


----------



## rcw9

Thanks Infinity,
   
  I just received some Mullard M8100's that I'm looking forward to trying.  I figured if I could upgrade
  the power tubes why not.  Even though it is only ~15%.  But it sounds like Little Dot and yourself
  think it's worth while so, I'll pursue that path with patience, as you suggest.
   
  Thanks again to you both.


----------



## infinity650

Hello,
   
  nice I could help you. The Mullard 8100's are a very good choice, they sound great especially with singer songwriter kind of music. There's a reason why Little Dot fits these in their MK IV SE model as "stock" tubes. Have fun while hearing and let us know how you like them.
   
  Greets,
   
  Nik


----------



## little dot

Quote: 





rcw9 said:


> Thanks Little Dot!


 


  No problem. Enjoy


----------



## fruitflavor

edit


----------



## infinity650

Hello,
   
  I bought two pairs of those Raytheon JAN-CRP a few days ago. They haven't arrived yet but I will report on their sounding by the time they're burned in and I'll have listened closely.


----------



## Bobsama

Random question: how does one remove the tubes? How are the tubes secured?


----------



## infinity650

Just push them gently left and right, pull a little litte bit while doing. Will come out easily. No rocket science at all.


----------



## Bobsama

infinity650 said:


> Just push them gently left and right, pull a little litte bit while doing. Will come out easily. No rocket science at all.




Ok; I got 'em out. I had to take off the brass shield thing and I think I heard something loose in the amp. I heard a slight buzzing from the left channel so I wanted to switch them. I know I swapped the driver tubes but I confused which power tube was left and which was right.


----------



## fruitflavor

thanks infinity.
  i really do appreciate it. Just trying to figure out if i want to use between GE, Raytheon and sylvania GB and sell of whatever I won't be using for money and to save space. But I figure that two pairs of sylvania are probably going unless they're significantly better.
   
  thanks


----------



## twc5964

Has anyone ever tried ef96/6ag5 ?  I received 4 pairs unfortunately one of the Raytheons was a dead soldier but the Sylvanias,Tung Sols,and rca's sound good and I got them for $1.50 each.


----------



## mordy

Does the 'dead soldier" have a white coating inside the glass envelope instead of silver? If not, just try the pen knife trick to scrape off the oxidation on the pins, and the tube might work.
  (The white coating indicates that the tube lost vacuum and is dead.)


----------



## infinity650

Hi guys,
   
  these days I got my Mullard EF 91s. A pair of the CV4014 (civilian version) and a pair of M8083 large shield (military). Expect from the print on these tubes, they look absolutely identical! Every detail which can be seen with bare eyes is exactly the same to me... Which leads me to the question: is there really a difference between them?
   
  Soundwise they're pretty similar to me, haven't heard them enough (still burn in, not that much time for listening) for a final judgement. Mostly heard with the M8083. With a lot more burn in time the M8083 is a little warmer and less harsh in treble. Seems to have a pretty wide soundstage and you can localize the instruments for example in an orchestra easily. Sounds very nice overall, in comparison to all good EF95 tubes the biggest difference is the wide soundstage and less "in your face" sound.
   
  Will give a big overview with my personal impressions of all my tubes ( the "big" EF95 ones, some EF91/92) and my powertubes (6H30 gold pin and the 6H30 DR "supertube"). Really really looking forward to extensive comparisons while having more time after my exams at university! 
   
   
  Greets
   
  Nik


----------



## twc5964

Quote: 





mordy said:


> Does the 'dead soldier" have a white coating inside the glass envelope instead of silver? If not, just try the pen knife trick to scrape off the oxidation on the pins, and the tube might work.
> (The white coating indicates that the tube lost vacuum and is dead.)


 


 Mordy thanks !   It's working now,however,I had to clean that stubborn tube for a solid 40 minutes and it finally worked. I took it out and put a very light coating of Deoxit on it and it stopped working again. Another 25 minutes scraping the pins then lightly tapping the tube with my finger and it's finally working. Guess this one wont have much of a life span . In fact I use a box cutter with a small thin blade to lightly scrape the pins but I've never had scrape the crap out of them like this one lol !


----------



## Oskari

Quote: 





infinity650 said:


> these days I got my Mullard EF 91s. A pair of the CV4014 (civilian version) and a pair of M8083 large shield (military). Expect from the print on these tubes, they look absolutely identical! Every detail which can be seen with bare eyes is exactly the same to me... Which leads me to the question: is there really a difference between them?


 
   
  There isn't any (if of same vintage). CV4014 is a UK government code for what Mullard called M8083, a special quality EF91.
   
  CV = common valve (see http://www.tubecollector.org/cv-valves.htm).


----------



## infinity650

Ok, thanks for the reply. Everywhere is said the military version sound better. I'll let them burn in properly and then listen to them intensively again for my judgement.


----------



## Oskari

Don't believe everything you read. What Mullard called M8083, the *UK military* called CV4014.


----------



## infinity650

Yeah, nice one!


----------



## mordy

Look, some of these tubes have decades of oxidation on them, but I am surprised that it took you so long to get it off. (Another thing I tried is to repeatedly push in and take out the tubes from the socket, but scraping with a thin blade works better.)
  Anyhow, these things make tube rolling even more interesting.
   
  How would you describe the difference in sound between 6AG5 and 6AK5 tubes?


----------



## infinity650

Hello,
   
  are we sure EF96 / 6AG5 tubes really work without problems in Little Dots?


----------



## twc5964

Quote: 





mordy said:


> Look, some of these tubes have decades of oxidation on them, but I am surprised that it took you so long to get it off. (Another thing I tried is to repeatedly push in and take out the tubes from the socket, but scraping with a thin blade works better.)
> Anyhow, these things make tube rolling even more interesting.
> 
> How would you describe the difference in sound between 6AG5 and 6AK5 tubes?


 


 I'm new to tube swapping in my 47 years as a solid state guy and tinkering with circuits. As long as I've owned the amp I used the stock tubes till recently.On that one stubborn Raytheon-the pins looked no different than any other tube I have but I understand about corrosive contacts considering these tubes may be from the late 50's-60's.Overall,the 6ag5 sounds a bit smoother in general .A slight but noticeable upgrade from the stock tubes. The Sylvania's and Tung Sols were my favorites till I got the Raytheons in there.Those to me provide a more dynamic  warm midrange sound I did'nt know existed till now but they are very microphonic. Not sure if it's just my pair or a Raytheon signature for this type of tube.


----------



## infinity650

So, once again: does anybody know for sure about 6ag5 (ef96) tubes working in the MK IV (SE) model? And if yes, which brands/types can you guys recommend best?
   
  Greets
   
  Nik
   
   
   
  By rhe way: I'm more and more pleased with the Mullard M8083s. Great tubes, nice and gentle sound overall, very good treble and detail, wide soundstage... tube rollers: give them a try, they're worth it!


----------



## twc5964

I'm sorry I cannot give you a complete answer but the Ebay seller I bought my tubes from states the 6ag5 are a good upgrade for the 6ak5. I have'nt had any problems with all the sets I own used in the MK III other than the one tube stated earlier. Unfortunately, I think he's just about out of them.I've so far tried cbs,rca,Tung Sol,Raytheon,and Sylvania-the last three being my favorites.
   
  I never received the jumpers when I bought my amp.If anyone can tell where to obtain them would be great as I'm limited to ef95/ef96 .


----------



## mordy

To the best of my knowledge the jumpers are standard and the same that come with many hard drives for different pin configurations. If you have some hard drives sitting around you may already have them, or any tech friend or computer repair shop should have them, probably for free....
  However, if you are able to use your amp I am sure that they are in place already, and you just have to move them from one setting to the other. Look in the second set of oval holes under the front of the amp and see if you can see the jumpers there. They look like little U shaped things that push on to two pins. You should see the letters EF95 if they are in the EF95 position. When you move them to other position you will see the letters EF92. (You will need a small needle nose pliers or similar to move them.)
  Good luck!


----------



## infinity650

Tube rolling becomes an addiction!   But a pretty nice one! "Tube rolling seriously doesn't harm you or others around you - just your wallet"


----------



## MIKELAP

Just got recently the LD MK3  along with it 4 unmatched 6h6p power tubes  is it ok to used them if they are not matched. or it might damage something.


----------



## elecsheep9

Rolled my first tubes on Thursday night.  Replaced the stock drivers on the MKIV (non-SE version) with the NOS GE-JAN 5654-W tubes recommended in this thread.  After about 8 hours of burn-in, I can notice a definite improvement.
   
  I felt the stock tubes rolled off the treble a tad too much, especially with the already laid back treble of the HD650s.  The GE tubes definitely add more noticeable presence and a bit (but just a bit) of sparkle to the upper range.  It still doesn't make the 650s "bright" by any stretch, but there is a bit more emphasis there.  However, still very smooth treble -- never harsh or fatiguing in any way.  Just eminently listenable.
   
  It was exactly the tweak I was looking for.
   
  The OP is also correct that the sound is quite airy.  Bass is present, but because of this airy-ness, it may actually seem, viscerally, a touch more subdued.
   
  Have been listening to mostly acoustic-y singer-songwriter stuff, and the cans just sing.  Will have to try something a little harder later on and see how they hold up. 
   
  Next on tap are the Vohkshods (which apparently, I paid way overprice for from Yen Audio, but what are you going to?)  But I think I'll live with GE's for a while yet.
   
  I can see how rolling your own can get addictive!


----------



## MIKELAP

elecsheep9 said:


> Rolled my first tubes on Thursday night.  Replaced the stock drivers on the MKIV (non-SE version) with the NOS GE-JAN 5654-W tubes recommended in this thread.  After about 8 hours of burn-in, I can notice a definite improvement.
> 
> I felt the stock tubes rolled off the treble a tad too much, especially with the already laid back treble of the HD650s.  The GE tubes definitely add more noticeable presence and a bit (but just a bit) of sparkle to the upper range.  It still doesn't make the 650s "bright" by any stretch, but there is a bit more emphasis there.  However, still very smooth treble -- never harsh or fatiguing in any way.  Just eminently listenable.
> 
> ...


 
  
  

 The Voshkod are overpriced you say i paid $36.00 from Yen Audio yesterday  for a matched pair are they cheaper elsewhere, any stores we should know about , Anybody !


----------



## elecsheep9

I paid $36 for a matched, tested pair from Yen as well.  (The GE-JANs were $18 for a matched, tested pair from ebay seller Presence01 or something like that).
   
  In the middle of this thread there is discussion that you can get alternatively branded Vokshods for significantly cheaper -- something like $20 for a sleeve of ten.  Although I don't know if those are matched and tested.


----------



## infinity650

Hello,
   
  don't know about shipping to your country especially but there are several very good offers on ebay like this. By the way: I own 3 pairs and adore them!
   
  http://www.ebay.de/itm/2-pc-6J1P-EV-EF95-6F32-6AK7-Gold-Platinum-grid-NIB-/130436695928?pt=Vintage_Electronics_R2&hash=item1e5ea20778
   
  Just go on the search for: 6J1P EV gold grid    or     6ZH1P-EV     or      6SCH1PEV     or.....  there a few more equivalents around. Just try to get some with "gold grid" "military" or "OTK" or "EV" or "EB",,,
   
  Some even say the normal "6J1P" with no special adds is far enough for great sound. these you wiill probably get for 2 Dollars each as a lot of 10 or so.
   
  I got a pair of the gold grided ones as described above for sale (and some other tubes too). So if you're interested just message me.
   
   
  Greets,
   
  Nik


----------



## mordy

Hi Infinity650,
   
  Snagged a couple of 6AG5 tubes (RCA and Tung Sol) and tried them out. David Zhe Zhe of Little Dot probably would not recommend them in his amps, but only because he has not tried them. According to a friend of mine who is a retired sound engineer the electrical characteristics and pinout are very similar to the 6AK5 tubes, and so there should not be any problems using them. Certainly, I did not have any problems with the 6AG5 tubes in my Little Dot MkIII.
  I prefer the Tung Sol tubes over the RCAs. The sound is very good overall and competes with the best of the 6AK5 tubes with a good presentation across the sound spectrum. These tubes are taller than the 6AK5 and seem very solidly built, and I would not be surprised if this construction inspired some Russian tube manufacturers.
  By all means try some and see if you like them. Be patient and look for a bargain - you could pick them up very cheap (less $2 each).


----------



## Dynasty62

In your experience, what brand EF-95/6AK5 series or 6AG5 tubes have sounded the most "tubey," ie. the warmest / exhibited the most liquid-sounding midrange?


----------



## mab1376

Quote: 





dynasty62 said:


> In your experience, what brand EF-95/6AK5 series or 6AG5 tubes have sounded the most "tubey," ie. the warmest / exhibited the most liquid-sounding midrange?


 

 I think the LM Ericsson 403b tubes are a perfect candidate for "most tubey".


----------



## fruitflavor

though i was waiting for infinity's review of GE and Raytheon JAN 5654my stock tubes on MK IIstarted to buzz on my right ear so decided to put in the GE tubes. burning in at the moment so i hope it's pretty nice. Oh and GE tubes are so much cheaper than Rayheon at half the price.


----------



## mordy

Hi Dynasty 62,
   
  For liquid, tubey midrange with great instrument separation, I found the Mullards the best.
  In the EF95 family the Mullard M8100, CV4010, CV850.
   
  In the 6AG5 family Tung Sol, but here I have very limited experience.


----------



## Dynasty62

Quote: 





mordy said:


> Hi Dynasty 62,
> 
> For liquid, tubey midrange with great instrument separation, I found the Mullards the best.
> In the EF95 family the Mullard M8100, CV4010, CV850.
> ...


 
  Would anyone know where to acquire a set LM Ericsson 403B? They seem pretty hard to find these days. 

 I really like my Amperex EF95s with the Bugle Boy logo I have in my MkIII currently. They're made in Great Britain, so I have a feeling they're rebranded Mullards. Instrument separation is great, and they definitely take the grain off of modern-day recorded music. In my opinion, they sound very smooth and are good for just about everything, however, they seem relatively neutral to my ears. I'm wondering if there's anything a tad more lush sounding in the midrange?
   
  As for Tung-Sols, I've tried five different 6AK5s and they all seemed to emphasize the wrong frequencies and had terrible microphonics... I wonder if this is the case for other Tung-Sol tube families...


----------



## mab1376

Quote: 





dynasty62 said:


> Would anyone know where to acquire a set LM Ericsson 403B? They seem pretty hard to find these days.
> 
> I really like my Amperex EF95s with the Bugle Boy logo I have in my MkIII currently. They're made in Great Britain, so I have a feeling they're rebranded Mullards. Instrument separation is great, and they definitely take the grain off of modern-day recorded music. In my opinion, they sound very smooth and are good for just about everything, however, they seem relatively neutral to my ears. I'm wondering if there's anything a tad more lush sounding in the midrange?
> 
> As for Tung-Sols, I've tried five different 6AK5s and they all seemed to emphasize the wrong frequencies and had terrible microphonics... I wonder if this is the case for other Tung-Sol tube families...


 


   
  I got mine from another head-fier, probably best to just put a wanted ad out on the boards.
   
  http://www.ebay.com/itm/Western-Electric-6AK5-403B-EF95-Little-Dot-Amp-Tubes-Matched-Pair-Tested-/251004622622?pt=Vintage_Electronics_R2&hash=item3a710a971e
   
  You can also try these, they're a close second to the LM Ericsson's.


----------



## blairfrischx

Quote: 





dynasty62 said:


> Would anyone know where to acquire a set LM Ericsson 403B? They seem pretty hard to find these days.
> 
> I really like my Amperex EF95s with the Bugle Boy logo I have in my MkIII currently. They're made in Great Britain, so I have a feeling they're rebranded Mullards. Instrument separation is great, and they definitely take the grain off of modern-day recorded music. In my opinion, they sound very smooth and are good for just about everything, however, they seem relatively neutral to my ears. I'm wondering if there's anything a tad more lush sounding in the midrange?
> 
> As for Tung-Sols, I've tried five different 6AK5s and they all seemed to emphasize the wrong frequencies and had terrible microphonics... I wonder if this is the case for other Tung-Sol tube families...


 

 I've not heard anything bad about Tung-Sol's in most families. I've also not heard much talk of them being popular in the Little Dot products (everyone loves the Bugle Boys and Mullards), so it might just be that the Tung-Sol crowd and the Little Dot crowd don't overlap much.


----------



## mordy

It is so interesting to see how different tubes sound different in different systems. I have a pair of EF95 Amperex tubes made in England which look exactly like Mullards, but they don't work for me. However, the Mullards I have sound much better. (Don't fall into the trap of Australian made Mullard look alikes that don't sound nearly as good - the letters SDA appear on these.)
  The Amperex 6AK5/5654 tubes made in Holland are much harder to find, but sound very different and have a very strong bass.
  Bottom line: You have to find the tubes that sound the best on your equipment using your own judgement. Don't know why you have such problems with microphonics - maybe you could experiment with a different placement of your amp, or maybe move something that may cause the microphonic coupling.
  In the past I have seen the LM Ericsson tubes on EBay for around $20/pair including shipping (did not sell then). Did not bite because I will not spend more than $8/tube, and preferably less than that amount for a pair.
  Found an Ebay listing from June last year that tells the story: Be patient and you will find the right price - sorry I missed it, but I was not looking then. (Hint: look for 5591 as well.)

   
   *Bread Crumb Link* 
 Consumer Electronics >
 Vintage Electronics >
 Tubes >
 Vacuum Tubes >
 Other
 


 
 
  *5591 TUBE 403B Ericson LM TUBE 5591 NOS * See original listing
  

 





 Item condition: -- Ended: Jun 21, 201119:27:41 PDT Sold For: US $3.99 [ 32 sold ] Shipping:  $1.25 USPS First Class Mail
 Item location: Frackville, Pennsylvania, United States Seller: *Member id **schadle570*  ( *Feedback Score Of* 1147






)  *



* |Seller's other items


----------



## Dynasty62

Quote: 





mordy said:


> It is so interesting to see how different tubes sound different in different systems. I have a pair of EF95 Amperex tubes made in England which look exactly like Mullards, but they don't work for me. However, the Mullards I have sound much better. (Don't fall into the trap of Australian made Mullard look alikes that don't sound nearly as good - the letters SDA appear on these.)
> The Amperex 6AK5/5654 tubes made in Holland are much harder to find, but sound very different and have a very strong bass.
> Bottom line: You have to find the tubes that sound the best on your equipment using your own judgement. Don't know why you have such problems with microphonics - maybe you could experiment with a different placement of your amp, or maybe move something that may cause the microphonic coupling.
> In the past I have seen the LM Ericsson tubes on EBay for around $20/pair including shipping (did not sell then). Did not bite because I will not spend more than $8/tube, and preferably less than that amount for a pair.
> ...


 

 Yup, I remember seeing that very listing while I was researching the 403B. It's a pity I wasn't looking for tubes then either...
  As for the microphonics, my Western Electrics, my Amperex "BB's" and Amperex 6AK5W were fine- it just seemed to be limited to the Tung-Sols.


----------



## fruitflavor

very happy with JAN GE 5654s. not much burn in and still far superior compared to stock tubes on MKII. Getting rid of all the other tubes except sylvannia and stocking up on GEs. Cheap tubes that I do like. Though it is tempting to try all the nice tubes that everyone has it'll cost too much until i finish my schooling.


----------



## infinity650

I'm still waiting for my GE JANs to arrive. In general, you're right. It would have been much cheaper to stopping the whole tube rolling thing after having heard "the best" 5654, EF91 and EF92 tube and that's it. 
   
  But it's a hobby - maximum input, minimum countable output! 
   
  Whent the time has come and I really heard and compared all my tubes after arrival, I will put double or just a little bit less favorite pairs for sale.


----------



## elecsheep9

As I said, I am very new to this whole tube and tube rolling thing.
   
  From what I have read, it is most desirable to get matched pairs of tubes.  It appears that, on ebay at least, you pay a premium for tested, matched pairs.
   
  How does one determine whether tubes are matched or not?  Also, how would one test the tubes to make sure they are still strong?


----------



## infinity650

Hello,
   
  matching means from what I know about it the electrical value of the tubes is almost the same or very close.
   
  Personally I think matching is not that important. Maybe when it comes to powertubes differing a lot but if you don't hear a difference in volume between the channels there's not a problem I think.
   
  I use mainly unmatched pairs of drivertubes and haven't had a problem with that.


----------



## mordy

Matching the tubes is very important for the people who sell tubes because they can charge much more for them. And everybody knows that a pair of matching Voskhods for $36 sound much better than a pair of unmatched Voskhods for $4.
  Did I mention that the Mullard Large Shield sound much better than the Mullard Small Shield? (or was it the other way around?)
  What about the superior sonic characteristics of black plate over gray plate? You gotta hear it to believe it! (I can't)
  And everybody knows that a $15 spray can of Deoxit removes the oxidation on the pins much better than scraping it off carefully with something you have sitting around like an old pen knife or small scissors (free). (Scraping works better)
  It is also well known that to get the most out of your $200 Little Dot MkIII you must spend well over $200 on DR power tubes to make it sound it's best. Yeah, right!
  I am using $4 driver tubes and $5 power tubes (I'll bet that the gold and platinum in them is worth something), and the sound is WONDERFUL!
  The reason you bought the Little Dot MkIII was that you wanted something cheap and good. Keep it that way!


----------



## kabes

I also agree that there is very little value to spending the extra for matched tubes at least on something like a MK III and using inexpensive tubes. Especially if they are from the same batch I don't see how there could be massive discrepancies between them. That's just like, my opinion, man. 
	

	
	
		
		

		
			




  Loving my 4 dollar unmatched JAN GE 5654W's on the MK III    
	

	
	
		
		

		
		
	


	



   
  I will concede that If I was spending the money on some DR supertubes it would be kinda silly not to spend the (relatively) little bit extra for matching.


----------



## infinity650

In my eyes there's nothing to add to the previous posting!
   
  I own and use the DR powertubes but I wouldn't spend the amount of money for them... they were included in my buying.


----------



## elecsheep9

Good to know that matching tubes is not as important as I had been led to believe.
   
  That'll make it that much cheap to stock up on tubes!


----------



## fruitflavor

though i have a tube tester i generally purchase tubes matched and just check for DOA.
  It is true that within the same batch it should be relatively similar though there are small tolerances.
  problem is people just selling same date codes and selling them as matched.
  and with most tubes rated for 5000 + hrs i'd be happy to spend 10-20 per set and buy them matched then be paranoid about left and right sounding off.


----------



## MIKELAP

Quote: 





elecsheep9 said:


> Good to know that matching tubes is not as important as I had been led to believe.
> 
> That'll make it that much cheap to stock up on tubes!


 

 That makes 2 of us i am new to tubes and fortunately didnt spend a fortune so far .I see plenty of 5654, 6ak5 at $4.00 or $5.00 each but one thing what about the power tubes i heard it is necessary to match those is that correct .


----------



## PatOMalley

been playing my mkiii for a little while and i think i've hit on a couple combination of tubes i like.
   
  stock power tubes + GE JAN5654W
  stock GE drivers are too dull for me.
  Amperex 5654 are really nice but a little thin compared to the military GEs. The GEs are detailed and add midrange oomph, that's the best way i can put it.
   
  Sovtek 6H60P power tubes + Novosibirsk 6J1P
  The 6H30 power tubes really thinned out what the military GEs were doing.
  The Russian 6j1p were on hand and kapow. Dynamic with an active populated midrange.
   
  So, Russian power tubes and drivers made for rockets equals super linearity.
  I love this thing - great head trip.
   
  The first combination is five star nice but the second whips -ass.


----------



## Namkung

awesome thread .
  got my mk iv se a few days ago and have been loving it! looking forward to "tube rolling"


----------



## lungStruck

Thanks for the very detailed and excellent reviews!  I just ordered a Little Dot I+ and also ordered a matched pair of Mullard M8083 large shields.


----------



## Categg

I just got a pair of gold-platinum grid with gold pins 6J1P-EV made in 1977. Still on the first hour of burn in but i have to say it sounds much brighter than my CV4010s, almost solid state like..  I'm wondering if this is the way it is meant to sound or further burn in will alter the character of the sound? I'm missing   the warmth of the CV4010s already..


----------



## infinity650

Your Mullards should be the warmest tubes available.The Voskhods aren't thin or bright at all burned in once. You'll probably appreciate their kind of sound while listening with them for a longer time. Just see them as an alternative, maybe better for another music genre?


----------



## Categg

Thanks for the info, i've given them around 4-5 hours of play time and probably some adjustment on my ears i think i can live with them after all. They work much better as a pre amp now due to cleaner bass and more solid highs!


----------



## madmalkav

mordy said:


> Matching the tubes is very important for the people who sell tubes because they can charge much more for them. And everybody knows that a pair of matching Voskhods for $36 sound much better than a pair of unmatched Voskhods for $4.
> Did I mention that the Mullard Large Shield sound much better than the Mullard Small Shield? (or was it the other way around?)
> What about the superior sonic characteristics of black plate over gray plate? You gotta hear it to believe it! (I can't)
> And everybody knows that a $15 spray can of Deoxit removes the oxidation on the pins much better than scraping it off carefully with something you have sitting around like an old pen knife or small scissors (free). (Scraping works better)
> ...




Can you point me to where to buy unmatched units at those prices? All I can find i.e. for Voskhods are matched sets


----------



## Categg

Try this link. 
   
http://www.ebay.com/itm/2-pc-6J1P-EV-EF95-6F32-6AK7-Gold-Platinum-grid-NIB-/130436695928?pt=Vintage_Electronics_R2&hash=item1e5ea20778#ht_5182wt_1163


----------



## madmalkav

Thanks categg, I have learned my error was looking for 6ZH1P-EV instead of 6J1P-EV.


----------



## Categg

I bookmarked that link when mordy posted it quite some time ago. And yeah after going through all the little dot threads that i only know that i should look for the original russian wordings and not the translations of it to get the good and cheap stuff! So i guess i do owe everyone who's been organizing and sharing all these info a long overdue thanks as well.
   
  Tube rolling can be obsessive.. i've already have another 2-3 different tubes on the ebay cart.. must convince myself to go slow and enjoy the burn in process...>.<


----------



## Acapella11

Thanks for the great tube reviews Dept of Alchemy!
   
  I very much appreciate the effort and recently started rolling the tubes on my MKIII. At the moment Mullard 8083s are on, which I enjoy because of their airy and open representation. I am looking forward to the Voskhods (voskhod actually means sunrise btw) to get a bit more in the bass section.


----------



## madmalkav

Ok, thanks of your tips guys I already ordered some 6J1P-EV and some JAN5654W tubes. Now I only miss ordering the amp


----------



## mab1376

I just got some Telefunken 6AK5W tubes and I'm waiting on my 6J1P-EV tubes.
   
  The Telefunken's are amazing! they're so much livelier than anything i've tried so far! Much more present mids and bass compared to the M8161 tubes i was using previously.
   
  so far i've tried:
   
  M8100
  M8161
  WE 403b
  LM Ericsson 403b
   
  Next to try on my list is M8083 and Raytheon 6AK5, does anyone have any suggestions on where to get some? My de facto source has been ebay thus far, along with the boards here.


----------



## Categg

I just got my Telefunken 6AK5W tubes a day ago and i think they have similar traits to the voskhod 6J1P-EV tubes, but granted they are not burned in yet i can't give the verdict over which is the better tube so far. So far my initial impressions for the Telefunken 6AK5W are detailed, bright, slightly recessed mids and very good bass. The bass part is where it outshines my 60+ hour burn in 6J1P-EV so far.
   
  How do you guys do burn in your tubes faster? I'm kinda worried of leaving them unattended..


----------



## Acapella11

Hey,
   
  I've been leaving the LD MK III unattached in a larger room, which is about 18 to 20C standing on the wooden floor to prevent build up of heat. This worked quite well so far. I have left it unattended over the day and been running it non-stop total times of 36 hours +. Dave however recommends to burn in only to a max of 8 hours in one session.
   
  I have been just changing M8100s after 60 hours to Voskhod 6Sh1P-EVs (= 6Zh1P-EV, 6J1P-EV, original name is [size=11pt]6Ж1Л-EB, 1975[/size][size=11.0pt])[/size]. They are on now for only 24 hours. Although the M8100 deliver a nicely balanced sound and nicely allow to localize instruments, the Voskhods delivery sweeter treble and mids are better presented. They just totally took my breath.
   
  I have had stock 5654s with mellow tuby mids but a bit dull, M8083s with amazing highs but overall not exactly balanced with mids and lows, M8100s and now the 6Sh1P-EVs, which I would highly recommend everyone for testing.


----------



## TK277

Quote: 





mab1376 said:


> I just got some Telefunken 6AK5W tubes and I'm waiting on my 6J1P-EV tubes.
> 
> The Telefunken's are amazing! they're so much livelier than anything i've tried so far! Much more present mids and bass compared to the M8161 tubes i was using previously.
> 
> ...


 

 I ordered Raytheon 6AK5 from Maverick Audio, but they weren't the cheapest at $45 for a matched pair. They ship from Taiwan and took 16 days to get here. I just got my mail this morning with the Raytheon from Mav Audio and Telefunken tubes from eBay (probably the same seller as you) so I haven't compared them yet. I'm also using a different amp, heh, but I've now got 4 sets: 6J1, GE 5-Star 5654, Raytheon 6AK5, and Telefunken 6AK5W.
   
  First impressions... The Raytheon tubes have great and refined mids, probably the clearest between 6J1 and GE 5-star, but they have pushed the outer layer of the sound stage unnaturally far away on a few tracks, it's a little weird for me. I'll be interested to see if they change over the burn-in period.


----------



## mab1376

tk277 said:


> I ordered Raytheon 6AK5 from Maverick Audio, but they weren't the cheapest at $45 for a matched pair. They ship from Taiwan and took 16 days to get here. I just got my mail this morning with the Raytheon from Mav Audio and Telefunken tubes from eBay (probably the same seller as you) so I haven't compared them yet. I'm also using a different amp, heh, but I've now got 4 sets: 6J1, GE 5-Star 5654, Raytheon 6AK5, and Telefunken 6AK5W.
> 
> First impressions... The Raytheon tubes have great and refined mids, probably the clearest between 6J1 and GE 5-star, but they have pushed the outer layer of the sound stage unnaturally far away on a few tracks, it's a little weird for me. I'll be interested to see if they change over the burn-in period.




Thanks for the input, I'm curious to see how the raytheons work out for you after the burn in period.

I'll post my comparison of the Telefunkens vs the voskhods once I actually get the voskhods and burn them in.


----------



## infinity650

Hi guys
   
  just wanted to share my impressions of my tubes so far. the overview will be updated from time to time.

 *Powertubes*       *quantity* *sound impression*       6H30 DR 2 beyond doubt 6N6P 4 very solid performance, you would miss anything if you know them exclusively 6H30 gold pin 0 nearly as good as the DR, little less authority overall       *EF 95*           Voskhod 6zh1p-EV 2 Very detailed, fine voices, bone dry bass Voskhod 6sch1p-EV (gold grid) 2 nearly the same as above, but more bass. The best EF95 tube? Lorenz 5654 3 relaxed overall sound, little lack of detail compared to the class leader RCA 5654 black plates 3 pretty thin, but detailed. Little bit lack of "soul". Pretty nice with classic music Mullard M8100 2 sounds warmer than the other tubes, absolutely toe tapping, best tube for singer songwriter Raytheon 6ak5w 2 nice voices and "flow", wide treble extension with a harshness at very high volume, wide soundstage for a EF95 tube GE JAN 6ak5w 2 very nice vocals, pretty airie sound overall. Bass is quality > quantity but for sure enough Tung Sol 6ak5w 2 good allrounder, but nothing specifically extraordinary. If look like it "colder" than Mullard sound e.g.                   *EF 92*           Mullard EF92 3 very nice overall sound. Pretty equal like the Voskhods with a wider soundstage and little less bass                   *EF 91*           Mullard M8083 2 similar to the EF 92 but lack of authority at very high volumes. Nearly my most favourite tube! Zaerix 6AM6 / CV138 2 Burn in? Nothing impressiv yet                   *EF96 6aq5*           6j3p-E 4 Burn in Haltron 6ag5 3 lot of bass, in your head sound, little lack of authority in treble


----------



## Louie from SF

Quote: 





infinity650 said:


> Hi guys
> 
> just wanted to share my impressions of my tubes so far. the overview will be updated from time to time.
> 
> ...


 
   
  I totally agree with your description of the Mullard M8100. Awesome for vocals. I bought an extra pair on eBay as soon as I received my LD MK IV SE.
   
  But since then I tried the Voskhod 6J1P-EV (also known as 6ZH1P-EV). I went back and forth between the Mullards and the Voskhods multiple times and compared multiple types of music through both my HD650s and ATH-M50s and I can tell you that I might never put the Mullards back in. At first I noticed that the LD was getting a little hot with the new Voskhod but I tried other new tubes as well and always noticed that the LD gets a little hotter than usual when burning new tubes. Things get back to normal after a few hours.
   
  The Voskhod, I think, add a lot or "presence" in pretty much everything I listened to. The bass is rich, not overwhelming, but the main difference with the Mullards is that the high mids and high frequencies have much more presence with the Voskhod. The Mullards are subdued on high frequencies and, to my taste, don't deliver when listening to jazz, classic, rock or anything with wider frequency ranges.
   
  The Voskhod are also much easier to get, are much cheaper and are built like tanks. I'm now a big Voskhod fan.
   
  Louie


----------



## TK277

I definitely like the Raytheon 6AK5 over the Telefunken 6AK5W. Better separation and detailing at the expense of some body. Telefunken didn't have anything about it that stood out to me in comparison to other tubes I've rolled.
   
  I am curious about how well you guys get the tubes in and out of your amp though. I've bent the pins on my tubes when I wiggle them to get them in or out (sans the Telefunken). I feel like they shouldn't do that...


----------



## john57

The key to remove the tubes is a bit of extra time and to use both hands. You wiggle only slightly and with the two hands you can increase the upward force and the tube will pop out.


----------



## Acapella11

Thank you Infinity650 for sharing your impressions on the tubes you rolled with us. Did you find that the Voskhod sound changed over time and not necessarily to the better?
   
  Respective the 6Sh1P-EV: I used them for about 100 hours and found that the treble is not as brilliant anymore as they were in the beginning. The tube lost some of the sparkle for me. It is possible that other production years perform differently (this was 1975 according to the leaflet, on the tube it said XII 71). I should try some from another source.
   
  Instead, I used now the GE JAN 5654Ws and the preliminary impression - after 20 hours - is that although the stage is a bit smaller, they are very airy with a nice treble presentation but also good pressure in the lower frequencies. They are very good for rock but they are versatile as well. Hopefully, the sound won't change too much as I very much like it as it is at the moment.


----------



## infinity650

I can't hear a (negative) change in sound. Maybe the less sparkle in treble is just because you get used to the sound? Wouldn't be the first time a "new thing" gets from "hell yeah!" to "just very very good".


----------



## mordy

Regarding the Voskhod tubes other reviewers have pointed out that they need a very long burn in period at the order of 120 hours, and that the sound definitively does change and becomes more mellow with less sharp highs.
   
  This has been my personal experience as well, and I like the more mellow sound better. As always, vacuum tubes react differently to different equipment, and each person has to find the combination of tubes that best suits his taste. However, some tubes excel in many setups, and it is a good idea to choose among the best rated ones, and certainly the Voskhods are in this category. 
   
  If you like more sizzle at the high frequencies, I have found that the 6N6P-i power tubes accentuate this more than the 6N6P power tubes. Conversely, if the high frequencies are too prominent with the driver tubes you are using, 6N6P power tubes will tame the high frequencies.
   
  As a side note, the best results for me occurred when I used gold grid tubes.


----------



## Acapella11

Thank you for your answers.
   
  I just got a fresh pair of 6Zh1P-EVs in. This time they are dated XI-75 and OTK is 7 (former pair was XII-71 OTK 1). I shall monitor their burning in time.
   
  Thank you also for the tip Mordy. I will look out for gold grid 6N6P-I power tubes.
   
  Btw. did you try the 6H30P tubes (6N30R with translated letters) on the LD III and what difference did it make for you?


----------



## mordy

I have only tried 6N6p-i and 6N6P power tubes (the latter with and without gold grids). I have not spent more than $8 on any tube for my $224 LD MkIII amp, and frequently much less, and I cannot see the purpose in spending $200+ on DR power tubes that only seem to give an incremental benefit.
   
  The consensus seems to be that the power tubes have much less influence on the sound than the driver tubes, maybe accounting for 15% of the difference in sound. It should also be noted the the 6N6P-i (impulse type) power tubes are rated for a significantly shorter life span than the regular 6N6P tubes.


----------



## mordy

Hi A11,
   
  Just took a look at Ebay offerings. Seems that the 6N6P-i tubes were not made with gold grids; only the 6N6P tubes. (The Voskhod tubes come as a gold variant as well). Some reviewers think that the tubes that were made in the 70's were the best quality. Oftentimes the seller has tubes from different years, and you can ask for 70's tubes.
  Here is a listing for a pair for less than $8/tube - these look the same that I bought some time back, but I was able to get a lower price by buying four of them (paid around $5 each).
   
  http://www.ebay.com/itm/Russian-6N6P-ECC99-E182CC-Double-Output-Triodes-Gold-Grid-NOS-QTY-2-/320914857399?pt=LH_DefaultDomain_0&hash=item4ab8041db7
   
  Good luck!


----------



## AlexRoma

Ebay Seller Location "Moldova, Tiraspol" ?! Haha, me luky ! I'm from Moldova too (and yes, Moldova sucks 
	

	
	
		
		

		
			





)


----------



## mab1376

Quote: 





mordy said:


> Hi A11,
> 
> Just took a look at Ebay offerings. Seems that the 6N6P-i tubes were not made with gold grids; only the 6N6P tubes. (The Voskhod tubes come as a gold variant as well). Some reviewers think that the tubes that were made in the 70's were the best quality. Oftentimes the seller has tubes from different years, and you can ask for 70's tubes.
> Here is a listing for a pair for less than $8/tube - these look the same that I bought some time back, but I was able to get a lower price by buying four of them (paid around $5 each).
> ...


 
   
   
  Are the 6N6P tubes better than 6H30PI? My little dot MK IV SE was shipped with 6H30PI and I've never rolled any alternative power tubes.


----------



## infinity650

I think you should stay with the 6H30pi instead of 6n6p. There's a reason why they're standard in the SE version.


----------



## Acapella11

Thank you for the link Mordy.
   
  Preferring tubes from EU as I don't need to pay an extra handling fee (an equivalent of about $12.50). There are some offers from Bulgaria I will check out.
   
  The new Voskhods (75s) are burning in and sound great, let's see how they change.
   
  Was just contemplating the 6H30Ps, but probably nothing to worry about.


----------



## mab1376

Quote: 





infinity650 said:


> I think you should stay with the 6H30pi instead of 6n6p. There's a reason why they're standard in the SE version.


 
   
   
  That's what I figured, and there's no way I'm splurging on the DR tubes.


----------



## spiderking31

I'm very happy that you reviewed all these tubes!, and those reviews have gave me a decision on what tubes I want! Thanks a million my friend...

Spiderking31


----------



## Acapella11

After a bit of listening with my AKG Q701, I am just updating some impressions of tubes I heard on the LD MKIII.
   
  Power tubes:
  I recommend to test 6N6P-I power tubes. For me, compared to 6N6P, the sound is more relaxed, giving more bass and most importantly a less sibling sound. The stage gets a bit smaller, the presentation is bit more "into the face" with a little loss in precision. Still, overall I really love their sound signature. Mine were from 1985, not sure how much of a difference that makes. The change from the 6N6P away was quite appreciated and even if the total change may be less than when changing driver tubes, it is noticeable and made sense to me.
  I am waiting for 6N30P-EV tubes.
  
  Driver tubes:
  There were a lot of recommendations for Voskhod 6J1P-EV but I would like to bring attention to a tube, which is not mentioned that often:
  JAN 5654W: The Sylvania (black plates, halo getter) has a slightly darker sound compared to the GE (grey plates, halo getter). Overall, the sound is well balanced and open with natural mids and a very nice treble presentation, which is not sibling, Lower frequencies are a little more prominent with the Sylvanias. The combination of 6N6P-I with GE JAN 5654W is a great one for treble lovers, mids and bass are fine too, but the signature is surely on the brighter and transparent side. 6N6P-I with Sylvania JAN 5654W give a more balanced sound in terms of frequencies and are my favourite for the Q701 so far.
  I found the treble more airy than with my 100 hour Voskhod 6J1P-EV (1971, 1975), the mids more forward sounding, the bass a bit lesser but punchy and the stage a little smaller.


----------



## Categg

Sounds like the Sylvania JAN 5654W is something i gotta try out next. I have the Telefunken 6AK5W but from your description it looks like it's similar sounding to the GE JAN 5654W, albeit with more bass presence. Instruments and voices really seem to pop out from the space around me the bass is really punchy! Only downside to me is that it sounds slightly brighter on the top end and i'm trying to find something that retains the quality of the telefunkens while not being piercing to the ears.


----------



## spiderking31

I just ordered the Jan5654W tubes for my little dot mk3....and man, can't wait to get them! Looking forward to it!


----------



## Acapella11

Categg,
   
  This is exactly what I thought about the GEs compared to the Sylvanias and this is why I appreciate the Sylvanias and would recommend trying them.
  Which power tubes do you use?
   
  Enjoy the tube rolling Spiderking31. =)
   
  PS: Btw, the JAN 5654(W) range is quite large. There are RCA, Tung Sol, Raytheon and Philips too.


----------



## spiderking31

Just got my ge Jan5654W tubes, and listening to them now....and they sound awesome with the live version of pink Floyd! The bass was there, treble is amazing, and so are the mids! Soundstage is good too, but like others said....I'm gonna have to burn them in  this should be fun! Lolz


----------



## spiderking31

And I shall enjoy acapella11!!  sounds brawlick already!


----------



## spiderking31

Love the review! And now finally am listening to my Jan5654W driver tubes, and in love! Thanks!


----------



## spiderking31

Can anyone tell me how long it'll take for my new Jan5654W tubes to be fully burnt in? Thanks everyone!


----------



## HeatFan12

Quote: 





spiderking31 said:


> Can anyone tell me how long it'll take for my new Jan5654W tubes to be fully burnt in? Thanks everyone!


 
   
  Give it at least 20-50 but more importantly, don't wait and enjoy it in the meantime, when it gets there it gets there.  I enjoy tubes right out of the box and love hearing the slight changes as they progress, but don't lose time waiting to get there...
   
  Cheers


----------



## Categg

Acapella 11,
   
  Am using the stock Electro Harmonix 6H30Pi Gold tubes that came with my Mk IV SE. Seems like it should be the best value option around so i don't think i'm gonna roll that to the DR tubes.


----------



## Acapella11

Spiderking31,
   
  Great you like them and thanks. For the burn in, HeatFan12 answered that one already, only Voskhod 6J1P-EV can take up to 120 hours.
  For the JAN5654Ws I did not think it took overly long. 20 to 30 hours it was, I'd say.
   
   
  Categg,
   
  Sorry, I did not read your sig properly (MK IV SE). The 6H30Pi Gold tubes have been reported to be an excellent choice, better than 6N6P or 6N6P-I, only haven't heard them yet. Ordered a pair of 6H30Pi-EVs, which I am still waiting for. The intention of my question was directed towards choosing between 6N6P and 6N6P-I, just to close the case.


----------



## spiderking31

Heatfan, I appreciate the feedback! And now I know it won't take forever! Thanks a ton!

Spiderking31


----------



## spiderking31

Acapella, thanks for the advice though! Greatly appreciated by everyone! Thanks again, 

Coury


----------



## hwy61

looking for 6zhip -ev voskhod  matched pair .....no luck so far with google .....are they still available ?


----------



## hwy61

Quote: 





hwy61 said:


> looking for 6zhip -ev voskhod  matched pair .....no luck so far with google .....are they still available ?


 
  actually i found these two....6zhip - ev pair darkvoiceamp 332 332 ....and 6zhip -ev 6ak5 6j1 yaqin buffer


----------



## Acapella11

hwy61,
   
  what you want is called 6J1P-EV or 6Zh1P-EV or 6Sh1P-EV. It is all derived from the same Russian name. Try ebay as well and recomended are those from the 1970s. I had 1971 and 1975 and found 1975 better.


----------



## hwy61

Quote: 





acapella11 said:


> hwy61,
> 
> what you want is called 6J1P-EV or 6Zh1P-EV or 6Sh1P-EV. It is all derived from the same Russian name. Try ebay as well and recomended are those from the 1970s. I had 1971 and 1975 and found 1975 better.


 
  thanks for the response Acapella11,......it turns out when i googled the tube number, i put 6zhip instead of 6zh1p....duh!.........i ended up  buying  voshod 6zh1p ev (matched pair)  1980's......and also ended up getting the russian  6n6p gold grid (matched pair)1990's.....the date wasn't shown on the sale and by the time i inquired
  the sale already went thru on ebay........i sent an e-mail to the buyer hoping to trade for the otk rhombus 5 gold grid  version 1980's.....but haven't heard back from him yet
  and pay the extra cost ......haste makes waste i reckon
  didn't see any from the 70's


----------



## hwy61

update to the post above......the e-bay seller orpheus _2005 agreed to do the exchange for rhombus 5 gold grids 
	

	
	
		
		

		
		
	


	



  i thought i knew what i needed after reading the first few pages of this thread..(that's when i did the buying)......well ... it turns out you really need to read all these post to be more informed,  with the mutitude of variations available your mind begins to bend.......
   
    big thanks to all , for the informative post


----------



## Acapella11

Respective the 6N6P-I power tubes, I have done a little more comparison with 6N6P tubes (gold grid) and it comes out that treble seems more extended as well as bass is rumblier. Treble is does not sound as edgy with 6N6P-I though. On the other hand, the stage is deeper with 6N6P, reverbs are more pronounced. 6N6P-I noticeably decrease the stage depth but make the sound "rounder".
   
  Technically, I found that that 6N6P-I tubes use 900 mA compared to 750 mA for 6N6P tubes. This is caused by changes of mechanical distances within the tube.
  Additionally, there is 68 ohm additional resistance in the cathode circuit for 6N6P-I. (Here are the details: http://www.tubes.ru/techinfo/HiFiAudio/6n6p.html)
   
  I would say say it, at least partially, sounds like the 6N6P-Is drive the AKG Q701 headphones better. Could the 6N6P-I power tubes compensate the relatively low impedance (64 ohm) of the Q701s to higher current in the output transformerless (OTL) amplification of the LD MKIII?
  
  PS: Also, I found that +5 db gain gives a punchier sound than +4 db in this setup.


----------



## mordy

Dear Acapella 11,
   
  Did you notice that the life expectancy is six times longer for the 6N6P tube compared to the 6N6p-i (3000 vs 500 hours)?


----------



## Acapella11

Dear Mordy,
   
  I did and I wasn't aware of the fact that it was that much lower :/ but I am going with it as I have them and prefer the sound at the moment =). 500 hours could be a year, considering 10 hours per week. It is not that bad for those relatively cheap tubes. As I am still waiting for the 6N30P tubes, I haven't concluded the power tubes chapter yet.
   
  Thanks for the hint.


----------



## mordy

Hi all,
   
  Sometimes you buy a tube that does not have the manufacturers name on it, but some letters are visible. I just found a little guide that identifies US manufacturers that made tubes for the military - JAN (or Joint Army and Navy tubes). May come in handy:
  
"Most tubes found today are ex-military, and carry Joint Army-Navy (JAN) designations in either a long form or an abbreviated version ahead of the tube type number. The known makers are: GE (JAN-CG or JG); Hytron (JAN-CHY or JHY); Raytheon (JAN-CRP or JRP); RCA (JAN-CRC or JRC); Sonotone (JAN-COZ or JOZ); Tung-Sol (JAN-CTL or JTL); Westinghouse (JAN-CWL or JWL)."
   
  So, if you find a 6AK5 tube where you only can read the letters CG, you know it is a GE tube; a JTL tube means it is made by Tung-Sol etc..
   
  Hope this is helpful in identifying tubes.


----------



## Categg

Good info, thanks for sharing this!


----------



## Acapella11

Thanks Mordy, very useful.


----------



## Acapella11

Just a prelimnary information: I am having the opportunity to compare
  Sylvania JAN 5654 (dark grey plates, halo getter, 1967) with
  Sylvania JAN 5654W (black plates, halo getter, probably both 1974). The "no W" tubes still have to be properly burnt in.
  Initial impressions are that they sound different: The JAN 5654 pronounces treble more, they sound a bit more spaceous (more reverb), also the JAN 5654 treble sounds harder. The JAN 5654W have more bass, sound rounder and a bit darker. So far, I prefer the black plate JAN 5654W tubes.


----------



## Categg

Is there the possibility that there's a Sylvania JAN 5654 black plate with no W, because that's what my latest ebay purchase seller described it as.


----------



## Acapella11

I think that plate and getter design are part of the development of the tubes and the "W" stands for improvement.
  Citation from thetubestore.com: "5654W (...) Replaces the 5654 tube or 6AK5-W tube types." 
   
I have not found a file describing how the improvement was conducted. So, I presume that (for Sylvania) black plates and halo getter reflect the best of these tubes in this respect. "W" describes a later tube type in general terms. It is also not clear to me whether the "W" requires the black plates or is just a mechanical durability improvement for example. You could ask the seller which year the tubes are from. I would think they are rather 70s with black plates than 60s.
  Alternatively, you could contemplate dbtubes.com to order from a variety of JAN 5654W tubes.
   
  One small information more. When comparing the GE grey plate with the Sylvania black and grey plates, the Sylvania grey plates from 1967 are darker than the GE grey plates. A seller might be tempted to call them black if he has no real black ones around. Unfortunately, I have no camera here, which could visualize the differences.
   
  Short Sylvania JAN 5654 W (1974) vs non W (1967) update after 20 hours of burn in: The "non-W" treble smoothed out.


----------



## Categg

Thanks for your insights! I guess this means that the tube hunting shall continue for now.. sticking to the RCA's 5654 for now till my Sylvania JAN 5654 arrives


----------



## Acapella11

Just another update to the Sylvania JAN 5654W vs "non-W":
  W sounds a bit fuller with more forward mids, slightly darker and houses more deep bass. The "non-W" is very nice too on the Q701, in summary the little brighter version with a bit deeper stage. I'll may come back to that later.
   
  I am curious about your impressions after listening to your new tubes Categg


----------



## Categg

My Sylvania JAN 5654s wont arrive until a week later, hopefully they'll turn out nice enough. In the meantime still hunting for a pair of 5654 W version.. dbtubes.com seems abit pricey for me at this point, if ebay fails to turn up any 5654W tubes then only i'll purchase them from that site.


----------



## Acapella11

Dear Categg, no need to worry. Sylvania 5654 (dark grey plates, halo getter) and Sylvania 5654W (black plates, halo getter) are similar in sound. With more burn in of the 5654, differences melt down. The 5654 is a bit brighter, which goes along with a little less bass extension. I could have been perfectly happy with the "non-W" if I wouldn't have known the darker nuance of the 5654W.
   
  You could ask *captainperry33* (ebay) whether he has some 5654W of choice. Looks like he got quite a stack of 5654 tubes there. Possibly, he could match them too.


----------



## Categg

It's funny since i bought my Sylvania JAN5654 from him, i never thought of asking him if he has any of the W versions though i suppose that can wait till i have tried out the non-W version first. I'm still pretty much trying to find the darkest sounding tube within the 5654 family.


----------



## mordy

Based on my personal experience and those of others on this blog, the 6N6P power tubes will help driver tubes sound less bright in the upper frequencies, compared to 6N6P-i.


----------



## RAZRr1275

what do you guys think about the GE JAN5654W vs the RCA 5456 Black plate? I'm looking for one more set to go with my Voshkod's and Mullards


----------



## Max F

Everyone really should get at least one set of EF92 and EF91 tubes.  Both these type of tubes are most likely going to be British and they have great soundstage vs the EF95 tubes.  Not saying they're better - just different and worth trying.


----------



## mab1376

I've tried some M8161 tubes (EF92) and i'll second that they're worth trying for sure.


----------



## RAZRr1275

how important is it to get a matched pair with tubes? also how big is the difference between ef95 and ef92 tubes?


----------



## HeatFan12

Quote: 





razrr1275 said:


> how important is it to get a matched pair with tubes?


 
   
   
  Very, very important RAZR, if not the tubes don't work...lol...Just kidding of course...
	

	
	
		
		

		
			




   
  I asked myself that question over and over for several years until I broke down and purchased a tube tester about three years ago...The short of it is- If one tube tests very very low and the other very high, the former will die out first and in the process bringing some channnel imbalance.  If both tubes have significant levels of juice it will not be noticeable.  Of course I'm talking about same brand, type etc....
   
  That being said, I usually buy matched pairs because that's how they usually sell them.  I have also purchased various lots with a variety of tubes and have liked to match them myself when at all possible, which was a lot of fun..
   
  In reference to other tubes, I posted in the I+ thread, there are many variants to choose from the different families.  See if you can get some 403As, CV850s, 6096CT...One of my favorite Grado tubes is the CBS Hytron JHY-6AK5.  Nothing harsh just smooooooothness....As was stated as well, EF91 & 92 are slamming as well...


----------



## nkoulban

I have just tried a pair of PSVANE 12AT7s on my LD VIIISE.  These babys blow the supplied ElectroHarmonix out of the water.  Not cheap at around $90 for the pair though.


----------



## Categg

Quote: 





mordy said:


> Based on my personal experience and those of others on this blog, the 6N6P power tubes will help driver tubes sound less bright in the upper frequencies, compared to 6N6P-i.


 
  Hi Mordy, just wondering if you have compared the 6N6P power tubes with the [size=x-small]6H30Pi and if you have, is there any other difference aside from sounding darker? From what i gathered in the thread i concluded that 1) 6H30Pi should be the best sounding power tube (putting aside the DR tubes) and 2) power tubes doesn't effect the overall sound too much. I'm wondering if my reasoning correct or that it[/size][size=small] changes with different tube combinations. Thanks a bunch![/size]


----------



## mab1376

Quote: 





nkoulban said:


> I have just tried a pair of PSVANE 12AT7s on my LD VIIISE.  These babys blow the supplied ElectroHarmonix out of the water.  Not cheap at around $90 for the pair though.


 
  Any caveats? i.e. abnormally high heat, strange gain difference, etc?
   
  I know with my M8161's the gain seemed to drop a bit, nothing to warrant not using them just a noticeable difference in volume.
   
  found some here: http://www.ebay.com/itm/Pair-Matched-PSVANE-12AT7-T-Vacuum-Tubes-/220809256839
   
  Probably won't be able to get them for a week or two. I was actually looking for an upgrade to the 6H30PI tubes without having to spend $200+ on DR tubes.


----------



## Acapella11

Categg, I have only compared 6N6P (gold and normal) and 6N6P-I using a AKG Q701. In this combination, however, the sound impact of power tubes is noticeable. I am not going to use 6N6P with this headphone anymore. Before using expensive tubes, it is an affordable experiment.


----------



## nkoulban

No noticable changes going from the EH drivers to the PSVANE drivers (In gain, heat, etc)  What I got was more detail, better sound staging, instruments sounded more real and immediate yet I still had a touch of tube warmth.  Quite an improvement in my experience over the EHs and I did not need to muck about with NOS tubes.  As I said, you do pay a premium for this.  A friend of mine who has a Zana Deux amp subjectively felt that the VIISE with the upgraded tubes was on par.  We will be looking to make a proper comparison when we get the chance.  My only caveat with the LD amp I have is that the finish on it is ok, but not great, then again you are not paying top dollar for it either.


----------



## mordy

Hi Categg,
   
  I have not tried the [size=small]6H30Pi[/size] power tubes so I cannot speak from personal experience. Based on reading blogs on this site my impression is that they are better than the standard 6N6P power tubes, but not by much, and for those who spent the money on the DR versions, the minor further improvement was not worth the extra expense over the 6H30Pi tubes.
   
  As with all tubes, different equipment responds differently to the various tubes, and each person has to try what works for them and what they are happy with. That said, if you choose from the highest rated ones you cannot go too wrong, and then it is a matter of personal taste. One area that has not been explored much is how various combinations of driver tubes and power tubes work, but most people seem to think that the power tubes only contribute to some 15% of the sound.


----------



## mab1376

I really happy with my [size=small]6H30Pi tubes, when I have some spending cash I'll pickup some PSVANE tubes and give em a try. If there is a noticeable improvement over the [/size][size=small]6H30Pi's then I'd say its worth it, as vague as that is [/size]


----------



## Acapella11

Agree with Mordy, in terms of SQ dependent of the whole chain of equipment and also the lack of experience with power/driver tube combinations.
  Although, it seems that many people just live with 6N6P and haven't tried other power tubes. I would encourage to put the "15%" to the test.


----------



## RAZRr1275

how long do tubes take to burn in? i kind of splurged and got the mullard m8100, voshkod's, sylvania 408a gold brand, and ge jan5654w and would like to hear these at full strength as soon as possible


----------



## Categg

Thanks mordy and Acapella 11. I guess since i already have the 6H30Pi tubes as the stock tubes on my LD Mk IV SE i shall only consider swapping power tubes if i exhaust driver tubes options. 

 Speaking of burn in. I stopped keeping tabs on my Telefunken 6AK5W after 200 hours of hoping that they would tame down the top end so it was a surprise when i swapped out my RCA black plate 5654 and popped them in for a friend of mine to listen to when he came over my house and found that the tube has tamed somewhat into thinner sounding but not as bright or punchy as before. I'm not too sure is this brain burn in or did the sound really changed... 
	

	
	
		
		

		
		
	


	




 Both me and my friend agreed that while it was still bright sounding it definitely didn't sound hard on the top end.


----------



## Acapella11

Updated
   
  Since the Mullard M8100 (CV4010) tubes are quite popular tubes (for a good reason), I am taking some time to share Mullard M8100 (CV4010) vs Sylvania JAN 5654W impressions.
   
  I have just dug out my Mullard M8100 (no Mullard label, CV4010, KQDD/K) and compared them to the Sylvanias. Both are quite well balanced tubes. From the sound signature, the CV4010 is warm and the reproduction of the frequency spectrum emphasizes lower frequencies. The Sylvanias highlight the treble section more, produce less "tubey" mids whilst keeping a good bass presence.
   
  Due to the warmer character and more forward mids, the Mullards engulf with an intimate and almost soothing sound, which can easily carry you away. I was ear washed by them, telling me, I am not missing any treble . The Sylvanias sound more analytical with their treble presence. This gives more metal feel to trumpets and sizzle on guitar riffs and also opens the space a bit more. Reverb effects become more apparent. The Sylvania's treble extension is relatively gentle such that it does not become fatiguing, just airier. Vocals appear not as seducing as with the CV4010 but more neutral / chiller. I guess the mids of quite a few tubes sound chiller than the M8100. In the bass section, Mullard wins as there is more bass feel. Sub-bass "surfaces" noticeably more. The Sylvanias still keep up very well, they sound a bit more on the mid bass side, which is punchy, and that is what gives these tubes an overall well balanced bass presence.
   
  In summary, I like both . Although both are good all rounders, they certainly sound different and as so often the choice is according to setup matching and preferences.


----------



## Max F

Quote: 





razrr1275 said:


> how important is it to get a matched pair with tubes? also how big is the difference between ef95 and ef92 tubes?


 
  I would just get the same type and brand of tube - preferably the same batch date.  I actually prefer a little bit of imbalance in the tubes since my right ear is weaker than my left.  I can get a more centered sound puting the stronger tube on the right side.  That's just my thing. I'm pretty anal about center imaging.  I think matching is more of a marketing tool to get more money from folks to be honest.
   
  There's a big difference in soundstage with the EF92 tubes (wider) and even more with the EF91 tubes.  The EF91 tubes may distort on low ohm cans like Grado from what i read. No problem with my HD650s.


----------



## Acapella11

nkoulban, good to hear that the psvane 12AT7 tubes are a great find for the LD MK VIIISE.
   
  Now, considering this forum is generally read by LD MKIII and MKIV users, are the 12AT7 compatible?


----------



## Categg

A quick google gave me this: 
   
   
 [size=1.09em] 12AT7 / ECC81 [/size]

  [size=small]12AT7's have a lower voltage gain than 12AX7's.  They have a higher plate current and transconductance, making it popular for guitarists who want cleaner headroom, and lower the gain in their amp. 12AT7's are also great for hi-fi applications that need a quieter tube in their circuit.  ECC81 is the European equivalent.

  [size=small]12AT7's can replace your 12AX7 or 5751 for lower gain.
 12AT7's can replace 12AY7 if more gain is desired.[/size]

   

   

  [size=small]So i'm guessing most likely its not usable in Mk III & IV.[/size]

[/size]


----------



## Acapella11

After listening a bit to the Mullard CV4010 (M8100), I remember there are also small and large shield versions.
  Which one is considered to be the best of these and why?


----------



## Acapella11

Thanks for checking that Categg, that's what I thought.
   
  In this official LD forum post http://www.littledot.net/forum/viewtopic.php?f=5&t=2195
   
  it says: "...only 6H30 or 6H6PI type power tubes are compatible."
  
  This was for LD MKIV SE and is from version 2 on also true for LD MKIII.


----------



## mordy

Hi AC11,
   
  I believe that small and large shield describes the size of the logo printed on the glass envelope of the tube,  and that it has nothing to do with the construction of the tube. IMHO it is just another piece of marketing hype to sell the tubes for more money.


----------



## viking59

thank you for this fantastic work.
   
  do you go on , with the power tubes; they are many différents super tube, but nobody explain the différences beetwen  old supertube and new, after 1990.
  thanks again !


----------



## mordy

Dear Viking59,
   
  From what I have read vacuum tubes made in Russia after the fall of the Soviet Union were not made with the same quality standards as earlier ones. Some people seem to think that the tubes made in the 70's were of the highest quality.
   
  Since the DR supertubes get such high prices it is possible that there are some fake ones as well.


----------



## Acapella11

Respective Mullard M8100
   
  Dear Mordy,
   
  1.) Apparently, I already ordered the Mullard M8100 KB/Q with logo and small name before you typed your answer:
   
  http://www.ebay.co.uk/itm/M8100-MULLARD-6AK5-EF95-E-MATCH-PAIR-NEW-VALVE-TUBE-/390429216735?pt=UK_Sound_Vision_Valves_Vacuum_Tubes&hash=item5ae7650fdf
   
  2.) Before, I got the Mullard CV4010 KQDD/K without Mullard or M8100 label:
   
  http://www.ebay.co.uk/itm/M8100-CV4010-6AK5W-MULLARD-NOS-MATCHED-PAIR-/310282214423?pt=UK_Sound_Vision_Valves_Vacuum_Tubes&hash=item483e42dc17
   
  Actually, both types are not the exactly same tube. The first one with logo has a square getter, whereas the second without logo has a halo (or O-) getter.
   
  Both sound great and not very different but I think the one with logo is airier, has more sizzle in the treble. Personally, I prefer this. The tube sounds somewhat more exciting. Now, it is on the best way to become my favourite tube . I probably gonna update this later.


----------



## mordy

Hi AC11,
   
  I have several pairs of the Mullard tubes, and as you notice, different production runs use different parts. I have not been able to find any information if the various getter types have an effect on the sound. Some are square, others rectangular, some are thinner metal, some thicker, some of the rectangular getters are bent (like the electric takeoff on a tram), and some are round or D shaped. Some Russian getters  look like a little bowl on legs.
  There is even a Tung Sol tube that has a clear top, and the getter flash (silver) is on the side of the glass, with a half moon shaped getter facing it in the middle of the tube.
   
  Another mystery area is how the Mullard tubes are coded, with the various letters and numbers. If you need a brain exercise, google the Mullard codes and try to decipher the factory codes and manufacturing months and years. Here is an example (but and educated guess):R1A4 means Made in the Mitcham factory on Jan 4, 1961. (Some letters are silk screened, others etched, and you may need a good light to see them).
   
  All these variations add to the fun of tube rolling.
  Then you have Mullard 8100 equivalents made by Mullard such EF95 and CV850....
   
  You have to try different tubes and see what you like the best, and then enjoy the music! Good luck!


----------



## hwy61

trying to date a pair of russian 6n6p otk rhombus 5 gold grid tubes .........numbers shown are  8808.........not 2008 is it ?                                                            
   
  has anyone tried rolling voskhod  6j1p's from the year 1967 ?.............


----------



## mordy

Hi hwy61,
   
  An "educated" guess would be August 1988. If you google Russian tubes you will easily find a chart with pictures of the logos on the tubes from the various factories. There is also information if they still are in business - most of them are closed.


----------



## hwy61

thanks mordy,......that's kinda what i thought ........what thru me off was the voskhod 6zh1p driver tubes show a 06-83 date, which seems to be a more logical dating
  system....
  as for the 6j1p's same deal 111- 67 (11-1-67)..... i decided to not only roll these tubes....  but also roll the dice sound-wise .....(the old yellow shipping box with the rocket logo was pretty cool too)


----------



## Acapella11

Thanks for the info Mordy.
  Very interesting how much Mullard altered the manufacturing process. Sounds like a lot to roll =). Although, I am very happy with these Mullard M8100s (square getter, small name logo) I got now, and then there is also the Sylvania JAN 5654W, which I might pop in. I think the driver tubes are sorted for me now - I am still on the power tubes for the fun of it and enjoying the music .
   
  hwy61,
  The labeling could be plant specific. I have got some Novosibirsk 6N6P with the print 1182, which I presume is Novermber 1982. These were stamped with the pentagonal symbol from the old Novosibirsk factory. The other 6N6P I have are from the new Novosibirsk plant with the wound snake like symbol. The label says 9804, which I suppose is April 1998. To top that, these newer tubes have even two stamps on it 9504 and 9508.
  Here are the logos and explanations of Russian tube factories:
  http://www.gstube.com/factories/ (in Russian) and transliterate here: http://www.convertcyrillic.com/Convert.aspx
  If you find a tube, the logo is explained. For example here for 6N6P tubes sold:
  http://www.gstube.com/catalog/?key=6n6p&submit=Find


----------



## mordy

Dear AC11,Here is a link to Russian tube logos. It is a simple and short list that will aid in identifying the tube manufacturers and it has proved useful to me.
   
http://www.ominous-valve.com/russtube.html


----------



## Acapella11

Thanks for this link mordy.
   
  Found coincidently something for the real Mullard fans between us: http://www.tubedepot.com/sw-ts-003.html


----------



## Acapella11

Time for a new LD MKIII contribution 
	

	
	
		
		

		
			




  
 I received a pair of 6N6P-IR tubes, 1974 from the old Novosibirsk plant.
  
 Compared to the 6N6P-I, these are politer in the treble, mids and bass are similar. I get the impression, they are a little more detailed, so you could imagine the spacial dimensions of heads and instruments better, somewhat more organized in presentation. I'd pair the 6N6P-IR rather with brighter presentation tubes than "tuby" ones like M8100  "no label, O-getter". For me, I'll keep them on my short list for system matching and the non-fatiguing signature is enjoyable, but for now the 6N6P-I will find their way back into the socket


----------



## KettyKrueger

Quick question, how do you change the tubes? Firm tug? 

Do they need biasing after?

Thanks


----------



## RAZRr1275

Quote: 





kettykrueger said:


> Quick question, how do you change the tubes? Firm tug?
> Do they need biasing after?
> Thanks


 
  I always do a gentle circular motion while pulling the tubes up, that gets them out nicely. Then do the same circular motion and push back down to get them back in. The little dot is a self biasing amp.


----------



## mordy

Hi AC11,
   
  I always wanted to know how the IR tubes sound - thanks for your evaluation. The R stands for increased reliability and mechanical ruggedness.


----------



## KettyKrueger

Thank you, sir.


----------



## KettyKrueger

Having a slight issue with my MKIII. I've got my Mac on full volume, and the MKIII on about 8/10 and it still isn't terribly loud. 

I've got the switches set to ON/OFF to match my DT990-250. 

Should I crank the gain up?


----------



## KettyKrueger

Double post, my bad.


----------



## Acapella11

Hi KettyKrueger,
   
  Try increasing the gain to +5 dB: switch 1 on, switch 2 off.


----------



## KettyKrueger

Thanks for that. I've just realised my system volume was quiet low, despite my iTunes volume being at max. I do wonder how I make it through the day sometimes :rolleyes:


----------



## atl5

Looking to buy a set of *GE JAN5654W* from the first page as it is well rated and I only have stock now.  Of these two auction, I'm thinking the first one is the correct one, but what is the difference between the first one and the one that says JAN JLRV?
   
http://www.ebay.ca/itm/PAIR-JAN-5654W-GE-6AK5-Vacuum-Tube-NOS-Grey-O-Getter-/200801271800?pt=Vintage_Electronics_R2&hash=item2ec0b03ff8
   
  JLRV
http://www.ebay.ca/itm/Match-PAIR-JAN-JLRV-5654W-GE-6AK5-Tube-NOS-D-Getter-Same-Code-Little-Dot-6AK5W-/200698379505?pt=Vintage_Electronics_R2&hash=item2eba8e3cf1
   
  Thanks for any help.


----------



## mordy

Hi ATL5,
   
  I would go with the first listing. Don't know what the difference is, but the first one is US made, and the second is made in Canada. (JAN means joint army and navy; i.e. a military tube.)
  There is also a GE 5 star 6AK5 tube that is rated similar to the Russian DR tubes regarding extra long life - 10,000 hours.
  Some people like the sound of the 5 star tube, but you cannot go wrong with the regular GE tubes.


----------



## atl5

For the Voshkod 6ZH1P-EV, has anyone bought and tested the version without the EB (EV).  How do they sound compared to the ones with EV that is so popular in here.
   
http://www.ebay.ca/itm/6J1P-6AK7-EF95-6F32-Pentode-Tubes-Lot-8-NOS-/180942893293?pt=Vintage_Electronics_R2&hash=item2a210970ed#ht_531wt_1271
   
  [size=medium]Also, just got 2 Mullard EF91 for $9 each with free shipping if anyone wants to get them.  Now I'm wondering if they would have accepted $7?  [/size][size=medium]



[/size]
  [size=medium][size=small]http://www.ebay.ca/itm/Mullard-EF91-6AM6S-6AM6-amplifier-pentode-tube-NOS-NIB-FREE-SHIPPING-/300659400882?pt=Vintage_Electronics_R2&hash=item4600b260b2[/size][/size]


----------



## Strangelove424

Just want to give a heads up to avoid Vaccum Tube, Inc. (http://www.vacuumtubesinc.com/). The guy who answered the phone was horribly rude about trying to find a set of JAN GE 5654Ws. He kept trying to talk over me, saying they were overrated and only for misled fools Whether they are overrated or not, his attitude was extremely condescending and he kept lecturing me like a misbehaving 2 year old. He didn't know what Mullard was, either. If you're looking for popular Little Dot tubes, this is NOT the place. You will be verbally attacked before he ever gets up to look for the tubes. I thanked him for his advice, but stated that I was more focused on finding tubes than being insulted. Then he hung up on me. It appears that even vacuum tube retailers are secretly vacuum tube-nay saying audiophile-haters. lol
   
  I should note that the guys at TubeStore, VacuumTube.net, and TubeWorld were all really nice, fast-responding, and super-helpful.


----------



## Quimi

Gracias


----------



## Munch

M8161 are definitely my favorites for my HD800 while my Hytrons (I believe they are 6ak5s) are for the HD650. They're not on the list but they are quite bright.


----------



## bxcarracer

Following this guide I was able to purchase a matching set of Tung-Sol 6AJ5from WWII and they sound fantastic. They're deep and warm. Quick question though I bought a matching pair of Voshkod 6ZH1P-EV from Yen-Audio on Ebay and on my little dot I+ with the gain at 40% I get a electric buzz/hum coming from my Grado 325is, any idea why that is? I get no humming from the Tung-Sol.


----------



## rcw9

Hi, are these compatible with the MK III ?   Speaking of the PSVANE tubes that Nkoulban had mentioned earlier.


----------



## Seadubb

Hello all, I'm new to the forum and about to buy my first upgraded power tubes for my MKiii and HD650s. Which of the following would you recommend?
   
  Sovtek 6H30Pi-EB
  Electro-Harmonix 6H30Pi
  6N30P-DR Supertube (made in at Reflector Factory in 1999)
   
  Thanks for your help!


----------



## dxanex

Great guide! I've been using the Amperex 5654 tubes in my LD MKIII for a little over a year and I really enjoy its warmth and the smooth, forward sounding mids. Sounds exceptional with classical and electronic music in particular. I would say for me, the bass extension is nice. I recently ordered a Dark Voice 3322, so I'm getting back into tube rolling and I'm already spending too much on some of these NOS tubes to try out with my new amp!


----------



## nailbunny7

Is there any real difference between these to warrant the price difference?
  http://www.ebay.ca/itm/150922345696?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649#ht_4469wt_1180
   
  http://www.ebay.ca/itm/150912716095?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649#ht_2947wt_1202
   
  One more question. Which is the best supertube to get for the Little Dot IV SE?


----------



## Seadubb

I have a similar question. I have read that the post-1992 Supertubes are not up to the standard of the older ones. How do the post-1992 Supertubes compare to the 6H30Pi-EB and the EH-6H30Pi?


----------



## mordy

Dear Nailbunny7 and Seadubb,
   
   
  I have not tried any of the super(expensive)tubes myself, but from what I have read there is a big difference between the tubes made before 1990 and after. Most people seem to say that the DR power tubes are the best, but that the price difference is not justified compared to the less expensive Electro Harmonix 6H30Pi tubes. In other words, there is a difference, but not that great.
   
  The truth is that upgrading the driver tubes will make a much bigger difference in sound than upgrading the power tubes. If you want to try that instead, I have a superb recommendation: Tung Sol 6AJ5 tubes. These sound better than anything else I tried in my system (YMMV).
  The only drawback with this tube is that it requires you to turn up the volume control a little more than the other tubes. This tube precedes the 6AK5 and uses a lower plate voltage and thus has a little less gain than the 6AK5.
   
  At the present time you can buy these tubes for around $6 each on EBay. They are somewhat rare, and I am afraid that once people discover them the price will shoot up.
   
  Good luck tube rolling!


----------



## Seadubb

Thanks, I think I will just purchase the Electro Harmonix. I have rolled a few different driver tubes, but not the 6aJ5. Looks like they are inexpensive as singles, but the only matched pair is $40. I'll have to keep my eyes open for deals on the bay. Thanks!


----------



## mordy

Here is a guy that will sell you two tubes for $19.50 or a sleeve of five for $35.45.
   
   
   
  http://www.ebay.com/itm/TUNG-SOL-JAN-6AJ5-TUBES-/400329930842?pt=US_Radio_Comm_Tubes&hash=item5d3585f85a
   
  http://www.ebay.com/itm/SLEEVE-OF-FIVE-TUNG-SOL-JAN-6AJ5-TUBES-/160904368766?pt=US_Radio_Comm_Tubes&hash=item2576a5d27e


----------



## Seadubb

Sorry to beat a dead horse...
   
  I can buy a pair of 6N30P-DR tubes from 1986 for $80. The problem is, they will not match the pair. I wouldn't hesitate to order them at that price, but I'm concerned that the lack of matching will affect the sound. Anyone have experience with power tubes that haven't been matched by the seller? Should I go for it, or play it safe and grab a pair of Electro Harmonix at the same price?


----------



## nailbunny7

I also have on last question. Any guesses on which I should get:
  http://www.ebay.ca/itm/150922345696?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649#ht_4469wt_1180
   
  http://www.ebay.ca/itm/220845375202?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649#ht_1233wt_1180
   
   
  Just for the record, I already upgraded my driver tubes to the *[size=medium]VOSHOD 6ZH1P-EV[/size]*


----------



## MIKELAP

Quote: 





seadubb said:


> Sorry to beat a dead horse...
> 
> I can buy a pair of 6N30P-DR tubes from 1986 for $80. The problem is, they will not match the pair. I wouldn't hesitate to order them at that price, but I'm concerned that the lack of matching will affect the sound. Anyone have experience with power tubes that haven't been matched by the seller? Should I go for it, or play it safe and grab a pair of Electro Harmonix at the same price?


 
  Ive always heard that power tubes should be matched not so important for the driver tubes an other thing we have to keep telling ourselves is that its only a couple hundred dollar amp . That being said i would go for the ELECTRO HARMONIX 6H30Pi gold pins if your amp is a circuit revision 2.0 or higher .Enjoy
	

	
	
		
		

		
		
	


	




       And by the way to verify if your model is 2.0 you look under on the volume side in a peep hole next to the right front rubber foot with a flash light sideways you will see littledot mk3 v.2.0


----------



## fenderf4i

I just received my first tube amp, a Little Dot I+ with EF92/6CQ6 tubes. Is it normal for these tubes to have distortion/warbling at a certain range of lower frequencies, or could there be something wrong with them? Or, is that just part of the "tube" sound?


----------



## MIKELAP

Quote: 





fenderf4i said:


> I just received my first tube amp, a Little Dot I+ with EF92/6CQ6 tubes. Is it normal for these tubes to have distortion/warbling at a certain range of lower frequencies, or could there be something wrong with them? Or, is that just part of the "tube" sound?


 
  Maybe you have to let it burn in a bit  and see later if the sound improves and is the amp set up right for your phones dont know how it is with the LD 1+ but with MK3 they are different switches under the unit for different impedance and sensitivity phones. and not shure but i think you have to remove the shell of your unit to gain access to those switches if indeed they is ajusments to be made check your book.


----------



## fenderf4i

Quote: 





mikelap said:


> Maybe you have to let it burn in a bit  and see later if the sound improves and is the amp set up right for your phones dont know how it is with the LD 1+ but with MK3 they are different switches under the unit for different impedance and sensitivity phones. and not shure but i think you have to remove the shell of your unit to gain access to those switches if indeed they is ajusments to be made check your book.


 
   
  Yes it is set to the correct settings for the EF92 tubes, and 3.5X gain. I am having to turn the volume up to 70-90% to get to a volume I like, maybe I will try the higher gain to see if that helps.


----------



## MIKELAP

Quote: 





fenderf4i said:


> Yes it is set to the correct settings for the EF92 tubes, and 3.5X gain. I am having to turn the volume up to 70-90% to get to a volume I like, maybe I will try the higher gain to see if that helps.


 
  i am using a pair of denon d-5000 with 25 Ohm impedance  and its plenty loud at 50% I guess ajusting the gain would help .


----------



## fenderf4i

Quote: 





mikelap said:


> i am using a pair of denon d-5000 with 25 Ohm impedance  and its plenty loud at 50% I guess ajusting the gain would help .


 
   
  Using my O2 amp (2.5 gain) with the same 2V source, I have tons of volume, usually run at 50% volume. Not sure why the LD is not as loud at 3.5X gain. I'll have to get a hold of different tubes to see if it makes a difference with the distortion/warbling I'm hearing.


----------



## fenderf4i

I changed the gain to 7X, and it seems to be much better. I also have a pair of Voshkod 6ZH1P-EV tubes on the way to try next!


----------



## asmoday

I have the Voshkod 6ZH1P-EV in my MkII and I really them for the HD650 and DT880.


----------



## mordy

Recently I noticed that my LD MkIII started to sound dull and more ss than tubey. At first I thought that maybe the power tubes are getting old and need replacement. However, they should last over 3000 hours and I did not think I put that much on them yet.
   
  I just pulled out the tubes and noticed that the pins looked slightly oxidized, so I switched them around and pushed them up and down a little in their sockets to scrape off the oxidation. Voila! The magic is back! Now they sound the way they should!


----------



## john57

Yes those small thin pins will oxidize. I clean the pins twice a year.


----------



## rosgr63

John do you use Deoxit?


----------



## mordy

Thanks, sounds like good advice. We should ask David to put it into the manual....


----------



## john57

[size=medium]You do not want to scrap the pins to much since it can make it oxidize faster. The only time I would scrap the pins is for first time tubes that have been in storage for a very long time. You want to use the stronger version of Deoxit. I had a spray version from Radio Shack and I spray a Q-tip and apply to the pins and reinsert it a few times in the socket. If you want a special Deoxit kit made just for vacuum tubes here is one source. [/size]
[size=medium]http://store.caig.com/s.nl/it.A/id.2644/.f[/size]


----------



## dxanex

I was surprised to see that the Amperex 5654 rated fairly low on this scale, since I've been using them in my LD MKIII for over a year. I just bought a matched pair of NOS, GE Five Star 5654 and instantly heard a difference especially in the base, very controlled but much more impact and the treble sparkles.
   
  Compared to the Amperex tubes the GE 5 stars seem more energetic. Only thing is, female vocals sound a little weird in the brief time I listened to Lana Del Rey. Sounds kind of nasally, and almost too forward...not warm and laid back like I'm used to with Amperex tubes... but maybe this will improve with some burn in? Just initial impressions and my 2 cents.
   
  Waiting for matched set of GE JAN 5654w's to get here to try


----------



## mab1376

Does anyone have a pair of Voshkod 6ZH1P-EV they want to sell?
   
  The two I've bought so far got caught up at the post office and eventually send back to Croatia. 
	

	
	
		
		

		
		
	


	



   
  Ebay also froze my account due to money my dad owes on his separate account since we have the same address.


----------



## dxanex

mab1376 said:


> Does anyone have a pair of Voshkod 6ZH1P-EV they want to sell?
> 
> The two I've bought so far got caught up at the post office and eventually send back to Croatia.
> 
> Ebay also froze my account due to money my dad owes on his separate account since we have the same address. :mad:




I really hate eBay. It's ok for buying but as a selling platform, it's become worthless. Try the for sale section on head-fi under components. Do a search there. I see all types of tubes for sale there.


----------



## Acapella11

Dear mab1376, I have send you a pm respective a spare pair I have.


----------



## MIKELAP

Was reading the thread and somebody was asking the best way to remove tubes what i do for that is to use a rubber finger the inside is just big enough to go over the driver tubes they dont slip just pull them out and for the power tubes there bigger on the outside best thing is to put 1 on each finger and grab it, the tube doesnt slip works for me.


----------



## mordy

Sounds great! What kind of store sells these items?


----------



## dxanex

Also, where did you get the tube protectors for your MKIII?


----------



## MIKELAP

Quote: 





mordy said:


> Sounds great! What kind of store sells these items?


 
  Probably office supply store.


----------



## MIKELAP

Quote: 





dxanex said:


> Also, where did you get the tube protectors for your MKIII?


 
  I made those by hand actually with a hand drill and a dremel,i saw those on the mk4 i think, liked the look. You just slip them over the tubes . For the color i put them on a stove element until they turn blue et voila.It was a pain to do but if unlike me you have a workshop and tools its half the battle.


----------



## mordy

Found a link to the rubber finger pads ($2.50/dz)
  http://www.staples.com/rubber+finger+pads/directory_rubber+finger+pads


----------



## spiderking31

Go to www.thetubestore.com they might have them


----------



## asmoday

Quote: 





mikelap said:


> I made those by hand actually with a hand drill and a dremel,i saw those on the mk4 i think, liked the look. You just slip them over the tubes . For the color i put them on a stove element until they turn blue et voila.It was a pain to do but if unlike me you have a workshop and tools its half the battle.


 
   
  They look very nice MIKELAP!!
  Very nice work!


----------



## MIKELAP

Quote: 





asmoday said:


> They look very nice MIKELAP!!
> Very nice work!


 
  Thanks man .


----------



## MIKELAP

If anybody is interested in getting Electro Harmonix EH 6h30Pi power tubes for those of you with a revision v2.0 littledot mk3  these tubes are 20% off today only price is $33.95each less 20% for savings of $13.58 on a pair at  PARTS CONNEXION . COM in Ontario, Canada


----------



## asmoday

Thats a sweet deal, but there about a week to late for me. 
	

	
	
		
		

		
		
	


	



   
  I had a power tube go bad on mine a little over a week ago and I went with the Novosibirsk 6H6P-I.


----------



## mab1376

Just ordered a pair of these to try out with my MK IV:
   
  http://www.aloaudio.com/russian-military-6x1-eb


----------



## MIKELAP

Quote: 





mab1376 said:


> Just ordered a pair of these to try out with my MK IV:
> 
> http://www.aloaudio.com/russian-military-6x1-eb


 
  Are those russian tubes compatible with the MK3 .Thanks


----------



## mab1376

yes, they're equivalent to 6AK5 tubes.


----------



## Acapella11

Thanks bxcarracer and Mordy reminding (posts 436 and 442) on the Tung Sol 6AJ5 tubes.
   
  Although, I really thought I was sorted, the tube rolling curiosity got me back and I ordered a couple of Tung-Sol 6AJ5 tubes, which were JAN CTL-6AJ5 from May 1945 (!) that makes them my oldest tubes so far. Admittedly, these are amazing tubes. They are very resolving. Also, they could be perceived as a tad bright and not exactly as warm as e.g. Mullard M8100 tubes but they are not fatiguing at all. I would rather say they are very transparent. The treble extends beautifully and the bass goes deep as well. Instrument separation is very well done and a generous but not overly large space is created. I must say, I am impressed and at the moment they seem to be stuck to the sockets... Highly recommended.
   
  The only disadvantage I could find is that they are a little sensitive. I had a l little humming in the beginning and I think the background is not exactly extremely silent but that shouldn't spoil the fun. Go and get them.


----------



## mordy

Dear A11,
   
  Glad you like the Tung Sol 6AJ5 tubes. I've tried a lot of different tubes, and for me these are the best sounding tubes. Re the hum, try switching the tubes and see if one of them is responsible for the hum (usually only hum on one channel).
  You may also want to clean the pins. Gently scraping with a little pocket knife or any other type of blade is the cheapest way and works the best. It may even be enough to just pull the tube in and out of the socket once or twice.
  In my system I listen through speakers and I turn up the volume control almost to the max on my MKIII and then I only need a low setting on my receiver volume control. If I keep the volume low on the MKIII and turn up the receiver volume high I will get some hum, but this applies to all tubes I use, so it must be my system.
  BTW, the Tung Sol 6AJ5 tubes look a little different from different years, with different plates and getters, but all sound very similar.
   
  Your description of how these tubes sound accords with my impression, and I especially love the crystal clear highs and tuneful bass and the beautiful mid range. (Sorry, Voskhod fans, but for me these are the best. However, I do recognize that people have different taste an preferences, and tubes sound different in different electronic environments.)
   
  Let's only hope that once people discover these tubes the sharks will not ratchet up the prices into the stratosphere....(These tubes are somewhat rare.)


----------



## dxanex

Since we are on the topic of tube hum, does anyone know why my RCA 5 Stars would be dead silent in my MKIII, but have a low frequency hum when in my Darkvoice 3322? Other tubes I've tried also will have a very loud hum (to the point I can't use them) in the DV that is inaudible in the MKIII. I've read some amps are self biasing so matching tubes isnt as important, but I believe the DV3322 is self-biasing...(correct me if I'm wrong)


----------



## mab1376

maybe some corrosion in the tube socket itself?


----------



## dxanex

Quote: 





dxanex said:


> Since we are on the topic of tube hum, does anyone know why my RCA 5 Stars would be dead silent in my MKIII, but have a low frequency hum when in my Darkvoice 3322? Other tubes I've tried also will have a very loud hum (to the point I can't use them) in the DV that is inaudible in the MKIII. I've read some amps are self biasing so matching tubes isnt as important, but I believe the DV3322 is self-biasing...(correct me if I'm wrong)


 

 how does one clean a tube socket? Would compressed air do the trick or is it more involved?


----------



## mab1376

I would try a super thin pipe cleaner with some deoxit spray and give it a few hours to dry upside down when you're done.


----------



## MIKELAP

Quote: 





dxanex said:


> how does one clean a tube socket? Would compressed air do the trick or is it more involved?


 
  Maybe just take a bad tube put the stuff on it put it in ,take it out repeat that severall times it would be hard to find a better pin size to get in there imo.


----------



## Acapella11

Just found a great combo, which I never tried before: CV 4015 (EF92) driver with 6N6P-IR power tubes. The IRs mild, warm, detailed and bassy sound complements the detailed and bright CV4015 very well. Together they sound neutral, natural, very detailed and very balanced. Wow, didn't quite expect that.


----------



## mordy

What sounds better to you - 6AJ5 and 6N6P or CV4015 and 6N6P-IR?
   
  (For the 6N6P I use 70's gold grid tubes)


----------



## dxanex

Quote: 





mikelap said:


> Maybe just take a bad tube put the stuff on it put it in ,take it out repeat that severall times it would be hard to find a better pin size to get in there imo.


 

 I just ordered a tube of Deoxit, so I'll give it a shot. I noticed the hum fluctuates in loudness depending on what brand tubes I have in it...could it be something is wrong with the amp or the tube sockets? Could it just be ground looping? My Little Dot MKIII was dead silent, so I'm slightly upset considering this amp is more than double the price...


----------



## wuwhere

Quote: 





dxanex said:


> I just ordered a tube of Deoxit, so I'll give it a shot. I noticed the hum fluctuates in loudness depending on what brand tubes I have in it...could it be something is wrong with the amp or the tube sockets? Could it just be ground looping? My Little Dot MKIII was dead silent, so I'm slightly upset considering this amp is more than double the price...


 
   
  Here's some instructions but instead of alcohol, use Deoxit on the tubes.
   
  http://www.ehow.com/how_7963572_clean-vacuum-tube-sockets.html


----------



## john57

If you remove the inputs does the amp still hums? If so that is not a ground loop issue.


----------



## Acapella11

What sounds better to you - 6AJ5 and 6N6P or CV4015 and 6N6P-IR?
   
  This is a very good question. I will check this out in the next days, as I haven't combined 6AJ5 and 6N6P yet. But I went through four power tubes (6N6P (gold), 6N6P-I, 6N6P-IR and 6H30-EV) with the CV4015 as I just rediscovered the amazing detail of these tubes and I can share some notes I wrote down:
  "Warm sound coloration": 6N6P-IR > 6N6P > 6N6P-I >> 6H30-EV
  "Authority": 6H30-EV (mainly mids and treble) > 6N6P-I (balanced) > 6N6P = 6N6P-IR
   
  CV4015 and 6N6P-IR give a nice amount of detail and a warm, low fatiguing sound signature. CV4015 and 6N6P-I sound a little "colder" but also "cleaner" with more authority. I suppose it is down to the overall system, which one is preferred. At the moment, I am listening to the second setup and it is very enjoyable. On the other other extreme, 6H30-EV and CV4015 give an amazing amount of detail and SQ but it is quite bright and the bass is, though qualitatively very nice, not quite well present enough for my liking.
  I will have another look at the nice 6AJ5s.


----------



## MIKELAP

Quote: 





dxanex said:


> I just ordered a tube of Deoxit, so I'll give it a shot. I noticed the hum fluctuates in loudness depending on what brand tubes I have in it...could it be something is wrong with the amp or the tube sockets? Could it just be ground looping? My Little Dot MKIII was dead silent, so I'm slightly upset considering this amp is more than double the price...


 
  This happened to me lately hum my mk3 was atop my other amp that was not on by the way which is close to my pc tower i just moved the LDOT away from tower and the hum stopped could be that or the tubes i had on a the time but i dont thinks its the tubes.


----------



## dxanex

Quote: 





john57 said:


> If you remove the inputs does the amp still hums? If so that is not a ground loop issue.


 

 Yes it does. So then, it must be an issue with the amp and not the audio chain. I will try using the deoxit on the tube sockets next. Though I realized on my AKG K702 I don't hear the hum at all. I'm very confused, I don't understand electronics so it's frustrating trying to troubleshoot it. The seller is Chinese and his English is not the best...but the humming is not bad enough to return the amp, at least not yet.


----------



## Acapella11

Quote: 





mordy said:


> What sounds better to you - 6AJ5 and 6N6P or CV4015 and 6N6P-IR?
> 
> (For the 6N6P I use 70's gold grid tubes)


 
  Firstly, I need to say that this comparison is not under best conditions, as the jumpers need to be changed between comparisons and tubes are differently loud. So, certain inaccuracies are inherently given.
   
  Dear Mordy, my gold grid 6N6Ps are from 1998. Using the HE-500, I have more resolution than before with my AKG Q701. Although LD MKIII is not quite the right match for a HE-500, differences between tubes can be nicely analyzed. Using this gear, the clear improvement comes from using the CV4015.
   
  The 6N6P with 6AJ5 has a very defined bass, nice treble extension, great mids and builds an extended audio space. The weakness comes with the resolution. It is a little like as if everything is assembled behind a thin almost transparent curtain. The sound signature is very pleasant but the focus and transparency is just second to the CV4015.
  Choice of the power tube is a matter of taste, as the 6N6P-IR gives a warm and spatial representation, but not as focused as the 6N6P-I, which extends the room lesser (less reverb e.g.). The 6N6P-I has a very clear "in-the-face" sound. I like both in their ways. The 6N6P is in between, not as warm ('seducing') as the 6N6P-IR, more definition, possibly less space. The 6N6P is a great choice, might even be the best for some. I would say, depending on the liking, resolution and brightness of your headphones and dac you would favour the one best complementing your setup.
   
  Overall, for my system at the moment, the CV4015 makes all the difference and the power tube conditions it. If a similarly great to CV4015 resolving but lesser bright and a bit more bassy tube would come along, the game might change as it could complement the 6H30-EV.
   
  PS: If your DAC and headphones are fine with a brighter sound (especially to avoid sharp "s"-sounds), the 6H30-EV will give the best performance with the CV4015. I have also checked the CV4014 again, and it has just amazing treble and mids, but in my setup it does lack bass.


----------



## mordy

Thanks for your thoughtful review. I do not have the CV4015, but I have a pair of Mullard EF92 tubes which I think are very similar (or I may be wrong). The EF92 tubes sounded somewhat exaggerated in the treble and the bass in my system.
   
  I almost always listen through speakers and to my taste the combination Tungsol 6AJ5/gold grid 6N6P is the best so far. Again, the same tubes may sound different in different systems, and part of the fun of tube rolling is to find what you like the best.


----------



## Acapella11

Quote: 





mordy said:


> Thanks for your thoughtful review. I do not have the CV4015, but I have a pair of Mullard EF92 tubes which I think are very similar (or I may be wrong).


 
   
  Cheers. Reading back to what Dept_of_Alchemy wrote in the beginning, it sounds like one of his preferred setups was 6N6P-I with CV4015, which is what I am listening to as I am typing this. It is a very recommendable combination. However, as you indicated, it is not the single component but the whole system that should sound according to ones liking.
  Considering other nice tubes (GE JAN 5654W, Sylvania 5654W, Mullard M8100, Tung-Sol 6AJ5 etc.) - they are still great tubes but at the moment, I am locked in CV4015 mode =). I admit that the lesser power of the 6AJ5 may not be an issue with your stereo setup, but is likely to reduce the dynamics of the HE-500. They go better with a little more efficient headphones. Hence, the SQ is probably not fully reproduced. I just attached a pic of the CV4015 I am using at the moment.
   
  Very best


----------



## hallom

Hey John, do you know how to make a difference between them by looking?
   
Quote:


> Many Russian 6n6p tubes use copper posts for the grid wires which may look like gold wires but are steel alloy. The [size=small]Sovtek 6H30 [/size]tube that I was testing also uses steel alloy grid wires. See post #36


----------



## john57

Once you have the real gold wire tube you can learn to spot the differences using a LED flashlight at the right angle.


----------



## hallom

hmmm, thanks!


----------



## hallom

Quote: 





donluca said:


> I have them, but only the ones from the 80s (1987).
> I still have to try them because I want to finish the burn in process of my voskhods from the '73


 
   
   
  Hey donluca, can I ask your experience about the gold/platinum Voskhods vs the normal ones?


----------



## mordy

Dear A11,
   
  Have you been able to decipher the markings on your CV4015 tube? Manufacturing date, factory etc?


----------



## mordy

Hi Hallom,
   
  I do have both the regular and gold grid Voskhods. My impression was that the gold grid ones were a little more mellow and not as much forward sounding as the regular ones. Similar, but personally I preferred the gold grid ones.


----------



## Acapella11

Dear Mordy, the CV4015 label says: 000-4015, CV4015, KQDD/K, 80-49.
  80-49 is probably week 49 from 1980.
   
  Coming from EF92-tubes to EF91 - has anyone else tried CV4014 tubes and has particular EF92 or EF91 favourites?
   
  I just tried the CV4014. For all the ones fancy trying non-EF95 combinations: CV1404 (EF91) is a higher gain tube and very nice in terms of resolution and treble agility. Hence, 6N6P-IR is a good calming complement, although 6N6P and 6N6P-I are fine too (depending on system matching, personal preference etc.).


----------



## Mp0wer

Are these the large shield military spec mullards 

http://www.ebay.com/itm/370602557099?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649


----------



## Nirvana Woman

Hello all, question here.
   
  Does someone have any experience with M8100 tubes made by RTC in France?
   
  I'm looking at an interesting auction but the seller, while very responsive, would understandably not like to make any comments on their quality in comparison to the regular military Mullard ones.
   
  So, anyone?


----------



## Oskari

Quote: 





nirvana woman said:


> Does someone have any experience with M8100 tubes made by RTC in France?


 
   
  M8100 was a Mullard type. By definition a true M8100 could only have come from a Mullard factory.
   
  Are you asking about an equivalent tube made by RTC or about an RTC-labelled tube made by Mullard?


----------



## Nirvana Woman

Quote: 





oskari said:


> M8100 was a Mullard type. By definition a true M8100 could only have come from a Mullard factory.
> 
> Are you asking about an equivalent tube made by RTC or about an RTC-labelled tube made by Mullard?


 
  I guess it would be a m8100 equivalent made by RTC. As I understand it, both are part of Philips group. Mullard made M8100 in UK and RTC made equivalents in France. I just don't know if they are truly an equivalent in the sense of them sounding alike.


----------



## Oskari

Unlikely to sound exactly the same, but I don't know this as a fact. There is something about RTCs on pages 131 and 134 in the Little Dot MKIII Tube Rolling thread.


----------



## Nirvana Woman

Quote: 





oskari said:


> Unlikely to sound exactly the same, but I don't know this as a fact. There is something about RTCs on pages 131 and 134 in the Little Dot MKIII Tube Rolling thread.


 

 Thanks for the lead


----------



## Jefreywith1f

Hi all,
   
  I bought a used MKIII about a month ago.  I love it.  Right now using Sylvania JAN 5654's which sound great.  I'm actually using Panasonic HTF 600-S headphones which is why I'm chiming in. They sound really fantastic with this amp.  I originally had the gain switches set to 4, I believe. But now I have both switches to I believe it's 'on' which would be 3.  The sound stage narrowed a bit for some reason, but the clarity may have increased.  Anyway, I A/B'ed these headphones on this amp against Grado's SR60i's and the Panasonic had so much more depth it was unreal. The top end of the Grado's sounded harsh.  Anyhow, not a headphone review.  Meant to just say how fantastic this amp sounds.
   
  I'm also using this amp as a preamp with playing vinyl.  The new Beatles remastered vinyl sounds unreal and with this amp it's truly amazing.  For anyone lurking (as I once did) that wants to know how to use this with a turntable it's simply Turntable to phono stage to Little Dot to receiver input.  I get absolutely no hum or other issues with this chain.  I'm using a 5.1 surround Yamaha receiver and since it doesn't have a Phono input I'm just using a AUX input (hence the phono stage in my chain before the Little Dot entered the situation; but the Little Dot needs that phono stage as well).
   
  I have a set of 6J1P-EV's coming this week hopefully. Excited to try those out with the Little Dot!  I bought from this exact auction:
   
  http://www.ebay.com/itm/130436695928?_trksid=p5197.c0.m619


----------



## Nirvana Woman

Quote: 





jefreywith1f said:


> Hi all,
> 
> I bought a used MKIII about a month ago.  I love it.  Right now using Sylvania JAN 5654's which sound great.  I'm actually using Panasonic HTF 600-S headphones which is why I'm chiming in. They sound really fantastic with this amp.  I originally had the gain switches set to 4, I believe. But now I have both switches to I believe it's 'on' which would be 3.  The sound stage narrowed a bit for some reason, but the clarity may have increased.  Anyway, I A/B'ed these headphones on this amp against Grado's SR60i's and the Panasonic had so much more depth it was unreal. The top end of the Grado's sounded harsh.  Anyhow, not a headphone review.  Meant to just say how fantastic this amp sounds.
> 
> ...


 
   
  Very nice price on those voshkods!  Perhaps you should order multiple sets, seeing as how you're going to be paying four times the price of one set for shipping alone 
   
  edit: - nevermind, you've already ordered


----------



## Jefreywith1f

Quote: 





nirvana woman said:


> Very nice price on those voshkods!  Perhaps you should order multiple sets, seeing as how you're going to be paying four times the price of one set for shipping alone
> 
> edit: - nevermind, you've already ordered


 
   
  I get that you're probably half kidding there. But really, who cares what the shipping costs are?  It's the combined total that matters.  $15 for a set is a good price for these.  I don't need 10 sets of the same tubes laying around my house, so buying bulk is of no interest and pointless for me.


----------



## dxanex

I just received my Voskhod EF95 tubes in a few days ago from this seller:
   
  http://www.ebay.com/itm/140882555908?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649
   
  I didn't have a chance to post my impressions yet. It's a good tube, very well constructed as the OP stated, but to my ears I still enjoy the RCA 5 Stars a bit more. They are slightly less forward and in-your-face as the Voskhods, and the treble on the Voskhods are just a bit to bright for my taste. Maybe they need to burn in some?
   
  I've tried more than half of the EF95 tubes reviewed here (still waiting to try the Mullards and Tung-Sols though) and the RCA 5 Stars are still my personal favorite thus far. The soundstage is fantastic and the music seems much more holographic and transparent to my ears.


----------



## Jefreywith1f

Quote: 





dxanex said:


> I just received my Voskhod EF95 tubes in a few days ago from this seller:
> 
> http://www.ebay.com/itm/140882555908?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649
> 
> ...


 
  Others here claim quite a bit of burn-in time on the Voskhods (if I recall, up to 120 hours claimed by some).  I noticed that auction as well, but went with the gold grid tubes since those have been talked about here.  Not convinced it would make any difference gold grid or not.  Still waiting for them to arrive. Must be hung up at customs since they're coming from Moscow.


----------



## john57

It usually take me about a month to receive tubes from Russia. Just hang in there!


----------



## dxanex

Quote: 





jefreywith1f said:


> Others here claim quite a bit of burn-in time on the Voskhods (if I recall, up to 120 hours claimed by some).  I noticed that auction as well, but went with the gold grid tubes since those have been talked about here.  Not convinced it would make any difference gold grid or not.  Still waiting for them to arrive. Must be hung up at customs since they're coming from Moscow.


 
   
  Who has 120 hours for something like that?! 
	

	
	
		
		

		
			





 I'm an instant gratification kind of guy, anyway, so I'll stick with the GE 5 Stars and call it a day. 
	

	
	
		
		

		
		
	


	



   
  In the mean time, if anyone wants to try out the Voskhod EF95 and doesn't want to wait a month, I'll let my matched pair go for 14 bucks, free shipping. You'll get them in about 3 days within USA. Check my seller feedback and PM me...
   
   
   
   
  EDIT: I just realized I kept calling them RCA 5 Stars in the above post...I mean to say GE 5 Stars! Too many tubes!


----------



## Jefreywith1f

Quote: 





dxanex said:


> Who has 120 hours for something like that?!
> 
> 
> 
> ...


 
  I hear you there.  I will try to burn them in by letting my ipod run overnight while I'm sleeping.  In other words, 6-7 hours is about what I get a night. I'm in no hurry to burn them in.  Doesn't mean I'm not trying these tubes out the second they hit my doorstep.  Tracking shows in the States now. So, a few more days of patience.


----------



## Mp0wer

I agree the GE 5 stars sound amazing and I prefer them over the Voskhod EF95.

I just ordered a pair of GE JAN-5654W, which are supposed to be better than the 5 stars...will see :rolleyes:


----------



## dxanex

Quote: 





mp0wer said:


> I agree the GE 5 stars sound amazing and I prefer them over the Voskhod EF95.
> I just ordered a pair of GE JAN-5654W, which are supposed to be better than the 5 stars...will see


 
   
  lol, I have those too.....and still, GE 5 Stars all the way for me. You may like the JAN's better, though. I will say the treble has more sparkle than the GE 5 Stars, and guitars and female vocals especially sound really nice on the JAN's. But the 5 Stars definitely edge them out in the soundstage department. And they are just slightly warmer and cleaner sounding (to me). I do like the JAN's when listening to rock and some electronic, but there's still something about those 5 Stars that keep me coming back! 
	

	
	
		
		

		
		
	


	



   
  Let me know your impressions, I'm interested to hear what a fellow 5 Star lover thinks...


----------



## Acapella11

To my ears the the treble of the Voskhods had become milder during the burn-in process. Actually, I favoured them in the beginning a bit over the sound after 100 hours. After all, it is a fine sound coming from these tubes. I haven't tried the GE 5 Star, maybe I can be tempted... 
   
  If you favour spatial representation over forward sound, I can recommend the 6N6P-IR power tube. The differences may sound subtle first, but once you get into it, you can appreciate the black background, instrument separation and stage size opened up by the relatively warm 6N6P-IR.


----------



## dxanex

100 hours? 120 hours?....again I just gotta say...
   

   
  But if the sound is perfect for you, then cheers to that!


----------



## Cakensaur

Just to ask, as I'm new to this whole tube rolling thing, what do you mean by "jumpers off"
  I'd rather be safe than sorry.
   
  Thanks


----------



## Acapella11

dxanex: I  actually let them burn in without me being there at all times . This way the blocks became longer making it also easier to count the hours.
   
  Mordy: I actually went back to the JAN-CTL-6AJ5 (who could forget them 
	

	
	
		
		

		
		
	


	




 ) and lined them up with 6H30-EV. The 6AJ5 are put better into picture now. Dynamics (PRaT) is more lively and the 6AJ5 contribute the mid-sweetness and greater stage. Great combo and surely my favourite power tube for these. If you now ask whether I would like this over 6N6P-IR + CV4015 
	

	
	
		
		

		
		
	


	




, then I wouldn't know yet but it surely is a good alternative at least. Personally, changing the jumpers is not one of my favourite things, it always takes me a few minutes to get them out and back on. So, I might get happily stuck with the 6AJ5 again for a bit.
   
  Cakensaur: There are two pairs of jumpers on the LD MKIII, the black ones, which are switched between the default setting (not bridged) for EF95 family tubes (M8100, Voskhod 6J1P-EV, JAN5654, 6AJ5 ...) and bridged for the EF91 and EF92 family tubes (see thread start post). Then, there are little dip switches allowing to change between on and off in order to adjust the gain (loudness) of the amp. See also the LD MKIII manual.


----------



## BillyAppleSauce

Are the oils on your hands bad for tubes?


----------



## dxanex

Quote: 





acapella11 said:


> dxanex: I  actually let them burn in without me being there at all times . This way the blocks became longer making it also easier to count the hours.


 
  I know, I just really wanted an excuse to use that animated GIF I found. But I still don't like to leave my equipment running for that long of a period of time. I'm sure it's ok, I'm just weird like that...


----------



## Nirvana Woman

Quote: 





billyapplesauce said:


> Are the oils on your hands bad for tubes?


 
  I remember wondering about this and as I recall it should be no problem at all, as long as you take the least amount of care.


----------



## mordy

In the LD MKIII manual it says not to leave it on more than 8 hours at a time. It seems that this is a precaution that the unit should not overheat since heat is an enemy of electronics.
   
  I have my unit placed on three one inch aluminum cones (leftover from 80's Hi-Fi) which allows for plenty of cooling via convection. I use a very scientific method to check how hot the unit runs by touching the metal casing.The heat of the metal casing varies with room temperature and with the type of tubes you use - I remember the case getting real hot with some EF92 type tubes I was trying, but usually it is just warm, or almost cool when the A/C is on in the summer.(Just don't touch the tubes, especially not the power tubes since you could burn yourself.) BTW, I don't think that the natural oils on my fingers make any difference; just don't touch automotive halogen bulbs with your fingers directly since they get really hot and can break from this.
   
  Some people rig up a fan to blow on the unit (good idea if you live in the desert or near the equator).
   
  I asked David Zse Zse of Little Dot how long I can expect my beloved amp to last. He answered that it should last as long as regular consumer electronics - 20 years or so.
   
  In order to break in the Voskhods, which changed into a more mellow character after about 120 hours, I simply put on my CD player or iTunes program on continuous play with my headphones and wrote down how many hours my unit was on until I chalked up the required amount of hours. That said, many tubes I tried seemed to stabilize at 30 - 50 hours, but these Russkies need much more.
   
  Disclaimer, and just to be on the safe side: You are on your own if you run your amp for 5-6 days straight, but I did not have any problems.


----------



## Strangelove424

Quote: 





alexroma said:


> Voskhod 6J1P-EV tubes are simply FANTASTIC with all Senn's HD5** series..
> 
> For BeyerDynamic, however, Mullard M8100/CV4010  perform better, softer and less fatigue on already emphasized "beyer" highs. Bass on my CV4010 is also, a little rolled off, but in a manner there is almost nothing to complain about.
> 
> I generally find russian tubes like V-shaped M8100 clone, with extra 3 db on both, bass and treble regions. But than again, with most Sennheiser phones, Voskhod sing great.


 
   
   
  As a DT880/600 owner I keep coming back to this post in my head, because I think it’s fairly true. I’ve rolled Voskhods and Mullards back and forth over and over and my personal conclusion is that the Mullards are magic for the DT880s. The Voskhods are great, they have SS-like detail and airiness but still impart thicker mids and a slight bloom compared to a SS amp, and for HD6XX owners I can imagine you guys are liking it a ton, but for the Beyers I found the sacrifice in airiness and treble (which the DT880 has in spades, perhaps even in excess) was worth it to gain what I think is a huge improvement in tone, richness, and depth. The mids seem to really shine now, and yet still retain their transparency and three-dimensionality. And it’s also quite nice that the hot treble and sibilance with the Mullard M8100s is gone, banished. What’s left over is a thoroughly detailed headphone with a sweeeet balance between tone and dynamics, a balance I can’t quite achieve with the Voskhods. Put on something like Andrea Bocelli, Chris Botti, or Chet Baker and you will be bathed in thick creamy notes, but the sizzle of the top hats in Michael Jackson’s thriller will still make you jump. I am very happy with this combo. That being said, if I was on a fast rock’n’roll binge, keeping it on Billy Idol or Blondie, the Voskhods seem to do a better job at that stuff, and I still find myself swapping them back and forth often.


----------



## MIKELAP

Quote: 





billyapplesauce said:


> Are the oils on your hands bad for tubes?


 
  thats what i use good grip doesnt slip


----------



## Nirvana Woman

Quote: 





strangelove424 said:


> As a DT880/600 owner I keep coming back to this post in my head, because I think it’s fairly true. I’ve rolled Voskhods and Mullards back and forth over and over and my personal conclusion is that the Mullards are magic for the DT880s. The Voskhods are great, they have SS-like detail and airiness but still impart thicker mids and a slight bloom compared to a SS amp, and for HD6XX owners I can imagine you guys are liking it a ton, but for the Beyers I found the sacrifice in airiness and treble (which the DT880 has in spades, perhaps even in excess) was worth it to gain what I think is a huge improvement in tone, richness, and depth. The mids seem to really shine now, and yet still retain their transparency and three-dimensionality. And it’s also quite nice that the hot treble and sibilance with the Mullard M8100s is gone, banished. What’s left over is a thoroughly detailed headphone with a sweeeet balance between tone and dynamics, a balance I can’t quite achieve with the Voskhods. Put on something like Andrea Bocelli, Chris Botti, or Chet Baker and you will be bathed in thick creamy notes, but the sizzle of the top hats in Michael Jackson’s thriller will still make you jump. I am very happy with this combo. That being said, if I was on a fast rock’n’roll binge, keeping it on Billy Idol or Blondie, the Voskhods seem to do a better job at that stuff, and I still find myself swapping them back and forth often.


 

 Just wanted to say comparisons and well written opinions like this are very helpful, thanks


----------



## Strangelove424

Quote: 





nirvana woman said:


> Just wanted to say comparisons and well written opinions like this are very helpful, thanks


 
   
  Thank you. I've been mining information from this thread like a leech. Anything I can do to contribute back to it is my pleasure.


----------



## Nirvana Woman

Quote: 





strangelove424 said:


> Thank you. I've been mining information from this thread like a leech. Anything I can do to contribute back to it is my pleasure.


 

 I see .
   
  The thing is that I've found myself kind of clueless on this Mullard 8100 vs Voshkod thing.
   
  The Mullards are said to offer a very pleasing and warm sound, which seems like something I would want as I typically listen for hours on end.
   
  I am kind of afraid the Voshkods would still be too harsh with my HD650. I'm running stock tubes (GE5654) and don't find the amp harsh sounding at all. I just don't want the Voshkods to throw harshness into the equasion, so to speak, and don't know how much is true about breakin.
   
  So I'm feeling that the Mullards are probably the safest best on a decent upgrade from the stock tubes, but I am unsure .


----------



## dxanex

Quote: 





nirvana woman said:


> I see .
> 
> The thing is that I've found myself kind of clueless on this Mullard 8100 vs Voshkod thing.
> 
> ...


 
   
  I have the Voshkods and I don't care for them on my HD650's, and with my K550's forget it. Painful highs to my ears. People say that they settle down after a hundred hours or so, but I'm not going to spend that much time on something like that if I'm not a fan out the gate. That's just me. First impressions are everything.
   
  I have some Tung-Sols coming in the mail now, which are said to be a slightly less warm version of the Mullard 8100. I haven't tried the Mullards yet, but that all depends on how the Tung-Sols sound to me. I'll let you know my impressions when I get them.
   
  If you want to try the Voshkods PM me. I have some I'll let go for a good price if you live in the USA.


----------



## Nirvana Woman

Quote: 





dxanex said:


> I have the Voskhods and I don't care for them on my HD650's and with my K702's forget it. Painful highs to my ears. People say that they settle down after a hundred hours or so, but I'm not going to spend that much time on something like that if I'm not a fan out the gate. That's just me. First impressions are everything.
> 
> I have some Tung-Sols coming in the mail now, which are said to be a slightly less warm version of the Mullard 8100. I haven't tried the Mullards yet, but that all depends on how the Tung-Sols sound to me. I'll let you know my impressions when I get them.
> 
> If you want to try the Voskhods PM me. I have some I'll let go for a good price if you live in the USA.


 

 Ah cool  I'll be awaiting your impressions on the Tung-Sols then.
   
  By the way, we already pm'ed about those Voshkods a while ago  But it's all good ofcourse


----------



## Strangelove424

Quote: 





nirvana woman said:


> I am kind of afraid the Voshkods would still be too harsh with my HD650. I'm running stock tubes (GE5654) and don't find the amp harsh sounding at all. I just don't want the Voshkods to throw harshness into the equasion, so to speak, and don't know how much is true about breakin.
> 
> So I'm feeling that the Mullards are probably the safest best on a decent upgrade from the stock tubes, but I am unsure .


 
   
  Mullards are certainly an upgrade in every way, shape and form. You will hear more details, bigger sound stage, more dimension, better bass, silkier mids, I could really go on and on about how much better they are than stock. Maybe try out the Mullards, and if you want more detail or treble energy, then roll in Voskhods. They're certainly both great tubes, and it probably wouldn't hurt to try them both out. If you can get a good deal from dxanex, I say go for it too!


----------



## Nirvana Woman

Quote: 





strangelove424 said:


> Mullards are certainly an upgrade in every way, shape and form. You will hear more details, bigger sound stage, more dimension, better bass, silkier mids, I could really go on and on about how much better they are than stock. Maybe try out the Mullards, and if you want more detail or treble energy, then roll in Voskhods. They're certainly both great tubes, and it probably wouldn't hurt to try them both out. If you can get a good deal from dxanex, I say go for it too!


 

 Hehe, thanks for that ).
   
  Yeah I think you've confirmed my gut instinct which tells me to first try the Mullard 8100's. They're a little more expensive, but I just feel like it's going to be the right choice . Cheers.


----------



## dxanex

Quote: 





nirvana woman said:


> Ah cool  I'll be awaiting your impressions on the Tung-Sols then.
> 
> By the way, we already pm'ed about those Voshkods a while ago  But it's all good ofcourse


 
  Oh yes, sorry. Of course I remember now you are in the Netherlands...I'm selling a lot of stuff off, so a lot of PM's lately!


----------



## Nirvana Woman

Quote: 





dxanex said:


> Oh yes, sorry. Of course I remember now you are in the Netherlands...I'm selling a lot of stuff off, so a lot of PM's lately!


 

 That's right xD
   
  Glad to hear you're doing good business, anyway .


----------



## mordy

Hi dxanex,
   
  Just want to point out that I personally do not prefer the Voskhods - just like you say, they are too bright for me. However, they get more mellow by time.
   
  Some people like the Voskhods better than anything else. My conclusion is that tubes sound different through different equipment, and you have to find out what suits you best. Somebody on this site started to call me names when I voiced my opinion about the Voskhods. There is a remedy for this: You can block comments from people that you do not want to hear from.
   
  What makes tube rolling so much fun is the trial and error process in finding out how you like a certain set of tubes. There is no one tube that's the best for everybody, but it is safe to say that by choosing from a limited number of over achievers you will find what you like. These tubes are identified on this site, and people's recommendations can be very helpful.
   
  I assume that people on this site are honestly reporting what they hear; at least I am trying to do that. And by running two sets of Voskhods for over 120 hours each, I can state that they do change after that lengthy burn in. The Voskhods were made for Russian military duty and for long life. Perhaps their ruggedness has something to do with the long break in period.


----------



## Acapella11

Sound quality preference is mostly not a straight answer from my point of view. Perception of musical detail varies dependent on the form of the day as well.
   
  Through everything that people state here you probably get a good idea of what is a good tube and I found this thread really great. Now, source and headphone have a huge impact of how the music comes across, so everything needs to be taken with a grain of salt.
   
  Personally, I am not a Voskhod fan. Although highly rated, their mids are not exactly my favourite. On the other hand, I must say, they - are - great tubes and I am sure it is a good idea to buy a pair, they may be in your system just what you want. I preferred the 1975 ones from Yen over the 1982 ones. The bass is better on the 1975 Voskhods.
   
  For the M8100, I have got two pairs, and I believe that one - is - better than the other one. The M8100 labelled one has better imaging and an improved bass compared to the non-Mullard labelled one (CV4010). So, if you have an M8100/CV4010, it can still be interesting with a different second pair.
   
  The Sylvania JAN5654W are also great tubes, a bit warmer / darker than GE JAN 5654W.
   
  The Tung-Sol 6AJ5 are really good with great mids and spatial resolution, it is sure worth getting them as well. Mine are from 1945 and I love them, only they are a bit lesser in power.
   
  My hit list finishes with CV4015 tubes paired with 6N6P-IR. Great focus,resolution and space, yet warm enough for me.
   
  I recently had a listen to the Sennheiser HD650 and I noticed that it scaled well with better tubes although still keeping the relaxed representation. It took me a little getting used to it and I liked it after a while although it wouldn't be my favourite. It seems also forgiving in terms of treble and brightness, so if any tube is a bit brighter (maybe Voskhod or GE JAN 5454W, CV 4015, 6H30-EV power tubes), the HD650 will take it relaxed.
   
  Enjoy the tube rolling, really. You learn a lot about the width of your personal preference.
   
  Very best


----------



## dxanex

Quote: 





acapella11 said:


> Sound quality preference is mostly not a straight answer from my point of view. Perception of musical detail varies dependent on the form of the day as well.
> 
> Through everything that people state here you probably get a good idea of what is a good tube and I found this thread really great. Now, source and headphone have a huge impact of how the music comes across, so everything needs to be taken with a grain of salt.
> 
> ...


 

 Nicely said! Also good impressions of your tube rolling journey. I've actually been listening to the GE JANs more lately with my HD650's, with rock music especially. I really can hear the infamous HD650 veil being lifted completely from vocals and the bass is also a bit tighter and more controlled than on my go-to tube, the GE 5 Stars.
   
  I still prefer the 5 Stars on my K550s though, the soundstage is just awesome and the mids are silky smooth. But now I prefer the GE JAN tubes with the HD650. So I agree completely that the HD650 scales very well with tube rolling. I don't know if I'd call it a night-and-day difference, but it is very noticeable, especially with vocals. 
   
  Also, thanks for the heads up on the Mullards. I plan on picking up a set soon and I'll look for the M8100 label version. I've also got some Tung-Sols coming in the mail, so I'm looking forward to trying them out soon as well.


----------



## mordy

Enjoyed reading about the various tube rolling adventures and choices of tubes. Regarding the Mullard tubes the CV4010 and M8100 are supposed to be very similar - the main thing is to get tubes made in the UK in the Mitcham factory, which was supposed to be one of the most advanced of its time.
   
  There is another Mullard tube which is very similar and sounds great: EF95/CV850.
   
  Lastly, to add some more challenges to the tube rolling, I never paid more than $8/tube (including shipping), and usually less than half of that. The trick is to check Ebay often and to communicate with the seller. You want to deal with the guy that does it as a hobby and is selling off his grandfather's stock or stuff he got at an estate sale; not the people who do it as a business and charge you $89.99 each for the same 6AJ5 tube that I just picked up for less than $6/pair.


----------



## Oskari

Quote: 





mordy said:


> Regarding the Mullard tubes the CV4010 and M8100 are supposed to be very similar


 
   
  They are the same!
   
  "The CV4010 is the UK Government code for the commercial M8100 which in turn is Mullard's special quality version of the EF95." (CV4010 @ The National Valve Museum)
   
  There are, of course, different vintages of these.
   
  P.S. Please use _Vos*kh*od, everybody_. Voshkod is nonsense.


----------



## zedmeco

Hi, my update so far. Since starting with the little dot mk iii, I have burned in the stock tubes for a month and the sound developed nicely, giving me a fantastic aural experience with my HD650's, which were burning in at the same time. the first new tubes to go in were the novosibirsk 6H6P-I power tubes, I wanted to get these burned in and keep the original as back up, with these went in the  voskhod 6ZH1P-EV, these little babies sounded amazing right away, giving crisp highs with plenty of detail around the midrange and a nice warm bottom. this set got a month and the the sound developed again, smoother and packing much more punch in the lower register. time for the mullard M8100/CV4010, immediately, I found the sound warmer still, plenty of detail, none of the background noise some people have mentioned at higher volumes. I still have some time to spend with these tubes but next up will be the sylvania JHS 6AK5-5654, and I am waiting for the GE 5 star 6AK5W and voskhod 62H1P-EV with gold/platinum grids to arrive. I must say, finding this forum and trolling the threads has proved costly, but I am so happy with the set up, and I am sure I deserve it really. z


----------



## Strangelove424

Quote:
   


oskari said:


> "The CV4010 is the UK Government code for the commercial M8100 which in turn is Mullard's special quality version of the EF95." (CV4010 @ The National Valve Museum)


 
   
   
  "The National Valve Museum"....
   
  .... this is one of those times in life that I wish I was a master cat burglar.


----------



## mordy

OK folks, time to take a trip to visit the Mullard tube factory. Here is a great movie showing how a vacuum tube is being made in the Mullard Blackburn factory that employed over 8000 people in it's heyday.
   
  http://www.youtube.com/watch?v=GDvF89Bh27Y


----------



## MIKELAP

Quote: 





mordy said:


> OK folks, time to take a trip to visit the Mullard tube factory. Here is a great movie showing how a vacuum tube is being made in the Mullard Blackburn factory that employed over 8000 people in it's heyday.
> 
> http://www.youtube.com/watch?v=GDvF89Bh27Y


 
  Very interesting thanks mordy.


----------



## Strangelove424

Quote: 





mikelap said:


> Very interesting thanks mordy.


 
  +1   Anyone have any material on Voskhod? On a pure workmanship note the Voskhods are a thing of beauty. The internals and valve reek of quality. All I know is that they were designed for the Voskhod rocket (which I believe hosted the first space walk) and that it was a state-managed but privately owned communist factory.


----------



## britt2001b

Quote: 





mordy said:


> OK folks, time to take a trip to visit the Mullard tube factory. Here is a great movie showing how a vacuum tube is being made in the Mullard Blackburn factory that employed over 8000 people in it's heyday.
> 
> http://www.youtube.com/watch?v=GDvF89Bh27Y


 
   
  Thanks for posting this Mordy. I enjoyed it immensely! It was a nice, nostalgic trip back in time.


----------



## eljustinoid

I've just gotten a pair of Westinghouse 6AK5 (says that on the box, no idea if they are the same as your 5654 or not) just because I like the classic US "military industrial complex" brands of that era. Nothing recessed about the vocals that I can hear. and if anything I'd say they have a very punchy upfront sound which could maybe use a bit more bass - but I would say these have UPFRONT vocals in a big way.
   
  I agree with most of the consensus on Little Dot tubes (love them Russians!), but my Westinghouse experience is very different. Did I say upfront vocals? Nice sound and quite different.


----------



## mordy

Thanks for your kind words about the Mullard movie..
   
  The first thing that struck me is the complexity of the manufacturing. The other thing that I find very striking is the almost complete absence of protective gear and clothing for the workers. Only the workers working with very corrosive acids are wearing thick rubber gloves, but otherwise everything seems to be done with the bare hands, be it welding or dealing with chemicals. Indeed, a different era.
  On the other hand, there seemed to be a lot of effort put into automatizing the process of making vacuum tubes.
   
  Just for fun, take a look at the manufacturing of micro chips; there are many similarities, not to mention salami slicers and train wrecks...
   
  http://www.youtube.com/watch?v=aWVywhzuHnQ


----------



## Acapella11

Quote: 





mordy said:


> OK folks, time to take a trip to visit the Mullard tube factory. Here is a great movie showing how a vacuum tube is being made in the Mullard Blackburn factory that employed over 8000 people in it's heyday.
> 
> http://www.youtube.com/watch?v=GDvF89Bh27Y


 

 Thanks for sharing this. The film is quite educative and it is a nice to see the fabrication in the old days.


----------



## dxanex

Quote: 





acapella11 said:


> Thanks for sharing this. The film is quite educative and it is a nice to see the fabrication in the old days.


 

 Interesting piece of history. Reminded me of this segment I saw on "How it's Made". They showed a company in Czech Republic that makes modern audiophile tubes. They are gorgeous...really look like works of art. I found the video if anyone is interested...
   





   
  edit: won't allow embedding- here's the link: http://www.youtube.com/watch?v=jNVZ8Pg3poo&feature=player_embedded


----------



## MIKELAP

Quote: 





dxanex said:


> Interesting piece of history. Reminded me of this segment I saw on "How it's Made". They showed a company in Czech Republic that makes modern audiophile tubes. They are gorgeous...really look like works of art. I found the video if anyone is interested...
> 
> 
> 
> ...


 
  Nice vid dxanex those tubes are so nice


----------



## Acapella11

Quote: 





dxanex said:


> Interesting piece of history. Reminded me of this segment I saw on "How it's Made". They showed a company in Czech Republic that makes modern audiophile tubes. They are gorgeous...really look like works of art. I found the video if anyone is interested...
> 
> edit: won't allow embedding- here's the link: http://www.youtube.com/watch?v=jNVZ8Pg3poo&feature=player_embedded


 
   
  Beautiful tubes here and nice to see the skillful production. These KR T-1610 are just massive. I would like to hear an amp with those big boys. Just checked , a matched pair is $2499, wow. We are developing this thread into a educative thread for tube manufacturing and I think this is good info for everyone interested in tubes.
   
  Just on a side note, I compared the combination Tung-Sol JAN-CTL-6AJ5 (1945) / Sovtek 6H30-EV (11/2011) with CV4015 (49-1980) / 6N6P-IR (Old Novosibirsk08/1974). The Tung-Sols sound sweeter overall, milder and yet resolving. The treble extends nice without being harsh at all. They do sound quite spacious. The bass is satisfying but not overly much. In contrast, the CV4015 sound a harder, more neutral. Guitar strings have a "hard vibration" on it, which I like. Imaging is clearer, bass is fuller. Treble is clean and revealing, which can be great or sometimes not, depending on recording quality. This may give you a better idea and you can fit the the tubes according to your preferences.
   
  In my ears the combination of CV4015 and 6N6P-IR is the favourite, since it covers a wide and deep stage, good imaging, authority, great treble and good bass extension, in summary a lot of sound information and dynamics.


----------



## dxanex

Quote: 





acapella11 said:


> Beautiful tubes here and nice to see the skillful production. These KR T-1610 are just massive. I would like to hear an amp with those big boys. Just checked , a matched pair is $2499, wow. We are developing this thread into a educative thread for tube manufacturing and I think this is good info for everyone interested in tubes.
> 
> Just on a side note, I compared the combination Tung-Sol JAN-CTL-6AJ5 (1945) / Sovtek 6H30-EV (11/2011) with CV4015 (49-1980) / 6N6P-IR (Old Novosibirsk08/1974). The Tung-Sols sound sweeter overall, milder and yet resolving. The treble extends nice without being harsh at all. They do sound quite spacious. The bass is satisfying but not overly much. In contrast, the CV4015 sound a harder, more neutral. Guitar strings have a "hard vibration" on it, which I like. Imaging is clearer, bass is fuller. Treble is clean and revealing, which can be great or sometimes not, depending on recording quality. This may give you a better idea and you can fit the the tubes according to your preferences.


 
  That's encouraging news! I'm still waiting on my Tung-Sol's to get here and I'm really itching to try them out. The guy sending them forgot to mail them out and finally mailed them over a week after I paid! Nice thing is, he gave me a FULL refund for the error, and I didn't even ask...nice Christmas present for me, free 1950's era Tung-Sol's!


----------



## mordy

Thanks for a beautiful video - gives new meaning to hand made.


----------



## Nirvana Woman

Quote: 





dxanex said:


> That's encouraging news! I'm still waiting on my Tung-Sol's to get here and I'm really itching to try them out. The guy sending them forgot to mail them out and finally mailed them over a week after I paid! Nice thing is, he gave me a FULL refund for the error, and I didn't even ask...nice Christmas present for me, free 1950's era Tung-Sol's!


 

 That's pretty cool  Hopefully you'll have them soon. My 8100's were shipped earlier last week, might arrive this week or the one after .


----------



## Cakensaur

Waiting on voshkovs at the moment. cannot wait


----------



## dxanex

Well, I got my Tung-Sol 5654W's in and I have spent some time with them last night and this morning. I have to turn the volume knob on my Darkvoice amp up slightly more, but these things are 60-some years old, so that's not surprising. But for 60-year-old tubes, all I can say is WOW. I _think_ they are my new favorite tube!
   
  Someone mentioned they are quite spacious. That's the very first thing I noticed....these things produce a huge and very 3D presentation, especially on the HD650, which can sometimes sound closed in. I was pretty floored, because I wasn't expecting such a big soundstage. I listened to a few tracks I'm quite familiar with, where the original mastering wasn't really the best. I was clearly picking out snare drums and high-hats that I hardly ever noticed in the past which before were just washed out in a wall of sound.
   
  The mid range is very resolved and just a bit more forward than my GE 5 Stars (my amp's previous reigning champ) but not nearly as forward as the Voskhods. Laid back, but still very engaging and impressively detailed. I still can't believe how nice they sound considering they are the oldest tubes I've ever owned. Now I know why everyone talks about Tung-Sol tubes. Very sweet tubes, indeed.
   
  Edit: At first the soundstage was so surprising that it almost sounded unnatural. But now that I've had time to really get used to it, I'm convinced I've found the perfect tubes for my amp. The HD650 now sounds much closer to the HD800 (
	

	
	
		
		

		
		
	


	




) in terms of soundstage (not brightness or resolution), where instruments are clearly being heard inches behind my head and above. Very 360 presentation. I highly recommend the Tung-Sol 5654w to lovers of large soundstage.


----------



## Nirvana Woman

Glad you are enjoying the Tung-Sols. Quite an impressive writeup too .
   
  I was trying to looking for them but sadly they seem rather hard to find here in Europe. So if you have any good leads, I'd love it if you let me know.
   
  Got my M8100's today and I'm really happy with them. The first thing I noticed is that they sound less closed in than the stock tubes which I agree can very occasionally sound a little claustrophobic. I never felt anything wrong with the GE5654's and actually kind of feared an unwelcomed change with the new tubes but this is definitely appreciable. Gonna play some music for the rest of the day and enjoy them - with the HD650's ofcourse, as always .


----------



## mab1376

Quote: 





dxanex said:


> Well, I got my Tung-Sol 5654W's in and I have spent some time with them last night and this morning. I have to turn the volume knob on my Darkvoice amp up slightly more, but these things are 60-some years old, so that's not surprising. But for 60-year-old tubes, all I can say is WOW. I _think_ they are my new favorite tube!
> 
> Someone mentioned they are quite spacious. That's the very first thing I noticed....these things produce a huge and very 3D presentation, especially on the HD650, which can sometimes sound closed in. I was pretty floored, because I wasn't expecting such a big soundstage. I listened to a few tracks I'm quite familiar with, where the original mastering wasn't really the best. I was clearly picking out snare drums and high-hats that I hardly ever noticed in the past which before were just washed out in a wall of sound.
> 
> ...


 
   
  Based on your write up they are probably very similar to the Raytheon 6AK5 tubes I bought from Maverick Audio.
   
  Did you get the Foil getter or D getter model?
   
  I was looking to get this model: http://www.ebay.com/itm/TUNG-SOL-JAN-6AK5-6AK5W-MIL-SPEC-MATCHED-SET-PAIR-5654-W-Amp-Audio-Vintage-Tube-/110986580853?pt=Vintage_Electronics_R2&hash=item19d750d375


----------



## dxanex

Quote: 





nirvana woman said:


> Glad you are enjoying the Tung-Sols. Quite an impressive writeup too .
> 
> I was trying to looking for them but sadly they seem rather hard to find here in Europe. So if you have any good leads, I'd love it if you let me know.
> 
> Got my M8100's today and I'm really happy with them. The first thing I noticed is that they sound less closed in than the stock tubes which I agree can very occasionally sound a little claustrophobic. I never felt anything wrong with the GE5654's and actually kind of feared an unwelcomed change with the new tubes but this is definitely appreciable. Gonna play some music for the rest of the day and enjoy them - with the HD650's ofcourse, as always .


 
  Thanks! I do what I can to give back, haha. I'm glad you are enjoying your Mullards...that's one I'm also wanting to try because people say it's like a warmer version of the Tung Sol. But the Mullards in the US are like the Tung Sols for you...harder to get here, and usually 2-3 times the price. But I am really happy with my sound, so I will do the right thing and just enjoy the music! 
	

	
	
		
		

		
		
	


	



   
  Quote: 





mab1376 said:


> Based on your write up they are probably very similar to the Raytheon 6AK5 tubes I bought from Maverick Audio.
> 
> Did you get the Foil getter or D getter model?
> 
> I was looking to get this model: http://www.ebay.com/itm/TUNG-SOL-JAN-6AK5-6AK5W-MIL-SPEC-MATCHED-SET-PAIR-5654-W-Amp-Audio-Vintage-Tube-/110986580853?pt=Vintage_Electronics_R2&hash=item19d750d375


 
  The one's in this auction do look very similar to mine, although mine look more worn on the labels. But I'm sorry, I'm actually not really sure if mine are Foil getter or D getter. How do I know for sure? They actually did come packaged in brand new Raytheon 6AK5 boxes, and I thought they messed up my order but they were Tung Sols inside!


----------



## mab1376

Quote: 





dxanex said:


> The one's in this auction do look very similar to mine, although mine look more worn on the labels. But I'm sorry, I'm actually not really sure if mine are Foil getter or D getter. How do I know for sure? They actually did come packaged in brand new Raytheon 6AK5 boxes, and I thought they messed up my order but they were Tung Sols inside!


 
   
  if you look under the silver coating on top you should see a Metal D for a D getter, never seen foil first hand so not sure, but the ones in this action are foil according to the info.


----------



## Acapella11

Dxanex, It is really good to see you love the tubes you bought  Enjoy.
   
  Nirvana woman, I did not bother with a matched pair and got my 1945 tubes from this ebay guy to Europe:
  http://www.ebay.com/itm/TUNG-SOL-JAN-6AJ5-TUBES-/400329930842?ssPageName=ADME:L:OU:GB:3160
  Worked like a treat.


----------



## dxanex

Quote: 





mab1376 said:


> if you look under the silver coating on top you should see a Metal D for a D getter, never seen foil first hand so not sure, but the ones in this action are foil according to the info.


 

 Hm, I looked under the silver coating, and everywhere else for that matter and I didn't see metal D anywhere. So I assume that means they must be the foil getter version?


----------



## mab1376

Probably, not sure if there's any other variants, I only know about those two models since they re the ones i see on eBay.


----------



## mordy

Here is a photo of a D shaped getter. I am not sure what a foil getter is, but an educated guess is that instead of being made out of wire, the getter is made out of thin folded metal strips.
  Some getters are round (O shape), some square or rectangular, and others look like the electric take off on a street car (bent), and yet others look like a little cup on a saucer (Voskhod). I have never seen any write up if one design is better than another or yields better sonic benefits..
  The silver coating is called getter flash. To me, one of the most intriguing designs was made by Tung Sol. These tubes have the getter flash on the side of the glass envelope with the getter being a half moon shape attached to the plate and facing the getter flash. Such tubes have a completely clear top, and even though they are the same size as others, it appears to me that they could have been made much more compact since the top third is empty.


----------



## MIKELAP

Quote: 





mordy said:


> Here is a photo of a D shaped getter. I am not sure what a foil getter is, but an educated guess is that instead of being made out of wire, the getter is made out of thin folded metal strips.
> Some getters are round (O shape), some square or rectangular, and others look like the electric take off on a street car (bent), and yet others look like a little cup on a saucer (Voskhod). I have never seen any write up if one design is better than another or yields better sonic benefits..
> The silver coating is called getter flash. To me, one of the most intriguing designs was made by Tung Sol. These tubes have the getter flash on the side of the glass envelope with the getter being a half moon shape attached to the plate and facing the getter flash. Such tubes have a completely clear top, and even though they are the same size as others, it appears to me that they could have been made much more compact since the top third is empty.


 

   
   this a picture of a d foil getter its like you say folded metal strips. this is was seller said in description of these tubes


----------



## dxanex

My mistake, I was looking for an actual "D" stamp not the shape of the getter. I believe mine is a D shape, though one of the wires looks like it is twisted and wrapped around, which I don't see in the other picture. This is the best pic I could get on my iPhone.


----------



## Acapella11

I got a similar shape getter, a square bent in the middle, looks kind of like a roof.
   
  I see the cat is also curious about the getter


----------



## dxanex

Quote: 





acapella11 said:


> I got a similar shape getter, a square bent in the middle, looks kind of like a roof.
> 
> I see the cat is also curious about the getter


 

 Haha, yeah, she is always getting in my business!


----------



## Mp0wer

Do getter wires affect sound?


----------



## mordy

Spoke to my retired friend who is an electronics engineer and started out in the tube era. He told me that the purpose of the getter is to
  provide the materials for the getter flash (the silver coating on top of the tube) which absorbs any left over oxygen in the tube in order to make for a good vacuum.
  According to him, once this is done in the manufacturing process, the getter has no function any more.
   
  Interesting.....
   
*The getter*
We want a good, hard vacuum inside a tube, or it will not work properly. And we want that vacuum to last as long as possible. Sometimes, very small leaks can appear in a tube envelope (often around the electrical connections in the bottom). Or, the tube may not have been fully "degassed" on the vacuum pump at the factory, so there may be some stray air inside. The "getter" is designed to remove some stray gas. 
The getter in most glass tubes is a small cup or holder, containing a bit of a metal that reacts with oxygen strongly and absorbs it. (In most modern glass tubes, the getter metal is barium, which oxidizes VERY easily when it is pure.) When the tube is pumped out and sealed, the last step in processing is to "fire" the getter, producing a "getter flash" inside the tube envelope. That is the silvery patch you see on the inside of a glass tube. It is a guarantee that the tube has good vacuum. If the seal on the tube fails, the getter flash will turn white (because it turns into barium oxide). 
There have been rumors that dark spots on getters indicate a tube which is used. This is NOT TRUE. Sometimes, the getter flash is not perfectly uniform, and a discolored or clear spot can occur. The tube is still good and will give full lifetime.


----------



## Acapella11

Interesting information Mordy and thanks to your friend. The information goes well together with your film, where the Barium transfer is shown from the getter, if I remember correctly. Actually, it is shown in both films but with KR, the getter is on the side.
  The getter is just nicely distinguishable between tubes for us but then anode, cathode and grid seem to play the big role in sound reproduction.


----------



## mab1376

It's usually the most distinguishable quality which is whats used for reference here.
   
  e.g. I wanted to hear the sound that was reviewed so i asked which he had since on eBay the only 2 variants saw other than date was the getter. Personally I didn't know it was useless after the manufacturing process, pretty interesting.
   
  Regardless, I bought some Tung Sol's form the link I posted and I'll see if my sound matches the review. The sound I'm looking for is pretty much the Raytheons I have with a little better bass impact.


----------



## Nirvana Woman

Mmm I've been listening with the M8100's for a week now.
   
  I can't say I like them. I find the treble decidely bad sounding; often unpleasant, sometimes harsh. Maybe not harsh in that they are fatiguing but they seem to just annoy me for some reason.
  Also the tubes seem to be too warm and almost muddy.
   
  I dare say I actually prefer the default GE tubes. I mean I can get used to the warmer sound but the treble with the mullards is a disaster IMO. It's getting to the point that I'm doubting my appreciation for the Little Dot at all to be honest, especially because I don't like the thought of order yet another pair of new tubes and going back to the stock tubes probably means missing out on the things I like about the m8100's (the more distanced sound stage and better bass response).
   
  Meh.


----------



## dxanex

Quote: 





nirvana woman said:


> Mmm I've been listening with the M8100's for a week now.
> 
> I can't say I like them. I find the treble decidely bad sounding; often unpleasant, sometimes harsh. Maybe not harsh in that they are fatiguing but they seem to just annoy me for some reason.
> Also the tubes seem to be too warm and almost muddy.
> ...


 

 Sorry to hear you don't like them. :/  Do they have the actual 8100/Mullard logo printed on them? I know there are different versions...just curious.


----------



## Nirvana Woman

Quote: 





dxanex said:


> Sorry to hear you don't like them. :/  Do they have the actual 8100/Mullard logo printed on them? I know there are different versions...just curious.


 

 KQDD CV4010
   
  I've tried my hand at messing with the little dot's gain settings a bit. Used to have them at gain 4. Now they're at 10. There definitely seems to be a change in that the sound seems to contain more of a 'hall' effect, so to speak. The bass is also much, much stronger.
  At least that´s my first impression. I want to say it´s also solved the weird treble issue, but I´m not sure about that yet. The gain setting seemed to change things up quite a lot. Gonna give it a few days listening on this gain setting and see how I like it. Right now I feel it sounds rather funny, but in a good way I suppose.
   
  Thanks for your concern by the way, it´s appreciated .


----------



## Acapella11

It is good that could sort the treble out by changing the gain, interesting. My personal favourite setting was a gain of 5, I thought it sounded better than 1 to 4 and 10 didn't make that much of a difference to me, but I cannot recall what the details were why I preferred 5 . I should check that out again.
   
  The sound signature you are describing points towards a preference towards Tung-Sol 6AJ5 (colder than M8100 and sweeter treble) only the bass will be lesser in quantity, although the 6AJ5-bass quality is good. In my experience you often trade better treble extension and more of it for a loss in bass quantity with these tubes. The CV4015 I am using at the moment is a "colder" brighter tube with very resolved treble and  great in terms of focus and instrument separation. Then again you lose some bass over the Mullards, but it is of good quality. Actually JAN 5654W tubes could be a good suggestion. Clean and nice treble extension, not too much deep bass, but good mid bass punch.
  I won't suggest the other from me preferred Mullard M8100 (with label) because I am not sure you might get the same treble issue you just experienced.
   
  If you are interested in the JAN 5654W tubes, I could send them for a good price from UK; bought out of excitement a couple too many 
   
  Just on a side note, you are using HD650 headphones?
   
  The risk about tube rolling is also the fun of it and there may always be some tubes that won't be in the selection later. Look at it as a little adventure  Tubes are not that expensive after all, plus over time you nail nicely down what you actually really like.


----------



## Nirvana Woman

Quote: 





acapella11 said:


> It is good that could sort the treble out by changing the gain, interesting. My personal favourite setting was a gain of 5, I thought it sounded better than 1 to 4 and 10 didn't make that much of a difference to me, but I cannot recall what the details were why I preferred 5 . I should check that out again.
> 
> The sound signature you are describing points towards a preference towards Tung-Sol 6AJ5 (colder than M8100 and sweeter treble) only the bass will be lesser in quantity, although the 6AJ5-bass quality is good. In my experience you often trade better treble extension and more of it for a loss in bass quantity with these tubes. The CV4015 I am using at the moment is a "colder" brighter tube with very resolved treble and  great in terms of focus and instrument separation. Then again you lose some bass over the Mullards, but it is of good quality. Actually JAN 5654W tubes could be a good suggestion. Clean and nice treble extension, not too much deep bass, but good mid bass punch.
> I won't suggest the other from me preferred Mullard M8100 (with label) because I am not sure you might get the same treble issue you just experienced.
> ...


 
   
  I guess that's true. There's also many variables to consider such as mood, quality of recording, placebo effects, etc. It can be pretty disorienting sometimes.
   
  I use the HD650's yeah. I'd definitely be interested in the jan654w's but I am not sure if it would be worth your effort. That is to say I'd be glad to pay for them but I can't speak on your behalf if you wanna go through the trouble of packaging and sending them. I currently feel that I need to give the m8100's some more time and eventually try some Voskhods if I really end up not liking the Mullards. Luckily, those are typically pretty cheap.
   
  Anyway, I'll be sure to keep posting here .


----------



## Acapella11

It is straight forward for me to pack and send the tubes. I think it is worth trying the JAN 5654Ws. I've got the feeling they could match your taste pretty well.
  If however, you really don't like them, then just send them back.
   
  Please pm me if you are interested.


----------



## Nirvana Woman

I've given the M8100's a lot of time and thought and I just can not get along with them. I really dislike the way they render treble for some reason. It's not necessarily harsh, but there's just something about it that keeps annoying me. It's probably a rather irrational thing I guess. Gain settings didn't turn out to do anything for me in that regard. Now back to the stock GE5654's... Loving it... Yeah the treble is a lot less energetic, the bass is a little weaker and the soundstage narrower... But I like them.
   
  I was lucky enough to have Acapella above me here send me a pair of jan5654w's for an amazing price... Will post my experiences with them when they arrive. Thanks again dude .


----------



## Nirvana Woman

Scratch all that. Loving the Mullards these days... In fact the enjoyment has been so self-explanatory that it's hard for me to realise I was so disappointed with the Mullards for a while. Don't understand anything about it anymore...


----------



## hallom

Hey Guys, according to your experience, which one is the most neutral - least warm sounding tube setup (power+drive) around?


----------



## Audiofanboy

New here, finally felt I should give back a little on this topic after lurking for so long...
   
  The most neutral I've heard for power tubes is -by far- the 6n30p-dr (that's on a MK IV SE mind you, so no 6n6p tubes, it's compared to the Electro-Harmonix 6h30pi, which quite warm and detailed). I have a pair from 1983, that cost me a leg, and they really make the amp sound tighter and more authoritative, and perfectly neutral (almost sounds like SS, but liquid and holographic). Takes the amp to a whole other level; more than the accepted 15% of improvement.
   
  Easier and cheaper, the most neutral driver tubes I've tried among all three compatible families of tubes are the CV4015/M8161 made by Mullard (I have a pair from 1976, with the old military writings and no mullard logo). These sound very balanced, have great 3D imaging and excellent restitution of treble notes (a bit bright a high volumes on my set-up but hardly unbearable on the HD650, although I do find myself often lowering the volume with these tubes) while digging much lower in the infra-bass region that any EF95 tubes I've tried. It's sort of a no-compromise tube, and very un-tubey paired with the 6n30p-dr, but greatly enjoyable.
   
  Still fairly neutral but warmer (more rolled-off highs and less infra-bass), paired the same neutral power tubes would be the Tung-sol 6aj5 tubes mentioned earlier (mine are from 1945). They share some qualities with the CV4015, but slightly less detailed and with a slightly smaller soundstage, but warmer and very enjoyable. It's the best compromise I found in the 6ak5/6aj5 family.
   
  In the EF95 family, I find that my voskhod tubes and CV850 Mullard tubes (the Whyteleafe variety if I remember correctly) tend towards a more neutral sound signature (still quite warm though) than, say, the M8100. I am waiting on a lot of EF91 tubes from ebay, and those are supposed to be very neutral and SS-like as well.


----------



## hallom

Thank you Audiofanboy, the 6n30p-dr supertube is out of budget, but I'm hunting a pair of CV4015 now.
  I use a rocket logo 6J1P-EV gold platinum (with 6N6P OTK gold grid sounds much more balanced in the highs and more power in the lows, then with the supposedly better 6H30Pi-EB, which maybe shines with a different driver), which sounded very precise at the beginning, but now I have the feeling their bass loosened up a bit around 40-50 hours, or maybe I'm just imagining it, but defto I want to try the CV4015.


----------



## Acapella11

Quote: 





hallom said:


> Hey Guys, according to your experience, which one is the most neutral - least warm sounding tube setup (power+drive) around?


 
  For me, the 6H30-EV appear more like the 6H30-DR as described by Audiofanboy. They are my brightest power tube and at the same time very detailed. They can be just the right tube when paired with a not too bright driver tube. The only disadvantage I found was a lesser deep staging. Although the overall performance is impressive, spatial depth is limited, the tubes sound forward.
  If you are in for a straight but rather "hard" and a bit treble biased presentation to match your setup, surely look at 6H30-EV plus CV4015. 
   
  I totally agree with Audiofanboy with respect to the CV4015 and the 6AJ5. CV4015 is my personal favourite: very balanced, very detailed, very good resolution and dynamics. Since both (my 6H30-EV and the CV4015) tend into the bright direction, on my setup, they become fatiguing after a while. In order to avoid this, I have paired the CV4015 (1980, no Mullard logo) with 6N6P-IR (1974), which deliver a wide and deep stage and great dynamics (extended bass and treble). The combination is not very warm, rather natural and neutral, I'd say and my favourite.


----------



## hallom

Acapella11, is the 6H30-EV the same as the 6H30Pi-EB?
  BTW do you guys know anything about this tube? http://www.ebay.com/itm/2x-TESTED-MATCHED-6N6P-OTK-5-Military-GRADE-GOLD-GRID-TUBES-ECC99-E182CC-/251200575992?pt=Vintage_Electronics_R2&hash=item3a7cb899f8


----------



## Audiofanboy

Quote: 





hallom said:


> Acapella11, is the 6H30-EV the same as the 6H30Pi-EB?
> BTW do you guys know anything about this tube? http://www.ebay.com/itm/2x-TESTED-MATCHED-6N6P-OTK-5-Military-GRADE-GOLD-GRID-TUBES-ECC99-E182CC-/251200575992?pt=Vintage_Electronics_R2&hash=item3a7cb899f8


 

 6H30-EV is Sovtek, 6H30Pi-EB is Electro-Harmonix.
   
  EH are more expensive than Sovtek, both tubes have different qualities but the EH might be more detailed and warmer. The EH are stock on the MK IV SE.


----------



## hallom

this is also advertised as PI-EB and Sovtek, I have the same one, so which one is 6H30-EV?


----------



## Audiofanboy

Same tube, different transcription. Sovtek can be advertised both as 6h30p-ev or 6h30pi-eb. Whereas I've never seen the Electro Harmonix advertised as 6h30p-ev. The EB/EV writing means long life (>5000 hours).
   
  It's the same translation problem with 6h6p/6n6p, or 6h30p-dr/6n30p-dr.


----------



## Acapella11

Hi Hallom, as described by Audiofanboy my 6H30 tube is a Sovtek 6H30П-EB and transliterated properly to 6N30P-EV where P is equivalent to Pi.
   
  Your link (below) leads to a tube of that kind:
  http://www.ebay.co.uk/itm/1x-NEW-Sovtek-6H30Pi-EB-Vacuum-Tube-6H30-P-Sov-TESTED-/120963729267?pt=Vintage_Electronics_R2&hash=item1c2a000773&clk_rvr_id=434960185114
   
  PS: If you have the budget and like a deeper stage, keep the 6N6P-IR on the short list


----------



## hallom

Thank you Guys, I can't wait to try C4015, then the next step will be the power tube.


----------



## Audiofanboy

Finally got my latest ebay tube purchase yesterday. 10 used EF91 type tubes for 9 euros, not too shabby I think; it'll keep me entertained for longer than 2 beers at the pub or a movie theater ticket for the same price!
   
  Anyway time for my EF91 shootout. Out of the 10 tubes, 6 turned out to be "pairable", 4 being virtually identical. There were no actual EF91 tubes in the pile, but only CV138 and CV4014 versions, so all UK military (which is why I bid on this in the first place).
   
  First pair I tried were some blue glass CV138 KB/D (crowbar, 6AM6, no logo). Deciphering the old military markings, these should have been made by mullard in 1953 in the Mitcham factory. Both tubes were identical and a had a slightly elevated noisefloor that didn't really impair listening. They're like these ones (the ones of the picture with "6AM6" also written).
   
http://www.dbtubes.com/fr/tube-detail.php?ID=3263
   
  These tubes were actually quite surprising in clarity and transparency, with shimmering natural highs and very a large soundstage with great separation (more wide than deep though, unlike the CV4015/M8161 which I find more holographic and "3D-like"). Bass is a bit loose like all EF91 tubes, but goes quite deep and is great for non-fast music (absolutely great for jazz, less with electronic music). Mids are fine but uninspiring unlike the best EF95 tubes. Overall, one of the most neutral tubes I've tried, but not quite as musical and detailed as the CV4015; the treble-centric presentation can get tiring very quickly though, and the CV138 can sound quite SS-like, which many might not like. I would only use these occasionally for specific genres of music.
   
  Second, I tried two blue glass CV4014 KB/D (crowbar, 6064, no logo) tubes (special quality EF91, more ruggedized on paper than CV138, which it more or less replaces). Military codes supposedly show they were made by Mullard in 1956 in Mitcham factory (which is weird since the literature says these special quality types CV4xxx were made from the late 50s onwards). They are almost identical to the CV138 above in construction but an additional "cage" element below the getter than effectively hides the top of the filament that was visible on the CV138 -so no glow really. They look somewhat like these.
   
http://cgi.ebay.fr/CV4014-KB-D-VALVULAS-ELECTRONIC-TUBES-LOTE-DE-2-VALVULAS-/360538857042?pt=LH_DefaultDomain_186&hash=item53f1ca5e52
   
  Logically these tubes should be better than the CV138 from the same decade, and they are quite nice and very similar, shimmering detailed treble, loose jazzy bass... But somehow, I just couldn't enjoy these the same way I did the CV138. There is an ever-so-slight difference that is difficult to pinpoint that makes the sound of these tubes less inspiring and musical (funny thing is they seem to be cheaper to buy too), maybe colder or more neutral than the CV138. Overall, very good jazz and acoustic tube. I suspect that there are better CV4014 tubes out there, maybe from later decades with a different construction (if anyone is looking to sell a pair of 70s CV4014/M8083 with blue glass, do contact me).
   
  Last tubes I paired and tried were some grey CV138 KB/EN (crowbar, no logo). Decrypting  the codes, these are basically old-world ruggedized EF91 tubes made in 1951 by Thorn-AEI in the Sunderland factory for the UK military.
   
http://cgi.ebay.fr/Thorn-grey-glass-CV138-EF91-pentode-valves-/380453302346
   
  One of the tubes was clearly weaker than the other one, so I'll never really use these for serious listening, but these have a very interesting sound, unlike other EF91 tubes I've tried. Bass is full and pleasant, even though it doesn't go down very low. Highs are still very detailed and natural, but not sparkly or sibilant like many EF91 tubes. Soundstage is quite large and instruments are well separated. Overall, these tubes are like a laid-back version of the mullard EF91 tubes, just less treble and fatter bass (but not bloated), possibly less detailed and not quite as good at staging as the two pairs reviewed above. Very pleasant for calm jazz listening. I'd love to find a cheap pair of these tubes NOS!
   
  Anyway, if you're looking for absolutely neutral or "cold" tubes, the military EF91 variants seem to be a very good choice if you can live with more treble and looser bass.


----------



## Audiofanboy

A few additions to my earlier post after a couple extra hours of testing.
   
  The CV4014 I reviewed above are indeed clearly inferior to the early 1950s CV138, less bass and more metallic treble, not unpleasant, but I have much better tubes to listen to. Interestingly, it's makes me realize how good the CV4015 are. They may seem a bit treble forward, but they are probably the most balanced tubes I have actually. On the other hand, the EF91 family is clearly treble-oriented.
   
  I think I found out what makes the difference between my CV138 and CV4014. Although the military codes KB/*D *on both types show a "pumping process" at the Mullard Mitcham factory, the factory codes on the CV4014 show an *R* for Mitcham, whereas the CV138 have an obscure *J *that, upon further investigation, could be a Tungsram factory in Tottenham bought by Philips (Mullard) in 1952. Different factories would explain a noticeably different sound.
   
  One of the "un-pairable" tubes in the batch was also a CV138, virtually identical to the ones reviewed in construction (only difference I could spot was a few soldered wires at  the base that seem more copper-colored, absolutely identical otherwise), labeled with B.T.R.W and CV138 in a circle, no military markings, no factory codes. My best friend google tells me BTRW is simply British Tungsram Radio Works, basically Tungsram UK at the time. Tube was made no later than 1952, since the factory was Mullard labeled afterwards.
   
  Since it seemed reasonable, I paired that tube with one of the other CV138. Well, guess what, it sounds great, the same as the CV138 above, and possibly with better bass extension and clarity (even though it's difficult to tell with one tube) but very similar. So, yes, it could just be that these obscure Tungsram factory early 50s military tubes are worth investigating.
   
  Has anyone else tested 50s era CV138 tubes?


----------



## Acapella11

Thank you Audiofanboy for sharing these detailed impressions 
	

	
	
		
		

		
			





. 
   
  The EF91 tubes haven't been looked at much, so it is really great you tried them! It sounds like there are some hidden gems from a formerly not mentioned Tungsram factory.
  How long did you burn them in? May I ask you to update this after each tube has been burned in like 40 hours (if you can be bothered) with a ranking and short summary per tube?
   
  I personally found my CV4014 (KQDD/K, 83-31) although very nice in terms of treble extension and quality too "head-biased" as in that the whole signature shows a bias like a triangle standing on the tip with the treble most emphasized and the bass least.
   
  From what you wrote, it also sounds like it might be interesting to have a closer look at different CV4015 tubes (years, labels) as this still comes out as your (and my) most favoured tube. Just a thought. If anyone else uses a CV4015, he/she might like to post details and impressions.
   
  Nice work.


----------



## Acapella11

This is slightly off topic, but I thought it might still be interesting.
   
  For many this an old story but I haven't been paying much attention to cables due to them being one of the least sound influencing parts in the setup.
   
  Well, then I connected DAC and LD with a new phono cable. Both were different kinds of oxygen free copper budget Hifi cables in the range of $30. Now, the difference is quite well noticeable. With one (Atlas Elements, old plug) the sound is lusher, warmer and voices have more body. On the other hand with the second one (QED Profile), the sound gains dynamics, sparkle and definition.
   
  Actually, in my ears the difference is great enough to say that the overall sound is a bit too boring for me with one (Atlas) compared to the other (QED). System matching is the key, as usual.
  With respect to tube rolling, of course relative difference can always be concluded but for some statements it is good to keep the complexity of the setup in mind (YMMV  ).


----------



## Audiofanboy

Yes, I'm sure there's also much left to test with the CV4015. I think the later early 80s tubes with the small logo might be different or slightly inferior to the late 70s early 80s large logo, from what I've read; so I wouldn't worry too much about those versions. On the other hand, I've seen on ebay (and received by mail in an other used batch a few months ago, but one was shattered and the other one dead, got my money back) older CV4015 with no logo, different glass, inner construction and getter shapes; so I know there are many versions left to try. No idea how they sound though.
   
  About burning in those EF91 tubes. Well, it's sort of a moot point really since all those tubes were used (quite used in fact, many are more like dying), so no burn-in is required (couldn't tell the effects anyway). Let's say it was more of a " test and toss" sort of review for those old tubes. Now, I need to find them NOS for a few bucks, which might be challenging.
   
  Out of curiosity, do your '83 CV4014 have a mullard logo or just military codes? Blue side glass? I definitely agree with the triangle presentation, I found my '56 CV4014 to be this way too. Very clear, airy and large treble on the top of the head, and loose anemic bass below that it just sort of there and not dynamic, giving the impression of a biased soundstage. Which is why I just don't see myself using these anytime for serious listening. Again, the CV138 were better in that aspect with decent bass and a more balanced soundstage impression.
   
  Incidentally, in that same batch of broken tubes I just mentioned above, I also had two CV4014 from the early 70s (only one worked though, other one had lost vacuum). I re-tested the one that worked (no logo, arrow, 6064 7301 CV4014 KB/D => Made in Mitcham in 73 by Mullard, halo getter unlike the older tubes I reviewed) with another good tube (the Tungsram CV138). Again, it's difficult to know what you're hearing with one tube, but it definitely sounded better than my '56 CV4014, more musical and dynamic and better bass (deeper and tighter, still loose though). Sounded quite like the old CV138 in fact. If I were to pay more than a few bucks for a pair of these tubes, this is probably the time period I would aim for, just like my '76 CV4015.
   
  Has anyone tried the CV5377 I keep seeing on ebay? They're supposed to be an even "specialer" quality EF91 than the CV4014, but I keep seeing the 1985 version around, which is kind of late. Ultimate EF91 tubes or last tubes out of Mullard factory with low quality control...?
   
  About cables, 6 months ago, I took the decision to replace all my interconnects with DIY cables (Mogami cables and Rean RCA jacks, I had recabled my HD650 with the same brand and a neutrik jack a year ago already). I wasn't expecting much going from cheap hifi cables to quality copper DIY cables, but I was quite impressed with the results! Better transparency and dynamics, better separation; not a night and day difference (unlike the headphone cable) but a solid improvement all around. Cables matter. At least once you've reached a critical point in your set-up where every small difference can be heard.


----------



## Acapella11

Hi Audiofanboy, these are my CV4015 and CV4014 tubes:
   
  CV4015: no Mullard label, halo getter, 000-4015, CV4015, KQDD/K, 80-49, picture: http://www.head-fi.org/t/563884/lightbox/post/8892857/id/725931
  CV4014: no Mullard label, halo getter, 000-4014, CV4014, KQDD/K, 83-31
   
  I also heard good things about Mogami cables. Did you solder the cables yourself?
  Thanks for the detailed response.


----------



## Audiofanboy

Yup, soldered 'em myself; was my first DIY soldering job. Pretty difficult with a cheap cheap Chinese awful soldering iron, but actually pretty easy once you get the hang of it (despite the Chinese iron).
   
  I do recommend the Rean RCA plugs (Neutrik NYS373 actually, Rean being like the cheap Neutrik essentially), convenient, cheap and easy to solder.
  
  Here's the best link I found that has, like, everything you need to know to solder some cables.
   
http://www.hometheatershack.com/forums/remotes-cables-accessories-tweaks/13000-how-solder-illustrated-diy-guide-making-your-own-cables.html#axzz2HDSiRXFU
   
  Last piece of advice: kids, don't buy 5$/€ irons, you'll waste more on burnt materials and parts than you saved cheaping out on the soldering iron itself... And you'll eventually get another iron anyway.
   
  Thanks, for the details on your CV4014 and 4015 tubes. it's that kind of detailed information that I always find myself needing when I'm looking at ebay ads...


----------



## Keevs

The Little Dot MkIII is my first tube amp, so I am still a novice in this regard.

 I recently bought some 6N6P power tubes to replace the original ones, and I get intermittent cut outs on one of the power tubes with a pop and comes back on. I swapped it around and the cut out follows to the channel of that one particular power tube. Would that mean a faulty power tube?


----------



## Acapella11

Exactly. Let the seller know about it.


----------



## Keevs

Thanks Acapella11. What a bugger. I was enjoying those power tubes as they seem more dynamic.
   
  How does 6H30 power tubes compare to 6H6N tubes? Are they worth the significant extra cost as more then double the price of a 6H6N?


----------



## Acapella11

Hi Keevs, in my ears the 6N30-tubes are worth the price of an 6N30P or 6N30P-EV, although I couldn't state that for the expensive DR-tubes, simply because I never heard them. I have heard the difference to 6N6P with Sennheiser HD650s and I found found it remarkebly.
  But - I still think the driver tube can make more of a difference. Personally, I would recommend getting the CV4015 and if you haven't got them yet a pair of M8100 and Tung-Sol 6AJ5, followed by the power tubes. GE JAN 5654W are also very nice. I am not going into detail now in terms of the differences. It is written at the start of the thread and more within. Just search within the thread for the keywords.
   
  However , if you need to make up your mind about a new pair of power tubes now, well, 6N6P are certainly good tubes, 6N30 are better in terms of dynamics - more attack and also more detail. You could also consider 6N6P-IR tubes - cheaper than 6N30, much less forward, deepest stage, nice treble extension and bass punch, a bit warmer than 6N30 tubes and they pair beautifully with CV4015s .


----------



## Audiofanboy

If you have the extra cash, the Electro-Harmonix 6h30Pi are quite nice, probably some of the best power tubes you can get before the 6n30p-dr. They're detailed, dynamic and warm and pair well with sennheisers. Never tried the 6n6p (or -i or -ir), but the best ones out there seem to fare quite well too and are cheaper. Bear in mind the 6h30Pi are rated for 5000 hours minimum, so it's kind of an investment in a way compared to other power tubes (same goes for the DRs, 10000+ hours, might outlast the amp).
  
  i just re-tried the 6AJ5, and I must say these are still the best EF95/6AK5 look-alikes that I've tried. Very spacious, just warm and tubey enough with beautiful mids and vocals, just a bit lacking in the deep bass and upper treble compared to the CV4015, but that makes for a more laid-back listening.
   
  Still, the CV4015 would be my choice with Senns, especially with 6n30/6h30 type tubes. More revealing and better extension. A bit too much extension sometimes actually. With these tubes, I find myself having to turn the volume down a notch after setting what would normally be my comfortable pleasure level; or else my ears might hurt a bit and ring the next day... 6AJ5 (lower gain that 6AK5) are more like the opposite; I find myself pushing the volume occasionally beyond my comfort level, because it doesn't feel dangerous (probably still is...).


----------



## Acapella11

Audiofanboy, if you ever have money to burn, try the 6N6P-IR with the CV4015. It sounds a little more laid back (volume goes up  ), gives quite some of the space of the 6AJ5 while keeping treble and bass with the CV4015.


----------



## Keevs

Thanks Acapella11 and Audiofanboy for your suggestions. I might make that investment in a good power tube then.

 I initially got a 2nd pair of 6N6P gold grids as a backup power tubes to the MkIII stock ones. But when they arrived and I plugged them in, I noticed a real increase in power and dynamics for the MkIII, which I really liked, unlike one of the 6N6P decided to cut out. I've contacted the seller and he has sent a replacement.
   
  So that got me realizing that power tubes can make a difference. I will for sure start getting some driver tubes soon. Already have the Voshkods and they are very nice. Next aim is for the M8100 and CV4015.


----------



## Audiofanboy

Speaking of 6N6P-IR, does anyone know how many hours they are rated for? Since the regular 6N6P-I are only rated for 500 hours.


----------



## mordy

According to what I found on the internet, the letter R as the last letter of the tube designation means:
   
  [size=x-small]R - extra high reliability (10000 hours and more)[/size]
   
  This is certainly good news for durability.


----------



## Acapella11

I have got no number, but yeah, it said extra high durability for me.


----------



## mab1376

I got the Electro-Harmonix 6h30Pi with my MK IV SE, is there even any point to upgrading? I'm certainly not splurging on those DR super tubes.


----------



## Audiofanboy

Critically speaking, no there is no point in "upgrading" to 6N6P type tubes on the IV SE. Might be about as good or just a different flavor as the 6H30, but it shouldn't be better, hence the prices. The only technically logical upgrade from the Electro-Harmonix are the 6N30P-DR (which make a very audible difference, and make every driver tube sound great and solid; but cost a leg, although you can negotiate with the sellers a bit, and get away with just paying an arm, which is what I did, and I don't regret it).
   
  I am quite curious about the 6N6P-IR though. I would love to try a pair for cheap, even though it seems silly to spend more money on power tubes at this point... I guess I could sell my EH 6h30Pi I'm not using to save some cash.


----------



## Acapella11

One satisfying scenario of tube rolling with the LD would be, just from my point of view: 
   
  1.) MKIV SE to have the better LD and you get already 6N30 + Mullard M8100, both are good to have and certainly better than the stock 6N6P and 5654 tubes
  2.) nice driver tubes, which are suggested plentiful in this thread. Three to four pairs should be sufficient, if you don't get addicted 
  3.) another (non-6N30) power tube pair, because it will change the sound and you realise what a powertube can do. I'd suggest the 6N6P-IR, because I think they give high quality sound quite different to 6N30 tubes.
   
  That should give you a great setup, you never wonder whether the MKIV would have been better or whether you should buy 6N30 tubes or not, you got them all.


----------



## mojorisin35

I want to order the little dot MK III, but before I do a couple of questions for you pros.
 I am a complete newbie to tube rolling and I will be running my beyerdynamic DT1350’s with the amp and was wondering if the upgraded tubes available at order are a good choice? 
Or is it better to get stock tubes and buy upgrades after.
 2x 5654/5725: 20 USD
 2x 6H6PI/6H6n: 35 USD
 Upgrade and replace stock 5654 driver tubes with M8100/CV4010: 45 USD

after reading this thread i was considering Electro-Harmonix 6h30Pi and Mullard CV4015's.
what says you pros?

Thank you 

Gary


----------



## Audiofanboy

Looking back now, even for the MK IV, it is waaay cheaper to get tubes off of ebay (even without a good deal, except maybe from way-too-expensive-yenaudio) than to get them from LD.
   
  So for the MKIII, definitely just get the stock tubes, and have fun tube rolling for cheap afterwards.


----------



## Acapella11

Agree with Audiofanboy, I would not get the upgrade tubes from LD.
   
  Respective the choice of upgrade tubes, it all depends on the brightness of your headphone. If it is as relaxed as the HD650, the 6H30P or 6H30P-EV  power tubes + CV4015 could be just what you want. I am not sure - but I think I've read the Beyerdynamic DT1350 is not exactly that relaxed. If this is the case you may want to consider a pair that fits better otherwise the sound might get too bright. For example 6H30P (-EV) with Mullard M8100 or Tung Sol 6AJ5. Another pair would be based on the CV 4015s, then paired with with 6N6P-IR (my favourite) or nice 6N6P. What I would not suggest to do is just to fit the driver tube to the power tube, but rather the other way round. The 6H30P tubes sound great, are regarded high and they are expensive. So you kind of want to keep them. But, I personally think the CV4015 is the upgrade to do and then I would fit the power tube to it. If you first get the CV4015 _only_, you can find out whether you like the sound. I would take it from there.


----------



## hallom

Hai Tuberollers!
   
  I got a pair of CV4015 from julienbell92, thanks for him this way too, he still has some, if you are thinking about them night and day like I did lol. They are Philips made, one is in '72 the other who knows, but the paper box was similarly yellowed
   
  So, upon first listening: indeed they are neutral and have the emphasis on the mids, just as much as I miss the punchy subterranean bass from the 6J1P-EV gold platinum grid's. Not that they lack of bass but its just not that authoritative and present compared to the latter, however they have more space in them which is a good thing. And funnily they sound better, particularly bass-wise with the Sovtek 6H30-EV's, whereas the 6J1P-EV's are better with 6N6P gold grid's. But unfortunately I don't like how the 6J1P-EV's bass loosened up with time - still punchy but less precise, - they became a bit too tubey for me, but not overly disturbing, I might give them an other chance after having some time with the CV4015's.
   
  So Acapella11, do you say 6N6P-IR further improves the CV4015? I would go with the DR supertube, but costs too much for me now to justify it.
   
  Only if I could combine the precise and punchy bass the 6J1P-EV had in the beginning (I thought yes! I have found the one tube rules all) and the neutrality and soundstage of the CV4015. But I start to realise the law of compromise is in effect here too.
  BTW according to your experience how does the sound of the CV4015 change when burned in? Do they also loosen up like 6J1P-EV?


----------



## Audiofanboy

My experience with burn-in on the CV4015 was that the bass got noticeably tighter after a couple dozen hours, a bit more clarity, and the treble got ever-so-slightly less sibilant (it wasn't actually sibilant, but a bit spiky, still is on some songs now). But they sounded balanced, wide and airy even new.
  
  Looking forward to your impressions after burn in of those '72 tubes!
   
  I just won an auction for 28 EF91/CV138/CV4014 tubes, so expect a new EF91 shootout in about a week.


----------



## Audiofanboy

Reading over the last post again, I do remember the same odd "loosening up" on both kinds of 6J1P-EV i tried.
   
  First pair "6sh1p-ev" '71, rocket, CCCP, no grooves, sold as '75s from some dude in Budapest were absolutely awesome out of the box. Balanced and detailed, bone dry bass (like the CV4015 actually) and great treble that made my ears bleed, but great yet painful. 95 hours later they had transformed into balanced dull tubes with tight-ish bass and rolled off mids and treble. Never liked them again...
   
  On my 6j1p-ev gold grids, grooves, rocket, from '86, I found the sound punchy and very V-shaped out of the box, detailed but no really airy. Didn't like them as much as my other pair because they were less balanced and the bass seemed kind of garish or not-true-to-life. 105-110 hours later they had become a perfectly enjoyable v-shaped (not V anymore) clone of the M8100/CV4010, a bit less warm and with more authoritative bass. Last I listened to them paired with the 6n30p-dr, they were probably my 2nd or 3rd favorite 6ak5/ef95 tube. I could live with these as drivers if I needed to.
   
  The CV4015 did the exact opposite after burn-in. Started looser and became tighter; very tight in fact. Hope that helps compare the burn-in experience with the 6j1p-ev a bit.


----------



## hallom

Thanks man, I'm getting more and more curious


----------



## Audiofanboy

Btw, anyone else using an MKIII or IV with Hifiman HE-400 or 500?
   
  I just got a pair of HE-400, and I'm wondering with gain setting might work the best to drive these. So far, gain 10 seems catastrophic (no bass, bleeding highs) and 3 seems to lack definition (tons of bass though); I'll try 4 and 5 tonight and see... Kind of looking for a gain setting I can use with both the HD650 (x10 up to now) and HE-400.


----------



## mab1376

Quote: 





audiofanboy said:


> Btw, anyone else using an MKIII or IV with Hifiman HE-400 or 500?
> 
> I just got a pair of HE-400, and I'm wondering with gain setting might work the best to drive these. So far, gain 10 seems catastrophic (no bass, bleeding highs) and 3 seems to lack definition (tons of bass though); I'll try 4 and 5 tonight and see... Kind of looking for a gain setting I can use with both the HD650 (x10 up to now) and HE-400.


 
   
   
  I don't think OTL amps are really designed for low impedance/high demand ortho headphones.
   
  Yeah you'll get some sound, but I'm sure it'll be far from optimal as you've already found.
   
  Personally I have the HE-500 in my sights and I plan on either using a good solid state amp, or saving for a Woo WA22 since it is transformer output and has much more output power.


----------



## Acapella11

Hallom, to be honest, I don't remember the exact changes over the burn in period, but I remember that I first wasn't enormously convinced by the bass, however anything else =). What I can say now is that they feel punchy, the quality is very good and quantity is totally fine for me. The 6N6P-IR add some deep bass, which I very much like. They are also V- or rather even U-shaped for that matter.
   
  Just wait until your burn is complete and see how the bass is then. Personally, I would find it more interesting to try the 6N6P-IR than getting another pair of 6H30P tubes (-DR in this case). Although, to be fair you will probably buy the best of those. But, be not worried that 6H30P > 6N6P, generally speaking, but 6N6P-IR starts with 6N6P...  They produce quality sound and you wouldn't spend as much money. Of course I cannot give any guarantees . Pairs of tubes sound differently too and tastes vary.
   
  As Audiofanboy described, I also noticed differences between 6J1P-EV tube pairs and the burn in was similar for me. My favourites were from 1975 because of a stronger bass. To be fair, I liked the 6J1P-EV tubes more in the beginning with a sparkly treble, they sounded more exciting.
   
  Audiofanboy, I have HE-500 headphones and run them on the LD MKIII, which is generally considered a no go  (and I actually like it with the tubes I have  ). I am going to upgrade sometime soon tho. HE-500 and HE-400 are quite different in terms of demands on the amp. HE-400s are definitely easier to drive and hence a logical option for the LD MKIII or IV. In fact they might be superior for some people to the HD650 because they are supposed to sound really good even without highend amps while the HD650 rather require highend amps to really shine . Also if you like a faster and opener sound signature, you may prefer the HE-400s. Because the HE-500 is more difficult drive, I assume, I am using a gain of 10 at the moment. I do lose some dynamics when going down to 5. On 10, however, the volume knob is only turned to 12 o'clock max while I am listening. Formerly, I always used 5 (AKG Q701) and I thought it was the best setting in terms of dynamics and focus. But the differences were not huge between the settings.
   
  Let us know which gain settings you found most useful, as I think the HE-400 may become more of a topic here with it's increasing popularity and if it sounds good with the LD MKIII / IV. After you tried all the gain settings, how do you like the sound?


----------



## Acapella11

mab1376, +1 on the HE-500 
	

	
	
		
		

		
		
	


	




. I do not want seed the the wrong equipment discussion in this thread, so I am keeping it short and won't answer further questions . HE-500 and OTL amp can fit nicely. Give this a read: http://www.headfonia.com/lafigaro-339-my-fav-otl-amp/


----------



## hallom

What I can say, the bass has greatly improved even after a few hours, just as Audiofanboy said. It's getting more and more interesting, I'll update you once they are burned in more.
  In the meantime, do you have a tip where to find cheap 6N6P-IR tubes? Because the ones on ebay don't seem to be matched pairs.


----------



## Acapella11

OK, let's keep the posts rolling 
   
  Hallom, I got my 6N6P-IR from this site: http://tubes-store.com/product_info.php?cPath=30_78&products_id=519
   
  They are $ 13 / pc + $ 8 shipping from Russia. I actually didn't worry about matching but you can contact them before the purchase in this respect. If I remember correctly, the packaging was done very well and it was delivered within one and a half weeks (UK) although it said 12 days on the homepage. Quite liked the service.


----------



## Audiofanboy

Yeah, I know than OTL amps are by definition not well suited for driving orthos, but I can't exactly justify buying yet another headphone amplifier... And I do like the tube sound coming out of my maxed out IV SE. From what I'd read, the HE-400, and by extension the 500, should be about the only orthos "driveable" by OTL tube amps such as the MK III/IV (and I've seen more than a few people with that setup around here). If it can be driven by an iphone (even poorly), the 100mW of the MK IV SE should at least get it moving correctly at reasonable levels?
   
  Anyway, after an evening of testing the HE-400 on the IV SE (reviewed with the CV4015, so we're still on topic here, somewhat) and playing with the gain switches, here's what I heard. x3 gain is ugly. Not unpleasant but bloated and lacking in resolution. For a while last night, x4 gain seemed to be the best compromise, so did x5, with some bass and pretty good separation and decent soundstage. But, putting the amp back on x10 gain as Acapella had suggested definitely shows better resolution and instrument separation (which is why I had the amp in that position with the HD650 in the first place, plus it seemed reasonable to max out the gain with a hard to drive ortho).
   
  There is still some getting used to with the HE-400, but x10 gain might be indeed be the best setting, all things considered. It seemed catastrophic yesterday probably because the HE-400 felt tonally out of whack compared to the HD650. Still, on gain x10 or even 4 and 5, I do find that the bass (like below 80-100Hz) is somewhat lacking. It's there but just not as much as I read it is supposed to. This might not seem abnormal if you come from the K701/702 but coming from a well amped HD650 in an optimized setup, I was used to hearing more bass (not sub-bass, which the 650 kind of rolls-off).
   
  Btw, I'm having some treble wrapping my head around the whole output impedance, load impedance, damping factor thing between different types of headphones and amps, but correct me if I'm wrong. On an OTL tube amp with very high output impedance paired with an low impedance ortho, the damping factor is really low. The higher the gain on the amp, the more voltage I'll output which should be able to make the headphone louder, but might not give them more current and might not drive them better. If I lower the gain on the amp, more negative feedback should be going on, which improves the damping factor, which might help driving the headphone...? Or am I just confused? Just trying to make sense of what I hear...
   
  About the HE-400 and CV4015, after a few hours I am hearing some glorious sound though. Outrageous airy detailed flying treble, gorgeous and fleshy clear upper mids and mids, and a solid mid-bass kick that is making me rediscover rock music after a falling out for a few years. Just the bass is troubling me. Maybe it is the CV4015 that isn't giving me enough bass and sub-bass in this setup, or maybe the IV SE really isn't optimal to drive the HE-400 (even though I really am starting to like what I'm hearing).
   
  In terms of volume, on x10 gain, I don't usually go over 9 o'clock for music and 10 or 10:30 for videos (sound in videos). Acapella, what do you think of the 6AJ5 paired with the HE-500 btw?


----------



## mab1376

I just ordered some 6N6P-IR tubes to try with my 6AJ5 tubes.
   
  Had no real reason other than curiosity of the sound signature.
   
  I'll post some impressions once i get them burned in.


----------



## Acapella11

Audiofanboy, you have been deeper into this topic than me but what I read was that in an ideal case scenario the output impedance of the amp should be 1/8 of of the impedance of the headphone, that is to allow a linear frequency reproduction. This is a good guide line but there surely is a tolerance. Only if you move too far away from the ideal, the mids will be bumped relative to over frequencies, if I remember correctly. Then, the 6H30P tubes are really good with mid bass but not as good with with deep bass, I thought. Maybe this was less noticeable with the HD650 but now becomes more obvious with the HE-400 (deep bass? try some 6N6P-IR  ). Deleted entry - just flew over your text first time .
   
  6AJ5 are great sounding tubes but because the HE-500 converts all the power it can get from the LD into dynamics, the 6AJ5 sound a bit too anemic, whatever power tube you take. You really can get addicted to the mids, which are already great with the HE-500 but it just isn't lively enough for me.
   
  mab1376, cool. What are your current power tubes? Please keep us posted.


----------



## mojorisin35

Ordered my mkiii....the wait.... I have some 6n6p gold grid on the way. These ones
http://www.ebay.ca/itm/350688546177?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649#ht_5446wt_1150
And I am looking for sylvania gb5654 gold grids are these similar at all?
http://www.ebay.ca/itm/120742819812?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649#ht_500wt_689
I would also like to find some Hytron 6AK5WB to try

And it begins....
Gary


----------



## mordy

Hi Mojo35,
   
  There is no such a thing as Sylvania gold grid tubes. What you are referring to are Sylvania tubes with gold plated pins. Some people are getting insane prices for these JAN (Joint Army and Navy) 5654 tubes.
  As mentioned previously on this site, inexpensive Sylvania JAN 5654 tubes made in the 60' and 70's are identical to the ones with the gold plated pins, but without the gold plating on the pins, and they sound exactly the same. The way to identify these inexpensive tubes is to look for Contract Number DSA 900  on the box. Here is an example of the print line on the box: CONT. NO. DSA 900-67-C-9983 (This tube is from 1967).
   
  Good luck tube rolling! I myself the have the 6N6P gold grid power tubes together with the Tung Sol 6AJ5 driver tubes, and in my system I am perfectly content to stay with this combination. I did notice that there is a slight variation in the sound between different years of the Tung Sol 6AJ5 tubes. The 1945 ones I tried first were very good, but a later 1960's pair had even stronger bass. The mid range is excellent, and the treble is absolutely gorgeous with crystal clear shimmering highs.
   
  Would like to try the 6N6P-IR tubes, but I am waiting to find a bargain - I never paid more than $8 for a tube yet.


----------



## mab1376

Quote: 





acapella11 said:


> mab1376, cool. What are your current power tubes? Please keep us posted.


 
   
  I currently have the 6H30PI, I'm looking for better bass with my Beyer T70's.
   
  They sound great with my Auzentech Bravura sound card with AD797 opamps but it needs a little warmth. With the LittleDot the mid bass is lacking and sub bass is almost non-extant.
   
  Which is strange to me because my HD650's have a pretty good kick with metal and electronic music.


----------



## britt2001b

Quote: 





mordy said:


> Hi Mojo35,
> 
> There is no such a thing as Sylvania gold grid tubes. What you are referring to are Sylvania tubes with gold plated pins. Some people are getting insane prices for these JAN (Joint Army and Navy) 5654 tubes.
> As mentioned previously on this site, inexpensive Sylvania JAN 5654 tubes made in the 60' and 70's are identical to the ones with the gold plated pins, but without the gold plating on the pins, and they sound exactly the same. The way to identify these inexpensive tubes is to look for Contract Number DSA 900  on the box. Here is an example of the print line on the box: CONT. NO. DSA 900-67-C-9983 (This tube is from 1967).


 
   
  I've got to admit the Sylvania JAN 5654's sound just as good as the "gold pins". I haven't used the JAN's for a while because I was spooked by a blue glow from both tubes. I have since learned that the "blue glow" isn't a bad thing. Your post prompted me to give them a listen again and I'm immensely enjoying them now.


----------



## Acapella11

mab1376, The HD650 is very good with kick bass and bass generally, although I found it on my LD more blurred compared to the HE-500s. I am not familiar with the T70 but after a glance through Head-fi it seems that it is not the most bassy type of headphone.
  
  britt2001b, The Sylvania JAN 5654W tubes were a few months ago my favourites =) and they are nice - a somewhat warmer and darker version of the very nice GE JAN 5654W. But after all the fun..., I am content now with my LD tubes .


----------



## Audiofanboy

After spending a few days with the HE-400, I took the chance to roll some tubes from my stock with new impressions.
   
  First, I hate to admit it but tube rolling makes much less of a difference on the HE-400 than it did on the HD650 (driver tubes, didn't touch power tubes). The sound balance changes somewhat but soundstage and resolution just don't seem to be affected that much (even trying the HE-400 on my iBasso D10, portable SS amp, I'm not sure I could tell the difference in an ABX test, although the IV SE *is* better and more detailed). This being said, there are differences.
   
  I tried my good old (stock for me) CV4010 again. Hadn't used those in a while as they had started to feel too warm and un-neutral, with an over-emphasized bass (and not sub-bass) hump. On the HE-400, they give a pleasant and open presentation with good instrument separation, are just a bit warm, and the extra bass and rolled-off highs make the headphones seem less spiky. Still, it lacks PRAT and feels unnaturally warm on the HE-400. And there was still not enough bass.
   
  So, I tried the 6AJ5 again (had tried them right after getting the headphones and was originally disappointed). This time, I felt the 6AJ5 complemented the HE-400 quite well with a great airy soundstage and shimmering highs (but not sibilant). Still a lack of bass and no sub-bass, and the whole presentation could have been more dynamic, but it feels like a safe and pleasant everyday choice; not a very challenging sound in any case.
   
  I am starting to think that none of the tubes in the 6AK5 family can really be quite dynamic and "fun" enough to get the HE-400 moving (and the HD650 also in a way, which are a bit on the dark and slow side in the first place). Not that the 6AK5 tubes are inferior, they are in fact very well suited for headphone amps, but they are always a bit rolled-off in the extreme frequencies, which makes them an easy listen. The 6AJ5 come close to being dynamic but aren't exactly "fun" and challenging like the CV4015 or even some spiky treble EF91 tubes can be...
   
  Speaking of the CV4015, whereas their detailed upper-mids and treble complemented the HD650 very well (made it a tad too bright in fact) while maintaining a tight bass with no hump and just a touch of sub-bass (difficult to get on a tube amp like MKIII/IV), those same characteristics make them difficult to listen to with the HE-400, at least for some types of music. Guitars sound the best I've ever heard, so do all the crashing treble-y brass instruments, but the balance between bass and treble just seems out of whack. Maybe the lack of bass and sub-bass I'm hearing is just brain burn-in, but still it's a bit annoying as these are by far my most engaging tubes.


----------



## mab1376

Quote: 





acapella11 said:


> mab1376, The HD650 is very good with kick bass and bass generally, although I found it on my LD more blurred compared to the HE-500s. I am not familiar with the T70 but after a glance through Head-fi it seems that it is not the most bassy type of headphone.


 
   
  Like I said though, they have a great sub bass kick with my soundcard, just lacks a little warmth for my taste.


----------



## mojorisin35

Thank you for all your input i now have these on the way.
5 NOS Sylvania Miliary grade 5654 - 6AK5W - EF95 black plate
http://cgi.ebay.ca/ws/eBayISAPI.dll?ViewItem&item=221178531683#ht_500wt_922

Looks like, the tubes will be in my possession before the amp. I look forward to contributing more to this thread than questions.

However another question does anybody use the beyerdynamic DT 1350's with there amp? And if so what tubes are you using?

Gary


----------



## Acapella11

Quote: 





> _I am starting to think that none of the tubes in the 6AK5 family can really be quite dynamic and "fun" enough to get the HE-400 moving (and the HD650 also in a way, which are a bit on the dark and slow side in the first place). Not that the 6AK5 tubes are inferior, they are in fact very well suited for headphone amps, but they are always a bit rolled-off in the extreme frequencies, which makes them an easy listen. The 6AJ5 come close to being dynamic but aren't exactly "fun" and challenging like the CV4015 or even some spiky treble EF91 tubes can be..._


 
   
  Hi Audiofanboy,
  I have exactly the same impression 
	

	
	
		
		

		
			





, which is why I keep the CV4015 tubes.
   
  Quote: 





> Speaking of the CV4015, whereas their detailed upper-mids and treble complemented the HD650 very well (made it a tad too bright in fact), ... , those same characteristics make them difficult to listen to with the HE-400, at least for some types of music.


 
   
 This effect also happens with the HE-500, although the treble seems to be not as refined with the HE-400. A darker phone / or a decent level of "relaxation" of the headphones is important to make 6N30P + CV4015 work non-fatiguing. I have read that the HE-400 sounds a bit more treble spiky and there are also frequency response curves, which show different quantities and qualities of treble spikes between HE-400 and HE-500. Check this out for details:
 http://www.head-fi.org/t/551345/hifiman-he-500-he-as-in-high-end-please-post-your-impressions-loan-pair-for-uk-pg-28/2445#post_9024251
  
 I could listen a bit to 6N30P-EV + CV4015 but it becomes fatiguing. 6N6P-IR tubes fix that for me whilst keeping dynamics that are reduced with 6N6P tubes.
  
 Consider that I am saying this with regard to my current headphones. I think 6N6P tubes perform better when your headphones fit from the design already the performance of the LD MK III / IV, which means they have 120 ohm + and go well with 300 mW (e.g. Sennheiser HD650, 103 dB sensitivity, 300 ohm impedance) or very good sensitivity with at least a bit of impedance (e.g. Denon AD-H5000, 106 dB, 25 ohm) in order to not generate a noise floor.
 Now, Hifiman HE-500 are magnetostatic  headphones (89 dB, 38 ohm) and sensitivity is low as well as impedance. This makes these headphones not very useful for headphone amps as the Little Dot III / IV. Theoretically, they just need more power to work fine. However , I think here is where the higher gain tubes can shine: Gain for driver tubes: EF 91 > EF92 > EF95, for power tubes: 6N30P > 6N6P-IR, 6N6P-I > 6N6P. The sound quality of CV4015 tubes from the EF 92 family seems to find no match in the EF91 family (Audiofanboy will update us on this one I guess  ) and 6N30P sound stunningly detailed with a very precise bass, not very deep though. 6N30P tubes tend to sound a bit bright and hard, this is the main disadvantage I found. The 6N6P-I tubes sound warmer and the 6N6P-IR sound for me like a higher quality version of the 6N6P-I, as in more spacious, deeper bass whilst keeping treble extension. So after all, it comes for me down to a pairing of an EF92-tube (CV4015) with a 6N6P-I type power tube (6N6P-IR).
  
 I am explaining this to put you into the picture that I am basically running a headphone on the LD MKIII, which is not considered suitable but still I think the sound is good. Only and importantly, the gain of tubes plays a more important role for the sound quality. 
  
 Audiofanboy, interesting observations overall, I can exactly see where you are and I guess you are already trying to fit the power tubes to the CV4015 
	

	
	
		
		

		
		
	


	




. It might not work with every phone but I found this path giving the best sound.
  
 EDIT: Updated thoughts on the gain of tubes with regard to sound quality on the Hifiman HE-500.


----------



## hallom

Audiofanboy and Acapella11, I'm exactly in the same situation. So I'm having high hopes for the 6N6P-IR. Maybe the perfect setup, if it adds a kick and body to the subs. Right now, I'm waiting for an answer about matching and if it's +, I'll buy them straight away. I listen my LD MKIV with HD 580 and HD 25 1-II. And lately as a preamp with these: http://www.fl-electronic.de/neuklang/images/x-Space.jpg, Mission X-space, they work very well together, balanced like I never heard before from my flat panels, it was surprising. Surprisingly awesome, fat and round dynamic bass which doesn't distort, which is notable especially because the X-space isn't exactly a bass champ but an air surfer. And with LD now it stays dynamic at low volumes too. This is why we love tubes after all.


----------



## Steelsix

I've been researching tube amps for a couple weeks and am minutes away from pulling the trigger on a Little Dot MK IV.
   
  I thought I'd better research the tubes real quick to determine availability and replacement cost. A quick Google search and BAM! here's this thread.
   
  Amazing job OP. Amazing to find stuff like this. I could be just starting out on a new interest or hobby and find stuff like this.


----------



## Audiofanboy

As promised, and after getting a metric ton of tubes in the mail, here are my thoughts on different EF91 tubes.
   

   
*Mullard CV4014* KB/D 6064 made in Mitcham, O-getter and open structure below getter, blue side glass and inside visible (no cage like element between anodes). Both tubes are identical in construction and flash when turned on (they dim shortly afterwards), one only has military markings and was made in 1972, the other also has the old Mullard logo and M8083 and was made in 1968. They sound exactly the same. They have a very large soundstage, a very airy treble forward presentation with great instrument separation. Highs can be a bit spiky and borderline sibilant but are always extremely natural and spot on for vocals. Bass has weight and quantity despite being quite loose (but if it's in the song, you'll definitely hear it loud). Mids are fine but not exceptional. This tube feels like a looser bass-ed CV4015 with more space and treble, useful for specific types of music. They really wake up the HD650, but are a bit spiky on the HE-400 (and bassy). My impressions match what's on the first page.
   

   
  Another *Mullard CV4014* KB/D 6064, made in Mitcham in 1958, identical tubes with same date code, blue glass, a cage like element between the anodes, D getters with a cage underneath; they don't flash when turned on. These sound quite neutral, balanced across the frequency range, and quite tame for EF91 tubes. Highs are not spiky or sibilant, detailed but not spectacular like other EF91 tubes; at least the highs aren't fatiguing or painful. Instrument separation and resolution are very good (maybe not quite as good as the later CV4014 reviewed above, but it's hard to tell without ABing immediately). Mids and mid-bass are pretty good and don't detract from the rest. Bass isn't too loose and just rumbly enough to be entertaining. Overall, this is a very versatile tube that sounds like a tame crossover between an EF92 and EF91 (which is weird since the CV4014 from '56 I tried and reviewed two weeks ago weren't like that at all and had the treble-centric triangle presentation I hate, maybe factory improvements or better burn-in? Those were the first production years for CV4014, so different batches with different sounds are to be expected). Another pair of tubes I could live with if I had to!
   

   
*Brimar CV4014* (only markings on the tube with "Made in England B.V.A." and indecipherable factory codes), silver glass all around the anodes that hides the internals, identical O-getter tubes, I'd assume from the getter that these are 60's production or later. These are different from anything else I've heard before. The bass is quite extreme and other-worldly. Sure it reflects what's in the music, but it renders the bass in such an interesting and fun way that you just want to keep on listening. Although the bass may or may not be perfectly hi-fi like (debatable), it is still very well controlled and powerful (drives the schiit out of the HE-400 and makes listening to the HD650 an absolute riot!). The treble is very detailed and airy; still a bit spiky on the HifiMAN but perfect on the Senns, pleasant overall (doesn't make my ears bleed), not quite as refined as the CV4014 though. Mids could be a bit more emphasized but don't detract from the global presentation; this gives these tubes a fun U-shaped sound signature. The soundstage seems boundless which pairs very well with the extreme bass that flies in all directions (think fun fat controlled bass like the CV4010/M8100 but in a grown-up version, not perfect but fun). One of the easiest tubes to listen to in the EF91 family in my opinion (and many EF91 tubes are hard to listen to for over 30 minutes...), great listen on the HD650, awesome bass kick. This is one pair I'm sure to burn in a bit.
   

   
*Mullard CV138* KB/D, made in Mitcham in 1952, blue glass, D getter with an open top part (flying copper leads and black rectangle below the getter), no cage between anodes, internals look like the basic Mullard EF91 of the same time period. They sound the same too, that is SS-like and a bit sterile. Detailed and over-emphasized highs that quickly get grating. Recessed mids and thin loose bass. They might improve from a long hard burn in like many basic Mullard EF91s do but knowing the results in advance, I don't feel like it; the sound signature wouldn't change that much anyway.
   

   
*Mullard CV138 6AM6* KB/D, made in Mitcham (no factory code but KB/D) in 1954, blue glass, cage element between anodes, D getter on top of an open part. These are like the (noisy) CV138 I reviewed 2 weeks ago, but they seem to have had an easier life (they may be NOS or close to new). They have an extremely wide soundstage. The bass is loose, slightly punchy, pleasant and unobtrusive. The presentation is basically treble-centric, but not sibilant; mids are a bit recessed. Overall, these tubes are fairly detailed, but not quite as much as the best EF91 tubes. Again, I could probably live with these if necessary, and a bit of burn-in might help.
   
  That's it for now, there's a few more pairs I've tested, I'll post impressions tomorrow. I have to admit these EF91 really have quite a lot of treble. After a whole day of listening to different tubes, my ears feel like they're just about ready to give out, and my head kind of hurts... This is when I miss the 6AK5 love a little.


----------



## markm1

Thanks for all your great info! I'm totally new this...just ordered my first set of cans (Grado 225i) and I'm thinking of buying the Little Dot 1+. I don't know anything about tube rolling yet-as this will be my first exprience w/ a HP amp. Just curious-LD offers:
   

 Replace standard tubes with EF92 - additional $20 USD
 Replace standard tubes with WE408A - additional $50 USD
   
  Would you advise me to stick w/ the tubes it comes with,or are these upgrades worth it IYO.
   
  Much Thanks,
   
  Mark


----------



## markm1

Thanks for all your great info! I'm totally new this...just ordered my first set of cans (Grado 225i) and I'm thinking of buying the Little Dot 1+. I don't know anything about tube rolling yet-as this will be my first exprience w/ a HP amp. Just curious-LD offers:
   

 Replace standard tubes with EF92 - additional $20 USD
 Replace standard tubes with WE408A - additional $50 USD
   
  Would you advise me to stick w/ the tubes it comes with,or are these upgrades worth it IYO.
   
  Much Thanks,
   
  Mark


----------



## Acapella11

Great job reviewing the EF91 tubes Audiofanboy , surely no one expected a bass heavy tube there! Seems like you discovered two nice tubes there. Also nice that you could test with HD650 and HE-400 headphones that adds value. I would to be careful to buy the ones, which are not nicely compatible with HE-400. Cool!
   
  Markm1, I am not familiar with the LD MKI+, but generally it was found that it is cheaper to buy tubes from ebay or a cheap online shop than from David ZheZhe himself.


----------



## django1

Hi all.  I am in need of help.  I just purchased and received a Little Dot Mkii amp.  Delivery was blisteringly fast (2.5 days to Montreal).  However to of the two tubes were broken, one of each.  LD will send replacement tubes, shipping is  "15 to 45 days"
	

	
	
		
		

		
		
	


	




.
   
  I don't have a lot of time for reading threads right now so I was hoping someone could point me to a a fairly cheap set of tubes so that I can try out the amp and see if it works and get a feel for it.  Phones are Grado SR80 and this is my first foray into headphones and amps so I would sure like to hear this thing.  Later when I have more time I will read up on tube rolling .
   
   
  Thanks!


----------



## Audiofanboy

More EF91 goodness
   
*Thorn/AEI CV138* KB/EN, made in 1951 in Sunderland, grey glass, tubes were a few months apart, one had dark grey military markings, the other one off-white, but markings were the same; same construction. These have a fairly wide soundstage, with some audible reverb that makes everything sound like 80s music (like a large room DSP effect). They have a very unusual sound signature, like a laid-back EF91 with unobtrusive bass and mids. The treble lacks the shimmering quality of the best EF91 tubes, and they aren't quite as resolving. Again, like the Brimar, the bass has a rather specific and unusual signature, that -might- work well with jazz. Overall, they should be very forgiving of poor recordings with their weird effects and loose bass.
   
*CV138* KB/FB, made in STC, Footscray in 1951 (?), by Brimar (?), at least that's what google points to. These tubes have silver on the side of the glass (like the Brimar) in different surface coverage. Both tubes have an O-getter, one is medium sized, the other one oversized. These have a pleasant bass, yet another flavor (kind of like the Brimar -again- CV4014, but not as strong) that oscillates between being loose and boomy. Mids are -again, must be a EF91 specificity- unobtrusive. Soundstage is average for an EF91, and highs are tame and rolled-off with just enough detail to feel natural. The frequency response sounds fairly flat for this family of tubes, no U-shaped curve here (no elevated treble, even the bass while fat-sounding isn't even that loose).
   
*MWT CV138 Z77*, from letters one the tubes, these could be from late 1958 or 1959 (?). Not perfectly identical in markings but I suspect markings have been erased on one tube since they look and sound the same. One tube has the MWT logo (circle/spiral thingy with MWT) and aforementioned CV138 and Z77, while the other tube does not have the MWT logo. Both have grey glass and O-getters. The highs on these sounds fairly thin and a bit sibilant, mids are unobtrusive if useful at all. Bass is loose-ish with no particular special flavor. Soundstage is average for an EF91 tubes, instrument separation is good and resolution is OK but nothing exceptional. Treble quickly gets annoying on these tubes, hardly a very pleasant listen (which is what I'd read about MWT tubes).
   
*Z77* mystery tubes, one might have been made in 1950 (not really sure for this one?) has a sticky paper "OSRAM" tag on it, other tube might be from 1952 (?) and has no tag, they were probably made later though. Both have silver glass in slightly different amounts and Z77 written in a square, and a two letter code that I assume is a datecode. They look identical but one flashes when switched on (like the late Mullard CV4014 whereas the other one doesn't, so... let's say these are similar. They sound identical though. These have a fairly wide soundstage and a fairly neutral sound. Bass is actually quite realistic for an EF91 tube and not too loose. Mids are OK, treble dominates the presentation just a little bit without being spiky. Just airy enough to feel detailed; but other EF91 tubes do this even better. Still, I could live with these if I had to. Pretty good tube for jazz recordings with having that ultra shimmering over-detailed treble. Pleasant overall.
   
  So, my conclusion is -how surprising- that the EF91 with the most potential are the CV4014, especially the Mullards, but the Brimars call for more investigating; The old CV138 (the ones with 6AM6 also written) are pretty decent too.


----------



## MIKELAP

Quote: 





django1 said:


> Hi all.  I am in need of help.  I just purchased and received a Little Dot Mkii amp.  Delivery was blisteringly fast (2.5 days to Montreal).  However to of the two tubes were broken, one of each.  LD will send replacement tubes, shipping is  "15 to 45 days"
> 
> 
> 
> ...


 
   
  Go to www.tubebazar.com check out is site this guy lives in the east end of Montreal you probably could go and pick them up did bussiness with this guy once if you go and get them he usually checks the tubes while your there.


----------



## Acapella11

django1,
   
  Which headphones are you using?
   
  Audiofanboy, great! , even more EF91 tubes. Wow, looks like a lot of time and listening.
  As I am going through the text..., one naughty question: do you plan to look at a EF92 tubes as well?  Just because of the CV4015 being a really good tube...


----------



## MIKELAP

Quote: 





django1 said:


> Hi all.  I am in need of help.  I just purchased and received a Little Dot Mkii amp.  Delivery was blisteringly fast (2.5 days to Montreal).  However to of the two tubes were broken, one of each.  LD will send replacement tubes, shipping is  "15 to 45 days"
> 
> 
> 
> ...


 
  it seems those are good upgrades for power tubes 6H30Pi and 6n1p and for drivers russian 6Zh1p, tung-sol 403b sylvania 6ak5w ,mullard 8100 . but stock tubes would be ok check in the book that came with your MK2 the make and number of the tubes are written in there somewhere..


----------



## Audiofanboy

Quote: 





acapella11 said:


> django1,
> 
> 1.) Which tubes are broken? Power or driver tubes?
> 2.) Which headphones are you using?
> ...


 

 Funny you mention EF92 tubes. Actually, now that I have found just how much variety there is in the EF91 (the quality EF91, basically the CV4014), I'm kind of wondering if there might not be some hidden gems in the -special quality- EF92 tubes.
   
  At any rate, having listened to the Brimar CV4014 and old Mullard CV4014 (1958) for a day, I can say that just because they sound so different from the 6AK5/EF95, that makes them interesting to investigate.
   
  So yeah, the hunt continues (not sure I'll find such a stash of cool EF92/CV4015 for that cheap though...).


----------



## Acapella11

Looking forward to it!
   
  Which ones are you going to burn in from those EF91 tubes?


----------



## Acapella11

Django1, OK I was reading your post a bit too quickly. So, from the experience with LD MKIII, I would get pairs of 6N6P-IR and CV4015  Now if they turn out to be too expensive for you, I would take just a pair of 6N6P from between 1970 to 1980 and still a CV4015. If the CV4015 are too pricey, I would get a pair of GE JAN 5654W or 6J1P-EV (Voskhods). At least from the Voskhods, you should get a really cheap pair.
  Hope you get your amp quickly up and running.


----------



## Audiofanboy

Listening (and burning in, even though  they sound mature and probably weren't new) to the '58 Mullard CV4014, which sound quite nice and relaxed on the HE-400 (I need to try those on the HD650 again), tame, detailed and balanced, which is a tall order for EF91s
   
  Definitely gonna spend some more time with the Brimar (seriously otherworldly with the Senns) which I did some extended listening with yesterday already (again, I don't even know if they're new, they sound burnt in as it is, but these *really *picked my curiosity), and the later Mullard CV4014, the O-getter ones that flash (though I know what to expect from what I read but Istill feel like pushing them a little further).
  
  Not all is perfect in the EF91 world, but I do love that soundstage and treble!


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## DutchGFX

Do any of the cool Coke-bottle/Shouldered tubes work on these amps? Seriously considering buying one, and that will be the turning point to get one if they fit!


----------



## Audiofanboy

Normally no, at least not that I know of. But I read a thread somewhere around where people had made "bullplug" adpaters to change the compatible power tube types on these amps. And there might be some cool looking tubes in that family of tubes, whatever it is...


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## mojorisin35

I have these mullard cv4015 on the way
http://www.ebay.com/itm/150981791119?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649

Are these large shield? Small shield? And what is the difference?

Want an amazing deal on hytron 6ak5... 0.99cents...yep and the seller has more.
http://www.ebay.com/itm/380554913502?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649

I also have a pair of tung sol jan 6aj5 on the way
http://www.ebay.com/itm/400329930842?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649

5 slyvania 5654 on the way

And finally
6n6p gold grids 
http://www.ebay.com/itm/350688546177?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649

I received my little do mkiii two days ago 3 days from china! Insanely fast shipping.

Love it and I cannot wait for the tubes to come.

Gary


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## HeatFan12

Great job. Some real nice tubes there. The CBS Hytron 6AK5 is my favorite Grados tube.

Cheers!


Sent from my iPad from Ultrasone Planet using Tapatalk HD


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## sassafras

A little input...
   
  I just got the RCA 5654 Black Plate tubes for my Little Dot Mk II, and wow. Paired with AKG K702s they balance out their tenancy to be a little lighter on the bass, my god it's a perfect match. As well as that they're just a whole lot clearer than the stock tubes. Thanks for the incredibly helpful thread!


----------



## django1

Quote: 





mikelap said:


> Go to www.tubebazar.com check out is site this guy lives in the east end of Montreal you probably could go and pick them up did bussiness with this guy once if you go and get them he usually checks the tubes while your there.


 
   
  Quote: 





mikelap said:


> it seems those are good upgrades for power tubes 6H30Pi and 6n1p and for drivers russian 6Zh1p, tung-sol 403b sylvania 6ak5w ,mullard 8100 . but stock tubes would be ok check in the book that came with your MK2 the make and number of the tubes are written in there somewhere..


 
  Thanks  a lot I will definitely look into this!
  Quote: 





acapella11 said:


> Django1, OK I was reading your post a bit too quickly. So, from the experience with LD MKIII, I would get pairs of 6N6P-IR and CV4015  Now if they turn out to be too expensive for you, I would take just a pair of 6N6P from between 1970 to 1980 and still a CV4015. If the CV4015 are too pricey, I would get a pair of GE JAN 5654W or 6J1P-EV (Voskhods). At least from the Voskhods, you should get a really cheap pair.
> Hope you get your amp quickly up and running.


 
  Thanks for the recommendations.  Part of my wait being over it is making it harder to decide wether I should get some tubes before having heard anything.  I am down to only 7 to 38 day wait (if we are counting weekends...)


----------



## jonmorton

To all,
       I'm new to this game, still waiting for my LD MK III to arrive so please excuse my ignorance.  Why is all the conversation is on rolling the driver tubes and not the power tubes?  or am I missing that in the long thread? 
  Thanks, Jon


----------



## Nirvana Woman

Quote: 





jonmorton said:


> To all,
> I'm new to this game, still waiting for my LD MK III to arrive so please excuse my ignorance.  Why is all the conversation is on rolling the driver tubes and not the power tubes?  or am I missing that in the long thread?
> Thanks, Jon


 

 Because the ones that come stock with the Little Dot are great and the differences between them are much smaller than between drivers.
  Also, it's much more lucrative to roll driver tubes because power tubes tend to be much more expensive.
   
  Also you are not forgiven for your ignorance because there wasn't any .


----------



## Acapella11

Quote: 





jonmorton said:


> To all,
> I'm new to this game, still waiting for my LD MK III to arrive so please excuse my ignorance.  Why is all the conversation is on rolling the driver tubes and not the power tubes?  or am I missing that in the long thread?
> Thanks, Jon


 
 
 There was not much of a discussion, but sadly there was not. Differences between power tubes do exist and I think it is worth to try other power tubes because you might be surprised about synergistic and non-synergistic effects. Just because most people do not roll power tubes doesn't mean you shouldn't.
 Also, there is a reason why LD MK IV has 6H30P and why I am using 6N6P-IR power tubes. Enjoy the tubes and welcome to the club =)


----------



## mojorisin35

It is very interesting that power tubes are starting to be discussed . My 6N6P gold grid arrived from Russia in record time. I rolled them into my ld mkii with the stock driver tubes and two things became immediately clear:
  1. There is more volume available.
  2. There is a considerable improvement in the bass. it is more coherent and clear. with the stock tubes it was a "thub thub" whereas with the 6N6P gold grid's it is a more resolved  "thup thup" and the sub bass is more pronounced. the whole spectrum seems more coherent as well but that may be the newness of the tube rolling for me and not a real artifact of the tubes. your results may vary.
   
  I enjoy listening to a couple of tracks for reference's Jane's Addiction "splash a little water on it" and "Dancing Flute & Drum" from chesky's Dr. Chesky's Sensational, Fantastic, and Simply Amazing Binaural Sound Show!
  with the new tubes the deep bass in "splash a little water on it" was good with the stock tubes however with the new  gold grid's it nearly rumbled my beyerdynamic dt 1350's of my head. when i listened to the dancing flute and drum the overall effect with the gold grid's was even more impact full and impressive than it was with the original tubes.
  If this is a 15% improvement which is often quoted as being the improvement of rolling new power tubes then I am on the edge of my seat for the driver tubes i ordered to arrive! which are supposed to make the most dramatic difference to the SQ.
  as well on that note if anybody has some amperex EF92 6CQ6 they would like to sell at a reasonable price please contact me.
  For those in the know is the jump in price to the eh 6H30pi a 15% jump in sq  from the gold grids or just "different"?
  Gary


----------



## Audiofanboy

About power tubes (on the MK IV SE mind you), I can say they make *much* more of a difference than what I've been reading most of the time. In my case, going from the 6h30pi-EB (an upgrade in and of itself) to the 6n30p-dr (the most expensive and rare alternative), I'd say the jump in performance was closer to 30-40% in sound quality, with *much *better extension in the bass and treble, a huge improvement in resolution and separation, and mostly a true *holographic *(3D) presentation that I just couldn't exactly get with the 6h30pi (enjoyment can't be graded on a linear scale though, but I'd still a 30% improvement in toe-tapping and fun factor just for the power tubes).
   
  Still, if I use just decent driver tubes, a crappy DAC and transport, I don't get that much improvement, it's still garbage in garbage out at every step, including driver to power tubes. But combined with great driver tubes, power tubes make a huge difference in these LD amps. The reason I ended being so picky about driver tubes (and everything in the music chain before that for that matter) is because the power tubes scale very well with other upgrades. My original 6h30pi, while very revealing, just didn't scale with other improvements that well. I used to love the m8100 with the 6h30pi, now they seem a bit too cartoonish (still great and toe-tapping though) with the 6n30p-dr that reveals just how boomy the bass could be and how the treble was quite rolled-off. I suspect it is the same with the 6n6p family of tubes, more transparent power tubes allow for better tuning of the rest of the elements, and end up amounting to much more than the accepted 15%; in my humble opinion of course  .
   
  And as Acapella pointed out a few times, there also the synergy between driver and power tubes that needs to be accounted for, like my example with the 6n30p-dr and m8100...


----------



## Acapella11

> For those in the know is the jump in price to the eh 6H30pi a 15% jump in sq  from the gold grids or just "different"?  Gary


 
   
  It is worth it, I'd say - but because most people here use HD650s and you are using Beyerdynamic DT 1350s, which are supposed to sound cooler and more monitoring, I would be tempted to prioritize a pair of 6N6P-IR, which are also cheaper. If you are then really hooked, get the 6H30P tubes, although you might find in the end that only EF95 tubes will fit (and not the - in my ears - superior CV4015). YMMV as usual.


----------



## thegreat682

Any opinions on 6CB6A tubes?  I just got a deal on 2 GE NOS tubes that was too good to pass up and am curious if anyone had any experiences.  Been using Mullard CV131's for a couple of years now and am thinking it is time for a change...


----------



## Audiofanboy

More EF91 reviews! I just got a package filled exclusively with CV4014 of three different brands. This time I took pictures, which makes it a lot easier to understand tube construction and getter shapes (and shop on ebay thereafter).
   

   
*Mullard CV4014 KB/DC*, made in the Whyteleafe factory (so quite rare) in 1959. Blue glass, rectangle D getter above a cage element, metal cage thingies between the anodes around the tube (seen on the left of the picture behind the writings.
  These have an extremely large 3D soundstage that sounds like a huge cave (not in a bad way) with the opposite of an "in your face" presentation. Bass is loose and dry (not fat), somewhat piano like with a slow decay. treble is airy and non sibilant, a bit elevated, again the instruments are presented in a very spacious way and very well separated (more like far apart). Mids and vocals are fine, not under-emphasized and musical. You could say these tubes have a fairly u-shaped signature but not overly so. For some reason, they aren't as loud as other EF91s, but closer to the my CV4015 in terms of volume.
  Overall, these are great CV4014 tubes (what did you expect?), at least as good as their Mitcham counterparts made in the same time period if not better, and much more spacious. While not quite as detailed as  the CV4015 (hard to dethrone), this is a top tier tube, a laid back, balanced and easy to listen to CV4014, great for alternative and casual styles of music.
   

   
*GEC CV4014 KB/Z*, made in 1960 (MO Valve Company in Hammersmith). Square getter on top of a hollow dark grey box, silver all around the glass. I got 8 of these, all identical, but two have an extra "GEC" sticker like on the picture, I tested two others with only the military markings.
  Now there's an interesting tube. More weighty and dense than the Mullards, guitars have more impact and fell heavier, vocals are fatter (or less thin than most EF91 tubes). Soundstage is large but feels very natural, like the CV4015. There's a typical emphasis on highs but also on mids, which is unusual for EF91s, no U-shaped sound here, more of a swoosh curve. Mids and mid-bass are really liquid (think tubey but in a good way, not harmonic distortion) and have a nice weight to them. Bass is neutral and tight and you hear it when it's in the music, it's not overdone but punchy and well controlled, closer to an EF92 tube. These tubes are quite resolving without feeling over detailed and too bright; the micro details are presented in a discrete but adequate way (you don't hear really loud brassy sounds a foot away from your head like it's the only instrument there, too much "air" kills the music). The vocals really have a fluidity and naturalness that is unusual for EF91s.
  Overall, excellent CV4014, probably one of the best I've heard. Great balance, punchy and meaty "just detailed enough to not be annoying". Great mids for an EF91 and even in general, tight thumpy bass. Only caveat would be that like most EF91/92s, these feel a tad bright, but that's compensated by the liquid midrange!
   

   
*Brimar CV4014 KB/FB* (doesn't say Brimar, but everything goes that direction; previous CV138 KB/FB I'd tested were also Brimar), made in 1957 in STC, Footscray. Folded D getter and silver glass all around, only military markings and 6064 on the tube.
  First impression is the great clarity of this tube when played, details stand out in a natural way in an average size soundstage (read large, this is an EF91). Treble isn't overemphasized yet it is quite pleasant and detailed, mids are pretty good and make vocals sound natural but not brilliant. Bass has that special "Brimar" flavor to it, but in a tighter/drier variety than the Brimar CV4014 with no military markings (see two picture below) I'd tried earlier. I happen to quite enjoy that bass, even though I wouldn't want it everyday.
  Overall, very enjoyable CV4014, not the most detailed but natural, balanced and resolving, with toe-tapping peculiar bass!
   

   
*Brimar CV4014 KB/FB*, can't quite read the date markings, but they should be from 1959. Same characteristics and factory as above, only difference is the large O getter, the rest of the construction is identical.
  These sound almost the same as the folded D getter ones, maybe just a bit tamer, but still balanced, natural and with peculiar bass.
   

   
  These are the original *Brimar CV4014* I'd reviewed, they have the same construction as the two above but with a small O getter. In terms of sound, they are similar but the bass is fatter (not as tight). All Brimar CV4014 tubes are great to try though.
   
  In any case, these 4 pairs of tubes were a cool set of CV4014 to test and give feedback on. But, as usual, I'm sure when I put the CV4015 back in and "recalibrate" my brain and ears, I'll remember why I keep going back to them...
   
  A few more pics of the other tubes I'd reviewed (I'll try and update my previous post too).
   

   
  These are the later "flashing" *Mullard CV4014*, I have years '66 '68 & '72, all identical, see the O getter with no cage like element underneath and the open structure between the anodes.
   

   
  The late 50s Mitcham-made *Mullard CV4014* I'd reviewed, see the cage below the D getter and the metal thing between anodes.
   

   
  The 50's *Mullard CV138* I don't like (that sounds spiky like old basic EF91 tubes with the same flying copper leads with a black rectangle suspended on top).
   

   
  The 50's *Mullard CV138 6AM6* that I do like and could live with, with a much more solid construction than the ones I don't like.
   

   
  And while I'm at it, my *Mullard CV4015* that I keep going back to.
   
  Voila, that's it
   
  (Btw, no I'm not trying to impose a subliminal message to buy "Sony" products lol. I just realized I have the logo on all my pictures... Sorry about that  )


----------



## Acapella11

Thank you for all the EF91 goodness!
   
  The *GEC CV4014 KB/Z *sound interesting. They are made by General Electric? Are they higher gain than the CV4015s?
   
  Great review on these tubes. I think, it gives us all a better insight in the variety of the normally under-represented EF91 family.


----------



## Audiofanboy

It's not General Electric as in GE but some other specific UK company though. I'd found the story on a couple of websites but I forgot the specifics... I think I had to look up the MOV or MO-V company or group to understand the history behind GEC.
   
  Yes, it has higher gain than the CV4015, I need a good quarter less volume on the knob with these (same as most EF91 basically). I does seem to help drive my HE-400 a bit (bass sounds more powerful regardless of amount).
   
  They're easily available on ebay apparently, but expensive... If someone else wants to try them.
   
  I might update my review of these tube a bit though. Upon further testing, one of the two tubes I'd selected kind of just killed itself (happened when I unplugged and replugged headphones, I heard a slight glassy noise and bam no sound in the left channel, I'll be careful with that from now on). And the two other tubes I tried *and* the two GEC labeled ones sound even better than the ones I originally reviewed (more space, deeper bass, no brightness). So, to be continued!


----------



## john57

GE is generally American made and GEC is generally UK made. The GEC are a brighter sound tube but does not quite last as long. I also have the GEC 6080 tube.


----------



## Audiofanboy

Quote: 





john57 said:


> GE is generally American made and GEC is generally UK made. The GEC are a brighter sound tube but does not quite last as long. I also have the GEC 6080 tube.


 

 I think you'd tried and commented on the GEC CV4014 back towards the beginning of the thread right? Which version of these tubes did you try out of curiosity (military date code, GEC label, getter...)?
   
  Here's the link I'd found about GEC btw
   
http://en.wikipedia.org/wiki/General_Electric_Company_plc


----------



## john57

My GEC tubes have the GEC sticker on them and came with the pin savers attached and wrap in a cigar tube in brown paper and in a old white box. My GEC CV4014 KB/Z looks exactly like the pictures above except with the tube at the far left with the up arrow that shows SK mine shows XF. All the other numbers are the same including the 6064 at the bottom. I am trying a new set of headphones and I already have return one set. I post a link when the review is done. I am also enjoying my LD Mk6+


----------



## Audiofanboy

Quote: 





john57 said:


> My GEC tubes have the GEC sticker on them and came with the pin savers attached and wrap in a cigar tube in brown paper and in a old white box. My GEC CV4014 KB/Z looks exactly like the pictures above except with the tube at the far left with the up arrow that shows SK mine shows XF. All the other numbers are the same including the 6064 at the bottom. I am trying a new set of headphones and I already have return one set. I post a link when the review is done. I am also enjoying my LD Mk6+


 

 Thanks for the information, the pair I'm now using is quite similar.
   
  Two tubes with a GEC sticker (the two one the right of the picture), one with a WM code, the other one with XB, stamped by the UK military two months apart from each other, 4 and 6 months before yours, so they should be quite similar. They sound and look fine, but probably aren't NOS.
   
  I swear these sound different from the 5 or 6 SK (4 years older) otherwise exactly identical tubes I also got. The GEC labeled ones are airier with a larger soundstage, sound just a bit less liquid and more balanced, and have bass that is tighter and goes deeper (and less of a mid-bass thump than the "SK" ones). I must say these are even better than the ones I originally reviewed.


----------



## Bee inthe Attic

Hey, I'm new to tubes and have a question:
   
  Are Mullard tubes supposed to have the name "Mullard" printed on them. I bought the Mullard M8100/CV4010 from ebay. Here is a link with a picture.
   
  http://www.ebay.ca/itm/M8100-CV4010-6AK5W-MULLARD-NOS-MATCHED-PAIR-/310282214423?pt=UK_Sound_Vision_Valves_Vacuum_Tubes&hash=item483e42dc17
   
  I don;t know much of anything yet about tubes. So what's the difference between M8100 & CV4010... and are these genuine Mullard if it's not printed on the tube?


----------



## Acapella11

Yes, they are fine. There are different types of basically the same tube. CV is the military name. As with the EF91 tubes above, sound can vary between different years and factories, which can also be reflected in the labeling. I prefer my M8100 with Mullard label (the one that looks like a larger shield) but, I just checked, they aren't offered at the moment on ebay. They look like these (sorry for the long link):
  
 https://www.google.co.uk/search?q=mullard+m8100&hl=en&client=firefox-a&hs=oGk&tbo=u&rls=org.mozilla:en-USfficial&tbm=isch&source=univ&sa=X&ei=Sv4KUZeyJYOd0AX81oGoDg&ved=0CD0QsAQ&biw=1920&bih=906#imgrc=djfpMDwJfO3e4M%3A%3BGR_IHJkfvnH3bM%3Bhttp%253A%252F%252Fi.ebayimg.com%252Ft%252FM8100-MULLARD-6AK5-EF95-E-MATCH-PAIR-NEW-VALVE-TUBE-%252F00%252F%2524%28KGrHqMOKp!E3tTlFCYqBO!04Bethg~~_35.JPG%3Bhttp%253A%252F%252Fwww.ebay.co.uk%252Fitm%252FM8100-MULLARD-6AK5-EF95-E-MATCH-PAIR-NEW-VALVE-TUBE-%252F390429216735%3B300%3B225


----------



## Bee inthe Attic

thanks Acapella


----------



## mab1376

Has anyone tried M8083? I'm looking to try a set out.


----------



## mojorisin35

I just found these:
http://www.ebay.ca/itm/181026020229?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649#ht_1072wt_689

I searched and I couldn't find anybody who has tried original 6F32 TESLA PENTODES EF95, 6AK5
Or if they have they haven't posted there impressions. So has anybody tried them? Any guess as to what they will end up sounding like?

Gary


----------



## Audiofanboy

Quote: 





mab1376 said:


> Has anyone tried M8083? I'm looking to try a set out.


 

 M8083 is the civilian, otherwise identical, version made by Mullard of the military CV4014, many are dual labeled and they are essentially the same quality of tube. Great tubes but not for everyone (bright and treble-centric).
   
  These are reviewed on the first page and I tested some a few pages earlier (Mullard CV4014, a few different versions and years), and many have commented on these throughout the thread, inlcuding Acapella a few pages back.


----------



## mab1376

Ah OK, if they're treble centric, then they're not for me, I guess that would be kind of similar to the M8161?


----------



## Audiofanboy

Quote: 





mab1376 said:


> Ah OK, if they're treble centric, then they're not for me, I guess that would be kind of similar to the M8161?


 

 You could say the CV4015/M8161 are balanced perhaps a tad high-mid centric, but balanced overall.
   
  The GEC CV4014 that we were talking about a few posts back are a great mixture of both, not too bright, heavy controlled bass, and quite euphonic, which I like!


----------



## mab1376

Good to know, maybe I'll give those a shot after doing some reading.
   
  Thanks!
   
  They also need to be on the EF92 setting on the little dot?


----------



## Audiofanboy

Quote: 





mab1376 said:


> Good to know, maybe I'll give those a shot after doing some reading.
> 
> Thanks!
> 
> They also need to be on the EF92 setting on the little dot?


 

 EF91 and EF92 need the EF92 jumper setting


----------



## hallom

hey guys, I don't seem to find 6N6P-IR in matched pairs. Do you think it's an issue if they aren't?


----------



## PanamaRed

Have two pairs of NOS 6AK5 for sale (see signature)

Sorry for the shameless plug


----------



## Acapella11

Quote: 





hallom said:


> hey guys, I don't seem to find 6N6P-IR in matched pairs. Do you think it's an issue if they aren't?


 

 No, I don't think it is an issue. There were also early posts in which people commented that matching could be for some sellers just a way to make some extra money. As long as they are say the same year and the same manufactory, it should be fine.


----------



## pribadi83

Guys need suggest please, i'm newbie in this forum n i already have tube 6n6p did my tube can i use to rolling tube for my litte dot I ? Need respond soon as possible 

Thanks


----------



## Acapella11

What do you mean: "did my tube"?
   
  The LD I is a hybrid amp. Hence, the power tubes (as for the LD MKIII) are substituted by a SS amp unit. So, you cannot use 6N6P tubes on this amp. The tubes you _can_ roll are the driver tubes, which can also be used with the LD MKIII.
   
  Citation from the LD homepage:
   
   
  Quote: 





> Depending on how the switches are configured, three different families of vacuum tubes can be used (EF95, EF92, and 408A).


 
   
  http://www.littledot.net/forum/viewtopic.php?f=9&t=819&sid=bebedb29a5dd956ca59a9aeda2b53d5c


----------



## pribadi83

Thanks Acapella 11 for explain so I just bought a tube that is not useful  , i thought with that's tube i can rolling tube for my LD 1 anyway thats tube i got from ebay just $ 9,99 exclude shipping.


----------



## fruitflavor

majority of my tube collection for MK II
   
  2 of my favourites are GE 6564 and Sylvania.

   
  enough for me and my brother for our life and slowly selling off more valuable ones.


----------



## junkimchi

A elementary question that I can't seem to find the answer to,
   
  What is the difference between the big tubes in the back and the smaller tubes in the front? Are they just a different family? Does one type effect the sound more?


----------



## Acapella11

Quote: 





> A elementary question that I can't seem to find the answer to,
> 
> What is the difference between the big tubes in the back and the smaller tubes in the front? Are they just a different family? Does one type effect the sound more?


 

   
  Hi Junkimchi,
   
  Small front tubes = Driver tubes, think of a preamp function
  Large backside tubes = Power tubes, think of a power amplifier function
   
  Although both influence the sound, the driver tubes are considered to have the larger impact.


----------



## mojorisin35

I just posted a trade post in the for sale forum http://www.head-fi.org/t/649918/little-dot-tubes-mullard-m8083-ef91
I am looking to trade a pair of Mullard M8083 large shield for a pair of Mullard M8161 large shield.
Gary


----------



## gibosi

Quote: 





mojorisin35 said:


> I just found these:
> http://www.ebay.ca/itm/181026020229?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649#ht_1072wt_689
> 
> I searched and I couldn't find anybody who has tried original 6F32 TESLA PENTODES EF95, 6AK5
> ...


 
  I haven't tried them, but for sure, the box looks interesting and the price isn't bad. However, I wonder why the seller didn't post a picture of the tube itself? It sure would be nice to have some idea of the build quality compared to these beauties:
   
  http://www.ebay.ca/itm/130436695928?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649#ht_5393wt_985


----------



## junkimchi

Are these tubes the same? If so, the 2nd link is a great price on the Voskhod 6J1 tubes (same as 6ZH1P)
   
  http://www.ebay.com/itm/2x-Voshkod-6ZH1P-EV-Matched-Pair-Little-Dot-Amp-III-IV-/290613497027?pt=Vintage_Electronics_R2&hash=item43a9ea0cc3
  VS
  http://www.ebay.com/itm/6J1P-EF95-MATCHED-PAIR-tubes-VOSKHOD-Gold-Grid-Year1980-for-Little-Dot-MK-II-3-/130844151721?pt=Vintage_Electronics_R2&hash=item1e76eb4fa9
   
  Such a price difference but I'm guessing its because of supply & demand / international vs Arizona?
   
*EDIT*: Found out that they're the non-extended performance type. Quoted from a post that it's rated at 3,000 hours vs the EV's 5,000 hours. Will report back how they sound are though.


----------



## gibosi

Quote: 





junkimchi said:


> Are these tubes the same? If so, the 2nd link is a great price on the Voskhod 6J1 tubes (same as 6ZH1P)
> 
> http://www.ebay.com/itm/2x-Voshkod-6ZH1P-EV-Matched-Pair-Little-Dot-Amp-III-IV-/290613497027?pt=Vintage_Electronics_R2&hash=item43a9ea0cc3
> VS
> ...


 
  I got my Voskhods here:
   
  2 pc 6J1P-EV (EF95 6F32 6AK7) Gold-Platinum grid! NIB!
   
  http://www.ebay.ca/itm/130436695928?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649#ht_5393wt_893
   
  $15 for a pair including shipping. It took almost 40 days to get to me, but these are wonderful sounding tubes.


----------



## mab1376

My 6N6P-IR tube should be here today finally, can't wait to see how they sound!


----------



## junkimchi

FML I just bought 4 sets of tubes


----------



## gibosi

A number of people have recommended that I try some Tung-Sol tubes in my LD 1+, so I ordered a pair each of JTL 6AK5s and 6AJ5s, 1950's vintage. Upon rolling them into my LD, both pairs exhibited a significant ground hum. It is the kind of hum that is of a constant level independent of the volume setting. Has anyone else experienced this? Has anyone found a credible explanation? And should I assume there is no remedy? Thanks in advance!


----------



## DutchGFX

I have a huge problem! I just received my MKiii, and I hooked it up to my e17 with L7 for line out, I think, and my Q701's have REALLY DISTORTED BASS! It also is distorted on my K240 MKii, and I didn't try my sextetts but I assume it's the same. Why is this, do I need to burn them in to get rid of the distortion? It sounds very boomy, and muddy, not detailed, and does not blend with the music, aka, distorted. Help please  thanks guys


----------



## torara

Hi,

I am new to the little dot amp and just received an MKii. Thanks all of you for great posts that helped me understand a lot about the amp.

I started tuberolling and accidently bought 6n1p-ev instead of 6j1p-ev. Later i found out that the pin out of the 6n1p-ev are the same as the power tube 6n6p, but with different operating parameter. I tried the 6n1p-ev as the power tube for a short while and they work. Soundwise i cannot comment because i have not tried them long enough.

But to make sure im not putting fire on the MKii, have any of you had experience with the 6n1p-ev? Do you know if they are safe as power tube in the MKii. Many thanks...


----------



## Acapella11

Quote: 





dutchgfx said:


> I have a huge problem! I just received my MKiii, and I hooked it up to my e17 with L7 for line out, I think, and my Q701's have REALLY DISTORTED BASS! It also is distorted on my K240 MKii, and I didn't try my sextetts but I assume it's the same. Why is this, do I need to burn them in to get rid of the distortion? It sounds very boomy, and muddy, not detailed, and does not blend with the music, aka, distorted. Help please
> 
> 
> 
> ...


 

 Hi DutchGFX, Is there distorted sound from the headphones used via the L7 and also is there distorted sound when connecting the LD directly to the built in sound card of the computer?
  Just check that to make sure it is the LD itself giving rise to the distortion and not the combination.
  When I received the LD, the sound was muddy and I thought, OMG. It took about 30 hours to come to life. But there was no distortion. If you can pin down that there is also distortion from another source, then I would get in touch with DavidZheZhe.


----------



## DutchGFX

Quote: 





acapella11 said:


> Hi DutchGFX, Is there distorted sound from the headphones used via the L7 and also is there distorted sound when connecting the LD directly to the built in sound card of the computer?
> Just check that to make sure it is the LD itself giving rise to the distortion and not the combination.
> When I received the LD, the sound was muddy and I thought, OMG. It took about 30 hours to come to life. But there was no distortion. If you can pin down that there is also distortion from another source, then I would get in touch with DavidZheZhe.


 

 It doesn't sound any different (terms of distortion) on the Aux out from soundcard. I think its possibly that it just needs to break in? I've had it running about 8 hours prolly. It sounds great on all other frequencies other than the bass. You think it's just break in?


----------



## Acapella11

Quote: 





dutchgfx said:


> It doesn't sound any different (terms of distortion) on the Aux out from soundcard. I think its possibly that it just needs to break in? I've had it running about 8 hours prolly. It sounds great on all other frequencies other than the bass. You think it's just break in?


 
   
  I wouldn't think it is break in. During break in most of tubes mature in terms of sound quality but usually they never distort. Since it also distorts with different headphones, it sounds to me as if one pair of tubes is not good (that is if the distortion is on both channels) or there is a problem with this particular amp.


----------



## mab1376

gibosi said:


> A number of people have recommended that I try some Tung-Sol tubes in my LD 1+, so I ordered a pair each of JTL 6AK5s and 6AJ5s, 1950's vintage. Upon rolling them into my LD, both pairs exhibited a significant ground hum. It is the kind of hum that is of a constant level independent of the volume setting. Has anyone else experienced this? Has anyone found a credible explanation? And should I assume there is no remedy? Thanks in advance!




You may just need to clean the contacts, check eBay for deoxit.


----------



## gibosi

Quote: 





mab1376 said:


> You may just need to clean the contacts, check eBay for deoxit.


 
  Thanks for your suggestion. I have already scrubbed the pins with a soft stainless steel brush and then with a soft brass brush but that didn't make any difference. I have deoxit, but as the brushing didn't help, didn't really think deoxit would either. Will give deoxit a try.... However, I am beginning to think that the tubes are simply defective... bummer.....


----------



## mab1376

gibosi said:


> Thanks for your suggestion. I have already scrubbed the pins with a soft stainless steel brush and then with a soft brass brush but that didn't make any difference. I have deoxit, but as the brushing didn't help, didn't really think deoxit would either. Will give deoxit a try.... However, I am beginning to think that the tubes are simply defective... bummer.....



That's possible, good luck.


----------



## mab1376

gibosi said:


> Thanks for your suggestion. I have already scrubbed the pins with a soft stainless steel brush and then with a soft brass brush but that didn't make any difference. I have deoxit, but as the brushing didn't help, didn't really think deoxit would either. Will give deoxit a try.... However, I am beginning to think that the tubes are simply defective... bummer.....



That's possible, good luck.


----------



## MIKELAP

Quote: 





dutchgfx said:


> I have a huge problem! I just received my MKiii, and I hooked it up to my e17 with L7 for line out, I think, and my Q701's have REALLY DISTORTED BASS! It also is distorted on my K240 MKii, and I didn't try my sextetts but I assume it's the same. Why is this, do I need to burn them in to get rid of the distortion? It sounds very boomy, and muddy, not detailed, and does not blend with the music, aka, distorted. Help please
> 
> 
> 
> ...


 
  Are you sure you have the right settings for the tubes you are using (read manual) and you can also clean the contacts on your tubes with isopropyl alcool 90% proof


----------



## gibosi

Does anyone have any experience with Philips Miniwatt 408As?
   
  http://www.nostubestore.com/2012/08/philips-miniwatt-ts62-6028-408a.html
   
  These are somewhat expensive little buggers but with gold pins they sure look real tempting!


----------



## junkimchi

Would like to share a rather scary occurence.
   
  Today the left channel on my MKII completely went dumb/out. Tried swapping tubes, checked switches and everything but nothing fixed it. Definitely was sure it was the amp since I tried different outputs on my DAC and other headphones.
   
  Somehow it magically came back. I'm hoping that its an isolated occurence but will report back if it happens again.


----------



## john57

One thing you did not mention for the next time is your source connections


----------



## junkimchi

Ok the dead left channel just happened to me again. But then it got fixed again as the amp warmed up a bit. Is this normal? Does this happen to anyone else?


----------



## junkimchi

UPDATE: Turns out it wasn't the amp but actually my D1. Swapped and reseated the OPAMPs and the problem was fixed. I guess it was the superior being's way of telling me I should know the insides of my DAC.


----------



## john57

I knew that your LD was not the issue. I had DAC problems before and my LD's are a bit picky on what DAC source works the best.


----------



## Audiofanboy

Hey John, I have another quick question about your GEC CV4014, if you don't mind.

I just realized that of the two GECs I've been using (pretty much my favorite tube now, right up there with the CV4015), one produces a noticeable flash when switched, and I can't *see* a flash in the second one, but it could be hidden by the silver screening; it's hard to tell. My closest CV4014 made 2 years earlier flashes too. I'm just wondering if my two non-NOS GECs are exactly identical or not, or if say one is dying.

So, could you possibly tell me if yours flash when switched on?

Btw, I do strongly encourage testing those tubes, they are much more punchy and powerful than the EF92 (and 6ak5) and have a great bass thump and liquid mids that work miracles with orthos (HE-500 in my case).

And also, to the person who tried some 6n1p as power tubes on the LD, I really wouldn't do that... Same pinout does not indicate compatibility and in this case, apart from heater voltage and being a double triode there isn't much in common with the 6n6p... Still, I'm curious to know if it even worked and how it sounded.


----------



## john57

Yep, my second set of the GEC tubes the left will flash and the right does not.


----------



## Audiofanboy

Quote: 





john57 said:


> Yep, my second set of the GEC tubes the left will flash and the right does not.


 

 Interesting. So I shouldn't worry about that I guess, as both tubes I use sound the same, and great.
   
  Those are your "XF" date coded tubes right?


----------



## torara

audiofanboy said:


> Hey John, I have another quick question about your GEC CV4014, if you don't mind.
> 
> I just realized that of the two GECs I've been using (pretty much my favorite tube now, right up there with the CV4015), one produces a noticeable flash when switched, and I can't *see* a flash in the second one, but it could be hidden by the silver screening; it's hard to tell. My closest CV4014 made 2 years earlier flashes too. I'm just wondering if my two non-NOS GECs are exactly identical or not, or if say one is dying.
> 
> ...




Hi Audiofanboy,

Yes the 6n1p works as power tube on mkii. Initially i thought that it sounded smooth will slikier highs, clearer presentation than the 6n6p. But after a while of listening the effect was actually 6n1p not having enough power to drive grado 225i. It sounded ok when the volume knob was at around 9 oclock, but when turned to higher volume sound started to distort especially the bass, and the level of loudness did not change much. Like amp is losing power.

Temperature of the mkii when running on 6n1p as power tube after 2 hours remained normal. Anyone may try to see the effect of 6n1p, but i personally do not think it's worth. But if there is anyone who actually willing to try it, please tell us your results and thoughts.

Afterall tube rolling is in deed addictive... Happy rolling....


----------



## Audiofanboy

Quote: 





torara said:


> Hi Audiofanboy,
> 
> Yes the 6n1p works as power tube on mkii. Initially i thought that it sounded smooth will slikier highs, clearer presentation than the 6n6p. But after a while of listening the effect was actually 6n1p not having enough power to drive grado 225i. It sounded ok when the volume knob was at around 9 oclock, but when turned to higher volume sound started to distort especially the bass, and the level of loudness did not change much. Like amp is losing power.
> 
> ...


 

 Fascinating, though I wouldn't try it myself  .
   
  After checking the datasheet for 6n1p (I was thinking 6n23p / 6922 type tubes, used more as a driver tube), it's not that far apart from a 6n6p in its basic electrical characteristics; not exactly replaceable but I understand why it didn't explode or anything.
   
  Still wouldn't try it though.


----------



## Acapella11

Hi Audiofanboy, how do you like the HE-500 on the LD compared to the HE-400?


----------



## DutchGFX

Still having problems with the bass being muddy and boomy! I have narrowed it down to only happening with lower impedence cans. It does not occur with my 600ohm Sextetts. However, it occurs with my Q701's and my 240 MKii. I even switched from stock to RCA 6A5K tubes, still the same crap. Help please


----------



## MIKELAP

Quote: 





dutchgfx said:


> Still having problems with the bass being muddy and boomy! I have narrowed it down to only happening with lower impedence cans. It does not occur with my 600ohm Sextetts. However, it occurs with my Q701's and my 240 MKii. I even switched from stock to RCA 6A5K tubes, still the same crap. Help please


 
  if it helps i use a pair of  denons LA D-5000 which are 25 ohms and they sound good to me, weird!


----------



## DutchGFX

mikelap said:


> if it helps i use a pair of  denons LA D-5000 which are 25 ohms and they sound good to me, weird!




Bass doesn't sound muddy at all? What tubes are you using?


----------



## MIKELAP

Quote: 





dutchgfx said:


> Bass doesn't sound muddy at all? What tubes are you using?


 
  I am listening to some Marcus Miller right now  my  power tubes are 6H30PI GOLD PIN AND the drivers are  VOSHKOD 6ZHIP-EV/6AK5. check JUNKIMCHI thread p.48 she had problems with left channel  and her dac was the problem who knows check it out


----------



## DutchGFX

mikelap said:


> I am listening to some Marcus Miller right now  my  power tubes are 6H30PI GOLD PIN AND the drivers are  VOSHKOD 6ZHIP-EV/6AK5. check JUNKIMCHI thread p.48 she had problems with left channel  and her dac was the problem who knows check it out




It's both channels. It's weird, it's not with my 600 ohms only the lower impedence cans. This is why I don't think it's tube burn in, although it is obvious the 6A5K need burn in, they sound sub par ATM. I don't think it's tube burn in, I honestly, have no idea what the issue is.


----------



## Audiofanboy

For the muddy bass, maybe try to change your gain to a higher or max setting (especially for low impedance cans). I know my mk iv sounds like schiit when on x3 gain with low impedance cans...

Acapella, I actually have to say I really like the HE-500 on the iv se. Close to a sound from heaven when mixed in an optimized chain of gear. It is much easier sounding and natural than the HE-400 despite having higher power needs, and the little dot seems to be powering it alright. It may not be perfect and ideal (otl and orthos? It's not supposed to be a good mix...), but it sounds close to perfect in the highs and mids and in terms of imaging; I don't think I wound get much more from a different amp, and I'd lose the great otl tube liquidity. Only the bass while full detailed and extended could be a bit faster and benefit from an ss power stage I think, but that's probably half because of output power and half because of tube amplification (hard to get perfect ss-like bass with tubes, it's like the only tradeoff really).

Btw, does anyone know if the little dot specs for output power are per channel or total? I.e., 100 mW @ 32 ohms, divided by two or times two...? Actual tested impedance for HE-500 seems to be around 48 ohms, so if the 100 and some mW (300 mW @ 120 ohms, so what ~150 mW @ 48 ohms?) are per channel, it wouldn't be that low to drive basic orthos? (A far cry from the recommended 1W but it's only a few dB difference in the end)


----------



## DutchGFX

It's on 10x ATM. I'm reading that the MKiii sounds bad with low impedence cans. Should I buy an impedence adapter?


----------



## Audiofanboy

Quote: 





dutchgfx said:


> It's on 10x ATM. I'm reading that the MKiii sounds bad with low impedence cans. Should I buy an impedence adapter?


 

 It's not so much that it sounds bad, but that it won't always deliver as much current as necessary. A bad damping factor could also have a negative influence on the headphone frequency response. But you shouldn't be having these sort of problems with 701s, which are hardly considered low impedance all things considered. And many people use LD amps with these AKG headphones.
   
  Impedance adapters probably wouldn't help you much here, besides the fact that it would be easier to get another amp instead.
   
  Are you sure you're not double amping somewhere along the line between the E17 and MK III? If you were, that could cause some audible distortion.
   
  Last thing, imho many 6AK5 tubes while detailed and pleasant don't have what I would consider neutral bass or very precise bass. But, again it shouldn't distort. Maybe you could try some EF92 family of tubes which would give you a different flavor of bass?


----------



## Acapella11

Quote:


> Originally Posted by *MIKELAP* /img/forum/go_quote.gif
> if it helps i use a pair of  denons LA D-5000 which are 25 ohms and they sound good to me, weird! 
  
 LD MKIII + Denon AH-D5000
  
 I have heard the Denon AD-H5000 with the LD MK III with 6H30P Gold Grids and Voskhods 6Zh1P-EV with a Violectric V800 DAC and to say the least, it sounds really good. It is a great combination with a nice tight bass and treble sparkle. You could get addicted from that. After comparing with the HE-500, I find the great non-fatiguing treble with the HE-500s more to my liking though. The gain setting was 1. This is sufficient for the Denons because their sensitivity is really good with 106 dB (at 25 ohm) unlike 89 dB (around 38 ohm) for the HE-500s, which makes them a tougher partner to drive.
 Also, consider your overall tube setup to use 6H30+nice EF95 or _CV4015_, or 6N6P-IR + EF95 or_ CV4015_ for a more spatial representation.
  
  
 LD MKIII + AKG Q701
  
 As I am writing, I am listening to the LD MKIII (6H30P-EV, CV4015, Audiolab M-DAC /w Optimal Transient filter, which is a "gentle" one) and it does sound good. Quite hard hitting bass, nice instrument separation, good clarity on the harder side with the 6H30 tubes. My gain is set to 10.  Now I stuck the 6N6P-IRs in and that makes the sound rounder and kicks the shyte out of the cans too. I actually didn't use exactly this chain since I got all the components in and to be fair I do like it - recommended. Now, I think K701s are a little bit more difficult to drive compared to Q701, but the LD should be good still.
  
  
 LD and HE-500
 Quote:


> Acapella, I actually have to say* I really like the HE-500 on the iv se*. Close to a sound from heaven *when mixed in an optimized chain of gear. *It is much easier sounding and natural than the HE-400 despite having higher power needs, and the *little dot seems to be powering it alright*. It may not be perfect and ideal (otl and orthos? It's not supposed to be a good mix...), but it sounds close to perfect in the highs and mids and in terms of imaging; I don't think I wound get much more from a different amp, and I'd lose the great otl tube liquidity. Only the bass while full detailed and extended could be a bit faster and benefit from an ss power stage I think, but that's probably half because of output power and half because of tube amplification (hard to get perfect ss-like bass with tubes, it's like the only tradeoff really). 
  
 I totally agree. I have the opportunity to compare the MKIII with the SPL Auditor (400mW, SS, excellent quality components). This amp is also for my AKG K501 phones. Interestingly, the sound signature with 6N6P-IR and CV4015 is very close to the Auditor. I won't comment on the sound differences much, because I need to do some more listening but the LD still keeps up well. The Auditor has better imaging, sounds a bit more dynamic and transparent. There is a better level in terms of SQ for me but the LD is not far behind.
  
 One of the conclusions for me, as now for you as well, is that an upgraded LD MKIII in a good chain does work with the HE-500s. Although, as they are low efficient planars, you cannot achieve all the dynamics that they can deliver. I guess, the HE-500 do scale up quite well.
  
 Compairing the Audiolab M-DAC in with Beresford Caiman, the Caiman still is an attractive DAC (stage, instrument separation, detail, attack), but the Audiolab has a more natural flow in its signature and you can vary digital filters as well. My point here is that the M-DAC in combination allows me the use of 6H30P-EV + CV4015 tubes without listening fatigue. And again I come back to the benefits of these tubes and know why you got yourself the DRs. Still put the 6N6P-IRs back for now .


----------



## DutchGFX

Yeah the Q's sound fine right out of the E17. I was thinking it was double amping too, but it does not have this issue on the Sextetts. Is it possible the sextetts just have so much less bass I don't notice it? I don't really want to return it, cause then I'm out another 40 in shipping, so that'd be 90 bucks. Plus, idk what other amp I would buy in that price range.

I could sell it on here, so shipping would be cheaper. I really don't know what to do. This is such an odd problem. It has the same problem when I plug directly into my laptop. This is so annoying and obscure, I really apreciate al your help so far 

*EDIT:* Narrowed it down to GAIN. When the gain is >3 on the LD, it sounds bad. I don't know if this is solely cause its louder, or if its S/N ration is going down, due to amping crappy signal from my E17. Also, changing the gain on the E17 has 10x the bad effects as when I change it on the LD. I have a feeling this L7 dock is bogus, and its not line out. When I have gain at 12db on the E17 alone, no LD, it sounds fine. So I think its actually not line out, as I can still adjust volume and gain with E17.

*EDIT AGAIN!* So it is volume. I tested on 10x Gain with my 250 ohm 880's, and my Sextetts. Also, I even tried 3x gain with +6/+12db from the E17, sounds fine on those 2 cans. However, the problem persists with my Q701. I think I might need an impedence transformer, would that fix the issues?


----------



## mab1376

anyone tried these tubes?
   
  http://www.aloaudio.com/siemens-6ak5-w


----------



## mojorisin35

gibosi said:


> I haven't tried them, but for sure, the box looks interesting and the price isn't bad. However, I wonder why the seller didn't post a picture of the tube itself? It sure would be nice to have some idea of the build quality compared to these beauties:
> 
> http://www.ebay.ca/itm/130436695928?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649#ht_5393wt_985






I just rolled my factory matched pair of Tesla 6f32 into my LD MKIII and my initial impressions are WOW! 
Without even being completely being burnt in they are something special.



The most outstanding quality thus far is the Crystal clear sparkling highs, which present themselves with great extension without any hints of sibilance. 
with these I find the Highs much more pleasant than the Tung sol 6AJ5 and the the highs of the Tesla's are way more resolved than the Voshkod 6ZH1P-EV.



I find the mids are very neutral they remind me of the Tung Sol 6aj5 mids perhaps a little less warm.
However they are nowhere near the luscious mids of the mullard ef92’s so if you find the mullards to colored you might want to look into a pair of these. 

The Bass is deep accurate and clear and very close to the Bass of the Voshkod 6ZH1P-EV perhaps a touch more authoritative...

The soundstage is as wide and deep as any I have heard however it has the added dimensionality of height. I had not been able to discern this before with other tubes but with these tubes there it was. 
Highly recommended! I cannot wait to see what they develop into after some burn in.



i will update as the tubes age

Gary
current tubes i own
Sylavania JAN5654
Tung Sol 6AJ5
Voshkod 6ZH1P-EV
Mullard EF92

Power 
6n6p gold grid

on the way
Mullard M8083 
Mullard M8161
Mullard M8100
CBS / HYTRON 6AK5W


----------



## gibosi

Quote: 





mojorisin35 said:


> I just rolled my factory matched pair of Tesla 6f32 into my LD MKIII and my initial impressions are WOW!
> Without even being completely being burnt in they are something special.
> 
> 
> ...


 
   
  This is great news! I have two pairs of Teslas on their way to me. One pair in that very funky box from eBay and another pair from Tubes-Store:
   
  http://tubes-store.com/product_info.php?manufacturers_id=12&products_id=608
   
  The tube graphics on the pair from Tubes-Store are different from the ones on eBay and the price was reasonable, at $4.00 a tube, so I thought I would try them too. Unfortunately,they have a minimum order of $20, including shipping, so I had to buy 3 tubes. I will be rolling them into an LD 1+. And after reading your initial impressions I am really looking forward to their arrival.


----------



## gibosi

Quote: 





mab1376 said:


> anyone tried these tubes?
> 
> http://www.aloaudio.com/siemens-6ak5-w


 
   
  I have never seen these before, but they might be promising. My first concern was that they might be rebadged tubes, for example, Philips or GE, made in Siemen's factories after WWII. But searching Siemen's history, I can't find any indication that they sold their naming rights to another tube company, or bought another company, or entered into some sort of joint manufacturing agreement. So perhaps they were actually designed and manufactured by Siemen's. And if so, they may well have their own unique sound. I hope someone gets a pair of these soon and comes back here to give us their impressions.


----------



## gibosi

Quote: 





gibosi said:


> A number of people have recommended that I try some Tung-Sol tubes in my LD 1+, so I ordered a pair each of JTL 6AK5s and 6AJ5s, 1950's vintage. Upon rolling them into my LD, both pairs exhibited a significant ground hum. It is the kind of hum that is of a constant level independent of the volume setting. Has anyone else experienced this? Has anyone found a credible explanation? And should I assume there is no remedy? Thanks in advance!


 
   
  I tried cleaning the pins thoroughly, but heard absolutely no improvement and had given up. However, at a recent Head-Fi meetup, I met a guy with years of experience with tube amps. When I told him about these tubes, he suggested that I simply burn them in for several hours. And it worked! I ended up burning in the Tung-Sol 6AK5s for a total of 8 hours! But they are now very quiet and sounding exquisite! Thought I would pass this information along on the chance that it might help someone else.
   
  Cheers!


----------



## gibosi

Quote: 





mab1376 said:


> anyone tried these tubes?
> 
> http://www.aloaudio.com/siemens-6ak5-w


 
  It appears Alo is asking $29 for one tube? Well... If you would like to give them a try, they can be had on eBay for a bit more than $17 for a pair including shipping ($7.75 each plus $1.64 for shipping):
   
  http://www.ebay.com/itm/300812726403?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649


----------



## thegreat682

I bought these little guys a few weeks ago and after 50+hrs of burn in they have replaced Mullard CV131s as my default "go-to" tube.  I have not read much of anything about rolling with the 6CB6A series of tubes and they can currently be had VERY cheap.  I received both of these for $5 shipped.  I'd like to know more information about them as I have not found any information on dating GE tubes, and I very quickly fell in love with their sound signature.  I'd highly recommend giving these a shot.  They also light up brighter than any tube I currently have which sure does look pretty


----------



## Acapella11

Quote: 





thegreat682 said:


> I bought these little guys a few weeks ago and after 50+hrs of burn in they have replaced Mullard CV131s as my default "go-to" tube.


 
  Would you state why? What is the tube's sound signature?


----------



## thegreat682

Quote: 





acapella11 said:


> Would you state why? What is the tube's sound signature?


 
  Apologies.  I will try my best as I have never attempted anything like this before...
   
  Compared to CV131s, the treble presented is much cleaner and detailed without much sibilance.  Vocals really shine through.  Bass is present and not muddy or overpowering.  I get a wider sense of space as well.  It has been really fun listening to the tubes mature and hearing new details in some of my favorite albums!
   
  Edit:  I should really emphasize more how huge the space is presented in these, sounding similar the center of an auditorium.  I listen to a lot of live rock and blues and feel the 6CB6A tubes have added a ton of life to many of my favorite shows.


----------



## gibosi

Quote: 





thegreat682 said:


> Apologies.  I will try my best as I have never attempted anything like this before...
> 
> Compared to CV131s, the treble presented is much cleaner and detailed without much sibilance.  Vocals really shine through.  Bass is present and not muddy or overpowering.  I get a wider sense of space as well.  It has been really fun listening to the tubes mature and hearing new details in some of my favorite albums!
> 
> Edit:  I should really emphasize more how huge the space is presented in these, sounding similar the center of an auditorium.  I listen to a lot of live rock and blues and feel the 6CB6A tubes have added a ton of life to many of my favorite shows.


 
  Well, as you noted, these are pretty cheap, so I just ordered a pair of Tung-Sols and a pair of Sylvanias and am looking forward to auditioning them.


----------



## mojorisin35

Quote: 





thegreat682 said:


> I bought these little guys a few weeks ago and after 50+hrs of burn in they have replaced Mullard CV131s as my default "go-to" tube.  I have not read much of anything about rolling with the 6CB6A series of tubes and they can currently be had VERY cheap.  I received both of these for $5 shipped.  I'd like to know more information about them as I have not found any information on dating GE tubes, and I very quickly fell in love with their sound signature.  I'd highly recommend giving these a shot.  They also light up brighter than any tube I currently have which sure does look pretty


 
  Very interesting! Yet another family of tubes to look at. I have a pair of ge m8083 mullard rebrands. Thanks for bringing these to my attention


----------



## gibosi

Re: 6CB6A tubes
   
  These are also known as EF190.
   
  http://www.radiomuseum.org/tubes/tube_6cb6a.html
   
  Searching for EF190, you will find the old Soviet equivalents, 6J38P,and the Soviet military version, 6J38P-EV. These look pretty nice....


----------



## Acapella11

Quote: 





thegreat682 said:


> Apologies.  I will try my best as I have never attempted anything like this before...
> 
> Compared to CV131s, the treble presented is much cleaner and detailed without much sibilance.  Vocals really shine through.  Bass is present and not muddy or overpowering.  I get a wider sense of space as well.  It has been really fun listening to the tubes mature and hearing new details in some of my favorite albums!
> 
> Edit:  I should really emphasize more how huge the space is presented in these, sounding similar the center of an auditorium.  I listen to a lot of live rock and blues and feel the 6CB6A tubes have added a ton of life to many of my favorite shows.


 

 Thanks for the impressions. If I would roll tubes these days, I would surely be tempted =)


----------



## gibosi

Quote: 





mojorisin35 said:


> I just rolled my factory matched pair of Tesla 6f32 into my LD MKIII and my initial impressions are WOW!
> Without even being completely being burnt in they are something special.
> 
> 
> ...


 
   
  My factory-matched Teslas in the funky box arrived yesterday. I haven't spent a lot of time with them, but doing some quick A/B-ing between these and the Voshkods, they sound very similar. Perhaps after they have burnt in and I have spent more time with them, I will be able to better discern how they differ. Except for the red paint, they look very similar to mojorisin35's. I can't quite make out what is written in red paint, but it looks like 3.? - perhaps this is a measurement used to certify that they are matched?
   
   

   
   
  Yesterday, my Siemens 6AK5Ws arrived too. (It was a very good day!   I can easily distinguish female vocals, for example Norah Jones, from the Mullards and the Voshkods. They are not as lush as the Mullards and not quite as bright as the Voshkods. All in all the vocals seem very smooth to me and I quite like them.


----------



## Audiofanboy

Quote: 





thegreat682 said:


> I bought these little guys a few weeks ago and after 50+hrs of burn in they have replaced Mullard CV131s as my default "go-to" tube.  I have not read much of anything about rolling with the 6CB6A series of tubes and they can currently be had VERY cheap.  I received both of these for $5 shipped.  I'd like to know more information about them as I have not found any information on dating GE tubes, and I very quickly fell in love with their sound signature.  I'd highly recommend giving these a shot.  They also light up brighter than any tube I currently have which sure does look pretty


 

 Nice, more tube families to try on my LD and less cash in my wallet... I obviously have to try this though, it just sounds too interesting to pass. That and the fact I'm looking for more high gain EF91-like tubes.
   
  Could you possibly tell me who/where you bought these from (if you bought them on ebay and there's more from that seller)?


----------



## thegreat682

Quote: 





audiofanboy said:


> Could you possibly tell me who/where you bought these from (if you bought them on ebay and there's more from that seller)?


 
   
  Gladly 
	

	
	
		
		

		
		
	


	




.  I bought my tubes on ebay from desireme1979.  I just looked at his store and he currently does not have any more GE tubes, but does have a few Raytheon 6CB6A tubes.
   
  Also, there is an interesting thread http://www.head-fi.org/t/572279/different-tubes-for-little-dot-mkiii-must-see-for-mk3-owners here where a user lists several different types tubes that he claims work in the MKIII with the EF92 jumper


----------



## Audiofanboy

Quote: 





thegreat682 said:


> Gladly
> 
> 
> 
> ...


 
  Thanks for the tip! That'll definitely keep me awake for a few nights...
   
  After a bit of fact checking about all those tubes, and others I've read about, I decided to try a pair of Brimar 6BH6 I had lying around, since they seemed to have a compatible pin out and were similar to the 6BJ6 mentioned in that thread (150 mA current draw, so less than a 6AK5 and half of a EF91).
   
  It didn't explode, actually it worked pretty well for a mystery tube. I was surprised by how airy and detailed it sounded, but the bass was crappy and it wasn't as musical as my favorite tubes. At least, I don't think I heard distortion but I could be wrong.
   
  Ok, I'm convinced. I'll be rolling new families of tubes in my LD amp and reporting back. The families I'm most interested in are all the high current draw high gain ones, >300 mA. I see the guy in the other thread tested two or three tubes that draw 400 or 450 mA, I'd be curious to see if the amp can sustain that without massively overheating (as it is feels quite warm with EF91 in the winter as it is), and how it sounds.


----------



## Acapella11

Quote:  





> The families I'm most interested in are all the high current draw high gain ones, >300 mA. I see the guy in the other thread tested two or three tubes that draw 400 or 450 mA, I'd be curious to see if the amp can sustain that without massively overheating (as it is feels quite warm with EF91 in the winter as it is), and how it sounds.


 
   
  I know what you are thinking and it is a great idea. Good luck! God knows what the MKIII / IV might drive after these experiments...


----------



## gibosi

Quote: 





audiofanboy said:


> Nice, more tube families to try on my LD and less cash in my wallet... I obviously have to try this though, it just sounds too interesting to pass. That and the fact I'm looking for more high gain EF91-like tubes.
> 
> Could you possibly tell me who/where you bought these from (if you bought them on ebay and there's more from that seller)?


 
   
  Today the Sylvania 6CB6As arrived:
   
   

   
  I did a quick A/B with my GEC CV4014s and yes, these Sylvanias seem to have the same level of gain as the EF91s. I think the GEC's bass is a bit bigger, but not by much, and the GEC's upper midrange is a bit brighter. However, I find these Sylvanias very balanced and musical. I think it is great to finally have a good selection of cheap tubes available that can be used with the EF91/2 settings.
   
  Oh.. The blue line you see on the tube is some kind of reflection. It is not on the tube itself.


----------



## Audiofanboy

Quote: 





gibosi said:


> Today the Sylvania 6CB6As arrived:
> 
> 
> 
> ...


 

 Great, this is getting interesting! So, would you say these sound somewhat like a higher gain CV4015 (balanced and musical, but maybe a bit more punchy)? Out of curiosity, did you order any other brands too? Any date code on these, just to get a feeling of what time period they were made in?
   
  Acapella, yes you understood what I'm trying to do here. I will make my MK IV drive orthos properly, whether it wants to or not! Well, at least I'll try... Since there is no doubt my CV4015 just aren't giving enough power to the power tubes in my amp to drive HE-500 correctly (I get all the nice OTL perks, holographic soundstage, dynamics and liquidity, but I can tell the bass is just not keeping up like it was even on the HD650 or even the HE-400). Whereas, my GEC CV4014 seem to be *just* enough to drive the HE-500 to maybe 80-90% of what it can do, and still has all the OTL goodness.
   
  Anyway, interesting endeavors. I feel a whole dimension just opened before me.


----------



## MIKELAP

Quote: 





audiofanboy said:


> Thanks for the tip! That'll definitely keep me awake for a few nights...
> 
> After a bit of fact checking about all those tubes, and others I've read about, I decided to try a pair of Brimar 6BH6 I had lying around, since they seemed to have a compatible pin out and were similar to the 6BJ6 mentioned in that thread (150 mA current draw, so less than a 6AK5 and half of a EF91).
> 
> ...


 
  I bought this guys amp last year and if he tested those tubes,the  amp still runs good.didnt damage anything.


----------



## Acapella11

Quote: 





audiofanboy said:


> Great, this is getting interesting! So, would you say these sound somewhat like a higher gain CV4015 (balanced and musical, but maybe a bit more punchy)? Out of curiosity, did you order any other brands too? Any date code on these, just to get a feeling of what time period they were made in?
> 
> Acapella, yes you understood what I'm trying to do here. I will make my MK IV drive orthos properly, whether it wants to or not! Well, at least I'll try... Since there is no doubt my CV4015 just aren't giving enough power to the power tubes in my amp to drive HE-500 correctly (I get all the nice OTL perks, holographic soundstage, dynamics and liquidity, but I can tell the bass is just not keeping up like it was even on the HD650 or even the HE-400). Whereas, my GEC CV4014 seem to be *just* enough to drive the HE-500 to maybe 80-90% of what it can do, and still has all the OTL goodness.
> 
> Anyway, interesting endeavors. I feel a whole dimension just opened before me.


 
   
  May the (power) juice be with us 
   
  Might be tempted to try also one of this 6CB6A family of tubes.


----------



## gibosi

Quote: 





audiofanboy said:


> Great, this is getting interesting! So, would you say these sound somewhat like a higher gain CV4015 (balanced and musical, but maybe a bit more punchy)? Out of curiosity, did you order any other brands too? Any date code on these, just to get a feeling of what time period they were made in?
> 
> Acapella, yes you understood what I'm trying to do here. I will make my MK IV drive orthos properly, whether it wants to or not! Well, at least I'll try... Since there is no doubt my CV4015 just aren't giving enough power to the power tubes in my amp to drive HE-500 correctly (I get all the nice OTL perks, holographic soundstage, dynamics and liquidity, but I can tell the bass is just not keeping up like it was even on the HD650 or even the HE-400). Whereas, my GEC CV4014 seem to be *just* enough to drive the HE-500 to maybe 80-90% of what it can do, and still has all the OTL goodness.
> 
> Anyway, interesting endeavors. I feel a whole dimension just opened before me.


 
   
  Unfortunately, I don't see any date code on these tubes and the seller didn't provide any info either. I have also ordered a pair of Tung-Sols and the Russian military equivalents, 6J38P-EV (1978), but they haven't arrived yet.
   
  I haven't had a chance to directly compare them to my Mullard CV4015s. Going only by memory, I would guess these Sylvanias to be more similar to the Mullards than the GECs. When I get time I will try to AB them.


----------



## Audiofanboy

Quote: 





gibosi said:


> Unfortunately, I don't see any date code on these tubes and the seller didn't provide any info either. I have also ordered a pair of Tung-Sols and the Russian military equivalents, 6J38P-EV (1978), but they haven't arrived yet.
> 
> I haven't had a chance to directly compare them to my Mullard CV4015s. Going only by memory, I would guess these Sylvanias to be more similar to the Mullards than the GECs. When I get time I will try to AB them.


 

 6J38P-EV aren't the same as 6CB6 from what I've read (0.19A vs 0.3A), but closer to a 6BH6 tube (0.15A) like the one I just tried, yet still different, even visually. I keep seeing some confusion on google and ebay between the 6CB6A, EF190 and E90F 6BH6 types, mainly on all the Russian ads. I think I'll hold off on the Russian "equivalents" for the 6CB6A tube for now (there are other Russian tube families I can try first and that are clearly identified).
   
  Anyway, I'm still curious to hear how it sounds (and if it works as I can't find the pin out for these tubes).


----------



## gibosi

Quote: 





audiofanboy said:


> 6J38P-EV aren't the same as 6CB6 from what I've read (0.19A vs 0.3A), but closer to a 6BH6 tube (0.15A) like the one I just tried, yet still different, even visually. I keep seeing some confusion on google and ebay between the 6CB6A, EF190 and E90F 6BH6 types, mainly on all the Russian ads. I think I'll hold off on the Russian "equivalents" for the 6CB6A tube for now (there are other Russian tube families I can try first and that are clearly identified).
> 
> Anyway, I'm still curious to hear how it sounds (and if it works as I can't find the pin out for these tubes).


 
   
  Oh... I so was looking forward to these Russian military tubes!  But from your experience, it seems that I will soon receive some worthless tubes....    And I have learned a valuable lesson.  When I am dealing with relatively unknown tubes, I should not simply trust the posting language, I need to check specs as well. If you do find some Russian tube families that work well, I trust you will let us know. 
   
  About the time period for these Sylvanias. On the box, the address for Sylvania is 1740 Broadway, New York 19, N.Y. Postal zones were replaced by the zip system in 1963, but of course, this did not happen overnight. So I would hazard a guess that these tubes were made before 1970.


----------



## Audiofanboy

Quote: 





gibosi said:


> Oh... I so was looking forward to these Russian military tubes!  But from your experience, it seems that I will soon receive some worthless tubes....    And I have learned a valuable lesson.  When I am dealing with relatively unknown tubes, I should not simply trust the posting language, I need to check specs as well. If you do find some Russian tube families that work well, I trust you will let us know.
> 
> About the time period for these Sylvanias. On the box, the address for Sylvania is 1740 Broadway, New York 19, N.Y. Postal zones were replaced by the zip system in 1963, but of course, this did not happen overnight. So I would hazard a guess that these tubes were made before 1970.


 

 I found a datasheet for these : http://www.prekyba.biz/datasheets/download?f=6J38P.pdf
   
  These actually seem to be closer to a 6AK5 tube in terms of specs : http://frank.pocnet.net/sheets/049/6/6AK5.pdf
   
  With my limited (non-existent) Russian skills, I'm seeing compatible pin-out with a 6AK5 or most other tubes I've been investigating for the last few days (if I consider the c1, c2 and c3 to be the same as grid 1, 2 and 3 in English, and so on for the other letters for the heater, cathode and anode), though there is still a mystery sign on pin 7 which could/should be the shield, so OK. 6.3V 190mA, pentode, similar specs compared to 6AK5, slightly different useful frequency band but I can't read what it's technically used for though. The plate also looks closer to a 6AK5-ish one.Any Russian speakers here?
   
  Well, if it explodes when you try it, do tell us... I can't say I'm quite confident on this one.
   
  Thanks for the datecode estimate!


----------



## gibosi

Quote: 





audiofanboy said:


> I found a datasheet for these : http://www.prekyba.biz/datasheets/download?f=6J38P.pdf
> 
> These actually seem to be closer to a 6AK5 tube in terms of specs : http://frank.pocnet.net/sheets/049/6/6AK5.pdf
> 
> ...


 
   
  This is interesting! The 6AK5 is 175ma, the Russion tube is 190ma and the EF92 is 200ma. It is my understanding that the EF92 has the same pin out as a 6AK5, but with 200ma instead of 175ma. This suggests that I might try both ways, with the EF91/92 jumpers on and off. Thanks for digging into this!


----------



## Audiofanboy

Quote: 





gibosi said:


> This is interesting! The 6AK5 is 175ma, the Russion tube is 190ma and the EF92 is 200ma. It is my understanding that the EF92 has the same pin out as a 6AK5, but with 200ma instead of 175ma. This suggests that I might try both ways, with the EF91/92 jumpers on and off. Thanks for digging into this!


 

 You know, this is actually something I was wondering about earlier. What is the actual difference between the EF95 and EF92 setting? Pin out (doubtful), plate voltage? This isn't exactly trivial as apparently, using EF92/91 with wrong setting makes sound like schiit (as in not enough power and flat), but using EF95 with the wrong setting seems to be more problematic (too much voltage on *something* in the tube?).
   
  Again, don't take my word for it considering compatibility, a few more informed opinions wouldn't be too much here.


----------



## gibosi

Quote: 





audiofanboy said:


> You know, this is actually something I was wondering about earlier. What is the actual difference between the EF95 and EF92 setting? Pin out (doubtful), plate voltage? This isn't exactly trivial as apparently, using EF92/91 with wrong setting makes sound like schiit (as in not enough power and flat), but using EF95 with the wrong setting seems to be more problematic (too much voltage on *something* in the tube?).
> 
> Again, don't take my word for it considering compatibility, a few more informed opinions wouldn't be too much here.


 
   
  My source is a posting by "Dept_of_Alchemy" in the Little Dot 1+ tube rolling forum:
   
  http://www.head-fi.org/t/364043/little-dot-i-tube-rolling   (See post number 3 on page 1)
   
  ~~~~~
   
   
  The EF92 and 5654 have the same pin out the difference is that the EF92 draws 200mA of plate current while the 5654 draws 175mA. This gives the EF92 a little more gain and (in theory) a more linear top-end response.
   
  - DoA


----------



## Audiofanboy

Quote: 





gibosi said:


> My source is a posting by "Dept_of_Alchemy" in the Little Dot 1+ tube rolling forum:
> 
> http://www.head-fi.org/t/364043/little-dot-i-tube-rolling   (See post number 3 on page 1)
> 
> ...


 

 Yup, EF92 (and even more so EF91) has more gain, and I understand there is a pretty linear correlation between anode current draw and essentially "power" output in the amp , but that still leaves me wondering what the jumper settings actually change. When you look at the specs for many of these tubes, few settings actually vary a lot, and that is especially true between EF92 and EF95 (despite having totally different constructions), yet they won't work properly on this amp with the wrong jumper setting, just wondering why.
   
  Take the 6BH6 I tested for example. It should be very similar to the EF95 and your (future) 6j38p-ev. But I tried it on the EF92 setting and it seemed to work fine, despite having a 150 mA current draw, which is less than a 6AK5/EF95 tube.
   
  I've gone on a binge ebay tube buying, I've ordered 35-40 (decently priced) tubes already, and I'm not quite done yet. You can expect some major feedback in the next couple of weeks! My wallet is weeping, but oh well it's not that much money compared to an amp or pair of orthos (although it amounts to a lot over a few months).


----------



## gibosi

Quote: 





audiofanboy said:


> Yup, EF92 (and even more so EF91) has more gain, and I understand there is a pretty linear correlation between anode current draw and essentially "power" output in the amp , but that still leaves me wondering what the jumper settings actually change. When you look at the specs for many of these tubes, few settings actually vary a lot, and that is especially true between EF92 and EF95 (despite having totally different constructions), yet they won't work properly on this amp with the wrong jumper setting, just wondering why.
> 
> Take the 6BH6 I tested for example. It should be very similar to the EF95 and your (future) 6j38p-ev. But I tried it on the EF92 setting and it seemed to work fine, despite having a 150 mA current draw, which is less than a 6AK5/EF95 tube.
> 
> I've gone on a binge ebay tube buying, I've ordered 35-40 (decently priced) tubes already, and I'm not quite done yet. You can expect some major feedback in the next couple of weeks! My wallet is weeping, but oh well it's not that much money compared to an amp or pair of orthos (although it amounts to a lot over a few months).


 
   
  35-40 individual tubes?  Or 35-40 pairs? I have about 25 pairs of tubes and I sometimes think I have gone way overboard! ahaha.... And as I have an LD 1+, 7 of those pairs are 408As. Anyway, I am really looking forward to learning what you end up buying and reading your impressions. And of course, when I finally get those soviet tubes, I will report back.
   
  Also, I have been trying to A/B my CV4015s with these Sylvanias and to my ears they sound very similar. That said, it is pretty difficult to match volume while switching back and forth. Further my headphones are nothing to brag about. But again, I am quite surprised how similar they sound given their construction is so different.
   
  Great fun!


----------



## Audiofanboy

Quote: 





gibosi said:


> 35-40 individual tubes?  Or 35-40 pairs? I have about 25 pairs of tubes and I sometimes think I have gone way overboard! ahaha.... And as I have an LD 1+, 7 of those pairs are 408As. Anyway, I am really looking forward to learning what you end up buying and reading your impressions. And of course, when I finally get those soviet tubes, I will report back.
> 
> Also, I have been trying to A/B my CV4015s with these Sylvanias and to my ears they sound very similar. That said, it is pretty difficult to match volume while switching back and forth. Further my headphones are nothing to brag about. But again, I am quite surprised how similar they sound given their construction is so different.
> 
> Great fun!


 

 Individual tubes, which is a lot already... Bear in mind most of these are the same types of tubes, so it's only like 5 or 6 pairs I might end up using really. If I can get a lot of 6 or 14 barely used identical tubes for the price of a "matched" pair, I'll usually get the lot instead, more fun and more tubes to play with, and spares of course.
  I believe I've accumulated some 20-25 pairs of just EF91/CV138/CV4014 lately, probably 15 pairs of different CV4014, and a pretty high number of 6AK5/6AJ5 before that, not counting what I'm waiting on. Sadly, I only have two pairs of CV4015 and not a single other EF92 tubes... These seem to be hard to come by, save for the Mullards. I need to start selling some tubes at some point; I'm sure I could give joy to a few people.


----------



## mordy

I have over 100 pairs of tubes, but almost every one was $4 or less, and some less than $1. As I see it, the supply of vacuum tubes is dwindling, and it seems to me that they will be worth more as time goes by. If I see a cheap lot of my favorite tubes I'll buy them if I can. Part of the fun is to see which variants sound better.
   
  I would also like to thank all the people who are exploring new horizons with unknown and new tube combinations for the LD MKIII. I thought I came across a really neat sounding tube in the 6AJ5, but maybe some of the newly found ones will sound even better!


----------



## Acapella11

Hey Mordy, good to see you posting.
  Am I right in saying that you are using the LD MK III rather as a pre- than a headphone amp?


----------



## mordy

Hi A11,
   
  That is correct. I have "the last great receiver" ( no, I did not make that up, but that is the advertising hype for the Outlaw RR2150 receiver, http://www.outlawaudio.com/products/rr2150.html. )
   
  It has an external loop where I connect the LD MKIII, and it allows me to use tone controls as well as a balance control. I keep the volume control on the LD at 9 o'clock, and the RR2150 volume quite low, but it still is plenty loud.
  A push button connects the LD in or out. The usual effect with the LD connected is that everything snaps more into focus and the musical presentation becomes more warm and lively.
   
  For speakers I use a double set up of four speakers and two self powered sub woofers. These are el cheapo speakers from Polk, Monitor 50 and PSW10, each costing $80 on sale by Newegg. The sound is excellent, besting my old audiophile Mirage M3si speakers. My music source is my CD collection put on I-tunes and various downloads from You tube.
   
  With this set-up it is very easy to hear differences in tubes. Since each channel in the LD is completely separate, I was hoping to arrange cables so that I can listen to a mono recording and hear the sound coming out simultaneously from both the R and L channels for one side of the LD. So far I have not been able to figure out how to do this.
   
  If I could figure it out, I could put in two different tubes, even from different families, and by using the balance control be able to A/B two tubes at the same time to compare them. Putting in two different tubes and moving the balance control R&L does not work for me in comparing the tubes. I suspect  that there is a synergistic effect from the two tubes working together, even though the two channels are truly separate. (BTW, David Zhe Zhe assured me that the amp would not be damaged by having different tubes in each channel.)
  Anyhow, I have not been able to figure out yet how I can audition one side through both R and L channels.
   
  I know that most people on this forum listen through headphones, but I am not comfortable with cans for long listening sessions, so I use the LD MKIII as a preamp.
   
  After going through scores of tubes to find what I like, I can now concentrate on listening to the music rather than listening to the sound of the amp. However, all the new suggestions sound very interesting and I am waiting for a consensus to come out on what to buy next.


----------



## Audiofanboy

Ok, I'm think I'm done with ordering new families of tubes for now... I covered virtually every type of tubes I speculated would be of interest in my amp (basic specs-wise and also from an audio/signal standpoint). So, I bought namely:
   
  - GE 6676/6CB6A (dual labeled apparently, the 6676 is the mobile equipment special version of 6CB6A, with a heater accepting +/- 1.3V, and I assume everything else more quality controlled, special quality version basically (Why get the plain vanilla version when the special version is the same price?))
   
  - CGE 6676, made by GE for Canadian GE (special mobile version again)
   
  - GE 8136 (special version of 6DK6, which I identified as an interesting tube for audio, with additional controls, the 8136 was made for specific signal processing, and massively used in Tektronics analysers. Tektronics appparently tested and sorted specific 8136 tubes for their equipement. Tubes you can know find easily and still tagged "Tektronics" and often sold in Tek-matched pairs NIB. I bought some non-Tek checked 8136 because I couldn't justify the price increase. I have high hopes for this tube.)
   
  - GE 6EW6 (military boxes, but no special version of this one. This is one of the higher current draw tubes I have high hopes for)
   
  - GE 6GM6 (regular version and box, similar if not almost the same as above, high hopes as well)
   
  - GE 6GX6/6GY6 (plain vanilla tubes, dual labeled, even higher current draw than above. These are the tubes this Alain guy was especially raving about. No special quality version available, but very high hopes for these with orthos (they should more than double power compared to EF92s))
   
  - GE 6AG5 (plain vanilla tubes, couldn't find slightly different yet compatible GE 6BC5/6CE5 cheap, and special quality version was overpriced. These are essentially US EF96. I suspect these ought to be used with the EF95 jumper setting, as pins 2 and 7 are hardwired together like the 6AK5, which may be the difference between settings actually; true pentode vs pentode hardwired as a triode?)
   
  - Reflektor-made 6J3P-E (what's a good tube buying binge if you don't go Russian a little? Russian EF96/6AG5 equivalent, OTK, rhombus and all, mid to late 70s; E stand for long life, no -EV/EB available like Infinity650 had bought but never commented on. Can't be bad really?)
   
  No, I'm not a GE fetishist lol, it's just that the GE tubes seemed high quality and often were the special quality versions. Feel free to buy more Sylvania, RCA or Raytheon tubes so we can compare!
   
  A few specs to put a bit theory on all this:
   
  - 6CB6A/6CB6/6676/6CJ6/7732 (special 6CJ6) *0.3A *Sharp-cutoff pentode
  - 6DK6/8136 *0.3A* Sharp-cutoff pentode
  - 6EW6 *0.4A* Sharp-cutoff pentode
  - 6GM6 *0.4A* Semiremote-cutoff pentode
  - 6BC5/6CE5 (Slightly different) 6AG5/EF96/6186/CV848/6J3P(-E/EV) *0.4A* Sharp-cutoff pentode (some sources say tetrode, especially for the 6J3P)
  - 6GX6/6GY6 *0.45A* Sharp-cutoff pentode
   
  I had also identified but could either not find with a nice brand and dated before the 80s or didn't deem immediately interesting for audio or already have and was not convinced by or didn't find powerful enough:
   
  - 6DC6 *0.3A* Semiremote pentode
  - 6BH6 *0.15A* Sharp-cutoff pentode
  - 6BA6 *0.15A* Remote pentode
   
  There are many more types that could work and sound good, I mainly looked at the >0.2A draw ones out of interest.


----------



## gibosi

Quote: 





audiofanboy said:


> Ok, I'm think I'm done with ordering new families of tubes for now... I covered virtually every type of tubes I speculated would be of interest in my amp (basic specs-wise and also from an audio/signal standpoint). So, I bought namely:


 
   
  WoW!! WoW!! WoW!!!!  This is so exciting!!  I can hardly wait to read your impressions!
   
  And based on Alain's earlier post I too purchased a pair of RCA 6GX6s. Great fun!!


----------



## Audiofanboy

Meanwhile, I think I've made sense of this whole jumper business, pin out, and why some tubes are compatible or not in the LD MK III/IV, after reading through a number of datasheets (that I barely understand), other google sources, the pics of the LD amp PCBs on the LD website, and this document on google, that finally helped me makes sense of the whole thing.
   
http://www.kaponk.com/~yanyong/ETF06TS.pdf (pages 11 onwards)
   
  The amp uses pentodes as driver tubes, strapped as triodes, meaning that instead of having a cathode, grid (1), grid 2 (screen), grid 3 (suppressor) and anode, it straps grids 2 and 3 to either cathode or anode, leaving only cathode+anode+grid = triode.
   
  On the 6AK5 tube, this is pretty easy, as the grid 3 is internally connected to the cathode (pin 2 = k+g3 is connected to pin 7 = k+g3). On the amp PCB the grid 2 is connected to the anode (pin 5 = a is connected to pin 6 = g2), thereby forming a perfect triode strapped pentode we've learned to love, with a by the book execution (g3 connected to k, g2 to a).
   
  On the EF92/91, things get more complicated as pins 6 and 7 are inverted (g2 and g3 are inverted), and no pins are hardwired together internally (k is not connected to g3). But on the LD circuit board, pins 5 (still anode) and 6 (now g3) are still connected, leaving g2 connected to nothing. This is where the jumper comes in handy. The jumper apparently connects pins 6 and 7 (g3 and g2) to pin 5 (anode), thereby creating another alternative triode strapped pentode by the book example with both extra grids connected to the anode.
   
  Are you following me so far? I barely am. So, this is what the jumper does to make the amp work with the usual types of tubes. Enter, 6CB6 tubes, and most of the other tubes I want to try for that matter, pins 1 to 5 are still the same, but pin 6 is now g2 again and pin 7 is g3 (like for the 6AK5), but nothing is hardwired internally (like the EF92/91), so it won't be triode-strapped with the EF95 jumper setting (and sound all flabby like when you tried your EF92 with the wrong jumpers). With the EF92 jumper setting, again pin 5 (a), 6 (g2) and 7 (g3) are connected, and you should get a normal triode strapped pentode, which is the only reason it works in the amp in the first place. The alternative solution to use these tubes with the 6AK5 setting, would be to hand-wire pin 2 (k) and pin 7 (g3), perhaps with a small flat wire soldered between the pins, which might offer better or similar triode performance like a real 6AK5, different noise rejection and such (and connect the internal shield to the cathode which should be better theoretically).
   
  This explains, why EF92 tubes with the 6AK5 setting don't explode (they just don't work well) and why 6AK5 tubes on the EF92 setting light up and try to kill themselves (anode and cathode become connected through internal and PCB wiring, which can't be good).
   
  One last thing, I've seen a few tubes with a 7 pin base and the right filament voltage, where the cathode (k) is wired to pin 7 and g3 to pin 2 (pins 2 and 7 are inverted basically), and not hardwired together. The 6AU6 tube (0.3A, sharp-cutoff pentode), which a lot of people like to use in DIY circuits, is like this. With a simple flat wire soldered between pins 2 and 7, and using the 6AK5 jumper setting (EF92 setting would make it explode again), these types of tubes could perfectly well work in the LD amps.
   
  If you have no idea what I'm talking about or haven't understood any of this, either ignore my post, or pull up a few tube datasheets from google and look at the pin layout for the tube, it might make much more sense then.
  
  EDIT: 6AG5 tubes are wired the same way as 6AK5s. That is, pin 2 (k+g3) is hardwired internally to pin 7 (k+g3), so it should work fine with the 6AK5 jumper setting as a triode-strapped pentode, but will surely explode if used with the wrong EF92 jumper setting (cathode and anode connected = bad).
   
  EDIT 2: The 6J38P tubes also have their cathodes connected to grid 3 (pin 2 connected to pin7). I should therefore be used with the 6AK5 setting, unless you want to see some pretty fireworks...


----------



## Audiofanboy

Quote: 





gibosi said:


> WoW!! WoW!! WoW!!!!  This is so exciting!!  I can hardly wait to read your impressions!
> 
> And based on Alain's earlier post I too purchased a pair of RCA 6GX6s. Great fun!!


 

 Great, another brand of tube, I'm very curious about your impression of these, as I have high hopes for these tubes!
   
  It is quite fun, but I have to say this is almost more tiring than my actual job haha... Just reading datasheets and browsing fleebay for tubes can be pretty intense (especially trying to optimize costs for international shipping).


----------



## gibosi

Quote: 





audiofanboy said:


> EDIT: 6AG5 tubes are wired the same way as 6AK5s. That is, pin 2 (k+g3) is hardwired internally to pin 7 (k+g3), so it should work fine with the 6AK5 jumper setting as a triode-strapped pentode, but will surely explode if used with the wrong EF92 jumper setting (cathode and anode connected = bad).
> 
> EDIT 2: The 6J38P tubes also have their cathodes connected to grid 3 (pin 2 connected to pin7). I should therefore be used with the 6AK5 setting, unless you want to see some pretty fireworks...


 
   
  Thank you for sharing this info! So.... when I get my Russian 6J38P tubes, I will definitely use the 6AK5 setting..... I was planning on using the EF92 setting....  But fireworks in my LD is not something I want to see!  ahaha.... And maybe I will grab some 6AG5s as well... I see some Sylvania JAN 6186 6AG5WAs at a good price....
   
  And yes, spending hours searching Google and eBay is very tiring.. and stressful... But when your mailbox is full of little treasures, all is forgotten!


----------



## gibosi

Speaking of finding little treasures in the mailbox - More C6B6As
   
   

   
  A pair of Tung-Sols and a pair of RCAs arrived today. I have done little more than toss them into my LD1+ to make sure they are not dead, but first impressions remind me of the Sylvanias, very smooth and musical. I can easily understand why these tubes have become thegreat682's default "go-to" tube. A great find!


----------



## Audiofanboy

Quote: 





gibosi said:


> Thank you for sharing this info! So.... when I get my Russian 6J38P tubes, I will definitely use the 6AK5 setting..... I was planning on using the EF92 setting....  But fireworks in my LD is not something I want to see!  ahaha.... And maybe I will grab some 6AG5s as well... I see some Sylvania JAN 6186 6AG5WAs at a good price....
> 
> And yes, spending hours searching Google and eBay is very tiring.. and stressful... But when your mailbox is full of little treasures, all is forgotten!


 

 Good catch on those 6CB6 tubes! Again, don't hesitate to post impression when you try them.
   
  About the 6AG5, before buying the (comparatively expensive) 6186/6AG5WA, I would try and get the cheap cheap 6J3P-E (ultra-military tubes, made in Reflektor factory, like the 6N30P-DR, which sounds like heaven in a glass bottle). These can be bought by 2/5/10/20 for the price of a pint of beer and a glass of wine worth of shipping... Why hesitate? This being said, there aren't even that many on fleebay, interestingly; and no -EV too... Which is why I bought them so quickly. There's the 6BC5/6CE5 too, cheap cheap to get NOS. Everything is cheap for these tubes, except a few select special types. I read about the 6AG5WA and for once can't tell what makes them special compared to the 6AG5 (mobile version, vibration, special instrumental version, google doesn't mention anything)?


----------



## MIKELAP

Quote: 





audiofanboy said:


> Meanwhile, I think I've made sense of this whole jumper business, pin out, and why some tubes are compatible or not in the LD MK III/IV, after reading through a number of datasheets (that I barely understand), other google sources, the pics of the LD amp PCBs on the LD website, and this document on google, that finally helped me makes sense of the whole thing.
> 
> http://www.kaponk.com/~yanyong/ETF06TS.pdf (pages 11 onwards)
> 
> ...


 
  BRAIN OVERHEATING to much data to much data lol


----------



## Audiofanboy

Quote: 





mikelap said:


> BRAIN OVERHEATING to much data to much data lol


 

 Took me about two-three evenings to make sense of all this lol... Just pull up the datasheet for 6AK5s or EF92s and look at the schematics for the pins, and it'll seem less abstract. Still, I'm a bit more reassured testing all those unofficial tube types, now that I understand the underlying theory somewhat


----------



## junkimchi

Did it take over a week before your amps even shipped from Little Dot directly? Because mine hasn't even shipped yet apparently and its been over a week now.


----------



## Acapella11

Mordy, Thank you for the details on your setup. It is interesting to see how you use the LD as pre amp and to be honest I haven't considered yet mixing tubes between different products.
  
 Thanks *thegreat682 *for coming up with the 6CB6A family of tubes, great stuff!
  
 Audiofanboy, OMG! You did it. Solved the EF95/EF91 pin switching function riddle and can now predict which tubes to use at which setting. To be fair, this shines new light on our little gem. I am getting too curious about the new high gain tubes, to not try them. Now, you are going to make me read data sheets, haha. I gonna check this presentation out too, looks interesting. The budget for the high gain tubes just comes up on the horizon.  Would be quite cool if we would find another family for the power tubes too. This could convert the LD a lot.
  
 Sylvania 6EW6 ordered.


----------



## MIKELAP

Quote: 





acapella11 said:


> Mordy, Thank you for the details on your setup. It is interesting to see how you use the LD as pre amp and to be honest I haven't considered yet mixing tubes between different products.
> 
> Thanks *thegreat682 *for coming up with the 6CB6A family of tubes, great stuff!
> 
> Audiofanboy, OMG! You did it. Solved the EF95/EF91 pin switching function riddle and can now predict which tubes to use at which setting. To be fair, this shines new light on our little gem. I am getting too curious about the new high gain tubes, to not try them. Now, you are going to make me read data sheets, haha. I gonna check this presentation out too, looks interesting. The budget for the high gain tubes just comes up on the horizon.  Would be quite cool if we would find another family for the power tubes too. This could convert the LD a lot. 
  That would be interesting new familys of power tubes i have the.6N6P-i, 6N6P,and 6h30pi gold pin if i didbt do any mistakes in my Russian alphabet translation.


----------



## gibosi

Quote: 





audiofanboy said:


> Good catch on those 6CB6 tubes! Again, don't hesitate to post impression when you try them.
> 
> About the 6AG5, before buying the (comparatively expensive) 6186/6AG5WA, I would try and get the cheap cheap 6J3P-E (ultra-military tubes, made in Reflektor factory, like the 6N30P-DR, which sounds like heaven in a glass bottle). These can be bought by 2/5/10/20 for the price of a pint of beer and a glass of wine worth of shipping... Why hesitate? This being said, there aren't even that many on fleebay, interestingly; and no -EV too... Which is why I bought them so quickly. There's the 6BC5/6CE5 too, cheap cheap to get NOS. Everything is cheap for these tubes, except a few select special types. I read about the 6AG5WA and for once can't tell what makes them special compared to the 6AG5 (mobile version, vibration, special instrumental version, google doesn't mention anything)?


 

 Actually, I found these Sylvania JAN 6186 6AG5WAs pretty cheaply. And I just assumed that as these are military tubes, they might be more rugged and durable, as is typical of mil spec tubes, but of course, I do not know. Also I took your advice and ordered the Reflector 6J3P-E tubes. As I have a an LD1+, with an op amp (opa2107), I was unaware that Reflector made power tubes that sound like "heaven in a glass bottle". Thanks for the tip!
   
  And just for grins, I am buying a couple pairs of 6BC5/6CE5s (GE and Sylvania), and a pair of Raytheon 6EW6s. (The 6EW6s require the EF92 setting? Someday I will sit down with the data sheets and your explanation above and figure this all out, but for now, it is much easier to ask the "Expert" . Gosh, this thread is killing my wallet! ahaha...


----------



## gibosi

Quote: 





junkimchi said:


> Did it take over a week before your amps even shipped from Little Dot directly? Because mine hasn't even shipped yet apparently and its been over a week now.


 
   
  I didn't buy my LD from Little Dot directly, so I can't be of any help... sorry.....


----------



## thegreat682

I'm thrilled that so many of you are pleased with the 6CB6A tubes!  I'm happy that after a decade of forum lurking I was finally able to contribute something to such a great community!
   
  After reading many posts here, I believe I'm going to break down and buy a few 6N6P tubes.  Is there a noticeable difference between the gold grid and the standard ones I'm seeing on eBay?  I'd love any feedback from those experienced with these tubes.


----------



## Audiofanboy

Quote: 





gibosi said:


> Actually, I found these Sylvania JAN 6186 6AG5WAs pretty cheaply. And I just assumed that as these are military tubes, they might be more rugged and durable, as is typical of mil spec tubes, but of course, I do not know. Also I took your advice and ordered the Reflector 6J3P-E tubes. As I have a an LD1+, with an op amp (opa2107), I was unaware that Reflector made power tubes that sound like "heaven in a glass bottle". Thanks for the tip!
> 
> And just for grins, I am buying a couple pairs of 6BC5/6CE5s (GE and Sylvania), and a pair of Raytheon 6EW6s. (The 6EW6s require the EF92 setting? Someday I will sit down with the data sheets and your explanation above and figure this all out, but for now, it is much easier to ask the "Expert" . Gosh, this thread is killing my wallet! ahaha...


 

 I forgot you most likely live in the US, where you can US tubes shipped to you for peanuts, that explains how you got tubes shipped to you so fast lol, and why I'd been buying UK/Russian tubes so far.
   
  Yup, EF92 jumpers for all these tubes except the 6BC5/6AG5/6J3P (and 6J38P).
   
  About rolling power tubes, I'm actually not sure we'd get better performance with another family of tubes (on the LD MK II / III / IV, not 1). The amp is pretty flexible for driver tubes but calibrated for a pretty specific type of power tube, which, I have to say, offers tremendous sound qualities. The 6N6P/6N30P family has some pretty high upper limits which are essentially the 6N30P-DR, the so-called (and not without reason) supertube, which is expensive but not by that much more of a margin than the recent 6h30Pi once you factor in its lifetime ($60 for 5000 hours, $200-250 for 10000-20000 hours), extra quality control and sound quality. It's not that bad when you look at the prices of good driver tubes in the Schiit Lyr thread...
   
  So, instead of spending another $100 rolling mystery power tubes (which I'm quite sure is possible if we investigate thoroughly) to get better performance, I would just get the DRs straight away and keep rolling cheap driver tubes.
   
  Speaking of which (shameless plug), I *might* be selling some extra power tubes I bought a few months ago as spares in a week or two, as I realized I will obviously not be using them in the next 15 years, as my current power tubes will most likely outlast the amplifier they're in. I'm still not sure where I should try to sell them, and I hate selling on fleebay with commissions at every step, so I might make a classified here. A matched quad, or two matched pairs of NOS NIB 6N30P-DR from 1980, so extra rare and disappearing fast, which was why I bought them in the first place. Give me a nudge if you're *hypothetically* interested.
   
  Apart from the 6N1P, no other different power tubes have been tried right?


----------



## mordy

Dear682,
   
  I have used the OEM 6N6P-i tubes that the amp came with, as well as the 6N6P and 6N6P gold grid power tubes.
   
  The 6N6P-i tubes are only rated for 500 hours (which I did not know when I got them), and I was surprised when one of them gave out after not such a long time. I replaced them with 6N6P tubes which were OK, but found that the gold grid 6N6P tubes sounded better. I think that these 6N6P tubes are rated for 3000 hours. Presently I use the gold grid power tubes together with the Tung Sol 6AJ5 with very good and pleasant results.
   
  I have my eyes on the 6N6P-IR tubes for around $30-40/pair. The R designation indicates extra long life, 10,000 hours. If I find a good deal on 80's tubes I may strike....


----------



## Acapella11

My line of thoughts was that the total power output might be limited by the power tubes even if you get high gain driver tubes. Isn't it like a normal audio chain or computer, you upgrade one thing but the next one won't be able to handle all the juice it receives?
   
  Yes, the 6n1p did not seem to be the flavour I was having in mind, considering they didn't power Grado 225is. And no, I don't think any other exotic power tubes were tried. I agree with putting the power tube a bit back, but depending on our experiences with the _new_ driver tubes, we might need to look at other bottlenecks (power supply, lol  ).
   
  My under dog suggestion for power tubes are the 6N6P-IRs. They have a quite different signature to the 6H30P-EV and a bit lower gain. In short: sub bass, large stage and sparkly treble are the strong points. The overall signature is slightly dark and they go well with the CV4015 if you like a neutral sound signature. Not much tubey warmth in this combination but rather tube-refined clarity. If you like a forward "in your face" sound, they are not for you. YMMV


----------



## Audiofanboy

Quote: 





acapella11 said:


> My line of thoughts was that the total power output might be limited by the power tubes even if you get high gain driver tubes. Isn't it like a normal audio chain or computer, you upgrade one thing but the next one won't be able to handle all the juice it receives?
> 
> Yes, the 6n1p did not seem to be the flavour I was having in mind, considering they didn't power Grado 225is. And no, I don't think any other exotic power tubes were tried. I agree with putting the power tube a bit back, but depending on our experiences with the _new_ driver tubes, we might need to look at other bottlenecks (power supply, lol  ).
> 
> My under dog suggestion for power tubes are the 6N6P-IRs. They have a quite different signature to the 6H30P-EV and a bit lower gain. In short: sub bass, large stage and sparkly treble are the strong points. The overall signature is slightly dark and they go well with the CV4015 if you like a neutral sound signature. Not much tubey warmth in this combination but rather tube-refined clarity. If you like a forward "in your face" sound, they are not for you. YMMV


 

 I'd say you're right about the "power limit" somewhere in the amp. I've read a few reports of DIY folks who got stuck changing driver tubes in circuits because if they used higher gain driver tubes, basically tubes with a higher 6.3V filament current draw, they had less 6.3V current left for the power tubes, assuming the 6.3V circuit is mounted in series in the amp for both driver and power tubes, which it should be.
   
  As the 6h30p/6n30p draw more filament current than the 6N6p family as it is (825 vs 750mA I think...?), we're bound to find some kind of upper current draw limit in the amp, and that first limit might be on the 6.3V part. That and heat dissipation, which I'm already kind of worried about just using EF91 tubes.
   
  This being said, find me a better, higher draw, power tube, and I'll still try it  . But I'll try messing around with those *new* driver tubes first. And now that I've figured out how the pin layout and jumper settings work, I've already found several new families of tubes that could be used with a small soldered wire between pins 2 and 7 on the 6AK5 jumper setting (a theory that I might very quickly put to the test, just because if will bother me if I don't). There's all sorts of new special quality tubes I envision testing with this scheme! I'll report back on that when I can actually confirm it, so we don't get all sorts of critical failures in the meantime...


----------



## inphu510n

Hi all,
   
  I've been lurking this thread for months now and have bought several tubes on recommendations left by members.
 Thank you all so, so much for putting so much of yourselves and your time into playing around in this stuff. It's really a different world in here. I really appreciate the support and investigation and the tinkering you guys have done here.
   
  I'll probably butcher some known audio terminology so forgive me now.
   
  My setup is FLAC/MP3/Spotify HQ -> DAC Destroyer -> Little Dot MKII -> Sennheiser HD280Pro.
  From what I've read the Senns are a darker headphone and therefore less prone to the brightness of say Beyerdynamics?
  I'm itching to buy some DT770's or the new Fischer Audio cans. My Senns are 10+ years old now.
   
  I'm not yet going to go into my impressions of tubes.
  I just ordered a pair of RCA 6766/6CB6A tubes and a pair of G.E. 6GX8's. Definitely looking forward to these tubes.
   
  I recently acquired a few Ultron "SQ" EF92 tubes and I'm wondering if you guys might be able to shed some light on what manufacturer they really came from. After some reading, I found that "Ultron" is a rebrand used by an audio store in West Germany quite a while ago and they would import and relabel tubes from different manufacturers.
  Here's the tubes:
  http://img.photobucket.com/albums/v96/inphu510n/Tubes/IMAG0478_zpsf15dd35b.jpg
  (BTW how do you directly show images in posts here? I can't seem to get it right)
   
  Any ideas?
  There is some small lettering "50402" on the side of the tube but other than that nothing else.
  My assumption is that they're a variant of the CV131 but none have the perforated shield these do.
  That folded getter is really surprising. Not a lot of gas conversion was possible with that setup.
   
  I'm loving these tubes! While they don't posses the analytical and excellent 3D imagery of the Voskhods the sub bass, bass and midrange are all so much sweeter and punchier. There's a slight roll off in the high end so it's not "sparkly" and exciting that way but overall every time I listen to these tubes I find myself tapping my toes and nodding my head.


----------



## Audiofanboy

Quote: 





inphu510n said:


> Hi all,
> 
> I've been lurking this thread for months now and have bought several tubes on recommendations left by members.
> Thank you all so, so much for putting so much of yourselves and your time into playing around in this stuff. It's really a different world in here. I really appreciate the support and investigation and the tinkering you guys have done here.
> ...


 

 Well, welcome here! Definitely don't hesitate to give impressions when you get you 6676/6CB6 and 6GX8 (6GX6?), we're all always looking for feedback, even in layman's terms.
   
  About your EF92s, yes Ultron was apparently a rebrander, that would rebrand just about any brand of tubes it could get its hands on. Looking at the picture of your tube, and comparing with what I've seen on fleebay, it could be a Thorn/AEI EF92/CV131 tube, from its shield with holes and what I can see from its getter.
   
  Like this one: http://www.ebay.fr/itm/2-x-EF92-CV131-6CQ6-WHITE-BOX-MADE-IN-ENGLAND-MESH-RECTANGLE-GETTER-/370751326625?pt=DE_TV_Video_Audio_Elektronenr%C3%B6hren_Valves&hash=item56528049a1
   
  When you post a reply, there's a small picture-like symbol "Insert Image" on the right side of the menu, where you can upload any picture you have and select what size you would like it to appear in your reply.
   
  Have fun rolling tubes!


----------



## Acapella11

Yay, EF92 tube love =) and welcome to the thread.
  Did you buy those from Cyprus via ebay? Or rather Germany 
   
  For photos, there is an "Insert Image" button in the most right section of the control button row above the text box. Then, you just point to the file, which you want to upload and determine the displayed size. Should be easy =)
  
   
  6.3 V, interesting finding Audiofanboy. So, this sets the max voltage. Curious to see what the max overall power handling of the LD MKIII /IV would be. Yes, the 6N6P are 750 mA. and the 6H30 825 mA (filament heater current, that is).
   
  If you are interested in 6H30 tubes, I found a write up, which explains why this tube was chosen for a balanced pre-amp of a company, I wasn't aware of before. Of course, it is an advertisement type document, so it wouldn't show negatives, still a fun read.
  http://www.balanced.com/products/line/Vk-50SE/6H30P.html
   
  haha, I was writing my post meanwhile you were doing yours.


----------



## inphu510n

Quote: 





acapella11 said:


> Yay, EF92 tube love =) and welcome to the thread.
> Did you buy those from Cyprus via ebay? Or rather Germany


 
   
  I bought them from Cyprus. 
  Took their sweet time getting to me. Somewhere close to a month. I bought 5 so it was worth it.
   
  One thing I've noticed in using the EF92's is that the power tubes get much, much hotter. Is that normal because of the extra current draw from the drivers?


----------



## Acapella11

Yes, the EF92 draw more current, thereby burning more energy and generating more heat. Unfortunately, it seems, the efficiency did not improve between EF95 and EF92 tubes. I am convinced that this more of power allows us a potentially better listening experience. It should be interesting with the 'new' (  ) driver tubes. Hope the LD won't melt down...


----------



## gibosi

Received a pair of Raytheon 6CB6As today.
   
   

   
  While the recent Sylvania, Tung-Sol and RCA 6CB6As appear to be from the 1960s, judging from the box and the tube graphics, these Raytheons would appear to be newer. Like thegreat682, these are becoming my "go-to" tubes. I think I have already purchased too many of these? But I have yet to hear a 6CV6A I don't like and I have a pair of 1962 mil-spec GEs coming. These will be the last ones. lol   Unfortunately, with all these new tubes, I have not had time to compare them closely, but I can say they all have a very similar sound, which reminds me of the CV4015s.
   
  As my headphones have a slight imbalance in the midrange, with the upper mids being a bit more forward, I find many 6AK5s to be too bright in the upper midrange (for example, female voices), and listening with any significant volume is sometimes uncomfortable. These 6CB6As, similiar to the CV4015s, complement my headphones very nicely. I should remind everyone that my ears can perhaps best be described as "rusty iron", as I am over 60, and my equipment is very modest, so I am looking forward to reading the impressions of those of you with "golden" ears and better equipment, especially how these 6CB6As compare to the Mullard CV4015s.
   
  And soon, my mailbox will be graced with 6AG5s, 6BC5s, 6J38P-EVs, 6J3P-Es, 6GX6s and 6EW6s. And maybe I should take a look at some 8136s over the weekend? lol


----------



## mab1376

Finally got my 6N6P-IR tubes today, my initial impression is that they are much more transparent than my Electro-Harmonix 6H30Pi.
   
  Listening to some Muse now though my Tung-Sol 6AJ5 tubes, very much liking this combo!
   
  Also just ordered a pair of GEC CV4014 (EF91), which is my first EF91 tube! Can't wait based on some impressions I've read.


----------



## Acapella11

gibosi, Thank you for sharing these impressions on the 6CB6A tubes. Given, the general signature is similar to the CV4015s and they are higher gain, they are listed on my short list now. If you compare the 6CB6As and CV4015, do you feel the higher power, at least in the sound being louder? This question goes also to thegreat682, comparing them to any EF92 tube in his stash 
  No need to call it "Rusty Iron", useful contribution is more precious than silver and gold 
   
   
  Audiofanboy, There was an obvious question, I didn't ask you, specifically now since you are a HE-500 comrade: Comparing the 6H30P-EV and 6H30-DRs, which you fell in love with, with the CV4015s on the HE-500, how much and what difference is there to be noted?
   
  mab1376, Exciting. Good to hear your impressions. Pleas keep us posted!


----------



## gibosi

Quote: 





acapella11 said:


> gibosi, Thank you for sharing these impressions on the 6CB6A tubes. Given, the general signature is similar to the CV4015s and they are higher gain, they are listed on my short list now. If you compare the 6CB6As and CV4015, do you feel the higher power, at least in the sound being louder?


 
   
  Yes, the 6CB6As are louder than the CV4015. This is what makes it so difficult for me to make a detailed sound comparison as the volume control has to be adjusted back and forth somewhere between 1/4 and 1/5 of a turn every time I swap out tubes. These 6CV6As seem to have the same level of volume as the GEC CV4014s, but the bass is not quite as big and the upper mids are a bit more subdued.


----------



## Audiofanboy

Quote: 





acapella11 said:


> gibosi, Thank you for sharing these impressions on the 6CB6A tubes. Given, the general signature is similar to the CV4015s and they are higher gain, they are listed on my short list now. If you compare the 6CB6As and CV4015, do you feel the higher power, at least in the sound being louder? This question goes also to thegreat682, comparing them to any EF92 tube in his stash
> No need to call it "Rusty Iron", useful contribution is more precious than silver and gold
> 
> 
> ...


 

 Coming from the 6H30Pi (EH, so *theoretically* just a tad better than the Sovtek), the 6H30P-DR brought a truly holographic (3D) soundstage; that was the first immediately obvious improvement, even before burn-in. After burn-in, much better extension, especially in the bass department (200Hz downwards), flying detailed highs and great transients, and a naturalness of timbres and decay that I had not heard before. Not minute differences, but quite major, and that was before I upgraded a few more pieces of gear like my S/PDIF transport and battery power, which made another night and day difference that scaled extremely well with the -DR and CV4015, even moreso with the HE-500 and good CV4014 tubes with more power and thump.
   
  I'll try my 6H30Pi again this week, just out of curiosity when I change my power tubes before shipping them. Just to anti-placebo myself again. I ought to sell my 6H30Pi too, it seems useless to keep them for no reason when they're definitely worth something and close to new...


----------



## Acapella11

Quote: 





audiofanboy said:


> Coming from the 6H30Pi (EH, so *theoretically* just a tad better than the Sovtek), the 6H30P-DR brought a truly holographic (3D) soundstage; that was the first immediately obvious improvement, even before burn-in. After burn-in, much better extension, especially in the bass department (200Hz downwards), flying detailed highs and great transients, and a naturalness of timbres and decay that I had not heard before. Not minute differences, but quite major, and that was before I upgraded a few more pieces of gear like my S/PDIF transport and battery power, which made another night and day difference that scaled extremely well with the -DR and CV4015, even moreso with the HE-500 and good CV4014 tubes with more power and thump.
> 
> I'll try my 6H30Pi again this week, just out of curiosity when I change my power tubes before shipping them. Just to anti-placebo myself again. I ought to sell my 6H30Pi too, it seems useless to keep them for no reason when they're definitely worth something and close to new...


 

 Thanks for posting your impressions. Appreciated. Interesting, because the negatives of the 6H30P-EV, I found, were a relatively flat stage, the other the lacking sub bass, both seem to be improved with the DRs.
   
  I have heard that battery give cleaner power. What setup do you use and do you use it for DAC and LD?


----------



## Audiofanboy

Quote: 





acapella11 said:


> Thanks for posting your impressions. Appreciated. Interesting, because the negatives of the 6H30P-EV, I found, were a relatively flat stage, the other the lacking sub bass, both seem to be improved with the DRs.
> 
> I have heard that battery give cleaner power. What setup do you use and do you use it for DAC and LD?


 

 Check the Hiface Two thread in computer audio for more details, the two last pages. Basically I use a M2Tech Hiface Two and a Little Dot DAC_1 (with AD797BR opamps (now RoHS compliant -BRZ) instead of the stock LM4562, which make are some of the best opamps you can get, and rival with discrete solutions) connected to my LD MK IV SE.
   
  The DAC_1 is a very nice unit with a single Wolfson WM8740 DAC chip (compared to 2 in the Cambridge Audio Dac Magic) and a toroidal transformer (unlike the Dac Magic). I'm still surprised how well it still scales with every gear upgrade I've made over the last year (like the MK IV SE, I have not found its limit yet, which is surprising for $300-$400 gear). But its USB input is just decent like most mid-fi DACs. Which is why I use the Hiface 2.
   
  The Hiface 2 uses "so-called" crappy USB 5V power (didn't believe in this until I changed its power supply) to power its onboard converters and clocks. Like for most USB-S/PDIF converters, there are many reports of massive changes in sound quality with better power supplies and batteries, but at a very high cost (like the John Kenny JKSPDIF & JKDAC both based on the Hiface with LieFePo4 batteries).
   
  So, I first made a DIY 5V USB power injector powered by an old phone charger, just to try it out, and found an immense improvement. I then made another USB hijack 5V power injector with a USB male adapter and a "5V" USB battery pack with a female USB plug, which I filled with 4 rechargeable Ni-MH batteries to get a clean 5V off-grid power supply lasting 15-20h. For the first time, I think I got close to hearing sounds from heaven on my HE-500, the difference was that dramatic, seriously. Don't believe me, try it for yourself. the weakest link in a computer-based audio system is the software and S/PDIF transport (or lack thereof if you can manage to get/make an I2s-based battery-powered USB transport-DAC, which I'll eventually lean towards when I have the cash). The two main limiting factors in my, at this point fairly optimized system, are the computer and S/PDIF stages and of course the tubes in my head amp, connected directly to my headphones (OTL design), hence my participating in this thread.
   
  Out of curiosity, what USB-S/PDIF (or other digital) interface/transports do all you people use here with you LD amps (if you have one)?


----------



## MIKELAP

Quote: 





audiofanboy said:


> Check the Hiface Two thread in computer audio for more details, the two last pages. Basically I use a M2Tech Hiface Two and a Little Dot DAC_1 (with AD797BR opamps (now RoHS compliant -BRZ) instead of the stock LM4562, which make are some of the best opamps you can get, and rival with discrete solutions) connected to my LD MK IV SE.
> 
> The DAC_1 is a very nice unit with a single Wolfson WM8740 DAC chip (compared to 2 in the Cambridge Audio Dac Magic) and a toroidal transformer (unlike the Dac Magic). I'm still surprised how well it still scales with every gear upgrade I've made over the last year (like the MK IV SE, I have not found its limit yet, which is surprising for $300-$400 gear). But its USB input is just decent like most mid-fi DACs. Which is why I use the Hiface 2.
> 
> ...


 
  I use my asus essence stx soundcard as dac for my Littledot MK3 with a pair of Denon LA D-5000 it sounds good for a $200.00 amp but i also use a Burson 160ds that sounds very good. With hi res files you dont want to go back to listening 44.1 files, thats like tube rolling,you get sucked in, takes up a lot of space dough.


----------



## inphu510n

Quote: 





audiofanboy said:


> Well, welcome here! Definitely don't hesitate to give impressions when you get you 6676/6CB6 and 6GX8 (6GX6?), we're all always looking for feedback, even in layman's terms.


 
   Whoops!  Yes 6GX6!!!
   
  Another thing I'm curious about is the gain setting I should be using. My Senns are 64ohm and I've got the gain set to 5. I didn't think that 64ohm headphones would be considered "low impedance".


----------



## Audiofanboy

Quote: 





inphu510n said:


> Whoops!  Yes 6GX6!!!
> 
> Another thing I'm curious about is the gain setting I should be using. My Senns are 64ohm and I've got the gain set to 5. I didn't think that 64ohm headphones would be considered "low impedance".


 

 64 ohms, while not low impedance per se, is still pretty low. Depending on your headphone sensitivity, I'd use either gain 5 or 10. I find my amp sounds better on 10 regardless of headphones, with more apparent power reserve.


----------



## Audiofanboy

An interesting piece of information I just found browsing google for ideas, as one might on a Sunday afternoon. I'd been wondering which suffix letters on Russian tubes mean long life, which ones ruggedized and so on. Here's what I found :
   
  "There are suffixes to the Russian valve numbers which indicate certain things -
 E (same in cyrillic)indicates a ruggedised construction.
 V (B in cyrillic) indicates military use - often means they draw a little more heater current than usual to get a lower noise figure.
 I (a backwards N in cyrillic) indicates that a valve is intended for pulse mode operation - these valves usually have a shorter working life, but can stand higher B+ than the standard designs.
 R (P in cyrillic) indicates low noise spec..
 D (a squiggly A with the top crossed over in cyrillic) means a 10K hour valve, automatically implies rugged construction - a European SQ type."
   
  So, again that explains the short life of 6N6P-I, as I think Mordy reminded us of a few pages back. But it would also imply that 6N6P-IR are basically the same thing with better noise specs, and in no way a longer life, or a normal life for that matter... Seems important enough to point out, as these still cost a few dozen dollars a pair, getting closer to the price of 6H30P. It also explains why all the -DR tubes (there aren't many types with DR suffixes actually) also sound great apart from having long lifetimes.
   
  Now, this has got me wondering if I made the right call buying 6J3P-E, and if I shouldn't have waited for an even higher spec model to pop up...


----------



## MIKELAP

Quote: 





audiofanboy said:


> An interesting piece of information I just found browsing google for ideas, as one might on a Sunday afternoon. I'd been wondering which suffix letters on Russian tubes mean long life, which ones ruggedized and so on. Here's what I found :
> 
> "There are suffixes to the Russian valve numbers which indicate certain things -
> E (same in cyrillic)indicates a ruggedised construction.
> ...


----------



## Acapella11

Quote: 





audiofanboy said:


> Out of curiosity, what USB-S/PDIF (or other digital) interface/transports do all you people use here with you LD amps (if you have one)?


 

 Thank you for the details Audiofanboy. I suppose that most commonly people use a DAC as their USB/SPDIF interface. I have been using a Beresford Caiman and recently bought an Audiolab M-DAC. The sound signatures are quite different. Please ask me for more details if you are interested.
   
  As a SS-option I am running an SPL Auditor, which has a unique 120 V technique to prevent distortion and over-driving chips, also it sounds neutral and has non-fatiguing treble.
   
  Yes, it seems there are conflicting information on the web for 6N6P-IR and thanks for sharing the details! But I am not worried about a shorter lifetime, even 500 h means probably a year of listening, and if they are better and extend to 2 to 3 years, that's enough for me. I wouldn't mind buying a pair every 3 years and god knows what amp I might have in 10 years... Additionally, there is no other tube that gives me the sound signature the IR provides, and as it stands, only the quite pricey 6H30P-DR would be an upgrade for me, of - at the moment - unknown quantity. So, I just enjoy the sound and see what happens. 
	

	
	
		
		

		
			




   
   
  And thanks Mikelap for posting this informative an comprehensive pic, only letter I am missing is the R (Russian P) as an ending descriptor, which Audiofanboy has picked up as low noise spec.


----------



## MIKELAP

.
  Would any of you guys know what brand this is i tough it was an RCA but rca logo doesnt look like this its a  JLRV 5654/6AK5W made in Canada


----------



## gibosi

Quote: 





mikelap said:


> .
> Would any of you guys know what brand this is i tough it was an RCA but rca logo doesnt look like this its a  JLRV 5654/6AK5W made in Canada


 
   
  Searching Google "JLRV Tube", the results indicate it is a GE Mil-spec tube made in Canada....


----------



## MIKELAP

Quote: 





gibosi said:


> Searching Google "JLRV Tube", the results indicate it is a GE Mil-spec tube made in Canada....


 
  Continued the search and found this it is a Marconi tube 
   
  finally ,found this picture of logo thanks for your help


----------



## Oskari

RVC = Radio Valve Co.of Canada. They stopped using RVC as a brand at some point and went with Marconi or CMC = Canadian Marconi Co. RVC also supplied tubes to CGE.
   
  N.B. JL*RV* (short for JAN-CL*RV*) & *RV*C.


----------



## MIKELAP

Quote: 





oskari said:


> RVC = Radio Valve Co.of Canada. They stopped using RVC as a brand at some point and went with Marconi or CMC = Canadian Marconi Co. RVC also supplied tubes to CGE.
> 
> N.B. JL*RV* (short for JAN-CL*RV*) & *RV*C.


 
  Thanks alot for infos appreciated.


----------



## Audiofanboy

Quote: 





acapella11 said:


> Thank you for the details Audiofanboy. I suppose that most commonly people use a DAC as their USB/SPDIF interface. I have been using a Beresford Caiman and recently bought an Audiolab M-DAC. The sound signatures are quite different. Please ask me for more details if you are interested.
> 
> As a SS-option I am running an SPL Auditor, which has a unique 120 V technique to prevent distortion and over-driving chips, also it sounds neutral and has non-fatiguing treble.
> 
> ...


 

 So you use an oversampling DAC, I hear that doesn't always mix well with USB-Digital interfaces (DAC oversamples to reduce the effects of jitter as it is, so further optimizations may not help much); I guess we use different strategies, hopefully with similar good results!
   
  Speaking of SS and extra power, I finally managed to find out whether the output power specs of the LD amps are for both channels or for each. Good news: *it's for each*. So, that's a minimum of 200 mW total @ 32 ohms, hopefully a bit more at for orthos with a slightly higher impedance rating and with higher current draw tubes. Maybe something like 300 mW total in practice on a HE-500 (far from the recommended 1W, but getting closer as things get optimized).
   
  About the 6N6P-IR, I just figured it might be a useful piece of information before splurging and buying a huge stash of them (or to go ahead and buy a stash of them just in case they don't last that long, either way lol).
   
  After -E, -EV/EB, -I, -IR, -DR, I've discovered there are also -ER Russian tubes (long life / high reliability, low noise like all the best power tubes we like).
   
  I just got three different types of tubes in the mail today, the first of a loooong list I intend to investigate. Mullard CV5377 from 1968 (special quality CV4014, which were special quality 6AM6, which are sp... You get the point), Canadian GE 6676 made by US GE 6CB6A/6676 (NOS, so burn-in required before any serious listening), and GE 8136 (instrument version of the 6DK6) used so I should report back about these soon.


----------



## Acapella11

Hey Audiofanboy, just a brief update for now:
   
  Oversampling / Upsampling:
   
  "Oversampling is the process by which an analog signal is digitally sampled well above the Nyquist rate (2x it's real bandwidth). Upsampling is a process by which an already digitally sampled signal is sampled above it's original sampling rate."
   
  In summary, upsampling seems not good for the signal, whereas oversampling is quite common and generally found to be useful. But, yes it does basically "interpolate" steps in the original signal curve. I am not sure what the context with jitter is. Oversampling is much older than the knowledge about jitter, think about the old and glorious Philips 4 x oversampling chips. There is a de-jittering mechanism in place for the M-DAC but to be fair I haven't yet researched how it works.
   
   
  LD power
   
  Excellent! I think if we manage 400 mW that would be a useful (surely not optimal, but still) amount of power. I heave read that - in theory - 6H30 tubes for example can do 4 W max, as well as 300 V, if the environment supports it. Now, I have to check on the 6N6P tubes, but even if it is just 1 W, and maybe even 500 mW in the context of the LD, then that's a reasonable to good value for the HE-500. Another question is whether the higher gain also relates to more effective power or just more loudness. I have read about this before. Usually, louder sounds better though it seems.
   
   
  6N6P-IR
   
  Yeah, it was an interesting finding. I would still wholeheartedly recommend to get one pair and then see for yourself 
   
   
  Other tubes 
   
  Interesting stuff!


----------



## gibosi

Over the weekend, I had some time to more closely compare the 6CB6As in my possession. I have 1960s era Sylvania, Tung-Sol and RCA, and 1970s or newer Raytheon (all consumer grade tubes), and Mil-spec GEs, dated 1962, and Sylvanias, dated 1978. I think I went a little nuts and bought too many of these! lol But they were cheap and it's been fun.
   
  Anyway, all of these tubes, with the exception of the Raytheons, sound the same to me. If there are differences, they are too subtle for my old rusty iron ears and cheap headphones to detect. This is surprising to me, given that different brands of 6AK5s have such different sound characteristics. Actually, the Raytheons sound the same as the other 6CB6As too. The difference is that they are not as loud. This is too bizarre!. All the other 6CB6As, including the 1978 Sylvanias, are significantly louder than my Mullard CV4015s (date code 81-14). However, these Raytheons seem to be no louder than my Mullards, and as a result, I was able to more closely compare these two tubes without feeling the need to readjust the volume. To my ears these two tubes sound very similar, but there are some differences. However, I lack the experience and the vocabulary to be able to clearly understand and articulate just what I am hearing, so I think all I can safely say is the Mullards sound more musical to me.
   
  And so ends my journey through the land of 6CB6As. lol 
   
  Todays mail brought me a pair of Raytheon 6EW6s and a pair of RCA 6GX6s.  I did manage to briefly plug them into my LD  and I am happy to report they seem fine, and I hope to be able to spend more time with them later this evening.


----------



## Audiofanboy

Quote: 





acapella11 said:


> Hey Audiofanboy, just a brief update for now:
> 
> Oversampling / Upsampling:
> 
> ...


 
   
  Interesting, I keep hearing about either Non-oversampling (NOS) DACs or the opposite, and their virtues about jitter-battling, but I never investigated whether that was at the digital or analog stage of things. I'll look further into this, out of curiosity. I know there are other "de-jittering" mechanisms, such as reclocking too. It's just the Beresford webiste mentions that about the Caiman DAC so I was a bit curious.

 If the 6N6P/6N30P tubes in a class A push-pull can give 500mW per channel (@300-600 ohms), assuming that is with 6AK5 tubes, then we could expect some degree of extra power with more "powerful" driver tubes (higher filament current draw? Higher plate current? Higher transconductance or mu? I understand barely 10% of all this... Although higher transconductance seems correlated with higher listening pleasure to me so far with what little time I had to test my 8136 tubes today). The problem is, I do not know what essentially limits these amps... Still, I'm quite sure 300-400 mW total power is reachable @ 32-50 ohms with a few improvements.
   
  I'd love to try some 6N6P-IR, does anyone live close enough to lend me a pair of these  . More seriously if I can find any cheap -xR type Russian driver or power tubes compatible (or that I can make compatible) with my LD amp, I will definitely try them!
   
  Gibosi, I'm looking forward to your feedback on 6EW6 and 6GX6 tubes, until I get mine sometime this week. So far, I can say that the 8136 tubes hold great promise, not in the sense that they're more powerful or anything, but because of their transparency and great extension. The 6676 tubes, with a few hours of burn-in, seem interesting but less lively and extended than the 8136. But both seem less "fun" and liquid than the GEC CV4014. The 8136 really does seem to have some high qualities, as I was expecting (tube is used so should sound close to its normal sound without burn-in), with deeper bass and spikier treble (good for electronic music), good soundstage and very detailed. Will continue testing and report a bit more tomorrow.
   
  What saddens me about tube rolling is how it is making me a tube cynic... I love my GEC CV4014, which are sort of my best happy private unexpected discovery, but now that I'm comparing them to other good high current draw tubes, I'm already starting to feel how the CV4014 are still a compromise, and how other tubes will most likely end up coming on top eventually...


----------



## mab1376

Quote: 





audiofanboy said:


> Interesting, I keep hearing about either Non-oversampling (NOS) DACs or the opposite, and their virtues about jitter-battling, but I never investigated whether that was at the digital or analog stage of things. I'll look further into this, out of curiosity. I know there are other "de-jittering" mechanisms, such as reclocking too. It's just the Beresford webiste mentions that about the Caiman DAC so I was a bit curious.
> 
> If the 6N6P/6N30P tubes in a class A push-pull can give 500mW per channel (@300-600 ohms), assuming that is with 6AK5 tubes, then we could expect some degree of extra power with more "powerful" driver tubes (higher filament current draw? Higher plate current? Higher transconductance or mu? I understand barely 10% of all this... Although higher transconductance seems correlated with higher listening pleasure to me so far with what little time I had to test my 8136 tubes today). The problem is, I do not know what essentially limits these amps... Still, I'm quite sure 300-400 mW total power is reachable @ 32-50 ohms with a few improvements.
> 
> ...


 
   
  Just one more reason I'm happy i bought a pair of the GEC CV4014 tubes 
   
  Waiting on them to arrive from the UK to NY.
   
  my collection keeps growing, currently breaking in my new 6N6P-IR tubes, they're very nice! can't seem to put my finger on the signature just yet compared to my 6H30Pi other that being much more transparent.
   
  Curious to see what your research finds for the ER and XR 6N6P variants. Happy Hunting!


----------



## Acapella11

Quote: 





> > I'd love to try some 6N6P-IR, does anyone live close enough to lend me a pair of these  . More seriously if I can find any cheap -xR type Russian driver or power tubes compatible (or that I can make compatible) with my LD amp, I will definitely try them!


 
   
   
  If you come to the Head-fi headphone meet on the 27th of April in London, we could do some tube rolling action


----------



## Audiofanboy

Quote: 





acapella11 said:


> If you come to the Head-fi headphone meet on the 27th of April in London, we could do some tube rolling action


 

 Oh, you know that's actually not a bad idea, it never occurred to me; that and I hadn't figured out or forgot you were British  .
   
  mac1376, about the Russian tubes and the -xR, I meant "x" as any letter lol, I only know of "DR" and "ER" tubes so far, but I meant I'd be willing to test any Russian tubes with the low noise "R" characteristic.
   
  Listening to the 8136 intently, after a few hours of burn-in/try-every-couple-hours of the 6676. So far, I would say that the 6676 have a very pleasant sound signature, kind of like quality transparent sound in a large bubble, nice for vocals, but with a slight lack in upper and lower frequencies, a lack of fun and punch basically, but pretty good nonetheless. The 8136, on the other hand, while not perfect, are showing great promise, the bass on these is nice and punchy without sounding silly and obtrusive like other tubes I've had so far, and the flying airy non-annoying highs remind me of what I like in the EF91 family. I'm starting to think that what I find odd about these is that they sound somewhat un-tube like, a bit SS-like actually, much less liquid than the GEC CV4014 at any rate, which I liked precisely because they were liquid-sounding. Still, a very interesting tube that would complement my CV4014 for electronic music because of this. I haven't quite wrapped my head around these 8136 yet though, they keep surprising me...


----------



## gibosi

Received 6EW6s and 6GX6s yesterday and decided, based on Alain's strong recommendations, to put the 6GX6s in my LD to start. After about 10 hours of burnin my first impressions are that Alain was spot on. The first thing I noticed about these tubes is they are very quiet. Against such an utterly quiet background the music is detailed and crystal clear with a very liquid presentation. Again, these are first impressions, but in my opinion, this tube is a keeper and and I encourage everyone to get a pair of these.


----------



## Audiofanboy

Quote: 





gibosi said:


> Received 6EW6s and 6GX6s yesterday and decided, based on Alain's strong recommendations, to put the 6GX6s in my LD to start. After about 10 hours of burnin my first impressions are that Alain was spot on. The first thing I noticed about these tubes is they are very quiet. Against such an utterly quiet background the music is detailed and crystal clear with a very liquid presentation. Again, these are first impressions, but in my opinion, this tube is a keeper and and I encourage everyone to get a pair of these.


 

 And in terms of gain, or volume, how would these compare to the classic EF92 and EF91? As the specs shows a very high filament current draw, but not that much power output (pentode connected though, which is why I'm curious about its behavior triode-strapped).


----------



## kLevkoff

About DACs....
   
  The purpose of oversampling is to simplify filter design, which makes it easier to design a better sounding filter (and cheaper to build it). At the 44.1 sample rate used on CDs, you need a very steep filter right above 20 kHz, which tends to be a poor compromise. By interpolating samples, the sample rate is raised, which raises the Nyquist frequency, which allows the designer of the DAC to use a filter that cuts in more gradually and at a higher frequency. This filter is both easier to design and build and easier to design such that it doesn't degrade performance in the audio band. Other than that, oversampling per-se shouldn't change the sound.
   
  While various types of DACs are more or less sensitive to jitter, that is not "the big draw" with NOS DACs. (If you use some method to remove jitter, then it doesn't matter how sensitive your DAC is to it - within reason.) The main argument put forth by "the NOS DAC camp" is usually that certain NOS DACs "sound good" - and this difference tends to be attributed to the fact that "they use the original samples/data rather than fiddling with it". (They will say it in rather more creative ways, but that is the gist of it. It appears to me more like they prefer the sound of a specific chip, and then rationalize that it is somehow "better" *because* it is a NOS type chip.) In general, sigma-delta DAC chips generally perform better in all measurable ways than NOS DAC chips.... whether because the technology is always better or simply because most modern DAC chips are of that type. There are claims that S-D DACs are more affected by jitter but, as I said above, if you're keeping jitter low, and/or removing it entirely, then this is unlikely to matter. The fact is that many of the "beloved" NOS DAC chips perform very poorly in terms of noise and distortion.
   
  Jitter is a specific phenomenon, and is not specifically related to the type of DAC you use. Jitter is caused by problems in data transmission or generation, and there are various ways of controlling or eliminating it. (Basically, you reclock the signal with a clean clock: either by having an asynch USB interface - which most better USb DACs do these days, or by removing it after the fact using a good PLL - common in older DACs, or an ASRC - common in newer DACs like Benchmark DAC-1 and Emotiva XDA-2, or some other similar mechanism - like in most newer Sabre DACs.)
   
  Quote:


audiofanboy said:


> Interesting, I keep hearing about either Non-oversampling (NOS) DACs or the opposite, and their virtues about jitter-battling, but I never investigated whether that was at the digital or analog stage of things. I'll look further into this, out of curiosity. I know there are other "de-jittering" mechanisms, such as reclocking too. It's just the Beresford webiste mentions that about the Caiman DAC so I was a bit curious.
> 
> If the 6N6P/6N30P tubes in a class A push-pull can give 500mW per channel (@300-600 ohms), assuming that is with 6AK5 tubes, then we could expect some degree of extra power with more "powerful" driver tubes (higher filament current draw? Higher plate current? Higher transconductance or mu? I understand barely 10% of all this... Although higher transconductance seems correlated with higher listening pleasure to me so far with what little time I had to test my 8136 tubes today). The problem is, I do not know what essentially limits these amps... Still, I'm quite sure 300-400 mW total power is reachable @ 32-50 ohms with a few improvements.
> 
> ...


----------



## kLevkoff

Oversampling is used to simplify filter construction - it is NOT a technique to minimize jitter. (Depending on how it is done, it may increase or decrease sensitivity to jitter). There are several methods for reducing jitter: asynch USB interface, reclock by PLL, reclock by ASRC, and the one Sabre uses (which is sort of a digital PLL). The USB interface itself is notoriously HIGH in jitter, so some sort of jitter reduction is always a good idea with USB. By far the most common way of eliminating jitter (although it is specific to the USB interface) is to use an ASYNCHRONOUS USB INTERFACE, which re-clocks the USB data to a local clock at the point where it is received. Most high-quality USB-to-S/PDIF converters these days (and most good DACs with USB inputs) are asynch USB.
    
   
  Quote:


audiofanboy said:


> So you use an oversampling DAC, I hear that doesn't always mix well with USB-Digital interfaces (DAC oversamples to reduce the effects of jitter as it is, so further optimizations may not help much); I guess we use different strategies, hopefully with similar good results!
> 
> Speaking of SS and extra power, I finally managed to find out whether the output power specs of the LD amps are for both channels or for each. Good news: *it's for each*. So, that's a minimum of 200 mW total @ 32 ohms, hopefully a bit more at for orthos with a slightly higher impedance rating and with higher current draw tubes. Maybe something like 300 mW total in practice on a HE-500 (far from the recommended 1W, but getting closer as things get optimized).
> 
> ...


----------



## Audiofanboy

Quote: 





klevkoff said:


> Oversampling is used to simplify filter construction - it is NOT a technique to minimize jitter. (Depending on how it is done, it may increase or decrease sensitivity to jitter). There are several methods for reducing jitter: asynch USB interface, reclock by PLL, reclock by ASRC, and the one Sabre uses (which is sort of a digital PLL). The USB interface itself is notoriously HIGH in jitter, so some sort of jitter reduction is always a good idea with USB. By far the most common way of eliminating jitter (although it is specific to the USB interface) is to use an ASYNCHRONOUS USB INTERFACE, which re-clocks the USB data to a local clock at the point where it is received. Most high-quality USB-to-S/PDIF converters these days (and most good DACs with USB inputs) are asynch USB.


 

 Thanks for the explanation, I do remember reading about how some people feel very highly for their NOS DACs and will defend them to death. I personally would tie most differences and feelings to the type of chip used and its implementation, as you said. For example, I like the sound of Wolfson DACs, but knowing my tastes, I'm pretty sure I would let it go for a good Sabre DAC if everything I've read about the chip is true. About the evils of jitter, I do the first two or three things you mention, namely, asynch USB, quality data clocking at the S/PDIF conversion stage, and my DAC reclocks the incoming digital signal before sending it the DAC chip, which I'd say matters the least in the chain so long as it's decent in the first place -at least this is what my experience so far has tended to show me, as I have not managed to reach the "limits" of my desktop DAC yet and it still improves every time I improve something at the USB / S/PDIF stage (unlike my portable DAC, which uses the same WM8740 chip, and has reached its limits depending on what I've thrown at it).
   
  Back to topic, I'm still waiting for my other tubes to go halfway around the globe and reach me, so I can only show pics of the tubes I've received and tested up to here.
   
  The CGE 6676 (see the vertical etched "6CB6A" somewhere on the tube, that shows a US GE making, although it doesn't really show on the picture...)
   

   
  The Mullard Mitcham-made CV5377 and a dirty box that came with them
   

   
  And my current favorite, the GE 8136 (that has not dethroned the GEC CV4014 though)


----------



## gibosi

Quote: 





audiofanboy said:


> And in terms of gain, or volume, how would these compare to the classic EF92 and EF91? As the specs shows a very high filament current draw, but not that much power output (pentode connected though, which is why I'm curious about its behavior triode-strapped).


 
  Did an A/B between these and the GECs to quickly compare gain, and I can detect no difference. I do notice that both tubes have big bass and good highs, and they match up very well, I think. But, no, it appears that in this case, at least, 450mA versus 300mAs does not get you any increase in gain. That said, it might be worth noting that the 1+ uses an op amp instead of power tubes on the chance it might be a factor?


----------



## Acapella11

Audiofanboy, what is the rank order in terms of power output of these 'new' tubes?


----------



## Audiofanboy

Quote: 





acapella11 said:


> Audiofanboy, what is the rank order in terms of power output of these 'new' tubes?


 

 CV5377 (=CV4014) > 8136 >= 6676
   
  The 8136 and 6676 have a bit less volume than the very high gain EF91 tubes, and I'd say that the 6676 have a bit less than 8136, but it's half volume and half the way the sound is staged. Up to now, my highest gain 300mA filament draw tubes are still the CV4014.
   
  Finally today, a few of the tubes I was expecting came in. So as a supposed GE fetishist (as I suddenly realize it's ALL GE tubes lol), I'll be testing:
   
  - GE 6EW6 in military boxes, dated 74 and 75, which is smack in the range I wanted (mid-60s to late 70s), they're going in first
  - GE 6GM6 in normal boxes, datecode CA, so early since you don't get letter codes in later 50s, 60s and 70s datecodes, these look pretty sturdy actually
  - GE 6AG5, plain Jane tubes, 1958 and 1962 (passively confirming that the above tubes could be from the late 50s, these look 60 years old), the two tubes have different colored markings and getter structure (which saddens me... But it's ok, I bought these more as a test of the 6AG5 family)
  - GE 6676/6CB6A, both RN datecode, so sometime in the 50s or early 60s I guess, I'll take this chance to point out that these look strictly identical to my Canadian GE made by US GE 6676, internal structure, getter and etched 6CB6A marking, tube is dual labeled 6676/6CB6A
  - GE 6GX6/6GY6, JE and NI so again 50s probably, the boxes sure look like they survived the 60s onwards, tubes are dual labeled 6GX6/6GY6
   
  Voila, I have the 6EW6 in for burn-in for a work day, first 15-minute impressions are that it is "interesting", and different from all the other tubes. Definitely a bit more powerful on the HE-500 with more bass slam, and a tad more volume than the CV4014, and quite more than the 6676 and 8136.
   
  I have to say, up to here I don't regret buying the tubes I tested. Those are all ultra-precise top-tier tubes, which makes it quite difficult to compare them. Fascinating world really, and cheap cheap cheap! (Much cheaper than buying $25 M8100, waaayyy overpriced...)
   
  I'll try to get some pictures up at some point, as it makes it easier to know what to expect when you shop.


----------



## gibosi

After seeing  *Audiofanboy'*s pictures that look like they belong in an art gallery, I thought I should try to up my game. lol
   
  While still not good enough to put up in an art gallery, these are a bit better....
   
  While his tubes are GE, these are RCA 6GX6s. I assume the MM is some sort of date code. I really like these tubes.
   
   

   
  And these are Raytheon 6EW6s. The left one is stamped made in Japan. These are currently burning in.....


----------



## MIKELAP

Quote: 





gibosi said:


> After seeing  *Audiofanboy'*s pictures that look like they belong in an art gallery, I thought I should try to up my game. lol
> 
> While still not good enough to put up in an art gallery, these are a bit better....
> 
> ...


 
_FILES/RCA DATE CODES.pdf . try this link i saw your MM code.


----------



## Acapella11

Quote: 





audiofanboy said:


> Voila, I have the 6EW6 in for burn-in for a work day, first 15-minute impressions are that it is "interesting", and different from all the other tubes. Definitely a bit more powerful on the HE-500 with more bass slam, and a tad more volume than the CV4014, and quite more than the 6676 and 8136.


 
   
*Sylvania 6EW6 *arrived, stuck in, burned in for just 1 hour, aaaaannnd... Nice! As you say more bass slam. Generally, these sound nicely warm but still balanced. Let's see how they develop. And there is the tube rolling fever back .
  My volume dial went back quite a bit. These seem to kick the HE-500 quite nicely. With a gain of 10 I listen now at 9 to 9.30, tempted to reduce the gain to 5. These sound very promising already. Absolutely no regret there.
   
  After the first impression, it sounds like what we were hoping for Audiofanboy


----------



## Audiofanboy

100th post (101th...), at last I feel like I'm finally credible here lol.
   
  I let my 6EW6 burn in for about a business day while I was at work today, but even listening after this, I feel that I can't quite reach a conclusion on these yet. I tried the GE 6AG5 really quickly earlier (which I don't expect to be using anyway as they aren't physically matched), my only conclusion would be that this family could show great promise, but not necessarily these old world 6AG5s. Still, I noted a nice slightly tube-y sound signature, and imagining a more selected/military model, I'm sure that family could reach great performance. Again, 6AK5 jumper settings for the 6AG5.
   
  Speaking of changing jumpers, as I had to go from the EF92 setting to the 6AK5 one and back, I gave myself quite a scare testing my GE 6676/6CB6A earlier... I put them in, turned the amp on, heard a slight noise, and the driver tubes filaments took like 10 seconds to begin lighting up, and the power tubes also. I listened for a bit, and found similar impressions compared to my other CGE 6676 tubes. When I switched the amp off, it made a loud BZZZZZ sound for a few seconds, that had me pretty worked up. So I tried switching the amp on again with the same tubes, this time the filaments lit up right way but as soon as I tapped the amp with my finger, the 4 filament just went dark. I was literally convinced I had killed my amp by burning in a 400 mA filament current tube for the whole day... So, I reached for the plug to try and troubleshoot the issue, and it turns out the plug had come loose after fiddling with the amp to change jumpers twice. I put the plug back in, started the amp back up, it worked perfectly, I started breathing again. Lesson learned, check cables after putting the amp upside down a couple of times...
   
  Anyway, after that heart-stopping problem, i resumed testing other tubes, and tested my fourth pair of tubes, the very odd spec-ed 6GX6/6GY6 (which actually has 6GY6 etched in the glass). Very high heater/filament current draw at 450 mA, but very un-audio like specs with transconductance and plate current (the specs I've convinced myself have the highest influence on "power") lower than a 6AK5, and meant to be a "dual control pentode" for FM detection, a far cry from nice sharp-cutoff pentodes well-suited for audio -as a pentode that is. It turns out these dual control pentodes once triode-strapped work very well in audio circuits for some mysterious design reason (look it up on google).
   
  So, after a couple of hours with these tubes, I can say these are the best in my latest batch of non-LD certified tubes; outrageous performance for $3 a pair... And they aren't even burnt-in yet, holy schiit... Apart from the bass -which is a bit lacking in slam- and the volume (which is as high as a 8136 or a 6676, just low for a 450mA filament current draw), these are some of the best tubes I've put in my LD amp. They're just natural, basically. Sounds come in the most natural and detailed way from logical directions around your head, and proceed to give you constant small eargasms, that themselves sound like the most natural thing to be having while listening to music with these tubes. I'll hold off on describing these with real audiophile words until they're burnt-in, but seriously these are quite a discovery!
   
  As a matter of fact, it's the use of "crappy" TV-intended very specifically designed dual control pentodes -and not signal pentodes- in audio systems that is interesting (again, google it), as they make extremely linear -and very inefficient- triode-strapped pentodes. I'll be looking for more tubes with specs like this, as there have been many made throughout the years, apparently
   
  The last tube I intend to spend time with is the 6GM6 I got (high transconductance, very high plate current), which should sound glorious triode-strapped. That might have to wait until this weekend, as I end up not having enough time to actually test all my discoveries  ...
   
  Now, pictures:
   
  GE 6AG5 (two different structures)
   

   
  GE 6GM6
   

   
  GE 6676/6CB6A
   

   
  GE 6GX6/6GY6
   

   
  Military GE 6EW6
   

   
  Edit: my only worry with the 6GX6/6GY6 triode-strapped is that I'm pretty sure it's way over its heat dissipation specs (it is meant for 1.7W plate dissipation, which is like half of a 6EW6) as the control/suppressor grid(s) no longer serve their purpose as they are tied to the anode. Just food for thoughts.


----------



## mab1376

At this point David from LittleDot should be paying you for all your research!
   
  Keep up the good work!


----------



## Acapella11

The 6AW6 do a good job so far, different from the CV4015 but worth listening if you like a little tubier but balanced type of tube, for example M8100 fans. For more details, I want to burn them in 20 - 30h but they surely are enjoyable.
   
  Here is a pic:

   
   
  I also ordered already a pair of 6GX6/6GY6 tubes. gibosi's and your positive impressions make me really look forward to these.
   
  Stripping down pentodes is the way forward  Exciting LD tube rolling times and keep us updated!
   
  Edit: They sound crisper and pair very well with my 6H30P-EV.


----------



## gibosi

Quote: 





> Edit: my only worry with the 6GX6/6GY6 triode-strapped is that I'm pretty sure it's way over its heat dissipation specs (it is meant for 1.7W plate dissipation, which is like half of a 6EW6) as the control/suppressor grid(s) no longer serve their purpose as they are tied to the anode. Just food for thoughts.


 
   
  Yes, I noticed that my 6GX6s seem to run pretty hot....  Might it be reasonable to infer that these tubes will have to be replaced more often? A heat-shortened lifespan?
   
  On the other hand, when I have 408As installed (20 volt rather than 6.3), they too are similarly pretty hot, so maybe this is not a problem....


----------



## Audiofanboy

Quote: 





acapella11 said:


> The 6AW6 do a good job so far, different from the CV4015 but worth listening if you like a little tubier but balanced type of tube, for example M8100 fans. For more details, I want to burn them in 20 - 30h but they surely are enjoyable.
> 
> Here is a pic:
> 
> ...


 

 Interesting about the 6EW6. I just couldn't make up my mind whether they were very good or average good earlier after 8-9h of burn-in. Just too hard to differentiate from the 8136 and 6676 tubes I'd been testing right before without placebo-ing myself, and I don't want to give any false impressions either... It's good you tried them also with 6H30P tubes, which often sound pretty different.
   
  Meanwhile, I'm having quite the experience with my MK IV SE and its 6GX6/6GY6 strap-on pentode. They're not quite perfect yet, but they seem to do everything well, as in no musical style gets annoying after a couple of songs (as it often does when I'm testing more spiky or grainier tubes). And as is often the case during burn-in, the bass seems to be settling in a little.
   
  Out of curiosity, which brand did you go for? Actually dual labeled? Thank for the pic of the 6EW6 tube; pics really are valuable when you go tube hunting yourself.
   
  Gibosi, I honestly am not sure what running with a higher heat dissipation could do to those tubes. I mean, you'd think if they were made to run off of a 450 mA heater, they should be somewhat heat resistant, but the cathode might not be... Still, it's more the amp I'm a little worried about, but these don't seem to run *that* much hotter than a lot of EF91s I've tested. I guess it's fine, so long as the indoor temperature doesn't rise too much (the amps runs *much* hotter in the summer -without A/C).


----------



## Acapella11

Quote: 





audiofanboy said:


> Meanwhile, I'm having quite the experience with my MK IV SE and its 6GX6/6GY6 strap-on pentode. They're not quite perfect yet, but they seem to do everything well, as in no musical style gets annoying after a couple of songs (as it often does when I'm testing more spiky or grainier tubes). And as is often the case during burn-in, the bass seems to be settling in a little.
> 
> Out of curiosity, which brand did you go for? Actually dual labeled? Thank for the pic of the 6EW6 tube; pics really are valuable when you go tube hunting yourself.


 
   
  GE, 6GX6/6GY6 labelled (dual). Details I can report once they have arrived.


----------



## mab1376

I ordered a pair of Raytheon 6GX6/6GY6, i'll report back on the sound once i get them.


----------



## Acapella11

Ahh, the power tubes 
   
  I found an informative post on the diyaudio forum from a member called dotfret respective 6N6P tubes. It explains some nice bits as the 6N6P super tube, some about the impulse tubes and the 6N30P tubes:
   
   
  Quote: 





> Neither type was designed for audio applications, but they are eminently suited to audio use.
> 
> The 6n6p was the original "supertube". The Russians discontinued production and introduced a range of valves, including the 6n28p and the 6n30p, to replace it in their standard applications.
> 
> ...


----------



## mordy

About heat dissipation:
   
  The EF95 family tubes I use do not generate that much heat, but I remember burning in some EF92 type tubes that made the whole amp really hot to touch.
  As mentioned, the amp runs hotter when the ambient temperature is higher in the summer. As for myself, I put up my amp on metal Hi-Fi cones to allow for cooling through convection - seems to work fine.
   
  I remember one post from Australia who said he used a fan from a PC to blow on his amp. It seems to me that you could take out the power supply from any old computer and also take out and connect a fan from the same PC to cool the Little Dot amp. Any suggestions, or did anybody try this?


----------



## inphu510n

Quote: 





mordy said:


> About heat dissipation:
> 
> The EF95 family tubes I use do not generate that much heat, but I remember burning in some EF92 type tubes that made the whole amp really hot to touch.
> As mentioned, the amp runs hotter when the ambient temperature is higher in the summer. As for myself, I put up my amp on metal Hi-Fi cones to allow for cooling through convection - seems to work fine.
> ...


 
  I noticed the extra heat dissipation as soon as I put in EF92's. My 6N6Ps easily burn skin with these higher powered tubes.
  When I put in the 6GX6/6GY6 tubes the heat was worrying. I also noted that the filaments in my power tubes were much brighter as well.
  I really haven't burned in any of the tubes that I own but in my experience, with my setup the 6GX6 sound signature was not better or worth the risk of heat damage.
  I'm also not trying to drive orthos and my cans are 64ohms so 450ma tubes are overkill.
   
  I'm thinking about taking some vinyl coated wire (similar to coat hanger wire) and bending it around the back and sides of the transformer cover, then upward in a way that would hold a very quiet 80mm computer fan above the tubes. Power is easily supplied using a 12v wall adapter.
   
  So far I still really enjoy the tubey goodness of the Ultron EF92's but the 1964 RCA 6676/6CB6A tubes I received today are quickly becoming my current favorite.
  The 6676 are quite clear and the bass is excellent. Slightly less bass loudness than the Ultrons but that's a good thing because it can be fatiguing with those tubes. Their overall tone is simply awesome for vocals. Voices are very direct and detailed. Overall detail is very good though sometimes the highs can be harsh. Dimensional placement is good but no other tube so far has come close to the 6J1P-EV's 3D effect. At some point I'm going to order a few pairs of 6N6P-IR power tubes and hopefully those can accent and extend the perceived placement of sounds.
   
  I've got a few more on the way, GE 6CB6A and soon GE & RCA 8136 tubes.
   
  Seriously, Audiofanboy deserves a lot of credit. He's put so much time into research and listening that it's fundamentally changed this thread from "what's available in the EF95/EF92/EF91 tube families?" to "what tubes can we use with LD amps?". Spectacular!


----------



## gibosi

My 6J38P-EV Russian Tubes arrived today! According to their datasheet, this tube is configured like an EF95. I am also expecting some 6BC5/6AG5/6J3Ps which are also configured like EF95s this week, so will change jumpers and start burning these in...


----------



## Audiofanboy

Great gibosi, tell us what you think of those 6J38P with no western equivalents, when you get a chance!
   
  Meanwhile -shameless plug-  I finally got around to posting a classified for a pair of NOS 6N30P-DR from 1980 and a pair of lightly used EH 6H30Pi Gold pins, if anyone's interested.
http://www.head-fi.org/t/654419/supertubes-matched-nos-6n30p-dr-electro-harmonix-6h30pi-gold
   
  Now, back to topic, I finally got my -currently- last order of tubes in today, a whole bunch of Russian 6J3P-E, from three different years: 1972, 1977 and 1978. Each with the best military quality control, OTK1 and <> rhombus. 6AK5 setting, currently burning in. First impressions are a little ambivalent, but I can definitely hear a specific house sound with quite a bit of warmth compared to some of the slightly sterile tubes I tried this week. With so many interesting tubes and so little time to actually listen to them, it's a little difficult to give unbiased feedback...
   
  Anyway, meet our new friend, the 6J3P-E


----------



## MIKELAP

Quote: 





inphu510n said:


> I noticed the extra heat dissipation as soon as I put in EF92's. My 6N6Ps easily burn skin with these higher powered tubes.
> When I put in the 6GX6/6GY6 tubes the heat was worrying. I also noted that the filaments in my power tubes were much brighter as well.
> I really haven't burned in any of the tubes that I own but in my experience, with my setup the 6GX6 sound signature was not better or worth the risk of heat damage.
> I'm also not trying to drive orthos and my cans are 64ohms so 450ma tubes are overkill.
> ...


 
  I to received some tubes today 1958 hit ray 6cb6a  and i agree with you they were suprising very punchy clean tubes


----------



## mab1376

Really curious to hear your thoughts on the 6J3P-E and 6J38P-EV!
   
  Keep up the good work everyone!


----------



## Acapella11

Update to the Sylvania 6EW6 tubes
  
 My fresh wind of LD tubes comes in doses, so I have some time to spend with the Sylvania 6EW6 tube, which I quite enjoyed. The tube is burned in now for approximately 24 hours. It got clearer in terms of reproduction and cleaner in terms of noise floor. The background is not as black as military grade tubes but since it got reduced with the burn in process, it is low enough to not bother me. The tube is slightly microphonic.
  
 General signature
 When compared to the CV4015, the 6EW6 is quite a bit louder and on a similar level to my CV4014 (EF91). Compared to both, the tube is warmer, sounds fatter. Just for clarification, CV4014 and CV4015 are surely more on the analytical side of the sound signature band. The 6EW6 is not overly warm though and quite transparent. Overall, the tube is well balanced in terms of frequencies. 
  
 Treble
 Extended but also tubey smoothness. I very much like the treble. No sign of grain. Generally, I also like the "crunchy" type of treble, which this is not -  you start hearing it, you think that you are not missing anything and just flow with it.
  
 Mids
 Now comes a tube classical phrase: The mids are lush. They are very enjoyable, also because of the addictive but not overly mellow warmth.
  
 Bass
 Good presence and articulation, goes deep as well.
  
 Stage
 The stage is smaller than for CV4014 and CV4015 tubes, on which - in comparison - instrument separation is better and more organized. With the 6EW6 everything moves a bit closer together but each instrument gets a more pronounced appearance. The sound is relatively forward, but not "in your face". The CV4015 imaging is better but then it also is the best I had so far.
  
 Summary so far:  Warmer than CV4014 and 4015 - no analytical signature, still revealing, very musical, non-fatiguing and well balanced.
  
 Exciting times.


----------



## gibosi

After burning in all day, I am pleased to report that these 6J38P-EVs did not explode! lol. In fact these are very nice tubes. It has been quite some time since I have listened to the classic Voskhod 6J1P-EVs, so I dug them out to do a quick A/B. It seems that 190mA gives little if any more volume than the Voshkods. The volume sounds about them same to me. And the sound signature is also very similar, strong punchy bass and warm vocals, again very nice. 
   
  I almost want to say that if you have the Voskhods and you are happy with them, it might not be worth getting these tubes. Having said that, with all the tubes I have been listening to recently, I think I am getting a little burned out.... In the end, for $1.50 a tube (10 tubes for $15.00 plus shipping) I have no regrets. These are very high quality tubes.
   
  I notice they have the same polished silvery metal pins as the Voskhods... Can someone tell me what these pins are made of?
   
  Tomorrow I have some Mil-spec 6BC5/6CE5s coming:  Sylvania (1974) and GE (1962)


----------



## zedmeco

this really is a great thread. I have been trawling these pages for a while now and have now got more tubes then I think I will ever need, the line up is like this:
  [size=small]6J1P-EV EF95 6F32 Voskhod [/size]
  [size=small]Matched Pair Tung-Sol NOS/NIB 6AJ5/6ak5/6J1/EF95[/size]
  [size=small]matched 6J1P-EV (EF95 6AK7) Gold-Platinum grid[/size]
  [size=small]GE 5 Stars 5654 6AK5W[/size]
  [size=small]Novosibirsk 6H6P-I[/size]
  [size=small]M8100 CV4010 MULLARD 6AK5 EF95 E MATCH PAIR[/size]
  [size=small]Sylvania JHS 6AK5 Matched Pair[/size]
  [size=small]Voshkod 6ZH1P-EV[/size]
  [size=small]and I am collecting these from the post office today:[/size]
MATCHED PAIR of 6J1P GOLD GRID NOVOSIBIRSK EF95 6F32 6AK5...
2x MATCHED TUBES < GOLD GRID > 6J1P 60's NOS PAIR NOVOSIB...
TESTED & MATCHED PAIR of 6N6P NOVOSIBIRSK GOLD GRID TUBES...
   
  at the moment my favourite tubes are the 6J1P-EV gold/platinum grids and the novosibirsk 6H6P-I gold grid and pins. this combination is full of detail and warmth, as I use my set up for writing electronic music, I have found the mixes done with these tubes transfers most accurately to my dynaudio bm5a studio monitors (I write with headphones out of respect for the neighbours!) 
  I found the tung sol's to have a weired back ground noise, when  I touch the amp or anywhere near it, it picks up the sound and produces it to the headphones, i think this is microphonics. I found the mullards gave me a false representation of the mix, sounding great in the headphones but leaving me lacking in the bass and the highs quite dull when checking on the monitors. the 6ZH1P-EV's are also very accurate when comparing the mix, a real joy to listen to. the GE 5stars are very similar to the mullards but i have not given them very long in the amp, maybe 10 hours, the sound just has not opened up for me. the sylvania's are nice, quite a delicate sound for my ears but again I find I cannot trust the mix. my verdict, my favourite sets have been in the amp for a while now and I trust the sound I am getting, so I wonder if it is time to lock up the wallet and live with what I have for a while. These new families are quite exciting and I am having trouble resisting another purchase but the issue with the excessive heat concerns me. thanks everyone for your contingued inspiration and keep on.. z


----------



## Makiah S

Nice, well I recently when on an INSANO tube swwping spree with my hybrid 12ua7 tubes
   
  although I've been wanting a LD tube for a while now and well I'll need something to replace the  5963 12ua7 Mullard I have in there now, basically a thick tube, they will b paired with a 250 [maybe 600ohm] Dt 880, so as of right now my 250 ohm likes the mullard... ALLOT, I have 2 pairs of RCA Clear Tops and they sound AMAZING... but not with the byer, the already mellow and delicate beyer sounds a little empty on the clear tops [unlike my Mad Dogs and dt 990s] so again the byer already has wonderful airy trebele and super epic tight bass, all it needs it lush sexi mids any tips on a tube that would compliment  
   
  In addition since I'm used to Hybrid Tubes, should I jump right to LD4 or maybe try the LD3 first


----------



## Brooko

Quote: 





mshenay said:


> In addition since I'm used to Hybrid Tubes, should I jump right to LD4 or maybe try the LD3 first


 
   
  Considering you have the Beyers (especially if you are going 600 ohm eventually), and given that the price between the MKIII and MKIV is only ~ USD 100, I'd just save a little longer and go MKIV.  You know you'll end up there eventually anyway 
	

	
	
		
		

		
			




   
  IMO it pairs really well with the Beyers (also with my Senns).  The IVSE would be worth it as well.  I have the IV but eventually wound up with the upgraded 6H30PI gold pin anyway .......


----------



## Audiofanboy

Here is my daily update. I put in the 6J3P-E for burn-in and tested them again after about 10h (which imho is enough to have a feel for the "tone" and capabilities of a tube, even if the bass might still improve and highs might tame a bit, and other minute improvements; I just can't justify burning in every mystery tube for 50 hours...).
   
  I would say the 6J3P-E is a bit cozy and warm, it sounds kind of like a higher gain warm 6AK5. Treble is pleasant and not too spiky, but not rolled off either. Mids are a bit grainy, lush, warm, and could use a bit more microdetail and separation. Bass is you typical average good tube-y bass, with a slight lack in punch, but OK for most music. Overall, a solid all-rounder *C+* grade tube (at this point I think I need some objective grading system, as random words and comments just don't enable real comparisons), good overall but never excellent, and a bit too mellow for my tastes. This being said, I could imagine these tubes being very nice for listening to singer songwriter type music where you don't want too much microdetail, but warmth and mellowness with more grain, kind of like a more powerful M8100 with less instrument separation and detail. And they might improve after 100+h of burn-in the Voskhods, but that shouldn't add detail or change the tube's performance.
   
  After the -unburnt-in- GE 6AG5 that were way below these 6J3P-E, I'd say I might just try one last special quality/military 6AG5 and be done with testing this tube family for the time being -or until someone else makes an awesome breakthrough.
   
  Speaking of "grading" tubes, I would tend to grade on an relative scale not an absolute one, meaning that an A++ tube that suddenly pops up would mechanically make all the other tubes go down one grade and become my _de facto_ new A+ reference. So right now, for me, the GEC CV4014 would be my A+ tubes, and my Mullard CV4015 would be an very solid A as well (probably A+ in some setups). Voskhod 6J1P-EV would have been a solid B+ tube and the Mullard CV4010/M8100 an A- (B+ for electronic music). The best Mullard M8083/CV4014 would hover between an A- and a B depending on the version tried, there's just way too much variety in that family.
   
  After 9-10h of burn-in, the Military GE (non-JAN) 6EW6 tubes seem to have matured to the point where giving an opinion would be reasonable. These are some very good tubes, considering they're not a special quality or military tube (which doesn't exist in that family). Bass slams down on you in a powerful way and gives music a body and impact that is very enjoyable, it extends enough that wouldn't think anything is missing, not especially fast but not slow either, just visceral and well grounded. Background is not quite as black and empty as my best tubes; instruments, while very well rendered, don't stand out as clearly as they could, but they are all there, just sort of in each others face (like somewhat superimposed, but not in a bad way and still each audible). Soundstage is your average 300mW+ heater current large stage, not a mile-large like some EF91s but enough to not sound too squeezed, and is noticeably extended vertically, and very good in depth -big 3D bubble- in your head kind of stage but never in your face; the sense of space is definitely there, but again not quite as much or well as the best tubes, but very very close. Mids are ever-so-slightly warm but not as much as a GEC CV4014, I'd say in between these and the CV4015 or the more recent analytical 8136. The transients scream of realism and almost reach the best of the best, decay is just a tad slower than my fastest -analytical- tubes, but that's not necessarily a bad thing. Highs are well extended and sound like "it's all there" without ever being grating, airy without sounding silly or surreal. Overall, this an excellent tube, which I'm starting to think may still evolve a bit with an extra 10h of burn-in; a very solid *A* tube imo, that might get an extra point at 50 hours.
   
  I'll try to *finally* formulate an objective opinion on the 6CB6A/6676, 8136, 6GX6/6GY6 at some point, and the 6GM6 when I get a chance to actually plug them.


----------



## mab1376

Quote: 





zedmeco said:


> this really is a great thread. I have been trawling these pages for a while now and have now got more tubes then I think I will ever need, the line up is like this:
> [size=small]6J1P-EV EF95 6F32 Voskhod [/size]
> [size=small]Matched Pair Tung-Sol NOS/NIB 6AJ5/6ak5/6J1/EF95[/size]
> [size=small]matched 6J1P-EV (EF95 6AK7) Gold-Platinum grid[/size]
> ...


 
   
  So far my inventory is:
   
  Western Electric 403b
  LM Ericsson 403b
  Mullard M8100
  Mullard M8161 x2 (EF92)
  Telefunken 6AK5W
  Raytheon 6AK5
  Russian Military 6X1Π-EB
  Voshkod 6ZH1P-EV
  Tung-Sol 6AK5W x2
  Tung-Sol 6AJ5
  GE 5-star 5654W
   
  On the way:
  GEC CV4014
  RAYTHEON 6GY6/6GX6
   
  Power Tubes:
  6N6P-IR
  Electro Harmonix 6H30Pi
   
  I'm really liking my Tung-Sol's with the 6n6p-ir tubes! can't wait for my GEC CV4014 tubes that have gotten so much praise on here.


----------



## Makiah S

Quote: 





brooko said:


> Considering you have the Beyers (especially if you are going 600 ohm eventually), and given that the price between the MKIII and MKIV is only ~ USD 100, I'd just save a little longer and go MKIV.  You know you'll end up there eventually anyway
> 
> 
> 
> ...


 
  Hanks, that's what I've been told and yea might as well save up the Extra $50 or so it takes


----------



## Audiofanboy

It's finally Saturday, so I've had time to reach some conclusions on my most recent tubes.
   
  First the *GE 6GM6*: These are comparable in gain with the 6AK5, so very low for a 400 mA filament current. They are extremely noisy, with actual ssshhfffSSSjjjFff sounds coming in randomly and loud enough to be heard during the music. They have fast decay, great instrument separation, PRaT and excellent transient response, with a nice realistic studio-size 3D soundtstage. Great treble with excellent instrument definition and positioning, things come at you from logical places in the mix and sound great. Mids are neutral, which I don't often get with tubes, no too tube-y not analytical either, and not natural but neutral. Bass might be a bit lacking in power though and doesn't have the weight and punch it could, but it is fine and doesn't distract from anything. Excellent *A* grade tube (borderline A+) that will forever be marred by intense random noise issues that didn't go away after 13h of burn-in, and that I will unlikely be using because of those occasional loud airy instrument-like noises and the more constant random less loud Psschftt noises all over the channels.
   
  You can so tell these are consumer grade tubes it is not even funny. I suddenly realize how accustomed I've grown to hearing delicious mil spec/spec quality tubes and why it is a bit purposeless to get regular tubes (is this the kind of crap noise people had to listen to with consumer grade tubes back in the day?). Alas, no military or special quality version of the 6GM6 exists, just like for the 6EW6 where I was lucky enough to find them in a military box with the military green GE ink on the tubes, but still labeled essentially plain Jane "6EW6" not JAN or any special quality number. No more consumer grade tubes for me...
   
*GE 6GX6/6GY6*: A bit grainy, not as in noisy but a slight coarseness of sound that reminds me of dithering (adding random noise to sound or images to give the illusion of more detail, usually to make crappy old recordings sound better). Slightly in your face sound, opposite of watching a band play way in front of you. Quite detailed, sense of power in the mids, airy slightly grainy highs (explained earlier). Pretty punchy bass, not the best but very good and powerful, could extend a bit lower. Average decay, not slow nor too fast either. These tubes scale well with the quality of recordings. On good ones, they have an enveloping sound that's all 3D-like around your head/face (as it is still a bit forward), on poor ones, they sound kind of like an engineer's attempt at restoring music from old tapes. Overall, again, an excellent tube that came out of nowhere, I'd say *A-* grade, just because it sounds a little funny and extreme on some songs, a little "analog" sounding actually, that would be the right word. That ever-so-slight invisible graininess, warm and rounded bass sound that makes music sound like it's being played from reel to reel tapes, which I'm sure a lot of you would like! So try 'em if you like that sort of thing.
   
  I was going to review my 8136 a bit more thoroughly today but one of them just crapped out on me... That's the second one too, they make Pfft Pftt Pffffttt sounds that don't go away. Oh well, I still have 12 left, now I just need to find another strong one in the pile.


----------



## gibosi

I have been burning in some 6BC5/6EC5s:
   
   

   
  The GE (date code: 62-39) in the middle and the Sylvania (date code: 7452) look identical even though manufactured 12 years apart by different companies. These came in military boxes, but no JAN or W designations. The internal structure of the GE on the left (date code 0-13 - 1960? 1970?) is very different than the others but unfortunately they were packaged in a new plain white box so no additional information.
   
  Unfortunately, I woke up this morning with a flu-like virus and am just not up to listening critically to these now... Later....


----------



## gibosi

Quote: 





audiofanboy said:


> First the *GE 6GM6*: These are comparable in gain with the 6AK5, so very low for a 400 mA filament current. They are extremely noisy, with actual ssshhfffSSSjjjFff sounds coming in randomly and loud enough to be heard during the music. They have fast decay, great instrument separation, PRaT and excellent transient response, with a nice realistic studio-size 3D soundtstage. Great treble with excellent instrument definition and positioning, things come at you from logical places in the mix and sound great. Mids are neutral, which I don't often get with tubes, no too tube-y not analytical either, and not natural but neutral. Bass might be a bit lacking in power though and doesn't have the weight and punch it could, but it is fine and doesn't distract from anything. Excellent *A* grade tube (borderline A+) that will forever be marred by intense random noise issues that didn't go away after 13h of burn-in, and that I will unlikely be using because of those occasional loud airy instrument-like noises and the more constant random less loud Psschftt noises all over the channels.


 
   
  I have two pairs of 6GM6s, RCA and Sylvania, and they are very quiet, so I would guess you just got unlucky... 
   
  Otherwise, my impressions are similar to yours. In fact, I like these more than my Raytheon 6EW6s.


----------



## mordy

Dear G,
   
  In the past I have received tubes with a date code silk screened on the glass tube that was several years before the date code printed on the box. My guess is that suppliers simply took old stock and put them in new boxes for the purpose of selling them to the military. Truth is, I have tubes that are 68 years old and they perform fine, so I don't think it matters so much with a few years here or there.


----------



## gibosi

68 years old? Late WWII? That is old! This is good to know if I ever come across a quality tube from that era. Thanks!


----------



## Makiah S

Is the LIttle Dot MKIV good for Orthos? My Mad Dogs need some mo juice!


----------



## gibosi

Oh, I just realized that I had not posted 6GM6 pictures:
   
   

   
   

   
  The Sylvanias appear to have the same internal construction, but the printing is different, and one has darker smoked glass. The RCAs appear to be identical and were manufactured within a few months of each other, EA = Oct 72 and ED = Jan 73.  An added benefit is they light up nicely in a dark room.


----------



## mordy

Dear Gibosi,
   
  Here is a photo of the Raytheon 1945 6AK5 tubes that I have. They appear completely new, and are packaged in greenish felt lined paper. If anybody is interested, I would trade one pair of these Feb 1945 tubes for one pair of 6N6P-IR tubes.


----------



## Acapella11

Quote: 





> Originally Posted by *Audiofanboy* /img/forum/go_quote.gif
> 
> You can so tell these are consumer grade tubes it is not even funny. I suddenly realize how accustomed I've grown to hearing delicious mil spec/spec quality tubes and why it is a bit purposeless to get regular tubes (is this the kind of crap noise people had to listen to with consumer grade tubes back in the day?). Alas, no military or special quality version of the 6GM6 exists, just like for the 6EW6 where I was lucky enough to find them in a military box with the military green GE ink on the tubes, but still labeled essentially plain Jane "6EW6" not JAN or any special quality number. No more consumer grade tubes for me...


 
   
  This is just what I thought^^. My consumer 6EW6 also are also not that silent and inert against the environment. Do you mind posting a link or an information where you bought your military spec 6EW6? I am interested in those. Thanks in advance.


----------



## Audiofanboy

Quote: 





acapella11 said:


> This is just what I thought^^. My consumer 6EW6 also are also not that silent and inert against the environment. Do you mind posting a link or an information where you bought your military spec 6EW6? I am interested in those. Thanks in advance.


 

 Sadly, it was a one-shot auction/buy now for both my 6EW6 and 6GM6, that was the seller only inventory for those tubes, and for many miniature types in general... Again, I'm pretty sure my 6EW6 aren't mil spec, but maybe just "selected" since the box mentions your typical US government contract name and such, but nothing about a special quality or military type, or even a JAN indication. Basically plain Jane tube for the US government agencies, possibly not even intended for the military.
   
  On the other hand, I'd love to re-try some less consumer grade 6GM6 -as those were really good- provided someone finds some selected ones at least or the same kind of US government ones, for lack of JAN ones...


----------



## MIKELAP

Quote: 





audiofanboy said:


> Sadly, it was a one-shot auction/buy now for both my 6EW6 and 6GM6, that was the seller only inventory for those tubes, and for many miniature types in general... Again, I'm pretty sure my 6EW6 aren't mil spec, but maybe just "selected" since the box mentions your typical US government contract name and such, but nothing about a special quality or military type, or even a JAN indication. Basically plain Jane tube for the US government agencies, possibly not even intended for the military.
> 
> On the other hand, I'd love to re-try some less consumer grade 6GM6 -as those were really good- provided someone finds some selected ones at least or the same kind of US government ones, for lack of JAN ones...


 
  there is a seller in Montreal that i bought some tubes from, went to his shop and he tested my tubes in front of me so the guy honest  and he has  the 6ew6 and 6gm6 tubes on his site email him for details heres is link      http://www.tubebazar.com


----------



## Acapella11

There is a hunch of an observation respective the R at the end of the name of the Russian power tubes. I noticed a larger stage and deeper bass with the 6N6P-IR compared to the 6N6P-I. I think the 6N6P-I are fine tubes too, just they do not sound as "high-end" to my ears as the ones with R do.
   
  Now, Audiofanboy described that the 6H30P-EV sound flatter and not as deep bassy as the 6H30P-DR tubes do. It makes me start to think that the low noise spec (R) generally could add a vaster stage and a more U shaped type of sound, thereby adding more substance to the deepest and possibly also highest frequencies in the spectrum. This would be an interesting rule of thumb.


----------



## Audiofanboy

Quote: 





acapella11 said:


> There is a hunch of an observation respective the R at the end of the name of the Russian power tubes. I noticed a larger stage and deeper bass with the 6N6P-IR compared to the 6N6P-I. I think the 6N6P-I are fine tubes too, just they do not sound as "high-end" to my ears as the ones with R do.
> 
> Now, Audiofanboy described that the 6H30P-EV sound flatter and not as deep bassy as the 6H30P-DR tubes do. It makes me start to think that the low noise spec (R) generally could add a vaster stage and a more U shaped type of sound, thereby adding more substance to the deepest and possibly also highest frequencies in the spectrum. This would be an interesting rule of thumb.


 

 I can only speak for the -DRs but they definitely have much better upper end extension, and a much more linear and extended lower end - they are in essence very linear imo, it's the driver tubes that end up "biasing" them to a more or less U or V shaped signature. Basically, I'd say the R -low-noise- trait does exactly what it's supposed to, the lower noise level allows for much more clarity and transparency, and for micro-details (airiness and instrument separation in the highs), texture of sounds and realism of transients (mids and bass) to be that much better than their non-R counterparts. Of course, that low noise effect is more apparent the more transparent you gear is up to the power tubes, including driver tubes, but not only (software, transport, DAC).
   
  On another topic, I'll be testing a whole new range of driver tubes very soon, the *6AU6 *family of tubes to start with. Now, bear in mind *these are not natively compatible* with our LD amps; as pins 2 and 7 are inverted compared to a 6AK5 tube, so you'd have a floating cathode pin linked to nothing while a grid gets high voltage randomly.
   
  I ordered two very nice pairs of these for starters:
  - A matched pair of GE JAN 6AU6WC 6136 NOS NIB (special quality + military spec matched in a double government box, so matched in box basically (thereafter MIB), special quality 6136 etched in glass, how does that sound?)
  - A matched pair of Tektronix 6AU6A 8425A NOS NIB (controlled filament heater special type + made for industrial and computer applications, MIB matched in double Tektronix box (selected by pairs by Tek for their scopes) with Tek tags on each tube and special Tek serial numbers; made by GE, 6AU6A etched in glass; could turn out to be even better than the ones above!)
   
  Now comes the complicated part, as these are not natively compatible (yet perfectly suited for our amps), they need to be made compatible by linking pins 2 (grid 3 + shield) and pins 7 (cathode) soldering a very small wire between the pins very close to the glass so the tubes can still fit in the sockets, and then using the amp *with the 6AK5 jumper setting* or it will explode like 6AK5s on the wrong setting.
   
  This has been tested to work in practice, now the difficult part is just to find the best stable and functional way to get those pins connected. An adapter could also be an option, but I think I'll try the solder solution first, as it is not that hard and has a lower footprint between the amp and tube.
   
  If you have no idea what I'm talking about or about what pins I'm talking about or why I'm doing this in the first place, look back a few pages where I wrote a very long post with the details on what is compatible with the amp in what setting and why, and what pins do what on compatible tubes. I'll also be reporting -I assume with pictures- as soon as I get to try this myself (I tried and succeeded in soldering pins together on a dead tube but it'll take me a few days to have my 6AU6 with me to test on).
   
  I anybody else wants to try this, I'd suggest staying away from all the basic types of 6AU6, as they are supposed to be very microphonic and noisy, especially the plain GEs, says Google. So, I'd go directly with the best special quality and or (if you can get both, why not?) military specs types, which really aren't that expensive anyway, or better yet get them MIB if you can find them.


----------



## gibosi

I currently  have a pair of consumer 6AU6s that I am working with. First, I tried connecting the pins with standard 24 gauge hook-up wire, but the wire was too thick. It was often necessary to rock the tubes back and forth to get all the pins connected. Lots of popping and crackling!! Not good!!
   
  I am now using 30 gauge Kynar silver-plated wrapping wire. Unfortunately, the tube pins are too thick to be able to use a wire wrapping tool, however, as this wire is very fine, the fact that my tool has a wire-stripper built in is very convenient.
   
  A picture of the 30 gauge wrapping wire and my first attempt with 24 guage hook-up wire:
   

   
  As you can see, this is very fine wire.

   
  And now a picture of the 30 gauge on the tube:
   

   
  This wire is so fine that the tube seats normally. No problems. 

   
   As these are plain 6AU6s, I didn't want to bother with sanding the pins and soldering, but intend to do so when my good tubes finally arrive. For now, the mechanical connection is holding up well and everything is good.
   
  I haven't had much time to listen, but from what I have heard so far, I think these are going to be winners.


----------



## pallentx

Quote: 





audiofanboy said:


> Meanwhile, I think I've made sense of this whole jumper business, pin out, and why some tubes are compatible or not in the LD MK III/IV, after reading through a number of datasheets (that I barely understand), other google sources, the pics of the LD amp PCBs on the LD website, and this document on google, that finally helped me makes sense of the whole thing.
> 
> http://www.kaponk.com/~yanyong/ETF06TS.pdf (pages 11 onwards)
> 
> ...


 
  You sir, are a gentleman and a scholar.
   
  I didn't get all of that, but after reading http://www.vacuumtubes.net/How_Vacuum_Tubes_Work.htm, I at least know what universe you are in.


----------



## mab1376

So I got my GEC CV4014 tubes today. Changed the jumpers and plugged them in and the left channel sounded dull, a few moments later heard the super loud pig squeal type noise they nearly deafened me. I'm pretty sure the jumper is just a little mangled from the pliers I used, but jeez; that friggin' hurt.
   
  This was with the 6N6P-IR power tubes, with the 6H30PI tubes it just stayed muffled and never went all crazy like that.


----------



## Audiofanboy

Quote: 





mab1376 said:


> So I got my GEC CV4014 tubes today. Changed the jumpers and plugged them in and the left channel sounded dull, a few moments later heard the super loud pig squeal type noise they nearly deafened me. I'm pretty sure the jumper is just a little mangled from the pliers I used, but jeez; that friggin' hurt.
> 
> This was with the 6N6P-IR power tubes, with the 6H30PI tubes it just stayed muffled and never went all crazy like that.


 

 The only reason I could think of for this to happen is that, indeed, the jumper did not strap pin 7 (grid 2, pretty important, unlike grid 3, the suppressor grid) to pin 6 (aforementioned grid 3) and pin 5 (anode), which would mean that the screen, grid 2, was just floating in there accumulating god know what kind of potentials, that eventually made that squeal that nearly deafened you. On the other hand, I see no reason why the power tubes would have an effect on this; if anything the 6N6P-IR are pretty much made for this kind of torture (pulse) so if the power tubes had an effect, it should have been the other way around.
   
  To solve the jumper issue, I use extended computer jumpers that have an extra tab to hold them, and glued some matches (without the flammable part) to them so that they poke out ever so slightly out of the holes in the amplifier. Saves me from massacring them with pliers every time...


----------



## Acapella11

For changing jumpers:
   
  http://www.ebay.co.uk/itm/VETERINARY-8-ANGLED-TWEEZERS-200mm-SURGICAL-INSTRUMENT-/160909646601?ssPageName=ADME:L:OC:GB:3160
   
  =)


----------



## mab1376

Interesting info, I did clean the contacts with deoxit before installing the tubes since the pins were a tad blue. I guess it's possible one of the pins had poor contact due to all the rolling I've done.
   
  I'll definitely look into those tweezers, thanks for the link!


----------



## mordy

Hi folks,
   
  In order to prepare for a set of 6CB6A tubes that I ordered, I decided to install a set of Mullard EF92 tubes. I dread changing the jumpers, and sure enough the assorted long nose pliers I have were hard to maneuver and I dropped one jumper. Inside the LD MkIII. Luckily, I was able to shake it out. Then I thought of using a stainless anti static tweezers that I had. (See link below). This turned out to be a good move, and I was able to change the jumpers very easy with the aid of a flashlight,
   
  http://www.meritline.com/high-precision-anti-static-stainless-steel-tweezers---p-43059.aspx
   
  Today these sell for $2.99, but I paid 69c, and I have seen them even cheaper on sale by Meritline. This is a reputable company, and I have bought from them many times. Customer service is very good, and their sale prices are very inexpensive, and most items are free shipping. You can check out their daily deals every day; the tweezers go on sale often.
   
  One more question: What is the difference between the CV4015 and my Mullard EF92 tubes?
   
  And speaking of power tubes, a new listing appeared today on EBay of what seems to be gold grid 6N6P-IR tubes. A little bit pricey at $24 each including shipping. In the past I bought my gold grid 6N6P tubes from this guy in Siberia but these new listings are much more expensive.


----------



## Audiofanboy

Quote: 





mordy said:


> Hi folks,
> 
> In order to prepare for a set of 6CB6A tubes that I ordered, I decided to install a set of Mullard EF92 tubes. I dread changing the jumpers, and sure enough the assorted long nose pliers I have were hard to maneuver and I dropped one jumper. Inside the LD MkIII. Luckily, I was able to shake it out. Then I thought of using a stainless anti static tweezers that I had. (See link below). This turned out to be a good move, and I was able to change the jumpers very easy with the aid of a flashlight,
> 
> ...


 

 Mullard EF92s are consumer grade tube, whereas CV4015 are the military version of the M8161, which are the a special quality EF92. They're also called 6065, and are the successor of the CV131, an older special quality EF92, also called 6CQ6. It gets very confusing for some tubes...
   
  I thought all 6N6P-IR had "gold grids"? Or gold-platinum whichever. They have been getting more expensive on fleebay lately (all things considered) at $25+ a pair, and without that many offerings.


----------



## junkimchi

Has anyone ordered tubes directly from Russia before? I ask because I purchased a set of tubes from a high rated seller on Ebay almost a month ago but still didn't arrive yet (Russia to USA). Googling the issue it seems like there is a customs delay in Russia but just wanted to ask here if anyone has ordered from Russians before.


----------



## gibosi

Quote: 





junkimchi said:


> Has anyone ordered tubes directly from Russia before? I ask because I purchased a set of tubes from a high rated seller on Ebay almost a month ago but still didn't arrive yet (Russia to USA). Googling the issue it seems like there is a customs delay in Russia but just wanted to ask here if anyone has ordered from Russians before.


 
  In my experience it can take as long as 40 days to get tubes from Russia, Romania, Lithuania, Georgia and similar countries (to the US). So it is likely that there is nothing to worry about. This is "normal".
   
  If you have a tracking number, this can often be a useful site to track packages:
   
  http://www.17track.net/index_en.shtml


----------



## Chodi

Quote: 





junkimchi said:


> Has anyone ordered tubes directly from Russia before? I ask because I purchased a set of tubes from a high rated seller on Ebay almost a month ago but still didn't arrive yet (Russia to USA). Googling the issue it seems like there is a customs delay in Russia but just wanted to ask here if anyone has ordered from Russians before.


 
  I've ordered tubes off ebay from Russia twice without any problem. Delivery was slow but the tubes arrived both times and no problems.


----------



## MIKELAP

Quote: 





junkimchi said:


> Has anyone ordered tubes directly from Russia before? I ask because I purchased a set of tubes from a high rated seller on Ebay almost a month ago but still didn't arrive yet (Russia to USA). Googling the issue it seems like there is a customs delay in Russia but just wanted to ask here if anyone has ordered from Russians before.


 
  i ordered 2 pairs of Tesla 6f32v tubes on the 19 of february and they left Moscow today the 12 marsh  so i expect to get them in a week or so.


----------



## junkimchi

Wow holy crap it took one month just to get out of Russia? Man it is true what they say about Soviet Russia.


----------



## Acapella11

6N6P-IR for $13 / piece + $ 8.00 for shipping:
   
  http://tubes-store.com/product_info.php?products_id=519
   
  My old total accumulated to $36 for both tubes and shipping because I bought them for + $2 / piece with the original box.
   
  I have to check for the metal of the grid.


----------



## Audiofanboy

I've been silly... Why bother soldering a wire on very-hard-to-solder-on-because-oxidized tube pins or even wrap a wire around to link two pins semi-permanently when you can just... bridge two hole in the socket without soldering anything. Just by dropping a small |__| shaped wire into the holes (stranded copper wire btw, solid core wouldn't work here, it has to be able to ease around the pins) that will make perfect contact between the tube pins, wire, and socket holes over most of the length of the pins, and be flat enough that the tube rests perfectly in its socket barely higher than usual and perfectly vertical.
   

   

   
_Voila_, so easy a mod even a cave man could do it, and now you have the "schematics" too. That basically makes your amp compatible with all 7BK base tubes like the 6AU6. Nothing permanent, very good mechanical contact (stranded copper stuck between tube pin and socket hole wrapped around a long side of the pin, very hard to get a failed contact). Just chop up two pieces of wire and bring them down slowly in the holes with nose pliers or whatever. Wires need to fit nicely in the holes to avoid bad contact, or worse, contact with other pins. Just insert the tubes on top of that trying to make somewhat sure the wires don't like fly away from the tubes socket that very second, you never know. Only problem is that when you pull the tubes out, the wire has a 50% chance to come out too. Then again, you should probably re-straighten the stranded copper and reinsert the wires properly with every tube change, just in case; hardly very difficult. I used 26 AWG OFC copper wires btw (from a leftover Mogami 2893 quad cable).
   
  Edit: Yeah, definitely take the mod wires out when you change tubes and re-twist the stranded copper back into a straight shape before reinserting the wires in the socket and then the new tubes. When I changed tubes the second time I tried this, the wires only popped out on one side and stayed in on the other, so I only re-twisted the one that popped out: bad idea, both tubes worked fine until I tapped the amp very lightly to check for microphonics and the tube on the wrong side went SHHHHH on me. Pulled tubes and wires back out, put everything back in properly, no problems. Then again, the pins were pretty dirty too -should have cleaned them first- which was probably not helping to make contact with the wire. At least it shows this "mod" won't make your amp explode or anything (you'll just get a floating cathode and lots of noise if the contact isn't perfect).
   
  I tested that "mod" of sorts with "regular" tubes first, and it worked perfectly. *6AK5 jumper setting* *and do NOT do it with EF92/91 tubes* (as pins 6 and 7 are inverted), but on any 7CM base tubes (6CB6, 6DK6...) it works by strapping grid 3 and cathode together (instead of using the EF92 jumper setting to strap grid 2, grid 3 and anode together), while grid 2 is still strapped to the anode. So, it can also be a good mod for those of you that hate changing jumpers with a passion. Note that for EF92/91 tubes, one could also imagine placing a small wire between pins 6 and 7 to strap grid 2, grid 3 and anode together by hand and stay in the 6AK5 jumper setting all the time -if you really hate jumpers that much. Strapping grid 3 to either anode (EF92 jumper) or to cathode (this "mod") might yield sonic differences -note that the shield is usually connected to grid 3 so connecting the shield to either anode or cathode might also make a difference in noise rejection- or might not, feel free to try while you wait for your 6AU6 tubes you know you'll end up ordering  .
   
  Now that the amp is "compatible" with 7BK base tubes, and since I just got my 6AU6 in the mail, it's time to test some new tubes!
   
  GE JAN 6AU6WC 1978 matched in box NOS NIB
   

   
  Tektronix matched in box GE 8425A/6AU6A 1964 NOS NIB
   

   
  The Tek matched 8425A are currently burning in for the workday. From just testing them after 15 minutes, I can say these are incredibly clean and musical, and natural and detailed with a black black background and possibly the best clarity I think I've ever gotten out of this amp. They have a very similar structure (shield, grids, top, getter flash) compared to the GE 6GX6/6GY6 I have, which is interesting. What is immediately apparent is how awesome the imaging is on these. The singer is right here, smack in the middle of the scene, on the stage or in the studio, singing with all the qualities and inflections of his/her voice, truly impressive! Only the bass could have a bit more punch and slam at this point, but that's probably my headphones more than the tubes. I would be very surprised these don't come out as A+ tubes after burn-in -as I had speculated they would. Try 'em, they're dirt cheap anyway, and their clarity and imaging might be even better than the beloved CV4015 -which is no easy feat.


----------



## duncan1

Hello audiofanboy.Bit puzzled about the EF92   This is a VM RF tube used in radio/wireless receivers the VM means the gain will vary with signal -used to stop overloading of signal rather than a fixed gain Its specially made for that use.   .EF91 is okay
  didnt know it was  being used for audio.
  Strapping GRID 2 to Grid 3 ? grid 2 usually carries a high voltage like the plate voltage.
  If you were using it as a triode then G2 would be strapped to the plate-pin 5 and yes  G3 can be strapped to the cathode pin 2 to pin 6.
  6AU6 can be used in audio.


----------



## Audiofanboy

Quote: 





duncan1 said:


> Hello audiofanboy.Bit puzzled about the EF92   This is a VM RF tube used in radio/wireless receivers the VM means the gain will vary with signal -used to stop overloading of signal rather than a fixed gain Its specially made for that use.   .EF91 is okay
> didnt know it was  being used for audio.
> Strapping GRID 2 to Grid 3 ? grid 2 usually carries a high voltage like the plate voltage.
> If you were using it as a triode then G2 would be strapped to the plate-pin 5 and yes  G3 can be strapped to the cathode pin 2 to pin 6.
> 6AU6 can be used in audio.


 

 Yes, if anything the EF92 is kind of the odd ball in the natively compatible tubes from looking at the datasheet. But from experience, it works very well and sounds great; gain isn't huge but it has good authority at all volumes imo. EF91 are obviously not really meant for audio and I haven't seen many other examples where they've been used triode strapped in audio circuits; but again they work very well and have very high gain, which I like.
   
  Strapping grid 2 and 3 together and linked to nothing else would be a problem, as grid 3 is not supposed to receive the kind of high voltage grid 2 gets in pentode mode. But triode strapped by linking grids 2 and 3 and anode -which is what the amp natively does with the EF92 jumper setting- it makes sense and just has both grids at the same potential as the anode. Pins 5 and 6 are hardwired together in the amp anyway (which would mean anode and g3 for EF91/92 and wouldn't really work properly without pin 7 = g2 linked as well) and the amp only works with triode-strapped pentode. I just tried strapping g3 to the cathode by hand to triode-strap the tubes differently, and to make the amp compatible with 7BK base tubes like the 6AU6.
   
  The 6AU6, unlike many tubes I tried in the last 2 weeks, is actually good and not rare in audio circuits, and actually has triode curves in its datasheets in the first place; so we can't be that far-off trying it in LD amps. It also has characteristics that make it pretty close to a 6AK5 triode-strapped in terms of gm with a similar circuit biasing, and I can vouch for the fact that it works pretty well right off the bat! In amps wired a bit differently, the 6AU6 is often considered a possible "replacement" for a 6AK5, from what I've read.


----------



## MIKELAP

Quote: 





audiofanboy said:


> I've been silly... Why bother soldering a wire on very-hard-to-solder-on-because-oxidized tube pins or even wrap a wire around to link two pins semi-permanently when you can just... bridge two hole in the socket without soldering anything. Just by dropping a small |__| shaped wire into the holes (stranded copper wire btw, solid core wouldn't work here, it has to be able to ease around the pins) that will make perfect contact between the tube pins, wire, and socket holes over most of the length of the pins, and be flat enough that the tube rests perfectly in its socket barely higher than usual and perfectly vertical.
> 
> 
> 
> ...


 
  Are these 8425a compatible with a mk3 or mk4 or both ? Thank you


----------



## Audiofanboy

Quote: 





mikelap said:


> Are these 8425a compatible with a mk3 or mk4 or both ? Thank you


 

 Both and probably the MK II and I+, basically all the LD amps made for 6AK5 type tubes. Again though, *not natively*.
   
  There are no differences in design between the MK III and IV as far as I can tell from the pictures of the circuit boards on the LD website, just different and better/larger components, but similar schematics.


----------



## gibosi

Quote: 





audiofanboy said:


> I've been silly... Why bother soldering a wire on very-hard-to-solder-on-because-oxidized tube pins or even wrap a wire around to link two pins semi-permanently when you can just... bridge two hole in the socket without soldering anything. Just by dropping a small |__| shaped wire into the holes (stranded copper wire btw, solid core wouldn't work here, it has to be able to ease around the pins) that will make perfect contact between the tube pins, wire, and socket holes over most of the length of the pins, and be flat enough that the tube rests perfectly in its socket barely higher than usual and perfectly vertical.


 
   
  What a great idea! And while I don't have any suitably small stranded wire, the 30 gauge solid core wrapping wire I have is also working fine for this purpose.
   
  And I agree about the sound of these tubes. I have plain-Jane used GE 6AU6s and I am amazed at what I am hearing. And the 6136s and 8425As I have coming might be even better? 
   
  Oh, *MIKELAP*, I can attest to the fact that all this is working fine in a 1+.


----------



## MIKELAP

Quote: 





gibosi said:


> What a great idea! And while I don't have any suitably small stranded wire, the 30 gauge solid core wrapping wire I have is also working fine for this purpose.
> 
> And I agree about the sound of these tubes. I have plain-Jane used GE 6AU6s and I am amazed at what I am hearing. And the 6136s and 8425As I have coming might be even better?
> 
> Oh, *MIKELAP*, I can attest to the fact that all this is working fine in a 1+


 
  Thanks for  your imput it is appreciated . actually i did not realize you had a mk4 tough it was a 3 at the same time i was wondering if i ever bought a mk4 if my tubes would work with this amp apparently they do but does the mk4 have additionnal tubes it can use or it is the same tubes as mk3 While im at it is there a big sound difference between the mk3 and mk4se. Thanks again.


----------



## Audiofanboy

Quote: 





mikelap said:


> Thanks for  your imput it is appreciated . actually i did not realize you had a mk4 tough it was a 3 at the same time i was wondering if i ever bought a mk4 if my tubes would work with this amp apparently they do but does the mk4 have additionnal tubes it can use or it is the same tubes as mk3 While im at it is there a big sound difference between the mk3 and mk4se. Thanks again.


 

 The MK IV ( and IV SE) was designed from the get go to work with 6H30P tubes, whereas the (original) MK III was not. That is no longer true as the MK III works quite well with 6H30P tubes now. So, as far as compatibility goes, MK III & IV are the same. I've never had the chance to listen to a MK III unit but I assume there is a difference between the MK III & IV, and in turn between the MK IV & IV SE (if you look at the circuit board pictures on the LD website, if anything just at the caps which have a different size on the IV). That added to other hardware must surely amount to some degree of difference, like maybe the last 30% or something, but surely the tubes you use would account for the first 70% or so of performance. All I know is that I get great performance out of my MK IV SE with maxed out power tubes and delicious driver tubes  .


----------



## GrindingThud

Mine must be on the same plane. This site works well if you have a tracking number and don't mind google translate at times:
http://www.russianpost.ru/rp/servise/en/home/postuslug/trackingpo
Be patient...it will come.



mikelap said:


> i ordered 2 pairs of Tesla 6f32v tubes on the 19 of february and they left Moscow today the 12 marsh  so i expect to get them in a week or so.


----------



## mordy

Hi Folks,
   
  Here is an answer to a question that I am sure you all have: What is the difference between 6CB6 and 6CB6A vacuum tubes? Since I like Tung Sol tubes I ordered a set and received 6CB6 tubes from 1957. After 20 hours burn in they sound delicious.(Hopefully, a comparison of these tubes with the EF92 Mullards will follow).
   
  However, should I have ordered GE 6CB6A tubes instead?
   
  Now, here is the answer about the difference:
   
  "In the early days all TVs and most radios had power transformers. The tube heaters were all wired in parallel and fed 6.3 volts. As with everything, cost reduction eventually chased the power transformer out of TV sets. The tube heaters got wired in series, running directly from the line voltage. Tube heaters have a positive temperature coefficient. Their resistance is low and increases as it warms up. When they are all in series, they better all warm up in the same manner, or the fastest tube will get all of the voltage and light up like a flashbulb. It was decreed that the warm up time will be controlled and specified to be 11 seconds. The conditions for measuring the 11 seconds was specified and each tube got its revision letter upreved when the change was made. This is usually clearly specified in the data sheet.

 The 1961 GE datasheet that is on my hard drive does specify an 11 second warm up time, it is not spelled out like it is in other books.

 I have a 1966 edition of the RCA Receiving Tube Manual that I bought new at Lafayette Radio Electronics in 1966 for $1.25. It still has the LRE sticker on it. Here it states that "types 3CB6, 4CB6, and 6CB6 are identical with type 6CB6A except for heater ratings". In the specs all are listed at 11 seconds except for the 6CB6.

 In my 1963 RCA book it states "Type 6CB6A has a controlled heater warm-up time for use in television receivers employing series-connected heater strings."
   
  The A has a slow warmup feature for the heater so it doesn't blow as quickly. The 'A' types are going to be much more common since so many of these were required by TV set manufacturers. "   So far the quotes.
   
   
  Can anybody tell me if there would be a difference in the sound between 6CB6 and 6CB6A tubes? Are 3CB6 and 4CB6 tubes good alternatives for LD MKIII. Any impressions about sound quality?


----------



## mojorisin35

mikelap said:


> i ordered 2 pairs of Tesla 6f32v tubes on the 19 of february and they left Moscow today the 12 marsh  so i expect to get them in a week or so.




Mike i am very curious as to your take on the tesla's. the ones I have have stab written on the side and also have a white paint on The top of the tube making it look like it is wearing a elf hat. There are other tesla 6f32 tubes with yellow writing and no paint that I understand sound quite different which ones did you order? So far my tesla's are kicking everything else out of the sockets. I just received a pair of tung sol 6ak5 that are pretty awesome we will see after burn in.


----------



## Audiofanboy

Quote: 





mordy said:


> Can anybody tell me if there would be a difference in the sound between 6CB6 and 6CB6A tubes? Are 3CB6 and 4CB6 tubes good alternatives for LD MKIII. Any impressions about sound quality?


 
  I'd expect more of a difference between the 6CB6A and the special quality 6676 than between the 6CB6 and 6CB6A, but there's probably some difference. And the different example I have of the GE 6676 I have both have 6CB6A etched in the glass and never 6CB6, so if anything the controlled heater type can't be worse than its predecessor.
   
  3CB6 and 4CB6, having respectively 3 & 4V filament voltages, would not work in the 6.3V wired LD amps, nor would any other non-6.3V filament tube for that matter; not without a major change on the circuit board at least.


----------



## Audiofanboy

Alright, after 15-16 of burn-in, here are a few more impressions on the GE 8425A/6AU6A.
   
  They are definitely extremely musical and detailed, the best example I've seen so far of "tube realism" (see earlier first impressions for what I mean by that with the "singer in the studio" and all). Paired with the 6N30P-DR, these make my amp into a truly excellent unit, surprisingly so. They are just liquid enough  to always be pleasant and toe-tapping while remaining perfectly neutral and controlled at all times over the whole frequency range. Best imaging and natural 3D feeling I've heard (3D as in how/where the song was recorded and no more no less, not fake head-in-a-cave kind of 3D or even head-in-a-bubble -pleasant in its own right- kind of 3D that I was often getting with last week's tubes).
   
  Gain is on par with 6CB6 tubes or most non-EF91 300mA heater current tubes, with less gain than a CV4014. The tubes improved a fair amount with burn-in, everything just kind of fell into place, the chewy textured not-too-tubey-and-just-liquid-enough mids, the mellow detailed non-annoying very natural highs and the bass also improved noticeably (both in amount -slightly- and in quality and control), it is now nice and tight and precise, and reminds me a bit of the CV4015 bass with a bit more power and the same kind of articulation. These tubes have very good transient response and great decay, not ultra-fast like some good SS but natural and realistic and just normal fast. Near perfect separation and staging too (you wouldn't believe how real the singer's voice sounds with these on good records).
   
  Overall, these might be the best driver tubes I've tried on my amp, *A+* grade without a doubt and bordering on A++ (which would make every other tube go down one grade), actually I'm giving these a tentative *A+(+)* until I finish testing the other tubes I'm expecting. These are my new "best tubes" and favorites I guess, they do everything I loved about the CV4015 -that weren't powerful enough anymore for me- the naturalness mainly, and take it a whole other level and add extra power in the mix.
   
  So, to update my "top tier" tube list or my three favorites I warmly recommend, I would suggest the above as N°1, the GEC CV4014 as N°2 (still a solid A+ tube as well with more gain, more liquidity, more impact and punch, but less neutral and natural and differently detailed and staged and maybe ever so slightly below the 8425A in those areas) and the Mullard CV4015 as N°3 (though not for orthos as they have much less gain, but their soundstage is on par with other two, and they are as realistic, natural and neutral as the 8425A, but less punchy than the CV4014 and have less authority than the two other tubes).
   
  The list and "grading system" might evolve again very quickly as when I tested the other matched pair of GE JAN 6AU6WC before leaving it to burn-in for the work day, they sounded as good if not perhaps better than the 8425A unburnt-in... Then again, the 6AU6WC have the special quality 6136 etched in the glass, whereas the 8425A "only" had 6AU6A etched. Expect the answer this weekend!


----------



## mordy

Thanks for your reply - looking forward to hear more about the great tubes for the LD that you are discovering!


----------



## MIKELAP

Quote: 





mojorisin35 said:


> Mike i am very curious as to your take on the tesla's. the ones I have have stab written on the side and also have a white paint on The top of the tube making it look like it is wearing a elf hat. There are other tesla 6f32 tubes with yellow writing and no paint that I understand sound quite different which ones did you order? So far my tesla's are kicking everything else out of the sockets. I just received a pair of tung sol 6ak5 that are pretty awesome we will see after burn in.


 
  heres the picture and data from store i got them from but havent got them yet .


----------



## mordy

About changing tubes from different families: There are available vacuum tube socket adapters that allow tubes with different amount of pins or pin patterns to be plugged directly into the tube socket.Below is an EBay link. Is there anything there that is suitable for use with LD amps?
   
   
   
  http://www.ebay.com/sch/i.html?_odkw=6676+vacuum+tube&_osacat=0&_from=R40&_trksid=p2045573.m570.l1313&_nkw=vacuum+tube+socket+adapter&_sacat=0


----------



## gibosi

Quote: 





audiofanboy said:


> So, to update my "top tier" tube list or my three favorites I warmly recommend, I would suggest the above as N°1, the GEC CV4014 as N°2 (still a solid A+ tube as well with more gain, more liquidity, more impact and punch, but less neutral and natural and differently detailed and staged and maybe ever so slightly below the 8425A in those areas) and the Mullard CV4015 as N°3


 
  How about the 6EW6?


----------



## Audiofanboy

Quote: 





gibosi said:


> How about the 6EW6?


 

 I think I gave my GE 6EW6 a solid A grade, which would place them at N°6 or 7 or something on my list (the 6GM6 would be N°4 or 5 but microphonic as they are they won't be used), the 8136, 6CB6A and 6GY6 would be at N°7 or 8 I guess, and a bunch of the best 6AK5 tubes and some other brand CV4014 would be somewhere before or at N°10. So something like:
   
  1 - GE 8425A/6AU6A
  2 - GEC CV4014
  3 - Mullard CV4015
  4 - GE 6GM6, 6EW6, 6GX6/6GY6
  5 - GE 8136, 6CB6A, Mullard CV4014/M8083 (Mitcham), Tung Sol 6AJ5, Mullard CV4010/M8100, Voskhod 6J1P-EV (Gold grids), Mullard CV5377 (Mitcham), Mullard CV4014 (Whyteleafe)
  6 - Brimar CV4014, Mullard CV138/6AM6, Voskhod 6J1P-EV (Non-gold grids), Brimar CV138, Mullard CV850 (Whyteleafe), Tung Sol 6AK5 (side getter, early shape, 1943), GE JAN 5654W


----------



## gibosi

A pair of GE 8425A/6AU6As recently arrived and are now burning in. Interestingly, they appear to be identical to my standard GEs (8425A on the left and standard on the right). I wonder what the difference is? Perhaps the 8425As are simply standard tubes that have been tested and graded to be among the best? Anyway, after burn in, I wonder if I will be able to discern any difference.
   
  I should note that my standard GEs are very quiet with no microphonics. They are currently my NO.1.
   
  (Oh, these tubes are laying on their sides on a glass table top so the coin to the right is there to keep them from rolling. I wanted to photograph both of them together from the same angle.)


----------



## Audiofanboy

Quote: 





mordy said:


> About changing tubes from different families: There are available vacuum tube socket adapters that allow tubes with different amount of pins or pin patterns to be plugged directly into the tube socket.Below is an EBay link. Is there anything there that is suitable for use with LD amps?
> 
> 
> 
> http://www.ebay.com/sch/i.html?_odkw=6676+vacuum+tube&_osacat=0&_from=R40&_trksid=p2045573.m570.l1313&_nkw=vacuum+tube+socket+adapter&_sacat=0


 

 Interestingly, there aren't that many 7 pin (7BK generic base) adapters than can be used in LD amps. They exist and are quite expensive for what they do but considering the amount of 7BK base tubes that exist, and that few people have even tested the "modded" 6AU6 types yet, I'd say were still a long way from testing 8 and 9 pin tube for compatibility; and 7 pin to 7 pin adapters just to link two socket holes seems like kind of a waste. This being said, I know some octal base tubes could work in the amp as they have very similar characteristics but I haven't seen any logically compatible 9 pin tubes (often double triodes or triode-pentodes but not so much single pentode or beam tetrodes like we've been using). I've a number of 7 pin triodes, with more or less close pin layout; for these an adapter could be useful I guess, if there's more than two socket hole to bridge or cut. Then again, one could imagine a even larger adapter that would cover both tube sockets to use a double triode, like the 6922, instead of two triode-strapped pentodes. There's still a bit left to investigate I guess...


----------



## Acapella11

Quote: 





gibosi said:


> *How about the 6EW6?*


 
   
  Brief update after more listening and comparing* 6EW6  to CV4015*:
   
  Accuracy, transparency and neutrality: CV4015 > 6EW6.
  Treble: CV4015 > 6EW6
  Mids: CV4015 = 6EW6 just different with 6EW6 more seducing and CV4015 more clean
  Bass: 6EW6 = CV4015, the bass is different though, CV4015 is better articulated, defined but  the 6EW6 goes deeper, there is more a deep bass vibe to them. In summary, I would say they come out similar.
  Noise background: CV4015 better than 6EW6. CV is military grade after all. 6EW6 background improves over the burn in process to a decent level.
   
 Overall, the CV4015 are more audiophile, I would say, also more treble oriented and clean. The 6EW6, more on the warm, seducing side and with more bass extension. CV4015 comes out better after all but they do not compete within the same signature. 6EW6 is like a higher gain "honey coated" CV4015, if that makes sense . Although the CV4015 in summary wins the competition, you would want Norah Jones rather whisper through the 6EW6 into your ears...
  
   
  Quote: 





audiofanboy said:


> I can only speak for the -DRs but they definitely have *much better upper end extension, and a much more linear and extended lower end* - they are in essence very linear imo, it's the driver tubes that end up "biasing" them to a more or less U or V shaped signature. Basically, I'd say the *R -low-noise- trait does exactly what it's supposed to, the lower noise level allows for much more clarity and transparency, and for micro-details* (airiness and instrument separation in the highs), texture of sounds and realism of transients (mids and bass) to be that much better than their non-R counterparts. Of course, that low noise effect is more apparent the more transparent you gear is up to the power tubes, including driver tubes, but not only (software, transport, DAC).


 
   
*Power tube R suffix*
   
  This makes sense and I have observed the same with the two points you mentioned.
   
  - *Bass and treble* are more extended with the 6N6P-IR compared to 6N6P-I.
  - The IR's* background* is pitch black, so yes, micro details are better.
  - However, the first thing you notice when listening to the 6N6P-IR is the *larger stage*, the overall greater spatial arrangement. This is - *the* - first big difference and immediate impression I had.
   
  
 Guys, enjoy to see how deep the LD tube rabbit hole is...
  
  
 Edit: Just on a side note: I am not sure how much of deal a *gold grid* really is. For example, I have two Voskhods, with and without gold grid - they almost sound identical. However, a third pair from 1975 is a bit better. It has more bass impact compared to either of the other two, but sounds otherwise very similar. I also heard that the 6N6P rather scale with the year of production. So, a 1970 should be way better than a 1990. Maybe gold adds some shine on it but I think year of production seems to have more impact.


----------



## Audiofanboy

Quote: 





acapella11 said:


> Brief update after more listening and comparing* 6EW6  to CV4015*:
> 
> Accuracy, transparency and neutrality: CV4015 > 6EW6.
> Treble: CV4015 > 6EW6
> ... 
  I pretty much agree with what you say about the 6EW6 and the comparison with the similar sounding CV4015. A higher gain, nearly as good but with a more in your head soundstage, more punchy bass-ed CV4015. The higher gain and stronger -trade-off for articulation- bass compensate for most faults this tube has compared to the CV4015 and make it an excellent versatile tube imo. It works very well with electronic music btw. While not as black background-ed as my absolutely quiet CV4015, my military non-mil spec 6EW6 are quiet after 10h+ of burn-in, enough not to have to worry about it.
   
  About the -R suffix-ed Russians tubes, where you notice a larger stage (I assume "wider") with the 6N6P-IR, I noticed a "deeper" and "higher" soundstage (I had the "wide" trait covered), so basically a true 3D stage compared to an excellent 2D or pseudo-3D stage I had before. Again, I assume the low noise -R suffix to play a big part in that better and more precise soundstage pattern, both in 6N6P and 6N30P types. I think "gold grids" or gold and platinum grids just kind of come with the best mil spec Russian tubes made in the best times with the best quality control, and are not, in and of themselves, a guarantee of sound quality. I keep reading about how good some 6N6P made in the 60s are supposed to sound and these never have the gold grids trait mentioned; it's the tubes from the 80s and maybe late 70s that have it. The -R suffix-ed tubes seem to naturally have those too. I know my Voskhods 6J1P-EV made 15 years apart and with and without gold grids sound quite different, especially after the loooong burn-in -one improved and the other plunged.
   
  While I'm at it, here's my review/feedback of my *GE JAN 6AU6WC*, etched 6136, made in 1978, which might have been a bit late. After 15 hours of burn-in, these sound very similar to my GE 8425A, with a bit more bass -not better- and maybe a tiny bit more micro-detail and a tad less gain. BUT, they make music sound like it comes from behind a thin veil, curtain or foam (like foam used to roll-off spiky treble). It reminds me of that muting pedal on pianos that make piano notes sound muffled -keeping their harmonics and detail but muted or sounded a bit "choked" but not muddy either. In this case, you can still hear all the details, but they just don't leap out at you like the 8425A -or CV4015 and GEC CV4014 for that matter- you have to focus to actually hear everything, but it's all there. Overall, a solid *A grade* tube, that would work well with "Norah Jones" singer/songwriter type music, where intimacy and smoky curtains are preferred to ultra-detailed and analytical tubes -which the 8425A is not as it is just natural. Again, the details are all there, but you have to relax to hear them which I don't always have time to do/feel like doing. Last thing, bass is more muddy than the 8425A, fuller too but not articulate, and that takes the "+" off that A in my book.
   
  Listening to the 8425As again, these are definitely less muffled, more natural, musical and fun (not V-shaped sound fun, just... well, fun). Stuff just falls into place with these, and the bass goes looow -and is articulate- which hadn't struck me the first time around. Definitely my new A+(+) tube. Acapella, if your reference is the CV4015, you would love these!
   
  I'm starting to wonder if GE still had their Schiit together making tubes starting in the mid-70s and worse in the 80s. I had bought some GE JAN 5654W half a year ago, made in 1985 by GE for the military and they really weren't that good; I mean you could tell the quality control had gone down the drain. The construction was nothing like what I read about, not clean or best in class but kind of lackluster (the innards weren't straight and the tube base was all weird looking, even the silk writing was a little off), the tubes crackled and popped when I first tested them, and it got better and quiet after a few minutes -a far cry from what I've been used to with mil-spec tubes, including GEs- and after 25h of burn-in they just didn't make the cut; they weren't unpleasant but just not as detailed or fun or well soundstaged like my other basic 6AK5 tubes in those days. I wonder if my -still excellent- GE JAN 6AU6WC from 1978 aren't a bit like that. They look great (although the getter flash made from their halo getter doesn't actually cover the top part of the tube, but made a donut shaped flash that makes my tubes look like bald monks, I can see the filament light from a small hole above the tube; looks amusing but first signs of QC issues?), sound nice but just aren't as good as the 8425A/6AU6A from the same brand -non JAN- made in 1964, like the QC process gradually went downhill as demand for tubes did -apart from the government that bought lifetime stocks of whichever tubes they still needed, tubes that are now massively on fleebay  .
   
  Oh the rabbit hole is deeeeep, and getting deeper by the second! "_Off with their tubes_" said the Queen... Even though I'm not done testing the 6AU6 family, I'm already on an other tube type, and I have two or three more lined up for investigation. There is no end to this, and the 8425A/6AU6A are already forcing me to revise my grading scale... _Who's next?_


----------



## Acapella11

Quote:  





> About the -R suffix-ed Russians tubes, where you notice *a larger stage (I assume "wider") with the 6N6P-IR, I noticed a "deeper" and "higher" soundstage* (I had the "wide" trait covered), so basically a true 3D stage compared to an excellent 2D or pseudo-3D stage I had before. Again, I assume the low noise -R suffix to play a big part in that better and more precise soundstage pattern, both in 6N6P and 6N30P types. I think "gold grids" or gold and platinum grids just kind of come with the best mil spec Russian tubes made in the best times with the best quality control, and are not, in and of themselves, a guarantee of sound quality. I keep reading about how good some 6N6P made in the 60s are supposed to sound and these never have the gold grids trait mentioned; it's the tubes from the 80s and maybe late 70s that have it. The -R suffix-ed tubes seem to naturally have those too. I know my Voskhods 6J1P-EV made 15 years apart and with and without gold grids sound quite different, especially after the loooong burn-in -one improved and the other plunged.


 
   
  Just for your information: wider and mainly deeper, actually. The overall representation reflects more a hall if that is what it was during the recording. So, more agreement here.
   
  Yes, the years of production really seem to be a key point of tube sound quality (old wisdom here I guess, just putting it together with gold grids). Unfortunately, the labels on my gold-grid Voskhods are washed out in a way that I cannot read a year.
   
  Have fun mate.


----------



## mab1376

So turn out when my amp freaked due to a bad jumper it killed one of my GEC CV4014 tubes, now that i got the jumpers replaced one of them has no volume but if I tap the tube itself it generates this high pitched ring that grows louder and louder. Got worried that I broke the amp but once i popped in my M8161 tubes it was happy again.


----------



## gibosi

Quote: 





mab1376 said:


> So turn out when my amp freaked due to a bad jumper it killed one of my GEC CV4014 tubes, now that i got the jumpers replaced one of them has no volume but if I tap the tube itself it generates this high pitched ring that grows louder and louder. Got worried that I broke the amp but once i popped in my M8161 tubes it was happy again.


 
   
  That's really crummy... But for sure, it's good that it was only a tube, and not your amp! And now you have an excellent excuse to try a nice GE [size=small]8425A/6AU6A! [/size]


----------



## mordy

Dear Gibosi,
   
  Top News!  Gold discovered in US tubes!
   
  Came across a fascinating document about the GE 5 Star tube program. From a cursory reading these tubes were developed to be the ultimate in reliability for the airline industry, and yes, they feature gold (or silver) grids! (page 16) Here is the reference from the early 50's:
   
  http://www.tubebooks.org/tubedata/GE_5star.pdf
   
  BTW, this document shows you all the tube parts with excellent pictures and explanations.
   
  So now my question:
  I am looking to buy the GE 6AU6 tubes that are top rated on this forum. Do you think that the military version GE 6AU6WA is a better choice? In addition, there are GE 5 Star 6AU6WA tubes available as well. Would they be even better sound wise?


----------



## gibosi

Quote: 





mordy said:


> Came across a fascinating document about the GE 5 Star tube program.
> 
> So now my question:
> I am looking to buy the GE 6AU6 tubes that are top rated on this forum. Do you think that the military version GE 6AU6WA is a better choice? In addition, there are GE 5 Star 6AU6WA tubes available as well. Would they be even better sound wise?


 
   
  What a great document! Thanks for sharing! 
   
  Your questions are great questions. However, this forum's collective experience with 6AU6s is still tiny. To my knowledge, only Audiofanboy and myself have installed 6AU6s in our LDs.
   
  (If there are others out who have, please tell us!)
   
  Based on the experience of only two persons, the GE 8425A/6AU6As are highly recommended. Audiofanboy did report about his experience with a pair of 1978 GE JAN 6AU6WC and he did not recommend them over the 8425As.
   
  All I have at present is a pair of 8425As. I do have a a pair of 1960s GE JAN 6AU6 WB / 6136 on the way, but won't get them until some time next week. I also have a pair of RCA Command 6136s, 1950s mil-spec Tung-Sols, and of course Russian 6J4Ps on the way. 
   
  I think it is worth pointing out that just because a particular pentode is considered one of the very best for RF purposes, we cannot then conclude that this same pentode will excel when converted into a triode for audio purposes. After all, the GE 5 Star 6AK5s are generally not ranked as one of the very best 6AK5s...
   
  So my recommendation is that you purchase one pair of each! 8425A,  GE 5 Star, and standard mil-spec! And then tell us what you think! LOL. (And if you actually do decide to do this, I would recommend nothing later than the 1960s.)
   
  But if you want to buy only one pair, the 8425As are a very safe bet.


----------



## mab1376

I just ordered some 1960's GE 6AU6A tubes, do I need to jump with pins on the socket in order to use them? And should the the 6AK5 setting, correct?


----------



## Audiofanboy

Quote: 





mab1376 said:


> I just ordered some 1960's GE 6AU6A tubes, do I need to jump with pins on the socket in order to use them? And should the the 6AK5 setting, correct?


 

 Yup, you can just bridge socket pins 2 and 7 like on the picture I posted two pages back. And yes, 6AK5 jumper setting or explosion. I am sorry for your GEC CV4014 and your near-deaf-experience, but I 'd recommend trying them again, as I haven't found another awesome tube like that one with as much gain (CV4014 has a gain of 75, whereas 6AU6A has a gain of 36), so it's still a very useful tube to have on hand if just for that reason.


----------



## mab1376

Quote: 





audiofanboy said:


> Yup, you can just bridge socket pins 2 and 7 like on the picture I posted two pages back. And yes, 6AK5 jumper setting or explosion. I am sorry for your GEC CV4014 and your near-deaf-experience, but I 'd recommend trying them again, as I haven't found another awesome tube like that one with as much gain (CV4014 has a gain of 75, whereas 6AU6A has a gain of 36), so it's still a very useful tube to have on hand if just for that reason.


 
   
  I emailed the eBay seller and asked if I can get a replacement, worst case I'll just pickup another. any sellers you recommend?


----------



## Audiofanboy

Quote: 





mab1376 said:


> I emailed the eBay seller and asked if I can get a replacement, worst case I'll just pickup another. any sellers you recommend?


 

 As far as permanent buy-it-now auctions go, I've only seen the two sellers that are in the UK -and quite expensive if I may say so myself.


----------



## mordy

Hi All,
   
  Found some comments on the military spec tubes re the 6AU6WA and now 6AU6WC tubes. Does ruggedness in construction affect the sound?:
   





  "W is ruggedized. C is "improved ratings/performance". That doesn't necessarily mean they will sound better. Tubes manufactured for portable military applications may not produce better audio quality. They were much more concerned with reliability then sound quality. Then again, maybe better mechanical design will also produce better sound. Only one way to find out.
  
  If it's ruggedized it might not sound better, but it'll sound the way it does a lot longer than a standard version. "
   
  I think that this pretty much sums it up.
   
  Re the GE Five Star tubes I have a couple of the 6AK5 variants and I was not so impressed by the sound. In addition, I also had a pair of 6AK5 1980's tubes that sounded quite poor. It looks like the golden age of tubes was in 50's to 70's, and for Russian tubes up to the fall of Communism; the consensus seems to be that Russki 70's - to early 80's tubes are the best.
   
  Re the gold grids in Russian tubes: The Voskhods I have from the 70's sound different with the gold grid ones sounding more mellow. (And yes, both pairs went through a grueling 120 hour break in). Likewise, the 6N6P with gold grids sound nicer than the regular ones, and these are the power tubes I use. Good to know that the Russians copied us on the gold grid...


----------



## mab1376

audiofanboy said:


> As far as permanent buy-it-now auctions go, I've only seen the two sellers that are in the UK -and quite expensive if I may say so myself.




Lucky for me the seller already responded and is going to send me another free of charge.


----------



## gibosi

A pair of 1964 RCA Command 6AU6/6136 arrived today and are now burning in. It is my understanding that these are the best consumer tubes that RCA made, comparable to Sylvania's Gold Brand I assume (but no gold pins). First impressions (but remember I have rusty ears and cheap gear!), these sound very good. 
   
  I will report back later....


----------



## gibosi

After 10+ hours, the sound of these 1964 RCA Command 6136s is indistinguishable from my GE 8425As (according to my rusty ears with cheap gear . All the many good words written about the 8425As apply to these RCAs. They are very quiet, very musical and very enjoyable. And it seems that RCA's best consumer-grade tubes hold their own with the best of them. They will stay in my LD as my primary tubes until... the next new tube shows up my mailbox.


----------



## Audiofanboy

Quote: 





gibosi said:


> After 10+ hours, the sound of these 1964 RCA Command 6136s is indistinguishable from my GE 8425As (according to my rusty ears with cheap gear . All the many good words written about the 8425As apply to these RCAs. They are very quiet, very musical and very enjoyable. And it seems that RCA's best consumer-grade tubes hold their own with the best of them. They will stay in my LD as my primary tubes until... the next new tube shows up my mailbox.


 

 Interesting, I would have expected some house sound differences at least, like warmer or darker or more bassy, but alright. Did you ever feel a difference between the GE 6AU6A and the 8425A btw?


----------



## gibosi

No, I wasn't able to discern any difference between the GE 6AU6A and the 8425A either. That said, I can easily hear differences between the various 6AK5s. And recently, it was easy for me to detect differences between major tube families, for example, 6CB6, 6WE6, 6GX6, 6GM6, 8136 and most recently, 6AU6. So I have to assume that any differences that might exist between these 6AU6s must be fairly subtle, requiring better ears and better gear than I have.....  and more experience...
   
  The LD1+ is my very first headphone amp and I have had it for only three months. I bought my first full-sized budget headphones shortly thereafter. Before that, I listened to Pandora on a cell phone with IEMs... 
   
  I try to contribute what I can, but I am truly a freshman in the company of graduate students.


----------



## Audiofanboy

Quote: 





gibosi said:


> No, I wasn't able to discern any difference between the GE 6AU6A and the 8425A either. That said, I can easily hear differences between the various 6AK5s. And recently, it was easy for me to detect differences between major tube families, for example, 6CB6, 6WE6, 6GX6, 6GM6, 8136 and most recently, 6AU6. So I have to assume that any differences that might exist between these 6AU6s must be fairly subtle, requiring better ears and better gear than I have.....  and more experience...
> 
> The LD1+ is my very first headphone amp and I have had it for only three months. I bought my first full-sized budget headphones shortly thereafter. Before that, I listened to Pandora on a cell phone with IEMs...
> 
> I try to contribute what I can, but I am truly a freshman in the company of graduate students.


 
  Well, I guess not all tube families show as much variety as the 6AK5 or EF91 families, or even all the different types we've been testing on lately.
   
  In the meantime, I had ordered and just got in the mail 3 pairs of 6AH6 tubes. Not a single plain Jane one (for $2/3 a tube who cares?), and not just GE for once:
  - JAN Raytheon 6AH6WA - 1973
  - JAN Sylvania 6AH6WA - 1970
  - JAN GE 6485 - 1978 (that was before my conclusion about 70/80s GEs, oh well, we'll see if these are good or not...)
   
  The 6AH6WA and 6485 are, as usual, the special quality versions of the 6AH6, which is considered and even recommended as a replacement of the 6AU6 in many circuits. So if the 6AU6 works so well in the LD amps, why wouldn't these be as good or better? Note that the 6AH6 has similar recommended plate voltage and cathode resistance triode-strapped compared to a 6AK5 -just like the 6AU6- which means the amp should be very well suited and biased for this type, unlike many types I tried in the last two weeks, that had different cathode resistance recommendations and other recommend settings (could explains why some tubes didn't fare so well).
   
  I put the Raytheons for burn-in this morning and first impressions are very favorable; I'll wait the usual 10h to give more details.
   
  The 6AH6 are sharp-cutoff pentodes with a 450 mA filament current (6AU6 has a 300 mA heater). These should have almost the same voltage gain/amplification factor/mu (40 instead of 36) as the 6AU6, so I didn't expect much more volume and didn't find a significant difference in level compared to the 6AU6; and they have more than double the transconductance/gm (11000 mmhos instead of ~5000) the 6AU6 has, which I'm still struggling to find out what effect that would have on the sound, should mean more mA on the anode -and into the power tubes- for every V on the control grid, so higher output current and lower output impedance if I understand... Apart from that, these tubes have similar characteristics and are known to work well in audio circuits triode-strapped (the datasheets even have triode curves for both), so it should interesting to see how they fare compared to the 6AU6.
   
  I also ordered and got a -final- 6AG5 tube with the 3 pairs of 6AH6, last try for this tube family. A Sylvania JAN 6AG5WA/6186 dated 1967, how bad can it be really, it's mil spec, special type and from the 60s (so final improved construction and getter structure). Just so I can reach some kind of closure on the 6AG5 family after the disappointment the Russian 6J3P-E were (not 6AG5 really, but the point remains)...
   
  I'll try to put some pics up at some point when I start reviewing these tubes.


----------



## gibosi

And I have a pair of 1961 Tung-Sol JAN 6AH6s burning in:
   
   

   
  Interestingly, these have a very open cage assembly compared to the 6AU6s, and in a dark room, they light up very nicely. First impressions, they look good and sound good.


----------



## MIKELAP

Quote: 





gibosi said:


> And I have a pair of 1961 Tung-Sol JAN 6AH6s burning in:
> 
> 
> 
> ...


 
  So sexy ouah !


----------



## Audiofanboy

A few pics of the 6AH6 tubes as promised. First, the *Raytheon JAN 6AH6WA* packed and made in 1973, which I now know is probably later than I should have bought. These are very well built and look great up close.
   

   
  And while I am it, here's a bit of a review of these after a day. They are balanced and detailed with a nice deep soundstage and slightly loose and grainy bass that goes pretty low, but are ultimately too veiled and not transparent enough after 10h of burn-in to warrant more listening. They aren't unpleasant and are quite tame in the highs -for those of you that like rolled-off treble- but they just don't make the cut compared to the kind of sound I've been hearing for the last couple of weeks. A *B+* grade tube, which is actually pretty good for $3 NIB tubes with mil specs. Btw, for a 450 mA heater current, these really let the amp run pretty cool, a far cry from the EF91. Apparently, the gain of driver tubes (and the relative volume they produce) seem to be more correlated to amplifier heat dissipation than any other tube spec; which makes sense, more voltage going through everything, more loss do to heat.
   
  Second, some *Sylvania JAN 6AH6WA* packed in 1970 and possibly made that year or the year before -getting closer to the 60s which is good for US tubes. These are extremely well built -best of the 3 6AH6 tubes I got- and the inner construction reeks of quality; I noted and you can see on the pic that the grids inside seem to be "gold colored", not necessarily gold but not that basic steel-grey color like on the Raytheons and others. At any rate, these were left to burn-in for the day and this time, first impressions are excellent, I can't imagine this tube getting less than an A grade really; highs are very detailed out of the box and have a really nice flavor to them, more later.
   

   
  Third and last, *GE JAN 6485* packed and made in 1978. I probably should not have bought those... Made too late in time, basic "6AH6" etched in glass, poor construction -tubes aren't perfectly straight just like cheap late 6AK5- and innards are lackluster -the anode on 6AH6 tubes is two separate pieces like on most recently tested tubes, the Raytheons and Sylvanias have both anode parts made and attached from a single sheet, the GE does not, it's just two anodes linked by a silly copper wire, disappointing, 70s/80s GE = poor quality- and the tubes just don't have that "shine" about them that the best JAN tubes have. Anyway, I'll try them as they're still special quality tubes, but I'm not hoping for much...
   

   
  And bonus tubes, just for kicks, some *Sylvania JAN 6AG5WA 6186* made and packed in 1967. These actually look great too, making me think I should buy more Sylvanias and less GE. Very nice construction with nice insides, these actually have both 6186 -special quality- and 6AG5WA etched on the glass, so I can't really imagine what I could have picked better in the 6AG5 family really. If these don't sound OK, then I'm done with that tube type anyway...


----------



## gibosi

A pair of GE 6485/6AH6s arrived in this mornings' mail.
   

   
  I believe these are 1960's vintage, but am not positive. I cannot find anything on the web about this "NV" code. However my GE 8524A/6AU6s had a "NW" code plus the date 67-32, so I am guessing these are 1960's vintage as well....  Also of interest, the cage structure on these is quite different than the Tung Sols I received yesterday. I hope to get to these over the weekend.
   
  And I am currently listening to a pair of 6HS6s.
   

   
  These are purported to be a souped up 450 mA version of the 6AU6 (9500 gm and 50 mu), but unfortunately, they are rare and expensive. The cheapest price I am seeing on eBay for a pair is in excess of $80.00! Mine are used, as I pulled them out of some old McIntosh equipment. The tubes are dated 1970. As you can see, all the printing has worn off, but the shape of the shield suggests that they might be RCAs. Most unfortunately, one of these tubes has a significant ground hum...  I am currently cooking them in the LD with the hope that the hum will dissipate. However, as these are not NOS, but used, I have no idea if they might improve. Nonetheless, these sound very good to my amateur ears. If you can find a pair cheap, I believe these are well worth checking out.


----------



## Audiofanboy

Quote: 





gibosi said:


> A pair of GE 6485/6AH6s arrived in this mornings' mail.
> 
> 
> 
> ...


 

 Nice tubes! I'm really curious about how the 6HS6 will sound if they (it) stops humming. One question though, what do the anodes look like on your GE 6485? Do they look like two plates, one on each side, just linked by a copper wire on one side, or linked by two solid metal bands? I think I see a cheap looking wire soldered on one of the anodes on the right tubes just like on mine, but I'm not quite sure...


----------



## gibosi

Quote: 





audiofanboy said:


> One question though, what do the anodes look like on your GE 6485? Do they look like two plates, one on each side, just linked by a copper wire on one side, or linked by two solid metal bands? I think I see a cheap looking wire soldered on one of the anodes on the right tubes just like on mine, but I'm not quite sure...


 
   
  Yeah, you are right! Just a cheap looking copper wire! So much for the 6485s being "premium" tubes! LOL


----------



## gibosi

Quote: 





audiofanboy said:


> Nice tubes! I'm really curious about how the 6HS6 will sound if they (it) stops humming.


 
   
  Unfortunately, even after some 15 hours of cooking, the ground hum is still there...  Nonetheless, these are very good sounding tubes. As one might expect they sound like the 6AU6. I really cannot hear any difference between these and my 8425As,.. Except for the ground hum!
   
  It occurs to me that perhaps if I had some carefully selected tracks chosen to reveal subtle audio differences, perhaps one track for sub bass, one for highs, one for sound stage and imaging, and so forth, this might help me distinguish between tubes that are both very good and very similar.
   
  Any suggestions or advice? Anyone? When introducing a new tube, headphones, or other piece of equipment into your system, what routines or methodologies do you use to help you to hear and understand the differences?


----------



## MIKELAP

Finally received today my TESLA 6F32V after a months wait (mother russia is far away)  right off the bat i like them i like the bassy sound and a decent soundstage top end just perfect for me so that probably means cleaner sounding  for younger ears but sounds good .I  i like them more than the 6aj5 and the 6ak5w/6096 right out of the box thats paired with 6h30pi gold pins power tubes


----------



## gibosi

Quote: 





mikelap said:


> Finally received today my TESLA 6F32V after a months wait (mother russia is far away)  right off the bat i like them i like the bassy sound and a decent soundstage top end just perfect for me so that probably means cleaner sounding  for younger ears but sounds good .I  i like them more than the 6aj5 and the 6ak5w/6096 right out of the box thats paired with 6h30pi gold pins power tubes


 
   
  Glad to hear that they are everything you hoped for, especially given how long you had to wait! I notice that yours look somewhat different than the ones that mojorisin35 and I have. The build quality of yours clearly looks quite a bit better.... I wonder how they compare in sound?
   
   

   
  Unfortunately, one of mine is very microphonic to the point that it is not usable. That said, I felt that these sounded very similar to the Russian Voshkods. And given the fact that the Tesla facilities were located in Czechoslovakia, I wonder if there might have been a degree of technology transfer between Tesla and the Russians...


----------



## MIKELAP

Quote: 





gibosi said:


> Glad to hear that they are everything you hoped for, especially given how long you had to wait! I notice that yours look somewhat different than the ones that mojorisin35 and I have. The build quality of yours clearly looks quite a bit better.... I wonder how they compare in sound?
> 
> 
> 
> ...


 
  ive been playing them for a couple of hours and the bass kind of mellowed out a bit but they are  cleaner sounding now you talked about the voshkod well its true they sound similar but upper end of the Tesla not harsh yet anyways i dont really like the vohkods that much the highs are a bit harsh if i remember correctly does that make any sense . And i want to add that they look like they where made yesterday dont know when they were made dough.


----------



## Seadubb

I recently sold my LD MKiii, so I have a few sets of tubes with low hours on them. Sylvania, Voskhod, Tung Sol, and Electro Harmanix power tubes. PM me if you want more details.


----------



## gibosi

Six 6J4Ps (Russian equivalent of the 6AU6/EF94) arrived in today's mail:
   

   
  These are rather nice looking tubes, manufactured in in November, 1975. However, all six are pretty noisy so I can't say how they sound. Two of them are burning in at the present time, and I really hope they will quiet down.


----------



## MIKELAP

Quote: 





mikelap said:


> Finally received today my TESLA 6F32V after a months wait (mother russia is far away)  right off the bat i like them i like the bassy sound and a decent soundstage top end just perfect for me so that probably means cleaner sounding  for younger ears but sounds good .I  i like them more than the 6aj5 and the 6ak5w/6096 right out of the box thats paired with 6h30pi gold pins power tubes


 
  Well first pair ran for about 8 hours they opened up beautifully  balanced sound burning in 2nd pair of the bat they are  like the other ones at first bassy closed in a bit. tried to find what year they were made in data sheet from tesla says the 60's if you guys have any infos about year of manufacture i would appreciated it. Thanks.


----------



## gibosi

And these pretty little things came the other day, a pair of Philips MiniWatt 408As:
   

   
  However, I believe that the only Little Dot that can use these is the 1+. As I understand, 408As are simply 6AK5s with 20V heaters. Lots of gold and silver in these. And I keep thinking that these just might make some mighty nice earrings, don't you agree? LOL
   
  I need to open up the amp to change a set of jumpers before I can check them out, but with all the other interesting tubes I've been getting recently, just haven't gotten around to it yet...


----------



## gibosi

Quote: 





gibosi said:


> Six 6J4Ps (Russian equivalent of the 6AU6/EF94) arrived in today's mail:
> 
> 
> 
> These are rather nice looking tubes, manufactured in in November, 1975. However, all six are pretty noisy so I can't say how they sound. Two of them are burning in at the present time, and I really hope they will quiet down.


 
   
  After 10 hours of burn, these tubes haven't improved. Moreover, considering that all six were noisy to begin with, I have decided that they aren't worth any more of my time, at least for now. And I would suggest that if anyone else is thinking about these tubes, my experience might be instructive. I should note that the vendor clearly states that these tubes are NOS but not tested. That said, I wonder if the standard "tube testers" most vendors use would even detect this noise?
   
  Oh, on the chance any of you noticed, these tubes really are taller than the the standard American made 6AU6s. I am disappointed... but all six cost me $10, so it doesn't hurt too bad. LOL. Anyway, I still have a few more interesting tubes on the way, so for now, will now go back to my trusted 8425As and enjoy some good music. 
   
  PS: Has anyone else noticed that if you click on pictures included in quotes, you get a little + and if you then click on that, you get a zoomed in view?


----------



## mordy

Hi Mikelap,
   
  Here is a code chart for Tesla tubes in the Czechoslovakian language.  
  From Google translate: 
  MARKING DEVICES TESLA - CODE PRODUCTION DATA. TABLE OF DATA FROM 1947 TO THE END OF 1984
 Sort by year and month of manufacture ascending page 1
   
 code code Month Year Month Year Month Year code code code Month Year Month Year
   
  Here is the link to the code chart - hope it helps.
   
  http://web.archive.org/web/20070824161210/http://www.radiojournal.cz/tab4.htm


----------



## gibosi

Quote: 





mordy said:


> Hi Mikelap,
> 
> Here is a code chart for Tesla tubes in the Czechoslovakian language.
> From Google translate:
> ...


 
   
  This is great! What a sleuth you are!   
   
  So it seems my tubes, TG = Oct 1957. And Mikelap's tubes, AN = May 1963. Only 6 years difference, but in that time they radically changed the internal construction.


----------



## mordy

Hi Gibosi,
   
  Glad to be of help - lucked out and found it quickly.
   
  I have been trying to find out the date codes for Tung Sol tubes. For some reason it is a very difficult task. If it says 3226409 - 3 it is easier; the date is the 9th week in 1964. (This date is a shipping date.) The 3 may be a factory code - there were several factories around Newark, NJ and in Pennsylvania. The 322 is the EIA factory code that were assigned to all US manufacturers; GE is 188, Sylvania 312, Raytheon 280 etc.
   
  But when it says 322RS-3 I have not found any source yet to decipher it. What does RS stand for? Seems to be that people think that three digits (RS-3) is a 50's designation.
   
  Here is another tidbit: The TS tubes usually have "Made In USA" printed on them; sometimes straight print and sometimes slanted. "The slanting vs. not font designates "without-" vs. "with allowance in lieu of returns" status at time of sale. That's a fancy way of saying that slanting _USA_ tubes could be returned for credit for a specified period of time after sale in the event of failure. Without the slant, tubes could only be returned for credit if they were found to be "line rejects", i.e. initially defective before actually being sold/installed. So they were differentiating applications and markets and price structures at time of shipping, reflected in the printing. "
   
  "Around the end of the '50s and into the '60s they sometimes got tricky with the date codes in the "322" format and used letters instead of digits, e.g., "322RC3 . Maybe this has additional significance, maybe it was to obscure shelf life."
   
  Would appreciate it if somebody could come up with more date code information for TS tubes.


----------



## MIKELAP

Quote: 





mordy said:


> Hi Mikelap,
> 
> Here is a code chart for Tesla tubes in the Czechoslovakian language.
> From Google translate:
> ...


 
  Thanks a lot  mordy you the man.


----------



## MIKELAP

Quote: 





gibosi said:


> This is great! What a sleuth you are!
> 
> So it seems my tubes, TG = Oct 1957. And Mikelap's tubes, AN = May 1963. Only 6 years difference, but in that time they radically changed the internal construction.


 
  And thank you gibosi for the answer. Now ill go check this link out.


----------



## Audiofanboy

Quote: 





gibosi said:


> Glad to hear that they are everything you hoped for, especially given how long you had to wait! I notice that yours look somewhat different than the ones that mojorisin35 and I have. The build quality of yours clearly looks quite a bit better.... I wonder how they compare in sound?
> 
> 
> 
> ...


 

 What's interesting about these is that the plate construction is the same as my Tung Sol 6AK5 from 1943 (The American 6AK5 tubes went on to have the typical construction all the 6AK5 we see have, with squarish plates, not cylinder-like like this one; by 1944-45 there are no more cylindre-like anodes in the tubes, all squarish, making me think this type of anode is essentially the "6AK5 prototype"), so in the late 50s that kind of internal construction would have been _olde world_ tube making; which makes me think these were made with older technology and hint to late technological transfer from Czechoslovakia to the Soviet mother country, since they seem to have caught up by the 60s...
   
  Gibosi, that's a shame for your Russian 6AU6 equivalents. I'd been put off a little by non-suffixed Russian tubes, or even lightly-suffixed tubes, since my 6J3P-E, which I found quite lacking, but at least quiet. I think from now on, I would only buy Russian tubes if I can at least get an -EV/EB version, or better yet -ER and -IR (-DR seems to be a one-shot for 6N30P).
   
  In the meantime, I'm back out of the rabbit hole and I tested my *Sylvania JAN 6AH6WA* after 13+ hours of burn-in. They are nicely balanced tubes, very pleasant to listen to and quite versatile. A tad more gain than my GE 8425A/6AU6A -which they should have since they have mu = 40 instead of 36 for 6AU6- but not a huge difference; much less than an EF91 as expected. These are extremely transparent and detailed, with very realistic voices, and an excellent deep soundstage and instrument separation. Decay could be faster and mids have that ever-so-slight  warmth that makes music delicious, but then again that's why we use tubes lol. Highs have that pleasant airiness that lets details stand out naturally with instruments flying around the stage in a musical and logical way. Bass and mid-bass, and to some extent the rest of the frequency range, have a very slight graininess to them -like the GE 6GX6/6GY6- that sounds like a small amount of dithering; that keeps the sound from having absolute transparency, but it doesn't sound veiled either, just a little grainy -a little analog touch if you add what I said about the mids and decay. Ultimately, these lack a bit more punch and the low end could be a little more tactile, but they come close to being a A+ tube. I'd say a solid *A* grade tube, borderline A+, that comes close to the best. After listening to these, I'm sure there's a 6AH6 tube, maybe from earlier production years, that will eventually rival my GE 8425A!


----------



## mordy

Dear Audiofanboy,
   
  -DR seems to be a one-shot for 6N30P.  Well, here are four more types of DR tubes - don't know if they are suitable for LD MKIII:
   
   
  http://www.ebay.com/sch/i.html?_odkw=DR+tubes&_osacat=0&_from=R40&_trksid=p2045573.m570.l1313&_nkw=DR+Russian+tubes&_sacat=0


----------



## MIKELAP

Quote: 





mordy said:


> Hi Gibosi,
> 
> Glad to be of help - lucked out and found it quickly.
> 
> ...


 
   
  After about 1960, many tube manufacturers went to encrypted alphabetical date codes., such as:
  KE
  188-5
  The reason was purportedly to allow factories to track the dates of manufacture of defective tubes (especially important in the case of OEM customers that might send back entire batches of tubes), but avoid possible consumer complaints about "stale" tubes. This sounds perhaps a little silly since the shelf life of tubes is decades, at least (indefinite in practical terms), but some OEM's might have beenn a bit irritated by occasional consumer complaints such as "my 1961 model TV has 1959 model tubes in it!"
  Tubes made for the US military, or certain OEMs (such as some test equipment manufacturers) that requested it, continued to carry numerical date codes.


----------



## Audiofanboy

Quote: 





mordy said:


> Dear Audiofanboy,
> 
> -DR seems to be a one-shot for 6N30P.  Well, here are four more types of DR tubes - don't know if they are suitable for LD MKIII:
> 
> ...


 

 Fascinating, I hadn't bumped into any other -DR tubes yet, but at least that confirms that more exist. Unfortunately, non are compatible... (9-pin base and mainly triodes)


----------



## mordy

Dear Mikeleap,
   
  Just got an email that deciphers the GE  KE 188-5  code:  It means July 1971; manufactured in the Owensboro, Kentucky factory.
   
  Here is the source:
   
  [size=medium]* GE letter codes! -Or at least some of them. Check out the table:*[/size]
 
 Month 1971 1972 1973 notes Jan. CE CF CH For following years advance the 2nd letter by one alphabetically. For instance, Jan. 1974 would be CI, Jan. 1975 = CJ, etc. Note certain letters are skipped, I don't yet know which ones, but notice that the letter 'G' is skipped both for year and month. 'D' is also skipped at least for the month. Presumably you can work this backwards too. In other words, Jan 1970 would be CC (or maybe CD). Also note: 'P' and 'Q' are skipped for the month (first letter.) Does this mean they're skipped for the year (2nd letter)? When I know more I'll post it.

 For some of the 1960's they used the earlier year/week code. I'm not sure when the change-over to the two letter code occurred. You can get an idea by checking the date codes on our tube lists. Feb. EE EF EH Mar. FE FF FH Apr. HE HF HH May IE IF IH Jun. JE JF JH Jul. KE KF KH Aug. LE LF LH Sep. ME MF MH Oct. NE NF NH Nov. RE RF RH Dec. SE SF SH
    
 
 *[size=large]GE TUBE WRITING COLOR TABLE[/size]* WHITE *GE Standard Manufacturer's Warranty applies.* RED *Distributor's Warranty (sold by GE to distributors a for lower price). GE absolved of warranty.* GREEN *Export or Military. No standard US warranty.* Lt. Blue *OEM issue. Also supplied to authorized service centers for use as replacements on GE product repairs (only on per needed basis).* Partially from a 1963 GE brochure on the distributor and adjustment policy. Apparently applies only to tubes of 1950s era or later. 
  
 
 [size=medium]*[size=large]GE EIA/RETMA LOCATION CODES[/size]*[/size] [size=medium]*188-4*[/size] [size=medium]*OWENSBORO, KY.*[/size] [size=medium]*188-5*[/size] [size=medium]*OWENSBORO, KY. This is most predominate. See note.*[/size] [size=medium]*188-6*[/size] [size=medium]*SCHENECTADY, NY*[/size] [size=medium]*188-20*[/size] [size=medium]*SCHENECTADY, NY*[/size] [size=medium]*188-21*[/size] [size=medium]*SCHENECTADY, NY*[/size] [size=medium]*188-22*[/size] [size=medium]*SCRANTON, PA*[/size] [size=medium]*In later years Canadian and other imported tubes carried the common 188-5 code. Apparently Owensboro began assuming responsibility for all tubes even if made in other factories. Theirs or purchased tubes. *[/size]
                      
  Thanks to Charlie from Pax-Comm.com


----------



## gibosi

Quote: 





mordy said:


> [size=medium]* GE letter codes! -Or at least some of them. Check out the table:*[/size]
> 
> Month 1971 1972 1973 notes Jan. CE CF CH For following years advance the 2nd letter by one alphabetically. For instance, Jan. 1974 would be CI, Jan. 1975 = CJ, etc. Note certain letters are skipped, I don't yet know which ones, but notice that the letter 'G' is skipped both for year and month. 'D' is also skipped at least for the month. Presumably you can work this backwards too. In other words, Jan 1970 would be CC (or maybe CD). Also note: 'P' and 'Q' are skipped for the month (first letter.) Does this mean they're skipped for the year (2nd letter)? When I know more I'll post it.
> 
> For some of the 1960's they used the earlier year/week code. I'm not sure when the change-over to the two letter code occurred. You can get an idea by checking the date codes on our tube lists. Feb. EE EF EH Mar. FE FF FH Apr. HE HF HH May IE IF IH Jun. JE JF JH Jul. KE KF KH Aug. LE LF LH Sep. ME MF MH Oct. NE NF NH Nov. RE RF RH Dec. SE SF SH 
   
  This is a very useful table in some cases. But recently, with my 8425A/6AU6, it doesn't seem to be valid. These tubes have the following codes printed on the tubes: "NW 188-21 67-32". Extrapolating from the table above NW = Oct 1988. But then there is the more traditional date code 67-32 which clearly appears to be the actual date of manufacture. My 6485/6AH6s also appear to be 1960s vintage, but the tube code is ""NV 188-5"... October 1987? I don't think so....  So in these two cases, it would appear that these two-letter codes are not date codes. But their actual meaning remains a mystery to me....


----------



## mordy

I agree that the chart is of limited use. At least you know that the first tube was made in Schenectady upstate New York....


----------



## gibosi

Quote: 





mordy said:


> I agree that the chart is of limited use. At least you know that the first tube was made in Schenectady upstate New York....


 
   
  And it may be that you cannot extrapolate from that table more than a couple years either way. Perhaps in the 1960s, there was a different sequence of date codes. For example, on my 8425As, I am wondering, if for some reason, both types of date codes were placed on these tubes, that is "NW = October 1967". And in that case, I would feel fairly confident in thinking that NV = October 1966 for my 6485s. Just a guess, but certainly possible.


----------



## Acapella11

Hey guys. I am keeping a bit low key at the moment. But there is something else I want to say. Just a little compliment. Do you know how pleasant this threat is? Civil, redundant within reason, people contribute instead of bash opinions. It is my favourite thread, actually.


----------



## mordy

Hi A11,
   
  Agree, it is a treat to read the various contributions, and especially about the new types of tubes that I never knew about that could be used in the LD amps. These new tube types bring me additional listening pleasure, and most of them I am able to find real inexpensive.
  Thanks to all contributors!


----------



## MIKELAP

Same here guys this thread is the best. Being retired i come here several times a day just to check for something new. Thanks for contributing to my knowledge of the hobby.


----------



## gibosi

It has been great fun following Audiofanboy on this journey through the great and wonderful land of unknown tubes. I am also retired and now have a little more time to play, but I may need to get another job to properly fund my current tube buying habit!


----------



## MIKELAP

Quote: 





gibosi said:


> It has been great fun following Audiofanboy on this journey through the great and wonderful land of unknown tubes. I am also retired and now have a little more time to play, but I may need to get another job to properly fund my current tube buying habit!


 
  Yes it as been very interesting.but its affortable at least. i had a burson 160ds amp that i sold last week to help fund my new Burson Conductor that i got today should be good for a while i hope. This thing sounds incredible but i love my tubes theres something about tubes .i was checking out if i could use the dac out of the burson and plug it in the imput jacks of the littledot its a far better dac than my essence stx  soundcard. would you know if that would work dont want to risk damaging it if at all.


----------



## gibosi

Quote: 





mikelap said:


> Yes it as been very interesting.but its affortable at least. i had a burson 160ds amp that i sold last week to help fund my new Burson Conductor that i got today should be good for a while i hope. This thing sounds incredible but i love my tubes theres something about tubes .i was checking out if i could use the dac out of the burson and plug it in the imput jacks of the littledot its a far better dac than my essence stx  soundcard. would you know if that would work dont want to risk damaging it if at all.


 
  I cannot imagine that it wouldn't work great. I have no experience with this unit, but I took a look on Burson Audio's webpage and I see that it has "DAC out" RCA jacks. Just connect those outputs to your Little Dot "Audio In" jacks. I am using an inexpensive little headphone DAC/Amp, a Fire Phoenix DAC-02, and in the same way, I connect the DAC out jacks to my Little Dot audio in. Works great!


----------



## MIKELAP

Quote: 





gibosi said:


> I cannot imagine that it wouldn't work great. I have no experience with this unit, but I took a look on Burson Audio's webpage and I see that it has "DAC out" RCA jacks. Just connect those outputs to your Little Dot "Audio In" jacks. I am using an inexpensive little headphone DAC/Amp, a Fire Phoenix DAC-02, and in the same way, I connect the DAC out jacks to my Little Dot audio in. Works great!


 
  Thanks a lot i just tried it littledot sounds a lot better this amp is paying off already.


----------



## gibosi

Quote: 





mikelap said:


> Thanks a lot i just tried it littledot sounds a lot better this amp is paying off already.


 
  I'm not surprised! Upgrading a DAC can be just as dramatic as swapping out tubes. And the Burson Conductor looks to have a top notch DAC, a major upgrade. So with the new DAC and those new Teslas, your Little Dot must be very happy!


----------



## mordy

Hi all,
   
  I am also retired, and I just would like to quote friend of mine who asked me what I am doing. I told him that I am retired. He answered: You are not retired, you are re-tired, rolling along!
  
  Anyhow, decided to try the 6AU6A tubes. A friend gave me a little piece of wire which I cut to size and inserted in the sockets as per picture. Changed the jumpers to EF95 setting and plugged in the tubes. (Used my stainless steel tweezers with good results.)
   
  Did not know if these tubes would work for me, so I ordered the least expensive GE tubes that I could find, less than $3 each, including shipping. A few days later I got a pair in the mail. These were made by RCA and had the name Bogen on them. Manufacturing date 1964-37; both the same. Oh well, what do you expect for 99c each +shipping? (Bogen made mainly commercial tube amps in the late 50's and early 60's. The brand exists today making PA amplifiers.) The original factory was in NJ, but there is nothing left of the factories - it is today the site of the Bergen Mall. Same fate for Tung Sol - nothing left except urban blight in Newark, NJ. Why can't I find much of the history of these manufacturers?)
   
  Burned in the tubes for around 30 hours. First impression: the heaters are so dull and hidden that I cannot tell if the tubes are on from where I am sitting. I have to touch them to know that they are on - they get somewhat hot but not burning hot.
   
  Listening: First impression enormous sound stage - on some recording the sound emanates from outside the right and left speakers! With the present setup in my room I cannot move my listening chair back far enough to get a center image - it is as if I am listening to two halves of the recording. Have to work on getting the sound stage right.
                  Second impression: Extremely clean and detailed bass and low register. It is as if I brought home a refrigerator sized sub woofer instead of the 10" ones I have.
                  Third impression: The mid range is not the sweetest, and the top end too bright. I have turn down the treble on my receiver to counteract the excessive brightness.
   
  In summary: Fantastic tubes! Now I am just waiting to compare to the Tektronix matched tubes that I ordered.....


----------



## Audiofanboy

Quote: 





mordy said:


> Hi all,
> 
> I am also retired, and I just would like to quote friend of mine who asked me what I am doing. I told him that I am retired. He answered: You are not retired, you are re-tired, rolling along!
> 
> ...


 

 Glad to see you had the same kind of impressions Gibosi and I had about the 6AU6 tubes! There is great potential in that tube family -at a fraction of the cost of the best 6AK5 and EF92/91s- and ample supply to last for a few decades. About your matched Tek pair, did you get 8425A/6AU6A tubes? After testing quite a number of similar tubes of different families in the past couple of weeks, there is at least one conclusion I've reached: the industrial/computer rated tubes are usually the best the US manufacturers made, often better than the mil spec versions. Which makes perfect sense in a way; on a Tek oscilloscope, you'd need matched high quality (read hi-fi) signal tubes -sometimes in parallel by lots of 14 or 16!- that just keep on being high quality but less and less powerful until they are replaced by whole lots, whereas military tubes just need to be reliable, i.e. not replaced often -"will keep on sounding the way they do for a long time" or so someone mentioned here a few pages ago.
   
  Anyway, if I were to try another US tube type right now, I'd get an industrial/computer type, and I'd get it in that order (knowing that the tubes may not be that different but just more or less "selected"):
  - Industrial company certified or matched (like the Tektronix tubes)
  - Industrial military (not necessarily mil spec then; for the 6AU6 family,  the 8425A are industrial/computer rated but the 6136 and 6AU6WA/B/C are "just" premium/mil spec tubes)
  - Industrial "consumer" grade (which probably aren't really consumer grade though)
   
  Hoping this helps someone's fleebay adventures...
   
  Edit: Sadly, I am not retired nor close to being retired by any fair margin, hence my irregular posting lately...


----------



## MIKELAP

Quote: 





audiofanboy said:


> Glad to see you had the same kind of impressions Gibosi and I had about the 6AU6 tubes! There is great potential in that tube family -at a fraction of the cost of the best 6AK5 and EF92/91s- and ample supply to last for a few decades. About your matched Tek pair, did you get 8425A/6AU6A tubes? After testing quite a number of similar tubes of different families in the past couple of weeks, there is at least one conclusion I've reached: the industrial/computer rated tubes are usually the best the US manufacturers made, often better than the mil spec versions. Which makes perfect sense in a way; on a Tek oscilloscope, you'd need matched high quality (read hi-fi) signal tubes -sometimes in parallel by lots of 14 or 16!- that just keep on being high quality but less and less powerful until they are replaced by whole lots, whereas military tubes just need to be reliable, i.e. not replaced often -"will keep on sounding the way they do for a long time" or so someone mentioned here a few pages ago.
> 
> Anyway, if I were to try another US tube type right now, I'd get an industrial/computer type, and I'd get it in that order (knowing that the tubes may not be that different but just more or less "selected"):
> - Industrial company certified or matched (like the Tektronix tubes)
> ...


 
  Chanceux.


----------



## mordy

Hi Audiofanboy,
   
  I bought a pair of Tektronix matched selected tubes, (as per your suggestion) and this is what the seller wrote me regarding the regular 6AU6A and the Tektronix:
   
  [size=10pt]"Checked tubes were hand selected for certain characteristics that sometimes included greater transconductance which may mean a longer life. Checked and selected tubes were the highest grade tubes tubes Telefunken could find for the very high end machines they were making. I always find "Checked" and "Selected" tubes to be stronger, and have great sound. Does it mean the unchecked tubes don't sound great? No. I would opt for checked tubes in a 6au6 for a few dollars more. I hand test and select these tube and make sure they match. Hope that helps.[/size]"


----------



## gibosi

Quote: 





mordy said:


> These were made by RCA and had the name Bogen on them. Manufacturing date 1964-37; both the same. Oh well, what do you expect for 99c each +shipping? (Bogen made mainly commercial tube amps in the late 50's and early 60's. The brand exists today making PA amplifiers.) The original factory was in NJ, but there is nothing left of the factories - it is today the site of the Bergen Mall.


 
  I remember Bogen! I was in a rock band in the 1960s and Bogen PA systems were very common at that time. I had no idea this company was still in business and making PA systems today.
   
  And of course, I am glad that your RCA 6AU6s are "fantastic"! Similar to you, I first bought some cheap standard GE 6AU6s and was so impressed, I immediately purchased a pair of 8425As. These are still my No 1 tubes, but then, we don't know what unknown tubes Audiofanboy is planning to audition next.


----------



## mab1376

Am i the only one on this thread on their 20's? LOL


----------



## Audiofanboy

Quote: 





mab1376 said:


> Am i the only one on this thread on their 20's? LOL


 

 Nope, I'm in my 20s too lol, albeit late 20s, but still.
   
  Mordy, I wouldn't be surprised if these, while etched 6AU6A -like my and Gibosi's 8425A- were also silk-written 8425A underneath the Tek tag, since it appears that's what they used. At any rate, these should be fabulous tubes!


----------



## mordy

Hi Audiofanboy,
   
  The ones I ordered are listed as 8425A/6AU6A GE NOS 60's Tektronix tubes. The picture just shows two tubes with the Tektronix label and numbers, but I am pretty sure that these are the ones. Paid less than $6:50 each including shipping, which make these tubes the 2nd most expensive tubes I bought. Should be here in a couple of days and will report back when I try them out.
  
  The RCA Bogen tubes are dated 1964 which seems a little strange since one source stated that tube amp production seized in 1963. Tidbit: Found a post that said that if you ordered 1000 tubes or more you could get your name on them.
   
  As I am writing this, I am listening to these tubes now and I am marveling at the clarity and bass. They tubes seem to have improved - is it possible that they require a longer break in period than say 30 hours?


----------



## MIKELAP

Quote: 





mab1376 said:


> Am i the only one on this thread on their 20's? LOL


 
  Ya your the lucky one lol .


----------



## Acapella11

Seems I hit the age kind of in the middle between you two groups.
   
  Actually, I wrote a mail to Dept_of_Alchemy to ask whether he could edit his opening post to to point at the the workable but not officially supported families of tubes but it seems he hasn't been active for a while.
   
  I try to refrain from my tube rolling addiction these days but I am not sure I can overcome it fully. *Cautious look at the 6AU6A tubes*


----------



## mab1376

I got my 6AU6A tubes, I just need to make a jumper to be able to use them, also need to swap back to the 6AK5 setting.


----------



## gibosi

Quote: 





mab1376 said:


> I got my 6AU6A tubes, I just need to make a jumper to be able to use them, also need to swap back to the 6AK5 setting.


 
   
  And of course, we are all waiting....


----------



## inphu510n

acapella11 said:


> Seems I hit the age kind of in the middle between you two groups.




I think I'm more in the middle here. I'm in my early 30's.

I've been lazy about trying my new tubes with the amp as I've been more busy lately. I'll get around to creating jumpers some day. I'm really considering just soldering a 26GA wire between the pins to be sure I don't create a poor jumper connection.


----------



## Audiofanboy

inphu510n said:


> I think I'm more in the middle here. I'm in my early 30's.
> 
> I've been lazy about trying my new tubes with the amp as I've been more busy lately. I'll get around to creating jumpers some day. I'm really considering just soldering a 26GA wire between the pins to be sure I don't create a poor jumper connection.



Good luck with soldering a wire on tube pins, those crappy oxidized metal pins are a real b**** to solder on... I tried it, failed, cleaned the tube pins thoroughly -had to use sand paper- retried and succeeded -albeit in a soldering shape that would have had trouble fitting into the socket. When I tried it again on real tubes -I tested on dead ones first- I still had trouble getting the solder to hold well.

I found the "pin mod" at the socket level to be not only way easier and flexible, but also just giving a better mechanical connection -the copper strands going down in socket hole end up wrapping around the tube pins along their whole length squeezed between socket hole and pin. So long as the the tubes stands straight, they really can't move and the wire definitely can't go anywhere.

Honestly, if I plug in EF92/91 tubes again, I think I'll just leave the jumpers on the 6ak5 setting and pin mod pins 6+7, as it saves me from flipping the amp around and fiddling inside it, which just can't be that good over the long term...


----------



## gibosi

These showed up in today's mail: GE 6136/6AU6WB, 1960s vintage. There are no date codes on the tubes or the boxes, so the exact year is unknown.
   

   
  I had been wanting to try a high quality 6136 and thought these just might fit the bill. The most noticeable difference is the black plates. They are burning in now, but first impressions, these have the classic 6AU6 sound and everything is good.


----------



## Audiofanboy

Quote: 





gibosi said:


> These showed up in today's mail: GE 6136/6AU6WB, 1960s vintage. There are no date codes on the tubes or the boxes, so the exact year is unknown.
> 
> 
> 
> I had been wanting to try a high quality 6136 and thought these just might fit the bill. The most noticeable difference is the black plates. They are burning in now, but first impressions, these have the classic 6AU6 sound and everything is good.


 

 Yeah, definitely curious about how these sound, as they have those "black plates" that I've around on all the premium 6136s from the best years; I only got to try the later -also mil-spec- 6136 etched ones, and was disappointed... I also wonder how these fare compared to the exactly similar looking 5-star GE 6136 -unless they are actually identical- since up to now we've often found differences between military -let alone mil-spec- tubes and others...


----------



## gibosi

A pair of Sylvania 5749/6BA6Ws from the early 1960s arrived yesterday.
   

   
  These are remote-cutoff pentodes, as opposed to sharp-cutoff pentodes. Generally, remote-cutoff pentodes are not considered suitable for audio amplifiers. However, I believe this is based on the assumption that they will actually be used as pentodes. When we strap these as triodes, it is hard to predict how they will behave. Since these are really cheap, I thought why not give them a try?
   
  I have listened to them for only a short time and been pleasantly surprised at how musical these sound. However, I don't want anyone to think that they should abandon their 8425As for these! LOL But still, a very pleasant surprise. And again, they are really cheap!


----------



## ostewart

My friend just told me the Little Dot MKII+ looks like a coffee machine, haha


----------



## mordy

Hi All,
   
  Today my Tektronix 8425/6AU6 tubes arrived. Pulled out my 6AU6 RCA/BOGEN tubes and put in the new ones. As mentioned by others, I had to re straighten and reposition one of the jumper wires, but now everything makes good contact.
  The first impression is the 6AU6 "house sound" of extreme clarity and punch in the bass. In comparison to the RCA tubes, these 4825 GE tubes are sweeter and more extended in the bass and the treble, and less bright in the upper register. I can also turn up the volume control on the LD higher without clipping. (I have it on the 3 o'clock setting.)
   
  The heaters are brighter than the RCA's, and I can tell that the tubes are on by looking at them.
   
  The sound is absolutely beautiful, even after only 6-7 hours of burn in. Everything sounds better, and I constantly hear new details in the music. At high volume a well recorded tune with kick drum sounds effortless with huge slam, heft and authority in the bass.
   
  If you read through the posts about the LD MKIII amp you come across various favorite tubes from various people: Sylvania Gold Pin, Amperex Bugle Boy, Tung Sol etc etc. All these types are available as 6AU6 variants. However, I can't really think of better tubes than these Tektronix tubes.
   
  I do notice that Hi-Fi tube tuner and amplifier manufacturers like Fisher and McIntosh used the 6AU6 tube in their products.


----------



## Audiofanboy

mordy said:


> Hi All,
> 
> Today my Tektronix 8425/6AU6 tubes arrived. Pulled out my 6AU6 RCA/BOGEN tubes and put in the new ones. As mentioned by others, I had to re straighten and reposition one of the jumper wires, but now everything makes good contact.
> The first impression is the 6AU6 "house sound" of extreme clarity and punch in the bass. In comparison to the RCA tubes, these 4825 GE tubes are sweeter and more extended in the bass and the treble, and less bright in the upper register. I can also turn up the volume control on the LD higher without clipping. (I have it on the 3 o'clock setting.)
> ...



Those are some very nice tubes Mordy! Out of curiosity, and since we do need to able to grade all those tube types on an absolute scale, would you say then, in your opinion, that the 8425A are superior -best you've heard- to all the other types you've tried up to now, or just equal in listening pleasure to tube X and Y -what you fill in the blanks is what we're interested in of course lol?

It seems everyone on google or fleebay is looking for the famous Telefunken in the 6AU6 family, which are now -obviously- grossly overpriced. The very close -I'm sure as good- second are supposed to be the Mullard Blackburn UK-made variants of the 6AU6/EF94, although most people keep looking for Amperex Bugle Boys and other very-famous-brands which were made by... Oh wait, Mullard Blackburn... So many tubes, while great are looked down upon because of their non-famous branding, though made in the same factory. Many of the better regarded 6AU6 brand or brandings, including a lot of the Fisher, McIntosh, Eico, Amperex (Phillips Holland "Orange Globe" could be better than the Bugle Boys made by Mullard UK) and I suspect some Telefunken, can all be traced back to that same Mullard factory -itself highly regarded for its 12AX7 and 12AT7 and many more famous-signal-tubes if I recall; all the UK tubes I'd had up to now were from Mitcham or Whyteleafe, Blackburn made tubes are supposed to be great.

So, it's funny you'd mention those typically well regarded brands at this point Mordy since my current goal is to get to try a few of these without paying the prime price. Looking at auctions and ads for different 6AU6, I managed to score some very nice looking Valvo -Philips group like Mullard, see where this is going?- EF94 tubes just below the $8 per tube including shipping cut-off, in their West German military boxes (how unusual is that lol?) made in 1966 by... oh wait... Mullard Blackburn (I know from the tube construction and factory codes despite the labels)! So instead of paying $20x2 for used pulls from old Fisher amps, made by Mullard but labeled Fisher or often two different paired amp brands in the same ad, I got four of these, and they look much better than the crappy used Mullard made 6AU6 all over fleebay -being NOS NIB and all.

As per usual, I'll try and report back when I get them, and compare them especially to the 8425A; it's been a while since I've tried a new UK tube, particularly for the "new" old tubes types, so this should be very interesting!


----------



## mordy

The Tektronix are the best overall I tried - I don't think there is any going back to the 6AJ5 Tung Sol that like the best before these - these are so superior to all the others.
   
  Curious what you are going to find out about the Mullard 6AU6 variants. In my quest for the perfect 6AK5 tube I tried many of these variants and did find nice ones but still the US tubes came out on top at the end.
   
  I found that patience pays off with E-Bay. If you wait long enough you will find exactly what you want at the right price. The trick is to get a a non greedy seller that does it for a hobby and not for a business. Many times I got more bargains by writing to the seller and asking if he has this or that, or asking for a better price if I bought a couple of more pairs. It also pays to buy lots. Keep what you want and resell the ones you can't use.
   
  Re 6AU6 tubes: Personally would be interested in Dutch Amperex and mil spec Sylvanias from the late 60's - early 70's. (I found that the cheap mil spec Sylvania tubes sounded exactly the same as the gold pin ones from the same time, but at a fraction of the price.) Did not have much luck with Raytheon tubes except for a 50's 6AK5 tube that had the internal assembly suspended on the bottom pins with the mica rings not touching the glass - excellent sounding. Then the intriguing Tung Sol with the clear top and getter flash on the side of the tube....
   
  Back to the Tektronix - I am amazed how loud I can play without being listening fatigued (speakers only). The bass is loud and very powerful, but not booming or bloated - just tuneful and detailed. Could it be that the RCA sound stage is a little wider?
   
  However, I am perfectly satisfied with what I have now. I am listening to the music or the equipment?.......


----------



## Battlescarze

Its always the equipment, no two instruments sound identical...there is always some variant...even in modern mass production.
   
  When you find yourself just listening to the music without thinking about the equipment I would say "you are there"!!


----------



## mordy

"Marvelling at the sound listening to the music!"


----------



## Audiofanboy

mordy said:


> The Tektronix are the best overall I tried - I don't think there is any going back to the 6AJ5 Tung Sol that like the best before these - these are so superior to all the others.
> 
> Curious what you are going to find out about the Mullard 6AU6 variants. In my quest for the perfect 6AK5 tube I tried many of these variants and did find nice ones but still the US tubes came out on top at the end.
> 
> ...




The Tung Sol 6AJ5 was a very nice tube with a guaranteed pleasant listen, but like many 6AK5-ish tubes, I had ultimately found it lacked the absolute details and was a bit soft on the attack. Again, after testing so many other tube types, I just can't see a single reason to go back to the 6AK5 family... This was already somewhat the case for me after spending time with the CV4015, and even moreso a few months later with the GEC CV4014, but some of these new tube types just blow the amp away! I am done with the 6AK5s -otherwise very nice for a trouble free basic headamp- apart from the occasional thrill of testing one or two amusing ones I might get by buying lots, like the earliest Tung Sols with the side getter flash, but that's it for me...

Never did find any redeeming value in the Raytheon tubes I tested, and those with the floating structure -apart from being 6AK5s I said I wouldn't buy anymore lol- are just too rare and/or expensive to be worth it now -and some people reported them to be sibilant, which I just can't live with.

On 6AU6 tubes, you can actually get Amperex "orange globe" ones made by Philips Holland for an "acceptable price", however that would usually fall above the $8 per tube psychological limit. And there many kinds of Amperex, some made by GE, the Bugle Boys made in the UK... The 6AU6 tubes aren't that obscure apparently, and many have been searched for for a decade or more on the web already... I've read nice thing about the Sylvania 6AU6 on like... one google link, which is better than nothing. When you can't find much information about something on google, it means you've gone pretty far in a specific domain or hobby lol...


----------



## mordy

There is always more information on Google; you just have to be creative where to look. To find more out about the 6AU6 tubes, I would explore people who write about guitar amps and people who build DIY radio/amp projects.
   
  The next logical step is to write to David ZheZhe and ask him to design the Little Dot MkIIIi AFB edition with built in switches for the 6AU6 tubes. A little toggle switch on the front or the back panel would be a nice touch (no more dealing with pesky jumpers).


----------



## mab1376

I personally really like the Raytheon 6GX6, I gave it a few days of use before my GEC CV4014's came in.

To me its like the smoothness of the 6AJ5 combined with the clarity of the M8161, I have been using the CV4014s more due to the high gain which sounds very good with metal and industrial, but for more mellow music like the black keys for instance I prefer the 6GX6.

Unfortunately I haven't had the time or inclination to test the 6AU6A tubes yet.



mordy said:


> There is always more information on Google; you just have to be creative where to look. To find more out about the 6AU6 tubes, I would explore people who write about guitar amps and people who build DIY radio/amp projects.
> 
> The next logical step is to write to David ZheZhe and ask him to design the Little Dot MkIIIi AFB edition with built in switches for the 6AU6 tubes. A little toggle switch on the front or the back panel would be a nice touch (no more dealing with pesky jumpers).




If anyone figures out a easy elegant solution to not have to use jumpers anymore that would be fantastic!

I hate those things!


----------



## Acapella11

Quote: 





audiofanboy said:


> The Tung Sol 6AJ5 was a very nice tube with a guaranteed pleasant listen, but like many 6AK5-ish tubes, I had ultimately found it lacked the absolute details and was a bit soft on the attack. Again, after testing so many other tube types, I just can't see a single reason to go back to the 6AK5 family... This was already somewhat the case for me after spending time with the CV4015...


 
   
  This!
   
   
  Quote: 





> Originally Posted by *mordy*
> 
> 
> 
> The next logical step is to write to David ZheZhe and ask him to design the Little Dot MkIIIi AFB edition with built in switches for the 6AU6 tubes. A little toggle switch on the front or the back panel would be a nice touch (no more dealing with pesky jumpers).


 
   
  And this!
  Also, include the other families of tubes as compatibles, which are workable with the EF91/92 jumper setting, as e.g. the 6EW6.
   
  So, I am going to get a pair of 6AU6s after all the discussion. Curiosity wins.


----------



## mab1376

David should give you all with free products for all your hard work documenting what's compatible with his product line! 

it certainly had way more value in my eyes after trying all these new awesome tubes!


----------



## mordy

Dear A11,
   
  You won't regret getting the 6AU6 tubes. Please let us know your impressions once you've tried them.
   
  My Tektronix have now been on over 24 hours non stop. At this point they have mellowed out a little with the too bright edge in the treble gone. They also run cooler than the RCAs.  When I drag in other family members into my listening room they all notice the crispness and impact of the presentation (OK - so I demo a drum solo at full blast).


----------



## Acapella11

Hard to not get intoxicated by you guys


----------



## gibosi

Quote: 





acapella11 said:


> Hard to not get intoxicated by you guys


 
   
  I have been wondering how long it would take you to finally jump in! And as you will soon see, the water is fine! LOL


----------



## mordy

About jumping in - you need the jumpers for the sockets. I am sure that you are going to research the benefit of using 100% OFC multi stranded 30 gauge pure copper wire. However, in case you don't have this (like me), take a look inside an old abandoned PC computer case and see if there is a thin wire connector there - there should be plenty of choices.
  My wire is silver stranded and once put in place with a tweezers works just fine - I don't think it's even copper.
   
  Good luck!


----------



## gibosi

And to give you another option, I have been successfully using solid core 30 gauge wrapping wire. I would guess that as long as it is sufficiently small, most any wire will work.


----------



## mordy

Here is the stainless steel anti static tweezers (for changing jumpers) on sale with a coupon code for 60c including shipping and tax. If you want it don't wait to order it, because it will be gone. Make sure to use the coupon code and check free shipping.




http://www.meritline.com/high-precision-anti-static-stainless-steel-tweezers---p-43059.aspx?strcoup=MLCKA05WNL1&dealid=55393


----------



## Acapella11

Thanks Mordy and Gibosi for the ideas. I searched through my old PC inventory and of course there were lots of cables. I found a thin one, which was from an internal output of a network card, guess no one would ever use that again. So, I got two jumpers ready.  My pointy nose pliers seem to work fine changing them. Now, I just need the tubes to try them.


----------



## gibosi

As promised I have tried to compare my 8425A/6AU6s and my 6136/6AU6WBs, both manufactured in the mid 1960s by GE.
   

   

  As you can see, there are some structural differences. Obiously, the 6136s have black plates with two squarish holes while the 8425As have gray plates with three roundish holes. Also, of interest, the 6136s appear to have two layers of mica, top and bottom, compared to one layer for the 8425As. Other than that, these tubes appear to be virtually identical to my eyes.
   
  To audition these tubes, I used a few tracks off of Eric Clapton's Unplugged album and another track I have grown very fond of, Ain't Nobody's Business with Willie Nelson and Wynton Marsalis:
   
  https://www.youtube.com/watch?v=aDJIwVPimyg
   
  These tracks have real instruments and real voices in real spaces, I would hope that they would be able to reveal any sonic differences, providing my test and measurement apparatus - "rusty ears and cheap gear" - are sophisticated enough to recognize them. LOL 
   
  Playing through these tracks, as I feared, my testing apparatus was unable to discern any sonic differences. However I think it is worth pointing out that both of these are premium tubes manufactured by GE in the same time frame, so one could postulate that they may well share a very similar sound. I am hopeful that others of you, with better ears and equipment, will have a chance to listen to these and let us know your impressions. To my ears, both of these are very fine tubes. Highly recommended.
   
  Curiously, I have been burning in a pair of Tung Sol 6AU6WAs from the mid 1950s and I do believe that the mid range on these Tung Sols seems to be just a bit more forward than the GEs... but I fear I may be getting tired...  so I should spend more time with them to be sure....


----------



## vic2vic

Quote: 





acapella11 said:


> Thanks Mordy and Gibosi for the ideas. I searched through my old PC inventory and of course there were lots of cables. I found a thin one, which was from an internal output of a network card, guess no one would ever use that again. So, I got two jumpers ready.  My pointy nose pliers seem to work fine changing them. Now, I just need the tubes to try them.


 
   
  I have some 6AU6W tubes on the way and need to figure out something for the jumper. I guess the PC cables used to power on floppy discs, cd, dvd, hd, etc. (taking one of the 4 wires) are still too big to fit in the socket, correct ?
  What about "sacrificing" some unused earphones (e.g. stock ones that came with sansa clip+) ? The cable going to to each earpiece should contain 2 wires small enough to be used as jumper (or are they too small) ?


----------



## gibosi

Quote: 





vic2vic said:


> I have some 6AU6W tubes on the way and need to figure out something for the jumper. I guess the PC cables used to power on floppy discs, cd, dvd, hd, etc. (taking one of the 4 wires) are still too big to fit in the socket, correct ?
> What about "sacrificing" some unused earphones (e.g. stock ones that came with sansa clip+) ? The cable going to to each earpiece should contain 2 wires small enough to be used as jumper (or are they too small) ?


 
   
  I have used 28 gauge stranded wire, 28 gauge solid core wire and 30 gauge solid core wire. I wonder if your headphone wires are smaller than that? But even so, I seriously doubt that they are too small. Usually the problem is that the wire is too big preventing the tube from seating in the socket properly. So I would say go for it!


----------



## gibosi

More on blackplate GE 6136/6AU6s...
   
  I had another pair of black plate GE 6136s arrive today. These are not 6136/6AU6WB tubes, just standard 6136.
   

   

  But they look identical to my 6136/6AU6WBs, even down to the double thickness of mica. Judging from a visual inspection, there is no significant difference between these newly arrived standard GE 6136 and my 6136/6AU6WB.
   
  With their arrival today, I began to look more closely at my 6136/6AU6WBs and discovered that this "matched" pair are not exactly the same:
   

   
   

   

   
  Notice that one has two squarish holes and the other two roundish holes. Moreover, one has etched "6136" and the other "6136 USA". So there is some variation, but in the end, these all appear to be the same tube.
   
  As some of you may be out there searching for these, thought this little bit of info might be helpful....


----------



## gibosi

While many of you have Little Dot IIIs and IVs, I have a Little Dot 1+. The LD1+ is a hybrid/tube amp. That is, the tube stage sits in front of a solid state amplifier. But the difference is actually quite a bit deeper than that. In the III and IV, the driver tube is used as an amplifier to provide gain. In the 1+ the tube stage provides no gain, and in fact, actually provides a slight negative gain. The tube finds itself in a cathode follower configuration and thus the output is something on the order of 1, 2 or 3% lower than the input. Thus, the tube stage acts as a buffer, and not as an amplifier. In fact, the tube stage can be completely bypassed with a straight wire, and the amp will work absolutely fine, but as a solid state amplifier.
   
  One consequence of using the tube stage as a buffer, and not as an amplifier, is that the 1+ can use tubes that would likely be completely unacceptable in the III/IV. A couple of pages ago, you might remember that I tried out a 6BA6. This is a remote-cutoff pentode that likely would distort very badly if used in the III/IV.
   
  So why am I telling you this? LOL.  Well, I never really thought the 6BA6 would be a great sounding tube. I found a pair of 1947 NIB/NOS 6BA6s. Why did that get my attention? Well, I was born in 1947, and I thought, how cool would it be if I could run these in my Little Dot? So I ordered some cheap ones first, to make sure I wouldn't be wasting my money, and they actually sounded pretty good. Not 8524A good, but still pretty good.
   
  And so.. here are my new treasures:
   

   
   

   
   

   
  They are in better shape than I am! LOL


----------



## gibosi

Sunday afternoon, I was able to spend more time with the 1956 Tung Sol 6AU6WAs.
   

   

  Using the GE 8425As as my reference, I allowed myself to be serenaded by Eric Clapton, Willie Nelson and Winton Marsalis. At first, I though the Tung Sols were just a bit brighter, more air, but then I realized that the midrange, horns and vocals, were a bit more subdued. Otherwise, they have the classic 6AU6 sound, clean, detailed and powerful. I prefer the warmer sound of the 8425As, but if others find those too warm, the Tung Sols might be a good choice.
   
  Next up, two pairs of 1950s Sylvanias:
   

   
   

   
  I noticed that the plates and getters are different in these two pairs, even though manufactured only three years apart.....

   
  Like Mordy, I often write to the eBay vendors. I ask lots of questions. And some of them are quite friendly and others are not so friendly, to put it politely. LOL. The vendor I purchased the GE black plate 6136/6AU6WBs is one of the friendly ones. He was very interested to learn I was using these in a Little Dot and he offered that he might have some interesting 6AU6s for me. And sure enough, I now have these Tung Sols and Sylvanias.
   
  The Sylvanias with red are burned in and have started to burn in the second pair. Hope to be able to post some impressions in the next day or two.


----------



## mordy

Hi Gibosi,
   
  Curious about the Sylvanias - in my odyssey to find the perfect 6AK5 tube for the LD MKIII I found that the Sylvania tubes had a very large sound stage and were quite good overall. Ultimately I preferred the Tung Sols and Mullards. Could it be that the differences are smaller with the 6AU6 tubes than the tubes from the 6AK5 family?
   
  Another curiosity is that the prices on eBay for the Tektronix 8425/6AU6 tubes are not very different than the prices for regular 6AU6 tubes (when bought judiciously).
   
  I am getting used to the Tektronix tubes. After 50 hours plus they sound better than ever, and the powerful detailed bass is constantly noticeable. The mid range has improved as well as the treble, being more mellow.
   
  With the risk of arousing the ire of members of this blog, I am submitting what I consider a great recording to listen to and enjoy. Best when cranked up loud!
   
  http://www.youtube.com/watch?v=1JJa5TlLqss


----------



## gibosi

Quote: 





mordy said:


> Curious about the Sylvanias - in my odyssey to find the perfect 6AK5 tube for the LD MKIII I found that the Sylvania tubes had a very large sound stage and were quite good overall. Ultimately I preferred the Tung Sols and Mullards. Could it be that the differences are smaller with the 6AU6 tubes than the tubes from the 6AK5 family?
> 
> With the risk of arousing the ire of members of this blog, I am submitting what I consider a great recording to listen to and enjoy. Best when cranked up loud!
> 
> http://www.youtube.com/watch?v=1JJa5TlLqss


 
   
  In my experience so far, the differences among different brands of 6AU6s are a good bit more subtle than we are used to among the 6AK5s, but they do exist, witness your experience with RCAs and GEs and my experience with Tung Sols, GEs and Sylvanias.
   
  And I seriously doubt that you have raised the ire of anyone in this forum! LOL. And while this recording isn't exactly my cup of tea, the fact the fact that these are real instruments in a real live space makes this a great test tract.


----------



## Acapella11

Quote: 





> Originally Posted by *mordy* /img/forum/go_quote.gif
> 
> With the risk of arousing the ire of members of this blog, I am submitting what I consider a great recording to listen to and enjoy. Best when cranked up loud!
> 
> http://www.youtube.com/watch?v=1JJa5TlLqss


 
   
  You are not irating anyone. Music is what the gear is for, so it is fun to listen to new music one hasn't tried before. Says me, while I am listening to the link and I even have a stage setup reference 
   
  Thanks for sharing.
   
  This is a bit slower and a singer/songwriter style. Nice on the LD though:
  http://www.youtube.com/watch?v=Dz1g9_NlS9o
   
  Enjoy =)


----------



## HeatFan12

Hi gibosi,
   
  Great work on all the different tubes.  I'm guessing since you have tried various different families aside from the 6AK5, EF91&92 and 408A, have there been any ill effects on all those other tubes (amp blowing up, smoke, steam, opamps melting etc.)?
   
  Curious about all this since I own the MKIVSE and I+ (x2).
   
  Thanks!


----------



## gibosi

I finally manged to get some time to listen to my 1955 and 1958 Sylvanias. Initially, I was struck by just how different they looked. The plates and getters on these tubes are not at all similar.
   

   

  Moreover, I was also struck by how similar the 1958 Sylvanias looked compared to the 1956 Tung Sols. I assume this is not just a coincidence and there was deliberate borrowing/sharing of technology between these two companies. Furthermore, I wondered if the later Sylvanias might sound different than the earlier pair, and perhaps more similar to the Tung Sols.
   

   

  Well, the later Sylvanias do not sound like the Tung Sols. In fact, with my old rusty ears, I could not differentiate between the two pairs of Sylvanias. I found the Sylvanias to be warmer and more forward than the Tung Sols, with a tonal balance very similar to the GEs, but with just a little less warmth. The term that keeps coming to my mind is "smooth". The mid range seems detailed, effortless and smooth. Moreover, I kept noticing that vocals and instruments were clearly defined against a very quiet background, that "razor-sharp 3-D imaging" that some have ascribed to other Sylvania tubes.
   
  These Sylvanias have replaced the GE 8325As as my favorite 6AU6s. In fact, I just won an auction on eBay for three gold-pin 6136/6AU6 Sylvania for $15, shipped. Nice and cheap! And I sure hope they are as good as these old mil-spec tubes. 
   
  And I am now hoping others on this forum will pick up some Sylvanias. I am very curious to see if my old rusty ears are playing tricks on me, or if others will think these Sylvanias are as good, or better, than the GEs.


----------



## gibosi

Quote: 





heatfan12 said:


> Hi gibosi,
> 
> Great work on all the different tubes.  I'm guessing since you have tried various different families aside from the 6AK5, EF91&92 and 408A, have there been any ill effects on all those other tubes (amp blowing up, smoke, steam, opamps melting etc.)?
> 
> ...


 
   
  My amp has experienced absolutely no ill affects from running any of these tubes. Other than the thrill of being able to try out all these new and strange tubes, one could say it has been rather uneventful: no fireworks, no smoke and no foul odors, LOL.
   
  That said, it is imperative that you understand the pin outs of these tubes so that you can correctly set the various internal jumpers, and if necessary, strap pins together. Otherwise, you may well have some fireworks!
   
  For me, this has been more fun than I have had in a very long time, very rewarding and cheap!


----------



## Audiofanboy

Speaking of future fireworks, I think I found a few (at least one) types of 7-pin triodes that could work in our amps, with a few modding steps -a bit more complicated than for the 6AU6 since it would involve physically cutting some pins that would get in the way on the tube, and linking one pin back to the socket hole where one of the cut pins should have gone.
   
  I need to actually test this before recommending it, as I'm not 100% sure of myself on this one lol, and I have no idea if it sounds good too... But still, using triodes in our Single Ended Triode tube amps would make perfect sense and be a little cool in a way.
   
  Btw, same here, not a single problem after testing quite a *large* variety of tubes, including a number of non-natively compatible ones. Hell, I've been running my amp with 6AH6 tubes for two weeks; that tube has to be pinned modded to work and has 3 times the filament heater current of a 6AK5, so that should have challenged the amp badly enough, yet it runs better and cooler than with officially compatible EF91 tubes. Go figure...


----------



## gibosi

As long as we are sharing music, a friend recently sent me this link and it sounds pretty good on my LD:
   
https://www.youtube.com/watch?v=ou5uZjDNEko
   
  'Lost & Found' by Lianne La Havas


----------



## HeatFan12

Thanks guys...
	

	
	
		
		

		
			




   
  I'm using one LD I+ with the stock opamp (MC33078P) w/ EF91 & 92 tubes and one LD I+ with LT1364 with the 408A/6028 family.  My LD MKIV SE is set to the EF95 (6AK5, 5654, CV850) family.  I know it must be tedious but if you can compile a list of the uncommon tubes you guys are using and what family they pertain to, to make sure the jumpers are set correctly...
   
  Cheers!!!


----------



## gibosi

Quote: 





audiofanboy said:


> Speaking of future fireworks, I think I found a few (at least one) types of 7-pin triodes that could work in our amps, with a few modding steps -a bit more complicated than for the 6AU6 since it would involve physically cutting some pins that would get in the way on the tube, and linking one pin back to the socket hole where one of the cut pins should have gone.


 
   
  Oh boy! I need to dig out my Dremel tool so I can cut some pins! LOL


----------



## Audiofanboy

Young lads, and, well, less young lads, I just got some West German mil spec Valvo EF94 tubes in the mail, factory dated 1961 and 1968 and made by Mullard in the UK Blackburn factory, which was whole point. These look awesome and even better than the GE 8425A, and set my beautiful 8425A village on fire by being a grade or two above in terms of low level detail retrieval, transparency, and above all, soundstage. Widest I've seen since the EF91 and deepest I've heard, just realistic and large but not larger than nature. These are extremely detailed and transparent, while having that classic UK / Mullard sound that we've learned to love, and that I'd forgotten a little in the past weeks. If you loved your CV4010/M8100 and enjoy your current 8425A/6AU6A, but missed the detail and precision over a black background effect of you CV4015/M8161, then try these; they are most likely my new best tubes, somewhere between grade A+++ and A++++ (yes a grade or two better than the 8425A, and I don't give points easily).
   
  Incidentally, this makes me realize that I hadn't ever reported back on my *GE 6485 from 1978*, as I was waiting to test more of the 6AH6 range to reach a conclusion. I'd been using these tubes for the last week and a half, and had officially given it a full grade above the 8425A in my notes, so a *A+++ *grade, for the best holographic effect I'd ever heard -voices are so realistic that you can almost see the contour of the singer's face if you close your eyes- over a black background and the best detail retrieval I'd heard also. A bit on the analytical side though musical and very transparent, with the most detail highs ever, holographic mids -your can hear the "hollow" sound of drums and airy instruments- and a very good low end -though as powerful or tactile as I'd like, it's this tube's only fault with the limited soundstage width, which is more a matter of preference than quality. Of course, the Valvo (Mullard) EF94 is questioning all that now, having also pillaged my beautiful 6485 heaven with even better detail and transparency and UK mellowness and musicality, a great tactile low end and 3D big soundstage -that's all before burn-in so to be taken with a grain of salt.


----------



## gibosi

Quote: 





heatfan12 said:


> Thanks guys...
> 
> 
> 
> ...


 
   
  I suggest you go to page 50 in this forum and begin to read about what tubes people are using.... I believe I remember that several people have written about using 6EW6s, 6GX6s and 6CB6As in their LDs. These tubes require the EF91/92 jumpers.
   
  In my 1+, with an OPA2107, I am using primarily 6AU6s and 6AH6s. These tubes require that your LD be set up for 6AK5s *AND* pins 2 and 7 must be strapped in the socket. I suggest you go to page 59 of this forum to read more about how to do this.
   
  Happy tube rollling!


----------



## vic2vic

Quote: 





audiofanboy said:


> Young lads, and, well, less young lads, I just got some West German mil spec Valvo EF94 tubes in the mail, factory dated 1961 and 1968 and made by Mullard in the UK Blackburn factory, which was whole point. These look awesome and even better than the GE 8425A, and set my beautiful 8425A village on fire by being a grade or two above in terms of low level detail retrieval, transparency, and above all, soundstage.


 
   
  Super review !
  Does these EF94 require any specific pin strapping/bridging or they normally fits in the LD MK 7 pins socket ?


----------



## gibosi

Quote: 





vic2vic said:


> Super review !
> Does these EF94 require any specific pin strapping/bridging or they normally fits in the LD MK 7 pins socket ?


 
   
  EF94 is the European designation for 6AU6. So yes, exactly like the 8425As, you will need to set your LD to use 6AK5s and strap pins 2 and 7 in the socket.


----------



## gibosi

Quote: 





audiofanboy said:


> Incidentally, this makes me realize that I hadn't ever reported back on my *GE 6485 from 1978*, as I was waiting to test more of the 6AH6 range to reach a conclusion. I'd been using these tubes for the last week and a half, and had officially given it a full grade above the 8425A in my notes, so a *A+++ *grade, for the best holographic effect I'd ever heard -voices are so realistic that you can almost see the contour of the singer's face if you close your eyes- over a black background and the best detail retrieval I'd heard also. A bit on the analytical side though musical and very transparent, with the most detail highs ever, holographic mids -your can hear the "hollow" sound of drums and airy instruments- and a very good low end -though as powerful or tactile as I'd like, it's this tube's only fault with the limited soundstage width, which is more a matter of preference than quality. Of course, the Valvo (Mullard) EF94 is questioning all that now, having also pillaged my beautiful 6485 heaven with even better detail and transparency and UK mellowness and musicality, a great tactile low end and 3D big soundstage -that's all before burn-in so to be taken with a grain of salt.


 
   
  To refresh your memory, these are 1960s GE 6485s, the computer-grade version of the 6AH6:
   

   
  As you might remember from several pages back, there is a copper wire, clearly seen in the right tube, connecting the two plates.  Even though some might consider this copper wire a bit "ratty", it is obvious to me that the GE engineers understood very well that this "delicate" little wire was the key to providing "detailed highs and holographic mids". 
   
  To my ears, these are every bit as awesome as Audiofanboy says, and I encourage you to try these.
   
  So far, I have been able to find only one other brand of 6485. These are 1960s Tung Sols:
   

   
  Mine are still burning in and I haven't had a chance to do any carefully listening. However, there is no "delicate" wire here, but instead, very solid metal connectors. As a consequence, these tubes look great, but without that "delicate" wire.... perhaps we shouldn't expect too much?  

 And then there are the Sylvania 6AU6s and the Valvo EF94s....


----------



## zedmeco

I must say, this is really hotting up, I am almost tempted to dive in but I have a fear of doing some serious damage to my beloved amp, has anyone contacted David to see what he has to say about these new varieties? at the moment I am using these power tubes:
   http://www.ebay.co.uk/itm/261180804068?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649
  and these drivers:
   http://www.ebay.co.uk/itm/261157800735?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649
   
  running a set of sennheiser hd650's
   
  I wrote this track with these tubes, please have a listen and let me know how it sounds with your set up.
  https://soundcloud.com/zedmeco/grass-2012-mix
   
  thanks z


----------



## inphu510n

You guys are evil.
  I haven't even modded my existing 6AU6 tubes and you're off to some other incredible tubes.
   
  Looking up the 6485's on eBay, Svetlana 6J5P tubes pop up.
  I wonder if these are better than the 6J4P's that didn't fare so well?


----------



## Audiofanboy

Quote: 





inphu510n said:


> You guys are evil.
> I haven't even modded my existing 6AU6 tubes and you're off to some other incredible tubes.
> 
> Looking up the 6485's on eBay, Svetlana 6J5P tubes pop up.
> I wonder if these are better than the 6J4P's that didn't fare so well?


 

 I wouldn't go for any Russian type below an -EV or EB, as I've been consistently disappointed by plain Jane Russian tubes... Now, -IR, -ER and -DR versions are another story


----------



## mordy

Hi Gibosi,
   
  I am intrigued by your statement that a specific copper wire in a tube makes it sound better. It would be wonderful if you could look at a tube and say that this one has extended bass and treble and a huge 3D sound stage because of this and that. Unfortunately, I don't think that this is true.
   
  Take the different getters and getter flashes as an example. The shape of the getter doesn't matter. The color of the getter flash (silver, black or dark brown) doesn't matter. The size of the silver cap or the location (top, side) doesn't matter. What matters is that the getter flash produced a good, hard vacuum by eliminating the left over oxygen in the tube.
   
  What about the workmanship and quality of the parts inside the tube? Does it matter if the plate is black, grey or silver? Do the electrons behave better with a certain color coating the metal? Will exotic gold or silver grids make the tube sound better? Does the silk screened large or small shield on the Mullard tubes affect the sound? Does increased reliability and longevity make for a better sounding tube? Do gold plated pins make the tube sound better?
   
  The only conclusions I have come to is that military spec tubes have closer tolerances as measured and tested, and are thus "better" made. And tubes that are made more rugged and stronger last longer, but do not necessarily sound better. My retired engineer friend seems to remember that out of a certain production batch the top 25% of the tubes went to the military, the next 25% went to OEM manufacturers for use in the items they produced, and the remaining 50% went to the retail and replacement markets. There were large variances in the quality of the tubes produced in the same batch, and when you watch the film clips of tube production there is always footage of the huge crusher for the tubes that did not measure up.
   
  So we are left trusting our ears in experimenting with different tubes and trying to find the ones we like the best. When all the letters in the tube alphabet have been exhausted I am sure that a consensus will shake out about which tubes are in the top 10%. I am also a little unnerved by the fact that there are better alternatives to the 8425/6AU6 tubes that I am perfectly satisfied with. However, we have come to trust the judgment of the brave people on this forum that have threaded where no one went before. Look, this is progress, and there is nothing evil in that. And the fact that the tube universe has expanded with huge amounts of inexpensive tubes is also very gratifying.  Stay tuned for the latest discoveries!


----------



## rosgr63

Very nice statement Mordy, I enjoy reading your posts.
   
  Some military tubes, and I am talking about 6SN7's, had extra support posts, sometimes an extra mica, and a more ruggedised construction.
   
  Does that affect the sound?
  Yes the spacing of the elements does.
   
  I have found that copper post tubes sound more mellow, with tamer highs than the steel post versions of the same tube.
   
  Black plates are an indication of early production runs.
  Early production tubes are usually, but not always better sounding.
   
  I have found variations in sound between batches of the same tube.
   
  These statements reflect my own experiences with my equipment and a pair of well worn ears.
  I have no scientific evidence to support my observations.
   
  Happy Listening!


----------



## gibosi

Quote: 





mordy said:


> Hi Gibosi,
> 
> I am intrigued by your statement that a specific copper wire in a tube makes it sound better. It would be wonderful if you could look at a tube and say that this one has extended bass and treble and a huge 3D sound stage because of this and that. Unfortunately, I don't think that this is true.


 
   
  One of the problems with on-line forums, as opposed to face-to-face communication, is that humor is often lost... My comments regarding the "delicate" copper wire were intended to be humorous. Of course, one cannot determine the sound of a tube by its appearance. But I think it is rather funny that GE chose to use a plain piece of copper wire to connect the plates, making these tubes look more like prototypes than final production, belying their very high quality. Otherwise, I completely agree with your conclusions.
   
  Regarding the two 6485s...
   
  "Rusty Ears Impressions":  Their sound is quite different. The GEs have a very forward and upfront sound with great detail, "holographic" vocals and solid bass.  However, the bass doesn't have as much punch and slam as the Tung Sols. For sure, the first thing I noticed when I rolled in the Tung Sols was the bass, strong and powerful. Otherwise, the Tung Sols are more laid back than the GEs. The detail and clarity is there, but since it isn't as in your face as the GEs, it is not quite as noticeable.
   
  I will let others with better ears weigh in on which of these is better, but I think I could easily be happy with either as my daily drivers. They are different, but to my mind, both are quality tubes with great sound.
   
  And I have been practicing cutting off tube pins in anticipation of the next discovery!
   

   
  Using a Dremel with a small cutting disc, the pins are soft and easy to cut. However, if you get too close to the glass, grazing it, the tube cracks. Threw that tube away and got another... Also, as you can see, I nicked the adjacent pins... Have to see if I can find a way to protect them....


----------



## HeatFan12

You guys have completely taken tube rolling to a whole other level. Lol

Awesome. Keep up the great work.

Cheers!


Sent from my iPhone using Tapatalk


----------



## Audiofanboy

Quote: 





gibosi said:


> One of the problems with on-line forums, as opposed to face-to-face communication, is that humor is often lost... My comments regarding the "delicate" copper wire were intended to be humorous. Of course, one cannot determine the sound of a tube by its appearance. But I think it is rather funny that GE chose to use a plain piece of copper wire to connect the plates, making these tubes look more like prototypes than final production, belying their very high quality. Otherwise, I completely agree with your conclusions.
> 
> Regarding the two 6485s...
> 
> ...


 
   
  Hmm, so it might not be that easy to chop off pins apparently... Oddly, on my dead test tube (US made 8136), bending the pins back and forth until they snapped worked great and cut the pins off really close to the glass; the ideal case basically. But when I tried it on two random compatible-_ish_ triodes (UK made EC91 types, different brands, from a lot I bought a few months back), the glass broke right away when I bent the pins inwards... So, I guess the difficulty level will depend on the tube type and construction.
   
  I've been so busy the last two days that I haven't even been able to listen to my -already burnt-in- Valvo/Mullard EF94, or had time to de-oxidize the pins on my Tung Sol 6485, burn them in, and then test them... That plus another '61 pair of GE 6485 with the cheap-awesome construction I intend to test. So many tubes, so little time lol...
   
  Still, I have to say, this tube rolling has really made my amp into a different animal; the results I've consistently gotten with the last couple of tubes I tested -GE 8425A, GE 6485 and Valvo/Mullard EF94- are really surprising and would make going back to a 6AK5 tubes nearly impossible. And there are more audio types left to -adapt- and test, including those elusive 7-pin triodes that I'm just itching to -mutilate- and run on my amp!


----------



## gibosi

Quote: 





audiofanboy said:


> Still, I have to say, this tube rolling has really made my amp into a different animal; the results I've consistently gotten with the last couple of tubes I tested -GE 8425A, GE 6485 and Valvo/Mullard EF94- are really surprising and would make going back to a 6AK5 tubes nearly impossible. And there are more audio types left to -adapt- and test, including those elusive 7-pin triodes that I'm just itching to -mutilate- and run on my amp!


 
   
  I couldn't agree more. This evening, I put the 6485s and all the other tubes littering my desk away and rolled in my 1950s Sylvania 6AU6WAs, my current number one, and just leaned back and listened to music for a few hours. It was heaven. The tubes we are getting now are just so much better than any 6AK5 that it is almost impossible to consider going back...
   
  And tomorrow.. it is back to cutting pins!


----------



## GrindingThud

Pins be gone....cut them, don't grind or use a chin saw. They snip right off with flush cutters:




audiofanboy said:


> Hmm, so it might not be that easy to chop off pins apparently... Oddly, on my dead test tube (US made 8136), bending the pins back and forth until they snapped worked great and cut the pins off really close to the glass; the ideal case basically. But when I tried it on two random compatible-_ish_ triodes (UK made EC91 types, different brands, from a lot I bought a few months back), the glass broke right away when I bent the pins inwards... So, I guess the difficulty level will depend on the tube type and construction.
> 
> I've been so busy the last two days that I haven't even been able to listen to my -already burnt-in- Valvo/Mullard EF94, or had time to de-oxidize the pins on my Tung Sol 6485, burn them in, and then test them... That plus another '61 pair of GE 6485 with the cheap-awesome construction I intend to test. So many tubes, so little time lol...
> 
> Still, I have to say, this tube rolling has really made my amp into a different animal; the results I've consistently gotten with the last couple of tubes I tested -GE 8425A, GE 6485 and Valvo/Mullard EF94- are really surprising and would make going back to a 6AK5 tubes nearly impossible. And there are more audio types left to -adapt- and test, including those elusive 7-pin triodes that I'm just itching to -mutilate- and run on my amp!


----------



## gibosi

Quote: 





grindingthud said:


> Pins be gone....cut them, don't grind or use a chin saw. They snip right off with flush cutters:


 
   
  I should have realized that there is a tool to do this! Tomorrow I am going out to get one of these! Thanks!


----------



## mordy

I also thought of using a cutter for the pins, but Grinding Thud had already posted his suggestion when i wanted to write it. In any case, a small file might also help to take away the residue of the pin. It might also be helpful to use the rubber fingers previously mentioned here to hold the tube when working with it. (BTW, size XL is the right size for driver tubes).
   
   
  At this point in time I have three sets of the 6AU6 tubes - one pair of of 1964 RCAs, and two sets of Tektronix 6AU6/8425 tubes. One Tektronix set is from 1968 and made by GE and looks exactly like the ones that have been posted on this forum. Below is my other Tektronix set. It is marked 6AU6 with N.R. in yellow silk screen - the rest of the yellow silk screen
                                                                                                                                                                           8425
  markings are rubbed out. The plate is grey and completely surrounds the inside with a total of 6 small rectangular openings on the top and bottom of the plate. The top part of the the glass has Made in USA etched. Is it possible that this is a Sylvania tube?
   
  Can somebody decipher the Tektronix codes? 3565 = 35th week 1965?  157-073?


----------



## Acapella11

Audiofanboy, what do you think including As in your scoring to substitute some of the +? Like A++ < AA < AA+ < AA++ < AAA this might help to prevent A++++++++++++++ 
   
  And yes, all keep up the good work. I have got the GE 8425A  6AU6A tubes glowing in my LD MKIII. More on that later =)
   
  Best


----------



## gibosi

Quote: 





mordy said:


> At this point in time I have three sets of the 6AU6 tubes - one pair of of 1964 RCAs, and two sets of Tektronix 6AU6/8425 tubes. One Tektronix set is from 1968 and made by GE and looks exactly like the ones that have been posted on this forum. Below is my other Tektronix set. It is marked 6AU6 with N.R. in yellow silk screen - the rest of the yellow silk screen
> 8425
> markings are rubbed out. The plate is grey and completely surrounds the inside with a total of 6 small rectangular openings on the top and bottom of the plate. The top part of the the glass has Made in USA etched. Is it possible that this is a Sylvania tube?
> 
> Can somebody decipher the Tektronix codes? 3565 = 35th week 1965?  157-073?


 
   
  Can you post a picture? This would be most s helpful.


----------



## gibosi

A pair of Sylvania Gold Brand 6136/6AU6s arrived today:
   

   
  On the left is a 1958 Sylvania 6AU6WA, and of course, on the right is a 1960s Gold Brand 6136. They appear to be almost identical. Other than the gold pins, the only real difference I see is that 1958s have two additional small slots on the bottom of the plates and a square getter.
   
  Again, I doubt very much that "gold pins" will have any affect on the sound of these tubes. What I do believe is that by sticking gold pins on these and calling them Gold Brand 6136s, Sylvania is declaring these to be the best tubes they made, with the best materials, the best craftsmanship and the best measurements. While that does not necessarily translate into great sound, the fact that my 1955 and 1958 Sylvanias are the best sounding tubes I own makes me very hopeful that the Gold Brands will have the same great sound. Moreover, I got very lucky and paid only $5.00 a tube, shipped, so it was a no-brainer to give them a try. And just look at those sexy gold pins! LOL


----------



## gibosi

Picked these up today:
   

   
  If any of you have a hankering to cut and butcher tube pins, I can vouch for these. These are rated for 14 gauge, or as you can read on the handle, 1.6 mm, the largest of the three flush cutters the store had in stock. I do not know the wire gauge size of tube pins, but these worked perfectly fine. Since tube pins are made of a fairly soft metal alloy, even if they are larger than 14 gauge, it was still no problem to easily snip off pins.
   
  Onward!!  To the next discovery!!


----------



## mordy

I did post a picture which I can see on my posting. If you cannot see it, let me know and I will try to send it a different way.


----------



## gibosi

Mordy,
   
  I don't see a picture?????


----------



## mordy

Can you see this picture? Would appreciate if Gibosi or Audiofanboy could describe to me how you take those great closeups because I can't get the same quality, and I am sure that my camera has settings that would do it.


----------



## gibosi

Sorry, but I still don't see a picture.....
   
   
  I use a cell phone camera. I place my tubes on a glass-top table near a window with nice northern light. I use a small box to support the body of the phone at the correct height, to keep everything steady, with the camera lens hanging over the edge. And sometimes I use a little zoom. Nothing special...


----------



## inphu510n

So I finally got around to putting the 6AU6 tubes in.
  I have a few other sets but some '71 Sylvania JAN 6AU6WC tubes arrived today and I figured it was time. These things seems to be running pretty hot.
  I soldered stranded copper wire to the pins and I feel so, so much safer having done it that way. I initially tried the jumper method which of course is easier but I just didn't feel safe about it. What happens if the jumper doesn't properly connect?
   
  So far these tubes are quite good. I bought the Sylvanias because of the posts about their soundstage and separation. Indeed, their instrument separation is excellent. The resolution of each component is clearer and easier to pick out. I believe I'm noticing enhanced elements elsewhere because of the separation and stage. Things like transient noises are more apparent and psychoacoustic filters/transitions/modulations simply stand out more. I'm curious to see where the highs go after burn in as they don't seem quite as bright as the 6676s that I've been listening to for a while. The sub bass is great. Deep, defined and powerful. So far I think the mids are slightly more recessed than the 6676s.
  In some ways they seem a tad more analytical but that could be the slight mid recession. Something is a bit less warm so far.
  That's all I've got right now as they've been running for less than an hour. I'm sure they'll change up a bit in the next 20hrs or so.
  I'm definitely curious to see how the 8425 Tek tubes are going to sound.
   
  Overall these are fun tubes.
  I'm starting to wonder how much I'm being limited by my source material, DAC and headphones. Then again this is an LD MKII.
  This "hobby" sure becomes more addictive and expensive the deeper you go.


----------



## Acapella11

Gibosi, Please take a picture of the Northern Lights as well 
  
 Inphu510n, Generally, the headphone is what your system develops around. It has the most impact on sound quality and signature and sets amp requirements and also signature complementarity of amp and DAC. I suppose that for the HD-280 with 64 ohm and 102 db, at this headphone price point, the LD MKII is a very good option. However, if you consider a higher grade headphone, you will find only a limited selection of closed ones (Denon, Ultrasone, Audio Technica for example) and sound attenuation is even rarer. The best selection will be found between the open back headphones. Suggesting a higher end headphone, the Sennheiser HD650 pairs pretty well with the LD MKIII / IV. I have tested that too. Only that it is not my favourite sound signature  (quite relaxed). With respect to the DAC, on Head-fi, there is a lot of discussion usually about the amp, and lesser with respect to the DAC, but it needs to fit the overall system too, in terms of sound quality and signature. Some people say DAC first because nothing in the successive chain can improve the sound over how it is initially generated.
 With respect to the sound files, try to use FLACS and play using WASAPI, Foobar + WASPI plug in for example, or ASIO from your Computer, in order to bypass sound alterations caused by the operating system.


----------



## gibosi

Inphu510n, I am glad you are liking the Sylvanias. They are my current favorite of all the new tubes I have tried recently. I think you will find the 8425As to be equally excellent, but a bit more forward and upfront, which seems to be GE's "signature". And you may well like GE's signature better. After all, to build on Acapella11's comments, we tend to select headphones and tubes based on a "preferred" sound signature. Two people listening to the exact same system will likely have different reactions. One may love it and the other may find it just so-so... 
   
  And kudos to you for successfully soldering wires to tube pins! However, I wish to reassure you and others that if the "jumper doesn't properly connect", not much happens, actually. As I have been rolling a lot of different tubes recently, I have had the jumpers literally wear-out and break due to wire fatigue. If the connection is poor, I hear a great deal of noise, and I promptly shut the amp off, check the jumpers and then reinsert the tubes. If there is no connection, I hear nothing from one or both tubes. Again, I shut the amp off and check the jumpers. And on several occasions I have simply had to make new jumpers.
   
  Acappela11...  the next time I get up the Arctic Circle, I will definitely get some pictures of the Northern Lights! LOL 
   
  And to all you lurkers out there... These new tubes are just too good!!  Jump in! The water is fine!


----------



## Audiofanboy

Finally got a chance to test a few of my new tubes, before the next batch arrives lol.
   
  So, *Valvo EF94*, 1961 made by Mullard Blackburn, *A+++* grade just like my GE 6485 from 1978. These had the best amount of detail I'd heard before I tested the tube I'm currently burning in, mentioned below. You can actually hear Michael Jackson snapping his fingers on _Billie Jean_ all throughout the song -just an example lol. Anyway, like I'd said before great soundstage and separation, awesome detail and musicality, classic UK / Mullard sound mixed with the 6AU6 type sound, so great low-mids and bass, musical mids and detailed highs, with the same mellowness the 8425A had. But, and that but keeps these from  getting that extra +, I ultimately found the sound to be a little "weird" in mids and low-mids, with details standing out not so much out of an empty black background, but more out of a black space-like ether, just like what I remember from the Mullard CV4010/M8100. Not unpleasant as it makes a very cohesive ensemble with no absolute "air" between things and definitely feels less analytical than the GE 6485. So, yeah A+++, perfect if you never got over the UK EF95 types, like the CV4010, and like your music to be musical, detailed and a little dark; I think I'll go back to the analytical 6485 type for the time being, as I happen to like the absolute "air" between stuff and don't mind my soundstage to be just a little less large -still plenty large really.
   
  Speaking of analytical, enter the *Tung-Sol 6485*, made in the U.S. of A in 1970, O-getter and transparent glass. Basically the same as my GE 6485, with a better low end, more of those so-realistic-voices-you-wonder-what-you'd-been-listening-to-all-those-years -seriously- and apparently even better detail extraction -again the finger snaps on _Billie Jean_ but this time they're not just audible but right there above Michael nice and dry and snappy with a realistic reverb in the room, mesmerizing really- so those are off to a very good start in my books. I'll see how they change after burn-in, but these definitely won't get any less than a A+++, and might be my new favs! Still, just like the GEs, these are not mellow by any means unlike the 6AU6 tubes -more like fast fast fast and sharp- and that ultra-realistic detail comes at a price: highs that *could* get fatiguing but only if you push the volume too high. But those outrageous voices are very much worth it imo.
   
  I still have an older pair of GE 6485 from 1961 to test, just to see if I find a difference with the 1978s. Again, having tested a different pair of 6485 tubes, I would stick, when given the choice, to industrial types like the 8425A and 6485 over the military 6AU6Wx and 6AH6WA, as they seem way more responsive to a musical use.
   
  I should get some test 7-pin triodes to mutilate by mid-week, so expect some triode love in our LD amps in a few days -or a spectacular explosion, either way!


----------



## Audiofanboy

Quote: 





mordy said:


> Can you see this picture? Would appreciate if Gibosi or Audiofanboy could describe to me how you take those great closeups because I can't get the same quality, and I am sure that my camera has settings that would do it.


 
   
  I use a DSLR with a 55mm macro lens to get pictures of the tubes, I've also used an extension ring to take ultra close-up pics of the tube innards like the grids and such, but never put them here, as I didn't feel it had much use... I used to use a basic 50mm lens that wouldn't focus nearly as close (45 cm max from the subject instead of 20 cm with the macro) and crop the image to get a fake close-up, which I never really liked doing, intellectually. Tripod is an obvious requirement for those close-ups too, as they can get blurry really quick in low light.
   
  Quote: 





> Originally Posted by *inphu510n* /img/forum/go_quote.gif
> 
> I soldered stranded copper wire to the pins and I feel so, so much safer having done it that way. I initially tried the jumper method which of course is easier but I just didn't feel safe about it. What happens if the jumper doesn't properly connect?


 
   
  If the "mod" fails, and the cathode doesn't get connected to anything, you'll just get a normally loud Sssshhh sound, but nothing that's not supposed to be connected gets connected here, so it will never explodes or destroy the amp, it'll just make a weird noise and you'll know immediately that's something's off. It only happens if you plug in tubes in a non-straight way -from the pins' perspective, which usually aren't straight to begin with compared to the tube- or if you change tubes and don't re-straighten the mod wire before reinserting it and plugging in the new tubes. Otherwise, the wire can't move basically, since it's stuck between the tube pins and socket; so if it doesn't fail right away, it won't ever fail unless you move the tubes.


----------



## mordy

Hi All,
   
  I finally think I got the hang of how to take decent pictures and put them on the posts.
   
  Here is my present 6AU6 collection: First the RCA tubes from 1964 made for Bogen amplifiers. The plate has four circular holes in the middle. These sound good with strong and detailed bass. The treble has to be turned down to sound good.
  

   
   
  Next: The mystery Tektronix tubes that I need help in identifying. (My guess is that they are Sylvania tubes). These sound the best of the three - punchy bass and wide sound stage. All the yellow writing is visible. One tube has a R in a circle and the letters N.R. The left tube has just the R in the circle and the letter E and something under the label. The grey plate has 6 smallish rectangular holes - three on top and three on the bottom.
                                                                                                                                                

   
  Lastly, the GE 6AU6A/4825 tubes. Detailed and analytical, but not the same punch and sound stage as the other two sets (to my surprise after reading the reviews). Still, excellent tubes.

   
   
  Finally, a beautiful picture of northern lights.  A11 - how are the new 8425 tubes?


----------



## Acapella11

I have had a play with the *EF95 *jumper setting.
  
 *6EW6 *are used at *EF91/92 *settings, as far as we have been using them.
  
 I just removed my* 6AU6 *tubes and the socket bridge wire, and by accident just kept the EF95 setting. And... it sounds pretty good!
  
 If I understood this right, then what happens using 6EW6 with the EF95 setting is that g2 is strapped on the PCB to the anode as one electrode (pins 5 + 6). Then, the cathode stays lonesome (pin 2) and grid 1 (pin 1) is used as normally. Since grid 3 on pin 7 is not connected to the cathode on pin 2, it stays unused. But it works flawless and doesn't sound flabby. I am even tempted to say that it made the bass sound a bit harder hitting, less woolly than on the EF91/92 setting. I would need to confirm this properly but do try it =). There was no difference in terms of volume level.
 The take home message is that 6EW6 sounds great with the EF95 setting and that may reduce the number of jumper changes when switching between 6AU6 tubes (with socket bridge) and 6EW6 or even other EF95 tubes. In order to make sure that I am on the EF95 setting, as a final test, I used the Sylvania JAN 5654 tubes and enjoyed them actually with some good old 6N6P-I (no R) tubes 
	

	
	
		
		

		
		
	


	




.
  
  
 Mordy, I enjoy them but I got into this pin bridging experiments and forgot the time, so I will comment later on the GE8425s, I have also ordered a pair of Tung-Sol 6AH6... Thanks for the pic, I do like Northern Lights +


----------



## MIKELAP

Quote: 





acapella11 said:


> I have had a play with the *EF95 *jumper setting.
> 
> *6EW6 *are used at *EF91/92 *settings, as far as we have been using them.
> 
> ... 
  Actually i was listening to the 6ew6 and the 6cb6a on the EF95 setting and they sounded ok to me to but what would be the proper setting for these tubes  do you think either one is good ?


----------



## BobJS

-


----------



## Audiofanboy

Quote: 





mikelap said:


> Actually i was listening to the 6ew6 and the 6cb6a on the EF95 setting and they sounded ok to me to but what would be the proper setting for these tubes  do you think either one is good ?


 

 Hmm... Those type of pentodes could very well work OK triode-strapped with g3 -suppressor grid- just sitting there floatin' around, but most of the literature out there and basically all of Google highly recommends to have it strapped either to the cathode or to the anode along with g2. Vacuum tubes really aren't meant to have non-grounded things just sitting around in them accumulating potentials really... While g3 is probably the least critical active component in a pentode, it really isn't meant to just sit there unplugged -I wouldn't leave it floating and ungrounded personally, but that's just me.
   
  On a sadder note, one of my "new best tubes" just killed itself and went back to tube heaven -or hell, who knows?- so it's fast forward to the '61 GE 6485 for the time being, until I finally get some triodes in the mail to sabotage and test on my amp as driver tubes. A shame really, those Tung-Sol 6485 were really great now that I listen to the GE 6485 again... Maybe not a whole grade above, but actually not that far.


----------



## Acapella11

Quote: 





audiofanboy said:


> Hmm... Those type of pentodes could very well work OK triode-strapped with g3 -suppressor grid- just sitting there floatin' around, but most of the literature out there and basically all of Google highly recommends to have it strapped either to the cathode or to the anode along with g2. Vacuum tubes really aren't meant to have non-grounded things just sitting around in them accumulating potentials really... While g3 is probably the least critical active component in a pentode, it really isn't meant to just sit there unplugged -I wouldn't leave it floating and ungrounded personally, but that's just me.


 

 Hi Audiofanboy, why do you think, did the other attempts not work to strap g3 wither to anode or cathode? Shame the tube underwent self destruction. You never know with these old items...


----------



## gibosi

Quote: 





mordy said:


> Next: The mystery Tektronix tubes that I need help in identifying. (My guess is that they are Sylvania tubes). These sound the best of the three - punchy bass and wide sound stage. All the yellow writing is visible. One tube has a R in a circle and the letters N.R. The left tube has just the R in the circle and the letter E and something under the label. The grey plate has 6 smallish rectangular holes - three on top and three on the bottom.


 
   
  I have never seen any evidence that Sylvania branded 8425As exist. Furthermore, none of my Sylvanias have six holes (I have three pairs and they have either four (1960s) or eight holes (1950s)..... The only brand other than GE that I am aware of is Westinghouse:
   
  http://www.ebay.com/itm/NOS-Westinghouse-6AU6A-8425-Tube-With-its-Box-Tests-Good-/380617703447?pt=Vintage_Electronics_R2&hash=item589e954017
   
  Unfortunately the eBay picture isn't all that great...  However, Westinghouse did use yellow ink... But interestingly, the printing on the box is "8425" and not "8425A"... Anyway, this is my best guess....


----------



## gibosi

Quote: 





acapella11 said:


> Since I was in experimenting mood, I also tried other grid straps, connecting pin 2 (cathode) with pin 7 (g3) since this is the setting used in EF95 tubes. All lit up fine, no crackling or anything but no sound either. 
   
  I used the 6EW6s strapped the same way as the 6AU6s, that is, pin 2 and pin 7, and it worked flawlessly. I wanted to directly compare the 6EW6 and the 6AU6, and I am surprised it didn't work for you... very strange.....


----------



## mordy

Hi Gibosi,
   
  I think that you are right. Here is a Westinghouse tube that looks like what I have. (Looked at a bunch of Sylvania tubes with yellow print but nothing matched).
   
  Thanks,
   
   
  http://www.ebay.com/itm/Vintage-Radio-TV-Vacuum-Electron-Tube-Westinghouse-6AU6-/400460245369?pt=Vintage_Electronics_R2&hash=item5d3d4a6979


----------



## gibosi

Quote: 





mordy said:


> I think that you are right. Here is a Westinghouse tube that looks like what I have. (Looked at a bunch of Sylvania tubes with yellow print but nothing matched).


 
   
  Glad this little mystery has been solved. 
   
  And since you tell us that the Westinghouse 8425s are even better than the GEs, I, for one, would love to get a pair. While I have been able to find a couple of regular Westinghouse 6AU6s, I can't find even a mention of Tektronix 8425s.. You are one lucky guy! LOL
   
  But for sure, now that I know these exist, I will definitely be keeping an eye out for a pair.


----------



## mordy

Here is my source. Ask the seller if he has more of the Westinghouse tubes - seems to be a friendly guy.
   
   
  http://www.ebay.com/itm/321095368010?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649


----------



## Audiofanboy

Quote: 





acapella11 said:


> Hi Audiofanboy, why do you think, did the other attempts not work to strap g3 wither to anode or cathode? Shame the tube underwent self destruction. You never know with these old items...


 
   
  That's actually pretty weird that the "manual" strapping attempts didn't work properly. My guess is that this is sensitive stuff, that requires very stable connections -strapping- to work without issues; but it definitely should have worked.


----------



## gibosi

Quote: 





mordy said:


> Here is my source. Ask the seller if he has more of the Westinghouse tubes - seems to be a friendly guy.
> 
> 
> http://www.ebay.com/itm/321095368010?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649


 
   
  Thanks for the link. I now have a pair of Tek labeled Westinghouse 8524s coming my way. And yes, he is a friendly guy. I have purchased from him before.
   
  And he tells me that he has only one more pair of these:
   
  "I have one more set. The stickers have fallen off the last set but they are a checked pair you can tell that by the glue marks. If you know someone that wants a pair these would be 10 bucks."
   

   

  And this is with free shipping with the US.
   
  Edit: I tried to save and include the picture he included in his message, but evidently you can see it enlarged only within the eBay messaging system. I can vouch for the fact that you can definitely see the glue marks where there were labels at one time.


----------



## Acapella11

Quote: 





gibosi said:


> I used the 6EW6s strapped the same way as the 6AU6s, that is, pin 2 and pin 7, and it worked flawlessly. I wanted to directly compare the 6EW6 and the 6AU6, and I am surprised it didn't work for you... very strange.....


 
 
 OK, I got confused with the mirror of the tube pin layout on the socket, and actually did not connect the pins intended 
	

	
	
		
		

		
			





 (oh no...). This explains the unusual behavior... No harm was done to either tubes nor amp, though, lol. I have edited my above post. Yes, if you keep the socket bridge for the 6EW6 tubes in EF95 setting, you strap g3 to the cathode, which is fair enough and an alternative to the anode strap done by the jumper in EF91/92 setting. The other thing, I found is that g1 on pin1 seems to stay lonesome during any operation. Sorry for the confusion.


----------



## mordy

I wanted to try a pair of Tung Sol 6676/6CB6A. As far as I can remember these need the EF92 setting on the jumpers. Instead, I left the jumpers on the EF95 setting and strapped pins 6 and 7. All I got was hum. Am I doing something (or a lot of things) wrong?


----------



## gibosi

Quote: 





mordy said:


> I wanted to try a pair of Tung Sol 6676/6CB6A. As far as I can remember these need the EF92 setting on the jumpers. Instead, I left the jumpers on the EF95 setting and strapped pins 6 and 7. All I got was hum. Am I doing something (or a lot of things) wrong?


 
   
  I have never tried strapping pins 6 and 7 using the EF95 settings... But yes, it seems to me that it should work...
   
  However, I have a run 6GX6. 6EW6 and 6GM6 using the EF95 settings, and strapping pins 2 and 7, exactly the same for 6AU6, and the 6CB6As can be treated the same way. The suppressor grid, S3, can be strapped to the anode (using the EF92 settings) or to the cathode (using the EF95 settings and strapping pins 2 and 7). Theoretically, it shouldn't make any difference. So I would suggest that you use the same settings and strappings as you do for the 6AU6 too keep things just a little simpler.


----------



## Audiofanboy

Quote: 





mordy said:


> I wanted to try a pair of Tung Sol 6676/6CB6A. As far as I can remember these need the EF92 setting on the jumpers. Instead, I left the jumpers on the EF95 setting and strapped pins 6 and 7. All I got was hum. Am I doing something (or a lot of things) wrong?


 
   
  Would it possible that, like Acapella, you strapped the wrong -mirrored- pins, and ended up strapping pins 1 and 2 on the socket (grid + cathode), which I wouldn't be surprised would hum. Manually strapping pins 6 and 7 -so 5+6+7 really- should obviously do the exact same thing as using the EF92 jumpers, so something's wrong here.
   
  Quote: 





gibosi said:


> I have never tried strapping pins 6 and 7 using the EF95 settings... But yes, it seems to me that it should work...
> 
> However, I have a run 6GX6. 6EW6 and 6GM6 using the EF95 settings, and strapping pins 2 and 7, exactly the same for 6AU6, and the 6CB6As can be treated the same way. The suppressor grid, S3, can be strapped to the anode (using the EF92 settings) or to the cathode (using the EF95 settings and strapping pins 2 and 7). Theoretically, it shouldn't make any difference. So I would suggest that you use the same settings and strappings as you do for the 6AU6 too keep things just a little simpler.


 
   
  For some reason, I'd tend to keep strapping g3 to the cathode (so pins 2+7 or 7+2 depending on tube type) even on non-6AU6 tubes that could work with the EF92 jumper, as it sounds good and seem intellectually reasonable (g3 is often hardwired to the cathode in a lot of pentodes like the EF95). Like gibosi, I'd just keep it nice and simple.
   
  Unlike this new tube type and new mod.
   
  Good news, you can use triodes as driver tubes on the LD amps, and even better news, they sound great! I've just set up for burn-in a random pair of French Thomson-CSF Miniatron 6J4S -originally bought as test tubes though they're supposedly mil-spec and made for security applications- and I am quite surprised by what I hear. Even more detail than my 6485 tubes, both GE and even the Tung-Sol, definitely better low end -the 6485 type only fault- and more forward I would say; also great sense of space and "realism" with gorgeous vocals. Maybe not better than my 6485 types and Valvo/Mullard EF94 but definitely a fourth A+++ tube. And that's only a starting point for this tube type.
   
  I'm not that surprised that tube type would work well though. I had originally picked it out because of its very nice specs with mu/gain of 50 (EF95=20, 6AU6=36, EF91=70, amp heats up in that order btw) and transconductance/gm of 12 or 12000 (EF95=4000-4500, 6AU6=5000-5500, 6485/6AH6=11000), and of course a 400 mA heater, so definitely considered a strong signal tube. I still can't figure out if it's mu or gm I need to power my -orthos- headphone properly (you'd want higher mu for dynamic headphones like Senns, voltage is good), but this tube type has both high mu and gm, so I figured it couldn't be bad really.
   
  Now, the catch. It's definitely not even remotely natively compatible. Pins 5 and 6 (the two extra grid 1 pins out of three, meant to be grounded originally) have to be snapped/cut/amputated off. I tried the first option, and it worked on two tubes snapping the pins cleanly and leaving no extra metal sticking out -though chipping off of piece of glass too, not that it matters. The third tube -actually the second one I tried- exploded upon bending the second pin back and forth, cleanly splitting the glass all around the base. So cleanly in fact that I was able to just take the glass "cylinder" off and now have the naked tube internal sitting on the base and apparent; I might take a picture of it since it looks great.
   
  And you need to strap pin 7 (anode) to pins 5 or 6. I would have done it at the socket level, but there are no pins 5 and 6 to hold down a wire mod. So, until someone comes up with a better idea, you have to use the EF92 jumper setting -meaning the anode or output signal goes through the dirty crappy jumper to get to the power tubes, which I can't say I like intellectually...
   
  I'll give a better review of these after burn-in.


----------



## gibosi

A pair of Motorola 6J4s:
   

   
  I am not sure if Motorola actually made their own tubes or if these are simply rebranded...  Even so, first impressions, these sounded very good. However, one of them turned out to be very microphonic and was adding all kinds of strange sounds to the music. So I have put them aside and ordered a pair of Sylvania JAN 8532W, which are a higher grade of 6J4. You also might want to look for a pair of CV5311.
   
  After reading Audiofanboy's remarks about snapping pins off, I really do encourage any of you who want to try these tubes get a pair of flush cutters. It leaves a small stub, which is probably nothing to worry about, but I covered them with some electrical tape just to be extra safe:
   

   
  Instead of using this ugly tape, you could use paint or varnish. And in fact, I suggest going to a drug store and getting some finger nail polish. This not only provides protection, but it will allow you to "personalize" your tubes, from soft pastels to the garish, you can make them truly yours! lol 
   
  And we are off to the strange new world of "mutilated triodes"!


----------



## Audiofanboy

Quote: 





gibosi said:


> A pair of Motorola 6J4s:
> 
> 
> 
> ...


 
   
  I did the same and immediately ordered some nice Sylvanias JAN 8532W, which should be the highest possible grade for this tube type.
   
  For once, this type is going to be pretty quick to test, as there are only like 3 or 4 quality versions of these available on fleebay: the ones gibosi and I just ordered (only Sylvania I think, which, having that 4-digit number, should be a special quality type, possibly better than the reliable US mil-spec version), the equivalent mil-spec US 6J4WA (only RCA and Sylvania apparently), the UK CV5311 -available from only one seller anyway- and those French ones I bought which are clearly premium quality tubes -they looked great before I mutilated them, I bought the 6J4S but there's also 6J4WA from that same brand; I do recommend them, if only for the fact that the only seller sells them by lots of 8 or 10, so you afford to break one or two. I'd stay away from any of the Russian tubes, which btw are often not real 6J4 but some other EF94-ish tube, so different; there seems to be a confusion all around google about that.
   
  I didn't hesitate to break off the pins on these French tubes, because I had 10 of them and didn't care, but I'm obviously going to have to use a softer way for more expensive pairs where I have no spares...


----------



## gibosi

Quote: 





audiofanboy said:


> - and those French ones I bought which are clearly premium quality tubes -they looked great before I mutilated them, I bought the 6J4S but there's also 6J4WA from that same brand; I do recommend them, if only for the fact that the only seller sells them by lots of 8 or 10, so you afford to break one or two.


 
   
  For some reason, a search for 6J4S on eBay in the US does not find these tubes. I had to go to eBay in France to find them.
   
  http://cgi.ebay.fr/ws/eBayISAPI.dll?ViewItem&item=111050587891&fromMakeTrack=true&ssPageName=VIP:watchlinkfr#ht_500wt_1136
   
  I then logged into eBay France and added them to my watch list, and now they are showing on my US eBay watch list, should I decide to order them later.


----------



## MIKELAP

Quote: 





mordy said:


> I wanted to try a pair of Tung Sol 6676/6CB6A. As far as I can remember these need the EF92 setting on the jumpers. Instead, I left the jumpers on the EF95 setting and strapped pins 6 and 7. All I got was hum. Am I doing something (or a lot of things) wrong?


 
  Hey mordy just tried the 6cb6a on EF95 like the last time i listen to them and they sound good on that setting  but they should be used on the EF92 you say is it dangerous for the amp on the EF95 setting .


----------



## gibosi

Quote: 





mikelap said:


> Hey mordy just tried the 6cb6a on EF95 like the last time i listen to them and they sound good on that setting  but they should be used on the EF92 you say is it dangerous for the amp on the EF95 setting .


 
  If you strap pins 2 and 7, it is not at all dangerous to use the 6cb6a in the EF95 setting. Treat them exactly as you would the 6au6, and everything will be good.


----------



## mordy

DISCLAIMER: DO NOT USE THE DIAGRAM BELOW!
   
  I used this diagram as a model, and I now realize that IT IS INCORRECT for our purposes and it really should be a mirror image with everything reversed. In any case I put in the Tung Sol 6CB6/6676 using the 2-7 strapping and everything works fine as suggested.
  These tubes have the Tung Sol trademark punchy bass and extended highs and I need to tone down the treble a little. In comparison to the Westinghouse Tektronix they are quite good, but the Westinghouse Tektronix 6AU6/4825 have better control of the bass and the highs and are still tops by me (for the time being), and in comparison the bass of the Tung Sol tubes is slightly boomy.
  My old favorite TS 6AJ5 sounds a little tame in comparison with the W Tex with a lack of energy in the bass and treble compared to the mighty 6AU6/4825 tubes. However, the mid range is sweeter.
  We shall be looking for a tube that has everything - I feel that we are getting closer....
   
  AFB - you got it all right -Thanks for the help!


----------



## mordy

Oops - the picture disappeared again - just as well as it was confusing and the pinout was marked in the reverse.


----------



## mordy

Hi Gibosi,
   
  Agree that it does not seem to be any danger in using the 6CB6A/6676 tubes with the 2-7 strap with the EF95 setting.
  My tubes have been on a couple of hours now and everything seems normal.
  These tubes are the "poster child" for my vacuum tubes because they have the brightest heater of them all with a beautiful bright orange glow. Just changed my picture (Avatar?). Hope this one works out - I don't seem to do well pictures on the posts....


----------



## mordy

Here is a close up:
  Compare the 6676 glow to the glow of the 6N6P gold grid in the back.


----------



## Acapella11

Quote: 





mordy said:


> DISCLAIMER: DO NOT USE THE DIAGRAM BELOW!
> 
> I used this diagram as a model, and I now realize that IT IS INCORRECT for our purposes and it really should be a mirror image with everything reversed. In any case I put in the Tung Sol 6CB6/6676 using the 2-7 strapping and everything works fine as suggested.


 
  Mordy, I read through the data sheets and publications and was really happy about what I learned and then I did the mirrored pin mistake, lol. You are not alone mate =)
   
  Audiofanboy and gibosi, good to see triodes coming through as well. The MKIII develops itself to a never ending tube rolling juke box =) We should hire someone (David?) to design an even upgraded MKIII as already suggested by Mordy, for more dip switches instead of jumpers and allow even higher output power, so we can enjoy higher powered tubes even better =) LD MKIV TE or AFB .


----------



## gibosi

Quote: 





mordy said:


> Here is a close up:
> Compare the 6676 glow to the glow of the 6N6P gold grid in the back.


 
   
  The brightest tube I have is also a Tung Sol, the 6485/6AH6, which has a very open cage and a clear glass envelope:


----------



## mordy

Hi Gibosi and Audiofanboy,
   
  Took the plunge and made two little jumpers for strapping pins 6&7 on the EF95 setting. Put in a pair of Mullard large shield EF92 tubes. Everything works fine. So if you don't want to change the jumpers this method definitively works well.
   
  The Mullard boxes are printed with the price 13/- which I think means 13 Shilling. I assume the tubes are from the 60's (the Shilling was abandoned in 1968).
   
  Anybody knows how much these tubes would be today in US dollars? (I plan to sell these tubes and need a price point to start with)
	

	
	
		
		

		
			




   
  The picture of the TS tube is very beautiful!


----------



## gibosi

Quote: 





acapella11 said:


> Mordy, I read through the data sheets and publications and was really happy about what I learned and then I did the mirrored pin mistake, lol. You are not alone mate =)
> 
> Audiofanboy and gibosi, good to see triodes coming through as well.


 
   
  Glad to hear that you've got your pins "straight" now. When you start cutting pins off those precious new triodes you ordered, you certainly don't want to make a mistake!


----------



## gibosi

Quote: 





mordy said:


> Put in a pair of Mullard large shield EF92 tubes......The Mullard boxes are printed with the price 13/- which I think means 13 Shilling. I assume the tubes are from the 60's (the Shilling was abandoned in 1968).
> Anybody knows how much these tubes would be today in US dollars? (I plan to sell these tubes and need a price point to start with)


 
   
  For what it is worth, some time ago, I purchased a set of 1970s CV4015s for about $26 shipped from the UK. One of the tubes is unbranded with CV4015 stamped on one side and the other tube is stamped 'Phillips Miniwatt' on one side but doesn't have CV4015 on the back.
   
  As yours are a Mullard-branded pair with the large shields, I would think you could ask for more than that....


----------



## gibosi

A sleeve of five Sylvania 6J4/8532Ws arrived today. They are newer than I would prefer, 1977, but at least the first two I grabbed sound very good.
   
  BM (Before Mutilation):
   

   
  These look just the Motorolas I received last week, with the exception of the thicker mica.
   
  The flush cutters make cutting tube pins very easy and work very well:
   

   
  These stubs are pretty small, but even so, I covered them with electrical tape just to be safe. (And no, I haven't made it to the drug store to get some finger-nail polish yet. lol)
   
  Again, all my pictures are all taken with a cell phone (Samsung Galaxy Nexus). However, in order to take this close-up of the stubs, I used a very handy little attachment, a rubber band with a macro lens.
   

   
  They are now burning in, but so far, I am really liking what I hear. Great bass, great vocals and great highs.... I just might like these more than my Sylvania 6AU6s....


----------



## mordy

Which pins are cut off - 2 and 3?


----------



## Audiofanboy

Quote: 





mordy said:


> Which pins are cut off - 2 and 3?


 
   
  Nope, 5 & 6. Damn that mirror effect!
   
  Edit: Nice cutting, I have to admit.


----------



## mordy

Do these tubes also require the EF95 setting with pins 2&7 strapped?
   
  Regarding the Sylvania 1977 tubes: When looking for tubes for my MKIII I came to the conclusion that 1970's Sylvania tubes were still high quality, but GE tubes declined in quality in the 70's and later.


----------



## gibosi

*Tube Pin Numbering 101*
   

   
  Hold the tube in your hand, upside down, with the pins facing up. Orient the widest gap between the pins to be closest to your body. Now compare the tube in your hand to the basing diagram above. The pin just to the left of the gap is pin 1. Count clockwise ending at the pin just to the right of the gap, pin 7.
   
*The 6J4 triode*
   
  The diagram above is for the 6J4, the triode that AFB and I are currently trialing.
   
  The list of terminal connections, to the left of the basing diagram, indicates that the grid is tied to pins 1, 5 and 6. Whatever the reasons for having three pins tied to the grid, for our purposes, only one pin is required, and normally that is pin 1. Therefore the grid connections on pins 5 and 6 are not necessary and can be eliminated. Also note that the plate is tied to pin 7. However, our LDs expect the plate to be connected to pin 5, so we need to get the 6J4s plate on pin 7 connected to pin 5. But it just so happens that the purpose of the EF92 jumper is to connect pins 5 and 7.
   
  Therefore, we sever pins 5 and 6 to eliminate the superfluous grid connections, and then we set our LDs up in the EF92 configuration to get the plate connected properly. Once done, everything is good. 
   
  Edit: No little wires connecting pins in the socket are required to use this tube. So it couldn't be simpler. EF92 and sever two pins!


----------



## mordy

*Tubes and CRT's*
 *EIA co* Amperex (USA)  111 Bendix 125 DuMont 158 Eimac (Eitel-McCullough, Inc) 162 Electronic Tube Corp 169 General Electric Co (USA) 188 Hytron (CBS-Hytron) 210 Machlett 231 RCA (Radio Corp of America) 274 Raytheon 280 Superior Tube Co 310 Sylvania (Hygrade Sylvania Corp) 312 Tung-Sol 322 United Electronics 323 Western Electric 336 Westinghouse 337 Zenith Radio Corp (CRT's) 343 Nortn American Philips Corp 423 Taylor (aka Cetron-Taylor) 713 Lewis & Kaufman 738 National Electronics (also Cetron) 749 Penta Laboratories 771 Vacuum Tube Products 781 Varian Associates 809 Litton Industries 879 Electrons, Inc 935
   
  Dear AFB,
   
  I was reading about your post about the Motorola 6J4 tubes where you wondered if Motorola made their own tubes or if these were rebranded. As can clearly be seen on the picture of the Motorola tube there is a number 274 printed on the tube, which identifies them as made by RCA - just check the enclosed chart.


----------



## Audiofanboy

Quote: 





mordy said:


> Do these tubes also require the EF95 setting with pins 2&7 strapped?
> 
> Regarding the Sylvania 1977 tubes: When looking for tubes for my MKIII I came to the conclusion that 1970's Sylvania tubes were still high quality, but GE tubes declined in quality in the 70's and later.


 
   
  Actually, some specific GE tubes made in the late 70s still seem to sound good -my GE 6485 made and packed in 1978 definitely do- so for special non-mil-spec but industrial-computer rated tubes, you should still be fine diving into the not-so-old GE tube stocks. On the other hand, for anything consumer-grade or military, I would stay away from 70 and 80s GE tubes, as there is a clear decline (probably from when GE made those last "lifetime supply" batches for the US gov't and army).
   
  As gibosi said, the easiest way to use 6J4/8532 tubes is to use the EF92 jumper setting -and to chop off pins 5+6. I'm still not very comfortable using the jumper to actually conduct the output amplified signal from pin 7 to pins 5/6 -and I hate changing jumpers- but I just can't see an easy way to strap pins 5 and 7 at the socket level, not solidly at least.


----------



## Acapella11

As long as staying on the tube side of things, the* pin numbering* is straight forward I suppose because it is exactly as on the data sheets. Only, when looking at the socket, I was so much tempted by the pin north of the gap to be # 1, lol, although it obviously must be the one south of the larger gap! Hence, for the tube side, I suggest, just use one of the data sheets, Gibosi's on this page for example. Then for the socket side, a simple reminder is "Seven Up" 
   
  Tubes: Today, I received the 6AH6 type *Tung-Sol 6485* tubes. I have just put them in, and they sound really good. One word: Stage! The stage is wide, feels very nice. Slightly wet, as in nice reverb. That enhances the stage feeling too. Transparent, that's what they are, *wow*. Great open sound. The bass is very punchy. It is almost, you think it's not there, that's how clean they sound, until, when it kicks in - it kicks the shiit out ouf you. I wouldn't mind a little more weight in the bass section but they still seem pretty well balanced across the spectrum, which I find quite important. They sound neutral too, surely in the CV4015 signature direction. More on that later but they could become my go to tubes 
	

	
	
		
		

		
			





 Good stuff, and so far, (even) more impressive than the GE 8425 (6AU6 type). Tube code is 3227106-3, which I interpret as Tung Sol (thanks Mordy  ) and 6th week of 1971.
  Best
   
  PS: Don't want to pester you with pics but I can take one if you are interested.


----------



## mordy

Pictures are always welcome.
   
  I must say that I find it a little hard to keep up with you guys and all the new stuff you are trying, and I also find it difficult to keep up with the alphabet soup and numbers of all the different tubes.
   
  First, I would like to hear a consensus and ranking about which tubes are the best sounding (as AFB did in the past). Then, after each tube, a line with the settings required. An example would be like this:
   
  1)Super Duper 6ABCDEFGWA EF95 setting with pins 2&7 strapped
  2)Electron Fabulosi 3995 EF92 setting with pins 5&6 snipped off
  3)Unobtanium 4892i EF91 setting with liquid cooling
   
  The tube names are all a joke, of course, but it would be nice to have a little chart to go by. I am still working on the mirror image pin numbering....Let's see, if I look down on the empty socket of the LD driver tube, the top left is #7, but if I look at a tube with the pins facing me, and the bigger gap on the left, the bottom left is #7.
  Did I get it right?


----------



## Audiofanboy

Quote: 





acapella11 said:


> As long as staying on the tube side of things, the* pin numbering* is straight forward I suppose because it is exactly as on the data sheets. Only, when looking at the socket, I was so much tempted by the pin north of the gap to be # 1, lol, although it obviously must be the one south of the larger gap! Hence, for the tube side, I suggest, just use one of the data sheets, Gibosi's on this page for example. Then for the socket side, a simple reminder is "Seven Up"
> 
> Tubes: Today, I received the 6AH6 type *Tung-Sol 6485* tubes. I have just put them in, and they sound really good. One word: Stage! The stage is wide, feels very nice. Slightly wet, as in nice reverb. That enhances the stage feeling too. Transparent, that's what they are, *wow*. Great open sound. The bass is very punchy. It is almost, you think it's not there, that's how clean they sound, until, when it kicks in - it kicks the shiit out ouf you. I wouldn't mind a little more weight in the bass section but they still seem pretty well balanced across the spectrum, which I find quite important. They sound neutral too, surely in the CV4015 signature direction. More on that later but they could become my go to tubes
> 
> ...


 
   
  Aaah! Glad to see a third person saying the Tung-Sol 6485 are great tubes, and potentially the best they have. One of mine died quickly after burning in, but I should get my -free- replacements by the end of the week or early next week, and be able to report back on these more thoroughly.
   
  Right now, in terms of detail their only true rival is the French 6J4S tubes I have, and to a smaller extent the Valvo/Mullard EF94 and GE 6485; definitely a world above the GE 8425A. These have punchier bass that goes down low but I did like how the bass on the 6485 type -its only "default" imo- is unobtrusive and just there and nice behind the details; though I wouldn't mind a bit more punch/power in the low end, which might in turn hide some details.
   
  Tradeoffs really... Musical, mellow and a little bassy or ultra-detailed and balanced -read occasionally treble-oriented- with a great stage.
   
  Just one question Acapella, your TS 6485 are transparent and have an O-getter right, the latest construction? Just curious if there's an older construction out there too, like for the GE.


----------



## Audiofanboy

Quote: 





mordy said:


> Pictures are always welcome.
> 
> I must say that I find it a little hard to keep up with you guys and all the new stuff you are trying, and I also find it difficult to keep up with the alphabet soup and numbers of all the different tubes.
> 
> ...


 
   
  I think I had a picture of the sockets a few pages back (probably 15 by now, but it's on my profile I think) with showed pins 2 & 7 socket strapped. I still use that picture as an absolute reference when I have a doubt, so I don't make a mistake. Once you've strapped a few tubes at the socket level, and snapped some pins of another couple of tubes, you'll start to know pretty instinctively what you're doing. When in doubt, I also often check to see which pins go to the heater (usually pins 3 & 4, at least on all the "compatible" tubes I've tried) in a tube -which you can usually pretty easily see- that way i can know for sure what pins are where from there.
   
  I could try to make a quick list, but I just don't have that much time and may not be able to update it often, which in turn could be risky for people using it that haven't been around long enough... But right now, there are only so many new non-native types, it is still easy:
   
  - 6CB6 / 6CJ6 / 6676 -> EF92 jumper (or strap pins 2 & 7 at the socket level (wire mod))
  - 6DK6 / 8136 -> EF92 jumper (or strap pins 2 & 7 at the socket level (wire mod))
  - 6GM6 -> EF92 jumper (or strap pins 2 & 7 at the socket level (wire mod))
  - 6EW6 -> EF92 jumper (or strap pins 2 & 7 at the socket level (wire mod))
  - 6GY6 / 6GX6 - EF92 jumper (or strap pins 2 & 7 at the socket level (wire mod))
  - 6AG5(WA) / 6J3P(-E) / 6BC5 / 6CE5 / EF96 / 6186 -> EF95 jumper
  - 6AU6(A/WA/WB/WC) / 6136 / 8425A / EF94 -> EF95 jumper + strap pins 2 & 7 at the socket level (wire mod)
  - 6AH6(WA) / 6485 -> EF95 jumper + strap pins 2 & 7 at the socket level (wire mod)
  - 6J4 / 8532(W) -> EF92 jumper + snap off pins 5 & 6 (snap & tape (?) mod -do make sure you tape over the leftover stubs so you don't electrocute yourself or make your amp explode, think of the children)
   
  Don't hesitate to copy and paste this and improve it, I just threw this together as a temporary list... I still thoroughly recommend to go back 10-30 pages and read over whole sections when in doubt, as everything is written there quite precisely and without that much spam between messages, and it's still the best way to avoid mistakes. Like someone mentioned a while back, we've succeeded in keeping this thread polite and clean, and therefore fairly convenient to read over lol.
   
  Edit: With little doubt, my current tube order is (I'll limit myself to the top A+++ tubes): Tung-Sol 6485, GE 6485, Valvo/Mullard EF94, "the brand new 6J4 triodes" (to be confirmed obviously, but my French 6J4S and the Sylvania 8532W gibosi tested are an extremely good start)
   
  Quoting and editing myself from page 60 for the rest:
  1 (A++) - GE 8425A/6AU6A (check with gibosi for the other best 6AU6 like the Sylvanias which I haven't tested)
  2 (A+) - GEC CV4014
  3 (A or A+ depending on headphone impedance) - Mullard CV4015
  4 (A) - GE 6GM6, 6EW6, 6GX6/6GY6
  5 (A- to B+) - GE 8136, 6CB6A, Mullard CV4014/M8083 (Mitcham), Tung Sol 6AJ5, Mullard CV4010/M8100, Voskhod 6J1P-EV (Gold grids), Mullard CV5377 (Mitcham), Mullard CV4014 (Whyteleafe)
  6 (B to C+) - Brimar CV4014, Mullard CV138/6AM6, Voskhod 6J1P-EV (Non-gold grids), Brimar CV138, Mullard CV850 (Whyteleafe), Tung Sol 6AK5 (side getter, early shape, 1943), GE JAN 5654W
   
  That's about all I can give you at this point, which should sum up quite a bit of information I think. Again, the detailed reviews and pics are all in the last few dozen pages with the right keywords to search for (even I keep getting lost here looking for information we posted like... 3 weeks ago...).
   
  Edit 2: use tape with 6J4 pins you snap off
   
  Edit 3: all non-LD-compliant (non EF92/91) tubes that work with the EF92 jumpers, also work just as well with the pin 2 & 7 wire mod at the socket level.


----------



## Acapella11

Wow, I am so impressed withe these TS 6485, can't stop listening =).
   
  Audiofanboy:
   
  And, correctly, I read back in the thread, after, I wrote my first impressions and here was your comment:
   
  Quote: 





> ...more of those *so-realistic*-voices-you-wonder-what-you'd-been-listening-to-all-those-years -seriously- and apparently even better detail extraction -again the finger snaps on _Billie Jean_ but this time they're not just audible but right there above Michael nice and dry and snappy with a *realistic reverb *in the room, mesmerizing really-...


 
   
  Just what I wrote and thought.  They are really good. My number one at the moment.
   
  In order to answer the question in the best possible way, Audiofanboy, I made a shot. They surely are worth a good picture, and yes, O-getter and transparent. Big disadvantage of taking the pic was that I had to stop listening, haha 
   

   
   
  Mordy, OK, that was good for the socket side (seven up), but for the tube side, the left one bordering the long gap is number 1. Just hold your finger onto it whilst inserting the tube . You will be getting the hang of it =)


----------



## gibosi

Quote: 





audiofanboy said:


> Just one question Acapella, your TS 6485 are transparent and have an O-getter right, the latest construction? Just curious if there's an older construction out there too, like for the GE.


 
   
  Just an FYI, at the bottom of page 67 there is a picture of my mid 1960's TS 6485s. These are transparent but have the older square getter. So yes, there is an older construction out there....


----------



## mordy

Thanks, very helpful.
   
  The page with the picture of the 2-7 strap is on page 59 on the blog, and I have printed it out and used many times.
   
  The last entry on your list should definitively also state to tape the snapped off pins:
   
  - 6J4 / 8532(W) -> EF92 jumper + cut off pins 5 & 6 and tape stubs (cut & tape mod)
   
  Did you get my message that the Motorola 6J4 tubes were made by RCA?


----------



## Audiofanboy

Quote: 





acapella11 said:


> Wow, I am so impressed withe these TS 6485, can't stop listening =).
> 
> Audiofanboy:
> 
> ...


 
   
  Haha, at least it's reassuring to see we get similar impressions and wording to describe tubes, and it shows it can't all be placebo effect or random fluffy impressions we've been posting...
   
  Reading back a few pages to fill in the gaps in my previous post, I realized that gibosi's TS 6485 actually have a square getter (made in early 60s), so yes there have been different versions made with an change in construction -like most tubes between the 50s and 60s.
   
  I'll stop posting for a day or two now to let the thread balance itself a little, if you'll excuse me lol...


----------



## Acapella11

Audiofanboy,
   
  Very good idea. Little addition for the 6EW6 and 6CB6 tubes:
   
  - 6CB6 / 6CJ6 / 6676 -> EF92 jumper or EF95 jumper with pin 2-7 pin socket bridge / wire mod (please confirm gibosi / audiofanboy)
  - 6DK6 / 8136 -> EF92 jumper
  - 6GM6 -> EF92 jumper
  - 6EW6 -> EF92 jumper or EF95 jumper with pin 2-7 pin socket bridge / wire mod
  - 6GY6 / 6GX6 - EF92 jumper
  - 6AG5(WA) / 6J3P(-E) / 6BC5 / 6CE5 / EF96 / 6186 -> EF95 jumper
  - 6AU6(A/WA/WB/WC) / 6136 / 8425A / EF94 -> EF95 jumper + strap pins 2 & 7 at the socket level (wire mod)
  - 6AH6(WA) / 6485 -> EF95 jumper + strap pins 2 & 7 at the socket level (wire mod)
  - 6J4 / 8532(W) -> EF92 jumper + snap off pins 5 & 6 (snap & tape (?) mod)
   
  Mordy,
   
  I have only tried 4 of the new tubes and for me, between those, the ranking is:
  1) Tung Sol 6485 (6AH6, year 1971), still burning in
  2) GE 8425/6AU6
  3) Sylvania 6EW6
   
  I have to more thoroughly check out some GE 6GY6/6GX6 but they were a bit too bass light for my liking and not as balanced, so I think, I would put them on place 4.
   
  I will later post more notes on the GE 8425 and the developing TS 6485.


----------



## mordy

Great!
   
  When this list has been finalized I think that I am going to frame it and hang it on the wall next to the LD MKIII!


----------



## gibosi

Quote: 





mordy said:


> Did you get my message that the Motorola 6J4 tubes were made by RCA?


 
  Actually, the Motorola 6J4s were my tubes. 
   
  When I got the Sylvanias and compared them to the Motorolas, they looked to be identical, with the exception of thicker mica, so I just assumed that Sylvania made the Motorolas. After reading your message, it does indeed seem that RCA made them. What I find intriguing is that the RCA tubes and the Sylvania tubes look like they could have been made in the same factory. But usually, there are noticeable construction differences between brands. So it appears that RCA and Sylvania were producing identical tubes? And now I am wondering... Do AudioFanBoy's French 6J4S look different than the American tubes? Or the same?


----------



## gibosi

Quote: 





mordy said:


> First, I would like to hear a consensus and ranking about which tubes are the best sounding (as AFB did in the past). Then, after each tube, a line with the settings required. An example would be like this:
> 
> 1)Super Duper 6ABCDEFGWA EF95 setting with pins 2&7 strapped
> 2)Electron Fabulosi 3995 EF92 setting with pins 5&6 snipped off
> 3)Unobtanium 4892i EF91 setting with liquid cooling


 
  Standard disclaimer: "Old ears and cheap gears"  
   
  But it is worth keeping in mind that we have different electronics, different headphones/speakers and different preferred "sound signatures". So while I think we can agree on the best tubes, we will likely have different rankings among them:
   
  1. Sylvania 6J4/8532W EF92 setting, pins 5&6 cut, and stubs either taped or sealed with paint/varnish (I got some nail polish!)
  2. Sylvania 6AU6/6136 EF95 setting, pins 2&7 strapped
  3. GE 6485 EF95 setting, pins 2&7 strapped
  4. TS 6485 EF95 setting, pins 2&7 strapped
   
  And I received a pair of Westinghouse 6AU6/8425As today, but haven't had a chance to do more than unpack them....


----------



## mab1376

Can someone compile all of these new findings into a spreadsheet or something? i.e. everything outside of the official owners manual.
   
  so much new information everyday! I lost track after the 6AU6 finding.


----------



## gibosi

Quote: 





mab1376 said:


> Can someone compile all of these new findings into a spreadsheet or something? i.e. everything outside of the official owners manual.
> 
> so much new information everyday! I lost track after the 6AU6 finding.


 
   
  All these findings have been posted in the last twenty or so pages... If you are willing to do the grunt work, that is, comb through the postings, collect the data, and then organize everything into a spreadsheet, I would be happy to check it all over for accuracy and completeness.


----------



## Acapella11

Quote: 





gibosi said:


> Standard disclaimer: "Old ears and cheap gears"
> 
> But it is worth keeping in mind that we have different electronics, different headphones/speakers and different preferred "sound signatures". So while I think we can agree on the best tubes, we will likely have different rankings among them:
> 
> ...


 
  
 gibosi,
  
 Maybe an interesting thought to look for a little headphone upgrade in order to enjoy all your current and future tubes even more .
  
 You did quite a bit of legwork there with Audiofanboy already. Since, I have now heard a GE 8425/6AU6 and TS 6485 (6AH6), how would you compare your top Sylvania 8532W and Sylvania 6136/6AU6 to those I know. What do you prefer and why is your top tube the best? Back in the old 5654 days , I liked the Sylvania JAN 5654W quite a bit.
  
 I know it takes time to formulate a good answer. It is appreciated.
  
 PS: Would you please confirm the jumper options, which I edited in post 1077 on the last page (and add anything else you would like to add  )? Cheers.
  
  
 mab1376,
 
 The beginning of a live update is made with AFB's post 1072.


----------



## gibosi

Quote: 





acapella11 said:


> Maybe an interesting thought to look for a little headphone upgrade in order to enjoy all your current and future tubes even more .
> 
> You did quite a bit of legwork there with Audiofanboy already. Since, I have now heard a GE 8425/6AU6 and TS 6485 (6AH6), how would you compare your top Sylvania 8532W and Sylvania 6136/6AU6 to those I know. What do you prefer and why is your top tube the best? Back in the old 5654 days , I liked the Sylvania JAN 5654W quite a bit.
> 
> ... 
   
  Yes, I have been thinking a lot about getting better headphones. However, there are lots of choices and I am not having much success in narrowing it down to two or three. What makes it so difficult is that I have not had a chance to listen to really good headphones and therefore, all I have are reviews and the opinions of others. And of course, this alone is not enough to make me feel very comfortable pulling the trigger. However, there will be a Head-fi meetup in my town soon, and I am hopeful I will be able to "meet" some nice headphones. I would really like to make a purchase later this summer....
   
  The only thing I would add to your post 1077 is to emphasize that other than the "traditional" EF91/92 tubes, all the other non EF91/92 tubes that work with the EF92 jumpers also work just fine in the EF95 setting with the pin 2-7 pin socket bridge/wire mod. This would add the EF95 setting for 6DK6/8136, 6GM6 and 6GY6/6GX6 in your list.
   
  I am quite sure that the reason I am preferring the Sylvania 6136/6AU6 over the TS 8485 is very much a function of my budget headphones. The midrange on the TS 8465 seems too laid back, almost recessed. I hear a very strong base and very clear detailed highs with the midrange sucked right out. It sounds almost hollow to me.
   
  The mids of the Sylvania 6136/6AU6 are not quite as forward as the GE 8425A/6AU6 but sound very smooth and effortless, plus a razor-sharp 3-D presentation, makes these tubes much more fun and enjoyable.
   
  And the Sylvania 6J4/8532W seem very similar to the Sylvania 6136s, but better. They are very musical, the midrange is bit more forward and liquidy, high frequency percussive details are sharp and clear, and the bass seems to have more authority. And as with the other recent exceptional tubes, imaging is superb. It is a very fun tube.
   
  So in short, of course, I choose tubes that make my budget headphones sound better. Moreover, I am 66 years old and it is almost certain that my hearing is diminished to some degree. Thus I never encourage people to take my judgments too seriously -- "old ears and cheap gears"...


----------



## mordy

Hey, I am also 66, and I still trust my hearing as far as music is concerned. Here is a simple hearing test that you can do yourself. My hearing works from 20Hz to 12KHz by this test, and I believe that most music is well within this range.
   
  http://www.youtube.com/watch?feature=player_embedded&v=2G9Q-r2leyw#!
   
  Truth is that I do have certain hearing problems, not all related to selective hearing (honey, can you do this for me? etc), but with music I can always turn up the volume. To this you can also add the experience of listening to music for many years, and I am not so worried about my judgment being totally off. As with everything else, taste varies, but I definitively believe that we can come up with a list of the top five or so tubes or tube categories that will bring the greatest listening pleasure using the LD amps.
   
  The quest goes on!


----------



## gibosi

That was an interesting test. It appears my hearing works up until about 9khz. (Unfortunately, I have a little tinnitus). But yes, like you, I do not think my judgement is totally out in left field. I have been listening to music for many years and in the '80s I designed and built loudspeakers as a hobby. (My latest and greatest were 15" JBL subwoofers with Focal/Dynaudio MTM satellites). I think a quality set of headphones in the only significant "upgrade" I really need. 
   
  And yes, I think we can quite easily come up with a consensus list of top recommendations. But of course, as long as Audiofanboy is out there searching for new and promising tubes, this list will likely continue to evolve.


----------



## gibosi

A pair of Westinghouse 6AU6/8425s. These are Mordy's discovery. Until I saw his, I didn't know there were any 8425s other then GE. I am still preoccupied with the 6J4/8532Ws at present, so haven't had a chance to see if they even light up. But thought I would provide a picture.
   

   
  Interestingly, the Tek label numbers and text are different. One says "selected pair" and the other says "checked tube." Moreover, one has a square getter (dated 1962) and the other has a round getter (no date found). Obviously, this is not a Tek "matched pair". However, the eBay seller tested and matched them and I am looking forward to checking them out.


----------



## inphu510n

I bought a pair of the Westinghouse 8425s off of eBay recently and while they're not burned in I personally can't hear a lot of difference between the G.E. and Westinghouse Tek tubes. If anything the Westinghouse are a bit less in your face but just as clear. 3D detail may be a bit better as well.
  I'm curious about these tubes though. They have the etched "6AU6" with dots around it. I was under the impression that this etching/dot pattern means a G.E. manufactured tube. The getter structure is the same on both of mine but the plates are slightly different. One has four small square holes and the other four larger square holes. Definitely not an official Tek match up but they do have nearly the same date code.


----------



## Acapella11

Hallo everyone,
  
 I've edited and reformatted the current state of 'new' driver tube families and their settings to operate them. Feel free to add information. This should update everyone, who hasn't read through the thread since page 50 in order to know which 'new' tubes work and how to to operate them. The tubes have been tested with the LD I+, MKIII and MKIV.
 Best
  
   

 *Tubes*     *Jumper Settings / Mods*   *Families                       * *Alternative Names* *Remark* *EF95     * *EF91/92* *EF95 + Pins 2-7*
*Socket Wire Mod*
 *EF91/92 +*
*Cut off and tape *
*Pins 5 & 6*
 *6AG5, 6BC5, 6CE5* EF96, 6J3P(-E), 6186  yes​no​yes (2)​no​ *6AH6* 6J5P, 6485  no​no​yes​no​ *6AU6* EF94, 6136, 8425  no​no​yes​no​ *6CB6, 6CJ6* 6676  no (1)​yes​yes​no​ *6DK6* 8136  no (1)​yes​yes​no​ *6EW6*    no (1)​yes​yes​no​ *6GM6*    no (1)​yes​yes​no​ *6GY6/6GX6*    no (1)​yes​yes​no​ *6J4* 8532 Triodeno​no​no​yes​                              Recommended modes of operation are highlighted in green.
   
  (1): Operation with "floating" grid 3 is strongly not recommended.
  (2): Mod doesn't add a function. Tubes are already internally strapped between pins 2 and 7. Use at higher risk only.
     
              Tubes with A, W, WA, WB, WC specification share the same settings as the ones without.
   
  Gibosi and Audiofanboy started using triodes with the LD I+ and MKIV.
   
  
 
   
  Last but not least is here an addendum to clarify the pin numbering of the LD driver tubes and their socket. =)
   

   
  Update: 21/04/2013, highlighted recommended and riskier modes of operation.
  Update2: 22/04/2013: Operation with floating grid g3 set to fail safe mode.


----------



## MIKELAP

Quote: 





acapella11 said:


> Hallo everyone,
> 
> I've edited and reformatted the current state of 'new' tube families and their settings required to operate them. Feel free to add information. This should update everyone, who hasn't read through the thread since page 50 in order to know which 'new' tubes work and how to to operate them. The tubes have been tested with the LD I+, MKIII and MKIV.
> Best
> ... 
  Thanks man thats going to help another page to add to my littledot mk3  data folder


----------



## gibosi

One small correction: 
   
   
  6AG5, 6BC5, 6CE5 EF96, 6J3P(-E), 6186
   
  These tubes, like the 6AK5/EF95s, have pins 2 and 7 strapped internally, and thus do not require the "2-7 Socket Wire Mod".


----------



## Acapella11

Quote: 





gibosi said:


> One small correction:
> 
> 
> 6AG5, 6BC5, 6CE5 EF96, 6J3P(-E), 6186
> ...


 
   
  Hi gibosi,
   
  I know. The table is for what would work and not what you minimally need. I have removed "required" from my text in the post and edited the table to add the information . Thanks for pointing to the "required". So, for these tubes you could conveniently leave the socket bridge in and it would still work. Shouldn't make a difference, as you say, they are already internally strapped.
   
  As a conclusion, this makes the Pin 2 - 7 Wire Mod a universal fool proof tool for the 'new' pentodes mentioned in the above post.
   
  Best


----------



## mordy

The last entry 6J4/8532 Triode has NO under the column EF91/92 setting. Should it be YES? (The last column mentions the EF91/92 setting)


----------



## gibosi

I think we do not want anyone to misinterpret this chart and try to run 6J4/8532 Triodes using the EF91/92 settings without cutting pins. So in my opinion, a NO in the EF91/92 column is correct. Also, this follows the same logic as for the 6AU6 and 6AH6: A NO in the EF95 column because pin strapping is required.


----------



## Audiofanboy

Quote: 





acapella11 said:


> Hallo everyone,
> 
> I've edited and reformatted the current state of 'new' driver tube families and their settings to operate them. Feel free to add information. This should update everyone, who hasn't read through the thread since page 50 in order to know which 'new' tubes work and how to to operate them. The tubes have been tested with the LD I+, MKIII and MKIV.
> Best
> ... 
   
  Great work Acapella, it easily sums up how to use all the new tubes for people just haven't followed -or even those of us that have- the last couple dozen pages. My only fear is that the list will only get longer  ...
   
  Just two remarks though. I really would not encourage people to use all those EF92 jumper setting tubes on the EF95 setting, leaving grid 3 floating. The literature is pretty clear on the fact that you're not supposed to have stuff floating around in your tube ungrounded or unstrapped around high tension. It may work OK on many tubes, until one day, it'll cause a problem for someone with a crappy tube. At any rate, if those tube types can be easily connected properly, why not do so really. And if anything, for jumper haters, it's is still pretty easy and by-the-book to wire mod pins 2 & 7 like the 6AU6 -which would be my favorite solution- so I would only encourage those two solutions, and not the EF95 jumpers alone.
   
  And one more detail, about the 6AG5 type, not that anyone is really using it anyway. Yes, pins 2 & 7 are internally connected, so although it should work with pins 2 & 7 wire modded together, I wouldn't encourage that either, as I don't see the point of running the risk of having extra mod wires hanging around using a compatible tube, and, more importantly, having pin 2 & 7 strapped together twice could do some weird loop crap that we don't need... The same thing would be true for 6AK5 and 6AJ5 tubes btw.
   
  Don't mean to be annoying, but I would hate for people to draw wrong conclusions by looking at this table real quickly and end up doing something like connecting their brand new 6J4 triode on any setting with all 7 pins "because all those tubes seem to work on all those jumpers settings anyway, so why wouldn't that tube work on any setting like all the others, I hate changing jumpers. Grrr".


----------



## Acapella11

Hi Audiofanboy (and everyone else =) ),
  
 The table is the reflection of a team effort, so it should also include all the information for the interested reader. I have updated the table to differentiate between suboptimal and preferred modes of operation. I just do not want to hide information and _every mod and tube use outside the recommended families comes at a risk_. For example, long term effects of using a 450 mA heater current 6AH6 tube are unknown to us. It is likely that it works OK, but LD components will be stressed more potentially reaching their working tolerances. Especially in warmer countries, this may cause issues. As this is an international forum, an interested user may be reading this from India or Australia. But, as holding back information is wrong IMO, it is very useful to prioritize modes of operation, which then minimizes the risk of malfunction.
  
 To be fair, we are doing this because it is fun and because it improves a little amp, that we love, to a level it would have not reached with stock tubes. This is simply amazing. However, nothing comes for free outside the borders of official support, so if something goes wrong its each person's own risk. I agree, it is good to minimize risk. The intention of this update is to involve more people, those who might be interested and haven't read the last 23 pages yet. This could catalyze the growth of the table and allow us to find the ultimate LD driver tubes 
  
 Thanks everyone who contributed to achieve this table as it stands there, obviously especially Audiofanboy for doing a lot of work enabling us to test the families, Gibosi building up pyramids of 'new' tubes feeding us information, Mordy being totally mesmerized by 6AU6 tubes. This is an extra bit from me to let the results shine in nicer letters. I am happy to update the table based on new findings and tube families expanding our horizon.
  
 Best
   

 *Tubes*     *Jumper Settings / Mods*   *Families                       * *Alternative Names* *Remark* *EF95     * *EF91/92* *EF95 + Pins 2-7*
*Socket Wire Mod*
 *EF91/92 +*
*Cut off and tape *
*Pins 5 & 6*
 *6AG5, 6BC5, 6CE5* EF96, 6J3P(-E), 6186  yes​no​yes (2)​no​ *6AH6* 6J5P, 6485  no​no​yes​no​ *6AU6* EF94, 6136, 8425  no​no​yes​no​ *6CB6, 6CJ6* 6676  no (1)​yes​yes​no​ *6DK6* 8136  no (1)​yes​yes​no​ *6EW6*    no (1)​yes​yes​no​ *6GM6*    no (1)​yes​yes​no​ *6GY6/6GX6*    no (1)​yes​yes​no​ *6J4* 8532, 6J4WA = M8248, CV5311 Triodeno​no​no​yes​                              Recommended modes of operation are highlighted in green.
   
  (1): Operation with "floating" grid 3 is strongly not recommended.
  (2): Mod doesn't add a function. Tubes are already internally strapped between pins 2 and 7. Use at higher risk only.
     
              Tubes with A, W, WA, WB, WC specification share the same settings as the ones without.
   
  Gibosi and Audiofanboy started using triodes with the LD I+ and MKIV.
   
  
 
   
  Last but not least is here an addendum to clarify the pin numbering of the LD driver tubes and their socket. =)
   

   
  Edited 21/04/2013: Included CJ4WA information, thanks gibosi.
  Edited 22/04/2013: Operation with floating grid g3 is strongly not recommended.


----------



## gibosi

Quote: 





acapella11 said:


> The table is the reflection of a team effort, so it should also include all the information for the interested reader. I have updated the table to differentiate between suboptimal and preferred modes of operation. I just do not want to hide information and _every mod and tube use outside the recommended families comes at a risk_........But, as holding back information is wrong IMO, it is very useful to prioritize modes of operation, which then minimizes the risk of malfunction.
 
   
  Your final table is now perfect! 
   
  People who are just starting to use these new tubes can now easily find the recommended and preferred settings, or "best practices", for each and every tube. This alone is tremendously useful and helpful. Additionally, you provide information regarding several suboptimal settings a number of our members have successfully tested, and this too is very good information for those who might be comfortable with a little more risk.
   
  Five Gold Stars!


----------



## mordy

Got a little scared from A11's remark that that 6AH6 tubes may make the amp to run too hot. I just got in a couple of Sylvania 1978 6AH6WA tubes that I am burning in. They run quite hot, and the amp itself is also quite warm.
  Originally, one of our Australian members suggested mounting a computer fan near the amp, and others gave me the advice to use an old wall wart instead of an old PC power supply. I scoured my parts bin of old computer parts and discarded portable telephones and found a 41'2" computer fan and a 12 V power supply. My retired engineer friend suggested that I mount the fan so the it sucks the air up and away from the tubes instead of blowing directly on them, which was my original thought.
  Said and done. I keep my LDIII on a shelf of an audio HI-Fi rack so I jury rigged the fan hanging above the tubes. Everything works well except for that the fan makes a noise as if a mosquito is buzzing near my ear (I turned up the volume to drown it out).
  The 6AH6 tubes that were too hot to touch before can now be touched comfortably, and the chassis of the amp is as cool as a cucumber and downright cold. The Russki 6N6P power tubes are cooler, but still too hot to touch.
   
  Does anybody know if cooling down the tubes and the amp will affect performance?
   
  Another thought: Usually the 2-7 strap pulls out when I change the tubes and has to be repositioned. Perhaps a little piece of electrical tape across the middle will hold the strap in place?
   
  As to being mesmerized, David Zhe Zhe calls the LD MKIII the sweet spot in his line. I really like the amp, and the new tube families have greatly increased the amp's performance and listening pleasure. Truth is, I like almost all of the new tubes I have tried. It takes me a little time to try the new types because I am not looking to empty out my wallet on $70 pairs of tubes. I got 4 1962/3 Tung Sol and 3 Sylvania 6AH6WA for a little over $2 each. The Sylvanias are delicious - haven't gotten to the TS tubes yet. (The TS tubes were advertised as Philco tubes but the picture showed Tung Sol tubes LOL.)


----------



## zedmeco

this is really impressive and I appreciate all the effort that you have all put in but are you really suggesting that my amp, using only the ef95 tubes that I have sourced, mostly through the reviews and opinions from this site, are all rubbish when compared to these new families?


----------



## mordy

Dear Z,
   
  Not at all - whatever tubes YOU enjoy to listen to are the right ones for you. Taste is a very personal thing, and every body's equipment reacts differently to different tubes.
   
  I was perfectly happy with the tubes I was listening to, but when I tried some of the newly discovered possibilities I realized that these "new" tubes sounded better: More clarity, more punch and slam in the bass, more micro detail, more pin point imaging.
   
  One of the great things with the newly discovered tube alternatives are that they are inexpensive (if you shop right). For a few bucks you could try it out - you may find that you would like to stay with the old set-up, but you may possibly like something else better.
   
  Enjoy the magic of tube rolling!


----------



## Audiofanboy

Quote: 





zedmeco said:


> this is really impressive and I appreciate all the effort that you have all put in but are you really suggesting that my amp, using only the ef95 tubes that I have sourced, mostly through the reviews and opinions from this site, are all rubbish when compared to these new families?


 
   
  Honestly, many of those new tube types -and for that matter many EF92 and EF91 tubes before that- do show tremendous performance compared to even the best of EF95 tubes, and usually with more "power" which you end up hearing in the end in your headphones.
   
  The 6AH6/6485 tubes for instance are cheap as can be, very powerful and ultra detailed. The 6AU6 are a bit less cheap, but usually cheaper than the best EF95 tubes, and are mellow and musical, albeit less detailed than the best 6AH6. If you like your music tame and tubey, I guess you could stay with nice EF95 -which I have very fond memories of- but if you're looking for a little bit of extra oomph in your amp and that level of detail that makes your music "alive" perhaps less tubey and warm, then you really ought to try some of those new tube types.
   
  If you really only want to try one single "consensus" type, maybe wait for other impressions of the brand new 6J4 triodes, and potentially skip the 6AU6 and 6AH6 tubes for now -though I really do recommend 6485 (special 6AH6) tubes.
   
  I wouldn't worry too much about 6AH6/6485 tubes overheating the amp. Yes, the heater current is higher at 450 mA, but it's not much compared to power tubes (750-825 mA depending) and most of that heat dissipates through the glass vertically (when you have the amp on, not playing anything, the heater still heats right? Yet the amp gets really warm only when you play music through it, so it's the current and voltage going through it that heats it up, and that seems to be correlated mostly with the mu factor. The EF91 has a very high mu of 70 and it indeed heats up the amp like no other tube type I've tried when music is playing. EF91, 6AU6, 6AH6 and 6JA tube types don't significantly heat up the amp when idle despite 300-450 mA heater currents compared to 175 mA for a EF95/6AK5; and under load, the order of amp temperature would be EF91>6J4>6AH6>6AU6>EF92>EF95>6AJ5).
   
  About the two remarks I had on the tube type compatibility table, I won't insist any more than I have, but again, I would not leave grid 3 floating on tubes like 6CB6, 6DK6, 6EW6 and 6GM6, or loop pins 2 & 7 with an extra wire mod on tube types where these two pins are hardwired like the 6AG5 and 6AK5. I just don't see the point in tempting the technical devil unless really necessary...


----------



## mordy

Dear AFB,
   
  As always, thanks for your insights. I remember burning in a set EF91 tubes. The entire amp got so hot that I was afraid to leave it on.
   
  As I understand it, heat is enemy #1 of electronics, but do you think there is any disadvantage that the amp stays really on the cold side with the fan on? Is there an optimal operating temperature for the amp, or perhaps an optimal temperature range?


----------



## Audiofanboy

Quote: 





mordy said:


> Dear AFB,
> 
> As always, thanks for your insights. I remember burning in a set EF91 tubes. The entire amp got so hot that I was afraid to leave it on.
> 
> As I understand it, heat is enemy #1 of electronics, but do you think there is any disadvantage that the amp stays really on the cold side with the fan on? Is there an optimal operating temperature for the amp, or perhaps an optimal temperature range?


 
   
  I think you should be fine so long as you don't use the amp with EF91 tubes 8 hours a day in the middle of the summer... In the first place, most case when I found the amp to get really warm were "man-made" situations such as burn-in. Even on hot European summer evenings (30-40°C max), just listening to music for 30mins-2h slices of time, I never found the amp to get so hot I couldn't touch it, except perhaps in extreme cases with... EF91 tubes, considered OK by the Little Dot people. I wouldn't use a fan just because I would worry it would cause microphonics by blowing above the tubes, and noise in the room before that.
   
  Now, if you live in a desert with constant 40°C/100°F+ temperatures, I'd stick with lower gain types, or a SS amp...


----------



## Acapella11

Quote: 





gibosi said:


> Your final table is now perfect!
> 
> People who are just starting to use these new tubes can now easily find the recommended and preferred settings, or "best practices", for each and every tube. This alone is tremendously useful and helpful. Additionally, you provide information regarding several suboptimal settings a number of our members have successfully tested, and this too is very good information for those who might be comfortable with a little more risk.
> 
> Five Gold Stars!


 
   
  Thanks Gibosi, appreciated =)
  It should allow every 'new' one to access the 'new' tubes with more ease.
   
  Quote: 





> Originally Posted by *mordy* /img/forum/go_quote.gif
> 
> As to being mesmerized, David Zhe Zhe calls the LD MKIII the sweet spot in his line. I really like the amp, and the new tube families have greatly increased the amp's performance and listening pleasure. Truth is, I like almost all of the new tubes I have tried. It takes me a little time to try the new types because I am not looking to empty out my wallet on $70 pairs of tubes. I got 4 1962/3 Tung Sol and 3 Sylvania 6AH6WA for a little over $2 each. The Sylvanias are delicious - haven't gotten to the TS tubes yet. (The TS tubes were advertised as Philco tubes but the picture showed Tung Sol tubes LOL.)


 
   
  Mordy, Lol, I have ordered also Sylvanias 6AH6WA tubes (JAN for that matter). Let's see how we like them. The Tung Sols are amazing. They really make the amp shine IMO.
   
  Quote: 





zedmeco said:


> this is really impressive and I appreciate all the effort that you have all put in but are you really suggesting that my amp, using only the ef95 tubes that I have sourced, mostly through the reviews and opinions from this site, are all rubbish when compared to these new families?


 
   
  Zedmeco, I wouldn't say EF95 tubes are rubbish. As I recently posted, I put my Sylvania JAN 5654W tubes back in and enjoyed them. Nicely defined bass actually. However, I switched already earlier to CV4015 (EF92) because I found them more resolving and neutral. So, moving away from EF95 was old business in a way. The new tubes offer new flavours, which you should taste  That's what this is about and IMO the LD MKIII wins quite some attraction using them. Audiofanboy illustrated already differences betwenn 6AU6 and 6AH6 tubes. You can use this as a guide. My personal taste is more for the 6AH6. At least my Tung Sol 6485 tubes are so resolving, neutral, balanced and detailed. Highly recommended if you like this signature.


----------



## zedmeco

ok, I'm up for it. just ordered these, are they the right ones? what do i need to do to the amp to make them work?
   
  http://www.ebay.co.uk/itm/261150136993?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649


----------



## gibosi

Quote: 





zedmeco said:


> ok, I'm up for it. just ordered these, are they the right ones? what do i need to do to the amp to make them work?
> 
> http://www.ebay.co.uk/itm/261150136993?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649


 
   
  Refer to Acapella11's chart above, post #1096. The 6485 is a very high quality computer/industrial version of the 6AH6. So these will require that you put your LD in the EF95 setting and use two little wires to strap pins 2 and 7 together in both sockets.
   
  Enjoy!


----------



## fruitflavor

it seems while I was away people have been getting very creative with rolling.
  Need to get few that people have been using to how they are.
   
  If someone likes to roll more "normal tubes" there's few good 5654/6ak5 on the bay
   
  5 raytheons
http://www.ebay.com/itm/Sleeve-of-Five-Raytheon-USA-6AK5-Vacuum-Tubes-Little-Dot-/130890309622?pt=Vintage_Electronics_R2&hash=item1e79ab9ff6
  
  questionable (unknown quality) GE 5 stars
http://www.ebay.com/itm/4-GE-5654-FIVE-STAR-TUBES-TESTED-/221217352484?pt=Vintage_Electronics_R2&hash=item338194eb24
   
  rather rareish sylvania GB 5654 gold brands
http://www.ebay.com/itm/Pair-Sylvania-Gold-GB-5654-6AK5-EF95-JAN-tube-little-dot-dark-voice-NOS-/111056468933?pt=Vintage_Electronics_R2&hash=item19db7b3bc5
http://www.ebay.com/itm/NOS-Sylvania-Gold-Brand-USA-GB-5654-403B-6AK5W-Black-Plate-106-Vacuum-Tube-/121091877232?pt=Vintage_Electronics_R2&hash=item1c31a36970
   
  want to try RCA command but they're rather difficult to come by but inexpensive.
  and always available for cheap, my fav GE 5654w in my LDII


----------



## Audiofanboy

The fun never stops, here are a few new tube rolling ideas. As usual, each new tube type is even more obscure than the previous one lol.
   
  This time, it's 7-pins double diode-triodes. Yeah, it seems barbaric, but it's actually pretty simple. It's a triode, with two useless diodes in the same glass bulb, which you can just, well, not use, getting a triode in the end. Many of these are described in the datasheets as having similar characteristics to half of a -famous- 12AX7 or 12AT7 type tube. They tend more towards the high or very mu and low gm, meaning they should be perfect for a voltage gain section (driver tube) in the MK III & IV, just like their 12V heater double triode counterparts massively used in preamps and headamps around the globe. Well, used by a few thousand people at least...
   
  So far I've identified the 6AT6, 6AQ6 and 6AV6. There are more 7-pins diode-triodes (one diode plate pin and one extra cathode lead pin) and double diode-triodes (same shared cathode, two diode plate pins), but they aren't all easy to make compatible (if the anode is on pin 1 instead of the grid, it's seems difficult to adapt with wire mods, unless making a whole 7-pin adapter, which is entirely possible btw). Like the 6J4, albeit for different reasons, these would require you to chop off pins 5 & 6 (diode 1 & diode 2, simple really) and use EF92 jumpers!
   
  Note that you should supposedly be grounding those unused diodes, though many people apparently could care less and leave them floating, but that is not an ideal case. But the 6AT6 and 6AV6 are often recommended as "single 12AX7" and just too interesting not to test, and pretty cheap too apparently.
   
  I'll wait for my current ordered tubes and replacement tubes to get to me first before delving any deeper into these.
   
  That's all I have for now...


----------



## mordy

Hi AFB,
   
  I've been waiting for this post, and I am looking forward to see what you will find. I have my eyes on a cheap deal of RCA/Sylvania 6J4 tubes. Should I hold off and wait to find out if the diode/triode tubes are better sounding? Half of 12AX7/12AT7 sounds enticing.
   
  Truth is, I thoroughly enjoy almost all of the new tubes I've tried, such as the 4825/6AU6 and the 6AH6. But if good is good, better is better......
   
  I also notice that the new tube categories you list above come in European designations, so in addition to the standard Sylvania, RCA, Tung Sol and GE variants, it seems that you can get Phillips, Mullard and Siemens tubes as well etc. .
   
  If you really want to get into the 6AV6 tube rolling mode, there is a T shirt available LOL.
   
  http://www.ebay.com/itm/12AX7-VACUUM-TUBE-T-SHIRT-LRG-RCA-6AV6-ECC83-/320961636314?pt=Vintage_Electronics_R2&hash=item4abacde7da


----------



## mordy

Sorry, the link does not work with red letters:
   
   
  http://www.ebay.com/itm/12AX7-VACUUM-TUBE-T-SHIRT-LRG-RCA-6AV6-ECC83-/320961636314?pt=Vintage_Electronics_R2&hash=item4abacde7da


----------



## gibosi

Quote: 





mordy said:


> I've been waiting for this post, and I am looking forward to see what you will find. I have my eyes on a cheap deal of RCA/Sylvania 6J4 tubes. Should I hold off and wait to find out if the diode/triode tubes are better sounding? Half of 12AX7/12AT7 sounds enticing.


 
   
  I encourage you to go for them. My Syl 8532W/6J4s are my current favorites, and I seriously doubt that standard Syl 6J4s wouldn't sound just as good. As for these newly discovered diode/triodes, it is impossible to know how they will sound at this time. As usual, I have ordered some inexpensive samples, but don't expect delivery until the end of this week, or early next.


----------



## Acapella11

Quote: 





audiofanboy said:


> Note that you should supposedly be grounding those unused diodes, though many people apparently could care less and* leave them floating*, but that is not an ideal case. But the 6AT6 and 6AV6 are often recommended as "single 12AX7" and just too interesting not to test, and pretty cheap too apparently.


 
   
  Oh, no. Absolutely, you can't do that, lol 
	

	
	
		
		

		
			




   
   
  Quote: 





audiofanboy said:


> The fun never stops, here are a few new tube rolling ideas. As usual, each new tube type is even more obscure than the previous one lol.
> 
> This time, it's 7-pins double diode-triodes. Yeah, it seems barbaric, but it's actually pretty simple. It's a triode, with two useless diodes in the same glass bulb, which you can just, well, not use, getting a triode in the end. Many of these are described in the datasheets as having similar characteristics to half of a -famous- 12AX7 or 12AT7 type tube. They tend more towards the high or very mu and low gm, meaning they should be perfect for a voltage gain section (driver tube) in the MK III & IV, just like their 12V heater double triode counterparts massively used in preamps and headamps around the globe. Well, used by a few thousand people at least...
> 
> So far I've identified the 6AT6, 6AQ6 and 6AV6. There are more 7-pins diode-triodes (one diode plate pin and one extra cathode lead pin) and double diode-triodes (same shared cathode, two diode plate pins), but they aren't all easy to make compatible (if the anode is on pin 1 instead of the grid, it's seems difficult to adapt with wire mods, unless making a whole 7-pin adapter, which is entirely possible btw). Like the 6J4, albeit for different reasons, these would require you to chop off pins 5 & 6 (diode 1 & diode 2, simple really) and use EF92 jumpers!


 
   
  Excellent, more exotic food for us and let us know how they sound, then I'll update the table =D
   
  Quote: 





mordy said:


> Sorry, the link does not work with red letters:
> 
> 
> http://www.ebay.com/itm/12AX7-VACUUM-TUBE-T-SHIRT-LRG-RCA-6AV6-ECC83-/320961636314?pt=Vintage_Electronics_R2&hash=item4abacde7da


 
   
  This one is great.
   
  Btw, anyone of you at the Head-fi meet in London on Saturday?


----------



## mordy

In my relentless quest for the Unobtanium tube, I came across some tubes labeled Sonotone. Thinking that they must be re-branded, I did a little research. True, they used re-branded tubes from Mullard and Telefunken among others, but they also manufactured their own tubes in the 40's - 60's in the USA. The tubes I looked at say "Made in USA".
   
  Does anybody know anything about the quality of their US made tubes (as compared to the major US brands)?
   
  [size=16.0pt]"By the 1950's Sonotone was making over 400 different tubes. The automated tube manufacturing equipment was located at the Elmsford factory. The progressive line was circular, about 20 feet in diameter. There were many gas jets at each step to heat the glass and shape it. It was very impressive to watch. Some of the tubes were made by other manufacturers with the Sonotone name on them. Some were made by Telefunken, Mullard and Amperex. An economy line was later introduced with tubes made in Japan and were sold in green boxes. By the mid-sixties, tube sales decreased with the advancement of transistors. The tube manufacturing equipment was sold[/size]."


----------



## Audiofanboy

Quote: 





mordy said:


> Hi AFB,
> 
> I've been waiting for this post, and I am looking forward to see what you will find. I have my eyes on a cheap deal of RCA/Sylvania 6J4 tubes. Should I hold off and wait to find out if the diode/triode tubes are better sounding? Half of 12AX7/12AT7 sounds enticing.
> 
> ...


 
   
  I'd love to tell you to wait for the 6J4 because they're great or something, but as haven't even gotten my Sylvania 8532W yet, I can't. I keep bringing up new tube types that I'm not even the first person to test; I've basically fallen behind in my own game lol...
   
  Which reminds me I finally got my replacement TS 6485 (1971-72, O-getter, last version), and these are still some great awesome tubes. I realize that even more now after spending a full week with my French 6J4S in the meantime. Those 6485 are a grade in themselves, and anyone ought to try a pair; they are my current best tubes by a fair margin.
   
  Now, a few pictures, as I just realized I hadn't actually taken pictures of the last three tubes I tested. No pics of the boxes this time, as I just didn't feel it added much information, and I preferred to focus on close-ups of the tubes for once (pics are full high resolution if you click on them). I do hate how doing macro at silly small apertures reveals how dirty you camera's sensor is; you never see those dust specks at normal apertures...
   
  First, a bit of tube porn. I think I'd mentioned how I broke a 6J4S tube by bending its pins, and that the glass broke off so neatly, I thought I should take a picture of it, well here it is. See how the grid (the only grid, it's a triode) goes further than the anode width.
   

   
  The 6J4 (all the ones I've seen have this exact same construction, save for minor mica changes) has a pretty peculiar build with weird shaped anodes held by a U bent sheet of metal; fascinating to look at outside of the glass.
   

   
  The unbroken, yet mutilated *Thomson-CSF 6J4S*. See how a little bit of glass got chipped off when I bent the pins.
   

   
  My West German mil-spec *Valvo (Mullard Blackburn) EF94*, very well built tubes I have to say, nice and heavy feel. Good luck finding those!
   

   
  And my current favs, the *Tung Sol 6485*. This is the first pair I got, and the left tube is now dead (new pair is on the amp). Notice how the left tube has some degree of black grainy screening and the other one has none. It's weird, as these two tubes have the exact same code on them, and the same export dates (Germany) on the boxes. It's even more evident on my replacement pair, where one tube is almost all black, and the other one is perfectly transparent.


----------



## mordy

Dear AFB,
   
  I am trying out these Tung Sol 6AH6WA tubes. As you noted, the glass on my tubes also have a black sooty looking screening which makes it a little hard to see everything clearly. These are the only tubes I have with two dates on them: On the glass on top over the silver cap is etched a date 6210 followed by USA 7. The printed date on the tube is 6251. Could the earlier date be the manufacturing date and the second date the packing date?
   
  The sound is excellent. They look very similar to your 6485 tubes, but the getter is rectangular:


----------



## mordy

I did not know that by double clicking on the picture you get a full view. If you click on the third picture the two dates are visible - one date on each tube on this picture.


----------



## Acapella11

Audiofanboy, Thumbs up from me: TS 6485 
	

	
	
		
		

		
		
	


	



  Mordy, Interesting to see the differently build JTL-6AH6WA. Would be curious to hear these.
  
  Edit: Yes, Gibosi, you posted also the JAN 6AH6 with square getter. Sorry, forgot about that.


----------



## mordy

The reason I put up the pictures was that I thought that the TS 6H6WA should be very similar to the TS 6485. Now I have another proof: The left tube died suddenly; the same experience AFB had.
   
  Luckily I have four tubes, so I don't have to go through TS 6H6WA withdrawal, but I really find it strange that one tube died after around 30 hours. This is the first time for me that a tube died in use suddenly. Makes me worry about the others...


----------



## gibosi

And on page 61, post 915, I uploaded a picture of a pair of 1961 TS JAN-6AH6. Your tubes, my JAN tubes and my TS 6485 (page 67, post 1005) are all 1960s vintage and seem to be identical, including the square getter.
   
  Oh, I am happy to report that none of mine have failed...


----------



## Acapella11

Hey guys,
   
  Just now I found something interesting in terms of power tubes, a possibly useful alternative, which is also well used in audio.
   
   
 "The 12BH7 double triode is pin compatible with the ECC81, ECC82 and ECC83 series from Mullard but has slightly different characteristics. Brimar give the intended use as TV frame oscillator and frame output. The construction is compatible with audio through to low VHF use. The thin glass tube envelope is 19 mm in diameter and, excluding the B9A base pins, is 68 mm tall."   
  Here is the layout of the base. The two cathode sections are interchanged, but I think that shouldn't be a problem. Only relevant difference between 6N6P and 12BH7(A) seems pin 9, which is a center tap heater for 12BH7 and a center shield pin for 6N6P. Sounds to me like a heater bridge wire mod from one of the other two heaters to pin 9 should make 12BH7 compatible. What do you guys think? I have merged the pin layouts in the figure below.


----------



## Audiofanboy

Quote: 





acapella11 said:


> Hey guys,
> 
> Just now I found something interesting in terms of power tubes, a possibly useful alternative, which is also well used in audio.
> 
> ...


 
   
  I do wonder what they mean by "heater center tap". I'd assume the heater works fine powered through the usual B9A pins 4 & 5, and that pin 9 just has some weird random function, that may not be necessary. I guess whether to just chop off pin 9 on this one or bridge it depends on what pin 9 is connected too at the socket level (if it is indeed used as the shield, it should/would/I guess it is connected at the source, therefore the cathode (?)). I'd take a look at the MK III PCB pics to figure it out and make sure.
   
  Out of curiosity, and before I check it out tomorrow at fresher times of the day for my time zone, what is the 12BH7's selling point compared to the 6N6P?
   
  At any rate, yey to more options lol! (though 6N6P & 6N30P are recognized as very very good double triodes in the first place)
   
  Edit: I see, 12AT/U/X7 lineage. That explains the interest. And it has a high-ish heater current compared to its counterparts, though low compared to a 6N6P. To be investigated I guess, though the amp may be more sensitive to power tube type changes than driver tube types (power types being quite critical). Of course being a 12v heater tube makes things a bit more complicated...


----------



## GrindingThud

Pin 4 to 5, 12V heater....pin 4/5 to 9 6v use. Pin9 is a center tap.



audiofanboy said:


> I do wonder what they mean by "heater center tap". I'd assume the heater works fine powered through the usual B9A pins 4 & 5, and that pin 9 just has some weird random function, that may not be necessary. I guess whether to just chop off pin 9 on this one or bridge it depends on what pin 9 is connected too at the socket level (if it is indeed used as the shield, it should/would/I guess it is connected at the source, therefore the cathode (?)). I'd take a look at the MK III PCB pics to figure it out and make sure.
> 
> Out of curiosity, and before I check it out tomorrow at fresher times of the day for my time zone, what is the 12BH7's selling point compared to the 6N6P?
> 
> At any rate, yey to more options lol! (though 6N6P & 6N30P are recognized as very very good double triodes in the first place)


----------



## duncan1

Audiofanboy- In Europe unlike America those   tubes with a center tap were used in series heater configurations in European TVs .
                          European TVs used the dangerous engineering construction of one side of the electrical mains connected DIRECTLY to the chassis[think of reversal of plug connections so LIVE is connected to chassis.]
                             The US used mainly MAINS TRANSFORMERS there bye isolating the electrical supply from the TV.
                               And yes  some died here from electrocution so everything that had bare metal was shrouded.
                                   The only logical engineering concept  in those TVs was in series  with the live [240V-here] connection.
                                      But to make them more "universal" the center tap was added.
                                          Series heaters usually had to have the same current drain as each other to even up the flow of current through them.
                                               You could add a resistor across the heaters-SERIES working ONLY to even out one with a different current drain
                                                  But that was inefficient as the resistor could be several Watts and radiated a lot of heat.
                                                       Why did manufacturers use direct mains connection rather than an isolation mains transformer???--
                                                           Think -money.


----------



## Audiofanboy

So basically this type of tube will work of a 6V heater source if you "double connect" the heater pins to the center tap (and the whole thing to 6V at the socket level), so in parallel I guess?


----------



## duncan1

Look on the heaters as 2 resistors connected together at the center tap the  current flow through both will be the same 2 equal resistances connected in parallel the total resistance is HALVED[more current used] if connected to the other heater connection at the center  tap.    Applying  12V across -4+5 without using the CT will reduce the amount of current through them for use in other equal current heater circuits.by INCREASING the total resistance[lower resistance=higher current].[higher resistance=lower current]
                      So "double connect"-IE- shorted together 4+5 and the other heater connection to 9-AFTER you have removed the earth connection to it.


----------



## mojorisin35

I appreciate all the effort that you have all put in to working out all these fantastic tubes. I love my ld mkiii and remain transfixed with all the tube possibilities.
  I have just received my tek ge 8425 and to my ears these are great tubes. The instrument separation is impeccable and the cleanness across the frequencies is refreshing. It is like that thin veil that was there with the best of the ef 91 92 95 tubes has been lifted. It is hard to imagine the TS 6485 being truly a world above but I trust what others have said and I look forward to my pair making it across the ocean.
  I still enjoy the tubes from the other families but now it is like matching wine with your meal instead of one wine for everything. Am I the only one who does this, has the drive to discover the ultimate do it all tube relinquished all your previously loved tubes to the dust bin?
  I would love to upgrade my power tubes to the 6h30 family and to that end I will insert a shameless plug to my ad where I am selling my surplus tubes to fund a supertube purchase/trade.  Look here http://www.head-fi.org/t/659457/little-dot-tubes-ef95-ef92-ef91.
  Gary


----------



## gibosi

A couple new tubes arrived in the mail today:
   
  Below are a pair of Sylvania 6AQ6 which combines two diodes with a high-mu triode voltage amplifier. They have 150mA heaters, like the 6AK5, but an amplification factor of 70! Also notice that they have side-getters and the tops of the tubes are clear.  As with the 6J4, we need to cut off pins 5 and 6 and set our LD in the EF92 mode to use these tubes.
   
  These particular tubes are fairly old as they have green writing and came in green Sylvania boxes, maybe 1950s?
   

   

  Next, a pair of Sylvania 6AV6, another two diode/high-mu triode voltage amplifier. These are essentially the same as the 6AQ6 except thay have 300mA heaters and an amplification factor of 100!!!  And again, we will need to cut off pins 5 and 6 and set our LD in the EF92 mode.
   

   

  Later today, I will cut pins and begin burning...
   
  But now I want to revisit the Tung Sol 6485...
   
  I have been a bit bothered by the fact that my experience with the TS 6485 has been so much different than that of A11 and AFB. For the most part I have substantially agreed with their impressions of all the new tubes we have been trying, and it just didn't make any sense to me that my TS 6485 sounded nothing like what they have been describing.... 
   
  Last night, on a whim, I installed my 1961 Tung Sol JAN-6AH6. I didn't remember being negatively impressed while burning them in a month ago, and thought it might be interesting to listen to them again. I was shocked! I had forgotten how good these sounded! Moreover, they are nothing like my TS 6485?! 
   
  For some reason my TS 6485 do not sound like my older JAN-6AH6. And apparently, my TS 6485 do not sound like those of A11 and AFB. But this presents another mystery. Are my mid-60s TS 6485 with square getters an aberration?
   
  Anyway, I am quite sure my JAN-6AH6 sound like Mordy's JTL-6AH6WA. And I am quite sure they sound like A11's and AFB's TS 6485. However, in order to test this further, I have ordered a second pair of TS 6485, but newer, with round halo getters. But for now, I am quite certain we have consensus that these Tung Sols are in the top tier of the best of the best we have tried. 
   
  In my mind the Sylvania 6J4/8532W are also in the top tier, but they are somewhat different than the TS 6485. I think it comes down to a matter of taste. Per AFB, the 6J4 are "musical, mellow and a little bassy" while the TS 6485 are "ultra-detailed and balanced -read occasionally treble-oriented- with a great stage." And perhaps one might say, more "analytical". Anyway, I feel that they are equally good, but different.
   
  However, it appears that I am the only one who has listened to the Sylvania 6J4/8532W to date.  AFB should be getting his soon, and after a few more people report their impressions, we will know if these Sylvanias are also a consensus top tier tube.
   
  At this point in time, I wholeheartedly recommend the TS 6485 as long as you get the round halo getters. And I also recommend the older mil-spec TS JAN and JTL tubes. These Tung Sols are really, really good. 
   
  Edited to fix typing error: Should be 6485 and not 8564.


----------



## Acapella11

Quote: 





gibosi said:


> A couple new tubes arrived in the mail today:
> 
> Below are a pair of Sylvania 6AQ6 which combines two diodes with a high-mu triode voltage amplifier. They have 150mA heaters, like the 6AK5, but an amplification factor of 70! Also notice that they have side-getters and the tops of the tubes are clear.  As with the 6J4, we need to cut off pins 5 and 6 and set our LD in the EF92 mode to use these tubes.
> 
> ...


 
   
  Gibosi, sounds exciting, we are curious =)
    
  Quote: 





> Anyway, I am quite sure my JAN-6AH6 sound like Mordy's JTL-6AH6WA. And I am quite sure they sound like A11's and AFB's TS 8465. However, in order to test this further, I have ordered a second pair of TS 8564, but newer, with round halo getters. But for now, I am quite certain we have consensus that these Tung Sols are in the top tier of the best of the best we have tried.


 
   

  Do you mean TS 6485?
   
    
  Quote: 





duncan1 said:


> Look on the heaters as 2 resistors connected together at the center tap the  current flow through both will be the same 2 equal resistances connected in parallel the total resistance is HALVED[more current used] if connected to the other heater connection at the center  tap.    Applying  12V across -4+5 without using the CT will reduce the amount of current through them for use in other equal current heater circuits.by INCREASING the total resistance[lower resistance=higher current].[higher resistance=lower current]
> So "double connect"-IE- shorted together 4+5 and the other heater connection to 9-AFTER you have removed the earth connection to it.


 
   
  Duncan1, Thanks for making this clear. I shall now check my sources for a curious roll, at least one


----------



## Audiofanboy

Quote: 





gibosi said:


> A couple new tubes arrived in the mail today:
> 
> Below are a pair of Sylvania 6AQ6 which combines two diodes with a high-mu triode voltage amplifier. They have 150mA heaters, like the 6AK5, but an amplification factor of 70! Also notice that they have side-getters and the tops of the tubes are clear.  As with the 6J4, we need to cut off pins 5 and 6 and set our LD in the EF92 mode to use these tubes.
> 
> ...


 
   
  I really would not be surprised if there were a difference between older -D-getter- and later -O-getter- Tung Sol 6485 (yes, I'm sure Gibosi meant 6485 all along lol). My TS 6485 from 1970-1972 really do sound glorious. And to answer mojorisin (you must have been impressed by the 8425A, since you're selling your stock of EF95/2/1 right?), yes the whole 6485 (not necessarily the whole 6AH6 family, if you read my reviews the Raytheon and Sylvania JAN 6AH6WA back 5-10 pages ago) family is a whole grade above the 8425A, especially the Tung Sol 6485.
   
  In my experience, both with US and UK tubes, the latest construction tubes (final internals and O-getter, though not from the last production years) sounded better than their earlier counterparts. This has been the case especially with UK EF91 types and US 6485 (early GE 6485 with D-getters do not sound like the later O-getter dark glass versions, not at all in fact) and also for US 6AK5 types.
   
  Sadly, I STILL have not received my 8532W tubes, so I cannot compare them to the TS 6485...
   
  Edit: Gibosi, what odd looking tubes, these 6AQ6 and 6AV6 are; side getters are pretty unusual and point to fairly old production tubes. It's funny how non-top-getter-flash tubes look so weird compared to the near universal top-getter-flash versions -save for power triodes which often have side or bottom getters and look great.
   
  Shameless Edit: still selling a pair of 6N30P-DR, which I still highly recommend to take your amp to another level and your music to a different world (especially paired with our current top-tier tube choices!).
  http://www.head-fi.org/t/654419/supertubes-matched-nos-6n30p-dr-electro-harmonix-6h30pi-gold


----------



## gibosi

Quote: 





acapella11 said:


> Do you mean TS 6485?


 
   
  Yes.... Sometimes when I am typing these tube names with four numbers, they get all jumbled up...  (>_<)  lol Anyway, went back and fixed my typos.
   
  And wouldn't you know? In this afternoon's mail, my second set of TS 6485 arrived. Unlike my older set, these are not at all transparent and they have military style date codes. Dated 1967 with halo getters and most importantly, even though they have been in my LD for only about 30 minutes, they sound like my 1961 TS JAN-6AH6, and not at all like my older TS 6485 with square getters.
   
  Life is good!


----------



## mojorisin35

AFB “And to answer mojorisin (you must have been impressed by the 8425A, since you're selling your stock of EF95/2/1 right?), yes the whole 6485 (not necessarily the whole 6AH6 family, if you read my reviews the Raytheon and Sylvania JAN 6AH6WA back 5-10 pages ago) family is a whole grade above the 8425A, especially the Tung Sol 6485.”
   
  True I am impressed with the 8425A however just to be clear I am selling my backups not my collection.
  I have read every page of this thread and cannot believe the expertise within this thread. Everybody is friendly and helpful; there are very few threads on the internet in my experience where people’s opinions and ideas are respected without any flaming. Well done!
  I can't wait to see where this thread continues to grow.
  Gary


----------



## mordy

Decided to do a shootout between the Tung Sol JTL 6AH6WA  smoked glass tubes (hereafter referred to as TS 6AH6) and the Westinghouse Tektronix matched 6AU6A/4825A (hereafter referred to as the W4825) tubes.
   
  The most striking thing with the TS 6AH6 tubes is the utter clarity and effortless reproduction of all frequencies with pinpoint imaging and a wide sound stage. Micro details, such as a musician saying something to another player or tapping his foot or the fingers making a sound when sliding over guitar strings come through clearer than any other tube I tried, and, as said before, you hear details in the music that you did not hear before. The bass has good slam and attack, and as mentioned, the tube is very balanced and neutral and simply beautiful to listen to. Usually I listen to speakers, but I tried them with my Audio Technica ATH-AD700 headphones. This turned out to be a great match. These headphones are said to be a little bass shy, but I did not notice it with the TS 6AH6 tubes.
   
  My other favorite was/is the W4825 tubes. These are warmer and less analytical but ultimately lack some of the utter clarity of the TS 6AH6 tubes. They have a little more slam and attack when playing percussion and are more bright in my system. The bass is more round and full than the TS 6AH6 tubes. The sound stage is slightly larger, and strangely enough they seem to have more power when playing very loud compared to the TS 6AH6s. (I don't think this applies to people who listen through headphones.) Very sweet tubes which I could happily live with.
   
  In summary, if I did not try the TS 6AH6 I would have been perfectly happy with the W4825 tubes. But if good is good, better is better, so the nod goes to the glorious TS 6AH6 tubes.
   
  Until the next great discovery comes along......


----------



## Audiofanboy

Quote: 





mordy said:


> Decided to do a shootout between the Tung Sol JTL 6AH6WA  smoked glass tubes (hereafter referred to as TS 6AH6) and the Westinghouse Tektronix matched 6AU6A/4825A (hereafter referred to as the W4825) tubes.
> 
> The most striking thing with the TS 6AH6 tubes is the utter clarity and effortless reproduction of all frequencies with pinpoint imaging and a wide sound stage. Micro details, such as a musician saying something to another player or tapping his foot or the fingers making a sound when sliding over guitar strings come through clearer than any other tube I tried, and, as said before, you hear details in the music that you did not hear before. The bass has good slam and attack, and as mentioned, the tube is very balanced and neutral and simply beautiful to listen to. Usually I listen to speakers, but I tried them with my Audio Technica ATH-AD700 headphones. This turned out to be a great match. These headphones are said to be a little bass shy, but I did not notice it with the TS 6AH6 tubes.
> 
> ...


 
   
  I just spent another evening with my TS 6485, these still take me by surprise with the way _things inside the music_ leap at me through my headphones.
   
  Surely you speak of 8425A tubes right mordy, lol? But yes, those are exactly like my impressions of the step/grade between the best 6AU6A/8425A and the best 6AH6/6485 tubes. The -for instance GE- 8425A were beautiful to behold, musical and detailed, a revelation in and of themselves, but the first GE 6485 tubes I got showed just how much of that ultra-realistic detail I could get out my amp, and the TS 6485 took that a full grade further. Adjectives like balanced, pinpoint imaging, and super detailed are my exact thoughts to which I would just add -and that is what makes the whole difference- realistic. Only a few tubes I've had sound truly realistic and manage to really throw me -temporarily- into a beautiful world of music, or basically inside the studio and artists/audio engineers' mind: the TS 6485, the GE 6485 (both later O-getter versions, GE is less realistic but still a revelation), and to a lesser extent and easier on the ear, the Mullard EF94. That effect, while easier to get on speakers, is pretty impressive and actually quite mind blowing on good headphones. It reminds me just why I blow so much cash on audio gear lol, when I can't stop the toe-tapping effect and just listen to a few hours of music instead of testing my new tubes, I know I've hit a goldmine.
   
  Now, you've all got me interested in a direct comparison between:
  - Old world TS 6485 with D-getter
  - Latest TS 6485 with O-getter
  - TS JTL 6AH6WA with D-getter
  - TS JTL 6AH6 with O-getter (which have a different "nub" than my 70s 6485 btw gibosi)
   
  Just so we're able to know which is similar to which, and which production to buy.


----------



## mordy

One thing that I find astonishing is that there is such a great sense of consensus of our findings, even though we use totally different equipment and listen to very different types of music. In addition, we are located in different parts of the world. (The common denominator, of course, is the LD amps.)
   
  One reason is that we all report our findings honestly and allow room for different opinions. To me, it is amazing that I can trust the opinions of the people on this blog to the extent that I will not hesitate to buy tubes based on the recommendations here. And due to the efforts and research of the members new vistas seem to open up all the time - curious to see which tube will end up on the top when the tube alphabet has been exhausted....
   
  Happy tube rolling!


----------



## Acapella11

Now, I would like to take the opportunity to introduce a new family of LD tubes to you: The* Heptode *for Pentagrid Conversion Applications (6BE6 / 6BE6N) =)
   
  Here it is, photographed as Sylvania JAN 5750, packed in September 1975:
   

   
  It works in Pin 2/7-strapped wire mod or EF91/92 operation (I wouldn't say EF95, would I  ).
   
  Because this is a new kid on the block, here are useful technical details:
   

   
 These have only four hours on the meter, so first impressions only: So far, I am tempted to put them on GE 6AU6A level. Not quite TS 6485. In comparison to GE 6AU6A: the sound is opener, more spacious, somewhat wetter for more spatial information (echoes, reverb etc), holographic impression is not a precise as with the 6AU6A, and they are ever so slightly not as smooth, but tubier than the TS 6485. I do really love the stage. They sound somewhat clear as in the no part of the frequency spectrum attempts to overwrite the other. The signature is well balanced. Treble is nicely extended, not harsh, not too mellow, bass has a good weight, reasonably tight, as in better than 6EW6, not as hard as TS 6485 but a bit more weight than these. Because it is mellower than the TS 6485, it lacks little of this dead neutral CV4015-like precision and also the pin-pointing is not a accurate as with the 6AU6A. However, overall, I would say the grade could be similar to the GE 6AU6A at the moment. Maybe too much text for a first impression, lol.
 Let's see how and whether the tube develops during the burn in process.
   
  Quote: 





mordy said:


> One thing that I find astonishing is that there is such a great sense of consensus of our findings, even though we use totally different equipment and listen to very different types of music. In addition, we are located in different parts of the world. (The common denominator, of course, is the LD amps.)
> 
> One reason is that we all report our findings honestly and allow room for different opinions. To me, it is amazing that I can trust the opinions of the people on this blog to the extent that I will not hesitate to buy tubes based on the recommendations here. And due to the efforts and research of the members new vistas seem to open up all the time - curious to see which tube will end up on the top when the tube alphabet has been exhausted....
> 
> Happy tube rolling!


 
   
  I am amazed about that, too. Great work indeed.


----------



## Audiofanboy

Yes, it is really is pleasant to know that you can trust people's opinions here and happily make your tube shopping list based on the consensus of -always polite and respectful- opinions. That kind of pleasantness, that allows for broader opinions and creativity, doesn't just happen magically though, it's obviously because of everyone effort to keep things productive and nice (besides, a troll would be quickly disarmed by the lack of response he'd get here lol, and probably go back to more feisty thread to troll). Many similar threads are much less amusing to browse through lol...
   
  Great, heptodes! I'd had a few written down in my notes for a while, just waiting for investigation, and I believe that Alain person (the guy who had mysteriously tried many new tubes types by himself a year ago, and never gotten ant responses) had tried one or two of them. Funny thing is that at the socket level, all those extra grids are pre-strapped together, so it makes no functional difference compared to a pentode. There are a few more compatible ones out there though, I'll look through what I'd written down.
   
  At any rate, so 6AU6 level apparently? That would already put these at the top or second top tier, which is pretty amazing for random tubes (I don't think we've bumped in to a bad or really mediocre tube for a while now, so we must be doing something right). Look forward to your review after 15-20 burn-in! Btw, any other common brands for these (GE, TS...)?
   
  Edit: There other 7-pin heptodes: 6CS6 and 6BY6. All three tubes families have a ton of special types too, it's always worth getting those.


----------



## mordy

Btw, any other common brands for these (GE, TS...)?
   
  Looked through the 6BE6/5750 offerings on EBay - there are plenty of them. (Can anybody explain why there are so many sellers that only offer a single tube? And when I ask the seller a question, nine times out of ten, they don't have a pair.)
   
  All the major brands are represented as well some European equivalents. IMHO, based on my 6AK5 odyssey, I would always try to include Tung Sol tubes.


----------



## Acapella11

Quote: 





audiofanboy said:


> At any rate, so 6AU6 level apparently? That would already put these at the top or second top tier, which is pretty amazing for random tubes (I don't think we've bumped in to a bad or really mediocre tube for a while now, so we must be doing something right). Look forward to your review after 15-20 burn-in! Btw, any other common brands for these (GE, TS...)?
> Edit: There other 7-pin heptodes: 6CS6 and 6BY6. All three tubes families have a ton of special types too, it's always worth getting those.


 
   
  Audiofanboy, On ebay, the largest variation and number of offers is available for 6BE6 tubes, between 6BE6, 6CS6 and 6BY6. Matched pairs etc... There are loads of options as Mordy already pointed out. I will keep you posted, ordered a pair of TS tubes, too.
   
  Quote: 





mordy said:


> Btw, any other common brands for these (GE, TS...)?
> 
> Looked through the 6BE6/5750 offerings on EBay - there are plenty of them. (Can anybody explain why there are so many sellers that only offer a single tube? And when I ask the seller a question, nine times out of ten, they don't have a pair.)
> 
> All the major brands are represented as well some European equivalents. IMHO, based on my 6AK5 odyssey, I would always try to include Tung Sol tubes.


 
   
  Thanks Mordy, TS sounds good to me too. Let's check this family out a bit.
   
   
*6BE6* and sound sensitivity to *jumper *settings:
   
 This is now still quite preliminary, but here it comes : There is a sound difference between jumper settings. If my first impressions are true, EF91/92 would sound more open, with more "zing" in the treble, less tubey, and more revealing, compared to 2/7-socket strap or EF95 float. On the other hand you lose some bass weight. It is like two tubes for the price of one . For me the EF91/92 setting cleans up the sound a bit and makes it more interesting. I might need to edit this statement later. Interestingly, on the tube side of things, the anode strapped grids 2 and 4 would then be  "in-line" with the anode strapped grid 3.


----------



## gibosi

Quote: 





acapella11 said:


> *6BE6* and sound sensitivity to *jumper *settings:
> 
> This is now still quite preliminary, but here it comes : There is a sound difference between jumper settings. If I my first impressions are true, EF91/92 would sound more open, with more "zing" in the treble, less tubey, and more revealing, compared to 2/7-socket strap or EF95 float. On the other hand you lose some bass weight. It is like two tubes for the price of one . For me the EF91/92 setting cleans up the sound a bit and makes it more interesting. I might need to edit this statement later. Interestingly on the tube side of things, the anode strapped grids 2 and 4 would then be  "in-line" with the anode strapped grid 3.
 
   
  With the tubes that we can run in either the EF91/92 setting or the socket-strapped EF95 setting, it seemed to me that there could very likely be some differences depending on whether these extra grids are strapped to the cathode or the anode. Five stars to you for checking this out! 
   
  And I have ordered a pair from each of the 7-pin heptode families:
   
  GE JG-5750 6BE6W
  Tung Sol 6CS6 Eh90
  RCA JRC-5915
   
  Re: 6AQ6/6AT6/6AV6, I started with the 6AV6 and am pleased to report no fireworks or explosions!  First impressions, the bass was a bit tubby and flabby, and the mids and highs seemed a bit congested. However, with about 20 hours on them the bass has tightened up and the midrange and highs seem to have opened up as well. These are now very musical, warm with a well-rounded bass, quite nice I think. I hope to find time this evening to closely compare the EF92, 6J4 and the 6AV6. Also, the 6AT6 arrived today and my plan is to take pictures and post them tomorrow.


----------



## Acapella11

Quote: 





gibosi said:


> With the tubes that we can run in either the EF91/92 setting or the socket-strapped EF95 setting, it seemed to me that there could very likely be some differences depending on whether these extra grids are strapped to the cathode or the anode. Five stars to you for checking this out!
> 
> And I have ordered a pair from each of the 7-pin heptode families:
> 
> ...


 
   
  Thanks Gibosi, the differences are quite noticeable but not huge.  Cool, more 6BE6 fun then, looking forward to your impressions. You should also have tube fun this weekend with 6AQ6/6AT6/6AV6 tubes. Enjoy.


----------



## Johnnysound

Quote: 





audiofanboy said:


> Yes, it is really is pleasant to know that you can trust people's opinions here and happily make your tube shopping list based on the consensus of -always polite and respectful- opinions. That kind of pleasantness, that allows for broader opinions and creativity, doesn't just happen magically though, it's obviously because of everyone effort to keep things productive and nice (besides, a troll would be quickly disarmed by the lack of response he'd get here lol, and probably go back to more feisty thread to troll). Many similar threads are much less amusing to browse through lol...
> 
> Great, heptodes! I'd had a few written down in my notes for a while, just waiting for investigation, and I believe that Alain person (the guy who had mysteriously tried many new tubes types by himself a year ago, and never gotten ant responses) had tried one or two of them. Funny thing is that at the socket level, all those extra grids are pre-strapped together, so it makes no functional difference compared to a pentode. There are a few more compatible ones out there though, I'll look through what I'd written down.
> 
> ...


 
   
  This is my very first post in this forum,  just to concur with Audiofanboy when he says that you can trust people's opinions here, which have been very useful to me.  I am not new to high def audio,  (in fact, I have a long experience)  but have to confess that headphones were not exactly my priority (kind of heresy said here).  I do have an excellent pair of  vintage Stax electrostatics and some mid range Sennheisers, but I simply was not into it, until I saw  some highly positive comments in this forum about the LD MKIII, so I decided to give it a try.  Paired in stock form with my relatively modest but splendid-sounding  Audio Technica ATH-M50 LE (Anniversary Edition), the result was really astounding.
   
 Since this is a tube rolling thread,  I do not want to go off-topic, so let me say that I followed the excellent guide from Dept of Alchemy  and replaced the stock GE 5654  tubes with a pair of Voshkod 6J1P-EV gold/platinum grid,  NOS military tube ("OTK" rhombus seal) made in the 1980´s in the Voshkod plant,  Kaluga city, sent to me from an Ebay seller directly from Moscow at a cost of around $ 18 the pair (including postage).  Authentic military stuff, these Russian tubes are clearly extremely  well made, solid and sturdy, a little bigger than the stock ones.  I wonder what its military use was in the Cold War, I suspect they were made by the thousands so there is still a big stock of NOS tubes you can get at around $ 3 each.  Very interesting historical piece, it was obviously not made for commercial purposes but for reliability and ruggedness, so its original cost must have been much higher, no problem for the mighty URSS military budget.  
   
Before I give my humble sonic impressions as a newcomer in this forum of  headphone experts,  I must say that I am fully aware that a closed back headphone is not the ideal tool to evaluate  the LD MKIII.  It really needs a good open back HP to be appreciated.  I am thinking seriously in the HD 650 or Beyer 800 series. (My wife will kill me if she ever find out the price of these) I do favor a dynamic but natural sound, with precise, not overextended bass and very good soundstage.  Any suggestions ?     
   
On the other hand,  a good studio monitoring HP like the ATH-M50 LE is like a microscope.  Maybe not much soundstage or spatial clues, but It will reveal a lot of detail in the music and has superior bass rendition.   My feeling was that the stock GE 5654 tubes are not that bad,  as stated in the "rolling guide",  in the sense that these tubes are rough and have bad midrange or highs. Perhaps not so delicate and yes, an "upfront" presentation,  but overall a nice, balanced, dynamic sound with more than adequate bass, and they improve a lot  after about 50 hs, of use.  The Voshkods, however, are a different story.  With no burn in at all these tubes inmediately revealed themselves as high definition ones.  Suddenly,  there was more music and more information:  powerful and tight bass, extended highs,  great midrange and a superior spatial rendition of the performance, very  dynamic and revealing.  However, after my initial positive impressions, and after listening to a lot of different music ( jazz, rock, classical, latin, etc.)  with some VERY demanding HD recordings in both 24/96 and 24/192,  going to the limit, the Voshkods showed a kind of "over the edge" quality with some HD music at perhaps the 2k to 4k range resulting in  some  mild "hardness" in the midrange. The highs were surely very extended, but not as sweet as I would like.  I have no doubt that a good burn in will solve some of this problems.  It is kind of funny that I am talking about one or two tubes here when the people in this forum have experience with hundreds of them. Well, this is the good thing, as Audiofanboy said, I will trust your advice...


----------



## gibosi

Yesterday, a pair of 6AT6 arrived. I thought it was about time I put some genuine GM parts in my LD! 
   

   
   

   

  Actually, these are made by Sylvania, tube code 312-139, perhaps 1961? I figured since these were selected for use in automobiles, they should be pretty durable. However, as I am still working with the the 6AV6 and 6AQ6, I haven't had a chance to see if they even light up. 
   
  For those of you who are sitting on the fence, trying to decide between the Sylvania 6J4/8532W and these 6AQ6/6AT6/6AV6, I believe that the 6AQ6/6AT6/6AV6 are just a bit better. (To the best of my knowledge, these three are all variations of the same tube.) I was able to spend some time last night comparing the 8532 and 6AV6. They are actually very similar, but the 6AV6 is bit more forward. Vocals and horns are front and center and crystal clear, and wetter, I think. Moreover, the sound stage is very spacious, wide and deep, with great detail, clarity and separation. At times simply breathtaking. Of course, this shouldn't be a complete surprise as these are essentially one-half a 12AX7...
   
  I think it is unfortunate that the guy with the worst ears and the cheapest gear got these first. I simply don't have the vocabulary or the experience to put into words what I am hearing. However, I do believe these are very good tubes. We will have to wait until those with better ears and gear have a chance to check these out to see if they are as good as I think they are.


----------



## gibosi

Quote: 





mojorisin35 said:


> I still enjoy the tubes from the other families but now it is like matching wine with your meal instead of one wine for everything. Am I the only one who does this, has the drive to discover the ultimate do it all tube relinquished all your previously loved tubes to the dust bin?


 
   
  While I intellectually understand where you are coming from, like wine, selecting a particular tube to suite the current mood or genre of music, I guess I seem to be programmed to want just one tube, a superlative "all rounder." And yes, I am afraid that all my previously loved tubes have been relegated to the bottom of the pile...
   
  But even if you are the "only one", there is room here for everyone, the more the merrier!  So when your TS 6485s finally arrive, please give us your impressions.


----------



## gibosi

Quote: 





johnnysound said:


> This is my very first post in this forum....
> 
> However, after my initial positive impressions, and after listening to a lot of different music ( jazz, rock, classical, latin, etc.)  with some VERY demanding HD recordings in both 24/96 and 24/192,  going to the limit, the Voshkods showed a kind of "over the edge" quality with some HD music at perhaps the 2k to 4k range resulting in  some  mild "hardness" in the midrange. The highs were surely very extended, but not as sweet as I would like.  I have no doubt that a good burn in will solve some of this problems.


 
   
  Welcome! 
   
  You might want to search this thread for "TESLA 6F32V".  These tubes seem to be similar to the Voshkods but with better highs.
   
  On the other hand, if you are willing to get two little pieces of wire and connect pins 2 and 7 in the socket, I would encourage you to order a pair of Tung Sol 6485 with round getters. These are head and shoulders above your Voshkods.


----------



## MIKELAP

Im exited today saw my tube guy at flea market and got a pair of 6ew6 and 6cb6a for $4 .00 would of gotten more of the new tubes but didnt remember the numbers so ill go back tomorrow and hopefully he has the 6au6a tubes or 6ah6, 6at6 i think if i left out a couple feel free to refresh my memory .


----------



## gibosi

Quote: 





mikelap said:


> Im exited today saw my tube guy at flea market and got a pair of 6ew6 and 6cb6a for $4 .00 would of gotten more of the new tubes but didnt remember the numbers so ill go back tomorrow and hopefully he has the 6au6a tubes or 6ah6, 6at6 i think if i left out a couple feel free to refresh my memory .


 
   
  The 6AT6, 6AV6 and 6AQ6 are very similar, so if you can't find a pair of 6AT6, maybe you can find one of the others. Also, see if he has a pair of 6485 (6AH6) or 8425 (6AU6). Good luck!


----------



## MIKELAP

Quote: 





gibosi said:


> The 6AT6, 6AV6 and 6AQ6 are very similar, so if you can't find a pair of 6AT6, maybe you can find one of the others. Also, see if he has a pair of 6485 (6AH6) or 8425 (6AU6). Good luck!


 
  Thanks for the imput will send him an email  to make sure that he brings some along if he has any .


----------



## Johnnysound

Quote: 





gibosi said:


> Welcome!
> 
> You might want to search this thread for "TESLA 6F32V".  These tubes seem to be similar to the Voshkods but with better highs.
> 
> On the other hand, if you are willing to get two little pieces of wire and connect pins 2 and 7 in the socket, I would encourage you to order a pair of Tung Sol 6485 with round getters. These are head and shoulders above your Voshkods.


 
 Many thanks for your welcome.   As I said, I never did "tube rolling" before, but now I think it is very interesting to experiment with tubes, specially with  headphone amplifiers.  No speakers, no room to fill, no pre or power amp, no cables to worry about.  The sound of a particular tube is inmediately apparent in this very high definition environment, something that do not happens so easily with speakers ¡  In fact, the Voshkods have some particular characteristics in musical terms which you may or may not like,   but are extremely revealing, so I discovered that you can use them as a kind of laboratory tool to fine tune your system, particularly computer audio/DAC settings.  Differences in sampling frequencies (for example) can be subtle, and with the stock tubes It took a little effort to perceive, but with the Voshkods the differences jumped out instantly.  However, I am not interested in spectrum analyzers but in music, so I will search the Tesla tubes you suggest.  Thanks for the advice.  Regarding the Tung Sols, you really scared me with that wires in the tube sockets ¡¡


----------



## mordy

Dear Gibosi,
   
  I don't think that you have to be so bashful. My hearing isn't the greatest but I still feel confident that I can identify and differentiate good tubes from bad. The description that you give of the 6AV6 tube is perfectly adequate and informative. (The only thing I didn't understand is what you mean with "wetter".)
   
   
  " I think it is unfortunate that the guy with the worst ears and the cheapest gear got these first. I simply don't have the vocabulary or the experience to put into words what I am hearing. "
   
  "For those of you who are sitting on the fence, trying to decide between the Sylvania 6J4/8532W and these 6AQ6/6AT6/6AV6, I believe that the 6AQ6/6AT6/6AV6 are just a bit better. (To the best of my knowledge, these three are all variations of the same tube.) I was able to spend some time last night comparing the 8532 and 6AV6. They are actually very similar, but the 6AV6 is bit more forward. Vocals and horns are front and center and crystal clear, and wetter, I think. Moreover, the sound stage is very spacious, wide and deep, with great detail, clarity and separation. At times simply breathtaking. Of course, this shouldn't be a complete surprise as these are essentially one-half a 12AX7..."
   
  Now about your gear. The following little story is appropriate:
   
  A couple had invited another couple for dinner. After the meal the husband of the guest couple showed beautiful pictures from a recent trip. The hostess kept on saying over and over again: Wow, such pretty pictures - you must have a very good camera! Finally, the guest had enough, and said to the hostess as they were leaving: Thank you for such a nice and delicious dinner - You must have very good pots!
   
  It's not just the equipment; it's what you do with it. Thanks for all your research and new exploits!


----------



## gibosi

Quote: 





johnnysound said:


> Regarding the Tung Sols, you really scared me with that wires in the tube sockets ¡¡
 
   
  When you have some time, check out post #876 on page 59.  A number of us are successfully using tubes requiring this little mod and no one has reported any problems.


----------



## gibosi

Quote: 





mordy said:


> It's not just the equipment; it's what you do with it. Thanks for all your research and new exploits!


 
   
  Thank you. I do the best I can. 
   
  Oh, "wetter" in my mind means "more liquid".


----------



## hypnos1

Hi folks. This is my first post, having near brain burn-out after checking out nearly all the entries for LD tube info - mine being  the MKiv se...what a fabulous piece of kit for not too much money.
   
  The Senn HD650s are really singing now, even after the Heed CanAmp -  which I thought  was brilliant!
   
  Have tried various driver tubes, and thought the Voskhods were about the best, until the Telefunken 6AK5Ws opened things up even more (to my ears anyway). Then I tried the Teslas... had a bit of a weird sound at first, but after a decent burn-in became quite exciting. Similar to the Telefunken in detail and soundstage, but with a bit more weight to the bass.
  There is just one caveat however - unfortunately 4 out of the 5 I acquired from 2 different sources are exhibiting microphonic "ringing", and the 5th gave such a bright flash from the lower inner wires each time on power-up that I have discarded it already.
  It would appear Czech quality control may not be on a par with the Germans or Russians...Perhaps I was just extremely unlucky - shame...
   
  Anyway, am awaiting the new discoveries of wonderful people like AudioFanboy, viz TS 6485s, which hopefully will remove the quandary.
   
  Ah well, must get some dinner, so will have to sign off for now - but will be back before too long methinks. Have caught the bug (LD that is)!!
   
   
  .


----------



## Audiofanboy

Quote: 





hypnos1 said:


> Hi folks. This is my first post, having near brain burn-out after checking out nearly all the entries for LD tube info - mine being  the MKiv se...what a fabulous piece of kit for not too much money.
> 
> The Senn HD650s are really singing now, even after the Heed CanAmp -  which I thought  was brilliant!
> 
> ...


 
   
  +1 for the MK IV SE. Fabulous piece of equipment for the price really, and pretty nice looking imo. Equipped with the best Russian missiles power tubes and some American 6485 driver tubes, it shows performance that I think puts it close to the $1K price point for a head amp, imho of course. Never heard the MK III, but I'm sure 80% of what I said if also true.
   
  If you've never tried anything outside of the 6AK5 family, the 6AU6 and 6AH6 types might come as a bit shock at first, it may be difficult to go back lol...


----------



## Acapella11

Hey,
   
  Firstly, Gibosi, you are a great part of the team and thanks for your contributions, appreciated.
  With respect to Hi-Fi vocabulary, check this glossary:
   
  http://www.head-fi.org/t/220770/describing-sound-a-glossary
   
  Wet is mostly used as "a reverberant sound, something with decay. Opposite of Dry." Think a tiled large room as wet, a dampened small room as dry.
  Of course, you can define what you mean, then that is also fine.
   
  Secondly, I am following the burn in of the *Sylvania JAN 5750 (6BE6)*.
  To me the, the formerly reported sonic differences hold, so I advise to test the *EF91/92* setting first, so you get an idea, what I consider as the better setting. You lose some bass weight, but you win openness, presence and dynamics. IMO it is the best option.
   
  Here is a list of differences comparing Sylvania JAN 5750 (6BE6) and Tung Sol 6485 (6AH6) tubes:
  - The 5750 volume level is relatively low for a 'new' tube. I would say a bit below CV4015 (EF92). That makes a quite a bit lower volume than the 6AH6 or 6AU6 tubes, I have heard.
  - The 5750 has a pitch dark  background. Also, the signature is somewhat darker but very enjoyable.
  - Bass quality is good. Not as lose as 6EW6, not exactly as tight as CV4015, TS 6485.
  - Treble is extended and sounds not rolled off, only not exactly airy because of the signature.
  - Laid back sound compared to CV4015, TS 6485.
  - Imaging would be a draw, possibly slight advantage for the TS because of the more trebly presence.
  - The sound is nicely detailed, pretty much on par with TS 6485.
  - Stage is slightly larger for the 5750 compared to TS 6485
   
  In summary, I would describe the tube as dark in comparison and rather laid back with a great stage and very good detail. Now, the dark part is not taken as negative, the signature still sounds balanced, a bit warmer than CV4015, not too mellow, useful for long listening sessions.
   
  Grade, ...difficult. As the tube changes, some of the treble I have quite enjoyed melts down, taking some openness. I think, I will wait for the final grade, but it surely is an enjoyable tube.
   
*Table of Compatible Tubes*​   
  Find an example from Audiofanboy for the strapping wire below the table. I have also made a figure for the EF91/92 strap whilst in EF95 mode of operation, thanks Audiofanboy for the finding.
   
  Compatible LD amps: I+, MKII+, MKIII, MKIV (SE)
   

 *Tubes*    *Jumper Settings / Mods*​*Families                       *​*Alternative Names*​*Remark*​*EF95     *​*EF91/92*
  = EF95 + 6/7-wire mod (1)​*EF95 *
*+ *
*2/7-Socket Wire Mod*​ ​*EF95 *
*+ *
*1/7-Socket Wire Mod*​*EF91/92 (1)*
*+ *
*Cut off and tape *
*Pins 5 & 6*​   *6AG5, 6BC5, 6CE5* EF96, 6J3P(-E), 6186  yes​no​yes (2)​no​no​ *6AH6* 6J5P, 6485  no​no​yes​no​no​ *6AU6* EF94, 6136, 8425, 7543 = mil spec 6AU6  no​no​yes​no​no​ *6BA6* (7) 5749, EF93, CV454, Shuguang 6K4  no (8)​no​yes​no​no​ *6BJ6* (9) CV3909, 6662, 7694, E99F  no (3)​yes​yes​no​yes​ *6CB6, 6CJ6* 6676  no (3)​yes​yes​no​no​ *6DK6* 8136  no (3)​yes​yes​no​no​ *6EW6*    no (3)​yes​yes​no​yes​ *6GM6, 6AM6* 6AM6 =  CV4014, EF91, CV138  no (3)​yes​yes​no​no​ *6GY6/6GX6*    no (3)​yes​yes​no​yes​ *6J4, 6AQ4* 6J4 = 8532, 6J4WA = M8248, CV5311 / 6AQ4 = CV4070, CV417, EC91 Triodeno​no​no​yes​no​ *6AQ6, 6AT6, 6AV6*   Diode / Triodeno​no​no​yes​no​ *6BE6, 6CS6, 6BY6* *6BE6 *= EK90, CV4012, 5750, 6A2P, 1217 , 1680, 6H31; *6BY6* = EH900, 6687, EH900S, EH960, E91H, 5915; *6CS6* = EH90 Heptodeyes (4)​yes​yes (5)​no​yes (6)​ *6HZ6, 6DT6* (10)    yes​yes​yes​no​yes​ *6AN5* (11)    yes​no​no​no​no​ *6HA5, 6HM5, 6HQ5* (12) 6HA5 = EC900 Triodeyes​no​no​no​no​ *6BD6*    no​no​yes​no​no​   
  Recommended modes of operation are highlighted in green.
   
        (1) EF91/92 = EF95 + 6/7-wire mod. See figure below.
   
    (2): Mod doesn't add a function. Tubes are already internally strapped between pins 2 and 7. Use at higher risk only.
   
  (3): Operation with "floating" grid 3 is strongly not recommended.
  (4): Offers a great standard setting. Floating grid 3 but different grid architecture to (1).
  (5): works flawless, preference dependent, bass heavy with rolled off treble for some 6BE6, for other 6BE6 and generally heptodes, this setting sounds brighter and more foreward than unstrapped.
  (6): "Grid-to-grid strap", possibly, favourite option for 6BY6 heptodes, generally a good setting to try.
   
  (7): Tested with Shuguang 6K4.
   
  (8): Not recommended but works with Shuguang 6K4.
   
  (9): Tubes of this family have not been tested yet (29/07/2013)
   
  (10) 6HZ6 uses 0.45 A heater current, 6DT6 0.3 A. Similar to heptodes, these pentodes are FM-detectors. Thanks Gibosi.
   
  (11) 6AN5 tubes follow the EF95 pinout and grid design but utilize a higher heater current (0.45 A). Thanks
  Siles1991.
   
  (12) ~ 0.19 A heater current triodes with µ ~ 72 that internally strap pins 2 and 7 to the cathode. Thanks Kvtaco17 and Gibosi.
   
   - Tubes with A, W, WA, WB, WC specification share the same settings as the ones without.   - CV versions usually indicate (improved) mil spec versions, specifically when used with four letters (thanks AFB).     Gibosi and Audiofanboy started using triodes with the LD I+ and MKIV.      
 
   
  Here is an addendum to clarify the pin numbering of the LD driver tubes and their socket:
   

  (1) This figure below is to give you an alternative way for switching to EF91/92 compatibility whilst running in Little Dot EF95 mode. Just create a shorter jumper than for the Pin 2/7 strap and connect positions 6 and 7. =)
   

  Updated 21/04/2013: Included 6J4WA information, thanks gibosi.
  Updated 22/04/2013: Operation with floating grid g3 is strongly not recommended.
  Updated 28/04/2013: Included Diode/Triodes and Heptodes, added EF91/92 compatibility socket jumper while running in Little Dot EF95 mode, thanks Audiofanboy.
  Updated 14/05/2013: Altered EF95 setting entry for 6BE6, 6CS6, 6BY6 since this setting provides a different sonic experience.
  Updated 16/05/2013: Included 7543 (mil spec 6AU6, thx Nic Rhodes) tubes, 6AQ4 alternative names and mil spec (thanks gibosi & AFB), added MKII+ compatibility, thanks vic2vic. Added 6AM6.
  Updated 22/05/2013: Heptode setting for EF95 put into green colours.
  Updated 27/05/2013: Added alternative names for heptodes.
  Updated 24/06/2013: Updated heptode nomenclature, floating grid comment and 1/7-strap.
  Updated 25/06/2013: Added 1/7-strap to 6EW6 and 6GY6/6GX6.
  Updated 04/07/2013: Updated some info to the experience of 1/7- and 2/7-strapping of heptodes, alternative 6BE6 designations and most - importantly -  the colour for no .
  Updated 19/07/2013: Table reformatted and slightly updated.
  Updated 20/07/2013: Added two new families: 6BJ6 and 6BA6. Modes of operation are not tested for 6BJ6. Included EF91/92 alternative mode of operation in header. Re-organized footnotes.
  Updated 06/08/2013: Added 6HZ6 and 6DT6 pentodes.
  Updated 21/08/2013: Added 6AN5 pentode.
  Updated 25/08/2013: Added 6HA5, 6HM5, 6HQ5 triodes.
  Updated 01/09/2013: Added 6BD6 remote-cutoff pentode (thanks Mordy).
  Updated 03/09/2013: Corrected the headline of the last column of the table from pins 5&7 to 5&6. Thanks Gibosi.


----------



## gibosi

Quote: 





acapella11 said:


> With respect to Hi-Fi vocabulary, check this glossary:
> 
> http://www.head-fi.org/t/220770/describing-sound-a-glossary


 
   
  Thanks! This is very helpful and I will definitely consult it the next time I try to report on how tubes sound. 
   
  In today's mail, more tubes. First a pair of RCA JRC-5915/6BY6, dated 1964:
   

   
  And a pair of GE JG-5750/6BE6W dated 1959:
   

   
  I hope to get to these soon....


----------



## MIKELAP

Theres one thing i would like to know is how much you guys paid for the latest tubes .here are the prices i was quoted from my guy are those prices in line with what you guys paid the 6AT6, 6AH6WA, 6AU6A, those are $5.00 each and they are General Electric and the 8425A are $10.00 each. no shipping involved. Thanks.


----------



## MIKELAP

Hey,
  
 Firstly, Gibosi, you are a great part of the team and thanks for your contributions, appreciated.
 With respect to Hi-Fi vocabulary, check this glossary:
  
 http://www.head-fi.org/t/220770/describing-sound-a-glossary
  Thanks for the link Acapella11 shurely is going to help me describe tubes to.


----------



## Audiofanboy

Quote: 





mikelap said:


> Theres one thing i would like to know is how much you guys paid for the latest tubes .here are the prices i was quoted from my guy are those prices in line with what you guys paid the 6AT6, 6AH6WA, 6AU6A, those are $5.00 each and they are General Electric and the 8425A are $10.00 each. no shipping involved. Thanks.


 
   
  All the last batches of tubes I bought cost me anywhere between -converted to US $- 4 and $14 when you include shipping. The most expensive I bought recently were the Sylvania 8532W, which I have yet to get (which is quite frustrating considering those are the most expensive driver tubes I've bought in the last month or two)...
   
  The 6AH6/6485 family has pretty stable and fairly cheap prices; not that much to select from anyway, though they are quite amazing.
   
  The 6AU6/8425A family is kind of all over the place in terms of pricing, but still cheaper than all those horrifyingly overrated 6AK5 tubes, save for the $30-40 Telefunken EF94 and 20$ used Mullards...
   
  The 6AT6 family has quite a bit of variety, so prices are all over the place as well but not that expensive, and the premium -which I would still get over the plain-Jane ones- are closer to $10 a tube than not. It seems that some of these are clearly identified as half of a 12AT7 and are starting to corresponding prices, only a few though. Again, you could get really cheap basic RCAs or such for $2-3.
   
  And finally, the brand new 6BE6 family has tremendous variety, and I haven't quite figured out the price pattern for these -or the similar 6BY6 family btw- but prices seem to be between $5-15 closer to 10 for premiums.
   
  Hope that helps, I have a couple more families that I'm currently investigating, so things might get even more confusing lol!


----------



## mordy

Hi Mikeleap,
   
  Part of the fun is to try to get good deals on the tubes. This involves looking through the many different offers on Ebay, communicating with sellers (asking what they have and combining shipping), and being patient. To date I have not payed more than $8 for any one tube, and many times much less. However, sometimes it involves buying four or more tubes. (It could be that I am caving in one day and spending the $200 on a set of DR power tubes - nah, I'll rather buy another back up Little Dot MkIII amp instead - just kidding!)
   
  All prices include shipping:
  For the 6AH6WA tubes (Tung Sol and Sylvania - altogether 7 tubes) I paid $2.11 each.
  For the 6AU6A/4825A Tektronix matched tubes I paid $12.84 for each set of GE and Westinghouse; for a second set Westinghouse without Tektronix labels I paid $10.
   
  This seller:  http://stores.ebay.com/TUBEHUNTER  still has GE 6AU6/4825 for $9.84 for a pair, and the Westinghouse Tektronix 6AU6A/4825A for $12.84/pair. (Shipping is free for the US - don't know about Canada). He also has an assortment of 6AU6 tubes for around $1 and change if bought in a lot.)


----------



## gibosi

Quote: 





audiofanboy said:


> The 6AT6 family has quite a bit of variety, so prices are all over the place as well but not that expensive, and the premium -which I would still get over the plain-Jane ones- are closer to $10 a tube than not. It seems that some of these are clearly identified as half of a 12AT7 and are starting to corresponding prices, only a few though. Again, you could get really cheap basic RCAs or such for $2-3.


 
   
  And the 6AV6 is purportedly half of a 12AX7....
   
  Interestingly, I cannot find any "premium" versions?  I usually check here
   
  http://www.radiomuseum.org/tubes/tube_6at6.html
   
  to find other variants, and no premium or "other class quality" versions are listed for any of the 6AT6 family tubes. So my assumption is that the premium versions are in fact the military versions....
   
  On a whim, I searched google for "best 12AX7 tube" and was somewhat surprised to find that RCAs are often listed quite high. So perhaps $2 RCAs from the 6AT6 family might be well worth trying. My Sylvanias sound great but I just might try some cheap RCAs next.


----------



## gibosi

*Strapping Pins in the Socket: Best Practices*
   
*1. Use stranded wire. Do not use solid core wire.*
   
*2. Use a socket tester during periods in which many tubes are being compared and evaluated.*
   
  As Audiofanboy was using 26 gauge stranded wire, I figured that 30 gauge solid core, which is significantly smaller, would actually be better. However, in hind sight, I now understand that solid wire plus the pin stretches the springs in the pin hole considerably more than stranded wire, even though 26 gauge stranded wire is fatter. As a result, the springs in pins 2 and 7 of my Little Dot have been stretched to the point where there is no longer enough tension to grip the tube pins tightly.
   
  If these were the old phenolic sockets, it would be a simple matter to re-tension the springs using something like a very small jewelers' screwdriver or a dental tool. However the ceramic sockets in our LDs do not permit the insertion of such a tool behind the spring.
   
  For now, I have to insert a piece of wire into pins 2 and 7 to use any tube. Below is a picture of a 6AT6 with these wires. Moreover, I usually have to roll the tube around a bit to finally make a good connection. Obviously, in its current state, I can no longer swap tubes easily and conveniently.
   

   

  Again, I recommend the use of *only stranded wire* to strap pins in our Little Dots.  And perhaps, for our Tung-Sol 6485 and other top tier tubes which require strapping, maybe we could send them to *Inphu510n* as he has evidently perfected the art of soldering wires onto tube pins? 
   
  If you are going to do a lot of tube swapping while strapping pins in the socket, I strongly recommend the use of a socket tester like the one below.
   

   

   


   

  As you can see, it is very simple to use standard hookup wire inserted next to the copper test points in order to do your strapping on the socket tester, completely eliminating the risk of stretched springs in the socket.
   
  I purchased these from Leeds Radio for only $7 each. 
   
  Further, for my situation,I have looked into having the sockets replaced, but it would cost more than just buying a new LD 1+, as a new one costs only $110. For now, I intend to purchase some longer machine screws that will be inserted all the way through the middle hole of the ceramic socket to enable me to bolt the socket testers to the ceramic sockets with a nut and washer underneath. I am hopeful this will work well.


----------



## hypnos1

Quote: 





johnnysound said:


> This is my very first post in this forum,  just to concur with Audiofanboy when he says that you can trust people's opinions here, which have been very useful to me.  I am not new to high def audio,  (in fact, I have a long experience)  but have to confess that headphones were not exactly my priority (kind of heresy said here).  I do have an excellent pair of  vintage Stax electrostatics and some mid range Sennheisers, but I simply was not into it, until I saw  some highly positive comments in this forum about the LD MKIII, so I decided to give it a try.  Paired in stock form with my relatively modest but splendid-sounding  Audio Technica ATH-M50 LE (Anniversary Edition), the result was really astounding.
> 
> Since this is a tube rolling thread,  I do not want to go off-topic, so let me say that I followed the excellent guide from Dept of Alchemy  and replaced the stock GE 5654  tubes with a pair of Voshkod 6J1P-EV gold/platinum grid,  NOS military tube ("OTK" rhombus seal) made in the 1980´s in the Voshkod plant,  Kaluga city, sent to me from an Ebay seller directly from Moscow at a cost of around $ 18 the pair (including postage).  Authentic military stuff, these Russian tubes are clearly extremely  well made, solid and sturdy, a little bigger than the stock ones.  I wonder what its military use was in the Cold War, I suspect they were made by the thousands so there is still a big stock of NOS tubes you can get at around $ 3 each.  Very interesting historical piece, it was obviously not made for commercial purposes but for reliability and ruggedness, so its original cost must have been much higher, no problem for the mighty URSS military budget.
> 
> ...


 
  Hi fellow newcomer to this forum.
   
  Re. your interest in the Senn HD650, may I say that I have been overwhelmed by the sound (or should I say "sonic experience") of these when fed by the amazing MKiv SE - and so, I should imagine, the MKIII. It seems to me they fulfil pretty much all the criteria you mentioned, assuming a good source...I must admit I have probably helped things along by replacing the stock cable with one I made up using 8-stranded pure silver cable, but the stock is still pretty good!
   
  I do however feel I must guide you - if you are not already there  -  to follow the threads from Audiofanboy, Gibosi et al with regard to the latest discoveries they have made concerning driver tubes. So long as you are happy implementing the wire modification they mention, taking careful note re the "cleanliness" of insertion and use of thin STRANDED wire, I would urge you to forego the VERY lengthy burn-in time needed for the Voskhods (mine had 100+ hours!) and go for the Tung Sol 6485s. Have just received mine, and straight out of the box were far superior to the Voskhods and the Tesla 6F32s others have mentioned. After just 10 hours' burn-in the sound coming through the Senns is nothing short of unbelievable...I am in sonic heaven!
   
  I suggest you read all the threads you can find on this topic and I am sure you will find the confidence, as I did, to discover what the LD can really do - not to mention the Sennheisers.
   
  Good luck.


----------



## vic2vic

Quote: 





gibosi said:


> *2. Use a socket tester during periods in which many tubes are being compared and evaluated.*
> 
> ....
> If you are going to do a lot of tube swapping while strapping pins in the socket, I strongly recommend the use of a socket tester like the one below.
> ...


 
   
  It's weeks that I'm continuously looking for something like this on eBay, but it seems that only 9-pins socket savers exist. 
	

	
	
		
		

		
			




  Are you aware of ANY eBay seller selling these adapters/savers and shipping to Europe?


----------



## Acapella11

Quote: 





gibosi said:


> *2. Use a socket tester during periods in which many tubes are being compared and evaluated.*
> 
> ....
> If you are going to do a lot of tube swapping while strapping pins in the socket, I strongly recommend the use of a socket tester like the one below.
> ...


 
   
  What a cool item gibosi. I will put that on my shortlist. Cheers.


----------



## gibosi

Quote: 





vic2vic said:


> It's weeks that I'm continuously looking for something like this on eBay, but it seems that only 9-pins socket savers exist.
> 
> 
> 
> ...


 
   
  I too looked for these on eBay, but couldn't find anything....
   
  I bought mine from Leeds Radio located in Brooklyn, NY:
   
  http://leedsradio.com/
   
  And they will ship internationally.


----------



## john57

On some of the LD products you make to make sure that you have enough room to insert the socket saver because of the rings.


----------



## zedmeco

http://www.ebay.co.uk/itm/2-x-ROHREN-TUNG-SOL-6485-NEU-OVP-6AH6-/261150136993?_trksid=p5197.m1992&_trkparms=aid%3D111000%26algo%3DREC.CURRENT%26ao%3D1%26asc%3D14%26meid%3D7384774600389803262%26pid%3D100015%26prg%3D1006%26rk%3D1%26sd%3D261150136993%26
   
  I just got these delivered! they look quite substantial but I haven't plugged them in yet and reading your comments about the damage done to the pin sockets i am now afraid to stick the wire...but I am itching to hear these babies to see if they really are as good as you all say they are! i was thinking, could i use a slightly thicker gauge of fuse wire to wrap around the pin a few times, then pass it along and then a few wraps around the other pin, perhaps a little blob of solder to keep the whole thing sweet? how much current is actually going to pass through this wire? any thought?


----------



## gibosi

Quote: 





zedmeco said:


> http://www.ebay.co.uk/itm/2-x-ROHREN-TUNG-SOL-6485-NEU-OVP-6AH6-/261150136993?_trksid=p5197.m1992&_trkparms=aid%3D111000%26algo%3DREC.CURRENT%26ao%3D1%26asc%3D14%26meid%3D7384774600389803262%26pid%3D100015%26prg%3D1006%26rk%3D1%26sd%3D261150136993%26
> 
> I just got these delivered! they look quite substantial but I haven't plugged them in yet and reading your comments about the damage done to the pin sockets i am now afraid to stick the wire...but I am itching to hear these babies to see if they really are as good as you all say they are! i was thinking, could i use a slightly thicker gauge of fuse wire to wrap around the pin a few times, then pass it along and then a few wraps around the other pin, perhaps a little blob of solder to keep the whole thing sweet? how much current is actually going to pass through this wire? any thought?


 
   
  As long as you use stranded wire, everything will be fine. I was shoving tubes in and out of my LD like a mad man and using solid core wire. It takes time and a lot of rolling to do any real damage. So by all means, use 26 gauge, or smaller stranded wire, and enjoy them.
   
  Oh, there is very little current passing through this wire, measured in milliamps at most. A very tiny wire is more than sufficient.
   
  I have two comments regarding your suggested alternative. First, it is very difficult to solder wire to tube pins. You want the surface of the tube pin right up against the glass base to be very clean and shiny. You will likely have to use sandpaper or a sharp knife to get down to shiny metal. Otherwise, the solder will not adhere properly. And second, if you use a "slightly thicker wire", the thickness of the wire will prevent the tube from sitting properly in the socket and the pins will not make good contact.
   
  That said, if you are willing to put in the necessary time and effort, soldering a wire is the best solution, IMHO. And if you are willing, I would recommend 30 gauge solid core wire.
   

   
  I did not try to solder this connection, but as you can see, 30 gauge wire is tiny enough not to cause any problems when the tube is inserted into the socket.
   
  But again, they have just arrived! Don't deny yourself!  Use a little piece of small stranded wire and enjoy. 
   
  And then, if you end up loving these TS 6485, it will be worth the extra time and effort to figure out how to get a good soldered wire connection.


----------



## inphu510n

Gibosi's approach is excellent.
  Use the socket wire mod until you find a tube you really like and then solder the pins together.
  I used 26GA stranded copper wire, probably way thicker than was needed. I haven't posted pics of it but I will eventually. I just have a lot going on right now.
  I have some even thinner gauge stranded wire that I'm going to try using on my 6AV6 tubes.
   
  Once I get pics posted and if it looks like acceptable work I can definitely offer to do the soldering for people. For a small fee of course 
  Looking at the LD boards it really wouldn't be that hard to pull them off and replace them. It's just a matter of finding the exact (or higher quality) tube sockets that will fit.
   
  Honestly though, I'd like to sketch something up and have an adapter made for our purposes. I've been trying to think about the mechanics of making an adapter that would allow for several configurations but I haven't spent enough time thinking about it to come to a useful conclusion. The 2-7 pin mod is obviously easy to achieve though I'm unsure what manufacturing costs would be like. This is really small batch, niche stuff here. Having never had anything put into manufacturing, it would be a good exercise because there are other ideas I'd like to have produced for use in the world.


----------



## vic2vic

Quote: 





gibosi said:


> http://leedsradio.com/
> 
> And they will ship internationally.


 
  $50-$60 for delivery cost


----------



## gibosi

Quote: 





john57 said:


> On some of the LD products you make to make sure that you have enough room to insert the socket saver because of the rings.


 
   
  Perhaps this picture will help people determine if it will fit in their LD....


----------



## zedmeco

well, that was disappointing. I did the wire mod like you have shown in the diagram, the settings on the amp are for standard ef95 tubes, once i turned the amp on i could hear a kind of crackling sound, just once from each headphone, when i put them on, immediately there were microphonics, the slightest touch anywhere near the amp was picked up, the open mic effect.  didn't really get passed that to be honest. the good news though, I did win the bid on the sylvania gold brands, bloody expensive but so rare now there cant be many more of them out there.


----------



## gibosi

Quote: 





vic2vic said:


> $50-$60 for delivery cost


 
   
  I am very surprised! 
   
  Probably because most US vendors prefer to use Express mail because it provides for tracking which makes it easier to resolve shipping problems. But I had no idea international Express mail was this expensive.... 
   
  Leeds Radio has been in business since 1923 and specializes in vintage electrical parts manufactured before 1968.
   
  http://www.nytimes.com/2011/11/20/nyregion/leeds-radio-is-a-haven-for-lovers-of-all-things-analog.html?_r=0
   
  There must be similar places in Europe.... Good luck!


----------



## gibosi

Quote: 





zedmeco said:


> well, that was disappointing. I did the wire mod like you have shown in the diagram, the settings on the amp are for standard ef95 tubes, once i turned the amp on i could hear a kind of crackling sound, just once from each headphone, when i put them on, immediately there were microphonics, the slightest touch anywhere near the amp was picked up, the open mic effect.  didn't really get passed that to be honest. the good news though, I did win the bid on the sylvania gold brands, bloody expensive but so rare now there cant be many more of them out there.


 
   
  The crackling sound likely indicates that the connection is poor. And with poor connections I have had tubes go microphonic that normally have no microphonics. You used a small piece of stranded wire in the socket?  Are you sure you have pins 2 and 7 connected? Since the sockets are a mirror image of the tube, it is easy to make a mistake. I would recommend you double check everything and try again.


----------



## zedmeco

hi, i used 5amp fuse wire, wrapped it about three times around pin 2 keeping back about a centimetre over hang, then onto pin 7, three wraps around that and then back to pin 2, two more wraps and then i twisted together the the two ends of the wire, a couple more wraps around pin 2, and then cut off the excess. do you think there would be a bad connection? i am keen to hear these tubes but my fear of damage to my amp is back. 
   
  just tried it again, i scraped the bottom of the pins, and then used a slightly thicker piece of fuse wire, same result. never mind, i must just have two dud tubes.


----------



## gibosi

Quote: 





zedmeco said:


> hi, i used 5amp fuse wire, wrapped it about three times around pin 2 keeping back about a centimetre over hang, then onto pin 7, three wraps around that and then back to pin 2, two more wraps and then i twisted together the the two ends of the wire, a couple more wraps around pin 2, and then cut off the excess. do you think there would be a bad connection? i am keen to hear these tubes but my fear of damage to my amp is back.


 
  From your description, it sounds to me like there is way too much wire wrapped around the pins. When you attempt to insert the tube, all this wire is very likely preventing the tube from seating properly into the socket and preventing the pins from making a good connection, especially pins 2 and 7. Click on the picture I posted above with 30 gauge wire. Notice that I have only one wrap on both pins and I am using a very small wire.... In this way, even though I used no solder, the tube seated properly, the pins were inserted deeply and the resulting connections were very good.
   
  Again, please trust me on this...  To begin, get some 26 gauge or smaller stranded wire and drop one end into the hole for pin 2 and the other into the hole for pin 7. And then, if you really like them, you can take the time to research and experiment to figure out how to mod the tube with a soldered wire. Cheers.


----------



## mordy

Hi Z,
   
  I was also apprehensive about the wire strap mod, but it is really very simple. I am sure that you have a set of earphones or iPod wire somewhere that don't work. Cut off the wire, take a scissors or a little knife and peel back all the braiding and other stuff, and you should have a couple of very thin insulated stranded wires in there.
  Cut off an little piece (an inch or 2-3 cm). Then remove the colored plastic sheath from the wire with your nails or a wire cutter  or pliers, stripping one end about the length of one of the pins on the tube. Bend the wire 90 degrees, put it in the socket (make sure amp is off) and mark off where you should strip the other end of the wire. Cut off the excess wire, and strip the other end. Bend the wire 90 degrees. What you have now should look like a staple with two bare ends and insulation in the middle. Twist together the bare wire ends with you fingers. Then drop into socket holes 2&7 with a tweezers or small pliers. You may need to push a little with a tool or with your fingers to get the wire strap into the right place.(Again, make sure that you have the right location of the holes.)
  Take the tube and push in gently, watching that the wire stays in the holes. If there is crackling or no sound, move the tube around a little to make better contact.
  So far we have not heard of any damage to the amp by trying these mods, even when mistakes were made.


----------



## hypnos1

Quote: 





zedmeco said:


> hi, i used 5amp fuse wire, wrapped it about three times around pin 2 keeping back about a centimetre over hang, then onto pin 7, three wraps around that and then back to pin 2, two more wraps and then i twisted together the the two ends of the wire, a couple more wraps around pin 2, and then cut off the excess. do you think there would be a bad connection? i am keen to hear these tubes but my fear of damage to my amp is back.
> 
> just tried it again, i scraped the bottom of the pins, and then used a slightly thicker piece of fuse wire, same result. never mind, i must just have two dud tubes.


 
   
  Hi there z,
   
  You must be feeling rather frustrated/disappointed by now but may I add my support for mordy's advice re using the wire mod in the sockets. Read all the info on this via the many posts - there is also a diagram by audiofanboy on page 59 - and be sure to connect the correct holes in the socket and use thin stranded wire. It really is the easiest way to begin with.
   
  You would have to be really unlucky for both tubes to be dud, but there is always the slightest possibility that could be the case, viz a couple of posts methinks have mentioned faulty 6485s and 1 of the first 3 (of ten) I have tried from the same source proved dud...
   
  So please persevere - the sound that comes from these tubes is AMAZING and well worth a bit of a struggle.
   
  Good luck


----------



## Acapella11

Hi Z,
   
 Socket wire mod ftw! Don't worry about the socket if you are using fine stranded wire. I have used an old wire from a an old internal PC connector, with 3 strands, black, red, yellow, kind of like the fan wires. The only disadvantage is that you need to fix it occasionally after pulling out the tube. I would also recommend to make a shorter jumper in order to connect pins 6 and 7 on the socket for the EF91/92 setting. This way, you never ever need to worry about which setting your LD jumper is set to (which is the EF95 setting). Just do it 
  
 Burning in at the moment a fresh Tung Sol 6BE6 tube. Sounds good so far 
  
 Recently, I had a few changes in my gear, so I have to get used to the sound. I have to go back to reference tubes in order to reorient myself plus I am comparing old and new gear. Interesting for me, not perfect to compare tubes, but I am on it.


----------



## mordy

About faulty tubes:
   
  Before writing off the tube (unless the silver inside turned to WHITE, which means that the tube is really dead - vacuum lost), you must try this:
   
  Take a little pocket knife or anything similar with a small blade (does not have to be sharp), and carefully scrape the pins gently until they become more shiny.
   
  Recently I had a TS tube suddenly stop working. The pins did not look corroded, just a little burnished. Tried the tube in another socket, moved it around in the socket - nothing helped. Then  I remembered the scraping trick. The tube came back to life and has functioned fine since then.
   
   
  This has helped for crackling tubes as well.


----------



## zedmeco

thanks for all the advice everyone, this morning i was compelled to try again, i scraped all the pins, got some fresh wire from an old mini jack to phono lead, stripped a 2 inch section of it to bare wire strands, took about half of the strands and twisted them together making a very thin piece of wire. i then connected pins 2 and 7 together taking care only to make one twist around each pin and then cutting off the excess wire right up to the pin. the connection is almost flush to the glass, maybe less then a millimetre up the pin. i pressed them home into the socket, giving a little jiggle as they went in and seated tight. headphones on, no crackle! result, still microphonic but less so, probably a result of the scraping! got a track on and listening now, great separation of all the sounds, really nice sound stage. seems a flat response to me, no spurious frequency enhancement, a good thing as i use the set up for music production. but then half way through, i could hear a high frequency, almost like a chime in the back ground. this lead to the crackle which started to get louder, at which point i switched the amp off. these are clearly superior tube, but i seem to be unable to get a good connection and the amp got a lot hotter a lot quicker too, less then 5 minutes and the whole amp was hot.  
   
  i love my amp, champagne audio for lemonade money. i listen/write music all the time, i can put in 8 hour stretches and the sound is not fatiguing in any way, my butt gets tried before my ears! i will keep following this wonderful thread but i don't think i am going to try them again. thanks once again z


----------



## gibosi

Quote: 





zedmeco said:


> thanks for all the advice everyone, this morning i was compelled to try again, i scraped all the pins, got some fresh wire from an old mini jack to phono lead, stripped a 2 inch section of it to bare wire strands, took about half of the strands and twisted them together making a very thin piece of wire. i then connected pins 2 and 7 together taking care only to make one twist around each pin and then cutting off the excess wire right up to the pin. the connection is almost flush to the glass, maybe less then a millimetre up the pin. i pressed them home into the socket, giving a little jiggle as they went in and seated tight. headphones on, no crackle! result, still microphonic but less so, probably a result of the scraping! got a track on and listening now, great separation of all the sounds, really nice sound stage. seems a flat response to me, no spurious frequency enhancement, a good thing as i use the set up for music production. but then half way through, i could hear a high frequency, almost like a chime in the back ground. this lead to the crackle which started to get louder, at which point i switched the amp off. these are clearly superior tube, but i seem to be unable to get a good connection and the amp got a lot hotter a lot quicker too, less then 5 minutes and the whole amp was hot.
> 
> i love my amp, champagne audio for lemonade money. i listen/write music all the time, i can put in 8 hour stretches and the sound is not fatiguing in any way, my butt gets tried before my ears! i will keep following this wonderful thread but i don't think i am going to try them again. thanks once again z


 
   
  A couple things come to mind. First, the wire connecting pins 2 and 7 had no insulation? If so, bare wire may well have been in contact with the metal surrounding the socket center hole, and this is likely not good. And two, when I wrapped solid core wire around the pins, I could count on it to stay in place. Stranded wire wrapped around the pins can easily come unraveled. Thus, I am guessing you did not have a good connection.....
   
  With all due respect, you still have not tried the one solution that all of us have suggested, that is, putting a small piece of stranded wire into socket pin holes 2 and 7. If you do this (but you need to leave some insulation on the wire where it could come in contact with the metal surrounding the socket center hole), you will most certainly have a good electrical connection. And then you can finally relax and check out these tubes.  And then, if you decide you really like them, solder a similar piece of wire onto the pins and you won't ever have to worry about this again...  
   
  Oh, are your Sylvania gold brands 6AU6 by chance?


----------



## zedmeco

hi, i did try the wire in the socket mod last night, i couldn't find any wire thin enough so i used a bit of electrical tape over the centre of the socket, i think i am going to hunt something really thin and get the soldering iron out! they did sound nice i must confess.
  i just won the bid and still waiting for the Sylvania Gold GB 5654 6AK5 EF95 JAN, these are supposed to be very special, i will let you know. wish me luck, i am going i am for the soldering iron!


----------



## zedmeco

i found some old computer interconnect, the long thin ribbon type, cut off one little wire, cut it to size, stripped away the insulation at the ends, put a bit of solder around the wire ends, the insulation fit exactly between the pins, i bent the wire so it just cupped the pin, applied the solder, a firm connection, put the tubes into the socket, no crackle but still the microphonics. i had a listen to this,  http://youtu.be/qt9p9ZqI-yI which as a piece of music is fantastically produced. the tubes sounded fab, there is no denying it, but half way through, the crackling started again, i moved the tube in the socket to the accompaniment of some very unhappy sounds. i whipped them out, cut a fresh pair of this very thin wire, put the ends into the sockets, carefully inserted the tube, same story as before. no crackle again but still terrible microphonics. the crackle came back in after about 3 minutes, during which time, everything got very hot. i think they do work and they do sound good, but i don't think the amp is too happy with them, the tolerances are not the same. i stuck the voskhod back in, i must tell you, this is a good sound. fantastic sound stage, deep, controlled bass, amazing detail in the mid and hi ranges, and i don't have the feeling the amp is going to blow! i think the beautiful thing about the amp is we have the ability to customise the sound with our tube selections, and there are many different flavours to sample, but we all have a different requirement, i need the sound to be flat with no coloration, so my mixes will sound good on other peoples equipment, with everything in balance, if a tube gives more bass, then when i am mixing, i will add less bass, and when you listen to it, it will be light in the bass. anyhow, thanks once again, for now, i am going to stick with the ef95's. z


----------



## MIKELAP

Hi,zedmeco do you have music on sound cloud possibly electronic, i remember that icon from somewhere !


----------



## gibosi

Quote: 





> Originally Posted by *zedmeco* /img/forum/go_quote.gif
> 
> the tubes sounded fab, there is no denying it, but half way through, the crackling started again.....


 
   
  You know, I am beginning to think that it may well be the tubes and not your strapping technique....
   
  Each time you tried, "half way through" they started to crackle. So you turn the amp on, everything sounds good, but "half way through", or once the tubes reach their normal operating temperature, they crap out. Maybe one or both of these tubes are defective. Of course the only way to know for sure is for you to try with another set of tubes! 
   
  But I would not be surprised if you decide enough is enough...


----------



## MIKELAP

Good thing i got the tube rolling thread its like coming home man its bad on the other threads, bickering ,complaining ,personnal attacks,WOW. Breathe in breathe out br...............


----------



## mordy

Trying something different now - since both channels on the Little Dot MkIII are completely independent of each other, I am running two different tubes at the same time, using a mono recording, and using the balance control on my receiver to switch between the right or left speaker.
   
  The tubes are TS 6AH6WA and GE Tektronix 4825A/6AU6A. It's like mix and match in a candy store; both are great tubes with a slightly different flavor. I could try to describe the differences but they are very minor, and together they sound wonderful.  What's the difference in flavor between a light green and dark green jelly bean? Who cares? (If someone stopped by and listened I don't think that they could tell that I am using two different tubes.)
   
  (OK - critical listening reveals that the GE is a little more mellow and not as bright in the treble. The GE goes a little lower but the TS is a little more detailed. Listening to an old 78 mono recording the only real difference is that the surface noise is more audible with the TS tube. But if you are just enjoying the music you won't notice - these tubes are so similar sounding.)
   
  It seems to me that you could audition different classes of tubes at the same time, just being very careful to use the right strap and jumper settings. On order are some triode and diode/triode tubes.
  We'll see.....


----------



## Johnnysound

Quote: 





hypnos1 said:


> Hi fellow newcomer to this forum.
> 
> Re. your interest in the Senn HD650, may I say that I have been overwhelmed by the sound (or should I say "sonic experience") of these when fed by the amazing MKiv SE - and so, I should imagine, the MKIII. It seems to me they fulfil pretty much all the criteria you mentioned, assuming a good source...I must admit I have probably helped things along by replacing the stock cable with one I made up using 8-stranded pure silver cable, but the stock is still pretty good!
> 
> ...


 
  Thank you for your welcome and your advice, hypnos1. I have no doubt the Senn HD650 are at another level...closer to "audio nirvana" perhaps.  Very expensive, however. For the moment, I'll try the Tung Sols, any good dealer you can suggest ?


----------



## gibosi

Yesterday, I reached a small milestone in my "headfi" life. I can no longer say "old ears and cheap gear", as I have received new headphones, Hifiman HE-300. <I am wearing a very huge grin> lol
   
  While certainly nowhere near the same league as the HE-500s or the Senn 650s, they are a significant upgrade from my $50 cheap budget headphones, so I can no longer say I have "cheap gear". But I am a little sad.... "old ears and mid-fi gear" just doesn't have quite the same ring to it. lol
   
  As you would expect, I am getting used to a whole new sound, a much better sound, but a different sound. For now, I need to spend some quality time with my current reference tubes, the TS 6485, GE 4825A/6AU6A, Sylvania 8532W/6J4 and Sylvania 6AQ6, to reorient my mind and ears, before I can begin to evaluate any new tubes.
   
  Predictably, my budget phones were tuned to a more consumer-oriented sound signature, with boosted bass and rolled-off treble, whereas, the HE-300s have a much more balanced sound. The first difference I have noticed is how different the 6AQ6 tubes sound. Listening through my old phones, with their rolled off treble, the 6AQ6s were on the verge of becoming my favorite tubes. Now, with the HE-300s, their treble sounds a bit too bright. However, I am still getting used to these phones. And I am told that the sound of dynamic headphones will likely change somewhat during the first month or so of use. So I have put the 6AQ6s aside for now and installed the 8532Ws. Much better. 
   
  Unfortunately, I am still trying to figure out how to securely strap pins 2 and 7 using my new socket testers, so I haven't been able to listen to the 6485s or the 8425As.
   

   
  While the hookup wire easily fits into the space between the test point and the phenolic housing, it has proven difficult to obtain a secure and tight fit. My current thinking is to purchase some tiny brass sheet metal screws and screw them into the space between the test point and the housing. In this way, I hope to be able to secure the hookup wire tightly against the test point. But if anyone has another suggestion, I am all ears. 
   
  Oh and this is my 200th post!


----------



## Audiofanboy

Good god, I leave on holiday for 3 days, and I come back here to a full 30 posts! This thread used to be less active and dynamic lol!
   
  Anyway, like what everyone else said, the pin 2&7 wire mod seems to work quite fine with stranded wire (if anything my 26 AWG wire with insulation is pretty huge compared to what most of you have used, and it worked great Every time I used it so...), and it still appears to me like the easiest, best and most versatile solution for pin strapping, including strapping pins 6&7 like acapella said. I'd probably have trouble using socket savers on my IV SE with the brass structures around the tubes...
   
  This being said, the Next step in "modding" those amp would most likely involve some kind of socket saver hacking, so I'll be closely following gibosi's adventures on that front lol. If anyone bumps into 8-pin or 9-pin to 7-pin adapter (keep looking on ebay but can't find a pair of those that clearly states that it does that), I would also be Very interested.
   
  Zedmeco, those TS 6485 are from the same seller I bought them from. They're awesome tubes, but the first pair I got had some severely oxidized pins. Both tubes I cleaned worked fine and sounded great from my first attempt at plugging them with pins 2&7 strapped, but one tube never made sound again after one day... My second pair has been working great for a week or so now and didn't require any cleaning (I had pretty much insisted I did not want another tube with bright green pins, and my plea was answered).
   
  So, I'd suggest -if you haven't done so- a thorough cleaning of the tube pins (like both chemical and mechanical cleaning, i.e. deoxit + knife or sand paper), since that might help considerably with making good contact. Using good quality (stranded) wire to strap pins is the only other piece of advice I can give you, like everyone else said.
   
  Still waiting on my replacement 8532W... No new tubes for three weeks in a row, I feeling a bit of withdrawal here lol...


----------



## Acapella11

Congratulations *gibosi* to your new your headphone. I think this was a very good choice. Enjoy it and discover all the new good sound. The upgrade to better gear would never be as much fun if we wouldn't take intermediate steps... 
   
  I am also in the situation to use new gear, so we both have to get used to our new toys 
   
  Quote:  





> Good thing i got the tube rolling thread its like coming home man its bad on the other threads, bickering ,complaining ,personnal attacks,WOW. Breathe in breathe out br...............


 
   
   
  +1, the way we shape it, we love it 
   
  Sorry for this long post, but I had to rectify some things and give value to some new findings.
   
*TS 6485 (6AH6) vs. GE 8425 (6AU6)* Update:
 I hear the differences more using my 6H30P-EV than 6N6P-IR power tubes, which are a bit warmer themselves. Hence, these notes are taken while using the 6H30P-EV power tubes.
 _Warmth_: The 6485 sound more open, a bit sparklier, the 8425 a bit mellower and warmer. I think ability to hear differences sometimes also depends on your personal form. _Sorry, if I confused anyone_ .
 _Treble_: Due to the more open, airy sound, the TS 6485 give the impression of more detail and space.
 _Stage_: They also have a slightly better instrument separation, which goes along with a bit larger stage.
 _Bass_: Both basses are satisfactory to me from the level of impact and punch. In comparison, the 8425 has a deeper bass, "rolls" more. Also, the bass has greater presence in the representation.
   
  There is not a world between them but I found my preference again for the TS 6485 (6AH6) 
   
  I also have had a closer look to the* Tung Sol 6BE6 *and to be fair, the only disadvantage with using this tube is the lower gain compared to other ‘new’ tubes. Else, I would highly recommend to have a listen to them.
   
  Because of the _seven grids_ used, the jumper setting has a relatively large impact on the sound:
   
_*EF91/EF92*_: Airy, open, spacious representation, neutral. Cleaner than the TS 6485. This is my preferred setting. Here, the tube signature is very close to the TS 6485.
_Treble_: Extended, refined, not bright. Well resolved. I prefer the 6BE6 here to the TS 6485.
_Mids_: Quite sweet, round, clean.
_Bass_: The weakest bass weight compared to the other settings. Still enough for me. The bass quality is very good, well articulated and punchy.
  Stage: Larger and wider than TS 6485.
  I have also used the CV4015, since I was anyway on the EF91/92 setting. Smaller stage, not as deep, not as wide. Signature similar, sound not as clean and refined. Slightly coloured towards warm. The 6BE6 sounds more organized and accurate.
   
  Because of their black background, these tubes are ideal for detail lovers.
   
_*EF95*_* (floating grids)*: More bass weight, more deep bass, but slightly lesser quality, warmer, darker than the EF91/92 setting. You trade in some of the open airyness. Depending on preference, this more bassy setting could be the one
   
_*Pin 2-7 strap*_: This must be the bass head setting. Maximum bass weight, weakest treble presence. Surprisingly, still extended and one could consider to live with it, kind of the LCD headphone way, if you have tried that before. Guitars sound crunchy but generally mids are more recessed. A bit dynamic compressed sound for my ears or too frequency spectrum shifted to lower frequencies.
   
  The relative differences are similar with the* Sylvania JAN 5750*, even though I did not explicitly test this again.
  The Tung Sol 6BE6 sounds for me superior to the Sylvania, not by a huge amount, but still, because the the Tung Sol sounds more open and airy, slightly louder and a bit more detailed.
   
  So, I am using the EF91/92 setting as we speak, makes it also easier for every user. One problem while comparing 6BE6 tubes to the rest of the 'new' tubes is that they are not as loud as these, and adjusting the sound obviously also changes the sound impression if not perfectly matched. This is a quite common issue when comparing different gear but it means that we have to take these impressions with a grain of salt.
   

   
  Label: 6BE6, 3223501 (the one is a bit smeared out). This would mean the tube is from week one in 1935^^ or I am misinterpreting something...


----------



## Audiofanboy

Quote: 





acapella11 said:


> Congratulations *gibosi* to your new your headphone. I think this was a very good choice. Enjoy it and discover all the new good sound. The upgrade to better gear would never be as much fun if we wouldn't take intermediate steps...
> 
> I am also in the situation to use new gear, so we both have to get used to our new toys
> 
> ... 
   
   
  About the 6BE6 pin layout, it just occurred to me that since the last grid (grid 5 similar to grid 3 in a pentode) is hardwired to the cathode on the same pin 2, the pin 2&7 mod is essentially pointless, apart from its experimental value of course, but it's not necessary per se, as the by-the-book way to strap that type of tube would be exactly what you did using the EF92 jumpers.
   
  Just my 2 cents, it might explain why the tube sounds even weirder with the wire mod than it does leaving one grid floating, as tying that grid to the cathode might actually lead it to play a role in the tube (for instance, I'd read an example where strapping grids differently made the tube a current trinkler, letting only a little bit of current go through, making sound quite different than normal).


----------



## mordy

Dear A11,
   
  It amazes me that we get the same listening impressions although our equipment is totally different. A couple of different quotes comparing the Tung Sol 5685/6AH6WA and GE 4825/6AU6 tubes. (My remarks from post 1188 above are in jelly bean green colors)
   
  TS 6485 give the impression of more detail and space  - the TS is a little more detailed
  In comparison, the 8425 has a deeper bass - The GE goes a little lower 
   
  Regarding the "errant" Tung Sol date: TS had several factories. Some of the tubes I have seen have either a 3 or 7 factory number listed.
  Thus 3223501 refers to the EIA  (Electronics Industry Association)  number 322 assigned to Tung Sol. 3 is the factory. We are left with 501 which would lend itself to the first week of 1950. (According to the Tube Museum site the first tubes 6BE6 were made in 1946.)
   
  About comparisons: Listening to a set of Tung Sol 6676 (6CB6/6CJ6) - this is definitively an upgrade over the EF95 tubes. The presentation is crisp and fairly detailed with a very punchy low end. However, with the exception of the punchy bass, the sound is more solid state (ss) like and a little dull sounding (lacking in microdynamics?) If I did not have the superior 6AH6/6AU6 tubes I would have more or less liked these tubes, but now I don't.
   
  About the pin 2-7 strap: I did notice that the little stranded wires at the ends of the strap are thinning out from rolling different tubes (no effect on sound). What happens if a little piece of wire breaks off and falls into the socket pin hole? Could there be any ill effects?
   
  Cheers,


----------



## MIKELAP

Congrats gibosi on your new HE300 they are pretty nice so nice that they deserve a picture let us know how they sound .


----------



## Acapella11

Quote: 





mordy said:


> It amazes me that we get the same listening impressions although our equipment is totally different. A couple of different quotes comparing the Tung Sol 5685/6AH6WA and GE 4825/6AU6 tubes. (My remarks from post 1188 above are in jelly bean green colors)
> 
> TS 6485 give the impression of more detail and space  - the TS is a little more detailed
> In comparison, the 8425 has a deeper bass - The GE goes a little lower


 
   
   
  Great, isn't it =)
   
  Quote: 





audiofanboy said:


> About the 6BE6 pin layout, it just occurred to me that since the last grid (grid 5 similar to grid 3 in a pentode) is hardwired to the cathode on the same pin 2, the pin 2&7 mod is essentially pointless, apart from its experimental value of course, but it's not necessary per se, as the by-the-book way to strap that type of tube would be exactly what you did using the EF92 jumpers.
> 
> Just my 2 cents, it might explain why the tube sounds even weirder with the wire mod than it does leaving one grid floating, as tying that grid to the cathode might actually lead it to play a role in the tube (for instance, I'd read an example where strapping grids differently made the tube a current trinkler, letting only a little bit of current go through, making sound quite different than normal).


 
   
  Makes sense. Cheers.


----------



## hypnos1

Quote: 





johnnysound said:


> Thank you for your welcome and your advice, hypnos1. I have no doubt the Senn HD650 are at another level...closer to "audio nirvana" perhaps.  Very expensive, however. For the moment, I'll try the Tung Sols, any good dealer you can suggest ?


 
  Hi there again J,
   
  I got my 6485s, as did a couple of others here, from an ebayer in Germany - german-tubes - with very good deals in multiple units. It seems Audiofanboy requested tubes with CLEAN pins  - good idea - or else make sure you clean them thoroughly yourself (please excuse me if I'm "telling Grandma how to suck eggs"!!)...
  Stateside on ebay.com it seems on offer are 5 units for $15.99 - also an excellent price for such marvellous tubes.Go buy , whichever applies...
   
  I sincerely hope you manage to acquire some HD650s - if you're lucky perhaps even second-hand? I wish you all the best anyways.
   
  Good luck with the 6485s also...


----------



## mordy

Have been comparing my tubes to the current reference TS 6AH6/GE 6AU6 tubes mentioned above.
   
  Currently I am listening to a pair of RCA 1964 6AU6 tubes made for Bogen amplifiers. These tubes grow on you. They are not so much in your face as the the TS tubes and don't have the powerful punch in the bass nor their analytical preciseness.
  What they do have is a huge 3D sound stage with the music seemingly emanating from outside of the speakers on some recordings. The sound is startlingly realistic with a sweet and warm mid range and a tuneful strong bass. Highs are extended and clear and there is great clarity to the sound with very good imaging. Compared to the heft of the TS tubes there is a swiftness and lightness and musical quality to the sound.
   
  On the negative side, the RCAs are quite bright, but I do not have any difficulty compensating for it with the treble control on my receiver when listening through speakers. With my ATH AD-700 headphones plugged straight into the MkIII without any tone controls the sound is on the bright side, and the bass is a little flabby - seems that the speakers have a better control of the bass than my cans.
   
  If you buy these tubes right it is like going to the 99c store - you may want to give them a try....
   
  What Acapella writes about how a person's form may affect his perception of the sound is definitively true. However, another factor is also very important. During the day when all kinds of electric motors, appliances, fluorescent lights are on there is a lot of electric interference that may affect the sound. Listening at night when most of these things are off will usually improve the sound.
   
  In summary, these 6AU6 RCA tubes are sweet, lively and musical. They are more on the subtle side, and it takes a little time to get used to them - curious if somebody else tried them and what impression they have.


----------



## Acapella11

Hi Mordy,
  A large stage is always a treat for me. Sounds interesting. One thing, I thought about now comparing the two Tung Sol tubes, which have some similar traits: Is there a 'house sound'? Or is it just an urban myth?
   
   
 With respect to the Tung Sol 6BE6, which I highly recommend trying, and also other *6BE6, 6BY6 and 6CS6 tubes*: Something I did write only 'between the lines': If you do not consider higher gain important, because your can is easy enough to drive, then these 300 mA heater current tubes do not get as warm as 6AH6 450 mA tubes. I can easily touch them during operation. Also, you can use standard settings to operate them (EF91/92, EF95). This is not a concern for me but might be for others. So, they are easy enough to roll. Of course, I recommend as well trying the 6AH6 and 6AU6 tubes because they sound excellent as well and have higher gain if needed.


----------



## MIKELAP

Acapella11. the 6ah6 and 6au6 if i understand correctly only work with pin 2 and 7 strapped according to the chart right and those are the best sounding ones these days and the ones you just mentionned 6BE6 ects are better or worse  than the 6AU6 6AH6. Thanks.


----------



## Acapella11

Quote: 





mikelap said:


> Acapella11. the 6ah6 and 6au6 if i understand correctly only work with pin 2 and 7 strapped according to the chart right and those are the best sounding ones these days and the ones you just mentionned 6BE6 ects are better or worse  than the 6AU6 6AH6. Thanks.


 
   

 Mikelap,
 To be fair, me alone cannot really say that the TS 6BE6 would be better than the the TS 6485. A few people heard the 6485 and only me the 6BE6. From my point of view, the TS 6BE6 (EF91/92 setting) wouldn't be any worse than the TS 6485. If you have the suitable cans, I would imagine you could say that the TS 6BE6 is better, or you could say I don't hear a big difference. But they are differently loud, so it is more difficult to compare them than tubes of the same family.
   
  Yes, 6AU6 and 6AH6 use pin 2-7 strap. For 6BE6, I suggest the EF91/92 setting. Hear for yourself.


----------



## MIKELAP

Looking at  pairs of  6BE6 any  one pair you prefer in there
*5750 6BE6W Tube JAN USA GE Black Plates NOS *
*Match Code PAIR 6BE6 Tube GE USA NOS Converter EK90 Philco*
*[size=large]PAIR 6BE6 Tube Matsu****a TEN Corp Japan NOS Converter EK90[/size]*
*6BE6 Tube TUNG-SOL USA NIB Pentagrid Converter EK90 .*


----------



## mordy

Hi Mikelap,
   
  I would go for the Tung Sol first. If you like your GE tubes you may want to try these as well.
  Have not seen any raving reviews for Japanese tubes.
  Philco was a discount brand in tubes and I think always re-branded, so it may not be the best quality GE tubes in this case.


----------



## mordy

Hi A11,
   
  Have been thinking about "house sound." I don't think that there is a specific sound that distinguishes certain brands. It's like everything else in a product line. Some items are good, and some aren't. Nevertheless, a seat of the pants reaction to the question is that Tung Sol are solidly built tubes with very good bass, Sylvania and RCA have wide sound stages, and Mullards are warm and pleasant.
   
  Really, there are so many variables that you really have to judge each production type on it's own merits. Some brands have a better reputation than others and are thus safer to bet on when trying something out.
   
  Speaking about legends: Does anybody have any specific knowledge of the the effect of silicone tube damper rings on tube sound and performance?
   
   
  http://www.ebay.com/itm/44MM-vacuum-Tube-Damper-Silicon-Ring-fit-KT88-6550-KT66-Audio-Amp-DIY-part-20pcs-/261094075028?pt=Vintage_Electronics_R2&hash=item3cca6b6a94
   
  Happy tube rolling!


----------



## Acapella11

Quote: 





mikelap said:


> Looking at  pairs of  6BE6 any  one pair you prefer in there
> *5750 6BE6W Tube JAN USA GE Black Plates NOS *
> *Match Code PAIR 6BE6 Tube GE USA NOS Converter EK90 Philco*
> *[size=large]PAIR 6BE6 Tube Matsu****a TEN Corp Japan NOS Converter EK90[/size]*
> *6BE6 Tube TUNG-SOL USA NIB Pentagrid Converter EK90 .*


 

 Hi Mikelap, I agree with Mordy. Check out the Tung Sols, in my ears, they are better than the JAN 5750s. Enjoy them =)


----------



## MIKELAP

Thanks guys for your imput.


----------



## gibosi

Quote: 





mikelap said:


> Looking at  pairs of  6BE6 any  one pair you prefer in there
> *5750 6BE6W Tube JAN USA GE Black Plates NOS *
> *Match Code PAIR 6BE6 Tube GE USA NOS Converter EK90 Philco*
> *[size=large]PAIR 6BE6 Tube Matsu****a TEN Corp Japan NOS Converter EK90[/size]*
> *6BE6 Tube TUNG-SOL USA NIB Pentagrid Converter EK90 .*


 
   
  I have a pair of GE JG-5750/6BE6W with black plates dated 1959. (See the picture at the bottom of page 77). They sound pretty good to me, but since I am still getting used to my new headphones, I really can't say more than that. So I would agree that your best bet is probably the Tung Sols.


----------



## MIKELAP

Will order the Tung-Sol and probably some 6AU6WA if ever decide  to try those it would be nice to find an adaptor that could be modded but unfortunately i woulndt know where to start i am an ex machinist not an electrician but i can change a light bulbs dought!
	

	
	
		
		

		
			





 Thanks again.


----------



## gibosi

On eBay:
   
  An MK III for $60!!??  
   
  http://www.ebay.com/itm/171035236990?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649
   
  31 people have bought one! I wonder what they will get?


----------



## BobJS

-deleted-


----------



## mordy

My knee jerk reaction to $10 Little Dot MkIII is that "If it is too good to be true, it is too good to be true", but hey, you never know....
   
  Two months ago I saw a hard drive on EBay for less than half of the regular price from China. Feedback was 99.8% on some 800 sales and the seller had been selling on EBay for several years.
   
  Two days later I got an email from EBay that the site had been shut down - no reason given. I went back to look at the item. The feedback had tumbled overnight to 64% with some forty people screaming that they never got their merchandise.
   
  I contacted EBay and Pay Pal and luckily I got my money back in a few days.
   
  Should I bite on this offer?


----------



## mordy

Good Price and When do you shiped ?
 *Member id *coke-888  ( *Feedback Score Of* 250





) 
 May-08-13 21:19   NEW Little Dot MK III Headphone Tube Amplifier / Stereo Amplifier (#171035236990) US $9.90
   
  Here is another little gem: Somebody left positive feedback before he received the item; actually before it was shipped. (Note Chinese spelling error shiped)
   
  This is getting funner and funner......


----------



## john57

If you checked on the seller items for sale you would have noticed many items at the same price.


----------



## mordy

Another bargain: A $330 item for $10 as well....
  Caveat Emptor!
   
   
   
  http://www.ebay.com/itm/NEW-Matrix-mini-i-24bit-192kHz-Balanced-DAC-Remote-Control-/171035239407?pt=US_Wholesale_TV_Video_Home_Audio&hash=item27d27ea3ef


----------



## mab1376

says delivery is a "ePacket delivery from China" probably just gonna email you a coupon or something.


----------



## mordy

ePacket is something real. Basically, in order to stimulate buying in Hong Kong and China, the US post office made arrangements to allow overseas shipping from these places to tie into the USPS tracking and delivery system at low cost. The article below explains in more detail:
   
  http://shippingsidekick.com/news.wml?id=450
   
  Only one hitch: The weight limit is 2 kg (4.4 lb) for an ePacket. The LD MKIII weighs 3kg (6.6 lb)......


----------



## MIKELAP

Mordy i sent the infos to that company you gave me the link in China for the socket. Tried to make them understand what i need and if its possible to do, personnaly i dont know, any of you guys know if it possible to strap #2and#7 pin in the socket itself and is it worth it because are they many tubes that we could use that socket for. Sent them another message because i want to know the outside diamete of the socket. they didnt say in first email. Thanks for any imput you guys would have.


----------



## mordy

Did not know if this would be of interest to everybody, so I sent this info to Mikeleap. Since he posted about it, I am posting  the link:
   
  Regarding socket adapters: I contacted one of the Chinese EBay sellers and asked them directly. They replied that they could make them up but need to know which tubes they are intended for. This is beyond my scope, but perhaps you would be interested in this.
   
  From eBay 會員: happydiy 998 happyd_is5196qbzc@members.ebay.com.hk
   
  [size=10pt]"Hello,

 yes, we can make for you, it's better you tell us which model tube you are using, and which model tube you want to use to replace it, then we can made accordingly, and send you quotation as well,

 Looking forward to hearing from you soon,

 Best Regards,
 Vanessa[/size]
  
 [size=10pt] [size=10pt]- happydiy998[/size]"[/size]
 [size=10pt]  [/size]
 [size=10pt] http://www.ebay.com/itm/1x-5687-to-6N6-6N1-6N2-6N6-6N11-ECC88-E88CC-Vacuum-tube-adapter-socket-converter-/300886991695?ssPageName=ADME%3AX%3ARTQ%3AUS%3A1123&nma=true&si=w9e%252BENYg%252BmhB%252FT01UUyg40rmdVQ%253D&orig_cvip=true&rt=nc&_trksid=p2047675.l2557[/size]


----------



## gibosi

Quote: 





mordy said:


> Did not know if this would be of interest to everybody, so I sent this info to Mikeleap. Since he posted about it, I am posting  the link:
> 
> Regarding socket adapters: I contacted one of the Chinese EBay sellers and asked them directly. They replied that they could make them up but need to know which tubes they are intended for. This is beyond my scope, but perhaps you would be interested in this.
> 
> ...


 
   
  I think we can answer this question in a way that makes sense to them:
   
  "We are using an amp that uses 6AK5 and we want to replace it with 6AU6." 
   
  As pins 2 and 7 in the 6AK5 are internally strapped, they should understand that we want a custom socket that will strap these pins together so that the 6AU6 can be used.
   
  If you will send this text to them, let's see if they are willing to do this and if so, how much it would cost.
   
  Cheers
   
  Edit: Looking at their ad:
   
   
  "5687 to 6N6 vacuum tube adapter socket converter handmade tube socket converter
   
  if you choose this adapter, means you want to put your 5687  tube
   
  on the adapter to connect to the 6N6 amplifier socket"
   
  So their new ad would say:
   
   "6AU6 to 6AK5 vacuum tube adapter socket converter
   
  handmade tube socket converter
   
  if you choose this adapter, means you want to put your 6AU6  tube
   
  on the adapter to connect to the 6AK5 amplifier socket"


----------



## MIKELAP

Quote: 





gibosi said:


> I think we can answer this question in a way that makes sense to them:
> 
> "We are using an amp that uses 6AK5 and we want to replace it with 6AU6."
> 
> ...


 
   
   My request to you would be  to see if an adaptor could be made to accept 6AU6 tubes and possibly other tubes of the same genre this adaptor would be a 7pin male adaptor that would fit in a littledot mk3 amplifier and a 7 pin female adaptor on top to receive the 6au6a tubes or others of the same configuration. usually this amp does not natively accept these tubes only the EF92 AND EF 95 categories of tubes so to use the 6AU6 TUBES pin # 2 and pin #7must be strapped or liked with a wire for each channel We are looking for a way to achieve this with a socket that would be modified to accept these tubes just by inserting the modified socket . to recapitulate we need a 7pin male and female 7 pin adaptor socket  that fits in  the littledot mk3 sockets. one adaptor per channel the only thing i need to know is the exteriour diameter of the adaptor. Our male adaptor part would be shaped like the female end of your socket in picture enclosed . 
  THIS IS THE TEXT I SENT TO THEM IS IT OK .


----------



## gibosi

Quote: 





mikelap said:


> My request to you would be  to see if an adaptor could be made to accept 6AU6 tubes and possibly other tubes of the same genre this adaptor would be a 7pin male adaptor that would fit in a littledot mk3 amplifier and a 7 pin female adaptor on top to receive the 6au6a tubes or others of the same configuration. usually this amp does not natively accept these tubes only the EF92 AND EF 95 categories of tubes so to use the 6AU6 TUBES pin # 2 and pin #7must be strapped or liked with a wire for each channel We are looking for a way to achieve this with a socket that would be modified to accept these tubes just by inserting the modified socket . to recapitulate we need a 7pin male and female 7 pin adaptor socket  that fits in  the littledot mk3 sockets. one adaptor per channel the only thing i need to know is the exteriour diameter of the adaptor. Our male adaptor part would be shaped like the female end of your socket in picture enclosed .
> THIS IS THE TEXT I SENT TO THEM IS IT OK .


 
   
  Yes, this text should be fine. Even though you mention EF92 tubes, the fact that you clearly indicate that pins 2 and 7 need to be strapped should tell them that the converter needs to allow 6AU6 tubes to be plugged into a EF95 socket.  Let's see how they respond.


----------



## Johnnysound

Quote: 





hypnos1 said:


> Hi there again J,
> 
> I got my 6485s, as did a couple of others here, from an ebayer in Germany - german-tubes - with very good deals in multiple units. It seems Audiofanboy requested tubes with CLEAN pins  - good idea - or else make sure you clean them thoroughly yourself (please excuse me if I'm "telling Grandma how to suck eggs"!!)...
> Stateside on ebay.com it seems on offer are 5 units for $15.99 - also an excellent price for such marvellous tubes.Go buy , whichever applies...
> ...


 
  HI Hypnos1,  and many thanks for the tip, the TS 6485 are on its way (5 units for 15.99) looks like a really good price.  I do not live in the U.S., (Lima, Peru)  but a friend is coming in a few days.   You just do not find tubes here so easily, but looking really hard around old electronics stores you can find really nice NOS tubes at bargain prices ¡¡  What I will do with the tubes is to bring them to a veteran technician who happens to (still) have a tube tester, and ask him to select a "matched pair" from the five units.  Second, I will ask the man to test the tubes at full operational temperature for microphonics.  Then, I will have a "selected" pair of TS 6485.  Next step should be to solder a tiny, 30 awg solid wire between pins 2-7.  I agree with others in this forum that this is the best solution.  I know how to solder  and believe me, "clean" pins is not enough. You have to work very carefully the surface of the pins for a good solder joint, and it means completely removing the plating metal in that area. Second, the tips of the wire should be lightly "tinned" of course. Third, you have to apply just a tiny quantity of solder for a good joint, without compromising the pins connection.  All that in a very small space. It will not be easy, but I think I can do it.  Sorry about my ignorance, but I understand the 6485 is an EF95 tube, so I do not need to change any jumper settings, right ? 
   
  BTW, the Voshkods are near full burn in now, and I am  really impressed.  The sound is way better now.  Gone are my feelings about a problem in the mids.  The bass was excellent but now is just outstanding, deep, tight, precise.  The highs are super extended,  but perhaps the top advantage  of this tube is not in some particular areas but in its big, dynamic, transparent sound.  It is kind of ruthless.  With some kind of music,  or better said, with some not-so-good recordings (compressed or over equalised) the Voshkods may hit too hard,  but with good material they can sound positively _heavenly_  If you know what I mean. However, the pair I have become  kind of mildly microphonic at full temperature, and that bothers me a lot at very low volumes. Curiously, the effect  is not that significant  with headphones, but my recent testing was done with the LD MKIII as a preamp directly into two mono, 250 W SS NAD amps, with my big DCM bi amped towers and I can tell you this is a hard  test for tubes.  Of course headphones are much more revealing and transparent,  but in terms of soundstage, bass and dynamics  here you have  a room to fill, and in this "real world" situation the Voshkods simply sounded superior to the other two or three tubes I have.  As you can see, this will be a nice test for the 6485's.  I´ll let you know...kind regards,


----------



## inphu510n

I'd rather see a socket adapter that disconnects pins 5 & 6. I REALLY hate hacking pins off of perfectly good tubes. Especially just for experimenting with tubes I may or may not enjoy.
I'm sure if these guys can do what you're asking them to, they can surely just not include pins 5 & 6 in another custom adapter.


----------



## gibosi

Quote: 





johnnysound said:


> Sorry about my ignorance, but I understand the 6485 is an EF95 tube, so I do not need to change any jumper settings, right ?


 
   
  Yes, you are correct. Leave your amp in the EF95 setting, and once you have pins 2 and 7 of your 6485 soldered together, simply plug it in and enjoy.


----------



## gibosi

Quote: 





inphu510n said:


> I'd rather see a socket adapter that disconnects pins 5 & 6. I REALLY hate hacking pins off of perfectly good tubes. Especially just for experimenting with tubes I may or may not enjoy.
> I'm sure if these guys can do what you're asking them to, they can surely just not include pins 5 & 6 in another custom adapter.


 
   
  Well, I rather enjoy cutting pins off of tubes. lol.
   
  What I would like is one set of custom adapters with pins 2 and 7 connected, and another with pins 5 and 7 connected. With these, I could leave the amp in the EF95 setting and still be able to use every tube I have.


----------



## MIKELAP

Quote: 





gibosi said:


> Well, I rather enjoy cutting pins off of tubes. lol.
> 
> What I would like is one set of custom adapters with pins 2 and 7 connected, and another with pins 5 and 7 connected. With these, I could leave the amp in the EF95 setting and still be able to use every tube I have.


 
  Yes thats the main goal i guess . did not receive any feedback yet for the socket when i do will post there reply here and we will go from there.


----------



## MIKELAP

i guess those tubes could be used with the 6au6 the 6j4p, 6j4, 6136,6au6wa,6au6wc,7543.the more the merrier because modded sockets will come out to $16.50 each +shipping.the ones below it says different heating for the 4au6, hf94, and xf94. if you know of any other type that could be used with the modded socket be my guest.Thanks guys


----------



## gibosi

Quote: 





mikelap said:


> i guess those tubes could be used with the 6au6 the 6j4p, 6j4, 6136,6au6wa,6au6wc,7543.the more the merrier because modded sockets will come out to $16.50 each +shipping.the ones below it says different heating for the 4au6, hf94, and xf94. if you know of any other type that could be used with the modded socket be my guest.Thanks guys


 
   
  The European EF94 is identical to the American 6AU6. So if you want a Mullard or Valvo 6AU6, you might want to search for EF94, rather than 6AU6.
   
  And of course, these socket converters will allow you to use 6AH6/6485.
   
  However, be very careful about 6J4P and 6J4. The American 6J4 is a triode. You might remember that the Sylvania 8532W is a premium version of the 6J4. However, the 6J4P is a Russian EF94/6AU6. You might remember that I tried these (post 928 page 62) and found them to be very noisy. It appears that many of the eBay vendors are not able to differentiate between these, so there is a good bit of confusion out there.....
   
  $16.50 each, so two would be $33.00 plus about $7.00 to ship to the US... About $40.00 for a pair shipped to the US.... Not cheap, but it might be worth it in the long run....


----------



## MIKELAP

Quote: 





gibosi said:


> The European EF94 is identical to the American 6AU6. So if you want a Mullard or Valvo 6AU6, you might want to search for EF94, rather than 6AU6.
> 
> And of course, these socket converters will allow you to use 6AH6/6485.
> 
> ...


 
  its not that bad and those tubes if i remember sound good so its a hobby i rather spend it on that .on top of that these days might do something crazy very interested in new cans to go with the Conductor i got a month ago either the fostex th900 or th senns hd800 i would consider the LCD3 but theres no dealer here i  would listen mostly to classical, vocals, acoustic stuff i listened once to senns but ill go back a few more time to the store for more listening because i think the fostex are more like the Denons but more refined.and i also cant listen to the fostex either so might end up with the senns but not there yet. Exciting times.And by the way thank you for reminding about the 6j4 memory is something i have problems with sometimes .


----------



## Johnnysound

Quote: 





gibosi said:


> Yes, you are correct. Leave your amp in the EF95 setting, and once you have pins 2 and 7 of your 6485 soldered together, simply plug it in and enjoy.


 
  Thanks gibosi. In the end the most practical solution for swapping tubes are the custom adaptors you are looking for.  The chinese can make them for sure...it they see a market.    Please let me know about previous posts, some kind of "guide" regarding tubes requiring 2-7 or 5-7 strapping.  I understand it is a way of using the LDMKIII  default   EF95 setting with many different tubes.


----------



## gibosi

Quote: 





johnnysound said:


> Thanks gibosi. In the end the most practical solution for swapping tubes are the custom adaptors you are looking for.  The chinese can make them for sure...it they see a market.    Please let me know about previous posts, some kind of "guide" regarding tubes requiring 2-7 or 5-7 strapping.  I understand it is a way of using the LDMKIII  default   EF95 setting with many different tubes.


 
  Acapella11 has put together a chart with exactly the information you are looking for. Please see post 1154 on page 77.


----------



## gibosi

Recently, I have been listening exclusively to mutilated triodes, namely Sylvania 6AV6 and Sylvania 8532W/6J4. Both of these are very fine tubes, but the 8532 is a bit darker than the 6AV6.
   
  Hey, it feels rather lonely here in mutilated triode land!! Is anyone else listening to triodes????
   
  In the meantime, several more triodes have shown up in my mailbox:
   
  The CV5311, Mullards version of the 8532W/6J4.
   
   
   
  Mullard 6VA6. It is interesting that there is no Mullard shield printed on this tube. Moreover, the European designation, EBC91 is not printed on the tube. I wonder if these might have been manufactured exclusively for the American market?
   

   
  GE 6AV6 rebranded as EICO
   

   
  And I often see mentioned that RCA black plate 12AX7s are some of the best. So I thought why not get some RCA black plate 6AV6?
   

   
  And finally, a bit of a teaser... Audiofanboy thinks the 6AQ4/EC91 triode is worth checking out.....


----------



## hypnos1

Quote: 





johnnysound said:


> HI Hypnos1,  and many thanks for the tip, the TS 6485 are on its way (5 units for 15.99) looks like a really good price.  I do not live in the U.S., (Lima, Peru)  but a friend is coming in a few days.   You just do not find tubes here so easily, but looking really hard around old electronics stores you can find really nice NOS tubes at bargain prices ¡¡  What I will do with the tubes is to bring them to a veteran technician who happens to (still) have a tube tester, and ask him to select a "matched pair" from the five units.  Second, I will ask the man to test the tubes at full operational temperature for microphonics.  Then, I will have a "selected" pair of TS 6485.  Next step should be to solder a tiny, 30 awg solid wire between pins 2-7.  I agree with others in this forum that this is the best solution.  I know how to solder  and believe me, "clean" pins is not enough. You have to work very carefully the surface of the pins for a good solder joint, and it means completely removing the plating metal in that area. Second, the tips of the wire should be lightly "tinned" of course. Third, you have to apply just a tiny quantity of solder for a good joint, without compromising the pins connection.  All that in a very small space. It will not be easy, but I think I can do it.  Sorry about my ignorance, but I understand the 6485 is an EF95 tube, so I do not need to change any jumper settings, right ?
> 
> BTW, the Voshkods are near full burn in now, and I am  really impressed.  The sound is way better now.  Gone are my feelings about a problem in the mids.  The bass was excellent but now is just outstanding, deep, tight, precise.  The highs are super extended,  but perhaps the top advantage  of this tube is not in some particular areas but in its big, dynamic, transparent sound.  It is kind of ruthless.  With some kind of music,  or better said, with some not-so-good recordings (compressed or over equalised) the Voshkods may hit too hard,  but with good material they can sound positively _heavenly_  If you know what I mean. However, the pair I have become  kind of mildly microphonic at full temperature, and that bothers me a lot at very low volumes. Curiously, the effect  is not that significant  with headphones, but my recent testing was done with the LD MKIII as a preamp directly into two mono, 250 W SS NAD amps, with my big DCM bi amped towers and I can tell you this is a hard  test for tubes.  Of course headphones are much more revealing and transparent,  but in terms of soundstage, bass and dynamics  here you have  a room to fill, and in this "real world" situation the Voshkods simply sounded superior to the other two or three tubes I have.  As you can see, this will be a nice test for the 6485's.  I´ll let you know...kind regards,


 
  Hi J,
   
  Glad you were able to source the 6485s at such a good price - and to have someone match a pair is even better!
  I cannot wait until you try them, given your findings re the Voskhods...mine have done about 50 hours now, and combined with about 40 hours on a pair of early 6N30P-DRs I cannot believe what my ears  - and brain - are experiencing. I can only hope your setup (and you!) are  treated to something similar...
   
  Thanks to Gibosi for the info re EF95 setting.
   
  Your comments re soldering were interesting - just might have a go sometime. Methinks the complex alloys used in the pins - possibly manganese/zinc/nickel/copper/cobalt - would contribute to the very careful preparation needed before getting anywhere near with the iron. I, and others on this forum I am sure, look forward to your outcomes in this feat!
   
  Regards, CJ


----------



## mordy

Hi Gibosi,
   
  Yes, I have also been investigating the modified triode tubes 6AV6 and 8532. (Let's stick to calling them modified tubes rather than mutilated tubes; sounds much better, doesn't it?)
   
  Finally got four different 6AV6 tubes: Two sidegetter Sylvania and RCA, a 50's-60's Tung Sol and a late 70's-80's Sylvania/Phillips. I assume that the side getter tubes are the oldest. Not one tube is identical to the other as far as the internals go. In addition one Sylvania 8532 tube that has a completely different construction.

  From right to left: RCA with side getter with silver plate; 50's- 60's Tung Sol, late model Sylvania-Phillips with curious small ring attached to the Gray plate {don't forget to double click picture to get a full view}, older Sylvania side getter, and the 1970 Sylvania 8532.

  "Band-aid" view. Agree with Inphu510n that it feels strange to render the tubes unusable for others. This will explain why I only got one of each - they were all less than $2.50 including shipping. I figured I'll try them out, A/B them on a good mono recording, and I would find out what I like the best.
   
   
  First I printed out pictures of post surgery tubes from the blog, as well as the pin charts. Then I marked the pins to cut off with a black marking pen. Used a small jeweler's cutter, took a deep breath and squeezed. I heard the cut off pin land somewhere on my cluttered desk - wasn't too hard to cut the pin. Little stumps were left (think beaver) and I was able to take off a little more with the cutter. (My retired engineer friend had told me not to file the excess down because I might damage the vacuum seal.) Then I took electric tape and cut a tapered piece so that it is smaller between the pins and bigger outside the pin perimeter for better adhesion.
  Success!
  Heavily perspiring I grabbed my tweezers and pulled out the pesky jumpers, using a flashlight to see inside. Managed to get them back in the E92 position without bending the pins inside the LD.
   
  Also got a pair of RCA 6BY6 heptodes from Oct 1966. (I anybody is interested, I could post a RCA code chart from 1956-1976.) Convenient to listen to these as well, as they use the EF92 setting.
   
  With all this sensory overload it will take a little time to sort out the winners and losers. Truth is, most of the new tubes have been very nice, heads and shoulders over the traditional tubes.
   
  Then, when I have picket a winner (or several), I am going to do a shoot out with the EF95 strap 2&7 setting on one channel and the EF92 setting on the other channel to compare the 6AH6/6AU6/4825 to the triode-heptode families. -Better get a good night's sleep before so that I don't make any mistakes in rigging it up!


----------



## MIKELAP

I got response from the guy regarding the socket adaptor he says they can do the adaptor but before i order i want to make shure that the o.d. of the socket fis in th mk3 hole anyway heres his message                                           Hello,

  Sorry, yesterday we were on holiday, we can made the 7 pins to 7 pins adapters for you, price is: 16.5 dollars, shipping cost for 1-4 pcs is: 5 dollars,

 How many pcs would you like to buy?

 Thanks&Best Regards,
 Vanessa
  
 [size=10pt] - happydiy998[/size]


----------



## gibosi

Quote: 





mordy said:


> ..........I only got one of each - they were all less than $2.50 including shipping. I figured I'll try them out, A/B them on a good mono recording, and I would find out what I like the best.
> 
> Then, when I have picket a winner (or several), I am going to do a shoot out with the EF95 strap 2&7 setting on one channel and the EF92 setting on the other channel to compare the 6AH6/6AU6/4825 to the triode-heptode families. -Better get a good night's sleep before so that I don't make any mistakes in rigging it up!


 
   
  It's nice to know that someone else is finally listening to triodes. And I must say you have a very efficient and cost-effective way to evaluating tubes!
   
  As we have three in common, Sylvania 8532, and Sylvania and RCA 6AV6 with side-getters, I will be very interested in your impressions of these three. I tried to find a nice pair of Tung-Sol 6AV6 with no luck, and will also be very interested in what you think of it.
   
  Good luck to you as you embark on your tube marathon!


----------



## gibosi

Quote: 





hypnos1 said:


> Your comments re soldering were interesting - just might have a go sometime. Methinks the complex alloys used in the pins - possibly manganese/zinc/copper/cobalt - would contribute to the very careful preparation needed before getting anywhere near with the iron. I, and others on this forum I am sure, look forward to your outcomes in this feat!


 
   
*Inphu510n* has successfully soldered pins 2 and 7 together (post #1026 page 69). If you encounter any problems, you might want to contact him for his advice.


----------



## MIKELAP

Quote: 





gibosi said:


> It's nice to know that someone else is finally listening to triodes. And I must say you have a very efficient and cost-effective way to evaluating tubes!
> 
> As we have three in common, Sylvania 8532, and Sylvania and RCA 6AV6 with side-getters, I will be very interested in your impressions of these three. I tried to find a nice pair of Tung-Sol 6AV6 with no luck, and will also be very interested in what you think of it.
> 
> Good luck to you as you embark on your tube marathon!


 
  www.tubebazar.com         I checked my guy site these are the 6av6 he has.  Tun-sol i dont know youll have to check.                           

 6AV6 REF: EBC91 Yes / Oui 6AV6 / EBC91 Yes / Oui 6AV6 - F4A Yes / Oui 6AV6 - F8 Yes / Oui 6AV6 - H5 Yes / Oui


----------



## gibosi

Thanks for the pointer. However, I think I will hold off on the Tung-Sols until we have Mordy's impressions. Besides, I have the 5 pairs of triodes above to butcher and burnin, plus I have a few more triodes coming, so buying more tubes is the very last thing I should be doing. lol
   
  This morning I butchered the RCA 6AV6 and they have been burning in for about 10 hours now. First impressions, these are good sounding tubes....


----------



## mordy

Hi Gibosi,
   
  LOL, firstly, let's keep up the high ethical standards of this forum 
	

	
	
		
		

		
			





 and not amputate or butcher tubes, just modify them for our needs.
   
  To evaluate 5 new tubes takes a lot of mental energy, so I temporarily put aside this project in favor of evaluating a pair of RCA 6BY6 heptodes, which is an easier mental challenge. (Paid $5.25 total incl. shipping from a nice seller.) These only require the EF92 setting and nothing else (Plug and Play?).
   
  At first I was not impressed by them. Nothing objectionable in the sound, but the treble was too bright and a little sibilant, and the bass was not very deep and a little weak. The mid range was pretty good but I thought that these tubes are not any better than a good 6AK5 tube.
   
  However, you have to take your own advice and be patient. Tubes need to burn in, usually a minimum of 20 hours and some 50 hours (Voskhods need 120 hours). So I stuck in the 6BY6 tubes and left my system on, on low volume. These tubes do not get very hot, and I can easily touch them without worry.
   
  {About my own advice: If you have trouble with a tube quitting on you suddenly, scrape the pins gently to get off the oxidation. I was going to practice cutting off the pins for the triodes, but could not think of a defective tube to cut. Then I remembered that one of the original LD 6N6P-i power tubes had stopped working. For some reason I had saved it around two years. Well, before doing the surgery I looked it over, looking at the pins. One pin looked greenish. Out came the pocket knife. Plugged in the tube. What??? It is working!! Couldn't believe it....}
   
  Well, after supper I couldn't believe this either! The 6BY6 tubes had suddenly come to life after about 25 hours of use! The sound stage suddenly became huge with sound emanating from outside of the speakers on some recordings. The bass became much stronger. The mid range is sweet. The treble is still too bright, but can easily be adjusted with my tone control. I am hearing the same type of magic as from the 6AH6/6AU6 tubes. Not as detailed, not the same pin point imaging and clarity, but nevertheless a sweet, warm and engaging (tubey?) sound.
   
  I feel that these still need more time - will keep you posted.


----------



## MIKELAP

So its a go for the sockets there suppose to fit the littledot mk3 the price is $16.50 each plus $5.00 shipping for up to 4 pieces . I ordered 2 so we will see what happens they will ship in a couple of days and i hope its faster from China that it was from Russia if you recall (1month).in the meantime im expecting my 6AU6 AND 6BE6 tubes in a few days ,seller infos :                         [size=13.333333015441895px][size=small]happydiy998[/size]     [/size]


----------



## gibosi

Mikelap,
   
  This is great news! And I sure hope that they don't take too long, but from their website, it could take up to 40 days....  On the other hand, some small stranded wire will suffice until they finally arrive.
   
  I have decided to take my socket testers to a jeweler to see if he would be willing to solder some connections for me. As cheap as these were, $7 each, I ended up purchasing 6 of these, one pair for pins 2 and 7, a second pair for pins 5 and 7, and the third pair will remain stock in case I need something different later. I figure jewelers are very proficient doing intricate work with small pieces of wire, so this should be very easy for them. I hope...
   
  In the meantime, I "modified" a pair of Mullard 6AV6 (I still think "butchered" and "mutilated" convey a more honest and accurate description of what we are actually doing to these tubes!  and they are currently burning in. These too sound very promising. If it turns out that you end up having to wait some 40 days for theses adapters, I would encourage you to pick up a few triodes. I think you will be very pleased with what you hear.... and besides butchering and mutilating tubes is fun!


----------



## MIKELAP

My dremel is itching to cut something and besides my wife calls me Mr. Mod because being an ex machinist i cant leave anything alone gotta mod it i have to read up on the thread to see which tubes you guys MODIFIED or maybe you can give these tired eyes a break and give me the tube numbers you guys are OPERATING  on . Thanks guys.


----------



## gibosi

We are "operating" on 6AQ6, 6AT6 and 6AV6 (from the same manufacturer these three are typically very similar) and the 6J4/8532W/CV5311. You could try a cheap pair of 6J4 first and then pick up a pair of 8532W and/or CV5311, if you like them.
   
  Just cut off pins 5 and 6 (check out my post #1066 on page 72) and use the EF92 jumpers. I initially used my dremel to do this, but using flush cutters (post #1021 page 69) is much, much easier and safer (for the tube).


----------



## MIKELAP

Quote: 





gibosi said:


> We are "operating" on 6AQ6, 6AT6 and 6AV6 (from the same manufacturer these three are typically very similar) and the 6J4/8532W/CV5311. You could try a cheap pair of 6J4 first and then pick up a pair of 8532W and/or CV5311, if you like them.
> 
> Just cut off pins 5 and 6 (check out my post #1066 on page 72) and use the EF92 jumpers. I initially used my dremel to do this, but using flush cutters (post #1021 page 69) is much, much easier and safer (for the tube).


 
  Your so kind thanks a bunch.


----------



## hypnos1

Quote: 





mordy said:


> Hi Gibosi,
> 
> LOL, firstly, let's keep up the high ethical standards of this forum
> 
> ...


 
  Hi mordy,
   
  Re your comments on oxidised pins, I wonder how many people are getting below-par performance from their LD simply because of this inevitable consequence - eventually at least (my MKiv SE came with such crud on the Mullards 'twas a wonder the poor thing worked at all!
   
  The solution? I got myself a silver-plating kit, and treat the pins to something lovely to behold...so hopefully no such worries in the future?...And the added bonus of improved conductivity - even the black silver oxide is better than (clean) copper. With any luck the sound will also be helped, especially following the principle of having similar metals , if possible, throughout the system - have pure silver interconnects and pure silver headphone cable (mainly because of the incredible difference I found after replacing rather good copper speaker cables, again with pure silver, and especially the INTERNAL wires of the Dynaudios).
   
  So now, if only I could get to the socket holes...then any wire inside the LD...then...oh dear, getting rather carried away now. Had better say cheerio for now.
   
  The moral? Look after your pins everyone!!


----------



## mordy

Hi hypnos 1,
   
  Regarding cleaning the tube pins, there has been research done and my recommendation to scrape the pins lightly and gently is based on a 1945 study that I referenced a long time ago on this forum. Here is a much more recent quote that I just found from some electronic scientist:
   
  " Folks, I am going to jump in here and I hope I do not upset any body with what I post. I work for a major computer company in a part of the business where we are very concerned with metal on metal electrical contacts. I have no idea how much money and how many hours we have poured into studying this, but it is a lot! The results of all of this research has shown beyond any doubt that the absolute best electrical contacts come from a metal on metal swiping action where at the atomic level the atoms of the one metal side are mechanically smeared into the atoms of the other metal side. If the mechanical smearing is good enough it actually seals out the oxygen and other molecules (to explain why takes some pretty heavy duty solid state physics and this is not the place for that). Any foreign substance no matter what it is only impedes the electrical contact. Now, if the metal surfaces are dirty or corroded in any way cleaning them back to pure metal is absolutely the right thing to do. However, the idea that some fluid (whether it is metal loaded or not) is going to improve the electrical contact by lubrication is just not supported by research in this field. "
   
  About cleaning the the tube sockets: There are many posts about this and many methods. After reading through a lot of stuff, my opinion for now is that it takes very little contact area to make a good contact with the pins inserted into the tube socket (witness the tiny little thin gauge stranded wires in the 2-7 strap used successfully as reported on this forum). Following the old adage "If it ain't broke, don't fix it" sounds like a good idea.
  However, if there is crackling etc and it is not the problem of the tube pins, and moving around the tube does not help, some people spray a little high temperature Gold Deoxit on tube pins and push the tube in and out 6-7 times. People warn not to use anything that does not evaporate quickly - gunk and residues are not what you want in the pin holes. (Some people say that you can using rubbing alcohol in a pinch.)
  For mechanical cleaning thin pipe cleaners may work, as well as small tip cleaning brushes used to clean welding tips (available from welding supply stores). There may also be thin brushes used to clean guns and rifles available in sporting goods stores. A thin Dremel brush may work if used with your fingers only.
   
  Here is a link to a tube cleaning kit:
  http://www.musicdirect.com/p-1158-caig-vacuum-tube-survival-kit.aspx
   
  And here is a video advertising this kit:
  http://www.youtube.com/watch?v=n9r_ZPHxuIQ
   
  Note that the Music Direct price is much less than that in the video.
   
  What do I do myself? I just push the tube in and out of the socket a few times - so far so good....


----------



## rosgr63

I use a ladies fine nail file and sometimes Flitz.
   
  The Gaig cleaners ere not effective from my experience but Deoxit Gold is excellent for pin preservation and better contact.


----------



## mordy

Thanks for suggestions. Looked up Flitz, but they make many different cleaning products. Could you specify which one you recommend? (Gun bore cleaner?)


----------



## hypnos1

Quote: 





mordy said:


> Hi hypnos 1,
> 
> Regarding cleaning the tube pins, there has been research done and my recommendation to scrape the pins lightly and gently is based on a 1945 study that I referenced a long time ago on this forum. Here is a much more recent quote that I just found from some electronic scientist:
> 
> ...


 
  Hi mordy,
   
  Thanks for your very informative post - I am so glad I found this forum, especially this particular thread with such knowledgeable and helpful guys...(where are the gals I ask?!)...
   
  The report you quoted was very interesting and has got me thinking further re my silver-plating viz 1. The maintenance of metal to metal contact through the inhibition of (bad) oxidation/corrosion - I am a firm believer in prevention rather than cure, and sound quality must surely be compromised well before any 'crackling'/tube failure...2. I may well be "up in the clouds" now, but I wonder if the softness of the silver coating might just help in the 'purity' of the contact between pin and socket, thereby assisting the possibility of the 'atom smearing' mentioned in the quote and thus the benefits of oxygen etc. reduction. Even if this is rather fanciful, the mental imagery of this taking place will almost certainly have me BELIEVING good things are happening! - the musical experience is in good measure a PSYCHOLOGICAL one...which is another reason why I do like to 'tweak' things, so long as it doesn't cost too much. And sometimes tweaks can result in definite empirical improvements.
   
  Whatever, I shall continue to follow these wonderful posts with relish and look forward to even more words of wisdom from such a dedicated group of contributors - thanks to all of you.


----------



## rosgr63

Quote: 





mordy said:


> Thanks for suggestions. Looked up Flitz, but they make many different cleaning products. Could you specify which one you recommend? (Gun bore cleaner?)


 
   
  You are most welcome.
   
  It's the Metal, Plastic and Fiverglass polish paste.
  It also offers protection against corrosion.
   
  http://www.flitz.com/p-16-flitz-polish-paste.aspx


----------



## mordy

Hi h1,
   
  Welcome to the forum! The writer I quoted says mainly that liquids cannot improve metal to metal contact. I cannot see anything wrong with silver plating if it works for you. There are companies that gold plate the tube pins (Sylvania, Electro-Harmonix and others) so they must see a benefit in doing so.
   
  I assume that the purpose of liquids is for cleaning purposes, and it seems that it is very important that no residue is left after the cleaning since it may interfere with the metal to metal contact.
   
  IMHO the main thing is to enjoy listening to the music and not listening to the equipment (although I am told that there are people that mainly enjoy the latter).
   
  When evaluating tubes I am forced to listen to the equipment. Sometimes the experience is such that you forget what you are doing and you just enjoy the music instead!
   
  Cheers,


----------



## mordy

Hi All,
   
  Remember the mention here about buying Little Dot MKIII amps for $10 + shipping?
   
  Well, the dirt is hitting the fan already! If anybody bid on this, call up Ebay and ask for your money back right away.
   
  Exhibit A:http://www.head-fi.org/t/663519/ebay-scam-auction-little-dot-iii-for-9-50-s-h
  This is a new thread on this scam.
   
  Exhibit B: http://feedback.ebay.com/ws/eBayISAPI.dll?ViewFeedback2&userid=qiangzhanghihi&&_trksid=p2047675.l2560&rt=nc&iid=171035236990&sspagename=VIP:feedback&ftab=FeedbackAsSeller
  The feedback is starting from scammed people.
   
  If it is too good to be true, it is too good to be true.....


----------



## Acapella11

Quote: 





mordy said:


> Hi Gibosi,
> 
> LOL, firstly, let's keep up the high ethical standards of this forum
> 
> ...


 
   
 Hi Mordy, good to see you tried some 6BY6! Interesting observation with the treble, I also felt it gets gentler over time with my 6BE6-type Sylvania JAN 5750 in which case I actually didn't appreciate it but tubes in these families seem to have different amounts of treble. If the treble after burn in still is too much for you, I would suggest to use the EF95-setting, which is likely to resolve that issue.
 Interesting also you mention that large stage and sweet mids, my 6BE6 sound agrees with that. For the details. Hmm. Maybe they are not as detailed as the 6BE6? Possible. Or they need more burn in. I found that large stages can also lead easier to the impression of lesser details if imaging and resolution do not scale with the stage, then you will find less details per musician. In contrast, if the stage is small, especially not deep and the imaging is just OK you will still have the musician right in front of you and it may seem more detailed. My personal preference goes to larger stages and resolution in treble and mids because I find vocals, guitars, violins etc., space and reverb in recordings to match my fascination most. A good balance is a big plus of course. Got side-tracked... Would be interesting to hear your opinion on a Tung Sol 6BE6 if you cheaply come across one  I find them quite detailed to say the least...
  
 Gibosi, exciting adventures with your butchered, mutilated, cut, modified, altered, adapted, compatibilised 6AV6 tubes. How are your impressions? Oh, and what is your opinion about the GE JG-5750/6BE6W after having had your cans for longer?
  
 Mikelap, enjoy your 6AU6 and 6BE6 tubes. Congrats to those.
  
 Hypnos1, good to see you around in this thread and congrats to your 6H30P-DRs  I am still playing with the thought of getting a pair myself.
  
 Oh, and of course I won't deny my roots: If not DRs, when you are rolling tubes, you may as well get a pair of power tubes you do not have (6H30P, 6N6P-IR) since you are at it 
	

	
	
		
		

		
		
	


	




 Power tubes make a difference, and more the better your gear gets 
	

	
	
		
		

		
		
	


	



  
  
  
 LD I+/III/IV-Tube compatibility table: Page 77, post 1154


----------



## inphu510n

Regarding tube cleaning, I typically use the back of the tip of an Xacto knife. Using the flat side I scrape repeatedly all sides of the pins.
  It's a bit laborious but all of the pins I do this with turn out quite shiny. This also helps with solder affinity. 
   
  So, I'll be the first to admit it. This is another reason I dislike clipping pins off of tubes...
  I cut the wrong pins last night!!!
  I looked at the diagram for the socket, not the tube, and ended up cutting pins 2 & 3 off of a pair of Sylvania 6AV6 tubes.
  So annoyed with myself! At least they were only around $9 shipped for both.


----------



## gibosi

Quote: 





inphu510n said:


> So, I'll be the first to admit it. This is another reason I dislike clipping pins off of tubes...
> I cut the wrong pins last night!!!
> I looked at the diagram for the socket, not the tube, and ended up cutting pins 2 & 3 off of a pair of Sylvania 6AV6 tubes.
> So annoyed with myself! At least they were only around $9 shipped for both.


 
   
  This is a bummer! But at least they were cheap tubes and I am quite sure you will never do this again... So get some more tubes and get cutting!!


----------



## gibosi

Quote: 





acapella11 said:


> Gibosi, exciting adventures with your butchered, mutilated, cut, modified, altered, adapted, compatibilised 6AV6 tubes. How are your impressions? Oh, and what is your opinion about the GE JG-5750/6BE6W after having had your cans for longer? 
   
  I haven't listened to the TS 6485 or any other tube requiring the 2-7 strapping since my sockets went flaky. And as a consequence, I haven't heard any of these reference tubes with my new headphones, only triodes. And thus, I can't compare any of the tubes I am currently using to the tubes the rest of you know well.  
   
  My goal is to get a handle on all these triodes and then report back, comparing them to each other, with the hope that it might be somewhat useful.....
   
  And then I need to send some time with the GE JG-5750/6BE6W and the RCA JRC 5915. But again, few if any of you know these tubes well either.....
   
  I took my test sockets to a jeweler/goldsmith today, and she thinks she can do what I want, but won't be able to get to them until next week. If she is successful, then I will finally be able to listen to the TS 6485, and perhaps provide more meaningful comparisons.
   
  In the meantime, I continue to cut pins and burn...  The GE 6AV6 are burning in as I write this... So far, first impressions, I like the GEs and the Mullards the best. The highs on Sylvania and RCA 6AV6s seem a bit to bright to me, but they all need to burn in more.... and perhaps my headphones also need to burn in more too.....
   
  Cheers


----------



## MIKELAP

Hey guys this is off topic but have a listen to this, singing is my sons girlfriend she has a very nice voice.  Thanks.  http://youtu.be/q0ZWG4NZDjo


----------



## hypnos1

Hi Mikelap . Yep, she has a lovely voice - and it's one of my favourite songs...it was nice to hear it again. I hope she goes far with her singing.
   
  Many thanks to mordy and A11 for the welcome - much appreciated.
  The 6N(H)30P-DRs replaced the 6H30P-EHs, which might well go back in for any further rolling. I did get some 6N6Ps (gold grid), but apparently David at LD said they were not suitable for the later MKiv SE - wish I knew why...
   
  On the subject of rolling, the TS 6485s are proving to be so magical I cannot believe things could get any better - but never say die!! I have yet to try a pair of Sylvania Gold Brand 5750s - but A11, did you say the TS 5750s were better? Anyways I am looking forward to seeing how they compare to the 6485s. This rolling is somewhat addictive, but great fun and also very illuminating. And certainly FAR less expensive (and more convenient) than trying different combinations of source, amplifier, connector etc. etc.
  But of course it's you guys, plus gibosi and audiofanboy who do all the real hard work - long may you prosper! All we lesser mortals owe you a debt of gratitude. Keep up the good work...


----------



## MIKELAP

Quote: 





hypnos1 said:


> Hi Mikelap . Yep, she has a lovely voice - and it's one of my favourite songs...it was nice to hear it again. I hope she goes far with her singing.
> 
> Many thanks to mordy and A11 for the welcome - much appreciated.
> The 6N(H)30P-DRs replaced the 6H30P-EHs, which might well go back in for any further rolling. I did get some 6N6Ps (gold grid), but apparently David at LD said they were not suitable for the later MKiv SE - wish I knew why...
> ...


 
   
   

  
  
 [size=1.5em] Re: Little Dot Mark IV SE tubes compatibility[/size]  

by *Chocki* » Jul 7th, '12, 17:17

 [size=1.3em] Well my 6N6P Gold grid power tubes arrived this morning, I've had them in all day circa 12 hrs playing while I've been working doing the kitchen up.
 Impressions are very favorable, they are as good as the 6H30PI's but last a lot longer being military ruggedised. They start off completely silent at max volume with no imput (Remember my headphones are much lower resistance than sennheiser HD 650's so everything is much louder), but after 12 Hrs, they also exhibit some slight static noise but nothing like like the 6H30PI's, not that I ever listen at max output and it really is faint, while checking this out what I did notice though is that the LD DAC_1 suffers from crosstalk!. With IN2 playing, selecting any other input, you could still hear IN2 (RCA SPDIF) very faintly at max volume. Again not the slightest bit worried as I only intend to listening to one source.[/size]


  Found this on Littledot site and its dated july 2012 did they change the model after that.


----------



## Audiofanboy

Finally back after a few days of vacation, and still no triodes on my doorstep, though I apparently have a package waiting for me at my local post office; could either be my second 8532W tube, or my last -major- order, that I placed last week just leaving for the airport.
   
  Speaking of ordering tubes, and seeing how I'm still missing out on all the triodes and even heptodes fun, here is what I have on ice, ordered from an obscure UK tube company, and that should get to me within this week.
   
  - Mullard 6BE6W (were originally Syvlanias, but turned out to be Mullard when the seller checked the stock, I'm not sure whether that's good news or bad news, I'd say good, since Acapella seems to have already found better 6BE6 tubes than the Sylvanias, making buying them a bit pointless)
   
  - Brimar CV4012 (UK mil spec 6BE6 type, kind of curious as to what these even look like)
   
  - Pinnacle EBC91 (European 6AV6 type, were supposed to be Telefunken and cheap-ish, but turned out not to be when the seller checked them, but could be sourced from any European brand from Mullard to Telefunken, or silly Russian tubes; Pinnacle seems to have a decent reputation depending on the rebranded tubes, so it's a bit of a gamble. Considering the same labeling/branding happened with the 6BE6W when the tubes were checked from the seller's stock (I've seen Sylvania tubes which were Mullard imports, so they might be Mullard made but Sylvania branded, hence the information in the stock list) I'm hoping the same holds true for these; there must be a reason why they had been entered in as Telefunken by the seller in the first place?)
   
  - Telefunken EH900S (6BY6 type, similar to the 6BE6 and made by Telefunken, supposedly high grade tubes, can't be horrible can it...? Could have gold pins or not, both versions seem to have existed)
   
  - Mullard CV4070 (UK mil spec EC91 type -that I think I may have mentioned here before unofficially- possibly dual labeled M8099, ground-grid triode like the 6J4 with even more interesting characteristics, the mil spec versions of the EC91/6AQ4 seem to be hard to come by, hence my not having made these official yet)
   
  - Mullard CV5311 (UK mil spec 6J4 type, possibly dual labeled M8248, not from the same -unique ebay- seller as gibosi though, hopefully very nice tubes)
   
  So I can -finally- get back on the tube rolling band wagon and start giving impressions again; this, despite my still being absolutely mesmerized by the Tung-Sol 6485... These are a very, very, clear-cut grade above all my other tubes, and that's saying a lot.
   
  About those socket adapters, did the Chinese ebay seller ever mention sizes? Basically, I'm trying to figure out if I could even fit an adapter on MK IV SE sockets without "modifying" the golden tube protectors that make it look so pretty in the first place, which I probably wouldn't do...


----------



## MIKELAP

Burning in some tung-sol 6BE6 they seem to be lighter on the bass but maybe more detailed i like the violins on these tubes .Soundstage is good . What are your impressions.


----------



## MIKELAP

I ordered a pair yesterday he didnt mention the diameter but he said that it would fit the mk3 When i get the sockets will measure the exterior and post. i asked for 6ak5 to 6au6 socket adaptor hope i get them soon but like i said to gibosi if its anything like Russia its going to take a while anyways ill keep you guys posted


----------



## Acapella11

Hi Mikelap, Agree on great stage and detailed. Two big points. With respect to bass: Also agree with this not being a bass heavy tube. I would almost say the frequency spectrum is slightly skewed to mids and treble, not in a bad way though. To give a bigger picture, IMO they were so clean that there was no bass "coloration" when no bass was produced and once bass kicked in, its quality was actually really good  - well articulated and punchy. After tube and brain burn in, I didn't find them bass light. Why I found the tube special really was, because it just sounds so clean with a black background. Every other tube slightly distorted on certain transients and broke small details in the imaging, listening to violins for example (as you mentioned them), but these didn't. Details... 
 IMO and generalized, the 6BE6 signature matches approximately that of CV4015 and TS 6485, more inclined towards the TS 6485.
  
 Gibosi, OK. Good luck sorting out your sockets!
  
 Hypnos, 6N6P gold grid? Agree with Mikelap, that's really standard stuff. Pop them in. They should be fine. Depending on year of production, which I guess is more critical than the gold grid, you may find them more or less useful. If I remember correctly, Mordy uses 6N6P gold grid from the Cold War times.
  
 Audiofanboy, WB and your new tube menue looks very yummy indeed.


----------



## zedmeco

http://www.ebay.co.uk/itm/300630722142?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649
   
http://www.ebay.co.uk/itm/2-Stk-ECC99-JJ-Tube-Rohrenverstarker-Rohre-HighEnd-12BH7-matched-Paar-NEU-/200775278980?pt=R%C3%B6hren&hash=item2ebf23a184
   
  I started searching for power tubes, 6n6p ir, I have a few from different years and some with the gold pins.  Very happy with them but in the spirit of tube rolling i thought i would extend the search to include the ecc99 and found these. do you guy's think they will work, i haven't ordered them yet though I have asked Yen if he thinks they would work.


----------



## MIKELAP

Quote: 





acapella11 said:


> Hi Mikelap, Agree on great stage and detailed. Two big points. With respect to bass: Also agree with this not being a bass heavy tube. I would almost say the frequency spectrum is slightly skewed to mids and treble, not in a bad way though. To give a bigger picture, IMO they were so clean that there was no bass "coloration" when no bass was produced and once bass kicked in, its quality was actually really good  - well articulated and punchy. After tube and brain burn in, I didn't find them bass light. Why I found the tube special really was, because it just sounds so clean with a black background. Every other tube slightly distorted on certain transients and broke small details in the imaging, listening to violins for example (as you mentioned them), but these didn't. Details...
> IMO and generalized, the 6BE6 signature matches approximately that of CV4015 and TS 6485, more inclined towards the TS 6485.
> 
> Gibosi, OK. Good luck sorting out your sockets!
> ... 
  With time hopefully my descriptions will improve as for your description its on the money thats what i am earing.


----------



## vic2vic

Hi everybody,
  first of all thanks to all of you for this amazing an super informative thread. My wallet is not so happy after all the new found tubes, but my ears definitely are 
	

	
	
		
		

		
			




   
  I have a question regarding the 6BE6, 6CS6 group, for which I've not yet got any tube: did anybody had a chance to try (or ordered) the *Mullard EH90* ? They should be very similar to the 6CS6, but I'm not 100% sure.
   
  By the way, I confirm that almost all tubes mentioned in the table on page 77 are also working perfectly in the Little Dot MK II+ amp. I said "almost all", as I have not tried the 6BE6 family and the "modified"6J4 / 6AV6 ones... yet.


----------



## gibosi

Quote: 





vic2vic said:


> I have a question regarding the 6BE6, 6CS6 group, for which I've not yet got any tube: did anybody had a chance to try (or ordered) the *Mullard EH90* ? They should be very similar to the 6CS6, but I'm not 100% sure.


 
   
  Yes, and in fact, the 6CS6 and EH90 are the same tube. EH90 is the European designation for 6CS6, and thus you will often see it used in reference to European manufactured tubes. Oh, but no, I haven't tried it....
   
  This site is very helpful in sorting out what is equal to what:
   
  http://www.radiomuseum.org/tubes/tube_6cs6.html


----------



## hypnos1

Quote: 





mikelap said:


> [size=1.5em] Re: Little Dot Mark IV SE tubes compatibility[/size]
> 
> by *Chocki* » Jul 7th, '12, 17:17
> 
> ...


 
  Hi mikelap.
   
  Thanks for the quote/link. Chocki didn't seem to have any problem with the 6N6Ps, and I think the only modification was to hardwire so as to remove the  jumper option.
  I can only assume the LD people found (or presaged) a possible problem with long-term use....Whatever, he found the 6H30Pis a better match for the Senn HD650, which I have, so methinks I would be foolish to take any kind of risk - everything is sounding so darned good now (up yet ANOTHER notch with just 15 more hours on the tubes - is it the 6485s or the DRs? Both probably...).
  Am almost afraid to even try the 5750s, I'm so star-struck!! This rolling can be a bit of a roller(sorry!)coaster ride, to say the least. Ah well, 'agony and ecstasy' is obviously not restricted to just artists!


----------



## gibosi

Quote: 





mikelap said:


> I ordered a pair yesterday he didnt mention the diameter but he said that it would fit the mk3 When i get the sockets will measure the exterior and post. i asked for 6ak5 to 6au6 socket adaptor hope i get them soon but like i said to gibosi if its anything like Russia its going to take a while anyways ill keep you guys posted


 
   
  Thanks to Mikelap's considerable efforts, you can now order 6AU6 to 6AK5 tube adapter socket converters on eBay!!
   
  http://www.ebay.com/itm/1x-6AU6-to-6AK5-tube-adapter-socket-converter-/290917075011?pt=Vintage_Electronics_R2&hash=item43bc024843


----------



## Audiofanboy

Quote: 





gibosi said:


> Thanks to Mikelap's considerable efforts, you can now order 6AU6 to 6AK5 tube adapter socket converters on eBay!!
> 
> http://www.ebay.com/itm/1x-6AU6-to-6AK5-tube-adapter-socket-converter-/290917075011?pt=Vintage_Electronics_R2&hash=item43bc024843


 
   
  Well, color me impressed; that's actually kind of cool to have our very own custom adapter! Next step would be the "adapter" that disables pins 5 and 6 at the tube level, yet cleanly links pin 7 to either of those at the socket level (so we can use all those cute triodes (6J4, EC91) and double diode-triodes with the EF95 setting and with no "pin modification" bloodshed, or was it metalshed?).
   
  As a side note, it looks like it could fit on an MK IV, though I would prefer a more brassy or aluminum feel to the adapter for that kind of amp... Oh well, can't win them all.


----------



## MIKELAP

Quote: 





gibosi said:


> Thanks to Mikelap's considerable efforts, you can now order 6AU6 to 6AK5 tube adapter socket converters on eBay!!
> 
> http://www.ebay.com/itm/1x-6AU6-to-6AK5-tube-adapter-socket-converter-/290917075011?pt=Vintage_Electronics_R2&hash=item43bc024843


 
  HOLD THE PRESSES. mordy is responsible for that considerable effort he found the site for those sockets in the first place but i still would like to thank my mother ,father and my wife whithout whom none of this would be possible Thank you .


----------



## Nic Rhodes

I have to say as a long term tube roller this is one of the best threads I have come across (took me days to read as well!). I think I will buying a LD to roll in the near future.
   
  From my perspective I would be after 7 pin adapters for 7 / 1 pin and 2 / 6 'mods'' for an amp. This is far better than buttering old gems 
   
  If you guys like rolling 6AU6s you need to investigate 7543 tubes (mine are sylvania but a common type that when I bought was dirt cheap). These were a SQ type that was a low hum, low microphonic version of the 6AU6.


----------



## Acapella11

Quote: 





mikelap said:


> With time hopefully my descriptions will improve as for your description its on the money thats what i am earin


 
  Mikelap, Don't worry. Great we agree =)
  Amazing, you got that socket sorted! 
	

	
	
		
		

		
		
	


	



  Yes, the pin 5-6 pin disconnect socket adapter and even an adapter for EF91/92 compatibility would be useful ("pesky jumpers") and then maybe later one for 12BH7 power tubes =)
   
  Quote: 





vic2vic said:


> I have a question regarding the 6BE6, 6CS6 group, for which I've not yet got any tube: did anybody had a chance to try (or ordered) the *Mullard EH90* ? They should be very similar to the 6CS6, but I'm not 100% sure.
> 
> By the way, I confirm that almost all tubes mentioned in the table on page 77 are also working perfectly in the Little Dot MK II+ amp. I said "almost all", as I have not tried the 6BE6 family and the "modified"6J4 / 6AV6 ones... yet.


 
   
  Vic2vic, Haven't tried them yet and I will update the table on page 77 accordingly. Thanks for the info.
   
  Quote: 





zedmeco said:


> http://www.ebay.co.uk/itm/300630722142?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649
> 
> http://www.ebay.co.uk/itm/2-Stk-ECC99-JJ-Tube-Rohrenverstarker-Rohre-HighEnd-12BH7-matched-Paar-NEU-/200775278980?pt=R%C3%B6hren&hash=item2ebf23a184
> 
> I started searching for power tubes, 6n6p ir, I have a few from different years and some with the gold pins.  Very happy with them but in the spirit of tube rolling i thought i would extend the search to include the ecc99 and found these. do you guy's think they will work, i haven't ordered them yet though I have asked Yen if he thinks they would work.


 
   
  Zedmeco,
  Quote: 





> ECC99 is similar to 12BH7A, and is a drop-in for most applications. Please note that on some amps, 12BH7A is used in power supply circuits and ECC99 is not a drop-in. If you are not certain, please check with the amp manufacturer first. (http://www.boiaudioworks.com/12bh7)


 
  duncan1 explained the mod required to operate in post on page 75, post 1125. I have posted the pin layout and the 6N6P layout in comparison above duncan1 on the same page and down here. Here is duncan1's post, I have highlighted the practical bit:
   Quote: 





> Look on the heaters as 2 resistors connected together at the center tap the  current flow through both will be the same 2 equal resistances connected in parallel the total resistance is HALVED[more current used] if connected to the other heater connection at the center  tap.    Applying  12V across -4+5 without using the CT will reduce the amount of current through them for use in other equal current heater circuits.by INCREASING the total resistance[lower resistance=higher current].[higher resistance=lower current]
> *So "double connect"-IE- shorted together 4+5 and the other heater connection to 9-AFTER you have removed the earth connection to it.*


 

  I was about to consider this an easy mod: Connect 4-5: fine, then connect to 9: fine, AFTER you remove the earth connection to it: Hmm, how do I remove the earth connection from 9?
   
  Nic Rhodes, welcome to the thread. Thanks for pointing to the 7543 tubes, I will update the table on page 77 with this info as well. A quick ebay search brought only one tube from this type. Do you happen to have a good source for these?


----------



## gibosi

Just a quick note. I cut off pins 5 and 6 on a pair of Mullard EC91/6AQ4 and rolled them in, using the EF92 jumpers, as we have for the other triodes, and right out of the box, they sound very good. But then, all of the triodes I have tried recently sound very good, so not a big surprise.


----------



## mordy

Hi Mikeleap,
   
  Thanks for the acknowledgment. Upon seeing all kinds of adapters by this high end outfit in Hong Kong, I asked them if they could make up what we need, and they answered in the affirmative.
  Since these items are all handmade, and since they use gold plated pins and tube sockets, I am sure they can make up sockets that are color coordinated to the MKIV. Just be careful; their store lists $1000.00 tubes! (Did not know that they exist - still shopping in the 99c stores LOL.)


----------



## MIKELAP

just bough 5 usaf  tunsol 6ah6wa for $5.00 a piece shipping included from California while im waiting for the sockets. And i am close to pulling the trigger on a pair of senns hd800 to go with the Conductor  waiting for more infos but pictures are really  nice


----------



## mordy

Dear Gibosi,
   
  I am trying to put together my impressions of the 5 different tubes I tried to audition. I have come to the conclusion that it is not a good idea to listen to two different tubes and A/B the channels using a good mono recording. The reasons are as follows:
   
  a) If one tube plays louder than the other, psychologically you tend to give it preference. It is very hard to adjust the volume for the other channel to be equal as you switch from A to B.
  b) If one tube is as day and one as night, meaning totally different, it is easy to pick a winner - "the difference is as day and night." But if the tubes are very similar, it becomes very difficult to pick the better one.
  c) Some tubes are much better in the bass than others, others excel in the mid range, and others in the treble. How do you compare them to each other?
  d) Even though the two channels in the Little Dot MKIII are completely independent, there may be a synergistic effect in playing two identical tubes. (In other words, the sum total is greater than the parts.) I have no scientific proof or sources for this, but nevertheless I think that this is the case.
   
  So, with all these caveats, I am going to try to rank the five different tubes, but take these ratings with a grain of salt.
   
  5) We will start with the loser: Tung Sol 6AV6 from the 50's-60's. Boomy bass, congested mid range, rolled off treble, lack of detail, dark. Maybe I got a bad sample; but I only have one tube. Anyhow, you remarked about these - at this stage I would not order them.
  4) and 3) shared: Sylvania JAN 8532 from 1970. Detailed, powerful bass, goes lower than any other tube in this group. However, the sound is not full      bodied but thin sounding.
                             Sylvania 6AV6 old side getter style. Good overall presentation, detailed, neutral with strong bass.
  2) Sylvania-Phillips 6AV6 late 70's early 80's tube with a little ring attached to the plate:  Very good and open presentation, bass not highly detailed but very good; rich treble, excellent overall.
  1) The winner: RCA 6AV6; Lively, up front, open, detailed and airy presentation. The bass is not overly powerful and detailed, and the treble is too bright and has to be turned down, but this tube is very engaging and nice to listen to. Did I mention that it plays the loudest of this bunch?
   
  Re the TS 6AH6WA tubes you ordered I think that you will be very pleased.
   
  While I am writing this I am listening the a pair of RCA 6BY6 tubes which are cousins to the 6BE6. These are quite nice and very realistic.
   
  Got some single tubes from a friend - 6DK6, 6BE6, 6AG5, 6AH6, 6AV6 and 6BY6. All are Sylvania except for the last one which is GE. Before I try these I am going to go back to my old favorites 6AH6 and 6AU6 and just enjoy the music - need a break from head ache inducing critical listening lol....


----------



## zedmeco

http://www.ebay.com/itm/1x-6AU6-to-6AK5-tube-adapter-socket-converter-/290917075011?pt=Vintage_Electronics_R2&hash=item43bc024843
   
  looks like they made them! going to order my two.


----------



## inphu510n

So awesome! I'm definitely going to order a set of the adapters!
  Thank you for pushing this creation forward!
   
  I'd love to come up with a design that would allow us to use a single jumper setting and use a switch or something on the side of the adapter to change which tube type you were adapting to.


----------



## gibosi

Hello Mordy,
   
  It's really too bad that your plan to A/B single tubes didn't work as well as you hoped. It seemed to be wonderfully efficient and elegant.... 
   
  As for me, I still am not able to listen to my TS 6AH6/6485 or the GE 6AU6/8425, and I am feeling a bit lost as I don't really have any "reference" tubes.... Soon, I hope....
   
  However, considering the three tubes we have in common, the Sylvania 8532, the Sylvania 6AV6 with side getter, and the RCA 6AV6, I would agree with your general assessment. The 8532 is the least bright, the least lively and the least upfront of the three, while the RCA is very bright, lively and up front. If it is true that the 6AV6 is one half of a 12AX7, then I can completely understand why the RCAs are so popular in guitar amps. This is one very hot tube. However, as I do not have access to tone controls, it is simply too bright for me. Of these three, the Sylvania 6AV6 with side getter would get my recommendation.  But still, if someone prefers a more laid-back presentation, with great bass, the 8532 is a very solid tube, IMHO. And for the ultimiate treble head, the RCA is pretty amazing. 
   
  However, I have just finished burning in Mullard CV5311 (8532/6J4), Mullard 6AV6 and GE 6AV6 and now I need to take the time to compare these to the three above.
   
  And presently, I am burning in GE 6BE6W/JG-5750 and next, RCA 6BY6/JRC-5915, perhaps similar to yours. And then, finally, I will try to sum up these, plus the 6 pairs of triodes! I hope I can survive such a "head-ache inducing critical-listening" marathon! lol
   
  (I have set the Mullard 6AQ4 aside for now. I have two more pairs coming, and will wait until they arrive. Besides, I think I have already bitten off more than I can comfortably chew!)


----------



## MIKELAP

Quote: 





zedmeco said:


> http://www.ebay.com/itm/1x-6AU6-to-6AK5-tube-adapter-socket-converter-/290917075011?pt=Vintage_Electronics_R2&hash=item43bc024843
> 
> looks like they made them! going to order my two.


 
  Wow they dont fool around.Now we wait.


----------



## Audiofanboy

You got to love how you can order metric tons of tubes over the course of a couple of weeks, not get a single package for like a month, and they suddenly all come at once... I woke up this morning to find out my package from the UK with 6 pairs of triodes, double diode-triodes and heptodes had arrived, so expect some reviews in the following days.
   
  Right now, I have the Sylvania 8532W burning in. At first, they seemed extremely detailed (possibly the best upper end detail extraction I've heard, again the finger snaps in M. Jackson's _Billie Jean_ are quite incredible), thinner sounding than my -reference- TS 6485, and with less strong and clear-cut bass (think same kind of balance as the CV4015 had, so quality bass, but dry and not exactly loud); so kind of a high quality polar opposite of the TS 6485 (or 6485 family for that matter).
   
  After 10 or so hours of burn-in, I can say these are excellent tubes, clearly more treble and upper-mids oriented than my balanced-sounding TS 6485 -at least on my system), maybe ever-so-slightly cleaner -too clean perhaps- and clinically precise. Pinpoint imaging, larger soundstage than the 6485 (but just as 3D-like, high and wide, you just get treble detail and decaying instruments going farther from your ears than with the 6485, if that makes sense), drier and not as musical, though they are evolving by the minute, with noticeably improving bass and more wetness (echoing and decaying notes flying between your ears in a room). Basically, right now, it's TS 6485 for musical pleasure and eargasms, and Syl 8532W for clinical precision. The comparison between both is actually pretty interesting.
   
  Next, out of my new 6 pairs are probably going to be my -beautiful to behold- Mullard UK mil-spec CV4070 (6AQ4/EC91 family, also known as M8099, mu=100 (!!); pure single triode, and also high transconductance, year 1972 so early; I just fail to see how these could be "bad"). Good luck finding those!
   
  Good god this is getting fun again, I keep thinking we're reaching a limit but I keep finding new and better tubes; only my wallet is clearly weeping, a three digit number -in euros- spent on tubes in the last month is just not OK...


----------



## gibosi

In light of AFB's glowing remarks regarding the Sylvania 8532W, I would like to further elaborate on my comments to Mordy regarding the Sylvania 8532W and the Sylvania 6AV6. The 8532Ws have been one of my go-to tubes since I first started listening to them over a month ago. However, I should note that my ears are very sensitive to high frequencies. I have a bit of tinnitus, and therefore, the slightest bit of peakiness, sibilance, or shrillness is quite uncomfortable. The thing I love about the 8532Ws is that their upper midrange and highs are very smooth, not a trace of sibilance or shrillness. And as AFB points out, the treble detail is superb. I have enjoyed many hours listening to these tubes. On the other hand, the Sylvania 6AV6 are just on the edge of being uncomfortably peaky for me, but I still quite enjoy them.
   
  I went to a local headfi meetup last weekend, and a fellow headfier, with considerably better gear and more experience than I, took an immediate interest in my LD and HE-300. I put the 8532W in first, and listening through the HE-300, he felt they were too dark. I then rolled in the Sylvania 6AV6 and he declared that these tubes were a perfect match for the HE-300. Then he switched to his headphones, a custom set of  Magnum v4 (in woodies with 5ft mogami quad cable and grado jumbo pads Sr80 Bowls) and immediately declared that the Sylvania 6AV6 were much too bright and sibilant. I then swapped the 8532W back in, and he was very pleased with what he heard. So in the end, it really does come down to different ears and different headphones/speakers....
   
  So I try to be cognizant of my sensitivity to high frequencies and careful in my recommendations. From my experience at the last headfi meetup, I think I can safely recommend the Sylvania 6AV6, but my personal preference is the 8532W.
   
  However, initial impressions of the Mullard CV5311 (8532/6J4) and the Mullard 6AQ4 leads me to think that the Sylvania 8532W just might have some stiff competition. And further, initial impressions of the Mullard and GE 6AV6 leads me to think that the Sylvania 6AV6 will not be my favorite 6AV6 much longer.
   
  I will report back after I have been able to spend more time with these new treasures.


----------



## mordy

Before changing the jumpers back from the the EF92 setting to the EF95 setting I decided to try two tubes that are just plug and play with this setting that I just got from a friend: Sylvania 6BE6 and Sylvania 6DK6.
   
  These are quite nice right out of the box with the 6DK6 being brighter and louder. At least they are both Sylvanias....
   
  I could go on with the galaxy swallowing sound stage, the shimmering endless decay highs, the book shelf rattling bass blah blah, but I think it is more prudent to wait for them to burn in...


----------



## MIKELAP

Quote: 





mordy said:


> Before changing the jumpers back from the the EF92 setting to the EF95 setting I decided to try two tubes that are just plug and play with this setting that I just got from a friend: Sylvania 6BE6 and Sylvania 6DK6.
> 
> These are quite nice right out of the box with the 6DK6 being brighter and louder. At least they are both Sylvanias....
> 
> I could go on with the galaxy swallowing sound stage, the shimmering endless decay highs, the book shelf rattling bass blah blah, but I think it is more prudent to wait for them to burn in...


 
  What eloquence im floored


----------



## Acapella11

Wow guys, loads of cool stuff our there. I am keenly waiting for your heptode impressions and probably gonna get a triode myself latest after this weekend. Fun. I will write a littlew up about the Syl 6AH6AW, which has been laying around a bit neglected while I had some fun trying different cables...
   
  Gibosi, It is really great you took your setup to a local meet. It is just so much more rewarding if one has the own setup there. Yes, Hi-Fi is like teamplay, if all fits together you win =)
   
  Mikaelap, Get that HD800. Lots of bucks. But it is amazing. Period.
  
  Mordy, "I could go on with the galaxy swallowing sound stage, the shimmering endless decay highs, the book shelf rattling bass" Please keep your review in that style, you are showing serious writer skills =)


----------



## Audiofanboy

Quote: 





gibosi said:


> In light of AFB's glowing remarks regarding the Sylvania 8532W, I would like to further elaborate on my comments to Mordy regarding the Sylvania 8532W and the Sylvania 6AV6. The 8532Ws have been one of my go-to tubes since I first started listening to them over a month ago. However, I should note that my ears are very sensitive to high frequencies. I have a bit of tinnitus, and therefore, the slightest bit of peakiness, sibilance, or shrillness is quite uncomfortable. The thing I love about the 8532Ws is that their upper midrange and highs are very smooth, not a trace of sibilance or shrillness. And as AFB points out, the treble detail is superb. I have enjoyed many hours listening to these tubes. On the other hand, the Sylvania 6AV6 are just on the edge of being uncomfortably peaky for me, but I still quite enjoy them.
> 
> I went to a local headfi meetup last weekend, and a fellow headfier, with considerably better gear and more experience than I, took an immediate interest in my LD and HE-300. I put the 8532W in first, and listening through the HE-300, he felt they were too dark. I then rolled in the Sylvania 6AV6 and he declared that these tubes were a perfect match for the HE-300. Then he switched to his headphones, a custom set of  Magnum v4 (in woodies with 5ft mogami quad cable and grado jumbo pads Sr80 Bowls) and immediately declared that the Sylvania 6AV6 were much too bright and sibilant. I then swapped the 8532W back in, and he was very pleased with what he heard. So in the end, it really does come down to different ears and different headphones/speakers....
> 
> ...


 
   
  Just one remark about the Syl 8532W, despite what I said about the treble detail. Like gibosi says, they have shown absolutely no sign of sibilance or shrillness, and that from the second I plugged them in. I may have younger ears, but shrillness, or any kind of harsh emphasis on high frequencies, just slowly kills me... It's the reason why I switched from the HE-400 to 500, and why I couldn't truly like the old Mullard EF91 mil spec types (CV4014 and CV5377).
   
  So, yeah, try some triodes, it's easy and fun, and a good yardstick to pinpoint where your preferences lie.
   
  Gibosi, now you've gotten me even more excited about trying my new Mullard CV4070 (6AQ4) tubes; I'm just etching to rip out the 8532W before they finish burn-in and try some new trans-tubed triodes... But I won't quite yet, since they're very interesting and unusual tubes too.


----------



## Nic Rhodes

Quote: 





acapella11 said:


> Mikelap, Don't worry. Great we agree =)
> Amazing, you got that socket sorted!
> 
> 
> ...


 

  I bought mine years ago from Billingtons, probably 50p but that shows how long I have been rolling now.  They were a common tube however and a search will reveal test subjects I am sure. Patience!


----------



## Acapella11

Off-topic: Audiofanboy, At the last London Head-fi meet, I compared HE-400 and HE-500 and I know what you mean. Both sound similar in a way but the HE-500 sounds more refined, that's the best summarizing word I could come up with at the moment. It is apparent in a "rounder", not as harsh and more detailed sound. You trade in some bass but overall for me the HE-500 sounded clearly superior.


----------



## gibosi

GE 6BE6W/JG-5750 manufactured in 1959. I can't help but notice how similar these look to the black plate GE 6AU6/6136....
   
  After burning these in for over 20 hours, I have come to the conclusion that these are very nice tubes. Again, as I am not able to listen to my 6AH6/6485 and/or 6AU6/8425/6136 at this time, I am feeling a bit handicapped.... 
   
  But the show must go on....  and actually, this is quite easy as it seems that I am hearing virtually everything in these GE 6BE6 that A11 has noted regarding his TS and Sylvania 6BE6
   
  "Airy, open, spacious representation, neutral.
  Treble: Extended, refined, not bright. Well resolved. 
  Mids: Quite sweet, round, clean.
  Bass: The bass quality is very good, well articulated and punchy.
  Stage: Large and wide
  Great detail against a black background."  (My apologies to A11. 
   
  But seriously, these are very nice tubes, and it seems that there is a strong sonic resemblance among the various brands of 6BE6. Further, I believe am hearing some of the same "amazingness" I remember hearing with the GE and TS 6AH6/6485 and the GE 6AU6/8425/6136 tubes.  
   
  I hope someone will decide to purchase both the GE and TS and do a shoot out! 
   
  And now, I am burning in a pair of RCA 6BY6/JRC-5915 manufactured in 1963.....


----------



## Johnnysound

Quote: 





hypnos1 said:


> Hi J,
> 
> Glad you were able to source the 6485s at such a good price - and to have someone match a pair is even better!
> I cannot wait until you try them, given your findings re the Voskhods...mine have done about 50 hours now, and combined with about 40 hours on a pair of early 6N30P-DRs I cannot believe what my ears  - and brain - are experiencing. I can only hope your setup (and you!) are  treated to something similar...
> ...


 
  Hi CJ, Gibosi, and many thanks to all for the accelerated (and free) course on  tube rolling ¡¡  I received my TS 6485s yesterday, nice NOS american tubes, I guess very old ones, looks like sixties stock.   After all my chat about matching, soldering, etc. I arrived late from work and simply could not wait and did the 2/7 jumper trick. It is true that this has to be done with twisted wire, but I felt that 26 AWG was a bit too thick, including the insulation,  so I rolled my own from bare copper filaments (¡¡) arriving at something a little thinner.  After some artistic work with little pieces of insulating tape, I got my custom jumpers,  perfect and tight fit with the tubes inserted.  I should sell them for $20 a piece.  Of course, we have to be patient and wait for a good burn in before any opinion about sound quality.  These tubes have been sitting for around 50 years, so at the minimun lets them awake and tell us what they can do. However, from the start it is obvious that the 6485s are good ones. To begin with, there is no background noise or microphonics, the detail is very good and have plenty of bass. Very promising...      
   .


----------



## inphu510n

So I'm beginning to think that my MKII doesn't like triode tubes. The two pairs I've tried had a slightly audible buzz/clicking on the right channel. Also I've noticed more microphonics and (I have no idea what the word is) proximity sensitivity. If I put my fingers near the right channel tube I hear a very audible buzzing/interference noise.
I switched in some older EF92's and there was no buzzing in the right channel.
I've tried both 6AV6 and 8532 tubes and they both exhibit some form of buzzing in the right channel.

I guess I'll have to upgrade to the MKIVSE. *sigh*


----------



## Acapella11

Quote: 





> Great detail against a black background."  (My apologies to A11.


 
   

  Gibosi, I feel honoured you are citing my words to reflect your own impressions  Seems the GE JG-5750 6BEW is a good one as well. Please, let me know which your favourite 6BE6/6BY6 tube(s) is (are) once you had the opportunity to listen to all of them. Just out of curiosity, which power tubes are you using?
  
  Inphu510n, I used your triode experience with the MKII in the tube guide table on page 77 and acknowledged you. Useful for every MKII tube roller. With respect to the potential upgrade: Look at it as a long term investment and you will be able to roll power tubes as well! Or sink all your money straight into DRs


----------



## gibosi

Quote: 





acapella11 said:


> Just out of curiosity, which power tubes are you using?
> 
> 
> Inphu510n, I used your triode experience with the MKII in the tube guide table on page 77 and acknowledged you. Useful for every MKII tube roller. With respect to the potential upgrade: Look at it as a long term investment and you will be able to roll power tubes as well! Or sink all your money straight into DRs


 
   
  I have the LD 1+. This is a hybrid amp, which uses tubes to "flavor" the sound and a solid-state op-amp for power. As the op-amp can be "rolled' as well, I guess my current "power tube" is an OPA2107. 
   
  The 1+ is a rather different kind of beast compared to the LD II, III and IV....
   
  Imphus510n. I seriously doubt that upgrading to a MKIVSE will "solve" this problem, as the problem is most likely just some faulty tubes. Any one who has rolled tubes for any length of time experiences this on occasion....
   
  (Now that said, if you really want to upgrade to a MKIVSE, this is as good an excuse as any!


----------



## inphu510n

Quote: 





gibosi said:


> (Now that said, if you really want to upgrade to a MKIVSE, this is as good an excuse as any!


 
   
  Definitely where I'm leaning. 
  It's also high time I upgraded my cans too. I just put in a Schiit Modi DAC and that helped smooth things out a bit though I know changing headphones is definitely going to change things dramatically.
   
  I have another set of Sylvania 8532's on the way and will give them a try.
  Indeed, one of the RCA 8532's that I was trialing last night was definitely less present than the other. It was as if parts of the song were missing from which ever channel the tube was placed in.
  Another thing I should note, the 8532's I tried last night did not have amazing pin contact. They slid into the socket much more easily than other tubes. I'm wondering if slightly bending or tweaking the pins might improve their connection. I'd already scraped the pins with an Xacto knife so it's not that.
  I have a pair of Ultron SQ 6AV6's and they had a similar issue with the right channel however less so than the 8532's.
  I'm definitely looking forward to the Sylvania 8532's. There were things I really loved about the Sylvania 6AU6WC tubes but the GE 8425's just took the cake. I still really love the 8425's. It doesn't hurt that Tektronix was/is located a few miles from where I live.
   
  I'm looking forward to re-trying some of the tubes I've collected once I get new headphones. Leaning towards Fischer FA-003ti's or Beyer 770 600ohm right now. We'll see. I was using this setup primarily at work where closed cans were necessary. I'm thinking I might just get a Fiio and some UE triple.fi 10's for work use. The MKII is definitely a conversation piece though I keep rolling so many tubes through it, it would get distracting at work.
   
  Anyhow, thank you all for your continued "hard work" and diligence in pushing the boundaries of this amp.
 I think once the eBay tube adapters arrive I'm going to walk into ALO Audio's store here in town with the adapters and a set of 8425's and see what their amp can really do. They're primarily pushing Voskhods with their tube amp but hehe, that tube can't compete.


----------



## Acapella11

Quote: 





gibosi said:


> I have the LD 1+. This is a hybrid amp, which uses tubes to "flavor" the sound and a solid-state op-amp for power. As the op-amp can be "rolled' as well, I guess my current "power tube" is an OPA2107.
> 
> The 1+ is a rather different kind of beast compared to the LD II, III and IV....


 
   
  Yes, should have checked your profile and of course you mentioned it before. My default thought goes to MKIII / MKIV(SE).
    
  Quote:


> Imphus510n. I seriously doubt that upgrading to a MKIVSE will "solve" this problem, as the problem is most likely just some faulty tubes. Any one who has rolled tubes for any length of time experiences this on occasion....


 
  I have kept everything in the table with respect to I+, MKII and III / IV compatibility. Let's see whether MKII triode issues come up again.


----------



## Johnnysound

become my go to tubes 
	

	
	
		
		

		
			





 Good stuff, and so far, (even) more impressive than the GE 8425 (6AU6 type). Tube code is 3227106-3, which I interpret as Tung Sol (thanks Mordy  ) and 6th week of 1971.
  
 Hi Acapella, still burning in the TS 6485s, but after a few hours I have to agree with you 100%,  excellent sounding tubes.  Clean, clear, detailed, open, great stage, nice bass.  Mine have a Tube code 322PW-1, no idea what it means...


----------



## mordy

Hi JS,
   
  I have tried to get a decoding sheet for the letter coding on the Tung Sol tubes, but no luck. The only thing I found was that these letter codes pre-date the numerical codes, meaning that these tubes probably are from the 50's and 60's. The last digit, which could be 1, 3 or 7, based on my experience, is a factory code.
  One of the reasons why so many tubes have obscure date codes is for business purposes. As you point out, tubes that are fifty years old and more, can perform like new. However, psychologically, the manufacturers figured that many people when buying tubes wanted fresh ones that were newly manufactured, thinking that they are better. So in order to allow the old stock to move off the shelves, they obscured the dates.
  Don't know myself why I just have to know when a tube was made. Perhaps the knowledge that some of the US made late 70's/early 80's tubes were poorer quality (for Russian tubes after the fall of communism in the 90's) is the reason.
   
  Just got a RCA 6J4 tube, which is the same type as the 8532 tube. The RCA date code is (I think, hard to read) MI, which means July 1961.
   
  Have not been able decode Sylvania letter date codes. Does anybody know?


----------



## Acapella11

So, I had a listen to the *Sylvania JAN 6AH6WA* and compared them to the *Tung Sol 6485* (6AH6 type), mainly because quite a few people have them already, they are great tubes and I do not have to change jumpers 
   
  Treble: The Sylvania has a well extended treble, non-fatiguing. In comparison to the TS 6485 it is not as clean though. The TS plays opener, airier, which makes the treble more engaging and fun. Importantly, the TS sounds also cleaner in the treble, which makes it more interesting.
  Mids: Round and sweet, this is probably where the Sylvania comes closer to the Tung Sol.
  Bass: More bass weight than the TS and also goes deeper. If your taste goes more towards bass, the Sylvania may be interesting. However, I find the TS bass tighter, better defined but this could be a result of the general signature difference with the TS sounding cleaner than the Sylvania.
   
  The Tung Sol sounds opener, more revealing, cleaner and has a deeper stage, which goes along with wetter sound. Also, I find the TS 6485 imaging is better. It is more neutral, where the Sylvania is sweeter and tubier.
   
  My vote goes for the TS 6485 between these two tubes.
   
 Then, I stuck in the *TS 6BE6*, for curiosity. Still, I am trying to figure out differences but it is often inhibited by the effort to switch two jumpers between every passage you want to compare. I think the general difference between these TS tubes is that the 6BE6 is more mid centric. Both tubes are neutral but the 6BE6 sounds somewhat rounder. The 6485 is brighter and harder (in comparison). This gives crunchier riffs, tighter bass, sharper treble. The 6BE6 is in comparison a more subtle imaging instrument with its strength in resolution and details using a larger stage than the 6485. I think if you can appreciate and hear all the "purity" of details over the clean background, if the gentler presentation suits your system and taste, the 6BE6 wins. If you like the sparkly 6485 sound and are not too much fussed about all these micro details or simply don't have the system to hear them, then the 6485 wins. I might revise some of this later again. But this my impression at the moment.


----------



## gibosi

RCA 6BY6/JRC-5915 manufactured in 1963/64. Mordy, do these look like your RCA 6BY6?
   
  After 20 hours plus of burn-in, the sonic resemblence of these to the GE 6EB6 is immediately apparent.  Like the 6EB6, these are very quiet tubes, revealing "great detail against a black background". 
   
  I would guess that as these tubes were often used to modulate and/or demodulate two separate signal streams, they would have to have very low noise and be very clean and neutral by design. And as these heptodes were often used to demodulate an FM radio signal down to audio, it is not unreasonable to conclude that they were also designed to faithfully process audio frequencies. 
   
  These heptodes are a great find, I think.
   
  Again, borrowing from A11's description of the 6EB6:
   
  Airy, open, spacious representation, neutral.
   
  Check.
   
  Treble: Extended, refined, not bright. Well resolved. 
   
  Check. But I think the RCA is a just a tiny bit brighter...
   
  Mids: Quite sweet, round, clean.
   
  Check. For both, vocals, horns and other acoustic and percussive instruments sound very natural
   
  Bass: The bass quality is very good, well articulated and punchy.
   
  Check. Both of these tubes have very good bass, strong, deep and punchy.
   
  Stage: Large and wide
   
  Check. Both of these tubes have a large, wide and deep sound stage, very realistic to me.
   
  After spending a couple hours A/B-ing these tubes, I am a bit  embarrassed to say that my old ears could not reliably differentiate between these tubes. I am quite sure there are differences, but I believe they are very subtle.... 
   
  Again, "great detail against a black background". What really stands out in my mind for both of these is the amount of low-level detail revealed in my favorite recordings. It is kind of mesmerizing....
   
  And perhaps it is not so bad that I can't pick a clear winner in that I can recommend both of these tubes without reservation.


----------



## Acapella11

Gibosi, Sounds very interesting. Thanks for the detailed description and it is good to read that you have similar impressions. Sometimes, if you keep comparing too much, I find, differences start to blurr. Fresh ears are a plus and also being actually in the right mood, because then, at least I, remember differences better. From your write up it seems the RCA 6BY6 would be brighter, but only a little. "A little brighter" sounds good to me. Should hear some 6BY6 tubes.


----------



## hypnos1

Hi Johnnysound,
  Glad you're discovering how good the TS6485s are - just wait 'til further burn-in! I can't thank the guys here enough for extolling their virtues, especially audiofanboy for placing them at the top of his list some while back. To my mind they are producing a coherence of sound that transcends a merely good 'balance', plus of course an amazing clarity.  It creates an experience that,as mordy states, is one of sitting back and just enjoying the music, rather than analysing/evaluating what is producing it. This has hit me especially with some (nay most) of the tracks on ELOs 'Out of the Blue' album, where in the past my equipment - and my ears - had great difficulty 'disentangling' some rather complex sound creations in said album. Now I can with great glee appreciate the incredible feat of mixing the engineer achieved, some years ago now...WOW!!!
   
  Mordy, I am wondering how things are coming along with your 6DK6s. Have acquired some RCAs, and as you mentioned the Sylvanias being bright I hope I haven't wasted my money on a brand that could be even brighter - although it appears sometimes RCAs can really come up with the goodies?
   
  Re. the socket savers what a marvellous achievement guys. I look forward to hearing whether adding another link into the signal chain causes any degradation at all - am the eternal pessimist, I'm afraid! But it does look like they are a good outfit...BTW, I emailed them for dimensions and apparently the diameter is about 1.7cm.


----------



## mordy

Hi G and all,
   
  Here is my pair of RCA 6BY6 from Oct 1966. They have Gray plate and thus look different from your 5915 tubes.
   

   
  Here is a picture of my newly acquired RCA 6J4 tube. There is a beautiful orange glow reflection from the heater at the bottom of the tube. I am running it together with the Sylvania 8532 tube, and they seems quite compatible with similar sound signature.
  Somebody had complained that they had problems with microphonics with the 6J4 tube, but even tapping it directly with my finger their is no untoward noise.
   
  Somebody had mentioned microphonics. Here is a definition from Wikipedia:
*Microphonics* or *microphony* describes the phenomenon wherein certain components in electronic devices transform mechanical vibrations into an undesired electrical signal (noise). The term comes from analogy with a microphone, which is intentionally designed to convert vibrations to electrical signals.
 When electronic equipment was built using vacuum tubes, microphonics were often a serious design problem. The charged elements in the vacuum tubes can mechanically vibrate, changing the distance between the elements, producing charge flows in and out of the tube in a manner identical to a capacitor microphone. A system sufficiently susceptible to microphonics could experience audio feedback, and make noises if jarred or bumped. Certain vacuum tubes were made with thicker internal insulating plates and more supports to minimize these effects

   
  The 6J4/8532 tubes sound great. It is true that there is no sibilance, but I have the luxury of having tone controls, and even it seems that Sylvania tubes may have a family trait of being bright, it is easy for me to moderate it with the treble control.
   
  About the difference between the Little Dot MkIII and MkIV I believe that it is minimal and mainly cosmetic. When I asked David Zhe Zhe he did not seem to think that the MkIV had a sonic advantage over the MkIII.


----------



## MIKELAP

Dont know if this is of interest related to Sylvania tubes                     http://pax-comm.com/pa01039.htm                                                 http://www.audioasylum.com/cgi/vt.mpl?f=tubes&m=242045


----------



## gibosi

Quote: 





mordy said:


> Here is a picture of my newly acquired RCA 6J4 tube. There is a beautiful orange glow reflection from the heater at the bottom of the tube. I am running it together with the Sylvania 8532 tube, and they seems quite compatible with similar sound signature.
> Somebody had complained that they had problems with microphonics with the 6J4 tube, but even tapping it directly with my finger their is no untoward noise.


 
   
  I also had a problem with microphonic RCA 6J4. You might remember that I had a pair of Motorola 6J4, rebranded from RCA (post #1048, page 70) and one of them was microphonic. But looking on the bright side, only one of them was bad, so perhaps I should send you the good one and then you will have a good pair?


----------



## rosgr63

Quote: 





mikelap said:


> Dont know if this is of interest related to Sylvania tubes                     http://pax-comm.com/pa01039.htm                                                 http://www.audioasylum.com/cgi/vt.mpl?f=tubes&m=242045


 
   
  Thanks for the link.
   
  Why did Sylvania use the Leaf logo?


----------



## halflife78

Wow, bored in a hotel and wandered into this section and found this thread. My Dad has been selling tubes for a few years now, it's cool visiting home and seeing his wall of tubes and the radios he has rebuilt. He said the Chinese have went nuts lately as 40% of his sales come from China now.


----------



## inphu510n

Scratch the notes about MKII issues. I'm beginning to think it's something wrong with my amp.
  I put in a pair of previously silent GE 6676 tubes from a few months back and the right channel is still experiencing some level of buzzing.
  I think I'm going to contact Little Dot about servicing this animal. I just need to make sure it happens reliably with EF91/92 tubes.


----------



## MIKELAP

Quote: 





rosgr63 said:


> Thanks for the link.
> 
> Why did Sylvania use the Leaf logo?


 
  It looks like an oak leaf and where do you see oak leafs you see them alot on military decoration  .[size=small]Historically, the oak leaf[/size][size=small] is a symbol [/size][size=small]of endurance and strength. [/size]


----------



## mab1376

For 6AH6 tubes I need to strap pins 2 and 7, what the best method? Should I strap the socket or the tube itself.
   
  has anyone made an adapter? If so how can I get a hold of one?
   
  Anyone have any pics? I just ordered a pair of TS 6AH6WA.
   
  I've been using a pair of Raytheon 6GX6 with 6N6P-IR power tubes which is a great combo.


----------



## gibosi

In today's mail, I received two more pairs of 6AQ4, triodes, bringing my total to three pairs:
   

   
  I received these about a week ago. They were manufactured in the Mullard Whyteleafe "A" factory in 1960. Notice the "Old World" D-getter. AFB tells me that this was kind of an experimental factory that made specific tube types in the 50s and into the early 60s. Eventually manufacture of these tube types was shifted to the Mitcham factory.
   

   
  And sure enough, these Philips tubes were manufactured in the Mitcham factory in 1973. AFB's CV4070/6AQ4 were also manufactured in this factory at about the same time. Notice the O-getter
   

   
  And a pair of Sylvania. I thought these looked very similar to the Philips, but still, imagine my surprise when I examined the tube codes and discovered that these too were made in the Mullard Mitcham factory in 1969!
   
  These 6AQ4 proved quite difficult to find. In fact, I couldn't find any on eBay, and had to dig deeper into Google search to find other sources. In the end, I bought these sight unseen, knowing only the brand. I am a bit disappointed that the Sylvanias are in fact Mullards, but in the end, I think I got some pretty nice tubes. 
   
  Now to find out how they sound.... Time to cut some pins and start burning....


----------



## gibosi

Quote: 





mab1376 said:


> For 6AH6 tubes I need to strap pins 2 and 7, what the best method? Should I strap the socket or the tube itself.
> 
> has anyone made an adapter? If so how can I get a hold of one?


 
   
  See Acapella's chart on page 77. There is a picture and directions on using a small stranded wire to strap pins 2 and 7 in the socket. Currently, this is what the vast majority of us are doing. That said, a number of people have ordered a set of socket converters to allow 6AU6, 6AH6 and simlar tubes to be plugged directly into our 6AK5 sockets with no wires. However, to my knowledge, no one has received these yet.
   
  http://www.ebay.com/itm/1x-6AU6-to-6AK5-tube-adapter-socket-converter-/290917075011?pt=Vintage_Electronics_R2&hash=item43bc024843
   
  My advice is to use a small wire for now, and wait until we have some feedback on these socket converters.


----------



## Audiofanboy

I had taken some pictures of my most recent triodes but forgot to ever post them...
   
  So, here's the CV4070 (6AQ4) I got the other day, Mullard Mitcham-made, 1972, mil-spec, very clean looking. I gave these 20 hours of burn-in and found them to be very nice tubes, with great micro detail and extension but dry and lacking the kind of musicality and "magic" that I get with my favorite TS 6485. These are the loudest tubes I've tested since the EF91 family (mu=70) with a mu of 100 (a 6AK5 is 20, and even a 6J4 triode is 50, so we're pretty far from the original specs here). Anyway, I might give these a try again at a later point since they have such interesting characteristics, but for now I need to relax with "tubier" tubes lol... Like gibosi said, 6AQ4/EC91 are _hard_ to find, and these are just as hard to get. They look the exact same as gibosi's Philips and Sylvania Mullard-Mitcham-made 6AQ4 btw.
   

   
  Here are the new tubes I'm now burning in over some even newer Daft Punk music. CV5311, so "selected mil-spec" Mullard tubes (CV5xxx are supposedly selected CV4xxx, themselves mil-spec Mxxx, themselves premium EFxx on which the older CVxxx were based... Actually was able to test that back in my EF91 adventure days, where for example: EF91 < "EF91/6AM6"  < or = "6AM6/CV138" < M8083 = or < CV4014 < CV5377; and the CV4014  -or some CV4xxx types in general- were manufactured either in Whyteleafe in early days and in Mitcham in later times, which further complicates understanding the "hierarchy" of UK/Mullard tubes; in my experience though Mitcham-made (usually with O-getters) tubes were superior to (usually D-getter) Whyteleafe which were good but just different (larger and drier), at least for the EF95 and EF91 families where I tested it myself), Mitcham-made, so basically the best you _should_ be able to get out of UK NOS tubes, but mil-spec or rugged doesn't always mean good-sounding as we've experienced.
   
  At any rate, these are nicer on the ear than the French 6J4S I'd tried and the aforementioned CV4070. Interestingly, these have very loud volume -closer to EF91 or 6AQ4 high-mu types than other 6J4 triodes, even the Sylvania 8532W I tested but never reported on, or did I? I forget... They are also very bright-looking and light up like the 6AJ5 did, and are built like tanks, which makes me think that they are indeed very ruggedized and made largely over specifications -robust cathodes and heaters- to keep their characteristics after 1000-2000 hours. Right now, they definitely seem to have more "power" than they should...
   

   
  Telefunken EH900S (6BY6 type), no diamond-on-the-base or gold pins, German "eagle" military symbol (strange...), USA label (stranger...), made in '77 _somewhere_; I have no idea who really made these and how they'll sound, but the boxes were definitely Telefunken.


----------



## mab1376

Quote: 





gibosi said:


> See Acapella's chart on page 77. There is a picture and directions on using a small stranded wire to strap pins 2 and 7 in the socket. Currently, this is what the vast majority of us are doing. That said, a number of people have ordered a set of socket converters to allow 6AU6, 6AH6 and simlar tubes to be plugged directly into our 6AK5 sockets with no wires. However, to my knowledge, no one has received these yet.
> 
> http://www.ebay.com/itm/1x-6AU6-to-6AK5-tube-adapter-socket-converter-/290917075011?pt=Vintage_Electronics_R2&hash=item43bc024843
> 
> My advice is to use a small wire for now, and wait until we have some feedback on these socket converters.


 
   
  Thanks, I'll see if I can give it a shot later, I have some 6AU6 tubes I haven't tested yet.
   
  I also ordered the converters, but coming from Hong Kong I'll expect it to take about 2 weeks.


----------



## mordy

Hi G,
   
  The "blue glass" is a Mullard give-away - I don't think anybody else made tubes with this feature. In addition, those little round plastic pin protectors were only included with Mullard tubes and an Australian Mullard clone that was inferior in quality.


----------



## gibosi

Mordy, I didn't know that blue glass is an indication of Mullard manufacture. Back when I was rolling 5654 tubes, I wondered where these RTC 5654RT were made. As I understand, RTC was a French company that made some of their own tubes and rebranded others. However, I cannot find any manufactureing codes on these, so they have remained a bit of a mystery. So now it appears that these were likely made by Mullard?  But they sure don't look like any Mullard EF95 I have ever seen....
   
  Oh, and none of these 6AQ4 came with those little plastic pin protectors... Maybe only Mullard CV series tubes came with these?


----------



## mordy

Hi Mikeleap,
   
  Thanks for the links. The third link provided the most information. One of my Sylvania tubes has a letter code L7V. The first letter is the month, with A being January etc. The second number is the last digit of the year it was made, and the V is a code for a Sylvania factory. So L7V translates into December 1957/1967 (take your pick) made in the V factory. Sometimes the letter "I" was discarded in a sequence since it looks too much like the number 1; then this tube would be made in November.
   
  Other Sylvania tubes I own have the designations CH, ke     and ak         etc.
                                                                                     ARK        JBB
   
  If anybody can decipher these letter combinations, please let me know. All the above tubes come in the same old style Sylvania yellow boxes.
   
  Here is a chart that explains the different colors on the box flaps and tube print. One of my Sylvania 6AV6 tubes has red print instead of black print on the box flap, and the tube has red print. Oops, no warranty!
   

   
   
  [size=large]TUBE WRITING COLOR[/size]
 [size=large]BOX FLAP WRITING[/size] [size=large]MEANING[/size] Yellow Black Standard Sylvania Warranty Red/Orange Red Distributor Warranty Only
 Syl sells to dist for less
 Sylvania absolved of warranty Green Mil Box: Black
 Export Box: Unknown Military or Export
 No Standard Warranty The above table applies only to the Yellow boxes. In the old Green box days, standard writing was usually green.
 The newer Philips/ECG tubes usually had blue writing.


----------



## Audiofanboy

Quote: 





gibosi said:


> Mordy, I didn't know that blue glass is an indication of Mullard manufacture. Back when I was rolling 5654 tubes, I wondered where these RTC 5654RT were made. As I understand, RTC was a French company that made some of their own tubes and rebranded others. However, I cannot find any manufactureing codes on these, so they have remained a bit of a mystery. So now it appears that these were likely made by Mullard?  But they sure don't look like any Mullard EF95 I have ever seen....
> 
> Oh, and none of these 6AQ4 came with those little plastic pin protectors... Maybe only Mullard CV series tubes came with these?


 

 Gibosi, Mordy, RTC was part of the Philips -and therefore Mullard- group which may have shared technologies and definitely tubes between European plants. Although I have never seen EF95 tubes with blue glass, it doesn't seem illogical either, since the whole purpose of the process -like carbon-colored or silver glass- was to absorb the stray electrons that would otherwise make the glass more fragile over time. While the "blue" trait seems to be tied to Mullard, I'm not sure we can actually trace it back to a specific pattern in Philips tubes; it seems to just have been "selected" as a specification for some tubes made in Philips factories. Most Mullard EF91 types had blue glass until the 80s and mysteriously lost it afterwards, my CV4070 (6AQ4/EC91) and old-world EC91 have blue glass, and other similar Mullard signal tubes have it as well without any reason I can understand (on pentodes such as EF91, screening make sense, since the anodes don't cover the hole surface where electrons are sent from the cathode -hence the suppressor grid and blue or silver glass that "catch or absorb them- but on triodes like the 6AQ4/EC91 or 6J4 the anode literally encircles the cathode very close, so few electrons should be able to get through, and we still find blue or grey glasson some tubes).
   
  So, basically, I wouldn't necessarily count on the blue glass trait or pin protector trait to determine a tube's manufacturer. Factory codes, on the other hand, are a pretty fail-safe way to know for sure, as gibosi pointed out for his "Sylvania" 6AQ4.


----------



## mordy

Hi Folks,
   
_From the Oddly Enough column:_
   
  Came across a new use for old tube boxes:{$9.99 + $4.50 ship}
   
  http://www.ebay.com/itm/2-Mullard-10M-Master-Series-EF86-6267-Tube-Boxes-Boxes-Only-No-Tubes-/261215479436?pt=Vintage_Electronics_R2&hash=item3cd1a7e68c
   
   
   
  BTW, Mullard Millenium tubes was the British answer to Sylvania Gold Brand, GE 5 Star and Russian DR tubes which were all engineered to last around 10,000 hours.
   
  OK, I found one Raytheon blue glass 5654/EF95 tube. (Made in France by RT=Mullard)
   
  http://www.ebay.com/itm/1-x-Raytheon-5654-EF95-tube-made-in-France-Black-plate-Blue-smocked-glass-/380415849529?pt=Vintage_Electronics_R2&hash=item58928d3439
   
   
  Other makers of blue glass tubes were Tesla and Arcturus, but here the glass is all blue, and not a band like the Mullards.
  http://www.ebay.com/sch/i.html?_trksid=p2047675.m570.l1313.TR0.TRC0&_nkw=Blue+glass+vacuum+tube&_sacat=0&_from=R40
   
  Have fun!


----------



## gibosi

Quote: 





mordy said:


> OK, I found one Raytheon blue glass 5654/EF95 tube. (Made in France by RT=Mullard)
> 
> http://www.ebay.com/itm/1-x-Raytheon-5654-EF95-tube-made-in-France-Black-plate-Blue-smocked-glass-/380415849529?pt=Vintage_Electronics_R2&hash=item58928d3439


 
   
  I think the mystery is solved! As RTC was part of the Philips/Mullard group, it does appear that these blue 5654s were manufactured in one of their factories somewhere in Europe. Thanks!


----------



## gibosi

6AV6 Shootout
   

   

   

   

   
  The two winners of my shootout are the GE and Mullard. Although to be truthful, the Sylvania and RCA were just too peaky in the highs for me, and didn't stand a chance. lol
   
  The GE is just a bit brighter than the Mullard, but again I think this is mostly a matter of personal preference. I like both of these tubes very much, but if I have to choose, my old ears prefer the slightly softer Mullard.
   
  Both the GE and the Mullard are "old world" tubes with D-getters. The GE are dated 1958 and the Mullard are dated either 1957 or 1967. The tube codes are B7A and B7B. The beginning B = Mullard Blackburn factory, 7 = year, and A or B = January or February. The fact that these appear to have been marketed expressly for sale in the US leads me to think 1967, but of course, this is just a WAG on my part.
   
  Both of these triodes are a good bit brighter and more forward than the recent 6BE6/6BY6, or the CV4015, my favorite "traditional" tube. But with a lively, detailed and airy presentation, up-front vocals and a good solid bass, these are both very nice tubes. 
   
  As seems typical with triodes, I think both of these are dryer than the best pentodes, such as the TS 6485 and the GE 8425, but for me they are not so dry that I can't enjoy them. And I think this is likely more a matter of preference, than a deficiency.
   
  In the end, I enthusiastically recommend the 6AV6 tubes. They are fairly inexpensive, and like the 6AK5, the sound signature varies considerably among the various brands. While I prefer the GE and Mullard, I am sure others will prefer either the Sylvania and RCA, and there are a number of other brands out there to trial as well.


----------



## mordy

HI AFB,
   
  You did review the Sylvania 8532 tubes and this is what you said (excerpts):
  "Extremely detailed, thinner sounding and with less strong and clear-cut bass; drier and not as musical.... clinical precision."
   
  I agree with all the above completely. After switching to a pair of Tung Sol 6CB6 tubes, I took a sigh of relief. It was like listening to a great sounding 78rpm analog recording that had been perfectly re-mastered, compared to a thin sounding digital CD recording.
  The 8532 may have the most precise treble, but the mid range is thin and unfulfilling, and the bass is weak - not for me. I gave these tubes a fair chance with around 30 hours burn in, but now I have made up my mind. They may work well in a different system, but this is not my cup of tea.
   
  The TS has a meaty punchy presentation with great bass and galaxical sound stage (A11 knows), and that suits me much better. Funny thing, when I first listened to the 6CB6 tubes I used the EF95 setting with the 2-7 strap and did not like the sound. Now I consulted the excellent chart (thanks Acapella11) and used the EF92 setting. What a difference! (BTW, just noticed the the TS tubes run quite hot.)
   
  When I gather up enough energy I am going to gingerly change the jumpers to EF95 and put back my little 2-7 straps and go back to listening to the great 6AH6 and 6AU6 families. Wonder who is going to be the winner?


----------



## mordy

Hi G,
   
  "The Sylvania and RCA were just too peaky in the highs for me and did not stand a chance."
   
  Have you entertained the idea of introducing tone controls in your system? I find that I can make many bright tubes enjoyable by turning down the treble. Perhaps the ranking order would change if you had a pleasant treble?
   
  If I remember correctly, there were posts that 6N6P power tubes would tame the highs as well.


----------



## Audiofanboy

Ok, after spending the last 3-4 days playing around with triodes, I am taking a break from them for a little bit, and letting my amp also take a break from burn-ins.
   
  The CV5311 after 17-18h of burn-in (couldn't force myself to go any further...) showed some very nice characteristics, with some of the best upper end detail I've ever had, only bested in that regard by the Sylvania 8532W, cristal clear highs at any rate. The CV5311 were the least "dry" and "thin" of the triodes I tested, but still ultimately lacked those magical echo-like effects and the liquidity that make "tube realism" what it is and music magical and musical -like with the 6485 or the best pentodes. I am going to choose to just not grade the triodes like all the other tubes I tested, since I -and that's saying a lot- can't truly compare them to pentodes as they just sound so different, and almost feel like they were made for other purposes like monitoring instead of pleasure listening (i.e. extra-detailed and revealing and not necessarily musical). But they do work very well on some music genres and movies, since they make dialogues and sound effects very clear.
   
  On a more general note, all the triodes I tested had some specific traits in common, which is weird, since they were from different countries, brands and types: slightly thin and dry as I've mentioned (mostly "un-wet" not always thin or fleshed-out), treble-oriented -or at least a bit mid-recessed since some had good bass- and quite forward (sounds that were meant to be in the background or just heard as random echoes kind of leap at you from the sidelines almost as loud as the singer or guitars, at first it sounds like extra detail but it just doesn't feel natural because it's all you notice).
   
  So, although I _really_ want to go back to the TS 6485 for few days, I still tested the different heptodes I got in the meantime. No 20 hour burn-in this time, as I don't believe it dramatically _changes_ the sound or the nature of the tube, but merely lets it mature and improve, often massively (after 2-3h, I can virtually always tell if I, both, like a tube's signature, and whether or not it's worth my time, after 20-30h, I can be sure and also see if it's evolved a lot or not), and I just can't add 100s of hours of use on my amp just for the sake of burn-in...
   
  Telefunken 5915/EH900S (6BY6), most likely _Sylvania 5915_ (think Sylvania JAN 5915) made for the German military -I hadn't paid attention to obvious mil tags on the boxes and eagle symbol on the tubes- and boxed by Telefunken, very nice tubes, open and forward sound, slightly mid-oriented (not treble-oriented at any rate) that somewhat reminds me of the 6GX6/6GY6. Ultimately, I find these to have the same "bring stuff from the background and throw it at your face as loud as the singer" effect that I just don't like that much as it makes music unnatural. If you love the 6GX6, you'd absolutely love those, as they sound similar but much better and less coarse. Less loud by a small margin than my typical tubes and comparable to a 6GX6 in that regard.
   
  Brimar CV4012/5750/6BE6 (yes all three are written on the tube), different and more balanced the Tele/vanias above, less forward but still not as well voiced as my best pentodes. Nice large and deep soundstage, thick and heavy Brimar bass but much better that the other Brimar pentodes I'd tested when back when -would most likely improve quite a bit after burn-in. If you like cavernous, balanced and good separation that sounds natural but still close to you (though not forward like some of the previous tubes), you'd like those. Again, these have a little bit of that 6GX6 flavor that's so difficult to describe. Not sterile sounding at any rate, but more "analog" like I'd described the 6GX6. These are possibly the best of the recent batch, including the triodes, even though (or perhaps because) they don't have the most detail and sound the most "normal".
   
  I actually have two pairs of the last tube type, if anyone's interested, as the Mullard 6BE6W I ordered turned out to be "Mullard" named but Brimar-made CV4012/6BE6W dual labeled. Actually, if anyone's interested in _any _of the tubes I've recently reviewed and don't seem to be actively using, don't hesitate to PM me, I have tons, and often more than one pair.
   
  Next -and last for now- are my Pinnacle 6AV6/EBC91 that look like no tubes on google, but that can't be that old since their side-getter is an O-getter.


----------



## mab1376

Quote: 





audiofanboy said:


> Telefunken 5915/EH900S (6BY6), most likely _Sylvania 5915_ (think Sylvania JAN 5915) made for the German military -I hadn't paid attention to obvious mil tags on the boxes and eagle symbol on the tubes- and boxed by Telefunken, very nice tubes, open and forward sound, slightly mid-oriented (not treble-oriented at any rate) that somewhat reminds me of the 6GX6/6GY6. Ultimately, I find these to have the same "bring stuff from the background and throw it at your face as loud as the singer" effect that I just don't like that much as it makes music unnatural. If you love the 6GX6, you'd absolutely love those, as they sound similar but much better and less coarse. Less loud by a small margin than my typical tubes and comparable to a 6GX6 in that regard.


 
   
  Where did you buy these from? I really like my Raytheon 6GX6 tubes and i'd like to try em out.


----------



## halflife78

Just got home from traveling so I thought I would share some pics.
   
  Dad's personal tube museum.

   

   
   
  Some of his radios.  He buys them and rebuilds, refinishes, retubes them.

   

   
   
   
  His tubes he sells.  He has them catagorizes in some way I'm not sure of.

   

   

   
   
  Some of his testing gear to make sure the tubes work.


----------



## gibosi

Quote: 





mordy said:


> Hi G,
> 
> "The Sylvania and RCA were just too peaky in the highs for me and did not stand a chance."
> 
> ...


 
   
  I have a LD 1+, which does not have pre-amp out jacks. I can't think of any way to introduce tone controls without pre-amp out? Moreover, the 1+ is a "hybrid" amp, driver tubes with a solid state amp, so can't use a 6N6P....
   
  And actually, it wasn't until I started testing triodes that I encountered tubes with highs that were just too peaky for comfort. So in the end, it is easiest just to avoid these few tubes. After all, it is not as I am having trouble finding tubes that I like.


----------



## gibosi

Quote: 





audiofanboy said:


> (sounds that were meant to be in the background or just heard as random echoes kind of leap at you from the sidelines almost as loud as the singer or guitars, at first it sounds like extra detail but it just doesn't feel natural because it's all you notice).


 
   
  This description hits the nail on the head. With some of these very bright triodes, it was often startling to hear what seemed to be background sounds almost as loud as the singer. And yes, I just thought it was extra detail, but now that you mention it, it is quite strange....


----------



## gibosi

Quote: 





halflife78 said:


> Just got home from traveling so I thought I would share some pics.


 
   
  Thanks for sharing these pictures. Your father has put together quite a nice "man cave". Makes me think I would like to do something like this someday.


----------



## mordy

Hi halflife78 (39?),
   
  Your Dad looks to be super organized! I would not dare show pictures of my "man cave". Suffice to say that I need a clock to find something on my desk. With that I mean is that if I need something I know that it is around 3 o'clock on my desk two inches down under some stuff.
  The problem I have is that if I clean up and organize everything, I cannot find what I need......LOL


----------



## john57

Quote: 





mordy said:


> Hi halflife78 (39?),
> 
> Your Dad looks to be super organized! I would not dare show pictures of my "man cave". Suffice to say that I need a clock to find something on my desk. With that I mean is that if I need something I know that it is around 3 o'clock on my desk two inches down under some stuff.
> The problem I have is that if I clean up and organize everything, I cannot find what I need......LOL


 
  same here!


----------



## Audiofanboy

Quote: 





mab1376 said:


> Where did you buy these from? I really like my Raytheon 6GX6 tubes and i'd like to try em out.


 

 I can't guarantee that they're very similar to your 6GX6, but they definitely called up memories of the same sound signature (a little analog sounding and forward). Those and the CV4012/6BE6W actually. They're virtually the same tube type, so it isn't exactly surprising.
   
  I ordered them and all my last batch from some very obscure UK company called Chelmer Valve Company or CVC. You basically can only search for tubes yourself in their huge database to which you don't directly have access (all you can do is type characters in a box and results appear), no pics, no descriptions, just obscure tube codes -did I mention the whole process is quite obscure? Anyway, just look for them on google if you want to know more. The tubes cost me something like 6 euros each + VAT and fairly expensive shipping, so leveled out with the other tubes, a solid 8 euros per tube (most of the tubes in my last order did). The whole ordering process with CVC took about 8-9 business days + shipping time (close to three weeks total with shipping UK -> France; so a bit tedious for a basic tube order if you ask me...).
   
  Again PM me if you're interested in the pair(s) I have, as I'd be happy to give them a new home, where they'll get more love -now that I've figured out how to send stuff from France to anywhere in the world for pretty cheap, unlike the other way around...


----------



## mab1376

Quote: 





audiofanboy said:


> I can't guarantee that they're very similar to your 6GX6, but they definitely called up memories of the same sound signature (a little analog sounding and forward). Those and the CV4012/6BE6W actually. They're virtually the same tube type, so it isn't exactly surprising.
> 
> I ordered them and all my last batch from some very obscure UK company called Chelmer Valve Company or CVC. You basically can only search for tubes yourself in their huge database to which you don't directly have access (all you can do is type characters in a box and results appear), no pics, no descriptions, just obscure tube codes -did I mention the whole process is quite obscure? Anyway, just look for them on google if you want to know more. The tubes cost me something like 6 euros each + VAT and fairly expensive shipping, so leveled out with the other tubes, a solid 8 euros per tube (most of the tubes in my last order did). The whole ordering process with CVC took about 8-9 business days + shipping time (close to three weeks total with shipping UK -> France; so a bit tedious for a basic tube order if you ask me...).
> 
> Again PM me if you're interested in the pair(s) I have, as I'd be happy to give them a new home, where they'll get more love -now that I've figured out how to send stuff from France to anywhere in the world for pretty cheap, unlike the other way around...


 
  OK cool, Thanks!
   
  I found this site: http://www.audiotubes.com/bjtubes.htm
   
  they have:
   
 *6CS6 / EH900S Telefunken gold pin low noise, 10,000 hr. rated life, original box, $15.00*   
  Not sure if the 6BY6 is similar to the 6CS6, they also have these:
   
 *EH900S Telefunken goldpin, low noise $25.00*   
  It's not clear if these at 6BY6/5915 type either.


----------



## Audiofanboy

Quote: 





mab1376 said:


> OK cool, Thanks!
> 
> I found this site: http://www.audiotubes.com/bjtubes.htm
> 
> ...


 
   
  These would be "true" Telefunken tubes, most likely with the "diamond in the base" that people always look for. EH900S are definitely 6BY6 types though, so their might be a mistake on the first one, as 6CS6 have a lower heater current than both the -similar- 6BY6 and 6BE6.
   
  Both are different from mine, which is a US-made German mil-spec Sylvania 5915/6BY6, as odd and twisted as it may seem... Then again maybe not that odd, as we've seen a number a rebrands in the last couple of pages.
   
  Edit: $25 is pretty expensive now that I think about it; I'm pretty sure I saw those cheaper on ebay.


----------



## gibosi

While not gold pins, these might be worth looking at:
   
  http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=400405173654&ssPageName=ADME:B:BODO:US:1
   
  However, I think almost $11.00 for shipping is a bit excessive....


----------



## mab1376

Quote: 





audiofanboy said:


> These would be "true" Telefunken tubes, most likely with the "diamond in the base" that people always look for. EH900S are definitely 6BY6 types though, so their might be a mistake on the first one, as 6CS6 have a lower heater current than both the -similar- 6BY6 and 6BE6.
> 
> Both are different from mine, which is a US-made German mil-spec Sylvania 5915/6BY6, as odd and twisted as it may seem... Then again maybe not that odd, as we've seen a number a rebrands in the last couple of pages.
> 
> Edit: $25 is pretty expensive now that I think about it; I'm pretty sure I saw those cheaper on ebay.


 
   
  Had to use google to pick it up on the UK ebay: http://www.ebay.co.uk/itm/1-NOS-NIB-TELEFUNKEN-EH900S-tube-GOLD-PIN-MINT-/320521115105


----------



## Acapella11

Quote: 





mab1376 said:


> OK cool, Thanks!
> 
> I found this site: http://www.audiotubes.com/bjtubes.htm
> 
> ...


 
   
  Hi mab1376,
   
  Looking at
  http://www.radiomuseum.org/tubes/tube_eh900s.html
  it says that these are compared to 6BY6 "other class quality but otherwise equal". Also, the page states that E91H is a successor tube.
   
  Possibly, radiomuseum is inaccurate but when looking at the following pages of heptodes
  http://www.radiomuseum.org/tubes/tube_6cs6.html
  http://www.radiomuseum.org/tubes/tube_6by6.html
  http://www.radiomuseum.org/tubes/tube_6be6.html
  They all use the same heater current of 0.3 mA.
   
  halflife79, this is a lovely hobby space your father set up, impressive. Now you can just browse through them to find even more new families of LD compatible tubes 
   
  AFB,
  Topic: Brimar CV4012/5750/6BE6
  Quote: 





> If you like cavernous, balanced and good separation that sounds natural but still close to you (though not forward like some of the previous tubes), you'd like those.


 
  Comparing this description with my 6BE6 tubes, I can recognize "cavernous" (if that means large stage), balanced, good separation and natural. I also agree with the word "analog". Actually, analog pretty well describes the sound. With the Tung Sol, the recording quality is extremely good, to stay in the analogy. What I feel is different is that singers / players are further away than for example with the TS 6485 (6AH6 type). This goes along with the large space created.
   
  Today, I received my Pro's Kit copper wire cutter and now I am waiting for the Mullard CV417 EC91 type triodes.


----------



## mab1376

Quote: 





acapella11 said:


> Hi mab1376,
> 
> Looking at
> http://www.radiomuseum.org/tubes/tube_eh900s.html
> ...


 
   
  Thanks for the research, interesting info about those hepatodes, has anyone tried the 6CS6? Is it even compatible?
   
  and the link Gibosi posted above is for the E91H which is the successor based on your research.


----------



## Acapella11

mab1376,
  6CS6, 6BY6 and 6BE6 are all heptodes with the same pin layout, so they are all compatible. As also noted in the table on page 77, EF91/92 jumper setting is recommended, EF95 gives an altered signature.


----------



## gibosi

After spending much of the last couple weeks focused exclusively on triodes and feeling a little burned out, I decided I needed to take a break. I remembered Mordy's posting a while back about how much he enjoyed going back to his 6CB6 and this inspired me to revisit some of the first EF92-compatible pentodes we tried out. A pair of RCA 6GM6 caught my eye, and while not quite up to the very best 2-7 pentodes, I had forgotten how nice these tubes are. And after too many dry, forward triodes, it sure is nice to listen to music through "musical" tubes again.


----------



## mordy

Hi G,
   
  AH, suddenly my listening feels normal again. Did not realize how grating the triodes were on me. I just popped in a pair of Sylvania 6AH6 and they sounded good right out of the box. Well, one was a Sylvania and one was a Raytheon, but the Raytheon was in a Sylvania box, and it looked just like the other Sylvania tube.
  A closer look revealed a line printed on the Raytheon tube: "Licensed as branded on box." In other words a re-branded Sylvania tube. The date is 5747 which I think means November 1957.
   
  I wonder if some joker made up the Sylvania date code: XYZ  
	

	
	
		
		

		
			




   
  In any case, these Sylvania tubes are not too bright at all, and sound just right - musical and sweet, with all the right moves.


----------



## Audiofanboy

Hmm, I'm a bit confused after testing what looked like the cheapest tubes out of my last order... A pair of "Pinnacle" -a rebranding company that never manufactured tubes but sourced them as cheap as possible from every and any source from Mullard/Philips, German companies, miliatary overstock from anywhere, or even Russians- 6AV6/EBC91.
   
  My problem is very basic: they sound great, like really good, but I have no clue where they come from despite a full hour of research. So, I'm a little frustrated as I hate non-reproducible results -the base of all good science including the very biased "sound science".
   
  At any rate, these sounded awesome out of the box -just like the GE and TS 6485, they had that "oh, so the amp can sound like this, huh?" effect where you just know you've made a breakthrough- with realistic and natural detailed highs -on par with the TS 6485 as far as highs and naturalness go- slightly wet mids that make music musical, and -that's where they're interesting compared to the 6485- very well controlled bass that goes low and deep -and that on 38 ohms orthos, so expect some rumble on 300 ohms dynamics.
   
  10 or so hours of burn-in or so later, they do seem to be improving somewhat, but I have to say they are still quite spiky for now. Not intolerably so, but they regularly hit my "treble pain alarm" at mid to high volumes, with a bit of that "my head hurts after listening to music for an hour, why could that be? Oh wait, it's those new awesome tubes isn't it...?" effect.
   
  Anyway, it's not like anybody else can try them for now, since I _don't have a clue what they actually are_.
   
  So, here is my question: Have you seen this tube?
   

   

   
  Yeah, they look kind of cheap, don't they? Notice the side getter and getter flash, the O-getter (so not old production), the lack of any kind of extra metal structure on the top mica, the lack of mica doubling and the shape of the diode anodes (the large shiny arch like pieces of metal that cover the whole inside of the tube. That, and the -I assume- later Pinnacle brand logo (the earlier and only ones I've seen are concentric circles or a golf hole flag with Pinnacle written inside), the numbers "570" which could be a month and date or Pinnacle-specific tube type number. The fact the tube is dual labeled EBC91 shows a European market (Pinnacle was a European rebrander anyway), and the word "foreign" is usually specific to the UK market (where I bought them anyway) to differentiate foreign non-BVA production from UK-made BVA tubes -I think.
   
  The only similar-looking tubes I found on the web -deep google search and ebay- are US-made -which is poor hypothesis since they're logically European tubes- CBS-Hytron 6AV6, which admittedly look very similar, even virtually identical but would have had the "USA" label, right? I haven't found a single other European or American tubes that looked the same -same diode anode shape and side O-getter- and no Russian 6AV6 at all for that matter.
   
  http://www.ebay.com/itm/6AV6-EBC91-CBS-HYTRON-NOS-Tube-Rohre-Lampe-TSF-Valvola-Valvula-/390597071980?pt=Vintage_Electronics_R2&hash=item5af166546c
   
  http://www.ebay.com/itm/VINTAGE-CBS-6AV6-NOS-NIB-TUBE-/111077209967?pt=Vintage_Electronics_R2&hash=item19dcb7b76f
   
  Does anyone have a clue?


----------



## gibosi

Yours don't look like any of my 6AV6 - Sylvania, GE, RCA or Mullard. After looking at the CBS-Hytron on eBay, those would be my best guess.
   
  Cheers
   
  Edit: The Pax website:
   
  http://pax-comm.com/pa01007.htm
   
  According to the note at the bottom of the page, CBS-Hytron closed in 1961. The 0-getters on yours suggests late 1960s at the earliest...  so probably not CBS-Hytron after all....


----------



## Audiofanboy

And even the CBS might have some extra small structure on at the very top of the cathode, which I can't really see very well, so it is hard to be sure. A an East German or Russian origin is probably more likely, even though I can find no information about real Russian 6AV6, only from Eastern European countries or identified East brands (Tungsram, Tesla, Svetlana...) which all look different (no side getters for starters).
   
  About O-getters -at least top getters- in US tubes, I can't be sure when the change happened, but I actually have a number of tubes with the same brand, type, and maker dated '59 and '61, the former with square getters and the latter with O-getters, so I would think the change occured smack at the turn of the 50s to the 60s. So in '61, I _assume _CBS-Hytron _could _have been using O-getters.


----------



## Acapella11

Guys, If you have a heptode at hand. Make sure you try the *EF95* setting after burn in. I haven't been using this for quite a while.
   
  When I set this up today, I was quite surprised, to say the least. I really love it with my *TS 6BE6*.
   
 After a little more listening and also comparing the 6BE6 to the *TS 6485*, I think it is now quite clear to me that is _the_ setting. It is like a veil was lifted.
 On my setup, with my gear, IMHO, this is better than the TS 6485. I can hear details clearer leading to a better holographic experience, there is more air, the bass is slightly lesser punchy but does go deeper, the stage is more organized. Everything just comes together. Simply put, it sounds of better quality. That's it for me 
  
 1.) Tung Sol 6BE6, EF95 jumper
 2.) Tung Sol 6485, 2-7 strap
 3.) GE 8425 6AU6A, 2-7 strap
  
 Now you can shoot me 
  
  
  
 PS: I imagine the TS 6BE6 to work best with setups, which tend to a brighter or very neutral signature. These tubes have a natural, darker signature, which is rather, "round", very refined and true, not "hard and exciting".
  
 Updated 24/05/2013


----------



## gibosi

Quote: 





audiofanboy said:


> About O-getters -at least top getters- in US tubes, I can't be sure when the change happened, but I actually have a number of tubes with the same brand, type, and maker dated '59 and '61, the former with square getters and the latter with O-getters, so I would think the change occured smack at the turn of the 50s to the 60s. So in '61, I _assume _CBS-Hytron _could _have been using O-getters.


 
  I didn't know that O-getters appeared as early as 1961. I have a pair of 1961 TS 6AH6 with square getters and another pair, dated 1967, with halo getters, so I just assumed this change occurred during the mid to late 1960's. But it does make sense that this was likely a gradual change, perhaps occurring over a 10 year period, tube line by tube line, within each of the major manufacturers. But still, it is a little difficult to imagine CBS-Hytron making the change to halo getters around 1960 and then immediately closing.... Of course, stranger things have happened....


----------



## gibosi

Triod Summary
   
  For the past month, I have been listening almost exclusively to triodes, and now, I think it is time to summarize and then happily move on...
   
  I have four pairs of 6AV6, RCA, Sylvania, GE and Mullard; two pairs of 6J4, Sylvania 8532W and Mullard CV5311; and one pair of old-world square-getter Mullard Whyteleafe 6AQ4. I also have two newer pairs of 6AQ4 with halo getters, but didn't even bother the cut pins as these were made in the same factory at about the same time as AFB's CV4070. And after all, there is no way these could possibly be any better than his mil-spec tubes...
   
  On page 89, I compared four 6AV6 and put the Mullard on top. The Sylvania 8532W has been discussed at some length by myself and several others, and the general consensus is these are excellent tubes, but perhaps too clinical. My impressions of the Mullard equivalent, the CV5311, is that it is not significantly better than the Sylvania 8532W where it really matters. That is, it too is more clinical.
   
  This leaves the old-world 6AQ4. First and foremost, no peaky highs, no shrillness and no sibilance, and so I was encouraged to keep listening. Further, they were not too forward (no background sounds competing with the lead), with natural sounding vocals, good upper-end detail, and good bass. I liked what I heard.
   
  However, with respect to triodes, wetness and musicality have become the 64 thousand dollar questions in this forum. This tube does not seem to me to be as wet and musical as a good pentode. However, I cannot say just how dry or wet it is. I am still a beginner in the world of tubes and headphones, so I don't have a really good handle on this "wetness" thing.... 
   
  In conclusion, to my ears, the Mullard 6AV6 is still on top. Listening to these again tonight, they are more musical than the 6AQ4, with slightly forward, but natural sounding vocals. And as is typical with 6AV6, the highs are clean and detailed and the bass is solid and deep. And I am thinking, "Wow, this is what the Mullard 12AX7 sounds like!"
   
  However, now I want to try some newer Mullard/Philips 6AV6. Mine are "first-generation" tubes with D-getters. And from AFB's considerable research and experience, I have every reason to believe that "second-generation" tubes with 0-getters could very well be better.
   
  Post script: I should have my modified socket testers back soon, this week I hope, and then I will finally be able to listen to 2-7 pentodes again!!


----------



## mordy

Dear A11,
   
  I am a little bit confused. On your chart on p77 on the last line you clearly state that 6BE6, 6CS6, 6BY6 should not be used with EF95 setting without the 2-7 strap. Are you now advocating the EF95 without the strap 2-7 setting for these tubes?
   
  Completely agree with you that the 6AH6 and 6AU6 families are among the best driver tubes for the LD amps. Just finished the 20 hour burn in for my two Sylvania 6AH6 tubes mentioned above on this page. There is none of the Sylvania brightness and these tubes are excellent all around. (Actually these tubes emerge as slightly dark sounding.)
   
  Based on my experience I would say that you should try both the EF92 and the EF95/2-7 strap settings on those tubes that can be used in both modes to see which setting sounds better to you. My pair of TS 6CB6 tubes sounded much better on the EF92 setting than on the previously tried EF95/2-7 strap setting. (I was going to relegate these tubes to my pile of "tried but not true" tubes with the thought of eventually selling them, but now I am definitively keeping them.)
  LOL - this is a very civilized forum; the only shooting we do here is to shoot for the stars to get the very best listening experience....
	

	
	
		
		

		
		
	


	



   
   
  Cheers


----------



## gibosi

Mordy,
   
  It seems as if there is an unspoken rule in strapping pentodes (and heptodes) that one and only one grid can be tied to the cathode. However, it is perfectly acceptable to tie more than one grid to the anode. This heptode is similar to the 6AK5 in that one of the grids has already been tied to the cathode internally. And therefore, if you were to tie pins 2 and 7 together, this would tie two grids to the cathode, breaking this rule. As A11 noted (post #1092, page 80) when the 2-7 strapping was used with this heptode, breaking this rule, the sound was rather off. Therefore, if you choose not to use the EF92 setting which properly accounts for all the extra grids, it is better to just let the grid on pin 7 hang there, than to connect it to the cathode. Perhaps others can explain this better than I, but this seems to make sense to me....


----------



## Acapella11

Quote: 





mordy said:


> Dear A11,
> 
> I am a little bit confused. On your chart on p77 on the last line you clearly state that 6BE6, 6CS6, 6BY6 should not be used with EF95 setting without the 2-7 strap. Are you now advocating the EF95 without the strap 2-7 setting for these tubes?
> 
> ...


 
   
  Hi Mordy,
  yes, EF95 and no 2/7 strap. Theoretically, a hanging grid seems not the best case scenario. However, for some tubes families people worry, for others they don't and there is no (negative) experience in running heptodes with the EF95 setting. The sound is just best at that setting for my ears and I wouldn't want to sacrifice it due to the technically sub-optimal connection.


----------



## inphu510n

I've got a crazy idea.
I saw these the other day and I'm really intrigued. I have yet to see other Tung Sol 8425 tubes and while they aren't Tektronix tubes, they've got to be pretty interesting.
  There are 30 of them and the total cost is going to be at least $82 shipped. That works out to about $2.73 USD each.
  What if we pooled money into one PayPal account, bought the tubes, had the tubes delivered to one person and then that person would mail out the tubes to whomever had bought them.
  Risky indeed but I know myself to have great integrity.
   
  I suppose it also creates the question about other, similar tube purchases where there are packs this size and larger available and more than one person is interested in them yet does not need 20+ tubes to themselves. With the rates we're chewing on tubes around here, sleeves of 5 are perfect for me.
   
  Just a thought. We've all been praised for the civility and thoughtfulness of this thread and it goes to show who it is that is currently making this thread stay alive are people of some integrity and kindness.


----------



## hypnos1

Quote: 





mordy said:


> Before changing the jumpers back from the the EF92 setting to the EF95 setting I decided to try two tubes that are just plug and play with this setting that I just got from a friend: Sylvania 6BE6 and Sylvania 6DK6.
> 
> These are quite nice right out of the box with the 6DK6 being brighter and louder. At least they are both Sylvanias....
> 
> I could go on with the galaxy swallowing sound stage, the shimmering endless decay highs, the book shelf rattling bass blah blah, but I think it is more prudent to wait for them to burn in...


 
  Hi mordy.
   
  Am wondering what your final impression was of the 6DK6s - your eloquent description above seems to apply also to the RCAs (used) I have just popped in. To my ears (and with my equipment, of course) they seem almost like the magical TS 6485s but with more bass...or am I deluding myself?
   
  Anyone else tried these tubes? Would love your comments also if you have...


----------



## gibosi

Quote: 





hypnos1 said:


> Am wondering what your final impression was of the 6DK6s - your eloquent description above seems to apply also to the RCAs (used) I have just popped in. To my ears (and with my equipment, of course) they seem almost like the magical TS 6485s but with more bass...or am I deluding myself?
> 
> Anyone else tried these tubes? Would love your comments also if you have...


 
   
  A number of us tried the GE 8136, which is a special version of 6DK6. You will find some impressions starting on page 55 post 815. I suggest you search for "8136" in this forum.


----------



## mordy

When I first wrote about the Sylvania  6DK6 tube I did it more tongue-in-cheek as a joke and used a very exaggerated language trying to be humorous.
   
  Now I realize that the people on this forum are very serious people who are truly searching for the truest listening experience so I realize that I have to be careful in expressing myself very clearly. Even though I wrote blah blah after the description and added a grinning emoticon I realize that some may take me seriously about a tube that I wrote about before even giving it time to burn in.
   
  In another post I explained that I now believe that I cannot truly evaluate tubes in the best way by listening to two different ones at the same time (unless they are very similar in their sound signature).
   
  I only have one Sylvania 6DK6 tube. I am now listening to it critically together with a 6AG5 Sylvania tube. They sound very similar. For the 6AG5 I am using the E95 setting, and for the 6DK6 the E95 2-7 setting. (The splendid MKIII can take it!)
   
  Both are fine tubes with a very pleasant and  natural presentation without any obvious faults. However, they lack that "wow" factor and don't induce that toe tapping stage where you forget about the tubes and just listen to the music.
  These two tubes are very good but a step or two below the best 6AH6 and 6AU6 tubes.
   
  Hypnos 1,
   
  If you find a set of tubes that you are really happy with those are the right ones for you. Tubes react differently to different equipment and people have different tastes in music. What we are trying to do is to find a selection of excellent tubes, and then people have to find out what is best for them. In addition, there may be one brand of the same tube that sounds better to you than another brand of the same tube. (Tung Sol vs Sylvania vs RCA vs Mullard etc.)
   
  Even though there are many variables, it appears that it is possible to get a consensus on which ones are the best choices.
   
  What you hear is what you hear. Nobody can take that away from you, and you are not deluding yourself. Sometimes it takes time to come to a true conclusion about what you really like. The initial impression may fade away, and you may realize that something bothers you and switch to something else.
   
  Happy tube rolling!


----------



## MIKELAP

Quote: 





mordy said:


> When I first wrote about the Sylvania  6DK6 tube I did it more tongue-in-cheek as a joke and used a very exaggerated language trying to be humorous.
> 
> Now I realize that the people on this forum are very serious people who are truly searching for the truest listening experience so I realize that I have to be careful in expressing myself very clearly. Even though I wrote blah blah after the description and added a grinning emoticon I realize that some may take me seriously about a tube that I wrote about before even giving it time to burn in.
> 
> ...


 
  mordy dont change a thing humour is good


----------



## Acapella11

Quote: 





> Originally Posted by *mordy* /img/forum/go_quote.gif
> 
> Hypnos 1,
> 
> ...


 
   
  Very well put Mordy. +1
   
  It is probably like your re-discovery of the 6CB6 tubes using the EF91/91 jumper setting. I was so glad I tried the EF95 setting for the TS 6BE6 again. Actually, I realized I found something important to me. Also, I noticed the tubes glowed stronger using the  EF91/92 setting than with the EF95 and I had a slight hum on one tube on EF91/92, which disappeared with EF95.
   
  Humor is great and also makes reading more fun! If it is the description of a tube, only make sure people understand its an exaggeration. 
   
  OT: Mikelap, you got the HD800. Congrats! How do you like them and did you dare yet to plug them into the LD?


----------



## mordy

Thanks for the encouraging words. I am slowly recovering from Trioditis and Audiophilia Confucia, but finally found the right antidote: Tektronix Westinghouse 6AU6A/4825A.
   
  Clarity, texture, timbre, liveliness, microdynamics en masse, involuntary toe tapping. C L A R I TY
   
  Feeling good


----------



## MIKELAP

Quote: 





acapella11 said:


> Very well put Mordy. +1
> 
> It is probably like your re-discovery of the 6CB6 tubes using the EF91/91 jumper setting. I was so glad I tried the EF95 setting for the TS 6BE6 again. Actually, I realized I found something important to me. Also, I noticed the tubes glowed stronger using the  EF91/92 setting than with the EF95 and I had a slight hum on one tube on EF91/92, which disappeared with EF95.
> 
> ...


 
  Thanks Acapella11. Postman delivered  them this morning but of course i was out when he delivered them so ill have to wait until tomorrow to go pick them up at post office.Cant wait to try them with both my amps actually. because from what i heard the Senns love tube amps going to be busy tomorrow good because they are calling for rain all weekend anyways so no motorcycle this weekend.


----------



## hypnos1

Hi mordy.
   
  Many thanks for your considered reply - have now got a handle on the wonderful humour that is shared on this great thread...please, PLEASE do not change! It is something that adds a welcome and precious ingredient to the vast knowledge, experience and enterprise shown by an invaluable bunch of guys. Stay as you are, I implore you.
   
  Re the 6DK6s methinks I may have been seduced by the bass response first of all, and then made the basic mistake of not trying different genres of music. Time also must play its role, yes...
  Will enjoy seeing how things develop - all part of the rolling game, n'est-ce pas? I do appreciate your wise words, mordy...
   
  Gibosi.
   
  Thanks for the info on the 8136s.


----------



## zedmeco

give your headphones a work out!
   
  https://soundcloud.com/zedmeco/sets/noiz-noir-testa
   
  still a work in progress but an album full of testing frequencies for your delectation.
  z


----------



## MIKELAP

Quote: 





zedmeco said:


> give your headphones a work out!
> 
> https://soundcloud.com/zedmeco/sets/noiz-noir-testa
> 
> ...


 
  i posted a while back and said that i recongnized your icon from somewhere and finally it was your stuff i listened to on soudcloud .I love electronic music I am a big fan of kraftwerk, Jean-Michel Jarre, Tangerine dream ects.Good work love your stuff and your sounds.


----------



## MIKELAP

What is the bitrate your tunes are recorded at .My Denons love that bass.


----------



## zedmeco

thanks Mike, I grew up on the same recipe of electronic music. these are 320 aac files (m4p)
  these tracks were mixed monitoring on my ld and sen hd650, using the voskhods 6zh1p-ev and novosibirsk 6h6p i gold grids/pins!
  really happy you like them.


----------



## gibosi

Once in a while I stumble across "6AH6V" tubes and I have been wondering how these differ from standard 6AH6. Casually searching on Google hasn't turned anything up... Does anyone know exactly what a 6AH6 with a "V" is?


----------



## mab1376

Quote: 





zedmeco said:


> thanks Mike, I grew up on the same recipe of electronic music. these are 320 aac files (m4p)
> these tracks were mixed monitoring on my ld and sen hd650, using the voskhods 6zh1p-ev and novosibirsk 6h6p i gold grids/pins!
> really happy you like them.


 
   
  The Tung-sol 6AK5W from the 50's I've found to have a great low end for electronic music.
   
  Sounds great with VNV nation, Infected Mushroom, KMFDM, really like the new Daft Punk album with those too!
   





   
  Generally with this kind of music I would use my JDS C421 and my Ultrasone Pro900's with my iBasso D6 as the DAC.


----------



## BGRoberts

Got a question.
   
  How do you all keep track of all these tubes?
  I mean, is it all in your memory?  Do you keep a tube journal/diary?  3 X 5 cards?  Spreadsheets?  Database?
  Is there an app for that?


----------



## mab1376

Quote: 





bgroberts said:


> Got a question.
> 
> How do you all keep track of all these tubes?
> I mean, is it all in your memory?  Do you keep a tube journal/diary?  3 X 5 cards?  Spreadsheets?  Database?
> Is there an app for that?


 
  Page 77 has a chart that's been continuously updated: http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/1140


----------



## BGRoberts

Thanks for the link to the list.
   
  I guess I was thinking more of keeping track of my personal tube collection, notes, etc.
   
  Right now I have handwritten notes on 3x5 cards.  Thinking of getting those on the computer/tablet/phone somehow.


----------



## mordy

HI BG,
   
  Don't know how many tubes you want to keep track of. Personally I probably have around 300 tubes. As the excellent work of the people on this forum progresses I am buying new tubes that show great promise in sound reproduction.
  Therefore I end up with a large amount of tubes that I don't listen to any more. Many of these I bought without boxes. I found an inexpensive way of storing them in plastic boxes made for nuts, screws or small parts etc.. Some of these boxes have movable dividers. I took along a couple of tubes to the hardware store and picked a box that accommodated the sizes I needed to store.
  For around $6-7 I got a box with 48 compartments. Then I sorted the tubes and put them into the compartments with a sticker on the lid corresponding to the contents underneath the sticker. Here I write brand, dates etc. One box can store around 120 tubes without boxes, and I can vary the sizes of the compartments by moving the dividers if I have 4 or 10 of the same type of tube. (If a compartment is not full, I stick in pieces of foam "peanuts" to keep the tubes in place.)
  It may be hard to grab a tube to get out of the box. On the suggestion of Mikeleap (?) I bought rubber fingers in an office supply store (size XL is the right size) that makes it easy to grip the tubes.
  The new tubes I am buying now usually come with boxes. I just store them in a shoe box with rubber bands keeping the same type together. Ultimately, I end up with a few favorite tubes that get their own special box.
  If you have much larger quantities in tube boxes I could imagine a shelving system of some kind.
  I have to admit that I keep most of the currently used tubes committed to memory. Stick the hand into the shoe box, under the the pieces of bubble wrap, left corner top, in unmarked boxes - yep; there are the Tektronix 6AU6 that I want to try. I'm afraid that if I get too organized I would not be able to find them.....LOL
  Don't know if this is helpful....Good luck!


----------



## gibosi

Quote: 





gibosi said:


> Once in a while I stumble across "6AH6V" tubes and I have been wondering how these differ from standard 6AH6. Casually searching on Google hasn't turned anything up... Does anyone know exactly what a 6AH6 with a "V" is?


 
   
  So far, the only 6AH6V tubes I have found are Raytheon. But again, I haven't been able to discover what the "V" was supposed to indicate.
   
  Also, it appears that RCA also made 6485/6AH6 tubes. Has anyone tried them?


----------



## MIKELAP

i found a few pictures related to t.v. and on that Motorola tv they used 6a6h tube or 6cb6 tubes and they where using these tubes for the video amplier so could the v stand for video a guess. here is the picture. What do you think


----------



## redrum42

Hi guys,
   
  I have a mk iv driving HD600s. I love the sound of the HD600s on all frequencies apart from the very top end. I find the ultra-highs to be a bit intrusive and harsh, making hi-hats and certain cymbal blasts too piercing and prominent. Any tube recommendations to take the edge off these ultra-highs without sacrificing the rest of the treble? I don't want to make the HD600s any more laid back in the upper mids, lower treble because I think they sound perfect throughout the rest of the spectrum. Sweet and warm mid would be nice too...
   
  Cheers.

 Andrew


----------



## Acapella11

redrum, Which tubes are using at the moment?


----------



## redrum42

Quote: 





acapella11 said:


> redrum, Which tubes are using at the moment?


 
  I have what I think are the stock tubes that came with the amp (bought this second hand), and a pair of rca black plate 5654s that came with it. I cant hear much difference between these two when it comes to the ultra-highs. Keep changing my mind on which is harsher.


----------



## mordy

Hi redrum42,
   
  I have found that many tubes from different brands exhibit too much treble. I have the luxury of having tone controls in my system, so I can turn down the treble and making it much more pleasant.
  In the absence of tone controls, I did find that changing the original power tubes which were 6N6P-i to 6N6P tubes (available cheap) or even better to 6N6P  gold grid tubes "tamed" some of the excessive treble.


----------



## mordy

Mikeleap,
   
  Here is a comment I found on the Internet that seems to explain the letter V on a schematic:
   
  "More elaborately, on a schematic, you have to have a way to designate the individual components. Resistors are R, Caps are C, transistors are Q, Tubes are V, etc. each of the 50 resistors is designated R1, R2, R3, etc. So from a technical point of view, it means that this tube is marked V1 on the schematic.

 Since tube amp schematics tend to flow left to right, input to output, tubes in particular positions tends to be called by particular V numbers - i.e. the first preamp tube tends to be called V1 because it is normally first on the schematic.

 However, it is also common parlance with particular known amp topologies to say V-whatever, and everyone knows it's the phase inverter or whatever (sort of losing the schematic tie-in). _Ultimately, it's just a schematic term_."
   
  In this context a tube is called V because of the British name for tube which is Valve.
   
  However, it does not explain the letter V printed on the tube itself.
   
  Usually, a tube gets a designation such as 6AH6 as an example. Further developments of the tube get called 6AH6A, 6AH6B and 6AH6C and so on. The changes could be a small change in the specifications of a tube, such as modifications for the time it takes for the heater to come to full output to suit certain applications.
   
  Still does not explain the V designation though....


----------



## mordy

Hi G,
   
  In addition to the Raytheon 6AH6V tubes I was able to find 6A6V tubes from Tung Sol, CBC, TUBE and Capeheart through a simple Google search.
   
   
  Found this seller who has 6AH6 tubes from $0.60 to $3.50 (shipping not specified). Does anybody have experience with John Kendall's Vintage Electronic Services?
   
  http://www.king-cart.com/vintageelectronics/product=tubes/keywords=/exact_match=exact/next=390/return_page=


----------



## BGRoberts

Thank you for that detailed and informative reply.
  I'll have to look at the hardware store for some boxes like you mentioned.
  I'm really looking for some kind of "list: software to keep track of my tube collection.  I've bought duplicates of several tubes, just because I forgot I already had them
  It would be nice to have something tracking things just so I could at a glance tell what I have, what I might be interested in, etc.
  I'm a computer geek, and a list-a-holic,

  Again, many thanks for your info-packedreply!


----------



## mordy

You may find that the duplicate tubes sound different from each other.....Different production runs and years and different internal construction may make a difference in how they sound.


----------



## redrum42

[duplicate post]


----------



## redrum42

Quote: 





mordy said:


> Hi redrum42,
> 
> I have found that many tubes from different brands exhibit too much treble. I have the luxury of having tone controls in my system, so I can turn down the treble and making it much more pleasant.
> In the absence of tone controls, I did find that changing the original power tubes which were 6N6P-i to 6N6P tubes (available cheap) or even better to 6N6P  gold grid tubes "tamed" some of the excessive treble.


 
Thanks for your suggestion. I'll get some of them. Any signal tube recommendations that would have softer treble than the rca black plates I am currently using? Thanks.


----------



## gibosi

Quote: 





mordy said:


> Hi G,
> 
> In addition to the Raytheon 6AH6V tubes I was able to find 6A6V tubes from Tung Sol, CBC, TUBE and Capeheart through a simple Google search.
> 
> ...


 
   
  It is interesting that the most expensive 6AH6 this vendor carries is the 6AH6V. One could infer that the "V" implies something better than a standard 6AH6, but we have no data to support that inference. And I have no experience with this particular vendor.....
   
  This eBay vendor, AudioPathic Distractions, has pictures of the Raytheon 6AH6 and 6AH6V. 
   
  http://www.ebay.com/itm/390452122072?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649
   
  The one with 6AH6 etched into the glass, second from the left, looks very similar to the TS 6AH6. The right-most tube, which I assume is a 6AH6V, looks somewhat different.....


----------



## gibosi

Quote: 





redrum42 said:


> Thanks for your suggestion. I'll get some of them. Any signal tube recommendations that would have softer treble than the rca black plates I am currently using? Thanks.


 
   
  It is very hard to say... Everyone's ears are different....
   
  In the end, I think you will just have to try a more few tubes and decide for yourself. At a minimum, I would encourage you to try something other than another 5654. While I do not have personal experience with HD6X0 headphones, I have read that the Mullard M8161 (CV4015), an EF92 tube, sounds very good with them (See page 1 for a little more info.)


----------



## MIKELAP

Quote: 





bgroberts said:


> Thank you for that detailed and informative reply.
> I'll have to look at the hardware store for some boxes like you mentioned.
> I'm really looking for some kind of "list: software to keep track of my tube collection.  I've bought duplicates of several tubes, just because I forgot I already had them
> It would be nice to have something tracking things just so I could at a glance tell what I have, what I might be interested in, etc.
> ...


 
  Hey BG what i do to remember i take pictures of the tubes i buy i open a folder on the computer stick the pictures in the folder along with all the infos related to the tubes thats it instant archive .


----------



## BGRoberts

mikelap said:


> Hey BG what i do to remember i take pictures of the tubes i buy i open a folder on the computer stick the pictures in the folder along with all the infos related to the tubes thats it instant archive .




GOOD idea!
I like it.


----------



## mordy

Great idea! Better than the shoe box, but wait, where do I store the physical tubes in the PC? LOL
   
  I thought I only had one 6AG5, but now I found another five RCA 6AG5 tubes in the bottom of a box of spares of TS 6AJ5 that used to be my favorite tube before I got acquainted with the great tubes on this forum.
   
  I guess that you could put in the location of the tubes in the computer file. Maybe the file could be organized like this:
   
  Picture
  Brand Name: Unobtanium
  Family: 6XYZ6/1234
  Production Date: Can't decipher, but probably 1960's
  Best setting: EF92 (or was it EF95 2-7 strap?)
  Buy Date: 13/03/2020
  Price paid: Embarrassed to tell
  Tube location: Bottom of bigger box on top of the Win XP PC next to printer and sub woofer. Tube box not original but in Standard Electronics red/white box with shaky hand writing of seller from AK
  Flavor: Subtle hints of tannins, blueberry, vanilla and a peat moss with a lingering burning finish            (tube runs HOT)
   
  Where were I - never mind!


----------



## inphu510n

Hahahaha I love it Mordy!
  The extra peat I've found really adds a shimmer to the highs that isn't sibilant and yet still manages to add more micro detail to the vocals.
   
  I received the 6AU6 to 6AK5 adapters from the eBay seller "happydiy998" this afternoon and immediately switched my jumpers and plugged in some 8425's.
  I am NOT happy. All I got through my headphones was a mid level buzzing sound and if I cranked the volume to 90 I could faintly hear the music. I switched through several tubes, made sure things were seated correctly and still had the same effect with all of them.
  I then checked the amp with a pair of Sylvania 6AU6WC's where I soldered pins 2+7 together and it works fine.
  Now I'm very curious to see what reports come back from the others who have ordered these adapters.
   
  I believe my MKII simply doesn't like triode tubes. The light buzzing I was experiencing in the right channel is not present with tubes on the 6AK5 setting and the few other EF91/92 compatible tubes I have were fine with their jumpers set.
  This is pretty much fine with me because as has been noted, they had a tendency to compress the instruments together and had a general thinness to them that was unfavorable. Not a bad tube by any means but going back to the 6AU6 series tubes is more fun.


----------



## Acapella11

Quote: 





redrum42 said:


> I have what I think are the stock tubes that came with the amp (bought this second hand), and a pair of rca black plate 5654s that came with it. I cant hear much difference between these two when it comes to the ultra-highs. Keep changing my mind on which is harsher.


 
 
 Hi redrum42, I imagine your driver tubes are already on the "tubier" side and agree with Mordy that the 6H30P tubes can be the culprit. They sound hard, "glassy" if you wish. This describes them well also in a different way, as they are also quite revealing, more than the 6N6P tubes to my ears. Generally, the 6H30P-tubes are considered higher spec than the 6N6P-tubes. It really comes down to system matching in the end, even cables play their role. For 6N6P-tubes, older tubes are considered better than newer ones.
 The end of the Cold War is often used as guide line to the last years yielding good Russian tubes. It ended 1991. However, the most important marker relevant for Soviet tube production seems to be the point when 1985 Mikhail Gorbachev became General Secretary of the Communist Party of the Soviet Union. He has not only liberalized the Soviet Union - 1985 glasnost ("openness"), 1987 perestroika ("re-organization") but also the tube production. This removed the strict government control of tube production. I would suggest to aim for a 1984 and to be safe maybe a 1983 or older tube.*
 My favourite power tube is the 6N6P-IR but I haven't use the 6H30P-DR yet. R indicates a special low noise quality also seen in the pinnacle tube 6H30P-DR (where the cyrilllic H is also often written as the transliterated N). 6N6P-I and 6N6P-IR have only 500 hours guaranteed working hours due to high cathode current used, which could equal to a year of operation. But they may of course also work longer than that. My 6N6P-IR was produced 1974 and does not sound "glassy" as the 6H30P tubes do but a bit warmer, has deeper bass, larger stage and the treble is well extended but not harsh. The stage is the largest between all tubes I tried.
  
 Now, the choice is yours. Enjoy the tube rolling.
  
  
 *see also: http://www.diyaudio.com/forums/tubes-valves/138426-6n6p-vs-6n6p-i-2.html, post 19


----------



## MIKELAP

Hey guys i just received the sockets i put in the 6136 tubes i got the ef95 setting right  it doesnt work it is the ef 95 setting got any ideas


----------



## MIKELAP

Also received my other tubes 6ah6wa tried those doent work so maybe they got thing backwards the 6ak5 tubes on top and 6au6 on bottom of socket who knows and god knows i was diligent in explaining in detail to them what was needed for those sockets i will send them an email later today but right now im gone fishing .because im kind of p...... right now. but if you have any ideas or i did something wrong setting wise let me know thanks guys.


----------



## Acapella11

Quote: 





mikelap said:


> Hey guys i just received the sockets i put in the 6136 tubes i got the ef95 setting right  it doesnt work it is the ef 95 setting got any ideas


 

 Hi Mikelap,
  I was at one point not sure whether I set the jumpers correctly to EF95 or not . So, as a reminder for everyone including myself, I drew up a schematic highlighting the setting. You could keep this as reference, might came handy at times.


----------



## hypnos1

Quote: 





acapella11 said:


> Guys, If you have a heptode at hand. Make sure you try the *EF95* setting after burn in. I haven't been using this for quite a while.
> 
> When I set this up today, I was quite surprised, to say the least. I really love it with my *TS 6BE6*.
> 
> ... 
  Hi A11.
   
  Have been burning-in some Sylvania Gold  Brand  5750s on EF95 (minus 2,7) with 9 hour stretches and no problems...they sound amazing. Hope everyone gives this a try...Well discovered!!


----------



## mab1376

Quote: 





hypnos1 said:


> Hi A11.
> 
> Have been burning-in some Sylvania Gold  Brand  5750s on EF95 (minus 2,7) with 9 hour stretches and no problems...they sound amazing. Hope everyone gives this a try...Well discovered!!


 
   
  So for the 6BE6/5750, use EF95 setting with no 2-7 strap for optimal performance?


----------



## hypnos1

Quote: 





mab1376 said:


> So for the 6BE6/5750, use EF95 setting with no 2-7 strap for optimal performance?


 
  Hi mab.
   
  Yep! Acapella 11 (see page 90) found there was no need for the strap, and that the sound IMPROVED - two for the price of one,even! And as I mentioned, I've experienced no problems so far - even after long burn-in sessions. What more could you ask for? These guys really are the business...


----------



## Acapella11

Quote: 





mab1376 said:


> So for the 6BE6/5750, use EF95 setting with no 2-7 strap for optimal performance?


 

 Yes.
   
  1) EF95: Most balanced setting. Very nice bass, good treble extension. (Leaves grid 3 floating, no issues on my system. Fixed one of the two tubes humming.)
  2) EF91/92: Most "analog" setting. Brighter than the above, less bass weight
  3) EF95 + 2/7 strap: Very bass heavy and rolled off treble, sounds somewhat dynamic compressed to me.


----------



## mab1376

Awesome!, Thanks for the info.
   
  As of this moment I FINALLY did the pin 2-7 strap for the Tung Sol 6AH6WA with USAF markings on it.
   
  So far my impressions are WOW, from the Raytheon 6GX6 tubes I was using.
   
  I'll report back later once they're burned in, also waiting on TS 6BE6 tubes and have some untested GE 6AU6WA tubes on hand as well.


----------



## MIKELAP

Quote: 





mab1376 said:


> Awesome!, Thanks for the info.
> 
> As of this moment I FINALLY did the pin 2-7 strap for the Tung Sol 6AH6WA with USAF markings on it.
> 
> ...


 
   
  Actually i am listening to those also same seller i guess USAF TS 6AH6WA  got those this morning sound pretty good i listened before to the 6AU6A  they sound equally as good .


----------



## mordy

I have the Tung Sol JTL 6AH6WA tubes from 1962/63 which are very good. Did anybody have a chance to compare these to the Tung Sol 6485?
  Is there any difference?


----------



## mab1376

Quote: 





mikelap said:


> Actually i am listening to those also same seller i guess USAF TS 6AH6WA  got those this morning sound pretty good i listened before to the 6AU6A  they sound equally as good .


 
   
  Which power tubes are you running? currently I'm using the 6N6P-IR, i also plan on testing with the EH 6H30P-PI. Also I'm on an MK IV SE if that makes much of a difference. I honestly never compared it to the III, it was in my budget so I splurged on the higher tier model.


----------



## hypnos1

mab 1376.
   
  If you can stretch your budget even further (or beg/steal/borrow!), go for the 6H(N)30P-DRs - it appears all owners of these could never go back...me included. It just hurts a bit to think they were listed less than 10 years ago at 18$ !! - would have been a marvellous investment...
   
  IF you do, beware the later ones (eg. '91), at a lower than average cost - they are not much different to the (much cheaper) 6H30Pis. They look darned near identical - the (better) earlier ones (eg early 80s) have an inner coating that extends a good bit further down the tube, and has a slight bronze tint . Certainly worth the extra...
   
   
  All.
   
  Another 10 hours on the Sylvania GB 5750s(6BE6) - about 35 in all - on the EF95 setting (easy for me as this MKiv se is hardwired just for same) and the bass is now doing what A11 described, along with everything else. MAGICAL. Thanks A11...


----------



## mab1376

Quote: 





hypnos1 said:


> mab 1376.
> 
> If you can stretch your budget even further (or beg/steal/borrow!), go for the 6H(N)30P-DRs - it appears all owners of these could never go back...me included. It just hurts a bit to think they were listed less than 10 years ago at 18$ !! - would have been a marvellous investment...
> 
> ...


 
   
  I've had these in my sights since I bought the amp, hopefully one day soon!
   
  http://www.ebay.com/itm/6N30P-DR-Matched-Pair-Reflector-Supertube-NOS-Lot-of-2-tubes-1982-/281113624022?pt=Vintage_Electronics_R2&hash=item4173ad7dd6


----------



## MIKELAP

Quote: 





mab1376 said:


> Which power tubes are you running? currently I'm using the 6N6P-IR, i also plan on testing with the EH 6H30P-PI. Also I'm on an MK IV SE if that makes much of a difference. I honestly never compared it to the III, it was in my budget so I splurged on the higher tier model.


 
  I am using 6H30PI gold pin power tubes i have revision 2.0 mk3


----------



## MIKELAP

Regarding the sockets it seems they did not send me the right ones they sent the B models and we need the A model there picture


----------



## mab1376

I got the same email, for now i got my 2-7 strap working and I'm not touching it until i get the right adapter.


----------



## MIKELAP

Quote: 





mab1376 said:


> I got the same email, for now i got my 2-7 strap working and I'm not touching it until i get the right adapter.


 
  Same here meanwhile those 6ah6wa are pretty nice really detailed how about you similar .


----------



## BGRoberts

Quote: 





mikelap said:


> Regarding the sockets it seems they did not send me the right ones they sent the B models and we need the A model there picture


 
   
  Did they send everyone the wrong one's?
  Interesting.
  I've requested they send me the A type.


----------



## MIKELAP

Quote: 





bgroberts said:


> Did they send everyone the wrong one's?
> Interesting.
> I've requested they send me the A type.


 
  Me to ,if B doesnt work only choice left is A that the extent of my knowledge but if A doesnt work maybe  a more technical approach in the phrasing department from the more knowledgeable guys on this forum would help them understand what we mean by strapping 2 and 7. we will see in a couple of weeks when we get the other sockets.


----------



## inphu510n

When they asked the A vs B question I replied by sending them the image AFB took of the 2-7 pin jumper in post #876.
  Somehow, I think they misunderstood what we were asking for because the A and B diagrams they sent do not make sense to me. It's as if they thought we wanted to tie pins 2/7 together and have them routed into either pin 7's socket or pin 2's socket.


----------



## Acapella11

Quote: 





mab1376 said:


> Which power tubes are you running? currently I'm using the 6N6P-IR, i also plan on testing with the EH 6H30P-PI. Also I'm on an MK IV SE if that makes much of a difference. I honestly never compared it to the III, it was in my budget so I splurged on the higher tier model.


 

 Hi mab1376, I use the 6N6P-IR as well and have also a Sovtek 6H30P-EV. The latter was only from 2011, so may not reflect a pre-1985 6H30P-EV but comparing those, I assume that only the 6H30P-DR would be a sensible upgrade from 6N6P-IR.


----------



## zedmeco

damm them, I got the same email! another month to wait.
  at least my sylvania gold brand 5654 arrived a couple of days ago.
  these are just amazing tubes. since i first found this site, it was penchum's review
  that got me interested in the ldmk3 and his verdict on these tubes was
  spot on, but it took another year to find them and i ended up paying over $100 
  once the import duty was paid, but they are worth it! roll on the new plugs


----------



## mab1376

Quote: 





mikelap said:


> Same here meanwhile those 6ah6wa are pretty nice really detailed how about you similar .


 
   
  Very well rounded feels like nothing is missing; i.e. very detailed. Nice bass kick, and pretty transparent.
   
  Kinda makes me think that its like the Tung Sol 6AK5W merged with the M8161.
   
  Ran though the new Queens of the Stone Age album "...Like Clockwork" this morning since I finally acquired a FLAC version; absolutely sublime!


----------



## MIKELAP

Quote: 





inphu510n said:


> When they asked the A vs B question I replied by sending them the image AFB took of the 2-7 pin jumper in post #876.
> Somehow, I think they misunderstood what we were asking for because the A and B diagrams they sent do not make sense to me. It's as if they thought we wanted to tie pins 2/7 together and have them routed into either pin 7's socket or pin 2's socket.


 
  I sent them that picture also because that the extent of my knowledge i guess they didnt understand ,could you put in a sentence what would be needed to do to those sockets for them to work with the 6au6 and 6ah6 tubes if the new sockets they send us dont work ,or that about what you know on the subject to.


----------



## mab1376

Quote: 





acapella11 said:


> Hi mab1376, I use the 6N6P-IR as well and have also a Sovtek 6H30P-EV. The latter was only from 2011, so may not reflect a pre-1985 6H30P-EV but comparing those, I assume that only the 6H30P-DR would be a sensible upgrade from 6N6P-IR.


 
   
  would this be a worth while upgrade from the 6N6P-IR? http://www.ebay.com/itm/NEW-SOVTEK-6H30PI-Supertube-ARC-Conrad-Johnson-BAT-2PCS-/120748685916?pt=Vintage_Electronics_R2&hash=item1c1d2eba5c
   
  or even these: http://www.ebay.com/itm/MATCHED-PAIR-6N30P-DR-6H30-Pi-SUPER-TUBES-UNUSED-TESTED-/161031708331?pt=Vintage_Electronics_R2&hash=item257e3cdeab
   
  They're from '88, not sure why they're so much cheaper than the earlier 80's matched pairs that go for $250.
   
  also, might pickup a pair of these to try out as well: http://www.ebay.com/itm/Telefunken-TFK-EK90-6H31-6BE6-NOS-Radio-vacuum-tubes-/230700108102?pt=Vintage_Electronics_R2&hash=item35b6cc4946


----------



## zedmeco

mikelap said:


> I sent them that picture also because that the extent of my knowledge i guess they didnt understand ,could you put in a sentence what would be needed to do to those sockets for them to work with the 6au6 and 6ah6 tubes if the new sockets they send us dont work ,or that about what you know on the subject to.


I have taken it apart, they seem to have connected 2to7 but disconnected pin 2 so there is nothing going from the amp to the tube along pin 2 I will try to upload a pic I have taken. Any ideas, maybe you should tell them the pin needs to be connected to the p


----------



## Audiofanboy

Is the bottom of that adapter a "deconstructed" tube base? It sure looks like one, and it's giving me an idea. It probably wouldn't be that hard to make on of these adapters with cheap sockets bought on ebay, a soldering iron and a "tube base" transplant from a tube that's been in a terrible accident and may never amplify music again...
   
  But that's not why I'm posting... Has anyone tried some Tung-Sol 6AV6 tubes? It seems to be like the only US brand of 6AV6 that hasn't been talked about around here and I'm kind of curious about them, since I can't remember a Tung-Sol tube I've been disappointed with.


----------



## gibosi

It appears that they need to combine A model and the B model into a third model. The A model leaves pin 7 disconnected. The B model leaves pin 2 disconnected. What is needed is an adapter with every pin connected. Again, they need to combine models A and B into a third model, with pin 2 connected to pin 7 and pin 7 connected to pin 2.


----------



## gibosi

Quote: 





audiofanboy said:


> But that's not why I'm posting... Has anyone tried some Tung-Sol 6AV6 tubes? It seems to be like the only US brand of 6AV6 that hasn't been talked about around here and I'm kind of curious about them, since I can't remember a Tung-Sol tube I've been disappointed with.


 
   
  Mordy tried a Tun-Sol 6AV6, post 1278, page 86. He was not favorably impressed......


----------



## zedmeco

gibosi said:


> It appears that they need to combine A model and the B model into a third model. The A model leaves pin 7 disconnected. The B model leaves pin 2 disconnected. What is needed is an adapter with every pin connected. Again, they need to combine models A and B into a third model, with pin 2 connected to pin 7 and pin 7 connected to pin 2.


I sent them a email telling them just that and sent them a copy of the post that has the list and a photo of the wire mod inplace. It is a glass tube bottom with the pins in place and a socket connected above. Methinks it's solder time!


----------



## Audiofanboy

Quote: 





gibosi said:


> Mordy tried a Tun-Sol 6AV6, post 1278, page 86. He was not favorably impressed......


 
  OK, I finally found the Mordy's post where he tested them, and the pictures a few pages before that.
   
  Mordy, could you tell me what kind of getter this tube had? I can't quite see on the picture...


----------



## mordy

Hi AFB,
   
  The TS 6AV6 tube that I have has a circular getter.
   
  Could be my equipment, personal taste or ears, but I have not been able to muster any enthusiasm for the 6J4 triode and the diode/triode 6AQ6/6AT6 and 6AV6 families.
   
  In terms of treble detail they are probably better than anything else I tried, but the rest of the presentation is unnatural to me, as described in previous posts. The emphasis on bringing background instruments to the front I found especially grating in the long run. In other words, these tubes are extremely detailed in the highs, but not musical to me.
   
  I have seven different tubes of this kind, all modded: Five 6AV6, one 6J4 and one 8532. If anybody is interested, let me know - the price is right. (One TS, one RCA and the rest different Sylvanias.)


----------



## inphu510n

Yep, they're just a deconstructed tube base, a standard 7 pin socket and a ring of pvc tubing encased in heat shrink tubing.
  Rudimentary and something I could do in my sleep.
  I'd rather have them professionally manufactured so that the sockets fit correctly and people using other amps can switch out 6ak5 for 6AU6 types.


----------



## Acapella11

Quote: 





mab1376 said:


> would this be a worth while upgrade from the 6N6P-IR? http://www.ebay.com/itm/NEW-SOVTEK-6H30PI-Supertube-ARC-Conrad-Johnson-BAT-2PCS-/120748685916?pt=Vintage_Electronics_R2&hash=item1c1d2eba5c
> 
> or even these: http://www.ebay.com/itm/MATCHED-PAIR-6N30P-DR-6H30-Pi-SUPER-TUBES-UNUSED-TESTED-/161031708331?pt=Vintage_Electronics_R2&hash=item257e3cdeab
> 
> ...


 
   
  Hi mab1376, The DR would be the option. But to be fair, if you buy it, you will always consider that a pre-1984 tube might be better. I would recommend to sit the time out that you need to better afford a pre-1984 DR and just buy it then. At least then you sit comfortable knowing you got the best you could get.
   
  Today, my Mullard CV417 triode arrived from Spain and I have come across the probably most unusual customs labeling. It is a stamp directly stuck onto the tube...^^ See for yourself.


----------



## MIKELAP

Quote: 





acapella11 said:


> Hi mab1376, The DR would be the option. But to be fair, if you buy it, you will always consider that a pre-1984 tube might be better. I would recommend to sit the time out that you need to better afford a pre-1984 DR and just buy it then. At least then you sit comfortable knowing you got the best you could get.
> 
> Today, my Mullard CV417 triode arrived from Spain and I have come across the probably most unusual customs labeling. It is a stamp directly stuck onto the tube...^^ See for yourself.


 
  An audio enthusiast for shure !


----------



## Audiofanboy

Mordy, OK so you had tested the "final" O-getter version of the TS 6AV6 and found them underwhelming. Interestingly, the only "triode" I've tested that convinced me that it was worth it to continue investigating is a 6AV6, which sounds dramatically different from the "pure triode" I tested, hence my question about the Tung-Sol tubes.
   
  Acapella, that's pretty fascinating to have such a huge and obvious customs label stuck on a tube lol
   
  mab1376, for -DR tubes, as I've mentioned to a few people here in private, reports are that "something" changed in the factory in 1984, independently from political factors -a metal alloy metal machine was sold for scrap apparently- which slightly changed the production of tubes. So, tubes from 1979 to 1983 would be my recommendation, just to make sure you get the best bang for your buck. This being said, most of reviews of 6N30P-DR tubes on the web are of post-1984 tubes, mainly 1986 and 1988 -for some obscure reason- and people still seem to be quite ecstatic about them, and I'm pretty sure they tell the truth (unlike 90s -DRs which are a scam apart from hypothetical '90 to '92 production). I would still aim for the earlier ones, if only for the reselling value and potential better audio quality just in case. If you want to "invest" you could get a quad of tubes, as it is harder to fake.


----------



## mab1376

Quote: 





audiofanboy said:


> Mordy, OK so you had tested the "final" O-getter version of the TS 6AV6 and found them underwhelming. Interestingly, the only "triode" I've tested that convinced me that it was worth it to continue investigating is a 6AV6, which sounds dramatically different from the "pure triode" I tested, hence my question about the Tung-Sol tubes.
> 
> Acapella, that's pretty fascinating to have such a huge and obvious customs label stuck on a tube lol
> 
> mab1376, for -DR tubes, as I've mentioned to a few people here in private, reports are that "something" changed in the factory in 1984, independently from political factors -a metal alloy metal machine was sold for scrap apparently- which slightly changed the production of tubes. So, tubes from 1979 to 1983 would be my recommendation, just to make sure you get the best bang for your buck. This being said, most of reviews of 6N30P-DR tubes on the web are of post-1984 tubes, mainly 1986 and 1988 -for some obscure reason- and people still seem to be quite ecstatic about them, and I'm pretty sure they tell the truth (unlike 90s -DRs which are a scam apart from hypothetical '90 to '92 production). I would still aim for the earlier ones, if only for the reselling value and potential better audio quality just in case. If you want to "invest" you could get a quad of tubes, as it is harder to fake.


 
  Great info, I'll keep that in mind. unfortunately $250 for a set of power tubes is outta my reach.
   
  I would be willing to spend about $100, but like you said, I would want know I'm not missing out on something greater by buying a post-'82-'83 tube.


----------



## mojorisin35

some information from http://www.aca.gr/index/hiend/hiendArticles?row=1988 about:
 recognizing 6H30 - 6N30 tubes   


  This article is about how to understand and recognize 6H30, 6N30 tubes...  Back in mid 1990’s Mr. Victor Khomenko, founder and owner of Balanced Audio Technologies (BAT), adopted an unknown till then small Russian dual triode tube to update his VK50 pre amp to SE, the 6H30DR...
  He had done this due to this tube’s advanced specs that were long different and quite better than the other most common Russian tube 6922, so he called this tube ‘Supertube’... And he was right... 6H30 has Amplification factor 15, Plate resistance 200 Ω, Transconductance 72 mA/V and it is very linear...
 As time goes by  After that time, many hi-end manufacturers developed machines based on 6H30, with excellent results, so this tube became very popular and regarding the military Russian version DR, very expensive… Audio Research, Ayon, Consonance, Conrad Johnson, Mod Wright, Cary, Tenor and lately Greek hi-end company Trulife Audio (TLA) are some of them...


 


_Original Russian 6N30's Dr's ... Up left blue-yellow box, Up right bulk white box, down left green box_
 And Some More 


  In 1992 Reflector Plant was closed so the production of 6H30DR stopped… BAT claimed that bought the total stock of all the existing tubes, the old military version DR’s...
  In 1999 Reflector Plant was bought by Americans and the production of 6H30 started again… The early tubes were of extremely poor quality, they have not reached an acceptable level until around 2004… After that time point, the new production 6H30’s are of a good quality, most of today’s hi-end machines sound excellent with them...
  New tubes come today in two versions… The *‘Sovtek’ 6H30 pi EB* and the *‘Electro Harmonix’ 6H30 pi EH ‘goldpin’*… These two versions are from manufacturing view and in sound field exactly the same...
  New tubes as mentioned above are of good quality, but have never reached that of NOS pre 1990 DR’s in reliability, duration and sonics… On the DR’s data sheet is clearly mentioning duration of 10.000 hours and almost every tube has on glass the ‘OTK’ military periodic check!!! That’s why price have rise so high and that’s why some cunning people rebrand them to look like NOS DR’s...
 The New Production Russian 6H30's... *a) Electro Harmonix 6H30 Pi EH gold pin*


 


*b) The Sovteks 6H30 Pi EB*


 


 Recognizing original NOS DR's  So the point is, if someone wants today to use those excellent ‘old time’ Reflector 6H30 DR’s, how is going to recognize them and NOT get fooled to pay a ton for fake ones...
  Many people ‘wrongly’ state the paper box, the labeling and the color of text in recognizing original DR tubes… Many others also claim that OTK marking make a tube NOS… This is NOT true… There are NOS tubes in green box, in yellow-blue box and in white bulk box… They are all ok… Also there are NOS tubes with the Reflector sign or not, with black or gray text… That’s ok too… Also, it is very easy for someone to stamp an OTK mark on a new production tube...


 


  As I have searched and studied for a long time the 6H30’s and I have also bought many of them, I have found three (3) significant points that someone can *verify a NOS 6H30DR*...
 The deferences 
 *The plate flaps*... in NOS DR tubes are of smooth coloring, exactly same with the rest plate material, with NO shinny line defects as the new tubes
 *The hat type getter*... is much bigger in NOS DR’s than the new tubes
 *The lettering on the mica* under the plate does not exist in the NOS DR tubes (at least in those I have examined)
  The real NOS babies *two original 6H30 DR's... *



 And today's good kids *one new production 6H30 Pi EB *



 In the end  Today's production 6H30 tubes are of excellent quality and in an affordable price... You can use them in today's hi-end machines... Depending on the written above you can examine the existing 6H30 tubes in your machines to verify if they are original NOS...
  Also, if you wanna play with NOS DR's, you can pay attention to the above article... Keep in mind do not buy 6H30DR tubes if they don’t fulfill the above description... And be very careful on some *near east sellers* on ebay who want you to make themselves rich by selling rebranded tube monkeys...
*behind all fake DR's... look at the signed plate flaps!!!*


----------



## MIKELAP

Quote: 





mojorisin35 said:


> some information from http://www.aca.gr/index/hiend/hiendArticles?row=1988 about:
> recognizing 6H30 - 6N30 tubes
> 
> 
> ...


 
  Very interesting thanks


----------



## inphu510n

After reading that I'm tempted to try some of the EH 6H30Pi tubes.
  Not that I have 6N30P-DR's available for comparison.


----------



## MIKELAP

Quote: 





inphu510n said:


> After reading that I'm tempted to try some of the EH 6H30Pi tubes.
> Not that I have 6N30P-DR's available for comparison.


 
  I bought those EH6H30Pi gold pins about 6 months ago for $27.00 each at 20% off at Parts Connexion in Canada.if i remember it was a very noticeable change especially the power right off the bat compared to the 6N6P-I


----------



## maxdot

Where can i get the voskhods from for a good price?
   
  I saw a pair for 36 dollars but it seems a tad pricey to me


----------



## inphu510n

Quote: 





maxdot said:


> Where can i get the voskhods from for a good price?
> 
> I saw a pair for 36 dollars but it seems a tad pricey to me


 
  Just search eBay for "6J1P EV Gold".
  Matched doesn't matter as long as they test well.
  Don't buy the non gold grid versions, they're plentiful but not quite as nice as the gold grid version.


----------



## gibosi

Quote: 





maxdot said:


> Where can i get the voskhods from for a good price?
> 
> I saw a pair for 36 dollars but it seems a tad pricey to me


 
   
  I purchased two pairs from this vendor:
   
  http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=130436695928&ssPageName=ADME:L:OC:US:3160
   
  $3.00 a pair plus $12.00 shipping for a total of $15.00.


----------



## Audiofanboy

Quote: 





mojorisin35 said:


> Today's production 6H30 tubes are of excellent quality and in an affordable price... You can use them in today's hi-end machines... Depending on the written above you can examine the existing 6H30 tubes in your machines to verify if they are original NOS...
> Also, if you wanna play with NOS DR's, you can pay attention to the above article... Keep in mind do not buy 6H30DR tubes if they don’t fulfill the above description... And be very careful on some *near east sellers* on ebay who want you to make themselves rich by selling rebranded tube monkeys...
> *behind all fake DR's... look at the signed plate flaps!!!*


 
   
  Mojorisin is exactly right about the plate flaps, which were the only "inner" part of the tube I had noticed was consistently different between -DRs and new production, though I hadn't had that many new ones, so I couldn't really be sure. New production flaps have visible signs of tooling and aren't the same uniform color. Thanks for confirming that, it's always good to have solid evidence when buying $250+ tubes!
   
  "_Near-East sellers_", you got that right... These guys have been trying to sell 1999 "-DRs" on and off for a while now; on some auctions they sell pretty and old -DRs -which are probably real for all I know- and on others (like tube packs for specific preamps with a quad of 6N30P and an extra tube) they discretely add 1999 fakes -without mentioning it of course... So, yeah, I'd be a bit careful with these sellers, especially considering they have like 3 different auctions and prices for what are supposed to be the same tubes, which just strikes me as odd (one of these has the cheapest price too obviously).


----------



## Nic Rhodes

anyone tried a CV850 (EF95 family I think), not a tube I know as the CV4010 (M8100) is far more available?


----------



## GCooper

Just as a general note on Soviet era tube technology-
   
  Tubes intended for use in military equipment-sonar buoys, weather balloons, etc., were designed by and large for high stress, long life environments. The Old Soviets were very concerned about making equipment that would survive an EMP and keep on ticking.
   
  Junk was simply not tolerated in the military (aside from some blunders like putting a nice hardwood deck on a VTOL aircraft landing pad. :-0) in the 1970's.
   
  Soviet gear was in general bulletproof, clunky, stable and of surprisingly good design with high tolerances for abuse.
   
  And I say that as someone who was professionally concerned with sussing out their intentions while stationed overseas.
   
  Though their nuclear subs did sound like toilets being flushed if one put their ear to a bucket in the ocean while a boat passed underneath. 
   
  I run Soviet milspec power tubes in my LDIII. These do seem to be an improvement over the stock set David provides.


----------



## gibosi

Quote: 





nic rhodes said:


> anyone tried a CV850 (EF95 family I think), not a tube I know as the CV4010 (M8100) is far more available?


 
   
  You might want to read a post by Audiofanboy, #1314, page 88 regarding CV tubes. In short, CVxxxx tubes, with four digits, are newer and considered to be better than the older CVxxx tubes with three digits. So while I have no experience with the CV850, the CV4010 is very likely superior.


----------



## Audiofanboy

Quote: 





gibosi said:


> You might want to read a post by Audiofanboy, #1314, page 88 regarding CV tubes. In short, CVxxxx tubes, with four digits, are newer and considered to be better than the older CVxxx tubes with three digits. So while I have no experience with the CV850, the CV4010 is very likely superior.


 

 Yeah the CV number for EF95 tubes are likely the best textbook example of how CV types worked as I wrote previously.
   
  Just note that -as far as Mullard tubes go- you can find different versions of the CV850:
   
  - Whyteleafe A factory CV850, with a D-getter, sounds pretty dry and large, unlike the CV4010/M8100
  - Mitcham factory CV850, O-getter, sounds like an inferior CV4010/M8100 but has similar characteristics as far as warmth and musicality go, pretty good tube as far as I remember
  (-Mitcham factory CV850, D-getter? I'm sure I've seen one before...)
   
  I actually have 2 pairs of Mitcham CV850 and 1 pair of Whyteleafe CV850, if anyone is curious to try them, as I am doubtful I will ever use them at this point.


----------



## Acapella11

Hidden in the middle of a previous post (post #1389), I have included some information for Russian tubes including information from post 19 in this thread: http://www.diyaudio.com/forums/tubes-valves/138426-6n6p-vs-6n6p-i-2.html. Some of the bits in this thread may be useful to read. The discussion is about 6N6P vs. 6N6P-I and includes details about 6H30P tubes as well.
  
  
 PS: Actually, I would suggest reading the thread anyways. For a thumbs up of the impulse tubes ("I"), check besides others posts 35 and 36. Also, check out post 48, quite interesting.


----------



## Audiofanboy

Quote: 





acapella11 said:


> Hidden in the middle of a previous post (post #1389), I have included some information for Russian tubes including information from post 19 in this threat: http://www.diyaudio.com/forums/tubes-valves/138426-6n6p-vs-6n6p-i-2.html. Some of the bits in this threat may be useful to read. The discussion is about 6N6P vs. 6N6P-I tubes.
 

 And again, a mention of some "alloy making machines" being sold for scrap by the time Gorbatchev was there, and thereby changing tube quality forever.
   
  I need to find that post -I believe by Victor Khomenko, the man who brought the 6N30P tube to the Western world- on some forum somewhere, where he explains the reports by factory workers of of those alloy machines being sold for scrap, and therefore the reason why 6N30P-DR _might_ sound different or be of lesser quality after 1984 -notice how I emphasize the word _might_.


----------



## mab1376

I really wish i could afford them, but the 6N6P-IR tubes are still amazing to me. I think they're an improvement over the new EH 6H30P-PI that came with the amp. Much cleaner sound, to me almost completely transparent which is exactly what you'd want from a power tube.


----------



## mordy

Could not find a reference for the alloy machines, but found an interesting article about Victor Khomenko - link below. However, I came across a startling item: apparently old worn out tubes can be resuscitated:
   
  "I mentioned to Victor, because I knew of his background with tubes, that I had an old Fisher amplifier that had bad tubes in it, and I needed to replace them. He said, don't replace them, just bring them in. And so I did. Victor proceeded to hook them up to his equipment at the bench and resuscitated them.
*Victor Khomenko: *It's actually very simple. I spent my years at university studying electronic emission. We made our own cathodes, and part of it is a process of activation. As a tube wears out, you can go through the same process again, and reactivate the tube by applying particular voltages."
   
   
  http://www.stereophile.com/interviews/767


----------



## Nic Rhodes

Thanks for the CV850 info, I have pulled the trigger and bought a few to try. It seemed the most sensible idea! Do any of you know a 6xxx to 8xxx tube PQ / SQ version on the EF95? [Fine with UK examples, primarily interested in US ones].


----------



## gibosi

Quote: 





nic rhodes said:


> ..........Do any of you know a 6xxx to 8xxx tube PQ / SQ version on the EF95? [Fine with UK examples, primarily interested in US ones].


 
   
  I have no idea what "a 6xxx to 8xxx tube PQ / SQ version" is? Can you explain?


----------



## Nic Rhodes

Sorry, for say an EF94 / 6AU6  we have 6136, 7543 amd 8425. For 6J4 we have 8532, 6AH6 has 6485, 8136 is close to EF91 (actually 6DK6) etc etc. 6xxx to 8xxx tubes are often a special quality type (SQ) or some premium quality selected characteristic tube (PQ). So 8425 is a premium 6AU6 and 7543 is a low hum, low microphonic 6AU6. When I first looked at all these tubes 20 years ago I only identified premium UK numbered EF95s (M8100, CV4010) and the closest I got was 6069 which was basically just another number on the M8100, CV4010 types. I never found good options for EF92s, EF95s from US types (most of my tubes are UK types because that is where I live and have better access to these).


----------



## Audiofanboy

Quote: 





nic rhodes said:


> Sorry, for say an EF94 / 6AU6  we have 6136, 7543 amd 8425. For 6J4 we have 8532, 6AH6 has 6485, 8136 is close to EF91 (actually 6DK6) etc etc. 6xxx to 8xxx tubes are often a special quality type (SQ) or some premium quality selected characteristic tube (PQ). So 8425 is a premium 6AU6 and 7543 is a low hum, low microphonic 6AU6. When I first looked at all these tubes 20 years ago I only identified premium UK numbered EF95s (M8100, CV4010) and the closest I got was 6069 which was basically just another number on the M8100, CV4010 types. I never found good options for EF92s, EF95s from US types (most of my tubes are UK types because that is where I live and have better access to these).


 

 As far as EF95/6AK5 tubes go, the US 5654(W) is supposed to be the "special type". Though I've seen the number "6069" written on some 60's Mitcham-made CV4010, it seems to be more of a theoretical US equivalent numbering (like 6064 and 6065 for EF91 et EF92) that wasn't actually used in the US.
   
  I'm sure you could find "premium" US EF95 in theory though, but I think a lot of the special 6AK5 just ended up getting another name (tube type) altogether because they would have been made for specific applications with slightly different -but different enough- characteristics; after all, the 6AK5 is about as basic as you can go in terms of pentodes, so anything extra added to it kind of changes that.
   
  You do have the Western Electric 403A and 403B, but those aren't so much special types than they are WE versions of the 6AK5, again for specific applications.
   
  You should be able to find -at least in theory- some Mullard "10M" EF95 tubes, rated for 10000 hours, though I'm never seen any and there would be no guarantee that Mullard actually made them -they could have been sourced anywhere in Europe or even Japan in later times.
   
  Anyway, good luck looking; I'm done with 6AK5 types if just because they reach silly prices...


----------



## duncan1

Just out of interest I have a large collection of tubes/valves with many unusual ones as this is mainly a US site maybe you will know more about this one=tube type 6J6-DA-30-069-ORD-1   /  MIL-P-75 / DATE PKD NOV. 1954 /MFRS-PT # 807835-1. Sperry gyroscope company division of the  Sperry corporation. This tube unusually for a small B7G tube is rated for use in a transmitter[low wattage output] as well as other uses. Packed in plain brown cardboard the glass extrusion at the top is painted a reddish color.


----------



## Audiofanboy

Quote: 





duncan1 said:


> Just out of interest I have a large collection of tubes/valves with many unusual ones as this is mainly a US site maybe you will know more about this one=tube type 6J6-DA-30-069-ORD-1   /  MIL-P-75 / DATE PKD NOV. 1954 /MFRS-PT # 807835-1. Sperry gyroscope company division of the  Sperry corporation. This tube unusually for a small B7G tube is rated for use in a transmitter[low wattage output] as well as other uses. Packed in plain brown cardboard the glass extrusion at the top is painted a reddish color.


 
   
  In theory, a 6J6 could be used in our amps. It's a 7-pin base double triode with a common cathode, which means that both triodes could be wired to work together (parallel?), therefore forming a single triode.
   
  I'd actually spotted that tube type a while back since its seemed interesting, but its pinout turns out to be too different from a 6AK5 or 6AU6 type to be easily used without a thoroughly different adapter...


----------



## gibosi

Recently, I received a couple small packages in the mail and thought they might be of interest:
   
  Mullard EF94 manufactured in the Blackburn factory in 1962.
   

   
  I usually do not post pictures of boxes, but thought these were pretty neat:
   

   
  Dow Radio was one of southern California's leading electronics stores back in the day, and these could be had for $1.26 each!
   
  (A Dow Radio advertisement from around that time: http://www.vintageadstock.com/products/1966-dow-radio-sony-solid-state-sonymatic-stereo-vintage-advertisement)
   
  And in another package, a pair of premium Amperex 6687/E91H (6BY6). These were made in the Philips Heerlen/Holland factory in 1962 or 1972... Can't figure out which.....
   

   
  These tubes are taller than the standard 6AU6. Also of interest is some printing on top of the tube: 05M. However, I have no idea what this sequence means....
   

   
  Hope to get to these soon. However, now that the growing season is upon us, I find myself spending an inordinate amount of time in my garden doing battle with the weeds! lol


----------



## mab1376

Got my TS 6BE6 today, compared directly to the TS 6AH6WA and they are just a hair brighter, but without sacrificing the low end. Soundstage seems more spacious as well. This is only after about 45 min of burn in, so hopefully time with be good to them.
   
  I was using the 2-7 strap on the 6AH6WA and no strap on the 6BE6.
   
  I'm still waiting on Telefunken EH900S with gold pins and also Telefunken 6BE6. I also still have GE 6AU6WA on hand untested still, I hope to get to them soon.
   
  I was trying to find the TFK 6BE6W to no avail, has anyone tried any 6BE6W variants?
   
  This has been my defacto test track so far, the FLAC version obviously:


----------



## gibosi

Quote: 





mab1376 said:


> I was trying to find the TFK 6BE6W to no avail, has anyone tried any 6BE6W variants?


 
   
  I have the GE 6BE6W. Unfortunately, I haven't had a chance to compare these directly with the TS 6485 or the GE 8425A. However, you can find my initial impressions in post #1291, page 87. Keep in mind that I was using the EF92 setting, as at that time, it was the recommended setting for heptodes.


----------



## Acapella11

Quote: 





mab1376 said:


> Got my TS 6BE6 today, compared directly to the TS 6AH6WA and they are just a hair brighter, but without sacrificing the low end. Soundstage seems more spacious as well. This is only after about 45 min of burn in, so hopefully time with be good to them.
> 
> I was using the 2-7 strap on the 6AH6WA and no strap on the 6BE6.


 
   
  Hi mab1376, the treble should be reduced and become "round" during burn in. Agree, soundstage and bass are plus points for the 6BE6.


----------



## gibosi

After reading Mordy's strong favorable impressions of the Westinghouse matched Tektronix 8425/6AU6, I decided to purchase a pair. However, the "pair" I received were ill-matched. One was old-tech with dark-gray plates, a D-getter and the other was new-tech with light-gray plates and an O-getter. Further, the older tube was not labeled as 8425. Although the eBay vendor called these a"matched" pair, they didn't seem so to me and I put them aside while I explored the world of triodes.
   

   
  Upon returning to the world of pentodes, I decided to to try to find a suitable mate for each of these and I now have two pair, one old-tech and one new-tech.

   

   

  Both old-tech tubes were both manufactured in 1962, so a pretty good match, I think. But again, these are just ordinary Westinghouse 6AU6. They are not 8425 and there is nothing special about them.
   

   

  Unfortunately, there are no visible date codes on the new-tech tubes, but they appear to be identical and both have 6AU6 8425 etched into the glass, so again, a pretty good match, I think. And these are 8425, so considered special quality.
   
  First, comparing the two Westinghouse pairs, they are virtually indistinguishable to my ears. The older pair might be just a tad bit brighter, but I am not sure... Otherwise, the same wide sound stage, detail, clarity and full, punchy bass.
   
  The W 8425 are very good tubes and my conclusions are similar to those of Mordy. Compared to the GE 8425, the W 8425 seem to be a little brighter, with a wider sound stage and a full, punchy bass. Perhaps because of the added brightness and bass, they also seem to be a little louder than the GE 8425. And like Mordy, I would rank the W 8425 above the GE 8425.
   
  Compared to the TS 6485, again, my conclusions are similar to those of Mordy. I find the W 8425 to be a bit warmer and brighter. The bass seems to have more punch and power, plus it is fuller and rounder.  However in the end, the W 8425 lack the incredible clarity, detail and balance that keep the TS 6485 on top of the heap for me.
   
  But in the end, each of these three are very good tubes, and sound much more similar than different. I don't think anyone can go wrong with any of these.


----------



## Acapella11

Quote: 





gibosi said:


> First, comparing the two Westinghouse pairs, they are virtually indistinguishable to my ears. The older pair might be just a tad bit brighter, but I am not sure... Otherwise, the same wide sound stage, detail, clarity and full, punchy bass.
> The W 8425 are very good tubes and my conclusions are similar to those of Mordy. Compared to the GE 8425, the W 8425 seem to be a little brighter, with a wider sound stage and a full, punchy bass. Perhaps because of the added brightness and bass, they also seem to be a little louder than the GE 8425. And like Mordy, I would rank the W 8425 above the GE 8425.
> 
> Compared to the TS 6485, again, my conclusions are similar to those of Mordy. I find the W 8425 to be a bit warmer and brighter. The bass seems to have more punch and power, plus it is fuller and rounder.  However in the end, the W 8425 lack the incredible clarity, detail and balance that keep the TS 6485 on top of the heap for me.
> ...


 
   
  Hi Gibosi, If the stage for the Westinghouse tube is large, then you may find that the instruments or singers are not as close to you. This often gives the impression of lesser detail because you cannot "grip" them as well. But in fact because of the large stage, everything in the room just appears further away and a bit smaller. It is a natural side effect of a deeper stage. I experienced this effect with the wide and deep stage of the 6BE6. The exact opposite of this would be the triode, I guess. Being very clear but without a depth (at least my 6AQ4s are like this). Do you think, this is the case? This may put the Westinghouse tube a bit higher on my list.


----------



## mordy

Hi G,
   
  I think that you will find that as you put more hours on these sets of tubes (TS vs W) the differences will be smaller with the TS having a punchier bass with more slam than the Westinghouse. Otherwise they are very similar. (My Tung Sol observations are based on 1960s 6AH6WA tubes.)
   
  However, at least for me, after listening to these wonderful tubes for a while the "wow factor" diminishes and they become the "New Normal."
  Some people say that "normal" means that you don't notice anything; everything just feels right.
   
  So how do you bring back the "wow"? Well, you could just pop in one of the other types of tubes again such as the EF95s and so on. Suddenly something is missing, something bothers you when you are listening. Not enough bass, too much sibilance or muddiness. Or you realize when you get startled playing a recording with a vocal that there really isn't anybody else in the room. These tubes are really that realistic on some recordings! Sometimes it feels like the musician is right in front of you! Or you could listen critically to old well known recordings and discover new nuances in the music, especially in the background.
   
  My hunch is that with all the excellent work of so many dedicated people on this forum we have perhaps found the best choices in driver tubes. What is left?
   
  The next frontier is to find excellent inexpensive power tubes made in USA. I am hopeful that somebody will come up with a conversion or modification allowing different kinds of power tubes to be used that will better or equal the Russian DR tubes!
   
  Suggestions?


----------



## Audiofanboy

Quote: 





mordy said:


> My hunch is that with all the excellent work of so many dedicated people on this forum we have perhaps found the best choices in driver tubes. What is left?
> 
> The next frontier is to find excellent inexpensive power tubes made in USA. I am hopeful that somebody will come up with a conversion or modification allowing different kinds of power tubes to be used that will better or equal the Russian DR tubes!
> 
> Suggestions?


 
   
  We're getting close to finding the best choice of driver tubes, but we're not quite there yet lol. After the 6485 glory and other EF94 and heptode -ongoing- adventures, I'm pretty sure we haven't reached the skies yet. I mean, just read the comments people with Schiit Lyrs or other fancy headamps and preamps write about the 6922 or 12AX7/12AT7 types and you can imagine just how much is still out there that we haven't tried!
   
  I still see a wiiiide number of possibilities to investigate: new pentodes (low noise EF94 for example), heptodes (Acapella has got us covered on those), those double diode-triodes (which I'm thoroughly investigating), 9-pin double triodes (imagine a 6922 or center-tapped 12AX7 with its triodes run in parallel on a 9-to-7-pin adapter), many innovative ideas have yet to be tested -and that's just for driver tubes, though challenging the DRs as power tubes may prove quite challenging, they aren't referred to as "supertubes" for no reason.
   
  About US tubes, I find myself drifting away little by little from both US tubes because they aren't the easiest to get here in Europe, and also from UK -Mullard- type sound as well, as I keep finding it just too warm and lush in the mids -which most people love.
   
  So, while investigating 6AV6/EBC91 tubes, I tried to find different tube manufacturers. A 6AV6 tubes is commonly referred to as "half of a 12AX7" and most brands who made 12AX7 tubes also made 6AV/EBC91 tubes, so I figured why not try a few of those best-in-class brands that make people spend $160 for a pair of 12AX7?
   
  Those brands turn out to virtually all be European, whether they are Philips group -Mullard, Philips, Miniwatt, Dario, Valvo...- or, for example, German -Siemens, Lorenz, Telefunken, Valvo (yes twice Valvo as tubes could be Philips-sourced or German-made, just like Siemens btw).
   
  In order to test that, I ordered -at a higher price for some- a few of these uncommon brands of 6AV6/EBC91, namely:
  - Philips -Mullard Fleetwood-made- 6AV6
  - Lorenz -supposedly actual Lorenz factory-sourced and best-in-class, not SEL Lorenz or ITT Lorenz- old-world EBC91
  - Telefunken -genuine West-Germany Ulm-factory produced- O-getter EBC91 (genuine Tele 12AX7 are supposed to be the best you can get with Philips Holland Heerlen factory-made Amperex tubes -detail vs warmth- so I assume these could be nice too -the pics I got from the seller look great at any rate)
  - GE JAN 6AV6 -just to make sure I don't upset anyone lol
   
  And I will most likely try and find more, albeit at cheaper prices and perhaps not all NOS NIB.
   
  Anyway, I have high hope for some of these tubes, as their 12AX7 brethren are held in _high _esteem by audiophiles around the globe, and many people have reported 6AV6 triodes -for all intents and purposes we can ignore the diodes- to work extremely well as voltage gain signal tubes, though reports are a bit shy on google, but it drives the prices down so it's OK I guess.
   
  Edit: The reason why I'm so fascinated by 6AV6 tubes is obviously because my _mystery_ Pinnacle 6AV6/EBC91 tubes are my current best tubes -more detailed and less lush than my TS 6485, and earth-shattering dry infra-bass, which I had never managed to get on my amp since I switched to low sensitivity orthos- that have not left the sockets since I plugged them in 2 and some weeks ago. And that kind of enticed me to try more and less mysterious ones, as you would expect...


----------



## Acapella11

Quote: 





> Originally Posted by *mordy* /img/forum/go_quote.gif
> My hunch is that with all the excellent work of so many dedicated people on this forum we have perhaps found the best choices in driver tubes. What is left?
> 
> The next frontier is to find excellent inexpensive power tubes made in USA. I am hopeful that somebody will come up with a conversion or modification allowing different kinds of power tubes to be used that will better or equal the Russian DR tubes!
> ...


 
   
  Mordy and everyone else obviously =),
  The ECC802 (802S), also known as 12AU7, is a direct replacement, only it is lower gain I think. It is known as a good HiFi tube as well. They can be used with 6.3V and 12.6 V. Cathode current is 0.3 mA at 6.3V, for a 6N6P it is 0.75 mA. Prices on Ebay vary between $25 for a pair and $2100 (!) for a matched quad.
   
   
  Quote: 





audiofanboy said:


> *About US tubes, I find myself drifting away little by little from both US tubes because they aren't the easiest to get here in Europe*, and also from UK -Mullard- type sound as well, as I keep finding it just too warm and lush in the mids -which most people love.


 
   
  Fully agree here 
   
  Quote: 





> Edit: The reason why I'm so fascinated by 6AV6 tubes is obviously because my _mystery_ Pinnacle 6AV6/EBC91 tubes are my current best tubes -more detailed and less lush than my TS 6485, and earth-shattering dry infra-bass, which I had never managed to get on my amp since I switched to low sensitivity orthos- that have not left the sockets since I plugged them in 2 and some weeks ago. And that kind of enticed me to try more and less mysterious ones, as you would expect...


 
   
  For Pinnacle tubes:
   
  Quote: 





> http://www.head-fi.org/t/544932/pinnacle-vacuum-tubes
> 
> Originally Posted by *InnerSpace* /img/forum/go_quote.gif
> 
> IIRC Pinnacle was a kind of European broker or re-boxer operation back when a tube was just a tube ... they would pick up big stocks of tubes from random European and Russian manufacturers, sometimes from military surplus, relabel them "Pinnacle", and then sell them into the trade via mom-and-pop stores.  So they're a bit of a crapshoot ... some were excellent items, some weren't, depending on the source and the batch received.


 
   
  Updated 3/6/2013


----------



## gibosi

Quote: 





			
				mordy said:
			
		

> I think that you will find that as you put more hours on these sets of tubes (TS vs W) the differences will be smaller with the TS having a punchier bass with more slam than the Westinghouse. Otherwise they are very similar. (My Tung Sol observations are based on 1960s 6AH6WA tubes.)


 
   
  It is true that I do not have that many hours on either the Westinghouse 8425 or the Tung-Sol 6485, so I will be interested to see how they change over time....
   


> Originally posted by *Acapella11*
> 
> If the stage for the Westinghouse tube is large, then you may find that the instruments or singers are not as close to you. This often gives the impression of lesser detail because you cannot "grip" them as well. But in fact because of the large stage, everything in the room just appears further away and a bit smaller. It is a natural side effect of a deeper stage. I experienced this effect with the wide and deep stage of the 6BE6.


 
   
  This is an interesting observation. And as I am now off to the land of heptodes using the EF95 settings (1959 GE 5750/6BE6W, 1964 RCA JRC 5915/6BY6, and am now burning in the Amperex 6687/E91K/6BY6 that I just received), I will keep this in mind. But even if true, there is still something very seductive about the incredible clarity, detail and balance I hear with the TS 6485.


----------



## Nic Rhodes

Quote: 





audiofanboy said:


> As far as EF95/6AK5 tubes go, the US 5654(W) is supposed to be the "special type". Though I've seen the number "6069" written on some 60's Mitcham-made CV4010, it seems to be more of a theoretical US equivalent numbering (like 6064 and 6065 for EF91 et EF92) that wasn't actually used in the US.
> 
> I'm sure you could find "premium" US EF95 in theory though, but I think a lot of the special 6AK5 just ended up getting another name (tube type) altogether because they would have been made for specific applications with slightly different -but different enough- characteristics; after all, the 6AK5 is about as basic as you can go in terms of pentodes, so anything extra added to it kind of changes that.
> 
> ...


 
  Thanks Audiofanboy, that makes lot's of sense. It tallies with what I had found aready, I guess looking for 6xxx + tubes on an old design was optimistic on my part. Raytheon pushed the 6AK5 in 1946 to make the 6AH6 with some difficulty at the time, so it shows even then it was being developed further way back then.


----------



## hypnos1

Quote: 





mordy said:


> Hi G,
> 
> I think that you will find that as you put more hours on these sets of tubes (TS vs W) the differences will be smaller with the TS having a punchier bass with more slam than the Westinghouse. Otherwise they are very similar. (My Tung Sol observations are based on 1960s 6AH6WA tubes.)
> 
> ...


 
  Hi mordy, and anyone else who may be interested.
   
  Re best choices in driver tubes - until Audiofanboy continues further in his awesome quest(!), I wonder if anyone else has tried the Siemens EK90 (6BE6) . Having been mightily impressed with the Sylvania Gold Brand 5750s (6BE6) on EF95, no strap of course, with all the qualities described by Acapella11, the Siemens have been delivering even MORE of the same in all departments, especially detail/individual instrument placement . I think my beloved TS 6485s have been usurped!!. (The lovely thick copper inner wire from the (shiny) pins boded well from the start...)
   
  Would love to hear anyone else's opinion...
   
  BTW mine came from a german outfit - tubeshop-24 on ebay.co.uk (european union) -  with a designation 7/77 @ £5.03ea.


----------



## Acapella11

Quote: 





hypnos1 said:


> Hi mordy, and anyone else who may be interested.
> 
> Re best choices in driver tubes - until Audiofanboy continues further in his awesome quest(!), I wonder if anyone else has tried the Siemens EK90 (6BE6) . Having been mightily impressed with the Sylvania Gold Brand 5750s (6BE6) on EF95, no strap of course, with all the qualities described by Acapella11, the Siemens have been delivering even MORE of the same in all departments, especially detail/individual instrument placement . I think my beloved TS 6485s have been usurped!!. (The lovely thick copper inner wire from the (shiny) pins boded well from the start...)
> 
> ...


 
   
  Thanks for sharing this hypnos1, I will get those.


----------



## mab1376

I've been looking for German originating 6BE6 tubes, I've ordered a set of Telefunken's from nostubestore and they shipped yesterday. I was really impressed with the tonal balance of the TFK 6AK5W which is what prompted me to try the 6BE6 variant as well as the EH900S that I'm waiting on with gold pins.
   
  this is the only singular TFK 6BE6W i could find so far: http://www.ebay.com/itm/6BE6W-CV4012-5750-EK90-TELEFUNKEN-NOS-Tube-Rohre-Lampe-TSF-Valvola-Valvula-/400489989918?pt=Vintage_Electronics_R2&hash=item5d3f10471e


----------



## Oskari

Quote: 





mab1376 said:


> I've been looking for German originating 6BE6 tubes


 
   
  Did you also search for EK90? The Germans were more likely to use the equivalent European code.
   
  If you are searching on eBay, make sure your _advanced _search is worldwide.


----------



## mab1376

Quote: 





oskari said:


> Did you also search for EK90? The Germans were more likely to use the equivalent European code.
> 
> If you are searching on eBay, make sure your _advanced _search is worldwide.


 
   
  Thanks! I'll give it a shot.


----------



## gibosi

Some of you might remember that I recently purchased two pairs of vintage socket testers with the idea of modifying them to be used as socket converters, one pair with pins 2-7 connected and the other with pins 5-7 connected.
   

   
  Took them apart today and a friend who repairs electronic equipment for a living was kind enough to solder the requisite pins together. Put them back together, checked them with a VOM and they passed with flying colors.
   

   
  However, when I returned home and plugged them in, I heard what sounds like a strong ground hum, with the 2-7 converters being the worst. And this got me thinking about the converters some of you received from China....
   


mikelap said:


> Regarding the sockets it seems they did not send me the right ones they sent the B models and we need the A model there picture


 
   
  It seems to me that this vendor should understand very well how to make converters, and thus, there must be a good reason why they leave one of the pins disconnected. I am guessing that having both pins connected is responsible for this noise. However, why this works differently than strapping in the socket itself is not at all clear to me. Perhaps, the extra circuitry provided by the socket tester allows current to flow where it shouldn't?
   
  So I think I need to cut one of the connected pins off to eliminate this problem. When using the 2-7 converter, it is most important that pin 2 is not cut (which corresponds to the A model above), as the LD is designed with the expectation that pin 2 is the cathode. Pin 7 is typically one of the extra grids and we don't want to put any current on this pin. When using the 5-7 converter, it is most important that pin 5 is not cut, as the LD is designed with the expectation that pin 5 is the anode. Again, we don't want to put any current on pin 7 .
   
  However, before I go forward with this mutilation, I am hoping that someone who understands circuit analysis much better than I will weigh in.
   
  Thanks!


----------



## zedmeco

I received the "b" type converters and to be honest, I did not try them as I had read they did not work. When the manufacturers got in touch with me saying they were sending the type "A" converters I told them not to as the mod is to drop the wire into the socket 2-7, so all the pins should be connected. I sent them a copy of the relevant post with the photo of the wire in the socket. So my question is, will it work or not?


----------



## hypnos1

Hi guys.
   
  Further to my last post (#1460) re the Siemens EK90s (6BE6), having wondered whether my ears were just 'super clear' that day I put some Genesis in the Audiolab and - WOW! My head was filled with stuff I never knew was there...and  as for 'Alone tonight', I swore I was in some vast cathedral - the sort of sound you only get normally from a good organ in a good (acoustic wise) church. The echo effect was not excessive though - voice and instruments were still clear and well delineated - I thought I was in heaven!
  The less dramatic 'Guide vocal' was equally impressive but in a different way, of course - to achieve this in a much simpler track I would imagine is quite a feat, both for the recording engineer AND the sound reproduction equipment...
  Can't wait to try some heavy duty (and lightweight) classical next...
   
  As you can probably tell, I have fallen in love with these tubes! I hope they might bring similar joy to other ears...


----------



## gibosi

Quote: 





zedmeco said:


> I received the "b" type converters and to be honest, I did not try them as I had read they did not work. When the manufacturers got in touch with me saying they were sending the type "A" converters I told them not to as the mod is to drop the wire into the socket 2-7, so all the pins should be connected. I sent them a copy of the relevant post with the photo of the wire in the socket. So my question is, will it work or not?


 
   
  We will have to wait until someone gets a set of these "A"  converters to learn if they will work. I cut pin 7 off of my modified socket testers and there was no improvement, so I can only conclude that these old socket testers are just not suitable for this purpose...  (>_<)


----------



## mab1376

Quote: 





hypnos1 said:


> Hi guys.
> 
> Further to my last post (#1460) re the Siemens EK90s (6BE6), having wondered whether my ears were just 'super clear' that day I put some Genesis in the Audiolab and - WOW! My head was filled with stuff I never knew was there...and  as for 'Alone tonight', I swore I was in some vast cathedral - the sort of sound you only get normally from a good organ in a good (acoustic wise) church. The echo effect was not excessive though - voice and instruments were still clear and well delineated - I thought I was in heaven!
> The less dramatic 'Guide vocal' was equally impressive but in a different way, of course - to achieve this in a much simpler track I would imagine is quite a feat, both for the recording engineer AND the sound reproduction equipment...
> ...


 
   
  They're actually the next on my list to try after I get my Tekefunken EK90's. Hopefully I get similar results from those!


----------



## hypnos1

Quote: 





mab1376 said:


> They're actually the next on my list to try after I get my Tekefunken EK90's. Hopefully I get similar results from those!


 
  Hi mab.
   
  Telefunkens eh? They should be really good - their 6AK5s and EH900Ss certainly seemed top of the pile - ergo they should at least match the Siemens I would imagine. I wish you all the best with them...
   
  As an addendum to my last post, anyone with Senn HD650s, or similar signature, I am sure would be very happy with these tubes - they brought a very welcome dose of 'excitement' to the otherwise 'safe & polite' cans. But, of course, everyone's ears are different!...


----------



## mab1376

Quote: 





hypnos1 said:


> Hi mab.
> 
> Telefunkens eh? They should be really good - their 6AK5s and EH900Ss certainly seemed top of the pile - ergo they should at least match the Siemens I would imagine. I wish you all the best with them...
> 
> As an addendum to my last post, anyone with Senn HD650s, or similar signature, I am sure would be very happy with these tubes - they brought a very welcome dose of 'excitement' to the otherwise 'safe & polite' cans. But, of course, everyone's ears are different!...


 
  The HD650 are the only phones I used on my LittleDot! 
	

	
	
		
		

		
			




   
  I agree with your statement about their "excitement"


----------



## Acapella11

To everyone on this forum,
  
 It may be interesting to note that we have reached page 99, which means... that more than half of the thread was involving the "new" tubes! On page 50 thegreat682 came up with 6CB6A tubes (see below) and we know the exciting journey since then. Also, this thread has developed itself to _the_ LD (I, II, III and IV) thread. The 50 pages are quite densely packed with information and written in about 3.5 months!
   
 Congrats to us and a special one to Audiofanboy of course =).
  
   
  Quote: 





thegreat682 said:


> I bought these little guys a few weeks ago and after 50+hrs of burn in they have replaced Mullard CV131s as my default "go-to" tube.  I have not read much of anything about rolling with the 6CB6A series of tubes and they can currently be had VERY cheap.  I received both of these for $5 shipped.  I'd like to know more information about them as I have not found any information on dating GE tubes, and I very quickly fell in love with their sound signature.  I'd highly recommend giving these a shot.  They also light up brighter than any tube I currently have which sure does look pretty


----------



## superdux

a question inbetween: i got my LD MKIII today and realised the tubes do stick in there hard. i couldn´t move them a bit with normal pressure applied. so if i want to roll tubes how hefty can i go about it. can i put a bit of pressing pressure on the tubes and yank them out? i´m a bit cautious cos these being brand new.


----------



## mab1376

Quote: 





acapella11 said:


> To everyone on this forum,
> 
> It may be interesting to note that we have reached page 99, which means... that more than half of the thread was involving the "new" tubes! On page 50 thegreat682 came up with 6CB6A tubes (see below) and we know the exciting journey since then. Also, this thread has developed itself to _the_ LD (I, II, III and IV) thread. The 50 pages are quite densely packed with information and written in about 3.5 months!
> 
> Congrats to us and a special one to Audiofanboy of course =). 
   
  We all owe Audiofanboy a debt of gratitude for his painstaking comprehensiveness!
   
  Keep on rolling!


----------



## john57

First I do not yank the tubes out. I use a very small rolling motion when pulling tubes out and take my time. I use socket savers if I am going to roll many tubes in the same amp. In my tube tester I use socket savers that can be screwed down to prevent the socket saver from moving but that would only work with amps that have point to point wiring which does not include the Little Dots. With the Little Dots I just hold on to the socket saver and remove the tube. Easy does it!


----------



## MIKELAP

Quote: 





superdux said:


> a question inbetween: i got my LD MKIII today and realised the tubes do stick in there hard. i couldn´t move them a bit with normal pressure applied. so if i want to roll tubes how hefty can i go about it. can i put a bit of pressing pressure on the tubes and yank them out? i´m a bit cautious cos these being brand new.


 

  I use a rubber finger so you get a very good grip on the tube works great.


----------



## mordy

Hi Superdux,
   
  As Mikeleap mentioned, the rubber fingers make it very easy to remove the tubes. In the US they are available in stationary stores or office supply stores. Usually they come 12/box and cost less than $3.00/box.
   
  The size you need is extra large (XL). These only work on driver tubes. The power tubes are a little wider, and I have not yet found a size that fits. On the other hand, it is rare to change the power tubes.
   
  The only drawback I found is that if the writing (silk screening) on the tube is poor, the rubber finger may remove it or part of it.
   
  In the beginning it took some effort to change the tubes, but after a while they come out much easier.
   
  Good luck tube rolling!


----------



## gibosi

As a number of posters have the TS-6BE6, I have decided to purchase a pair. But first I would like to know if I should get older tubes with D-getters? Or newer ones? Which ones are people using?


----------



## MIKELAP

Should be getting tube sockets next wednesday according to Canada Post possibly before.


----------



## mab1376

Quote: 





mikelap said:


> Should be getting tube sockets next wednesday according to Canada Post possibly before.


 
  Ooh, new power tube adapters?


----------



## MIKELAP

Those are my TS 6BE6 322  is probably manufacturer but the rest couldnt be month and year mordy i can see you what do you think and mordy its MIKELAP MIKE  LAP NOT LEAP LAP
	

	
	
		
		

		
		
	


	




 and dont say your sorry im just kidding you can call me what you want as long as you dont call me late for dinner ouuuuuuuuuuuuu  !!! ya i know dont quit your day job but hey i dont have a day job. enough of this heres the tube .


----------



## gibosi

Yes, 322 = Tung-Sol. Date is probably 1963, month 50, and factory #1. And I think I see a square D-getter on this tube.
   
  Thanks for posting this!


----------



## MIKELAP

Quote: 





mab1376 said:


> Ooh, new power tube adapters?


 
  Just a random picture .


----------



## mab1376

mikelap said:


> Just a random picture .




Oh damn, I thought you were gonna have some new uses for 5687 tubes as power tubes.


----------



## gibosi

Quote: 





john57 said:


> First I do not yank the tubes out. I use a very small rolling motion when pulling tubes out and take my time. I use socket savers if I am going to roll many tubes in the same amp. In my tube tester I use socket savers that can be screwed down to prevent the socket saver from moving but that would only work with amps that have point to point wiring which does not include the Little Dots. With the Little Dots I just hold on to the socket saver and remove the tube. Easy does it!


 
   
  Did you purchase these socket savers recently? If so, would you tell us where you got them?


----------



## gibosi

Preliminary Heptode Shoot-out (EF95 Setting)
   
  I have three heptodes, one 6BE6 and two 6BY6: GE JG 5750/6BE6W (1959, square getters), RCA JRC 5915/6BY6 (1964, halo getters), and Amperex 6687/E91H/6BY6 (probably 1972, halo getters). Unfortunately, I don't think anyone else is listening to these tubes. (I am currently looking for a pair of TS 6BE6, and expect shortly to have a pair of Siemens EK90 for comparison.)
   

   

   

   

  First, I find the two 6BY6 superior to the 6BE6. They seem to have a bit more air, a wider sound stage and better imaging, and they seem to be a bit more liquid. Otherwise, all of these tubes are very close in tonality. As you have read (and heard) before, the heptodes are open, spacious, clear, detailed and balanced. Really very nice tubes.
   
  Comparing the RCA and Amperex, I find the Amperex are superior, primarily because the RCA emphasizes background sounds a bit too much, rather like many of the triodes. These Amperex are very special tubes. But still, I need to spend some time directly comparing these to the TS 6485. And I am very much looking forward to seeing how they will compare to the TS 6BE6 and the Siemens EK90.


----------



## superdux

oh thx for replys and recomendations


----------



## Nic Rhodes

Those adapter should take E182CCs....


----------



## Audiofanboy

Wow, page 100 huh? It'd be a shame not to post really... You'd almost want to make this page a milestone with a recap or something lol.
   
  Gibosi, nice pick on those Philips-Heerlen-made Amperex tubes, I'm hardly surprised they sound good!
   
  Meanwhile, I'm still actively working on my 6AV6 skills. I tested -an intend to retest at some later point, just like for all those heptodes- my Philips 6AV6 I just received two days ago, clearly _not_ made by Mullard Fleetwood -hence hardly relevant as a factory- but by Mazda France. I can't say I really enjoyed these short of 10h of burn-in; I mean that they're OK tubes, but sub-par compared to what I'm expecting of 6AV6 type tubes -granted half of my expectations are speculation but the other half is my experience with my Pinnacle tubes; but I like to think I have pretty good intuition or at least decent intuition for a guy, and I usually end up finding what I want out of a given tube type I investigate, otherwise I pretty much just dismiss it without spending cash on it; usually...
   
  The GE JAN 6AV6? Well, I'd bought those just for kicks in the first place so they were meant more as a mile stick to compare other tube to than as everyday tubes -though you never know- and they pretty much had the sound I expected -both in quality and tonal balance. Meaty and round, typical US tubes, not the most defined -we're comparing triodes here, so the level is high regardless- but pleasant, probably an A+ or something tube; but it just doesn't cut it at this point compared to what I've heard and keep looking for -doesn't hold a candle to my TS 6485, Pinnacle EBC91 or the following tube. It still blows most tubes out of the water though, just not my best or second best; I'm guess I'm getting a little picky at this point lol; but why wouldn't I, considering what we keep finding and the constant improvement in sound quality?
   
  So there I was yesterday, hoping _something interesting would finally come in the mail today_, and it did, I got a box full of Lorenz EBC91. These have a side D-getter, old Lorenz logo, Lorenz date codes, and "made in Germany" written on them, which pretty much proves that they're actual Lorenz-made Lorenz tubes and old (50s) unlike later SEL Lorenz and ITT Lorenz tubes made by other manufacturers.
   
  At any rate, I still need to give these some more critical listening, but after 10 hours of burn-in, these are the best competition my Pinnacle EBC91 have seen for a month -themselves my current choice over the awesome TS 6485. The Lorenz EBC91 are ultra-detailed but never sterile; balanced, they have near perfect separation, and -unlike out of the box- have this -pardon me but I can't find a better word- almost erotic quality to them, not warm, not "2nd order harmonic rich" but just, well nice and pleasant; and they take 10 solid minutes to make their impression on you and drag you in, hence that adjective.
   
  I keep reading you should expect premium NOS German tubes to sound airy, detailed and have great soundstage -as far as the typical double-triodes everyone uses go- but people seemed to diverge when the actual listening pleasure or "tone" is addressed, either sterile and thin or detailed and glorious depending on who you ask (apparently you could virtually grade the best tubes on a Mullard-Blackburn -> Philips-Heerlen -> Telefunken-Berlin continuum that goes from cozy and warm to detailed and airy; so far I've found it to be somewhat true regardless of actual brands, so I'll keep investigating old German tubes for now).
   
  Speaking of German tubes, I'm hoping my Telefunken EBC91 will be with me before the weekend; just so I can kind of confirm that "tone continuum theory" or invalidate it as silly google tube lore. I'll try and specifically compare these, the Lorenz and the _mystery_ Pinnacle tubes -most likely East German or East European, so not that mysterious really. Expect a new German EBC91 shootout soon.
   
  Anyway, happy rolling and let's keep up the good work after page 100!


----------



## MIKELAP

Quote: 





mab1376 said:


> Oh damn, I thought you were gonna have some new uses for 5687 tubes as power tubes.


 
  like i said before when it comes to this stuff i will never have a scoop unfotunately..And now you know why but thats between you and me .


----------



## mordy

Hi G,
   
  I have been listening to heptode tubes as well. I have a pair of 1966 RCA 6BY6 tubes and also one each of a GE 6BY6 and a Sylvania 6BE6 tube.
   
  Unfortunately I am not enjoying these tubes. The bass is detailed and strong, but I found the treble to be rolled off and lacking energy. The presentation is detailed, but thin and lean and unexciting. There is no sizzle to the top end, and the sound overall is without real dynamics and life.
   
  I have been using the EF95 setting since I think that this was the recommended setting. Maybe it's me, my ears or my system (or settings?), but I can't share the enthusiasm of others with these heptodes.
   
  I have much better luck with 6AU6 tubes - a full bodied, balanced, detailed sound with amazing sound stage width and depth, instrument separation,  and this wonderful clear and warm quality to the sound. CLARITY......
   
  On a hunch I bought some 20+  6AU6 tubes for less than 50c each (untested, condition unknown, no returns; no boxes). A real estate agent found them them in a house they bought. I figured that nobody would save bad tubes for 50 years.
   
  There were no real finds in this batch; just plebeian 1960's Philco, Zenith, RCA and GE tubes and some unknowns without markings. Seems that the Philco and Zenith are re branded Sylvania tubes.
   
  So far I have tried three pairs. All worked fine. They all need about 10 hours to open up. Then the magic appears: Beautiful, full bodied and balanced sound. Right now I am trying a pair of Zenith/Sylvania tubes with thick copper posts. Somebody on this forum claimed that copper gives better sound. Don't know, but these sound better to begin with than the other two pairs.
   
  For you math majors out there: The tubes are marked 3  2
                                                                                     1  1
                                                                                     2  3
                                                                                     AJJ
   
  I am not good in math, but each column adds to 6. A obviously = 1, and J = 10. The second J must then be 100. Let's see: 6+6+1+10+100 = 123. Surprisingly, these are the same numerals as in the two columns: 312, 213 and 123. Lets interpret these findings:
   
  312 is the EIA code for Sylvania
  213 is the date code: The 13th week of 1962
  123 is my attempt to make a (confusing) joke. Get it? 
	

	
	
		
		

		
			




  Once you see the explanation of the confusing numbers they suddenly make sense - other makes usually don't list two columns vertically.
   
  What about AJJ? No idea; all I know that I am luxuriating in the sound of my 50c tubes....


----------



## MIKELAP

Missed my sockets today for the 6au6 will get them tomorror at post office d.....


----------



## Acapella11

Quote: 





mordy said:


> Hi G,
> 
> I have been listening to heptode tubes as well. I have a pair of 1966 RCA 6BY6 tubes and also one each of a GE 6BY6 and a Sylvania 6BE6 tube.
> 
> ...


 
   
  Hi Mordy, sorry to hear. I think it is probably due to poor system matching. The treble is not sparkly, it is round and refined, so if your system needs treble sizzle from the tubes to sound balanced, you won't get it. For me, they also perform better in the brighter Sennheisers and AKGs compared to the HE-500, which is darker than those and does not produce a stage as deep. The leanness likely comes from the deep stage, which places instruments further away, meaning they are smaller. Try them louder though. 
   
  PS: This also means that you presumably prefer them in the brighter EF91/92 setting.
  Quote: 





> Originally Posted by *gibosi* /img/forum/go_quote.gif
> 
> ...
> 
> ...


 
   
  Thanks for the interesting information. Reminds me, that I do not have any 6BY6 in my arsenal


----------



## mojorisin35

Any chance you would sell a pair out of the box to a fellow head fi'r?
  gary
  Quote: 





audiofanboy said:


> So there I was yesterday, hoping _something interesting would finally come in the mail today_, and it did, I got a box full of Lorenz EBC91. These have a side D-getter, old Lorenz logo, Lorenz date codes, and "made in Germany" written on them, which pretty much proves that they're actual Lorenz-made Lorenz tubes and old (50s) unlike later SEL Lorenz and ITT Lorenz tubes made by other manufacturers.


----------



## mab1376

After some comparison I found I like the 6AH6 better for Rock, Metal, and Electronic; whereas, I much prefer the 6BE6 for acoustic music, and softer rock.
   
  Not sure but it seems like the 6AH6 has a slightly higher gain which gives it a better sound with distortion in guitars and synths.


----------



## Audiofanboy

Quote: 





mojorisin35 said:


> Any chance you would sell a pair out of the box to a fellow head fi'r?
> gary


 

 Maybe? 
   
  I'm just joking lol; I originally had bought 4 pairs, just because shipping cost a ridiculous amount of money compared to the tubes themselves (like 20€ of shipping but cheap tubes).
   
  Sadly, I only got 7 Lorenz EBC91 and one extra 6AT6 type -different from 6AV6- and had also plotted with an other fellow head-fier to send him a pair in the first place, meaning I should have 3 pairs left eventually. I wrote to the seller, and will probably get my last tube at some point though, so just PM me and I'm sure we'll be able to work something out for one pair. 
	

	
	
		
		

		
		
	


	



   
  Interestingly, one seller on ebay just sold -after multiple attemps- a full bulk box of 40 these for $200 -or was it euros, I forget, it might have been 200€ actually- through an auction with only one bid; which is quite a sum of money for obscure tubes of an obscure tube type imo... Even for 40 of them (+20 + 30€ of shipping).


----------



## inphu510n

We'll see if I make it on the 100th page here...
   
  I got the 6AU6 to 6AK5 converters in the mail today and I can confidently say that they work!!
  They fixed the issue and got it right. Yay!
  Now I can test out these 6485's that everyone is raving about.
  Man it's nice to hear the sheer clarity of the Tek tubes again. These things are almost spooky sometimes.


----------



## Acapella11

Quote: 





inphu510n said:


> We'll see if I make it on the 100th page here...
> 
> I got the 6AU6 to 6AK5 converters in the mail today and I can confidently say that they work!!
> They fixed the issue and got it right. Yay!
> ...


 
   
  Hi inphu510n, Which version of the adapter have you received?


----------



## inphu510n

acapella11 said:


> Hi inphu510n, Which version of the adapter have you received?




 I'm not sure because there's no documentation or anything that comes with these. My assumption is that they're the "A" version.
Notably, they have a more professional looking sticker on them now rather than the hand written one as before.


----------



## MIKELAP

Got the socket today they work great they are the Ä¨ version  for you littledot MKIV owners if your wondering what his the exterior diametre of the sockets well first of all they are  not round but the biggest diametre is .765 thousands which is 49/64¨of an inch  or 1/64 bigger than 3/4 of an inch.   In millimeters that would be 19.447 m.m. so the socket being oval is probably because they are 2 piece shrink wrapped  together .so a good clearance would be required for the tube and the socket to clear the protective cage


----------



## zedmeco

I got my second adapters as well, these were the "A" type, I have two pairs of the ts6485, one pair that i abused a bit trying to solder wire on to and another unused pair. I tried them both with this adapter and did get sound but both pairs are giving me noise, am I really that unlucky? still waiting for the adapters that have all the pins connected and 2/7 linked by wire. hopefully this version will work form. 
  I have ordered these two tube:
  http://www.ebay.co.uk/itm/181150393451?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649
  and
  http://www.ebay.co.uk/itm/330721493306?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649
   
  with the latter, do I use the adapter or are they just plug and play using the ef95 setting?
  thanks 
  z


----------



## Acapella11

Quote: 





zedmeco said:


> http://www.ebay.co.uk/itm/330721493306?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649
> 
> with the latter, do I use the adapter or are they just plug and play using the ef95 setting?
> thanks
> z


 
   
  EF95 plug and play. You can try EF91/92 as well.


----------



## mordy

Tube rolling scare:
   
  Was going through my lot of 22 6AU6 tubes and decided to try a RCA pair. The pins on one tube were slightly bent and I took a needle nose pliers and carefully bent back a couple of pins. Stuck the tubes in - one channel is dead. Moved around the tube a little in the socket - nothing.
   
  When I pulled out the dead tube I noticed that one pin was missing! It had snapped right at the glass! What if I can't get hold of the missing piece? Luckily it broke off in the 2 position with the 2-7 strap in place and a little piece was sticking up, about one mm. I gingerly pulled out the pin with the needle nose pliers- whew!
   
  This is the first time a pin snapped on me. Wonder if anybody else had such an experience? What are you supposed to do if you cannot get the pin out? Push down the piece into the innards of the amp with a paper clip? Can you open up the amp and pull it out from underneath?
   
  Hope that it doesn't happen again.....Maybe I shouldn't mess with with bent pins, but I did straighten out several pins in the past without problems.
   
  Waiting to hear the collective advice.


----------



## inphu510n

Quote: 





mordy said:


> Tube rolling scare:
> 
> Was going through my lot of 22 6AU6 tubes and decided to try a RCA pair. The pins on one tube were slightly bent and I took a needle nose pliers and carefully bent back a couple of pins. Stuck the tubes in - one channel is dead. Moved around the tube a little in the socket - nothing.
> 
> ...


 
  Yikes!
  As far as I know if you were to push the bent pins further into the socket you'd never get them out. Aside from being soldered down to a PCB the underside of the socket isn't open; they look like this.
   
  I've definitely not had pins break on me yet. I'd hope their mostly steel composition would render them a bit more malleable than that. Maybe that was just an unlucky tube where the pins had been bent around too much already?


----------



## Nic Rhodes

This is why I use pin straighteners rather than pliers (and probably why pin straighteners exist). I use a soft plastic RCA one to get them in the right ball park, then use the high tollerance metal ones which are actually so close they remover any corrosion / debris from the pins quite effectively. They are effective and although I haven't bought one in years I suspect they pop up regularly on ebay. [I even have the opposite for straightening sockets!!]


----------



## zedmeco

I got the ek90 6be6 today, plugged them in to find they both hum, I put in the second pair but they hum too. i have a little dot mk3 first edition. Am I really that unlucky? my only hope for these new tube types is the Sylvania GB 6136 6AU6 Gold Pin I have yet to receive. When I read about all your collective experiences with these new types of tubes, I really want to get in on the action, we all want the best sound we can get but so far I have not found anything that sounds acceptable never mind outshining any of the ef95 tubes i have. Am I doing something wrong? Is my amp different from all of your amps? I have bought two pairs of the Tung Sol 6au6 and two pairs of the Siemans 6be6 as well as the socket converters and the sylvania 6au6 gold pin so I am into this for over £100 now but to no joyful aural experience.  Any advice or comments would be gratefully received as right now I am really disappointed.


----------



## gibosi

Quote: 





zedmeco said:


> I got the ek90 6be6 today, plugged them in to find they both hum, I put in the second pair but they hum too. i have a little dot mk3 first edition. Am I really that unlucky? my only hope for these new tube types is the Sylvania GB 6136 6AU6 Gold Pin I have yet to receive. When I read about all your collective experiences with these new types of tubes, I really want to get in on the action, we all want the best sound we can get but so far I have not found anything that sounds acceptable never mind outshining any of the ef95 tubes i have. Am I doing something wrong? Is my amp different from all of your amps? I have bought two pairs of the Tung Sol 6au6 and two pairs of the Siemans 6be6 as well as the socket converters and the sylvania 6au6 gold pin so I am into this for over £100 now but to no joyful aural experience.  Any advice or comments would be gratefully received as right now I am really disappointed.


 
   
  In my experience, it is not uncommon for tubes to hum when you first put them in, but most of the time, they settle down after burning in. You are not using the socket converters with the EK90, right? So that would eliminate the socket converters as the problem.... Put in a pair of your EK90 and burn them in for 20 hours or so, to see if they will quiet down. Good luck!


----------



## MIKELAP

Quote: 





zedmeco said:


> I got the ek90 6be6 today, plugged them in to find they both hum, I put in the second pair but they hum too. i have a little dot mk3 first edition. Am I really that unlucky? my only hope for these new tube types is the Sylvania GB 6136 6AU6 Gold Pin I have yet to receive. When I read about all your collective experiences with these new types of tubes, I really want to get in on the action, we all want the best sound we can get but so far I have not found anything that sounds acceptable never mind outshining any of the ef95 tubes i have. Am I doing something wrong? Is my amp different from all of your amps? I have bought two pairs of the Tung Sol 6au6 and two pairs of the Siemans 6be6 as well as the socket converters and the sylvania 6au6 gold pin so I am into this for over £100 now but to no joyful aural experience.  Any advice or comments would be gratefully received as right now I am really disappointed.


 
  You say you have a first generation mk3 the v1.0 version could that be the reason compare to others who maybe have the v2.0 is that possible !


----------



## inphu510n

mikelap said:


> You say you have a first generation mk3 the v1.0 version could that be the reason compare to others who maybe have the v2.0 is that possible !




From what I've read here this is the most likely reason.
I have a MKII v2.0 and haven't had any issues with rolling except for the recent trials of double diode triode tubes (6AV6). Those tube types produced a buzzing/clicking noise in my amp. Fortunately they were not the best tubes.

Have you tried the 2+7 pin strap using a bit of wire?


----------



## mab1376

Quote: 





gibosi said:


> In my experience, it is not uncommon for tubes to hum when you first put them in, but most of the time, they settle down after burning in. You are not using the socket converters with the EK90, right? So that would eliminate the socket converters as the problem.... Put in a pair of your EK90 and burn them in for 20 hours or so, to see if they will quiet down. Good luck!


 
   
  I always clean the pins before installing with Deoxit.
   
  I really good way to get almost all corrosion off is to spray a sponge with it and shove the pins into the sponge to let it soak for a minute or so, then take it in and out a few times to wipe it clean and tada clean pins.
   
  I've heard some strange noises from corrosion before so i never skip this step anymore.


----------



## inphu510n

Quote: 





mab1376 said:


> I always clean the pins before installing with Deoxit.
> 
> I really good way to get almost all corrosion off is to spray a sponge with it and shove the pins into the sponge to let it soak for a minute or so, then take it in and out a few times to wipe it clean and tada clean pins.
> 
> I've heard some strange noises from corrosion before so i never skip this step anymore.


 
  I've found that Deoxit helps prevent but as far as removing corrosion, I use the backside of an Exacto knife to scrape the pins shiny clean.


----------



## Acapella11

Quote: 





zedmeco said:


> I got the ek90 6be6 today, plugged them in to find they both hum, I put in the second pair but they hum too. i have a little dot mk3 first edition. Am I really that unlucky? my only hope for these new tube types is the Sylvania GB 6136 6AU6 Gold Pin I have yet to receive. When I read about all your collective experiences with these new types of tubes, I really want to get in on the action, we all want the best sound we can get but so far I have not found anything that sounds acceptable never mind outshining any of the ef95 tubes i have. Am I doing something wrong? Is my amp different from all of your amps? I have bought two pairs of the Tung Sol 6au6 and two pairs of the Siemans 6be6 as well as the socket converters and the sylvania 6au6 gold pin so I am into this for over £100 now but to no joyful aural experience.  Any advice or comments would be gratefully received as right now I am really disappointed.


 

 Hi zedmeco, That is indeed very disappointing. Make sure your jumpers sit right and your pins are clean and burn them in as Gibosi suggested. I am not using a V1.0 LD MKIII, maybe that makes a difference.
   
  I received the Siemens EK90 (6BE6 type) tubes today and I am burning them in as we speak. So far, I am quite impressed - _very_ transparent and detailed with great imaging, a bit brighter than the TS 6BE6, which could be a positive feature for some. Final conclusions will have to wait until they are fully burned in and this has to wait a little as I have probably the next two weeks not much time for tubes. Actually, I would like to add that the QED Reference Audio 1 cable I use is quite a nice one for the LD as it sounds very three dimensional and transparent (punchy bass, extended treble as well).


----------



## mab1376

If i remember the v1 can take 408A tubes which is the 20v version of the 6AK5, might have something to do with it.


----------



## MIKELAP

Looks like we can use the new socket for all the EF 92 family tubes but could the sockets be used also for the EF 91 family tubes.ex: Mullard M8083/ CV4014 this is ending up being a great investment i hate changing those jumpers.


----------



## gibosi

Quote: 





mikelap said:


> Looks like we can use the new socket for all the EF 92 family tubes but could the sockets be used also for the EF 91 family tubes.ex: Mullard M8083/ CV4014 this is ending up being a great investment i hate changing those jumpers.


 
   
  Are you asking about the sockets that allow you to use 6AU6 and 6485 tubes? If so, these sockets connect pins 2 and 7, and if used with EF91 and EF92 tubes, they would connect grid #2 to the cathode, which is acceptable. However, it may well be that they will sound different....
   
  I believe that some members of this forum are working with the socket vendor to obtain a socket which will connect pins 5 and 7, which is what the jumpers do. If so, these might be better for EF91 and EF92 tubes, and they would also allow you to use triodes.


----------



## MIKELAP

Quote: 





gibosi said:


> Are you asking about the sockets that allow you to use 6AU6 and 6485 tubes? If so, these sockets connect pins 2 and 7, and if used with EF91 and EF92 tubes, they would connect grid #2 to the cathode, which is acceptable. However, it may well be that they will sound different....
> 
> I believe that some members of this forum are working with the socket vendor to obtain a socket which will connect pins 5 and 7, which is what the jumpers do. If so, these might be better for EF91 and EF92 tubes, and they would also allow you to use triodes.


 
  Yes, wow thats great because i find they sound good as it is but better is always better keep us posted thanks .


----------



## gibosi

Quote: 





mab1376 said:


> If i remember the v1 can take 408A tubes which is the 20v version of the 6AK5, might have something to do with it.


 
   
  I know that the LD 1+ can use 408A tubes, but I don't think it is possible to use these tubes with any LD III or LD IV.....


----------



## mab1376

I can see on some old reviews that people we're using 408A tubes
   
  http://www.head-fi.org/t/266751/review-of-little-dot-mkivse
   
   
  Quote: 





> UPDATE 6 DAYS LATER...
> 
> Well, the MKIVse is turning out to be a far better unit than I could ever hope for. Everything seems past any kind of break-in period and I have about 300 hours on it. Last week, I ordered a setup of tubes (Phillips Jan 5687WB) to take the place of the Mullards. I JUST CAN'T BELIEVE WHAT I'M HEARING! These tubes sound better right out of the box than the Mullards did after 200 hours break-in. I ran them for @ 50hours and they improved even more. I turned right around and ordered another set for spares! So completely High-Fidelity these new tubes are, I'm done tube rolling power tubes from now on. I have some GE 408A's, WE 408A's and Sylvania 408A's coming, so it will only be driver tube rolling from now on. I have never heard a tube like those Phillips 5687WB's before! They are top dog on my list now! Extremely Highly Recommended even at the higher cost.


 
   
   
  Quote: 





> Driver Tubes
> 408A W Elect = Best definition and punch through out. Very full spectrum
> 408A G Elect = Less over all definition, punch still on bass end of spectrum
> 408A Sylvania = Almost identical to G Elect
> 408A G Elect 5 star = Almost identical to W Elect, slight improvement in vocals


 
   
  All for an MK IV review


----------



## john57

Still do not understand how you can use a tube with a 20v heater requirement in equipment that has 6.3v for the heaters.


----------



## mab1376

that's what I'm saying...
   
  Old versions had slightly different specs.


----------



## gibosi

Quote: 





john57 said:


> Still do not understand how you can use a tube with a 20v heater requirement in equipment that has 6.3v for the heaters.


 
   
  Mab1376, thanks for posting this. It was news to me!
   
  This review is from November, 2007. At that time, it was possible to run 408A tubes in the LD IVse. Moreover, it was also possible to use E182CC power tubes. Today, only the LD 1+ can run 408A tubes. This amp has a jumper to switch between 20v and 6.3v. And if anyone is interested in purchasing some 408As, I have a bunch of them.


----------



## hypnos1

Quote: 





acapella11 said:


> Hi zedmeco, That is indeed very disappointing. Make sure your jumpers sit right and your pins are clean and burn them in as Gibosi suggested. I am not using a V1.0 LD MKIII, maybe that makes a difference.
> 
> I received the Siemens EK90 (6BE6 type) tubes today and I am burning them in as we speak. So far, I am quite impressed - _very_ transparent and detailed with great imaging, a bit brighter than the TS 6BE6, which could be a positive feature for some. Final conclusions will have to wait until they are fully burned in and this has to wait a little as I have probably the next two weeks not much time for tubes. Actually, I would like to add that the QED Reference Audio 1 cable I use is quite a nice one for the LD as it sounds very three dimensional and transparent (punchy bass, extended treble as well).


 
   
  Hi A11,
   
  Glad your initial impressions of the Siemens are favourable - I found the real magic appeared at about 30hrs burn-in. A (nice) little extra came when I finally placed the oak 'cones' under my Audiolab and LD, and (don't laugh!) replaced all relevant power lead fuses with some fancy AMR ones, which seemed a reasonable price compared to most others...
  Result - even more clarity, detail, 'space' and the (not very technical?) word - clean...And I'm fairly sure it wasn't placebo effect!
   
  Look forward to your later findings...


----------



## Acapella11

Quote: 





hypnos1 said:


> Hi A11,
> 
> Glad your initial impressions of the Siemens are favourable - I found the real magic appeared at about 30hrs burn-in. A (nice) little extra came when I finally placed the oak 'cones' under my Audiolab and LD, and (don't laugh!) replaced all relevant power lead fuses with some fancy AMR ones, which seemed a reasonable price compared to most others...
> Result - even more clarity, detail, 'space' and the (not very technical?) word - clean...And I'm fairly sure it wasn't placebo effect!
> ...


 
  
 Hey hypnos1, so you also got an M-DAC? =) What filter are you usually using? With what kind of cable do you connect them? I am absolutely not laughing. Thanks for the tip. Might be that I do that as well at one point. I was totally not into cables until later, I realized their meaning.
 After further listening, and 24 h burn in (EF95), the EK90 still sounds brighter, opener, "sparklier" than the TS 6BE6, which sounds politer and gentler. The EK90 stays "clean" and does not distort. The "more" in space you hear is probably from the brighter presentation, which transports more space information and makes the tube sound wetter as well. I really look forward to compare this tube with the Amperex 6BY6 and, taking the EK90 as a good example, there might be some more gems hidden in heptode land.


----------



## MIKELAP

uote: 





acapella11 said:


> Hey hypnos1, so you also got an M-DAC? =) What filter are you usually using? With what kind of cable do you connect them? I am absolutely not laughing. Thanks for the tip. Might be that I do that as well at one point. I was totally not into cables until later, I realized their meaning.
> After further listening, and 24 h burn in (EF95), the EK90 still sounds brighter, opener, "sparklier" than the TS 6BE6, which sounds politer and gentler. The EK90 stays "clean" and does not distort. The "more" in space you hear is probably from the brighter presentation, which transports more space information and makes the tube sound wetter as well. I really look forward to compare this tube with the Amperex 6BY6 and, taking the EK90 as a good example, there might be some more gems hidden in heptode land. 
  Hey guys be careful about that cable talk on here dont want to have to bring in an exorcist. And by the way just ordered a 4 foot Cardas cable for my hd800 other ones were to long


----------



## Acapella11

Quote: 





mikelap said:


> Hey guys be careful about that cable talk on here dont want to have to bring in an exorcist. And by the way just ordered a 4 foot Cardas cable for my hd800 other ones were to long


 

 Lol, OK, get them in =)
   
  For copper cables in different qualities (including UP-OCC), lengths and suitable for different headphones or RCA/XLR-cables, you could also check out http://www.charlestoncablecompany.com/ if you need any more.
   
  Congrats to the Cardas cables


----------



## Audiofanboy

Still working on finding the best double-diode triodes. I got some Telefunken 6AV6/EBC91 in the mail a few days ago, and proceeded to test them. Strangely enough, these sound quite close to the Lorenz EBC91 I reviewed, which the same airiness and sultriness I found in the Lorenz. German sound? I don't know about that... But even if I had been looking for that "trait", I can't deny that they sound close in terms of objective qualities. Anyway, very nice tubes, I'd hate to have to pick a fav' between the Tele and the Lorenz!
   
  As per usual, here's a few pics of those last two tube types I got. I changed methods to take those pictures, so no more pictures of tubes on my window sill lol.
   
  First, the Telefunken, both with the "diamond" on the base, date coded in the 70s and made in the -genuine Tele- Ulm factory. Strictly identical but slightly different markings though same logo, I think they were made a few years apart too, but they sound and look exactly the same anyway, so who cares?
   

   
  The Tele boxes, again, strictly identical.
   

   
  The Lorenz EBC91 I was talking about last week. These are very well built as well, with a side mounted D-getter and side flash; notice how solid and clean the internals look. No idea about dates, I'd say 50s, but I haven't found information on Lorenz date codes yet.
   

   

   
  I'll probably be putting up an ad in the trade section pretty soon -when I have both the time and motivation to- with a whole bunch of tubes for sale; basically many tube types I had bought in double, triple, or unreasonable amounts in hopes of finding the best. Stuff like CV4015, 4 or 5 different types of CV4014 and CV131, two types of Mullard CV850, a pair or two of Mullard EF94, a couple Voshods 6zh1p-ev, some American pentodes (GE 6485, 8136, 6CB6A...) and the probably even more I've accumulated. Anyone interested by anything in particular before I start takings pics to actually make the ad?


----------



## hypnos1

Quote:


acapella11 said:


> Hey hypnos1, so you also got an M-DAC? =) What filter are you usually using? With what kind of cable do you connect them? I am absolutely not laughing. Thanks for the tip. Might be that I do that as well at one point. I was totally not into cables until later, I realized their meaning.
> After further listening, and 24 h burn in (EF95), the EK90 still sounds brighter, opener, "sparklier" than the TS 6BE6, which sounds politer and gentler. The EK90 stays "clean" and does not distort. The "more" in space you hear is probably from the brighter presentation, which transports more space information and makes the tube sound wetter as well. I really look forward to compare this tube with the Amperex 6BY6 and, taking the EK90 as a good example, there might be some more gems hidden in heptode land. 
   
  Hi A11,
  I get what you explained re the effects of a brighter presentation - the HD650s  seem to like this quality. I certainly do! Something else I seemed to notice after my 'tweaking' - shortcomings in a recording revealed themselves more...previously, with tracks that I thought were ALL equal, suddenly some are 'more equal than others', to paraphrase George Orwell!!
   
  Have got the Audiolab 8200cd on Optimal Transient XD, which seems to be the flavour of choice. To be honest I haven't done much comparing...
   
  Now then, re cables.. boy, you've got me going. (Sorry mikelap, you'll have to divert your eyes!). But I'll try to be brief...
  I know so much nonsense surrounds this subject, but I do believe we need to try and find some mid-ground between nonsensical and stock. Before I knew better, I splashed out on some pure silver interconnects from Artisan Silver - thankfully at a sale price. And lovely they are too.(Bought mainly because of the sound that came from my speakers  after being able to get some pure silver  cables off ebay, for a steal). Then I discovered someone selling 8-stranded pure silver braided cable (a la Kimber, but much cheaper), and decided to make up my own headphone cable, using (Cardas equivalent, but cheaper once again) silver- plated RCAs. I just LOVE silver! And am so happy with the result...
  As for mains leads, I found some nice ones from mains-cables-r-us - own make; nice German Lapp cable; silver-plated wattgate/MK plugs - at a far more reasonable price than Russ Andrews' offerings. Did I mention the (older style) Tacima mains conditioner/filter?....
  OK , OK -  enough already.
  My main point being actually that the results we get from our different tubes are surely inextricably linked with all the numerous elements  in the chain, from mains outlet to the wire in our headphones - so many variables!!
   
  Edit. Notice the deliberate mistake?... Silly me - RCAs on headphone cable? Got meself mixed up with the other interconnect I made. Of course I should have said Neutrik plug!...


----------



## MIKELAP

Quote: 





hypnos1 said:


> Hi A11,
> I get what you explained re the effects of a brighter presentation - the HD650s  seem to like this quality. I certainly do! Something else I seemed to notice after my 'tweaking' - shortcomings in a recording revealed themselves more...previously, with tracks that I thought were ALL equal, suddenly some are 'more equal than others', to paraphrase George Orwell!!
> 
> Have got the Audiolab 8200cd on Optimal Transient XD, which seems to be the flavour of choice. To be honest I haven't done much comparing...
> ...


 
   
  Couldnt waist a good picture i had lying around . But anyways   REPENT !!!!!


----------



## MIKELAP

Regarding cables as you might off guested i was just fooling around a tiny bit with my last post all in good fun i must add but i can remember in the 70's when i got my first good sound system speaker cables were making there appearance or starting to be more popular so i had heard and decide to buy some instead of using the traditionnal lamp wire  i dont remember the brand but it was a well known company well i must say that as soon as i put a record on turn the pot or smoke it not what came first there was a difference mostly if i remember correctly in the bass department there was a better bass because of the new cable i was happy because the ultimate goal is always to get the best sound possible and thats where my next picture comes in .


----------



## gibosi

*Sometimes things are not what they seem....*
   
  I too received some Telefunken 6AV6 in nice Telefunken boxes. However, my tubes do not have the diamond on the base. Worse, they are not even made by Telefunken, but by Mazda France. In fact, they are identical to the Philips 6AV6 Audiofanboy and I received recently. And as you might recall, he was not impressed with these tubes (See his post 1489, page 100).
   

   
  I also received some Amperex/Bugle Boy 6AV6. However, imagine my surprise when I discovered that these are simply rebranded RCA black plate 6AV6!!
   

   
  So... in the European 6AV6 world, tubes are often not what they seem....
   
  Be careful out there! lol


----------



## zedmeco

does this mean I can't play any more? does anyone else have the lowly mk3 v1.0?


----------



## gibosi

Quote: 





zedmeco said:


> does this mean I can't play any more? does anyone else have the lowly mk3 v1.0?


 
   
  My opinion.... If you can successfully use EF91, EF92 and EF95 tubes, I can see no reason why you cannot also use these new tubes. Have you burned your new tubes in for 20 hours? Again, until you have done this, it is too soon to draw any conclusions...


----------



## Audiofanboy

If you can use the regular 6.3V driver tubes, there is _no_ reason you shouldn't be able to use all the tubes that have been rolled here.
   
  If I recall, you shouldn't use 6N30P _power_ tubes on the MK III v1 though. But all those new drivers tube shouldn't be any more risky then stock 6AK5 or the -actually very high gain- EF91 type.


----------



## MIKELAP

Quote: 





zedmeco said:


> I got the ek90 6be6 today, plugged them in to find they both hum, I put in the second pair but they hum too. i have a little dot mk3 first edition. Am I really that unlucky? my only hope for these new tube types is the Sylvania GB 6136 6AU6 Gold Pin I have yet to receive. When I read about all your collective experiences with these new types of tubes, I really want to get in on the action, we all want the best sound we can get but so far I have not found anything that sounds acceptable never mind outshining any of the ef95 tubes i have. Am I doing something wrong? Is my amp different from all of your amps? I have bought two pairs of the Tung Sol 6au6 and two pairs of the Siemans 6be6 as well as the socket converters and the sylvania 6au6 gold pin so I am into this for over £100 now but to no joyful aural experience.  Any advice or comments would be gratefully received as right now I am really disappointed.


 
  One thing i noticed once about my mk3 i had that hum once it could be interference from something next to it maybe cordless phone to close to pc try that who knows i removed my phone come to think of it no more hum nothing to loose


----------



## mab1376

Quote: 





audiofanboy said:


> If you can use the regular 6.3V driver tubes, there is _no_ reason you shouldn't be able to use all the tubes that have been rolled here.


 
   
  Makes sense to me. I would give it a shot.


----------



## mordy

"If everything else fails, read the instructions:" From the Little Dot MKIII manual p 3:
   
   
  " Static/Noise in one or both channels: Try cleaning the tube pins to free them of oxidation. Also check
 for sources of interference nearby such as _wireless routers, telephone base stations, and other RF
 emitting devices. _Check the fuse and re-seat it so that it makes good electrical contact. Move all
 switches back and forth several times to “loosen” them, and then set them securely into position. "
   
  "Ground Loops: In systems where the components have multiple paths to ground, you may notice a 60
 Hz hum on the Little Dot output. Please only use a cheater plug power-cord as the last resort, as this
 can be a safety hazard. To resolve ground loop issues, the better method would be to use a ground
 loop isolator. The ideal method would be to solve the ground loop at its source by connecting all
 components to common ground and/or have your electrical wiring checked by a professional electrician."
   
  Here is a link to the manual. Most of the recent questions posed about tube compatibility etc are answered here:
   
   
  http://fl210.blog.163.com/blog/static/5666792220109314356477/


----------



## gibosi

Quote: 





zedmeco said:


> I got the ek90 6be6 today, plugged them in to find they both hum, I put in the second pair but they hum too. i have a little dot mk3 first edition. Am I really that unlucky? my only hope for these new tube types is the Sylvania GB 6136 6AU6 Gold Pin I have yet to receive. When I read about all your collective experiences with these new types of tubes, I really want to get in on the action, we all want the best sound we can get *but so far I have not found anything that sounds acceptable never mind outshining any of the ef95 tubes i have.* Am I doing something wrong? Is my amp different from all of your amps? I have bought two pairs of the Tung Sol 6au6 and two pairs of the Siemans 6be6 as well as the socket converters and the sylvania 6au6 gold pin so I am into this for over £100 now but to no joyful aural experience.  Any advice or comments would be gratefully received as right now I am really disappointed.


 
   
  (*Bold* in the above quote added by me...)  *zedmeco* has absolutely no problems with humming or any other noises when using his current EF95 tubes. He is experiencing problems only with these new tubes. And therefore, I still believe that these tubes just need to be thoroughly burned in. And while there are no guarantees, it is very likely that they will quiet down in time.


----------



## hypnos1

Quote: 





mikelap said:


> Couldnt waist a good picture i had lying around . But anyways   REPENT !!!!!


 
   
  Hey mikelap, I love Anthony Hopkins ALMOST as much as silver!!...Go on - gi' us a kiss!!!
   
  Bell wire rules, OK...(smile).
   
  Anyway, keep on truckin' there boy.
  BFN


----------



## gibosi

Recently, I received a couple of small packages and as a result I have returned to Heptode land. 
   
  A pair of Tung Sol 6BE6. Does anyone have a pair with O-getters?
   

   
  A pair of Telefunken EK90.
   

   
  A pair of Siemens EK90. I noticed that some have received Siemens EK90 in white boxes with black lettering. Mine came in the traditional orange and blue boxes. I wonder if there are any differences?
   

   
  And a pair of Brimar CV4012
   

   
  Currently, the Telefunkens are burning in....


----------



## mab1376

I just popped in my  Telefunken EK90 and immediately it reminds me the of the TS 6AH6, overall awesome. very balanced with a good bass kick, highs are clear and mids.
   
  My initial impression is this is that these are end-all/be-all tubes, very impressed.
   
  I ordered them from NOStubetore.com and they look100% new which i can't say for the EH900S
   
  My pre burn in test track is 'Ween - Stay Forever'
   
  I also received my Telefunken EH900S which i will try when I'm  feeling ambitious.


----------



## hypnos1

Quote: 





mab1376 said:


> I just popped in my  Telefunken EK90 and immediately it reminds me the of the TS 6AH6, overall awesome. very balanced with a good bass kick, highs are clear and mids.
> 
> My initial impression is this is that these are end-all/be-all tubes, very impressed.
> 
> ...


 
   
  Hi mab.
   
  My Siemens EK90s just keep getting better - I'm sure your Telefunkens will blow you away!..Hope so...
  Will have to give them a try and see how they compare Can't see how anything can better these EK90s - certainly on a simple ef 95 setting. But I'm forgetting the amazing Audiofanboy!!...
  I fear you will now be disappointed with the EH900Ss, though...
  Happy listening!


----------



## MIKELAP

Found a bunch of $2.00 tubes G.E.6136 ,and C.V.850, also HIT RAY 6AV6 that im planning an intervention on but those arent $2.00 of course so just want to make shure im cutting the wright pins so i took a picture of my tube with the pins im suppose to cut at 5 and 6 o'clock shown by arrows you cant see very much and the other picture i found . looks like the right ones.if its the right picture


----------



## gibosi

Quote: 





mikelap said:


> Found a bunch of $2.00 tubes G.E.6136 ,and C.V.850, also HIT RAY 6AV6 that im planning an intervention on but those arent $2.00 of course so just want to make shure im cutting the wright pins so i took a picture of my tube with the pins im suppose to cut at 5 and 6 o'clock shown by arrows you cant see very much and the other picture i found . looks like the right ones.if its the right picture


 
   
  Yes, the arrows on your picture are pointing to the correct pins, 5 and 6. And the second picture is one of my tubes. So just cut those pins, set your LD for EF92 tubes, and you are good to go.
   
  A HIT RAY tube? I believe these are Japanese tubes.... I had never heard of them until now. Please let us know how they sound.


----------



## MIKELAP

Quote: 





gibosi said:


> Yes, the arrows on your picture are pointing to the correct pins, 5 and 6. And the second picture is one of my tubes. So just cut those pins, set your LD for EF92 tubes, and you are good to go.
> 
> A HIT RAY tube? I believe these are Japanese tubes.... I had never heard of them until now. Please let us know how they sound.


 
  Thanks gibosi for the great picture dont have those cutters dough . do you think a dremel has to much vibrations while cutting and yes they are japanese tubes . i heard somebody was working on having other sockets made they wouldnt be to go from ef 95 to ef 92 if that possible at all maybe you talked to me about this i dont remember who did. Thanks again .


----------



## MIKELAP

Got those yesterday not the greatest sounding compared to the 6au6 but  still decent looks like  they are english with  broad arrow ,collecting ww2 stuff thats why i figure they are english could that be 1969 anybody have more infos on these . Thanks


----------



## gibosi

Quote: 





mikelap said:


> Thanks gibosi for the great picture dont have those cutters dough . do you think a dremel has to much vibrations while cutting and yes they are japanese tubes . i heard somebody was working on having other sockets made they wouldnt be to go from ef 95 to ef 92 if that possible at all maybe you talked to me about this i dont remember who did. Thanks again .


 
   
  If you have a very steady hand, I am sure a Dremel will work fine. However, I found it difficult to keep the cutting wheel away from neighboring pins, as you can see in this picture. Also, if you try to cut the pins off very close to the glass, and the cutting wheel touches the glass, the tube will likely be destroyed. If you can find a pair of flush cutters, it is much easier (and safer for the tube). 
   

   
  I too remember that someone mentioned working with the Chinese socket converter vendor to obtain a 5 to 7 converter to allow the use of EF92 tubes without having to change jumpers, but I don't know anymore than that.....


----------



## gibosi

Quote: 





mikelap said:


> Got those yesterday not the greatest sounding compared to the 6au6 but  still decent looks like  they are english with  broad arrow ,collecting ww2 stuff thats why i figure they are english could that be 1969 anybody have more infos on these . Thanks


 
   
  These appear to be the British military version of the 6AK5W / 5654:
   
  http://www.radiomuseum.org/tubes/tube_cv850.html
   
  The M8100 / CV4010 is the newer version of this tube.
   
  And yes, it appears that they were manufactured in 1969, the 10th week.


----------



## mordy

Hi Mikelap,
   
  Instead of the Dremel, just use a small cutting pliers - does not have to be the flush cutting kind. If you end up with a little piece sticking out, try to trim it with the cutting pliers. You will be left with a very small piece sticking out. Just take a little electric tape and cover it, or two layers if the piece is still sticking out too much.Works just fine.


----------



## zedmeco

my sylvania GB6136 (6AU6) with gold pins arrived today, using the "a" type converted I plugged them into my amp, and they sound fantastic!!!! no noise at all, though they do look a bit wired in the amp
  .


----------



## gibosi

Great news! I was pretty sure your amp could easily handle these new tubes. You just needed to get a good pair.
   
  Interestingly, my pair of Sylvania GB6136 with gold pins were pretty noisy when I first plugged them in.  Very disappointing.... But after being burned in, they are now completely quiet.
   
  Enjoy!


----------



## mab1376

I am absolutely in love with my Telefunken 6BE6 using with standard EF95 settings.
  I emailed NOSTUBESTORE about getting some Siemens 6BE6 to compare... but SOMEONE bought all of them recently according to the owner... 
	

	
	
		
		

		
			




   
  I'm sure I could find a pair somewhere else, just haven't looked yet.
   
  Eventually I'll try out my EH900S with gold pins.


----------



## MIKELAP

Quote: 





mordy said:


> Hi Mikelap,
> 
> Instead of the Dremel, just use a small cutting pliers - does not have to be the flush cutting kind. If you end up with a little piece sticking out, try to trim it with the cutting pliers. You will be left with a very small piece sticking out. Just take a little electric tape and cover it, or two layers if the piece is still sticking out too much.Works just fine.


 
  Thanks mordy thats whats i did finally took the smallest cutters i had and i was left with about 1/16 which i filed off with a small square file i had


----------



## mordy

Sonic bliss?


----------



## MIKELAP

A couple days ago saw my guy at flea market at guess what i bought some tubes some G.E. 6136  ,C.V. 850, and a pair of Hit Ray clear tops Japanese 6AV6  tubes which i am listening to right now my first impressions are that the soundstage is wide theres a good tight bass i find  the treble to be very present i find to be borderline but still very good younger guys might say a bit hot .sound in general is transparent maybe i would be curious to see what those of you who tried the 6av6 tubes  think .


----------



## gibosi

Quote: 





mikelap said:


> ..... a pair of Hit Ray clear tops Japanese 6AV6  tubes which i am listening to right now my first impressions are that the soundstage is wide theres a good tight bass i find  the treble to be very present i find to be borderline but still very good younger guys might say a bit hot .sound in general is transparent maybe i would be curious to see what those of you who tried the 6av6 tubes  think .


 
   
  Welcome to Triode Land! You might be the first to try the Hit Ray 6AV6. I have seen speculation that Hit Ray = Hitachi + Raytheon, but even so, I do not know if anyone here has tried the Raytheon 6AV6 either. It has been my experience that 6AV6 often have a good tight bass and, compared to pentodes, a rather pronounced treble, so I suspect that what you are hearing is pretty typical for this family of tubes. Are you impressed enough to try some more?


----------



## Audiofanboy

I've been running 6AV6 tubes for about a month and can vouch for their qualities, especially in the treble department but not only (realism, soundstage, and bass for at least on pair I own). Treble will most likely get "nicer" after 10-20 hours, like on the "hotter" ones I tested though, so I wouldn't worry.
   
  OK, it's been bugging me to _not know_ why 6BE6 and 6BY6 heptode -or more precisely pentagrid converters- work better with pin 7 -grid 3- left unplugged or open; not that I've tested it myself yet, but it's the theory behind this that bugs me.
   
  Those pentagrid converters have, well, five grids, grid 5 is very simply the same as grid 3 in a pentode, it is just there to catch stray electrons -and send them back to the cathode, to which it is internally connected in this case- so that's easy.
   
  Grid 1 is the oscillator grid, and you've all been using it like the typical signal grid in both pentodes (grid 1) and triode (grid.), and it happens to be made to receive one signal anyway, so that makes sense. Grid 3 is the mixer grid and is apparently made to also receive a signal. Grids 2 and 4, internally connected, act both as the screen grid in a pentode (grid 2) and anode for the oscillator grid (grid 1 in a pentagrid converter/heptode).
   
  I assume the usual purpose of these tubes is to amplify a signal on grid 1, received and "screened" by grid 2 (and 4), "mixed" to the signal on grid 3, and eventually caught by the anode to be useful to _some other electronic section_. Not that any of this matters for our purposes.
   
  Now, it appears that these tubes don't give their best when you tie grids 2+3+4 to the anode, and yet they seem to work the same way as triode-strapped pentodes when you just ignore grid 3 and strap grid 2+4 to the anode -grid 5 being hardwired to the cathode regardless- an use grid 1 to send the audio signal.
   
  Thinking from different sources I've just read, things I'd read about the use of 6AU6 pentodes in microphones -more on that below- and the using the coincidencial discovery above, I'm pretty sure there are alternative ways to plug these tubes, that could work just as well and perhaps better -which would be the obvious goal here.
   
  Apparently, people have been using 6AU6 tubes triode-strapped in funny ways in for microphone buffer/amplification purposes for years. In order to get the lowest noise possible -pretty important when you're recording, say, a voice- they often grounded the anode, and used the grid 2 as the _de facto_ anode; I assume grid 3 was still strapped to the cathode.
   
  On these pentagrid converters, we have a total of five grids -but only three pins- and one anode to play with. So, here are a few ideas that I'd like to test or at least brainstorm, most of which have little reason to explode lol:
   
  - Using grid 2 and 4 as the anode, with both grid 3 and anode left "open" (in theory they should be grounded in this case scenario). So, chopping pin 5 (anode) and running the tube in the EF95 setting basically. Should produce sound, may be good or bad, should not explode.
   
  - Using both grid 1 and grid 3 as for the audio signal. I have no idea is this can work properly since you have grid 2 sandwhiched between them. Basically, it would imply wire-modding pins 1 and 7 together and running the tube on the EF95 setting.
   
  - Using grid 3 _instead_ of grid 1 for the audio signal. Again, may be difficult since grid 2 would be in the way between the cathode and the audio signal. Would mean chopping pin 1 and wire-modding pin 7 to socket hole 1, which in and of itself is complicated. EF95 setting.
   
  - Using grids 2+3+4 as the audio signal grid and leaving grid 1 disconnected. Same issue as above, no idea if it would work well, and same pin mod but EF92 setting.
   
  - Using grids 1 and 3 as the audio signal grid and using grids 2 and 4 as the _de facto_ anode, with official anode disconnected. Again, maybe it would work, maybe not, hard to say. Would mean chopping pin 5 off, and wire-modding pins 1 and 7 together.
   
  Anyway, I need to investigate this some more, but you get the idea, there may be more possibilities to plug heptodes -and I'm starting to understand why they're not meant to have grid 3 connected to grids 2 and 4 and _not_ running a signal (the tube is meant to run _two_ signals).
   
  Some resources, half of which is beyond me:
  https://en.wikipedia.org/wiki/Pentagrid_converter
  http://www.diyaudio.com/forums/tubes-valves/163842-possible-use-pentagrid-tubes.html


----------



## MIKELAP

Quote: 





gibosi said:


> Welcome to Triode Land! You might be the first to try the Hit Ray 6AV6. I have seen speculation that Hit Ray = Hitachi + Raytheon, but even so, I do not know if anyone here has tried the Raytheon 6AV6 either. It has been my experience that 6AV6 often have a good tight bass and, compared to pentodes, a rather pronounced treble, so I suspect that what you are hearing is pretty typical for this family of tubes. Are you impressed enough to try some more?


 
  The impressions i gave you before with regards to the Hit Ray 6AV6,  i was using my Denons d-5000 with my go to track which is Duke Robillard Albie Aint Here now i went with the senns hd800's and man detail i definetily like those tube clean sounding bass very good dont know how they will sound in 20 hours but i like em after 4 or 5 hours i would try other tubes why not


----------



## mab1376

Quote: 





hypnos1 said:


> Hi mab.
> 
> My Siemens EK90s just keep getting better - I'm sure your Telefunkens will blow you away!..Hope so...
> Will have to give them a try and see how they compare Can't see how anything can better these EK90s - certainly on a simple ef 95 setting. But I'm forgetting the amazing Audiofanboy!!...
> ...


 
   
  These Telefunkens are absolutely amazing! Using them with my MK IV SE, PS Audio Digital Link III with some upgraded parts, 6N6P-IR power tubes, and of course my beloved HD650's.
   

   
   
  Someone would have to make a really convincing argument to make me want to try anything else... can this get better?
   
  ...anyway I'm using with a standard EF95 settings, are there any better recommended settings? I see some people recommend snipping some pins? Or is that only for the 6AV6?
   
  Has anyone directly compared them to the EK90/6BE6?


----------



## MIKELAP

Gave a listen to the Tung-Sol 6BE6 on EF92 setting and the Hit Ray 6AV6 and to me the 6AV6 are the clear winner  very wide soundstage with the hd800 starting to like these very much tomorrow might try to compare  them to the 6136 or 6AH6 anybody try this combo yet youll save me a  jumper change for a while. My lack of patience thanks you.


----------



## mab1376

Quote: 





mikelap said:


> Gave a listen to the Tung-Sol 6BE6 on EF92 setting and the Hit Ray 6AV6 and to me the 6AV6 are the clear winner  very wide soundstage with the hd800 starting to like these very much tomorrow might try to compare  them to the 6136 or 6AH6 anybody try this combo yet youll save me a  jumper change for a while. My lack of patience thanks you.


 
   
  Do you prefer the 6BE6 on the EF92 setting as opposed to the EF95 setting?


----------



## Audiofanboy

Those Telefunken tubes do look great, I ought to try some at some point. 
   
  To continue on my technical ramblings -that nobody seems to care about anyway lol- I've found a bit more information that confirms that my reasoning about heptodes isn't totally out there, and that at least a few of my ideas not only work, but have been used in various schematics.
   
  From some random forum post found on google:
   
_"I understand what you are saying, and in fact in researching the ways a heptode can be used, I found several example where it is connected as a triode and one where it is connected as a pentode.
 All in all, since g5 is tied to the cathode internally, and g2 and g4 are also tied together internally, we have the following combinations:
 As pentode G2 + G4 used as screen grid and:
 1. G1 tied to cathode, G3 used as the control grid (*)
 2. G3 tied to cathode, G1 used as the control grid
 3. G1 + G3 tied together used as control grid
 4. G3 tied to plate, G1 used as control grid
 5. G3 tied to G2+G4, G1 used as control grid

 As triode:
 1. G2+G4 and G3 tied to plate, G1 is the control grid
 2. G2+G4 tied to plate, G1 tied to cathode, G3 is the control grid (*)
 3. G2+G4 tied to plate, G3 tied to G1 and used as control grid (*)
 4. G2+G4 and G3 tied together used as control grid, G1 tied to cathode
 5. G2+G4 and G1 tied together used as control grid, G3 tied to cathode
 6. G2+G4, G1 and G3 tied together used as control grid
 7. G1 and G3 tied to cathode, G2+G4 used as control grid

 That makes 5 different pentodes and 7 different triodes  but not all are equally promising. The combinations marked with (*) I have seen in various schematic diagrams.
 In particular, G2+G4 do seem to be the equivalent of a pentode screen grid, so probably pentodes 1-3 and triodes 1-3 are the useful ones._"
   
  So, basically -forgetting about the grounded anode idea for the time being- this guy says that two of my suggestions work.
   
  - Strapping pin 6 to pin 5 (grid 2 and 4 to anode, the amp does on the EF95 setting anyway), chopping pin 1 off and somehow tying it to pin 2 (strapping grid 1 to the cathode, doable but difficult without an adapter) and wire-modding pin 7 to socket hole 1 (using grid 3 as the signal grid). EF95 setting.
   
  - Or -much easier- strapping pin 6 to pin 5 (same as above, basic EF95 setting), and wire-modding pin 7 to pin 1 (tying grids 1 and 3 together).
   
  Now, of these two options, number 2 is the obvious winner. Most of you are already using those heptodes/pentagrid converters with grid 3 (pin 7) floating and have reported that it works better that way. That is probably -as I wrote earlier- because grid 3 is intended, like grid 1, to be a control -signal- grid, and you don't want a signal grid without a signal tied to the anode sandwhiched between two screen grids.
   
  So, instead of just leaving grid 3 floating -which despite everything else, can't be ideal- why not try and strap it with the good ol' wire-mod to pin 1 (with the same EF95 setting)? It makes perfect sense to be using the "signal" grids in a heptode for, well, signal purposes, and tying everything else to the anode.
   
  Anyone feel like trying before I do it?


----------



## mab1376

Maybe i'll try this on my Tung-Sol 6BE6 and see what happens in a day or two when i get some time.
   
  just strap 7-1 right?


----------



## gibosi

European Heptode Shoot Out (EF95)
   
  (I know.. I know... I should do this all over again, strapping pins 1 and 7, but I am too lazy!  Soooo sorry 
   
  Amperex 6687/E91H (6BY6), Brimar CV4012 (6BE6), Siemens EK90 (6BE6) and Telefunken EK90 (6BE6). I purchased the three 6BE6 from the NOStubestore in Turkey and the 6BY6 from an eBay vendor in the states.
   
  First, as a group, none of these tubes bring background sounds too close as is the case with some triodes and a few other heptodes I have heard. Moreover, all of these tubes have the typical "heptode sound" we have come to expect, with a powerful and punchy bass, an extended, but not overly bright treble, a clean and round midrange, and a wide sound stage with excellent imaging. Also interesting, I found this collection of tubes to be a nice example of the so-called "British - Holland - German sound continuum" that goes from warm and comfortable to detailed and airy.
   

   
  First is the British sound, the Brimar CV4012.  As AFB has already noted, this tube has a very thick and heavy bass, and a large and deep soundstage with good instrument separation. Vocals and horns are mellow and warm, with extended, but not overly bright highs. Even though the bass is kind of mushy, I still find these tubes to be very enjoyable and easy to listen to.
   

   
  Next is the Holland sound, the Amperex 6687/E91H. The bass is cleaner and more articulate than the Brimar bass, but still very powerful and punchy. Vocals, piano and horns are still rather warm, but not as warm as the Brimars, and the upper mids and highs are a bit brighter, with a good bit of air and detail. And like the Brimars, these have a very wide and deep soundstage with good instrument separation. I feel these Amperex are a very delicious blend of warmth and detail. In my mind these are "refined" Brimars.
   

   
  Next is the Siemens EK90 version of the German sound. The bass is powerful, punchy and articulate, but it doesn't have quite the weight of the Amperex. Vocals, piano and horns are a bit more forward than the Amperex, airy and detailed. And of course, these have a very wide and deep soundstage with good instrument separation. The Siemens seem to me to be intermediate between the Holland/Amperex sound and the Gerrman/Telefunken sound, the best of both in my mind.
   

   
  And finally, the Telefunken EK90 version of the German sound. The bass is very comparable to the Siemens, but again, it doesn't have quite the weight of the Amperex. Vocals, piano and horns are the most forward of all these tubes with plenty of air and detail, clean and transparent. And as with all of these tubes, the Telefunkens have a very wide and deep soundstage with good instrument separation. In my opinion these are the epitome of the German sound, detailed, airy and clean.




    

  Which is the best? I don't think it is possible for me to say. What I can say is that I believe the Brimar is not quite in the same league as the others. However, I think choosing among the remaining three comes down to which one works best with your sources, your headphones and your preferred sound signature. So I will take the easy way out and recommend that everyone should have all three.


----------



## Audiofanboy

Quote: 





gibosi said:


> European Heptode Shoot Out (EF95)
> 
> (I know.. I know... I should do this all over again, strapping pins 1 and 7, but I am too lazy!  Soooo sorry
> 
> ...


 
   
  Lol, it always makes me laugh when some of my odd formulations end up sticking; this one was meant more as a metaphor, and now it's becoming an actual measuring unit!
   
  Nice work though, gibosi, that's exactly the kind of push and data I needed to go ahead and (re-)try and buy heptodes. That, and what I just tested. Keep reading.
   
  As I wrote a couple of hours ago, strapping grids 1 and 3 in heptodes was apparently not only possible, but made perfect sense. So, I tried it. And guess what, it works -which it should- has more gain -which makes sense- and sounds awesome -which is more interesting!
   
  Basically, it seems that sending the audio signal through _both_ grid 1 and grid 3 adds the effect of the two grids, which is what that kind of tube was made for originally: mixing signals (or something along these lines I believe).
   
  I tested this on what was supposed to be my best heptode out of the ones I had bought a few weeks ago (one pair of Telefunken EH900S in Tele boxes with "Bundeswehr" German military tags and Tele logos and "eagle" on the tubes, which were actually Sylvania 5915; very solid looking though, and still rated for 10K hours as EH900S should be; and two pairs Brimar CV4012, including one which was supposed to be Mullard but wasn't; not the best tubes anyway), so the Tele/vanias 5915/EH900S.
   
  - With grids 2 + 3 + 4 strapped to the anode (basic EF92 setting), they sounded like crap, seriously; all my heptodes did, hence my not using them since then. They sounded dull, flat, boomy... The Brimar were even worse
   
  - With grids 2 + 4  strapped to the anode and grid 3 left floating (basic EF95 setting), they opened up and suddenly sounded like top-tier tubes. Similar in relative sound quality and balance to my best pentodes, but slightly different. Wide and open soundstage, nicely detailed and strong-ish bass -not sub-bass though- and a bit of that pleasing and euphonic low-mids emphasis that many pentodes have, just a little. Anyway, top-tier, musical, and more realistic than my best pentodes (on par with the Tung-Sol 6485).
   
  - With grids 2 + 4 strapped to the anode (EF95 setting) *and* grid 3 strapped to grid 1 (*wire mod from pin 7 to pin 1*, you can't do it wrong, it's the only two pins separated by a gap!), the tubes became different beasts. Basically, they started sounding almost _triode-like_ -never thought I'd end up using that expression to describe tubes- in a good, very good, way. Open, airy, _boundless soundstage_, upper-end detail like you wouldn't believe (and I've been running pure triodes for weeks, so I've gotten pretty picky about upper end detail), and clarity, so much clarity. Voices are just there, thin or thick, husky or mellow; the sound is almost un-tube like in some ways -just like some 6AV6 tubes actually- with none of that mids and low-mids hump or blurry emphasis that, while euphonic, takes away some clarity.
   
  As I said earlier, there is also more gain with that new setting; I'd try it if just for that (gain goes from the equivalent of a 6AK5 to about the same as a 6AU6, so maybe mu = 36~40 instead of 20).
   
  At any rate, I strongly believe you should try this if have a few heptodes lying around, or if you're actually using pentodes; and anyway, once you look at what these tubes were made for and the purpose of each grid, it makes sense. Be warned, the tubes do sound quite different between the two settings, so I'm sure some of you will end up sticking with the former.


----------



## mordy

Hi Gibosi,
   
  My wife asked me last night why I need so many tubes, especially since I do not use a lot of them. After some thought, I came to the conclusion that I have the same question....
   
  (I tried to explain to her that I am looking for the ultimate in sound, but could not come up with a good example that she could relate to. My wife is the kind of person who recognizes her car based on the color, and more than once she tried to open up somebody else's car door because the car had the same color.)
   
  So, here is the question to you: How do the European pentodes compare to the US made Tung Sol 6AH6WA/6485 and the Westinghouse Tektronix 6AU6/4825 tubes? These two tubes are on the top of my list currently, and I am very happy with them.
   
  Would a Siemens EK90 bring more to the table?


----------



## Audiofanboy

Quote: 





mordy said:


> Hi Gibosi,
> 
> My wife asked me last night why I need so many tubes, especially since I do not use a lot of them. After some thought, I came to the conclusion that I have the same question....
> 
> ...


 

 American tubes, especially Tung-Sol tubes, have a _fruitier_ sound than most non-UK European tubes. More oomph and subjective power in the low-mids region among other things, and sometimes slightly rolled-off treble and thicker, rounder bass. GE tubes would also tend to be like this, pretty balanced and mellow but not very airy; Sylvania tubes would be more detailed and airy, and in some ways closer to European non-UK tubes. I haven't owned enough RCA or Raytheon tubes to compare.
   
  I'd still try a heptode or two, if only for the thrill of it. Maybe just wait another couple of weeks for the top-three list to be firmly established, depending on which setting is used.


----------



## gibosi

Quote: 





mordy said:


> So, here is the question to you: How do the European pentodes compare to the US made Tung Sol 6AH6WA/6485 and the Westinghouse Tektronix 6AU6/4825 tubes? These two tubes are on the top of my list currently, and I am very happy with them.
> 
> Would a Siemens EK90 bring more to the table?


 
   
  To follow up on Audiofanboy's comments, I find the Siemens EK90 to be just as good as the TS 6485 and the W 4825, but slightly different, in that the Siemens EK90 seems to have a bit more air and detail. The 6485, 4825 and EK90 are all exceptional tubes and I enjoy all of them. But again, as those of us who have these heptodes will now feel compelled to go back and try them again with pins 1 and 7 strapped, it might be best to watch from the sidelines until the dust finally settles.


----------



## hypnos1

Quote: 





mab1376 said:


> I am absolutely in love with my Telefunken 6BE6 using with standard EF95 settings.
> I emailed NOSTUBESTORE about getting some Siemens 6BE6 to compare... but SOMEONE bought all of them recently according to the owner...
> 
> 
> ...


 
   
  Hi mab,
   
  Oh dear, I sincerely hope all my ravings about the Siemens EK90 haven't encouraged someone to do a spot of profiteering...I am glad however that they are proving to be a popular choice...
  And deservedly so, methinks.
   
  After Genesis/ELO type rock(?), am now seeing what they can do with classical..and WOW - my head is bursting. Piano is awesome; kettle drums astounding; violin 'scratchy' - in the best possible sense ; flute obviously blown; harp so gorgeous I could die; brass nice and raspy (and as for the tuba!...); triangle 'tingly', etc. etc. And all in a wonderfully integrated spatial configuration - even the 'mad' cacophony of Mussorgsky's Great Gate of Kiev (Pictures at an Exhibition - orchestral version). I am now truly in sonic heaven...should I try Audiofanboy's latest finding? Am almost too afraid to do so!...But probably will...


----------



## Audiofanboy

Quote: 





hypnos1 said:


> Hi mab,
> 
> Oh dear, I sincerely hope all my ravings about the Siemens EK90 haven't encouraged someone to do a spot of profiteering...I am glad however that they are proving to be a popular choice...
> And deservedly so, methinks.
> ...


 

 Do it lol! I'm dying to have new and different impressions of all these tubes with that new setting! If only just to compare with what I heard.
   
  Has anyone tried the EH90 (6CS6) type, the third of the 7-pin heptode family? They seem to be easily available.


----------



## mab1376

Quote: 





hypnos1 said:


> Hi mab,
> 
> Oh dear, I sincerely hope all my ravings about the Siemens EK90 haven't encouraged someone to do a spot of profiteering...I am glad however that they are proving to be a popular choice...
> And deservedly so, methinks.
> ...


 
   
  I've emailed about 5 different tube sites and no one has the Siemens in stock. I do have the Telefunken's though, so I don't feel left out lol.
   
  I really like them with very fuzzy rock such as Kyuss and The Black Keys, even though its enjoyable it doesn't do it any justice. to really get a feel for what they're capable of run through the Muse album Resistance. I also really like the Maxence Cyrin Piano cover album with them.
   
  This is also quite and enjoyable track:


----------



## mordy

Tried my 1966 RCA 6BY6  hep tubes with the new 1-7 strap setting. (Used the jumpers I made for the 5-6 setting which fit fine over the gap.) The treble is super detailed and the bass is strong, and the brightness gave way for mellowness. The first thing I noticed was a marked decrease in volume and I had to turn up the volume quite a bit. [If I was using the TS tubes my neighbors would complain with this volume setting.]  The sound was very detailed but lacked sweetness, and after a while I could not listen any more and had to put back the Tung Sol 6AH6WA tubes(I assume that the TS 6485 sound the same although I have not heard them).
   
  Relief. Looks like I prefer the juicy (fruity?) punchy bass and crystal clear presentation. Could be that my system does not like heptodes; maybe it's me.
   
  I do recognize that other people, depending on their equipment and preferences, may like the sound of the heptodes but so far, it's not for me.


----------



## mab1376

The E91H is a special heptode with a passivated third grid designed to reduce secondary emission; this device was used as a "gate", allowing or blocking pulses applied to the first, (control) grid by changing the voltage on the third grid, in early computer circuits (similar in function to the U.S. 6AS6).
   
  http://en.wikipedia.org/wiki/List_of_vacuum_tubes#Special_quality_tubes
   
  E91H Normally replaceable but slightly different than the 6BY6
   
  Basically G3 should always be floated to reduce crosstalk.


----------



## gibosi

Quote: 





mordy said:


> Tried my 1966 RCA 6BY6  hep tubes with the new 1-7 strap setting. (Used the jumpers I made for the 5-6 setting which fit fine over the gap.) The treble is super detailed and the bass is strong, and the brightness gave way for mellowness. The first thing I noticed was a marked decrease in volume and I had to turn up the volume quite a bit. [If I was using the TS tubes my neighbors would complain with this volume setting.]


 
   
  Quote: 





audiofanboy said:


> As I said earlier, there is also more gain with that new setting; I'd try it if just for that (gain goes from the equivalent of a 6AK5 to about the same as a 6AU6, so maybe mu = 36~40 instead of 20).


 
   
  Audiofanboy writes that there should be more gain, not less. And yet, your experience was just the opposite? This is very curious.... Later this evening, I will try out this strapping on one of my heptodes....


----------



## Audiofanboy

Quote: 





mordy said:


> Tried my 1966 RCA 6BY6  hep tubes with the new 1-7 strap setting. (Used the jumpers I made for the 5-6 setting which fit fine over the gap.) The treble is super detailed and the bass is strong, and the brightness gave way for mellowness. The first thing I noticed was a marked decrease in volume and I had to turn up the volume quite a bit. [If I was using the TS tubes my neighbors would complain with this volume setting.]  The sound was very detailed but lacked sweetness, and after a while I could not listen any more and had to put back the Tung Sol 6AH6WA tubes(I assume that the TS 6485 sound the same although I have not heard them).
> 
> Relief. Looks like I prefer the juicy (fruity?) punchy bass and crystal clear presentation. Could be that my system does not like heptodes; maybe it's me.
> 
> I do recognize that other people, depending on their equipment and preferences, may like the sound of the heptodes but so far, it's not for me.


 
   
  Interestingly, while gain seems higher for strong signals -like music- I have noticed that it also seems less linear. Basically, if a signal isn't that strong in the first place, I'll need _a lot_ more volume to actually get more sound, whereas a strong signal will only need about as much volume as a 6AU6 to sound loud. But then again, maybe I also needed a _lot_ more volume on the EF95 setting alone to get more sound, I didn't test it with "weak" signals like the audio from a video; and I confirm I do need less volume for basic music playback.
   
  And like I said, I immediately recognized that the sound is different from both "pentode" sound and heptodes on the EF95 setting, so I'm not surprised that it would not be your fav'.
   
  Quote: 





mab1376 said:


> The E91H is a special heptode with a passivated third grid designed to reduce secondary emission; this device was used as a "gate", allowing or blocking pulses applied to the first, (control) grid by changing the voltage on the third grid, in early computer circuits (similar in function to the U.S. 6AS6).
> 
> http://en.wikipedia.org/wiki/List_of_vacuum_tubes#Special_quality_tubes
> 
> ...


 
   
  From what I've read, there are two kind of heptodes (at least for the ones we use), the ones meant to "mix" or be useful for two separate signals, and the ones meant to "block or let let a signal through" where only one incoming signal is relevant. The E91H seems to be one of the latter, while most 6BE6 seem to be the former; but I still need to look into this some more.
   
  Again, from a theoretical perspective, both floating or strapping grid 3 make sense, and it yields different -good- results, so I'd just try both and use the preferred one.


----------



## MIKELAP

Quote: 





mab1376 said:


> Do you prefer the 6BE6 on the EF92 setting as opposed to the EF95 setting?


 
  Just noticed that they possibly sound better on EF95 (page 77).did not try them on other setting (EF95)yet will leave on EF92 for a a bit .


----------



## Audiofanboy

After spending a bit more time testing my 5915 (6BY6) tubes on both regular "floater" and "strapped" EF95 setting and going back and forth a few times to compare, I can definitely validate my earlier _subjective_ conclusions on sound quality and balance. Both settings yield excellent results, but the "strapped" mode definitely liberates the soundstage and makes it into a seemingly limitless field of sound, whereas the "floater" mode, while quite large, has a more intimate soundstage with instruments very well separated but squeezed closer together.
   
  Floater mode is more immediately pleasing and euphonic, with great detail and realism, excellent separation and nice bass, excellent for casual listening; but strapped mode is a whole step above in terms of detail and the "being there" effect, and also has drier and possibly cleaner bass, not weaker than than in floater mode, and more treble and high mids energy. It sounds more balanced, whereas floater mode is a bit darker all in all.
   
  Speaking of more treble energy, I have had some trouble reproducing the volume pattern that seemed obvious to me on my first try. While the strapped setting definitely is a bit louder for music, I am not sure that difference is still that relevant for weaker signals. On the strapped setting, it seems like I can turn the volume up about as much as I want without the sound getting immediately louder, but more like everything on the stage is just becoming more intense, more boundless and strong if you will. I was actually a bit bothered by this when watching a movie last night, as whatever volume I used, the audio was never loud -I mean it was still plenty loud though lol- but just _intense_ and surrounding; realistic at any rate, as it sounds like you're in a room, theater, opera room or open field. Both settings require me to go very high -too high imo- on the volume knob to watch videos though, as I need to get close to 12 o'clock to get things even a bit loud (I need 10 with my 6AV6, which is quite a _major_ difference!).
   
  About the slightly higher perceived volume for music -loud signals- on the strapped setting, I think the extra treble and high-mids energy plays a large part in that sensation, in that, I might be getting a bit more volume but perceive much more because of that.
   
  Anyway, don't panic because I mentioned _treble energy_; on my headphones, when I hear some powerful -not hot- high mids and treble frequencies and everything else at about the same level, it just basically means that I'm getting a very balanced sound originally; so you probably wouldn't even notice it with, say, HD650 or such; it would sound great on them actually, considering their "dark" nature.


----------



## MIKELAP

Would the 6CS6 be similar sounding to the 6be6. The telefunken and the siemens seem to sound  better than the other brands am i correct .i am still with the 6AV6 they seem to have settled down in the treble department or probably i did i think its more along those lines  i guess i really like those tubes soundstage wow . to be honest i like all the tubes we tried recently LETS GET SOME MORE. Ideas. I've tried the 6136,the,6ah6wa, 6av6,6cb6a,6ew6, am i up to date or is there something potentially better sounding. thanks.


----------



## gibosi

Since the 6CS6 is similar to the 6BE6 and the 6BY6, I expect that it will sound similar. However, I do not have a pair of these, and to my knowledge, no one has posted any impressions, so I really do not know... I hope someone (maybe you?) will get a pair of these and tell us how they sound. 
   
  Using the EF95 setting, I think the best sounding 6BE6 (EK90) are the Siemens and the Telefunken. I also really like the Amperex 6BY6 (E91H).
   
  Considering the 6AV6, I think the Mullard and the GE sound pretty good. And you might also want to try a pair of RCA 6AV6 with black plates.
   
  And yes, I think you are up to date!


----------



## mab1376

Quote: 





gibosi said:


> Since the 6CS6 is similar to the 6BE6 and the 6BY6, I expect that it will sound similar. However, I do not have a pair of these, and to my knowledge, no one has posted any impressions, so I really do not know... I hope someone (maybe you?) will get a pair of these and tell us how they sound.
> 
> Using the EF95 setting, I think the best sounding 6BE6 (EK90) are the Siemens and the Telefunken. I also really like the Amperex 6BY6 (E91H).
> 
> ...


 
   
  I still really want a pair of those Siemens EK90's to compare to my telefunkens.
   
  I think I'm going to pickup a pair of Amperex E91H's to try as well. Based on my research the E91H should not use the 7-1 strap ever since Grid3 is designed specifically for pulse shielding, not signaling.
   
  Also w00t for 400 posts!


----------



## gibosi

Quote: 





mab1376 said:


> I think I'm going to pickup a pair of Amperex E91H's to try as well. based on my research the E91H should now use the 7-1 strap ever since Grid3 is designed specifically for pulse shielding, not signaling.


 
   
  I figure we can't know for sure until we try both settings. As our understanding of exactly what is going on in these tubes as they are strapped into various configurations is very limited, it is very difficult to predict in advance how they will perform. For now, what I can say is that they sound incredibly good to me with grid 3 floating.
   
  However, I won't be able to try the 1-7 strapping for a while as I am now back in triode land....


----------



## mab1376

I'll give both a shot once i get them, coming from Colorado to NY should be by next week.
   
  -edit-
   
  So I the 7-1 strap on my TS 6BE6 and so far the results are bass seems much more forward and mids seems a bit recessed. Seems like standard V eq.
   
  Drums to sound really amazing on this setting while listening to some Muse.
   
  ...more to come.


----------



## Audiofanboy

Quote: 





mab1376 said:


> I'll give both a shot once i get them, coming from Colorado to NY should be by next week.
> 
> -edit-
> 
> ...


 
   
  While at first, I thought that the strapped setting didn't sound that much better or just a little better than the floated setting, upon re-trying, I found it to be a clear improvement imo.
   
  It does sound less intimate and warm to me than the floated setting but it's also less bloated and _much _clearer though, and I have found that it is, all in all, more balanced. Mids also seemed a bit less emphasized to me at first -more like high mids and treble seemed more emphasized instead, strings and wind instruments- but after a few hours of listening, the mids are clearly still there and the bass is more defined and articulate; I would say the highs aren't so much stronger than they are just clearer, which gives that temporary sensation of recessed mids before you forget the way it sounded before.
   
  And yes, drums and wind instruments sound absolutely amazing on that setting, just _there_, musical and realistic -on my Tele/vania 5915/EH900S that is.
   
  Basically, floated setting sounds very "pentode-like", whereas strapped setting sounds like a hybrid with everything I love about my best pentodes, and the detail and realism I loved about my best triodes; that, and the boudnless soundstage (I listened to the remastered Fleetwood Mac _Rumours_ last night, I don't believe I ever heard those songs sound so real and stage-like; listen to the song _Dreams_ from that record on that setting and you'll understand what I mean).


----------



## mab1376

My impressions we're with only one hour on that setting, normally grid 3 has no current, correct? So hopefully with some more burn in I'll start to hear the that endless soundstage you mentioned. That being said I do quite like what i heard with the Muse tracks I demo'ed with, especially the new album in 24/96! It was like seeing them live, which I did in April. My DAC upsamples to 192kHz which gives it a more airy sound.
   
  Also now that i know its safe i'll give it a go on the Telefunkens.


----------



## siles1991

currently using the EF95 Voshkods but was wondering if is there any tubes that would give more lush and full mids? Was thinking of either trying the Mullard m8100 or M8161


----------



## mab1376

Quote: 





siles1991 said:


> currently using the EF95 Voshkods but was wondering if is there any tubes that would give more lush and full mids? Was thinking of either trying the Mullard m8100 or M8161


 
   
  For EF95, M8100 is great for mids, Telefunken 6AK5W is better but a bit pricy.


----------



## MIKELAP

i like the 6av6 so i ordered some JAN G.E., JAN RCA, WESTINGHOUSE, and some   SYLVANIAS. will see how those compare to each other.


----------



## MIKELAP

Quote: 





mab1376 said:


> My impressions we're with only one hour on that setting, normally grid 3 has no current, correct? So hopefully with some more burn in I'll start to hear the that endless soundstage you mentioned. That being said I do quite like what i heard with the Muse tracks I demo'ed with, especially the new album in 24/96! It was like seeing them live, which I did in April. My DAC upsamples to 192kHz which gives it a more airy sound.
> 
> Also now that i know its safe i'll give it a go on the Telefunkens.


 
I to like the latest Muse album especially SURVIVAL accordind to my playcount i heard 57 times i guess i like it  i also have the 24/96 high def version ,pretty awesome punchy sound saw them originaly on tv for the olympics pretty memorable set.


----------



## gibosi

Quote: 





mab1376 said:


> I also received my Telefunken EH900S which i will try when I'm  feeling ambitious.


 
   
  Have you had a chance to listen to these? I am wondering if I should pick up a pair.....


----------



## mordy

Came across an inexpensive deal for three 1950's 6AQ6 Sylvania tubes ($3 each including shipping). These are part of the 6AV6 family, but I have not seen anybody testing them yet. My personal preference is other tubes. Perhaps somebody may be interested in these tubes so I am listing the link:
   
  http://www.ebay.com/itm/6AQ6-Diode-Triode-Tubes-Sylvania-1950s-NOS-Lot-of-3-Tested-Strong-/251289555588?pt=Vintage_Electronics_R2&hash=item3a82065284


----------



## mordy

Dear siles 1991,
   
  Why don't you take the plunge and buy a pair of Tung Sol 6AH6WA tubes instead of the Mullards? I have both the Voskhods and the Mullard 8100, and IMHO the TS are better. Substantially better.
   
  Then take those old broken earbuds that are sitting somewhere and cut two thin pieces of stranded wire a little longer than a standard staple, and make the 2-7 jumpers, using the EF95 setting.
   
  The rest is history.....


----------



## MIKELAP

Quote: 





mordy said:


> Dear siles 1991,
> 
> Why don't you take the plunge and buy a pair of Tung Sol 6AH6WA tubes instead of the Mullards? I have both the Voskhods and the Mullard 8100, and IMHO the TS are better. Substantially better.
> 
> ...


 
   Thanks to Audiofanboy and all you guys who found us new and especially way cheaper tubes to listen to we dont have to pay $15.00 $20.00 a tube for Mullard or Voshkods tubes to get good sound anymore,.I especially like these days the ones you mentionned mordy TUNG SOL 6AH6WA , also i like the 6av6 of which i ordered 10 today of 4 different manufacturer and they are not expensive less then $4.00 shipped. they should sound nice and open like my Hit Ray. doesnt have do be expensive but on the other hand got a spare pair of Electro Harmonix 6H30PI GOLD PINS well i guess you cant win em all.


----------



## gibosi

Quote: 





siles1991 said:


> currently using the EF95 Voshkods but was wondering if is there any tubes that would give more lush and full mids? Was thinking of either trying the Mullard m8100 or M8161


 
   
  Those of us who post to this forum regularly believe that there are a number of nontraditional tubes that are significantly better than either the M8100 or the M8161, or any other standard LD tube, and moreover, they are much less expensive. These would be the 6AU6, 6AH6 and the 6AV6. However, in order to use these tubes in your Little Dot, some small mods are required, namely cutting pins, or installing small temporary jumpers into your sockets. Rather than asking you to run and jump into the water head first, I would like to ask you to just dip your toe in to test the water. 
   
  Most of us believe that a 6BE6 is also superior to any of the traditional Little Dot tubes. And no little mods are required to use this tube. So I suggest that you find a nice cheap pair of Sylvania or Tung-Sol 6BE6, set your Little Dot for EF95 tubes, plug them in, and listen. I think you will be very pleasantly surprised. 
   
  Cheers!


----------



## siles1991

how do i make the 2-7 jumpers? will that affect the ability for me to use my voshkods as well?


----------



## siles1991

haha nvm ignore what I said I found the post regarding the jumpers. So basically I get a wire, should I tin it with solder? Would I need a thick cable or a thin one would do like the L4E6S I think its about 22-24AWG


----------



## inphu510n

siles1991 said:


> haha nvm ignore what I said I found the post regarding the jumpers. So basically I get a wire, should I tin it with solder? Would I need a thick cable or a thin one would do like the L4E6S I think its about 22-24AWG




26AWG or smaller would be ideal and it has to be stranded wire. The strands will be forced around the sides of the pin and will allow the tube to seat. Leave the wire jacket on the portion of the wire that isn't going into the socket. That'll allow you to not lose your mind dealing with a bunch of tiny loose wires.

I've soldered stranded copper wire between the pins on a set of Sylvania 6136 tubes. Probably a better solution if you can do it. The pins have to be scraped pretty clean but solder will definitely adhere to them. There's also a seller on eBay that we've ordered converters from and they work well but are over $40 shipped for a pair.


----------



## siles1991

Quote: 





gibosi said:


> Those of us who post to this forum regularly believe that there are a number of nontraditional tubes that are significantly better than either the M8100 or the M8161, or any other standard LD tube, and moreover, they are much less expensive. These would be the 6AU6, 6AH6 and the 6AV6. However, in order to use these tubes in your Little Dot, some small mods are required, namely cutting pins, or installing small temporary jumpers into your sockets. Rather than asking you to run and jump into the water head first, I would like to ask you to just dip your toe in to test the water.
> 
> Most of us believe that a 6BE6 is also superior to any of the traditional Little Dot tubes. And no little mods are required to use this tube. So I suggest that you find a nice cheap pair of Sylvania or Tung-Sol 6BE6, set your Little Dot for EF95 tubes, plug them in, and listen. I think you will be very pleasantly surprised.
> 
> Cheers!


 
  alright will check out the 6BE6, some people say matched pairs make a difference while others say they dont whats your opinion?
   
  Quote: 





inphu510n said:


> 26AWG or smaller would be ideal and it has to be stranded wire. The strands will be forced around the sides of the pin and will allow the tube to seat.
> 
> I've also soldered stranded copper wire between the pins on a set of Sylvania 6136 tubes. Probably a better solution if you can do it. The pins have to be scraped pretty clean but solder will definitely adhere to them. There's also a seller on eBay that we've ordered converters from and they work well but are over $40 shipped for a pair.


 
  I think i might try soldering wire to the pin or make the jumper like in the picture, would I need to tin the wire if I was making the jumper?


----------



## siles1991

is this the converter? http://www.ebay.com/itm/1x-6AU6-to-6AK5-tube-adapter-socket-converter-/300919049225?pt=Vintage_Electronics_R2&hash=item46102c4c09


----------



## Audiofanboy

Quote: 





siles1991 said:


> alright will check out the 6BE6, some people say matched pairs make a difference while others say they dont whats your opinion?
> 
> I think i might try soldering wire to the pin or make the jumper like in the picture, would I need to tin the wire if I was making the jumper?


 

 Matched tubes are pretty much a scam, as far as driver tubes go at least. Sellers test transconductance (gm) and not gain (mu) because that's what tubes testers do; and slightly different gm won't have a significant impact on channel balance (nothing you'll hear at any rate, unlike different mu). So, no, don't pay extra for matched driver tubes. Power tubes? Double triodes? Yes, matching matters (a lot for double triodes actually). Drivers tubes, nope.
   
  I would try the basic jumper method first; it's easy and reversible, and it's never failed me (just rearrange and re-insert the jumpers everytime you change tubes). *No tinning, no solid core wire*; you just want the least amount of "extra" metal in those tube sockets (gibosi will tell what happens when you stick solid core wire in there...), just use 26~30AWG stranded wire, preferably decent quality, and you'll be fine.
   
  Acapella11 had summed up all the requirements for the "new" or not native tube types a few dozen pages back; there's also a picture of what the jumpers and installed jumpers should look like.
   
  And yeah, forget about M8100 and M8161... Jump in the deep end of the pool right away; the water's quite nice here! Besides, like mikelap pointed out, those new and improved tube type are also... cheaper. So, there is very little reason to stick with the old overrated EF95 types.


----------



## siles1991

alright so just plain 26-30AWG wire non tinned/soldered and just 6H6WA in? Are the tung sols that mordy suggested good for mids? I'm looking for something that'd give me lush and smooth mids.


----------



## Audiofanboy

Quote: 





siles1991 said:


> alright so just plain 26-30AWG wire non tinned/soldered and just 6H6WA in? Are the tung sols that mordy suggested good for mids? I'm looking for something that'd give me lush and smooth mids.


 

 For lush, my old favorites are still the Tung-Sol 6485 (6AH6 type). Some Tung-Sol 6AH6 don't have the same build as the 6485, so they might sound different.
   
  Some of the 6AU6 family are very nice too, and safe choices. Mordy can point you in the right direction for those.
   
  But the best -currently in testing- I've found as of late, apart from the triodes, are those premium quality heptodes like the 5915/EH900S. Depending on the setting you use them on, they can be somewhat lush or open and detailed; awesome regardless, and, again, cheap for what they are...


----------



## mab1376

Quote: 





gibosi said:


> Have you had a chance to listen to these? I am wondering if I should pick up a pair.....


 
   
  Not yet, been to lazy to swap the jumper lol.
   
  I did finally get my 6AU6/6AH6 adapter in the mail, the ones that work.


----------



## mab1376

Quote: 





siles1991 said:


> alright so just plain 26-30AWG wire non tinned/soldered and just 6H6WA in? Are the tung sols that mordy suggested good for mids? I'm looking for something that'd give me lush and smooth mids.


 
  get these, http://www.ebay.com/itm/USAF-Tung-Sol-6AH6WA-6485-NOS-New-Old-Stock-Electron-Tube-Valve-/221204354204?pt=Vintage_Electronics_R2&hash=item3380ce949c
   
  and those are the adapters, but the jumpers are easy to make and need no soldering. Just 26AWG stranded wire and jump pins 2-7 as shown in the pics in previous posts.


----------



## mordy

Spend two dollars more and get 5 tubes instead of two: ($8.55 vs $3.80 each)
   
   
  http://www.ebay.com/itm/JAN-6AH6-WA-Tubes-Tung-Sol-1967-NOS-Lot-of-5-Tested-Strong-/251292583548?pt=Vintage_Electronics_R2&hash=item3a8234867c


----------



## gibosi

Quote: 





mab1376 said:


> Not yet, been to lazy to swap the jumper lol.
> 
> I did finally get my 6AU6/6AH6 adapter in the mail, the ones that work.


 
  Change jumpers? But aren't you still listening to the EK90? For the EH900S (and the Amperex E91H) you would use the same jumper setting, EF95. So stick them in and tell us what you hear! lol


----------



## Audiofanboy

Speaking of E91H and EH900S, I just found and bought a pair of each for decent prices (read 7-8€ a tube incl. shipping) in Europe, so I'll be able to give more impressions on those heptodes pretty soon!
   
  One pair is Philips E91H/CV8697 -so UK mil spec, kind of an added bonus- made in Holland, most likely Heerlen factory. These should be strictly identical to gibosi's Amperex E91H, and they even have those markings on top like his do.
   
  The other tubes I'd wanted to get since a while ago but was lost in triode land -which I'll return to pretty soon- are genuine -unlike my current Sylvania-made- Telefunken EH900S with gold pins, that even include a large piece a paper with a tube-specific warranty in each box. Again, I am surprised by how little these cost me for -objectively- premium type tubes (these are actually rated for 10K hours, and I do like plated pins, whether it's gold or rhodium -like Russian tubes- I don't care, I just like the fact that they don't oxidize at all).
   
  And speaking of triodes, I just got my last Lorenz EBC91 I was missing (which means that I have another spare pair of them now, if anyone's interested), and also some Philips 6AT6/CV452 -again UK mil-spec- with top D-getters, made in Heerlen, Holland, like Amperex and Bugle Boys tubes (and I also bought an extra pair of these, if anyone's interested).
   
  I'll test the CV452 in a few days when I get another package of triodes I'm waiting for (I hate to manhandle the amp too often just to change jumpers, so I try to rationalize jumper changes somewhat; it tries my patience, but I think I can manage lol).


----------



## inphu510n

siles1991 said:


> is this the converter? http://www.ebay.com/itm/1x-6AU6-to-6AK5-tube-adapter-socket-converter-/300919049225?pt=Vintage_Electronics_R2&hash=item46102c4c09


 

Without visiting the link I'm 90% sure those are the ones you want.


----------



## mab1376

Quote: 





gibosi said:


> Change jumpers? But aren't you still listening to the EK90? For the EH900S (and the Amperex E91H) you would use the same jumper setting, EF95. So stick them in and tell us what you hear! lol


 
  OK then, I was going to use the EF92 settings, but i'll give the EF95 setting a try this weekend.


----------



## Acapella11

Hi everyone here, I wasn't lazy posting, I was on holidays and basically offline. This thread has gone on like crazy again, as expected, lol, and I have just updated myself. Great stuff about the heptode grids AFB. 1 - 7 strapping is now the top bullet point on my list =)
   
  I am expecting some Amperex E91H (6BY6) and Russian 6A2P (6BE6) tubes. Once we are through the new strap mod options, I am going to update the table on page 77 respectively. Sounds like a lot of fun ahead!


----------



## mab1376

Quote: 





acapella11 said:


> Hi everyone here, I wasn't lazy posting, I was on holidays and basically offline. This thread has gone on like crazy again, as expected, lol, and I have just updated myself. Great stuff about the heptode grids AFB. 1 - 7 strapping is now the top bullet point on my list =)
> 
> I am expecting some Amperex E91H (6BY6) and Russian 6A2P (6BE6) tubes. Once we are through the new strap mod options, I am going to update the table on page 77 respectively. Sounds like a lot of fun ahead!


 
   
  Let me know how those Russian tubes sound! Might be a good pair with Russian 6n6p type power tubes. Waiting on my own Amperex E91H tubes as well, curious to see how they sound! the 6BE6 type tubes do have a pleasingly different flavor with the 7-1 strap, give it a shot if you have some on hand!
   
  Have fun!


----------



## mab1376

Quote: 





mab1376 said:


> OK then, I was going to use the EF92 settings, but i'll give the EF95 setting a try this weekend.


 
   
  They TFK EH900S sound very vanilla. Not too punchy, not too harsh. They also lack a bit of detail.
   
  This was also with no burn in.
   
  Also, great test track:


----------



## gibosi

I hope they improve after burn in....
   
  Are your TFK EH900S also labeled E91H? I have found some EH900S with gold pins and in another location some EH900S/E91H with regular pins. Further, I believe the gold pins are newer, with O-getters and the regular pins are older, with D-getters.
   
  Which to get? But I think I will wait until I hear more about yours...


----------



## Audiofanboy

Quote: 





mab1376 said:


> They TFK EH900S sound very vanilla. Not too punchy, not too harsh. They also lack a bit of detail.
> 
> This was also with no burn in.
> 
> Also, great test track:


 

 Out of curiosity, you wouldn't have a picture of those tubes, or, like, the ebay ad you bought them from; just for reference? There seems to be more than a few different types of Telefunken EH900S out there apparently...


----------



## Audiofanboy

If anyone -living in the US- is interested, I found these on ebay:
   
http://www.ebay.fr/itm/Amperex-6687-NOS-Made-in-Holland-/140973286651?pt=Vintage_Electronics_R2&hash=item20d2a9a4fb
   
  They should/could/might be the same as gibosi's or my future Holland-made E91H (gibosi's are dual labeled 6687), but no guarantee. They're pretty cheap anyway, so it's not exactly a huge risk...


----------



## MIKELAP

Compared HIT RAY 6AV6, GE6136, AND USAF 6AH6WA and the HIT RAY and the USAF i would say are pretty similar sounding soundstage is wide, detailed ,balanced sound . going to get more of those  6av6 i like em alot and the 6ah6 good tubes gor the price. As for the GE 6136 no more of those but ill burn em in anyways who knows maybe they will improve or just to rid them of the microphonics.


----------



## mab1376

Quote: 





audiofanboy said:


> Out of curiosity, you wouldn't have a picture of those tubes, or, like, the ebay ad you bought them from; just for reference? There seems to be more than a few different types of Telefunken EH900S out there apparently...


 
   
  I specifically went for the gold pin version: http://www.ebay.com/itm/320521115105?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649
   
  I also got a pair of these to try: http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=370824602237


----------



## MIKELAP

On the way 10 JAN GE, JAN RCA, WESTINGHOUSE,SYLVANIA  6AV6'S, AND 5 6BY6 RCA'S  well see i they sound alike or not i guess ill be set for life one way or the other .


----------



## gibosi

While I have the others, I haven't heard the Westinghouse 6AV6, so I will curious to read your impressions. And yes, these plus the 6BY6 should keep you busy for a while, but maybe not for the rest of your life!


----------



## Audiofanboy

Quote: 





mab1376 said:


> I specifically went for the gold pin version: http://www.ebay.com/itm/320521115105?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649
> 
> I also got a pair of these to try: http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=370824602237


 

 Great, now I can compare a little.
   
  Your Telefunken EH900S are probably different from the ones I ordered (yours have a silk-written number on top and different shape from the ones I ordered, and those have "Made in Germany" written; so I wouldn't be surprised if we find different impressions for different Telefunken EH900S - I've seen up to 4 or 5 different versions on ebay actually, and only two that I could identify as being made by Tele for sure).
   
  I'm also curious as to what those Lorenz tubes will sound like. These were evidently made in Eastern Europe / USSR (saucer type getter, pointy shiny pins, general glass shape...) but should be pretty high grade since they're German mil-spec. I do find it interesting that the -West?- German military would end up using Russian tubes when its main threat in that time was their same Eastern neighbors, but oh well, such is life I guess lol.


----------



## MIKELAP

Quote: 





gibosi said:


> While I have the others, I haven't heard the Westinghouse 6AV6, so I will curious to read your impressions. And yes, these plus the 6BY6 should keep you busy for a while, but maybe not for the rest of your life!


 
  i ordered them today finally from FLA.should be here within a week i guess .  so 15 tube came out to $55.00 including shipping which comes out to $3.66 each thats a good price my guy here was charging me up to $10.00 each .hey mordy you must proud of me because i learn this from you on this thread  earlier on when i first got my littledot , that you dont have to pay a fortune to have decent sound thanks for that


----------



## mordy

HI Mikelap,
   
  You made my day - thanks!


----------



## gibosi

I have had a little time to listen to the Siemens EK90 and the Amperex E91H using the 1-7 strapping. I don't quite know how to say this, but it is as if the warmth of the Amperex turns a bit too sweet after strapping. In my mind, these are much better unstrapped. On the other hand, the Siemens strapped sound incredibly good, I encourage those of you who were lucky enough to get these Siemens to "strap them in" and give them a try.  
   
  I hope to get to the Telefunken EK90 later. And just to be thorough, I also plan to try the GE JG 5760/6BE6W and RCA 5915/6BY6 as well.


----------



## Acapella11

I like to first summarize the functional principle of what which strap does to heptodes. By doing this, I repeat Audiofanboy and myself but I found it useful to put recent findings into a bigger picture. 
  
 Let’s remind ourselves on how the LD strips 6AK5 pentodes to triodes:
  
 *Anode* = LD PCB wires pin 5 (anode) to pin 6 (grid 2); in EF91/92 operation, jumper connects pin 7 (grid 3) to anode and grid 2. Effectively, pins 5, 6 and 7 are connected.
 *Grid* = Pin 1 (grid 3)
 *Cathode* = Pin 2 (cathode), 6AK5 tubes wire internally pin 7 (grid 3) to pin 2.
  
 For heptodes, this allows four modes of operation to utilize pin 7 (q3, mixer grid), without heavy mod operations:
  

 “*Grid Strap*” (1/7 strap), Audiofanboy’s suggestion to connect pin 7 (q3, mixer grid) to pin 1 (regular LD grid, q1). This results in a double grid, which is neither cathode nor anode strapped. Sounds great.
 *Floating grid*. Mixer grid, pin 7 is not connected, which would in the original mode of operation be used to add the oscillator frequency to the radio frequency. Works fine and yields great sound.
 *Anode strap* in EF91/92 setting, found to yield sub optimal sound performance.
 *Cathode strap* (2/7 strap), found to give poor sound performance.
   
 It would be nice to find a general consensus on the strapology of heptodes but we might end up just saying tube A is the best with this setting and B is close with its preferred strap.
  
 *Comparison*
  
 Initial remarks: I haven't made this easy for myself but obviously the transferability to other tubes may not be given.All observations were done using the Siemens EK90 (6BE6) in EF95 setting.
  
 *1/7 strap*: better definition / resolution, more forward, harder, drier, faster, bass is deeper, better articulation, more treble presence, more bass punch, better instrument separation, higher gain. Width of stage is not negatively affected.
 *Float*: slightly more diffuse, softer, wetter, airier, more ambience, more instrument body, sweeter, more bass presence, bass goes a bit deeper, “tubier”. The plus of ambience makes the stage feel deeper and the room itself more present. 
  
 *1/7-Triode touch*: Yes, it is there. Transparency, definition of imaging, drier character / lesser perception of ambience.
  
 *1/7-Gain*: I find the tube also slightly louder with the 1/7 strap compared to float setting. For the operation with an external oscillator, Brimmar suggests that highest gain would be achieved with a voltage of – 2 V on the oscillator.
  
 *Overall*, the Siemens EK90 was already revealing with the float setting, which is like an easy-to-listen-to setting giving lots of ambience. After strapping it becomes an analytical audio instrument with the only disadvantage that it reduces the ambience perception, which - in full reproduction mode - is quite nice on my Senns. Either 1/7-strap or no strap, the tube sounds great. At the moment, if I had to choose, my favour would go to the 1/7-strap because of its definition / resolution but I would have to do a few even longer listening sessions for ultimate conclusion. This would be my best sounding setup overall.
  
 1/7-strap comparison between tubes
  
 *Siemens *EK90 (6BE6) sounds more transparent, airier, more treble presence (“triode touch”), bass most differentiated, *Tung Sol *6BE6 gentler with more ambience, more relative bass presence, more tube like, between Siemens and Sylvania. *Sylvania *JAN 5750, most relative bass presence, sounds darkest.
  
 In order to compare cross family differences, I sought to find a Siemens 6BY6 (EH900, EH900S, EH960, E91H), but couldn't find one. In contrast, the 6CS6 (EH90) are easily available, which aren't yet in my collection. I bought a pair of those. 
  
 Gibosi, excellent work reviewing the heptodes on page 105. I was starting to go through my heptodes as mentioned above but I have to come back later to draw more detailed conclusions between tubes. Funny, I just came up with this post after you strapped your Siemens EK90.
  
 Mordy, I think you would probably favour a 1/7-strapped heptode, because it yields more treble presence, sounds more forward. I am guessing you just need the right manufacturer to suit your sweet tooth.
  
 Audiofanboy, The depth of stage / ambience effect is IMO probably differently highlighted depending on headphones, especially considering that the HE-500 is known to not have a very deep stage and the HD800 produces one of the largest volumes of stage spaces. I might use the HE-500 for comparison as well at one point. As for your larger quantity of the positive treble energy, this is probably what I have described as  treble presence and it looks like we agree on this one.
  
 Update: Added EF95 setting info.


----------



## mordy

A11,
   
  Thanks for your in depth post. Just to make it clear to myself, are all the various figurations using the E95 setting?


----------



## Acapella11

Quote: 





mordy said:


> A11,
> 
> Thanks for your in depth post. Just to make it clear to myself, are all the various figurations using the E95 setting?


 

 Yes


----------



## Audiofanboy

Quote: 





acapella11 said:


> Yes


 

 Well, good lord, that's some great work A11! More synthetic and easy on the eyes than when I write my own conclusions lol...!
   
  But, yes, the strapping setting does, on my setup, give a unique, and profoundly engaging sound, unlike anything I heard in those past months of rolling. The treble presence/detail/energy, and the way the stage and instruments are rendered is quite an out of this world experience; _seriously_.
   
  The one thing I think we need to find a consensus of sorts on -or basically a pattern- is whether this pin 7-1 mod yields the same results for all three identified types of heptodes. There are inherent differences in the way 6BE6, 6BY6 and 6CS6 tubes are built and function -regardless of their intended application though it would be linked- especially on the cutoff characteristics of grid 3, so we _should_ expect to find _some_ degree of difference. For 6BE6 tubes, I read somewhere (too tired to find and post the quote, but I'll edit afterwards) that grid 3 exhibits remote-cutoff curves, whereas the -yet untested, how is that even possible btw?- 6CS6's grid 3 is your typical sharp-cutoff; haven't found how grid 3 behaves for 6BY6 yet.
   
  All I can say for now, before I get my next premium 6BY6 types, is that my strapped 5915 give me the greatest listening pleasure and staging (large, deep, wide, and realistic) I've heard on my HE-500; and I'm pretty sure that the treble presence/detail/energy would complement many people's Senn HD650 phones _very_ well too.
   
  Nice work though chaps, _this_ here, what we've just found out, is a clear and obvious breakthrough, the likes of which I don't believe we'd had since testing the 6AU6 and 6AH6 families -that and some triodes as a side job lol!


----------



## mordy

Hi all, and especially thanks for your encouragement,
   
  Looks like I did something wrong the first time I set up the 1-7 strap with the heptodes. In general I have always been in consonance with every-body's findings on these wonderful new tubes, and it bothered me that I could not hear what others were describing.
   
  Now I tried again, and the sound is just great!
   
   
"Mordy, I think you would probably favour a 1/7-strapped heptode, because it yields more treble presence, sounds more forward. I am guessing you just need the right manufacturer to suit your sweet tooth."
   
  "The treble presence/detail/energy"
   
  Yes i do like sweets, and this is real ear candy. My RCA 6BY6 tubes now sound exactly like you described with plenty of volume. There is a lot of energy and detail in the highs.
   
  Very happy that I can enjoy the heptodes now!
   
   
  After spending some time with these I will report again.


----------



## MIKELAP

I am listening to some TUNG-SOL 6BE6 with 7-1 strapping on EF-95 setting very nice sounding with the senns   and my go to tune DUKE ROBILLARD ALBIE AINT HERE  xylophone  is crisp bass to die for  i think i gonna  cry jjjjjjust kitting anyway another great tube will check them again without strapping to see the difference could these be the best tubes ive heard im not worth c.....p at describing but i now a good tube when i hear one ..Good nite and have a pleasent tomorrow.


----------



## gibosi

Mikelap... Mordy... Glad to see that heptode land is agreeing with you! 
   
  This evening I quickly checked out the Telefunken EK90, GE JG 5760/6BE6W and RCA 5915/6BY6. Mind you, this was listening to each tube for about 2 minutes. I just wanted to see if it would be worth my while to spend more time with any of them.
   
  The Results: The TFK and the RCA easily passed the test, but the GE couldn't hold my interest for even 2 minutes! lol  Oh, and I just remembered that I have a pair of Brimar CV4012.... I need to test them too.....


----------



## Audiofanboy

OK, I found the information I was missing last night, on the cutoff characteristics of grid 3 on those heptodes; and I found it from a more official source than forums this time: the datasheets -which I'd had for weeks...
   
  So:
   
  - 6BE6: grid 1 = sharp cutoff, grid 3 = remote cutoff (cutoff in triode mode when tied together *?* )
  - 6BY6: grid 1 = sharp cutoff, grid 3 = sharp cutoff (so we'd expect a sharp cutoff trait when triode strapped, probably...)
  - 6CS6: grid 1 = sharp cutoff, grid 3 = sharp cutoff (so same as above...?)
   
  Just food for thoughts...


----------



## siles1991

Is there any good power tubes to replace stock for the LD MKIII without breaking bank? electro harmonix 6h30pi is a bit expensive.


----------



## mab1376

Quote: 





audiofanboy said:


> OK, I found the information I was missing last night, on the cutoff characteristics of grid 3 on those heptodes; and I found it from a more official source than forums this time: the datasheets -which I'd had for weeks...
> 
> So:
> 
> ...


 
   
  I'm currently testing the EH900S with the 2-7 strap and I'm finding that they have a very detailed presentation with a decent soundstange compared to my previous EF95 configuration with a blasé experience.
   
  Drums are also very punchy and quick, even on the HD650. Some harder Buckethead stuff really shines with this configuration.


----------



## mab1376

Quote: 





mab1376 said:


> I'm currently testing the EH900S with the 2-7 strap and I'm finding that they have a very detailed presentation with a decent soundstange compared to my previous EF95 configuration with a blasé experience.
> 
> Drums are also very punchy and quick, even on the HD650. Some harder Buckethead stuff really shines with this configuration.
> 
> ...


----------



## mordy

Dear Mab 1376,
   
  Here is a link to German EBay for Siemens EK90 tubes (three offerings, but don't know about pairs - you have to ask seller):
   
  http://www.ebay.com/sch/i.html?_from=R40&_sacat=0&_nkw=Siemens+EK90&LH_PrefLoc=2
   
  To find these tubes when you go to EBay, look on the left  and scroll down to the heading Location; then click on Worldwide.
   
  Hope this is of help


----------



## mab1376

Quote: 





mordy said:


> Dear Mab 1376,
> 
> Here is a link to German EBay for Siemens EK90 tubes (three offerings, but don't know about pairs - you have to ask seller):
> 
> ...


 
   
  Looks like they all only have one each.
   
  I usually try a buy in pairs with similar date codes, I've had some issues in the past where there was a noticeable difference between channels.


----------



## Acapella11

Quote: 





siles1991 said:


> Is there any good power tubes to replace stock for the LD MKIII without breaking bank? electro harmonix 6h30pi is a bit expensive.


 
   
  My suggestion is 6N6P-IR. For me, the best solution before and way cheaper than the 6H30P-DR. Don't be fooled by the 500 h guaranteed time of operation. This is under impulse mode, which we don't use with the LD. Since it is made for even worse conditions than normal power tubes, I am guessing that it lasts at least as long as any other regular 6N6P tube. The R means a special low noise quality, which also is a special feature indicating a tube of highest quality. As for years of production, try to buy pre-1984 power tubes, as this indicates tubes of the old Russian quality.


----------



## gibosi

Quote: 





mordy said:


> Dear Mab 1376,
> 
> Here is a link to German EBay for Siemens EK90 tubes (three offerings, but don't know about pairs - you have to ask seller):
> 
> ...


 
   
  And further down the page, under "More items related to "Siemens EK90" there is one listing with 5 available:
   
  http://www.ebay.com/itm/EH90-EH-90-6CS6-SIEMENS-NOS-NEW-MCINTOSH-/370825161972?pt=DE_TV_Video_Audio_Elektronenr%C3%B6hren_Valves&hash=item5656e6ecf4
   
  However, these look a little different than mine. Mine have ribbed plates, whereas, as best I can see, these do not. Mine also have a three digit number below EK90, and these do not. And we cannot see if these have O-getters. And further, we can't see the bottom of these tubes, but mine have an embossed number in the glass between the pins. All that said, even though they look a little different, they certainly look genuine, 
   

   
  Edit: Oh, my bad! That link is for EH90/6CS6, not the EK90!!  Sorry!!  (>_<)


----------



## mab1376

Quote: 





gibosi said:


> And further down the page, under "More items related to "Siemens EK90" there is one listing with 5 available:
> 
> http://www.ebay.com/itm/EH90-EH-90-6CS6-SIEMENS-NOS-NEW-MCINTOSH-/370825161972?pt=DE_TV_Video_Audio_Elektronenr%C3%B6hren_Valves&hash=item5656e6ecf4
> 
> ...


 
   
  Yeah I almost did the same thing, similar name and appearance can throw you off lol.


----------



## Acapella11

These are 6CS6 tubes. Might be a good idea as well though =)
   
  Here is a link for various types of 6BE6 tubes, which is a Turkish tube store as indicated by the translation of the headlines. They seem to be pretty well sorted:
   
  http://www.nostubestore.com/2012/08/various-ek90-6be6-5750-cv4012.html
   
  I have just started to burn in the Amperex 6687 E91H (6BY6) and first impression is that they are tubier than the Siemens EK90 (6BE6) tubes but pleasant indeed. They indeed seem to sound opener and more interesting non-strapped as already indicated by gibosi:
   
  Quote: 





> I have had a little time to listen to the Siemens EK90 and the Amperex E91H using the 1-7 strapping. I don't quite know how to say this, but it is as if the warmth of the Amperex turns a bit too sweet after strapping. In my mind, these are much better unstrapped.


----------



## Audiofanboy

Hate to point this out, but the Siemens EK90 on ebay mentioned here are either Russian/Eastern European (saucer getter) or Mullard/Philips group. Same applies to the link for Siemens EH90, most likely Mullard or Philips, and different construction from -genuine?- Siemens like the pics on this thread...
   
  I'd wait find one like the pic gibosi posted if you want the same sound; though I'm sure the Russian and Mullard types are also worth a try.


----------



## Acapella11

For clarification:
   
  My Siemens EK90 are saucer getter type tubes. I encourage buying them. 
   

   
  And to complete the series, here are my softer sounding Amperex E91H (6BY6) tubes, which I just started to enjoy unstrapped.


----------



## siles1991

all of the 6N6P-IR i find from ebay are expensive just for a single unit O_O


----------



## Acapella11

Quote: 





siles1991 said:


> all of the 6N6P-IR i find from ebay are expensive just for a single unit O_O


 

 $40 a pair incl. shipping, no information about the year of production though, but can be asked. Says 88 on the glass. So, if this is a photo from what they sell, they are from 1988:
  http://www.ebay.co.uk/itm/6N6P-IR-ECC99-E182CC-high-durable-double-triode-tubes-Lot-of-2-pc-NOS-/300693108383?pt=LH_DefaultDomain_0&hash=item4602b4b69f
   
  $52.50 a pair incl. shipping, but on the photo and according to the description these are from 1974:
  http://www.ebay.co.uk/itm/2St-6N6P-iR-ECC99-E182CC-Hi-End-Militar-Rohre-Neu-Seltenheit-/140995515510?pt=DE_TV_Video_Audio_Elektronenr%C3%B6hren_Valves&hash=item20d3fcd476
   
  $38 a pair incl. shipping, no year given, photo looks like the one from the first above post:
  http://tubes-store.com/product_info.php?manufacturers_id=19&products_id=519&osCsid=ul4s0gk0bbbr5qe5qhhh3m1er2
  I have bought there and mine are from 1974, so the photo could just be a place holder.


----------



## gibosi

Quote: 





acapella11 said:


> These are 6CS6 tubes. Might be a good idea as well though =)
> 
> Here is a link for various types of 6BE6 tubes, which is a Turkish tube store as indicated by the translation of the headlines. They seem to be pretty well sorted:
> 
> http://www.nostubestore.com/2012/08/various-ek90-6be6-5750-cv4012.html


 
   
  If you anyone is interested in Siemens and Telefunken 6CS6/EH90, these look genuine, and including shipping, are not at all expensive. I have a pair of each coming to me.
   
  http://www.ebay.com/itm/251035838020?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649
   
  http://www.ebay.com/itm/261191506815?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649
   
  And I got my Siemens and Telefunken EK90 and Brimar CV4012 from the NOS Tube Store, but I remember reading a posting here that they no longer have the Siemens....


----------



## Acapella11

Quote: 





gibosi said:


> If you anyone is interested in Siemens and Telefunken 6CS6/EH90, these look genuine, and including shipping, are not at all expensive. I have a pair of each coming to me.
> 
> http://www.ebay.com/itm/251035838020?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649
> 
> ...


 
   
  I got bought these Siemens EH90 tubes. Thanks for posting this.


----------



## siles1991

referring to the chart on pg 77 I cant find how to use EH90 tubes you posted?


----------



## mab1376

Quote: 





gibosi said:


> If you anyone is interested in Siemens and Telefunken 6CS6/EH90, these look genuine, and including shipping, are not at all expensive. I have a pair of each coming to me.
> 
> http://www.ebay.com/itm/251035838020?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649
> 
> ...


 
   
  I bought the TFK's from them, and when I went back to order the Siemens they were already sold out.


----------



## Acapella11

Quote: 





siles1991 said:


> referring to the chart on pg 77 I cant find how to use EH90 tubes you posted?


 

 The table is updated now and includes also the 1/7-strap for heptodes. EH90 = 6CS6.
   
   
  Gibosi and evryone with an Amperex E91H, I am just listening to the Amperex E91H in EF91/92 and EF95+2/7-strap settings. Give it a go and tell me what you think.  I am not sure it gets better than unstrapped but it is still interesting.


----------



## MIKELAP

Quote: 





acapella11 said:


> $40 a pair incl. shipping, no information about the year of production though, but can be asked. Says 88 on the glass. So, if this is a photo from what they sell, they are from 1988:
> http://www.ebay.co.uk/itm/6N6P-IR-ECC99-E182CC-high-durable-double-triode-tubes-Lot-of-2-pc-NOS-/300693108383?pt=LH_DefaultDomain_0&hash=item4602b4b69f
> 
> $52.50 a pair incl. shipping, but on the photo and according to the description these are from 1974:
> ...


 
  2 new  matched 6H30PI GOLD PIN come up to $83.89 U.S. shipped in Canada 
   
   
   from PARTS CONNEXION in Canada


----------



## mordy

Does anybody have any idea about the quality of Italian made tubes by the brand name FIVRE?


----------



## siles1991

Quote: 





acapella11 said:


> The table is updated now and includes also the 1/7-strap for heptodes. EH90 = 6CS6.
> 
> 
> Gibosi and evryone with an Amperex E91H, I am just listening to the Amperex E91H in EF91/92 and EF95+2/7-strap settings. Give it a go and tell me what you think.  I am not sure it gets better than unstrapped but it is still interesting.


 
  alright thanks does it mean I can run it with ef95 settings and just stick it in?


----------



## mab1376

Quote: 





siles1991 said:


> alright thanks does it mean I can run it with ef95 settings and just stick it in?


 
   
  The immediate change I notice with the Amperex on 2-7 strap is a much brighter and forward presentation compared to on standard EF95 with a sweet relaxed sound.


----------



## mab1376

Quote: 





mab1376 said:


> The immediate change I notice with the Amperex on 2-7 strap is a much brighter and forward presentation. listening to some Rodrigo y Gabriela it has a very wide soundstage. Compared to it on the standard EF95 settings with a sweet relaxed sound.
> 
> My Raytheon 6GX6 sound also very nice with the 2-7 strap, much like the EH900S. Previously I was only using them with EF92 settings. Very transparent, like there's nothing between me and the music. Amazing for Jazz.


----------



## MIKELAP

Was reading page 77 .DId i understand this correctly . when my jumpers are  in EF95 mode if i strap PIN 6 AND 7  i will be in EF 91/92 mode is that correct if it is im gonna kick myself in the b.... and probably more than once !


----------



## mab1376

Quote: 





mikelap said:


> Was reading page 77 .DId i understand this correctly . when my jumpers are  in EF95 mode if i strap PIN 6 AND 7  i will be in EF 91/92 mode is that correct if it is im gonna kick myself in the b.... and probably more than once !


 
   
  If that's the case I'm never changing jumpers again!


----------



## gibosi

Quote: 





mikelap said:


> Was reading page 77 .DId i understand this correctly . when my jumpers are  in EF95 mode if i strap PIN 6 AND 7  i will be in EF 91/92 mode is that correct if it is im gonna kick myself in the b.... and probably more than once !


 
  The Little Dot straps pins 5 and 6 together on the circuit board regardless of what setting you use. So if you strap 5 and 7, as we have been doing for triodes, this is actually the same as strapping 6 and 7. So, yes if you strap either 5 and 7, or 6 and 7, you can run EF 91/92 tubes in the EF 95 setting.


----------



## MIKELAP

Quote: 





gibosi said:


> The Little Dot straps pins 5 and 6 together on the circuit board regardless of what setting you use. So if you strap 5 and 7, as we have been doing for triodes, this is actually the same as strapping 6 and 7. So, yes if you strap either 5 and 7, or 6 and 7, you can run EF 91/92 tubes in the EF 95 setting.


 
  OUCH! OUCH!


----------



## Acapella11

Quote:


> Originally Posted by *mab1376* /img/forum/go_quote.gif
> 
> My Raytheon 6GX6 sound also very nice with the 2-7 strap, much like the EH900S. Previously I was only using them with EF92 settings. Very transparent, like there's nothing between me and the music. Amazing for Jazz.


 
   
 Try the 6EW6 with 2/7 strap, I found it cleaner than the 6GX6. Sounds a bit bass weaker but opener and quite nice really. The nice heptodes are still a class up though IMO. Amperex E91H 2/7-strap sounds very nice, yes brighter and not too much ambience but more neutral with better definiton. It feels a bit like in tube wonderland. 
  
   
       Quote:


siles1991 said:


> alright thanks does it mean I can run it with ef95 settings and just stick it in?


 
   
  Yes.


----------



## mab1376

Quote: 





acapella11 said:


> Try the 6EW6 with 2/7 strap, I found it cleaner than the 6GX6. Sounds a bit bass weaker but opener and quite nice really. The nice heptodes are still a class up though IMO. But it feels a bit like in tube wonderland.


 
  I have so many on my desk i've been cycling through, I do very much like the TFK EK90 but i haven't even tried it with the optimal 7-1 strap yet.
   
  TS 6BE6
  TFK EK90
  Lorenz EK90 (on the way)
  Amperex E91H
  Raytheon 6GX6
  TFK EH900S
   
   
  I found a pair of Raytheon 6EW6 to compare. I'll see how i like it in comparison once I get them.


----------



## Acapella11

And here comes the next one:
   
  1/7-grid strap for 6CB6, 6CJ6, 6DK6, 6EW6, 6GM6, 6AM6, 6GY6/6GX6, lol
   
  Tested for 6EW6 and 6GY6/6GX6. Sounds a bit slower and with very round treble. Probably not the optimal setting but works fine and sounds OK.
  Could somebody confirm this for the other families, just to be sure?
   
  Who said can of worms...? haha


----------



## MIKELAP

Tested Hit Ray 6cb6a with 2-7 strapped pretty good bass with the closed Denons how sweet it his nice and clean right after cant believe i missed this i mean right after with 5-7 wire mod to EF91-92setting with Hit Ray 6av6 5-6 pin cutoff tighter bass wider soundstage cleaner sounding a bit . what nice tubes we are sampling these days .


----------



## mordy

Hi A11,
   
  Tried my Tung Sol 6CB6 with the E95 1-7 strap. Yep it works, but no, does not sound right. What comes to mind is a transistor radio that is not tuned on the spot. You can hear clearly but the sound is off - sounds sibilant and compressed with details and dynamics missing.
   
  Switched back to my RCA 6BY6 tubes with the 1-7 strap. Delicious, everything is there with a glorious super detailed shimmering
  high end. However, I am missing the punchy bottom end, sound stage and instrument separation of my Tung Sol 6AH6WA tubes.
   
  Which heptode would combine both virtues? The Siemens EH90?
   
  Truth is, I ordered a pair of the Siemens EH90 based on Gibosi's recommendation - thanks. Because of my self imposed limit of $8/tube including shipping, I took a chance on the best offer feature and offered 4 instead of 5 euros/tube, which, with shipping, brought it down to under $8/tube. The offer was accepted - will report when the tubes arrive.
   
  OK - a confession, since everybody on this blog is self effacing and don't mind admitting mistakes and blunders. Some time back I reported that the RCA heptodes I tried on the EF95 1-7 strap had a very low volume and did not sound right. I finally found out what the problem was: I tried to be too organized! I actually opened the RCA 6BY6 boxes and took out the two tubes and tried them - sounded awful! Why? I had put two unknown 6AU6 tubes in there with the markings worn off - wrong tubes! Please strike my previous post #1671 from record.
   
  I have to go back to my shoe box storage with pairs of tubes joined together with rubber bands. That way I have to look at the tubes before I put them in and don't have to rely on the box markings.....
   
  Right now I am listening the these wonderful heptodes - all what they are hepped up to be!


----------



## Audiofanboy

I got a pair of Telefunken EH900S tubes in the mail today. Genuine Ulm factory Tele tubes with golden pins -and "Made in Germany" actually written on the glass- they look like the ones here:
   
  http://www.radiomuseum.org/tubes/tube_eh900s.html
   
  These are heavy. Like, Russian -DR standard heavy. Thick glass, _thick_ metal poles holding the grids inside the tube, and clean solder points to -did I mention _thick_?- wires at the tube base. These look great and without any doubt some of most solidly built tubes I've bought -especially for driver tubes! These are supposed to be 10000 hours low-noise tubes, so pretty high spec.
   
  They're burning in, haven't listened to them except to confirm sound flows in both channels. Directly 7-1 strapped, as I'm pretty sure that will yield the best results. Impressions later today.
   
  Speaking of grids, while on a heptode, considering there are two control grids and different applications, we can consider that a variety of strapping methods make sense, such as the 7-1 strap. On a pentode, strapping grid 3 -not a control grid- to grid 1, with grid 2 -strapped to anode- makes little sense and bound to sound bad... Anyway, I personally would not bother testing all my pentodes in with pins 1 and 7 strapped, as I see no point in doing that.
   
  If you really want to try an interesting experiment -one that should sound good- try strapping grid 1 to the cathode on a heptode, and strapping grid 3 to socket hole 1. That way, you neutralize grid 1, and only get one control grid like in a triode. That, I'd want to see someone test, if only to see how to tie a pin to an empty socket hole -of course an adapter would be way easier.
   
  Speaking of testing, I found and bought some IBM 1680 tubes today for a petty sum of money in the US. These are basically RCA 6BE6 from 1950 sold to IBM for IBM "computers" as switching tubes, but they are in effect closer to 6BY6 tubes, as they were made so that grid 3 would have a uniform pitch and therefore sharp cutoff. So, I guess, industrial-grade RCA 6BY6 prototypes...? At least that's what I'm hoping for lol!


----------



## MIKELAP

Would material used be important for the strapping i guess copper is better than steel right .Update found some copper wire made a few straps seems to help the bass department and everything else  hmm !


----------



## mab1376

Quote: 





mikelap said:


> Would material used be important for the strapping i guess copper is better than steel right


 
   
  I would assume so. I personally use some high quality silver stuff that I found scraps of at the electronics factory I work at. Only needed about 2 inches.


----------



## gibosi

Quote: 





audiofanboy said:


> - 6BE6: grid 1 = sharp cutoff, grid 3 = remote cutoff (cutoff in triode mode when tied together *?* )
> - 6BY6: grid 1 = sharp cutoff, grid 3 = sharp cutoff (so we'd expect a sharp cutoff trait when triode strapped, probably...)
> - 6CS6: grid 1 = sharp cutoff, grid 3 = sharp cutoff (so same as above...?)


 
   
  Quote: 





audiofanboy said:


> If you really want to try an interesting experiment -one that should sound good- try strapping grid 1 to the cathode on a heptode, and strapping grid 3 to socket hole 1. That way, you neutralize grid 1, and only get one control grid like in a triode. That, I'd want to see someone test, if only to see how to tie a pin to an empty socket hole -of course an adapter would be way easier.


 
   
  Given that the 6BE6 grid 3 is remote cutoff, do you see a problem in using it as the control grid?  Maybe it would be better to tie grid 3 to the cathode? But of course, this is what strapping 2-7 accomplishes...
   
  Well, the only way to know for sure is to try.


----------



## gibosi

Quote: 





mikelap said:


> Would material used be important for the strapping i guess copper is better than steel right .Update found some copper wire made a few straps seems to help the bass department and everything else  humm !


 
   
  And again, make sure you are using stranded wire, no larger than 26 gauge. Otherwise, you risk damaging your sockets....


----------



## MIKELAP

i was using the 18 gauge stripping part on my tool ill just remove a few extra strands with my needlenose thanks for saving me the pain of possibly having to upgrade to a Littledot 4se since i would have broken my dear litledot mk3 d..........m 
	

	
	
		
		

		
			



thanks for the advice gibosi.


----------



## mordy

About wires:
   
  Cannot conjure up too much enthusiasm for exotic/fancy/expensive wires, especially for such a short run as is needed for the jumpers. IMHO the main thing is very thin stranded wires that don't enlarge the pin-outs in the socket. Looking at the pins that come out of the tubes, there is a very small contact area, and I am sure that the tube pins pushed into the socket use even less of the full contact area. Many times when one channel is dead you just have to wiggle the tube a little to make it work.
   
  My personal opinion is that fancy wires work as tone controls. I may be wrong on this point, and there are plenty of people who disagree, but nevertheless, this is my humble opinion. (Seems that the more expensive the Hi-Fi interconnects are, the better the sound...)


----------



## MIKELAP

Is there any  of you guys that had the mk3 and now have the mk4se ,is it really worth it .thanks


----------



## gibosi

Quote: 





mikelap said:


> Is there any  of you guys that had the mk3 and now have the mk4se ,is it really worth it .thanks


 
   
  I too have been thinking about buying one of these... But which one to get? And it occurs to me that since you already have all the tubes you need, maybe they would be willing to sell you a mk4se without tubes at a reduced price?


----------



## Audiofanboy

If I had to do it all over again, I'd still get an MK IV -preferably SE- but it does seem silly to be paying for those "premium" tubes, though you could easily sell them I guess.
   
  Having taken a good hard look at the PCB for both MK III and IV back when I was trying to understand how the units triode-strapped tubes, I can say that the IV has _much_ larger caps and other components, both for power and driver tubes -hence its size- which just can't be a bad thing. Considering the cash spent on tubes, I would just hate to not be sure I got the better one. MK III has obvious better value, but I'd still get the IV for its native -as in "it's made around those"- use of 6N30P tubes.
   
  If you sell the tubes, a IV SE is not that expensive really... (and gibosi, if you intend to use those $200+ -DR tubes, it would seem weird to do so on an MK III worth less than the tubes lol!)


----------



## MIKELAP

Quote: 





gibosi said:


> I too have been thinking about buying one of these... But which one to get? And it occurs to me that since you already have all the tubes you need, maybe they would be willing to sell you a mk4se without tubes at a reduced price?


 
  You read my mind the SE is $100.00 more than the regular one and it comes with the electro harmonic tubes that i just paid almost $85.00 for so whats left is it just that upgraded tubes anybody know are the electronics inside different between the regular model and the se model ? any of you guys know thank you . edited : are the internals of the 4 and the 4se are the same ?


----------



## inphu510n

mikelap said:


> You read my mind the SE is $100.00 more than the regular one and it comes with the electro harmonic tubes that i just paid almost $85.00 for so whats left is it just that upgraded tubes anybody know are the electronics inside different between the regular model and the se model ? any of you guys know thank you .




I believe the LD forum page for the MKIV states that the SE has "upgraded components in key signal path locations".


----------



## MIKELAP

saw this on a review of the mk4 se .What does this mean exactly.    Thats a while ago    you can still tube roll with the mk4 se right !
                                                                                                                                                                         *****UPDATE UPDATE UPDATE AS OF 01-11-08 UPDATE UPDATE UPDATE*****

Word from DavidZ at Little-Dot, about the MKIVse and it's default tubes:
"The WE408A is a 20V filament tube so the front driver tube voltage is modified to 6.3V for the M8100. The rear 6H30PI has a different pin-out and characteristics from the E182CC. At this point we are completely out of the E182CC vacuum tubes, and we have a few months supply of the 6H30PI left. Therefore all MK IV SE from this point on will be M8100 and 6H30PI version until we run out of 6H30PI tubes, at which point the MK IV SE will be discontinued. I hope this helps!"

So, from now on, the MKIVse will be hard wired to use the M8100 and 6H30PI tubes. When Little-Dot runs out, the "se" version is all gone. 





The MKIV and MKIVse are real power savers!!! The average power usage is only 30 watts!! 1/2 a light bulb! Love it!!!


----------



## mordy

Hi Mikelap,
   
  I am sure that electricity is cheap in Canada, but not here in New York. 1/2 a light bulb would be 6.5W - using CFLs rated at 13 W which is a 60W equivalent LOL.
   
  I asked David Zhe Zhe about the difference between the MkIII and MKIV and he seemed to indicate that the MKIII was "the sweet spot in the line." My impression was that they would sound similar (except for the upgraded tubes) and that the MKIII would be the better value. But hey, if you would sleep better knowing that you have the MKIVse, why not? (I would go for two MKIIIs though LOL)
   
  When I asked him what would be a substantial upgrade he said the MKVI amp with balanced inputs. It looks to me that it has since been discontinued, but it is still available to buy from other sources. Here is a link:
   
  http://www.ebay.com/itm/Little-Dot-MK-VI-MK6-Balanced-Headphone-Amplifier-Pre-Amplifier-Black-/110881617468?pt=US_Home_Audio_Amplifiers_Preamps&hash=item19d10f363c
   
  Thing is that I am very happy with the MKIII and personally don't feel a need to upgrade, but, who knows.....
   
  Still waiting for the final results of the excursions into the tube alphabet - which tube is going to be crowned the supertube for the MKIII?
  Then I will contact David Zhe Zhe to produce the MKIIIsi AFB version with built in socket strap switches.


----------



## mab1376

Quote: 





mordy said:


> Hi Mikelap,
> 
> I am sure that electricity is cheap in Canada, but not here in New York. 1/2 a light bulb would be 6.5W - using CFLs rated at 13 W which is a 60W equivalent LOL.
> 
> ...


 
   
  I'm looking into buying the MK VI+ which is way better for low impedance high-current cans such as the HE-500 and up. The problem with the VI+ is the price of some of the superior power tubes (5998) since it can cost $250+ for a matched quad and the 6SN7 driver tubes can get really pricy for some higher tier tubes as well.
   
  I bought the IV SE a year and a half ago and i don't use the M8100 or the 6H30PI either, i've been using all the new driver tubes with the 6N6P-IR which i believe is a superior power tube.
   
  Also the VI+ isn't discontinued, he just doesn't have any pre-built in stock.
   
   
  Quote: 





> Availability: Available with 3-4 week build time


----------



## gibosi

Quote: 





mikelap said:


> saw this on a review of the mk4 se .What does this mean exactly.    Thats a while ago    you can still tube roll with the mk4 se right !
> *****UPDATE UPDATE UPDATE AS OF 01-11-08 UPDATE UPDATE UPDATE*****
> 
> Word from DavidZ at Little-Dot, about the MKIVse and it's default tubes:
> ...


 
   
  Note that this is dated January, 2008. It appears that this configuration of the MKIVse using 408A driver tubes and E182CC power  was quite temporary. And in fact, tube rolling was very limited in that configuration. You can roll all the same tubes in the current MKIVse as you can in the MKIII. So, this old history shouldn't concern you at all. See the quote below:
   
  Quote:


orkan70 said:


> Quote:
> 
> 
> Originally Posted by *Penchum* /img/forum/go_quote.gif
> ...


----------



## Acapella11

Quote: 





audiofanboy said:


> If you really want to try an interesting experiment -one that should sound good- try strapping grid 1 to the cathode on a heptode, and strapping grid 3 to socket hole 1. That way, you neutralize grid 1, and only get one control grid like in a triode. That, I'd want to see someone test, if only to see how to tie a pin to an empty socket hole -of course an adapter would be way easier.


 
   
  Hi AFB, given grid 1 is furthered through pin1, how would you physically connect pin1 to pin2 for the cathode strap and then connect pin 7 (grid 3) to the pin1 socket hole in a way that isolates those two and considering that pin1 itself is still present? Without an adapter of course.
   
   
   
  Quote: 





> Quote:Originally Posted by *mab1376* /img/forum/go_quote.gif
> 
> I bought the IV SE a year and a half ago and i don't use the M8100 or the 6H30PI either, i've been using all the new driver tubes with the 6N6P-IR which i believe is a superior power tube.


 
   
  +1


----------



## gibosi

Quote: 





mordy said:


> Switched back to my RCA 6BY6 tubes with the 1-7 strap. Delicious, everything is there with a glorious super detailed shimmering
> high end. However, I am missing the punchy bottom end, sound stage and instrument separation of my Tung Sol 6AH6WA tubes.
> 
> 
> Right now I am listening the these wonderful heptodes - all what they are hepped up to be!


 
   
  With all the attention recently on the European heptodes, I think many in this forum are overlooking the American versions of these 6BY6 tubes. I have the RCA 5915/6BY6 and recently spent several hours with them using the 1-7 strapping. Overall, their sound is warmer, with more relative bass presence, with a bit less air, than the strapped Siemens EK90/6BE6. Further, the RCAs seem to me to be wetter and more musical than the Siemens. While I am still in love with my Siemens, I thoroughly enjoy these RCAs. Adding to Mordy's and my experience with these RCAs you also have AFB's recent positive comments regarding his Sylvania 5915/6BY6. Therefore, I encourage those of you who have not yet tried heptodes to check these out. And for those of us in North America, these American brands are easier to find and usually quite a bit cheaper to boot!


----------



## gibosi

I recently purchased what I thought were a backup pair of the Amperex E91H. After all, they were only about $8.50 for the pair, shipped, so why not? Well, they are not quite what I expected. These are "1st generation" tubes, with D-getters and a "pinched waist".
   

   
  And these are my "2nd generation" tubes with O-getters and a straight glass body.
   

   
  I cooked them for about an hour and, as near as I can tell, the sound of these older tubes is indistinguishable from the newer ones. But after all, they were manufactured only about 5 years apart, in the same Heeren, Holland, factory and they are both Premium Quality. Given that, I am extremely satisfied with them, especially for what I paid. 
   
  If you have searched for E91H/ EH900S/5915 tubes on eBay, you may have noticed, like I have, these "pinched waist" tubes from Telefunken, Valvo and others. For example:
   
  http://www.ebay.com/itm/1-Tube-Pinch-waist-Valvo-E91H-Rohre-neu-C81-/160874716544?pt=R%C3%B6hren&hash=item2574e15d80
   
  http://www.ebay.com/itm/EH900S-EH-900S-5915-TELEFUNKEN-NOS-NEW-OWN-BOX-PINCHED-WAIST-/370832212270?pt=DE_TV_Video_Audio_Elektronenr%C3%B6hren_Valves&hash=item565752812e
   
  And now that I have these, I feel quite certain that all these "pinched waist" E91H/ EH900S/5915 tubes were manufactured in the same Heeren, Holland, factory. So if you come across a good deal on a pair these, and you want a pair of these Amperex E91H, I think you can safely go for them.


----------



## bassboysam

These just arrived. Letting them burn in but i noticed a drastic difference in low end punch and overall clarity over the stock GE tubes with both my 325i and WS99.


----------



## bassboysam

Quick question, my amp seems to be running hotter than before the tube swap. Is this normal?


----------



## gibosi

Quote: 





bassboysam said:


> Quick question, my amp seems to be running hotter than before the tube swap. Is this normal?


 
   
  It has been a long time since I have used EF 95 and EF 92 tubes, so I do not remember how hot the M8161 ran. What I can say is that it is completely normal for some tubes to run hotter than others. This is likely nothing to worry about.


----------



## MIKELAP

Quote: 





gibosi said:


> It has been a long time since I have used EF 95 and EF 92 tubes, so I do not remember how hot the M8161 ran. What I can say is that it is completely normal for some tubes to run hotter than others. This is likely nothing to worry about.


 
  To keep everything cool including myself i have a little fan above the amp that helps


----------



## mordy

Getting used to the heptode 1-7 sound - sounds better and better. Looks like the bass opened up on my 6BY6 RCA's after some 40-50 hours and it became more powerful. Delicious sound...WOW!
   
  Tried running RCA 1-7 and TS 6AH6WA 2-7 at the same time. (Nothing will blow up; the amp is made with two separate sections.) In theory it works, but practically something is missing. Perhaps the lack of some kind of synergistic effect of not having both channels the same. Or in other words: A person may like ice cream and steak, but together - forget it! Have to give up on two different tubes at the same time - doesn't work.
   
  Listening to an early digital recording of light classical music on the Telearc label - remember those? One track has a bunch of cannon/rifle shots. The recording starts innocently with strings - and suddenly: BANG! Used to go into a HI-Fi store and ask them to play this track and crank up the volume. When the shots rang out the salesman would run up to the system and shut it off, thinking that the speakers blew. (As far as I know it never happened.)
   
  Unfortunately, I cannot find a recording with the cannon shots of Freikugeln by Johann Strauss on Youtube. Anyhow, the recording I have is with the Cincinnati Pops Orchestra with Erich Kunzel from 1993. (Magic Bullets Polka)
   
  For the thrill of four shots, I found this 30 second excerpt on Amazon (but MP3 does not do the recording justice):
   
  http://www.amazon.com/gp/product/B001AUMD5E/ref=dm_mu_dp_trk6
   
  Have fun!


----------



## Audiofanboy

Quote: 





acapella11 said:


> Hi AFB, given grid 1 is furthered through pin1, how would you physically connect pin1 to pin2 for the cathode strap and then connect pin 7 (grid 3) to the pin1 socket hole in a way that isolates those two and considering that pin1 itself is still present? Without an adapter of course.


 
   
_Ahah!_ Now that's a good question. Short answer is: I don't know, lol. But I do have clues -hard to actually use, but ideas nonetheless.
   
  Strapping pin 1 to pin 2 without using socket hole 1 wouldn't be too hard on tubes with fairly solid pins -pins that don't break off when bent a little- you could just bend pin 1 inwards and, I guess, solder it to pin 2 close to the glass. Ugly, cumbersome, but it _should_ work if done correctly; tube would not go very deep in the socket though but that should be OK.
   
  Linking pin 7 somehow to empty socket hole 1 is a different story. The best "idea" I could come up with, short of an adapter, would be -and it's a little risky- to use a broken off pin from another tube (clean, straight and good quality), add a small bend to it (to be able to take it out of of socket hole, otherwise it would get stuck in there the second you push it in), and insert it into socket hole 1 along with the usual pin 7-1 mod wire, and the tube itself -taking care to isolate each modded pin from the next modded pin.
   
  Yeah, it's difficult, but for just for testing purposes, I'd say it's pretty doable. Anyone willing to try lol? For the record, I have found that pins on US tubes are more solid and snap off more cleanly than on UK tubes, just my 2 cents.
   
  I can -I might actually- try it, but on the MK IV with the brass protections, it is actually harder to "get in there" with a pair of needle pliers, and manhandle a broken pin in and out of a socket hole (yes, I know you can remove the brass parts, but I don't want to, it's what makes my unit look nice lol!). Testing this mod on a socket saver -and out of the actual MK unit- first might be a better idea.
   
  Edit: _But_, that wasn't even why I came here to post today, I had two other things to mention, both I almost forgot about...
   
  First, my Telefunken EH900S. After 13h of burn-in (strapped mode), these are excellent tubes, with great but not the greatest upper end detail. They are much more forward than what I'm used to lately, and sadly seem to be -excellent but- a bit lacking in clarity below ~500 Hz, so mids and low mids sound a bit bloated; still plenty great and better than most pentodes though, the standards have shifted too much for me to keep listening to these strapped is all.
   
  Unstrapped and with grid 3 left to float away on a lonely journey away from the 4 other grids, things got much better imo. So, yes, first conclusion here -that many people had pointed out- while the strapping technique might seem "right" and seems to almost always give more detail, it doesn't always give the best sound either, and sometimes leaving grid 3 floating actually sounds more realistic. It is the case with these tubes; I got about as much upper end detail that way, better treble extension, better and larger soundstage (nothing like my strapped 5915 though!), and thinner but better and clearer mids and bass. On the floated setting, these are very very nice tubes, but I still prefer the 5915 for their boundless and speaker-like soundstage, and overall sense over "being there"; the Tele are not exactly forward when floated, but still more forward than the 5915 -like most tubes then again. Many here would love these tubes.
   
  Second, I got my "Made in Holland" E91H in the mail today. Here I was expecting O-getter Philips Heerlen E91H dual labeled with a UK military CV number, exactly like gibosi's Amperex E91H, but what I got is actually much more interesting.
   
  1960 Philips-Holland-Heerlen-made E91H with a D-getter (same getter as gibosi's Amperex 6687), un-pinched glass (at least not pinched like gibosi's though maybe not quite straight either), and dual labeled... IBM! So basically, Philips E91H dual control heptodes for IBM computers; which is funny, since I had just found and ordered old-world 1950 RCA-made 6BE6/6BY6 tubes specifically designed for... IBM as well!
   
  Anyway, I tried these strapped right away, and they sound great -unburnt-in and strapped that is, whereas reports up to here have described these as too "sweet" strapped- like a tubier and funkier 5915. More on these after 10h of burn-in tonight!


----------



## MIKELAP

Quote: 





mordy said:


> Getting used to the heptode 1-7 sound - sounds better and better. Looks like the bass opened up on my 6BY6 RCA's after some 40-50 hours and it became more powerful. Delicious sound...WOW!
> 
> Tried running RCA 1-7 and TS 6AH6WA 2-7 at the same time. (Nothing will blow up; the amp is made with two separate sections.) In theory it works, but practically something is missing. Perhaps the lack of some kind of synergistic effect of not having both channels the same. Or in other words: A person may like ice cream and steak, but together - forget it! Have to give up on two different tubes at the same time - doesn't work.
> 
> ...


 
  Regarding ice cream and steak you would have to be pregnent to like that combo i guess. ITS GOOD TO BE A MAN ! And about the cannon shots i have something simmilar they call it FOR THOSE ABOUT TO ROCK BY ACDC a classic


----------



## bassboysam

Ok another observation, i noticed that the gain switches in my MKIII have virtually no effect with the CV4015 drivers. Is that expected?



edit: nevermind, i completely forgot about the jumpers. switched them over to EF92 and everything is back to normal.


----------



## Acapella11

Quote: 





audiofanboy said:


> _Ahah!_ Now that's a good question. Short answer is: I don't know, lol. But I do have clues -hard to actually use, but ideas nonetheless.
> 
> Strapping pin 1 to pin 2 without using socket hole 1 wouldn't be too hard on tubes with fairly solid pins -pins that don't break off when bent a little- you could just bend pin 1 inwards and, I guess, solder it to pin 2 close to the glass. Ugly, cumbersome, but it _should_ work if done correctly; tube would not go very deep in the socket though but that should be OK.
> 
> ...


 
   
  Thanks Audiofanboy, I thought it would be a more complex operation. If we come up with a sort of fool proof way, I am in testing 
   
  Quote: 





> Unstrapped and with grid 3 left to float away on a lonely journey away from the 4 other grids, things got much better imo. So, yes, first conclusion here -that many people had pointed out- while the strapping technique might seem "right" and seems to almost always give more detail, it doesn't always give the best sound either, and sometimes leaving grid 3 floating actually sounds more realistic. It is the case with these tubes; I got about as much upper end detail that way, better treble extension, better and larger soundstage (nothing like my strapped 5915 though!), and thinner but better and clearer mids and bass. On the floated setting, these are very very nice tubes, but I still prefer the 5915 for their boundless and speaker-like soundstage, and overall sense over "being there"; the Tele are not exactly forward when floated, but still more forward than the 5915 -like most tubes then again. Many here would love these tubes.


 
   
  Interesting indeed. The take home message is important really. It might come in the end down to the tube, which method sounds best.
   
  Quote: 





> Second, I got my "Made in Holland" E91H in the mail today. Here I was expecting O-getter Philips Heerlen E91H dual labeled with a UK military CV number, exactly like gibosi's Amperex E91H, but what I got is actually much more interesting.


 
   
  Please, do try them 2/7-strapped =)
   
  Quote: 





mordy said:


> Getting used to the heptode 1-7 sound - sounds better and better. Looks like the bass opened up on my 6BY6 RCA's after some 40-50 hours and it became more powerful. Delicious sound...WOW!


 
   
  Welcome in heptode land =)
   
   
  Bassboysam, it is normal that EF92 tubes run hotter than EF95 tubes.


----------



## mab1376

Quote: 





> Quote:
> 
> 
> 
> ...


 
   
  I'll try this setting as well with the Amperexs.
   
  I also ordered a pair of RCA 6BY6 since I love my EH900S so much.


----------



## Nic Rhodes

could we use ECH84, ECH200 and 6JX8 here? Plenty high quality examples around.....


----------



## Audiofanboy

Quote: 





nic rhodes said:


> could we use ECH84, ECH200 and 6JX8 here? Plenty high quality examples around.....


 

 Not without some _major_ adapters, seeing as these are 9 to 10 pin triode-heptodes, so a pretty far cry from even the most exotic tubes we've managed to adapt...


----------



## bruce108

I'm following in the wake here guys, and very grateful to everyone who's done all this awesome work.
   
  Graduated from the regular pentodes to Tung-Sol 6AH6WA and thought the performance of the amp went up a whole class or two. Then came the first heptode, Telefunken EK90, and it got even better.
   
  But not till after burn-in. For the first few hours, the sound was refined, but thin and the image set well back. I had to turn the volume up 1-2 points on the dial and even then there was energy lacking. However, after only 10-12 hours they sound like different tubes, precise focus, rich sound, if anything a little too immediate. I've not known a tube change so much so quickly. I see mab is keen on these - was this your experience? I'm looking forward to trying them strapped.
   
  BTW I bought both kinds from the NOS Tube Store guy in Turkey & thought he gave good service. Good communicator, too.


----------



## mordy

Had a similar experience with the RCA 6BY6 heptodes. They sounded good, but suddenly after around 40 hours they "woke up" and the low end become much better. Wonder if others have had such experiences with heptodes?
   
  Seems that many tubes need around 20 hours of burn in, some around 50 hours, and of course the champ here is the Voskhods that need 120 hours!


----------



## MIKELAP

Quote: 





mordy said:


> Had a similar experience with the RCA 6BY6 heptodes. They sounded good, but suddenly after around 40 hours they "woke up" and the low end become much better. Wonder if others have had such experiences with heptodes?
> 
> Seems that many tubes need around 20 hours of burn in, some around 50 hours, and of course the champ here is the Voskhods that need 120 hours!


 
  Thats probably why i never liked them that much because i have maybe 10-15 hours on them if i remember correctly i found them to be harsh


----------



## mordy

Which tube are you referring to?


----------



## mordy

Which tube are you referring to?


----------



## MIKELAP

Quote: 





mordy said:


> Which tube are you referring to?


 
  Sorry about that mordy i tough you where a mind reader i am talking about the Voshkods 6ZHIP-EV/6AK5 matched pair of course GOD that was before i saw the light got to go in the EF 95 box ,no one goes into that box anymore for those tubes and while im at it i am sampling as we speak a wonderful pair of unmacthed Tung-sol 6BE6 tubes i tried on 4setting with the socket 2-7on EF95 SETTING AND ON EF95 1-7 SOCKET WIRE MOD ALSO EF 91 92 and personnally i prefer the EF95 SETTING as more balanced sound finally .


----------



## MIKELAP

i just tought i throw in a picture of my tube filing system noting more than an ice cube tray and a plastic box made for bacon slices all at your friendly neighborhood dollarstore..And on the right Accapella 11's  trusty page 77


----------



## mordy

That's funny - I also have an updated copy of p.77 next to my computer. Speaking of the 6BE6 TS tubes - did you notice any change in the sound as time goes on?


----------



## MIKELAP

Quote: 





mordy said:


> That's funny - I also have an updated copy of p.77 next to my computer. Speaking of the 6BE6 TS tubes - did you notice any change in the sound as time goes on?


 
  Of the top of my head all of the recent tubes to me sound very good the tesla 6f32v ,6cb6a ,6ah6,6ew6, 6be6,6av6, the only ones i didnt really like right off  the bat are the 6136 G.E to be honest i dont stick with a tube long enough  to see improvement sorry. But the 6BE6 sounds similar to me all those i mentionned .But it would a good idea to concentrate more on 1 pair at a time .But the thing is im like a kid i like to play more than i like to study thats my problem .


----------



## gibosi

Quote: 





bruce108 said:


> I'm following in the wake here guys, and very grateful to everyone who's done all this awesome work.
> 
> Graduated from the regular pentodes to Tung-Sol 6AH6WA and thought the performance of the amp went up a whole class or two. Then came the first heptode, Telefunken EK90, and it got even better.
> 
> But not till after burn-in. For the first few hours, the sound was refined, but thin and the image set well back. I had to turn the volume up 1-2 points on the dial and even then there was energy lacking. However, after only 10-12 hours they sound like different tubes, precise focus, rich sound, if anything a little too immediate. I've not known a tube change so much so quickly. I see mab is keen on these - was this your experience? I'm looking forward to trying them strapped.


 
   
  It's nice to hear from another set of ears! Welcome! 
   
  And after you have had some time with your strapped EK90, please let us know what you think.


----------



## bassboysam

i'm sure it has been discussed, but can someone explain "strapping"? When and how would I need to do it? I am curious about the EK90 and how it would sound.


----------



## gibosi

Quote: 





mordy said:


> Had a similar experience with the RCA 6BY6 heptodes. They sounded good, but suddenly after around 40 hours they "woke up" and the low end become much better. Wonder if others have had such experiences with heptodes?
> 
> Seems that many tubes need around 20 hours of burn in, some around 50 hours, and of course the champ here is the Voskhods that need 120 hours!


 
   
  I keep going back and forth between the RCA 5915/6BY6 and Siemens EK90. The Siemens have that airy high-end detail and dry, clean bass, which I really like, but I feel that the vocals are a bit thin. On the other hand, vocals on the RCAs sound just right, but the bass still seems a bit too wet... I am looking forward to having another 10 or 20 hours on the RCAs....
   
  Oh, and I got my first pair of 6CS6 today, a pair of Sylvanias. I picked these up for $0.99 each! And I wish I could say that I got free shipping too, but unfortunately not. lol Even so, these were still less than $8 shipped. Again, as our fearless champion of cheap tubes keep telling us, there are some good deals out there. 
   

   
  While the different printing suggests that they were manufactured at different times, otherwise, they appear to be identical. First impressions, strapped 1-7, these have the same boundless soundstage I love about the other heptodes, and they sound very promising. But recently, it seems that almost everything sounds very promising at first! lol  So need to get them burned in and spend some serious time with them....


----------



## mab1376

Quote: 





bassboysam said:


> i'm sure it has been discussed, but can someone explain "strapping"? When and how would I need to do it? I am curious about the EK90 and how it would sound.


 
   
  You just need a short bit of 26 gague stranded wire and it just connects two pins. This is to use grids what would normally be "floating" or basically having no signal passing through them.
   
  The EK90 we have started using a 7-1 strap which activates grid 3 which is designed for signaling. Without any mods it sounds very good right off the bat, but using the other grid seemingly has some pleasing results.
   
  There's some images and recommended settings per tube on page 77.


----------



## gibosi

Quote: 





bassboysam said:


> i'm sure it has been discussed, but can someone explain "strapping"? When and how would I need to do it? I am curious about the EK90 and how it would sound.


 
   
  It is a surprisingly low tech way to connect tube pins together in the socket. Check out page 77. Essentially, you will need to find some *26 gauge, or smaller, stranded wire*. Again,* stranded*, not solid, and *very thin*. Cut two small pieces, and strip the insulation off of each end, such that you can bend both of them into a U shape, and carefully insert them into your sockets, one end in pin-hole 1 and the other end in pin-hole 7. And then, carefully insert your tubes into the sockets. Thus, pin 1 and pin 7 are strapped.
   
  Again, simple, but if you have further questions, don't hesitate to ask!
   
  Oh, I see that Mab beat me to it....


----------



## hypnos1

Hi everyone,
   
  Am still loving the Siemens EK90s to death - looking forward to seeing how the TFK EK90s compare. Mab : I am so sorry you have had trouble finding some Siemens - I do hope you manage to get some soon...
  Re burn-in time - mine certainly benefited from 40+hours, which I would assume goes for other 6BE6s also...
  Re 1-7 strapping  -  loud, yes; full, yes; exciting, yes; extended/enhanced treble, yes. BUT...on first listening, some of Genesis's 'Duke' tracks (the massively 'full' numbers) - the WOW almost turned to OW! There seemed to me, anyhow, a somewhat definite loss of overall control/integration. I wonder if anyone else has noticed this to any degree with similarly full/complex(especially electronic) music. Perhaps 'reviving' #3 needs some burn-in time also?...Or do I just need to 'recalibrate' my hearing?!!!Shall have to try further similar tracks...


----------



## mab1376

Quote: 





hypnos1 said:


> Hi everyone,
> 
> Am still loving the Siemens EK90s to death - looking forward to seeing how the TFK EK90s compare. Mab : I am so sorry you have had trouble finding some Siemens - I do hope you manage to get some soon...
> Re burn-in time - mine certainly benefited from 40+hours, which I would assume goes for other 6BE6s also...
> Re 1-7 strapping  -  loud, yes; full, yes; exciting, yes; extended/enhanced treble, yes. BUT...on first listening, some of Genesis's 'Duke' tracks (the massively 'full' numbers) - the WOW almost turned to OW! There seemed to me, anyhow, a somewhat definite loss of overall control/integration. I wonder if anyone else has noticed this to any degree with similarly full/complex(especially electronic) music. Perhaps 'reviving' #3 needs some burn-in time also?...Or do I just need to 'recalibrate' my hearing?!!!Shall have to try further similar tracks...


 
   
  I actually ordered a pair from NOSTUBESTORE, the owner reached out to their depot for some more since we bought them all up.
   
  they are Haltron re-branded but Siemens under the covers.
   
  Thanks to Gibosi for tipping me off!


----------



## gibosi

Quote: 





hypnos1 said:


> Hi everyone,
> 
> Am still loving the Siemens EK90s to death - looking forward to seeing how the TFK EK90s compare. Mab : I am so sorry you have had trouble finding some Siemens - I do hope you manage to get some soon...
> Re burn-in time - mine certainly benefited from 40+hours, which I would assume goes for other 6BE6s also...
> Re 1-7 strapping  -  loud, yes; full, yes; exciting, yes; extended/enhanced treble, yes. BUT...on first listening, some of Genesis's 'Duke' tracks (the massively 'full' numbers) - the WOW almost turned to OW! There seemed to me, anyhow, a somewhat definite loss of overall control/integration. I wonder if anyone else has noticed this to any degree with similarly full/complex(especially electronic) music. Perhaps 'reviving' #3 needs some burn-in time also?...Or do I just need to 'recalibrate' my hearing?!!!Shall have to try further similar tracks...


 
   
  Do I understand correctly, that you love them in the EF 95 configuration with no 1-7 strapping? But strapped, you find them lacking? I am beginning to to think that due to the 6BE6 grid 3's remote cutoff nature, maybe the 1-7 strapping is not optimal.... I have been listening to mine strapped, but am thinking maybe I should go back to unstrapped....


----------



## gibosi

Quote: 





mab1376 said:


> I actually ordered a pair from NOSTUBESTORE, the owner reached out to their depot for some more since we bought them all up.
> 
> they are Haltron re-branded but Siemens under the covers.
> 
> Thanks to Gibosi for tipping me off!


 
  And I should say that they were able to find only 6 more tubes, three pairs, so these too may well be gone by now....


----------



## mordy

Hi Hypnos 1,
   
  Don't know about other people and their ears and hearing, but my personal experience is that it takes some time to come to a true conclusion of what sounds really good. First impressions are not always reliable.
   
  In the world of racing cars there is a saying that if an engine loses five horsepower you notice it right away, but a gain of five horsepower may be much harder to notice. So translated into tubes, some glaring deficiency stands out right away, but small improvements may escape you for a while until it becomes settled in your mind. You may love listening to a set of tubes, but over time some grating quality emerges, and it could take time to identify it.
   
  Then we have the ice cream syndrome: Strawberry, chocolate or vanilla? Everybody have their preferences, but if we can reach a consensus on which ice cream is best (6AH6, 6AU6, Heptodes etc) you can then safely pick your own flavor. And just as with ice cream the only real way of experiencing it is to taste it, so we have to try and see what suits us best.
   
  Happy tube rolling!


----------



## Acapella11

My new arrivals today:
   
  Siemens EH90 (6CS6), O-getter, mat grey plate, labelled 678 (June 1978?), on the backside it says EH90 in light grey and smaller white print FOREIGN, suppose this is original Siemens
  Russian 6A2P (10 / 1967), shiny dark grey plate, backside in white OTK 20, saucer getter
   
  I am not posting first impressions  but the Siemens 6CS6 react differently on 1/7-strapping as compared to the saucer 6BE6, more towards AFBs 5915 strap, I am guessing. This is what I use to burn them in at the moment. Further impressions later.
  
  Hypnos-1, do you also have the saucer getter type Siemens EK90 (6BE6)? If I remember correctly, you also bought from tubeshop-24. Please, check out my former post on this tube 1/7-strapped vs. non-strapped. Maybe you find similarities.
   
  Mordy, 1. chocolate, 2 vanilla, 3. strawberry! =D


----------



## GCooper

Given the bewildering number of tube rolling options available to LD owners, it might be useful to render these choices into a logic/decision tree chart for each model (and version?) that included comments from the many alpha testers on Head-Fi. I know it would make my decisions easier as to which topology and tubes I wish to audition.
   
  Anyone else interested in this?


----------



## Acapella11

Good idea, but at the moment, this is a quite complex tree and besides it is far from being finished. I would rather recommend to get yourself a small number of tubes that are highlighted in this thread and then follow it being able to compare your observations with others. That way, you would also contribute to the development of our tube rolling progress, which at the moment is quite wide but should be narrowed down over time. 
  
 The ultimate goal of course is to find a small number of high end tubes - finals, so to speak - with different signatures so that there is something for everyone.


----------



## MIKELAP

Quote: 





hypnos1 said:


> Hi everyone,
> 
> Am still loving the Siemens EK90s to death - looking forward to seeing how the TFK EK90s compare. Mab : I am so sorry you have had trouble finding some Siemens - I do hope you manage to get some soon...
> Re burn-in time - mine certainly benefited from 40+hours, which I would assume goes for other 6BE6s also...
> Re 1-7 strapping  -  loud, yes; full, yes; exciting, yes; extended/enhanced treble, yes. BUT...on first listening, some of Genesis's 'Duke' tracks (the massively 'full' numbers) - the WOW almost turned to OW! There seemed to me, anyhow, a somewhat definite loss of overall control/integration. I wonder if anyone else has noticed this to any degree with similarly full/complex(especially electronic) music. Perhaps 'reviving' #3 needs some burn-in time also?...Or do I just need to 'recalibrate' my hearing?!!!Shall have to try further similar tracks...


 
  As i commented earlier to mordy regarding 6BE6 TUNG-SOL tubes i tried ,out of the 4 settings that is possible for those tubes i found that for me the best sounding setting was the  EF 95 SETTING.


----------



## gibosi

Quote: 





gcooper said:


> Given the bewildering number of tube rolling options available to LD owners, it might be useful to render these choices into a logic/decision tree chart for each model (and version?) that included comments from the many alpha testers on Head-Fi. I know it would make my decisions easier as to which topology and tubes I wish to audition.
> 
> Anyone else interested in this?


 
  By "model (and version)", do you mean the different LD models, such as 1+, II, III and IV? If so, I doubt that this will be possible. Other than the 1+, the other models are really very, very similar. And further, I have the 1+ and so far, the tubes that are performing well on the all-tube models are also performing well on my tube-SS hybrid.
   
  My best advice is to start with a Tung Sol 6485 or Tung Sol 6AH6W. These two appear to be virtually the same tube, and both have proven to be a top performer on all LD models. As to the current heptodes, you might want to wait on the sidelines until the dust settles. We are still in the early stages of checking these out.
   
  On the other hand, if you would decide to order some of these heptodes and add your impressions, that would be great!


----------



## hypnos1

Quote: 





gibosi said:


> Do I understand correctly, that you love them in the EF 95 configuration with no 1-7 strapping? But strapped, you find them lacking? I am beginning to to think that due to the 6BE6 grid 3's remote cutoff nature, maybe the 1-7 strapping is not optimal.... I have been listening to mine strapped, but am thinking maybe I should go back to unstrapped


 
   
  Hi gibosi,
   
  Curiouser and curiouser, as Alice (in Wonderland) would say...after the initial trial with 1-7 strapping (yes, still love plain EF95 config) and my somewhat disturbing experience with those Genesis tracks, have returned to them after 15 more hours burn-in on 1-7 and...Mordy certainly is right - first impressions can be tricky. I didn't really expect to notice much difference after such a short time, but there WAS. Either my head was in a bad way the first time (which is possible given my upcoming 63rd birthday!), or that grid DID need some more time...
  Whatever, the mass of notes (too many Mr Mozart?!!) and voices seemed to have pulled together quite nicely.STRANGE...
  And I think this could be my new love (for now!) as I am getting what ACAPPELLA11 describes in his assessment of EK90s in 1-7 mode (please read his post - it is so comprehensive).
   
  So...to strap or not to strap, that is the question...mikelap prefers not? AFB prefers yes? The rest of us on the fence? A bit of a conundrum methinks...Personal preference rules, OK??...
   
  BTW A11, yes - my Siemens are the same as yours... saucer getter; sharp pins; no Siemens logo?,( and look quite different to those that do have it)...
   
  This tube rolling is a game with many twists and turns, to be sure...GRRREEAAT!
   
  BFN.


----------



## gibosi

Quote: 





hypnos1 said:


> Hi gibosi,
> 
> Curiouser and curiouser, as Alice (in Wonderland) would say...after the initial trial with 1-7 strapping (yes, still love plain EF95 config) and my somewhat disturbing experience with those Genesis tracks, have returned to them after 15 more hours burn-in on 1-7 and...Mordy certainly is right - first impressions can be tricky. I didn't really expect to notice much difference after such a short time, but there WAS. Either my head was in a bad way the first time (which is possible given my upcoming 63rd birthday!), or that grid DID need some more time...
> Whatever, the mass of notes (too many Mr Mozart?!!) and voices seemed to have pulled together quite nicely.STRANGE...
> ...


 
   
  Yes, indeed, curiouser and curiouser..lol...  And now that I know that you and A11 have the same tubes, I have to admit, I would like to be able to get a pair like yours to hear the difference. As to my Siemens EK 90, for the first hour or so in the 1-7 strap, they were indeed very different than no strapping, and I wasn't at all sure I liked them. But after a while, I ultimately "surrendered" to them, and began to think they were the best tubes I had ever heard. But now that I have been listening to them for some time, I think they are better unstrapped. For one thing, I noticed that I was shying away from complex music, in favor of simpler vocals. And then I noticed that vocals were sounding too thin, and sometimes, with certain artists, a bit "reedy." Anyway, I have put them aside for now as I am getting acquainted with the Sylvania 6CS6....
   
  Oh, and happy birthday! I also have a birthday coming up soon, in July. And of course, I am trying to decide what present(s) I should buy myself!


----------



## mab1376

I got my Lorenz EK90 today and I can say from first impression without 1-7 strap they are very similar to the Telefunken I very much like them as it without any mods.
   
  Once I get my Haltron branded Siemens I'll compare all 3 with and without the 1-7 strap.


----------



## gibosi

After having determined that my version of the Siemens EK90 sound best unstrapped, I decided to listen to the Amperex E91H again, strapped 1-7. With my recalibrated ears, I think they sound great, and I am retracting my earlier conclusion that the Amperex sound best unstrapped.
   
  To date, I have three samples of 6BE6 (GE, Siemens and Telefunken), and none of them are acceptable strapped 1-7. I have two samples of 6BY6 (RCA and Amperex), and both are excellent strapped 1-7. And I have one sample of 6CS6 (Sylvania), and it too is excellent strapped 1-7. I have a couple more 6BY6 and 6CS6 coming and will update this tally as I get to them.


----------



## mordy

In my search for replacements for the 6N6P power tubes I came across this converter that if I understand correctly converts the 6SN7 Octal tube for use in 6N6P applications. Would this be an alternative to the Little Do MKIII/IV power tubes?
   
  http://www.ebay.com/itm/two-Adapters-for-ECC32-6SN7-plug-adapters-to-instead-6N6P-tubes-/261051244115?pt=Vintage_Electronics_R2&hash=item3cc7ddde53
   
  Now, I do not understand the advantage of the 6SN7 tubes; apparently they are a dual 6J5 triode. The original Tung Sol versions sell for $100 each and (much) higher. There is even a current re-creation of the Tung Sol tube which I think is made by Sensor Corporation and selling for under $20. Other NOS brands can be had for a few dollars and up.
   
  Would appreciate the opinion of the knowledgeable members of this forum if this is something to explore.


----------



## siles1991

After reading through the previous pages Siemens & TFK's EK90's are really good? I'm planning to get some of them if anyone knows where to get some at a good price currently asking NOSTUBESTORE if they have stock.


----------



## gibosi

Quote: 





siles1991 said:


> After reading through the previous pages Siemens & TFK's EK90's are really good? I'm planning to get some of them if anyone knows where to get some at a good price currently asking NOSTUBESTORE if they have stock.


 
   
  The NOS Tube Store may still have the Telefunkens, but the Siemens are proving much harder to find. And to complicate matters, there are several versions of the Siemens out there. I have one version (with O-getters), whereas Acapella11 and hypnos1 have another version (with saucer getters). And I think there is at least one other version, which appears to be a relabeled Philips/Mullard EK90 (large squarish holes in the plates) out there as well.
   
  In case you didn't see the earlier post, when searching on eBay, notice that on the left you can choose location. Select "worldwide" as both Siemens and Telefunkens will most likely be found from European vendors.
   
  Good luck!


----------



## Acapella11

Quote: 





siles1991 said:


> After reading through the previous pages Siemens & TFK's EK90's are really good? I'm planning to get some of them if anyone knows where to get some at a good price currently asking NOSTUBESTORE if they have stock.


 

 As I am just listening to them, I can also recommend to buy the Siemens EH90 (6CS6), which are better available compared to the EK90 (6BE6) or EH900 / EH900S (6BY6). They slightly brighter, more forward with a bit less ambience compared to the saucer getter type EK90 (1/7-strap).
   
  Here is a picture of my tubes, which I got from ebay.de (http://www.ebay.de/itm/1-Stueck-EH90-Roehre-von-Siemens-nos-neu-/251035838020?ssPageName=ADME:L:OC:GB:3160)
   

   
  Different versions exist also here: with or without logo, colour of the mica and the arrangement of holes in the plate vary. All seem to have a halo getter in common.
   
  Quote: 





mordy said:


> In my search for replacements for the 6N6P power tubes I came across this converter that if I understand correctly converts the 6SN7 Octal tube for use in 6N6P applications. Would this be an alternative to the Little Do MKIII/IV power tubes?
> 
> http://www.ebay.com/itm/two-Adapters-for-ECC32-6SN7-plug-adapters-to-instead-6N6P-tubes-/261051244115?pt=Vintage_Electronics_R2&hash=item3cc7ddde53


 
   
 Great find Mordy and have a look at this thread: http://www.head-fi.org/t/479031/6sn7-tube-addicts =)
 I haven't been reading much but there is loads of info for them being great Hi-Fi tubes. One just need to overcome the threshold of $55 for the socket adapter pair incl. shipping plus $x for tubes...
 However, there is a "problem" rolling the power tubes: In a way you need to be able to compare them to other power tubes and that would be a costly maneuver with pre-1985 6H30P-DRs or 6N6P-IRs, which are less than the price of the sockets, or some 6H30P-EV in the arsenal. Everyone would of course consider, are they better than DRs? Naturally, it would be fun to test some cool power tube options.


----------



## GermanGuy

just posted a very efficient way to clean tube pins in another thread, but maybe some of the tube rolling thread members are interested in my solution, so just crossposting the link here:

 http://www.head-fi.org/t/632518/analog-paper-2-discussion-and-appreciation-thread/630#post_9573905


----------



## Acapella11

I would like to share some _initial_ impressions of a few heptodes.
  
 There is something about the Amperex E91H, a special quality that I really like. Although the treble is very slightly rolled off (more "tuby"), it has a great musicality and balance and even between heptodes it sounds that bit cleaner and has a better focus ("spooky"). 1/7 sounds fine,  At the moment, I haven't decided which strapping is the best. Mainly I am still making up my mind between 1/7 and 2/7. 1/7 and 2/7 sound louder than unstrapped, which is a small problem. Besides, 2/7 sounds opener than unstrapped, a bit more forward and brighter. 1/7 is in between.
 After some more listening, my tendency goes to 2/7 (again  ) as this removes (most of) the treble roll off and makes the tube more engaging.
  
 The Siemens EH90 would be brighter, sounding a bit more engaging if you wish, with a focus quite close but not exactly there. The EK90 (saucer getter) would be following them in terms of focus, not exactly as open sounding but with a very similar signature to the EK90. To me, so far the EH90 sounds better than the EK90, almost a brighter version of the Amperex but not quite.
  
 First impressions of the Russian 6A2P are that their focus compares with the Siemens EK90, their treble is quite nice because it is extended but round as well.
  
 The comparison was done with the 1/7-strap for all and all tubes perform on a really good level. I am going to look at them some time later again after more burn in. The Amperex was burned in most (~ 18 h), others were about 10 - 12 h.
  
  
 Edited twice: Corrected Siemens type in the 6A2P impression and Amperex differences between 1/7, 2/7 and unstrapped.


----------



## mab1376

mordy said:


> In my search for replacements for the 6N6P power tubes I came across this converter that if I understand correctly converts the 6SN7 Octal tube for use in 6N6P applications. Would this be an alternative to the Little Do MKIII/IV power tubes?
> 
> http://www.ebay.com/itm/two-Adapters-for-ECC32-6SN7-plug-adapters-to-instead-6N6P-tubes-/261051244115?pt=Vintage_Electronics_R2&hash=item3cc7ddde53
> 
> ...




 Could the little dot support the 6sn7 electrically?


----------



## gibosi

Quote: 





acapella11 said:


> Here is a picture of my tubes, which I got from ebay.de (http://www.ebay.de/itm/1-Stueck-EH90-Roehre-von-Siemens-nos-neu-/251035838020?ssPageName=ADME:L:OC:GB:3160)
> 
> 
> 
> Different versions exist also here: with or without logo, colour of the mica and the arrangement of holes in the plate vary. All seem to have a halo getter in common.


 
   
  And it is getting curiouser and curouser! I have a pair on their way to me from the same vendor. And from the picture on eBay, with the large squarish holes, I just assumed that I would getting Philips/Mullard tubes relabeled as a Siemens. Not real Siemens, but even so, I figured they would probably still be good. But the plates on yours are different. Moreover, the placement and size of  the holes resembles the plates on my Siemens EK90, which I believe were actually made by Siemens. So now I am wondering.... What I will get? lol


----------



## siles1991

NOSTUBESTORE is out of Siemens and TFK EK90's T.T I shall settle for Tung Sol 6AH6WA for now...


----------



## gibosi

Oh, I have stumbled on a way to make all our tubes sound much better! 
   
  http://news.cnet.com/8301-13645_3-57591530-47/abyss-ab-1266-headphones-run-$5495-but-theyre-worth-it/?subj=cnet&tag=title


----------



## bruce108

More money = less fun. I keep telling myself that . . .
   
  Anyway, the only things drawn to the abyss are lemmings.


----------



## mordy

Look, Steve Guttenberg is a down to earth reviewer that I trust, and I have confidence in his opinions. The Abyss headphones are out of reach price wise, but it is always interesting to read about the state of the art, and many times certain features trickle down to less expensive items.
   
  Funny, but I had in mind to write about a cheap hi-fi trick that I learned from Steve Guttenberg some 30 years ago. This isolation platform trick is so inexpensive that it just cannot be marketed (or maybe it could..).
   
  I have a sturdy hi-fi rack made out of metal with spikes. The shelves are MDF particle board and rest on four little rubber covered metal tabs. His idea was to reduce the vibration that comes from all transformers and power supplies and could muddle the sound, by placing  the shelves (or equipment) on little glass marbles to reduce the vibration.
   
  I placed four little glass marbles on the four rubber covered tabs that hold the shelf, and they allow a little bit of movement within the frame around the shelf. In addition, I used blue tack to stick three aluminum cones to the underside of the LD. The LD MKIII sits on top of the shelf, and with this set up there is ample airflow around the amp, and I have never had an issue with micro phonics or acoustic feedback with any tubes.
   
  Just make sure that the amp stays in place and doesn't roll away if you just use the marbles. I snuck out a bag of marbles from my kids, and I don't think they miss them any more since they are all grown up by now....BTW, green works best - JUST KIDDING!


----------



## bruce108

Not criticising you or Guttenberg or the Abyss. Just having fun.


----------



## mab1376

Quote: 





siles1991 said:


> NOSTUBESTORE is out of Siemens and TFK EK90's T.T I shall settle for Tung Sol 6AH6WA for now...


 
   
  The Telefunken EK90/6BE6 is also a great alternative if they still have any.


----------



## MIKELAP

Quote: 





mordy said:


> Look, Steve Guttenberg is a down to earth reviewer that I trust, and I have confidence in his opinions. The Abyss headphones are out of reach price wise, but it is always interesting to read about the state of the art, and many times certain features trickle down to less expensive items.
> 
> Funny, but I had in mind to write about a cheap hi-fi trick that I learned from Steve Guttenberg some 30 years ago. This isolation platform trick is so inexpensive that it just cannot be marketed (or maybe it could..).
> 
> ...


 
  Ya mordy its always like that regarding the marbles tisk tisk lol . Which reminds me of a story my 29 year old finally admitted to me a couple years ago some 20 years after the fact he's a wise kid and i guess the survival instinct kick in to ,that it was him that poked in my tweeter on my PRECIOUS JBL L100 what else am i going to find out about in another 20 years who knows kids.


----------



## hypnos1

Quote: 





gibosi said:


> Yes, indeed, curiouser and curiouser..lol...  And now that I know that you and A11 have the same tubes, I have to admit, I would like to be able to get a pair like yours to hear the difference. As to my Siemens EK 90, for the first hour or so in the 1-7 strap, they were indeed very different than no strapping, and I wasn't at all sure I liked them. But after a while, I ultimately "surrendered" to them, and began to think they were the best tubes I had ever heard. But now that I have been listening to them for some time, I think they are better unstrapped. For one thing, I noticed that I was shying away from complex music, in favor of simpler vocals. And then I noticed that vocals were sounding too thin, and sometimes, with certain artists, a bit "reedy." Anyway, I have put them aside for now as I am getting acquainted with the Sylvania 6CS6....
> 
> Oh, and happy birthday! I also have a birthday coming up soon, in July. And of course, I am trying to decide what present(s) I should buy myself!


 
   
  Hi gibosi.
   
  Perhaps you might treat yourself to something REALLY useful for your birthday, as I hope to - a head DESCRAMBLER/REBOOTER...to help with this rolling pastime!!! Good luck with the search. Please let me know if you succeed!
   
  Audiofanboy : A heartfelt plea to you on this topic of "to 1-7 strap EK90s, or not"...I know you did warn us re possible 'shock' on first encounter, but perhaps you should have issued a Gov't (mental) health warning!! I refer to the perceived 'wayward' control element in complex tracks, and a thinness in vocals (especially voiced by gibosi). It would appear most regulars on this forum are now shying away from said strap. The point is, after my initial doubt re overall control -  then less doubt -  my head is spinning somewhat! I am wondering if you have explored further in this particular direction yourself, and whether you can shed some of your invaluable insight on the subject...Look forward to your views AFB...
   
  Acapella 11 : The same plea to you - have you encountered these aspects in your extensive trials? Part of me wants to stay with the strap, the other wants to go - could love/hate relationships also exist in the rolling world? Certainly seems to be creeping into mine!!! Would love to hear your views also - perhaps others might too?...
   
  Got some Siemens EH90s on the way, so perhaps my mental state will improve with these on 1-7...I certainly hope so!...lol...
   
  Awaiting some Confucian wisdom with anticipation,
   
  A crazy junior headfi roller...


----------



## gibosi

Quote: 





hypnos1 said:


> Perhaps you might treat yourself to something REALLY useful for your birthday, as I hope to - a head DESCRAMBLER/REBOOTER...to help with this rolling pastime!!! Good luck with the search. Please let me know if you succeed!


 
   
  For sure, I will search Google for said device and, of course, I will let you if I am successful! lol
   
   
  Well, I got a package from Germany today, two pairs of EH90, Telefunken and Siemens.
   
  The Telefunkens, "Made in Germany" printed on the glass and the diamond between the pins. I plugged them in to make sure they are not dead and they are now burning in.
   

   
  And the Siemens...  I got one of each!!!! (>_<) At first, I thought the one on the right was actually made by Philips, but there is a circle with a number between the pins, so it appears that both of these are genuine Siemens. But still, these are not an acceptable pair. However, I don't feel that I can fault the vendor as he did send me two Siemens EH90, so I have contacted him to ask if I can purchase one more of each, to make two pair....


----------



## mordy

Hi A11,
   
  Why did you have to mention the Russian 6A2P tube? Just when I thought that we had things under control with US, British and German tubes who all have their specific sound (THIS IS A JOKE - NOT TRUE, but...) and on the edge of picking a winner or winners among the heptodes, the Russians are coming!
   
  The (alphabet) soup thickens:
   
  Russian flavor - 6A2P
   
  Italian flavor: Fivre 6BE6
   
  Hungarian flavor: Tungsram 6BE6
   
  Chechoslovakian flavor: Tesla 6H31
   
  The shakeout continues - always wanted to sample Tesla tubes, so I ordered a pair that barely squeezed under my $8 rule. However, the Tungsram and Elektronorgtecnik 6A2P should not be expensive. Could not find ANY information on this Russian factory, but so far it seems that only one factory made these heptodes.
   
  Yes, I have all my marbles, but if I am perfectly happy with the RCA 6BY6 tubes, why do I have to order more tubes? When does it end? I guess that it is human nature never to be satisfied....
   
  PS: Here is a new designation for a 6BE6 tube: Sylvania GB (Gold Brand) 1217


----------



## MIKELAP

Quote: 





mordy said:


> Hi A11,
> 
> Why did you have to mention the Russian 6A2P tube? Just when I thought that we had things under control with US, British and German tubes who all have their specific sound (THIS IS A JOKE - NOT TRUE, but...) and on the edge of picking a winner or winners among the heptodes, the Russians are coming!
> 
> ...


 
  I ordered a couple pairs of Tesla  and looking into some russians Electronorgtecnik 6a2p also there a couple a buck each thats good. And yes you have all your marbles ya but its your kidssss marbles tisk tisk


----------



## MIKELAP

Quote: 





mikelap said:


>


----------



## mordy

The Tesla tubes are from May 1957. Here is a tube chart in English:
   
  http://tubes-store.com/article_info.php?articles_id=5


----------



## MIKELAP

Quote: 





mordy said:


> The Tesla tubes are from May 1957. Here is a tube chart in English:
> 
> http://tubes-store.com/article_info.php?articles_id=5


 
  thank mordy i had that chart already from where i dont remember probably you i know i sent it to those guys when i bought the tesla 6F32v tubes a while back and the guy was happy he posted the chart .also i got a bunch of 6a2p russians for $3.00 each the Tesla just under the critical $8.00 limit Anyways should get them whithin the year lol.last time got something from Russia it took a month guy told me 2 weeks !
!


----------



## mordy

Hi Gibosi,
   
  Just received two Siemens EH90 tubes in the mail. They are exactly as the ones pictured:
   
  http://www.ebay.de/itm/1-Stueck-EH90-Roehre-von-Siemens-nos-neu-/251035838020?ssPageName=ADME:L:OC:GB:3160
   
  On the back it says: Foreign. Are these made Phillips?
   
  Just plugged them in - sound very good so far. Will reserve judgment until burnt in.


----------



## gibosi

Quote: 





mordy said:


> Just received two Siemens EH90 tubes in the mail. They are exactly as the ones pictured:
> 
> http://www.ebay.de/itm/1-Stueck-EH90-Roehre-von-Siemens-nos-neu-/251035838020?ssPageName=ADME:L:OC:GB:3160
> 
> ...


 
   
  First, look at the glass between the pins. You should see an impressed circle with an alphanumeric character. It is my understanding this marking proves these tubes were manufactured by Siemens.
   
   

   
   
  Second, the number printed below EH90 on the glass should also be on the box (271 for mine) like so:
   

   
  Assuming these numbers increased with time, it appears that the tubes with ribbed plates are earlier, as the number on my ribbed tube is 201.
   
  So I am quite sure your smooth plate Siemens are genuine, and probably manufactured later than tubes with ribbed plates.


----------



## Acapella11

Quote: 





hypnos1 said:


> Acapella 11 : The same plea to you - have you encountered these aspects in your extensive trials? Part of me wants to stay with the strap, the other wants to go - could love/hate relationships also exist in the rolling world? Certainly seems to be creeping into mine!!! Would love to hear your views also - perhaps others might too?...


 
   
 Yes, as pointed out in the former post, where I compared 1/7 and non-strapped non-authentic EK90 (saucer getter, black bottom, no alphanumeric number), there were benefits of both. Ultimately, for focus, 1/7 was better but, dependent on tube, favourite settings may vary. I consider it still work in progress. I guess, we have to hear "us through" and start to converge similarities of our impressions. Detailed descriptions of differences in sound between different straps will help.
  
 Attention 1/7-setting here: Since I brought up the *6A2P*, I would want to say that in their not perfectly burnt in state, they sound not as precise and clean as the "almost authentic" Siemens production of an EH90 (alphanumeric number: 9, but not replicated on card flap). The *Siemens* sound that I have experienced so far is relatively open and airy with a good balance and sweet enough treble. The 6A2P sound somewhat less precise, a bit wetter and with a lesser depth of stage, more "forward". As a result, each instrument appears larger in size. The tube sounds generally more forward than other tubes. There is also more wetness to the sound of the 6A2P, their treble is not as present, darker I would say and their bias is more towards the full sounding bass. With all this together, the tube still sounds quite neutral, not exactly tuby. Maybe you get a better impression now. According to my liking, I prefer the Siemens sound I heard, but I can imagine some people liking the more bassy style with a more relaxed treble (1/7-strapped).
  
 Having pointed all that out, I must add that all four settings are viable with EF91/92 being most bright, followed by 1/7. Between 2/7 and non-strapped, non-strapped is least forward. To add to the confusion, 1/7 and EF91/92 compete for the most engaging setting. Because of the bassy signature, the added treble is nice and although the bass weight is reduced, bass precision improves. In this setting, the tube "opens up" and sounds cleaner as well, although in 1/7 the bass weight itself is really quite nice. As written above, all settings have in common that the tube does not render a very deep stage.
  
 Because of the more forward character and the non ultimate resolution, this tube is probably not my overall favourite (at the moment) but it does sound different to the other heptodes I tested so far, which makes it an interesting buy.
  
 So much for now. To be fair, the strapping adds to the level of complexity and I only tried today different 6A2P straps.
  
 However none of these tubes reaches the transparency ("clean" sound) and resolution (imaging quality) of the more relaxed, somewhat tubier and not as forward sounding *Amperex E91H*, which to me (at the moment) sounds best 2/7-strapped. If this tube would be bit more neutral and engaging, that could be it. 
  
 Edit 7/7/2013: Forgot a proper recommendation: From my tubes so far, I would suggest the Amperex if you like a more relaxed sound, which becomes lesser relaxed and more engaging using the 2/7-strap, really great. It seems to me that I can indeed hear the special quality of the Amperex E91H. Otherwise the Siemens EH90 (see this post for picture) is an excellent tube.


----------



## MIKELAP

Quote: 





acapella11 said:


> Yes, as pointed out in the former post, where I compared 1/7 and non-strapped non-authentic EK90 (saucer getter, black bottom, no alphanumeric number), there were benefits of both. Ultimately, for focus, 1/7 was better but, dependent on tube, favourite settings may vary. I consider it still work in progress. I guess, we have to hear "us through" and start to converge similarities of our impressions. Detailed descriptions of differences in sound between different straps will help.
> 
> Attention 1/7-setting here: Since I brought up the *6A2P*, I would want to say that in their not perfectly burnt in state, they sound not as precise and clean as the "almost authentic" Siemens production of an EH90 (alphanumeric number: 9, but not replicated on card flap). The *Siemens* sound that I have experienced so far is relatively open and airy with a good balance and sweet enough treble. The 6A2P sound somewhat less precise, a bit wetter and with a lesser depth of stage, more "forward". As a result, each instrument appears larger in size. The tube sounds generally more forward than other tubes. There is also more wetness to the sound of the 6A2P, their treble is not as present, darker I would say and their bias is more towards the bass, which is more present and hits hard. With all this together, the tube still sounds quite neutral, not exactly tuby. Maybe you get a better impression now. According to my liking, I prefer the Siemens sound I heard, but I can imagine some people liking the more bassy style with a more relaxed treble (1/7-strapped).
> 
> ... 
  Thanks for the update Acapella11


----------



## gibosi

And I thought it might be interesting to show the "sequence number" on the older, ribbed Siemens EH90 tube and box. The number is printed on top of the tube and the box has a paper seal over the top with this number. (I open the box from the bottom.)
   

   
  I should say I was quite surprised to see this number on the tube and on the box. There are no numbers on the boxes of my other two Siemens tubes, EK90 and 5654W. That said, judging from the boxes, these EH90 appear to be older, so maybe this practice of putting the "sequence number" on the box was discontinued later.


----------



## mab1376

FYI
   
  I just did a 24 hr burn in on some EK90 tubes and the little dot maintained no problem.
   
  Doing another 24 hours on my new RCA 6BY6 tubes since they need it.


----------



## MIKELAP

Enquired today at Parts Connexion here in Canada for a socket adaptor to go from ef95 tubes to ef 91- 92 tubes to see if they would make it and how muchfor a pair but for now i use  5-7  wire mod and it works flawlesly will keep you posted.


----------



## mab1376

Quote: 





mikelap said:


> Enquired today at Parts Connexion here in Canada for a socket adaptor to go from ef95 tubes to ef 91- 92 tubes to see if they would make it and how muchfor a pair but for now i use  5-7  wire mod and it works flawlesly will keep you posted.


 
   
  If that's doable I would even consider soldering the jumper on permanently.
   
  I really hate those jumpers. 
	

	
	
		
		

		
			




   
  Also does anyone have any info if those 6SN7 adapters would work or not as a 6N6P replacement?


----------



## Acapella11

Quote: 





mab1376 said:


> Also does anyone have any info if those 6SN7 adapters would work or not as a 6N6P replacement?


 
   
  Now, that's a speculative yes. Well, simple thought. They would only design this adapter if under conditions used for 6N6P-operation also the 6SN7 could be used. Heater voltage matches and heater current is lower than for 6N6P-tubes with 0.75 A for 6N6P (0.9 A for 6N6P-I) and 0.3 A for 6SN7.
  On a positive side note, you not only add the 6SN7 but also the compatible and appreciated 6SL7 tubes to the list. The gain coefficient is 20 for 6N6P and 6SN7 but 70 (!) for 6SL7.
   
  Quote: 





mab1376 said:


> FYI
> 
> I just did a 24 hr burn in on some EK90 tubes and the little dot maintained no problem.
> 
> Doing another 24 hours on my new RCA 6BY6 tubes since they need it.


 
   
  That's the spirit! =D


----------



## mab1376

Quote: 





acapella11 said:


> Now, that's a speculative yes. Well, simple thought. They would only design this adapter if under conditions used for 6N6P-operation also the 6SN7 could be used. Heater voltage matches and heater current is lower than for 6N6P-tubes with 0.75 A for 6N6P (0.9 A for 6N6P-I) and 0.3 A for 6SN7.
> On a positive side note, you not only add the 6SN7 but also the compatible and appreciated 6SL7 tubes to the list. The gain coefficient is 20 for 6N6P and 6SN7 but 70 (!) for 6SL7.
> 
> 
> That's the spirit! =D


 
   
  Maybe in a few weeks i'll buy those adapters and a new stock set of the 6sn7 and 6sl7 to try.
   
  I plan on eventually buying the VI+ anyway which can use those tubes.


----------



## hypnos1

Quote: 





acapella11 said:


> Yes, as pointed out in the former post, where I compared 1/7 and non-strapped non-authentic EK90 (saucer getter, black bottom, no alphanumeric number), there were benefits of both. Ultimately, for focus, 1/7 was better but, dependent on tube, favourite settings may vary. I consider it still work in progress. I guess, we have to hear "us through" and start to converge similarities of our impressions. Detailed descriptions of differences in sound between different straps will help.
> 
> Attention 1/7-setting here: Since I brought up the *6A2P*, I would want to say that in their not perfectly burnt in state, they sound not as precise and clean as the "almost authentic" Siemens production of an EH90 (alphanumeric number: 9, but not replicated on card flap). The *Siemens* sound that I have experienced so far is relatively open and airy with a good balance and sweet enough treble. The 6A2P sound somewhat less precise, a bit wetter and with a lesser depth of stage, more "forward". As a result, each instrument appears larger in size. The tube sounds generally more forward than other tubes. There is also more wetness to the sound of the 6A2P, their treble is not as present, darker I would say and their bias is more towards the full sounding bass. With all this together, the tube still sounds quite neutral, not exactly tuby. Maybe you get a better impression now. According to my liking, I prefer the Siemens sound I heard, but I can imagine some people liking the more bassy style with a more relaxed treble (1/7-strapped).
> 
> ... 
   
  Hi A11,
   
  Thanks for your reply. Once again I am in awe of your ability to dissect what is entering your ears, and then describe same in such depth...are/were you in sound engineering perchance?
   
  Whatever, I feel totally inadequate! I wish I could describe in your terms what I mentioned as 'apparent loss of overall control in complex instrument (electronic) and vocal pieces', eg some Genesis/Duke tracks. Am I wide of the mark in associating this with your term 'focus?' Is what I am trying to convey rather the opposite - UNfocussed? Perhaps you can put this poor sinner on the right track to enlightenment...
   
  So much to learn, so little time...
   
  Cheers.


----------



## mordy

Always learning something new. If you already know this, just skip it.
	

	
	
		
		

		
		
	


	



   
  Many times when you buy something it states make best offer. In the past I would suggest something reasonable. If an item is $5 I would suggest $4 (works better with Euros cause a Euro is around $1.30, lol), and usually the seller would agree.
   
  Today I submitted a ridiculous offer for less than half of the price which usually results in a flat out refusal. Instead of rejecting the offer, the seller made a counter offer for 33% off, which I accepted. (The counter offer is my new experience.)
   
  So here is my thought: If the seller has a best offer feature, make a low offer and add in the message box that you are open for a counter offer. Might work better than submitting a second offer.


----------



## gibosi

Quote: 





mordy said:


> Always learning something new. If you already know this, just skip it.
> 
> 
> 
> ...


 
   
  Recently, I made a ridiculously low offer for a pair of tubes. (Primarily because the vendor was charging almost $11 to ship two tubes from Virginia to Ohio!) He rejected my offer and then blocked all communication from me, including submitting any future offers! Please forgive my language, but what a jerk! ahaha...


----------



## mordy

Something tells me that you are better off not dealing with this guy.....
   
   
  My father-in-law who was in the retail business used to say : That person you could do a good day's business without!


----------



## gibosi

Speaking of vendors, I would like to give a shout out to *haunebuvintage* on eBay:
   
  http://stores.ebay.de/haunebuvintage?_trksid=p2047675.l2563
   
  This is the vendor that sold these Siemens EH90 to Acapella11, Mordy and me. As some might remember, I received two tubes that were not a good match, even though they were both genuine Siemens tubes (post #1737). I wrote offering to purchase two more tubes, so that I would then have two slightly different pairs of these Siemens. He replied that he was sorry and that he would send these tubes to me for free. In his words, it was an "honor thing."
   
  If anyone is interested in purchasing a pair of these EH90, I recommend him. His prices and shipping charges are quite reasonable and he is a good guy.


----------



## mordy

Second that - tubes came quickly and were very well packaged. In addition, he accepted 4 Euros for each tube instead of 5.
   
  Presently burning these tubes in - have passed the 25 hr mark. It is pretty hot here, so I turned on my computer fan that I have hanging over the the LD amp to draw air from underneath the amp instead of blowing directly on it.
   
  It is a 120 mm fan and maybe overkill. The amp get so cool that it feels cold and you can touch the driver tubes that only feel lukewarm. Left it on overnight. In the late morning I listened again to the tubes and noticed that the treble sparkle was down - sounded somewhat dull.
   
  After shutting off the fan and letting the tubes warm up more they sound much better. I wonder if the vacuum tubes need a certain operating temperature to sound their best? Did not notice a difference with other tubes except for the Siemens.
   
  Anyhow, this big fan is very noisy so I am going to try a smaller fan from my PC parts bin.


----------



## Audiofanboy

Quote: 





hypnos1 said:


> Hi gibosi.
> 
> Perhaps you might treat yourself to something REALLY useful for your birthday, as I hope to - a head DESCRAMBLER/REBOOTER...to help with this rolling pastime!!! Good luck with the search. Please let me know if you succeed!
> 
> ...


 
   
  Up to here, my "conclusion" about strapping or not heptodes is pretty much a lack of conclusion, as in, no real distinguishable pattern -on 6BY6 types that is. All my heptodes sound good on either setting, some literally on both, like my E91H, and others on one or the other: strapped for my 5915, unstrapped for my Tele EH900S (not that they sounded bad strapped but just too forward present for my taste).
   
  I'm expecting another boat load of both 6BE6 and 6BY6 in the mail, so I'll be able to do some more comparing; but I do believe that the inherent difference in how both those tube types are made -remote cutoff grid 3 for 6BE6 and sharp cutoff for 6BY6- has an impact on how the tubes sound strapped (if you tie grids together that have different characteristics, you could expect that it _could _do something unexpected).
   
  I actually tried the 2-7 strap on my E91H, and didn't particularly liked how it sounded. It wasn't exactly sub-par compared to 1-7 strapped or unstrapped, but just not quite as good as either of those settings - or at least as 1-7 strapped, I didn't get a chance to compare it directly with the unstrapped setting.
   
  So, basically, the only conclusion of sorts I can reach for now is: 1-7 strap your 6BY6 types, if you find it too forward or unreal, unstrap them and be happy; use whichever you prefer with 6BE6 types, but you'll probably be happier with them unstrapped; 6CS6 are still a mystery, but should behave closer to 6BY6 types considering their grid's cutoff characteristics.


----------



## MIKELAP

Quote: 





gibosi said:


> Speaking of vendors, I would like to give a shout out to *haunebuvintage* on eBay:
> 
> http://stores.ebay.de/haunebuvintage?_trksid=p2047675.l2563
> 
> ...


 
  I see you can make offers how much is a decent offer or how much did you pay for them thanks will save me the back in forth


----------



## MIKELAP

Quote: 





mordy said:


> Second that - tubes came quickly and were very well packaged. In addition, he accepted 4 Euros for each tube instead of 5.
> 
> Presently burning these tubes in - have passed the 25 hr mark. It is pretty hot here, so I turned on my computer fan that I have hanging over the the LD amp to draw air from underneath the amp instead of blowing directly on it.
> 
> ...


 
  great just found my anwer about how much to pay for them was reading gibosi thread great .ill get a few pairs


----------



## MIKELAP

i got a problem a problem with the link to the german site for the siemens once i get there the translater  fine but when you go to the next page to the tube itself translater at top of page is not there what to do my german skills are limited any ideas   EDITED : problem solved.


----------



## mab1376

Quote: 





gibosi said:


> Recently, I made a ridiculously low offer for a pair of tubes. (Primarily because the vendor was charging almost $11 to ship two tubes from Virginia to Ohio!) He rejected my offer and then blocked all communication from me, including submitting any future offers! Please forgive my language, but what a jerk! ahaha...


 
   
  that is pretty ******-y if I do say so myself.
   
  I hate when they jack up shipping on something like we won't notice. clearly that just more profit for them, they're not fooling anyone.
   
  Whats the user account? we should boycott him!


----------



## mab1376

Quote: 





audiofanboy said:


> Up to here, my "conclusion" about strapping or not heptodes is pretty much a lack of conclusion, as in, no real distinguishable pattern -on 6BY6 types that is. All my heptodes sound good on either setting, some literally on both, like my E91H, and others on one or the other: strapped for my 5915, unstrapped for my Tele EH900S (not that they sounded bad strapped but just too forward present for my taste).
> 
> I'm expecting another boat load of both 6BE6 and 6BY6 in the mail, so I'll be able to do some more comparing; but I do believe that the inherent difference in how both those tube types are made -remote cutoff grid 3 for 6BE6 and sharp cutoff for 6BY6- has an impact on how the tubes sound strapped (if you tie grids together that have different characteristics, you could expect that it _could _do something unexpected).
> 
> ...


 
   
  I did a full 24 hours straight burn in on my RCA 6BY6 tubes and i can say they're very pleasing and very similar to the TFK EH900S, nice tubey warm sound with a good amount of detail. Great all around tube!


----------



## MIKELAP

Well just bought  myself 2 pairs of Siemens eh90's thanks for the tip mordy got them for 4 euros each. after this i am actually waiting for about 35 tubes fun fun fun. and of course they have there little house waiting for them. do i need help hmmm. Edited: got them just in time only one left.


----------



## MIKELAP

Got news regarding the socket adaptor from PCX so basically what he told me is that they would have them made in China they would have to order 50 to 100  and the price would the same as we paid for the other sockets we had made $20.00 a piece so i guess might as well inquire directly to the guys that made our other sockets and see what happens.Ill look into it.


----------



## Acapella11

Quote: 





audiofanboy said:


> So, basically, the only conclusion of sorts I can reach for now is: 1-7 strap your 6BY6 types, if you find it too forward or unreal, unstrap them and be happy; use whichever you prefer with 6BE6 types, but you'll probably be happier with them unstrapped; 6CS6 are still a mystery, but should behave closer to 6BY6 types considering their grid's cutoff characteristics.


 
   
  Hi Audiofanboy, I was kind of curious about your current point of view.
  It boils down to preference, incl. the setup your are using, and tube.
   
  What we (all of us) could do in this thread are a few generalizations of the effect of strapping / non-strapping of heptodes in EF95 setting.
  So, here are are some statements for discussion.
   
  - *Non-strapping*, Gives most relaxed sound (as in least forward) and includes most ambience as well. Should work well with every heptode.
  - *1/7*, Includes more treble bias and can reveal more detail. Depending on tube you could loose depth of stage resulting in a more forward sound. A good way to make the tube "more engaging".
  - *2/7*, This is ambiguous for me. A total no go for the Tung Sol 6BE6 (bass crazy), not too much effect for the 6A6P, quite nice with the Amperex E91H - that's just me  (more treble, more engaging, more forward).
  - *EF91/92* (= 6/7 or 5/7), so far hardly useful strap for most tubes. For 6BE6, it yields more treble but lesser ambience and overall doesn't sound balanced. Having have said that, the 6A2P I have is quite bass heavy and with not too deep stage, so this strap actually could do something good.
   
  Please respond everyone. I understand that it can take a while from now to reach final conclusion but once reached, I will add this to the table on p. 77.
   
  Quote: 





> Originally Posted by *hypnos1* /img/forum/go_quote.gif
> Hi A11,
> 
> Thanks for your reply. Once again I am in awe of your ability to dissect what is entering your ears, and then describe same in such depth...are/were you in sound engineering perchance?
> ...


 
 Thanks hypnos1, no I am not in sound engineering. I am just trying to analyze and describe what I hear. I am used to analyze and explain other matters work wise.
  
 Definition of focus from this post: *Focus* - A strong, precise sense of image projection.
  
 So, when I write focus, I mean the quality of an image rendered in my head, coming from listening. If borders and shape of heads and instruments become better defined, then focus is improved. Think of lense focus. Your "loss of control" could also include instrument separation, which again can be a result of lesser focus and a narrower stage. Difficult to say. Definitely keep writing, you will notice that your listening analysis changes as your vocabulary changes, which helps to write your experience. Of course, we all do this for the pleasure of music and sound and that is in fact the most important thing. =)


----------



## gibosi

Quote: 





mab1376 said:


> that is pretty ******-y if I do say so myself.
> 
> I hate when they jack up shipping on something like we won't notice. clearly that just more profit for them, they're not fooling anyone.
> 
> Whats the user account? we should boycott him!


 
   
  Lot of (2) Vintage TELEFUNKEN EH900S E91H Audio/Radio/Amp Vacuum Tubes
   
  http://www.ebay.com/itm/Lot-of-2-Vintage-TELEFUNKEN-EH900S-E91H-Audio-Radio-Amp-Vacuum-Tubes-/400405173654?pt=Vintage_Electronics_R2&hash=item5d3a021596
   
  And after looking at these more closely, "Made in Germany" is not printed on the tubes. And further, in the middle picture, you can see the Philips Heerlen, Holland factory code (the triangle that looks like the number 4 with the bottom cut off + 9A4) so these are, in fact, Philips/Amperex E91H, manufactured in the 4th week of January,1969, relabeled as Telefunken.
   
  In the end, I am very happy I didn't get them. ahaha... 
   
  Edit: Rather than a boycott, I think it would be a hoot if he were to receive a bunch of offers for $1 or $2 a tube.... But of course, I could never suggest that anyone actually do this!  ahaha..


----------



## bruce108

These guys appear to be scrap merchants, which I think means anything and everything, mostly metal. They're way out of whack with the tube market (esp postage) so it's possible that they simply don't know what they're doing.


----------



## Audiofanboy

Quote: 





acapella11 said:


> - *Non-strapping*, Gives most relaxed sound (as in least forward) and includes most ambience as well. Should work well with every heptode.
> - *1/7*, Includes more treble bias and can reveal more detail. Depending on tube you could loose depth of stage resulting in a more forward sound. A good way to make the tube "more engaging".
> - *2/7*, This is ambiguous for me. A total no go for the Tung Sol 6BE6 (bass crazy), not too much effect for the 6A6P, quite nice with the Amperex E91H - that's just me  (more treble, more engaging, more forward).
> - *EF91/92* (= 6/7 or 5/7), so far hardly useful strap for most tubes. For 6BE6, it yields more treble but lesser ambience and overall doesn't sound balanced. Having have said that, the 6A2P I have is quite bass heavy and with not too deep stage, so this strap actually could do something good.


 
   
  A11, nice, precise post, as usual!
   
  Let's see: I think the way you describe the "effects" -perceived and described by everyone here but obviously quite subjective- is very close to the "pattern" I hear, as far as the 1-7, 2-7 and EF92 settings go.
   
  - 1-7 always seems to yield some degree of high-end emphasis; not necessarily more treble _per se_, or more treble than unstrapped, but definitely more _perceived_ detail -usually. I personally like that setting on most 6BY6 types, though I am having the worse time making up my mind whether or not I could live with it as my permanent go-to setting.
   
  - 2-7 -which I admittedly have only tried on one pair of tubes- feels, imo, a bit more relaxed or laid-back somewhat; not by lack of focus or detail, but just by seemingly "taming" some of the rougher aspects emphasized on the 1-7 setting. An interesting setting, worth a try, but I still prefer the 1-7 or unstrapped setting up to now. Try it and help us make up our minds lol. I realize that I'm increasingly straying away from a preference for a laid-back sound and more towards clinical precision and ultra-detail with time though, so I may be biased -but aren't we all though?
   
  - Unstrapped has never sounded bad on every heptode I tried it on. At worse, like on 6BY6 tubes, it sounds a bit less high-strung than with the 1-7 mod, and more relaxed, though not always less forward (my Tele EH900S are just as forward on both settings); and at best it sounds natural and effortless, hardly a bad setting to try. Consensus does seem to be in favor of this setting for 6BE6 type tubes. I can't quite say I feel the same about ambience, though I understand exactly what you mean A11. I do feel that the sound is wetter and more "physiological" or natural, but I find I hear more "recorded ambience information" along with the extra perceived detail and soundstage with the 1-7 mod -on 6BY6 tubes.
   
  - EF92 setting has been horrific in my experience, it disgusted me of heptodes for a month... Still worth testing, if only for reference though; and you never know when you find a setting that works well for no reason , right?
   
  Quote: 





gibosi said:


> Lot of (2) Vintage TELEFUNKEN EH900S E91H Audio/Radio/Amp Vacuum Tubes
> 
> http://www.ebay.com/itm/Lot-of-2-Vintage-TELEFUNKEN-EH900S-E91H-Audio-Radio-Amp-Vacuum-Tubes-/400405173654?pt=Vintage_Electronics_R2&hash=item5d3a021596
> 
> ...


 
   
  Gibosi, if I'm not mistaken, I think you can see that the tubes are also longer than regular EH900S or 5915 special quality 6BY6 type  tubes; about as long as Heerlen E91H fact lol, so yes, I'm pretty sure these are what you think they are!
   
  I'll take this opportunity to encourage all of you to try and pick up a pair of fake-Tele labeled EH900S made by Sylvania and dual-labeled 5915, as these are still my favorite heptodes along with the E91H. Mine came in Tele boxes with military tags, Tele logos on the tubes, 5915/EH900S label, and Bundeswehr "eagle" marking. Regular US 5915 might be perfectly identical, but these should have been somewhat selected, seeing that they're rated for 10K hours and still mil-spec.


----------



## joseph69

Quote: 





acapella11 said:


> Hi Audiofanboy, I was kind of curious about your current point of view.
> It boils down to preference, incl. the setup your are using, and tube.
> 
> What we (all of us) could do in this thread are a few generalizations of the effect of strapping / non-strapping of heptodes in EF95 setting.
> ... 
  Hi, I recently purchased a LD1+ for my SR325is's. The LD came with upgraded 6AK5W Siemens tubes (I wouldn't know the difference). I find my 325is's (for my tastes) need to be more upfront and engaging and have more clarity, detail and treble. I am totally new to this tube rolling, and have never opened my LD yet or heard any other tube amp ( only SS amps). From reading this particular post I see that *STR​APPING + 1/7* opposed to *NON- STRAPPING* ( I assume) sounds like something I would definitley be interested in hearing. I would appreciate if you can tell me if I do this this with my LD1+ and with these tubes, also  what *STRAPPING *is, and correct me if I'm wrong, but I believe from some diagrams I have seen, *1/7 *refer to the pins on the tubes, which I think should be jumped together? Thank you.


----------



## jaywillin

I've been following this as well Joseph, my ms2s are supposed to get here tomorrow, if tracking is correct


----------



## gibosi

Quote: 





joseph69 said:


> Hi, I recently purchased a LD1+ for my SR325is's. The LD came with upgraded 6AK5W Siemens tubes (I wouldn't know the difference). I find my 325is's (for my tastes) need to be more upfront and engaging and have more clarity, detail and treble. I am totally new to this tube rolling, and have never opened my LD yet or heard any other tube amp ( only SS amps). From reading this particular post I see that *STR​APPING + 1/7* opposed to *NON- STRAPPING* ( I assume) sounds like something I would definitley be interested in hearing. I would appreciate if you can tell me if I do this this with my LD1+ and with these tubes, also  what *STRAPPING *is, and correct me if I'm wrong, but I believe from some diagrams I have seen, *1/7 *refer to the pins on the tubes, which I think should be jumped together? Thank you.


 
   
  Strapping is a surprisingly low tech-way to connect tube pins together in the socket. This enables us to use tubes that otherwise could not be used in LD amps. Or in the case of heptodes, with 5 internal grids, strapping allows us to explore several different configurations in our quest to obtain the best sound.
   
  I should note that your Siemens 6AK5W would *never* require strapping. Check out page 77 for more information regarding the strappings we are using for various tubes.  
   
  We are currently talking about heptodes, 6BE6, 6BY6 and 6CS6. Strapping pins 1 and 7 seems to provide good results with the 6BY6 and 6CS6, but not with the 6BE6.
   
Essentially, you will need to find some *26 gauge, or smaller, stranded wire*. Again, *stranded*, not solid, and *very thin*. Cut two small pieces, and strip the insulation off of each end, such that you can bend both of them into a U shape, and carefully insert them into your sockets, one end in pin-hole 1 and the other end in pin-hole 7. And then, carefully insert your tubes into the sockets. Thus, pin 1 and pin 7 are "strapped."
   
  Again, simple, but if you have further questions, don't hesitate to ask!


----------



## joseph69

Quote: 





jaywillin said:


> I've been following this as well Joseph, my ms2s are supposed to get here tomorrow, if tracking is correct


 
  I originally purchased the MS2i over the SR325is after reading over 500 posts on Head-fi about the MS2i, but traded them for the 325's because they were too mellow for me and I felt they didn't have that  forward Grado sound. Before purchasing the MS2i, I owned a pair of SR80i's that I unfortunately destroyed and decided to move up the chain. In the end I wound up re-purchasing the 80's and enjoy them more than my 325's, this is why I purchased the LD1+ to hear if they sound any better with a dedicated headphone amp than my Adcom GFP710 pre-amp headphone out, they don't, they sound veiled compared to my80's, out of both amps, so I want to try to roll the tubes for more clarity, space and detail (like the 80'shave at least to me). I've been on the forum for a couple of hours this afternoon listening to the LD and the 325's, then I switched to the 80's and got a refreshing blast of clarity, detail and separation (with out rolling the tubes, obviously). I'm realizing (maybe finally accepting) that I prefer the sound of the 80's over the 325's, even though they are technically superior to the 80's, and I may feel a little buyers remorse for spending the extra 200$. Please don't get me wrong the 325's and the MS2i's sound beautiful, I am not knocking them at all in any way, I just prefer the 80's, and I'm trying to turn my 325's into 80's, which I know I should not be trying to do (but I am).
  I'm not giving up on the 325's, because they are smoother and warmer than the 80's, just not as crisp, clear, detailed and upfront as the 80's, this is why I'm still interested in trying this tube set up.
  BTW, the LD1+ is a really nice little amp, just need to purchase the Schiit Magni/Modi combo to see which I prefer because I was interested in both, so I purchased the LD first due to the fact that I can change to tubes to manipulate the sound to my preference, but I do like the LD with the 80's just the way I recieved it with the upgraded Siemens 6AK5W tubes,(not that I've heard the stock tubes).
  Also this is why I'm interested in your impressions on the MS2i.


----------



## joseph69

Quote: 





gibosi said:


> Strapping is a surprisingly low tech-way to connect tube pins together in the socket. This enables us to use tubes that otherwise could not be used in LD amps. Or in the case of heptodes, with 5 internal grids, strapping allows us to explore several different configurations in our quest to obtain the best sound.
> 
> I should note that your Siemens 6AK5W would *never* require strapping. Check out page 77 for more information regarding the strappings we are using for various tubes.
> 
> ...


 
  Thank you for your reply! When you speak of (heptodes), 6BY6 and 6CS6,) is good with *1/7*, but not with 6BE6, what are (heptodes) and do I have these in this amp, what does this mean?
  So it is safe to *strap **1/7 *together on the 6AK5W tubes? Thank you.


----------



## gibosi

Quote: 





joseph69 said:


> Thank you for your reply! When you speak of (heptodes), 6BY6 and 6CS6,) is good with *1/7*, but not with 6BE6, what are (heptodes) and do I have these in this amp, what does this mean?
> So it is safe to *strap **1/7 *together on the 6AK5W tubes? Thank you.


 
   
*No* it is *not* safe to strap 1/7 with your 6AK5W.
   
  Your LD was designed to convert pentodes into triodes. Triodes have three electrodes: cathode, grid and anode. Pentodes have five electrodes: cathode, three grids and anode. So your LD straps these two extra grids internally to convert pentodes into triodes. Thus, your LD converts the 6AK5W, a pentode, into a triode. You do not have to do anything.
   
  However, there are some pentodes that have a different pin out from the 6AK5, and therefore, the LD cannot convert them into triodes. So we help the LD by strapping pins together. Once pins 2 and 7 are strapped, these other pentodes become like the 6AK5, and we can use them in the LD.
   
  Heptodes have 7 electrodes. So we have to find a away to strap the 4 extra grids, again, so the heptode becomes like a 6AK5.
   
  So, if you would like to follow along with us, I would suggest that you find some nice 6AU6 and 6AH6 (pentode) tubes. Strapping pins 2 and 7, you can then use them like a 6AK5. And you also might want to find some nice 6BE6, 6BY6 and 6CS6 (heptode) tubes. For most of the 6BE6, just plug them in like a 6AK5. You can also plug the 6BY6 and 6CS6 in like a 6AK5, but many of us think they sound better strapping pins 1 and 7.


----------



## joseph69

Quote: 





gibosi said:


> *No* it is *not* safe to strap 1/7 with your 6AK5W.
> 
> Your LD was designed to convert pentodes into triodes. Triodes have three electrodes: cathode, grid and anode. Pentodes have five electrodes: cathode, three grids and anode. So your LD straps these two extra grids internally to convert pentodes into triodes. Thus, your LD converts the 6AK5W, a pentode, into a triode. You do not have to do anything.
> 
> ...


 
  Thank you for your information, I am going to look into purchasing the tubes that you have mentioned above. I have also read that RCA-6AV6 tubes give an brighter, more upfront sound also. Being that I can purchase the 6BE6 tube and just plug them in, I will look into these first and see if any bring my 325's upfront with more clarity and detail. Thank you again for your time and guidance in my first step in tube rolling, in the mean time I will continue to read and take in what I can. Thank you again!
  Thank for the warning on *NOT *strapping *1/7 *on the LD, I may have tried this if I wasn't informed not to.


----------



## gibosi

Quote: 





joseph69 said:


> .......Please don't get me wrong the 325's and the MS2i's sound beautiful, I am not knocking them at all in any way, I just prefer the 80's, and I'm trying to turn my 325's into 80's, which I know I should not be trying to do (but I am).
> I'm not giving up on the 325's, because they are smoother and warmer than the 80's, just not as crisp, clear, detailed and upfront as the 80's, this is why I'm still interested in trying this tube set up.
> .......
> 
> Also this is why I'm interested in your impressions on the MS2i.


 
   
  While I have no experience with these headphones, perhaps there are others in this forum who might be able to suggest specific tubes that would go well with your 325s.


----------



## gibosi

Quote: 





joseph69 said:


> Thank you for your information, I am going to look into purchasing the tubes that you have mentioned above. I have also read that RCA-6AV6 tubes give an brighter, more upfront sound also.....


 
   
  If you wish to try 6AV6 / EBC91 tubes, you will need to cut off pins 5 and 6. Plus you will need to open your amp and install the EF92 jumpers. Again, page 77 is a very good summation of how to use the tubes we have tried.
   
  Happy tube rolling!


----------



## joseph69

Quote: 





gibosi said:


> While I have no experience with these headphones, perhaps there are others in this forum who might be able to suggest specific tubes that would go well with your MS2i.


 
  I no longer own the MS2i, I own the SR80i and the SR325is. I'm trying to get the upfront clarity and detail that I get with my 80's combined with the smoothness and depth of the 325's, I will continue searching the thread for anyone who has advice on tubes I may be interested in for this sound, before starting a new thread on this. Thanks for the advice.


----------



## joseph69

Quote: 





gibosi said:


> If you wish to try 6AV6 / EBC91 tubes, you will need to cut off pins 5 and 6. Plus you will need to open your amp and install the EF92 jumpers. Again, page 77 is a very good summation of how to use the tubes we have tried.
> 
> Happy tube rolling!


 
  Yes , while reading some of the current posts on this thread, I was guided to page 77, and I saved this page in my favorites. Thanks,


----------



## Acapella11

Quote: 





audiofanboy said:


> A11, nice, precise post, as usual!
> 
> Let's see: I think the way you describe the "effects" -perceived and described by everyone here but obviously quite subjective- is very close to the "pattern" I hear, as far as the 1-7, 2-7 and EF92 settings go.
> 
> ...


 
   
 The detail is appreciated AFB. I will keep the info in mind. Obviously, due to preference and gear 1/7 could be favoured over say 2/7 for 6BY6 or 6CS6 . It will be fun to be able to sum this up in the end. 
  
 Btw. I just want to report about a recent interesting experience. I have a friend interested in high end audio and he kept coming to me saying , I need to try to filter / condition my mains. I was like, "oh no just a voodoo thing". Recently, he came up and loaned me a mains filter like this. Connected to the LD and I didn't expect a thing. I was quite surprised to actually hear a difference. The sound is opener, a little more treble bias but also transparency. Bass is more defined as well, hits a bit harder. Now depending on your mains, the difference may be bigger or very small. Depending on your preference, the sound may be better or not. My conclusion is, I buy one of these.
 Currently, I am listening to the Siemens EH90 (6CS6) posted before with 2/7 strap (would you believe it  ) and it is really really good. It is worth to give this a try and since it also protects from surge, it is useful anyways.
  
 Edit: After comparing unstrapped and 2/7, I must say that although 2/7 sounds cleaner with a bit more focus, unstrapped has a better tonal balance, so it basically depends on your setup which one to use.


----------



## MIKELAP

Received my bundle of 6av6 and 6by6  from Florida today right now i got the 6by6 on theve been running for 5 hours and ive tried em strap EF95 1-7 and unstrapped ef95 with Senns hd800 and for my preference i like em unstrapped ef95 there more laid back a bit then on 1-7 i did not see what others said about these as of yet but 1-7 is not bad but maybe a little to much for me in the clean department.

   
  Regarging the 6av6 i got RCA,WESTINGHOUSE,SYLVANIA G.E. JAN.G.E   i cut the pins off today will be filing them tomorrow man im busy good thing we dont have day jobs hey mordy. But for now  6BY6  EF95 UNSTRAPPED I LIKE.


----------



## Acapella11

Quote: 





mikelap said:


> Received my bundle of 6av6 and 6by6  from Florida today right now i got the 6by6 on theve been running for 5 hours and ive tried em strap EF95 1-7 and unstrapped ef95 with Senns hd800 and for my preference i like em unstrapped ef95 there more laid back a bit then on 1-7 i did not see what others said about these as of yet but 1-7 is not bad but maybe a little to much for me in the clean department.
> 
> ...But for now  6BY6  EF95 UNSTRAPPED I LIKE.


 
   
  Just out of curiosity, how do you like 2/7?


----------



## mordy

Hi A11,
   
  I have been using a Monster A/C filter/outlet center for years and it does make a difference. The sound is cleaner with a blacker background. It stands to reason that all kinds of electrical interference from appliances, fluorescent light bulbs, cordless phones, computers, etc etc create RF noise.
   
  Another addition in combating interference is to install a dedicated line from your main fuse box to your audio equipment. In my case I try to use just one circuit for my audio but I don't really know how it is wired in my house and if a lot of other things are connected to it.
   
  As mentioned before, I found that sound improves at night when many of these interference sources are not in use.
   
  In heptode mode now - ordered some 20+ tubes to try out. 6BE6, 6CS6, 6BY6, 1680, 5750, 5915, 6H31. I am even getting a pair of Italian (designer?) tubes. The 50's advertising states as good as RCA tubes - we'll see. Did you ever hear of Fivre? Neither had I....
   
  Anybody tried the Sylvania Gold Brand 1217?
   
  Please add the tube designations 1217 , 1680 and 6H31 (all 6BE6) to your excellent chart on p.77.
   
  I use this chart every day. On my printer the green comes out fine for yes, but the orange no is hard to see - how about red?
   
  Another mystery in life: How can EBay stores that charge exorbitant prices for tubes sell any?
   
  http://www.ebay.com/itm/6BY6-Vacuum-Tubes-Lot-5-Delco-Standard-Sylvania-/400336379414?pt=LH_DefaultDomain_0&hash=item5d35e85e16
   
  I am not sure if the moose figure is included in the price....Nope, Homer the moose is not included, but at least you get free shipping.....
   
  Have fun!


----------



## Acapella11

Done.


----------



## MIKELAP

Will sample those 6av6 in a near future for impressions


----------



## MIKELAP

Quote: 





acapella11 said:


> Just out of curiosity, how do you like 2/7?


 
  Did not try this will do now will report back


----------



## MIKELAP

Quote: 





acapella11 said:


> Just out of curiosity, how do you like 2/7?


 
  Could it be possibly be better but just because i have to put the wires i would go unstrapped i did not read what you said i will after i post just to see.


----------



## mordy

Many thanks for the updated p.77


----------



## gibosi

Quote: 





mikelap said:


> Will sample those 6av6 in a near future for impressions


 
   
  Again, as I don't have the Westinghouse, I will be very curious to learn your impressions.
   
  And just for grins, I decided to listen to my black plate RCA 6AV6 this evening. Well it seems that now that I have recalibrated my ears, these RCA sound really good! The bass is tight and solid and they are not at all too bright, as I had thought before. Their most distinguishing feature, compared to the Tung-Sol 6485, is the lower vocal registers. For example, with the Tung-Sols, the vocals of Eric Clapton and Nora Jones sound just a bit fuller and thicker compared to the RCAs. However, it is not as if vocals with the RCAs sound like they are lacking anything. They are just a little different, and while I prefer the slightly fuller vocals of the Tung Sols, I also enjoy listening to the RCAs as well.


----------



## siles1991

I was wondering in the future if I would upgrade to an ALO Pan am would I be able to use the E91H tubes in it as well? Since it accepts the 6AK5/EF95 family?


----------



## gibosi

Quote: 





siles1991 said:


> I was wondering in the future if I would upgrade to an ALO Pan am would I be able to use the E91H tubes in it as well? Since it accepts the 6AK5/EF95 family?


 
   
  I would think so.... But I do not know....   Is there a dealer close to where you live? Maybe you could take your tubes with you and see if they will let you try them?
   
  Oh... And I wonder if the ALO Pan Am is really an "upgrade"? Would the Little Dot IVse be just as good? Better?


----------



## Audiofanboy

Quote: 





mikelap said:


> Will sample those 6av6 in a near future for impressions


 
   
  Nice! Finally someone else on the triode bandwagon, and with more motivation than gibosi or me, apparently lol!
   
  Curious as to how the Westinghouse sound.
   
  Btw, for those of you that _could_ be interested, I finally gathered up the courage to make a classified to sell the metric tons of extra tubes and doubles that I've accumulated over the past year:
   
  http://www.head-fi.org/t/671097/fs-tubes-for-little-dot-amps-ef95-92-91-compatible-6au6-6av6-6cb6
   
  Feel free to PM me if you find anything in there; apart from many older tube types I'd reviewed here, there are also a few recent ones like the *Lorenz EBC91* or brand new *Philips 6AT6/CV452* (Heerlen Holland factory, UK mil-spec), and a bunch of 6AU6/EF94 (Mullard) and 6AH6/6485 tubes for sale as well. Check it out!
   
  I'll be in the US -and also Quebec for a few days- over most of the summer, so if you tell me you're interested in a couple of tubes before I leave, I could take them with me and send them to the US or Canada for pennies... Just sayin'...


----------



## siles1991

double post


----------



## siles1991

Quote: 





gibosi said:


> I would think so.... But I do not know....   Is there a dealer close to where you live? Maybe you could take your tubes with you and see if they will let you try them?
> 
> Oh... And I wonder if the ALO Pan Am is really an "upgrade"? Would the Little Dot IVse be just as good? Better?


 
  well because ALO is known for their powerful amps and it comes with a DAC so I can sell my ODAC as well to give me more funds to cover the costs. The MKIV doesnt have a DAC T.T so if I sell my MKIII I still need to fork out a lot of money, should I turn it up to 10x gain?


----------



## mab1376

Quote: 





mikelap said:


> Could it be possibly be better but just because i have to put the wires i would go unstrapped i did not read what you said i will after i post just to see.


 
   
  I prefer the 6BY6 with 2-7 strap.
   
  anyone who owns the 6GX6 should try with a 2-7 strap. I'm really digging metal with this setting.
   
  Found a fan made 24/96 remaster of White Pony by Deftones and its so great with those tubes and settings! Mine are Raytheons BTW. I wanna get some RCA and Sylvania to compare.
   
  Listening the some He Is Legend now very impressed with these tubes now.


----------



## MIKELAP

Quote: 





mordy said:


> Many thanks for the updated p.77


 
  +1 on that


----------



## mordy

The first installment of my 25 heptodes arrived today. The first tubes I tried were the coveted ultra rare Italian Ferrari inspired (the boxes are Ferrari Red) FIVRE 6BE6 tubes.
   
   
  http://www.ebay.com/itm/Legendary-Rare-2A3-Tube-FIVRE-SINGLE-PLATE-Top-End-TRIODE-Valve-Own-Box-1930s-/310190242946?hash=item4838c77c82
   
   
  I AM JUST KIDDING - was looking for Fivre tubes and found the one above. Amazing that some 40 people are watching a sale of a single tube for almost $1700. One of the boxes I got had a price sticker that said 41c. I paid around $2.50/tube - 700 times less than the asking price of the tube above.
   
   
  Since I am not putting my tube on display in a museum I started burning them in on the EF95 1-7 setting. The first impression is favorable with a hefty, muscular bass similar to the TS tubes. Mids are fine, and the highs detailed and crisp. Sound stage is good with an immediacy up front presentation like you are sitting up close to the musicians.
   
   
  Going away for a few days and have to take a vacation from evaluating the tubes as well, but I will follow the blog.
   
  Happy tube rolling and have fun!


----------



## MIKELAP

Had some feed back regarding socket adaptor for EF95 EF91-92 tubes altough i did not order yet they seem ready to ship confusing (another pair)didnt get the first one anyway looks like from what there saying it should work .           this is the email in question :   
 [size=10pt]  [/size]
   Hello,

 Sorry again, we will send you another pair adapter for 6BE6/EK90 to 6AK5 * 2 , and then send you tracking number ,

 Best Regards,


----------



## Acapella11

Just a little continuation of *6CS6*-strapping: For the Siemens EH90 (see here), so far in 1/7 some focus is lost, the tubes sounds not so engaging. Unstrapped is better with good tonal balance and more ambience. 2/7 sounds most focused and quite detail rich, however it is also relatively bright and could become fatiguing. Definitely worth a try if that matches your system.
  
 Mordy, you got quite a set there with 25 tubes. Happy listening after your break!


----------



## MIKELAP

Just tried again the 6by6 unstrapped ,1-7, and 2-7 and verdict is the same i prefer with the Senns unstrapped because sound is more transparent i judge with my go to tune imo the 1-7 i did not really appreciate the bass as much as the 2 others on the 2-7 theres a xylophone pass that is not as clear as when the tube is unstrapped so unstapped as overall better sound qualitys imo.


----------



## joseph69

Hi guys, I've only posted on this thread a couple of times after recieving my first hybrid tube amp (LD1+), so I don't know much about tube rolling, but I am following this thread and trying to learn for myself, but in the meantime can anyone recommend me tubes that are directly compatible with the LD1+ ( I would like to just be able to plug these right in without any modifications to the tubes please), to use with my Grado SR325is's. What I would like as far as the sound of the tubes are:
  A very upfront, aggressive presentation with nice tight bass, crystal clear detail and crisp high frequencies.
  If anyone has experienced this type of tube signature (direct plug in) with the LD1+/SR325is, I would greatly appreciate some recommendations. Thank you.


----------



## jaywillin

Quote: 





joseph69 said:


> Hi guys, I've only posted on this thread a couple of times after recieving my first hybrid tube amp (LD1+), so I don't know much about tube rolling, but I am following this thread and trying to learn for myself, but in the meantime can anyone recommend me tubes that are directly compatible with the LD1+ ( I would like to just be able to plug these right in without any modifications to the tubes please), to use with my Grado SR325is's. What I would like as far as the sound of the tubes are:
> A very upfront, aggressive presentation with nice tight bass, crystal clear detail and crisp high frequencies.
> If anyone has experienced this type of tube signature (direct plug in) with the LD1+/SR325is, I would greatly appreciate some recommendations. Thank you.


 

 i basically have the same question, i'm using 225's and ms2's, i've had my LD1+,
  i have some siemens6ak5's, ge 408a's, hp 6ak5's,
  any suggestions would be great, in the meantime, i'll be researching and listening


----------



## gibosi

Quote: 





joseph69 said:


> Hi guys, I've only posted on this thread a couple of times after recieving my first hybrid tube amp (LD1+), so I don't know much about tube rolling, but I am following this thread and trying to learn for myself, but in the meantime can anyone recommend me tubes that are directly compatible with the LD1+ ( I would like to just be able to plug these right in without any modifications to the tubes please), to use with my Grado SR325is's. What I would like as far as the sound of the tubes are:
> A very upfront, aggressive presentation with nice tight bass, crystal clear detail and crisp high frequencies.
> If anyone has experienced this type of tube signature (direct plug in) with the LD1+/SR325is, I would greatly appreciate some recommendations. Thank you.


 
   
  When someone says that they want bright and crisp, I immediately think of triodes.  However, you do not want to use any mods...
   
  I haven't listened to any of the traditional LD tubes in a long time.... But as best as I can remember, the Voskhods might fit the bill.
   
  http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=130436695928&ssPageName=ADME:L:OC:US:3160
   
  At $3 / pair, plus $12 shipping to the US, these are very high quality tubes for not much money, so I think they might well be worth a try.


----------



## joseph69

Quote: 





gibosi said:


> When someone says that they want bright and crisp, I immediately think of triodes.  However, you do not want to use any mods...
> 
> I haven't listened to any of the traditional LD tubes in a long time.... But as best as I can remember, the Voskhods might fit the bill.
> 
> ...


 
  Thanks for helping me out again, and I will definitely buy these right now to check them out, also thanks for the link.


----------



## Audiofanboy

Quote: 





gibosi said:


> When someone says that they want bright and crisp, I immediately think of triodes.  However, you do not want to use any mods...
> 
> I haven't listened to any of the traditional LD tubes in a long time.... But as best as I can remember, the Voskhods might fit the bill.
> 
> ...


 
   
  Quote: 





joseph69 said:


> Thanks for helping me out again, and I will definitely buy these right now to check them out, also thanks for the link.


 

 Same here, crystal clear and upfront immediately makes me think of triodes. While not "natively" compatible, these aren't exactly hard to adapt (cut two pins off and protect with tapes, EF92 jumpers; more on that maybe 30 pages back or so. A 6AV6/EBC91 would fit your description very well.
   
  Of course, the old 6AK5 type Voskhods would also fit the bill... But they're actually not _that_ cheap if you only have one pair coming for Russia...
   
  Come to think of it, if you just just want to plug and play an old and native tube, the Mullard M8161 would be much better (tight tight bass, shimmering highs, those were my favorite tubes until the better and more powerful types came around).
   
  (Though I would still recommend a triode or other more recent tube type over the classic Voskhod 6ZH1P-EV and Mullard CV4015/M8161, I currently have both these tube types for sale if you're interested -link for classified a few posts back- including _burnt-in_ Voskhods, and these are pain to burn-in imo...).
   
  Actually, remembering Acapella's and my impressions, the 6EW6 type would also fit your bill quite well, and those were in the last batch of "natively compatible" tubes we'd found back 6-9 months ago. These are like the M8161, but more powerful (got a pair of those for sale too in fact; it seems I have a pair of _everything_ for sale...).


----------



## joseph69

Quote: 





audiofanboy said:


> Same here, crystal clear and upfront immediately makes me think of triodes. While not "natively" compatible, these aren't exactly hard to adapt (cut two pins off and protect with tapes, EF92 jumpers; more on that maybe 30 pages back or so. A 6AV6/EBC91 would fit your description very well.
> 
> Of course, the old 6AK5 type Voskhods would also fit the bill... But they're actually not _that_ cheap if you only have one pair coming for Russia...
> 
> ...


 
  I ordered tubes from the link the that *gibosi *posted for me last night, so I will wait until they get here and have a listen, and from there I will get in touch with you, I'm curious about the "natively compatible" tubes for right know. Thanks for letting me know that you have few different tubes for sale that may fit my needs. And thanks for the correct terminology (natively compatible), instead of using the words (direct plug in) like I did.
  BTW, I purchased my LD1+ with upgraded 6AK5W tubes, and yes I like the sound, but then again I have nothing to compare these tubes to, so thats why I would like to try some different sounding tubes, but yes they do sound nice. Thanks you.


----------



## Audiofanboy

Quote: 





joseph69 said:


> I ordered tubes from the link the that *gibosi *posted for me last night, so I will wait until they get here and have a listen, and from there I will get in touch with you, I'm curious about the "natively compatible" tubes for right know. Thanks for letting me know that you have few different tubes for sale that may fit my needs. And thanks for the correct terminology (natively compatible), instead of using the words (direct plug in) like I did.
> BTW, I purchased my LD1+ with upgraded 6AK5W tubes, and yes I like the sound, but then again I have nothing to compare these tubes to, so thats why I would like to try some different sounding tubes, but yes they do sound nice. Thanks you.


 

 Out of the olde worlde native types, the M8161 is still on the top of the pile, and fits your description perfectly. I believe it was very well rated on the first -founding- post of the thread.
   
  You might be waiting for a while before those tubes get from Russia to you though... Anywhere between 10 and 25 business days.
   
  And if you haven't read up on the first 30 pages of the thread, expect these tubes to need a burn-in time _over_ 100 hours (many have reported 120 hours, I found that the tubes settled after 105~110 hours, and I had bought these exact  tubes from the same seller btw). They are some of the best sound you can get _out of the 6AK5 family_.
   
  Have fun comparing tubes at any rate; it's addictive!


----------



## joseph69

Quote: 





audiofanboy said:


> Out of the olde worlde native types, the M8161 is still on the top of the pile, and fits your description perfectly. I believe it was very well rated on the first -founding- post of the thread.
> 
> You might be waiting for a while before those tubes get from Russia to you though... Anywhere between 10 and 25 business days.
> 
> ...


 
  I was going to ask how long it takes for tubes to burn in, but then I figured they are all different so I didn't, but glad you bought these same tubes from the same seller and let me know this. How much do you want for the Mullard M8161?


----------



## MIKELAP

Quote: 





audiofanboy said:


> Out of the olde worlde native types, the M8161 is still on the top of the pile, and fits your description perfectly. I believe it was very well rated on the first -founding- post of the thread.
> 
> You might be waiting for a while before those tubes get from Russia to you though... Anywhere between 10 and 25 business days.
> 
> ...


 
  Last time i ordered from Russia 2 months ago it took 1 month so its to bad they dont burnin on the way over.,and i ordered tubes from Bulgaria this week guy says 2 weeks for delivery dont know what he meant by that


----------



## Audiofanboy

Quote: 





joseph69 said:


> I was going to ask how long it takes for tubes to burn in, but then I figured they are all different so I didn't, but glad you bought these same tubes from the same seller and let me know this. How much do you want for the Mullard M8161?


 

 You might want to PM me if you want to discuss tube prices; I shouldn't be proselytizing here in the first place lol...
   
  Yup, different tubes, different burn-in time. The Voskhods (especially the ones you bought with gold grids and everything mil spec) are the most extreme example of burn-in time I've bumped into, along with my -also ultra mil-spec Russian- power tubes. I guess extreme tubes take extreme burn-in heh?
   
  Most tubes will take 20-50h, and you should be able to get the "pattern" after 15-20 hours max, even though they might improve further. The voskhods _will_ sound dramatically different before and after burn-in though, even I was surprised. They'll just become "good" suddenly over the last 10 hours after 100 and some hours, basically...


----------



## jaywillin

thanks for the LD1+ info guys its very much appreciated !!


----------



## Acapella11

Quote: 





joseph69 said:


> A very upfront, aggressive presentation with nice tight bass, crystal clear detail and crisp high frequencies.  A very upfront, aggressive presentation with nice tight bass, crystal clear detail and crisp high frequencies.


 
   
  Quote: 





gibosi said:


> When someone says that they want bright and crisp, I immediately think of triodes.  However, you do not want to use any mods...


 
   
  Quote: 





audiofanboy said:


> Out of the olde worlde native types, the M8161 is still on the top of the pile, and fits your description perfectly. I believe it was very well rated on the first -founding- post of the thread.


 
   
  Fully agree with gibosi and Audiofanboy there. First thing would be triodes, at least my Mullard CV417 (6AQ4) is very upfront and quite bright. Then, the M1861 = CV4015 is quite bright, not as upfront but shamelessly straight. It was my favourite before we started all the _new_ tubes. I am personally not a Voskhod fan. Although they sound good, the mids are not mine and I actually appreciated them better when they were new as they lost their sparkle after burn in. Remembering burning them in for 120 h...


----------



## Audiofanboy

Quote: 





acapella11 said:


> Fully agree with gibosi and Audiofanboy there. First thing would be triodes, at least my Mullard CV417 (6AQ4) is very upfront and quite bright. Then, the M1861 = CV4015 is quite bright, not as upfront but shamelessly straight. It was my favourite before we started all the _new_ tubes. I am personally not a Voskhod fan. Although they sound good, the mids are not mine and I actually appreciated them better when they were new as they lost their sparkle after burn in. Remembering burning them in for 120 h...


 
   
  +1 for that! I actually preferred both -very different- pairs of Voskhod tubes I had _before_ burn-in. They were spiky all right, and quite unbearable on poorly recorded albums, but they had a presence that they lost after the looong burn-in. I remember being quite disappointed about that... Like "what the **** happened to my tubes_!!!_"
   
  At one point, and since those tubes were so cheap, I almost thought about just buying a huge stash of them and only using them between 20 and 120h of use! Yeah... I was young and naive back then; now we're all rolling tubes that sound great after 20h and last up to 10k hours, that's progress for you!


----------



## gibosi

I had a few packages arrive in the mail today:
   
  1680, a special IBM version of the 6BE6, manufactured between 1949 and 1956. The third grid was changed from remote cut-off, normal for the 6BE6, to sharp cut-off. In a sense, one could see these as the prototype for the later 6BY6. As this was made by RCA (274), I will be directly comparing it to a pair of RCA 5915/6BY6. AFB first found these tubes, and as they were very cheap, decided to get a pair and see how they sound. Burning in as I type this...
   

   
  Telefunken EH900S = 5915/6BY6
   

   
  And as a number of posters have been very positive about their EK90s with saucer getters and shiny, sharp pointed pins, decided to try a pair. These were relabeled by Ultron and cheap. Those of you who have these tubes, do these look like the ones you have?


----------



## siles1991

Whats the maximum duration do you guys leave your LD MKIII up for burning in each session?


----------



## walls

I have an older LDII++ and at one point I forgot to turn it off while listening at night and found it dead the next day after work, David repaired it free of charge but I paid for shipping both ways.
   
  I learned my lesson, no more then five or six hours.
   
  Also with my WA2 the folks at WOO recommend no more then 8 hours and then let the amp cool, I believe he knows more then me about this. LOL!


----------



## MIKELAP

Quote: 





siles1991 said:


> Whats the maximum duration do you guys leave your LD MKIII up for burning in each session?


 
  Littledot recommends no more than 8 hours personally if im not there i dont take a chance you never now but i wrote this in another thread but it was all in good fun of course 








mediahound said:


> So I have a Conductor on the way. Do most just leave it on all the time? Or, do you turn it off when you are not using it?


 
 I turn it off. but i put a 100% wool blanket on hit taken from himalayan sheep from a pasture between 10 and 15000 feet of course but thats me . Or Burson says to warm it up 30 minutes before hand

Edited by MIKELAP - 7/1/13 at 12:03pm


----------



## mab1376

All depends on the tubes, the 6EW6 get pretty hot compared to the 6BY6 so I don't do more than 6 hours or so on those, with the 6BY6 and 6BE6 I've done multiple 24 hour burn-in sessions.


----------



## Acapella11

Quote: 





audiofanboy said:


> +1 for that! I actually preferred both -very different- pairs of Voskhod tubes I had _before_ burn-in. They were spiky all right, and quite unbearable on poorly recorded albums, but they had a presence that they lost after the looong burn-in. I remember being quite disappointed about that... Like "what the **** happened to my tubes_!!!_"
> 
> At one point, and since those tubes were so cheap, I almost thought about just buying a huge stash of them and only using them between 20 and 120h of use! Yeah... I was young and naive back then; now we're all rolling tubes that sound great after 20h and last up to 10k hours, that's progress for you!


 




   
  Quote: 





> Originally Posted by *gibosi* /img/forum/go_quote.gif
> 
> I had a few packages arrive in the mail today:
> 
> 1680, a special IBM version of the 6BE6, manufactured between 1949 and 1956. The third grid was changed from remote cut-off, normal for the 6BE6, to sharp cut-off. In a sense, one could see these as the prototype for the later 6BY6. As this was made by RCA (274), I will be directly comparing it to a pair of RCA 5915/6BY6. AFB first found these tubes, and as they were very cheap, decided to get a pair and see how they sound. Burning in as I type this...


 
   
  Very interesting. I am very curious about those.
   
  Quote: 





> And as a number of posters have been very positive about their EK90s with saucer getters and shiny, sharp pointed pins, decided to try a pair. These were relabeled by Ultron and cheap. Those of you who have these tubes, do these look like the ones you have?


 
   
  No, mine have a light grey plate and a black bottom without alphanumeric number. The rectangular and longer holes seem to be the same though. I've also got some Telefunken EH900S incoming. It looks like you got a great tube pair trio there!
   
  Quote: 





mikelap said:


> Littledot recommends no more than 8 hours personally if im not there i dont take a chance you never now but i wrote this in another thread but it was all in good fun of course


 
  Quote: 





mab1376 said:


> All depends on the tubes, the 6EW6 get pretty hot compared to the 6BY6 so I don't do more than 6 hours or so on those, with the 6BY6 and 6BE6 I've done multiple 24 hour burn-in sessions.


 
   
  I have also done 24 h sessions in a 20C room and with loads of space around the amp. If your place is warmer, I would probably stick to 8 h.


----------



## mordy

I have done many 24 hr plus burning in sessions, but, as stated, it depends on the type of tube. I once burned in a EF91-92 tube and the amp got so hot that I could not touch it - scary.
  Other types run much cooler. The heptodes I am trying now run very cool.
   
  For long runs I rigged up an old 12V fan from a broken computer connected to a 12V wall wart [from an on old portable phone or router ] based on the advice of members of the blog. Rather than blowing air on the tubes directly, I position the fan to suck up air from the amp and dissipate in the room. My amp is also on stilts (aluminum cones) to allow for good air circulation around the amp and heat dissipation via convection.
  At first I tried a 120 mm fan, but it lowered the temperature too much and I think it temporarily affected the performance of the driver tubes. Now I am trying a smaller 80 mm fan [from a broken power supply]. IMHO heat is a big enemy of electronics, so if you can keep the amp cool it should not break it, even if it is on much longer than 8 hours. One member of the blog lives at the edge of the Australian desert, so he may have to resort to bigger fans...
   
  Tubes change characteristics after burn in. In my experience 20-30 hours should be fine, but my RCA 6BY6 changed drastically after some 50 hours with much better bass. The Voskhods take much longer than anything else, and I burnt in two pairs for 120 hours! Grueling....
   
  PS - You can buy computer fans for just a few bucks on sale from places like Newegg and Tiger Direct in the US. (Personally, I enjoy the no cost option of looking through my parts bins...)


----------



## Audiofanboy

Even though I'm still just catching up on my heptodes (I'm amazed how fast some of you get your tubes in the mail, everything I order takes over a week to get to me... I ordered the same IBM 1680 as gibosi a whole week before him and still don't have them lol...), I finally got a few of the "6BE6 essentials".
   
  So, I have a pair of Haltron _Should-be-Siemens_ 6BE6 from the NOSTubeStore, actually labeled CV453 everywhere, and also two genuine Telefunken EK90 in Tele boxes. The "Haltmens" actually do look like most of your -assumingly genuine- Siemens EK90 with O-getters and an alphanumeric code on the base, or at least like one version of these I saw here. They look perfectly identical to the genuine Siemens EH90 I've seen here, on the other hand (the holes in the plate are close to the fold in the plate, whereas a few of your O-getter EK90 have the holes further away from the fold; my tubes have two-digit numbers inscribed in the glass at the base, and small ribs in the plate too, though the ribs don't seem as emphasized as in your pictures).
   
  Anyway, regardless of what they are (I'm still not sure what we've been calling genuine Siemens were actually made by Siemens, but who cares as long as they sound good), they sound... great, awesome, and even better than my best 6BY6 and premium variants. A natural, detailed, realistic and, above all, thoroughly engaging sound with close to perfect focus and "ambiance", as A11 puts it; these also have a more "normal" soundstage than my favorite Tele/vanias 5915/EH900S -at least compared to those 1-7 strapped- but still plenty large and expansive, just more natural; they are also less forward and have more presence than my second fav' E91H -whether or not strapped. I'm burning these in _unstrapped_ for the time being, as _everyone_ seemed to agree that yielded the best results -and I have to agree up to here!
   
  Last detail, I find these tubes -unstrapped- to not sound as "wet" or "tubey" as my other unstrapped heptodes, these are noticeably drier, _in a good way_; not that I mind a bit of tubeyness or tube echo-like wetness as it adds -often fake- ambiance, but as I mentioned recently, I do find myself straying away from a warm, cozy, or just easy sound signature, and having drier, and perhaps more challenging tubes actually works very well as far as I'm concerned -and on my gear obviously  .
   
  Mab1376, I believe you had also bought some "Haltmens" from the same source I did. Any chance you could throw in a picture of both tubes and their boxes for reference? I'll do the same as soon as I can pull them out of the amp! I'm curious as to what they _exactly_ look like, since we've been seeing quite a lot of variety in Siemens -labeled- tubes.


----------



## MIKELAP

Quote: 





acapella11 said:


> Very interesting. I am very curious about those.
> 
> 
> No, mine have a light grey plate and a black bottom without alphanumeric number. The rectangular and longer holes seem to be the same though. I've also got some Telefunken EH900S incoming. It looks like you got a great tube pair trio there!
> ...


 
  To be honest i really dont leave anything on except heating in winter once you  come close to setting the place a blaze once, not amp related mind you but still your very careful after that.


----------



## MIKELAP

Received news that my EF95 to EF91-92 socket adaptors are ready to ship so no more jumpers to change or pins to strap of course will see if they work first of course will let you guys know like last time they are $38.00 U.S. a pair + $5.00 shipping i checked there site they dont advertise them yet so we will see but these guys dont screw around if they dont work they just figure it out and send you another pair thats it so anyways will keep you posted.


----------



## Acapella11

Quote: 





audiofanboy said:


> Anyway, regardless of what they are (I'm still not sure what we've been calling genuine Siemens were actually made by Siemens, but who cares as long as they sound good), they sound... great, awesome, and even better than my best 6BY6 and premium variants. A natural, detailed, realistic and, above all, thoroughly engaging sound with close to perfect focus and "ambiance", as A11 puts it; these also have a more "normal" soundstage than my favorite Tele/vanias 5915/EH900S -at least compared to those 1-7 strapped- but still plenty large and expansive, just more natural; they are also less forward and have more presence than my second fav' E91H -whether or not strapped. I'm burning these in _unstrapped_ for the time being, as _everyone_ seemed to agree that yielded the best results -and I have to agree up to here!


 
   
  Why do you favour unstrapped to burn in?
   
  Quote:


> Anyway, regardless of what they are (I'm still not sure what we've been calling genuine Siemens were actually made by Siemens, but who cares as long as they sound good), they sound... great, awesome, and even better than my best 6BY6 and premium variants. A natural, detailed, realistic and, above all, thoroughly engaging sound with close to perfect focus and "ambiance", as A11 puts it; these also have a more "normal" soundstage than my favorite Tele/vanias 5915/EH900S -at least compared to those 1-7 strapped- but still plenty large and expansive, just more natural; they are also less forward and have more presence than my second fav' E91H -whether or not strapped.


 
   
  I actually haven't bought a "proper " halo getter Siemens EK90 yet. It seems that is one to have. Cheers, AFB.


----------



## BGRoberts

Looking forward to these.  Thanks Mikelap!
   
   
  Quote: 





mikelap said:


> Received news that my EF95 to EF91-92 socket adaptors are ready to ship so no more jumpers to change or pins to strap of course will see if they work first of course will let you guys know like last time they are $38.00 U.S. a pair + $5.00 shipping i checked there site they dont advertise them yet so we will see but these guys dont screw around if they dont work they just figure it out and send you another pair thats it so anyways will keep you posted.


----------



## MIKELAP

Off topic  but interesting, how many guitarist can you name !


----------



## GCooper

Maybe my imagination or hearing is limited, but until the dust settles on the heptode adventures, I think I will stick with the mil-spec Soviet bottles I'm using. Imaging and other characteristics are very good, at least for my listening library.
   
  There's also something emotionally satisfying about running the same Soviet tubes that I faced off against in other equipment in the 1970's.In general, Soviet military tube equipment was over-built, well designed, and stable.
   
  I have a Carver AM/FM tuner, an optical cable with a Turtle Beach Dolby surround decoder on order, and am looking forward to my Turbulent X driver-based Martin headphones later this summer. Think I'll just settle down for some listening sessions and not change anything in my audio chain for a good while.
   
  Unless someone comes up with an 01A configuration for the Little Dot Series.


----------



## mab1376

Quote: 





audiofanboy said:


> Mab1376, I believe you had also bought some "Haltmens" from the same source I did. Any chance you could throw in a picture of both tubes and their boxes for reference? I'll do the same as soon as I can pull them out of the amp! I'm curious as to what they _exactly_ look like, since we've been seeing quite a lot of variety in Siemens -labeled- tubes.


 
   
  Still waiting on them, they're probably at my post office waiting for a signature.
   
  I'll throw a pic up once i get them.


----------



## Audiofanboy

Quote: 





mab1376 said:


> Still waiting on them, they're probably at my post office waiting for a signature.
> 
> I'll throw a pic up once i get them.


 

 Great, thanks!
   
  In the meantime, here are some pics of all the heptodes I've been testing in the last weeks (including boxes when relevant):
   
  The Telefunken 5915/EH900S made by Sylvania in the US of A in 1977, aka Tele/vanias 5915, with the Bundeswehr West German military "eagle". Probably my second best tubes at this point.
   

   
  The Telefunken boxes -they look nice and genuine don't they?- with part of the military tags.
   

   
  The "real" Telefunken EH900S, actually made by Telefunken in Ulm, Germany, in 1975, and with gold pins -not that it matters.
   

   
  The -atypical- Telefunken boxes the tubes came in, just for reference.
   

   
   
  The Philips E91H, made and labeled for IBM in Heerlen, Holland, D-getter, 1960. Probably my third best tubes at this point.
   

   
  The Haltron, made by Siemens, CV453 (one tube labeled CV453, other 6BE6/CV453), aka Haltmens EK90 or Haltmens CV453, made sometime, somwhere. Note the dark getter flash, thick ribs on the plate and the holes next to the the fold on the plate (also number on the base); these look exactly like genuine Siemens _EH90_, so the probability of a Siemens origin is very high. Not that it matters anyway; these are my best tubes yet -and that's unburnt-in!
   

   
  The colorful Haltron boxes the tubes came, with CV453 labels and neither 6BE6 nor EK90.
   

   
  The _other_ -yeah, I wasn't going to run the risk of a dead tube ordering, like, the _last_ pair of Siemens EK90 in the world lol- Haltron, made by Siemens, 6BE6, aka Haltmens EK90 v2 or Haltmens 6BE6, made, yet again, sometime somewhere... Note how different these are from the other pair of Haltmens with different labels (both tubes are labeled 6BE6 and nothing else), thin ribs on the plate, more "clear" appearance and getter flash, and still the holes next to the plate fold (and still a number at the base); Siemens origin again seems like a given here. Apart from the holes close to the plate fold, these are virtually identical to the genuine Siemens EK90 seen on pics in this thread. I have yet to even test these, but I'd at least like to know which of my two pairs is the more recent production, for reference.
   

   
  The boxes the second pair of Haltmens came in, very different from the other boxes; don't these look "older"?
   

   
  And finally, the Telefunken EK90, made by Telefunken in Ulm in 1973. Untested.
   

   
  Typical Telefunken boxes these came in; smaller than my other Tele boxes though.
   

   
  Just for feedback on heptodes up to here, and different strapping techniques:
  - Tele/vanias 5915: unstrapped = excellent (natural and good ambiance, great soundstage, a bit tube-y compared to 1-7), 1-7 strapped = excellent (awesome soundstage and detail, feeling of "being there", a bit thinner than unstrapped)
  - Telefunken EH900S: unstrapped = very good, best setting (a bit forward, pretty detailed, interesting house sound), 1-7 strapped = pretty good (too forward "in your face", a bit bright and fatiguing)
  - Philips IBM E91H: unstrapped = excellent, best setting (natural and cozy signature, detailed, good soundstage), 1-7 strapped = very good (same as unstrapped but brighter and more fatiguing, less natural and a bit thin), 2-7 strapped = pretty good (less thin than 1-7, less focus than unstrapped, much I like is lost on that setting, worst out of the three)
  - Haltmens CV453 (Siemens EK90): unstrapped = glorious, best and only good setting (natural and realistic soundstage and detail, great focus and sense being there, outrageously engaging), 2-7 strapped = pretty good (almost all of what I like unstrapped disappears, more blurry, much less focus, not as natural, and also brighter and fatiguing)
   
  I'm trying to like the 2-7 setting -I really am- but I can't... I keep trying, it gives different results for each tubes, and it makes somewhat sense to "neutralize" grid 3 by cathode strapping, but it always turns out to sound worse than the two other setting -or just the basic unstrapped setting- so I think I'll stop burning up my tubes sockets with that mod, at least until a few people encourage me to try again.
   
  1-7 strap, though losing in favor for some tube type like the 6BE6, still sound great on _some_ 6BY6 tubes imo; the strapped 5915 are very very good!


----------



## mab1376

Quote: 





> I'm trying to like the 2-7 setting -I really am- but I can't... I keep trying, it gives different results for each tubes, and it makes somewhat sense to "neutralize" grid 3 by cathode strapping, but it always turns out to sound worse than the two other setting -or just the basic unstrapped setting- so I think I'll stop burning up my tubes sockets with that mod, at least until a few people encourage me to try again.
> 
> 1-7 strap, though losing in favor for some tube type like the 6BE6, still sound great on _some_ 6BY6 tubes imo; the strapped 5915 are very very good!


 
   
  I very much like the 2-7 strap on on 6GX6, 6EW6, and 6BY6.
   
  been using the RCA 6BY6 on the 1-7 strap for a few days and really liking it.


----------



## gibosi

Quote: 





audiofanboy said:


> The Telefunken 5915/EH900S made by Sylvania in the US of A in 1977, aka Tele/vanias 5915, with the Bundeswehr West German military "eagle". Probably my second best tubes at this point.
> 
> 
> 
> ...


 
   
  While the Tele/vanias seem to be very difficult to find, it is possible to find Sylvania 5915 without much trouble. And if you were to wipe the paint off, they would be identical. These appear to be 1960s vintage and I picked them up for about $10.50, including shipping, so quite affordable for those of us in North America. An extremely fine tube for not much money.


----------



## Acapella11

Quote: 





> Originally Posted by *mab1376* /img/forum/go_quote.gif
> I very much like the 2-7 strap on on 6GX6, 6EW6, and 6BY6.
> been using the RCA 6BY6 on the 1-7 strap for a few days and really liking it.


 
   
  Quote: 





audiofanboy said:


> - Telefunken EH900S: unstrapped = very good, best setting (a bit forward, pretty detailed, interesting house sound), 1-7 strapped = pretty good (too forward "in your face", a bit bright and fatiguing)


 
   
 OK, it must be that these tubes sound different even though they are from the same manufacturer. I just received my Telefunken EH900S (gold pins as well) made in Ulm. They have written "Made in Germany" on them. And what no one said so far - these are "bass monsters". More detailed descriptions have to wait. They sound initially great, interesting house sound - yes. =D
  
 The tubes slowly clear up. This needs a later update.
  
 With respect to the 2/7-strap: Every system sounds different and likes also vary. If you don't like it, it's fine, you are not obliged to use it. At least for one tube (posted earlier) I can confirm it is definitely the best of the straps in my ears.
  
 I also got some Telefunken EH90 (Ulm, Made in Germany), which straight from the box sound like a brighter (at the moment the EH900S are definitely not too bright) and more forward version of the EH900S.
  
 Edit: corrected the EH90 brand, thanks gibosi.


----------



## gibosi

Quote: 





acapella11 said:


> I also got some Siemens EH90 (Ulm, Made in Germany), which straight from the box sound like a brighter (at the moment the EH900S are definitely not too bright) and more forward version of the EH900S.


 
   
  I suspect you mean Telefunken EH90.


----------



## mab1376

Listening to the new Daft Punk Album on vinyl with my "haltmens" that just came in today.
   
  Absolutely sublime! Can't wait for my new Ortofon 2m Blue cartridge to come in this week!


----------



## gibosi

Quote: 





mab1376 said:


> Listening to the new Daft Punk Album on vinyl with my "haltmens" that just came in today.
> 
> Absolutely sublime! Can't wait for my new Ortofon 2m Blue cartridge to come in this week!


 
   
  Did you get the "Haltmens" 6BE6 in the white boxes? The CV453 in the multicolored boxes? Or something different?


----------



## bruce108

Nice pickup for someone? http://www.ebay.com/itm/4-x-6AU6A-8425A-Tube-Made-by-RCA-USA-TESTED-/110987912606?pt=R%C3%83%C2%B6hren&hash=item19d765259e


----------



## mab1376

Quote: 





gibosi said:


> Did you get the "Haltmens" 6BE6 in the white boxes? The CV453 in the multicolored boxes? Or something different?


 
   
   

   
  The 6BE6 in the white box, Haltron branded.
   
  ...and damn to they sound good with some Chili Peppers through my Ultrasone's!
   
   
  Quote: 





bruce108 said:


> Nice pickup for someone? http://www.ebay.com/itm/4-x-6AU6A-8425A-Tube-Made-by-RCA-USA-TESTED-/110987912606?pt=R%C3%83%C2%B6hren&hash=item19d765259e


 
   
  What 6AU6 brands/makes to people like? The one pair of GE 6AU6A that I Finally tested had some bad microphonics. I'd like to get another to try, I saw some pricy Sylvania and RCA tubes on ebay. Not sure why a pair pf RCA 6AU6A would go for $48, and a pair of Sylvania with gold pins for $28.


----------



## bruce108

Quote: 





> What 6AU6 brands/makes to people like? The one pair of GE 6AU6A that I Finally tested had some bad microphonics. I'd like to get another to try, I saw some pricy Sylvania and RCA tubes on ebay. Not sure why a pair pf RCA 6AU6A would go for $48, and a pair of Sylvania with gold pins for $28.


 
   
  I have Sylvania JAN 6AU6WB/WC and a pair of Mazdas on the way from NOS TubeStore. Those prices are silly: I paid $8 ea. for the Mazdas, $4 for the Sylvanias.
   
  Not even sure if I should have ordered them now that my TLF EK90s have burnt in (yes, 40-50 hours). Another heptode convert here. But I'll report back and compare them with Tung-Sol 6AH6WA.


----------



## gibosi

Quote: 





mab1376 said:


> What 6AU6 brands/makes to people like? The one pair of GE 6AU6A that I Finally tested had some bad microphonics. I'd like to get another to try, I saw some pricy Sylvania and RCA tubes on ebay. Not sure why a pair pf RCA 6AU6A would go for $48, and a pair of Sylvania with gold pins for $28.


 
   
  I would recommend both the GE and Westinghouse 8425/6AU6. Also, I believe that link above for "4 x 6AU6A (=8425A) Tube Made by RCA (USA). TESTED" is misleading. These are not 8425A. They are just standard 6AU6A tubes, nothing special. To my knowledge, RCA did not manufacture 8425 tubes. However, they did manufacture a premium 6136 (Command) tube. Their Command series tubes are similar in quality to the Sylvania Gold Brand 6136.


----------



## Audiofanboy

Quote: 





mab1376 said:


> The 6BE6 in the white box, Haltron branded.
> 
> ...and damn to they sound good with some Chili Peppers through my Ultrasone's!
> 
> ...


 
   
  Glad to hear you like the Haltmens!
   
  As for good 6AU6 tubes, I found that the Mullard Blackburn made EF94 were also very nice. Different and warmer (more "English-sounding" as silly as it sounds) than the good American brands and definitely high grade tubes; very nice for people that like a bit of tubeyness. Otherwise, the 8425A tubes are the best American 6AU6 I've tested. From what I read, 6AU6 are actually known for being prone to microphonics, among which many American brands (I'm not saying it, Google is), hence the hard to find low-noise US 7543 tube. As gibosi said, 6136 tubes were also made pretty high-spec compared to consumer level 6AU6 tubes.
   
  Of course, then there's the whole world of 6AH6/6485 tubes too...


----------



## MIKELAP

Ive been burning in my G.E 6av6 they have maybe 6 hours ont them compared to the 6av6 HitRay's that have maybe 15 hours  with the Senns and the same tune as always and to the best of my knowledge the Hit Ray's are bassier (you got to remember its the kind of bass you get with Senns not Denons) but with a little less treble and the G.E. have less bass a bit more treble soundstage is more or less the same there is not big difference between them as a matter of fact i had to switch them several times to see a difference if you guys have impressions i would like to here them also probably with  more burnin they will change i guess.other 6av6 impressions to come.EDIT: MADE A  MISTAKE WAS BURNIG IN G.E. TUBES NOT WESTINGHOUSE SORRY.


----------



## gibosi

Quote: 





mikelap said:


> Ive been burning in my Westinghouse 6av6 they have maybe 6 hours ont them compared to the 6av6 HitRay's that have maybe 15 hours  with the Senns and the same tune as always and to the best of my knowledge the Hit Ray's are bassier (you got to remember its the kind of bass you get with Senns not Denons) but with a little less treble and the Westinghouse have less bass a bit more treble soundstage is more or less the same there is not big difference between them as a matter of fact i had to switch them several times to see a difference if you guys have impressions i would like to here them also probably with  more burnin they will change i guess.other 6av6 impressions to come.


 
   
  This is good to know. However, I have not heard the Westinghouse or the Hit Ray, so I will wait for your impressions of the RCA, Sylvania and GE to learn more.


----------



## MIKELAP

Quote: 





gibosi said:


> This is good to know. However, I have not heard the Westinghouse or the Hit Ray, so I will wait for your impressions of the RCA, Sylvania and GE to learn more.


 
   
   
  Quote: 





gibosi said:


> This is good to know. However, I have not heard the Westinghouse or the Hit Ray, so I will wait for your impressions of the RCA, Sylvania and GE to learn more.


 
  Well sorry guys but i made a mistake i was actually burning in G.E. NOT WESTINGHOUSE lettering is kind of erased sorry for the mix up will edit post.


----------



## Acapella11

Quote: 





audiofanboy said:


> I'm trying to like the 2-7 setting -I really am- but I can't... I keep trying, it gives different results for each tubes, and it makes somewhat sense to "neutralize" grid 3 by cathode strapping, but it always turns out to sound worse than the two other setting -or just the basic unstrapped setting-


 
   
 I have listened to Telefunken EH900S (E91H), EH90, Siemens EH90, EK90 and Amperex E91H and to be fair, these results do not superimpose with mine. In every case 2/7 is a viable option depending on favour. Specifically for the E91H tubes because they are very focused but they are also not exactly engaging. The 2/7-strap yields more treble bias and make them sound more interesting. For my Siemens EK90 (not authentic probably, with black bottom) the 2/7 sounds between 1/7 and unstrapped, which can sound very nice actually. I agree that unstrapped sounds very good. It also does on these Siemens.
  
 Quote:


> so I think I'll stop burning up my tubes sockets with that mod, at least until a few people encourage me to try again.
> 1-7 strap, though losing in favor for some tube type like the 6BE6, still sound great on _some_ 6BY6 tubes imo; the strapped 5915 are very very good! 
  
 My purpose is not to encourage you. Do what you please as you are listening to your setup and I am listening to mine. If you don't like it on yours but I like it on mine, I wouldn't just switch and you wouldn't neither.
  
 Btw original Siemens EK90 are kind of impossible to get, which makes it for most people impossible to follow this conversation. However, I encourage to buy the non-original ones also. Mine are good.


----------



## gibosi

Quote: 





acapella11 said:


> Btw original Siemens EK90 are kind of impossible to get, which makes it for most people impossible to follow this conversation. However, I encourage to buy the non-original ones also. Mine are good.


 
   
  The picture for the following listing isn't all that good, but would you guess these Siemens EK90 are the same as yours? They appear to have saucer getters and sharp, pointed plated pins....
   
  http://www.ebay.com/itm/1-Stuck-EK90-Siemens-Rohre-Neu-nos-/261193494785?pt=DE_TV_Video_Audio_Elektronenr%C3%83%C2%B6hren_Valves&hash=item3cd0587101


----------



## Acapella11

Quote: 





> Originally Posted by *gibosi* /img/forum/go_quote.gif
> 
> The picture for the following listing isn't all that good, but would you guess these Siemens EK90 are the same as yours? They appear to have saucer getters and sharp, pointed plated pins....
> 
> http://www.ebay.com/itm/1-Stuck-EK90-Siemens-Rohre-Neu-nos-/261193494785?pt=DE_TV_Video_Audio_Elektronenr%C3%83%C2%B6hren_Valves&hash=item3cd0587101


 
   
  They are not because mine have a black bottom and no logo. Mine also came in a white box, which has on the following text:
  5960-12-124-5244
  Elektronenroehre
  EK90
  1EA
  4/78
  D/8502/82106
  Siemens AG Muenchen 80
   
  The fact that there is no German "ö" but "oe" instead points further to not one of the regular German productions.
   
  The one one the picture looks "more original", if there is a gradient, than mine. Unfortunately it is only 1.


----------



## gibosi

Quote: 





acapella11 said:


> OK, it must be that these tubes sound different even though they are from the same manufacturer. I just received my Telefunken EH900S (gold pins as well) made in Ulm. They have written "Made in Germany" on them. And what no one said so far - these are "bass monsters". More detailed descriptions have to wait. They sound initially great, interesting house sound - yes. =D
> 
> The tubes slowly clear up. This needs a later update.
> 
> With respect to the 2/7-strap: Every system sounds different and likes also vary. If you don't like it, it's fine, you are not obliged to use it. At least for one tube (posted earlier) I can confirm it is definitely the best of the straps in my ears. 
   
  I just put my Telefunken EH900S in to burn, and yes, they are "bass monsters"! 
   
  Mine do not have gold pins, but otherwise, they look the same, "Made in Germany" printed on the glass with a diamond impressed between the pins. Moreover, the boxes are the same style as are AFB's.
   
  A few words regarding my current thinking about these heptodes. With the pentodes and triodes we have trialed in the past, we simply put them in and listened. But with the heptodes, every tube is now essentially THREE tubes. (Well actually FOUR, but I think no one tests them in the EF92 setting anymore.)
   
  In my experience trying to compare more than two, or at most three, tubes can be stressful to the point of being a rather painful ordeal. For example, my head hurts just thinking of MIKELAP comparing FIVE different triodes! But with heptodes, comparing only two tubes is actually more like comparing SIX tubes!
   
  I write this to emphasize that it is going to take much more time than usual to sort through all these heptodes. I personally have 8 pairs of 6BE6, 5 pairs of 6BY6, and 4 pairs of 6CS6. Let's see..... 17 tubes times 3 different strappings.... 51 possibilities?  I find this to be simply overwhelming!!  And I suspect that I simply won't bother testing every possible strapping for every tube... 
   
In the end, we may not be able to reach a consensus regarding which strapping is best for each tube. But eventually, I think we will arrive at some consensus regarding which tubes are even worth the bother to explore multiple strappings. And I believe that alone will be a significant accomplishment....


----------



## gibosi

Quote: 





acapella11 said:


> They are not because mine have a black bottom and no logo.
> 
> The one one the picture looks "more original", if there is a gradient, than mine. Unfortunately it is only 1.


 
   
  I was hoping these were like yours as these are the only Siemens EK90 that I have been able to find. However, as much as I would like to know how they sound, I think I already have way too many heptodes, so I hope someone else will grab a pair of these and tell us how they sound. 
   
  Edit: Oh, you are right.... only one tube available...


----------



## mordy

Found another Siemens EK90 tube for sale. Could be that the seller has more than one. This one, as well as the other one above, are listed as "make offer" as well. Based on the pictures they look very similar.
   
  And based on my experience with EBay, if you have patience, more "impossible to find tubes" will turn up for sale.
   
   
  http://www.ebay.com/itm/EK-90-Siemens-Neu-aus-altem-Bestand-OVP-EK-90-Siemens-NOS-own-box-/230854435741?pt=DE_TV_Video_Audio_Elektronenr%C3%B6hren_Valves&hash=item35bfff239d


----------



## mab1376

The "Haltmens" sound great on the HD650 with the 7-1, since they're so dark it brightens them up wonderfully.


----------



## gibosi

Quote: 





acapella11 said:


> They are not because mine have a black bottom and no logo. Mine also came in a white box, which has on the following text:


 
   
  Black bottom...  Maybe these (not including the logo/printing) look like yours? 
   
  http://www.ebay.com/itm/6BE6-CV453-EK90-miniature-heptode-electron-tube-valve-/390260740216?hash=item5add5a5078


----------



## zedmeco

EK90 Röhre tubes (6BE6) Siemens. Hi, I have two pairs of these tubes that I bought some time ago but they do not seem to work with my little dot mk3, baically they hum! if anyone is interested in them I would be happy to trade them for any interesting ef95 tubes or something that will work on my machine. straight swop! let me know. z


----------



## gibosi

Quote: 





zedmeco said:


> EK90 Röhre tubes (6BE6) Siemens. Hi, I have two pairs of these tubes that I bought some time ago but they do not seem to work with my little dot mk3, baically they hum! if anyone is interested in them I would be happy to trade them for any interesting ef95 tubes or something that will work on my machine. straight swop! let me know. z


 
   
  Would you take a picture of your tubes and post it here? Or perhaps you could point us to the vendor's listing? Not all Siemens EK90s are the same and it would be very helpful to know exactly what you have....


----------



## MIKELAP

Missed my order of Siemens Rohre EH90 yesterday but meanwhile the G.E. have about 12 hours on them and to be honest they started out similar to the 20 hours Hit Ray's but now the sound is muffled with more burnin will see what happens                                                                                                           .


----------



## Audiofanboy

OK, I have to confess I've been having a bit of a problem with my heptodes lately... They _all_ sound good... And it makes testing and comparing them _very_ difficult. Add the three -I'm still trying to figure out a practical way to use the fourth one- strapping settings and you've got a bit of a headache ahead of you... I feel like I'm 3 feet deep in "heptode cases" to test!
   
  Anyway, for once, instead of doing long burn-in periods -both electrical and brain burn-in- for each tubes, I tried to kind of "blitz compare" a few of my newest ones (the ones for which I didn't have a solid brain impression and conclusion for like the 5915); normally this wouldn't work since the tubes aren't exactly burnt-in, but it kind of does since many of those latest tubes have either had the level of detail and "musical glory" I seek right from the get go, or basically have not; burn-in just mixing things up a little (bass tightening, etc...).
   
  So, here are a few conclusions after this (and, again, take my -and others- comments about strapping settings with a grain of salt, since the gear you have seems to have a pretty heavy influence on which setting you'll eventually settle for; at least that's the _only_ pattern I can discern for now regarding strapping heptodes) and also a few thoughts after browsing Google way too much at night:
   
  - The IBM 1680 (1950, made by RCA for IBM, basically a 6BE6 with grid 3 like a 6BY6, so for all intents and purposes a computer rated RCA 6BY6 prototype) I got have a very special, lovely and addictive -foot tapping- sound that is unlike anything I've heard from a heptode yet. Think heptode detail with pentode musicality; yeah, that sounds nice, doesn't it? You can get these on ebay in the US for about $3 a tube if you negotiate; honestly, if you live in the US, get a pair! Anyway, I've only used these for 3 hours, and the bass was still all flabby, but they made for an extremely pleasant listen! They sound more relaxed and realistic unstrapped than 1-7 strapped -on my gear and to my ears- btw; they immediately showed quite a treble bias, like a slip of every frequency towards treble, when strapped.
   
  - My two kind of Haltmens (CV453 labeled and 6BE6 labeled) sound very similar, and I believe the slight differences I'm hearing are your basic placebo effect and expectation bias; that and one pair being more burnt-in than the other. Both pairs sound quite glorious, with the top-tier level of detail we've come to expect from heptodes, musical realism and focus.
   
  - Or so I thought, but testing some unburnt-in Telefunken EK90, I have to admit that the Haltmens have some serious competition. Basically, the Telefunken seem to be at least on the same level in terms of detail, focus and realism, but have harder hitting bass and even better treble; trade-off seems to be that they are just a bit more forward and maybe treble biased -unstrapped and unburnt-in- but not as forward as my Tele EH900S, which were _too_ forward imho. I'll actually give these a proper burn-in now, but I could swear they render more detail than the Siemens... Anyone else have both to compare?
   
  - Thoughts: from google tube literature, we'd assessed that grid 3 on 6BE6/EK90 has remote-cutoff curves (meaning that, despite being the actual "control grid" in the tube -unlike the oscillator grid 1 we've been using as a signal grid- we shouldn't use it in our triode-strapped preamp gain stage application as a signal grid), which is why I won't even bother 1-7 strapping it to grid 1 in those tubes anymore, since it doesn't make sense and doesn't sound the best. Basically, grid 1 and grid 3 on those tubes have different characteristics and are meant for different applications; we've ended up using a non-control sharp-cutoff grid for another application than it was intended for; we didn't have a choice and it works fine, so great, let's keep doing that.
   
  - 6BY6 tubes, on the other hand, are switching tubes, with two actual control grids, both of which have sharp-cutoff characteristics (and similar gain/mu, to the best I understand and have read). Both grids can, logically, be used as signal grids -grid 3 would be the one that is actually meant to have a negative voltage bias, like grid 1 in pentodes or triodes though- and we've been using grid 1 for that because it's easier. Working out a way to neutralize grid 1 are using grid 3 as the signal grid, as I've suggested before, would make perfect sense, but may not be worth the extra trouble, since we can't prove that one of the two grids would work better, as they are quite similar. So using grid 1 is fine here too. Actually, any setting seems fine for 6BY6 tubes, both in theory and in practice.
   
  - Enter 6CS6/EH90 tubes. These have traits from both the above tubes: they're meant for some kind of TV application and not as switching or logic tubes, but both grids are control grids with sharp-cutoff curves. But, unlike a 6BY6, the two grids have very different gain/mu, with grid 3 having about three times the mu of grid 1 (high mu isn't necessary for good function, but is a good thing as far as I'm concerned; my _only_ issue with all our heptodes so far is that they have a very low mu, and therefore low volume). Basically, grid 3 has better characteristics as a "virtual triode" signal grid for a hi-fi preamp than grid 1 does. So, for 6CS6/EH90, neutralizing grid 1 (strap to cathode) and using grid 3 as the signal grid (tying it _somehow_ to socket hole 1) would make more sense than just using grid 1. No, it's not necessary, but it just seems like a better way of using the tubes, that I'm very seriously trying to figure out an easy way to test, short of an adapter. Strapping grids 1 and 3 together could work fine (anyone try it actually?), but I have no idea how tying two grids with different gain characteristics will behave; I don't think it can't sound bad, I just don't know.
   
  Anyway, sorry for long babble, but I still think we need to make sense of _how and why_ our different types of heptodes behave the way they do, if we actually want to eventually understand what we're doing here (up to now, we've just slapped some tubes in our amps, just expecting them to work; we're reaching the limits of that system with heptodes imo; and as some have pointed out, we just can't test dozens of tubes with two or three different settings every time...).


----------



## Acapella11

Hi Gibosi and everyone else of course,
   
  OK, I have made it to use my camera, finally. Here comes a little picture galore to update you guys with the new tubes I have in my inventory. 
   
  Siemens EK90 (6BE6): black bottom, no logo, saucer getter, 4 extended square holes at bottom and top front at back of tube, 02/78
  These should be the of the same type as hypnos1 has. They were from here but are not listed anymore.

   
  Siemens EH90 (6CS6): halo getter, 4 extended square holes at bottom and top front at back of tube, 06/78

   
  Telefunken EH900S (6BY6, special quality): gold pins, diamond logo, six extended rectangular holes, of which 4 top and bottom on front and back plus two additional ones almost front and back in the center, "Made in Germany" label, Ulm 24/01/66 or 76

   
  Telefunken EH90 (6CS6): diamond logo, "Made in Germany" label, same holes as the EH900s above, Ulm 26/06/66 or 76

   
  From these tubes, at the moment (considering burn etc.), I prefer the Siemens EK90 but obviously the general level is high. The Amperex E91H (2/7-strap) comes close (but) with a different signature.
   
  I have saved the Russian 6A2P pictures and a surprise for later.


----------



## gibosi

Quote: 





audiofanboy said:


> - The IBM 1680 (1950, made by RCA for IBM, basically a 6BE6 with grid 3 like a 6BY6, so for all intents and purposes a computer rated RCA 6BY6 prototype) I got have a very special, lovely and addictive -foot tapping- sound that is unlike anything I've heard from a heptode yet. Think heptode detail with pentode musicality; yeah, that sounds nice, doesn't it? You can get these on ebay in the US for about $3 a tube if you negotiate; honestly, if you live in the US, get a pair! Anyway, I've only used these for 3 hours, and the bass was still all flabby, but they made for an extremely pleasant listen! They sound more relaxed and realistic unstrapped than 1-7 strapped -on my gear and to my ears- btw; they immediately showed quite a treble bias, like a slip of every frequency towards treble, when strapped.


 
   
  As these RCA-made (1950) IBM 1680 are an early 6BY6 prototype, it seemed very appropriate to compare them to the RCA 5915/6BY6 (1963) I have on hand. While I expected them to share the same RCA house sound, I was quite surprised to discover that these two tubes are virtually indistinguishable, at least to my ears on my gear. As cheap as these are, I agree with AFB, you need to get a pair of these! Even if you already have a pair of RCA 6BY6, you should still get a pair! You will have a little bit of tube history in your hands: a prototype of the RCA 6BY6... and they sound good!  
   


> - Or so I thought, but testing some unburnt-in Telefunken EK90, I have to admit that the Haltmens have some serious competition. Basically, the Telefunken seem to be at least on the same level in terms of detail, focus and realism, but have harder hitting bass and even better treble; trade-off seems to be that they are just a bit more forward and maybe treble biased -unstrapped and unburnt-in- but not as forward as my Tele EH900S, which were _too_ forward imho. I'll actually give these a proper burn-in now, but I could swear they render more detail than the Siemens... Anyone else have both to compare?


 
   
  Yes, I have a pair of both of these tubes. (It seems I have a pair of almost everything.. lol)  I gave a cursory review of both of these tubes on page 105, along with the Brimar CV4012 and Philips/Amperex 6687/E91H. I haven't spent much time with the Telefunken EK90s since then, so I plugged them in this evening, and am listening to them as I write. At that time, I felt that they were a bit too forward for my taste, but it seems that over the course of the past 20 pages, my ears have come to appreciate a more forward and treble biased tonality. (Listening to 6AV6/EBC91 triodes probably had something to do with this! lol) Anyway, I like what I am hearing and plan to spend more time with them.


----------



## bruce108

On the Telefunken EK90s. At first, mine were not so much treble-forward as bass-light and overall a bit thin-sounding, if refined and musical (EF95). But after 40-50 hrs they became a dramatically different tube, excellent bass in quantity and quality and well-balanced through the FR. Here's the thing: they warm up more slowly than any of my other tubes, taking an hour or so to reach their optimum. Any technical reason for this?


----------



## gibosi

Quote: 





bruce108 said:


> On the Telefunken EK90s. At first, mine were not so much treble-forward as bass-light and overall a bit thin-sounding, if refined and musical (EF95). But after 40-50 hrs they became a dramatically different tube, excellent bass in quantity and quality and well-balanced through the FR. Here's the thing: they warm up more slowly than any of my other tubes, taking an hour or so to reach their optimum. Any technical reason for this?


 
   
  I probably don't have more than 30 hours on mine, but even so, I don't find the bass to be light on these at all. Out of curiosity, I also compared them to the Telefunken EH900S (I have about 25 hours on these). Both of these tubes share the same house sound and have a very similar tonality. And most noticeably, unlike AFB, I do not find the EH900S to be any more forward than the EK90. I wonder why? My EH900S do not have gold pins... Maybe those with gold pins are actually different?


----------



## Audiofanboy

Quote: 





bruce108 said:


> On the Telefunken EK90s. At first, mine were not so much treble-forward as bass-light and overall a bit thin-sounding, if refined and musical (EF95). But after 40-50 hrs they became a dramatically different tube, excellent bass in quantity and quality and well-balanced through the FR. Here's the thing: they warm up more slowly than any of my other tubes, taking an hour or so to reach their optimum. Any technical reason for this?


 

 So, I'm good for yet _another_ 50 hour burn-in huh...? The things we do for music...
   
  While I definitely noticed that they improve after a bit of warm-up time -most tubes do to some extent- I have haven't noticed anything as dramatic as a whole hour. I guess it's possible though, I remember thinking that even my old stock M8100 needed 15-20 minutes to sound their best.
   
  Again, I find it pretty difficult to directly compare these heptodes together, and find myself forced to compare "lasting impressions" instead, which I usually do fairly well, but isn't exactly a fail-safe method. The fact that _everyone_ here has different impressions of the Telefunken EH900S (regardless of gold pins, as I just saw that A11's have them and gibosi's don't, yet same comments) does strike me as odd -as in my impressions being off.
   
  I had tested and burnt-in the Tele EH900S with the 1-7 strap until the very end, when I tried them unstrapped and concluded that was best; so, that probably influenced my impressions in and of itself (the tubes really were quite "in your face" when strapped, and I'm now pretty sure that needed way more than the 20 hours of burn-in I gave them anyway; most premium tubes do apparently). The fact that everyone says the EH900S (6BY6) and EK90 (6BE6) Telefunken are similar makes me think that they, indeed, are -which would make perfect sense as they look similar anyway- and that I just need to eventually throw the EH900S back in the sockets to confirm that. I will, at some point, after the 40h burn-in...
   
  I do like that hard-hitting bass (not strong, just intense and punchy) on the Tele EK90 though. I still have some serious comparing to do with all those other German heptodes. Another German shootout?


----------



## Oskari

Quote: 





acapella11 said:


> Elektronenroehre
> Siemens AG Muenchen 80
> 
> The fact that there is no German "ö" but "oe" instead points further to not one of the regular German productions.


 
   
  I think this rather points to limited character sets of early computers.


----------



## Oskari

Quote: 





mikelap said:


>


 
   
  I haven't seen the name Svetlana mentioned. That's what we have here. Note the =C= logo.


----------



## mab1376

Quote: 





audiofanboy said:


> So, I'm good for yet _another_ 50 hour burn-in huh...? The things we do for music...
> 
> While I definitely noticed that they improve after a bit of warm-up time -most tubes do to some extent- I have haven't noticed anything as dramatic as a whole hour. I guess it's possible though, I remember thinking that even my old stock M8100 needed 15-20 minutes to sound their best.
> 
> ...


 
   
  I think I like the EK90 with the 7-1 strap since it adds some brightness to my HD650's which are relatively dark. I know you've said before the 7-1 on the EK90 for you was too fatiguing for you, which headphones are you using?
   
  I also ordered a pair of the 1680's curious to see how earlier variants sounded.


----------



## Audiofanboy

Quote: 





mab1376 said:


> I think I like the EK90 with the 7-1 strap since it adds some brightness to my HD650's which are relatively dark. I know you've said before the 7-1 on the EK90 for you was too fatiguing for you, which headphones are you using?
> 
> I also ordered a pair of the 1680's curious to see how earlier variants sounded.


 

 Nope, never tried the 1-7 strap on a 6BE6 type, only on 6BY6 types, where I do find the setting often a bit too treble-centric.
   
  I'm using HifiMAN HE-500 headphones, which is quite silly with an OTL tube amp, but works great, oddly enough. Some would say these are neutral, but they do have a hump or two in the upper mids and treble; so, while it's hard to make them "fatiguing", it is easy to make them a bit too treble oriented, or too detailed essentially.
   
  I'm sure you'll like the 1680, they're interesting tubes; and as gibosi pointed out, it is quite amusing to know you're using almost "historical" tubes, that were basically made for "vacuum tube computers". Makes for great small talk when have people over lol (that, and the USSR power tubes)!


----------



## mab1376

Quote: 





audiofanboy said:


> Nope, never tried the 1-7 strap on a 6BE6 type, only on 6BY6 types, where I do find the setting often a bit too treble-centric.
> 
> I'm using HifiMAN HE-500 headphones, which is quite silly with an OTL tube amp, but works great, oddly enough. Some would say these are neutral, but they do have a hump or two in the upper mids and treble; so, while it's hard to make them "fatiguing", it is easy to make them a bit too treble oriented, or too detailed essentially.
> 
> I'm sure you'll like the 1680, they're interesting tubes; and as gibosi pointed out, it is quite amusing to know you're using almost "historical" tubes, that were basically made for "vacuum tube computers". Makes for great small talk when have people over lol (that, and the USSR power tubes)!


 
   
  BTW The ones I ordered are: 1680 IBM 6BE6 Vacuum Tube marked 1680, 6B3001, 303613 code dated 0-04 or 0-13 , 274 meaning 1950 the 13th week.


----------



## mordy

Hi MAB 1376,
   
  The ones I got have the same information as yours, but date codes 0-09 and 3-22 which I think means 9th week 1950 and 22nd week 1953.
   
  274 stands for Radio Corporation of America - RCA
   
  Look, for $3 each + $1.69 shipping you cannot go wrong.


----------



## Oskari

Quote: 





acapella11 said:


> Siemens EK90 (6BE6): black bottom, no logo, saucer getter, 4 extended square holes at bottom and top front at back of tube, 02/78
> These should be the of the same type as hypnos1 has. They were from here but are not listed anymore.


 
   
  Those could be Svetlanas, too. I see plenty of similarities. Certainly of USSR origin.
   


> Siemens EH90 (6CS6): halo getter, 4 extended square holes at bottom and top front at back of tube, 06/78


 
   
  The octagonal box around the type code is not typical for Siemens and, I wonder, foreign to which market.
   
  I'd expect a Siemens-made tube to have an etched code like Philips-made tubes, or later on a piece of metal embossed with 4 characters inside the tube.
   
  Siemens made tubes in Munich but obviously also labeled tubes made by others, especially towards the later tube era.


----------



## mordy

Is it possible that these tubes are the "FOREIGN" manufacturer of the Siemens EH90 678 tubes? Take a look at the various pictures in this ad:
   
  http://www.ebay.com/itm/TESTED-Russian-6A2P-GEPTODE-tube-6BE6-EK90-6H31-X77-NOS-10-pcs-/310700109772?pt=LH_DefaultDomain_0&hash=item48572b6fcc


----------



## gibosi

Quote: 





mordy said:


> Is it possible that these tubes are the "FOREIGN" manufacturer of the Siemens EH90 678 tubes? Take a look at the various pictures in this ad:
> 
> http://www.ebay.com/itm/TESTED-Russian-6A2P-GEPTODE-tube-6BE6-EK90-6H31-X77-NOS-10-pcs-/310700109772?pt=LH_DefaultDomain_0&hash=item48572b6fcc


 
   
  I believe that Russian EH90s typically had saucer getters, whereas A11's tubes have halo getters. However, I can't quite make out from the photos whether these Russian tubes have saucer or halo getters?
   
  I should also note that I seriously doubt that the three digit number is the date of manufacture. One of my Siemens EH90 has the three-digit code 201. Manufactured in February '01? lol It is my understanding that these codes are some sort of "batch" code that had some meaning within the factory, perhaps something similar to the "change" code within Philips factories.
   
  It is known that Siemens closed their Munich Halske factory in 1971 and transferred all production to somewhere in Eastern Europe. So my best guess is saucer getters indicates Easter Europe. Halo getters? If not Munich, then where? If Philips, I think we should see a standard Philips tube code, but none are visible on A11's tubes....


----------



## gibosi

Quote: 





oskari said:


> I'd expect a Siemens-made tube to have an etched code like Philips-made tubes, or later on a piece of metal embossed with 4 characters inside the tube.
> 
> Siemens made tubes in Munich but obviously also labeled tubes made by others, especially towards the later tube era.


 
   
  These etched codes are apparently standard on their dual triodes, but not on all their tubes. I have used a magnifying glass to scrutinize my Siemens EK90 and EH90, two different pairs each, all with the Siemens/Halske logo, and can find no codes of any kind, on the glass or inside.


----------



## mordy

Let's try this:
   
  Go to the Ebay ad again, and look at the pictures. On the left is a slider; pull it down, and there is one more picture there. Using the CTRL button and the scroll wheel on the mouse, blow up the picture. Then use the Mouse Here To Zoom In feature and look carefully at the getter. IMHO it is a circular getter. (The third picture blown up also supports this.) The ribbing of the plate looks like the Siemens tube.
   
  If this indeed is it, we have a cheap supply of ersatz Siemens tubes....


----------



## mordy

About the date code: Perhaps it is logical that 678 refers to August 1967 or 8th week 1967?
   
  About the 201: Somewhere on this blog I saw a post that the box AND the tube had a unique number, such as 201.


----------



## gibosi

Quote: 





mordy said:


> About the date code: Perhaps it is logical that 678 refers to August 1967 or 8th week 1967?
> 
> About the 201: Somewhere on this blog I saw a post that the box AND the tube had a unique number, such as 201.


 
   
  I have two different pairs of Siemens EH90, one with a three-digit code of 201, and the other, 271. And yes, in each case, this number is also printed on the corresponding box. So if 271 implies 1971, what does 201 imply?


----------



## gibosi

Quote: 





mordy said:


> Let's try this:
> 
> Go to the Ebay ad again, and look at the pictures. On the left is a slider; pull it down, and there is one more picture there. Using the CTRL button and the scroll wheel on the mouse, blow up the picture. Then use the Mouse Here To Zoom In feature and look carefully at the getter. IMHO it is a circular getter. (The third picture blown up also supports this.) The ribbing of the plate looks like the Siemens tube.
> 
> If this indeed is it, we have a cheap supply of ersatz Siemens tubes....


 
  A slider? Mouse Here to zoom in feature? a mouse CTRL button? Not on my Win7 PC... Perhaps you have something different....
   
  Anyway, in the fifth picture, I think I see a saucer getter, but due to reflections in the glass, I am not sure.....


----------



## Audiofanboy

I'm definitely seeing a saucer getter on at least one of these pictures. And regardless, the shiny & pointy pins -and everything else- just screams Eastern German/Eastern European/Russian origin... These tubes aren't West German at any rate.
   
  Doesn't mean they're bad tubes though. If someone wants to get 10 or 20 of these and dispatch them to everyone around here, I'd be more than willing to get a pair... I won't shed $26 on blind -Russian- faith though...


----------



## Oskari

audiofanboy said:


> I'm definitely seeing a saucer getter on at least one of these pictures. And regardless, the shiny & pointy pins -and everything else- just screams Eastern German/Eastern European/Russian origin...




Absolutely. In fact, the symbol of the manufacturer, the Oktyabr factory in Vinnytsia, Ukraine, is visible on the tube and on that piece of paper.


----------



## MIKELAP

im expecting 10 of these any day now had bought the ones on mordy's picture for $26.00 on Ebay but saw the same elsewhere in Bulgaria i think for $15.00 so canceled the original order


----------



## mordy

Heptode overload?
   
  Looks like we have two Russian heptodes available, both 6A2A. The one with the C around the designation is made by Svetlana, which is a very reputable manufacturer.
   
  The second type is labeled Elektronorgtecnika and made in the Octyabr (October) factory in Ukraine. (Apparently Russia and Ukraine are two different countries according to the cognoscenti, so forgive me if I call both Russian tubes.)
   
  AFB, I can understand your frustration in ferreting out the best sounding heptodes since there are so many settings to try - EF95 NS (no strap), EF95 1-7 strap, EF95 2-7 strap, EF92 NS. And then the observation that it may take 50 hours of burn in to get to hear the true nature of the tube. And then that they all sound good, which in itself is not a bad thing. However, this makes it so much harder to pick winners.
   
  Don't understand why you seem to be hesitant about Russian heptodes. After all, all the driver tubes for the LD MKIII/IV are Russian made. I seem to remember that the Svetlana 6A2A did not seem to impress in one review. However, maybe we have to reserve judgment until the tubes have been tried for more than 50 hours.
   
  In general, we are all very grateful for all your painstaking research and efforts - thanks!


----------



## gibosi

Quote: 





mordy said:


> Don't understand why you seem to be hesitant about Russian heptodes. After all, all the driver tubes for the LD MKIII/IV are Russian made. I seem to remember that the Svetlana 6A2A did not seem to impress in one review. However, maybe we have to reserve judgment until the tubes have been tried for more than 50 hours.


 
   
  While I can't speak for AFB, I can tell you why I am hesitant about these tubes.... You might remember, I bought some Russian 6J4P/6AU6 (page 62 - see here), and they were very poor quality. Since then, my thinking is only "premium" Russian tubes from now on, that is, tubes with the -e, -ev or similar suffix, like the Voshods 6zh1p-ev, for example. Searching for 6A2P-e and 6A2P-v comes up empty.....
   
  But of course, if others in this forum are willing to give them a chance and then report that these 6A2P are excellent, I will pounce on them! lol


----------



## Audiofanboy

I never said I didn't want to buy Russian or Eastern European tubes, but, in a way, yes, I would be quite careful about those tubes, and wouldn't just blindly stick them in my amp without a bit of information.
   
  Like gibosi said, tube quality varied quite a bit in Eastern production, and while the best and most rugged ones are clearly top-tier -I paid quite a bit to get some genuine DR power tubes and I can vouch for those types being almost god-tier- whether mil-spec or just very good civilian tubes, many of the more basic ones can show wide variations. Even -E or -EV tubes aren't always that good and have widely different quality control depending on year and factory...
   
  Speaking of variations, -and that's actually my main concern over money and sound quality- many Soviet or Eastern tubes, while close, weren't exactly made to the same specs as their Western equivalents (slightly different tubes, basically), so you never really know what you're getting. They're exactly that: _equivalents_. Some tube type are very close or identical in specs like the 6AK5 and 6ZH1P, others are much further apart like the 6N23P and other common double triodes. Will they work? Probably, but I do like to know what I putting in my amp, just in case...
   
  Again, I'd be more than willing to shed a few bucks for some interesting Ukrainian tubes or other, but the last couple of times I went for one of those "10 or 20 tubes for peanuts" deal, it turned out to have been a bad idea, every time... And the last time, it was -E tubes too!


----------



## mordy

http://www.ebay.com/itm/6A2P-6BE6-EK90-Heptode-Tubes-5pcs-in-BOX-NOS-1980s-/350748093273?pt=Vintage_Electronics_R2&hash=item51aa372b59
   
  These Elektronorgtecnika 6A2P tubes from 1986 definitively have saucer type getters, but the plates are not ribbed like the previous post of these tubes.


----------



## gibosi

I have received a few more triodes recently, so off to triode land I go... 
   
  These Philips Miniwatt CV452 are actually 6AT6 which are very similar to the 6AV6. They were manufactured in the 1950s by Philips in their Heerlen, Holland factory, so these likely were also sold under the Amperex/Bugleboy brand as well.
   

   
  1950's Lorenz, identical to AFB's (page 102)
   

   
  1970's Telefunken, identical to AFB's (also page 102)
   

   
  And finally, Tungsram EBC91/6AV6, manufactured in Hungary. With O-getters and rather new-looking boxes I have the impression that these are not that old. And from this pdf, the "w" printed on the glass might suggest 1982, but who knows?
   

   
   
  Since I already have some Mullard EBC91, I now realize that I have managed to collect another example of the so-called  "British - Holland - German sound continuum", with Hungary thrown in for good measure! lol
   
  And of course, even though I am now back in triode land, I will continue to follow with great interest all the wonderful news from heptode land.


----------



## Audiofanboy

We're all expecting some major European double diode-triode shootout now gibosi; your ears may not make it though four different pairs of triodes lol!
   
  Just fyi, if anyone's interested, I still have an extra pair of the Philips CV452 (I have a _lot_ of extra pairs of a _lot _of tube types actually...).


----------



## sssboa

What are pins of 80's Voshkod ef95 tubes covered with, silver, platinum, nickel?


----------



## hypnos1

Quote: 





mikelap said:


> im expecting 10 of these any day now had bought the ones on mordy's picture for $26.00 on Ebay but saw the same elsewhere in Bulgaria i think for $15.00 so canceled the original order


 
   
  Hi mikelap.
   
  This Siemens EK90 saga is developing into one of real Nordic proportions...I say this because, along with other factors, I would swear that mine (and therefore A11's) are one and the same as the tube shown here in the photo : pins; internal copper wire; saucer getter, and SMOOTH silver/grey plate. I have 2 pairs - one with clear bottom and one with black - the latter mentioned by A11, just to confuse matters even more...
   
  To add to the confusion, I have noticed OTHER  Svetlana 6A2Ps that have slight ribbing on the plate...which I think are the ones you have ordered mikelap...
   
  The internal construction of these Svetlanas certainly does appear superior to the other make(s) that are on the web.
  So the plot thickens...
   
  Now onto the sound that comes from my 'Siemens', whoever actually made them...
   
  To strap or not to strap? This really is becoming another source of confusion (for me anyway). After finding that further burn-in with 1-7 tamed the initial 'shock' factor, I returned to non-strap and was pleased to find that Acapella 11's comparison on page 109 seemed absolutely on the ball - what really hit me straight away was a more open/airy sound, bordering almost on 'thin', compared to 'lush/heavy' 1-7 (I leave the proper terminology to A11!!). I would simply summarise the overall effect - for me - as more 'polite/refined' non-strapped, but more 'exciting' strapped.
  Which do I prefer? Damned if I can yet be sure!! I think this debate could go on forever...
   
  I envy you M that you came to your own conclusion so quickly...if only I could!


----------



## mab1376

Quote: 





hypnos1 said:


> Hi mikelap.
> 
> This Siemens EK90 saga is developing into one of real Nordic proportions...I say this because, along with other factors, I would swear that mine (and therefore A11's) are one and the same as the tube shown here in the photo : pins; internal copper wire; saucer getter, and SMOOTH silver/grey plate. I have 2 pairs - one with clear bottom and one with black - the latter mentioned by A11, just to confuse matters even more...
> 
> ...


 
   
  I personally really like the 7-1 strap on the HD650, but with my Pro900 its way too sibilant. To me that setting just adds a lot of high en detail, which can be fatiguing on already sibilant cans like Ultrasones. I haven't tried with my T70 yet but they are also bright out of the box and would probably feel the same way.


----------



## mordy

Hi sssboa,
   
  Somewhere in the back of my mind I think I remember reading that the pins on some Russian tubes were coated with rhodium which does not oxidize, but cannot remember the source. Rhodium is a member of the platinum family and often used in corrosion and heat resistant applications.
   
  AFB - what do you think?


----------



## Audiofanboy

Quote: 





sssboa said:


> What are pins of 80's Voshkod ef95 tubes covered with, silver, platinum, nickel?


 
   
  Quote: 





mordy said:


> Hi sssboa,
> 
> Somewhere in the back of my mind I think I remember reading that the pins on some Russian tubes were coated with rhodium which does not oxidize, but cannot remember the source. Rhodium is a member of the platinum family and often used in corrosion and heat resistant applications.
> 
> AFB - what do you think?


 

 Yup Mordy, you were faster than me to answer! All those tubes have rhodium-coated pins, from what I read about a year ago when I was investigating tubes manufactured in the USSR. Basically, all those pointy -Russian or Eastern- pins all look the same and have the same shine, so I would be pretty sure that they all have the same standard coating.
   
  Think of rhodium as being about as good as gold in terms of plating qualities, i.e. resistance to corrosion and good conductivity. I remember my -since then sold- HD650 DIY connectors being also rhodium plated; just a random hi-fi-ish example. Gold being more "fashionable", we don't actually get to see many "rhodium plated" cables or anything that often though...


----------



## MIKELAP

Quote: 





hypnos1 said:


> Hi mikelap.
> 
> This Siemens EK90 saga is developing into one of real Nordic proportions...I say this because, along with other factors, I would swear that mine (and therefore A11's) are one and the same as the tube shown here in the photo : pins; internal copper wire; saucer getter, and SMOOTH silver/grey plate. I have 2 pairs - one with clear bottom and one with black - the latter mentioned by A11, just to confuse matters even more...
> 
> ...


 
  I will know tommorrow what they are will post a closeup of the plates for you to check out ya missed the mailman today finally guy from bulgaria wasnt putting me on it took less than 2 weeks from Russia was 1 month so thats great but did not get the Siemens rohre eh90 from Germany yet. and finally update for the G.E.6AV6  after sounding muffled they opened up again i must be going nuts but i did not try the Hit Ray again will take a break for a few days.


----------



## siles1991

Was planning to get these since few pages back I was suggested to get them. http://www.ebay.com.my/itm/6N6P-IR-ECC99-E182CC-high-durable-double-triode-tubes-Lot-of-2-pc-NOS-/300693108383?pt=LH_DefaultDomain_0&hash=item4602b4b69f&_uhb=1#ht_698wt_1139
   
  Would this be right? The 6N6P-IR. And was wondering if anyone had experience with the Sylvania EK90's because the 12AU7 Sylvania's were really really good on my previous amp and was wondering how they fared.


----------



## Johnnysound

Hi Mikelap, 
   
  This forum is fascinating for me.  You know, I am not an authentic "tube roller" as you are, along with  many others here.  Much worse, I was not really a  headphone guy, I mean,  not my  main interest after more than 25 years in audio.  By chance, I arrived into this forum and read many really good, well informed, technically correct, well written comments about the LD MKIII and tube rolling so I was inmediately interested.  You know, my audio instincts told me that something was happening here, so I went for the LDMKIII  and followed the advice installing some NOS Tung-Sols 6485 with the "2-7" trick.  After some posts, it is confirmed that my five TS tubes are perhaps late sixties stock, very nice ones. It is a solid, durable tube made for TV sets.  Burn-in of these tubes is not linear, and it is relatively long.  After the first 20 hours or so, its sound become smoother, still with a prominent bass and top end, but after 60 hours the tube stabilized nicely and reached what I think is its full performance, with a balanced, detailed, full-bodied and dynamic sound.  So good that I see no reason to roll them ¡¡ Is there anything out there really superior ??
   
  Kind regards,
   
  Johnysound


----------



## Audiofanboy

To answer posts above, I don't believe anyone has tried the Sylvania EK90/6BE6, but the premium 6BY6 Sylvanias, the 5915, have been tested by a few people and reported to be top-tier, even among heptodes.

And while the TS 6485 would still be my number 1 pentode, I really do think it is worth a heptode or two to try, as some of the are truly great tubes!


----------



## siles1991

audiofanboy said:


> To answer posts above, I don't believe anyone has tried the Sylvania EK90/6BE6, but the premium 6BY6 Sylvanias, the 5915, have been tested by a few people and reported to be top-tier, even among heptodes.
> 
> And while the TS 6485 would still be my number 1 pentode, I really do think it is worth a heptode or two to try, as some of the are truly great tubes!




Are these the ones?http://www.ebay.com.my/itm/FOUR-5915-SYLVANIA-TUBES-N-O-S-/221251488698?pt=Vintage_Electronics_R2&hash=item33839dcbba#ht_800wt_923


----------



## siles1991

audiofanboy said:


> To answer posts above, I don't believe anyone has tried the Sylvania EK90/6BE6, but the premium 6BY6 Sylvanias, the 5915, have been tested by a few people and reported to be top-tier, even among heptodes.
> 
> And while the TS 6485 would still be my number 1 pentode, I really do think it is worth a heptode or two to try, as some of the are truly great tubes!




Are these the ones?http://www.ebay.com.my/itm/FOUR-5915-SYLVANIA-TUBES-N-O-S-/221251488698?pt=Vintage_Electronics_R2&hash=item33839dcbba#ht_800wt_923


----------



## Audiofanboy

Quote: 





siles1991 said:


> Are these the ones?http://www.ebay.com.my/itm/FOUR-5915-SYLVANIA-TUBES-N-O-S-/221251488698?pt=Vintage_Electronics_R2&hash=item33839dcbba#ht_800wt_923


 

 Yup, those look the same as the ones around here. Their sound changes in interesting ways depending on how you strap them. I personally like them best 1-7 strapped, but I know they sound excellent unstrapped as well.


----------



## siles1991

audiofanboy said:


> Yup, those look the same as the ones around here. Their sound changes in interesting ways depending on how you strap them. I personally like them best 1-7 strapped, but I know they sound excellent unstrapped as well.



Alright thanks pulled the trigger on it haha now awaiting my valvos and these sylvanias and currently using voshkods with stock GE tubes from LD. So I have a enough tubes to last me a long time.


----------



## Audiofanboy

Quote: 





siles1991 said:


> Alright thanks pulled the trigger on it haha now awaiting my valvos and these sylvanias and currently using voshkods with stock GE tubes from LD. So I have a enough tubes to last me a long time.


 

 Nice, I'm sure you'll like the Sylvanias!
   
  Curious as to what the Valvo you got look like though, any chance you could throw in an -ebay?- link? Most Valvo 7-pin hetpodes I've seen around always seemed to have been made by Mullard or Philips; can't know for sure unless I see some factory codes...


----------



## siles1991

audiofanboy said:


> Nice, I'm sure you'll like the Sylvanias!
> 
> Curious as to what the Valvo you got look like though, any chance you could throw in an -ebay?- link? Most Valvo 7-pin hetpodes I've seen around always seemed to have been made by Mullard or Philips; can't know for sure unless I see some factory codes...



Here you go gibosi suggested so I'm taking the risk on it http://www.ebay.com.my/itm/370836056707?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649#ht_581wt_689 they've reached my country and prolly going through customs, should get them by monday or tuesday. Aiming to get some TS 6AH6WA and the 6N6P-IR and i'll have a lot of selections xD


----------



## mab1376

so the 5915 is a higher quality spec than the 6BY6/EH900S?


----------



## gibosi

Quote: 





mab1376 said:


> so the 5915 is a higher quality spec than the 6BY6/EH900S?


 
   
  No, they are the same: 5915 = EH900S.
   
  5915 is the American designation and EH900S is the European designation.
   
http://www.radiomuseum.org/tubes/tube_5915.html
   
  And notice: 
   
*Normally replaceable-slightly different:*
   
  1680; 2032; 5915A; 6687; E91H


----------



## TrollDragon

I have a LD MKIV with stock tubes now so I am just starting down the road of tube collection. I have been offered a pair of NOS unused Mullard 4010's. What is a fair price to pay for those?
In following this thread for a while I see everyone getting Heptode's, are they all very similar sounding? And if I do decide to pick some up should I look for multiples instead of pairs? Possibly thinking about channel imbalance.

Just new to the tube game, sorry if these questions have been answered before but the search function on HF leaves a lot to be desired.

Thanks!

Sent from my HTC Desire HD A9191 using Tapatalk 2


----------



## MIKELAP

Got these today look to be Electronorgtecnika 6a2p otk 7 ruggerdized for military purpose i guess saucershaped  will sample them in a near future where not the same tubes as advertised on the picture but for $23.00 total for 10 tubes hope they sound decent at least .


----------



## jaywillin

ok, they say the only stupid question is the question you dont ask
   
  how do you open the LD1+, to adjust for different tubes, lol
  i don't just want to start unscrewing everything,


----------



## jaywillin

Quote: 





jaywillin said:


> ok, they say the only stupid question is the question you dont ask
> 
> how do you open the LD1+, to adjust for different tubes, lol
> i don't just want to start unscrewing everything,


 

 nevermind !! got it !! lol


----------



## Acapella11

Quote: 





siles1991 said:


> Was planning to get these since few pages back I was suggested to get them. http://www.ebay.com.my/itm/6N6P-IR-ECC99-E182CC-high-durable-double-triode-tubes-Lot-of-2-pc-NOS-/300693108383?pt=LH_DefaultDomain_0&hash=item4602b4b69f&_uhb=1#ht_698wt_1139
> 
> Would this be right? The 6N6P-IR.


 
   
  Ask these guys from which year they are. If older than 1984, go for it. Definitely.


----------



## gibosi

Quote: 





trolldragon said:


> I have a LD MKIV with stock tubes now so I am just starting down the road of tube collection. I have been offered a pair of NOS unused Mullard 4010's. What is a fair price to pay for those?
> In following this thread for a while I see everyone getting Heptode's, are they all very similar sounding? And if I do decide to pick some up should I look for multiples instead of pairs? Possibly thinking about channel imbalance.
> 
> Just new to the tube game, sorry if these questions have been answered before but the search function on HF leaves a lot to be desired.
> ...


 
   
  The best price I see on eBay today for a CV4010 is GBP 5.00 (Approximately US $7.56), per tube, plus shipping, so you might want to use this a pricing guide. Paying a premium for a "Matched" pair is a waste of money, in my opinion.
   
  http://www.ebay.com/itm/CV4010-EF95-6AK5W-6AK5-MULLARD-EX-NEW-EQIP-VALVE-TUBE-/390325556807?pt=UK_Sound_Vision_Valves_Vacuum_Tubes&hash=item5ae1375647
   
I would say that there is quite a bit of variation regarding the sound of heptodes, but even so, IMO, the average heptode sounds better than the CV4010 you are currently considering. My best advice is to pick up some inexpensive American brands and give them a try: Sylvania 5915, RCA 5915 or IBM 1680 (made by RCA) would be a good start. The European E91H or 6687 (the same tube, with either or both numbers written on the glass) are also relatively easy to find (To the best of my knowledge, all E91H/6687 were manufactured in the Philips factory located in Heerlen, Holland, regardless of brand.)


----------



## jaywillin

ok, i do need some help, my little dot, doesn't look like the one on the little dot website(the pic with the bottom opened up)
  also, i'm gonna take a wild guess and say that the wires connecting to two tube sockets is strapping ?
  i guess my question, is what are we looking at here ?? what tubes is the amp set up for ?? i hope the pics are good enough for someone to tell ,thanks


----------



## TrollDragon

Hey jaywillin!
Have you looked at the Manual it has all that info in it. 
www.littledot.net/forum/viewtopic.php?f=9&t=819&sid=192ba6cf4956b456227959e608107841#p3202

Sent from my HTC Desire HD A9191 using Tapatalk 2


----------



## mab1376

acapella11 said:


> Ask these guys from which year they are. If older than 1984, go for it. Definitely.




That's the same seller I got mine from. Definitely worth the upgrade!


----------



## TrollDragon

Hey gibosi!
Thanks very much for the info, the offer of the 4010's was for almost double the ones you linked on eBay, so I'll take a pass on those and hunt down some of your suggestions for sure.
The 4 tubes linked a page back, I think they were Sylvania's were sold by a seller in my province here so I probably could have got those without shipping, but alas they are gone. 

Thanks again for the great info, this is going to be fun!


Sent from my HTC Desire HD A9191 using Tapatalk 2


----------



## gibosi

Quote: 





jaywillin said:


> ok, i do need some help, my little dot, doesn't look like the one on the little dot website(the pic with the bottom opened up)
> also, i'm gonna take a wild guess and say that the wires connecting to two tube sockets is strapping ?
> i guess my question, is what are we looking at here ?? what tubes is the amp set up for ?? i hope the pics are good enough for someone to tell ,thanks


 
   
  It appears that your amp is set up for EF95 tubes. The jumpers required to run EF91/92 and 408A tubes do not appear to be in place.
   
  However, I wonder if you are a bit confused about "strapping". Please check out page 77. There, you will find a chart indicating how the various tubes need to be strapped, or not, in order to be used in Little Dot amps. Also, you will find there a section regarding how to "strap."
   
  Note that strapping is done from the top of the amp. Essentially, you will need to find some *26 gauge*,* or smaller, stranded wire*. Again, *stranded, not solid, and very thin*. Cut two small pieces, and strip the insulation off of each end, such that you can bend both of them into a U shape, somewhat like a staple, and carefully insert them into your sockets., one end in pin-hole 1 and the other end in pin-hole 7 (for heptodes). And then, carefully insert your tubes into the sockets. Thus, pin 1 and pin 7 are said to be "_strapped in the socket"._


----------



## siles1991

Is 1967 a good year for TS 6485/6AH6WA?


----------



## Audiofanboy

jaywillin said:


> ok, i do need some help, my little dot, doesn't look like the one on the little dot website(the pic with the bottom opened up)
> also, i'm gonna take a wild guess and say that the wires connecting to two tube sockets is strapping ?
> i guess my question, is what are we looking at here ?? what tubes is the amp set up for ?? i hope the pics are good enough for someone to tell ,thanks



Those are heater wires you see between the tube sockets, nothing to do with strapping. You'll want to follow gibosi's suggestions about that.

And yes, people, forget about the silly 6ak5 tubes... There are many other better and cheaper tubes out there, seriously...


----------



## gibosi

Quote: 





siles1991 said:


> Is 1967 a good year for TS 6485/6AH6WA?


 
  In my experience, the most important thing to look for in the TS 6485 is O-getters. 1967 TS 6485s should have O-getters, so these tubes should be fine.


----------



## TrollDragon

In looking at the MKIV this morning it appears I have the electro-harmonix 6H30PiEH power tubes, I thought those were only for the SE model? They must sub the Pi's in when they run out of the 6H30EB's.
   
  The Driver tubes have 5654 and USA on them with an 3x3 arrangement of etched dots near the bottom. There is remnants of green text on the tube but most of it seems rubbed off. Would these drivers be the GE 5654's or are they subbed out as well?
   
  Since the power tubes are quite a bit more expensive than the drivers, should an extra pair of those be picked up as well?
   
  Thanks!


----------



## Oskari

mikelap said:


> Got these today look to be Electronorgtecnika 6a2p.




The symbol of the Oktyabr factory again on the tube and also on the box. ELORG was just a Soviet import export house.


----------



## gibosi

Quote: 





trolldragon said:


> In looking at the MKIV this morning it appears I have the electro-harmonix 6H30PiEH power tubes, I thought those were only for the SE model? They must sub the Pi's in when they run out of the 6H30EB's.
> 
> The Driver tubes have 5654 and USA on them with an 3x3 arrangement of etched dots near the bottom. There is remnants of green text on the tube but most of it seems rubbed off. Would these drivers be the GE 5654's or are they subbed out as well?
> 
> ...


 
   
  As I have the 1+, others will have to address your power tube questions. But yes, the etched dots clearly indicate that your driver tubes are GE.


----------



## TrollDragon

Quote: 





gibosi said:


> As I have the 1+, others will have to address your power tube questions. But yes, the etched dots clearly indicate that your driver tubes are GE.


 
  Thanks gibosi!


----------



## jaywillin

Quote: 





audiofanboy said:


> Those are heater wires you see between the tube sockets, nothing to do with strapping. You'll want to follow gibosi's suggestions about that.
> 
> And yes, people, forget about the silly 6ak5 tubes... There are many other better and cheaper tubes out there, seriously...


 

 ok, i had read about the "strapping" it the wires did not appear to be that, hence my confusion
  i got this used on the for sale forum here, the tubes that were in it, were the siemens 6ak5's , they seem to work
  and the ge 408's seem to work ok,
  the zaerix ef91's doen't seem to work, bad hum, distortion,  this is my first tube head amp other than a bravo v2, and the indeed g3 i have now
  i want to proceed cautiously , and make sure i got things correct, and understand what i'm looking at, as for moving the jumpers/connectors, is that a matter of sliding off the
  little black things, and moving them to the correct position, ?  in the meantime, back to the diagram, and page 77


----------



## whirlwind

Quote: 





jaywillin said:


> ok, i had read about the "strapping" it the wires did not appear to be that, hence my confusion
> i got this used on the for sale forum here, the tubes that were in it, were the siemens 6ak5's , they seem to work
> and the ge 408's seem to work ok,
> the zaerix ef91's doen't seem to work, bad hum, distortion,  this is my first tube head amp other than a bravo v2, and the indeed g3 i have now
> ...


 
  Yep, on the jumpers


----------



## jaywillin

Quote: 





whirlwind said:


> Yep, on the jumpers


 

 and it does appear then i am using the wrong tubes, ......


----------



## whirlwind

Quote: 





jaywillin said:


> and it does appear then i am using the wrong tubes, ......


 
  May want to switch tubes or jumper settings then....you can also change the gain.


----------



## gibosi

Quote: 





jaywillin said:


> i got this used on the for sale forum here, the tubes that were in it, were the siemens 6ak5's , they seem to work
> and the ge 408's seem to work ok,
> the zaerix ef91's doen't seem to work, bad hum, distortion,  this is my first tube head amp other than a bravo v2, and the indeed g3 i have now
> i want to proceed cautiously , and make sure i got things correct, and understand what i'm looking at, as for moving the jumpers/connectors, is that a matter of sliding off the
> little black things, and moving them to the correct position, ?


 
   
  Yes, the jumpers are the little black things.... Do you have the manual for this amp? If not, scroll down to the bottom of this page and grab it:
   
  http://www.littledot.net/forum/viewtopic.php?f=9&t=819&sid=4e41340ca35a49a0d49ba54f20ed026f
   
  Did you change the jumpers when you tested the 408As and the EF91s? If not, then the amp was not configured properly to use these tubes... And the EF91s especially would likely sound terrible....


----------



## siles1991

Thanks to Acapella11,gibosi, and Audiofanboy for helping me out and answering my questions now I am waiting for my 4 sylvanias and 5 TS 6ah6wa. Once again thanks guy


----------



## mordy

The Tung Sol 6AH6WA tubes I have are from 1962 and 1963 and have rectangular slightly bent  ("streetcar") getters and they sound excellent. I have not been able to compare these tubes with the same with circular getters, but find it hard to believe that the shape of the getter makes any difference. The function of the getter is to assist in the getter flash (silver coating) inside the  top or the side of the tube in order to reduce oxygen and make for a harder vacuum. The getter has a one time function in the production of the tube and after wards it does not serve any function.
  However, it seems that later production tubes used circular getters, and perhaps a later date of manufacture would indicate some kind of improvement, although I doubt that as well.
   
  Regarding the 60's - 70's  6A2P Russian Svetlana heptodes (the symbol of Svetlana is a winged C) - did anybody try them yet?  Svetlana is a very old Russian factory and should make good quality stuff.
   
  In present times (2004), a US company bought the rights to use the name Svetlana in the US only, and new issue tubes under that name are not made by Svetlana but by an old Reflector factory. They also make modern reissue tubes under the name Electro Harmonix, Tung Sol etc.


----------



## hypnos1

Hope this post doesn't get duplicated but my first submission seems to have gone into thin air - very annoying..
   
  Hi mikelap.
   
  Sorry you didn't manage to get the Svetlanas - hope the others are OK though...
   
  On the subject of Svetlana/Siemens, the plot thickens even further - , on closer inspection my black-bottomed Siemens EK90s DO have very slight lateral ribs, the clear bottoms not. Also the blacks have plain grey plates, the clears silver/grey. Both of these traits seem to appear on the 2 Svetlanas I have seen - it would appear therefore that the Siemens in the white boxes are most probably Svetlanas...Whatever, they are excellent tubes and would be a good buy if the 'true' Siemens cannot be found (at a reasonable price).
   
  Hi mab (and anyone else interested in EK90/6BE6/EH90/6CS6/6A2P land - surely that's EVERYONE?!
   
  I suppose (obviously...) our different equipment gives us different results, even though I too have the HD650s.
   
  However, it looks as though my dilemma has finally come to an end  - have just received (finally) my Siemens EH90s and - **EUREKA**!!
  After just 15hrs burn-in (unstrapped), they sound (to me) somewhere mid-way between the Siemens EK90 1-7 strapped and unstrapped - the best of both worlds: the excitement is there along with the 'clean' airiness I liked unstrapped. Unbelievable. My Genesis 'DUKE' now has me in raptures, without need for compromise, and revisiting Cat Stevens's remastered Hard Headed Woman and Wild World is truly an amazing revelation - every different pluck/stroke/slap of plec on strings can be heard... Tremendous. Just a slight edge to his voice occasionally, but I'm sure further burn-in will sort that out (wouldn't worry if not). Plus a very slight hum that I haven't had before, but nothing to worry about. All in all, as you may have gathered, I think the journey may well have approached its end (for me?!). I cannot see what else could be added to this sound - that I would be able to discern anyway - so I look forward to what the 'big guns' make of these tubes.
   
  Cheers guys,
  (An enraptured masochist - but it's been worth the pain/expense!!)


----------



## hypnos1

Quote: 





mordy said:


> The Tung Sol 6AH6WA tubes I have are from 1962 and 1963 and have rectangular slightly bent  ("streetcar") getters and they sound excellent. I have not been able to compare these tubes with the same with circular getters, but find it hard to believe that the shape of the getter makes any difference. The function of the getter is to assist in the getter flash (silver coating) inside the  top or the side of the tube in order to reduce oxygen and make for a harder vacuum. The getter has a one time function in the production of the tube and after wards it does not serve any function.
> However, it seems that later production tubes used circular getters, and perhaps a later date of manufacture would indicate some kind of improvement, although I doubt that as well.
> 
> Regarding the 60's - 70's  6A2P Russian Svetlana heptodes (the symbol of Svetlana is a winged C) - did anybody try them yet?  Svetlana is a very old Russian factory and should make good quality stuff.
> ...


 
   
  Hi mordy,
   
  As per my previous post, I really do believe that my Siemens EK90s (and therefore also Acapella 11s) that came in white boxes and without the Siemens logo are in fact Svetlanas - either with or without black bottoms! And very good they are too(A11 has previously given comprehensive descriptions, esp on page 109, and further general comments by others in subsequent posts).
   
   HOWEVER, outclassed IMHO by the Siemens EH90s. But who am I to espouse?!...
   
  BFN
   
   
   
   
  BFN


----------



## gibosi

Quote: 





mordy said:


> The Tung Sol 6AH6WA tubes I have are from 1962 and 1963 and have rectangular slightly bent  ("streetcar") getters and they sound excellent. I have not been able to compare these tubes with the same with circular getters, but find it hard to believe that the shape of the getter makes any difference. The function of the getter is to assist in the getter flash (silver coating) inside the  top or the side of the tube in order to reduce oxygen and make for a harder vacuum. The getter has a one time function in the production of the tube and after wards it does not serve any function.
> However, it seems that later production tubes used circular getters, and perhaps a later date of manufacture would indicate some kind of improvement, although I doubt that as well.


 
   
  I have two pairs of TS 6AH6W(A) and two pairs of TS 6485:
   
  Both pairs of TS 6AH6W(A) sound excellent even though one pair is dated 1961, with D-getters, and the other is dated 1967, with O-getters.
   
  However, this is not the case with the two pairs of 6485. One pair (actually a slip of 5, and I tried them all), with D-getters, date unknown, do not sound good at all. However, the other pair, dated 1967, sound excellent. Why this is so, I do not know, but this is the reasoning behind my recommendation of O-getters for the 6485.
   
  Another bit of info, but I do not  know if it has any significance, is that the three pairs I have that sound excellent have a very short glass knob/tip on top, whereas the bad pair, have a longer, pointed glass tip. However, others in this forum have excellent 6485s with the longer, pointed glass tip, so it is likely of no consequence. Even so, if I ever need to go out and purchase another pair of 6485, I will look for the short glass knob and O-getters (as below) to increase the odds of getting a winner.


----------



## siles1991

can i know the difference between 6485 and 6AH6WA? I thought they were the same but just different designation based on country or something like that.


----------



## gibosi

Quote: 





siles1991 said:


> can i know the difference between 6485 and 6AH6WA? I thought they were the same but just different designation based on country or something like that.


 
  The 6485 is an industrial tube (as opposed to a consumer 6AH6 tube found in TVs and radios of that time) and the 6AH6WA is a military tube. In my experience, they appear to be the same tube, but who knows?


----------



## mordy

Interesting - could be that you got a bad pair. Did you contact the seller for an exchange? In general, I found most sellers to be very reputable and cooperative if something was amiss.
   
  On several occasions I have gotten the wrong tubes or individual broken tubes, and the sellers always tried to right things, either by sending replacements or giving refunds. (It does help to check out the tubes before you leave feedback...)


----------



## gibosi

Quote: 





mordy said:


> Interesting - could be that you got a bad pair. Did you contact the seller for an exchange? In general, I found most sellers to be very reputable and cooperative if something was amiss.
> 
> On several occasions I have gotten the wrong tubes or individual broken tubes, and the sellers always tried to right things, either by sending replacements or giving refunds. (It does help to check out the tubes before you leave feedback...)


 
   
  I'm not sure I could call them "bad"... They were very quiet, with no distortion, but they didn't sound good to me. The bass and treble were fine, but it was as if the mid-range had been sucked out of them. If it wasn't for the fact that everyone else at the time was raving about these tubes, I would have thought that this was just the 6AH6 sound, and it just wasn't for me. After all, not all the new tubes we tried were all that great, for example the 6AG5. Moreover, these are RF pentodes, not designed or intended for audio, so I don't think I could call them defective, they just didn't sound good. But again, everyone kept raving about their 6485, so I decided to buy another pair, with O-getters, and boy what a difference!


----------



## Nic Rhodes

where did you get the 'lesser' 6485s from Gibosi?


----------



## Acapella11

Quote: 





mordy said:


> Regarding the 60's - 70's  6A2P Russian Svetlana heptodes (the symbol of Svetlana is a winged C) - did anybody try them yet?  Svetlana is a very old Russian factory and should make good quality stuff.


 
  Hi Mordy, I have Svetlanas from October 1967. I haven't gibven a definitive opinion about them as I thought they may need some more birn in time but I haven't come by doing that so far. Anyways, they sound a bit bass biased with round treble but balanced overall. More later.


----------



## mordy

The plot thickens: Below are the Siemens EH90 tubes that several people ordered, including myself. We are trying to figure out who made these tubes. The indication FOREIGN must mean that they were made for Siemens in a different country.
  I asked the seller in Germany if he knew where they were made. This is his answer:
   
_[size=10pt]Hello.
 The tubes are not from Russia to 100%.
 It may be that they come from the former East of RFT.
 or from belgium - Valvo.
 The tubes come in all cases from Europe.[/size]_
   
  Can somebody tell me what East of RFT means? Anybody has a a suggestion now that Russia was ruled out?


----------



## gibosi

Quote: 





mordy said:


> [size=x-small]_Hello._[/size]
> _[size=10pt]The tubes are not from Russia to 100%.
> It may be that they come from the former East of RFT.
> or from belgium - Valvo.
> ...


 
   
  From Google:
   
  Most of the references to RFT that I see are in relation to double triodes. They appear to have a good reputation:
   
http://www.nostubestore.com/2011/01/rft-ecc8112at7-east-germany.html
   
  RFT ECC81 / 12AT7 East Germany
  Funkwerk/Neuhaus RFT tubes were made in East Germany throughout the cold-war era. Then many Eastern Block made tubes were bought through western contractors by NATO for military use. Such tubes often were labeled by those re-brander/contractors. Our stock tubes have such labels as RFT, Tungsram, Orion, Telefunken, Haltron, Glotron etc.  These are low noise and low microphonic tubes because of their rugged construction. They sound great and very good for guitar amps!!!
   
  As to Russian tubes... Perhaps they all have sharp, pointed rhodium plated pins and saucer getters? But I do not know....
   
  And if these are Valvo, then it seems to me that the standard Philips/Mullard tube codes should be etched into these tubes....


----------



## gibosi

Quote: 





nic rhodes said:


> where did you get the 'lesser' 6485s from Gibosi?


 
  I have checked my records, but unfortunately, I can't find anything regarding this purchase. (Obviously, I need to improve my record keeping system!) Moreover, I just searched eBay, but do not see anything that looks familiar, so I would guess that this listing is sold out.... And that wouldn't be surprising as I bought them some 4 or 5 months ago....


----------



## mordy

Ok, found the answer to East RFT:
   
  "Funkwerk/Neuhaus RFT tubes were made in East Germany throughout the "Cold War" era. Various resellers have relabeled these tubes over the years. It is not uncommon to find these tubes labeled as Orion, Tungsram, TELEFUNKEN (without the diamond stamp on the bottom), Haltron, and Glotron to name but a few. "
   
  What follows is a poor translation (blame Google) of some of the history of RFT which was started in the 40's:
   
  "Tube production
 RFT EF80-produced electron tube

 An extensive chapter is the former RFT electron tube production in the GDR in the RFT tube stations, the actual nucleus of the RFT radio production. Radio tubes were traditionally in Berlin (WF) in Berlin-Weissensee (Loewe-Opta/Phonetica) and later manufactured in Mulhouse and Neuhaus and the Funkwerk Erfurt in Thuringia, but also at other locations. In Mulhouse, there were many skilled workers of the C. Lorenz AG, which operated a tube factory during the war in this region. Thus, the professional experience of former times were used for the recommencement of the tube production in Mulhouse. When the production of electronic and specialty tubes in Western Europe had to be shut down - only recently built the Telefunken tubes themselves - were almost all electronics companies still need tubes in the GDR produced works. The OSW (Oberspree work) Berlin (later WF works for television electronics in Ostend in Berlin-Oberschoeneweide), until the final closure in 2005 belonging to Samsung, introduced the EL ago 34 (dimple top), a post-war development of the Philips line. Later, the production was moved to Mühlhausen and sold by Philips expertise in the West. (China, Soviet Union, Yugoslavia competitors still make these and other tubes.)"
   
  Or the tubes could be Valvo tubes made in Belgium.....
   
  Confusing, eh........


----------



## siles1991

Well today I did a reallly verrrry quick A & B test with my Voshkod 6ZH1P-EV and the stock GE tubes, was getting ready for college so was a bit of a rush. Thought when I tried both of them out the first thing I noticed is that the voshkods were more energetic and aggressive almost forward compared to the GE which to me felt laid back and smooth. It didn't have that "in your face" feeling the voshkods had.
   
  Was wondering if anyone shares the same opinion, all I did was listen to the same song once each tube and tried to make out the difference as much as possible so take it with a grain of salt.


----------



## sssboa

Quote: 





siles1991 said:


> Well today I did a reallly verrrry quick A & B test with my Voshkod 6ZH1P-EV and the stock GE tubes, was getting ready for college so was a bit of a rush. Thought when I tried both of them out the first thing I noticed is that the voshkods were more energetic and aggressive almost forward compared to the GE which to me felt laid back and smooth. It didn't have that "in your face" feeling the voshkods had.
> 
> Was wondering if anyone shares the same opinion, all I did was listen to the same song once each tube and tried to make out the difference as much as possible so take it with a grain of salt.


 
  Voshkod ef95 type from the 80's have less soundstage than most American tubes also sound less warm but have much more detail, crispness and refinement, they are my favourite of all types, brands and models for Little Dot MK. But the GE JAN would have the second place on my list among EF95 and 3rd in general after EF92 Mullard M8161. I wasn't too impressed with 1950s Tung-Sols that have biggest soundstage but are the worst in detail department., RCA JAN with black plates had similar detail to Voshkod but warmer and these were the only ones with smaller soundstage than Voshkod among American/Canadian EF95. The warmth and bass monsters are EF95 Mullard M8100. I listen on DT 880 600 ohm and through Dr Meier's dac with crossfeed on.


----------



## inphu510n

Indeed the late 70's 6J1P-EV are some of the best pure EF95 tubes available for the LD amps. The "-EV" bit is important as I accidentally ordered a pair of 6J1P and found them slightly lacking. Not bad but just not the same.
  It bears repeating that those tubes require about 120hrs of burn in before they become what everyone raves about. Initially they are a bit more bright and clinical but after burning in this tames and the sound stage gets even bigger.
  One note that gets lost frequently is that the spelling is "Voskhod" and not "Voshkod".


----------



## sssboa

Quote: 





inphu510n said:


> Indeed the late 70's 6J1P-EV are some of the best pure EF95 tubes available for the LD amps. The "-EV" bit is important as I accidentally ordered a pair of 6J1P and found them slightly lacking. Not bad but just not the same.
> It bears repeating that those tubes require about 120hrs of burn in before they become what everyone raves about. Initially they are a bit more bright and clinical but after burning in this tames and the sound stage gets even bigger.
> One note that gets lost frequently is that the spelling is "Voskhod" and not "Voshkod".


 
  I don't know why the 70s would be better than 80s, I guess it would be rather the other way. Soviet economy was not market economy so it did not follow the trends in the west as the dwindling demand was not a factor and costs did not matter for the military. The 80s tubes look better for sure and have pins covered, some with gold and mine with something that looks like platinum but I'm not sure what it is. Spelling is Восход.


----------



## jaywillin

Quote: 





audiofanboy said:


> Those are heater wires you see between the tube sockets, nothing to do with strapping. You'll want to follow gibosi's suggestions about that.
> 
> And yes, people, forget about the silly 6ak5 tubes... There are many other better and cheaper tubes out there, seriously...


 

 such as ?? what would be the best route to take ? leave it, go with ef95's, go 408's ?? don't mind spending a little on tubes, but don't want to go crazy either !


----------



## Oskari

sssboa said:


> Spelling is Восход.




Or Voskhod, in English transliteration.


----------



## gibosi

Quote: 





jaywillin said:


> such as ?? what would be the best route to take ? leave it, go with ef95's, go 408's ?? don't mind spending a little on tubes, but don't want to go crazy either !


 
   
  As I mentioned in a previous post, my best advice is to pick up some inexpensive American heptodes and give them a try: Sylvania 5915, RCA 5915 or IBM 1680 (made by RCA) would be a good start. The European E91H or 6687 (the same tube, with either or both numbers written on the glass) are also relatively easy to find (To the best of my knowledge, all E91H/6687 were manufactured in the Philips factory located in Heerlen, Holland, regardless of brand.)
   
  Leave your LD in the EF95 setting and give them a try. If you are willing to try strapping, many have reported that these tubes sound very good, but a bit different. strapped 1-7.


----------



## Audiofanboy

Quote: 





jaywillin said:


> such as ?? what would be the best route to take ? leave it, go with ef95's, go 408's ?? don't mind spending a little on tubes, but don't want to go crazy either !


 

 Page 77 has _everything_ you seek.


----------



## Oskari

gibosi said:


> And if these are Valvo, then it seems to me that the standard Philips/Mullard tube codes should be etched into these tubes....




That should be the case. Valvo was Philips Germany, so to speak.

The Belgian manufacturer was MBLE. Their own tube brand was Adzam. MBLE-made tubes should also have the Philips codes.


----------



## Oskari

mordy said:


> We are trying to figure out who made these tubes.
> 
> _[SIZE=10pt][COLOR=000]The tubes come in all cases from Europe.[/COLOR][/SIZE]_




Is that a certainty?

Japan could be one possible source: http://www.ebay.com.sg/itm/6CS6-Vacuum-Tube-Haltron-Japan-NOS-McIntosh-MR-65B-Amp-/200478169334#ht_500wt_729. Information is difficult to come by, though.


----------



## mordy

I am just trying to find out who manufactured these tubes. The quote in italics is from the seller I got mine from in Germany.
   
  If we can find out who made these tubes it may be possible to find sources where to buy them under other names at moderate prices. The few NOS tubes available now sell for around $25/pair including shipping.


----------



## jaywillin

Quote: 





audiofanboy said:


> Page 77 has _everything_ you seek.


 
   
   
  Quote: 





gibosi said:


> As I mentioned in a previous post, my best advice is to pick up some inexpensive American heptodes and give them a try: Sylvania 5915, RCA 5915 or IBM 1680 (made by RCA) would be a good start. The European E91H or 6687 (the same tube, with either or both numbers written on the glass) are also relatively easy to find (To the best of my knowledge, all E91H/6687 were manufactured in the Philips factory located in Heerlen, Holland, regardless of brand.)
> 
> Leave your LD in the EF95 setting and give them a try. If you are willing to try strapping, many have reported that these tubes sound very good, but a bit different. strapped 1-7.


 

 thanks guys, all your input and advice is very much appreciated !!
  now i've got some more reading/learning  and searching/buying to do
   
  earlier this morning, before i had read the above,
 1960s RCA 6AK5 5654 EF95 MATCHED PAIR


----------



## siles1991

How do I check what year my voskhod is from? Its OTK1 with number 47 in a diamond. It has something written like 6 STAR(star shaped thingy) 1 N(its like an upside down U) so its like 6*1N-EB
   
  Then there are numbers numbers 04-87 so are these from april 1987? just rough guess xD


----------



## Oskari

Quote: 





siles1991 said:


> How do I check what year my voskhod is from?
> 
> Then there are numbers numbers 04-87 so are these from april 1987? just rough guess xD


 
   
  That's it!


----------



## siles1991

Quote: 





oskari said:


> That's it!


 
  aight thanks  sad i didnt get the 70's one...wonder how it would sound compared to the 80's one I have


----------



## Oskari

Quote: 





mordy said:


> I am just trying to find out who manufactured these tubes. The quote in italics is from the seller I got mine from in Germany.


 
   
  I got that. I'm curious of their origin myself.


----------



## mordy

One of the things about the tube mystique is the unavailability or difficulty of finding information. There are tubes from major manufacturers such as Tung Sol, GE and Sylvania etc where we don't know how to decipher the date codes. Not to speak about the OTK codes on the Russian tubes....
  In addition, although many factories existed for decades virtually no information is available about their history and achievements.
  Then we have the re-branding issue, etc etc.
   
  All of this makes tube rolling and tube collecting more interesting and more fun, at least for me.
   
  "Det dunkelt sagda ar det dunkelt tankta."


----------



## mordy

Hi Gibosi,
   
  Since you seemed to be skeptical about the features on my VISTA computer (post #1876) I am going to try to explain a new feature from Google that I just discovered, all in the interest of furthering our understanding of vacuum tubes.
  Sometimes the literature is in a foreign language. Now, in addition to self detecting, automatic translation, Goggle Translate can play back the material in a vocalized version, complete with the native intonation.
   
  In my last post to Oskari, I quoted something in a foreign language that he should be familiar with.
   
  "Det dunkelt sagda ar det dunkelt tankta."
   
  http://translate.google.com/
   
  Highlight and copy/paste the material. Then click on Google translate and put it inside the translation box. Click on the button "Detect Language." The translation appears. On the bottom right in both the original and translated box is a speaker symbol.
  By clicking on these symbols you can hear it in English, and in the native language. What impressed me was that the intonation was correct. Google does not always come up with a fully intelligible translation, but it may help to hear it being read.
   
  The correct translation is "What is unclearly said is unclearly thought" .
   
  Sorry for the digression, but this could come in handy next time you want to read a Chinese website about the vacuum tubes.


----------



## hypnos1

Quote: 





mordy said:


> I am just trying to find out who manufactured these tubes. The quote in italics is from the seller I got mine from in Germany.
> 
> If we can find out who made these tubes it may be possible to find sources where to buy them under other names at moderate prices. The few NOS tubes available now sell for around $25/pair including shipping.


 
   
  Hi mordy.
   
  From the look of those 'Siemens EH90' tubes compared to mine with the Siemens logo, it would appear there is quite a difference in quality of construction. Based upon what mine are delivering - after 30+hrs burn-in - they are performing better than any others I have tried : TS6485; Sylvania Gold Brand 5750(6BE6); Telefunken EH900S; Siemens EK90(probably Svetlana 6A2P). As I mentioned in previous posts, they are a wonderful combination of the EK90s strapped and unstrapped. They have totally blown my mind...
  I would suggest in this particular case it is well worthwhile to pay the extra for the genuine article, before they too disappear from the scene. They are so good that even second best is false economy, let alone third...or fourth...
  But, of course, the final(?) verdict on these is yet to be arrived at by the Masters of this forum. I can only hope they have similar findings to my own - am awaiting with anticipation!...
   
  All the best,
  H1


----------



## gibosi

Quote: 





mordy said:


> Hi Gibosi,
> 
> Since you seemed to be skeptical about the features on my VISTA computer (post #1876)


 
   
   I wasn't skeptical at all..... But very frankly, I don't see the "slider on the left" that you refer to. So I simply assumed you were running a different operating system on your computer than I, or perhaps you were using a different browser.... I just didn't know....
   
  That said, even though I don't see a slider (I am running Windows 7 with Chrome) I just tried the Control key-mouse scroll wheel while viewing a picture in eBay. And indeed it works! Thanks! 
   


mordy said:


> ...........I am going to try to explain a new feature from Google that I just discovered, all in the interest of furthering our understanding of vacuum tubes.
> Sometimes the literature is in a foreign language. Now, in addition to self detecting, automatic translation, Goggle Translate can play back the material in a vocalized version, complete with the native intonation.
> 
> In my last post to Oskari, I quoted something in a foreign language that he should be familiar with.
> ...


 
   
  While I know and have used google translate, I didn't know about this vocalization function. Another great find!


----------



## mordy

Hi H1,
   
  Thank you for your thoughtful advice. In a couple of days I'll be back from vacation and will again start evaluating the tubes that have arrived. I do like the Siemens EH90 that I have very much, but I like other heptodes as well.
   
  Since it seems that these tubes need a fair amount of time to perform at capacity, it will take a little time to sort things out.
   
  Having watched Ebay for tubes for a couple of years I have come to the conclusion that there will always be new offerings, and with a little patience you will be able to get the tubes you want at the right price.


----------



## gibosi

Quote: 





hypnos1 said:


> From the look of those 'Siemens EH90' tubes compared to mine with the Siemens logo, it would appear there is quite a difference in quality of construction. Based upon what mine are delivering - after 30+hrs burn-in - they are performing better than any others I have tried : TS6485; Sylvania Gold Brand 5750(6BE6); Telefunken EH900S; Siemens EK90(probably Svetlana 6A2P). As I mentioned in previous posts, they are a wonderful combination of the EK90s strapped and unstrapped. They have totally blown my mind...
> I would suggest in this particular case it is well worthwhile to pay the extra for the genuine article, before they too disappear from the scene. They are so good that even second best is false economy, let alone third...or fourth...


 
   
*"I would suggest in this particular case it is well worthwhile to pay the extra for the genuine article"*
   
  Ah, but this is crux of the problem, How to recognize the *genuine article*. We are still not sure which ones are genuine and which are not..... Which were manufactured in the Halske factory and which were manufactured elsewhere. And where is "elsewhere"... And to the heart of the matter.. Which tubes sound the best?
   
  By the way, have you posted a picture of yours?


----------



## Oskari

mordy said:


> One of the things about the tube mystique is the unavailability or difficulty of finding information.




Even photos can be difficult to find, but I managed to find this barely usable photo of what appears to be a pair of Toshiba EH90s, with octagons! Could this be it?


----------



## mordy

Good try, but the getter mounting on top of the mica on my Siemens tubes does not have a bar across (look at left tube).
   
  Battre lycka nasta gang.


----------



## Oskari

mordy said:


> In my last post to Oskari, I quoted something in a foreign language that he should be familiar with.
> 
> "Det dunkelt sagda ar det dunkelt tankta."




I'm sorry. Many of us Finnish-speaking Finns don't really "support" the Swedish language, which is a domestic language in Finland, even though we must learn it at school ("tvångsvenska"). :rolleyes: But you shouldn't leave out the dots: "Det dunkelt sagda är det dunkelt tänkta." 

(I understood the words, sort of, but didn't really get the twist of it.)


----------



## mordy

This tube looks almost identical, except that the plate is not ribbed.


----------



## Oskari

mordy said:


> This tube looks almost identical, except that the plate is not ribbed.




... and the nip and the pins are all wrong...


----------



## MIKELAP

Got those today Siemens EH 90 from Germany  same tubes as mordy post #1937 page 130


----------



## mordy

The quote was just a joke - whatever you write is very clear and appreciated. - I don't have the dots on my keyboard and never bothered to install the Swedish characters on my computer.
   
  Anyhow, so far I am voting for RFT as the manufacturer of the Siemens tubes.
   
  http://www.ebay.com/itm/EH90-6C6S-RFT-HEPTODE-TUBE-NOS-in-BOX-/250640179082?pt=Vintage_Electronics_R2&hash=item3a5b519f8a


----------



## Oskari

mordy said:


> Good try, but the getter mounting on top of the mica on my Siemens tubes does not have a bar across (look at left tube).




I think you see the octagon, not a bar. Otherwise, I don't know what bar you're talking about.


----------



## hypnos1

Quote: 





gibosi said:


> *"I would suggest in this particular case it is well worthwhile to pay the extra for the genuine article"*
> 
> Ah, but this is crux of the problem, How to recognize the *genuine article*. We are still not sure which ones are genuine and which are not..... Which were manufactured in the Halske factory and which were manufactured elsewhere. And where is "elsewhere"... And to the heart of the matter.. Which tubes sound the best?
> 
> By the way, have you posted a picture of yours?


 
   
  Hi gibosi.
   
  Yes indeed : wherefore art thou genuine tube?!  The various permutations of manufacturer (and even within the same one!) is mind-boggling, to say the least.
   
  With regard to Siemens, I am wondering if we are on fairly safe ground if the Siemens logo (as well as name) is on the tube, plus the yellow & blue with orange end cap box?
  Especially if, like mine (see photo), Siemens& Halske is written on the bottom of the box....
   
  Whatever, all I can say about mine is that with 40hrs burn-in now, everything I have mentioned in previous posts is holding firm - if not even firmer. Sensational - for me anyway.
   
  I can only hope others have the same experience - with similar tubes, or from 'elsewhere'!
   
  GOOD LUCK everyone...


----------



## Oskari

hypnos1 said:


> With regard to Siemens, I am wondering if we are on fairly safe ground if the Siemens logo (as well as name) is on the tube, plus the yellow & blue with orange end cap box?
> Especially if, like mine (see photo), Siemens& Halske is written on the bottom of the box....




That's what their brand looked like at the time. A positive sign, but hardly a guarantee of origin. They did away with the SH logo when Siemens & Halske was merged with Siemens-Schuckertwerke and Siemens-Reiniger-Werke to form Siemens AG in 1966.


----------



## Acapella11

Just a quick info with respect to Svetlana 6A2P and Siemens EK90 (black bottom, saucer getter): They do not sound the same. Hence, one would not be a substitute for the other.
   
  Otherwise, I changed something on my system and have to now go through tubes again. Also, I am suffering from heptoditis (= the choice of many good sounds), so I decided to not rush it but rather get used to them and come a bit delayed with a "more definitive" opinion.
   
  I agree that focussing on one mode of operation (unstrapped that is probably) will make reviewing tubes easier. Every reviewer has anyways the option to try different modes "in secret" if he/she wishes and include information about them, if useful.
   
  Good luck rolling everyone!


----------



## mordy

My Tesla 6H31 heptodes arrived after 2 weeks shipping time from Lithuania. They came exceptionally well packaged in a big box with layers and layers of rainbow colored foam strips.
	

	
	
		
		

		
		
	


	




They are on slow simmer for 40-50 hours to burn in.
   
  Because I had the 1-7 straps in place, they are burning in this way. _Would it be any advantage burning them in unstrapped?_ Maybe more of the internals will be activated when you burn in a tube unstrapped?
  As I understand it the burning in process burns up unwanted gasses and impurities. However, there must be more to it, since some tubes require over 100 hours to burn in. Perhaps different materials in the tube need various times to stabilize for optimum performance.


----------



## mordy

Here is an early update on my Tesla 6H31 (6BE6) from December 1958 after 9 hours of burn in on EF95 1-7 strap:
   
  Very strong and detailed mid bass. The sound stage is wide but the instruments are not portrayed as totally separate but more like an organic whole. At the same time these tubes astound me with their portrayal of micro details - I suddenly hear new nuances in familiar recordings that I did not hear before.  The treble is also very detailed. The mid range is starting to sound very sweet.
   
  They sound a little bright but that could be a function of the 1-7 strap - will try later with no strap. Overall very pleasing and engaging tubes. Who knows, maybe a top tier tube....
   
  The date code on the tube is SH (12/58). Reminds me of a new brand of pre-amplifiers whose name also starts on Sh... I take affront that somebody would name it as such and don't think it's funny. (How does your sh.... sound?) A new low in the music world?
   
  From their home page:
   
And yes, that is our name. "And yes, it’s pronounced exactly like you think.
  I
Or, well, no. Yep, Schiit is our name. As in “Hey man, that’s some really cool Schiit.” Or, “We like music and Schiit.”
   
   
  Would not buy something with such a name....
an we show you some Schiit?


----------



## siles1991

Received my valvo tubes. Codes 3L8 and cutoff 48D3. How should I use them hmmm I have some left over spc 26awg about 7-8 strands would those work for the socket mod?


----------



## siles1991

just put the valvo's in....I prefer it over the voskhods. Not too bright and and forward/aggresive. It's very smooth but lacks a bit of sparkle.

On another note: Guys I have michael jackson's discography in FLAC and whenever I hear the song Billie Jean the Snare drums are very piercing to my ears. Any reason to this? Only this particular song gives me this problem. It happens even from Youtube videos. It's like the snare drums are right next to my ears and its punching me in the ears.


----------



## inphu510n

Guys, thanks for the recent heptode business. I'm currently listening to the IBM 1680's and really liking them. I'm finding their highs more refined than the 6485's with more bass/sub bass presence. They're currently in straight EF95 mode. I'll try the 1-7 strap after they've cooked a bit.
  One thing I'm a bit worried about is that one of the tubes has an almost imperceptible getter flash. The other tube has a more substantial flash but considering these were somewhat "custom" tubes and that they have the old D getters I'm wondering if this is just me being paranoid. Was the vacuum that hard?
  I've also noticed that there's a slight, very slight buzz coming from that tube that generally goes away if I tap on the tube.
   
  I've got some Telefunken EH900S on the way too.


----------



## Audiofanboy

Quote: 





inphu510n said:


> Guys, thanks for the recent heptode business. I'm currently listening to the IBM 1680's and really liking them. I'm finding their highs more refined than the 6485's with more bass/sub bass presence. They're currently in straight EF95 mode. I'll try the 1-7 strap after they've cooked a bit.
> One thing I'm a bit worried about is that one of the tubes has an almost imperceptible getter flash. The other tube has a more substantial flash but considering these were somewhat "custom" tubes and that they have the old D getters I'm wondering if this is just me being paranoid. Was the vacuum that hard?
> I've also noticed that there's a slight, very slight buzz coming from that tube that generally goes away if I tap on the tube.
> 
> I've got some Telefunken EH900S on the way too.


 

 Mine have the same very light getter flash on one tube, and still pretty light on the other one anyway, so I wouldn't worry about it (I believe the historic change from D to O-getters was mainly meant to get more uniform and well flashed, well, getter flashes on tubes; all my tubes with D-getters have pretty irregular or "pattern-less" getter flashes, whereas my O-getter tubes usually look alike).
   
  About the buzz: clean the pins, thoroughly (sand paper, small knife, ... any kind of good _mechanical _cleaning). Those tubes are nice, but are 60 years old and came to me quite dirty -both glass _and _pins- so I cleaned everything before I even dared to put them in the amp, which I hardly ever do.


----------



## inphu510n

audiofanboy said:


> Mine have the same very light getter flash on one tube, and still pretty light on the other one anyway, so I wouldn't worry about it (I believe the historic change from D to O-getters was mainly meant to get more uniform and well flashed, well, getter flashes on tubes; all my tubes with D-getters have pretty irregular or "pattern-less" getter flashes, whereas my O-getter tubes usually look alike).
> 
> About the buzz: clean the pins, thoroughly (sand paper, small knife, ... any kind of good _mechanical_ cleaning). Those tubes are nice, but are 60 years old and came to me quite dirty -both glass _and_ pins- so I cleaned everything before I even dared to put them in the amp, which I hardly ever do.




Hah ok thank you for the info. The top of that one tube is almost totally clear which is odd when compared to the amount of flash in something like a Russian 6N6P.

I'm pretty sure I cleaned the pins well. I used the back of an xacto knife to scrape them clean because WOW they were dirty. Some of the most filthy pins I've seen.

I typically clean the pins in this manner for most of the tube types I try out. It's a PITA to clean them like this because it's 14 pins every time!
I've actually tried soaking the pins in Coca Cola. Hey it dissolves egg shells right??? That worked somewhat but not enough for my taste. Something more corrosive would be needed...

Any how, thanks for the advice. I'll check to make sure they're totally clean.


----------



## mordy

Siles 1991,
   
  Sounds like you have  a badly recorded tune. We all have such recordings where something does not sound right or strange....
  
  Inphu510n,
   
  If the tube sounds all right I would not worry about the getter flash. I have seen some early tubes 6AK5 that did not have a visible getter flash and the top of the tube was completely clear. They worked just fine. The same goes for the heater. Sometimes it is visible in one tube and not in the other, but it only has to do with how it was assembled. If the tube works, all is well.
   
  Also got the shopworn dirty 1680 tubes. Usually I just take my old little pen knife and do a cursory scraping of the pins. IMHO the contact areas for the pins are much smaller than the entire pin, and you need very a very small contact area for the tube to work. Just think of the tiny area the jumpers occupy. If the first cleaning does not help, I'll try harder the second time. BTW, I had a 6N6Pi power tube that I thought had stopped working. Luckily, I did not throw it away. A year later I thought of cleaning/scraping it and got it going. Despite all the hype about expensive chemicals, mechanical cleaning works the best.


----------



## gibosi

Tracking down the origins of the various Siemens EH90 is proving to be an interesting puzzle. I have learned that at least some of Siemens EH90 with smooth plates and squarish holes were made by Mullard in their Blackburn factory. If you have a pair of these, check on the side of the glass, near the bottom, for a sequence of three or four alphanumeric characters, beginning with the letter B. For example, my smooth plate Siemens EH90 have the following code: B9F, which indicates the Blackburn factory, June, 1959. In the two samples I am aware of, these codes are very faint, so it may take some patience and a good magnifying glass to find them.
   
  But I have also learned that smooth-plated Siemens EH90 with "Made in Germany" printed on the glass exist! .....So we still have much to learn before the mysteries of the Siemens EH90 are finally revealed to us....


----------



## jaywillin

got the first pair of new tubes today, a RCA 6AK5 5654 SHARP CUT OFF PENTODE, not that i know a whole lot about them
  other than they sound very good to me
  i also have coming in a pair of RCA 5915 with black plates, multiple mica supports, upper ring getter, and i don't know to much what all that means, other than it was suggested .


----------



## Audiofanboy

Quote: 





oskari said:


> That should be the case. Valvo was Philips Germany, so to speak.
> 
> The Belgian manufacturer was MBLE. Their own tube brand was Adzam. MBLE-made tubes should also have the Philips codes.


 
   
  Quote: 





gibosi said:


> Tracking down the origins of the various Siemens EH90 is proving to be an interesting puzzle. I have learned that at least some of Siemens EH90 with smooth plates and squarish holes were made by Mullard in their Blackburn factory. If you have a pair of these, check on the side of the glass, near the bottom, for a sequence of three or four alphanumeric characters, beginning with the letter B. For example, my smooth plate Siemens EH90 have the following code: B9F, which indicates the Blackburn factory, June, 1959. In the two samples I am aware of, these codes are very faint, so it may take some patience and a good magnifying glass to find them.
> 
> But I have also learned that smooth-plated Siemens EH90 with "Made in Germany" printed on the glass exist! .....So we still have much to learn before the mysteries of the Siemens EH90 are finally revealed to us....


 

 OK, this Siemens puzzle is getting more and more complicated lol...
   
  I just got my "Siemens" EH90 tubes, 3 tubes (playing it safe from now on), and also a pair of "Pope" "Made in Holland" EH90.
   
  Let's start with the Siemens tubes. First, some pictures:
   
  The two identical Siemens tubes, Siemens logo, 3-digit number on top, *factory code LOA*.
   

   
  One of the two tubes above on the left, on the third Siemens on the right. They look identical, _but they are not_. The tube on the right is *factory coded B4F3*, and has grid 2 and 4 soldered to same pin at the base, whereas the tube on the left has g2 and g4 tied together by a metal plate at the top. Getter flash and nub are also different, and they are a few extra minute differences if you look closely. Oh, and of course, you can't miss the "Made in Germany" sign on the right tube.
   

   
  The same tubes, different angle, _still different_. See that metal plate that ties g2 and g4 towards the top on the left tube, and lack thereof on the right tube?
   

   
  The tube boxes. The two left ones are from the LOA codes tubes, the last one on the right is from the B4F3 coded tube. That last box has a different tag on it; you can't see it here, but it says "hexode" where the others say "heptode". Because the two screen grids aren't tied the same way? _Who knows..._
   

   
  Same order, different angle. Last box looks like it has a slightly different "shine" to it, but it just doesn't seem that relevant at this point.
   

   
  Basically, the "L" coded pair is a M.B.L.E Mazda, Brussels Belgium, manufactured pair, and the "B" coded tube is a typical Mullard Blackburn manufactured tube (come on, you saw _that_ coming, right? Those tubes _screamed_ Mullard the second I saw them. The Mazda Belgium are a bit a of surprise though).
   
  So, essentially Siemens labeled but Philips group production. The plot thickens yet again. I think I saw a "B" on at least one of Hypnos' tubes as well -and no metal sheet at the top- so I'm curious whether anyone else ended up getting the same Mazda Belgium tubes I got (which you could probably find labeled Adzam much more easily btw).
   
  From the 5 minutes I took to test the Belgian tubes, I can say they sound _dramatically_ different from the supposedly genuine Siemens _EK90_ I have. If I were to grade them on the Euro-Tubiness Continuum (copyright gibosi and me lol), I would put them way over towards the UK-Mullard end. These are warm and tubey all right, but not in the usual Mullard way. It's weird, I need some more testing to get better impressions, obviously. What I can say is that these tubes immediately transported me in what seemed like a separate musical dimension the second I lit them up and put my headphones on. You like _ambiance_? You'd find these interesting. I'll wait a few hours to give more objective impressions; after all you know the saying: _all heptodes sound good_. (except the Brimar perhaps)
   
  Next, and yet untested, the Pope EH90. OK, I'll cut to the chase: these are not "Made in Holland"... The Mullard Blackburn factory codes kind of leap at you really, it's almost sad... At least, I'll be able to compare these, Mullards, to the, M.B.L.E. Mazda, Siemens.
   

   
  The standard boxes these came in, labeled with the same shameless lie that is written on the tubes.
   

   
  There is one element that strikes me here; it is that three out of five of these tubes claim to be made somewhere but are evidently not! Now, I do have to ask myself if it really is a bold lie in each case, or if the factory codes only show where _a part_ of the manufacturing process was conducted, and not where the tubes were necessarily assembled (if I recall, Philips codes, and perhaps all codes, only tell you where the "pumping process" occurred; so tube A and B could both have Blackburn codes, but one could have been assembled in factory XYZ and "pumped" in Blackburn, while the other could have been assembled and pumped out in Blackburn...? Or not. But I'd be curious to know.).
   
  Interestingly, I could swear I'd read something about Pope tubes being Philips Holland; and I found this, quoted below:
   
  "[size=xx-small]Very unusual label I found on a tube in Holland. Pope means "Productie Overschot Philips Eindhoven" = surplus production from Eindhoven.[/size]"


----------



## MIKELAP

Received EF95 T0 EF91-92 socket adaptors today unfortunatly duds again they dont work you figure they'd figure out a way to test them before shipping them out but they haven't let me down yet so patience patience.


----------



## gibosi

As some of you might remember, I initially received a mismatched pair of Siemens EH90, one with ribbed plates and the other with smooth plates. I contacted the vendor and he offered to send me the mates to these tubes such that I would have two pairs. Well, I received the package today, and now it seems that I have four Siemens EH90 and none of them match!! lol It seems obvious to me that the vendor realized he had sold out of tubes that matched mine, because he also sent, free of charge, an extra Telefunken EH90 and a matching pair of Valvo EH90, so I still recommend him. He tried to make things right.
   
  A nice pair of Valvo EH90, Mullard/Blackburn codes, 1967
   

   
  And here is my Siemens EH90 "Collection" to date:
   
  A "slightly" mismatched pair of Siemens EH90, Mullard/Blackburn codes, 1959 (B9F) and 1964 (B4K5). And the lie, "Made in Germany" is written on the 1964 tube. 
   

   
  And a completely mismatched pair. Note that the design of the getter attachment to the support rod is different, as well as the ribs, holes and getter splash.
   

   
  Also note the metal strap tying g2 and g4 just below the getter, left side, on the right tube. Whereas, there is no such strap on the left tube as g2 and g4 are soldered to the same pin at the base.
   

   
  With some luck and patience I hope to find suitable mates for my two ribbed Siemens. And the search for a pair of "real" Siemens EH90 continues.... lol


----------



## mordy

Here is an excellent film from the 50's showing how vacuum tubes are being made in the Mullard Blackburn factory. After the 22 min mark the film shows how tubes are pumped etc. Based on the complex manufacturing process it seems unlikely to me, IMHO, that partially assembled tubes would be shipped for final processing somewhere else. Thus the plot further thickens about the origin of the Siemens tubes and the labeling of country of origin.
   
  This film is a new and very recent post on Youtube and has only been watched by a handful of people so far.
   
  http://www.youtube.com/watch?v=5WCWejeRR_s


----------



## jaywillin

here's what's in the little dot now, while i wait on the rca 5915's


----------



## TrollDragon

Quote: 





mordy said:


> Here is an excellent film from the 50's showing how vacuum tubes are being made in the Mullard Blackburn factory. After the 22 min mark the film shows how tubes are pumped etc. Based on the complex manufacturing process it seems unlikely to me, IMHO, that partially assembled tubes would be shipped for final processing somewhere else. Thus the plot further thickens about the origin of the Siemens tubes and the labeling of country of origin.
> 
> This film is a new and very recent post on Youtube and has only been watched by a handful of people so far.
> 
> http://www.youtube.com/watch?v=5WCWejeRR_s


 
  Great watch and very interesting, I bet that was a nice safe plant to work in...


----------



## Acapella11

No information as to from where but what for is visible on my Siemens EK90 (here): A little eagle with 933 written in between the wings indicates that these tubes were produced for the German Army.


----------



## siles1991

I have SPC cable with only 7-8 strands would that suffice for the jumper?


----------



## gibosi

Quote: 





siles1991 said:


> I have SPC cable with only 7-8 strands would that suffice for the jumper?


 
   
  The smaller the better, so this should work splendidly!


----------



## hypnos1

Quote: 





acapella11 said:


> Just a quick info with respect to Svetlana 6A2P and Siemens EK90 (black bottom, saucer getter): They do not sound the same. Hence, one would not be a substitute for the other.
> 
> Otherwise, I changed something on my system and have to now go through tubes again. Also, I am suffering from heptoditis (= the choice of many good sounds), so I decided to not rush it but rather get used to them and come a bit delayed with a "more definitive" opinion.
> 
> ...


 
   
  Hi A11.
   
  Thanks for putting me right on this matter - are your Svetlanas IDENTICAL to the Siemens in appearance? It is a strange coincidence that, from what I saw on the web photos, the black-bottomed tubes should have the same slight ribbing and plain grey plates; the clear- bottomed smooth, silver/grey plates. Weird! Ah well, these Siemens tubes really are giving us the runaround, ya?!! Thankfully, my Siemens EH90s have usurped them anyway...more on those later (to add to the already escalating confusion).
   
  The saga continues...


----------



## mordy

Maybe I am not using the highest quality jumper wires, but it looks to me that little fragments break off and end up inside the pin holes. A little piece broke off when I pulled out the tube and ended up lying on top of the tube socket. At first I thought I could pick it up with a magnet but that did not work.   Was able to pick up the little strand with tweezers.
   
  The jumper will work fine even with just very few little strands.


----------



## mordy

Hi A11,
   
   
  From post 1858:
   
  "I have saved the Russian 6A2P pictures and a surprise for later."
   
  Did not hear about the surprise yet - did I miss something?
   
  BTW, on your excellent chart, which I refer to every day, why don't you add the _EF95 + 6/7 socket wire modification = EF92 setting_ for those of us who hate to change the jumpers underneath the LD MKIII?
   
  Also, if you could change the spacing between the columns so that the first three columns have more space between them for clarity. (Or could it be my computer that bunches the three first columns too close?)


----------



## MIKELAP

Quote: 





mordy said:


> Hi A11,
> 
> 
> From post 1858:
> ...


 
  Did someone say a surprise i love surprises !


----------



## Acapella11

Hi Hypnos1, Apparently my Svetlana 6A2Ps do not have the ribbing , they are plain dark grey, which is almost unique between my tubes. It is like anthracite. I will take some shots later. But talking about it, I think I found a tube, which reflects this anthracite and smooth plate 6A2P (10/1967). It is a recent purchase, a Lorenz EK90 tube from Germany Army stocks (box dates to 1972)! Isn't that crazy. They look absolutely identical and sonic similarity is given. I need to hear them more in order to be able to also confirm sonic identity.
 Oh, after more (comparative) listing to the Siemens EH90 tubes, my appreciation for them increased and they are in good competition with my Siemens EK90. They are not of your SH-logo and flat plate type, which I have just ordered. A pic is here and they look like the ones Mikelap has.
  
 Hi Mordy, Woot, you actually kept it in mind. Well, no, you did not miss anything but indeed there will be little surprise when I come around writing it up. I would like to first sort out my current heptodes. The EF91/92 6-7 strap mod in EF95 setting has actually been in the table almost since the beginning. It is the last picture before the update notes. I agree, the formatting was not optimal and is updated now as well as a few minor other details.


----------



## MIKELAP

Quote: 





acapella11 said:


> Hi Hypnos1, Apparently my Svetlana 6A2Ps do not have the ribbing , they are plain dark grey, which is almost unique between my tubes. It is like anthracite. I will take some shots later. But talking about it, I think I found a tube, which reflects this anthracite and smooth plate 6A2P (10/1967). It is a recent purchase, a Lorenz EK90 tube from Germany Army stocks (box dates to 1972)! Isn't that crazy. They look absolutely identical and sonic similarity is given. I need to hear them more in order to be able to also confirm sonic identity.
> Oh, after more (comparative) listing to the Siemens EH90 tubes, my appreciation for them increased and they are in good competition with my Siemens EK90. They are not of your SH-logo and flat plate type, which I have just ordered. A pic is here and they look like the ones Mikelap has.
> 
> Hi Mordy, Woot, you actually kept it in mind. Well, no, you did not miss anything but indeed there will be little surprise when I come around writing it up. I would like to first sort out my current heptodes. The EF91/92 6-7 strap mod in EF95 setting has actually been in the table almost since the beginning. It is the last picture before the update notes. I agree, the formatting was not optimal and is updated now as well as a few minor other details. 
  Thanks for the update always appreciated .


----------



## siles1991

I just realized my stock tubes that came with the LD MKIII I think is the Sylvania 5654, it shows JHS 5654. Made in USA and also faded letters but I can make out "VAN_A" So i'm assuming it's Sylvania instead of the GE5654 though it has green letterings. And the only code I can make out is 308 which is inscribed from top to bottom.
   
  Anyone can help me identify this?


----------



## mordy

JHS is a code used by Sylvania. As for the 308 a semi educated guess would be that the first digit stands for the year and the second and third represent the week of manufacture. Thus it could mean the 8th week 1973/(1963).


----------



## siles1991

Which is quite interesting since I thought LD MKIII only came with GE5654 hmm...


----------



## Acapella11

Brief update for the Svetlana 6A2P and Lorenz EK90. OK, they are not perfectly identical. The saucer getters are differently constructed between them. Else, they are pretty much the same from the outside.


----------



## mab1376

Quote: 





acapella11 said:


> Brief update for the Svetlana 6A2P and Lorenz EK90. OK, they are not perfectly identical. The saucer getters are differently constructed between them. Else, they are pretty much the same from the outside.


 
   
  The Lorenz are very nice, very similar to the Telefunken EK90.


----------



## gibosi

European EBC90/EBC91 triodes
   
  While these tubes do not strictly conform to the "British - Holland - German sound continuum", I have still tried to organize them in terms of their "warmness" to make this review easier for me to write and for the reader to follow. Obviously, with this many tubes (6 total?),  it is beyond my limited capabilities to provide much more than a few cursory comments regarding differences in tonality. Even so, I hope it is enough to help others decide which they might be interested in procuring.   
   
  To begin, I have to say that all of these tridoes have seemingly unbounded crystal-clear highs, with a tight, low and punchy bass. Moreover, they are all excellent tubes, differing primarily in warmth and fowardness.  Sonically I believe these triodes are equal rivals to pentodes and yes, even heptodes, and I encourage everyone to try at least one. 
   
  First , the warmest and most mellow are the Tungsram EBC91. These are cozy and comfortable with excellent highs. I might call this a very safe tube.
   

   

  Second, we have a tie. The Mullard EBC91 and the Philips Miniwatt CV452/EBC90 (6AT6). These tubes have a similar warmth to the Tungsram, but are just a bit brighter. Even though the Mullards were manufactured in the Blackburn factory and the Philips in the Heerlen factory, these two tubes sound identical to me, and in fact, appear to have identical construction. At the least, the EBC91 should have more gain, but since the LD 1+ is configured to derive no gain from driver tubes, it is hard for me to discern small differences in output level. Either way, if you like the warm, classic Mullard sound, either of these is a keeper. Excellent tubes.
   

   

   Third, the Telefunken EBC91. These are less warm than the Mullard, but brightness and trebel detail is about the same. I did not find them as foward and bright as the Telefunken EK90 and EH900S. So if the Mullard sound is just a little too warm for you, these just might fit the bill. These too are excellent tubes.

   

   

  Fourth, the Lorenz EBC91. These are noticably less warm than the Mullards, but still, as AFB notes, while they are quite forward, the vocals have this sultriness about them, which is hard to describe. That and the crystal-clear highs and strong bass, make these quite special in my opinion. Again, excellent tubes, but they require some time to fully appreciate them.
   

   

  Fifth, the Amperex EBC91 (AKA RCA 6AV6). Yes indeed! Amperex put their BugleBoy name on these black plate RCAs! These are similarly forward like the Lorenz, but the vocals are smoother and more neutral. That and the crystal-clear highs and strong bass make these a standout for those who eschew the classic Mullard warmth. Since they lack the upper-bass / lower-midrange warmth of the Mullards and the sultriness of the Lorenz, these might seem to have less bass presence. However, the bass goes just as deep and has just as much punch. So on the "Euro-Tubiness Continuum", I judge these RCAs as the most "German" of the "European" tubes I have heard to date! lol
   

   
  Hope this is helpful to somebody... And now I am ready for a break!


----------



## Acapella11

Thanks for the nice work gibosi, will keep them in mind =). Which is the one with the most stage of these? I found my Mullard CV417 very focused but rather flat.


----------



## jaywillin

Quote: 





gibosi said:


> European EBC90/EBC91 triodes
> 
> While these tubes do not strictly conform to the "British - Holland - German sound continuum", I have still tried to organize them in terms of their "warmness" to make this review easier for me to write and for the reader to follow. Obviously, with this many tubes (6 total?),  it is beyond my limited capabilities to provide much more than a few cursory comments regarding differences in tonality. Even so, I hope it is enough to help others decide which they might be interested in procuring.
> 
> ...


 

 its very helpful, i've got a lot to learn, and i'm basically starting from scratch, and i do have some of the tubes you suggested coming !


----------



## gibosi

Quote: 





acapella11 said:


> Thanks for the nice work gibosi, will keep them in mind =). Which is the one with the most stage of these? I found my Mullard CV417 very focused but rather flat.


 
   
  It was everything I could do just to do what I did! And now you want more? lol
   
  I can say that your CV417 / EC91 / 6AQ4 is not even close to being in the same league as these EBC90 / 6AT6 and EBC91 / 6AV6. As best as I can remember, for one thing, the 6AQ4 is quite dry. And I have this vague understanding that some degree of wetness / reverberation is required in order to convey a sense of space. The EBC9X tubes do convey a nice sense of space, but I am not able to differentiate among them at this time....
   
  As AFB has all of these tubes (with the exception of the RCA I think), perhaps he will be willing to give us his impressions with respect to stage. And further, MIKELAP has recently amassed a nice assortment of American 6AV6, and perhaps he too will jump in.


----------



## gibosi

I have been looking for some tracks to help me evaluate bass, especially sub-bass, and I have been told that this is a good test. What do you think?


----------



## Audiofanboy

Quote: 





gibosi said:


> It was everything I could do just to do what I did! And now you want more? lol
> 
> I can say that your CV417 / EC91 / 6AQ4 is not even close to being in the same league as these EBC90 / 6AT6 and EBC91 / 6AV6. As best as I can remember, for one thing, the 6AQ4 is quite dry. And I have this vague understanding that some degree of wetness / reverberation is required in order to convey a sense of space. The EBC9X tubes do convey a nice sense of space, but I am not able to differentiate among them at this time....
> 
> As AFB has all of these tubes (with the exception of the RCA I think), perhaps he will be willing to give us his impressions with respect to stage. And further, MIKELAP has recently amassed a nice assortment of American 6AV6, and perhaps he too will jump in.


 
   
  Quote: 





gibosi said:


> I have been looking for some tracks to help me evaluate bass, especially sub-bass, and I have been told that this is a good test. What do you think?


 
   
  Yes, as I have a pair of most of those same triodes, I should be able to give a few extra comments from memory:
   
  - Tungsram EBC91 are a very nice compromise as far as triodes go. Not too forward or over-detailed, and nice and mellow. These sound closer to our classic pentodes that to other triodes imo.
   
  - Philips CV452, I actually haven't even had a chance to listen to these much but they seemed warm and detailed; I'd go with gibosi's comments on these.
   
  - Lorenz EBC91, I had described these at length somewhere back 30 pages ago, but the key idea was that they take 30 mins to get _into_ the music, but then have a very interesting and pleasant quality about them, sultry as I said.
   
  - Telefunken EBC91, now these are different from the Lorenz, but also had just a bit of that "learning curve" imo, where it took 10 mins to make sense of what you hear. They, indeed, sounded much less forward than all the other Telefunken tubes I've tested (which is a good thing).
   
  If you just want an easy -and hopefully cheap- triode ride, I'd suggest trying to get a pair of those Lorenz tubes first (the real ones, not the SEL Lorenz or other). The Tungsram and Tele are also very nice, but the former I have seen no other examples of on ebay (not the same un-German-looking ones at least) and the latter are way too expensive to be worth it compared to the other German triode offerings.
   
  About sub-bass -a difficult topic actually- yes, James Blake is the _de facto_ test standard lol; I know few other low-key albums that go that low in frequency and enable you to test bass that low. He also has an old two-track EP called "Air and Lack Thereof", and the first track with that same name is also a very good test track imo (half of the track is the guy just playing between bass and sub-bass as the only instrument).
   
  20h on my M.B.L.E Mazda EH90, and I have to say that while these share nothing with my Siemens tubes -or German sound at all- they are top tier tubes. Yes, they are warm. No, it's not what I like or seek. But, they sound great, detailed, ambient, real, physiological/human; and the bass is a kind of the cherry on the cake, deep rumbling bass that improved a fair amount with burn-in. My hopes are, like that hypnos' tubes, mine will get even better after 30h.
   
  Anyway, they're not Siemens, but I still recommend them!


----------



## hypnos1

Hi guys.
   
  Just a further snippet in the ongoing Siemens EH90 saga (headache?).
   
  When I received my 2nd pair, I thought I had hit the jackpot - 'made in germany' on the back and 3-digit number on the top of the tubes - cracked open my favourite bottle of wine (you can keep your champers!). Then...I looked more closely near the bottom. Lo and behold : B5I4!! Now my schooldays geography is a bit rusty, but I never knew Blackburn is in Germany!
   
  AFB and gibosi are spot-on about THE LIE - how do they get away with it (or are we all missing something?). Very annoying/disappointing. ALMOST put the cork back in the bottle, but decided to slurp by way of solace rather than joy! Mind you, a slight smile returned when they proved to be totally SILENT (the first a little less so). It widened a bit more when I could have sworn the bass sounded even deeper/richer - a possible consequence of the quieter tubes? Or expectation/hope!...Whatever, they were at least a match for the 1st pair, with no burn-in, so it bodes well...And then I reminded myself of how magical the first have become (for me, anyway - as I am sure for others) -and the smile grew, and another glass of wine made its way down the gullet. Lovely...
   
  BTW. Above the B****s are the letters GE1 - which I first thought stood for 'Germany'. Silly me. Any ideas folks?
   
  Anyway, here's some more pics...something of slight interest - if you look closely, the only difference I could discern was the width of the metal laterals seen through the rectangular holes (forgive my ignorance as to what they are). They are wider on the 'made in germany' ones. So obviously not TOTALLY identical.
  Another point - the first pair were identical, but the boxes different : one said 'heXode', the other 'hePtode'. The 2nd pair had 'heXode' on the boxes. It all looks like a conspiracy to me!!!
   
  Good luck everyone...(Top pic 2nd pair, middle/bottom 1st left, 2nd right)


----------



## Acapella11

Updated the table on page 77 with two new pentode families:
   
*6BJ6*: pin-out as normal 6AK5 but not everything connected on the base if understand this right. 0.15 mA heater current. Hence you should be able to operate even EF91/92 setting as well as 2/7 strap. I haven't tested those. "The 6BJ6 is a variable μ RF pentode designed for broadcast radio receiver applications. A key feature is the modest heater power making it attractive for mobile applications" (National Valve Museum).
     
*6BA6*: I got a Shuguang 6K4 in my hands, which is basically a 6BA6 derivative. 0.3 mA heater current. The pin-out is that of 6AU6. The cut off is remote though. Funny enough, it even works with EF95 but obviously the recommended setting is 2/7 strap. Just very coarsely, the tube sounds fine.
   
   
  Quote: 





gibosi said:


> It was everything I could do just to do what I did! And now you want more? lol


 
   
  Sorry, I didn't want to sound greedy but this spatial perception was what I particularly didn't like about the Mullard 6AQ4. It would be a straight rule out criteria for me. Thank you for your impressions and also AFB's, which described the triodes further.


----------



## gibosi

Quote: 





acapella11 said:


> *6BA6*: I got a Shuguang 6K4 in my hands, which is basically a 6BA6 derivative. 0.3 mA heater current. The pin-out is that of 6AU6. The cut off is remote though. Funny enough, it even works with EF95 but obviously the recommended setting is 2/7 strap. Just very coarsely, the tube sounds fine.


 
   
  And I have a little experience with this tube. As it is a remote cut-off pentode, I wasn't sure how well it would work with LD II, III and IV amps. Tubes provide no gain in the 1+, so a nonlinear grid seems to present no real problems, but I have wondered how these might sound in amps where these tubes are configured as amplifiers to provide gain.
   
  If you are interested, see posts 966 and 989 on pages 65 and 66.


----------



## MIKELAP

Quote: 





gibosi said:


> I have been looking for some tracks to help me evaluate bass, especially sub-bass, and I have been told that this is a good test. What do you think?


 
  Regarding sub bass i have a tune for this its by Yanni and its called Vertigo but you can only ear the full  effect  of that sub bass from cd only with headphones you can ear it on utube partly as well but your missing half the wow factor i would say first time i heard that with the Denons it was like omg went to my friends house and did not ear that sub bass on his speakers they didnt go low enough.


----------



## gibosi

Quote: 





hypnos1 said:


> BTW. Above the B****s are the letters GE1 - which I first thought stood for 'Germany'. Silly me. Any ideas folks?


 
  GE = the Philips code for EH90
   
  1 = change code. Over time, as Philips implemented various changes and modifications to their tubes, the change code was incremented. I would guess that most of the time, these changes were small and perhaps undetectable to the naked eye.
   
  A good example is the Philips E91H/6687 manufactured in Heerlen, Holland, as I am somewhat familiar with four different pairs:
   
  3L = E91H
   
  Date 1957 = 3L3 (D-getter and pinched glass envelope)
  Date 1960 = 3L6 (D-getter and straight glass and ????)
  Date 1962 = 3L7 (O-getter and straight glass and ????)
  Date 1968 = 3L8 (?????)


----------



## MIKELAP

Does anybody have an opinion as to which of these tubes should be best on paper because right now i am trying the ELECTRONOR...... 62AP the dime a dozen tubes strapped 1-7 and they sound as good to me and maybe better than the Siemens eh90 i had on just before  or maybe it was just John Williams Close Encounters of the third kind Conductor Zubin Mehta i think i maid a good deal unless they change for the worse. if you have an opinion i would like to ear it  because i contacted seller about it just to ear is side of the story.


----------



## MIKELAP

Been listening to the Elctronorgtecnika 6A2P they are barely 3hours into burnin they are not the most transparent sounding tube in my arsenal maybe they will clear up i tried the 1-7 strap ,ef95 only, ef95 with 2-7 with modded socket adaptor and so far i like the 1-7 strap seems to have a fuller sound imo                                  .


----------



## Audiofanboy

Quote: 





gibosi said:


> GE = the Philips code for EH90
> 
> 1 = change code. Over time, as Philips implemented various changes and modifications to their tubes, the change code was incremented. I would guess that most of the time, these changes were small and perhaps undetectable to the naked eye.
> 
> ...


 

 Indeed, it is. My Mazda pair has "GE2" above the factory codes, while all my Blackburn-made ones have "GE1" written. The number is quite irrelevant for our purposes right now, as it is only a Philips change code. For older tubes, the change code can help discern production year, but here, nah...
   
  Regarding tube design: while this isn't true for a number of tube types, a lot of Philips Group tubes had the same "design" regardless of which factory/brand/label/country they were made in. Minute differences aside, the designs were often identical, explaining why, for example, Mullard 6AV6 and Philips 6AT6 -themselves identical to 6AV6 for all intents and purposes- sound the same.
   
  I'm pretty sure, in this case, that my M.B.L.E. Mazda EH90 sound very similar to Blackburn EH90 -like Hypnos'- and hell, they look the same, basically.
   
  The fact that Hypnos mentions the way his EH90 render bass -and seeing how my EH90 _rumble sub-bass_ which most of my tubes _don't_- only makes me think the Philips Group EH90 will turn out to be similar.


----------



## gibosi

At some point in time, American tube companies began etching "U.S.A." above the tube type. For example:
   
  U.S.A.
  6AV6
   
  Does anyone know the year this began to happen?


----------



## wuwhere

Not sure when that started but I have some mid-50's 12AX7 made by CBS and it has a 'Made In USA" printed on it. I also have a pair of JW2C51 tubes made by Western Electric that has a 'Made In USA" printed on it. I also have some vintage GE 6550s with 'Made In USA" printed on its metal base.


----------



## mordy

I have JAN Raytheon 6AK5W tubes from February 1945 that have the print MADE IN USA on them. Silk screening - not etched.


----------



## siles1991

Any benefits to pre amping my ld mkiii with another ld tube amp?


----------



## siles1991

-double post-


----------



## guildenstern

Greetings to more experienced and knowledgeable Little Dot tube-rollers from a new owner of the LD Mk III,
   
  Do you have any experience with the tubes offered by eBay seller "tubemazestore" in a package he modestly calls "THE ULTIMATE Little Dot NOS tube set"?


----------



## mab1376

we have been veering far from the 6AK5 tube family.
   
  also for some awesome power tubes get a pair of 6N6P-IR, very low noise and very clean.
   
  also check page 77 for a list of compatible tubes and modification setting for them to make them work, not all alternate tubes require modifications.


----------



## gibosi

Quote: 





guildenstern said:


> Greetings to more experienced and knowledgeable Little Dot tube-rollers from a new owner of the LD Mk III,
> 
> Do you have any experience with the tubes offered by eBay seller "tubemazestore" in a package he modestly calls "THE ULTIMATE Little Dot NOS tube set"?


 
   
  IMO, neither of these are "Ultimate" tubes. That said, I think you have to figure out if you might be a "tube roller," or if you just want to buy some nice tubes and listen to your music. If the latter, then this set might be a pretty good deal. But if you think that you might enjoy rolling a few tubes in a quest to find the best sound, as Mab suggests, you can certainly do better than these.


----------



## gibosi

Quote: 





wuwhere said:


> Not sure when that started but I have some mid-50's 12AX7 made by CBS and it has a 'Made In USA" printed on it. I also have a pair of JW2C51 tubes made by Western Electric that has a 'Made In USA" printed on it. I also have some vintage GE 6550s with 'Made In USA" printed on its metal base.


 
  所在地は最高機密ですか？面白い！：）
   
  None of my American tubes from the 1950s have "USA" etched into the glass, but by the mid-1960s, or so, all of them do. It seems to me that this change was likely due to US federal law and/or regulation, and if we knew the year of implementation, this would give us one more tool for dating purposes. I have Googled "country of origin labeling" and other related search criteria, but haven't found anything helpful.........


----------



## mordy

In case u want to know what the Chinese means:
   
  Location top secret で す は ka? White face Kei!


----------



## guildenstern

Quote: 





gibosi said:


> IMO, neither of these are "Ultimate" tubes. That said, I think you have to figure out if you might be a "tube roller," or if you just want to buy some nice tubes and listen to your music. If the latter, then this set might be a pretty good deal. But if you think that you might enjoy rolling a few tubes in a quest to find the best sound, as Mab suggests, you can certainly do better than these.


 

 Thanks to Mab and gibosi. Wise words, gibosi -- I'm not a dedicated tube roller, just looking for a set that will sound good with my Senn 650 'phones. Honestly, I'm pretty impressed by the stock tubes that came with the LD MkIII that I just bought from another head-fier. I don't want to make any mods to the amp at this time. Maybe for fun I'll just try a pair of the Voshkod 6ZH1P-EV or RCA 5654 (black plate) as recommended by Dept_of_Alchemy in his amazing epic post that initiated this thread. Thanks again.


----------



## jaywillin

i got these rca 5915's yesterday, and the first time i put them in the amp and listened, there was a substantial hum
  when i had the music paused, also, the tubes were very microphonic , i could hear noise if i touched the amp, tube, the headphone cable,
  i took the tubes back out, took some pics , put the tubes back in the amp, and they seem fine now, dead silent .
  is this normal ?


----------



## mordy

Been listening to the tune posted here for sub bass. To me it just sounds like warble tones added to the recording. If you want to test your system to see how low it goes, Stereophile Magazine has issued several test CDs and there you can find the lowest frequency bands recorded in ascending order.
  Don't know if I can hear tones under 20 Hz, but unless you listen to organ music I don't think that you can find that much music in this very lowest frequency range.


----------



## mordy

Usually, in a case like this, there was some problem with a cable connection that was corrected somehow.
   
  Are u using the 5915s with the 1/7 strap?


----------



## gibosi

Quote: 





mordy said:


> In case u want to know what the Chinese means:
> 
> Location top secret で す は ka? White face Kei!


 
   
  Actually, it is Japanese....
   
  For location, *wuwhere* lists 最大のセキュリティ = Highest Security.
   
  So I replied 所在地は最高機密ですか？面白い！= Top secret location? Interesting!"


----------



## jaywillin

Quote: 





mordy said:


> Usually, in a case like this, there was some problem with a cable connection that was corrected somehow.
> 
> Are u using the 5915s with the 1/7 strap?


 

 no strapping , just put the tubes into the amp


----------



## mab1376

Quote: 





guildenstern said:


> Thanks to Mab and gibosi. Wise words, gibosi -- I'm not a dedicated tube roller, just looking for a set that will sound good with my Senn 650 'phones. Honestly, I'm pretty impressed by the stock tubes that came with the LD MkIII that I just bought from another head-fier. I don't want to make any mods to the amp at this time. Maybe for fun I'll just try a pair of the Voshkod 6ZH1P-EV or RCA 5654 (black plate) as recommended by Dept_of_Alchemy in his amazing epic post that initiated this thread. Thanks again.


 
   
  I would recommend a pair of 6BE6 tubes for the HD650's and a pair of 6N6P-IR power tubes, thats exactly what i'm using with my HD650's right now and I love it!
   
  Also since the 6BE6 tubes are pretty unknown they are much much cheaper than the 6AK5 tubes.


----------



## mordy

I used Google translate since I don't know anything about Japanese or Chinese. Wuwhere's location was translated as Japanese, but what you wrote was translated as Chinese - go figure....


----------



## inphu510n

mab1376 said:


> I would recommend a pair of 6BE6 tubes for the HD650's and a pair of 6N6P-IR power tubes, thats exactly what i'm using with my HD650's right now and I love it!
> 
> Also since the 6BE6 tubes are pretty unknown they are much much cheaper than the 6AK5 tubes.




Wise words.


----------



## gibosi

Quote: 





mab1376 said:


> I would recommend a pair of 6BE6 tubes for the HD650's and a pair of 6N6P-IR power tubes, thats exactly what i'm using with my HD650's right now and I love it!
> 
> Also since the 6BE6 tubes are pretty unknown they are much much cheaper than the 6AK5 tubes.


 
   
  Well, not just any 6BE6. I found the GE version to be not so good.... Probably the best bang for the buck is this IBM 1680 manufactured by RCA in 1950:
   
  http://www.ebay.com/itm/300575458266?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649
   
  $4.39 per tube plus $1.69 shipping to you in Virginia. And it is the experience of this forum that he will take less. A pair for about $10.00 to you shipped! Keep your amp in the EF95 setting and plug them in. IMO, these IBMs and a pair of 6N6P-IR would be a very cost-effective and yet substantial upgrade to what you have now.
   
  Enjoy!


----------



## Kuzon

Hello everyone.
  Help me choose a lamp with a dark sound for my DT990pro
  I'm currently using GE JAN 5654W.
  I would like that darker sound with a normal bass.


----------



## mordy

Hi All,
   
  What follows here is a review of the the mighty Tesla 6H31  heptode tubes (6BE6) from 12/58. Unlike the Siemens EH90 whose pedigree is uncertain, these are the real thing, made in Czechoslovakia. What first strikes you looking at the tubes is that the getter flash is dark brown and not silver. The next thing is the very substantial getter supports that look like they were designed to support a bridge. Upon further examination, these tubes have a most unusual getter, the like of which I have not seen elsewhere. Until we find a better name to describe them, I am going to call them "Double Bread Pan Getter." Look at the second picture:

  The getter is a circular disk with an elongated hole in the middle, surrounded by two bread pan like depressions. All in all, this tube reeks of quality.

  After a grueling  48 hour break in (as recommended by the Hi Fi manufacturer Audio Research) and after trying EF95 1/7, EF95 NS (no strap), EF95 2/7 strap and finally EF92 setting (using the EF95 6/7 strap), the following conclusions were reached:
   
  The best setting for me is EF95 1/7 strap, followed by EF95 2/7 strap, and then EF95 NS and EF92. I won't burden you with the impressions of the other three settings, and especially the last two which were severely lacking.
   
  On the EF95 1/7 setting the first impression is detail. Gobs and gobs of detail, micro, macro, looking into the recordings and hearing things you did not know were there before. The detail of the bass and treble is exquisite; it is like you walked into a dark basement and attic and turned on the light - everything is there. The tubes are very revealing, but not ruthlessly revealing to the point that deficiencies in recordings are highlighted. However, the quality of different recordings becomes immediately apparent. The tubes are neutral but analytical with a super detailed presentation - they won't let you alone but force you to listen carefully. They are open, airy, crystal clear, with a wide 3D sound stage. The bass is strong with good timbre and grip on the low frequencies.
   
  The only con is a certain coolness in the mid range. The only way I can describe it is when you try to fix a photo on the computer and try to adjust the color and everything suddenly gets a slightly blueish hue. The tonality is not so warm, but perhaps it is equipment dependent.
   
  All in all, a worthy contender to the Siemens EH90. Overall, I find the Siemens a little more pleasant and warm. On a subconscious level, the Siemens tubes induce me to more toe tapping than the Teslas, whatever that means - I'll leave it for the psychologists.
   
  At the present time it seems very difficult to find the Siemens tubes. The Teslas can be found, and at moderate prices, and it may be worth wile to try them.
   
  Happy tube rolling!


----------



## mab1376

Quote: 





gibosi said:


> Well, not just any 6BE6. I found the GE version to be not so good.... Probably the best bang for the buck is this IBM 1680 manufactured by RCA in 1950:
> 
> http://www.ebay.com/itm/300575458266?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649
> 
> ...


 
   
  I personally love my Haltron branded Siemens tubes (which are very hard to find), Telefunken are a close second to me and Lorez and Tung-sol are both also very good.
   
  Also the EU designation for these tubes are EK90, so search either of the two.


----------



## hypnos1

Quote: 





gibosi said:


> GE = the Philips code for EH90
> 
> 1 = change code. Over time, as Philips implemented various changes and modifications to their tubes, the change code was incremented. I would guess that most of the time, these changes were small and perhaps undetectable to the naked eye.
> 
> ...


 
   Hi gibosi,
   
  Another little detail to confuse  matters even more : my first pair of 'Siemens' EH90s (without 'made in germany' on) had code B6G3, which is 1966, ya? The second (WITH) have B5I4, which is therefore 1965...Now the first have plain GE above, the second GE1 - one would have expected the change code to be the other way round , non? My conspiracy theory moves forward another step!!! (There's probably a very simple explanation...???).
   
  Audiofanboy - glad I wasn't having a 'bad ear day' re the bass on these babies...when I returned once again to Cat Stevens's remastered 'Hard headed Woman', it nearly blew my head off!! So yet another added bonus - even if they aren't actually Siemens/Germany made...Will be interested to see what you make of the Blackburns after further burn-in.
   
  Cheers!


----------



## gibosi

Quote: 





hypnos1 said:


> Another little detail to confuse  matters even more : my first pair of 'Siemens' EH90s (without 'made in germany' on) had code B6G3, which is 1966, ya? The second (WITH) have B5I4, which is therefore 1965...Now the first have plain GE above, the second GE1 - one would have expected the change code to be the other way round , non? My conspiracy theory moves forward another step!!! (There's probably a very simple explanation...???).


 
   
  Conspiracy theory? lol... However, I don't have an explanation and all I can do is conjecture that it might simply be a poor etching. On my single Siemens (1959 [B9F] and pair of Valvos [1967 (B7A3)],  I can't even find GE plus a number etched in the glass. If these codes are there, they are just too faint for me to make out....


----------



## gibosi

I am still luxuriating in triode land, most recently under the spell of the Amperex/BugleBoy EBC91 (or perhaps, I should say RCA 6AV6! lol).
   
  This morning, I received a pair of CBS-Hytron 6AV6. Yes, this CBS is the Columbia Broadcasting System. In the early 1950s, CBS acquired Hytron Laboratories as they attempted to push deeper into vacuum tube technology, TV and radio manufacturing, and color broadcasting. However, this venture was short-lived as it appears that CBS-Hytron ceased production in 1961. These tubes are dated 1958.


----------



## gibosi

Quote: 





mordy said:


> Hi All,
> 
> What follows here is a review of the the mighty Tesla 6H31 heptode tubes (6BE6) from 12/58.....
> 
> ...


 
   
  I'm not surprised that you are finding the mid range a bit cool. Grid 3 on the 6BE6 is remote cutoff, that is, it was deliberately and precisely designed to have a nonlinear response. Thus when you strap a linear Grid 1 and a nonlinear Grid 3 together, the resulting combined grid is going to be somewhat nonlinear. And it makes perfect sense that a nonlinear grid is going to affect the sound in some way.
   
  When I strapped the Siemens EK90 (6BE6), 1/7, I had a similar experience. The analytical detailed presentation and 3D sound stage were beyond compare, but the mid range was just not right. Eventually, I arrived at the conclusion that for me, unstrapped was best for that particular tube.
   
  Interestingly, it seems that this phenomena may not be due entirely to the fact that the 6BE6 Grid 3 is nonlinear. Even strapping the 6BY6, with two linear signal grids 1/7, I notice that the mid range becomes a bit thinner on both the Sylvania 5915 and the Amperex E91H/6687. AFB also noticed and discussed this with regard to his Telefunken/Sylvania 5915. However, at least on the Sylvania 5915, strapped 1/7, in my mind the mid range is still quite acceptable, and the analytical detailed presentation and 3D sound stage more than makes up for a slightly thinner mid range.
   
  And now that more people are listening to the 6CS6/EH90, it will be interesting to learn more about how they behave strapped 1/7....


----------



## siles1991

Ah after reading all your posts I am so curious! I want to tube roll too but sadly the shipping costs from other countries are just way too high. If only my country sold nos tubes...instead only shops which sell brands like EH,JJ,Gold lion. All the expensive ones and none compatible with the little dot. I shall continue to stalk this thread so I can find more tubes to try. Thank you guys for the time you take to try these tubes.


----------



## bruce108

Post ex-2045 [I see it's disappeared & there's a new one] above is clearly spam & has been duly reported. The French is a random extract from an online contract & the links speak for themselves.
   
  Tiresome.


----------



## mordy

Hi Gibosi,
   
  I feel so much better now that somebody is commenting on my Tesla review that involved many hours of thought, effort and reflection - thanks.
   
  Since the differences between different heptodes are so subtle, it is much more difficult to differentiate and describe the characteristics of each tube. The evaluating process is known to lead to heptode overload and heptoditis, usually cured by putting your brain in neutral and taking a break from critical listening.
   
  I have used the Teslas another 10 hours. Don't know if my brain or the tubes adjust (or both), but the mid range discoloration seemed to disappear into the background, and I was thoroughly enjoying the tubes so much so that I didn't want to switch to the next project of evaluating the IBM 1680 tubes. As you state: _the mid range is still quite acceptable, and the analytical detailed presentation and 3D sound stage more than makes up for a slightly thinner mid range._
  
  Now, re the EH90, when I tried my Siemens EH90 unstrapped the Dreaded Hum suddenly appeared in the right channel. It sounded like the low frequency hum of a window air conditioner and was not volume dependent. Once before I had hum in the right channel which went away after I changed the tubes. The Little Dot blog has several entries about R channel hum and a check list how to try to eliminate it. Seems that in some instances the hum comes from a bad cable connection. Don't know yet if the hum was permanent for the NS setting with the Siemens tubes or temporary. Also don't understand why the hum would only affect one channel, and always the R channel. The design of the LD is two completely separate channels, but in many instances only the right channel hums, which leads me to think that there is some kind of synergistic effect.
   
  I have a pair of Sylvania 6CS6(EH90) tubes waiting to try but this has to wait until the 1680's have been grilled to perfection....


----------



## MIKELAP

Speaking of grilling 20 hours later the hungarian russian 6A2P tubes dont sound bad but are not as open and transparent as the SYLVANIA 6AV6 that i am starting to burnin now, the Sylvania sound like a typical 6av6 tube so far. And by the way Audiofanboy dropping by in Montreal tomorrow with little glass goody's i got from him .It's going to be fun meeting him and his dad . Like we say over here. BIENVENUE AU QUEBEC !


----------



## MIKELAP

News regarding the socket adaptors reported a while back that sockets didnt work well actually they did but they were built backwards the amp jumpers should of been on the EF92 settting instead of theEF95 settings, noticed this today on the sellers website when i read the bottom of the page  i went aaaaaaaaaaaaaaaaahhh !!!!!! so  UNDER THE AMP EF92 JUMPER SETTINGS when the SOCKETS ARE ON  you can use the EF 95 TUBES  ain't that grand.  EDIT: NOTICE TUBE IS EF92 NOTHING TO HELP CLEAR THINGS UP !


----------



## Audiofanboy

Yup, private NOS tube exchange in Montreal, PQ, tomorrow; you just can't stop globalization lol. We have a French in his late 20s selling American & German olde world tubes to a Canadian twice his age -and all that while on vacation, I'd call that optimizimation!

About strapping heptodes, and especially the newest 6CS6/EH90, I found that my M.B.L.E. Mazda EH90 (which should sound and react very close to Blackburn's) sounded very nice 1-7 srapped actually. I had to quit rolling them since I was leaving the country for a few weeks, but from what I had time to test, the tubes had more gain than unstrapped (moreso than the difference we saw with other heptode types, which makes sense as g3 has a higher gain on this type; I suspect the amp also ran hotter but then again it was 30/90 °C/F...), sounded just a tad more detailed (not a night and day difference like 6BY6 tubes), and the bass was even better (harder hitting) and deeper (sub bass like I've rarely heard on this amp). I haven't reached a conclusion as to what setting I prefer though.


----------



## MIKELAP

Quote: 





audiofanboy said:


> Yup, private NOS tube exchange in Montreal, PQ, tomorrow; you just can't stop globalization lol. We have a French in his late 20s selling American & German olde world tubes to a Canadian twice his age -and all that while on vacation, I'd call that optimizimation!
> 
> About strapping heptodes, and especially the newest 6CS6/EH90, I found that my M.B.L.E. Mazda EH90 (which should sound and react very close to Blackburn's) sounded very nice 1-7 srapped actually. I had to quit rolling them since I was leaving the country for a few weeks, but from what I had time to test, the tubes had more gain than unstrapped (moreso than the difference we saw with other heptode types, which makes sense as g3 has a higher gain on this type; I suspect the amp also ran hotter but then again it was 30/90 °C/F...), sounded just a tad more detailed (not a night and day difference like 6BY6 tubes), and the bass was even better (harder hitting) and deeper (sub bass like I've rarely heard on this amp). I haven't reached a conclusion as to what setting I prefer though.


 
  Private you say sounds serious ill bring my body guard (my wife) later .


----------



## siles1991

http://www.ebay.com.my/itm/Lot-of-2-Vintage-TELEFUNKEN-EH900S-E91H-Audio-Radio-Amp-Vacuum-Tubes-/400405173654?pt=Vintage_Electronics_R2&hash=item5d3a021596&_uhb=1#ht_1630wt_1139
   
  Just found this on ebay  TFK E91H only 8$ for a pair before shipping. According to the codes i'm thinking Heerlen 1969 January 4th Week


----------



## MIKELAP

Quote: 





siles1991 said:


> http://www.ebay.com.my/itm/Lot-of-2-Vintage-TELEFUNKEN-EH900S-E91H-Audio-Radio-Amp-Vacuum-Tubes-/400405173654?pt=Vintage_Electronics_R2&hash=item5d3a021596&_uhb=1#ht_1630wt_1139
> 
> Just found this on ebay  TFK E91H only 8$ for a pair before shipping. According to the codes i'm thinking Heerlen 1969 January 4th Week


 
  Misread shipping rate saw $42.80 but that was to Malaysia i think is shipping rate decent.


----------



## siles1991

Quote: 





mikelap said:


> Misread shipping rate saw $42.80 but that was to Malaysia i think is shipping rate decent.


 
  Even my 5 pcs of 6AH6WA didnt cost me more than 15$...42.80$ for 2 pcs is a bit much...for shipping that is


----------



## TrollDragon

mikelap said:


> Misread shipping rate saw $42.80 but that was to Malaysia i think is shipping rate decent.


What the hey....

 Shipping to: Worldwide
 Excludes: Canada

This seller does not ship to Canada

Now there's a prime DB for ya...


----------



## siles1991

Quote: 





trolldragon said:


> What the hey....
> 
> Shipping to: Worldwide
> Excludes: Canada
> ...


 
  Could always send to someone in Canada and ask them to send it to you hahaha. But mine is just...way too costly...especially since in Malaysia i'm paying 3x the price because of currency exchange. Shipping is about 4-6 days worth of part time work 42.80$...


----------



## mordy

Hi Siles 1991,
   
  According to the USPS (United States Post Office) calculator a 5 oz package First Class International mail package to Malaysia is $12.15. Don't know if it is necessary to send registered mail which ups the price.
   

 First-Class International Options  
 
   First-Class Package International Service™**


 [size=9pt] Maximum Value for Contents: $400.00[/size]
 [size=9pt] Other than rolls: Max. length 24", max length, height and depth (thickness) combined 36"
 Rolls: Max. length 36". Max length and twice the diameter combined 42"[/size]

 Varies by destination   $12.15

    


   
   
  The seller wants almost $11 for US shipping when the actual cost is less than $3.


----------



## siles1991

Quote: 





mordy said:


> Hi Siles 1991,
> 
> According to the USPS (United States Post Office) calculator a 5 oz package First Class International mail package to Malaysia is $12.15. Don't know if it is necessary to send registered mail which ups the price.
> 
> ...


 
  Exactly what I thought!


----------



## jaywillin

another "noob" question
  where would i get some jumper caps ??
  
 To use EF91, EF92, CV131, CV138, etc:
 1.
 K1 and K2 set to the side o
 f the “6JI” text
 2.
 Make sure the jumpers caps are
 in place
 over both J1 and J2 (short circuit)
   
  i don't seem to have the jumper caps to put over J1 and J2

  i set the jumpers to the setting for 408 tubes, and i'm listening to the GE408's that came with the amp, i previously had listened to the 408's when the amp was set up for the 6ak5
  this way is much better, imagine that ! lol


----------



## gibosi

Quote: 





jaywillin said:


> another "noob" question
> where would i get some jumper caps ??
> 
> To use EF91, EF92, CV131, CV138, etc:
> ...


 
   
  Normally they come with the amp. Otherwise, I believe these are just 2.54mm standard jumper caps for circuit boards. Radio Shack or any electronics part store should have these cheap, like a few bucks for 50 of them.
   
  Something like the following should work, but again, check in the box your amp came in to see if you already have some..
   
  http://www.ebay.com/itm/50-Pcs-Mini-Micro-Jumper-2-54mm-Standard-Circuit-Board-Shunts-Short-Jumper-Cap-/321092717317?pt=LH_DefaultDomain_0&hash=item4ac29e0b05


----------



## jaywillin

the fellow i got the LDI+ included this single tube, and i'm not sure what it is,
  anyone know for sure ?  is the 6028 the same as 408a ??
   
  thanks


----------



## mordy

Did u insert the picture?
   
  On the toolbar for Reply there is a colorful square that allows u to insert an image.


----------



## jaywillin

Quote: 





gibosi said:


> Normally they come with the amp. Otherwise, I believe these are just 2.54mm standard jumper caps for circuit boards. Radio Shack or any electronics part store should have these cheap, like a few bucks for 50 of them.
> 
> Something like the following should work, but again, check in the box your amp came in to see if you already have some..
> 
> http://www.ebay.com/itm/50-Pcs-Mini-Micro-Jumper-2-54mm-Standard-Circuit-Board-Shunts-Short-Jumper-Cap-/321092717317?pt=LH_DefaultDomain_0&hash=item4ac29e0b05


 

 yeah, i figured if i'd bout it new, they'd be included, but i got this used, at least now i know what to ask for ! lol
  also, in changing my jumpers to the 408a setting, the erricson 408a's that i thought were bad, aren't, the sound good now !


----------



## jaywillin

Quote: 





mordy said:


> Did u insert the picture?
> 
> On the toolbar for Reply there is a colorful square that allows u to insert an image.


 

 yeah, i forgot, it should be in there now lol


----------



## mordy

Here is your answer:  6028 = 408A. CTL means that it was made by Tung Sol which is a top manufacturer.
   
   
  http://www.radiomuseum.org/tubes/tube_6028.html


----------



## jaywillin

Quote: 





mordy said:


> Here is your answer:  6028 = 408A. CTL means that it was made by Tung Sol which is a top manufacturer.
> 
> 
> http://www.radiomuseum.org/tubes/tube_6028.html


 
   oh thanks for that link, it should be a big help as i learn this stuff


----------



## siles1991

What should I do if the mkiv SE runs out...it seems it might be down to their last unit according to davidzhezhe's ebay account. Was planning to get it in the future but unsure now what I would like to get if it did sell out.


----------



## mab1376

Quote: 





siles1991 said:


> What should I do if the mkiv SE runs out...it seems it might be down to their last unit according to davidzhezhe's ebay account. Was planning to get it in the future but unsure now what I would like to get if it did sell out.


 
   
  Don't go by ebay, if you email him with your concern he'll get back to you in less than a day.


----------



## kvtaco17

Just rolled in a set of Siemens 6AK5W (Little Dot I+) and I like them way better then the stock tubes... super crunchy, slightly warm, good punch. decent detail (compared to o2 and Magni) good extension... really like the crunch it has with guitars. Voshkod's are next!


----------



## siles1991

I tried 2/7 strap for my e91H but it was incredibly quiet O_O like really really quiet compared to my 1/7 strap which had decent volume, i think the wire jumper im using doesnt have enough strands
   
  edit: nope 2/7 is incredibly soft no matter what type of wire i use as a jumper and doesnt change when i tried jiggling the tubes, ah well 1/7 isnt half bad but would have been nice to try 2/7 hopefully the 2/7 will work when I use the 6AH6WA
   
  edit2: I put it in the wrong hole =.= sorry


----------



## gibosi

Now that I have had a chance to listen to the CBS-Hytron 6AV6, I am quite surprised to report that to me it sounds indistinguishable from the RCA 6AV6. The reason I am so surprised is that it doesn't look like any RCA I have ever seen. Specifically, I have never seen an RCA with that little disc attached to the top of the diodes. The only other tube I have seen with this kind of construction is a Sylvania 6AQ6. However, the CBS doesn't look that much like the Sylvania and it doesn't sound the same.
   
  That the CBS sounds like an RCA isn't bad as it is one of my favorite 6AV6. However, as I already have two pairs of these (one with black plates and one grey), as well as a pair of RCA 6AT6, I really don't need a fourth pair! lol


----------



## siles1991

After spending some time listening to the E91H with 2/7 I agree that its aggressive and forward a bit too much for me xD i'd recommend starting with 2/7 first though and if you feel fatigue you can go down to 1/7 strap.


----------



## gibosi

Quote: 





siles1991 said:


> After spending some time listening to the E91H with 2/7 I agree that its aggressive and forward a bit too much for me xD i'd recommend starting with 2/7 first though and if you feel fatigue you can go down to 1/7 strap.


 
  Do you prefer the E91H strapped 1/7 over unstrapped?


----------



## siles1991

Quote: 





gibosi said:


> Do you prefer the E91H strapped 1/7 over unstrapped?


 
  yes I do, it feels like there is more depth in my music.


----------



## siles1991

guys i might be planning to upgrade from a mkiii to a mkiv and david said i could get the SE version without the tubes which im prolly gonna take up, so if I want to get the 6N6P-IR does it have to be matched?


----------



## mordy

How much do you save without tubes?
   
  There are not that many sources for the 6N6P-IR tubes; probably the closest match you could get is the same month and year.


----------



## siles1991

Quote: 





mordy said:


> How much do you save without tubes?
> 
> There are not that many sources for the 6N6P-IR tubes; probably the closest match you could get is the same month and year.


 
  Well with the tubes its 399USD without he is giving it to me for 305USD so im saving about 50USD if i get the 6n6p-ir and use my tubes from mkiii


----------



## mordy

Hi All,
   
  Here is a review of the IBM 1680 (6BE6) tube made by Sylvania: (please read until end or skip to summary)
   
  EF95 1/7 Strap setting (used for burn in): The first impression was the signature heptode sound of wide expansive sound stage, clarity and abundant detail. Then some shortcomings became apparent: soft flabby bass, cool mid range, lack of dynamics, and sibilant treble.
   
_These deficiencies disappeared slowly, and after significant burn in they almost all disappeared to a certain extent._ After being burnt in for 50-60 hours the tubes had improved markedly. The bass is acceptable but lacks slam and attack. The mid range became warmer. The highs are still sibilant and sharp. Good bye (and good riddance) EF95 1/7 setting.
   
  EF95 NS (no strap): This setting yields better sound than the one previously described. Firmer, more distinct bass, mid range regular warm, highs still sharp but no sibilance, good detail. Yep, much better, but no wow factor. A certain lack of micro dynamics, rhythm and pacing. A good simulation of my solid state receiver with better bass. Bye Bye EF95 NS.
   
  EF95 2/7 strap: Wow! Multi layered 3D heptode magic! Bold, powerful bass, full of details and micro dynamics, great highs. Involuntarily toe tapping - a 4 on a scale of 5.
  Cons: Bass does not go down to the deepest levels, and there is a minor mid range coolness and hollowness.
  Very good presentation overall with tons of detail and musicality. EF95 2/7 - you are welcome any time.
   
  EF92 setting (using EF95 6/7 strap setting): Treble excellent with great detail and power but some sibilance; mid range good, bass is a bit boomy. Overall quite good, grows on you. Perhaps this setting would match certain types of equipment.  EF92 - nice to see you, bye.
   
   
  SUMMARY OF THE IBM 1680 TUBE:
  As mentioned before, the differences between heptodes are much more subtle than between 6AK5 tubes, and thus harder to describe.
  Using the EF95 2/7 strap setting this tube is very good performer, albeit not on the level of the very best heptodes.
   
  The EF92 setting may be a good choice if you like a very detailed treble presentation.
   
  EF95 NS is OK. 
   
  EF95 1/7 is not recommended.
   
  Price wise, the 1680 is a winner with a cost of less than $8 for a pair shipped.
   
  As they say in a prominent consumer magazine: Recommended, Best Buy.
   
  Edit 7/27/13: Listening to the EF92 simulated setting now. Don't know if the tubes stabilized or my perception changed, but these tubes sound excellent now on this setting. Bass is firm but not in your face, almost no sibilance. Detail, detail. Simply beautiful.


----------



## mordy

Here is a source for the IR tubes. I have bought from him in the past - good seller, but shipping takes a month or more to the US.
   
   
  http://www.ebay.com/itm/151083068087?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1438.l2649


----------



## mab1376

This is also the sell i bought from: http://www.ebay.com/itm/6N6P-IR-ECC99-E182CC-high-durable-double-triode-tubes-Lot-of-2-pc-NOS-/300693108383?pt=LH_DefaultDomain_0&hash=item4602b4b69f


----------



## gibosi

Quote: 





siles1991 said:


> Well with the tubes its 399USD without he is giving it to me for 305USD so im saving about 50USD if i get the 6n6p-ir and use my tubes from mkiii


 
  399 - 305 = 94.....  Or am I missing something?
   
  Edit: Oh, now that I think about it, perhaps you are assuming that a pair of 6N6P-IR will cost about 44.....


----------



## siles1991

Quote: 





gibosi said:


> 399 - 305 = 94.....  Or am I missing something?
> 
> Edit: Oh, now that I think about it, perhaps you are assuming that a pair of 6N6P-IR will cost about 44.....


 
  yep make a bit of leeway ^_^
   
  because shipping to my country is expensive


----------



## jaywillin

well, having learned where the jumpers go for each tube type, and buying the jumpers i was missing, all the tubes i thought were bad, the erricson 408a's, and the zarerix 6am6's aren't bad, they sound fine, i may be slow, but i'm catching on ! lol


----------



## gibosi

Quote: 





jaywillin said:


> well, having learned where the jumpers go for each tube type, and buying the jumpers i was missing, all the tubes i thought were bad, the erricson 408a's, and the zarerix 6am6's aren't bad, they sound fine, i may be slow, but i'm catching on ! lol


 
   
  And now that you are up to speed on the standard tubes, EF91, EF92, EF95 and 408A, it is time to move on to some of the non-standard tubes!


----------



## ancientfire

And where did you purchase the jumpers?


----------



## jaywillin

Quote: 





ancientfire said:


> And where did you purchase the jumpers?


 

 radio shack , under 2 bucks for 10, "DIP SHORTING JUMPERS"  , i believe gibosi provided a link a page or two back, for them off of ebay, 50 for about 3-4 bucks shipped
  i'd like to find a match for this  tung sol 6028 :

   
  i'm letting my fingers walk through the internet,  is this rare or something ??


----------



## jaywillin

Quote: 





gibosi said:


> And now that you are up to speed on the standard tubes, EF91, EF92, EF95 and 408A, it is time to move on to some of the non-standard tubes!


 

  well, i'm sure i'll get to that , i would like to find a mate , or be able to do something with the tung sol i have
  there are so many types, brands, versions of tubes, the possibilities are endless , and its cheaper for the most part than buying different headphones, dacs, amps, etc


----------



## gibosi

Quote: 





jaywillin said:


> i'd like to find a match for this  tung sol 6028 :
> 
> i'm letting my fingers walk through the internet,  is this rare or something ??


 
   
  I have never seen a Tung Sol 408A/6028...  I have the usual suspects: Northern Electric, Western Electric, and Sylvania Gold Brand/gold pins. However, I haven't listened to any of these in a long time.....


----------



## jaywillin

Quote: 





gibosi said:


> I have never seen a Tung Sol 408A/6028...  I have the usual suspects: Northern Electric, Western Electric, and Sylvania Gold Brand/gold pins. However, I haven't listened to any of these in a long time.....


 

 it did kinda surprise me,not finding any others and now i'm just curious about it, here's a couple of better pics

   

   
  well, one pic is better lol


----------



## gibosi

Quote: 





jaywillin said:


> it did kinda surprise me,not finding any others and now i'm just curious about it........


 
   
  It seems they are not at all common. But in my experience, if I can't find something, I keep checking every day or so, and eventually they turn up....
   
  In the meantime, triodes and heptodes are cheap and easy to find.


----------



## jaywillin

Quote: 





gibosi said:


> It seems they are not at all common. But in my experience, if I can't find something, I keep checking every day or so, and eventually they turn up....
> 
> In the meantime, triodes and heptodes are cheap and easy to find.


 

 the last pair i just bought, the rca 5915, the first time i listened, it sounded terrible, nooooo bass, i had the amp's settings wrong
  once corrected, boom, good sound ! lol


----------



## gibosi

I recently decided to try to compare two of my current favorite tubes, the Siemens EK90 (unstrapped) and RCA 6AV6. I primarily listened to Diana Krall's "From This Moment On" with a nice big brass band behind her.
   

   

   

  First some comments regarding comparing triodes and heptodes....
   
  In short, comparing triodes to heptodes is normally very difficult with the LD. Opening up the amp to change jumpers is certainly a pain. Further, once you have changed jumpers, trying to compensate for any differences in gain from memory is very imprecise. However, I now have a pair of modified socket testers, strapping pins 5 and 7, so I no longer have to open up the amp. And the fact that the LD1+ uses tubes as buffers in front of an op amp, rather than amplifiers in front of output tubes, suggests that differences in gain are not as pronounced as with the LDIII and IV. In fact, I found these tubes seemed to have virtually the same gain on my amp.
   
  While the following impressions are brief, I am hopeful they will still be of interest.
   
  I found the the Siemens and RCA very similar on the low end. Further, they are similarly bright. Where they really differ is in the mid range. The Siemens are decidedly not warm and thus the mid range has a certain thinness to it. On the other hand the mid range on the RCA is rounder and a bit warmer, and to my ear, the RCA comes out on top.
   
  Finding these two so similar, I then wondered how the RCA might compare to the Telefunken EK90.
   

   

  I found the sound stage and instrument separation on the RCA to be virtually the same as that of the heptodes. Further, all three tubes have a very similar low end, low and solid, but the Telefunken has the same thin mid range similar to the Siemens, as opposed to the rounder mid range of the RCAs.  Further, the Telefunkens are brighter than both the RCA and Siemens. The added brightness of the Telefunkens does seem to add more air, but I am not sure more air is always good as these Telefunkens are sometimes just a bit too forward for my taste. To my ear, I preferred the RCA over the Telefunkens, as well.
   
  So.... in the end, at this time, the RCA 6AV6 is my favorite tube.... for now... lol


----------



## siles1991

making me itch on buying those to try them as well haha


----------



## mordy

Hi John,
  Reading through some older posts and in one you mention that you use socket savers for the LDMKIII. Could you tell me where to get them?


----------



## mab1376

Leeds Radio 68 North 7th Street Brooklyn NY 11249 tel: 718 963-1764
   
  Test socket 7 pin miniature                           $7.00
   
http://leedsradio.com/parts-sockets.html#savers


----------



## hypnos1

Hi folks.
   
  One final(?) observation re. the Siemens EH90 tubes.
  Previously, I mentioned the superior sound coming from the pair with 'made in Germany' on, even though both pairs were supposedly Mullard (Blackburn)- made. Well, it would appear the difference is down to the one (of the non-'m.i.G') that had a very slight hum which did not disappear over time...having replaced it with another Philips-coded one (D9A, from Valvo, Hamburg).
  This one also had the wider metal laterals of the 'm.i.G.' tubes, as seen through the rectangular holes, and as shown in my post on page 134.
  Immediately the clarity; soundstage; instrument separation etc. returned, and especially the fabulous deep/tight bass...
   
  Ergo, what at first seemed to be just a minor feature of the tube - not really intrusive in any way - was in fact having a VERY detrimental effect on the quality of sound.
  Moral? I would think it is fairly safe to assume that ANY tube exhibiting such a hum (no matter how slight) - given that others are quiet - should be consigned forthwith, and replaced with as good a match - ( minus hum!!) -  as possible (hence the wisdom in never getting just a single pair, if at all possible - to my mind at least...).
   
  Happy rolling, everyone.
   
  ps. Am awaiting some Valvo EH90s, and can't wait to see how they compare to the 'Siemens'...


----------



## mordy

Fabbrica Italiana Valvole Radio Elettriche (FIVRE) was an Italian vacuum tube manufacturer that existed between 1932 and 1991. In later years they were bought up by Marelli, which produces ignition, suspension and racing parts for Ferrari and other makes. This must be the connection between FIVRE and Ferrari and the reason the boxes are red and black. (Or it could be that they copied the colors of the red and black RCA boxes since they had a long standing cooperative agreement with RCA.)

   

  So here we have the ultra rare Italian made FIVRE 6BE6 heptodes that probably were manufactured in the 50's-60's. Is this tube the Ferrari of heptodes?
   
  Burning in: The tubes were broken in at 9000RPM with a Marelli EF95 gearbox for 50 hours using the 6/7, NS, 2/7 and 1/7 gears. The air cooled engine ran cool, and no dangerous overheating occurred. While NS was a dud, the 6/7 rivaled the triodes in the very detailed treble department. The 2/7 was too treble skewed. The 1/7 gave the best acceleration times. Enough of car comparos...
   
  These tubes are bass monsters. Deep powerful bass going down very low. If there is a kick drum in the recording, you are going to hear it.The mid range coolness disappeared during burn in and was replaced by a neutral thin mid range. The treble is absolutely outstanding, allowing you to hear new nuances in the music.There is a great wide 3D sound stage with excellent spatial separation and pin point imaging. However, the treble is ruthlessly revealing. If the recording is treble skewed it will destroy it. With a technically very well made recording these tubes sound fabulous, but with lesser sound quality brightly recorded  music they become glaring. These are macho tubes without sweetness in the mid range.
   
_Edit 7/30: Another feature of these tubes that I did not come across before: Normally, when you turn up the treble or bass controls, the recording is "colored" by more treble or bass, but the the musical information is essentially the same. With these tubes, when turning up the tone controls it is like looking into a microscope; more and more details emerge in the treble and bass. (Usually when turning up or down the tone controls you hear more of or mask certain musical information, but these tubes add much more information than any others I heard. -Felt that I had to add this to the review._)
   
  Not far from where I live is a Ferrari dealer. Once the local paper interviewed a salesman there and the reported asked. "How do you sell these very expensive, impractical cars that nobody really needs, and that basically are toys for adults?" Answered the salesman: "You don't sell the car, you sell yourself. If they like you they buy."
   
  Night view of the 50 heures Le Valvole race. Notice the red hot exhaust from the four cylinder nikasil electron charged engines.

   
   
  This tube may be for people who like a superbly detailed treble and hefty bass (AFB, r u there?) but personally I prefer a warmer, sweeter, more musical tube. With certain recordings it really shines, but the wow factor only comes through here and there.


----------



## MIKELAP

Quote: 





mordy said:


> Fabbrica Italiana Valvole Radio Elettriche (FIVRE) was an Italian vacuum tube manufacturer that existed between 1932 and 1991. In later years they were bought up by Marelli, which produces ignition, suspension and racing parts for Ferrari and other makes. This must be the connection between FIVRE and Ferrari and the reason the boxes are red and black. (Or it could be that they copied the colors of the red and black RCA boxes since they had a long standing cooperative agreement with RCA.)
> 
> 
> 
> ...


 
  Magnifico signor mordy


----------



## rosgr63

Very nice indeed.
   
  BTW SICTE and ATES also used red and black boxes.
  FIVRE were based in Milano.
   
  Marconi Italiana used Blue and red boxes.
   
  Zenith had a factory in Monza.


----------



## mordy

Mikelap,
   
   
  Pardon, è Mordicci, non Mordy


----------



## MIKELAP

Quote: 





mordy said:


> Mikelap,
> 
> 
> Pardon, è Mordicci, non Mordy


 
  scusa mi signor Mordicci


----------



## siles1991

Received my TS 6AH6WA!!!! numbers 6745 and 6734 not sure what they mean. 2 different sets of numbers on 1 tube.


----------



## gibosi

Quote: 





siles1991 said:


> Received my TS 6AH6WA!!!! numbers 6745 and 6734 not sure what they mean. 2 different sets of numbers on 1 tube.


 
   
  It is hard to say... My best guess is these are dates: 1967, week 45 (November 6-12, 1967) and 1967, week 34 (August 21-27, 1967). To add to the mystery, "A 9/67" is printed on the box (It appears that I have the same tubes). 
   
  While I think it is safe to say that your tubes were manufactured in 1967, I do not know what events these various dates correspond to....


----------



## mordy

Most likely the dates on the tubes are the manufacturing dates; 9/67 is the intended packing/shipping date. Sometimes there could be more than a year's difference between the manufacturing date and the shipping date on the box forward or backwards in time!
   
  Reading your post again I now realize that both numbers appear on the same tube. I have the same situation with my TS 6AH6WA tubes. One tube reads    6
                                                                                     301
                                                                                  U.S.A. 7
                                                                              JTL-6AH6WA
                                                                              6316
   
  IMHO this means manufactured 1st week of 1963 in the US factory #7.
  JTL is the military designation for Tung Sol. 6AH6 is the tube type, the W means ruggedized, and A means revision A of the tube (usually revisions were minor changes such as the time needed to heat up etc). [I don't have the original box].
  6316 is the packing date - week 16 1963.


----------



## jaywillin

tomorrow some new tubes i ordered should be here,
  when i've had tube amps before in my hi-fi rig, i'd keep reading about mullard tubes, so when i saw these, i bit
  http://www.ebay.com/itm/221258929156?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649


----------



## mordy

HI jaywillin,
   
  When you burn in these tubes, be prepared that the amp will run very hot. Nothing to worry about, but the EF91/92 tubes run hotter than any of the tubes.


----------



## jaywillin

Quote: 





mordy said:


> HI jaywillin,
> 
> When you burn in these tubes, be prepared that the amp will run very hot. Nothing to worry about, but the EF91/92 tubes run hotter than any of the tubes.


 

 i'll keep that in mind, thanks !!


----------



## jaywillin

i've been meaning to ask, and maybe i should search first, now that i'm getting more tubes, new, and not burned in
  is there a the proper procedure, or limits i should be aware of, not that i'd be leaving an amp, or anything powered up and running
  all day, , but i don't want to blow or burn anything up ! lol

   edit:
   
  just did a quick search, there does seem to be plenty of info on the subject , and if "burn in" even really is needed, beneficial
  i do realize tubes need to warm up, that they often make noises until the temp stabilizes


----------



## mab1376

Quote: 





jaywillin said:


> i've been meaning to ask, and maybe i should search first, now that i'm getting more tubes, new, and not burned in
> is there a the proper procedure, or limits i should be aware of, not that i'd be leaving an amp, or anything powered up and running
> all day, , but i don't want to blow or burn anything up ! lol
> 
> ...


 
   
  LittleDot recommends no more than 8 hours at a time.
   
  Usually people will play pink noise during the duration of the burn in, I personally just play music.


----------



## siles1991

I was wondering how do you guys clean the pins for the NOS tubes you get?


----------



## inphu510n

siles1991 said:


> I was wondering how do you guys clean the pins for the NOS tubes you get?




I'm a nutcase about this. I prefer to clean all of my tubes pins with the backside of an xacto blade. Scraping that many pins with that method is a serious pain.
I recently read about using 99% alcohol. I ordered and tried it with no luck. Maybe I just need to soak the pins for a few hours...
I'm considering just ordering something like this though.


----------



## siles1991

I currently am using a dremel tool with wire brush tip but need to find a better quality tip, this one flings stray wire at me...


----------



## inphu510n

siles1991 said:


> I currently am using a dremel tool with wire brush tip but need to find a better quality tip, this one flings stray wire at me...




Previous experience with those stupid tips confirms your report.


----------



## mordy

LittleDot recommends no more than 8 hours at a time.
   
  In the interest of furthering the knowledge of the various tubes it is necessary to burn them in for extended periods before evaluating them, or using them to their full potential. IMHO heptodes require about 50 hours, others more (120 hrs) or less (30hrs).
   
  The reason why there is an 8hr recommendation of use is because of heat build up. If the tubes run cool, your amp is well ventilated on cones or whatever, and under EF92 conditions with a little computer fan blowing hot air away from the amp, IMHO the amp can stay on for very long periods. I mean, 48 hours is two full days, and then the next set of tubes to burn in for another 48 hours....
   
  I use my iTunes program with continuous play with all kinds of music for burning in.
   
  During long runs, as long as the amp feels slightly warm to the touch am not worried. If it gets quite hot I turn the fan on but usually I don't need to do it.


----------



## gibosi

Siemens EK90 and EH90
   
  With all the different versions of Siemens EK90 and EH90 we have seen recently, no one really knows which are "real" and which are simply rebranded. While I am not sure I am any closer to answering this question, I think I have made a little progress in clearing away some of the haze.
   
  I have Siemens and Siemens-Haltron EK90 with ribbed plates that might be "real". However, since there are no tube codes or any other markings which can be used to trace them directly to the Halske factory, I can't be sure. Even though I am not sure that either of these are real Siemens, all of us who have these tubes find them to be top tier tubes. In the end, what's good is good, and it really doesn't matter who made them. And so I got to thinking that if I could find a pair of Siemens EH90 from the same factory, where ever this factory might have been, they too might be similarly excellent.
   
  I have four different Siemens EH90 tubes, all singles. Comparing them under a magnifying glass with my Siemens EK90, I have come to the conclusion that the Siemens EH90 with ribbed plates, "EH90" etched into the glass and "foreign" printed on the glass, very likely came out of the same factory as my Siemens EK90.
   
  The Siemens EK90 is to the left and the "Foreign" Siemens EH90 is to the right:
   

   

   

   

  So those of you who have these "foreign" Siemens EH90s... What say you? How do these tubes sound?


----------



## jaywillin

the mullards got here yesterday, they are burning in


----------



## inphu510n

jaywillin said:


> the mullards got here yesterday, they are burning in




What date codes are those?


----------



## joseph69

I posted in the Grado fan club by accident, but my Voskhod 6J1P-EV's got here yesterday and I just put them in today, so I will be listening for a while with the 325's as they burn in.
  Anybody have an idea how long burn in is for these tubes approximately?
  Also, after burn in, *jaywillin, *let us know how you like the Mullard, and I will do the same.
  Funny thing just happened while I'm replying to this post... my cell phone was ringiing, but I didn't answer, but I paused playback out of my MBP to see who was calling, and put the phone back down (which is next to the LD) and the caller left a message, which interfered with the right driver as I was notified by the alert tone, and immediately after that during playback I received another call and while the phone was ringing it also interfered through the right driver, this never happened with the Siemens 6AK5W's, and always have the cell phone in the same place, (next to the LD)... Any comments or suggestions?


----------



## gibosi

Quote: 





jaywillin said:


>


 
   
  Your amp doesn't have the brass rings surrounding the tubes but black posts instead?


----------



## joseph69

I have the same (tube cages) on my LD, the posts for the cages replace the brass rings, From what I understand it was an upgrade on the LD.


----------



## rosgr63

Were the posts factory fitted?


----------



## mordy

Hi Gibosi,
   
  I have a pair of the Siemens EH90 Foreign. These tubes are superb, maybe the pinnacle (pun intended) of heptodes; certainly in the very top tier. Need more time to sort out the different settings before i will write a review.


----------



## mordy

Hi joseph69,
   
  The Voskhods need around 110-120 hours to burn in; more than any other tube I tried. At that stage there is a very substantial change with a lot of the harshness going away.
  Patience, patience.


----------



## inphu510n

gibosi said:


> Your amp doesn't have the brass rings surrounding the tubes but black posts instead?




That's really odd. There looks like another set of holes near these black posts. The spacing of the posts looks very similar to the spacing for these.


----------



## joseph69

Quote: 





rosgr63 said:


> Were the posts factory fitted?


 
  Yes the tubes are native, (factory fitted), after that happened I also noticed when I stopped playback and lowered the volume on iTunes and the LD all the way, I was moving my cursor and heard interference through both L/R drivers, and then again without moving the cursor it happened again, so I moved my cellphone away from the LD, but that had no effect, then the interference just went away. Do you know if it would be safe (just for lubrication purposes and ease of changing tubes) to use a little white grease on the pins?
  BTW, I am also using the Magni with the LD and MBP, but like I said this never happened with the Siemens 6AK5W's. Could this possibly be because the tubes are brand new?


----------



## joseph69

Quote: 





rosgr63 said:


> Were the posts factory fitted?


 
  Sorry, I thought you where referring to the pins on the tubes from my other post. I'm not certain that the tube cage posts are from LD, but the fitment is fine, I purchased this amp from eBay from a U.S. dealer, the description read: comes with upgraded Siemens 6AK5W's and tube cages, so I don't know if LD does this at the factory, but this was NIB.


----------



## joseph69

Quote: 





mordy said:


> Hi joseph69,
> 
> The Voskhods need around 110-120 hours to burn in; more than any other tube I tried. At that stage there is a very substantial change with a lot of the harshness going away.
> Patience, patience.


 
  Thanks for the reply, I've never found my 325's harsh in any way at all, and even with my first listen (right now as I am replying) they are not harsh at all. I originally purchased these tubes because I had read that they were one of the clearest, upfront sounding tubes, which is what I'm looking for, for my 325's, also I didn't want to start strapping just yet, I wanted a native tube. Thanks for your reply again.


----------



## Acapella11

Quote: 





gibosi said:


> So those of you who have these "foreign" Siemens EH90s... What say you? How do these tubes sound?


 
   
  Open with good detail and focus albeit not as good instrument separation as my Siemens EK90. Toe tapping. Slightly cooler than my Siemens EK90. Tonal balance is shifted towards treble, which is extended and very well presented. However, it lacks the appropriate bass weight for a good balance. Overall, it is a good tube specifically if you are into treble. I have tubes I favour over this one though.


----------



## joseph69

Quote: 





inphu510n said:


> That's really odd. There looks like another set of holes near these black posts. The spacing of the posts looks very similar to the spacing for these.


 
  There aren't any other holes next to the posts, there are screws for the top cover in front of the cages, maybe thats what you see, and these cages look very similar to mine, with the exception that my black cages only have one ring on the top, but they look like they would use the same mounting holes.


----------



## inphu510n

joseph69 said:


> Yes the tubes are native, (factory fitted), after that happened I also noticed when I stopped playback and lowered the volume on iTunes and the LD all the way, I was moving my cursor and heard interference through both L/R drivers, and then again without moving the cursor it happened again, so I moved my cellphone away from the LD, but that had no effect, then the interference just went away. Do you know if it would be safe (just for lubrication purposes and ease of changing tubes) to use a little white grease on the pins?
> BTW, I am also using the Magni with the LD and MBP, but like I said this never happened with the Siemens 6AK5W's. Could this possibly be because the tubes are brand new?




Obviously this is RF based interference being caused by other devices near your amp. I've heard exactly what you're talking about with different setups. It's interesting that some tubes reject this interference more than others. I'm wondering if the more "ruggedized" tubes will reject more RF.

I think another thing that you're hearing is noise from your MBP being passed through the Schiit. It sounds almost like the USB transmissions from your mouse are making it through it. Try moving the Schiit to the other USB bus on the MBP (you have three USB ports right?)
I have the Modi and haven't experienced this yet.
I have however seen my amp wreak havoc on a pair of RF based Sennheiser remote headphones.
Once you understand what the tubes are actually doing on an electrical level, you become surprised that they're not affecting more RF sensitive stuff around you.


----------



## rosgr63

Quote: 





joseph69 said:


> Yes the tubes are native, (factory fitted), after that happened I also noticed when I stopped playback and lowered the volume on iTunes and the LD all the way, I was moving my cursor and heard interference through both L/R drivers, and then again without moving the cursor it happened again, so I moved my cellphone away from the LD, but that had no effect, then the interference just went away. Do you know if it would be safe (just for lubrication purposes and ease of changing tubes) to use a little white grease on the pins?
> BTW, I am also using the Magni with the LD and MBP, but like I said this never happened with the Siemens 6AK5W's. Could this possibly be because the tubes are brand new?


 
   
  I have used Silclear and Caig Deoxit Gold to lubricate the pins.
  Some people don't like Silclear but it works fine for me.
   
  I think you may have a USB transmission problem as mentioned above by inphu510n


----------



## mordy

"My goal is to make a amp that sounds great with the cheapest tubes - *2359glenn*"
   
  Isn't this the purpose of this forum?


----------



## joseph69

Quote: 





inphu510n said:


> Obviously this is RF based interference being caused by other devices near your amp. I've heard exactly what you're talking about with different setups. It's interesting that some tubes reject this interference more than others. I'm wondering if the more "ruggedized" tubes will reject more RF.
> 
> I think another thing that you're hearing is noise from your MBP being passed through the Schiit. It sounds almost like the USB transmissions from your mouse are making it through it. Try moving the Schiit to the other USB bus on the MBP (you have three USB ports right?)
> I have the Modi and haven't experienced this yet.
> ...


 
  I have 2 USB ports on the MBP, the other port is for firewire, but I will try switching the Schiit to the other USB port, also I'm using the mouse pad that is built into the MBP so I'm not using the other USB port for that purpose. Thanks for your input with my situation, I will do more listening later and see if it happens again, thanks.


----------



## joseph69

Quote: 





rosgr63 said:


> I have used Silclear and Caig Deoxit Gold to lubricate the pins.
> Some people don't like Silclear but it works fine for me.
> 
> I think you may have a USB transmission problem as mentioned above by inphu510n


 
  So I guess it would be safe to put a little bit of white grease on the pins, being that I use it on other types of electrical connections, I just wasn't sure if it was ok for the amp, but if other people are using some type of lubricant at least I know I can lube them, thanks.


----------



## jaywillin

Quote: 





gibosi said:


> Your amp doesn't have the brass rings surrounding the tubes but black posts instead?


 

 it has the tube cages it was a little difficult changing some tubes with the rings on, so, just took them off, left the posts on


----------



## jaywillin

Quote: 





inphu510n said:


> What date codes are those?


 

 1022-907 i assume this is the code ??


----------



## jaywillin

Quote: 





joseph69 said:


> Yes the tubes are native, (factory fitted), after that happened I also noticed when I stopped playback and lowered the volume on iTunes and the LD all the way, I was moving my cursor and heard interference through both L/R drivers, and then again without moving the cursor it happened again, so I moved my cellphone away from the LD, but that had no effect, then the interference just went away. Do you know if it would be safe (just for lubrication purposes and ease of changing tubes) to use a little white grease on the pins?
> BTW, I am also using the Magni with the LD and MBP, but like I said this never happened with the Siemens 6AK5W's. Could this possibly be because the tubes are brand new?


 

 i bought this amp used, but it looks to be the same as the factory upgrade


----------



## joseph69

Yes, I believe you posted photos of your LD and we do have the same tube cages, but I don't know if they come from China this way, because I bought mine from a dealer in the states, and I think he upgraded it with the tubes and cages.
  How do you like the Mullard tubes so far?


----------



## britt2001b

It's been a while since I have bought any tubes for my Little Dot MKIII headphone amp, but when I saw a couple of the large shield m8161 Mullards on sale for only $8.95 each it seemed a fair price and decided to give 'em a go. I must say, these sound better than any that I currently own (including the small shield Mullards purchased from another seller many months ago). I wasn't expecting a big difference but I was pleasantly shocked that the larger shields sound so much better to me.
   
  This thread has taught me that the same tubes can perform differently on various equipment (and to the listener's personal expectations). I think I have found my primary "go to" tubes, so I ordered another pair for back ups. I really don't want go through a period of not having these.
   
  My primary listening gauge recordings are from the entire Beatles catalog as I have been playing them since 1964. I am hearing things that I have not heard before from these recordings, mostly room ambience. The music is literally bouncing off the walls of the EMI studios in a way that I have never heard before. The sound is warm, full, and alive as if it was recorded yesterday.
   
  I remember reading a recommendation from David over at the "Little Dot" forums that you will not find a better sounding tube than the Mullard m8161's. I now agree with that statement. I'm curious though, why the larger shield m8161's sound different (better to me) than the smaller shield version?


----------



## joseph69

Are these tubes native to the LD1+, without strapping, so they plug right in and play? If yes,
  would you be able to tell me were I can purchase the Mullard M8161 tubes with the large shield you are tailing about, so I can order a pair right now for myself to hear? Thanks.


----------



## gibosi

Quote: 





joseph69 said:


> Yes, I believe you posted photos of your LD and we do have the same tube cages, but I don't know if they come from China this way, because I bought mine from a dealer in the states, and I think he upgraded it with the tubes and cages.


 
   
  Regarding the tube cages, it appears that they are not currently available from Little Dot as an upgrade as I see no mention of these on the Little Dot web site:
   
  http://www.littledot.net/forum/viewtopic.php?f=9&t=819&sid=c93e8fba83890de6fef82c2f2efb986b
   
  That said, perhaps at some time in the past tube cages were offered as an upgrade....


----------



## gibosi

Quote: 





britt2001b said:


> I remember reading a recommendation from David over at the "Little Dot" forums that you will not find a better sounding tube than the Mullard m8161's. I now agree with that statement


 
   
  With all due respect, there are in fact quite a few tubes that sound significantly better......


----------



## joseph69

Quote: 





gibosi said:


> Regarding the tube cages, it appears that they are not currently available from Little Dot as an upgrade as I see no mention of these on the Little Dot web site:
> 
> http://www.littledot.net/forum/viewtopic.php?f=9&t=819&sid=c93e8fba83890de6fef82c2f2efb986b
> 
> That said, perhaps at some time in the past tube cages were offered as an upgrade....


 
  Was going to search that next, thanks for the info.


----------



## jaywillin

Quote: 





joseph69 said:


> Yes, I believe you posted photos of your LD and we do have the same tube cages, but I don't know if they come from China this way, because I bought mine from a dealer in the states, and I think he upgraded it with the tubes and cages.
> How do you like the Mullard tubes so far?


 

 even though i've had the amp on with music playing, i haven't listened a whole lot yet, but the first thing that jumps out at me is they may be a little bright, a little hard in the treble
  the bass seems good, detail is very good, instrument separation, and texture very good, just initial thoughts though, i can say they sound much better now than at first listen this morning
  how about your new russians ?


----------



## joseph69

Quote: 





jaywillin said:


> even though i've had the amp on with music playing, i haven't listened a whole lot yet, but the first thing that jumps out at me is they may be a little bright, a little hard in the treble
> the bass seems good, detail is very good, instrument separation, and texture very good, just initial thoughts though, i can say they sound much better now than at first listen this morning
> how about your new russians ?


 
  I just put mine in this afternoon and by now I have about 6 hours on them, so my initial impression is that they sound pretty much like the Siemens 6AK5W's did when I first got them, but they have many more hours on them now and at this point sound more warmer, airy and detailed, so I do like the Siemens, but I can't compare the two tubes yet, but right now they sound ok, but I also understand the Voskhod I have take approximately 100 hrs to burn in. This is probably the only thing that may side track me from tube rolling is that I just can't turn on the amp and listen to it in its mature state, where as the Magni I can, but I'm not about to abandon this amp because of this, I'll hang in and wait it out, I'm hoping it will be worth the wait after all is said and done. What you described with the tubes you just recieved, sounds like I may like them for myself. What tubes did you recently put in that you are talking about, I would like to try these also?


----------



## jaywillin

Quote: 





joseph69 said:


> I just put mine in this afternoon and by now I have about 6 hours on them, so my initial impression is that they sound pretty much like the Siemens 6AK5W's did when I first got them, but they have many more hours on them now and at this point sound more warmer, airy and detailed, so I do like the Siemens, but I can't compare the two tubes yet, but right now they sound ok, but I also understand the Voskhod I have take approximately 100 hrs to burn in. This is probably the only thing that may side track me from tube rolling is that I just can't turn on the amp and listen to it in its mature state, where as the Magni I can, but I'm not about to abandon this amp because of this, I'll hang in and wait it out, I'm hoping it will be worth the wait after all is said and done.


 

 just speaking for myself, i like have a tube amp, and a solid state, especially at this price point.
  the two amps you have, if you do decide to let one go, you should be able to get a good price for them, they are both very popular


----------



## joseph69

I really don't think I'm going to let either of them go, I do like them both so you know that goes.
  BTW, what tubes did you just put in, I would like to try these tubes for myself, because you mentioned they are bright, also do they have a forward mid range presentation, as an initial impression?


----------



## britt2001b

Quote: 





joseph69 said:


> Are these tubes native to the LD1+, without strapping, so they plug right in and play? If yes,
> would you be able to tell me were I can purchase the Mullard M8161 tubes with the large shield you are tailing about, so I can order a pair right now for myself to hear? Thanks.


 
   
  I don't know if they are plug and play with the LD1 without strapping. I purchased these from a seller on Ebay. Here is the link to the posting, although it appears that he has ended the sale. It says six have been sold but there are more than six in the photo. Perhaps a new sale is coming?
   
http://www.ebay.com/itm/161073092725?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649


----------



## joseph69

Thank you, I will take a look at the link and get more information, thanks again.
  Just checked it out and the auction reads: Has ende because the item is no longer available, so I'll just have to wait and see. Thanks.


----------



## jaywillin

Quote: 





joseph69 said:


> I really don't think I'm going to let either of them go, I do like them both so you know that goes.
> BTW, what tubes did you just put in, I would like to try these tubes for myself, because you mentioned they are bright, also do they have a forward mid range presentation, as an initial impression?


 

 i was referring to the mullards that i had just bought and had been burning in today
  http://www.ebay.com/itm/221258929156?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649
  they've only got about 8 hours on them , and the brightness isn't extreme, and its smoothed out a bit since first listening earlier today
  but so far, i really like this pair


----------



## britt2001b

Quote: 





gibosi said:


> With all due respect, there are in fact quite a few tubes that sound significantly better......


 
   
  The better sounding tubes within my inventory are the Sylvania Gold Brand, gold pins 5654, the Sylvania Jan 5654, the Voskhod 6zh1p-ev, and the Mullard m8100. All of these sound wonderful and with these I believed that I had reached the pinnacle of the better tubes for the Little Dot MkIII. The "large shield" Mullards were ordered because the lower price allowed my curiosity. I firmly believe tubes will behave differently from variant equipment, source material, headphones, personal preferences, etc.
   
  The Mullard "large shield" m8161's must be a good match with my set up. I just don't know how it could sound any better to my ears!


----------



## mordy

Welcome back,  britt2001b,
   
  "With all due respect, there are in fact quite a few tubes that sound significantly better......" (Gibosi)
   
  This is really true. Many times I had in mind to email David Zhe Zhe and encourage him to try the new wonderful, cheap and plentiful tubes that the trailblazers on this forum have discovered. However, every time I tried a new great tube, another, better tube appeared. The jury is still out, but at some time there is definitively going to appear a list of the best examples.
   
  We are not speaking of an upgrade over the standard tubes, but a double or triple upgrade!
   
  I have to confess that I have become a heptode convert....... One of the most objective and scientific methods I use in evaluating tubes is involuntarily toe tapping. On a scale from 1 to 5, where 5 is the highest, my Siemens EH90 678 Foreign tubes (of unknown manufacture) elicit a 5+._ (Please note that this comment is a serious joke - many a true word is said in jest.)_


----------



## rosgr63

Quote: 





mordy said:


> "My goal is to make a amp that sounds great with the cheapest tubes - *2359glenn*"
> 
> Isn't this the purpose of this forum?


 
   
  Sorry you feel this way and you are attacking me.
  That statement is in my signature neither a post nor a comment.
   
   BTW I have been posting tube rolling in the LD official site a long time ago, before you joined Head-Fi.


----------



## mordy

Been through all the 6AK5 variants that you describe. (BTW the Sylvania Gold Brand 5654 with gold pins sound identical to the JAN 5654; only the price is very different), the Voskies and Mullards. I finally settled on the Tung Sol 6AJ5 tube and thought that I am finally done, being perfectly satisfied with the sound.
   
  Then the guys on this forum started experimenting with new tubes and strap mods. In the beginning I was afraid to try the new stuff; after all I was perfectly happy with what I had. When the price was right I bought some cheap tubes (under $3 each) and tried the 6AH6 and 6AU6 families. I was blown away! (There are many posts picking the best variants).
   
  Then there was another type of tube that came up: Heptodes. Another trip to the inexpensive sellers on Ebay and more revelations. Each heptode has to be tried just plugged in + three different wire mod straps to ferret out the best setting for you.
   
  If good is good, then certainly better is better.... After all this, I can't go back to the 6AK5 stuff. The new tubes are so much better....


----------



## joseph69

Quote: 





jaywillin said:


> i was referring to the mullards that i had just bought and had been burning in today
> http://www.ebay.com/itm/221258929156?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649
> they've only got about 8 hours on them , and the brightness isn't extreme, and its smoothed out a bit since first listening earlier today
> but so far, i really like this pair


 
  Thanks, I'm going to place an order for these, this way I will have 3 different tubes to compare.


----------



## mordy

Dear rosgr63,
   
  I would never dream of attacking anybody on this forum. I really enjoy this forum with all the great and knowledgeable people participating and helping each other, including you. No one criticizes anybody else.
   
  I thought it was a great quote and liked it very much. I made it a point not to pay more than $8/tube and so far only broke the rule once when I recently ordered the 6N6P-IR tubes that people recommend.
   
  I find it very interesting scanning the internet for good buys on tubes, and I was happy to see a quote from somebody who has the same thinking as me. There is really no need to pay $85 for tubes that you can find for much less with a little patience.
   
  Please accept my apology if I wrote something offensive - I had absolutely no such intentions whatsoever.
   
  BTW, the picture that you use with the two amps with a lot of tubes, what kind of equipment is it?


----------



## joseph69

*jaywillin*, are these tubes native to the LD1+ without strapping, can I just plug them in? I would rather have some tubes I can just plug in for starters rather than strap, so I just want to make sure before I click BIN, thanks.


----------



## jaywillin

joseph69 said:


> *jaywillin*, are these tubes native to the LD1+ without strapping, can I just plug them in? I would rather have some tubes I can just plug in for starters rather than strap, so I just want to make sure before I click BIN, thanks.



Native 
I haven't tried strapping yet, all the tubes I've used I've just plugged right in


----------



## gibosi

Quote: 





rosgr63 said:


> Sorry you feel this way and you are attacking me.
> That statement is in my signature neither a post nor a comment.
> 
> BTW I have been posting tube rolling in the LD official site a long time ago, before you joined Head-Fi.


 
   
  It would appear that someone got up on the wrong side of the bed....


----------



## joseph69

Quote: 





jaywillin said:


> Native
> I haven't tried strapping yet, all the tubes I've used I've just plugged right in


 
  Thanks, I'm going to order a pair right now.
  Native, meaning they are a direct plug in with no strapping.


----------



## siles1991

I finally plugged in my TS 6AH6WA, gonna be the last day for me with my mkiii selling it for the mkiv se haha! Well the TS's are really amazing...I think I prefer them over the valvo's I have ^_^ has such an open sound


----------



## jaywillin

joseph69 said:


> Thanks, I'm going to order a pair right now.
> Native, meaning they are a direct plug in with no strapping.



Strapping is coming , I can feel it!


----------



## hypnos1

Quote: 





rosgr63 said:


> Sorry you feel this way and you are attacking me.
> That statement is in my signature neither a post nor a comment.
> 
> BTW I have been posting tube rolling in the LD official site a long time ago, before you joined Head-Fi.


 
   
  Hi rosgr63.
   
  Yes indeed, you have been a valued contributor for a good long while... but please, come on, how on earth could you take offence at mordy's post? I urge you to look back over the many posts since the good ol' Voskhod days and the regular contributions of such as mordy, and you will see the all-encompassing goodness/helpfulness (not to mention occasional playfulness!) of said contributors.
   
  I believe (nay hope) you will then come to a somewhat different understanding...
   
  Sincerely,
  CJ


----------



## joseph69

Quote: 





jaywillin said:


> Strapping is coming , I can feel it!


 
  Yes, definitlry in the near future, I just want to try a few different tubes before I start strapping.


----------



## MIKELAP

Quote: 





gibosi said:


> It would appear that someone got up on the wrong side of the bed....


 
  +1 on that


----------



## gibosi

Quote: 





joseph69 said:


> Thanks, I'm going to order a pair right now.
> Native, meaning they are a direct plug in with no strapping.


 
   
  For the benefit of our newer members.... Most heptodes sound very good to excellent with no strapping at all. That is, you can "pretend" that they are native EF95. Moreover, you can also "pretend" that they are native EF91/92. (However, most of us consider the EF95 setting to be superior.)  And at some point in the future, you may want to try some of these heptodes strapped... or not....


----------



## joseph69

Quote: 





gibosi said:


> For the benefit of our newer members.... Most heptodes sound very good to excellent with no strapping at all. That is, you can "pretend" that they are native EF95. Moreover, you can also "pretend" that they are native EF91/92. (However, most of us consider the EF95 setting to be superior.)  And at some point in the future, you may want to try some of these heptodes strapped... or not....


 
  Not quite understanding you, did I use the wrong term by saying (native), I am new to the tube rolling scene, so I don't know much about it, when I do have the spare time I try to keep up with the thread though.


----------



## gibosi

Quote: 





joseph69 said:


> Not quite understanding you, did I use the wrong term by saying (native), I am new to the tube rolling scene, so I don't know much about it, when I do have the spare time I try to keep up with the thread though.


 
   
  To my knowledge "native" is not a well-defined word in the LD world, so no, you did not use the wrong term. Since it is not a well-defined word, I would guess that most new users think "native" means EF91, EF92, EF95 and for the LD 1+, 408A. as these are the only tubes listed in the LD manual. And therefore, I wanted to make it clear that a heptode can be treated like an EF95 or EF91/92.
   
  I tend to use the term "natively compatible" for tubes that are "plug and play", and therefore, tubes that* require* strapping, or some other mod, are not "natively compatible". The 6AU6 and 6AH6 are strictly not natively compatible. They must be strapped. Triodes require that pins be removed. They too are not natively compatible. But heptodes are more complicated. They can be treated as a natively compatible tube, like a 6Ak5. Or they can be treated as if they are not natively compatible, and strapped.
   
  As the use of these new tubes in Little Dots is all very recent, those of us in this forum are making this terminology up as we go along, so the last thing you should worry about is if you used the "wrong term". In the end, all that is important is that we can clearly understand each other.
   
  Cheers,


----------



## joseph69

Thanks for the info, I appreciate your explaining to me.


----------



## jaywillin

i'll throw in some thanks too !! i'm sure it can get a tad irritating or frustrating answering so many "newbie" especially when its been answered many times before and us noobs haven't read the threads yet. just know ya'lls patience and willingness to share your knowledge is appreciated , i've been more active in grado thread, and here, and the feeling , vibe is very cool here. thanks again guys !!--- jay
  jay


----------



## gibosi

Quote: 





siles1991 said:


> I finally plugged in my TS 6AH6WA, gonna be the last day for me with my mkiii selling it for the mkiv se haha! Well the TS's are really amazing...I think I prefer them over the valvo's I have ^_^ has such an open sound


 
   
  These Tung-Sols are one of my primary reference tubes. So when I find a tube that sounds as good or even better than they do, I know that I have a real winner.
   
  Enjoy!


----------



## Acapella11

Quote: 





mordy said:


> Welcome back,  britt2001b,
> 
> I have to confess that I have become a heptode convert....... One of the most objective and scientific methods I use in evaluating tubes is involuntarily toe tapping. On a scale from 1 to 5, where 5 is the highest, my Siemens EH90 678 Foreign tubes (of unknown manufacture) elicit a 5+._ (Please note that this comment is a serious joke - many a true word is said in jest.)_


 
   
  Hey Mordy, how is your toe doing?  Or on a more serious note, how did you find them? Gibosi, have you got this tube as well? Seems people are cautious responding with impressions...


----------



## gibosi

Quote: 





acapella11 said:


> Hey Mordy, how is your toe doing?  Or on a more serious note, how did you find them? Gibosi, have you got this tube as well? Seems people are cautious responding with impressions...


 
   
  I have only one of these "foreign" Siemens EH90, and thus I have no idea how they sound. So naturally, I too want to know what people think of this tube. In the meantime, I am busy searching for a second one....


----------



## MIKELAP

Quote: 





gibosi said:


> I have only one of these "foreign" Siemens EH90, and thus I have no idea how they sound. So naturally, I too want to know what people think of this tube. In the meantime, I am busy searching for a second one....


 
  i am running a pair Siemens EH90 ¨foreign¨ with about 23 hours on them tried them with EF95,EF91-92, AND EF95 1/7 -socket wire mod and best sounding setting to me is the EF95 1/7-socket wire mod with senns hd800 reminds me of the 6av6 tubes very clean sounding detailed with tight bass soundstage  maybe not as wide as 6av6 tubes very nice sounding tube


----------



## mordy

Hi A11,
   
  Here is the link to the guy I bought them from. Looks like me and Mikelap got the last ones because he does not have any more for sale. I am in the middle of burning them in and will write my impressions when I am finished testing all the combinations.
   
  Here is the link:
  http://stores.ebay.com/haunebuvintage/
  
  A curiosity - did anybody else notice this? After changing jumper settings sometimes the first impression is forget it - does not sound good. If you leave the tubes on an hour or two on that setting and listen again, suddenly they sound much better. It as if the tubes need time to settle in into the new environment to come to their full potential.
   
  I heard that people who grow flowers talk to them. Maybe I should talk to mine to make them sound better after they have been replanted?


----------



## mordy

Hi Mikelap,
   
  Re the Siem EH90s, I am one lap ahead of you cause I am nearing the 35 hr mark. In all seriousness, and in the interest of scientific exploration, did you try the 2/7 strap yet? (Did not yet try it myself)


----------



## mordy

Hi All,
   
  Here is a review of the Sylvania 6CS6 (EH90) tube after appr 60 hours of burn in. (Once I was in a shoe store Midwest and saw a sign that said: "Near Pair".  Apparently, somebody had sold someone 2 different sizes, and what was left was a 7 and a 71/2; thus "near pair." )
  The Sylvanias are both 6CS6, but the etching of the designation is a little bit different on the two tubes. Likewise, the boxes are slightly different in color. The tubes otherwise look the same, and sound the same. My assumption is that they can be viewed as a pair, but from two different production runs. Take a look:
   

   

   

   

   
  It was a challenge to find a pair at a good price, but ended up paying less than $6 for the pair, including shipping. Was not able to decipher the dates, but it is safe to say that the tubes are from the 50's-60's.
   
  In my 18 months odyssey to find the perfect 6AK5 tube I learned a lot of things. My conclusion about "house sound" is that there are "house traits" instead. The Sylvanias stood out as the sound stage champions. These 6CS6 tubes have the widest sound stage I've heard so far.
   
  I have a recording with a clarinet and banjo solo. Most tubes place the banjo on the right, and the clarinet in the middle, which makes this very nice recording annoying to listen to. It's like half a sound stage. These tubes place the banjo outside the speakers on the right, and the clarinet all the way to the left. Amazing.
   
  Now for listening impressions: EF95 1/7 and 2/7 - nothing special; mid range OK, lacking in rhythm and pace. 
   
  EF 92 (done on EF95 6/7 setting): Quite good bass, mid range, rhythm and pace, but too skewed towards the treble; too sibilant on many recordings.
   
  EF95 NS (no strap-plug and play): This is it! Viva la Heptode! Excitement, musicality, good rhythm, pace and timbre. Very good bass with excellent slam and attack, but not the deepest bass.Brings out the essence of the music without excessive analytical detail. Superb instrument separation and imaging. Mid range very good, treble detailed.
   
  Cons: The tubes are very sensitive to the recording quality, and you immediately hear the differences in the recording venue. There is a peculiar and curios ability to overdose on the treble on certain bright recordings, making them unpleasant to listen to. Can't figure out what level of treble or type of recording triggers this response.
   
  Summary: Not the ultimate in bass and treble presentation, but very pleasant, warm, musical tubes with a full bodied sound with an enormous sound stage. Recommended.


----------



## inphu510n

mordy said:


> A curiosity - did anybody else notice this? After changing jumper settings sometimes the first impression is forget it - does not sound good. If you leave the tubes on an hour or two on that setting and listen again, suddenly they sound much better. It as if the tubes need time to settle in into the new environment to come to their full potential.
> 
> I heard that people who grow flowers talk to them. Maybe I should talk to mine to make them sound better after they have been replanted? :atsmile:




This is interesting. I could swear I've heard a similar thing happen with a number of tubes. Whatever I *might* be hearing, apparent in the bass section. I also seem to think that there's a sweet spot between the tubes not having been on long enough and then having been on for too long.
I've been wondering if I'm insane. Some times it seems like the issue doesn't happen at night, far more toe tapping happens then for me. Maybe it's some sort of electrical interference caused during the day?

Maybe it's time I go see a doctor...


----------



## bruce108

Quote: 





> Some times it seems like the issue doesn't happen at night, far more toe tapping happens then for me. Maybe it's some sort of electrical interference caused during the day?


 
   
  That's maybe your power supply: the more people using the grid, the dirtier the domestic power. Late night is definitely better here on whatever equipment.


----------



## mordy

Hi inphu510n,
   
  There is nothing wrong with you. (Don't waste money on a doctor visit!) During the day there is a lot of electrical interference from various lights, appliances, portable phones etc. This produces electrical grunge (RF interference) that has an impact on the sound.
   
  As mentioned, these things tend to be happening much less at night, and the sound improves.
   
  As also mentioned, an A/C line conditioner from a reputable manufacturer will filter out a lot of these kinds of noises, and you will notice a "blacker" background when listening. (Just don't go overboard and spend more than the amp cost...)
   
  Regarding the tubes sounding better after being warmed up - I think that there is universal agreement on this. Some tubes take longer than others, but my guess is that 1/2 to one hour should bring any tube up to maximum performance once they are burnt in. If you change settings, my experience is that some tubes may need about two hours to "settle in."
   
  About tubes getting "tired" I am not sure that there is agreement on this. From what I read some people felt that tubes sounded better after being on for prolonged periods.
   
  All I know is that after trying to analyze the subtle differences between different heptodes and different settings I am getting tired....


----------



## MIKELAP

Quote: 





mordy said:


> Hi Mikelap,
> 
> Re the Siem EH90s, I am one lap ahead of you cause I am nearing the 35 hr mark. In all seriousness, and in the interest of scientific exploration, did you try the 2/7 strap yet? (Did not yet try it myself)


 
  Did not try 2-7 so far i think i mentionned EF95 1-7 was the setting for me but will check that out later forgot to try that one thanks mordy


----------



## Acapella11

Quote: 





mordy said:


> All I know is that after trying to analyze the subtle differences between different heptodes and different settings I am getting tired....


 
   
  +1 Sometimes it is easy to discriminate differences, sometimes it is difficult. Depends on daily form as well. Then, once you have got your impressions sorted you try strapping tubes you haven't strapped yet and it starts over on a slightly easier level.  The next challenge after pinning down differences is prioritization...
   
  After making notes to a quite a few tubes, I already listed the Svetlana 6A2P on the lowest rank. Now, after further burn in and strapping (1/7 or 2/7), I have to reconsider it seems. Another underrated tube for me is the Brimar CV4012 (non-strapped). Specifically after 30 h burn in... The Siemens EH90 Foreign didn't come out as high as I expected but I will tire myself a little more to pin it down...


----------



## MIKELAP

Quote: 





mikelap said:


> Did not try 2-7 so far i think i mentionned EF95 1-7 was the setting for me but will check that out later forgot to try that one thanks mordy


 
   
   
  Quote: 





mordy said:


> Hi Mikelap,
> 
> Re the Siem EH90s, I am one lap ahead of you cause I am nearing the 35 hr mark. In all seriousness, and in the interest of scientific exploration, did you try the 2/7 strap yet? (Did not yet try it myself)


 
  I tried the EF95 2-7 setting not as clean sounding as EF95 1-7 setting but theres more bass warmer sounding in general i like that setting also . not much to hate all in all  . Buena note signor Mordicci


----------



## mordy

Hi Mikelap and A11,
   
  What makes the heptodes so challenging is the enormous amount of time you need for the tubes to burn in and stabilize; then all the different possibilities of no strap or strapping; and THEN, you got to give each setting a couple of hours to show it's true colors.
   
  After all that, you have to decide which setting is best for you. So far I have now way of predicting what it will be. Then, for a tired old mind to try to remember which setting is the favorite one. I can't remember, so I write it down on a post-it note that I affix to the tubes or tube boxes with a rubber band.
  
  Time for a break: (From reading the posts I know that some members like photography.) Up til now I did not know that frogs can beautiful. Lucked out with this picture. (Note the contended philosophical look - must come from enjoying listening to heptodes, or maybe eating bugs.) Do the double click to get a full size pic.


----------



## inphu510n

I do hope you meant "heptoads"


----------



## MIKELAP

Quote: 





mordy said:


> Hi Mikelap and A11,
> 
> What makes the heptodes so challenging is the enormous amount of time you need for the tubes to burn in and stabilize; then all the different possibilities of no strap or strapping; and THEN, you got to give each setting a couple of hours to show it's true colors.
> 
> ...


 
  That same day!


----------



## mordy

Я вижу, что я в хорошей компании.


----------



## TrollDragon

أرى أنني في شركة جيدة.


----------



## gibosi

みんな、今日は 
   
  I received an interesting package today. Recently, I came across a listing for some 6HZ6 tubes, and after a little research, decided to order a few. Found 7 tubes for $8 including shipping, two pairs, Sylvania and GE, and three singles, an extra GE, an RCA and a Mullard. However, the Mullard wasn't in the package...   I have contacted the vendor, but still, cheap. 
   
  I am inclined to describe these as "heptode wannabe pentodes" lol. They were used as FM sound detectors, and thus have two control grids, 1 and 3, plus a screen grid. So theoretically, we can treat these the same way we are currently treating heptodes: unstrapped EF95, EF91/92, and strapped 1-7 and 2-7. Apparently, there are no premium versions available and there is no European number. Since I don't have the Mullard in hand, it is unclear if it was manufactured by Mullard, or just a rebrand. Other than Mullard, I have seen only American brands on eBay. The Sylvanias are burning in unstrapped EF95, and I can tell you that they light up and play. (....a huge sigh of relief.... 
   
  http://www.radiomuseum.org/tubes/tube_6hz6.html
   
  http://www.shinjo.info/frank/sheets/049/6/6HZ6.pdf


----------



## MIKELAP

Quote: 





mordy said:


> Я вижу, что я в хорошей компании.


 
   
Он является одним из с вселенной


----------



## mordy

Hi Gibosi,
   
  Sounds like a fascinating find - can't wait to hear how they sound. In general, with all the new tube types we are trying out, I have not come across great sounding GE tubes with the exception of the Tektronix 6AU6A/4825.
   
  Couldn't be too much demand for 6HZ6; they are selling very cheap on Ebay.
   
  Was playing with the thought of getting a second LD amp to facilitate burn in and to have a back up. Is there a real _audible_ difference between the LD MKIII and LDMKIV/MKIVSE?
   
  Would the cheaper LD1+ amp do the same burn in?
   
  Also, it seems, based on previous posts, that you could purchase an amp from Little Dot directly without tubes and save money.


----------



## gibosi

Quote: 





mordy said:


> Sounds like a fascinating find - can't wait to hear how they sound. In general, with all the new tube types we are trying out, I have not come across great sounding GE tubes with the exception of the Tektronix 6AU6A/4825.
> 
> Couldn't be too much demand for 6HZ6; they are selling very cheap on Ebay.
> 
> ...


 
   
  My gut tells me that the 6HZ6 is something like a cleaned up and tweaked 6CS6. I believe that both were used as FM detectors. However the 6CS6 has these two superfluous grids strapped internally, grid 5 to the cathode and grids 2 and 4 to each other. So in effect, if you take a 6CS6 and eliminate the superfluous grids and then boost the current from .3 amps to .45 amps, the result might be something like a 6HZ6.
   
  And as I have the Sylvania 6CS6, I am looking forward to seeing how the Sylvania 6HZ6 compares. Other than GE and Sylvania, the only other brands I have seen are RCA, Raytheon and Mullard, so the pickings seem to be quite limited. I wonder if Tung-Sol made the 6HZ6, but a quick Google search came up empty.
   
  I have the LD 1+ and yes indeed, of course I use it to burn in all my tubes. And thinking in a similar vein, I am planning to get a LD IVse at some point in time in the future, but will definitely keep my 1+. No sense putting useless hours on expensive power tubes just to burn in drivers when the 1+ will work just as well.


----------



## MIKELAP

Quote: 





mordy said:


> Hi Gibosi,
> 
> Sounds like a fascinating find - can't wait to hear how they sound. In general, with all the new tube types we are trying out, I have not come across great sounding GE tubes with the exception of the Tektronix 6AU6A/4825.
> 
> ...


 
  Here also GE arent impressive i have them in 6av6 and it wasnt my best 6av6 so far i like the Hit Ray an other 6AV6 i have but didnt try yet is the GE JAN 6AV6 will see if they sound better than the regular GE. I would be interested in finding out also if its worth the extra sound wise an MK3 versus MK 4 SE .


----------



## gibosi

Quote: 





gibosi said:


> My gut tells me that the 6HZ6 is something like a cleaned up and tweaked 6CS6. I believe that both were used as FM detectors. However the 6CS6 has these two superfluous grids strapped internally, grid 5 to the cathode and grids 2 and 4 to each other. So in effect, if you take a 6CS6 and eliminate the superfluous grids and then boost the current from .3 amps to .45 amps, the result might be something like a 6HZ6.


 
   
  Just discovered the 6DT6 which appears to be a sister tube to the 6HZ6. It also has two control grids but with .3 amp heaters making it more similar to the 6CS6.
   
http://www.radiomuseum.org/tubes/tube_6dt6.html
   
  http://frank.pocnet.net/sheets/049/6/6DT6A.pdf


----------



## mordy

Hi Gibosi,
   
  In addition to the manufacturers mentioned above re 6HZ6 there is more to play with here:
   
  There are 6DT6A tubes as well + Tung Sol also made them. Also found a European (?) tube EK 6DT6A by Noval as well as a Japanese tube.
   
  These tubes are very cheap in general.
   
  Meanwhile I am trying to hotten up the midrange on my 6H31 Tesla tubes by keeping them on slow simmer for hours. The top and the bottom frequency ranges are super, but I got to find a way to take away the coolness in the midrange. Maybe they are cousins of the hard boiled Voskhods and need more time to blossom. Seems that they are getting a little sweeter around lap 70. I have time while I am waiting for reports on the Detox and Herz tubes......


----------



## gibosi

Quote: 





mordy said:


> There are 6DT6A tubes as well + Tung Sol also made them......
> 
> I have time while I am waiting for reports on the Detox and Herz tubes......


 
   
  Yes, I picked up a pair of Tung-Sol 6DT6 this afternoon. 
   
  "Detox" and "Herz"? lol
   
  Well, after 9 hours of burn in, casually listening to Diana Krall through my Sylvania "Herz", I notice that my toes are tapping.  Her album, "From This Moment On", with that big brass band, sounds great, with a nice, wide sound stage, warm vocals, very good bass and detailed highs.
   
  Again, these are only first impressions, but wanted to reassure folks that these are very nice tubes, especially considering how little they cost.


----------



## MIKELAP

Just picked up some 6DT6 GE japan for $1.25 each and some 6CS6 HALTRON MATSU****A JAPAN $1.75 EACH nice and cheap love it .Thanksguys.     I was sensored  funny i guess they dont like MATSU****A TUBES


----------



## siles1991

Pulled the trigger on the MKIV SE, will be waiting for it to come than I put in my 6N6P-IR and the rest of my tubes!!


----------



## gibosi

Quote: 





mikelap said:


> Just picked up some 6DT6 GE japan for $1.25 each and some 6CS6 HALTRON MATSU****A JAPAN $1.75 EACH nice and cheap love it .Thanksguys.     I was sensored  funny i guess they dont like MATSU****A TUBES


 
   
  Headfi censored you? lol Maybe because it was all in capital letters? 松下 = Matsu****a  (松 = matsu = pine tree and 下 = ****a = below  (Also ****a is pronounced "shta". The "i" is silent.)
   
  edit: they censored me too! lol
  Another way to write using the western alphabet: Matusita.  tu = tsu and si = shi


----------



## gibosi

Quote: 





siles1991 said:


> Pulled the trigger on the MKIV SE, will be waiting for it to come than I put in my 6N6P-IR and the rest of my tubes!!


 
   
  Exciting!  I am hoping to give myself the MKIV SE for a Christmas present. Something very nice to look forward to.


----------



## mordy

Anybody out there who has owned both the Little Dot MKIII and MKIV or MKIVSE and can tell if there is a _sonic_ difference? (Not a bling difference)
   
  David Zhe Zhe called the MKIII the sweet spot of the line.
   
  Regarding censorship, how do they allow the advertisements for the new line of S.... amps?


----------



## siles1991

Quote: 





mordy said:


> Anybody out there who has owned both the Little Dot MKIII and MKIV or MKIVSE and can tell if there is a _sonic_ difference? (Not a bling difference)
> 
> David Zhe Zhe called the MKIII the sweet spot of the line.
> 
> Regarding censorship, how do they allow the advertisements for the new line of S.... amps?


 
  will prolly take awhile for me to give some impressions even if i get my mkiv se i still have to wait for the power tubes since im getting them without stock tubes to cut down the costs jhaha


----------



## MIKELAP

Quote: 





siles1991 said:


> Pulled the trigger on the MKIV SE, will be waiting for it to come than I put in my 6N6P-IR and the rest of my tubes!!


 
  Congrats !


----------



## mordy

Here is a link to an rarely found web site (you probably go on this web site every day) about the differences between the Little Dot MKIII and MKIV.
   
  http://www.head-fi.org/t/413322/little-dot-mk-iii-vs-mk-iv
   
  Reading through the posts Dr. Mordicci's diagnosis is: The MKIII and IV are almost identical twins, but IV wears more expensive clothes. Seriously, the main difference seems to be the tube complement which accounts for the difference/upgrade in sound.
   
  In other words, a MKIII amp with MIV tubes may sound the same. It is true that there are some changes in the internal components, but I have not found any post stating that there is a difference in sound because of this internal upgrade.
   
  This is my humble opinion. As always, I am open to different views.
   
  (BTW, one post says that David will take $10 off the price if you order via his email.)


----------



## gibosi

Quote: 





mordy said:


> Reading through the posts Dr. Mordicci's diagnosis is: The MKIII and IV are almost identical twins, but IV wears more expensive clothes. Seriously, the main difference seems to be the tube complement which accounts for the difference/upgrade in sound.
> 
> In other words, a MKIII amp with MIV tubes may sound the same. It is true that there are some changes in the internal components, but I have not found any post stating that there is a difference in sound because of this internal upgrade.
> 
> This is my humble opinion. As always, I am open to different views.


 
   
  The thing that gets my attention is the MIV has a two-year warranty, whereas the MIII has a one-year warranty. While I suspect you are correct that there would be no detectable differences in sound between these two given the same tube complement, I wonder if the difference in warranty implies something like the difference between a standard tube and a mil-spec tube. Even though they sound the same, the mil-spec tube may have higher-grade materials, better specifications and a longer lifetime....


----------



## siles1991

Quote: 





mordy said:


> Here is a link to an rarely found web site (you probably go on this web site every day) about the differences between the Little Dot MKIII and MKIV.
> 
> http://www.head-fi.org/t/413322/little-dot-mk-iii-vs-mk-iv
> 
> ...


 
  its true haha originally its 409 USD but when i emailed him he quoted me 399USD for the mkiv SE


----------



## mordy

Didn't know that the warranty was for two years on the SE. Remember reading about somebody who had a Little Dot for several (5?) years. It caught fire, and they repaired it free of charge. Otherwise very few repair problems.
   
  Re the tubes: my manual states that the tubes are guaranteed not DOA and then guaranteed for three months.
   
  Just read through a blog on Head Fi about a chap who had trouble with his SE. The blog is not worth reading, except for this gem from the talented designer of the Little Dot amps, Sword Yang. It is very reassuring: 
   
  "Sorry, our products give you an increase of trouble!
   
  Please contact as soon as David, we are still able to provide you with a replacement new machine services, and from the postage paid by us."
   
  (He is definitively much better on designing amps than knowing English! Nice first name as well!)


----------



## siles1991

can someone enlighten me as to why low impedance headphones need higher gain when they have higher volume than the high impedance headphones?
   
  I have a fostex t50rp about 50ohms would that count as low or medium?


----------



## mordy

Here is a link to a forum on headphone impedance. I did not understand it (heptoad fatigue), but maybe it is of value to you.
   
  http://www.head-fi.org/a/headphone-impedance


----------



## mab1376

siles1991 said:


> can someone enlighten me as to why low impedance headphones need higher gain when they have higher volume than the high impedance headphones?
> 
> I have a fostex t50rp about 50ohms would that count as low or medium?




It's because an OTL amp outputs more voltage than amps. Low impedance needs more amps. Since OTL amps are lacking in that department, higher gain supplements that, and gets you higher volume.

My knowledge is pretty basic, someone can chime in to correct me if that's off at all.


----------



## Acapella11

Quote:


siles1991 said:


> can someone enlighten me as to why low impedance headphones need higher gain when they have higher volume than the high impedance headphones?
> 
> I have a fostex t50rp about 50ohms would that count as low or medium?


 
   
  50 is still rather low for the LD MKIII / IV. see also these specs from the LD-page, which are per channel :
   

 Power Output:
 350 mW @ 300/600 ohm
 300 mW @ 120 ohm
 100 mW @ 32 ohm
 Variable Gain: 3,4,5, or 10x
 Recommended Load Impedance: 32 ohm~600 ohm
   
 The LD MKIII / IV really loves phones with 120 ohm and more.
 At 98 dB/mW, the Fostex are reasonably sensitive. From a technical side, these would be more suitable than for example the Hifiman HE-500 (38 ohm, 89 dB/mW). Athough the LD MKIII and IV are surely not the perfect amps for the HE-500, these phones still sound good on it. So, why not your Fostex, which are easier to drive than these?
  
 PS: I generally use 10 x gain with my headphones.
  
 --------------------------------------------------------------------------
  
 *Experimental *LDology:
  
 This sounds a bit weird but here it goes: Have you ever (accidentally maybe) tried to INput your audio signal via the OUT (MKIII / MKIV)? Now, you either scratch your head or laugh...
 I have just done that and was quite positively surprised... Sounds more transparent, cleaner, less relaxed. This bypasses the volume control, which is possibly one of the reasons why it sounds differently and also means that one needs another way to control the volume (DAC, media player). Give it a go.


----------



## Acapella11

Updated the table on p. 77 with 6HZ6 and 6DT6 pentodes. Thanks gibosi.


----------



## mordy

Does it leave the LD on full blast? Most tubes I have will distort on the volume control being turned all the way up in my rig. (My usual setting is 3 o'clock)


----------



## MIKELAP

Quote: 





acapella11 said:


> 50 is still rather low for the LD MKIII / IV. see also these specs from the LD-page, which are per channel :
> 
> 
> Power Output:
> ... 
  Yes its true does sound cleaner for the volume i control it via media player


----------



## gibosi

Just a quick update regarding the Sylvania 6HZ6. After about 25 hours of burn-in, I did a quick A/B with the Sylvania 6CS6. I found them to be very similar to the point that sometimes I wasn't sure which tube I was listening to. This strong similarity reinforces my speculation that the 6HZ6 are simply a pentode version of the 6CS6. So if you are looking for a Sylvania 6CS6, these are often even cheaper. 
   
  I should add that I have yet to try this tube unstrapped EF91/92 or strapped. Will try these configurations later as I now have the GE 6HZ6 burning in. Curious to learn how these will sound....


----------



## Adam2211

Does anywhere know where I can buy these tubes in the UK?

Thanks.


----------



## gibosi

Since it appears that the 6HZ6 and 6DT6 were made only in America and Japan, these will likely be harder to find, and perhaps more expensive in the UK and Europe. Therefore, I recommend that you look for EH90/6CS6 instead. There are some very fine EH90 available from Telefunken, Philips/Mullard and other European manufacturers. I have a pair of Lorenz EH90 with ribbed plates on their way to me from Germany, and I am looking forward to learning how they sound.


----------



## duncan1

Adam2211---1--www.chelmervalve.co.uk---2--www.crickewoodelectronics.com--3--billington export ltd-Sussex--4--colomor electronics  Ltd  London--5--RS components--www. RScomponents.co.uk--there is more if you need it.


----------



## Adam2211

Thanks for the reply.

Can you reccomend me any websites I can get the EH90/6CS6? Would be a big help.


----------



## Adam2211

Thanks Duncan1. Will have a look now.


----------



## MIKELAP

Remember seeing a post that was about buying a Littledot mk4 whitout the tubes is $309.00 was it $50.00 cheaper.And finally its  not worth it to buy MK4SE only difference is the tubes really ,right .the spec. look the same. What do you think.


----------



## mordy

Hi,
   
  Burning in a set of RCA 5915 tubes. Everything sounds good, but I lost my bearings in comparing them to other heptodes. Everything just sounds great, be it Siem EH90, Tesla 6H31, Syl 6CS6, IBM 1680, RCA 6BY6.
   
  I think that I am suffering from Heptoaditis Positiva Confucia (HPC syndrome). The main manifestation of HPC is being addicted to listening to music for long periods of time with a silly grin and accompanied by vigorous toe tapping. Well, in my case it really is heel tapping. (My doctor just told me that I need more exercise - wonder if this qualifies?)
   
  Cheers,


----------



## duncan1

Adam211-The "ultimate" guide to valve/tube suppliers=The webs biggest guide to vintage technology services=www.radiocraft.co.uk   most of the US/UK suppliers one of then MUST have what you want --keep that url.


----------



## TrollDragon

Quote: 





mikelap said:


> Remember seeing a post that was about buying a Littledot mk4 whitout the tubes is $309.00 was it $50.00 cheaper.And finally its  not worth it to buy MK4SE only difference is the tubes really ,right .the spec. look the same. What do you think.


 
  My MK4 came with the SE power tubes, electro harmonix 6H30Pi (gold pins I had one out) instead of the 6H30EB that are supposed to be stock, and the GE 5654 drivers.
   
  If the only difference is a Locking Jack upgrade and the better quality RCA's then I would say no myself. You can pick up the better locking jack from a local supplier for $8 or even get one without the lock. Same for the RCA jacks.
   
  If there were better caps inside and finer tolerance resistors with a stepped volume control I'd say yes.
  From the LDIII thread the solder / wire quality inside these is units is pretty poor, I have no had mine apart so I cant confirm that.


----------



## mab1376

mikelap said:


> Remember seeing a post that was about buying a Littledot mk4 whitout the tubes is $309.00 was it $50.00 cheaper.And finally its  not worth it to buy MK4SE only difference is the tubes really ,right .the spec. look the same. What do you think.




The Little Dot MK IV SE is a special edition version of the Little Dot MK IV which features a Neutrik headphone jack upgrade, premium RCA connectors (American CMC or Van Den Hul RCA), and premium circuit component upgrades in key signal path locations.

http://littledot.net/forum/viewtopic.php?f=9&t=820&sid=66cc1ce2e017fceb54999c6ca8358709

I would love to add a stepped pot if i had the skills to do so. if anyone does this successfully i'd be willing to pay for the upgrade.


----------



## gibosi

After reading about Mordy's experience with his FIVRE-Ferrari heptodes, I came across some FIVRE-Ferrari 6AT6/EBC90 triodes, and thought, why not? 
   
  These look different than any other EBC90 or EBC91 I have seen, so perhaps they will sound different? Like a Ferrari? lol Interestingly, on the inside of the box, the name "Dr Hans Borklin......Munchen.... -8 Sep 1958" is stamped in black ink. (Munchen = Munich, it seems....) I have Googled this gentlemen, but no results.... This suggests these were likely manufactured in the mid-1950s.
   

   

   
  And then, since MIKELAP has been very impressed with his Japanese-made Hit-Ray, I thought it might be interesting to try some Japanese triodes. Found some Japanese-made 6AV6/EBC91 sourced by Multivox for use in their synthesizers in the 1970s. Again, these look entirely different than any other triode I have ever seen, so again, perhaps these will sound different?
   

   
  And finally, a pair of Tung-Sol 6DT6 arrived:
   

   
  GE 6HZ6 update. These tubes have about 12 hours on them, and I think I like them better than the Sylvanias. They have more bass presence than the Sylvanias and the midrange and treble remind me of the 8425. But again, these are very superficial first impressions, only ten minutes or so, of casual listening......


----------



## Oskari

Quote: 





gibosi said:


> "Dr Hans Borklin......Munchen


 
   
  Try Bürklin... and it's München...


----------



## Acapella11

Quote: 





mordy said:


> Does it leave the LD on full blast? Most tubes I have will distort on the volume control being turned all the way up in my rig. (My usual setting is 3 o'clock)


 
   
  It leaves it on almost full blast. Apparently, I find another positive effect that the LD MKIII distorts less. If you find a way to control the volume upfront, you won't have any distortions.
  For Foobar, I have assigned short keys to increase and reduce volume. These days, I use it all the time. Sounds great. =)
   
  Glad you like it Mikelap.


----------



## jaywillin

Quote: 





mordy said:


> Hi,
> 
> Burning in a set of RCA 5915 tubes. Everything sounds good, but I lost my bearings in comparing them to other heptodes. Everything just sounds great, be it Siem EH90, Tesla 6H31, Syl 6CS6, IBM 1680, RCA 6BY6.
> 
> ...


 

 i've got somewhere around 25 hrs on my rca 5915's, they sound great, all the rca's i have are really good, and pretty cheap to boot, a rca 12au7 clear top is my favorite in my indeed g3


----------



## Oskari

Quote: 





mordy said:


> Also found a European (?) tube EK 6DT6A by Noval


 
   
  LOL, noval is a base type.
   
  EK tube boxes look exactly like Ei tube boxes. A secondary brand to Ei perhaps?


----------



## MIKELAP

Im burnin in some Voshkods 6ZHiP-EV that i bought 11/2 years ago but only had 15 hours on them and never really liked them and still dont after 36 hours got a long way to go at least 100 hours got to use them sometimes big bucks i paid for a matched pair didnt know better back then thanks to you guys i know better now. For those interested usually i use the Dac out of my Burson Conductor but decided to give it a break from burnin tubes so now i am using my first  amp you might say which is ASUS ESSENCE STX  soundcard well i miss my Conductor's Dac already i dont recognize the Littledot anymore a lot less detail bass is muddy not tight COULD THIS ARM MY TUBES 
	

	
	
		
		

		
		
	


	


thats where my investment return comes in i guess.I have spare opamps that i got awhile back which should help the Essence but got to remove the card and install them ,someday winter project.


----------



## mab1376

mikelap said:


> Im burnin in some Voshkods 6ZHiP-EV that i bought 11/2 years ago but only had 15 hours on them and never really liked them and still dont after 36 hours got a long way to go at least 100 hours got to use them sometimes big bucks i paid for a matched pair didnt know better back then thanks to you guys i know better now. For those interested usually i use the Dac out of my Burson Conductor but decided to give it a break from burnin tubes so now i am using my first  amp you might say which is ASUS ESSENCE STX  soundcard well i miss my Conductor's Dac already i dont recognize the Littledot anymore a lot less detail bass is muddy not tight COULD THIS ARM MY TUBES
> 
> 
> 
> ...




AD797! they're great in my Auzentech Bravura, although I normally use my PS Audio DLIII.


----------



## inphu510n

Someone email David and ask what these "upgrades in key signal path locations" are other than the mentioned jacks.

Indeed, the soldering work inside my MKII is not great. Some resistors are tightly soldered and others next to them are a few millimetres off the board.


----------



## jjsoviet

Oh dear, one of the tubes I bought as a matched pair (the 6H6P-I power tubes) causes a slight channel imbalance. Contacted Yen Audio about this issue.
   
  Do you think they'll ask me to send the pair back or just the offending tube?


----------



## siles1991

Quote: 





mikelap said:


> Remember seeing a post that was about buying a Littledot mk4 whitout the tubes is $309.00 was it $50.00 cheaper.And finally its  not worth it to buy MK4SE only difference is the tubes really ,right .the spec. look the same. What do you think.


 
  actually an SE version cost 409$ IIRC and im getting it for 305$ without the tubes.


----------



## inphu510n

jjsoviet said:


> Oh dear, one of the tubes I bought as a matched pair (the 6H6P-I power tubes) causes a slight channel imbalance. Contacted Yen Audio about this issue.
> 
> Do you think they'll ask me to send the pair back or just the offending tube?




I wouldn't buy from them in the first place. Overpriced and a sketchy history. As you've unfortunately found, paying their price premium for matched and verified tubes doesn't gain much. Matched doesn't matter with this amp. In fact many of us run tubes that have different internal structures but are still the same tube type from the same manufacturers.

As for whether they'll have you send the tube back I have no idea. Given the price of those tubes I assume they'll ask for the offending tube back.


----------



## MRpilgrim

I'm thinking of buying a little dot 1+. What are the best non EF95, EF91 and EF92 tubes available for cheap? Thanks for the help. Really informative thread by the way.


----------



## siles1991

thinkin of getting a LD mkii as preamp in the future if it can help drive my 50ohm t50rp better? any advice?


----------



## MIKELAP

Quote: 





siles1991 said:


> actually an SE version cost 409$ IIRC and im getting it for 305$ without the tubes.


 
  Thanks for the infos interesting


----------



## gibosi

Quote: 





mrpilgrim said:


> I'm thinking of buying a little dot 1+. What are the best non EF95, EF91 and EF92 tubes available for cheap? Thanks for the help. Really informative thread by the way.


 
   
  Everyone's ears and preferred sound signature are different, so this is always a difficult question to answer.... But off the top of my head, I would recommend the Tung-Sol 6485/6AH6W (halo getters), E91H/6687 (brand doesn't matter as they were all made in the Heerlen, Holland factory), Philips/Mullard/Valvo EH90 and finally Lorenz EBC91.
   
  There are many other very good tubes, but to paraphrase Mordy, tubes are like ice cream. The only way to discover your favorite flavors is to try them all! And I would suggest that you can find some real gems among the heptodes, 6BE6/EK90, 6BY6/5915 and 6CS6/EH90, and the triodes, 6AT6/EBC90 and 6AV6/EBC91.
   
  When you finally get your amp and tubes, please come back and let us know what you think.
   
  Cheers


----------



## MRpilgrim

Thanks for the recommendations. Are these all drop-in replacements?


----------



## MRpilgrim

Im considering either the little dot 1+ or the Aune t1. Could anyone provide any comparisons? Thanks


----------



## gibosi

Quote: 





mrpilgrim said:


> Thanks for the recommendations. Are these all drop-in replacements?


 
   
  See page 77 for information on how to use these tubes.


----------



## gibosi

Quote: 





mrpilgrim said:


> Im considering either the little dot 1+ or the Aune t1. Could anyone provide any comparisons? Thanks


 
   
  I have no experience with the Aune t1....
   
  From the Aune website, it appears that it is a combination DAC/amp, whereas you will need a separate DAC with the 1+. Therefore, in my mind, they are not really comparable products. Further, just considering that both use vacuum tubes, the Aune uses double triode tubes only, whereas, the 1+ can use triodes, pentodes and heptodes, so potential tube rolling is much more limited in the Aune.
   
  Perhaps someone else can comment further....


----------



## jjsoviet

Quote: 





inphu510n said:


> I wouldn't buy from them in the first place. Overpriced and a sketchy history. As you've unfortunately found, paying their price premium for matched and verified tubes doesn't gain much. Matched doesn't matter with this amp. In fact many of us run tubes that have different internal structures but are still the same tube type from the same manufacturers.
> 
> As for whether they'll have you send the tube back I have no idea. Given the price of those tubes I assume they'll ask for the offending tube back.


 
   
  Well lesson learned, so the next time I'll tube roll I'll just scour for cheap deals I guess.
   
  Got the Voshkod 6ZH1P-EV at least. A fellow Head-Fi'er sent me two pairs of them and so far so good.


----------



## mab1376

what was the adapter setting to never have to use EF91 setting for 6AV6?

I want to dive into Triodes finally and i really hate messing with those jumpers.

jump pins 5-6?


----------



## siles1991

I feel that davidzhezhe communication is really slow...I've waited an entire day for a respond than I replied him the same minute I got the response and I have to wait until tomorrow for another respond. Does he only open his email once a day for few minutes? I've already requested twice for him to send me the invoice for the little dot and its been 3 days, he responded to my email but didn't send me the invoice...


----------



## MIKELAP

Quote: 





mab1376 said:


> what was the adapter setting to never have to use EF91 setting for 6AV6?
> 
> I want to dive into Triodes finally and i really hate messing with those jumpers.
> 
> jump pins 5-6?


 
  EF-95 TO EF91- 92 STRAP  6-7 i was told also 5-7 that the setting i was using actually for EF91-92  its on page 77 right below 6hz6,6dt6 tubes


----------



## mab1376

mikelap said:


> EF-95 TO EF91- 92 STRAP  6-7 i was told also 5-7 that the setting i was using actually for EF91-92  its on page 77 right below 6hz6,6dt6 tubes




Any recommendations on specific brands and models?

I was looking into some Tung Sol's of the 6AV6.


----------



## gibosi

Quote: 





mab1376 said:


> Any recommendations on specific brands and models?
> 
> I was looking into some Tung Sol's of the 6AV6.


 
   
  With triodes, it is critical that pins 5 and 7 are tied together in order to get the anode connected properly. As the LD already ties 5 and 6 together on the circuit board, tying 6 and 7 should work fine. However, I tend to be a bit cautious, so I always tie 5 and 7 when using triodes.
   
  I haven't heard the Tung Sol 6AV6, but when Mordy auditioned a bunch of triodes, he reported that the Tung Sol was sub-par. Personally, of the American brands, I prefer the RCA 6AV6. Of the European brands, I briefly reviewed a number of them here on page 134, post 2004.


----------



## mab1376

gibosi said:


> With triodes, it is critical that pins 5 and 7 are tied together in order to get the anode connected properly. As the LD already ties 5 and 6 together on the circuit board, tying 6 and 7 should work fine. However, I tend to be a bit cautious, so I always tie 5 and 7 when using triodes.
> 
> I haven't heard the Tung Sol 6AV6, but when Mordy auditioned a bunch of triodes, he reported that the Tung Sol was sub-par. Personally, of the American brands, I prefer the RCA 6AV6. Of the European brands, I briefly reviewed a number of them here on page 134, post 2004.




Awesome, Thanks!


----------



## gibosi

Oh, and don't forget! Cut off pins 5 and 6! Actually nothing bad seems to happen if you forget to cut them off and just plug them in. (Yes, I have done it!). But obviously, there will be no sound. lol


----------



## hypnos1

Quote: 





adam2211 said:


> Thanks for the reply.
> 
> Can you reccomend me any websites I can get the EH90/6CS6? Would be a big help.


 
   
  Hi Adam2211,
   
  I don't know if Duncan has already given you these sites, but haunebuvintage and tube-fix on European ebay have Valvo EH90s at very reasonable prices - give them a look if you haven't already.
   
  The pair I have just received from the former (he takes offers!) have in fact codes for the factory M.B.L.E., Brussells/Mazda, but it looks like all those basically in the Philips group are performing equally well. But you MUST give them a decent burn-in time - 40+hrs for best performance. When I first popped in this pair I went YUK - nothing like my other EH90s. Should have known better - if I've learned nothing else since joining this marvellous thread, it's that you must never go by first impressions...
  Anyway, having come back after just 16hrs burn - WOW, the difference is amazing. I have never encountered such a massive improvement in such a short time from any other tube I have tried.
   
  So give 'em a go - you can blame me if you're not blown away!!
   
  Cheers, and happy rolling...
   
  Edit : Actually A, to put the record straight I have learned a great deal from these guys. and on many aspects of this intriguing/bewildering/educational/sometimes frustrating but thoroughly addictive pastime. If you haven't already done so, I urge you to take the time and trouble to look back through all these posts (yes, there are a LOT) - I am sure you too will find a great deal of interest...


----------



## gibosi

Quote: 





gibosi said:


> GE 6HZ6 update. These tubes have about 12 hours on them, and I think I like them better than the Sylvanias. They have more bass presence than the Sylvanias and the midrange and treble remind me of the 8425. But again, these are very superficial first impressions, only ten minutes or so, of casual listening......


 
   
  After about 25 hours, I can say these are very nice tubes. Again, they remind me very much of GE 6AU6/8425. I was too lazy to dig my pair out, so I did a quick A/B with the Tung-Sol 6AH6/6485, and they seem to compare very well. I have burned them in using the unstrapped EF95 setting, so don't know how they sound using the other settings. What I can say is that if you would like to have something like the 8425, but don't want to mess with wire jumpers, these are plug and play.... and cheap. 
   
  After I let the amp cool down a bit, will put the Tung-Sol 6DT6 in for burn-in....


----------



## MIKELAP

Quote: 





mab1376 said:


> Any recommendations on specific brands and models?
> 
> I was looking into some Tung Sol's of the 6AV6.


 
  http://stores.ebay.com/E-S-R-C?_trksid=p2047675.l2563   this guy has several brands of 6AV6 thats where i got mine actually  5 tubes for$16.00 +shipping which was $10.00 in my case for 10 tubes  .I find they sound alike but thats me i got Sylvania,GE ,JAN GE, HIT RAY,and RCA had WESTINGHOUSE but i drop one  nice skeleton dought.


----------



## gibosi

Quote: 





mikelap said:


> http://stores.ebay.com/E-S-R-C?_trksid=p2047675.l2563   this guy has several brands of 6AV6 thats where i got mine actually  5 tubes for$16.00 +shipping which was $10.00 in my case for 10 tubes  .I find they sound alike but thats me i got Sylvania,GE ,JAN GE, HIT RAY,and RCA had WESTINGHOUSE but i drop one  nice skeleton dought.


 
   
  I have been waiting so very, very patiently to hear your impressions of the Westinghouse 6AV6....  And now you tell us that you dropped one? lol


----------



## jjsoviet

I'm a little lost. At vacuumtubes.net I couldn't seem to find the 6N6P or 6H6P-I in their list, Can anyone help me with this?


----------



## mab1376

gibosi said:


> I have been waiting so very, very patiently to hear your impressions of the Westinghouse 6AV6....  And now you tell us that you dropped one? lol




http://www.ebay.com/itm/Radio-Vacuum-Tubes-6AV6-WESTINGHOUSE-5-NIB-NOS-/130924569010?pt=Vintage_Electronics_R2&hash=item1e7bb661b2

guess you'll have to order your own 

I just ordered a set of RCA with a set of Sylvania.


----------



## mab1376

jjsoviet said:


> I'm a little lost. At vacuumtubes.net I couldn't seem to find the 6N6P or 6H6P-I in their list, Can anyone help me with this?




http://www.ebay.com/itm/2-x-6N6P-IR-Russian-dual-triode-NOS-/161079607959?pt=LH_DefaultDomain_0&hash=item258117c297


----------



## jjsoviet

Quote: 





mab1376 said:


> http://www.ebay.com/itm/2-x-6N6P-IR-Russian-dual-triode-NOS-/161079607959?pt=LH_DefaultDomain_0&hash=item258117c297


 
   
  Thanks, the price is very fair.
   
  Is it advisable to get these, then return my existing pair of tubes and ask for a refund? I could save a lot since the ones I got were $50.


----------



## MIKELAP

Quote: 





gibosi said:


> I have been waiting so very, very patiently to hear your impressions of the Westinghouse 6AV6....  And now you tell us that you dropped one? lol


 
  To bad i remember you asking me about it was getting to hit but i drop my 6av6 storage box on the floor lucky i only broke 1 tube but it wasnt the wright one. might order again from this guy because he sells singles also.


----------



## gibosi

Quote: 





mikelap said:


> To bad i remember you asking me about it was getting to hit but i drop my 6av6 storage box on the floor lucky i only broke 1 tube but it wasnt the wright one. might order again from this guy because he sells singles also.


 
   
  Quote: 





mab1376 said:


> http://www.ebay.com/itm/Radio-Vacuum-Tubes-6AV6-WESTINGHOUSE-5-NIB-NOS-/130924569010?pt=Vintage_Electronics_R2&hash=item1e7bb661b2
> 
> guess you'll have to order your own


 
   
  I think I can be patient a little longer... lol...  After all, I have yet to even clip the pins on the two pairs of triodes, the FIVRE and the Japanese sourced Multivox, that arrived yesterday....


----------



## inphu510n

jjsoviet said:


> Thanks, the price is very fair.
> 
> Is it advisable to get these, then return my existing pair of tubes and ask for a refund? I could save a lot since the ones I got were $50.




Definitely.
The "R" in "6N6P-IR" means extended life tubes.
You might also consider buying some Electroharmonix/Sovtek 6H30Pi tubes from eBay as well. Both tubes are well regarded as power tubes in this amp. Most people seem to prefer the 6H30Pi while others prefer the 6N6P-IR.

A side note about both tubes. The "i" stands for "impulse". These tubes were originally designed for very strong electrically pulsed circuits and were not rated for very long life. Someone correct me but I believe they were rated for hundreds of hours, not thousands. That said, we are barely using them compared to their ratings.
I know a few here have been using these tubes for a while now so they'll have to chime in about life expectancy for the impulse tubes.


----------



## mab1376

to me the 6H30Pi is much warmer whereas the 6N6P-IR is almost completely transparent, much better for identifying the differences in driver tubes to me.

I also just ordered a pair of Mullard EBC91 10M Master series from vacuumtubes.net


----------



## jjsoviet

Quote: 





inphu510n said:


> Definitely.
> The "R" in "6N6P-IR" means extended life tubes.
> You might also consider buying some Electroharmonix/Sovtek 6H30Pi tubes from eBay as well. Both tubes are well regarded as power tubes in this amp. Most people seem to prefer the 6H30Pi while others prefer the 6N6P-IR.
> 
> ...


 
   
  Well I bought them already lol
   
  Hopefully the IR has the same longevity as the stock tubes that came with these. Lasted me 2 years before one burnt out completely.
   
  Glad that Yen Audio accepts returns for up to 60 days from the purchase date. I'll wait for the 6N6P-IR pair to arrive before issuing a return.


----------



## mab1376

inphu510n said:


> Definitely.
> The "R" in "6N6P-IR" means extended life tubes.
> You might also consider buying some Electroharmonix/Sovtek 6H30Pi tubes from eBay as well. Both tubes are well regarded as power tubes in this amp. Most people seem to prefer the 6H30Pi while others prefer the 6N6P-IR.
> 
> ...




IR means Pulse mode and Low noise

DR (supertube) is long life, IR is only rated at 500 hours but that's in pulse mode where they would electrically take a beating.


 V (Russian: В) - increased reliability and mechanical ruggedness (such as low susceptibility to noise and microphonics).
 R (Russian: Р) - even better than V
 Ye (Russian: Е) - extended service life.
 D (Russian: Д) - exceptionally long service life.
 I (Russian: И) - optimised for "pulsed" (i.e. switching) mode of operation.

http://en.wikipedia.org/wiki/Russian_tube_designations


----------



## inphu510n

Quote: 





jjsoviet said:


> Well I bought them already lol
> 
> Hopefully the IR has the same longevity as the stock tubes that came with these. Lasted me 2 years before one burnt out completely.
> 
> Glad that Yen Audio accepts returns for up to 60 days from the purchase date. I'll wait for the 6N6P-IR pair to arrive before issuing a return.


 
  Heheh I think you've made the right decision. 
  I'm eventually going to purchase a quad of the 6N6P-IR as I'm currently using the 6N6P Gold Grids.


----------



## mordy

Hi jjsoviet,
   
  You mention that one of the stock tubes completely burnt out after two years. How do you know it burnt out? The reason I am asking is that I had the same experience. However, for some reason I saved it.
  A year later on a hunch I took out my little pocket knife and and scraped clean the pins on the bad tube. Pushed it back in, and you wouldn't believe it! It lit up again and works fine. Looks like a little corrosion made it stop working.
   
  About the IR tubes: Although they are rated for 500 hours, and the regular 6N6P tubes for 3000 hours, I agree with the posts that state that this is for severe military working conditions (maybe in a MIG fighter plane).  IMHO they should last much longer in a little quiet preamp....
   
  About extra long life tubes - 7,500 to 10,000 hours: Different manufacturers have different names for these tubes:
   
  Russian tubes: DR
  Amperex: PQ (Premium Quality)
  GE: ***** Five Star
  Mullard: Millenium Series
   
  Remember reading that certain Siemens tubes last very long. One person wrote that they had a Siemens tube that lasted over 100,000 hours!


----------



## MIKELAP

Quote: 





gibosi said:


> I think I can be patient a little longer... lol...  After all, I have yet to even clip the pins on the two pairs of triodes, the FIVRE and the Japanese sourced Multivox, that arrived yesterday....


 
  Its a tuff life not enough time between tube rolling ,going fishing,motorcycling swimming man  im spent lol I wouldnt have time to work ! But i still wish i did sometimes not all the time lol.. Looking for a good excuse to get another Westhinghouse 6AV6 ill think of something.


----------



## jjsoviet

Quote: 





mordy said:


> Hi jjsoviet,
> 
> You mention that one of the stock tubes completely burnt out after two years. How do you know it burnt out? The reason I am asking is that I had the same experience. However, for some reason I saved it.
> A year later on a hunch I took out my little pocket knife and and scraped clean the pins on the bad tube. Pushed it back in, and you wouldn't believe it! It lit up again and works fine. Looks like a little corrosion made it stop working.
> ...


 
   
   
  Actually I was the third owner of the MKIII with the first two having the amp for many months as well. The fact that the original stock tubes lasted this long is astounding, especially that I run the amp for around 8 hours a day. One of the tubes lost signal so there was severe channel imbalance and I had to replace them sadly.


----------



## kvtaco17

Just rolled a opa2107ap with Voshkod 6ZH1P-EV tubes (ran the Voshkods with the stock op amp for the last couple months, probably 100+ hrs on them) and man... its good! Bass is slightly less then with the stock opamp BUT the detail and texture of the bass is much better. Channel separation and sound stage is excellent. Lush, warm, will well extended treble... very tube-y sounding... 

On a scale of 1-11 I give it a... sexual... only rating I can think of... this setup is sexual.... 

Gonna roll my SIEMENS 6AK5W to see is the extra crunch from those tubes translates to sibilance with this opamp

Next experiment is dabbling in the world of heptodes... looking for massive accurate sound stage with the same sonic qualities (maybe a tad more lush... or just touch more or less bass impact then the Voshkods) SYLVANIA 6CS6 maybe?


----------



## gibosi

Quote: 





kvtaco17 said:


> Just rolled a opa2107ap with Voshkod 6ZH1P-EV tubes (ran the Voshkods with the stock op amp for the last couple months, probably 100+ hrs on them) and man... its good! Bass is slightly less then with the stock opamp BUT the detail and texture of the bass is much better. Channel separation and sound stage is excellent. Lush, warm, will well extended treble... very tube-y sounding...
> 
> Next experiment is dabbling in the world of heptodes... looking for massive accurate sound stage with the same sonic qualities (maybe a tad more lush... or just touch more or less bass impact then the Voshkods) SYLVANIA 6CS6 maybe?


 
   
  I have the same op amp in my 1+ and I agree. It was like night and day better than stock MC33078 . And I agree with hypnos1 in recommending Philips/Mullard/Valvo EH90/6CS6. I think it is significantly superior to the Sylvania.
   
  http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/2250#post_9688550


----------



## kvtaco17

gibosi said:


> I have the same op amp in my 1+ and I agree. It was like night and day better than stock MC33078 . And I agree with hypnos1 in recommending Philips/Mullard/Valvo EH90/6CS6. I think it is significantly superior to the Sylvania.
> 
> http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/2250#post_9688550




Which one of them will be closest to my goal?


----------



## gibosi

Quote: 





kvtaco17 said:


> Which one of them will be closest to my goal?


 
   
  Valvo appear to be more common, but they were all made in Philips-owned factories and therefore, sound identical. So ignore the brand and go for the best deal.


----------



## kvtaco17

Sweet, I'll be hunting them down soon!


----------



## gibosi

Quote: 





mikelap said:


> Its a tuff life not enough time between tube rolling ,going fishing,motorcycling swimming man  im spent lol I wouldnt have time to work ! But i still wish i did sometimes not all the time lol.. Looking for a good excuse to get another Westhinghouse 6AV6 ill think of something.


 
   
  And you know, you could bring a electrical generator with you when you go fishing, motorcycling and swimming so you could be rolling those Westinghouse 6AV6 at the same time!


----------



## MIKELAP

Quote: 





gibosi said:


> And you know, you could bring a electrical generator with you when you go fishing, motorcycling and swimming so you could be rolling those Westinghouse 6AV6 at the same time!


 
  lol water and electricity not a good idea to bad because in front of where i fish i have the best white noise generator ,RAPIDS should try and harness that!


----------



## gibosi

Quote: 





mikelap said:


> lol water and electricity not a good idea to bad because in front of where i fish i have the best white noise generator ,RAPIDS should try and harness that!


 
  RAPIDS? Oh, you know what would be even better? You could build a little portable hydroelectric generator to power your Little Dot! So yes, good idea.... harness the rapids... and fishing and tube rolling can go together! lol


----------



## mordy

Quote: 





gibosi said:


> RAPIDS? Oh, you know what would be even better? You could build a little portable hydroelectric generator to power your Little Dot! So yes, good idea.... harness the rapids... and fishing and tube rolling can go together! lol


 
   
  Seriously, since the Little Dot draws around 15W it seems to me that you could hook up a power inverter to the cigarette lighter and drive the amp. Then you could burn in tubes while you drive the 6 hours to the fishing spot.....lol.


----------



## MIKELAP

Quote: 





mordy said:


> Seriously, since the Little Dot draws around 15W it seems to me that you could hook up a power inverter to the cigarette lighter and drive the amp. Then you could burn in tubes while you drive the 6 hours to the fishing spot.....lol.


 
                                                                                                                                                                                                                                                                                                                                                        
   
                                                                                                                                                                                           
                                                                                                                                                                                           
   
  Actually my fishing spot is across the street i am very fortunate to live here  this place is a wildlife reserve rules requires you to wear a floating device and youll understand why heres a few pictures.


----------



## mab1376

Fellow 6n6p-ir owners, whats you date codes? Mine is 89@11
   
  i'm going to buy a new set from 1983 or earlier.


----------



## siles1991

mine shows 02*pentagon*83 so I assume it's 1983 but not sure how to read the 02.


----------



## mab1376

siles1991 said:


> mine shows 02*pentagon*83 so I assume it's 1983 but not sure how to read the 02.




Should mean second week of the year.

I just ordered a pair with 12*pentagon*74, anything from 1983 and earlier supposedly was made in a factory with special materials that were renowned for quality.

One of these days i'll get the 6H30P-DR


----------



## mordy

It is my impression that Russian tubes are date marked with the month/year. 02-74 would be February 1976. I have seen Russian tubes using Roman numerals for the month. April 1976 would be IV/76.
   
  US tubes usually use year/week or some encryption. (Just got a pair of RCA 6CS6 tubes with date code MM. For this you need a chart. In this case it is Nov 1961.)
   
  Strangely enough, I have not been able to find charts that decipher the encrypted date codes on Tung Sol and Sylvania tubes. One reason to keep the manufacturing dates secret was to ensure that people would not worry about buying older tubes since they could not figure out when they were made.
   
  In retrospect this is also strange - we would rather buy older, 60 year old tubes than newer ones from the eighties since we now know that the earlier ones many times were better made.


----------



## Acapella11

Quote: 





mab1376 said:


> Fellow 6n6p-ir owners, whats you date codes? Mine is 89@11
> 
> i'm going to buy a new set from 1983 or earlier.


 
   
  08/74, indicating August 1974.


----------



## Oskari

Quote: 





mordy said:


> Strangely enough, I have not been able to find charts that decipher the encrypted date codes on Tung Sol and Sylvania tubes.


 
   
  Sylvania and Tung-Sol date codes must be some of the best kept secrets on this planet.


----------



## mab1376

Quote: 





acapella11 said:


> 08/74, indicating August 1974.


 
   
  I'm curious to see how my new ones from 1974 compare to my current ones from 1989.


----------



## gibosi

Quote: 





gibosi said:


> After I let the amp cool down a bit, will put the Tung-Sol 6DT6 in for burn-in....


 
   
  After about 28 hours, these Tung Sol 6TD6 are some seriously good tubes. Going by memory, they remind me of the Tung-Sol 6485, with great bass, effortless treble detail and clear vocals that seem to be etched in space. I need to spend some time directly comparing them with the 6485, and further, since these can be strapped 1-7, I feel strongly that I should try them in that configuration too.... Thinking about how that might sound is very intriguing.....


----------



## Oskari

Quote: 





mordy said:


> Also found a European (?) tube EK 6DT6A by Noval


 
   
  Quote: 





oskari said:


> LOL, noval is a base type.
> 
> EK tube boxes look exactly like Ei tube boxes. A secondary brand to Ei perhaps?


 
   
  We discussed this in PM and Mordy thought that I should repeat some of that in this thread, so here it is. This is the tube in question:
   

 http://www.ebay.com.sg/itm/6DT6A-EK-NOS-Tube-Rohre-Lampe-TSF-Valvola-Valvula-/400525363653
   
  I don't think "noval" is a brand here, so EK must be the brand.
   
  The branding is exactly like Ei's. Ei at some point had noval-sized and magnoval-sized boxes with those words printed on them:
   

 http://www.ebay.com.sg/itm/NOS-1-MATCHED-pair-exact-EI-PCC88-7DJ8-TUBES-similar-ECC88-6DJ8-Amplitrex-/251094753127
 http://www.tubes.rs/Tubes/NOS/Audio/OutPentodes/EL509_EL519_6KG6/PL519_40KG6_EI_Yugoslavia.html
   
  Apparently "magnoval" boxes didn't always contain magnoval-based tubes:
   

 http://www.elektroncso.hu/kepek/kt90_ei.jpg
 http://www.jogis-roehrenbude.de/EL34-Story/EL34-Story-Seite5.htm
   
  Why not 7-pin tubes in "noval" boxes then?
   
  Ei (Elektronska industrija) made tubes in Niš, Yugoslavia. These were also sold under other brands, including Siemens:
   

 http://www.tubeampdoctor.com/en/shop_TAD_Tubes_amp_Accessoires_NOS_Rare_amp_Vintage/ECC82_Siemens_NOS_1560
   
  In conclusion, the EK-branded tube was – possibly – made by Ei – or maybe not.


----------



## gibosi

Quote: 





gibosi said:


> After about 28 hours, these Tung Sol 6TD6 are some seriously good tubes. Going by memory, they remind me of the Tung-Sol 6485, with great bass, effortless treble detail and clear vocals that seem to be etched in space. I need to spend some time directly comparing them with the 6485, and further, since these can be strapped 1-7, I feel strongly that I should try them in that configuration too.... Thinking about how that might sound is very intriguing.....


 
   
  Since I think I am the only one who has the 6HZ6 and 6DT6, I wanted to let people know that I have briefly tried the Tung-Sol in all four configurations: unstrapped EF95, unstrapped EF91/92, strapped 1-7 and strapped 2-7. I listened to just one song in each setting as my goal was to verify that each of these settings is valid. And indeed, there is no distortion or anything unusual, and therefore, it will require some time to understand the differences, and then, to decide which is best.
   
  I have decided to start with the strapped 2-7 configuration as the RCA data sheet for the 6DT6 actually suggests two strapping options: (1) connecting grid 1 to the cathode and (2) connecting grid 3 to cathode. While connecting grid 1 to the cathode would require a specially built socket adapter, we can easily connect grid 3 to the cathode as has been routine with 6AU6 and 6AH6. Will report back when I know more.
   
  I sure hope someone else will be getting some of these tubes shortly. It would be great to get a another opinion, or two.


----------



## kvtaco17

Quote: 





kvtaco17 said:


> Just rolled a opa2107ap with Voshkod 6ZH1P-EV tubes (ran the Voshkods with the stock op amp for the last couple months, probably 100+ hrs on them) and man... its good! Bass is slightly less then with the stock opamp BUT the detail and texture of the bass is much better. Channel separation and sound stage is excellent. Lush, warm, will well extended treble... very tube-y sounding...
> 
> On a scale of 1-11 I give it a... sexual... only rating I can think of... this setup is sexual....
> 
> ...


 
   
  nope, not sibilant... just crunchy guitar awesome!


----------



## Acapella11

*Heptodes!*
  
 After a while of living with a few German, Dutch, English and Russian heptodes, here are my impressions.  
 I have ranked them in order to give the review a better structure. A priori, the level of these tubes is rather high, so you could easily live with the lowest of these tubes happily until the end of its tube life. However, you are likely to get more detail out of one of the better tubes. Ranking from 1 being the best to 4 being the worst within this review. Rank 2 is subdivided from (a) being the best down to (d).
 The main differences affect tonality/signature and focus. If the signature as described suits you, you may prefer one lower ranked tube over a higher one. These are my impressions, all is IMHO and I understand that I am not agreeing in every point with former posts but there you go.
  
 I have strapped the tubes as well, but used the unstrapped EF95 mode as the basic mode of operation.
  
 Gear used: Foobar with WASAPI plugin, Audiolab M-DAC (Optimized Spectrum filter), UPOCC RCA cable, LD MKIII run via the regular input mode, Sennheiser HD800
  
 Tubes tested in alphabetical order: Amperex E91H (6687), Brimar CV4012 (KB/AD), Lorenz SEL EK90, Siemens EH90 (foreign), Siemens EK90 (saucer getter), Telefunken EH90 (Ulm, Made in Germany), Telefunken EH900S (Ulm, Made in Germany, gold pins). 
  
 _Starting from the bottom:_
  
 Rank 4
  
 *Svetlana 6A2P *(6A2П) - 6BE6
 October 1967
  
 Firstly, you notice the refined character of the tube and the slightly warm signature. The tube has a refined treble, a bit too laid back for me. The mids are well presented. The strongest side of the tube is the bass. It is well articulated and presented with good weight. You cannot get tired listening to the 6A2P. Listening is quite engaging with good PRaT. However, the tube is not the most transparent one, which also leads to not the best focus. It lacks ambient impression and the stage is not very deep. Overall, an enjoyable tube especially if you are more on the bass head side. 
 1/7- and 2/7-strapping give similar results. The tube sounds more defined, brighter (“touch of triode”), not as bright as the Lorenz SEL EK90 and the treble is not as clean.  
  
 
  
  
 Rank 3
  
 *Siemens EH90* No logo, backside says EH90 in dark brown and “foreign” – 6CS6
 678 indicates June 1978 (?)
  
 Now, this is a difficult one. It sounds so good! Open, very good detail and focus, even toe tapping. The bass is punchy as well but lacks a bit in weight. The mids are a bit too hard for my liking. The signature is more on the cooler side and the tube is inclined towards the treble. Voices are well defined but a bit thin. I can imagine this tube to shine in the right system because it is of very good quality, which is also seen in the excellent instrument separation. Listening to it over a greater length of time makes me feel that I am missing some bass and warmth. Also, it becomes earlier fatiguing than any of the other tubes.
  
 
  
  
 Rank 2 (d)
  
 *Amperex E91H *(6687, Made in Holland) – 6BY6
 Manufacturing code 42G5 – my interpretation: Venolanda SA in Venezuela, 5th week of July 1962
  
 This would be the opposite of fatiguing: very refined sound, round treble. The Amperex delivers lots of detail, good instrument separation and resolution, all on a very wide and deep stage. The sound really is “out of your face”. J For me it sounds a bit too polite though, hence it loses the right kick. Although the bass goes deep and is of good weight, it lacks some punch. Mostly the treble is too laid back here.
 Strapping! OK, this tubes gains with strapping 1/7 sounds more forward and makes it more engaging. More treble! More punch! 1/7 is a wetter version of the 2/7 strap. 2/7 strap makes it sound most forward with most definition. There is great gain in treble and bass punch. It loses some warmth, “organic and natural” part of the sound, which is better preserved in the 1/7-setting. With 1/7-strapping or 2/7, dependent on liking, it sounds better than the unstrapped Telefunken EH900S.
 Recommended strapping: 1/7 > 2/7 > NS
  
 
  
  
 Rank 2 (c)
  
 *Telefunken EH900S* (Made in Germany, Gold pins) – 6BY6
 Ulm, tube 1 from 24/10/1976 (U4206104), tube 2 from 09/11/1974 (U9014104F), tubes are supposedly matched.
  
 Focus! Very good instrument separation. This is another one of the quite refined sounding tubes. This tube has a good tonality and with a slight warmth. It is more engaging than the unstrapped Amperex E91H and comes close to the 1/7-strapped Amperex. The bass weight is quite impressive and it goes deeeep (bass monster), which is lesser pronounced after the tube is fully burnt in. In comparison to the Siemens EK90, the bass is not as “clean” and overall it does not have the same dynamic presentation. For me, the TF EH900S does not sound too forward. I quite enjoy listening for longer spaces of time.
 1/7-strapping defines the bass better, it becomes punchier. The tube sounds opener and brighter, a bit more forward as well but not fatigung. The balance is still good. This sounds better than unstrapped to me, in line with the Amperex impressions. Both are 6BY6 tubes of special quality. 2/7-strapping works even better. More punch, definition and some more “treble energy” making it sound more open, still with good ambient impression, not as forward as with the Amperex E91H. Quite engaging. 
 Recommended strapping: 2/7 > 1/7 > NS
  
 
  
  
 Rank 2 (b)
  
 *Telefunken EH90* (Made in Germany) – 6CS6
 Both tubes U6206922, which I interpret as Ulm, produced on the 26th of September 1979 (or 69?)
  
 Very good separation, focus and transparency. Punchy and impactful bass, engaging, toe tapping, you know the words. It does sound great. Interestingly, the tube combines a few features not commonly coming together with heptodes: Treble is great - extended, but not overly refined as with the EH900S, yet the tube is quite dry for a heptode and relatively forward. More forward than the EH900S. The tonal balance is good. The signature is rather neutral. Fortunately, listening does not get fatiguing easily. I would have wished a bit more spatial information, hence the stage is presented rather flat. In summary, this tube is perfectly enjoyable as long as you don’t request an experience of ambience, which I am missing a bit.
 2/7-strapping yields an intersting effect: The tube sounds wetter compensating out some of the flat stage. A bit of the focus gets lost though. With 1/7, the effect is weaker.
 Depending on preference, I suggest non-strapped or 2/7. I just use non-strapped, which makes this tube sounding special in its own way.
  
  
 
  
  
 Rank 2 (b)
  
 *Lorenz SEL EK90* – 6BE6
 Labelled with 082 and BWB940 with eagle indicating that it was produced for the German Army
  
 Now, this is quite a tube. Very good tonal balance. Sounds “fatter” than the Telefunken EH900S (and Amperex). After powering and listening, you immediately start to tap your toes. It has good dynamics, non-strapped good treble, refined but not rolled off. The bass hits hard with a good weight as well. The signature is slightly warm and very pleasing. The stage is well extended in width and sufficiently in depth with a very good ambient perception. You kind of have to like this tube. Its weakness is on the resolution side. It does not deliver the last word in terms of definition and instrument separation. Here, the Telefunken 2/7-strapped offers more. If your gear does resolve well, then you can extract more detail with better tubes. In summary, it is an engaging all round tube most people would appreciate. 
  
 
  
  
 Rank 2 (a)
  
 *Brimar CV4012* KB/AD (5750, 6BE6W) (= Haltron CV4012 (?)) - 6BE6
 Haltron code: 1AB/3975
  
 These tubes sound basically identical to my ears and look identical from the outside but one tiny bridge under the halo getter.
  
 Now, I might out myself with this ranking but to me these are like the Lorenz with a slightly more refined treble and better resolution / definition. Their imaging is really good, instrument separation goes along very well and they are toe tapping. For me it is like: “yes, please more of this”. Very good PRaT. The bass, very good weight and presence. It is not the most punchy bass every heard, which may be the weaker side of the tube but is not overpowering in my setup. It still is rather well defined. Possibly, this is a good match for the HD800 though, which is not a bass monster but very punchy. I really like the treble as well. It is refined as for most of the tubes, extended, non-fatiguing and with a sufficiently good presence. 
 I can imagine that on a treble weaker system, this treble could become underrepresented. It works for me though. The stage and instrument separation are not as impressive as with the Siemens EK90. 
  
 Non-strapped: In my ears this sounds clean with the blackest background and natural at the same time. My favourite.
 1/7-strapping improves bass puch and treble presence, whilst keeping ambience. It somewhat sounds wetter but it unfortunately also blurs the imaging slightly. If you cannot resolve the difference, then 1/7-strapping may be an option.
 2/7 sounds brighter than NS with better instrument separation, imaging is similar but signature is drier
    
 Recommended strapping: NS > 2/7 > 1/7
  
 
  
  
 Rank 1
  
 *Siemens EK90 *(no logo, saucer getter, black bottom) - 6BE6
 933 with eagle on the side indicates that it was produced for the German Army. 278 on the side indicates Feb 1978 (?)
  
 Here comes my favourite tube. Definition, ambience, wetness and a large stage. The stage is really nice, wide and deep. Black background. Wow. The tube sounds neutral with a warm hint. The bass is punchy and well articulated and goes deep. The treble is refined but not as much as for the special quality 6BY6 tubes. This makes the Siemens sound more dynamic and interesting. The mids are not forward but slightly laid back. The balance throughout the spectrum is good. This tube combines the best of almost all aspects. It is engaging and toe-tapping with great imaging. It sounds also analytical, so you will get all the details from your recording. Unstrapped is here clearly my preferred setting.  
 Shame this tube is not more easily available.


----------



## MIKELAP

Thanks Acapella11 these reviews will be great adding them to  page 77


----------



## mordy

Hi Acapella11,
   
  Congratulations on your extensive review! Very nice work. I must say that I admire your ability to express all the different nuances in how the tubes sound.
   
  From wearing myself in reviewing heptodes I recognize the tremendous brain exercise involved to keep track of all the impressions from the various settings and then remember how the tubes sound, and after wards ranking them.
   
  There is a publication in the US (I am sure there i a British counterpart) called Consumer Reports. They review a lot of stuff, including cars. My personal conclusion is that in rating cars there is a single rating that sort of is all inclusive. They ask owners if they would buy the same car again, and the percentages of people who would buy the same car again correlate well with the highest ranked cars in terms of functionality and reliability (with a few exceptions).
   
  Now, my tongue in cheek proposal is to rate the tubes with a toe tapping index. On a scale of 1 to 5, (5 being the highest) how would you rate the tube?
   
  I'll bet the best tubes are a 5....
   
  Happy tube rolling!


----------



## gibosi

Quote: 





acapella11 said:


> *Heptodes!*
> 
> Tubes tested in alphabetical order: Amperex E91H (6687), Brimar CV4012 (KB/AD), Lorenz SEL EK90, Siemens EH90 (foreign), Siemens EK90 (saucer getter), Telefunken EH90 (Ulm, Made in Germany), Telefunken EH900S (Ulm, Made in Germany, gold pins). 
   
  Great job! I can appreciate how much time and energy it takes to audition 7 different heptodes (strapped and unstrapped), wrap your mind around each of them, and then present your results in a clear and easy to read fashion. And I have never tried to rank them, which makes such a project at least another order of magnitude more difficult!
   
  The biggest surprise for me is the Brimar CV4012. I remember being less than impressed, but that was a couple of months ago, so I think I need to get them out for another listen. And regarding the "foreign" Siemens EH90, can I assume you tried 1-7 and 2-7 and came to the conclusion that unstrapped was the best setting? 
   
  Quote: 





acapella11 said:


> Rank 1
> 
> *Siemens EK90 *(no logo, saucer getter, black bottom) - 6BE6
> 933 with eagle on the side indicates that it was produced for the German Army. 278 on the side indicates Feb 1978 (?)
> ... 
   
  It is obvious to me that only one pair of these tubes exist today, and with a huge bit of luck, you are the guy who has them. I would like to suggest that you consider sending them round robin to each of us so we can hear them too! lol


----------



## mordy

Hi Gibosi,
   
  About the Siemens EK90:
   
   
  http://www.ebay.com/sch/i.html?_from=R40&_sacat=0&_nkw=Siemens+EK90&LH_PrefLoc=2
   
  Above is a link to Ebay but only looks like single tubes from 3 sources.
   
   
  There is a place called Radio Antigua in Spain - won't be surprised if he has some. (He has 6 Mullard sourced Siemens EH90 tubes + 200 more EH90 tubes)
  
  http://www.ebay.es/itm/6BY6-6CS6-EH90-TUBE-NOS-NIB-/140510548791?ssPageName=ADME:X:RTQ:ES:1123


----------



## gibosi

Quote: 





mordy said:


> Hi Gibosi,
> 
> About the Siemens EK90:
> 
> ...


 
   
  Actually, I have two pairs of Siemens EK90. However,as with the Siemens EH90, there are several different incarnations of this tube. A11's tube has saucer getters, a black-glass base and ribbed plates. I have not seen another Siemens pair like his.
   
  The closest I have found is here::
   
http://www.ebay.com/itm/261239403145?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2648
   
  However, the picture is not clear enough to see much detail, and at $15 each, I am unwilling to gamble on them without more information.


----------



## jaywillin

i think my immediate goal, before i get into the strapping, modding tubes, sockets etc, is get a better understanding of which tubes are associated with each jumper setting for tube types, and get an idea of my favorite tube, at each amp setting
  right now, i have my little dot I+ in the ef91/92 setting
  my favorite is the mullard 6am6 ,  treble decay, shimmering , detail, instrument separation , 3D like staging (for lack of a better term)
                                                       bass extension good, i hear individual notes, overall, it just sound more "real"
  other tubes i have at this setting are zaerix 6am6, rca 5915,
   
  its kind of hard to describe what i hear, and what separates each tubes sound, being able to say why i like the sound of one tube compared to another may be a skill that comes with more experience, lets hope !


----------



## gibosi

Quote: 





jaywillin said:


> i think my immediate goal, before i get into the strapping, modding tubes, sockets etc, is get a better understanding of which tubes are associated with each jumper setting for tube types, and get an idea of my favorite tube, at each amp setting
> right now, i have my little dot I+ in the ef91/92 setting
> my favorite is the mullard 6am6 ,  treble decay, shimmering , detail, instrument separation , 3D like staging (for lack of a better term)
> bass extension good, i hear individual notes, overall, it just sound more "real"
> other tubes i have at this setting are zaerix 6am6, rca 5915,


 
   
  IMO the RCA 5915 will probably sound better in the EF95 setting....


----------



## TrollDragon

Quote: 





gibosi said:


> http://www.ebay.com/itm/261239403145?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2648
> 
> However, the picture is not clear enough to see much detail, and at $15 each, I am unwilling to gamble on them without more information.


 
  That's $15 for 10 tubes...


----------



## gibosi

Quote: 





trolldragon said:


> That's $15 for 10 tubes...


 
   
  So it is!! lol...  $15 + $8 (shipping) = $23 or $2.30 each... Hmmmmm... thinking.. thinking.... lol


----------



## Acapella11

Thanks Mikelap, Mordy and Gibosi. Appreciated.
   
  Quote: 





mikelap said:


> Thanks Acapella11 these reviews will be great adding them to  page 77


 
   
  I am not sure this would lead to an overload of page 77 but alternatively, I could go through the thread and include links to posts where members have posted larger numbers of tubes including this one as well. What do you think? You could help me with this if you like. 
   
  Quote: 





> Originally Posted by *mordy* /img/forum/go_quote.gif
> 
> Now, my tongue in cheek proposal is to rate the tubes with a toe tapping index. On a scale of 1 to 5, (5 being the highest) how would you rate the tube?
> 
> ...


 
   
 Toe tapping is a difficult one because, in my understanding, it is a measure for the musicality, kind of the intuitive feel good factor but does not necessarily include detail level and resolution. So, yes for me toe tapping is a good indicator that I like the tube but not the full picture.
  
 For toe tapping, the best tubes also would achieve a 5 (as the best): Siemens EK90, Brimar CV4012, Lorenz SEL EK90, Telefunken EH90. The nice 6BY6s would be a little lower, maybe 4 because they are good for their detail representation rather than engaging. If you strap the EH900S you get more toe tapping out of it. Comparing Svetlana 6A2P and Siemens EH90, the Siemens is stronger in detail than the 6A2P (maybe a rating of 3 then)  and the 6A2P better in toe tapping. Actually, if you ignore detail and stage, the 6A2P is quite a toe tapping tube, almost 4 I'd say.
  
 I have been writing this from my memory as I didn't apply a toe tapping score itself. I can consider this more for future listening sessions. Of course, take this with a grain of salt.
  
  Quote: 





gibosi said:


> The closest I have found is here::
> http://www.ebay.com/itm/261239403145?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2648
> 
> However, the picture is not clear enough to see much detail, and at $15 each, I am unwilling to gamble on them without more information.


 
   
  Great find Gibosi. This does look indeed very similar, as much as one can see.
  As Trolldagon wrote, these are lots of ten per bid. I gambled on one and we could share later.
  
  Quote:  





> It is obvious to me that only one pair of these tubes exist today, and with a huge bit of luck, you are the guy who has them. I would like to suggest that you consider sending them round robin to each of us so we can hear them too! lol


 
   
  Hypnos1 has another pair!
   
  Let's see how the Svetlana 6A2P black bottom tubes are and consider options after that.


----------



## gibosi

Quote: 





acapella11 said:


> Great find Gibosi. This does look indeed very similar, as much as one can see.
> As Trolldagon wrote, these are lots of ten per bid. I gambled on one and we could share later.
> 
> Let's see how the Svetlana 6A2P black bottom tubes are and consider options after that.
 
   
  Thank you for taking a chance on these! BRAVO!! And if they do turn out to be the same, this would be huge! 
   
  I have been watching them for quite some time, but since I was so focused on studying the picture, I missed the fact that the price was for ten of them. lol On the other hand, even if I had ordered them, I still would have no way of knowing if they were the same as yours. So this is perfect as you will be able to tell in short order if they are the same. I've got my fingers crossed!


----------



## TrollDragon

If they are good "Toe Tappers" and a couple of you pick the lots up, sell a few up my way as I really can't see me using 10 of them...


----------



## hypnos1

Quote: 





acapella11 said:


> Thanks Mikelap, Mordy and Gibosi. Appreciated.
> 
> 
> I am not sure this would lead to an overload of page 77 but alternatively, I could go through the thread and include links to posts where members have posted larger numbers of tubes including this one as well. What do you think? You could help me with this if you like.
> ... 
   
  Hi A11,
   
  Yes indeed, you deserve a medal (or 2!) for your mammoth effort. Well done.
   
  There is just one thing that really surprises me - Siemens EK90 (yes, like yours...) vs EH90. With my system (and my ears) the result seems totally opposite to yours!! And especially now I have given the EH90s the 1-7 treatment (thanks to prompting by gibosi!). In particular your experience with bass perplexes me - I believe AFB also was amazed by the bass response...
   
  Don't know if it's perhaps down to the tube source? There seem to be so many in the Siemens stable. Mine are all Mullard/Philips group (including Valvo) - with smooth plates. The Valvos (actually M.B.L.E. Brussells/Mazda) do however have a small bridging plate at the top, unlike the others. All give me more in all departments than the EK90s, especially those with the Mullard Blackburn code B5I4 and strangely 'made in Germany' on them! (slightly more transparent than the Valvos).
   
  So you have me in hi-perplexed mode, mon ami. Especially because my findings seemed to be vindicated by my (pleasant) surprise when I had to listen right through a particular Clannad number which I previously had no time for. Will obviously have to do some really serious re-comparing!
   
  The journey continues...


----------



## siles1991

Quote: 





gibosi said:


> Thank you for taking a chance on these! BRAVO!! And if they do turn out to be the same, this would be huge!
> 
> I have been watching them for quite some time, but since I was so focused on studying the picture, I missed the fact that the price was for ten of them. lol On the other hand, even if I had ordered them, I still would have no way of knowing if they were the same as yours. So this is perfect as you will be able to tell in short order if they are the same. I've got my fingers crossed!


 
  if they are one of the same mind selling me a pair?


----------



## jaywillin

Quote: 





gibosi said:


> IMO the RCA 5915 will probably sound better in the EF95 setting....


 

 will make a note of that, thanks !


----------



## mordy

Hi All,
   
  For all you history buffs out there, I found a fascinating account of the convoluted history of the Philips company from the perspective of tube manufacturing. (Too many facts for me to retain in one reading, but two things stand out: Sylvania' oak leaf logo came from an acquisition of the Hygrade Co, and 1980's Philips ECG tubes were made by Sylvania.
   
   
*What's the deal with Amperex, Sylvania, and Philips? What is "Philips ECG", and why is it different than European Philips or Philips Miniwatt?*
  Man, the answer makes trying to sort out the facts of the Mexican Revolution seem easy.
   
  Here's the history on this. Royal Philips, NV, is a Dutch based company (royal, because they've got a charter from the Dutch monarchy), began as a light bulb manufacturer in 1891 and later expanded their range to many types of electronic components (tubes in the 1920's), and electrical & electronic consumer products. Being shrewd and profit minded as the Dutch are prone to be, and bearing in mind many of the tricky legalities involved in exports in pre-Common Market Europe, Philips began acquiring tube manufacturers in other countries, and licensing designs to other tube manufacturers in localities where they could not buy into the market (such as Japan). They also licensed tube designs from US tube manufacturers such as Western Electric (yes, they made some WE numbers such as 310A).
   
  Some of the brands owned by Philips were Mullard, Valvo, Mazda, Adzam, Miniwatt and Dario.
   
  Amperex was originally a small industrial tube manufacturer in Long Island, NY. After WW2, Philips acquired this company (which continued to make certain tube types in the USA, including the ubiquitous 6922), and began using them to distribute European made Philips products (including but not limited to tubes, there were also Amperex semiconductors, resistors & whatnot) in the USA.The products sold could've been from the Netherlands (made by Philips themselves), or any of their subsidiary companies, across Europe or elsewhere. So strictly speaking, there's very few tubes that were actually made by Amperex, and these tubes would've been sold in Europe under their home brand names. So what you've got in a 1960's Amperex tube would've really been a Philips Miniwatt if it was marked "Made in Holland", a Valvo if it was made in Germany, and so forth...usually. Philips, like other tube manufacturers, was not adverse to buying in tubes from other tube manufacturers to fill out their distributor product line, so simply being labelled Amperex doesn't mean it was made by Philips or a Philips company.
   
  Sylvania was yet another light bulb manufacturer that got into the tube (and later, radio) business. In the 1930's they merged with the Hygrade company and adopted Hygrade's logo. Some military tubes made by Sylvania are marked "Hygrade Sylvania Corp.". In 1959, Sylvania merged with AT&T/Bell Telephone's much smaller but feisty rival, General Telephone Corp, to create General Telephone and Electronics (GTE), I would guess because General Telephone was jealous of the big profits AT&T's Western Electric subsidiary was making in manufacturing & licensing electronic components. So, GTE made telephones [Automatic Electric], electronic components [Sylvania] and ran a telephone system [General Telephone], just like AT&T, sort of, albeit on a much smaller scale. Consider that in the 1960's, AT&T was the world's largest and most profitable company, so aping AT&T made plenty of sense at the time.
   
  In the 1970's GTE reorganized Sylvania into several "groups", the Lighting Group, the Consumer Electronics Group, and the Electronic Components Group. Thus , Sylvania tubes began carrying the "Sylvania ECG" logo, ECG meaning Electronic Components Group. Sylvania was a large supplier of all types of replacement electronic components to electronic distributors at the time, including both tubes and transistors.Its successor, Philips ECG, still is.
  About 1980, some weird transactions took place. Philips got tired of making tubes in Europe, and its Amperex subsidiary wasn't doing too well, so they sold off their English & Dutch tube making assets and the rights to the Mullard & Amperex brand names to Richardson Electronics of La Fox, IL, and withdrew the license to use the Mullard brand name from International Electronic Components of Long Island, NY.But at almost the same time, in a shrewd move that greatly strengthened their position in electronic components and consumer electronics in the USA, they bought the Electronic Components and Consumer Electronics divisions of Sylvania from GTE, which included the Sylvania tube plant. This plant continued to make the same tubes, but under the new Philips ECG brand name, which doesn't have anything to do with European Philips Miniwatt, or Amperex tubes.Production was discontinued ca. 1987, but Philips continued (and as far as we know still does) to market tubes under the Philips ECG brand name, by outsourcing tubes from current production manufacturers, when stocks of US made tubes were exhausted.
   
  The Amperex & Mullard brand names (as well as TungSol) as noted above are trademarks owned by Richardson Electronics, Ltd, which continues to market tubes under the Amperex brand name. The larger & more expensive industrial Amperex tubes are indeed made by Richardson, but the smaller tubes (like what you'd use in a usual hifi or guitar amp) are not, they're either US military surplus (usually, Philips ECG) or current production sources such as Svetlana or Tesla-JJ. New Sensor Corp is marketing new reproductions of Mullard & TungSol tubes, we don't know whether they own the names or merely licensing their use from Richardson.
   
  GTE retained ownership of the Sylvania Lighting Group, which it sold to Osram GMBH in 1993. Sylvania Osram is now a division of Siemens.
  A brief history of Philips can be found on this page, and a history of Sylvania can be found on this page.


----------



## Acapella11

Quote: 





hypnos1 said:


> Hi A11,
> 
> Yes indeed, you deserve a medal (or 2!) for your mammoth effort. Well done.
> 
> ...


 
   
  Thanks Hypnos. I believe yours were not the "foreign" type of tubes without SH-logo? It sounds logic to me that different types of manufacturing of the Siemens EH90 would make them sound differently. Unfortunatley, in my slightly brightish system my "foreign" EH90 tubes are not a good match.


----------



## mordy

In post 2298 Oskari introduces us to a Yugoslavian tube manufacturer Ei (Elektronska industrija). Depending on the source, they used Philips and/or Telefunken manufactured equipment, and produced high grade tubes. (Most likely they started out with Philips machinery, and later switched or added Telefunken machines.)
   
  Since they made tubes for Siemens and Telefunken, there is a distinct possibility that the Siemens mystery tubes were manufactured by them.
   
  Today the country is named Serbia. The Ei factory survived the extended war intact, but production was shut down a long time ago. The equipment was supposed to be sold to Western Electric but is still sitting there. Perhaps when the political situation becomes more stable, the tube manufacturing equipment will be sold.
   
  There is a three part video on Youtube showing tube production in the Ei factories. The films are not as instructive as the ones by Mullard, but they certainly show the use of sophisticated manufacturing equipment. Here is a link to one of the three parts:
   
  http://www.youtube.com/watch?v=fxXrfU36aY8


----------



## Advil

Looking for some good all-around tubes for my Little Dot II++. I just found it in the garage and it's been sitting there with some Mullard 161's for years and idk if they'll work. More info here  http://www.head-fi.org/t/676512/getting-back-into-head-fi-found-my-old-tube-amp-quick-question


----------



## MIKELAP

Quote: 





gibosi said:


> Great job! I can appreciate how much time and energy it takes to audition 7 different heptodes (strapped and unstrapped), wrap your mind around each of them, and then present your results in a clear and easy to read fashion. And I have never tried to rank them, which makes such a project at least another order of magnitude more difficult!
> 
> The biggest surprise for me is the Brimar CV4012. I remember being less than impressed, but that was a couple of months ago, so I think I need to get them out for another listen. And regarding the "foreign" Siemens EH90, can I assume you tried 1-7 and 2-7 and came to the conclusion that unstrapped was the best setting?
> 
> ...


 
  Globetrotting tubes, a new trend maybe !


----------



## MIKELAP

Quote: 





advil said:


> Looking for some good all-around tubes for my Little Dot II++. I just found it in the garage and it's been sitting there with some Mullard 161's for years and idk if they'll work. More info here  http://www.head-fi.org/t/676512/getting-back-into-head-fi-found-my-old-tube-amp-quick-question


 
  Go to page 77 of this thread  on this page youll find good tubes for cheap happy reading .


----------



## jaywillin

thanks for the tube history info mordy,
  in the beginning when i had tube amps for my speakers, i just popped some "what evers" in , and let it play, that was fine
  as i've gotten back into tubes with the headphone thing, it kinda started like that, but now i find i'm wanting to more of the particulars
  for the tubes i'm using, and i'm starting from pretty much scratch, diode, triode, heptode, what constitutes the same tube 408=6028, etc
  some of the stuff on page 77 i get confused with, so, going to try to go slower, more methodical, start at the beginning, and move forward, novel idea i know lol


----------



## mordy

Hi jaywillin,
   
  Page 77 is a work in progress that outlines different tubes that can be used with the Little Dot amps other than the types originally recommended for it.
   
  Some tubes are plug and play (P&P) and don't need any straps; others can be used only with straps, and yet others can be used in several different ways. Some tubes can only be used if you cut off certain pins. All this information is in the chart, as well as general recommendations for getting the best results with specific tube families.
   
  Instead of going through the list methodically, my humble recommendation is to start with the heptodes. All of them can be used in the P&P mode. They are inexpensive and plentiful, and substantially better sounding than the 6AK5/5654 tubes etc.
   
  Try to find an inexpensive pair (these can be found for less than $3 each, incl shipping), just plug them in, and enjoy!


----------



## gibosi

Quote: 





acapella11 said:


> Unfortunatley, in my slightly brightish system my "foreign" EH90 tubes are not a good match.


 
   
  You have a "slightly brightish system"... What makes your system "brightish"? Is it that your HD800 are brighter than, for example, HD650? Or is it something else?


----------



## jaywillin

regarding heptodes, the rca 5915 i have its a heptode , and the optimal setting for heptodes is the ef95 setting : (4): Offers a great standard setting , but they can can be used in the ef91 setting, and not sound as good , i believe i was misreading the graph, as to which setting was better
   
  the mullard 6am6  that i'm liking so much right now in the ef91 setting, it not a heptode ? for some reason, i was thinking it was, which was contributing to some of my confusion,
   
  now to get maybe another pair or two of the heptodes for comparing


----------



## gibosi

Quote: 





jaywillin said:


> regarding heptodes, the rca 5915 i have its a heptode , and the optimal setting for heptodes is the ef95 setting : (4): Offers a great standard setting , but they can can be used in the ef91 setting, and not sound as good , i believe i was misreading the graph, as to which setting was better


 
   
  Actually, no.... The graph does not provide any information as to which setting is best. What it tells you is that the tubes can safely be used in the settings listed. In the end, the optimal setting for heptodes can be found only through trying them all. And in fact, some members of this forum disagree on the best setting for some of these heptodes. Again, everyone has different ears and different gear....
   
  That said, even though heptodes will work perfectly fine in the EF91 setting, I don't think I have ever read a review in which someone said that the EF91 setting was optimal.  And so for any heptode, I think I can safely say that the EF95 setting is 99.9% more likely to be better than the EF91 setting.


----------



## jaywillin

Quote: 





gibosi said:


> Actually, no.... The graph does not provide any information as to which setting is best. What it tells you is that the tubes can safely be used in the settings listed. In the end, the optimal setting for heptodes can be found only through trying them all. And in fact, some members of this forum disagree on the best setting for some of these heptodes. Again, everyone has different ears and different gear....
> 
> That said, even though heptodes will work perfectly fine in the EF91 setting, I don't think I have ever read a review in which someone said that the EF91 setting was optimal.  And so for any heptode, I think I safely say that the EF95 setting is 99.9% more likely to be better than the EF91 setting.


 

 ohhhh, ok, the picture's getting a little clearer, i think tomorrow, i'll switch to the ef95 setting, and get the rca 5915 back in there, i've spent the last few days with the mullard,6am6, really liked it, i'll see how the 5915(with the ef95 setting) compares to it


----------



## loose

Right guys I have read a post by mikelap on another thread here explaining tube changing and jumper settings.
   
  However I am all new to this and after reading the post I am still clueless on how to go about changing my stock tubes to something better like Mullard 8161 or similar.
   
  So I have some questions:
   
  1)  How do I change the driver tubes?  Is it just a matter of pulling the tube out from the top of the amp without needing to open the amp?
2)  From what I have read there are two tube familes; EF92 and EF95?  Is the amp already on the EF95 jumper setting?  So if I bought tubes from the EF92 family then I would need to change the jumper settings?  (my LD mkiii is version 4 so has jumpers I believe?)
  3)  Can someone please post a pic of the jumpers that I need to change if required (I don't know what they are and what they look like)  Also how do I go about accessing and changing these jumpers, does it require the amp to be fully opened up or can you access them and change without opening?
  4)  Is there an easier way to change the jumper settings where I can get some sort of adapter to attach the tube on e.g. EF95 to EF92 adapter, how does this work?
   
  Sorry for all of the questions but I am clueless when it comes to this tube changing.


----------



## hypnos1

Quote: 





acapella11 said:


> Thanks Hypnos. I believe yours were not the "foreign" type of tubes without SH-logo? It sounds logic to me that different types of manufacturing of the Siemens EH90 would make them sound differently. Unfortunatley, in my slightly brightish system my "foreign" EH90 tubes are not a good match.


 
  Hi again A11.
   
  It looks to me like the culprit is probably the different tube. Yes, mine appear quite different to the ribbed "foreign" type. Actually, I am somewhat intrigued/slightly unsettled by my findings between the 3 Philips group tubes. I mentioned previously the Valvos being less transparent than the Mullards/Blackburn. Now that I have put the B5I4s (with 'made in Germany on') back in (1-7 strap), I am noticing a superiority over BOTH the others. The Valvos I can understand, because there is that obvious difference with the small bridging plate near the top. But the other Mullards are B6G3 - same factory, just a year later,the only discernible difference being as I showed with photo a while back...
  Ergo, it looks like luck of the draw plays a rather larger part in overall result than perhaps we previously thought?
   
  And perhaps your tubes and headphones DON'T like each other, just to compound the issue!. Your HD800s should certainly have greater detail/resolution than my 650s, but perhaps the gap is narrowed a bit by my pure silver cable replacement (hopefully!). And , of course, my own comparisons have been with the same 650s and similar burn-in.
   
  So once again the cry has to be "Suck it and see!".
   
  Good luck, all you rollers out there!....


----------



## jaywillin

while i've got the little dot I+ opened up, to change to ef95 setting, got the g3 with the sylvania 12au7 gold lettering, pins pulling some head time, cleansing the pallet so to speak


----------



## MIKELAP

Quote: 





loose said:


> Right guys I have read a post by mikelap on another thread here explaining tube changing and jumper settings.
> 
> However I am all new to this and after reading the post I am still clueless on how to go about changing my stock tubes to something better like Mullard 8161 or similar.
> 
> ...


 
  1= power off amp pull on tube 2= here are 2 pictures on one picture you only see 3pins there is no  jumper on.Arrow ON RIGHT SIDE points to EF95 SIDE of board  Arrow on left side is EF92 SETTING on picture at bottom jumper is on EF92 SETTING there is a left channel jumper to set  and a right channel jumper to set (picture of jumper)3= to access jumpers POWER OFF AMP look under the amp theres 2 peep holes jumpers are there (picture) 4= like i said in other post seller is in China  contact him to see if they are still available heres picture . it is written on socket what you need to order.  regarding socket installation,jumpers have to be on EF92 setting and you put EF95 TUBES IN THE SOCKET ADAPTOR http://stores.ebay.com/happydiy998     Hope this helps  .


----------



## Acapella11

Quote: 





gibosi said:


> You have a "slightly brightish system"... What makes your system "brightish"? Is it that your HD800 are brighter than, for example, HD650? Or is it something else?


 
 In brief, it is due to headphones and DAC-setting.
 Yes, the HD800 has a very different signature form the HD650. The HD650 is rather dark and relaxed, the HD800 brighter and "agile". The HD650 has a nicely deep but not too wide stage, The HD800 produces an immensely deep and wide room and is amazing in terms of imaging and detail. It is like an audio scalpel. If the system is not matched, you really spoil the fun. If you match the components, you go "wow !". The M-DAC also contributes a bit with its filter setting. In contrast to most DACs, the M-DAC offers the option to choose how the digital filter is optimized. In my ear, the "optimal spectrum" sounds best because it is a very punchy, detailed and true setting but also the brightest of the filters. So, the system becomes slightly brightish and this is also why a tube amp or dark SS-amp fits well. Heptodes suit actually really well, as you can imagine. I kind of like to hear "the truth", lol, and that's why the transparent and revealing character of the setup is great and good imaging is a treat. =)
   
  Quote: 





hypnos1 said:


> Hi again A11.
> 
> It looks to me like the culprit is probably the different tube. Yes, mine appear quite different to the ribbed "foreign" type...
> 
> ...


 
   
 It is likely that the tubes sound somewhat different. Unfortunately, I didn't find a matching pair of your tubes. I bought one, only to find that the tubes were produced at different sites (Blackburn and Mazda Brussels). Then, yes, as pointed out above, HD650 and HD800 do sound very different. Probably, the HD650 much easier "buffers" a treble biased tube, so does my HE-500. Also the HD650 is more bass biased as the treble is relatively relaxed. A pure silver cable, I can imagine, would compensate for some of the HD650 darkness and open it up. Should be a good match. Overall, I actually enjoyed the HD650 after I got used to the signature and appreciated its quality and how well it scales with better gear. Lots of headroom. It just wasn't my favourite signature.


----------



## loose

Quote: 





mikelap said:


> 1= power off amp pull on tube 2= here are 2 pictures on one picture you only see 3pins there is no  jumper on.Arrow ON RIGHT SIDE points to EF95 SIDE of board  Arrow on left side is EF92 SETTING on picture at bottom jumper is on EF92 SETTING there is a left channel jumper to set  and a right channel jumper to set (picture of jumper)3= to access jumpers POWER OFF AMP look under the amp theres 2 peep holes jumpers are there (picture) 4= like i said in other post seller is in China  contact him to see if they are still available heres picture . it is written on socket what you need to order.  regarding socket installation,jumpers have to be on EF92 setting and you put EF95 TUBES IN THE SOCKET ADAPTOR http://stores.ebay.com/happydiy998     Hope this helps  .


 
   
   
  Thanks for that MIKELAP.
   
  I think I can see the jumpers now, are there two of them one on the left peep hole and one on the right peep hole?
   
  I can see that both jumpers are on in my amp and they are on the two left pins on each side.  So does that mean that my amp is currently on the EF92 setting?  So if I was to get the Mullard 8161 tubes, then in order to change the jumper to EF95 would I just need to take both the black jumpers off on both sides (one in the left sided peep hole and one in the right sided peep hole). 
   
  Or would I need to take the jumpers off the pins and replace them again on the pins but in a different position?
   
  I am confused now as the manual says that " if the switches are not "bridged"  (no jumper), the following tubes (and equivalents) may be used"
   
  WE301A/B, GE5654, M8100, CV4010, EF95, 6J! etc.
   
  What does bridged mean?
   
  Does this mean I just need to take the two jumpers off and leave the pins as they are on both sides if I wanted to use the Mullard 8161 (EF95 tubes)?


----------



## MIKELAP

Quote: 





loose said:


> Thanks for that MIKELAP.
> 
> I think I can see the jumpers now, are there two of them one on the left peep hole and one on the right peep hole?
> 
> ...


 
  yes one jumper in left peep hole one jumper in right peephole ,and yes your amp would be on the EF92 setting . Mullard 8161 are EF91-92 tubes. to put jumpers on the EF95 SETTING  you use a pair of tweezers and pull on the jumpers and reinstall them on the 2 pins on the right side where it says EF95 -5654 . regarding switches that are not bridged i dont understand that either . bridged means linked ,might ask that question to someone else . what i described above works dought thats what i do.


----------



## jaywillin

changed the jumpers on my LD I+, listening again to the rca 5915, indeed much better in the ef95 setting
  though i don't know if i could say that i liked them better than the mullard 6am6


----------



## loose

mikelap said:


> Quote:
> 
> 
> 
> ...




Cheers. 

So if the mallard 8161 is a ef92 tube that means I don't need to do anything right now as my amp is already on the ef92 setting right?

As a side note what happens if you put tubes in and the wrong jumper is set, does any damage occur to the amp or the tubes?


----------



## MIKELAP

Quote: 





loose said:


> Cheers.
> 
> So if the mallard 8161 is a ef92 tube that means I don't need to do anything right now as my amp is already on the ef92 setting right?
> 
> As a side note what happens if you put tubes in and the wrong jumper is set, does any damage occur to the amp or the tubes?


 
  right if it is as you described yes,and  you will know right away somethings wrong if the setting is not ok either you wont ear anything or you will ear distotion of somekind just shut it off right away and it should be ok it happen to me several times and my amp is still working fine


----------



## MIKELAP

Quote: 





mikelap said:


> if it is as you described yes just put your tubes in ,and  you will know right away if somethings wrong if the setting is not ok either you wont ear anything or you will ear distotion of somekind just shut it off right away and it should be ok it happen to me several times and my amp is still working fine


----------



## TrollDragon

Bridged means two pins are shorted with a jumper.


----------



## loose

I am really confused now.
   
  I have take out one of the tubes and it says Sylvania 6ak5W 5654/6096.  
   
  Isn't this stock tube part of the EF95 family?  So I am wrong in thinking my amp is currently set to EF92 jumper setting as then these stock tubes wouldn't be working?
   
  When you are looking at the jumpers from the peep holes which way do you hold the amp to look inside (with the front facia of the amp with volume knob at the top or at the bottom?).
   
  I am holding it and looking at the peep holes with the volume knob of the amp at the top and this way I can see that the jumpers are covering the two pins on the right.
   
  Is this the right way of looking at it?


----------



## gibosi

Quote: 





acapella11 said:


> In brief, it is due to headphones and DAC-setting.
> Yes, the HD800 has a very different signature form the HD650. The HD650 is rather dark and relaxed, the HD800 brighter and "agile". The HD650 has a nicely deep but not too wide stage, The HD800 produces an immensely deep and wide room and is amazing in terms of imaging and detail. It is like an audio scalpel. If the system is not matched, you really spoil the fun. If you match the components, you go "wow !". The M-DAC also contributes a bit with its filter setting. In contrast to most DACs, the M-DAC offers the option to choose how the digital filter is optimized. In my ear, the "optimal spectrum" sounds best because it is a very punchy, detailed and true setting but also the brightest of the filters. So, the system becomes slightly brightish and this is also why a tube amp or dark SS-amp fits well. Heptodes suit actually really well, as you can imagine. I kind of like to hear "the truth", lol, and that's why the transparent and revealing character of the setup is great and good imaging is a treat. =) 
   
  Thanks! Your explanation helps me to better understand your impressions in light of my own system. My HE300 is darker than your HD800, as it is considered to be similar to the HD650, and I am currently using an OPA2107 op amp, which is also considered to be a bit dark. So it would seem to follow that there is a good chance tubes you find to be a bit too treble-inclined, such as the "foreign" Siemens, might sound quite good in my system.
   
  However, I am preparing to roll several different op amps (LME49720HA, LME49990, and LT1028 in case anyone is interested) that are considered more neutral than the OPA217. It will be interesting to see how this changes my opinion of the 4 tubes we have in common.


----------



## TrollDragon

If you look at the board there should be litte white letters (Silk Screen) that say which side is which. You move your jumper to the two pins on the side that you want. 

Sent from my HTC Desire HD A9191 using Tapatalk 2


----------



## loose

This is the way I am looking at the jumpers.

As you can see the jumpers are covering the two pins on the right from this way (the volume knob can be seen at the top).

Am I looking at the jumpers the right way?

Am I right in stating that the jumpers are on the EF95 setting?

Are the stock sylvania 5654 tubes ef95?

Is this the same tubes for all versions of the mkiii amp?


----------



## mab1376

So my DAC died... Anyone every had a problem with a DAC having a horrible hum? the company that modded it said: "Sometimes, the transformer becomes loose, and needs to be re-oriented, to lower the hum." Has anyone every heard of this?
   
  PS Audio directly luckily said its still within warranty even though i bought it second hand through eBay. sadly I'll be mailing it out this week for repair...


----------



## gibosi

Quote: 





mab1376 said:


> So my DAC died... Anyone every had a problem with a DAC having a horrible hum? the company that modded it said: "Sometimes, the transformer becomes loose, and needs to be re-oriented, to lower the hum." Has anyone every heard of this?
> 
> PS Audio directly luckily said its still within warranty even though i bought it second hand through eBay. sadly I'll be mailing it out this week for repair...


 
   
  That's a bummer!   Do you have a decent back-up?


----------



## mordy

Hi Loose,
   
  Use this link to go to the Little Dot website to download the MKIII manual.
   
Little Dot MK III Reference Guide (Dropbox) 
   
  On p.10 it explains about different tube families and the jumper settings. (The continuation of this table is on p.77 on this forum.)
   
   
  Below is the link to the MKIII website
  http://www.littledot.net/forum/viewtopic.php?f=9&t=815&sid=1c26d31ad57ee9ec7ea6f4499a3cb958


----------



## loose

My amp was received by me in July this year and has the sylvania 5654 tubes, did the previous versions of the amp have a different set of tubes as I have been reading about the stock tubes being ge5654, are those different to the tubes I received as stock on my version 4 of the amp?


----------



## Edgard Varese

Quote: 





mrpilgrim said:


> Im considering either the little dot 1+ or the Aune t1. Could anyone provide any comparisons? Thanks


 
   
  I considered both the Aune T1 and Little Dot I+ and ended up with the Little Dot because it was more suited to what I wanted to do with it (I was originally in the market for a headphone amp).  I've had it for a couple of weeks and love it to death already (running Voskhod 6j1p-ev and an OPA2107).  I've not heard the Aune T1.
   
  Having said that, you could theoretically use both.  As I understand it, the Aune has a line out from the DAC (tube) stage which you could feed into the Little Dot.  This would give you two tube stages, which might be overkill, but I don't know (never tried it).


----------



## mab1376

Quote: 





gibosi said:


> That's a bummer!   Do you have a decent back-up?


 
   
  I have a Schiit Bifrost that's apart waiting for me to order upgrades that i haven't budgeted yet. I'll have to slap it back together tonight.


----------



## MIKELAP

Quote: 





loose said:


> This is the way I am looking at the jumpers.
> 
> As you can see the jumpers are covering the two pins on the right from this way (the volume knob can be seen at the top).
> 
> ...


 
  The way you are looking at it volume knob on top on  the right side is ok  if jumpers are on the 2 pins on the right side the setting is on the EF95 but i cant see on your picture. Stock tubes 5654 are EF95. dont know if its the same tubes on all Littledot that use 5654 tubes it goes according to the tubes they have on hand


----------



## gibosi

Quote: 





mab1376 said:


> I have a Schiit Bifrost that's apart waiting for me to order upgrades that i haven't budgeted yet. I'll have to slap it back together tonight.


 
   
  I was going to offer you my $15 ELE DAC, but I guess you won't be needing it. lol 
   
  http://www.ebay.com/itm/ELE-EL-D01-MINI-HIFI-USB-DAC-SOUND-Audio-CARD-PCM2704-BOARD-ELNA-Capacitor-S-/290908894560?pt=LH_DefaultDomain_0&hash=item43bb857560


----------



## mab1376

I actually have one too that i keep at work.
   
  Probably just going to use my iBasso D6 AUX out, just waiting on my 3.5mm to RCA cable. I had a decent one but lost it during my move last month.


----------



## hypnos1

Quote: 





acapella11 said:


> In brief, it is due to headphones and DAC-setting.
> Yes, the HD800 has a very different signature form the HD650. The HD650 is rather dark and relaxed, the HD800 brighter and "agile". The HD650 has a nicely deep but not too wide stage, The HD800 produces an immensely deep and wide room and is amazing in terms of imaging and detail. It is like an audio scalpel. If the system is not matched, you really spoil the fun. If you match the components, you go "wow !". The M-DAC also contributes a bit with its filter setting. In contrast to most DACs, the M-DAC offers the option to choose how the digital filter is optimized. In my ear, the "optimal spectrum" sounds best because it is a very punchy, detailed and true setting but also the brightest of the filters. So, the system becomes slightly brightish and this is also why a tube amp or dark SS-amp fits well. Heptodes suit actually really well, as you can imagine. I kind of like to hear "the truth", lol, and that's why the transparent and revealing character of the setup is great and good imaging is a treat. =)
> 
> 
> It is likely that the tubes sound somewhat different. Unfortunately, I didn't find a matching pair of your tubes. I bought one, only to find that the tubes were produced at different sites (Blackburn and Mazda Brussels). Then, yes, as pointed out above, HD650 and HD800 do sound very different. Probably, the HD650 much easier "buffers" a treble biased tube, so does my HE-500. Also the HD650 is more bass biased as the treble is relatively relaxed. A pure silver cable, I can imagine, would compensate for some of the HD650 darkness and open it up. Should be a good match. Overall, I actually enjoyed the HD650 after I got used to the signature and appreciated its quality and how well it scales with better gear. Lots of headroom. It just wasn't my favourite signature. 
   
  Hi A11.
   
  Nice to have more light shed on our different experiences - my poor head is now not quite so perplexed!
   
  The thought of having even more depth and width than my already tremendous 3-dimensionality, not to mention more detail/imaging than I am getting now with the EH90s 1-7 strapped has me licking my lips like a camel in heat (not a pretty sight!), and very tempted to bash the credit card in search of the 800s and nirvana...but 'she who must be obeyed' will need a heck of a lot of spoiling before I stand any chance whatsoever! Acapella, you could just have a trashed 20+ year solid relationship on your conscience!!...Ah well, all in the name of the QUEST,lol.....


----------



## MIKELAP

Quote: 





hypnos1 said:


> Hi A11.
> 
> Nice to have more light shed on our different experiences - my poor head is now not quite so perplexed!
> 
> The thought of having even more depth and width than my already tremendous 3-dimensionality, not to mention more detail/imaging than I am getting now with the EH90s 1-7 strapped has me licking my lips like a camel in heat (not a pretty sight!), and very tempted to bash the credit card in search of the 800s and nirvana...but 'she who must be obeyed' will need a heck of a lot of spoiling before I stand any chance whatsoever! Acapella, you could just have a trashed 20+ year solid relationship on your conscience!!...Ah well, all in the name of the QUEST,lol.....


 
  Heres a link to some Senns HD 800  1 and 2 years old $1100.00 and $1000.00 sorry for your relationship and your wallet lol.     http://www.canuckaudiomart.com/


----------



## Acapella11

Quote: 





gibosi said:


> Thanks! Your explanation helps me to better understand your impressions in light of my own system. My HE300 is darker than your HD800, as it is considered to be similar to the HD650, and I am currently using an OPA2107 op amp, which is also considered to be a bit dark. So it would seem to follow that there is a good chance tubes you find to be a bit too treble-inclined, such as the "foreign" Siemens, might sound quite good in my system.


 
   
  Yes, indeed.
   
  Quote: 





> However, I am preparing to roll several different op amps (LME49720HA, LME49990, and LT1028 in case anyone is interested) that are considered more neutral than the OPA217. It will be interesting to see how this changes my opinion of the 4 tubes we have in common.


 
   
  The moment your setup becomes brighter, the CV4012 might go along pretty well. Their imaging is really nice in my ears.
   
   
  Quote: 





> Originally Posted by *hypnos1* /img/forum/go_quote.gif
> Hi A11.
> Nice to have more light shed on our different experiences - my poor head is now not quite so perplexed!
> The thought of having even more depth and width than my already tremendous 3-dimensionality, not to mention more detail/imaging than I am getting now with the EH90s 1-7 strapped has me licking my lips like a camel in heat (not a pretty sight!), and very tempted to bash the credit card in search of the 800s and nirvana...but 'she who must be obeyed' will need a heck of a lot of spoiling before I stand any chance whatsoever! Acapella, you could just have a trashed 20+ year solid relationship on your conscience!!...Ah well, all in the name of the QUEST,lol.....


 
   
  I just received a pair of Valvo EH90, which sound really nice at the first impression. Having looked closer, I have seen that they are unlkiely to be matched. One says FAVC on the front and the production code is B4F3. The other has no identifiable code of production and has on the back HACA... Another pair is probably the solution, lol
   
  If the signature of the HD800 agrees with your taste, it is just an amazing headphone. My conscience is really bad already... 
   
  Quote: 





mab1376 said:


> PS Audio directly luckily said its still within warranty even though i bought it second hand through eBay. sadly I'll be mailing it out this week for repair...


 
   
  Sorry to hear but great that they still fix it. Do have the NuWave or the PerfectWave?


----------



## mab1376

Quote: 





acapella11 said:


> Sorry to hear but great that they still fix it. Do have the NuWave or the PerfectWave?


 
   
  I have the Digital Link III


----------



## hypnos1

Quote: 





mikelap said:


> Heres a link to some Senns HD 800  1 and 2 years old $1100.00 and $1000.00 sorry for your relationship and your wallet lol.     http://www.canuckaudiomart.com/


 
   
  Always suspected you have a mild(?) sadistic streak, M - have you no conscience either?!  Thanks anyway.
  Quote: 





acapella11 said:


> Yes, indeed.
> 
> 
> The moment your setup becomes brighter, the CV4012 might go along pretty well. Their imaging is really nice in my ears.
> ...


 
   
  Methinks your conscience is not suffering TOO much! - you now have me in quandary mode, never mind perplexed mode...
   
  So, A11, you have a Valvo with Blackburn code eh? Therefore no small bridging plate near the top? The toing and froing with naming and actual manufacture of these tubes is becoming quite dizzying - here goes my poor head again...As my best tubes are Siemens, but actually Blackburn-coded B5, if you could find another with similar B(4 or 5) I am sure you would be on to a winner. I wish you all the luck, lol.


----------



## MIKELAP

Quote: 





gibosi said:


> Thanks! Your explanation helps me to better understand your impressions in light of my own system. My HE300 is darker than your HD800, as it is considered to be similar to the HD650, and I am currently using an OPA2107 op amp, which is also considered to be a bit dark. So it would seem to follow that there is a good chance tubes you find to be a bit too treble-inclined, such as the "foreign" Siemens, might sound quite good in my system.
> 
> However, I am preparing to roll several different op amps (LME49720HA, LME49990, and LT1028 in case anyone is interested) that are considered more neutral than the OPA217. It will be interesting to see how this changes my opinion of the 4 tubes we have in common.


 
  The LME49720NA  those are the ones i have on hand but didnt install yet for my essence stx soundcard


----------



## mordy

While trawling the internet for tubes I came across this one:
   
  http://www.tubemuseum.org/ProductDetails.asp?ProductCode=MUL-EH90 (Please click on link to see the tube)
   
  Today I received a pair of Lorenz EH90 tubes from Herr Pultz. Did I catch the big 44 lb fish using a 6 lb line? (Did I pay $6 for a $44 tube?)

   

   

   
  First, the tubes sound great right out of the box - similar to the Siemens EH90 Foreign. The numbers 427 and 430 are present on the inside box flaps.
  One tube has the markings GE1
                                             B9C
  under the number 430. (The other tube only has a white dot on the back.) Both tubes appear to be of the same construction but the silk printing is slightly different.
  (The seller thought that they were made By Sylvania but I find it doubtful.)
   
  Would appreciate it if somebody could decipher the markings and give an idea of year of manufacture.


----------



## loose

I want to buy my first tubes after having the stock tubes now since I bought the ld mk iii a month ago.

Any recommendations for music and movies?

I use my amp for both my beyerdynamic dt880s and my Bose companion 20 speakers.

Can any tubes drive active speakers well or are they only suited to headphones?


----------



## kvtaco17

Quote: 





mordy said:


> While trawling the internet for tubes I came across this one:
> 
> http://www.tubemuseum.org/ProductDetails.asp?ProductCode=MUL-EH90 (Please click on link to see the tube)
> 
> ...


 
   
  Nice score... where did you get them I need another pair...


----------



## mordy

HI kvtaco17,
   
  Here is the link to the seller: (He only had 2 tubes when I ordered)
  Nice seller; you may want to ask him if he is getting in more. BTW, I think that I got the Siemens EH90 Foreign from him as well.
   
  http://stores.ebay.com/haunebuvintage/_i.html?_nkw=EH90&submit=Search&_sid=1045469273


----------



## gibosi

Quote: 





mordy said:


> While trawling the internet for tubes I came across this one:
> 
> http://www.tubemuseum.org/ProductDetails.asp?ProductCode=MUL-EH90 (Please click on link to see the tube)
> 
> ...


 
   
  GE1 B9C tells us that these were manufactured in the Mullard Blackburn factory.
   
  GE = EH90 and 1 = change code, so the first version of the tube.
   
  B = Blackburn
  9 = 1959 and
  C = March
   
  So yes, indeed, these are very good tubes. They should sound virtually the same as my Mullard/Blackburn Valvo EH90 and Hypnos1's Mullard/Blackburn Siemens EH90.


----------



## mordy

NOS PRISTINE MINT MUSEUM QUALITY MULLARD GREAT BRITAIN
 Mullard Tubes made for LORENZ

 6CS6 = EH90 Perfect SINGLE TUBES

 Rarest MULLARD Old Production, Halo Getters, Identical construction. Very Musical Tone with Long Life!

 Made in Blackburn, U.K., and display the B code - this one is B6G3 = 1966 manufacture date

 Almost NEVER SEEN, These are the HOLY-GRAIL of the EH90/6CS6 the ULTIMATE 6CS6!  IMPOSSIBLE TO FIND with this Quality Museum Quality Condition! Get rid of those old 6CS6 and UPGRADE to Mullard!  This tube is a "PROFESSIONAL SPECIAL QUALITY" Premium Quality Ultra RARE alternative to the 6CS6.

 THE PROFESSIONAL CHOICE for McIntosh Tuners MR-65, MR-65A, MR-65B, MR-66, MR- 67, MR-71

 These tubes are an important integral tube in the overall sound, reliability and performance of your tuner.  

 The FINEST Made in U.K. 6CS6 tube one can find!

 
  Hi Gibosi,
   
  Many thanks for providing the manufacturing and date information. Looks like I got the big one. These tubes sound very musical and sweet. Is there any truth to the hype in the ad on the right?


----------



## gibosi

Not really. Mullard/Blackburn EH90s are certainly not rare. After all, I alone have four of these tubes, two Valvo and two Siemens, and like you, didn't pay much at all for them. Now perhaps Mullard-made EH90 with Lorenz painted on them might be somewhat rare. lol That said, many of us who have these Mullard EH90s believe they are top tier. They are certainly one of my favorites, very musical, with extremely good bass and treble detail.


----------



## Oskari

Quote: 





mordy said:


> Is there any truth to the hype in the ad on the right?


 
   
  It's just more of the usual hubris (and largely insane prices) from "Tube Museum New York".


----------



## kvtaco17

Anyone know anything about Ediswan tubes? I couldn't find much about the company (where the Edison/Swan love children were produced and by whom) BUT I have a deal on 2 EH90's and was curious if I should pull the trigger.


----------



## gibosi

Quote: 





kvtaco17 said:


> Anyone know anything about Ediswan tubes? I couldn't find much about the company (where the Edison/Swan love children were produced and by whom) BUT I have a deal on 2 EH90's and was curious if I should pull the trigger.


 
   
  I have nothing on Ediswan tubes, so it seems to me you must purchase these in order to further the edification of this forum.


----------



## duncan1

Edison/Swan electric co. LTD---155 Charring Cross Road London WC5--Founded 1893/1916--One of the first tube manufacturers in GB.[UK] --Brands=Ediswan/Mazda --BTH acquired Ediswan in 1928-1929. Also subsidiary in France.. I have many Mazda tubes also made tube bases. using P.T.F.C.E- I also have many tube equivalent books by Mazda came out with many  tube innovations can list them if needed.---Found one of my Mazda equiv. books.The company were taken over by Thorn-AEI valves+ tubes-7 Soho SQ. London W.1   ---First tube=The Worlds FIRST tube for commercial sale =The Ediswan Diode Fleming Oscillation tube.-1906 The AC/HL/DDD=The Worlds first Triple Diode Triode=1933. QP240 -  The Worlds First Double Pentode Tube    . 9MH -Worlds First magnetically deflected  TV picture tube circa=1936  ---You   see -not all innovations occurred in modern times. John Logie Baird born in Helensburgh -Scotland. TV inventor.  Demonstrated   color TV--3D TV . stereo TV in the 40s.


----------



## gibosi

Quote: 





kvtaco17 said:


> Anyone know anything about Ediswan tubes? I couldn't find much about the company (where the Edison/Swan love children were produced and by whom) BUT I have a deal on 2 EH90's and was curious if I should pull the trigger.


 
   
  Just a hunch, but I would guess that these were made by Philips/M.B.L.E Mazda. You might remember that AFB wrote about his M.B.L.E Mazda EH90 *here*. Probably very similar to Philips/Mullard EH90. But again, just guessing....


----------



## mordy

Hi kvtaco 17 and Duncan 1,
   
   
  Did a little research on the Ediswan brand.
   
  The name comes from Joseph Swan, who was the first one to invent the electric light bulb, before Edison. Edison collaborated with Swan on producing light bulbs, hence the name EDISWAN.
   
  Here are three quotes:


by *JeffWest* on Wed Mar 07, 2007 6:23 am
  Ediswan was very early British electric lamp company, formed 124 years ago by merging of British Edison (yes, that Edison) and Swan United Electric. Famous as first manufacturer of radio valves anywhere, directly courtesy of Fleming who was collaborating with them and apparently directing their fabrication of prototypes. Ediswan made all valves for Marconi through WWI and prior to formation of M-OV, was a charter member of BVA . . . and accomplished other valve-related things of note.

 As early 20th century wore on, Ediswan merged with British Thompson-Houston to become part of Associated Electrical Industries, Ltd. (AEI) and their receiving tubes were mostly sold as British Mazdas, with "Ediswan" reserved for industrial valves and some foreign markets, I think . . . skipping ahead, at the very end of the 1950s, AEI merged with Thorn Electrical Industries and became new collective owners of Brimar Valve Division that was released for sale by STC and so . . . after about 1959 or '60, both "Brimar" and "Ediswan" brands were owned and used for tubes produced (or sourced) by the company subsequently and logically known as Thorn-AEI Radio Valves & Tubes, Ltd.

 So, as with that nice tube shown, at that point an "Ediswan" could really be a Brimar, and vice versa.

  
  
 *History*
The foundations of British Thomson-Houston (BTH) were laid in 1886, when a London firm Laing, Wharton and Down was formed to exploit in the United Kingdom the sale of products made by the American Electric Co.  “_Thomson-Houston (BTH)”_ was merged with the similar _“Metropolitan-Vickers Company”_ in 1928, but the two maintained their own identities until 1960. The holding company, _“Associated Electrical Industries (AEI)”_,  was formed in 1929 and was initially a financial holding company for a number of leading electrical manufacturing and trading companies in the United Kingdom. These included British Thomson-Houston, Metropolitan-Vickers, Edison Swann and Ferguson Pailin. In 1959 AEI became a trading company and the AEI symbol began to replace most of the brand names and trademarks of companies within the group. 




 Ediswan  In 1883 the Edison & Swan United Electric Light Company was established. Known commonly as _Ediswan_, the company sold lamps made with a cellulose filament that Swan had invented in 1881. Variations of the cellulose filament became an industry standard, except with the Edison Company. Edison continued using bamboo filaments until the 1892 merger that created Edison General Electric, and that company then shifted to cellulose.
  In 1886 Ediswan moved production to a former jute mill at Ponders End, North London.[19] In 1916 Ediswan set up Britain's first radio thermionic valve factory at Ponders End. This area, with nearby Brimsdown subsequently developed as a centre for the manufacture of thermionic valves, cathode ray tubes, etc. and nearby parts of Enfield became an important centre of the electronics industry for much of the 20th century. Ediswan became part of British Thomson-Houston and Associated Electrical Industries (AEI) in the late 1920s.[20
   
  In short, a very distinguished British manufacturer.  My guess is that the tubes kvtaco 17 is looking at may be made by Brimar and manufactured in the 50's (?).


----------



## gibosi

So, they might be Mazda? Or Brimar? *kvtaco 17* please buy these! I want to know! lol


----------



## duncan1

Mazda -EH90--US equiv.=6cs6  ----Mazda version= HF Dual Control Heptode Rating=1Watt---Plate=100V--Grid/2/4=30V --Grid 3 =0 or -1---Grid 1=-1 or 0- current[plate]=0.8/0.75MA--current Grid3/4=4/1.1---Gain [G M]=1.2 MA/V---Remember this is for the MAZDA -EH90- ANY other equiv. maker might have different specs. But Mazda are a good tube company no doubt about it.


----------



## hypnos1

Quote: 





mordy said:


> While trawling the internet for tubes I came across this one:
> 
> http://www.tubemuseum.org/ProductDetails.asp?ProductCode=MUL-EH90 (Please click on link to see the tube)
> 
> ...


 
   
  Hi mordy,
   
  As gibosi has already mentioned, it looks like you may just have struck gold - most certainly if BOTH are GE1, B9(or similar). My Siemens B5I4s also have GE1 on 'em, and with even more burn-in on 1-7 just keep getting better and better - I cannot believe what is coming out of the HD650s. Give them a good 40hrs (although they are magical on even just 10+ hrs) and I am sure you too will be amazed. I certainly hope so...


----------



## hypnos1

A quick note for Acapella11 and mikelap...(and anyone else interested).
   
  Worry no longer (if at all!!) about your conscience - either further burn-in of grid 3 on 1-7 strap has worked miracles, or my 650s caught wind of the plot, but the amount of detail now assailing my ears is unbelievable. Now I truly know what is meant by REVEALING...if the 800s dissect the recording even more (which of course they do...), I don't think I would really want the imperfections highlighted to any greater degree. So HALLELUJA, my relationship - not to mention wallet - are safe once more. For now, at least!
   
  Cheers,
   
  One very happy bunny (or rather TWO!)


----------



## MIKELAP

Hey gibosi you will  be happy to know that i will be getting 5 Westinghouse 6AV6 right now burnin a pair of 1950's Lorenz EBC 91/6AV6 which by the way sound very good very clean detailed tube and very good  bass testing with my regular tune and bass seems to be more present then other 6av6 dont ask me which ones i got 6 pairs going from memory here or what left of it . listening  with Senns HD800 by the way .Checking out  Littledot MKIV SE tempting like you said Christmas is coming


----------



## mordy

Hi Hypnos1,
   
  Only one tube have the Blackburn code. The other one looks almost identical, but no visible code. Each tube has a number with the corresponding same number on the inside box flap. The coded tube is numbered 430, the uncoded 427. The two boxes are slightly different in color as well. (Could be from sitting in the sun maybe.)
   
  First put them in plug&play (no strap). They sounded very good, but after a while I heard a hum in the right channel. Then I tried 1/7 strap setting, and the hum went away. Sounds good; so far 8 hours.
   
  Some time back inphu510n asked if tubes get "tired" if they are left on too long.
  Don't know, but maybe cranky.
   
  I have a Tesla heptode 6H31 that sounded very good in the bass and treble, but had the mid range blues - a certain coolness and timbre coloration in the mid range. Gave it 50 hours with a little bit of improvement. Then I decided to cook it another 35 hours  (Voskhod memories) and left it on continuously. I have run other tubes that long, watching that the amp stays quite cool, without untoward effects. The mid range on the Teslas improved, but the treble became unpleasantly sharp (cranky and screaming). Have to return to this tube and evaluate further.
   
  So now I do 8 hours burn in at a time since I  have the perceived impression I have something rare in my hands....


----------



## MIKELAP

Quote: 





hypnos1 said:


> A quick note for Acapella11 and mikelap...(and anyone else interested).
> 
> Worry no longer (if at all!!) about your conscience - either further burn-in of grid 3 on 1-7 strap has worked miracles, or my 650s caught wind of the plot, but the amount of detail now assailing my ears is unbelievable. Now I truly know what is meant by REVEALING...if the 800s dissect the recording even more (which of course they do...), I don't think I would really want the imperfections highlighted to any greater degree. So HALLELUJA, my relationship - not to mention wallet - are safe once more. For now, at least!
> 
> ...


 
  Crisis averted that was close lol .


----------



## Oskari

Quote: 





mordy said:


> In short, a very distinguished British manufacturer.  My guess is that the tubes kvtaco 17 is looking at may be made by Brimar and manufactured in the 50's (?).


 
   
  That could well be, or, as always, they could be from anywhere. After 1961 Ediswan, Mazda (UK) and Brimar were brands of a Thorn/AEI joint venture of their tube interests.
   

 http://www.gracesguide.co.uk/Edison_Swan_Electric_Co


----------



## Oskari

Quote: 





mordy said:


> Only one tube have the Blackburn code. The other one looks almost identical, but no visible code.


 
   
  There is a code! It's just much fainter.


----------



## Oskari

Quote: 





gibosi said:


> Just a hunch, but I would guess that these were made by Philips/M.B.L.E Mazda.


 
   
  That's of course always possible but I don't think that the UK Mazda and the Belgian Mazda were related, at least not at this point. The French Mazda and the UK Mazda were originally related but not at this point. The French Mazda and The Belgian Mazda were somehow (loosely?) related via Philips at this point, I think. This is all very complicated...


----------



## gibosi

Quote: 





oskari said:


> That's of course always possible but I don't think that the UK Mazda and the Belgian Mazda were related, at least not at this point. The French Mazda and the UK Mazda were originally related but not at this point. The French Mazda and The Belgian Mazda were somehow (loosely?) related via Philips at this point, I think. This is all very complicated...


 
   
  Yes, it is complicated as these tubes could have been made in any one of a number of different factories. Until one of us has one of these tubes in his/her hands, all we can do is guess. So again, I really do hope that *kvtaco17 *decides to buy these. I love a good tube mystery. lol


----------



## mordy

Hi Oskari,
   
  I tried to look very carefully on the tube, but I couldn't see any code, even with a magnifying glass. Appreciate your good wishes that it is a pair - sounds the same.


----------



## gibosi

Quote: 





mikelap said:


> Hey gibosi you will  be happy to know that i will be getting 5 Westinghouse 6AV6 right now burnin a pair of 1950's Lorenz EBC 91/6AV6 which by the way sound very good very clean detailed tube and very good  bass testing with my regular tune and bass seems to be more present then other 6av6 dont ask me which ones i got 6 pairs going from memory here or what left of it . listening  with Senns HD800 by the way .Checking out  Littledot MKIV SE tempting like you said Christmas is coming


 
   
  The Westinghouse are coming!! Yippee! lol
   
  And yes indeed, the Lorenz EBC91 are great tubes, one of my favorite triodes, so I am not surprised that you are liking them.


----------



## gibosi

Quote: 





mordy said:


> Hi Oskari,
> 
> I tried to look very carefully on the tube, but I couldn't see any code, even with a magnifying glass. Appreciate your good wishes that it is a pair - sounds the same.


 
   
  I don't know how many times I examined one of my Mullard/Blackburn Siemens EH90 looking for those codes, and one day, I had the light positioned at just the right angle and these codes very faintly appeared, one by one, as I rolled the tube in the light. I was not really seeing the etching, but rather, I was seeing the difference in the light being reflected off the tube. The etched area was less reflective. So like Oskari says, the codes are most certainly there, but very faint.


----------



## Oskari

Yeah, I think I see a partial code in one of the photos. (Are those the actual tubes?)


----------



## mordy

Hi Gibosi and Oskari,
   
  OK,OK, I am going to try again to see if I can see the invisible codes on the other tube. And yes, those are the actual tubes photographed in my el cheapo light box.
   
  Definitively true that by turning the tube in the right kind of indirect light you can sometimes pick up almost invisible codes.
   
  However, now I am listening to them so it has to wait a little.
   
  Stay tuned for the latest findings....


----------



## Oskari

Quote: 





gibosi said:


> Yes, it is complicated as these tubes could have been made in any one of a number of different factories. Until one of us has one of these tubes in his/her hands, all we can do is guess.


 
   
  That's right, and the next batch could come from a completely different factory.


----------



## kvtaco17

I was gonna go for it, I'll post pics when I get them... (it'll be a few weeks cuz of shipping)


----------



## Acapella11

Quote: 





hypnos1 said:


> A quick note for Acapella11 and mikelap...(and anyone else interested).
> 
> Worry no longer (if at all!!) about your conscience - either further burn-in of grid 3 on 1-7 strap has worked miracles, or my 650s caught wind of the plot, but the amount of detail now assailing my ears is unbelievable. Now I truly know what is meant by REVEALING...if the 800s dissect the recording even more (which of course they do...), I don't think I would really want the imperfections highlighted to any greater degree. So HALLELUJA, my relationship - not to mention wallet - are safe once more. For now, at least!
> 
> ...


 

 And that even saves you from buying new tubes! For now at least


----------



## MIKELAP

Quote: 





mordy said:


> Hi Gibosi and Oskari,
> 
> OK,OK, I am going to try again to see if I can see the invisible codes on the other tube. And yes, those are the actual tubes photographed in my el cheapo light box.
> 
> ...


 
  You should try these mordy


----------



## mordy

I'm afraid that these won't do the trick because it says that they are not suitable for use with prescription lenses. I'll spend the $7.99 on another pair of tubes....
   
   
  http://www.retroplanet.com/PROD/25348?CPID=GDF100&utm_source=google&utm_medium=datafeed&utm_campaign=GoogleBase&utm_content=25348&gclid=CO7z-Ojn_bgCFcef4AodnlAALQ


----------



## Acapella11

Can anyone decipher the four digit codes on Valvo EH90 tubes: FAVC, HACA, FCPC...?


----------



## mab1376

Anyone know a good source of Lorenz and Siemens EH90?
   
  Also got my [size=x-small]Mullard 10M Master series EBC91/6AV6 today, will start rolling the 6AV6's this week.[/size]


----------



## gibosi

Quote: 





acapella11 said:


> Can anyone decipher the four digit codes on Valvo EH90 tubes: FAVC, HACA, FCPC...?


 
   
  As best I can figure out, these are some kind of batch code that had meaning within the Valvo. And of course, it is reassuring if you have two tubes with the same number. But for our purposes, the Philips tube codes are the key. As long as you have two tubes manufactured in the same factory at about the same time, I believe you have a good matched pair.


----------



## gibosi

Quote: 





mab1376 said:


> Anyone know a good source of Lorenz and Siemens EH90?


 
   
  I have seen three different EH90 tubes labeled Siemens and two labeled Lorenz, and there may well be more. The easiest to find are the Philips-made tubes. The brand painted on the outside doesn't matter, so a Lorenz, Siemens, Valvo, etc., are all the same tube. In this case, you are looking for smooth plates with squarish holes like the Lorenz in the pictures that Mordy recently posted  Finding non-Philips tubes are a different story....


----------



## mab1376

Quote: 





mab1376 said:


> Anyone know a good source of Lorenz and Siemens EH90?
> 
> Also got my [size=x-small]Mullard 10M Master series EBC91/6AV6 today, will start rolling the 6AV6's this week.[/size]


 
  How fancy!


----------



## mordy

"Anyone know a good source of Lorenz and Siemens EH90?"
   
  Found these Valvo tubes on German Ebay. 6 available for EUR 5.90 - shipping any quantity up to 20 tubes EUR 7.00. They look similar to what I have, _but cannot know for sure_. You may want to communicate with the seller and ask what the markings are on the tube. Via Google translate:
   
  Hi Rosemarie,

 Could you tell me where these tubes were manufactured?
 Are there any markings on the vacuum tube such as GE1 /B9C?
 Thanks,
   
   
  Hallo Rosemarie,

 Können Sie mir sagen, wo diese Rohre hergestellt wurden?
 Gibt es irgendwelche Markierungen auf der Vakuumröhre wie GE1 / B9C?
 Danke,
   
   
   
   
  http://www.ebay.de/itm/EH90-EH-90-6CS6-VALVO-NOS-NEW-MCINTOSH/221267124842?_trksid=p5197.m1992&_trkparms=aid%3D111000%26algo%3DREC.CURRENT%26ao%3D1%26asc%3D14%26meid%3D573359491921851665%26pid%3D100015%26prg%3D1006%26rk%3D1%26rkt%3D10%26sd%3D221267124842%26
   
   
  I am not bidding on these because they are beyond my tube budget, but maybe somebody is interested.....


----------



## MIKELAP

Quote: 





mordy said:


> I'm afraid that these won't do the trick because it says that they are not suitable for use with prescription lenses. I'll spend the $7.99 on another pair of tubes....
> 
> 
> http://www.retroplanet.com/PROD/25348?CPID=GDF100&utm_source=google&utm_medium=datafeed&utm_campaign=GoogleBase&utm_content=25348&gclid=CO7z-Ojn_bgCFcef4AodnlAALQ


 
  Thanks for the link mordy i love this stuff to bad for the glasses they dont even produce x-rays what a scam !


----------



## gibosi

Quote: 





mordy said:


> "Anyone know a good source of Lorenz and Siemens EH90?"
> 
> Found these Valvo tubes on German Ebay. 6 available for EUR 5.90 - shipping any quantity up to 20 tubes EUR 7.00. They look similar to what I have, _but cannot know for sure_. You may want to communicate with the seller and ask what the markings are on the tube. Via Google translate:
> 
> http://www.ebay.de/itm/EH90-EH-90-6CS6-VALVO-NOS-NEW-MCINTOSH/221267124842?_trksid=p5197.m1992&_trkparms=aid%3D111000%26algo%3DREC.CURRENT%26ao%3D1%26asc%3D14%26meid%3D573359491921851665%26pid%3D100015%26prg%3D1006%26rk%3D1%26rkt%3D10%26sd%3D221267124842%26


 
   
  With the smooth plates and squarish holes, these were definitely made in one of the Philips factories. To quote AFB, these tubes just "scream Philips". lol, And I have been quite impressed with Philips' quality control across their factories. I have a two triodes, one made in the Blackburn factory and the other in the Heerlen factory that sound the same to my ears. And even better, one of our colleagues reports that he has one Philips EH90 made in Blackburn and one made in Hamburg, and they match perfectly. So I don't think it is all that important which Philips factory manufactured these, but of course it would be best if they came from the same factory. If someone wants a pair of Philips-made EH90, and the price is acceptable, these should fine.
   
  Edit: Zooming the vendor's picture, it sure looks like there is a "B" etched into the glass on the lower back side of the tube, which would indicate the Blackburn factory.....


----------



## foreign

Can anyone help me I'm trying to find either of these 2 tubes to buy but can't find them anywhere. 
1. Voshad 6zh1p-ev (ef95 family)
2. Mullard m8161/ cv401
Does anyone know where I can buy them?


----------



## gibosi

Quote: 





foreign said:


> Can anyone help me I'm trying to find either of these 2 tubes to buy but can't find them anywhere.
> 1. Voshad 6zh1p-ev (ef95 family)
> 2. Mullard m8161/ cv401
> Does anyone know where I can buy them?


 
   
  Voskhod:
   
  http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=130436695928&ssPageName=ADME:L:OC:US:3160
   
  Mullard:
   
  http://www.ebay.com/itm/M8161-EF92-6065-CV4015-MULLARD-NOS-/310391381072?pt=UK_Sound_Vision_Valves_Vacuum_Tubes&hash=item4844c49c50


----------



## foreign

gibosi said:


> Voskhod:
> 
> http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=130436695928&ssPageName=ADME:L:OC:US:3160
> 
> ...



Gibosi thankyou so much I really appreciate your effort.


----------



## mordy

In our quest for EH90 tubes we are now going "down under" to Australia:
   
  http://www.ebay.com/itm/20-X-EH90-MULLARD-NOS-TUBES-/310719643962?pt=LH_DefaultDomain_0&hash=item485855813a
   
  According to the vendor, these tubes are [size=10pt]Mullard tubes ( nos ) made in Australia ( C-codes ) = Hendon Works, Alberton, Australia[/size]
   
  Does anybody have any experience with these tubes?
   
  My 6AK5 odyssey started when I ordered Mullard look alike tubes, including the plastic pin protector, that looked exactly like the Mullard CV4010. Thought that I got real Mullard tubes at a bargain. Turned out that they were made by Amalgamated of Sydney, Australia. They did not sound good.
   
  Here are some snippets of Australian tube manufacturing history, just as convoluted as the European Phillips saga: If you don't have the patience to read through it, the most significant findings are 1) that the cathode assemblies were manufactured in Blackburn and shipped to Australia; the AU factory did not even have the facilities to manufacture them. Thus, "the classic Mullard sound."
  2) A lot of tubes for Australian use were manufactured by the Yugoslavian factory Ei.
   
  What goes around comes around.....
   
 Re: Mullards Made in Australia? 

by *JeffWest* on Sat Dec 04, 2004 1:46 pm
  There were at least three major operations producing valves in Australia, dating back to the '20s. One was Amalgamated Wireless Australasia, LTD (AWA), quite famous in vintage radio circles I'm told, which formed the Amalgamated Wireless Valve Company (AWV!) and sold tubes under the Super Radiotron brand. Philips decided to manufacture there (Australia) before WWII and had a factory in New South Wales, but right after the war moved production to the Hendon factory in South Australia. The Philips factory code for Hendon is the "C" you noticed on one of those tubes, like Adrian said. The Stokes book implies they were making 12AX7s there by 1958, and I think I recall seeing longplates w/"C" codes, not positive, most you encounter are 15mm that look like British or Dutch. I've got a couple of the latter around here somewhere, w/"C" codes and labelled "Miniwatt". As I recall, they sound pretty good, like other Philips.

 For those who might have Australian CV versions, the factory code for Hendon Works in that case is "PDA" (like "Z" for Hammersmith on CV coded KT66s, etc).

 All the Australian tube factories had ceased production by the mid '70s.

 "I6_" is Philips type code for ECC83/12AX7 from very late '50s through '70s. The last digit isn't necessarily chronological, e.g., I65 appeared on Dutch years before I63 on British, etc. I don't remember the full type code on the Australian Miniwatts I've got, should check.

 Nice to have a bit of history with the valves
 I was talking to a retired radio repairer
 seem to think when production stopped the machines were dismantled and never re-sold.so nobody else could manufacture them .Sounds like an urban myth but who knows?

 Today's secret revealed - the valves made in the Alberton factory used cathode assemblies made in Blackburn, Lancashire, and transported around the world to Australia.

 Tungsram developed a way to transport cathode assemblies from Hungary to GB before WWII, so that they could make valves without giving the "special recipe" to foreigners. During WWII the Tungsram Edmonton (Tottenham) factory was used by Mullard, and the technology came into their control. After the war, Mullard used the Tungsram method to send cathode assemblies to Hendon, Alberton, West Adelaide (call it what you like, only one factory).

 Today's secret revealed - the valves made in the Alberton factory used cathode assemblies made in Blackburn, Lancashire, and transported around the world to Australia.
 The Hendon works had no facilities for coating cathodes. All Philips group valves produced in Oz used European cathode assemblies (all from Blackburn, as far as I know, but I'm hedging my bets). That is why they have that classic sound
 I was aware of the British Tungsram importation of Hungarian parts, it helped keep them out of BVA secondary to the argument that they weren't really offering fully "British made" valves. I believe Dutch Philips took over British Tungsram by 1952 and put Mullard in charge of managing it as of late that year. 
 From my sometimes defective memory, Philips production of the ECC82 and ECC83 began around the middle of 1953, with the ECC81 first being produced 10 months earlier. I don't know much more, I picked that up from old advertising material, and it might have been 54, not 53. LOL I couldn't even speak then, it was a long time ago!

 I have some old Australian-sourced Miniwatt ECC83 that were made in the Yugoslavian Ei factory. The ones I have appear to be real 50s vintage, but there are a lot of copies about, also made by Ei but much later, with all sorts of names on them (I have a couple marked "Siemens", and some more marked "Mazda"). The Ei factory Philips code is a circle, broken at the bottom, with a blob in the centre, and the codes are a character shorter than usual. I have been told that a lot of Philips group valves supplied to Australia in the 50s were made by Ei.


----------



## MIKELAP

Quote: 





foreign said:


> Can anyone help me I'm trying to find either of these 2 tubes to buy but can't find them anywhere.
> 1. Voshad 6zh1p-ev (ef95 family)
> 2. Mullard m8161/ cv401
> Does anyone know where I can buy them?


 
  Voshkod 6ZH1P-EV    http://stores.ebay.com/Yen-Audio/Little-Dot-Tubes-/_i.html?_fsub=2462279010&_sid=1064920990&_trksid=p4634.c0.m322


----------



## foreign

mikelap said:


> Voshkod 6ZH1P-EV    http://stores.ebay.com/Yen-Audio/Little-Dot-Tubes-/_i.html?_fsub=2462279010&_sid=1064920990&_trksid=p4634.c0.m322



Thanks I found this site a little earlier and purchased a pair of tubes can't wait till they get here to try them out. I appreciate the help as always . Mike
The only other advice I need is power tubes a worthy upgrade aswell? 
There's the 6h6pi Novosibirsk would this be a slight upgrade over the standard ld. Mk3 cheers


----------



## Oskari

About Yen Audio: http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/2235#post_9687523
   
_"I wouldn't buy from them in the first place. Overpriced and a sketchy history."_
   
  I'll have to agree.
   
  P.S. It's Voskhod, not Voshkod.


----------



## MIKELAP

Found this maybe it could be useful  Amperex Mullard  Phillips and Valvo date codes               http://www.audiotubes.com/mullcode.htm
   
  and at the bottom theres a pdf. of a tube type code list looks interesting                                       http://www.triodeel.com/images/philipstubecodes.pdf


----------



## foreign

Is the power tubes in the little dot mk3 worth upgrading? 
6h6pi Novosibirsk
I'm happy to give them a try but would like to know if anyone has tried them?


----------



## MIKELAP

Quote: 





oskari said:


> About Yen Audio: http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/2235#post_9687523
> 
> _"I wouldn't buy from them in the first place. Overpriced and a sketchy history."_
> 
> ...


 
  I bought from this guy once had no problem would i pay $36.00 + shipping again for 2 tubes no way but thats me.Just paid $24.50 including shipping for 5  6AV6 tubes, that i like. As for the spelling your right heard that before i guess Yen doesnt know either !


----------



## foreign

foreign said:


> Is the power tubes in the little dot mk3 worth upgrading?
> 6h6pi Novosibirsk
> I'm happy to give them a try but would like to know if anyone has tried them?



Lol they are the same as the stock power tubes guess you can't change the power tubes on the little dot mk3 oh well.


----------



## MIKELAP

Quote: 





foreign said:


> Lol they are the same as the stock power tubes guess you can't change the power tubes on the little dot mk3 oh well.


 
   
   
  Quote: 





foreign said:


> Lol they are the same as the stock power tubes guess you can't change the power tubes on the little dot mk3 oh well.


 
  You can upgrade to these
  6H30Pi gold pins
  or some prefer these 6N6P-IR
   or the way more expensive 6H30P-DR 
  super tube


----------



## mordy

Hi Foreign,
   
  There is another alternative that I have happily used for the last year and a half - 6N6P gold grid tubes. To me these sound better than the stock 6N6P-i. The sound is more mellow and they have a beneficial effect on driver tubes that are skewed towards treble by toning them down a little. (BTW, the gold grid was invented by GE and used in their 5 Star extra long life tubes. However, nobody bothers to mention this.)
   
  The best deals on Ebay for the Russian tubes seem to be 4 tubes for $18 including shipping ($17 for 2 tubes). The general consensus  is to avoid Russian tubes made after 1983 since it seems that the quality started to decline. Ask the vendor what year the tubes were made. This does not apply to the Electro Harmonix tubes which are currently in production and not NOS.
   
  I finally caved in a bought a pair of 6N6P-IR tubes, but they have not arrived yet. Shipping from Russia can take four weeks or more. I do not have experience with Electro Harmonix and DR tubes.


----------



## mordy

Anybody heard about this brand?


----------



## gibosi

Never heard of it before, but the box is identical to an older RCA box....


----------



## siles1991

Hey guys the lot of 5 is back! http://www.ebay.com.my/itm/JAN-6AH6-WA-Tubes-Tung-Sol-1967-NOS-Lot-of-5-Tested-Strong-/251320352568?pt=Vintage_Electronics_R2&hash=item3a83dc3f38&_uhb=1#ht_716wt_1139
   
  If no one gets it in like 2 months im gonna snag it again xD so I can have a lifetime supply of 6ah6wa. they sound really really good.


----------



## siles1991

Quote: 





mordy said:


> Hi Foreign,
> 
> There is another alternative that I have happily used for the last year and a half - 6N6P gold grid tubes. To me these sound better than the stock 6N6P-i. The sound is more mellow and they have a beneficial effect on driver tubes that are skewed towards treble by toning them down a little. (BTW, the gold grid was invented by GE and used in their 5 Star extra long life tubes. However, nobody bothers to mention this.)
> 
> ...


 
  i know how ya feel on the wait mordy, i'm not only waiting for my 6n6p-ir's to arrive from russia but my mkiv se as well from china! hope they will blow my mind


----------



## mordy

Hi Siles 1991,
   
  When I bought my MKIII it had just been written up in Stereophile magazine. Suddenly there was a lot of interest in it, and I had to wait around five months for my unit to arrive.
  Then you have wait around 100 hours to burn in the amp, and then for every pair of tubes you need some 50 hours burn in. Patience, patience.
   
  So I am used to waiting, and since I have what to listen to it does not bother me to wait a month or so for tubes. But I do remember how it felt to wait for the original delivery.
   
   
  I had absolutely no background with tubes and tube amps. The first time I decided to roll a set of tubes I did not even know how to do it. The sockets were of course all new, and very tight. Finally I took a deep breath and yanked out the first tube which wasn't so easy. (All you dentists out there, do you remember the first extraction?)
  Anyhow, now I know to use one of those rubber fingers which makes it much easier. And after rolling numerous tubes the sockets are not tight any more. It's just like plugging in a plug in the wall...
   
  Have fun!
   
  PS: The mailman just rang the bell and asked me to sign for the 6N6P-IR tubes. Took 18 days - last time it took more than 4 weeks to get a package from the Ural mountains....


----------



## foreign

mikelap said:


> You can upgrade to these
> 
> 
> 6H30Pi gold pins
> ...



Thanks I got s little carried away and bought a whole heap of new tubes to try and power tubes . Should keep me busy the next few months especially working to pay them off lol. But hey that's why I bought the tube amp for to try different sounds and experiment and enjoy the music along the way.
Bought 
voshkod 6zh1p-ev
Hytron jhy6ak5w
Power tubes
6n6pi Novosibirsk
6h30pi sovtek


----------



## vic2vic

Quote: 





mordy said:


> PS: The mailman just rang the bell and asked me to sign for the 6N6P-IR tubes. Took 18 days - last time it took more than 4 weeks to get a package from the Ural mountains....


 
   
  Hi Mordy,
  I'd be really interested to hear a comparison between the 6N6P-IR and the 6N6P Gold grid (I think you are using these ones right now, correct ?).
  By the way, which month/year are the 6N6P-IR that you received ?
  Thanks


----------



## gibosi

Received a pair of Lorenz EH90 in the mail today:
   

   
  As you can see, these look nothing like the Philips/Blackburn Lorenz that Mordy recently received. There are what look like 6 little vertical spot-welds on the plates, and "Lorenz" and "Made in Germany" etched into the glass, but no visible factory date codes. And most interestingly, these have a Telefunken-like diamond impressed in the glass between the pins. However, these look nothing like the Ulm-made Telefunken EH90 that a number of us have. Another mystery tube from Germany... lol


----------



## Acapella11

Thanks gibosi for recommending these IBM 1680 6BE6 tubes.
   
  I put them in two hours ago and I must say that I am impressed. I will wait 30h and compare them with other tubes but surely, these are great tubes!
   
  Mordy, how do you like your new power tubes?


----------



## mordy

Hi vic2vic,
   
  You are right, just plugged in the IR tubes. Got these from El-Rayder in Ulyanovsk, Russia. The date is 02/1983.  I had asked for older ones, but he couldn't get them.
   
  The older gold grid ones were from X/78 (oct 1978).
	

	
	
		
		

		
		
	


	



   
  It is hard to get an impression right away after a few minutes, but initial impression is more punch in the bass ("bouncy Tung Sol punch")  and brighter glow than the previous tubes.
   
  Did anybody ever solve the mystery of the OTK ratings? These new ones say OTK 5. Maybe it is just a quality control stamp like "passed" on the Chinese stuff with an inspector's number.
   
  A true evaluation has to wait for a while.....


----------



## Acapella11

These are my impressions as well and check out the stage!
   
  Happy listening
  
  OTK, exactly as you guessed:
   
  Quote: 





> Actually, OTK means Quality Control Departments. Such mark has a personal number of the worker who tested the tube, and found it is within specs. If later discovered that the product is out of specs OTK manager knows who is guilty, by the personal number that belongs to the tester.


 
   
  From: http://www.diyaudio.com/forums/swap-meet/163648-russian-6n8s-6h8c-6sn7gt-1578-metal-base-nos.html, post #3


----------



## mab1376

Quote: 





acapella11 said:


> Thanks gibosi for recommending these IBM 1680 6BE6 tubes.
> 
> I put them in two hours ago and I must say that I am impressed. I will wait 30h and compare them with other tubes but surely, these are great tubes!
> 
> Mordy, how do you like your new power tubes?


 
   
  How would you compare these to other 6BE6/EK90, the first think that stands out to me is they a way more bass heavy compared to my Telefunken and Siemens (Haltron).


----------



## gibosi

Quote: 





acapella11 said:


> Thanks gibosi for recommending these IBM 1680 6BE6 tubes.
> 
> I put them in two hours ago and I must say that I am impressed. I will wait 30h and compare them with other tubes but surely, these are great tubes!


 
   
  I'm glad to hear that you are liking them. And now that I understand that your setup is a bit brighter than mine, I imagine they sound even better than they do in mine.
   
  Cheers!


----------



## jaywillin

well, my heart skipped a little beat this morning, when i got to the puter, and after turning it on, and then reaching for the little dot to turn it on
  seeing that i had left it on all night ! sounded fine, the rca's should be properly burned in now ! lol
  so, its taking a break for now, maybe  i'll give the g3 some playing time today, it sounds pretty good with its rca 12au7 clear tops


----------



## Acapella11

Quote: 





mab1376 said:


> How would you compare these to other 6BE6/EK90, the first think that stands out to me is they a way more bass heavy compared to my Telefunken and Siemens (Haltron).


 

   
  Hi mab1376, I wouldn't want to do the comparison right now. Initial impressions are that they are well balanced, not too refined and extended treble, very good imaging going along with loads of detail and hard hitting bass - just the amount I need.  Could absolutely be that you require less for a good balance. For me it works pretty well. More of that later.
   
  Quote: 





gibosi said:


> I'm glad to hear that you are liking them. And now that I understand that your setup is a bit brighter than mine, I imagine they sound even better than they do in mine.
> 
> Cheers!


 
   
  First impression is that they have exactly the tonal balance I can use well, including the details I love.


----------



## siles1991

Hey guys I was wondering if there's anyone here who is nice enough to let me send tubes to them, than send it to me in a single package. If I keep buying tubes from like different sellers I have to pay like a lot since I live in Malaysia, so was thinking if anyone would let me send it to them instead which would let me save a crud load of money on shipping. Also sometimes ebay sellers overcharge me on shipping...
   
  The perks are, they can try out the tubes before they send them to me. I'll give time for you guys to try out the tubes, if you havn't tried them out already.


----------



## jaywillin

new tube arrived from a buy off ebay, the cbs hytron 6cs6,  plugged into the amp in the ef95 setting, loud constant hum
  changed amp to ef91 the same loud constant hum, bad tubes ? wrong setting, wrong tubes  ? i've been doing some searching,not really finding much, then crossed my mind about me leaving the amp on all night, put the mullards in perfect, i'm puzzled ?? thoughts ?
   
  oh, there was no "new-set sparkle" like it said on the box


----------



## gibosi

Quote: 





jaywillin said:


> new tube arrived from a buy off ebay, the cbs hytron 6cs6,  plugged into the amp in the ef95 setting, loud constant hum
> changed amp to ef91 the same loud constant hum, bad tubes ? wrong setting, wrong tubes  ? i've been doing some searching,not really finding much, then crossed my mind about me leaving the amp on all night, put the mullards in perfect, i'm puzzled ?? thoughts ?
> 
> oh, there was no "new-set sparkle" like it said on the box


 
   
  They could be bad... However, in my experience, most noisy tubes quiet down after burnin. Check them every so often during burnin, and if they seem to be quieting down, they are good. If the noise is the same after 10 or so hours, then I would call them bad.
   
  Good luck!


----------



## jaywillin

Quote: 





gibosi said:


> They could be bad... However, in my experience, most noisy tubes quiet down after burnin. Check them every so often during burnin, and if they seem to be quieting down, they are good. If the noise is the same after 10 or so hours, then I would call them bad.
> 
> Good luck!


 

 after i posted, i wondered about that, its a pretty loud, steady, "electrical" hum
  thanks much !


----------



## foreign

jaywillin said:


> after i posted, i wondered about that, its a pretty loud, steady, "electrical" hum
> thanks much !



I'm getting the hytrons aswell in the next few days when they arrive ill let you know if I'm getting humming aswell.


----------



## jaywillin

Quote: 





foreign said:


> I'm getting the hytrons aswell in the next few days when they arrive ill let you know if I'm getting humming aswell.


 

 they are a'burnin as we speak ! or listen, or sit here, in other news, major equipment news, arrived yesterday, a set of grado ps500's
  today a meridian explorer, both from the sale thread !


----------



## gibosi

Siemens EK90 and EH90 Continued...
   
  In *post 2115 on page 141*, I concluded that my Siemens EK90 and the "foreign" Siemens EH90 were made in the same factory. (Unfortunately, we still have not found any evidence which tells us who actually manufactured these tubes or where.) 
   
  At that time, I had only one "foreign" Siemens EH90, and therefore, was unable to compare the sound of these two tubes. Recently, due to the generosity and kindness of Hynos1, I was able to obtain a second "foreign" Siemens EH90.
   
  While I expected the two Siemens to share a "house sound", I was initially quite surprised that I could not distinguish any difference in the sound of these two tubes unstrapped. But on second thought, perhaps it is not so surprising. After all, it may be that the only significant structural difference between these tubes is Grid 3: in the EK90, remote cut-off and in the EH90, sharp cut-off. Listening to these tubes in the unstrapped configuration, Grid 3 is disabled and thus these tubes would appear to be electronically identical. So for those of you who do not have a Siemens EK90 like mine, the "foreign" Siemens EH90 seems to be essentially the same tube, with the added bonus of sounding as good, or even better, strapped.
   
   I seem to recall that both MIKELAP and Mordy have reported this tube sounded best with 1-7 strapped. I should also note Acapella11's experience suggests that this tube might not be a good fit in rather bright systems. While I have not had time to critically listen to the various strappings, I can confirm that in casual listening, with 1-7 strapped, it sounds very good with my gear.
   
  Now some of you are probably thinking, "Who cares? Both of these tubes are almost impossible to find!!" But hey, I am not the kind of guy to leave you in a lurch! lol I have found another source for the "foreign" Siemens EH90. These are rebranded tubes, (ZaeriX - Z&I Aero Services LTD, London, England) so no Siemens logo, but they have identical construction, and more importantly, they sound identical to my ears. 
   
  http://www.ebay.com/itm/270288580465?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649

   

   

  In each pic, the Zaerix is on the left and the Siemens is on the right.
   

   

   

   

   

  Currently the vendor reports that more than 10 are available, so at least 5 pairs. Unfortunately, the cost exceeds our usual target of no more than $8.00/tube shipped. And further, the vendor is on vacation until August 22. But if you want a pair, you know where they are.


----------



## mordy

Hi Gibosi,
   
  Did u read the bottom of the ad? Are u holding on?
   
   
  [size=small][size=small][size=x-small][size=medium]*1 PIECE*[/size][/size][/size][/size]
  [size=small][size=small][size=x-small]*[size=x-large]EH90 6CS6 MINIWATT Z&I[/size]*[/size][/size][/size]
  [size=small][size=small][size=x-small]*[size=x-large]BELIEVE MADE IN U.S.A.[/size]*[/size][/size][/size]
   
  The plot thickens......


----------



## gibosi

Quote: 





mordy said:


> Hi Gibosi,
> 
> Did u read the bottom of the ad? Are u holding on?
> 
> ...


 
   
  Yes, I read that.... However, these don't look like any US-made tube I have ever seen. Moreover, I don't think I have ever seen a US-made tube with EK90 etched in the glass. So I still think these are "made-somewhere-in-Europe" tubes.


----------



## foreign

jaywillin said:


> they are a'burnin as we speak ! or listen, or sit here, in other news, major equipment news, arrived yesterday, a set of grado ps500's
> today a meridian explorer, both from the sale thread !



How do you find the Grados?


----------



## mordy

Hi G,
   
  Just thought it was funny. You are right, no US tube with EK90 on it. Here is another mystery tube 6BE6:
   
  http://www.ebay.com/itm/THE-FISHER-6BE6-VACUUM-TUBE-VERY-CLEAN-TESTED-GOOD-SEE-PHOTOS-Z-TJM-647-/251224516351?pt=Vintage_Electronics_R2&hash=item3a7e25e6ff





   
  This tube is made in West Germany but don't know by whom.


----------



## gibosi

Quote: 





mordy said:


> Hi G,
> 
> Just thought it was funny. You are right, no US tube with EK90 on it. Here is another mystery tube 6BE6:
> 
> ...


 
   
  The off-set holes suggest Telefunken:


----------



## frankie90

Hey guys, so I recently bought a MKIII off of eBay with some Voshkod tubes for my DT990 Pro and Sound Blaster Z. 
   
Now I am in a little bit of a pickle in regards to tube rolling the power tubes... it is a rev.2 board, so I am considering the Novosibirsk 6H6P-I and the Electro Harmonix 6H30Pi. Any suggestions for which might sound "better" for my DT990, and if there are any major discernible differences between the two. Only thing holding me back from the EH tubes is the $25 dollar price difference. 
   
I am also open to other suggestions for power tubes as well.
   
Thanks in advance.


----------



## Acapella11

Hi Frankie, if you go through the posts, and I would suggest to do that from page 50, you will find information to which power tubes are available, which year to choose and what people like. The information is more sparse than for driver tubes.
  In short: I wouldn't bother with 6N6P-I and 6N30P (=6H30P) or 6N30P-EV. My recommendation would be 6N6P-IR or 6N30P-DR if you feel generous . Buy both before 1984 because the quality of production changed thereafter.


----------



## jaywillin

the GE 6ce5/6bc6, not the best sounding tube i have, but it sure does glow !


----------



## frankie90

Quote: 





acapella11 said:


> Hi Frankie, if you go through the posts, and I would suggest to do that from page 50, you will find information to which power tubes are available, which year to choose and what people like. The information is more sparse than for driver tubes.
> In short: I wouldn't bother with 6N6P-I and 6N30P (=6H30P) or 6N30P-EV. My recommendation would be 6N6P-IR or 6N30P-DR if you feel generous . Buy both before 1984 because the quality of production changed thereafter.


 
  Hey man, thanks for your reply, I appreciate it. Well I definitely DO NOT have the time to read 600 pages of this thread, however I have been sporadically reading and that is where I came up with those two tubes... now you have me questioning my choice about the Voshkods, lol. 
   
  The 6N30P-DR is definitely out of my price range, especially considering I only paid $160 for the MKIII, I don't want to pay $120 for tubes. Any suggestions for 6N6P-IR brand of tubes? 
   
  EDIT: I am assuming these? http://www.ebay.com/itm/2-x-6N6P-IR-Russian-dual-triode-NOS-/161083192192?pt=LH_DefaultDomain_0&hash=item25814e7380 . Seems like a good deal to me, pretty cheap. Also, what about NOVOSIBIRSK 6N6P GOLD GRID, I read that they might sound "better" than the 6N6P-i's?
   
  As far as driver and power tubes go, bass is important to me, since I am a BASSHEAD, but more important is trying to deal with sillibance. Just an FYI


----------



## mab1376

Quote: 





jaywillin said:


> the GE 6ce5/6bc6, not the best sounding tube i have, but it sure does glow !


 
  The 6EW6 glow pretty bright too and sound really nice with the 2-7 strap.


----------



## frankie90

Quote: 





mab1376 said:


> The 6EW6 glow pretty bright too and sound really nice with the 2-7 strap.


 
  To be honest, I kind of want to stick to tubes that I just just plug in, with no modification. That's why I made sure I was purchasing a rev.2 board as well. I might look into this down the line for sure, but for now I just want to plug in a new one easily and start listening


----------



## mab1376

6BE6 variants then! what i'm running now unstrapped.


----------



## jaywillin

Quote: 





mab1376 said:


> The 6EW6 glow pretty bright too and sound really nice with the 2-7 strap.


 

 i haven't strapped yet, (said sheepishly) lol


----------



## kvtaco17

Quote: 





jaywillin said:


> i haven't strapped yet, (said sheepishly) lol


 

 Then you haven't lived!


----------



## frankie90

Quote: 





mab1376 said:


> 6BE6 variants then! what i'm running now unstrapped.


 
  Any particular brand to look at? I'm looking on eBay but theres a bunch, haha.
   
  I've been reading around but I don't recall reading about the 6BE6's...


----------



## Oskari

Quote: 





gibosi said:


> I have found another source for the "foreign" Siemens EH90. These are rebranded tubes, (ZaeriX - Z&I Aero Services LTD, London, England) so no Siemens logo, but they have identical construction, and more importantly, they sound identical to my ears.


 
   
  Actually the tube seems to be Miniwatt-branded (a Philips brand). Zaerix boxes are always full of surprises.


----------



## mab1376

Quote: 





frankie90 said:


> Any particular brand to look at? I'm looking on eBay but theres a bunch, haha.
> 
> I've been reading around but I don't recall reading about the 6BE6's...


 
   
  Siemens which is seemingly impossible to find now, telefunken and IBM are both good, alternate names are EK90 and 1680.


----------



## vic2vic

Hi all,
  I have a partial off-topic question, but still related to tubes for LD.
   
  As a owner of a LD MK2 unit, I "miss" (aesthetically) the nice brass rings which are fitted on the case at the bottom of the tubes in almost all other MK models (1+, MK3, MK6, MK7, MK8, MK9). Actually it seems ALL MK models have the nice rings, except the MK2 and MK4 (this one has a brass plate). 
	

	
	
		
		

		
		
	


	



   
  I'm looking for some of these brass rings on FleaBay or in online tube stores, but unfortunately I'm not able to find anything similar on sale. I found offers for new cases, new sockets, new protection grids, new capacitors ... but no rings 
	

	
	
		
		

		
		
	


	



  Has any of you any suggestions ?
   
  By the way, can you please also let me know how these rings are attached to your LD cases ? I guess they are glued to it, not screwed, correct ?
  Thanks


----------



## frankie90

Quote: 





mab1376 said:


> Siemens which is seemingly impossible to find now, telefunken and IBM are both good, alternate names are EK90 and 1680.


 
  I can't seem to find Siemens or Telefunken's on eBay... just so i'm straight, these power tubes require no modification, just plug-and-play, correct?
   
  Are they really that much better than 6N6P-IR, or 6H30Pi's? 
   
  I've been looking at http://www.ebay.com/itm/161083192192?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649, in comparison to the EH's and the 6H6P-I's. 1983 so they should still be good quality, I think.


----------



## Edgard Varese

Quote: 





frankie90 said:


> I can't seem to find Siemens or Telefunken's on eBay... just so i'm straight, these power tubes require no modification, just plug-and-play, correct?
> 
> Are they really that much better than 6N6P-IR, or 6H30Pi's?
> 
> I've been looking at http://www.ebay.com/itm/161083192192?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649, in comparison to the EH's and the 6H6P-I's. 1983 so they should still be good quality, I think.


 
  I think mab was referring to driver tubes, not power tubes (the EK90 is a driver tube).


----------



## frankie90

Quote: 





edgard varese said:


> I think mab was referring to driver tubes, not power tubes (the EK90 is a driver tube).


 
  Ohhhhhh, well I already have Voshkod 6ZH1P-EV as my driver tubes on the way, but I still have stock power so that why i'm looking to upgrade that.


----------



## kvtaco17

Got my Valvo EH90's today... got a little hum but that should go away with time. I also noticed the hum gets worse if I touch the tube when its on...

   

  My favorite Voskhod 6ZH1P-EV net to the new guy Valvo EH90


----------



## MIKELAP

Quote: 





vic2vic said:


> Hi all,
> I have a partial off-topic question, but still related to tubes for LD.
> 
> As a owner of a LD MK2 unit, I "miss" (aesthetically) the nice brass rings which are fitted on the case at the bottom of the tubes in almost all other MK models (1+, MK3, MK6, MK7, MK8, MK9). Actually it seems ALL MK models have the nice rings, except the MK2 and MK4 (this one has a brass plate).
> ...


 
  Try looking in hardware store for spacers  and they are not brass by the way  actually those rings are stainless steel and when heated by the tubes  turn yellowish a bit but if you want brass and you cant find spacers with the right sizes you can always go to a Machine Shop and have them turned 4 pieces on a lathe  use little silicon to glue them so they stay in place or just slip them on . Personnally i liked the little cages around the tubes so i made these with a hand drill and a dremel to cut the post the right lenght it was a pain to do but i like them


----------



## Edgard Varese

Quote: 





frankie90 said:


> Ohhhhhh, well I already have Voshkod 6ZH1P-EV as my driver tubes on the way, but I still have stock power so that why i'm looking to upgrade that.


 
  I'm cooking my Voskhods as I type...


----------



## MIKELAP

Quote: 





kvtaco17 said:


> Got my Valvo EH90's today... got a little hum but that should go away with time. I also noticed the hum gets worse if I touch the tube when its on...
> 
> 
> 
> My favorite Voskhod 6ZH1P-EV net to the new guy Valvo EH90


 
  Did you clean the pins before you put the tubes in sometimes it helps


----------



## frankie90

Quote: 





edgard varese said:


> I'm cooking my Voskhods as I type...


 
  I'm looking forward to them coming in the mail soon! What power tubes are you using, i'm still really undecided in that area...


----------



## Edgard Varese

Quote: 





frankie90 said:


> I'm looking forward to them coming in the mail soon! What power tubes are you using, i'm still really undecided in that area...


 
  I've got a Little Dot I+ so no power tubes to deal with.  All my headphones are low impedence (Grado & Alessandro), which don't match as well with the Mk III.


----------



## kvtaco17

Quote: 





mikelap said:


> Did you clean the pins before you put the tubes in sometimes it helps


 
   
   
  yes sir I did!


----------



## jaywillin

Quote: 





edgard varese said:


> I've got a Little Dot I+ so no power tubes to deal with.  All my headphones are low impedence (Grado & Alessandro), which don't match as well with the Mk III.


 

 i'm a grado/alessandro guy,
  ms2, and ps500


----------



## kvtaco17

I also saw...
   
  GE1
  B4k1
   
  GE1
  B4L2
   
  printed in shiny grey on them dates maybe?
   
  and proof of clean pins...


----------



## Edgard Varese

Quote: 





jaywillin said:


> i'm a grado/alessandro guy,
> ms2, and ps500


 
  MS1 and SR60 here, auditioning the RS1i, hopefully this week if the dealer can get them in for me.


----------



## jaywillin

Quote: 





edgard varese said:


> MS1 and SR60 here, auditioning the RS1i, hopefully this week if the dealer can get them in for me.


 

 you're lucky to have a dealer close by, i just have to take a chance, but, i haven't had a bad grado yet !!


----------



## MIKELAP

Quote: 





kvtaco17 said:


> I also saw...
> 
> GE1
> B4k1
> ...


 
  Heres a link regarding your codes  theres not much says GE means eh90 type http://www.triodeel.com/images/philipstubecodes.pdf      and this                  http://www.audiotubes.com/mullcode.htm


----------



## kvtaco17

Quote: 





mikelap said:


> Heres a link regarding your codes  theres not much says GE means eh90 type http://www.triodeel.com/images/philipstubecodes.pdf      and this                  http://www.audiotubes.com/mullcode.htm


 
  Thank you much! I saw that was posted awhile ago and was digging for it!
   
  Blackburn 1954 Aug/Sept week 1/2 is what I got out of that lol


----------



## mordy

Hi kvtaco 17,
   
  Not that it makes a difference, but it could be 1964 instead of 1954:
   
   
After 1956, the code changed to the following several formats, with the manufacture year (Y) kicking in to the mix: 
 TTC  FYM 
Another variation with the addition of the week of manufacture: 
TTC 
FYMW 
Another variation with a triple tube type number and the week: 
TTTC 
FYMW 
And to completely confuse you, yet another triple type number variation without the week: 
TTTC 
FYM
 The best way to become familiar with these variations on a theme is to get some vintage tubes and practice. For the most part, tubes made after 1956 are what is commonly found on the vintage market today. This will reduce the number of code choices you have, and the tube type codes of the tubes you use the most will become committed to memory.


----------



## kvtaco17

Quote: 





mordy said:


> Hi kvtaco 17,
> 
> Not that it makes a difference, but it could be 1964 instead of 1954:
> 
> ...
 
  very true! I'll continue living me lie lol
   
  Anyways, the hum has almost completely gone away, however they so make some noise when touched... the right channel a lot more then the left... I tried swapping tubes and the phenomenon follows the tube... however they sound fine...


----------



## mordy

Been thinking about the "mystery" tubes where we do not know who made them (yet).
   
  Did you ever hear of a company called Johnson Controls? Probably not. Well, this is what they do:
   

 World’s largest manufacturer of lead acid automotive batteries for virtually every type of passenger car, light truck and utility vehicle.
 
 Lead acid batteries sold under private label brands as well as our own VARTA®, Heliar®, LTH® and OPTIMA® brand names. Major OEMs and aftermarket retailers include Daimler, General Motors, BMW, Ford, Toyota, Hyundai, Kia, Volkswagen, SAIC, Bosch, Walmart, Halfords, Interstate Battery System of America, Advance Auto Parts, and AutoZone.
   
  In other words, they manufacture automotive batteries for almost all major brands of cars worldwide.
   
  Seems that they prefer to be anonymous. You may think that you have a Ford, AC-Delco, Walmart, Interstate or AutoZone battery, but they are all made by the same corporation. (I am sure that they are made to different specifications etc.)
   
  Now, translating this concept to tubes, which factory in  the past seems most likely to make very high quality tubes, and mainly for others (and very few with their own name on them)?
   
  My hunch is that it is Ei (Elektronska Industrija) in Yugoslavia. Originally they purchased Phillips machines and later Telefunken machines. The original licencing from Phillips started in 1959.
   
  In a documentary of Ei (Youtube) the narrator says that they make tubes for many brands, including Phillips, Siemens and Telefunken. (54 sec mark,   http://www.youtube.com/watch?v=fxXrfU36aY8)
   
  I seem to remember from the clips that maximum production was 17 million tubes per year.
   
   
   
  Your thoughts and comments are invited......


----------



## kvtaco17

Johnson Controls also does switch and building maintains lol
   
  I work with and round their techs a lot doing DC power and switch/data center (telecom mostly) work.
   
  I think you may be on to something!


----------



## frankie90

Well, I went ahead and pulled the trigger on some 1983 Novosibirsk 6N6P-IR's over the 6H30Pi's for my MKIII, mainly because of price. I think they should pair well with my Voskhod 6ZH1P-EV's and my DT990, hopefully I like them! 
   
Now for the wait...


----------



## Oskari

Quote: 





kvtaco17 said:


> GE1
> B4k1
> 
> GE1
> B4L2


 
   
  Quote: 





mikelap said:


> Heres a link regarding your codes  theres not much says GE means eh90 type http://www.triodeel.com/images/philipstubecodes.pdf and this http://www.audiotubes.com/mullcode.htm


 
   
  Additional links:
   

 http://frank.pocnet.net/other/Philips/PhilipsCodeListAB-v10.pdf
 http://frank.pocnet.net/other/Philips/PhilipsCodeList.pdf
   
  Quote: 





kvtaco17 said:


> Blackburn 1954 Aug/Sept week 1/2 is what I got out of that lol


 
   
  Quote: 





mordy said:


> Not that it makes a difference, but it could be 1964 instead of 1954:


 
   
  True. With four-character second lines those are not 1954 tubes. The date codes tell that they must be 1964 or 1974 tubes (maybe even 1984 tubes, if they still made them).


----------



## mordy

Hi Frankie90,
   
  Just got those exact tubes - took 18 days. As a comparison, I got a pair from Germany, which took 14 days. YMMV
   
  (You have to sign for the  Russian tubes BTW)


----------



## jaywillin

Quote: 





mordy said:


> Hi Frankie90,
> 
> Just got those exact tubes - took 18 days. As a comparison, I got a pair from Germany, which took 14 days. YMMV
> 
> (You have to sign for the  Russian tubes BTW)


 

 in disappearing ink ?


----------



## Acapella11

Quote: 





frankie90 said:


> Well, I went ahead and pulled the trigger on some 1983 Novosibirsk 6N6P-IR's over the 6H30Pi's for my MKIII, mainly because of price. I think they should pair well with my Voskhod 6ZH1P-EV's and my DT990, hopefully I like them!
> 
> Now for the wait...


 
   
  Congratulations. Mine are from the old Novosibirsk factory indicated by a pentagon in between month and year of production (1974). Besides other sound benefits, this tube also extends to a deeper bass as compared to 6H30P / 6N6P or 6N6P-I tubes.  With respect to the driver tube, I second mab's recommendations. When you feel like like an upgrade for the upgrade, get some of the IBM 1680 6BE6 tubes from 1950 as long as they are available, particularly if your fancy goes to a good bass. Imaging is very nice as well.


----------



## gibosi

Quote: 





mordy said:


> Now, translating this concept to tubes, which factory in  the past seems most likely to make very high quality tubes, and mainly for others (and very few with their own name on them)?
> 
> My hunch is that it is Ei (Elektronska Industrija) in Yugoslavia. Originally they purchased Phillips machines and later Telefunken machines. The original licencing from Phillips started in 1959.
> 
> ...


 
   
  Mordy,
   
  Ei is certainly a very likely possibility. Whoever made these tubes did indeed seem to want to be anonymous, as there are no unique markings or codes of any kind indicating who manufactured them or their country of origin. With their location in Europe and a production capacity of 17 million tubes per year they were certainly more than capable. We may never know who who made these "foreign" Siemens, but I think this is the best guess we have.
   
  However, I have one more mystery Siemens. The tube on the left compared to the "Ei" Siemens on the right:
   
  Thicker ribs, holes in plate different, shape of getter is different, a much darker getter flash, and other than "Siemens #201", no marks or codes. As I have only the one tube, I am still trying to find a match....


----------



## mab1376

Quote: 





acapella11 said:


> Congratulations. Mine are from the old Novosibirsk factory indicated by a pentagon in between month and year of production (1974). Besides other sound benefits, this tube also extends to a deeper bass as compared to 6H30P / 6N6P or 6N6P-I tubes.  With respect to the driver tube, I second mab's recommendations. When you feel like like an upgrade for the upgrade, get some of the IBM 1680 6BE6 tubes from 1950 as long as they are available, particularly if your fancy goes to a good bass. Imaging is very nice as well.


 
  Mine are from 11(pentagon)89, I ordered another from 1974 about a week ago i'm waiting on from ebay.
   
  Even the ones from 89 sound really nice to me, i'll compare when I get the new ones.


----------



## frankie90

acapella11 said:


> Congratulations. Mine are from the old Novosibirsk factory indicated by a pentagon in between month and year of production (1974). Besides other sound benefits, this tube also extends to a deeper bass as compared to 6H30P / 6N6P or 6N6P-I tubes.  With respect to the driver tube, I second mab's recommendations. When you feel like like an upgrade for the upgrade, get some of the IBM 1680 6BE6 tubes from 1950 as long as they are available, particularly if your fancy goes to a good bass. Imaging is very nice as well.



Thanks everyone! Yeah I'm excited at this is my first tube amp...

Are those IBMs driver tubes? I just got Voskhods, are they better than those overall?


----------



## gibosi

Another mystery tube....
   
  RSD EH90. I have no idea who made these....
   
http://www.ebay.com/itm/Rohre-EH90-EH-90-6CS6-RSD-Tube-gepruft-NOS-/310264285657?pt=DE_TV_Video_Audio_Elektronenr%C3%B6hren_Valves&hash=item483d3149d9


----------



## mordy

Hi Gibosi,
   
  You will not get the answer from this, but you will know more:
   
  "RSD like ULTRON was a German relabeler.

 In early days, RSD label tubes came from fine German sources like Telefunken, Siemens etc. or other British/W. European makers.

 Later on, RSD was relabeling tubes from Eastern or Central Europe."


----------



## mordy

Hi jaywillin,
   
  "in disappearing ink ?"
   
  I put that in, because someone on the forum always seems to be out when the mailman comes, and then he has to go to the post office the next day. So if you can, and you anticipate that the tubes are going to arrive a certain day, try to be around when the man comes - who wants to wait another day?


----------



## gibosi

Lorenz EH90
   
  After spending some time with these, to my ears they sound essentially the same as my Ulm-manufactured Telefunken EH90. The Lorenz do have the Telefunken diamond impressed between the pins, but it is not as clean and precise looking as on my Ulm Telefunkens. The plates with the vertical line of spot welds also looks much less polished and "professional" than the Telefunkens. Moreover, the glass envelope and getter splash are also different. However, the solder-work connecting the pins to the electrodes and the lower mica seem to be essentially identical. And the coup de grace is the sound. These have the the Telefunken sound, very clean and quite bright.
   
  A fellow-headfier insists, "If it has the Telefunken diamond, it must be a Telefunken!" And at least in this case, he was right.


----------



## kvtaco17

Scooped up a pair of Svetlana 6A2P's for cheap, they will be a while before they get here BUT I'll report back with results... Same withe the Ediswans EH90's I ordered.
   
  In other news the Valvo EH90's were given a good 10 hours under load (breaking in some new sr225i drivers for a friends build) and the hum is gone, they no longer sound congested, everything is much better! EXCEPT the 1 tube still hums if I touch it. No biggie though, just gotta keep my hands off the sexiness...


----------



## jaywillin

Quote: 





mordy said:


> Hi jaywillin,
> 
> "in disappearing ink ?"
> 
> I put that in, because someone on the forum always seems to be out when the mailman comes, and then he has to go to the post office the next day. So if you can, and you anticipate that the tubes are going to arrive a certain day, try to be around when the man comes - who wants to wait another day?


 

 feeble attempt at some cold war spy humor , i understand believe me !
  i had my wife, who is not very mobile at the present, (some serious shoulder surgery) ask, though somewhat sheepishly, if she could possibly get up if the mail came so she could sign for my ps500's which were coming insured, she did, she's a trooper


----------



## gibosi

Quote: 





kvtaco17 said:


> In other news the Valvo EH90's were given a good 10 hours under load (breaking in some new sr225i drivers for a friends build) and the hum is gone, they no longer sound congested, everything is much better! EXCEPT the 1 tube still hums if I touch it. No biggie though, just gotta keep my hands off the sexiness...


 
   
  Fortunately for those of us who use headphone amps, microphonics is really not much of a problem. Of course, it bums me out a little, but since I listen in a very quiet room, I never notice it at all unless I start tapping on the table.


----------



## MIKELAP

Quote: 





mordy said:


> Hi jaywillin,
> 
> "in disappearing ink ?"
> 
> I put that in, because someone on the forum always seems to be out when the mailman comes, and then he has to go to the post office the next day. So if you can, and you anticipate that the tubes are going to arrive a certain day, try to be around when the man comes - who wants to wait another day?


 
  Ya mordy thats me  and the worst thing is that i follow that tracking number  like a hawk but theres always an appointment mostly medical you know how it is mordy that makes me get out when the postmam comes knockin. like this week im expecting gibosi 6AV6 westinghouse,  i mean my westinghouse lol but this package  i dont have to sign for. Right now enjoying my newly aquired Pionneer SX750  from 1977-1978 in very good   condition sounds surprisingly good with the Senns hd800 i had heard that from the vintage thread that they where a good match and its true


----------



## mordy

Hi Mikelap,
   
  Don't know how it works in your neighborhood (if it is safe to leave a package outside), but what I do when I am not home and know a package is going to arrive that I have to sign for, I print out the delivery information and sign it. Then I tape the paper to the front door. This usually works for UPS and FedEx - not so sure about the post office though.
  
  BTW, I have a 1974 Onkyo T9 tuner that's pretty good, but I rarely use it.


----------



## MIKELAP

Quote: 





mordy said:


> Hi Mikelap,
> 
> Don't know how it works in your neighborhood (if it is safe to leave a package outside), but what I do when I am not home and know a package is going to arrive that I have to sign for, I print out the delivery information and sign it. Then I tape the paper to the front door. This usually works for UPS and FedEx - not so sure about the post office though.
> 
> BTW, I have a 1974 Onkyo T9 tuner that's pretty good, but I rarely use it.


 
  I live in a appartment complex so i wouldnt take a chance even if the building is safe theres no rush anyways i have several pairs that i didnt burnin yet that i received from a while back im behind wheather so nice these days gotta go out . back then i had an English Quad 100 watt rms per channel use to drive my friends Altec A-7 got that thing in 1977gave it to my son with all my records .Wasnt so hot with Pionneer and all those brands back then tough it was crap actually lol yes Acapella11 the English make damm good gear i gotta say my main amp is Australian close enough .lol


----------



## Edgard Varese

Quote: 





frankie90 said:


> Thanks everyone! Yeah I'm excited at this is my first tube amp...
> 
> Are those IBMs driver tubes? I just got Voskhods, are they better than those overall?


 

 The IBMs are driver tubes also, I haven't heard them but they seem to have been reviewed positively upthread...


----------



## vic2vic

Quote: 





mikelap said:


> Try looking in hardware store for spacers  and they are not brass by the way  actually those rings are stainless steel and when heated by the tubes  turn yellowish a bit


 
   
  Thanks MIKELAP for the good idea of spacers, I'll try to look for some of them. Now I just need to figure out the right size, as I can not find my caliper anymore (I guess all 4 rings are the same size, correct ?).


----------



## britt2001b

Hey Mikelap,
   
  Great find on your Pioneer SX 750. I recently found a SX 580 in great condition at a thrift shop. The Pioneer receivers from the 70's sound wonderful. Got it sitting right next to my Little Dot MK III.


----------



## MIKELAP

Quote: 





vic2vic said:


> Thanks MIKELAP for the good idea of spacers, I'll try to look for some of them. Now I just need to figure out the right size, as I can not find my caliper anymore (I guess all 4 rings are the same size, correct ?).


 
  No power tube rings are bigger I took the liberty of making a drawing of the power tube rings and of the driver tube rings


----------



## vic2vic

Quote: 





mikelap said:


> I took the liberty of making a drawing of the power tube rings and of the driver tube rings


 
   
  Thanks a lot again ! This picture will definitely help me out in looking for the right rings.


----------



## MIKELAP

Quote: 





britt2001b said:


> Hey Mikelap,
> 
> Great find on your Pioneer SX 750. I recently found a SX 580 in great condition at a thrift shop. The Pioneer receivers from the 70's sound wonderful. Got it sitting right next to my Little Dot MK III.


 
  Nice amp ,unfortunatly i am going to have to make some room right now i got 2 amp on my desk and the Pioneer on my left side. the pioneer  sounds nice with Senns very happy didnt expect it would sound that good.


----------



## Advil

Hey I have an old Little Dot II++ and I just realized that the two bigger (power?) tubes in the back are different than each other. The driver tubes are Mullard 161's but I need to either match or get a new set of power tubes. Anyone got a link to what I should get? Thank you!


----------



## mordy

gibosi said:


> After about 28 hours, these Tung Sol 6TD6 are some seriously good tubes. Going by memory, they remind me of the Tung-Sol 6485, with great bass, effortless treble detail and clear vocals that seem to be etched in space. I need to spend some time directly comparing them with the 6485, and further, since these can be strapped 1-7, I feel strongly that I should try them in that configuration too.... Thinking about how that might sound is very intriguing.....


   
  Dedicated to all bargain finders and sonic thrill seekers on this forum:
   
   
  Bought a pair of 6DT6 RCA {hereafter called dtox}  tubes very cheap ($4.40 incl shipping.)  After some 20 hours on EF95 1/7 setting, they sound exactly as described above, with another addition:  an e x t r e m e l y  W - I - D- E  sound stage. Wow! They even beat the current sound stage champion Sylvania.
   
  These tubes are plentiful and cheap, and are highly recommended.  A top tier tube for a song. -No need to scrounge around for them furrin Siemens/Valvo/Zaerix/Lorenz high prized and difficult to find tubes!
   
  Go dtox!
   
  Would like to hear from others how u find these tubes......


----------



## gibosi

Quote: 





> Originally Posted by *mordy* /img/forum/go_quote.gif
> 
> Bought a pair of 6DT6 RCA {hereafter called dtox}  tubes very cheap ($4.40 incl shipping.)  After some 20 hours on EF95 1/7 setting, they sound exactly as described above, with another addition:  an e x t r e m e l y  W - I - D- E  sound stage. Wow! They even beat the current sound stage champion Sylvania.
> 
> These tubes are plentiful and cheap, and are highly recommended.  A top tier tube for a song. -No need to scrounge around for them furrin Siemens/Valvo/Zaerix/Lorenz high prized and difficult to find tubes!


 
   
  I'm glad to see that I am not entirely alone in checking out these 6HZ6 and 6DT6 tubes, or "herz and dtox" if you will. lol  I think these are a steal for the price. While I have been massively sidetracked by Siemens/Zaerix/Lorenz/Telefunken EH90 recently, I still have a pair of RCA 6HZ6 that I need to burn in. And as the RCA 6HZ6 should sound identical to yours (except perhaps a bit louder), I have decided to move them to the front of the burn-in line, ahead of the Fivre and Multivox (Japan) triodes.
   
  Will get them started as soon as I post this!
   
  Edit: Oops! One of them is dead!!   Will contact the vendor.... and search for another pair.....


----------



## Acapella11

Siemens EH90 "Foreign"
  
 OK, finally here are my compliments for this tube. For this it needed a different DAC though. Introduction: Recently, I acquired cheaply the Yamaha HDD/CD-recorder CDR-HD1300. One of the features is a 24 Bit / 96 kHz D/A converter, which can be used in DAC mode. Hooking it up to the LD with the IBM 1680 tubes didn't really make me happy. Sounded a bit blurred, a bit too much bass. 2/7-strap was the solution for this tube. Much better focus and really easy lo listen to signature. In contrast to the sharp and slightly hard Audiolab M-DAC, this DAC is rather warm and imaging is thicker. So, for the Yamaha 2/7 works well, for the Audiolab unstrapped sounds great. Then come the Siemens EH90 "Foreign" 1/7-strap (1/7 is better 2/7 and NS). Imaging became sharper, sound overall crisper as you can expect form these tubes. They almost act as a focusing lens. The bass is more articulate as well. These tubes sounded "cleaner" than the IBM.  The overall tonality is nice with very good focus. Actually, a good match altogether. On a side note, the Yamaha output volume is unfortunately too low to support the output feed, which increases the distortion a little and decreases openness.
  
 Comparing them to the Siemens EK90 "Black Bottom" shows that the 1/7 "Foreign" is more equal to the Siemens than with the Audiolab M-DAC. Still, I prefer the Siemens. there is something round in mids and treble that I just like and the Siemens do provide a bit more bass and do not sound as forward as well.
  
 Well, the lesson learned is that it really all depends on system matching. Another nice side information of course is that it is amazing how flexible you can be with a tube amp if you have loads options as with the LD.
  
  Quote: 





mikelap said:


> Ya mordy thats me  and the worst thing is that i follow that tracking number  like a hawk but theres always an appointment mostly medical you know how it is mordy that makes me get out when the postmam comes knockin. like this week im expecting gibosi 6AV6 westinghouse,  i mean my westinghouse lol but this package  i dont have to sign for. Right now enjoying my newly aquired Pionneer SX750  from 1977-1978 in very good   condition sounds surprisingly good with the Senns hd800 i had heard that from the vintage thread that they where a good match and its true


 
   
  It looks like a very nice setupe Mikelap!
   
  But oh no, don't tempt me to buy an Pioneer amp!
  On the other hand, maybe...  If you feel like it, send me a pm with impressions you got. We don't want to turn this into a Pioneer thread, lol.
   
  Quote: 





mordy said:


> gibosi said:
> 
> 
> > After about 28 hours, these Tung Sol 6TD6 are some seriously good tubes. Going by memory, they remind me of the Tung-Sol 6485, with great bass, effortless treble detail and clear vocals that seem to be etched in space. I need to spend some time directly comparing them with the 6485, and further, since these can be strapped 1-7, I feel strongly that I should try them in that configuration too.... Thinking about how that might sound is very intriguing.....
> ...


 
   
  You guys. dtox. I love it. OK..., seems one more tube on the list =)


----------



## loose

What is ef95 1/7 setting?


----------



## gibosi

Quote: 





loose said:


> What is ef95 1/7 setting?


 
   
  You configure your amp to play EF95 tubes. And then you physically strap pins 1 and 7 together in the socket. Check out page 77 for more info on how to use the various tubes you see mentioned in this forum, as well as an explanation, with pictures, of how to "strap pins in the socket."


----------



## mab1376

If no one has tried the IBM 1680 with 2-7, give it a go, little less bass but overall much better IMO.


----------



## kvtaco17

Quote: 





gibosi said:


> I'm glad to see that I am not entirely alone in checking out these 6HZ6 and 6DT6 tubes, or "herz and dtox" if you will. lol  I think these are a steal for the price. While I have been massively sidetracked by Siemens/Zaerix/Lorenz/Telefunken EH90 recently, I still have a pair of RCA 6HZ6 that I need to burn in. And as the RCA 6HZ6 should sound identical to yours (except perhaps a bit louder), I have decided to move them to the front of the burn-in line, ahead of the Fivre and Multivox (Japan) triodes.
> 
> Will get them started as soon as I post this!
> 
> Edit: Oops! One of them is dead!!   Will contact the vendor.... and search for another pair.....


 
   
  Quote: 





mordy said:


> gibosi said:
> 
> 
> > After about 28 hours, these Tung Sol 6TD6 are some seriously good tubes. Going by memory, they remind me of the Tung-Sol 6485, with great bass, effortless treble detail and clear vocals that seem to be etched in space. I need to spend some time directly comparing them with the 6485, and further, since these can be strapped 1-7, I feel strongly that I should try them in that configuration too.... Thinking about how that might sound is very intriguing.....
> ...


 
   
  Scooped the RCA's... I'm excited!


----------



## jaywillin

the  cbs hytron 6cs6 i got last week, noise never went away, the seller is sending another pair no charge, very eager to please !
   
  and i'm really starting to think its time to stap a tube !


----------



## Advil

Regarding my last post: this is all i've found online, how good/bad are these? http://www.thetubestore.com/Tubes/Russian-Tubes/Russian-6C19p
   
  I found the same ones on eBay for way cheaper I think http://www.ebay.com/itm/6S19P-Russian-NOS-MATCHED-PAIR-TUBES-/310133057271?pt=Vintage_Electronics_R2&hash=item48355ee6f7
   
  And will my Little Dot II++ do well driving q701?
   
  Thanks


----------



## mordy

Hi mab 1376,
  
  here is post #2078 p. 139 (happy to see that you agree with the reviewer):
   
   Hi All,
   
  Here is a review of the IBM 1680 (6BE6) tube made by Sylvania: (please read until end or skip to summary)
   
  EF95 1/7 Strap setting (used for burn in): The first impression was the signature heptode sound of wide expansive sound stage, clarity and abundant detail. Then some shortcomings became apparent: soft flabby bass, cool mid range, lack of dynamics, and sibilant treble.
   
_These deficiencies disappeared slowly, and after significant burn in they almost all disappeared to a certain extent._ After being burnt in for 50-60 hours the tubes had improved markedly. The bass is acceptable but lacks slam and attack. The mid range became warmer. The highs are still sibilant and sharp. Good bye (and good riddance) EF95 1/7 setting.
   
  EF95 NS (no strap): This setting yields better sound than the one previously described. Firmer, more distinct bass, mid range regular warm, highs still sharp but no sibilance, good detail. Yep, much better, but no wow factor. A certain lack of micro dynamics, rhythm and pacing. A good simulation of my solid state receiver with better bass. Bye Bye EF95 NS.
   
EF95 2/7 strap: Wow! Multi layered 3D heptode magic! Bold, powerful bass, full of details and micro dynamics, great highs. Involuntarily toe tapping - a 4 on a scale of 5.
Cons: Bass does not go down to the deepest levels, and there is a minor mid range coolness and hollowness.
Very good presentation overall with tons of detail and musicality. EF95 2/7 - you are welcome any time.
   
  EF92 setting (using EF95 6/7 strap setting): Treble excellent with great detail and power but some sibilance; mid range good, bass is a bit boomy. Overall quite good, grows on you. Perhaps this setting would match certain types of equipment.  EF92 - nice to see you, bye.
   
   
  SUMMARY OF THE IBM 1680 TUBE:
  As mentioned before, the differences between heptodes are much more subtle than between 6AK5 tubes, and thus harder to describe.
  Using the EF95 2/7 strap setting this tube is very good performer, albeit not on the level of the very best heptodes.
   
  The EF92 setting may be a good choice if you like a very detailed treble presentation.
   
  EF95 NS is OK. 
   
  EF95 1/7 is not recommended.
   
  Price wise, the 1680 is a winner with a cost of less than $8 for a pair shipped.
   
  As they say in a prominent consumer magazine: Recommended, Best Buy.
   
  Edit 7/27/13: Listening to the EF92 simulated setting now. Don't know if the tubes stabilized or my perception changed, but these tubes sound excellent now on this setting. Bass is firm but not in your face, almost no sibilance. Detail, detail. Simply beautiful.


----------



## mab1376

Quote: 





mordy said:


> Hi mab 1376,
> 
> here is post #2078 p. 139 (happy to see that you agree with the reviewer):
> 
> ...


 
  This is becoming my favorite combo, curious to see if my new 6N6P-IR from '74 improve on this. Current is from '89.


----------



## mordy

Hi All,
   
  Since the material on this site is chock full of facts and excellent information, pioneering research, and wonderful civility and patient helpfulness, it may be a bit overwhelming to remember everything. I am little embarrassed  to say that I only recently discovered a search function that is available, It's not Google territory, but still useful.
   
  On the top portion of the page, right above the line with the page numbers, there is a field :
   
1 Unread Post Subscribed Search This Thread Preferences
   
  Click Search This Thread
   
  Another field opens up: Search for posts in this thread
   
  Here you can type in whatever you want; let's say 6HZ6. After you do this, click on search, then another two choices: Relevance or Recency.
   
  I found Recency more useful; it lists posts mentioning 6HZ6 (or whatever you typed in) in order from the newest to the oldest post.
   
  Something else that took a while for me to understand: The line with the pages has a space with dots. If you click on this, a slider appears that you can move to the page you are looking for. Then click go and you are on the page you want so you don't have to click through every page to get there.
   

 « Previous
 1
 …
 159
 160
 161
 162
 163
 164
 165
 166
 167
   
   
  1 
  Jump to page
   
  If I have bored people with my rudimentary computer knowledge I apologize. However, maybe somebody will find this information useful.


----------



## gibosi

Quote: 





gibosi said:


> However, I am preparing to roll several different op amps (LME49720HA, LME49990, and LT1028 in case anyone is interested) that are considered more neutral than the OPA2107. It will be interesting to see how this changes my opinion of the 4 tubes we have in common.


 
   
  A pair of LME49990 opamps arrived yesterday and rolled them in my 1+. First impressions, I believe they are a significant improvement over the OPA2107. And I am not all that surprised. I figured that if they are good enough for the Parasound Halo CD 1, they just might be good enough for my 1+. lol
   
  And now I am happily getting reacquainted with all my favorite tubes and tunes.


----------



## jaywillin

Quote: 





mordy said:


> Hi All,
> 
> Since the material on this site is chock full of facts and excellent information, pioneering research, and wonderful civility and patient helpfulness, it may be a bit overwhelming to remember everything. I am little embarrassed  to say that I only recently discovered a search function that is available, It's not Google territory, but still useful.
> 
> ...


 

 lol, i myself just the other day, discovered the "search this thread" function and used it regarding strapping/socket modding etc. found page 59, in addition to 77-79
  tomorrow, a schiit lyr is due here, and i'm going to have to sell of of my dacs, and probably 2 of the 3 amps i have
  to help defray some of the costs
  i in no way feel the ld 1+ lacking, i love it, i may turn right around and sell the lyr
  but before either of these two amps departs, i'm gonna give the strapping a try


----------



## mab1376

FYI Koray from http://www.nostubestore.com/ said he just got a huge shipment of tubes and is looking for some EH90's for me as he's sorting through them.


----------



## siles1991

Guys just did some digging around and found some tubes on ebay wondering if it's possible to use them. The 6AN5 and the HY90


----------



## Acapella11

Quote: 





mordy said:


> Hi mab 1376,
> 
> here is post #2078 p. 139 (happy to see that you agree with the reviewer):
> 
> ...


 
   
  Quote: 





acapella11 said:


> Siemens EH90 "Foreign"
> 
> OK, finally here are my compliments for this tube. For this it needed a different DAC though. Introduction: Recently, I acquired cheaply the Yamaha HDD/CD-recorder CDR-HD1300. One of the features is a 24 Bit / 96 kHz D/A converter, which can be used in DAC mode. Hooking it up to the LD with the IBM 1680 tubes didn't really make me happy. Sounded a bit blurred, a bit too much bass. 2/7-strap was the solution for this tube. Much better focus and really easy lo listen to signature. In contrast to the sharp and slightly hard Audiolab M-DAC, this DAC is rather warm and imaging is thicker. So, for the Yamaha 2/7 works well, for the Audiolab unstrapped sounds great. Then come the Siemens EH90 "Foreign" 1/7-strap (1/7 is better 2/7 and NS). Imaging became sharper, sound overall crisper as you can expect form these tubes. They almost act as a focusing lens. The bass is more articulate as well. These tubes sounded "cleaner" than the IBM.  The overall tonality is nice with very good focus. Actually, a good match altogether. On a side note, the Yamaha output volume is unfortunately too low to support the output feed, which increases the distortion a little and decreases openness. 
   
  Quote: 





mab1376 said:


> If no one has tried the IBM 1680 with 2-7, give it a go, little less bass but overall much better IMO.


 
   
  OK, nice one. Seems we agree on this,  at least certainly when I use the Yamaha HD1300.
  Unfortunately, I have not tried 1/7 and 2/7 with the IBM 1680 on the M-DAC. Unstrapped just sounded good, hence I haven't commented on it yet. I will definitely check this out on the M-DAC as well. The IBM 1680s anyway have earned their individual review (using my regular DAC as well), so more on this later.
   
  Second topic - Black Bottom 6A2P:
   
 Well, there is good (2) and bad (1) news. First one good news: The tubes arrived safely. Secondly, the bad news: They are not Svetlana Black Bottom tubes from 1979! Instead, 9 out of 10 are white bottom October tubes from 1983 with slightly broader ribboning. On the other hand, they are more like "proper" Siemens as they also have a numeric digit printed in the bottom. Also interestingly, both share certain marks on the plates, which makes me think that they share a similar way of production. These obviously do not exactly sound like the black bottom tubes.
 Now, the second good news is that they at least sound good. My first impressions are that they sound like a dryer version of the Siemens with very good focus. Quickly tested 1/7 and 2/7 as well, and I think I like 1/7, which adds some ambient, quite good really. No verdict yet.  Surely I enjoy them at them moment, at least that´s fine. =)  
 I have written the seller. Let's see what he says.


----------



## gibosi

Quote: 





siles1991 said:


> Guys just did some digging around and found some tubes on ebay wondering if it's possible to use them. The 6AN5 and the HY90


 
   
  The HY90 is a rectifier, so no go. It was designed to be used in power supplies. The 6AN5 should work fine in the EF95 setting with no strapping required. To my knowledge no one has tried to these yet....


----------



## MIKELAP

Quote: 





mordy said:


> Hi All,
> 
> Since the material on this site is chock full of facts and excellent information, pioneering research, and wonderful civility and patient helpfulness, it may be a bit overwhelming to remember everything. I am little embarrassed  to say that I only recently discovered a search function that is available, It's not Google territory, but still useful.
> 
> ...


 
  I did not know that either i was  always looking at a ton of pages to find something and i was wondering why there wasnt a faster way to do this .Thanks mordy my eyes thank you and the headache i wont  get also !


----------



## Edgard Varese

I'm starting to think one of you strapping advocates could make a little money selling straps to those of us who are DIY challenged...


----------



## mordy

Hi Edgard V,
   
  I was also among those DIY challenged, but it really is very easy. What you want to do is to make what looks like a staple, but a staple with insulation in the middle part.
   
  You MUST use stranded very thin wire, not solid core. The wire from the ear buds your mother drove over with the car will do. Another good source is a standard modular telephone wire with the clips at each end. I must have two-three dozen of those wires from all the phones that broke over the years.
   
  Take a scissors, knife or whatever and cut the plastic sheathing around the wires. Then separate out the wires, black, red, yellow, white etc. Cut off a piece a couple of inches long. Then take a paper and mark off 20mm and 17 mm lengths. Line up the wire and cut it off 20mm and 17 mm long. You need two of each. A scissors will do here, or cutting pliers etc.
   
  Then strip 3-4 mm off each end. You really don't need more than that. The best is to use a wire stripper set for the thickness of the wire to avoid cutting off some of the strands. However, if you are careful you can use the scissors, cutting pliers etc (or your teeth? No, not at my age. More on age later...).
   
  Now you twirl each end so that the wires stay together and don't open up in every direction. Then just bend each end to make it look like a staple. Voila, you are done! *Now look at page 77:* Look at the pictures at the bottom.
   
  The 20 mm piece is for the 2/7 strap, the 17 mm is for the 1/7 strap. By slightly curving the middle piece you make the middle a tad shorter, and then you can use the 17mm for the 6/7 strap, which will save you from switching the jumpers underneath to the EF92 setting.
   
  For me the easiest way to put in the straps is with a precision tweezers. If the straps are the right size, they just drop in. If your fingers have good dexterity, you don't need any tools. Many times you need to give a little push with your finger tip to put the strap in the right place.
   
  It is very common for the strap to move out of position when changing tubes, and many times you have to take out the strap and twirl the wires together again as well as straightening out the shape of the strap. Sometimes the straps behave and stay in place - I found that the very softest wire was harder to work with; a little stiffer is better.
   
  Now which color wire works the best? Black. Why? At my age I have trouble making out a white wire on the white tube socket; even yellow is a bit hard to see. And when I drop a strap on the floor I can't find it right away many times.... So practice and make a few backups.
   
  All suggestions on how to improve on making straps (and critique) are welcome.
   
  Have fun!
  
  PS: No need to pay for the straps, not hard to do, and I am sure you have the materials sitting around.


----------



## TrollDragon

Nice tip mordy!
Very instructional, I'll have to make up a few for when my 6BE6's finally get here. Canada post distributes all mail by dog sled team's in Nunavut.

One could possibly solder up a set of external switches to the socket tangs for rolling purposes.

I'd like to drill out the rivet in the tube sockets and install some nice LED's, but I know once you took that rivet out the socket would fall apart... Which would keep the garish factor down as well I suppose not adding LED's


----------



## Edgard Varese

Quote: 





mordy said:


> Hi Edgard V,
> 
> I was also among those DIY challenged, but it really is very easy. What you want to do is to make what looks like a staple, but a staple with insulation in the middle part.
> 
> ...


 
   
  That is indeed very helpful Mordy, thank you.   I'm just hoping my fading eyesight (rapidly increasing presbyopia) will allow me to do this without the use of a 150 watt halogen bulb.


----------



## jaywillin

Quote: 





mordy said:


> Hi Edgard V,
> 
> I was also among those DIY challenged, but it really is very easy. What you want to do is to make what looks like a staple, but a staple with insulation in the middle part.
> 
> ...


 

 indeed mordy thanks, yesterday i spent some time studying 77-79, and page 59 regarding this subject, i'm not sure why, but i was still having a little confusion, or maybe was even intimidated by this whole strapping thing, this helped simplify the whole process
  i was straightening up the tubes, and realized i really hadn't listened to the 408's i have, i put the erricson's in, the top end not quite what some of the others are
  but the bass sure is well defined and snappy, tuneful, which is a huge plus with the grado ps500
   
  and on another note, overnight i decided, even if i like the lyr, i'm keeping the little dot, this is just too much fun !


----------



## Edgard Varese

Quote: 





jaywillin said:


> indeed mordy thanks, yesterday i spent some time studying 77-79, and page 59 regarding this subject, i'm not sure why, but i was still having a little confusion, or maybe was even intimidated by this whole strapping thing, this helped simplify the whole process
> i was straightening up the tubes, and realized i really hadn't listened to the 408's i have, i put the erricson's in, the top end not quite what some of the others are
> but the bass sure is well defined and snappy, tuneful, which is a huge plus with the grado ps500
> 
> and on another note, overnight i decided, even if i like the lyr, i'm keeping the little dot, this is just too much fun !


 

 You can roll the Lyr too, but as I understand it there are a lot fewer options for tubes, and they are way more expensive than the ones we can use in the Little Dot.


----------



## jaywillin

Quote: 





edgard varese said:


> You can roll the Lyr too, but as I understand it there are a lot fewer options for tubes, and they are way more expensive than the ones we can use in the Little Dot.


 

 well, that's what got me thinking last night, a lot more "tuning" options and cheaper, it really was an impulse kinda thing, it wouldn't suprise me, if on down the road, i'll still have the ld 1+, and don't have the lyr, who knows


----------



## MIKELAP

gibosi burning in your Westinghouse 6AV6'S not to impressed so far then again its been a long day .tomorrow another day. Heres a picture looks like older  box .any idea on date theres 935 on tube or should i look on box i saw numbers on flaps


----------



## gibosi

Quote: 





mikelap said:


> gibosi burning in your Westinghouse 6AV6'S not to impressed so far then again its been a long day .tomorrow another day. Heres a picture looks like older  box .any idea on date theres 935 on tube or should i look on box i saw numbers on flaps


 
   
  Do they have square getters? Or halo getters? My best guess: 935 + 1959, week 35, especially if they have square getters. Either way, I agree that these are relatively old, the 1950s and 60s.
   
  And since they are "mine", I sure hope they sound better tomorrow! lol


----------



## siles1991

Quote: 





gibosi said:


> The HY90 is a rectifier, so no go. It was designed to be used in power supplies. The 6AN5 should work fine in the EF95 setting with no strapping required. To my knowledge no one has tried to these yet....


 
  if you dont mind me asking what are the guidelines on whether the tubes can be used or not?


----------



## mordy

Hi Edgard V,
   
  I did not mention that I use a small high intensity CREE LED flashlight when the need arises to see clearly where to put those little straps.
   
  Let me now how it goes with the straps.
   
  Good luck,
   
   
  Mordy


----------



## gibosi

Quote: 





siles1991 said:


> if you dont mind me asking what are the guidelines on whether the tubes can be used or not?


 
   
  In short, you grab a datasheet for the tube (*6AN5*) and look at the pin diagram. And then you compare the pinout to the EF1, EF92 and EF95. If the pinout is the same, you can simply plug it in, as appropriate. In the case of the 6AN5, you can see that the Beam Plates/Grid 3 and the Cathode are strapped together inside the tube. And if you compare this to the EF95 pinout, you will see the identical pattern. Therefore, I can see no reason why this tube wouldn't work in the EF95 setting.
   
  And this is the reason we strap pins in the socket: To make the tube pinout appear to be an  EF91, EF92 or EF95 so that we can then use them in the LD.


----------



## siles1991

Quote: 





gibosi said:


> In short, you grab a datasheet for the tube (*6AN5*) and look at the pin diagram. And then you compare the pinout to the EF1, EF92 and EF95. If the pinout is the same, you can simply plug it in, as appropriate. In the case of the 6AN5, you can see that the Beam Plates/Grid 3 and the Cathode are strapped together inside the tube. And if you compare this to the EF95 pinout, you will see the identical pattern. Therefore, I can see no reason why this tube wouldn't work in the EF95 setting.
> 
> And this is the reason we strap pins in the socket: To make the tube pinout appear to be an  EF91, EF92 or EF95 so that we can then use them in the LD.


 
  ahhhhhh i see thanks for enlightening me on this!!! So i assume even the 6GK5 could work since its connected 1/7?


----------



## gibosi

Quote: 





siles1991 said:


> ahhhhhh i see thanks for enlightening me on this!!! So i assume even the 6GK5 could work since its connected 1/7?


 
   
  No....
   
  LD amps expect that Grid 1 is always on Pin 1 and the Cathode is always on Pin 2. In the 6GK5, Grid 1 is on Pin 2 and the Cathode is on Pin 1.. So, you would somehow have to interchange pins 1 and 2 in order to get this tube to work... and the only way I can see to do this is with a custom-made socket converter.....


----------



## Edgard Varese

Quote: 





mordy said:


> Hi Edgard V,
> 
> I did not mention that I use a small high intensity CREE LED flashlight when the need arises to see clearly where to put those little straps.
> 
> ...


 
  Ah, very good point, thanks again Mordy.  I'm hoping to order some of those IBM 6BE6 tubes at the end of the month, if not the EK90 Telefunkens (nostubestore claims to have Telefunkens in stock but they are on vacation until the end of the month).  Maybe some EF94s as well...


----------



## GCooper

My resolve to avoid experimentation didn't hold and I ordered a ten pack of Soviet Cold War era mil-spec 6BE6 heptodes. Once sorted into matched pairs I'll install a set and compare these to the 6J1P-EV tubes currently gracing my LD III.


----------



## MIKELAP

Quote: 





gibosi said:


> Do they have square getters? Or halo getters? My best guess: 935 + 1959, week 35, especially if they have square getters. Either way, I agree that these are relatively old, the 1950s and 60s.
> 
> And since they are "mine", I sure hope they sound better tomorrow! lol


 
  Yes they have a square getter will have a listen again today they should sound similar to the other 6AV6 i guess hope your not disapointed lol.Like the old boxes dought ,never saw that style before and thanks for the dating    .on the flap i saw this H-4-59 thats probably the date.code  .


----------



## jaywillin

i know most of y'all are heptoding at the present, but after trying a lot more tracks, types of music, the erricsons 408a really does improve the
  mid bass of the ps500 !


----------



## Acapella11

Looks like the 6AN5 is a high heater current version of the standard EF95. Updated the table on p. 77 accordingly.


----------



## siles1991

Quote: 





acapella11 said:


> Looks like the 6AN5 is a high heater current version of the standard EF95. Updated the table on p. 77 accordingly.


 
  Found a few more like the 6HA5 = EC900.


----------



## gibosi

Quote: 





siles1991 said:


> Found a few more like the 6HA5 = EC900.


 
   
  Yes indeed, these triodes should work fine in the EF95 setting. This tube has only .18 amp heater current, which is a bit low compared to the .3 / .45 amp pentodes and heptodes we have been using recently, and I suspect that it will not play as loud. But still, .18 amp is about the same as the standard 6AK5 . The 6HM5 and 6HQ5 appear to be about the same.....


----------



## kvtaco17

Just got the RCA DETOX (6DT6 ) in and went straight to the 1/7 strap and wow! I really like these! Sound stage is very spacious, bass is good maybe a touch loose, mids are good similar to the EH90 Valvo I have, the treble is a little lacking in sparkle BUT I assume something will change with burn in... these would be perfect with some sparkle!


----------



## MIKELAP

Well gibosi your Westinghouse 6av6 are coming along nicely (24 hours)similar to the other 6av6 nice treble clean sounding tight bass nice crisp sounding good soundstage using the Senns hd800 and Conductor's Dac .


----------



## mordy

Hi kvtaco 17,
   
  Glad to see that you enjoy the DETOX tubes. In my system these tubes sounded good out of the box, but started to blossom around the 25 hour mark. You will see that the bass gets more tight; don't know about the treble changing so much.  Everything becomes _more_, if u know what I mean, The mid range is very sweet, and the sound stage enormous. I listen through speakers, and I also have tone controls to adjust for different recordings and I can turn up the treble if needed.
   
  There is a 6DT6A version as well, but I have not heard it yet.


----------



## jaywillin

ok, i must be doing something wrong, the seller that i bought the cbs hytron 6cs6 , sent me a set of rca  6cs6
  they made an even worse noise than cbs tubes, a loud steady hum
  the tubes construction appears a little different
  i tried ef95 and 91/92 ,
  i put the rca 5915's in, they sounded fine, so the amp seems ok, headphones ok
  i double checked the jumper placements, and the 5915 is playing now
  am i missing something ?


----------



## kvtaco17

Quote: 





mordy said:


> Hi kvtaco 17,
> 
> Glad to see that you enjoy the DETOX tubes. In my system these tubes sounded good out of the box, but started to blossom around the 25 hour mark. You will see that the bass gets more tight; don't know about the treble changing so much.  Everything becomes _more_, if u know what I mean, The mid range is very sweet, and the sound stage enormous. I listen through speakers, and I also have tone controls to adjust for different recordings and I can turn up the treble if needed.
> 
> There is a 6DT6A version as well, but I have not heard it yet.


 

 I tried them unstrapped and was meh... SO I made my straps permanent!

   
  It was a super easy solder job!
   
  I have the 6DT6A and its just as you described (I like my sparkle and as the bass tightens the treble comes out more) so far so good!


----------



## mordy

Hi kvtaco 17,
   
  Other people tried to solder wires to the pins and had a hard time. Could you please tell us how you did it? Did you file off the coating or use some special equipment?


----------



## kvtaco17

I cleaned the pins with sand paper (800 grit) and the sprayed some electronic contact cleaner on a rag and wiped it down. I stress using stranded 28/30 awg wire and tinning the ends lightly so they keep their form while soldering... other then that I didn't do anything special.


----------



## gibosi

Quote: 





jaywillin said:


> ok, i must be doing something wrong, the seller that i bought the cbs hytron 6cs6 , sent me a set of rca  6cs6
> they made an even worse noise than cbs tubes, a loud steady hum
> the tubes construction appears a little different
> i tried ef95 and 91/92 ,
> ...


 
   
  The one with the shiny ribbed plates is actually a GE 6CS6. Evidently, RCA contracted with GE for some 6CS6, and then simply rebranded them. I have one of these RCA/GE tubes too..lol
   
  The noise may go away after burn-in.... In my experience, if the noise appears immediately upon turning on the amp and becomes louder as the volume control is increased, it is likely a defective tube. If the noise appears gradually, as the tube warms up, and the amplitude does not change as a function of the volume control, then it is likely the noise will disappear after burn-in.
   
  Good luck!


----------



## gibosi

Quote: 





mikelap said:


> Well gibosi your Westinghouse 6av6 are coming along nicely (24 hours)similar to the other 6av6 nice treble clean sounding tight bass nice crisp sounding good soundstage using the Senns hd800 and Conductor's Dac .


 
   
  I am glad to know that my Westinghouse tubes meet with your approval. lol   As I recall you have a number of EBC91/6AV6... Do you have a favorite or two?


----------



## kvtaco17

Also to add I use NO-OX-ID A-special electrical grade to keep the pins from corroding after I clean them (really should be used on any connection) It's something I use for work on everything for telecom/data center on cable ends, lugs, termination points ext. It works very well with the small pins on these tubes I use a very thin layer (feel it can't see it) like in a telecom application. This stuff is greasy (don't use it where you'll end up touching it) and will get hard kinda over time so caking a bunch on a connection just makes it stick a bit.


----------



## gibosi

Quote: 





kvtaco17 said:


> I have the 6DT6A and its just as you described (I like my sparkle and as the bass tightens the treble comes out more) so far so good!


 
   
  I have about 20 hours on a pair of RCA 6HZ6 and these too are the same as you and Mordy describe the 6DT6. Great tubes for cheap!!


----------



## mordy

Hi Gibosi,
   
  I am sorry to tell you that personally I did not find the RCA 6HZ6 tubes as good as the RCA 6DT6. Below are my previously prepared comments:
    
   
  Here is a comparo of the pentodes RCA 6DT6 (hereafter dtox) and the RCA 6HZ6 (hereafter Herz) tubes. According to Gibosi's estimation both tubes are the same, but the Herz should sound louder because it has higher grain. Maybe they are twins, but not identical twins. It is more like the big bully brother Terz and the sweet sister Deetx, but I am getting ahead of myself......
   
  The Herz was a brute to break in. Firstly, as soon as I turned them on there was a loud hum. Oh no, what did I do? Luckily, it dissipated after a few seconds. In the beginning the tubes did not sound anything special. This continued for over 40 hours until the tubes finally opened up.  In addition, they ran very hot; too hot to touch.
   
  Another peculiarity: All my tubes I play with the LD volume setting at 3 o'clock. With these tubes I had to turn it down to around 1-2 o'clock to avoid a strange kind of "hollow" distortion.
   
  About settings:
   
  NS EF95 (P&P) : Fairly pleasant but light weight bass and sharp treble. Mid range harshness. Not especially wide sound stage
                           
  EF95  1/7 strap:  Sharp treble, mid range harshness, monster bass that goes very low. Sound stage average
   
  EF95  6/7 strap (simulated EF92):  Thin, sibilant sound, exaggerated treble, bloated bass - forget about it
   
  EF95  2/7 strap:  Pentode/heptode magic! Detail, monster bass, pleasant treble, very good instrument separation. Sound stage average. But:
  There is a strange mid range coarseness/harshness and a slight treble sibilance. It is not a mid range coolness, but rather the opposite of sweetness. Tartness? Harshness? Terseness? Coarseness?
   
  Perhaps these tubes will match somebody else's equipment better than mine, but these Herz 6HZ6 tubes are not among my favorites because of the mid range aberration. It must also be pointed out that the tubes came from two different production runs. The construction looks almost identical, but one tube has a copper post and one not. I could not detect any difference in sound after burn in.
   
*But what about the 6DT6 little sister dtox?*
   
*Well, this tube can compete with the best! What can I say? Beautiful, detailed strong bass, the sweetest mid range, and treble with the right amount of shimmer and great detail. A really satisfying, full bodied sound with the widest sound stage. On a good recording the sound stage and instrument separation is just amazing. Toe tapping index 5+.*
   
*All of the above pertains to EF95 1/7 strap setting*. The other settings (6/7, 2/7, NS) were all OK, but the sound was thin. Good bass, sibilant treble.
   
  G, amazing how different similar tubes can sound!


----------



## gibosi

Hmmm... I think I need to get a pair of RCA 6DT6.....


----------



## Edgard Varese

Just in the door this afternoon are 10 NOS NIB 6J3P-E from the Ukraine.  These are much taller than the usual compatible tubes for this amp, and the gain is much higher than the Voskhods I had in previously.  Just out of the box though... must be time for cooking.


----------



## jaywillin

Quote: 





gibosi said:


> The one with the shiny ribbed plates is actually a GE 6CS6. Evidently, RCA contracted with GE for some 6CS6, and then simply rebranded them. I have one of these RCA/GE tubes too..lol
> 
> The noise may go away after burn-in.... In my experience, if the noise appears immediately upon turning on the amp and becomes louder as the volume control is increased, it is likely a defective tube. If the noise appears gradually, as the tube warms up, and the amplitude does not change as a function of the volume control, then it is likely the noise will disappear after burn-in.
> 
> Good luck!


 

 the cbs, gradual and noise doesn't change, i'll burn this in longer
  the rca, instant and the noise doesn't change with volume change,, and it appears to be just one tube after switching sockets
  i have to get another power cord , the LD and the schiit are having to share ! lol


----------



## MIKELAP

Hey mordy do you have a link for those RCA 6DT6 cant seem to find much on ebay maybe there sold out. thanks


----------



## MIKELAP

Quote: 





gibosi said:


> I am glad to know that my Westinghouse tubes meet with your approval. lol   As I recall you have a number of EBC91/6AV6... Do you have a favorite or two?


 
  i tried to have a listen to all 6 pairs of 6av6 SYLVANIA, G.E. ,JAN.GE, WESTINGHOUSE ,LORENZ,HIT RAY,and man its hard to tell them apart personnally they all sound good to me and similar as i commented before.if theres differences i cant ear them  with these olden ears and i mean olden !


----------



## MIKELAP

Trying the G.E. 6DT6A  TUBES warmer sounding than the 6av6 tubes more laid back to me less agressive in the treble department this is out off the box impressions if they would stay the same i would be happy another good sounding pair imo                                                                                                                               .[size=x-small][/size]


----------



## Oskari

Quote: 





mikelap said:


> Trying the G.E. 6DT6A


 
   
  Seeing those CGE "Japan" tubes, I once again think that the mystery Siemens "foreign" tubes might be Japanese.


----------



## mordy

Hi Mikelap,
   
  Looks like you are right, can't find much in RCA 6DT6. I have not heard the RCA 6DT6A, perhaps it sounds the same. Maybe somebody out there has compared both?
   
  The other avenue to find these tubes is to be pro active. Contact the sellers that you have dealt with in the past that were cooperative, and ask if they have this tube. Many times it works, but I found that at times the seller suddenly jacked up the price because now _you_ are asking for something.
   
  Based on experience, a little patience always pays off. Just check Ebay often, and new items always come up.
   
  I myself only have one pair of these, so I have to follow my own advice....


----------



## jaywillin

Quote: 





jaywillin said:


> the cbs, gradual and noise doesn't change, i'll burn this in longer
> the rca, instant and the noise doesn't change with volume change,, and it appears to be just one tube after switching sockets
> i have to get another power cord , the LD and the schiit are having to share ! lol


 

 after some more hours on the cbs tubes, one tube silent, one much, much better
  the rca's, one tube is so bad, and the noise so loud,(and comes on instantly) i'm affraid it could cause
  some damage
  between the two sets, i can make 1 silent pair lol
  im burning the cbs's in more, the rca's i'm returning if the seller wants them


----------



## Audiofanboy

Finally back!

Sorry for the long absence, I was -and still technically am- on vacation in the US. Couldn't really post much or even catch up on the latest trends without a solid wifi in the middle of the American West -not that I would have wanted to considering the beautiful places I was in lol!

Anyway, so if I read everything correctly, we're closer to being in a "deep investigation" stage, where tube types -heptodes- are still being thoroughly investigated and searched for, rather than a "new tube type propaganda" stage, where old tube types and their users are publicly shamed and strongly encouraged to get new tube types like all the cool kids lol.

This being said, I'm a little curious about those heptode-ish dual control pentodes that are the 6DT6(A) and 6HZ6. These seem to basically be US types, and I left off on vacation investigating European heptodes so it's a bit off my map at this time, but I'll probably get a pair of dtox tubes just for kicks as a 6DT6 starter kit -I don't want to be pushed off the band wagon and miss all the fun; I've missed quite a bit as it is!

Now, what strikes me as odd is how little "progress" we've made on the 6CS6 and -Siemens- EH90 front. I mean, alternatives were found and there are more clues than ever, but we're still basically in the dark as to figuring out the pattern in these tubes or who actually made them... Then again, I still need to get a pair in the first place, which is difficult in and of itself!

What also strikes me is how so few people have tested or adopted those Blackburn and/or M.B.L.E. EH90 tubes. Those Belgian Mazda tubes -made on pseudo-Heerlen factory lines with Philips specs- were basically becoming my best tubes, with otherworldly bass and a euphonic balance that had me leaping back from one end of the Euro-tubiness continuum (C) to the other. Seriously lads, these tubes, both the UK and the Belgian-made ones, and the hypothetical NL ones, deserve more attention than they are getting!

First thing I'll do when I get home next week -after five tube-less weeks; imagine the horror!!- is to finish burning in and testing my Belgian EH90 and do the same with my -yet untested- Blackburn EH90, so I can compare them and reach some kind of conclusion. Hopefully, other EH90 addicts will chime in before I order some Dtox lol.

Anyway, I don't have much to add at this point, seeing as I'm kind of amp-less right now, but good work keeping the thread as clean and relevant as before, and ever more active and useful for LD users/addicts! I'll try and get back to being useful and productive around here asap lol.


----------



## mordy

Sumthin' gotten lost in the translation?  Antidote for gall stones?
   
  Availability: 5 In stock   *SKU:13179128672*
  US$14.26
    Total Price:*US$14.26 x 1 = *US$*14.26* 
   Qty5Instock)

   
   
   




 


 

   

 Tubes of bile 6DT6   
  http://www.clickgou.com/Product/13179128672/Tubes_of_bile_duct_6DT6/


----------



## kvtaco17

Quote: 





audiofanboy said:


> Finally back!
> 
> Sorry for the long absence, I was -and still technically am- on vacation in the US. Couldn't really post much or even catch up on the latest trends without a solid wifi in the middle of the American West -not that I would have wanted to considering the beautiful places I was in lol!
> 
> ...


 

 Its still a work in progress, I have more EH90's coming (shipping from Russia sucks...) The DETOX is a fun tube (the RCA version) currently evaluating it... its close to becoming my favorite tube so far.


----------



## kvtaco17

Quote: 





mordy said:


> Sumthin' gotten lost in the translation?  Antidote for gall stones?
> 
> Availability: 5 In stock   *SKU:13179128672*
> US$14.26
> ...


 

 OH HELL NO! That's spendy! My pair was $6 shipped!


----------



## MIKELAP

Would 6AQ5 tubes be good for us 6AQ4 AND 6AQ6 are on the list thanks shopping tonight cant stop!


----------



## jaywillin

Quote: 





kvtaco17 said:


> OH HELL NO! That's spendy! My pair was $6 shipped!


 

 i just got 2 of those $6 tubes


----------



## kvtaco17

Quote: 





jaywillin said:


> i just got 2 of those $6 tubes


 

 Well played.


----------



## gibosi

Quote: 





mikelap said:


> Would 6AQ5 tubes be good for us 6AQ4 AND 6AQ6 are on the list thanks shopping tonight cant stop!


 
   
  The 6AQ5 is very different than either the 6AQ4 or the 6AQ6, both of which are triodes. The 6AQ5 is a "Beam Pentode" designed for use in television and radio receivers. But it looks to me like it will certainly work in the LD in the EF95 setting. No strapping in the socket is necessary or possible. One possible caveat is that the gain of this tube is only 9.5 which is exceedingly low. For example, the 6AV6 has a gain of 100 and the 6AU6 has a gain of 36. Thus, one might predict that this tube will not get very loud...
   
  http://www.r-type.org/pdfs/6aq5-2.pdf


----------



## MIKELAP

Quote: 





gibosi said:


> The 6AQ5 is very different than either the 6AQ4 or the 6AQ6, both of which are triodes. The 6AQ5 is a "Beam Pentode" designed for use in television and radio receivers. But it looks to me like it will certainly work in the LD in the EF95 setting. No strapping in the socket is necessary or possible. One possible caveat is that the gain of this tube is only 9.5 which is exceedingly low. For example, the 6AV6 has a gain of 100 and the 6AU6 has a gain of 36. Thus, one might predict that this tube will not get very loud...
> 
> http://www.r-type.org/pdfs/6aq5-2.pdf


 
  Thanks for the infos  gibosi its appreciated


----------



## Acapella11

Quote: 





audiofanboy said:


> What also strikes me is how so few people have tested or adopted those Blackburn and/or M.B.L.E. EH90 tubes. Those Belgian Mazda tubes -made on pseudo-Heerlen factory lines with Philips specs- were basically becoming my best tubes, with otherworldly bass and a euphonic balance that had me leaping back from one end of the Euro-tubiness continuum (C) to the other. Seriously lads, these tubes, both the UK and the Belgian-made ones, and the hypothetical NL ones, deserve more attention than they are getting!


 
   
  Hi Audiofanboy, I also liked the Valvo EH90 tubes I have. To write more about it, I need a good pair though. Mine are a) not matched and b) one of them distorts slightly. I am getting a replacement tube and a new pair in of which both have a grey manufacturing code.
   
  I am still on the case with the black bottom Siemens replacement tubes.
   
  Off topic: If anyone fancies a solid state alternative, have a look at the Burson Soloist SL. I have just had it at home.


----------



## gibosi

Quote: 





gibosi said:


> ....The 6AN5 should work fine in the EF95 setting with no strapping required. To my knowledge no one has tried to these yet....


 
   
  A pair of Raytheon JAN 6AN5WA, 18th week of 1969 arrived in today's mail. Looking at these, the plates remind one of the 6AH6. Anyway, they light up and play using the EF95 setting with no strapping. So if anyone was waiting to know if these will work, the answer is yes. As to sound, it is too soon to say, but they are very quiet and I am not noticing anything unusual, so at worst, they are likely average, if not great.


----------



## hypnos1

Quote: 





audiofanboy said:


> Finally back!
> 
> Sorry for the long absence, I was -and still technically am- on vacation in the US. Couldn't really post much or even catch up on the latest trends without a solid wifi in the middle of the American West -not that I would have wanted to considering the beautiful places I was in lol!
> 
> ...


 
   
  Welcome back AFB - how could you leave us all for SO long!...Hope you had (and are still having?) a wonderful time Stateside. Now it's back to work, mon ami...
   
  I've been plugging the EH90s for so long now, I thought people might be getting fed up with it!! , peut-etre...
  What I am sure you will find interesting is the difference in results between myself, with HD650s, and A11 with HD800s (we both have basically the same DAC).
   
  I am also really looking forward (as I am sure are others) to your comparison of the M.B.L.E.s and the Blackburns. I could swear my B5I4s (GE1) are superior to the Mazdas (Valvo, L0D&F, GE3)...But sometimes assessments can get skewed, n'est-ce pas?
   
  Waiting in anticipation...
   
  Cheers,
   
  CJ


----------



## MIKELAP

Ordered several tubes the 1680 IBM  6BE6 ,RCA 6HZ6, and RAYTHEON 6AN5 should be here in a week.


----------



## Acapella11

Quote: 





hypnos1 said:


> I've been plugging the EH90s for so long now, I thought people might be getting fed up with it!! , peut-etre...
> What I am sure you will find interesting is the difference in results between myself, with HD650s, and A11 with HD800s (we both have basically the same DAC).


 
   
  Hey Hypnos, Gibosi had the opportunity to listen to the Foreign Siemens EH90 and the HD800, maybe he would comment on it if you pm him.
   
  PS: Which filer are you using on your 8200CD?


----------



## jjsoviet

Got the 6N6P-IR power tubes just now 
   
  Still burning them in, but it seems that these tubes increase the clarity a bit. Take note though that I'm using the SRH840 which isn't exactly paired well with the LD MKIII but the difference is there.
   
  Since my amp is most probably a very early version (its pair of jumpers only have two pins), which other driver tubes should I consider getting? Currently enjoying the Voshkods so far.


----------



## Acapella11

So many tubes to suggest. I would look in the heptode corner, e.g. Lorenz SEL EK90, Telefunken EH900S (Made in Germany, Ulm with Uxxxxxx code), Valvo EH90 (with additional grey manufacturing code if you can get), IBM 1680 6BE6.
  
 If you get the Telefunken EH900S, don't forget to try them 1/7-strapped.
  
 You are saying that the Shure do not fit the LD well because they are lower impedance (42 ohm) phones? On the other hand, they have a sensitivity of 102 dB, which means they don't need much power to get loud (Hifiman HE-500 has 89 dB) plus you have dynamic drivers not orthos. I would say, they should be fine with the LD.


----------



## jjsoviet

Quote: 





acapella11 said:


> So many tubes to suggest. I would look in the heptode corner, e.g. Lorenz SEL EK90, Telefunken EH900S (Made in Germany, Ulm with Uxxxxxx code), Valvo EH90 (with additional grey manufacturing code if you can get), IBM 1680 6BE6.
> 
> If you get the Telefunken EH900S, don't forget to try them 1/7-strapped.
> 
> You are saying that the Shure do not fit the LD well because they are lower impedance (42 ohm) phones? On the other hand, they have a sensitivity of 102 dB, which means they don't need much power to get loud (Hifiman HE-500 has 89 dB) plus you have dynamic drivers not orthos. I would say, they should be fine with the LD. 
   
  Yeah, listening them off the LD the SRH840 sounds fine to me at the lowest gain setting. I thought it wouldn't pair well just like other low-impedance cans like Grado and Alessandro headphones. Some say those work better with the LD MK1+ than with the MK3.
   
  Are these tubes you're suggesting require any changes to the jumper settings on my part? When I bought it I haven't fiddled with them at all and played it safe by only looking at the EF95 family. That, and I kind of lost the jumper switches.


----------



## TrollDragon

And the RCA 6BE6's are at the Postoffice, but as usual closed till Monday...

Monday night will be Heptode night, finally... 






Sent from my HTC Desire HD A9191 using Tapatalk 2


----------



## Acapella11

Quote: 





jjsoviet said:


> Are these tubes you're suggesting require any changes to the jumper settings on my part? When I bought it I haven't fiddled with them at all and played it safe by only looking at the EF95 family. That, and I kind of lost the jumper switches.


 
   
  Hi JJ, you can use them all without mods. However, I would advise to use a small stranded wire for the 1/7-mod in case of the Tlefuneken and the Valvo EH 90, and maybe 2/7 for the IBM. Check page 77 for details.


----------



## kvtaco17

Quote: 





acapella11 said:


> Hi JJ, you can use them all without mods. However, I would advise to use a small stranded wire for the 1/7-mod in case of the Tlefuneken and the Valvo EH 90, and maybe 2/7 for the IBM. Check page 77 for details.


 
  I'll try the EH90 1/7 strap... tomorrow... I'm too drunk to coordinate that right now,,,


----------



## Audiofanboy

kvtaco17 said:


> I'll try the EH90 1/7 strap... tomorrow... I'm too drunk to coordinate that right now,,,




Lol, though I can relate to this situation somewhat, remember the 11th commandment: "Thou shall not post while intoxicated"!

Do try the strapping when you're better though, it yields interesting results (and it is kind of hard to do when drunk, inevitebly).


----------



## kvtaco17

I have tried it... Just not on the eh90 yet...


----------



## hypnos1

Quote: 





acapella11 said:


> Hey Hypnos, Gibosi had the opportunity to listen to the Foreign Siemens EH90 and the HD800, maybe he would comment on it if you pm him.
> 
> PS: Which filer are you using on your 8200CD?


 
   
  Hi A11,
   
  Perhaps your experience with the Siemens plus HD800, and mine plus HD650s (as Gibosi - hope you don't mind, G - was able to ascertain) will shed light for others when assessing their EH90s. The cans really do seem to make a big difference to what a particular tube will deliver, given that all else is fairly equal...So AFB's findings will be doubly interesting - hopefully!
   
  BTW. Was on Optimal Transient XD, but at the moment am listening on (your?) Optimal Spectrum - and mid/upper treble seems to be delivering a bit more, along with subsequent increased airiness...nice. Plus a little more volume. Will need further testing, but this could be the one from now on - wonder if this is down to the lovely LD/tube combo going against the general concensus praising O T XD?


----------



## Acapella11

Quote: 





hypnos1 said:


> Hi A11,
> 
> Perhaps your experience with the Siemens plus HD800, and mine plus HD650s (as Gibosi - hope you don't mind, G - was able to ascertain) will shed light for others when assessing their EH90s. The cans really do seem to make a big difference to what a particular tube will deliver, given that all else is fairly equal...So AFB's findings will be doubly interesting - hopefully!
> 
> BTW. Was on Optimal Transient XD, but at the moment am listening on (your?) Optimal Spectrum - and mid/upper treble seems to be delivering a bit more, along with subsequent increased airiness...nice. Plus a little more volume. Will need further testing, but this could be the one from now on - wonder if this is down to the lovely LD/tube combo going against the general concensus praising O T XD?


 
   
  Off topic:
  - System Matching -
  Cheers H1, yes, system matching is king. Another example: I tried the HE-500 with a Burson HA 160, it works well and so it does with a HE-500LE (excellently actually). Now, one would conclude that an amp for one is good for the other... Then connecting the HE-500 to the Burson Soloist SL gives a favourable result but not with the HE-500LE. The amp is just too dark for them. Connecting the HD800 to the SL works very well but the HA-160 doesn't. It emphasizes some brightness the HD800 picks up too much. You never know until you try.
   
  Back to topic (kind of):
  - Audiolab and LD -
  My guess is that the valve amp slightly softens the audio image anyway, which is what OT XD does. Optimal spectrum is the most honest and detailed mode, IMO.It uses a short ringing and pictures notes straight as they are. All the transient modes do smear the tones to a certain extend (longer decay), which reduces the accuracy of the presentation. Since the LD adds its own version of this effect in form of even order harmonic distortion, IMO, it works better when it is fed with straight, short ringed tones. The transient modes are IMO rather useful for those solid state amps, which offer a rather dry and decay-less presentation.
   
  Page 77:
  Added 6HA5, 6HM5, 6HQ5 triodes. Thanks kvtaco17 and gibosi.


----------



## mordy

A lot of tube information can be found on sites that deal with guitar tube amplifiers. On one such site I found this rendition of a RCA tube, perhaps made by a graphic designer/guitar player smoking something.
   
  My present favorite tube is the RCA detox (6DT6) but I only have one pair. In my search for more pairs in the 99c stores I couldn't find anything at all; really nothing, except for eccentric sellers with the items at higher prices..
   
  I ordered something from one seller and paid him/her (looks like a couple because I got emails from two different addresses for the same tubes). After I paid I got an email that the tubes weren't really the same date and the second pair had a defective tube, so they refunded my money. OK, what can you do? Well, you can leave x!#*** feedback, but I did not want to that.
   
  Ordered another set of tubes, different ones, from the same people. Was quoted $5.95, but the invoice said $5.25, which is what I paid. (I can just see the couple fighting: Why didn't you charge enough! We'll get him next time!)
   
  Tubes were fine. Inquired if they had two pairs of this and that. Next thing I get an invoice for both pairs, but instead of the $5.25 I was charged $7.95 and $5.95. I pointed out two things: I had only inquired if they had these tubes in stock, and I had expected them to be priced the same as the previous shipment since they were very similar.
   
  Silence. After a reminder or two I got an email that if I am not interested they will cancel the invoice for $13.90. I was going to thank them for this, because I found the same two pairs of tubes from a very honest seller for $8.75, but I resisted sending them an email to that effect.
   
  Two weeks later I offered to buy one of the pairs from before for the stated price of $5.95, but I was totally ignored. Oh well...
   
  Fast forward:
   
  Today I found what I wanted, or so I thought. This place claims that they have millions of tubes. A big ad proclaims: Summer Sale (ends 12/31/13(!). All tubes on the list $1.00!
   
  Well, there is my Dtox tube listed (and Herz too). Great, I'll try them and then I will inform everybody where to get these bargains. So I asked if they have the TS and RCA. The answer was: Sure - how many do you want? The price is $4.00 each.
   
  You guessed it: I pointed out that they should be $1 each according to their ad. Here is the answer:
   
  [size=x-small]HELLO,  SORRY,  FOR THE DOLLAR PRICE,  YOU GET THE BRANDS YOU GET,  WE DO NOT PICK BRANDS OR MATCH DATE CODES,  THIS IS A TIMELY PROCEDURE FOR US,    UP TO YOU,  REGARDS[/size]
   
  I can just see how the guy goes into the warehouse of millions of tubes and starts looking for the 6DT6 tubes. After opening 54 cartons he finds the TS tubes. No way! We are going to look further and ship this guy the Philco tubes! What does he expect for a buck???
   
  Having been in the retail business for many years, I always wonder how these people stay in business despite themselves.....
   
  Anyhow, I _did_ find tubes for $1 each, but I don't want to report until I receive them (less than $6.00 for the pair including shipping.)


----------



## hypnos1

Quote: 





acapella11 said:


> Off topic:
> - System Matching -
> Cheers H1, yes, system matching is king. Another example: I tried the HE-500 with a Burson HA 160, it works well and so it does with a HE-500LE (excellently actually). Now, one would conclude that an amp for one is good for the other... Then connecting the HE-500 to the Burson Soloist SL gives a favourable result but not with the HE-500LE. The amp is just too dark for them. Connecting the HD800 to the SL works very well but the HA-160 doesn't. It emphasizes some brightness the HD800 picks up too much. You never know until you try.
> 
> ...


 
   
  Thanks A11. Once again more info on topics that do have relevance, both direct and indirect, for all LD owners - I would imagine...


----------



## gibosi

Saw this listing this morning:
   
  A "foreign" Mazda EH90. It sure looks like the "foreign" Siemens and Zaerix Miniwatt!
   
  http://www.ebay.com/itm/EH90-MAZDA-ELECTRONIC-VALVE-/251326490969?pt=UK_Sound_Vision_Valves_Vacuum_Tubes&hash=item3a8439e959


----------



## hypnos1

Quote: 





gibosi said:


> Saw this listing this morning:
> 
> A "foreign" Mazda EH90. It sure looks like the "foreign" Siemens and Zaerix Miniwatt!
> 
> http://www.ebay.com/itm/EH90-MAZDA-ELECTRONIC-VALVE-/251326490969?pt=UK_Sound_Vision_Valves_Vacuum_Tubes&hash=item3a8439e959


 
   
  Yep,G - so now we have Mazda EH90s WITH ribs, a la Siemens 'foreign', and M.B.L.E. Mazdas WITHOUT...the story gets even more convoluted,lol.
  Especially as the smooth-plated (Philips group) tubes would definitely appear to be the better of the two types for most people.
   
  Continued happy rolling everyone!...


----------



## gibosi

After reading Mordy's remarks (HERE) regarding the RCA 6HZ6, and noting that his experience with this tube is very different than mine, I believe that perhaps he must have received a bum pair....
   
  As I do not yet have my pair of RCA 6DT6A, I have been comparing this tube to the IBM (RCA) 1680, the RCA JRC 5915 (6BY6) and a number of European EH90s.
   
  Some RCA 6HZ6 have dark gray plates and some have light gray plates. Also, some have copper electrodes and some don't. While I doubt that any of these differences are significant, I thought I should mention them. I have four of these tubes, three light gray and one dark gray, and all with copper electrodes. Of those, I have selected the two shown below as they seem to match up well in terms of construction and printing/logo. (And I am assuming that the same printing and logo would indicate they were manufactured around the same time.) 
   

   
  I have found that the best way for me to quickly compare tubes is to listen to how they recreate the female voice, and of late, have been listening to Mim Grey - "Miles from Somewhere" on her Chasing Tigers album. Not surprisingly, I think, I find the RCA 6HZ6 to be very similar to the 1680 and the 5915. They all share what might be called an "RCA two control grid house sound" (doesn't that just roll off the tongue? lol), rather forward with warm sweet vocals. In fact, I found these three tubes to be so similar that at times I lost track of which tube I was listening to. I have the impression that the sound stage of the 6HZ6 is a bit wider and the bass seems to hit a bit harder, but again, this was a quick comparison, so you should take this with a grain of salt. Otherwise, these three tubes are all very similar. Also, the 6HZ6 do run hot, but after all, with .45 amp heaters, this is not surprising. 
   
  Of the European EH90s, the one that comes closest is the Telefunken, which is similarly forward with a nice touch of warmth. I think if you like any of these other tubes, you would like the RCA 6HZ6, and based on my experience, I recommend this tube.
   
  I should have a pair of RCA 6DT6A later this week, and of course, I will come back here to tell you if I find them to sound the same... or different....
   
  Edit: All comparisons were done using the EF95 1/7 setting


----------



## Oskari

Quote: 





gibosi said:


> A "foreign" Mazda EH90. It sure looks like the "foreign" Siemens and Zaerix Miniwatt!
> 
> http://www.ebay.com/itm/EH90-MAZDA-ELECTRONIC-VALVE-/251326490969?pt=UK_Sound_Vision_Valves_Vacuum_Tubes&hash=item3a8439e959


 
   
  That's the UK Mazda brand.


----------



## MIKELAP

Should be getting 6AN5 ,6HZ6 and IBM 1680/6BE6 in a week good thing fall is on its way should have more time to experience the tubes i gathered over the course of the summer im way behind .Its not a bad thing really .


----------



## Acapella11

Intro
 Since a while, I have been considering that the higher quality standard heptodes do sound better but often they lack a bit of sparkle from a very refined treble such that they slightly sound out of tonal balance (special quality 6BY6, 6BE6W). I have been going though these tubes quite a bit, using 1/7 and 2/7 in order to spice them up. Since I do like 6BE6 tubes quite a bit, I hoped to get something out of 6BE6W tubes.
  
 Today, I went again through Haltron (= Brimar) CV4012, Sylvania 5750, Raytheon 6BE6W and Siemens black bottom EK90 because I got myself a new optical cable and interestingly it sounds nice, different to and also darker than the USB-cable I have but it also images with more plasticity.
  
 Preliminary impression
 Now, I didn't actually plan to post. Having in mind that these tubes sound quite refined treble wise (the Siemens lesser so), I tried 1/7, 2/7 again to bring them more to life, and I really like the Sylvania because of its great imaging and amazing bass in 2/7 but still the tube sounds a bit too dark for my liking.
 Then I tried 6/7 again (= EF91/92). Now, I haven't used this setting that much recently, and before the results were ambigous but you never know until you try. The tube I am listening to as I am typing is the *Raytheon 6BE6W in 6/7-strap* and I am very impressed. First thing, it sounds amazingly transparent, which gives really nice focus and instrument separation. Complex orchestras become real fun to listen to. The stage is a good size making the tube not being forward and presenting a good space. The stage is actually fairly extensive, as in wide and deep. I am just getting used to the optical cable and the stage appears smaller than using the USB. Bass and treble are also well balanced. The bass hits hard and goes deep, a bass treat. The treble is heptode type refined and extended, not pronounced sparkly but with a very good presence. The signature is a bit on the warmer side of neutral. It has good crunch to it. I love it. Now before I go on, I should better stop and keep you updated. It is transparent... 
  
 Edit: Corrected stage and general impressions.


----------



## kvtaco17

Rolled a LME49990 as per Gibsoi and I like it so far with the EH90 and DTox great setup! Now on a few tracks I miss the Burr Brown warmth of the 2107 BUT for 90% of music I like the LME49990 better (I have 2 OPA627AP inbound to test). I also received my socket savers so I am now ready for some extreme tube rolling! (Still waiting on the Ediswan EH90 and the Svetlana 6A2P)
            

   
                             
 GLORIOUS!   
   
  OH and the Valvo EH90 1/7 strap is a minor improvement (depends on tastes) on the no strap EF90... slightly tighter bass (less quantity) and more extended treble... not as warm, drier, airier   without sibilance.


----------



## TrollDragon

The 6BY6 have landed!
I am ecstatic... sorry guys my first set of tubes which is all old hat for you pro's, but I'm like a kid in a candy store. 

These are RCA's, not a date code to be found anywhere, two have round getters and two have a rectangular wire getter. One of the tubes has a fairly bent pin that I am going to straighten carefully with my thumbnail. Is this common for supposedly NOS tubes?

The two with rectangular getters are a little different, one tube has a little larger holes in the shield than the other one does.

I'll post some pictures in a bit if anyone wants to see them, right now I'm off to clean some pins.


----------



## MIKELAP

Quote: 





trolldragon said:


> The 6BY6 have landed!
> I am ecstatic... sorry guys my first set of tubes which is all old hat for you pro's, but I'm like a kid in a candy store.
> 
> 
> ...


 
  Funny you mention RCA  6BY6 tubes thats what i have on .they sound real nice about bent pins it happens all the time. Enjoy your tubes


----------



## gibosi

Quote: 





trolldragon said:


> The 6BY6 have landed!
> I am ecstatic... sorry guys my first set of tubes which is all old hat for you pro's, but I'm like a kid in a candy store.
> 
> 
> ...


 
   
  It seems that you, MIKELAP and myself are having quite an RCA kind of day! As I posted earlier today, I've been listening to the RCA 6HZ6, IBM (RCA) 1680, and the RCA JRC 5915 (the premium version of 6BY6). And late this afternoon, I received a pair of RCA 6DT6A, which are burning in as I write this. So it looks like tomorrow is going to be another RCA kind of day for me. 
   

   
  In dating RCAs look for a two letter code. From the following PDF, bottom of page 18, the "NM" on the left tube above indicates a manufacturing date of January, 1964.
   
  http://mysite.verizon.net/tubetronic/PDF_FILES/RCA%20DATE%20CODES.pdf
   
  And yes, it is not uncommon to get tubes with bent pins. You have to remember that while NOS tubes have never been used, storage conditions over the past 50 or so years may not have always been the best.....


----------



## gibosi

Quote: 





kvtaco17 said:


> Rolled a LME49990 as per Gibsoi and I like it so far with the EH90 and DTox great setup! Now on a few tracks I miss the Burr Brown warmth of the 2107 BUT for 90% of music I like the LME49990 better (I have 2 OPA627AP inbound to test).


 
   
  So you think the LME49990 is pretty good, eh? 
   
  I will be curious to learn what you think of the OPA627AP. I have a LME49720HA on the way and wonder how it could be any better? But soon, I will find out....


----------



## kvtaco17

Quote: 





gibosi said:


> So you think the LME49990 is pretty good, eh?
> 
> I will be curious to learn what you think of the OPA627AP. I have a LME49720HA on the way and wonder how it could be any better? But soon, I will find out....


 
  The only thing holding me back from loving it and staying put is my love of the old Burr Brown warmth, if the LME49990 had a touch of warmth it would be my end game OP amp for the little dot.


----------



## gibosi

Quote: 





kvtaco17 said:


> The only thing holding me back from loving it and staying put is my love of the old Burr Brown warmth, if the LME49990 had a touch of warmth it would be my end game OP amp for the little dot.


 
   
  I understand. The Burr Brown warmth superbly compliments some tubes. But the lack of that warmth, a neutral and transparent sound signature which allows the "true flavor" of the tube to be revealed was my goal in selecting the LME49990. And my thinking was that if I want a touch of warmth, I can simply choose a warm tube.
   
  But all else being equal, maybe I would prefer a LME49990 with just touch more warmth... I don't know.... If you find such an opamp, I would certainly be interested in giving it a try.


----------



## TrollDragon

Here are the 6BY6's
   

   

   
  I put the pair in with the round Getter and have been listening to The Best of Acoustic by Jethro Tull and I am absolutely amazed at how much better these sound over the stock GE5654's.
  There is actually some Bass in this amp now! When I first set it up I was missing the Bass that my SS amp provided, but now this is impressive.
  I'll have to make some straps and see what the different configurations sound like as well as the square Getter versions
   
  Are there any other tubes with a nice deep clean Bass response?
   
  One thing I did not realize is how easy the markings come off the glass, I was holding the one on the right in the picture with the 2 6BY6 markings in a cloth while I cleaned the pins with some 600 grit Wet/Dry paper and all the text below the lower number is gone, well I wont do that again. 
	

	
	
		
		

		
		
	


	



   
  These tubes must have been handled quite a bit before as they only have the number legible on all them, no date codes can be seen, I checked before I cleaned the pins and held the tubes between point and pins so I didn't wipe any markings off at that point.
   
  Thanks MIKELAP and gibosi for the date code link.


----------



## TrollDragon

Now If you guys are looking for opamps...
   
  I was going to build some amps a long while back and I have these that have never been used or removed from the static bag / tube.
   


Spoiler: My%20opamp%20inventory



 
  2x LME49860NA
  4x LME49990MA
  3x LME49880MR
  4x LME49600
  4x LME49713HA Metal CAN
  4x LME49720HA Metal CAN
  4x AD8620ARZ
  2x AD8610ARMZ
  2x AD8065ARZ
  2x AD8937ARZ
  2x AD8512ARZ
  2x ADA4075-2ARZ
  4x OPA4134UA
  2x OPA2107
  2x OPA227PA
   


   


Spoiler: I%20also%20have%20an%20SMT%20to%20dip%20adapter%20kit%20with%20machined%20pins.%20you%20just%20break%20off%20the%20board%20you%20need.



    

   


   
  The thing I will never use any of these anytime soon so if you would like to trade for some nice tubes then by all means shoot me a PM.


----------



## KR500

Howdy all;
   
  Longtime lurker, first time poster
  Thanks to all the posters there is some interesting and helpful information here regarding options to upgrade our LD amps.
  Also hats off to David for an affordable , tweakable good-sounding little amp.
  I own a Little Dot Mark II+ and have ordered some preamp and driver tubes earlier this summer to roll per the recommendations here.
  Swapped out the OEM stock Chinese tubes for the following pairs of preamp tubes to listen to . JAN GE 5654, 6J1P-EV Novobirsk OTK , and Mullard M1800. So far the 8100's are the ones I like the most,
  The power tubes are a pair of Russian Reflektor 6N6P I got from the Tube Maze store and got a similar pair of the 6N6P's from Bulgaria that sound and look the same but look to have not been stored as carefully which are spares now . The Tube Maze store packs their tubes very carefully which was nice. Also Langtrex in Great Britain does too. Both on Feebay.
  I just upgraded my Audio Technica ATH AD700 open phones to the ATH-AD900X which are about $120 more and sound twice as good with better bass and pads.
  The more expensive 900's have a cheaper slip on plug end though which is a definite step down from the 700's screw on plug which is more substantial and secure. I really wanted to get the Sennheiser HD650's and probably should have just saved longer until I could afford them. 
  Recently I swapped out the stock provided power cable that came with my LD since I had a spare quality cord in the closet . Has anyone else upgraded their LD power cable besides myself?
  Next week I'm going to order the Mullard milspec EF92 to try but may end my tube rolling experiments after that.
  I use a Schitt Bi-Frost DAC with TASCAM CD player or Mac Mini as sources.
  Rega 3 TT with Bellari for vinyl


----------



## kvtaco17

Looked goofy with the socket savers... so I fixed it...


----------



## mordy

Welcome to the forum KR500!
   
  Presently I do most of my listening through speakers, but I do have the Audio Technica ATH AD700 headphones (same as your old ones). Truth is that my speakers have better resolution than my ATH AD700 headphones.
   
  One reason I like the AT phones is that they are very comfortable to wear (and don't laugh!) they don't make my ears feel hot. A few years ago I had a set of Sennheiser HD600, but I could not wear them for a long time because they made my ears too hot and uncomfortable, and I felt that they contributed to earwax buildup.
   
  Are the ATH - AD900X headphones as comfortable as the AD700? I read good things about them in Stereophile magazine.
   
  I am thinking of getting a better set of headphones, moderately priced of course, and would appreciate suggestions. Light weight and comfort are important to me, as well as the sound.


----------



## kvtaco17

Quote: 





mordy said:


> Welcome to the forum KR500!
> 
> Presently I do most of my listening through speakers, but I do have the Audio Technica ATH AD700 headphones (same as your old ones). Truth is that my speakers have better resolution than my ATH AD700 headphones.
> 
> ...


 
   


 I love my AD900x, its great for the price! I pretty good upgrade over the AD700.


----------



## gibosi

RCA 6HZ6 and 6DT6/A
   

   

   

  I am unable to discern any sonic differences between these two tubes. Mim Grey's voice is delicious, warm and full; the bass is satisfyingly deep, punchy and clean; and the highs are well detailed with a nice bit of sparkle. Further, the sound stage is exceptionally wide and instrument separation is excellent. In my experience, everything Mordy writes about the 6DT6 is also true about the 6HZ6 in my possession.
   
  That said, I prefer the 6DT6/A only for the fact that it runs cooler. The 6HZ6 runs quite hot, so unless the extra gain .45amp heaters might provide is important in your setup, I recommend the 6DT6/A over the 6HZ6.


----------



## gibosi

Quote: 





trolldragon said:


> Here are the 6BY6's
> 
> 
> I put the pair in with the round Getter and have been listening to The Best of Acoustic by Jethro Tull and I am absolutely amazed at how much better these sound over the stock GE5654's.
> ...


 
   
  A very easy recommendation is any EH90 manufactured by Philips. These tubes might have any number of brand names printed on the glass, Philips, of course, and also Mullard, Valvo, Siemens and perhaps others as well. This is a top tier tube in every way, with especially excellent bass. If you search this forum, you will find very strong endorsements of this tube by Hynos1 and Audiofanboy.
   
  What you are looking for is a tube with smooth dark gray plates and rather large tall holes. For example:
   
  http://www.ebay.com/itm/Mullard-EH90-Valves-/171004688579?pt=UK_Sound_Vision_Valves_Vacuum_Tubes&hash=item27d0ac78c3
   
  http://www.ebay.com/itm/EH90-EH-90-6CS6-VALVO-NOS-NEW-MCINTOSH-/221267124842?pt=DE_TV_Video_Audio_Elektronenr%C3%B6hren_Valves&hash=item33848c626a
   
  http://www.ebay.com/itm/1x-EH90-6CS6-PHILIPS-NOS-BRITISH-Tube-Rohre-Lampe-TSF-Valvola-Valvula-/260873874189?pt=Vintage_Electronics_R2&hash=item3cbd4b6b0d
   
  http://www.ebay.com/itm/1-neue-Rohre-Siemens-EH90-mit-originaler-Box-U58-/380558649752?pt=R%C3%B6hren&hash=item589b102998
   
  (I have selected these to give suitable examples. I am not suggesting that any of these is a good deal....)
   
  Happy hunting!! 
   
  Edit: Oh, another tube with great bass is the RCA 6DT6!


----------



## TrollDragon

Quote: 





gibosi said:


> A very easy recommendation is any EH90 manufactured by Philips. These tubes might have any number of brand names printed on the glass, Philips, of course, and also Mullard, Valvo, Siemens and perhaps others as well. This is a top tier tube in every way, with especially excellent bass. If you search this forum, you will find very strong endorsements of this tube by Hynos1 and Audiofanboy.
> 
> What you are looking for is a tube with smooth dark gray plates and rather large tall holes. For example:
> 
> Edit: Oh, another tube with great bass is the RCA 6DT6!


 
  Thanks gibosi!
   
  I really appreciate all the links so I know what to look for, those EH90's are pricy, so I'll have to keep a watch out for a deal on some... 
   
  The 6DT6's on the other hand are very reasonable! 
   
  Are the Haltron 6CS6 from Japan on par with the EH90's you linked?


----------



## Audiofanboy

Alright! Finally back in my -primary- country, and almost back in the game now that I have my amp back; if it weren't for the fact that I'm soooooo tired...! Jetlag is one the thing I just can never get used to even after traveling for most of my life...
   
  But fear not, I _will_ end up giving those final impressions on Belgian and UK EH90 tubes. I just strapped the tubes back in and am warming the amp up for a good listen (tried it last night but almost fell asleep after three tracks, seriously; then again, I hadn't slept for 30h...).
   
  Philips group EH90 tubes aren't particularly expensive if you pick odd-labeled ones. There's like an unlimited number of brands you can pick from too (Philips, Mullard, Siemens, Miniwatt, Mazda, Adzam, Valvo, Pope...). Btw, Adzam tubes will almost certainly be the same Belgian M.B.L.E. tubes I'm testing, whereas the other brands like Siemens would be 70-80% Mullards, 10-20% M.B.L.E., 0-10% Misc or mostly Mullards anyway. I have yet to find or see Holland-made EH90 tubes.


----------



## TrollDragon

Thanks Audiofanboy!
   
  I will patiently wait out some Phillips type EH90's on eBay, I am enjoying the 6BY6's right now so there is no rush.


----------



## TrollDragon

I've noticed gibosi mention the gain of various tubes in past messages and I have looked at the spec sheet's but the gain is not specifically listed. Is this a value that has to be calculated?
  I am going to have to dig up some "Tubes for Dummies" PDF's off the net and do a little reading.


----------



## KR500

Quote: 





> Are the ATH - AD900X headphones as comfortable as the AD700?


 
  Mordy;
   
  In a nutshell , yes plus improved pads and nice bass presence, which was a bit too lean in the ATH AD-700's.
  General construction is a step up other than the plug end .
  I think the drivers are better than the 700's although still breaking in at about 25 hours so far
  Comfort and ear ventilation is the major reason I wanted to stay in the AT family.
  I have excellent full range speakers and a class A SET amp for non headphone listening .
  Since the missus is 64 she doesn't necessarily want to hear some types of music in the evening that I do... so the Little Dot works out great while she is chillaxin' with a book or crossword puzzle. Plus in August with fans and AC going it's a little more noise isolation
  Sorry to drift off OP topic some here but I'll post my impressions of trying the Mullard EF92's when I get them next month. They will be my first excursion out of standard EF95 territory with the LD amp


----------



## Audiofanboy

Quote: 





trolldragon said:


> I've noticed gibosi mention the gain of various tubes in past messages and I have looked at the spec sheet's but the gain is not specifically listed. Is this a value that has to be calculated?
> I am going to have to dig up some "Tubes for Dummies" PDF's off the net and do a little reading.


 
   
  Not quite.
   
  Gain or mu is very hard to calculate for pentode/heptodes -non-triodes basically- as it would vary depending on a number of factors. So, it isn't used or usually given for those tubes. A value is sometimes mentioned for cases where the tube (the pentode) or part of the tube (for a heptode) are used in a triode-like way.
   
  It's essentially the voltage gain in a tube. A 6AK5 driver tube (triode-strapped) has a mu of 20, which voltage out is 20x higher than voltage in. Gain is typically used for triodes, or when pentodes are triode-strapped (which is why gibosi, myself or google can give you a mu for, say, a 6AK5 or 6AU6 pentode), but is usually only mentioned in triode datasheets or for pentodes with known triode applications, such as a 6AK5.
   
  Yeah, you'll probably want to do at least some degree of "tube for dummies" or "tube basics" reading at some point. None of it will make sense right away, but it'll help you understand things little by little, and will eventually sink in and allow you to understand just what it is that goes on in there! I know I read a whole bunch of stuff in the last year or so, and all of it took months for me to really "get" and start using.


----------



## mab1376

Quote: 





audiofanboy said:


> Alright! Finally back in my -primary- country, and almost back in the game now that I have my amp back; if it weren't for the fact that I'm soooooo tired...! Jetlag is one the thing I just can never get used to even after traveling for most of my life...
> 
> But fear not, I _will_ end up giving those final impressions on Belgian and UK EH90 tubes. I just strapped the tubes back in and am warming the amp up for a good listen (tried it last night but almost fell asleep after three tracks, seriously; then again, I hadn't slept for 30h...).
> 
> Philips group EH90 tubes aren't particularly expensive if you pick odd-labeled ones. There's like an unlimited number of brands you can pick from too (Philips, Mullard, Siemens, Miniwatt, Mazda, Adzam, Valvo, Pope...). Btw, Adzam tubes will almost certainly be the same Belgian M.B.L.E. tubes I'm testing, whereas the other brands like Siemens would be 70-80% Mullards, 10-20% M.B.L.E., 0-10% Misc or mostly Mullards anyway. I have yet to find or see Holland-made EH90 tubes.


 
  I have the Valvo variant which has amazing 3d imaging, instrument separation could be better but still acceptable.
   
  this is with a 2-7 strap, I'm going to try the 1-7 strap this week as well to compare.


----------



## gibosi

Quote: 





trolldragon said:


> Are the Haltron 6CS6 from Japan on par with the EH90's you linked?


 
   
  To the best of my knowledge, Haltron did not manufacture tubes. They merely purchased tubes, probably the cheapest deal they could find, and relabeled them for sale under their own brand. So it often takes a bit of sleuthing to figure out which company manufactured a particular Haltron tube. In the case of a Haltron 6CS6 made in Japan, I have no experience with this tube and don't recall anyone posting anything. Maybe one of our lurkers has this tube and would be willing to give us some feedback.


----------



## foreign

How long do new tubes take to burn in got some mullards but they don't sound as good as the stock tubes from my little dot mk3 amp. I know a burn in is required just curious.


----------



## gibosi

Quote: 





foreign said:


> How long do new tubes take to burn in got some mullards but they don't sound as good as the stock tubes from my little dot mk3 amp. I know a burn in is required just curious.


 
   
  I typically burn tubes in for 20 to 30 hours. However, some tubes appear to take longer, as much as 50 hours, or more, to finally stabilize.


----------



## TrollDragon

Quote: 





audiofanboy said:


> Not quite.
> 
> Gain or mu is very hard to calculate for pentode/heptodes -non-triodes basically- as it would vary depending on a number of factors. So, it isn't used or usually given for those tubes. A value is sometimes mentioned for cases where the tube (the pentode) or part of the tube (for a heptode) are used in a triode-like way.
> 
> ...


 
  Thanks, l will do some reading for sure, at least get some basics down.
   
  Quote: 





gibosi said:


> To the best of my knowledge, Haltron did not manufacture tubes. They merely purchased tubes, probably the cheapest deal they could find, and relabeled them for sale under their own brand. So it often takes a bit of sleuthing to figure out which company manufactured a particular Haltron tube. In the case of a Haltron 6CS6 made in Japan, I have no experience with this tube and don't recall anyone posting anything. Maybe one of our lurkers has this tube and would be willing to give us some feedback.


 
  Thanks, they were for sale fairly cheap, which was the reason I asked.


----------



## mordy

Hi KR500,
   
  Your post made me laugh - my wife is the same age and she thoroughly dislikes my musical taste (20's classic jazz). My solution is to close the door to my man cave and crank up the volume.
   
  However, sometimes i have family members or guests over, and then I have to resort to the headphones which I find less satisfying. Was able to buy the ATH AD700 as B stock for $65 a few years ago. The best price I could find on the ATH AD900X is around $190 which is a drop high - looking for a better deal.
   
  About tubes I find it fascinating that some European vendors seem to think that US made stuff is the best, and some Americans seem to think that the European stuff is the best.
   
  Dollar for dollar the best current deal is RCA 6DT6/6DT6A (1/7 strap). The more I listen to them, the more I like them. Go Detox!


----------



## mordy

Here is the little I found about Haltron vacuum tubes. Seems very clear that it was a British re-brand company and that the tubes could come from anywhere.
   

 *Haltron ( = Hall Electric Ltd ) imported crummy valves from
 Western Europe, mainly West Germany, an re-badged them.*
 *Haltron was a tube marketer rather than a manufacturer,
 similar to Xaerix, National (OK, National did make
 SOME things) , IEC, Calvert Electronics ("Gold Monarch"), Pinnacle
 and Realistic.

 Haltron sold tubes from all over. As with other marketers,
 if you're smart and observant enough to be able to determine
 who actually made the tube, you may find some hidden
 treasures amongst Haltron tubes. 30 years ago, Haltron
 didn't give a flying hoot who made what tube so long as
 the price was right, and back then, not too many cared
 so long as it wasn't WE or Eimac. Of course the reverse
 applies, too, they might be Eastern European or Japanese,
 but if the price is right, they might still be a good deal.*
   
*"Haltron"-branded tubes could be almost anything, but are usually of European origin. *
   
  Now u know more than most about Haltron tubes LOL........


----------



## TrollDragon

The google-fu is strong in mordy!
Thanks!


----------



## Audiofanboy

I need a pair of those Detox tubes, just to pull myself away from those evil heptodes for a few minutes...
   
  I was trying to *not* give early impressions of comparing the Mazda M.B.L.E. and Mullard Blackburn EH90, but I just can't wait that long or for an x0h burn-in. So, yeah, here are a few impressions of these two pairs compared to each other and to the "Haltmens" Haltron 6BE6 that are like the Siemens _EK90_ -I never got to the point of actually looking for Siemens _EH90_, going on vacation kind of dropped me from being one of the cool kids around here lol!
   
  - *M.B.L.E. EH90 unstrapped*: excellent overall, clearly on the UK side of the Euro-Tubiness Continuum (R), ETC for short; very natural with vocals and mid-centric music, almost euphonic at times. Soundstage is appreciably large but not weirdly so, treble and mids have a pleasant tubey warm ring to them, and are very detailed, could use a drier or slightly speedier attack; bass, which I recalled to be thumpy and deep, just doesn't seem to hit that hard listening with my refreshed ears, excellent and just a tad warm. Shortfall of these tubes: not good for anything hard or electronic. Eric Clapton, Fleetwood Mac or Fiona Apple will sound gorgeous and true-to-life, but any kind of Hot Chip, Daft Punk or whatever hard candy floats your boat just doesn't sit well with these.
   
  - *M.B.L.E. EH90 1-7 strapped*: *excellent overall*, very similar to above, noticeably louder, bass possibly lighter (may explain my different impressions from before actually), as good or better than unstrapped; but seems even worse with any non-acoustic music for a strange reason. I would use either setting without worry, so probably unstrapped by safety and laziness.
   
  - *"Haltmens" 6BE6* (*Siemens EK90*, should sound similar to prized Siemens EH90 when unstrapped, as same exact tube essentially) *unstrapped*: *excellent overall*, dry and detailed like good tubes should be, excellent treble and micro-detail, very good but not huge soundstage. Bass is very nice but could be a bit more emphasized, dry and thumpy anyway, which is good. Treble is probably what these tubes do best and where the "quality" and toe-tapiness lie; these render upper end detail on well-recorded tracks in an excellent way. Mids are excellent imo, but are, indeed, way over on the sterile side. Now, I don't mind that, because the tubes sound balanced that way, but that does throw them way on the other end, the German end, of the ETC (R) -not as much as, say, Telefunkens, but pretty far imho. These tubes are excellent and a riot to listen to on hard electronic tracks, but become less and less enjoyable the softer your music gets. I remembered these as being more versatile and immediately pleasing than they sound to me now. Note that I did not enjoy these tubes strapped in any way.
   
  - *Pope EH90 "Made in Holland"* (a lie, they are B coded, so made by *Mullard *in *Blackburn*, Mullards basically) *unstrapped*: *excellent, period...?* OK, now I have less than 2 hours on these so bear with me; I just don't have the time for marathon burn-in session like everybody else is doing lol. These should have sounded the same as the M.B.L.E EH90 (Philips group, same design with minor differences), but they don't -actually they sound closer to how I _remember_ the M.B.L.E. sounding- and they sound great. Being Mullards, these should have been pinned to the wall on the UK side of the UTC (R), but they aren't, they're actually somewhere in the middle, closer to Holland standards -which is interesting since they're "Made in Holland" and since "Pope" tubes are supposed to be Philips Heerlen overproduction, but nevermind that. These tubes have the same large and realistic soundstage as the Belgians but just sound less "soft and tubey". Treble is and mids are excellent and detailed but never any kind of sibilant and also very natural sounding. Bass is _hard-hitting_ and _deep_, but it's always a tough call before burn-in; it *seems* like it will be _excellent_. Anyway, I'll wait the usual 30h to make a call, but these might be the best of three pairs, at least in some regards. They just do all genres well, and that's kind of a necessity for me -I just can't change tubes twice a day everyday, that's just just not how things work.
   
  All three pairs are excellent though, it's just that that last one is showing more promise than other two; It may still not end up being ideal in the end.


----------



## KR500

Quote: 





> my wife is the same age and she thoroughly dislikes my musical taste (20's classic jazz)


 
  Actually my wife has no issues with my love of 20's through 50's jazz . She likes Gennet label recordings , Artis Shaw , Adrain Rollini Charlie Christian, but not much interested when I veer into the Buddy Miles Express , hendrix or Family classic rock type territory.
   
  Thanks for the tip on your preferred tube . I'll look for some of those


----------



## hypnos1

Quote: 





audiofanboy said:


> I need a pair of those Detox tubes, just to pull myself away from those evil heptodes for a few minutes...
> 
> I was trying to *not* give early impressions of comparing the Mazda M.B.L.E. and Mullard Blackburn EH90, but I just can't wait that long or for an x0h burn-in. So, yeah, here are a few impressions of these two pairs compared to each other and to the "Haltmens" Haltron 6BE6 that are like the Siemens _EK90_ -I never got to the point of actually looking for Siemens _EH90_, going on vacation kind of dropped me from being one of the cool kids around here lol!
> 
> ...


 
   
  Hi AFB. Full marks for getting back in the saddle while still 'recuperating' from the travel. Good luck with the catch-up!
   
  Nice tube comparison - even though it is early stages (but you do seem to be able to get a fairly good flavour of a tube before most of us lesser mortals, lol). Am glad it looks as though there COULD be a discernible difference between the M.B.L.E.s and the Blackburns, and that I wasn't hallucinating!! Whatever, yes, both are wonderful. I think you will be even more impressed after 30-50 hrs...(just how many hours do you have in a day?!!!).
   
  Keep up the good work...


----------



## MIKELAP

Quote: 





gibosi said:


> To the best of my knowledge, Haltron did not manufacture tubes. They merely purchased tubes, probably the cheapest deal they could find, and relabeled them for sale under their own brand. So it often takes a bit of sleuthing to figure out which company manufactured a particular Haltron tube. In the case of a Haltron 6CS6 made in Japan, I have no experience with this tube and don't recall anyone posting anything. Maybe one of our lurkers has this tube and would be willing to give us some feedback.


 
  I have those tubes didnt touch them yet they are part of the backlog  but ill start burnin them in now


----------



## Oskari

Quote: 





mikelap said:


>


 
   
  Quote: 





mikelap said:


>


 
   
  Please take a good comparative _look_ at these!


----------



## MIKELAP

Quote: 





oskari said:


> Please take a good comparative _look_ at these!


 
  you read my mind!


----------



## kvtaco17

Lookie what came today! (been a little over a month)
   
  the BVA on the back appears to be a tube type? In very faint print on both tubes is a date code that reads "GE1 B8H3" (this doesn't jive with the Mullard coding scheme, or I'm just sleep deprived.. X is smudged looks like 4)
   
  Builds looks identical to the Valvo I have on hand (same getter, internal wiring and components), except the glass edges aren't completely smooth and the glass feels thicker.
   
  Burning them in now... I will report back when I've tested them strapped.
   
*EDIT @1hr*
   
  At the start these sounded really congested... constipated really... they are opening up, bassy, mids are sweet and treble is detailed but lacks a little sparkle... they definitely sound like the Valvo EH90 I originally tested... looking back my notes even sound very similar at the 1 hr mark. I'll continue to burn these in for about 10 hours (that's how long it took the Valvo's to stabilize) and report back on my observations tomorrow. (tubes unstrapped EF95 setting for bass line tests) Also noteworthy is that this pair does not suffer from the microphonic issues that the Valvo's had.


----------



## Acapella11

Wow AFB, nice impressions galore. When you feel confident enough to rank them, please do.
   
  Today, I received two Valvo EH90, most likely produced in the same factory (Production codes GE1 B4F3 on one GE1 B4XX on the other (XX is not readable). I have just blitzed through the straps. Please, you EH90 owners out there, do try 6/7 = EH91/92 if you can find the time, you might be surprised...


----------



## gibosi

Quote: 





kvtaco17 said:


> the BVA on the back appears to be a tube type? In very faint print on both tubes is a date code that reads "GE1" (this doesn't jive with the Mullard coding scheme, or I'm just sleep deprived)
> 
> Builds looks identical to the Valvo I have on hand (same getter, internal wiring and components), except the glass edges aren't completely smooth and the glass feels thicker.


 
   
  BVA = British Valve Association. 
   
  GE = EH90
  1 = change code.
   
  Just below GE1, in a second line, you should find the date code, 3 or 4 characters. For example B4F3. I suggest you use a magnifying glass with very bright lighting. I have found that if I lay the tube on a white piece of paper. the etched characters stand out a bit better. 
   
  Edit: Oh "GE1 R8X3"
   
  R is probably B. As the most likely candidates for the Philips EH90 are B = Blackburn, D = Hamburg and L = Belgium.
  8 = 1968. R = Mitcham and I have never seen an EH90 from that factory....
   
  X = A letter between A - L for one of the 12 months
   
  3 = the third week of that month.


----------



## kvtaco17

Quote: 





gibosi said:


> BVA = British Valve Association.
> 
> GE = EH90
> 1 = change code.
> ...


 
  Thanks for the tip! Using a white background instead of my monitor helps... GE1 B8 lol I dunno OMG What 3 is what it looks like... probably a worn off H


----------



## MIKELAP

Been listening to Siemens 6cs6  and Haltron 6cs6 the Siemens have 30 hours on them and the Haltron 4hours so what i did i tested the 2 pairs on ef95 and ef 92 settings personnally i like better the EF92 setting they seem to be a bit cleaner sounding bass quality and quantity to me sounds similar and i swapped them several times its really not a day and night all the tubes tested recently to me have very subtile differences not being an expert and earing not being like it use to its not easy .next ill try the 1-7   strap with both


----------



## TrollDragon

Thanks MIKELAP, I think I'll grab a pair from the seller in Toronto... It won't be a 3 week wait...


----------



## MIKELAP

Was thinking of using Littledot mk3 as preamp with my Pioneer SX750 and i was told against doing this because of possible dc current surge any body here knows if the caps are dc blocking caps 
   this is from the vintage thread  .Thanks


----------



## TrollDragon

mikelap said:


> Was thinking of using Littledot mk3 as preamp with my Pioneer SX750 and i was told against doing this because of possible dc current surge any body here knows if the caps are dc blocking caps
> this is from the vintage thread  .Thanks


Hey MIKELAP, I was just reading about that over on DIY Audio.

The Pre Out of the LD I guess is very poorly designed. What I gather from reading is if the LD blows a tube there can be over 100V DC dumped out the Pre Out jacks, I had a look at the schematic for the SX750 and there are caps on the Aux In at the input opamps but it is a low value and only 25V.

So this is the dilemma, you can hook it up and as long as you don't have a bad tube all is good and it could last for years. The moment the tube goes bad and it starts dumping out DC that little 25V cap is not going to save the the SX750, smoke will roll and most likely your speakers with it. 

What some have done is installed blocking caps on the inputs inside of their speaker amp as there is no room in the LD. They install 500uf 250V caps on the input line which will safeguard against a failure, but these caps are huge and $40 each.

It might be something to consider, but I would consult with someone who has more electronics knowledge than I have.

A Russian Roulette with your speaker system IMHO is just not worth the chance.


----------



## MIKELAP

Quote: 





trolldragon said:


> Hey MIKELAP, I was just reading about that over on DIY Audio.
> 
> The Pre Out of the LD I guess is very poorly designed. What I gather from reading is if the LD blows a tube there can be over 100V DC dumped out the Pre Out jacks, I had a look at the schematic for the SX750 and there are caps on the Aux In at the input opamps but it is a low value and only 25V.
> 
> ...


 
  Thanks alot for the input wont risk it then


----------



## MIKELAP

Here are the pictures gibosi on the tubes i marked the 2 and 4 pins according to page 77 PIN NUMBERING -BOTTOM OF TUBE VIEW - haltrons first 3picture then Siemens 3 pictures .if you need other views of the tubes let me know


----------



## MIKELAP

Quote: 





mikelap said:


> Was thinking of using Littledot mk3 as preamp with my Pioneer SX750 and i was told against doing this because of possible dc current surge any body here knows if the caps are dc blocking caps
> this is from the vintage thread  .Thanks


 
   
  Quote: 





trolldragon said:


> Hey MIKELAP, I was just reading about that over on DIY Audio.
> 
> The Pre Out of the LD I guess is very poorly designed. What I gather from reading is if the LD blows a tube there can be over 100V DC dumped out the Pre Out jacks, I had a look at the schematic for the SX750 and there are caps on the Aux In at the input opamps but it is a low value and only 25V.
> 
> ...


 
  I sent an email to David zhezhe of Littledot regarding dc coupled amps  and this is his reply :      

  The Little Dot MK III s not recommended to be used with DC coupled power amplifiers, which sounds like your SX750 is.

 Best Regards,
 David
  
 [size=10pt] - davidzhezhe[/size]


----------



## Audiofanboy

Quote: 





mikelap said:


> I sent an email to David zhezhe of Littledot regarding dc coupled amps  and this is his reply :
> 
> The Little Dot MK III s not recommended to be used with DC coupled power amplifiers, which sounds like your SX750 is.
> 
> ...


 
   
  This being said, I've used my MK IV SE countless times as a preamp with Tripath based power amps that most definitely _are _DC coupled.
   
  I know this for a fact since when I use them as actual bridged power amps -"mono blocks" as they say, with no volume control- and the LD plugged to them and running, I can _hear_ the DC offset, and it is _loud_, _dangerously loud_. Of course, it is, I mean, even 10-20 mV of offset straight into a 150W power amp with no caps would end up being loud on even slightly efficient speakers.
   
  But if I use the integrated volume pots on the power amps -which I need to as otherwise I have about a mm of volume tracking using the LD pot- at, say, a quarter of the potentiometer, then the noise level -amplified DC offset- is OK, but not totally gone.
   
  If it really gets bad, the power amps just switch off anyway, so what I'm doing isn't risky _per se_, but I can't really say it's that reassuring either... I do get great sound plugging the amps and preamp that way, as there's almost nothing on the signal path.
   
  Mikelap, great pics of both tubes! So, can we conclude that _they're the same_? Have we solved the Siemens mystery? Are those foreign Siemens just Japanese Matsu_schiit_a tubes?
   
  If they are, then I've got some ebay browsing to do lol!


----------



## gibosi

Quote: 





mikelap said:


> Here are the pictures gibosi on the tubes.......


 
   
  This is very interesting...  It appears that Oskari's hunch was correct. You can see on both of these tubes that grids 2 and 4 are connected with a little strap above the top mica, on the left hand side of the tube. Also, the plates, seam and the location of the holes is the same on both of these tubes. They look to be identical. However, judging from the boxes and the etching on the tubes, the Siemens appear to be 1960s European production, while this Haltron appears to be 1970s or later. So while I do not think that the Siemens were manufactured in Japan, my best guess is that manufacturing equipment that was once used to produce these Siemens was relocated from Europe to Japan, and was then used to produce what are essentially the same tubes. Anyway, I would not be at all surprised if these tubes sound virtually the same as the Siemens and the Zaerix. Very interesting!!


----------



## Audiofanboy

Quote: 





gibosi said:


> This is very interesting...  It appears that Oskari's hunch was correct. You can see on both of these tubes that grids 2 and 4 are connected with a little strap above the top mica, on the left hand side of the tube. Also, the plates, seam and the location of the holes is the same on both of these tubes. They look to be identical. However, judging from the boxes and the etching on the tubes, the Siemens appear to be 1960s European production, while this Haltron appears to be 1970s or later. So while I do not think that the Siemens were manufactured in Japan, my best guess is that manufacturing equipment that was once used to produce these Siemens was relocated from Europe to Japan, and was then used to produce what are essentially the same tubes. Anyway, I would not be at all surprised if these tubes sound virtually the same as the Siemens and the Zaerix. Very interesting!!


 
   
  OK, should have seen this coming... Just typing "Siemens Matsu_schiit_a" in google, there seems to be an obvious link between the two companies, at least historically and for component manufacturing. We may very well be pretty close to reaching a conclusion on the "Siemens" tubes.


----------



## siles1991

hey guys havnt been around for awhile still waiting for my mkiv se >.<!! in my collection atm is just Sylvania 5915 and the TS 6AH6WA, looking to find new tubes to add to my collection. Any really good tubes that can be found atm?
   
  edit: oh yeah and the valvo EH90 as well in my collection


----------



## duncan1

An -EK90 is a hexode tube used in the front end of tube radio receivers.As  such having multiple grids it is more noisy than a triode tube - grids  2+4 are strapped together for use in radio design circuits One of the reasons for this is electron flow which has to go through multiple grids  some electrons bouncing off and creating noise . That is why communication receivers  [tube] usually had 1 or 2 RF stages before the FC tube so that the signal to noise ratio was large and so the effect of the noise was at a much lower level  Also in these communication receivers a lot of the time the FC tube [which carries out 2 functions] was separated and the oscillator was usually a separate tube..I wouldn't use one as the input to any tube amp.Special service tubes-used by government and military forces were made to a much higher standard than the normal commercial issues.they also had longer lives due to the cleaner conditions they were made under. Had rigid inspection and testing.


----------



## gibosi

Quote: 





siles1991 said:


> hey guys havnt been around for awhile still waiting for my mkiv se >.<!! in my collection atm is just Sylvania 5915 and the TS 6AH6WA, looking to find new tubes to add to my collection. Any really good tubes that can be found atm?
> 
> edit: oh yeah and the valvo EH90 as well in my collection


 
   
  The current "tube-of-the-moment" is the RCA 6DT6. And usually these are very cheap!


----------



## siles1991

Quote: 





gibosi said:


> The current "tube-of-the-moment" is the RCA 6DT6. And usually these are very cheap!


 
  would the 6DT6A's in this link be RCA's?
   
http://www.ebay.com.my/itm/NIB-new-vacuum-tubes-6D4-6DB5-6DC6-6DC8-6DE6-6DE7-6DR7-6DT5-6DT6A-RCA-6DT8-6DX8-/390478347313?pt=LH_DefaultDomain_0&var&hash=item5aea52bc31&_uhb=1#ht_500wt_923


----------



## gibosi

Quote: 





siles1991 said:


> would the 6DT6A's in this link be RCA's?
> 
> http://www.ebay.com.my/itm/NIB-new-vacuum-tubes-6D4-6DB5-6DC6-6DC8-6DE6-6DE7-6DR7-6DT5-6DT6A-RCA-6DT8-6DX8-/390478347313?pt=LH_DefaultDomain_0&var&hash=item5aea52bc31&_uhb=1#ht_500wt_923


 
   
  Not necessarily...  It is likely that he has more than one brand in stock. You will have to send the vendor a message asking if he has two RCA.


----------



## gibosi

Tung Sol 6DT6
   
  In order to get a handle on the sound of this tube, I pulled out the venerable Tung Sol 6485 to compare. The TS 6485 was configured in the EF95 2-7 strapping (we have no other choice as this is the only way we can use this tube in our Little Dots) and the TS 6DT6 in the EF95 1-7 strapping. The TS 6DT6 has the classic TS 6485 sound, with deep strong base, warm vocals and clean and detailed highs. The most obvious difference is in the sound stage. The TS 6DT6, similar to the RCA 6DT6, has a very wide sound stage, noticeably wider than the TS 6485. In my mind, with the wider sound stage, it is an improved version of our beloved TS 6485.
   
  So if you like the sound of the TS 6485 (and/or TS 6AH6W/A), then the TS 6DT6 will very likely bring a smile to your face. Recommended.
   
  Unfortunately, these are somewhat scarce, but they do turn up every so often, and they are not expensive. I paid $12 including shipping for my pair.


----------



## TrollDragon

Quote: 





duncan1 said:


> An -EK90 is a hexode tube used in the front end of tube radio receivers.
> <SNIP>
> I wouldn't use one as the input to any tube amp.


 
   
  I thought, in my very limited knowledge about tubes that an EK90 was a *Heptode* with seven electrode's as opposed to a *Hexode* which has six.
And we should not be using these? But for the past XX number of pages here, everyone has been getting great results with the EK90's and EH90's.


----------



## mab1376

Whats the difference between the EH90 with ribbed plates vs the smooth plates?
   
  I have the Valvo smooth plates and so far like them a lot.


----------



## duncan1

TrollDragon-Its got 4 grids[if you count 2+4 as separate] According to my information its a Hexode  a Heptode has 5 grids maybe things are different in the US? -Checked out a -EH90-dual control heptode- its got 5 grids I am taking this from the official Mullard Data book I have several-ECH81 [triode] Heptode -5 grids-not counting the triode.section. Every UK data book on tubes checks out the same as me . Maybe the States add on another element?? If people are happy with them then I am happy I would rather be subjective on this as it is what people hear with their own ears rather than being told not to.by objectives. I am on your side here.  If people cant hear any noise well thats okay  maybe its because  tube radio front ends deal in microvolts of a signal and that is well below what the music signal is on your equipment. But a triode would be clearer as it has a lower noise floor.---Found a European tube book-Radio tube Vade-Mecum lists the Hexode as -6 and the Heptode as-7 so they are adding on the plate and cathode elements but it doesnt change the technical name of the tubes.


----------



## gibosi

Quote: 





duncan1 said:


> TrollDragon-Its got 4 grids[if you count 2+4 as separate] According to my information its a Hexode  a Heptode has 5 grids maybe things are different in the US? -Checked out a -EH90-dual control heptode- its got 5 grids I am taking this from the official Mullard Data book I have several-ECH81 [triode] Heptode -5 grids-not counting the triode.section. Every UK data book on tubes checks out the same as me . Maybe the States add on another element?? If people are happy with them then I am happy I would rather be subjective on this as it is what people hear with their own ears rather than being told not to.by objectives. I am on your side here.  If people cant hear any noise well thats okay  maybe its because  tube radio front ends deal in microvolts of a signal and that is well below what the music signal is on your equipment. But a triode would be clearer as it has a lower noise floor.---Found a European tube book-Radio tube Vade-Mecum lists the Hexode as -6 and the Heptode as-7 so they are adding on the plate and cathode elements but it doesnt change the technical name of the tubes.


 
   
  There seems to be a fair amount of confusion about this... But if you look at the pin diagram, the EK90/6BE6 is indeed a heptode (*HERE*) There are five grids plus the cathode and plate which totals 7 electrodes. It has the same exact pin diagram as the 6BY6/E91H and the 6CS6/EH90, again five grids plus the cathode and plate. However, the fact that grids 2 and 4 are internally connected means that in practice there are only four grids, so it would seem that sometimes these are classified as hexodes.
   
  As to noise associated with multiple grids, since we convert heptodes, hexodes and pentodes into triodes for use in the Little Dot, this is not an issue. Depending on the configuration, the extra grids are tied to the plate, the cathode and/or the main control grid so that in the end, there is only one grid. And further, in my experience these tubes are just as quiet as a 6AV6/EBC91, which is a true triode. So if they are in fact measurably noisier, it is below our hearing threshold.


----------



## TrollDragon

Thanks gibosi for some clarification on this Hep/Hex confusion.

Now my 6BY6 with the square getter I am just warming up to test them out.

Square vs Round, would this have been a different factory, newer design spec, cost thing as to why the different getter shape on the same tube type?

Or don't mean jack, just shutup and go listen to some tunes...


----------



## kvtaco17

*EH90 VS 6DT6*

 I have been rolling tubes like a madman lately, and I figured I'd share my notes on what are in my opinion the best tubes for the Little Dot 1+ we all so love!

*Setup*

 FLAC (PC)> USB ODAC>Little Dot 1+> Grado PS500/sr225i/AD900x

*Tubes used*

 RCA 6DT6A (1/7 strapped everything else is meh)

 Valvo EH90

 EdiSwan EH90

 Mullard EH90

 All burnt in a minimum of 10 hours, EH90's EF95 setting  unstrapped, 6/7 and 1/7 strapped (noted in review)

 Now the EH90's almost all sound the same, probably because Mullard, as we all know made a lot of tubes for other companies! There are some slight variences in sound between the tubes I have, I'll chalk that up to age and them being in different states of wear.
   
  * denotes my preference

*Songs used*
  
 Katie Melua - Moonshine    





   
*EH 90*
   
  EF95 Warm, detailed bassy, amazing mids, above average + very round and well defined sound stage... The Valvo's/Mullard's were and still are my favorite EH90 tube, but the Ediswan's seem to have tighter bass and slightly better clarity in the lower treble regions. On this song these tubes really work well with any of my Grado cans. My AD900x takes on an odd tonality here. Honky, blurred ... The sound stage is smaller then this can is capable of. 
   
  1/7 Preferred, less/tighter bass, more focus. AD900x no longer sounds weird. Added sparkle. Gives the illusion of more sound stage.
   
*6DT6* *
   
  1/7 Huge sound stage very deep, wide and tall (not quite as precise ad the EH90). Slightly warm... good tight bass very detailed, sparkle! These things are amazing on this track! They easily trick you into forgetting about the headphones you are wearing.
   
 Jane Monheit Taking A Chance On Love    




   
*EH90 **
   
  Unstrapped. Intimate and warm... excellent detail, feels like your front row at the club feeling every word.
   
  1/7 No... just no. Thin, boring...
   
*6DT6*
   
  Sound stage seems a little too big. Jane seems like a large part of the center image (not very off, but enough to notice) instead of a single voice. Warm, detailed. The AD900x exaggerates the center image issue. Even with that these are still very musical.
 Dave Matthews Band - Warehouse (Folsom Field)




   
*EH90*
   
  Details details DETAILS! all 3 of the EH90's on hand are very detailed! (say detailed enough yet?) Good sound stage, very accurate placement. (Do yourself a favor and get this in loss less)
   
*6DT6**
   
  See above, add ginarmous sound stage. Enjoy
 Loreena Mckennitt - Penelope's Song   




   
*EH90*
   
  Sweet mids and treble... Loreena's voice is extra enchanting!  Listen for the pianos peddles, the occasional cough... the grain of the stringed instruments. Amazing. 
   
*6DT6**
   
  all of the above, but presented in a grander fashion. Your feel the sheer size of the venue. Very natural.
   
 Opeth - Reverie/Harlequin Forest   




   
*EH90*
   
  Detailed, fast deep sound stage. Good sense of balance.
   
  1/7 lean... almost painful depending on cans (sr225i)
   
*6DT6*
   
  Huge sounding, warm, crunchy.
   
  Neither are really better... draw
   
 Megadeth - Looking Down The Cross (remaster)    




   
*EH90**
   
  There's a lot going on in this song... Gar's drumming is energetic and fun, lots of odd guitar work, an almost funk/thrash groove... These 'todes capture the performance like a boss. Intimate but airy. Fast, aggressive, crunchy.
   
*6DT6*
   
  No detail is lost with the exaggerated sound stage BUT that feeling of intimacy and aggression suffers...
   
 Pure Reason Revolution - Apogee    




   
 Pure Reason Revolution - Goshen's Remains   




   
  A double feature!
   
*EH90** (Preferred on Apogee)
   
  Unstrapped Tight impactful bass, glorious mids!
   
  1/7 Fast and detailed, warm, with enough sparkle... bass gets a little lost in the mix... lean...
   
*6DT6** (preferred on Goshen's Remains)
   
  Similarto the above unstrapped... Instruments seem better separated... This one comes down to personal presentation preferences...
   
*Early Conclusions *
   
  These are easily the 2 best tube families out there for Little Dot amps... so far... I will be keeping at least a pair of both families! More to come this weekend (more 6dt6's incoming)


----------



## gibosi

Quote: 





trolldragon said:


> Now my 6BY6 with the square getter I am just warming up to test them out.
> 
> Square vs Round, would this have been a different factory, newer design spec, cost thing as to why the different getter shape on the same tube type?
> 
> Or don't mean jack, just shutup and go listen to some tunes...


 
   
  Keeping in mind that most of these tubes were in continuous production from at least the 1940s through the 1970s and in some cases, even into the 1980s, some thirty, forty or more years, it is not surprising that over such a long time period, internal construction would change, as feedback from the field and new advances in materials and technology made their way back to the factory floor. Square getters were the norm through the 1950s, but slowly gave way to round getters in the 1960s. Of course, there were likely lots of other changes as well, but most are undetectable to the untrained naked eye. In general, the consensus thinking is that newer is better. However, in practice, it is very rare that I am able to hear any difference between the older tubes and newer ones. So I would expect that if you can discern any differences, they will be quite subtle.


----------



## GCooper

I have finished ~40 hours with mil-spec Soviet 6BE6 tubes. Most of my listening has been to 1950's jazz and vocals over FM using a Carver TX11a tuner.
   
  This tube seems to really find its voice with this source material. Sibilance is not unpleasant,  high hat brushwork is crisp and I can hear detail when the musician is fingering clarinets or saxophones. The sound stage does not seem to be as wide as with 6J1P Voskhods. Shall try some DG Sibelius and Lucinda Williams CDs later this week for variety. In any case, the 6BE6 is an improvement over the tubes supplied with the LD III. This is using Alessandro Music Series One headphones. Given how little these tubes cost (at least now) you might want to consider picking up a set or two.


----------



## TrollDragon

Thanks gibosi!


----------



## gibosi

Quote: 





kvtaco17 said:


> *EH90 VS 6DT6*
> 
> I have been rolling tubes like a madman lately, and I figured I'd share my notes on what are in my opinion the best tubes for the Little Dot 1+ we all so love!
> 
> ...


 
   
  It's great to have another voice in the forum , the more the merrier, with different equipment, different ears and a different musical perspective.
   
  A great review!
   
  And especially, thanks for introducing me to some great music I had never heard before!


----------



## kvtaco17

No problem... I pretty much listen to everything! (yeah I'm that guy)


----------



## siles1991

There's a lot of Raytheon and GE 6DT6's floating around in ebay wondering if they might sound good.


----------



## kvtaco17

I'll find out soon!


----------



## siles1991

6DT6A's should work right?


----------



## Audiofanboy

Wow, 13 posts again since last night. I have to get used to that time lag again lol; I had gotten used to posting in the same time frame as North Americans for a few days. Now, I'm back to the "one-way radio effect" where a couple of lost Europeans and Asians post a few posts, I post once or twice, then go to sleep, and when I wake up, bam! 20-some Americans have suddenly posted and won't again until the next day. Strange sensation, come to think of it.
   
  Great work, kvtaco! I guess that's also one more point for the Mullard-ish EH90, huh? I find it interesting that one of the key words that always comes to mind when using the 1-7 strap is "thin" along with "detailed", as it's consistently been my impression on most heptodes. It always sounds great in the beginning, like better than unstrapped, and the next time I switch the amp on with the 1-7 strap, I find it unbearably thin and lifeless... Odd... And probably why I keep going back to the unstrapped setting most of the time. I still think we _need_ to find a way to adapt those heptodes, especially the EH90/6CS6, to tie grid 1 to the cathode and use grid 3 as the exclusive signal/control grid. Now, _that_, would be interesting.
   
  Back from the last page, we had people wondering about the similarity between "Siemens" EH90 and "Japan" EH90. The main reason why _I_ was curious about it is because when Oskari pointed it out -I had thought about it previously when I saw the ebay ad weeks ago but dismissed the idea as being silly- I kinda panicked and bought those tubes, since they were so cheap anyway.
   
  But that's not the interesting part, we've got Mikelap testing those tubes, so he's got us covered. What's interesting is the other tubes I bought along with these from the same seller.
   
  http://cgi.ebay.fr/ws/eBayISAPI.dll?ViewItem&item=200950779149&ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649
   
  "_Please take a good comparative _look_ at these_."
   
  Don't these tubes kind of remind you of something? They remind _me_ of something. Anyway, these were made in Japan and have the same rib plates and holes as the Foreign Siemens tubes, so I'm hoping I bumped in to Siemens-ish 6DT6 tubes. If not, that's fine too, they were dirt cheap and I needed some 6DT6 tubes to test.


----------



## Iron58p

Hi
   
  Has anyone tried GE 6DT6 ? On the box there is 6DT6A
   
  How it sounds ?
   
http://www.ebay.it/itm/6DT6-NOS-NIB-Vacuum-Tube-GE-Canada-Pentode-/200956736530?pt=Vintage_Electronics_R2&hash=item2ec9f47412
   
  Is cheap, but living in Italy shipping cost are not very low


----------



## Audiofanboy

Quote: 





iron58p said:


> Hi
> 
> Has anyone tried GE 6DT6 ? On the box there is 6DT6A
> 
> ...


 
   
  Bear in mind, these won't be the typical US-made GE tubes, but Canada-made tubes, so results might differ.
   
  They are cheap though, no doubting that...


----------



## gibosi

Sylvania 6HZ6 (and probably the Sylvania 6DT6 as well)
   
  In order to get a handle on the sound of this tube, I pulled out the Sylvania 5915 (a premium version of the 6BY6) to compare. For those just joining us, this tube first came to our attention wearing Telefunken paint. Dubbed a "Tele/vania" by Audiofanboy, this is an excellent tube. You can read more about it *here* and *here*
   
  Now my Sylvania 5915 are wearing plain-jane Sylvania paint, not the fancy Telefunken paint, but inside they are identical to the Tele/vanias. 
   

   

   

  For both tubes, I used the EF95 1-7 configuration. Initially, my old ears could not discern any significant difference between these tubes. Both have strong, detailed bass, clear vocals that are less warm than the RCA and Tung Sol, and open and airy highs with great detail. But then I remembered Audiofanboy's comments about the Tele/vania's sound stage on Dreams from Fleetwood Mac's album Rumors, and I added it to my play list. 
   
  While both of these tubes have a very wide sound stage, the 6HZ6 seems to be a bit more two dimensional, whereas, the 5915 is more three-dimensional. With the 6HZ6, vocals are right in your face, but with the 5915, vocals and instruments seem to be a tad bit farther away and there is a very real sense of 3D space. As Audiofanboy put it, a "boundless" sound stage.
   
  So while the Sylvania 6HZ6 is still a very good tube, I have to give the nod to the Sylvania 5915 due to it's superior staging. And if you do not have this tube in your collection, I encourage you to get a pair.


----------



## Iron58p

Are the same Gibosi ?
   
http://www.ebay.it/itm/TWO-5915-SYLVANIA-TUBES-N-O-S-/261257069567?pt=Vintage_Electronics_R2&hash=item3cd42283ff
   
  i have buyed


----------



## duncan1

In answer to you all= A HEXODE has 4 grids+plate and cathode= 6 electrodes. A HEPTODE has 5 grids+ plate and cathode=7 electrodes--You cannot just change an INTERNATIONAL agreed  tube recognition formula that the World of EEs has designated by saying- grids 2+4 are tied together so that make it one -Wrong!  This is in the Mullard/ osram/philips/rca/etc  tube books - Its a FACT


----------



## foreign

I'm currently burning in a pair of Hytrons 6ak5 has anyone tried these before and if so what is your impressions??


----------



## gibosi

Quote: 





iron58p said:


> Are the same Gibosi ?
> 
> http://www.ebay.it/itm/TWO-5915-SYLVANIA-TUBES-N-O-S-/261257069567?pt=Vintage_Electronics_R2&hash=item3cd42283ff
> 
> i have buyed


 
   
  Yes, these are the same. Enjoy!


----------



## Iron58p

I'm very happy 
   
  Thank you very much !!
   
  Really, for the moment i can't enjoi anything, i have only the stock Valvo 6CQ6 ( that i think have problems to be red and not hot ), in my home


----------



## Oskari

Quote: 





audiofanboy said:


> Mikelap, great pics of both tubes! So, can we conclude that _they're the same_? Have we solved the Siemens mystery? Are those foreign Siemens just Japanese Matsu_schiit_a tubes?


 
   
  Actually, I think they were made by Toshiba.
   
  Quote: 





oskari said:


>


 
   
  The type does not appear in the Matsush¡ta catalog but does appear in the Toshiba catalog.


----------



## Audiofanboy

Quote: 





oskari said:


> Actually, I think they were made by Toshiba.
> 
> 
> The type does not appear in the Matsush¡ta catalog but does appear in the Toshiba catalog.


 
   
  Actually, I believe you may be right or at least close.
   
  I read that long Matsu catalog yesterday, and the types (look at the picture of 12BE6 -12V version of a 6BE6- on page 16) that are similar to 6CS6 tubes don't appear to look like those Siemens-ish ribbed tubes. They look like Mullards, and they should, since that's the factory tooling they had bought, or so say many people.
   
  Now, I don't know what the link could have been between Toshiba and Siemens -or if they even was one- or if this is just another story of factory lines and tools going from Europe to Japan in the later tube manufacturing days.
   
  I know that Siemens has had links with Fujitsu though -hence the company name for some products- but I haven't looked at when that dates back to, or whether or not Fujitsu ever made tubes.
   
  Fascinating stuff really.
   
  So, do these 6DT6 tubes I bought look Siemens-ish to you? Or Toshiba-ish I guess?
   
  Edit: Actually, the Japanese 6CS6 and 6DT6 I bought were definitely manufactured by Toshiba, no doubt about that. Just look at a few pictures of similar or remotely close tubes made by Toshiba on google or ebay, and you'll see those ribs on the plates and the same construction. Toshiba made tubes for a bunch of companies in the late tube days apparently: ITT (one 6DT6 on ebay has those ribs), HP (yeah, computer-rated tubes!), and other specific companies like Tektronix (and yes, you can find Tek-matched tubes) or some weird organ-makers and guitar amp makers. Anyway, all the similar tube types I saw look the same.
   
  Now, why do they look the same as _Siemens_ branded tubes?I just can't see the pattern here. That Siemens evantually sold 80%+ Philips tubes and _some odd-ball Japanese tubes_ for the last dozen percents just doesn't make much sense... Not with the cheap East German stuff they could get much closer. That some cheap cheap relabeler Haltron or Zaerix tubes be Japanese makes sense, but that a few lonely German brand tube be does not. Still, unless Toshiba somehow bought some German tube-making gear in the 70s, that's how things are looking right now.


----------



## Oskari

Quote: 





audiofanboy said:


> I read that long Matsu catalog yesterday, and the types (look at the picture of 12BE6 -12V version of a 6BE6- on page 16) that are similar to 6CS6 tubes don't appear to look like those Siemens-ish ribbed tubes. They look like Mullards, and they should, since that's the factory tooling they had bought, or so say many people.


 
   
  True.
   


> I know that Siemens has had links with Fujitsu though -hence the company name for some products- but I haven't looked at when that dates back to, or whether or not Fujitsu ever made tubes.


 
   
  If you are thinking about Fujitsu Siemens Computers, that was much later. Fujitsu Ten certainly made tubes.
   


> So, do these 6DT6 tubes I bought look Siemens-ish to you? Or Toshiba-ish I guess?


 
   
  Indeed.
   

 http://goods.ruten.com.tw/item/show?11091126815870
 http://articulo.mercadolibre.com.ar/MLA-456642910-valvulas-electronicas-6dt6-nos-nib-toshiba-japon-_JM
   


> That some cheap cheap relabeler Haltron or Zaerix tubes be Japanese makes sense, but that a few lonely German brand tube be does not. Still, unless Toshiba somehow bought some German tube-making gear in the 70s, that's how things are looking right now.


 
   
  Why not? It's just business after all.


----------



## Audiofanboy

Quote: 





oskari said:


> True.
> 
> 
> If you are thinking about Fujitsu Siemens Computers, that was much later. Fujitsu Ten certainly made tubes.
> ...


 
   
  I have actually seen TEN -the brand- tubes, and they look different from the Toshiba. I ruled out Fujitsu being a possibility the second I took a look at Toshiba tubes... So minutes after I wrote that comment.
   
  About Siemens supplying Japanese tubes, it just surprises me a bit that they would do so in that time frame. Actual Siemens tubes, like olde worlde Siemens & Halske double triode types are typically well regarded, which leads me to think that the Siemens company had fairly high standards, kind of like Telefunken. So, either it means that by the 70s, they just didn't care much about quality anymore, or it implies that Toshiba tubes were at least OK (Hewlett Packard used them so they couldn't have been horrible; they sound good at any rate), or of course none of these were considerations and it's just basic business as you say. I guess my view of the tube times is the same as my world view: a bit manichean...


----------



## mordy

Did not find much in trying to research Japanese tube manufacturers (Hitachi has not been mentioned yet). However, I found this example of a Toshiba tube radio. IMHO the design is absolutely beautiful.


----------



## Audiofanboy

Quote: 





mordy said:


> Did not find much in trying to research Japanese tube manufacturers (Hitachi has not been mentioned yet). However, I found this example of a Toshiba tube radio. IMHO the design is absolutely beautiful.


 
   
  It's funny you would mention that picture mordy, as, looking at it an hour ago on google, I was just thinking to myself: "_Wow, what a nice looking radio! How long before some manufacturer copies that design on some random neo-retro Apple-like product...?_"
   
  It does look nice though. A lot of people actually buy old radios like this one, empty them from their original contents, and just use the case for some other -assumingly- audio role.


----------



## mordy

"Great minds think alike" - lol


----------



## Acapella11

Quote: 





kvtaco17 said:


> *EH90 VS 6DT6*
> 
> I have been rolling tubes like a madman lately, and I figured I'd share my notes on what are in my opinion the best tubes for the Little Dot 1+ we all so love!
> 
> ...


 
 Great contribution kvtaco17. When going through the first two songs with my Blackburn Valvo EH90 strapped, unstrapped and 6/7, I was quite surprised how differently the songs changed with the straps. And I could exactly understand why you preferred unstrapped over strapped in "Taking a chance on love". I would choose the same. In the first song (Moonshine) 1/7 and also 6/7 do work better. I like when head-fiers post music, because you always discover good new music. Good thing, there were even quite a few tracks to go through.
	

	
	
		
		

		
		
	


	



 My impression is that the EH90s are a bit lesser ambience tubes but rather have their strengths in detail and tonality. I haven't heard the 6DT6 yet but they seem to go more into the Siemens EK90 (black bottom) direction, which I have as in they are a tad warmer and give a good spatial impression. If this is the case, then these will shine in occasions where the recording is favourable towards the perception of the room and the EH90s play out better when the room itself doesn't really come out that well but it is rather about the more forward placed instruments / singer. Just a consideration.
  
  
 Mordy, how do your power tubes along? Just curious since you had them already a while.
  
  
 Oh, one more recent finding. When going back to the special quality 6BE6 tubes, I kind of re-discovered the Sylvania JAN 5750. I didn't like them much on my old setup with the HE-500 and a darker cable. If your setup is bright enough to to fit a really dark tube, then these Sylvanias are highly recommended. Amazing imaging and extremely large stage. Very well articulated bass. One of best instrument separation I have heard. 1/7-strapping opens them up but makes them also sound more forward, such that you lose ambience. Seriously good, dark tubes.


----------



## kvtaco17

The Sylvania 6DT6's came in today! Burn in starts now!
   

   
  Initial impressions (1hr of run time) are similar to the RCA's but with less bass and maybe the illusion of better treble detail, and a better focused sound stage.
   
*EDIT*
   
  The bass showed up just short of 3 hours... Very similar to the RCA's, with a touch more treble.


----------



## kvtaco17

Quote: 





acapella11 said:


> Great contribution kvtaco17. When going through the first two songs with my Blackburn Valvo EH90 strapped, unstrapped and 6/7, I was quite surprised how differently the songs changed with the straps. And I could exactly understand why you preferred unstrapped over strapped in "Taking a chance on love". I would choose the same. In the first song (Moonshine) 1/7 and also 6/7 do work better. I like when head-fiers post music, because you always discover good new music. Good thing, there were even quite a few tracks to go through.
> 
> 
> 
> ... 

 I prefer it when people share their content used when they do audio reviews... it makes the whole process of accessing what the other person is hearing much easier.


----------



## siles1991

quite tempted to get some valvo EH90's  also I found a seller who sells RCA 6DT6A's for 2USD a piece


----------



## kvtaco17

Quote: 





siles1991 said:


> quite tempted to get some valvo EH90's  also I found a seller who sells RCA 6DT6A's for 2USD a piece


 
  How about I sell you a starter set lol

   
  I accidental bought 2 sets of Sylvania's and will probable only keep 1


----------



## siles1991

Quote: 





kvtaco17 said:


> How about I sell you a starter set lol
> 
> 
> I accidental bought 2 sets of Sylvania's and will probable only keep 1


 
  lol interested in the sylv and the valvo how much would they be? Pairs right?


----------



## kvtaco17

Quote: 





siles1991 said:


> lol interested in the sylv and the valvo how much would they be? Pairs right?


 

 Yes pairs, I dunno was gonna list the whole lot for $25 plus shipping. The Valvo I have an additional tube coming because one of the pair is fairly micro phonic, the replacement should be here soon.


----------



## siles1991

Quote: 





kvtaco17 said:


> Yes pairs, I dunno was gonna list the whole lot for $25 plus shipping. The Valvo I have an additional tube coming because one of the pair is fairly micro phonic, the replacement should be here soon.


 
  mm price is quite steep haha I live in malaysia so i dont think the "shipping" would cover international xD. I'll think about it.


----------



## kvtaco17

Quote: 





siles1991 said:


> mm price is quite steep haha I live in malaysia so i dont think the "shipping" would cover international xD. I'll think about it.


 
  Oh man, the shipping would be pretty rough...


----------



## kvtaco17

1st class via USPS would be about $12 USDA so not horrid, but not great.


----------



## Advil

I got some new Svetlana 6c19 tubes coming in and pairing them with mullard 161's for my LD II++ -- I know it's an older amp but should this do well with a q701?


----------



## foreign

The Hytrons 6ak5 have really impressed me so far the soundstage is nice an airy, wonderful depth and extension. I've only had about 5hours of burn in so they are getting better by the hour


----------



## kvtaco17

Quote: 





foreign said:


> The Hytrons 6ak5 have really impressed me so far the soundstage is nice an airy, wonderful depth and extension. I've only had about 5hours of burn in so they are getting better by the hour


 
   
  Quote: 





advil said:


> I got some new Svetlana 6c19 tubes coming in and pairing them with mullard 161's for my LD II++ -- I know it's an older amp but should this do well with a q701?


 

 Please keep up posted on your impressions! (My Svetlana's should be here next week BUT I'll be in Devils Lake... 7 hours away from them... for 2 weeks...


----------



## Advil

Quote: 





kvtaco17 said:


> Please keep up posted on your impressions! (My Svetlana's should be here next week BUT I'll be in Devils Lake... 7 hours away from them... for 2 weeks...


 
  well i'll be waiting for a while since i ordered from ebay and they're shipping from eastern europe to texas! my amp is pretty old and i'm hoping it holds up to such a difficult to drive headphone. i'm worried but hopeful!


----------



## kvtaco17

Quote: 





advil said:


> well i'll be waiting for a while since i ordered from ebay and they're shipping from eastern europe to texas! my amp is pretty old and i'm hoping it holds up to such a difficult to drive headphone. i'm worried but hopeful!


 
  It'll be ok! lol
   
  I rant my DT990's  (250 OHM) on mt 1+ and it was passable.


----------



## foreign

kvtaco17 said:


> Please keep up posted on your impressions! (My Svetlana's should be here next week BUT I'll be in Devils Lake... 7 hours away from them... for 2 weeks...



I will give them a good 20+ hours of burn in then give an update.


----------



## Edgard Varese

Re. the 6DT6... is anyone using a brand other than RCA?  The RCAs are looking a bit scarce at the moment (we've probably bought them all up!).


----------



## kvtaco17

Quote: 





edgard varese said:


> Re. the 6DT6... is anyone using a brand other than RCA?  The RCAs are looking a bit scarce at the moment (we've probably bought them all up!).


 
  Sylvania... so far they sound very similar!


----------



## Edgard Varese

Quote: 





kvtaco17 said:


> Sylvania... so far they sound very similar!


 
  Excellent, thanks! I've got a query out now about a pair of RCAs but if I can't get those I will go for the Sylvanias.


----------



## MIKELAP

Quote: 





edgard varese said:


> Re. the 6DT6... is anyone using a brand other than RCA?  The RCAs are looking a bit scarce at the moment (we've probably bought them all up!).


 
  Theres G.E. 6DT6A he's got 8 he's asking $1.75 and you can make an offer i paid $1.25 each for mine heres the link  if your interested                                         http://www.ebay.com/itm/6DT6-NOS-NIB-Vacuum-Tube-GE-Canada-Pentode-/200956736530?pt=Vintage_Electronics_R2&hash=item2ec9f47412                       and theres 4 G.E. JAPAN available also he's asking $1.49 each i paid $1.25 each maybe give him less who knows.


----------



## Edgard Varese

Quote: 





mikelap said:


> Theres G.E. 6DT6A he's got 8 he's asking $1.75 and you can make an offer i paid $1.25 each for mine heres the link  if your interested                                         http://www.ebay.com/itm/6DT6-NOS-NIB-Vacuum-Tube-GE-Canada-Pentode-/200956736530?pt=Vintage_Electronics_R2&hash=item2ec9f47412                       and theres 4 G.E. JAPAN available also he's asking $1.49 each i paid $1.25 each maybe give him less who knows.


 
  Thanks for that Mike, do you like the GEs?


----------



## kvtaco17

I have the GE's coming in next week!


----------



## Edgard Varese

Quote: 





kvtaco17 said:


> I have the GE's coming in next week!


 
  The shipping to New Zealand on the listing Mike provided is quite reasonable... fingers poised for purchase...


----------



## gibosi

GE 6HZ6 (and probably the GE 6DT6 as well)
   
  In order to get a handle on the sound of this tube, I pulled out the venerable GE 8425A (a premium version of the 6AU6/EF94) to compare. For those just joining us, this is the first non-traditional tube that completely blew everything else out of the water, some 120 pages ago. At that time, it was the very best tube any of us had ever heard in our Little Dots. Since then, it has been outclassed by the Tung Sol 6485 and a number of the heptodes, but even so, the 8425A is still an excellent tube. Unfortunately, we have not again encountered another top-tier tube from GE. Given this history, it seems appropriate to see if the GE 6HZ6 delivers.
   

   
  (I think my picture-taking has improved? 
   

   

  The GE 8425A was configured in the EF95 2-7 strapping (we have no other choice as this is the only way we can use this tube in our Little Dots) and the GE 6HZ6 in the EF95 1-7 strapping. Rolling in the 8425A, I realized that it has been long time since I listened to this tube, and I had forgotten just how much I liked it. It still sounds really good to my ears. So is the 6HZ6 better?
   
  No, I don't think so... The GE sonics that I really like are certainly there, the lows, mids and highs are unmistakably GE, and very good. But there are a couple things that don't feel quite right. The sound stage on the 6HZ6 is bit wider, but not by much. However, it feels flatter and more two dimensional. Voices seem to be right in my face and the sensation of a 3D space just isn't as good as with the 8425A. And I am not sure if this is related, but music doesn't sound quite as clear, almost as if there is a slight veil between the music and my ears.
   
  So while the GE 6HZ6 is still a pretty good tube, I have to give the nod to the GE 8425A for its greater clarity and sense of space. And if you do not have this tube in your collection, I encourage you to get a pair. You just might be surprised.


----------



## Edgard Varese

Thanks to MIKELAP I now have a pair of GE 6DT6A on the way to me $2.50 not including shipping.


----------



## siles1991

Just bought a pair of RCA 6DT6A's 6.90$ inclusive of shipping ^_^


----------



## mab1376

I've seen 2 variants of the RCA 6DT6A with black and grey plates, any info on which is better?


----------



## gibosi

Quote: 





mab1376 said:


> I've seen 2 variants of the RCA 6DT6A with black and grey plates, any info on which is better?


 
   
  I few pages ago, I compared a pair of RCA 6HZ6 with light grey plates and a pair of RCA 6DT6 with black plates, and they sound identical to me. I also have two pairs of RCA 6AV6, one pair with light grey plates and the other with black plates, and again, they sound identical. So I doubt that one is any better than the other.


----------



## Oskari

Quote: 





mordy said:


> Did not find much in trying to research Japanese tube manufacturers


 
   
  This site is packed with information and photos.
   

 http://www.geocities.jp/radiomann/AJR.html
   
  It's mostly in Japanese, though. So, Google Translate is very useful for a gaijin like me.
   
  Here's the page with 6BE6 as an example.
   

 http://www.geocities.jp/radiomann/HomePageVT/Radio_tube_6JA.html
   
  I learned that Toshiba used the Mazda (Matsuda) brand on their tubes till 1959. That's yet another Mazda in addition to the French, Belgian and UK ones!


----------



## Audiofanboy

Quote: 





oskari said:


> This site is packed with information and photos.
> 
> 
> http://www.geocities.jp/radiomann/AJR.html
> ...


 
   
  Thanks for the links! I actually understand and speak a fair deal of Japanese, but reading a whole website is a bit of a challenge lol, so google translate is pretty handy...
   
  Everytime I see a Mazda tube now, it almost gets me worried, as it always seems to be _some new mysterious tube brand_, never the same Mazda factory as the last tube. Fortunately, the last Mazda tube I tested turned out to be much better than the previous ones.
   
  Speaking of EH90 tubes, I plugged and listened to my "Pope" Mullard tubes 1-7 strapped today, and I have to admit that this might be the preferred setting for these tubes. Despite having come up with the idea of tying the two signal grids together on heptodes, I have to admit that I hadn't enjoyed a single one of these tubes strapped since the Tele/vanias 5915... And even those ended up sounding a little thin strapped imo...
   
  Earlier, I was discussing with gibosi how it didn't make much sense to me to 1-7 strap 6DT6/6HZ6 "dual control pentodes", that is strapping the signal grid and the suppressor grid. I had mostly looked at the GE datasheets for the 6DT6 tube originally, and pin 7 did seem to be our usual pentode-like suppressor grid, which didn't seem like a signal grid in my mind.
   
  An hour or so of google-browsing later, I'm actually not so convinced of that. Apparently, g3 in dual control pentodes isn't wired in the same "loose" way as a normal suppressor grid, so it *could* be used as a control grid of sorts -hence the name. I still wouldn't use it as the sole signal grid, but still, I have to wonder whether or not it was really meant to be used as an actual signal grid... Having a secondary signal grid behind the pentode g2 screen grid or sandwhiched between heptode g2 & g4 grids just never sat well with me; and we can hear, on heptodes, that it often yields odd results (thin, fast, unnatural).
   
  But still, it _can_ make sense, in a way; which is why we even tried it, basically.
   
  So, my question to all of you that have tried the 6DT6 tubes is: have you tried them EF92'd/6-7 strapped or 2-7 strapped (which shouldn't change the sound much, _theoretically_, at least if these were a regular pentodes), and does it sound different from the odd 1-7 strap setting?
   
  Speaking of dual control heptodes -and going back to the glorious days when we first tried non-standard tubes- has anyone tried those different "strap settings" on the venerable 6GX6/6GY6 (which should behave the _exact_ same way as a 6DT6 or 6HZ6)? I can't test it since my only pair of those is now living in Montréal... Has their new owner tested it by any chance lol  ?


----------



## MIKELAP

Quote: 





audiofanboy said:


> Thanks for the links! I actually understand and speak a fair deal of Japanese, but reading a whole website is a bit of a challenge lol, so google translate is pretty handy...
> 
> Everytime I see a Mazda tube now, it almost gets me worried, as it always seems to be _some new mysterious tube brand_, never the same Mazda factory as the last tube. Fortunately, the last Mazda tube I tested turned out to be much better than the previous ones.
> 
> ...


 
  There  in the mail Super maybe ill get them at the end of the coming week .From Florida usually it takes 7 days from France i dont really know 1 week 1/2 maybe.good thing because tubes are stacking up and im expecting 6ha5 ,6an5 6hz6,and RCA 6DT6A so i gotta stop buying tubes thats what it means.


----------



## gibosi

Quote: 





oskari said:


> This site is packed with information and photos.
> 
> 
> http://www.geocities.jp/radiomann/AJR.html
> ...


 
   
  This site is a great find. And it has pictures!
   
  I have a pair of Japanese-made 6AV6 and I am very hopeful these pictures will help me figure out who made them. Thanks!


----------



## GCooper

Here is the official GE spec sheet for the 6BE6 as a pentagrid converter--
   
  www.wdv.com/Electronics/*Radio*s/Hammarlund/pdf/*6BE6*.pdf
   
  Here is one article on how amateur radio operators and tube enthusiasts can use it--
   
  k3uh.com/test/SW_Receiver.htm
   
  Keep the electrons flowing!
   
  Gordon Cooper
  KE7RYM


----------



## Iron58p

Some one can tell me somethin about  Philips Miniwatt TS62/408A ?
  Price of 20$ each is too expensive compared with quality sound ?
   
  And again, other brands of 408A, did anyone listen ?


----------



## gibosi

Quote: 





iron58p said:


> Some one can tell me somethin about  Philips Miniwatt TS62/408A ?
> Price of 20$ each is too expensive compared with quality sound ?
> 
> And again, other brands of 408A, did anyone listen ?


 
   
  I have a pair of these... I found them to be about the same as the Sylvania 408A with gold pins, so they are among the very best 408As. But in my opinion, even the best 408A is not as good as the tubes we are currently discussing.


----------



## Iron58p

Thank's Gibosi 
	

	
	
		
		

		
			




   
  Your words say all what i need.
   
  I asked for availability :
   
  Siemens AK90
  Tung.sol 6AH6WA/6485
  RCA and Sylvania 6DT6WA
  GE 8425A
   
  Also for Siemens EK90, but i'm waiting to receive Miniwatt Z&I EH90
   
  I don't know if betweem EH90 and AK90 there are notable differences, i don't want buy two same items


----------



## gibosi

Quote: 





iron58p said:


> I asked for availability :
> 
> Siemens AK90
> Tung.sol 6AH6WA/6485
> ...


 
   
  AK90 = EK90?
   
  And it depends on which version of the Siemens EK90 you are considering. If it is the version that I have, then you don't need it. The Miniwatt EH90 unstrapped sounds the same as my Siemens EK90. If it is different than mine, it will likely sound different....


----------



## gibosi

Working through my back log of new tubes, now have a pair of 1958 FIVRE 6AT6/EBC90 triodes burning in. First impressions, I like them. And I notice that their construction bears some resemblance to my 1958 GE 6AV6/EBC91.
   
  FIVRE
   

   
  GE


----------



## mordy

There was a mention that it was hard to find the 6DT6 tubes. Here is a link to a seller I have dealt with several times. The prices are very reasonable, and this seller is very cooperative and honest.
   
  http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=330994068719


----------



## Oskari

Quote: 





gibosi said:


> I have a pair of Japanese-made 6AV6 and I am very hopeful these pictures will help me figure out who made them. Thanks!


 
   
  See http://www.geocities.jp/antique_radio_exhibition/ as well.
   

 http://www.geocities.jp/antique_radio_exhibition/tubes_mt1.html
 http://www.geocities.jp/antique_radio_exhibition/tubes_mt2.html


----------



## Acapella11

Quote:  





> So while the GE 6HZ6 is still a pretty good tube, I have to give the nod to the GE 8425A for its greater clarity and sense of space. And if you do not have this tube in your collection, I encourage you to get a pair. You just might be surprised.


 
   
  Haven't heard thew 6AU6 in ages. Put it in now having also different gear, just for curiosity. Yes, surprisingly good. I could do with a larger stage, but else nice and sweet mids, good instrument separation and very enjoyable transparency / clarity. The well articulated bass goes also nicely low. Fun to come back to an almost forgotten tube. Cheers.
   
  6BD6 are added to the table on p. 77.


----------



## mordy

Hi Oskari,
   
  Many thanks for finding such great information on Japanese tubes. There is one tube designation shown that I believe is not on our list on page 77. Can these be used in the Little Dot MKIII?
   
  http://www.geocities.jp/antique_radio_exhibition/tubes_mt1.html
   
  6BD6
   
  Am I correct in that there were four major manufacturers: Toshiba, Matsu****a/National (Panasonic today), NEC and Hitachi?
   
  Did Phillips supply tooling for all four?


----------



## gibosi

Quote: 





oskari said:


> See http://www.geocities.jp/antique_radio_exhibition/ as well.
> 
> 
> http://www.geocities.jp/antique_radio_exhibition/tubes_mt1.html
> http://www.geocities.jp/antique_radio_exhibition/tubes_mt2.html


 
   
  Thanks! 
   
  Some of the pictures are not the greatest, but I have found one that seems pretty close:
   
  BESTO 6AV6
   
  http://www.geocities.jp/radiomann/HomePageVT/Radio_tube_6JA.html#Besto
   
  Multvox 6AV6


----------



## mordy

Shucks, I got censured! Man, I mean, how can they advertise the Sh amp on this forum??? Maybe the extra "I"? Let's try it:
   
  MATSUSHIITA
   
  Yep, it worked!
   
  Am I correct in that there were four major manufacturers: Toshiba, Matsushiita/National (Panasonic today), NEC and Hitachi?
   
  U gotta appreciate them Head-Fii headaches!


----------



## gibosi

Quote: 





mordy said:


> 6BD6


 
   
  We would need to strap these in the same way as 6AU6 and 6AH6, but otherwise, I can see no reason why they wouldn't work in our LDs.
   
http://www.radiomuseum.org/tubes/tube_6bd6.html
   
  http://www.classiccmp.org/rtellason/tubedata/6BD6.pdf
   
  Edit: Oh, this is not sharp cut-off, but remote cut-off, so nonlinear by design... probably not a good driver tube.....


----------



## Oskari

Quote: 





audiofanboy said:


> Everytime I see a Mazda tube now, it almost gets me worried, as it always seems to be _some new mysterious tube brand_, never the same Mazda factory as the last tube. Fortunately, the last Mazda tube I tested turned out to be much better than the previous ones.


 
   
マツダ is quite difficult to mix up with the other Mazdas.


----------



## Audiofanboy

Yeah, Mazda wouldn't even be written like in katakana... Still, when I hear Mazda now, I get anxious lol.

6BD6 = remote cut-off = bad idea

EF92s were semi-remote, but linear over the range we use(d) them, so OK. Remote cut-off tubes just won't be ideal on the standard LD amps. On the I+, it could be OK though, and I think gibosi had successfully tested a remote cut-off 6BA6 on his amp (you had, right? I forget...).


----------



## Oskari

Quote: 





mordy said:


> Am I correct in that there were four major manufacturers: Toshiba, Matsushiita/National (Panasonic today), NEC and Hitachi?


 
   
  Apparently those plus TEN (Kobe Kogyo, later part of Fujitsu) were the big names in receiving tubes postwar.
   
  Quote: 





mordy said:


> Did Phillips supply tooling for all four?


 
   
  As far as I understand, Matsush¡ta was not an established tube manufacturer and bought Philips technology to get in the game. The others may have been established manufacturers or had other partners. Hitachi, for example, co-operated with Raytheon (Hit-Ray brand!), and Toshiba was totally in bed with GE and NEC with Western Electric prewar.


----------



## mordy

Found a few bits and pieces trolling the Internet:
   
  "Old Japanese tubes like Matsushiita, Awai, and examples made on the old Mullard tooling are some of the best values in tube HiFi IMO. "
   
  "The link between Matsushiita and Philips was that they entered into a joint "technical cooperation" agreement starting 1952-53. In essence, Philips offered premier technical guidance in exchange for access of acknowledged managerial/corporate acumen of Mr. Konosuke Matsushiita, and I think there were financial compensations too. Unlike Mullard, Matsushiita was never owned or controlled by Philips, but starting 1953 much of their engineering, design, technical production including tubes was heavily influenced/donated by Philips and by mid-late '50s it certainly showed in their tubes, both literally and figuratively, across a spectrum of details. Matsushiitas tended to evolve along similar lines as W. Euro Philips versions "
   
  Note: An added i has been added to the Matsu****a name to avoid censorship lol
   
  PS: Awai brand?


----------



## Oskari

Quote: 





mordy said:


> PS: Awai brand?


 
   
  Nothing. Error? Off-brand?


----------



## Edgard Varese

Quote: 





mordy said:


> There was a mention that it was hard to find the 6DT6 tubes. Here is a link to a seller I have dealt with several times. The prices are very reasonable, and this seller is very cooperative and honest.
> 
> http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=330994068719


 

 Thanks Mordy, I have sent a message to the seller to ask whether he has a pair of RCA tubes...


----------



## gibosi

Quote: 





oskari said:


> See http://www.geocities.jp/antique_radio_exhibition/ as well.
> 
> 
> http://www.geocities.jp/antique_radio_exhibition/tubes_mt1.html
> http://www.geocities.jp/antique_radio_exhibition/tubes_mt2.html


 
   
  After looking more closely at all these pictures, I now don't think my 6AV6 were manufactured by BESTO. As the pictures are not the best, it's really very hard to say with any certainty, but the tube it seems to match most closely is the second tube from the right:
   
  http://www.geocities.jp/antique_radio_exhibition/tubes/6av6.jpg
   
  The shape of the glass envelope, the mica, the tall getter support rod, the metal structure situated on the top mica look right. Unfortunately, we cannot see the getter or the top of the diode plates, but from what we can see, it matches up well....
   
  The text indicates that this tube is manufactured by 日本ビクター株式会社 which translates to the Victor Company of Japan. We now know this company as JVC. Pre-WWII, RCA-Victor was the majority stock holder. After WWII, Matsushta (Panasonic) became the majority stockholder. (Since the "i" is not vocalized, writing "shta" facilitates the correct pronunciation and doesn't trip the forum censor. win-win) Anyway, these don't look anything like any RCA I have ever seen, and they don't look like the few pictures of Matsushta 6AV6 I have seen. So until I learn different, these are JVC 6AV6. This is my story and I'm sticking with it! lol


----------



## gibosi

Quote: 





audiofanboy said:


> EF92s were semi-remote, but linear over the range we use(d) them, so OK. Remote cut-off tubes just won't be ideal on the standard LD amps. On the I+, it could be OK though, and I think gibosi had successfully tested a remote cut-off 6BA6 on his amp (you had, right? I forget...).


 
   
  Yes indeed, I tested several pairs of 6BA6 in my LD1+, including a pair manufactured in 1947, and they sounds fine... maybe not great, but at least average. 
   
  The LD1+ uses tubes as buffers, not as drivers to provide voltage gain before a power tube. In fact, tubes in the 1+ provide something less than unity gain. Believe or not, you could cut all the tube circuitry out of this amp, replace it with a straight wire, and it would work fine. (Yes, it has been done! lol )


----------



## Iron58p

Using the cutter posted some days ago by Gibosi, is safe to put the cutting wheel against the glass ?
   
  Or is better stay a little bit far ( for example 1 millimeter ) from it ? It's first time that i will do...


----------



## gibosi

Quote: 





iron58p said:


> Using the cutter posted some days ago by Gibosi, is safe to put the cutting wheel against the glass ?
> 
> Or is better stay a little bit far ( for example 1 millimeter ) from it ? It's first time that i will do...


 
   
  It is best to cut the pins as close to the glass as you can. It is safe. And you will discover that the pins are fairly soft and cut easily.


----------



## Jesterphile

Not incredibly impressed with my Little Dots build, I understand its a cheap amp made in China, but the transformer wasn't even screwed down and was banging around in its housing...
   
   
  The amp sounds good though


----------



## MIKELAP

Quote: 





jesterphile said:


> Not incredibly impressed with my Little Dots build, I understand its a cheap amp made in China, but the transformer wasn't even screwed down and was banging around in its housing...
> 
> 
> The amp sounds good though


 
  A guy received is Burson Conductor and out of the box it wasnt working  good i understand or not at all turns a connection for the stepped attenuator wasnt even plugged in so these days you never know its like multiple recalls for cars its almost normal these days.


----------



## MIKELAP

Quote: 





gibosi said:


> It is best to cut the pins as close to the glass as you can. It is safe. And you will discover that the pins are fairly soft and cut easily.


 
   
  Quote: 





iron58p said:


> Using the cutter posted some days ago by Gibosi, is safe to put the cutting wheel against the glass ?
> 
> Or is better stay a little bit far ( for example 1 millimeter ) from it ? It's first time that i will do...


 
   
   
  Quote: 





gibosi said:


> It is best to cut the pins as close to the glass as you can. It is safe. And you will discover that the pins are fairly soft and cut easily.


 
  Personnally  i was tempted to use a cutting wheel also but like gibosi said there easy to cut with cutters and what remains about 2 millimeters  i file down with a small file being careful not to touch the other pins close by and after put electrical tape over the 2 pins you just filed down .


----------



## Audiofanboy

Quote: 





mikelap said:


> Personnally  i was tempted to use a cutting wheel also but like gibosi said there easy to cut with cutters and what remains about 2 millimeters  i file down with a small file being careful not to touch the other pins close by and after put electrical tape over the 2 pins you just filed down .


 
   
  I've done it the same way since the second pair of tubes I chopped up (on the first tube, pins snapped off clean and neatly, but on the second I tried it on, the tube imploded, so now I use cutters...).
   
  I would tend to encourage using some kind of protection on the chopped off pins -like electrical or thick duct tape- just on the off chance that _something_ gets connected _somewhere it wasn't supposed to_. It just seems silly to mangle your amp for a silly one-shot mistake...


----------



## jaywillin

does anyone know of or can you recommend a good reference book on tubes , starter guide, history etc ???


----------



## duncan1

For accuracy and presenting the true engineering also  specs. of tubes try to obtain  RCA tube manuals-Mullard  tube manuals-Osram-  Phillips-Mazda Also The Radio Tube-Vade-Mecum-1950s onward  especially- Radio Valve[tube] Data-- [ Wireless World-AKA-Electronics World.] Characteristics of 7000 tubes/6/7/8editions. While specs of tubes can be downloaded from the Web. It is much better to buy an old engineering manual as it  contains things like -inter-electrode capacitance-output at a set plate current/grid bias. etc and equivalents which is a lot easier to look through than keeping it on your PC.


----------



## gibosi

Quote: 





jaywillin said:


> does anyone know of or can you recommend a good reference book on tubes , starter guide, history etc ???


 
   
  Haven't really looked for any books, so if you find something, please let us know.
   
  In the meantime, these might be helpful:
   
  How Vacuum Tubes Work
  by Eric Barbour
   
  http://www.vacuumtubes.net/How_Vacuum_Tubes_Work.htm
   
  Pentodes connected as Triodes
   by Tom Schlangen
   
  http://www.kaponk.com/~yanyong/ETF06TS.pdf


----------



## jaywillin

Quote: 





gibosi said:


> Haven't really looked for any books, so if you find something, please let us know.
> 
> In the meantime, these might be helpful:
> 
> ...


 
   
  Quote: 





duncan1 said:


> For accuracy and presenting the true engineering also  specs. of tubes try to obtain  RCA tube manuals-Mullard  tube manuals-Osram-  Phillips-Mazda Also The Radio Tube-Vade-Mecum-1950s onward  especially- Radio Valve[tube] Data-- [ Wireless World-AKA-Electronics World.] Characteristics of 7000 tubes/6/7/8editions. While specs of tubes can be downloaded from the Web. It is much better to buy an old engineering manual as it  contains things like -inter-electrode capacitance-output at a set plate current/grid bias. etc and equivalents which is a lot easier to look through than keeping it on your PC.


 

 thanks guys, plenty of stuff to get me started, plus the stuff here on head fi
  , i'll keep looking and reading !


----------



## gibosi

Quote: 





iron58p said:


> Using the cutter posted some days ago by Gibosi, is safe to put the cutting wheel against the glass ?
> 
> Or is better stay a little bit far ( for example 1 millimeter ) from it ? It's first time that i will do...


 
   
  Quote: 





mikelap said:


> Personnally  i was tempted to use a cutting wheel also but like gibosi said there easy to cut with cutters and what remains about 2 millimeters  i file down with a small file being careful not to touch the other pins close by and after put electrical tape over the 2 pins you just filed down .


 
   
  I posted a picture of some flush cutters, so I am assuming that this is what Iron58p is using, and not a Dremel-type tool. And as English is not his first language, my guess is that "cutting wheel" means the cutting blades of the flush cutters.....
   
  And as Audiofanboy suggests, covering the pin stubs with some electrical tape is a very cheap and easy way to protect against inadvertantly shorting something out.


----------



## Iron58p

Quote: 





gibosi said:


> I posted a picture of some flush cutters, so I am assuming that this is what Iron58p is using, and not a Dremel-type tool. And as English is not his first language, my guess is that "cutting wheel" means the cutting blades of the flush cutters.....
> 
> And as Audiofanboy suggests, covering the pin stubs with some electrical tape is a very cheap and easy way to protect against inadvertantly shorting something out.


 
   
  I confirm that i have ordered Pro'Skit[size=x-small] 8PK-30D, but until not is not dispached, so i can't tell anything, i think will be perfect for the use !![/size]
   
  [size=x-small]And today i have made another order, i'm reading review on this post and i want to test some tubes ( if and when will arrive
	

	
	
		
		

		
			





 ).[/size]
   
  [size=x-small][size=x-small]2 Sylvania 6dt6
 2 RCA 6dt6a
 2 Sylvania 6hz6 [/size][/size]
   
  [size=x-small][size=x-small]Gibosi, my italian/english is perfect !! 
	

	
	
		
		

		
		
	


	




[/size][/size]


----------



## Oskari

Quote: 





gibosi said:


> The text indicates that this tube is manufactured by 日本ビクター株式会社 which translates to the Victor Company of Japan. ... Anyway, these don't look anything like any RCA I have ever seen, and they don't look like the few pictures of Matsushta 6AV6 I have seen. So until I learn different, these are JVC 6AV6.


 
   
  That's a Matsush¡ta tube. "Mark of the dog only with Matsush¡ta made ​​JVC." (Dog = Nipper.)
   
  Finding good enough photos that show the tube from all relevant angles is difficult but I must put my money on Toshiba.
   

 http://vintageaudiotube.blogspot.fi/2011/10/toshiba-6av6.html
   
  Note the octagon as well as the construction.


----------



## gibosi

Quote: 





oskari said:


> That's a Matsush¡ta tube. "Mark of the dog only with Matsush¡ta made ​​JVC." (Dog = Nipper.)
> 
> Finding good enough photos that show the tube from all relevant angles is difficult but I must put my money on Toshiba.
> 
> ...


 
   
  First I want to say that your internet sleuthing ability is second to none! 
   
  And I have to agree with you.... Even though the JVC tube looks to be the same, the Toshiba is a dead ringer. Further, we have quite a bit of evidence to suggest that Toshiba was a major player in the production of tubes for the international export market.
   
  The text states that Matushta manufactured the JVC tube, but the picture of the Matushta was so poor that I could not determine if the two tubes were the same. And I have to admit that I was a bit stumped by "mark of the dog" (犬のマーク) as it also means "not very good". I didn't catch the Nipper connection.... lol


----------



## Oskari

Quote: 





gibosi said:


> First I want to say that your internet sleuthing ability is second to none!


 
   
  Thanks (but I must admit that's the first hit I get with toshiba 6av6)!


----------



## Advil

anyone using an MKIII with q701s?
   
  i have a little dot II++ and kind of want to upgrade but idk if it's worth the money. if i upgrade i can use my old tubes (mullard 161's) with it but i'm kind of doubting that it's worth 350 bucks


----------



## gibosi

Quote: 





advil said:


> anyone using an MKIII with q701s?
> 
> i have a little dot II++ and kind of want to upgrade but idk if it's worth the money. if i upgrade i can use my old tubes (mullard 161's) with it but i'm kind of doubting that it's worth 350 bucks


 
   
  I have no experience with the q701 or the Little Dot II++, so I don't have any opinion.... But I am curious. What would you hope to gain by getting the LD III?


----------



## Advil

Quote: 





gibosi said:


> I have no experience with the q701 or the Little Dot II++, so I don't have any opinion.... But I am curious. What would you hope to gain by getting the LD III?


 
  I was hoping to warm up the cans a little bit and maybe bring out more of the low end. They're very, very analytical and I like that but sometimes it's a bit overwhelming.


----------



## gibosi

Quote: 





advil said:


> I was hoping to warm up the cans a little bit and maybe bring out more of the low end. They're very, very analytical and I like that but sometimes it's a bit overwhelming.


 
   
  Is it possible to run the same driver tubes in the LD II++ as in the LDIII? That is, can you currently run EF91, EF92 and EF95? If so, it seems to me that you should be able to add more warmth and bass emphasis simply by rolling some different driver tubes....


----------



## kvtaco17

The q701 is a 62 Ohm can... the MKIII puts out 300 mW @ 120 ohm  and 100 mW @ 32 ohm... the 1+ puts 300mW @ 120 ohm and  800mW @ 32 ohms... the 1+ will probably put more current into the q701 then the MKIII will... not sure though I sold my q701 long before I got the little dot 1+


----------



## Advil

Quote: 





gibosi said:


> Is it possible to run the same driver tubes in the LD II++ as in the LDIII? That is, can you currently run EF91, EF92 and EF95? If so, it seems to me that you should be able to add more warmth and bass emphasis simply by rolling some different driver tubes....


 
   
  yeah the II++ uses EF92 and the III can accept those if i understand correctly.
  Quote: 





kvtaco17 said:


> The q701 is a 62 Ohm can... the MKIII puts out 300 mW @ 120 ohm  and 100 mW @ 32 ohm... the 1+ puts 300mW @ 120 ohm and  800mW @ 32 ohms... the 1+ will probably put more current into the q701 then the MKIII will... not sure thoughh I sold my q701 long before I got the little dot 1+


 
   
  That would be interesting and convenient since it's so cheap. I can google around and see peoples impressions of this.


----------



## gibosi

Quote: 





advil said:


> yeah the II++ uses EF92 and the III can accept those if i understand correctly.


 
   
  So the II++ cannot use EF95? If so, I think it may well be worth while to get a newer LD, one that can use both EF95 and EF92 tubes.
   
  And I have LD1+, and I am very pleased with it, especially for the price. The 1+ also allows you to roll op amps as well as tubes, so a lot of flexibility for the money. And I believe that kvtaco17 also has the 1+.


----------



## kvtaco17

Quote: 





gibosi said:


> So the II++ cannot use EF95? If so, I think it may well be worth while to get a newer LD, one that can use both EF95 and EF92 tubes.
> 
> And I have LD1+, and I am very pleased with it, especially for the price. The 1+ also allows you to roll op amps as well as tubes, so a lot of flexibility for the money. And I believe that kvtaco17 also has the 1+.


 

 I do have a 1+ in my collection, I use it a ton!


----------



## mordy

Hi Acapella 11,
   
  Some time back you asked me if I had evaluated different power tubes that I had planned to do. I finally gathered up the mental energy to check out four different types that I have, all from the Novosibirsk factory. Driver tubes were the RCA DTox tubes in 1/7 strapping.
   
  This task is akin to evaluating Coca Cola cans for taste from different bottling companies. Basically it is all very similar, but each bottling plant has a different water supply and ingredients from different places, and the soda tastes slightly different. In listening to these double triode tubes, I felt that it helped to have honed my ears on listening to heptodes, becoming aware of subtle differences.
   
   
  The first power tube is a 6N6P from October 1975. The overall sound is pleasant, but the bass is soft and lacking in punch, slam and attack. The mid range tends towards the cool side. The highs are OK but too sharp. Details are good, but this tube is lacking in excitement and listening satisfaction, mainly because the macro dynamics are somewhat anemic.

   
   
  The next power tube is the 6N6P with gold grid from October 1978. In comparison to the 6N6P above, it has much stronger and better defined bass with very good slam and attack. The mid range is sweet, and the upper range is very good.  There is a coherent musical presentation and very good instrument separation. (BTW, GE invented the gold grid. It is found in their long life 5 star tubes. The amount of gold is minuscule, and I don't think that the price of the tube is effected by the changing  price of gold - lol).

   
   
  The next tube is the OEM 6N6Pi from June 1984 that came with the amp. Overall sweet and fairly detailed. Bass is good but lacking real heft and punch. The tube is lacking in treble detail and the treble is on the shrill side. Better than the 6N6P, but not the ultimate.
  It has been said that the 6N6Pi is rated for 500 hours of service, and the other variants for 3000 hours. So far, none of these tubes have given up, and my guess is that those service hours are rated for a harsh environment in a MIG jet or military vehicle. Looking at the saucer getter, it is obvious that the tube was put together by a left handed person in their forties, and that you need to tilt your head towards the right to get the full listening experience.

   
   
  Lastly, the mighty 6N6P-IR tube from May 1983 with smoked glass. These tubes are the best in this group, with real effortless punch, slam and attack in the bass, and top notch mid and upper ranges. These tubes bring additional clarity to the sound presentation with instruments standing out better in the sound stage.

   
  In summary, the least desirable of the four types is the 6N6P and 6N6Pi. Then follows the 6N6P gold grid and the winner 6N6P-IR. The main easily noticeable difference between the tubes is how the bass is presented; the other differences described are there but more subtle.
   
  The combination RCA 6DT6 (DTox) and 6N6P-IR is just plain intoxicating.....


----------



## GCooper

archive.org is an excellent starting point for public domain books on electronics, tubes and tube circuitry. Any number of "bundlers" have put together outstanding DVD collections of public domain and long out of print electronics books, and they are on eBay and elsewhere. If you want a detailed list, email me privately.
   
  Personally, I am using the NEETS (Navy Electricity and Electronics Training Series) from 1998 as primary reference and supplementing it out of memory (I covered these materials in 1977-1978 when I was in the Navy and tube gear was still king) or with RCA and other tube engineering handbooks. NEETS is available free from a Fleet Reserve website. The modules assume you know nothing at all and proceed from that into practical engineering and equipment operation.


----------



## siles1991

I just got my mkIV SE and i realized my right 6n6p-IR glows slightly brighter than my left one? any answers? i switched the tubes as well and it seems its the tube itself that glows brighter weird...


----------



## Iron58p

I received today a pair of matched Tesla 6F32-6AK5
   
  Now i'm burnin in 
   
   

   
  Received  Telefunken EH900S EH91 and Lorenz ITT 6AV6 EBC91 but my Pro'skit cutter is not until now dispached, so i must wait.
   
  First impression about Tesla,that seems don't need burn in, unstrapped and EF95 configuration : with my Alessandro MSPRO sounds great from the beginnig, bass dry and fast under control and sound clear and trasparent, a little bit bright for someone but not for my musical taste.
  Seems a monitor sound, soundstage is weak but....medium and highs refined and detailed.
  Seems that vocalist is singing in front of you.
   
  This is sound that i love : bass under control, highs clean and sound open !!
   
  I remember to all that is my first pair of tubes ( no considering the stock tubes with LD I+), and that my opinion can change after burn in and don't forget that i'm a novice.


----------



## Iron58p

Telefunken EH900S/5915 ( EF95 config ) sounds different from Tesla, more soundstage and more details, mids and highs are very clean and extended ,my surprise in that bass aren't too strong for my hears.
  More hight grade of trasparence .
  For my opinion sounds great without cutting pins, but i haven't tryed with pins 1-7 cutted, i don't think that i will try.
   
  Lorenz 6AV6 don't sound without cut pins, so i must wait


----------



## Oskari

Quote: 





siles1991 said:


> I just got my mkIV SE and i realized my right 6n6p-IR glows slightly brighter than my left one? any answers? i switched the tubes as well and it seems its the tube itself that glows brighter weird...


 
   
  Has the brighter one more of the heaters visible outside of the cathode sleeves? That could explain the difference and would be just cosmetic.


----------



## MIKELAP

Quote: 





iron58p said:


> I received today a pair of matched Tesla 6F32-6AK5
> 
> Now i'm burnin in
> 
> ...


 
  Heres a link for date codes for tesla 6F32          http://tubes-store.com/article_info.php?articles_id=5 Looks like year 1955


----------



## Iron58p

Thank's Michelap
   
  i have made a change, and i have a big problem.
   
  Tried Lorenz tubes with 408A configuration ( removed jumpers from j1 e j2, and k1/k2 switchies to the central pin and pin to the side marked 408A, ed immediately i see smoke coming out from electronic card side ).
   
   
  I'm lucky to have seen it within some seconds and turn ampli off !!
   
  Question : is this EF95 set ?
   
  I don't understand why happened, and now i have fear to make test


----------



## gibosi

Quote: 





iron58p said:


> Thank's Michelap
> 
> i have made a change, and i have a big problem.
> 
> ...


 
   
  408A tubes have 20 volt heaters. Your Lorenz has 6.3 volt heaters. So you just put 20 volts into a tube designed for 6.3 volts! Please consult page 77 to see how to use tubes in your amp. You must follow these guidelines, or you might kill your tubes, or worse, kill your amp.
   
  Again, the Lorenz must be used in the EF92 setting with pins 5 and 6 cut off. It will not work any other way!


----------



## MIKELAP

Quote: 





gibosi said:


> 408A tubes have 20 volt heaters. Your Lorenz has 6.3 volt heaters. So you just put 20 volts into a tube designed for 6.3 volts! Please consult page 77 to see how to use tubes in your amp. You must follow these guidelines, or you might kill your tubes, or worse, kill your amp.
> 
> Again, the Lorenz must be used in the EF92 setting with pins 5 and 6 cut off. It will not work any other way!


 
  this is for what amp gibosi and where do you see this on page 77and those run with pins 5 and 6 cutoff never saw that hmmm.!


----------



## gibosi

Quote: 





mikelap said:


> this is for what amp gibosi and where do you see this on page 77and those run with pins 5 and 6 cutoff never saw that hmmm.!


 
   
  The LD 1+ has the ability to run 408A tubes. as well as EF92 and EF95. 408A tubes are essentially EF95 tubes with 20 volt heaters.
   
  http://www.radiomuseum.org/tubes/tube_408a.html
   
  The Lorenz are 6AV6/EBC91 tubes. Therefore, we need to set the amp up in the EF92 configuration and cut off pins 5 and 6, as indicated on page 77.


----------



## MIKELAP

Quote: 





gibosi said:


> The LD 1+ has the ability to run 408A tubes. as well as EF92 and EF95. 408A tubes are essentially EF95 tubes with 20 volt heaters.
> 
> http://www.radiomuseum.org/tubes/tube_408a.html
> 
> The Lorenz are 6AV6/EBC91 tubes. Therefore, we need to set the amp up in the EF92 configuration and cut off pins 5 and 6, as indicated on page 77.


 
  gibosi you said to cutoff pins 5 and 6 which is right i just saw on page 77 it is written on top EF91-92+CUTOFF AND TAPE PINS 5&7 thats not right !


----------



## gibosi

Quote: 





mikelap said:


> gibosi you said to cutoff pins 5 and 6 which is right i just saw on page 77 it is written on top EF91-92+CUTOFF AND TAPE PINS 5&7 thats not right !


 
   
  Yes, this is a mistake. Acapella11 maintains this chart, so I will send him a PM.


----------



## MIKELAP

Quote: 





gibosi said:


> Yes, this is a mistake. Acapella11 maintains this chart, so I will send him a PM.


 
  Good thing i always go with my picture when cutting .


----------



## Iron58p

First of the three settings on the manual ( to use WE408A ), for what kind and family of tubes can be used ?
   
  Using with Telefunken EH900S don't work, it's normal ?


----------



## TrollDragon

Get em while they're hot guy's!
   
  Vacuum Tube Valley DIY Tube magazine.
  Publisher ceased to exist and now the complete set is available for download.
   
  A 20 Volume Set.
  http://tinyurl.com/nshl92k
   
  I am grabbing it now and the site is slow, so for those who want to wait I can Drop Box it for you when it's done.


----------



## gibosi

Quote: 





iron58p said:


> First of the three settings on the manual ( to use WE408A ), for what kind and family of tubes can be used ?
> 
> Using with Telefunken EH900S don't work, it's normal ?


 
   
  The Telefunken EH900S is not a 408A tube, The Lorenz 6AV6/EBC91 is not a 408A tube. So of course, it is normal that they do not work
   
  Again, 408A tubes have 20 volt heaters. Only 408A tubes can be used in this setting. No other tubes can be used. If you keep trying to use other tubes in this setting, you might kill the tube or worse, you might kill your amp.
   
  If you want to try 408A tubes.... Western Electric 408A, Northern Electric 408A, and Sylvania 408A are easy to find. And the Philips Miniwatt TS62/408A you recently asked about can also be used. Again, ONLY 408A tubes can be used in this setting.


----------



## MIKELAP

Quote: 





trolldragon said:


> Get em while they're hot guy's!
> 
> Vacuum Tube Valley DIY Tube magazine.
> Publisher ceased to exist and now the complete set is available for download.
> ...


 
  Thanks for the link very interesting stuff .


----------



## mordy

Hi Siles 1991,
   
  Agree with Oskari here about the glow from the heaters. It is not unusual for one tube to glow a little less than the other, usually dependent on how the internals of the tube were put together. If you cannot hear any difference between channels, there is nothing to worry about. Enjoy your new amp!


----------



## TrollDragon

Quote: 





mikelap said:


> Thanks for the link very interesting stuff .


 
  Most Welcome!
   
  Here is a 570MB zip of the complete set if you want to get it in one download.
  http://db.tt/P0jXOSnl


----------



## siles1991

Quote: 





mordy said:


> Hi Siles 1991,
> 
> Agree with Oskari here about the glow from the heaters. It is not unusual for one tube to glow a little less than the other, usually dependent on how the internals of the tube were put together. If you cannot hear any difference between channels, there is nothing to worry about. Enjoy your new amp!


 
  Alright thanks guys for the quick answer was worried.
   
  Is there a way to strap the Sylvania 5915? They sound a bit boring...I like my Valvo E91H with 1/7 strap. Going to re-try the TS 6ah6wa once more to see what balance I like.
   
  Yeah the TS's are way better than the 5915's and the Valvo E91H regardless of strapping. The TS 6AH6WA bass has just so much kick in it while the others pales in comparison to the quality of bass IMO. E91H is about equal in mids while the Sylvania 5915 feels a bit laid back but I can't seem to feel the soundstage that everyone talks about. For the highs all are about equal while as higher strap goes e91h tends to get too fatiguing.


----------



## Acapella11

Quote: 





mordy said:


> Hi Acapella 11,
> 
> ...
> 
> ...


 
   
  Thanks Mordy and congrats! I am glad you did it and do appreciate it plus I basically agree from my listening experience. 6N6P-IR is the underdog of power tubes for the LD at a fair price!


----------



## Acapella11

Quote: 





gibosi said:


> Yes, this is a mistake. Acapella11 maintains this chart, so I will send him a PM.


 
   
  Fixed! Thanks for the hint.
   
  Quote: 





> Originally Posted by *Iron58p* /img/forum/go_quote.gif
> 
> *Telefunken EH900S*/5915 ( EF95 config ) sounds different from Tesla, more soundstage and more details, mids and highs are very clean and extended ,my surprise in that bass aren't too strong for my hears.
> More hight grade of trasparence .
> ...


 
   
  Do not cut the Telefunken EH900S pins 1 and 7. It is a 6BY6-type heptode. This will destroy it! Just strap them, meaning: create a short and thin multi-stranded wire to connect the pin holes in the socket for the pins 1 and 7 (see page 77). You can use this also to connect the holes for pins 2 and 7 but of course, you do not need to do so.


----------



## MIKELAP

Quote: 





acapella11 said:


> Thanks Mordy and congrats! I glad you did it and do appreciate it plus I basically agree from my listening experience. 6N6P-IR is the underdog of power tubes for the LD at a fair price!


 
  Do power tubes  absolutely have to be matched  i can get get some 6N6PIR but not matched .$14.00 each personnaly i always bought matched pairs what do you guys think .


----------



## Iron58p

i know
   
  really never i was thinking to cut pins on my Telefunken, sounds great.
   
  Today i'm lucky, as i wrote before, and i'm learning some things that i don't know until that moment.
   
  And another good news is that Pro-skit is shipped, so i can cut pins 5 and 6 on my 6AV6 and try it.
   
  Is more safe next time that i will receive a tube to ask before make something wrong, it will be noisy, but better then destroy LD 
	

	
	
		
		

		
		
	


	



   
   
  I was looking for another Telefunken, EBC91, but until now i haven't seen.


----------



## mordy

Hi Mikelap,
   
  Read somewhere that it is much more important to match power tubes than driver tubes. As far as I am personally concerned, matching in this context means the tubes are from the same batch/manufacturing date. Seems that you need very sophisticated and expensive equipment to truly measure the tubes for perfect matching and most sellers do not have this type of equipment (Amplitrex).


----------



## mojorisin35

Quote: 





mikelap said:


> Do power tubes  absolutely have to be matched  i can get get some 6N6PIR but not matched .$14.00 each personnaly i always bought matched pairs what do you guys think .


 

 mike
  would you pm me where you are getting these from as i too am also looking for a pair at a reasonable price
  thank you
  gary


----------



## gibosi

Triodes: FIVRE and Toshiba 6AV6/EBC91
  
 At the time I ordered these, one pair manufactured in Italy and the other in Japan, I was quite excited as I thought they would certainly be different than any of my other triodes. Well, I was wrong.... Both of these triodes sound virtually the same as my GE 6AV6! I would guess that after WWII, GE must have been strongly involved with FIVRE in Italy and Toshiba in Japan as both countries were scrambling to rebuild their electronics industries. Again, I could not reliably distinguish between these tubes.
  
 Unfortunately, one of the Toshibas has a bit of noise which is detectable only between tracks. But then again, as I have three pairs of FIVRE and one pair of GE, it is easy for me to consign the Toshibas to the ever growing "not good enough" pile. lol 
  
 Edit: And the fact that the FIVRE and the Toshiba sound virtually the same as the GE 6AV6 is not at all a bad thing. IMO, my 1958 GE 6AV6 with the top square getter is an excellent tube.
  
 FIVRE
  

  
 Toshiba
  

  
 GE


----------



## mojorisin35

iron58p said:


> I received today a pair of matched Tesla 6F32-6AK5
> 
> Now i'm burnin in
> 
> ...


I

These were by far my favorite tubes in the ef95 family give them time and they open up and the brightness crisps up...


----------



## Iron58p

Received today micro cutting plier Pro-skit, cutted pin 5 and 6 on my Lorenz EBC91 (6AV6), it's very easy and safe.
  
 Again this tube sound great (setting EF92 ) from the first moment, and i can tell : woww, and i smile!!
  
 Medium/high transparent, clean, open and bright as the sun, and lots of details.
  
 I like how guitars acoustic and electric sounds with this tube.
  
 On my hears low bass are be lacking.
  
 But for my taste, preferred to Tesla and Telekunken ( both sounds very good ) of Yesterday : very close to Grado sound.
  
 Uff, i must make burn in with many tubes that i have received, i know.
  
  
 Received now ( please control setting  ) :
  
  
 Miniwatt Z&I EH90  ( (setting EF95 or EF92 )
  
  
 Jan GE 5654W ( setting EF95 )
 On the box in the photo there is written 5654W, bot on the box received and on the tube appears only 5654.
  

  
  
 CV4015 KQDD/K, no name but seller write it in description as Mullard, setting on EF92


----------



## gibosi

iron58p said:


> Reaceived now ( please control setting  ) :
> 
> Miniwatt Z&I EH90  ( (setting EF95 or EF92 )
> 
> ...


 
  
 Since the Miniwatt EH90 is a heptode, you can configure this tube in 4 different ways: EF95 unstrapped, EF92 unstrapped, EF95 1-7 strapped and EF95 2-7 strapped. So get a little piece of stranded wire and try all 4 to determine the best setting for your ears and equipment.
  
 JAN GE 5654W. Yes, EF95 is the correct setting. I seriously doubt that a GE 5654W sounds any different than a GE 5654  But if you are unhappy about this, you might want to tell the vendor that you got the wrong tubes. 
  
 CV4015. Yes, EF92 is the correct setting.


----------



## Iron58p

I want to tell a great thank's to all members of this thread that let me know that exist other tubes different and better then stock, and to all that have helped me and other who did reviews.
  
 I can tell that is true, any tube that i have leastened until now is without dubt better


----------



## siles1991

These are my Sylvania 5915's 1/7 strapped in the MKIV SE! These are the Televania's iirc? I removed the tube guard screws and swung them around because they get in the way of my tube rolling and also when I'm trying to change the straps.
  

 The 6N6P-IR!!!!

 The long wait is over my MKIV SE T.T it's really big, my Fostex T50RP as well!


----------



## Audiofanboy

siles1991 said:


> These are my Sylvania 5915's 1/7 strapped in the MKIV SE! These are the Televania's iirc? I removed the tube guard screws and swung them around because they get in the way of my tube rolling and also when I'm trying to change the straps.
> 
> The 6N6P-IR!!!!
> 
> The long wait is over my MKIV SE T.T it's really big, my Fostex T50RP as well!


 
  
 Good stuff, siles; nice choice of tubes at any rate! 
  
 I'm actually back to using my Tele/vanias (R), 1-7 strapped at the moment. Great tubes, for sure, much more mellow and large-soundstaged than the even more recent offerings.
  
 I kind of got annoyed at my latest pairs of tubes last night... Basically, _none_ of them sounded right to me at this point (I'll take this chance to mention that I was _not_ intoxicated or otherwise impaired at the time, just a usual business day evening lol); NONE of them! I'm not sure whether some tubes evolved a bit after the burn-in period, or if part of the "magic" wore off, but these tubes just weren't working for me... They haven't been since I came back from vacation actually.
  
 The "Haltmens" (R) -Haltron 6BE6 that look like Siemens tubes but should have been made by Toshiba (as people say on Facebook about relationships: "it's complicated"), while very nicely detailed, just lack any sort of warmth, and not just in the midrange. They simply don't allow me to enjoy my music that much, at least non-electronic genres. That's unstrapped mind you.
  
 The Belgian M.B.L.E. EH90 are still warm and cozy but probably too much so, and lack the neutrality and absolute detail I seek in good tubes. At least, they're pleasant, but they _may_ or _might _not quite be over the "best in class" line.
  
 The Mullard Blackburn EH90 seemed like they had the most potential in the bunch -and they do, no doubt about that- but again, they just don't give me the same listening pleasure as other tubes... Too dry? Maybe. Too balanced? Not so sure about that. Too detailed? Actually, not _that_ detailed, but more than enough. Basically, the toe-tapping factor just isn't there with these; at least it hasn't been for the last few days I was using them. It might come back to them at a later time, but for now, I need to go "back to basics" as gibosi did with the 6485 and 8425A tubes.
  
 (For the last two tubes, my remarks apply both to unstrapped and 1-7 strapped settings; 1-7 setting just being even thinner and less toe-tapping, but having other advantages)
  
 So, I went back to my latest "milestone" tube, and that was the Tele/vania -Sylvania- 5915/EH900S. And I'm glad I did, these are still fine tubes -and much more easygoing than the Siemens derivatives above.
  
 At first, these 5915 seemed a bit tame compared to the recent tubes, but they are every bit as detailed -and probably more so given that much is spread over a huge yet natural soundstage- and qualitative. Again, that soundstage will make even the most closed headphones sound large and deep without taking intelligibility away. Treble is noticeably softer -in a good way- than the tubes above, mids are finally _alive_ and musical, while bass is OK but not best in class. That was unstrapped mind you. 1-7 strapped, things tighten up quite a bit; enough that some acoustic tracks start sounding thin -the 1-7 curse!- but still nicer for most musical genres as the tubes are made more dynamic. These do have quite a bit less gain than other heptodes; enough that on some applications, I need to go over the 12 o'clock point on the volume pot, which I do not like to do.
  
 So yes, if you see where I'm going with this, even the strapped 5915, while easygoing, are still not quite perfect and balanced imho. In fact, I'm starting to realize that none of my recent heptodes sound truly toe-tapping, detailed _&_ balanced; none of them. And that's a bit of pickle, as far as I'm concerned, as I just can't trade musicality for detail or technical specs. The same thing happened -granted tenfold- with most triodes I tested.
  
 I may temporarily try and go back to pentodes -dual control or not- if only to remember just what it is I was looking for in terms of sound quality and musicality.
  
 Has _anyone else_ had a similar experience with _some_ heptodes, strapped or not? I'm kind of interested now.


----------



## siles1991

audiofanboy said:


> Good stuff, siles; nice choice of tubes at any rate!
> 
> I'm actually back to using my Tele/vanias (R), 1-7 strapped at the moment. Great tubes, for sure, much more mellow and large-soundstaged than the even more recent offerings.
> 
> ...


 
 I share the same experience with you on my pair of Valvo E91H, at first they seemed really good when compared to my voskhods which have now a home where they are used more often. At first hearing the Valvo's sounded like a huge improvement and after going from unstrapped to 1/7 to 2/7 I was amazed. But as I listened longer I felt that it was "dry" like your experience. Than I had my lot of 5 TS 6485 which had finally reached! They sounded detailed, alive, musical but lacked something but were by far the best tubes i've heard most definitely.
  
 Than shortly came the Tele/vania 5915's, unstrapped I just didn't like it, it was too laid back and didn't have the energy I liked so I decided to strap it to 2/7 and enjoyed the new found energy, but I wondered how it would sound with the 1/7 so quickly changed the strap and now am enjoying the balanced sound. I feel that the 1/7 is the best strap if you wish to fully enjoy the wide soundstage of the Tele/vania 5915's.
  
 Currently awaiting for the RCA 6DT6A's which technically should be similar to the current "tube in the spotlight" RCA 6DT6 a.k.a Detox


----------



## mordy

Hi AFB,
  
 There are days when nothing sounds really good, and other days when the same tubes sound very good. I have also found that after a hiatus of listening, it takes time to get into the groove again.
  
 In general, I found that things sound best late at night, maybe because there is less electric and electronic grunge passed through the electric grid.
  
 Then you have what I call "the new normal."  What elicited oohs and ahs and WOW! yesterday, becomes the norm now and does not impress as much as in the beginning.
  
 So what to do to bring back the excitement and enjoyment? Play a really well recorded track with your favorite combination of tubes and just enjoy the music. Listen for new details emerging, estimate how wide the sound stage is (in my case how far outside the speakers the sound seems to emanate, tested with closed eyes and pointing a finger to where the sound seems to come from - I mean, u need a little exercise while listening), listen how realistic the cymbals and bass drum sound. With a good recording and great tubes the magic comes back....
  
 My present favorite combination is the IR tubes with DTox. A very sweet mid range, plenty of detail, and all the punch and slam and shimmer I want in the lows and the highs.
  
 Based on what you have written my impression is that you like a somewhat dry presentation with very detailed treble. If this is correct, you have to find the tubes that highlight your taste. As for me, if the bass is not up to my standards and taste of slam and attack, the tube is not for me. The mid range must also be sweet and no sibilance in the treble.
  
 I am sure that with a little patience you will re-discover the excitement and magic of listening to the LD. Good luck!


----------



## gibosi

I have found myself pulled back to triodes.... After spending most of the last week with the GE 6AV6 and the FIVER and Toshiba clones, last night I put in the Mullard Blackburn EH90s, EF95 1-7, but in comparison to these triodes, felt that the treble was lacking. Switched them to EF92, and yes, now they sounded like triodes!  But still not quite there.... So I have happily gone back to my GE 6AV6....
  
 Again, I have a pair of 1958 GE with a top-mounted D-getters. Perusing eBay, it looks like almost every GE 6AV6 looks different from every other. There is a tremendous variation in the construction of these tubes, and I do wonder if they all sound essentially the same.....


----------



## Audiofanboy

Well, wow, I didn't expect to get so much feedback withing the hour lol! Thanks for the help and impressions, I appreciate it.
  
 I do feel that I should just kick back for a couple a days and go even further back to, say, the TS 6485; just spend an evening or two listening to music. But then again, I also feel that going back to my mystery Pinnacle EBC91 -which are still a mystery at this point, oddly enough- might also do me some good.
  
 Interestingly, and that had occurred to me this morning, my last listening session was late in the afternoon yesterday, and not at night/very late at night as per usual. It's hardly the first time I use my LD or gear before dinner, but still, I have noticed in the past how it doesn't sound so much "bad" as it just brings out the worst in the gear when I use it during the day, as the power is definitely worse. Basically, it's akin to listening to the same gear but in sub-par conditions.
  
 Still, I think that it doesn't detract from my issue with the current tubes though; my last listening session just emphasized it. So, It do need to go back to the drawing board a bit. Yes, I do like not-too-tubey tubes -aka a little dry- but I also enjoy the tube sound exactly for that, a slightly warm and physiological sound.
  
 Gibosi might be right: I need to go back and listen to all my previous "staple food" tubes, regardless of their type. I get the feeling that the 6AV6 type was never really given the attention it deserved on the thread, unlike some pentodes that immediately got raving reviews. I ought to backtrack a bit and re-listen to my previous best-in-class tubes.
  
 I do hope I'm being too annoying with my tube ramblings... Pardon me if I am lol! I know I personally like to read about people -head-fiers'- "path" or "road" towards better audio, and all the steps -including the bad ones- in the process; not everyone does.


----------



## MIKELAP

gibosi said:


> I have found myself pulled back to triodes.... After spending most of the last week with the GE 6AV6 and the FIVER and Toshiba clones, last night I put in the Mullard Blackburn EH90s, EF95 1-7, but in comparison to these triodes, felt that the treble was lacking. Switched them to EF92, and yes, now they sounded like triodes!  But still not quite there.... So I have happily gone back to my GE 6AV6....
> 
> Again, I have a pair of 1958 GE with a top-mounted D-getters. Perusing eBay, it looks like almost every GE 6AV6 looks different from every other. There is a tremendous variation in the construction of these tubes, and I do wonder if they all sound essentially the same.....


 
 I got 6 pairs of 6av6 from different manufactures and i would say theres no or small differences between them they all have about same sound signature.to these olden ears.


----------



## Acapella11

You describe the Tele vanias EH900S as tame but detailed. I agree with my Telefunken EH900S, they are as well. Here is another one but slightly different. The Sylvania JAN 5750 (= 6BE6W) are alike but dark.You think they are maybe a bit too dark. Then you listen and are surprised about the huge stage and details pouring at you. Once you are used to it, they give a lot. I felt this was an experience a bit similar to yours.
  
  
 Re balanced power tubes. Sounds OK, that they should be better matched than driver tubes. However, I doubt even your driver tubes as they come with the LD were perfectly matched. Also, it is not so easy to match if do not have a huge stash of tubes. I bought my IRs not matche as I couldn't find anyone matching them. They are date matched though and I am perfectly happy with them.


----------



## MIKELAP

DISCLAMER: DO NOT TRY THIS AT HOME.  This is my reach for the sky setup for 6ah6 tubes EF92 amp to EF95adaptor to 6AU6 adaptor .


----------



## TrollDragon

mikelap said:


> DISCLAMER: DO NOT TRY THIS AT HOME.  This is my reach for the sky setup for 6ah6 tubes EF92 amp to EF95adaptor to 6AU6 adaptor .


 
 Nice!


----------



## TrollDragon

Well I put the halo getter RCA 6BY6's in strapped at 2-7, a lot more Bass presence and sounding good so far.
  
 Going to need a new panel mount jack for the MK IV since I didn't get the SE version the headphone jack was said to be of lesser quality, there's an understatement.
 I had noticed if you lightly push the headphone plug to the left you loose the right channel, I took the jack out as far as the wires would let it come and it is SERIOUS JUNK.
  
 So one of these will be ordered pronto.
Neutrik NJ3FP6C-B

 It shouldn't be any problem to change, I'll see if I can get some board pictures when I have the MK IV apart.
  
 What are the Tung Sol 6AH6WA like?
 Would I like them?


----------



## gibosi

trolldragon said:


> What are the Tung Sol 6AH6WA like?
> Would I like them?


 
  
 The quality versions of the Tung-Sol 6AH6, the 6AH6WA and the 6485, are superb tubes. And I am quite certain that you would like them. Here is some discussion from last April, about the time of their discovery :
  
 http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/1065#post_9365551
  
 http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/1125#post_9384251


----------



## TrollDragon

Thanks gibosi, I shall indeed look into a pair.


----------



## Iron58p

Received now a Soviet tube 6A2P  = 6BE6
  

  
 I don't see it's name, may be Svetlana ?


----------



## Nic Rhodes

It has the old Svetlana logo on it.


----------



## Iron58p

Thank's
  
 Now i'm listining on EF92, and sounds great


----------



## KR500

Received my pair NOS RCA 6DT6 tubes yesterday from the feebay seller for $9 shipped.
 Okay, plugged them in and put on "Don't Talk To Strangers" by the Beau Brummels on Rhino and contrasted them with my favorite tube so far, the Mullard milspec EF95.
 The 6DT6 sounds very good so far, it's the EF95 setting and I can't strap the 1-7 mod until I locate a bit of 25 stranded copper wire for a jumper. Guess I should have saved an old Walkman headphone cord after all . I have a large parts drawer but no bits of fine cable . Maybe a Cat5E cable would be a source ?
 Anyway , the  6DT6 soundstage is different and the twelve string guitar , tambourine and crash cymbal sound better than the Mullard.... more body a , bit more definition. Me likey . It's not the precious....... but looking forward to listening to them some more.
 But, dang it , a hum in the right channel. I touch the tubes just to make sure they're seated properly and notice that the proximity of my hands acts like an antenna as far as diminishing or increasing the hum in either or both tubes. Not sure if the tubes are microphonic or they're affected by the large transformers on my SET amp that sits next to it ?
 So far my other tubes haven't exhibited any hum so maybe will try moving the headphone amp away from the other amp and see what happens to the hum issue.


----------



## Iron58p

Svetlana are a very good surprise for me : balanced, open sound, clear, only a little harsh on hights, but i confide that after burn it will go away.
 It's a very small problem for my hears.
  
 In origin, i don't give 1 cent, but now they have surprised me, i can put them in the hight part of my ranking,
  
 Until now, all the tubes that i have received i really like


----------



## Iron58p

But now i become curious !!
  
 i want to know for every brands the year of manufacture, there are links avalilable ?


----------



## hypnos1

audiofanboy said:


> Good stuff, siles; nice choice of tubes at any rate!
> 
> I'm actually back to using my Tele/vanias (R), 1-7 strapped at the moment. Great tubes, for sure, much more mellow and large-soundstaged than the even more recent offerings.
> 
> ...


 
  
 Hi AFB.
  
 Sounds like your vacation has had unforeseen consequences...poor chap! Actually, I reckon you are experiencing overload in trying to catch up with yourself...just a thought...
  
 After a little 'reminiscing', you might want to give the Blackburns another go - but in 6-7. Thanks to the experience of one of our esteemed colleagues I was tempted to indulge, and in my system at least the result was encouraging - there was nothing 'thin' going on in MY ears!
 At first, with the M.B.L.E.s, the extras were a little harsh for my gear. But after swapping back to the Bs the harshness disappeared, and the nice instrument separation/placement returned, but now with added body and 'sparkly' treble.
 So perhaps you will keep this option in mind - when the dust settles!!
  
 GOOD LUCK and happy rolling...


----------



## mab1376

Anyone see this?
  
 http://www.ebay.com/itm/Little-Dot-MK9-6N9P-6080-2-tube-OCL-Tube-Headphone-Amplifier-AMP-/251319619395?pt=US_Home_Audio_Amplifiers_Preamps&hash=item3a83d10f43


----------



## MIKELAP

Tempting!
 Quote: 





mab1376 said:


> Anyone see this?
> 
> http://www.ebay.com/itm/Little-Dot-MK9-6N9P-6080-2-tube-OCL-Tube-Headphone-Amplifier-AMP-/251319619395?pt=US_Home_Audio_Amplifiers_Preamps&hash=item3a83d10f43


 
 Nice tubes. How much is it cant see ebay add. found price $530.00 free shipping rightttt....


----------



## MIKELAP

those are the 6080's about same pricerange

  
 They say the 6n9p chinese tubes are $20.00 a pair and they say the  6SN7 are compatible with the 6N9P but not same price more like $50.00 + a pair + shipping not in the same pricerange we are use to!


----------



## gibosi

mab1376 said:


> Anyone see this?
> 
> http://www.ebay.com/itm/Little-Dot-MK9-6N9P-6080-2-tube-OCL-Tube-Headphone-Amplifier-AMP-/251319619395?pt=US_Home_Audio_Amplifiers_Preamps&hash=item3a83d10f43


 
  
 I would be cautious...  It does not appear that this vendor is an "Authorized Little Dot Reseller" and thus it is likely that there will be no warranty through Little Dot if you buy from this vendor:
  
 http://www.littledot.net/forum/viewtopic.php?f=9&t=439&sid=02a9075fd96699d73ea5124f0d5c5ee8
  
 It isn't showing up yet on Little Dot's official site:
  
 http://www.littledot.net/forum/viewforum.php?f=9&sid=02a9075fd96699d73ea5124f0d5c5ee8
  
 However, it is coming soon.
  
 http://www.littledot.net/forum/viewtopic.php?f=3&t=2528&sid=02a9075fd96699d73ea5124f0d5c5ee8


----------



## Audiofanboy

Yup, I discovered the MK9 about a week ago, and it immediately aroused my curiosity, as it is supposed to basically be half of the -_powerful as hell_- MKVI+. I was waiting for someone else to pick up on it, knowing that the day would soon be at hand!
  
 Still, while the specs seems really nice at first for that amp, I have to really wonder just why the hell it isn't that powerful...
  
 "_The maximum output power of 5):
 A. 300 mw (600/300 ohm)
 A. 300 MW (600/300 Ohm)
 B. 350 mw ( 120 ohm)
 B. 350 MW (120 Ohm)
 C. 250 mw ( 32 ohm)
 C. 250 MW (32 Ohm)
 6) output impedance: 32 ohm - 600 ohm_"
  
 Imo, not particularly interesting power-wise compared to the good ol' MK III & IVs, especially factoring in the price of the best tubes for the amp (trust me, I checked that out the minute I found out about the amp lol). For half a k$ and another k$ worth of premium tubes, I would have like to find half the power of the MK VI+, that is, "_5W per channel in 120 ohms_"!
  
 So, yes, I am a bit perplexed by this new LD offering, despite its obvious advantages.
  
 Hypnos, thanks for the cheering up; worry not lad, I'll get better! I already am, in fact, as I just got my Canadian order of Japanese heptodes: 6 Haltron -Toshiba- 6CS6/EH90 -indeed identical to the "foreign Siemens" seen around here- and what turned out to be 4 Canadian General Electric, _probably made by Marconi in Canada_, 6DT6 tubes (actually marked "_6DT6 Canada_"). I had actually ordered CGE _made in Japan_, supposedly by Toshiba, 6DT6, but there was an obvious problem in my order, which I will attempt to get fixed asap. Seller has not been that responsive at this point, which annoys the living crap out the me (I have had a mistake made on almost half of my tube orders in the last 4 months; _how hard can it be to get an order right...?_ If you can't get it right, then just don't sell tubes; sell, I don't know... Jam, green beans or somekind of vintage pyjamas instead... There's tons of other niche markets those ebay sellers could be focusing on, and actually getting right...)
  
 Regardless, I have plugged in those _ToshTronMens_ -Toshiba-made Haltron-branded Siemens-lookalike- in for a good burn-in, and have high hopes that they will entertain me for 20 hours or so, which is the usual amount of time that tubes seem to be useful to me these days... Much money spent, not that much use... They seem like excellent tubes from the start though!
  
 I really need to figure out a way to use that grid 3 as the sole signal grid though -with g1 tied to the cathode instead- as I'm still pretty sure there is an untested potential in using the tubes that way.


----------



## john57

The MKVI+ is a balanced amp and the MK9 is single ended. Typically you can get up to twice the voltage swing using the balanced outs as compared to single ended outs. It depends on the circuit design as well.


----------



## Audiofanboy

john57 said:


> The MKVI+ is a balanced amp and the MK9 is single ended. Typically you can get up to twice the voltage swing using the balanced outs as compared to single ended outs. It depends on the circuit design as well.


 
  
 Definitely, but the difference in specs here is pretty large and doesn't quite account for the single ended vs. balanced difference... Which is why I'm kind of curious as to where the true difference lies. Even a single ended amp using these kind of power tubes should be able to pump close to 1W into high impedance headphones...?


----------



## Edgard Varese

iron58p said:


> Svetlana are a very good surprise for me : balanced, open sound, clear, only a little harsh on hights, but i confide that after burn it will go away.
> It's a very small problem for my hears.
> 
> In origin, i don't give 1 cent, but now they have surprised me, i can put them in the hight part of my ranking,
> ...


 
 I've got a set of ten of those on the way, I'm really looking forward to rolling them in.


----------



## mab1376

audiofanboy said:


> Definitely, but the difference in specs here is pretty large and doesn't quite account for the single ended vs. balanced difference... Which is why I'm kind of curious as to where the true difference lies. Even a single ended amp using these kind of power tubes should be able to pump close to 1W into high impedance headphones...?


 
  
 yeah, the VI+ pumps out 5w per channel into 120 ohms, this should 2.5w per channel into 120 ohms unless there's something drastically different with the topology.


----------



## TrollDragon

Well the USAF 6AH6WA's are on their way 6130 61-15 USA7 on both tubes should be from 1961 week 30.
 Now the excruciating wait begins!
  
 Also the black Neutrik replacement headphone jack is inbound as well.


----------



## gibosi

A pair of RCA 6HM5/6HA5/EC900 RF triodes arrived today. These are short, squat little tubes, very much like the standard 6AK5. Interestingly, when I began to inspect them, I noticed "Made in Germany" printed on the glass. Inspecting further, I found Philips tube codes! These RCA tubes were manufactured in 1964 by Siemens!! Finally, I have a pair of real Siemens!! lol 
  
 Anyway, these are plug and play in the EF95 setting, no strapping is required, and I am happy to report that they do in fact light up and play! The bass seems quite strong... Will report back later.....


----------



## Advil

I'm wondering if 161's in my old LDII++ would sound the same as those tubes in an MKIII... worth the upgrade?


----------



## siles1991

im kind of stumped with this is the Lepai TA2020 a DC coupled amplifier I was planning to pre amp out into this amp but I can't tell whether it is or not?


----------



## Audiofanboy

Ok, after leaving my Haltron-Toshiba 6CS6 aside for a little while (they're excellent tubes but they have the exact same issues we've mentioned before: too cold), I plugged in and burned-in my -sent to me by mistake- GE Canada 6DT6A, probably made by Marconi in, well, Canada.
  
 At first, they sounded detailed, balanced, but the bass was all flabby; that's 2-7 strapped mind you, suppressor grid (grid 3) -considered a secondary control grid here- connected to the cathode; text book example.
  
 After 10 or so hours, the bass tightened up and the tubes were still detailed, but something was amiss, music sounded a bit "coarse". So, I pulled them out, and tested them 1-7 strapped, so signal grid (grid 1) connected to the suppressor/secondary control grid (grid 3), meaning no more suppressor grid actually suppressing secondary emissions (may or may not matter in triode-ish mode).
  
 Anyway, the tubes sounded much better that way. Slight soundstage improvements, better and more coherent micro-detail, more controlled bass, the usual "dual-controlled" extra treble but without the heptode thinness. So, pretty good, though too early to call these top-tier, which I'm not sure they are; they're just pretty good and balanced right now.
  
 Since I intended to plug some good ol' triodes later today, I put the amp back into EF92 jumper mode, and put those 6DT6A back in with no strap. Well, surprisingly enough, this is my favorite setting for those tubes (that's now close to 15 hours of burn-in mind you; I have no idea how the lot of you get tubes burned-in so fast lol, like 25 hours over 24 hour days!).
  
 EF92'd, the tubes sound much more controlled. Staging and instrument placement is clearly improved, micro-detail everywhere. Sound may be better balanced than 1-7 strapped, but ultimately still a little coarse, like, a bit of glare in some frequencies. Most likely something that would go away with a longer burn-in; but I don't expect these to become god-tier tubes or anything, just somewhere between good and excellent -and more easygoing than most heptodes!
  
 Interestingly, these 6DT6A have a _much_ higher gain than any of the heptodes I tested -even strapped. It also has a much higher gain than the only other dual control pentode I've tested in the past, the 6GX6/6GY6. We're talking about a volume that's about half way between a 6AV6 -mu=100- and a 6CS6 -mu=?? probably less than 40 triode-strapped. I'd say it easily hits a mu of 50 or more, more than regular pentodes like 6AU6 for instance.
  
 Most people here don't care much about gain, but I do; and having tubes like the Sylvania 5915 needing 1 o'clock on the volume pot to watch a video or 10 o'clock for music just doesn't sit well with me -especially with low impedance orthos. Not, when 10 and 8 o'clock are enough with high-mu triodes!
  
 Speaking of triodes, my goal for today was to give my mystery Pinnacle 6AV6 tubes a listen after weeks of using different tube types or using no tubes at all. So, I plugged them back in earlier and, yeah, I have to admit that these might still be my best tubes, or at least still on my top-tier list. They're realistic, basically; and realistically detailed and staged. I can't say they're the most musical tubes I own -pentodes like the 6485 do this very well, perhaps at the cost of some realism or precision- but they're transparent instead, which to me is just as important.
  
 For a while, I thought that some of those heptodes would turn out to be my favorite tubes, but going back to other tube types, I can tell that something is lacking in these tubes; detail without realism, or something like that? I need to do some more comparative listening to validate my impressions...


----------



## MIKELAP

siles1991 said:


> im kind of stumped with this is the Lepai TA2020 a DC coupled amplifier I was planning to pre amp out into this amp but I can't tell whether it is or not?


 
  
 It seems that littledot mk3 and dc coupled amps is a major NO NO you could potentialy blow your speakers if a tube goes out could send a surge of DC and potentialy blow your speakers i contacted David Zhezhe of littledot regarding this and a vintage pioneer amp SX750  i have ,I wanted to use littledot mk3 as preamp and he said not to do it and heres what a fellow headfier told me regarding this please  download to enlarge sorry.Its better to be shure or dont risk it. Hope this help but looks like you already know regarding this just in case you dont.


----------



## KR500

> Well the USAF 6AH6WA's are on their way 6130 61-15 USA7 on both tubes should be from 1961 week 30


 
 I just got mine in the mail , 61...same year. They look nice
 well protected in a hard cardboard tube wrapped in bubble wrap
 Just have to find some thin copper wire to make a jumper. Just have never saved any bits of wire that fine in my parts bins


----------



## KR500

> I put the amp back into EF92 jumper mode, and put those 6DT6A back in with no strap


 
 I thought from the chart on page 77 that the 6DT6A were supposed to be in the EF95 setting ?
 no, yes , maybe ?


----------



## gibosi

advil said:


> I'm wondering if 161's in my old LDII++ would sound the same as those tubes in an MKIII... worth the upgrade?


 
  
 Can you use the same power tubes in the MKIII? If so, then I think you should expect your 161s to sound the same. If the MKIII uses different power tubes, then there will likely be a difference.... 
  
 Can you use EF95 tubes in your LDII++? If not, then I believe the MKIII is a very worthwhile upgrade.


----------



## gibosi

kr500 said:


> I thought from the chart on page 77 that the 6DT6A were supposed to be in the EF95 setting ?
> no, yes , maybe ?


 
  
 The 6DT6 and 6HZ6 are very similar to heptodes, and therefore, can be used similary. That is, there are four possible configurations: EF95 unstrapped, EF95 1-7 strapped, EF95 2-7 strapped and EF92. I suggest you try them all to see which works best for your ears and your equipment.


----------



## TrollDragon

kr500 said:


> I just got mine in the mail , 61...same year. They look nice
> well protected in a hard cardboard tube wrapped in bubble wrap
> Just have to find some thin copper wire to make a jumper. Just have never saved any bits of wire that fine in my parts bins


 
  
 Excellent!
 Since the 2-7 strap is the only way to use the 6AH6 as per page 77, I'll probably solder the wire in place on the tube permanently. Some 30 awg wire wrap wire should attach nicely to a well cleaned pin, two wraps around the pin then solder.
  
 On a side note, I removed the 2-7 strap from the 6BY6's as the Bass was increased in that mode but it was way too boomy for me, they are back in EF95 mode.


----------



## TrollDragon

I'll have to inquire with the guru's over on DIY Audio and see if there is not some economical way to make a little box to go between the LD's pre-amp out's and a power amplifier, either with some blocking caps or a 1:1 transformer that does not cost $100 to implement. 
  
 The quest is a foot for a solution!


----------



## gibosi

trolldragon said:


> Excellent!
> Since the 2-7 strap is the only way to use the 6AH6 as per page 77, I'll probably solder the wire in place on the tube permanently. Some 30 awg wire wrap wire should attach nicely to a well cleaned pin, two wraps around the pin then solder.
> 
> On a side note, I removed the 2-7 strap from the 6BY6's as the Bass was increased in that mode but it was way too boomy for me, they are back in EF95 mode.


 
  
 Yes indeed, 30 awg wrapping wire works great.


----------



## TrollDragon

gibosi said:


> Yes indeed, 30 awg wrapping wire works great.


 
 That is why I just love this thread and the people in it, if it's been done you'll have a pic or solution within minutes!
 Thanks gibosi! Looks perfect.


----------



## KR500

Does copper only stranded wire have to be used ?
 I have some 25 guage stranded wire but it's not copper
 Cut apart an old cheapy RCA interconnect but it's too round and fat to use
 never mind , just located a short Cat5e cable in the boneyard and cut it apart to make a jumper


----------



## MIKELAP

kr500 said:


> I just got mine in the mail , 61...same year. They look nice
> well protected in a hard cardboard tube wrapped in bubble wrap
> Just have to find some thin copper wire to make a jumper. Just have never saved any bits of wire that fine in my parts bins


 
  
 What i did is  remove strands from the wire to make it smaller


----------



## siles1991

trolldragon said:


> I'll have to inquire with the guru's over on DIY Audio and see if there is not some economical way to make a little box to go between the LD's pre-amp out's and a power amplifier, either with some blocking caps or a 1:1 transformer that does not cost $100 to implement.
> 
> The quest is a foot for a solution!


 
  
 for me i dont even know if the lepai ta2020 is dc coupled or not i dont know which is which


----------



## gibosi

gibosi said:


> A pair of RCA 6HM5/6HA5/EC900 RF triodes arrived today.


 
  
 After about 15 hours of burn-in, casually listening every so often, I think I can say that these are pretty good tubes. Unlike the 6AQ6/6AT6/6AV6, these do not have a treble-oriented analytic presentation, but instead, are more similar to pentodes. The highs are definitely there, clean and detailed, and musical. Moreover, the bass on these is quite good. 
  
 I do not feel that these are at the same level as the TS 6485 or GE 6AV6. However, after only 15 hours and rather casual listening through old ears, this is more of a hunch than a critical evaluation, and I hope that others with betters ears and gear will check these out.
  
 And I have one more pair of 6HM5 coming. A pair of GE 6HM5 "Made in Great Britain". From the pictures provided by the vendor, these are not short and squat like the RCA-Siemens, so likely different construction, and perhaps, a different sound.


----------



## siles1991

I'm kind of short on cash was wondering if anyone was interested in Valvo E91H. Sylvania 5915 and Tung Sol 6AH6WA, I have one pair of each im trying to sell off, I live in Malaysia so if I could send them all to 1 person that would be great.


----------



## john57

siles1991 said:


> im kind of stumped with this is the Lepai TA2020 a DC coupled amplifier I was planning to pre amp out into this amp but I can't tell whether it is or not?


 
 It is most likely a AC coupled T amp and should be safe. There are other failures that can blow out speakers and a internal fault in the amp can still blow speakers. My LD VI+ is a direct coupled tube amp with DC servo control and so is my Schiit Lyr. A failure in the DC servo control could in theory blow out the headphones or speakers. I had a custom tube amp that was AC coupled (caps at the output) that took out a headphone when the tube arc over. DC coupled amps should have protection circuits in them for DC offset that can burn out speakers. There are pros and cons for direct coupled amps for both tube and Solid State.


----------



## KR500

The USAF 6AH6 sound really nice . I'll play them in a bit and post thoughts on them next week .
 CAT5E cable worked fine as a jumper . Used the orange and blue cable. Tubes are a bit tighter now
 The RCA 6DT6 are being sent back to the dealer , hum city although a tiny bit quieter in EF92 mode .  After 6 different pairs of preamp tubes these are the only faulty ones so far . The others are all completely noise free.
 I moved the Little Dot away from all electronic equipment with the RCA's just to make sure. but no change in the noise/hum .


----------



## TrollDragon

kr500 said:


> The USAF 6AH6 sound really nice . I'll play them in a bit and post thoughts on them next week .
> CAT5E cable worked fine as a jumper . Used the orange and blue cable. Tubes are a bit tighter now


Nice! 
It will be 2 weeks till mine arrive. I need a local tube supplier, strike that no I don't.


----------



## TrollDragon

john57 said:


> It is most likely a AC coupled T amp and should be safe. There are other failures that can blow out speakers and a internal fault in the amp can still blow speakers. My LD VI+ is a direct coupled tube amp with DC servo control and so is my Schiit Lyr. A failure in the DC servo control could in theory blow out the headphones or speakers. I had a custom tube amp that was AC coupled (caps at the output) that took out a headphone when the tube arc over. DC coupled amps should have protection circuits in them for DC offset that can burn out speakers. There are pros and cons for direct coupled amps for both tube and Solid State.


Many a failure can take things out quickly, but since the LD has no caps on the Pre-Amp Outs I still wouldn't take the chance of smoking someones $3K+ amp and speakers with a $300 inexpensive Chi-nee amp, whose manufacturer even states "You no hookup, no hookup" 

The Lepai 2020 is only $25 so I'd worry more about it taking out speakers, but that's another story...

I am still looking for a solution for the bretheren here.


----------



## TrollDragon

So I made a little stand to take pictures of tubes with...

  
 With the GE5654's

  


Spoiler: Then you plug it in and the Magic Happens!



 

  

  
 The light does not shine too well through the 6H30Pi-EH's, so I used both lamps...


----------



## mordy

Hi TrollDragon,
  
 Beautiful piece of work, but my tubes glow orange LOL...
  
 On a more serious note, there was a post way back of a guy who made a similar piece of wood for tubes, but instead of drilling the holes for the pins he made a circular grove the same size as the pin circumference (actually two sizes, one for 7 pin and one for 9 pin tubes).
  
 Then he put in fine sand in the grooves and twirled the tubes around. The picture he posted after this treatment showed sparkling clean pins. From what I have read a mechanical light scraping/cleaning gets you the best electrical metal to metal contact.


----------



## TrollDragon

mordy said:


> Hi TrollDragon,
> 
> Beautiful piece of work, but my tubes glow orange LOL...
> 
> ...


 
 Thanks mordy!
  
 Just had high intensity white LED's in the parts bin... 
  
 That is a great idea for the pin cleaner, I have another piece of hardwood, and the wife has some very fine grit for her rock polishing....
 Now to pick up the proper sized hole saws, 3/8" and 15/32" will do 7 and 9 pin respectively.


----------



## mordy

Hi TD,
  
 Thanks to the search function on this forum I found the original post. You may find this post useful: Post #639 by GermanGuy on this page:
  
  
  
 http://www.head-fi.org/t/632518/analog-paper-2-discussion-and-appreciation-thread/630#post_9573905
  
  
 Good luck!


----------



## TrollDragon

Thanks mordy!
I'll check it out for sure.
=====
Update from that info...

Before


After


I used a 3/4" dowel with a 7/16" hole drilled 1/2" deep, filled with 80 Mesh Lapidary Grit.
Stuck the tube pins in and rotated the dowel back and for for 1 minute or so, I know now why GG used the little disk of foam on the bottom of the tube. It kept the sand in his holder which I didn't have that problem of the grit falling out, but the grit will grind down the edge of the glass as well... 
I'll use a thin piece of foam next time I clean pins.

The Product & The Super Duper handmade Tooling.


I have 200 & 600 Grit as well but they are really fine, the 200 is a gritty powder and the 600 is like talcum powder, so I'll probably not use either of those.
I feel the 80 grit did a fine job cleaning the pins for a minute or two of easy turning.


----------



## mab1376

Just popped in my Mullard 10M Master series EBC91/6AV6 for the first time today, pretty impressive, lets see how time is to them.
  
 They came in fancy foam boxes with gold pins, I also have a set of RCA and Sylvania JAN 6AV6 i'm going to try later this week.
  
 I'm curious to how these compare to AFB Pinnacle 6AV6 as well if anyone has compared them.


----------



## mordy

Hi mab 1376,
  
 Found these inexpensive 6AV6 tubes of Japanese origin. They are NOT identical to the Pinnacle tubes, but have very similar construction including the unusual side getter. Have not tried them, but may be interesting to people who like the 6AV6 tubes.
  
  
 http://www.ebay.com/itm/2PCS-NEC-6AV6-Radio-Vacuum-tube-NOS-/151114821587?pt=Vintage_Electronics_R2&hash=item232f252fd3
  
  
 Please note that the price is per pair.


----------



## mab1376

This track is amazing with the Mullards mentioned above
  
 https://www.youtube.com/watch?v=Mh00MY_qycA


----------



## mordy

Congrats All! Today our thread  Little Dot Tube Amps: Vacuum Tube Rolling Guide - Page 190  
  
 surpassed the original thread in pages, and dare I say, in quality and overall usefulness
Little Dot MKIII Tube Rolling - Page 189


----------



## MIKELAP

mordy said:


> Congrats All! Today our thread  Little Dot Tube Amps: Vacuum Tube Rolling Guide - Page 190
> 
> surpassed the original thread in pages, and dare I say, in quality and overall usefulness
> Little Dot MKIII Tube Rolling - Page 189


 
  
 Thanks guys for bringing your knowledge to this thread whitout you i wouldnt have a dozen pairs of tubes that i didnt have a chance to listen to yet . I LOVE IT . Thanks.


----------



## TrollDragon

mordy said:


> Congrats All! Today our thread  Little Dot Tube Amps: Vacuum Tube Rolling Guide - Page 190
> 
> surpassed the original thread in pages, and dare I say, in quality and overall usefulness
> Little Dot MKIII Tube Rolling - Page 189


 
 Yes indeed!
 A serious wealth of information for those of us who are new to this game.
 It is very much appreciated. Thanks!


----------



## MIKELAP

Got my new Raytheon 6AN5 and i like the sound signature  well balance lush sounding nothing sticks out ,wide soundstage and depending on tune depth. i like them Will see if they evolve.This is with Senns HD800.


----------



## MIKELAP

You guys probably know Gary Clark jr. and his tune BRIGHT LIGHTs pretty good tune if you like guitar youll love this.


----------



## mordy

Hi TrollDragon,
  
 Interesting solution - one size fits all! This got me thinking: I don't have fancy woodworking tools, but how about this:
  
 I'll go to the playground and fill a plastic cup with sand from the sand box (hope the town doesn't mind). After cleaning the sand from dirt and debris (manually?) I'll take a little shot glass and fill it with sand. Then I'll take a thin piece cardboard or thick paper and push the pins through to be used as a shield.
  
 While holding the tube with the pins in the sand up to the shield I would turn the shot glass around for a minute or two. This should work.
  
 What do you think?


----------



## TrollDragon

mordy said:


> Hi TrollDragon,
> 
> Interesting solution - one size fits all! This got me thinking: I don't have fancy woodworking tools, but how about this:
> 
> ...


 
  
 Hey mordy!
 The shot glass might be a little bit too big and cumbersome to use in my humble opinion...
  
 I am using the top from a plastic food tub cut into a circle and holes poked through as the shield now.
 Do not use the tube to poke the holes, press the tube down hard to mark the plastic then with a scratch awl, big darn needle or any other sharp pointed thing poke the holes for the pins.
  
 Here is a cap from a bottle of nose spray that is a good size, but any small cap would do.

  
 Also here is a link to the carbide grit which i believe will cut better than sand, but by all means try the sand first a see how well it works.
 http://www.ebay.com/itm/Silicone-Carbide-80-Grit-Tumbling-Media-rock-tumbler-lapidary-supplies-1-pound-/231034625025
 (I don't know anything about that seller, he was the first search result that had a small amount available.)
  
 I am glad to see my little adaptation of GG's idea was useful here.


----------



## KR500

> It will be 2 weeks till mine arrive. I need a local tube supplier, strike that no I don't


 
 Last night I had a listening session with the new USAF 6AH6 6485 tubes and then my Mullard milspec CV4010 EF95's .
 Forgive me if some one already did this in one of the preceding 190 pages already.
 Phones are the new Audio Technica ATH-AD900X, source is Schitt Bifrost DAC and Tascam CD player 200.
 The USAF 6AH6's have a wider soundstage with more airey detail and are going back in for some more listening hours, the Mullards have a more round sound with more impact and bass.
 Also 4010 soundstage is a bit narrower than the 6485's... but still impressive, especially compared to the stock tubes or even JAN 5654's.
 The bass on the 6485's is noticeably leaner than bass on the CV4010's...... so, it can't do everything and may be a matter of matching  tube type sound to a particular headphone's characteristics as both are excellent.
 I would say at first glance it's almost a tie but the 4685's are intoxicating in their own way.
 Has anyone with the 900X's found they're own particular favorite driver tube combination with the LD yet ?


----------



## kvtaco17

With the ad900x I love the eh90 family... Rockin the ediswans currently.


----------



## MIKELAP

mikelap said:


> Got my new Raytheon 6AN5 and i like the sound signature  well balance lush sounding nothing sticks out ,wide soundstage and depending on tune depth. i like them Will see if they evolve.This is with Senns HD800.


 
  
 Also would like to add great bass more proeminent  more then other tubes i tried recently (6av6,6dt6a,)This is with the HD800 and my go to tune for testing.EDIT: WOULD LIKE TO SAY PREVIOUS COMMENT DOES NOT APPLY TO THESE TUBE MY EQ WAS ON AND MORE BASS WAS ADDED SORRY GUYS.


----------



## Acapella11

Fantastic Mordy, Thanks for the reminder.
  
 While I am waiting for a pair of 6DT6A, a brief update: My current tube of the month is the Raytheon 6BE6W with yellow label and black barrel as seen here.
  
 This guy may actually have more, it is not his first ad at ebay.
  
 It is just such an amazingly transparent tube, particularly in 1/7 enjoyable, which works actually really well and does not sound thin. Generous stage, focus, bass, treble, balance - all of a high grade. 2/7 is more defined and somewhat more forward, more a matter of taste than better or worse. I am listening to this tube now for a a couple of weeks and I can highly recommend it.


----------



## cubiboy90

I confused between MK III and MK IV, both of them look like the same and i don't know what to choose. Anyone can tell me any differences between them such as sound and tube-rolling(i love this part, it's fun
	

	
	
		
		

		
		
	


	




) ?


----------



## TrollDragon

cubiboy90 said:


> I confused between MK III and MK IV, both of them look like the same and i don't know what to choose. Anyone can tell me any differences between them such as sound and tube-rolling(i love this part, it's fun ) ?


Output power is the main difference as per the Little Dot Specs.

What headphones will you he connecting to the amp? Since they are OTL, they are designed to work very well with a high impedance headphone.


----------



## cubiboy90

trolldragon said:


> Output power is the main difference as per the Little Dot Specs.
> 
> What headphones will you he connecting to the amp? Since they are OTL, they are designed to work very well with a high impedance headphone.


 
  
 I'm using HE 400 & HD650 , Which one is the best choice ?


----------



## TrollDragon

cubiboy90 said:


> I'm using HE 400 & HD650 , Which one is the best choice ?


 
 The HD650 will work great with the III or IV and this user has a great deal on a IV SE version, send him a message and see if he still has it.
 http://www.head-fi.org/t/513275/the-little-dot-mk-iv-se-appreciation-thread/330#post_9773244
  
 The low Ohm orthos from what I have read require more power than the LD III or IV will put out.
  
 Recommendations for that headphone is a Schiit Lyr or the Woo WA6-SE as they both put out > 1Watt @ 32Ω where the LD III & IV only put out 100mW which IMHO would just barely drive it.
  
 You would probably be better of with an Audio-gd 15.32 3.5W @ 32Ω with 32bit / 384K DAC and they have a great deal on right now, no tubes but it will make the HE 400 sing.
 http://www.audio-gd.com/Pro/Headphoneamp/NFB15.32/NFB15.32EN_Specs.htm


----------



## cubiboy90

trolldragon said:


> The HD650 will work great with the III or IV and this user has a great deal on a IV SE version, send him a message and see if he still has it.
> http://www.head-fi.org/t/513275/the-little-dot-mk-iv-se-appreciation-thread/330#post_9773244
> 
> The low Ohm orthos from what I have read require more power than the LD III or IV will put out.
> ...


 
  
 Thanks for your help, i forgot about my impedance
	

	
	
		
		

		
			



, you really saved me.


----------



## gibosi

trolldragon said:


> The HD650 will work great with the III or IV and this user has a great deal on a IV SE version, send him a message and see if he still has it.
> http://www.head-fi.org/t/513275/the-little-dot-mk-iv-se-appreciation-thread/330#post_9773244
> 
> The low Ohm orthos from what I have read require more power than the LD III or IV will put out.


 
  
 cubiboy90....  Regarding HE orthos, you might want to get in touch with Audiofanboy as he currently uses the HE-500 with his LD IVse. Also, Acappella11 has a pair of HE 500s and a Little Dot MKIII. It might be worth your while to see what they have to say before making your decision.


----------



## gibosi

I have been busy creating a spreadsheet to help me to better keep track of my tubes. I am up to 311 so far and still have more to go.... I am pretty sure that several of you have even more, but I still think I have too many! Maybe I should have a garage sale? lol


----------



## siles1991

cubiboy90 said:


> I'm using HE 400 & HD650 , Which one is the best choice ?


 
  
 i'd say the little dot 1+ that is a hybrid tube amp that is meant for driving low impedance cans


----------



## Edgard Varese

A pair of GE 6DT6A tubes have arrived from Canada... though on the tubes they are marked as having been manufactured in Japan.  It's hard to see the glow with the way the grids are set up...


----------



## cubiboy90

gibosi said:


> I have been busy creating a spreadsheet to help me to better keep track of my tubes. I am up to 311 so far and still have more to go.... I am pretty sure that several of you have even more, but I still think I have too many! Maybe I should have a garage sale? lol


 
  
 That is too many, i think you'll need to open a tube store in future


----------



## Nic Rhodes

yes some of us a much worse on numbers


----------



## Edgard Varese

After a short warm up and just a couple of tunes I can hear exactly what you mean by the bass in the 6DT6As... awesome. 
	

	
	
		
		

		
		
	


	




  And I'm running them unstrapped in EF95 at the moment...


----------



## Audiofanboy

mordy said:


> Hi Acapella 11,
> 
> Some time back you asked me if I had evaluated different power tubes that I had planned to do. I finally gathered up the mental energy to check out four different types that I have, all from the Novosibirsk factory. Driver tubes were the RCA DTox tubes in 1/7 strapping.
> 
> ...


 
  
 Mordy asked me if I could possibly add my impressions of the two types of power tubes I've tested, and it made me realize that I had never formally reviewed them; at least not in a nicely structured way with pics. So here goes nothing.
  

  
 The Electro-Harmonix 6H30P-EB came stock on my MK IV SE. These are fine tubes: detailed, musical, balanced if slightly warm/colored; they make music sound very _alive_. You wouldn't notice anything is missing until you try a better tube really, and these complement the best but basic 6AK5 tubes very very well (the SE's stock tubes being these and the Mullard M8100 is no coincidence, it's an immediately satisfying mix).
  
 Still, it took me a while to figure it out, but these definitely lack absolute transparency and detail, smear transients a bit, and above all, they add a color to the sound and keep the amp from being neutral -or at least controlled by the driver tubes, which is should be. So, excellent and musical tubes, but not the best; and for $60, probably not "better" than the best of the 6N6P family. These are just not that good of a deal at that price point imho.
  

  
 The Reflektor factory 6N30P-DR are a totally different breed, even as an object. When you plug them in, you wouldn't notice an immediate and striking improvement but more of a "cold and neutral" signature (you can kind of picture Soviet workers making these in Siberia risking getting goulaged if they don't meet exact specs). So, at first, these definitely don't sound like $200+ power tubes; and there's no immediate "magic" -then again, power tubes are not supposed to sound magical, just neutral and transparent.
  
 But, after a couple dozen hours, you can start to tell. Music just _sounds right_ and better than you remembered: absolute transparency, realistic soundstage and detail retrieval (depends on your driver tubes, and the DR make finding good drivers difficult since they reveal faults very quickly), and as people have mentioned before, _authority_, absolute authority. Basically, after 100 hours with these, you can tell just how much of a bottleneck your previous power tubes were. The DR just remove that bottleneck entirely, and let you focus on driver tubes (a difficult search in and of itself).
  
 Now, I can't recommend them to anyone without a few caveats. To me, they take away one the amp's limits and allow it to be worth twice its price -figuratively and not figuratively- and that let's me roll driver tubes knowing that I'm hearing the most they have to offer because the power tubes are just doing their job right. Compared to the $60 Electro-Harmonix or even $40+ Sovtek 6H30P-EV, the DR are vastly superior and in a different league altogether imo. They sound like a different tube type.
  
 But compared to the best of best 6N6P, the 6N6P-IR, I'm not sure they're would be a seven-fold difference like the price would suggest. The 6N30 are most likely better than the 6N6, if just because they were made with even higher specs and are a stronger tube type in the first place (they were meant as an _evolution_ of 6N6P tubes), but as far as sound quality goes, the 6N6P-IR are probably just as neutral and not limiting as the DR. Just different tubes, with a different sound, but that remove an absolute limit the amp has. That absolute limit just might be higher with the DR.
  
 But, yeah, my choice of power tubes would still be between the best of the best Russians; and those would be the 6N6P-IR and 6N30P-DR, depending on budget and potential bottleneck concerns. I'd love to compare both, but I don't really wish to fork out another $40 to find out...


----------



## mab1376

I love my 6n6p-IR and unless someone can sell me DR tubes for >=$50 I personally see no need to upgrade.
  
 I have two pairs, one from '74 and one from'89. No immediate noticeable differences.
  
 I highly recommend them for power tubes! I am loving them with my Mullard 6AV6 10M master series tubes.
  
 As AFB said the The Electro-Harmonix 6H30P-EB are warm and musical, the IR tubes are detailed and transparent letting the gain tubes apply the flavor.


----------



## MIKELAP

mab1376 said:


> I love my 6n6p-IR and unless someone can sell me DR tubes for >=$50 I personally see no need to upgrade.
> 
> I have two pairs, one from '74 and one from'89. No immediate noticeable differences.
> 
> ...


 
  
 Expecting THE 6N6P IR tubes will see how they compare to the 6H30PI-EB with the Senns, only problem is the wait about 1 month to go.


----------



## mab1376

Hoe does the EB compare to the DR on paper?
  
 http://www.cryoset.com/catalog/product_info.php?products_id=287&osCsid=jue6pf0gvleh9p4rq5l35nnpf2


----------



## mordy

Hi mab 1376,
  
  
 The *5th element* in the tube designation is optional. It consists of a dash ("-") followed by a single character or a combination of characters, and denotes special characteristics (if any) of the tube:


*V* (Russian: *В*) - increased reliability and mechanical ruggedness (such as low susceptibility to noise and microphonics).
*R* (Russian: *Р*) - even better than V
*Ye* (Russian: *Е*) - extended service life.
*D* (Russian: *Д*) - exceptionally long service life.
*I* (Russian: *И*) - optimized for "pulsed" (i.e. switching) mode of operation.

 
EB/EV means extended service life (5000 hours) and increased reliability and ruggedness
IR means pulse mode operation and highest level of reliability and ruggedness


----------



## mordy

http://www.cryoset.com/catalog/product_info.php?products_id=287&osCsid=jue6pf0gvleh9p4rq5l35nnpf2
  
 This link takes you to cryogenically treated tubes that have been subject to - 300 degrees Fahrenheit. Based on what I have read, freezing tubes at these temperatures have no benefits, and is a marketing gimmick.
  
 Does anybody have experience with this?


----------



## mab1376

I think its BS, is was more for the tube image.


----------



## mordy

Hi All,
  
 Just found an answer to a question I had for a long time: Why do some tubes have little colored splashes on top of the nib? In the past I had Western Electric tubes with red on the nib, and these Sylvanias below have a blue color on the nibs. Why? (Answer below)
  
  





 " Tiny drips of paint on tube tops meant the tubes passed extra quality control tests. For preamp tubes this meant best for microphonics".
  
 Now, all that's left to know is how to decipher the date codes on the Tung Sol tubes...lol


----------



## Oskari

mordy said:


> " Tiny drips of paint on tube tops meant the tubes passed extra quality control tests. For preamp tubes this meant best for microphonics".


 
  
 Or perhaps some other test criteria depending on application. Unless the painter was just some less than scrupulous profiteer. I'm a little bit skeptical because paint is very easy to apply.
  


> Now, all that's left to know is how to decipher the date codes on the Tung Sol tubes...lol


 
  
 And Sylvania.


----------



## Oskari

audiofanboy said:


> a totally different breed, even as an object.


 
  





  They look pretty much the same and were made in the same factory.


----------



## zedmeco

http://lampizator.eu/UPGRADE/upgrade%20noval%20tubes%20to%206H6P.html
 Hi can someone with more knowledge then me have a look at this article, he seems to imply the 6n1p can be a direct replacement for the 6n6p, and that it sounds better! can this be right. 
  
 a massive sorry to the regulars that messaged me about the seimens tubes, i haven't logged on for ages! i still have them but they hum in my mk3 and you all seem to rate them. i have two pairs, i will take some pictures and post them for your perusal. thanks Z


----------



## mordy

Hi Oskari,
  
 Here is a little information on Sylvania (if it is repetitious I apologize). _At the end of this post I have put in my 2 cents worth of personal opinion on Sylvania date codes:_
  
 "What does J.H.S. and J.A.N. mean?

 Sylvania was a major manufacturer of Military tubes and selected a 3 digit lettering system to designate Sylvania products. One system prefixes a three-digit number with the letters "VT", presumably meaning "Vacuum Tube". Other systems prefix the number with the letters JHS or JAN. J.A.N. is believed to stand for Joint Army Navy, where as, J.H.S. sometimes remains a mystery, and is commonly thought to just signify Sylvania product.

 The numbers following these prefixes can be special four-digit numbers, or domestic two- or three- digit numbers or simply the domestic North American RETMA numbering system. Like the British military system, these have many direct equivalents in the civilian types. Confusingly, the British also had two entirely different VT nomenclatures, one used by the Royal Air Force and the other used by the General Post Office, responsible for post and telecommunications at the time, where it may have stood for Valve, Telephone; none of these schemes corresponded in any way with each other. It was introduced during the Second World War to rationalize the previous nomenclatures maintained separately by the War Office/Ministry of Supply, Admiralty and Air Ministry/Ministry of Aircraft Production on behalf of the three armed services for CRTs, receiving and transmitting valves used in army equipments.

 I personally have researched this in the past, and have come up with the theory that JHS was chosen by Sylvania meaning Joint Havells Sylvania or J.H.S.

 Havells Sylvania is an international designer and manufacturer of lighting products. It has plants throughout Europe, Asia, North Africa and Central and South America, and is one of the few lighting companies that produces both lamps and lighting fixtures. It is owned by Havells.Founded in the early 1900s as a business that renewed burned-out light bulbs, Sylvania and its predecessor companies ultimately began producing new lamps and then vacuum tubes for the radio industry.

 Mark Kawecki
 tubemuseum
  





 MEANINGLESS CODES by TUBE REMARKETERS:

 Both Tung-Sol and RCA utilized the "Stop-Sign" logo [5751] in brackets. The "hole" in the top mica identifies these USA made tubes from the TUNG-SOL factory in Newark, New Jersey, USA in the 1950's.

 THE UNITED-ELECTRIC RELABEL CODE 88-37 IS MEANINGLESS AS THEY SIMPLY RELABELED NEW OLD STOCK TUBES FROM TUNG-SOL. RCA, SYLVANIA, AND OTHERS. NO ONE MADE D-GETTER OR SQUARE-GETTER TUBES IN 1988! AND UNITED-ELECTRONICS WAS OUT OF BUSINESS IN 1988! SO 88-37 WAS UNITED-ELECTRONICS INTERNAL NUMBERING SYSTEM AND DID NOT SIGNIFY ANY MANUFACTURING DATE.

 Especially, during the 1950's war effort, it was a common practice for USA factories to source tubes from each other and re-label them. When a government requirement for CV4017 tube specification came in a Request For Proposal (RFP) to the 4 major USA tube factories they all worked together to source from one another to fill the orders. This is why we see so many tubes made by Tung-Sol labeled as RCA, RCA made tubes labeled Sylvania, Sylvania made tubes labeled GE ... and so on, Sylvania, RCA, Tung-Sol and everyone else at some time relabeled tubes! This is why we have to LOOK AT THE ORIGINAL FACTORY CODES IF PRESENT (NOT THE UNITED ELECTRONICS RELABEL CODE),, and identify the real tube manufacturer by codes, inner construction, shape of the tip, and shape of the getter ring to determine the real origin of the tubes.

 UNITED (United Electrics Company, Newark, N.J., USA) was a company that simply re-labeled Tung-Sol, RCA, Sylvania, and GE USA made tubes for resale.

 
 All tubes have Tung-Sol acid codes shown as in above picture on top and Made in USA in 1960. In the actual pair above you can see "60 - 40" code = "1960 - 40th week" and "60 - 33" code = "1960 - 33rd week" TUNG-SOL USA

 Made in USA in 1964. In the actual pair you can see "64 - 02" code = "1964 - 2nd week" and "65 - 20" code = "1965 - 20th week" TUNG-SOL USA"




  
 In my personal notes I have a notation that a Sylvania tube coded L7V was manufactured in December 1957/67 in plant V, but I don't remember my source for this. Anyhow, the months would go in order of the alphabet; A=January, B= February and so on until L =December.
 The digit 7 would indicate the year, 1957 or 1967. The last letter would be a code for a plant, in this case plant V.
  
 Stuck my fingers into my 6AK5 box and fished out a couple of Sylvania tubes. Two tubes are coded GB and GH. ???
 The next one says H1. Maybe August 1951/61.
 The next tube has a yellow nib and says F2E. Maybe June 1952/62 plant E.
 Next is H0E. What do u say? August 1950/60 plant E.
 Next is E1E: May 1951/61 plant E.
 Next B2E: February 1952/62 plant E.
 All of them have square getters and look pretty old, so maybe the 1950's.
  
 I am getting a headache, but maybe we have some kind of pattern here?
  
 PS: About the colored nibs, the pair of  Western Electric tubes with the red paint came from boxes that indicated that they were made for the Sperry Rand Corporation on Long Island, NY, which produced gyroscopes for military use.


----------



## Audiofanboy

oskari said:


> They look pretty much the same and were made in the same factory.


 
  
 They may look similar, but they are different tubes made with different alloys, tooling and parts. Mojorisin had made a very nice post about how to recognize a DR from an new production tube:
  
 http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/1425#post_9480971
  
 Having had both in my hands, I can say that they do not give off the same feel; the DRs feel like you could throw them against a wall and they would fine lol. They sound surprisingly different though, moreso than I would have thought for tubes made in the same factory.


----------



## Oskari

zedmeco said:


> http://lampizator.eu/UPGRADE/upgrade%20noval%20tubes%20to%206H6P.html
> Hi can someone with more knowledge then me have a look at this article, he seems to imply the 6n1p can be a direct replacement for the 6n6p, and that it sounds better! can this be right.


 
  
 I see no such implication there.


----------



## Iron58p

I'm burning GE JG-5750 6BE6W, setting EF92, year 1958
  
 Are fantastic tubes on my opinion, medium hights transparent, clear and very detailed, bass fast and not invasive on medium, female voices very nice, soundstage the best unltil now,  on corus is possible closing the eyes to collocate the position of each singer on the scene.
  
 Uaww, make me dream !!


----------



## Audiofanboy

edgard varese said:


> A pair of GE 6DT6A tubes have arrived from Canada... though on the tubes they are marked as having been manufactured in Japan.  It's hard to see the glow with the way the grids are set up...


 
  
  


edgard varese said:


> After a short warm up and just a couple of tunes I can hear exactly what you mean by the bass in the 6DT6As... awesome.
> 
> 
> 
> ...


 
  
 Those tubes you mention are CGE 6DT6A Japan "made to CGE specifications" right? I just got the same tubes in the mail, and threw them on the amp for a thorough burn-in; so I'm interested in your experience with them!
  
 First impressions are favorable; indeed the bass roars with these! Too many of the recent tubes I tried either smeared mid-bass and bass or just left it out of the picture entirely.
  
 EF92'd, these 6DT6A are very nice out of the box: surprisingly musical and toe-tapping from the start, delicious and pretty tactile bass, very nice mids that beautify voices. Hopefully they'll stay that way after 20 hours, and just tighten up. Still, finally having a bit of low-mids and bass is a nice change!
  
 Why EF92 setting you say? (Please don't hit me lol) Because it's what sounded the best on the GE Canada-made 6DT6A I tried, for one. And also because it is one the two solutions that intuitively make sense with this tube type. I see no reason to float grid 3 with these tubes, so plain EF95 is bleh. Strapping the two control grids together (1-7) is OK but the tube doesn't require it to work well, so meh, but it's worth a try. Now, Strapping the suppressor/2nd control grid (grid 3) to the cathode (2-7) is pretty logical, but grid 3 on these tubes is pretty weird and like a tightly woven suppressor, so I don't know how it behaves 2-7'd with grid 2 strapped to the anode; but it makes sense. Finally, Strapping grid 3 to the anode and grid 2 (EF92) makes sense since you get a textbook triode-strapped pentode -dual control or not, whatever. That setting sounds the best to me so far.
  
 Yeah, call me too scholar or Manichean if you want, and there's no harm in testing things, but some settings just don't make much sense... Floating grid 3 on a pentode is just kind of purposeless imho...


----------



## Oskari

mordy said:


> "What does J.H.S. and J.A.N. mean?
> 
> Sylvania was a major manufacturer of Military tubes and selected a 3 digit lettering system to designate Sylvania products. One system prefixes a three-digit number with the letters "VT", presumably meaning "Vacuum Tube". Other systems prefix the number with the letters JHS or JAN. J.A.N. is believed to stand for Joint Army Navy, where as, J.H.S. sometimes remains a mystery, and is commonly thought to just signify Sylvania product.
> 
> ...


 
  
 Mark's research is weak. The "systems" were military and hardly "selected" by Sylvania. Havells Sylvania is a recent creation, so that theory is bollocks. I believe JHS is just a contraction of JAN-CHS where CHS indicates Sylvania (or Hygrade Sylvania as it was previously known as).


----------



## Oskari

mordy said:


> PS: About the colored nibs, the pair of  Western Electric tubes with the red paint came from boxes that indicated that they were made for the Sperry Rand Corporation on Long Island, NY, which produced gyroscopes for military use.


 
  
 In which case it is entirely plausible that there was a rigorous selection process.


----------



## Oskari

mordy said:


> Stuck my fingers into my 6AK5 box and fished out a couple of Sylvania tubes. Two tubes are coded GB and GH. ???


 
  
 It's these two-letter and three-letter (no digits) Sylvania codes that I've seen no explanations of. Sometimes you see both of them together.
  


> The next one says H1. Maybe August 1951/61.
> The next tube has a yellow nib and says F2E. Maybe June 1952/62 plant E.
> Next is H0E. What do u say? August 1950/60 plant E.
> Next is E1E: May 1951/61 plant E.
> ...


 
  
 I agree that the digit is probably the last digit of the year. Have you got any to double-check like with a date on the box?


----------



## zedmeco

oskari said:


> I see no such implication there.


 6N1P

The beauty of this tube is that is pin-compatible with not only 6N6P, but also with ECC 88, E88cc, 6DJ8, and 6922 popular tubes. The sound of 6N1 is more crisp and energetic than the sound of 6N6P and it is more easy and natural than that of the ECC 88, E88cc, 6DJ8, and 6922.


----------



## Oskari

"Usually - in amplifiers - I would use 6N1P as input amplifier and the 6N6P as driver (high current !!!)"


----------



## mab1376

Dunno if anyone else had this issue, but I broke 2 6AV6 tubes so far cutting pins. The base cracked one one of my RCA and one of my Sylvania.


----------



## MIKELAP

Was trying to find a way to clean the pins first i tried with a plastic  pill  container took and old tube heated it up and press the tube against the plastic lid and the heated steel pins poked thru the thin plastic lid and on a large container i could clean up to 4 tubes at a time the problem is finding the right material to clean the pins efficiently i used regular sand and a fast moving rock and roll tune to help me along but doesnt do a good job would have to try that silicon carbide Troll Dragon was talking about but what i found and works very good is a rubber coated tapered bit it goes everywhere and removes all the dirt ,does a great job but doesnt last foreever compared to a sandlike substrate.


----------



## gibosi

mab1376 said:


> Dunno if anyone else had this issue, but I broke 2 6AV6 tubes so far cutting pins. The base cracked one one of my RCA and one of my Sylvania.


 
  
 I have cut probably 15 pairs so far and never had this happen....  Perhaps your cutters are a bit dull?


----------



## MIKELAP

mab1376 said:


> Dunno if anyone else had this issue, but I broke 2 6AV6 tubes so far cutting pins. The base cracked one one of my RCA and one of my Sylvania.


 
  
 I broke a 6j4s cutting the pins the pin next to the one i was cutting broke off it was bent a little brought it back as i to with all bent pins but this time it broke crap thats one pair i wont be trying. Ya Super its your pair. might as well show you a picture of those nice looking tubes wont see them again. First time i broke one also and it had to be those was looking forward to listening to those tubes


----------



## mab1376

gibosi said:


> I have cut probably 15 pairs so far and never had this happen....  Perhaps your cutters are a bit dull?


 
  
 They're brand new blue point lead snippers. They're ridiculously sharp. I had no issue on gold pins.
  
 Luckily it only happened to one of my 3 RCA tubes, but I only had 2 sylvanias so i no longer own a pair.
  
 I also covered the pin with a cloth so it wouldn't go flying away, maybe that caused it to resonate the impact into the glass?


----------



## gibosi

mab1376 said:


> They're brand new blue point lead snippers. They're ridiculously sharp. I had no issue on gold pins.
> 
> Luckily it only happened to one of my 3 RCA tubes, but I only had 2 sylvanias so i no longer own a pair.
> 
> I also covered the pin with a cloth so it wouldn't go flying away, maybe that caused it to resonate the impact into the glass?


 
  
 I can't imagine that covering the pin with a cloth would cause this.... Perhaps cutting the pin aggravated a pre-existing small internal stress fracture in the glass....
  
 Going forward, I guess we should just assume that there is always a chance this will happen. And I have just been very lucky so far.


----------



## TrollDragon

The dremel with a small cutoff disk should snick those pins off rather quickly and without much stress. Dremel's can get away from you really quickly though if you are not careful.


----------



## TrollDragon

@MIKELAP What dremel speed did you run the rubber tip at to clean up the pins? I can see that going wrong quickly with bent pins everywhere...

I shall have to try this method as well, even though the carbide does work satisfactory.


----------



## MIKELAP

trolldragon said:


> @MIKELAP What dremel speed did you run the rubber tip at to clean up the pins? I can see that going wrong quickly with bent pins everywhere...
> 
> I shall have to try this method as well, even though the carbide does work satisfactory.


 
Maximum speed and  its pretty safe of course if your not confortable with Dremel's dont try it. 

  
Heres a picture of the two, bit is pretty small


----------



## zedmeco

thanks for clearing this up for me.


----------



## TrollDragon

Thanks MIKELAP!
Is that a Dremel brand bit or a Princess Auto / Canadian Tire version? I might just have to stop in at PA on the way home...


----------



## mordy

TALES FROM THE SAND BOX OR THE BEST WAY TO CLEAN TUBE PINS
  
 Decided to do an experiment on cleaning tube pins with available means, i.e. no cost involved. First I snuck out to the local playground and scooped up half a plastic cup of playground sand. The big stuff in the cup are pieces of wood mulch.
  
  

  

 After manual cleaning of the sand, some of it was poured into a shot glass:

 A pin shield was made out of an old CD mailer. The holes were made pressing the tube against the paper, then marking the indentations and piercing with a small awl. (Will Amazon pay me royalties?)

 Selected two corroded tubes from my 6AK5 collection. The tube with the blue bottom plate is a Crosley (RCA) from January 1952 and the clear bottom plate is a Tung Sol from January 1954. This is the BEFORE picture:

  
 The plan was to use a rubber finger grip and turn the Crosley tube inside the sand of the shot glass for one minute in each direction. The second part of the experiment was to use an alternative cleaning method as a comparison of effectiveness - more later.


  
 This is a picture of a rare cactus. No, it's not a Barrel Cactus, but a Yellow Nib Tube Cactus (_Croslesia Audiophilia Nervosa_)

 Here is an action shot of tube turning using the pin shield (finger grip removed for clarity)

 The alternative method of pin cleaning has been exhaustively described in the literature as scraping the pins with something somewhat sharp. What could be more appropriate than a historically correct 1950's pocket knife?


 Wait, what's that inscription on the bottom of the blade?

 Well, having squinted over countless tubes trying to read invisible markings, this is a piece of cake: It reads: Colonial. Prov USA 492. Obviously, (with a little help of our Google friends) this knife was manufactured by the Colonial Knife Co of Providence, Rhode Island, USA the second week of 1949. (Actually, since this is not an EIA tube, maybe 492 is a model number? )
  
 In the interest of scientific exploration, we continue: The blue bottom tube was cleaned with the shot glass method, and the clear bottom tube with the pocket knife: This is the AFTER picture:


 Looking at the picture, neither tube is sparkling clean. Looking at the before picture (4th picture) there is a definitive improvement; maybe the Crosley cleaned with sand is a little cleaner. However, the sand thing is cumbersome and tedious; the scraping is much faster and easier. What really counts is the electrical contact. If the scraping does not help the first time, I can always look for spots and do a little more.
  
 Verdict: Colonial wins


----------



## MIKELAP

trolldragon said:


> Thanks MIKELAP!
> Is that a Dremel brand bit or a Princess Auto / Canadian Tire version? I might just have to stop in at PA on the way home...


 
 Got that set at Canadian Tire a few years ago the set was on special at 1/2 price ($15.00 or so )so i bought 3 sets like this always useful .


----------



## Acapella11

Music post
  
 If you like sophisticated nature sounds and are willing to pay for them, check this out:
  
 http://www.naturespace.com/
  
 The page is also interesting because it explains theories of sound space, psycho acoustics and holographic sound.


----------



## TrollDragon

mikelap said:


> Got that set at Canadian Tire a few years ago the set was on special at 1/2 price ($15.00 or so )so i bought 3 sets like this always useful .


 
 Thanks!
 Will be seeking me out one of those or similar when on sale, I picked up the Mastercraft 500 piece set in the wooden box quite a while back for $19.99, now that I think of it there might be one in there... Oh well still need to stop at Princess Auto (Harbour Freight for you US peeps) on the way home to see just what is there in dremel bits.


----------



## mab1376

gibosi said:


> I can't imagine that covering the pin with a cloth would cause this.... Perhaps cutting the pin aggravated a pre-existing small internal stress fracture in the glass....
> 
> Going forward, I guess we should just assume that there is always a chance this will happen. And I have just been very lucky so far.


 
  
 First few I did I used my finger to cover it from flying away and it had so much force it actually hurt a bit, so I used just a piece of my shirt in between the pin and my finger.


----------



## MIKELAP

acapella11 said:


> Music post
> 
> If you like sophisticated nature sounds and are willing to pay for them, check this out:
> 
> ...


 
  
 That site is neet you have free download also. Home page lower right under DEMOS


----------



## Edgard Varese

audiofanboy said:


> Those tubes you mention are CGE 6DT6A Japan "made to CGE specifications" right? I just got the same tubes in the mail, and threw them on the amp for a thorough burn-in; so I'm interested in your experience with them!
> 
> First impressions are favorable; indeed the bass roars with these! Too many of the recent tubes I tried either smeared mid-bass and bass or just left it out of the picture entirely.
> 
> ...


 
  
  
  
 Yes, that's right, "CGE 6DT6A Japan".  I'll have to check them out on the EF92 setting as you suggest.  I only had a few minutes of listening last night (on EF95) but these are pretty much my favorite tubes at the moment.  They managed to recreate the "wow" factor that I experienced when I first got the Little Dot.


----------



## Audiofanboy

edgard varese said:


> Yes, that's right, "CGE 6DT6A Japan".  I'll have to check them out on the EF92 setting as you suggest.  I only had a few minutes of listening last night (on EF95) but these are pretty much my favorite tubes at the moment.  They managed to recreate the "wow" factor that I experienced when I first got the Little Dot.


 
  
 Interestingly, when I tried them EF95'd, the tubes started humming in a ground-loop like fashion (the first tube after 30s, the second one after 37s), meaning that the floating grid 3 was doing something _out of the ordinary_... I definitely cannot recommend floating g3 on pentodes...
  
 Fine tubes though, those Japanese 6DT6A tube are, I reckon. Didn't get a chance to spend that much time with them yet but they do have a "wow" factor.


----------



## Edgard Varese

audiofanboy said:


> Interestingly, when I tried them EF95'd, the tubes started humming in a ground-loop like fashion (the first tube after 30s, the second one after 37s), meaning that the floating grid 3 was doing something _out of the ordinary_... I definitely cannot recommend floating g3 on pentodes...
> 
> Fine tubes though, those Japanese 6DT6A tube are, I reckon. Didn't get a chance to spend that much time with them yet but they do have a "wow" factor.


 
  
  
 Interesting... no hum at all with mine.  They are silent and run quite cool (on LD I+).


----------



## zedmeco

zedmeco said:


> http://lampizator.eu/UPGRADE/upgrade%20noval%20tubes%20to%206H6P.html
> Hi can someone with more knowledge then me have a look at this article, he seems to imply the 6n1p can be a direct replacement for the 6n6p, and that it sounds better! can this be right.
> 
> a massive sorry to the regulars that messaged me about the seimens tubes, i haven't logged on for ages! i still have them but they hum in my mk3 and you all seem to rate them. i have two pairs, i will take some pictures and post them for your perusal. thanks Z


As promised here are the pics, they still hum in my amp! 
	

	
	
		
		

		
			





[/IMG][/IMG][/IMG][/IMG][/IMG][/IMG][/IMG]


----------



## Edgard Varese

The tubes continue to fly into the house... in today are a pair of IBM 6BE6 (1680).  My first heptodes!


----------



## peterlily

good info,get optimum performance only when raising the bar to 65-70% (one o'clock). I can stand this volume level for a whole day.


----------



## mab1376

One of my Raytheon 6DT6A tubes is way brighter and hotter than the other, anyone else experience this?


----------



## jjsoviet

Can anyone identify this tube?
  
 Forgot that I had this as a bonus when I bought the Voshkod.
  

  
  
  
 It's spelled 6ж3п-e or something.


----------



## gibosi

jjsoviet said:


> Can anyone identify this tube?


 
  
 This appears to be a 6J3P-E (EF96 or 6AG5).


----------



## jjsoviet

gibosi said:


> This appears to be a 6J3P-E (EF96 or 6AG5).


 
  
 Thanks! It looks like it.


----------



## mordy

Hi mab 1376,
  
 I have noticed that some of the 6DT6 tubes run hotter than others, both as pairs among different brands, and as individual tubes from the same brand. As a rule, after the initial burning in period the tube runs cooler. IMHO it does not not matter if one tube feels hotter than the other, as long long as there is no sonic difference.
  
 Same thing about one tube glowing stronger than the other. Usually it is a function of how the internal parts were put together, and in one tube it may be more difficult to see the heater than in another. Unless the sound is effected, it does not matter.
  
 How do you like the Raytheon 6DT6A tubes? The ones I have are made in Japan by Hitachi and sound best on the 2/7 strap setting. They also sound good unstrapped.


----------



## mab1376

mordy said:


> Hi mab 1376,
> 
> I have noticed that some of the 6DT6 tubes run hotter than others, both as pairs among different brands, and as individual tubes from the same brand. As a rule, after the initial burning in period the tube runs cooler. IMHO it does not not matter if one tube feels hotter than the other, as long long as there is no sonic difference.
> 
> ...


 
  
 I only have a few minutes on them, not enough for a real impression yet, i was using them in EF92 settings.


----------



## Edgard Varese

mab1376 said:


> One of my Raytheon 6DT6A tubes is way brighter and hotter than the other, anyone else experience this?


 
  
  
 I have a pair of GE 5654s where one is considerably brighter than the other, but there is no channel imbalance.


----------



## mab1376

mordy said:


> Hi mab 1376,
> 
> I have noticed that some of the 6DT6 tubes run hotter than others, both as pairs among different brands, and as individual tubes from the same brand. As a rule, after the initial burning in period the tube runs cooler. IMHO it does not not matter if one tube feels hotter than the other, as long long as there is no sonic difference.
> 
> ...


 
  
 They are the Japan tubes, i'll try on 2-7 when i swap back to EF95, trying out my 6AV6 currently.


----------



## TrollDragon

I have 4 of the Japan CGE 6DT6's inbound and a pair of those NEC 6AV6's as well. Still waiting on the USAF's, hopefully this week along with my new headphone jack.


----------



## MIKELAP

Listening to some Admiral 6DT6A tubes on EF92 and  EF95  seems cleaner sounding on EF92 setting. by the way you are strapping EF-95 1-7 which setting is  the 2-7 for ?


----------



## gibosi

This week, I found a couple small packages in my mailbox:
  
 A pair of Raytheon 6EB6W - (no dates on the tubes or the box)
  

  
 Based on Acappella11's recommendation, I purchased these Raytheon 6BE6W. While I have managed to burn them in, I haven't really had time to do any critical listening and comparing.  As my headphones are not as bright as A11's, I find that the more forward sound of 2/7 is best for me. They are very transparent, somewhat warm, with nice "heptody" highs and some of the best bass I have heard out of a heptode. Very nice.
  
 And a pair of Canada General Electric JLRV 6AT6 (1965)
  

  
 Appearance wise, these are very different than any GE 6AT6/6AV6 tubes I have seen to date. However, these tubes do look almost identical to Audiofanboy's *Pinnacle 6AV6*.
  
 AFB has compared pictures of these CGEs to his Pinnacles and he tells me that the glass envelope as well as the innards - micas, plates, diodes - look virtually identical. Further, while these have been cooking for less than two hours, they appear to have a very high level of clarity and transparency, mids that are more wet and musical than most 6AT6/6AV6, and *BASS!* which correlates well with AFB's Pinnacles. I think it is quite likely that his Pinnacles and these CGE were manufactured in the same factory. But if so, where that factory might have been located is still a mystery. If they really were manufactured in Canada, who manufactured them? Might these too be Japanese imports?


----------



## mordy

Hi Gibosi and AFB,
  
 What do you say about the right tube in this picture? It is a Raytheon made in USA.
  





 The plot thickens...


----------



## gibosi

Interestingly, the left-hand tube appears to be a rebadged RCA.
  
 And here you see something similar from Raytheon: A rebadged RCA on the right and a tube that seems to to resemble the CGE/Pinnacle on the left. However it is not clear that these mystery tubes were actually manufactured in the US. It may well be that Raytheon acquired them elsewhere and simply relabeled them......


----------



## Oskari

gibosi said:


> And a pair of Canada General Electric JLRV 6AT6 (1965) ... Appearance wise, these are very different than any GE 6AT6/6AV6 tubes I have seen to date. However, these tubes do look almost identical to Audiofanboy's *Pinnacle 6AV6*. ... If they really were manufactured in Canada, who manufactured them?


 
  
 They do look the same! Radio Valve Co. of Canada.
  

http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/795#post_9222915


----------



## Audiofanboy

I can confirm that they look exactly the same as my Pinnacle tubes. Mystery may be solved...?


----------



## Iron58p

Today are arrived 7 couples of tube, all in the same day 
	

	
	
		
		

		
		
	


	



  
 Voskhod 6J1P-EV (EF95 6F32 6AK7) Gold-Platinum grid ( matched ) year 1982 ----------(EF95)        One channel has a noise, i hope that finished burn in, noise will desappear.
  
 Siemens 6AK5W (M8100, CV4010,5654) ------------   (EF95)
  
 RCA JAN 6AV6--------------(EF92 and cut pins 5 and 6)
  
 GE JAN 6AV6------------- (EF92 and cut pins 5 and 6)
  
 SYLVANIA 6BE6 (EK90, CV4012, 5750)------------- (EF95)
  
 For all tubes in this post, without strapping !!
  
  
  
  
 About the 2 couples below, i don't know anything, for example if i can use it without strapping or cut pins ( for the moment i'm not ready to strap )
  
 GE 8425A (6AU6A)------------(EF95)
  
 Tung-Sol JTL 6AH6WA (6J5P, 6485)------------(EF95)
  
 Is all correct ?
  
 Thank's


----------



## gibosi

iron58p said:


> Today are arrived 7 couples of tube, all in the same day
> 
> 
> 
> ...


----------



## Iron58p

All clear, thank's.
  
 Any kind of metal is ok ? i now that must be thin.... an electric cable with copper inside is ok ( isolated in the middle ) ?


----------



## gibosi

Canadian GE 6AT6 (and Pinnacle 6AV6)
  
 After spending some time with these tubes, it is my opinion that these are essentially RCA 6AT6/6AV6. With the exception of the diode plates, they are virtually identical. Moreover, they sound virtually the same.
  
 It is a little funny that the diode plates are the most noticeable feature of this family of tubes and we tend to focus on this feature when physically comparing them. But of course, the diode and triode circuits are entirely different and separate, and moreover, by cutting pins 5 and 6, we effectively disable the diode. So while the diodes in these two tubes are slightly different, the glass envelope, the micas, the triode plates and the getters are virtually the same. And thus, I believe these are simply black-plate RCAs.


----------



## gibosi

iron58p said:


> All clear, thank's.
> 
> Any kind of metal is ok ? i now that must be thin.... an electric cable with copper inside is ok ( isolated in the middle ) ?


 
  
 Yes, stranded cable, smaller than 26 gauge, equivalent to (.04mm and .134mm2)


----------



## Oskari

gibosi said:


> But if so, where that factory might have been located is still a mystery.


 
  
 BTW, this seems to have been the location of RVC on Dufferin Street in Toronto. 
	

	
	
		
		

		
		
	


	



  

http://wikimapia.org/#lang=en&lat=43.636735&lon=-79.426056&z=17&m=b


----------



## kvtaco17

Got a pair of OPA627's yesterday... very similar to the TI OPA2107, but with much improved channel separation, slightly bigger sound stage, better instrument separation... so far  it sounds kinda like a hybrid love child of the OPA2107 and LME49990... I like it a lot!
  
  
 I also received the GE 6DT6 (grey plates and ribbed) Svetlana 6A2P (looks a lot different in construction vs other heptodes I've deal with) AND a new to me AD2000X (amazing cans I must say!)
  

 GE 6DT6
  

 Sylvania, RCA, GE 6DT6 comparison
  

 More of the same...
  

 Svetlana 6A2P
  

 Svetlana with its Ediswan and Valvo cousins...
  

 OPA2107 and OPA627
  

 OPA627 installed!


----------



## mab1376

kvtaco17 said:


> Got a pair of OPA627's yesterday... very similiar to the TI OPA2107, but withe much improved channel seperation, slightly bigger soundstage, better insturment seperation... so far  it sounds kinda like a hybrid love child of the OPA2107 and LME49990... I like it a lot!
> 
> 
> I also receieved the GE 6DT6 (grey plates and ribbed) Svetlana 6A2P (looks a lot different in construction vs other heptodes I've deal with) AND a new to me AD2000X (amazing cans I must say!)


 
  
 You should try the OPA1611 and the LME49720 also, Also i very much like the warmness of the AD797.
  
 These are all from my SS iBasso amp though.


----------



## kvtaco17

mab1376 said:


> You should try the OPA1611 and the LME49720 also, Also i very much like the warmness of the AD797.
> 
> These are all from my SS iBasso amp though.


 
 I will get around to it eventually, I really like the Burr Brown/TI sound it seems... So for now I will enjoy what I have lol


----------



## mordy

From what I am reading, it appears the the mysteries of two mystery tubes have been solved:
  
 1) Siemens "Foreign" seems to be a Japanese Matshushiita/(Hitachi ?) tube, also available as Haltron 6CS6. (Paid $2 for a pair, but got hit with $8.50 shipping from Canada). Under what other brand names and designations is this tube available? Zaerix?
  
 2) Pinnacle 6AV6 seems to be a RCA black plate rebranded side getter tube. What is the difference between the side getter 6AV6 and 6AT6 if any? What about 6AQ6, which looks different than the 6AT6/6AV6, although I saw a Westinghouse 6AQ6 that looked like a side getter tube as well? Under what other brand names and designations is this tube available? CGE?, NEC?, Raytheon?
 Seems that the 6AV6 and 6AT6 is available as a top getter from the same brands that made the side getter tube. Is there a difference in sound?
  
 Would appreciate your help with the above.


----------



## gibosi

mordy said:


> From what I am reading, it appears the the mysteries of two mystery tubes have been solved:
> 
> 1) Siemens "Foreign" seems to be a Japanese Matshushiita/(Hitachi ?) tube, also available as Haltron 6CS6. (Paid $2 for a pair, but got hit with $8.50 shipping from Canada). Under what other brand names and designations is this tube available? Zaerix?
> 
> ...


 
  
 1) Yes, this tube has been marketed under the Zaeix label. However, as Zaerix was a rebrander, one cannot assume that all Zaerix EH90/6CS6 are equal to the Siemens "Foreign".
  
 2) The 6AQ6 has .15 amp heaters and a gain of 70. The 6AT6 has .3 amp heaters and a gain of 70. And the 6AV6 has .3 amp heaters and a gain of 100. In my experience, at least with Sylvania, these three sound essentially the same. However, the 6AV6, with higher gain and improved separation between the diode and triode circuits, was considered to be the best.
  
 Regarding side getters and top getters, I don't think it makes any difference...  The 1950s GE tubes had top D-getters... and then side D-getters in the 1970s ... and then, top O-getters by around 1980. In my experience the 1950s GE with top D-getters sound the best. However, I can't say anything about other brands..


----------



## mordy

Did anybody compare the Pinnacle style side getter 6AV6 with the GE 6AV6 top getter?


----------



## Oskari

mordy said:


> From what I am reading, it appears the the mysteries of two mystery tubes have been solved:
> 
> 1) Siemens "Foreign" seems to be a Japanese Matshushiita/(Hitachi ?) tube


 
  
 Toshiba. On the other hand...
  


gibosi said:


> 1) Yes, this tube has been marketed under the Zaeix label. However, as Zaerix was a rebrander, one cannot assume that all Zaerix EH90/6CS6 are equal to the Siemens "Foreign".


 
  
 In this case, Siemens was a rebrander as well! In the same vein, we shouldn't assume that all Siemens "Foreign" tubes were made by Toshiba.
  
 I'm fairly convinced that the Canadian side-getters were made by RVC, Radio Valve Company of Canada Ltd.


----------



## gibosi

mordy said:


> Did anybody compare the Pinnacle style side getter 6AV6 with the GE 6AV6 top getter?


 
  
 I have not directly compared these, but my general feeling is that the RCAs are a bit more forward and bright.
  
 And I can provide a little more guidance regarding which GEs to purchase....
  
 GE 6AV6
  
 Currently, my go-to tube is the 1958 GE 6AV6. It has superb clarity and transparency, sweet mids and a punchy, detailed bass. Actually, I have had this tube for some time now, but initially felt that it wasn't all that great, so had put it aside. When I received the FIVRE and Toshiba tubes, I noticed how similar the construction of these tubes were to the GE and pulled it out for comparison. In the meantime, I had purchased new headphones and upgraded my op amp, and boy was I surprised when I heard these again! Finding an overlooked treasure in my "not good enough pile" was very sweet. 
  
 However, the fact that Audiofanboy reported that he was not all that impressed by his GE 6AV6 was somewhat disconcerting. And further, I have seen several versions of this tube on eBay that look quite different. So in an attempt to get to the buttom of this, I ordered two more GE 6AV6, each with different internal construction.  (And I should point out that that there also exist RCA and Sylvania manufactured tubes with GE paint. Typically, the classic sandblasted GE pattern with the tube number and dots is conspicuously missing on these tubes.)
  
 1958 GE 6AV6
  

  
 1974 GE JAN 6AV6. The metal box-like structure on the top mica is gone. It has a side-mounted square getter, located above the top mica. Compared to the 1958 GEs, it is as if the bass has been sucked out, leaving a rather shrill presentation. Not good.
  

  
 1980 GE JAN 6AV6. Halo getter, top mounted. But sound is similar to the 1974 GE with a rather shrill presentation. Not good.
  

  
 The specific changes in these newer tubes that make them sound like crap are likely undetectable to the naked untrained eye, but they appear to coincide with the removal of the box-like structure located on the top mica. So my recommendation is that if a GE 6AV6 doesn't have a metal box-like structure on the top mica, do not buy it.
  
 But there is more....  Apparently, the 1950s GE 6AV6 design was adopted and implemented by a number of other manufacturers, such as FIVRE and Toshiba (Multivox) below. Notice that both of these have the metal box-like structure on the top mica and diodes that resemble GE's plates with a rather steep peak. And more importantly, the sound of the FIVRE and Toshiba tubes is indistinguishable from my 1958 GEs. So if you see a 6AV6 that looks like a 1950s GE with peaky diodes and a box on top of the mica, there is likely a very good chance it will sound like a 1950s GE. And that is a good thing. 
  
 FIVRE 6AT6/EBC90 (1950s)
  

  
 Toshiba (Multivox) 6AV6/EBC91 (1970s)


----------



## gibosi

oskari said:


> I'm fairly convinced that the Canadian side-getters were made by RVC, Radio Valve Company of Canada Ltd.


 
  
 This seems reasonable to me. Further, I would speculate that in this instance, RVC simply licensed RCA's technology to enable them to manufacture what are essentially RCA 6AT6 and 6AV6 tubes.


----------



## TrollDragon

The Early Development of Radio in Canada, 1901-1930 (Second Column)
 Probably some in there as well about how RCA fir into the picture...


----------



## mab1376

These are my favorite 6AV6
  
 http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/2385#post_9709904
  
 Very detailed but not too much and clean punchy bass


----------



## kvtaco17

Ok a few impressions for you guys...
  
 GE 6DT6 (USA)
  

  
 Svetlana 6A2P
  

  
 Test chain FLAC>ODAC>LD MK1+> PS500/ AD2000x/Magnum V5
  
Epica - Blank Infinity   

  
 (I used the version on "The Classical Conspiracy Live" I used the studio version here because I couldn't find a decent version on youtube)
  
 Svetlana 6A2P
  
 The Svetlana's generally are warm sounding similar to an EH90 with less treble extension and air. They are full bodied and precise, great on intimate recordings, not so great here. Simone's voice is presented in a very small, narrow, odd,  direct manner... Adding a 1/7 strap helps add some air and space BUT I still didn't care much for these tubes here...
  
 GE 6DT6
  
 Open and airy with great detail and dynamics (should just label every 6DT6 this way it seems) These are great on this track, HOWEVER they have less bass extension and sound stage then the Sylvania and RCA 6DT6A's that Ive tested... think of it as a more focused 6DT6 (this is in both EF95 and 1/7) I like this tube BUT not as much as the other 2 6DT6's I've sampled. Everything is presented well, awesome airy vocals, good mid and treble detail... bass seems less textured and detailed then the other 6DT6's...
  
Rachel Sermanni - The Fog   

  
 Svetlana 6A2P
  
 Ok now I see what these are good for! They eat this track up and sound intimate and awesome! Great dynamics, detail and sense of space (a small but detailed space)
  
 GE 6DT6
  
 Well, I personally love the presentation here... although the size of the sound stage and seem somewhat artificial because of how simple the track is... Most of you will probably prefer the Svetlana's above... Dynamics are a little on the soft size vs the 6A2P.
  
Pantera - Cemetery Gates   

  
 Svetlana 6A2P
  
 No... just no... congested but detailed... flat... where did the instrument separation go?
  
 GE 6DT6
  
 Decent... a little diffuse vs the RCA/Sylvania  6DT6A and Valvo/Ediswan/Mullard EH90... average really... left me feeling indifferent...
  
Yo-Yo Ma, Stuart Duncan, Edgar Meyer, Chris Thile - Quarter Chicken Dark   

  
 Svetlana 6A2P
  
 Detailed but lacking air and space, very good sense of dynamics, fun. Good instrument separation and texture to the strings.
  
 GE 6DT6
  
 OK, but somewhat blurred... dynamics are flatter then I'd like... (in comparison to other tubes it is average, similar to the Siemens 6AK5W) Strings take on an odd tonality... I really can't describe it... nasally maybe?


----------



## Sony Slave

mab1376 said:


> You should try the OPA1611 and the LME49720 also, Also i very much like the warmness of the AD797.
> 
> These are all from my SS iBasso amp though.


 
  
  Quote:



kvtaco17 said:


> Got a pair of OPA627's yesterday... very similar to the TI OPA2107, but with much improved channel separation, slightly bigger sound stage, better instrument separation... so far  it sounds kinda like a hybrid love child of the OPA2107 and LME49990... I like it a lot!
> 
> 
> I also received the GE 6DT6 (grey plates and ribbed) Svetlana 6A2P (looks a lot different in construction vs other heptodes I've deal with) AND a new to me AD2000X (amazing cans I must say!)



  

  

 What op amps do you recommend for the 

*Tung-Sol 6AK5*,* Sylvania Gold Brand 5654*,*Voshkod 6ZH1P-EV* and the *Mullard M8100 / CV4010?*

  

  

 I want the op amps to bring out the best of each individual tube, without changing or altering the distinct characteristics of each tube. I've noticed that certain op amps do not go together well with other tubes.

  

 Does anyone have any suggestions?


----------



## i luvmusic 2

i'm wondering if 12AU7 will work with LD mk III.


----------



## gibosi

sony slave said:


> What op amps do you recommend for the
> *Tung-Sol 6AK5*,* Sylvania Gold Brand 5654*,*Voshkod 6ZH1P-EV* and the *Mullard M8100 / CV4010?*
> 
> 
> ...


 
  
 I find the LME49990 to be a very neutral op amp:
  
 http://www.ebay.com/itm/DUAL-SOIC-LME49990-DIP8-ADAPTER/190897295927?_trksid=p2047675.m1850&_trkparms=aid%3D222002%26algo%3DSIC.FIT%26ao%3D1%26asc%3D17396%26meid%3D1289909108227033573%26pid%3D100011%26prg%3D8093%26rk%3D1%26rkt%3D5%26sd%3D190888281070%26


----------



## kvtaco17

gibosi said:


> I find the LME49990 to be a very neutral op amp:
> 
> http://www.ebay.com/itm/DUAL-SOIC-LME49990-DIP8-ADAPTER/190897295927?_trksid=p2047675.m1850&_trkparms=aid%3D222002%26algo%3DSIC.FIT%26ao%3D1%26asc%3D17396%26meid%3D1289909108227033573%26pid%3D100011%26prg%3D8093%26rk%3D1%26rkt%3D5%26sd%3D190888281070%26


 
  
 I'll back that, It is very neutral!


----------



## mordy

Hi Gibosi,
  
 Thanks for the analysis of the 6AV6 tubes and "thinking out of the box."  As you may recall I did not like the 6AV6 tubes initially because of the strange sound stage where background instruments were brought to the front, something that apparently is exacerbated when listening through speakers.
  
 After your observation that the 6AV6 tubes with a box on top of the mica sounded better I went back to my pile of discarded tubes and fished out the five _single_ 6AV6 tubes that I have. (At one point I thought I could determine which one was the best sounding by listening to a good mono recording and alternating between channels and thus evaluating two tubes at once. This did not work, perhaps because there is some kind of synergistic effect between the two channels, even though the channels are totally separate.)
  
 Of the five tubes (three Sylvania, one RCA and one Tung Sol), two had the metal box on top of the mica. One is a Sylvania side getter and one a Tung Sol top getter. Changed the jumpers to EF92 ( don't cherish this operation) and popped the tubes in. First impression too much treble, but was able to tame it by turning down the treble all the way.
  
 Anyhow, the sound stage is normally sounding with the instruments where they are supposed to be. The treble is extremely detailed and clear. The bass is quite strong. Wide sound stage with very good 3D imaging and very good detail overall. The mid range has too much treble and voices sound nasal. _However, the presentation is very analytical and less musical_. It is interesting to listen to and I could see how somebody would like this type of sound. It is like studio monitor speakers that are used for evaluating recordings - all the detail is there, like holding a magnifying glass to the music.
  
 Personally, the toe tapping index is a meager 1 by me, and I need a different more musical sound with real good slam in the bass to be happy. Anyhow, for now I'll leave them in and see if I can get more used to them.
  
 Edit: Starts to sound better. Don't know if the LD needs time to adjust or if it is me, but the treble got less sharp, and I am enjoying the holistic 3D sound stage with the great details. All right, so you could argue that I don't have a real pair of tubes, which is true. However, several posts mentioned that the 6AV6 tubes sound very similar. In this case the Sylvania plays louder (as is often the case with Sylvania tubes in my experience). I moved my balance control a little to get the center instruments in the middle and everything is swell...Voices are more natural.  TT index moved up to 3.


----------



## gibosi

> Originally Posted by *mordy* /img/forum/go_quote.gif
> 
> ....Anyhow, the sound stage is normally sounding with the instruments where they are supposed to be. The treble is extremely detailed and clear. The bass is quite strong. Wide sound stage with very good 3D imaging and very good detail overall. The mid range has too much treble and voices sound nasal. _However, the presentation is very analytical and less musical_. It is interesting to listen to and I could see how somebody would like this type of sound. It is like studio monitor speakers that are used for evaluating recordings - all the detail is there, like holding a magnifying glass to the music.
> 
> ...


 
  
 With your Sylvania/Tung-Sol "pair", you are in uncharted territory! I don't own a similar pair, so I have no idea how they sound. lol  
  
 While the 6AV6 are similar, they are not identical. For example, among the American brands I possess, the RCA are noticeably brighter and more forward than the GE. And I would say that the Sylvania are somewhere in between. (And the European brands are also quite different from one another.)
  
 But yes, I generally agree with your observations. There is a level of clarity and transparency that seems to allow one to have the sensation of peering into a holistic 3D sound stage with a magnifying glass. The treble on the GEs is very detailed and clear, but not at all peaky, and vocals seem somewhat sweet and warm, but still quite natural. So while the bass could have a bit more slam and their musicality is a bit lacking compared to the best pentodes/heptodes, the GEs continue to remain my go-to tubes.


----------



## mordy

Hi Gibosi,
  
 Always makes me feel good when somebody agrees with me - lol. Truth is that one of the things I like about this forum is the honesty of the reviews, and the tolerance of others if they don't agree.
  
 Anyhow, I am trying to quantify in my mind what I like and don't like about my 6AV6 configuration. Have you seen black and white photographs with a very high contrast? Everything is there, but it is a bit unnatural. Interesting, plenty to look at, but ultimately lacking something, although, as said, I can readily understand people who like this. The picture below sums it up:
 Tons of detail, gobs of information, everything is there, but....
  
  





  
  
  
 Trying to picture what my RCA and Raytheon (Japanese) Dtox tubes sound like:
 Beautiful, warm, expansive, involving and




  toe tapping:




  
 Have fun!
  
 Edit: After having cooked the tubes another 14 hours, the bass is tightening up, and the treble is getting less harsh. Looks promising.....The listening experience is improved with voices more natural, but don't understand why the (subconscious) TT index is not moving up beyond 3.


----------



## MIKELAP

Here are a couple of musical test    http://jakemandell.com/amvi/    and      http://tonometric.com/rhythmdeaf/   have fun!


----------



## mab1376

gibosi said:


> I find the LME49990 to be a very neutral op amp:
> 
> http://www.ebay.com/itm/DUAL-SOIC-LME49990-DIP8-ADAPTER/190897295927?_trksid=p2047675.m1850&_trkparms=aid%3D222002%26algo%3DSIC.FIT%26ao%3D1%26asc%3D17396%26meid%3D1289909108227033573%26pid%3D100011%26prg%3D8093%26rk%3D1%26rkt%3D5%26sd%3D190888281070%26


 
  
 I found it to be extremely sibilant, i would try the AD797 or AD823.


----------



## mordy

Did not get that good test results. Chalk it up to old age....
  
 Test is a lot of fun though.....


----------



## siles1991

I'm 22 years old and got normal for everything. Or it could be my superlux headphone im using for it.


----------



## MIKELAP

mordy said:


> Did not get that good test results. Chalk it up to old age....
> 
> Test is a lot of fun though.....


 
 The first test is  not easy at all never tought of music like that before .


----------



## kvtaco17

mab1376 said:


> I found it to be extremely sibilant, i would try the AD797 or AD823.


 
 it can be with some tubes and sources... I really liked it when it sounded good BUT it seemed so picky... I prefer the OPA627AP personally... or the OPA2107AP if you're looking to save a bit. My personal preferences lean to the warm side of neutral.


----------



## mordy

I was brought up that if you did not get an A don't bother to show your test results. I too got Normal on the test LOL.


----------



## kvtaco17

mordy said:


> I was brought up that if you did not get an A don't bother to show your test results. I too got Normal on the test LOL.


 
  
 80 and 82 respectively!  (that's kinda like an A?!)


----------



## mordy

Congratulations! I only got around 60...


----------



## kvtaco17

mordy said:


> Congratulations! I only got around 60...


 
 No shame in that!


----------



## Edgard Varese

mikelap said:


> Here are a couple of musical test    http://jakemandell.com/amvi/    and      http://tonometric.com/rhythmdeaf/   have fun!


 
  
 95% on the first one... only 76% on the second one.


----------



## kvtaco17

edgard varese said:


> 95% on the first one... only 76% on the second one.


 
 Well done!


----------



## MIKELAP

mordy said:


> I was brought up that if you did not get an A don't bother to show your test results. I too got Normal on the test LOL.


 
  
 Those were the days nightmarish actually  trying to learn my multiplication tables never got A'S i wonder why.I averaged 70% in both test.


----------



## MIKELAP

edgard varese said:


> 95% on the first one... only 76% on the second one.


 
  
 Thats great Edgard i found the first very special.


----------



## TrollDragon

The first one was a little confusing at first till I understood what he was looking for... 75% and 80% here.


----------



## MIKELAP

kvtaco17 said:


> 80 and 82 respectively!  (that's kinda like an A?!)


 
  
 Thats great, found that test on the Burson Conductor thread from dan. gheorghe he got 100% on first test and 96% very bright people on headfi, and who benefits from that ALL OF US.Thats great!


----------



## MIKELAP

trolldragon said:


> The first one was a little confusing at first till I understood what he was looking for... 75% and 80% here.


 
Great ,It was confusing didnt expect that also


----------



## i luvmusic 2

I got my LD mk III 7 days ago and i love the sound of it.
 First 3 days i've listened to it i was disapointed how i need to turned the volume knob up to 80 mark just to have a comfortable listening level.
 Then i tried burning it in for 4 days,i leaved it on for 8 hours then turned it off .leaved it off for few hours then turn it back on for another 8 hours i did these for 4 days.
 Today i decided to start listening to it again and i noticed that as soon as i turned the volume knob it play louder than before i set it to 40 mark and it's loud enough for me.
 Is these normal?


----------



## MIKELAP

i luvmusic 2 said:


> I got my LD mk III 7 days ago and i love the sound of it.
> First 3 days i've listened to it i was disapointed how i need to turned the volume knob up to 80 mark just to have a comfortable listening level.
> Then i tried burning it in for 4 days,i leaved it on for 8 hours then turned it off .leaved it off for few hours then turn it back on for another 8 hours i did these for 4 days.
> Today i decided to start listening to it again and i noticed that as soon as i turned the volume knob it play louder than before i set it to 40 mark and it's loud enough for me.
> Is these normal?


 
  
 Whith my 300 ohms senns hd800 with gain switches off 25 is pretty loud with hi res files and 30 with regular recordings your DT 880 are 600 ohms .Thats weird and you didnt change the gain switches under!


----------



## mordy

Hi All,
  
 After burning in the 6AV6 tubes with the boxes on top of the mica for 25 hours I have completely changed my mind about them. These tubes now sound terrific without any harshness in the treble and with great powerful bass. Voices are natural and the sound stage and 3D holographic imaging is super. This is how it looks graphically:
  





  
 Is this image real? Yes - the Rainbow Mountains In China's Danxia Landform Geological Park Are Very, Very Real. Minerals in the ground account for the rainbow of colors.


----------



## gibosi

> I found it to be extremely sibilant, i would try the AD797 or AD823.


 
  
 I am very comfortable in saying that this chip is not inherently sibilant. The LME49990 is a very high quality audio op amp that can often be found in high-end audio equipment. However, that said, these chips do not operate in a vacuum. For best results, an op amp should be implemented into a circuit specifically designed for it. When a chip is simply rolled into an existing circuit, it may well perform below its potential. If it is biased incorrectly, it may oscillate and do all kinds of nasty things. Further, sibilance may in fact be due to a mismatch between other components in the audio system, such as driver tubes and headphones, and not the op amp at all.
  
 I have the LME49990 installed in my LD1+ and the only time I hear sibilance on my HE-300s is when the recording itself is sibilant. (And I have rolled a rather large variety of driver tubes, including triodes, pentodes and heptodes into this amp.)
  
 Again, this is a top-tier op amp, and if the OP wants neutral, this should be on his short list. And in the end, the only way to know if it will be good fit in any given system is to buy it and give it a try.


----------



## Edgard Varese

mikelap said:


> Thats great Edgard i found the first very special.


 
  
  
 I found the second one confusing... at first I thought I was listening for small variations and probably picked a few items as being different when they weren't.


----------



## Acapella11

Funny test. Tried the first one. Got 85 % after a beer.


----------



## Edgard Varese

audiofanboy said:


> Those tubes you mention are CGE 6DT6A Japan "made to CGE specifications" right? I just got the same tubes in the mail, and threw them on the amp for a thorough burn-in; so I'm interested in your experience with them!
> 
> First impressions are favorable; indeed the bass roars with these! Too many of the recent tubes I tried either smeared mid-bass and bass or just left it out of the picture entirely.
> 
> ...


 
  
  
 I've been listening to these GE 6DT6A tubes for a few days now and I am thinking that I really need to try them on EF92 (I'm constitutionally disinclined to open up the amp and fiddle with the switches - simple laziness!).  I'm listening with a pair of RS1is, and while impressed with the bass at first, I am finding that the tubes are rather too trebly in this setting (which is sonic death with these headphones).  In addition, it just seems as though the balance is not quite right... I normally steer fairly clear of EQing, but I have been strongly tempted the last couple of nights.  I'm wondering whether the EF92 setting would make them seem more balanced and less trebly.


----------



## Audiofanboy

edgard varese said:


> I've been listening to these GE 6DT6A tubes for a few days now and I am thinking that I really need to try them on EF92 (I'm constitutionally disinclined to open up the amp and fiddle with the switches - simple laziness!).  I'm listening with a pair of RS1is, and while impressed with the bass at first, I am finding that the tubes are rather too trebly in this setting (which is sonic death with these headphones).  In addition, it just seems as though the balance is not quite right... I normally steer fairly clear of EQing, but I have been strongly tempted the last couple of nights.  I'm wondering whether the EF92 setting would make them seem more balanced and less trebly.


 
  
 All I can tell you is that these are the most pleasant -i.e. toe-tapping- tubes I've tested since I started rolling again a couple of weeks ago; and a solid part of that pleasantness is because they are balanced imo. EF92'd that is. As Daft Punk would say, these tubes just "bring life back to music"!
  
 No need to open up the amp to change jumpers, you just need to get in there through the holes underneath the chassis. The jumpers are annoying to change but the change is often worth it just for experiment's sake.
  
 Worst case, you can always just 6-7 strap the sockets... Though it takes about as much effort making the appropriate wires as changing the jumpers really...
  
 Happy jumper changing at any rate...


----------



## Edgard Varese

audiofanboy said:


> All I can tell you is that these are the most pleasant -i.e. toe-tapping- tubes I've tested since I started rolling again a couple of weeks ago; and a solid part of that pleasantness is because they are balanced imo. EF92'd that is. As Daft Punk would say, these tubes just "bring life back to music"!
> 
> No need to open up the amp to change jumpers, you just need to get in there through the holes underneath the chassis. The jumpers are annoying to change but the change is often worth it just for experiment's sake.
> 
> ...


 
  
 That's me fiddling around inside the amp then tonight!   A dealer close to me has a pair of Brimars that run in EF92 so I might purchase those as well while I am experimenting...


----------



## Iron58p

Today i want to talk about a pair of Jan GE 6AV6 5960, year 1973 ( cutted pin 5 and 6 ), EF92.
  
 I have bought from NOS tube, for a price of 4 $ for a tube.
  
 Sounds very well, as some other brands tryed before, detailed and transparent, voices forward and on your face, only a little harsh on hights, very good soundstage and separation of musical instruments, i have tried only a half hour ago, so passing the time and burning can change of course the sound.
 Bass like this, never heard before, seems come from the deep and 3D.
  
 On my ears have a thing that only people that have Grado headphones can understand :  electric and acoustic guitar are unique, and improve the grado sound.
 May be that being a novice, other people say that is not true, but i think that for 4 $ each  if someone want to give a chance to this cheap tubes, may have a good surprise, in special mode if you have a Grado or Alessandro headphones.
  
 Tomorrow i will make a photo, there are 2 Printing in different colors, grey and green..


----------



## i luvmusic 2

mikelap said:


> Whith my 300 ohms senns hd800 with gain switches off 25 is pretty loud with hi res files and 30 with regular recordings your DT 880 are 600 ohms .Thats weird and you didnt change the gain switches under!


 
  
 no i have not get to that part.i know it's weird.


----------



## mordy

Hi AFB,
  
 I am glad that the prescription from Dr. Mordy worked:
  
  
 AFB: "I kind of got annoyed at my latest pairs of tubes last night... Basically, _none_ of them sounded right to me at this point."
  
 Dr. Mordy: "So what to do to bring back the excitement and enjoyment? Play a really well recorded track with your favorite combination of tubes and just enjoy the music. Listen for new details emerging, estimate how wide the sound stage is (in my case how far outside the speakers the sound seems to emanate, tested with closed eyes and pointing a finger to where the sound seems to come from - I mean, u need a little exercise while listening), listen how realistic the cymbals and bass drum sound. With a good recording and great tubes the magic comes back....
  
 My present favorite combination is the IR tubes with DTox. A very sweet mid range, plenty of detail, and all the punch and slam and shimmer I want in the lows and the highs."
  
 AFB: "All I can tell you is that these (6DT6) are the most pleasant -i.e. toe-tapping- tubes I've tested since I started rolling again a couple of weeks ago; and a solid part of that pleasantness is because they are balanced imo. EF92'd that is. As Daft Punk would say, these tubes just "bring life back to music"!"
  
 Now I have a question: The Dtox tubes are just great and very involving and musical with a TT index of 5+. Having re-discovered the 6AV6 tubes (BTW, I have never come across tubes that changed more after burn in than the 6AV6; it's like all the imperfections burned away) they sound truly great with a huge holographic 3D sound stage and immense detail. But listening to them I feel like I am at the platform overlooking the Rainbow Mountains in China. It's ooh and ah, but a little distant and less involving, manifest by a TT index of 3. Why?





 I could listen all day long to the 6AV6 tubes but why do they not engage me emotionally as much as the Dtox tubes. Why? (Still extremely enjoyable.)
  
 Could it be that the 6AV6 appeals more to the intellectual faculties and the 6DT6 to the emotional faculties?
  
 Just switched from the 6AV6 to my Japanese 6DT6 and I am catching myself toe tapping.
  
 Here is a picture of the Heptoad enjoying toe tapping music:
  




  
 Man, I can't keep my right foot still!
  
 The Dtox make me feel good, the 6AV6 make me marvel. In the words of the end of the Vitaphone clips of the 20's: That's it, there ain't no more!


----------



## mink42

Can anybody give any insight as to whether to go for the MKIII or MKIV? Planning on doing some tube rolling in the future.
  
 Setup will be STX>LD MKXX(X)> Sen HD600
  
 Have had trouble finding some comparisons so far


----------



## Edgard Varese

First impressions of GE (Japan) 6DT6 on EF92 setting... quite positive.  At the moment it sounds like the sibilance is tamed a bit, while retaining a nice balance otherwise between bass and mids.  But I'm going to listen more.
  
 The thing that bothers me is that I knew I didn't want to fiddle with the amp for a reason... I dropped a screw and lost it, of course (I'm a bit awkward and clumsy with these kinds of things, which is why I was reticent about strapping earlier).  Anybody got a spare screw for a Little Dot I+?


----------



## MIKELAP

mordy said:


> Hi AFB,
> 
> I am glad that the prescription from Dr. Mordy worked:
> 
> ...


----------



## TrollDragon

The Neutrik NJ3FP6C-B has arrived and the quality of this jack is literally night and day from the original one.

  
 While I was installing this new jack I was going to put a couple of switches in the back of the case for strapping, two single pole double throw's with (On/Center Off/On) would give you 1-7 / EF95 / 2-7 by just flipping the switch. Alas I had no Center off switches just SPDT's, so that is a stop at the electrical suppliers. 
  
 Here is a very interesting revelation... I understand the the Pre Out has no protection circuitry but in looking at the board it appears the Headphone Jack has NONE either.

  
 The larger gauge Red, Black and Blue wires on the bottom of the board attach to the headphone jack. The smaller gauge Brown, Black and Blue wires on top go directly to the Pre Out RCA jacks on the chassis back. I was under the assumption the Pre Out was a different part of the board circuitry, not just a piggy back on the Headphone Jack.
  
 So in buying "NOS" tubes from eBay and Rajindar the tester/shipper guy is having a busy day, he forgets to put a few tubes through the tester... He drops a shorted one in your order, you plug the new tubes in and smoke rolls out of one of your HD800's driver... Not good... He says "My tube is guarantee" in his auction and that he'll replace the bad tube for you no problem!
  
 So this amp provides no protection for your headphones as well. I don't know if all OTL's are like this or not but it is very disconcerting to know this could happen because of a $3 tube... Some food for thought and I don't know what the chance of this happening would be if at all.
  
 Anyhow enough of the _*Prophecies of Doom*_...
  
 Here is the MK IV with the new jack installed.

  
 Cable connected and the DT880's sounding as great as ever.


----------



## MIKELAP

trolldragon said:


> The Neutrik NJ3FP6C-B has arrived and the quality of this jack is literally night and day from the original one.
> 
> 
> While I was installing this new jack I was going to put a couple of switches in the back of the case for strapping, two single pole double throw's with (On/Center Off/On) would give you 1-7 / EF95 / 2-7 by just flipping the switch. Alas I had no Center off switches just SPDT's, so that is a stop at the electrical suppliers.
> ...


 
  
 i guess its related also to the fact why i cant use the mk3 with my Pioneer amp because of the caps ! And i would not be happy to see my HD800's drivers go up in smoke 
	

	
	
		
		

		
		
	


	




 i think after that horror story ill use a cheap pair of  headphones for burnin .Come to think of it when you burnin tubes do you have to have a headphone plugged in if so why exactly never tought of it actually. Any data on this guys .


----------



## mink42

It's generally recommended to have your cans plugged in during burn in


----------



## TrollDragon

As I read more and more about this, a lot of the people out there who roll and "tinker" with different tubes have picked up a used tube tester for checking tubes they buy. I'll dig up more info on this.

Update:
Well unless you are selling tubes then a simple emissions tester will work to check for shorts.

Gleaned from AK...


> If you are just wanting to determine good from bad and shorted tubes a simple emissions tester will be more than enough to work. If this is your first tester I would recommend buying a small, decent emissions tester like a Sencore Mighty Mite or other respected emissions tester, make sure that works and then you can move up to a transconductance tester if you still feel you need one after using the emissions tester for a while.
> 
> The best test as they say is to make sure it is not shorted and works and then plug it into the circuit it will be used in.



http://www.audiokarma.org/forums/showpost.php?p=5486527&postcount=13

Maybe I am just getting too wound up in the possibility of failures and should just not worry.

I *would* use cheap headphones for initial power up and burn in, just to be safe.


----------



## MIKELAP

Do these  6n30p DR tubes look original first pair to be from 1979 for $161.00 and second set around same price from 1990. Whats the verdict thanks.


----------



## TrollDragon

Well the USAF 6AH6WA's have arrived, I used the rubber nubby that MIKELAP suggested as there was one in my 500 piece CTC Rotary Bit Kit. 400 of the 500 pieces are sanding disks but that's another story... And it works like a charm! Thanks MIKELAP for the excellent tip!

Two strands of 30 AWG bare wire wrap wire are now soldered between pins 2 & 7, let me tell you that was a fun job in itself.

My fingers are absolute poision to the markings on tubes. I am going to have to devise a way to hang into the tube while cleaning pins without removing all the letters...  

Maybe cotton gloves or something similar.

Now to put them in and see if I destroyed them with the soldering job.

The things we do in the quest of audio greatness, I'll need to find a sound picture like Mr. mordy has to describe these tubes.


----------



## TrollDragon

WOW these USAF 6AH6WA's are the absolute best tubes I have heard to date...
 Just like David Crosby said "Separate the Whe-eat, from the Chaff".
  
 The Sound picture of these tubes.

 After running the 6BY6's for a while which I was really enjoying the sound of, it has a good bass presence that I tend to crave. I found the 6BY6's a nice step up over the stock GE 5654's which have very little bass to speak of.
  
 Then I popped in the 6AH6WA's... Incredible, it's like I am listening to a totally different amplifier. The clarity and dynamic range has increased 10 fold in my opinion. The bass is punchy, goes deep and is very, very enjoyable. After listening to these new tubes for a few hours I am finding the 6BY6's bass which I enjoyed, starting to be a little muddy now...  
  
 Tracks Tested with the USAF 6AH6WA's
  
*Dire Straits*
 Walk of Life, Lady Writer and Money for Nothing.
  
*The Doors*
 L.A. Woman, The WASP and Riders on the Storm.
  
*Santana*
 Black Magic Woman.
  
*Crosby, Stills and Nash*
 Wooden Ships, Déjà Vu and Almost Cut My Hair.
  
 Some amazing tracks through the DT880's IMHO.
  

  
 Permanent strapping of 2 & 7

  
 The lit up version, these tubes are not really a nice tube for the LED glow.

  
 Thanks to gibosi for recommending that I might like this tube!


----------



## MIKELAP

trolldragon said:


> WOW these USAF 6AH6WA's are the absolute best tubes I have heard to date...
> Just like David Crosby said "Separate the Whe-eat, from the Chaff".
> 
> The Sound picture of these tubes.
> ...


 
  
 Your not alone to like these tubes they are among my favorite tubes also. I have 10 sylvania JAN 6AU6WA on the way will be good for a while with these .Burnin in G.E. JAN 6136 at the moment you probably know that you can buy socket adaptors for those EF95 TUBES right you leave jumpers on EF92 setting and you plug in your EF95 tubes in socket adaptor . Heres a picture and a link where you can buy these adaptors in China i bought them there a while ago and also adaptors for 6AH6 and 6AU6 TUBES got infos in next post  they are $38.00 shipped if your interested .
    http://www.ebay.com/itm/1x-EF95-EF91-EF92-Vacuum-tube-adapter-socket-converter-/300961753333?pt=Vintage_Electronics_R2&hash=item4612b7e8f5


----------



## MIKELAP

trolldragon said:


> WOW these USAF 6AH6WA's are the absolute best tubes I have heard to date...
> Just like David Crosby said "Separate the Whe-eat, from the Chaff".
> 
> The Sound picture of these tubes.
> ...


 
  
 Your not alone to like these tubes they are among my favorite tubes also. I have 10 sylvania JAN 6AU6WA on the way will be good for a while with these .Burnin in G.E. JAN 6136 at the moment you probably know that you can buy socket adaptors for those 6AH6and 6AU6 TUBES right. heres a picture and a link where you can buy these adaptors in China they are $38.00 shipped if your interested the way they are made your amp is on the EF95 setting you put the adaptors in the amp and your 6AH6 OR 6AU6 tubes in adaptors and your good to go .                                                 http://www.ebay.com/itm/2x-6AU6-6AK5-tube-adapter-socket-converter-free-shipping-/300960155101?pt=Vintage_Electronics_R2&hash=item46129f85dd


----------



## mab1376

mikelap said:


> Your not alone to like these tubes they are among my favorite tubes also. I have 10 sylvania JAN 6AU6WA on the way will be good for a while with these .Burnin in G.E. JAN 6136 at the moment you probably know that you can buy socket adaptors for those EF95 TUBES right you leave jumpers on EF92 setting and you plug in your EF95 tubes in socket adaptor . Heres a picture and a link where you can buy these adaptors in China i bought them there a while ago and also adaptors for 6AH6 and 6AU6 TUBES got infos in next post  they are $38.00 shipped if your interested .
> http://www.ebay.com/itm/1x-EF95-EF91-EF92-Vacuum-tube-adapter-socket-converter-/300961753333?pt=Vintage_Electronics_R2&hash=item4612b7e8f5


 
  
 I bought those adapters and they didn't work


----------



## MIKELAP

mab1376 said:


> I bought those adapters and they didn't work


 
  
 They work fine here i put my amp on EF 92 setting and my EF95 tubes in the sockets if i remember when he first made them they were not working but he sent me another pair with the right configuration that work fine i have been using them for a while now same for the 6AH6 and 6AU6 socket adaptor


----------



## TrollDragon

mikelap said:


> Your not alone to like these tubes they are among my favorite tubes also. I have 10 sylvania JAN 6AU6WA on the way will be good for a while with these .Burnin in G.E. JAN 6136 at the moment you probably know that you can buy socket adaptors for those 6AH6and 6AU6 TUBES right. heres a picture and a link where you can buy these adaptors in China they are $38.00 shipped if your interested the way they are made your amp is on the EF95 setting you put the adaptors in the amp and your 6AH6 OR 6AU6 tubes in adaptors and your good to go .                                                 http://www.ebay.com/itm/2x-6AU6-6AK5-tube-adapter-socket-converter-free-shipping-/300960155101?pt=Vintage_Electronics_R2&hash=item46129f85dd


 
  
 These infact do look very useful for sure!
 If I do gather a collection of 6AW6's which I am thinking would be a good idea, I'll get a pair of these to go along with. A lot easier than soldering to the pins of the tube.
  
 These would be so easy to DIY but there are very few B7G parts that I can find, lots of sockets but the plug bit is the hard one to locate...


----------



## MIKELAP

trolldragon said:


> These infact do look very useful for sure!
> If I do gather a collection of 6AW6's which I am thinking would be a good idea, I'll get a pair of these to go along with. A lot easier than soldering to the pins of the tube.
> 
> These would be so easy to DIY but there are very few B7G parts that I can find, lots of sockets but the plug bit is the hard one to locate...


 
  
 When needed i use both pair of socket adaptors leaving EF92 setting on amp this is my famous REACH FOR THE SKY setup


----------



## TrollDragon

mikelap said:


> When needed i use both pair of socket adaptors leaving EF92 setting on amp this is my famous REACH FOR THE SKY setup


 
 I just Love it! 
	

	
	
		
		

		
		
	


	



  
 The cloud and sky are nice touch. It looks like some sort of Candu reactor type thing, or the smoke stacks from the Coal Fired power station down here in Dartmouth.


----------



## mab1376

mikelap said:


> They work fine here i put my amp on EF 92 setting and my EF95 tubes in the sockets if i remember when he first made them they were not working but he sent me another pair with the right configuration that work fine i have been using them for a while now same for the 6AH6 and 6AU6 socket adaptor


 
  
 I used them in reverse lol, EF95 settings with the adapter and 6AV6 tubes.


----------



## MIKELAP

mab1376 said:


> I used them in reverse lol, EF95 settings with the adapter and 6AV6 tubes.


 
 When i got the second pair they were not working either because i told the guy i wanted the adaptors to plug in the amp at the EF95 setting but he made them to use the EF92 SETTING i found that out when i went to the guys website for the adaptors and went to the bottom of the page and he specifies what setting to use in the amp.


----------



## Audiofanboy

"_And now for something completely different__._"
  
 OK, so I tried to ramp up the difficulty level a bit lol. Don't try to reproduce the experiment I'm about to show you at home, unless you _really_ know what you're doing -I hardly am!
  
 So, I'd been looking for 7-pin socket adapters -versatile adapters, not one-shot adapters that make a tube type into an other and nothing else- for a while, and finally bumped into a website that sold quality NOS adapters for cheap. Shipping across the world was cheap too, so I bought three pairs of adapters. They finally got here today.
  
 Now, I'd had -and still have- a number of ideas in my head of new tube types to try on our LD amps, most of which would require some thorough pin reworking, but there was this one experiment I wanted to try first; ironically it was the most challenging one. Using one of those ubiquitous double triodes that everybody loves on my LD amp! It's a good thing I had an old mil spec Mullard M8162 lying around (it came with a box of very random tubes months ago, back in the EF91 days). So, I started working on adapting that single 12AT7 tube on my two-separate-pentode LD!
  
 Here's a picture of the adapter/tester/savers I got. Brand name is Vector, and they seem to have been a reference back in the tube days.
  

  
 The tube I adapted: Mullard M8162 / CV4024, mil spec 12AT7, Mitcham-made; barely legible when I took the picture 8 months ago, and even less now that I manhandled it into submission...
  
 Just your basic 12V, center-tappable, high-mu double triode. I just realized that this a $30 tube on ebay, actually, so maybe not that basic.
  

  

  
 I'll cut to the chase and just illustrate what I did with a picture (how's my "reach out to the gods" setup Mikelap lol?), just so you can see just how unpractical this whole setup is -and how crazy an attempt to adapt a tube it is!
  
 Basically, I chopped up some old computer cables and stripped them on one end. The other end I used with its metal hole to squeeze onto the tube pins as DIY air socket holes (R) (with great difficulty and little fate that the contacts will last long). The stripped end of the wires I attached to the socket adapters' tester tabs in a non-destructive way (the adapters can be unscrewed and opened -which I had been hoping for since it was what I needed- so I squeezed the bare wiring underneath the tester tabs and screwed the adapters closed again).
  
 Made each of the nine wires (9 pin double triode) go to the appropriate pins on the tube, and socket holes on the amp; using the heater center tap to power the tube (so pins 4+5 to one of the heater pins on one of the sockets, and pin 9 to the other heater pin on the same socket), and rerouting each triode pins to the appropriate pins on each socket. The pieces of paper below the tube aren't to make it pretty; they're there because I was very scared that the wires would touch each other, and they would have otherwise!
  
 Interestingly, it only took me two attempts to make this mod work (I was expecting it to fail; I didn't even know if the tube was good). First time I had messed up some wires on the right side, so the heaters -fortunately- didn't power on, and I was spared the awful PPSHhhh noise, just got silence.
  

  
 On my second attempt -a bit more thorough than the hasty first one- everything worked perfectly!! Filaments lighting up, music in both channels: success! I did get a bit of noise in one channel for half a second, but I know that's because the tube is barely attached to the wires and _kind of hanging from nowhere_, so I wasn't surprised. It worked flawlessly for 15 minutes after that.
  
 What is even better is that it sounded great, which is not an easy feat considering that everything was wrong with this mod: wrong number of tubes, wrong tube type, wrong number of grids, extra 50 years old adapters, 15cm of crappy wiring without shielding, dubious tube...  But still, it sounded as good as my current fav' 6DT6 tubes, so top-tier. Very natural and musical sound, detailed and realistic but still toe-tapping; I guess double triodes are cool too huh?
  
 It does kind of look like the amp is holding up a tube as an offering to the gods though lol. I'd imagined it would have looked even more rigged, so this isn't even that bad for a quick test.
  

  
 Like I said earlier, the adapters unscrew, and the whole top part comes off with the pins and tester tabs, so you can squeeze stuff in there and not destroy an adapter by soldering wires for every new pinout you want to try.
  

  
 Anyway, interesting experiment. Unpractical for sure, but my goal was just to prove that it worked, not to leave it there. Not only did it work but it sounded great! So, I'll be investigating this a bit longer. If a 12V center tapped double triode can be made to work on this amp, you can sure bet a 6V double triode like the 6DJ8 would too! And these are supposed to be very very nice tubes.
  
 Notice how such a setup would use less power than our typical tubes: a single 0.3A heater instead of often two in our pentodes. Then again, the "prettier" solution using double triodes here would probably be to just use one per channel with a clean 9 to 7 pin adapter, and only use one triode out of the two in each tube. More expensive and a bit silly, but it would be the only way to not have a tube floating in the sky on top of your amp between sockets...
  
 I had to open up my amp a few days ago and took the opportunity to take -non-destructive- pictures as best I could. You can't see much but it gives you a pretty good idea of what is in a MK IV SE, seen from the front. Pics can be enlarged if you actually want to see something.
  

  
 Edit: See that wooden thing on the picture above? That's my solution for changing jumpers easily. Glued a match stick to an elongated jumper so that the wooden part pokes out by maybe 2 mm outside the amp, meaning that I can grab and change the jumpers by hand.


----------



## hypnos1

Hi guys.
  
 The RCA 6DT6As have finally arrived, and with 20+hrs on 'em I have to admit my beloved 'Siemens' EH90s (Blackburns) are being put slightly to shame...these are giving more in all departments (which I didn't think was really possible - should have known better!), especially -  as AFB has mentioned - in the mid-bass area. They are SERIOUSLY good tubes...well done the Masters who have found and championed these tubes. Particularly as they do not need any fancy mod - just 6-7 strap on my MK IVSE, and certainly nothing like Audiofanboy's amazing/scary last experiment. CRAZY man!!
  
 I think I may have also been a little lucky in getting 2 of the 4 I received appearing absolutely identical - with smooth plates - while the other 2 have ribbed plates, and NOT looking so identical (shades of  'Siemens' tubes all over again...). These things are pairing with my 6N30P-DRs like a marriage in heaven - and that's with my humble HD650s (helped along by pure silver cable, though).
  
 Can't wait to see what another 20 hrs burn-in brings - surely they can't get any better than this! Or can they?,,,
  
 BTW - they are WAY louder than even the EH90s on 6-7...


----------



## mojorisin35

Mike, re the super tubes:
 From the pics they look not too bad however what some sellers will often do is use “stock real tube photos” instead of photos of the real tubes. Tricky yes! So I have asked for close up pics of the flaps both sides, bottom of the mica, getter, and  the tubes on piece of paper with my name and date in the pics. The response is usually an ok give me some time or a defensive no. if they pass the test on page 96 then i say go for it and definitely go with the ones from 1979
 Hope this helps
 Gary


----------



## gibosi

A pair of Tung-Sol 6AV6 arrived today:
  

  
 These have the "box" mounted on the top mica, GE-style diode plates with halo getters, and look very similar to the Multivox/Toshiba 6AV6. However, the Tung-Sols have black plates, and the mica and getter splash are different. Moreover, 6AV6 USA is etched in the glass, so it would appear that these were not manufactured in Japan by Toshiba. Next, will cut off some pins and begin to burn them in.
  

  
 And the Toshiba 6AV6:
  
 http://vintageaudiotube.blogspot.com/2011/10/toshiba-6av6.html


----------



## mab1376

I guess AFB is the Dr. Mengele of LD amps.
  

  
 ...just kidding lol, looking forward to how the 12AT7 works out for you!


----------



## Audiofanboy

mab1376 said:


> I guess AFB is the Dr. Mengele of LD amps.
> 
> 
> 
> ...




I would do anything for science lol!

The next iteration will look less cruel; I ordered some 9 pin sockets to solder.

Don't worry though, I have a few other better looking ideas in the pipeline.

That picture does look half way between a tube getting sacrificed and just a technical aberration...


----------



## Iron58p

Someone can please explain to me  what is the meaning of O-getters or D-getters ?
  
 What part of tube i must to look ? For example, i'm referring to my TS 6AH6WA, but i have no idea where and what to look.
  
 Thank's


----------



## Oskari

iron58p said:


> Someone can please explain to me  what is the meaning of O-getters or D-getters ?


 
  
 See http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/555#post_8951850


----------



## Iron58p

Ok, thank's again, now i know that my TS 6AH6WA 1964 are O-getters.
  
 I think to be lucky


----------



## mab1376

iron58p said:


> Someone can please explain to me  what is the meaning of O-getters or D-getters ?
> 
> What part of tube i must to look ? For example, i'm referring to my TS 6AH6WA, but i have no idea where and what to look.
> 
> Thank's


 
  
 Its physically the shape of the getter. The shape can be used to identify the the same tube make & model came from different factories or different dates.
  
 A *getter* is a deposit of reactive material that is placed inside a vacuum system, for the purpose of completing and maintaining the vacuum. When gas molecules strike the getter material, they combine with it chemically or by adsorption. Thus the getter removes small amounts of gas from the evacuated space.
  
 http://en.wikipedia.org/wiki/Getter


----------



## MIKELAP

audiofanboy said:


> "_And now for something completely different__._"
> 
> OK, so I tried to ramp up the difficulty level a bit lol. Don't try to reproduce the experiment I'm about to show you at home, unless you _really_ know what you're doing -I hardly am!
> 
> ...


----------



## MIKELAP

mikelap said:


> Like Arte Johnson ( 70's tv show Rowan and Martin Laughin) would say ¨ Very interesting¨  . I would call that Audiofanboy's REACH FOR THE STARS setup .Yup i like it !


----------



## Iron58p

Today i've put my TS JTL6AH6WA on my LDi+
  
 Strapped on 2-7 pins.
  
 Sound in different mode from Others tube listened before, bass are present well, very deep soundstage, vocal a little bit warm and "cottoned ", but i feel hights not very clean and detailed.
 But i love this tube, after burn in can change something ; i can listen for hours without feel fatigue.
  
 For my modest opinion, i prefer Sylavania 5915 strapped today for the first time to 1-7 pins.
 Great soundstage, great hights and transparency.


----------



## gibosi

Received two pairs of GE 6HM5/6HA5 today. These tubes require no strapping of any kind. Simply set up the LD for EF95 tubes, plug them in and play. Both GEs indicate that they were made in Great Britain, but only one pair has Philips tube codes. The tube on the right was manufactured by Mullard while the one on the left has no markings of any kind. The internal construction of these tubes is also very different.
  

  
 Comparing the construction of the RCA/Siemens and the GE/Mullard, with the exception of the glass envelope, they are quite similar. And since they were both manufactured by Philips, this is not all that surprising. If anything, I am a little surprised that they don't look identical. Hope to spend some time over the weekend with these tubes....


----------



## gibosi

A quick update....  The RCA/Siemens 6HM5/6HA5  are not recommended. The soundstage is noticeably narrow, the bass is lacking and music sounds congested. They have more than 15 hours on them and I just don't think they are going to get significantly better. It is almost as if the short squat tube doesn't provide enough head room. lol  
  
 Surprisingly, the GE/Mullard sounds entirely different, and much better, as does the other Great Britain made, but not by Mullard, GE. The two GEs need considerably more burning-in before I can say anything definitive, but straight out of the box, both sound pretty good to my ears.


----------



## Acapella11

> Quote:
> 
> 
> mordy said:
> ...


 
  
 Thanks Mordy and Audiofanboy for your work describing the sound of your power tubes.
  
 Long time back, I mentioned a surprise, I would come up with. And then nothing happened, lol. OK, now here it comes. I got myself a pair of Reflektor 6H30P-DR from 1983 and I considered a review since a while back but as you could tell from the frequency of postings, I haven't had time for it.
  
 I thought, I put it all neatly together. Of course, this will give a huge post but it will prevent you with the need to go back in the thread.
  
 Mostly, I focused on the differences between 6N6P-IR and 6H30P-DR but I also included my Sovtek 6H30P-EV and 6N6P gold grid tubes at least briefly.
  

6N6P Gold Grid, Novosibirsk - new (April 1995)
 

  
These power tubes provide a very pleasant signature. Gentle treble, sweet mid range but slightly mushy bass.
 
 
Sovtek 6H30P-EV (November 2011)
 

  
 
More transparency, more spacious than the 6N6P. In a classical concert the perception of room for example is better. There is more treble sparkle. The tube sounds overall more energetic. In a Verdi requiem Dies Irae, the kettle drum hits harder, punchier and reverb of the membrane is more apparent. This tube is definitely an upgrade over the 6N6P.
 
6N6P-IR, Novosibirsk - old (April 1974, side stamp says August)
 

  
 
6N6P-IR: Stage and ambience are the words peppered with lots of fine details. In the classical concert, the room now becomes more a hall in terms of depth. The signature is a bit warmer than the 6H30P-EV.  The sound is not as energetic as the 6H30P-EV but more fine and detailed. The 6H30P-EV sounds “louder” but the 6N6P-IR more “real”.
 
6H30P-DR, Reflektor (March 1983) / 6N6P-IR
 

  
The king of the power tube price tag shows features of the 6H30P-EV sound: energetic, punchy and to some extend forward and on the brighter side. In comparison, the 6N6P-family has a warmer, “tubier” signature.
 
What do you get coming from a 6H30P-EV?
The DR sounds warmer, more natural than EV. The stage is particularly deeper and but also a bit wider. The ambience presentation is much better, i.e. the room around the performer has more presence. For example, a classical orchestra is more laid out in front of you. What about treble and bass? How are the mids? All these are more refined and natural. The signature acquires 6N6P-features but keeps the 6H30P framework. Now, many people would be satisfied and end the discussion but the greatest improvement is that you enter a more holographic music experience. The DR is definitely more musical and detailed. This may sound a bit stiff now, but I can imagine this as the transition from simple mid/treble/bass -based listening appreciation to the entry into high-end sound.  
 
Now comes the 6N6P-IR: The stage becomes greater, who would have thought that? An amazing space is laid out in front of you. But the 6N6P-IR plays more with the 6N6P traits only on a totally different level as compared to the 6N6P (I have). Compared to the 6N30P-DR, the signature is warmer, the treble is more refined – the music comes across gentler. The DR throws more treble presence and overall a greater dynamic experience at you. This is particularly good for the harder kind of sounds, for example electric guitar riffs, which appear crunchy as crisps. The DR just eats power.
 
Let me picture you an example of how the stage is rendered differently between EV, DR and IR: In the Verdi Requiem Dias irae, trumpets play in the front and back of this huge venue in my recording. With the 6H30-EVs, you _think_ the back trumpets sound further away, with the DRs you get a much better spatial resolution, the impression of the room is more apparent and the trumpets _sound_ actually_ like_ they are further away. With the 6N6P-IRs, the trumpets sound not as metallic as with the 6N30P-family, but, they now actually do sound _properly placed_ in the back. You can _feel_ them pushed back as compared to other instruments and the room is most delicately resolved.
How come the IR renders more space? This is probably due to the fact that it sounds wetter as compared to the DRs. In Cold Rain, you can hear the high hats echoing more in the room and having a longer decay than with any of the other tubes.
 
In terms of bass, the DR and IR are very articulate, the IR is more biased towards deep bass and plays it of course wetter as well, which gives bass drum strokes more volume. The DR plays more the punchy and crisp mid bass, powerful - again. Mind you, these are relative differences. Both have slightly different styles.
The DR treble is really immediate, extended and on the brighter side, more refined than the EV though and feels well balanced. As mentioned, guitars sound very crisp with either but more natural and real with the DR. The IR plays it a different way, not as pronounced but delicate, still well balanced.
 
The DR has a very appealing and direct transparency, the IR plays (even) more holographic but gentler and more seductive with female voices for example. You could almost say that the IR is the “heptode of the power tubes” and the DR resembles rather a TS 6485 (6AH6). The 6H30P-DR brings the 6H30P sound in perfection. The 6N6P-IR follows the traits of the 6N6P but is really a whole world better. Now, the IR is enormous value for the money and although the EV is an upgrade from the classic 6N6P, the IR beats it easily. The big ranking question: Is the DR the ultimate choice? Maybe 
	

	
	
		
		

		
			





. Its power and detail richness are great. If this is your main focus, please tempt yourself in buying a pair. If you want to feel even more stage finely created before you, then the IR will make you very happy and (even) the DR won’t give you that in the same quality. There is a trade off you cannot avoid.
 
Appendix:
 
Driver tube: Raytheon 6BE6W – 1/7 strap
Headphones: Sennheiser HD800
 
I have FLAC files or PCMs from the original discs from files I have listened to during the review. In order to give you the option to listen to the tracks, I have linked youtube files for initial impressions.
 
Classical
Verdi.  Dies irae (http://www.youtube.com/watch?v=MeXR5blDTIk)
Mozart, Sleigh Rides (http://www.youtube.com/watch?v=EWHzu1FJaOk)
 
Jazz
Blues Company, Cold Rain (http://www.youtube.com/watch?v=nU8eBl2h8qg – This does not sound as clean as the original file.)
 
Singer/Songwriter
Mim Grey, Purple Sky (found no good link)
 
Rock / Hard Rock
Brice Springsteen, My Hometown (http://www.youtube.com/watch?v=S4F2VeHQe0Y)
Manowar, King (http://www.youtube.com/watch?v=m49tmKxq8gg – The interesting bit is at the beginning until 1:40)
 
Electronic
Lindsey Stirling, Stars Align (http://www.youtube.com/watch?v=zKSs41Hv2AM)
Blank & Jones / Where You Belong - Poolside House Mix (http://www.youtube.com/watch?v=kRJsDStHZA8)


----------



## gibosi

An udate on the Tung-Sol 6AV6: (And yes, I have been busy! lol )
  

  
 In short, these tubes sound substantially identical to my 1958 GE 6AV6.
  
 As others have pointed out, yes, most 6AV6/6AT6 tubes do sound quite similar to one another. However, if I roll through the GE, Mullard, Lorenz, Telefunken and then RCA, differences in warmth and forwardness are very easy to discern. 
  
 Rolling through the GE, FIVRE, Toshiba and these Tung-Sols, I cannot hear anything substantially different. While I have to assume that these tubes do not sound perfectly identical, any differences that might exist would appear to be very subtle and will likely require extended critical listening and perhaps better ears than mine to parse. For now, I am quite content to say these all sound the same. 
  
 I have recently been using this track to help me distinguish between the the 6AV6:
  
 Lana del Rey - Summertime Sadness (Asadinho Main Vocal Mix)


----------



## Audiofanboy

acapella11 said:


> Thanks Mordy and Audiofanboy for your work describing the sound of your power tubes.
> 
> Long time back, I mentioned a surprise, I would come up with. And then nothing happened, lol. OK, now here it comes. I got myself a pair of Reflektor 6H30P-DR from 1983 and I considered a review since a while back but as you could tell from the frequency of postings, I haven't had time for it.
> 
> ... 
  
 Finally a comparative review of the 6N6P-IR and 6N30P-DR! Great work Acapella!
  
 Beyond being very useful, your review confirms a few of the things I'd been "speculating on" regarding the IR tubes. From everything I had read here, and my own impressions of DR tubes, I pretty much gathered that the 6N6P-IR were a better deal -higher "limits"- than the new production 6H30P tubes, and quite a leap from even the best 6N6P.
  
 But it is interesting to have that fact put into perspective with the DR tubes. "Holographic" and "realistic" are the two words I would usually use to describe the 6N30P-DR; I know that they are musical and detailed as well, but those aren't the first things that come to mind as far as I'm concerned (the "musical" trait take a _solid_ 100 hours to show up actually; it never leaves again though). So the fact the that you use "musical" to qualify the DR compared to other power tubes kind of confirms what I thought about them: that they let the amp breath like no other power tube, basically, and that makes the _whole amp_ musical.
  
 About treble on the DR tubes: I agree that they have very very detailed treble; probably so much so that it would be hard for me to downgrade at this point (you get used to quality lol). I also very much like the dry and perfectly controlled bass on those tubes.
  
 Apparently the 6N6P-IR offer just slightly lower "limits" and an different flavor. It's good to have someone actually confirm that. I'd be curious to hear your impressions a few months down the road, between the DR and IR tubes though; you can really get addicted to the dynamic and ultra-detailed nature of those tubes imo!
  
 I'd also love to hear the same review on a MK IV unit, just out of curiosity.


----------



## foreign

I can't work out what happened but I bought the Hytron tubes and thought they were amazing straight away with no burn in times. But after about 10-15 hours they have gone from being detailed and a great soundstage with deep bass. To veiled and to be honest my least favourite tube ??? Burn in has changed them for the worse. From my initial impression of them I thought these are awesome to now meh! Has anyone else had this happen to them.


----------



## gibosi

foreign said:


> I can't work out what happened but I bought the Hytron tubes and thought they were amazing straight away with no burn in times. But after about 10-15 hours they have gone from being detailed and a great soundstage with deep bass. To veiled and to be honest my least favourite tube ??? Burn in has changed them for the worse. From my initial impression of them I thought these are awesome to now meh! Has anyone else had this happen to them.


 
  
 Which Hytron tubes do you have? But yes, while tubes usually improve after burning in, sometimes they get worse. And in fact, I seem to remember that not that long ago, some members of this forum observed that the Voskhod 6J1P-EV improved after burning in, but then, after 100 or more hours, they changed for the worse. So while not all that common, your experience is not unheard of.


----------



## Audiofanboy

foreign said:


> I can't work out what happened but I bought the Hytron tubes and thought they were amazing straight away with no burn in times. But after about 10-15 hours they have gone from being detailed and a great soundstage with deep bass. To veiled and to be honest my least favourite tube ??? Burn in has changed them for the worse. From my initial impression of them I thought these are awesome to now meh! Has anyone else had this happen to them.


 
  
  


gibosi said:


> Which Hytron tubes do you have? But yes, while tubes usually improve after burning in, sometimes they get worse. And in fact, I seem to remember that not that long ago, some members of this forum observed that the *Voskhod 6J1P-EV improved after burning in, but then, after 100 or more hours, they changed for the worse*. So while not all that common, your experience is not unheard of.


 
  
 Indeed... Some tubes -often not that top tier all in all- just sound better a bit raw just out of the box, and end up too thin, mellow or just bad after 10~120 hours...
  
 Of course, despite the realness of burn-in -especially as far as tubes are concerned- brain burn-in also plays a large part in the process of liking a tube (the new best thing turning into the new standard, you know).
  
 My recent "new best tubes", while still my best native tubes, are pretty much already getting superseded by my freak experiment with a flying 12AT7 tube (true story). So, nothing surprises me at this point...


----------



## foreign

audiofanboy said:


> Indeed... Some tubes -often not that top tier all in all- just sound better a bit raw just out of the box, and end up too thin, mellow or just bad after 10~120 hours...
> 
> Of course, despite the realness of burn-in -especially as far as tubes are concerned- brain burn-in also plays a large part in the process of liking a tube (the new best thing turning into the new standard, you know).
> 
> My recent "new best tubes", while still my best native tubes, are pretty much already getting superseded by my freak experiment with a flying 12AT7 tube (true story). So, nothing surprises me at this point...



Actually that is really true I initially didn't like the voskod tubes but after changing the Hytron jhy 6ak5 yesterday to the voskod the sound only after about 6-8hrs burn in is great. I kept reading where people gave good reviews of the voskod and I just couldn't understand why. But now they really have opened up and impact and detail has improved and now the good reviews given match sonically to what I am hearing.


----------



## foreign

I initially didn't think that burning in tubes would make a huge difference maybe a slight change but boy was I wrong. With the senns hd650 any change is picked up quite quickly and very noticeable.


----------



## Edgard Varese

foreign said:


> Actually that is really true I initially didn't like the voskod tubes but after changing the Hytron jhy 6ak5 yesterday to the voskod the sound only after about 6-8hrs burn in is great. I kept reading where people gave good reviews of the voskod and I just couldn't understand why. But now they really have opened up and impact and detail has improved and now the good reviews given match sonically to what I am hearing.


 
  
 I still haven't got to the point of liking the Voskhods very much yet, but they have fallen very far behind the tube rotation and I haven't heard them recently.  I just popped in RCA 6DT6As last night - very impressed out of the box - but I want to live with these for a week or so.  I still have IBM heptodes I haven't gotten to yet!


----------



## foreign

I'm trying the mullards next once they arrive that is


----------



## TrollDragon

One of the two 6AH6WA's glows quite a bit brighter than the other one and I don't notice any difference in sound.
 Upon examining the tubes it appears that the brighter one's filament stick's up a little above the mica making it look brighter.
  
 Any unforeseen problems with this? Or nothing to worry about?

 Sorry for the bad phone shot.
 Thanks!


----------



## TrollDragon

Meine Switchen's have arrived... I am going to install these in the back panel of my LD to allow for easy strapping changes. (While powered off of course.)


 I'll get circuit board pictures with this install.


----------



## gibosi

trolldragon said:


> One of the two 6AH6WA's glows quite a bit brighter than the other one and I don't notice any difference in sound.
> Upon examining the tubes it appears that the brighter one's filament stick's up a little above the mica making it look brighter.
> 
> Any unforeseen problems with this? Or nothing to worry about?


 
  
 Nothing to worry about. This is rather common for exactly the reason you noticed. There are often small differences in the internal construction that result in the filament being a little more visible on some tubes. As long as everything else is fine, it is of no real consequence.


----------



## TrollDragon

Thank you good sir!
I was worried about having to contact the seller after I had soldered the strap on the pins.


----------



## Audiofanboy

trolldragon said:


> Meine Switchen's have arrived... I am going to install these in the back panel of my LD to allow for easy strapping changes. (While powered off of course.)
> 
> *I'll get circuit board pictures with this install.*


 
  
 When you do manage to get the PCB out, any chance you could take closeups of the circuitry next to the driver tubes? Like detailed pics of the area with all those resistors and gain switches? I've been trying to figure how the amp biases the driver tubes depending on the gain switches (like, actual values), but it's kind of hard to know without actually looking...


----------



## TrollDragon

audiofanboy said:


> When you do manage to get the PCB out, any chance you could take closeups of the circuitry next to the driver tubes? Like detailed pics of the area with all those resistors and gain switches? I've been trying to figure how the amp biases the driver tubes depending on the gain switches (like, actual values), but it's kind of hard to know without actually looking...


 
  
 I will indeed do that!
  
 I was also pondering the possibility of creating a schematic it when I had the board out as well, but I'll have to see how dense or complicated the routing is. It would be nice to have a schematic done up in a cad program, if not for modifying purposes it would just be interesting to have and I doubt LD would give us one.


----------



## Audiofanboy

trolldragon said:


> I will indeed do that!
> 
> I was also pondering the possibility of creating a schematic it when I had the board out as well, but I'll have to see how dense or complicated the routing is. It would be nice to have a schematic done up in a cad program, if not for modifying purposes it would just be interesting to have and I doubt LD would give us one.


 
 Haha, I'm way out of confort zone as it is, looking at the MK III & IV's PCB and speculating on how this Schiit works, so I probably wouldn't know what to do with schematics lol!
  
 I'm just trying to -purely empirically- figure out how the driver tube are "biased" depending on each gain setting, hence my need to figure out those resistor values (the four resistors next to the DIP switches). All the PCB pics I've found never allow me to 100% identify the color coding on those resistors. And no colors, no values...


----------



## TrollDragon

Today good sir, you shall have your values!


----------



## Audiofanboy

Nice!
  
 After spending a few hours squinting my eyes at small crappy jpeg pics of both the MK III & IV circuit boards, I'm pretty sure that one of the grid resistor values is 470k ohms.
  
 For the three other resistors (I'm assuming 4 gain settings since 4 resistors next to DIP switch, but perhaps I am too stupid to actually understand what is going on there), I seemed to have found 120 ohms, 130 ohms and and an other crazy value.
  
 But from other readings, logic and my best guess at actual colors, I think at least two of these resistors are 120k ohms and 130k ohms (the 470k is the largest resistor on the MK IV pics, so other resistors should/could be smaller in value). The last resistor could/might between those values.
  
 "_What do you need this for? What is this stuff? Why are you bothering us with this crap???_" I'm not sure yet, but I'm trying to find the relevant parameters and their values to know whether or not a new tube type will be "biased correctly" in our LD amps, so we can aim at tubes that might actually sound good, and not waste money on tubes that obviously won't play well with in those circuits.


----------



## mordy

Hi AFB,
  
 Very impressive work on the "Flying 12AT7' tube! In concept, what is the advantage of using one tube instead of the two halves of the 12AT7? Below is a picture of an adapter that conceptually could be  made to fit the LD MKIII to use 12AT7 tubes etc:
  




  
 Everything would have to be in the reverse, with the wider part fitting into the two sockets on the LD with pins facing down. The top part would have the pin socket for the single tube. I am sure that there would be Chinese companies interested in making it if there was a demand. But, what is the gain of using one tube? More purity of sound?
  
 The second thought is that the new Little Dot MK9 is a three tube amp, but with very different tube complement.
  




 How would a 12AT7 modded LDIII compare to a LD MK9?
  
 A quick sweep of Ebay shows many bargains to be had in all these tube types, 12AT7, and for the MK9 6N9P and 6080 tubes; some even in the 99c stores.
  
 My question now, however, is that I am very happy with the 6N6P-IR/6DT6-6AV6 combination. Would further modding of the MKIII yield greater sonic results? Would the MK9 sound appreciably better?


----------



## mordy

Hi AFB,
  
 Why don't you ask the designer of the MKIII/MKIV directly about the resistor values? His name is Sword Yang and the email address is :    little.tube@gmail.com


----------



## Audiofanboy

mordy said:


> Hi AFB,
> 
> Why don't you ask the designer of the MKIII/MKIV directly about the resistor values? His name is Sword Yang and the email address is :    little.tube@gmail.com


 
  
 I did 
  
 Just waiting for the answer now!
  
 About using one tube instead of two on the MK III / IV : imo, it would be a great solution, _theoretically_. One problem is purely on an esthetic level, and the other one on a practical level.
  
 I'm pretty sure we could work out somekind of an adapter to use one 12Ax7 (x = T / U / X...) on a Mk III, and not have it look too ugly. But it would still be cumbersome to have a single tube kind of floating there with a lot of hidden cabling to reroute the pins to the right sockets. On the MK IV, this kind of an adapter would just look downright ugly...
  
 On the other hand -and for a small amount of extra $- a pair of 12Ax7 could be fairly easily adapted on _each_ channel and socket and both look _OK_ or _decent_, and also be a bit more practical to handle. The added bonus is that a center-tapped 12V double triode could be used with only one heater and triode section powered, and be both economical power-wise and also leave a brand new triode section for the future. Not that bad of an idea, if we look at it long term.
  
 However, the other double triode I've been investigating, the 6922/6DJ8/ECC88 supposedly "better" and/or "more linear", does not behave like that at all. It is a 6V, _not_ center-tappable tube, meaning that both triode sections are always powered regardless of use.
  
 I've actually just bought 6 very nice EI "Yugoslavia" ECC88 tubes, made on Philips gear with the sought after Philips/Amperex "A-frame" getters, that I will be testing when I get them. I intend to eventually test those on separate 9-pin sockets -attached to 7-pin adapters for convenience- but I might also try them as actual double triodes for both channels.
  
 So the problem I am going to bump into here, is that unused-yet-heated triode section for each channel... Note that legend would have it that the two triodes in each tube could _somehow_ be paralleled, but I suspect that that would be for very different amp schematics. Also note that this is why I want to have those resistor values; these tubes could possibly put out 5 times their rated plate current -and dissipation- if biased like 6AK5 might be in our amps, so _for once_, I'm trying to check things out before hand. they seem to like 90V of plate voltage; our usual tubes are closer to 200...
  
 Anyway, just food for thoughts, as usual. I told you I had ideas on the back burner  .


----------



## mordy

Keep them thoughts coming - always fascinating to read about it! Once things shake out I'll be looking for tubes to try, but the stuff you are doing is beyond my abilities....
  
 Good luck, and don't make any fireworks!


----------



## TrollDragon

I have the pictures taken and a rough schematic made of the amp. Give me a few hours to assemble the info into a presentable format. I have some building maintenance to do first.


----------



## Audiofanboy

trolldragon said:


> I have the pictures taken and a rough schematic made of the amp. Give me a few hours to assemble the info into a presentable format. I have some building maintenance to do first.


 




  
 If by any chance you could also get a clear shot of -what I think is- the cathode bias resistor along with the grid bias resistors, as per the pic below, that would just make my day lol. That day might be tomorrow though, as it 11pm where I live...
  

  
 Thanks!


----------



## TrollDragon

Done sir!


----------



## TrollDragon

Well the LD is a real pig to get out and put back in the case with the transformer wires coming down from the top...
  
 Here is a very rough schematic of the Left Channel, the Right Channel would be a mirror copy.

  
 Gain Resistors

  
 Cathode Bias Resistor

 Hope these are OK... 680Ω checked with meter and silkscreen value.


----------



## Audiofanboy

trolldragon said:


> Well the LD is a real pig to get out and put back in the case with the transformer wires coming down from the top...
> 
> Here is a very rough schematic of the Left Channel, the Right Channel would be a mirror copy.
> 
> ...


 
  
 Awesome work TrollDragon! I can't understand half of it, but great work nonetheless lol!
  
 Ok, so the cathode bias resistor is 680 ohms as I thought (I finally found a picture with an angle that kind of allowed me to see the color coding on that resistor late last night, but as usual, it was hard to be sure). So, that one's final and confirmed at least.
  
 Now, looking at your schematics, I'm suddenly reminded that the gain switches are basically feedback switches... Can you actually tell which of the switch settings does what here (what resistors and pathways are used for each gain setting, basically), and whether or not there's a gain setting with no feedback?
  
 Great stuff though! No idea how I'm going to make sense of this and use it to pick tubes, but most useful, especially that cathode bias resistor value.
  
 "_One small step for head-fi, a giant leap for LD users_."
  
 Edit: Nevermind, I think I figured out the gain switches myself. So, if I understand correctly, the only "bias" resistor for the driver tube grid (they call it a "grid stopper" or something right?) is that 10K resistor after the potentiometer?
  
 About the cathode bias resistor: a 6922/6DJ8/E8CC(...) double triode takes that exact value, 680 ohms, as a reference to bias the cathode in each triode section. While it doesn't matter that much, it's a good start. I can't quite figure how to "calculate" a hypothetical grid voltage with the resistor value and input signal though... Then again, I'm not an electrical engineer in the first place; I have to rack my brains to understand this crap...


----------



## TrollDragon

Hey AFB!

Unfortunately my electronics knowledge was learned on the bench repairing audio gear for Radio Shack back in the day. Changing blown outputs in amplifiers and radios, cleaning, aligning and torquing cassette drives. Repair of remote controlled toys etc... No formal training here just a gathered "bench" knowledge. 

I never learned anything at all about tube circuitry and after the repair shop closed I went straight into digital electronic repair for Commodore and Atari, mostly all TTL level gate's.

So I really can't be of any help analyzing the circuitry, I was pointed to a few good books on tube theory from the guys here and I guess its now time to delve into them whole hog... 

I am going to try an do up a better schematic in Digikeys online cad program to straighten out the layout a bit. I had to remove some of the big caps from my board to follow some of the traces. That's why some things are sideways and not in the typical vertical layout.


----------



## Audiofanboy

See, I don't even have the practice part down lol, let alone the theory! I used to _hate_ electronics back in my school days; but with perseverance and the drive for getting better audio, I am starting to understand parts of this. Like your schematics: after staring at it for 2 hours and looking a number of things up, it makes sense to me -for the most part  .
  
 The only symbol/part/thing I don't get is those capital A letters that the anodes are connected to (do pardon me if it's a silly question...). The rest I understand at the basic level.
  
 Now, I just need some kind of software that would allow me to plot tube curves with cathode bias and grid stopper values... Not that I would know how to use such a program... We live and learn, I guess.


----------



## siles1991

any strap recommendations for the RCA 6DT6A's? currently running ef95 no strap but bass a bit boomy


----------



## Audiofanboy

siles1991 said:


> any strap recommendations for the RCA 6DT6A's? currently running ef95 no strap but bass a bit boomy


 
  
 As floating grid 3 on this tube type makes little to no sense, I'd recommend EF92 or EF95 with 2-7 strap. EF95 with 1-7 strap is a possibility too, but I didn't find it held much interest on 6DT6 tubes, so I'd stick with EF92 for sound quality and practicality.


----------



## TrollDragon

audiofanboy said:


> See, I don't even have the practice part down lol, let alone the theory! I used to _hate_ electronics back in my school days; but with perseverance and the drive for getting better audio, I am starting to understand parts of this. Like your schematics: after staring at it for 2 hours and looking a number of things up, it makes sense to me -for the most part  .
> 
> The only symbol/part/thing I don't get is those capital A letters that the anodes are connected to (do pardon me if it's a silly question...). The rest I understand at the basic level.
> 
> Now, I just need some kind of software that would allow me to plot tube curves with cathode bias and grid stopper values... Not that I would know how to use such a program... We live and learn, I guess.


 
  
 Sorry, I should have explained that part, the capital "A"'s are the traces that head off to to the power supply rail section which I made on another page and didn't get uploaded yet.
  
 Have a look at this software here possibly.
http://www.glass-ware.com/GlassWare_Programs.htm


----------



## TrollDragon

Little glass goodies from T.Dot have arrived.
 Time to test out my strapping switches I installed last night.


----------



## Audiofanboy

Curious about those 6CS6, Canadian-made, Japan-made or US GE?


----------



## TrollDragon

audiofanboy said:


> Curious about those 6CS6, Canadian-made, Japan-made or US GE?


 
  
 They just say Canada above the 6CS6 and look exactly like these ones here except mine are PN date code.
http://www.ebay.com/itm/TWO-6CS6-G-E-TUBES-N-O-S-TESTED-/261286212071


----------



## hypnos1

siles1991 said:


> any strap recommendations for the RCA 6DT6A's? currently running ef95 no strap but bass a bit boomy


 
  
  
 Hi siles.
  
 Can certainly endorse AFB's recommendation - EF92 (mine via EF95 6-7 strap). Fabulous sound, and with the volume pot a good few notches down...
  
 Am sure you've already found this out, though!
  
 Happy rolling.


----------



## gibosi

trolldragon said:


> They just say Canada above the 6CS6 and look exactly like these ones here except mine are PN date code.
> http://www.ebay.com/itm/TWO-6CS6-G-E-TUBES-N-O-S-TESTED-/261286212071


 
  
 These resemble RCA 6CS6, and this is not surprising to me, as the Canadian GE 6DT6A and 6AT6 I have also appear and sound RCA-made as well.


----------



## kvtaco17

Quote:


siles1991 said:


> any strap recommendations for the RCA 6DT6A's? currently running ef95 no strap but bass a bit boomy


  
 Quote:


hypnos1 said:


> Hi siles.
> 
> Can certainly endorse AFB's recommendation - EF92 (mine via EF95 6-7 strap). Fabulous sound, and with the volume pot a good few notches down...
> 
> ...


 
  
 EF95 6/7 = more forward and much more controlled bass then unstrapped
 "     " 1/7 = More bass the above, but much more controlled then stock... more laid back and airy
 "     " 2/7 = more similar to 1/7 except less bass impact and slightly more forward.
  
 All good, just depends on what you like.


----------



## gibosi

Made in Great Britain GE 6HM5/6HA5 followup:
  
 GE Made in Great Britain by GE. Date unknown.
  

  
 GE Made in Great Britain by Mullard/Blackburn, 1970 (B0F1)
  

  
 First, both of these are excellent tubes on par with my recent favorites, GE 6AV6, Raytheon 6BE6W and Tung Sol 6DT6, with punchy bass with good articulation and detail, crystal clear and clean highs, and a wide and deep stage. The primary difference between the two GEs is warmth. As one might predict, the Blackburn-made GEs add just a bit of warmth to the upper bass and mid range. Interestingly, the difference in warmth between these two GEs is quite subtle and not as noticeable as between the Mullard/Blackburn and GE 6AV6.
  
 Those of you who have been thinking about trying some triodes, but feeling a bit squeamish about the need to _amputate_ and _mutilate_ perfectly good tubes lol, I encourage you to get a pair of these GE 6HM5/6HA5. They require no strapping or mutilation of any kind. Simply set up the LD for EF95 tubes, plug them in and play.
  
 Also, I have seen Sylvania 6HM5/6HA5 on eBay that appear to have the same internal construction as the GE-made tubes. And further, I recommend you avoid the short, squat 6HM5/6HA5 tubes. 
  
 Recommended.


----------



## kvtaco17

gibosi said:


> Made in Great Britain GE 6HM5/6HA5 followup:
> 
> GE Made in Great Britain by GE. Date unknown.
> 
> ...


 
 How would you compare these VS the 6DT6?


----------



## gibosi

kvtaco17 said:


> How would you compare these VS the 6DT6?


 
  
 I haven't listened to the RCA 6DT6 in awhile (which I understand is your current favorite), so will try to find some time to do a quick comparison in the next day or so.
  
 Cheers


----------



## kvtaco17

gibosi said:


> I haven't listened to the RCA 6DT6 in awhile (which I understand is your current favorite), so will try to find some time to do a quick comparison in the next day or so.
> 
> Cheers


 
 Thank you much! The RCA's and Sylvania's are tied for my favorite lol


----------



## Edgard Varese

siles1991 said:


> any strap recommendations for the RCA 6DT6A's? currently running ef95 no strap but bass a bit boomy


 
  
  
 The switch to EF92 made mine sound much better.  They were a bit sibiliant last night though, but I think it might just have been my pre-existing headache.


----------



## Acapella11

kvtaco17 said:


> EF95 6/7 = more forward and much more controlled bass then unstrapped
> "     " 1/7 = More bass the above, but much more controlled then stock... more laid back and airy
> "     " 2/7 = more similar to 1/7 except less bass impact and slightly more forward.
> 
> All good, just depends on what you like.


 
  
 Agreed kvatco17!
  
 Just received mine today (GE 6DT6A). Which setting do you use Mordy?
 Unstrapped bass is not my blues, 2/7 too forward. I am between 6/7 and 1/7, both work well in different ways.
  


edgard varese said:


> The switch to EF92 made mine sound much better.  They were a bit sibiliant last night though, but I think it might just have been my pre-existing headache.


 
  
 6/7 and 2/7 can be a bit sibilant depending on your music but also nicely energetic. With 1/7 sibilant sounds are reduced.
  
 Also got a pair 10M 6AV6.
  
 Both pairs sound very nice and also very different.


----------



## MIKELAP

This is  Montreal band BEAST very good tune 
 DARK EYES


----------



## gibosi

kvtaco17 said:


> How would you compare these VS the 6DT6?


 
  
 OK... A quick comparison of the GE-made 6HM5/6HA5 and the RCA 6DT6. (Sorry, but I do not have a Sylvania 6DT6. And I think from now on, I will shorten 6HM5/6HA5 to just 6HM5.)
  
 As these are both very good tubes, the differences between them are quite subtle. And since you like the RCA 6DT6, I am quite sure you would also like the GE 6HM5.
  
 The stage on both of these is nice and wide, but the 6HM5 is a bit more 3D. Sounds off in the distance actually sound like they are indeed farther away.
  
 The other primary difference boils down to "house sound." In my experience, the RCA house sound is typically a warm sound with good bass presence. The GE house sound does not have the same degree of added warmth, and at least to my ears, seems a bit more natural. Thus, vocals and upper bass on the RCA 6DT6 are warm and full, whereas, on the GEs, vocals, while still sweet, seem cleaner and more natural to me. And similarly, the bass on the GEs also seems to be a tad bit cleaner, with slightly better detail and articulation. But again, I think these differences are quite subtle, and I find both tubes to be very good. However, my 1958 GE 6AV6s (and clones) are still my go-to tubes.


----------



## Edgard Varese

gibosi said:


> OK... A quick comparison of the GE-made 6HM5/6HA5 and the RCA 6DT6. (Sorry, but I do not have a Sylvania 6DT6. And I think from now on, I will shorten 6HM5/6HA5 to just 6HM5.)
> 
> As these are both very good tubes, the differences between them are quite subtle. And since you like the RCA 6DT6, I am quite sure you would also like the GE 6HM5.
> 
> ...


 
  
  
 It's interesting that you mention this as I have been thinking about trying a tube that is a bit more "holographic" seeming.  I should get a couple of the 6HM5s...


----------



## MIKELAP

Like you say gibosi those 6AV6 are hard to beet was listening to some RCA 6DT6A still prefer the 6AV6 in this case G.E. JAN 6AV6 they sound cleaner.


----------



## mordy

Hi A11,
  
 "Just received mine today (GE 6DT6A). Which setting do you use Mordy?"
  
 Started out with the EF95 1/7, but now I use EF92 NS, and I am happy with this ( but I liked the 1/7 setting as well) . My 6DTA6 tubes in use at this time are Japanese made, either by Hitachi or Toshiba and perhaps they come from the same factory as the (demystified?) Siemens Foreign and Haltron tubes.
  
 I will try to post pictures later of these three tubes, but right now I am away from home for a few days.
  
 PS: IMHO the 6DT6 tubes require 30-50 hours burn in to enter their prime.


----------



## TrollDragon

Well the switches are installed, one for each side to do 1-7 / NS / 2-7 and for me this way is quite a lot easier than strapping in the socket.

  
 Nothing is ever done without incident though...
 With everything put back together, I popped in the 6DT6A's set the switches for the 1-7 strap and turned on the LD.
 Played Dire Straits "Brothers In Arms" 20th Anniversary Edition in 24/96, "Money for Nothing" will raise goosebumps on your goosebumps!
  
 So I figured lets try 2-7, I shut off the LD and flipped the switches. One of the 6DT6A's looked a little crooked, I straightened it and turned on the LD. Well all I was presented with was HUM, independent of the volume control this HUM was there and changed pitch when you brought your hand near the chassis.
  
 Well didn't the panic set in, the switches are bad, the switch wire is picking up HUM, these new tubes are bad? So I powered off, changed to the 6CS6's and upon turning the power back on the HUM was back... Panic turning into annoyance at wrecking my LD and I am going to have to take it apart to see what fried, but there was no smell...
  
 Anyway to make a long story short the top front right screw that holds the circuit board to the chassis was loose, this screw provides the ground between the chassis and the board. I had put it in first without tightening it so I could line up the other standoffs with the holes.
  
 If you ever have the board out of the LD, make sure the top front right screw is tight upon reassembly. Once I screwed it down and powered up the LD again, the HUM was completely gone and let me tell you what a huge relief that was.


----------



## Audiofanboy

trolldragon said:


> Well the switches are installed, one for each side to do 1-7 / NS / 2-7 and for me this way is quite a lot easier than strapping in the socket.
> 
> Nothing is ever done without incident though...
> With everything put back together, I popped in the 6DT6A's set the switches for the 1-7 strap and turned on the LD.
> ...


 
  
 Speaking of grounding, my next experiment involves using a double triode for each -single- channel, meaning that only one triode section would be used, with the other section just "floating" but heated. I know that can't be very good over the long term...
  
 So, I believe I should be grounding that unused triode section to avoid problems. Do you have any suggestions as to how I could do that easily (like wire those pins straight to the chassis or something)?


----------



## Audiofanboy

Ok, more tube silliness for anyone who's still interested. This time, no electrical theory, all DIYP (do it yourself poorly) practice!
  
 I'd said I got a single 12AT7 tube to work for both channels (two triodes in the tube, one used per channel, ugly and risky mod), and that my next attempt would be to -cleanly- adapt a 6DJ8/ECC88 (thereafter ECC88, since that's what I used) to each channel, therefore only running one triode out the two in each tube. Not particularly hard or risky compared to my previous "mod" definitely prettier, less impressive, but more logical for long term use.
  
 I got my EI "made in Yugoslavia" ECC88 tubes in the mail 24h after ordering them (for once, they shipped from close to me, so I didn't have to wait the usual whole week). Why wait any longer to test them? So, I immediately processed to adapt some socket adapters to an idea that had popped into my head yesterday, looking at tube datasheets, and mapping out which ECC88 pin would have to go to which B7G socket hole to use either triode 1 or triode 2 of the tube.
  
 But first off, how funny/interesting/odd is it to have driver tubes from (ex-)Yugoslavia lol? Apologies for anyone from the Balkans region, but when I think of current Serbia, my first thought isn't about high-tech gear... Still, those are very fine tubes, evidently made on Philips factory lines, but in the EI Nis factory in ex-Yugoslavia. Date coded with a 9, meaning made in 1979 or 1989, before or after is unlikely (I don't believe they had Philips lines in '69, the country was kind of at war by '92, and I think those "A-frame" Philips getters were from later times, i.e., not the 50's or 60's). These are supposed to basically be Philips copies with similar high quality sound, but slightly lesser craftsmanship. They look solid at any rate!
  
 When I mapped out how to use either triode in those tubes on our sockets, I realized that there was a way we could just fit these tubes in -an adapter not the native sockets- with very little modification.
  
 Using ECC88 triode 2 meant mapping (ECC88 to 6AK5):
 - pin 1 to pin 5
 - pin 2 to pin 1
 - pin 3 to pin 2
 - pin 4 to pin 3 (or 4)
 - pin 5 to pin 4 (or 3)
  
 If you look at your socket holes, you'd quickly see that this would require a major adapter with wires between pins far apart; not easy.
  
 On the other hand, mapping triode 1:
 - pin 4 to pin 3 (or 4)
 - pin 5 to pin 4 (or 3)
 - pin 6 to pin 5
 - pin 7 to pin 1
 - pin 8 to pin 2
  
 OK, so the pattern doesn't immediately strike you as obvious, I get it. But look at it this way: for pure triode use, pins/holes 6 and 7 don't serve any purpose in our amps (nothing needs to go to those holes at the socket level), so as long as socket hole 6 and 7 stay empty, you can use pins 6 and 7 on an adapter to do whatever you want. So, let's map those pins again, shall we:
 - pin 4 to pin 3 (or 4)
 - pin 5 to pin 4 (or 3)
 - pin 6 to pin 5
 - pin 7 to *pin 6* (attached to pin 1)
 - pin 8 to *pin 7* (attached to pin 2)
  
 Can you see where I'm going with this? Essentially, I realized that you can plug the five relevant pins of a ECC88 in a sequence of five consecutive holes on a 7-pin adapter; provided that you disconnect pins 6 and 7, and reroute pin 6 to pin 1, and pin 7 to pin 2.
  
 And that's what I did, basically. I opened up a pair of my 7-pin adapters/savers, bent pins 6 and 7 inside the adapter (the pin are like 5cm long inside, so bending them allows the pins to not poke out of the adapter, and allows them to get close to the pins they need to be connected to), and soldered pin 6 to pin 1, and pin 7 to pin 2. Easy.
  
 If you just couldn't be bothered or hate soldering, you could just get a pair of adapters, chop off pins 6 and 7, and manually strap pin 6 to 1 and 7 to 2 with the usual wire mod.
  
 Next, with those adapters prepped up, you just have to manhandle the ECC88 tubes to fit in those 5 relevant pins in the 5 consecutive relevant holes (which would probably require you to bend the four left over pins on the tube, unless you have really small adapters). Look at the pics in full size if you want to get a better picture of what I mean.
  
 And this is what you get; not too bad I'd say? Definitely prettier than the floating 12AT7 mod!
  

  

  

  
 As per usual, it worked like a charm, even on the first try! Listening to the amp for a few minutes tells me that these are fine tubes, but I'll allow myself a few hours of burn-in before I give impressions. The purpose of this mod was to show that ECC88 type tubes can be made to work in each channel and not look too ugly; and I think that's goal's been reached!
  
 Anybody else interested in joining me in double triode land lol?
  
 Now, I just need to solve the floating triode issue (ground the heated yet unused triode)...


----------



## TrollDragon

audiofanboy said:


> Speaking of grounding, my next experiment involves using a double triode for each -single- channel, meaning that only one triode section would be used, with the other section just "floating" but heated. I know that can't be very good over the long term...
> 
> So, I believe I should be grounding that unused triode section to avoid problems. Do you have any suggestions as to how I could do that easily (like wire those pins straight to the chassis or something)?


 
 I asked that question over at "I <3 Tube Amps" and got my arse chewed on hard by the pros there... 
 Lucky to make it out of there unscathed, but I did manage to get some info from the guru's while running away in sheer terror. 
	

	
	
		
		

		
		
	


	



  
 Two of them suggested to run both halves of the tube in parallel as opposed to floating or grounded.
  
 Quote: I <3 Tube Amps 





> But IN GENERAL when paralleling triodes, the plate resistors, cathode resistors and grid stoppers get halved, an any cathode bypass caps get doubled.
> So it might just not be feasible with out amp modifications...


 
  
 Ponder it over and see what you think...


----------



## Audiofanboy

trolldragon said:


> I asked that question over at "I <3 Tube Amps" and got my arse chewed on hard by the pros there...
> Lucky to make it out of there unscathed, but I did manage to get some info from the guru's while running away in sheer terror.
> 
> 
> ...


 
  
 Lol, yeah, the internet can be a dangerous place to hang out (just look at the other threads here!).
  
 I'd read that one of the options to use a double triode in a single channel gain stage is to parallel both triodes, but everywhere I looked, I saw that this would probably mean some degree of parts to change or adapt to work well (people suggest two separate grid stoppers for example). Besides, it's not like we need the extra current that would come from double dipping triodes. It's extra gain I'd like!
  
 For a 12Ax7 tube, this isn't really a problem, since one side of the tube can be used with the other triode unpowered -unheated. On a ECC88, that's not possible. Apparently, the heated but idle triode would eventually get "cathode poisoning" from such a use over time (years, mind you), meaning that it wouldn't work well the day you decide to use it. Not that it matters, since it's easy to just use another tube altogether when the first triode starts to show signs of fatigue.
  
 The real potential problem is just this floating triode... Which really should be grounded. Then again, I haven't seen or heard anything bad in my amp for the last 2 hours, so it is unlikely to be a huge issue. And I know that some -professional- amps use only one half of a double triode (with the other half grounded, obviously).


----------



## gibosi

audiofanboy said:


> Next, with those adapters prepped up, you just have to manhandle the ECC88 tubes to fit in those 5 relevant pins in the 5 consecutive relevant holes (which would probably require you to bend the four left over pins on the tube, unless you have really small adapters). Look at the pics in full size if you want to get a better picture of what I mean.
> 
> .......
> 
> Now, I just need to solve the floating triode issue (ground the heated yet unused triode)...


 
  
 Now that we know that the top front right screw on the LD IV is chassis ground, it should be possible, but perhaps a bit ugly, to assemble a wiring harness to connect the unused triode pins to that screw. Or otherwise, it might be just as well to cut off the four pins connected to the unused triode in the same manner as we cut off the pins connected to the unused diodes in the 6AV6.


----------



## Audiofanboy

gibosi said:


> Now that we know that the top front right screw on the LD IV is chassis ground, it should be possible, but perhaps a bit ugly, to assemble a wiring harness to connect the unused triode pins to that screw. Or otherwise, it might be just as well to cut off the four pins connected to the unused triode in the same manner as we cut off the pins connected to the unused diodes in the 6AV6.


 
  
 See, this is where I don't know which option to choose...
  
 I guess depending on how well the ECC88 tubes work with a floated triode, I'll gauge whether or not it's worth bothering with an -ultimately ugly- grounding solution or just chopping those pins off neatly and be done with the problem.
  
 I do recall reading that regardless of grounding, all the unused pins (triode + shield) should be tied together. It would probably be good to ground them in such a scenario, or at least ground the shield separating the triodes...?


----------



## TrollDragon

Something like this might work, this one is backwards but they stock the 9 to 7 pin as well.

http://electrojumble.org/Valves_etc.htm Second item at the bottom of the page.
  
 Another suggestion was to strap the second triode as a cathode follower.
http://www.tubecad.com/october99/page4.html


----------



## Oskari

audiofanboy said:


> See, this is where I don't know which option to choose...


 
  
 Here's an idea for you:


----------



## siles1991

Guy's I cant reach my jumpers...is tehre another way to put the RCA 6DT6A's into EF95 mode?


----------



## gibosi

siles1991 said:


> Guy's I cant reach my jumpers...is tehre another way to put the RCA 6DT6A's into EF95 mode?


 
  
 As I recall, you have a MKIV SE...  On my LD 1+, I remove four screws and take the bottom panel off to gain access to the jumpers. But I am not sure how this is done on your amp.


----------



## kvtaco17

oskari said:


> Here's an idea for you:


 
 Images of South Parks "humancentipad" episode come to mind... humancentitube... lol


----------



## MIKELAP

siles1991 said:


> Guy's I cant reach my jumpers...is tehre another way to put the RCA 6DT6A's into EF95 mode?


 
 When jumpers are on EF92 setting on amp put in adaptor and your EF95 tube in adaptor

  
 http://www.ebay.com/itm/300961753333?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1438.l2649


----------



## TrollDragon

siles1991 said:


> Guy's I cant reach my jumpers...is tehre another way to put the RCA 6DT6A's into EF95 mode?


 
 You will have to remove the jumpers to switch it into EF95 mode or cut off pin 7 on the 6DT6A but that would not be a good choice.
  
 Find some long tweezers or a pair of hemostat's and pull the jumpers off.
  
 Then PM me your mailing address and I'll mail you some long jumpers that are easier to get a hold of.


----------



## MIKELAP

trolldragon said:


> You will have to remove the jumpers to switch it into EF95 mode or cut off pin 7 on the 6DT6A but that would not be a good choice.
> 
> Find some long tweezers or a pair of hemostat's and pull the jumpers off.
> 
> Then PM me your mailing address and I'll mail you some long jumpers that are easier to get a hold of.


 
  
 Where do you buy those long jumpers and what would be the size of those 2.54 M M maybe and whats the total lenght about . Thanks


----------



## Iron58p

How the tubes were made : i have found two old videos.
  
 It's incredible what hard work is.
  
 I have loved in special mode video number 2.
  
 Enjoy 
	

	
	
		
		

		
		
	


	



  
http://www.youtube.com/watch?v=hUSouYNvsMA
  
http://www.youtube.com/watch?v=fxXrfU36aY8


----------



## TrollDragon

mikelap said:


> Where do you buy those long jumpers and what would be the size of those 2.54 M M maybe and whats the total lenght about . Thanks


 
 They are for 2.5mm pin spacing and the jumper are 13.5mm in length.
  
 I've collected a few from computer service over the years, but you could probably get a handful from a mom & pop type computer repair shop near you, they would probably have a bucket full of them lying around.
  
 If not then eBay sells them as well.
 http://www.ebay.ca/sch/i.html?_from=R40&_sacat=0&_nkw=jumper+cap+handle&_sop=7


----------



## TrollDragon

GE 6DT6A's & CGE 6CS6's are in the house with the 6DT6A's in 1-7 mode for a bit.
 
  
 \And the led lit up version's...


----------



## siles1991

any place to find cheap socket savers to convert to adapters?


----------



## siles1991

trolldragon said:


> You will have to remove the jumpers to switch it into EF95 mode or cut off pin 7 on the 6DT6A but that would not be a good choice.
> 
> Find some long tweezers or a pair of hemostat's and pull the jumpers off.
> 
> Then PM me your mailing address and I'll mail you some long jumpers that are easier to get a hold of.


thanks for the offer but I've decided to just use 6/7 ef95. I live in Malaysia so shipping expensive


----------



## Iron58p

gibosi said:


> Made in Great Britain GE 6HM5/6HA5 followup:
> 
> GE Made in Great Britain by GE. Date unknown.
> 
> ...


 
  
 Bought a pair of this cheap tubes.
  
 Seller write "with Philips/Mullard tube codes".
 I'm not sure, but seems have the same construction of GE Made in Great Britain by Mullard/Blackburn of Gibosi.
  
 Can be the same ?
  
http://www.ebay.it/itm/300879467071?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649


----------



## gibosi

iron58p said:


> Bought a pair of this cheap tubes.
> 
> Seller write "with Philips/Mullard tube codes".
> I'm not sure, but seems have the same construction of GE Made in Great Britain by Mullard/Blackburn of Gibosi.
> ...


 
  
 Yes, I saw those. They have the same plates, getter splash and Mullard tube codes, so I am pretty sure they are the same.


----------



## TrollDragon

audiofanboy said:


> Anybody else interested in joining me in double triode land lol?
> 
> Now, I just need to solve the floating triode issue (ground the heated yet unused triode)...


 
 Yes I would, but I'd have to gather the parts...
  
 More information given to me  from I <3 Tube Amps:


> I suggest measuring the plate voltage. If it is higher than 3/4 of B+ then it suggests the existing passives are a better match to the two sections in parallel than one on its own.


 
 Measure the plate & B+ voltages and see, then you could just parallel the triodes in the adapter socket without changing anything on the board.


----------



## siles1991

Planning to try to DIY socket savers for 7 pins anywhere I can start at? I can't seem to find any 7 pin socket savers after searching on google.


----------



## Audiofanboy

trolldragon said:


> Yes I would, but I'd have to gather the parts...
> 
> More information given to me  from I <3 Tube Amps:
> Measure the plate & B+ voltages and see, then you could just parallel the triodes in the adapter socket without changing anything on the board.


 
  
_Ach so_.
  
 I'm not even sure I would know how to measure those voltages though... At least no safely lol.
  
 I'm pretty sure the board would be more suited for using just one triode, as it has a cathode bias with the exact value mentioned in the ECC88 datasheets. Not to mention that paralleled ECC88 sections could go up to 60mA of plate current, instead of ~10mA values usually... Gain would still be low to medium however.
  
 I need someone with more skills (and tools) than me to test this lol!


----------



## TrollDragon

audiofanboy said:


> _Ach so_.
> 
> I'm not even sure I would know how to measure those voltages though... At least no safely lol.
> 
> ...


 
  
 The best thing then would be to just let the other triode float unless is caused hum, then a ground would be needed. The ones with a center tapped heater would be better as well IMHO as the other triode would stay cold.


----------



## gibosi

trolldragon said:


> The best thing then would be to just let the other triode float unless is caused hum, then a ground would be needed. The ones with a center tapped heater would be better as well IMHO as the other triode would stay cold.


 
  
 What about Oskari's suggestion of using only one dual triode tube, installed in one socket, and connecting the second triode to a socket saver plugged into the other socket? This would leave only the shield floating.
  
 http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/3060#post_9831134


----------



## Audiofanboy

gibosi said:


> What about Oskari's suggestion of using only one dual triode tube, installed in one socket, and connecting the second triode to a socket saver plugged into the other socket? This would leave only the shield floating.
> 
> http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/3060#post_9831134


 
  
 Very true; that was actually my original idea and starting point with that floating 12AT7 tube (but at that time, I was just in a hurry to get my concept tested). But then, I got to think about how a one-tube solution would look. And invariably, a single tube for both channels solution would always be somewhere on the ugly-weird continuum (UWC for short).
  
 Basically, it would either look weird (one tube in one socket, other socket empty), or ugly (tube floating in between sockets or on a large adapter between sockets).
  
 Still, if someone wants to give it a try, I say go for it. It's actually pretty easy to adapt these tubes, once you get the pin layout in your head!


----------



## Audiofanboy

trolldragon said:


> The best thing then would be to just let the other triode float unless is caused hum, then a ground would be needed. The ones with a center tapped heater would be better as well IMHO as the other triode would stay cold.


 
  
 Definitely a better idea over the long term (_and_ you get that free NOS triode after a few years when the first one weakens, not a leftover "poisoned" triode). I'll actually give that a whirl when I'm done with this ECC88 test.
  
 Besides, that one 12Ax7 tube I tested, even plugged with lengths of Schiity aluminum cables, actually sounded pretty good. And these tubes could be interesting to use in parallel too. A 12AX7 has very high mu but low gm, so a paralleled 12AX7 would still have the same mu, but -supposedly- more gm and less noise (but more "Miller capacitance" or something, don't ask, I'm doing my best here).
  
 Again, lads, let's get this stuff tested! A few different shops -in the US- that sell fairly cheap adapters/testers have been mentioned in this thread. All this stuff requires is a pair of adapters (or a DIY adapter made with a chopped up tube base) and some tubes.


----------



## TrollDragon

gibosi said:


> What about Oskari's suggestion of using only one dual triode tube, installed in one socket, and connecting the second triode to a socket saver plugged into the other socket? This would leave only the shield floating.
> 
> http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/3060#post_9831134


 
  
 If it could be made nicely it would be great but unsymmetrical... I can see a big pile O'Ugly with a wire jumping across.
  
 I'd rather see an adapter rig where those with a MK II or MK III could plug it right in and those of us with a a MK IV just have to loosen the rings and spin them to the side for installation. 

 B7G plugs on the bottom, B9A socket in the middle on a circuit board that runs across both plugs.
 Could be covered in shrink tube, left open etc... many options!


----------



## TrollDragon

audiofanboy said:


> Definitely a better idea over the long term (_and_ you get that free NOS triode after a few years when the first one weakens, not a leftover "poisoned" triode). I'll actually give that a whirl when I'm done with this ECC88 test.
> 
> Besides, that one 12Ax7 tube I tested, even plugged with lengths of Schiity aluminum cables, actually sounded pretty good. And these tubes could be interesting to use in parallel too. A 12AX7 has very high mu but low gm, so a paralleled 12AX7 would still have the same mu, but -supposedly- more gm and less noise (but more "Miller capacitance" or something, don't ask, I'm doing my best here).
> 
> Again, lads, let's get this stuff tested! A few different shops -in the US- that sell fairly cheap adapters/testers have been mentioned in this thread. All this stuff requires is a pair of adapters (or a DIY adapter made with a chopped up tube base) and some tubes.


 
 If you used the left triode on the left side and the right triode on the right, one could just switch the tubes side for side to implement the free NOS triode's...


----------



## gibosi

audiofanboy said:


> Very true; that was actually my original idea and starting point with that floating 12AT7 tube (but at that time, I was just in a hurry to get my concept tested). But then, I got to think about how a one-tube solution would look. And invariably, a single tube for both channels solution would always be somewhere on the ugly-weird continuum (UWC for short).
> 
> Basically, it would either look weird (one tube in one socket, other socket empty), or ugly (tube floating in between sockets or on a large adapter between sockets).
> 
> Still, if someone wants to give it a try, I say go for it. It's actually pretty easy to adapt these tubes, once you get the pin layout in your head!


 
  
 Yes, any one-tube implementation is going to have a rather high UWC factor. Very true. lol
  
 However, a major benefit to using only one tube is cost. The first time I searched for 6DJ8/ECC88 tubes on eBay was a real case of sticker shock. So it occurs to me that it would be a lot easier on the wallet to audition tubes as singles to determine winners and losers. And then, if reducing the UWC factor is a priority, I could proceed to purchase a few nice pairs. On the other hand, a high UWC factor may actually end up being a source of pride.


----------



## mordy

Personally my preference is sound and not aesthetics. However, sine some people seem to be concerned about the aesthetics, why not cover the wires and adapters with a ventilated tube cage?
  
 Below is an example to give a conceptual idea, but there are obviously numerous different ideas that could apply.


----------



## mordy

Sticker shock?
  
  
 http://www.ebay.com/itm/4-AMPEREX-PQ-HOLLAND-MULLARD-GT-BRITAIN-6DJ8-ECC88-A-FRAME-TUBES-TESTED-VINTAGE-/190910116086?pt=Vintage_Electronics_R2&hash=item2c732130f6


----------



## gibosi

mordy said:


> Sticker shock?
> 
> 
> http://www.ebay.com/itm/4-AMPEREX-PQ-HOLLAND-MULLARD-GT-BRITAIN-6DJ8-ECC88-A-FRAME-TUBES-TESTED-VINTAGE-/190910116086?pt=Vintage_Electronics_R2&hash=item2c732130f6


 
  
 That's just the opening bid. The final price is likely more like this:
  
http://www.ebay.com/itm/2-AMPEREX-6DJ8-ECC88-TUBES-BUGLE-BOY-HEERLEN-1965-MATCHING-DATES-TEST-GREAT-/121179503703?pt=Vintage_Electronics_R2&hash=item1c36dc7c57


----------



## Advil

I just got some Svetlana plant 6c19's from russia after about a month from my order date. I've put them in and I'm hearing a weird rattle from my left channel... Would a burn in period help this at all? I'm worried that I waited over a month for these tubes to have a bad one =\


----------



## TrollDragon

In former Soviet Union Tubes Roll You! 

Switch them around to see if the rattle follows the tube.


----------



## gibosi

advil said:


> I just got some Svetlana plant 6c19's from russia after about a month from my order date. I've put them in and I'm hearing a weird rattle from my left channel... Would a burn in period help this at all? I'm worried that I waited over a month for these tubes to have a bad one =\


 
  
 A good long burn might help... or it might not... As long as it isn't shorting out which might damage your amp, I would say let them burn and see what happens. And good luck!


----------



## Oskari

gibosi said:


> iron58p said:
> 
> 
> > Can be the same ?
> ...


 
  
 Yes and no. Yes, they were both made using _Philips_ tooling and _Philips_ codes. No, they were not made in the same factory; Ei, Niš, Yugoslavia ≠ Mullard, Blackburn, UK.


----------



## gibosi

oskari said:


> Yes and no. Yes, they were both made using _Philips_ tooling and _Philips_ codes. No, they were not made in the same factory; Ei, Niš, Yugoslavia ≠ Mullard, Blackburn, UK.


 
  
 Of course, without seeing them, we cannot say anything for sure. The vendor clearly states: "It is premium quality tube with Philips/Mullard tube codes." And it follows, Philips/Mullard = Blackburn. But again, until someone gets these, we can't be sure....


----------



## Oskari

gibosi said:


> Of course, without seeing them, we cannot say anything for sure.


 
  
 Can't you see the photos? I can see "Yugoslavia", and the brand is given as "Ei".


----------



## Iron58p

I will post a photo when will arrives.
  
 I have a friend that told to me that sounds good.


----------



## manufelices

Hi! I have two questions for the experts:
  
 1. I own an AUNE T1 with an AMPEREX WHITE LABEL 6DJ8 ECC88 1963. I am really happy with the sound. Do you think that does exist difference with the Amperex 7308 Goldpins??
  
 2. I have also a Little Dot MKIII. Is it possible to use at the same time a pair of *M8100*/CV4010/6AK5W MULLARD and  a pair* M8161* EF92 9D6 MULLARD?
  
 Thank you so much


----------



## gibosi

oskari said:


> Can't you see the photos? I can see "Yugoslavia", and the brand is given as "Ei".


 
  
 You are most likely correct... However, as you will remember, we have seen Mullard/Blackburn made Siemens EH90s with "Made in Germany" written on them, and a number of other misleadingly labeled tubes, so I don't necessarily trust what is written on the tube....


----------



## gibosi

manufelices said:


> Hi! I have two questions for the experts:
> 
> 1. I own an AUNE T1 with an AMPEREX WHITE LABEL 6DJ8 ECC88 1963. I am really happy with the sound. Do you think that does exist difference with the Amperex 7308 Goldpins??
> 
> ...


 
  
 1) I have no experience with these dual triodes....
  
 2) Surely, you do not mean using 4 tubes at the same exact time?    But yes, you can use both of these tubes in your LD MKIII. There are jumpers on the circuit board that allow you to change the configuration of your amp to play either EF95 or EF92 tubes. So it is simply a matter of setting the jumpers correctly in order to use these tube types.


----------



## Audiofanboy

mordy said:


> Sticker shock?
> 
> 
> http://www.ebay.com/itm/4-AMPEREX-PQ-HOLLAND-MULLARD-GT-BRITAIN-6DJ8-ECC88-A-FRAME-TUBES-TESTED-VINTAGE-/190910116086?pt=Vintage_Electronics_R2&hash=item2c732130f6


 
  


gibosi said:


> That's just the opening bid. The final price is likely more like this:
> 
> http://www.ebay.com/itm/2-AMPEREX-6DJ8-ECC88-TUBES-BUGLE-BOY-HEERLEN-1965-MATCHING-DATES-TEST-GREAT-/121179503703?pt=Vintage_Electronics_R2&hash=item1c36dc7c57


 
  
 What's interesting is that my EI "Yugo" ECC88 look exactly like those tubes (they should, they were made with the same tooling, just by lesser hands*). They are virtually identical to the Amperex / Philips Heerlen A-frame ones at least. For the price I paid for them, I'd say you can get excellent deals on those tube types. Just stay away from the "genuine" stuff with "proper" labels!
  
 Since half the know world wants 12AX7, the price for those tends to ramp up quickly. On the other hand, I've seen very decent prices for 12AT7 tubes. Just sayin'.
  
 *By "lesser hands", I mean not as good craftsmanship as in Holland; this has nothing to do with the country of origin of these tubes. Before someone starts taking it personally, you know, the last thing we need is a raging Serbian in this thread, we've got enough crazy people as it is lol...


----------



## Iron58p

I'm searching for a pair of 1958 GE 6AV6, that Gibosi have tested.
  
 I have a pair of this tube, but built in the '70s, and i want to compare sound.
  
 Will be ok FIVRE and Toshiba (Multivox), that have the same construction and design.
  
 If someone now or in the future, can help me to find a couple of the 50's, i can tell a big thank's


----------



## mordy

Hi AFB,
  
 I am just curious about what you mean with "lesser hands" in terms of sound. I seem to remember a mention that your Pinnacle mystery tubes looked cheaply made, yet sounded excellent.
  
 Some people have mentioned that the LD MKIII itself seems to be lacking 100% craftsmanship, but as far as I am concerned it is built like a tank, and able to take almost anything you throw at it. Can only remember one or two instances when somebody had a problem necessitating repair, and then it seems it was done for free, even long after the warranty period was over.
  
 In summary, the sound is what matters to me, and obviously the excellent price point.
  
 On another note: Did you have a chance to compare the NEC 6AV6 to Pinnacle?
 Did Yang Sword communicate with you?


----------



## mink42

Little Dot MKIV just arrived. Ta ta for now


----------



## manufelices

gibosi said:


> 1) I have no experience with these dual triodes....
> 
> 2) Surely, you do not mean using 4 tubes at the same exact time?    But yes, you can use both of these tubes in your LD MKIII. There are jumpers on the circuit board that allow you to change the configuration of your amp to play either EF95 or EF92 tubes. So it is simply a matter of setting the jumpers correctly in order to use these tube types.


 
 I mean, they are different types EF95 and EF92 and the manual just say how to change the jumpers in order to use one of them. I am not sure if I can use BOTH of them


----------



## Audiofanboy

mordy said:


> Hi AFB,
> 
> I am just curious about what you mean with "lesser hands" in terms of sound. I seem to remember a mention that your Pinnacle mystery tubes looked cheaply made, yet sounded excellent.
> 
> ...


 
  
 No no, by "lesser hands", I'm just referring to what I've read on this EI company. It's just the typical example where technology is transferred from one factory to an other, and that new factory just doesn't make stuff that's quite as good as the old factory. Think of having the knowledge but not the experience. People buy tubes from companies like EI or Matsush*ta because they are looking for the Mullard/Philips sound but would rather pay 20% of the price for 90% of the quality. If anything, my EI ECC88 look _very _solidly made!
  
 I only got to spend very little time with the NEC 6AV6. While I thought that they were at least decent, they did kind of show the typical "single triode in our LD amps" syndrome, and weren't exactly the most musical tubes. Detailed and balanced though, for sure.
  
 I have not heard from the folks at LD since I mentioned anything technical in our exchanges. They clearly don't like to divulge their secrets...


----------



## Oskari

audiofanboy said:


> Since half the know world wants 12AX7, the price for those tends to ramp up quickly.


 
  
 Indeed. Personally, I think that the beauty of this thread is the love for the oddball types. Why use a 12AX7/ECC83 when you can use two 6AV6/EBC91 tubes? In either case, you have two triodes that are all equivalent to each other.


----------



## Oskari

gibosi said:


> ..., we have seen Mullard/Blackburn made Siemens EH90s with "Made in Germany" written on them, and a number of other misleadingly labeled tubes, so I don't necessarily trust what is written on the tube....


 
  
 I quite agree, in general.
  
 In fact, I wonder whether your GE "Made in Great Britain" 6HM5 tubes without Mullard codes are examples of this. GE certainly did not make them in the UK.


----------



## gibosi

manufelices said:


> I mean, they are different types EF95 and EF92 and the manual just say how to change the jumpers in order to use one of them. I am not sure if I can use BOTH of them


 
  
 If I understand you correctly.... There are two jumpers, one for each socket. So to use two tubes, you need to change two jumpers.


----------



## gibosi

oskari said:


> In fact, I wonder whether your GE "Made in Great Britain" 6HM5 tubes without Mullard codes are examples of this. GE certainly did not make them in the UK.


 
  
 I have been wondering about this too....  GE claims to have had a presence in the UK since the 1930s, but I have not seen any evidence that they had factories there. And further, these tubes do not have the tube number and dots sandblasted into the glass as is typical for GE-manufactured tubes. So if they were actually made in the UK for GE, but not by a Philips subsidiary, then perhaps it was another UK-based manufacturer?


----------



## Sony Slave

razrr1275 said:


> what do you guys think about the GE JAN5654W vs the RCA 5456 Black plate? I'm looking for one more set to go with my Voshkod's and Mullards


 
 I wondering this as well.
  
 I'm also wondering how do the GE JAN5654W vs Tung-Sol 6AK5. How are these tubes different from each other?


----------



## Oskari

gibosi said:


> I have been wondering about this too....  GE claims to have had a presence in the UK since the 1930s, but I have not seen any evidence that they had factories there.


 
  
 What they had were interests:
  

http://www.gracesguide.co.uk/BTH
http://www.gracesguide.co.uk/AEI
  


> So if they were actually made in the UK for GE, but not by a Philips subsidiary, then perhaps it was another UK-based manufacturer?


 
  
 Perhaps, but the seams on top would seem to indicate some relation to Philips. (The evacuation tips cannot be fully seen in your photo.)


----------



## gibosi

oskari said:


> What they had were interests:
> 
> 
> http://www.gracesguide.co.uk/BTH
> ...


 
  
 Yes, the evacuation tips do have four seams, which is quite common on Philips tubes, but again, no tube codes, so I do not know what to think......


----------



## Oskari

gibosi said:


> Yes, the evacuation tips do have four seams, which is quite common on Philips tubes, but again, no tube codes, so I do not know what to think......


 
  
 Some manufacturers with Philips tooling were less devoted to the codes. Ei, BEL, Matsush¡ta, at least. But the internal construction is the key.


----------



## gibosi

oskari said:


> Some manufacturers with Philips tooling were less devoted to the codes. Ei, BEL, Matsush¡ta, at least. *But the internal construction is the key.*


 
  
 And that's the rub... Their internal construction is different than Philips 6HM5 tubes such as Ei, Siemens and GE/Blackburn 6HM5. I have not seen any other tubes like these. So in the end, we have these GE 6HM5 tubes, purportedly made somewhere in Great Britain, by an unknown manufacturer....


----------



## Oskari

Eventually an image will appear.


----------



## kvtaco17

Just a small observation on the sound differences between 6DT6 tubes...
  
*RCA 6DT6A *haven't changed much and remain warm, detailed and expansive. Good bass and treble extension (I'm well over 100 hrs of use) (Square getter and black plates)
  
*Sylvania 6DT6A *my initial review was done around 10 hrs because these seem to have settled BUT now nearing 100 hrs I've noticed they sound a lot less like the RCA's then I reported (I have another set that have not had much use to compare (15 hrs maybe) These are not as warm as the RCA's slightly better bass impact, and better detail retrieval (a by product of less warmth) (Just noticed these have halo getters... grey plates)
  
*GE 6DT6 *improving (around 25 hrs) but I still dislike these... less congested then initially, ok sense of air, some sparkle, light bass impact vs its cousins... a little grainy... flat. (small rectangular getter and ribbed plates)


----------



## MIKELAP

Ordered these today Tung-Sol JTL 6BJ6 from 1959 .What does JTL stand for . Just noticed on tube Sylvania hmm..


----------



## mab1376

mikelap said:


> Ordered these today Tung-Sol JTL 6BJ6 from 1959 .What does JTL stand for . Just noticed on tube Sylvania hmm..


 
  
 I too have wondered What JTL means. Found nothing from a quick google search.


----------



## MIKELAP

mordy said:


> Hi all,
> 
> Sometimes you buy a tube that does not have the manufacturers name on it, but some letters are visible. I just found a little guide that identifies US manufacturers that made tubes for the military - JAN (or Joint Army and Navy tubes). May come in handy:
> 
> ...


 
 Found this from page 26 got my answer thanks mordy


----------



## MIKELAP

Also today got my Russian 6N6PiR tubes ordered on 3 september 2013 you gotta put the year its veryyy... slowwwww... Could they be warmer sounding a bit! i like them especially the price come out to about $20.00 each. From 03/1989


----------



## gibosi

If you are interested in following Audiofanboy into the strange new world of double triodes, you will need a pair of socket adapters/savers in order to disconnect pins 6 and 7 and reroute them to pins 1 and 2 respectively.
  
 You can obtain suitable socket adapters/savers here for only $5.00 each:
  
 http://www.radiodaze.com/product/15450.aspx
  
 Happy tube rolling!


----------



## foreign

mikelap said:


> Also today got my Russian 6N6PiR tubes ordered on 3 september 2013 you gotta put the year its veryyy... slowwwww... Could they be warmer sounding a bit! i like them especially the price come out to about $20.00 each. From 03/1989



I bought the exact same tubes mine seem to have a bit more glow over the standard ones. It looks a lot more better aesthetically speaking


----------



## MIKELAP

gibosi said:


> If you are interested in following Audiofanboy into the strange new world of double triodes, you will need a pair of socket adapters/savers in order to disconnect pins 6 and 7 and reroute them to pins 1 and 2 respectively.
> 
> You can obtain suitable socket adapters/savers here for only $5.00 each:
> 
> ...


 
  
 Thanks ordered some will try it out . The kind of tubes that work with this is the ecc88 tubes are they others !


----------



## gibosi

mikelap said:


> Thanks ordered some will try it out . The kind of tubes that work with this is the ecc88 tubes are they others !


 
  
 And it might be a good idea to get a bunch of these. One pair could be modified to connect pins 1-7, a second pair to connect pins 2-7 and a third pair to connect pins 5-7. This is what I have done, and never having to fiddle with strapping and jumpers is sweet. 
  
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  
 Getting back to double triodes....
  
 For those who are suffering from sticker shock at the prices of 6DJ8 / ECC88, there are some other options that are often less expensive....
  
 As we have seen in other tube families, there are Russian equivalents, the 6N1P and the 6N23P. Searching Google, the 6N1P doesn't seem to get much love, but the 6N23P seems to be pretty good.
  
 And there is a rather strange variant, the 7DJ8 / PCC88. Instead of 6.3 volts, this tube is 7 volts. With only a bit less than a 1 volt difference, this tube can usually be used in place of the 6.3 volt version. And given all the strange tubes we have been sticking into our Little Dots, I see no reason why this shouldn't work just fine,
  
 And finally, there is 6BQ7A / 6BZ7 / ECC180. This tube is similar to the 6DF8 / ECC88 and is often used as a substitute. On the Schiit Tube Rolling threads, here on head-fi,  these tubes have been getting some very positive reviews, and they are often quite cheap.
  
 Happy tube rolling!


----------



## MIKELAP

gibosi said:


> And it might be a good idea to get a bunch of these. One pair could be modified to connect pins 1-7, a second pair to connect pins 2-7 and a third pair to connect pins 5-7. This is what I have done, and never having to fiddle with strapping and jumpers is sweet.
> 
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> 
> ...


 
  you do need 2 double triodes right because i tought i read only one was used you say to disconnect pins 6and 7 on socket adaptor and connect 1 and 7 instead right and you do this to both adaptors .Correct me if i am wrong thanks.


----------



## gibosi

mikelap said:


> you do need 2 double triodes right because i tought i read only one was used you say to disconnect pins 6and 7 on socket adaptor and connect 1 and 7 instead right and you do this to both adaptors .Correct me if i am wrong thanks.


 
 You might want to take another look at Audiofanboy's posting:
  
 http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/3045#post_9830528
  
 He purchased two ECC88 tubes and two socket adapers. In order to use both tubes, it is necessary to disassemble two socket adapters, disconnect pins 6 and 7 and then reroute them to pins 1 and 2, respectively.
  
 Edit: And yes, even though each tube has two triodes, in this configuration, only one triode in each tube is used.
  
 The reason I suggested getting a bunch of these was to more easily allow the use of the various triodes (5-7), pentodes (2-7) and heptodes (1-7) that we have been using up to now. Since you have already purchased custom socket adapters, you will probably only want to buy just two of these adapters to modify for use with double triodes.


----------



## Advil

A month wait for some new power tubes and they're burning in well in my old amp 
  
 Svetlana 6c19 + Mullard M8161 fed from an E17 with line-out dock. Love this.


----------



## TrollDragon

Nice!
Those Green AKG's are some bright though, too much colour bias...


----------



## MIKELAP

gibosi said:


> You might want to take another look at Audiofanboy's posting:
> 
> http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/3045#post_9830528
> 
> ...


 
Its true those 6BQ7A are cheap will order some RCA less than$5.00 each shipping included.Those ECC88 dough very expensive!


----------



## Advil

trolldragon said:


> Nice!
> Those Green AKG's are some bright though, too much colour bias...


 
  
 haha! i love them. they look great next to my bright red ATH-M50's on my desk!


----------



## i luvmusic 2

mab1376 said:


> I too have wondered What JTL means. Found nothing from a quick google search.


 
  
 JUST for TUBE LOVERS maybe.


----------



## i luvmusic 2

advil said:


> A month wait for some new power tubes and they're burning in well in my old amp
> 
> Svetlana 6c19 + Mullard M8161 fed from an E17 with line-out dock. Love this.


 
  
 WOW that is one GOOD LOOKING CAN you have.


----------



## kvtaco17

i luvmusic 2 said:


> WOW that is one GOOD LOOKING CAN you have.


 
 That's what she said?


----------



## TrollDragon

An update to the Strapping Switches...
 Red switches toggle between EF92 and EF95 mode.
  
 Red Up sets EF92 and bottom switches are bypassed.
 Red Down sets EF95 and bottom switches toggle 1-7 / NS / 2-7.


----------



## kvtaco17

Slick!
  
 I assume you wired your switches to the pins for the jumpers and made a simple open/closed circuit? Ive been considering doing the same for awhile... I was gonna use a wire wrapping gun to punch the leads down (simple, secure and fast)... whats been killing me where to mount the switches on the MK1+


----------



## TrollDragon

Thanks kvtaco17!
  
 I just left the jumper in default EF95 mode since it doesn't do anything in that mode.
  
 The switches are soldered via wire to the tube socket pins where they come through the component side of the board.
 Here is the way I wired them up on the MK IV.


----------



## Sony Slave

Does anyone know if you can burn in tubes without music, in other words, can I burn in tubes just by plugging it into a wall and turning it on with tubes installed?
  
 I brought the GE JAN5654W, Voshkod 6ZH1P-EV, and the  Tung-Sol 6AK5 from 1953, I tried to originally purchase the 1956 tubes. But they were already sold out. Do the  Tung-Sol 6AK5 1953 and 1956 tubes sound any different?


----------



## gibosi

sony slave said:


> Does anyone know if you can burn in tubes without music, in other words, can I burn in tubes just by plugging it into a wall and turning it on with tubes installed?


 
  
 No, you do not need to run music to burn them in. However, I have read that it is not good to run the amp without headphones plugged in. I like to listen to the tubes every once in awhile during burn-in, so I usually play music at a very low volume, and then turn it up when I want to listen.


----------



## Acapella11

trolldragon said:


> An update to the Strapping Switches...
> Red switches toggle between EF92 and EF95 mode.
> 
> Red Up sets EF92 and bottom switches are bypassed.
> Red Down sets EF95 and bottom switches toggle 1-7 / NS / 2-7.


 
  
 Love it! Good job Trolldragon.
  
 Oh, and with respect to the GE 6DT6A, I got a little update: They sound very transparent and engaging but I must agree with kvtaco17 that the stage is similar to his 6DT6, although reasonably wide, quite flat.


----------



## gibosi

Received a pair of ECC88 today. These were described as a used pair of Mullards and were pretty cheap. However, while one tube has Blackburn, UK markings, the other has Heerlen, Holland markings, so to call them a Mullard pair is a bit of a stretch...
  
 However, as they say, "When life gives you lemons, make lemonade", so no problem. I figure I can audition them one tube at a time, connecting the three pins for the second triode to a socket adapter installed in the empty socket. And in this way, I can get a taste of the Mullard sound and the Heerlen sound for cheap. And as they are used, they are already burned in!  lol
  
 Hope to get this accomplished later today or tomorrow....


----------



## Sony Slave

gibosi said:


> No, you do not need to run music to burn them in. However, I have read that it is not good to run the amp without headphones plugged in. I like to listen to the tubes every once in awhile during burn-in, so I usually play music at a very low volume, and then turn it up when I want to listen.


 
  
 Ok I see, thank you!
 I'm about to purchase my Little Dot 1+ soon.


----------



## gibosi

Thought some of you might be interested in seeing this up close:
  
 Bent pins 1, 2, 3 and 9 with needle-nose pliers:
  

  
 And then inserted into an adapter, starting with inserting pin 8 into adapter pin-hole 7....
  

  
 Next, will disassemble the adapter and reroute pin 6 to pin 1 (to connect the grid) and pin 7 to pin 2 (to connect the cathode). And then I will make a simple wiring harness to connect the second triode, (bent tube pins 1, 2 and 3 corresponding to the plate, grid and cathode), to socket pin-holes 1 (grid), 2 (cathode) and 5 (plate) in the other socket. And just to be complete, I might try to connect bent pin 9 to a chassis ground.


----------



## gibosi

acapella11 said:


> Oh, and with respect to the GE 6DT6A, I got a little update: They sound very transparent and engaging but I must agree with kvtaco17 that the stage is similar to his 6DT6, although reasonably wide, quite flat.


 
  
 As my experience with the GE 6HZ6 was similar, I am not surprised to hear this. It too had the GE sonic signature that I really like, but a rather flat 2-D sound stage. Again, the venerable GE 8425A is superior to both the GE 6DT6 and 6HZ6, IMHO.


----------



## Sony Slave

Another question, if the little dot does not have a RCA cable/DAC going into it, is it still safe to burn in my tubes (with my headphones plugged in).
 As of right now I do not have a DAC.
  
 BTW my Voshkod 6ZH1P-EV tubes just came in , I will upload a pic once I get to my friends house.


----------



## gibosi

sony slave said:


> Another question, if the little dot does not have a RCA cable/DAC going into it, is it still safe to burn in my tubes (with my headphones plugged in).
> As of right now I do not have a DAC.


 
  
 I think that as long as your headphones are plugged in, everything should be fine. But still, I think you should "listen" to them with your headphones every so often to make sure they are no problems...


----------



## TrollDragon

acapella11 said:


> Love it! Good job Trolldragon.
> 
> Oh, and with respect to the GE 6DT6A, I got a little update: They sound very transparent and engaging but I must agree with kvtaco17 that the stage is similar to his 6DT6, although reasonably wide, quite flat.


Thanks Acapella11!
I needed a tube to try the EF92 mode on the switches and the 6DT6A's where handy... I find they are quite a bit louder in EF92 as I only need 10 o'clock on the volume as opposed to 12.

I still enjoy the sound of the USAF 6AH6WA's the best out of the few tubes I have.


----------



## kvtaco17

The GE's aren't even the best of the 6dt6a's... The RCA are awesome if you like warmth and the Sylvania's are awesome if you want less warmth more dynamics and detail.


----------



## TrollDragon

Well then, I'll have to dig up some RCA's for sure. Thanks!


----------



## mordy

Hi Trolldragon,
  
 I wanted to compliment you on the very neat switch installation you did. Here is a suggestion that I learned from one of my kids:
  
 You do not have any labels for the new switches, which would complete the set up IMHO.  You can use any typing program where you  type out the labels in big letters, and then you minimize them to get the legibility and size to use. Perhaps you could tape on labels, or use adhesive labels, but they can be made very neat this way.
  
 Wish I had the know how and tools to install such switches, but I don't....


----------



## TrollDragon

mordy said:


> Hi Trolldragon,
> 
> I wanted to compliment you on the very neat switch installation you did. Here is a suggestion that I learned from one of my kids:
> 
> ...


 
 Thanks mordy!
  
 I was thinking about picking up a Dymo label maker and some White on Clear tape for it till I saw the price of such... 
	

	
	
		
		

		
			





 It would not get enough use to justify the purchase.
  
 So I'll print out some white letters on a black background with the laser printer.


----------



## Artsi

My first post to this great forum. I could share some impressions about tubes with you fellow Little Dot users.
  
 I currently have following driver tubes: 6K4P -84, 6J3P -84/82, Tungsram 6BE6, GE 6AU6A -70, 6J1P 1991 groove, 6J1P -71, GE JAN 5654 -69, 6J1 -80/77, 6J5P -89.
  
*6K4P* are easily my worst tubes. New from the box these sounded horrifying. Bass was so boomy and otherwise sound was a mess. After some burn-in sound has come way better, but i still don't recommend these for any serious listening. Bass stays little muddy and instrument separation is bad. These need about 40% more volume to sound same db level as others.
http://kuvaton.com/k/Y74R.jpg
  
*6J1P -71* are great for everyday listening. Just a little bit smooth russian sound, but clean and good soundstage. Can't say anything bad about these. Far better than those newer grooved models, that sound little cold with some sort of spike in treble and keep humming noise when hand near. 
http://kuvaton.com/k/Y7Zj.jpg
  
*6J5P -89 *are my best tubes so far. Can't find any flaws. Very analytic and clear sound with great soundstage. Good separation for instruments. When i heard these first time, they made some wow-effect. Can't say that does burning in have made any difference to sound.
http://kuvaton.com/k/Y7Zk.jpg
  
 These impressions are with LD MK II and 6N6P-i -86 powertubes. Hope i get ordered 6N6P-IR -83 tubes soon from Russia.
  
 Sorry about my bad english...


----------



## Audiofanboy

gibosi said:


> Thought some of you might be interested in seeing this up close:
> 
> Bent pins 1, 2, 3 and 9 with needle-nose pliers:
> 
> ...


 
  
 Nice work gibosi! And thanks for taking the time to describe the procedure with pictures (it definitely saves _me_ the time to do it lol).
  
 Looking forward to impressions, for single channeled and dual channeled. I just haven't had the enough time to spend with these new tubes to give actual feedback...


----------



## gibosi

artsi said:


> My first post to this great forum. I could share some impressions about tubes with you fellow Little Dot users.
> 
> *6K4P* are easily my worst tubes. New from the box these sounded horrifying. Bass was so boomy and otherwise sound was a mess. After some burn-in sound has come way better, but i still don't recommend these for any serious listening. Bass stays little muddy and instrument separation is bad. These need about 40% more volume to sound same db level as others.
> http://kuvaton.com/k/Y74R.jpg
> ...


 
  
 Welcome! And your English seems very fine to me. 
  
 I too tried the 6K4P, which is the Soviet equivalent to the 6AU6, and like you, found them to be a waste of money. 
  
 But I have not tried the 6K4P, which is the equivalent to the 6AH6. However, many of us have found the Tung Sol 6AH6, especially the Tung Sol 6AH6W and 6485 to be a top-tier tube. I would be very interested to learn how the 6K4P compares.


----------



## gibosi

audiofanboy said:


> Looking forward to impressions, for single channeled and dual channeled. I just haven't had the enough time to spend with these new tubes to give actual feedback...


 
  
 I am currently running the Blackburn in one socket and the Heerlen in the other as I haven't made a wiring harness yet. But even though they are mismatched and I haven't had them installed for all that long, I am really liking what I am hearing. (But this may be somewhat due to the huge relief I am feeling that I actually got them working! lol 
  
 Anyway I stopped off at an electronics supply store yesterday and picked up a few bits and pieces and hope to find time to make a wiring harness in the next day or two....


----------



## MIKELAP

As i said i ordered my sockets and also got some RCA 6BQ7A on the way read about the procedure to do this and i am really not shure about this so i am going to bug you guys on this until i understand what to do because some of the terminology i dont understand  one thing regarding the pins not all the same pins are used in the 2 tubes and regarding the ground is this still at an experimental stage anyways i am in no hurry to do this i will see how the sockets are made and how the interior of them are made its always easier when you see. Thats going to be fun but hopefully  whihout explosions or radiation leaks getting ahead of myself a bit! my wife always tells me that i have alot of imagination.!


----------



## Audiofanboy

gibosi said:


> I am currently running the Blackburn in one socket and the Heerlen in the other as I haven't made a wiring harness yet. But even though they are mismatched and I haven't had them installed for all that long, I am really liking what I am hearing. (But this may be somewhat due to the huge relief I am feeling that I actually got them working! lol
> 
> Anyway I stopped off at an electronics supply store yesterday and picked up a few bits and pieces and hope to find time to make a wiring harness in the next day or two....


 
  
 I actually just received some nice looking ceramic 9-pin sockets (two pairs), that should allow me to experiment some more, probably more with 12AT7 and 12AX7 tubes -when I get a chance to buy some.
  
 I might also try and wire a pair for running 6DJ8/ECC88 tubes in parallel; but first I need to figure out how I'm even going to wire the sockets to the adapters... Soldering 9 small wires to each socket just doesn't sound fun...


----------



## gibosi

mikelap said:


> As i said i ordered my sockets and also got some RCA 6BQ7A on the way read about the procedure to do this and i am really not shure about this so i am going to bug you guys on this until i understand what to do because some of the terminology i dont understand  one thing regarding the pins not all the same pins are used in the 2 tubes and regarding the ground is this still at an experimental stage anyways i am in no hurry to do this i will see how the sockets are made and how the interior of them are made its always easier when you see. Thats going to be fun but hopefully  whihout explosions or radiation leaks getting ahead of myself a bit! my wife always tells me that i have alot of imagination.!


 
  
 I have two kinds of adapters. The pictured adapter is a little cheaper and simpler, but otherwise, they are essentially the same. There is a long machine screw that extends from top of the adapter and secured with a small nut in the bottom, between the pins. So you simply take it apart.... 
  

  
 This particular adapter is setup for 2-7 pentodes. I used 30 gauge wrapping wire, wrapped and soldered around pins 7 and 2. For these dual triodes, you would need to add another piece of wire to connect pins 6 and 1. Also, for dual triodes, I simply cut pins 6 and 7 short so they do not extend through the bottom of the adapter and into the socket.
  
 Oh, and make sure there is some slack in the wire as it crosses over the hole for the machine screw. On one adapter, the wire was a bit too tight, and when I tried to insert the machine screw, I broke the wire.... (>_<)


----------



## TrollDragon

Here you go mordy!
  
 Hopefully it takes away from that unfinished look, the label paper was very old and didn't print too well. I'll need to print the letters on Mylar or something...
  


Spoiler: LD MK IV Switch Labels...


----------



## MIKELAP

trolldragon said:


> Here you go mordy!
> 
> Hopefully it takes away from that unfinished look, the label paper was very old and didn't print too well. I'll need to print the letters on Mylar or something...
> 
> ...


 
 Looks great.


----------



## MIKELAP

gibosi said:


> I have two kinds of adapters. The pictured adapter is a little cheaper and simpler, but otherwise, they are essentially the same. There is a long machine screw that extends from top of the adapter and secured with a small nut in the bottom, between the pins. So you simply take it apart....
> 
> 
> 
> ...


 
 Thanks gibosi for the nice pictures and explanations will print those pages and save them


----------



## gibosi

mikelap said:


> Thanks gibosi for the nice pictures and explanations will print those pages and save them


 
  
 Up and running in the LD 1+. Except for the fact that they lean - with the bent pins, I can't get them straight - they don't look too bad....


----------



## mordy

Hi G,
  
 You know what they say - "Out of sight, out of mind" - time for a tube cage.
  





 Or, how about using that old bird cage?


----------



## mordy

Mikelap, Trolldragon,
  
 Those labels just look great!


----------



## MIKELAP

gibosi said:


> Up and running in the LD 1+. Except for the fact that they lean - with the bent pins, I can't get them straight - they don't look too bad....


 
  
 Stupid question : Why dont you just cut them off is it just in case might use them for something else eventually just curious.


----------



## mordy

Just got in some new 6AV6 tubes with the rectangular box on top of the top mica. One pair is made by RCA with a peculiar top side getter flash in fashionable dark brown, hereby dubbed the "Sunglass getter flash"  - see picture. The getter looks like a lollipop stick but instead of the top being round it is C shaped (picture 2, 3 and 4). (Lollipop getter)

  
  



  
 Got these cheap, and, perhaps because they are sold as used and thus presumably burnt in, they sound great right out of the bubble wrap. Unfortunately, one of the 6AV6 comrades bit the dust due to poor packaging (not the first time) even though I cautioned the seller to pack the tubes carefully in individual pieces of bubble wrap, and then surrounding all the small packages with more bubble wrap or other packaging materials.
  
 So what we got? A pair of RCA Sunglass-lollipop tubes that sound fantastic. I have learned to do the 5/6 surgery quickly and painlessly. First I take a 6AV6 tube where the pins have been cut off successfully already and hold it up to the new ones. Then I mark the pins to cut off (#5 and #6) with a black marking pen. After this I take my side cutter and hold the tube over my office (or is it Man Cave) garbage can and snip off the pins. Doesn't matter if there are little stubs left; I just cut off a little V shaped piece of electrical tape and cover the stubs. The extra piece of tape that sticks out is cut off and used as a second layer over the stubs.
  
 A second pair of 6AV6 Sylvania was included as well plus one single unknown tube and the GE fatality.Most of the pins were corroded, and I scraped them with my 1949 Colonial pocket knife, and even gave the RCA's the sand bowl treatment.
 One of Sylvanias had barely any volume, so I followed my own advice and scraped it again and again. Success! The Syls don't sound as good as the RCAs, but they may need more time to burn in. (Starting to sound better)
  
 So many thrills in tube rolling! Bargain hunting, corresponding with the seller about the broken tube, finding new tube designs hitherto not seen in my experience, using high tech and highly advanced pin cleaning techniques, and then rewarded with stupendous sound! Wow!


----------



## TrollDragon

I have a pair of the NEC 6AV6's coming on a slow boat from Taiwan...


----------



## TrollDragon

mikelap said:


> Stupid question : Why dont you just cut them off is it just in case might use them for something else eventually just curious.


This was my thought as well, I think when I scrape up some funds to play dual triode. I'll see about grafting a B9A socket onto a B7G socket saver...


----------



## Audiofanboy

gibosi said:


> Oh, and make sure there is some slack in the wire as it crosses over the hole for the machine screw. On one adapter, the wire was a bit too tight, and when I tried to insert the machine screw, I broke the wire.... (>_<)


 
  
 Yeah... Same exact issue happened to me on my first try: I had soldered the bent pins 6 & 7 to pins 1 & 2 straight across the middle of the adapter and couldn't get the screw to go through the adapter straight -basically couldn't close the adapter back up. I eventually got the screw to go straight through but isolated it from the pins to play it safe.
  
 On my second adapter, I bent the pins in a roundabout fashion, but was so focused on that that I soldered the pins the wrong way around... Took me half an hour to get the pins unsoldered...
  


trolldragon said:


> This was my thought as well, I think when I scrape up some funds to play dual triode. I'll see about grafting a B9A socket onto a B7G socket saver...


 
  
 My next project, precisely.
  
 Will report on how hard/cumbersome/ugly it turns out!
  
 I think I'll try and make it "flexible" for my first try. As in, wires soldered to all 9 pins of the B9A socket, but the same wires only tightened onto the adapter and not soldered, so I can play around with different options before settling in on a specific pin layout.


----------



## TrollDragon

Excellent AFB, I'll look forward to your findings and creativity.


----------



## gibosi

mikelap said:


> Stupid question : Why dont you just cut them off is it just in case might use them for something else eventually just curious.


 
  
 Not stupid at all! 
  
 Since there is a second triode in these tubes, an "extra" triode, if you will, if I were to cut off the pins, I would no longer be able to gain access to it. Since we are still experimenting to figure out the best ways to use these tubes, I wish to keep my options open.
  
 And this is especially true with the "pair" I currently have. The vendor listed these as a pair of Mullards. However, one tube is essentially an Amperex, manufactured in Holland, and the other is a Mullard, manufactred in the UK. So I do not wish to continue using these as a "pair" long term. Therefore, I am interested in using both triodes in each tube per this image originally posted by Oskari:
  

  
 I have picked up some parts from a local electronics supply store and intend to make a suitable wiring harness to connect the three bent pins associated with the second triode to a socket adapter installed in the empty socket. Once I get this working (or not), I will post my results with more pictures and info.


----------



## gibosi

audiofanboy said:


> I might also try and wire a pair for running 6DJ8/ECC88 tubes in parallel; but first I need to figure out how I'm even going to wire the sockets to the adapters... Soldering 9 small wires to each socket just doesn't sound fun...


 
  
 What do you see as the advantages of running these tubes in parallel?


----------



## MIKELAP

gibosi said:


> Not stupid at all!
> 
> Since there is a second triode in these tubes, an "extra" triode, if you will, if I were to cut off the pins, I would no longer be able to gain access to it. Since we are still experimenting to figure out the best ways to use these tubes, I wish to keep my options open.
> 
> ...


 
  
 If i got it right we are only using one of the 2 triodes in the tube.


----------



## gibosi

mikelap said:


> If i got it right we are only using one of the 2 triodes in the tube.


 
  
 Yes, you have it exactly right. By bending four pins out of the way (or cutting them off) and then cramming the tube into our 7-pin adapters, we are essentially converting a dual triode into a single triode. But given that these 6FJ8 / ECC88 tubes can be quite expensive, if we could use that second triode, and thus get by with purchasing just one tube, instead of two, our wallets will thank us.


----------



## MIKELAP

gibosi said:


> Yes, you have it exactly right. By bending four pins out of the way (or cutting them off) and then cramming the tube into our 7-pin adapters, we are essentially converting a dual triode into a single triode. But given that these 6FJ8 / ECC88 tubes can be quite expensive, if we could use that second triode, and thus get by with purchasing just one tube, instead of two, our wallets will thank us.


 
i also noticed that they were very expensive you mentionned 6BQ7A tubes those are the ones i got by RCA comes out to $5.00 each next up is learning to solder plenty of videos on the tube ill check that out plenty of time to practice .


----------



## gibosi

mikelap said:


> ...... next up is learning to solder plenty of videos on the tube ill check that out plenty of time to practice .


 
  
 Have fun learning to solder. In my experience, the key to a good electrical solder joint is to make sure you have a good mechanical connection first. Wrap those wires around the adapter pins 2 or 3 times and make sure they are good and tight. If you just touch the wire to the pin and add solder, the joint might end up being pretty bad. Solder on its own is actually a rather poor electrical conductor and its real purpose is to simply ensure that the joint doesn't work loose over time. Good luck!


----------



## TrollDragon

Also heat the pin / wire with the iron and touch the solder to it, don't just melt the solder with the iron.


----------



## Artsi

trolldragon said:


> I have a pair of the NEC 6AV6's coming on a slow boat from Taiwan...


 
  
 I also ordered pair of those. I think it takes 3 weeks to arrive.
  
*6J3P(-E) -84/82* This tube is also what i could recommend. Biggest problem is propably with microphonic. No sound coming through and any touch to amp makes ringing noise, more without -E tube. Ordered two 6J3P and the other one is with -E. Sound seems to be so similar that can't tell any difference with or without -E. Wow-effect is not so strong as with excellent 6J5P, upper range to treble just does not sound so clean. Could microphonic-problem cause some treble-echo...
http://kuvaton.com/k/Y7FI.jpg
  
*GE JAN 5654 **-69* I have listened these work horses many hours before i got those newer Russian tubes. No, these could not be horses, they are so tiny tubes, that work pony is better. Overall sound is pretty good with little bit of harshness. Bass is somehow little bit quieter and quieten more to sub bass. In comparison with Russian basic military 6J1P -71 IMHO Russia wins hands down.
http://kuvaton.com/k/Y7Fk.jpg
  
*Tungsram 6BE6* Manufacturing year is not visible on the tube or on the box. With these soundstage is narrower. Treble has some harshness and bass shares same problems with JAN 5654. Can't describe these better, music just is not so living as with better drivers.
http://kuvaton.com/k/Y7Fi.jpg
  
*GE 6AU6A -70* These were used "pulls from equipment". Sound has some cleanliness problems. Singer s sounds very hissing and treble is bit annoying. Only positive thing is pretty good bass.
http://kuvaton.com/k/Y7Fg.jpg
  
 Afterall these experiences are made with very analytic slightly modded superlux HD-330 headphones. With smooth and easy sounding, sub bass lacking and dull treble sennheiser HD598 user experience is very different. With senns differences are much more difficult to tell. Comparing with senns GE JAN 5654 and 6J1P could turn that GE sounds better with some sharpness and you can't however hear any sub bass quietness.


----------



## Audiofanboy

gibosi said:


> What do you see as the advantages of running these tubes in parallel?


 
  
 Basically, identical gain but higher gm. And theoretically less noise. Of course, it would also solve the unused triode issue...
  
 My only worry is that since a 6DJ8/ECC88 has very high gm per triode in the first place, a paralleled one may end up on the high side; and I'm not exactly looking for 20k gm values, I'd rather have higher mu instead. So, if anything, a 12Ax7 tube might be a better candidate for  paralleling (high (12AT7) to very high (12AX7) mu, medium to low gm); but then again, we don't really have that unused triode issue with 12Ax7 tubes since the triodes can be heated separately...


----------



## gibosi

Put together a wiring harness this morning, but am experiencing a major ground hum coming from the empty socket.....
  
 Anyway, this is what I did:
  
 Found some .062" Pin & Socket M/F Terminals at a local electrical supply store, and thought that the female sockets just might work:
  

  

  
 Crimped the sockets to fit the pins, wired everything up and gave it a try:
  

  
 It may well be that pin 9, the shield grid, needs to be grounded. I did hook up a wire to it and held it against the top right front screw, but didn't hear any difference. Anyway, I will keep looking at this and I hope someone else, with a little more electronics savvy, will give this a try.
  
 For now, will go back to listening to my Mullard/Amperex setup, which by the way, sounds great. A nice, wide, 3D sound stage, great clarity and transparency, warm and engaging tonality and unlike the GE 6AV6, these have a liquid and musical sound, lots of toe-tapping.
  
 These 6DJ8 / ECC88 are well worth the extra time and effort it takes to purchase and wire up some adapters. Highly recommended!


----------



## MIKELAP

trolldragon said:


> Also heat the pin / wire with the iron and touch the solder to it, don't just melt the solder with the iron.


 
  


gibosi said:


> Have fun learning to solder. In my experience, the key to a good electrical solder joint is to make sure you have a good mechanical connection first. Wrap those wires around the adapter pins 2 or 3 times and make sure they are good and tight. If you just touch the wire to the pin and add solder, the joint might end up being pretty bad. Solder on its own is actually a rather poor electrical conductor and its real purpose is to simply ensure that the joint doesn't work loose over time. Good luck!


 
  
 Thanks guys for the tips..What kind of solder would you guys recommend leaded or unleaded and also what diametre. Thanks


----------



## TrollDragon

mikelap said:


> Thanks guys for the tips..What kind of solder would you guys recommend leaded or unleaded and also what diametre. Thanks


 
 This is what I use on a daily basis.
http://www.amazon.com/Kester-Rosin-Core-Solder-Spool/dp/B00068IJPO#productDetails


----------



## gibosi

mikelap said:


> Thanks guys for the tips..What kind of solder would you guys recommend leaded or unleaded and also what diametre. Thanks


 
  
 This is what came with my soldering iron and it seems to be quite fine. But quite frankly, I haven't done any research to find the "best" solder.
  
 Oh, it looks to be similar to TrollDragon's recommendation.


----------



## MIKELAP

Quote: 





trolldragon said:


> This is what I use on a daily basis.
> http://www.amazon.com/Kester-Rosin-Core-Solder-Spool/dp/B00068IJPO#productDetails


 
  
 Thanks also this thing looks very useful do you think so !


----------



## TrollDragon

The "Helping Hand" is very useful as well, I use my little suction base vise and magnified visor more than my "Helping Hand" these days.


----------



## MIKELAP

trolldragon said:


> The "Helping Hand" is very useful as well, I use my little suction base vise and magnified visor more than my "Helping Hand" these days.


 
  
 I was looking at suction vises on amazon what model would be more ergonomic or useful do you think, theres a ton of them


----------



## TrollDragon

You get what you pay for in those... The PanaVise are very nice but a bit spendy.
  
 I have one exactly like this Stalwart.
http://www.amazon.com/Stalwart-75-30654-Portable-Vacuum-Degree/dp/B003BIN38E/ref=pd_sim_sbs_hi_12
 They need a really smooth surface to suction to, if you don't have that then a clamp on one might be better.
  
 This is the Visor I use as well, a little pricey but the lenses are glass and not plastic like the $6 ones, also it has proper optics and you don't have to try and move one of your eyes close to the other one to get it to focus properly like you do in the $6 version.
http://www.amazon.com/dp/B0015IN8J6/ref=biss_dp_t_asn
  
 They have different lenses you can purchase from 1.5X to 3.5X at different focal lengths
http://www.amazon.com/Donegan-OptiVisor-Headband-Magnifier-Magnification/dp/B0068OSIIS/ref=sr_1_5
  
 All fun!


----------



## MIKELAP

trolldragon said:


> You get what you pay for in those... The PanaVise are very nice but a bit spendy.
> 
> I have one exactly like this Stalwart.
> http://www.amazon.com/Stalwart-75-30654-Portable-Vacuum-Degree/dp/B003BIN38E/ref=pd_sim_sbs_hi_12
> ...


 
  


trolldragon said:


> You get what you pay for in those... The PanaVise are very nice but a bit spendy.
> 
> I have one exactly like this Stalwart.
> http://www.amazon.com/
> ...


 
  
 Thanks again that vacuum base vise will work good because my table has a glass top on it Thanks , time to go shopping .


----------



## mordy

Hi All,
  
 Some time back (page 199) I wrote that the 6DT6(A) tube makes me feel toe tapping good, and the 6AV6 tube makes me marvel at the holographic 3D super detailed sound stage with it's natural voice presentation and immediacy. Surely these two tubes are among the best we found to date (together with the 6AU6/8425 and 6AH6WA/6485 tubes.)
  
 Since the advanced DIY soldering projects with wires and adapters are beyond my scope I decided to explore the 6AV6 tube family to see if we could find a tube that combines the awesome intellectual holographic presentation with the emotional impact of the 6DT6 tubes. It was pointed out that the 6AV6 tubes with a an inverted rectangular box on top of the top mica sounded excellent - without the box not the same results. I had five 6AV6 tubes on hand, but only two had the box on the top getter. Even though one was a Sylvania and one a Tung Sol, I burnt them in and was astounded at the sound.
  
 Found a lot of six 6AV6 tubes for cheap ($1.60 each incl shipping). As Providence had it, all six had the box, and in this lot I also found the exact mate to both the Sylvania and the Tung Sol tubes! However, one tube (GE) broke in shipping.
  
 Here are two pictures of the rectangular box on the top mica. Portions of the glass envelope of the tube have been removed for clarity by the USPS for your viewing pleasure. On its own, my camera decided on the sepia color, no doubt to impart a turn of the century flavor.

  

  
 So far, three types have been auditioned: RCA, Sylvania and Tung Sol. They all sound great, with the nod going to the RCA for bringing in more of the emotional (toe tapping impact). The entire sound range is extremely well balanced with delicious detail and sound stage.
  
 I highly recommend getting a pair of any of these 6AV6 tubes with the box on the top mica. Snip off pins 5 and 6, put a piece of electric tape on the stubs, and set the LD on the EF92 setting.
  
 WARNING: The sound is so addictive that you will find it hard to stop listening and going to sleep regular time! (Ouch! Almost 12:30 am, and I have to get up at six!)


----------



## Edgard Varese

Finally rolling in the heptodes tonight.   What do you all think, EF92 or EF95?


----------



## MIKELAP

mordy said:


> Hi All,
> 
> Some time back (page 199) I wrote that the 6DT6(A) tube makes me feel toe tapping good, and the 6AV6 tube makes me marvel at the holographic 3D super detailed sound stage with it's natural voice presentation and immediacy. Surely these two tubes are among the best we found to date (together with the 6AU6/8425 and 6AH6WA/6485 tubes.)
> 
> ...


 
  
 Hey mordy i also checked my 6AV6 tubes for that box on the top mica turns out i have several pairs of those ,G.E. ,WESTINGHOUSE, LORENZ ,and  HIT RAYS, Its true those are among the best sounding tubes with the  with 6AU6 those are the tubes i listen to alot.
 And regarding the new double triode adventure its way over my head but i will take it slowly and wait till everything is sorted out and learn the procedure and after i will do it.theres no rush .Tubes and sockets are on the way.meanwhile time to get some tools and practice my soldering.


----------



## gibosi

edgard varese said:


> Finally rolling in the heptodes tonight.   What do you all think, EF92 or EF95?


 
  
 It really depends on the heptode. Some heptodes sound better EF92 and others EF95. So try both to determine which setting you prefer.


----------



## mordy

Hi Mikelap,
  
 Did you have any opportunity to compare the 6AV6 tubes with the box top? I am looking into buying more of them, but it would be very helpful to know if some are better than others.
  
 I am especially interested in the Lorenz, HitRay and Westinghouse tubes.


----------



## siles1991

I've had currently about 30-40 hours on the RCA 6DT6A's and I can say I definitely like it the most from the rest of the tubes i've tried. Bass impact reaches nice deep and punchy and doesn't bleed into the mids or drown out the highs.  Nice and detailed but not fatiguing like the E91H 2-7 and Televania 2-7 strap, I let some friends try my LD MKIV SE at a gathering and everyone started coming to try it out with all their different headphones xD , it's a really great amp and the tubes are just delicious if only there was a lot of 5. One sad thing that happened to me was I dropped one of my Televania's T.T shattered but good thing I have had a lot of 5 but kind of sad to waste a perfectly good tube...will be looking out for lots of RCA 6DT6A as spares! One thing I wished was that the 6DT6A's had just a little bit more soundstage and just a teensy bitsy more detail but that can be solved with a good DAC(details not soundstage).
  
 Stumbled upon this http://www.r-type.org/exhib/aad0301.htm the PCL800 tube which has 9 pins which is a triode output pentode, so was wondering how'd it fare when put into the "expriments" that are being held.


----------



## mordy

Hi Siles 1991,
  
 Everything you are looking for and more you can find in a pair of box top RCA 6AV6 tubes.


----------



## Acapella11

mordy said:


> Hi All,
> 
> Some time back (page 199) I wrote that the 6DT6(A) tube makes me feel toe tapping good, and the 6AV6 tube makes me marvel at the holographic 3D super detailed sound stage with it's natural voice presentation and immediacy. Surely these two tubes are among the best we found to date (together with the 6AU6/8425 and 6AH6WA/6485 tubes.)


 
  
 I do like my heptodes. The best of them are superior to the best of the 6AU6 and 6AH6 I have.
 I won't comment on the 6DT6A, as it seems I haven't got the the best of them with the GE. A pair of RCAs are incoming. For the 6AV6, I have a pair of Mullard 10M 6AV6, which I really like, but I would position them close to the level of a Raytheon 6BE6W, which overall is my go-to tube at the moment.


----------



## siles1991

mordy said:


> Hi Siles 1991,
> 
> Everything you are looking for and more you can find in a pair of box top RCA 6AV6 tubes.


 
  
 any good deals on them at this moment?


----------



## hypnos1

gibosi said:


> Of course, without seeing them, we cannot say anything for sure. The vendor clearly states: "It is premium quality tube with Philips/Mullard tube codes." And it follows, Philips/Mullard = Blackburn. But again, until someone gets these, we can't be sure....


 
  
 Hi gibosi - and oskari - and anyone else interested, as things seem to have gone very quiet on the 6HM5 front (no wonder, with the exciting experiments going on courtesy of AFB once again!...).
  
 Anyway, my "premium quality tubes for export" arrived today and my word, they are of VERY classy construction. Yugoslavia on them, with codes that ARE Philips, but NOT Mullard...
 Actually : tZ1 (= tube type PCC 85 ) and G5A (G being Loewe Opta, post-1954, and Mullard/Fleetwood prior. As 5 must be '65, we are looking at Loewe therefore - no wonder the tubes look classy...they are quite some outfit, no? And no doubt VERY picky...
  
 So, popped them in; gasped at the blinding flash from their bottoms that ensued; resisted the temptation to switch everything off; calmed down as they settled to a beautiful glow, and (thankfully) was rewarded with a sound that bodes very well indeed right from the off. These would appear to have the potential to knock the lovely RCA 6DT6As off their lovely perch...time will tell...


----------



## Oskari

I'm a bit lost here. Could you please provide a photo of the tube and the code?


----------



## Artsi

It seems that my luck with unbroken tubes has changed. I ordered only 2 NEC 6AV6 from Taiwan and one has cracked glass right from the box. There must have been some tension in glass and temperature variation broke it. Tube has something like white flakes inside. My first broken tube ever.


----------



## TrollDragon

Sorry to hear that Artsi, hopefully mine don't share the same fate.


----------



## kvtaco17

artsi said:


> It seems that my luck with unbroken tubes has changed. I ordered only 2 NEC 6AV6 from Taiwan and one has cracked glass right from the box. There must have been some tension in glass and temperature variation broke it. Tube has something like white flakes inside. My first broken tube ever.


 
 I know the feeling, lost 2 this week... one drop and one failure... sad days...


----------



## MIKELAP

kvtaco17 said:


> I know the feeling, lost 2 this week... one drop and one failure... sad days...


 
  
 Time do go shopping!


----------



## kvtaco17

mikelap said:


> Time do go shopping!


 
 surplus tubes here are coming in handy lol
  
 BUT yeah I need to buy some new ones...


----------



## MIKELAP

kvtaco17 said:


> surplus tubes here are coming in handy lol
> 
> BUT yeah I need to buy some new ones...


 
  
 Usually i try to buy 3tubes or 5 tubes because you never know i had a couple of duds also


----------



## gibosi

oskari said:


> I'm a bit lost here. Could you please provide a photo of the tube and the code?


 
  
 The 6HM5 tube manufactured in Yugoslavia.
  
http://www.ebay.com/itm/6HM5-6HA5-EC900-export-quality-audio-triode-tube-NOS-FREE-SHIPPING-/300879467071?pt=Vintage_Electronics_R2&hash=item460dd0523f
  
 The Philips code on these tubes, G5A, seems to reference Loewe Opta. However, a quick search suggests that Loewe's production facilities were located in Kronach, Oberfranken, Bavaria, Germany. So while it seems clear that these were not manufactured in Mullard's Blackburn factory, it is still not clear where these tubes were actually manufactured..... Bavaria? or Yugoslovia?


----------



## mordy

Oddly enough section:
  
 For the man who has everything: Here is a USB plug in vacuum tube _look_ adapter that does the following:

 
Connects to your Computer's USB 2.0 Port and Delivers Virtual Surround Sound through your Stereo Headphones or Stereo speakers
LFE Mixing ? Enables Low-End Frequencies to be Mixed with Front Channels for Superior Performance
DTS Surround Sensation Headphone Simulates Surround Sound through Headphones with Voice Clarification Technology; Bass Enhancement; and Soundstage Expansion
Provides Two 3.5mm Jacks for Stereo Microphone-In and Stereo Microphone-Out
  
 http://www.amazon.com/IOGEAR-Theater-Sound-Xperience-GUADT51/dp/B0058DN0C4/ref=sr_1_fkmr0_3?ie=UTF8&qid=1380686643&sr=8-3-fkmr0&keywords=6HM5+Vacuum+Tube


 The main use seems to be as a substitute for a broken sound card in a lap top.


----------



## Audiofanboy

hypnos1 said:


> Hi gibosi - and oskari - and anyone else interested, as things seem to have gone very quiet on the 6HM5 front (no wonder, with the exciting experiments going on courtesy of AFB once again!...).
> 
> Anyway, my "premium quality tubes for export" arrived today and my word, they are of VERY classy construction. Yugoslavia on them, with codes that ARE Philips, but NOT Mullard...
> Actually : tZ1 (= tube type PCC 85 ) and *G5A *(G being Loewe Opta, post-1954, and Mullard/Fleetwood prior. As 5 must be '65, we are looking at Loewe therefore - no wonder the tubes look classy...they are quite some outfit, no? And no doubt VERY picky...
> ...


 
  


gibosi said:


> The 6HM5 tube manufactured in Yugoslavia.
> 
> http://www.ebay.com/itm/6HM5-6HA5-EC900-export-quality-audio-triode-tube-NOS-FREE-SHIPPING-/300879467071?pt=Vintage_Electronics_R2&hash=item460dd0523f
> 
> The Philips code on these tubes, *G5A*, seems to reference Loewe Opta. However, a quick search suggests that Loewe's production facilities were located in Kronach, Oberfranken, Bavaria, Germany. So while it seems clear that these were not manufactured in Mullard's Blackburn factory, it is still not clear where these tubes were actually manufactured..... Bavaria? or Yugoslovia?


 
  
 Factory code "*G*", you sure? Maybe factory code:
  

  
 EI, Nish factory, (ex-)Yugoslavia. The similarity with a "G" isn't that obvious here, but on the pics of real tubes I've seen and on my EI ECC88, the factory code circle is longer and more "circle-like", making it look like a 90° turned G to the untrained eye -or uninformed soul lol.
  
 Factory code "G" would make little sense, whereas the EI factory is about the only Yugoslavian tube maker I know about.
  
 Depending on the tube type, EI could have used Philips machinery (ECC88 for instance), Telefunken machinery (ECC83 for example) and maybe even some other production gear for all I know. These tubes, with their shape (top "nib") and codes, could have been made on ex-Philips gear. Or maybe not. If we compare it to a Mullard Blackburn or Philips Heerlen-made tube, we might be able to tell.


----------



## iworkjobs

agree.I spending ~70$ on super-tubes, or am I selling the amp as it is, add another 70$ and buy the darkvoice 336 instead.


----------



## TrollDragon

iworkjobs said:


> agree.I spending ~70$ on super-tubes, or am I selling the amp as it is, add another 70$ and buy the darkvoice 336 instead.



And then over the crackly loud speaker comes...
"Translation in aisle 3... Translation needed in aisle 3."


----------



## mordy

Hi Siles 1991,
  
 Right now I am burning in the Sylvania 6AV6 box top tubes. These have a side getter and the getter flash on the side of the tube. In the beginning they were too harsh in the treble, but that has improved, and they now start to sound "right". Well, fantastic, super duper etc etc.
  
 The way to find good deals is to look at Ebay often. Click on the drop down menu on the right that usually starts with Best Match. Choose Lowest price including shipping. Then scroll down; many times the price for a pair will be lower proportionately than buying individual tubes.
  
 Look at the pictures using the magnifying feature. I have picked up good deals because the seller mislabeled his offer; i.e. Philco tubes that actually were Tung Sol on the pictures. If you cannot see if the tube has the box, ask the seller. It also helps to know the EIA codes when buying off brand tubes. Many times you can see the manufacturer's code on the tube. A pair of Stromberg Carlson tubes had the number 322 on them = Tung Sol. Philco and Zenith may have the number 274 = Sylvania.
  
 Communication is the secret weapon for good deals. Some discount sellers appear many times. If you don't see what you want, ask the seller. Just be prepared for a wait or being ignored at times.
  
 If the listing has a Best Offer feature, use it. Remember, the tubes the folks on this forum have found are not the mainstream tubes, and most likely are very little in demand (until somebody on the blog recommends them). Snagged some 6AV6 tubes recently very cheap. The seller wanted $14.99 for 6 tubes. I offered $6 and it was accepted. Then I offered $5 on another batch of 6 tubes, also accepted. Works out to $1.60 and $1.43/tube incl. shipping. (Wife: Why do you need so many tubes??? Answer: I am looking for Audio Perfection, and besides it was just $1/ tube!)
  
 The 6HM5 Yugo tubes are listed for $6.99 each with free shipping. The seller can't see me blushing for making a shamelessly low offer of $4/tube. Look, you can always go back and pay full price. However, he states he has a box of 100, so maybe he is going to bite on my offer. A counter offer of $5/tube comes back. Fair enough, $10 instead of $14.
  
 If the seller lists the tube for $2.49 and Best Offer is available, bid $1. Worked for me several times. Communicate: Tell the seller that you have this little amp that only can use pairs and ask him/her to look through the stock for a matched pair of of RCA or Sylvania with the same date codes. Just be forewarned that matching pairs means different things to different sellers. To some it means the same brand, to others the same tube designation even if the tubes are of different construction etc.
  
 Don't expect five star service from the 99c stores. However, the rewards are there. My best 6TD6A tubes are Japanese Raytheon that cost 99c each - about $5.25 with shipping for the pair.
  
 Giving away all my secrets - hope something helps. Good Luck!


----------



## TrollDragon

mordy said:


> Giving away all my secrets - hope something helps. Good Luck!


 
 Thanks mordy for allowing us to peek into the inner sanctum of a tube purchasing guru!


----------



## mordy

Hi A11,
  
 I have a pair of Sylvania 6BE6 that you inspired me to try. Which setting works best for you?


----------



## mordy

Hi TD,
  
 The self imposed purchasing limits makes it more interesting to me; max $8/pair, or preferably $4/pair. Once in a while I break down and pay more.
  
 Another not so secret weapon if a seller makes a mistake or a tube breaks in shipment because of poor packaging etc is the E-bay feedback system. Usually any mention of being unhappy and about negative feedback works like a charm to get a refund or replacement. Think twice before leaving negative feedback - it is very damaging to the seller.
  
 If a seller asks you to do transactions outside E-bay - don't. You lose all the protection and it is against E-bay rules.


----------



## TrollDragon

mordy said:


> Hi TD,
> 
> The self imposed purchasing limits makes it more interesting to me; max $8/pair, or preferably $4/pair. Once in a while I break down and pay more.
> 
> ...


 
  
 More excellent tips!
 Yes they all say to contact them for a fix first before any negative feedback is left, I'd really have to be screwed over or ripped off before I'd leave the negative.
  
 The few I have delt with so far have been really accomodating, which I assume is the case for most large scale seller's.


----------



## mordy

Most sellers are decent and honest, but there are some strange people out there.
  
 I bid a low ball offer on a lot of 14 tubes which the seller accepted. A day after the payment went through she contacted me that she cannot find the tubes and refunded the money.
  
 Took a look at her negative feedback record. There was a similar story a few weeks before where she told the buyer that she had sold the item already to the chagrin of the buyer.
  
 The seller was mad at me for leaving negative feedback and sent me an email wishing me all kind of things, which also is against Ebay rules, but I did not follow up on it.
  
 Another seller sent me a nice pair of tubes at a good price. I asked if they had in stock another two pairs of similar tubes. The seller responded by billing me outside of Ebay at a higher price than the first pair. When I asked why I could not get the same price as the first pair they just stonewalled me and canceled the transaction and subsequently refused to sell me.
  
 In general, most sellers are cooperative and honest, and the Ebay rules are very effective in securing good transactions.


----------



## TrollDragon

Yes there are indeed a pile of strange folks on the internet...
  
 The seller I picked up the GE6DT6A's from had the auction for 4, but after I won it he could only find 2. He offered me some other 6DTA6's which I probably should have taken but I asked him about subbing some 6CS6's which he also had on auction instead. He was more than happy to and it really didn't matter to me since I'm new to the rolling game and all the different tubes I can get my hands on the merrier.


----------



## MIKELAP

trolldragon said:


> Yes there are indeed a pile of strange folks on the internet...
> 
> The seller I picked up the GE6DT6A's from had the auction for 4, but after I won it he could only find 2. He offered me some other 6DTA6's which I probably should have taken but I asked him about subbing some 6CS6's which he also had on auction instead. He was more than happy to and it really didn't matter to me since I'm new to the rolling game and all the different tubes I can get my hands on the merrier.


 
  
 Exactly at one point i wonder why i buy them to listen to or to collect either way its fun .


----------



## MIKELAP

And speaking of fun got some 1960 JTL Tung-Sol 6BJ6 today nice and warm sounding compared to the Lorenz EBC91/6av6  alot less emphasis on highs probably not as detailed but a comfy sound i like them .


----------



## kvtaco17

mordy said:


> Hi All,
> 
> Some time back (page 199) I wrote that the 6DT6(A) tube makes me feel toe tapping good, and the 6AV6 tube makes me marvel at the holographic 3D super detailed sound stage with it's natural voice presentation and immediacy. Surely these two tubes are among the best we found to date (together with the 6AU6/8425 and 6AH6WA/6485 tubes.)
> 
> ...


 
  
 Finding a ton of side and halo getters... I did find 2 GE's with the box/rectangle. Really still looking for a few more sets... (RCA's)
  
 Also had another tube die today... that's 3 in 2 days... Kinda lucky I never sold that tube package... a lot of my extra's and doubles were in there lol


----------



## mordy

Hi Mikelap,
  
 The plot thickens:
  
 First of all, I never heard of 6BJ6. Checked my copy of the page 77 list - not there. Went back to the page on the computer. Yep, it is there now with a note that it has not been tested. Are you the first one?
  
 Next: The box says JTL which means Tung Sol. The tube on the picture says JHS which means Sylvania, which is also printed on the tube. Then the box says 188 after the number 5960. 188 is GE.
  
 A triple whammy? Tripolar?
  
 In the Hi Fi world there are two categories of people: Those who like the equipment and those who like the sound. I guess most people on this forum are a combination of both. First I was happy with M8100. Then I was happy with 6J5. Then I was happy with 6AU6/4825. Then I was happy with 6AH6WA. Then I was happy with the EH90/6CS6. Then I was happy with 6DT6. Now I am happy with 6AV6.
  
 Cannot go back to the first two, but I could live with the others  on my list. Who knows what the next favorite is going to be? I don't really collect tubes, but am searching for the one that is going to sound best for me. So I have probably over 300 tubes by now, but I am only using maybe 30-40 of them.
  
 It is a lot of fun to do tube exploration and tube rolling. When I first tried the 6AV6 I could not stand them because the sound stage was crazy with the back in the front. Luckily I did not throw out the tubes. Then we were informed that box top was the secret, and I discovered the fabulous sound of one half of a 12AT7.
  
 After all is said and done,to me, the final reward is listening.....


----------



## TrollDragon

kvtaco17 said:


> Also had another tube die today...


 
 So for those of us who are unwashed in the horrifying death of a tube.
  
 What happens? Hum, Silence, Flames or does it Grenade and send shards of glass flying everywhere? (I'll have to pick up a helmet and visor for the cat). 
	

	
	
		
		

		
		
	


	



 On a serious note, it probably would be wise to snap the power off right away and take the headphones out of the jack.


----------



## Oskari

audiofanboy said:


> Depending on the tube type, EI could have used Philips machinery (ECC88 for instance), Telefunken machinery (ECC83 for example) ...


 
  
 Or like here:
  

http://tctubes.com/Ei-12AX7-ECC83-smooth-plates-ARC.aspx
  
 Telefunken-style internals in Philips-style bottle.


----------



## mordy

kvtaco 17,
  
 Your mortality rate is too high! I had very few tubes die on me, and it was then mainly to trauma. One of my expensive Dutch $85/pair Amperex 5654 tubes fell off a speaker from fright and broke when I cranked up the bass full tilt on a drum recording. (Just kidding, paid $2 but saw them advertised for that price). A 5654 RCA tube lost the vacuum and turned all white inside, maybe from old age - no trauma. A couple of tubes broke during shipping.
  
 Another three tubes that became silent were revived by scraping the pins gently with my trusty pocket knife. Did you try this?
  
 Curious to know what happened that the tubes stopped functioning?


----------



## kvtaco17

trolldragon said:


> So for those of us who are unwashed in the horrifying death of a tube.
> 
> What happens? Hum, Silence, Flames or does it Grenade and send shards of glass flying everywhere? (I'll have to pick up a helmet and visor for the cat).
> 
> ...


 
 There was hum... then more hum (started listening this morning @10am and then about 2 hours ago the hum got really loud... and then a pop sound and nothing... left channel went dead... pulled my PS500 cord out real quick... and now the GE 6DT6 experiment is now over (they weren't very good anyways)... lost 2 of the 3 tubes I had of those in 2 days lol
  
 Now back to the Sylvania 6DT6A I love so much lol (yes I'm cheating on the RCA's)


----------



## kvtaco17

mordy said:


> kvtaco 17,
> 
> Your mortality rate is too high! I had very few tubes die on me, and it was then mainly to trauma. One of my expensive Dutch $85/pair Amperex 5654 tubes fell off a speaker from fright and broke when I cranked up the bass full tilt on a drum recording. (Just kidding, paid $2 but saw them advertised for that price). A 5654 RCA tube lost the vacuum and turned all white inside, maybe from old age - no trauma. A couple of tubes broke during shipping.
> 
> ...


 
  
  
 The GE's lost vacuum (no dropping or mishandling) and the Sylvania I dropped trying to open a door.
  
 I only really cared about the Sylvania, BUT I have another matching pair so not all is lost!


----------



## TrollDragon

kvtaco17 said:


> There was hum... then more hum (started listening this morning @10am and then about 2 hours ago the hum got really loud... and then a pop sound and nothing... left channel went dead... pulled my PS500 cord out real quick... and now the GE 6DT6 experiment is now over (they weren't very good anyways)... lost 2 of the 3 tubes I had of those in 2 days lol
> 
> Now back to the Sylvania 6DT6A I love so much lol (yes I'm cheating on the RCA's)


 
  
 Thanks!


----------



## TrollDragon

Popular Science 1944, a neat little article.
What Tube Can I Use?


----------



## mordy

Just wanted to report that the Sylvania side getter box top 6AV6 have reached a toe tapping index of 5 after 20 hours, so these can be recommended together with the RCAs.
  
 I found that most of the tube pictures on Ebay don't show you clearly if the tube has a box on top. Perhaps emailing the seller a picture and asking him to look will help.


----------



## kvtaco17

you are correct, and most of the sellers I've asked have the halo or side getter...
  
 I assume you like the RCA's better then the Sylvania's then? How are they different sonically?


----------



## hypnos1

hypnos1 said:


> Hi gibosi - and oskari - and anyone else interested, as things seem to have gone very quiet on the 6HM5 front (no wonder, with the exciting experiments going on courtesy of AFB once again!...).
> 
> Anyway, my "premium quality tubes for export" arrived today and my word, they are of VERY classy construction. Yugoslavia on them, with codes that ARE Philips, but NOT Mullard...
> Actually : tZ1 (= tube type PCC 85 ) and G5A (G being Loewe Opta, post-1954, and Mullard/Fleetwood prior. As 5 must be '65, we are looking at Loewe therefore - no wonder the tubes look classy...they are quite some outfit, no? And no doubt VERY picky...
> ...


 
  
  


audiofanboy said:


> Factory code "*G*", you sure? Maybe factory code:
> 
> 
> 
> ...


 
  
 Hi AFB.
  
 Many thanks for putting me on the right track - with stronger glasses, more light and an indication of what to look out for, NOW I see the inverted "G" is NOT a "G", but a very strange symbol similar to your diagram. Sincere apologies for misleading/confusing anyone with my mistake...
  
 They are still, however, a very nicely-made tube and I look forward to hearing more opinions on them. As for myself, early impressions surprised me somewhat, as the sound was quite different to the RCA 6DT6As, and after 20+hrs I still can't decide whether I prefer them or not. I think it could well be down to the extra soundstage/'3D' effect plus more detail. But at the moment I am wondering if this is at the expense of a certain degree of focus and coherence...Vocals appear a bit further in the distance, and to get the same hard-hitting bass requires more volume, which is not so good for my ears! Everything is so wonderfully 'clean' and clear, however, that I pray further burn-in will resolve such matters...Or that I simply need to get used to the different sound!
 Whatever, I do hope more of you get the chance to try out these tubes and post your findings.
 BTW - setting is EF95, no strap (don't know if any other is possible/adviseable...)


----------



## Oskari

hypnos1 said:


> tZ1 (= tube type PCC 85 )


 
  
 Are you sure about the tZ type code?


----------



## Audiofanboy

hypnos1 said:


> Hi AFB.
> 
> Many thanks for putting me on the right track - with stronger glasses, more light and an indication of what to look out for, NOW I see the inverted "G" is NOT a "G", but a very strange symbol similar to your diagram. Sincere apologies for misleading/confusing anyone with my mistake...
> 
> ...


 
  
 Glad I could help 
	

	
	
		
		

		
		
	


	




 .
  
 And yes, those EI Yugo tubes are known for being good deals (solid olde world European tubes for decent prices).
  
 Keep up the good work; we need more people testing new tubes here, can't risk tube stagnation and money saving lol...


----------



## MIKELAP

mordy said:


> Hi Mikelap,
> 
> The plot thickens:
> 
> ...


 
  
 Thats weird ill return em i asked for Tung-Sol dont want nobody's person child a FRANKENTUBE lol.Thats why i got those because they were untested there is not many tubes i dont like either they basically sound all good but have subtle differences which causes the writing on the dang tube to come off just gotta be careful i guess.Maybe if i had 20 year old ears i wouldnt have to change them so often to make up my mind .Thankfully there is some young ears on this thread that will guide us through SUBTILITY AND BEYOND .......


----------



## MIKELAP

audiofanboy said:


> Glad I could help
> 
> 
> 
> ...


 
  
 Like they say ¨ THE ONLY GOOD WALLET IS AN EMPTY WALLET¨ i think !


----------



## TrollDragon

mikelap said:


> Like they say ¨ THE ONLY GOOD WALLET IS AN EMPTY WALLET¨ i think !


But what if the wallet is empty to start with? 
What Do... What Do?


----------



## MIKELAP

trolldragon said:


> But what if the wallet is empty to start with?
> 
> 
> 
> ...


 
  
 i will have to Google that one. ill get back to you !


----------



## kvtaco17

EMPTY IT MOAR! lol


----------



## mordy

Maybe use the stuff on the left of this wallet? No, no, don't max out any credit cards. Just a strange observation: In the tube world less money buys you the same tube that is up to 20 times more from another seller. Would be great just to point to anything at Yen Audio and say: I'll take a dozen! Personally, I just can't do it....
  
  




 Here is an example:
  
 http://www.ebay.com/itm/GE-6AV6-Electronic-Vacuum-Tube-Lot-of-2-/160534029223?pt=LH_DefaultDomain_0&hash=item256092e3a7
  
 and another example:
 http://www.ebay.com/itm/Vintage-2-Pair-GE-6AV6-NOS-NIB-Tubes-/290988243927?pt=Vintage_Electronics_R2&hash=item43c0403bd7


----------



## gibosi

hypnos1 said:


> They are still, however, a very nicely-made tube and I look forward to hearing more opinions on them. As for myself, early impressions surprised me somewhat, as the sound was quite different to the RCA 6DT6As, and after 20+hrs I still can't decide whether I prefer them or not. I think it could well be down to the extra soundstage/'3D' effect plus more detail. But at the moment I am wondering if this is at the expense of a certain degree of focus and coherence...Vocals appear a bit further in the distance, and to get the same hard-hitting bass requires more volume, which is not so good for my ears! Everything is so wonderfully 'clean' and clear, however, that I pray further burn-in will resolve such matters...Or that I simply need to get used to the different sound!
> 
> Whatever, I do hope more of you get the chance to try out these tubes and post your findings.
> 
> BTW - setting is EF95, no strap (don't know if any other is possible/adviseable...)


 
  
 I think your understanding of what you are hearing makes intuitive sense. In a more 2D stage, everything is focused very tightly, right up against your face, so to speak. But in a more 3D sound stage, there is more space between the instruments, especially front to back, and therefore, some vocals and instruments do seem to be further away.
  
 And yes, the setting is EF95. No other settings are possible or advisable.
  
 And these EI tubes do look very similar to my Blackburn tubes, so it would seem very likely that they were manufactured in Yugoslavia using ex-Philips factory equipment. And perhaps they sound similar too.


----------



## gibosi

trolldragon said:


> But what if the wallet is empty to start with?
> 
> 
> 
> ...


 
  
 My situation exactly! Especially now that I am seriously looking at 6DJ8 / ECC88!!  (>_<)


----------



## TrollDragon

Speaking of eBay crazies...

Here is a nice 10 lot of EC88's... :eek:

 www.ebay.com/itm/6N23P-6DJ8-6922-E88CC-Double-Triode-Tubes-Lot-of-10-NEW-NOS-/321177692622


----------



## Edgard Varese

trolldragon said:


> Speaking of eBay crazies...
> 
> Here is a nice 10 lot of EC88's...
> 
> ...


 
  
  
 Is this guy high?  Jeez...


----------



## Edgard Varese

mordy said:


> Maybe use the stuff on the left of this wallet? No, no, don't max out any credit cards. Just a strange observation: In the tube world less money buys you the same tube that is up to 20 times more from another seller. Would be great just to point to anything at Yen Audio and say: I'll take a dozen! Personally, I just can't do it....
> 
> 
> 
> ...


 
  
  
  
 This is one reason why I like those Soviet tubes... I got two lots of 10 each of Reflektors and Svetlanas for $30.  Lots of tubes for next to no money, and while they don't necessarily sound spectacular, they are at least nicely balanced.


----------



## mordy

> www.ebay.com/itm/6N23P-6DJ8-6922-E88CC-Double-Triode-Tubes-Lot-of-10-NEW-NOS-/321177692622


 
  
 I think that there is a mistake here: The tubes are $10, and the shipping is $4500.
  
  
 In case u can't afford it, try this lot:
  
 http://www.ebay.com/itm/USSR-6N23P-6DJ8-6922-E-88CC-6N11-DOUBLE-TRIODE-LITTLE-USED-QTY-4pcs-/221285573530?pt=Vintage_Electronics_R2&hash=item3385a5e39a
  
 The price is $12 and shipping 550 cents. Although the picture shows 6 tubes, the lot consists of four.
  
 I am worried that these tubes emit something that affects the brain function.....


----------



## MIKELAP

mordy said:


> I think that there is a mistake here: The tubes are $10, and the shipping is $4500.
> 
> 
> In case u can't afford it, try this lot:
> ...


 
 Propaganda pure propaganda !


----------



## MIKELAP

mordy said:


> Oddly enough section:
> 
> For the man who has everything: Here is a USB plug in vacuum tube _look_ adapter that does the following:
> 
> ...


 
  
 Hey mordy for the chic tube rolling dude a nice tie clasp. you can also write with it and use it as a screw driver.Who says you cant tube roll and look good at the same time ! Sold!!!!!!!!!


----------



## mordy

I think you forgot the blinking LED lights....


----------



## TrollDragon

There seems to be a bit of a single channel hum when connecting the Ultrasone HFI-780's @ 35Ω to the LD, so I made a 150Ω attenuator plug to connect up the 'Sones.
 Two 150Ω resistors in series with the L+ & R+ signals raises the load on then amp and gets rid of the hum if any of you are experiencing it as well with low Z cans or IEM's
  
 The shells were created with a piece of dowel that was drilled, cut off and then a little Dremel application.
 The 4 wire braid that was already made up otherwise it should have had a cotton or paracord sleeve, but there wasn't any in the build box.
  
 The Attenuator

  
 Connected


 I also changed the LED to amber when I had it apart, the Blue was just a little too intense.
  
 They also make a commercial metal version from 15Ω to 300Ω sold on eBay for those that don't want to DIY.


----------



## TrollDragon

Well a very nice care package was picked up at the post office this morning.
  
 Inside were a pair of Haltron 6CS6's Made in Japan that I had looked at on eBay but were sold by the time I scraped up some cash for them...
 But low and behold hitchhiking along for the ride was a pair of Ruskies!
 The 6А2П from the Oktyabr' Factory in Vinnica Ukraine, what a generous bonus to find. 
  

  
 It will be good to hear something other than GE tubes as that's all I seem to have collected right now...
  
 I will put the 6А2П's in first and fire up some балала́йка music, that way these comrade's can have a nice visit with the electro-harmonic 6H30Pi-EH power tubes and reminisce of life in old country. 
	

	
	
		
		

		
		
	


	




 So a *BIG* Merci à mon très cher ami goes out to our tube roller in La Belle Province!
 Very much appreciated.


----------



## Artsi

I must be crazy, but i ordered 17 different type tubes from electols.com. It is going to take some time to get throught those...


----------



## MIKELAP

artsi said:


> I must be crazy, but i ordered 17 different type tubes from electols.com. It is going to take some time to get throught those...


 
  
 Welcome to the Crazy train my friend .


----------



## Artsi

I asked kindly from my wife, that what if i order some tubes. And she said go for it. Her hobbies are still more expensive.


----------



## mab1376

trolldragon said:


> There seems to be a bit of a single channel hum when connecting the Ultrasone HFI-780's @ 35Ω to the LD, so I made a 150Ω attenuator plug to connect up the 'Sones.
> Two 150Ω resistors in series with the L+ & R+ signals raises the load on then amp and gets rid of the hum if any of you are experiencing it as well with low Z cans or IEM's
> 
> The shells were created with a piece of dowel that was drilled, cut off and then a little Dremel application.
> ...


 
  
 Nice job! I was looking for something like that, didn't have any hum with my HFI-780's or Pro900's though.


----------



## gibosi

A couple small packages have arrived here recently:
  
 These are Amperex Bugle Boy 6DJ8 / ECC88. They have matching Philips tube codes, Delta 0A, so Heerlen, Holland, January, 1960. I am trying very hard to be a bottom-feeder in the 6DJ8 / ECC88 world lol, but finding decent tubes for less than $8.00/tube is tough. These were $13.00/tube shipped, and I feel pretty lucky to have got them for that price. These are now my favorite tubes. 
  

  
 A pair of batch-matched (HK) GE 6DJ8 / ECC88. I found these for $8.50/shipped. However, it appears that one of them was damaged in transit. With the smoked glass it is difficult to see, but the entire getter assembly on the right tube is broken and rattles loose inside the tube...  Very disappointing... I am waiting to hear back from the vendor....


----------



## hypnos1

oskari said:


> Are you sure about the tZ type code?


 
  
  
 Hi Oskari.
  
 I really am screwing up with the identification of these tubes aren't I?! Mind you I do have a good excuse this time - the tube code link on audiotubes.com lists tZ, which is on my tubes, as being PCC85. No wonder you have doubts...looked around, and they are NOTHING like 6HM5s. Thanks for the query...cannot understand what on earth those letters are doing on these tubes. Perhaps my eyesight has totally given up the ghost...and I'm only 63. Is there any hope for me?!! Ah well, live in hope, die in despair - as the saying goes!...
  
 Cheers.


----------



## MIKELAP

gibosi said:


> I have two kinds of adapters. The pictured adapter is a little cheaper and simpler, but otherwise, they are essentially the same. There is a long machine screw that extends from top of the adapter and secured with a small nut in the bottom, between the pins. So you simply take it apart....
> 
> 
> 
> ...


 
  
 Just wanted a precision regarding bottom picture with wire you said its configured for a 2-7 setting my question is the pins are inverted in picture right the wire at top is on pin 2 and at bottom is  pin 7 right


----------



## gibosi

mikelap said:


> Just wanted a precision regarding bottom picture with wire you said its configured for a 2-7 setting my question is the pins are inverted in picture right the wire at top is on pin 2 and at bottom is  pin 7 right


 
  
 Yes, you understand this picture correctly.


----------



## Oskari

hypnos1 said:


> Thanks for the query...cannot understand what on earth those letters are doing on these tubes. Perhaps my eyesight has totally given up the ghost...and I'm only 63. Is there any hope for me?!! Ah well, live in hope, die in despair - as the saying goes!...


 
  
 It doesn't have to be your eyesight. 
	

	
	
		
		

		
			





 The people at Ei might have created this confusion. 
	

	
	
		
		

		
		
	


	



  


gibosi said:


>


 
  
 Mullard seems to have used a three-character type code AEB for 6HM5, if I'm seeing right.
  
 [The code for EC900 (6HA5) is listed as C7.]


----------



## hypnos1

hypnos1 said:


> Hi gibosi - and oskari - and anyone else interested, as things seem to have gone very quiet on the 6HM5 front (no wonder, with the exciting experiments going on courtesy of AFB once again!...).
> 
> Anyway, my "premium quality tubes for export" arrived today and my word, they are of VERY classy construction. Yugoslavia on them, with codes that ARE Philips, but NOT Mullard...
> Actually : tZ1 (= tube type PCC 85 ) and G5A (G being Loewe Opta, post-1954, and Mullard/Fleetwood prior. As 5 must be '65, we are looking at Loewe therefore - no wonder the tubes look classy...they are quite some outfit, no? And no doubt VERY picky...
> ...


 
  
  


audiofanboy said:


> Factory code "*G*", you sure? Maybe factory code:
> 
> 
> 
> ...


 
  
 Hi again AFB... Gibosi and Oskari - you may also be interested...
  
 Curiouser and curiouser...as my symbol was similar but different to yours, I researched further and found one that matches perfectly...and wait for it...it is listed as MULLARD/Whyteleaf ("B").
 What on earth is going on? Mind you, this was from the tube code link at audiotubes.com - the same list that has my tZ code as PCC85! So something VERY weird is going on here, to say the least. Ah well, I'm sure there's a good explanation SOMEWHERE!!
  
 BFN


----------



## Oskari

The Ei symbol can look quite similar to the Whyteleafe "B" plant symbol. See the rightmost photo here:
  

http://www.tubes.rs/Tubes/NOS/Audio/OutPentodes/EL509_EL519_6KG6/EL509_6KG6_EI_Yugoslavia.html


----------



## hypnos1

gibosi said:


> I think your understanding of what you are hearing makes intuitive sense. In a more 2D stage, everything is focused very tightly, right up against your face, so to speak. But in a more 3D sound stage, there is more space between the instruments, especially front to back, and therefore, some vocals and instruments do seem to be further away.
> 
> And yes, the setting is EF95. No other settings are possible or advisable.
> 
> And these EI tubes do look very similar to my Blackburn tubes, so it would seem very likely that they were manufactured in Yugoslavia using ex-Philips factory equipment. And perhaps they sound similar too.


 
  
  
 Hi gibosi.
  
 Yes, I suppose what you say re 2D v 3D brings to mind Holmes and "elementary, my dear Watson"! It's just that I had never noticed such a difference before - obviously these 6HM5s have a MASSIVE soundstage, compared to all the others I have tried before...So take note anyone looking for more "3D" sound.
  
 Also elementary I suppose is that our tube rolling highlights the varying skill/tastes of the recording engineer - something I had never really fully appreciated before (but that can also bring immense frustration, when you hear what CAN be achieved by a Master in the field as opposed to a lesser one...especially when your favourite piece of music ended up in the hands of the latter!)'
  
 Also highlighted is the immense advantage we rollers have over even vastly more expensive (better?) solid state gear - WE can compensate (to a degree) for a so-so engineering job, in a way no equaliser or similar can do...lovely...
  
  
 Happily, with another 20+hrs on them, things are "coming together" quite nicely - ie still tremendous detail, but with more coherence. Bass is developing a bit more...(either that, or I am 'habituating' myself to higher volumes - not to mention early deafness!). Whatever, I think I am falling in love all over again. Oh the pain...


----------



## hypnos1

oskari said:


> The Ei symbol can look quite similar to the Whyteleafe "B" plant symbol. See the rightmost photo here:
> 
> 
> http://www.tubes.rs/Tubes/NOS/Audio/OutPentodes/EL509_EL519_6KG6/EL509_6KG6_EI_Yugoslavia.html


 
  
 Hi Oskari.
  
 Yes indeed, VERY similar...but mine are much more like the other. Perhaps they were using the wrong stamp?!!
 Thanks for your interest.
  
 Time for a scrub.
 BFN


----------



## gibosi

oskari said:


> It doesn't have to be your eyesight.
> 
> 
> 
> ...


 
  
 Yes, you are seeing right, it is AEB. On the other hand, the RCA/Siemens 6HM5 (the ones that sound like crap) has C7. Quite confusing indeed! lol


----------



## Oskari

Perhaps C7 designates the shorter bottle type.
  
 P.S. A couple of links for the interested:
  
http://frank.yueksel.org/other/Philips/PhilipsCodeListAB-v10.pdf
http://frank.yueksel.org/other/Philips/PhilipsCodeList.pdf


----------



## Sony Slave

I finally received my Voshkods straight outta Mother Russia, they were shipped from Moscow. They're beautiful!


----------



## Acapella11

mordy said:


> Hi A11,
> 
> I have a pair of Sylvania 6BE6 that you inspired me to try. Which setting works best for you?


 
  
 Hi Mordy,
  
 Sorry for the late response but my spare doesn't match the vibrancy of this thread at the moment!
 I mostly use 2/7-strap with my Raytheon 6BE6W, 1/7 is a bit less forward but has others qualities you may discover. =) This still is "my tube of choice" at the moment.
 May RCA 6DT6A still haven't arrived. I'll come back later on this one.


----------



## Acapella11

trolldragon said:


> There seems to be a bit of a single channel hum when connecting the Ultrasone HFI-780's @ 35Ω to the LD, so I made a 150Ω attenuator plug to connect up the 'Sones.
> Two 150Ω resistors in series with the L+ & R+ signals raises the load on then amp and gets rid of the hum if any of you are experiencing it as well with low Z cans or IEM's
> 
> The shells were created with a piece of dowel that was drilled, cut off and then a little Dremel application.
> ...


 
  
 Great DIY stuff Trolldragon. If you open up an online store, we might get more in touch.


----------



## kvtaco17

Just throwing this out there, BUT the HD800 doesn't do so bad on the MK1+
  
 I just finally bought these today (damn you brick and mortar boutique audio shops!) and while my Schiit stack and o2 power these well enough (I first heard these on a Taboo III) the baby Little Dot holds its own even in low gain! The detail level is similar to the o2 combo and Schiit Magni and Modi stack. SO just saying, I think this little guy will scale a bit if I fed it better. Anyone have a super nice/expensive/amazing DAC feeding the MK1+? What did you think?


----------



## gibosi

kvtaco17 said:


> Just throwing this out there, BUT the HD800 doesn't do so bad on the MK1+
> 
> I just finally bought these today (damn you brick and mortar boutique audio shops!) and while my Schiit stack and o2 power these well enough (I first heard these on a Taboo III) the baby Little Dot holds its own even in low gain! The detail level is similar to the o2 combo and Schiit Magni and Modi stack. SO just saying, I think this little guy will scale a bit if I fed it better. Anyone have a super nice/expensive/amazing DAC feeding the MK1+? What did you think?


 
  
 I had a chance to listen to the HD800 (300 Ohms) recently, and like you, I thought it sounded fine on my LD1+. And I have been I wondering how much of this is a direct function of the installed op amp? Or is it more complicated? For example, the technical info for the LME49990 op amp explicitly states that it "Easily Drives 600Ω Load." I didn't try the HD 800 with the stock op amp, so I have no idea if that would have made any difference....
  
 Unfortunately, the best I DAC I have used with the LD1+ is the Schiit Modi, so can't add anything....


----------



## kvtaco17

gibosi said:


> I had a chance to listen to the HD800 (300 Ohms) recently, and like you, I thought it sounded fine on my LD1+. And I have been I wondering how much of this is a direct function of the installed op amp? Or is it more complicated? For example, the technical info for the LME49990 op amp explicitly states that it "Easily Drives 600Ω Load." I didn't try the HD 800 with the stock op amp, so I have no idea if that would have made any difference....
> 
> Unfortunately, the best I DAC I have used with the LD1+ is the Schiit Modi, so can't add anything....


 
 You make a good point about the opamp... I do have the stock one around here somewhere to demo... Now you've gone and made me curious!


----------



## Sony Slave

kvtaco17 said:


> Just throwing this out there, BUT the HD800 doesn't do so bad on the MK1+
> 
> I just finally bought these today (damn you brick and mortar boutique audio shops!) and while my Schiit stack and o2 power these well enough (I first heard these on a Taboo III) the baby Little Dot holds its own even in low gain! The detail level is similar to the o2 combo and Schiit Magni and Modi stack. SO just saying, I think this little guy will scale a bit if I fed it better. Anyone have a super nice/expensive/amazing DAC feeding the MK1+? What did you think?


 
  
 I'm going to order an Uber Bi-Frost in a couple of days.
 I'll tell you what I think when I get it with the little dot.
  
 I'll install my Voshkods and LME49990 op amp in the Little Dot 1+, Uber daughter board on the bi-frost, it will all be played in my Shure 840 headphones.


----------



## gibosi

hypnos1 said:


> Yes, I suppose what you say re 2D v 3D brings to mind Holmes and "elementary, my dear Watson"! It's just that I had never noticed such a difference before - obviously these 6HM5s have a MASSIVE soundstage, compared to all the others I have tried before...So take note anyone looking for more "3D" sound.
> 
> Happily, with another 20+hrs on them, things are "coming together" quite nicely - ie still tremendous detail, but with more coherence. Bass is developing a bit more...(either that, or I am 'habituating' myself to higher volumes - not to mention early deafness!). Whatever, I think I am falling in love all over again. Oh the pain...


 
  
 And I have been having the same experience with the 6DJ8. At first, the vocals just didn't seem quite right - too distant. But again, it is that spacious sound stage that takes some time to get used to, I think. This evening I heard background vocals that actually sounded like the singers were located "behind" the lead, and everything just seemed to be where it belonged.


----------



## TrollDragon

The Haltron 6CS6

  
 The 6A2П's from the October Ukraine, Vinnitsa factory.
 
  


Spoiler: Then you plug it in and the Magic Happens!





  


  
 The first song played on the 6A2П's in EF95 1-7 was BB Gabor's Moscow Drug Club.


----------



## kvtaco17

sony slave said:


> I'm going to order an Uber Bi-Frost in a couple of days.
> I'll tell you what I think when I get it with the little dot.
> 
> I'll install my Voshkods and LME49990 op amp in the Little Dot 1+, Uber daughter board on the bi-frost, it will all be played in my Shure 840 headphones.


 
 Sounds good!
  
 I'm really curious about the scalability of these amps with better cans, and how our choices of tubes affects the end result we hear.


----------



## gibosi

trolldragon said:


> The Haltron 6CS6


 
  
 Ah yes, it appears you have a pair of Toshiba-made 6CS6. These are nice tubes.


----------



## TrollDragon

Excellent, I'll have to give them a listen after the Soviets. 
Thanks gibosi!


----------



## Artsi

Burning in pair westinghouse 6AV6 tubes. First tubes that needed jumper change to ef91/92. Tubes are made in Japan and they look identical with NEC 6AV6. Sound have been very good from the beginning. Tungsram 6BE6 seems to sound little better in ef92 mode , but sound still has somekind dull filter. Westinghouse does everything way better and clearer.


----------



## TrollDragon

My NEC 6AV6's arrived today in good shape. Seller only uses newspaper to pack with...

Lopping off the two pins later tonight, and will give a listen this weekend.


----------



## mab1376

trolldragon said:


> My NEC 6AV6's arrived today in good shape. Seller only uses newspaper to pack with...
> 
> Lopping off the two pins later tonight, and will give a listen this weekend.


 
  
 Anyone have any feedback on some good 6AV6's? I love my Mullard 10M 6AV6, the RCA is ok, and I only have one JTL Sylvania since I cracked the base on my other one clipping the pins.


----------



## gibosi

mab1376 said:


> Anyone have any feedback on some good 6AV6's? I love my Mullard 10M 6AV6, the RCA is ok, and I only have one JTL Sylvania since I cracked the base on my other one clipping the pins.


 
  
 Any of what I would call the "GE-style" of 6AV6. These have a box-like structure mounted on the top mica and "mountain peak"-style diode plates. To date, I have found FIVRE, Toshiba, Tung-Sol and of course GE.
  
 Toshiba
  

  
 Tung-Sol
  

  
 FIVRE
  

  
 GE


----------



## mab1376

gibosi said:


> Any of what I would call the "GE-style" of 6AV6. These have a box-like structure mounted on the top mica and "mountain peak"-style diode plates. To date, I have found FIVRE, Toshiba, Tung-Sol and of course GE.
> 
> Toshiba
> 
> ...


 
  
 oh nice, i've always like the tung-sol "house sound" i'll see if i can pickup a pair to try.


----------



## MIKELAP

Got my socket today looks like its not going to be easy to solder the wires because you cannot remove the top part from the housing completely whithout the pins coming out of the housing plus my wire is 22 gauge will see if its small enough .Thats all the space i have to work with 5/16 wide


----------



## mordy

Hi Gibosi,
  
 "Ah yes, it appears you have a pair of Toshiba-made 6CS6. These are nice tubes. "
  
  
 I have a pair of Raytheon 6DT6A made in Japan plus the Siemens Foreign  EH90 and Haltron 6CS6. They all look like they were made in the same factory. Since we know know that there is a connection between Hitachi and Raytheon, how can you know if all these tubes were made by Hitachi and not by Toshiba? (Perhaps Toshiba made them for Hitachi when it comes to the Raytheon tubes?)
  
 Have not been able to find out much about the production and differences between the Toshiba and Hitachi tube factories.
  
 The bottom line is that these are all very nice tubes.


----------



## Audiofanboy

mikelap said:


> Got my socket today looks like its not going to be easy to solder the wires because you cannot remove the top part from the housing completely whithout the pins coming out of the housing plus my wire is 22 gauge will see if its small enough .Thats all the space i have to work with 5/16 wide


 
  
 You can just pull the pins out of the housing; it'll be virtually impossible to do anything otherwise. The pins are annoying to put back in their holes afterwards, especially if you try to force them in holding the top part, but they end up going back in fairly easily if you just put them back in their housing and "wiggle" the whole adapter until they go in. The pins eventually go back in their holes that way, or so I've found.
  
 If anything, I find that the screw that holds the whole assembly together is problematic. Every time I take the adapter apart, the screw _never_ goes straight in its hole, and gets stuck sideways...
  
 On a lighter note, I made a better adapter to use a single 12Ax7 tube as a driver, using two of these brown socket savers/testers and some wire (too short this time, unlike my original "flying" tube experiment). It worked like a charm until I started loosing sound in one channel for half a second every five minutes, and the also in the other channel eventually... I thought the wiring was bad, but I triple checked it, so I have to assume that the tube might be a bit dodgy (I salvaged it from a stack of random tubes I paid 99 pence for, and the only other valuable tube in that stash turned out to be a dud as well, so hardly surprising).
  
 Guess I need to find more 12AT7/ECC81 & 12AX7/ECC83 now huh?


----------



## TrollDragon

Sorry these totally slipped by...
  
 Quote:


mab1376 said:


> Nice job! I was looking for something like that, didn't have any hum with my HFI-780's or Pro900's though.


 
 Thanks mab1376!
 I didn't have a hum in the beginning with the 5654's, I'll have to put them back in and see. 


acapella11 said:


> Great DIY stuff Trolldragon. If you open up an online store, we might get more in touch.


 
 Thanks A11!
 My stuff is strictly amateur, I made a free novelty interconnect for a young Head-Fi'er in another thread and it stopped working within a week, told him to be careful with it as it lacked strain relief.
 I'm not by any means saying he was rough on it, but that made me realize in order to sell a product, the product has to be a lot sturdier than the ones i make for myself... 
	

	
	
		
		

		
			





 
 People seem to have this burning desire to yank things out by the cord and and even carry them by the cord.
  
 But If I do, I'll be sure to let you all know!


----------



## mordy

Hi AFB,
  
 Can you explain to me what you gain by using one tube 12AT7 in the LD MKIII compared to using one pair of 6AV6 that are said to be one half of the 12AT7?


----------



## TrollDragon

mikelap said:


> Got my socket today looks like its not going to be easy to solder the wires because you cannot remove the top part from the housing completely whithout the pins coming out of the housing plus my wire is 22 gauge will see if its small enough .Thats all the space i have to work with 5/16 wide


 
 There is absolutely nothing more *entertaining* and *invigorating* than a chummy that requires 12 fingers to put it back together after you take the screw out.


----------



## MIKELAP

trolldragon said:


> There is absolutely nothing more *entertaining* and *invigorating* than a chummy that requires 12 fingers to put it back together after you take the screw out.


 
screwActually i was really lucky putting the pins back in took me less than 5 minutes using a tooth pick but i was lucky afterwards putting the srcew i dropped the d....m screw took me 15 minutes to find it .Not starting out good and  i didnt even start soldering yet lol


----------



## mordy

HI mab 1376,
  
  
 Re the 6AV6, it appears that the only good ones are the ones with the box on top of the top mica. Are your tubes made in this way? (Would not worry if the plate has a pointy notch or not - does not seem to matter.)
  
 Just finished burning in a pair of Sylvania box top side getter 6AV6. These tubes sound absolutely fantastic in my system, maybe even better than the RCAs I have (lollipop getter, sunglasses look).
  
 Specifically, the Syls have a meaty, juicy detailed bass, great mid range and excellent treble. In addition they are very engaging with a TT index of 5.
  
 Here are a few pictures of these tubes.
 Picture showing the logo (stylized oak leaf) and construction of the tube. Notice the little disc on top.

 I have three of these tubes. When I burned them in I did not realize that the little disc on top was bigger on one tube. However, they sound the same, and the third tube matches the one with the smaller disc.

 Notice the box on the mica. It has notches in it, but the the third tube with the small disc does not have those notches.

 Here you can see the difference in size of the dish antenna on top.

  
 Bottom line: These are my favorites now.


----------



## Audiofanboy

mordy said:


> Hi AFB,
> 
> Can you explain to me what you gain by using one tube 12AT7 in the LD MKIII compared to using one pair of 6AV6 that are said to be one half of the 12AT7?




Simple. There evidently is more variety and latent sound quality to be found in the 12Ax7 tubes than in the 6AV6 family, where we've been kind of finding out that there's only half a dozen tube constructions -like those "box" getter tubes- and basically not that much to select from, even though the tubes are cheap.

Also, there is 1000 times more information out there on 12Ax7 and 6DJ8 tubes -hence the crazy prices- which makes it so much more easy to find good tubes for those types; even though we may not be able to actually afford them lol...


----------



## mordy

Hi AFB,
  
 Thanks for your answer. I am awaiting a comparison of the sound of a favored 12AT7 with the best of the 6AV6 tubes.
  
 The other thing that I would like is a detailed step by step guide with pictures how to connect these tubes, which adapters to use, which wires to solder where etc. Perhaps this information can be gleaned from various posts, but it is not very clear to me. It also seems that the simplest and best ways of doing this is still a project in the making.
  
 And thanks for all your pioneering work in enhancing the listening experience using the LD MKIII!


----------



## Artsi

Westinghouse 6AV6 -91 made in japan. Shortly: Great sound, with excellent analytics, and/but dryness.
  
 Especially with bass you do just what you told to do just like in army. Headphone speaker does not do any more movements than music says. Some people like this and some like more softened sound.
  
  
 Edit: did not mean this "dryness" straight as negative thing. It just made me smiling to hear such preciseness in every bass impact and vibration.


----------



## mordy

Hi Artsi,
  
 Don't know how long you have used your Westinghouse 6AV6 tubes, but I have not come across a tube that changes more after 40-50 hours burn in, all for the positive. I have a feeling that if you give them a chance, they will improve in all aspects. With the ones I have tried, all the things that I did not like "burned" away....


----------



## MIKELAP

mordy said:


> Hi AFB,
> 
> Thanks for your answer. I am awaiting a comparison of the sound of a favored 12AT7 with the best of the 6AV6 tubes.
> 
> ...


 
 Looks like theres 2 mods  one is this by AFB :
 Yes, basically you are trying to use only the first triode in the tube, so all the leftover pins need to be neutralized or at least out of the way. So, pins 1, 2, 3 & 9 of the 6BQ7A need to be bent or cut, while pins 4, 5, 6, 7 & 8 can be inserted in a sequence into the socket hole 3, 4, 5, 6 & 7 of your adapter. Next, you just have to link/solder pin 6 to pin 1, and pin 7 to pin 2 on the adapter (with pins 6 & 7 disconnected at the base), and voila! You get a single 7-pin triode!
  
 Gibosi actually summed it up better than I can in his post:
  
http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/3145
 And on post #3145 at the bottom gibosi speaks of a wiring harness that is linked to another socket with no tube this mod using the 2 triodes of the tube instead of one if i am not mistaken in the first mod. One thing thats not clear in 2nd mod  is the ground part is that settled ? Thats what i think i know am i correct ? A complete procedure would be great in time when everything is settled and clear.


----------



## mordy

*MORDY'S QUICK CHANGE JUMPERS*
  
 And, now for all of us with fumbly fingers like me, here is another idea of how to make it easy to change those pesky jumpers underneath the LD MKIII amp from EF95 to EF92 and back and forth.
  
 First, I raised my amp about an inch by sticking on my 1980s hi fi cones on the bottom of the amp with blue tack (well actually yellow tack from the 99c store).
 Raising the amp allows for more heat dissipation through convection, and the pointy cones dissipate unwanted vibrations from wherever. I have no problems with microphonics at all. In truth, anything  to raise it will work - pieces of wood, plastic, whatever.

 Next to the front cone you can see a black and white piece of plastic sticking out. Those are the handles to the jumpers.

 Here are the jumpers with extensions attached. The extensions were taken from the click mechanism of Uniball gel pens. The jumpers have long handles but I don't know where to get these with a round tail - these came with a solar powered house number set. The long handle jumpers that you can buy probably can be cut to fit inside the hole on the plastic piece.

 Here is the jumper with handle detached. It is just a pressure fit to make it stay on.

 To change jumpers I tilt the amp left on it's side. EF95 means that the jumper gets pushed into the upper part of the oval hole, EF92 into the bottom of the oval hole. In order to make it easier to see where the jumper goes I use a little LED flashlight.
  
 This makes it much easier. Maybe an upgraded MKIII will come with simple switches on the back plate and array of adapters for all kinds of tube types...


----------



## gibosi

mordy said:


> HI mab 1376,
> 
> Re the 6AV6, it appears that the only good ones are the ones with the box on top of the top mica. Are your tubes made in this way? (Would not worry if the plate has a pointy notch or not - does not seem to matter.)


 
  
 To clarify, so far, all the 6AV6 I have tried with the pointy notched diode plates sound the same. Therefore, the GE, FIVRE, Toshiba and Tung-Sol, all sound like the GE 6AV6. Your experience confirms that RCAs and Sylvanias, with the box, but different style diode plates, also sound very good, but different than the GE.


----------



## MIKELAP

mikelap said:


> Looks like theres 2 mods  one is this by AFB :
> Yes, basically you are trying to use only the first triode in the tube, so all the leftover pins need to be neutralized or at least out of the way. So, pins 1, 2, 3 & 9 of the 6BQ7A need to be bent or cut, while pins 4, 5, 6, 7 & 8 can be inserted in a sequence into the socket hole 3, 4, 5, 6 & 7 of your adapter. Next, you just have to link/solder pin 6 to pin 1, and pin 7 to pin 2 on the adapter (with pins 6 & 7 disconnected at the base), and voila! You get a single 7-pin triode!
> 
> Gibosi actually summed it up better than I can in his post:
> ...


 
  
 What does disconnect pins 6 and 7 at the base mean exactly remove them ?And is that at base of socket those are the pins that will go in LD that are cut Thanks.


----------



## Audiofanboy

mikelap said:


> What does disconnect pins 6 and 7 at the base mean exactly .Thanks.


 
  
 Easy, just chop them off! Take your adapters apart, bend pins 6 & 7 at a 90° angle (going towards pins 1 & 2 but not through the center part of the adapter, so you don't block the screw), *chop off* the part of pins 6 & 7 that goes too far (just leave enough of the pins to make good contact and solder onto pins 1 & 2), and solder bent pins 6 & 7 to pins 1 & 2! Then put the adapter back together.
  
 I should have taken pictures of one the adapted adapters, but alas, I never think about doing that when I'm actually making stuff, too much excitement as it is -and I don't like to show my crappy solder work too lol...


----------



## gibosi

mikelap said:


> Looks like theres 2 mods  one is this by AFB :
> Yes, basically you are trying to use only the first triode in the tube, so all the leftover pins need to be neutralized or at least out of the way. So, pins 1, 2, 3 & 9 of the 6BQ7A need to be bent or cut, while pins 4, 5, 6, 7 & 8 can be inserted in a sequence into the socket hole 3, 4, 5, 6 & 7 of your adapter. Next, you just have to link/solder pin 6 to pin 1, and pin 7 to pin 2 on the adapter (with pins 6 & 7 disconnected at the base), and voila! You get a single 7-pin triode!
> 
> And on post #3145 at the bottom gibosi speaks of a wiring harness that is linked to another socket with no tube this mod using the 2 triodes of the tube instead of one if i am not mistaken in the first mod. One thing thats not clear in 2nd mod  is the ground part is that settled ? Thats what i think i know am i correct ? A complete procedure would be great in time when everything is settled and clear.


 
  
 I tried to use both triodes in the tube, plugging the tube into the left socket and connecting the second triode - cathode, grid and plate - to the appropriate pins in a socket adapter plugged into the right socket.
  
 http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/3180#post_9847725
  
 However, there was a very strong ground hum from the empty socket on the right. As this ground hum is totally independent of the volume, I suspect that there is some kind of grounding problem relative to the two sockets. My suspicion is that it might be a result of the fact that both cathodes, left and right, are being heated through the left socket. The only idea I have had to date is to connect pin 9, a shield grid, to a chassis ground. However, as I do not have much hope that this will actually work, I haven't gotten around to giving it a try....


----------



## TrollDragon

All the heater wires come directly from the torrid transformer on top. 2 pair for the back and 2 pair for the front. I'll have to pull off the cover ans see if there is a number on it for a pinout.

If the two front windings are center tapped then you would just need the appropriate wire from each side for the 12V heater. I would look for a pinout first before you bridged and heater wires though.


----------



## TrollDragon

Hey AFB!

MIKELAP sent me a picture of what is your MK IV SE's board section, there is a Linear 1084 modded in on a heat sink. Is this stock or a mod you have done? Possibly a CCS implementation? The input caps are missing as well. Do you have any full pics of the board?


----------



## TrollDragon

Well took the 6AV6's down to my little workshop, cleaned up the pins and loaded a 1/32" rigid cutting disk into the Dremel.

Half speed spin and precisely lopped of the two pins perfectly flush with the glass base, there isn't even a little ridge that you can feel with a finger nail.

A job well done, very clean and easy till I looked closer and realised I had cut off 4 & 5... 

So I lopped off 6 and made a little pad out of solder wick to butt solder to the flush pin 4 stub, twisted two Cat5 strands very tightly and soldered that to the pad. Checked the heater pins with the meter and there is continuity.

It won't last but it will allow me to try out the NEC's to see if its worth getting a replacement tube or two from Taiwan.

Of all the bone headed maneuver's...


----------



## MIKELAP

trolldragon said:


> Well took the 6AV6's down to my little workshop, cleaned up the pins and loaded a 1/32" rigid cutting disk into the Dremel.
> 
> Half speed spin and precisely lopped of the two pins perfectly flush with the glass base, there isn't even a little ridge that you can feel with a finger nail.
> 
> ...


 
Everytime before cutting  i always look at this picture i took.Better safe then sorry.and i use a cutter more control . Arrows show pins to be cutoff.


----------



## gibosi

trolldragon said:


> If the two front windings are center tapped then you would just need the appropriate wire from each side for the 12V heater. I would look for a pinout first before you bridged and heater wires though.


 
  
 I am afraid that doing something like this is way beyond my comfort level!  And even if, since the 6DJ8 is a 6 volt tube, with only one set of heaters, pins 4 and 5, servicing both triodes, I really can't see how it would be possible to heat them separately.
  
 Another idea rattling through my mind is strapping the two cathodes together, but I worry about an inadvertent fireworks display lol.
  
 At this point, I figure I am in way over my head, and have resigned myself to continue listening to mangled pairs of 6DJ8 for the time being. But of course, I am hoping someone with more experience and expertise might be able to figure out a way to use both triodes in one tube.


----------



## TrollDragon

mikelap said:


> Everytime before cutting  i always look at this picture i took.Better safe then sorry.and i use a cutter more control . Arrows show pins to be cutoff.


Thanks MIKELAP I'll keep the picture handy. 

The rigid cut off disk worked perfectly, it's one of those little stone disks as round as your thumb that requires a mandrel.

With it cutting so flush you don't need any tape on the tube.

Now I just have to be careful plugging it in, with the missing pins it has no key now.


----------



## TrollDragon

That's right gibosi your using the 6DJ8's, I had it in my mind your were using a 12A?7 type tube. So all that heater stuff doesn't apply...

Well I'm batting 0 for 2 tonight, I guess it's time to just listen a little Genesis before bed, "Foxtrot" I'm thinking will suffice.


----------



## TrollDragon

On a lighter note I have 4 Svetlana 6Ж5П's on their way from Sofia, another 3 week wait...


----------



## Audiofanboy

trolldragon said:


> Hey AFB!
> 
> MIKELAP sent me a picture of what is your MK IV SE's board section, there is a Linear 1084 modded in on a heat sink. Is this stock or a mod you have done? Possibly a CCS implementation? The input caps are missing as well. Do you have any full pics of the board?


 
  
 Linear 1084? Heat sink? Modding? Nope, not me lol, my IV SE is pretty much stock!


----------



## gibosi

mordy said:


> Hi Gibosi,
> 
> "Ah yes, it appears you have a pair of Toshiba-made 6CS6. These are nice tubes. "
> 
> ...


 
  
 Mordy,
  
 Oskari made a pretty very convincing case that these 6CS6 were manufactured by Toshiba. But of course, it is certainly possible that there was some kind of connection between Toshiba and Hitachi at that time....
  
 http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/2655#post_9756591


----------



## TrollDragon

audiofanboy said:


> Linear 1084? Heat sink? Modding? Nope, not me lol, my IV SE is pretty much stock!


 
  
 No problem good sir, this was the pic in question. 
	

	
	
		
		

		
		
	


	




 

 The TO-220 case LT1084 surrounded by the thick white silk screening there has been moded to fit.
 It's a 5V 7.5A Low Drop Out Regulator that will keep Vout constant down to a 1V Vin/Vout differential.
 Installed as a Constant Current Regulator possibly, or just a more effiecent 5V regulator most likely.
  
 Anyway, as they say "Inquiring minds want to know..."





 
  
 Edit: Update I found the picture, should have done a reverse Google first... It's eboy2003's MK IV from 5 years ago which has a different board than mine, probably a very early revision.
  
Here is the thread where the pictures come from and he has done some interesting mods, I'll have to give it a read through.
  
 I just put the sudo repaired 6AV6 in and I am going for coffe and a smoke before I light it up and see if there is any flames.


----------



## hypnos1

Update on the 6HM5s (Yugoslavia?!)...
  
 Despite the blinding flashes still on start-up(!) - but with no obvious ill-effects after 50+hrs - these have definitely knocked the RCA 6DT6As off their perch. Initial reservations have been totally kicked into touch. I have now become an avid fan of really wide and deep soundstage, even though I thought it at first a rather less "intimate" sound. I love the 'airiness' and clarity these babies are putting out. And the range and 'cleanliness' of treble notes, coupled with extra instrument separation is truly a revelation. This separation probably also explains my initial doubts over bass response - what I thought may be a negative, ie less perceived 'slam', I now realise may be down to a much more subtle reproduction of different TYPES of lower frequency...ie a nice spread, rather than 'bunched', which at first can seem less weighty.  Perhaps these tubes are not for heavy head-banging - unless you turn that knob right up! Then again, I am a firm believer that less is more as far as bass is concerned - there are so many fine, detailed things going on in a really well-recorded piece of music that it is bordering on the criminal to overpower them indiscriminately...just my personal thoughts, that is...But despite my ramblings, please don't get the wrong impression - bass is lovely and rich from these tubes. Give 'em a try! And the beauty of these also is they are just "plug 'n play" (EF95).
  
 Happy rolling.


----------



## Oskari

mordy said:


> I have a pair of Raytheon 6DT6A made in Japan plus the Siemens Foreign  EH90 and Haltron 6CS6. They all look like they were made in the same factory. Since we know know that there is a connection between Hitachi and Raytheon, how can you know if all these tubes were made by Hitachi and not by Toshiba? (Perhaps Toshiba made them for Hitachi when it comes to the Raytheon tubes?)


 
  
 How does one know anything for certain? 
	

	
	
		
		

		
		
	


	



  
 Photos please!
  
 The Raytheon–Hitachi relationship hardly precluded Raytheon from selling tubes from other sources.


----------



## Sony Slave

I have a general question, what is the most detailed and dynamic tubes out there for the Little Dot 1+?
 Tubes that blow the ones mentioned in the original guide out of the water.
  
 I would like mod-less, to easy to mod tubes if possible.
  
 Any ideas?


----------



## gibosi

sony slave said:


> I have a general question, what is the most detailed and dynamic tubes out there for the Little Dot 1+?
> Tubes that blow the ones mentioned in the original guide out of the water.
> 
> I would like mod-less, to easy to mod tubes if possible.
> ...


 
  
 I will suggest a couple, and I am sure others have more to add.
  
 6AV6 (and 6AT6 and 6AQ6) These are easy to mod, just cut off pins 5 and 6 and use the EF92 setting. The best tubes are those with a box-like structure (a box getter) on top of the mica:
  
 http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/3285#post_9859647
  
 6HM5 / 6HA5 / EC90
  
 No mods required. Use the EF95 setting. You want to avoid the short squat tubes that look like the typical 6AK5, 
  
http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/3300#post_9862250
  
http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/3045#post_9828452


----------



## Oskari

gibosi said:


> 6HM5 / 6HA5 / EC90


 
  
 I'm sure you meant to write EC900. 
	

	
	
		
		

		
			




  
 EC90 = 6C4. A somewhat different tube.


----------



## Sony Slave

gibosi said:


> I will suggest a couple, and I am sure others have more to add.
> 
> 6AV6 (and 6AT6 and 6AQ6) These are easy to mod, just cut off pins 5 and 6 and use the EF92 setting. The best tubes are those with a box-like structure (a box getter) on top of the mica:
> 
> ...


 
  
 How does one switch to the EF92 or EF95 setting.
 Do you have to tinker with the internals a bit?
  
 I've asked this before from a fellow head-fier, but are there any good vendors you'd recommend as well from ebay.
  
 Thanks a bunch for the information too.


----------



## Artsi

There are pins inside little dot and you just put jumper between pins to get EF92 mode working.


----------



## MIKELAP

sony slave said:


> How does one switch to the EF92 or EF95 setting.
> Do you have to tinker with the internals a bit?
> 
> I've asked this before from a fellow head-fier, but are there any good vendors you'd recommend as well from ebay.
> ...


 
  
 Easiest and cheapest way if your on EF95 setting and you want EF92 you strap or join with a small wire pin hole 6 and 7 or 5-7 on your LD MK3 dont know if it works with other LD and there is also socket adaptors your amp has to be on EF92 setting you plug in the socket adaptor in the LD thats all that's $38.00 and comes from China or if you solder you could make your own .http://www.ebay.com/itm/300961753333?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1438.l2649


----------



## Sony Slave

mikelap said:


> Easiest and cheapest way if your on EF95 setting and you want EF92 you strap or join with a small wire pin hole 6 and 7on your LD MK3 dont know if it works with other LD and there is also socket adaptors your amp has to be on EF92 setting you plug in the socket adaptor in the LD thats all that's $38.00 and comes from China or if you solder you could make your own .http://www.ebay.com/itm/300961753333?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1438.l2649


 
  
 I ordered the Little Dot 1+ 





, maybe it's the same process, perhaps someone else can give us a heads up on the info.....


----------



## MIKELAP

sony slave said:


> I ordered the Little Dot 1+
> 
> 
> 
> ...


 
  
 If you look on page 77 it list compatible amp with the tube we are using the LD1+ is there you could try it anyways i made mistake regarding jumpers and amp is still ok so i guess if you can use these tubes you can do the wire mod to your amp or what i just receive are longer jumpers way easier to change now heres a picture


----------



## Sony Slave

Can you guys make me a video on how to change the EF settings, instructional photos, or at least a drawing slide show of some sort?
  
 I am not tech savy what so ever.


----------



## MIKELAP

i marked the jumper location in red for you if you magnify picture you will see better
                                                                                                                                                                
  
   you see the red rectangle right of the volume right below its marked EF92 AND THERES 2 PINS thats your EF92 jumper the other one IS NEXT TO THE RED SQUARE and the bottom to the left there to its marked EF92 THOSE ARE THE LEFT AND RIGHT CHANNEL JUMPERS. for the other jumpers i see 2 other jumpers but its marked J3 so those must be your EF95 JUMPERS i dont see any other unless you see an EF95 inscription somewhere i dont . so those jumpers are right in the middle of the board.to the left of the opamp so i would SAY that according to the picture the amp is set on EF95 setting because jumpers are on the 2 pins get it so in this case to have the EF92 SETTING you remove the jumpers from J3 or EF95 and put them on EF92 JUMPERS . I hope its clear .


----------



## Sony Slave

mikelap said:


> you see the red rectangle right of the volume right below its marked EF92 AND THERES 2 PINS thats your EF92 jumper the other one IS NEXT TO THE RED SQUARE and the bottom to the left there to its marked EF92 THOSE ARE THE LEFT AND RIGHT CHANNEL JUMPERS. for the other jumpers i see 2 other jumpers but its marked J3 so those must be your EF95 JUMPERS i dont see any other unless you see an EF95 inscription somewhere i dont . so those jumpers are right in the middle of the board.to the left of the opamp so i would SAY that according to the picture the amp is set on EF95 setting because jumpers are on the 2 pins get it so in this case to have the EF92 SETTING you remove the jumpers from J3 or EF95 and put them on EF92 JUMPERS . I hope its clear .


 
  
 lol That helped a ton. Now i'll know exactly what to do when my little dot 1+ ships in.
  
 thank you.


----------



## TrollDragon

mikelap said:


> EF92 jumper the other one IS NEXT TO THE RED SQUARE


 

 I don't see no jumpers in Red Square...


----------



## mordy

Relevance: 0
 However, this picture of a tired red square cyclist on the Red Square is good for a laugh. Perhaps the red nose indicates the reason for sleeping.....


----------



## TrollDragon

Well the clear top NEC 6AV6's are working very nicely in the LD despite my pin mishap...

  
  


Spoiler: Then you plug it in and the Magic Happens!






  
 These sound good to me, I don't have the descriptive ear that the rest of you have, if anything they might have a bit too much treble and not quite enough bass for my liking.
 It would be good to find a pair of 6AV6's with the box on top to compare with these NEC ones.
  
 These 6AV6's are one of the prettiest tubes when lit up in the amplifier.


----------



## TrollDragon (Jul 17, 2020)

Deleted due to foolishness.


----------



## gibosi

trolldragon said:


> Well the clear top NEC 6AV6's are working very nicely in the LD despite my pin mishap...
> 
> 
> These sound good to me, I don't have the descriptive ear that the rest of you have, if anything they might have a bit too much treble and not quite enough bass for my liking.
> It would be good to find a pair of 6AV6's with the box on top to compare with these NEC ones.


 
  
 These strongly resemble a newer RCA 6AV6 and your description also fits well. In my experience, the RCA 6AV6 is the brightest and most forward of the 6AV6s.
  
 In your search for 6AV6 with box getters, don't forget the 6AT6 and 6AQ6. The main difference is heater current, and in my experience (Sylvania and RCA), they sound the same.


----------



## Artsi

trolldragon said:


> Well the clear top NEC 6AV6's are working very nicely in the LD despite my pin mishap...


 

  
 Here is better picture of what's inside -91 westinghouse tubes. As you can see they look identical with NEC 6AV6. I think that this dryness and sharpness in sound makes them sound more forwarding. I personally prefer just a little smoother sound. With box on the top etc types of 6AV6 could be older models and they can have smoother tube sound.
  
 This tube rolling is like wine tasting. You have many excellent tubes and try to tell and explain tiny differences to the others.


----------



## GCooper

6BE6 Status Report--
  
 After a few hundred hours of burn-in, my Soviet 6BE6 tubes are running at an average temperature of 135F (after two hours of run time) with an ambient air temperature of 62F. LDIII Case near the front tubes is ~88F. The rear tubes run much hotter-near 280F at top.
  
 Given my tastes in music (vocals, jazz, folk) I am not sure it makes sense to look further. Sound is crisp, good separation, excellent tone, very full but not booming. Probably not a good choice for Metallica or Queen, but otherwise worth a go. I experience lower listening fatigue than with the stock tubes. Using the Turtle Beach DSS2 as an audio source is working very well. Surround Sound is smoother through the LDIII than listening directly from the DSS2.
  
 My main concern with using the heptodes was that they might pick up the signal from the AM station transmitter that resides a few hundred yards from my house. This does not happen, so these will continue to remain in use until they go bad and another pair of 6BE6 fill that space.


----------



## gibosi

artsi said:


> Here is better picture of what's inside -91 westinghouse tubes. As you can see they look identical with NEC 6AV6. I think that this dryness and sharpness in sound makes them sound more forwarding. I personally prefer just a little smoother sound. With box on the top etc types of 6AV6 could be older models and they can have smoother tube sound.
> 
> This tube rolling is like wine tasting. You have many excellent tubes and try to tell and explain tiny differences to the others.


 
  

  
 For comparison, a pair of RCA 6AV6. The NEC and Westinghouse would seem to be identical.


----------



## KimChee

I have my MK III with M8100, and they sound excellent, but does anyone tube roll on the Old Little Dot II?  EF92 family, wonder if it would even be worth it.


----------



## hypnos1

kimchee said:


> I have my MK III with M8100, and they sound excellent, but does anyone tube roll on the Old Little Dot II?  EF92 family, wonder if it would even be worth it.


 
  
  
 Hi Kim.
  
 If you're interested, before I fell in love with the (tall-tubed) 6HM5s - which need EF95 setting - I was in love with the RCA 6DT6As which were then, and still are, excellent tubes on EF91/2 setting...
  
 Cheers


----------



## gibosi

In addition to the 6DT6A, the 6AV6 (and sister tubes, 6AT6 and 6AQ6) can also be used in the EF92 setting. However, to use these tubes, it is necessary to cut off pins 5 and 6. So yes, there are a number of very fine tubes that can be used in your LD II.
  
 And in fact, these tubes would also sound great in your LD III, maybe even better than your M8100. And I would also encourage you to try the tall-tubed 6HM5 in your LD III as well.


----------



## gibosi

While on the subject of 6AV6 (and sister tubes 6AT6 and 6AQ6), this appears to be a pair of early made-in-Holland Philips/Amperex 6AT6 (EBC90):
  
 http://www.ebay.com/itm/2-Rogers-by-Philips-6AT6-EBC90-Vacuum-Tube-Tested-NOS-NIB-Holland-/121188957031?pt=Vintage_Electronics_R2&hash=item1c376cbb67


----------



## siles1991

hi guys been really busy at work. been working almost 12-14 hours a day I'm so exhausted. thank you so much to everyone who replied me I really appreciate it. ATM I'm looking at Sylvania 6HM5 but the cheapest postage I can find is 12usd to Malaysia for a single tube...really really expensive


----------



## MIKELAP

trolldragon said:


> I don't see no jumpers in Red Square...


 
  
 Funny man ,.you dont see him because he already jumped !


----------



## MIKELAP

mordy said:


> Relevance: 0
> However, this picture of a tired red square cyclist on the Red Square is good for a laugh. Perhaps the red nose indicates the reason for sleeping.....


 
  
 Thats the kind of explanation i would like to get with pictures related to the socket mod for the double triode mod because there still things that are not clear related to soldering pins and deactivating the same pins at the base dont know what that means exactly . When somebody has the full picture and pictures it will be great meanwhile stocking up on equipement to do this thing.and practicing my soldering


----------



## Artsi

kimchee said:


> I have my MK III with M8100, and they sound excellent, but does anyone tube roll on the Old Little Dot II?  EF92 family, wonder if it would even be worth it.


 
  
 Did you mean the original MK II from 2005? After that have came II+, II++ and now again II. Mine have v2.0 circuitboard and it has built-in support for the 6H30 powertubes.


----------



## mordy

Hi Oskari,
  
 I tried to take pictures of the Siemens EH90 Foreign, Haltron 6CS6 and the Raytheon 6DT6A. All these tubes are made in Japan. It seems very clear that the Siemens EH90 and Haltron 6CS6 are identical. The Raytheon looks to have similar construction, but a little different.
 Note: The Siemens box says EH90/6CS5. The 6CS5 is an error, since that is an octal tube - it should read 6CS6.
  
 First a picture of the boxes and the tubes. The markings have worn off the Siemens tube from use.

 The boxes are all different sizes and probably made in the countries where they were sold. Note error on Siemens box.

 Closeup of the bottom mica and wires coming from the pins

 Ditto

 The rectangular holes in the plate are identical in the first two tubes; the Raytheon hole has a drop more height.

 Top mica Haltron

 Ditto

 Top mica Siemens

 Raytheon 6DT6A tube. Markings are P14 and underneath 3K. Anybody knows what it means?

 Could not get a good shot of the top mica on the Raytheon.

 Ditto

  
 The Raytheon is my best sounding 6DT6 tube. The other two are also very nice sounding tubes. I believe that there were three major Japanese tube manufacturers: Toshiba, Matsushiita and Hitachi.  Oskari thinks that the first two are made by Toshiba. Regarding the Raytheon I will rely on Oskari's opinion because he has much better eyesight than me (screen resolution?) and he has the ability to identify the different clues. (If you want more pictures or different views let me know).
  
 Amazing how the Phillips ghost is evident in all the Japanese, Yugoslavian and Australian tubes.....


----------



## gibosi

mikelap said:


> Thats the kind of explanation i would like to get with pictures related to the socket mod for the double triode mod because there still things that are not clear related to soldering pins and deactivating the same pins at the base dont know what that means exactly . When somebody has the full picture and pictures it will be great meanwhile stocking up on equipement to do this thing.and practicing my soldering.


 
  
 Hope this explanation will help a bit....
  
 When we insert a 9-pin 6DJ8 or 6BQ7A into a 7-pin adaptor, we have the following:
  
 Tube pin assignment  -> unmodified adapter  -> Little Dot pin-hole assignment
  
 Tube pin 8 (cathode) -> pin-hole 7 (screen/suppressor grid)
 Tube pin 7 (grid)  -> pin-hole 6 (screen/suppressor grid)
 Tube pin 6 (plate) -> pin-hole 5 (plate)
 Tube pin 5 (heater) -> pin-hole 4 (heater)
 Tube pin 4 (heater) -> pin-hole 3 (heater)
  
 We are fortunate that tube pins 4, 5 and 6 line up perfectly. However, we are not so lucky with tube pins 8 and 7. The Little Dot assigns the grid to pin-hole 1, not pin-hole 6; and the cathode to pin-hole 2, not pin-hole 7.
  
 So we modify the adapter. We connect tube pin 8 (adapter pin 7) to adapter pin 2 to reroute the cathode to pin-hole 2, and tube pin 7 (adapter pin 6) to adapter pin 1 to reroute the grid to pin-hole 1.
  
 Now that adapter pins 2 and 7 are connected and pins 6 and 1 are connected, we do not want pins 6 and 7 to extend out of the bottom of the adapter and into pin-holes 6 and 7 in the Little Dot socket. So we cut them a bit short. When you look at the bottom of the adapter, you will see only 5 pins, as the other two have been shortened.
  
 Hope this helps. 
  
 PS: Very frankly, it was quite a struggle to put my adapters back to together after modification, but everything is working perfect. Therefore, I am very reluctant to take them apart in order to take pictures as I don't want to risk breaking them somehow. (>_<)


----------



## Oskari

mordy said:


> I tried to take pictures of the Siemens EH90 Foreign, Haltron 6CS6 and the Raytheon 6DT6A. All these tubes are made in Japan. It seems very clear that the Siemens EH90 and Haltron 6CS6 are identical. The Raytheon looks to have similar construction, but a little different.
> ...
> Oskari thinks that the first two are made by Toshiba. Regarding the Raytheon I will rely on Oskari's opinion because he has much better eyesight than me (screen resolution?) and he has the ability to identify the different clues.


 
  
 Thanks for the photos! I think that they were all made by Toshiba. That they _probably_ were.
  
 You are right that the Raytheon-branded tube is a bit different but it is still quite similar.
  
 You can see a Hitachi-branded 6DT6A here:
  

http://goods.ruten.com.tw/item/show?11091126878173
  
 The differences between these two seem more pronounced to me.


----------



## mordy

Hi Oskari,
  
 Thanks for your comments.Yes, it does look quite different. So Toshiba it is.
  
 BTW: Is that price of $50 in USD?


----------



## TrollDragon

The Haltron 6CS6's are running now with the switches in 2-7, the sound is so much better that the NEC 6AV6's and the bass is back!
 I am going to try 1-7 / NS / 2-7 on my switches and see which one I like the best.


----------



## MIKELAP

gibosi said:


> Hope this explanation will help a bit....
> 
> When we insert a 9-pin 6DJ8 or 6BQ7A into a 7-pin adaptor, we have the following:
> 
> ...


 
  
 Come on gibosi take them apart please 
	

	
	
		
		

		
		
	


	




 lol just kidding i manage to put them back together once in less than 5 minutes tried again later coulndt do it this is a job for the morning when i have patience thanks alot for the explanation ill assimilate that tonight and think about it tomorrow .ill take the pictures when i do the mod and post them after waiting for my tubes and my third hand only got two at the moment not enough .


----------



## Oskari

mordy said:


> BTW: Is that price of $50 in USD?


 
  
 I guess it's Taiwanese money.


----------



## Acapella11

trolldragon said:


> I have converted the table on page 77 to Excel & Open Office formats if anyone wants the table locally on their machine.
> I will try to keep the files updated when future table changes occur.
> 
> Excel XLS format.
> ...


 
  
 Good idea to convert the table.
  
 Since I put a little bit of effort into this, a PM instead of hostile takeover would have been nice, especially considering there aren't even any new types of tubes.


----------



## siles1991

trolldragon said:


> I have converted the table on page 77 to Excel & Open Office formats if anyone wants the table locally on their machine.
> I will try to keep the files updated when future table changes occur.
> 
> Excel XLS format.
> ...


 
  
 how about opening a google doc IIRC it has live update so once you update everyone can see it without the need to keep on downloading a new file.


----------



## TrollDragon

acapella11 said:


> Good idea to convert the table.
> 
> Since I put a little bit of effort into this, a PM instead of hostile takeover would have been nice, especially considering there aren't even any new types of tubes.


 
  
 Sorry, I presumed it would be handy converting the table and I really should have asked first, it was late when I created the post and could have worded it better with proper credit given. I am by no means taking over all your excellent hard work and putting the links to the files in my signature was an easy reference for those wanted them. I have since removed the sig links and I will also remove the dropbox files if you so wish.
  
 I sincerely didn't mean to step on any toes here.
 My most humble apologies.


----------



## mordy

Hi Oskari,
  
 You are right, Taiwanese dollars. $50 TWN looks scary, but it is only USD $1.70


----------



## Acapella11

trolldragon said:


> Sorry, I presumed it would be handy converting the table and I really should have asked first, it was late when I created the post and could have worded it better with proper credit given. I am by no means taking over all your excellent hard work and putting the links to the files in my signature was an easy reference for those wanted them. I have since removed the sig links and I will also remove the dropbox files if you so wish.
> 
> I sincerely didn't mean to step on any toes here.
> My most humble apologies.


 
  
 Don't remove the files. I think it's good if they are accessible for everyone. I would have appreciated if you would have asked, this is nice just out of respect for the work. I might have not even minded. 
  
 I am not as active in the thread anymore anyways and I support progress. If you fancy improving it, why not. As you can see in the table, I have tried to keep members acknowledged for their findings. That's just how I work. So, what I would appreciate is to include a note / acknowledgement of my posting on page 77.
 Keep the the good spirit.


----------



## TrollDragon

acapella11 said:


> Don't remove the files. I think it's good if they are accessible for everyone. I would have appreciated if you would have asked, this is nice just out of respect for the work. I might have not even minded.
> 
> I am not as active in the thread anymore anyways and I support progress. If you fancy improving it, why not. As you can see in the table, I have tried to keep members acknowledged for their findings. That's just how I work. So, what I would appreciate is to include a note / acknowledgement of my posting on page 77.
> Keep the the good spirit.


 
  
 I will put the well deserved credit at the top of the files and a link to the table on page 77 which I should have done when I converted the table.
 This is why I shouldn't do things when I should be in bed.


----------



## kvtaco17

GE 6AV6 came in today! Trimmed some pins and threw the lil amp in EF92, burning in as I type!


----------



## kvtaco17

gibosi said:


> I had a chance to listen to the HD800 (300 Ohms) recently, and like you, I thought it sounded fine on my LD1+. And I have been I wondering how much of this is a direct function of the installed op amp? Or is it more complicated? For example, the technical info for the LME49990 op amp explicitly states that it "Easily Drives 600Ω Load." I didn't try the HD 800 with the stock op amp, so I have no idea if that would have made any difference....
> 
> Unfortunately, the best I DAC I have used with the LD1+ is the Schiit Modi, so can't add anything....


 
 tried the stock op amp and it sounded congested and weird the LME 49990 and OPA627AP sound good... volume was ok with all 3...


----------



## Sony Slave

gibosi said:


> As long as you use stranded wire, everything will be fine. I was shoving tubes in and out of my LD like a mad man and using solid core wire. It takes time and a lot of rolling to do any real damage. So by all means, use 26 gauge, or smaller stranded wire, and enjoy them.
> 
> Oh, there is very little current passing through this wire, measured in milliamps at most. A very tiny wire is more than sufficient.
> 
> ...


 
  
 So you simply wrap solder wire around the pins and solder them on?
 By doing this you are strapping the pins right.


----------



## gibosi

sony slave said:


> So you simply wrap solder wire around the pins and solder them on?
> By doing this you are strapping the pins right.


 
  
 Yes.
  
 Obviously, there are two ways to strap. You can strap the tube itself. Or you can strap in the socket.
  
 Soldering wire to the pins modifies the tube itself and is a very durable and permanent mod. Dropping 26 gauge, or smaller, stranded wire into the socket pin holes before inserting the tube is very temporary. Either way is fine. It is entirely up to you.


----------



## Sony Slave

gibosi said:


> Yes.
> 
> Obviously, there are two ways to strap. You can strap the tube itself. Or you can strap in the socket.
> 
> Soldering wire to the pins modifies the tube itself and is a very durable and permanent mod. Dropping 26 gauge, or smaller, stranded wire into the socket pin holes before inserting the tube is very temporary. Either way is fine. It is entirely up to you.


 
  
 ok. I then.
  
 I have an off topic question, does the Little dot 1+ sound worse than the MKiii and iv? 
  
 Even though I have low impedance cans (SRH840's), i'm just wondering if I am missing out on anything.


----------



## Edgard Varese

sony slave said:


> ok. I then.
> 
> I have an off topic question, does the Little dot 1+ sound worse than the MKiii and iv?
> 
> Even though I have low impedance cans (SRH840's), i'm just wondering if I am missing out on anything.


 
  
 The Mk iii and iv are not really suitable for low impedance cans (see their output specifications on the Little Dot site) as they put out less power as the impedance load decreases.  Plus those amps have a high output impedance which does not play nice with low impedance cans (poor damping).  The I+ is much more suitable for low impedance headphones.


----------



## Sony Slave

edgard varese said:


> The Mk iii and iv are not really suitable for low impedance cans (see their output specifications on the Little Dot site) as they put out less power as the impedance load decreases.  Plus those amps have a high output impedance which does not play nice with low impedance cans (poor damping).  The I+ is much more suitable for low impedance headphones.


 
  
 Thank you, do you also happen to know tubes that have amazing mids? As I stated before I want the tubes to be better than what the original guide has to offer. But I would like the tubes to be mod-less to easy to mod.
  
 Thank you.


----------



## Edgard Varese

sony slave said:


> Thank you, do you also happen to know tubes that have amazing mids? As I stated before I want the tubes to be better than what the original guide has to offer. But I would like the tubes to be mod-less to easy to mod.
> 
> Thank you.


 
  
  
 It's hard to beat those 6DT6As (either GE or RCA, I have both) for WOW factor, but heptodes are nice too (6BE6 and related tubes... see page 77 of this thread for a handy chart).  My own view is that the frequency range of the heptodes is a little more balanced than the 6DT6As (which extend both the treble and bass in my experience), so you might find the heptode mids a bit more pleasing (if less exciting out of the box).


----------



## kvtaco17

edgard varese said:


> It's hard to beat those 6DT6As (either GE or RCA, I have both) for WOW factor, but heptodes are nice too (6BE6 and related tubes... see page 77 of this thread for a handy chart).  My own view is that the frequency range of the heptodes is a little more balanced than the 6DT6As (which extend both the treble and bass in my experience), so you might find the heptode mids a bit more pleasing (if less exciting out of the box).


 
 I'd look at the EH90 (Mullard/Valvo/Ediswan/ect.) for some sweet mids... I personally love these tubes! The 6DT6 family would be something else to check out (currently my favorite) as well as the 6AV6 (evaluating right now and liking a lot so far)


----------



## joseph69

Hey guys, I've had the LD1+ for about 3-4 months now and I have a pair of 6AK5W tubes which cam with it as an upgrade and I also purchased a pair of Voskhod 6J1P-EV tubes which I've listened to for most of the time I've had the amp. I was going to (and still may) purchase the MAD ear+HD but I was reading a thread today where they compared the LD1+, Asgard and the Ear+HD and found that people were changing their op-amps and trying all different types of tubes, so I thought since I have the LD why not try this before jumping into the Ear+HD. I read that a lot of people really like the Burr Brown OPA2107 by Texas Instruments so I ordered one tonight and it will be here soon. I like the way the LD sounds now, but I recently purchased the RS1i's and would like hear some different sound choices with them. I really like crystal clear clarity, crisp highs and detail. Can anyone please give me some advice on some tubes I can purchase for this sound,  and that also match well with the RS1i's and the OPA2107, this way I can order them so they will arrive about the same time. I think I should do some experimenting with the LD being that there seems to be so many options for this great little amp, but I really don't where to start, so I figured I'd try a different op-amp to start with.
 BTW I probably didn't even let the 6AK5W's burn-in before changing them to the Voshods. I would have to say that I have close to100hrs on these tubes by now and the amp does sound nice to me, but like I said, I want to step it up a bit and possibly hear its full potential especially with the RS1i's.Thank you.


----------



## gibosi

joseph69 said:


> ....... I read that a lot of people really like the Burr Brown OPA2107 by Texas Instruments so I ordered one tonight and it will be here soon. I like the way the LD sounds now, but I recently purchased the RS1i's and would like hear some different sound choices with them. I really like crystal clear clarity, crisp highs and detail. Can anyone please give me some advice on some tubes I can purchase for this sound,  and that also match well with the RS1i's and the OPA2107, this way I can order them so they will arrive about the same time. I think I should do some experimenting with the LD being that there seems to be so many options for this great little amp, but I really don't where to start, so I figured I'd try a different op-amp to start with.


 
  
 I would also recommend that you try the LME49990 and/or OPA627AP. To my ears, these are both superior to the OPA2107.
  
 And these tubes just might do the trick:
  
 - GE (Made in Gt Britain by Mullard) or Ei (Made in Yugoslavia) 6HM5 (also listed as 6HA5 and EC900). Set your LD for EF95 tubes. Avoid the small squat tubes that look like 6AK5. Look for the taller tubes.
  
  
 Example listings to show what these tubes look like:
  
 GE / Mullard 6HM5
  
 http://www.ebay.com/itm/VINTAGE-GE-6HM5-6HA5-BLACKBURN-MULLARD-MADE-VACUUM-TUBE-TESTED-AUDIO-RADIO-/270927668081?pt=Vintage_Electronics_R2&hash=item3f148c2371
  
 Ei 6HM5
  
 http://www.ebay.com/itm/6HM5-6HA5-EC900-export-quality-audio-triode-tube-NOS-FREE-SHIPPING-/300879467071?pt=Vintage_Electronics_R2&hash=item460dd0523f

  
 Happy tube rolling!


----------



## kvtaco17

gibosi said:


> I would also recommend that you try the LME49990 and/or OPA627AP. To my ears, these are both superior to the OPA2107.
> 
> And these tubes just might do the trick:
> 
> ...


 
 I also endorse this advice!
  
 If you like your 2107 and would like better separation and more refinement I's scoop up the OPA627AP. Though the LME 49990 is amazing also!
  
 Tube wise I'd concur BUT I'd also add the Sylvania (more neutral and dynamic) and RCA (warmer) 6DT6A and the GE 6AV6 (make sure it has the box on top of the mica (it makes a big difference and I can provide pics if you need to see what I mean)  All of these are very detailed and will give a very large sound stage (especially the 6AV6)


----------



## Sony Slave

kvtaco17 said:


> I also endorse this advice!
> 
> If you like your 2107 and would like better separation and more refinement I's scoop up the OPA627AP. Though the LME 49990 is amazing also!
> 
> Tube wise I'd concur BUT I'd also add the Sylvania (more neutral and dynamic) and RCA (warmer) 6DT6A and the GE 6AV6 (make sure it has the box on top of the mica (it makes a big difference and I can provide pics if you need to see what I mean)  All of these are very detailed and will give a very large sound stage (especially the 6AV6)


 
  
 Please provide pics!


----------



## joseph69

gibosi said:


> I would also recommend that you try the LME49990 and/or OPA627AP. To my ears, these are both superior to the OPA2107.
> 
> And these tubes just might do the trick:
> 
> ...


 
 Thank you for your reply and for giving me some advice on the different op-amps and some different tube to try. I'm going to order these op-amps and tubes today. Thanks again!


kvtaco17 said:


> I also endorse this advice!
> 
> If you like your 2107 and would like better separation and more refinement I's scoop up the OPA627AP. Though the LME 49990 is amazing also!
> 
> Tube wise I'd concur BUT I'd also add the Sylvania (more neutral and dynamic) and RCA (warmer) 6DT6A and the GE 6AV6 (make sure it has the box on top of the mica (it makes a big difference and I can provide pics if you need to see what I mean)  All of these are very detailed and will give a very large sound stage (especially the 6AV6)


----------



## gibosi

sony slave said:


> Please provide pics!


 
  
 A pair of GE 6AV6. Notice the box-like structure on top of the mica. These are the ones you want to look for.


----------



## MIKELAP

gibosi said:


> A pair of GE 6AV6. Notice the box-like structure on top of the mica. These are the ones you want to look for.


 
 I also notice on my SYLVANIA 6BJ6 tubes that little box atop the mica.


----------



## mordy

Here are my Sylvania side getter clear top  box getter tubes. Later models do not have the box and the the dish on top, but instead have a regular top getter and top getter flash.
 I asked my retired engineer friend why earlier models have the box and the dish, and he thought that these serve for heat dissipation.
 Seems that the best sounding 6AV6 tubes have the box construction.


----------



## Artsi

No more playing with strap-wires or dipping jumpers! This little fix makes tube rolling so much easier. \o/ This was possibly only place to put switches in MK II.
  
 Thanks Trolldragon for easy wiring-diagram. 1. switch EF95-EF92 and 2. switch 2/7-off-1/7.


----------



## TrollDragon

artsi said:


> No more playing with strap-wires or dipping jumpers! This little fix makes tube rolling so much easier. \o/ This was possibly only place to put switches in MK II.
> 
> Thanks Trolldragon for easy wiring-diagram. 1. switch EF95-EF92 and 2. switch 2/7-off-1/7.


 
 You are most welcome, enjoy the _*Ease of Switching!*_ 
	

	
	
		
		

		
			




 The two switches look very nice up front and there is no room in the back at all from pictures I've seen. Also the bottom comes off your LD which would have made the install so much easier.
 Nice Job Artsi!




  
 I used 2 SPST and 2 SPDT (Center Off)  switches in case I might want to try each side with different tubes. The chance of that happening is probably slim but the option is there if I want it.
 Drawing DPDT and DPST's would have made the wiring diagram more confusing for some who wanted to try it.


----------



## kvtaco17

Received some Sylvania 6HA5 US made tubes today. They are burning in now. The GE6AV6's seem to have settled I'm going to give them another 10hours of use before I write impressions to be sure. Probably some time this week I'll write these up and compare them with the 6DT6 family.


----------



## Acapella11

kvtaco17 said:


> I'd look at the EH90 (Mullard/Valvo/Ediswan/ect.) for some sweet mids... I personally love these tubes! The 6DT6 family would be something else to check out (currently my favorite) as well as the 6AV6 (evaluating right now and liking a lot so far)


 
  
 The Raytheon 6BE6W I have are not as exciting / hard sounding, more gentle and "english" but one of their traits is that they are very holographic and large staged, which is not surpassed by the Valvos. In some ways they sound high end, in some systems they may not have the right environment to show it. They may only sound "boring / dark" in a non-matching system. This is why they match well with 6H30P tubes, which are reasonably bright and it opens them up in terms of stage. The refined treble warrants fatigue free listening and the bass is of good quality and quantity.


----------



## kvtaco17

acapella11 said:


> The Raytheon 6BE6W I have are not as exciting / hard sounding, more gentle and "english" but one of their traits is that they are very holographic and large staged, which is not surpassed by the Valvos. In some ways they sound high end, in some systems they may not have the right environment to show it. They may only sound "boring / dark" in a non-matching system. This is why they match well with 6H30P tubes, which are reasonably bright and it opens them up in terms of stage. The refined treble warrants fatigue free listening and the bass is of good quality and quantity.


 
 This could be a great example different amp implementation changing the final output of tubes. I have the MK1+ so I'm missing a pair of tubes because of my amps use of an opamp. I personally didn't care for the 6BE6W in my setup. The other difference would be my personal tastes. I tend to like lush mids with sparkly highs and punch tight bass. Another variable would be the cans we use. I have some variety BUT between my HD800, PS500 and AD2000x they all have a mid bass emphasis and fairly forward mids with accented treble (well minus the PS500)


----------



## gibosi

kvtaco17 said:


> Received some Sylvania 6HA5 US made tubes today. They are burning in now. The GE6AV6's seem to have settled I'm going to give them another 10hours of use before I write impressions to be sure. Probably some time this week I'll write these up and compare them with the 6DT6 family.


 
  
 I am looking forward to your impressions regarding the Sylvania 6HA5. As I already have some RCA/Siemens, GE/Blackburn and GE/??? 6AH5, I decided to wait for others to try the Sylvanias.... Thanks! 
  
 Besides, I have become so enamored with a pair of 1960 Amperex Bugleboy ECC88, that I am actively searching for other varieties. The 6DJ8 / ECC88 marketplace is very different than that of most of the non-traditional tubes we have been trying recently. For one thing, NOS/NIB tubes are often prohibitively expensive, so it is primarily a marketplace of used tubes. Even so, I have had to readjust my maximum price from $8/tube to $15/tube. Further, since these tubes are used, the vendor's measured test results are quite important. Tubes that test low have likely had a lot of use and thus can often be had rather cheaply. However a well-used tube may not last long, so I try to find tubes with test results that are close to new. Given this, so far I haven't even considered purchasing tubes that haven't been tested. After careful and patient searching, I have managed to stay below my limit and purchase some Mullard, Siemens, Tesla and Reflector tubes. Now all I have to do is wait....
  
 And hey! It feels pretty lonely here in 6DJ8 land! I think AFB has has gone even further afield into 12A?7 land? Am I really the only one here?? lol


----------



## mordy

Hi Gibosi,
  
 Could you describe the difference in sound between 6DJ8/ECC88 tubes compared to any (or all) of the best tubes from the 6AV6, 6AU6, 6AH6 or 6TD6 families?
  
 If there is a substantial improvement in sound I may consider taking the plunge and learn how to connect and solder all the wires, buying the tools, adapters and tubes etc.


----------



## TrollDragon

gibosi said:


> And hey! It feels pretty lonely here in 6DJ8 land! I think AFB has has gone even further afield into 12A?7 land? Am I really the only one here?? lol


 
 Sorry good sir, those tubes are a little too rich for my blood.
 I can enjoy rolling 6DJ8's vicariously through you.


----------



## Audiofanboy

gibosi said:


> I am looking forward to your impressions regarding the Sylvania 6HA5. As I already have some RCA/Siemens, GE/Blackburn and GE/??? 6AH5, I decided to wait for others to try the Sylvanias.... Thanks!
> 
> Besides, I have become so enamored with a pair of 1960 Amperex Bugleboy ECC88, that I am actively searching for other varieties. The 6DJ8 / ECC88 marketplace is very different than that of most of the non-traditional tubes we have been trying recently. For one thing, NOS/NIB tubes are often prohibitively expensive, so it is primarily a marketplace of used tubes. Even so, I have had to readjust my maximum price from $8/tube to $15/tube. Further, since these tubes are used, the vendor's measured test results are quite important. Tubes that test low have likely had a lot of use and thus can often be had rather cheaply. However a well-used tube may not last long, so I try to find tubes with test results that are close to new. Given this, so far I haven't even considered purchasing tubes that haven't been tested. After careful and patient searching, I have managed to stay below my limit and purchase some Mullard, Siemens, Tesla and Reflector tubes. Now all I have to do is wait....
> 
> And hey! It feels pretty lonely here in 6DJ8 land! I think AFB has has gone even further afield into 12A?7 land? Am I really the only one here?? lol


 
  
 Haha, no I'm still here and investigating double triodes in the shadows lol!
  
 Like you said, since the prices and the selling "pattern" of these tubes are quite different from what we're used to, it takes a leap of faith to actually buy anything. So, I've been taking my time with these tubes.
  
 While you've been a self-proclaimed "bottom feeder" of 6DJ8/ECC88 tubes, I've been trying to be a "middle feeder" of sorts, finding NOS or used but strong tubes from secondary manufacturers (EI, Matsushiita...) that used machinery from the best companies. Both for ECC88 tubes and 12AT7/ECC81, and even 12AX7/ECC83 (just as ridiculously expensive as some ECC88...).
  
 Apart from my free pair of Mullard Mitcham M8162/CV4024 (12AT7), I have a few pairs of NOS EI ECC88 made on Philips machinery, with the later "A-frame" getter, which cost me nowhere near a premium price 
	

	
	
		
		

		
		
	


	




; and I just managed to find a pair (hopefully identical, but still perfectly useful otherwise) of used and very strong EI ECC83 (12AX7) with the legendary "long smooth plates" made on Telefunken machinery! Still, like you said, even though I keep thinking I got a good deal for them, I still forked 24.50€ -shipped- for the pair... I guess, since they're double tubes, one could argue that I'm just at the 6€ or $8/triode limit lol!
  
 The latter is the good example of a pretty good deal you can get on ebay, without even looking that hard. These EI ECC83 had poor ad wording and no more silk screening on the tubes (no writings on tube apart from factory codes), so it took some googling to make sure what these were, and some eye squinting to read the factory codes; and as it is, I could only read the codes off of one tube. But sure enough, I saw the EI Nish factory, Yugoslavia, codes, and know for a fact that the tubes have those unmistakable Telefunken smooth long plates. So, it should turn out to be a good deal.


----------



## gibosi

mordy said:


> Hi Gibosi,
> 
> Could you describe the difference in sound between 6DJ8/ECC88 tubes compared to any (or all) of the best tubes from the 6AV6, 6AU6, 6AH6 or 6TD6 families?
> 
> If there is a substantial improvement in sound I may consider taking the plunge and learn how to connect and solder all the wires, buying the tools, adapters and tubes etc.


 
  
 In short, my LD with a pair of 1960 Amperex sounds better than it ever has. 
  
 The lows have good weight with superb detail and articulation. The mids are slightly warm and very clean, and the highs are crystal clear. Overall, they are very smooth, liquid, and musical. Details and sound stage are also exceptional. Against a black black background, the clarity and transparency is often breathtaking: Whispered lyrics, cymbal decay, details, details, details.... And the sound stage is wide and deep, with a real sense of space. You can hear the sound reverberating around the room, and instrument placement and separation is sharply etched and holographic. Again, my LD has never sounded this good....  I really like these tubes.....


----------



## Artsi

Got some different tubes today. 6AQ4 seems to have weird connection and is perhaps totally out of calculations. Other 6CS6 is with broken glass. Others seem to be with no visible problems. Westinghouse JAN CK 6AG5 -45 were so difficult to get out of box, that i put them in test. Got 6N6P-IR tubes yesterday as new powertubes. Russian seller was so nice that put 1 spare -IR tube in package.
  
 This is going to take long long... long time to manage all these.


----------



## TrollDragon

artsi said:


> Got some different tubes today. 6AQ4 seems to have weird connection and is perhaps totally out of calculations. Other 6CS6 is with broken glass. Others seem to be with no visible problems. Westinghouse JAN CK 6AG5 -45 were so difficult to get out of box, that i put them in test. Got 6N6P-IR tubes yesterday as new powertubes. Russian seller was so nice that put 1 spare -IR tube in package.
> 
> This is going to take long long... long time to manage all these.


 
 Nice!
 Much Fun!


----------



## MIKELAP

Srarted the socket mod man anybody that does this i congratulate its a pain in the wazoo. heres a picture of the disposition of the wires 7-2 and 6-1 very hard to get a decent picture they are not soldered yet just wanted to know if it would work like this keeping in mind to keep hole for screw in the middle clear of the wires  Thanks.Will save pictures for later when everything is done


----------



## TrollDragon

mikelap said:


> Srarted the socket mod man anybody that does this i congratulate its a pain in the wazoo. heres a picture of the disposition of the wires 7-2 and 6-1 very hard to get a decent picture they are not soldered yet just wanted to know if it would work like this keeping in mind to keep hole for screw in the middle clear of the wires  Thanks.Will save pictures for later when everything is done


 
 Now that is some heavy gauge wire, does the mod require such thick stuff?
 At least the socket is nice and big and easy to work on...
 Keep up the good work!
  
 On a soldering side note:
 I put a few of these together for sale last night, SOIC to 8 PIN DIP AD8620AR's.

 The SOIC chips are not too bad to solder, the TSOP's are not much fun though.


----------



## Artsi

This is how those 6AQ4 tubes look like:

 I can read from tube that it is CV2009 made in England. http://www.tubecollector.org/cv2009.htm It is normal 6AQ4 tube with that crap added on to bottom. Box says 6AQ4 CV417. Glass is not very clear and the other is nearly black. I managed to remove that crap and tubes works with LD.
  
 Another thing i have to say is that 7-1 strap does not seem to work right with MK II. It adds hum and buzz. And it comes stereo, so i don't think i have made anything wrong with switch-mod.


----------



## gibosi

trolldragon said:


> Now that is some heavy gauge wire, does the mod require such thick stuff?
> At least the socket is nice and big and easy to work on...
> Keep up the good work!


 
  
 I agree. I think your connecting wire is too thick. You want to wrap these wires around your pins very tightly, and it looks to me that this wire is a bit too thick and cumbersome to accomplish this with any ease. I use 30 gauge solid core wrapping wire and I would encourage you to give it a try.
  
 Cheers


----------



## gibosi

A small package arrived today with some Siemens and Mullard 6DJ8 / ECC88 tubes:
  
 Siemens. The tube codes indicate that these were manufactured in Siemens' Halske factory in 1970/71.
  

  
 Mullard. The tube codes indicate that these were manufactured in Mullard's Blackburn factory in 1970. As we have seen before, what is printed on the tubes can be misleading. One of these carries the CEI label and the other carries the Amperex Orange Globe label. However, they were manufactured in the same factory, within 3 months of each other. 
  

  
 These tubes tested almost new and I paid $14.33 each, including shipping. Or as AFB pointed out, since these are dual triodes, I paid only $7.16 per triode. lol  Either way, I believe I was able to procure some rather nice tubes while staying under my budget of $15/tube.


----------



## MIKELAP

Ya i know did not find 30 gauge wire settled for 22 gauge .What i tried instead of screwing around taking the adaptor apart i soldered wires on the exterior of the socket in the holes on top where the numbers are not pretty but alot alot less problematic now having a bit of a problem making solder stick to the metal what can be done for that. thanks.


----------



## gibosi

mikelap said:


> Ya i know did not find 30 gauge wire settled for 22 gauge .What i tried instead of screwing around taking the adaptor apart i soldered wires on the exterior of the socket in the holes on top where the numbers are not pretty but alot alot less problematic now having a bit of a problem making solder stick to the metal what can be done for that. thanks.


 
 This is what you are looking for:
  
 http://www.ebay.com/itm/like/300814518650?lpid=82
  
 In my local electronics store, they do no display this with regular wire. But if you ask specifically for "wrapping wire", I am quite sure that you can find it.


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## MIKELAP

What is the setting for double triodes EF-92 or EF95  .Thanks.


----------



## TrollDragon

mikelap said:


> Ya i know did not find 30 gauge wire settled for 22 gauge .What i tried instead of screwing around taking the adaptor apart i soldered wires on the exterior of the socket in the holes on top where the numbers are not pretty but alot alot less problematic now having a bit of a problem making solder stick to the metal what can be done for that. thanks.


The metal on the screw sections is old has has probably quite a bit of corrosion on it. Take the emery cloth to it and you should bring out the brass underneath. Then since it is fairly thick it will require a good deal of heat. Heat up the cleaned metal till the solder will melt by touching it to the metal and not the iron. Always have the metal hot enough to melt the solder.

I'll drop some 30AWG wirewrap wire in an envelope for you tomorrow. It needs to look good so you can do up the inside of the socket.


----------



## MIKELAP

trolldragon said:


> The metal on the screw sections is old has has probably quite a bit of corrosion on it. Take the emery cloth to it and you should bring out the brass underneath. Then since it is fairly thick it will require a good deal of heat. Heat up the cleaned metal till the solder will melt by touching it to the metal and not the iron. Always have the metal hot enough to melt the solder.
> 
> I'll drop some 30AWG wirewrap wire in an envelope for you tomorrow. It needs to look good so you can do up the inside of the socket.


 
 OK thanks for the tip .Dont bother i did them outside as long as they work ill try them like that .Thanks anyways should get my tubes tomorrow or the day after got that panavise vise today what a nice vise so versatile i love it.


----------



## i luvmusic 2

I just received the tubes that i ordered JAN GE 5654W,BRIMAR EF92,INTERNATIONAL/SYLVANIA 6AK5,MINIWATT/PHILIPS EF91 are this brand any good?


----------



## gibosi

mikelap said:


> What is the setting for double triodes EF-92 or EF95  .Thanks.


 
  
 EF95.


----------



## MIKELAP

This interest me since i run a pioneer sx750 interesting!  his comments are regarding the mk4SE        
  
Re: Little Dot Mk 9 

by *DavidZheZhe* » Sep 25th, '13, 06:35
  

 
 
 Re: Little Dot Mk 9 

by *DavidZheZhe* » Sep 24th, '13, 17:35



> Robbie California wrote:How would this compare with the LD MKIV SE version in terms of a headphone amp and would it be an improvement over the LD MKIVSE as a stereo preamp? Is there much in the way of upgraded parts compared to the IV SE or are they similar in that regard?


 
 For headphone usage sound is a littler purer due to no output capacitor in the signal path. For pre-amp usage, there's also protection from DC offset so that you can use it with any power amp (dc coupled as well)


----------



## TrollDragon

MK9 tubes seem to be between $20 - $50 for some NOS, lots of used cheaper.

Finally some protection on the preamp outs.

But for $530 your starting to creep into the "better" amp class, for the same price you can get a WooAudio WA3 which uses the 6080 & 2 6DJ8's stock.

Something to think about.


----------



## TrollDragon

artsi said:


> Another thing i have to say is that 7-1 strap does not seem to work right with MK II. It adds hum and buzz. And it comes stereo, so i don't think i have made anything wrong with switch-mod.


 
 Rollers here strap 1-7 with a socket wire on the MK II without noise, possibly try setting your switches to EF-95 & NS and then put a strap wire in 1-7 with the tubes to see if the hum returns.
 Also a 1-7 strap while in EF-92 mode might cause you some serious hum as well.
  
 I'd double check your wiring with a meter.


----------



## MIKELAP

Well got my 6BQ7A tubes this morning took a picture and pointed out what needs to get bent or cut is it the right pinsThanks.


----------



## gibosi

mikelap said:


> Well got my 6BQ7A tubes this morning took a picture and pointed out what needs to get bent or cut is it the right pinsThanks.


 
  
 The mirror image...... You have marked pins 1, 7, 8 and 9. But you want to cut or bend pins 9, 1, 2 and 3. 
  
 So in your picture, the top three pins from the left: 1, 2 and 3. And on the bottom, from the left, the first pin: 9.


----------



## gibosi

gibosi said:


> The mirror image...... You have marked pins 1, 7, 8 and 9. But you want to cut or bend pins 9, 1, 2 and 3.
> 
> So in your picture, the top three pins from the left: 1, 2 and 3. And on the bottom, from the left, the first pin: 9.


----------



## MIKELAP

gibosi said:


> The mirror image...... You have marked pins 1, 7, 8 and 9. But you want to cut or bend pins 9, 1, 2 and 3.
> 
> So in your picture, the top three pins from the left: 1, 2 and 3. And on the bottom, from the left, the first pin: 9.


 

 That would be right.OK just saw your picture thanks.


----------



## MIKELAP

Well my first try doesnt work im getting big hum.with pins 6and 7 cut does the socket still go in the same pin hole on the littledot?


----------



## gibosi

mikelap said:


> Well my first try doesnt work im getting big hum.with pins 6and 7 cut does the socket still go in the same pin hole on the littledot?


 
  
 Yes, you insert the adapter into the socket the same as always.
  
 I suspect it is your solder joints. You need to have a very solid and tight mechanical connection before you solder. Again, I encourage you to get some 30 gauge wrapping wire so you can tightly wrap it around the adapter pins 2 or 3 times. Good luck!


----------



## MIKELAP

gibosi said:


> Yes, you insert the adapter into the socket the same as always.
> 
> I suspect it is your solder joints. You need to have a very solid and tight mechanical connection before you solder. Again, I encourage you to get some 30 gauge wrapping wire so you can tightly wrap it around the adapter pins 2 or 3 times. Good luck!


 
 You were right gibosi about solder had a loose connection  sounds good now . Thanks .


----------



## Artsi

trolldragon said:


> Rollers here strap 1-7 with a socket wire on the MK II without noise, possibly try setting your switches to EF-95 & NS and then put a strap wire in 1-7 with the tubes to see if the hum returns.
> Also a 1-7 strap while in EF-92 mode might cause you some serious hum as well.
> 
> I'd double check your wiring with a meter.


 
 I'm going mad with this 7-1 strap hum problem. 
	

	
	
		
		

		
		
	


	




 7-1 strap works with wire in the socket, but i can't get it work without humming through switches. I resoldered everything what i added. Changed switches to new ones. Checked and measured everything ten times.
  
 Problem must be something with grounding, it sounds like it. Could switches get some interference from little dot housing. I live in old house with only phase and zero wirings.


----------



## gibosi

mikelap said:


> You were right gibosi about solder had a loose connection  sounds good now . Thanks .


 
  
 Good news! 
  
 So first impressions... How do your 6BQ7A sound?


----------



## TrollDragon

artsi said:


> I'm going mad with this 7-1 strap hum problem.
> 
> 
> 
> ...


 
 I have shielded wire on my switches with the shields not connected to anything just trimmed flush with the wire jacket, shrink tube on the ends where the switch wires leave the shield and jacket. It was suggested to me that I might ground one end of the shield to the chassis if I encountered a hum but leave the other end of the shield unconnected. It never happened so I never did.
  
 I can't really see a hum in only one position due to the wire or switches...
  
 The ground pin on the 110V mains socket in back connects directly to my board... So if you have only a two wire mains going to the amp it might be the problem.
  
 I am assuming that this is the way your switches are connected up?


----------



## Artsi

trolldragon said:


> I am assuming that this is the way your switches are connected up?


 
 Everything is connected just like that. I thought that on-off-on switch has some leakage and changed it to made in Japan switch and after that changed on-on switch to new one too. Measured that all modes connects correctly. Moved wires from jumper pins straight to socket solderings etc... 
	

	
	
		
		

		
		
	


	




 Next i'll need to change wall power outlet to better one with "safety" ground.


----------



## MIKELAP

gibosi said:


> Good news!
> 
> So first impressions... How do your 6BQ7A sound?


 

 First thing i noticed with these tubes is the black backround, its very detailed but warmer sounding than the 6av6 tubes this could be my next best tube but will compare more with the 6av6 will get back to you on this .And thanks to Troll Dragon's extended jumpers this dreaded operation is a breeze to do now.


----------



## MIKELAP

Can the ECC83 tubes go with this mod also they are double triodes


----------



## gibosi

mikelap said:


> First thing i noticed with these tubes is the black backround, its very detailed but warmer sounding than the 6av6 tubes this could be my next best tube but will compare more with the 6av6 will get back to you on this .And thanks to Troll Dragon's extended jumpers this dreaded operation is a breeze to do now.


 
  
 I am not surprised that you like these tubes. The 6BQ7A is often shipped from the Schitt factory with their Lyr. In researching the 6BQ7A and the 6DJ8, I spent some time reading the two Schiit tube rolling threads to help me decide which tubes to search for. While many people preferred the more expensive 6DJ8, others really liked the 6BQ7A. For sure, they are an inexpensive way to get a taste of the 6 volt dual triodes.
  
 http://www.head-fi.org/t/549508/schiit-lyr-the-tube-rolling-thread
  
 http://www.head-fi.org/t/673709/schiit-lyr-tube-rollers
  
 I have spent a little time listening to the Siemens and Mullard 6DJ8 I recently received, and very predictably, their sound follows the "British - Holland - German sound continuum" (copyright AFB lol), with the Mullards being the warmest and the Siemens being the most neutral. Further, the Mullards have a very smooth top end, while the Siemens have the most "air". And of course, the Amperex are in the middle. I need to spend more time listening to these three tubes, but so far, first impressions, I think I prefer the Amperex.


----------



## gibosi

mikelap said:


> Can the ECC83 tubes go with this mod also they are double triodes


 
  
 The ECC83 / 12AX7 are 12 volt tubes. And therefore, a different mod, similar to AFB's "Flying 12AT7 tube", is necessary. I am assuming that AFB is currently working on just such a mode that is a little more elegant and practical.


----------



## MIKELAP

mikelap said:


> First thing i noticed with these tubes is the black backround, its very detailed but warmer sounding than the 6av6 tubes this could be my next best tube but will compare more with the 6av6 will get back to you on this .And thanks to Troll Dragon's extended jumpers this dreaded operation is a breeze to do now.


 
 gibosi you mention the sound being holographic if it is what i think it means i do ear stuff in a Zubin Mehta cd and man id  swear something is in the room i ear sounds that seems to come from outside hard to explain but i like it alot .


----------



## gibosi

mikelap said:


> gibosi you mention the sound being holographic if it is what i think it means i do ear stuff in a Zubin Mehta cd and man id  swear something is in the room i ear sounds that seems to come from outside hard to explain but i like it alot .


 
  
 "Holographic" is just a fancy way of saying "3D." 
  
 The clarity and transparency of these tubes against a very black background can often convey the sense of being able to precisely locate the position of the various vocalists and instruments in space. Sometimes it seems that I hear things behind me... which can be pretty uncanny.... but for me, this added dimensionality really enhances the listening experience.


----------



## MIKELAP

gibosi said:


> "Holographic" is just a fancy way of saying "3D."
> 
> The clarity and transparency of these tubes against a very black background can often convey the sense of being able to precisely locate the position of the various vocalists and instruments in space. Sometimes it seems that I hear things behind me... which can be pretty uncanny.... but for me, this added dimensionality really enhances the listening experience.


 
 Think you guys brought us to the next level its great .Thanks


----------



## Sony Slave

gibosi said:


> Yes indeed, 30 awg wrapping wire works great.


 
 Do you strip the ends wire and wrap them around the pins?
  
 That's what am I am seeing correct>


----------



## gibosi

sony slave said:


> Do you strip the ends wire and wrap them around the pins?
> 
> That's what am I am seeing correct>


 
  
 Yes, this is exactly what I did. I left the insulation on because I was concerned that if the entire wire was stripped bare, it might come into contact with the metal in the center of the socket, and this might possibly create an electrical short circuit. This might be a bad thing.....


----------



## Audiofanboy

gibosi said:


> The ECC83 / 12AX7 are 12 volt tubes. And therefore, a different mod, similar to AFB's "Flying 12AT7 tube", is necessary. I am assuming that AFB is currently working on just such a mode that is a little more elegant and practical.


 
  
 Well, _actually_, I have had a DIY adapter for almost two weeks for those 12V tubes lol; I just haven't taken pictures of it to show my Schiity -some would even say Matsushiity- work. Truth is, since I thought that either the tube I had or something in my soldering was bad (intermittent dropouts in either channel every couple of minutes), I didn't dare show what I did until I knew it worked.
  
 Fortunately, the problem came from somewhere else in my sound chain (it happened regardless of tubes I used) which I have fixed since, so I'll post pics of the "adapter" soon! Don't get your hopes up too high though, it's basically a compact & clean version of the "flying 12AT7" mod with shorter wires (actually so short, I had trouble getting the wires to go to each socket...). But, I'm sure someone could just add some shrink wrap and make the same adapter look at least decent. Also, I used stranded wires because the wires are only soldered on one end and "stuck" in the socket adapters on the other end, but come to think of it, solid core would definitely be the way to not get a wobbly adapter.
  


gibosi said:


> I am not surprised that you like these tubes. The 6BQ7A is often shipped from the Schitt factory with their Lyr. In researching the 6BQ7A and the 6DJ8, I spent some time reading the two Schiit tube rolling threads to help me decide which tubes to search for. While many people preferred the more expensive 6DJ8, others really liked the 6BQ7A. For sure, they are an inexpensive way to get a taste of the 6 volt dual triodes.
> 
> http://www.head-fi.org/t/549508/schiit-lyr-the-tube-rolling-thread
> 
> ...


 
  
 I haven't even dared to go delve in the Schiit thread yet, as it seems like an other pool of varying opinions that would just drain my wallet quicker than buying DR tubes lol... But I gather that there aren't that many 6DJ8 tubes considered top tier, so the choice isn't that hard considering how much feedback there is on the internet. Philips, Siemens, Mullard, some German manufacturers and an occasional US tube, but you quickly go into second tier. I'm not buying a pair of Siemens CCa for $300 shipped from some crazy country quite yet!
  
 For 12Ax7 types -different pin layout than 6DJ8 tubes indeed- it is the same thing with perhaps more variety, if only because it's a large family; there are maybe 3-5 top recognized European tubes, and then all their iterations in time, sprinkle a RCA or so, and you don't have that much to pick out of essentially.


----------



## foreign

I tried the mullards 8100 they are yet to burn in but the treble is terrible has anyone found this changed after burn in ??


----------



## gibosi

audiofanboy said:


> I haven't even dared to go delve in the Schiit thread yet, as it seems like an other pool of varying opinions that would just drain my wallet quicker than buying DR tubes lol... But I gather that there aren't that many 6DJ8 tubes considered top tier, so the choice isn't that hard considering how much feedback there is on the internet. Philips, Siemens, Mullard, some German manufacturers and an occasional US tube, but you quickly go into second tier. I'm not buying a pair of Siemens CCa for $300 shipped from some crazy country quite yet!


 
  
 As you might guess, the super premium European versions are generally considered the very best of the 6DJ8, but fortunately, for those of us who have to live on a budget, the standard Amperex Orange Globes are often rated in the top tier as well. And with patience, these can often be found for as little as $25 a pair. In the end, for someone in my circumstances, with old ears, mid-fi cans and a $100 amp, purchasing a $300 pair of Siemens CCa is pretty hard to justify....
  
 But for now, listening to a pair of $25 Orange Globes through my cheap little LD1+ is pretty amazing. While probably not as good as a Schitt Lyr, I believe it might be pretty close.


----------



## Audiofanboy

I love used tubes, they don't require any burn-in and let you have fun right away without having to wait 4 days to enjoy your new toy... And of course, they're cheap! (somewhat)
  
 Just got my two no-silk-writing EI ECC83 (12AX7) tubes in the mail, so I killed two birds with one stone and took pictures of both the adapter and the new tube.
  

  
 No doubt about the source on this one: EI, Nish factory, Yugoslavia, ECC83, as per the codes on the bottom of the tube. I'd say 1980 for production date, could be 1970 or 1990, but that seems unlikely. And you can definitely see the recognizable "long smooth plates" that Telefunken is famous for on this tube type. The other tube I got barely has any legible factory codes and, while it has the exact same plates, is built a little differently. I could still kind of read the same factory code (little doubt on this one: Tele plates in Philips glass, not a gazillion solutions...), and a 7 for year code, so I'd say 1977 or 1987. The whole structure on this tube is 90° off compared to this picture, and the glass is different (not the "nub" and getter though, still Philips looking), so I can't know for sure which is one is "better" or older.
  

  
 Anyway, as you can see, I mounted it on my "new & improved" adapter to give it a spin. And, yeah, it's an awesome tube, seriously. I don't know what gibosi thinks about these double triodes, but it might be hard for me to go back to our previous pentodes and heptodes lol. Yes, these tubes are more expensive, but they're also money better spent!
  
 So, awesome tube, basically. Natural, musical, airy, detailed, realistic, holographic... I could go on with the adjectives but the rest of the world using this tube would describe it better. Now, I finally understand what people mean by the "Telefunken sound". And these EI Yugoslavia tubes are only supposed to be ~85% of the original Tele quality. _I would love to hear those last 15% now!_ Guess I should start hunting down genuine -used- Tele tubes huh?
  
 Quick reminder here: this is a ECC83/12AX7 tube with very high mu (voltage gain of 100), and low gm (between 1 and 2), whereas a -totally unrelated- ECC88/6DJ8 tube has medium mu (gain of 33) and very high gm (over 13, which is huge for driver tubes). So, these tubes would normally not be used in the same circuits or situations at all, even though they're well suited for voltage gain.
  
 For the moment, and though I very much like my EI -made on Philips gear- ECC88/6DJ8, I definitely find more listening pleasure (both critically and toe-tappingly) in these EI -with Tele plates- ECC83/12AX7. It may have to do with the inherent quality of each tube, but I actually think that the 12Ax7 types may be more suited to my use. I'm always trying to squeeze the last drop of sound quality and power out of my LD, and high gain driver tubes help me do that with my low impedance headphones.
  
 So, basically, if you're going to investigate either double triode tube family, choose the one that's better suited to your needs. A MK III user with HD650 phones may prefer the ultra-detailed and medium gain sound of the ECC88/6DJ8 for example. Just food for thoughts, and pure speculation...
  

  
 Now, the adapter. No, we won't talk about my soldering skills lol... I did what I could with very very limited resources (if you saw my soldering iron, you'd actually think I did an OK job here).
  
 I used a 9 pin ceramic socket (PCB soldering type) and soldered three 22awg gauge blue wires on the three active components of the first triode, three transparent 22awg wires on the second triode, and two + one smaller 26awg wires on the heater pins and center tap. Each wire I then painfully got to squeeze into the appropriate hole on each side -each socket saver. It was horrible and took me hours to complete, so I won't take it apart or play with it to show anyone how it's made lol, sorry...
  
 Tube actually sits right between the sockets, in the middle; I know it doesn't look straight but it can be, it just takes an effort to get it there with all those wires pulling in different directions and metal memory doing its thing. I think it doesn't even look that bad, frankly, and I could live with that, considering the sound quality! Again, making a prettier adapter from scratch (no socket savers) wouldn't be that hard...
  

  
 Bird's eye view to show how it looks and how tight -too tight- the wires are. You can see where the cabling for both triodes goes, but the wires for the heaters and center tap are hidden. For anyone that's interested, I'm sure I'll get around to posting the pin-to-pin details, if I haven't already, or if someone with more time and motivation than me does it before I do (gibosi, I know you're reading this lol)!


----------



## Artsi

I've been listening many hours with those new arrived tubes and made some initial observations. Westinghouse 6AG5 -45 tubes have beautiful glow, sad that their sound is not as good. Powertubes look little pale behind these.

  
 I got Brimar 6AT6 and they got box on top. These sound very good, but i still think not better than russian 6J5P. I'm going to use 6EW6 lifetime's little longer, sound is very promising. Others that got my attention were telefunken 6AM6S, fivre 6CB6, sylvania 6DK6 and GE 6DT6A.


----------



## gibosi

audiofanboy said:


> Anyway, as you can see, I mounted it on my "new & improved" adapter to give it a spin. And, yeah, it's an awesome tube, seriously. I don't know what gibosi thinks about these double triodes, but it might be hard for me to go back to our previous pentodes and heptodes lol. Yes, these tubes are more expensive, but they're also money better spent!


 
  
 I feel the same way. I have about 400 of these tubes - single triodes, pentodes and heptodes - and I seriously doubt that I will be listening to any of these in the future... I guess I ought to see if I can sell them....
  
 And so far, I have been able to stay below $15/tube, and I feel that this is a bargain for the level of quality I am getting from these 6DJ8. Perhaps my stock $30/pair Siemens are giving me 80% to 90% of a $300/pair Siemens CCa? And perhaps my old ears would not even be able to distinguish between them? lol
  


audiofanboy said:


> Bird's eye view to show how it looks and how tight -too tight- the wires are. You can see where the cabling for both triodes goes, but the wires for the heaters and center tap are hidden. For anyone that's interested, I'm sure I'll get around to posting the pin-to-pin details, if I haven't already, or if someone with more time and motivation than me does it before I do (gibosi, I know you're reading this lol)!


 
  
 Yes, I am reading this! lol And I will definitely try these 12 volt double triodes. But for now, I have yet to receive all the 6FJ8 I have ordered... and my wallet is begging me to take a pause!  Soon...


----------



## MIKELAP

Here are intructions on how to modify 6BQ7A or ECC/6DJ8 DOUBLE TRIODE tubes and the sockets they use.Its not pretty but it works. Pins 1-2-3-9 need to be bent or cut off on 6BQ7A tubes or if you are using ECC/6DJ8 and Littledot has to be on EF95 setting. you need to insert in a sequence tube pin 4-5-6-7-8 into pin holes 3-4-5-6-7 of the adapter and insert adapter in Littledot in regular position (remembering that there is 2 pins that were cut off on the adapter)                                                                                                                                                                                                                                                            Regarding socket mod ;using  wire solder pin 6 to pin 1 and pin 7 to pin 2 on adapter .Also you will need to cut  pins 6 and 7  those are the pins on the adapter that go in the Littledot. One last thing you can link pin 6 to 1 and 7 to 2 inside the adapter also for a cleaner look using 30 gauge wrapping wire .Wire used in picture is 22 gauge which is to big .                                                                                                                                                                                                                                                                                                                                                                                                                            Of course soldering the wires inside his not easy for a novice also you have to reinsert the pin assembly into socket holes which is loads of fun.ALSO ALWAYS REMEMBER THOSE WIRES HAVE ELECTRICITY PASSING THRU THEM SO BEWARE DO NOT TOUCH THE CONNECTIONS WHILE USING AMP.By the way a special thanks to Audiofanboy,gibosi, and Troll Dragon for there advice, instructions,and patience .Thanks guys.


----------



## KimChee

I just got my RCA 6DT6A's as recommended a few pages back.  All I can say is wow these sound amazing out of the box, I prefer them to my Mullard 8100, and I got two of them for $8 shipped.


----------



## Sony Slave

I now have a Little Dot 1+ with an LME4990 op amp and Voshkod tubes.
  
 My first impression of the product is underwhelming to be honest (it was paired with a Schiit Bi-Frost DAC). I tried the Voshkods, it had a black background with no distortion at all, I could hear MF DOOM whisper to his friends before he actually raps which kinda took me by surprise, I NEVER heard such micro details before. But overall, there was barely a difference in sound quality. I have heard Voshkods take a while to burn in (several days). So I installed the Tung-Sol 6AK5, if i'm not mistaken and then stuff started to change.
 The Tung-Sols have a little distortion, but I can hear stuff that I've never really heard before. Voices sound a bit more realistic. Slightly larger soundstage with better imaging. It didn't wow me.
 But of course, I have to let the tubes burn in for a couple of weeks before I even give my full opinion on this combo


----------



## kvtaco17

You sir need to explore further then the 6AK5 tubes... They are very average vs the other tubes we are currently all rolling. The 6DT6, 6AV6 and 6HM5 would be good starters.. The 6HM5 runs in EF95 with no straps and sound very good. Plus its fairly cheap.


----------



## Sony Slave

kvtaco17 said:


> You sir need to explore further then the 6AK5 tubes... They are very average vs the other tubes we are currently all rolling. The 6DT6, 6AV6 and 6HM5 would be good starters.. The 6HM5 runs in EF95 with no straps and sound very good. Plus its fairly cheap.


 
 I bought those WAAAAAAAAAAAAAAAAAAY back, about a month and a half ago.
  
 I just purchased these two tubes.
  
*Vintage Electronic 6DT6 6DT6A RCA and **1680 IBM 6BE6.*
  
 Are these any good?


----------



## Sony Slave

john57 said:


> Heat is one factor. Heat can dry out or breakdown the caps in time. When changing the caps one thing that can help is to use caps with a higher temperature ratings when possible. Also heat can effect the carbon resistors and the value can raise over long periods of time. Wireround resistors are more stable for long periods of time in the heat as compared to carbon resistors. Heat can also casue some sagging on parts in the tube*. There is also contamination in the tube if left on for long periods of time with no signal.*


 
 So guess it is not safe to burn in without music.


----------



## Sony Slave

mikelap said:


> i marked the jumper location in red for you if you magnify picture you will see better
> 
> 
> you see the red rectangle right of the volume right below its marked EF92 AND THERES 2 PINS thats your EF92 jumper the other one IS NEXT TO THE RED SQUARE and the bottom to the left there to its marked EF92 THOSE ARE THE LEFT AND RIGHT CHANNEL JUMPERS. for the other jumpers i see 2 other jumpers but its marked J3 so those must be your EF95 JUMPERS i dont see any other unless you see an EF95 inscription somewhere i dont . so those jumpers are right in the middle of the board.to the left of the opamp so i would SAY that according to the picture the amp is set on EF95 setting because jumpers are on the 2 pins get it so in this case to have the EF92 SETTING you remove the jumpers from J3 or EF95 and put them on EF92 JUMPERS . I hope its clear .


 
 My circuit board looks quite a bit different.
 There are no switches present.
 I need help moving the K1/K2 switches to side marked as 6j1 text on the circuit (EF95). Pics will help a lot. I have a Little Dot 1+.
  
 There are two blue resistors inside of the little dot 1+, are the jumpers supposed to be in the same  orientation as the resistors?
 If we were to compare the older Little Dot to the newer one in the exact position as the one above. The resistors would be horizontal, just like the ones by the op amp.
 So far my K1/K2 switches are horizontal as well, is this correct?


----------



## gibosi

sony slave said:


> I bought those WAAAAAAAAAAAAAAAAAAY back, about a month and a half ago.
> 
> I just purchased these two tubes.
> 
> ...


 
  
 Which ones did you buy about a month and a half ago?  6AK5? 6HM5? 6AV6?
  
 And of course, "good" is very subjective...  Personally, I thought the RCA 6DT6 and the IBM (RCA) 1680 were quite similar, rather warm and very enjoyable tubes.


----------



## Sony Slave

gibosi said:


> Which ones did you buy about a month and a half ago?  6AK5? 6HM5? 6AV6?
> 
> And of course, "good" is very subjective...  Personally, I thought the RCA 6DT6 and the IBM (RCA) 1680 were quite similar, rather warm and very enjoyable tubes.


 
 6AK5.


----------



## Sony Slave

jaywillin said:


> ok, mine didn't have switches either, so the diagram is more accurate then really
> look at your board, and identify the jumpers j1, j2, 3,4,5,6,
> the jumpers are the black pieces of plastic with the 2, or 3 wire post coming out , use some needle nose pliers
> tweezers and they'll slide up and off, or just slide down to reinsert , make sure when you are putting them back on
> ...


 
 The j1 and j2 jumpers are vertical, the j3/j4 jumpers are horizontal. Do I place the K1/k2 jumpers next to the 6j1 text vertically like the j1/j2 or horizontally, like the j3/j4? (I have a newer Little Dot 1+)


----------



## gibosi

sony slave said:


> My circuit board looks quite a bit different.
> There are no switches present.
> I need help moving the K1/K2 switches to side marked as 6j1 text on the circuit (EF95). Pics will help a lot. I have a Little Dot 1+.
> 
> ...


 
  
 Jumpers K1 and K2 allow you to switch between 408A tubes, which have 20V heaters, and EF95 tubes, which have 6V heaters. As you have been using EF95 tubes without smoke, or worse, I would assume that these jumpers are already set correctly, that is, for 6J1/EF95. Unless you are intending to use 408A tubes, I would advise that you leave these jumpers alone for now.


----------



## Sony Slave

gibosi said:


> Jumpers K1 and K2 allow you to switch between 408A tubes, which have 20V heaters, and EF95 tubes, which have 6V heaters. As you have been using EF95 tubes without smoke, or worse, I would assume that these jumpers are already set correctly, that is, for 6J1/EF95. Unless you are intending to use 408A tubes, I would advise that you leave these jumpers alone for now.


 
 They goodness they never smoked. My brother figured it out.
  
 Thank you for the help!


----------



## Sony Slave

Alright guys, i'm going to hook up the little dot 1+ to my computer and loop a track on repeat until 7 to 8 o'clock. Then i'll see how these GE-JAN 5654W tubes burn in.....


----------



## Audiofanboy

gibosi said:


> I feel the same way. I have about 400 of these tubes - single triodes, pentodes and heptodes - and I seriously doubt that I will be listening to any of these in the future... I guess I ought to see if I can sell them....
> 
> And so far, I have been able to stay below $15/tube, and I feel that this is a bargain for the level of quality I am getting from these 6DJ8. Perhaps my stock $30/pair Siemens are giving me 80% to 90% of a $300/pair Siemens CCa? And perhaps my old ears would not even be able to distinguish between them? lol
> 
> ...


 
  
 All I can say right now is that I am truly struck by how good my Tele lookalike EI ECC83 are. I spent a whole evening listening to music and movies with these (technically "this", as I'm only using one tube at the moment) and apart from the relative sound quality, the feeling of immersion -being "there" in the sound- is two or three notches above anything else I've tried.
  
 It's not subtle or obvious changes, it's simply revolutionary! And I paid less for that tube that what most people paid for a pair of M8100, and the result is so much better it isn't even funny lol... (the M8100 still being my fav' 6AK5 tube this being said)
  
 I urge you lads to jump on the double triode bandwagon; we just need to find easier ways to adapt tubes and then we'll be set (then again, adapting a ECC88/6DJ8 tube with my current method is pretty easy actually; it's adapting 12V tubes that's hard for now)!


----------



## TrollDragon

I'd there was only more room in the case...

If I could obtain one of the larger tube rings from a MKIII and a nice B9A socket. I would machine a hole down through the case top, surface mount the socket in the middle of the 4 tubes and surround it with the finishing ring from the MKIII. 

Take out the two front tubes pop in the 12A?7 and your done. Those MKIV tube protectors are available on eBay in various finishes to give a bit of uniformity to the new tube as well, but you might not even need the other finishing ring with the protector in place.

There are many choices but unfortunately for me other things take precedence right now... I think this is the avenue I will follow when I can assemble the parts, so it looks good as well as functions easily.


----------



## TrollDragon

I was selected for the Burson / Audeze demo program. It should be nice to hear the LCD's through the MK IV, as well as the DT880's with the Conductor.

I can't wait...


----------



## gibosi

A pair of Tesla 7DJ8 / PCC88 arrived today, NOS/NIB, made in September, 1970. These cost $27.00, including shipping. Similar to AFB's Ei ECC83, premium pairs of 408A, 6AK5, EF91 and EF92 will cost this much, and more. But these double triodes are so much better....


----------



## Sony Slave

audiofanboy said:


> All I can say right now is that I am truly struck by how good my Tele lookalike EI ECC83 are. I spent a whole evening listening to music and movies with these (technically "this", as I'm only using one tube at the moment) and apart from the relative sound quality, the feeling of immersion -being "there" in the sound- is two or three notches above anything else I've tried.
> 
> It's not subtle or obvious changes, it's simply revolutionary! And I paid less for that tube that what most people paid for a pair of M8100, and the result is so much better it isn't even funny lol... (the M8100 still being my fav' 6AK5 tube this being said)
> 
> I urge you lads to jump on the double triode bandwagon; we just need to find easier ways to adapt tubes and then we'll be set (then again, adapting a ECC88/6DJ8 tube with my current method is pretty easy actually; it's adapting 12V tubes that's hard for now)!


 
 Do you know off certain brands to look for, they are about $25 at the least from these vendors.
  
http://www.ebay.com/bhp/ei-ecc83
  
 But prices are as low as $13 to $10 from these vendors.
http://www.ebay.com/bhp/ecc83-tube
  
 Who should I buy from?
  
 Also is there a post that you or someone else has made in regards to modding these tubes in order for them to work with the Little Dot?
 I would like to see it.


----------



## i luvmusic 2

sony slave said:


> Alright guys, i'm going to hook up the little dot 1+ to my computer and loop a track on repeat until 7 to 8 o'clock. Then i'll see how these GE-JAN 5654W tubes burn in.....


 
 I think that is the same one i just got JAN-GE 5654W RN No 2754289 Serial No 2MT84-02555 Dated 3/85.


----------



## gibosi

A pair of Reflector 6N23P, manufactured in 1969, just arrived. The 6N23P is the Russian equivalent to the 6DJ8 / ECC88. These were $21.00 shipped, so again, not that expensive....


----------



## hypnos1

audiofanboy said:


> All I can say right now is that I am truly struck by how good my Tele lookalike EI ECC83 are. I spent a whole evening listening to music and movies with these (technically "this", as I'm only using one tube at the moment) and apart from the relative sound quality, the feeling of immersion -being "there" in the sound- is two or three notches above anything else I've tried.
> 
> It's not subtle or obvious changes, it's simply revolutionary! And I paid less for that tube that what most people paid for a pair of M8100, and the result is so much better it isn't even funny lol... (the M8100 still being my fav' 6AK5 tube this being said)
> 
> I urge you lads to jump on the double triode bandwagon; we just need to find easier ways to adapt tubes and then we'll be set (then again, adapting a ECC88/6DJ8 tube with my current method is pretty easy actually; it's adapting 12V tubes that's hard for now)!


 
  
 Hi AFB.
  
 Have finally given in and am giving the double triode route a try...but would love your opinion on what I am contemplating...
  
 First off, with the price of those adapters looking a bit pricey, I thought of having a go at making my own using some very nice-looking HQ ceramic sockets (similar to yours) with gold-plated 'pins', and cannibalised tube bases - wish me luck!!
  
 Secondly, it looks as though the Russian 6N2Ps could be substituted for the ECC88s, even though they are listed as '83's when actually they CAN'T be a straight substitute for the latter...which would be rather nice (if poss.) as they are described as very high quality, and some even say BETTER than your average ECC83. Especially the ER version...
  
 So I would be most grateful if you could verify that I am not going to be sending my beloved LD to an early grave!!
  
 This may also be of great use to others if this option is OK?...
  
 Cheers.


----------



## Sony Slave

gibosi said:


> A pair of Reflector 6N23P, manufactured in 1969, just arrived. The 6N23P is the Russian equivalent to the 6DJ8 / ECC88. These were $21.00 shipped, so again, not that expensive....


 
 How do I make them compatible with the Little dot?


----------



## Nic Rhodes

Bear with me, thinking aloud here....
  
 I am expecting some Vector sockets in the post in the mean time I have been looking at other solutions to make adapters. It strikes me that B7G sockets at 10 a penny but B7G plugs (correctly spaced pins) are the hard bit. We could canabalise a tube but I have loads of the UK military black pin protectors that often come with valves. Two or three of these could make excellent support to some pins connected to day a (PCB) valve socket with a suitable tubular cover. In reality you only need two to have straight and correctly spaced pins but three might add stabiity and I have loads! The thing I need to find is a suitable rod, cut or cutable that could make the connection and act as the new pins for these potential socket adapters. Has anyone looked at this previously?
  
 An expensive way to buy them but listing shows the items I mean (good seller by the way):
  
 http://www.ebay.co.uk/itm/2-x-Pin-straighteners-protectors-for-B9A-B7G-valves-/171004691175?pt=UK_Sound_Vision_Valves_Vacuum_Tubes&hash=item27d0ac82e7


----------



## gibosi

sony slave said:


> How do I make them compatible with the Little dot?


 
  
 Audiofanboy, MIKELAP and myself have submitted quite a few posts showing how this is done.
  
 Search for 6DJ8 ECC88 and 6BQ7A.
  
 Here are a few posts:
  
 http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/3045#post_9830528
  
 http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/3135#post_9842518
  
 http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/3150#post_9844996
  
 http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/3150#post_9845096
  
 http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/3420#post_9880571


----------



## Sony Slave

gibosi said:


> Audiofanboy, MIKELAP and myself have submitted quite a few posts showing how this is done.
> 
> Search for 6DJ8 ECC88 and 6BQ7A.
> 
> ...


 
 If someone made a table of contents for everything and anything to do with little dot tube rolling, that would be amazing!
  
 Thank you.


----------



## TrollDragon

In the whole thread there is an amazing assemblage of excellent knowledge, if you start at the begining, it is very rewarding. There is also a thread for the LD 1+ as well, which is also chock full of great information about your amplifier.


----------



## gibosi

sony slave said:


> If someone made a table of contents for everything and anything to do with little dot tube rolling, that would be amazing!
> 
> Thank you.


 
  
 Yes, it would! Would you like to volunteer to do this for us? lol 
  
 In the meantime, I use the "Search This Thread" tool that is available at the top and bottom of every page. For example, I can search for every mention of "6DJ8", and if I click on "Advanced search options", I can narrow my search down to a specific user and a specific time frame. I find this to be a very powerful tool to search for information in threads such as this with several hundred posts.


----------



## hypnos1

kimchee said:


> I just got my RCA 6DT6A's as recommended a few pages back.  All I can say is wow these sound amazing out of the box, I prefer them to my Mullard 8100, and I got two of them for $8 shipped.


 
  
 Hi Kim.
  
 Glad you like these tubes...and yes, you MUST also try the 6HM5s on your MK111, EF95 setting - an even bigger WOW! (Please see below...).
  
 Hi all.
  
 Before I fly off into dble triode land, final reflections on the 6HM5s ( Ei Yugoslavia). Have just had a minor shock after burning in my second pair...they are from the same batch of 100 tubes (ebayer tachonz, Serbia) with identical codes, and where the first were amazing, but with a slightly lighter bass kick than some others we have all(?) tried up until now - not counting double triodes, that is - the bass on this second pair SURPASSES all those I have known. I could not believe my ears... how could this be? This just goes to prove once and for all that so much of what we receive from our tubes is down to LUCK OF THE DRAW!..Another good reason to buy more than just one pair at a time?
  
 Also had final confirmation that so often we have no surefire certainty re the true origins of a tube, via a statement/admission on  youtube links to 2 videos on tube manufacture at Ei Yugoslavia (posted on the Serbian tachonz site), viz : Ei even put on other peoples' codes so 'they' can be sure of the quality! So once 'Yugoslavia' - or similar - has worn off/been removed (who said that?!) the code would have you thinking otherwise...food for thought?
  
 Happy (lottery?) rolling everyone!


----------



## siles1991

hypnos1 said:


> Hi Kim.
> 
> Glad you like these tubes...and yes, you MUST also try the 6HM5s on your MK111, EF95 setting - an even bigger WOW! (Please see below...).
> 
> ...


 
 Was wondering what 6HM5 tubes would be cool to try. Been staring intently at Sylvania's since i've had really good results from sylvania all this while. BUT the RCA 6DT6A's brought the house down xD so was thinking if I should go for a RCA instead hmmm....if the same seller had sylvania and RCA together would be really great haha as since shipping is terribly expensive for me. Though the Sylvie's look short so i'm skeptical about it haha, unless its just the picture that made it look puny.
  
 I'm still looking for someone who would allow me to send them some of the tubes i buy and help me repack them together so it'd be cheaper to ship over to me.


----------



## gibosi

siles1991 said:


> Was wondering what 6HM5 tubes would be cool to try. Been staring intently at Sylvania's since i've had really good results from sylvania all this while. BUT the RCA 6DT6A's brought the house down xD so was thinking if I should go for a RCA instead hmmm....if the same seller had sylvania and RCA together would be really great haha as since shipping is terribly expensive for me. Though the Sylvie's look short so i'm skeptical about it haha, unless its just the picture that made it look puny.


 
  
 I have a pair of RCA 6HM5 and in my opinion, they are not worth buying. Mine are short and squat, like a 6AK5, and they were made by Siemens. Since I do not believe that RCA made any of these tubes, it is most likely that any RCAs you find were made by another manufacturer. I have not heard the Sylvanias, but I do have a couple pair of GEs, made in Great Britain, and I recommend them to you.


----------



## Sony Slave

gibosi said:


> I have two kinds of adapters. The pictured adapter is a little cheaper and simpler, but otherwise, they are essentially the same. There is a long machine screw that extends from top of the adapter and secured with a small nut in the bottom, between the pins. So you simply take it apart....
> 
> 
> 
> ...


 
 Where can I buy the adpters, I searched for them on ebay.
http://www.ebay.com/bhp/vacuum-tube-adapter
  
 Which ones do I buy, and are the tall ones better than the short ones in terms of sound?
  
 I would like the ones above.


----------



## wje

trolldragon said:


> In the whole thread there is an amazing assemblage of excellent knowledge, if you start at the begining, it is very rewarding. There is also a thread for the LD 1+ as well, which is also chock full of great information about your amplifier.


 
  
 You are very correct.  There are a few great, longer threads on the forum here that have sustained the test of time over a period of years.  One really has to essentially read many of the posts because to try and get brought up to speed with the Cliff's Notes version is virtually impossible.  People can give a few tips and be succinct, but there will still be a lot of "golden nuggets" of information that will be missed.
  
 With that being said, my Little Dot I+ has been fine for several weeks with the stock tubes and I had planned to spend more time in this thread to catch up on the variants.  But, last evening, I realized I was getting periodic static in one of the channels every minute or two.  I believe one tube might be on its way out, so now's as good of time as any to hop in an get my feet wet with the tubes.  Also, the option of seeking Op-Amp variations is interesting, too.  This is the 2nd time I've owned the Little Dot I+, but never tried other tubes.  Soon ... Soon.


----------



## Edgard Varese

wje said:


> You are very correct.  There are a few great, longer threads on the forum here that have sustained the test of time over a period of years.  One really has to essentially read many of the posts because to try and get brought up to speed with the Cliff's Notes version is virtually impossible.  People can give a few tips and be succinct, but there will still be a lot of "golden nuggets" of information that will be missed.
> 
> With that being said, my Little Dot I+ has been fine for several weeks with the stock tubes and I had planned to spend more time in this thread to catch up on the variants.  But, last evening, I realized I was getting periodic static in one of the channels every minute or two.  I believe one tube might be on its way out, so now's as good of time as any to hop in an get my feet wet with the tubes.  Also, the option of seeking Op-Amp variations is interesting, too.  This is the 2nd time I've owned the Little Dot I+, but never tried other tubes.  Soon ... Soon.


 
  
 One of my 6A2P heptodes was a little scratchy last night... (I have a lot of spares).  I swapped them out and put in the IBM 6BE6 pair I got, which I immediately discovered to be microphonic.  I will give them a proper listen though (I usually leave a new pair in for a week or so and then swap them).


----------



## TrollDragon

wje said:


> You are very correct.  There are a few great, longer threads on the forum here that have sustained the test of time over a period of years.  One really has to essentially read many of the posts because to try and get brought up to speed with the Cliff's Notes version is virtually impossible.  People can give a few tips and be succinct, but there will still be a lot of "golden nuggets" of information that will be missed.
> 
> With that being said, my Little Dot I+ has been fine for several weeks with the stock tubes and I had planned to spend more time in this thread to catch up on the variants.  But, last evening, I realized I was getting periodic static in one of the channels every minute or two.  I believe one tube might be on its way out, so now's as good of time as any to hop in an get my feet wet with the tubes.  Also, the option of seeking Op-Amp variations is interesting, too.  This is the 2nd time I've owned the Little Dot I+, but never tried other tubes.  Soon ... Soon.


 

 Welcome to the thread wje!
  
 Acapella11 here has researched and compiled an excellent table on page 77 that lists all the current tubes that have been tested and the modes they operate in. Many members have a favorite tube or set of tubes that will plug right in. Recently experimenting with dual triodes that require modified B7G socket extenders is the order of the day with much room for modding.
  
 You'll find lots of choices and options here!


----------



## gibosi

sony slave said:


> Where can I buy the adpters, I searched for them on ebay.
> http://www.ebay.com/bhp/vacuum-tube-adapter
> 
> Which ones do I buy, and are the tall ones better than the short ones in terms of sound?
> ...


 
  
 Sonically, it makes no difference which ones you use.
  
 I purchased the short ones from Leeds Radio:
  
 Test socket 7 pin miniature for $8.00 each.
  
 http://leedsradio.com/parts-sockets.html#savers
  
 And the tall ones from RadioDaze:
  
 7 pin Vector socket adapter with test points, SKA-7-B, for $5.00 each
  
 http://www.radiodaze.com/product/15450.aspx


----------



## Sony Slave

gibosi said:


> Sonically, it makes no difference which ones you use.
> 
> I purchased the short ones from Leeds Radio:
> 
> ...


 
 I found the product from leedsradio, now how do I buy it, do I just contact them via telephone?


----------



## gibosi

sony slave said:


> I found the product from leedsradio, now how do I buy it, do I just contact them via telephone?


 
  
 I used email -- sales@leedsradio.com and they sent me a paypal invoice.


----------



## hypnos1

siles1991 said:


> Was wondering what 6HM5 tubes would be cool to try. Been staring intently at Sylvania's since i've had really good results from sylvania all this while. BUT the RCA 6DT6A's brought the house down xD so was thinking if I should go for a RCA instead hmmm....if the same seller had sylvania and RCA together would be really great haha as since shipping is terribly expensive for me. Though the Sylvie's look short so i'm skeptical about it haha, unless its just the picture that made it look puny.
> 
> I'm still looking for someone who would allow me to send them some of the tubes i buy and help me repack them together so it'd be cheaper to ship over to me.


 
  
 Hi siles.
  
 Can wholeheartedly recommend the ones I have been talking about ie Ei Yugoslavia, as per gibosi's Ei 6HM5 link on page 225, post # 3366. They have accepted my offers of $5 per tube and state FREE worldwide shipping - what more can you ask?..worth every penny/cent!! (There are also links at the bottom of their page to interesting videos from the Ei factory).
  
 Happy rolling...


----------



## Sony Slave

gibosi said:


> I used email -- sales@leedsradio.com and they sent me a paypal invoice.


 
 Thanks.
 I just found a vendor who is selling 6AV6 tubes in bulk for cheap.

http://www.ebay.com/itm/6AV6-Vacuum-Tube-NOS-Worldwide-Shipping-Available-/231060567083
  
 Do the GE amd RCA tubes sound any different? He said that you can message him and pick your desired tubes.


----------



## Sony Slave

mikelap said:


> Looks like theres 2 mods  one is this by AFB :
> Yes, basically you are trying to use only the first triode in the tube, so all the leftover pins need to be neutralized or at least out of the way. So, pins 1, 2, 3 & 9 of the 6BQ7A need to be bent or cut, while pins 4, 5, 6, 7 & 8 can be inserted in a sequence into the socket hole 3, 4, 5, 6 & 7 of your adapter. Next, you just have to link/solder pin 6 to pin 1, and pin 7 to pin 2 on the adapter (with pins 6 & 7 disconnected at the base), and voila! You get a single 7-pin triode!
> 
> Gibosi actually summed it up better than I can in his post:
> ...


 
 In your or anyone else's experience, what is the best 6AV6 tubes out there in terms of soundstage, treble and detail?


----------



## gibosi

sony slave said:


> Thanks.
> I just found a vendor who is selling 6AV6 tubes in bulk for cheap.
> 
> http://www.ebay.com/itm/6AV6-Vacuum-Tube-NOS-Worldwide-Shipping-Available-/231060567083
> ...


 
  
 My GE have the box-like structure on the top mica (shall we call this structure a "box-getter"?), while my RCAs do not, and they sound quite different. These RCAs are brighter and more forward than the GEs. However, Mordy has reported that he has RCAs with box-getters, and that they sound very good. However, I do not know if they sound the same as the my RCAs.....


----------



## gibosi

sony slave said:


> In your or anyone else's experience, what is the best 6AV6 tubes out there in terms of soundstage, treble and detail?


 
  
 MIKELAP's posting that you quoted from is in regard to 6-volt double triodes, namely 6DJ8 and 6BQ7A / 6BZ7. These are very different than the 6AV6.....
  
 Of all the 6AV6 I have heard, the GE, Toshiba, FIVRE and Tung-Sol 6AV6 (and sisters, 6AT6 / 6AQ6) with box getters have the best sound stage, treble and detail. And further, after reading Mordy's observations, I think I can safely say that any 6AV6 with box-getters should be excellent.


----------



## Sony Slave

Ok, I'm about to research the GE's a little more.


----------



## TrollDragon

Those NEC 6AV6's without the box are not an enjoyable listen IMHO...


----------



## Artsi

Brimar 6AT6 with box are also better than westinghouse and NEC 6AV6's without box. There seems to be some other structural differences too between with and without the box and that causes different sound.
  
 Here is short list of tubes that are better than my 6AV6's without box, imo.
  
 Sylvania 6DK6 Made in USA. These seems to have little bass boost.

  
  
 Fivre 6CB6 Made in Italy. They have made something right in Italy.

  
  
 Lifetime 6EW6 Made in Japan. This pair looks little different inside, but sound is similar.

  
  
 Raytheon 6AN5 Made in USA -65. These heart of oaks really beats the crap out of NEC 6AV6's. Easy to use with EF95 mode.

  
  
 Telefunken 6AM6S. Big box on top must do something to music.


----------



## mordy

Hi Sony Slave,
  
 I have listened carefully to three types of 6AV6 tubes with the box getter; RCA, Tung Sol and Sylvania.
  
 It seems to me that the RCAs are excellent, but the Sylvania with a clear top, a little dish on top of the plate, side getter, and box top are even better. Here is a picture:
  

  
 Now, burning in the amp itself, burning in headphones, speakers, _and burning in tubes_, require a signal. In the olden days you could buy CDs with a burn in signal that comprised all frequencies in a sweep. I would just leave the track on repeat, leave the volume on low, close the door and leave it overnight for a few nights.
 Another suggestion is to use FM "white noise" which is what you hear between stations.
  
 Here is a link to white noise, pink noise and something new to me: brown noise.
 http://www.youtube.com/watch?v=L3CiZxstvEA
  
 My guess is that most mechanical and electronic things improve after a burn in/use period. Just think of a new car, or a new pair of shoes or a new chair - they all function better after being used!
  
 The 6AV6 tubes come into full bloom first after some 50 hours of burn in, and the change is dramatic.


----------



## wje

_*Today's random tube thought*_:  It's too bad that tubes are not available locally for those who seek instant gratification.  The wait is killing me ... and, I still haven't ordered any new tubes yet.


----------



## Sony Slave

mordy said:


> Hi Sony Slave,
> 
> I have listened carefully to three types of 6AV6 tubes with the box getter; RCA, Tung Sol and Sylvania.
> 
> ...


 
 I see. I am looking for the ones that you have posted above, but I can not find them.


----------



## Sony Slave

artsi said:


> Brimar 6AT6 with box are also better than westinghouse and NEC 6AV6's without box. There seems to be some other structural differences too between with and without the box and that causes different sound.
> 
> Here is short list of tubes that are better than my 6AV6's without box, imo.
> 
> ...


 
 Thank you. I take it that the *RAYTHEON * are the best of the bunch.


----------



## TrollDragon

wje said:


> _*Today's random tube thought*_:  It's too bad that tubes are not available locally for those who seek instant gratification.  The wait is killing me ... and, I still haven't ordered any new tubes yet.


No this is a good thing as the local tube merchant would be my crack dealer...


----------



## Oskari

artsi said:


> Telefunken 6AM6S. Big box on top must do something to music.


 
  
 Interestingly, the SFR PM07 markings are still visible. In this case, Telefunken apparently relabeled a French tube.


----------



## Sony Slave

I got lucky. After searching through an entire list of ads on the 6AV6, 6ATQ, and finally the 6AQ6 family,  I found what mordy was telling me to look for!
  
 I thought I would never find them and I was just about to settle for the Raytheon 6AN5.
  

  
 The vendor was only selling two of them as well, are these any good?


----------



## Artsi

sony slave said:


> Thank you. I take it that the *RAYTHEON * are the best of the bunch.


 
 No, no. Best of those 5 tube models are Sylvania 6DK6, Fivre 6CB6 and Lifetime 6EW6. Old raytheons does not have a change against those, but they still win no-box 6AV6's.
  


oskari said:


> Interestingly, the SFR PM07 markings are still visible. In this case, Telefunken apparently relabeled a French tube.


 
 It is not surprise if i like french tubes, i like french cars too (or price of the used cars).


----------



## Sony Slave

How do the Sylvania 6DK6  compare to the Sylvania  6AQ6?


----------



## wje

artsi said:


> No, no. Best of those 5 tube models are Sylvania 6DK6, Fivre 6CB6 and Lifetime 6EW6. _*Old raytheons does not have a chance against those, but they still win no-box 6AV6's.*_
> 
> It is not surprise if i like french tubes, i like french cars too (or price of the used cars).


 
  
 I'm thinking that might be why the Ratheon tubes are only commanding about $1.50 each on Ebay at the moment.


----------



## mordy

Hi Sony Slave,
  
 I can't find them either right now. However, patience pays off. Keep on looking on Ebay, and they will show up.
  
 The other thing is that many pictures are not clear, and some tubes only have pictures of the box. The answer is communication. Ask the seller which type it is, and send a picture to show what you are looking for.
  
 Good luck!


----------



## mordy

Hi again Sony Slave,
  
 "How do the Sylvania 6DK6  compare to the Sylvania  6AQ6?"
  
 The Syl 6DK6 is a completely different family than the 6AQ6. The 6AQ6 should be much superior sounding. The 6AQ6 is an early version of the 6AV6 tube and should be very similar to it. I have the 6DK6 but I have not heard the 6AQ6.
  
 IMHO the 6AQ6 are well worth trying.
  
 Good luck!


----------



## Sony Slave

mordy said:


> Hi again Sony Slave,
> 
> "How do the Sylvania 6DK6  compare to the Sylvania  6AQ6?"
> 
> ...


 
 Good thing I bought the Sly 6AQ6!
  
 I have question, is it normal to have each and every tubes to sound the same (Voskod, GE JAN 5654W, and Stock Chinese). The only ones to sound different were the Tung Sol's 6AK5.
  
 I really wonder if the tubes that I bought, (Slyvania 6AQ6, 1680 IBM 6BE6, and RCA  6DT6/6DT6A) actually make a drastic difference in sound quality. Even when paired with the Schiit Bifrost Uber, it is still underwhelming.
  
Maybe I need to invest in those 12ax7 tube (*TESLA 7DJ8/ 6N23P ). *
 By the way, is their a difference in sound quality between the Russian 6N23P and the Tesla 7DJ8 tubes?


----------



## gibosi

sony slave said:


> Good thing I bought the Sly 6AQ6!
> 
> I have question, is it normal to have each and every tubes to sound the same (Voskod, GE JAN 5654W, and Stock Chinese). The only ones to sound different were the Tung Sol's 6AK5.
> 
> ...


 
  
 I personally did not think that all these 6AK5s sounded the same. But then again, everyone has different ears and different gear....
  
 And while the IBM 1680 (which was manufactured by RCA) and the RCA 6DT6 share a similar "house sound", the various 6A?6 tubes sound very different compared to these two RCA tubes.... to my ears....
  
 The 7DJ8 and 6N23P are 6-volt triodes, while the 12A?7 are 12-volt. To my knowledge, at this point in time, the only person who has heard both of these in a Little Dot is Audiofanboy. Given that, we just don't have enough experience in this forum to be able to say anything meaningful about how these tubes might compare in our LDs.
  
 I do have a pair of Tesla 7DJ8, but haven't had a chance to see if they will even light up. And the same goes for my Reflector 6N23P. Once I have had a chance to spend some time with these tubes, I will come back here to share my impressions. (And of course, if someone else gets around to listening to these tubes before I do, I hope they will let us know what they think! 
  
 For now, I am still trying to get a handle on the Amperex, Mullard and Siemens 6DJ8. My feeling so far is that the Siemens are a little too cool for my taste. I think I prefer a slightly warmer sound signature. (However, I am sure that there are those among us who would prefer the sound of the Siemens.) Anyway, I want to spend more time with the Amperex and Mullards before I add Tesla and Reflector to the mix.


----------



## gibosi

While not exactly a tube-related question, I would like to take advantage of the vast experience of the good people in this forum and ask for recommendations for a DAC costing around $200. (Or more, if I can find one used in the Head-fi for-sale / trade forum for around $200.) The optical-in on my no-name budget DAC is getting flaky and the USB-in is only 16 bit, so I would like to get something better.
  
 Thanks!


----------



## wje

gibosi said:


> While not exactly a tube-related question, I would like to take advantage of the vast experience of the good people in this forum and ask for recommendations for a DAC costing around $200. (Or more, if I can find one used in the Head-fi for-sale / trade forum for around $200.) The optical-in on my no-name budget DAC is getting flaky and the USB-in is only 16 bit, so I would like to get something better.
> 
> Thanks!


 
  
 Why not just opt for the ODAC?  I was surprised at how well it really performed.  I had the comb unit with the O2 amp, too.  I sold it because there wasn't a way to use just the ODAC and skip the O2 amp in that scenario.  I've used the Schiit Modi too, but with the Magni amp.  The circumstances at the time were not ultimate to do enough testing.  I'd like to hear the Modi again, though - especially with the Little Dot I+ amp.
  
 Is there a reason for going for a 24Bit DAC?  Do you listen to higher resolution music above regular Redbook CD, which is 16-bit audio?


----------



## wje

Edgard Varese said:
			
		

> One of my 6A2P heptodes was a little scratchy last night... (I have a lot of spares).  I swapped them out and put in the IBM 6BE6 pair I got, which I immediately discovered to be microphonic.  I will give them a proper listen though (I usually leave a new pair in for a week or so and then swap them).


 
  
 After giving my issue some thought.  I took a small piece of emory cloth and cleaned up the conductors for the tubes.  I then ensured all the dust from cleaning up the tips had been removed as I didn't want to push that stuff down into the tube sockets.  Ironically, after 30 minutes of listening, I no longer hear the intermittent static on one of the channels.  Normally, it would come in every few minutes and last 3 or 4 seconds long.
  
 I tried to search for my can of Deoxit, which I would have probably tried instead of sanding the conductors - but, what I did was fine.  Some day, though,  I'll unplug the amp, and spray to tube sockets with Deoxiti and let it dry for several hours.  I bought the LD I+ 2nd hand.  Also, noticed that the rear RCA connectors are tarnished a bit and not really the polished gold color of most RCA connectors.  I guess the amp might have been used in an area that wasn't so good for the various connections.


----------



## Edgard Varese

wje said:


> After giving my issue some thought.  I took a small piece of emory cloth and cleaned up the conductors for the tubes.  I then ensured all the dust from cleaning up the tips had been removed as I didn't want to push that stuff down into the tube sockets.  Ironically, after 30 minutes of listening, I no longer hear the intermittent static on one of the channels.  Normally, it would come in every few minutes and last 3 or 4 seconds long.
> 
> I tried to search for my can of Deoxit, which I would have probably tried instead of sanding the conductors - but, what I did was fine.  Some day, though,  I'll unplug the amp, and spray to tube sockets with Deoxiti and let it dry for several hours.  I bought the LD I+ 2nd hand.  Also, noticed that the rear RCA connectors are tarnished a bit and not really the polished gold color of most RCA connectors.  I guess the amp might have been used in an area that wasn't so good for the various connections.


 
  
 I changed tubes last night and played the song that had been playing when I heard the static.  The static remained, suggesting to me the tube is fine, but the recording is not.


----------



## kvtaco17

wje said:


> Why not just opt for the ODAC?  I was surprised at how well it really performed.  I had the comb unit with the O2 amp, too.  I sold it because there wasn't a way to use just the ODAC and skip the O2 amp in that scenario.  I've used the Schiit Modi too, but with the Magni amp.  The circumstances at the time were not ultimate to do enough testing.  I'd like to hear the Modi again, though - especially with the Little Dot I+ amp.
> 
> Is there a reason for going for a 24Bit DAC?  Do you listen to higher resolution music above regular Redbook CD, which is 16-bit audio?


 
 I second the ODAC... so the stand alone... its awesome, especially for the price... the Modi is good, a lot of people like it, I find it a touch brighter then the ODAC though.


----------



## Artsi

Now this looks little bit different. Can't tell yet anything about sound, just got them.


----------



## bundy

Hi to all,I have just received my ld1+ with stock tubes 6J1 i have also ordered a matched pair of Philips 5654 E95F. my problem is i am totaly new to this tube rolling well to be honest i know nothing at all about tubes. So after ordering & paying for the tubes i noticed they are E95F not EF95 does this make a differance? Everything i have read has said that not only do the 5654 tubes suit my LD1+ i also don't need to change any jump settings from 6J1 ? please help a keen newbee...


----------



## gibosi

bundy said:


> Hi to all,I have just received my ld1+ with stock tubes 6J1 i have also ordered a matched pair of Philips 5654 E95F. my problem is i am totaly new to this tube rolling well to be honest i know nothing at all about tubes. So after ordering & paying for the tubes i noticed they are E95F not EF95 does this make a differance? Everything i have read has said that not only do the 5654 tubes suit my LD1+ i also don't need to change any jump settings from 6J1 ? please help a keen newbee...


 
  
 E95F tubes will be fine. They are equivalent to 5654 tubes, which are special quality EF95. Transposing "95" and "F' is the standard way of indicating higher quality in European tubes. For example, I am currently using ECC88 tubes. E88CC are the special quality versions.


----------



## gibosi

kvtaco17 said:


> I second the ODAC... so the stand alone... its awesome, especially for the price... the Modi is good, a lot of people like it, I find it a touch brighter then the ODAC though.


 
  


wje said:


> Why not just opt for the ODAC?
> 
> Is there a reason for going for a 24Bit DAC?  Do you listen to higher resolution music above regular Redbook CD, which is 16-bit audio?


 
  
 Thanks for your recommendations. I had a chance to try the Modi and found that it was a bit bright and decided against getting one. And many people have said the the Modi and the ODAC sound the same, so I hadn't really considered it....
  
 At this time I really don't need 24Bit, but I feel that optical on my DAC, which is 24Bit, sounded better than USB. But of course, there might be other reasons.....


----------



## MIKELAP

gibosi said:


> E95F tubes will be fine. They are equivalent to 5654 tubes, which are special quality EF95. Transposing "95" and "F' is the standard way of indicating higher quality in European tubes. For example, I am currently using ECC88 tubes. E88CC are the special quality versions.


 
 OK i saw these E88CC so they are in the same family as ECC88 so we can use those also. Thats good


----------



## bundy

gibosi said:


> E95F tubes will be fine. They are equivalent to 5654 tubes, which are special quality EF95. Transposing "95" and "F' is the standard way of indicating higher quality in European tubes. For example, I am currently using ECC88 tubes. E88CC are the special quality versions.


 
 Thank you so much. You have eased my so much, This is my first dabble into tubes i have always been a ss man. but curiosity & illness has led me to the Little Dot1+ with stock 6J1 & i have fallen in love with my music again. Plus i am having spinal surgery i 2 days & i am going to be laid out for about a month so that's a good time to learn this tube rolling & hopefully have some fun in the process, thanks again gibosi
   thanks bundy


----------



## gibosi

bundy said:


> Thank you so much. You have eased my so much, This is my first dabble into tubes i have always been a ss man. but curiosity & illness has led me to the Little Dot1+ with stock 6J1 & i have fallen in love with my music again. Plus i am having spinal surgery i 2 days & i am going to be laid out for about a month so that's a good time to learn this tube rolling & hopefully have some fun in the process, thanks again gibosi
> thanks bundy


 
  
 I wish you a speedy recovery from your surgery, and while you are on the mend, I believe that rolling tubes in your Little Dot will be a great project! 
  
 Cheers


----------



## MIKELAP

gibosi said:


> Thanks for your recommendations. I had a chance to try the Modi and found that it was a bit bright and decided against getting one. And many people have said the the Modi and the ODAC sound the same, so I hadn't really considered it....
> 
> At this time I really don't need 24Bit, but I feel that optical on my DAC, which is 24Bit, sounded better than USB. But of course, there might be other reasons.....


 
http://www.canuckaudiomart.com/details/649083120-audinst_hudmx1_highend_usb_dac_with_headphone_amplifier/
  
http://www.canuckaudiomart.com/details/649081242-brand_new_cambridge_audio_dacmagic_100/
  
 Found this on Canuck AudioMart never heard them but who nows.


----------



## Sony Slave

I have ordered 3 different tubes.
 
6AQ6 SYLVANIA
  
RCA 6DT6/6DT6A
  
1680 IBM 6BE6 
  
Overall which one is the best or another to put it is, what are their strengths and weaknesses?
  
 Also, what is the burn in time for each tube?


----------



## Audiofanboy

Imho, as far as DACs are concerned, I still find the Little Dot DAC_1 to be a very solid performer. I don't know if I would buy it again, two and a half years later, considering all of what's out there, but it's never disappointed me yet!
  
 It's got the same DAC chip (single, not dual) as the Dacmagic, a toroidal transformer, Toslink & Coax inputs for the usual culprits, a pretty good (16bit 48kHz) USB implementation, and also a bonus 75 ohms BNC input (which I've been using for over a year). Like the Dacmagic, you get balanced outputs too.
  
 It's decently priced, excellent if you replace the stock opamps (stock is already a great opamp, but why not use the best?) with two double AD797BR(Z); and a giant killer if you pair it with a quality -battery powered- USB -> S/PDIF interface (which also gets you beyond the 16/48 USB limit).
  
 Sure, there's metric tons of decent sub-$400 DACs nowadays, but few get you a nice DAC chip, a nice power supply, good USB, and also a true 75 ohms input and balanced outputs.
  
 I use a LD DAC_1 with a M2Tech Hiface 2 and my DIY 5V battery pack (easy to make, honestly, and a colossal improvement with the Hiface!), and have -surprisingly- not felt the need for an upgrade yet, which is _very_ unusual for a head-fier...
  
 I probably will breakdown someday, and buy an I2S input DAC with a battery powered USB -> I2S section; but for now and until the technology gets up to par, I'll just stick with the DAC_1...
  
 Speaking of change, I've tested my second no-silk-screen EI ECC83 tube. This one actually has an inner structure that looks closer to and is oriented the same way as the old Telefunken production. It sounds very similar to my other EI tube, but might even be a tad better. I got lucky, since both tubes aren't microphonic at all, but the Yugoslavian quality control is indeed horrible: that second tube actually has a lame pin! At first, it seemed like it has been chopped or broken, but upon closer investigation, that pin is just stuck in the glass, two millimeters above the others!! Lackluster QC at best... Sounds awesome though. Seriously.


----------



## TrollDragon

Great info on the DAC_1, I was pondering this as an addition to the MKIV keeping case style and so forth. Now I don't know, the DAC_1 or an Audio-gd product...


----------



## Nic Rhodes

I am a 'ODAC' fan and use it currently with my 4se test rig. If you are just after a USB input it is a fine product.


----------



## gibosi

Thanks for all the DAC recommendations. I'm not in any hurry, so will take my time to look into them.
  
 Cheers


----------



## Sony Slave

gibosi said:


> Thanks for all the DAC recommendations. I'm not in any hurry, so will take my time to look into them.
> 
> Cheers


 
 Have you looked into the Schiit Modi? $111 shipped new . You can find it even cheaper in the classifieds.


----------



## TrollDragon

This is the choice from Audio-gd and a screaming deal to boot, 32bit 384K USB / Coax / Optical
 http://www.audio-gd.com/Pro/Headphoneamp/NFB1532/NFB15.32EN.htm


----------



## gibosi

sony slave said:


> Have you looked into the Schiit Modi? $111 shipped new . You can find it even cheaper in the classifieds.


 
  
 I actually had a chance to try the Modi and found that it was a bit too bright for my taste. I was quite disappointed as they are a very good buy otherwise.....


----------



## Sony Slave

gibosi said:


> I actually had a chance to try the Modi and found that it was a bit too bright for my taste. I was quite disappointed as they are a very good buy otherwise.....


 
 Tbh, the Bifrost Uber isn't doing much for me either, but I will give it one last shot. This time with some new RCA 6DT6 tubes for the little dot.
  
 Onto another subject though, do any of you guys know the most detailed OP amps out for the Little Dot 1+?
  
 What op amps are you guys running, currently i'm using the lme49990.


----------



## gibosi

trolldragon said:


> This is the choice from Audio-gd and a screaming deal to boot, 32bit 384K USB / Coax / Optical
> http://www.audio-gd.com/Pro/Headphoneamp/NFB1532/NFB15.32EN.htm


 
  
 The LD DAC-I or this NFB-15.32....  An interesting choice. With shipping, both of these units are about the same price. However, one is a dedicated DAC and the other is a DAC/amp. It could be argued that with the NFB-15.32, I am buying something I don't need, the amp, and I wonder how much this unit would cost if it didn't have an amp? But on the other hand, this is listed at a "promo" price and it may well be that this unit usually costs more....


----------



## gibosi

sony slave said:


> Tbh, the Bifrost Uber isn't doing much for me either, but I will give it one last shot. This time with some new RCA 6DT6 tubes for the little dot.
> 
> Onto another subject though, do any of you guys know the most detailed OP amps out for the Little Dot 1+?
> 
> What op amps are you guys running, currently i'm using the lme49990.


 
  
 The LME49990 is the most neutral and detailed op amp I have heard to date. That said, I just pulled the trigger on a MUSES02 as a number of people have rated this op amp even better. However, it was not cheap, so I hope I am not disappointed.....


----------



## wje

trolldragon said:


> This is the choice from Audio-gd and a screaming deal to boot, 32bit 384K USB / Coax / Optical
> http://www.audio-gd.com/Pro/Headphoneamp/NFB1532/NFB15.32EN.htm


 
  
 My take on the offering.  Price is $235.00.  Plus, add in about $45.00 / shipping as well as PayPal fees, and you'll have a "close" accurate estimate to the cost.  I see options for the DAC end and the ESS Sabre is listed.  Normally, on their gear, the ESS Sabre is usually more costly and I suspect the Wolfson, would come standard - or, that's my impression.
  
 Now.  About Audio-GD.  I currently have the "FUN" model, which is similar inside to the Compass / Compass 2 model with respect to power, power supply, etc.   My built in DAC features 2 - Wolfson chips and I'm using the "Earth" op module, which is about their most neutral offering, when compared to the "sun" - a bit more detailed on the upper end, and the "moon" - a bit darker on the frequencies.  I really like it, especially when you can get it for about $200 - $220.  Plus, it has USB, Opitical and Digital coax inputs.  It can be used only as a DAC, only as a AMP / Pre-Amp, or on combination mode: Amp / DAC.  The flavor between the Earth opamp module, and the Wolfson DAC tends to be leading more towards your placement in the front row of a concert.  The mids are strong.  At the moment, I've been using just the amp portion along with my HeadAmp Upsampling DAC.  This DAC tends to be balanced in sound, but with the exception of a bit of extra detail on the top.  When paired with my Little Dot I+ and tubes that I need to check the flavor of, the whole presence isn't as warm as I'd like.  But with HeadAmp DAC with the Audio-GD fun is about as perfect as it gets with my Grado RS1i.
  
 Also, on the forum, there is a member, who has an Audio-GD listed for $275.00.  His is a variant that he purchased from Pacific Valve and they applied some enhancements to those models.  I can't fully explain the enhancements as PV no longer has those details on their Web site.  I know of the member, but don't really have any direct affiliation to the individual and that sale.


----------



## gibosi

Rolled in a pair of Reflector 6N23P, 1969, this evening, and first impressions, these are really nice tubes. The mid range has a nice bit of warmth and sweetness which I am finding to be very enjoyable. However, this is after only 15 minutes or so, so can't really say anything about how they compare to the better-known Mullard, Amperex and Siemens ECC88.
  
 I have read in the Lyr forums that the late 1960's Reflectors are superior to those of the late 1970s and early 80s. So if you decide to pick up a pair of Reflectors, I can say that these 1969 Reflectors appear to be very nice tubes.


----------



## TrollDragon

wje said:


> My take on the offering.  Price is $235.00.  Plus, add in about $45.00 / shipping as well as PayPal fees, and you'll have a "close" accurate estimate to the cost.  I see options for the DAC end and the ESS Sabre is listed.  Normally, on their gear, the ESS Sabre is usually more costly and I suspect the Wolfson, would come standard - or, that's my impression.
> 
> Now.  About Audio-GD.  I currently have the "FUN" model, which is similar inside to the Compass / Compass 2 model with respect to power, power supply, etc.   My built in DAC features 2 - Wolfson chips and I'm using the "Earth" op module, which is about their most neutral offering, when compared to the "sun" - a bit more detailed on the upper end, and the "moon" - a bit darker on the frequencies.  I really like it, especially when you can get it for about $200 - $220.  Plus, it has USB, Opitical and Digital coax inputs.  It can be used only as a DAC, only as a AMP / Pre-Amp, or on combination mode: Amp / DAC.  The flavor between the Earth opamp module, and the Wolfson DAC tends to be leading more towards your placement in the front row of a concert.  The mids are strong.  At the moment, I've been using just the amp portion along with my HeadAmp Upsampling DAC.  This DAC tends to be balanced in sound, but with the exception of a bit of extra detail on the top.  When paired with my Little Dot I+ and tubes that I need to check the flavor of, the whole presence isn't as warm as I'd like.  But with HeadAmp DAC with the Audio-GD fun is about as perfect as it gets with my Grado RS1i.
> 
> Also, on the forum, there is a member, who has an Audio-GD listed for $275.00.  His is a variant that he purchased from Pacific Valve and they applied some enhancements to those models.  I can't fully explain the enhancements as PV no longer has those details on their Web site.  I know of the member, but don't really have any direct affiliation to the individual and that sale.


 

 The 15.32 seems to be only the WM8741 where the 11.32 has the Sabre ES9018 for $299
  
 The Compass 2 is a nice looking unit but the prices start to ramp up quickly and that "FUN" in the F/S section has dropped to $260 or BO, now there is a deal for sure.


----------



## mordy

Hi All,
  
 I'm thinking of a suitable headline for this experience; don't know how to word it:
  
*Scary Moment in Tubeworld*
  
*Disaster in the Mancave*
  
*Listening Room Filled With Acrid White Smoke (exaggeration)*
  
 Anyhow, I was sitting there and doing some paperwork with the music on fairly low volume listening via speakers to Harry's Happy Four from 1925.
  
 Suddenly a pop, the music cuts out, comes back and another pop! Silence. I turn around to see what's going on. White acrid smoke surrounds my receiver and the Little Dot! I immediately switch of all power. Oh no - did I finally kill my beloved Little Dot? Different thoughts flash through my mind - how much is it going to cost to ship it back to China? How will I manage without the beautiful music?
  
 Slowly I try to find out what's wrong. Wait a second; the Little Dot works fine with headphones. Like wise the receiver works with phones, but no sound from the speakers. Where is the problem?
  
 Call my retired engineer friend. I take the cover off the receiver - no visible signs of something burning. He tells me that the best way to find out is to use your nose and smell where the acrid smoke comes from. A smell test of the Little Dot does not tell anything. Now the receiver:
 Yep, it does have a bad electrical burnt smell. I finally locate it to one side of the receiver. My friend tells me that it could be anything; perhaps a blown capacitor due to a faulty transistor. I call the manufacturer - they can't tell me anything over the phone. I find out that it is going to cost me around $200 for shipping and repair. Ouch...
  
 The effects of AMWS start to set in. I can't even listen to the Little Dot because all the wires go through the receiver, and I am advised not to turn on the receiver since it could be dangerous.
 Acute Music Withdrawal Syndrome - What am I to do?
  
 My friend offers to take a look tomorrow but does not know how long it will take to get the parts etc.
  
 Suddenly I remember that I have an old 1980's Sony receiver sitting in the house that one of my kids gave me some 15 years ago after the grandchildren had wrecked the stereo console. (Sony Slave - r u reading this?)
  
 To make a long story short, it is a Sony Integrated Stereo Receiver TA-AX530. 110 Watts/channel. I worry about the warning of not using a DC (Direct Current) Amplifier. But it says Integrated, not DC. On the back are jacks for inserting an equalizer, and I plug in the LD into this circuit. Turn everything on, and then flick the equalizer switch on, ready to cut the power if something explodes.
  
 Success! Whew, don't have to suffer from AMWS. Four speakers are working, but I don't know how to connect my two subs.
  

  


 The sound is fairly good - warm beer vs champagne. I am happy again....


----------



## wje

I just saw a deal on a Little Dot MK III appear in the F/S section within the last 50 minutes.  Complete with box, good shape, etc.  $160, shipping included in price.  I don't have any affiliation with this seller.
  
 I checked the Little Dot sites for this model and it runs $199 + shipping expenses.
  
 Enjoy!


----------



## Audiofanboy

trolldragon said:


> Great info on the DAC_1, I was pondering this as an addition to the MKIV keeping case style and so forth. Now I don't know, the DAC_1 or an Audio-gd product...


 
  
 I actually had the two units (MK IV SE + DAC_1) stacked for a year before having to keep the DAC closer to the computer for technical reasons, and the stacked pile looked pretty good in fact (a bit of blue LED overkill though... I've long since kept a piece of tape of those horrific Chinese LEDs).
  


gibosi said:


> The LD DAC-I or this NFB-15.32....  An interesting choice. With shipping, both of these units are about the same price. However, one is a dedicated DAC and the other is a DAC/amp. It could be argued that with the NFB-15.32, I am buying something I don't need, the amp, and I wonder how much this unit would cost if it didn't have an amp? But on the other hand, this is listed at a "promo" price and it may well be that this unit usually costs more....


 
  
 LD DAC_2 is DAC+Amp, same price, no balanced outputs... I find it often turns out better to just get what you need, let go of the useless freebees, and use the money these extra perks secretly cost to get the best gear you can.
  
 DAC_3 is their crazy year-old unit with balanced digital inputs and I2S inputs. Interesting offering if you know what you're doing with digital signals.
  
 Again, a regular person with regular gear shouldn't blow over $300 on a DAC imo; at least not without a solid transport or music computer rig before that...
  


wje said:


> My take on the offering.  Price is $235.00.  Plus, add in about $45.00 / shipping as well as PayPal fees, and you'll have a "close" accurate estimate to the cost.  I see options for the DAC end and the ESS Sabre is listed.  Normally, on their gear, the ESS Sabre is usually more costly and I suspect the Wolfson, would come standard - or, that's my impression.


 
  
 I'm a big fan of Wolfson chips; they do everything well and couple with any gear nicely. The Sabre chips are probably better overall, but some people just can't get used to them for some reason... I'd love to get a ESS Sabre based DAC one of these days just to change flavors once in a while. We all know the implementation of the chip is just as important as the chip itself in DACs though...
  
 I'll keep my posts relevant and back to tube rolling from here on... Too much distraction around here...


----------



## Nic Rhodes

The Reflector is a nice tube imho but the EV is better again but neither seems to have a following like the Voskhods. The 'basic '6N23P' Voskhod from the 70s seems to be the goto Russian '88' atm but are getting hard to find now and expensive. Two years ago you could hardly give them away! [not tried these on LD yet only other amps]. Just treated myself to some Siemens CCas


----------



## wje

A few days earlier, I had mentioned static being received on one channel of my LDI+ amp.  It was intermittent static.  After cleaning the tube prongs with some emory cloth to clean up the oxidation, the intermittent static went away as mentioned earlier.  However, there was also one other change that I've since noticed.  Both of my tubes now really glow - and, at a consistent level.  Before, it seemed just like was was brighter, and the other a bit dim.  Now, they are both brighter and on par with respect to that brightness being observed on both tubes.


----------



## mordy

Gearing up for using 12AX7 tubes in my rig. So far I got one each of Sylvania 12AX7A and 12AT7 tubes. Also got one each of Syl 12AU7A and 12AZ7A tubes. Would appreciate if somebody could tell me if the last two tubes are compatible with the LD MKIII.
  
 As regards my receiver, turns out that one channel burnt out. Have to send it back to the manufacturer.


----------



## gibosi

I just realized that although I have mentioned my pair of Orange Globe Amperex ECC88, I neglected to post a picture. Of course, they have orange print with an orange globe of the world. These particular tubes were manufactured in 1971. They are said to have an "A-Frame" supporting the getter. And instead of a halo getter, these have a round disk getter with dimples. The earlier Amperex BugleBoys, manufactured in 1960, have white print with the BugleBoy logo, and a metal disk supported on two legs below a halo getter.
  
 While I have not had a chance to critically compare these tubes, my impression is that they are very similar and both are excellent. Further, the BugleBoys and the Orange Globes can often be found for around $25.00 a pair. If you are thinking of trying some 6DJ8 / ECC88 tubes, I strongly recommend both of these.


----------



## Sony Slave

I just received two 6DT6A tubes, one of them are  PHILCO Star light (Ford related) and the  other IEC Mullard (International Electronics Corporation.
  
 Do the tubes have to be matched pairs or from the same company for them to work properly on the Little Dot 1+?


----------



## mordy

Need to buy 9 pin sockets for the "flying" 12AX7 tube. There are many different kinds available. What is better for soldering: a socket with solid tabs , a socket that has holes in the tabs, or a socket saver that comes apart and has pins coming out instead of tabs? Looks like some sockets are one piece, and some two piece. Any advantage of one type over the other?


----------



## wje

sony slave said:


> I just received two 6DT6A tubes, one of them are  PHILCO Star light (Ford related) and the  other IEC Mullard (International Electronics Corporation.
> 
> _*Do the tubes have to be matched pairs or from the same company for them to work properly on the Little Dot 1+?*_


 
  
 I suspect that you would get a somewhat different sound from each channel.


----------



## Sony Slave

Is there something wrong with my Little Dot 1+? Because every single tube that I roll in sounds exactly the same, do you need a quality external DAC to hear the differences. So far I am using music straight from my MP3 player.
  
 I'm even starting to wonder if my Little Dot 1+ is on the right setting.


----------



## Edgard Varese

sony slave said:


> Is there something wrong with my Little Dot 1+? Because every single tube that I roll in sounds exactly the same, do you need a quality external DAC to hear the differences. So far I am using music straight from my MP3 player.
> 
> I'm even starting to wonder if my Little Dot 1+ is on the right setting.


 

 I think the extent to which tubes sound different is probably down to the individual.  I don't usually hear very prominent differences either, though I accept that others do.


----------



## MIKELAP

sony slave said:


> Is there something wrong with my Little Dot 1+? Because every single tube that I roll in sounds exactly the same, do you need a quality external DAC to hear the differences. So far I am using music straight from my MP3 player.
> 
> I'm even starting to wonder if my Little Dot 1+ is on the right setting.


 
 Imo Its mostly subtle differences anyways.


----------



## gibosi

sony slave said:


> I just received two 6DT6A tubes, one of them are  PHILCO Star light (Ford related) and the  other IEC Mullard (International Electronics Corporation.
> 
> Do the tubes have to be matched pairs or from the same company for them to work properly on the Little Dot 1+?


 
  
 I am pretty sure that Mullard did not manufacture 6DT6 tubes and neither did Philco, so these tubes were manufactured elsewhere and simply relabeled. And therefore, in this particular situation, the company name printed on these tubes doesn't really matter. The real question is who manufactured these particular tubes. Do they appear to have the same internal construction? If so, there is a good chance they were manufactured by the same company, and they should work fine as a pair. If not, then they were likely manufactured by different companies, and of course, they are not a good match. So get out your magnifying glass and take a good look at them.


----------



## gibosi

And speaking of subtle differences...  
  
 I have had some time to listen to the Mullard and Amperex ECC88 and the Reflector 6N23P. The Mullards are very good tubes, but given that my HE-300s are somewhat dark, they are just too subdued. The Amperex are a little brighter, with more mid range presence, which compliments my headphones well. The Reflectors are even brighter, but a little too bright for my taste. Further, the Amperex have this wonderful sense of flow, liquid and fluid, which I find very enjoyable. The Reflectors don't seem to flow as well....
  
 So for now, Amperex remains at the top of the heap.
  
 Next up, the Tesla PCC88. As they are NOS/NIB, whereas all my other dual triodes have been used, these need to be burned in....   (>_<)


----------



## Sony Slave

I think my set up is just too dark, Bifrost Uber -----> Little dot 1+  ----------> SRH 840's
  
 I'm going to snatch a Magni once I get the chance, the synergy just doesn't feel right for my headphones.
  
 I will continue messing around with the 1+. The Bifrost is at my friends house 
	

	
	
		
		

		
			





, so when the weekend comes by, I will be able to see if _*I *_really want the little dot.
  
 Also the 6DT6A IEC tube ran VERY hot, the pins were too hot to the touch to hold them. I'm not even going to bother with those.
  
 They have nearly identical construction, the Ford tube is a little different. There are small side getters.


----------



## kvtaco17

sony slave said:


> I think my set up is just too dark, Bifrost Uber -----> Little dot 1+  ----------> SRH 840's
> 
> I'm going to snatch a Magni once I get the chance, the synergy just doesn't feel right for my headphones.
> 
> ...


 
 The Bifrost isn't dark by any means... neither are you 840's... you shouldn't be handling the tubes immediately after operation because they do get hot... that's normal... I'm gonna blame your source. What DAC are you using? What file quality are you using?


----------



## Sony Slave

kvtaco17 said:


> The Bifrost isn't dark by any means... neither are you 840's... you shouldn't be handling the tubes immediately after operation because they do get hot... that's normal... I'm gonna blame your source. What DAC are you using? What file quality are you using?


 
 I am using the Bifrost Uber as the DAC, and  optical out on the PS3.
  
 My files are 320 MP3, AAC, and some flac. They were not upsampled or ripped because all of my music is downloaded from the original source of that particular artist on bandcamp.com .
  
 What does the source have to do with it? I though that the Bifrost would make the source irrelevant since it overrides the DAC on that particular device?
  
 EDIT: I've handled (even though I know I shouldn't) Stock tubes, Tung Sol 6AK5's, Voskods, and GE 5654W tubes after 8 hours of burn it progress. To me they were just warm to the touch.


----------



## kvtaco17

sony slave said:


> I am using the Bifrost Uber as the DAC, and  optical out on the PS3.
> 
> My files are 320 MP3, AAC, and some flac. They were not upsampled or ripped because all of my music is downloaded from the original source of that particular artist on bandcamp.com .
> 
> ...


 
 You said the bifrost was at a friends house... When I said source I meant were you using a PC/CD's/stream/whatever.


----------



## Sony Slave

kvtaco17 said:


> You said the bifrost was at a friends house... When I said source I meant were you using a PC/CD's/stream/whatever.


 
 ok, the music was streamed from the hardrive.


----------



## MIKELAP

mikelap said:


> Imo Its mostly subtle differences anyways.


 
 Mostly but not always what comes to mind is that i changed over my power tubes as ive  been running  my 6N6PIR tubes for a while ,now and i put my Electro Harmonix 6H30 Pi back on hmmm dont seem to like them much anymore because i put the 6N6PIR right back on i like there warm signature better more bass which falls inline if i remember correctly with what has been said before just to say in this case its a lot more than subtle but the 6H30 Pi are very clean sounding and detailed.


----------



## Ryukun

Great guide! Thanks!


----------



## MIKELAP

Hey mordy how many hours do you think your littledot lasted. You say you want to get it fixed is it worth it you think you know Christmas is around the corner, no no not meeee! Santa mordy Santa . lol


----------



## mordy

Hi Mikelap,
  
 The Little Dot is still going strong - it turned out that it was my receiver that blew out a bunch of transistors and resistors - lost one channel and no sound to the speakers, but the headphone output works. I have the Outlaw RR2150 receiver since 2006, and I was very happy with the combination of it and the LD.
  
 My friend told me that my receiver has a direct coupled amp. Little Dot does not recommend using such an amp. I had the LD hooked up via a loop for an external processor and it worked flawlessly for almost three years. I don't know what caused the amp to fail. It is going to cost me around $200 to have it repaired and they said that they would try to diagnose what caused the failure.
  
 Meanwhile I am using an old Sony 1980's amp that I had lying around. It's OK, but not as good as the 2150.


----------



## hypnos1

Hey AUDIOFANBOY, and everyone else on the double triode path...
  
 Re. taking advantage of both triodes : would the 6N2P family not be a good candidate for this route, being a similar spec to 12AX7 (especially with the same mu), but 6.3V and ECC88 pin-out?
 And with some good reports as an ECC 83 'equivalent' (apart from V and pin-out!).
  
 Just a thought...


----------



## gibosi

sony slave said:


> EDIT: I've handled (even though I know I shouldn't) Stock tubes, Tung Sol 6AK5's, Voskods, and GE 5654W tubes after 8 hours of burn it progress. To me they were just warm to the touch.


 
  
 Some tubes run hotter than others. It is just the way it is and it certainly doesn't mean that anything is wrong. Part of the reason the 6AK5 / 5654 are relatively cool is that the heaters are only .175 amps, whereas, the heaters in the 6DT6A are .3 amps. I have run tubes up to .45 amps with no problems, but for sure, they run very hot. Further, if you decide to try 408A tubes, you will find that they too run very hot, with 20 volt heaters, as opposed to 6.3 heaters. But again, this is completely normal....


----------



## Artsi

I have to tell some happy news! 
  
My own designation adapter to 6v and 12v double triodes works! One tube drives both channels and i can easily change between 6v and 12v type tubes with one switch. Just listened couple of minutes JJ electronic ECC83 S tube and can't complain about sound.
  
Little dot 2 reaches another dimensions now. Tube rolling gets cheaper with only one double triode driver. not


----------



## gibosi

artsi said:


> I have to tell some happy news!
> 
> My own designation adapter to 6v and 12v double triodes works! One tube drives both channels and i can easily change between 6v and 12v type tubes with one switch. Just listened couple of minutes JJ electronic ECC83 S tube and can't complain about sound.
> 
> ...


 
  
 This is great news!! But I want to be sure I understand correctly. All I have to do is tie tube-pin 9 to the cathode in both sockets?


----------



## Sony Slave

Here's a nice picture of the little Frankenstein creation I have brought forth to show you guys. As you can see, I didn't go for the usb upgrade, so i'm using this wonderful optical cable... To be honest, looking at this pic makes me not want to sell it. I find this combination with the led lights shining into the shadows to be a very charming duo. I was running the Tung-Sols at the time, the only tubes that actually made a difference in the sound of my 840s.


----------



## MIKELAP

gibosi said:


> Rolled in a pair of Reflector 6N23P, 1969, this evening, and first impressions, these are really nice tubes. The mid range has a nice bit of warmth and sweetness which I am finding to be very enjoyable. However, this is after only 15 minutes or so, so can't really say anything about how they compare to the better-known Mullard, Amperex and Siemens ECC88.
> 
> I have read in the Lyr forums that the late 1960's Reflectors are superior to those of the late 1970s and early 80s. So if you decide to pick up a pair of Reflectors, I can say that these 1969 Reflectors appear to be very nice tubes.


 
 So gibosi how are those 6N23P doing thinking of getting some. and i bidded on some Amperex 6DJ8 you suggested the other day.


----------



## TrollDragon

Alright... Now that you girls have all mastered the Dual Triodes, I want to see someone roll one of these T-1610's in the LD... 
	

	
	
		
		

		
			




  


 Kronzilla hand made in the old Tesla plant in Prague, 128 hours per tube to make...
Nice tour of the plant here.


----------



## MIKELAP

trolldragon said:


> Alright... Now that you girls have all mastered the Dual Triodes, I want to see someone roll one of these T-1610's in the LD...
> 
> 
> 
> ...


 
 Hot Dogs anyone, you can get a sunburn with one of those!


----------



## wje

I was able to make a commitment and went ahead with an order for tubes today.  The Voshkods are what I'll get first to try, then take it from there.


----------



## mordy

My Yugoslavian Ei 6HM5 tubes finally arrived after 17 days. They are easy to use; just set the amp for EF95 and plug them in.
 First impression is that they sound good with strong bass and that the tubes are very musical. Full review has to wait until they are burnt in.
  
 What is most impressive however, is the fireworks display every time I turn on the amp. There is a huge flash that could scare you if you did not expect it, and then the glow dies down to a normal level.
  



 This flash-up happens in a second or so. Set my camera for burst mode to take six pictures at a time. I am apologizing for the blurry pictures but you get the idea.
  
 The other thing is that the build quality seems to be less precise than other European tubes but the sound does not seem to suffer.
  
 Interesting tube.....


----------



## Artsi

gibosi said:


> This is great news!! But I want to be sure I understand correctly. All I have to do is tie tube-pin 9 to the cathode in both sockets?



 


I first connected only left channel B7G socket pin 7 to B9A pin 9 and electro-harmonix 6922 right channel humms. But if i connected same pin from right channel too, all extra noise stopped.


----------



## TrollDragon

mordy said:


> What is most impressive however, is the fireworks display every time I turn on the amp. There is a huge flash that could scare you if you did not expect it, and then the glow dies down to a normal level.
> Interesting tube.....


 
 I found this in another forum on Filament Inrush.
  
 Quote: VacuumVoodoo @ The Gear Page


> There are tubes (some of the SQ and mil spec class) with guaranteed warm up time 11 sec to 80% of the cathodes operating temperature. This was required on tube based tactical equipment that had to have minimal warm up time.
> The initial light flash from the filament is a result of its design. There are also filament designs with guaranteed warm up time that do not flash.


 
  
 It is a normal function of the tube.


----------



## gibosi

artsi said:


> gibosi said:
> 
> 
> > This is great news!! But I want to be sure I understand correctly. All I have to do is tie tube-pin 9 to the cathode in both sockets?
> ...


 
  
 I am still not sure what you mean by "B7G socket pin 7". Pin-hole 7 in the LD socket is not used for these 6-volt double triodes. Are you using modified adapters with pin 7 tied to pin 2?  If so, then I think you are actually connecting tube-pin 9 to adapter-pin 7 which is rerouted to adapter-pin 2 (cathode) in both sockets?


----------



## TrollDragon

artsi said:


> I first connected only left channel B7G socket pin 7 to B9A pin 9 and electro-harmonix 6922 right channel humms. But if i connected same pin from right channel too, all extra noise stopped.


 
 If you are connecting the Dual Triode's internal shield to the Pin 7 on the LD's B7G socket then I would be real careful. In EF95 mode pin 7 connects to nothing, in EF92 mode there is plate voltage on that pin and that would probably not be a good thing to connect to the internal shield.


----------



## Artsi

trolldragon said:


> If you are connecting the Dual Triode's internal shield to the Pin 7 on the LD's B7G socket then I would be real careful. In EF95 mode pin 7 connects to nothing, in EF92 mode there is plate voltage on that pin and that would probably not be a good thing to connect to the internal shield.


 
After some investigations i have come to conclusion that DO NOT CONNECT pin 7 from B7G to anywhere! Electro-harmonix 6922 works with no humming if little dot is in EF92 mode or EF95 and 2-7 strap.


----------



## wje

trolldragon said:


> It is a normal function of the tube.


 
  
 If I had such a pair of tubes, I would also want my regular house lights to dim when the amp was powered on, too ... along with the fireworks of the tube.  Oh wait ... my Grados can only handle about 100mW.  On the other hand, scratch the idea of my house lights dimming when I would power on the amp.
  
 On another note, I had mentioned a few times in posts how the current tubes for my Little Dot I+ were experiencing some noise issues.  I pointed out that I had used a small bit of emory cloth to clean the pins on the tubes.  To a degree, this did make a difference.  However, some noise could still be detected when I used the headphone amp in my bedroom on the night stand.  Next to the amp was my Squeezebox device, along with another electrical device.  When I moved the amp down to my office area, the noise completely disappeared.  Thus, for those who might experience this issue in the future, keep in mind that some interference can be introduced with the tube amp depending on which other electrical equipment might be near it.
  
 Enjoy!


----------



## Artsi

Here is a photo of this hell-machine adapter that allows to use 6.3v and 12.7v heater double triodes (6DJ8 and 12AX7 at least). It could need some finishing and paint. Filled with epoxy and waiting for drying.


----------



## kvtaco17

Well done!


----------



## TrollDragon

kvtaco17 said:


> Well done!


+1 Very Nice!
Now we just need to see the innards.


----------



## TrollDragon

Off to pick up some cold war 6Ж5П's at the post office this AM. Made by Svetlana and probably pulled from the SS-18 Satan ICBM guidance spares... Or would be great to imagine the usage behind these Russian tubes.


----------



## gibosi

artsi said:


> Here is a photo of this hell-machine adapter that allows to use 6.3v and 12.7v heater double triodes (6DJ8 and 12AX7 at least). It could need some finishing and paint. Filled with epoxy and waiting for drying.


 
  
 This looks great, but we would really like to see the inside of your adapter.
  
 In my LD 1+, it does not make any difference if the amp is in the EF92 or the EF95 configuration. Sometimes, there is a ground hum and sometimes there isn't. And it seems to be related to pin 9. When there is a hum, I can usually make it go away if I hold the pin with my fingers. So I think I need to find a way to run a wire from a good chassis ground inside the amp and connect it to pin 9.....


----------



## gibosi

mikelap said:


> So gibosi how are those 6N23P doing thinking of getting some. and i bidded on some Amperex 6DJ8 you suggested the other day.


 
  
 The Reflector 6N23P are really nice tubes. However, they are a bit brighter than the Amperex ECC88, and a little too bright for my taste. But others, who prefer a brighter sound, would like these. And this morning, I finished burning in the Tesla PCC88. These too are very nice tubes, quite similar to the Amperex, but I think the Amperex flow a bit better. That is, the Amperex are a bit more liquid and fluid than the Tesla. So for now, the Amperex are my favorite, and then, Tesla, Reflector, Mullard and Siemens.


----------



## Audiofanboy

Alright, while everyone's now officially jumped onto the ECC88 bandwagon, I'm still investigating the -just as expensive- ECC83 family (12AX7).
  
 Since I proved that these tubes do miracles in my amp, I figured I might as well skip beating around the bush right away (not buy a gazillion $8 tubes and just watch them pile up and never be used) and get the best tube I could in that family directly! If the best doesn't cut it, then the whole family gets publicly shamed. So yeah... I got a Telefunken ECC83/12AX7. And even though I got a "good" deal on it, I'm won't say how much I paid for it lol!
  
 The thing is that the Telefunken 12AX7 tubes aren't rare, but there are like no NOS ones anymore, so people just keep exchanging the same old tubes, and those are just getting weaker and weaker every year... Most of ebay buys or sells pairs that barely test in the good range for $100! It is the land of dubious tube tester results and always-different-values, a land I hadn't known before. Granted, those Telefunken tubes have the reputation of lasting forever -hence the sheer number of used ones available- and even a weak tube can last a lifetime (I've seen the 100000 hours figure a few times, yes that's five zeros).
  
 So basically, I paid a bit extra (again, still an OK deal) to get a very strong -stronger than the nominal "new" values which is still less than the actual "new" values- tube with good silk writing, and from the best time and place: Tele ECC83 made in Berlin around 1960 with ribbed plates and a small logo. I figure I could always sell it for more than what I paid for it anyways, so it's not like it's money lost...
  
 What saddens me is that I'm going to run into the exact same problem with the ECC88/6DJ8 family lol... Yeah, you can get single or pairs of orange globe Amperex for decent prices, but not strong or close to NOS, with a good guarantee of what you're buying or with a good resell value. A pair of Philips Holland ECC88 I'd been looking at on ebay this weekend (tested strong, equivalent to late 60s orange globes) was eventually sold for almost $60! That's just too much for basic used tubes that don't even carry some symbolic brand name like Amp'ex, "Bugle Boys", Telefunken or whatever...
  
 Anyway, the hunt is on, I guess; but I may be done with the "3 pairs every week" craziness lol!


----------



## TrollDragon

audiofanboy said:


> Alright, while everyone's now officially jumped onto the ECC88 bandwagon, I'm still investigating the -just as expensive- ECC83 family (12AX7).
> 
> The thing is that the Telefunken 12AX7 tubes aren't rare, but there are like no NOS ones anymore, so people just keep exchanging the same old tubes, and those are just getting weaker and weaker every year.


 
 The new Black Diamond Series will be out soon for the rolling...


----------



## Audiofanboy

trolldragon said:


> The new Black Diamond Series will be out soon for the rolling...


 
  
 Huh, fascinating! Marketing ploy or true high end new production? Who knows...
  
 What is interesting is that it looks like the frame grid version of the 12AX7/ECC83; it looks like the ECC801S basically (which can cost a 4 digit figure for a pair btw).


----------



## Artsi

gibosi said:


> This looks great, but we would really like to see the inside of your adapter.


 
  
 Sorry but i did not take any photos from inside. I think that the most important thing is how are everything connected.
  
 Left channel B7G to B9A
 5 - 1
 1 - 2
 2 - 3
 3 - 4 via switch
 4 - 5 via switch
  
 Right channel B7G to B9A
 5 - 6
 1 - 7
 2 - 8
  
 B9A pin 9 is connected to switch. Via switch you can take grounding for 6.3v tubes from little dot chassis. And here is a kind of diagram to show how the switch should be connected and how you solder wires to triple ON OFF ON switch. Sorry for non-steady hand and bad drawings.

 I tested also that if switch is in wrong position, heater just won't work and nothing got broken.
  
 Btw, i really like sound of JJ electronic ECC83 S tube, that little what i have had time to listen.


----------



## mordy

Here is a link to these 12AT7 Telefunken branded tubes. It looks to me that these are mainly rebranded GE , National and Phillips tubes. Prices range from $20 to $99 each. They are NOT the real thing but carefully rebranded with the latest Swiss technology to look like Telefunken tubes.
  
 "Impress your friends"
  
 http://www.telefunken-elektroakustik.com/products/tubes/


----------



## Iron58p

I can see the same thing on my couple of Yugoslavian 6HM5 : a flash on one tube for only 1 seconds.
  
 Are very nice and cheap tubes, but today is arrived a couple of Eico GE 6AV6 year 1958, and i'm in love.
http://www.ebay.it/itm/Eico-GE-6AV6-matched-pair-tubes-Very-Rare-12AX7-half-section-GE-Sonics-1958-/281189717133?pt=Vintage_Electronics_R2&hash=item417836948d
  
  
 I think is the same tube 1958 GE owned by Gibosi.
  
 For my ears, this is the "best ever...", all is perfect, soundstage and vocalist positions 3D, sound transparent and detailed, cristal highs and extended, but is an impression of an half hour,
  
 Eico aren't cheap tubes, but if you want to try a couple, soon you will forget the price cost, but not quality sound
	

	
	
		
		

		
			




  
  
  
  
 Quote:


mordy said:


> My Yugoslavian Ei 6HM5 tubes finally arrived after 17 days. They are easy to use; just set the amp for EF95 and plug them in.
> First impression is that they sound good with strong bass and that the tubes are very musical. Full review has to wait until they are burnt in.
> 
> What is most impressive however, is the fireworks display every time I turn on the amp. There is a huge flash that could scare you if you did not expect it, and then the glow dies down to a normal level.
> ...


----------



## gibosi

> Are very nice and cheap tubes, but today is arrived a couple of Eico GE 6AV6 year 1958, and i'm in love.
> http://www.ebay.it/itm/Eico-GE-6AV6-matched-pair-tubes-Very-Rare-12AX7-half-section-GE-Sonics-1958-/281189717133?pt=Vintage_Electronics_R2&hash=item417836948d
> 
> I think is the same tube 1958 GE owned by Gibosi.
> ...


 
  
 Yes, I have these tubes, GE 6AV6 rebranded as EICO. And until I began to roll 6-volt double triodes, I considered these to be my NO 1 tube.


----------



## gibosi

artsi said:


> B9A pin 9 is connected to switch. Via switch you can take grounding for 6.3v tubes from little dot chassis. And here is a kind of diagram to show how the switch should be connected and how you solder wires to triple ON OFF ON switch. Sorry for non-steady hand and bad drawings.


 
  
 Thank you for this! 
  
 And I am now very hopeful that once I can connect pin 9 to the LD chassis ground, I will finally be able to run both triodes in one tube. I currently have a few singles, a Valvo PCC88 with a D-getter (but no visible tube codes), a Siemens PCC88, 1960, and an RCA ECC88, made in Holland, 1974, with a much simpler getter support assembly than the older tubes.


----------



## MIKELAP

Regarding the ECC 83 mod hopefully at one point we will have a detailed how to for the mod visually seeing where the wires go where the ground goes the type of switches used  the type of sockets used ects. and hopefully trying to understand the schematic and what it means .Not being very knowledgeable in electronics dont really understand much but a simplified version with pictures  would help. Of course this takes time so theres no rush just putting it out there it would help others as well i am shure Thanks.


----------



## Artsi

I used switch that looks like this. ON-OFF-ON type was mine, dunno is there just ON-ON available.

 B9A socket, i tried to find best duration for tube rolling, i think.

  
 In ECC83 mod Pin 9 is used as heater center tap. http://en.wikipedia.org/wiki/12AX7. In ECC88 mod it could be grounded, but can't see any reasons for that. I do not hear any humming or additional noise, even by touching tubes.


----------



## TrollDragon

More nice Soviet tubes in the house...
 A quad of Svetlana 6Ж5П's have arrived from a great eBay seller in Bulgaria,
 and it was nice to find all the pins were nicely cleaned before they arrived.

  
 With the box as a backdrop...

  
  


Spoiler: Then you plug it in and the Magic Happens!






  
 Since these tubes can only be run with a 2-7 strap, I took them down to the shop to solder some 30AWG wire wrap wire between pins 2 & 7. With the wire all stripped with a singe wrap around the pin 7, I applied the heat. What resulted was a nice sharp cracking sound, a large rift appeared in the glass and this tube was useless.
 I heated another pin just for for schiit's & giggles, the same thing happened, a nice big crack appeared in the glass.
 Thankfully I picked up 4 of them and I'm glad that this never happened with my USAF 6AH6WA's.
  
 If you pick these tubes up, DO NOT TRY TO SOLDER THE PINS, I didn't attempt a second tube, it wasn't worth the risk.
 I'll just put my switches in EF95 2-7 mode and away we go.


----------



## Artsi

If i thought tube rolling is getting bored, then here is little list of tubes and variants, that should work now with my little dot. List is with heater currents and amplification factors.
  
 6V tube types
  
 ECC88 6DJ8 6N23P CV5358 M3624        0.35A 33x
 E88CC 6922 CCa CV2492 CV2493 9622  0.30A 33x
 E188CC 7308 CV4108                         0.35A 33x
 E288CC 8223                                    0.47A 25X
 ECC85 6AQ8 B719 6L12                      0.44A 57X
 ECC86 6GM8 6N27P                           0.30A 14X
 ECC189 6ES8                                   0.36A 31X
 ECC804 6GA8 6/30L2                         0.30A 18X
 ECC812                                          0.44A 50X
 ECC865                                          0.44A 58X
 ECC180 6BZ7 6BQ7 6BS8 6T27           0.40A 36X
 6N2P 6CC41                                    0.34A 100X
 6BK7                                              0.45A 40X
 6BC8 6BZ8                                      0.40A 35X
 PCC88 7DJ8                                     0.30A 33X
  
 12V tube types
  
 ECC83 12AX7 B339 95-127-01 6L13 CM1        0.30A 100X
 ECC82 12AU7 B329 95-126-01 CC82E CV491  0.30A 17X
 ECC81 12AT7 B152 CC81E CV455                 0.30A 60X
 E81CC 12AT7WA CV6091 6201                     0.30A 60X
 E82CC 6189 M8136 6189W                         0.30A 17X
 E83CC 12AX7WA 6057                              0.30A 100X
 E180CC CV8431 7062                               0.40A 50X
 E181CC                                                  0.40A 32X
 ECC186 12AU7WA 7316                              0.30A 17X
 ECC802S                                                 0.30A 17X
 5751 GL5751 CK5751 CV4017                      0.35A 70X
 5814A CK5814-A                                      0.35A 17X
 5963 CV3900                                           0.30A 21X
 5965 6829                                               0.45A 47X
 6679                                                      0.30A 60x
 7025                                                      0.30A 100X
 12AD7                                                   0.45A 100X
 12DF7                                                   0.30A 100X
 6680                                                     0.30A 20X
 6211                                                     0.30A 27X
 12AZ7                                                   0.45A 60X
 12AD7                                                   0.45A 100X
 12AV7                                                   0.45A 40X
 12AY7 6N4P                                           0.30A 40X
 12DM7                                                   0.26A 100X
 12DF7                                                   0.30A 100X
 12DT7                                                   0.30A 100X
 12U7                                                     0.30A 20X


----------



## gibosi

artsi said:


> If i thought tube rolling is getting bored, then here is little list of tubes and variants, that should work now with my little dot. List is with heater currents and amplification factors.
> 
> 6V tube types
> 
> ...


 
  
 And you can add PCC88 / 7DJ8.


----------



## Artsi

gibosi said:


> And you can add PCC88 / 7DJ8.


 
 Heating is little slower, but it should work.
  
 I added some paint to my "little box". It does not look so much prototype anymore.

 Double triodes do something positive things to music. I listened to Lindsey Stirling and Melody Gardot and nearly cried how good it sounds. Music comes more from outside your head and i easily forget that i wear headphones. Recording studio echos from walls etc seems to be more easily audible.


----------



## mordy

6V tube types
  
 ECC88 6DJ8 6N23P CV5358 M3624        0.35A 33x
 E88CC 6922 CCa CV2492 CV2493 9622  0.30A 33x
 E188CC 7308 CV4108                         0.35A 33x
 E288CC 8223                                    0.47A 25X
 ECC85 6AQ8 B719 6L12                      0.44A 57X
 ECC86 6GM8 6N27P                           0.30A 14X
 ECC189 6ES8                                   0.36A 31X
 ECC804 6GA8 6/30L2                         0.30A 18X
 ECC812                                          0.44A 50X
 ECC865                                          0.44A 58X
 ECC180 6BZ7 6BQ7 6BS8 6T27           0.40A 36X
 6N2P 6CC41                                    0.34A 100X
 6BK7                                              0.45A 40X
 6BC8 6BZ8                                      0.40A 35X
  
 12V tube types
  
 ECC83 12AX7 B339 95-127-01 6L13 CM1        0.30A 100X
 ECC82 12AU7 B329 95-126-01 CC82E CV491  0.30A 17X
 ECC81 12AT7 B152 CC81E CV455                 0.30A 60X
 E81CC 12AT7WA CV6091 6201                     0.30A 60X
 E82CC 6189 M8136 6189W                         0.30A 17X
 E83CC 12AX7WA 6057                              0.30A 100X
 E180CC CV8431 7062                               0.40A 50X
 E181CC                                                  0.40A 32X
 ECC186 12AU7WA 7316                              0.30A 17X
 ECC802S                                                 0.30A 17X
 5751 GL5751 CK5751 CV4017                      0.35A 70X
 5814A CK5814-A                                      0.35A 17X
 5963 CV3900                                           0.30A 21X
 5965 6829                                               0.45A 47X
 6679                                                      0.30A 60x
 7025                                                      0.30A 100X
 12AD7                                                   0.45A 100X
 12DF7                                                   0.30A 100X
 6680                                                     0.30A 20X
 6211                                                     0.30A 27X
  
 And you can add 12AZ7 as well - thanks for your list


----------



## MIKELAP

About 12v tube mod, sockets that go in littledot left and right channel ,do pins 6and 7 have to be cut like in the 6v tube mod.Thanks


----------



## gibosi

artsi said:


> I added some paint to my "little box". It does not look so much prototype anymore.


 
  
 Using an adapter box such as this is the way all of us should be rolling double triodes in our Little Dots. However, exactly how one goes about making such a box is a mystery to most of us. Speaking for myself, I understand very well what needs to be done and it seems simple enough. However, I have no experience in designing and building something like this. I am hopeful that before too long, we will have available to everyone on this forum a parts list and detailed instructions to enable each of us to build a suitable adapter.
  
 Yes, we could keep on mangling pins and cramming 6DJ8 tubes into 7-pin adapters, but this is not optimal (and it won't work at all for the 12-volt double triodes). On several occasions, I have had glass chips break off at the base as a result of bending the pins. And in one case, a crack developed rendering the tube useless. If I could be content to stay with the 6-volt double triodes, and continue to be a "bottom feeder", buying only the cheapest tubes, this is perhaps tolerable. However, I cannot be so content... lol I would really like to try some premium 6DJ8s, but the risk of breaking a tube is too great. And in order to try the 12-volt double triodes, I need a different adapter altogether.
  
 So I am hoping that someone who possesses the necessary knowledge and experience will step forward and provide a detailed step-by-step process to enable us to build such an adapter. In the meantime, I have decided to get something like this:
  
*9-pin breadboard / prototype tube socket for DIY experimenting*
  





  
 This will allow me to make solderless connections to the tube, using the screw / compression terminal blocks. All I have to do is stick the wires in and tighten the screw. And then, I can connect the other ends of the wires to the proper pins in my 7-pin test sockets. I figure it will buy me some time until I can figure out how to make something a bit more functional and elegant like Artsi's "magic" box.


----------



## gibosi

mikelap said:


> About 12v tube mod, sockets that go in littledot left and right channel ,do pins 6and 7 have to be cut like in the 6v tube mod.Thanks


 
  
 My understanding is that we cannot run 12-volt double triodes in our current 6-volt adapters. We need something different that will split the 12-volt supply into two 6-volt supplies, one for each triode.... (>_<)


----------



## Artsi

With my "little box" i used 2 broken tube bottoms as a connection to amp. Those bottoms are glued tightly with epoxy to box. I do not suggest doing this way. Those little wires inside the tubes are pain in the ass to solder with any good connection. I left all pins there, but only needed ones are connected. Box is more steady with more pins. I earlier wrote the list how to connect each pin to B9A socket and heater pins from left channel B7G 3 and 4 go through the switch to B9A pins 4, 5 and 9.
  
 12v heater works the way, that you connect B7G pin 3 to B9A pin 9 and B7G pin 4 to both B9A pin 4 and 5.


----------



## Audiofanboy

Well, at least one thing is for sure now: _the bandwagon is on fire_!
  
 I'm surprised at all the brand new innovative solutions to use double triodes that just popped up here over a few days! Then again, anyone who's tried a few of the tubes recommended here a few weeks ago and _then_ some nice double triodes might feel like he just heard god, so I do understand the sudden passion lol.
  
 Still, I'm left wondering which strategy I should adopt as far as adapting those tubes goes...
  
 12V center tappable tubes would be good candidates for using a -double- tube for each channel, but after doing a bit (actually a lot) of ebay browsing, I've decided that I'd rather get the best even it means both channels have to share one tube because the best is just that expensive. Besides, the tubes, while easy adaptable to a single channel use, do require some major work to do so (moreso than a 6DJ8 tube).
  
 "Regular" 6V double triodes, on the other hand, just aren't meant to be used partially; and as gibosi so clearly worded it, those tubes are just too precious (read expensive) to be mangled and slowly poisoned that way. My own "_ram that son of a tube in a B7G socket, bend his arms and strap its legs_" idea was just meant as a temporary solution to get people on the bandwagon lol. So single tubes would be the way to go for these types. Btw, have we reached any kind of conclusion on not grounding the shield (pin 9) on the 6DJ8? While it seems like good practice to ground it to get less crosstalk/noise/issues, the _internet_ tells many a story of people not caring at all, which leaves me wondering...
  
 I haven't actually tested (or bought) a single 6DJ8 tube yet, just my EI Yugo pairs, so I don't know how they behave with nothing to "isolate" both triodes from each other. 12Ax7 tubes behave perfectly fine used for both sockets; then again, they don't even have a separating shield anyway...


----------



## gibosi

artsi said:


> With my "little box" i used 2 broken tube bottoms as a connection to amp. Those bottoms are glued tightly with epoxy to box. I do not suggest doing this way. Those little wires inside the tubes are pain in the ass to solder with any good connection. I left all pins there, but only needed ones are connected. Box is more steady with more pins. I earlier wrote the list how to connect each pin to B9A socket and heater pins from left channel B7G 3 and 4 go through the switch to B9A pins 4, 5 and 9.
> 
> 12v heater works the way, that you connect B7G pin 3 to B9A pin 9 and B7G pin 4 to both B9A pin 4 and 5.


 
  
 I believe your explanations have been excellent for those who are comfortable constructing electrical projects. 
  
 But for many of the rest of us, we need a process that is simple enough that our "grandmothers" could do it. lol.  
  
 For example, how to we build the box? Is is possible or practical to use a pre-made aluminum or plastic electrical instrument case? But if so, how do we cut the holes? Or perhaps a simple wood box might be the easiest?
  
 And then, since using broken tube bases might not be optimal, it seems to me that we need to figure out how to securely connect two un-modified 7-pin socket adapters (I am thinking of the 7-pin Vector socket adapters with test points) to the bottom of the case. Again, I have no experience with projects like this. I can kind of imagine how it might be done, but I don't know how practical or safe my ideas might be.....


----------



## Audiofanboy

gibosi said:


> I believe your explanations have been excellent for those who are comfortable constructing electrical projects.
> 
> But for many of the rest of us, we need a process that is simple enough that our "grandmothers" could do it. lol.
> 
> ...


 
  
 Silly late night (where I live anyway) idea, but instead of using ugly and hard-to-solder-on B7G broken tube bases (which has been my main future hypothesis to make an adapter for a while now; I've actually have two random tubes sitting on my desk for 6 months just because they have thick inner wires that I thought I could eventually solder on to make B7G adapters), you could just dismantle two Vector socket testers (yes, a waste, I know). Let me explain:
  
 Take your Vectors apart, find two 7-pin pin savers (like the ones that come with NOS UK tubes), put the pins of your dismantled Vector in one of the pin savers with enough length to make the underside (pin length sticking out of the pin saver) look like a regular B7G tube base. Following me? Well, you're luckier than I am; I'm kind of lost and just throwing this out there lol.
  
 Solidify your "pseudo B7G bases) with epoxy or hot glue, and then chop off the length of pin metal you'll need to solder on the upper side of the pseudo-bases. You should get something that looks like a broken B7G tube base but that isn't: it's a clean looking, solid, B7G base with thick metal posts sticking upwards that you should be able to solder on.
  
 I haven't figured the rest out yet; like I said, I'm just throwing some nightly ideas here...
  
 Of course, one could imagine _not_ killing a hard-to-find B7G socket saver, and scavenging pins from elsewhere, but that's an other adventure altogether.
  
 Edit: Extra thought. Vectors may not be completely lost in the process; you could always use the remaining top part and pin length just like before, but without the bottom part... So you'd have a half height socket saver with visible pins, basically (an other pair of pin savers could be used just to make sure the pins actually go straight into a B7G socket and not all over the place. Sorry if I've confused anyone, I'll probably clarify this this weekend after further daytime thinking.


----------



## gibosi

audiofanboy said:


> .......Btw, have we reached any kind of conclusion on not grounding the shield (pin 9) on the 6DJ8? While it seems like good practice to ground it to get less crosstalk/noise/issues, the _internet_ tells many a story of people not caring at all, which leaves me wondering...


 
  
 Using one tube crammed into a 7-pin socket adapter with wires connected to another adapter in the adjacent socket, ground hum is a major problem for me. However, it does not always occur. Perhaps 90% of the time, I get ground hum, but on a few occasions, it has worked perfectly. On the other hand, Artsi reports that grounding pin 9 has not been necessary with his magic box. So perhaps the ground hum problem I am having is related to using a 7-pin adapter with flying pins. Once I get the 9-pin socket mounted on a breadboard I have ordered, I should be able to test this further....
  
 Also, I think your idea of using modified Vector adapters with pin savers would work quite nicely. However, I am still stuck at step number one, trying to figure out how to make an enclosure. I plan to go to a hobby shop today to look around....


----------



## Artsi

I made new THE PRO BOX adapter. I bought made in Canada electric box for it. I took some photos how to make such a thing. This box could be opened afterwards since it is assembled together with 4 screws.

 Here are the most of things you need to make it. 1mm (18gauge) thick copperwire for the pins is covered with lacquer, so it need to be removed first by grinding.

 Here are the parts for the pins. B7G socket is just to keep pins more straight when gel super glueing pins through pin protector/straightener. I grind wire head more round.

 Here it is waiting drying.

 I made holes to bottom of the box. Paper is there protecting little dot from getting any epoxy. You just push pins through paper. I glued parts together with epoxy.

 This show the extra wires for the switch.

 And how the switch is connected to the B9A socket.

 Soldered all rest wires. Cutted those additional copper wires shorter after taking photo.

 And here is ready to use product.
  
 Sharp-eyed can see that i connected heating from both channels. I measured that they are connected anyway inside little dot. So i think with double wiring i can use up to 0.9A heater current.
  
 First wooden box with crappy tube bottoms had very little humming in the right channel with ecc83 tube. It was so little that needed completely silence to notice. Now all humming is gone. I think that there is no need for any kind grounding to pin9 for 6V tubes. Stereo imaging and channel separation is excellent for my hearing.
  
 Enjoy! 
  
 Edit: Box type is 1591MSBK from hammond manufacturing.


----------



## Audiofanboy

artsi said:


> First wooden box with crappy tube bottoms had very little humming in the right channel with ecc83 tube. It was so little that needed completely silence to notice. Now all humming is gone. I think that there is no need for any kind grounding to pin9 for 6V tubes. Stereo imaging and channel separation is excellent for my hearing.
> 
> Enjoy!


 
  
 Great stuff Artsi! Of course, I can't really make a converter box on my amp (MK IV SE) since I have those brass tube protectors... So, I might have to keep using some hybrid strategy in my case. I could probably hide the wires at least though.
  
 So wait, you got hum using a single 12AX7/ECC83? That's odd, since I have had no problem whatsoever with those tube types yet, even connected in very temporary and dangerous ways...!
  
 I really can't see why there would be a "ground" problem with these tubes though, they don't even have a shield ...
  
 Even for ECC88/6DJ8 tubes, I agree that grounding pin 9 or not _shouldn't_ make a difference as far as a "ground hum" is concerned. It should only isolate the two triodes from each others' effects basically. Why only one side of these tubes would hum seems odd to me... Unless the wiring is bad or picking up somekind of intereference or signal or something? Gibosi, when you tried using a single 6DJ8 tubes rammed in one socket and with wires flying to a socket adapter in the other socket, do you get a hum on the other channel when you invert the whole structure? Do you get a hum using a 6DJ8 tube "in the middle", as in with wires connected it to each side? I'm about to buy a premium single 6DJ8 tube, so I'm obviously _very_ interested in the latest developments on this matter lol.
  
 And yes, surprisingly, I find that channel separation and imaging is much better on these "double" tubes than using any single tube I've tested!


----------



## Artsi

audiofanboy said:


> So wait, you got hum using a single 12AX7/ECC83? That's odd, since I have had no problem whatsoever with those tube types yet, even connected in very temporary and dangerous ways...!
> 
> I really can't see why there would be a "ground" problem with these tubes though, they don't even have a shield ...
> 
> Even for ECC88/6DJ8 tubes, I agree that grounding pin 9 or not _shouldn't_ make a difference as far as a "ground hum" is concerned. It should only isolate the two triodes from each others' effects basically. Why only one side of these tubes would hum seems odd to me... Unless the wiring is bad or picking up somekind of intereference or signal or something?


 
  
 There was this little humming with that prototype-box. It could be some interference from somewhere and/or bad connection. And i could not repair it as it was filled with epoxy.


----------



## TrollDragon

Most excellent work Artsi, a job well done for sure!


----------



## Artsi

Now this is something. Using 3x 6N6P-IR tubes at once! Works with no problems.
  
 btw 6N6P-IR as a driver seems to be my first even little microphonic double triode tube... I can hear some noise if i touch tube or knock it with finger nail.


----------



## Audiofanboy

artsi said:


> Now this is something. Using 3x 6N6P-IR tubes at once! Works with no problems.
> 
> btw 6N6P-IR as a driver seems to be my first even little microphonic double triode tube... I can hear some noise if i touch tube or knock it with finger nail.


 
  
 Funny, I thought about trying the same trick with 6N30P-DR tubes, but ended up not because mu would be a little on the low side for driver tubes, and gm would be over the roof (it's already quite high with 6DJ8 tubes)!
  
 How does it sound though, good?


----------



## wje

Excellent Day!   My Voshkod 6ZH1P - EV tubes arrived from Yen this morning via the USPS regular Saturday mail delivery.  I need to spend some time having them burn-in a bit with the Little Dot I+ through the day, and will look forward to a late evening session of checking out the various passages in my music to see how they fare.


----------



## Artsi

audiofanboy said:


> Funny, I thought about trying the same trick with 6N30P-DR tubes, but ended up not because mu would be a little on the low side for driver tubes, and gm would be over the roof (it's already quite high with 6DJ8 tubes)!
> 
> How does it sound though, good?


 
 6N6P-IR and 6N6P-i sounds good. Chinese 6N6 has weird rough electric kind sound with some distortion. I think this is good way to test which powertube sounds good. Problems with sound multiply.


----------



## gibosi

artsi said:


> I made new THE PRO BOX adapter. I bought made in Canada electric box for it. I took some photos how to make such a thing. This box could be opened afterwards since it is assembled together with 4 screws.
> 
> 
> 
> ...


 
  
 GREAT JOB!!
  
 THANK YOU!! 
  
 Since I have never worked with plastic before.... What kind of tool do you use to cut the holes?


----------



## Artsi

gibosi said:


> GREAT JOB!!
> 
> THANK YOU!!
> 
> Since I have never worked with plastic before.... What kind of tool do you use to cut the holes?


 
 I drilled 10mm hole and grinded it bigger. Even with knife it is possible to slowly make such hole. This is possibly the best option http://www.sahkonumerot.fi/6421771/img/large/color.jpg.


----------



## MIKELAP

gibosi said:


> GREAT JOB!!
> 
> THANK YOU!!
> 
> Since I have never worked with plastic before.... What kind of tool do you use to cut the holes?


 
 you use this with a drill makes nice round hole if you can get the right size.


----------



## MIKELAP

artsi said:


> I made new THE PRO BOX adapter. I bought made in Canada electric box for it. I took some photos how to make such a thing. This box could be opened afterwards since it is assembled together with 4 screws.
> 
> Here are the most of things you need to make it. 1mm (18gauge) thick copperwire for the pins is covered with lacquer, so it need to be removed first by grinding.
> 
> ...


 
 Looks great very nice Artsi nice picture . About the connections i have a picture for you , could you link the different sockets with crayon so we can see what wire to solder where when you have a chance .Just make shure i numbered the socket hole correctly first. Thanks a bunch .


----------



## gibosi

mikelap said:


> you use this with a drill makes nice round hole if you can get the right size.


 
  
  


artsi said:


> I drilled 10mm hole and grinded it bigger. Even with knife it is possible to slowly make such hole. This is possibly the best option http://www.sahkonumerot.fi/6421771/img/large/color.jpg.


 
  
 Thanks guys! Now I know what I am looking for.


----------



## Artsi

mikelap said:


> Looks great very nice Artsi nice picture . About the connections i have a picture for you , could you link the different sockets with crayon so we can see what wire to solder where when you have a chance .Just make shure i numbered the socket hole correctly first. Thanks a bunch .


 
 B9A numering is wrong. Looking from like bottom of the tube numbering goes clockwise. Switch could be ON-ON type, but has only 6 pins. ON-ON switch with 9 pins works. I need go to sauna...


----------



## MIKELAP

Would this be better .Thanks


----------



## Artsi

hope this helps a little.


----------



## MIKELAP

artsi said:


> hope this helps a little.


 
 Thanks a lot .


----------



## TrollDragon

LOL! You two are ingenious!
Bravo!


----------



## TrollDragon

Artsi...
  
 Sorry but I have a bit of a problem with bridging the heater pins on the B7G sockets together...
  
 Here is the label off the transformer in my MK IV.

 Wire Translation:
  
 The driver filament winding is the 3.3 V * 2/1A so I personally wouldn't use a tube that has a 0.9A draw...
 The wire designation of the 3.3 is Green / Black / Green which tells me it's a 3.3V center tap.
 The power filament winding is the 6.8V/2.5A on the White / White.
 AC to the on board bridge is the 175/0.1A Yellow / Yellow wires.
  
 Is the transformer on your MK II the same?
  
 It is possible that on the above transformer they have the 2 x 3.3V windings in series to get 6.6v and are sending one set to each tube.
 I really don't want to unbolt the my transformer from the chassis to check how they are dealing with these center taps and 3.3V winding wires.
  
 Paralleling the windings can be a problem sometimes.
Rod Elliott (ESP)


> Parallel connection of transformer windings is permitted in one case only - the windings must have exactly the same voltage output, and must be connected in phase. Different current capacities are not a problem, but it is rare to find a transformer with two windings of the same voltage but different current ratings. Even a 1V difference between winding voltages will cause *big* problems. A typical winding resistance for a 5A winding might be 0.25 ohm. Should two such windings be connected in parallel, having a voltage difference of 1V, there will be a circulating current limited only by the resistances of the windings. For our example, the total winding resistance is 0.5 ohm, so a circulating current of 2A will flow between the windings, and this is completely wasted power. The transformer will get unexpectedly hot, and the maximum current available is reduced by the value of the circulating current.
> Should the windings be connected out of phase, the circulating current will be possibly 100A or more, until the transformer melts or the fuse blows. The latter is generally to be preferred.
> The transformer manufacturer's specifications will indicate if parallel operation is permitted. If you are unsure, measure the voltages carefully, and avoid parallel connection if the voltages differ by more than a couple of hundred millivolts. There will always be a difference, and only the manufacturer's winding tolerances can predict what it will be. With toroidal transformers, the windings are often bifilar, meaning that the two windings are wound onto the transformer core simultaneously. The tolerance of such windings is normally very good, and should cause no problems.


 

 Can you see if you have the same label on your transformer, you just have to take the top cover off and it should be right there.
  
 Thanks!


----------



## Artsi

trolldragon said:


> Artsi...
> 
> Sorry but I have a bit of a problem with bridging the heater pins on the B7G sockets together...


 
 Have you measured resistance between channels pins 3 and 4? With my MK II resistances are about 0.1ohms. Transformer cover is too complicated to take apart.
  
*The most reliable way to do the adapter is to use heater wiring only from one channel.*


----------



## Audiofanboy

Alright! I managed to find a single, super strong (as in 20% over NOS) Amperex "Orange Globe" 6DJ8 from the late 60s (so not a "Bugle Boys" 6DJ8 from the early or mid-60s, and not an "Orange Globe" with an A-frame getter from 70 onwards), so the best Amp'ex short of some crazy rare tubes, recommended by all who have tried them. I just communicated with a seller who was selling some very nice pairs for "OK" prices, asked him if he had singles, and obviously he had plenty and was willing to sell them for less than half of the price of a pair (cheaper than buying pairs, which is a bit ironic).
  
 Keeping up on my strategy of just going for it and getting the best -instead of spending the same money on more tubes I'll never use- I got the best I could, basically. But even then, I don't find the prices that shocking really, compared to the 3 digit legends I see over on the Lyr thread (I ended up paying $42 for the tube, shipping to France included, and that's $10 right there; seller would have shipped for $37 to the US, which really isn't horrible for super strong premium tubes). Again, I think the "pair effect" really ramps up the prices, and sellers are just dying to sell single tubes they don't have a match for!
  
 About heater wiring to adapt a single tube instead of two, it does feel more natural and "safe" to just use the 6V heater pins on one side and just be done with it. Besides, it's also easier!


----------



## gibosi

artsi said:


> And here is ready to use product.


 
  
 I want to give a HUGE shout-out to Artsi for showing us how to make an adapter box to allow us to easily use these double triodes in our LDs. If anyone wants to use these tubes (And everyone SHOULD want to use these tubes! They are THAT GOOD!), all that is necessary is to purchase a few parts and supplies, solder a few wires, and _voila_ -- you have a "magic box"!


----------



## siles1991

gibosi said:


> I want to give a HUGE shout-out to Artsi for showing us how to make an adapter box to allow us to easily use these double triodes in our LDs. If anyone wants to use these tubes (And everyone SHOULD want to use these tubes! They are THAT GOOD!), all that is necessary is to purchase a few parts and supplies, solder a few wires, and _voila_ -- you have a "magic box"!


 
 most interesting though I wonder if its possible to add in more sockets whereas the switch allows us to switch between EF95 tubes and the double triodes. So there would be three sockets middle will have the double triode and the left and right side will be our regular EF95's(eg. 6dt6a, EH90, 6AH6WA)


----------



## gibosi

siles1991 said:


> most interesting though I wonder if its possible to add in more sockets whereas the switch allows us to switch between EF95 tubes and the double triodes. So there would be three sockets middle will have the double triode and the left and right side will be our regular EF95's(eg. 6dt6a, EH90, 6AH6WA)


 
  
 Of course, this is possible, but I think it would be more complicated and difficult than it is worth. As this box simply plugs into your sockets, if you want to listen to a 6DT6A, all you have to do is unplug the box, set it aside, and then use your LD as normal.


----------



## siles1991

gibosi said:


> Of course, this is possible, but I think it would be more complicated and difficult than it is worth. As this box simply plugs into your sockets, if you want to listen to a 6DT6A, all you have to do is unplug the box, set it aside, and then use your LD as normal.


 
 ah icic i thought it was permanently rigged on the lil dot xD


----------



## mordy

Hi Artsi,
  
 If I wanted to listen to a 12AT7 tube using the schematic for your box, what is the purpose of the on-off-on 9 pole switch?
  
 Is this the same switch?
  
 http://www.ebay.com/itm/140923600452?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649
  
 And is this the box?
  
 http://www.ebay.com/itm/281036052511?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1438.l2649
  
 Thanks,


----------



## siles1991

mordy said:


> Hi Artsi,
> 
> If I wanted to listen to a 12AT7 tube using the schematic for your box, what is the purpose of the on-off-on 9 pole switch?
> 
> ...


 
 I think any 3pdt switch with on-off-on would work though agreed whats the use? a dpdt should work just fine for this application.


----------



## MIKELAP

mordy said:


> Hi Artsi,
> 
> If I wanted to listen to a 12AT7 tube using the schematic for your box, what is the purpose of the on-off-on 9 pole switch?
> 
> ...


 
 Hey mordy you have the right part number as long has you buy1591 msbk that one sustains heat the 1591S not made for that purpose it seems. You can also get it and the switch at DIGIKEY box sizes 3.339L x 2.205W x 1.023H INCHES


----------



## Artsi

mordy said:


> Hi Artsi,
> 
> If I wanted to listen to a 12AT7 tube using the schematic for your box, what is the purpose of the on-off-on 9 pole switch?
> 
> ...


 
 Purpose of the switch is that you can use 12.6v and 6.3v heated tubes. There are few 12v tubes that do not have possibility to use with 6.3v. And i noticed few 6.3v tubes that have possibility to be used with 3.15voltage, and this tubetype could break if switch is in wrong position. Switch looks right one, but the box is much bigger, what i used. My box is 1591MSBK. Switch could be ON-ON type too.


----------



## gibosi

audiofanboy said:


> Alright! I managed to find a single, super strong (as in 20% over NOS) Amperex "Orange Globe" 6DJ8 from the late 60s (so not a "Bugle Boys" 6DJ8 from the early or mid-60s, and not an "Orange Globe" with an A-frame getter from 70 onwards), so the best Amp'ex short of some crazy rare tubes, recommended by all who have tried them. I just communicated with a seller who was selling some very nice pairs for "OK" prices, asked him if he had singles, and obviously he had plenty and was willing to sell them for less than half of the price of a pair (cheaper than buying pairs, which is a bit ironic).
> 
> Keeping up on my strategy of just going for it and getting the best -instead of spending the same money on more tubes I'll never use- I got the best I could, basically. But even then, I don't find the prices that shocking really, compared to the 3 digit legends I see over on the Lyr thread (I ended up paying $42 for the tube, shipping to France included, and that's $10 right there; seller would have shipped for $37 to the US, which really isn't horrible for super strong premium tubes). Again, I think the "pair effect" really ramps up the prices, and sellers are just dying to sell single tubes they don't have a match for!


 
  
 I have a pair of Bugle Boys, 1960, and A-frame Orange Globes, 1970, and to my ears the Bugle Boys sound better. Based on the reviews of others and my experience, Amperex with halo getters from the early sixties through the late sixties do seem to be better than the later A-frame versions. 
  
 And speaking of going for the best, I found a pair of white label Amperex 6922 / E88CC, relabeled as Beckman, with gold pins, made in the US, for $83.00, including shipping. I have seen these for upwards of $200 a pair, especially if they carry the Amperex label. However, as we have seen many times, the label on a tube is not all that important. Gold pins and the Philips tube codes tell us everything we need to know: In this instance "7L9 *4J"    7L= 6922 / E88CC, 9 = change code, * = Amperex, New York, 4 = 1964, J = October.


----------



## Audiofanboy

gibosi said:


> I have a pair of Bugle Boys, 1960, and A-frame Orange Globes, 1970, and to my ears the Bugle Boys sound better. Based on the reviews of others and my experience, Amperex with halo getters from the early sixties through the late sixties do seem to be better than the later A-frame versions.
> 
> And speaking of going for the best, I found a pair of white label Amperex 6922 / E88CC, relabeled as Beckman, with gold pins, made in the US, for $83.00, including shipping. I have seen these for upwards of $200 a pair, especially if they carry the Amperex label. However, as we have seen many times, the label on a tube is not all that important. Gold pins and the Philips tube codes tell us everything we need to know: In this instance "7L9 *4J"    7L= 6922 / E88CC, 9 = change code, * = Amperex, New York, 4 = 1964, J = October.


 
  
 This is definitely getting to be a more and more expensive hobby... Less tubes but 5-10 times more expensive than the previous types! It's not that bad though: I ended up getting free international shipping on my Amperex tube, so I paid $37/28€, which is the price of a few beers in town where I live...
  
 Seller is http://www.ebay.com/usr/mercedesman6572 . Very good seller imo (and I've seen people on the Lyr thread say the same), just communicate and he should be able to get you virtually _any_ single 6DJ8 you want -for a price of course, this isn't Grandpa's attic lol.
  
 People say that the early to mid 60s Holland-made Amperex tubes -Bugle Boys- are some of the most musical you can find, but, while very nice, aren't the last word in terms of microdetail and both upper and lower frequency extension (despite a slight upper bass "hump", _or so I've read_). That's probably what makes them so musical and euphonic though.
  
 Late 60s -Orange Globes- with a halo getter are supposed to have better extension, and much better "precision" or focus, at the expense of some degree of musicality (still quite musical though).
  
 70s A-frame getter Amperex are a bit more forward (vocals are anyway), with more emphasis on highs, and maybe more "perceived" detail as the tubes above, with a bit less focus. Some people prefer the A-frame Orange Globes to the halo getter late 60s ones, but most people either prefer the late 60s version or the more musical Bugle Boys. Speaking from my own limited experience with Philips group ECC88 tubes (my EI Yugo ECC88 with an A-frame getter, very very close to Holland production), I do find that the later A-frame tubes are too forward and a little spiky for my tastes. I've read that EI version is even more forward than the original Philips/Amperex, but the treble emphasis is exactly like what I read about those 70s A-frame Amp'ex tubes.
  
 Nice catch on the US Amp'ex tube, gobosi. I'm going to wait until I get my late 60s Orange Globes before I decide whether or not it's worth forking out more money for ECC88 tubes in my amp (either as opposed to 12AX7 tubes, or as opposed to just being happy with what I have!). Right now, I still can't believe how good my anonymous looking EI ECC83 with smooth Telefunken plates sound. I'm finally taking pleasure from listening to music again, instead of the old burn-in -> swap tubes -> burn-in -> swap tubes -> burn-in cycle of hell where nothing ends up sounding good after a while...


----------



## MIKELAP

mikelap said:


> Here are intructions on how to modify 6BQ7A or ECC/6DJ8 DOUBLE TRIODE tubes and the sockets they use.Its not pretty but it works. Pins 1-2-3-9 need to be bent or cut off on 6BQ7A tubes or if you are using ECC/6DJ8 and Littledot has to be on EF95 setting. you need to insert in a sequence tube pin 4-5-6-7-8 into pin holes 3-4-5-6-7 of the adapter and insert adapter in Littledot in regular position (remembering that there is 2 pins that were cut off on the adapter)                                                                                                                                                                                                                                                            Regarding socket mod ;using  wire solder pin 6 to pin 1 and pin 7 to pin 2 on adapter .Also you will need to cut  pins 6 and 7  those are the pins on the adapter that go in the Littledot. One last thing you can link pin 6 to 1 and 7 to 2 inside the adapter also for a cleaner look using 30 gauge wrapping wire .Wire used in picture is 22 gauge which is to big .                                                                                                                                                                                                                                                                                                                                                                                                                            Of course soldering the wires inside his not easy for a novice also you have to reinsert the pin assembly into socket holes which is loads of fun.ALSO ALWAYS REMEMBER THOSE WIRES HAVE ELECTRICITY PASSING THRU THEM SO BEWARE DO NOT TOUCH THE CONNECTIONS WHILE USING AMP.By the way a special thanks to Audiofanboy,gibosi, and Troll Dragon for there advice, instructions,and patience .Thanks guys.


 

 New improved found some 30 gauge wire so now small enough to solder inside socket adapter. Nice clean job. Also if you can get a small vise and a pin straightner you insert your pins in it and put it in the vise makes a good holder when you solder and your hands are free.


----------



## Artsi

Made possibly better instructions for doing the box. http://www.head-fi.org/t/686893/how-to-make-an-adapter-to-use-double-triode-tubes-with-little-dot-mk-i-iv


----------



## gibosi

audiofanboy said:


> Nice catch on the US Amp'ex tube, gobosi. I'm going to wait until I get my late 60s Orange Globes before I decide whether or not it's worth forking out more money for ECC88 tubes in my amp (either as opposed to 12AX7 tubes, or as opposed to just being happy with what I have!). Right now, I still can't believe how good my anonymous looking EI ECC83 with smooth Telefunken plates sound. I'm finally taking pleasure from listening to music again, instead of the old burn-in -> swap tubes -> burn-in -> swap tubes -> burn-in cycle of hell where nothing ends up sounding good after a while...


 
  
 Similarly, I am also wondering if my long tube rolling marathon might finally be coming to an end.... Having listened now to a number of ECC88s -- Mullard, Amperex, Siemens, Reflector and Tesla -- I find that I prefer the Amperex sound. However, even though my Amperex Bugle Boys sound incredibly good, I thought I might try to find some late 1960s Orange Globes, similar to the ones you have just ordered. Plus, I am not sure how much success I will have re-straightening the pins on my Bugle Boys, so I thought I would like to have some nice Amperex to listen to once I get my 9-pin adapter put together.
  
 In my search for the OGs, I stumbled across the Amperex-USA 6922 / E88CC. Reviews I have read suggest these are among the best. And it seems to me, that if I prefer the sound of Amperex ECC88s, I might also prefer the sound of a premium Amperex over a premium Siemens or others. Plus, the price was right... 
  
 Of course, even if I am close to the end of this marathon, there are still a few other tubes I would like to try. I have read some very good reviews of Voskhod 6N23P from the 1970s. And of course, I want to try at least a few 12AX7.


----------



## hypnos1

Hi all.
  
 After artsi's wonderful work on the switch box, the natural-born pessimist in me is coming to the fore and pushing me to play 'devil's advocate'...
  
 I may well be worrying unduly, but I am reminded of the wise statement in a related field of sound reproduction - namely : the best connector is NO connector.
 Applying this principle to such a box, could we be degrading our signal transfers somewhat...especially if top grade wire isn't used, along with (possible) so-so soldering?
  
 Perhaps I am barking up the wrong tree? (I know I am sometimes barking MAD!!).
  
 Ah well, just a thought...
  
 There certainly is some SERIOUS work going on in triode land at the moment - it's hard to keep up!
  
 Keep up the good work lads - am still awaiting my sockets from China so I can see/hear what all the fuss is about...can't wait...


----------



## gibosi

My 9-pin breadboard socket assembly arrived today.
  
 And it looks pretty ugly, but it is working! lol. I found that leaving pin-9 floating still results in ground hum. But when I tied it to the cathode of the right 7-pin adapter (which is the same adapter which supplies the heaters), everything is fine. So I suspect that pin-9 just does not take kindly to being left completely disconnected. Tying it to the switch in Artsi's magic box or to the cathode in my setup makes it happy.  
  
 Nothing is soldered. I used 28 gauge (.32mm) solid core wire and wrapped one end tightly around the test points on the 7-pin adapters, and then connected the other to the 9-pin breadboard compression terminal blocks. 
  
 And of course, this is very temporary until I get around to building myself one of Artsi's magic boxes.... 
  
 Testing with an RCA / Amperex (Holland) 6DJ8 from 1974. I think this was manufactured after the A-frame versions as it has a much simpler getter structure. The sound is a bit brighter than my Bugle Boys, but still very nice.... and it works! 
  
 Edit: changed catheter to cathode. lol


----------



## MIKELAP

hypnos1 said:


> Hi all.
> 
> After artsi's wonderful work on the switch box, the natural-born pessimist in me is coming to the fore and pushing me to play 'devil's advocate'...
> 
> ...


 
 My concerns reading posts are about possible transformer issues if a surge would occur would like to be 100% reassured on that before making ¨THE BOX¨ . Thanks


----------



## Audiofanboy

gibosi said:


> Similarly, I am also wondering if my long tube rolling marathon might finally be coming to an end.... Having listened now to a number of ECC88s -- Mullard, Amperex, Siemens, Reflector and Tesla -- I find that I prefer the Amperex sound. However, even though my Amperex Bugle Boys sound incredibly good, I thought I might try to find some late 1960s Orange Globes, similar to the ones you have just ordered. Plus, I am not sure how much success I will have re-straightening the pins on my Bugle Boys, so I thought I would like to have some nice Amperex to listen to once I get my 9-pin adapter put together.
> 
> In my search for the OGs, I stumbled across the Amperex-USA 6922 / E88CC. Reviews I have read suggest these are among the best. And it seems to me, that if I prefer the sound of Amperex ECC88s, I might also prefer the sound of a premium Amperex over a premium Siemens or others. Plus, the price was right...
> 
> Of course, even if I am close to the end of this marathon, there are still a few other tubes I would like to try. I have read some very good reviews of Voskhod 6N23P from the 1970s. And of course, I want to try at least a few 12AX7.


 
  
 Yeah, we still need to at least find out whether the 6DJ8/ECC88 or 12AX7 family are better suited for our LD amps! It's basically the reason why I just ordered a "top tier" -hopefully "god tier" lol- tube from each family.
  
 Up to here, with two fairly comparable tubes from each family (both EI tubes based on the machinery that made the exact same "top tier" tubes I ordered), I am definitely preferring my 12AX7 tube! But, there is no doubt that -in the right circuits, with the right gear, blah, blah, blah- the 6DJ8 family is superior to the 12AX7 from a critical perspective. However, the LD circuits could be better suited for one type (it would almost be odd if the amp could run those two very very different tube types in the same great way, if only because of their dramatically different mu/gm figures; but the amp is pretty versatile in the first place, being able to run low mu/mid gm EF95 tubes, oddball mid mu/mid gm EF92 and high mu/high gm EF91, and of course all those crazy tubes we added to the list...).
  
 Like I said, I think I might wait until I have my "top standard" tube for each family before I do _anything _else. My hopes are that I'll be able to immediately eliminate a tube family and save a bunch of money lol!


----------



## Audiofanboy

hypnos1 said:


> Hi all.
> 
> After artsi's wonderful work on the switch box, the natural-born pessimist in me is coming to the fore and pushing me to play 'devil's advocate'...
> 
> ...


 
  
 The same thing occurred to me about any effects on sound quality that the extra -poor?- wiring could have. But seeing how crappy most tube pins are (a far cry from cryo OCC copper lol!) in the first place, and how thin the wiring inside a tube is, I just can't think that it could degrade the signal that much...
  
 If the inner cabling in the amp were premium, I might start worrying about it, but most of it is just PCB tracings or basic wiring anyway. I would, however, try and keep the extra wiring length at a minimum, if only out of interference concerns. These are wires that are out of the amplifier "Faraday cage", so it would be good practice to only use as much as you need (and/or shield them for experts). In the my current, semi-permanent, "mod", counting the socket savers, I only have upwards of 10cm / 4" of total extra length between the original sockets and tube pins, so nothing world-altering imo (if your soldering and connections are at least decent, obviously).
  


gibosi said:


> My 9-pin breadboard socket assembly arrived today.
> 
> And it looks pretty ugly, but it is working! lol. I found that leaving pin-9 floating still results in ground hum. *But when I tied it to the catheter of the right 7-pin adapter (which is the same adapter which supplies the heaters), everything is fine*. So I suspect that pin-9 just does not take kindly to being left completely disconnected. Tying it to the switch in Artsi's magic box or to the catheter in my setup makes it happy.
> 
> ...


 
  
 So wait, where did you connect pin 9 finally, on one the two unused pins of the socket saver that provides the heater current? Like, pin 7 of that socket (that isn't connected to anything, right)?


----------



## gibosi

audiofanboy said:


> So wait, where did you connect pin 9 finally, on one the two unused pins of the socket saver that provides the heater current? Like, pin 7 of that socket (that isn't connected to anything, right)?


 
  
 I remember reading that pin-9 should be tied to ground, or to one of the catheters. Since I do not yet have a suitable chassis ground connection, I tied pin-9 to pin-8 which is connected to the catheter in the right socket. And on the chance it might be relevant. I thought I should point out that I am using the right socket to supply heater current. I haven't tried the other catheter. I am still so thrilled that it is working that I don't want to change anything! lol


----------



## Audiofanboy

gibosi said:


> I remember reading that pin-9 should be tied to ground, or to one of the catheters. Since I do not yet have a suitable chassis ground connection, I tied pin-9 to pin-8 which is connected to the catheter in the right socket. And on the chance it might be relevant. I thought I should point out that I am using the right socket to supply heater current. I haven't tried the other catheter. I am still so thrilled that it is working that I don't want to change anything! lol


 
  
 Ooh, connected to the one of the _cathodes_, I see, that makes sense; it's like shielding in a cable -connected to the source side and left "floating" at the other end. I just couldn't understand what you meant by catheter, I kept thinking about some medical looking tubing lol...
  
 Hopefully, having the shield connected to only one of the two cathodes shouldn't have an audible effect, as it would be outside of the triode assembly (i.e., not between the triode elements).


----------



## gibosi

audiofanboy said:


> Ooh, connected to the one of the _cathodes_, I see, that makes sense; it's like shielding in a cable -connected to the source side and left "floating" at the other end. I just couldn't understand what you meant by catheter, I kept thinking about some medical looking tubing lol...
> 
> Hopefully, having the shield connected to only one of the two cathodes shouldn't have an audible effect, as it would be outside of the triode assembly (i.e., not between the triode elements).


 
  
 Catheters... Cathodes... What was I thinking?  lol 
  
 And if there is an audible effect, I certainly can't hear it. I have been listening for the past hour and so and it sounds great.


----------



## gibosi

mikelap said:


> My concerns reading posts are about possible transformer issues if a surge would occur would like to be 100% reassured on that before making ¨THE BOX¨ . Thanks


 
  
 If the possibility of having the switch in the wrong position is a concern to you, then I would suggest building two boxes with no switch: one for 6DJ8 and one for 12AX7. They are cheap to build, and having one for each tube family completely eliminates the possibility of selecting the wrong heater current.


----------



## MIKELAP

gibosi said:


> If the possibility of having the switch in the wrong position is a concern to you, then I would suggest building two boxes with no switch: one for 6DJ8 and one for 12AX7. They are cheap to build, and having one for each tube family completely eliminates the possibility of selecting the wrong heater current.


 
 So if on 6 volt position you can use 6dj8 tubes whithout having to cut pins is that right .


----------



## gibosi

mikelap said:


> So if on 6 volt position you can use 6dj8 tubes whithout having to cut pins is that right .


 
  
 This is true. You do not have to cut any pins. The two 7-pin adapters I am using have not been altered in any way. In each adapter, I am using pins 1 (grid), 2 (cathode) and 5 (plate) to connect the tube's two triodes to the Little Dot. And on the right adapter, I am also using pins 3 and 4 to supply heater current to the tube. And then on the tube itself, I am connecting pins 8 and 9 to eliminate ground hum.
  
 So your 6DJ8 adapter would do exactly what I am doing here. And while it looks like a complicated mess, it is in fact pretty simple.


----------



## TrollDragon

I am going to play "Devils Advocate" as well...
  
 All this dual triode stuff is really great, *BUT* caution needs to be used in the selection of the tubes used. Rolling most of the 7 pin tubes were no problem, but with the 9 pin tubes you can be exceeding the design specs of the amplifier's transformer. Which is my main concern as I don't want to see any ones amplifier stop working.
  

  
 The transformer label from my MK IV shows that the driver filament maximum current is 1Amp, this would be split between the two sides.

 This transformer is a custom made one either for or by Little Dot themselves. With China being notorious for bad labeling, out of spec / poor tolerances and minimal quality control, the 0.5A rating could be anywhere from 0.4A to 0.6A all depending on who was running the toroid winding machine that day. The LD's are designed to use tubes that draw less that 0.3A and most of the tubes suggested in the manuals to roll are in the 0.175A or 0.2A range which is well below the 0.5A theoretical winding output.
  
 Some of the dual triodes are very close to or are exceeding the maximum current for the winding depending on the tolerances of the transformer. The 6V duals such as E288CC / 8223 draws a filament current of 0.47A and the ECC85 / 6AQ8 / B719 & 6L12 draws 0.44A. If all was good and transformer tolerances were tight, even then these two are pushing the edge of the maximum current. Which will cause the winding to heat up and open one day leaving you with a cold tube and no filament power.
  
 I doubt LD will sell you a replacement transformer, they might... If they don't, you would have to spec one out through one of the transformer manufacturers online. Which might in turn have to be a custom One Off build and that would not be cheap. There are probably lots of ready made ones on the shelf but they will not have the right dimensions to fit in the housing or they will have extra windings etc...
  
 I still have an issue concerning this 6V/12V switch as there are 12V dual's that can draw current on the edge of maximum as well such as the 12AD7 drawing 0.45A.
 Someone should really measure the current on a 12V tube to make sure it is not running too high.


 Any Multimeter should do, just put it on the AC amps function and insert it between the center tap of the tube filament and the pin that usually connects there.
  
  
 I am really not here trying to discourage anyone from playing with the dual triodes, and I am not here to spread the doom and gloom, it's just people should be aware of what the consequences might be if they decide to join in on the fun. It is good to see that the bridged filaments were discontinued as that had me concerned, since there are people trying the duals that have very little electronic knowledge.
  
 In my opinion I would stick to the 6V / 0.35A or less tubes to minimize the chance of possible transformer failure and forget about implementing the switch unless you know for a fact what the current draw is and you understand how to wire such a switch...


----------



## Artsi

It seems that ground hum problem concern at least tubes 6DJ8 and 6922. After workday i'm going to figure how to connect pin9 to get rid of this music spoiling noise. Cathode to free pin of my 9pin switch could solve this.

ECC83 or 6N2P-EV does not have any hum. Did not tried at all 6922 electro harmonix with new box before reading 6DJ8 hum from here.

"Grounding" pin9 in 6.3v mode makes impossible to use couple 6.3v heated tubes that have pin9 connected to filament middle. They burn to death i think.


----------



## gibosi

trolldragon said:


> I am going to play "Devils Advocate" as well...
> 
> All this dual triode stuff is really great, *BUT* caution needs to be used in the selection of the tubes used. Rolling most of the 7 pin tubes were no problem, but with the 9 pin tubes you can be exceeding the design specs of the amplifier's transformer. Which is my main concern as I don't want to see any ones amplifier stop working.
> 
> ...


 
  
 This is very good advice, and thanks for bringing this to our attention. 
  
 Fortunately, the 6DJ8 / ECC88 is .365 amps and the 12AX7 / ECC83 is .3amps (in 6 volt operation) , and these are the only double triodes I have considered rolling. But as you note, the universe of double triodes is quite large, and we should be careful to check the amperage of any new tube before we play.
  
 Cheers


----------



## mordy

Hi Gibosi,
  
 I like your idea of using connections that do not need to be soldered to try things out. From the pictures I gather that you are using one 6DJ8 tube for both channels, whereas in the past I always saw two tubes being used.
  
 I have one each of the 6BS8 and 6BQ7 tubes. Can these tubes be used singly without cutting any pins (the same as the 6DJ8)?
  
 I found it difficult to put together the Vector adapter after I took it apart. I assume that you took it apart to wire the adapter. What kind of crimp on pins could I use on the Vector adapter to avoid disassembling it?
  
 Hi Trolldragon,
  
 Would the above mentioned 6V 6BS8 and 6BQ7 tubes with a rating of 0.40 A be safe to use with the Little Dot MKIII?


----------



## Artsi

People here have been using two 7pin 0.45A tubes with no problems. This means 0.9A current from transformer in my calculations. So i think that if we stay under 0.5A with one tube everything is safe.

I have wrote currents to all "compatible" tubes in the list.

I do not suggest to anyone try crazy experiments with 6N6P etc powertubes as driver.


----------



## TrollDragon

mordy said:


> Would the above mentioned 6V 6BZ7 and 6BQ7 tubes with a rating of 0.40 A be safe to use with the Little Dot MKIII?


 
 Hey mordy!
  
 Most if not all of the 0.4A tubes should be fine to use, but I personally would try to get tubes with a lower current requirement. The closer you get to that 0.5A maximum the greater the chance there is for failure and there is really no way to know what the maximum value is on the transformer other than what is printed on the label.
  
 I would look into the 6DJ8 / ECC88 or the 12AX7 / ECC83 running in 6V mode like gibosi uses.
  
 As I stated earlier all the "Recommended" tubes in the manuals are 0.3A's or less and this dual triode modding is really stepping outside of the design parameters of the amp.
  
 So there is no way to really know if a tube is "Safe" or not, even some of the 7 pin tubes we roll are pushing the limit. The 6Ж5П's that I have in right now, have a heater current of 0.45A with a ± 0.025A tolerance, this means the tube might draw 0.425A which would be quite high, or it is drawing 0.475A which is just asking for trouble. My favorite tube the 6AH6WA can draw anywhere from 0.42A to 0.48A and I really should not be using either of these tubes.
  
 Now I have to find a tube that sound as great as these two do but with less current draw, something like a 6CS6 with more bass, that would be really nice...


----------



## MRpilgrim

Hi. I just bought a pair of GE jan 5654 w tubes from nostubestore.com , there is quite an obvious humming noise when the music is not playing. Is this because I did not put the tubes in properly? I'm using the little dot 1+. Thanks


----------



## TrollDragon

mrpilgrim said:


> Hi. I just bought a pair of GE jan 5654 w tubes from nostubestore.com , there is quite an obvious humming noise when the music is not playing. Is this because I did not put the tubes in properly? I'm using the little dot 1+. Thanks


What tubes did you have in before? Did you check your manual for the proper jumper settings for that type of tube?

Dirty pins on the tube not making good contact could be the cause as well.


----------



## MRpilgrim

I was using the stock Chinese 6J1 tubes. Both of then use the same EF95 setting.


----------



## MRpilgrim

them*


----------



## Artsi

Box seems to need one improvement. To get rid of humming with 6DJ8 and 6922 tubes Pin9 needs to be connected to right channel cathode, Pin8. I'll add it via extra switch to free connector of already connected 9pin switch. Left channel cathode did not help at all.


----------



## Audiofanboy

I wouldn't worry too much about heater current on our amps with double triodes. I used pairs of 0.3A+ tubes for months without issues (actually 0.3A heaters the minimum I would consider using for pentodes and single triodes, I often used 0.4 and 0.45A tubes, so a total of 0.9A), so 0.6 to 0.9A total driver heater current. The tubes we're looking at now have pretty petty heaters compared to what we've been using lol!
  
 Interestingly, and despite the high gain of the 12AX7 tube I'm using, I find that the amp runs pretty cool compared to my previous standards. And _that_ can't be a bad thing!
  
 So, I guess we've reached a temporary conclusion on what to do with the shield on 6DJ8 tubes huh? Great, now I can get started on my soldering work.
  
 Btw, I've just added a _large_ amount of tubes of all types to my selling thread; just putting it out here in case someone's interested (there's a pretty large array of choices there lol).
  
 http://www.head-fi.org/t/671097/little-dot-driver-tubes-ef95-ef92-ef91-more
  
 There's also a thread below that one in the classifieds with my last DR supertubes; if anyone wants a "glory package" along with nice driver tubes... I might also have a MK IV SE unit for sale in a few weeks, if someone is looking for an even more glorious package lol. It's not mine, but my father's, who hasn't used it much apart from the preamp section and doesn't see the point of keeping it (so, it doesn't have loose driver sockets like mine does lol).


----------



## gibosi

mordy said:


> Hi Gibosi,
> 
> I like your idea of using connections that do not need to be soldered to try things out. From the pictures I gather that you are using one 6DJ8 tube for both channels, whereas in the past I always saw two tubes being used.
> 
> ...


 
  
 First, as has been noted by others, many of us have been using Tung-Sol 6485 / 6AH6 for quite some time, which draw .45 amps, and I am not aware of any problems. However, given TrollDragon's post, to be on the safe side, I think I will consider .45 amps to be the upper limit for me. And given that so many of us have used our Tung-Sols with no issues, I believe the 6BQ7 (which is the same as 6BS8 and 6BZ7), with .4 amps, should not be a problem. However, I can assure you, the 6DJ8 and 12AX7 will sound much better and have the additional benefit of a lower current draw. So your current tubes are fine to experiment with, but I encourage you to move on to these better tubes in the future.  
  
 And yes, the Vector adapters are a pain to reassemble. I loosened the screw and pulled them apart only a fraction of an inch, just enough to allow me to thread a wire through the eye of the test point tab. I twisted the wire tightly several times, and then, once the adapter was screwed back together, I have a secure mechanical connection. (Sorry that the picture is not the greatest, but I think you can see what I have done.)


----------



## gibosi

artsi said:


> Box seems to need one improvement. To get rid of humming with 6DJ8 and 6922 tubes Pin9 needs to be connected to right channel cathode, Pin8. I'll add it via extra switch to free connector of already connected 9pin switch. Left channel cathode did not help at all.


 
  
 I'm glad you tried the left channel cathode. I didn't think it would work as the ground hum was in the right channel, but it is good to have this confirmation.


----------



## Artsi

gibosi said:


> I'm glad you tried the left channel cathode. I didn't think it would work as the ground hum was in the right channel, but it is good to have this confirmation.


 
 There was little hum with left channel too, but not like right. I've been listenin nearly all the time with 6N2P-EV -76 and i'm very very happy with this cheap one. 6N2P does not hum and i can't notice any difference in sound if my shield-ground-switch is on or off. This was the tube which made me nearly cry and i think it is still getting even better with more on time.
  
 I bought this cheap person from here http://www.ebay.co.uk/itm/130967121083.


----------



## gibosi

artsi said:


> There was little hum with left channel too, but not like right. I've been listenin nearly all the time with 6N2P-EV -76 and i'm very very happy with this cheap one. 6N2P does not hum and i can't notice any difference in sound if my shield-ground-switch is on or off. This was the tube which made me nearly cry and i think it is still getting even better with more on time.
> 
> I bought this cheap person from here http://www.ebay.co.uk/itm/130967121083.


 
  
 I have four of these coming to me, veryyyy slowly, from Tbilisi, Georgia, and I am very glad to know they sound good. 
  
 I found one person who tried them in his Schiit Lyr, and he said they were terrible! lol But I think the LD is much more flexible than the Lyr when it comes to tube rolling....


----------



## mordy

I thank everybody for answering my questions - thanks.
  
 Hi Gibosi,
  
 I am getting in a 9 pin socket with tabs underneath that have holes in them. Using Gibosi's wire wrap method I think I could make a temporary set up without soldering. I have a 12AX7 tube to try.
  
 What I need is simple instructions how to route the wires. The Vector adapters have numbers printed on them. The 9 pin socket can be numbered underneath left to right 1-9, where 1 is starting at the pin gap left.
  
 Something like: Vector left adapter (VL) #2 to Tube (T) #3 or VL2 to T3 and so on. Vector right tube would be VR etc.
  
 Is the wiring for 12AX7 different than the wiring for 6DJ8?


----------



## gibosi

mordy said:


> I thank everybody for answering my questions - thanks.
> 
> Hi Gibosi,
> 
> ...


 
  
 I have yet to get a 12AX7 so I haven't really sat down to work it out exactly. However, the only difference in how we connect the 6DJ8 and the 12AX7 is the way the heaters, tube pins 4, 5 and 9 are connected.  But this will get you started.  And if someone else can tell us how to connect the heaters, that would be great.
  
 9-pin socket           left LD socket        right LD socket
  
 1 plate triode 1                5                        
 2 grid triode 1                  1
 3 cathode triode 1            2
 4 heater                          ?                         ?
 5 heater                          ?                         ?
 6 plate triode 2                                           5
 7 grid triode 2                                             1
 8 cathode triode 2                                       2
 9                                    ?                         ?


----------



## Audiofanboy

gibosi said:


> I have yet to get a 12AX7 so I haven't really sat down to work it out exactly. However, the only difference in how we connect the 6DJ8 and the 12AX7 is the way the heaters, tube pins 4, 5 and 9 are connected.  But this will get you started.  And if someone else can tell us how to connect the heaters, that would be great.
> 
> 9-pin socket           left LD socket        right LD socket
> 
> ...


 
  
 Easy!
  
 Just connect pins 4+5 to one the B7G socket heater pins (let's say pin 3 for instance) and connect pin 9 to the other B7G heater pin on the same socket (so pin 4 in this case). And, _voila_, you get paralleled 6V-fed heaters instead of the typical 12V in series (heaters work the same in both scenarios).
  
 That's also the good thing about the 12Ax7 types is that nothing forbids us from only using one heater (pin 4 or 5, depending on triode to heat, would be routed to B7G pin 3, and pin 9 would still go to B7G pin 4), and leaving the other hanging _without_ eventual cathode poisoning.
  
 Like I said: easy! (and no possible shield issues, like on 6DJ8 tubes...)


----------



## gibosi

gibosi said:


> 12AX7
> 
> 9-pin socket           left LD socket        right LD socket
> 
> ...


 
  
 Updated to per AFB.


----------



## gibosi

gibosi said:


>


 
  
 Just an update. With all these wires flying around, this arrangement is rather susceptible to picking up RF noise. Fortunately, moving it a few inches often helps, and after all, since this is a prototype, it is very acceptable until I can build a proper adapter box.
  
 Also, I am happy to report that I was able to straighten the bent pins on one of my Bugleboys and it works fine.... Life is good.


----------



## MIKELAP

gibosi said:


> Just an update. With all these wires flying around, this arrangement is rather susceptible to picking up RF noise. Fortunately, moving it a few inches often helps, and after all, since this is a prototype, it is very acceptable until I can build a proper adapter box.
> 
> Also, I am happy to report that I was able to straighten the bent pins on one of my Bugleboys and it works fine.... Life is good.


 
 Ordered some  Bugleboys now just waiting to see the hum issue resolved so the end product is 100% ,also dont really want to cut or bend pins on those i rather use¨THE BOX¨ if safe.


----------



## Oskari

gibosi said:


> Just an update. With all these wires flying around, this arrangement is rather susceptible to picking up RF noise.


 
  
 Perhaps it should be noted that the ECC88/6DJ8 is prone to parasitic oscillation. You might want to read up on that.


----------



## gibosi

oskari said:


> Perhaps it should be noted that the ECC88/6DJ8 is prone to parasitic oscillation. You might want to read up on that.


 
  
 Searching Google does indeed confirm this . However, I did not have this problem when I was cramming two 6DJ8s into 7-pin sockets. So I have to believe that what I am hearing is due to having all these wires out in the open, picking up ambient RF.
  
 The only possible indication of parasitic oscillation I experience is when I turn the volume to zero, there is a ground hum. Therefore, I don't turn the volume lower than 1, and all is fine.


----------



## gibosi

mikelap said:


> Ordered some  Bugleboys now just waiting to see the hum issue resolved so the end product is 100% ,also dont really want to cut or bend pins on those i rather use¨THE BOX¨ if safe.


 
  
 If pin-9 is tied to pin-8, the ground hum problem is absolutely resolved.


----------



## hypnos1

audiofanboy said:


> I wouldn't worry too much about heater current on our amps with double triodes. I used pairs of 0.3A+ tubes for months without issues (actually 0.3A heaters the minimum I would consider using for pentodes and single triodes, I often used 0.4 and 0.45A tubes, so a total of 0.9A), so 0.6 to 0.9A total driver heater current. The tubes we're looking at now have pretty petty heaters compared to what we've been using lol!
> 
> Interestingly, and despite the high gain of the 12AX7 tube I'm using, I find that the amp runs pretty cool compared to my previous standards. And _that_ can't be a bad thing!
> 
> ...


 
  
 Hi AFB and anyone else listening...
  
 Re filament/heater current draw, all was OK using 1 triode per channel, but if we want to use both per channel (ECC88 mode) are we going to be in trouble? If it CAN be done safely, as I am
 so ignorant in electronic circuitry, I would be most grateful for advice re pin wiring...
  
 Cheers!


----------



## gibosi

I received a small package today and now I am in heaven.
  
 6922 / E88CC made by Amperex in the US.
  
 After spending a few hours with this tube, it has jumped to the top of the pile (of some 400 tubes!).   But even though I think I am in heaven, I still think I should try some 12AX7. So this morning I purchased a Tung-Sol JTL 5751. The 5751 is a premium version of the 12AX7. However, the mu (gain) was lowered to 70 and the current was raised to .350 amps, compared to a mu of 100 and .300 amps for the 12AX7. Supposedly this was done to extend the lifetime and reduce microphonics and noise.
  
 But for now, it's time for me to turn the volume up and go back to heaven....


----------



## Nic Rhodes

5751 is really a little different from the ECC83 though there are certainly many / some simularities. I have an amp that uses 5751 that doesn't use ecc83. It also uses separate E182CC and 5687 that many often consider similar also. 5751 are cetainly a good tubes (try RCA commands, Syvania Gold Brand and GE 5* also) to look at further when correctly used / biased.
  
 The Amperex US E88CC (6922) are certainly excellent tubes. Do look at the European 6922 however which I feel are better again, as are CCa, CV2493, E88CC-01s. However even the basic Mullard / Amperex EC88 / 6DJ8 from europe are excellent and often over looked. It is funny we started off with the cheapest Russian 6J5Ps and have made our way to Amperex 6922s! Don't you just love the LDs.


----------



## gibosi

nic rhodes said:


> 5751 is really a little different from the ECC83 though there are certainly many / some simularities. I have an amp that uses 5751 that doesn't use ecc83. It also uses separate E182CC and 5687 that many often consider similar also. 5751 are cetainly a good tubes (try RCA commands, Syvania Gold Brand and GE 5* also) to look at further when correctly used / biased.
> 
> The Amperex US E88CC (6922) are certainly excellent tubes. Do look at the European 6922 however which I feel are better again, as are CCa, CV2493, E88CC-01s. However even the basic Mullard / Amperex EC88 / 6DJ8 from europe are excellent and often over looked. It is funny we started off with the cheapest Russian 6J5Ps and have made our way to Amperex 6922s! Don't you just love the LDs.


 
  
 Thanks for your comments. I do in fact have my eye on a GE 5751. And while I would really like to get a Sylvania Gold Brand, the prices I am seeing are way too steep for me.
  
 And I agree completely regarding basic ECC88 / 6DJ8. As a "bottom feeder", I managed to obtain Mullard, Amperex (BugleBoy, A-frame Orange Globe and red-label), Siemens (both ECC88 and PCC88), Reflector 6N23p, Tesla PCC88, and GE 6DJ8. Even though for the most part, these were all "well used" tubes, and cheap, I figured that they still have at least 100 hours life left in them, which would be enough for me to get a handle on their sound. And for sure, all of these are excellent tubes. However, in the end, the Amperex BugleBoy is the one I kept in my amp.
  
 So it seemed logical to assume that I should probably seek out an Amperex 6922, either Holland or US made. Ultimately, my final decision was dictated by price. I was able to get these Amperex US tubes at a great price, and I grabbed them.
  
 And of course, I will keep an eye out for great buys on other European 6922, CCa, CV2493, E88CC-01s. With patience, I am really hoping that I can find a great buy on a German-made premium Telefunken, Siemens or Valvo. But these tend to be very pricey, so I am prepared for a long wait.....


----------



## Nic Rhodes

Patience always delivers, I have bought 4 Siemens NOS boxed CCa recently for £50 each ($80US), Although not 'cheap' it is a fraction of what many CCa can  go for. Even better bargains to be had on CV2492 / CV2493 and E88CC-01s to be had which are often mislabeled or not recognised for what they really are. If you don't mind used tubes, then the saving escalate on these tubes which can have some really long lifetimes (10,000+ hrs on th some european ones are common enough). Also look at the 7 range (7DG8) with a slightly different heater. They warm up slower but should work fine here and are much cheaper! [7v as opposed to 6.3v]. There are also another class of tubes which are interesting which are the wire ended double triodes. These are easily soldered to 2 vector 7pin socket saver making conversions easier.
  
 CV4069 premium 13D3
 CV4033 premium 12AT7 / ECC81 [CV4024 with wire leads as opposed to pins]
 CV4034 premium 12AU7 / ECC82 [CV4003 ditto]
 CV4035 premium 12AX7 / ECC83 [CV4004 ditto]
 CV4109 premium 7308 (6DJ8 / ECC88 like if you don't know it but up a level)...
  
 these used to go for peanuts but certainly the latter now are more sought after.


----------



## Audiofanboy

Got my Telefunken 12AX7/ECC83 with ribbed plates in the mail this morning.
  
 Expensive but a pretty good pick, considering. Pretty much full logo and silk writing (infamous for wiping off real easily) and even the small date codes (uc: 11-1959).
  
 As they were supposed to, these are used but obviously super strong tubes. They give about the most gain I've ever had in my amp (lowest necessary volume levels, actually).
  
 Critically speaking, I can't say, both from the first listen and after two hours of listening, that these are perfect tubes. I'm starting to understand what people mean by 6DJ8 tubes being "superior" to 12Ax7 types all things considered. These Tele tubes are awesome but not god tier, despite being pretty close to the best you can find in the 12Ax7 families.
  
 Still, I'm not trying to make it sound like they're bad, it's quite the opposite in fact; I'm just giving truthful impressions in all absolutes. Like I said, these are great! People say they're "thin and airy". While I get the airy part, these are definitely _not_ thin; if anything they have a pretty thick and creamy (not warm) midrange and tight deeeeep controlled bass (the most infra I've ever heard on my amp, and that's saying a lot). Highs are definitely well extended (the Tele reputation), without a hint of sibilance or piercing pain like some people say. These tubes do "come on strong" depending on the types of music you're listening to though. Since they're very balanced and extended, the music can kind of spill all of its guts at you in ways you're not used to.
  
 They have this odd sense of deep detail and control, but at the sense time they make you feel like you're not hearing the last word in resolution or focus. It's weird, you hear everything but it all sounds so breezy and soft that you don't _think_ you're hearing the absolute maximum of details, but you actually are... You'd have to try it to get what I mean.
  
 Compared to my EI 12AX7 with Tele smooth -later- plates, the genuine ribbed Tele have more energy and extention. The EI are warmer and more "harmonically rich" like the guitar crowd says, probably a bit less detailed, though like I said the details on the ribbed Tele don'tt sound like details, whereas details on the EI sound like you're getting pretty good resolution and focus. I know, I'm explaining this poorly...
  
 Anyway, very nice tubes the ribbed Tele are, but I'm still quite fond of my smooth plate EI. I'll give my final comments when I get a chance to AB both directly. Unless I get my Orange Globes first, _obviously _lol.


----------



## Artsi

I got today 3 different 6DJ8 tubes. Westinghouse made in USA -63, Amperex made in Holland -74 and Voskhod 6N23P -84 with rocket logo. All of these need pin 8-9 connection to get rid of hum. I found little praise to 6N23P from internet: http://app.audiogon.com/listings/tubes-nos-voskhod-rocket-logo-6n23p-6h23n-giant-killers-only-35-a-pair-2013-05-16-accessories-32828 I do not have CCa:s to compare and not going to get one, i have some different plans...


----------



## gibosi

I am getting ready to build adapter boxes for the double triodes. My thinking is to build two boxes, one for 6-volt tubes, and a second one for the 12-volt tubes. In this way I can keep it simple and eliminate the switch.
  
 So.... I have a few questions for those of you who have more experience with projects such as these. First, I need to buy a 9-pin socket. It appears that there are two types, one for circuit board mounting and one for chassis mounting, so obviously, I need to buy the latter. But I do not know how to securely mount these sockets onto the box in such a way that they can sustain the considerable stress of inserting and removing tubes. Some have mounting flanges to allow the socket to be secured with screws, but I don't know I can use screws with a plastic box. Looking closely at Artsi's box, I don't see any screw heads, so I do not how know his socket is mounted.
  
 Also, I notice that there are gold plated sockets. But I am wondering if it is harder to solder wires to gold-plated metal?
  
 And what kind of connecting wire would be best? Solid core? Stranded? Gauge?
  
 Thanks!


----------



## gibosi

artsi said:


> ...............I found little praise to 6N23P from internet: http://app.audiogon.com/listings/tubes-nos-voskhod-rocket-logo-6n23p-6h23n-giant-killers-only-35-a-pair-2013-05-16-accessories-32828 I do not have CCa:s to compare and not going to get one, i have some different plans...


 
  
 According to this reviewer, Voskhod 6N23P manufactured from 1974 through 1980 are quite good:
  
 http://www.head-fi.org/t/549508/schiit-lyr-the-tube-rolling-thread/8595#post_9625620


----------



## Artsi

Plastic box is pretty hard. I glued socket with epoxy to it. Used about 20 gauge stranded wire. Don't know what is best.


----------



## Nic Rhodes

gibosi said:


> According to this reviewer, Voskhod 6N23P manufactured from 1974 through 1980 are quite good:
> 
> http://www.head-fi.org/t/549508/schiit-lyr-the-tube-rolling-thread/8595#post_9625620




I would second that, adding the older the better generally. Plus there are two styles in this era. I am sure I have some 1972s however.

Edit post says much the same outside 1972 bit!


----------



## MIKELAP

gibosi said:


> I am getting ready to build adapter boxes for the double triodes. My thinking is to build two boxes, one for 6-volt tubes, and a second one for the 12-volt tubes. In this way I can keep it simple and eliminate the switch.
> 
> So.... I have a few questions for those of you who have more experience with projects such as these. First, I need to buy a 9-pin socket. It appears that there are two types, one for circuit board mounting and one for chassis mounting, so obviously, I need to buy the latter. But I do not know how to securely mount these sockets onto the box in such a way that they can sustain the considerable stress of inserting and removing tubes. Some have mounting flanges to allow the socket to be secured with screws, but I don't know I can use screws with a plastic box. Looking closely at Artsi's box, I don't see any screw heads, so I do not how know his socket is mounted.
> 
> ...


 
 Was thinking also about how to mount that 9 pin socket so it doesnt come off eventually i would go with the chassis mounting socket .i would drill 2 hole for the flange insert 2 screws and and tighten the 2 nuts the only thing i dont know since i dont have the sockets yet is if you can put the flange outside or inside the box if inside looks better thighten nuts and it would be really  sturdy only thing you would see outside is   the heads of the 2 screws and washers to make it stronger so cover doesnt crack because cover is only .079 thousands of an inch  thick which is about 5/64 (.075) so reinforcement would help imo.                                                                                                                                                                                                                                                                                Heres a picture .  Could put socket outside  by drilling dia  #1  after  drill holes  put screws in flange holes with nut underside with little lock washers on underside of cover  and it should not move .Or if you would put flange inside  box cover try to make hole size close as possible to #2 diametre  drill holes for flange  maybe try and find a big enough washer that would go around hole on top of cover so it looks nicer like rings around tube holes on mk3 as long as tube clears washers inside diametre


----------



## gibosi

mikelap said:


> Was thinking also about how to mount that 9 pin socket so it doesnt come off eventually i would go with the chassis mounting socket .i would drill 2 hole for the flange insert 2 screws and and tighten the 2 nuts the only thing i dont know since i dont have the sockets yet is if you can put the flange outside or inside the box if inside looks better thighten nuts and it would be really  sturdy only thing you would see outside is   the heads of the 2 screws and washers to make it stronger so cover doesnt crack because cover is only .079 thousands of an inch  thick which is about 5/64 (.075) so reinforcement would help imo.


 
  
 What do you think about using something like this?
  





  
 http://www.ebay.com/itm/280813678242?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649


----------



## gibosi

And it appears that this socket is designed to be mounted from inside the box:


----------



## MIKELAP

gibosi said:


> And it appears that this socket is designed to be mounted from inside the box:


 
  


gibosi said:


> What do you think about using something like this?
> 
> 
> 
> ...


 
 I gather socket goes in middle you got your holes for flange . The plate is about 2/12 inches long . 1591msbk box dimensions are 3.339" L x 2.205" W X1.023H looks like the plate is a bit to big correct me if i am wrong .Looks like socket is mounted like you say from inside the box the problem is making a nice hole if you dont have exact drill size i would trace the  hole size you need on the cover using a steel compass so as to outline the hole size so if you finish by hand you have a reference.


----------



## gibosi

mikelap said:


> I gather socket goes in middle you got your holes for flange . The plate is about 2/12 inches long . 1591msbk box dimensions are 3.339" L x 2.205" W X1.023H looks like the plate is a bit to big correct me if i am wrong .Looks like socket is mounted like you say from inside the box the problem is making a nice hole if you dont have exact drill size i would trace the  hole size you need on the cover using a steel compass so as to outline the hole size so if you finish by hand you have a reference.


 
  
 I didn't even think to check the dimensions of the box and plate! It's a good thing I haven't ordered it yet! lol
  
 So.....   it seems that I am going to get a lot of practice trying to cut nice round holes in plastic...... Maybe I should get one of these:
  
 http://www.roguehydro.com/unibit-10-step-drill-bit-1-4-1-3-8-inches/?ref=lexity&_vs=google&_vm=productsearch&adtype=pla&gclid=COeIwIOyo7oCFQ2g4Aod-W0AHw


----------



## MIKELAP

gibosi said:


> I didn't even think to check the dimensions of the box and plate! It's a good thing I haven't ordered it yet! lol
> 
> So.....   it seems that I am going to get a lot of practice trying to cut nice round holes in plastic...... Maybe I should get one of these:
> 
> http://www.roguehydro.com/unibit-10-step-drill-bit-1-4-1-3-8-inches/?ref=lexity&_vs=google&_vm=productsearch&adtype=pla&gclid=COeIwIOyo7oCFQ2g4Aod-W0AHw


 
 I have one of those bits you can start with that we will all see the size needed when we get the parts but if size is not exact outline circle to be able to finish maybe with a dremel or small file because cover is thin so possible to make a nice round hole                                                                                                                                                                                                                                                                                                                                                                                       Also i was looking for copper pin material for 7 pin socket and i found some with the wright size (18 gauge) in an old coax cable i had lying around so happy with that so now just have to straighten it 
 found this to straighten wire fast .               http://youtu.be/2gwGBvp3Drc


----------



## mordy

I am trying to find a way to use my 12AX7 tube, but so far I have failed miserably. I am not that handy, and working with the tiny parts on the Vector 7 pin adapter is very difficult for me - I even broke one adapter when I tightened up the solderless wirewrap leads with the screw in the middle. The little nut on the bottom rests in a well, and part of the bakelite broke off, so I cannot tighten the adapter any more.
  
 I found a Chinese source for breadboards and socket adapters, and even for pins to make you own adapter using the Mullard socket protectors.
  
 http://www.ebay.com/itm/100pc-gold-plated-tube-pin-for-you-DIY-Tube-adapter-15-1mm-free-shipping-/200977094414?
  
 This guy seems to be much cheaper than the other source for adapters mentioned previously on this site.
  
 Maybe somebody on this forum could describe to this seller what we want and how to wire a one piece adapter for the Little Dot amps. If an inexpensive one piece adapter was available, I would not be left out from sampling the new sonic delights.....


----------



## MIKELAP

If you want to finish your 9 pin adaptor hole  you can get nice rings here  theres also silver i think               http://www.ebay.com/itm/2-Champagne-Gold-Machined-Aluminum-12AX7-Tube-PreAmplifier-Decorating-Base-Ring-/321137978846?pt=US_Amplifier_Parts_Components&hash=item4ac550adde


----------



## TrollDragon

I'm going to run something like this when I pick up a B9A socket and a few tubes.

 https://db.tt/ZK73zNzB 

Sorry for the phone picture and you can't upload photos from the mobile browser version of HF.


----------



## MIKELAP

trolldragon said:


> I'm going to run something like this when I pick up a B9A socket and a few tubes.
> 
> https://db.tt/ZK73zNzB
> 
> Sorry for the phone picture and you can't upload photos from the mobile browser version of HF.


 
 Now thats original !


----------



## TrollDragon

Thank you sir!
I do love me some copper...


----------



## MIKELAP

trolldragon said:


> Thank you sir!
> I do love me some copper...


 
 I noticed your headphone stand also very original. just curious you dont know if sockets will fit in right because whats the chance of them fitting perfectly unless you make bushings for them what kind of glue would bond ceramic and copper. to bad dont have parts readily available to fiddle with and to bad dont have a lathe!


----------



## bundy

Hi to the world of little dot tube rolling i am new & loving it totally. My music has come to life with the tube sound. Now my problem is i have a Little dot 1+ which arrived with Chinese 6J1 tubes, I swapped them out for a matched set of E95F 5654 tubes i have now ordered a matched set of Voshkod 6J1P-EV These are supposed to have grooved tubes & are supposed to be the best EF95 types. As a complete novice to this tube rolling & i don't know wot i am doing so is there anyone please that can tell me if they are correct & ok to use in my Little Dot1+. Big thanks to all who asked, my spine surgery went well & i am home again now it's a long road to heal.
 bundy


----------



## gibosi

bundy said:


> Hi to the world of little dot tube rolling i am new & loving it totally. My music has come to life with the tube sound. Now my problem is i have a Little dot 1+ which arrived with Chinese 6J1 tubes, I swapped them out for a matched set of E95F 5654 tubes i have now ordered a matched set of Voshkod 6J1P-EV These are supposed to have grooved tubes & are supposed to be the best EF95 types. As a complete novice to this tube rolling & i don't know wot i am doing so is there anyone please that can tell me if they are correct & ok to use in my Little Dot1+. Big thanks to all who asked, my spine surgery went well & i am home again now it's a long road to heal.
> bundy


 
  
 Good to hear that you are on the mend! Yes, indeed, the Voskhod 6J1P-EV are perfectly safe to use in your LD. Enjoy!


----------



## gibosi

Yesterday, I received a Tung-Sol 5751, dated 1960. Again, this is a premium version of the 12AX7.
  

  
 However, it will be a while before I roll this tube, as I have just replaced my no-name Chinese DAC with the Audio-gd Fun. With two major changes, this DAC and the US Amperex 6922 / E88CC, I need some time to recalibrate my ears. I can say, that with these two changes, the sound I am getting from my little LD 1+ is pretty amazing. 
  
 Oh, the white box? I finally found a good use for a sleeve of 6AG5s lol. It provides a little isolation between the tube socket and the LD transformer.


----------



## gibosi

mordy said:


> I am trying to find a way to use my 12AX7 tube, but so far I have failed miserably. I am not that handy, and working with the tiny parts on the Vector 7 pin adapter is very difficult for me - I even broke one adapter when I tightened up the solderless wirewrap leads with the screw in the middle. The little nut on the bottom rests in a well, and part of the bakelite broke off, so I cannot tighten the adapter any more.
> 
> I found a Chinese source for breadboards and socket adapters, and even for pins to make you own adapter using the Mullard socket protectors.
> 
> ...


 
  
 You might want to contact this vendor and refer him to Artsi's tutorial:
  
 http://www.head-fi.org/t/686893/how-to-make-an-adapter-to-use-double-triode-tubes-with-little-dot-mk-i-iv
  
 And ask if they could make something like this.


----------



## TrollDragon

mikelap said:


> I noticed your headphone stand also very original. just curious you dont know if sockets will fit in right because whats the chance of them fitting perfectly unless you make bushings for them
> what kind of glue would bond ceramic and copper. to bad dont have parts readily available to fiddle with and to bad dont have a lathe!


 
 Thanks I have two headphone stands made from copper.
  
 Then you need to pick up a Grizzly 7X12, like all Chinese machinery there is a little bit of slop in them, but you can use the lathe to make the parts to need to tighen up the specs. BusyBee has a similar one since they mostly all come from the same factory.
http://www.grizzly.com/products/7-x-12-Mini-Metal-Lathe/G8688 
 or 
http://www.busybeetools.com/products/LATHE-METAL-MINI-7IN.-X12IN.-CRAFTEX-CX-CSA.html
  
 Here is a nice site all about the mini lathes.
http://www.mini-lathe.com/Mini_lathe/Setup/setup.htm
  
 The 9 pin socket might just fit easily depending on which one you get, some do have a Ø 22mm and the fitting has a Ø 0.875". If not a little flaring would be in order. 
	

	
	
		
		

		
			




 JB Weld or PC-7 will bond just about anything to anything, JB Weld can be machined after it hardens as well as drilled and tapped. But if you pick up the JB Weld Kwik you have a 1 minute mix and a 5 minute work time, so have everything ready to be locked down.
  
 I am going to cut out a disk of thick plexiglas to put the copper coax cable made pins (Nice find!) in for the 7 pin sockets and cement the disk to the bottom of the 1/2 pipe pieces. I have some fine carbide pcb drills to make holes in the plexiglass for the pins.
  
 Now to get the socket and a few tubes.


----------



## gibosi

trolldragon said:


> I'm going to run something like this when I pick up a B9A socket and a few tubes.
> 
> https://db.tt/ZK73zNzB
> 
> Sorry for the phone picture and you can't upload photos from the mobile browser version of HF.


 
  
 I'd really like that! Will you make me one too? lol


----------



## MIKELAP

trolldragon said:


> Thanks I have two headphone stands made from copper.
> 
> Then you need to pick up a Grizzly 7X12, like all Chinese machinery there is a little bit of slop in them, but you can use the lathe to make the parts to need to tighen up the specs. BusyBee has a similar one since they mostly all come from the same factory.
> http://www.grizzly.com/products/7-x-12-Mini-Metal-Lathe/G8688
> ...


 
 Man showing me a mini lathe your getting me all wound up here a lot of $$$$$ i would need to do lots of jobs to pay that off .                                                                                                                                                                                                                                                                                      It seems theres a +or - .009 thousands tolerance it could possibly fit right off the bat .Will you take a pin saver to mark holes for drilling  and do you have a drill press i guess youll use use top speed so it drills straight maybe tapping fluid or oil so shaving dont bugger up the drill and jams in the hole its damm small .                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             Well im off to my friendly neighborhood plumbing supply store got some fiddlin to do.ill bring a 7 pin socket mine the smaller dia is 5/8 inch and a 7 pin saver i have   is 5/8 also .


----------



## TrollDragon

mikelap said:


> Man showing me a mini lathe your getting me all wound up here a lot of $$$$$ i would need to do lots of jobs to pay that off .                                                                                                                                                                                                                                                                                      It seems theres a +or - .009 thousands tolerance it could possibly fit right off the bat .Will you take a pin saver to mark holes for drilling  and do you have a drill press i guess youll use use top speed so it drills straight maybe tapping fluid or oil so shaving dont bugger up the drill and jams in the hole its damm small .                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             Well im off to my friendly neighborhood plumbing supply store got some fiddlin to do.ill bring a 7 pin socket mine the smaller dia is 5/8 inch and a 7 pin saver i have   is 5/8 also .


 
 We just had a customer in who builds the model trains that you can ride on, something like this one here.
  


Spoiler: Non Tube related image... :D






  
 He has an Atlas and a Southbend at home which he uses, he also recommends one with at least a 3' bed as they are made a little better and there is always something you will want to make that wont fit on the 12" version.
  
 I bet once people know you have a lathe in the area it will be a non stop "Make me this & Make me that"... It will pay for itself very quickly, all you have to do is convince the wife!


----------



## TrollDragon

gibosi said:


> I'd really like that! Will you make me one too? lol


 
 Let me get mine running first!


----------



## mojorisin35

gibosi said:


> I'd really like that! Will you make me one too? lol


 

 WOW that is awesome! put me down for one as well.
 Gary


----------



## gibosi

trolldragon said:


> I bet once people know you have a lathe in the area it will be a non stop "Make me this & Make me that"... It will pay for itself very quickly, all you have to do is convince the wife!


 
  
 Perhaps we are witnessing the beginning of a new company? * *
  
*T & M Enterprises -- Custom Steampunk Tube Adapters for the Little Dot*      lol


----------



## TrollDragon

gibosi said:


> Perhaps we are witnessing the beginning of a new company? * *
> 
> *T & M Enterprises -- Custom Steampunk Tube Adapters for the Little Dot*      lol


 
 Yes indeed, we will have to see what MIKELAP returns with from the plumbing store.


----------



## mordy

Put me down for one as well. Can it be painted in these colors?
  

  
 Just kidding about the paint, but I wanted to show this beautiful picture taken this week.  I really do want such an adapter.


----------



## TrollDragon

mordy said:


> Put me down for one as well. Can it be painted in these colors?
> 
> 
> 
> Just kidding about the paint, but I wanted to show this beautiful picture taken this week.  I really do want such an adapter.


 
  
 When I get mine all assembled and working I'll let everyone know for sure!
 Now if you wanted Realtree or Mossy Oak...
  
  
 You really would not want to cover the beautiful luster of a nicely polished and lacquered piece of copper.


----------



## jaywillin

well, after a brief absence , full of sellers regret having sold my little dot I+, i bought another, new, just had it 3 days,
 i'm not going to let this one go
 i splurged and spent some money, on some telefunken eh900s, gold pins, matched pair, AWESOME sound


----------



## MIKELAP

trolldragon said:


> Yes indeed, we will have to see what MIKELAP returns with from the plumbing store.


 
 Well im back and busy i have a bit of a different take on it than Troll Dragon but basically it is his same great original design there is 3 copper pipes the one that holds the 9pin is not modified and goes in the other part. I dont have a socket yet so i could be screwed from the start but socket will be definitely smaller than .Hole in pipe is 7/8¨ but like they say if theres a will theres a way.                                                                                                                                                                                                                                                                                                                                                                                            The changes are for the center part where the right side elboy goes ii had  to remove about 3/8 inches on the lenght so elboy goes in far enough inside the tube to line up with littledot socket but  i had to grind the inside of the hole so elboy can go inside  more to get the wright center distance so that you can plug the 2 sockets in but you have to grind or make shure elboy is loose so that you can move it inside and out to be able to plug it in the Littledot so like that you dont have to get center perfect which would be very hard with basic tools.And by the way once elboy is in it does not block the other hole for the left channel.because got to think of wires .                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           So thats for the chassis now i have to see what sockets i am going to use because i have a 7pin female socket that fits perfectly in the hole maybe i could use a socket saver put pins thru that and into socket and glue the socket saver to other socket but i guess i need teflon instead of ceramic dont know if it would hold . So thats it for now have to figure out the sockets.i need .Heres a few pictures .And thank you Troll Dragon for the design.


----------



## TrollDragon

You are most welcome MIKELAP!

I like your design!

I had to go vertical because of the tube rings, I could have taken them off but didn't want to. If you don't want to solder the pipe use one of the epoxy from my other post, they will bond anything.


----------



## gibosi

gibosi said:


> Yesterday, I received a Tung-Sol 5751, dated 1960. Again, this is a premium version of the 12AX7.
> 
> 
> 
> However, it will be a while before I roll this tube, as I have just replaced my no-name Chinese DAC with the Audio-gd Fun. With two major changes, this DAC and the US Amperex 6922 / E88CC, I need some time to recalibrate my ears......


 
  
 A quick update... I decided to roll them in for a few minutes to be sure that I understood how to change the connections from 6DJ8 to 12AX7. And I also wanted to leave feedback for the eBay seller, and felt I should make sure they were working first.
  
 So I listened to only a few songs. However, I can say that these are excellent tubes. There's nothing not to like. So if you can find one of these at a good price, I recommend you grab it.


----------



## MIKELAP

trolldragon said:


> You are most welcome MIKELAP!
> 
> I like your design!
> 
> I had to go vertical because of the tube rings, I could have taken them off but didn't want to. If you don't want to solder the pipe use one of the epoxy from my other post, they will bond anything.


 
 I ust ordered the 7and 9 pin sockets the 7 pin socket fits nicely in the hole not tight but alot better then i expected as for the 9 pin socket its about 1/32 smaller then the 7/8 dia. tubing not bad also . Maybe will do 7 pin sockets like on picture glue
ing pin saver to socket so its hopefully sturdier.And today got my Westinhouse 6BQ7A tubes good thing i bought 20 i broke 2 of them after i cut the pins off i used my Dremel to remove the balance of the pins and i guess vibration broke them from now on its going to be the good old file. Very nice sounding 3d like  for $3.00 each will be even better when i dont have to butcher them anymore .


----------



## TrollDragon

Well when there are no tubes to roll or sockets to play with one just mounts some opamps...
 (2 LME49720-HA Duals Can version & 2 AD8610ARMZ Singles)
  
 The pin in the center is a trial tube socket pin made from a big paperclip section. The end was bent over into a loop, a piece of wire soldered to it and shrink tube applied. The pin is a good gauge size, I will measure it tomorrow and it does not bend very easily.


----------



## Audiofanboy

Nice work on that plumbing people! Our new flagship amplifier, with modified driver tubes and as much random copper parts as possible: the Little Punk MK I !
  
 Alright, so I know you've all just started working on 9 pin adapters, and that most of us have yet to even buy or test more than one or two double triodes, but I can help it, I already have a _new _idea that I'd like to try out. Hint, the idea has an octal base...
  
 Yup, we should try and adapt a 6SL7 type tube in our amps (or 6SN7 but why not go with the higher gain tube?) !
  
 There are many reports that 6SL7 tubes can work perfectly fine in 12AX7 based circuits (all the resistor values are close enough to bias the tubes at least adequately), and seeing how 12Ax7 tubes work flawlessly in our LDs (where the 6AK5-based circuitry is very close to what it should have been for 12Ax7 tubes), I see no reason why we shouldn't try it -even if it turns out to be just for kicks. And besides, those 6SL7 tubes look pretty hardcore, and would look great on a Little Punk MK II unit (MK I is already taken...).
  
 Anyway, just food for thoughts, as usual, while I patiently have to wait for my Amperex tube to get over the Atlantic...


----------



## Artsi

audiofanboy said:


> Alright, so I know you've all just started working on 9 pin adapters, and that most of us have yet to even buy or test more than one or two double triodes, but I can help it, I already have a _new _idea that I'd like to try out. Hint, the idea has an octal base...
> 
> Yup, we should try and adapt a 6SL7 type tube in our amps (or 6SN7 but why not go with the higher gain tube?) !
> 
> ...


 
  
 Can't keep this secret anymore. I ordered octal base and tube couple of days ago. 
	

	
	
		
		

		
		
	


	




 Here is one picture that shows size difference between 6SL7 and 12AT7 tubes. (photo from ebay)

 Powertubes are going to grow bigger too with my next adapter and their sockets are not octals... Is this going to be the end of my lil dot mk2.


----------



## gibosi

audiofanboy said:


> There are many reports that 6SL7 tubes can work perfectly fine in 12AX7 based circuits (all the resistor values are close enough to bias the tubes at least adequately), and seeing how 12Ax7 tubes work flawlessly in our LDs (where the 6AK5-based circuitry is very close to what it should have been for 12Ax7 tubes), I see no reason why we shouldn't try it -even if it turns out to be just for kicks. And besides, those 6SL7 tubes look pretty hardcore, and would look great on a Little Punk MK II unit (MK I is already taken...).


 
  
 And to those of you who are just now beginning to use 6DJ8 and 12AX7 tubes, do not despair! There are cheap 6SL7 to 12AX7 adapters, so it should be easy to use these tubes. 
  
 http://www.ebay.com/itm/281031554093?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649


----------



## bundy

I have a question i live in New Zealand where tubes are not to hard to find but op amps is a different story . I have found one but i am unsure if it will suit it is LMC6482AIN does anyone know if this 1 will work & will it be an improvement  on my sound.Thank You all Bundy


----------



## gibosi

bundy said:


> I have a question i live in New Zealand where tubes are not to hard to find but op amps is a different story . I have found one but i am unsure if it will suit it is LMC6482AIN does anyone know if this 1 will work & will it be an improvement  on my sound.Thank You all Bundy


 
  
 I have no experience with this op amp, so....
  
 Looking at TI's page on this chip, I see nothing regarding its use in audio applications, so that is something to consider....
  
 http://www.ti.com/product/lmc6482
  
 You might want to post your question in the op amp thread as you will likely get a more informed answer there:
  
 http://www.head-fi.org/t/432749/the-opamp-thread


----------



## Edgard Varese

bundy said:


> I have a question i live in New Zealand where tubes are not to hard to find but op amps is a different story . I have found one but i am unsure if it will suit it is LMC6482AIN does anyone know if this 1 will work & will it be an improvement  on my sound.Thank You all Bundy


 
 Texas Instruments shipped me a pair of OPA2107 op amps - for free - and I'm in Christchurch.  All you need to do is register on their site and request a sample.


----------



## jaywillin

edgard varese said:


> Texas Instruments shipped me a pair of OPA2107 op amps - for free - and I'm in Christchurch.  All you need to do is register on their site and request a sample.


 

 and i was just wondering what was the op amp of choice !


----------



## Edgard Varese

jaywillin said:


> and i was just wondering what was the op amp of choice !


 
  
 They ship from Houston so you'd likely have yours in a day or so.


----------



## jaywillin

edgard varese said:


> They ship from Houston so you'd likely have yours in a day or so.


 

 i've never done an opamp swap, do you need the little puller thing, or what ??


----------



## gibosi

jaywillin said:


> i've never done an opamp swap, do you need the little puller thing, or what ??


 
  
 I use a little screwdriver to get it started and then pull it out with my fingers. When putting another in, make sure the dot / and or notch on the chip and socket line up. It is not good to put them in backwards. 
  


jaywillin said:


> and i was just wondering what was the op amp of choice !


 
  
 I like the LME49990 as it is very neutral. And I know of at least one person who prefers the OPA627AP, which is a little warmer.


----------



## kvtaco17

gibosi said:


> I use a little screwdriver to get it started and then pull it out with my fingers. When putting another in, make sure the dot / and or notch on the chip and socket line up. It is not good to put them in backwards.
> 
> 
> I like the LME49990 as it is very neutral. And I know of at least one person who prefers the OPA627AP, which is a little warmer.


 
 Man, you can use my name and accuse me of liking the 627AP better lol! I like the little bit of added warmth, it gives a a touch more body to the sound.


----------



## jaywillin

gibosi said:


> I use a little screwdriver to get it started and then pull it out with my fingers. When putting another in, make sure the dot / and or notch on the chip and socket line up. It is not good to put them in backwards.
> 
> 
> I like the LME49990 as it is very neutral. And I know of at least one person who prefers the OPA627AP, which is a little warmer.


 
  
  


kvtaco17 said:


> Man, you can use my name and accuse me of liking the 627AP better lol! I like the little bit of added warmth, it gives a a touch more body to the soun


 
 i suppose i could just get a couple to start with, and go until i find THE one !
 thanks guys


----------



## gibosi

kvtaco17 said:


> Man, you can use my name and accuse me of liking the 627AP better lol! I like the little bit of added warmth, it gives a a touch more body to the sound.


 
  
 Sorry about that!  I couldn't remember how to spell your user name and I was in a bit of a hurry and too lazy to look it up.. lol


----------



## jaywillin

man, do some searching on ebay, you get a lot of choices, dual mono, dip adapter, new used (used?) lol


----------



## TrollDragon

Well it is with a heavy heart that I have to report that I have removed my strapping switches from the MK IV. The past while I have had this hum in the background and every tube I put in seemed to be very microphonic. Enough was enough, I totally disassembled the MK IV tonight, removed my switch array, cut the ends off of ALL the factory wires, restripped and retinned them all and put it back together. When I powered it up this time the background was black, not a bit of hum to be found. I'll just have to strap the old way and all will be good.

Too bad as it was really convenient to have the switches, I used shielded wire and even ran grounds to the shield which sort of alleviated some of the hum but not all. Three times this weekend I had it apart and the last time was the end.

So the back chassis is too far to run pin wires in my humble opinion and I was not going to drill into the front case as that is a thick piece of aluminium, and I know it would look like dogs dinner on the MK IV.


----------



## Artsi

trolldragon said:


> Well it is with a heavy heart that I have to report that I have removed my strapping switches from the MK IV. The past while I have had this hum in the background and every tube I put in seemed to be very microphonic. Enough was enough, I totally disassembled the MK IV tonight, removed my switch array, cut the ends off of ALL the factory wires, restripped and retinned them all and put it back together. When I powered it up this time the background was black, not a bit of hum to be found. I'll just have to strap the old way and all will be good.
> 
> 
> 
> ...



 


With mk II it's short way from front panel. EF95, EF92 and 7-2 strap works via switches without any extra hum or noise, but 7-1 hums. It could be something from chassis and switches. I even changed wall socket to safe ground model and no help.


----------



## TrollDragon

artsi said:


> trolldragon said:
> 
> 
> > Well it is with a heavy heart that I have to report that I have removed my strapping switches from the MK IV. The past while I have had this hum in the background and every tube I put in seemed to be very microphonic. Enough was enough, I totally disassembled the MK IV tonight, removed my switch array, cut the ends off of ALL the factory wires, restripped and retinned them all and put it back together. When I powered it up this time the background was black, not a bit of hum to be found. I'll just have to strap the old way and all will be good.
> ...


 

 Yes that is strange indeed, have you tried soldering the 7-1 wires to them selves just off the switch as a test? I had radio signals coming in on mine for a bit today as I was moving the switch wires around with the back cover off. Placement of the wires has a great infulence on the hum and the capacitance in your fingers does too as you come close to the wires or move them.
  
 Good that yours works, I didn't use 7-1 very much myself, I am not sure it you do so it might not be a problem.
  
 Looking forward to seeing your Octal Conversion!
  
 The Octal's are starting to get a little big in size, might be time to look into a Darkvoice 336SE or a La Figaro 336C the point to point wiring on them and the open bottom is so much easier to work on and I really do like the look of those Tung Sol 5998's in the power supply.


----------



## Artsi

trolldragon said:


> Yes that is strange indeed, have you tried soldering the 7-1 wires to them selves just off the switch as a test? I had radio signals coming in on mine for a bit today as I was moving the switch wires around with the back cover off. Placement of the wires has a great infulence on the hum and the capacitance in your fingers does too as you come close to the wires or move them.
> 
> Good that yours works, I didn't use 7-1 very much myself, I am not sure it you do so it might not be a problem.
> 
> ...


 
 I have not missed 7-1 strap, so haven't used more time to solve hum problem.
  
 I have been thinking 6A6 tubes as power. 
	

	
	
		
		

		
		
	


	




 They should be big enough for BOXZILLA. Heater pins are 4mm thick and others 3.2mm. This is going to be some serious tube rolling. There aren't many big tubes that use suitable heater current.


----------



## TrollDragon

artsi said:


> I have not missed 7-1 strap, so haven't used more time to solve hum problem.
> 
> I have been thinking 6A6 tubes as power.
> 
> ...


 

 The 6N7 is the version with an Octal base but like the 6A6 it is a common cathode tube, I don't know how you would use it as a power tube without major board rework.


----------



## Artsi

trolldragon said:


> The 6N7 is the version with an Octal base but like the 6A6 it is a common cathode tube, I don't know how you would use it as a power tube without major board rework.


 
 6A6 and 6N7 could be nearly impossible to get to work. Since they do not have separate cathodes. If i have understood right, little dot uses double triode powertube somehow like serial?


----------



## Audiofanboy

I'm sticking with the regular power tubes lol! I doubt I'd find anything much better than what I have now anyway... Besides, now that I've been reminded of the sheer size of those octal double triodes -no wonder they call the later tube types "miniatures"- my heart is wavering... Progress & testing new grounds, or "stick with what you have"? I have a feeling, the latter option may not get much love though lol...
  
 OK, this time for real, I'm selling my father's (or my secondary, depending) Little Dot MK IV SE.
  
http://www.head-fi.org/t/687709/little-dot-mk-iv-se-220v-tube-headphone-amp-preamp-eu-sale-no-customs
  
 Just putting it out here in case anyone is interested; most of you couldn't care less since you don't live in Europe though... But anyway, for the European head-fiers that might be interested.


----------



## TrollDragon

^^There is the great deal on an SE for you MIKELAP! Resolder two wires on the back panel and she's good to go for 120V. With super tubes already installed to boot!


----------



## MIKELAP

trolldragon said:


> ^^There is the great deal on an SE for you MIKELAP! Resolder two wires on the back panel and she's good to go for 120V. With super tubes already installed to boot!


 
 Looks like 250 euro is $360.00 canuck dollars !!!!!!!!!!!!!!


----------



## mordy

Hi AFB and Gibosi,
  
 My retired engineering friend (78 years old and going strong!) came to the rescue and wired and soldered the Vector adapters to a 9 pin socket. The design is similar to AFB's flying tube, but more like a _hanging_ tube. My friend does not think that the tube hanging upside down will affect anything. After some problems with a dead left channel that was traced to a soldering point everything finally works. I am really happy!
  
 Right now I am listening to a Sylvania 12AX7A tube. All I can say is that in comparison with the best 6AV6 tubes this tube beats them hands down. First impression is *MORE* of everything: more bass, more midrange, more treble, more musicality, more detail, more soundstage, more dynamics. It is like this tube has much more energy than what I experienced before. What is striking at this early stage is the bass slam, dynamics, and and the midrange warmth.
  
 I have to apologize to AFB for asking what the advantage is of the the 12A7 tubes over the 6AV6 tubes which are supposed to be one half of a 12A7 tube.
  
 Now to the nitty gritty: If I understand correctly I could connect a 6 Volt tube such as the 6BQ7 without any changes to the wiring except connecting pins 8 and 9 on the tube itself to eliminate ground hum. Is this correct?
  
 Next question: Post #3645 by Gibosi and AFB is a wiring instruction table for using 12A7 tubes. (Many thanks!) Looking at Gibosi's amp on post #3625 it seems to me that right and left is the opposite of post #3545. In post #3545 the left channel has five connections to the the adapter, and the right adapter has three connections.
 It seems to me that the picture on Post #3525 has the opposite; the left channel has three connections, and the right channel 5 connections.
  
 Did I see correctly, and if so, what is the correct way of right and left?
  
 PS: I asked my friend why the Vector adapters are designed to be so difficult to work with. He replied that by making them basically unsuitable for taking apart they could sell more adapters after you got stuck and could not put it together again....


----------



## gibosi

mordy said:


> Now to the nitty gritty: If I understand correctly I could connect a 6 Volt tube such as the 6BQ7 without any changes to the wiring except connecting pins 8 and 9 on the tube itself to eliminate ground hum. Is this correct?


 
  
 First, congratulations! 
  
 The necessary changes have to do with the heaters. For 12AX7 tubes, pin 9 functions as part of the heater circuit.  For 6BQ7 tubes, pin 9 functions as a shield between the two triodes. Currently, for the 12AX7, you have pin 9 connected to either pin 3 or pin 4 on the adapter. (Probably pin 4 if you used post #3645). Further, you tied tube pins 4 and 5 together and connected both of them to pin 3 on the adapter.. 
  
 To switch to the 6BQ7:
  
 Untie tube pins 4 and 5.
 Connect tube pin 4 on the socket to pin 3 on the adapter.
 Connect tube pin 5 on the socket to pin 4 on the adapter.
     Now you have the heaters connected correctly
  
 Disconnect tube pin 9 from pin 4 on the adapter
 Tie tube pins 8 and 9 together
     Now you have the shield grounded properly.
  


mordy said:


> Next question: Post #3645 by Gibosi and AFB is a wiring instruction table for using 12A7 tubes. (Many thanks!) Looking at Gibosi's amp on post #3625 it seems to me that right and left is the opposite of post #3645. In post #3645 the left channel has five connections to the the adapter, and the right adapter has three connections.
> It seems to me that the picture on Post #3625 has the opposite; the left channel has three connections, and the right channel 5 connections.


 

 Yes, I can see that this might be confusing. Five connections equals the triode (3 connections) plus the heaters (2 connections). I don't think it really matters which side you use to supply current to the heaters, left or right. Use which ever side is more convenient.


----------



## TrollDragon

Here is the listening station for the next two and a half weeks... I will be sad when the LCD 3's have to go on to the next lucky recipient, so they will be well enjoyed while I have the opportunity.


 And now back to your regularly scheduled Dual Triode rolling.


----------



## mordy

Hi Gibosi,
  
 Thanks for your answer and instructions. Just to clarify, do I only need to change one of the adapters?
  
  Seems that tube pin 4 and socket 3 already are in place - only that the lead for tube pin 5 also goes to socket 3?
  
 Connecting tube pins 8 and 9, can I just wrap a 30 gauge wire wrap wire around the pins, or do they have to be soldered?


----------



## gibosi

mordy said:


> Thanks for your answer and instructions. Just to clarify, do I only need to change one of the adapters?
> 
> Seems that tube pin 4 and socket 3 already are in place - only that the lead for tube pin 5 also goes to socket 3?
> 
> Connecting tube pins 8 and 9, can I just wrap a 30 gauge wire wrap wire around the pins, or do they have to be soldered?


 
  
 For your 12AX7, both tube pins 4 and 5 are connected to socket 3. To use your 6BQ7, the lead for tube pin 5 must be disconnected from socket 3 and connected to socket 4. And tube pin 9 must be disconnected from socket 4 and connected to tube pin 8.
  
 These connections do not have to be soldered as long as you have a very tight mechanical connection.


----------



## Audiofanboy

mordy said:


> I have to apologize to AFB for asking what the advantage is of the the 12A7 tubes over the 6AV6 tubes which are supposed to be one half of a 12A7 tube.
> 
> Now to the nitty gritty: If I understand correctly I could connect a 6 Volt tube such as the 6BQ7 without any changes to the wiring except connecting pins 8 and 9 on the tube itself to eliminate ground hum. Is this correct?
> 
> ...


 
  
 I think the 12Ax7 types are just made "better" (i.e., better construction, alloys used, design...) than their single triode "equivalents" -which are only that on paper really- designed for different applications like a three-in-one tube for car radios (detector, auto-volume control (or something...?) and amplification). The 12AX7 is basically _just_ a high gain double triode, designed to do _just_ that (voltage gain), and do it at least decently.
  
 Yeah, different people have been wiring their adapters one way or another. My 12Ax7 adapter has the -three- heater pins wired to the left socket, while my -to be soon put to use- 6DJ8 adapter has the -two- heater pins and the shield wired to the right channel like all the cool kids (just because no one has managed to get rid of that ground through the left socket yet, and I'd rather be on the winning team lol).
  


gibosi said:


> For your 12AX7, both tube pins 4 and 5 are connected to socket 3. To use your 6BQ7, the lead for tube pin 5 must be disconnected from socket 3 and connected to socket 4. And tube pin 9 must be disconnected from socket 4 and connected to tube pin 8.
> 
> These connections do not have to be soldered as long as you have a very tight mechanical connection.


 
  
 I agree that a tight mechanical connection is more than enough (wire leads squeezed tightly between the adapter shell and metal taps. I've had solder points burst or wires break (my wiring was way too tight on my 12Ax7 adapter) on my DIY adapters, but even when I manhandled the device back into submission and resoldered wires without taking anything apart, the wires on the Vector adapter side didn't even budge. Basically, the connection is more solid on the adapter side than on the socket side in my case... My second adapter is better though.


----------



## gibosi

audiofanboy said:


> Yeah, different people have been wiring their adapters one way or another. My 12Ax7 adapter has the -three- heater pins wired to the left socket, while my -to be soon put to use- 6DJ8 adapter has the -two- heater pins and the shield wired to the right channel like all the cool kids (just because no one has managed to get rid of that ground through the left socket yet, and I'd rather be on the winning team lol).


 
  
 I am pretty sure that the shield and the heaters need to be connected to the same adapter. But I am not sure about the two triodes....
  
 I have tried only one configuration and it works! 
  
 Pins 1, 2, and 3 (triode #1) to one adapter (the left one) and pins 6, 7, and 8 (triode #2) to the other adapter (the right one). And then the heaters and shield to the same adapter as triode #2.
  
 So if the heaters and the shield need to be on the same adapter, does it matter if it is triode #1 or triode #2? I do not know....


----------



## bundy

edgard varese said:


> Texas Instruments shipped me a pair of OPA2107 op amps - for free - and I'm in Christchurch.  All you need to do is register on their site and request a sample.


 
 Thanks for that i went to there site & i filled out all of there form's. It's in the post as you said for free that has made my day. I  wonder how long it takes to get to New Zealand. In my boring life ( recovering from spine surgery) this is a little bit of excitement i feel like a big kid again. I'l let you know when it arrives. Thanks again very much


----------



## gibosi

In today's mail came 4 Voskhod 6N2P-EV, manufactured in 1973. These are sturdy tubes with rhodium pins and they exude quality. The 6N2P is purported to be a 6-volt version of the 12AX7, but we need to configure our adapters for 6DJ8 tubes. And these were relatively cheap. I paid $23.00 for four of them shipped. That is, $9.00 for four tubes plus $14.00 / shipping from Tbilisi, Georgia, to the US.
  
 Artsi reports that these are excellent tubes, so I am anxious to get mine burned in....


----------



## Edgard Varese

bundy said:


> Thanks for that i went to there site & i filled out all of there form's. It's in the post as you said for free that has made my day. I  wonder how long it takes to get to New Zealand. In my boring life ( recovering from spine surgery) this is a little bit of excitement i feel like a big kid again. I'l let you know when it arrives. Thanks again very much


 
  
 It takes about a week or so, quite prompt service.  Good luck with your recovery!


----------



## Artsi

gibosi said:


> In today's mail came 4 Voskhod 6N2P-EV, manufactured in 1973. These are sturdy tubes with rhodium pins and they exude quality. The 6N2P is purported to be a 6-volt version of the 12AX7, but we need to configure our adapters for 6DJ8 tubes. And these were relatively cheap. I paid $23.00 for four of them shipped. That is, $9.00 for four tubes plus $14.00 / shipping from Tbilisi, Georgia, to the US.
> 
> Artsi reports that these are excellent tubes, so I am anxious to get mine burned in....


 
 I compared photo of your 6N2P-EV tube, and i see little differences with metal plates to my -76. There could be some differences in sound too.
  
 Got today GE 6BZ7/6BQ7A, RCA 12AZ7A, RCA 12BH7A, RCA 12AU7A, RCA 12AV7, Tung-Sol 12AV7 and GE 12AZ7A.
  
 6BZ7/6BQ7A needs 8-9 pins connected to get rid of hum. Tung-Sol 12AV7, RCA 12AV7 and GE 12AZ7A works in EF92 mode without hum. Weird that RCA 12AZ7A works perfectly with EF95 mode. 12BH7A is even bigger than 6N6P-IR and it draws 0.6A heater current.


----------



## gibosi

gibosi said:


> In today's mail came 4 Voskhod 6N2P-EV, manufactured in 1973.


 
  
 I have about 20 hours on these and feel that I know their sound well enough to comment. However, as I have recently changed my DAC and the op amp in my LD 1+, I can't really compare these to other tubes at this time -- I am still trying to recalibrate my ears. However, I am very comfortable in saying that these tubes are excellent. They have great bass, nice mids, clean and detailed highs, a nice 3-D stage plus they are very quiet.
  
 Even better, these can be purchased quite inexpensively. Again, 4 premium Voskhod 6N2P-EV for $23.00 shipped, whereas, premium 12AX7 / E83CC typically go for upwards of $50 for only one tube! So if you are interested in rolling double triodes, you can't miss with these. Highly recommended!
  
 ~~~~~~~~
  
 For those of you with the LD 1+, I have rolled in a MUSES02, replacing the LME49990, and I am not going to take it out!  The LME49990 is a great op amp, very neutral, but as others have noted, it can be rather cold and clinical when paired with some tubes. The MUSES02 adds a bit of mid-range presence, bringing vocals slightly more forward. As a result, instruments have more impact and presence and the overall presentation is more musical and toe tapping than the LME49990.
  
 So for a more analytical sound, go with the  LME49990. For a more lively and musical sound, go with the MUSES02.


----------



## Artsi

Something like this is coming soon. Still waiting for many critical components, hope i get them this week. Better leave these 9pin usual double triodes as a driver, i have them so many, better for tube rolling.
  
 If this is not killing my little dot, then it survives everything...


----------



## bundy

gibosi said:


> In today's mail came 4 Voskhod 6N2P-EV, manufactured in 1973. These are sturdy tubes with rhodium pins and they exude quality. The 6N2P is purported to be a 6-volt version of the 12AX7, but we need to configure our adapters for 6DJ8 tubes. And these were relatively cheap. I paid $23.00 for four of them shipped. That is, $9.00 for four tubes plus $14.00 / shipping from Tbilisi, Georgia, to the US.
> 
> Artsi reports that these are excellent tubes, so I am anxious to get mine burned in....


 
 Today i also received in the post a matched pair 6J1P-EV Voshkod the ones with the grooves in the glass, which the guy i brought them from seemed to think that made them special so. At only NZ $22.50 including postage im happy with the price. As for the sound after only 4 hrs burn i like it, not too bright warm bass, vocals ???. But there's plenty of burn time left. I think it is very promercing


----------



## hypnos1

Hi Bundy.
  
 Glad you are recovering nicely from your op - I am sure following the guys on this forum is proving wonderful convalescent therapy! I personally have gained much in the relatively short time since I found this thread - AND it's been great fun...keep up with it...
  
 May I just encourage you to make quantum leaps in this rolling game by taking advantage of the immense time, dedication and effort (not to mention money!) the guys have invested over the past months - tubes have been discovered that will leave the 6J1P way behind, e.g. my personal favourite (as a straight substitute in EF95 setting, with no need for any modification) the Ei 6HM5, which is listed with a link by Gibosi in post #3366, and has had offer of $5 a tube accepted with FREE delivery! Unless you fancy entering the world of double triodes and adapters, that is - which I am only just in the process of sorting out...
  
 Whatever, I wish you all the best in this fascinating, if sometimes frustrating(!) rolling game...


----------



## mordy

Hi Gibosi,
  
 Reading about your positive impressions of the 6N2P-EV tubes.
  
 Is 6N3P (9pin, 0.35A) also a tube that is compatible with the LD amps?


----------



## TrollDragon

artsi said:


> Something like this is coming soon. Still waiting for many critical components, hope i get them this week. Better leave these 9pin usual double triodes as a driver, i have them so many, better for tube rolling.
> 
> If this is not killing my little dot, then it survives everything...


 
 Wow a whole hog conversion!
  
 I'd look into an aluminium enclosure for the top of your LD in the same size, http://www.ebay.com/bhp/aluminum-enclosure to keep the hum and interference down.
 Pick up some chassis mount Octal's and a B9A socket, unsolder the LD's tubes sockets, run wires up to your new sockets from the board holes below and enjoy the conversion!
 Goning to be a sweet mod!


----------



## Artsi

mordy said:


> Hi Gibosi,
> 
> 
> 
> ...



 


6N3P is not easily compatible. Pin order is different. 6N23P is compatible with 6DJ8.

http://www.qsl.net/d/dl7avf/roehren/trioden2.html


----------



## gibosi

gibosi said:


> I have about 20 hours on these and feel that I know their sound well enough to comment. However, as I have recently changed my DAC and the op amp in my LD 1+, I can't really compare these to other tubes at this time -- I am still trying to recalibrate my ears. However, I am very comfortable in saying that these tubes are excellent. They have great bass, nice mids, clean and detailed highs, a nice 3-D stage plus they are very quiet.


 
  
 Rolled my US Amperex 6922 back in and can now provide a quick comparative observation. The Voskhod 6N2P-EV has a good bit more bass than the Amperex and the mids are not as forward. Again, nice tubes, but In my system, the Amperex is still number one. However, I can imagine that the V 6N2P-EV might complement bass-shy headphones very well.


----------



## Audiofanboy

I waited two whole days to give my impressions about my Amperex Orange Globe -thereafter OG like the Lyrists call these- 6DJ8 tube; imagine how hard it was for me to wait that long to post about these!
  
 First, I've got to say that the ebay seller who sold me this tube, mercedesman something, does not muck around, seriously. This tube was in _perfect_ shape! Not even a small fingerprint, perfect silkwriting (and therefore resell value), and obviously strong; so strong in fact, I actually think it was pretty much NOS, as it improved after 10+ hours. People, you're only $37 away from glory! Get to it and contact this guy to get your very own OG (sounds like a cheap TV ad lol: "_get hooked on OGs_").
  
 'Nyway, this is my _best_ tube. Period (until the next one). This truly could be an "end game" tube, and it turns out to be for many people. The differences between good tubes used to be subtle or marked at best, but here the difference with anything else I've tried is obvious and dramatic. Joe's tube lore describes this tube very well on his eponymous webpage, but the one word -OK, two words- that comes to me is _immediate_, and also transparent. I've never heard music sound so immediate and surrounding. You can't _test_ or spend an hour _comparing_ this tube to other tubes, it just draws you in and you just have to listen to the music. Now, that's a head-fi experience for you!
  
 It should be an end game tube, it very well could be as far as my ears are concerned, but just can't stop now that I've seen what a good 6DJ8 can do! So, expect more -albeit less frequent for obvious price concerns- 6DJ8 testing in the following weeks!
  
 Side note: I'm really going back to thinking that it would be a lot easier to just bite the bullet and use pairs of 6DJ8 in our LDs (once one finds his "graal" tube). Small footprint, basic, DIY adapters or Vector-type socket testers for an easier and (for us less handy folks or the less arts & crafty types like me) prettier result (non-destructive two-socket solutions wouldn't be difficult to create, the ram-6DJ8-in-B7G-socket is no longer an acceptable option). On the MK IV SE, it really kind of pains me to ruin the overall esthetics of the amp with _any_ kind of single tube adapter...


----------



## mordy

Hi AFB,
  
 Glad to hear that you see the light at the end of the tunnel. In looking for Amperex 6DJ8 tubes there are many variants.
  
 There is an orange globe PQ. This is Amperex premium quality 10,000 hour tube. (Dutch DR?) Is this what I should look for?
  
 Also plate and getter constructions vary, and the country of manufacturing (Holland or England).
  
 What is the difference between the Beekman Bugle Boy and the Orange Globe?
  
 There are also Tektronix matched pairs available.
  
 Would appreciate advice on the exact type to pick for best sound (picture?)
  
 Perhaps RCA labeled types are the sleepers?
  
 Cheers,


----------



## Audiofanboy

mordy said:


> Hi AFB,
> 
> Glad to hear that you see the light at the end of the tunnel. In looking for Amperex 6DJ8 tubes there are many variants.
> 
> ...


 
  
 Here's an actually pretty good start, despite the "absolute" feeling it give off:
http://www.audioasylum.com/scripts/d.pl?audio/faq/joes-tubes.html
  
 What this Joe dude has to say on 6DJ8 tubes actually seems to be pretty consensual, even 13 years after writing, and most rollers seem to globally agree with his view of the Amp'ex world.
  
 Quoting myself on page 241: "_Alright! I managed to find a single, super strong (as in 20% over NOS) Amperex "Orange Globe" 6DJ8 from the late 60s (so not a "Bugle Boys" 6DJ8 from the early or mid-60s, and not an "Orange Globe" with an A-frame getter from 70 onwards), so the best Amp'ex short of some crazy rare tubes, recommended by all who have tried them. I just communicated with a seller who was selling some very nice pairs for "OK" prices, asked him if he had singles, and obviously he had plenty and was willing to sell them for less than half of the price of a pair (cheaper than buying pairs, which is a bit ironic)._"
  
 Yes, from my understanding, and while many people _love_ the late 50s and 60-66 white label Bugle Boys Amperex 6DJ8 and fewer people the A-frame dimpled getter '69 onwards Orange Globes (OG), the 67-69 basic halo getter OG are often considered to be the best critically speaking -not the most musical or the most _fill-in-the-blank_ but the best basic Amp'ex tube all in all.
  
 http://www.ebay.com/itm/AMPEREX-ORANGE-GLOBE-6DJ8-ECC88-VACUUM-TUBE-1967-MATCH-PAIR-SWEET-SMOOTH-TONE-3-/321232935246?pt=Vintage_Electronics_R2&hash=item4acaf9994e
  
 Here is a basic example of the "Orange Globe" world logo, sold by the same guy who sold me a single tube. See the single support halo getter -and orange world logo- and shape? This is what you're looking for. Though many other Amp'ex tubes are getting riot reviews; but these just happen to be the "gateway drug" because of their rather extreme price/performance ratio (again, these are often considered end game tubes, and yes, $80 is not cheap in my world view, but it's one of the cheapest quality offerings that can be had for much less with time and effort).
  
 I'm only just starting to investigate the _better-than-OG_ Amperex/Philips tubes, so I can't comment on the so-called premium offerings yet. I just started with what is considered as a cheap-ish killer tube, and thought I'd work my way up accordingly -or not!


----------



## Oskari

mordy said:


> Also plate and getter constructions vary, and the country of manufacturing (Holland or England).
> 
> What is the difference between the Beekman Bugle Boy and the Orange Globe?


 
  
 Beekman?
  
 The difference between BBs and OGs is vintage. Also getters changed over the years.
  
 Holland = made by Philips; England = made by Mullard.
  
 Meaning that … an Amperex 6DJ8 is most likely either a Philips ECC88 or a Mullard ECC88.
  
 6DJ8s were not made by Amperex in US. 6922s and 7308s were. (But also by other Philips group factories.)
  


> Perhaps RCA labeled types are the sleepers?


 
  
 RCAs were often relabeled Siemens tubes.


----------



## jaywillin

the first of my 3 different op-amps for the little dot has arrived, don't know which one, haven't opened the package yet
 on the subject of orange globe 6dj8's i just ordered a 1969 pair for my lyr, from mercedesman:

 i had a 1960,A frame, from him already.
 there is just one hitch here though, when i got the 69's, i had forgotten that i'd already ordered a pair of 69's from someone else.
 they haven't arrived as yet, from  the pics, mecedesman's look nicer


----------



## gibosi

mordy said:


> There is an orange globe PQ. This is Amperex premium quality 10,000 hour tube. (Dutch DR?) Is this what I should look for?
> 
> Also plate and getter constructions vary, and the country of manufacturing (Holland or England).
> 
> ...


 
  
 - Orange Globe PQ - It appears that these are standard 6DJ8 / ECC88 with a fancy label, so you don't want to pay extra for them. On the other hand, if they have the 2-stage halo getter as shown in the picture that Jaywillin has posted, and you can get them at a good price, then these are the Orange Globes to get. Tektronix, HP and other labels on standard Orange Globes are fine, but again, not worth paying extra. True SQ and PQ tubes will be labeled 6922 / E88CC or 7308 / E188CC and have gold pins.
  
 - Country of origin - Amperex 6DJ8 manufactured in England are, in fact, Mullards, and they will not sound the same as those manufactured in Holland....
  
 - US-made Amperex 6922 and 7308 versus Holland-made Amperex 6922 and 7308 sound somewhat different. See Joe's Tube Lore for more info. I followed his advice in purchasing my US-made Amperex 6922 and they are to die for. 
  
 http://www.audioasylum.com/scripts/d.pl?audio/faq/joes-tubes.html#6DJ8-2
  
 - Beekman Bugle Boy - I believe you mean Beckman. I purchased a pair of Beckman-labeled, US-made Amperex 6922 / E88CC, with gold pins. Mine are identical to tubes with the Amperex label, but I got them for considerably less. If resale value is important, it might be worth buying Amperex-labeled tubes. If sound is paramount, there are good deals to be had by searching for relabeled tubes.
  
 - RCA did not manufacture 6DJ8 tubes. Therefore, every RCA you see was manufactured by another company, and very often, that company was Siemens.
  
 In summary, I recommend that you try to find an Orange Globe with the two-stage halo getter such as Jaywillin and AFB have purchased. (that is, not an A-frame) . While I do not have these OGs, I do have the white label Bugle Boys and the A-frame OGs and both are excellent tubes, as well. Further, if you would like to try one of the premium tubes, to my ear the US-made Amperex 6922 is superior to my Bugle Boys and OG.


----------



## gibosi

audiofanboy said:


> 'Nyway, this is my _best_ tube. Period (until the next one). This truly could be an "end game" tube, and it turns out to be for many people. The differences between good tubes used to be subtle or marked at best, but here the difference with anything else I've tried is obvious and dramatic. Joe's tube lore describes this tube very well on his eponymous webpage, but the one word -OK, two words- that comes to me is _immediate_, and also transparent. I've never heard music sound so immediate and surrounding. You can't _test_ or spend an hour _comparing_ this tube to other tubes, it just draws you in and you just have to listen to the music. Now, that's a head-fi experience for you!
> 
> It should be an end game tube, it very well could be as far as my ears are concerned, but just can't stop now that I've seen what a good 6DJ8 can do! So, expect more -albeit less frequent for obvious price concerns- 6DJ8 testing in the following weeks!
> 
> Side note: I'm really going back to thinking that it would be a lot easier to just bite the bullet and use pairs of 6DJ8 in our LDs (once one finds his "graal" tube). Small footprint, basic, DIY adapters or Vector-type socket testers for an easier and (for us less handy folks or the less arts & crafty types like me) prettier result (non-destructive two-socket solutions wouldn't be difficult to create, the ram-6DJ8-in-B7G-socket is no longer an acceptable option). On the MK IV SE, it really kind of pains me to ruin the overall esthetics of the amp with _any_ kind of single tube adapter...


 
  
 These are my thoughts as well. The 6DJ8 (and premium variants) seem to me to be the ultimate tube for the LD. The "immediacy" and transparency I am hearing is often simply breathtaking. My cheap little 1+ is flying miles above where any $110 amp should be. And I am sure that the LD IVse, with much higher-quality components and power tubes, is flying even higher! lol.
  
 So my advice... get yourself a set of OGs... relax... and enjoy. 
  
 (And if AFB can find a clean and elegant way to use pairs that would be great! But for the moment, my prototype with flying wires, while ugly, is giving me everything I need.... and more....


----------



## mordy

Thanks for all the answers.
  
 "Perhaps RCA labeled types are the sleepers?"
  
 Re the RCAs it seems I was right (From Joe's Tube Lore):
  
 "A useful tip: RCA never made 6DJ8 family tubes. If it’s an RCA and has a ridged top it’s either an Amperex or a Siemens. I’d watch this brand closely if you stumble on it. Many tube dealers will sell lowly RCA 6DJ8 family tubes for $15 to $20 a tube without realizing that there is European made gold inside. Check the tube’s top for ridges, the label for where it was manufactured and if everything checks out, buy it! This is one of the absolute bargain brands in this tube type."
  
 Seeing tubes in the range of $60-$300/pair made me a little nervous, but luckily there is no lack of offers. After sifting through hundreds of tubes offered, I
 bought a Tektronix 6DJ8 made in Holland tube from 1975 for $6 shipped. Will see what it is when it arrives. In general, I found when looking into 6AU6 tubes (remember those?) that the Tektronix selected tubes were superior.
  
 Have a breadboard on order to make the 6DJ8 adapter. The broken Vector adapter was promised to be replaced by the seller. If the making of the adapter proves too difficult I might vent my frustration by using this breadboard:
  





  
 PS to Oskari: Sorry for the typo on the Beekman tube - should have been Beckman.


----------



## TrollDragon

That bread board needs a little longer handle "To Bring The PAIN".


----------



## bundy

hypnos1 said:


> Hi Bundy.
> 
> Glad you are recovering nicely from your op - I am sure following the guys on this forum is proving wonderful convalescent therapy! I personally have gained much in the relatively short time since I found this thread - AND it's been great fun...keep up with it...
> 
> ...


 
 Hi hypnos1,
   Thank you for your kind words, With the many hours spent in bed since my surgery's i have found this forum to be just that "wonderful convalescent therapy". Thank you for your advice regarding 6J1P Tubes i was just making the most of wot was available here in New Zealand. I think i might have been con'd a bit it said in the add that these voshkod tubes had grooved glass & this made them some wot rare & sort after. Oh well live & learn but i do like the sound. I will look for Ei 6HM5 & see if i can find a pair down this part of the world. I will also go & have a look at the link left by Gibosi. Thanks for all the information & advice all appreciated by this tubee newbee
            Bundy


----------



## MIKELAP

trolldragon said:


> That bread board needs a little longer handle "To Bring The PAIN".


 
 Dont remember  a breadboard ,a hand made of steel was enough.


----------



## TrollDragon

mikelap said:


> Dont remember  a breadboard ,a hand made of steel was enough.


 
 Tis very true.


----------



## gibosi

mordy said:


> Seeing tubes in the range of $60-$300/pair made me a little nervous, but luckily there is no lack of offers. After sifting through hundreds of tubes offered, I
> bought a Tektronix 6DJ8 made in Holland tube from 1975 for $6 shipped. Will see what it is when it arrives. In general, I found when looking into 6AU6 tubes (remember those?) that the Tektronix selected tubes were superior.


 
  
 A manufacture-date of 1975 suggests that this tube is equivalent to a "red label" Amperex. These were manufactured after the A-frame Orange Globes. If you look closely at the getter, it is likely a simple halo getter, and it is different than the beefier two-stage halo getters of the earlier OGs made in the late 1960s. Even so, it is likely still a very good tube, but not quite the same as the OGs that AFB and Jaywillin have.


----------



## mordy

Hi Gibosi,
  
 It probably is the type you describe. It will be a beginning of trying out Amperex 6DJ8 tubes - I don't even have the parts for the adapter yet (waiting for breadboard with socket and Vector replacement).
  
 Below are pictures of my low cost hillbilly 12A7 adapter.
 Parts list: 2 Vector adapters $14
                Old 60's wire 22 gauge free
                9 pin socket ~$5
                Little piece of wood from somewhere free
                Screw from stash free
                Plastic tie 2 cents
                1" electric tape
                Labor free for spider web wiring, but I owe my friend a favor or two
  
 Please: Don't laugh - this is very serious business for me and allows me to stay in the race for the best tube. BTW, as long as I don't touch anything there is no hum (unless I turn up the volume to deafening levels).
  

  

 If necessity is the mother of invention, where do all unnecessary inventions come from?


----------



## MIKELAP

mordy said:


> Hi Gibosi,
> 
> It probably is the type you describe. It will be a beginning of trying out Amperex 6DJ8 tubes - I don't even have the parts for the adapter yet (waiting for breadboard with socket and Vector replacement).
> 
> ...


 
 Was the word fire ever mention during the course of this project by anybody! lol.


----------



## mordy

Hi Mikelap,
  
 I assume that you are referring to the screw holding the socket. The socket itself came with a mounting ring with facilities for two screws to hold the socket in place. If it was designed for this, why do you feel that this setup is a fire hazard?


----------



## gibosi

mordy said:


> Below are pictures of my low cost hillbilly 12A7 adapter.
> 
> Please: Don't laugh - this is very serious business for me and allows me to stay in the race for the best tube. BTW, as long as I don't touch anything there is no hum (unless I turn up the volume to deafening levels).


 
  
 I'm not sure my setup with wires flying everywhere looks any better! lol 
  
 And I think it is great that you posted your pictures. I suspect that all of us have lots of electrical stuff stashed away, and if we take the time to rummage through it, we can often find bits and pieces that we can re-purpose to new uses. Your pictures might help others to think about how they might be able to cobble something together to explore these double triodes. Cheers!


----------



## MIKELAP

mordy said:


> Hi Mikelap,
> 
> I assume that you are referring to the screw holding the socket. The socket itself came with a mounting ring with facilities for two screws to hold the socket in place. If it was designed for this, why do you feel that this setup is a fire hazard?


 
 Its not what i ment mordy  what i ment is maybe somebody else in the household taught it was a fire hasard .Thats what my wife would say to me I was  just kidding mordy sorry


----------



## mordy

Hi Gibosi,
  
 Thanks for your encouraging words.


----------



## stvn758

How tough are these tubes, having a close look at mine they seem quite delicate -  images of shards of glass embedded in my fingers filled my head on first closer inspection. One of mine was a bit wonky so I gave it a little push and it moved, have to look at the manual to see how to remove them but quite happy with them as they are at the moment.


----------



## gibosi

stvn758 said:


> How tough are these tubes, having a close look at mine they seem quite delicate -  images of shards of glass embedded in my fingers filled my head on first closer inspection. One of mine was a bit wonky so I gave it a little push and it moved, have to look at the manual to see how to remove them but quite happy with them as they are at the moment.


 
  
 More context please? What tubes are you talking about?
  
 But generally speaking, unless you drop them on concrete, tubes are pretty durable.


----------



## stvn758

gibosi said:


> More context please? What tubes are you talking about?
> 
> But generally speaking, unless you drop them on concrete, tubes are pretty durable.


 
 I have a Little Dot MKIII, the power tubes looked fragile, not much to grab onto with the two front ones either. I assume they don't require much force to come out?


----------



## gibosi

stvn758 said:


> I have a Little Dot MKIII, the power tubes looked fragile, not much to grab onto with the two front ones either. I assume they don't require much force to come out?


 
  
 You may have heard the term "rolling tubes"? So grab the tube and gently "roll" it so that the top makes a small circle. This will help to loosen it, and then pull it straight up and out. Easy.


----------



## stvn758

gibosi said:


> You may have heard the term "rolling tubes"? So grab the tube and gently "roll" it so that the top makes a small circle. This will help to loosen it, and then pull it straight up and out. Easy.


 
 Thanks.


----------



## mordy

Hi,
  
 Entered the 6DJ8 world going window shopping. First impression is the enormous selection available with hundreds and hundreds of items for sale.
  
 Seems that Amperex is the way to go. Does anybody have any feedback on Japanese manufactured 6DJ8 tubes?
  
 I am getting my receiver back soon. Seems that the blow out of the left channel had nothing to do with the Little Dot. It could be that I moved one speaker and a wire came lose and shorted out the amp.
  
 Speaking of dual triodes I have four 12A7 variants, all Sylvania with red designations printed on the box flaps which indicates replacement tubes. It is possible that these red marked boxes were not the highest quality production items.
  
 Only tried two types so far. One is a 12AX7A that sounds absolutely great. Tried a 12AU7A today but could not stand it - thin and shrill sounding. Go figure?
  
 A couple of the soldered wires came off the Vectors. I am exhausted after going to soldering school and wondering what happens to the melted solder that drips down into the adapter..
  
 Anyhow, everything works and sounds fine now.


----------



## gibosi

mordy said:


> Speaking of dual triodes I have four 12A7 variants, all Sylvania with red designations printed on the box flaps which indicates replacement tubes. It is possible that these red marked boxes were not the highest quality production items.
> 
> Only tried two types so far. One is a 12AX7A that sounds absolutely great. Tried a 12AU7A today but could not stand it - thin and shrill sounding. Go figure?


 
  
 With regard to 12AX7, I have followed Joe's advice and ordered a few 5751s. 
  
 http://www.audioasylum.com/scripts/d.pl?audio/faq/joes-tubes.html#12AX7-3
  
 I was able to pick up a Tung-Sol, GE black plate, and a Sylvania JAN black plate, and hope to get to them eventually. However, I will admit that I will be approaching them with a fair amount of prejudice, as I seriously doubt that they can compete with the 6DJ8s that I have become accustomed to.....


----------



## TrollDragon

mordy said:


>


 
  
 For those that don't know I'd like to issue a safety warning on open connections like this, I am NOT picking on you personally mordy, it is just your setup here is a great example. 
  
 On the unmodified Vector extenders there can be upwards of *155 Volts *exposed on terminals 5 & 6 and if you have the LD in EF92 mode on terminal 7 as well. (Obviously the same applies to the terminals on the bare B9A socket since that is where the wires terminate.)
  
 If you are going to work with this kind of setup then do your work with the power off and don't forget that the capacitors in the LD will take a few minutes to discharge.
 There is still dangerous levels with the power switch turned off and the mains cord unplugged if the amp has been on for a few minutes or more.
  
 Try it for your self, while listening to some music, shut the amp off and pull the AC cord out if you wish just to see how long it takes for the music to fade out. These are the 250Volt capacitors in the amp discharging that is keeping the music playing and the voltage on the above terminals will still be present. I believe the music stops because the tube cooled with no heater voltage before the capacitors discharged all their reserve.
  
*So if you have to touch or adjust anything with the power on then only work with one hand. Keep the other hand behind your back or in your pocket.*
  
 I you had a hold of the amp chassis and managed to touch terminal 5, 6 or 7 depending on the mode, it would be similar to grabbing the 110V Mains with a wire in each hand.
  
 The LD transformer is rated for 100mA on the B+ line and referencing Charles Dalziel's chart, you are past the point where you can voluntarily let go.

  
 So seriously take heed of this warning with these open point to point connections. 
 I really don't want to see anyone get hurt and If this warning makes just one person who is unaware of the possible dangers take some precautions, then that is good.


----------



## Artsi

I have some battle going on with two tubes.

  

 Westinghouse 6DJ8 -63 made in USA and RCA 12AZ7A made in usa. Ring getters and RCA with black plates.
 These two delivers something like honey to my ears. Real jaw droppers to me. Westinghouse is microphonic, but only if i knock the amp.
  
 Comparing these to still very good 6N2P-EV it's easy to find bad things from it. 6N2P bass is boomier and lacks some control. Otherwise sound with these two is more clarity and clear brightness.
  
 NUFF SAID.
  
 Could be little rare ones, found only 1 of each identical to these from ebay.
http://www.ebay.co.uk/itm/Westinghouse-6DJ8-ECC88-Rohre-Lampe-Valvola-Valvula-/160891339939
http://www.ebay.co.uk/itm/Radio-Tubes-12AZ7A-12AZ7-RCA-Black-Plate-Orange-NOS-/290897243868
  
 Btw amperex 6DJ8 -74 Holland with A-getter structure sound only mediocre to good.


----------



## superdux

i fell for tube mania and ordered the first Voskhod 6ZH1P-EV i saw on Ebay. Then while completing my mammut task of reading this entire thread i stumbled upon the same valves nearly half the price(they were just named differently i think without the Z and a J). damn how could i have not seen? guess the seller had a nice day as i paid him
 Oh btw i ordered some

```
JHY-6AK5
```
 from ebay.They are from 1945.They are also unmatched but same production year and month so i hope nothing goes wrong in my amp. So i was wondering about jumper setting?any help pls?


----------



## MIKELAP

trolldragon said:


> For those that don't know I'd like to issue a safety warning on open connections like this, I am NOT picking on you personally mordy, it is just your setup here is a great example.
> 
> On the unmodified Vector extenders there can be upwards of *155 Volts *exposed on terminals 5 & 6 and if you have the LD in EF92 mode on terminal 7 as well. (Obviously the same applies to the terminals on the bare B9A socket since that is where the wires terminate.)
> 
> ...


 
 +1


----------



## gibosi

I have been burning in a Voskhod 6N23P, 1978, with silver shields, and after about 20 hours I am very impressed, great bass, transparency, 3-D stage and liquidity. This reviewer ranks it among the best of the Voshkods:
  
 http://www.head-fi.org/t/549508/schiit-lyr-the-tube-rolling-thread/8595#post_9625620
  
 Highly recommended!


----------



## mordy

Hi Artsi,
  
 The RCA tube has a date code BW - Feb 1968
  
 http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&ved=0CC4QFjAA&url=http%3A%2F%2Fmysite.verizon.net%2Ftubetronic%2FPDF_FILES%2FRCA%2520DATE%2520CODES.pdf&ei=1sdzUvaRL7O_sQSQ8oDYBg&usg=AFQjCNEcbsMGwlSumKFcocuP4HLEcjBDjg&sig2=N_i3wBe8h8W2BbIY1KID4Q&bvm=bv.55819444,d.cWc


----------



## mordy

Hi Trolldragon and Mikelap,
  
 Thanks for the advice and warnings about the open contacts on my temporary setup.
  
 Is there less dangerous voltage on the EF95 setting which is what I am using for the 12A7 tubes?
  
 If I always shut off the LD before I make any changes and wait a couple of minutes, does this make it safe to handle?
  
 TD - how is your copper adapter coming along?


----------



## gibosi

superdux said:


> i fell for tube mania and ordered the first Voskhod 6ZH1P-EV i saw on Ebay. Then while completing my mammut task of reading this entire thread i stumbled upon the same valves nearly half the price(they were just named differently i think without the Z and a J). damn how could i have not seen? guess the seller had a nice day as i paid him
> Oh btw i ordered some
> 
> ```
> ...


 
  
 6AK5 = EF95, so the same setting as your Voskhod 6ZH1P-EV.
  
 And I think JHY =  CBS-Hytron....


----------



## mojorisin35

gibosi said:


> 6AK5 = EF95, so the same setting as your Voskhod 6ZH1P-EV.
> 
> And I think JHY =  CBS-Hytron....


 

 yes they are  CBS hytron


----------



## TrollDragon

Hi mordy!

Doesn't matter which modes the amp runs in as long as the Anode wire is exposed it will have high voltage on it, in EF-95 mode the Anode is on terminals 5 & 6, in EF-92 mode all that jumper on the bottom of the amp does is short pin 7 to 5 & 6, then you have 3 terminals with the high voltage exposed.

Working with the power off and letting the amp discharge before doing anything is a safe way to be.

On the Copper adapter... I am still waiting for Chinese sockets delivered by rickshaw across the North Pole to Canada to arrive... I will post it all up with instructions when they do. If you guys havn't moved onto Octal sockets by the time they get here.


----------



## mordy

Hi Gibosi,
  
 Just to make sure I am doing things right in wiring for 6DJ8:
  
 9 Pin socket                                 Left LD socket                    Right LD socket
  
 1 plate triode 1                                     5
 2 grid triode   1                                     1
 3 cathode triode 1                                 2
 4 heater                                                3
 5 heater                                                4
 6 plate triode 2                                                                                 5
 7 grid triode 2                                                                                   1
 8 cathode triode 2 and 9 tie together
                
 Can I use a jumper for tying together pins 8&9, or do they have to be soldered to the tube pins?
  
 Thanks for your input,
  
 Mordy


----------



## gibosi

mordy said:


> Hi Gibosi,
> 
> Just to make sure I am doing things right in wiring for 6DJ8:
> 
> ...


 
  
 No soldering is required.....
  
(My changes in red)
  
 I believe that the heaters and the shield need to be on the same adapter, so I have moved the heater connections to the right adapter. (As mine is setup using the right adapter, I know it works). Since you have a breadboard 9-pin socket coming, you tie pins 8 and 9 together with a small jumper wire using the compression terminal blocks located adjacent to the socket on the breadboard. So no soldering is required.
  
 And if you want to use 12AX7 tubes, you make the wiring changes using the compression terminal blocks. You do not have to touch the adapters.


----------



## Artsi

Some relief for this serious tube rolling:





 have fun


----------



## gibosi

If you have your LD set up to use 6DJ8s, but would like to be able to roll an occasional 12AX7, you could build a little adapter:
  
 http://www.head-fi.org/t/549508/schiit-lyr-the-tube-rolling-thread/7185#post_9431142


----------



## superdux

I have a question about a socket saver if you would have a look if thats the right one for my LDMKIII (i´ve also contacted the seller).
http://www.ebay.de/itm/231071553119?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649
 i was wondering if i´d need such a socket saver if i would swap tubes maybe 20 or 30 times.


----------



## gibosi

superdux said:


> I have a question about a socket saver if you would have a look if thats the right one for my LDMKIII (i´ve also contacted the seller).
> http://www.ebay.de/itm/231071553119?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649
> i was wondering if i´d need such a socket saver if i would swap tubes maybe 20 or 30 times.


 
  
 I cannot read German, but as it has 7 pins it looks fine to me.
  
 But if you think you will swap tubes only 20 or 30 times over the life of your LD, then you don't need these. Some members of this forum have swapped tubes hundreds of times and their sockets are fine.


----------



## superdux

thx for the replys guys, i´m really enjoying this hobby!


----------



## Nic Rhodes

For those looking for 6DJ8 RCAs, I don't think RCA ever made these and all I have seen a european rebadges at much less cost. They are therefore ag great bargain. Most are Amperexes, Siemens and I think Mullards.


----------



## bundy

edgard varese said:


> It takes about a week or so, quite prompt service.  Good luck with your recovery!


 
 Thank you very much my recovery is going well. It was very prompt service they arrived in 4 days Fed-x all the way. It was actually fun tracking it around the world. I don't know if you can tell but I'm new to computers & stuck in bed so you get your fun where you can LOL. But the good news wot a difference in the sound from the old op-amp i love it it's so much more alive.
     Thanks Bundy


----------



## Artsi

The BOXZILLA! Got finally this son of a b**** work. And i can say that the box is pretty full of stuff. 
  

  
 I rolled to my lil dot mk2 some bigger tubes. All tubes are in use. 6SN7GT is a secret ingredient! Switches are for noval base doubletriode to switch between 6.3 and 12.6v heaters etc. Sound seems to be just like it should be.


----------



## gibosi

artsi said:


> I rolled to my lil dot mk2 some bigger tubes. All tubes are in use. 6SN7GT is a secret ingredient! Switches are for noval base doubletriode to switch between 6.3 and 12.6v heaters etc. Sound seems to be just like it should be.


 
  
 It looks amazing! 
  
 I wonder.... Why did you use a 6SN7 instead of a 6SL7?


----------



## Artsi

gibosi said:


> It looks amazing!
> 
> I wonder.... Why did you use a 6SN7 instead of a 6SL7?


 
 6SN7 works as a "power first stage". Drives both channels and 6A6s are working in parallel. I have 6SL7 too, but it won't work as good.


----------



## gibosi

artsi said:


> 6SN7 works as a "power first stage". Drives both channels and 6A6s are working in parallel. I have 6SL7 too, but it won't work as good.


 
  
 I have ordered a Tung-Sold 6SL7 and a 12AX7 to 6SL7 adapter. But while you take GIANT steps, I take baby steps! lol


----------



## mordy

Hi Artsi,
  
 Where is it going to end? Maybe with these 20A beauties:
  





  
 http://www.ebay.com/itm/MATCHED-PAIR-AMPEREX-JAN-CEP-279A-AUDIO-TRIODE-AMPLIFIER-TUBES-NOS-279-A-RARE-/271231648388?pt=Vintage_Electronics_R2&hash=item3f26aa8284
  
 Only $4000


----------



## gibosi

Does anyone know which company manufactured these "Spezial" E88CC tubes?  (Oskari???)
  
 From the getter structure, I assume a Philips / German company.... but which one?


----------



## MIKELAP

gibosi is this connection schematic on page 243 still ok. Thanks


----------



## gibosi

mikelap said:


> gibosi is this connection schematic on page 243 still ok. Thanks


 
  
 Yes, for 12AX7 tubes, this is correct. 
  
 And if you have the heaters and shield (pin 9) connected to the right LD adapter for 6DJ8 tubes, it might make things a little easier to keep the heaters on the right LD adapter, like so:
  
 12AX7
  
 9-pin socket           left LD socket        right LD socket
  
 1 plate triode 1                5                        
 2 grid triode 1                  1
 3 cathode triode 1            2
 4 heater                                                    3                         
 5 heater                                                    3                         
 6 plate triode 2                                           5
 7 grid triode 2                                             1
 8 cathode triode 2                                       2
 9                                                              4


----------



## Oskari

gibosi said:


> Does anyone know which company manufactured these "Spezial" E88CC tubes?  (Oskari???)
> 
> From the getter structure, I assume a Philips / German company.... but which one?


 
  
 I'm hardly a getter specialist, and whoever took those photos is not much of a photographer. I'm sorry, but I need better clues, hopefully in focus. Even so, those are not the same tube, perhaps even different manufacturers.


----------



## gibosi

oskari said:


> I'm hardly a getter specialist, and whoever took those photos is not much of a photographer. I'm sorry, but I need better clues, hopefully in focus. Even so, those are not the same tube, perhaps even different manufacturers.


 
  
 These pictures are from two different auctions, two different eBay vendors, so yes, two different Spezial tubes.
  
 I have learned a little more. After contacting the vendor about the first tube, I was told Hoges made it. But we know that Hoges was not a manufacturer, but a German rebrander. So, like Halston and Zaerix, there is no way to easily know who manufactured that Hoges "Spezial" E88CC tube. From what I can see in the blurry photo, it does not resemble any European E88CC I have seen. In the tube in the second photo, a Philips-style getter is evident, but even so, this tube could have been made in GB, Holland or anywhere else Philips had a factory.


----------



## gibosi

A couple pictures:
  
 First, GE 5751. This is a premium industrial/military version of the 12AX7. Note the double layers of mica, plus a third mica just below the getter. Also note the steel rods connecting the middle and lower mica. Unfortunately, I haven't been able to spend any time with this tube.....
  

  
 And second, Voskhod 6N23P, 1978, with silver shield. I would rate this tube right up there with my USA-Amperex 6922. The Amperex is just a bit brighter, but both have great detail and transparency, and are toe-tappingly musical to boot.


----------



## Artsi

I have headphone measuring head that looks like this:

 So here is frequency response curves for two different sounding sets of tubes with bassport modded akg K701.

 Lines go pretty much same, so you see clearly red line only little from start. EF93 no brand tubes sounds like s***. But it is not measurable this way.


----------



## Audiofanboy

Nice endeavors as usual around here, especially the Crazy Box (tm) with an extra tube stage, which the manufacturing of is way above my league lol -and to think people used to think _I_ was doing some crazy stuff... The times, they change...
  
 Anyway, meanwhile in calmer waters, I found a single - I was looking for a pair but pairs were way out of my budget- Amperex USN-CEP 6922 tube for 40 some UK pounds shipped, which isn't so bad if you look on the bright side.
  
 What's interesting is that it has the exact - and I mean exact - same factory codes _and_ date codes as gibosi's Beckman 6922 tubes. These have been getting very good (as in top tier) reviews on the Lyr thread and elsewhere, and are supposed to be somewhat selected Amperex "white label PQ" 6922 for the US Navy. It's probably the exact same tube, which was intended for premium use anyway.
  
 Looking forward to comparing it with the OG tube; hopefully that'll round out the Amperex/Philips family for me (no, I won't spend $1K on pinched waist Amp'ex tubes lol). If there is a next tube, it will either be a pair (as in an end-game pair) to use in a prettier way on my IV SE, or something new and European. But the way things are looking now, I may just wind it down a little, since my last tube is already tremendously satisfying and since I expect the USN-CEP to give me the same satisfaction. A step up would immediately be something like a CCa, and I'm not using tubes that expensive on a rigged amplifier lol.


----------



## Anaximandros

artsi said:


> The BOXZILLA! Got finally this son of a b**** work. And i can say that the box is pretty full of stuff.
> 
> 
> 
> I rolled to my lil dot mk2 some bigger tubes. All tubes are in use. 6SN7GT is a secret ingredient! Switches are for noval base doubletriode to switch between 6.3 and 12.6v heaters etc. Sound seems to be just like it should be.


 
  
 This is freaking awesome!
  
 I've been lurking this thread since I bought a LDK MK III and began my tuberolling journey with the recommended tubes mentioned in the first post. After getting some old 1960's Novosibirks I thought the journey was over, then I stumbled upon posts about heptodes and pentodes and bought some of them too... then after a while after I finished reading this thread some of you rolled in double triodes and Artsi made his little box I was eager to build it myself. And now that big ass monster O_O 
  
 Can you post a guide like you did with your little adapter box? 
  
 And thanks to mordy, Audiofanboy, Gibosi etc.. for your constant input and new ideas. It was a blast reading everything posted in here. I made an account just because of this thread ^^


----------



## i luvmusic 2

i'm about to buy a spare power tubes(that two big tubes in back of unit i think they are called power tubes) any suggestion on which type/brand? i saw some ECC99 are those compatible with Little Dot MK III?


----------



## mordy

Hi I love music 2,
  
 There is much less of a selection of power tubes than driver tubes. The best are the 6H30Pi-DR/6N30-DR  tubes that today run in the $200-$250 range/pair. An excellent and much less expensive alternative is the 6N6P-IR that cost under $35/pair. Don't bother to look for anything else.
  
 All these tubes are made in Russia. With the fall of communism the quality went down. It is best to look for older tubes made before 1990 and preferably from the 70's and 80's. Count on a month to receive them (sometimes faster).


----------



## TrollDragon

Managed to salvage a pair of B9A tubes from an old Rogers Console.
  
 Rogers 12AX7 - I65 & r3L4 code which is Phillips Ontario.
 Phillips MiniWatt ECC85 - tU3 & a "Right Angle Triangle symbol"4C3 code which is Philips Heerlen.
 (Filament current possibly a little to high on the ECC85.)

  

  
 Now I can play, I have a salvaged B9A socket and I'll make up some plugs for the LD's B7G sockets in the next few days.


----------



## i luvmusic 2

mordy said:


> Hi I love music 2,
> 
> There is much less of a selection of power tubes than driver tubes. The best are the 6H30Pi-DR/6N30-DR  tubes that today run in the $200-$250 range/pair. An excellent and much less expensive alternative is the 6N6P-IR that cost under $35/pair. Don't bother to look for anything else.
> 
> All these tubes are made in Russia. With the fall of communism the quality went down. It is best to look for older tubes made before 1990 and preferably from the 70's and 80's. Count on a month to receive them (sometimes faster).


 
 Thanks  6N6P-IR is good enough i just need a spare just incase the one i have would give up.again THANK YOU.


----------



## MIKELAP

Received some Amperex Bugleboy 6DJ8  tubes today made in Holland .Now if i can get my sockets I will get started on 6 and 12 volts adaptors.


----------



## mordy

Hi I Love Music 2,
  
 My suggestion is to save the first pair as a spare and use the IR tubes instead - they are that much better than the stock 6N6Pi tubes.
  
 Good Luck!


----------



## i luvmusic 2

mordy said:


> Hi I Love Music 2,
> 
> My suggestion is to save the first pair as a spare and use the IR tubes instead - they are that much better than the stock 6N6Pi tubes.
> 
> Good Luck!


 
 CRAP you said 6N6P-IR i just purchased 6N6P-i you know what  for $39 shipped i guess it's better than having no Spare at all.


----------



## TrollDragon

Just test fitting a new design for the B9A adapter. I still need to wire up and epoxy the socket, make the pins and solder the unit together.
 A little spit, polish, buffing and it will look good, even though it is a little too tall.


----------



## kvtaco17

All hail the chosen tube! Nice work sir!


----------



## bundy

That looks so cool, very nice work. But how does it sound?


----------



## TrollDragon

Thanks guys, it doesn't sound yet as there is still the hookup to do and that tube I just plugged in for looks. I think it is a heptode & triode combined and I just liked the screen on it.


----------



## Artsi

I made an adapter only for octals. Two 6N8S (6SN7GT) as power and one 6N9S (6SL7GT) to drive them. I think this is my cutest adapter and sound is so good that i can highly recommend this kind of thing to anyone. No any kind of hum or additional noise. Even cheapest Russian tubes seem to sound flawless.


----------



## MIKELAP

trolldragon said:


> Just test fitting a new design for the B9A adapter. I still need to wire up and epoxy the socket, make the pins and solder the unit together.
> A little spit, polish, buffing and it will look good, even though it is a little too tall.


 
 Nice configuration .


----------



## MIKELAP

artsi said:


> I made an adapter only for octals. Two 6N8S (6SN7GT) as power and one 6N9S (6SL7GT) to drive them. I think this is my cutest adapter and sound is so good that i can highly recommend this kind of thing to anyone. No any kind of hum or additional noise. Even cheapest Russian tubes seem to sound flawless.


 
 Nice clean look love those tubes


----------



## mab1376

artsi said:


> I made an adapter only for octals. Two 6N8S (6SN7GT) as power and one 6N9S (6SL7GT) to drive them. I think this is my cutest adapter and sound is so good that i can highly recommend this kind of thing to anyone. No any kind of hum or additional noise. Even cheapest Russian tubes seem to sound flawless.


 
 I'm so jealous!
  
 Would you be willing to make one for my MK IV, if so PM me.
  
 You pretty much turned it into the MK 9 http://littledot.net/forum/viewtopic.php?f=9&t=2537&sid=26e07a6b5e4b72fccb7c2aae7f5df775


----------



## i luvmusic 2

I'am looking for a 7 pin socket saver.


----------



## Kestovitutus

mordy said:


> Hi I love music 2,
> 
> There is much less of a selection of power tubes than driver tubes. The best are the 6H30Pi-DR/6N30-DR  tubes that today run in the $200-$250 range/pair. An excellent and much less expensive alternative is the 6N6P-IR that cost under $35/pair. Don't bother to look for anything else.
> 
> All these tubes are made in Russia. With the fall of communism the quality went down. It is best to look for older tubes made before 1990 and preferably from the 70's and 80's. Count on a month to receive them (sometimes faster).


 

 Hi.

 I recently got my Little Dot MkIII and found this nice guide. I'm new to tube amps but I already have few pairs of tubes to replace the mismatch stock pair of 5654's I got. I was wondering how 6N6P compares to 6N6P-IR soundwise? Saw them at 28$ pair so I might upgrade. Also there is these 6E6P-DRY/DRU tubes.. I presume they can't be used on little dot?

 Thanks


----------



## gibosi

i luvmusic 2 said:


> I'am looking for a 7 pin socket saver.


 
  
 http://www.radiodaze.com/product/15450.aspx


----------



## mordy

Hi Kestovitutus,
  
 For a comparison of the different power tubes for the Little Dot please go to page 191 and read post #2860.
  
 I think 6 different power tubes are  being compared and the differences are explained.


----------



## mordy

Tried to understand what kind of tube the 6E6P-DRY/DRU is. Here are a link to specs but in Russian that google translate does not tackle. (Comments have been translated)
  
 Since this is another super quality DR tube it might merit investigation. One source selling them says that they can be wired for triode use.
  
 Would like to hear from the people who understand the specs if it is suitable for the Little Dot - thanks.
  
  
 http://translate.google.com/translate?hl=en&sl=ru&u=http://audio-db.info/AudioDB/BazaPraktiki/Usilenie/Lampy/Alfavit/6Je/6Je5P&prev=/search%3Fq%3D6E6P-DRY/DRU%2Bspecifications%26start%3D10%26client%3Dfirefox-a%26hs%3Dm1F%26sa%3DN%26rls%3Dorg.mozilla:en-USfficial%26biw%3D1024%26bih%3D480


----------



## mAurelius

At the risk of being redundant...I have looked through this thread and not found an answer, so I figured I would give it a shot and see if anyone has thoughts. 
 I have the Little Dot MK III and I'm currently using the Voshkod 6ZH1P-EV, which I really like overall (although to be honest I don't have much to compare it to). 
 My only complaint is there are a few ranges of treble where it sounds rather harsh to my ears, particularly with a few rock artists (for example an aggressive hi-hat can sound quite painful). 
 I'm wondering if you have a recommendation on tubes that are perhaps a little softer in the treble area? I was looking at the *Mullard M8161* ... any thoughts on that one?
 Thanks!


----------



## Artsi

mordy said:


> Tried to understand what kind of tube the 6E6P-DRY/DRU is. Here are a link to specs but in Russian that google translate does not tackle. (Comments have been translated)
> 
> 
> 
> ...



 


I am pretty sure that 6E5P and 6E6P are NOT compatible.


----------



## TrollDragon

Well the 12AX7 is junk, there is a channel missing. You give it a tap and the channel pops back in for a moment then cuts out again.
  
 Here is the test rig, I figured I better check it out before it gets armored all in shiny copper. 
	

	
	
		
		

		
			





 DIY B7G plugs from a piece of lexan cut to size so they will slip up inside a 1/2" coupler.
  
  

 Since the 12AX7 was junk I switched the wiring for this ECC85 and it works like a charm, treble sharp enough to shave with but it works. Considering it is an FM tuner tube I really don't think it has a decent audio quality.
  

 A closeup of the DIY plugs.
  


 Phillips MiniWatt ECC85 made in Holland, should be relabeled to "Mach 3 by Gillette" 
	

	
	
		
		

		
		
	


	



 I just need to find some 6DJ8's or Tesla E88CC's on the cheap...
  
 Well I've reached where you all were a few months back, if you all don't mind I'll just tag along at the back of the bus.


----------



## MIKELAP

trolldragon said:


> Well the 12AX7 is junk, there is a channel missing. You give it a tap and the channel pops back in for a moment then cuts out again.
> 
> Here is the test rig, I figured I better check it out before it gets armored all in shiny copper.
> 
> ...


 
 Built to last nice


----------



## mordy

Hi mAurelius,
  
  
  
 Buy a pair of EI 6HM5 tubes that do not require any modifications and use E95 setting. These tubes beat the other ones you mentioned  + you get a beautiful safe fireworks display every time you turn them on.
  
 Submit a best offer for $5 each and you get this pair for $10 with free shipping (takes about 3 weeks to the US).
  
 Read post #3545 on page 237.


----------



## mAurelius

mordy said:


> Hi mAurelius,
> 
> 
> 
> ...


 
  
 Well shoot, for 10 bucks it's worth a shot! The "fireworks display" sounds a little scary, but I do see a lot of other good comments on this thread about them. I'll give it a shot. How is the treble on these, would you say it's less "harsh" than some of the other tubes?


----------



## vic2vic

trolldragon said:


> Well the 12AX7 is junk, there is a channel missing. You give it a tap and the channel pops back in for a moment then cuts out again.
> 
> 
> 
> ...


 
  Maybe a stupid question (I'm a noob in soldering): is there a place on eBay where I can buy a bunch of these nice multicolored short copper wires ? So far I've found only "breadboard wires", but it seems they are thick (not strended) and probably not even copper ones. Need them at reasonable price with shipping to Europe. Thanks


----------



## mojorisin35

mordy said:


> Hi mAurelius,
> 
> 
> 
> ...




I agree wholeheartedly I have tried all the a+ tubes in this thread and these are the easiest and my current reference tube.


----------



## Audiofanboy

It's funny how looking at this mod without the copper parts, it strangely reminds me of my "flying 12AT7" experiment that sparked the whole thing lol! Looking forward to seeing the final version; meanwhile I'm still trying to find the best way to make some tamer adapters for each socket on the IV SE...
  
 Speaking of 12V tubes, I've put a few very nice 12AX7 up for sale, since I just can't afford to keep stashes and stashes of premium tubes...
  
http://www.head-fi.org/t/689111/telefunken-12ax7-ecc83-tubes-1-ribbed-plates-2-smooth-plates
  
 These are some of the best -actual- 12AX7/ECC83 you can get, and they really sound great on our amps. The EI especially have tremendous value, but the Telefunken tube lives up to its reputation.
  
 Back to ebay to shop some more now  .


----------



## gibosi

trolldragon said:


>


 
  
 What kind of socket are you using? And how are you connecting the wires to it?


----------



## mordy

Hi mA,
  
 The Yugo 6HM5 is a sweet tube and the treble is not harsh at all (again YMML - tubes react differently to different equipment) but definitively a big improvement over the Voskhods. Remember that the Voskhods take a very long time to burn in (110-120 hours) and they mellow.


----------



## MIKELAP

gibosi said:


> What kind of socket are you using? And how are you connecting the wires to it?


 
  

  
 Looks like bullet type connector but with heat shrinked  tubing. wires look to be bigger than gauge  22 maybe 16 gauge


----------



## TrollDragon

mikelap said:


> Built to last nice


 
  
 Thanks!
   
 Quote:


vic2vic said:


> Maybe a stupid question (I'm a noob in soldering): is there a place on eBay where I can buy a bunch of these nice multicolored short copper wires ? So far I've found only "breadboard wires", but it seems they are thick (not strended) and probably not even copper ones. Need them at reasonable price with shipping to Europe. Thanks


 
 A local hardware or automotive parts store is your best bet, the wire I used is all 22AWG with a pair of 18AWG since I ran out of 22... 
	

	
	
		
		

		
			




  


audiofanboy said:


> It's funny how looking at this mod without the copper parts, it strangely reminds me of my "flying 12AT7" experiment that sparked the whole thing lol! Looking forward to seeing the final version; meanwhile I'm still trying to find the best way to make some tamer adapters for each socket on the IV SE...
> 
> Speaking of 12V tubes, I've put a few very nice 12AX7 up for sale, since I just can't afford to keep stashes and stashes of premium tubes...
> 
> ...


 
  
 YOU are the reason we are all doing this Good Sir! 
	

	
	
		
		

		
		
	


	



 Inspiration was had from your "flying 12AT7" for sure. I just had to test before the copper clad when on.
  


gibosi said:


> What kind of socket are you using? And how are you connecting the wires to it?


 
 Salvaged from the PCB of an old console system.
 This is a picture of the 7 pin version which I do not have.

 These were made to plug into PCB holes and be soldered. I just put the wire between opening and soldered, a little heatshrink and it looks like plugs but it is not. These old sockets are cheap and flimsy as well so you have to be gentle with them.
  


mikelap said:


> Looks like bullet type connector but with heat shrinked  tubing. wires look to be bigger than gauge  22 maybe 16 gauge


 
  
 That is a great idea BUT the less non soldered connections you have in the chain the better all around it will be.
  
 I'm going to see if I can get the copper clad on it tonight and I'll post pic's if it works out well. Also looking forward to see what AFB comes up with for the MKIV.
  
 If I had access to a metal shop I'd place a 9 pin B9A chassis mount socket in the middle between all 4 tubes and bore a hole down through for the wires. Then a nice little finish on it and your done, just dont plug in the B7G's and B9A at the same time.


----------



## MIKELAP

trolldragon said:


> Thanks!
> A local hardware or automotive parts store is your best bet, the wire I used is all 22AWG with a pair of 18AWG since I ran out of 22...
> 
> 
> ...


 
 Thats it , i had enough i am going back to work .Just kidding ,just kidding. but damm would i like a lathe and a milling wright now.


----------



## TrollDragon

mikelap said:


> Thats it , i had enough i am going back to work .Just kidding ,just kidding. but damm would i like a lathe and a milling wright now.


I would be on your doorstep with my amp under my arm and we'd do it up proper!


----------



## hypnos1

FINALLY! - Have managed to get down to constructing my B9 to B7 adapter...those brown ceramic ones didn't really appeal (but they sure would have been a darned site easier!). So now I can enter dble triode land. YIPEE...except some of those prices seem to me somewhat OTT.
 Therefore will be starting with some Zaerix 6DJ8s; Phillips ECG 6922s (JAN); Voskhod 6N23Ps ('70s) and 6N2P - ERs, and a pair of RCA 6DJ8s - Made in Japan, except one does say so on the tube but the other has Holland on it, and they look absolutely identical. Perhaps I got lucky here...Japanese Amperex or Dutch? Can't wait to see how these perform especially...
  
 Anyway, can't resist showing the results of my blood, sweat and tears - not to mention rather fruity language! The tube atop is one of the V/Hod 6N2P-ERs, and what a beautifully made thing it is too...

  

  
 This one is wired for triode 1, the other will be for #2 - therefore periodic swapping of the tubes will keep all triodes happy. And me...
  
 Glad to say this first one works...just hope to God the second does also, as the insides are sealed with resin - so if at first I don't succeed, trying again is NOT an option! Apart from starting all over again from scratch with a new one - which fills me with dread!!
  
 Am I feeling lucky? I'll let you know...
  
 BFN folks.


----------



## Oskari

hypnos1 said:


> a pair of RCA 6DJ8s - Made in Japan, except one does say so on the tube but the other has Holland on it, and they look absolutely identical. Perhaps I got lucky here...Japanese Amperex or Dutch? Can't wait to see how these perform especially...


 
  
 The correct manufacturer names would be Matsush¡ta and Philips. That's assuming we can trust what's printed on the tubes, which we always can't. The Dutch-made tube should have an acid-etched code that identifies the factory.
  
 You never know who made a particular Zaerix-branded tube, until you know. They were rebranders and could have rebranded anything.


----------



## i luvmusic 2

gibosi said:


> http://www.radiodaze.com/product/15450.aspx


 
 THANKS but that place charge $35 for shipping.


----------



## MIKELAP

i luvmusic 2 said:


> THANKS but that place charge $35 for shipping.


 
 Its a mistake i just bought 4 vector sockets from them to Montreal shipping was $10.00 for 4  Vector sockets cost me $30.00 total


----------



## i luvmusic 2

mikelap said:


> Its a mistake i just bought 4 vector sockets from them to Montreal shipping was $10.00 for 4  Vector sockets cost me $30.00 total
> I


 
 I hope so i will try again and see.


----------



## vic2vic

hypnos1 said:


> FINALLY! - Have managed to get down to constructing my B9 to B7 adapter...those brown ceramic ones didn't really appeal (but they sure would have been a darned site easier!). So now I can enter dble triode land. YIPEE...except some of those prices seem to me somewhat OTT.
> Therefore will be starting with some Zaerix 6DJ8s; Phillips ECG 6922s (JAN); Voskhod 6N23Ps ('70s) and 6N2P - ERs, and a pair of RCA 6DJ8s - Made in Japan, except one does say so on the tube but the other has Holland on it, and they look absolutely identical. Perhaps I got lucky here...Japanese Amperex or Dutch? Can't wait to see how these perform especially...


 
  
 Before I make some nice fireworks out of my LD MK II+...is the wiring exactly the same for 6N23P - 6N2P - 6DJ8 tubes ? I'm planning to build an adapter from one B9A to 2x B7G.
 Thanks


----------



## gibosi

vic2vic said:


> Before I make some nice fireworks out of my LD MK II+...is the wiring exactly the same for 6N23P - 6N2P - 6DJ8 tubes ? I'm planning to build an adapter from one B9A to 2x B7G.
> Thanks


 
  
 Yes, the pin-out is identical for these tubes, so the same adapter will work for all three.


----------



## TrollDragon

Anyone have any tubes that send a "Ping" noise while warming up? One of the 6Ж5П's I have will emit this noise once or twice. Just wondering if it is the tube being a little microphonic and the glass heating up that causes the noise?

Not a big deal, just a unique sound.


----------



## Artsi

My amperex 6DJ8 keeps all kind of noises when warming up. reason must be A getter frame and other parts that move little bit when warming.


----------



## TrollDragon

Thanks Artsi, I figured it was something along those lines.


----------



## Audiofanboy

hypnos1 said:


> *This one is wired for triode 1, the other will be for #2* - therefore periodic swapping of the tubes will keep all triodes happy. And me...
> 
> Glad to say this first one works...just hope to God the second does also, as the insides are sealed with resin - so if at first I don't succeed, trying again is NOT an option! Apart from starting all over again from scratch with a new one - which fills me with dread!!
> 
> ...


 
  
 Lol, it's like you read my mind; I'm building my two adapters with the exact same plan in mind! Hopefully, a switch between triode sections every, say, 20-50 hours could save all four triodes from cathode poisoning (and from losing their rather high resell value) and make the "two double triodes with only one section used' solution more appealing and less wasteful.
  
 Glad your first adapter worked on you first try. I've had times in the past when I got too excited and drowned a freshly made DIY adapter in hot glue _before_ testing, and had a bad surprise a few minutes later, so now I'm extra careful about that...
  
 I'm trying to make adapters that are even a bit smaller and thinner than yours though, like no more than 1.25cm or 1/2" high and with with narrowed B9A sockets. I'll take a picture when I'm done -if I ever manage to be lol...


----------



## hypnos1

audiofanboy said:


> Lol, it's like you read my mind; I'm building my two adapters with the exact same plan in mind! Hopefully, a switch between triode sections every, say, 20-50 hours could save all four triodes from cathode poisoning (and from losing their rather high resell value) and make the "two double triodes with only one section used' solution more appealing and less wasteful.
> 
> Glad your first adapter worked on you first try. I've had times in the past when I got too excited and drowned a freshly made DIY adapter in hot glue _before_ testing, and had a bad surprise a few minutes later, so now I'm extra careful about that...
> 
> I'm trying to make adapters that are even a bit smaller and thinner than yours though, like no more than 1.25cm or 1/2" high and with with narrowed B9A sockets. I'll take a picture when I'm done -if I ever manage to be lol...


 
  
 You gonna make 'em even SMALLER? Ye Gods, AFB, you've got much nimbler fingers and better eyes than mine then... GOOD LUCK! Mind you, I was using B9As with gold  'pins' inside rather than terminals on the outer edge - I DEFY you to make a 1/2" one with the latter babies!! Look forward to seeing your final result...
  
 Would have loved to test the contraption before gluing, but was afraid of possible wire connection damage when trying to extricate the tiny tube/socket base from the LD before really securely attached to the body...catch 22?
  
 Early update so far...(ridiculously early for a Russian!), but with just 12 hours on and an Ei 6HM5 in the right channel, this 6N2P-ER is already showing amazing promise...a tad bright of course, and the extra (!) soundstage has vocals a bit less forward, but hey, with practically no burn-in yet and a not-too-mismatched (from the sound of it) tube as a mate, I am rather 'gobsmacked' to say the least...Added incentive to finish adapter number 2, and bodes really well for the other tubes...I suspect a possible divorce in the offing!!
  
  
 Hi vic2vic.
  
 Gibosi has kindly answered your question...yes, all the same...
  
 Hi Oskari.
  
 Thanks for your info...will be trying to find some hidden codes - SOMEwhere...


----------



## mordy

Hi all,
  
 Finally caught up slightly  and built two separate spider web style adapters for 12AX7 and 6DJ8. These tubes really are *MUCH* better than anything we tried before.
  
 One adapter was soldered by a friend, and the second I screwed together using the Vectors and a breadboard which turns out to be much easier.
  
 The 6AV6 tubes are supposed to be 1/2 of the 12AX7. I noticed that the 6AV6 tubes changed very much in character during burn-in (for the better) and took around 40-50 hours to reach full potential.
  
 As regards the 12A7 and 6DJ8 families, does anybody know how the long the burn in period is, and if they change a lot in sound during and after burn in? 
  
 Right now I am listening to a Dutch Amperex Tektronix 6DJ8 from 1975 with the A frame getter. Funny, in my 6AK5 odyssey I found the Amperex tubes to have the strongest bass. With the Amperex 6DJ8 the bass is striking and goes lower (sub woofer territory) than any tube I tried. Overall, an excellent tube with nothing to criticize and only to enjoy listening to.
  
 Artsi, I am just shaking my head in disbelief over what you accomplished with the octal tubes. To do what you are capable of is way beyond anything I can aspire to. I assume that bigger is better (heat dissipation?), but really, how does the sound of the octals compare to say the 6DJ8?
  
 Trolldragon, when you have perfected the flying tube adapter, please let me know so that I can order one. My own adapters are very fragile, and I am afraid to as much as breathe on them lest some little wire will get lose or break....
  
 Is less better? On a personal note, my receiver blew up, and I had it repaired for around $200. First I thought that I had crossed two speaker wires by accident when I moved a speaker. After carefully rewiring and going over all connections, I plugged in the receiver. Within a few minutes, poof, poof, and that sickening white acrid smoke again. Turns out that one speaker had shorted out internally and blew, and that is what caused the receiver to short out. Again.
  
 So I am stuck with my 1980's Sony receiver and two speakers instead of four. Meanwhile my two subwoofers are disconnected. Still, with the Amperex 6DJ8 the sound is quite nice.
  
 Oh well, less is at least livable....


----------



## TrollDragon

Hi mordy will do, I'll probably not play in the 6DJ8 game so I'll PM you about sending mine your way when I have it assembled and solid.


----------



## Audiofanboy

mordy said:


> Hi all,
> 
> Finally caught up slightly  and built two separate spider web style adapters for 12AX7 and 6DJ8. These tubes really are *MUCH* better than anything we tried before.
> 
> ...


 
  
 Shocking, right? Yeah, I'm definitely _not_ going back to pentodes/heptodes; it would feel like a punishment to do so lol...
  
 The 6DJ8 in particular are very very nice on headphones, but the 12AX7 (the Tele ones I have at least) seem to work very well for broader applications too, like through speakers. On headphones though, the OG are just miraculous! I just found two more early 60's USN-CEP Amperex 6922, so I'll have three different tubes to play with and compare to the OG soon.
  
 As far as burn-in goes, I wouldn't expect any dramatic change like some extreme tube types we've tried, just some basic bass tightening and de-muddiness by 10-12 hours, and a slightly more mature and focused sound by 20-50 hours. Those tubes are so good out of the box, you don't even think of doing a formal burn-in with them, you just listen to music!


----------



## Audiofanboy

hypnos1 said:


> You gonna make 'em even SMALLER? Ye Gods, AFB, you've got much nimbler fingers and better eyes than mine then... GOOD LUCK! Mind you, I was using B9As with gold  'pins' inside rather than terminals on the outer edge - I DEFY you to make a 1/2" one with the latter babies!! Look forward to seeing your final result...
> 
> Would have loved to test the contraption before gluing, but was afraid of possible wire connection damage when trying to extricate the tiny tube/socket base from the LD before really securely attached to the body...catch 22?


 
  
 OK, lol, I lied... Let's just say my goal is to remain below the inch limit in height, basically. 2.5cm or so _should_ be achievable. Maybe?


----------



## mordy

HI AFB,
  
 Agree with everything you say. I have a Sylvania 12AX7 that sound wonderful through what is left of my speakers.
  
 I did notice a bass tightening as well, but as you say, these tubes sound great just out of the box, and I do not feel the need to wait for the grueling burn in period to finish to enjoy the tubes.
  
 TrollDragon: IMHO you should try the 6DJ8 tube - with a little patience you can buy an Amperex for less than $10. The wiring entails only a few changes.


----------



## gibosi

trolldragon said:


> Hi mordy will do, I'll probably not play in the 6DJ8 game ......


 
  
 I hope you will give these tubes a chance. Otherwise, you will be missing out on the best tubes I have ever rolled in my LD!
  
 Yes, they can be expensive, but if you are patient, you can find some good deals. As Mordy notes, Amperex are plentiful and can often be found for as little as $10/each. The Teslas are also excellent and also can be found for as little as $10/each. And every so often, a great deal pops up. In today's mail I received a Valvo E88CC, with gold pins, manufactured in the Hamburg factory, which cost me only $18. And it sounds great!


----------



## gibosi

mordy said:


> Is less better? On a personal note, my receiver blew up, and I had it repaired for around $200. First I thought that I had crossed two speaker wires by accident when I moved a speaker. After carefully rewiring and going over all connections, I plugged in the receiver. Within a few minutes, poof, poof, and that sickening white acrid smoke again. Turns out that one speaker had shorted out internally and blew, and that is what caused the receiver to short out. Again.
> 
> So I am stuck with my 1980's Sony receiver and two speakers instead of four. Meanwhile my two subwoofers are disconnected. Still, with the Amperex 6DJ8 the sound is quite nice.


 
  
 Bummer! 
  
 But you might try connecting your one good subwoofer. There is virtually no "stereo" at these very low frequencies, so you won't really be missing anything by having only one subwoofer.


----------



## Artsi

mordy said:


> Artsi, I am just shaking my head in disbelief over what you accomplished with the octal tubes. To do what you are capable of is way beyond anything I can aspire to. I assume that bigger is better (heat dissipation?), but really, how does the sound of the octals compare to say the 6DJ8?
> Oh well, less is at least livable....


 
 I think that this octals-adapter is so lovely, that i'm not going back to any miniatyre tubes. These tubes do not get very hot and amplifier does not get warm at all. Powertubes have only 0.6A heaters and driver 0.3A. 
  
 I have been studying hard about how people have reviewed different octal tubes and how they compare each other. Most say that these cheap russian 6N9S and 6N8S sound crappy. Mine are not even vintage, driver 6N9S is from -88 and from powertubes other 6N8S is Sovtek -80 and the other is normal russian 6N8S -82. I have Sovtek 6SL7GT (same 6N9S still), but it is defective. It starts to keep little weird changing hum in left channel after about 5minutes of use. I have been thinking that if these sound crappy, then how insanely good could better tubes sound. 
	

	
	
		
		

		
			




  
 So i ordered 2 different 6SU7GTY (premium 6SL7GT with matched triodes and 10000h life), 4 different 6SL7GT, one 5691 (premium 6SL7GT with 0.6A heater), 2 5692 (premium powertube 6SN7GT) and 2 6SN7GT as power. Hope i get these next week and in one piece.


----------



## hypnos1

Eureka! B9 to B7 adapter number 2 is finished...and actually WORKS - phew! The LD doesn't look too bad for it, either, thank goodness.
  
 With the second Voskhod 6N2P-ER in place, I have to say I am VERY impressed - my system, at least, is falling in love with them already. Soundstage? - there's just one word sums it up : 5.1 surround! OK, more than one...Another would be EXCITING. Although new-in impressions are not to be trusted (notwithstanding previous posts re less need for burn-in), I decided to pop in the Japanese (Amperex) 6DJ8s - one with 'Holland' on it - and what a difference : laid-back as opposed to WOW-exciting. Nowhere near the same soundstage and 'airiness', nor 'sparkly' treble as the Voskhods. Even if one or both of the RCAs were made by Matsu****a, they are definitely from Amperex machinery and one would assume that they would perform fairly closely to the Holland ones...perhaps I am assuming too much? If they ARE a close second, all I can say is they have a long way to go to outperform the V/hods - I suspect there is more chance of the (at present) weaker mids of the latter developing as the treble tones down, than the RCAs livening up to any great degree...ie somewhat disappointed in this regard. Still, it's early days yet, so I must be patient and see what the other 6DJ8s and 6922s deliver...not to mention the Tesla PCC88s yet to arrive...
  
 But back to the Voskhods, perhaps one shouldn't be TOO surprised as JAC Music rank the 6N2P as one of the top 10 'ECC83s' you can get, and as I have been lucky enough to get the special ER version this could well explain the current situation. I do believe Audiofanboy mentioned something about the 12AX7 specs matching our LDs better than the ECC88s, so perhaps this is also helping...I do also like the much higher gain from these babies. Ah well, time will tell. Whatever, these double triodes certainly are the business. And well worth the effort in making those adapters...viz : the finished result...


----------



## gibosi

hypnos1 said:


> With the second Voskhod 6N2P-ER in place, I have to say I am VERY impressed - my system, at least, is falling in love with them already. Soundstage? - there's just one word sums it up : 5.1 surround! OK, more than one...Another would be EXCITING. Although new-in impressions are not to be trusted (notwithstanding previous posts re less need for burn-in), I decided to pop in the Japanese (Amperex) 6DJ8s - one with 'Holland' on it - and what a difference : laid-back as opposed to WOW-exciting. Nowhere near the same soundstage and 'airiness', nor 'sparkly' treble as the Voskhods. Even if one or both of the RCAs were made by Matsu****a, they are definitely from Amperex machinery and one would assume that they would perform fairly closely to the Holland ones...perhaps I am assuming too much? If they ARE a close second, all I can say is they have a long way to go to outperform the V/hods - I suspect there is more chance of the (at present) weaker mids of the latter developing as the treble tones down, than the RCAs livening up to any great degree...ie somewhat disappointed in this regard. Still, it's early days yet, so I must be patient and see what the other 6DJ8s and 6922s deliver...not to mention the Tesla PCC88s yet to arrive...


 
  
 Welcome to double triode land! 
  
 I found the Voskhod 6N2P-EV to be less bright than Holland-made Amperex 6DJ8, with a strong, but somewhat loose bass. And this was after 20 hours of use. But you have a pair of -ERs, not -EVs, so yours may well sound different. Further, I haven't heard any of the Japanese-manufactured 6DJ8s, so I have no idea how they might compare to Holland-made Amperex. Looking forward to learning how your Voskhods compare to your future acquisitions. Currently, my favorite Soviet tube is a 1979 Voskhod 6N23P.
  
 I had a nice pair of Tesla PCC88 and thought that they were very good sounding tubes. However, their build-quality was lacking. Both of the Teslas broke as a result of bending and then re-straightening the pins. But since you won't be mangling your tubes, you should be good. lol


----------



## Oskari

hypnos1 said:


> ... I decided to pop in the Japanese (Amperex) 6DJ8s - one with 'Holland' on it ... Even if one or both of the RCAs were made by Matsu****a, they are definitely from Amperex machinery ...


 
  
 Please, let's try to call things by their proper names. It was not Amperex machinery. Even the machinery of the Amperex tube plant in Hicksville, New York was supplied by Philips, of which Amperex was a US subsidiary.


----------



## TrollDragon

Hey mordy!
  
 You have a MK III Yes?
 So I am sure that the pipe adapter will fit can I get you to measure the distance between the two red lines.

 Basically it is from the left edge of the case hole to the left edge of the next case hole, not the gold rings.
 Or you can measure between the exact center of one tube socket to the center of the other. I am not sure if the MK III is the same width as the MK IV.
 ----
 This will be a one-off "Polished Copper Tube Adapter", there is just way too much labor involved with only a Dremel and no other shop tools.
 Also do you want it wired for 12AX7 or 6DJ8? Once finished it cannot be changed.
  
 Thanks for all the recommends guys but I am not going to play, I have a difficult time chasing $5 tubes let alone $10-$20 ones, it's just not in the cards right now, possibly down the road I'll get involved with some.


----------



## gibosi

trolldragon said:


> Hey mordy!
> 
> You have a MK III Yes?
> So I am sure that the pipe adapter will fit can I get you to measure the distance between the two red lines.
> ...


 
  
 Also, you will want to make sure the driver tubes are oriented the same way. My assumption is that the orientation on the III and IV is the same, that is both driver tubes "face" the same direction. However, on my 1+, one driver tube "faces" left and the other "faces" right.


----------



## TrollDragon

gibosi said:


> Also, you will want to make sure the driver tubes are oriented the same way. My assumption is that the orientation on the III and IV is the same, that is both driver tubes "face" the same direction. However, on my 1+, one driver tube "faces" left and the other "faces" right.


 

 Great point!
 So a top down picture of the sockets without tubes would be good as well.
 Both of the adapter bottoms can turn a little in each direction to allow for easy alignment.


----------



## MIKELAP

trolldragon said:


> Hey mordy!
> 
> You have a MK III Yes?
> So I am sure that the pipe adapter will fit can I get you to measure the distance between the two red lines.
> ...


 
  
 I measured with a vernier and from  center to center it measures 1.570 or 40 m.m.(1.575) i measured this from holes in chassis not the rings so it should be the same as littledot 4 but sockets arent exactly in middle read next post


----------



## MIKELAP

If theres a possibility to make like this the copper elboy on right channel is left loose so you can ajust the center distance by ajusting the lenght of it because not doing this is almost impossible to get the center distance  perfectly i think


----------



## TrollDragon

mikelap said:


> I measured with a vernier and from  center to center it measures 1.570 or 40 m.m.(1.575) i measured this from holes in chassis not the rings so it should be the same as littledot 4 but sockets arent exactly in middle read next post


 
 Thanks MIKELAP!
 When did you say you were getting your lathe and vertical miller? 
	

	
	
		
		

		
			




  
 The MKIV's sockets are on 50mm center's so I will most likely have to trim down the elbows as well. There is not really any easy way to have the width adjustable that I can see.

  
 The bottom pieces turn so socket oreientation is not a problem and the width is not much bigger than a tube, so I don't think that the socket position in the hole should be an issue either.
  
 If I can't get the width right without making it look like the dogs dinner then it just won't be done.


----------



## Artsi

Some glow of the octals.


----------



## MIKELAP

trolldragon said:


> Thanks MIKELAP!
> When did you say you were getting your lathe and vertical miller?
> 
> 
> ...


 
 For the socket to socket distance i guess best thing is to install the sockets themselves in LD if you are using sockets because they fit perfectly in copper elboy and just install copper body over the sockets epoxy and let dry installed on littledot .This is how i want to do the 7pin socket and possibly use shrink tubing or something like the wrapping they used on the adaptors so its a durable adaptor.


----------



## mab1376

artsi said:


> Some glow of the octals.


 
 so jealous!


----------



## TrollDragon

mikelap said:


> For the socket to socket distance i guess best thing is to install the sockets themselves in LD if you are using sockets because they fit perfectly in copper elboy and just install copper body over the sockets epoxy and let dry installed on littledot .This is how i want to do the 7pin socket and possibly use shrink tubing or something like the wrapping they used on the adaptors so its a durable adaptor.


 
 Very Nice!
 That will work great and don't forget to round off the ends of those wires.


----------



## hypnos1

oskari said:


> Please, let's try to call things by their proper names. It was not Amperex machinery. Even the machinery of the Amperex tube plant in Hicksville, New York was supplied by Philips, of which Amperex was a US subsidiary.


 
  
 Oops, sorry Oskari, and anyone else whose sensibilities may have been adversely affected by my less-than-perfect terminology. I bow to your greater knowledge in these matters...
  
 In mitigation, I understood that the machinery _that made_ 'Holland Amperex' (as with Siemens tubes) was shipped out to Japan and that, my neglect to put 'Amperex machinery' in parentheses notwithstanding, the actual _meaning_ would generally be understood . Ah well, can't win 'em all I suppose...will try to do better...


----------



## TrollDragon




----------



## hypnos1

gibosi said:


> Welcome to double triode land!
> 
> I found the Voskhod 6N2P-EV to be less bright than Holland-made Amperex 6DJ8, with a strong, but somewhat loose bass. And this was after 20 hours of use. But you have a pair of -ERs, not -EVs, so yours may well sound different. Further, I haven't heard any of the Japanese-manufactured 6DJ8s, so I have no idea how they might compare to Holland-made Amperex. Looking forward to learning how your Voskhods compare to your future acquisitions. Currently, my favorite Soviet tube is a 1979 Voskhod 6N23P.
> 
> I had a nice pair of Tesla PCC88 and thought that they were very good sounding tubes. However, their build-quality was lacking. Both of the Teslas broke as a result of bending and then re-straightening the pins. But since you won't be mangling your tubes, you should be good. lol


 
  
 Hi Gibosi.
  
 Thanks for the warm welcome...glad I've finally discovered what you have all been eulogising about. The wait, not to mention blood, sweat and tears has been well worth it. And not having to bend any pins - with the potential for some seriously frustrating (not to mention expensive) damage - certainly is a godsend. As is the ability to make sure all the triodes get regular use.
  
 How interesting that your 6N2P-EV was _less_ bright than the Amperex. My ERs need to tone down a fair bit as yet, so yes, there must be quite a difference between the two tubes. It will be very interesting to see how my '70s 6N23Ps compare...there just aren't enough hours in the day, or days in the week lol
  
 My Japanese 6DJ8 (Amperex _versions_) have now, quite surprisingly, developed MORE in the treble arena ...in the past my tubes have only ever gone in the opposite direction...strange...
 And I swear the bass has retracted a little after 10 hours - probably has tightened, but _appears _less. Perhaps this is allowing more treble frequencies to come through? Whatever, they are sounding much more interesting already. Can't wait to pop the Voskhods back in, to compare anew.
  
 So the Teslas might be a good find? Certainly hope so...sorry about yours. I do hope you don't lose any more of your tubes...


----------



## hypnos1

trolldragon said:


>


 
  
 Careful now, TD!!!


----------



## TrollDragon

hypnos1 said:


> Careful now, TD!!!


 
 All in good fun!


----------



## Oskari

hypnos1 said:


> Oops, sorry Oskari, and anyone else whose sensibilities may have been adversely affected by my less-than-perfect terminology. I bow to your greater knowledge in these matters...


 
  
 Thanks for taking it personally. That's how it was meant. Obviously.


----------



## hypnos1

oskari said:


> Thanks for taking it personally. That's how it was meant. Obviously.


 
  
 Oh dear, oh dear...the beauty (and success) of this thread for a long time now has been the generosity of spirit shown by all, no matter w_hat_ sort of faux-pas made by any member, whether newbie or veteran. I sincerely hope this wonderful tradition is not in jeopardy. Obviously.


----------



## Audiofanboy

Speaking of beauty, I think I just found the way I can make smaller (lower and skinnier) adapters.
  
 Very simply: I broke two 9 pins ceramic sockets with a hammer and kept the 18 resulting metal holes+soldering tabs. That obviously -wait no, wrong word lol- definitely wasn't my original intention, but half way through my trial, I saw the light.
  
 Using just the metal holes+tabs, I should able to make some fairly compact adapters which I'll just need to drown in hot glue and hide in apiece of copper tubing; no cumbersome ceramic parts or unflexible sockets to deal with. I'll just need to use a B9A tube to hold the metal holes+tabs in place while I solder them to the B7A "base" so that the whole structure stays somewhat straight. This way, I don't even need to bother with 9 tabs on top and 7 pins on the bottom part of the adapter, I can just use the 5 tabs and pins I need and have a less crowded adapter; _theoretically_...
  
 Work in progress, actually work not started...


----------



## Oskari

hypnos1 said:


> Oh dear, oh dear...the beauty (and success) of this thread for a long time now has been the generosity of spirit shown by all, no matter w_hat_ sort of faux-pas made by any member, whether newbie or veteran. I sincerely hope this wonderful tradition is not in jeopardy. Obviously.


 
  
 In the interest of making amends, I offer you another piece of my greater knowledge, as you so eloquently put it. Matsush¡ta was making tubes using Philips technology long before Philips ceased tube production in Europe. What do you make of that?


----------



## mordy

Hi Oskari,
  
 It was a business relationship where Matsushiita got technology from Phillips, and in exchange Matsushiita/National offered Phillips business and organizational advice.


----------



## MIKELAP

trolldragon said:


>


----------



## mordy

This is the Voskhod symbol - no fire.


----------



## MIKELAP

mordy said:


> This is the Voskhod symbol - no fire.


 
 That is correct mordy for $200.00 lol


----------



## Artsi

Here is connections for octal 6SL7GT as driver. It is pretty simple. No need to worry shield wirings.


----------



## hypnos1

oskari said:


> In the interest of making amends, I offer you another piece of my greater knowledge, as you so eloquently put it. Matsush¡ta was making tubes using Philips technology long before Philips ceased tube production in Europe. What do you make of that?


 
  
 Yo, Oskari, these things are sent to confuse/try us tube-rollers, of this I am certain!
 My RCAs have serial numbers 7643 &7504, with seams atop the tubes - safe to assume "Amperex" _version_?


----------



## gibosi

A Tung-Sol 6SL7GT arrived in today's mail. And it is BIG! lol
  
 Compared to the 6DJ8-type tubes, these are not all that expensive. This tube cost me $16.00. 
  

  
 Also, a few days ago, I received a 6SL7 to 9-pin adapter. A Sylvania 5751/12AX7 gives you some idea of the size of this tube plus adapter....
  

  
 I configured my breadboard 9-pin socket for 12AX7 and turned it on!
  

  
 And it sounds good! 
  
 In addition to this 6SL7, I have three 5751/12AX7: Tung-Sol, GE and Sylvania, so will be spending some time with these four tubes over the next several days


----------



## Artsi

gibosi said:


> A Tung-Sol 6SL7GT arrived in today's mail. And it is BIG! lol


 
 I'm glad that someone else is listening octal too.
  
 I have been listening octals intensively (yes these crappy russian ones). And played skyrim many hours with these too... I'm very sorry to say this, but i think going to octals from miniatyres is same thing as it was going to 12AX7 and 6DJ8 from B7G tubes.
  
 Octals have more dynamics, better control of everything, better instrument separation and details. These just have more power to do things right. And yet still i have only crappiest tubes of octals. I tried little 6N6P-IR's with the best of my 7pin miniatyres and i really wonder how bad they could sound after octals. They sound flat, soft and dull. 
	

	
	
		
		

		
		
	


	



  
 I'm waiting really anxious for those better tubes.


----------



## Oskari

hypnos1 said:


> My RCAs have serial numbers 7643 &7504, with seams atop the tubes - safe to assume "Amperex" _version_?


 
  
 The seams and the shape of the tip pretty much tell the story. See photo below.
  
 Those numbers are YYWW date codes. I suppose it's the date of the RCA silk-screening.
  


audiofanboy said:


>


----------



## Oskari

mordy said:


> It was a business relationship where Matsushiita got technology from Phillips, and in exchange Matsushiita/National offered Phillips business and organizational advice.


 
  
 Yeah, the technology transfer didn't happen by Philips dumping its old disused machinery to Matsush¡ta when getting out of the receiving tube business.


----------



## gibosi

artsi said:


> I'm glad that someone else is listening octal too.
> 
> I have been listening octals intensively (yes these crappy russian ones). And played skyrim many hours with these too... I'm very sorry to say this, but i think going to octals from miniatyres is same thing as it was going to 12AX7 and 6DJ8 from B7G tubes.
> 
> Octals have more dynamics, better control of everything, better instrument separation and details. These just have more power to do things right. And yet still i have only crappiest tubes of octals. I tried little 6N6P-IR's with the best of my 7pin miniatyres and i really wonder how bad they could sound after octals. They sound flat, soft and dull.


 
  
 Well, I would not go so far as to say that this Tung-Sol 6SL7 is better than a 6922/E88CC, but it is first-class. I am listening to Holly Cole's Night (Amazon), and her voice is deliciously sultry. I would say that this tube sounds something like a Mullard 6DJ8, quite warm, a clean, well-defined top-end, and a nice sense of air, but not as much treble presence as the US Amperex 6922.
  
 I encourage those of you who are able to roll 12AX7 tubes to try one of these. I think you will be very pleasantly surprised. 
  
 Edit: I purchased the octal to 9-pin adapter here:
 http://www.ebay.com/itm/320659633166?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649


----------



## Audiofanboy

gibosi said:


> Well, I would not go so far as to say that this Tung-Sol 6SL7 is better than a 6922/E88CC, but it is first-class. I am listening to Holly Cole's Night (Amazon), and her voice is deliciously sultry. I would say that this tube sounds something like a Mullard 6DJ8, quite warm, a clean, well-defined top-end, and a nice sense of air, but not as much treble presence as the US Amperex 6922.
> 
> I encourage those of you who are able to roll 12AX7 tubes to try one of these. I think you will be very pleasantly surprised.


 
  
 Thank you gibosi! Please keep claiming the superiority of 6DJ8 tubes and keep trying to convince me to _not_ try yet another whole family -let alone a whole new socket type- of tubes, my wallet might just give out if I do lol!
  
 Jokes aside, I'm inclined to believe that the best of the late 50s and 60s miniature types should at least be solid rivals for the -comparably- old world octals; at least I'd like to think so...
  
 Speaking of god tier double triodes, I finally got my US made Amperex USN-CEP 6922 tube (I have two more coming, one "USN" made in '62 and another USN-CEP made in 65-08) made in 64-52 and datecoded *4J just like gibosi's. Unlike the vision of New York in the winter of '61 in the latest Coen brothers' movie, this tube look like the best to come out of a NY factory for Xmas of '64. Gold pins, extra solid and rugged construction, this tube would make you wish you were actually in the Navy tuning radios in the 60s or something, just to get to try some nice tubes lol.
  
 Of course, it sounds absolutely fantastic, but you already knew that right? Detail, holographic musicians, transparent as air, balanced, punchy as can be: this tube is a riot to itself! Still, while I gave it the obvious upper hand on the Orange Globes in the first 20 minutes of listen, I have to admit that after an hour or two, this tube made me realize just how great and musical the OGs also are.
  
 While the USN-CEP might get a 9/10 or more on a hypothetical scale (with 10 being the legendary unobtainable tubes), the OGs would critically get a 8.9/10, so ever so slightly below but so close you wouldn't know otherwise. But on a subjective level, the OG have this warm yet transparent yet musical yet detailed characteristic to them that makes them hard to forget. As a tradeoff, the US 6922 seem like more serious tubes with punchier bass and a -slightly- drier midrange. Treble, while different is great in both cases. Actually, I think I've only just realized the meaning of the word "sweet" used to describe treble, comparing these two tubes. The OG treble is definitely sweet, it just has a delicious quality to it that makes you grin; the USN 6922 treble is more SS-like and serious sounding; detail is about the same in both case (8.9 and 9/10, or whatever). Bourbon & ginger ale or a chilled premium Chablis, which should I choose???
  
 So, no, the OG isn't going anywhere yet, and yes, you _need_ to try one of the best Amp'ex tubes out of each Holland and the US. They're just _that_ good! Again, I'm not even rolling tubes anymore, I'm just listening to music -at long last!


----------



## gibosi

As good as the US-Amperex 6922 is, I have also noticed that it lacks some of the sweetness of the BugleBoys, and I have been thinking that I would like to pick up a pair of Holland-Amperex 6922. Perhaps they might be just a little sweeter? I do feel quite certain, after spending some quality time with my Hamburg-Valvo 6922, that I am not interested in further exploring the Telefunken / Siemens end of the "European Sound Continuum"...  lol  
  
 However, I am in no hurry, as the US-Amperex is by far the best tube I have. and eventually, a good deal on a Holland tube will pop up. But I did find a good deal on a La Radiotechnique 6922/E88CC, made in Suresnes, France, with the factory code F. From what I have read, this tube could be quite nice....


----------



## TrollDragon

Is the 6SL7GT a good driver to start with?


----------



## gibosi

trolldragon said:


> Is the 6SL7GT a good driver to start with?


 
  
 I'm not sure what you mean by "start with". Where are you going?   
  
 The Tung-Sol 6SL7GT I have is not bad. However it is quite bassy and warm, and lacking in details, transparency and sound stage. Even so, its actually quite fun to listen to and it was cheap. I bought it primarily to see if I could actually use a 6SL7 in the LD.
  
 From what I have read, one of the best of this breed is the Tung-Sol JAN CTL 6SU7GTY with black glass, black round plates and a brown base. The 6SU7 is a premium version of the 6SL7. Unfortunately, while not as expensive as the premium 6DJ8, these are not cheap. So if I decide to get another, this is what I will try to find... at a good price....


----------



## Sony Slave

Does anyone know where I can buy a pair of socket adapters for the little dot 1+ for my Sylvania 6AQ6s? 
  
 I've seen 7,8, and 9 pin adapters all over ebay, but I really don't know which ones to purchase.


----------



## MIKELAP

Well just checked on those tung sol 6SU7GTY  holy moly were far from our$4.00 tubes but there so nice thats why i like the littledot MK9 with those big tubes and they are cheap 6080 /6AS7GA power tubes go from $10.00 each and theres tons of them


----------



## SwanSong

For the little dot 1+ which of these would you recommend for jazz with the HE-500 phones:
*Voshkod 6ZH1P-EV*
*MULLARD CV4014 / 6064 / M8083 / EF91 TUBES - SQUARE GETTER - RARE - MILSPEC #2*
*Mullard Gt Britain EF92 CV131 6CQ6 W77*
*Mullard M8161 / CV4015 tube, Horseshoe-gett**er*
  
*The **Voshkod** is my favorite for my tube dac over the Amperex white label, Bugle Boy and Telefunken *
  
 Any comments on proposed setup appreciated if I should consider othe options?????


----------



## mordy

Hi Gibosi,
  
 Thanks for your tip on the adapter for octal tubes - ordered one.
  
 While I wait for it to arrive I will have time to shop for 6SL7 tubes. I notice that Little Dot MK9 uses a 6N9P as a driver (I assume that it is Chinese made) which apparently is a 6SL7 equivalent.
  
 The are Russian tubes as well, 6H9C and 6N9S. Do you have any knowledge of Chinese and Russian 6SL7 type tubes?
  
 Also came across a huge list of Russian tube factories by location and symbols. Google translate will help in translating this list or individual entries on the list.
  
  
 http://istok2.com/factories/


----------



## Artsi

trolldragon said:


> Is the 6SL7GT a good driver to start with?


 
 Look no further, this is the one to start with!
http://diy-tubes.com/6n9s-6sl7-nos-nib.html
  
 Remember to change your powertubes to 6N8S too to get perfect match. 
	

	
	
		
		

		
			




  
 I personally think that even these 80's 6N9S tubes must be better than mediocre 6SL7GT.
http://kuvaton.com/k/YNkj.jpg


----------



## Artsi

sony slave said:


> Does anyone know where I can buy a pair of socket adapters for the little dot 1+ for my Sylvania 6AQ6s?
> 
> I've seen 7,8, and 9 pin adapters all over ebay, but I really don't know which ones to purchase.


 
 Why do you need adapter, what for?! Look help from here:
http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/1140#post_9392055
  
 Cut pins 5&6 and put your amp to EF91/92 state.


----------



## gibosi

sony slave said:


> Does anyone know where I can buy a pair of socket adapters for the little dot 1+ for my Sylvania 6AQ6s?
> 
> I've seen 7,8, and 9 pin adapters all over ebay, but I really don't know which ones to purchase.


 
  
 The 6AQ6 is a Double Diode-Triode. I have no idea how to use this tube in a Little Dot..... 
  
 Edit:  Oh... 6AQ6, 6AT6 and 6AV6.... It is late...  I am not thinking clearly.. lol... I need to sleep... but yes, just cut off pins 5 and 6 and use the EF92 setting and you are good to go... cheers!


----------



## TrollDragon

Here is the finished "Tower of Power" as MIKELAP calls it, just some spit, steel wool and polish left to do. I decided to use an octal socket so an octal tube could be plugged in or B9A tubes could be used with a 8 Pin plug and 9 pin socket.
  
 Sorry @mordy I won't be building any more of these as the functionality of this one is a little fiddly to get lined up and plugged in and I would not feel good sending it to you or anyone else.
 So let the Games Begin!

  

  
 Installed with lights on then off.

  

  
 Well that is the Tower of Power... Now i just need one of those CCCP 6H9C from Reflektor Plant that @Artsi linked, I'll have to pass on the power tubes till I can figure out a way to adapt them. Thanks Artsi!
  
 I played Opeth's "Blackwater Park" and "Watershed" while composing this to test the adapter and I still find the treble too sharp on the ECC85.

 Watershed has some great acoustic work, will be nice to hear it through a good tube!


----------



## Artsi

> Well that is the Tower of Power... Now i just need one of those CCCP 6H9C from Reflektor Plant that @Artsi linked, I'll have to pass on the power tubes till I can figure out a way to adapt them. Thanks Artsi!


 
 I have one extra 6N9S, but sending it to usa costs at least 7.5EUR and is slow. You can get those cheap tubes from usa easier and faster. For powertubes you could make straight coppertube-adapter separately for both channels. It should be easier than with those angled pipes. I think you know how wires have to be connected from B9A to Octal?


----------



## Sony Slave

gibosi said:


> The 6AQ6 is a Double Diode-Triode. I have no idea how to use this tube in a Little Dot.....
> 
> Edit:  Oh... 6AQ6, 6AT6 and 6AV6.... It is late...  I am not thinking clearly.. lol... I need to sleep... but yes, just cut off pins 5 and 6 and use the EF92 setting and you are good to go... cheers!


 
 Oh ok, thanks! Will do.


----------



## Sony Slave

Is this a good deal for the Orange Globe tubes, or is this too good to be true? A potential rip off?
  
http://www.ebay.com/itm/Pair-Holland-Amperex-Orange-Globe-6DJ8-ECC88-tubes-Tested-76-71-72-76-/181228837147


----------



## Sony Slave

audiofanboy said:


> Thank you gibosi! Please keep claiming the superiority of 6DJ8 tubes ......


 
 Hey Audiofanboy, what do I need to do, in order to run the 6DJ8 tubes correctly for the little dot 1+.


----------



## TrollDragon

artsi said:


> I have one extra 6N9S, but sending it to usa costs at least 7.5EUR and is slow. You can get those cheap tubes from usa easier and faster. For powertubes you could make straight coppertube-adapter separately for both channels. It should be easier than with those angled pipes. I think you know how wires have to be connected from B9A to Octal?


Thanks much for the offer Artsi but I will probably grab them from the site you listed when I get some spare cash. Yes the curved pipes are a PiTA to work with and straight up from a B9A to Octal socket will be a piece of cake! Your MK II make rigging this stuff so much easier with nothing in the way of the sockets. Much Fun to be had for sure, glad I didn't pick up a Schiit amp as I would be chased out of town hanging pipe from it.


----------



## gibosi

sony slave said:


> Is this a good deal for the Orange Globe tubes, or is this too good to be true? A potential rip off?
> 
> http://www.ebay.com/itm/Pair-Holland-Amperex-Orange-Globe-6DJ8-ECC88-tubes-Tested-76-71-72-76-/181228837147


 
  
 It's not a bad deal. However, notice the tested numbers in the heading:
  
 "Pair Holland Amperex Orange Globe 6DJ8 ECC88 tubes (Tested @ 76/71, 72/76)"
  
 A new tube should test at about 100. Anything less than 50 is shaky. So one could say that these tubes have about half of their useful life left, and if you use them regularly, you might have to get a new pair in a year or so....
  
 Also, these do not have a halo getter. They have a solid dimpled getter. Generally, the earlier halo getters are considered the best. But still, for $30, I think they would be very nice "starter tubes."


----------



## gibosi

5751/12AX7
  
 First, I want to point you to Joe's Tube Lore:
  
 http://www.audioasylum.com/scripts/d.pl?audio/faq/joes-tubes.html
  
 I have found his observations regarding 12AX7 and 6DJ8 to be largely spot on.
  
 So, I took his advice and bought a few 5751, which are premium versions of the 12AX7.
  
 Tung-Sol
  

  
 As Joe points out, this is a very nice tube, but it isn't as focused as the others. Instrument location is harder to discern.  It lacks the etched 3-D holographic presentation of the GE and Sylvania.
  
 ~~~~~~~~~~~~~~~~~~
 GE Black Plate
  

  
 This is probably the best buy: Transparent, micro details and a 3-D stage. This tube is equal to a good 6DJ8. However, the Sylvania is better. 
  
 ~~~~~~~~~~~~~~~~~~~~
 Sylvania Black Plate
  

  
 As Joe points out, mid range - especially female vocals - are to die for, along with transparency, micro details, 3-D stage, black-black quiet, it has it all. And frankly, the mid range on this tube is superior to my US-Amperex 6922. Of course, I'm still on my honeymoon with this tube lol. After more listening, I may well change my mind, but currently this is my favorite tube.
  
 And boy did I get lucky! I bought this one for $25. While nowhere near as expensive as the premium 6DJ8s, a single tube typically goes for a minimum of $60. As the lettering and graphics are completely gone, I suspect that many would-be buyers were skeptical that it really was a Sylvania. These and the GE black plates look extremely similar, except for some detailed metal work below the third mica. However, for me, the letter "E" below 5751 was the key. I remember seeing this pair below on eBay, so I did not hesitate.


----------



## Sony Slave

I put in the Sylvania 6AQ6 tubes and heard loud humming noise as I was playing my music. I have it on EF92 mode and I cut off pins 5 and 6 as well. I'll show you guys pics in a couple of minutes....
  
 What could it be?


Spoiler: Warning: Spoiler!



Stupidity?


----------



## gibosi

sony slave said:


> I put in the Sylvania 6AQ6 tubes and heard loud humming noise as I was playing my music. I have it on EF92 mode and I cut off pins 5 and 6 as well. I'll show you guys pics in a couple of minutes....


 
  
 It is not uncommon for tubes to buzz and hum when they are new. Typically, after 10 to 20 hours of use they quiet down. If they do not improve, you may want to consider requesting new tubes or money back from the vendor.


----------



## Sony Slave

gibosi said:


> It is not uncommon for tubes to buzz and hum when they are new. Typically, after 10 to 20 hours of use they quiet down. If they do not improve, you may want to consider requesting new tubes or money back from the vendor.


 
 Oh ok.
  
 Here's a pic of cut off pins of the tube and circuit board of the little dot,

  

  
 It seems that the Little Dot 1+ is set up to EF92 correctly.
 Pins are cut off as well.
  
 I'll keep playing music with them to see if they go away over a couple of days.


----------



## MIKELAP

sony slave said:


> Oh ok.
> 
> Here's a pic of cut off pins of the tube and circuit board of the little dot,


 
 this is the pins you cut off arrows
  did you put electrical tape over pins you cut off


----------



## Sony Slave

mikelap said:


> this is the pins you cut off arrows
> did you put electrical tape over pins you cut off


 
 No, I did not 
  
 I'm gonna go to my local radio shack and see if they have some electrical tape.


----------



## TrollDragon

Those pins do not look too flush, try putting the tube back in and do not put it down all the way. To make sure those pins do not touch the socket and see if the hum goes away. A loud hum that is not controlled by the volume control is a problem.


----------



## MIKELAP

sony slave said:


> No, I did not
> 
> I'm gonna go to my local radio shack and see if they have some electrical tape.


 
 You could file down the pins if you have a small file a dremel is not recommended vibration could crack the tube it happened to me


----------



## mordy

Hi Artsi,
  
 Would like to try some octal driver tubes. What do you think of this? ($2/tube + shipping  = $12.24 for two by snail mail)
  
 http://rutubes.com/product/6n9s-6sl7-6su7-ecc35-tube/
  
 or this one : $9 shipped
  
 http://www.ebay.com/itm/VINTAGE-SOVIET-USSR-PENTODE-VACUUM-TUBE-triode-pentode-6N9S-6-9-NOS-/121210957735?pt=Vintage_Electronics_R2&hash=item1c38bc6fa7
  
 There are 60's tubes available as well: ($13.38 for 2 tubes incl shipping)
  
 http://www.ebay.com/itm/VINTAGE-SOVIET-USSR-PENTODE-VACUUM-TUBE-triode-pentode-6N9S-6-9-NOS-/121210957735?pt=Vintage_Electronics_R2&hash=item1c38bc6fa7
  
 How about $17.90 for four 1970's tubes shipped?
  
 http://www.ebay.com/itm/4-x-6SL7-6N9S-1579-tubes-Reflector-NEW-NOS-1970s-/161080111697?pt=Vintage_Electronics_R2&hash=item25811f7251
  
 It is difficult for me to find information what are the best brands and best years of inexpensive 6N9S tubes. There is no difficulty to find the most expensive ones...
  
 If you have a link to a site evaluating these tubes, please post it.


----------



## TrollDragon

The Dremel cutoff disk does an *amazing job* flush cutting the pins off of the 6AV6.
 Unless you pull a Deluxe bone head move like I did and forget how to count... 
	

	
	
		
		

		
			




  
 Luckily I was able to jury rig a pin from twisted Cat 5 cable and butt solder it back in place. The glass of the NEC 6AV6 was a lot stronger than the glass in the 6Ж5П I tried to solder the permanent 2-7 strap to, which cracked as soon as the heat was applied.

  

 The pseudo pin is solid and the tube still works but the treble is so harsh on it that I will never play these tubes...
 But they do look pretty when all lit up.


----------



## mordy

Hi Gibosi,
  
 Playing my 1975 Amperex A frame 6DJ8. In comparison to my Sylvania 12AX7A they are more detailed, etched, with stronger bass and punch in treble, but the Sylvania is more musical and sweet, but with less detail. Both tubes are very enjoyable and the jury is still out what I prefer.
  
 What is not enjoyable is that the wires on my spider web adapter break all the time when I move the adapter. They break at the soldering points at the Vector adapter.
  
 What kind of wire is the thickest and most flexible that can be used with the Vector adapter (fitting through the little holes on the tabs) without soldering and just using the pressure of the tabs? Presently I use solid 22 gauge wire. Would stranded wire be better?
  
 On my 6DJA adapter I use a breadboard with 30 gauge wirewrap solid wire without soldering. This seems to work better, but it seems to me that the wire is too thin to resist breakage (which already happened).
  
 Any advice?


----------



## Sony Slave

I had the tubes barely get inside the sockets and they were still humming.
 It wasn't noticeable when music was playing, unless there was a quite passage.
  
 It reminded me of the Tung-Sols that I purchased a while back, they had a quieter hum that these Sylvanias and it had distortion as well, but it made it up for adding a touch of warmth to my cans.
  
 I'm guessing it's the tube itself correct?
  
 I'll guy buy a smile file along with the electrical tape. It that doesn't solve the problem, i'll keep using them to see if they improve.


----------



## Artsi

mordy said:


> Hi Artsi,
> 
> Would like to try some octal driver tubes.


 
 I bought mine from here http://www.ebay.co.uk/itm/271295938589. Packets come much quicker from Bulgaria than from Russia. People say that old ones with metal base are better, but i can't say anything about that. Parts inside tubes look similar to me from 50's to 80's with "plastic" base.
http://www.ebay.co.uk/itm/6SL7-RARE-VINTAGE-6N9S-1579-2-NEW-NOS-1959-/161044298382
http://www.ebay.co.uk/itm/USSR-6N9S-1579-6SL7-tube-Double-triode-NOS-QTY-4-/251240604156
  
 Older metal base version seem to have shinier plates. So there could be difference in sound.
http://www.ebay.co.uk/itm/6N9S-6H9C-6SL7-1579-Vintage-Year-1954-Metal-Base-Black-Plate-MELZ-Strong-Tube-/141102357107


----------



## TrollDragon

@mordy Get some 22 AWG stranded wire for you hook ups, clean off the terminals of the vector sockets with some sand paper or a file till the brass shows then solder with a high heat gun till the solder melds with the brass. Then tin and solder your 22 AWG stranded to the terminals. They won't break again if soldered properly this way I guarantee it!

Use the 22 AWG on your tube bread board as well.


----------



## MIKELAP

mordy said:


> Hi Artsi,
> 
> Would like to try some octal driver tubes. What do you think of this? ($2/tube + shipping  = $12.24 for two by snail mail)
> 
> ...


 
http://www.head-fi.org/t/353051/best-sounding-6sl7-short-glass-version-tubes-advice-need-it-pls     Skylab speaks of favorite 6SL7 tubes


----------



## Sony Slave

I covered the exposed pins on the Sylvanias with electrical tape, and I still hear the humming. I didn't file down the metal yet, so I placed an order for some 10pc small metal files to be shipped in tomorrow.


----------



## TrollDragon

I don't think the pins nubs are causing your hum, if you had the tubes partially seated and they still hummed. It is probably just the tubes themselves.


----------



## Oskari

trolldragon said:


>


 
  
 Here's another one:


----------



## mordy

Just as a precaution, some tubes are more sensitive to RF noise than others. Do you have a portable phone (or similar device) near your amp? If so, try to move it.
  
 You can also try to (if feasible) to lift up the amp and move it slightly in different directions to see if the hum decreases.
  
 I get hum when I play at very loud receiver levels. To avoid it I found that turning up the amp til around 3 o'clock (below clipping) and keeping my receiver on a low volume setting helps, but then I am usually listening through speakers.
  
 You could just turn up the volume without music and listen at what level hum appears.
  
 Perhaps playing with the gain switches/settings underneath the amp will help to get a good volume on headphones with a lower main volume control setting.


----------



## mordy

Ho Oskari,
  
 And I always thought the Philips Co invented the Phillips screwdriver! After all, they invented the compact cassette and the CD....
  
  





 The screw was invented in the early 30’s by Henry F. Phillips, a Portland, Oregon businessman. He knew that car makers needed a screw that could be driven with more torque and that would hold tighter than slotted screws. Car makers also needed a screw that would center quickly and easily, and could be used efficiently on an assembly line. The Phillips screw was designed so that it could be driven by an automated screw driver with increasing force until the tip of the driver popped out without ruining the screw head. So what many consider a design flaw is actually a feature (at least if you’re a car manufacturer).
  
 Looks like an interesting radio in the background. Blaupunkt?


----------



## Oskari

mordy said:


> Looks like an interesting radio in the background. Blaupunkt?


 
  
 Surprisingly enough, it's a Philips radiogram, used to belong to my grandparents.


----------



## Sony Slave

mordy said:


> Just as a precaution, some tubes are more sensitive to RF noise than others. Do you have a portable phone (or similar device) near your amp? If so, try to move it.
> 
> You can also try to (if feasible) to lift up the amp and move it slightly in different directions to see if the hum decreases.
> 
> ...


 
 The bad thing is, the hum starts very low, and as the brighter the tubes get, the louder the hum. In fact, I can turn the volume down to zero on the Little Dot 1+, and i'll still hear it hum loudly when my music is turned off. 
  
 I don't have a cell phone or anything else similar near the little dot.
  
 Could you show me how to get to the gain settings?
  
 I'll try moving it around though right now.


----------



## gibosi

mordy said:


> What is not enjoyable is that the wires on my spider web adapter break all the time when I move the adapter. They break at the soldering points at the Vector adapter.
> 
> What kind of wire is the thickest and most flexible that can be used with the Vector adapter (fitting through the little holes on the tabs) without soldering and just using the pressure of the tabs? Presently I use solid 22 gauge wire. Would stranded wire be better?
> 
> On my 6DJA adapter I use a breadboard with 30 gauge wirewrap solid wire without soldering. This seems to work better, but it seems to me that the wire is too thin to resist breakage (which already happened).


 
  
 I am just winging it as I go along!  lol. I have very little experience with projects like this and would suggest that you always follow TrollDragon's advice rather than copy what I have done. That said, I am currently using solid core 28 gauge wire to connect my Vector adapters to the breadboard. However, very little thought went into this decision as it was simply what I had on hand, plus some 30 gauge wire, and figured that the 28 gauge would be a bit more durable. And so far, I have not had any wires break. However, I have been thinking that I should replace these wires with something better. And stranded 22 gauge would be both more sturdy and more flexible.


----------



## mordy

Hi Mikelap,
  
http://www.head-fi.org/t/353051/best-sounding-6sl7-short-glass-version-tubes-advice-need-it-pls
  
 Thanks for the link - read the whole thing, not too long. But it was written long ago, in 2008. Again, no mention of Russian and Chinese tubes.
  
 Wonder what happened to the guy with 2000-3000 tubes......


----------



## LogicAudio

I have lots of 6080 tubes with "Delta 6080" labeled on them. does anyone know what the original manufacturer?


----------



## Sony Slave

I decided I'll go ahead and buy a pair of 6Dj8/ECC88 U.S.A. made tubes as well, when I get paid <onday lol.
 Even though i'm on a high school job budget, these posts are pretty compelling investments imo.  
  
 After I buy the 7 pin socket adapters, what pins do I put in to make it work right? And which ones do I bend or cut off?
  
  
 Oh, and the Sylvanias stopped humming too.


----------



## Artsi

You could drive both channels with one 6DJ8 double triode with connections like this.

 You just need to be handy and creative...


----------



## Sony Slave

artsi said:


> You could drive both channels with one 6DJ8 double triode with connections like this.
> 
> You just need to be handy and creative...


 
 So if I decide to buy this 9 pin adapter for the Little Dot 1+, does it requier any soldering? And more so, how do I hook it up? Any tools that are needed?


----------



## Artsi

sony slave said:


> So if I decide to buy this 9 pin adapter for the Little Dot 1+, does it requier any soldering? And more so, how do I hook it up? Any tools that are needed?



 

www.head-fi.org/t/686893/how-to-make-an-adapter-to-use-double-triode-tubes-with-little-dot-mk-ii
If you use only 6DJ8 you can forget switch. MK I+ is little trickier to do the box since it has decorations.


----------



## Sony Slave

artsi said:


> sony slave said:
> 
> 
> > So if I decide to buy this 9 pin adapter for the Little Dot 1+, does it requier any soldering? And more so, how do I hook it up? Any tools that are needed?
> ...


 
 Could I just cut off the pins and set it to E92, or is it absolutely necessary to do use the adapter?
 Perhaps Gibosi could show us a picture of how his Little Dot looks with the 6DJ8 tubes...


----------



## Artsi

Here is a good text about 6SL7 and 6SN7 tubes.
http://boneshifi.blogspot.fi/2013/07/the-6sl7-and-6sn7-family-of-tubes.html

And here is another.
http://www.hifi-tunes.com/the-evolution-of-a-constant-glow-in-high-fidelity/


----------



## Sony Slave

artsi said:


> Here is a good text about 6SL7 and 6SN7 tubes.
> http://boneshifi.blogspot.fi/2013/07/the-6sl7-and-6sn7-family-of-tubes.html


 
 The link is blocked at my school, i'll have to wait till I get home. 
	

	
	
		
		

		
			





 
  
 Oh, never mind, I don't think this post was directed towards me.


----------



## mordy

Hi Artsi,
  
 Thanks for the link - very useful


----------



## gibosi

sony slave said:


> Could I just cut off the pins and set it to E92, or is it absolutely necessary to do use the adapter?
> Perhaps Gibosi could show us a picture of how his Little Dot looks with the 6DJ8 tubes...


 
  
 You do not need to set your amp to E92 to run double triodes. E95 is fine. However, you cannot just cut pins and insert them into your sockets. You need the adapters to re-route tube-pins 7 and 8 to get the grid and cathode connected.
  
 There have been numerous postings on how to use two 6DJ8s in the LD. I humbly suggest that you learn how to search this forum:
  
 Notice at the top and bottom of each page there is "Search This Thread." This is how I pulled the following links. Give it try. 
  
 http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/3045#post_9830528
  
 http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/3135#post_9842518
  
 http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/3150#post_9844996
  
 http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/3150#post_9845096


----------



## vic2vic

Hi,
 I'm planning to build a 1x6DJ8 to 2x7 pins sockets "Magic Box" adapter, as from Artsi super clear and detailed guide. Wish me luck on it, as it's my first DIY mini-project  (so far I'm just waiting for all sockets, boxes, wiring to arrive in my mailbox).
  
 Looking at the future, if I'd like to try and roll also some 6SL7 octal tubes on the same box, can I use this *9 pin to 8 pin adapter **on top of the 6DJ8 socket** ?*
http://www.ebay.com/itm/1-convert-tube-socket-12AX7-12AU7-to-6SL7-6SN7-9-pin-to-8-pin-/281031554093?pt=US_Amplifier_Parts_Components&hash=item416ec9342d
  
 The eBay description mentions that the 8 pins are re-routed for a 12AX7 tube, but usually 12AX7 are listed as "close relatives" of the 6DJ8, so I'm just wondering if the wiring in the adapter is actually the same for 6DJ8s.
 Thanks for your help.


----------



## gibosi

vic2vic said:


> Hi,
> I'm planning to build a 1x6DJ8 to 2x7 pins sockets "Magic Box" adapter, as from Artsi super clear and detailed guide. Wish me luck on it, as it's my first DIY mini-project  (so far I'm just waiting for all sockets, boxes, wiring to arrive in my mailbox).
> 
> Looking at the future, if I'd like to try and roll also some 6SL7 octal tubes on the same box, can I use this *9 pin to 8 pin adapter **on top of the 6DJ8 socket** ?*
> ...


 
  
 I assume that adapter will work. However, I bought my adapter from a different eBay vendor:
  
 http://www.ebay.com/itm/320659633166?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649
  
 And yes, this adapter converts 6SL7 to 12AX7. The wiring of the heaters is different for 6DJ8 and 12AX7, but if you build the version of the magic box with the switch, then this adapter will do the trick. Just flip the switch to the 12AX7 position and you are good to go.


----------



## mordy

Hi Gibosi,
  
 I am intrigued by Artsi's octal three tube set-up (alternative upgrade of MKIII to MK9?). Two questions:
  
 Is there available an adapter from 6SN7 to 6N6P? (Have not been able to find it)
  
 Assuming that there is such a thing available, would it fit on top of the 6N6P sockets with the octal tubes in place?


----------



## Artsi

mordy said:


> Hi Gibosi,
> 
> I am intrigued by Artsi's octal three tube set-up (alternative upgrade of MKIII to MK9?). Two questions:
> 
> ...



 

You mean adapter like this.
www.ebay.com/itm/two-Adapters-for-ECC32-6SN7-plug-adapters-to-instead-6N6P-tubes-/261051244115

My guess is that adapter diameter is about 32mm.


----------



## mordy

Hi Oskari,
  
  
 Ouch, wish it was Taiwanese dollars which would be around $2 USD. But yes, these are them, but too expensive to pay $62 for two.
  
 I bet that you could make them and throw in two tubes for much less!
  
 What makes the 6SN7 into power tubes over the 6SL7 tubes? Can they be used reversely?


----------



## Anaximandros

Hi Artsi,
  
 can you do a wiring diagramm for your 6SN7 to 6N6P tube like you did with the 6DJ8 adaptor?
  
 Before making only the box for the 6DJ8 tube I want to integrate the adaptors for the octal powertubes. This box will be made of ebony wood and I don't have enough for 2 boxes 
  
 Thanks


----------



## SwanSong

I'm posting a copy of my LD1+ thread here since there's more activity here. I'm planning to purchase HE-500's and need a amp so I am looking at the LD1+. My music is mostly bebop-jazz, Latin jazz, fusion, acid jazz and ballad r&b. All recommendations much appreciated !

(Copy)
New to the LD 1+ need help understanding what I'm reading. Based on the forums it sounds like these options will work best with my HE-500 phones.

Please review the below items to confirm they'll work with the LD1+ and what else will be required?

LT1364CN LT1364CN8 DIP8 Dual and Quad 70MHz, 1000V/us Op Amps
lxr0000527 LT1364CN8 DIP8

New Burr-Brown OPA2107AP DIP-8
Precision Dual Difet(R) Operational Amplifier

2x Voshod 6ZH1P-EV

2x Mullard M8161/CV401

I think these upgrades will give me neutral and warm options to roll in and out?

I'm confused with the opamp usage more than the tubes since I've read some saying adapters needed for dual opamps replacement??

Thanks guys


----------



## SwanSong

Any feedback from HE-500 users using LD amps would be great!!!!!


----------



## gibosi

swansong said:


> LT1364CN LT1364CN8 DIP8 Dual and Quad 70MHz, 1000V/us Op Amps
> lxr0000527 LT1364CN8 DIP8
> 
> New Burr-Brown OPA2107AP DIP-8
> ...


 
  
 Generally, op amps are cheap, so I suggest you simply try them all to see which you like best. And if you would like to try a couple more, the MUSES02 and the LME49990 are also very good. Currently the MUSES02 is my op amp of choice, but unfortunately, it is not as cheap as the others.
  
 The tubes you have chosen are among the best of the "traditional" tubes, but I would also suggest that you consider getting a pair of 6DT6 (RCA and Sylvania are popular) and 6HM5 (GE, EI and Sylvania - avoid the short squat tubes - get the taller tubes).
  
 I don't have the HE-500 (my HE-300 has dynamic drivers) so I can't help you there....


----------



## SwanSong

gibosi said:


> Generally, op amps are cheap, so I suggest you simply try them all to see which you like best. And if you would like to try a couple more, the MUSES02 and the LME49990 are also very good. Currently the MUSES02 is my op amp of choice, but unfortunately, it is not as cheap as the others.
> 
> The tubes you have chosen are among the best of the "traditional" tubes, but I would also suggest that you consider getting a pair of 6DT6 (RCA and Sylvania are popular) and 6HM5 (GE, EI and Sylvania - avoid the short squat tubes - get the taller tubes).
> 
> I don't have the HE-500 (my HE-300 has dynamic drivers) so I can't help you there....


 
 Thanks gibosi,
 The opamps I listed are they direct replacements for the stock opamp (1 to1) ?  I read other opamp suggestions required adapters for dual opamp configuration?
 These opamps are both about $15 shipped on ebay is that a good price?  The Voshod matched pair i found on Yen audio ebay page for $36 shipped.  The Mullard's I couldnt find on ebay but found elsewhere for $60 shipped and match tested.  I'm just wondering if these are ok prices?
  
 Thanks again


----------



## Edgard Varese

swansong said:


> Thanks gibosi,
> The opamps I listed are they direct replacements for the stock opamp (1 to1) ?  I read other opamp suggestions required adapters for dual opamp configuration?
> These opamps are both about $15 shipped on ebay is that a good price?  The Voshod matched pair i found on Yen audio ebay page for $36 shipped.  The Mullard's I couldnt find on ebay but found elsewhere for $60 shipped and match tested.  I'm just wondering if these are ok prices?
> 
> Thanks again


 
  
 You can get the OPA2107 for FREE (inc shipping) from Texas Instruments.  Register on their website and request a sample (ask for two, just in case because the pins are a little fragile).  Dip 8 opamps require no adapters (SOIC opamps do require adapters).


----------



## superdux

these voskhods are way cheaper:
  
 http://www.ebay.de/itm/130436695928?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649
  
 but don´t buy all.I got them recently and they already sound good with no burn-in so i´m getting a second pair tomorrow!


----------



## gibosi

swansong said:


> Thanks gibosi,
> The opamps I listed are they direct replacements for the stock opamp (1 to1) ?  I read other opamp suggestions required adapters for dual opamp configuration?
> These opamps are both about $15 shipped on ebay is that a good price?  The Voshod matched pair i found on Yen audio ebay page for $36 shipped.  The Mullard's I couldnt find on ebay but found elsewhere for $60 shipped and match tested.  I'm just wondering if these are ok prices?


 
  
 In my opinion, paying extra for "matched" tubes for the LD is a waste of money.  Anyway, I have purchased two pairs of Voskhod from this vendor:
  
 http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=130436695928&ssPageName=ADME:L:OC:US:3160
  
 one pair for $3 plus $12 shipping, or $15. (Oh I see that Superdux beat me to it! 
  
 Instead of the M8161/CV401, what you really want is the M8161/CV4015. I think someone made a mistake in their typing and left off the 5.....


----------



## SwanSong

Thanks Edgard & superdux, I'll check on the freebie opamp for sure and the Voshkod combo first. I love the rocket sound in my dac I'm guessing the opamp should warm it up a bit?


----------



## SwanSong

Thanks any suggestions where to buy M8161?


----------



## Sony Slave

swansong said:


> Thanks any suggestions where to buy M8161?


 
 The M8161s seem really hard to find, at least for me, I only found one seller, and he seems to be only selling one. 
http://www.ebay.com/itm/Vintage-58-Mullard-M8161-CV4015-tube-Horseshoe-getter-superb-condition-EF92-/380574433134?pt=Vintage_Electronics_R2&hash=item589c00ff6e
  
 $15 for the tube, and $10 for shipping.


----------



## SwanSong

sony slave said:


> The M8161s seem really hard to find, at least for me, I only found one seller, and he seems to be only selling one.
> http://www.ebay.com/itm/Vintage-58-Mullard-M8161-CV4015-tube-Horseshoe-getter-superb-condition-EF92-/380574433134?pt=Vintage_Electronics_R2&hash=item589c00ff6e



I sent an email to this seller requesting two but no word yet. I found another on the web but it's $26 ea plus shipping + match testing about $60 total


----------



## Artsi

anaximandros said:


> Hi Artsi,
> 
> can you do a wiring diagramm for your 6SN7 to 6N6P tube like you did with the 6DJ8 adaptor?
> 
> ...


 
 Here is wirings for one channel B9A to Octal for 6SN7 as powertube. Remember are you looking socket from top or bottom.


----------



## SwanSong

After all this I just noticed the HE-500's 38ohm recommend 1w power and the LD1+ only has 800ma @ 32omh. Suggestions anyone??


----------



## Anaximandros

Thank you very much Artsi. 
How would you compare the difference between the 6SN7 and 6N6P as powertubes?


----------



## Artsi

anaximandros said:


> Thank you very much Artsi.
> How would you compare the difference between the 6SN7 and 6N6P as powertubes?


 
 I can't compare differences between 6N6P-IR and 6N8S directly, because can't use same driver for both of them.
 With octals there is better music flow, smoother sound with excellent instrument separation. And everything sounds more present.
 After octals the combination of 6N6P-IR and 12AZ7A sounds little harsh and could there be even some distortion.
  
 I'm waiting impatient for more octals to listen. Hope to get those last week ordered tubes tomorrow.
	

	
	
		
		

		
			




 I managed to won auction of 3 KEN-RAD 6SL7GT's with three different plates. I think those KEN-RAD's are made in 40's or early 50's.
  
 Nowadays it seems that even deaf people can make music:

 aargh my ears! How could bass drum sound like that! Where is dynamic? Why everything is just same flat distortion.
  
 But there is a cure. Me and my octals like.


----------



## Artsi

swansong said:


> After all this I just noticed the HE-500's 38ohm recommend 1w power and the LD1+ only has 800ma @ 32omh. Suggestions anyone??


 
 If my calculations were right with 89dB/mW sensitivity you get around 119dB with 1000mW. Is 119dB your normal listening volume? Hope not, or you become deaf soon.


----------



## Artsi

mordy said:


> What makes the 6SN7 into power tubes over the 6SL7 tubes? Can they be used reversely?


 
  
 6SN7 has gain 20, which is about the same as 6N6P. 6SL7 gain is 70. 6SN7 delivers more watts.
  
 Of course 6SL7 could be used as powertube, but my experience is that you lose power and dynamic.


----------



## SwanSong

artsi said:


> If my calculations were right with 89dB/mW sensitivity you get around 119dB with 1000mW. Is 119dB your normal listening volume? Hope not, or you become deaf soon.



Thanks Artsi I don't have a clue regarding these power/sensitivity ratings. I would much rather spend $250 on a maxed out LD1 vs $500 and up for the other amps. And I really like the look of the LD amps and size for my desktop.


----------



## Kestovitutus

Those 6J1P-EV Voshkods are good choice, even if they are not military grade like mine aren't.. You really can't go wrong with that price.


----------



## mojorisin35

swansong said:


> Thanks any suggestions where to buy M8161?


I have a pair thatbi would sell. Pm me an offer shipping is from Canada


----------



## hypnos1

audiofanboy said:


> Lol, it's like you read my mind; I'm building my two adapters with the exact same plan in mind! Hopefully, a switch between triode sections every, say, 20-50 hours could save all four triodes from cathode poisoning (and from losing their rather high resell value) and make the "two double triodes with only one section used' solution more appealing and less wasteful.
> 
> Glad your first adapter worked on you first try. I've had times in the past when I got too excited and drowned a freshly made DIY adapter in hot glue _before_ testing, and had a bad surprise a few minutes later, so now I'm extra careful about that...
> 
> I'm trying to make adapters that are even a bit smaller and thinner than yours though, like no more than 1.25cm or 1/2" high and with with narrowed B9A sockets. I'll take a picture when I'm done -if I ever manage to be lol...


 
  
 As an extension to the 2 differently-wired adapters, I got to thinking - if we double up on them, with just 2 tubes we have 4 possible combinations of individual triodes; with 3 tubes, 12; and with 4 tubes 16!! Given that unless we have _balanced dual _triode tubes, they could possibly be a tad _out _of balance...thus with the option of multiple combinations we must eventually hit on a _magical_ pairing...just a thought...
  
 The Voskhod 6N2P-ERs now have 40+ hours on them, and thankfully the bass is developing VERY nicely...not _quite _the punch of the RCA 6DJ8s, but with more articulation - assisted perhaps by the greater soundstage and overall clarity. The separation and spatial character of these tubes - on my gear - is amazing. The more closed-in nature of the RCAs (which I believe can be a slight tendency of the Amperexes, unless you can afford the top-flight versions) has me preferring the Voskhods. It will be interesting to see how some TFK ECC88s compare in due course...
  
 Edit.
 ps. Forgot to mention. The detail from these is also quite stunning...and considering they can be found for $4.50 ea, they represent amazing value-for-money...


----------



## gibosi

artsi said:


> But there is a cure. Me and my octals like.


 
  
 These past few days I have found myself listening to Holly Cole's* Night* over and over. My Sylvania 5751 (1950's, 3 micas, D-getter and black plates) really like this album.
  
 Maybe you and your octals will like this too? 
  
 Holly Cole Trio - You've Got a Secret (live version)


----------



## Artsi

gibosi said:


> These past few days I have found myself listening to Holly Cole's* Night* over and over. My Sylvania 5751 (1950's, 3 micas, D-getter and black plates) really like this album.
> 
> Maybe you and your octals will like this too?
> 
> Holly Cole Trio - You've Got a Secret (live version)


 
 Very good quality as a live performance. Me like!


----------



## Oskari

Now beat this!


----------



## TrollDragon

Kick it up into 720p for the best sound!
Harvest - Opeth - Royal Albert Hall 
 \m/
	

	
	
		
		

		
		
	


	




\m/


----------



## jaywillin

oskari said:


> Now beat this!





 wow, very, very nice !


----------



## jaywillin

how's this ??


----------



## Audiofanboy

Sadly, my religion forbids me from listening to music on youtube through my headphones... Yeah, tough hi-fi gods, I know; but my religion also has its perks, even though my wallet may disagree lol...
  
 Meanwhile, a seemingly silly idea crossed my mind earlier, after reading up on the history of OTL tube amps since the 70s. Most of the "top tier" premium single ended triode OTL amps are "no feedback" amps, whereas even on the highest gain setting our MK III & IVs still have a 470k ohms resistor acting a negative feedback input. So here's the question: would it seem totally unreasonable to just remove that resistor? Bonus questions: would that screw up the circuitry somehow, would it actually sound better, and should ever so slighly higher "volume" be expected if that last bit of feedback were to be removed?
  
 Just a thought; thinking and -very- light DIY work being pretty much my only purpose around here lol (don't expect crazy cargo ship sized adapters from me)!
  
 As a side note, I wonder if I might not prefer (read "take more listening pleasure with") my Amperex OG tube than over my more premium Amperex US 6922 tube. The OG really has a _special_ quality to its sound. Listening with the Heerlen-made 6DJ8 from the OG years, it's not hard to pinpoint what sounds great actually: it all boils down to lush -not warm- mids, sweet highs and chocolatey tight bass, all this over a dark, transparent et palpable background. I guess I may be more of a sucker for the _tube sound_ and its richness than I thought huh (though I'm also a sucker for ultra detail and balanced FR)?


----------



## TrollDragon

audiofanboy said:


> Meanwhile, a seemingly silly idea crossed my mind earlier, after reading up on the history of OTL tube amps since the 70s. Most of the "top tier" premium single ended triode OTL amps are "no feedback" amps, whereas even on the highest gain setting our MK III & IVs still have a 470k ohms resistor acting a negative feedback input. So here's the question: would it seem totally unreasonable to just remove that resistor? Bonus questions: would that screw up the circuitry somehow, would it actually sound better, and should ever so slighly higher "volume" be expected if that last bit of feedback were to be removed?


 
 Some of the guitar amps can have NFB bypass put in, it can increase distortion and give more volume. 
  
 I'd put a 500K pot in place so you can adjust it and observe the effects.


----------



## MIKELAP

trolldragon said:


> Kick it up into 720p for the best sound!
> Harvest - Opeth - Royal Albert Hall
> \m/
> 
> ...


----------



## gibosi

audiofanboy said:


> Sadly, my religion forbids me from listening to music on youtube through my headphones... Yeah, tough hi-fi gods, I know; but my religion also has its perks, even though my wallet may disagree lol...
> 
> [snip]
> 
> As a side note, I wonder if I might not prefer (read "take more listening pleasure with") my Amperex OG tube than over my more premium Amperex US 6922 tube. The OG really has a _special_ quality to its sound. Listening with the Heerlen-made 6DJ8 from the OG years, it's not hard to pinpoint what sounds great actually: it all boils down to lush -not warm- mids, sweet highs and chocolatey tight bass, all this over a dark, transparent et palpable background. I guess I may be more of a sucker for the _tube sound_ and its richness than I thought huh (though I'm also a sucker for ultra detail and balanced FR)?


 
  
 It's not as if I go out of my way to listen to youtube, but I find it to be a very good way to learn about new music. I first heard Holley Cole on a youtube video posted in another forum. And I was so impressed that I immediately grabbed one of her albums.
  
 Listening to my Sylvania 5751 these past several days, I am not feeling any urge to get back to my US-Amperex 6922. However, I have a few more premium 6DJ8 (1975 Voskhod 6N23P, Heerlen, Holland E188CC and Suresnes, France E88CC) coming soon. And of course I am very curious to discover whether the Sylvania will stay on top?


----------



## Audiofanboy

trolldragon said:


> Some of the guitar amps can have NFB bypass put in, it can increase distortion and give more volume.
> 
> I'd put a 500K pot in place so you can adjust it and observe the effects.


 
  
 Interesting. So you wouldn't so much remove all feedback but use less, or implement a versatile way to change the resistor value huh?
  
 Well, if anyone with good DIY soldering skills is willing to try, I'd love to hear how it sounds! I could snap off a resistor or two in my amp if needed, but soldering a whole pot or a new resistor in there just involves to much handiwork for me lol... I'm pretty sure it would be worth trying though, as the general feedback setting really does have a strong influence on the sound (and all extra gain is good gain in my book; I've been trying to squeeze the last bit of power out of my amp for months now, with some success).
  


gibosi said:


> It's not as if I go out of my way to listen to youtube, but I find it to be a very good way to learn about new music. I first heard Holley Cole on a youtube video posted in another forum. And I was so impressed that I immediately grabbed one of her albums.
> 
> Listening to my Sylvania 5751 these past several days, I am not feeling any urge to get back to my US-Amperex 6922. However, I have a few more premium 6DJ8 (1975 Voskhod 6N23P, Heerlen, Holland E188CC and Suresnes, France E88CC) coming soon. And of course I am very curious to discover whether the Sylvania will stay on top?


 
  
 Really? So right now, you don't find anything fundamentally "lacking" running a 5751? Interesting, especially compared to all those pretty premium 6DJ8 you've been using. I'm curious to know how you'll like the Heerlen E188CC though!
  
 I'm waiting for my last two US Amperex 6922 tubes (and two new -smaller- 9 pin sockets, after my utter failure to make small adapters this weekend) to compare them both single and as a pair with my single OG tube. I'm hoping the two late 64 and early 65 US tubes will be decently matched (enough that I can't hear the difference, which is virtually always the case; they were only made 8 weeks apart too, so I wouldn't worry about sound), and I also have high hopes for the earlier 62 "USN" tube; they say the earlier the better for those tubes, so I wouldn't exactly be surprised to find large differences in sound for tubes of different years.


----------



## TrollDragon

audiofanboy said:


> Interesting. So you wouldn't so much remove all feedback but use less, or implement a versatile way to change the resistor value huh?


 
 Hey AFB!
  
 I don't know enough of the math behind the NFB resistor to say if just taking it out completely would have any dire effects or not, that is why I suggested a pot and the ability to change the value as quite a few amps have a variable NFB, but thinking about that now we want to open this circuit not reduce it to zero... Don't mind the barin fart.... 
	

	
	
		
		

		
		
	


	



  
 Or someone with a LD MKII can just unsolder one side of the resistor and see what happens since the MKII's board is so much easier to gain access to.
  
 It's like they say "No pain, No Gain!" Here is a interesting little read about NFB...
http://www.hometheaterhifi.com/volume_5_4/essaynegativefeedbackoctober98.html


----------



## Audiofanboy

trolldragon said:


> Hey AFB!
> 
> I don't know enough of the math behind the NFB resistor to say if just taking it out completely would have any dire effects or not, that is why I suggested a pot and the ability to change the value as quite a few amps have a variable NFB, but thinking about that now we want to open this circuit not reduce it to zero... Don't mind the barin fart....
> 
> ...


 
  
 Hmm... Again, interesting. And also incredibly confusing lol!
  
 I've had a chance to try the different gain / feedback settings on my MK IV SE a few times already, and despite what I've read, I've always found that the higher gain setting (lowest feedback, just one 470k resistor controlling global feedback per channel, if I understand correctly) sounded the best. The lower settings had "richer harmonics" and a very musical sound, but ultimately more feedback seemed to "dull" the amplifier a bit, whereas the lowest feedback setting (gain x10) had the most "air" and hi-fi sound -hence my wondering if no feedback at a all would yield even better sound.
  
 I also never noticed any kind of roll-off with the higher gain setting; if anything I noticed the opposite phenomenon...
  
 Come on, someone try it! I won't be able to sleep anymore until I know what it does lol!


----------



## gibosi

audiofanboy said:


> Really? So right now, you don't find anything fundamentally "lacking" running a 5751? Interesting, especially compared to all those pretty premium 6DJ8 you've been using. I'm curious to know how you'll like the Heerlen E188CC though!


 
  
 The Sylvania 5751 TMBP (Three Micas Black Plates) is a complete package. It lacks nothing. To my ears, it is equal, and perhaps better than my US-Amperex 6922, and it is certainly better than my Hamburg Valvo. If you can find one of these at a good price I encourage you to grab one. Compared to the other 12AX7s you have trialed, I think you will be very pleasantly surprised. But of course, I am hoping that the Heerlen E188CC and the others on their way to me will offer some formidable competition.


----------



## mordy

Can somebody explain what the purpose of this adapter is? Could it be used for any application re the Little Dot?
  
  
















  
 Here is the link to this supplier:
  
 http://www.ebay.com/itm/1pc-EC90-6C4-CV133-EC90-6C4-CV133-ECC82-12AU7-Tube-adapter-6-3v-version-/190905983642?pt=US_Home_Audio_Amplifiers_Preamps&hash=item2c72e2229a


----------



## Artsi

mordy said:


> Can somebody explain what the purpose of this adapter is? Could it be used for any application re the Little Dot?


 
  
 Instead of 1 12AU7 you can use 2 EC90. If one have adapter that can use one 12AU7 to drive both channels with little dot, then with that Ebay adapter you can use 2 EC90 tubes. 
	

	
	
		
		

		
			





 I do not think you get better sound with that thing.


----------



## Artsi

I'm listening speechless. And i got the last one from electols...


----------



## gibosi

artsi said:


> I'm listening speechless. And i got the last one from electols...


 
  
 Beautiful! While it bears the Heintz and Kaufman brand, I looks to be a Tung-Sol, among the best of the best.


----------



## MIKELAP

gibosi said:


> The Sylvania 5751 TMBP (Three Micas Black Plates) is a complete package. It lacks nothing. To my ears, it is equal, and perhaps better than my US-Amperex 6922, and it is certainly better than my Hamburg Valvo. If you can find one of these at a good price I encourage you to grab one. Compared to the other 12AX7s you have trialed, I think you will be very pleasantly surprised. But of course, I am hoping that the Heerlen E188CC and the others on their way to me will offer some formidable competition.


 
 Whats the average price of those Sylvanias 5751 TMBP those are 12 volts you need only 1 of those wright.


----------



## gibosi

mikelap said:


> Whats the average price of those Sylvanias 5751 TMBP those are 12 volts you need only 1 of those wright.


 
  
 Yes, this ia a premium version of the 12AX7, a dual triode, so you need only one tube. However, on eBay I am seeing mostly multiples of two and three. The only single I see is below. But untested and no returns, so perhaps a bit risky....
  
 http://www.ebay.com/itm/301011472427?ssPageName=STRK:MEBIDX:IT&_trksid=p3984.m1426.l2649
  
 The best price I am seeing on a pair is from Sweden, but $25.00 shipping to the US is a bit much...
  
 http://www.ebay.com/itm/301015317776?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649
  
 This tube is rare, but every so often a good deal does pop-up, so the best strategy is patience. I got mine for $22


----------



## gibosi

A small package from the Czech Republic arrived today with a Tesla E88CC, manufactured in 1964, with gold pins and gold grids.
  

  
 And another small package from Massachusetts arrived with a Tung-Sol JAN-CTL-6SU7GTY, apparently manufactured in 1947. As my amp is currently set up for 12AX7s, will pop this big guy in first. 
  

  
 Edit: 322 = Tung-Sol. Maybe 0-47 is 1950 week 47?


----------



## gibosi

gibosi said:


> And another small package from Massachusetts arrived with a Tung-Sol JAN-CTL-6SU7GTY, apparently manufactured in 1947. As my amp is currently set up for 12AX7s, will pop this big guy in first.


 
  
 I agree with Artsi.... This is a keeper! It's a tad bit warmer than the Sylvania 5751, with similar clarity, transparency and 3-D stage as compared to the very best 6DJ8/6922 and 12AX7/5751. You know.... it's getting harder and harder to figure out which tube I like best! lol But what a wonderful problem to have....


----------



## Artsi

I got two CEI stamped made in Holland 6SN7GT's as powertubes. I could be imaging things, but sound is little sharper through these. Structure is much like Russian 6N8S, but there is little differences.

 I also got one very rare tube:

 Ten has totally black glass. With led light i could see that there is 2 round tubes between micas.
  
 And i have also another re-stamped tung-sol.


----------



## Oskari

artsi said:


> I got two CEI stamped made in Holland 6SN7GT's as powertubes. I could be imaging things, but sound is little sharper through these. Structure is much like Russian 6N8S, but there is little differences.
> 
> I also got one very rare tube:
> Ten has totally black glass. With led light i could see that there is 2 round tubes between micas.


 
  
 That CEI is still a 6N8S. The Ten looks nice. There was a discussion about Japanese brands here a while ago.


----------



## Oskari

gibosi said:


> Edit: 322 = Tung-Sol. Maybe 0-47 is 1950 week 47?


 
  
 I think it is.


----------



## Audiofanboy

How shameful of all of you to be showing pictures of all those huge burly octal base tubes! All this _tube pornography_ won't convince me to spend my hard-earned cash on octals lol. At least not quite yet; I have too much stuff left over to test on 6DJ8 and 6922 tubes to think about this yet.
  
 Still, I can just feel my head getting gradually accustomed to the idea that I will _eventually_ try those tubes... I swear hi-fi is a form of addiction lol...
  
 I got my last two US 6922 in the mail this morning, so that'll give me two more chances to try NY-made Amperex tubes this weekend and give more impressions. I have about two or three different audio related DIY projects to complete this weekend, so actual detailed feedback may have to wait until Monday.


----------



## TrollDragon

Yes by all means, everyone needs moar octals and B9A's!

Then some of you can sell me some of your nicer 7 pin tubes for cheap cheap!


----------



## Sony Slave

artsi said:


> I got two CEI stamped made in Holland 6SN7GT's as powertubes. I could be imaging things, but sound is little sharper through these. Structure is much like Russian 6N8S, but there is little differences.
> 
> I also got one very rare tube:
> 
> ...


 
 I wonder how those tubes look with the lights off?


----------



## mordy

Hi Artsi,
  
 Some time back (p. 238, post #2569 - bottom of page) you provided us with a table of 6V and 12 Volt tubes from the 6DJ8 and 12AX7 families etc that would work with the Little Dot amps. Since I am completely unfamiliar with octal tubes I would appreciate it if you could provide a similar list of octal tube types that are compatible with the LD amps. Perhaps you could use two headings - one for driver tubes and one for power tubes. Also needed are the US, European and Russian tube designations.
  
 This would make it much easier to shop for these tubes. A it is now I simply don't know what the designations are of equivalents of 6SL7 and 6SN7 tubes.
  
 In addition, it would also be very useful if people could recommend certain makes and types for the best sound. (Obviously a work in progress, hoping to find the inexpensive oddball tube that is just as good as the famous ones.)
  
 Another thing I noticed is that many of these tubes are very much in demand and sought after, and a Tung Sol 6SU7GTY tube could sell for $125 (although a search reveals that the same type tube sold for $10 as well).
  
 With thanks in advance,
  
 Mordy


----------



## Nic Rhodes

Tung Sol 6SU7GTY is a wonderful tube but look out for the 6188 also. You can also find 6188 by Sylvania / PhilipsECG at much better prices.
  
 6SL7GT: 6SL7GT, 5691, CV1985, 6113, 6188, ECC35, CV569 [VT 229]
  
 6SN7GT: 6SN7GT, 6SN7GTB, 6SN7WGT, 6SN7WGTA, 6SN7WGTY, 5692, 6180, CV1988, CV3627, B65, ECC33, CV2821, ECC32, CV181, QA2408 [VT 231]
  
 The are a few other close variants but the above should get some searching effectively.


----------



## Artsi

Here is small list of octal tubes that i could recommend to use with little dot.
  
 Driver octals:
 6SL7GT = VT-229     Classic type
 = CV1985
 6SL7W                    Sylvania
 6SL7WGT                Rugged version with smaller parts
 6SL7WA                  Military version
 6SL7GTB                 Lower base
 6SU7GTY                Better quality and balance? Tung-Sol
 6SU7WGT = 6188     Ruggedized and bantam construction
 ECC35                    European version with 0.4A heater
 6N9S (6H9C)           Russian
 6N9M (6H9M)          Russian mini version
 1579                      Russian, better quality?
 6N9P                     Chinese
 6N9P-T                  Chinese, better quality?
 6113                     Low microphonic?
 5691                     Better quality? 0.6A heater
  
 Power octals:
 6SN7GT = VT-231     Classic
 6SN7GTA                 More power?
 6SN7GTB                 Like -A but with faster heating
 6SN7GTY = CV1988   Better quality?
 6SN7WGTA              Ruggedized and bantam construction
 6SN7W                   Sylvania
 5692                      Better quality?
 6N8S (6H8C)           Russian
 1578                      Russian, better quality?
 6N8P                     Chinese
 6N8P-T                  Chinese, better quality?


----------



## Artsi

nic rhodes said:


> Tung Sol 6SU7GTY is a wonderful tube but look out for the 6188 also. You can also find 6188 by Sylvania / PhilipsECG at much better prices.
> 
> 6SL7GT: 6SL7GT, 5691, CV1985, 6113, 6188, ECC35, CV569 [VT 229]
> 
> ...


 
 ECC33 Gain 35, 0.4A heater. Somewhere between 6SL7GT and 6SN7GT.
 ECC32 Gain 32, 0.95A heater. Perhaps works as powertube?


----------



## Artsi

Here is visible 6N8S differences from different decades. Older has also taller base. Right one can't be made in Holland...

  
 I have 6 Russian 6N9S's and i could be hearing things, but somehow this "RADIO lampa" sounds better than the others. So if someone is going to buy cheap 6N9S i recommend to look for this. Mine have date code 12-86. Still quite not good as Tung-Sol 6SU7GTY's, but cheaper.

  
 This ebay auction is very interesting. Pair of better russian 1579. I'm trying not to bid. 
http://www.ebay.co.uk/itm/RUSSIAN-TUBES-1579-6SL7-6N9S-DOUBLE-TRIODE-TUBES-Lot-of-2-NEW-in-BOX-/151162326986


----------



## i luvmusic 2

I just receieved this 80's NOVOSIBIRSK 6N6P-i GOLD GRID TUBES and it make my MK III very very hot is this normal? The stock tube i know it make the body of MK III warn to the touch but the 6N6P-i it make it very hot.


----------



## Artsi

I had one non-working trigon 6SL7GT and its base was good for doing adapter for 12AX7 tubes.

 With this i could try to compare 6SN7GT and 6N6P-IR powertubes one day.


----------



## Audiofanboy

I just found a bit of time to listen to a full album or two with one of my two new Amperex 6922.
  
 The first one I had given a good listen to was an Amperex "USN-CEP" 6922 made in 64-52, this one is an Amperex "USN" 6922 made 62-16; same exact construction,but glass may be a little less darkened (less of the "sun glasses effect").
  
 Oddly enough, I could swear that these two tubes don't sound exactly the same. They definitely share very similar traits, but the '62 tube seems more holographic with extreme micro-detail retrieval, and a bit more warmth and body, whereas the '64 seems very extended with hard-hitting punchy bass. I think I prefer the '62 tube actually (it really sounds like the description of an Amp'ex PQ 6922 made on Joe's tube lore actually, whereas the '64 tube sounded a little drier, like Joe's impressions of the Amp'ex USN 6922...).
  
 Hopefully, I'll get a chance to know if my mind is just playing tricks on me when I test the third tube, an Amperex "USN-CEP" made 65-08. If that tube also sounds different from the '62 and similar to the '64 (8 weeks apart), then I'll know that I was right. If it sounds similar to the '62 or different from _both_ other tubes, then I'll start worrying lol.
  
 Listening with the '62 tube, it definitely has that "spooky feeling that you're in the music room the artist tried to design and record"; the '64 tubes gave me the "ultra detail everywhere in the room effect", but not the spooky real feeling.
  
 Edit: I just realized that '62 version of the tube sells for $140 _for a single_ lol. No wonder it sounds good...
 Edit 2: $170 on "premium" tube resellers... Holy Schiit...


----------



## gunnerwholelife

Guys someone should do a complete recap of all the current best tubes.If not for certain FM I would have got lost in this thread.Finally on my way to order 6hm5 and 6n6p-ir and hopefully be happy for a while.
   Also can anyone tell me if op-amp rolling affects sound ? Also is the op-amp easily swappable ? I read somewhere in this thread that LME49990 and/or OPA627AP are good options.
  
 Let me know.


----------



## MIKELAP

Here is little list of tubes and variants, that should work now with boxed little dot. List is with heater currents and amplification factors.
  
 6V tube types
  
 ECC88 6DJ8 6N23P CV5358 M3624        0.35A 33x
 E88CC 6922 CCa CV2492 CV2493 9622  0.30A 33x
 E188CC 7308 CV4108                         0.35A 33x
 E288CC 8223                                    0.47A 25X
 ECC85 6AQ8 B719 6L12                      0.44A 57X
 ECC86 6GM8 6N27P                           0.30A 14X
 ECC189 6ES8                                   0.36A 31X
 ECC804 6GA8 6/30L2                         0.30A 18X
 ECC812                                          0.44A 50X
 ECC865                                          0.44A 58X
 ECC180 6BZ7 6BQ7 6BS8 6T27           0.40A 36X
 6N2P 6CC41                                    0.34A 100X
 6BK7                                              0.45A 40X
 6BC8 6BZ8                                      0.40A 35X
 PCC88 7DJ8                                     0.30A 33X
 6AU7                                              0.30A 20X
 6AX7                                              0.30A 100X
 6BX8                                              0.40A 25X
 6CH7                                              0.40A 36X
 6DT8                                              0.30A 60X
  
  
  
 12V tube types
  
 ECC83 12AX7 B339 95-127-01 6L13 CM1        0.30A 100X
 ECC82 12AU7 B329 95-126-01 CC82E CV491  0.30A 17X
 ECC81 12AT7 B152 CC81E CV455                 0.30A 60X
 E81CC 12AT7WA CV6091 6201                     0.30A 60X
 E82CC 6189 M8136 6189W                         0.30A 17X
 E83CC 12AX7WA 6057                              0.30A 100X
 E180CC CV8431 7062                               0.40A 50X
 E181CC                                                  0.40A 32X
 ECC186 12AU7WA 7316                              0.30A 17X
 ECC802S                                                 0.30A 17X
 5751 GL5751 CK5751 CV4017                      0.35A 70X
 5814A CK5814-A                                      0.35A 17X
 5963 CV3900                                           0.30A 21X
 5965 6829                                               0.45A 47X
 6679                                                      0.30A 60x
 7025                                                      0.30A 100X
 12AD7                                                   0.45A 100X
 12DF7                                                   0.30A 100X
 6680                                                     0.30A 20X
 6211                                                     0.30A 27X
 12AZ7                                                   0.45A 60X
 12AD7                                                   0.45A 100X
 12AV7                                                   0.45A 40X
 12AY7 6N4P                                           0.30A 40X
 12DM7                                                   0.26A 100X
 12DF7                                                   0.30A 100X
 12DT7                                                   0.30A 100X
 12U7                                                     0.30A 20X
 6072                                                     0.35A 44X
 6681                                                     0.30A 100X

Edited by Artsi - 10/21/13 at 1:57pm


                                                                                                                                                                                                                                                                                                                                            


 Here is small list of octal tubes that i could recommend to use with little dot.
  
 Driver octals:
 6SL7GT = VT-229     Classic type
 = CV1985
 6SL7W                    Sylvania
 6SL7WGT                Rugged version with smaller parts
 6SL7WA                  Military version
 6SL7GTB                 Lower base
 6SU7GTY                Better quality and balance? Tung-Sol
 6SU7WGT = 6188     Ruggedized and bantam construction
 ECC35                    European version with 0.4A heater
 6N9S (6H9C)           Russian
 6N9M (6H9M)          Russian mini version
 1579                      Russian, better quality?
 6N9P                     Chinese
 6N9P-T                  Chinese, better quality?
 6113                     Low microphonic?
 5691                     Better quality? 0.6A heater
  
 Power octals:
 6SN7GT = VT-231     Classic
 6SN7GTA                 More power?
 6SN7GTB                 Like -A but with faster heating
 6SN7GTY = CV1988   Better quality?
 6SN7WGTA              Ruggedized and bantam construction
 6SN7W                   Sylvania
 5692                      Better quality?
 6N8S (6H8C)           Russian
 1578                      Russian, better quality?
 6N8P                     Chinese
 6N8P-T                  Chinese, better quality?


----------



## Artsi

Here is more of those miniatyre double triodes:
http://www.head-fi.org/t/686893/how-to-make-an-adapter-to-use-double-triode-tubes-with-little-dot-mk-ii#post_9908674


----------



## Artsi

gunnerwholelife said:


> Guys someone should do a complete recap of all the current best tubes.If not for certain FM I would have got lost in this thread.Finally on my way to order 6hm5 and 6n6p-ir and hopefully be happy for a while.
> Also can anyone tell me if op-amp rolling affects sound ? Also is the op-amp easily swappable ? I read somewhere in this thread that LME49990 and/or OPA627AP are good options.
> 
> Let me know.


 
 What is your Little Dot model? You can't do both, swapping op-amp and use 6N6P-IR's?


----------



## mordy

Hi Artsi,
  
 Since each channel in the LD MKIII is completely independent, I tried in the past to compare different tubes in each channel, as you suggest (comparing the octal 6SN7GT to the 6N6P-IR tubes).
  
 I gave up because IMHO, even though the channels are separate, there is a synergistic effect that takes place, and you don't get a true picture. However, if you could wire each channel separately to play both channels in your headphones or speakers, you could take a very good monophonic recording and compare each channel by switching from side to side.
  
 I could not figure out how to do this, but maybe you can.
  
 Playing two different tubes and turning the balance control to this side or that side did not work for me; having two tubes that are the same and switching pairs (which entails waiting for the amp to cool down) worked to differentiate different sound.


----------



## gibosi

gunnerwholelife said:


> Guys someone should do a complete recap of all the current best tubes.If not for certain FM I would have got lost in this thread.Finally on my way to order 6hm5 and 6n6p-ir and hopefully be happy for a while.
> Also can anyone tell me if op-amp rolling affects sound ? Also is the op-amp easily swappable ? I read somewhere in this thread that LME49990 and/or OPA627AP are good options.


 
  
 As others have noted, if you have power tubes, then you don't have an op-amp. The Little Dot 1+ , which I have, is a hybrid, with driver tubes and an op-amp, and therefore, rolling op-amps is possible.
  
 Regarding the best driver tubes... to get you started.... 
  
 Running two single driver tubes, I would recommend pairs of RCA 6DT6 and 6HM5 (which you have apparently already ordered).
 Running one double triode, I would recommend an Amperex Orange Globe 6DJ8 from the late 1960s (with a halo getter), and a Voshkod 6N23P from the late 1970s.


----------



## MIKELAP

Want to order an adapter 6SL7 TO 12AX7 like this one here but i noticed at bottom of page its marked 6.3 volts shouldnt it be marked 12v since its the 9pin 12ax7 thats going into my setup                  http://www.ebay.com/itm/2ps-convert-tube-socket-12AX7-12AU7-to-6SL7-6SN7-9-pin-to-8-pin-/281034346185?


----------



## gibosi

mikelap said:


> Want to order an adapter 6SL7 TO 12AX7 like this one here but i noticed at bottom of page its marked 6.3 volts shouldnt it be marked 12v since its the 9pin 12ax7 thats going into my setup                  http://www.ebay.com/itm/2ps-convert-tube-socket-12AX7-12AU7-to-6SL7-6SN7-9-pin-to-8-pin-/281034346185?


 
  
 This should work fine. I bought mine from another vendor:
  
 http://www.ebay.com/itm/320659633166?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649
  
 However, both look the same to me.
  
 And 6 volts is correct. Fortunately, the 12AX7 can be used with either 12 volt or 6 volt heaters. The Little Dot heater supply voltage is 6 volts, so we wire the 9-pin socket (by using pin 9) to run the 12AX7 on 6 volts. And since the 6SL7 is also a 6 volt tube, it works flawlessly.


----------



## MIKELAP

gibosi said:


> This should work fine. I bought mine from another vendor:
> 
> http://www.ebay.com/itm/320659633166?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649
> 
> ...


 
 Thanks for the infos gibosi  if only my sockets could get here would start working on adaptors things move fast these days trying to keep up


----------



## gunnerwholelife

Guys,
   Thanks for solving the op-amp query.I am going to use the ld mkiii.
  
 I want the following tubes :-
 Mullard M8100 
 RCA 6DT6
 Voshkod 6ZH1P-EV 
 Yugi 6hm5
 6N6P-ir 
  
 Can anyone sell all of these ?
 I want to buy all from one place since I will save a lot on combine shipping and the best option is little dot users.
 I definitely want these :-
 RCA 6DT6
 Yugi 6hm5
 6n6p-ir
  
 Shipped to India.
 Let me know.


----------



## MIKELAP

gibosi said:


> Hey gibosi how much does your TUNG SOL JAN CTL 6SU7GTY go for. Thanks
> would $50.00 be reasonnable about it .It test NOS but is used


----------



## gibosi

> Hey gibosi how much does your TUNG SOL JAN CTL 6SU7GTY go for. Thanks would $50.00 be reasonnable about it


 
  
 I gave more than $50 for mine. And looking at what's available on eBay, this is the lowest price available at this time.


----------



## MIKELAP

gibosi said:


> I gave more than $50 for mine. And looking at what's available on eBay, this is the lowest price available at this time.


 
 One last thing if theres a good octal tube to buy would this be it or theres better also is there a difference in contruction if its clear glass or black .Thanks


----------



## gibosi

Since the Amperex OG with halo getters could be considered a "reference" tube, I decided to pick one up and found one for $13, manufactured in 1967. With that, configured the amp to play 6DJ8 and began listening. I now understand AFB's observations regarding the US-Amperex 6922 (1964) and the OG. While lacking the ultra detail of the 6922, I feel that the OG is more enjoyable. Moreover, I prefer it over both the Tesla and Valvo (Hamburg) E88CC.
  
 Next, I decided to roll in the Voskhod (1978) 6N23P, as I hadn't heard it recently. The Voskhod has a sonic signature quite similar to the OG, with a lush, almost warm mid range, but a bit more bass presence and punch, and excellent flow and liquidity. Moreover, the Voskhod's ability to resolve ultra detail is second to none. Gong through my playlist of favorite songs, I heard details that I have never heard before. This is a seriously good tube.


----------



## gibosi

mikelap said:


> One last thing if theres a good octal tube to buy would this be it or theres better also is there a difference in contruction if its clear glass or black .Thanks


 
  
 From what I have read the TUNG SOL JAN CTL 6SU7GTY is generally considered to be the best of the breed. And specifically, you want black glass, black cylindrical plates and a brown base.


----------



## Artsi

mikelap said:


> One last thing if theres a good octal tube to buy would this be it or theres better also is there a difference in contruction if its clear glass or black .Thanks


 
 From this post you see differences. Mine looks like the one from the right.
http://www.head-fi.org/t/297795/ec-zana-deux-tube-rolling-pls-share/30#post_4648721
  
 I paid my National and Heinz kaufman 6SU7GTY's 24 and 26euros.
  
 Edit: Trying to bid pairs of "better" 6SN7's, but they cost a fortune... Hope i get some made in USA's.


----------



## Audiofanboy

gibosi said:


> Since the Amperex OG with halo getters could be considered a "reference" tube, I decided to pick one up and found one for $13, manufactured in 1967. With that, configured the amp to play 6DJ8 and began listening. I now understand AFB's observations regarding the US-Amperex 6922 (1964) and the OG. While lacking the ultra detail of the 6922, I feel that the OG is more enjoyable. Moreover, I prefer it over both the Tesla and Valvo (Hamburg) E88CC.
> 
> Next, I decided to roll in the Voskhod (1978) 6N23P, as I hadn't heard it recently. The Voskhod has a sonic signature quite similar to the OG, with a lush, almost warm mid range, but a bit more bass presence and punch, and excellent flow and liquidity. Moreover, the Voskhod's ability to resolve ultra detail is second to none. Gong through my playlist of favorite songs, I heard details that I have never heard before. This is a seriously good tube.


 
  
 Nice tube right? I think the expression "killer tube" very well describes the Amperex OG. While I agree it doesn't immediately sound ultra-detailed, it really grows on you, and presents music with in a very resolving way yet delicious and musical.
  
 Still, though I had the exact same analysis you have when comparing the OG to '64 US-made Amperex 6922, I have to admit that the earlier '62 tube I've been using since yesterday has really blown my mind. Where I gave the OG a -hypothetical- 8.9/10, and the '64 US Amperex a 9/10, the '62 US Amperex is definitely a step above that, at 9.3 or 9.4/10 or something. That tube is quite amazing in its ability to throw a credible "room" at you; not music, but the whole world the artist wanted you to hear. Fascinating really. I have even more trouble doing anything else while listening to music with this tube than with the OG (and it was pretty hard to focus on work with the OG lol).


----------



## MIKELAP

Got myself a couple octals not the top of the line ones but decent i hope.Sockets should be here this week ,its been 3 weeks since i ordered will get started on adaptors  this week hopefully. and octal adaptors well thats another 3 weeks probably.


----------



## mordy

Hi,
  
 Getting nervous, all the octal tubes that are recommended are really expensive! Are there any good alternatives that are less expensive?
  
 How about the Tung Sol reissue of the 6SL7GT:
  
 http://www.ebay.com/itm/Tung-Sol-6SL7-6SL7GT-pre-amp-tubes-Reissue-NEW-/150562014374?pt=Vintage_Electronics_R2&hash=item230e3204a6
  
 and the Chinese Shuguang 6N9P:
  
 http://www.ebay.com/itm/Tung-Sol-6SL7-6SL7GT-pre-amp-tubes-Reissue-NEW-/150562014374?pt=Vintage_Electronics_R2&hash=item230e3204a6
  
 Should I just get the Russian 6N9S Saratov tube:
  
 http://www.ebay.com/itm/6N9S-Saratov-Made-TUBES-MATCHED-PAIR-NOS-in-BOX-6SL7-/350821836762?pt=Vintage_Electronics_R2&hash=item51ae9c67da
  
 Anybody has experience with these?


----------



## Ctritical Bill

Long time follower of this thread so about time I made a contribution.
  

  
 Whilst everyone is moving on to larger tubes I thought I would go in the other direction.
 This is a sub-miniature russian 6N16B-E dual triode.
  

  
 So how does it sound ? Well, I have had it running for less than an hour but first impressions are very good - sweet, sparkly highs and punchy bass, good detail, big soundstage and overall very smooth sounding. Much better than an RCA 6BQ7A which I tried in this setup before, which although very detailed started to sound harsh with further listening.


----------



## TrollDragon

Nice! 
I had a look at and pondered those sub mini dual's... Good to see someone using them!


----------



## mordy

Hi Ctritical Bill,
  
  
 I have seen these sub miniature tubes mentioned, and I am happy to see somebody trying them. Seems that bigger is more expensive when it comes to tubes, and these are not that expensive and usually come in lots of 4 or 8.
  
 Could not find 6N16B-E on Ebay, but 6N16V, 6N16B-I, 6N16B-VI, 6N16B-VR, and 6N16B-Q. The VR is supposed to last 2000 hours. Would you know what these tube designations correspond to? Are there other types that  would work in the LD MKIII?
  
 From your picture it looks like you are using it as a driver tube, but some of the Ebay posts list them as 6SN7 equivalents, which would indicate a power tube.
  
 How do you know which lead is which? How do you wire them? Same way as octals?
  
 Could you elaborate on your flying tube set-up?
  
 Hope you don't mind the questions.....


----------



## Ctritical Bill

mordy said:


> Hi Ctritical Bill,
> 
> 
> I have seen these sub miniature tubes mentioned, and I am happy to see somebody trying them. Seems that bigger is more expensive when it comes to tubes, and these are not that expensive and usually come in lots of 4 or 8.
> ...


 
  
 I am not an expert on russian tube designations but I will share what I have seen elsewhere. E means extended life, usually 5000hrs. V means military. I is for pulse oparation. Never come across Q.
 I have looked at quite a few different russian sub-miniatures as well as some of the american ones. There aren't many that are suitable for one reason or another. This is what I noted down while looking for suitable russian tubes :
 Subminiature triodes :
 6S7B - 5 leads - single triode 250v plate
 6S31B - 8 leads - single triode 50v plate
 6S32B - 10 leads - single triode 200v plate
 6N21B - 10 leads - twin triode 200v plate
 6N16B - 8 leads - twin triode 100v plate - most suitable
 6N17B - 8 leads - twin triode 200v plate
 6N28B - 10 leads - twin triode 50V plate
 6N33B - 6 leads - twin triode 100v plate
  
 The plate voltage is important because it has to be within the range that the LD uses. I haven't been able to measure the actual voltage yet but taking the well known 6Zh1P as my example, that operates ideally around 120v, I looked to get close to that. Looking at datasheets is the thing to do.
  
 Yes, I am using it as a driver tube but, with the right setup, it could be used as a power tube.
  
 The most difficult part was identifying the pins and wiring it up, eveything is so small. The datasheet shows the pin outs but identifying the actual pin numbers wasn't clear. I found on the base of the tube, embedded in the glass, a simple line 'l' which lines up with pin 1. Just a case of following the datasheet from there :
  
 9 pin socket         tube wire
   1                         5
   2                         3
   3                         2
   4                         4 (or 8 - heater)
   5                         8 ( or 4)
   6                         1
   7                         7
   8                         6
   9                         no connection
  
 I used a 9 pin socket saver and soldered the wires onto suitable sized pins pushed into the socket saver.


----------



## Artsi

Here is link to list of different sub-minis. I think none of them has enough power to use as powertube.
home.netcom.com/~wa2ise/radios/penciltubes.html


----------



## gunnerwholelife

Guys is this a good version of 6n6p ?
http://m.ebay.com/itm/261261824230?nav=SEARCH&sbk=1
Can't afford 6n6p-ir right now.getting 6n6p.
Let me if you guys get a better deal.
Ordering tonight so reply soon !


----------



## TrollDragon

gunnerwholelife said:


> Guys is this a good version of 6n6p ?
> http://m.ebay.com/itm/261261824230?nav=SEARCH&sbk=1
> Can't afford 6n6p-ir right now.getting 6n6p.
> Let me if you guys get a better deal.
> Ordering tonight so reply soon !


Why are you switching out the power tubes? Are not those ones you linked similar quality or less to the stock tubes that come with the MK III, or do you just want them as spares?


----------



## gibosi

mordy said:


> Getting nervous, all the octal tubes that are recommended are really expensive! Are there any good alternatives that are less expensive?


 
  
 It seems to me that there is considerable consensus the Tung-Sol JAN CTL 6SU7GTY is the best of the best in this tube family. And yes, these are expensive, but no where near as expensive as some of the 6DJ8s. To my way of thinking, rather than spend $50 on a bunch of octals of questionable quality, I would rather spend $50 to get the best of the best and be done. So I purchased the Tung-Sol and I have absolutely no plans to purchase another 6SL7 or 6SU7.
  
 I wish I could say the same about the 6DJ8 family....lol


----------



## Artsi

Got today 3 Ken-Rad 6SL7GT's. They all have different plates. Silver, matt silver and charcoal.

 According to this post these should be second best sounding octal drivers. http://www.head-fi.org/t/100774/top-5-6sn7-s#post_1176885 Could one of these say something to mighty 6SU7GTY...


----------



## mordy

Hi Artsi,
  
 Found this post below, which represents somebody's thoughts on the best TS 6SL7GTY. BTW, do you have one from 1951?
  
  
 "I have given this type some notice in other threads from time to time, but I think it deserves more attention, since it isn't nearly so well known as its most common electrical near-equivalent, the 6SL7GT.

 I've been using it in projects since 1967, and it was always Big B's front end tube (five of them in the current version). These are the three in the power amp chassis front end. Two of them ordinarily wear homebrew copper tube shields.







 The 6SU7GTY is one of several Tung-Sol proprietary winners. The familiar 5881 and 6550 are two other Tung-Sol winners, and two that made it into manufacture by other companies. Tung-Sol took the 6SU7GTY through several marks and construction styles, but apparently no other company picked it up. The closest thing to it, so far as I can see, is the 5691.

 In fact, the Hytron 5691 shown in this view appears to be a duplicate, and I think it's a rebranded/relabeled 6SU7GTY (1951 mark).






 The 6SL7WGT (Sylvania) is probably the next closest equivalent, and two of those, with their brown bases, can be seen in the view above, in the rear row of tubes behind the 6SU7 trio.

 Over the years, I've come to believe that the 6SU7GTY is to the 6SL7GT what the 7025 is to the 12AX7. In fact, I think it's not an exaggeration to call it "the octal 7025."

 It features a low-loss micanol base (this helps improve the noise and signal loss factor). It carries Aquadag electrostatic shielding on the inside of the bulb. It is also tested with AC on the heaters for a low hum-and-noise characteristic, and it is tested for balance between its two triodes.

 I first got acquainted with this tube during high-school years, via my former boss, on whose bench I had apprenticed for two junior-high summer seasons. He was an old Signal Corps vet, and he had many boxes full of WWII surplus tubes (wish I had them now! 
	

	
	
		
		

		
		
	


	




). A number of these 6SU7's were among them. I was able to get half a dozen to start with, and I built my first project with these tubes in 1967.

 Since then, I have experimented with several marks of this tube (from World War II vintage through the late 1950's) over the years, but the mark you see here (1951 vintage) is far and away the best-performing version I have encountered.

 It is somewhat microphonic if the micas are not snug against the glass, but earlier and later marks can be far worse.

 They also tend to show up much worse for hum and noise. The 1951 mark seems much slower on average to develop heater-cathode leakage than other production runs (some later 1950's editions developed it fairly quickly!).

 In this 1951 mark, it seems, they got everything as good as it gets with this type:






 For some years, these weren't hard to find, and they weren't pricier than ordinary 6SL7's. I found a number of them at RARSfest in the late 1970's, and got several more from Fair Radio at about the same time. Since then, I've been lucky enough to find a few, here and there, in mil-surplus lots that turned up at RARSfest and elsewhere. About 15 years ago, I found and snapped up a huge batch of those Hytron 5691 tubes that appear to be (and act like) rebranded 1951-mark 6SU7 tubes, going for next to nothing at Durhamfest.

 These days, of course, things have changed. These tubes have been "discovered," as one look at any mark-1951 6SU7GTY's on "that auction site" will show you (the asking prices are egregious these days!) 
	

	
	
		
		

		
		
	


	




 . I'm just glad I discovered this tube when I did, and stocked up on it long ago.

 Guys with large lots of mil-surplus tubes should search them for this type, especially the 1951 mark. If you find any, treasure them and put them to work if you can, for you have some cherries that are definitely worth attention."


----------



## mordy

Hi Ctritical Bill,
  
 Thanks for your detailed post.
  
 The Q version comes from China. Based on previous experience, the VR tube should be the highest quality.
  
 If I understand correctly, only one tube on the list is directly compatible with LDIII.


----------



## Artsi

mordy said:


> Hi Artsi,
> 
> Found this post below, which represents somebody's thoughts on the best TS 6SL7GTY. BTW, do you have one from 1951?


 
 I can't see any date codes etc on tubes or boxes. Otherwise top mica and all i can see looks to be like same like 1951 model.


----------



## gibosi

mordy said:


> Found this post below, which represents somebody's thoughts on the best TS 6SL7GTY. BTW, do you have one from 1951?


 
  
 Mine was manufactured in 1950, week 47, which is the week of November 19 - 25. Perhaps close enough.


----------



## hypnos1

gibosi said:


> Since the Amperex OG with halo getters could be considered a "reference" tube, I decided to pick one up and found one for $13, manufactured in 1967. With that, configured the amp to play 6DJ8 and began listening. I now understand AFB's observations regarding the US-Amperex 6922 (1964) and the OG. While lacking the ultra detail of the 6922, I feel that the OG is more enjoyable. Moreover, I prefer it over both the Tesla and Valvo (Hamburg) E88CC.
> 
> Next, I decided to roll in the Voskhod (1978) 6N23P, as I hadn't heard it recently. The Voskhod has a sonic signature quite similar to the OG, with a lush, almost warm mid range, but a bit more bass presence and punch, and excellent flow and liquidity. Moreover, the Voskhod's ability to resolve ultra detail is second to none. Gong through my playlist of favorite songs, I heard details that I have never heard before. This is a seriously good tube.


 
  
 Hi G.
  
 Interesting to note your preferences over the Tesla E88CC (gold pins & gold grids, I believe), especially as they are reputedly equal to the almighty Telefunken variant - in what are they lacking? Did you give them a good burn-in?
 Am especially interested as 1: The Tesla PCC88s hammering my ears at the moment are really quite something. And 2: Am awaiting my own E88CCs, complete with gold pins and grids...hope I haven't wasted my money lol!!
  
 I recognise what you say about the Voskhods, although mine are the 6N2P-ERs - the clear detail is astounding, and the delicate finesse in the treble is especially "sweet". Methinks there is a definite 'synergy' going on with the 6H30P-DRs...
  
 But these Teslas seem to be giving MORE in general...especially with about 30+ hours on them.
  
 Cheers


----------



## gibosi

hypnos1 said:


> Interesting to note your preferences over the Tesla E88CC (gold pins & gold grids, I believe), especially as they are reputedly equal to the almighty Telefunken variant - in what are they lacking? Did you give them a good burn-in?
> Am especially interested as 1: The Tesla PCC88s hammering my ears at the moment are really quite something. And 2: Am awaiting my own E88CCs, complete with gold pins and grids...hope I haven't wasted my money lol!!
> 
> I recognise what you say about the Voskhods, although mine are the 6N2P-ERs - the clear detail is astounding, and the delicate finesse in the treble is especially "sweet". Methinks there is a definite 'synergy' going on with the 6H30P-DRs...
> ...


 
  
 Well, of course, I think this really comes down to personal preferences... While I do not have a Telefunken from the 6DJ8 family, I do have a Siemens PCC88, a Valvo (Hamburg) E88CC and the Tesla E88CC with gold pins and gold grids, and they all have a mid range characteristic of German production, which is less warm and lush than is typical of Dutch and British production. Given my ears and gear, I find that I much prefer the Amperex tonality, which is not as warm as the Mullard, but more forward and lush than my Siemens, Valvo and Tesla.
  
 As the Tesla was NOS, I burned it in for 20 hours and then compared it directly to the Valvo. Mid range and treble for these two tubes is very similar, again typical of German production, but the Valvo had more bass presence, while the Tesla sounded "thinner".  As I liked the Valvo better, I then rolled in the OG. And again, personal preference, but vocals came alive. The OG has a lushness and richness, coupled with great flow and liquidity, that I find very seductive.
  
 But as much as like the OG, I think my 1978 Voskhod 6N23P is just a bit better. And given that you can get these Voskhods for $3 to $5 each, they are a steal. You want to look for production years 1974 through 1979. 
  
  http://www.head-fi.org/t/549508/schiit-lyr-the-tube-rolling-thread/8595#post_9625620


----------



## Ctritical Bill

mordy said:


> Hi Ctritical Bill,
> 
> Thanks for your detailed post.
> 
> ...


 

 Yes, I found the Q version a little later, supposed to be 'space grade' but still Chinese...
 The others on my list may work but for my first try I selected the most suitable. There seem to be lots of american ones to choose from, all appear to be high quality. I would try some of those but shipping from America to this corner of the world has become too expensive.
 On further listening to my 6N16B I am liking them more and more.
 Next I would like to try a pair of single triodes that I could mount directly in the sockets.
  
 These look very suitable :
 http://www.ebay.com.au/itm/271211549190?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649
 and the seller has lots of other sub-miniatures.


----------



## gibosi

A small package came today with a US-Amperex 6922, production date, February, 1961. Like my 1964 US-Amperex, this one is also labeled Beckman, and since it was not labeled Amperex, I got it for $35.00 with free shipping! Again, there are some very good deals to be had by going after relabeled tubes. 
  
 After reading AFB's observations regarding the sonic differences between his 1962 and 1964 production tubes, I am very curious to discover if my 1961 tube sounds any different....


----------



## TrollDragon

The lifetime supply of sub miniatures... 
http://www.ebay.com/itm/Raytheon-JAN-5702-WB-Stock-box-200-each-tubes-Very-Rare-tubes-NOS-New-A-/271324699266
  
 It's not the 20,000 qty sale one but what can you do...


----------



## Nic Rhodes

The best 6SU7GT I tried was the Tung Sol 1945 era. I would be facinated to try the Hytrons however (5691). I picked up a big stash of the 5692 (1961) by Hytron some 15 - 20 years ago and I am a great fan of these, even over my reds. These are much underated.
  
 on a different subject (and a 12v tube SO NOT A DIRECT SUBSTITUTE here), the 12SX7GT is another unsung hero. Only made by RCA I think.
  
 Vacuum Tube Valley had some good articles on these some 20 years ago inc 6SU7GT I think.


----------



## Audiofanboy

gibosi said:


> A small package came today with a US-Amperex 6922, production date, February, 1961. Like my 1964 US-Amperex, this one is also labeled Beckman, and since it was not labeled Amperex, I got it for $35.00 with free shipping! Again, there are some very good deals to be had by going after relabeled tubes.
> 
> After reading AFB's observations regarding the sonic differences between his 1962 and 1964 production tubes, I am very curious to discover if my 1961 tube sounds any different....


 
  
 Looking forward to your impressions, if only to know whether or not I'm just hearing things lol.
  
 Regardless, even if they turned out to sound the same as the '64s, those are fabulous tubes, that definitely won't be losing any value any time soon, and it's never a bad idea to have spares - especially at this price!
  
 Speaking of price, like gobosi's been saying, you can find those tubes fairly cheap fairly easily, even branded Amp'ex. You just won't get matched pairs or even matched date codes or production years is all. If I told you how much I paid for my two - unmatched & different years which is a good thing in my case as it allows testing different flavors - 6922, you'd find it hard to believe. Anyway, paying 3-digit figures for one of these is silly and easy to avoid, _unless_ you have a Lyr or whatnot, and need matched pairs.
  
 I have to  say that these tubes, especially the early 60's ones, are actually quite rare on ebay. I must have gotten lucky since I bumped in to two separate auctions - hence the decent prices - sold from EU countries over the span of a week without even looking that hard. I haven't really found anything else since then lol...


----------



## MIKELAP

Is $50.00 a pair a decent price for these amperex orange globe 6dj8 made in Great Britain. Test between 130/140
 Made at Mullard Blackburn factory


----------



## Audiofanboy

mikelap said:


> Is $50.00 a pair a decent price for these amperex orange globe 6dj8 made in Great Britain. Test between 130/140
> Made at Mullard Blackburn factory


 
  
 It's not a bad deal in itself, but the OG you really want are the ones made in Holland. The Mullard Great Britain ones, while good, neiter have the same tone (warmer) or absolute sound quality. Besides, I think you can get Mullard 6DJ8 or ECC88 cheaper.


----------



## gibosi

gibosi said:


> After reading AFB's observations regarding the sonic differences between his 1962 and 1964 production tubes, I am very curious to discover if my 1961 tube sounds any different....


 
  
 Yes, this 1961 US-Amperex 6922 does sound different. As AFB noted regarding his 1962 tube, it adds just a bit more warmth and body to the mid range compared to the 1964 US-Amperex 6922, which is a bit leaner and drier. And for sure, this warmer and richer presentation, with ultra detail and a holographic 3-D stage is GREAT!  Considering the 6DJ8-type tubes I have on hand, this tube is my current number one, with the 1978 Voskhod 6N23P, the 1967 OG and 1964 US-Amperex 6922 rounding out the best of the best.
  
 But of course, this is not the last word as I have a few more little bottles of heaven coming my way... albeit ever soooo slowly.... lol
  
 A physical feature on these US-Amperex 6822 tubes that I noticed yesterday: The sandblasted number 108. This appears to be the date of manufacture - 1961 Week 08, and it precisely correlates with the etched Philip's tube code number, *1B = 1961, February. The red-printed 61-46 is likely the date this tube was silk screened and packaged. I see comparable sandblasted numbers on my two 1964 tubes as well.


----------



## Artsi

gibosi said:


> You know.... it's getting harder and harder to figure out which tube I like best! lol But what a wonderful problem to have....


 
 It really is starting to be problem to sort out ranking for owned tubes. Russian "RADIO lampa" 6N9S have even got better with some more hours of usage and difference to 6SU7GTY have become narrower. 6N9S bass is still little boomier than others.
  
 6SU7GTY really does have a good sound. But i think it tries to be little too pleasing. There could be some cautiousness in sound and therefore it is not anymore my favorite tube to listen.
  
 I got those 3 different KEN-RAD 6SL7GT's. Shiny and matt silver plated ones sounded good, but just like "normal" ones. But then there was this charcoal plated Y4 (nov 1944?) date coded JAN CKR 6SL7GT VT-229 and code SC961A? Now this tube does have balls in sound. And what little i understand about terminology, then this tube really have 3D sound with airiness, clarity and micro details that i have dreamed of.
  
 I have not ordered any driver tubes after i won auction of ken-rads and not planning to buy any driver tubes for long time. (we'll see how long time i can be to not buy more of them) There is 4 pairs of very good power tubes coming from California, hope i get them in 2 weeks.


----------



## Audiofanboy

gibosi said:


> Yes, this 1961 US-Amperex 6922 does sound different. As AFB noted regarding his 1962 tube, it adds just a bit more warmth and body to the mid range compared to the 1964 US-Amperex 6922, which is a bit leaner and drier. And for sure, this warmer and richer presentation, with ultra detail and a holographic 3-D stage is GREAT!  Considering the 6DJ8-type tubes I have on hand, this tube is my current number one, with the 1978 Voskhod 6N23P, the 1967 OG and 1964 US-Amperex 6922 rounding out the best of the best.
> 
> But of course, this is not the last word as I have a few more little bottles of heaven coming my way... albeit ever soooo slowly.... lol
> 
> A physical feature on these US-Amperex 6822 tubes that I noticed yesterday: The sandblasted number 108. This appears to be the date of manufacture - 1961 Week 08, and it precisely correlates with the etched Philip's tube code number, *1B = 1961, February. The red-printed 61-46 is likely the date this tube was silk screened and packaged. I see comparable sandblasted numbers on my two 1964 tubes as well.


 
  
 Absolutely fascinating!
  
 And there I was expecting you to just invalidate my theory with some lukewarm "well... the '61s sound great, but the 64's are also excellent..." lol.
  
 Again, what I find interesting is the similarity between the comments on Joe's tube lore and my impressions of both those tubes. The '62s, in my case, I would describe the exact same way "Joe" describes a Amp'ex US white label PQ 6922, while the '64 USN-CEP tube I would describe the same way he talks about a Amp'ex USN 6922... Go figure...
  
 Still, I find that the expected minute difference actually makes a hell of difference during listening. While the '64 was great, realistic and detailed, I _quickly_ felt the need to switch back to the OG, despite it being ever so slightly less detailed. There was no such pattern with the '62 tube. I've been running it since I put it on my amplifier. Color me surprised...
  
 All in all, how would you rate the '61 US 6922 Amperex compared to the best 6SL7 offering - that Tung Sol tube? Having gotten close to the top on the 6DJ8 family (below $200 a tube at any rate), I'm curious as to what else the world has to offer (though I have 10000 hours of listening pleasure ahead of me with the '62 Amp'ex if I wish lol).


----------



## mordy

Hi Artsi,
  
 Does your favorite tube look like this one?


----------



## gibosi

audiofanboy said:


> Again, what I find interesting is the similarity between the comments on Joe's tube lore and my impressions of both those tubes. The '62s, in my case, I would describe the exact same way "Joe" describes a Amp'ex US white label PQ 6922, while the '64 USN-CEP tube I would describe the same way he talks about a Amp'ex USN 6922... Go figure...
> 
> Still, I find that the expected minute difference actually makes a hell of difference during listening. While the '64 was great, realistic and detailed, I _quickly_ felt the need to switch back to the OG, despite it being ever so slightly less detailed. There was no such pattern with the '62 tube. I've been running it since I put it on my amplifier. Color me surprised...
> 
> All in all, how would you rate the '61 US 6922 Amperex compared to the best 6SL7 offering - that Tung Sol tube? Having gotten close to the top on the 6DJ8 family (below $200 a tube at any rate), I'm curious as to what else the world has to offer (though I have 10000 hours of listening pleasure ahead of me with the '62 Amp'ex if I wish lol).


 
  
 Unfortunately, in Joe's descriptions, he didn't provide the date of manufacture for these tubes, but focused primarily on the silk screening - color, text and graphics. However, I have to believe that his Amperex US white label PQ was manufactured sometime around 1961-62, and his Amperex US white label USN was manufactured sometime around 1964. As all my tubes carry the Beckman label, his physical descriptions based on silk screening are of no use at all.... 
  
 And I had the same experience with the lean and dry 1964 tube, never leaving it in the amp for any length of time in favor of the Voskhod 6N23P and the Sylvania 5751 TMBP. But now with the '61, I absolutely do not want to take it out! lol But yes, I need to roll the Tung Sol 6SU7 and Sylvania 5751 again to see how they stack up. Plus I have a 1975 Voshkod, Heerlen E188CC and French E88CC on the way.... Life is good.


----------



## MIKELAP

Like Sil would say ¨When i tougth i was out ,they pullll me back in ! ¨


----------



## Artsi

mordy said:


> Hi Artsi,
> 
> Does your favorite tube look like this one?


 
 Otherwise yes and without bottom mica's "bumpers". Stamp is different. Mine has stamps like this without bottom bumpers. http://www.ebay.co.uk/itm/RARE-Matched-Pair-Ken-Rad-CKR-6SL7GT-VT-229-ECC35-tubes-Foil-getter-/171046481705


----------



## mordy

Hi Gibosi,
  
  
  
 "I think my 1978 Voskhod 6N23P is just a bit better. And given that you can get these Voskhods for $3 to $5 each, they are a steal. You want to look for production years 1974 through 1979.
  
  
 Could you give me a link where I can buy these tubes at the prices you quote?


----------



## gibosi

mordy said:


> "I think my 1978 Voskhod 6N23P is just a bit better. And given that you can get these Voskhods for $3 to $5 each, they are a steal. You want to look for production years 1974 through 1979."
> 
> Could you give me a link where I can buy these tubes at the prices you quote?


 
  
 My strategy:
  
 Every day I searched world wide for newly listed 6N23P. Quite often, there would be 4 or 8 or 20 tubes listed. I then sent an email to the vendor asking if he had a pair of 1975 Voskhod 6N23P, for example. This particular year seems to be quite hard to find, so usually, the answer was no. However, in one instance, the vendor had 8 tubes for $40, and in his email, he told me that the lot included one pair of 1975, one pair of 1976 and two pairs of 1978. So I grabbed them:
  
 http://www.ebay.com/itm/131044830184?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649
  
 In another instance, the vendor had 20 tubes. I told him I was looking for a pair of 1977 and a pair of 1975. He replied that he had two 1977 and one 1975. We agreed on a price and he created a special auction with these three tubes:
  
 http://www.ebay.com/itm/321249178270?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649
  
 I hope to have these later this week or early next......
  
 So it is not all that hard....  Search every day, and ask every vendor who lists a bunch of Voskhods if he has the years you want.


----------



## MIKELAP

Got my octals today would anybody know the date of these tubes.Thanks.


----------



## mordy

The bottom picture TS: 37th week 1961


----------



## Oskari

mordy said:


> The bottom picture TS: 37th week 1961


 
  
 That's right.
  
 Did the Sylvania tube come with a box?


----------



## MIKELAP

oskari said:


> That's right.
> 
> Did the Sylvania tube come with a box?


 
 No.


----------



## Oskari

The codes on the tube don't tell me much, I'm afraid. Sylvania date codes are poorly understood.
  
 Perhaps E4 = May 19?4, perhaps not.
  
 SC A = U.S. Army Signal Corps.
  
 966 = ?


----------



## siles1991

Wow i've been gone for awhile and tube rolling has gone to a new dimension O_O I don't think I have the guts to pull off all those mods as I have very little electronic knowledge and would break down in tears if anything happened to my LD D: Still using the RCA 6DT6A's and these are still my favorite among all the tubes i've used. Though I don't want to believe this is the limit xD any new recommendations that don't require the hardmods you guys are doing  like the ol fashion strapping!


----------



## Audiofanboy

siles1991 said:


> Wow i've been gone for awhile and tube rolling has gone to a new dimension O_O I don't think I have the guts to pull off all those mods as I have very little electronic knowledge and would break down in tears if anything happened to my LD D: Still using the RCA 6DT6A's and these are still my favorite among all the tubes i've used. Though I don't want to believe this is the limit xD any new recommendations that don't require the hardmods you guys are doing  like the ol fashion strapping!


 
  
 Yeah, we don't muck around on this thread lol!
  
 Still, I can personally vouch for how _colossal_ the improvement is with these premium double triodes; it _really _is worth the extra effort.
  
 Again, all you need is:
 - Two 7-pin socket savers/testers
 - One 9-pin socket or a 9-pin "breadboard"
 - 20~50cm / 8~20" copper wire
 - And either some basic soldering skills or some way of safely strapping those wires.
  
 Honestly, if you plan your basic DIY adapter well, it is pretty easy to make. Some adapters (gibosi's for example, I believe) may not even need any soldering at all; so you wouldn't even need to "make", you could just "build". Easy, I tell you.
  
 All the cool kids are running double triodes lol, it would be a shame to be left out! (I'm just kidding, but what I wrote above is still true)


----------



## Artsi

mikelap said:


> Got my octals today would anybody know the date of these tubes.Thanks.
> 
> 
> 
> ...


----------



## gibosi

gibosi said:


> ......I need to roll the Tung Sol 6SU7 and Sylvania 5751 again to see how they stack up......


 
  
 I took some time this evening to compare the 1961 US-Amperex 6922, the late 1950s Sylvania 5751 TMBP (Triple Mica Black Plates) and the 1950 Tung-Sol JAN-CTL-6SU7GTY....
  
 The Sylvania has a tonality very similar to the 6922 with a superb mid range and treble. However, while the sound stage with the Amperex is exquisitely sharp and focused, it is noticeably softer with the Sylvania. And similarly, with the Amperex, micro details seem to be sharply etched against a very black background, whereas they were noticeably softer and less focused with the Sylvania. In my opinion, the Sylvania compares quite well with the Amperex OG. That said, one Sylvania typically sells for around $60 while a pair of OGs can often be found around $30. Given that, I suggest that you pass on the Sylvania and enjoy your OG. 
  
 The Tung-Sol is a bit more complicated.... It is quite warm, with very good clarity and transparency, and a nice 3-D soundstage. However, the upper mid range and treble response is rather laid back. Thus, micro details, which tend to be in this frequency range, are also somewhat faint. My feeling is that this tube is just not a good match for my HE-300s, which are rather dark. However, I would love to listen to this tube through a pair of HD-800s. My gut tells me this just might be a very good pairing. And further, it occurs to me that perhaps a different 6SL7/6SU7 would sound better in my current system.
  
 So.....  even though I wrote very recently that I did not intend to purchase any more octals, I have decided to get one more. lol 
  
 In 2006, a guy with the handle Sir.Richard wrote that in his opinion, the Sylvania 6SL7WGT Gold (JAN-CHS-6SL7WGT) was the best of the breed. Of particular interest to me is this comment:
  
 ".......puts you front and centre - like the main instruments are just a couple of feet ahead of you -
 forward of the speakers. Excellent depth and detail and solo instruments and classical music just
 come alive. A real eye opener when you listen to these." 
  
 http://www.head-fi.org/t/100774/top-5-6sn7-s#post_2011240
  
 It seems quite likely that this Sylvania has a very different sound signature, perhaps a better match for my headphones, and so earlier today, I purchased one.


----------



## mordy

Hi All,
  
 Completely agree with AFB - there is so much more listening pleasure to be had with the double triodes such as the 6DJ8 and 12AX7 families.
  
 As somebody who does not have much experience in electronics I took the plunge and made different adapters. After trial and error Gibosi's no solder adapter is probably the best and easiest solution.
  
 I got an adapter that allows an octal tube to be plugged into a 9 pin socket wired for 12AX7. Hopefully I'll have an octal tube soon to play with with.
  
 What's next? Sub miniature tubes?


----------



## TrollDragon

Picked these up tonight from a local seller on kijiji for a great price.
  
 Sylvania JAN 5751 8039 & 792?, Unfortunately they are not TMBP's but they sound good so far, he had some black plate RCA's in his mono blocks...

  
  
  
 He also gave me a pair of these as one is a little noisy... I forgot what he said they were I'll have to ask him again, they are some kind of 12A?7.
 Shorter plates than the 5751's,  no number on the tube and the "GE Electronic TUBE" is painted on in a raised green enamel.
 He felt they were fakes of some sort...


----------



## MIKELAP

artsi said:


> mikelap said:
> 
> 
> > Got my octals today would anybody know the date of these tubes.Thanks.
> ...


 
 Thanks Artsi, might i ask what is the price it sold for i paid $19.00 including shipping !


----------



## Artsi

mikelap said:


> Thanks Artsi, might i ask what is the price it sold for i paid $19.00 including shipping !


 
 It was auction of 3 sylvanias. One NOS, one little used and one more used. It was about 50dollars with shipping.


----------



## Audiofanboy

gibosi said:


> I took some time this evening to compare the 1961 US-Amperex 6922, the late 1950s Sylvania 5751 TMBP (Triple Mica Black Plates) and the 1950 Tung-Sol JAN-CTL-6SU7GTY....
> 
> The Sylvania has a tonality very similar to the 6922 with a superb mid range and treble. However, while the sound stage with the Amperex is exquisitely sharp and focused, it is noticeably softer with the Sylvania. And similarly, with the Amperex, micro details seem to be sharply etched against a very black background, whereas they were noticeably softer and less focused with the Sylvania. In my opinion, the Sylvania compares quite well with the Amperex OG. That said, one Sylvania typically sells for around $60 while a pair of OGs can often be found around $30. Given that, I suggest that you pass on the Sylvania and enjoy your OG.
> 
> ...


 
  
 I'm not particularly surprised that a "Top 10" 6DJ8 tube would turn out to sound better than a good 12Ax7 variant. The 6DJ8 (and even moreso the 6922) was developed fairly late in the tube era and made for pretty critical/precise applications (the fact that Tektronix used this tube as their "staple signal triode" of sorts kind of confirms it for me, as we all know Tek did not fool around when picking tubes).
  
 The 6Sx7 tubes, on the other hand, I can't make any assumptions about. Some are propbably crap, some are still considered to be some of the best signal tubes ever made. Still, while the best 6SL7 are the older WW2 era ones, the premium 6DJ8 tubes should have at least somewhat benefited of the extra 20 years of research (I just can't believe that all those engineers and scientists weren't doing anything for all that time; I mean the whole "frame grid" must have made some change in sound quality when implemented well...). So, I would expect a "top tier" 6922 to at least hold its own ground against even a "god tier" 6SL7; hell, maybe even sound as good or better (just as linear and cleaner perhaps).
  
 Looking desperately all over the web for detached and pragmatic answers to "which double triode is best suited for gain preamps" and "which double triode family are the best double triodes tubes found in" and other questions, I find myself overwhelmed by how _little_ people seem to have compared those tube types (or reported on their findings). I guess people normally just stick to what their amp uses... Just goes to show how unique we are lol!
  
 Interestingly, one result that popped up a few times, when I was looking for direct comparisons of "top tier" 6922, 6Sx7 & 12Ax7 double triodes, is the suitability of the 6N30 family for this exact application, and how good these tubes were made to be, both on paper and in real world use. I'd read stuff before about how "perfect" the NOS 6N30 tubes were supposed to be in theory, but reading it again in a different context at least comforts me in my choice of power tubes lol.
  
 While the 6N30 could make a excellent driver tube, it probably wouldn't be suited for our amps though (if even leaving the heater power aside), as they output a _lot_ of current, and unless used in appropriate preamps, would not be well suited for a gain stage (low mu, extreme gm). On the opposite, The 6DJ8/6922 are very well suited for a gain stage for a similar reason though, as they have medium gain and output a lot of current too (a third of a 6N30 though lol).
  
 Anyway, still looking for as many impressions as possible comparing the best 6SL7 and 6DJ8 tubes. This time around though, I'm really thinking I hit a new sound quality plateau with the '62 US 6922 that might be hard to beat. This Amperex tube is simply... gorgeous to listen to... I've never heard bass guitar or drums that captivate me that much. It's not missing anything... Simply astounding.


----------



## MIKELAP

How would the new 6922 by Genelec or other manufacturers compare to the old ones any idea.


----------



## hypnos1

mikelap said:


> How would the new 6922 by Genelec or other manufacturers compare to the old ones any idea.


 
  
 Hi Mikelap.
  
 Don't know if this is of any help, but I would suspect the much later ones - compared to what AFB and Gibosi have been lucky enough to find - are not in the same league. This from what I personally have gleaned from various sites, and my (limited) experience with the Philips ECG 6922 JAN ('80s), and a pair of Zaerix tubes that are EXACTLY identical...they don't come anywhere near even the dirt-cheap (but excellent) Voskhod 6N23P (see Gibosi's comments on same) or my 6N2P-ERs. But of course there are OTHER 6922s!!


----------



## TrollDragon

mikelap said:


> How would the new 6922 by Genelec or other manufacturers compare to the old ones any idea.


 
 There has to be possibly something  good about the new tubes...
  
 The guy I picked up the 5751's last night from has a nice little collection of tube gear.
  
 A sweet little 18W monoblock pair that I forget the name of with a quad of new Svetlana 6L6CG's. A Prima Luna Prologue Classic with new EL34's and 2 phono stages, a Grant Fidelity p-307 and a Jolida JD9 MK II... This gear run's vintage Magnepan type speakers and most of the units have new not NOS tubes in them. 
  
 So there has to be something to be said about new stock instead of chasing vintage tubes around, or it is possible that he just does not have the time or the bother to search for and acquire NOS tubes...


----------



## hypnos1

gibosi said:


> Well, of course, I think this really comes down to personal preferences... While I do not have a Telefunken from the 6DJ8 family, I do have a Siemens PCC88, a Valvo (Hamburg) E88CC and the Tesla E88CC with gold pins and gold grids, and they all have a mid range characteristic of German production, which is less warm and lush than is typical of Dutch and British production. Given my ears and gear, I find that I much prefer the Amperex tonality, which is not as warm as the Mullard, but more forward and lush than my Siemens, Valvo and Tesla.
> 
> As the Tesla was NOS, I burned it in for 20 hours and then compared it directly to the Valvo. Mid range and treble for these two tubes is very similar, again typical of German production, but the Valvo had more bass presence, while the Tesla sounded "thinner".  As I liked the Valvo better, I then rolled in the OG. And again, personal preference, but vocals came alive. The OG has a lushness and richness, coupled with great flow and liquidity, that I find very seductive.
> 
> ...


 
  
 Have finally popped in the 6N23Ps ('73 &'74 with grey shields, so am hoping they might match the '75s) and WOW, you weren't kidding Gibosi. For the money, there is no equal to be sure - in fact outperform most tubes many times more expensive. And this is with just a couple of hours on them! Can't wait to get some more time on 'em and do a proper comparison with the 6N2P-ERs - first impressions are that the bass seems more extended; more to the mids, with not _quite_ the same breadth of soundstage - but that may well open further with time...All in all I can see why you have them (almost!) at the top of your list. (Have some '70s 6N2P-ERs on the way which I am looking forward to seeing if they can put up an even better battle...).
  
 As I mentioned in my post to mikelap, these Voskhods are WAY ahead of the likes of Philips ECG 6922s and even the Mullard E88CCs with gold pins - good though the Mullards are, for my taste there just isn't the same spacious 'airiness' or pinpoint separation : too 'warm' I suppose, which seems to close in the sound. But for those who prefer 'warmth' they certainly are a good tube...
  
 The Telefunken ECC88s...now here's a dilemma. Germanic 'flavour' - yes, but with a bit more body than the Teslas. I really want to love these tubes, but have a feeling they aren't delivering of their best - one is pristine the other not quite so, with less clear glass; slightly 'smoky' inside and pins that show much more usage...obviously NOT a good match. Ah well, my turn to get unlucky...
 Still, all is not lost - have another pair on the way, so should be able to get at least 2 well-matched set of triodes, given my adapter set-up (will be making 2 more so that 3 decent (hopefully) tubes will give me 12 possible combinations). I have a feeling I could be in for a very pleasant surprise in the near future, given the number of positive murmurings from around the 'net re the plain 'vanilla' ECC88s compared to the _uber_ expensive TFK tubes...can but just hope...
  
 At the moment, though, I am really enjoying these 6N23Ps caressing my ears...


----------



## mkrzych

Amazing guide!


----------



## hypnos1

mkrzych said:


> Amazing guide!


 

 Hi mk.
  
 Hope you've been able to keep up with the lightning-fast progress of recent times! Who would have thought the humble LD could reach such heights?...Long may it continue. But surely we must be reaching the outer limits of what is achievable? Every time I think we have, another milestone comes along - what a great bunch of guys on this thread!!


----------



## Ctritical Bill

For my next adventure in sub-miniature land ............
  

  
  
 These are Raytheon CK5702 pentodes.
  

  
 These work like all the regular pentodes we used to use. EF95 setting and I manually tied grid 3 to the cathode.
 Initial impressions are that it sounds similar to the 6N16B twin triode I tried before. That is clear, forward mids that make vocals sound very good, sparkly highs, well defined soundstage, and all-round very smooth sounding.


----------



## gibosi

gibosi said:


> In 2006, a guy with the handle Sir.Richard wrote that in his opinion, the Sylvania 6SL7WGT Gold (JAN-CHS-6SL7WGT) was the best of the breed. Of particular interest to me is this comment:
> 
> ".......puts you front and centre - like the main instruments are just a couple of feet ahead of you -
> forward of the speakers. Excellent depth and detail and solo instruments and classical music just
> ...


 
  
 This is much better! 
  
 Sylvania Gold Brand - black plates, brown base, gold print (faded to white?) on tube, D-getter with top getter splash. There are no discernable date codes, but it appears safe to assume 1950s.
  





  
 It was listed as NOS, so figure I need to burn it in before coming to any real conclusions. But my initial impressions are positive. From Sir.Richard's description above, I was a little concerned that this Sylvania might be too bright, but to my ears, the tonality seems about right, brighter than the Tung Sol, but definitely not too bright. I am not hearing anything I don't like, but it is too soon to say just how good it is.....
  
 Edit: To clarify...
  
 Sylvania 6SL7WGT Gold Brand was the consumer version and JAN-CHS-6SL7WGT was the military version - they appear to be same tube.....


----------



## gibosi

Re: Sylvania GB-6SL7WGT / JAN-CHS-6SL7WGT plus some observations regarding octals and 9-pin miniatures....
  
 I now have three octal double triodes, two Tung-Sol and one Sylvania, and in my mind, what really distinguishes these from the 9-pin double triodes is the bass. These octals have noticeably more bass presence. Kick drums are reproduced with considerable weight and punch. And the bass is also quite warm and wet, in the sense that reverberation creates the sensation of being in an enclosed performance space. This reminds me a bit of the difference between bass-reflex and acoustic-suspension loud speakers. Bass-reflex speakers typically produce more volume, but acoustic-suspension speakers often can provide more detail and sub-bass. In the end, neither of these designs bests the other in every category, and "best" is typically a matter of personal preference.
  
 The Sylvanias feel to me like a good bass-reflex speaker system. The enhanced bass creates a sound that is enveloping and quite pleasant. Further, although I have not had a chance to compare it directly with the best of the 6DJ8, the Sylvanias are very quiet and have a nice 3-D sound stage, with good detail. Admittedly, I have not been able to spend a lot of time with this tube, but I am very impressed with it so far, and I would be interested to hear what others think.


----------



## hypnos1

Back to 6DJ8/ECC88 land...
  
 Methinks I may have found a fierce competitor to the amazing Voskhod 6N23P - the Telefunken ECC88. At first I thought the bass not _quite _as hard-hitting, but later realised it was in fact giving a good bit more _detail - _more than I have ever encountered before, and I just love it. The high detail is also present throughout the other frequencies, and the soundstage is truly all-encompassing. As more tracks of Genesis/Duke are hitting my ears, it's getting harder and harder to concentrate on this post - that happens only VERY rarely, and hasn't for some time now...I think that must speak volumes - for me at least. I actually believe I may have (this time!) finally found my Nirvana. For everything to be sounding 'together' in such a way without the need for further analysis is almost making me cry - and I don't even care if that makes me sound naff!! All I can hope is that you all manage to find tubes that elicit the same response on such a deep (emotional) level...and that's from someone who is a natural-born analytical pessimist!
  
 Enough already...time for tea, and a break from all this emotion - am not used to it!!
  
 Happy rolling, everyone.


----------



## gibosi

Re: 1950s Tung-Sol JAN-CTL-6SU7GTY and Sylvania GB-6SL7WGT / JAN-CHS-6SL7WGT
  
 I have been listening to both of these octals this evening, and they are much more similar than I originally thought. I now realize that these octals need more gain than the 6DJ8 and 5751. That is, if you set your LD at 12 o'clock for 6DJ8s, you will need to set it at around 1 or 2 o'clock to achieve a similar volume with these octals. The other day, when comparing the Tung-Sol to the 6DJ8 and 5751, I was mislead by the fact that the Tung-Sol's bass is stronger, and I kept the volume at the same level. And of course, in hindsight, vocals through the Tung-Sol seemed too laid back. Now, comparing the Tung Sol and the Sylvania, yes, the Sylvania is brighter than the Tung-Sol, but not by that much. So to those of you who quickly jumped in and ordered the Tung-Sol, I think you will find it to be an excellent tube. And if you have already ordered the Sylvania, it too is excellent.


----------



## mordy

Hi Hypnos1,
  
 Are these tubes them?
  
  




  
 Cost: $399.00


----------



## mordy

Exploring various 12AX7 tubes. So far tried the following Sylvanias which all should be from the early 60's: 12AX7A, 12AU7A, 12AZ7A, 12AT7, 12BY7A. Did not like any of them, except for the 12AX7A which is excellent.
  
 Next tried a Japanese 12AX7/ECC83 tube made by National/Matsushiiita. Tube looks well made with a 45 degree circular getter (tipping the hat to the Philips people? [Oskari, I looked it up, did not want to call it by the wrong name]) Sound is detailed but thin and light with weak bass - not for me:
  

  

  
 How about a modern Russian tube? But first a little information on Ruby tubes. This company is a Chinese re-brander that caters to the electric guitar crowd, and apparently many guitar players like tube amps. Ruby is a re-brander with a twist: They carefully test their tubes before they put their labels on them, in this case on the box.
 The tube I got is a Russian Sovtek 7025 /12AX7WA. Ruby calls it 12AX7AC7 HG+ which is a mouthful, so will just call it Quicksilver:
  


  
 One unusual feature is that it looks like the mica plates are made of see through Lexan plastic or something similar. The sound is pretty good, but I get the impression that it needs a very high volume to come to it's forte (think electric guitar concert). Too few hours to come to a conclusion, but maybe promising.
  
 Also waiting for my first octal tube. It almost arrived Friday, but was mistakenly sent to the next postal district for delivery, and then rerouted when the mail carrier could not find the address. Hope they don't send it back to Florida before it comes back here. Oh well.....


----------



## hypnos1

mordy said:


> Hi Hypnos1,
> 
> Are these tubes them?
> 
> ...


 
  
 Hi mordy.
  
 $399? Are you kidding?!! Mind you, it's nice to know my used ones at a fraction of the cost are in such hallowed company. NO tube is worth that kind of money in my book...
  
 But yes, they're the ones - except not enough of the writing is left to discern the date...shame. So the moral to everyone is...wait until some decent used ones come along. All I can say is the wait should be well worth it.
  
 As an update to my previous post, with further settling in (even though they are used, they really improved after several hours - perhaps the cleaned pins (not that they were badly corroded) needed the extra time) they have trounced the Voskhods. After the emotional response - which perhaps is the best judge? - my analytical side is kicking in (it needs to make sense of that emotion - leopard/spots?!)..
  
 Anyway here goes :
  
 Bass - As mentioned before, DETAILED. But add MORE extended than the Voskhods even. Tight? - Ouch! And never drowns other frequencies. Have never before felt it in my bones to this degree...
  
 Mids - All there. Wonderfully detailed, clear/clean, without the tendency to be over-'lush' as can happen with so many of the Philips group variants. Even the lower mids/upper bass of acoustic guitar (via Clannad's PastPresent) had my bones tingling...
  
 Treble - 'Scintillating' would be the first word that comes to mind (being emotional again!). OK, back to analytical : Extended; clear; massive detail/variety throughout the entire high frequency range, with a delicious decay to cymbals etc. Again, as with the bass, without imposition and no undue sibilance.
  
 Soundstage - Wide and deep; instrument separation clearly defined yet nicely integrated; vocals positioned so as to sound 'intimate' without being TOO forward - all in all wonderfully 3D, with the (for me) vital sense of 'airiness' and space.
  
 Transients - This is an area that until now I didn't really grasp or appreciate. I think I have suddenly been enlightened - if I'm right, they impart a magical ingredient to music enjoyment, viz : sudden, fleeting sounds that hit your senses and have you wondering "where on Earth did THEY come from?". I suppose it's an extension to overall detail, that otherwise would just get lost in the 'jungle' of sound. Whatever, tracks that I thought I knew well are in some cases sounding vastly different - depending, presumably, on the recording engineer's prowess...
  
 And all these elements mesh together - in a beautifully silent/clear backdrop - to a degree that seems faultless, and in a way (with my setup anyway) that far exceeds anything I have ever encountered in these past months of trying countless tubes (but not as many as others, I have to admit).
  
 Hopefully I have given a true and fair view of these particular tubes, and trust that anyone else lucky enough to find some at a reasonable cost will have a similar _eureka_ experience - mine appears to be similar to AFB and Gibosi with their early '60s Amperexes...This (seemingly) long journey has been WELL worthwhile - thank goodness!!
  
 Edit - As an added bonus, these tubes are now making my HD650s sound just as good as (the memory of) the MUCH more expensive 700s...


----------



## MIKELAP

mordy said:


> Exploring various 12AX7 tubes. So far tried the following Sylvanias which all should be from the early 60's: 12AX7A, 12AU7A, 12AZ7A, 12AT7, 12BY7A. Did not like any of them, except for the 12AX7A which is excellent.
> 
> Next tried a Japanese 12AX7/ECC83 tube made by National/Matsushiiita. Tube looks well made with a 45 degree circular getter (tipping the hat to the Philips people? [Oskari, I looked it up, did not want to call it by the wrong name]) Sound is detailed but thin and light with weak bass - not for me:
> 
> ...


 
 One of the octals i just bought as that see thru mica as well . I am not lucky also been waiting for a month for sockets from China probably wont get them i asked for a refund at this point went to fast dough i could of gotten them at PARTS CONNEXION but forgot about them a well.should get the sockets this week and get this show on the road .Got almost all my tubes waiting for orange globes.


----------



## mordy

Thought of something that may be a little crazy:
  




  
 Here is the Vector 7 pin adapter. By using two of them we can connect a 9 pin socket with a 12AX7 or 6DJ8 tube and listen to double triodes. In doing so we are using some of the numbered tabs on the adapter.
  
 What would happen if I stuck in a pair of say 6HM5 tubes in the adapters and used them *together* with a 12AX7 tube? Would the amp blow up?


----------



## gibosi

mordy said:


> Thought of something that may be a little crazy:
> 
> 
> 
> ...


 
  
 ahaha... I cannot believe that this could be anything other than BAD! But if you want to try it, please do let us know what happens!


----------



## Audiofanboy

Yeah, I'd vote for answer B here: an explosion!
  
 Hell, if you really want to try something new and different, here's an idea: let's try to use a 2C51 double triode adapted on two Vectors or the usual breadboard!
  
 Anyone have a Western Electric 396A lying around, so we can try the best tube in that family right away lol?


----------



## gibosi

I received a nice little package today....
  

  
 The tube on the right is a DARIO / RT / La Radiotechnique E88CC manufactured in the Philips-owned Mazda factory in Suresnes, France. Tube code is F7B1, so manufactured in February, 1967. And it appears that it was silk-screened and packaged in February, 1968 (6802). 
  
 And the vendor threw in a free Tesla E88CC with gold grids! What a nice surprise!


----------



## gibosi

audiofanboy said:


> Yeah, I'd vote for answer B here: an explosion!
> 
> Hell, if you really want to try something new and different, here's an idea: let's try to use a 2C51 double triode adapted on two Vectors or the usual breadboard!
> 
> Anyone have a Western Electric 396A lying around, so we can try the best tube in that family right away lol?


 
  
 Ummm... How serious are you? 6.3 volts... .3 amps....  I could certainly do this very easily with my Vector-breadboard adapter.....


----------



## mordy

Thanks Gibosi and AFB, you convinced me not to try it.
  
 Just out of curiosity, why cannot it be done? Too much current draw?


----------



## Audiofanboy

gibosi said:


> I received a nice little package today....
> 
> The tube on the right is a DARIO / RT / La Radiotechnique E88CC manufactured in the Philips-owned Mazda factory in Suresnes, France. Tube code is F7B1, so manufactured in February, 1967. And it appears that it was silk-screened and packaged in February, 1968 (6802).
> 
> And the vendor threw in a free Tesla E88CC with gold grids! What a nice surprise!


 
  
 A nice surprise indeed lol; curious as to how both tubes sound now!
  


gibosi said:


> Ummm... How serious are you? 6.3 volts... .3 amps....  I could certainly do this very easily with my Vector-breadboard adapter.....


 
  
 Actually fairly serious since the _basic_ specs seem to match pretty well, so it's worth a try. The recommended cathode bias resistor values seem a bit off though (200-240 ohms recommended for class A operation, LDs have 780 ohms if I recall), but we never used to check that anyway and many tubes still worked regardless...
  
 This tube could even be a good candidate for a paralleled use (one tube for each channel, strapped cathodes, strapped grids, strapped anodes) since it has medium gm (unlike the 6DJ8's high gm), and because of our amps' cathode bias value (maybe?). Again, bear in mind, half of this is speculation. Then, again, speculation has gotten us this far lol...


----------



## gibosi

audiofanboy said:


> Actually fairly serious since the _basic_ specs seem to match pretty well, so it's worth a try. The recommended cathode bias resistor values seem a bit off though (200-240 ohms recommended for class A operation, LDs have 780 ohms if I recall), but we never used to check that anyway and many tubes still worked regardless...
> 
> This tube could even be a good candidate for a paralleled use (one tube for each channel, strapped cathodes, strapped grids, strapped anodes) since it has medium gm (unlike the 6DJ8's high gm), and because of our amps' cathode bias value (maybe?). Again, bear in mind, half of this is speculation. Then, again, speculation has gotten us this far lol...


 
  
 Paralleled use? Well, first things first! lol
  
 I have ordered an inexpensive pair of CBS 5670 / 2C51 / 396A with black plate and a D-getter....   And if they sound good, will consider getting another breadboard 9-pin socket and trying them paralleled.....


----------



## gibosi

mordy said:


> Thanks Gibosi and AFB, you convinced me not to try it.
> 
> Just out of curiosity, why cannot it be done? Too much current draw?


 
  
 Mordy... I think the answer is that we just don't know what will happen. But it is hard to imagine that it would sound good. And it is easy to imagine that the resulting electrical demands might exceed anything the the LD was designed to handle....


----------



## gibosi

gibosi said:


> The tube on the right is a DARIO / RT / La Radiotechnique E88CC manufactured in the Philips-owned Mazda factory in Suresnes, France. Tube code is F7B1, so manufactured in February, 1967. And it appears that it was silk-screened and packaged in February, 1968 (6802).


 
  
 I have been listening to this tube on and off today during burn in, and Brent Jessee's description is spot on:
  
 "They are sweet like the Holland tubes, with a bit better detail and punch at the top end, and still have nice balanced warmth."
  
 http://www.audiotubes.com/6dj8.htm
  
 If you like the Holland sound these would be a great addition to your collection.


----------



## Audiofanboy

gibosi said:


> Paralleled use? Well, first things first! lol
> 
> I have ordered an inexpensive pair of CBS 5670 / 2C51 / 396A with black plate and a D-getter....   And if they sound good, will consider getting another breadboard 9-pin socket and trying them paralleled.....


 
  
 Apparently, there are or have been adapters made to use 2C51 tubes instead of 6SN7 tubes.
  
 So, since we managed to:
 - Adapt two triodes instead of two pentodes
 - Adapt 12Ax7 (and 6DJ8) double triodes instead of two single triodes
 - Adapt 6Sx7 tubes instead of 12Ax7 tubes
  
 And since it seems one can adapt 2C51 tubes instead of 6Sx7 tubes, at least electrically: one could assume that we could use 2C51 tubes in our amps!
  
 Yeah, I know... The method is a bit weak in this reasoning lol... Real weak.


----------



## TrollDragon

Some octal's with the grid post on top would look great, better yet the dual top posts. I want to see that nice blue plasma glow as well as the filament glow.


----------



## TrollDragon

Roll me some of this...

 Just look at the envy in her eyes...


----------



## hypnos1

Hi guys.
  
 These will be my last musings on the Telefunken ECC88 - I should imagine by now everyone is fed up with my rantings!
  
 After many (happy) hours of revisiting my favourite CDs used for tube comparison, I continue to be blown away. Over the past months, successive tube types have given tangible if often only _gradual_ improvements. And sometimes one can almost give credence to the school of thought that says we rollers are deluding ourselves - tubes being 'merely' vehicles for signal gain (of course we ALL know differently!)...
  
 Anyway, the _immense_ leap I am hearing now TOTALLY blows said school right out of the water...and to a degree that I truly cannot fully understand. The differences are not in just 1 or 2 areas, which is usually the case, but EVERY SINGLE ONE. And as for bass, I never believed headphones could deliver such bone-shaking magic - and my HD650s are not even right there at the top of the heap! All I can think is that these tubes are not just extremely good generally at what they do, but also that they are matching in some really special way the rest of my equipment - the hackneyed saying about the "whole being greater than the sum of the parts?"
  
 Whatever, all I can say is look out for some reasonably priced used tubes - you may need to be patient! - mine cannot be the only set-up that is transformed beyond all expectation...
  
 Good luck...


----------



## Audiofanboy

hypnos1 said:


> Hi guys.
> 
> These will be my last musings on the Telefunken ECC88 - I should imagine by now everyone is fed up with my rantings!
> 
> ...


 
  
 Yup, _this _is what it's all about, basically.
  
 See, I had the _exact_ same troubling impression my first few days with the Amperex Orange Globes tubes, and in turn, again and even _moreso_ with my current Amperex 6922.
  
 It feels like I'm no longer hearing music or sound through my headphones for the first time, in a way. Of course, I've made a bunch of changes throughout the years that gave me this same "feeling", but never that pure and unadulterated. Using a pretty solid pair of orthos on my MK IV SE with the Amp'ex 6922 & a pair of 6N30P-DR, I really do get the sensation I've reached a breaking point. There's just a sense of music being "right" that I never quite managed to get up to now. I'd reached several plateau-like level a few times, but never _that_ good and mesmerizing ! I mean, drums and bass guitar now sound better on my headphones than in the real world (think live concerts and such)... It's actually kind of scary...
  
 Anyway, yes, the Amp'ex tubes were _that_ much of revelation, and these tubes are definitely worth the money, so there is no reason to hesitate.


----------



## hypnos1

audiofanboy said:


> Yup, _this _is what it's all about, basically.
> 
> See, I had the _exact_ same troubling impression my first few days with the Amperex Orange Globes tubes, and in turn, again and even _moreso_ with my current Amperex 6922.
> 
> ...


 
  
 Hi AFB.
  
 Sounds like your Amperexes gel with the rest of your equipment (as with Gibosi's) the same way my TFKs do with mine - I'm quite sure the 6N30P-DRs help a good bit too, especially with the bass! Thank goodness the DRs should have a VERY long life!...And the TFKs, hopefully - swapping the triodes over regularly should see to that, fingers crossed...
 I agree with your 'kind of scary' - I'm still shaking at just the mere thought of what has been transpiring the last couple of days! WONDERFUL...Let's just hope everyone else is able to experience this same magic soon, if they haven't already - as you say "this is what it's all about".


----------



## hypnos1

audiofanboy said:


> Yup, _this _is what it's all about, basically.
> 
> See, I had the _exact_ same troubling impression my first few days with the Amperex Orange Globes tubes, and in turn, again and even _moreso_ with my current Amperex 6922.
> 
> ...


 
  
 As an addendum to my last post, I think I may have finally sussed the extra, magical ingredients that are creating that feeling of being "right" - elements that once again up until now I hadn't fully grasped/comprehended (in my ignorance), although I did have the odd glimpse now and again...ie firstly "attack" - different instruments seem to come in bang on time, with controlled definition and 'purpose', cleanly and without blur/confusion/dominance (hope I'm on the right track here...). And secondly "dynamic range" - I have easily grasped the concept in film soundtrack, where certain special effects are accompanied by massive surges in sound, but have never fully realised and appreciated its more subtle use in plain music, viz its impact when volume, throughout the full frequency range, shifts so smoooothly and effortlessly from soft through loud without coloration, individual element dominance, or distortion.
 On reflection I think these 2 aspects contribute _far_ more  to that "pure and unadulterated" experience you mentioned than is usually covered in reviews - it has taken my current tubes, as with you and yours, to educate me in this...well that's _my_ interpretation, anyway - but who am I?...
  
 Someone who is still on cloud nine!...


----------



## superdux

I have a question considering channel dropout due to tube failure:
  
 as my hifi chain has shown left channel dropouts recently i have swapped cables from the amp to the headphone and the headphone so now i'm at the amp stagewise going backward down the chain.
 Could it be that a faulty tube causes channel dropouts and has anyone of you experienced this before? I'm still not sure and have changed the voskhods for different tubes and am still testing.


----------



## gibosi

superdux said:


> I have a question considering channel dropout due to tube failure:
> 
> as my hifi chain has shown left channel dropouts recently i have swapped cables from the amp to the headphone and the headphone so now i'm at the amp stagewise going backward down the chain.
> Could it be that a faulty tube causes channel dropouts and has anyone of you experienced this before? I'm still not sure and have changed the voskhods for different tubes and am still testing.


 
  
 Have you tried swapping tubes? Moving the right tube to the left socket and the left to the right socket?


----------



## superdux

Yes i should have done that instead of swapping them completely....i didn't switch on my brain


----------



## gibosi

Similar to AFB's 1962 US-Amperex 6922, in my camp, the 1961 holds the throne. However, today I received what I expect to be some major contenders to that throne.
  
 Recently, in the Lyr tube thread, I read a review by rb2013 comparing three 1975 Voskhods and a 1965 US-Amperex 7308.
  
 http://www.head-fi.org/t/673709/schiit-lyr-tube-rollers/750#post_9997718
  
 I already had some 1975 Voskhods on the way and then stumbled on a couple US-made Amperex 7308s, 1965 and 1966, and decided to get them. They were $30 each, way beyond $8, but figured it was highly unlikely I would ever find these for anywhere close to $8....
  
 So anyway, I now have two of the three Voskhods and the 1965 7308 used in that review, so figure I am about ready to have a similar tube "faceoff" between these contenders and my 1961 6922. I have checked to see that these newcomers light up and play, and while I am not sure they need to be burned in, figure it still might be a good idea.....
  
 First the Voskhods: rb2013's tied for second and third place winners
  
 Evidently, there are four different versions of the 1975 Voskhod, based on shield color and getter post. The two I received today have gray shields, but the left one has a wire getter post and the other has a post that appears to be an extension of the shield.
  

  
 And the US-Amperex 7308s: rb2013's tied for second place winner
  
 Even though manufactured almost exactly a year apart (65-42 and 66-40), both have the same change code, and thus I expect them to be virtually identical.


----------



## MIKELAP

Ive been listening for quite a while to the 6BQ7A WESTINGHOUSE tubes that have around 40 hours on them so today decided to put back on a pair of G.E.6DT6A and my first impressions  is that they sounds lean compared to the warm cosy sounding 6BQ7A but after a few minutes you get use to the more detailed neutral sounding 6DT6A that have about 30 hours on them and thats with the Senns HD 800 by the way .


----------



## TrollDragon

I was just wondering what everyone has their "Gain" set to?
  
 When I received the MK IV it came factory at 3, this setting sounded horrible so I moved it to 5, the sound was much better and that is where it has stayed since.
 With all these tube sound impressions, I was just wondering what you all use since the gain setting does affect sound.


----------



## TrollDragon

Hey MIKELAP!

I just popped in the exact same 6DT6A's, these ones seem to have a little hum when unstrapped so I am trying 2-7 right now. Is that how you run yours?


----------



## MIKELAP

trolldragon said:


> Hey MIKELAP!
> 
> I just popped in the exact same 6DT6A's, these ones seem to have a little hum when unstrapped so I am trying 2-7 right now. Is that how you run yours?


 
 No i did not strap them yet. And by the way gain is on ten.


----------



## TrollDragon

mikelap said:


> No i did not strap them yet. And by the way gain is on ten.


 

 Excellent Thanks!


----------



## gibosi

trolldragon said:


> I was just wondering what everyone has their "Gain" set to?
> 
> When I received the MK IV it came factory at 3, this setting sounded horrible so I moved it to 5, the sound was much better and that is where it has stayed since.
> With all these tube sound impressions, I was just wondering what you all use since the gain setting does affect sound.


 
  
 I have heard that it is best to set the gain setting as low as possible, that the lower the resistance in the sound path the better. But I must confess that I do not understand the whys and wherefores....


----------



## TrollDragon

Just running my Tragically Hip select cuts through the 6DT6A's
  
 Blow At High Dough
 Little Bones
 Twist My Arm
 At The Hundredth Meridian
 New Orleans Is Sinking
 38 Years Old
 Boots Or Hearts
 Fully Completely
 Fifty-Mission Cap


----------



## TrollDragon

gibosi said:


> I have heard that it is best to set the gain setting as low as possible, that the lower the resistance in the sound path the better. But I must confess that I do not understand the whys and wherefores....


 

 I don't either but the lowest gain on my amp didn't sound very good.


----------



## gibosi

trolldragon said:


> I don't either but the lowest gain on my amp didn't sound very good.


 
  
 I have also heard that setting the volume control between 10 and 2 is optimal. If so, then perhaps setting the gain such that your preferred listening level is achieved with the volume between 10 and 2 makes some sense? (Again, I am just stabbing in the dark, as usual! lol


----------



## TrollDragon

gibosi said:


> I have also heard that setting the volume control between 10 and 2 is optimal. If so, then perhaps setting the gain such that your preferred listening level is achieved with the volume between 10 and 2 makes some sense? (Again, I am just stabbing in the dark, as usual! lol


 

 Yes I have my volume at 11 right now with a gain of 5. It seems to work nicely keeping the volume control close to middle so there is plenty of play either way.


----------



## mordy

Left the gain on the factory setting - don't remember what it is. As for volume on the MKIII, I turn it up until I hear distortion, and then back off a little. My volume control has a scale etched on the face plate, and I usually set it to around 80, which would correspond to around 3 o'clock. This is for listening through speakers.
  
 Using headphones this is way too loud, and my regular setting is around 20 on the face plate corresponding to 9 o'clock.
  
 When using speakers I found the bass to get better at close to clipping on the LD. Using the above setting for speakers the volume is controlled by my receiver which is set quite low since the LD amplifies the signal to play louder than using the receiver alone.
  
 Having the receiver volume fairly low I cannot hear hum, but when I turn up the receiver volume to very loud there is a faint hum. This us usually drowned out by the music, but if I don't play anything and turn the volume very high I hear hum.


----------



## Artsi

trolldragon said:


> I was just wondering what everyone has their "Gain" set to?
> 
> When I received the MK IV it came factory at 3, this setting sounded horrible so I moved it to 5, the sound was much better and that is where it has stayed since.
> With all these tube sound impressions, I was just wondering what you all use since the gain setting does affect sound.




I played a lot with different gain settings when i got my amp. Gain 4x was the best for me every time.

Diy tube headphone amp project have been eating my sparetime really badly. Hope to get 6A6 tubes in good use with first prototype. They were not so good for little dot.

I got my first 4 pairs of real 6SN7 tubes yesterday. One was dud,but thankfully it was the least interesting pair. Hope i could say something about sound affects of these tubes one day. Since no one else is not using these as powertubes yet,there is no hurry to give any ratings for these.

Bought Philips SHP895 headphones for 10 euros and have been using them. Sound is much calmer and smoother with these than superluxes. I could even listen some heavier music. It takes time to get used to new sound.


----------



## TrollDragon

Thanks mordy and Artsi!

mordy you should try a different gain setting 4 or 5, you might be pleased with the results.

Artsi are you building a DIY amp? If so check into the "I (Heart) Tube Amps" group on Facebook, those guys there really know their stuff.


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## mordy

Here is a link to MKIII/IV gain settings from the Little Dot forum:
  
 http://www.littledot.net/forum/viewtopic.php?t=422
  
 Seems that Texas Instruments agrees with my approach of high volume from the LD into the power amp and power amp on very low. (If I understand this correctly)
  
  
 "Gain Setting for the Audio Power Amplifier
 It is also imperative to understand that the output signal from the CODEC or DAC driving the
 audio power amplifier should be as large as possible, to have a high SNR. Conversely, the gain
 of the audio power amplifier is set as low as possible. If the audio power amplifier’s gain is set
 too high, then it amplifies the noise floor, along with the actual wanted signal of the CODEC or
 DAC. This decreases the dynamic range of the signal and reduces the quality of the sound."
  
  
*Posts:* 4
*Joined:* Feb 22nd, '09, 06:18


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## hypnos1

On a slightly different tack, but after all we _are_ all trying to squeeze the last ounce of performance by tube rolling are we not? And sometimes paying quite dearly for it, lol!
  
 Something I had been mulling over for quite a while - brought to a head by a VERY annoying tendency for a channel to disappear when waggling the headphone cable! - and that was to see if I could get similar improvements to when I replaced the internal wiring of my Dynaudio speakers, and did away with the binding posts, soldering direct to the board. What a massive difference that made - using pure silver wire, mind you...Anyway, as I had to undo the Neutrik socket to see what was going on, my mind was made up there and then - so-called "upgraded socket" on the MKIV SE? - If this is the best Neutrik can do, I would advise EVERYONE to get rid ASAP!! Actually, when you think about it, it is rather silly to go spending a lot of money on upgrading cables/plugs/mains filters etc. etc. for the lovely new signal to get trashed by the headphone jack/socket combo.
 So it is I duly removed said culprits (actually, the cable fitted nice and snugly through the hole in the socket) and soldered the silver darling direct to the board...gone is the aforementioned occasional loss of channel, and even before the new solder has settled in I am seeing positive results viz - the Tesla E88CCs (with gold pins and grids) that have just recently gone in, and which were sounding rather lacking in the bass department compared to the Telefunkens (mind you, it _is_ early days of course...) are all of a sudden almost matching the TFKs!! So this is boding VERY well indeed - can't wait to get the latter back in and see what transpires...my lips are smacking already...
  
 The upshot is, of course, if you have just _basic_ soldering skills you might want to give this tweak a try...the front panel on the MKIV SE comes off easily enough (don't know about other models) and there's plenty of room to work on the solder points. (The volume knob does have a VERY tiny allen inside, but in the end mine was dud and the knob was actually being held on the spindle by a piece of insulating tape!!...Mmmm...)
  
 I am a firm believer in having as few 'connectors' in the signal path as is possible - as you may have gathered...
  
 Cheers!


----------



## gibosi

I received a pair of CBS 5670 / 2C51 / 396A today. Black plates, D-getter. Squat little guys that remind one of a 9-pin 6AK5....
  

  
 But first... While burning in the 1965 US-Amperex 7308 and the 1975 Voskhod 6N23P with the getter attached to a gray shield, I have been able to listen to them only casually. Even so, my impression is these are among the very best of the best, and I recommend them without reservation.
  
 However, have put them aside in order to fire up the CBS 5670. With the breadboard 9-pin socket, even though I had to reconfigure all the connections but one, it was a relatively easy task. As with the 6DJ8, I found it necessary to connect the shield (pin 5) to cathode #2 (pin 8).
  
 Like so:
  
 9-pin socket        Left Vector     Right Vector
  
 1 heater                                      4
 2 cathode #1             2
 3 grid #1                   1
 4 plate #1                 5
 5 shield to pin 8                           
 6 plate #2                                   5
 7 grid #2                                     1
 8 cathode #2                               2
 9 heater                                      3
  
 So.... They light and play.... No distortion or weird noises..... In fact seem very musical....  But way too soon to say how good they are relative to the 6DJ8....
  
 Anyone else feeling adventurous enough to follow me? lol


----------



## MIKELAP

Finally got my sockets today after a 5 week wait ,so starting to assemble the 6v and 12v adaptors as for the octal adaptor thats on the way another 3 weeks possibly that adaptor is plug and play.   As you can see its simple but made to last.


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## Audiofanboy

gibosi said:


> I received a pair of CBS 5670 / 2C51 / 396A today. Black plates, D-getter. Squat little guys that remind one of a 9-pin 6AK5....
> 
> But first... While burning in the 1965 US-Amperex 7308 and the 1975 Voskhod 6N23P with the getter attached to a gray shield, I have been able to listen to them only casually. Even so, my impression is these are among the very best of the best, and I recommend them without reservation.
> 
> ...


 
  
 Nice! So the 2C51 type not only lights up and plays music (which we all kind of expected at this point) but also sound at least "OK" for now. Well, I guess that just gives a whole new field to investigate then!
  
 Will follow on the 2C51 type at some point; right now I'm too busy to even follow up on my _own_ ideas (yeah, that a conundrum for you lol), just like for octals, which I have to even test (though someone else had the same idea a week ahead of me!)... Also, the high prices of the 6922/E88CC & 7308/E188CC tubes I keep looking at are making me instinctively try to _save _money, or to at least rationalize my spending (they're definitely worth it though, as you, me, and a few more lads keep mentioning).
  
 Again, anyone have a Western Electric 396A in his stash? So, we can just figure whether or not it's worth pursuing the 2C51 type (preferably before much collective cash has been invested)?
  
 On a lighter and more general note, I use my MK IV SE on gain 10, because it both sounds the best to my ears (whether with my previous HD650 or current HE-500) and because it gives me the most "power" (read volume, but it's actually the least amount of feedback, as in "the least amount of reduced volume due to global negative feedback").
  
 I've always found the gain x3 setting, while not unpleasant, to sound quite garish, with boomy loud bass and a overly tubey-warm sound. Gain x4 and x5 improved that quite a bit (I recall actually using gain x 5 with Senns for a few weeks, way back when, without feeling it was horrible), but ultimately, gain x10 gives me the most detailand hi-fi-ish sound, and, as some have said, let's the traits of all the tubes shine though. So, if you have bad tubes and cheap headphones, use any gain setting but the x3; if you have good or excellent tubes and high Z or low sensitivity headphones, use gain x10 (_imho_, of course). If you use the amp as a preamp, I haven't actually managed to figure out what sounds the best, despite trying. Then again, I hardly ever use my LD as a preamp anymore (I use to quite a bit, now only sporadically).


----------



## gibosi

audiofanboy said:


> Nice! So the 2C51 type not only lights up and plays music (which we all kind of expected at this point) but also sound at least "OK" for now. Well, I guess that just gives a whole new field to investigate then!
> 
> Again, anyone have a Western Electric 396A in his stash? So, we can just figure whether or not it's worth pursuing the 2C51 type (preferably before much collective cash has been invested)?


 
  
 I am pretty impressed with the CBS 5670. Unfortunately, I am not familiar enough with this family of tubes to know if CBS actually made them, or if these are simply rebrands. They resemble some GE and Sylvania I have seen, but not exactly. Anyway, they sound good, with a balanced tonality and good detail and clarity. But as I have been listening to 6922 and 7308 lately, I don't think these CBS tubes are at that level. So for sure, I would like to try the best of the breed. And yes, if someone has a Western Electric or a Bendix  2C51 / 396A / 5670 they would willing to send me, that would be great! lol 
  
 Also, as the 9-pin socket has to be entirely rewired to switch between 6DJ8 and 2C51, it is not at all easy to compare them. However, there is an adapter which would make this nice and easy. The socket can be left in the 6DJ8 configuration and 2C51 could be used with this adapter.
  
 http://www.ebay.com/itm/260723522614?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649


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## Artsi

trolldragon said:


> Artsi are you building a DIY amp? If so check into the "I (Heart) Tube Amps" group on Facebook, those guys there really know their stuff.


 
 After trying couple different schematics with my DIY 6SL7 6A6 amp i have come to conclusion that *Little Dot MK II is very compact, powerful, clean sounding and hum-free device*. It is hard to beat with any homemade contraption.
  
 Most problematic with my DIY headphone amp seems to be variable humming when turning volume. 
 Soldering continues...


----------



## Audiofanboy

gibosi said:


> I am pretty impressed with the CBS 5670. Unfortunately, I am not familiar enough with this family of tubes to know if CBS actually made them, or if these are simply rebrands. They resemble some GE and Sylvania I have seen, but not exactly. Anyway, they sound good, with a balanced tonality and good detail and clarity. But as I have been listening to 6922 and 7308 lately, I don't think these CBS tubes are at that level. So for sure, I would like to try the best of the breed. And yes, if someone has a Western Electric or a Bendix  2C51 / 396A / 5670 they would willing to send me, that would be great! lol
> 
> Also, as the 9-pin socket has to be entirely rewired to switch between 6DJ8 and 2C51, it is not at all easy to compare them. However, there is an adapter which would make this nice and easy. The socket can be left in the 6DJ8 configuration and 2C51 could be used with this adapter.
> 
> http://www.ebay.com/itm/260723522614?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649


 
  
 Well, we _could _go raid other 2C51-using gear threads, and mine information (or beg for 396A) there, like we've been doing with the Lyr thread (despite not owning the Schiit) lol...
  
 Anyone got a foothold in the MDHT Havana thread lol?


----------



## TrollDragon

artsi said:


> After trying couple different schematics with my DIY 6SL7 6A6 amp i have come to conclusion that *Little Dot MK II is very compact, powerful, clean sounding and hum-free device*. It is hard to beat with any homemade contraption.
> 
> Most problematic with my DIY headphone amp seems to be variable humming when turning volume.
> Soldering continues...


The routing of wires seems to have a lot to do with hum, the faint hum in my MKIV these days I am pretty sure is coming from the heater wires and where they lay on the board as it was dead quiet when it first arrived. I am going to have to pop the back off and move the heater wires around with a chop stick to see if I can make it disapear. Failing that foolishness I'll see about a pair of 3A regulators and a couple of bridges to switch the heaters over to DC. There would be no hum once its 6V DC. 

On the FB group where they build the amps, all the wiring is point to point and very short, heater wires are specifically routed away from other lines etc... I don't think you could just fly wire up the amp outside of a metal enclosure and have it not hum, but carry on with your experimentation and post some info if you make any progress!


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## hypnos1

Well folks, all I can say is getting rid of the headphone jack and socket is definitely worth the (minimal) effort. It is doing wonders for the Teslas - should have done it sooner.
 Be bold, give it a go! And after peeking inside and seeing the piffling bits of cable emerging from the inputs, hopefully I shall be able to get at them also at a later date! (But suspect that won't be _quite_ so easy...).


----------



## vic2vic

hypnos1 said:


> Well folks, all I can say is getting rid of the headphone jack and socket is definitely worth the (minimal) effort. It is doing wonders for the Teslas - should have done it sooner.
> Be bold, give it a go! And after peeking inside and seeing the piffling bits of cable emerging from the inputs, hopefully I shall be able to get at them also at a later date! (But suspect that won't be _quite_ so easy...).


 
  
 I'm quite interested on this mod (I own an LD MK II). Any suggestion for a replacement jack ? I was thinking about the Neutrik one, but that's actually the one you removed


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## Nic Rhodes

If you like 5670 / 2C51s try the LM Ericsson golds.


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## gibosi

nic rhodes said:


> If you like 5670 / 2C51s try the LM Ericsson golds.


 
  
 Sure! Do you have a source? I haven't seen any on eBay.....


----------



## Ctritical Bill

Received my little adapter board for using octals :
  

  
 ....and these are the tubes I have to work with :
  

  
 The first is unknown as most of the printing has worn off but, from what remains, I think it is a Westinghouse. Next we have a NOS Russian and then the Sylvania.
  
 The interesting thing about these boards is that it allows you to take measurements which is something I have been wanting to do for a while. Here are my results :
  
                            Heater         Plate         Cathode
  
 Westinghouse  (L) 6.38v           147.8v         1.052v
                      (R)                   147.1v         1.067v
 Russian NOS    (L) 6.36v           151.7v         0.991v
                      (R)                   153.7v         0.950v
 Sylvania          (L)  6.38v          150.6v         1.028v
                      (R)                   152.7v         0.982v
  
 Things to note :
 The heater voltages are very close to 6.3v . I live in 240volt land where I measure 238v at the wall and the Little Dots are designed for 220v so if the heater power supply were unregulated I would expect a much higher measured heater voltage. Several pages back someone showed a photo of the transformer and the driver tube heater windings were 6.6v @ 1 amp so looks like some sort of regulation is taking place. A good thing.
 The grid voltage is down around 1v . This seems rather low and you might expect to hear distortion at higher volumes. Not surprising as the Little Dot is not designed for the 6SL7.
  
 The wonderful thing about this adapter board I got is that you can easily add resistors in line to each pin so that is what I did. I had some 240 ohm resistors to hand so I soldered them in the cathode circuit and, together with the LD cathode resistor of 680 ohms, I got 920 ohms in total.
 This is how it affected the results :
  
                            Heater         Plate         Cathode
  
 Russian NOS (L)   6.36v           158.8v         1.189v
                  (R)                      160.6v         1.141v
 Sylvania      (L)    6.38v           156.4v         1.233v
                  (R)                      158.0v         1.184v
  
 Adding the extra resistor has increased the grid voltage by about 0.2v which should increase headroom and the plate voltage has gone up by about 6v as the current will have gone down a little. Not sure if the plate voltage is a problem as I haven't been able to measure the B+ yet but it does seem a bit high. Also you can see a difference in the right and left channels due to imbalance of the two triodes in the tube. If you used a trimpot instead of a resistor you could tune out that imbalance and optimise the grid voltage. Maybe next time ......
  
 Be interesting to know if anyone else has taken measurements with different tube families.


----------



## Nic Rhodes

gibosi said:


> Sure! Do you have a source? I haven't seen any on eBay.....


 

 I use my private stash but some appeared on ebay in the last month (several lots) so stick with it but they do go for significantly more money than the rest of this designation. Sylvania gold brand are VERY good also (and RCA Command / GE 5*) but even when you get to the likes of Raytheon etc then the tube is still of excellent quality. The UK / US tubes in this designation are consistently high quality, more so than most tubes.


----------



## Audiofanboy

ctritical bill said:


> The interesting thing about these boards is that it allows you to take measurements which is something I have been wanting to do for a while. Here are my results :
> 
> [...]
> 
> *Be interesting to know if anyone else has taken measurements with different tube families.*


 
  
 Indeed. While it's all fine and dandy that we managed to get all those _definitely non-native_ tube types working on our LDs, it would be good and safe to actually measure whether or not everything is working properly.
  
 One could imagine a premium double triode working fine and sounding great on an amp that wasn't made for it, but having a catastrophic failure after a few weeks because the electrical values were outside of the acceptable range; happens pretty often actually, even within the same tube family on one amp. An example I've read about - on Joe's tube lore and elsewhere - is that Audible Illusions preamps can use new production Sovtek-ish 6H23N & 6N1P tubes, but not NOS 6DJ8 types because it runs the tubes so hard that the NOS tubes fail quickly.
  
 The problems we could encounter with 6DJ8 or 6SL7 tubes on our LDs aren't exactly the same, but I could totally imagine how it could be bad to run a basic 6DJ8 (intended for a meager 90V of plate voltage - correct me if my vocabulary is off) at a 130V+ plate voltage, while a 6922 or 7308 would tolerate those voltages without blinking. It all boils down to how large our electrical "margins" are.
  
 So, yeah, any real world measurements on 6DJ8 types would be reassuring lol...
  
 ------------------------
  
 Speaking of novals, after raiding ebay for about a week, and camping a few different auctions for days, I finally managed to get my hands on a nice pair of tubes I'd been looking for.
  
 A pair of NOS NIB - that fact is rare in and of itself - Philips "Holland" E188CC, with factory codes VR2 and delta PO, so not the most common tubes - a fact that cost me a three-digit number _in euros_... But it's all fun and games I guess... Bear in mind these are the exact same tubes as the Amperex Holland E188CC/7308, the Valvo E188CC, Miniwatt E188CC, RTC E188CC, RT E188CC & Dario E188CC _so long as they were made in Heerlen, Holland_.
  
 What is interesting is the factory codes here. The delta code and other writings confirm a Heerlen origin, so I'm not worried about that. But the lack of a proper year code (a "P" instead of number) kind of threw me off at first (I almost didn't bid because of that). Fortunately, I had the whole 6 days left on the auction to check out essentially _everything_ I could about the E188CC type and production over the years lol.
  
 While I couldn't make anything of the bottom codes (delta PO) to determine a production year, the top factory codes turned out to have all the necessary information, thanks to the _change code_ - which I've hardly ever had to analyze up to now.
  
 "VR" means E188CC/7308, no doubt here; but change code "2" meant that the tube was part of the third "batch" of this tube type ever produced (or of a third batch after they ran out of numbers, and started over, which seems unlikely). I could tell the tubes were from the 60's for a few reasons (labels and other cues) but I just didn't know _when_ in the 60's; and I was looking for the earliest tubes I could find - or afford lol...
  
 Turns out that after looking at a gazillion other E188CC tubes on google and ebay, code VR2 means that these were part of a batch made in 1960, since any tube made later has a higher change code (actually, almost all the Heerlen-made E188CC you find have VR6 to VR9 codes and were made in the mid to late 60's, so much later). But what's even better is that tubes with the VR0 (first batch ever) or VR1 are the famous very early late 50's production with either a D-getter or a folded D-getter (= extreme prices); almost prototype-like tubes in a sense. So the VR2 tubes should essentially be the first batch of large O-getter E188CC tubes to have come out of Heerlen (give or take a few months). And as gibosi and I realized with the US Amperex 6922, _the earlier the better_, and those VR2 are pretty early!
  
 Anyway, hopefully they'll turn out to be great tubes, and I may have to settle for those production dates, since earlier tubes are both rare and expensive. Sorry for the long useless spiel about factory codes, but I figure exposing my thought process and findings on these matters could be of _some_ use for a few people seeking the best 6922/E88CC & 7308/E188CC for reasonable prices. Do tell me if my rantings are getting annoying or purposeless lol!


----------



## gibosi

audiofanboy said:


> Turns out that after looking at a gazillion other E188CC tubes on google and ebay, code VR2 means that these were part of a batch made in 1960, since any tube made later has a higher change code (actually, almost all the Heerlen-made E188CC you find have VR6 to VR9 codes and were made in the mid to late 60's, so much later). But what's even better is that tubes with the VR0 (first batch ever) or VR1 are the famous very early late 50's production with either a D-getter or a folded D-getter (= extreme prices); almost prototype-like tubes in a sense. So the VR2 tubes should essentially be the first batch of large O-getter E188CC tubes to have come out of Heerlen (give or take a few months). And as gibosi and I realized with the US Amperex 6922, _the earlier the better_, and those VR2 are pretty early!


 
  
 This is good information to have. I have a single Heerlen-made Dario VR2 coming to me from France. (It is taking longer to get a tube from France than from the Ukraine! It was shipped on November 11! lol). Tube code: VR2 40H3. (And of course, since the Heerlen delta character is not readily available on most computer keyboards, many vendors use the number 4). I knew from the change code of 2 that it was early, that is, August, 1960, rather than 1970, and I would guess that your "PO" tubes are even earlier. I am hoping to have it next week and really looking forward to seeing how this tube compares to the US-made Amperex.


----------



## Audiofanboy

gibosi said:


> This is good information to have. I have a single Heerlen-made Dario VR2 coming to me from France. (It is taking longer to get a tube from France than from the Ukraine! It was shipped on November 11! lol). Tube code: VR2 40H3. (And of course, since the Heerlen delta character is not readily available on most computer keyboards, many vendors use the number 4). I knew from the change code of 2 that it was early, that is, August, 1960, rather than 1970, and I would guess that your "PO" tubes are even earlier. I am hoping to have it next week and really looking forward to seeing how this tube compares to the US-made Amperex.


 
  
 Good timing lol! So, someone agrees with my reasoning at least; always reassuring.
  
 Yeah, what's odd about the date codes on my pair is that weird "PO" (or probably "P0", looking at the pictures again, which is even weirder since the third character should be a letter between A & L for the month) after the delta symbol. It really almost sounds a prototype code or somekind of "special" date code.
  
 At any rate, 1960, and probably mid-year, since I've seen _VR3_ tubes with delta 0 codes, and _VR1_ tubes also with delta 0 codes, meaning that the VR2 code was short lived and sandwhiched between two other codes in 1960.
  
 Quote from random lad on google: "_The first line VR1 code signifies the first revision of the E188CC tube after the original best ever sounding VR0 version. The VR0 version appeared in December 1959 to January 1960, with the VR1 revision coming into existence thereafter in February 1960._"
  
 VR0 definitely has a D getter. All the VR1 I've seen have a D-getter (possibly folded D), and I assume that there were no changes in production without making a different batch. So, VR2 should be the first O-getter batch. I've seen VR1 with delta 0C codes, so at least from March 1960 onwards. And I found an auction with two VR2 and two VR3 tubes, coded either VR2 delta 0J2 or VR3 delta 0J3, so change between VR2 & VR3 batches should have been during mid-october 1960. So, yeah, a VR2 E188CC made in Heerlen should be dated sometime in the middle of year 1960. Fweew! Glad that's settled.
  
 Hopefully, I should get my tubes fairly quickly, since they're in France in the first place (though it often takes as long to get tubes within the country as shipped from Canada, either due to the seller's laziness or due to _unpredictable _patterns in the French postal service; usually just seller laziness syndrome though...). If your tubes are taking 3 weeks to get to the US from France, I would start to, perhaps not worry, but at least inquire as to their whereabouts. 10 business days should be more than enough between two developed nations... In theory...
  
 Edit: Color me surprised, there are more mystery (actually clearly identified) VR2 delta P0 E188CC out there. And pretty close too lol, since it's here on head-fi! Not that the people there had any better ideas to make sense of the the "P0" code...
  
http://www.head-fi.org/t/633006/aune-t1-usb-tube-dac-amp-discussion-thread-see-first-post-for-faq/2850


----------



## TrollDragon

ctritical bill said:


> The heater voltages are very close to 6.3v . I live in 240volt land where I measure 238v at the wall and the Little Dots are designed for 220v so if the heater power supply were unregulated I would expect a much higher measured heater voltage. Several pages back someone showed a photo of the transformer and the driver tube heater windings were 6.6v @ 1 amp so looks like some sort of regulation is taking place. A good thing.


 
 Nice work Ctritical Bill.
  
 There is NO regulation on the filament windings, all 4 pairs of 6.3V wires go straight to the transformer. The primaries are listed as 120+120 so in series it would be 240V and that would fit fine with your 238V.
  
 If you've missed it earlier and can possibly be of any use. Here is the "*Very Rough*" schematic I made of the LD MKIV and it's power supply section, only the left channel is shown as it was the easiest to follow the traces for and the right channel would be an exact mirror image.

(Don't forget to click on "*Original*" and click the picture again to get the maximum size before you right click save)


----------



## mordy

Hi Ctritical Bill,
  
 I just got the same breadboard as you. I am new to soldering. How do you best solder in the leads where the resistors are supposed to be?
  
 What kind of feet are you using? Golf tees?  I found little pieces of self stick foam that I cut to size and put underneath. Also, in order for better heat dissipation by the tube on the breadboard, I moved my LD back on the shelf and placed the adapter in front of the amp on little pieces of wood and foam.


----------



## hypnos1

vic2vic said:


> I'm quite interested on this mod (I own an LD MK II). Any suggestion for a replacement jack ? I was thinking about the Neutrik one, but that's actually the one you removed


 

 Hi vic2vic.
  
 From what I can see in the pics of the MKII your socket is different to mine on the IV SE, so I'm afraid I don't think I can be of much help to you if you intend to keep with the plug/socket combo...my mod was to remove the plug anyway and solder the cable direct to the board inside the amp.(which I can understand might not appeal to everyone, as of course that is then a semi-permanent arrangement if further changes are on the cards re headphones...although not TOO much of a hassle to re-do if necessary!).
  
 One point I must make, however - doing away with the 'choking' effect of the plug & socket, plus inferior cable from the board has had an unforeseen consequence...the increased frequency range is showing up any over-exuberance by the recording engineer in the treble department! Something my pure silver cables are especially prone to do sometimes. But then again, I would much rather have the FULL sonic experience, warts and all, than something that 'tames' certain aspects of the studio's preferences/poor equipment!


----------



## Ctritical Bill

mordy said:


> Hi Ctritical Bill,
> 
> I just got the same breadboard as you. I am new to soldering. How do you best solder in the leads where the resistors are supposed to be?
> 
> What kind of feet are you using? Golf tees?  I found little pieces of self stick foam that I cut to size and put underneath. Also, in order for better heat dissipation by the tube on the breadboard, I moved my LD back on the shelf and placed the adapter in front of the amp on little pieces of wood and foam.


 
  
 Yes, I am pleased I got these boards as they are very versatile, you can use 9 and 7 pin sockets with them too. Also they look much better than my previous attempts.
 I just cut some short pieces of wire and soldered them across just one of the links. The links are joined in pairs so only necessary to put in one link.
 The feet are computer motherboard standoffs that I had lying around, just the right size.
 I thought about putting the board at the front but the headphone cable is in the way on the MK111 but raising it up would get over that problem. I think it would look neater that way.


----------



## mordy

Hi All,
  
 Here is a report of my first octal tube, a National Union 6SL7GT probably from the 1950's. Since my 6AK5 days I always thought that National Union was a sister brand to Tung Sol since they were both manufactured in the same area in New Jersey. (Newark, Orange)
  
 So I thought that I snagged a bargain Tung Sol that just squeezed in at my $8 limit including shipping. A little research seems to indicate that they were two different factories and I could not find any information that Tung Sol acquired National Union (not to be confused with National which was the earlier name for the Japanese Matsushiita).
  
 Here is a picture of the prototype octal flying adapter. The main reason I placed the tube in front of the amp was for heat dissipation and that the socket with  6SL7 to 12AX7 adapter + tube was too tall to fit on the shelf on top of the LD amp. I will try to get a more "professional" set up with the new breadboard on the right.

  
 Now about the tube:

  

  

  

  

  
 The only identification letters on the the tube are YT on the blackened glass, and KC on the base. KC  = December 1953? Would appreciate if anybody has information, as well as information if there is a link between NU and TS.
  
 The tube was sold as used and tested "good", whatever that means. The sound has improved over the 50 hours that I am running it which makes me believe that perhaps this tube is new.
  
 The first impression listening is that that it requires higher gain than the 12AX7/6DJ8 families. Second impression is that the bass and treble are very nicely extended, similar to the Voskhod 6Sh1P-EV, but much nicer and sweeter than the Voskhod. Third, this tube runs very cool and never gets hot to the touch.
  
 After extended burn in my impression is a very sweet tube with no harshness at all in the treble, especially listening to strings. Cymbals are technicolor shimmering, and the low bass is fat and authoritative. The mid range is very sweet and voices are very natural.
  
 On the con side there is a lack of quickness, attack and slam in the mid bass and not the greatest etched detail, especially compared to the Amperex A-frame 6DJ8. However, it makes it up in the overall sweetness and overall pleasant, beautiful and non fatiguing sound. A keeper.
  
 Don't know why the octals are more expensive than most of the other tubes we have tried. Perhaps people think that bigger is better, and these tubes certainly are much bigger the 7 and 9 pin tubes suitable for the LD MKIII. Too, it could be that they are more rare, being older and production ceasing earlier than the other smaller tubes.
  
 Would appreciate help in a possible TS-NU link, and the dating of this tube.
  
 Happy tube rolling!


----------



## Ctritical Bill

Hi TrollDragon
  
 Thankyou for posting the schematic, makes it easier to see what is going on. I would really like to get voltages with stock 6AK5 tubes so that we have a reference for the ideal settings.
 I am still surprised at my heater readings as the 6SL7 only draws 300ma and the transformer is 6.6v @ 1 amp but I am happy with that as the heaters aren't being over-volted.
 Have you been able to measure the B+ ? I guess it must be a bit over 200v but if we knew for sure everything else could be calculated.
  
 I have been thinking more about these 6SL7 tubes and although they sound very good in the LD (especially the soundstage) I think they are very unsuited. In this sort of design with a push-pull output stage, the plate voltage on the driver tube should be half the B+ to balance the drive to the output tubes. The 150-160v I am measuring is way out so one triode of the output tube is going to be overdriven. Also the grid voltage at about 1v is too small to prevent clipping and will lead to distortion which I think I am hearing in the treble.
 The datasheet I have of the Brimar 6SL7GT quotes the operating characteristics as plate voltage 250v and grid voltage 2v so you can see how far out from ideal we are.


----------



## gibosi

ctritical bill said:


> Thankyou for posting the schematic, makes it easier to see what is going on. I would really like to get voltages with stock 6AK5 tubes so that we have a reference for the ideal settings.
> I am still surprised at my heater readings as the 6SL7 only draws 300ma and the transformer is 6.6v @ 1 amp but I am happy with that as the heaters aren't being over-volted.
> Have you been able to measure the B+ ? I guess it must be a bit over 200v but if we knew for sure everything else could be calculated.
> 
> ...


 
  
 And in addition to the 6AK5, I think it would be useful to have similar measurements for the EF91 and EF92, as these are very different than the EF95. Given the enormous variety of tubes that I have successfully used in my LD over the past year, my impression is that the LD was designed to easily accommodate a very wide range of tubes.
  
 Re: Octals.... I have a Tung-Sol 6SU7GTY and a Sylvania "Chrome Top" 6SL7WGT, in other words, two of the best, and I have not heard any high frequency distortion with my ears (admittedly old) and gear......


----------



## TrollDragon

You are most welcome Ctritical Bill. I didn't measure it but I will pop the back of my amp later and see if I can get a reading for you. The board is a real pain to remove from the case on the MK IV, so I should be able to reach a test point with a wire on a probe.


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## Ctritical Bill

Actually, thinking more about this, I can calculate the B+ from my measurements and the value of the plate resistor from your schematic. And the number is ....... 200v almost exactly.
 So the plate voltage on the driver tube really needs to be down around 100v which is close to ideal for the 6DJ8 as it happens.


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## mordy

Can a 6SC7 tube be substituted for a 6SL7 tube? What is the difference/advantage of a metal tube vs a glass tube?


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## MIKELAP

Could any of these steel and glass octals be used with the Littledot i have and old tube radio and i use these tubes 6AC7, 6SQ7, 6SK7 6F6G ,6SA7,. Finally having a listen on new 6v. adaptor to my Holland made 6DJ8 Bugle Boys really nice detailed very clean sounding great separation between instruments and wide soundstage nice. Cant wait to try octals see how those sound.


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## TrollDragon

mikelap said:


>


Nice Job!
Except for the blue of course there is not quite enough shine for me... Just Kidding. 

Now if you put two of those 3/4 to 1/2 tees end to end, you could put a 6DJ8 socket on one end and a socket for a 12AX7 on the other end ... One tube used at a time of course. Parallel wires from one B9A to the other with the appropriate changes at the socket end...


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## TrollDragon

My ceramic sockets are on the last Rickshaw out of Chi-Nee town, swinging by the USSR to grab the tubes on the way I think.


----------



## MIKELAP

trolldragon said:


> Nice Job!
> Except for the blue of course there is not quite enough shine for me... Just Kidding.
> 
> 
> ...


 
 Why do you put crazy ideas like that in my head ,would look great Hmmm. Damm you got me thinking about it 
	

	
	
		
		

		
		
	


	




.


----------



## Ctritical Bill

I added a 36K ohm resistor on the plate of the 6SL7 to try and get the voltage down. Here are the results :
  
  
                                      Plate         Cathode
 Stock setup - no additional resistors :
  
 Sylvania          (L)          150.6v         1.028v
                       (R)          152.7v         0.982v
  
 Added 240 ohm cathode resistor for 920 ohms total:
  
 Sylvania      (L)             156.4v         1.233v
                   (R)             158.0v         1.184v
  
 As above plus 36K ohm plate resistor for 69k total:
  
 Sylvania      (L)             127.3v         1.024v
                   (R)             129.4v         0.994v
  
 So the additional resistor on the anode has brought down the plate voltage but the cathode voltage has gone down again too. This is to be expected as there is now less current through the tube and therein lies the problem.
 At stock setting there is about 1.5ma across the tube which is low to begin with and with the additional resistors it is now down to about 1.1ma . According to the datasheet, at 100v and 1v grid it would be down to 0.75ma . I don't think it is worth taking this further as it is fast approaching cutoff.
  
 A better candidate in this circuit would be the 6SN7. Has anyone tried this as a driver ?


----------



## gibosi

mordy said:


> Hi Ctritical Bill,
> 
> I just got the same breadboard as you.....


 
  
 Would you and/or Ctritical Bill post a link to one of these breadboard sockets that allow one to add resisters? The 6DJ8 family, including the 6922 and 7308, could well be my end-game tubes. And while these tubes sound incredibly good now, it does make sense that if we can optimize the electrical values, or at least get closer to optimum, these tubes may actually sound better. Thanks!


----------



## Ctritical Bill

Here you go :
  
 http://www.ebay.com.au/itm/1SET-8pin-K8A-tube-test-diy-Experiment-prototyping-pcb-for-6V6-EL34-KT88-6SN7-EM-/190889423497?pt=R%C3%B6hren&hash=item2c71e57289
  
 The seller has the same board with different sockets or just the board on it's own.


----------



## Audiofanboy

gibosi said:


> Would you and/or Ctritical Bill post a link to one of these breadboard sockets that allow one to add resisters? The 6DJ8 family, including the 6922 and 7308, could well be my end-game tubes. And while these tubes sound incredibly good now, it does make sense that if we can optimize the electrical values, or at least get closer to optimum, these tubes may actually sound better. Thanks!


 
  
 It would be great if we could determine "optimized" values for all the resistors used for different tube types, whether noval or octal. But, looking at the 6DJ8 datasheets again - and listening to those tubes on my MK IV - I keep thinking that it's almost like the amp was _made_ to use those tubes...
  
 The cathode resistor values should definitely be pretty close to recommended specs for 6DJ8 types. At least moreso than for any of the 12Ax7 types. From memory, I think the values also fit a 6SN7 pretty well too, though they didn't seem totally out of spec for 6SL7 tubes.
  
 Again, 6922/E88CC & 7308/E188CC types may actually be some of the best "fits" we can find for our LD amps, just because of their tolerance for higher plate voltages. The 6922 has both the best sound quality I've ever gotten out of the amp, and also the best "running conditions" I've ever managed to get, with low, low temperatures and low current draw.
  
 Getting real world values for those tubes really would be great, if only just to know whether or not it's worth to actually invest in the best tubes, and potentially just "mod" the amp itself to use those tubes.
  
 By "mod", I'm thinking more of socket modding: either cutting the PCB trace connecting pins 5 and 6 so two separate tubes can be used on each socket with a very basic adapter (or no adapter at all if pins were to be cut and the _good old_ straps were to be used), or either completely replacing both B7G sockets with two B9A sockets with only 5 pins connected for each; or even alternatively, using a single B9A or octal socket, integrated in a _new drilled _central hole between the original driver tube sockets and soldered in all the right places on the PCB - without any of this being visible outside the amp. Best of both world, you'd still have the two original B7G sockets to do whatever you want, and also a single noval or octal socket to use a single double triode if you choose too.
  
 Anyway, confirming the electrical validity of what we've been doing - despite the LD amps' apparent flexibility - would be a good idea.
  
 Sorry for the rant again, I just have too many ideas late at night, and not enough outputs to actually use them or clear them lol... Just food for thoughts for all the hardcore modders on this thread. Hell, I actually seriously considering permanently modding my amp you know; just so I could use my fav' tubes without_ any_ adapter at all.
  
 Seriously though, I'm just waiting for someone to try and add a third "central" B9A socket on their MK III or IV, or to try and replace the driver tube sockets with two B9A sockets...  I know someone will eventually try and dremel a third hole in there lol...
  
 Edit: Look on the bright side, some people just don't have limits to their tube budget... I'd been following an ebay auction for about a week, knowing very well how it would turn out, but I didn't think anyone would be crazy enough to fork out $627 for a pair of essentially un-guaranteed E88CC. Yes, Philips Heerlen; yes 1957; yes D-getter; yes pinched waist; but still... $627? For driver tubes?? Color me appalled...
  
http://www.ebay.com/itm/matched-pair-E88CC-pinched-waist-D-getters-from-philips-miniwatt-NOS-/301026417318?pt=Vintage_Electronics_R2&hash=item4616929aa6
  
 I do hope these turn out to be "god tier" tubes for the guy who bought them... Lol.


----------



## mordy

I bought my bread board from the Chinese seller/manufacturer linked above- paid $6.90 with free shipping on auction (only bidder). If you wait a little I am sure he will put it up again on the US Ebay.


----------



## gibosi

ctritical bill said:


> Here you go :
> 
> http://www.ebay.com.au/itm/1SET-8pin-K8A-tube-test-diy-Experiment-prototyping-pcb-for-6V6-EL34-KT88-6SN7-EM-/190889423497?pt=R%C3%B6hren&hash=item2c71e57289
> 
> The seller has the same board with different sockets or just the board on it's own.


 
  
 Thanks much! I have put it on my watch list for now. So if I understand correctly, it appears that when you get this board, you have to solder some kind of connector, whether it be a simple wire or a resister / capacitor / inductor between the wiring blocks and the socket before you can use it? That would explain the short red wires visible on the picture you posted. Interesting!


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## gibosi

I had a short face-off this evening between a 1965 US-Amperex 7308 and a 1964 US-Amperex 6922..... and I was unable to hear any difference between them...  At first, I was surprised. But perhaps it is not surprising at all. After all these were made in the same factory at about the same time. Further, from what I have read, the only difference is the 7308 is held to tighter specifications. So it may well be that these tubes were made on the same assembly line and the one that passed over the bar was stamped 7308 and the other was stamped 6922.
  
 If this is so, then perhaps we can hypothesize that E88CC / 6922 and E188CC / 7308 made in the same factory at the same time will sound nearly identical..... 
  
 So for now, my 1961 US-Amperex 6922 continues to hold the throne. Next up, a 1967 French-made La Radiotechnique E88CC....


----------



## Ctritical Bill

gibosi said:


> Thanks much! I have put it on my watch list for now. So if I understand correctly, it appears that when you get this board, you have to solder some kind of connector, whether it be a simple wire or a resister / capacitor / inductor between the wiring blocks and the socket before you can use it? That would explain the short red wires visible on the picture you posted. Interesting!


 
  
 Yes, that's it exactly.


----------



## Audiofanboy

gibosi said:


> I had a short face-off this evening between a 1965 US-Amperex 7308 and a 1964 US-Amperex 6922..... and I was unable to hear any difference between them...  At first, I was surprised. But perhaps it is not surprising at all. After all these were made in the same factory at about the same time. Further, from what I have read, the only difference is the 7308 is held to tighter specifications. So it may well be that these tubes were made on the same assembly line and the one that passed over the bar was stamped 7308 and the other was stamped 6922.
> 
> If this is so, then perhaps we can hypothesize that E88CC / 6922 and E188CC / 7308 made in the same factory at the same time will sound nearly identical.....
> 
> So for now, my 1961 US-Amperex 6922 continues to hold the throne. Next up, a 1967 French-made La Radiotechnique E88CC....


 
  
 That's what I thought until I read that there are supposed to be some actual physical differences between a 6922 or 7308. I can't speak for the late 60's and onwards models, but I have read that part of what made the original (Philips Holland) 7308 "premium" - or worth creating on top of the 6922 - is the anti-microphony system. On the top mica (not the third one with the getter stand), there's supposed to be one or two L-shaped "mica spring" cut-out from the mica and intended to keep the heater filament from "creating hum" or communicating noise to the cathode - _or something along those lines_.
  
 Basically, the 7308 only exits because it's a lower noise version of the 6922, which _should_ in and of itself, make it sound slightly better on paper. That, and even tighter specs, like even more matched triodes than a 6922. I would assume that the triode assemblies would be the same as the 6922 though, hence the similar sound. A noise-free 6922 made in the factory and time-frame as a anti-microphonic 7308 could/should/might sound the same. Even the 6922 is known to be or become a microphonic tube, so the 7308 was probably made to compensate for that.
  
 But like I said, I think that the differences may have been more easy to hear on the earlier production runs, before the factories would have tried to cut costs and level their production towards the end of the tube era. I'd think an early 60's 7308 Amperex made in NY _could _sound better than our early 60's NY 6922, for example. I'd also expect more marked differences in the early to mid-60's Heerlen production, somehow.
  
 I should get my E188CC by Wednesday, so I'l lhave a chance to compare tubes pretty quickly!


----------



## Kestovitutus

Hi.
 This might be silly question with all this modding and other tinkering, but has anyone any good tips how to change jumper position easily  I'm using sharp-nosed tweezers to fish them out. Not a big problem tho, because I only use one pair with EF92 setting. It's the Mk 3 with big brown nichicon capacitators? right next to jumpers.


----------



## gibosi

audiofanboy said:


> That's what I thought until I read that there are supposed to be some actual physical differences between a 6922 or 7308. I can't speak for the late 60's and onwards models, but I have read that part of what made the original (Philips Holland) 7308 "premium" - or worth creating on top of the 6922 - is the anti-microphony system. On the top mica (not the third one with the getter stand), there's supposed to be one or two L-shaped "mica spring" cut-out from the mica and intended to keep the heater filament from "creating hum" or communicating noise to the cathode - _or something along those lines_.
> 
> Basically, the 7308 only exits because it's a lower noise version of the 6922, which _should_ in and of itself, make it sound slightly better on paper. That, and even tighter specs, like even more matched triodes than a 6922. I would assume that the triode assemblies would be the same as the 6922 though, hence the similar sound. A noise-free 6922 made in the factory and time-frame as a anti-microphonic 7308 could/should/might sound the same. Even the 6922 is known to be or become a microphonic tube, so the 7308 was probably made to compensate for that.


 
  
 I can't see any L-shaped "mica springs" cut-out from the mica. But there is one very noticeable construction difference. On the 7308's top mica there is a metal plate covering almost the entire surface:
  
 6922: The top mica is largely exposed. 
  

  
  7308: The top mica is largely covered by a metal plate
  


  
 I have no doubt that the 7308 is quieter, the triodes are better matched, and, at least on paper, it should sound better. However, from my experience, I believe better test equipment and procedures are necessary to discern these differences. Sonically, these are so close that I cannot tell them apart. That said, if I could purchase a pair of 1961 US-Amperex 7308 for a good price, I would not hesitate.


----------



## Audiofanboy

gibosi said:


> I can't see any L-shaped "mica springs" cut-out from the mica. But there is one very noticeable construction difference. On the 7308's top mica there is a metal plate covering almost the entire surface:
> 
> 6922: The top mica is largely exposed.
> 
> ...


 
  
 Pictures, great, very convenient!
  
 Actually, on your third picture, I _believe _we can see one of the anti-microphony systems - what I have read are sometimes called "mica spring" - and indeed it looks like somekind of a shock absorbing mechanism, the same concept as on a car. I tried to outline the part below, but it's actually easier to see on the original picture once you've figured out where it is.
  

  
  
 No doubt that there's more Schiit on the top mica of a 7308 than on a 6922; not that the specifics matter... But I like to know why things do what they do - especially if they're going to affect sound quality!
  
 Edit: The only reason why I'm so specific on knowing about those different noise/microphony mechanisms is because I have read _over and over_ that the 6DJ8 are pretty prone to that, and even the premium 6922. Even my own Amperex 6922 has made an odd noise once or twice; but a 10s weird noise on my premium tube is enough to make me paranoid for a week, listening for noise issues instead of music lol... Not that my 6922 is noisy, it's actually dead quiet - apart from that one-shot incident.


----------



## gibosi

audiofanboy said:


> Actually, on your third picture, I _believe _we can see one of the anti-microphony systems - what I have read are sometimes called "mica spring" - and indeed it looks like somekind of a shock absorbing mechanism, the same concept as on a car. I tried to outline the part below, but it's actually easier to see on the original picture once you've figured out where it is.


 
  
 Yes, I can these "mica springs", and for sure, the 6922 doesn't have them. Further, perhaps due to all that extra metal, the 7308 feels noticeably heavier in my hand.
  
 And now I am very curious to see what the Holland-made Amperex 7308/E188CC looks like....  (Tracking indicates that it arrived in NY from France in only four days... and it sat in NY for two weeks! lol  But finally, as of today, it is on the move again.... Soon I hope.... )


----------



## Oskari

mordy said:


> So I thought that I snagged a bargain Tung Sol that just squeezed in at my $8 limit including shipping. A little research seems to indicate that they were two different factories and I could not find any information that Tung Sol acquired National Union (not to be confused with National which was the earlier name for the Japanese Matsushiita).
> 
> The only identification letters on the the tube are YT on the blackened glass, and KC on the base. KC  = December 1953? Would appreciate if anybody has information, as well as information if there is a link between NU and TS.
> 
> Would appreciate help in a possible TS-NU link, and the dating of this tube.


 
  
 I'm not aware of such a link. NU was an independent tube manufacturer, in fact an amalgamation of a number of small early tube manufacturers. NU sold its newish second plant in Lansdale, PA to Philco not long after the end of WWII. I suppose NU basically diversified out of the tube making business in the 1950s.
  
 I'm not able to help with the date codes.


----------



## Oskari

gibosi said:


> On the 7308's top mica there is a metal plate covering almost the entire surface:


 
  
 Could it be another mica sheet rather than metal?


----------



## Audiofanboy

gibosi said:


> Yes, I can these "mica springs", and for sure, the 6922 doesn't have them. Further, perhaps due to all that extra metal, the 7308 feels noticeably heavier in my hand.
> 
> And now I am very curious to see what the Holland-made Amperex 7308/E188CC looks like....  (Tracking indicates that it arrived in NY from France in only four days... and it sat in NY for two weeks! lol  But finally, as of today, it is on the move again.... Soon I hope.... )


 
  
 *cough* darn customs *cough*
  
 Yeah, I'm very curious about the European Philips E188CC for a few different reasons now. I'd expected the US 7308 to _not_ be better than the US 6922 - some versions are even supposed to sound worse - but as far as Holland tubes go, the E188CC are supposed to be equal or better to the E88CC - at least for mid to late 60's tubes, early 60's and late 50's seem to be a bit more iffy to compare, as people's opinions are all over the place (the proverbial "all those tubes are great!" which doesn't help much...).


----------



## hypnos1

Just a quickie from someone in a mild state of shock - the combination of direct soldering of headphone cable to PCB and 30+ hours on the Tesla E88CCs (gold pins AND grids from the '60s) is producing something rather magical...even more detail (especially in the upper range) and soundstage than the TFK ECC88s. Plus all the bass you could wish for, which is a nice surprise after one of our esteemed colleagues found it not quite so hot in that department. Thankfully the over-bright aspect has now toned down and is transforming into even more sparkle than before, not to mention that wonderful treble detail. These could be my new love...once more...


----------



## MIKELAP

kestovitutus said:


> Hi.
> This might be silly question with all this modding and other tinkering, but has anyone any good tips how to change jumper position easily  I'm using sharp-nosed tweezers to fish them out. Not a big problem tho, because I only use one pair with EF92 setting. It's the Mk 3 with big brown nichicon capacitators? right next to jumpers.


 
 Use long jumpers like this way easier to change


----------



## gibosi

oskari said:


> Could it be another mica sheet rather than metal?


 
  
 It very well could be another mica sheet... It has a very lustrous and smooth sheen to it, like chromed metal, but looking at the edges, I am not sure...  My cheap magnifying glass isn't all that good, and while I understand it would further the interests of our research here, I am simply unwilling to break the tube in order to be sure.


----------



## gibosi

hypnos1 said:


> Just a quickie from someone in a mild state of shock - the combination of direct soldering of headphone cable to PCB and 30+ hours on the Tesla E88CCs (gold pins AND grids from the '60s) is producing something rather magical...even more detail (especially in the upper range) and soundstage than the TFK ECC88s. Plus all the bass you could wish for, which is a nice surprise after one of our esteemed colleagues found it not quite so hot in that department. Thankfully the over-bright aspect has now toned down and is transforming into even more sparkle than before, not to mention that wonderful treble detail. These could be my new love...once more...


 
  
 I have only about 20 hours on my Tesla...  So I guess I'll have to burn them in for another 10 or 20 hours...


----------



## gibosi

audiofanboy said:


> *cough* darn customs *cough*


 
  
 It's actually a little funny... Packages from Moldova and Ukraine have been getting through customs faster than this package from France! lol  While it is probably just a random delay, it does seem a bit strange....


----------



## hypnos1

gibosi said:


> I have only about 20 hours on my Tesla...  So I guess I'll have to burn them in for another 10 or 20 hours...


 
  
 Hi g.
  
 Sincerely hope they deliver more for you - would hate to think I'm deluding myself! (They do LOOK so beautiful 
	

	
	
		
		

		
		
	


	




). But then - different set-up + tubes (even if from the same batch) : who knows?!
  
 Still keeping an eye out for some early '60s Amperexes (for not silly money), but methinks I am in for the long haul...just hope the patience doesn't run out!


----------



## Artsi

ctritical bill said:


> A better candidate in this circuit would be the 6SN7. Has anyone tried this as a driver ?


 
 Oops, i have somehow forgot totally to try my 6SN7's as a driver. This is easily fixed. They work perfectly. Gain is perhaps little bit lower than 6SL7, but this is no problem. From now on i'm really listening different 6SN7's as a driver and try to find differences.
  
 I know you guys love tube porn, so here is something to drool.
 RCA 6SN7GT

 Sylvania 6SN7GTA

 Tung-Sol 6SN7GTB


----------



## TrollDragon

Here was an interesting experiment... 12AX7 sealed in oil.

ZennAudio


> Oil sealed tube. Jan GE 12AX7. Part of an interesting experiment to find out how the tube sounded when immersed in an oil environment. Sounded great. Very quiet and dark background in the soundstage.


----------



## MIKELAP

trolldragon said:


> Here was an interesting experiment... 12AX7 sealed in oil.


 
 and smooth as a baby's butt


----------



## Ctritical Bill

Artsi, you beat me to it. I have just tried a 6SN7 and, I agree, it works perfectly and still has that fabulous soundstage of the 6SL7. Mine is a NOS Russian from 1983 and of course I took some measurements ( stock values with no added resistors ) :
  
 Heater  -  6.12v
 Plate (R) - 86.0    Grid (R) - 2.13
 Plate (L)  - 85.8    Grid (L)  - 2.13
  
 So you can see the heater voltage is down quite a bit from the 6SL7 which was 6.36v . This is the unregulated power supply doing it's thing of dropping the voltage as the current draw increases. The 6SL7 draws 300ma and the 6SN7 draws 600ma so that all makes sense. Under-volting the heaters a little is no bad thing as it increases tube life.
  
 The plate voltage is down below 100v which I think is the ideal in this circuit and it is a lot closer than the 6SL7 so a good result. Also the grid voltage is up around 2v where it should be.
 So the technical results are all very good.
  
 Speaking of ideals, in this circuit with a B+ of 200v , the ideal plate voltage would be 100v and grid 2v , which results in about 3ma through the tube. The Little Dot resistor values work to give these results as long as the tube is suitable. So if you are looking at graphs in the datasheets then you want to find tubes with graphs where the values of plate volts = 100, grid volts = 2,  and current  = 3ma roughly converge.


----------



## superdux

Can it always be seen, if a tube is faulty if you take closeup fotos? I have a matched pair voskhod tubes and one seems to be faulty, especially after switching from left to right the dropouts followed especially when i had the volume on 12 O`clock with 5 gain setting. Does this sound familiar to anyone? I couldn´t see any faulty wires that were detached and the silver lining in the tube head seemed intact too.
 The seller asked me if i could make some closeup fotos before he decides towards a refund.


----------



## Audiofanboy

ctritical bill said:


> Artsi, you beat me to it. I have just tried a 6SN7 and, I agree, it works perfectly and still has that fabulous soundstage of the 6SL7. Mine is a NOS Russian from 1983 and of course I took some measurements ( stock values with no added resistors ) :
> 
> Heater  -  6.12v
> Plate (R) - 86.0    Grid (R) - 2.13
> ...


 
  
 I've been looking at driver tube datasheets for over a year - since we started this non-native tube rolling silliness - and everytime I looked at graphs, I never really knew what values to use a base (though the graphs were still useful for misc. reasons). These values are actually pretty convenient to have, thanks!


----------



## mordy

Hi TrollDragon,
  
 So basically this is an oil cooled tube. In the past I found that having a de-commissioned computer fan blow on the tube (actually drawing air away from the tube) on a hot summer day was detrimental to the sound if the tube got too cool. Apparently the tube needs a certain temperature to function properly. It should not be a problem with the oil, since one has to assume that it heats up somewhat.
  
 I am sure that for an all American GE tube corn oil was used. The next step would be to put in an Amperex Herleen tube and surround it with Special Reserve Cold Pressed Extra Virgin Olive Oil. Wonder if different oils have different effects on the sound.
  
 For those who prefer a wetter more sparkly sound, may I suggest Perrier sparkling mineral water.
  
 For the car enthusiasts out there, I think that the Toyota OEM red radiator fluid would look good. Seriously, we need research here if the best sounding oil is a 5-20W or a straight 50 weight oil. (I know that there are protagonists for both.) And yes, we got to try Johnson's baby oil as well.
  
 DISCLAIMER: This is an international forum, and we all come from different cultures and react differently to different inputs (just like tubes). What I wrote here was NOT intended to make fun of this interesting experiment, but to try to be funny, exploring the LOL quotient.


----------



## gibosi

ctritical bill said:


> So you can see the heater voltage is down quite a bit from the 6SL7 which was 6.36v . This is the unregulated power supply doing it's thing of dropping the voltage as the current draw increases. The 6SL7 draws 300ma and the 6SN7 draws 600ma so that all makes sense. Under-volting the heaters a little is no bad thing as it increases tube life.
> 
> The plate voltage is down below 100v which I think is the ideal in this circuit and it is a lot closer than the 6SL7 so a good result. Also the grid voltage is up around 2v where it should be.
> So the technical results are all very good.
> ...


 
  
 Doesn't the fact that the 6SN7 draws 600ma present a problem? I have been under the impression that the LD's limit is about 500ma?


----------



## gibosi

superdux said:


> Can it always be seen, if a tube is faulty if you take closeup fotos? I have a matched pair voskhod tubes and one seems to be faulty, especially after switching from left to right the dropouts followed especially when i had the volume on 12 O`clock with 5 gain setting. Does this sound familiar to anyone? I couldn´t see any faulty wires that were detached and the silver lining in the tube head seemed intact too.
> The seller asked me if i could make some closeup fotos before he decides towards a refund.


 
  
 I certainly do not possess the skills necessary to study close-up pictures of a tube and determine why it doesn't work properly, but maybe this vendor can? I very much doubt it...  Even so, it's easy to send him the pics he is requesting, so give him what he wants. However, if he decides there is nothing wrong, don't give up. Keep demanding a refund. Cheers.


----------



## TrollDragon

Yes mordy the different oils would add an interesting flavor or longevity to the tube especially with some of the newer Synthetic's.

Toss a few bay leaves in there with some herbs and a garlic bud or two... This will increase the WAF (Wife Approval Factor) at least ten fold.

4 of the 5 on that site had leaked, so that would be a fine mess to clean out of the amp. A nice high temp silicone should keep the oil in place though.

Now this is an extension on the oil only for the most experienced modder... 



Lava Lamp Bottle!


----------



## superdux

Thx for reply gibosi


----------



## Ctritical Bill

gibosi said:


> Doesn't the fact that the 6SN7 draws 600ma present a problem? I have been under the impression that the LD's limit is about 500ma?


 

 No, not at all. Using a pair of EF91 in the conventional way draws 600ma total as well. I think it was TrollDragon who posted a photo of the LD transformer and the heater winding was labelled 6.6v @ 1 amp so well within the limit.


----------



## gibosi

ctritical bill said:


> Artsi, you beat me to it. I have just tried a 6SN7 and, I agree, it works perfectly and still has that fabulous soundstage of the 6SL7. Mine is a NOS Russian from 1983 and of course I took some measurements ( stock values with no added resistors ) :
> 
> Heater  -  6.12v
> Plate (R) - 86.0    Grid (R) - 2.13
> Plate (L)  - 85.8    Grid (L)  - 2.13


 
  
 Would you be willing to provide a primer on how to make these measurements? My system, with a breadboard 9-pin socket and 7-pin Vectors, certainly provides full access. However, I have no good idea how to make these measurements.
  
 Also, in case it makes a difference, I have an LD 1+, which is a hybrid amp, and it is my understanding that the tube stage is configured as a cathode follower.....
  
 Are these AC Volt measurements? or the DC?
  
 If I put the one of the meter's probes on Vector pin 3, one of the heater pins, where do I put the other probe? Pin 4? Somewhere else?
  
 In the same vein, if I put one of the meter's probes on Vector pin 5, the plate, where do I put the other probe?
  
 And the same question for the grid?
  
 Further, is there anything else you think a rank amateur should know?
  
 Thank you!


----------



## gibosi

ctritical bill said:


> No, not at all. Using a pair of EF91 in the conventional way draws 600ma total as well. I think it was TrollDragon who posted a photo of the LD transformer and the heater winding was labelled 6.6v @ 1 amp so well within the limit.


 
  
 I see.... this makes sense.... the limit is really 500ma per side. And so with these double triodes, 600ma is equivalent to running two 300ma tubes. Thanks!


----------



## mordy

Hi superdux,
  
 Before you return the tubes, try to gently scrape the pins on the bad tube. Sometimes there is a little oxidation or dirt on the pins and you don't get a good connection. A small knife blade or something similar will do - does not have to be very sharp.
  
 I had a 6N6P power tube sitting for a year and a half thinking that it had died on me. One day I thought of scraping the pins and it came back to life again.


----------



## mordy

Hi Oskari,
  
 Thanks for clearing up the separate origin of National Union tubes. My tube is in prolonged use and suddenly I realized that the softness in the bass has tightened up after some 60 hours. Based on the following, perhaps we can place this tube in the 40's:
  
National Union 
*These are all very old tubes as National Union disappeared shortly after the war.  Therefore most all of them were made during the 1940's.  They have the gray colored coating inside the glass so the plates are hidden from view.  I haven't had the heart to break one in order to describe the plate structure, so you will have to wait until I break on by accident!  Many of these tubes are in military packaging but do not carry the "W" designation as I believe that the "W" designation didn't come until after the war.  Great sounding......very short supply.  Only a few on hand today.*

 *Type*
 *Description*
  
*National Union* *6SL7GT  *
*Early 40's version. Gray or Black Glass*


----------



## TrollDragon

From looking at the label on the transformer...

  
 Driver Filament - 3.3V*2/1A | Green Black Green.
  
 If you follow the Driver filament wires back to the toroidal transformer, you will find that they seem to be two parallel windings going inside the transformer, with a single center tap wire connected to the board on a solder pad marked 1/2 f. This would lead me to believe that there is 1A shared between the two pairs or 500mA each.
  
 The Power tube filament wires also go back inside the transformer for a 2.5A split between the two pairs or 1.25A each.
  
 The only way to tell if these are parallel windings or a single winding with two pairs of wires attached would be to measure the Power tube filament pairs and see if there is zero ohms between any of them. If there is only a higher resistance between each wire in the pair, then it is a parallel winding. If there is a Zero ohm reading between one wire from the left socket and one wire from the right, then it is just a single winding with two pairs attached.
  
 You can't measure the same way between the Driver filament pairs because of the single center tap wire.


----------



## Kestovitutus

mikelap said:


> Use long jumpers like this way easier to change


 
  
 Much obliged, MIKELAP


----------



## Kestovitutus

Hmm.. I have problem with two of mine tubes

 Tesla 6F36/6AH6/6J5P
 6J4P/6AU6/EF94 no idea who made these, russian.
  
 Both pentodes.. Are they incompatible with ld?
 I run them with 2/7 wire mod, but all I get is this very faint sound when volume is turned to max.
 Sounds bit like if I listened turntables cartridge without any amps on. +the teslas create this "fire-ish" sound on other channel.


 I have also ran successfully 6K4P-EV /6BA6 tubes, which I rank very highly among my tubes, with 2/7 wire mod with no problems.


----------



## TrollDragon

You don't have the jumper in EF92 mode with the 6AH6 and a 2-7 jumper as well do you? That would short the plate, grid and cathode all together.

6AH6's need to be run in EF95 mode with a 2-7 jumper, that is the only way they work.

Check the table on page 77 for settings.


----------



## superdux

Thx mordy, will certainly try that suggestion out!


----------



## Audiofanboy

trolldragon said:


> From looking at the label on the transformer...
> 
> Driver Filament - 3.3V*2/1A | Green Black Green.
> 
> ...


 
  
 Oh, I'd forgotten there was a entire 1A dedicated to the driver tube heaters, I kept thinking the values were lower for some reason...
  
 Would - temporarily - plugging a since double triode with a heater current draw of around 850 mA - on only one side since it's a single tube - be a terrible idea then?
  
 I keep reading how the 6NP6 & especially the 6N30P can make great driver tubes, but I haven't even dared to try a 6N30 in the driver position yet because of its high current draw; its low mu and very high gm being a separate issue. Would it unreasonable to draw 850 mA from only one of the two driver sockets?
  
 Similarly, I'd never noticed this pretty important electrical difference between a 6SL7 and a 6SN7. The fact that the 6SN7 draws 600 mA from a single socket may be a cause for concern compared to its higher mu counterpart that only uses half that. Then again, many here have run two separate 450 mA tubes (so a 900 mA or more current draw) for months without issues, so I guess the amp could use the whole 1A if needed...


----------



## TrollDragon

The problem with the filament windings is I really don't know if it would be safe to draw the whole 1A through one side or not. It all depends on the AWG of the wire used in the windings. If they designed this transformer so that each side only provided 500mA then drawing more than that would overheat the winding and one of the wires would burn open.

This transformer is custom made for LD so I am not sure if they would sell you a replacement or not, I have searched for a compatible replacement but I could not find any, it would have to be a custom wind, or you would have to find something that would fit the case and then modifications to all the heater connections would have to be done.

If you wanted to try high filament current tubes you can just roll the dice and hope you don't burn out your transformer or parallel the drivers heater wires together but that would require a scope to make sure the phase is correct. Pin 3&4 on all the different amps might not be hooked up the same way as there is no distinct markings on the wires.

Pick up a Crack or a Darkvoice as they would be some much easier to play with octals IMHO.


----------



## Kestovitutus

trolldragon said:


> You don't have the jumper in EF92 mode with the 6AH6 and a 2-7 jumper as well do you? That would short the plate, grid and cathode all together.
> 
> 6AH6's need to be run in EF95 mode with a 2-7 jumper, that is the only way they work.
> 
> Check the table on page 77 for settings.


 
 Well I have used that chart as an reference when shopping for tubes. It actually has the tubes I mentioned in a nice row. I've ran them all in EF95 with the 2-7 wire with 0.33 success rate.


----------



## Audiofanboy

kestovitutus said:


> Well I have used that chart as an reference when shopping for tubes. It actually has the tubes I mentioned in a nice row. I've ran them all in EF95 with the 2-7 wire with 0.33 success rate.




I have a very vague recollection that the Russian 6AH6 equivalents were slightly different tubes, that weren't without issues... You may want to try and grab a datasheet for those exact tubes on google to check whether they can be 2-7 strapped like the regular 6AH6.


----------



## Nic Rhodes

anyone tried any of the French 6AM6S / 6064 by Thomson / CSF / Minatron? They look very nice tubes.


----------



## Audiofanboy

nic rhodes said:


> anyone tried any of the French 6AM6S / 6064 by Thomson / CSF / Minatron? They look very nice tubes.




I wouldn't bother with these... My limited experience with similar Thomson CSF tubes was pretty mixed (very microphonic and weak glass).

If you want nice EF91 tubes - the best actually - try the GEC CV4014.


----------



## Nic Rhodes

I have shed loads of GECs EF91s and know them well but am more interested in finding out about these French tubes. They are beautifully made items (certainly not weak glass, quite the opposite), well presented smart looking, I was wondering if anyone had tried them.


----------



## Ctritical Bill

trolldragon said:


> The problem with the filament windings is I really don't know if it would be safe to draw the whole 1A through one side or not. It all depends on the AWG of the wire used in the windings. If they designed this transformer so that each side only provided 500mA then drawing more than that would overheat the winding and one of the wires would burn open.
> 
> This transformer is custom made for LD so I am not sure if they would sell you a replacement or not, I have searched for a compatible replacement but I could not find any, it would have to be a custom wind, or you would have to find something that would fit the case and then modifications to all the heater connections would have to be done.
> 
> ...


 
  
 This is a very valid point that you bring up about the transformer.
 We just don't know whether there are separate windings for each driver tube or not.
 I found this interesting page on heaters : http://www.valvewizard.co.uk/heater.html and this part seems relevant : "*Transformer centre tap:* The traditional way to reduce hum is to use a heater supply with a centre tap and connect it to ground." That would appear to be what we have in the LD. And if LD went to the trouble of getting a custom transformer made which included a centre-tapped heater winding, then perhaps they ran separate wires to each tube (thus reducing current in each wire) also to reduce hum. The fact that there are separate pairs of wires to each tube is the perplexing part but if they were separate windings I would imagine the transformer would label them as such.
 I ran my amp for an hour and a half last night and the body didn't get any hotter than usual although I didn't feel the temperature of the transformer cover. Also I think I might expect a bigger voltage drop if the 600ma tube was working from a 500ma supply.
  
 I guess we just can't say for sure how the heater supply is connected so everyone should be aware there might be a problem using tubes requiring filament currents higher than 500ma.


----------



## Oskari

mordy said:


> Based on the following, perhaps we can place this tube in the 40's:


 
  
 Either that or 50s. I can't say which one.


----------



## mordy

_Either that or 50s._
  
 I have this notion that older tubes were better made, but perhaps it is tied to certain brands that became lower in quality as time went on. In any case, these old NU tubes keep on improving with use - now up to around 75 hours. Sound stage, sizzling cymbals, sweet mid range, slam ... I'm running out of esses sssss
  
 What is so interesting is that we now have tubes that sound excellent in the LD, and it becomes a case of personal preferences what you like rather than picking the tube that has the least shortcomings.
  
 However, every time I think that we have reached the summit, something new and better turns up!


----------



## Audiofanboy

nic rhodes said:


> I have shed loads of GECs EF91s and know them well but am more interested in finding out about these French tubes. They are beautifully made items (certainly not weak glass, quite the opposite), well presented smart looking, I was wondering if anyone had tried them.


 
  
 In the first 10-15 pages of this thread someone (don de luca or don luca or whatever) tried supposedly French 6AM6S tubes, so you may be able to find impressions there. Not that I would even bother with EF91 anymore considering everything else out there, but that's just me  , those tubes are still interesting in their own right (and happen to kick the amp's ass with high mu _and_ high gm; these make the amp piping hot actually) .


----------



## gibosi

trolldragon said:


> The problem with the filament windings is I really don't know if it would be safe to draw the whole 1A through one side or not. It all depends on the AWG of the wire used in the windings. If they designed this transformer so that each side only provided 500mA then drawing more than that would overheat the winding and one of the wires would burn open.
> 
> This transformer is custom made for LD so I am not sure if they would sell you a replacement or not, I have searched for a compatible replacement but I could not find any, it would have to be a custom wind, or you would have to find something that would fit the case and then modifications to all the heater connections would have to be done.
> 
> If you wanted to try high filament current tubes you can just roll the dice and hope you don't burn out your transformer or parallel the drivers heater wires together but that would require a scope to make sure the phase is correct. Pin 3&4 on all the different amps might not be hooked up the same way as there is no distinct markings on the wires.


 
  
 So if I wanted to feel comfortable rolling 600ma double triodes, one possible solution is to parallel the heater wires together, that is, tie pin 3 on the left and right Vectors together and pin 4 likewise. However, there is a chance that these connections might be out of phase..... and I do not have an o'scope.... 
  
 So a couple questions:
  
 1) If connected out of phase and powered up, is there risk of damaging the tube and/or amp?
  
 2) If there is no risk of damage, is it likely that one could tell empirically if the wires are connected in phase? Perhaps an out-of-phase connection would sound different, perhaps worse? If so, would this seem to be a reasonable course of action?
  
 Thanks!


----------



## MIKELAP

This is the final version of 6 v. adaptor  for 6DJ8 tubes.


----------



## TrollDragon

Hey Gibosi!

If the windings are not connected in the proper phase and there is a small difference in the resistance of both windings the transformer will cook itself to failure. With today's toroidal core transformers the chances of a resistance mismatch is slim since the windings are wound at the same time. I could not possibly guarantee success or failure based on a few numbers off of a questionably made Chinese transformer.

The Chinese are well known for their lack of documentation and quality control.

Since you are running external tubes from a breadboard, I personally would locate on the internet a 120V Primary / 6.3V 2A Secondary transformer that you can hook up to AC and power which ever tubes you wish.

Basically you are moving the driver filament power off of the amp.


----------



## gibosi

trolldragon said:


> Since you are running external tubes from a breadboard, I personally would locate on the internet a 120V Primary / 6.3V 2A Secondary transformer that you can hook up to AC and power which ever tubes you wish.


 
  
 Thank you for making sure I don't break my LD! 
  
 However, as I still have plenty of tubes to roll that are perfectly safe to run in the LD, I think I will file this idea away until the time comes that my itch to run these higher current tubes becomes intolerable! lol
  
 Thanks again!


----------



## TrollDragon

You are most welcome gibosi!

I would hate to read about someone burning out there amp or even worse expensive headphones, all on the chance that a $35 tube went south or was shorted right from the start.

Always test new tubes with a disposable pair of headphones, it's better to be safe than sorry.

All the pioneers like yourself and others in this thread who have broken new ground and rolled tubes not even imagined are to be commended.

Bravo guys, job well done!


----------



## Audiofanboy

gibosi said:


> Thank you for making sure I don't break my LD!
> 
> However, as I still have plenty of tubes to roll that are perfectly safe to run in the LD, I think I will file this idea away until the time comes that my itch to run these higher current tubes becomes intolerable! lol
> 
> Thanks again!


 
  
 The urge will come...
  
 I mean, look at all of us on this thread lol! No one has ever resisted an _urge_ yet.
  
 And yeah, I'm itching to try a 6N30P in the driver position myself....


----------



## MIKELAP

Was checking code on Orange Globe tube and i noticed that behind where its written made in Holland theres this  GAC and below 47k2 and other tube is GAB and 47A5 is that a date anybody know these codes. Thanks


----------



## gibosi

mikelap said:


> Was checking code on Orange Globe tube and i noticed that behind where its written made in Holland theres this  GAC and below 47k2 and other tube is GAB and 47A5 is that a date anybody know these codes. Thanks


 
 GA = 6DJ8 / ECC88
  
 C and B are change codes. The earliest change codes were represented with numbers, and after the number 9, letters. You might consider this a "version number" So one tube is version B and the other is version C.
  
 4 = Heerlen, Holland. It is actually a triangle on its side, many refer to this character as a "delta"
 7 = 1967
 A - L = Month... so A = January and K = November
 1 - 5 = week of the month.
  
 So both tubes were manufactured in the Heerlen, Holland factory in 1967, one in January and one in November.


----------



## Ctritical Bill

gibosi said:


> Would you be willing to provide a primer on how to make these measurements? My system, with a breadboard 9-pin socket and 7-pin Vectors, certainly provides full access. However, I have no good idea how to make these measurements.
> 
> Also, in case it makes a difference, I have an LD 1+, which is a hybrid amp, and it is my understanding that the tube stage is configured as a cathode follower.....
> 
> ...


 
  
 Heater Voltage - Set your meter to Volts AC , put one probe on pin 3 , the other on pin 4.
 Plate Voltage - Set your meter to Volts DC , put the red probe on pin 5, the black probe to Ground. On the MK111 the best place for ground is the case screw next to the right hand driver tube. Not sure about the LD 1+ but a convenient place on the case should be fine.
 Grid Voltage - Set your meter on Volts DC , put the red probe on pin 2 , the black probe to Ground. This is actually measuring the cathode bias voltage but at idle the grid is 0 volts so this amounts to the same thing.
  
 Be very careful when taking measurements not to short out adjacent pins and normal disclaimers of at your own risk applies of course.
  
 The output stage of the LD 1+ is different as you say, so I don't know what effect a plate voltage greatly different from the norm will have on the sound.


----------



## gibosi

ctritical bill said:


> Be very careful when taking measurements not to short out adjacent pins and normal disclaimers of at your own risk applies of course.


 
  
 Thank you! I will try to take some measurements on a few E88CC and E188CC  over the next day or two and post them. Cheers.


----------



## gibosi

audiofanboy said:


> The urge will come...


 
  
 lol...yes I am sure it will come! 
  
 And it seems to me that when I get an external transformer to power the heaters, I may as well get one with a 12.6 volt tap as well. I assume that there might be some nice 12.6 volt double triodes we haven't been able to try yet?


----------



## gibosi

This morning, measured a 1967 La Radiotechnique E88CC running in an LD 1+:
  
 Heater  -  6.7v
 Plate (R) - 84.6    Grid (R) - 2.90
 Plate (L)  - 84.6    Grid (L)  - 2.86


----------



## Audiofanboy

gibosi said:


> This morning, measured a 1967 La Radiotechnique E88CC running in an LD 1+:
> 
> Heater  -  6.7v
> Plate (R) - 84.6    Grid (R) - 2.90
> Plate (L)  - 84.6    Grid (L)  - 2.86


 
  
 Well, these look like pretty good values to me; it just goes towards confirming that the 6DJ8 types are well suited for the amp.
  
 That heater value doesn't seem so good though... It's beyond the +/- 5% acceptable range. While it's probably not dramatic, it may very well be high enough to shorten the tube's life over time. Staying within 6.3V +5% would be better - a value lower than 6.3V -5% might just make tube not sound as good but not damage it.
  
 After reading the comments here about how a higher filament current draw seems to lower the filament tension somewhat, I'm thinking that's yet another reason to just use two separate double triodes - despite it being wasteful of tubes and power. I'm wondering if going below 300 mA of current could be "bad" if it doesn't create enough of the "load" to have filament tension within specs. At least, a 6DJ8 (365 mA) or a 7308/E188CC (335 mA) stays closer to the current draw two 6AK5 tubes (2 x 175 mA = 350 mA) would have; a 6922/E88CC actually goes below that.
  
 Curious as to how the readings would turn out on a MK III or IV now. It was definitely a good call to start getting measurements, if only to err on the side of caution...


----------



## mordy

Hi Ctritical Bill,
  
 If I understand correctly, the measurements you list are for 6DJ8 tubes. Would taking measurements for 12AX7 and octal tubes use different pins?
  
 If i had the tube on a breadboard, can I measure voltages at the breadboard connectors? (Seems safer)


----------



## gibosi

Finally! A Dario-branded, Heerlen, Holland-made E188CC, VR2 40H3, arrived in today's mail from France. After a quick inspection, it appears to have the same construction as the US-made Amperex 7308, as one would expect.
  
 When I took the package out of the mailbox, I noticed that something was rattling around inside the box. Sure enough, the tube had slipped out of the bubble wrap and as the packing material was very sparse, the naked tube was rolling around in the box. (>_<) However, plugged it in, fired it up and all seems well. One very tough tube it seems... burning in as I write this....


----------



## MIKELAP

Now for the 12v. adaptor, if i remember correctly the 6su7 octal works both with 6v. and 12 v. am i wright ,and now for the 12ax7 tubes dont have any of those i wread the thread a bit and found the 5751 triple mica to be a good tube would anybody have any ideas regarding good 12ax7 tubes brand and style or are the 6DJ8 just better overall than the 12ax7 and they are not worth getting into. Thanks


----------



## mordy

Hi Mikelap,
  
 Tried several 12AX7 tubes - the only one I really like is an early 1960s Sylvania that sounds very good. In general, it could be that the 6DJ8 family of tubes sounds better on the LD amps.
  
 Now I have this single 1940-50s  octal National Union 6SL7 which is getting better and better. After about 100 (!) hours of burn in the bass is getting more and more distinct and powerful and the detail, imaging and sound stage all have improved. An absolutely delicious tube!


----------



## Proglover14

Very nice post, thanks for all the hard work!


----------



## Ctritical Bill

mordy said:


> Hi Ctritical Bill,
> 
> If I understand correctly, the measurements you list are for 6DJ8 tubes. Would taking measurements for 12AX7 and octal tubes use different pins?
> 
> If i had the tube on a breadboard, can I measure voltages at the breadboard connectors? (Seems safer)


 
  
 The instructions I gave were for the pins of a socket 7 tube. The principle is the same for any tube you just have to identify what each pin is connected to. The best place to take measurements is the most convenient to your setup so the breadboard connections would probably be best.


----------



## gibosi

audiofanboy said:


> Well, these look like pretty good values to me; it just goes towards confirming that the 6DJ8 types are well suited for the amp.
> 
> That heater value doesn't seem so good though... It's beyond the +/- 5% acceptable range. While it's probably not dramatic, it may very well be high enough to shorten the tube's life over time. Staying within 6.3V +5% would be better - a value lower than 6.3V -5% might just make tube not sound as good but not damage it.


 
  
 Yes, 6.7v would seem to be a bit high, but if I understand things correctly, this is a function of the mains and the LD transformer, not the tube. I live in 120volt land and I measure 122v at the wall. Again, if I understand correctly, the transformer simply converts this to 6.7v. Perhaps if my mains was closer to 115VAC, the heater voltage would be correspondingly lower?
  
 A 1960 Heerlen, Holland E188CC running in an LD 1+:
  
 Heater  -  6.7v
 Plate (R) - 81.5    Grid (R) - 3.1
 Plate (L)  - 81.5    Grid (L)  - 3.1


----------



## gibosi

ctritical bill said:


> The instructions I gave were for the pins of a socket 7 tube. The principle is the same for any tube you just have to identify what each pin is connected to. The best place to take measurements is the most convenient to your setup so the breadboard connections would probably be best.


 
  
 For me, it is easiest and most convenient to take these measurements off of the 7-pin Vectors because no matter what tube I use, be it 6DJ8, 12AX7, 6SL7 or 2C51, the measurements are taken at the exact same pins, namely 2, 3, 4 and 5. If I make measurements at the 9-pin socket, I have to pay close attention to how the two triodes and the heater are connected, as they are slightly different for each of these tubes. But of course, YMMV.


----------



## gibosi

mikelap said:


> Now for the 12v. adaptor, if i remember correctly the 6su7 octal works both with 6v. and 12 v. am i wright ,and now for the 12ax7 tubes dont have any of those i wread the thread a bit and found the 5751 triple mica to be a good tube would anybody have any ideas regarding good 12ax7 tubes brand and style or are the 6DJ8 just better overall than the 12ax7 and they are not worth getting into. Thanks


 
  
 In my opinion the 12AX7 / 5751 tubes, and even the 6SL7s, are not worth your time and money. I believe that the 6DJ8 are unquestionably superior, at least in our LDs, But again, this is only my opinion....


----------



## Audiofanboy

gibosi said:


> Yes, 6.7v would seem to be a bit high, but if I understand things correctly, this is a function of the mains and the LD transformer, not the tube. I live in 120volt land and I measure 122v at the wall. Again, if I understand correctly, the transformer simply converts this to 6.7v. Perhaps if my mains was closer to 115VAC, the heater voltage would be correspondingly lower?
> 
> A 1960 Heerlen, Holland E188CC running in an LD 1+:
> 
> ...


 
  
 Be that as it may, anything over 6.6V does strike me as "not so good over the long term"... Maybe a simple resistor on the heater wire path could eversoslightly lower that voltage?
  


gibosi said:


> In my opinion the 12AX7 / 5751 tubes, and even the 6SL7s, are not worth your time and money. I believe that the 6DJ8 are unquestionably superior, at least in our LDs, But again, this is only my opinion....


 
 Oh.
  
 Well... I guess that just answers a few questions right there lol... Hopefully the 2C51 may be able to hold a candle to the all-mighty 6DJ8 so we can at least have some alternative?
  
 Then again, I keep marveling at both how good the 6922 and 7308 are, all in all, and how well they work in my LD... I only have 10 hours on my - one of my two - Philips 1960 E188CC, and I can already tell how these how very very very rugged and nice tubes. Even after 3 hours, the detail in the treble and sense of air (see the comments on the RTC E188CC over on the Lyr thread) were impressive. I haven't had a chance to listen to the tube that critically yet, not with music at least, but after 10-12 hours, I am hearing something I like!


----------



## MIKELAP

Can octals be used either in 6v.or 12 v. adaptors not shure .Thanks


----------



## gibosi

mikelap said:


> Can octals be used either in 6v.or 12 v. adaptors not shure .Thanks


 
  
 We need to know more about your system...
  
 I purchased a 6SL7 to 12AX7 adapter. With that, I configured my breadboard socket to run a 12AX7 in 6volt mode, and simply plugged it in. If you have a similar adapter, then this is all you have to do. If you are using an actual octal socket, then it will be necessary to look at a data sheet to see how to properly configure that socket.....


----------



## gibosi

audiofanboy said:


> Be that as it may, anything over 6.6V does strike me as "not so good over the long term"... Maybe a simple resistor on the heater wire path could eversoslightly lower that voltage?


 
  
 I have been thinking the same thing, but before I start groping and fumbling around, I am hoping that Ctritical Bill and TrollDragon will weigh in on this....
  


audiofanboy said:


> Well... I guess that just answers a few questions right there lol... Hopefully the 2C51 may be able to hold a candle to the all-mighty 6DJ8 so we can at least have some alternative?


 
  
 I have made a few attempts to grab a Western Electric 369A, but each time I have been seriously outbid. I figure that eventually I will get lucky so will keep bidding until I can get one at a good price.


----------



## Audiofanboy

gibosi said:


> I have been thinking the same thing, but before I start groping and fumbling around, I am hoping that Ctritical Bill and TrollDragon will weigh in on this....
> 
> 
> I have made a few attempts to grab a Western Electric 369A, but each time I have been seriously outbid. I figure that eventually I will get lucky so will keep bidding until I can get one at a good price.


 
  
 Laugh all you want, but I actually _had_ a Western Electric JW 396A at one point.
  
 I got it in the same bundle of tubes I got that mil-spec "flying 12AT7" Mullard from. Perfect silk writing and pins, no reason to think it didn't work. So I put it up for sale fairly cheap, clearly stating that I didn't have the means to test it - and that I'd take it back if it didn't work.
  
 Long story short, _obviously_, the tube didn't work properly (or so the buyer said, but he claimed that only one triode worked before explaining that the other triode worked when he flicked the tube, so I always had a doubt as to wherein the problem really lied), and I had to both pay the fellow back, lose the paypal and shipping fees, _and_ not get my beautiful rare - albeit not functional - tube back...
  
 I now regret even trying to sell the tube... Both for testing purposes, and also for "collection" purposes...


----------



## MIKELAP

gibosi said:


> We need to know more about your system...
> 
> I purchased a 6SL7 to 12AX7 adapter. With that, I configured my breadboard socket to run a 12AX7 in 6volt mode, and simply plugged it in. If you have a similar adapter, then this is all you have to do. If you are using an actual octal socket, then it will be necessary to look at a data sheet to see how to properly configure that socket.....


 
 Yes i forgot about that i have 2 6SL7 to 12ax7adapters on the slow boat from China that i will plug in the 6DJ8 adaptor i just made so its 6 volts thanks gibosi.


----------



## gibosi

mikelap said:


> Yes i forgot about that i have 2 6SL7 to 12ax7adapters on the slow boat from China that i will plug in the 6DJ8 adaptor i just made so its 6 volts thanks gibosi.


 
  
 Since your shiny new copper adapter is configured for 6DJ8 tubes, I don't think this will work...  
  
 The heater connections are different for the 6DJ8 and 12AX7. Since your socket is configured for 6DJ8 tubes, it will be necessary to reconfigure pins 4, 5 and 9 on your 9-pin socket to use 12AX7 and 6SL7 tubes.
  
 Like so:
  
 http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/3630#post_9911760
  
 Can you do this?


----------



## gibosi

gibosi said:


> I have made a few attempts to grab a Western Electric 369A, but each time I have been seriously outbid. I figure that eventually I will get lucky so will keep bidding until I can get one at a good price.


 
  
 Well color me surprised!  I just won one... and at a pretty good price - $12 plus $5 shipping. In a few days, I hope to be able to see how one of the best of the 2C51 compares to some of the best of the 6DJ8.


----------



## TrollDragon

Hey gibosi

Pricklely Peete in this thread has done some major mods to his amp improving the sound totally.

He also suffers from a mains voltage of 127V which brings his filaments up to 6.9 or 7. He solved this issue by putting a 1 ohm 3W resistor in series with the filament which dropped it .5V I think this is something you should look into as well to improve the longevity of your tubes. Running them at 6.2 or 6.1 will definitely make them last longer.

Here is the link, info is about halfway down.
 www.head-fi.org/t/439449/little-dot-mk-iii-mods/15#post_5938548


----------



## MIKELAP

gibosi said:


> Since your shiny new copper adapter is configured for 6DJ8 tubes, I don't think this will work...
> 
> The heater connections are different for the 6DJ8 and 12AX7. Since your socket is configured for 6DJ8 tubes, it will be necessary to reconfigure pins 4, 5 and 9 on your 9-pin socket to use 12AX7 and 6SL7 tubes.
> 
> ...


 
 Yes i can i have the shematics already ive waited so long to get the parts i didnt remember that anymore so thats why i had to make the 12v. adapter 
	

	
	
		
		

		
			





 at least one of us is still with it .Thanks again for clearing that up my friend.


----------



## gibosi

trolldragon said:


> He also suffers from a mains voltage of 127V which brings his filaments up to 6.9 or 7. He solved this issue by putting a 1 ohm 3W resistor in series with the filament which dropped it .5V I think this is something you should look into as well to improve the longevity of your tubes. Running them at 6.2 or 6.1 will definitely make them last longer.
> 
> Here is the link, info is about halfway down.
> www.head-fi.org/t/439449/little-dot-mk-iii-mods/15#post_5938548


 
  
 Thank you!! 
  
 To be sure I understand... Running just one double triode and supplying power to that tube as we have been doing through one of the Vectors, I would need only one of these resisters, connected in series to either Vector pin 3 or 4?


----------



## TrollDragon

gibosi said:


> Thank you!!
> 
> To be sure I understand... Running just one double triode and supplying power to that tube as we have been doing through one of the Vectors, I would need only one of these resisters, connected in series to either Vector pin 3 or 4?


 
 Yes that is correct, his voltage is 127 and yours is only 122 so the 1 ohm might be too much, you can also get .5 ohm ones or in a pinch you can join two 1 ohm in parallel to give you .5 ohm.
  
 I would pick up some axial lead 1 Ohm 3 Watt 1% from a local electronics supplier or Mouser / Digikey or eBay similar to these.
  
 You could use 5 Watt but they are starting to get a little large.


----------



## gibosi

trolldragon said:


> Yes that is correct, his voltage is 127 and yours is only 122 so the 1 ohm might be too much, you can also get .5 ohm ones or in a pinch you can join two 1 ohm in parallel to give you .5 ohm.
> 
> I would pick up some axial lead 1 Ohm 3 Watt 1% from a local electronics supplier or Mouser / Digikey or eBay similar to these.
> 
> You could use 5 Watt but they are starting to get a little large.


 
  
 Thanks again! 
  
 I have a pretty decent electronic supply store close by, so hope to get these tomorrow.


----------



## gibosi

gibosi said:


> In my opinion the 12AX7 / 5751 tubes, and even the 6SL7s, are not worth your time and money. I believe that the 6DJ8 are unquestionably superior, at least in our LDs, But again, this is only my opinion....


 
  


audiofanboy said:


> Oh.
> 
> Well... I guess that just answers a few questions right there lol... Hopefully the 2C51 may be able to hold a candle to the all-mighty 6DJ8 so we can at least have some alternative?
> 
> Then again, I keep marveling at both how good the 6922 and 7308 are, all in all, and how well they work in my LD... I only have 10 hours on my - one of my two - Philips 1960 E188CC, and I can already tell how these how very very very rugged and nice tubes. Even after 3 hours, the detail in the treble and sense of air (see the comments on the RTC E188CC over on the Lyr thread) were impressive. I haven't had a chance to listen to the tube that critically yet, not with music at least, but after 10-12 hours, I am hearing something I like!


 
  
 Maybe I should explain my thinking...  The Sylvania 5751 TMBP and the Tung-Sol JAN-CTL-6SU7GTY are very good tubes, among the best of their breed. But in my opinion, they are not as good as the 6922/E88CC and 7308/E188CC I have been listening to recently. Given that, on eBay the Sylvania and Tung-Sol have typically been going for around $50. On the other hand, I have paid in the neighborhood of $30 to $50 each for the eight 6922 and 7308 I have. So if one is willing to spend $50, I would absolutely recommend a nice 7308. But if the Sylvania and Tung-Sol can be gotten for $25 to $30 each, then by all means, grab them. Cheers.


----------



## Audiofanboy

gibosi said:


> Well color me surprised!  I just won one... and at a pretty good price - $12 plus $5 shipping. In a few days, I hope to be able to see how one of the best of the 2C51 compares to some of the best of the 6DJ8.


 
  
 Nice! Hopefully that'll directly settle whether or not it's worth pursuing that tube type without spending any more cash.
  
 As much as those tube rolling adventures have been very pleasant (and still are right now), I do like the feeling that we're "wrapping it up" somewhat, and at least narrowing our range and reorienting our money toward excellent tubes that we _know_ will both sound good and couple well in our LD. It just seems like a so much better investment than before lol...
  
 And, yeah, for those who haven't treated themselves to a good 6922/E88CC or 7308/E188CC, I urge you to do so. I mean, _any_ Philips group premium 6DJ8 will take your amp to a different and better world...!
  


trolldragon said:


> Hey gibosi
> 
> Pricklely Peete in this thread has done some major mods to his amp improving the sound totally.
> 
> ...


 
  
 So, hypothetically, would adding another filament "in series" with the the first one (i.e., a second tube) yield a similar drop in filament voltage, like in the example where a 6SL7 was swapped for a 6SN7 and voltage dropped?
  
 If so, I still think that just wastefully using two separate tubes may just better and prettier...
  


gibosi said:


> Maybe I should explain my thinking...  The Sylvania 5751 TMBP and the Tung-Sol JAN-CTL-6SU7GTY are very good tubes, among the best of their breed. But in my opinion, they are not as good as the 6922/E88CC and 7308/E188CC I have been listening to recently. Given that, on eBay the Sylvania and Tung-Sol have typically been going for around $50. On the other hand, I have paid in the neighborhood of $30 to $50 each for the eight 6922 and 7308 I have. So if one is willing to spend $50, I would absolutely recommend a nice 7308. But if the Sylvania and Tung-Sol can be gotten for $25 to $30 each, then by all means, grab them. Cheers.


 
  
 I have to agree that for $50 (or even more), all those Amperex or Philips 6922 and 7308 are a _steal_...To think I used to blow $20 on pairs of pentodes and oddball single triodes (was fun in its own right)...


----------



## TrollDragon

Hey AFB

Tube filaments in series would probably not be a good idea in the LD and I would advise not to do so. Heaters do not work like a normal resistor would.

A little reading on series filaments...
www.emissionlabs.com/html/guarantee/HEATER-MODULES/index-heater.htm


----------



## Audiofanboy

trolldragon said:


> Hey AFB
> 
> Tube filaments in series would probably not be a good idea in the LD and I would advise not to do so. Heaters do not work like a normal resistor would.
> 
> ...


 
  
 Sorry if I confused you, I didn't mean actually changing the heater circuitry lol; I got my wording mixed up.
  
 My question is just: should we expect a lower heater voltage when using two tubes instead of one (twice the heater current and load on the transformer)?


----------



## TrollDragon

audiofanboy said:


> Sorry if I confused you, I didn't mean actually changing the heater circuitry lol; I got my wording mixed up.
> 
> My question is just: should we expect a lower heater voltage when using two tubes instead of one (twice the heater current and load on the transformer)?


 
  
 I wouldn't expect the voltage to drop with two tubes instead of one as the transformer is designed to run two tubes. Whether there is 300mA draw on one socket or a 600mA draw across two sockets, it should be within spec. Now a 600mA draw across one socket I can't say since it is yet to be determined how the windings are configured.
  
 I don't have any Vector sockets so I can't measure the voltages, but that would be a good thing for someone with the Vector's to do. Measure the filament voltage of two tubes vs one and post it here.


----------



## gibosi

audiofanboy said:


> So, hypothetically, would adding another filament "in series" with the the first one (i.e., a second tube) yield a similar drop in filament voltage, like in the example where a 6SL7 was swapped for a 6SN7 and voltage dropped?
> 
> If so, I still think that just wastefully using two separate tubes may just better and prettier...


 
  
 In an attempt to test whether running two separate tubes would affect the heater voltage, I made sure their was no tube in the 9-pin socket, and then plugged in two 7-pin tubes, 6HM5, and measured the heater voltage on the Vectors. Both of them read 6.7 volts. Therefore, running two tubes, versus one, makes no difference.
  
 If you are thinking about actually rewiring the filament wiring inside the LD, well, that is a whole 'nother story....


----------



## Artsi

If one has problems with little dot giving too much voltage to filaments, then i suggest you buy something like this.

 8.4V 0.45A and no worries of over voltage. Just got this in my hands.


----------



## hypnos1

Final comments on Tesla E88CC (gold pins & grids) v TFK ECC88.
  
 Although it has been mentioned that the 6DJ8 family don't seem to need much burn-in, these Teslas have improved massively over time (in my system at least) - now 50+ hrs.. I never thought they would/could match the Telefunkens, let alone surpass them. The TFKs have _slightly_ more bass slam, but get beaten in the detail/3D soundstage/clarity/overall 'magic' arenas. Revisiting every piece of music I have been using for comparison over the past months does nothing to bring any doubt into the picture - just more joy...oh happy days!
  
 Despite fear of repeating myself to nauseating degree, I still believe that soldering the headphone cable direct to the board has proved to be one of the biggest improvements I have managed to achieve - and the cheapest!


----------



## mordy

Hi Artsi,
  
 How does this tube sound compared to the octals?


----------



## Artsi

mordy said:


> Hi Artsi,
> 
> How does this tube sound compared to the octals?


 
 Heating time is noticeably longer with 8FQ7. About sound is difficult to say anything bad. After some usage this tube could even be one of my favorites. Local seller of this tube and philips 6922 & 6DJ8 said that GE 8FQ7 does have compressed sound. This was NOS and it really sounded first like it compressed everything to mp3. But even after hour or two of usage it is not sounding mp3 anymore. Sound is very pleasing and i'm going to listen this tube way longer. I haven't heard any bad sounding tubes for a long time.


----------



## TrollDragon

Running filaments below recommended rating will shorten the life of a tubes faster than overvoltage will from what I read, and 2V is quite the drop.
  
 Another thing to remember with these big octals is even though a 6L6 has a running heater current of 900mA hot, it can draw up to 3A on a cold startup. So everytime you power up a tube that is close to maximum heater current, you are actually creating a severe load on the LD transformer for a short period of time...
  
 Just something to think about...


----------



## TrollDragon

I have quite a few tube books, manuals etc in PDF format on Dropbox, if you want any of them just PM for the link.
  


Spoiler: The Super Sekret List - Enter if you dare... :D 



American Substitutes for Foreign Types.doc
 Amperex 1958.pdf
 Amperite Ballasts.pdf
 ARRL - Amatur Radio Handbok (1941).pdf
 Basic Theory of Electron Tubes (Army 1952).pdf
 Brimar Tubes 196x (partial).pdf
 Burroghs Nixie Tube Catalog B_W.pdf
 Federal Telephone and Radio Corporation - Handbook of Tube Operation (82nd Ed. 1944).pdf
 Foreign Substitutes for American Types.doc
 GE Essential Characteristics.pdf
 GE Neon Lamps 1965.pdf
 Kenyon Amateur 1937.pdf
 Mcarthur - Electronics and Electron Tubes (1936).pdf
 Moyer - Radio Recieving and Television Tubes (1936).pdf
 Mullard Tubes 196x.pdf
 Peters - Theory of Thermonic Vacuum Tube Circuits (1927).pdf
 Philips 1943 GVDR.pdf
 Philips Part 4 1972.pdf
 Preisman - Graphical Constructions for Vacuum Tube Circuits (1943).pdf
 Pullen - Conductance Curve Design Manual (1958).pdf
 Radiotron Designers Handbook (1941).pdf
 Radiotron Designers Handbook (1953).pdf
 Raytheon Amateur 1938.pdf
 Raytheon Tubes 196x.pdf
 RCA 1940 Vacuum Tube Design.pdf
 RCA 1962 Electron Tube Design.pdf
 RCA Amateu 1934.pdf
 RCA Electron Tubes (1935-1941) vol1.pdf
 RCA Electron Tubes (1942-1948) vol2.pdf
 RCA Industrial and Communications Types 1960.pdf
 RCA Interchange 1960.pdf
 RCA Phototubes 1941.pdf
 RCA R-10 1933.pdf
 RCA Radio Designers Handbook 4th Ed 1952.pdf
 RCA RC-12 1934.pdf
 RCA RC-13 1937.pdf
 RCA RC-14 1940.pdf
 RCA RC-15 1947.pdf
 RCA RC-16 1950.pdf
 RCA RC-17 1954.pdf
 RCA RC-18 1956.pdf
 RCA RC-19 1959.pdf
 RCA RC-20 1960.pdf
 RCA RC-21 1961.pdf
 RCA RC-22 1963.pdf
 RCA RC-23 1964.pdf
 RCA RC-24 1965.pdf
 RCA RC-25 1967.pdf
 RCA RC-26 1968.pdf
 RCA RC-30 1975.pdf
 RCA RefBook 1956.pdf
 RCA ST-59 Beam Power Tubes 1938.pdf
 RCA TT-3 1938.pdf
 RCA TT-4 1956.pdf
 Reich - Theory and Applications of Electron Tubes (1944).pdf
 Reich Principles of Electron Tubes (1941).pdf
 Rider - Inside the Vacuum Tube (1945).pdf
 Robin & Lipman 1947 Practical Amplifier Diagrams.pdf
 Schure Vacuum Tube Rectifiers (1958).pdf
 Secondary_Electron_Emission.pdf
 Seely - Electron Tube Circuits (1950).pdf
 Spangenberg- Vacuum Tubes (1948).pdf
 STC 1947 Standard Valves.pdf
 Sylvania 1951.pdf
 Sylvania 1959.pdf
 Taylor 1939.pdf
 taylor tube catalog.pdf
 taylor_transmitting 193xtubes.pdf
 Telefunken 1930-31.pdf
 The Thermonic Vacuum Tube and it's Applications (1920).pdf
 Theory of Thermonic Vacuum Tubes (Chaffee 1933).pdf
 Tomer 1960 Getting the Most Out of Vacuum Tubes.pdf
 Tube Numbering Systems.doc
 Vacuum Tube Oscilators (1953).pdf
 Western Electric Tubes 1933.pdf
 Western Electric Tubes 1956.pdf


----------



## gibosi

hypnos1 said:


> Final comments on Tesla E88CC (gold pins & grids) v TFK ECC88.
> 
> Although it has been mentioned that the 6DJ8 family don't seem to need much burn-in, these Teslas have improved massively over time (in my system at least) - now 50+ hrs.. I never thought they would/could match the Telefunkens, let alone surpass them. The TFKs have _slightly_ more bass slam, but get beaten in the detail/3D soundstage/clarity/overall 'magic' arenas. Revisiting every piece of music I have been using for comparison over the past months does nothing to bring any doubt into the picture - just more joy...oh happy days!


 
  
 I have three of these gold pin/grid Tesla E88CC, but I forgot to mark the one that has already been burned in for 20 hours!!  (>_<)  I guess I am going to have to start all over again! lol 
  
 And thank you so much for posting this! My wallet is feeling much better now that I am no longer feeling the urge to get a TFK ECC88!


----------



## ArmAndHammer

I haven't read this thread for quite some time...could someone point me in the right direction? I'm looking for a suitable replacement for my Sylvania GB-408A tubes that I love, LOve, LOVED in my LD1+. I've pretty much worn them out though, time for new tubes. Actually, I fried my amp as well so time for a new amp too...lol
  
Anyways, looking for something that might be easier to come by that can compare to the Sylvania GB-408A's.


----------



## mordy

Would like to measure the voltages using the Vectors. My wall outlet voltage is 122V. Does this mean that the values will be skewed upwards?
  
 If I were to measure the voltages of a dual triode octal tube, am I to measure only on one Vector adapter? Which pins to measure on the 12AX7 adapter that I use with an additional adapter for octal tubes?


----------



## gibosi

mordy said:


> Would like to measure the voltages using the Vectors. My wall outlet voltage is 122V. Does this mean that the values will be skewed upwards?
> 
> If I were to measure the voltages of a dual triode octal tube, am I to measure only on one Vector adapter? Which pins to measure on the 12AX7 adapter that I use with an additional adapter for octal tubes?


 
  
 Since your wall voltage is 122, like mine, your heater voltage might be high, around 6.7, like mine. On the other hand, you have a LD III, whereas, I have an LD 1+, so different transformers....
  
 Again, I prefer to take all measurements on the Vectors. In this way, it doesn't matter whether you are running a 6DJ8, 12AX7 or 6SL7.
  
 To measure heater voltage, set meter to AC and measure across pins 3 and 4 on the Vector that is supplying the 9-pin adapter.
  
 To measure Plate voltage, set meter to DC and measure across pin 5 and ground on each Vector. So you would have two readings, for the right triode and for the left.
  
 To measure Grid voltage, set meter to DC and measure across pin 2 and ground on each Vector. Again, two readings, one for each triode.
  
 Substitute your tube, amp and readings, and post like so:
  
 A 1960 Heerlen, Holland E188CC running in an LD 1+:
  
 Heater  -  6.7v

 Plate (R) - 81.5    Grid (R) - 3.1
 Plate (L)  - 81.5    Grid (L)  - 3.1


----------



## gibosi

A small package arrived today with a 1961 Philips Miniwatt 6922/E88CC (7L6 Delta1K3). I am curious to see how it compares with a 1960 7308/E188CC from the same factory....


----------



## Audiofanboy

gibosi said:


> A small package arrived today with a 1961 Philips Miniwatt 6922/E88CC (7L6 Delta1K3). I am curious to see how it compares with a 1960 7308/E188CC from the same factory....


 
  
 By all means, don't hesitate to write a long review of this tube, especially compared to the E188CC - which also deserves a full review of its own! I only have 15 hours on my E188CC, but I expect I'll be able to give pretty decent impressions by the end of the weekend.
  
 It's interesting how in 1961, the Heerlen factory was already on its 7th batch (change code) of E88CC, but only on its 3rd batch of E188CC. The fact that it took Philips those first batches or revisions of the premium E88CC, and four whole years, to come up with the even more premium and low noise E188CC does make me think that there just _has_ to be a difference between how the two types sound, at least for the early batches.
  
 I mean, I just can't imagine that it would have taken the company this long to just make an new-yet-inferior tube grade, especially considering the demand for low noise double triodes for communication/long distance transmission and other critical applications in those days. A good - as in from a good manufacturer - E188CC _should _be "better" than an equivalent E88CC made in the same time frame in the same factory. Maybe less musical, fun or whatnot, but logically less noisy, letting details stand out better in a blacker background; in theory of course.
  
 Even after a few hours, I could tell my early E188CC tube had a level of detail in the treble and mids that just screamed realism, probably moreso than my early Amperex US 6922, and I'm pretty that's because of the black noiseless background (bass still needs a bit of burn-in to assess its quality).
  
 There must have been a true _need_ for a low noise version of those tubes, since before - and even after - the E188CC was made, many companies were asking for special quality E88CC types for their own use and made to their own specs, like the CCa type in Germany. Interestingly, companies like the German Post kept buying and using the CCa type, forever based on the noisier E88CC, when most other European companies that used special quality E88CC tubes switched to E188CC when they could - or so I've read.
  
 My pair of Philips E188CC actually has some faded "E.D.F." ink stamps on the box, which was - and is still is - the French Electric company, meaning that they were already using the E188CC in some applications less than a year after the first batch.


----------



## hypnos1

gibosi said:


> I have three of these gold pin/grid Tesla E88CC, but I forgot to mark the one that has already been burned in for 20 hours!!  (>_<)  I guess I am going to have to start all over again! lol
> 
> And thank you so much for posting this! My wallet is feeling much better now that I am no longer feeling the urge to get a TFK ECC88!


 
  
 Oh dear, G, where do you find the time to carry out all these different tube-testings? You definitely have a different clock to mine, that's all I can say!..Good luck, anyway...
  
 Just one thing I must point out about these Tesla E88CCs - they are definitely NOT 'warm' tubes! So an already bright system would probably not be a good candidate for these otherwise marvellous babies...
  
 Slightly off-topic, but after posting a comment on a review of the HD650 methinks I opened up a can of worms - viz a comment from someone stating 'not to waste time and money on the Little Dot', but go for a Bottlehead Crack instead. Obviously I had to investigate and found what _might_ be an interesting project for the winter months (although I can't help feeling somewhat of a traitor!) - ie a self-build amp that looks amazingly good for the money, and would be fascinating to compare with the beloved MKIV SE now it has reached such heights. However, being a Stateside concern would mean high shipping and dreaded VAT robbery...so it's probably a non-starter. Has anyone here come across this supposed beauty? (Not in the looks department though, as far as I'm concerned - power, signal inputs and headphone socket on the TOP of the unit? Crazy, man! Mind you, it wouldn't take too much modifying to remedy that nonsense I'm sure...Plus I could use the pure silver wire that I have found does wonders wherever it goes...this time MY wallet is shaking with dread - perhaps VAT will be my saviour!!...


----------



## Audiofanboy

hypnos1 said:


> Oh dear, G, where do you find the time to carry out all these different tube-testings? You definitely have a different clock to mine, that's all I can say!..Good luck, anyway...
> 
> Just one thing I must point out about these Tesla E88CCs - they are definitely NOT 'warm' tubes! So an already bright system would probably not be a good candidate for these otherwise marvellous babies...
> 
> Slightly off-topic, but after posting a comment on a review of the HD650 methinks I opened up a can of worms - viz a comment from someone stating 'not to waste time and money on the Little Dot', but go for a Bottlehead Crack instead. Obviously I had to investigate and found what _might_ be an interesting project for the winter months (although I can't help feeling somewhat of a traitor!) - ie a self-build amp that looks amazingly good for the money, and would be fascinating to compare with the beloved MKIV SE now it has reached such heights. However, being a Stateside concern would mean high shipping and dreaded VAT robbery...so it's probably a non-starter. Has anyone here come across this supposed beauty? (Not in the looks department though, as far as I'm concerned - power, signal inputs and headphone socket on the TOP of the unit? Crazy, man! Mind you, it wouldn't take too much modifying to remedy that nonsense I'm sure...


 
  
 I was very curious about the Crack back when I had a HD650, but looking at the performance I'm getting now with the 6N30P-DR + premium 6DJ8 tubes on my MK IV SE, I have to wonder if a well tubed Crack would be better or just different.
  
 Bear in mind it's quite different from the LDs; I believe the first stage is a cathode follower for instance feeding a different breed of power tube(s), and the whole amp really only works well with high impedance headphones. So no mucking around with a second pair of lower impedance headphones without keeping a different amp.
  
 Basically, the Crack is fun to build, fairly powerful with high-Z cans, excellent sounding with good tubes, even moreso with the Speedball CCS upgrade, but not particularly versatile, and not particularly cheap once you factor everything in (parts, CCS upgrade, good tubes, factory build fee for the less DIY inclined). I keep seeing very good deals for Crack units in the classifieds here though.
  
 The LD MK III & IV are fairly powerful with high-Z cans (less so than the Crack), excellent sounding with good tubes (though using the best driver tubes is still a bit of a mess lol), pretty versatile all in all (more than you would think at first glance, as it actually works pretty well with low-Z cans), and "dirt cheap" to "not to bad of a deal" depending on which amp you buy, tubes used, etc...
  
 I would have no more use for the Crack with my orthos, so I'll probably never compare it to my MK IV, but was always curious about that in my Senn days. I do recall reading that the LDs really did hold their ground compared to the Crack though. I guess it's just a matter of tubes after that...


----------



## gibosi

hypnos1 said:


> Slightly off-topic, but after posting a comment on a review of the HD650 methinks I opened up a can of worms - viz a comment from someone stating 'not to waste time and money on the Little Dot', but go for a Bottlehead Crack instead. Obviously I had to investigate and found what _might_ be an interesting project for the winter months (although I can't help feeling somewhat of a traitor!) - ie a self-build amp that looks amazingly good for the money, and would be fascinating to compare with the beloved MKIV SE now it has reached such heights. However, being a Stateside concern would mean high shipping and dreaded VAT robbery...so it's probably a non-starter. Has anyone here come across this supposed beauty? (Not in the looks department though, as far as I'm concerned - power, signal inputs and headphone socket on the TOP of the unit? Crazy, man! Mind you, it wouldn't take too much modifying to remedy that nonsense I'm sure...Plus I could use the pure silver wire that I have found does wonders wherever it goes...this time MY wallet is shaking with dread - perhaps VAT will be my saviour!!...


 
  
 I bumped into a Bottlehead Crack at a recent meetup and noticed that it was running a 12AU7. I offered to loan the owner my three 5751s to try out, but he told me that the 12AX7, and even the 5751, had way too much gain, and wouldn't work. So... if you were to purchase and build one of these amps, tube rolling options would seem to be very limited. Given that, I will take my LD with 6DJ8, 12AX7, 6SL7 and 2C51 every time.


----------



## mordy

Hi Gibosi,
  
 Here are the measurements of a National Union double triode 6SL7GT from the 40-50's running in a LD MKIII through a 12AX7 adapter: (Measured with an inexpensive Sears digital multi tester)
  
 Voltage 122.8
  
 Heater 6.3 V
  
 Plate R 148 V
 Plate L  152 V
  
 Grid R 1.34 V
 Grid L  1.26 V
  
 Would like to hear comments what these measurements mean, especially if they have an effect on the longevity of the tube and the amp, if at all.
  
 The tube sounds very nice, and I have run it several days straight in the amp. The amp does not get hot or even warm at all; the tube feels slightly warm to the touch, but you can touch it without any discomfort.


----------



## gibosi

mordy said:


> Here are the measurements of a National Union double triode 6SL7GT from the 40-50's running in a LD MKIII through a 12AX7 adapter: (Measured with an inexpensive Sears digital multi tester)
> 
> Voltage 122.8
> 
> ...


 
  
 I will have to leave it to others to comment on what these measurements actually "mean". But what I find interesting is that with the same mains voltage, 122.8, the LD III provides 6.3 volts to the heaters, while my LD 1+ provides 6.7 volts!


----------



## MIKELAP

hypnos1 said:


> Oh dear, G, where do you find the time to carry out all these different tube-testings? You definitely have a different clock to mine, that's all I can say!..Good luck, anyway...
> 
> Just one thing I must point out about these Tesla E88CCs - they are definitely NOT 'warm' tubes! So an already bright system would probably not be a good candidate for these otherwise marvellous babies...
> 
> Slightly off-topic, but after posting a comment on a review of the HD650 methinks I opened up a can of worms - viz a comment from someone stating 'not to waste time and money on the Little Dot', but go for a Bottlehead Crack instead. Obviously I had to investigate and found what _might_ be an interesting project for the winter months (although I can't help feeling somewhat of a traitor!) - ie a self-build amp that looks amazingly good for the money, and would be fascinating to compare with the beloved MKIV SE now it has reached such heights. However, being a Stateside concern would mean high shipping and dreaded VAT robbery...so it's probably a non-starter. Has anyone here come across this supposed beauty? (Not in the looks department though, as far as I'm concerned - power, signal inputs and headphone socket on the TOP of the unit? Crazy, man! Mind you, it wouldn't take too much modifying to remedy that nonsense I'm sure...Plus I could use the pure silver wire that I have found does wonders wherever it goes...this time MY wallet is shaking with dread - perhaps VAT will be my saviour!!...


 
http://www.canuckaudiomart.com/details/649095164-bottlehead_crack_otl_amp_kit_w_speedball_upon_arrival_accepts_btc/


----------



## TrollDragon

mikelap said:


> http://www.canuckaudiomart.com/details/649095164-bottlehead_crack_otl_amp_kit_w_speedball_upon_arrival_accepts_btc/


 
 Nice!
 The guy even accepts BitCoin's... I wish I had been mining those a long time ago.


----------



## gibosi

hypnos1 said:


> Oh dear, G, where do you find the time to carry out all these different tube-testings? You definitely have a different clock to mine, that's all I can say!..Good luck, anyway...


 
  
 Oh, I wish I had a clock which could allow me to run in double time! lol  And to make things worse, it seems that these recent tubes are so good that when I sit down with the intention to do some critical listening, I often get so enthralled with what I am hearing that I stop listening to the "tube" and just "surrender" to the music. So while I do hope to be able to eventually test and review all these wonderful tubes, my progress is appallingly slow...
  
 So while revisiting the Tesla E88CC is definitely on my To-Do list, I have no idea when I will actually get to it... 
  
 And soon I will have a Western Electric 396A to add to the mix!!
  
 Too many wonderful tubes!! What a nice problem to have! lol


----------



## TrollDragon

That is in fact a terrible dilemma to have gibosi!
  
 You know that if you are ever overwhelmed by all the tubes you need to check, feel free to fire some of them this way and I can listen to them for you.


----------



## gibosi

To those that understand the significance of relative plate and grid voltage values: 
  
 I have three 1975 Voskhods, so I thought it might be interesting to measure them, and perhaps, these measurements could help me choose the one that has the best-matched triodes.
  
 Voskhod #1
  
 Plate (R)   85.3    Grid (R)   2.7
 Plate (L)   85.6    Grid (L)   2.9
  
 Voskhod #2
  
 Plate (R)   88.9    Grid (R)   2.6
 Plate (L)   88.9    Grid (L)   2.4
  
 Voskhod #3
  
 Plate (R)   85.2    Grid (R)   2.9
 Plate (L)   85.2    Grid (L)   2.2
  
 Number 2 seems to be the "best", but perhaps the differences in the others are too small to be significant?


----------



## Nic Rhodes

The Crack is never designed to be a tube rollers amp, The LD 3 and 4s are. The choice of sticking with a 12AU7 for the Crack is the right call. It is  what is designed to work with and VERY well with speedball (rolling is just poor here, just look at Doc posts). The LD is a fun amp that we can have fun to roll all sorts of cheap tubes in. This recent move to the ' more normal tubes' of other amps use routinely is rather missing the essence of the LD inho. I have shed loads of 5751s, '88s' etc but I also have other amps that use these tubes very much better. The '88' ain't a bad roll with difficulty but just because you can roll a tube doesn't make it a good operating point for the tube in the LD and there are far too many other tubes being talked about now that are just way off the mark (12AX7s?!)....For me the essence of the LD was the tube rolling for all, we are now moving into area where it is an area of just 6 (of us). Have we lost what was fun for these LD?


----------



## TrollDragon

+1 to that and well put.

Chasing down $5 Heptodes was a lot of fun. Seeking out a single tube less than $50 has taken a little of the sparkle out of it all.

But do "Roll On" by all means!


----------



## Artsi

nic rhodes said:


> The Crack is never designed to be a tube rollers amp, The LD 3 and 4s are.


 
  
 I'm getting so sad, i need to stop rolling with my LD 2 and get back to original chinese 6N6 6J1 tubes combination?


----------



## MIKELAP

trolldragon said:


> +1 to that and well put.
> 
> Chasing down $5 Heptodes was a lot of fun. Seeking out a single tube less than $50 has taken a little of the sparkle out of it all.
> 
> But do "Roll On" by all means!


 
 What do they say about idle hands........!


----------



## Nic Rhodes

why not roll E182CCs in the 3 and 4? or a 5687, still very affordable and mega tubes. Granted 6900 are probably out  What happened to the great 6J1p EV for 50cents US from the early 70s?


----------



## gibosi

nic rhodes said:


> why not roll E182CCs in the 3 and 4? or a 5687, still very affordable and mega tubes. Granted 6900 are probably out


 
  
 Apparently, these tubes require more current than the LD can provide. To the best of our knowledge, we are limited to .5amps.
  
 The E182CC, .64amps in 6 volt mode. The 5687, .9amps. And the 6900, 1.0 amps.


----------



## Nic Rhodes

what is the filament current of the 6h30 pi again?


----------



## hypnos1

Phew guys...didn't expect so much response to my humble post - but thanks to everyone. Looks like I (and my wallet) have been saved from possible anguish...what shall I do NOW all Winter - venture into octal land? Or take heed of Nic's penetrating comments and retreat gracefully?
 Such a dilemma...Actually, after seeing the sheer magical beauty of 'Yamamoto' tube amps ($4,000 +), had thought of taking up bank robbery. But 'she who must be obeyed' talked me out of it - spoilsport! So it looks like I might still be around to see what happens here, back in down-to-earth land (one can dream/drool, can't one? Having found this thread has a lot to answer for!!...).
  
 Cheers guys.


----------



## gibosi

nic rhodes said:


> what is the filament current of the 6h30 pi again?


 
  
 It is .9amps.
  
 Did you mean the E182CC to be used as a driver tube? or a power tube?


----------



## Nic Rhodes

power tube obviously, it is the stock tube of the 4se (? I bought my amp without). There is a current facination with just the pre tube when all the other roller tubes amps look far further a field with significant emphasis on the power tube. Yes I do use these tubes as drivers elsewhere (Zikkra 600se has all of 5687, E182CC and 5751 as the drivers on one amp) but the latter two are really the replacemenets for the 6N6 family (which is why they are used to drive a PSE 300bs in the the Zikkra). The mega tube for pennies was where much of the inspiration of this thread started with all the slightly oddball high end tubes for pennies like EH90, EH900, EK90 etc, we all know CV2493 and CCas are mega but with mega prices and need DIY (as opposed to simple adapter).


----------



## TrollDragon

The transformer in the MK IV provides the power tubes with 2.5 amps between them, or a buck and a quarter each.


----------



## gibosi

Amperex 6922 Faceoff
  
 I have a 1961 US-Amperex 6922 (VL6 Asterisk1B) and a 1961 Holland-Amperex 6922 (VL6 Delta1K3), same year and change code. Reviews comparing US-made Amperex and Holland-made Amperex almost always mention that the mid range on the Holland tubes is just a bit more forward. One of the reasons I purchased the Holland 6922 was to give me the opportunity to experience this difference, with all other things being equal. And in fact, as expected, this is the only difference I hear between these tubes.
  
 Which is best? I am beginning to think that any one tube at this level is seldom, if ever, "better" than the others. I think it really comes down to "ears and gear." Where on the mid range continuum does one feel the most comfortable. Both AFB and I found the mid range on the 1964 US-made Amperex 6922 to be a bit too lean and dry. But I am sure there are others who would find the tonality of that tube to be perfect. The 1961 US-made Amperex is just a tad bit warmer, and the 1961 Holland-made Amperex is a bit warmer still. I think I prefer the US-made Holland, but very frankly, both of these tubes can easily take me to cloud nine.


----------



## Audiofanboy

gibosi said:


> Amperex 6922 Faceoff
> 
> I have a 1961 US-Amperex 6922 (VL6 Asterisk1B) and a 1961 Holland-Amperex 6922 (VL6 Delta1K3), same year and change code. Reviews comparing US-made Amperex and Holland-made Amperex almost always mention that the mid range on the Holland tubes is just a bit more forward. One of the reasons I purchased the Holland 6922 was to give me the opportunity to experience this difference, with all other things being equal. And in fact, as expected, this is the only difference I hear between these tubes.
> 
> Which is best? I am beginning to think that any one tube at this level is seldom, if ever, "better" than the others. I think it really comes down to "ears and gear." Where on the mid range continuum does one feel the most comfortable. Both AFB and I found the mid range on the 1964 US-made Amperex 6922 to be a bit too lean and dry. But I am sure there are others who would find the tonality of that tube to be perfect. The 1961 US-made Amperex is just a tad bit warmer, and the 1961 Holland-made Amperex is a bit warmer still. I think I prefer the US-made Holland, but very frankly, both of these tubes can easily take me to cloud nine.




Nice comparison, gibosi!

I managed to spend a little quality time with my Philips E188CC (VR2 delta, 1960), and even though I didn't directly AB it with the US 1962 Amperex 6922, I have started to understand what these tubes can do.

The midrange is where it's at, definitely. The Holland E188CC probably have the most glorious - for lack of a better word - midrange I've heard to date. Read Joe's tube lore and many people take on the famous and elusive "pinched waist" Holland or US made tubes from the late 50's, yeah, the midrange sounds exactly like they write: liquid, lush, palpable and ultra musical.

But for now, approaching the 20 hour mark on the E188CC, I keep going from one extreme feeling to another. On some songs and watching videos, this is the best yet: immersive, absolutely quiet, and pure holographic sound with a glorious midrange. But on other songs, I'm just not finding the fun I'd gotten used to with the US 6922: the bass isn't as punchy - for now - and the treble (not high midrange, but high frequencies) is tamer and almost too musical - soft and clean - for my tastes.

So I'm a little puzzled now lol... At the same time I haven't felt the need to put the US 6922 back in, and I am listening to liquid glory through my headphones, but I'm also missing a little fun and punch... Musical paradise vs a meaner punch that draws you in faster.

Looking forward to your comparative take on the E188CC vs other premiums, gibosi! And yes, the Holland midrange and vocals are a bit more forward than the US versions.


----------



## Audiofanboy

Just found out I actually had a multimeter in my house, so I immediately processed to go and measure my LD!
  
 But what I discovered kind of scares me lol...
  
 My MK IV SE with a Philips E188CC Holland 1960
  
 Heater  -  5.82V

 Plate (R) - 75.2V    Grid (R) - 2.06V
 Plate (L)  - 75.2V    Grid (L)  - 2.09V
  
 And that's with a wall line - European - voltage of 222V, on a regular Saturday afternoon, as in, not a weekday in peek time.
  
 I have to admit that the heater voltage worries me a little... 5.8V is _way_ below specs. I could assume that the meter I'm using is crap, but the other measurements seem OK and consistent (those triodes are clearly well matched).
  
 I measured the heater with the AC setting and the other voltages with the DC setting as per recommendations. What happens if I measure the heater voltage in DC?
  
 I guess I'll try this again late at night, when _electricity is "better"_, you know...


----------



## gibosi

audiofanboy said:


> But for now, approaching the 20 hour mark on the E188CC, I keep going from one extreme feeling to another. On some songs and watching videos, this is the best yet: immersive, absolutely quiet, and pure holographic sound with a glorious midrange. But on other songs, I'm just not finding the fun I'd gotten used to with the US 6922: the bass isn't as punchy - for now - and *the treble (not high midrange, but high frequencies) is tamer and almost too musical - soft and clean -* for my tastes.
> 
> So I'm a little puzzled now lol... At the same time I haven't felt the need to put the US 6922 back in, and I am listening to liquid glory through my headphones, but I'm also missing a little fun and punch... Musical paradise vs a meaner punch that draws you in faster.


 
  
 The treble!  Yes, I heard this difference between the Holland and US 6922s, but didn't quite understand what it was that I was hearing... So yes, the mid range is more forward on the Holland tube, but the treble is a bit softer compared with the US tube. I noticed that metallic sounds, like cymbals, seem to be a bit sharper and more "real" on the US tube. This makes me even more curious about the Suresnes, France-made 6922, which (per Brent Jessee) has the Holland mid range with a bit more treble "punch" and detail.


----------



## gibosi

audiofanboy said:


> But what I discovered kind of scares me lol...
> 
> My MK IV SE with a Philips E188CC Holland 1960
> 
> ...


 
  
 That heater voltage does seem to be much too low.... If the heater voltage is too high, we can always add resistance to the circuit. But what does one do if the heater voltage is too low?


----------



## hypnos1

nic rhodes said:


> The Crack is never designed to be a tube rollers amp, The LD 3 and 4s are. The choice of sticking with a 12AU7 for the Crack is the right call. It is  what is designed to work with and VERY well with speedball (rolling is just poor here, just look at Doc posts). The LD is a fun amp that we can have fun to roll all sorts of cheap tubes in. This recent move to the ' more normal tubes' of other amps use routinely is rather missing the essence of the LD inho. I have shed loads of 5751s, '88s' etc but I also have other amps that use these tubes very much better. The '88' ain't a bad roll with difficulty but just because you can roll a tube doesn't make it a good operating point for the tube in the LD and there are far too many other tubes being talked about now that are just way off the mark (12AX7s?!)....For me the essence of the LD was the tube rolling for all, we are now moving into area where it is an area of just 6 (of us). Have we lost what was fun for these LD?


 

 Hi Nic.
  
 Whereas I can see where you are coming from, after a day pondering your words while further revisiting my various test albums (with ears and head now back on track after a bad cold, and hearing music like I've _never_ experienced before), I feel compelled to try and summarise what has been happening here for some time now - thanks to the dedication, patience, enquiring nature and willingness to share acquired knowledge (at great financial cost also) of a small group of wonderful guys.
  
 Basically, I believe the ethos has been not to 'stagnate' at a particular level, at a particular price point, but to keep moving forward and see just how much further the LDs can be coaxed from 'not bad for the money' to something that can compete rather more with much bigger boys - both tubed and SS. This surely is the goal for _anyone_ in _any_ area of "hi-fi".
 And this is precisely what has been achieved (and is continuing, but perhaps now much closer to the 'peak') in a relatively short period of time. As for myself, being a newbie to tube amps prior to finding this thread, I have gained MUCH in these past months and have been fortunate enough to share some of the delights and sense of achievement common, I am sure, to many others who have also been following this progress...there have been DEFINITE improvements over stock tubes, 6J1Ps etc. etc., often with the need for just minor mods.
  
 As for the recent forays into 9-pin land  -  and the need for rather more 'DIY' (yes, perhaps octals might prove a step too far for many), this surely has benefits for _most_ people who are so interested as to have discovered this particular thread viz - learning a bit more about what is going on with our equipment, and as a consequence the results that we are hearing. I would liken it in some ways (but FAR less punishing/dirty etc.) to having a go at some basic car maintenance/repairs. Learning, and seeing, what is actually going on in some vital areas of functioning can be not only interesting, but gives much greater insight into something that is otherwise taken for granted (in sometimes dangerous ignorance), and adds to the overall appreciation of just what we have! Not to mention the immense satisfaction that comes from the achievement of something that perhaps we may not have contemplated before (especially when it costs far less than in the hands of a commercial 'pro')... Mind you, the skills/effort required to enter the 9-pin game are certainly not in the same league as aforementioned car mechanics, I can assure you!!
  
 And so the upshot of my ramblings has to be that yes, what the 'pioneers' have been doing here _HAS _been of great interest and benefit to anyone wishing to reach further into 'audiophile' land, without actually having to spend TOO much money - especially if canny enough to let others do all the leg work/empty the wallet!!
  
 As I continue to revel in what is entering my eardrums, I KNOW there is a modicum of truth in what I have tried to put across...I repeat : this modest Little Wonder (MKIV SE) is another animal entirely to what I started off with, and have no regrets whatsoever in following every step that has been taken up to the present time. I am sure I am not alone in this, by any means...
  
 May the force continue...


----------



## Artsi

audiofanboy said:


> Just found out I actually had a multimeter in my house, so I immediately processed to go and measure my LD!
> 
> But what I discovered kind of scares me lol...
> 
> ...


 
 My guess is that you have bad multimeter. Battery could be too old? What i see is that all voltages are suspicious low. Try a new battery inside multimeter and does it give then better results.


----------



## Ctritical Bill

audiofanboy said:


> Just found out I actually had a multimeter in my house, so I immediately processed to go and measure my LD!
> 
> But what I discovered kind of scares me lol...
> 
> ...


 
  
 I would simply try another tube and see what you get for the heater voltage. That will give you something to compare with as it may be this one tube has much higher current demands than expected.
 The other voltages look pretty good for a 6DJ8 type.


----------



## Audiofanboy

hypnos1 said:


> As I continue to revel in what is entering my eardrums, I KNOW there is a modicum of truth in what I have tried to put across...I repeat : this modest Little Wonder (MKIV SE) is another animal entirely to what I started off with, and have no regrets whatsoever in following every step that has been taken up to the present time. I am sure I am not alone in this, by any means...
> 
> May the force continue...


 
  
 I couldn't have said it any better... I'm still amazed at how much progress has been made on this amp...
  


artsi said:


> My guess is that you have bad multimeter. Battery could be too old? What i see is that all voltages are suspicious low. Try a new battery inside multimeter and does it give then better results.


 
  
 That occurred to me, but all the other measurements seem OK, so...
  


ctritical bill said:


> I would simply try another tube and see what you get for the heater voltage. That will give you something to compare with as it may be this one tube has much higher current demands than expected.
> The other voltages look pretty good for a 6DJ8 type.


 
  
 I'll try another tube pretty soon, for now, I'm just trying to go all the way with this E188CC before doing anything else!
  
 Another measurement at midnight, local time, is giving me 218V on the wall, which is now fairly low, as it should really be closer to 230V; and a meager 5.62V on the heater, which, provided the multimeter works, really seems weird... I mean, if the heater voltage were a whole volt lower than specs, it would start to affect the sound somewhat, right?
  
 Edit: 5 minutes later, I'm measuring, 226V on the wall and 5.84V on the heater. While that's still not perfect, it's a little more consistent with the first measurement. The plate voltage and grid voltage are still 75.5V and 2.08V.


----------



## TrollDragon

audiofanboy said:


> I couldn't have said it any better... I'm still amazed at how much progress has been made on this amp...
> 
> 
> That occurred to me, but all the other measurements seem OK, so...
> ...


Looks like it is time to purchase a Power Conditioner... "Wallet Don't Fail Me Now"


----------



## mordy

Just got in a few new tubes. Based on Artsi's recommendation I got a Saratov factory Voskhod 6N9S octal tube from the 60's. Just measured it:
  
 Voltage: 121V
  
 Heater 6.2V
  
 Right plate: 151.2V   Left plate:  152.8V
  
 Right grid:   1.22 V    Left grid:    1.25V
  
 Initial impression: Sounds good and similar to the National Union but a more mellow mid range.


----------



## mordy

Hi Nic Rhodes and Hypnos1 and others,
  
 Read with interest the comments that the forum has moved into expensive tubes and more advanced modifications, leaving only a small group of people actively participating. IMHO there are many more people out there that follow the thread with great interest but don't post for whatever reason.
  
 Being far from knowledgeable in electronics, I have managed to more or less hang on and I have been able to try many of the new tube types that can be used in the LD amps. I find it very intimidating to put together adapters and read about high voltage dangers. But, there is no doubt that having heard tubes from the families of 6DJ8, 12AX7 and 6SL7 Octal tubes there is little that compels me going back to the old favorites.
  
 Now, about the comment of pricing ourselves out of the inexpensive tubes I do not agree. True, it gets harder to get bargains, but they are out there. Patience and communication with sellers will pay off. I have this self imposed limit of $8/tube (sometimes broken). I feel that one of the things we could do is to look for _good_ inexpensive alternatives to the 6922, 7308, E88CC, E188CC, 6SLGTY tubes etc etc.
  
 Here are some recent buys (all prices include shipping - sometimes you have to buy several tubes to get a better deal):
  
 Amperex 6DJ8 1975 A frame Tektronix certified: $5
  
 National Union 6SL7GT 1940-50: $8
  
 Saratov Voskhod 6N9S 60's: $3.25
  
 Voskhod 6N23P 1974: $3.25
  
 Thanks to Gibosi I have cobbled together breadboard adapters that don't use soldering (almost). I really enjoy the sound I get out of the LD MKIII and have tremendous listening pleasure even if I did not yet buy the real expensive tubes.
  

 The other day a single Telefunken E88C/6DJ8 1968 gold pin went for around $120. The bidding started on 99c and I thought that I had a chance LOL....


----------



## gibosi

"For me the essence of the LD was the tube rolling for all, we are now moving into area where it is an area of just 6 (of us). Have we lost what was fun for these LD?"
  
  
 Very frankly, I am not convinced that things are all that different now. Searching eBay for 6AK5, I see a large number of pairs going for as much as $50, and even as much as $89.  And since one double triode is the equivalent of a pair of LD compatible pentodes, then how can paying $50 to $89 for one double triode be considered all that different? 
  
 But of course, not everyone is willing to spend $50 for a pair of 6AK5s and by the same token, not everyone is willing to spend that amount for one double triode. And if one wants/needs to stay on a tight budget, it can be done. There are cheap deals to be had, both in the world of 6AK5s and the world of double triodes. No one has to spend $50 to get great sound.
  
 Now I admire Mordy tremendously for his discipline and success in extending his self-imposed limit of $8 a tube to double triodes, but I think a strong case can be made that one double triode should be counted as two tubes, and thus, a limit of $16 for a double triode is not unreasonable. And for $16 a tube, there are many very good double triodes to be had.
  
 So to my way of thinking nothing has really changed..... Except for the fact that the sound we are getting out of our LDs now is better than ever.


----------



## MIKELAP

gibosi said:


> "For me the essence of the LD was the tube rolling for all, we are now moving into area where it is an area of just 6 (of us). Have we lost what was fun for these LD?"
> 
> 
> Very frankly, I am not convinced that things are all that different now. Searching eBay for 6AK5, I see a large number of pairs going for as much as $50, and even as much as $89.  And since one double triode is the equivalent of a pair of LD compatible pentodes, then how can paying $50 to $89 for one double triode be considered all that different?
> ...


 
 +1


----------



## Audiofanboy

Hmm, some interesting points have been raised here.
  
 While, I agree that it may _look_ like only a handful of people are actively following up on each and every new trend - read tube type - I also believe that at least a few times more people are just lurking around here are still pretty much trying every new things that's brought up here. This is one of the rare threads I'm active on for example; but for two, maybe three threads I often post on, there's a lot more I always follow and never make myself know in - a.k.a. lurking.
  
 Anyway, price-wise, many of these premium, no - or barely any - compromise double triodes, especially the 6922/E88CC & 7308/E188CC, can be found without even looking that hard - basically camping 10 ebay listings for a week - and for very decent prices. Granted, not $8*2=$16, but you can easily get single European Philips E88CC or E188CC for $30-50, or a single Bugle Boy or whatnot - less premium - for $20-30.
  
 So, yeah, compared to where the thread started off from - people paying $35 for a pair of "matched" Voskhods from Yen Audio (scandalous in its own right) - I think we've definitely moved in the right direction. At least in terms of sound quality, even though price-wise we haven't ramped up that much all in all - if anything the heptode period was closer to being the exception in terms of price paid per tube!
  
 This being said, we've also come to a point where I highly doubt many new and improved whole tube families will pop up out of nowhere, so we can finally dissociate the "game" of tube rolling from the "end" of tube rolling, which is supposed to be getting the best sound out of one's amp. Nothing forbids people from going back to previous tube types and testing new ideas on them just for the heck of it; or finding more oddball tube types for fun, even knowing that it probably won't be to get them the best sound ever.
  
 Even I have a few ideas I never managed, or had time to, put together before "we, the people"; wait no... That's not right... "We, the handful" leaped in the double triode abyss. Here's a few ideas I had a few months ago, _cheap_ and interesting ideas :
  
 - Using a good ol' pentode - the examples I'd read about used a 6AU6 type - with the screen grid (g2) as the anode, and the actual anode grounded. I know this should work in theory, since it's used in some applications. People over on the LaFigaro 339 thread have used and loved this exact technique in their amp in the driver position, where a I-forget-which-pentode-type is triode strapped in this way. I never got a chance to try this on a LD before, since it used to be difficult to "invert" pins at the socket level, and since there was no place I knew of to easily tie a pin to the ground. Now, with the Vectors, virtually anything is possible, and we've confirmed that the front right screw is an easy path to the ground, so one could just link a wire between the anode pins to this screw and ground the anodes. Then, the screen grids could be rewired with the Vectors to their respective anode pins at the socket level. Just an idea... Should work so long as there's no more than 0.5W of dissipation on the screen grid; and even if there is, it'd still be interesting to try.
  
 - The 6GK5 tube: VHF single triode, _frame grid_ construction - like all the cool kids, and the 6DJ8, you know. This is the point where I'd stopped at just before using double triodes, so I never got a chance to try this tube type. It would need some degree of pins rewiring, but nothing out of this world if one tries hard enough. It's cheap, has pretty good characteristics, a frame grid, and is very linear. I have no idea how it is supposed to be biased since I don't recall we'd been talking about such things back a few months ago... Anyway, just an - cheap - idea.
  
 And on a totally separate note, two other recent ideas, or more like questions actually, that occurred to me yesterday when taking measurements of my amp.
  
 An easy one first, now that we know for sure that that front right screw leads to ground, couldn't we tie the pin 9 shield of 6DJ8 tubes to this screw instead of tying it to the right triode cathode?
  
 A more difficult question now : how hard would it be to make and use a battery-powered supply for the driver heaters (a 6.3V 0.5-1A DC power supply) and could it bring somekind of an improvement to the way the driver tubes function (less hum or noise, better and more stable current supply...)? I can't imagine it would be hard to make, I'm more curious about what it would change. I'm pretty sure I've read examples of people preferring a DC battery power supply to an AC transformer power supply for heating their tubes...
  
 Anyway, I'm sure there are many things we can still work on to improve the sound of our LD amps, without spending $100 a week on new tubes... And that's my point: no one _needs_ to spend that much on tubes if they're tube rolling for fun in the first place!


----------



## Audiofanboy

trolldragon said:


> Looks like it is time to purchase a Power Conditioner... "Wallet Don't Fail Me Now"


 
  
 Fortunately, Xmas is coming 
	

	
	
		
		

		
		
	


	




 !


----------



## gibosi

A bit off topic...
  
 I do not own a CD player and on the rare occasions that I want to play a CD, I just use the computer's built-in unit, which is not so good I am told. So I have been thinking about getting a simple CD player with optical out, but most of what I am seeing are jukebox and/or SACD players and are rather expensive. It occurs to me that I can pick up a Blu-ray player with optical out for not much money, and I also notice that these players typically support SACD, in addition to CD.
  
 Comments? Suggestions?
  
 Thanks!


----------



## mordy

Hi Gibosi,
  
 Oppo is a brand that has a very good reputation. This model appears to have an optical output but not Blue Ray:
  
 http://www.ebay.com/itm/Oppo-DV-981HD-DVD-Player-SACD-DVD-Audio-CD-PAL-DivX-1080p-upconversion-HDMI-/271339296646?pt=DVD_Players_Recorders&hash=item3f2d151786
  
 Expect to pay around $80 + shipping. You can go to the right column next to the listing and click on completed listings to see what people paid recently for this item.
  
 Some people in the Hi Fi world claim that the Sony Playstation 1 (earliest model) has excellent sound for CDs - could be found for $25 or less but no extra features.


----------



## mordy

More measurements:
  
 I bought a 1960s octal 6H9S, but I now see that the date is 0481. However, the seller included a second octal tube for free. It looks very much the same as the first one except for OTK1 printed on the base, otherwise there are no markings at all. Maybe this tube looks older, or it was just the dust on the base. When listening to this 6H9S tube it sounded better than the first one.
 The measurements are slightly different compared to the first one:
  
 122 V
  
 Heater 6.2V
  
 Plate R: 152.9V    Plate L:  154.6V
  
 Grid R: 1.18V       Grid L: 1.22V
  
 The next tube is an August 1974 Voskhod 6N23P tube (6DJ8 family):
  
 121.6V
  
 Heater 6.2V
  
 Plate R 102.8V        Plate L: 97.0V
  
 Grid R:  2.67V         Grid L:   2.76V   (Note: The plate and grid voltages fluctuate a little; the same as the AC house voltage.)
  
 First impression of the Voskhod 6N23P is that it is punchy and forward with good detail. Even though I bought is as used it could be that it needs more time to be comfortable in it's new home. Remember the 120 hr burn in of the old Voskhods?
  
 Wish I understood what the measurements indicate, and how to translate them into how something sounds. Based on my Hi Fi experience over a few years, measurements do not necessarily correspond to how something sounds.


----------



## TrollDragon

Ok here is something very strange... Is there a special setup for measurements?
  
 The JAN Sylvania 5751 from '79
  
 Line Voltage - 120VAC
 Filament  - 6.2 VAC
  
 Plate 1 - 145 VDC
 Grid 1 - 0 VDC
 Cathode 1 - 1 VDC
  
 Plate 2 - 144 VDC
 Grid 2 - 0 VDC
 Cathode 2 - 0.99 VDC
  
 All these are measured from ground except the filament?
 There is no measurable Grid voltage at all for some reason.


----------



## gibosi

trolldragon said:


> Ok here is something very strange... Is there a special setup for measurements?
> 
> All these are measured from ground except the filament?
> There is no measurable Grid voltage at all for some reason.


 
  
 According to Ctritical Bill, when the tube is idle, the grid is 0 volts, but measuring the cathode voltage when the tube is idle amounts to the same thing.
  
 http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/4200#post_10034489


----------



## mordy

Hi TD,
  
 Try measuring the grid voltage when playing something. Sometimes I had to switch the leads and use the other lead for ground.


----------



## TrollDragon

gibosi said:


> According to Ctritical Bill, when the tube is idle, the grid is 0 volts, but measuring the cathode voltage when the tube is idle amounts to the same thing.
> 
> http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/4200#post_10034489


Thanks gibosi!
I don't know how I missed that bit the first time around, that will teach me to skim posts. 



mordy said:


> Hi TD,
> 
> Try measuring the grid voltage when playing something. Sometimes I had to switch the leads and use the other lead for ground.


Thanks mordy!
I had tried that but thought no, as the volume of the music should have an impact on the voltage.

Then I heard a loud scratching noise in the beyer's on the table while I was using the probes and quickly unplugged them.

My old vintage part DIY B9A to octal adapter is not the easiest to get measurements from.


----------



## mordy

Hi TD,
  
 Measured grid voltage on my 6N23P tube on 0 volume, 1/2 volume and full volume (close to clipping) at the LDIII and could not find any significant differences. The voltage could be a fraction higher or lower (2.67v vs 2.69V). With this tube I cannot see any volume dependent changes in measured grid voltage.


----------



## TrollDragon

mordy said:


> Hi TD,
> 
> Measured grid voltage on my 6N23P tube on 0 volume, 1/2 volume and full volume (close to clipping) at the LDIII and could not find any significant differences. The voltage could be a fraction higher or lower (2.67v vs 2.69V). With this tube I cannot see any volume dependent changes in measured grid voltage.


 
 Excellent!
  
 Thanks mordy that is good to know.


----------



## Ctritical Bill

audiofanboy said:


> A more difficult question now : how hard would it be to make and use a battery-powered supply for the driver heaters (a 6.3V 0.5-1A DC power supply) and could it bring somekind of an improvement to the way the driver tubes function (less hum or noise, better and more stable current supply...)? I can't imagine it would be hard to make, I'm more curious about what it would change. I'm pretty sure I've read examples of people preferring a DC battery power supply to an AC transformer power supply for heating their tubes...


 
  
 This is something I am currently working on. I am thinking of using a wall adapter and a simple/cheap voltage regulator to bring it down to the required DC voltage. I can't see it making much difference to the sound but will get around the possible limitations of the LD transformer. Should be able to set up it up to run 12 volt tubes too.


----------



## gibosi

I picked up a 1 ohm 3 watt resister, put it in the heater circuit and now have a data-sheet perfect 6.3 volts! When I was talking to the old-timer who owns the electronics store, he pooh poohed the notion that 6.7 volts was too high. He told me that when 6.3 volt tubes were used in cars, the heater voltage was often as much as 8 volts and the tubes were fine. So.... maybe my tube isn't happier..... but I am happier.


----------



## TrollDragon

ctritical bill said:


> This is something I am currently working on. I am thinking of using a wall adapter and a simple/cheap voltage regulator to bring it down to the required DC voltage. I can't see it making much difference to the sound but will get around the possible limitations of the LD transformer. Should be able to set up it up to run 12 volt tubes too.


 
 Nice!
  
 I am looking into the "Wall Wart" idea as well with a LT1085 or LM338 type device as the regulator.
  
 This circuit here would be great, it automatically adjusts from 12AX7 to 6DJ8 by itself. 
	

	
	
		
		

		
			





 The article about the above is here at The Valve Wizard.


----------



## TrollDragon

gibosi said:


> I picked up a 1 ohm 3 watt resister, put it in the heater circuit and now have a data-sheet perfect 6.3 volts! When I was talking to the old-timer who owns the electronics store, he pooh poohed the notion that 6.7 volts was too high. He told me that when 6.3 volt tubes were used in cars, the heater voltage was often as much as 8 volts and the tubes were fine. So.... maybe my tube isn't happier..... but I am happier.


 
 Nice! You could probably run it at 7 volts for years but why take the chance when it is easy to make right.
  
 I just love the Old-Timer's and their logic, as back in the day the 6681, a mobile version of the 12AX7 designed to run by battery and designed to take a +/- 1.3V variation in the heater voltage could be bought brand spanking new from any corner drug store for $1.75... 
	

	
	
		
		

		
		
	


	



  
Old GE Tube Price Chart 1960


----------



## mordy

Adjusted for inflation, $1.75 in 1960 would be $13.71 today in Canada and $12.25 in the USA. Would you pay that much for a 12AX7 tube? I have been paying between $0.99 and $7.00.
  
 I guess I might pay that for an Amperex based on Gibosi's logic......LOL


----------



## TrollDragon

mordy said:


> Adjusted for inflation, $1.75 in 1960 would be $13.71 today in Canada and $12.25 in the USA. Would you pay that much for a 12AX7 tube? I have been paying between $0.99 and $7.00.
> 
> I guess I might pay that for an Amperex based on Gibosi's logic......LOL


 
 There always has to be one of you in the crowd... 
	

	
	
		
		

		
		
	


	




 
	

	
	
		
		

		
		
	


	



 Unfortunately wages didn't scale equally with the inflation... 
  
 I picked up my two JAN Sylvania 5751's for $10 locally with a pair of GE mystery 5751's thrown in for free...
 TubeDepot wants $30 for the exact same tube. http://www.tubedepot.com/nos-5751.html


----------



## kvtaco17

Man I've been following this thread for a while... And soon... Very soon I will actively be rolling tubes again... I have a ton of 6DJ8's and a few 12AX7's here... I just need the time to really sit down and listen/tinker... I'll be building an adapter to run these during my upcoming Christmas vacation... I feel like I have a ton of catching up to do...


----------



## gibosi

kvtaco17 said:


> Man I've been following this thread for a while... And soon... Very soon I will actively be rolling tubes again... I have a ton of 6DJ8's and a few 12AX7's here... I just need the time to really sit down and listen/tinker... I'll be building an adapter to run these during my upcoming Christmas vacation... I feel like I have a ton of catching up to do...


 
  
 And I think you now have a Lyr in the family?  If so, I for one, would be very interested in your impressions of your LD running a 6DJ8 compared to the Lyr. Cheers.


----------



## kvtaco17

gibosi said:


> And I think you now have a Lyr in the family?  If so, I for one, would be very interested in your impressions of your LD running a 6DJ8 compared to the Lyr. Cheers.


 

 I do! BUT I'd have to pry it away from my wife for an extended period of time lol


----------



## gibosi

kvtaco17 said:


> I do! BUT I'd have to pry it away from my wife for an extended period of time lol


 
  A little bribery... and a little trickery....  Perhaps you can find a way?  lol


----------



## kvtaco17

gibosi said:


> A little bribery... and a little trickery....  Perhaps you can find a way?  lol


 

 It won't be an issue lol She can used the o2 or little dot lol


----------



## Audiofanboy

gibosi said:


> And I think you now have a Lyr in the family?  If so, I for one, would be very interested in your impressions of your LD running a 6DJ8 compared to the Lyr. Cheers.


 
  
 A huge *+1* to this!
  
 --------------------------
  
 On a different note, about this external DC battery supply idea for the driver tube heaters, would anyone happen to have any suggestions as to what _type_ of batteries I could use to make something close to 6.3V (between 6 & 7 would be fine)?
  
 I actually have some experience in making battery powered supplies for some of my hi-fi gear, having made a DC supply for my USB-S/PDIF converter using 4 Ni-MH 1.2~1.25V batteries (so 5V USB basically; seems complicated but it is extremely simple and works _very_ well, seriously, dramatic improvement, and cheap too.
  
 But, I'm wondering what the easiest way to get ~6.3V would be - without regulators preferably, the least components, the better in my book... Two LiPoFe4 batteries? 3.3V*2=6.6V - unless the batteries are too full or too empty...
  
 Yeah, I know, it's crazy not to use regulators... But still, I tend to like quick, easy and highly efficient solutions above complicated and uncertain ones...


----------



## Kestovitutus

gibosi said:


> A bit off topic...
> 
> I do not own a CD player and on the rare occasions that I want to play a CD, I just use the computer's built-in unit, which is not so good I am told. So I have been thinking about getting a simple CD player with optical out, but most of what I am seeing are jukebox and/or SACD players and are rather expensive. It occurs to me that I can pick up a Blu-ray player with optical out for not much money, and I also notice that these players typically support SACD, in addition to CD.
> 
> ...


 
 Hi
  I don't have any SACD's, but I've noticed u can get good quality dvd players very cheap if u play only occasionally cd's. I run my used harman/kardon through my dac with imho good results.. Ended up paying a rubber band for it, before h/k I had pioneer dvd player which was something like 5 euros w/ shipping. Look for blu-ray/dvd-players with remote control... it helps a lot


----------



## kvtaco17

audiofanboy said:


> A huge *+1* to this!
> 
> --------------------------
> 
> ...


 
 I've already started on my 6DJ8 Lyr comparo... the Little Dot shootout is part 2 of this lol


----------



## gibosi

kestovitutus said:


> ...............I've noticed u can get good quality dvd players very cheap if u play only occasionally cd's. I run my used harman/kardon through my dac with imho good results.. Ended up paying a rubber band for it, before h/k I had pioneer dvd player which was something like 5 euros w/ shipping. Look for blu-ray/dvd-players with remote control... it helps a lot


 
  
 Thank you! 
  
 Yes, after looking into this for some time now, I have decided that an inexpensive Blu-Ray player feeding a digital signal to my DAC will be an excellent way to listen to an occasional CD in my system. I intend to get in touch with Santa Claus today or tomorrow...


----------



## Oskari

audiofanboy said:


> On a different note, about this external DC battery supply idea for the driver tube heaters, would anyone happen to have any suggestions as to what _type_ of batteries I could use to make something close to 6.3V (between 6 & 7 would be fine)?


 
  
 How about a 6-volt motorcycle sealed lead acid battery?


----------



## mordy

6V Motorcycle batteries have three cells with a nominal voltage of 2.1 V/cell = 6.3V, so this looks like an excellent suggestion. Rechargeable batteries are available for less than $10 on Ebay.
  
 However, the voltage fluctuates with the level of charge:
  
Motorcycle battery voltages 
Lead acid batteries 

 A typical lead-acid motorcycle battery

 The majority of classic motorcycle batteries are of the conventional lead acid variety. Whilst we think of these as being either 6 or 12v, this is a slight misnomer as the actual voltages are rarely these values if the battery is in good health.
 The primary battery voltage is dictated by the chemistry of the lead acid cell. Fully charged and in peak condition, each cell has a voltage across it’s terminals of 2.1v. Motorbike batteries are made up from a combination of such cells connected in series to give the required voltage.
 A ’6v’ battery is comprised of three cells giving a total voltage across it’s terminals of 3 x 2.1v = 6.3 volts. Likewise a ’12v’ battery is made up of six individual cells giving a total of 6 x 2.1v = 12.6 volts.
 These voltages are not however fixed and will vary both with the state of charge (or discharge) of the battery, and also depending upon the electrical load placed upon it. The more the battery is used and loses its charge, the lower it’s voltage gradually becomes. Similarly, when an electrical load is connected to the battery this also drags the voltage down.
  
State of charge It is therefore possible to determine the approximate state of charge of a motorcycles battery by measuring the voltage across it’s terminals. This is how ‘intelligent’ battery chargers work by constantly measuring the voltage and stopping charging once the desired level has been reached.
 The table below shows the approximate voltages that will be measured across the terminals of a lead acid cell for various states of charge. Also shown are the total voltages for 3 cell (6v) and 6 cell (12v) batteries as will be fitted to most classic motorcycles.
 Note that the voltages shown are open circuit voltages which means that there is no electrical load placed upon the battery. These readings are therefore taken with all lights etc turned off, and the engine not running.

*State of charge
 of battery**Per lead-acid
 battery cell
 (2.1v nominal)**6v nominal
 batteries
 (3x cell)**12v nominal
 batteries
 (6x cell)* Just charged*2.13v6.40v12.80v100%2.10v6.30v12.60v75%2.06v6.18v12.35v50%2.01v6.03v12.06v25%1.95v5.85v11.7vFully discharged1.75v5.25v10.5v
 
 * Initially after fully charging a battery, the battery voltage will be slightly higher and this will then settle down to the 100% fully charged value over the course of the next few hours.
  
 To me the question is if a tube sounds different with voltage fluctuations within a certain range. It may very well be that tubes are designed to perform well and last long within a certain heater voltage range. Maybe the real payoff with battery power is less hum and RF interference.


----------



## TrollDragon

Lead acid batteries also release gasses while charging, do you really want that in your house? Just look at the corrosive mung that collects on the posts... I don't think this would be a good idea, LiPo or GelCell maybe. One would still need some sort of regulation to keep the voltage constant and that would require a higher voltage battery. The regulators today will keep the output voltage precise with the source voltage right down to 1.25 above output.

I still think a 9V 3A wall wart type supply with a regulator would be the best bet for DC or just a 120V(220V)/12.6V CT transformer for AC.


----------



## Ctritical Bill

I have made up an external power supply for the heater filaments. Just an old wall adapter I had lying around and a little voltage regulator board. These little boards can be bought on ebay for less than $5. The output voltage can be adjusted with the trimpot which is the blue block with the tiny screw on top. I am using a 12v 500ma wall adapter but anything over about 9 volt DC and 500ma should work fine.
 Seems to work just fine. I adjusted the voltage with a multimeter and it is happily powering my 600ma 6SN7 octal.


----------



## gibosi

ctritical bill said:


> I have made up an external power supply for the heater filaments. Just an old wall adapter I had lying around and a little voltage regulator board. These little boards can be bought on ebay for less than $5. The output voltage can be adjusted with the trimpot which is the blue block with the tiny screw on top. I am using a 12v 500ma wall adapter but anything over about 9 volt DC and 500ma should work fine.
> Seems to work just fine. I adjusted the voltage with a multimeter and it is happily powering my 600ma 6SN7 octal.


 
  
 Cool!  And a question: If I want to run 12.6V tubes, will a 9 volt DC/500ma adapter work? That is, can the output voltage be adjusted higher than 9 volts? Or do I need something like a 15 volt adapter?


----------



## Oskari

mordy said:


> 6V Motorcycle batteries have three cells with a nominal voltage of 2.1 V/cell = 6.3V, so this looks like an excellent suggestion.


 

 That cell voltage is largely the reason why we have 6.3 and 12.6 volt tubes.
  


trolldragon said:


> Lead acid batteries also release gasses while charging, do you really want that in your house? Just look at the corrosive mung that collects on the posts... I don't think this would be a good idea, LiPo or GelCell maybe.


 
  
 I did say _sealed_, did I not? Gel or AGM batteries gently charged with an intelligent charger shouldn't be a problem, should they?


----------



## TrollDragon

oskari said:


> I did say _sealed_, did I not? Gel or AGM batteries gently charged with an intelligent charger shouldn't be a problem, should they?


 
 Yes indeed you did...
 My Bad.


----------



## mordy

Hi Ctritical Bill,
  
 Being unfamiliar with electronics, perhaps you could describe in more detail how to connect this regulated power supply? Could you take a wall wart of say 15V 1 A and connect it to the voltage regulator and then connect heater wires 3&4 (instead of putting these wires into the Vector adapter)?
  
 Would the voltage regulator described here do the job? Looks like it has a built in voltage display. Also, would it be possible to use a driver tube that draws a higher current than the LD amp provides, as long as the external A/C adapter has enough capacity?
  
 http://www.ebay.com/itm/New-LM317-Adjustable-Voltage-Regulator-Step-down-Power-Supply-Module-LED-Meter-/281168816716?pt=LH_DefaultDomain_0&hash=item4176f7aa4c


----------



## TrollDragon

"Shenzhen Willie's"​ Cheap Deals of the Day​ *if it doesn't burn your house down first*​  
  
 Note Cheap AC adapters out of China are really spooky and I would unplug them when not in use.
  
 24V 1A Wall Wart
 http://www.ebay.com/itm/AC-Converter-Adapter-DC-24V-1A-Power-Supply-Charger-US-plug-DC-5-5mm-1000mA-24W-/350833307159
  
 Adjustable step-down buck module
 http://www.ebay.com/itm/Adjustable-LM2596-DC-DC-4-75V-35V-to-1-25V-26V-step-down-buck-module-Regulator-/261345233407


----------



## TrollDragon

The 6H9C's have arrived from Romania.

  
 Also in the mail was a very nice gift from P.Q. 
	

	
	
		
		

		
		
	


	




  
 Here is the 6H9C mounted on the Little Dot MK IV.

 Listening to Paul Simon's Graceland 25th Anniversary Edition and for an inexpensive tube it actually sounds quite good.


----------



## Ctritical Bill

gibosi said:


> Cool!  And a question: If I want to run 12.6V tubes, will a 9 volt DC/500ma adapter work? That is, can the output voltage be adjusted higher than 9 volts? Or do I need something like a 15 volt adapter?


 
  
 For 12.6 volt tubes a 9v 500ma adapter would not be sufficient. There are 'step-up' voltage regulators similar to the one I have, that will output a higher voltage than the input but with reduced current. Remember Watts = Amps x Volts so as volts increase, current decreases and vice-versa. So for 12.6 volt tubes a 15v adapter would be best and 500ma should be okay.


----------



## Ctritical Bill

mordy said:


> Hi Ctritical Bill,
> 
> Being unfamiliar with electronics, perhaps you could describe in more detail how to connect this regulated power supply? Could you take a wall wart of say 15V 1 A and connect it to the voltage regulator and then connect heater wires 3&4 (instead of putting these wires into the Vector adapter)?
> 
> ...


 
  
 The answer to all your questions is ... Yes.
  
 The wall adapter and voltage regulator are used instead of the LD transformer. So connect the heater wires directly to the output of the voltage regulator. This way, the suspected power limitations of the LD transformer are avoided and you can use tubes with a higher current demand. Also, as the name implies, this is a voltage regulator so you can adjust it to supply exactly 6.3v regardless of your supply voltage and current demands of different tubes.


----------



## gibosi

For those of us who decide to use one of these wall adapter/voltage regulator devices to provide heater voltage, something to keep in mind.... We will need to remember to turn this circuit on when we turn the amp on and turn it off when we turn the amp off. After all, we don't want to be running the tube's heater filaments all the time.
  
 It might make sense to plug the wall wart into a power strip, or something similar, with an on/off switch, so we don't have to actually plug and unplug the adapter from the wall. And perhaps, we might want to consider plugging the amp and the heater circuit into the same power strip and and using the the power strip to turn both on and off at the same time....


----------



## mordy

Hi All,
  
 "You can use tubes with a higher current demand."
  
 Can anybody suggest inexpensive driver tubes that may work well with the higher current external power source for the heaters. The only thing that comes to mind is the 6SN7GT octal, but I remember seeing others being mentioned.


----------



## TrollDragon

Here is an interesting liitle circuit for powering tubes from batteries, it monitors the battery voltage level till critical then a relay opens and the plate power is killed to the tubes.
  
http://www.klausmobile.narod.ru/projects/pr_10_batt_e.htm


----------



## MIKELAP

If somebody is interested in a pair of Vector adaptors modified to accept 6DJ8 -6BQ7A tubes, adaptors will include a pair of Westinghouse 6BQ7A tubes already modified with about 40 hours on them .PM me If interested  $20.00+shipping  SOLD SOLD SOLD !!!!!!


----------



## gibosi

I received a Western Electric 396A/2C51 in the mail today, and I hope to get to it soon.... 
  

  
 FYI: There exists a 40 volt version of this tube, the 407A. Like the 12AX7, which can be configured to run on 6 volts, the 407A can be configured to run on 20 volts. As the only difference between the 407A and the 396A is the heater, I would expect them to sound very similar, if not identical, but unfortunately, I haven't been able to find much on Google about how they compare. Those who are running double triodes on their LD 1+ might want to try a 407A, as the LD1+ can be configured to drive 20 volt tubes. And those who are running double triodes on other LDs, a 24 volt wall adapter with a voltage regulator can be used to supply 20 volts to the heaters. Cheers.


----------



## gibosi

gibosi said:


> Amperex 6922 Face off
> 
> I have a 1961 US-Amperex 6922 (VL6 Asterisk1B) and a 1961 Holland-Amperex 6922 (VL6 Delta1K3), same year and change code.......


 
  
 To summarize the Amperex faceoff, I found the Holland tube to be more forward and lush than the US tube, but the highs were softer and more gentle. Next up, a 1967 La Radiotechnique 6922 (VL8 F7B1) manufactured in the Philips-owned Mazda factory in Suresnes, France. The La Radiotechnique reportedly (Brent Jessee) has a sweet lush mid range like the Holland tube, but better detail and high end punch, so I wanted to see how it compared with the US and Holland made Amperex tubes.
  
 La Radiotechnique vs Holland-Amperex
  
 As expected, these tubes are very similar, both having a sweet, lush mid range. And indeed, as Brent Jessee notes, the French tube does have a bit more high frequency detail and punch. However, I found this difference to be rather subtle. To my (rather old) ears, the difference is small enough that if someone has one of these tubes, I would recommend against getting the other. But then, my ears are old... lol
  
 So to be fair, it seemed reasonable that if someone (likely with younger ears than mine) found the high end of the Holland tube to be too soft, then perhaps the French tube might just be perfect. And with that in mind, I set up another face off to try to compare the high end detail of the French and US tubes.
  
 La Radiotechnique vs US-Amperex
  
 In listening to these two tubes, I felt that the treble was very comparable. However, I found that switching back and forth between the lush mid range of the French tube and the more laid-back and cooler mid range of the US tube to be rather jarring. But each time, after about 20 or 30 minutes, my brain settled down and both sounded great.
  
 Again, I think I could be happy with any of these three, and at this point in time, I am unable to choose a favorite. Perhaps after some weeks, or months, one will eventually rise to the top, but for now, the best I can do is to recommend all of them. The transparency and dynamics, the imaging and spaciousness - the realism is just breathtaking.
  
 Next, I will try to compare the 1961 Holland-Amperex 6922/E88CC to the 1960 Holland-Amperex 7308/E188CC. And then, finally, I hope to summarize my impressions of the 1975 Voskhod 6N23P....


----------



## mordy

Hi Gibosi,
  
 Thank you very much for your in depth analysis of the various Amperex type tubes. I have the same experience as you, namely that I get used to listening to a certain great tube and then find it unsettling to get used to another great sounding tube. With the best sounding tubes, _where nothing bothers you_, it becomes a matter of taste or preference, but my brain still needs time to adapt.
  
 That said, I have to get used to the Voskhod 1975 6N23P tubes I just got, in addition to Voskhod (Saratov) 6N9S octal tubes. The 6N23P tubes are detailed and punchy, and the Saratov tube has a very sweet spacious presentation that is very enjoyable.
  
 I ordered a bunch of 6DJ8 variants (6BC8, 6BZ7, 6BZ8,X155) in the hope of finding an inexpensive alternative to the big A. Time will tell...
  
 About getting higher current adapters: What is better to use for powering the heaters, a 15V 2A adapter, or an old laptop 20V 3.5A adapter? Will the laptop adapter fry a voltage regulator that is rated up to 40V and 2A?


----------



## gibosi

mordy said:


> That said, I have to get used to the Voskhod 1975 6N23P tubes I just got, in addition to Voskhod (Saratov) 6N9S octal tubes. The 6N23P tubes are detailed and punchy, and the Saratov tube has a very sweet spacious presentation that is very enjoyable.
> 
> About getting higher current adapters: What is better to use for powering the heaters, a 15V 2A adapter, or an old laptop 20V 3.5A adapter? Will the laptop adapter fry a voltage regulator that is rated up to 40V and 2A?


 
  
 What is the construction of your 1975 Voskhods? I have one with a wire getter post (left) and another with the getter supported by an extension of the shield (right). The first is a bit darker than the other, but both are fabulous. 
  

  
 Either of those adapters should be fine. It is my understanding that even though your laptop adapter can put out 3.5 amps. the tube will draw only what it needs, and therefore, for example, the voltage regulator should never see more than 600ma for a 6SN7


----------



## Audiofanboy

Heerlen VR2 E188CC vs New York 7L6 6922:
  
 OK, so I finally found the courage to swap the tubes to give a lil' more feedback.
  
 The US 6922 immediately sounds a little more extended; highs are more shimmering, bass has a kick/punch while extremely tactile. Mids used to sound close to perfect to me before trying the E188CC and still sound great to me even afterwards, just different I guess; mids on both tubes has body, but it is lusher on the E188CC and "just" musical on the 6922. Listening to the 6922 again, I think the soundstage is much larger, and probably deeper than with the E188CC; actually that might account, in part, for the impression of vocals being a bit more "forward" on the Heerlen tube.
  
 Now, as far as details and realism go, it's really difficult to pick a winner here... Details seem more emphasized on the 6922: they come at you in a bigger, meaner, way from the angles, where I could swear I could hear a little more mids and high mids details closer to the center of the picture with the E188CC.
  
 So, yeah, I guess the E188CC is more polite than the 6922: lusher but tamer mids, less glorious highs, less punchy bass, but probably a better sense of low level detail than with the 6922. You really get used to the bass impact and shimmering highs of the 6922, but at the same time, you immediately miss this sense of center imaging with more micro-detail and less extremes that the E188CC. The 6922 is macro-detail with body and impact, and the E188CC is micro-detail with intimacy and focus. I'm obviously overemphasizing the differences here though, as the tubes sound more similar than not, but you can definitely tell those are different in a few ways.
  
 It's terrifying how quickly you can get used to something better than before... Comparing both tubes, I could almost swear _something_ is missing now lol; a sense of absolute realism and detail in a way. Guess I just need to order _more_ tubes now... It never ends I tell you.
  
 Oh yeah, measurements: I measured voltages with the 6922. Wall was 228V.
  
 Heater  -  5.89V

 Plate (R) - 79.9V    Grid (R) - 2.04V
 Plate (L)  - 79.8V    Grid (L)  - 2.05V
  
 Where the last time I re-measured the E188CC (with 227V on the wall I think), I got:
  
 Heater  -  5.84V

 Plate (R) - 75.2V    Grid (R) - 2.06V
 Plate (L)  - 75.2V    Grid (L)  - 2.08V
  
 So, no huge difference here. The 35 mA lower current requirements of the 6922 might be responsible for the slightly higher heater voltage. The other values are pretty similar.
  
 Edit: The E188CC is back in, yeah that was quick I know... I guess an even better way to describe both tubes in only one word is: the *6922 is punchy*, whereas the *E188CC is liquid *- that's the word I was missing earlier. And listening again, the E188CC's highs are actually very detailed too, whereas the 6922's highs can almost sound a little sibilant on a bad day. Definitely a bit more microdetail in the midrange of the E188CC, but less bass too, which is a bit of a compromise (it's hard to forget to way the 6922 renders a bass kick, it's almost like air is actually blown towards you ear).


----------



## mordy

Hi Gibosi,
  
 I got four used Voskhod 6N23P tubes from Aug 1974, all with the wire getter. In your opinion, how does this tube compare to the Amperex  6922/7308/6DJ8?


----------



## gibosi

mordy said:


> I got four used Voskhod 6N23P tubes from Aug 1974, all with the wire getter. In your opinion, how does this tube compare to the Amperex  6922/7308/6DJ8?


 
  
 I have not listened to a 1974 Voskhod, so I can't say.... However, I have listened to 1975 and 1978 Voskhods, and in my opinion, they are every bit as good as the Amperex 6922. And while I haven't yet had time, an Amperex vs Voskhod face-off is definitely on my To Do list. But first, I want to take some time to consider the Heerlen E188CC.


----------



## kvtaco17

mordy said:


> Hi Gibosi,
> 
> I got four used Voskhod 6N23P tubes from Aug 1974, all with the wire getter. In your opinion, how does this tube compare to the Amperex  6922/7308/6DJ8?


 
  
  


gibosi said:


> I have not listened to a 1974 Voskhod, so I can't say.... However, I have listened to 1975 and 1978 Voskhods, and in my opinion, they are every bit as good as the Amperex 6922. And while I haven't yet had time, an Amperex vs Voskhod face-off is definitely on my To Do list. But first, I want to take some time to consider the Heerlen E188CC.


 

 I own a paid of 74 and 75 Voskhod as well as the Amperex 6922 and I'd say they are about equal... the earlier Voskhods are more musical then the 75, which is tilted towards the drier more analytical side, but not what I'd call dry or analytical lol SO 74 slightly warmer then 75... this is with my Lyr obviously...
  
 My parts for the single 6DJ8 to LD 1+ shipped today also... I should soon catch up to you guys!


----------



## gibosi

kvtaco17 said:


> I own a paid of 74 and 75 Voskhod as well as the Amperex 6922 and I'd say they are about equal... the earlier Voskhods are more musical then the 75, which is tilted towards the drier more analytical side, but not what I'd call dry or analytical lol SO 74 slightly warmer then 75... this is with my Lyr obviously...


 
  
 Do your 1975s have a wire getter support like the 1974? Or do they have the getter supported by an extension of the shield? And gray plates?


----------



## kvtaco17

gibosi said:


> Do your 1975s have a wire getter support like the 1974? Or do they have the getter supported by an extension of the shield? And gray plates?


 
 Let me dig them out!


----------



## kvtaco17

the have grey plates and halo-ish getter supported by a grey strip that comes from the plates below.


----------



## kvtaco17

gibosi said:


> What is the construction of your 1975 Voskhods? I have one with a wire getter post (left) and another with the getter supported by an extension of the shield (right). The first is a bit darker than the other, but both are fabulous.
> 
> 
> 
> Either of those adapters should be fine. It is my understanding that even though your laptop adapter can put out 3.5 amps. the tube will draw only what it needs, and therefore, for example, the voltage regulator should never see more than 600ma for a 6SN7


 
 like the one to the right...


----------



## TrollDragon

Ceramic octal plugs have arrived, now for the B9A's to get here for 12AX7 / 6DJ8 adapter building.


----------



## gibosi

This morning, I received an adapter to allow 2C51/396A/5670 tubes to be used in a 9-pin socket configured for 6DJ8, and I am pleased to report that it works perfectly. With this it will be much easier to roll and compare these tubes with the 6DJ8 types. As I write this I am listening to the Western Electric 396A and it sounds great. 
  
 http://www.ebay.com/itm/260723522614?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649
  
 And in the picture below you can also see the 1 Ohm 3 Watt resister I am using to reduce my heater voltage down from 6.7 volts to 6.3 volts. (Maybe we should have a contest to see who among us has the craziest and ugliest configuration? lol )


----------



## CollectoR13

Hello guys!
  
 I have a question:
 you know, back then when we had only limited tube possibilities discovered, EF91, EF92 and EF95 families, there were some kind of reference tubes like the Mullard EF 92, Voskhod 6ZH1P and so on....
 I now enjoy the sound of the Voskhod, but I wonder if there are any new tubes THAT REQUIRE NO MODDING, which sound better than these Voskhod's?
 Maybe someone has experience with these tubes and knows what would be a great ugrade?
  
 Thank you very much!
  
 (And yes, I know I am not up-to-date tube-wise here 
	

	
	
		
		

		
		
	


	




)


----------



## kvtaco17

collector13 said:


> Hello guys!
> 
> I have a question:
> you know, back then when we had only limited tube possibilities discovered, EF91, EF92 and EF95 families, there were some kind of reference tubes like the Mullard EF 92, Voskhod 6ZH1P and so on....
> ...


 
 6DT6, 6HM5... BOOM!  My personal favorites of yesterday! 6DT6's try to get RCA's or Sylvanias... the 6HM5 try to get the tall tubes not the short, squat ones... they shorties sound like poo...


----------



## gibosi

kvtaco17 said:


> 6DT6, 6HM5... BOOM!  My personal favorites of yesterday! 6DT6's try to get RCA's or Sylvanias... the 6HM5 try to get the tall tubes not the short, squat ones... they shorties sound like poo...


 
  
 6DT6 - use EF92 setting
 6HM5 - use EF95 setting


----------



## CollectoR13

Thank you for these recommendations!
  
 So these are kind of endgame tubes when I don't want to mod something?
 And do they improve over the Voskhods in every aspect?
  
 Should say that I like a crystal clear sound with great dynamics,good punch, maybe a hint of warmth.
 So the Voskhod's were great til now, but you know, upgrades are so tempting......


----------



## gibosi

collector13 said:


> Thank you for these recommendations!
> 
> So these are kind of endgame tubes when I don't want to mod something?
> And do they improve over the Voskhods in every aspect?
> ...


 
  
 You have to remember that everyone has different ears and different gear. So one person's best-ever tube is another's so-so tube. Generally, most who have heard these tubes felt they were better than any EF91, EF92 or EF95. Will you think they are? The only way to find out is to give them a try. And fortunately, they are cheap. So if you try them and still prefer your Voskhods, you haven't lost much. Happy tube rolling!


----------



## CollectoR13

gibosi said:


> You have to remember that everyone has different ears and different gear. So one person's best-ever tube is another's so-so tube. Generally, most who have heard these tubes felt they were better than any EF91, EF92 or EF95. Will you think they are? The only way to find out is to give them a try. And fortunately, they are cheap. So if you try them and still prefer your Voskhods, you haven't lost much. Happy tube rolling!



Thank you again. 
How would you describe both tubes tonality wise? 
I think I am trying one of them then.


----------



## itchyears

was considering this amp, now to read from post 1....
  
 Think ill call in sick for a week


----------



## Audiofanboy

itchyears said:


> was considering this amp, now to read from post 1....
> 
> Think ill call in sick for a week


 
  
 Lol, read it starting from the end of the thread, it'll be more useful to you (though pretty destabilizing at first!).


----------



## gibosi

collector13 said:


> Thank you again.
> How would you describe both tubes tonality wise?
> I think I am trying one of them then.


 
  
 Sorry, but I haven't listened to those tubes in a long time..... However, you can search this thread for more information:
  
 http://www.head-fi.org/newsearch?advanced=1&byuser=&containingthread%5B0%5D=563884&newer=1&output=posts&resultSortingPreference=relevance&sdate=0&search=6dt6&type=all
  
 http://www.head-fi.org/newsearch?advanced=1&byuser=&containingthread%5B0%5D=563884&newer=1&output=posts&resultSortingPreference=relevance&sdate=0&search=6hm5&type=all


----------



## MIKELAP

itchyears said:


> was considering this amp, now to read from post 1....
> 
> Think ill call in sick for a week


 
 The newer tubes start at around page 50 and they are enumerated on page 77 and as Audiofanboy stated for the best and more expensive tubes start reading from the end of the thread.


----------



## mordy

Hi CollectoR13,
  
 Buy these tubes from Yugoslavia; offer $4 or $5 each - free shipping. Asking price is $6.95. Look up on Ebay:
  
6HM5 /6HA5 / EC900 export quality audio triode tube / NOS / FREE SHIPPING /  
 As a bonus you will get a 1 second fireworks display when you turn on the tubes. (Don't worry, they are designed to flare up for quicker start, and it will not damage anything)


----------



## mordy

Hi All,
  
 Enjoying listening to an octal Sylvania 6SL7WGT tube, maybe from January 1952 or more likely 1962 (date code A2B). Not as super detailed as the 6DJ8 family, but very sweet and musical and non fatiguing.





  




 Since the 6SL7 is the American equivalent to the Russian 6H9S/6N9S tube, did I _partially_ upgrade the MKIII to the MK9 Little Dot amp?
  
 Here is the advertising for the MK9 (English needs improvement):
  

Little Dot MK9 is that uses a electronic tube as a headphone amplifier. It uses 3 tubes (before: 6N9P, after class: 6080*2) were used as two stereo left and right channel amplifier. The input signal is the audio signal from the CD player or decoder, an amplified output signal used to drive headphones. The machine also has a road as a RCA signal output by the first stage, supply other amplifier as before use.
MK9 uses tube amplification circuit in the electronic is relatively rare in the SEPP single ended push-pull, OCL no output capacitor direct coupled power amplifier circuit.
The circuit output dynamic than the cathode output generally large (undistorted swing: 30Vp-p), due to the cancellation of the output capacitance, low frequency response can dive deeper, more solid, soprano Alto can be more transparent.
But to make the circuit in the case of direct coupled DC level is zero, need symmetrical supply complex. In order to stabilize the operation of the circuit, and the machine also adopts a "zero servo tracking circuit".
In order to ensure the safety of the output load, relay protection circuit and output protection special chip. The machine output tube uses a new production of the United States of America RCA company 50 years Antique Tube (ONS), is one of the best sound similar tube in the world.
 

  
 (The 6080 RCA tubes are rated at 6.3V and 2.5 A and are plentiful on Ebay for $10 or less. )
  
 Is it possible to add the protective circuit so that I can use a DC coupled ss amp with the the MKIII? It would have to be an outboard plug in style chip since I am not capable of opening the amp and solder in a circuit.


----------



## Audiofanboy

> Originally Posted by *mordy* /img/forum/go_quote.gif
> 
> Is it possible to add the protective circuit so that I can use a DC coupled ss amp with the the MKIII? It would have to be an outboard plug in style chip since I am not capable of opening the amp and solder in a circuit.


 
  
 +1 to that question!
  
 Wouldn't just adding a large value coupling capacitor (?) on the output of each channel basically cancel any DC offset - and therefore offer a bit more protection and _de facto_ compatibility with non DC couple amps?


----------



## TrollDragon

audiofanboy said:


> +1 to that question!
> 
> Wouldn't just adding a large value coupling capacitor (?) on the output of each channel basically cancel any DC offset - and therefore offer a bit more protection and _de facto_ compatibility with non DC couple amps?


 

 I have a nice little box coming from AskewLabs with just such an arrangement configured. It will have RCA In/Out jacks with an A/B switch to compare the sonic differences with the protection circuit engaged or in pass through mode, as the circuit will minimally alter the sound out of the amp.
  
 This box will provide DC protection so anyone can safely connect the Little Dot's Line Out to an amplifier or receiver. When this box arrives I was planning on setting up a tour like they do with headphones, those interested could have the box mailed to them, try it out for a while and then mail it to the next guy on the list. After the trial if you feel it is something you want you can either build your own or order one all ready to plug and play.
  
 It won't be here until the new year and I will let everyone know when it arrives.


----------



## Audiofanboy

trolldragon said:


> I have a nice little box coming from AskewLabs with just such an arrangement configured. It will have RCA In/Out jacks with an A/B switch to compare the sonic differences with the protection circuit engaged or in pass through mode, as the circuit will minimally alter the sound out of the amp.
> 
> This box will provide DC protection so anyone can safely connect the Little Dot's Line Out to an amplifier or receiver. When this box arrives I was planning on setting up a tour like they do with headphones, those interested could have the box mailed to them, try it out for a while and then mail it to the next guy on the list. After the trial if you feel it is something you want you can either build your own or order one all ready to plug and play.
> 
> It won't be here until the new year and I will let everyone know when it arrives.


 
  
 Nice! So, wait, you're talking about what essentially a custom-made DC-offset cancelling box right? I'm curious as to how much such a contraption would cost to have made?
  
 What's actually _in _the box, btw? Am I totally wrong in thinking it's basically large caps lol, or do I at least have the basic idea down?


----------



## TrollDragon

audiofanboy said:


> Nice! So, wait, you're talking about what essentially a custom-made DC-offset cancelling box right? I'm curious as to how much such a contraption would cost to have made?
> 
> What's actually _in _the box, btw? Am I totally wrong in thinking it's basically large caps lol, or do I at least have the basic idea down?


 
 I'll have all the details when the box arrives and I doubt it will be too expensive.
  
 I don't know the exact circuit but I imagine it will have some nice quality caps of what value I don't exactly know, he has calculated the minimal effect on the output as much as possible while still providing protection.


----------



## Audiofanboy

trolldragon said:


> I'll have all the details when the box arrives and I doubt it will be too expensive.
> 
> I don't know the exact circuit but I imagine it will have some nice quality caps of what value I don't exactly know, he has calculated the minimal effect on the output as much as possible while still providing protection.


 
  
 Yeah, I always wondered if I could just solder some appropriate caps, like, directly on each output RCA cable going to the power amp(s), so any DC offset would just get cleaned up nicely. But every time I thought about actually trying it out, a blinking red light turned on in my head, and a voice too: "_Thou shalt not maim thine interconnects in vain!__ Especially if thine electrical knowledge is so limited!_". So, yeah, that stopped me from doing it lol; but I might consider it again depending on how your crazy contraption works - and how hard it is to make, I'll solder a cap or two but not a _box full of electronics_...


----------



## CollectoR13

mordy said:


> Hi CollectoR13,
> 
> Buy these tubes from Yugoslavia; offer $4 or $5 each - free shipping. Asking price is $6.95. Look up on Ebay:
> 
> ...




I would be able to get some made by sylvania for cheap. 
Are they good too or maybe better?


----------



## mojorisin35

Seriously I have tried them all, except for the supermod tubes (adapters etc..). The yugo 6Hm5 is by far the best for unmodded tubes in my gear. A close second are the Lorenz EBC91 however you need to cut some pins.I say get both and let us know which you think are the best.


----------



## MIKELAP

trolldragon said:


> I have a nice little box coming from AskewLabs with just such an arrangement configured. It will have RCA In/Out jacks with an A/B switch to compare the sonic differences with the protection circuit engaged or in pass through mode, as the circuit will minimally alter the sound out of the amp.
> 
> This box will provide DC protection so anyone can safely connect the Little Dot's Line Out to an amplifier or receiver. When this box arrives I was planning on setting up a tour like they do with headphones, those interested could have the box mailed to them, try it out for a while and then mail it to the next guy on the list. After the trial if you feel it is something you want you can either build your own or order one all ready to plug and play.
> 
> It won't be here until the new year and I will let everyone know when it arrives.


 
 That would be  great i could now use the Littledot as preamp with my Pioneer SX 750 nice .Here we go again!


----------



## mordy

Hi Collecto R13,
  
 I don't have experience with the Sylvania 6HM5 so I can't tell if they are good or not. However, I do know that the EI 6HM5 Yugo tubes are very good, and you can use them unmodded. If you don't want to go to the 12AX7/6DJ8 or octal 6SL7 families that would be my first choice. In addition, they are very inexpensive as premium tubes go.
  
 However, building the adapters for the above mentioned tubes will take your LD amp to new heights with a very significant improvement. As they say in the car rental business - a triple upgrade....


----------



## mordy

If you want a good subwoofer very cheap, here is an excellent deal:
  
 http://slickdeals.org/permadeal/109700/newegg---polk-audio-psw10-10-powered-subwoofer-black
  
 This a Polk PSW10 50W self powered subwoofer for $50.00 including shipping (usually no sales tax). Sold by Newegg which is an A+ company.


----------



## kvtaco17

collector13 said:


> I would be able to get some made by sylvania for cheap.
> Are they good too or maybe better?


 

 I have the Sylvanias and they are excellent


----------



## Kestovitutus

collector13 said:


> I would be able to get some made by sylvania for cheap.
> Are they good too or maybe better?


 
 I find the Yugos good, but they have little bit "metallic" sound in my gear. 
 Sylvania 6HM5 has very good highs and very pronouncive bass, but they can sound little bit "crowded" in upper mids/highs.


----------



## CollectoR13

So, I think I am going half octal now 
I will buy a Adapter for Power tubes 6n6p to 6sn7, but the one that was available on eBay seems to be not available anymore...
What would you recommend as a good 6sn7 Tube (endgame?)?
And sure I am getting some yugo 6hm5s


----------



## gibosi

collector13 said:


> So, I think I am going half octal now
> 
> 
> 
> ...


 
  
 The General Electric 6HM5 made by Mullard in Great Britain is also a very good choice, IMO. 
  
 ``````````
 Some on this forum have experience using the 6SN7 as a driver tube, but I do not think I have seen any postings about using it as a power tube. You may be one of the very first to do this....
  
 As to an end-game 6SN7, if you go by price and internet reputation, then it would have to be the Tung Sol with black glass and black round plates, such as these:
  
 http://www.ebay.com/itm/PAIR-VT231-NOS-TUNG-SOL-6SN7-1940s-6SN7GT-TUNGSOL-/171120565209?pt=Vintage_Electronics_R2&hash=item27d7949bd9
  
 I have yet to try a 6NS7 (driver tube), but have an inexpensive National Union coming to me.....


----------



## CollectoR13

Wohaa waaaaay to expensive These tung sol XD
Didn't artsi use them as Power tubes on his mkii?


----------



## Artsi

collector13 said:


> Wohaa waaaaay to expensive These tung sol XD
> Didn't artsi use them as Power tubes on his mkii?


 
 I'm using them happily as powertubes. Also they work excellent as drivers. And i mean to use only one tube as driver to drive both channels. And it uses 0.6A heater current, so at your own risk! I have most liked two 6SN7's as power.
 Tung-sol 6SN7GTB's

 And Russian 6N8S from 60's. Newer Russians work very good too as power's. (do not mind made in holland stamp, it is still russian)

 As a driver i have favored sylvania 6SN7GTA.


----------



## MIKELAP

collector13 said:


> Wohaa waaaaay to expensive These tung sol XD
> Didn't artsi use them as Power tubes on his mkii?


 
  


collector13 said:


> Wohaa waaaaay to expensive These tung sol XD
> Didn't artsi use them as Power tubes on his mkii?


 
 They are end game alright heart attack type !


----------



## gibosi

Received my voltage regulator today and am now using 6.3 volts DC to supply the heaters. And yes, it sounds fine. And I am hoping it is quieter, but will need more time....
  
 Rummaging around the basement I found a 24 volt/400ma wall wart from an old cordless drill/driver which should be able to provide about 1.5 amps at 6.3 volts. (If I understand this correctly, we use the formula: Watts = Volts X Amps. So 24 x .4 = 9.6 watts. And then, Amps = Watts / Volts, so 9.6 / 6.3 = 1.5 amps). Much more than is necessary for the 6NS7.....
  

  
 I anticipate that having a built-in voltmeter will be very useful if I want to roll 12.6 and 20 volt tubes in the future. And yes, that is a roll of electrical tape under the socket. The top of the transformer is quite slippery and the socket moves around too much for my comfort. The tape is somewhat sticky and figure it might isolate the socket somewhat from the transformer.  And then a purple rubber band to hold the voltage regulator to the side of the transformer is just a nice design element, I think. lol
  
 Anyway, now I am ready to roll 6NS7s!


----------



## CollectoR13

Mhm so were do I get these damn adapters now? 
The ebay seller doesn't have them anymore...
Do you guys know another source for them or is anybody willing to build me some?


----------



## mojorisin35

I am about to dive into the 6DJ8 pool due to an extremely kind offer from MIKELAP and is I go back and read through the thread when people started to use these I have a few questions. 
 With the Russian tubes 6N23P is it important to get the “P” version or will a 6N2P work as well, better? Worse?
  
 I do not think there are enough Amprex 6DJ8 tubes to choose from LOL. Man I got lost! Is there a consensus on what “The” tube is? I am looking to not break the Bank so no I will not be spending a 1000$ a set. 
  
 To start I am looking for 1 individual to try under 50. Recommendation with link 
  
 Thank you 
 Gary


----------



## Audiofanboy

mojorisin35 said:


> I am about to dive into the 6DJ8 pool due to an extremely kind offer from MIKELAP and is I go back and read through the thread when people started to use these I have a few questions.
> With the Russian tubes 6N23P is it important to get the “P” version or will a 6N2P work as well, better? Worse?
> 
> I do not think there are enough Amprex 6DJ8 tubes to choose from LOL. Man I got lost! Is there a consensus on what “The” tube is? I am looking to not break the Bank so no I will not be spending a 1000$ a set.
> ...


 
  
 The usual fail-safe recommendation for a 6DJ8 is the Amperex "Orange Globe" made in Holland between '67 and '69 with a large halo getter - yes, it is that precise lol.
  
 There are better Amperex & Philips offerings, but they tend to be both much harder to find, and _usually_ more expensive. Finding NOS premium Amperex types is virtually impossible for example.
  
 I actually have an "Orange Globe" 6DJ8 that I don't think I'll be using again, tests 20% over NOS range for each triode and perfect silk writing; it's basically NOS and I used it like 20h. PM me if you're interested, I'll make you a deal 
	

	
	
		
		

		
			





 .
  
 Otherwise, the US Amperex 6922 tubes made in the early 60s are extremely good, and so are the E88CC and E188CC made in Holland, the earlier the better. These can be Philips, Miniwatt, Dario, Amperex, RTC, RT... branded, they're all the same tube provided they were made in the Heerlen factory in Holland.


----------



## Audiofanboy

gibosi said:


> Received my voltage regulator today and am now using 6.3 volts DC to supply the heaters. And yes, it sounds fine. And I am hoping it is quieter, but will need more time....
> 
> Rummaging around the basement I found a 24 volt/400ma wall wart from an old cordless drill/driver which should be able to provide about 1.5 amps at 6.3 volts. (If I understand this correctly, we use the formula: Watts = Volts X Amps. So 24 x .4 = 9.6 watts. And then, Amps = Watts / Volts, so 9.6 / 6.3 = 1.5 amps). Much more than is necessary for the 6NS7.....
> 
> ...


 
  
 Very curious to know whether or not there's an audible difference with the external power supply and regulator!
  
 At any rate, that's a pretty rigged MKI+ lol... Looks more like something on the dashboard of the Delorean in "Back to the Future" than like a tube amp!


----------



## Oskari

mojorisin35 said:


> With the Russian tubes 6N23P is it important to get the “P” version


 
  
 6Н23П aka 6N23P is the basic type code, not a “P” version. The П, or P, means that it is a miniature tube.
  
Edit: Fixed the Cyrillic Н.


----------



## gibosi

mojorisin35 said:


> IWith the Russian tubes 6N23P is it important to get the “P” version or will a 6N2P work as well, better? Worse?


 
  
 Oskari answered your question about "P". But on the chance that you actually asking about a 6N2P.....
  
 The 6N23P is a version of the 6DJ8. The 6N2P is a 6 volt version of the 12AX7, which has no western equivalent. Interestingly, you can use the 6N2P in a socket configured for a 6DJ8. But just so you know, 6N23P and 6N2P are completely different tubes.


----------



## i luvmusic 2

mordy said:


> Hi CollectoR13,
> 
> Buy these tubes from Yugoslavia; offer $4 or $5 each - free shipping. Asking price is $6.95. Look up on Ebay:
> 
> ...


 
 is these tube plug and play?THANKS..


----------



## CollectoR13

Yep, suppose to be.


----------



## gibosi

The 6HM5 is plug and play using the EF95 setting.


----------



## kvtaco17

gibosi said:


> The 6HM5 is plug and play using the EF95 setting.


 
 Yes sir! Reference this for some tubes that work in the stock LD

 http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/1140#post_9392055


----------



## i luvmusic 2

collector13 said:


> Yep, suppose to be.


 
 THANKS


----------



## i luvmusic 2

gibosi said:


> The 6HM5 is plug and play using the EF95 setting.


 
 THANKS


----------



## Ctritical Bill

audiofanboy said:


> Very curious to know whether or not there's an audible difference with the external power supply and regulator!
> 
> At any rate, that's a pretty rigged MKI+ lol... Looks more like something on the dashboard of the Delorean in "Back to the Future" than like a tube amp!


 
  
 I have been using the external power supply with a 6SN7 for a few days now. I wasn't entirely happy as there was some hum and random interference too. A bit of reading lead me to the solution. You need to tie the negative heater lead to ground. This is because when using a wall adapter there is no path to ground for the heater supply at all. I took an old RCA cable, cut off one end, and connected the shield part of the cable to the negative heater lead. Then connected the RCA plug to one of the LD RCA line-out connectors that I don't use. This is a convenient and tidy way to get a ground connection.
 I now have no hum.


----------



## mordy

Just got in a batch of 6DJ8 derivatives. One is a Tung Sol X155/6BZ8 tube. The silk screen says Tung Sol Made in USA 812-3. However, there is an etched designation LC2F on the tube, which looks like a Philips(?)  designation to me.
  
 This tube also has an unusual green insert in the bottom piece of glass. Here is a picture of this exact tube from three different brands - they all look to come from the same source. (The etched codes are slightly different)
  









  
  
  
 The etched code on my tube is LC2F.  Can anybody decipher it?
  
 Semi educated wild guess: In the Philips designation system L stands for Mazda - Belgium. Could this be a Mazda tube made in March 1962?
  
 BTW, the sound is excellent on first impression. Tremendous detail, ferocious slam - *could this be a poor man's 6922*? Or in LD MK9 speak: "Low frequency response can dive deeper, more solid, soprano Alto can be more transparent ."
  
 Shoot out has to wait a little - got another 7 tubes from the same tube family to check out.....


----------



## Audiofanboy

I just sold my left kidney on ebay... Wait no, that's not right. I just managed to win a set of two tubes on ebay that basically are supposed to be _the_ best 6DJ8 types ever made. I paid an unreasonable amount of money for these, compared to all our old pentodes, but reasonable enough if it sounds good in my amp.
  
 So, yeah, one 7L3 delta8B Holland-made Amperex 6922 _pinched waist_ D-getter, along with a 7L4 delta9E Holland-made 6922  D-getter (regular waist).
  
 I just couldn't resist when I saw that the price wasn't even that high all in all (the last pairs of pinched waist Holland 6922 I found were auctioned for $600+ and $400+, so it's all very relative in the end; I only ever paid the price of pair of 6N30P-DR for these tubes...).
  
 Anyway, should be an interesting experiment, seeing as this time around there _really_ isn't supposed to be anything _better_. We shall see. I wouldn't worry about selling them easily if I were suddenly strapped for cash...
  
 I also have a single *EDIT: VR*0 *0E US-made Amperex 7308 coming; I paid for it like a week ago, but the seller just doesn't seem that inclined to actually send the darn tube. Bad reviews, they are a-coming, I tell you... Not that I care that much, considering the cheap(ish) price I paid for that tube, compared to the once above...


----------



## gibosi

ctritical bill said:


> I have been using the external power supply with a 6SN7 for a few days now. I wasn't entirely happy as there was some hum and random interference too. A bit of reading lead me to the solution. You need to tie the negative heater lead to ground. This is because when using a wall adapter there is no path to ground for the heater supply at all. I took an old RCA cable, cut off one end, and connected the shield part of the cable to the negative heater lead. Then connected the RCA plug to one of the LD RCA line-out connectors that I don't use. This is a convenient and tidy way to get a ground connection.
> I now have no hum.


 
  
 The LD 1+ has only one pair of RCA jacks, Audio In, so no unused jacks....  I guess I need to figure out another way.....


----------



## TrollDragon

gibosi said:


> The LD 1+ has only one pair of RCA jacks, Audio In, so no unused jacks....  I guess I need to figure out another way.....


 

 A wire from the filament negative to any of the case screws should suffice as well.


----------



## gibosi

Finally, to finish the Amperex face-off, is a Heerlen E188CC, VR2 1960. Aside from the very old and rare tubes that AFB has just snared, this is the queen of the Amperex line. Comparing it to the Heerlen E88CC, VL6, 1961, I found it to have essentially the same sound signature, with lush mids and great detail. But I felt that the E188CC was a tad bit quieter, and hence, a bit more detailed.
  
 And then I thought I should roll in a 1960 BugleBoy and a 1967 Orange Globe. These two tubes have a sound signature very similar to the E188CC with that same characteristically lush, liquid mid-range. I would say that these tubes give you 90% to 95% of a E188CC.
  
 So, are the E88CC and E188CC really worth the premium price? I would say yes with some qualifications.
  
 These premium tubes are quieter, they have better detail, and they will last longer. In the case of the E188CC, the fact that the two triodes are very closely matched will provide better balance. So if extreme detail is your thing, then of course you should get these tubes. However, if you have been happily enjoying a late 1960s Orange Globe with a halo getter, these refinements will likely not knock your socks off. I find them to be very subtle. So I encourage you to continue to enjoy that Orange Globe. And if you do happen to stumble across a very good deal on a Heerlen E88CC or E188CC, grab it knowing that you are going to like it. 
  
 And with this, I have finally worked through my stable of Philips tubes....
  
 Next up will be the Voskhod 6N23P (X-75). Recently, this has been my go-to tube. It has great liquidity and flow, and it is also very detailed and transparent. In very complex passages one can follow each instrument with ease, everything is very clear and distinct. However, I have not yet had a chance to directly compare it to the best of the Heerlens, the E188CC....


----------



## gibosi

trolldragon said:


> A wire from the filament negative to any of the case screws should suffice as well.


 
  
 I will give this a try! Thanks!


----------



## mojorisin35

I am so pumped to play with the big boys....that is all


----------



## mojorisin35

kestovitutus said:


> I find the Yugos good, but they have little bit "metallic" sound in my gear.
> 
> Sylvania 6HM5 has very good highs and very pronouncive bass, but they can sound little bit "crowded" in upper mids/highs.





With the yugos I felt the same way as well when they were new however after 20-50 hrs it is gone. Top notch if you can hang in there.yrmv
Gary


----------



## Audiofanboy

gibosi said:


> Finally, to finish the Amperex face-off, is a Heerlen E188CC, VR2 1960. Aside from the very old and rare tubes that AFB has just snared, this is the queen of the Amperex line. Comparing it to the Heerlen E88CC, VL6, 1961, I found it to have essentially the same sound signature, with lush mids and great detail. But I felt that the E188CC was a tad bit quieter, and hence, a bit more detailed.
> 
> And then I thought I should roll in a 1960 BugleBoy and a 1967 Orange Globe. These two tubes have a sound signature very similar to the E188CC with that same characteristically lush, liquid mid-range. I would say that these tubes give you 90% to 95% of a E188CC.
> 
> ...


 
  
 Quoting gibosi, as per usual, makes it look we're doing some kind of warped comedy show about tubes, but whatever.
  
 Re the Heerlen E188CC VR2 1960: indeed, after some moments of doubt with that tube after 30h or burn-in, a simple switch to the US 6922 made me realize a few things. First, the E188CC is quiet, _dead__ quiet_; and that black background really helps details stand out in a natural way with a texture of sorts. And second, that tube is good, like really good. Though I still miss a little of that bass punch the US 6922 has, the E188CC - the early models at least, can't vouch for the later ones - does everything else better. After 50+ of burn-in, I have little doubt that this is my best tube. Maybe not for long lol, but my best tube.
  
 I really believe that it's worth paying a little extra for, honestly. This could be your end-game tube, and it is for many Lyr users. Again, you can buy singles with a Dario or RT, or even Mullard brand for very decent prices (no, not $8 per triode lol, but hey if they last double the time a regular double triode does, can't we say it's worth _four _triodes, so $32?). All it takes is patience; and a little cash, granted. I'm using a new method with 6DJ8 tubes personally: no more museum-like collecting of otherwise useless tubes; now I just sell all the - rather premium - tubes I buy and know I won't be using. I just can't afford to have 30-200$ tubes collecting on a shelf, and it always makes someone else happy to get premium tubes easily lol (and it helps finance my ever more expensive tubes too, somewhat...).
  
 Gibosi, did you ever reach a conclusion on the French Suresnes (10 miles away from my house) made E188CC? I keep reading that that tube is like the _alternative_, not the best of the best, but an excellent take on the E188CC type that many prefer to the Heerlen ones. Is that so? Or should people just focus on getting that Groupon order of cheap Heerlen E188CC going instead lol?


----------



## CollectoR13

collector13 said:


> Mhm so were do I get these damn adapters now?
> The ebay seller doesn't have them anymore...
> Do you guys know another source for them or is anybody willing to build me some?




No Ideas?


----------



## TrollDragon

Which adapters are you talking about?


----------



## CollectoR13

Adapters to use 6sn7 instead of 6n6p.
They were discussed few pages back and there was a ebay link, but the auction ended and Google didn't help at all...


----------



## TrollDragon

These ones here will work as the 6CG7 has the same pinout as the 6N6P.


----------



## gibosi

audiofanboy said:


> Gibosi, did you ever reach a conclusion on the French Suresnes (10 miles away from my house) made E188CC? I keep reading that that tube is like the _alternative_, not the best of the best, but an excellent take on the E188CC type that many prefer to the Heerlen ones. Is that so? Or should people just focus on getting that Groupon order of cheap Heerlen E188CC going instead lol?


 
  
 I have a Suresnes E88CC VL8 1967. It has a sweet lush mid range similar to the Heerlen tubes, with great detail and a bit more treble presence. As one might surmise, that extra treble presence makes a rather bright tube even brighter. With some recordings, I quite liked it. But with other recordings, it was just a bit too bright for me. However, I think I would agree that it is an excellent take on the Heerlen sound. And it may well be an end-game tube for those who prefer a bit more treble punch.


----------



## Audiofanboy

gibosi said:


> I have a Suresnes E88CC VL8 1967. It has a sweet lush mid range similar to the Heerlen tubes, with great detail and a bit more treble presence. As one might surmise, that extra treble presence makes a rather bright tube even brighter. With some recordings, I quite liked it. But with other recordings, it was just a bit too bright for me. However, I think I would agree that it is an excellent take on the Heerlen sound. And it may well be an end-game tube for those who prefer a bit more treble punch.


 
  
 Ok, so it does seem kind of like an _alternative_ in the end. I thought you had an E*1*88CC from Suresnes; actually I'm not even sure whether or not these exist, considering I don't believe I've seen Mullard UK-made E188CC tubes either...
  
 So Suresnes for treble punch, Heerlen for midrange glory, and New York for bass punch, I guess...?
  
 Edit: Nevermind, I just saw some Mullard-made E188CC on ebay...


----------



## Oskari

mordy said:


> Just got in a batch of 6DJ8 derivatives. One is a Tung Sol X155/6BZ8 tube. The silk screen says Tung Sol Made in USA 812-3. However, there is an etched designation LC2F on the tube, which looks like a Philips(?)  designation to me.
> 
> This tube also has an unusual green insert in the bottom piece of glass.


 
  
 That is unusual!
  


> The etched code on my tube is LC2F.  Can anybody decipher it?
> 
> Semi educated wild guess: In the Philips designation system L stands for Mazda - Belgium. Could this be a Mazda tube made in March 1962?


 
  
 It's not a Philips-style factory + date code. The format is: factory code character, last digit of year, letter for month, optional digit for week of month. Also, there should be a type + change code somewhere close by.
  
 322, which you can see in the Tung-Sol photo, is Tung-Sol's EIA manufacturer code (but you can't always trust those).


----------



## gibosi

audiofanboy said:


> Ok, so it does seem kind of like an _alternative_ in the end. I thought you had an E*1*88CC from Suresnes; actually I'm not even sure whether or not these exist, considering I don't believe I've seen Mullard UK-made E188CC tubes either...
> 
> Edit: Nevermind, I just saw some Mullard-made E188CC on ebay...


 
  
 I have seen Mitcham E188CC (VR1-R0A1, but with dimpled getters, these are 1970, rather than 1960), and RTC printed on the tube. I wonder if there are Blackburn E188CC?


----------



## Audiofanboy

gibosi said:


> I have seen Mitcham E188CC (VR1-R0A1, but with dimpled getters, these are 1970, rather than 1960), and RTC printed on the tube. I wonder if there are Blackburn E188CC?


 
  
 Hmm, yeah most Mullard-made E188CC and E88CC variations I see seem to be from later times; for example I keep on bumping into RTC branded E188CC but made by Mullard veeeery late in the tube era - actually like 20 years after lol - with late 70s or 80s codes.
  
 But no, I don't believe I've seen Blackburn-made Mullards for those types.
  
 Quick piece of tube trivia on the earliest, almost prototype-like, Philips Holland E88CC. What I just bought is a 7L3 pinched waist tube, made in Heerlen Holland, which is the last batch to actually have that feature. That batch lasted from sometime early-mid 1957 to late mid-late 1958 - which is a long time compared to other batches.
  
 7L2 and 7L3 tubes were made with _silver-plated_ inner wires, which is one of the reason they're supposed to sound so good; most were made in the Heerlen factory, but some 7L2 may have also been made the Eindhoven factory - yeah, that factory that's always in the Philips code lists but never on a tube.
  
 But even before those batches, you could find - virtually extinct now - 7L0 and 7L1 batches made in the Eindhoven plant, and made with _gold-plated _inner wires, which is supposed to be a part of what makes them so good. People seem to say that both the earlier Eindhoven gold-grid revisions and the later Heerlen silver-grid revisions are top tier; some say that the 7L0 and 7L1 are more desirable, but the few people that actually found, bought and tested both seem to say that they're just different. So the pinched waist "trait" seems more important than the grid material used. Not that this matters since _all_ those tubes are rare and cost a leg.
  
 Much credit is also given to the 7L4 and 7L5 _non_-pinched waist D-getter E88CC made in Heerlen, but people say these tubes don't quite have the "magic" - hey, I didn't write this you know, people all over the web do lol - the pinched waist versions do.
  
 As far as US-made Amperex pinched waist 6922 go - they're even rarer... - it seems the batches available start a bit later in time and would mostly be 7L4 from '59, maybe earlier. Again, it's hard to even find information on these...
  
 E188CC are a different story. The D-getter, Heerlen-made, ones from the VR0, VR1, and _part_ of the VR2 batches from years late 1959 to mid 1960 are clearly more desirable than anything that came after. Why? How? Not many people seem to actually be able to say, but that's the consensus anyways.
  
 US-made Amperex 7308 tubes follow the same logic: the earliest 1960 D-getter VR0 batch is supposed to be a whole notch above anything that came afterwards and have a "magic" to it - whatever that means. It's ultra rare anyways, but good to know.
  
 Apparently - and I say this both from my experience with the US 6922 and from extensive googling - anything Amperex made in the US beyond 1962, while excellent, just isn't as musical as what came before in the US or in the same time frame in Holland. The difference I heard between a '62 and a '64 US-made 6922 was so striking it kind of convinced me (don't know if gibosi has such a strong feeling about this?).
  
 So, for US Amperex, if you're going to fork the major cash to get something good, either aim for the earliest 7308 in 1960, or the 6922 no later than 1962. Most people on ebay don't seem to have picked up on that huge difference between early and late 60s US 6922 tubes, so whether you buy a 1961/62 O-getter 6922 or a 1966 one, you'll essentially see the same prices. So go for the _earlier _ones!
  
 Holland production follows the same pattern, but the cut-off in sound quality is more between D-getter tubes until 1960 and later halo-getter tubes. The early tubes are much better, and sadly people know about it, so prices are indecent... But again, if you're going to fork the cash, the _earlier the better_.
  
 Sorry I'm ranting again, but I figure _someone_ is bound to find _something_ useful in there. At least it save the hours scouting random opinions in pagan languages on google lol...


----------



## gibosi

audiofanboy said:


> Apparently - and I say this both from my experience with the US 6922 and from extensive googling - anything Amperex made in the US beyond 1962, while excellent, just isn't as musical as what came before in the US or in the same time frame in Holland. The difference I heard between a '62 and a '64 US-made 6922 was so striking it kind of convinced me (don't know if gibosi has such a strong feeling about this?).


 
  
 Yes, I had the same experience...  I have a US 6922 7L6 1961, a US 6922 7L9 1964, and a US 7308 VR5 1966. And it isn't even close. The 1961 6922 is heads and shoulders above the others.


----------



## CollectoR13

trolldragon said:


> These ones here will work as the 6CG7 has the same pinout as the 6N6P.



Too good to be true...
He doesn't ship to germany...
I am asking the seller if he is somehow agreeing to ship to germany.
Otherwise I have to find another source for these adapters.


----------



## mordy




----------



## TrollDragon

mordy said:


> Hi CollectoR13,
> 
> Did you check this source?
> 
> ...


I think he is looking to plug an octal in as a power tube, so that would be backwards.


----------



## Artsi

mordy said:


> Hi CollectoR13,
> 
> Did you check this source?
> 
> ...


 
 If photo is correct, you need first B9A to octal adapter that you can again use 6N6P after this?


----------



## TrollDragon

@CollectoR13
  
 These ones here would work *but would require a minor rewiring inside*. They look like they are held together with a hex screw, as long as they are not potted inside it should be an easy conversion.
  
 Contact the seller, I have bought sockets from this seller before and he just might make you the ones you need.
http://www.ebay.com/itm/2ps-convert-tube-socket-12AX7-12AU7-to-6SL7-6SN7-9-pin-to-8-pin-/281034346185


----------



## MIKELAP

trolldragon said:


> @CollectoR13
> 
> These ones here would work *but would require a minor rewiring inside*. They look like they are held together with a hex screw, as long as they are not potted inside it should be an easy conversion.
> 
> ...


 
 But if you do be prepared to wait he's using snail mail but your closer then me . I ordered on 16 november


----------



## mordy

HI TD,
  
 You are 100% right! I realized my mistake and cancelled the post - at least so I thought.... Post #4403


----------



## Beef Anus

Do the Mullard M8161 work with the mk iii?


----------



## mojorisin35

beef anus said:


> Do the Mullard M8161 work with the mk iii?


 
  
 yes they sure do


----------



## mordy

Continuing my exploration of my newly acquired stash of 6DJ8 derivatives. Have you ever heard of Coronado tubes? Neither have I, until now. Here are two action pictures of my 6BC8 tube:
  


  
 Obviously, Coronado is a re-brander, but who made this tube? No information on the tube except the name, designation, and a yellow rectangle. Let's look at the box: In fine print it says Gamble-Skogmo Inc, Minneapolis, MN. (Artsi and Oskari know that Skogmo means wood marsh - there were many Swedes that settled in Minnesota.) The bottom inside flap says BC-646 with the number 37 underneath.  Perhaps this tube could have been made in June 1964. (1946?)
  
 Next stop Google. Gamble-Skogmo was founded in the 20's selling cars and started to produce radios in 1935. This company encompassed many different businesses, stores and department chains and grew to be the 15th largest US retailer in the 70's with 4300 stores under many names and 26,000 employees. When one of the founders retired in the late 70's the company was sold. The new owners drove the company into bankruptcy and it went under with many divisions sold off.
  
 For you designers out there, here is a picture of a beautiful 50s-60s Coronado tube radio:
  





  
 If you live near Colorado Springs, this tube radio console is available for local pick up for $195.00:




  
 http://www.ebay.com/itm/Vintage-Antique-Vacuum-Tube-CORONADO-Console-Radio-Professionally-Tested-WORKS-/301041001384?pt=Vintage_Electronics_R2&hash=item46177123a8
  
 Back from our history detour to the the tube. It has the 6DJ8 signature sound of very wide sound stage, punchy bass (in this case extra punchy) and great treble with tons of detail. A light, quick and lively presentation. The treble is slightly bright, but this tube has not been burnt in yet.
 The manufacturer? No clue, perhaps Raytheon. My only hunch is the yellow rectangle which reminds me of the yellow silk screening on some US Raytheon tubes.
 Another winner.


----------



## gibosi

audiofanboy said:


> Very curious to know whether or not there's an audible difference with the external power supply and regulator!


 
  
 From the beginning, my flying wire adapter has been plagued with random RF noise which I assumed was due to all the exposed wires. In fact, the noise would often increase or decrease as if I moved the amp around. And therefore, I had thought that the solution was shorter wire runs and perhaps some shielding. However, now that I have an external DC power supply for the heater filaments, the amp is dead quiet. To those who might be experiencing similar noises, I strongly recommend an external DC power supply to supply power to the heaters.  It is cheap and it works.
  
 If you don't have a suitable wall wort, something like this is what you need:
 (24V will allow the use of 6.3, 12.6 and 20 volt tubes)
  
 http://www.ebay.com/itm/350833307159?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649
  
 And you will also need a voltage regulator:
 (I chose this one because I wanted an LED readout and the vendor is located in the the US, ensuring fast delivery) 
  
 http://www.ebay.com/itm/131062144956?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649
  
 I have the amp and wall wort plugged into a surge protector and use it to turn both the amp and wall wort on and off. Doing this means I don't have to worry about inadvertently leaving the heaters on when the amp is turned off. And further, I ran a small piece of wire from the negative out terminal on the voltage regulator to the closest LD chassis screw to provide a suitable ground path.
  
 I wish to thank Ctritical Bill and TrollDragon for giving me a path to follow. I am learning a lot from you guys!


----------



## mordy

Hi Gibosi,
  
 How do you regulate the voltage? By turning the little brass screw?
  
 Does it matter how you connect the heater wires 3 and 4 on the Vector?
  
 Would you mind taking a picture showing the heater wires and the grounding arrangement?


----------



## TrollDragon

gibosi said:


> I wish to thank Ctritical Bill and TrollDragon for giving me a path to follow. I am learning a lot from you guys!


 
  
 My pleasure, anytime.


----------



## gibosi

mordy said:


> Hi Gibosi,
> 
> How do you regulate the voltage? By turning the little brass screw?
> 
> ...


 
  
 Yes, you turn the little brass screw to adjust the voltage. And no, you do not connect this to the Vectors. This would likely be very bad. Instead, disconnect the wires currently connecting Vector pins 3 and 4 to the 9-pin socket pins 4 and 5. I put some electrical tape around the ends in case I want to use the LD's heaters again.
  

  
 Run wires from the voltage regulator OUT to pins 4 and 5 on your 9-pin socket, and connect negative OUT to chassis screw.


----------



## mordy

Many thanks for the explanations and pictures - I think that I understand how to do it now.
  
 May I suggest two small velcro self stick fasteners for the voltage regulator module instead of the rubber band - will make it stay in place and it can be removed easily.
  
 Hope that the grounding will cure the hum I hear when I turn up the volume loud (higher than normal listening volume).
  
 All the best,


----------



## TrollDragon

Good point mordy, I would put something behind that regulator as the transformer case is just paint. If there are any component leads poking through the board they could scratch the paint and short out on the metal beneath.


----------



## gibosi

Point taken. I have put a piece of felt fabric between the transformer and the voltage regulator for the time being.


----------



## Ctritical Bill

I have made up some 9 pin adapters so that I can run the power tubes out of their sockets and can take some measurements.
 So in the LD Mk111 with stock 6N6P power tubes and some Mullard EF95 driver tubes this is what I recorded.
  
LEFT
   Heater    6.43v
   Plate      105.8v   208.0v
   Cathode  2.16v    108.0v
  
RIGHT
   Heater    6.44v
   Plate      105.6v   207.9v
   Cathode  2.26v    108.0v
  
 The heaters are a little high but within 5% of 6.3v so not bad. The 6N6P draws 750ma and the transformer is rated at 6.8v 2.5 amp so about what you might expect.
  
 The second plate reading is the B+ value minus the plate resistor multiplied by the current which is an almost insignificant amount so we can safely say the B+ is 210v.
 The cathode readings ( grid bias ) show a little inbalance between my tubes but otherwise good standard values.
  
 Theses readings give a calculated value of 10ma through the power tubes at idle. This is where I have a problem. Looking at the datasheet for the 6N6P at 105v plate and 2.2v grid the tube should be giving about 20ma. That doesn't fit with my readings so either I have made a mistake or the tubes are worn and not producing much current.
 Interestingly, if you look at the datasheet of the Electro Harmonix 6H30Pi at the same plate and grid values that tube produces about 60ma, quite a difference.
  
 I don't know if any of this will be of interest to anyone but now I have an idea of what is going on with the power tubes I am going to try some different tubes that might be suitable.
  
 {EDIT}
  
 I tried some 6N5P as power tubes as I have some handy and they looked suitable from the datasheet. They work very well. Sound a liitle more detailed than the 6N6P and possibly a better soundstage too. I will keep them in as I like how they sound.
 These have about 15ma through them and  I would have expected the B+ voltage to drop a little compared to the 6N6P if they were producing more current but the opposite is true. I have been basing my calculations on a cathode resistor value of 220 ohm from Trolldragon's schematic but the values I am getting suggest it may be more like 100 ohm. I have the LD mk111 with a ver. 4 board so maybe the values have changed. Anyway, with a cathode resistor value of 100 ohm the 6N6P is putting out just over 20ma which agrees with the datasheet so I am going with that value.


----------



## kvtaco17

Ok, after much wait... I'm in... this rig is temporary... the aluminum enclosure for the tube adapter and more permanent connections to the little dot socket savers will be done soon... Starting with the Teslas!


----------



## Argybargy

Subbed. 
Thanks Gibosi, looks like a lot of fun.


----------



## TrollDragon

Well all the ceramic machined sockets have arrived from China...

  
 Built a 6DJ8 to octal adapter so I could listen to the 6BQ7A's that MIKELAP sent me.

  
 Nice tube I like it, thanks MIKELAP!




*до свидания*


----------



## gibosi

RE: Little Dot 1+ op amps:
  
 For some time, I have been running the MUSES 02 op amp in my LD 1+, but have been wondering about the MUSES 01, which some believe is even better, so decided to give it a try. 
  
 The 01's stage seems a bit wider, but this is not to say that the stage on the 02 is narrow. The 01 has a bit more grain. It is not as fluid and liquid as the 02. The 01 has less bass presence than the 02, With less bass, the mids and treble are relatively brighter. And the 02, with more bass, is relatively blacker and darker.
  
 With the Heerlen E188CC, which has that glorious wet mid range and great liquidity and flow characteristic of the Heerlen 6DJ8 family, putting the 01 in, there was less flow and the mid range was a bit drier. Putting the 02 back in, the flow came back and mid range was glorious again.
  
 The MUSES 02 is back in to stay.


----------



## mordy

Hi Trolldragon,
  
  
 До свидания!
  
  
 If you like the 6BQ7, then I would recommend the 6BC8 aka 6BZ8 aka X155, which I feel is better sounding. The question is, are these tubes the equal of the 6N23P or dare I say the 6922/7308?
  
 Let the comparisons begin! There is no doubt that the value is superior compared to the expensive Amperex tubes. I am eagerly waiting to hear from others who have tried these tubes, especially comparing them to the gold pin standard of the A tubes....
  
 Meanwhile, I still have several more 6BC8 and 6BZ7 tubes to burn in, so I have to wait to do my shootout.


----------



## TrollDragon

mordy said:


> Hi Trolldragon,
> 
> 
> До свидания!
> ...


 
 Thanks mordy!
  
 I will look into those, they are a very reasonable price.
 I do have some tubes on the way though that should keep me busy for quite a while.


----------



## Sumor

Hi, I skimped through but interesting thread. I was interested in the Little Dot MKII. Would it be possible to roll 2x GE JAN 5814A tubes in those?


----------



## gibosi

sumor said:


> Hi, I skimped through but interesting thread. I was interested in the Little Dot MKII. Would it be possible to roll 2x GE JAN 5814A tubes in those?


 
  
 5814A appears to be an industrial version of the 12AU7. Therefore, if you set up your LDII to run 9-pin dual triodes, you can use these tubes. All you have to do is configure the heaters on your 9-pin socket so that you can run the 12AU7 tubes on 6.3 volts like so:
  
 http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/3630#post_9911760
  
 Cheers


----------



## gibosi

mordy said:


> Can anybody suggest inexpensive driver tubes that may work well with the higher current external power source for the heaters. The only thing that comes to mind is the 6SN7GT octal, but I remember seeing others being mentioned.


 
  
 Has anyone suggested 6CG7 / 6FQ7? These are electrically equivalent to the 6SN7GT, but in a miniature 9-pin form, and therefore, like the 6SN7, they require 600ma. Further, they appear to be pin-compatible with the 6DJ8, so easy. There is also an 8 volt version, 8CG7


----------



## gibosi

There has been some speculation that when running tubes with an internal shield, such as the 6DJ8, it might be preferable to tie the shield directly to ground. This evening, I did just that. I tied the shield to the same chassis screw grounding the external heater circuit. But unfortunately, the ground hum persisted..... So until we learn better, it appears that we should continue to tie the shield to the cathode of the right triode. That is, tie pin 9 to pin 8 for 6DJ8-type tubes.


----------



## Sumor

Looks complicated gibosi, I'm totally lost. Got ebay links to the adapters and anything that is required to begin? Cheers


----------



## gibosi

sumor said:


> Looks complicated gibosi, I'm totally lost. Got ebay links to the adapters and anything that is required to begin? Cheers


 
  
 Yes, it is a little complicated. Little Dots were never intended to run double triodes, so you will have to cobble together an adapter of some sort. My best advice is to start reading on page 220 of this thread. This is the point where we begin to experiment with different ways to use these tubes.
  
 http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/2985#post_9817399
  
 In this way, you can understand what is necessary to run double triodes, and you can see a number of adapters, from shiny copper steampunk to my flying spaghetti contraption. Yes, it will take some time to read through the last 96 pages, but again, it is a little complicated. Once you had done that and have decided how you wish to proceed, we are here to help. 
  
 Cheers


----------



## Audiofanboy

gibosi said:


> Yes, it is a little complicated. Little Dots were never intended to run double triodes, so you will have to cobble together an adapter of some sort. My best advice is to start reading on page 220 of this thread. This is the point where we begin to experiment with different ways to use these tubes.
> 
> http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/2985#post_9817399
> 
> ...


 
  
 Good Lord... Has it really almost been 100 pages since the "Flying 12AT7" experiment? Time flies... Not that I have any regrets about switching over to double triodes, as it's been by far the largest improvement on my amp!
  
 I'm hoping to be able to give impressions of the three different Amperex (Philips) tubes I ordered by the end of month - either before or after the usual new year's eve craziness.
  
 Even though my current 1960 E188CC are outrageous, the wait is kind of killing me, considering I'm also expecting a mains filter (same one Acapella presented 6 months back), a new silver-plated OCC interconnect and headphone cable, new pads for my HE-500, and that _none_ of these seem to be getting to me very fast... I usually like to make changes one by one, so it easier to analyze the differences; but this time around I might kind of get everything at once, so I'm hoping I'll still be able to pick out the improvements brought by each separate element.


----------



## mordy

Hi Gibosi,
  
 " 6CG7 / 6FQ7  - These are electrically equivalent to the 6SN7GT, but in a miniature 9-pin form, and therefore, like the 6SN7, they require 600ma. Further, they appear to be pin-compatible with the 6DJ8,"
  
 So, if I understand you correctly, I could plug in the 6CG7/6FQ7 tubes directly into my 6DJ8 adapter, and then use a separate external power supply with a voltage regulator to power the heaters and this would work with the MKIII without any other modifications?
  
 Could I use an 8V tube in the LD MKIII if I had the voltage regulator with external power supply and set the heater voltage at 8V?
  
 If this is correct, could I also use 7DJ8 tubes in the LD?


----------



## kvtaco17

Mordy,

I briefly looked into the same thing and it looks like that would work. I had been trying to research the next step in our tube journey while I catch up on 6dj8's lol


----------



## gibosi

mordy said:


> So, if I understand you correctly, I could plug in the 6CG7/6FQ7 tubes directly into my 6DJ8 adapter, and then use a separate external power supply with a voltage regulator to power the heaters and this would work with the MKIII without any other modifications?
> 
> Could I use an 8V tube in the LD MKIII if I had the voltage regulator with external power supply and set the heater voltage at 8V?
> 
> If this is correct, could I also use 7DJ8 tubes in the LD?


 
  
 Yes, Yes and Yes. 
  
 Yes, since the 6CG7/6FQ7 draws 600ma, more than we think the LD can safely provide, it is recommended that you use an external ps.
  
 Yes, if you have an external ps, you can easily "dial in" 8 volts and you are good to go. Since this is a bit of an oddball voltage, these tubes tend to be pretty cheap.
  
 And yes, although, actually you can safely use 7DJ8 tubes with 6.3 volt heaters, no problem. This is common practice among the Schiit Lyr crowd, and I have used a number of 7DJ8/PCC88s (Tesla, Valvo and Siemens) in my amp and they work fine. But if you want to be "datasheet perfect", you can dial in 7 volts.


----------



## gibosi

audiofanboy said:


> Even though my current 1960 E188CC are outrageous, the wait is kind of killing me, considering I'm also expecting a mains filter (same one Acapella presented 6 months back), a new silver-plated OCC interconnect and headphone cable, new pads for my HE-500, and that _none_ of these seem to be getting to me very fast... I usually like to make changes one by one, so it easier to analyze the differences; but this time around I might kind of get everything at once, so I'm hoping I'll still be able to pick out the improvements brought by each separate element.


 
  
 Santa is coming early to your place! I sure hope he will have at least a trinket or two left for me! lol 
  
 Currently, my (probably identical to yours) 1960 Heerlen E188CC and 1975 (October) Voskhod are my two top tubes. They are both very quiet, with great detail, and superb flow and liquidity. The Voskhod seems to have a bit more bass presence, with a bit more punch, and the mids are just a bit less forward, but otherwise, they have a very similar sonic signature. I find myself preferring the Voskhod by a hair. However, I don't think the Voskhod is "better". I think it is the synergy between the Voskhod and the rest of my system that is just a little better....
  
 Next, I want to spend some serious time with the Western Electric 396A/2C51. But first, I think I will take a short break and try to simply enjoy my amazing LD 1+...


----------



## Audiofanboy

gibosi said:


> Santa is coming early to your place! I sure hope he will have at least a trinket or two left for me! lol
> 
> Currently, my (probably identical to yours) 1960 Heerlen E188CC and 1975 (October) Voskhod are my two top tubes. They are both very quiet, with great detail, and superb flow and liquidity. The Voskhod seems to have a bit more bass presence, with a bit more punch, and the mids are just a bit less forward, but otherwise, they have a very similar sonic signature. I find myself preferring the Voskhod by a hair. However, I don't think the Voskhod is "better". I think it is the synergy between the Voskhod and the rest of my system that is just a little better....
> 
> Next, I want to spend some serious time with the Western Electric 396A/2C51. But first, I think I will take a short break and try to simply enjoy my amazing LD 1+...


 
  
 Really?! So you basically rate the - actually difficult to get a hand on - 1975 Voskhod above the early US Amperex 6922, if I understand correctly? Interesting. Of course the _best_ Voskhod tubes are almost as hard to find as some crazy Philips tubes now, albeit less expensive, so that doesn't even help that much lol...
  
 Again, I'm waiting on those three Philips-group tubes I ordered mainly for the pleasure of listening to them, but also to essentially get a feel for what "ceiling" or "limit" exists in that tube family.
  
 For all I know, I might discover that, contrary to common folklore, the 7L4 non-pinched-waist Holland E88CC is better or as good as the 7L3 PW E88CC, or that the earliest US 7308 are better or whatnot. _Who knows..._
  
 At this point where many here on this thread would rather ramp things _down_, I find myself kind of looking for a "standard meter" of sorts, against which I could basically gauge other tubes, even if it meant paying a little extra for it. Hopefully, at least one of those three tubes should give me a good idea of wherein the "small signal tube" limit lies.
  
 Or not... Seeing as there's _always_ been something better up to here...
  
 Looking forward to your review of the 396A! Again, I just hope it will either show us the way of new and better tubes, or just help us narrow tube types down. Anything in between will just be complicated to manage and take a toll on my wallet again lol...


----------



## gibosi

audiofanboy said:


> Really?! So you basically rate the - actually difficult to get a hand on - 1975 Voskhod above the early US Amperex 6922, if I understand correctly? Interesting. Of course the _best_ Voskhod tubes are almost as hard to find as some crazy Philips tubes now, albeit less expensive, so that doesn't even help that much lol...
> 
> Looking forward to your review of the 396A! Again, I just hope it will either show us the way of new and better tubes, or just help us narrow tube types down. Anything in between will just be complicated to manage and take a toll on my wallet again lol...


 
  
 Yes, given my ears and gear, I rate the 1975 Voskhod better than the 1960 Heerlen E188CC and the 1961 US-Amperex 6922, but again, only by a very slim margin.
  
 There appear to be four different versions of the Voskhod 6N23P manufactured in 1975. My favorite has grey plates with the getter supported by what appears to be a sheet-metal extension of the shield. I also have another 1975 Voskhod, with grey plates and a wire getter support rod, but I have not spent any time with it. Ahh....  Something else I need to do!  lol  Further, I am searching for the other two 1975 versions, both with silver shields.....
  
 And yes, I am very curious to discover if the 396A can present a real challenge to the 6DJ8....  But all in good time...


----------



## Ctritical Bill

gibosi said:


> Has anyone suggested 6CG7 / 6FQ7? These are electrically equivalent to the 6SN7GT, but in a miniature 9-pin form, and therefore, like the 6SN7, they require 600ma. Further, they appear to be pin-compatible with the 6DJ8, so easy. There is also an 8 volt version, 8CG7


 

  
 This is my collection of 6CG7/6FQ7.
 From the left we have 2 Super Radiotron 6CG7 made in Australia, then what I think is an RCA with side getter, labelled 6CG7/6FQ7, and lastly, and probably the best, an Amperex labelled 6CG7/6FG7 , made in USA with what looks like the GE pattern of dots.
 I have only tried the Amperex so far and it sounds similar to the 6SN7 with the same wonderful soundstage.
 The tubes labelled 6FQ7 don't have an internal shield and I believe this is the only difference compared to the 6CG7. Supposedly the shield eliminates any crosstalk so they are more sought-after but for us they are easier to use as there is no problem of where to ground the shield.


----------



## mojorisin35

Is 20$a tube a good deal for 1975 Voskhod's?


----------



## superdux

if its the voskhods mentioned on page 1 then i'd say no good deal.You apparently don't need them matched and then they go for 3$ a piece plus postage!


----------



## gibosi

mojorisin35 said:


> Is 20$a tube a good deal for 1975 Voskhod's?


 
  
 I assume you mean the double triodes? 6N23P? No, $20 a tube is not a good deal. I have paid $3 to $6 each for these....


----------



## mojorisin35

yes the  double triodes 6N23P, do you mind pm'ing ,me a link?


----------



## gibosi

I have received my first 6SN7GT this morning. A National Union, dated 5108. It lights up and sounds very musical. However, I have put it aside for now. The Western Electric 396A is next in line. And before that, some R&R for me. 
  

  
 Edit: Oh, I took some measurements:
  
 National Union 6SN7GT 1951 (LD 1+)
  
 Plate R 81.2
         L 81.2
  
 Grid   R 3.1
         L 3.4
  
 Looks pretty good.


----------



## mordy

Hi mojorisin35,
  
 I bought 4 Voskhod 6N23P used tubes (supposedly 100 hours or less on them - saves you the trouble of burning them in) for under $4 each including shipping.
  
 Here is a link - this seller probably has many more:
  
 http://www.ebay.com/itm/USSR-6N23P-6DJ8-6922-DOUBLE-TRIODE-LITTLE-USED-QTY-20pcs-/221338600574?pt=Vintage_Electronics_R2&hash=item3388cf047e
  
 The trick is communication. This seller's English is not the best, and I used Google translate to send my questions and wants in Russian printed out in the Cyrillic alphabet.
  
 http://translate.google.com/#en/ru/The%20trick%20is%20to%20communicate.
  
 I wanted an octal tube as well to save on shipping. This worked out very well, and the seller made a special buy it now listing for me, which I responded to right away. He also sent me an extra octal tube for free!
  
 I ended up with four Voskhod 6N23P 1974 tubes with wire getter, a 1981 Saratov 6N9S (was supposed to be 1961) and another octal tube without any markings except OTK1 which just means Quality Control checker #1 and nothing else. It looks like an old  6N9S tube and sounds fine once I dusted it off.
  
 Good luck!


----------



## Audiofanboy

Late at night on a Saturday in my time zone, but for some obscure reason this seems to be the time when I start browsing Google because I'm curious about something and end up getting new ideas.
  
 So, here it goes, two new ideas, or basically tube types to test - notice how I'm only suggesting frame grid types:
  
 The E80CC/6085, double triode, frame grid construction, center tappable 12V heaters, mu=27, cathode bias resistor needed 920 ohms (LD amps have 680), and very linear. Basically, a cool double triode that's like a 12AU7 but more interesting. Crack addicts... I mean users have tried it instead in the position of a 12AU7 in their amps with great success. Anyway, I have virtually no doubt it would work in our LD amps and sound at least pretty good with the same adapters we used for 12Ax7 tubes!
  
 The C3G, single pentode, frame grid construction, 6.3V heater, mu=40, linear like crazy! But (l)octal base and 180 ohm cathode resistor needed (not that it's ever been an issue up to here, the 2C51 needs a 240 ohms resistor and it worked fine). Basically, a "super critical" pentode made for telecommunication signal repeating - amplification - with ultra low noise and ultra high linearity. Now that's interesting! They'd need custom adapters, but at least we'd be back to using a single tube per channel, which could more esthetically pleasing.
  
 Anyway, just a few ideas. The E80CC is _only_ supposed to be an excellent frame grid double triode, but the C3G are supposed to be some - if not _the_ - best small signal tubes ever made, or so the web says. Then again, the fact that whole amps are built around that tube says a lot about their quality. Anyone who already has octal sockets willing to try it? Testing a E80CC is even easier, barely even a challenge at this point...
  
 Edit: Bonus tube, the D3A, frame grid pentode, noval, 6.3V heater, mu=77, cathode resistor=470 ohms, ultra linear. Great fun!


----------



## mordy

More on the C3G tube:
  
 http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=12&ved=0CG0QFjAL&url=http%3A%2F%2Fwww.audiofaidate.org%2Fuploaded%2Fbaldo95%2FC3g-C3m-info.pdf&ei=yT-2Uo3YJ9LjsATqqYCYAg&usg=AFQjCNH5buVn2Bv3LQwjzhVwlJlV5aa6Rw&sig2=5FCjpjGHHZqtxCqszKG3Bw&bvm=bv.58187178,d.cWc


----------



## mojorisin35

mordy said:


> Hi mojorisin35,
> 
> I bought 4 Voskhod 6N23P used tubes (supposedly 100 hours or less on them - saves you the trouble of burning them in) for under $4 each including shipping.
> 
> ...




Mordy 
Thank you soo much for your link and advice. I have sent off a message and am waiting on a reply ! I cannot wait 

Gary


----------



## gibosi

Am I the only one listening to 2C51/396A/5670 through a LD?
  
 Anyway, my curiosity was just too much for me to resist, and accordingly, I decided to compare the Western Electric 396A to my best 6DJ8-types: 1961 US-Amperex 6922/E88CC, 1960 Heerlen 7308/E188CC and 1975 (October) Voskhod 6N32P.
  

  
 In my opinion, the Western Electric 396A compares extremely well with these tubes. It is most similar to the Heerlen E188CC. That is, the US 6922 has a bit more bass and more treble, the Voskhod has more bass presence with laid back mids, and the Heerlen, with that lush midrange, is almost an exact match. Given my ears and gear, the differences between the Heerlen and the Western Electric are too subtle to be revealed easily ... It will take more time...
  
 That said, I rate the Western Electric 396A as a great tube and a relative bargain, not nearly as expensive as the premium 6DJ8-types. I picked up my Western Electric 396A for around $17/shipped. Highly recommended.
  
 ~~~~~~~~~~~~~~~~~~
  
 How to use:
  
 If you have a breadboard 9-pin socket, the right triode connections are the same as for the 6DJ8, but the left triode and heater connections are different:
  
 http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/4110#post_10021890
  
 However, I am using a 2C51 to 6DJ8 adapter, which makes rolling these tubes much easier:
  
 http://www.ebay.com/itm/260723522614?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649
 (Although this listing is for two adapters, the vendor agreed to send me only one adapter and accordingly reduced the price by half.)


----------



## mordy

Hi Gibosi,
  
 I have two breadboards with Vector adapters, one for 12AX7 that I can also use with an adapter for octal tubes. The second breadboard is set up for 6DJ8 type tubes.
  
 Instead of switching in and out the two different breadboard contraptions, could I plug in the Vectors on top of each other and leave out one of the tubes? Would the amp think that I am only using one breadboard?
  
 Next, to use the Western Electric 396A, could I make up a fifth Vector and attach it to the second screw fitting available for each of the breadboard leads while unplugging the Vector adapter that is different for the 6DJ8?
  
 Hope I am making myself clear....


----------



## TrollDragon

Don't mean to interject here, but you could just run parallel wires to the other breadboard hooked up for which ever tube you want. If you only plug in one tube at a time and power down allowing for the caps to discharge before changing tubes it should be a lot easier than stacking Vectors.... :eek:

Put both bread boards side by side and just run the wires that you need from one to the other. If it doesn't present any hum doing this it would be a grand solution.


----------



## gibosi

Mordy,
  
 What you are proposing will probably work (I think). However, the more complicated your connections (5 Vectors and 2 sockets), the more likely it is that one or more of these connections may fail. Of course, completely swapping out the Vectors and the attached socket each and every time you want to switch between 6DJ8 to 12AX7 would seem to me to be a real hassle, so I certainly understand your motivation. But while your proposal would make it simpler to switch tubes, unfortunately, it would add considerable complexity to the circuitry, and thus, more connections that can go flaky and even fail.
  
 Personally, I find it easy to have only one socket. With only three wiring changes required to switch between 6DJ8 to 12AX7, swapping tubes can be done in just a few minutes, while keeping the number of connections to a minimum. And again, using an adapter for 2C51 tubes is easy and it also helps to keep things simple.
  
 But if you are comfortable with your proposed arrangement, then go for it. I can't see any reason it wouldn't work.


----------



## TrollDragon

Now Everybody Sing!
 "Oh Christmas Tube, Oh Christmas Tube, Your glow is sure enticing."

  
 Built in light...

  
 It makes a perfect ornament and an even better tree topper, but "She who must be obeyed" quickly put the _*kaibosh*_ to that action. 
	

	
	
		
		

		
			




  
 Oh well, on my desk it will stay...
 One more time, with feeling!
 "Oh Christmas Tube, Oh Christmas Tube, Your glow is sure enticing."


----------



## CollectoR13

What. A. Beautiful. Tube!


----------



## gibosi

Voltage measurements for a 1951 Western Electric 396A (LD 1+)
  
 Plate R 98.1
         L 98.1
  
 Grid   R 1.8
         L 1.7
  
 Interestingly, the plate voltage is quite a bit higher than a 6SN7 (81.2) or a 6N23P (85.2)
  
 And the grid voltage is lower than a 6SN7 (3.2) or a 6N23P (2.6)


----------



## Audiofanboy

Speaking of Christmas - or whichever holiday floats your boat, I don't want any trouble here lol - I got my filtering power strip a bit earlier than I expected, which is good since it'll allow me to familiarize myself with the new sound before I get all those cool tubes in a week.
  
 Same product as - may his soul rest in peace - Acapella11 mentioned months back, this:
 http://www.amazon.co.uk/Tacima-Conditioner-Frequency-Interference-Filter/dp/B000PS5700
  
 Yes, it's cheap; yes, it only has UK sockets (I live in France, use different plugs and still bought it, so it just takes a little creativity); no, I wouldn't use it with non-220-240V AC power; but yes, it makes a COLOSSAL difference!
  
 Honestly, I had expectations that it would at least make a difference with the Little Dot plugged into it - after all, removing noise from power is never bad - but it's rare that a brand new product I add to my sound chain makes a such a difference that at the _very first second_ of listening I'm like "_Oh. I see. And I was missing this all these years, huh? There must have been something wrong with my head... Is this really happening? How can this sound so good? And for £30?!? Holy ****...!!_"
  
 Anyway, I won't go any further since this is largely irrelevant on this thread, but I _strongly urge you_ to get a similar product. It made enough of a difference with just the LD plugged into it, but when I added the DAC to the filtering power strip, it felt like I multiplied the price of my system by 3... You may think I'm joking or overreacting, but you all know I usually don't muck around. The difference is HUGE and makes me wonder just why it took me that long to do something about my power... It feels like I'm listening to a different system right now, and it's better than mine!
  
 Lesson learned: _Filter thine wall power__._


----------



## Audiofanboy

gibosi said:


> Voltage measurements for a 1951 Western Electric 396A (LD 1+)
> 
> Plate R 98.1
> L 98.1
> ...


 
  
 These are pretty close to perfect values actually, right?
  
 That makes me want to try two C3G pentodes, now that we know that the cathode resistor is largely irrelevant - for all intents and purposes.


----------



## mojorisin35

Complete newb question I just received my 6DJ8 converter from mike what setting is my littledot mkiii on ef95 or ef92?


----------



## MIKELAP

mojorisin35 said:


> Complete newb question I just received my 6DJ8 converter from mike what setting is my littledot mkiii on ef95 or ef92?


 
 EF 95 SETTING


----------



## Audiofanboy

mojorisin35 said:


> Complete newb question I just received my 6DJ8 converter from mike what setting is my littledot mkiii on ef95 or ef92?


 
  
 Technically, it shouldn't make a difference since nothing is supposed to be plugged on pin 7 anyway, or pin 6 for that matter... But yes, EF95 would be good practice, on the off chance anything goes wrong.


----------



## Artsi

Merry Christmas!

  
 (And no, i'm not going to use this tube with little dot)


----------



## TrollDragon

artsi said:


> Merry Christmas!
> 
> 
> 
> (And no, i'm not going to use this tube with little dot)


 NICE!
And the same to you and yours!


----------



## MIKELAP

artsi said:


> Merry Christmas!
> 
> 
> (And no, i'm not going to use this tube with little dot)


 
 Thats not really  Santa's little vaccuum tube helper he has a fake beard i can see the string what is this lol ! Merry Christmas everybody !


----------



## CollectoR13

Merry Christmas to you guys!


----------



## sam6350

Hi everyone,
  
 Merry Christmas to all.

 I just have a quick question:

 I ordered these tubes from Yen Audio on Ebay:
  
 http://www.ebay.com/itm/2x-EH-6H30Pi-Matched-Pair-Little-Dot-Amp-Mk-III-IV-SE-/290581469274?pt=Vintage_Electronics_R2&hash=item43a801585a
  
 http://www.ebay.com/itm/290613497027?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649

 I ordered these things on December 9, 2013.
  
 After checking with the postal service, it turned out that the package was rejected by customs and sent back. I live in Toronto, Ontario, Canada.
  
  
 I'm wondering if this has ever happened to anyone?
  
 I can't think of any reason why customs would reject a set of tubes.... or is it probably something that the seller forgot to include on the packaging?
  
 I suppose I'm just wondering if Canadian customs has some sort of policy against vacuum tubes that I'm not aware of 

 Any help would be really appreciated.
  
 Thanks in advance,
  
  
 sam


----------



## MIKELAP

sam6350 said:


> Hi everyone,
> 
> Merry Christmas to all.
> 
> ...


 
 Hey Sam, Merry Christmas i ordered once from Yen Audio and there was no problem with customs im in Montreal .In a way customs did you a favour because if you read the thread youll find out soon enough that you dont have to pay crazy prices for matched pairs because first of all you dont need match pairs for the driver tubes .and if you go to page 77 youll see different tubes that are better than the typical tubes you see on page 1 of the thread for the most parts these tubes start from about $3.00 to around $10.00 approx. So no need to pay a fortune for tubes, not on page 77 anyways .Welcome.


----------



## mordy

Hi Sam6350,
  
 Agree with Mikelap that the customs did you  a favor. First of all, as far as I know you are covered by Ebay's guarantees, and you should not have any problem getting your money back.
  
 Secondly, you can get better and cheaper tubes from other sources. A pair of 6N6P-IR tubes will cost $39.00, and it seems that the consensus on this forum is that these are the best power tubes for the buck.
 If you want the Voskhods you can get the same ones for $14/pair. Another higher recommended tube is the Ei 6HM5 that you can get for $10/pair.
  
 (All prices are from Ebay as of today, and include shipping)
  
 There are a number of Canadian members on this forum, and except complaints on long delivery times I did not hear that packages were returned by customs.
  
 Good luck!


----------



## sam6350

Mike and Mordy,
  
 Thanks alot for the help. I'm a bit of a noob to tube rolling.
  
 Just to follow up.

 I'm using a Littledot MkIII amp, so I'm assuming that these tubes will be ok for that amp?

 Also, I'm assuming that these are what you're referring to Mordy?

 http://www.ebay.ca/itm/6HM5-6HA5-EC900-export-quality-audio-triode-tube-NOS-FREE-SHIPPING-/300879467071?pt=Vintage_Electronics_R2&hash=item460dd0523f
  
 http://www.ebay.ca/itm/3-x-6N6P-IR-Russian-dual-triode-NOS-/161172634461?pt=LH_DefaultDomain_0&hash=item2586a33b5d
  
  
 Lastly, is this the same thing as a 6N6P-IR? or does that "IR" make a big difference?

 http://www.thetubestore.com/Tubes/Russian-Tubes/Russian-6N6p-6H6pi

  
 Thank you guys again for all the great advice,
  
 Sam


----------



## gibosi

I have been listening to a 1951 National Union 6SN7GT recently, and I must say, this is one very fine tube.
  


Spoiler: Tube pic






  
 As Mordy observed in a private message, 6DJ8-type tubes are cooler and more detailed and the octals are warmer and more musical, and I think this hits the nail directly on the head. If you begin to roll 6SL7s and 6SN7s after having lived in 6DJ8 land for a while, you will definitely notice this difference.
  
 Of course, too much reverberation thickens the sound and obscures detail, but the National Union seems to get it just right. A touch more reverberation creates a very large and spacious 3D stage with considerable depth. Vocals are slightly forward and warm without losing mid range detail. Moreover the bass and treble are very good. While the National Union lacks the ultra detail of the premium 6DJ8, in my opinion, it makes up for it in musicality. Don't get me wrong, I still enjoy listening to my best 6DJ8s with their amazing detail, but the musicality of the 6SN7, done right, as evidenced by the National Union, is very enjoyable too.
  
 Frankly, I was not impressed with the 5751/12AX7 or the 6SL7 tubes, but judging from my experience with the National Union, 6SN7 tubes are definitely worth exploring further. I gave $20 for this tube, including shipping, so not cheap, but not outrageous either.
  
 With the caveat that this is a 600ma tube and an external heater circuit is required, strongly recommended.


----------



## mordy

Hi Sam 6350,
  
 The first link is the right one for the Ei tubes. Although he asks $6.95 a tube, he accepted $5 from me and maybe $4 from someone else on this forum on Best Offer.
  
 The second link is also the right one. I got my tubes from this seller who is very nice to deal with. The price is good. If you want to save money, ask how much he will charge you for 2 tubes since this offer is for three tubes.
  
 The there is a very big difference between 6N6Pi tubes and 6N6P-IR tubes. If you do a search on this blog you will find a comparison between some  Little Dot MKIII driver tubes on page 183 post #2745.


----------



## gibosi

sam6350 said:


> I'm using a Littledot MkIII amp, so I'm assuming that these tubes will be ok for that amp?
> 
> Also, I'm assuming that these are what you're referring to Mordy?
> 
> http://www.ebay.ca/itm/6HM5-6HA5-EC900-export-quality-audio-triode-tube-NOS-FREE-SHIPPING-/300879467071?pt=Vintage_Electronics_R2&hash=item460dd0523f


 
  
 Yes, those 6HM5s are the right tubes, made in Yugoslavia. And yes, they will work great in your LDIII. Just set your amp to use EF95 tubes and you are good to go. As I use an LD 1+, I can't comment on the 6N6P....


----------



## sam6350

Thank you again guys,
  
 Just as an update, I called the postal service again and now they're telling me that it wasn't rejected and sent back... which makes me think that someone in the bureaucracy made a mistake. I'll know for certain on Friday as to what the heck is going on. If the Tubes I already ordered are on their way, then I'm obliged to pay for them (obviously).
  
 Regardless, I may just order the tubes you guys have recommended anyway, and then start doing my own comparisons.

 Merry Christmas, and once again, thanks alot.
  
 All the best,
  
 Sam


----------



## MIKELAP

Merry Christmas everybody !


----------



## Nic Rhodes

He will accept $5 but not $4 on the Yugo tube (even for a large number).


----------



## gibosi

ctritical bill said:


> Heater         Plate         Cathode
> 
> Westinghouse  (L) 6.38v           147.8v         1.052v
> (R)                   147.1v         1.067v
> ...


 
  
 I made some measurements with a Tung-Sol 6SU7GTY and a Sylvania "Chrome Top" 6SL7WGT  in an LD 1+:
  
 DC heater set at 6.3:

                            Plate                   Cathode/Grid
  
  Tung Sol              R  104.6                    1.1
                             L  104.7                    1.1
  


Spoiler: Tung Sol






 
 Sylvania                R  105.1                     1.0
                             L  105.1                      1.1
  


Spoiler: Sylvania











  
 While the cathode/grid values are very similar to yours, it is interesting that the plate values are significantly lower. Perhaps because the tube stage in the LD 1+ is configured as a cathode follower rather than a "driver"?


----------



## gibosi

I received a Raytheon 6CG7 this morning, made in the US, with black plates. Searching Google, the Raytheon (US made, not Japan) seems to have a very good reputation. The 6CG7 is electrically identical to the 6SN7, (and most importantly to those of with LDs, it requires 600ma, so an external heater is advisable), but it is pin-compatible with the 6DJ8.
  
 Took some measurements
  
 DC heater voltage set to 6.3, but read 6.16 at the socket
  
           Plate           Grid/Cathode
 R          82.8                 3.1
 L          82.8                 3.1
  
 Not surprisingly, roughly the same readings as a 6SN7.


----------



## i luvmusic 2

merry christmas,hi i would like to know if all the tubes that are listed in page 77 and all the current tubes that you guys are rolling will  work with LD 1+?THANKS


----------



## gibosi

i luvmusic 2 said:


> merry christmas,hi i would like to know if all the tubes that are listed in page 77 and all the current tubes that you guys are rolling will  work with LD 1+?THANKS


 
  
 Yes, I have an LD 1+ and I am pretty sure I have used every one of these tubes. 
  
 Cheers


----------



## MIKELAP

Ive been waiting so long for my 6SL7 OCTAL to 12AX7 adapters  still not here after 5 weeks so started to do an adapter for 6SL7 octals only, do any of you guys know if some of these  6SL7 to 12ax7 adapters are made and sold in the U.S. . Thanks


----------



## i luvmusic 2

gibosi said:


> Yes, I have an LD 1+ and I am pretty sure I have used every one of these tubes.
> 
> Cheers


 
 THANK YOU! and do you have any recomendations for the OP amp?


----------



## gibosi

i luvmusic 2 said:


> THANK YOU! and do you have any recomendations for the OP amp?


 
  
 The best op amp I have found so far is the MUSES 02.


----------



## gibosi

mikelap said:


> Ive been waiting so long for my 6SL7 OCTAL to 12AX7 adapters  still not here after 5 weeks so started to do an adapter for 6SL7 octals only, do any of you guys know if some of these  6SL7 to 12ax7 adapters are made and sold in the U.S. . Thanks


 
  
 I haven't been able to find one made in North America, only China or HK. That said, 5 weeks seems a very, very long time.....


----------



## TrollDragon

mikelap said:


> Ive been waiting so long for my 6SL7 OCTAL to 12AX7 adapters  still not here after 5 weeks so started to do an adapter for 6SL7 octals only, do any of you guys know if some of these  6SL7 to 12ax7 adapters are made and sold in the U.S. . Thanks


 
Orlando FLA... $25 each and $9.95 shipping to Canada Eh?
 They can also make you what you want if you contact them.
  
 This will allow you to plug your 6SL7 into your 6DJ8 adapter, 6SN7=6SL7 & 6CG7=6DJ8 as far as pinouts are concerned.
 This adapter will *NOT* work in your 12AX7 adapter.


----------



## mordy

HI TD,
  
  
 I have an octal to 12AX7 adapter which is plugged into a 9 pin socket on a breadboard which is wired to play 12AX7 tubes via two Vector adapters. With this adapter I play 6SL7 tubes. Are you saying I that I cannot use this set up for 6SN7 tubes? (I realize that the 6SN7 tubes need a separate power supply for the heaters).


----------



## gibosi

mordy said:


> I have an octal to 12AX7 adapter which is plugged into a 9 pin socket on a breadboard which is wired to play 12AX7 tubes via two Vector adapters. With this adapter I play 6SL7 tubes. Are you saying I that I cannot use this set up for 6SN7 tubes? (I realize that the 6SN7 tubes need a separate power supply for the heaters).


 
  
 You can continue to use your current arrangement for both 6SL7 and 6SN7 tubes. They have the exact same pin out. Similarly, I configure my 9-pin socket for 12AX7 tubes and use a Chinese adapter to run Octals. However, the adapter TrollDragon found will allow one to run 6SL7 and 6SN7 tubes in a 6DJ8 socket! For me, this would be much better. The ONLY reason I configure my socket for 12AX7 is to run Octals. If I never had to change from the 6DJ8 configuration again, that would be great.


----------



## kvtaco17

Got tired of ugly wires...


----------



## gibosi

Received a few 8CG7 today. The one on the left appears to be an older RCA with a side D-getter, even though it has the "Micro" label. I think the one in the middle is Japanese, and the one on the right is dated 7022 Japan, so no doubt about that. None of these have a shield. That is, pin 9 is not connected to anything. Evidently, some of these *CG7 tubes have shields and some don't. Those with shields are often described as having "3 Plates" by vendors. My Raytheon 6CG7, which sounds extremely good by the way, does have a shield.
  
 Anyway, I dialed in 8.4 volts, fired them up and they all light up and play. I only paid about $7.00 for these as I just wanted an excuse to adjust my DC heater voltage. lol  Will spend a little more time with them, but don't expect much.


----------



## mordy

Hi All,
  
 At the present time I am exploring different 6SL7 tubes. However, first I want to say that I have been listening to a bunch of tubes from the 6DJ8 family, mainly different brands of 6BC8/6BZ8, 6BZ7 and 6N23P tubes. The amazing thing is that all of them are very good, with the trademark etched detailing of sound, wide sound stage and good bass and treble. The only con is that they are a little cold and analytical, but not in an irritating way; just the way they are, in a pleasant "intellectual" way. These variants probably offer almost all of the sound of the very expensive Amperex tubes at a fraction of the price.
  
 Now back to the 6SL7 tubes: In contrast to the 6DJ8 family these tubes are warm and musical. Some of them lack in the detail but it is made up by the musicality and heft in the bass that can go very low with some of these tubes. My favorite right now is this 6SL7GT Tung Sol tube from July 1967:

  

  
 This tube has a very sweet, warm sound, excellent imaging with great bass and mid range. What stands out is a fat mid bass. The treble is not sizzling, but still very good and satisfying. The slam and attack is lesser and slower than the 6BC8 tubes, but as said before, this tube makes it up with it's musicality.
  
 The tube is shown in action mounted to a breadboard wired for a 12AX7 tube with an octal adapter. The multi colored wires come from a discarded computer power supply.
  
 I realize that some people on this forum are intimidated by the thought of making up adapters to fit tubes that were not originally intended for the Little Dot amps. Personally, I was myself very hesitant to fiddle with the electronic stuff since I do not have any background in this. However, once you decide to try it is not that difficult, especially with the excellent wiring diagrams provided by the esteemed members of this thread.
  
 If there is an interest, I would show in pictures how to put together an adapter using a 9 pin breadboard socket and Vector adapters for those who are new to tube rolling and want to use non native tubes in the Little Dot MKIII amp. As I learned through Gibosi, this can be done without the use of a soldering iron.
  
 Happy tube rolling and listening!


----------



## i luvmusic 2

gibosi said:


> The best op amp I have found so far is the MUSES 02.


 
 THANK YOU!
 can't wait for my LD 1 i just ordered it yesterday when it arrive i may do some octal tube rolling if i have the guts and know how...


----------



## MIKELAP

Well another milestone  weve just it page 300 time flies !


----------



## Audiofanboy

mordy said:


> I realize that some people on this forum are intimidated by the thought of making up adapters to fit tubes that were not originally intended for the Little Dot amps. Personally, I was myself very hesitant to fiddle with the electronic stuff since I do not have any background in this. However, once you decide to try it is not that difficult, especially with the excellent wiring diagrams provided by the esteemed members of this thread.
> If there is an interest, I would show in pictures how to put together an adapter using a 9 pin breadboard socket and Vector adapters for those who are new to tube rolling and want to use non native tubes in the Little Dot MKIII amp. As I learned through Gibosi, this can be done without the use of a soldering iron.


 
  
 Indeed, it would just be too much of a shame for people not to try the 6DJ8 (and other) types just because they're afraid of making/crafting an adapter. It really isn't that hard once you get the diagrams down, and you've got metric tons of help here on this thread, so _go for it_ and roll yourself some double triodes this Christmas, or whatever holiday you prefer!





  
 Page 300 huh? Wow, it was like page 30 something the first time I posted here... Time flies when you having fun lol.


----------



## i luvmusic 2

mordy said:


> Hi All,
> 
> At the present time I am exploring different 6SL7 tubes. However, first I want to say that I have been listening to a bunch of tubes from the 6DJ8 family, mainly different brands of 6BC8/6BZ8, 6BZ7 and 6N23P tubes. The amazing thing is that all of them are very good, with the trademark etched detailing of sound, wide sound stage and good bass and treble. The only con is that they are a little cold and analytical, but not in an irritating way; just the way they are, in a pleasant "intellectual" way. These variants probably offer almost all of the sound of the very expensive Amperex tubes at a fraction of the price.
> 
> ...


 
 Hi, i am interested in making the adaptor(for the tube in the picture) please let me know what are the materials  i need and if you can show the diagram i have the VECTOR 7 Pin adaptor. Thanks!


----------



## MIKELAP

Speaking of adapters i started to put together an adaptor for octal tubes since my chinese adapters are probably lost ,using  Troll Dragon's  design and Artsi's schematics here's the  12AX7 an 6DJ8 adapters i made heres a few pictures the 6SL7 octal adapter is more elaborate since theres cutting and soldering i would say just for the chassis i will probably put in a couple hours since i have to open up the diameter where the octal socket goes in the tube .as for the rest the parts used will be like the other adapters


----------



## i luvmusic 2

mikelap said:


> Speaking of adapters i started to put together an adaptor for octal tubes since my chinese adapters are probably lost ,using  Troll Dragon's  design and Artsi's schematics here's the  12AX7 an 6DJ8 adapters i made heres a few pictures the 6SL7 octal adapter is more elaborate since theres cutting and soldering i would say just for the chassis i will probably put in a couple hours since i have to open up the diameter where the octal socket goes in the tube .as for the rest the parts used will be like the other adapters


 
  


mikelap said:


> Speaking of adapters i started to put together an adaptor for octal tubes since my chinese adapters are probably lost ,using  Troll Dragon's  design and Artsi's schematics here's the  12AX7 an 6DJ8 adapters i made heres a few pictures the 6SL7 octal adapter is more elaborate since theres cutting and soldering i would say just for the chassis i will probably put in a couple hours since i have to open up the diameter where the octal socket goes in the tube .as for the rest the parts used will be like the other adapters


 
 That is nice, what gauge is that wire you are using(solid and the stranded)?


----------



## MIKELAP

i luvmusic 2 said:


> That is nice, what gauge is that wire you are using(solid and the stranded)?


 
 22 gauge stranded copper wire for the connections and 1 m.m.(.039) copper wire for the pins


----------



## i luvmusic 2

mikelap said:


> 22 gauge stranded copper wire for the connections and 1 m.m.(.039) copper wire for the pins


 
 THANK YOU!


----------



## TrollDragon

mikelap said:


> Speaking of adapters i started to put together an adaptor for octal tubes since my chinese adapters are probably lost ,using  Troll Dragon's  design and Artsi's schematics here's the  12AX7 an 6DJ8 adapters i made heres a few pictures the 6SL7 octal adapter is more elaborate since theres cutting and soldering i would say just for the chassis i will probably put in a couple hours since i have to open up the diameter where the octal socket goes in the tube .as for the rest the parts used will be like the other adapters.


 
  
 Nice Job on those adapters!


----------



## gibosi

My late 1950 (or early 1960) US-made Raytheon 6CG7 with black plates is fast becoming one of my favorite tubes. It is slightly warmer than the Amperex and Voshkod 6DJ8-types, with excellent liquidity and flow, and a spacious 3D stage with very good depth and detail. But what really separates this tube from the 6DJ8 is the midrange. Vocals are slightly forward and crystal clear, but never stridant, and as a result, I am hearing more mid-range detail with this tube than with the 6DJ8. Highly recommended.
  
 In the second photo, you can clearly see the shield in between the two triode plates. Some vendors describe such a 6CG7 as having three plates. Also, this tube is taller than a standard 6DJ8.


----------



## kvtaco17

I got my DC regulator all wired up and tucked safely inside my enclosure, the little bit of hum I had is now 100% gone... makes these tubes seem more dynamic (Amperex A frames) probably due to having a completely black image on quieter passages... now I just have to figure out how to mount the DC regulator and cut holes so it is accessible/visible from the front.


----------



## mordy

Hi kvtaco 17,
  
 When you figured out how to mount it, could you please post pictures -thanks


----------



## kvtaco17

mordy said:


> Hi kvtaco 17,
> 
> When you figured out how to mount it, could you please post pictures -thanks


 
 Oh I will! I have a few Ideas, the problem is how I want to go about the cutting...


----------



## gibosi

In today's mail, a 1952 Tung Sol 6SN7GT "Mouse Ears" arrived. This tube has two round mica spacers attached to the rectangular top mica and making contact with the glass on each side (“Mouse Ears”). This tube has a good reputation in the 6SN7 community and isn't all that expensive. I gave about $15 with shipping for this one.


----------



## mordy

Here is my present favorite tube - a 6SL7GT Tung Sol tube from 07/57. After cooking for three days straight (don't worry, barely gets warm) it produces bone rattling bass when called upon, and a clear warm detailed musical presentation with a an excellent sound stage. So what's the problem? I can't get myself to remove it and try other tubes that are waiting to burnt in. It's  so nice and engaging that I am just enjoying listening to music and not to the tubes. Yes, i am taking a break.....
  
  
  
  

  
 Gibosi was kind enough to send me a link to a great and exhaustive write up about 6SN7 tubes. Some of the things said stated there apply to all NOS tubes and made me change my mind on which tubes are desirable or not.
  
 http://www.head-fi.org/t/117677/the-reference-6sn7-thread
  
 Even though it is a lot to read, take the time to peruse it - it is worth it!
  
 On another note, I went through about 75% of my write up on how to make adapters, with many pictures, descriptions etc. Then my computer crashed (something that does not happen usually) and I lost everything. Seems that there is a problem with the Editor window. Would appreciate if somebody has a tip on writing a post without losing it, which has happened a
 few times to me.


----------



## gibosi

mordy said:


> On another note, I went through about 75% of my write up on how to make adapters, with many pictures, descriptions etc. Then my computer crashed (something that does not happen usually) and I lost everything. Seems that there is a problem with the Editor window. Would appreciate if somebody has a tip on writing a post without losing it, which has happened a
> few times to me.


 
  
 I have had Head-fi's Editor window freeze on me more than once...... So now, if I plan to write more than just a few lines, I usually compose in Windows Notepad, and when it is ready to go, I then copy and paste into the Head-fi Editor and submit. Cheers.


----------



## TrollDragon

Same here with a notepad to web editor posting, I have done that for years and it is a good practice to get into.

Unlike other forums, HF does not save drafts. I was making a post on Icrontic, had quite a few browser windows open when the power blipped and the box reset. Rebooted, went back to Icrontic and hit the draft tab. There was my post all ready to go so I just hit submit.


----------



## mordy

Hi TD,
  
 I don't quite understand what I should do not to lose my information - could you give more details - thanks.


----------



## mordy

*HOW TO MAKE A SOLDERLESS TUBE ADAPTER FOR LITTLE DOT AMPS:*  
  
  
 OK, so here are the instructions for making an adapter to use tubes not originally intended for the Little Dot amps. First we need a breadboard:





 Oops, this is not a cooking show! (Could not resist a joke to put you in a good mood to tackle this task) . We need an ELECTRONIC breadboard:
 It looks like this:




 As you can see, it has 18 screw terminals numbered 1 to 9. Each number on the board corresponds to one pin of the 9 pin tube, and the screw terminals allow you to connect two wires to each pin. Usually you only need one wire. A small flat blade screw driver is all that is needed. The board pictured here costs $24.00 and is US made. Look for
http://www.ebay.com/itm/9-pin-breadboard-prototype-tube-socket-for-DIY-experimenting-/151176364267?pt=Vintage_Electronics_R2&hash=item2332d040eb 
 
  


 
  


 
  


 

 ​
 
  
 There are other boards available for $7.00 to 15.00. For some reason availability varies, but the cheaper Chinese ones are well made.




 This one sells for $15. The one below is Chinese and cost $7.00 but I do not see it on US Ebay right now. Available on European Ebay sites (for more money).






 This model requires you to solder in little wires to connect the two little holes that are intended for resistors. Look for
1SET 9pin B9A tube test diy Experiment prototyping pcb for EL84 ECC83 12AX7 ECC8 Next you need two Vector adapters. The best price I have found is from Radiodaze ($5.00 each + shipping approximately $6.00):




http://www.radiodaze.com/vgm_search_result.aspx
 Next you need stranded wire 22 AWG. The thickness of the wire is determined by what fits into the hole on the Vector tabs. I scavenged wires from a discarded PC power supply, but most anything will do, but do not use solid wire. At first I used very thin solid 30AWG wire wrap wire, but it had two disadvantages: It was too thin and broke off, and the insulation was also too thin, making it susceptible to electro-magnetic interference. Solid wire is less pliable and will make it difficult to close the Vector adapter.
 You need something to strip the wires with, a wire stripper, cutting pliers, scissors or whatever.  9-10 " long pieces of wire is more than enough (need 9 pieces). The end for the breadboard screw terminal should be stripped approximately 2/16 "; the other end for the Vector about 3/8".
 The Vectors are clever little devices, but can be very pesky. There is a threaded screw with a nut that goes through the adapter and holds it together. You need to take this screw out to work with the adapter. The nut on the bottom is tiny - make sure that your work surface does not make it disappear when it falls out, which it will. -Just thought of it; a little piece of tape will hold it in place so that you don't lose it.
  
 AFTER TAKING OUT THE SCREW DO NOT SEPARATE THE ADAPTER INTO TWO PIECES!!! It will be extremely difficult to put it together. Just pull it apart a little. Use a little rubber band to prevent the pins from pulling out of the bottom piece.
  

  

  
 As you can see, the tabs are numbered 1 to 7. Each tab is bent at a right angle, and the tab has a hole in it. Now carefully thread your wire through the appropriate hole. A small needle nose pliers will help. Twist together the end of the wire with the rest of the wire.

  
 After the wiring is done, the adapter is pressed together, and the screw with a tiny lock washer on top is inserted from the top. The nut is held in place by a cutout. Tighten gently; overtightening can break the adapter. Believe it or not, this pressure fit of the wires gives better contact than soldering the wires. Make sure that no strands of wire can come into contact with an adjacent wire.
  

  
 Insert the corresponding wires into the breadboard and tighten with a small flat blade screwdriver. It may be easier to do one wire at a time and do both ends before pressing together the adapter. After tightening all screws and connections, test all connections by pulling on them. Recheck that all the wires go to the proper places using the diagrams on pages 252, 253 and 275. There are three variations depending on which tube type you use.
  

  

  

  
 You may want to put on something on the bottom of the bread board to keep the solder points touching the surface you are putting it on. There are four holes in the breadboard where you could put in screws with nuts to lift it off the surface. I used a little piece of self stick foam i found, maybe from a piece of door insulation.

  
 The last two pictures show the screw and nut.

  

  
 Here is wiring diagram for a 12AX7 tube:
 12AX7
  
 9-pin socket           left LD socket        right LD socket
  
 1 plate triode 1                5                        
 2 grid triode 1                  1
 3 cathode triode 1            2
 4 heater                                                    3                         
 5 heater                                                    3                         
 6 plate triode 2                                           5
 7 grid triode 2                                             1
 8 cathode triode 2                                       2
 9                                                              4
  
 Just look for screw terminal 1 on the breadboard and connect the wire to the left Vector #5 etc etc. Once you are finished it does not matter which side of the Little Dot amp you plug in the adapters. Right and left are only for the purposes of routing the the correct wires.
  
 Here is the diagram for 6DJ8 tubes:
  
 9 Pin socket                                 Left LD socket                    Right LD socket
  
 1 plate triode 1                                     5
 2 grid triode   1                                     1
 3 cathode triode 1                                 2
 4 heater                                                                                           3
 5 heater                                                                                           4
 6 plate triode 2                                                                                 5
 7 grid triode 2                                                                                   1
 8 cathode triode 2                                                                             2
9 Shield tied to pin 8 at the socket (Use short wire to connect terminals 8&9 together on the breadboard only.)
  
 As you can see, the changes from 12AX7 to 6DJ8 only involve one of the adapters. If you want to change the wiring, only do it at the breadboard terminals; leave the adapter connections where they are.
  
 With the 12AX7 setup you can buy a plug in adapter to play octal 6SL7 and 6SN7 tubes. The 6SN7 draws more current than the Little Dot can handle, so you will need an external power adapter such as an old laptop adapter and a voltage regulator.
  
 I have tried to be very thorough in showing how to build an adapter and how easy it really is when you have the right parts. This is a first draft, and there may be errors and omissions. Please submit your comments and suggestions on how to improve this post.
  
 Many thanks to AFB for coming up with the original flying tube adapter and to Gibosi for posting the diagrams and overall guidance, and to all others who have contributed and helped to enhance the Little Dot listening experience.
  
 Happy tube rolling!


----------



## TrollDragon

Hey mordy!
  
 What I do is compose any long writeup that is to be posted on the web in either MS Word or OpenOffice Writer. In each program you would have autosave turned on so all you would really loose is 5 minutes of composing or editing if anything went wrong.
  
 I have all my pictures named, sized and in one folder for upload after all the text is written. I just put In placeholders for the pictures like _*[lcd3_side_view.jpg]*_. Then after everything has been written and spell / grammar checked I copy all the text and paste it into the post editor of whichever site I am uploading it to. I do all text formatting in the post editor on the site, if you do it in Word most formatting will not look correct or translate properly on the web site. I replace all the picture placeholders with the images that I have uploaded, a little fine tuning and hit the preview button. If all looks good then submit your post and all should be good, you can always go back and edit it if someone picks up on and errors... 
	

	
	
		
		

		
		
	


	



  
 For example here is my Impression writeup I did for the Burson Conductor SL and Audeze LCD-3's I had on loan for three weeks.
 http://trolldragon.wordpress.com/2013/12/01/top-of-the-line-impressions/
  
 All text was composed in MS Word then copied and pasted to the Wordpress entry editor, fine tuned, pictures linked and voila a blog entry was made. Now recreating the same layout here on Head-Fi was a real *PiTA* as Head-Fi's editor is severely feature crippled compared to the Wordpress one. This is understandable because on a forum security against hacks is a priority.
  
 The Draft function I was talking about is a feature of another forum I visit on a regular basis.


----------



## MIKELAP

If somebody wants to roll 12ax7 type tubes i have a spare adapter PM me if interested .


----------



## hypnos1

audiofanboy said:


> Speaking of Christmas - or whichever holiday floats your boat, I don't want any trouble here lol - I got my filtering power strip a bit earlier than I expected, which is good since it'll allow me to familiarize myself with the new sound before I get all those cool tubes in a week.
> 
> Same product as - may his soul rest in peace - Acapella11 mentioned months back, this:
> http://www.amazon.co.uk/Tacima-Conditioner-Frequency-Interference-Filter/dp/B000PS5700
> ...


 
  
  


audiofanboy said:


> These are pretty close to perfect values actually, right?
> 
> That makes me want to try two C3G pentodes, now that we know that the cathode resistor is largely irrelevant - for all intents and purposes.


 
  
 Hi AFB.
  
 I certainly second your recommendation re. mains filter/conditioning...I would have said _essential..._and shame on you for not having 'cleaned up' sooner!! And don't neglect the individual equipment power leads either, folks - upgrade 'em. And when funds are flowing, get rid of those cruddy fuses and pop in some nice (gold-plated?) ones - go on, treat yourselves...just don't tell 'er indoors!
  
  
 Have been drooling over Yamamoto equipment for a while now, and did like the look of the Siemens C3ms in his HA03 amp. So the 6.3V C3gs have been quietly beckoning - your interest (along with the glowing report in JAC Music) has encouraged me to bite the bullet and splash out. So you might just be partly to blame for emptying my wallet somewhat, but hopefully NOT to no avail!
  
 For some reason I have this strange feeling that they _might_ just provide the 'missing link' in my Tesla E88CCs, which at present are undefeated - given my equipment and ears/preferences - even by the likes of TFK ECC88s; Mullard E88CCs (gold pins); RCA (Amperex) 6DJ8s; Voskhod 6N23Ps ('78s, courtesy of Gibosi, and matched '73 & '74 pair), etc. etc.
 The Philips group and Russians give slightly more bass slam and mid presence (even more so with the TFKs), but they are not matching the Teslas' fabulous clarity, separation, soundstage,  detail and 3-dimensionality that just gives me that 'wrap around the head' magic...for me, anyway...Another plus is that because everything is so "clean", if I want more bass all I have to do is crank up the volume, without having to wince.
  
 So _perhaps_ the C3gs _might _just provide the extras, without affecting all those other qualities I have come to love in the Teslas...time will tell...
 (It does however seem strange to be going back to pentodes, after all we have been doing for some time now! But if it's good enough for Yamamoto........)
  
 Cheers everyone, and a HAPPY NEW YEAR to you all.


----------



## Artsi

Long time no seen.
  
 Here i can show how my Russian tubes have advanced.

 First there is 6ZH1P, second 6N2P, third 6N8S and last but not least 6N13S. Last one is not very compatible with little dot's so i made bigger adapter for it. (read whole amp)
  
 Haven't had time to listen little dot for days. Building these DIY amps have kept me busy. Do not know where do i need power what two 6AS7/6080 as powertubes will deliver, but at least building amps have been fun. And when you know all the parts inside your amp, then you can try to do improvements to it. At least i have something always in my mind and i need to open my DIY amp and solder more parts.
  
 I wish you all *happy new year* and have fun with tube rolling.


----------



## i luvmusic 2

Hi i just received my LD 1+ and i have a problem with it all tubes that i tried they HUM i mean all tubes EF91 Ef92 and EF95 they all hum except the tube that come with it which is 6J1.that 6J1 is dead quiet even in high gain with those EF91 EF92 and EF95 in high gain they hum loud.


----------



## gibosi

audiofanboy said:


> Honestly, I had expectations that it would at least make a difference with the Little Dot plugged into it - after all, removing noise from power is never bad - but it's rare that a brand new product I add to my sound chain makes a such a difference that at the _very first second_ of listening I'm like "_Oh. I see. And I was missing this all these years, huh? There must have been something wrong with my head... Is this really happening? How can this sound so good? And for £30?!? Holy ****...!!_"


 
  
 £30 is quite reasonable, but unfortunately, this filtering power strip is not designed for use in the US. Does anyone have a recommendation for a similarly-priced unit suitable for 120 volt mains?


----------



## MIKELAP

gibosi said:


> £30 is quite reasonable, but unfortunately, this filtering power strip is not designed for use in the US. Does anyone have a recommendation for a similarly-priced unit suitable for 120 volt mains?


 
 When Audiofanboy purchased is power bar i checked around a bit for something similar didnt find anything is that price range the cheapest i found was around $270.00 and it went into the thousands 
 this EMI FILTER   http://www.partsconnexion.com/prod_pdf/ftech_76110.pdf


----------



## mordy

Hi Artsi,
  
 Is the 6N13s similar to the 6080 tube which is used in the LD MK9 ?


----------



## Artsi

mordy said:


> Hi Artsi,
> 
> Is the 6N13s similar to the 6080 tube which is used in the LD MK9 ?


 
 Yes 6N13S (6H13C) should be similar to 6080 or 6AS7. LD MK9 uses only one 6SL7 as driver. I have pair of Philips ECG 6080WC USA tubes too.
  
 Since this is little dot thread here is size comparison between DIY monster and LD MK II. (furball on the background is my cat)

 Originally i chose MK II since it was very small all tube amp. And look at this, now i have this monster on my desk with 5.2kg transformer. And i know that this DIY amp is still very small in two 6AS7/6080 class and it uses push-pull structure.
  
 I can use 6SN7 to 6AS7 as powertubes and 6SL7 and 6SN7 as drivers. ECC32 should work too as driver, but they are far too expensive. Power consumption of amp is around 88w with 6080's and 6SN7's. So now i can use my precious 6SU7GTY's. With -73 6N13S's i received four -65 6N8S with square getter. So far they sound very good. I think this model should be the best of non-metal base 6N8S's. http://www.ebay.co.uk/itm/251379277920


----------



## gibosi

Received a nice assortment of 6CG7 yesterday:
  
 Sylvania on the left and an RCA on the right
  

  
 And two Tung Sol, both have D-getters, but as you can see there are some differences. The tube with gray plates has a third mica just under the getter and the glass is slightly pinched at the base.
  

  
 I spent a little time with the gray Tung Sol last night, and it is a very nice tube. As the 6CG7 is essentially a 6SN7 in a miniature 9-pin format, it has a very spacious sound stage and warm, musical presentation characteristic of these tubes.
  
 I paid less than $6 a tube so these are generally very affordable. But again, as these are 600ma tubes, an external heater circuit is recommended. Also of importance to some, these have less gain than the 6DJ8, that is, the volume needs to be turned up a bit higher.


----------



## TrollDragon

artsi said:


> Since this is little dot thread here is size comparison between DIY monster and LD MK II. (furball on the background is my cat)
> 
> Originally i chose MK II since it was very small all tube amp. And look at this, now i have this monster on my desk with 5.2kg transformer. And i know that this DIY amp is still very small in two 6AS7/6080 class and it uses push-pull structure.


 
 Bravo!
 Excellent work, it is really great to see a project start out as a few rolled tubes and turn into a full blown amp!
  
 Now you will just need to incorporate 42 of the 6AS7G's with a dozen 6SN7's as drivers like the *Atma-Sphere MA-3* does and that is per channel...


----------



## CollectoR13

Hello again guys! 

I am concerned in my move to put 6cg7 to 6sn7 adapters in place of power tubes. 
I didn't receive them yet, but I read that I need a seperate power supply to run 6sn7's.
Is that right or does it only apply for driver tube section? 
I'm afraid that I can't use the adapters plug and play...
(BTW, do 12ax7 tubes have more potential than yugo 6hm5's?) 

And happy new year to you!


----------



## MIKELAP

Received some Octals today Sylvania and Tung-Sol 6SL7GT ,VT-229 , 6SU7GTY and JAN CHS 6SL7 GT. nice warm sounding tube good bass


----------



## mordy

Hi Mikelap,
  
 Agree with you that the 6SL7 tubes are nice and warm sounding with good bass. So much so that I would say that this is the "house" sound of these type of tubes, in addition to a very wide sound stage. This sound quality becomes even more noticeable when you come from 6DJ8 type tubes which are more analytical and colder sounding, although the 6DJ8 tubes have a special place as well with all the wonderful detail and pinpoint imaging. Just two different personalities.
  
 Looks like you got some 'oldies but goodies' as well. In the first picture it seems to me that the right Tung Sol tube is from March 1941. The VT designation is an army book keeping designation. From what I read it was in use up til 1945-47 after which the VT designation was discontinued. Therefore a tube that says VT is an assurance that it is quite old.
  
 Looks like you will be busy for a while comparing these tubes. Let us know which one sounds the best!
  
 Happy tube rolling!


----------



## mordy

Hi CollectoR13,
  
 The 6CG7 and 6SN7 tubes have a higher current draw than the Little Dot was designed for. As driver tubes they need a separate power supply. Can't remember if this applies to using them as power tubes since the power tubes draw more current than the driver tubes. (I think it applies there as well).
  
 Can somebody clarify this?
  
 As to the 12AX7 tubes, I only found one that I like, an early 60's Sylvania. The 6DJ8 family seems to be a better choice. In addition, the electric guitar people who use tube amps seem to favor the 12AX7 type tubes, and the prices are high for premium tubes.
  
 The 12AX7 variants have more potential than the 6HM5 Yugos. However, if you want plug and play, the Yugo tubes are among the top choices. The other tubes mentioned above are better, but all require modifications.
  
 If you look through the posts on this forum, you will find easy ways to add an external power supply. A voltage regulator with a digital readout can be bought for less than $5.00, and you may have a power adapter  lying around the house (inexpensive ones are available). Personally, I am still waiting for my voltage regulator to arrive from China - should be here in a few days.
  
 Good luck!


----------



## mordy

HI TD,
  
 The Atma Sphere MA3 is not that much different than the LD MKIII. The Atma weighs 464 lbs, puts out 500W and costs a little less than $150.000.00. As a bonus, if one of the 54 tubes stop working, you won't notice.


----------



## TrollDragon

Yeah mordy it is quite the beastie!
Built in tube tester as well and you can switch out banks of tubes.


----------



## MIKELAP

Late delivery today a pair of G.E. JLRV 5814A   very nice sound wide soundstage 3d imaging  like them alot.


----------



## mordy

Hi Mikelap,
  
 Is this tube similar to a 6.3V 12AU7 tube?


----------



## MIKELAP

mordy said:


> Hi Mikelap,
> 
> Is this tube similar to a 6.3V 12AU7 tube?


 
 The 12AU7 and the 5814A are a 12V tube type  i use my 12AX7 adapter to run these.


----------



## i luvmusic 2

I just want to say HAPPY NEW YEAR to all!


----------



## i luvmusic 2

i luvmusic 2 said:


> THANK YOU!


 
 Hi MIKELAP,
   Me i asked where did you get the 1mm copper wire for the pins?I can't find them.THANK!
 OOPS i just qouted my self.


----------



## MIKELAP

i luvmusic 2 said:


> Hi MIKELAP,
> Me i asked where did you get the 1mm copper wire for the pins?I can't find them.THANK!
> OOPS i just qouted my self.


 
 In a arts and craft store you could also use big steel paper clips they measure 1mm but you have to measure them to make shure .also if you have coax cable for t.v. i had an old one and the copper cable inside measured 1mm on the other hand the newer cable the copper wire is smaller and if you are wondering how to straitghten a wire heres a video very simple . And a   HAPPY NEW YEAR everybody  .       http://www.youtube.com/watch?v=meZRMNF-6tQ


----------



## i luvmusic 2

mikelap said:


> In a arts and craft store you could also use big steel paper clips they measure 1mm but you have to measure them to make shure .also if you have coax cable for t.v. i had an old one and the copper cable inside measured 1mm on the other hand the newer cable the copper wire is smaller and if you are wondering how to straitghten a wire heres a video very simple . And a   HAPPY NEW YEAR everybody  .       http://www.youtube.com/watch?v=meZRMNF-6tQ


 
 OK Thanks,  yeah i tried the coax cable i have  they are a bit small it feels loose in the socket and nice tutorial video again THANK YOU!


----------



## gibosi

i luvmusic 2 said:


> Me i asked where did you get the 1mm copper wire for the pins?I can't find them.THANK!


 
  
 Or these might work:
  
 http://www.ebay.com/itm/100pc-gold-plated-tube-pin-for-you-DIY-Tube-adapter-15-1mm-free-shipping-/190863604847?pt=US_Home_Audio_Amplifiers_Preamps&hash=item2c705b7c6f


----------



## gibosi

Since I am now using an external heater circuit, it occurs to me that I can provide enough heater current to use a 6N6P, 6H30P or even a 6N30P-DR as a driver tube in my LD 1+. Has anyone tried this? Any thoughts or comments? Crazy? A good idea?


----------



## MIKELAP

gibosi said:


> Or these might work:
> 
> http://www.ebay.com/itm/100pc-gold-plated-tube-pin-for-you-DIY-Tube-adapter-15-1mm-free-shipping-/190863604847?pt=US_Home_Audio_Amplifiers_Preamps&hash=item2c705b7c6f


 
 How come link doesnt work it happens sometimes  to bad thats interesting would be less trouble one thing less to make


----------



## gibosi

The link doesn't work for you? I just tried it and it worked for me..... ???????
  
 Try searching in eBay for "100pc gold plated tube pin"


----------



## MIKELAP

Cant get it but i see add on left side with picture when i open says page moved or doesnt exist weird ill try again heres a screen shot


----------



## kvtaco17

gibosi said:


> The link doesn't work for you? I just tried it and it worked for me..... ???????
> 
> Try searching in eBay for "100pc gold plated tube pin"


 
  
 Works here...


----------



## MIKELAP

Where is the seller for those pins. Thanks


----------



## kvtaco17

seller is xulingmrs in china


----------



## MIKELAP

kvtaco17 said:


> seller is xulingmrs in china


 
 Thanks for the link it seems he doesnt have anything in his store ?.  I tried  thanks


----------



## Audiofanboy

> Originally Posted by *hypnos1* /img/forum/go_quote.gif
> 
> Hi AFB.
> 
> ...


 
  
 Yup, using that otherwise very basic mains filter made so much of a difference I'm still surprised about it...
  
 I really think the C3g would be be worth the trouble of trying it; I mean, it's an extremely critical frame-grid pentode, and I read that the 6DJ8 would never have been developed in Eindhoven if it weren't for the earlier C3g frame-grid research. So, yeah, I'd say it'd be worth a try!
  


gibosi said:


> £30 is quite reasonable, but unfortunately, this filtering power strip is not designed for use in the US. Does anyone have a recommendation for a similarly-priced unit suitable for 120 volt mains?


 
  
 I'm pretty sure I've seen "AC filter kits" ads at least once recently, looking for information on the MUSES opamps on Japanese forums.
  
 Could be worth taking a look at, seeing as Japan uses the same 110V/60Hz power the US uses. Then again, you might be able to find such a kit directly in the US. It would just require soldering the toroidal and caps directly on some AC cable going to whichever power strip you use (one without a light indicator would be best).
  
 So, no, I don't know of any similarly priced products either for 220 or 110V, and this product is pretty unique in its price range...
  


gibosi said:


> Since I am now using an external heater circuit, it occurs to me that I can provide enough heater current to use a 6N6P, 6H30P or even a 6N30P-DR as a driver tube in my LD 1+. Has anyone tried this? Any thoughts or comments? Crazy? A good idea?


 
  
 Please do! I've been waiting for an opportunity to try this one day, but haven't yet for this exact electrical reason.
  
 ---------------------------
  
 On a lighter note, I got my Amperex Holland 6922 D-getter tubes in the mail, both a pinched waist one and a regular D-getter one.
  
 Just popped the pinched waist one in. Bear in mind I had been listening to a warmed up E188CC minutes before this and left the new 6922 tube to warm up as well before listening (used tube, no burn-in), so I could do a decent comparison between both.
  
 Freakishly real would be the first word to come to mind. That and 3D extreme instrument placement. The PW 6922 has a crazy ability to convey music as emotions and in a being-in-the-room way. Spooky real... So much so that for some tracks, it actually takes a few seconds to "get into the song"; since that's what this tube does, it throws you _inside _the song!
  
 The typical Philips Heerlen E88CC/E188CC sound is definitely there, but just crazy good and real, with liquid musical details flowing so naturally you have to wonder how it's even possible. Even if I ignore the realistic and emotional traits of this tube, the sheer amount of "new details" I'm hearing - and that's compared to the excellent glorious 1960 E188CC - is just astonishing. Crazy I tell you...
  
 Noise/tube rush: I believe my PW Holland 6922 is quiet and not particularly microphonic compared to what many reviewers have written (very very faint usual 6DJ8-type tube rush ), but I can just tell it will never be perfectly silent like my Holland E188CC which never showed _any_ noise or even the slighest "rustling leaves in your backyard" tube rush. Don't get me wrong, I'm not saying my PW is noisy, it is dead quiet, but it just shows - just like all the pragmatic tube rollers I've read comments from - that the E188CC type was invented for a valid reason: to make a perfectly quiet 6DJ8 type, which the the E88CC/6922 is not.
  
 More on this tube and its younger D-getter brother soon. Need more listening time, too much Holiday Season partying time and not enough audio gear listening time!
  
 A happy new year to LD rollers, note that this is the 365th day I've been registered on Head-fi!


----------



## gibosi

mikelap said:


> Thanks for the link it seems he doesnt have anything in his store ?.  I tried  thanks


 
  
 MIKELAP, this is very strange!
  
 When I click this link: http://www.ebay.com/usr/xulingmrs
  
 There are 203 items for sale
  
 Perhaps someone doesn't want you to see this?  lol


----------



## MIKELAP

gibosi said:


> MIKELAP, this is very strange!
> 
> When I click this link: http://www.ebay.com/usr/xulingmrs
> 
> ...


 
 Well finally Superdux found the answer for me i just changed browser and it works i use chrome usually  tried internet explorer and it worked . Now the question is do i want to wait another 11/2 months to get them ?


----------



## gibosi

audiofanboy said:


> Please do! I've been waiting for an opportunity to try this one day, but haven't yet for this exact electrical reason.
> 
> ---------------------------
> 
> Freakishly real would be the first word to come to mind. That and 3D extreme instrument placement. The PW 6922 has a crazy ability to convey music as emotions and in a being-in-the-room way. Spooky real... So much so that for some tracks, it actually takes a few seconds to "get into the song"; since that's what this tube does, it throws you _inside _the song!


 
  
 It turns out that I just happen to have a couple 6N30P-DR laying around here somewhere and I have never even had a chance to fire them up! lol I believe they have the same pin-out as a 6DJ8 (but I want to check this to be sure) so it should be a simple matter of plug and play. Will do this soon....
  
 Speaking of power tubes... The 6SN7GT is often used as a power tube and it occurs to me that since the 6CG7 is essentially a 6SN7 in a miniature 9-pin format, perhaps someone might consider purchasing a nice matched pair of these and trying them as power tubes in their LD? I believe that Artsi has used the 6SN7 as a power tube in his LD?
  
 ~~~~~~~~~~~~~~~
  
 And in the interests of LD research, I assume that you are planning to send your PW 6922, round-robin, to each of us to try for a couple weeks each? lol


----------



## i luvmusic 2

gibosi said:


> Or these might work:
> 
> http://www.ebay.com/itm/100pc-gold-plated-tube-pin-for-you-DIY-Tube-adapter-15-1mm-free-shipping-/190863604847?pt=US_Home_Audio_Amplifiers_Preamps&hash=item2c705b7c6f


 
 THANKS!


----------



## MIKELAP

Started to listen to some octals so far the black glass Tung Sol seems to be superiour to the vt-229 and 6SUL7 bass with the  hd800 is pretty nice


----------



## gibosi

collector13 said:


> I am concerned in my move to put 6cg7 to 6sn7 adapters in place of power tubes.
> I didn't receive them yet, but I read that I need a seperate power supply to run 6sn7's.
> Is that right or does it only apply for driver tube section?
> I'm afraid that I can't use the adapters plug and play...
> (BTW, do 12ax7 tubes have more potential than yugo 6hm5's?)


 
  
 You definitely need an external power supply to use 6CG7/6SN7 as driver tubes. However, you do not need an external power supply to run these as power tubes. The power tube circuit in an LD can provide up to 1.25 amps, I believe. For example, the 6NP draws .75amps, the 6H30-EH draws .85amps, whereas, the 6CG7/6SN7 draws only .6amps, so no problem. And the 6CG7 does not need an adapter. It is 9-pin plug and play.
  
 The 12AX7 is a dual triode, whereas, the 6HM5 is a single triode, so you will need a dual triode adapter to use it. And if you are going to use a dual triode adapter, the 6DJ8 has much more potential than 12AX7 or 6HM5, IMHO.


----------



## Sony Slave

mordy said:


> Hi mab 1376,
> 
> here is post #2078 p. 139 (happy to see that you agree with the reviewer):
> 
> ...


 
Will try this setting once my DT770 pro 80 ohm arrive.


----------



## mordy

Hi Gibosi,
  
 "The 6CG7 does not need an adapter. It is 9-pin plug and play." Did not think of that - thanks Gibosi!
  
*So what we have for the first time is a native US made power tube for the little Dot MKIII! * Been waiting for this a long time. First impression of how the 6CG7 sounds is very promising but need to wait for burn in to complete.
  
 Here are pictures: These tubes were sold by Sears and made by Sylvania - paid less than $2.00 each.
  

 Silk Screen text: Sears: We guarantee that this tube will give perfect satisfaction for one year

 Night view - the glow is very modest

  
 The 6CG7/6FQ7 tube is said to be a development of the octal 6SN7 tube. The transformer housing on the LDIII is barely warm, but the 6CG7 runs VERY hot and I almost burnt my finger now touching it. OK, the 6N6P-IR power tubes run very hot as well.
  
 The driver tube is my best octal so far, a Tung Sol 6SL7GT from 1957. Will see how a shoot out will come out with the Russians. Kind of like the idea of $2.00 power tubes.....
  
 In this lot I also got GE tubes, one RCA tube and a tube that says Cornell. The Cornell has an unusual print on it: New or Used. Judging from the bent pins it probably is a pull out and used.
  
 When do you think the Sears warranty goes into effect? From the time of purchase in the 60's or 70's, or from the first time it is being used 40-50 years later? LOL


----------



## gibosi

Mordy,
  
 It's great that someone tried these as power tubes! And if they turn out to be acceptable, as cheap as they are, you will be able to indulge in the luxury of rolling through the various brands and choosing the one that matches up best with your favorite driver tube of the day.
  
 ~~~~~~~~~~~~~~~~~
  
 Received a 1945 RCA 6SN7GT (equivalent to the RCA VT-231) in today's mail. Grey smoked glass with two rectangular mica ‘ears’ on either side of the round top mica.  From what I have read, RCA manufactured these tubes from 1942 through 1956, but the earliest ones are considered to be the best.
  

  

  
 A huge spacious sound stage with a very lush and warm mid-range and strong bass. This is a very musical tube with superb tonality, instruments simply sound natural and correct, but as one reviewer put it (abeit a bit more crudely), it is something like a very beautiful and voluptuous woman with just a little too much around the middle. No, she's not perfect, but you just can't let her go. lol  
  
 As the Sylvania VT-231 is leaner with less bass, using it as a power tube, and using this warm and bassy RCA as a driver, might be a good match.


----------



## MIKELAP

I was checking out the 6CG7 tubes at  $2.00 each you were really lucky i didnt see anything below $7.00 approx. and usually   there about $15.00 each ill keep looking .


----------



## kvtaco17

SO I've been working on putting together a Lyr VS LD1+ 6DJ8 shootout and instead of going nuts I'm just gonna post my impressions thus far.
  
  
*75 Voskhod*
  
*Lyr:*
  
 Slightly bright and slightly warm... very detailed, big sound stage (trumped only by the Tesla) Good impact and bass quantity without any odd wooliness. Close to neutral with a tube flair.
  
*LD MK1+*
  
 Slightly less neutral then above (mids slightly recessed), similar detail, slightly smaller sense of space, slightly less dynamic... so damn close its not funny. (obviously with low impedance cans) S
  
  
  
*Amperex 70's OG A Frame*
  
*Lyr:*
  
 Warm, lush, detailed and impactful... very musical!
  
*LD MK1+*
  
 Detailed, bassy, very dynamic... lush, enjoyable!
  
  
  
*Amperex Bugle Boys (tubes too worn to get a date)*
  
*Lyr:*
  
 Warm, thick and syrupy... liquid... good bass and mids... somewhat slower then the above tubes, treble is pulled back but pleasant, a good pair to tame a bright headphone OR for someone who likes a very tube-y sound.
  
*LD MK1+*
  
 Pleasant and warm almost the same as the Lyr...
  
*Tesla E88CC*
  
*Lyr*:
  
 Very extended treble, neutral in the mids and bass... GIANT sound stage! Brutally honest... especially with hot or poorly recorded audio... sometimes sibilant.
  
*LD MK1+*
  
 Bright... very detailed... occasionally painful... Similar Huge sound stage to the lyr... Less dynamic... no longer as punchy...
  
  
  
*Amperex 68/69 OG 6DJ8*
  
*Lyr*:
  
 Similar to the A frame, but warmer... very musical but occasionally diffuse...
  
*LD MK1+*
  
 Warm, lust, detailed... might be missing some of the dynamics from the lyr, but not much.
  
  
  
*RCA 6DJ8*
  
*Lyr*:
  
 On the warm side... good treble extension, though occasionally sibilant... not bad nor great...
  
*LD MK1+*
  
 Same deal, on the LD this tube losses out on some dynamics.
  
  
  
*Mullard 6DJ8*
  
*Lyr:*
  
 Soupy, muddy... diffuse... and warm... imagine what the classic tube-y “round” or “rolled off” sound brings to mind and multiply it by 2... Some people with probably love this this BUT its too mushy for me... even with my HD800.
  
*LD MK1+*
  
 Same as above BUT with LESS bass control...
  
 SO far its very close, with the Lyr having better dynamics and slightly better bass control (probably because of all that power on tap)


----------



## gibosi

kvtaco17 said:


> SO I've been working on putting together a Lyr VS LD1+ 6DJ8 shootout and instead of going nuts I'm just gonna post my impressions thus far.
> 
> ..............
> 
> SO far its very close, with the Lyr having better dynamics and slightly better bass control (probably because of all that power on tap)


 
  
 Fascinating! And this reinforces my hunch that a tricked-out LD1+ comes quite close to the Lyr for a lot less money. 
  
 And I have been wondering... since both the LD1+ and the Lyr are hybrids, how much of this difference is due to the way the Lyr configures these tubes and how much is due to a very different solid state output stage....


----------



## kvtaco17

Its close depending on tubes and opamp its 75-80% of the way there... The Lyr is very thick sounding on its own... Whereas the LD has a more graceful way of present music... Both are awesome though!


----------



## Audiofanboy

kvtaco17 said:


> Its close depending on tubes and opamp its 75-80% of the way there... The Lyr is very thick sounding on its own... Whereas the LD has a more graceful way of present music... Both are awesome though!


 
  
 Fascinating comparison, I've been waiting for this kind of review ever since we started using 6DJ8 types on our LDs!
  
_But_, the comparison I would be _even more_ interested in would be between a Lyr and a maxed-out MK III or MK IV.
  
 As a MK IV SE owner - which would be pretty close to the Lyr price range without the premium tubes it come with (~$360 shipped w/o tubes) - I would love a shootout between a 6N30P-DR + Philips E88CC/E188CC MK IV SE and a Lyr with the same driver tubes! I'm pretty sure the results would come out as "surprising" between the two units!
  
 Anyone have both a Lyr, a MK IV and spare cash to buy a the god-tier tubes lol?


----------



## gibosi

audiofanboy said:


> Fascinating comparison, I've been waiting for this kind of review ever since we started using 6DJ8 types on our LDs!
> 
> _But_, the comparison I would be _even more_ interested in would be between a Lyr and a maxed-out MK III or MK IV.
> 
> ...


 
  
 In the interests of LD research, might I humbly suggest that YOU buy a Lyr? lol


----------



## MIKELAP

gibosi said:


> In the interests of LD research, might I humbly suggest that YOU buy a Lyr? lol


 
 here here i second the motion! lol


----------



## kvtaco17

Sweet now I'm off the hook and don't have to buy an mkiii


----------



## Audiofanboy

gibosi said:


> In the interests of LD research, might I humbly suggest that YOU buy a Lyr? lol


 
  
 Think of my poor wallet after Xmas and buying all those premium 6922 tubes lol!
  
 All jokes aside, I keep coming back to the idea of getting a Lyr for my HE-500; but every time I do, I wonder whether it would really be an improvement over the MK IV SE and end up _not_ getting one...
  
 Let's put it this way lol: if someone can compare both a rigged Lyr and a maxed out MK IV, I _might_ be willing to lend him/her/it (you never know who you're talking to these days...) my single pinched waist 6922! How's that for some incentive huh?
  
_Or_, I could import a Lyr to Europe for twice its US price... True...
  
 So many amps to test, so little money...


----------



## kvtaco17

If someone wants to give up their amp for a week I'll compare the mkiii or iv to my lyr.


----------



## i luvmusic 2

I just got my 6HM5(Yugoslavia)it sound really good but when i turned on my LD 1+ i saw a SPARK from the bottom of the tubes. Is these normal?


----------



## i luvmusic 2

I just switch the 6HM5 from LD 1+ to LD MK III it sound alot better with MK III(IMO)but that SPARK still there i guess that spark is normal but should i worry about it.


----------



## kvtaco17

If you mean it kinda flares up on power up that is normal.


----------



## i luvmusic 2

kvtaco17 said:


> If you mean it kinda flares up on power up that is normal.


 
 OK THANK YOU!


----------



## mordy

Hi i luvmusic2,
  
 Please read post 3544 on page 237 from one of the members on this forum. The flash is a quick heating up feature for military applications and normal for this specific tube.


----------



## i luvmusic 2

mordy said:


> Hi i luvmusic2,
> 
> Please read post 3544 on page 237 from one of the members on this forum. The flash is a quick heating up feature for military applications and normal for this specific tube.


 
 Sure i will THANK YOU!


----------



## i luvmusic 2

Tubes i have so far 6HM5,Motorola 6BE6,RCA 6DK6,TUNG-SOL 6CS6,RCA 6DT6,BRIMAR EF92,International Sylvania 6AK5,PHILIPS MINIWATT EF91,JAN-GE5654W Do you guys have more plug and play tube suggestions?


----------



## mordy

Hi i luvemusic2,
  
 Go to page 77 post #1154. The column on the left with the heading EF95 lists all plug and play tubes on the EF95 setting with a green yes.
  
 To the right of this column is a column labeled EF91/92. Any tube with a green yes under this heading is plug and play _*using the EF92 setting*_ on the amp.
  
 The following power tubes are plug and play (the big tubes in the back of the amp):
  
 6N6, 6N6P, 6N6P-i, 6N6P-IR, 6H30, 6H30-DR (the last two tubes only with circuit revision v.2)
  
 6CG7 and 6FQ7
  
 Which driver tubes do you like the best?


----------



## i luvmusic 2

mordy said:


> Hi i luvemusic2,
> 
> Go to page 77 post #1154. The column on the left with the heading EF95 lists all plug and play tubes on the EF95 setting with a green yes.
> 
> ...


 
 TUNG-SOL 6CS6/EH90(2 Pairs)and 6HM5(another pair on it's way)any tubes that i really like i always buy 2 pairs. so far i have 17 pairs some are double pairs.So for the 6CG7 and 6FQ7 are they better than 6N6P-i?THANKS!


----------



## i luvmusic 2

That suggest i like all my TUBES.....


----------



## mordy

Hi 2,
  
  
 "So for the 6CG7 and 6FQ7 are they better than 6N6P-i?" That's a good question. However, unless you want to spend mega bucks for the 6H30-DR tubes, the 6N6P-IR are the best power tubes, and the IR's should be the comparison.
  
 So how do the 6CG7/6FQ7 compare to those tubes? I am afraid that I cannot give you a solid answer yet, because this is uncharted territory, and we tried the 6CG7s for the first time as power tubes yesterday. I would say that you need 50-100 hours of burn in to stabilize the tubes.
  
 Then you have the human factor. I am used to a certain sound that I am very familiar with, using the 6N6P-IR as reference power tubes. When I try a new tube I have a frame of reference, and I can detect small differences. Now everything changed, and I have to try to find the right combination of driver tubes for the new power tubes.
  
 At this point I can only say that they sound different, and they sound quite good, but not more. (Briefly tried the 6FQ7 GE tubes and some unknown (RCA?) tubes, but it did not sound good - too bright and thin). Tried with the Amperex 6DJ8 as a driver tube - a little better. Then I stuck in the Sears 6CG7 tubes (Satisfaction Guaranteed Or Your Money Back) nee Sylvania, and things got better. Even better when I used my Tung Sol 6SL7*G*ran *T*ourismo tube as a driver.
  
 It's like moving into an unfamiliar neighborhood where you don't know the streets and you don't know your way around. In addition, _audiophilia nervosa _sets in, things don't feel right and don't sound right; the music doesn't get to you the right way. The magic is gone, kind of...
  
 Oh well, what don't we do to advance the science of tube imperfection....


----------



## Nic Rhodes

Surely the obvious alternatives to the 6N6s are the 5687, 6900 (rare and expensive) and the E182CCs (7119?) type tubes. They just need a simple adapter for to work.


----------



## mordy

Granted, but the question asked was which tubes work plug and play without any modifications.
  
 Need an answer to the following:
  
 With the 6CG7 tubes the octal driver tube I am using runs much hotter than with the IR tubes. The plate voltage is 173V, which is higher than what I measured in the past with the IR tubes - around 147V.
  
 Could it be that such a high voltage is detrimental to the tube? (Heater voltage is 6.3V and grid voltage is 1.33V).


----------



## mojorisin35

I have been auditioning the Amprex 1968 OG 6DJ8 I received from Audiofanboy with Mikelap's amazing adapter and my mind is Blown! Wow !
  
 Gary


----------



## Audiofanboy

mordy said:


> Granted, but the question asked was which tubes work plug and play without any modifications.
> 
> Need an answer to the following:
> 
> ...


 
  
 Speaking of voltages, has anyone formally measured the voltages for both 6N6P and 6N30P tubes? Since I don't have any 9-pin socket savers - let alone some with test points - it would pretty difficult to measure for me...
  
 Fresh measurements with the Amperex Holland PW 6922:
  
 Wall = 224V
 Heater = 5.76V (despite the 6922 using less current than both the 7308/E188CC...)
  
                    L                     R
 Cathode = 2.08V               2.09V
 Anode    = 75.6V              74.6V
  
 Heater voltage is out of spec as usual, but then again the different premium 6DJ8 tubes I've tried up to here seem to do _quite_ well regardless, so I guess I should just stop worrying about it... Tubes _might_ have a longer life that way too, maybe...
  
 Triodes are almost a perfect match as is almost always the case with the premium Philips 6DJ8 types. Fine tubes, I reckon.
  
 I was originally asking about formal 6N6P & 6N30P measurements since I recall someone mentioning that the driver tube plate voltage should be about half of the power tube plate voltage; and while my 75V driver tube plate voltage and most other folks' 80V figures for that type seem slightly below the "nominal" 90V, it is exactly half of Mordy's reported 6N6P-IR plate voltage... So, it should seem like yet another sign the LD amps were _made_ to accept 6DJ8s...


----------



## Audiofanboy

mojorisin35 said:


> I have been auditioning the Amprex 1968 OG 6DJ8 I received from Audiofanboy with Mikelap's amazing adapter and my mind is Blown! Wow !
> 
> Gary


 
  
 Nice! Good timing, seeing as I was about to PM you to know if you had gotten the package...
  
 Yup, the OG are pretty amazing tubes and really do give you that "holy Schiit" moment!
  
 Now wait until you get the urge to get the even more premium types lol... Mind may be blown a few more times!


----------



## Sony Slave

mikelap said:


> Started to listen to some octals so far the black glass Tung Sol seems to be superiour to the vt-229 and 6SUL7 bass with the  hd800 is pretty nice


 
 I wonder what would happen if you guys started selling modified Little Dots, I would be the first to buy one!


----------



## TrollDragon

sony slave said:


> I wonder what would happen if you guys started selling modified Little Dots, I would be the first to buy one!


Then they would be called DarkVoice or BottleHead...


----------



## Sony Slave

trolldragon said:


> Then they would be called DarkVoice or BottleHead...


 
 I wouldn't be surprised if it has the sound of the dark voice, but at a lower cost.
  
 On topic, it seems like members are taking the Little Dot to uncharted territory. As a matter of fact, do you or anyone else know how the best heavily modified Little Dot 1+, MKIII, or MKIV  setup sounds compared to other "high end" tube amps?


----------



## MIKELAP

audiofanboy said:


> Nice! Good timing, seeing as I was about to PM you to know if you had gotten the package...
> 
> Yup, the OG are pretty amazing tubes and really do give you that "holy Schiit" moment!
> 
> Now wait until you get the urge to get the even more premium types lol... Mind may be blown a few more times!


 
  You dont want that happening to often its not a pretty sight  !


----------



## i luvmusic 2

To my surprise my LD 1+ did not HUM with the Fleetwood 6CB6 and Westinghouse Premium 6BA6.


----------



## sam6350

So just an update guys,
  
 I took Mike and Mordy's advice and my 6HM5's came in today. Apparently my other tubes were not in fact lost in the mail, they were just horribly late, so I got some Electro-Harmonix 6H30pi's running as well.
  
 After plugging them in, my first thought is... HOLY CRAP!

 I'm not sure how to describe this. The 6HM5's really bring out the sound.. everywhere really. The music has more "pop"; it seems richer.. if that makes sense. Only down side is that one of the 6HM5's seems to be an exceptionally sensitive tube. I can touch any of the other ones and get no hum, but with this one.. if I even touch it lightly it'll hum. It was humming all the time at first, but I switched its position and wrapped it in tin foil; so now it's fine.

 But yeah.. holy crap. I think I'll test out my voshkod's next, and see if I can tell the difference since both are supposed to be great.

 Thanks again everyone :-D


----------



## TrollDragon

Well a bit of an update on my copper tube adapter, each one of my 6DJ8's hum, the 6N23P or 6N2P not so much hum but there was a faint bit of tube rush in those. The Siemens 6DJ8 was the absolute worst the hum on it was exceptionally bad and would NOT go away.
  
 So I build a test adapter with a little bit of Mogami Star Quad and a twisted pair of 18 AWG heater wires. I kept the heater wires away from the A/G/K wires as much as possible and all the hum is gone, even the tube rush from the Soviets. So I am going to have to re-engineer my tube adapter.
  
 1) Heater wires brought outside through a hole in the bottom and top at the back of the adapter.
 2) Run new heater wires in the pipe using shielded wire, attaching each end of the shield to the pipe.
 3) Create a new adapter out of lexan, with the Tube rings removed so it is only as thick as an octal socket and plugs right in over top of the B7G sockets. (<- Leaning this way.)
  
 So much fun we go through with this hobby, the BreadBoard option would most likely work the best but would not have the *WAF* where my amp is situated.
  
 Here is the totally silent test adapter with a 6N23P installed and my new German Maestro GMP 8.300 D Professionals...


----------



## kvtaco17

I had the same issue and regardless of what I tried it never went away... UNTIL I added an external DC regulator of the heater circuits AND grounded the - lead to the chassis as per Gibosi... hope that helps.
  
 Disregard this lol I need to learn to read better when I'm sleep deprived (yay hr 34!)


----------



## TrollDragon

kvtaco17 said:


> I had the same issue and regardless of what I tried it never went away... UNTIL I added an external DC regulator of the heater circuits AND grounded the - lead to the chassis as per Gibosi... hope that helps.
> 
> Disregard this lol I need to learn to read better when I'm sleep deprived (yay hr 34!)


 

 Get some sleep good sir, It's not good for the system to go without!


----------



## kvtaco17

I will in a bit... I've had pretty nasty bouts with insomnia lately... nothing helps... my doctor suggested taking a mild sleep aid... that was hours ago and I'm still making an amp enclosure design in autocad...


----------



## TrollDragon

Well good luck to you in your battle with the insomnia, I can't imagine what it would be like having never suffered from it myself.


----------



## kvtaco17

Its just been lately... I assume its stress related with, work and the passing holiday, things will calm down and it'll subside.


----------



## gibosi

mordy said:


> Need an answer to the following:
> 
> With the 6CG7 tubes the octal driver tube I am using runs much hotter than with the IR tubes. The plate voltage is 173V, which is higher than what I measured in the past with the IR tubes - around 147V.
> 
> Could it be that such a high voltage is detrimental to the tube? (Heater voltage is 6.3V and grid voltage is 1.33V).


 
  
 Mordy,
  
 Perhaps Ctritical Bill (CB) will weigh in on this.... However, from one of his earlier posts, it would seem that this is not good....
  
 http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/4125#post_10027162
  
 If I understand CB correctly, a plate voltage of 173 V on your 6SL7 driver tube may be close to over driving your 6CG7 output tubes. Again, if I understand correctly, the 6SL7 works best with a plate voltage around 200 V and the LD simply cannot provide a driver tube with voltage this high. So even though it sounds good, it is probably not advisable....
  
 But again, if I understand correctly, this is more an indication of the unsuitability of the 6SL7 as a driver tube in the LD, than it is a problem with using the 6CG7 as an output tube. Once you get an external heater, using a 6SN7 or 6CG7 as a driver could well be better.


----------



## i luvmusic 2

I finally did my first 9pin(Driver Tubes) adapter for LD 1+ and LD MK III i've used a 12AU7/12AU7A(Rogers,Electro- Harmonix,JJ Electronics and  Chinese made)those are the only tubes i have.They all hum on both amps i doubble checked all my solder joints and pin connections to the amp(unplug/plug it back)still humming.Could it be the Tubes?


----------



## kvtaco17

i luvmusic 2 said:


> I finally did my first 9pin(Driver Tubes) adapter for LD 1+ and LD MK III i've used a 12AU7/12AU7A(Rogers,Electro- Harmonix,JJ Electronics and  Chinese made)those are the only tubes i have.They all hum on both amps i doubble checked all my solder joints and pin connections to the amp(unplug/plug it back)still humming.Could it be the Tubes?


 
  


kvtaco17 said:


> *I had the same issue and regardless of what I tried it never went away... UNTIL I added an external DC regulator of the heater circuits AND grounded the - lead to the chassis as per Gibosi... hope that helps.*
> 
> Disregard this lol I need to learn to read better when I'm sleep deprived (yay hr 34!)


 
  
 Boom! lol


----------



## TrollDragon

What kind of adapter did you build / use? Do you have any pictures of your adapter setup you could post?


----------



## MIKELAP

Ive made a 6DJ8 adapter a 12AX7 and an 6SL7octal adapter and i have only1 tube that has a very very faint hum  out of 7octals. the 12ax7 the 6DJ8 nothing .I would like to know how come some adapters hum and some others dont .Like Mojorisin adapter on my amp perfect on his amp buzzing how come i would like to know the answer to that one .Any ideas guys !


----------



## TrollDragon

Lexan is the Answer!  Now what was the Question?
 Oh yeah Hum...
  
 Lexan piece cut to fit the top of the driver tube rings, center front screws hold the lexan in place and it's very easy to install and remove if required. I had cut the bottoms out of those nasty NEC 6AV6's to use as B7A plugs and remembered that pins 5&6 had been cut off. No big deal the adapter just has to run in EF92 mode instead of EF95.
  
 Ceramic B9A socket attached to the lexan and wired up to the old 6AV6 base pins, short wires A/G/K wires with a twisted heater supply and this adapter is totally silent with no music playing.
  
 The Lexan was cut with a jig saw so it is far from perfectly shaped, I'd kill for a scroll saw and a drill press... 
	

	
	
		
		

		
			




  So without further ado... The money shots with a 6Н2П-ЕВ

  
 Top View

  
 Side View


----------



## kvtaco17

mikelap said:


> Ive made a 6DJ8 adapter a 12AX7 and an 6SL7octal adapter and i have only1 tube that has a very very faint hum  out of 7octals. the 12ax7 the 6DJ8 nothing .I would like to know how come some adapters hum and some others dont .Like Mojorisin adapter on my amp perfect on his amp buzzing how come i would like to know the answer to that one .Any ideas guys !


 
  
 AC input noise is my very early assumption... Mine had a ton o' hum initially... running it with my home theater power conditioner reduced 90% of it... BUT going to the DC regulator and tying the - input lead to the chassis ground solved everything 100%! I'll look into it more tomorrow.


----------



## kvtaco17

trolldragon said:


> Lexan is the Answer!  Now what was the Question?
> Oh yeah Hum...
> 
> Lexan piece cut to fit the top of the driver tube rings, center front screws hold the lexan in place and it's very easy to install and remove if required. I had cut the bottoms out of those nasty NEC 6AV6's to use as B7A plugs and remembered that pins 5&6 had been cut off. No big deal the adapter just has to run in EF92 mode instead of EF95.
> ...


 
 well done!


----------



## i luvmusic 2

trolldragon said:


> What kind of adapter did you build / use? Do you have any pictures of your adapter setup you could post?


 
 I just used the 9 pin socket saver from Ebay soldered 18 gauge speaker wires on the pins and used coax cable solid conductor on the other end of the 18 gauge speaker wires(Pin)for plugging it in to the amp.Sorry i already took it apart i just tried it while i'am waiting for my ceramic tube sockets and other parts from the online retailer i just can't wait for it that is why i used what i have for now.I will give it a try once all the proper parts arived.
 I will let you guys know when i'am done with the new one, i hope i'am not going to have the same problem.You guys are helpful  THANK YOU!


----------



## i luvmusic 2

trolldragon said:


> Lexan is the Answer!  Now what was the Question?
> Oh yeah Hum...
> 
> Lexan piece cut to fit the top of the driver tube rings, center front screws hold the lexan in place and it's very easy to install and remove if required. I had cut the bottoms out of those nasty NEC 6AV6's to use as B7A plugs and remembered that pins 5&6 had been cut off. No big deal the adapter just has to run in EF92 mode instead of EF95.
> ...


 
 Very nice, the socket you have is similar to the one that i ordered(9 PIN CERAMIC CHASSIS MOUNT)the one i just did is more like what you have in your pictures only deffirence is i did not used a shrink tube on the pins to the amp Oh and my is UGLY.


----------



## i luvmusic 2

kvtaco17 said:


> Boom! lol


 
 I have to look into that once i'm done with the proper adapter.THANKS


----------



## mordy

I have discontinued the use of the 6CG7/6FQ7 tubes as power tubes since I am afraid that they are not suitable and will overdrive and damage the driver tubes. Measured over 208/216V plate voltage on a 12AX7 tube which I think is too much .
  
 When I get my voltage regulator (on a slow boat from China) I will try these tubes as driver tubes.


----------



## Ctritical Bill

gibosi said:


> Mordy,
> 
> Perhaps Ctritical Bill (CB) will weigh in on this.... However, from one of his earlier posts, it would seem that this is not good....
> 
> ...


 
  
 What you are seeing here is the effect of an unregulated power supply. The 6N6P powertubes put out about 20 ma and the 6CG7 probably less than half that so the lower current draw increases the B+ . You have it exactly right in saying the 6SN7 is a better choice than the 6SL7.
 I noticed on the Little Dot forums this post - http://www.littledot.net/forum/viewtopic.php?f=3&t=2558&sid=178231eb44fc074676fcd7b72f273695 where David Zhezhe says "The 6CG7 is usable however the 6BQ7 is not." in response to a question on power tube rolling in the MK111. However, someone tried the 6CG7 and was not impressed but I think this may be due to the use of lower impedance headphones as with higher impedance the lack of current shouldn't be a problem.


----------



## Artsi

trolldragon said:


> Lexan is the Answer!


 
 Now this is one good looking adapter. Congratulations!
 Hum is one serious problem with tube amps. And if DIY adapter or amp is not humming one could be very pleased with himself. I can't stand any hum, it drives me crazy.
  
 Here is something about my latest DIY amp, if someone is interested...
http://www.head-fi.org/t/698282/my-diy-6sn7-6as7-headphone-tube-amp
  
 btw my 6sn7-6as7 amp is much smaller on desk area than LD MK IV, but higher.


----------



## vic2vic

trolldragon said:


> Ceramic B9A socket attached to the lexan and wired up to the old 6AV6 base pins, *short wires A/G/K wires with a twisted heater supply *and this adapter is totally silent with no music playing.


 
  
 Hi all.
 I've also just finished to build my 9pins --> 2x7 pins adapter for LD MKII+ , which includes a switch to commute between 6DJ8 and 12AX7 modes (for the moment not yet into a case as I'm still slooooooooooooowly waiting for the case delivery).... but it's humming a lot  
 Strangely, the hum depends on how high I pull the driver tube (a 6N23P Voskhod 1975): if it's stretched all the way up (wires completely extended), it hums like hell; if I push it down almost in between the 7 pins sockets... dead silent.
 I guess that by pushing it down, I keep some wires apart and so I reduce some cross interferences. Or maybe I ground some wires by touching them and this solves the problem. I do not know.
  
 As I'm a noob in electronics, I'm actually quite curious about the sentence in bold above: what actually does it mean to short A/G/K wires with a twisted heater supply, and will this potentially help me to reduce the hum?
  
 BTW, I also made an octal --> 2x7 pins adapter, and this one is humming a bit less, but still not silent 
	

	
	
		
		

		
		
	


	



  
  
 I take the chance of this message also to thank all of you for your precious help, inspiration and suggestions for taking this further step into the LD tube rolling realm.
 Without your ideas (especially Artsi's help, with his wonderful walkthrough for the switched adapter), I'd have never made this attempt into the "diy adapters" world.
 And for whoever is thinking if they should try to build these adapters, I can just say DO IT !
 It's easy, cheap, rewarding and with the help of guys like gibosi, mordy, TrollDragon, MIKELAP, Artsi, etc you can not go wrong (but I take no liability for encouraging you to take this step if your amp explodes, incinerates, detonates, evaporates, implodes or melts while you test your adapter  
	

	
	
		
		

		
		
	


	




)


----------



## TrollDragon

Thanks @kvtaco17 @i luvmusic 2 @Artsi and @vic2vic I think this one performs so much better than my copper pipe adapter for 6DJ8's, but I will modify the pipe for octal tubes.
  
  
 Quote:


vic2vic said:


> Strangely, the hum depends on how high I pull the driver tube (a 6N23P Voskhod 1975): if it's stretched all the way up (wires completely extended), it hums like hell; if *I push it down almost in between the 7 pins sockets... dead silent.*
> 
> As I'm a noob in electronics, I'm actually quite curious about the sentence in bold above: what actually does it mean to short A/G/K wires with a twisted heater supply, and will this potentially help me to reduce the hum?
> 
> BTW, I also made an octal --> 2x7 pins adapter, and this one is humming a bit less, but still not silent


 
 Hey vic2vic
  
 With most builds of tube amps out there the heater wires are twisted together to cancel out the AC 60Hz hum. When they route these wires they either run them close to the case or at 90° to the other wires. When you run the heater wires parallel to the *A*node / *G*rid / *K*athode wires the AC will induce a magnetic field into the parallel wires and you get hum, this is the case with my copper pipe adapter. So what I am going to do is either run the heater wires outside of the pipe up the back so they are not visible, or run shielded heater wires with the shield attached to the top and bottom of the pipe pieces. Both of these possible solutions have to be tested yet and will probably be later on as I will be enjoying my music with the little lexan adapter for a while. 
	

	
	
		
		

		
		
	


	



  
 The external DC heater board will solve your hum problems but it also depends on your application and situation if the external is feasible or not. I was pondering the use of a Low Dropout Rregulators (LDO) with a Schottky Bridge and a few caps... built into the back of the LD MK IV as the LDO's will still regulate with a source of only 0.2V higher than the output. Taking in account the voltage drop of the diodes and filter capacitors, it could be done with a MK III or IV chassis, not too sure about the MKII as there is less room.
  
 To sum it up I would move your heater wires around, make them longer and keep them away from the other wires, route them at 90° if possible and see if that doesn't remove the hum. The *BOLD *part in the quote tells me that it's most likely a wire routing thing. I tried to keep my A/G/K  wires as shot as possible on the lexan adapter to see if that had a any effect. It shouldn't since others are running the BreadBoards with 6" of wire from the vectors to the board all in the open air BUT with enough distance from the heater wires.
  
 Modify, test, adjust and modify more, It's all part of the fun we have here when you have something that is hum free take some time and enjoy your music as that is the whole purpose.




  
  
** Always remember there are LETHAL voltages on some of the pin's, so be careful and have fun.* *


----------



## Audiofanboy

It's nice to see so many people finally taking a leap of faith and building their own double triode adapters! Trust me, it's the best decision you'll have ever made for your LD! 
	

	
	
		
		

		
		
	


	



  
 Of course now you need good tubes for your sparkly or less sparkly adapters. While I can give ideas and review tubes, I can't make pretty adapters like all those cool kids here lol. But, I can help choose premium 6DJ8 (and empty your wallets)!
  
 So, after spending ~30h with my Pinched Waist Amperex Holland 6922 (7L3 batch), I tested the Amperex Holland non-PW D-getter 6922 from the 7L4 batch.
  
 Basically another tremendously good tube, honestly. Transparent and ultra-detailed as hell, with a sense of immediacy and PrAT that's possibly the second best I've heard in the 6DJ8 family. Highs and lows are well extended, with shimmering treble and tactile bass. Soundstage and sense of 3D are excellent with pinpoint accuracy and instrument placement; truly one of the best tubes I've heard to date. Listening to this tube with virgin ears (as in not right after listening to another tube for an hour), I almost started to think it was better than the PW 6922, and in some ways or for some people it very well may be. For the first three songs, the illusion was almost perfect, but after 15 minutes I started to have a _doubt_.
  
 So of course, after letting the amp cool down, I threw the PW back in and let it warm up again. It didn't take me long to figure out what had been bothering me. In one word: _the music_. Let me explain.
  
 I'd mentioned the last time around that the PW almost made it seem like you were _in_ the music and not just listening to it - and also mentioned that it was often destabilizing and difficult to get used to depending on the track (hard to get "into"). Well, that may be the non-PW 6922 7L4's only fault: to be the best tube to _reproduce_ music but not to be _in_ it. I know this sounds silly, but let me explain what I mean a bit more.
  
 The second you play a track with the PW, you don't even need to close your eyes to feel that you're in a enclosed space with realistic reflections (a sense of true "wetness" to the sound) and liquid tame instrument and voices playing. There's no real 3D or holographic effect anymore, just a studio in front of or in between your eyes, like you're in a smoky club after five drinks or in a studio after working 20 hours without a break, just staring at the musicians in a daze and letting the music "sink in" because you're too tired to tap your feet and really listen at this point. Well that's what the PW are like, and it can make you feel uncomfortable when you're expecting a punchy and forward headphone music session.
  
 The sound just doesn't sound immediate, forward or infinite. It sounds like the exact opposite, it's like a dreamy vague yet ultra-precise room with a sense of absolute boundary that's there but hard to pinpoint. The dream vs music analogy is actually as accurate as I can be in describing the difference between both tubes. the non-PW 7L4 is the best for rendering music, punchy and immediate, but it's still just reproducing a signal; while the PW 7L3 shows you a vivid dream of that very same signal with finer details like your brain is filling in the gaps in the story (think about how realistic some dreams are, despite being pure brain fiction of stuff you may have never seen or heard), and as we all know how some dreams can leave a very very strong impression for days at a time and others forgotten right away. So for some tracks the PW almost sounds too much like a waking dream and not immediate enough, making you want to switch back to a tube that just reproduces the music and does it well, but at the same time once you've seen the dream, it's hard to go back to reality lol...
  
 I guess if you were to twist my words just a little, you could sum up all this crap I wrote and describe the PW as a wet dream, and the non-PW as a cool concert. Both might leave a strong impression on you, but in a dramatically different way lol...
  
 Last thing, the Holland D-getter 6922/E88CC I just tested actually reminds me quite a bit of the US 6922 (early ones, 1962 and before): punchy, dynamic and extended, but the Holland D-getter version is more detailed and realistic. Oh, and both the 7L3 PW and 7L4 non-PW tubes are basically perfectly quiet; not mute like the E188CC but totally silent.
  
 Edit: Speaking of my _Tour de France_ of premium 6DJ8, I'm still waiting for my single US Amperex VR0 D-getter 7308 (about as rare as the PW 6922, if not rarer) which is still stuck somewhere between the US and Europe after a forced - and slightly ironic - layover in Israel on Xmas eve lol... Hopefully, it isn't really lost... I'm looking forward to this tube since it would be a good chance to compare some of the absolute oldest an most premium US 6DJ8 to the European ones. Anyway, we shall see...


----------



## MIKELAP

About the octal adapter im working on would it help the humming issues you think by soldering a small pipe on the exteriour of the adapter and having the 2 heater wires pass thru that pipe and soldered  to there respective pins and would the wires need to be insulated you think or just the fact that they are not next to the other wires be ok except where they go back in the main chassis.Heres a picture .


----------



## gibosi

audiofanboy said:


> The second you play a track with the PW, you don't even need to close your eyes to feel that you're in a enclosed space with realistic reflections (a sense of true "wetness" to the sound) and liquid tame instrument and voices playing. There's no real 3D or holographic effect anymore, just a studio in front of or in between your eyes, like you're in a smoky club after five drinks or in a studio after working 20 hours without a break, just staring at the musicians in a daze and letting the music "sink in" because you're too tired to tap your feet and really listen at this point. Well that's what the PW are like, and it can make you feel uncomfortable when you're expecting a punchy and forward headphone music session.


 
  
 Of course, it is terribly difficult to put into words what we hear...  But I think I could use these same words to describe the 6SN7: There is a strong sense of being in "an enclosed space with realistic reflections (a sense of true "wetness" to the sound)" and very liquid.  After having been totally blown away with the premium 6DJ8, it has taken me awhile to wrap my head around these octals, but I am now beginning to think that I prefer the 6SN7 over the 6DJ8....  And perhaps a Darkvoice 336 over a Lyr.....


----------



## TrollDragon

mikelap said:


> About the octal adapter im working on would it help the humming issues you think by soldering a small pipe on the exteriour of the adapter and having the 2 heater wires pass thru that pipe and soldered  to there respective pins and would the wires need to be insulated you think or just the fact that they are not next to the other wires be ok except where they go back in the main chassis.Heres a picture .


 
 Liking the Hammertone finish but I think that would be too much work.
  
 Unless you ran one on each side like twin feed pipes on an intake manifold... Yeah I'ma be liking that Idea!
  
 Just Kidding...
 Try a shielded wire to the heater filaments first.


----------



## mordy

Don't know if this helps, but in regard to a bread board adapter I found that little thicker wires helped against the hum, and that moving around the bread board in different directions, as well as up or down, would enable me to find a position with less hum. (Obviously this does not work with a stationary adapter plugged into the amp). In addition, moving around the individual wires would also reduce the hum.
  
 However, when turning the volume up to a considerably higher level than I normally listen to, there is always a hum. Sometimes I need this high level with a low gain recording, and you notice the hum on soft passages. Looking forward to get my voltage regulator that may get rid of the hum.


----------



## gibosi

I had a few small packages arrive today:
  
 An RCA 6FW8
  
 Back in the day, RCA decided not to manufacture the 6DJ8. Instead, they developed and manufactured their own tube to compete directly with the 6DJ8. However, it sold poorly, and in the end, RCA purchased the 6DJ8 from other manufacturers and rebranded it as their own. Anyway, there is not much information about this tube in audio circuits, so I decided to give one a try.
  

  
 A 1952 CBS/Hytron 6SN7, rebranded as a Motorola (CBS/Hytron's EIA code is 210). From what I have read, the CBS tube is an excellent tube and often quite cheap. And as this one carried a Motorlola label, I got it for only $7.74 shipped.
  

  
 And finally a couple of Loktals, a 7N7 and 7AF7. The 7N7 is electrically identical to the 6SN7. And the 7AF7 is electrically identical to the 6AH7. The 6AH7 is the octal predecessor of the 12AU7, and in a sense, it would seem to be a 300ma version of a 6SN7. These were dirt cheap, $2.00 a tube, shipped. However, I am still waiting for an adapter.....


----------



## Nic Rhodes

At last someone has found the great loctals. You will enjoy both of these. Fine tubes at cheap prices. The 7N7 is plentiful and a fine performer. The 7AF7 is much rarer.... If you enjoy these try the 6F8G or the BL63s (not loctals but top caps of similar era)  For the latter you will need a good budget and a PSU also.


----------



## TrollDragon

I like how the heater on the 6BQ7A runs across the bottom of the tube.


----------



## mordy

Today I got a Crosley 6SL7 made by Sylvania. It was advertised as a Westinghouse made by Sylvania from 1943. I don't think that the box below matches this tube:
                                                                                                                                            
  

  
 I assume that the blue stamp was added to correct the misspelling of the word "Contracror" at the end of the Westinghouse line. Here is the tube:
  

 On the glass is etched 6SL7GT and below, the letters EOM. The base has the number 312 which is the EIA code for Sylvania and the number 039.
 EOM? Maybe May 1950/60? 039? Sept 1950/60? Don't know - but what matters is that this tube sounds excellent. Really good.
  
 What about Crosley? Wel,l did you know that Crosley was the largest US manufacturer of radios in the later part of the 1920's? They made refrigerators, cars, TVs etc etc. _However, what matters most to us here on the Little Dot forum is that Crosley as early as1925 served as the inspiration of the styling of the LD amp ._
  




  
  




  
 The Crosley Pup radio cost $9.75 in 1925 = $130 today. Here is a happy early Head Fi-er.
  




  
  
 Here is something for you sports fans out there:1925 CINCINNATI REDS SHARE HEADPHONES AND CROSLEY PUP RADIO MASCOT  (Don't know if  Messrs Zhe Zhe and Sword could afford such an advertisement today):
  
  
 BTW, paid less than $5 for the tube.
	

	
	
		
		

		
		
	


	



 Have fun!
  
 Could not resist adding this picture of a 1947 Crosley cabriolet:




 And a 1942 Crosley Liberty Sedan


----------



## LogicAudio

does anyone know the original manufacturer of "Delta 6080" tubes? they are labled "Delta 6080" and "USA". any idea?


----------



## mordy

Hi LA,
  
 It appears that Delta was a rebrander. Therefore, it could be any US manufacturer. Look for a three digit manufacturing code such as 312 or 374 etc. Only way to identify tube without this code is to compare it to a known source that looks identical.


----------



## Audiofanboy

Quick comparison of premium 6DJ8 tube sizes that should help explain the "tall bottle" expression I've read about a few times:
  

  
 From left to right:
 - Amperex US 6922, 1962 -> regular glass "bottle" height
 - Philips Holland E188CC, 1960 -> regular glass "bottle" height
 - Amperex Holland 6922, D-getter, 1959 -> tall "bottle" height (tallest of the four, with a distinct balloon-like top)
 - Amperex Holland 6922 "Pinched Waist", D-getter, 1958 -> tall "bottle" height (higher than later tubes, but quite not as tall and round top as the D-getter 6922)
  
 Just food for thoughts, could come in handy for ebay lurkers...
  
 Btw, the Philips Holland E188CC are up for sale (need cash for imminent long trip to Japan lol). It's a - matched NOS NIB - pair, but it could be dissociated if two people were interested in a single tube. _Ya nevah' know..._
  
http://www.head-fi.org/t/698861/flash-sale-philips-holland-e188cc-matched-nos-nib-1960


----------



## Oskari

mordy said:


> 039?


 
  
 That's YWW, but sometimes only weeks 13, 26, 39, 52 were used, so 39 could mean 3rd quarter.
  
 Funny looking vehicles those Crosleys.


----------



## LogicAudio

mordy said:


> Hi LA,
> 
> It appears that Delta was a rebrander. Therefore, it could be any US manufacturer. Look for a three digit manufacturing code such as 312 or 374 etc. Only way to identify tube without this code is to compare it to a known source that looks identical.


 
 thanks man.
 actually I have Tung-Sol, RCA, Telefunken, Delta and a Russian brand 6080/6AS7 tubes and I've compared all of'em to Delta but none of them is identical to Delta. I have an image of Delta which I used in a project. I appreciate if anyone could help to identify this tube:


----------



## Oskari

mordy said:


> EOM? Maybe May 1950/60?


 
  
 Yep. E0 = May 1950. Probably. In this case. The date of manufacture.


----------



## mordy

Hi Oskari,
  
 The first tube of this type appeared in 1941, the 0 could not be 1940. What's your feeling, is it 1950 or 1960? The green print is supposed to be less common.
 Sorry, I did not read the second post when I replied - thanks.


----------



## mordy

Hi LA,
  
 Does this tube have a metal base?


----------



## mordy

For the tube aficionado who has everything - A chess set using vacuum tubes:


----------



## Redstrand

That is the coolest thing, I'd take up chess again....lol


----------



## MIKELAP

Just received 4 Reflektor made  6H9C octals and so far they are  no slouch compared to the more pricey Tung sol or Sylvanias  and all of that for $9.00 +shipping good deal i would say .


----------



## TrollDragon

mikelap said:


> Just received 4 Reflektor made  6H9C octals and so far they are  no slouch compared to the more pricey Tung sol or Sylvanias  and all of that for $9.00 +shipping good deal i would say .


 
 Nice!
 I have the same tubes and they do indeed sound very good!


----------



## mordy

Hi,
  
 I too, have two 6H9C octals, but found the early Sylvanias and Tung Sols better. Mine is from 1981 + unknown; had asked for 1960's tube.
  
 Here is a beautiful picture of a vacuum tube (long exposure) from Finland:
  




 The blue light (in the little squares) is called the Geissler effect. Not much is known about it, but it does not harm the tube.


----------



## gibosi

artsi said:


> I can use 6SN7 to 6AS7 as powertubes and 6SL7 and 6SN7 as drivers. ECC32 should work too as driver, but they are far too expensive. Power consumption of amp is around 88w with 6080's and 6SN7's. So now i can use my precious 6SU7GTY's. With -73 6N13S's i received four -65 6N8S with square getter. So far they sound very good. I think this model should be the best of non-metal base 6N8S's. http://www.ebay.co.uk/itm/251379277920


 
  
 Are you using the 1965 6N8S as a driver tube?


----------



## Artsi

gibosi said:


> Are you using the 1965 6N8S as a driver tube?



 

Nearly all time i have been listening with this amp i have used pair of 6N8S '65 as drivers. Also listened some time with sylvania 6SN7GTA's. Those are pretty good too.


----------



## gibosi

6SN7 update:
  
 After spending tons of time researching 6SN7 tubes, it appeared that the Tung-Sol White Label 6SN7GT (1940-50s vintage) and the CBS/Hytron White Label 6SN7GT were the best of the middle tier tubes and were also very affordable, and based on my experience with these tubes, I would agree. Both have the virtue of doing nothing wrong. Both have a balanced FR from top to bottom, as well as a spacious 3-d stage with very good clarity and transparency. 
  
 The CBS/Hytron is very smooth and airy, but a bit soft. The bass is adequate, but doesn't have the punch or detail of better tubes. Even so, it is a very good sounding tube. It is my understanding that the most desirable CBS/Hytrons have white labels, as the red labels are said to be rebadged GE.
  




  
 The 1940 through 1950s white label Tung-Sol with gray plates has the nickname, "Mouse Ears" due to the round mica spaces attached to the top mica. Over the years, the round ears were replaced by rectangular ears, and in later tubes, the ears were eliminated. From reports I have read, the shape of the ears, or lack thereof, has no effect on the sound, and they all sound the same. I found this tube to have better bass than the Hytron, with better detail. In my opinion the Tung Sol is the better tube.
  
 Round "Mouse Ears"
  

  
 No "Mouse Ears"
  




  
  
 Therefore, the Tung Sol is the tube I recommend to those of you who are just now getting up to speed with the 6SN7. Like the Orange Globe, it serves as a credible benchmark. It is the tube to beat. It is good enough, that many feel no need to get something better. And at any rate, it is excellent introduction to the 6SN7.


----------



## gibosi

artsi said:


> gibosi said:
> 
> 
> > Are you using the 1965 6N8S as a driver tube?
> ...


 
  
 Thanks! I think I will get one. However, I have two more 6SN7s on their way to me, another Tung Sol and my first Sylvania, plus I have two E80CC on their way, so will likely hold off a bit.


----------



## vic2vic

gibosi said:


> 6SN7 update:
> 
> 
> Therefore, the Tung Sol is the tube I recommend to those of you who are just now getting up to speed with the 6SN7. Like the Orange Globe, it serves as a credible benchmark. It is the tube to beat. It is good enough, that many feel no need to get something better. And at any rate, it is excellent introduction to the 6SN7.


 
  
 Sorry for asking, as I thought it was probably mentioned some pages ago: do the 6SN7 (as driver tubes) need a separate power supply for the heaters (6.3V) ?
 And what about the heathers power supply for the 6H9C ?
 Thanks


----------



## gibosi

vic2vic said:


> Sorry for asking, as I thought it was probably mentioned some pages ago: do the 6SN7 (as driver tubes) need a separate power supply for the heaters (6.3V) ?
> And what about the heathers power supply for the 6H9C ?
> Thanks


 
  
 Yes, the 6SN7 heaters draw 6.3 volts / 600ma, so an external power supply is recommended.  The Russian equivalent to the 6SN7 is the 6N8S, whereas, the 6H9C is the Russian equivalent to the 6SL7. These tubes draw 6.3 volts / 300ma, and therefore, the LD can handle them fine.


----------



## mordy

Hi Gibosi,
  
 "Therefore, the Tung Sol is the tube I recommend to those of you who are just now getting up to speed with the 6SN7. Like the Orange Globe, it serves as a credible benchmark. It is the tube to beat. It is good enough, that many feel no need to get something better. And at any rate, it is excellent introduction to the 6SN7."
  
 Funny, this is how I feel about the Sylvania (Crosley) 6SL7 tube that I have. I still have not tried the 6SN7 tubes I have waiting (TS, Raytheon, Sylvania), because the voltage regulator did not yet arrive, so I cannot compare them yet.
  
 What are your thoughts about the difference between your favorite 6SN7 and the 6SL7 tubes you tried?
  
 Also, what are your thoughts on the differences between the 6SN7 and 6CG7/6CQ7 tubes, since they are supposed to be a successor to the 6SN7 tube?
  
 My questions pertain to using these tubes as driver tubes.


----------



## gibosi

mordy said:


> What are your thoughts about the difference between your favorite 6SN7 and the 6SL7 tubes you tried?
> 
> Also, what are your thoughts on the differences between the 6SN7 and 6CG7/6CQ7 tubes, since they are supposed to be a successor to the 6SN7 tube?
> 
> My questions pertain to using these tubes as driver tubes.


 
  
 I have the same questions for myself! lol But unfortunately, I simply have way too many tubes on hand (and more coming) and it will take me a while to sort through them all. My thinking was that since the 6SN7 universe can seem vast and confusing, I thought it might be helpful to initially focus in on a couple of entry-level tubes to help people get started once they have their external PS up and running.
  
 Next I want to get a better handle on how my other 6SN7 compare to each other and to my reference TS "mouse ears". And for sure, eventually, I hope to be able to get a better handle on the various 6CG7 and 6SL7 I have on hand..... all in good time....


----------



## nsixtyfour

Hi 
	

	
	
		
		

		
		
	


	



 I Need some help for buy the Voshkod 6ZH1P-EV for my LD MKII.
 Could you tell me if these tubes or these are the same as the 6ZH1P-EV seen in this guide ?
 Thanks,
  
 Aurélien


----------



## gibosi

nsixtyfour said:


> Hi
> 
> 
> 
> ...


 
  
 Yes, they are the same.
  
 I have purchased from this vendor:
  
 http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=130436695928&ssPageName=ADME:L:OC:US:3160
  
 $3 US Dollars for a pair plus shipping.


----------



## gibosi

Received two adapters today: Loctal to 6CG7/6DJ8 and Octal to 6CG7/6DJ8. For me, these adapters offer two significant advantages over my 6SN7 to 12AU7 adapter.
  
 First, I don't have to reconfigure my socket to run octals and loctals and this allows me to much more easily swap out a 6CG7 or an E88CC for a 6SN7, for example.
  
 And second, I can use 12 volt Octals and Loctals simply by adjusting my external PS to 12.6 volts. This enables me to take advantage of the fact that the 12 volt versions are often significantly cheaper, for example, 12SN7 versus 6SN7. And similarly, if I want to run any 12A-7, again, all I have to do is increase the heater voltage.
  
 With the arrival of the Loctal to 6CG7 adapter today, I was finally able to test out the 7AF7 and 7N7, and they both sound great!


----------



## nsixtyfour

Thank you gibosi,
 I was not sure because I wondered why yenaudio sell them 36 $ 
 Also, Can you tell me if there is a difference between the Mullard M8100 and the CV4010 ?


----------



## mordy

Hi G,
  
 Sounds great - could you post link where to buy the adapters?


----------



## gibosi

I bought them from Ayumi Studio:

http://www.ebay.com/itm/261365150027?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649


----------



## gibosi

1951 National Union 6SN7GT...
  
 A quick comparison with the mouse ears Tung-Sol. The NU has more bass presence and punch, a very smooth, liquid midrange, but less air. As one reviewer wrote:  "A bit dark, beautiful sound". I still prefer the Tung Sol, but this is a very good tube that just might shine in an otherwise bright system.


----------



## Nic Rhodes

nsixtyfour said:


> I was not sure because I wondered why yenaudio sell them 36 $
> Also, Can you tell me if there is a difference between the Mullard M8100 and the CV4010 ?


 
  
 Technically there should be minor differences, in reality many are dual badged and the diffierences are not really worth bothering about. They are so close then the differences are mostly ignored anyway in the less pedantic times.


----------



## Oskari

nic rhodes said:


> Technically there should be minor differences, in reality many are dual badged and the diffierences are not really worth bothering about. They are so close then the differences are mostly ignored anyway in the less pedantic times.


 
  
 Why _should_ there be minor differences and what would those minor differences be?


----------



## Nic Rhodes

just the differences in the two spec sheets, the CV4010 earlier largely from 1957  (on my sheets but believe is the valves was 1948 originally) and the M8100 from 1960 revised 1963 on my copies. As I said earlier I don't see a difference personally between the two valves and neither did the makers with many cross marking of these valves but the spec sheets do show differences in the originals though very minor and not worh bothering about as I said earlier. It is not worth worrying about. The two are interchangeable for the coarse operation we have here as opposed to the high vibration / shock / noise environment they were often aimed at back in 1960.


----------



## Oskari

I think it is a single type (with the internal type code 59). The CV sheet tells what the government required and the other sheet what Mullard felt comfortable promising other customers.


----------



## Nic Rhodes

Either way it is largely irrelevant for use in LD. They both will work and appear to be the same in the LD.


----------



## gibosi

7N7 Loctal (Electrically equivalent to 6SN7)
  

  
  
 From what I have read and seen, almost all the 7N7 were manufactured by Sylvania. The only other manufacturer I am aware of was National Union, and their tubes, with gray smoked glass are easily identified. So if you see a clear glass tube with a chrome top, it is almost certainly a Sylvania, regardless of how it is labeled. I have seen two variations, a tall bottle and a short bottle. However, I do not know how they differ.
  
 While I don't have a 1950s short-bottle chrome-top Sylvania 6SN7GT, the reviews I have read suggest to me that the 7N7 is very similar, if not identical. This tube has a very good high end and a strong tight bass. Mids are more forward and aggressive than the mouse ears Tung-Sol, but in exchange, this tube has very good detail and imaging. These are often very cheap and an excellent buy.


----------



## TrollDragon

Well I found the schematic for the old console carcass I acquired a while back.
  
 Going to repurpose some of this into a little 2W amp for headphone and speaker use. I am going to use one of my 5751's to replace the bad 12AX7 that was in it. It has two 6GW8 / ECL86 power tubes the 12AX7 was the driver and a 6CA4 / EZ81 rectifier.
  

 Going to relocate the transformers and the AF board to a smaller chassis. Something nice to tinker with over the cold months.


----------



## mordy

Hi TD,
  
 Any update on the power protection circuit so that you can use the LD amp with DC coupled amps?


----------



## gibosi

1945 RCA VT-231/6SN7GT with grey glass
  

  
 This is one of my favorite tubes. It is simply grand and smooth, with good bass, an incredible midrange, and pretty good detail and highs. The tonality of this tube is just right. Vocals, piano, horns sound spot on, very musical. And then there is this huge spacious 3-D sound stage.
  
 I have come to believe that the 6SN7 family is just as good as the 6DJ8 family of tubes, but different. The 6DJ8 is cooler with great detail. The 6SN7 is warmer with more musicality and a palpable 3-D soundstage. Both are excellent but again, they are different.
  
 It appears to me that great detail and coolness go together. As the sound becomes warmer, the reverberation masks some of the lowest level details. But in exchange for the loss of some detail, the extra warmth adds more musicality and a spacious 3-D soundstage. So for the most part, the 6SN7 is not for detail freaks. But speaking for myself, musicality and a spacious soundstage are more desirable than ultimate detail.
  
 Coming back to the RCA, I believe it strikes an exquisite balance between warmth and detail. And in my opinion, this belongs in the collection of everyone who wishes to explore the 6SN7 tubes. RCA manufactured this tube from 1942 through the mid 1950s, and the general consensus is that the 1940's production are the ones to get.
  
 In conclusion, of the four 6SN7 -- CBS/Hytron, National Union, Tung-Sol "mouse ears" and the RCA -- I recommend the Tung Sol and the RCA as worthy additions to your collection. I have two more coming, another Tung Sol with round plates and black glass, and a Sylvania "Bad Boy". These have received very good reviews and I am looking forward to their arrival.


----------



## gibosi

In today's mail I received two 6NS7 I have been eagerly anticipating: Tung Sol VT-231/6SN7GT and a Sylvania 6SN7GT "Bad Boy."
  
 The 1948 Tung-Sol with round black plates and black smoked glass is labeled Emerson. The vendor seemed not to realize it was a Tung Sol and I was able to get it for around $50.00. While $50 is certainly not cheap, this tube is considered one of the best 6SN7 and usually goes for $100 and up.
  
 The Sylvania Bad Boy with 3-hole black T-plates, bottom getter, manufactured in 1952 is another highly ranked tube. I managed to get this tube for around $20.00. As it usually goes for $60 and up, a pretty good deal I think.


----------



## TrollDragon

mordy said:


> Hi TD,
> 
> Any update on the power protection circuit so that you can use the LD amp with DC coupled amps?


Hi mordy!
I just emailed him for a status update.


----------



## ForShure

Hey all, I'm new to this forum and to tube amps as well but since you guys have experience poking around inside these amps I figured here would be a good place to start. I got a little dot mkII for Christmas and it has been working for the past month but now it has a strange buzzing sound in the left channel. Even with I unplug all my other components I can still hear the noise. I tried moving around the power tubes and headphone tubes but the sound still stays in the left channel. I was wondering if you guys had any other suggestions on how to make the noise go away so I can enjoy my amp again.


----------



## hypnos1

Well folks, I think I may just have found _my_ endgame tube(s) at long last, and I'm afraid it's ciao to the 6DJ8s - never thought that would happen! Even my beloved Tesla E88ccs (gold pins _and_ grids) have been blown out of the water...by the Siemens C3gs I have finally managed to complete the adapters for - they are an 8-pin pentode (can be triode connected) with different pin-out, of course, to the 6AK5.
  
 Apparently they were conceived by some VERY demanding engineers, wanting _uber_ low distortion, microphonics, noise etc etc but with high gain, linearity and very long life. All I can say is they worked miracles, because they have not only filled the slight gaps in the otherwise excellent Teslas, but also surpass them in ALL areas - given my equipment and ears, of course.
  
 Bass is phenomenal, in detail and extension (_slam_ is too crude a word to apply to these beauties).
 Treble ditto, without the occasional sibilance of the Teslas.
 Mids have returned nicely, with no loss in the other frequencies - in fact no range dominates to the detriment of others.
 Soundstage is truly remarkable - a magic trick that manages to achieve the 3-dimensionality of the Teslas with even _more_ detail...a rare ability I would suspect.
 Imaging is precise, along with instrument and voice positioning/separation. Vocals are slightly more forward than the T's, giving a slightly more intimate musical experience while retaining a fine overall balance.
 The tonal range is immense, along with dynamic range - from attack thru decay, instruments are taking on a whole new (magical) persona.
  
 And the low noise/high linearity pre-requisites are manifested by the _dead_ silence in a 'black' background, and a deliciously 'clean' sound of wonderful clarity.
  
 In other words, I am totally blown away, in case you hadn't guessed!
  
 Perhaps my (obsessive) desire to keep to a minimum the number of in-line connections and mix of metals may have also helped somewhat...in line with my previous mods, I decided to use pure silver wire for fitting tube to LD socket - in fact I bit the bullet and did away with an adapter as such and connected (scarily!) 1mm wire direct to the tube pins, said wire also acting as the B7 pins, instead of a cut-away tube base. Sealing things in resin to (hopefully) prevent connections becoming DISconnected meant I only really had one chance to get things right...a bit of a nightmare, to say the least!
 Anyway, thankfully all was well (so far) and the final result has proved to be worth every ounce of sweat and nervous exhaustion.
 This 'pentode' certainly seems like no other, and would explain Yamamoto's choice of the C3 family for some of his lovely amps...
  
 :
  
  
 The above, of course, is NOT the right photo -  (don't know how to remove it!). Hopefully second time lucky...
  
 That's more like it!!


----------



## mab1376

> Originally Posted by *hypnos1*


 
  
 I'm a little behind on this thread, whats going on with your headphone jack there?
  
 also congrats on getting those tubes working! I'm no too handy, but hopefully I can get a change to try them somehow down the road if i can find a pair and build adapters which I'm hoping is in the thread somewhere. I'm still using 6AV6 tubes a pretty pleased with them overall.
  
 Also a quick google on that tube shows an "S" versions with tighter specs, is that the on you're using?
  
 Again congrats, and happy listening!


----------



## CollectoR13

Hi! 
Where did you get those siemens C3gs from? 
They seem to be very rare...


----------



## hypnos1

mab1376 said:


> I'm a little behind on this thread, whats going on with your headphone jack there?
> 
> also congrats on getting those tubes working! I'm no too handy, but hopefully I can get a change to try them somehow down the road if i can find a pair and build adapters which I'm hoping is in the thread somewhere. I'm still using 6AV6 tubes a pretty pleased with them overall.
> 
> ...


 
  
 Welcome back mab. Boy have you got some catching up to do! And thanks for your encouraging comments...
  
 Things have moved on at a frantic pace since 6AV6 land. First we found 6HM5s (TALL bottle type, mine being from Ei Yugoslavia, at 5$ with free shipping) which are simply plug & play on EF95 setting, and which were very good indeed.
 Then came double triode land - the 6DJ8 (and variations) land - with a leap in results.
 Then came octal land, also with some really good results...you really must burn the midnight oil and go back over the work of such as Audiofanboy and Gibosi _et al_.
  
 As for myself, my foray into 8-pin land has just been with the C3g pentode/come triode - mine being the 'ordinary', but still with the dual getters (1 barium and 1 zirconium). The "S" versions are out of my price range, and to be honest these 'ordinary' ones are so well made and sound so fantastic that I doubt very much whether the (much) greater cost of the Ss is warranted.
  
 You will find posts showing different adapters, going back a while, but for the C3g I had to do my own mod from 8 to 7-pin, with different layout .
  
 As for the headphone jack...it's gone!! After getting amazing results from wiring my (pure silver) speaker wire direct to the speaker's crossover (I HATE too many connections in the signal/power path), I thought I would do away with the "upgraded" Neutrik jack socket - which I was not at all impressed with - and solder the headphone cable (again pure silver wire) direct to the PCB. And I was VERY pleased with the results. Mind you, it is not so convenient of course for trying different headphones! And I still haven't checked to see whether that prevents the LD from outputting as a preamp...but as neither of these things bothers me (at present) I am enjoying the added sonic benefits.
  
 Good luck with your catching up, and hope to see your own findings appearing here very soon. The guys here (as you know) will be only too glad to help you with any queries/problems you may encounter...
  
 So, happy rolling mab!


----------



## hypnos1

collector13 said:


> Hi!
> Where did you get those siemens C3gs from?
> They seem to be very rare...


 

 Hi Collecto.
  
 Got them from ebayer emsstrom in Germany - but can't see them listed now (he didn't have very many). Yep, there ain't many about, to be sure! JAC Music has them listed, but they're not cheap (mind you, premier 6DJ8s can be a lot dearer lol!)


----------



## mordy

Hi Hypnos 1,
  
 Congratulations to your C3g amp mod! If I were to use an adapter, what would I use? I have two setups - one for 12AX7 and one 6DJ8.
  
 What are you using for power tubes?
  
  
 Hi Collecto13,
  
 Could only find one offering on Ebay - bidding is up to $69 for the pair. Selling prices for the past month on Ebay have been between $50 - 70/pair.
  
 Here is a link to a source that has a lot of these tubes - prices range from Euro 26 to 175, with over ten varieties (don't know how much shipping is):
  
 http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&ved=0CC0QFjAA&url=http%3A%2F%2Fjacmusic.com%2Fhtml%2Forder%2Fjacmusic-pricelist.pdf&ei=fafVUueTJpfNsQT-qoKQDg&usg=AFQjCNGj-lDYSfbgmLr6l8a8-rgaK9sCzw&sig2=UYz7_5nSDdipqfHkdlIxCA&bvm=bv.59378465,d.cWc
  
 These tubes were used by the German government for long distance intercontinental phone calls and were produced without any compromises; hence the ultra high quality.


----------



## Audiofanboy

hypnos1 said:


> Well folks, I think I may just have found _my_ endgame tube(s) at long last, and I'm afraid it's ciao to the 6DJ8s - never thought that would happen! Even my beloved Tesla E88ccs (gold pins _and_ grids) have been blown out of the water...by the Siemens C3gs I have finally managed to complete the adapters for - they are an 8-pin pentode (can be triode connected) with different pin-out, of course, to the 6AK5.
> 
> Apparently they were conceived by some VERY demanding engineers, wanting _uber_ low distortion, microphonics, noise etc etc but with high gain, linearity and very long life. All I can say is they worked miracles, because they have not only filled the slight gaps in the otherwise excellent Teslas, but also surpass them in ALL areas - given my equipment and ears, of course.
> 
> ...


 
 Great stuff man! I knew these C3g were worth trying!
  
 As usual, how I would _love_ to be able to directly compare the best 6DJ8 to the best 6SN7 to the best C3g to the best... But, alas, I can't... More like, no one has yet really; except maybe gibosi who's been pretty thorough in comparing the 6DJ8 and 6SN7 types (and other exotic suggestions like the 2C51...).
  
 Too many tubes to test, too many adapters to make, so little time and money lol...
  
 Anyway, great work! I'm sure you'll be copied and that more people will jump the boat!


----------



## TrollDragon

Well now have a totally hum free octal adapter for the 6DJ8 platform.

  
 Took an incompatible B9A and cut the bottom off of it with the Dremel and a cutting disc. I wrapped painters tape around the top and bottom, leaving a gap between the two tape pieces as a guide for the disc. If you take your time and go slowly the bottom of the tubes should come off cleanly. Pull the tube innards out and cut off the pin wires long enough to solder to. The pin wires will need to be scrapped and cleaned up a bit so they will take solder. I like to use a just little plumbers flux as it is more corrosive and cleans the pin wires better.
  
 Soldered some short pieces of wire to the pins and put heat shrink over the solder joints. Then fill the tube base with hot glue so nothing moves, when that cools enough place the octal socket over top of the assembly pulling the wires out to the side of the pins in the correct spots. Since it would be too hard to tin and strip the wire before hand i just left them all 2" long. The octal sockets I have are machined ceramic and have straight pins for mounting to a PCB. So I pushed the octal pins down into the hot glue and proceeded to cut off strip and solder the wires to the pins. (It's a little tedious but doable.)
  
 After all the wires were attached I filled the rest of the space with hot glue and molded it smooth and round with the flat part of the nozzle on the glue gun. Let it cool, plug in an octal and see if the filaments light up. If they do then test with disposable headphones in case you made a mistake in the wiring. 
	

	
	
		
		

		
			




  
 I plugged in the 6H9C as they are the only octals I have and proceeded to check out some OM.
  

*"Hayya ala salah. From the minaret see.
 Toward solidaric ground. Weeps - walk on sadhak."*
  
 The bass on this song is great and listening with the GMP 8.300's was total enjoyment from the 6H9C.

 Enjoy!


----------



## mab1376

Hypnos1,
  
 Did you try and other C3g brands with negative results? or did your research just point you to the Siemens?


----------



## hypnos1

mordy said:


> Hi Hypnos 1,
> 
> Congratulations to your C3g amp mod! If I were to use an adapter, what would I use? I have two setups - one for 12AX7 and one 6DJ8.
> 
> What are you using for power tubes?


 
  
 Hi mordy.
  
 Thanks for your kind words. As for adapter, since the pin layout is different to anything else we have been using, you may as well do what I did and make your own. Unlike me, however, you might prefer to use octal sockets in a way similar to TrollDragon, but direct to a B7 base - either using a cut away base from an old tube, or as I did, using solid core wire through a circle of strong plastic (or similar), letting the wire act as the B7 pins. Of course, the innards need sealing in resin/hot glue/whatever, and GREAT care is needed to ensure correct pin to pin placement - mirror images are a bane, to say the least! (Sorry if I'm "telling Grandma how to suck eggs", but I still get a bit confused sometimes, no matter how careful I am!!..). Because of limited space, I used _bare_ wire for bending hither and thither, and of course had to be EXTREMELY careful to ensure nice gaps between them. So all in all, not _too_ difficult, but it needs careful planning, a fairly steady hand, patience and careful checking and double checking. And as TD mentioned, it's a good idea to test with an old pair of 'phones first, _just_ in case...
 Anyway, good luck if you do decide to go ahead...
  
 As for power tubes, I have the (extremely) expensive 6N30P-DRs, which do seem to have the edge over others - and Audiofanboy loves 'em, which is good enough for me!
  
 Oops, time has slipped away, so I'll post the C3g pin layout tomorrow...


----------



## hypnos1

mab1376 said:


> Hypnos1,
> 
> Did you try and other C3g brands with negative results? or did your research just point you to the Siemens?


 
  
 Hi mab.
  
 Actually, the Siemens were the only ones I could find at a reasonable cost - the other brands only seeming to be available from JAC Music at FAR higher prices. And as Yamamoto uses Siemens tubes, I thought they would be _more_ than good enough for me! And they have certainly proved themselves to be so...
  
 Ah well, time for supper once more...
  
 Cheers!


----------



## superdux

i have 2 questions for you "tech" guys:
  
 1. what would actually be the worst to happen to my headphones if i did something wrong in using a selfmade adapter?
 2. whats a "surge" and how can that affect my amp? Especially concerning a 12AX7 to 6SL7 and an octal tube?
  
 thx for replys


----------



## TrollDragon

Hey superdux!

1. Smoke would roll from your headphones, the amp or both... Test with cheap headphones.

2. I don't understand the question.


----------



## superdux

hi Trolldragon,
  
 with surge i meant an overflow of electric energy in the amps circuitry. Mikelap said it had something to do with the milliamps a tube needs to run and that must be under 400ma in the LDMKIII if i remember correctly.(especially using octals with an adapter)
 So using my planar headphones (T50RP), which need considerably more energy to be driven would a risk of a surge overpowering the amp be more there?
  
 Sorry i´m not that good in english as i speak german most the time.


----------



## TrollDragon

Guten Abend Herr superdux!

The surge would not be from any amount of current draw that a headphone would place on the amplifier.

The power transformer in the Little Dot is limited to 500 ma per side on the driver tubes as far as we can tell. There is no documentation on this transformer as it is a custom one made for Little Dot. The gauge of the driver filament wires and the label on the transformer reads basically 1A / 2, so we agreed that the maximum of 500 ma per tube would be the rating.

Like MIKELAP has said to you if you keep your dual triodes (9 pin or octal) to a max of 400 ma you should have no problems.

If you want to run higher current tubes like the 6SN7 then you should set up an external filament power source like the other members here use.


----------



## superdux

Thx Trolldragon,
  
 i get the point.Thank you for your advice


----------



## Artsi

Sorry to bother you serious little dot tube rollers with my posting.
  
 C3g tubes could be the best of the best for single triode powertube driving. 6A6 tubes are also very good sounding drivers. Curve tracer lines look very good for 6A6. http://vinylsavor.blogspot.fi/2013/02/tube-of-month-6a6.html It should be possible to drive both channels with 6A6. Only one cathode connection, so there is very tiny channel separation leakage. Heater is 0.8A! With my pan-amp i use 6A6 this way and it is impossible to hear channel leakage in normal listening.
  
 I have been planning hardly my next DIY amp. Twice i nearly have ordered parts and at the last moment cancelled order. I want to use 6X5 as full wave rectifier. 6N6P's could be good powertubes. But should i use one octal socket for driver, and then i could roll nearly all my octals and with adapters 9-pin miniatyres. Or should i use two miniatyre double triodes to drive and forget mostly tube rolling with that amp. I can't decide... Somehow i think that amp sounds better with 2 triodes driving one channel.
  
 Got more 6N8S tubes from 50's. Got one from 55' and it seems that there is some differences in structure if comparing to newer versions.

 Getter is different in 50's to 65' with square getter. And this 55' does not have flat plates like all others and there is additional tin plates from lower mica.
  
This headphone tube amp thing is really going to get out of hand. If i don't buy more tubes, then i build more amps...


----------



## hypnos1

Audiofanboy.
  
  Yep, you certainly were right to throw C3gs into the mix, after gibosi's related findings. My heartfelt thanks go to you both; Yamamoto, and JAC Music for pushing me in that direction. Even straight out of the box they were amazing, and now with a good few hours on them I still cannot believe what they have done for this modest not-so-little amp (ie the MKIV SE).
 While I am giving thanks, I for one would also like to say _grazie_ to the founder of this thread - Dept of Alchemy - and Acapella 11, who contributed so much to this thread and is sorely missed (where are you now?!). I would have loved to hear their views on what has been achieved these past months. Thanks also to all the other regulars, who have made this thread such an education AND joy (not to mention the "tube-roller widow" indoors!!)...
  
 Mordy, and anyone else interested, here is the pin layout for said C3g :
  
                      C3g               6AK5(et al)
                     
                      Pin                Pin
  
                     1&8 - H         3&4 - H
                        2  - G3(s)    
                        3  - P            5   - P
                        4  - G2(s)     6   - G2(s)
                        5  - K            2   - K,G3(s)
                        6  - G1(s)     1   - G1
                        7  - K            7  - K,G3(s)
  
 As advised by gibosi, I linked C3g pins 2 & 7, to eliminate a floating grid.
  
 Having connected all corresponding pins, everything is working perfectly (so far!) and trust there shouldn't be any nasty surprises further down the road...
  
 Cheers everyone, and happy rolling...


----------



## mordy

Hi Gibosi,
  
 Finally got my voltage regulator after waiting exactly a full month. I am using your post on page 295 as a guide, but my amp is silent - cannot coax any sound out of it.
  
 My wiring is according to the diagram on p 253 for 12AX7 tubes. With this I have an octal adapter, and everything was fine and worked beautifully.
  
 On your thread on p 295 you say to disconnect the wires currently connecting *Vector pins 3 and 4* to the 9 pin socket pins 4 and 5, and then tape them up for future use.
  
 Now, according to the schematic, 9 pin socket* wires 4 and 5 for the heater are both connected to 3 on the right LD socket.* Disconnecting these two wires from 3 on the Vector,  and connecting the external voltage source, results in silence.
  
 What should I do with Vector wire 4 that goes to pin 9 on the 9 pin socket?
  
 Could it be that the schematic you presented is for 6DJ8 tubes? What do I have to do to enable the 12AX7 setup plus the octal adapter that it should work with an external voltage source?
  
 I have six 6SN7 tubes waiting to sing, and wish I could listen to them. Can anybody explain how to wire the external voltage source for the wiring of a 12AX7 with octal socket?


----------



## dxanex

Just passing this along, if anyone may be looking for a pair of Voskhod 6ZH1P-EV or Tung-Sol EF95 I'm selling some extras that I don't need...
  
 http://www.head-fi.org/t/700730/fs-voskhod-6zh1p-ev-rockets-and-tung-sol-ef95-for-little-dot-darkvoice-6ak5-5654w-ef95


----------



## gibosi

mordy said:


> Hi Gibosi,
> 
> My wiring is according to the diagram on p 253 for 12AX7 tubes. With this I have an octal adapter, and everything was fine and worked beautifully.
> 
> ...


 
  
 Since your adapter is 6SN7 on top and 12AX7 on the bottom, then you simply need to swap the vector wires with the voltage regulator wires. Pins 4 and 5 on your socket remain bridged and then connect one of the voltage regulator wires to either pin 4 or pin 5. Next, connect the other voltage regulator wire to pin 9 on the socket. Thus your 9-pin socket is configured in the 6-volt 12AX7 configuration, and all you have done is to replace the vector heater connections with voltage regulator connections.


----------



## mordy

Hi Gibosi,
  
 Many thanks for the wiring instructions. It took a little trial and error, but I am finally listening to a 6SN7GTB 1957 Tung Sol tube now. Too early for listening impressions (or too late; it's after1.00 AM LOL).
  
 Here is a picture of work in progress. Colorful spiderweb, conflicting measurements, left over old laptop power supply (?), scrap pieces of wood and foam. Pretty? No, but it works!
  

 This is real! Thanks again for the help!


----------



## gibosi

Mordy,
  
 Glad to see that you have arrived in 6SN7 land! 
  
 And to all of those who have mated their LD with an external heater PS, another 600ma tube that might be worth trying is the ECC40. However, it is an 8-pin miniature and thus will require an adapter -- ECC40 to 61N/6DJ8 or ECC40 to 12A-7.


----------



## mordy

Hi Gibosi,
  
 So far all is well. Tried four 6SN7 tubes so far; a Tung Sol '57 tall bottle, Tung Sol short bottle from '54, Raytheon US Navy unknown year, and a Sylvania '52 chrome top. All of them sound very good with the exception of the Raytheon, which sounds old and tired and restricted in the treble and bass.  The Sylvania has a great amount of detail.  However, need more time to come to a clearer impression of each tube.
  
 I have a bunch of 6CG7/6FQ6 tubes that I first tried as power tubes but decided that they are not suitable for that.
  
*Plugged in one 6CG7 in the the 12AX7 setup but only silence. I have a second setup for 6DJ8 tubes. Could I use this setup for the 6CG7 tubes? How should I hook up the wires?*
  
 Sorry for bothering you again, but I am not good at figuring out these things.
  
 Thanks again for all your help.


----------



## gibosi

To use the 6CG7, it is plug and play in a 6DJ8 socket (with your external PS).


----------



## mordy

Hi G,
  
 To the rescue again - works fine. Using Raytheon Japan 6CG7/6FQ7 tube to begin with. Thanks again!


----------



## kvtaco17

mordy said:


> Hi G,
> 
> To the rescue again - works fine. Using Raytheon Japan 6CG7/6FQ7 tube to begin with. Thanks again!


 

 I just received my US Raytheon, and I'm loving it so far!


----------



## gibosi

I really like the US-made Raytheon 6CG7 too. 
  
 However, today, a 1961 Heerlen-made E80CC (VB8 delta1A1) arrived. As this tube is very similar to a 12AU7, I disconnected pins 8 and 9 on my 6DJ8-configured socket (if I left them connected, it buzzed), adjusted the heater voltage up to 12.6 and it sounds great!


----------



## kvtaco17

gibosi said:


> I really like the US-made Raytheon 6CG7 too.
> 
> However, today, a 1961 Heerlen-made E80CC (VB8 delta1A1) arrived. As this tube is very similar to a 12AU7, I disconnected pins 8 and 9 on my 6DJ8-configured socket (if I left them connected, it buzzed), adjusted the heater voltage up to 12.6 and it sounds great!


 
 You know your just enabling me...lol
  
 I'll get to them when I get comfortable with these... I love how these sound... the massive, detailed sound stage... the great dynamics, and even with the extended treble they never sound harsh.


----------



## gibosi

kvtaco17 said:


> You know your just enabling me...lol


 
  
 I'm just doing my job! lol


----------



## Audiofanboy

gibosi said:


> I really like the US-made Raytheon 6CG7 too.
> 
> However, today, a 1961 Heerlen-made E80CC (VB8 delta1A1) arrived. As this tube is very similar to a 12AU7, I disconnected pins 8 and 9 on my 6DJ8-configured socket (if I left them connected, it buzzed), adjusted the heater voltage up to 12.6 and it sounds great!


 
  
 Great work, gibosi! One more tube type tested on our LDs! I feel like I'm almost being left behind at this point lol, with my barely rigged MK IV that _only_ has a 6DJ8 tube mounted on a _basic_ adapter...
  
 I wonder what David Zhezhe would think about all this lol... It really would be great if they came up with a MK III / IV that uses a single B9A tube as a driver; just to make it easier to adapt tubes...


----------



## gibosi

audiofanboy said:


> Great work, gibosi! One more tube type tested on our LDs!


 
  
 It is really great to have a configurable socket and an external heater PS. The universe of possible tubes has grown much larger than before. But to be frank, I am feeling a bit overwhelmed with all the tubes I have, so will let this E80CC run for a few hours, just to make sure there is nothing wrong with it, and then will put it aside, along with the 6FW8, 7AF7 and the others. I think I need to stop buying new tubes for awhile and just work through this rather large pile that I have already accumulated. 
  
 For now, I want to get to know the Tung Sol RBP and the Sylvania Bad Boy better. After a only a few hours, both impress me as mighty fine tubes. So I want to take some time to become more familiar with their sound and then try to write up my impressions and observations.
  


Spoiler: Tubes


----------



## kvtaco17

http://www.duncanamps.com/tdslpe/
  
 something we can use as a reference for pin compatible tubes...


----------



## gibosi

gibosi said:


> However, today, a 1961 Heerlen-made E80CC (VB8 delta1A1) arrived. As this tube is very similar to a 12AU7, I disconnected pins 8 and 9 on my 6DJ8-configured socket (if I left them connected, it buzzed), adjusted the heater voltage up to 12.6 and it sounds great!


 
  
 A picture... E80CC and E88CC, both Heerlen-made in 1961. The E80CC is tall!


----------



## mordy

Hi Gibosi and kvtaco17,
  
 Having spent a little more time with the Japanese Raytheon 6GC7/6FQ7 I must say that it grows on you. After spending time listening to a 1953 Tung Sol 6SN7GTB tube you have to adjust to next tube type - it takes a little time to get a settled opinion. While the TS 6SN7 is more musical and has a round fat bass, the Jap Raytheon is more detailed with a gorgeous wide forward sound stage with a fantastic timbre and exquisite high end and clarity, although the bass is not as tactile. Both tubes are really excellent.
  
 Again, these are early impressions, subject to change. But, the wow factor is there...Man, I just smelled the breath of the trumpet player I am listening to LOL!
  

  
  
 Thanks to Oskari  (remember the mystery of Siemens Foreign tubes?) we now know that Raytheon had ties with Toshiba and that they used Philips sourced manufacturing equipment. The tube could also have been made by Hitachi.
  
 Anyhow, I got this little bargain voltage regulator with a digital readout. There were many sellers of what looked like the same item, so I picked one seller of several who had the same low price of $4.33 incl. shipping. I picked a company with over 100.000 feedbacks and well rated. Unfortunately the shipping took a full 30 days, which I feel is too long. I have gotten stuff from China in 5 days, but usually it takes around 14 days. Maybe the end of year volume slows things down.
  
 The voltage regulator is adjusted with a little brass screw, but I cannot adjust it exactly. Either I get 6.27V or 6.43V - nothing in between. Checking the voltage with my Sears multitester I get a readout of 6.30V when the voltage regulator reads 6.27V.
  
 Which value should I trust? (The Sears tester is a cheap $20 unit)
  
 Happy tube rolling!


----------



## mordy

Hi Gibosi,
  
 When listening at normal levels I cannot hear much of buzzing or humming, but turning it up very load there is a buzzing and a background hum.
  
 Grounding the voltage regulator took care of the buzzing, but the low level hum is still there. Could be from all the wires I have running to my receiver, because this hum is there when the Little Dot is shut off.
  
 Are you suggesting that I disconnect the socket pin 8-9 loop using the 6DJ8 setup for the 6CG7/6FQ7 tube?


----------



## kvtaco17

mordy said:


> Hi Gibosi,
> 
> When listening at normal levels I cannot hear much of buzzing or humming, but turning it up very load there is a buzzing and a background hum.
> 
> ...


 
 it very well could be caused by all of your wires everywhere... I have an identical setup except my wires are dressed in and they are in an enclosure... I have very little noise even when I have the volume up all the way with 32ohm cans.
  
 I'd trust your multimeter vs the integrated one... I noticed about a 10th or so difference between the integrated one and my fluke. And FYI I still have 8-9 connected still.
  
 I do agree that this tube does not have very weighty bass BUT it is more then enough for my tastes. It really is excellent in its timbre. I do love the high end detail and big sound stage, as well as the apparent quickness/clarity this tube posses.


----------



## TrollDragon

Hey kvtaco17

A Fluke you say... very nice which model?


----------



## kvtaco17

trolldragon said:


> Hey kvtaco17
> 
> A Fluke you say... very nice which model?


 
 I have 2 87's... one for work and a very old one with the old green LCD for personal use... they were both just calibrated courtesy of work lol


----------



## mordy

Hi kvtaco17,
  
_*"I do agree that this tube does not have very weighty bass BUT it is more then enough for my tastes. It really is excellent in its timbre. I do love the high end detail and big sound stage, as well as the apparent quickness/clarity this tube posses."*_
  
 Spot on - exactly my impression! As I am listening I became more aware of the quickness and clarity, just like you say.  Another plus of this tube; it will take away the sibilance from a sibilant recording and make it more pleasurable to listen to.
  
 I will go as far to say that this tube has the detail of a 6DJ8 and most of the warmth of a 6SN7 tube.
  
 I have some RCA, GE and Sylvania 6CG76FQ7 tubes to test as well. We'll see who is the winner....


----------



## gibosi

mordy said:


> When listening at normal levels I cannot hear much of buzzing or humming, but turning it up very load there is a buzzing and a background hum.
> 
> Grounding the voltage regulator took care of the buzzing, but the low level hum is still there. Could be from all the wires I have running to my receiver, because this hum is there when the Little Dot is shut off.
> 
> Are you suggesting that I disconnect the socket pin 8-9 loop using the 6DJ8 setup for the 6CG7/6FQ7 tube?


 
  
 If the hum is there when the LD is off, then I doubt that it has anything to do with your LD. I strongly suspect that it is receiver related.
  
 The only time I remove the connection between pins 8 and 9 is when I am running a 12A-7-type tube with 12.6 volt heaters. Some 6CG7/6FQ7 tubes have shields on pin 9 which should be connected to pin 8. In those tubes that don't have shields, pin 9 is not used (if you look at the base of the tube, you will see that pin 9 is open), so connecting pin 8 to pin 9 will make no difference. 
  
 I have loctal and octal adapters with 6DJ8/6CG7 on the bottom and I have used 12 volt octals and loctals, 12SN7, 14N7 and 14AF7, with pins 8 and 9 connected and experienced no problems. After all, the octals and loctals have only 8 pins, so pin 9 is not used.
  
 So if you are running a 12A-7-type tube at 12.6 volts in a socket configured for 6DJ8/6CG7, disconnect the shield. Otherwise, leave it connected.


----------



## mordy

Did not know that there is a market for empty tube boxes:
  
 http://www.ebay.com/itm/NOS-MULLARD-EMPTY-TUBE-BOXES-for-ECC83-12AX7-or-E88CC-/230919170412?pt=Guitar_Accessories&hash=item35c3dae96c
  
 What puzzles me is that there were 6 available and 4 sold.....$12 for an empty box?! Give me a break!  This must be a fluke!


----------



## TrollDragon

kvtaco17 said:


> I have 2 87's... one for work and a very old one with the old green LCD for personal use... they were both just calibrated courtesy of work lol


 

 Very nice that work calibrates your 87 for you. 
	

	
	
		
		

		
			




  
 I had an old Beckman TECH 310 back in the day when I was doing consumer electronics repair for Rat Shack... My father had a Fluke at his work as an industrial electrician, can't remember which model it was but I tried to get him to bring it home when he retired... 
	

	
	
		
		

		
		
	


	



  
 As for nice test gear, a while back I was changing a hard drive in a computer for a company that builds and operates underwater ROV's.
 On the workbench was a Fluke Scopemeter 190 and the other bench had a Tektronix TDS3034... "Can I just sit here and drool on these for a bit?"
  
 A used Scopemeter 125 would be an amazing thing to have but I settle for an 87V any day.


----------



## Oskari

mordy said:


> Having spent a little more time with the Japanese Raytheon 6GC7/6FQ7 I must say that it grows on you.
> 
> Thanks to Oskari  (remember the mystery of Siemens Foreign tubes?) we now know that Raytheon had ties with Toshiba and that they used Philips sourced manufacturing equipment. The tube could also have been made by Hitachi.


 
  
 I think it is a Hitachi 6FQ7.
  
 Rather Hitachi had ties with Raytheon and Matsush¡ta had ties with Philips.


----------



## kvtaco17

TrollDragon,

that's the least exotic of my tools... Like I have a midtronics, alber, meggar... The first two are battery testers and the last on tests strap resistance only. I also have a density meter for specific gravity readings... And lots of crimpers from the tiniest wire up to 750mcm... I get a lot of cool tools in my line of work... As a guardian of the internet lol


----------



## mordy

Hi,
  
 Gibosi: Thanks for the update on wiring. I have a whole bunch of tubes to check out, and I am trying to limit my purchases for the time being. If there are no specific advantages of loctals over octals sound-wise, I'll skip this option meanwhile. Tried to look for equivalent tubes in 8.4V and 12.6V but did not find any real bargains yet. (Maybe I did not look hard enough) Paid 99c + shipping for my Hitachi 6GC7/6FQ7 tube.
  
 Oskari: Thanks for your input. This Hitachi tube is very special. My impression was that Toshiba, Matsushiita and Hitachi all bought Philips machinery and equipment.  (I think Ei started with Philips stuff and later bought Telefunken machinery - it supposedly is sitting in an Eastern European  warehouse waiting for a buyer.)
  
 On another note I notice that there is a feeling that we have reached a level where people are satisfied and happy enough with the sound that they feel that there is no need to look further, be it a 6SN7, a 3Cg, a 6DJ8/9322/7308/ECC or 6CG7 tube.
  
 Or, am I wrong?
  
 "If good is good, isn't better better?"


----------



## gibosi

mordy said:


> On another note I notice that there is a feeling that we have reached a level where people are satisfied and happy enough with the sound that they feel that there is no need to look further, be it a 6SN7, a 3Cg, a 6DJ8/9322/7308/ECC or 6CG7 tube.
> 
> Or, am I wrong?
> 
> "If good is good, isn't better better?"


 
  
 I have not reached that point yet....  Perhaps it might be accurate to say that I have reached a level where I am satisfied and happy exploring the 6SN7GT, 7AF7, E80CC and 6DJ8/6922/7308 tube groups. 
  
 However, I cannot yet say, "My top 5 tubes are....."  
  
 Nor can I say, "From now on, I will only roll tubes from the following tube group(s)....."  
  
 Maybe in time.....  But I suspect that I will always wonder, "Is there is another great tube out there?"


----------



## TrollDragon

kvtaco17 said:


> TrollDragon,
> 
> that's the least exotic of my tools... Like I have a midtronics, alber, meggar... The first two are battery testers and the last on tests strap resistance only. I also have a density meter for specific gravity readings... And lots of crimpers from the tiniest wire up to 750mcm... I get a lot of cool tools in my line of work... As a guardian of the internet lol


 

 Very nice toys!
  
 I used to play with an old Megger when i was young, one kid would hang on to the alligator clips and another kid would crank the handle, the longer you could hold the clips the tougher you were.... The stupid things we did as kids.


----------



## kvtaco17

^lol nice!


----------



## tvrguy

Hello All,
  
 I have lurked on here for ages and joined last year.
 Have had many headphones in addition to some very high end gear since my teens.
 I am now in a condo and still have a very nice main system, but I find most of my critical listening is now done with headphones.
 I am using a Windows 7 system and play only flac files through a Schiit Gungnir feeding into a Little Dot MkIII ver. IV board.
 Pure silver litz wire interconnect between DAC and Amp. and then in to HD-650's with Mobius 2 cable.
 I have read  almost every page of this forum and have acquired many different paris of EF95 tubes. They all have their strengths and weaknesses.
 Many thanks to Dept_of_Alchemy for his original guide. He got me started. I am currently using Sovtek 6H30EB Power Tubes
 and have tried almost all of the EF95 tubes that he has listed. My favorites were Mullard 8100's and Voshkod 6ZH1P-EV's.
 I recently got a pair of Tesla 6F32's put together in 1956 and I must say that they blow away the former. A box of 10 for $40. (Nice Find)
 They have more extended,articulate bass, smoother,lusher mids and extended top end with No Sibilance.
 They also seem to give better spatial cues, sound stage and height. Anyone else with the same thoughts? 
 What else can I do the further tweek this system? I can tweek a Big system in many subtle ways but need help with this stuff.
 I have no intentions of changing anything, the sound is SO GOOD that I am at that point I was with my big system.
 Huge money in for very small gains, I studied power cords and then bought a custom made cord from a guy in the States.
 Put a 3 foot cord on the Little Dot only and Huge difference! Just thought I would throw this out to you guys and see what comes back?
 Can we get the First page of this Forum brought up to date by Dept. of Alchemy? Is he still around and active? 
 Can we fill in the "Red" areas?
 Waiting for some feedback.
  
 Steve.


----------



## rosgr63

gibosi said:


> Mordy,
> 
> Glad to see that you have arrived in 6SN7 land!
> 
> And to all of those who have mated their LD with an external heater PS, another 600ma tube that might be worth trying is the ECC40. However, it is an 8-pin miniature and thus will require an adapter -- ECC40 to 61N/6DJ8 or ECC40 to 12A-7.


 
  
 Pleased you enjoy the 6SN7.
  
 Those who use an octal base they can get/make 6CG7 to 6SN7 and ECC40 to 6SN7 adapters.
 The 2C51 are also nice to try with a 2C51 to 6SN7 adapter.
  
 Be careful with the ECC40 because the non original tube sockets need to be marked for the correct alignment.


----------



## mordy

Hi tvrguy,
  
 Is this the TVR you mean?




 For a very small investment you can get this level of performance by making an adapter and using 6SN7, 6CG7 or 6DJ8 tubes. Just be forewarned: After trying these types of tubes you will not be able to get back to your 6AK5 tubes.
  
 Imagine tubes that have mainly strengths and (almost) no weaknesses - it just becomes a a question of taste.


----------



## MIKELAP

mordy said:


> Hi tvrguy,
> 
> Is this the TVR you mean?
> 
> ...


 
 +1


----------



## tvrguy

Hi Mordy,
  
 I believe that is a Sagaris....Never made it into mass production. They only made a handful.
 Then TVR went bankrupt. No, I had a 1973 TVR 2500M that I restored.
 Had it for over 20 years.  How/Where do I get an adapter to use those other tubes?
 I have read on the forum that some guys made their own.
 Where can I buy them? That way I know I won't blow up my amp cause I screwed up.
 And which is the best one to buy...I like a tight controlled bottom end and imaging.
  
 Steve.


----------



## gibosi

rosgr63 said:


> Pleased you enjoy the 6SN7.
> 
> Those who use an octal base they can get/make 6CG7 to 6SN7 and ECC40 to 6SN7 adapters.
> The 2C51 are also nice to try with a 2C51 to 6SN7 adapter.
> ...


 
  
 rosgr63, welcome to Little Dot land. 
  
 By way of introduction, rosgr63 is the host of the "6SN7 Tube Addicts" forum, a real treasure-trove of information.
  
http://www.head-fi.org/t/479031/6sn7-tube-addicts


----------



## gibosi

tvrguy said:


> How/Where do I get an adapter to use those other tubes?
> I have read on the forum that some guys made their own.
> Where can I buy them? That way I know I won't blow up my amp cause I screwed up.
> And which is the best one to buy...I like a tight controlled bottom end and imaging.


 
  
 To my knowledge, pre-made adapters to allow the use of double triodes in an LD do not exist. Unfortunately, at this time, it is a DIY project. It isn't all that difficult or expensive, but it does require that you invest the necessary time to understand what you are doing. The best I can do is to recommend that you read over the last 100 pages, or so. And after that, if you decide to jump in, we are here to help.
  
 Cheers


----------



## mordy

Hi tvrguy,
  
 My favorite car was a 1992 Acura Integra even though it gave me a fair amount of trouble. Fit like a glove and made every errand an adventure to drive. Had it for 5-6 years.
  
  

 Anyhow, there is a write up on this thread on how to make a solder-less adapter for the Little Dot. Go to page 301, post #4507 for full instructions. (If you are handy, you could make your own adapter - there are many posts with pictures and ideas posted.)In addition, you will need a power supply. Any 15-24V wall wart or laptop PS will do. The next item you will need is a voltage regulator. Here is one; there are many others:




 This regulator costs less than $5.00. It is very easy to connect the voltage regulator.
  
 If there is an interest, I will post a pictorial guide how to connect the voltage regulator.
  
 Good luck!




 1973 TVR 2500M


----------



## superdux

tvrguy said:


> Where can I buy them? That way I know I won't blow up my amp cause I screwed up. And which is the best one to buy...I like a tight controlled bottom end and imaging.
> 
> Steve.


 
 I was lucky and bought an 12AX7 adapter from MIKELAP, which was excellent craftsmanship. It also works with 6SL7 octal tubes with a seperate adapter. I´ve been listening the second day in row to a russian octal(6H9C) and am very pleased with it.It has some nice presentation of instruments, but bass is not that strong.
 You might have some luck and there is another spare adapter offered on this thread.But i have the impression they are also very fast sold, so check the thread regularly.


----------



## kvtaco17

tvrguy said:


> Hi Mordy,
> 
> I believe that is a Sagaris....Never made it into mass production. They only made a handful.
> Then TVR went bankrupt. No, I had a 1973 TVR 2500M that I restored.
> ...


 
  
 if you ask nice someone might make you one! I'd have to get my process down better BEFORE I was comfortable making a worthy adapter... though I'm not too far off... my only issue is building the rig into an acceptable enclosure.


----------



## mojorisin35

Nevermind stupid iPad...hit the wrong button and can't find a way to delete....


----------



## mojorisin35

tvrguy said:


> Hello All,
> 
> I have lurked on here for ages and joined last year.
> Have had many headphones in addition to some very high end gear since my teens.
> ...




I would suggest you get yourself the yugo 6HM5, I have tried most the non mod required tubes and it by far outpaces the others you have mentioned. And when you are ready to blow away everything move to an adapter and get into the 6dj8 realm which is another world altogether. Yrmv

Gary


----------



## kvtaco17

mojorisin35 said:


> I would suggest you get yourself the yugo 6HM5, I have tried most the non mod required tubes and it by far outpaces the others you have mentioned. And when you are ready to blow away everything move to an adapter and get into the 6dj8 realm which is another world altogether. Yrmv
> 
> Gary


 
 The Sylvania 6HM5 is another option... sounds very similar but a touch cleaner with slightly leaner bass.


----------



## TrollDragon

mojorisin35 said:


> I would suggest you get yourself the yugo 6HM5, I have tried most the non mod required tubes and it by far outpaces the others you have mentioned. And when you are ready to blow away everything move to an adapter and get into the 6dj8 realm which is another world altogether. Yrmv
> 
> Gary


 

 I've seen a few Yugo 6HM5's back in the day...


----------



## kvtaco17

^
 Such win
 Much YUGO
 wOw!


----------



## MIKELAP

trolldragon said:


> I've seen a few Yugo 6HM5's back in the day...


 
 Thats all there was a few and i might add FEW . Buy the way rockin to some Stevie Ray Vaugh with a Tung- Sol 6SL7 GT with Senns its  true bass is not  plentiful but its nothing an EQ cant fix !


----------



## mordy

My present car is nicknamed The Toaster, but this Yugo beat me to the punch!
  




 A Yugo piano:




 And a Yugo fireplace:




 Walt Disney stardom:




 And for u enthusiasts out there, a Yugo Bimmer:




 Man, a Yugo limousine:




 And a 4x4 Yugo:




 And a Yugo Monster Truck:




  
 Good night!


----------



## mordy

Hi All,
  
 Read somewhere that the best 6CG7/6FQ7 tubes had the Amperex label. However, it could be that they were made by GE and labeled Amperex. Could not find any Amperex tubes, but I bought a couple GE tubes. While testing a GE tube with thick copper roads I fell asleep and had this crazy dream of funny looking Yugo cars. Tube rolling does strange things to you...
  

  
 I designed a very sophisticated mounting for the voltage regulator on the side of the transformer on the back of the LD MKIII. The bread board was mounted with two screws to a scrap piece of wood and then secured to the transformer housing with two rubber bands. The wood serves as insulation and the rubber bands dampen the vibrations from the transformer. A ground wire was attached to the bottom left screw on the back of the amp and eliminated a high pitched buzz at unlistenable loud sound levels.. (Red wire bottom right on picture)

  
 The net effect is that the brightly lit display exudes a scientific aura to the auditory testing. I am now doing _instrumented_ testing. My multitester indicates a heater voltage of 6.30V (the display is a little humble). Plate voltage for the GE 6CQ7 is R 96V and L 95V. Grid voltage is R 2.74V and L 2.79V. Please note that the little brass voltage adjustment screw on top of the blue thingamajig is completely horizontal which facilitates the electron flow. These measured parameters measured well but are subject to interpretation.
  
 Initial listening tests of the GE tube vs the Raytheon are inconclusive but worse. Oops, I fell asleep again and dreamed of a Yugo fireplace. Crazy, isn't it? See u tomorrow!


----------



## rosgr63

gibosi said:


> rosgr63, welcome to Little Dot land.
> 
> By way of introduction, rosgr63 is the host of the "6SN7 Tube Addicts" forum, a real treasure-trove of information.
> 
> http://www.head-fi.org/t/479031/6sn7-tube-addicts


 
  
 Thanks for your kind words.
 I have been a LD owner and LD forum participant for a number of years.
 The work done here is unique and very exiting, I have posted here too some time ago.


gibosi said:


> To my knowledge, pre-made adapters to allow the use of double triodes in an LD do not exist. Unfortunately, at this time, it is a DIY project. It isn't all that difficult or expensive, but it does require that you invest the necessary time to understand what you are doing. The best I can do is to recommend that you read over the last 100 pages, or so. And after that, if you decide to jump in, we are here to help.
> 
> Cheers


 
  
 That's right.
 What I meant is that if somebody already uses the mod to run 6SN7's  and the LD has an octal base 6SN7 adapter, they can use more adapters to try 2C51/6CG7/ECC40/6F8G/ECC42/6C8G and so on. 
 If you can get your heater current to 1A, the options will include the Mullard ECC32/ECC34 tubes.
 These tubes are very expnsive but sometimes one can get lucky and get them cheap.
  
 If you can get your heater voltage up to 12V at 600mA you can use the 12SN7 tubes which sound like the 6SN7's but cost a lot less.


kvtaco17 said:


> *if you ask nice someone might make you one!* I'd have to get my process down better BEFORE I was comfortable making a worthy adapter... though I'm not too far off... my only issue is building the rig into an acceptable enclosure.


 
  
 Indeed


----------



## rosgr63

mordy said:


> Hi All,
> 
> Read somewhere that the best 6CG7/6FQ7 tubes had the Amperex label. However, it could be that they were made by GE and labeled Amperex. Could not find any Amperex tubes, but I bought a couple GE tubes. While testing a GE tube with thick copper roads I fell asleep and had this crazy dream of funny looking Yugo cars. Tube rolling does strange things to you...
> 
> ...


 
  
  
 Nice set up.
 If you can try RCA and Tung-Sol black plates 6CG7, FIVRE too.
  
 I usually dream tubes and amps, a Yugo would be a nice change...........


----------



## gibosi

A quick face-off: 6DJ8 VS 6SN7GT
  
 This evening I did a quick comparison of a 1960 Heerlen-made Amperex 7308/E188CC to a 1948 US-made Tung-Sol 6SN7GT/VT-231 with black glass and round black plates. I was surprised to discover that the tonality of these is actually quite similar. However, I did notice some significant differences. First, the bass on the TS is stronger, with more impact and better detail. Second, the stage on the TS is more 3-D, with more depth and apparent layering. The Amperex, which I previously thought had a very good 3-D stage, seems rather flat in comparison. And finally, the TS is dead quiet. In general, a 6DJ8 in my setup, with wires flying left and right, is much more susceptible to stray RF. I usually have to move the amp around on my desk to find a "quiet place". I have never had to do this with any 6SN7. They are all dead quiet, always.
  
 I am not a detail freak, so perhaps take this with a grain of salt, but I do not notice any difference between these tubes. Rather than tiny sounds, what I listen for is the ability to resolve individual instruments and vocals embedded in complex musical passages. In this, both of these tubes excel.
  
 However, in the end, better bass, more 3-D and dead quiet (in my system) gives the TS the edge. Now I am curious how it compares to a 1961 US-made Amperex 6922/E88CC......


----------



## rosgr63

The TS 6SN7 BGRP is considered to be one of the best 6SN7's by many.
 You might want to try the TS 6SU7GTY next.
 It's the 6SL7 equivalent with higher speck matched plates.


----------



## Nic Rhodes

and then comes the 6F8s and BL63 with a beefey PSU!


----------



## rosgr63

Nic, the 6F8G will be fine with the 6SN7 power supply.
  
 The BL63 will need 1.3A heater current.


----------



## Nic Rhodes

I know  interesting to see other peoples DIY travels amid tube rolling. Still loads of compatible tubes for not much money with great performance / value to go at. The 6N7 (sort of like 6A6) is fun as are the xx series tubes  (the 53 is like the 6N7 but different heater).


----------



## MIKELAP

Received some Refektor 6N23P tubes different presentation than octals but very nice nonetheless will listen to other similar tubes like 6DJ8 6BQ7A to see how they compare to each other .year of tubes are 1970 1971 and 1974 meanwhile a  picture.


----------



## TrollDragon

mikelap said:


> Received some Refektor 6N23P tubes different presentation than octals but very nice nonetheless will listen to other similar tubes like 6DJ8 6BQ7A to see how they compare to each other .year of tubes are 1970 1971 and 1974 meanwhile a  picture.


 
  
 Very Nice!
 I like the 6Н23П except mine is a Voskhod.


----------



## mordy

Hi,
  
 Here is an update on the GE 6CG7 tube. Trying to wake it up after some 50 years of hibernation. It has been on slow simmer for about 15 hours now.
  
 Compared to it's Japanese Raytheon cousin it is darker sounding and not as quick, but the bass is fuller and more hefty. The mid range is good with a lot of detail. Timbre excellent and no sibilance in the treble. Sound stage is impressive. Both the bass and treble are more recessed in the background compared to the Raytheon that is more forward and open sounding.
  
 Feel that it may need more time to wake up - will leave it on meanwhile. At this point it sounds very good, but not at the wow level.
  
*rosgr63*: Welcome to the Little Dot thread - we can all benefit from your expertise and knowledge! Looked up the 6F8G tubes on Ebay. Seems that they need a special adapter with an anode cap, and then this adapter fits into a 6SN7 octal socket. In your opinion, do the 6FG8(BL63) tubes offer better sound than the 6SN7 or 6CG7 tubes?
  
 Re the 6CG7 type tubes I have about half a dozen varieties, but all have gray plates. So far I have just listened to two, Raytheon and GE.
  
 The little voltage regulator I got can accommodate voltage sources from 4V to 40V and is rated 2-3 amps. I am using an old PS that puts out 20V and 2.5 amps so I think that this setup will accommodate almost all tubes that can be used with the Little Dot. The voltage coming out of it is always about 2V less than what goes in. (This PS won't work for 20V tubes, but it was free)
  
 Waiting for my first 8V tubes. Will report when they arrive and compare to the 6V version.
  
 Happy tube rolling!


----------



## rosgr63

Thanks.
  
 You'll need an adapter but the 6BL3 is taller and will need a longer cable than the 6F8G.
 I am not sure if the top contactor is the same diameter I've never used BL63 tubes.
  
 Some 6F8G sound better than their 6SN7 cousins.
  
 Try the 25SN7, even cheaper than the 12SN7 the Brimar 13D1 been one of the best.


----------



## gibosi

mordy said:


> The little voltage regulator I got can accommodate voltage sources from 4V to 40V and is rated 2-3 amps. I am using an old PS that puts out 20V and 2.5 amps so I think that this setup will accommodate almost all tubes that can be used with the Little Dot. The voltage coming out of it is always about 2V less than what goes in. (This PS won't work for 20V tubes, but it was free)


 
  
 Yes! Your 20V/2.5A adapter puts out 50 watts. Dividing 50 watts by 6.3 volts, it is capable of delivering almost 8 amps to a 6.3V tube! lol


----------



## TrollDragon

Now what I want to see is some ELROG 211's rolled here... 
	

	
	
		
		

		
		
	


	



 The tube looks gorgeous!


----------



## mordy

Hi G,
  
 Since my background is lacking in electronics, is this PS suitable for this application, or should I look for something else? Seems to me that only a small part of the capacity of it is used, which might not be bad at all.


----------



## mordy

HI TD,
  
 Here is a link to Elrog and the history behind the first German tube manufacturer in 60 years:
  
 http://www.6moons.com/industryfeatures/elrog/1.html
  
 How much do they cost? If you ask u can't afford them....
  
 Elrog makes displays for commercial airliner instruments and utilized their state of the technology in manufacturing these tubes.


----------



## gibosi

mordy said:


> Since my background is lacking in electronics, is this PS suitable for this application, or should I look for something else? Seems to me that only a small part of the capacity of it is used, which might not be bad at all.


 
  
 Yes, your PS is perfectly adequate, and in fact, having more power than you need is certainly not a bad thing. And except for tubes with a heater voltage of 20 volts or higher, you can easily handle any tube you desire.


----------



## rosgr63

The 13D1 and 25SN7's draw 150mA so you should be fine running them at 20V.


----------



## kvtaco17

trolldragon said:


> Now what I want to see is some ELROG 211's rolled here...
> 
> 
> 
> ...


 

 I'm down... I'll need 2 of them at.. OMG no that's expensive lol


----------



## gibosi

rosgr63 said:


> The 13D1 and 25SN7's draw 150mA so you should be fine running them at 20V.


 
  
 His 120VAC to DC adapter puts out a maximum of 20 volts. The voltage regulator reduces this to 18 volts. Is it really OK to run a 25SN7 at 18 volts? But of course if so, his PS has more than enough amperage.


----------



## rosgr63

You can run a 12SN7 at 6V and you never know its not a 6SN7.
 I assume (not sure) that 18V would be fine for a 25SN7.
 There will be no harm done to the tube, so I would just go ahead and try.


----------



## mordy

Hi,
  
 Here is the final impression of testing the GE 6CG7/6FQ7 tube after burning it in for close to 40 hours. Basically it accords with what I wrote before:
  
  
 Compared to it's Japanese Raytheon cousin it is darker sounding and not as quick, but the bass is fuller and more hefty, but could sound boomy. The mid range is good with a lot of detail. Timbre excellent and no sibilance in the treble. Sound stage is impressive. Both the bass and treble are more recessed in the background compared to the Raytheon that is more forward and open sounding.
  
 This tube is quite good and reminds me of an upgraded Ei 6HM5 "fireworks" tube in how it sounds. There are two peculiar u-shaped attachments on top of the top mica. (I have three other GE 6CG7 tubes that don't have those attachments - we'll see how they sound at a later time.)
  
 Conclusion: A nice tube (and far superior to ANY 6AK5 tube) but does not get top honors.
  
 Next: A RCA 6CG7/6CQ7 side getter tube from July 1972 (Code DX). Judging from the somewhat bent pins it probably is a used pullout. Used is sometimes better - does not require grueling burn-in.
  
 First impression: It sounds different and lower gain. Let's leave it at that for now until my listening brain is adjusted.
  


 The blotch on the left inside the tube is the side getter flash.


----------



## tvrguy

Thanks Gary,
  
 I ordered 4 Matched pairs of the Yugo 6HM5 and 2 Matched pairs of  Philips 6AK5 that I found.
  
I like to have spares and extras so I can trade.  
  
I have extra  N.O.S.Tesla 6F32's marked LG & STAB  witch I believe is 1952 Military.
  
Anyone have anything to trade?
  
They sound incredible!
  
Steve.


----------



## MIKELAP

tvrguy said:


> Thanks Gary,
> 
> I ordered 4 Matched pairs of the Yugo 6HM5 and 2 Matched pairs of  Philips 6AK5 that I found.
> 
> ...


 
 Here's free advice dont spend extra on matched pairs not worth it . I might add that as long as they are the same type and from same company its good enough for me .


----------



## tvrguy

Just an FYI....
 I never spend extra. So why not? sure can't hurt.
 My tube guy Dragan in Serbia does it for free when I order two or more.
 He has a very large supply of NOS tubes in 100 lots...all kinds of stuff.
 He tests all his tubes and grades them.So he will match as close as he can, but you do not get a fancy box.
 Now I understand some people like the old boxes too, but I am into sound and I rarely spend more than $6 per tube.
 So having tube parameters closely matched for no charge I feel is a good thing and I have never had any issues with stuff from him.
 If any one wants his email. PM me.
  
 Steve.


----------



## MIKELAP

tvrguy said:


> Just an FYI....
> I never spend extra. So why not? sure can't hurt.
> My tube guy Dragan in Serbia does it for free when I order two or more.
> He has a very large supply of NOS tubes in 100 lots...all kinds of stuff.
> ...


 
 Free is good : )


----------



## tvrguy

Mike (lap)
  
  
 Just read your profile...We could be twins our intrests are so alike.
 And you live in Montreal, I grew up in Laval and Ste. Agathe!
 Here is a question, I have one tube that flares up at the bottom ever time I power up my amp.
 I have no issues with the tube(sound) but it is the only one that does it.
 Whats up with that?
  
 Steve.


----------



## MIKELAP

tvrguy said:


> Mike (lap)
> 
> 
> Just read your profile...We could be twins our intrests are so alike.
> ...


 
 Are you still in Province! about tube flaring up i have a pair like that, i know its normal so nothing to worry about beyond that i dont remember why it does that exactly but if you use the SEARCH FUNCTION atop the page you will probably find the answer in this thread.


----------



## MIKELAP

You see on post 3544 a picture of the flareup of tubes it seem that was a feature for military tubes to get to temperature faster.


----------



## tvrguy

Very Cool.


----------



## i luvmusic 2

tvrguy said:


> Just an FYI....
> I never spend extra. So why not? sure can't hurt.
> My tube guy Dragan in Serbia does it for free when I order two or more.
> He has a very large supply of NOS tubes in 100 lots...all kinds of stuff.
> ...


 
 Dragan is the man highly recommended i did bussiness with him few times.


----------



## tvrguy

Yup,
  
 Dragan is a short wave radio technician and has a job with the National Weather Service.
 He keeps the Satellite Receivers and up-links etc. in working order.
 He dabbles selling tubes and stuff on eBay and is a Stand Up Guy..
  
 Steve.


----------



## gibosi

I may have purchased from this guy and not know it. Please send me a link to his ebay store. And thanks!


----------



## mordy

I would also like a link or email to this seller - thanks!


----------



## tvrguy

Pm'd You


----------



## tvrguy

Guess I better Post.
  
 His email is *astronomy@verat.net*
  
 His name is Dragan and his eBay id is:
  
*Top-rated seller*  *tachonz (2094 )*
  
Steve


----------



## gibosi

rosgr63 said:


> Try the 25SN7, even cheaper than the 12SN7 the Brimar 13D1 been one of the best.


 
  
 Do you know? Does the Brimar 13D1 sound significantly different than a Brimar 6SN7?


----------



## gibosi

Sylvania 6SN7GT "Bad Boy"
  

  
 Manufactured in the early 1950s, tall bottles, 3-hole T-plates, and bottom getter. Relabeled tubes do exist and can often be purchased for less.
  
 Much has been written about the sound of this tube, so I will not go into much detail. The bass is a bit more forceful and present than the Tung Sol BG/RP, the mids are somewhat warm and sweet, and the highs are crystal clear and airy. I like this tube a lot. However, compared to the TS, it comes up a bit short in the sense of 3-D space and imaging that make the TS so involving and addictive.
  
 Comparing the Sylvania to the Heerlen-made Amperex E188CC, the bass is stronger, the mids are not as lush, but still sweetly warm, and the highs are a bit more airy. Both tubes have excellent detail and transparency. The Sylvania's 3-D stage is slightly deeper, but not much, and in my system, it is quieter. In my mind, the Amperex and the Sylvania are very similar and neither is significantly better than the other. And I still prefer the Tung Sol over both, due to its superior 3-D stage and imaging.


----------



## chiman

Hey guys, looking to start tube rolling and wanted to check these were ok for a mkII and to get some opinions before I order anything. Thanks. 
  
 http://www.ebay.co.uk/itm/310282214423?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649
  
  
 http://www.ebay.co.uk/itm/6N6P-i-STONG-MATCHED-PAIR-tubes-NOVOSIBIRSK-Gold-grid-NOS-for-Little-Dot-MKIII-/141172381174?pt=Vintage_Electronics_R2&hash=item20de8795f6


----------



## rosgr63

gibosi said:


> Do you know? Does the Brimar 13D1 sound significantly different than a Brimar 6SN7?


 
  
  
 The 6SN7 equivalent is the 13D2, which sounds different from the 6SN7 Brimar.
 There is a variety of Brimar 6SN7 so I need to see a photo to be sure we're talking about the same tube.
  
 They came with black or brown base, clear or smoked glass, with or with out top coolers, O-ring getters, square getters and so on. 
  
 The GTY version is a nice tube too.


----------



## mordy

Hi chiman,
  
 Instead of the 6N6P-i, spend a little extra money on a pair of 6N6P-IR tubes. Then, instead of the Mullard tubes, order a pair of the 6HM5 Yugoslavian Ei tubes for $10 best offer.
  
 The total price should be the about the same or less, but the results will be better.
  
  


 








 6HM5 /6HA5 / EC900 export quality audio triode tube / NOS / FREE SHIPPING /  
 http://www.ebay.com/itm/6N6P-IR-ECC99-E182CC-PAIR-High-Durable-Double-Triode-Gold-Grid-NOS-OTK-/181267476422?pt=Vintage_Electronics_R2&hash=item2a34622fc6
  
 Good luck!


----------



## mordy

Hi rosgr63,
  
 Shopping around for 12SN7 tubes I came across two other tubes that are supposed to be higher grade than the 12SN7 tubes for use in aircraft servo systems.
  
 They are labeled 12SX7 and 2C52 and both are octal tubes. Would you know anything about them? Are they compatible with the 12SN7/6SN7 wiring, and is there any advantage using these tubes?


----------



## rosgr63

They appear to be compatible, but I have never tried the 12SX7.


----------



## gibosi

mordy said:


> Hi rosgr63,
> 
> Shopping around for 12SN7 tubes I came across two other tubes that are supposed to be higher grade than the 12SN7 tubes for use in aircraft servo systems.
> 
> They are labeled 12SX7 and 2C52 and both are octal tubes. Would you know anything about them? Are they compatible with the 12SN7/6SN7 wiring, and is there any advantage using these tubes?


 
  
 The 12SX7 is electrically identical to the 12SN7. The only difference is that it was designed to be less microphonic. So yes, it is simply a premium version of the 12SN7.
  
 The 2C52 is a high mu dual triode. While the 12SN7 has a mu of about 20, similar to a 12AU7, the 2C52 has a mu of about 100, similar to a 12AX7. This tube should work fine in our LDs as we have successfully used the high mu 12AX7 before and the pin-out is the same as the 12SN7.


----------



## Nic Rhodes

I have no experience of the 2c52 but the 12sx7gt is a great valve. It will consistently outperform all the 6 / 12sn7gt I use (basically all of them). It has lower distortion and is one of the cleanest sounding valves I know. Originally designed by GE I think, I have only ever found KenRad and RCA examples. It was used in 26v string radios and not audio. It's use was largely over by 1955. My last examples are from 1955. RCA are by far the most common, though I have never got the bottom of the Canadian examples. Interestingly these Tubes were heavily burned in before release so often have spotty getter which many people think are heavily used examples when in reality are NOS! This does allow more negotiation on price if the seller doesn't know what they have  you do need to give them a nice DC heater voltage however and this puts many off using this tube. Certainly a tube to try further if you have a separate PSU.


----------



## mab1376

mordy said:


> Hi chiman,
> 
> Instead of the 6N6P-i, spend a little extra money on a pair of 6N6P-IR tubes. Then, instead of the Mullard tubes, order a pair of the 6HM5 Yugoslavian Ei tubes for $10 best offer.
> 
> ...


 
  
 how would you compare these to the 6av6 variants?


----------



## mordy

Hi mab1376,
  
 From reading chiman's post I got the impression that he was just starting to do tube rolling, and that the tubes he picked required no modifications at all. I can well understand the hesitation and worry about using straps and adapters, so that's why I suggested something simple that is plug and play.
 The 6AV6 tube is very good, but it requires switching to EF92 setting and  cutting off and taping pins 5&6, and not everybody is comfortable in doing this.
  
 As you well know, there are many driver tubes that are significantly better, but these tubes require modifications or adapters and voltage regulators.
  
 I could see a market for an adapter package with a built in voltage regulator and different switches for using 6DJ8 wiring and 12AX7 wiring, as well as octal and loctal adapters (and a C3g adapter!).


----------



## mab1376

mordy said:


> Hi mab1376,
> 
> From reading chiman's post I got the impression that he was just starting to do tube rolling, and that the tubes he picked required no modifications at all. I can well understand the hesitation and worry about using straps and adapters, so that's why I suggested something simple that is plug and play.
> The 6AV6 tube is very good, but it requires switching to EF92 setting and  cutting off and taping pins 5&6, and not everybody is comfortable in doing this.
> ...


 
  
 I would gladly pay for a c3g adapter if someone wanted to start selling them based on Hypnos1's feedback on those tubes 
	

	
	
		
		

		
		
	


	



  
 I've also really wanted to try 6SL7 tubes for quite a while but just don't have the time to start building adapters. I'm just bad with making my own adapters due to lack of time and lack soldering/assembly skill.
  
 I've been using 6AV6 tubes for about 6 months and just a little antsy to try some tubes i haven't personally tried.
  
 As we know rolling is an addiction! 
  
 Thanks for the feedback!


----------



## mordy

Why don't you look over my post about building a solderless adapter? It really isn't that hard, and the benefits are immense.


----------



## chiman

Yep I'll be starting tube rolling soon, so plug and play is what I was after.

Thanks mordy for the suggestion. Ordered them last night so will hopefully get them next week.


----------



## tvrguy

Hi Gary,
  
 Have you heard the Tesla's Yet?
 I have been using Mullard 8100's and Voshkod 6ZH1P-EV and I find the 1953 Tesla's I now have burned in have a smoother top end. A more subterranean bottom with faster transients, better (but not wider! Maybe more height information) and a more liquid sound. I am using 6H30-PI as power tubes.
 My background is Many years of high end Audio, but not so much headphones. Just getting into it heavy now I am in a Condo.
 Hope this helps. 
  
 Steve.


----------



## mojorisin35

tvrguy said:


> Hi Gary,
> 
> Have you heard the Tesla's Yet?
> I have been using Mullard 8100's and Voshkod 6ZH1P-EV and I find the 1953 Tesla's I now have burned in have a smoother top end. A more subterranean bottom with faster transients, better (but not wider! Maybe more height information) and a more liquid sound. I am using 6H30-PI as power tubes.
> ...


 
  

 Steve,
 If it is me you are asking then yes I have heard the Tesla’s see pg 60 of this thread. There appear to be a couple of versions of the Tesla 6f32’s tubes the ones I have are factory matched with stab written on the side, tesla 6F32 is in grey paint, and they also have white paint on the top of the tube making it look like the tube is wearing a elf hat. There are other tesla 6f32 tubes with yellow writing and no paint that I understand sound quite different (not that great) which ones did you have? My memory of them is that I felt that they where a better smoother version of the Voshkod 6ZH1P-EV and they were A++ tubes, which is saying allot as the Voshkod once they are burned in are held in very high regard.
 What type of headphones are you using?
 Gary


----------



## MIKELAP

These are my TESLA 6F32V  ,and if you want to see what year yours are  heres a link  .                                                                                                                                                                                                          http://tubes-store.com/article_info.php?articles_id=5&osCsid=jtsu6codduvs3fua4v1ddilj10


----------



## mab1376

mordy said:


> Why don't you look over my post about building a solderless adapter? It really isn't that hard, and the benefits are immense.


 
 will do! I have a lot of reading to do, its been a few months 
	

	
	
		
		

		
			





 
  
 page number?


----------



## gibosi

mab1376 said:


> will do! I have a lot of reading to do, its been a few months
> 
> 
> 
> ...


 
  
 As Mordy mentioned, you can do this without any soldering whatsoever. All you need is a 9-pin breadboard socket:
  
 http://www.ebay.com/itm/9-pin-breadboard-prototype-tube-socket-for-DIY-experimenting-/151176364267?pt=Vintage_Electronics_R2&hash=item2332d040eb
  
 Two 7-pin Vector test sockets:
  
 http://www.radiodaze.com/product/15450.aspx
  
 And if you wish to roll tubes which require more than 500ma of heater current and/or 12 volt tubes, a 24 volt AC adapter and a step down voltage regulator:
  
 http://www.ebay.com/itm/High-Quality-5-5mm-2-5mm-24V-1A-AC-DC-Adapter-Black-With-Latest-Technology-/350983324845?pt=US_Server_Power_Supplies&hash=item51b83c84ad
  
 (You might already have a suitable AC adapter. I am using one from an old cordless drill/driver)
  
  http://www.ebay.com/itm/LM2596-Digit-Display-4-40V-DC-DC-Converter-Module-Step-Down-Regulator-Voltmeter-/360685295663?pt=LH_DefaultDomain_0&hash=item53fa84d82f
  
 Crude and ugly, but it works. Moreover, since no soldering is required, you can easily reconfigure it if necessary.


----------



## gibosi

Recently received a Raytheon VT-231/6SN7GT manufactured in the 1940s. It has black ladder plates and two free-standing support posts. From what I have read, this version is superior to the earlier version with T-plates and no support posts. I haven't had a chance to really listen to this tube and am curious to how it compares with the US-made Ratheon 6CG6, that a number of us have, which apparently has the same ladder plates squeezed into a 9-pin miniature bottle.


----------



## tvrguy

Hi Gary,
  
 Yes, I have the "Yellow" Tesla tubes and was not impressed.
 However I got a pair of the white Lettered/Tipped ones and those are the ones that blow away all others I have listened to!
 I have taken photos of both side by side to show the guys but I can not post them?
 Nor can I update my profile? Really???
 I have been an avid Audiophile since the eighties and I am not allowed to share  on here.
 I also took some photos of the original boxes if anyone is interested. I bought8 more of the white tipped ones for the future and to trade.
 I have ordered the Yugo 6HM5's you told me about and some Phillips 6AK5 "Low Noise" microphone tubes. Will have them hopefully before the end of January.
 I had Russian 6H6N power tubes and right now I am using Sovtek 6H30-EB, I found them to be better overall. Would love to get some feedback/advice.
  
 A little bit about myself, I have been selling Mercedes-Benz, Porsche etc. for over 25 years.
 Hobbies...Sailing, Photography, Cars, (raced a Caterham 7 in the 80's)
 I enjoy ANY Music that is recorded/mixed well.
 My tendencies are to Progressive Rock, Genesis, Pink Floyd, Marillion, Supertamp etc.
 My house/Basement is now gone and I am into a Condo. New Lady, New Life.
 Just to let you know where my head is sound wise. Here is what I have trained my ears on.
 I have had a Mark Levinson Amp and Preamp, A fully optioned Linn LP-12/Lingo and loads of Very Good Cables/Interconnects,Speakers etc. for the last 20 years. 
 I've been using modified Proac Response 2's and Sand/Lead filled Target stands with 2 Vandersteen Subs. So you know I love Imaging, Depth and Quick Transients.
 My ears have been Very Spoiled...Having friends/Clients that work in the industry has it's rewards.
 I am now down to one sub and the Proacs. Have had two noise warnings from the Condo Board Gestapo, So Head-fi it is.  
 I have had many Headphones since the Seventies and never really spent much time with them until I got the warnings and then a Little Dot III (ver. IV).
 I have settled on an older pair of HD-650's. Heard newer ones and they sounded different...have no idea why?
 I put a Zu Audio, Mobius II cable on the phones and a custom made 3 foot power cable on the amp and I would put this present combo I have assembled up against anything.
 Subjectively it is Amazing!! Differences in tubes are readily discernible.
 It is real nice to have met a bunch of guys to talk to who have a collective knowledge that I can tap into.
 We can all save each other time and money by collaborating.
 I hope I can contribute to the group. And have some fun along the way. If anyone would like to PM me with a blurb about themselves...Mail away.
 I have already spoken to "Mikelap" on the phone..this site is going to be Fun!
 Maybe one day the moderator will take off the handcuffs and let me do some meaningful stuff on here.
  
 Steve..


----------



## gibosi

tvrguy said:


> Maybe one day the moderator will take off the handcuffs and let me do some meaningful stuff on here.


 
  
 I believe the "handcuffs" automatically come off after you have posted X number of times. But I do not know exactly what the value of X is....  
  
 Cheers


----------



## gibosi

tvrguy said:


> Yes, I have the "Yellow" Tesla tubes and was not impressed.
> However I got a pair of the white Lettered/Tipped ones and those are the ones that blow away all others I have listened to!


 
  
 Perhaps your Teslas look like these?


----------



## chiman

I saw these on eBay last night.

http://pages.ebay.com/link/?nav=item.view&id=221354389799

These look different to the above examples.


----------



## tvrguy

They are similar...the ones I have are from 1956 (date code LG)


----------



## gibosi

tvrguy said:


> They are similar...the ones I have are from 1956 (date code LG)


 
  
 And mine: TG = Oct 1957. So very close.
  
 Chiman:  If you look at the plates, the mica and the getter splash, the tubes you are looking at on eBay are the same vintage, and odds are they will sound the same.  It is often best to ignore the silk screening and paint, as it was applied after the tube was built, and often as not, customized for the end user.


----------



## MIKELAP

tvrguy said:


> Hi Gary,
> 
> Yes, I have the "Yellow" Tesla tubes and was not impressed.
> However I got a pair of the white Lettered/Tipped ones and those are the ones that blow away all others I have listened to!
> ...


 
 Condo Board Gestapo funny man lol i know what you mean went thru that as well.sometimes i feel like going crazy but i to have to take it easy thats what i miss the most about having a basement and cranking it out oh well. Usually i have my 6N6PIR power tubes on the amp with Tung Sol octal black glass so i decide to install the Electro Harmonix 6H30PI to see how they are with octals since usually they are not as warm sounding as the IR finally  i like it cleans thing up just enought in my opinion will leave them on for a bit.


----------



## gibosi

chiman said:


> I saw these on eBay last night.
> 
> http://pages.ebay.com/link/?nav=item.view&id=221354389799
> 
> These look different to the above examples.


 
  
 Tesla date codes:
  
 http://web.archive.org/web/20070824161210/http://www.radiojournal.cz/tab4.htm
  
 If I am seeing this correctly.... these tubes: CL = November, 1955


----------



## tvrguy

Hi Chiman, Hi Gibosi,
  
 These are the photos I took.  The Yellow Printed ones came with the original boxes and sound OK but not stellar. Thnk Radio Shack Stuff.
 The Ones labeled in White sound Incredible! Better than my Mullard 8100's or my Voshkod 6ZH1P-EV's
 Need more feedback from the crew on here . Which tubes do you like that DO NOT require any mods to the amp.
 If I have to mod this amp to get better sound I will just move upmarket but I really 
  

  

  
 I am at the point of diminishing terms already.
 This Little Dot Rocks!!!  You all know that already.


----------



## mcandmar

So i bought this old LittleDot II+ amplifier second hand on flebay for pocket money which unfortunatly arrived in a sad state with one channel completely dead, headphone socket all wobbly, and power tubes flashing and arcing during warm up. Considering all i paid for it i wasn't that bothered, but figured it was worth trying to fix up for some fun.
  
 On tear down i came to the conclusion it had taken a fall at some stage, volume pot was all banged up with a split PCB which explained the dead left channel, and the headphone socket was showing signs of physical abuse too causing the wobbly and cracking connection. Back on flebay i ordered up a new pot and headphone socket for $10, and a pair of Russian 4P1L tubes for $5 to replace the 4P1S items that were arcing and quite frankly freaking me out 
	

	
	
		
		

		
		
	


	



  
 After a bit of iron waving surgery i got all the new bits installed and have been listening to it all night long with a pair of Grado 225is plugged in.  Honestly i was expecting this to be either a bit meh, or an utter piece of crap but instead i am genuinely shocked at how good this thing sounds. Ok its a bit overly tubey and warm but its not lacking in detail or high end response at all, i am really surprised with this little thing and finding it very hard to fault. 10/10 for fun factor.
  
 I do have one question though, is it normal for the case to get so hot you cant hold your hand on it?


----------



## mordy

Hi tvrguy,
  
 Glad to see a Koss Porta-Pro listed next to the Senns. These were recommended by Sam Tellig, and I finally got a pair on sale. Except for a little heavy on the bass I found them very enjoyable.


----------



## TrollDragon

Wow that is a vintage II+, I guess it is common for the 4P1S's to arc as they are quite poorly made. Here is a thread on the amp and the 4P1L's

 www.head-fi.org/t/265470/little-dot-2-owners-4p1l-tubes


----------



## TrollDragon

mordy said:


> Hi tvrguy,
> 
> Glad to see a Koss Porta-Pro listed next to the Senns. These were recommended by Sam Tellig, and I finally got a pair on sale. Except for a little heavy on the bass I found them very enjoyable.


Hey mordy

The Porta Pro's are a great little open headphone I just love them. If you want a great portable closed headphone the JVC HA-S500's only from Japan on eBay are quite a step up from the Koss. They are my first goto portable when I don't need the openness of the Koss.

I bought from this seller here:
 http://www.ebay.com/itm/141169666280

There is also a 700+ page appreciation thread here on HF.


----------



## MIKELAP

Does anybody have those National Union 6SL7 tubes how would they compare to the Tung Sol 6SU7GT and Sylvania 6SL7 VT-229


----------



## gibosi

Those are some great looking tubes! Unfortunately, the only 6SL7s I have are a Tung Sol 6SU7GTY and a Sylvania 6SL7WGT. However, I do have a NU 6SN7GT. It is very smooth and liquid but rather dark with a very strong bass. I'll be curious to learn what you think of your tubes.


----------



## TrollDragon

The coffee is hot, the 6Н23П is all warmed up and the German Maestro's 8.300 D's ready to go...

  
 A little Chet queued up in 24/192

 Smooth very smooth.
  
 Taking a Jazz Appreciation course from the University of Texas at Austin.
 Sign up closes today (Sunday) if anyone is interested in it.


----------



## Nic Rhodes

I have dug out 'Uncle Erics' medium Mu triode tests from the mid 90s as of relevance to the DIY experrimenters here.
  
 Top tube was a
  
 76 Sylvania 40s, 2nd harmonic at 0.002%, Rp 37k
  
 then
  
 5687 RCA 50s, 2nd harmonic at 0.005%, Rp 48k
 6CG7 / 6FQ7 Sylvania 60s, 2nd harmonic at 0.005%, Rp 25k
 9002 Kenrad 40s, 2nd harmonic at 0.005%, Rp 48k
 76 RCA 40s, 2nd harmonic at 0.005%, Rp 37k
 12SX7 JAN RCA 1955, 2nd harmonic at 0.005%, Rp 37k
 12SX7 JAN RCA 1955, 2nd harmonic at 0.005%, Rp 37k (another example but tested identially)
  
 than follows 5687WB, 396A/2C51, 6C5G, 76, 6GH8A, 5814 and the first 6SN7GT
  
 6SN7GTA Sylvania 1982 and 1978, 2nd harmonic at 0.015%, Rp 48k
  
 and then pages more of tested valves but this is where most 6SN7GT start appearing (so quite high up the list)
  
 Erics general conclusion were:
  
 basically 5687 and 6CG7 are capable of low distortion but need to be selected first.
 Old 6SN7GT are very consistent (span being only 0.2%). Current Russian are OK but not as good as NOS.
 9002 (and Acorn 955) are good.
 Antique triodes like 27, 56, 76 are excellent. [perhaps also 30, 37?]
 12AU7 and 5814s are not consistent.
 7199 is not standout despite being a hifi tube!
 Steer clear of 5963 and 5964 as they were intended a computing switching tubes and not linear operation.
 12SX7GT were used in old military radion, if you are offered some don't turn them down. [These are ones that always stood out to me on the list and why I have used them ever since]
 396A,, 2C51 are under appreciated in audio circles like 9002 and 7F8 (loctal version of 396A, 2C51).
  
 Eric was recommending tubes above 0.025% distortion which covered most 6SN7GTs.


----------



## gibosi

nic rhodes said:


> I have dug out 'Uncle Erics' medium Mu triode tests from the mid 90s as of relevance to the DIY experrimenters here.


 
  
 This is very interesting stuff. Thanks for posting!
  
 But I wonder... Did Eric test the 6DJ8/6922/7308 tubes?
  
 And also... I have been listening to the 6085/E80CC, and think this might be the best dual triode I have ever heard in my LD. Did Eric test this tube?


----------



## Nic Rhodes

gibosi said:


> This is very interesting stuff. Thanks for posting!
> 
> But I wonder... Did Eric test the 6DJ8/6922/7308 tubes?
> 
> And also... I have been listening to the 6085/E80CC, and think this might be the best dual triode I have ever heard in my LD. Did Eric test this tube?


 

  re 6DJ8/6922/7308 yes he did test in his 'book', also most of this came out in VTV issues also. [I previous offered here to post the VTV 6DJ8/6922/7308 article but no one showed any interest then]. I will check on his stuff for E80CC but from my perspective it is a quality tube. No surprizes on that tube! Not cheap anymore but I did get a pair of Tungsrams for very decent money a month or two ago.


----------



## mordy

Hi Nic Rhodes and Gibosi,
  
_"6CG7 / 6FQ7 Sylvania 60s, 2nd harmonic at 0.005%, Rp 25k_" This tube is #3 on Uncle Eric's list.
  
 I am listening to this very tube now, and it is quite good. Would put it on the level of the Japanese Raytheon. In comparison it has more bass presence but the treble is better in the Raytheon. Not as a forward sounding as the Raytheon.
  

  

 The left tube is a 60's Sylvania and the right tube is the Sears branded version (appears identical).
  
 Now, for somebody electronically challenged like me, can you please explain what difference the harmonic distortion makes, especially very small differences? Also, what is Rp37, Rp48 etc? Are there values you could use to match your equipment?
 Can something that does not measure great sound good?


----------



## gibosi

Do you know if there is an index for VTV? I downloaded issues 1 through 20, but without an index, it is not at all convenient or easy to find anything relative to a particular tube....


----------



## Nic Rhodes

I am afraid it is a trawl through the back issues...nice article on 12SX7GT as a tube dumpster..


----------



## mordy

Here is my first 8.4V tube - a Sylvania 8CG7/8FQ7 from February 1952. The other date code is JAM. I have yet to find any post that deciphers the three letter date codes, and I can't figure out any connection between JAM and 652. (At least JAM is better than XYZ which is printed on one of my Sylvania tubes!)
  
 In addition, the logo is not the usual Sylvania S or oak leaf, so I have my doubts if it really was made by Sylvania. However, the internal construction looks to be the same as the Sylvania 6CG7/6FQ7 tubes that I have.
  

  

  
 If anybody could answer my questions at the end of post 4795 (above) I would appreciate it - thanks.


----------



## gibosi

mordy said:


> In addition, the logo is not the usual Sylvania S or oak leaf, so I have my doubts if it really was made by Sylvania. However, the internal construction looks to be the same as the Sylvania 6CG7/6FQ7 tubes that I have.
> 
> 
> If anybody could answer my questions at the end of post 4795 (above) I would appreciate it - thanks.


 
  
 The internal construction looks identical to my Sylvania 6CG7. Moreover, looking at the plates, it looks nothing like an RCA, Tung-Sol or Raytheon, so I believe it really is a Sylvania.
  
 As to your questions....
  
 In my uninformed opinion, I am not sure we can hear distortion in the range of 0.005% to 0.015%, but I certainly do not know....
  
 I do not know what Rp 37k or Rp 45k means.... perhaps 37k and 45k are frequencies? But what is Rp?
  
 And if a tube measures bad and sounds good, it begs a number of questions: What parameters were measured? Can it be demonstrated that these parameters have any relationship to what we hear? If so, perhaps our ears are more sensitive than the test equipment? Anyway, I do not put much stock in measurements. I trust my ears and those of my colleagues.


----------



## mab1376

Has anyone used 6SN7 with the octal adapters? I think i read somewhere it needs more power than the LD can provide but i'm not sure. Currently i've got a re-issuse Tung SOL 6SL7GT and a NOS Tung Sol 6SU7GTY in the mail to get started rolling octals. Can't wait to get started!


----------



## TrollDragon

Rp is the Dynamic Plate Resistance of the tube.

Here is a good explanation of that value:
http://www.guitarstudio.tv/Splawn/explanation_you_must_read.htm


----------



## gibosi

mab1376 said:


> Has anyone used 6SN7 with the octal adapters? I think i read somewhere it needs more power than the LD can provide but i'm not sure. Currently i've got a re-issuse Tung SOL 6SL7GT and a NOS Tung Sol 6SU7GTY in the mail to get started rolling octals. Can't wait to get started!


 
  
 Yes, you can use the 6SN7 with an octal adapter. It is pin-compatible with the 6SL7, so plug and play. *But* it does draw 600ma and this is more than the 500ma that many of us believe the LD can safely provide. So if you want to roll 6SN7, it is strongly recommended that you get an AC to DC adapter and a voltage regulator.


----------



## gibosi

6SN7 to E80CC and everything in between...
  
 Yesterday, I revealed my tricked-out LD1+ (running a MUSES 02) to several local Head-fiers. And I asked them to help me evaluated four tubes:
  
 1948 Tung-Sol 6SN7GT with black glass and round plates
 1960 Heerlen-made E188CC
 1951 Western Electric 392A/2C51
 1961 Heerlen-made E80CC
  
 Our goal was to determine the tube with the most accurate and correct tonality. We listened through a pair of HD 700 headphones, and for music, we used "Halloween" and "The Stone" from "Before These Crowded Streets" by the Dave Matthews Band. These two tracks seamlessly run together for a run-time of about 12 and 1/2 minutes.
  
 As could easily be predicted, the 6SN7GT was judged to be the most colored, and thus ranked No. 3. The E188CC and the 396A/2C51 tied for No. 2. And the E80CC was judged No. 1, based primarily on it's ability to accurately reproduce treble and upper harmonics.
  
 In my mind, the Heerlen E80CC is a step up from the Heelen E188CC, and those of you who place a premium on linearity and accuracy, may wish to try this tube. However, they can be a bit expensive (but I got mine for only $29.00, likely because it carries the Zaerix label, and not Amperex). Moreover, you will need an external heater PS as this tube draws 600ma at 6.3 volts or 300ma at 12.6 volts.
  
 To my way of thinking, I am very happy to have both the Heerlen E80CC and the Tung-Sol 6SN7. When I wish to listen actively, the Heerlen E80CC is my choice. Its accuracy and clarity is quite amazing. But when I want to chill out, perhaps after a drink or two, the Tung Sol is my choice. The added warmth and coloration, while certainly not accurate, is quite beautiful. And the tube transports me to an enhanced, or should I say "exaggerated", sound stage which feels magical.


----------



## mordy

Hi Gibosi,
  
 I believe that you have the Raytheon 6CG7/6FQ7 tube. How does it compare to the tubes you did a shootout on?


----------



## mordy

Hi trolldragon,
  
 Thanks for the link about Dynamic Plate Resistance (Rp). I cannot say that that I understand it too well, except that this value seems to be a real world measurement of the tube in action.
 What I don't understand is if the Rp value can be taken as a sole indicator of how well the tube sounds, or if this value must be used in the context of other measurements.


----------



## kvtaco17

mordy said:


> Hi Gibosi,
> 
> I believe that you have the Raytheon 6CG7/6FQ7 tube. How does it compare to the tubes you did a shootout on?


 
 This!


----------



## gibosi

mordy said:


> I believe that you have the Raytheon 6CG7/6FQ7 tube. How does it compare to the tubes you did a shootout on?


 
  
 It's on my to-do list, along with comparing it to the Raytheon 6SN7GT/VT-231. 
  


Spoiler: Raytheon 6SN7GT


----------



## mordy

Hi Mikelap,
  
 I believe that I have the same type of National Union tube as you have:

 If you look at post #4132 on page 276 you will be able to read my impressions of it. After 100 hours of burn in I wrote that " I have this single 1940-50s  octal National Union 6SL7 which is getting better and better. After about 100 (!) hours of burn in the bass is getting more and more distinct and powerful and the detail, imaging and sound stage all have improved. An absolutely delicious tube!"
  
 Right now I am visiting 6/8CG7 land. The 8CG7 Sylvania tube I am listening to now has more powerful bass than the Sylvania 6CG7. What I like about this family of tubes is the beautiful timbre and quickness and wide sound stage.
  
 I would really like to hear from AFB how this tube compares to his best 6DJ8 type tubes.....


----------



## mordy

HI G,
  
 Your Raytheon tube looks similar to mine.

  


 I listened to this tube but unfortunately, I was not impressed. The bass and treble had limited extension, and it just sounded tired. Hope your example is better.


----------



## gibosi

mordy said:


> HI G,
> 
> Your Raytheon tube looks similar to mine.
> 
> I listened to this tube but unfortunately, I was not impressed. The bass and treble had limited extension, and it just sounded tired. Hope your example is better.


 
  
 Yours is an earlier version, with T-plates. Mine is a bit later, with flat ribbed plates and two support rods. According to "The Reference 6SN7 Thread", the flat plate version sounds better.... And after reading your comment, I sure hope so.   
  
 As my US-made Raytheon 6CG7 also has the same flat ribbed plates, it is reasonable to think that my 6SN7 will sound very similar, but will have to wait and see....


----------



## TrollDragon

mordy said:


> Hi trolldragon,
> 
> What I don't understand is if the Rp value can be taken as a sole indicator of how well the tube sounds, or if this value must be used in the context of other measurements.


Everything factors into the equation, board component values, output tubes, the whole works... I wouldn't worry too much about all the factors. If your music sounds good to you with a certain tube then that is really all that matters isn't it?

Personally I'd rather listen to my music then concentrate on listening to the gear. 

There is only so far you can take these little amps, once you've listened to higher end tube gear with an optimal circuit designs and much better components, a few tubes rolled will not give you the sonic quality of the higher end rigs. It's a lot of fun to check out all the possibilities but at some point the pursuit of the "Perfect Tube" becomes more than the results obtained IMHO.

Take Artsi's DIY octal amps for example, I don't even think he has listened to his Little Dot since he made the jump. He can fine tune all the other components for optimal results as well as adjust the tubes he is using for proper performance.

This is why I don't actively persue the FoTM tube anymore, I don't really need a drawer full of tubes that I will never listen to a month or two later. 

This is just my take on the whole thing, YMMV and it's all good for those who want to seek out some great tubes.

Sorry for the rant...


----------



## Artsi

Yes,it is more than 2 weeks when i have listened my little dot for one minute.

Surprisingly i have focused now rolling my 6080 and 6AS7 power tubes. They affect much to sound quality in my diy amp. Much more than with little dot. Of course 6080/6AS7 tubes quality is rather variable and they are not meant for audio originally. And they need serious burn-in for an optimal sound. Now i'm listening raytheon 6080WC's. As new sound is very smooth and enjoyable, but i hope after hours of usage sound get more sharpness.

I still have much to learn with diy tube amps. It is fun to notice how different resistor values and different biasing will affect to sound.

Next i'm planning to do little amp with 4 6N6P's as powertubes and one octal socket for double triode to drive them. Amp should be appropriate to use even with 32ohm headphones,since output impedance should be around 25-30ohm. I have octal to 9pin 6 and 12v adapters, so with this amp i can roll all my single double triodes. 

sorry for offtopic


----------



## mordy

Hi TrollDragon,
  
 Thanks for your insightful comments. Had to look up what FoTM means (flavor of the mouth). I too, do have boxes of tubes that I will never listen to. However, to me, part of the excitement in tube rolling is to find an obscure and cheap tube that beats the big expensive boys.
  
 As has been mentioned by some of the members on this forum, there seems to be a feeling of seeing the tube glow at the end of the tunnel, although different people have different preferences. Personally, I think that the human ear is the most sensitive instrument. What is amazing to me is that people in different parts of the globe and with very diverging tastes in  music can come to a conclusion and agree on which tubes are the best for the Little Dot amps.
  
 Some people like the super detailed, analytical tubes, others the warm and musical ones. I think that it is possible to find a tube that is both super detailed and warm, and with excellent bass and treble characteristics. In other words, a tube that has EVERYTHING.
  
 Maybe ignorance is bliss, but not having heard the super expensive tube amps, I am perfectly happy with the sound I now get out from my LDIII. Nothing bothers me, and I have been listening to music and Hi Fi for over 55 years.
  
 The LD MKIII is hooked up to a 80's Sony 110W amp, and I am using plebeian Polk speakers with a sub. Musical bliss for a very small cost, + the cost of some 400 tubes....LOL


----------



## TrollDragon

Hey mordy!
  
 That is excellent then, please do enjoy the fun and your great setup.


----------



## i luvmusic 2

With all of those 8 pins and 9 pins tubes that you guys are using with adapters/converters with separate power supply does it really sound better than most of the 7 pins tubes specially compare to 6HM5 and  6CS6(my favourite)?


----------



## mordy

Hi i luvmusic2,
  
 I have both the tubes you mention, and I can assure you that the 6DJ8/6SN7/6CG7 etc tubes sound significantly better. I don't think that a single person on this this forum who has tried the new types that require adapters (and regulators) disagrees and is willing to go back to those tubes.
  
 If somebody has explored and tried both types, and prefers the previous types that do not require adapters, speak up!


----------



## mojorisin35

i luvmusic 2 said:


> With all of those 8 pins and 9 pins tubes that you guys are using with adapters/converters with separate power supply does it really sound better than most of the 7 pins tubes specially compare to 6HM5 and  6CS6(my favourite)?


 

 After reading your post I took up the challenge to compare the two. I was initially sold on the the yugo 6HM5 being the penultimate non modded tube and if it were not for the kind head fi member mike lap selling me an adapter I would have been content with the yugo’s. I loved the spaciousness of the yugo’s the detail blended with the ultra wide soundstage. I received my adapter and soon after a 68 Amperex OG 6DJ8 and I have not looked back. 
 Having just rolled the yugos back in after a month of the 6DJ8 I can tell you it is a significant improvement that could be discerned by anybody. 
 I am a big fan of soundstage and this is the closest I have come to understanding and experiencing the term “holographic” soundstage. The yugos have a wider soundstage than the 6dj8 but the 6dj8 are well... holographic. With the 6DJ8 I hear the notes reverberate inside the acoustic guitar, I can discern the depth of the players on stage, and finally I can tell the height of the drum kit some which are placed above the players on stage and some on the same plane as the players but sitting vs the players standing. At first I thought it was the placebo effect but when I go online and look at live recordings I can see that the stage setup of the players is as it is reproduced on my recordings and I am convinced. 
 I know that the whole adapter world can be intimidating however switching has been the single best thing I have done to increase my listening experience. 
 The cost is significant more compared to the yugo’s so that is a factor you have to consider, my Amperex is a middle of the road tube in this family with the big hitters running in the hundreds of dollars.
 Hope this helps
 Gary


----------



## gibosi

i luvmusic 2 said:


> With all of those 8 pins and 9 pins tubes that you guys are using with adapters/converters with separate power supply does it really sound better than most of the 7 pins tubes specially compare to 6HM5 and  6CS6(my favourite)?


 
  
 In my opinion, yes.


----------



## i luvmusic 2

mordy said:


> Hi i luvmusic2,
> 
> I have both the tubes you mention, and I can assure you that the 6DJ8/6SN7/6CG7 etc tubes sound significantly better. I don't think that a single person on this this forum who has tried the new types that require adapters (and regulators) disagrees and is willing to go back to those tubes.
> 
> If somebody has explored and tried both types, and prefers the previous types that do not require adapters, speak up!


 
 The reason i asked, originally i was suppoesd to build an adapter for both types of tubes(8 and 9 pin tubes)i ordered parts online then i waited  for nearly a month only to find out that my order was lost.For the meantime while i was waiting for my parts to arrived i bought few pairs of 7 pins including the 6HM5 and during that time i did tried all the tubes that i have on hand and the only two types of tubes that i really like(sound good to me)is the 6HM5 Yugoslavia and 6CS6 Tung-Sol.I got used to the sound  of the 6HM5 and i really like it never used the other tubes since.So before i order parts again(locally this time)i need an opinion regarding the sound of 8 pin tubes.The only concern i have now is the annoying HUM few weeks ago i did build an adapter for 12AU7 and man i tell you the Hum was really really bad.Thanks for your input again THANK YOU!


----------



## mordy

Regarding the hum, if you used an external voltage source, connecting one of the low output voltage wires to ground on the chassis of the LD amp may help.
  
 I also found that using better insulated wires from the adapter to the socket helped, as well as moving around the wires and the socket adapter until the hum disappears or gets lower.
  
 Another thing to watch out for is a portable phone or similar device in close proximity to the amp. It may cause noise and interference, and moving it away may help.
  
 Good luck!
  
 PS: If you really are happy with what you have, you could just stop there and enjoy listening to the music. However, if good is good, isn't better better?


----------



## MIKELAP

i luvmusic 2 said:


> The reason i asked, originally i was suppoesd to build an adapter for both types of tubes(8 and 9 pin tubes)i ordered parts online then i waited  for nearly a month only to find out that my order was lost.For the meantime while i was waiting for my parts to arrived i bought few pairs of 7 pins including the 6HM5 and during that time i did tried all the tubes that i have on hand and the only two types of tubes that i really like(sound good to me)is the 6HM5 Yugoslavia and 6CS6 Tung-Sol.I got used to the sound  of the 6HM5 and i really like it never used the other tubes since.So before i order parts again(locally this time)i need an opinion regarding the sound of 8 pin tubes.The only concern i have now is the annoying HUM few weeks ago i did build an adapter for 12AU7 and man i tell you the Hum was really really bad.Thanks for your input again THANK YOU!


 
 I  made 8 and 9 pin adapters ive had hum on 8 pin adapters but it was the tubes fault , another thing to ask for before buying octals. Out of 10 tubes i had 2 that hummed some people reported having adapters that hum but i never had that problem and ive made 6 or 7 of them dont know the cause of that is it placement of amp i dont know all i can say is hope for the best.I to recently when back to 7 pin tubes to see how they sounded and i also prefer the 8 and 9 pin tubes especially the octals for there warmth and bass . For me the adventure stops here probably dont really feel the need to go any deeper but who knows what the future holds.Its still a very interesting read


----------



## i luvmusic 2

mordy said:


> Regarding the hum, if you used an external voltage source, connecting one of the low output voltage wires to ground on the chassis of the LD amp may help.
> 
> I also found that using better insulated wires from the adapter to the socket helped, as well as moving around the wires and the socket adapter until the hum disappears or gets lower.
> 
> ...


 
  
 I just touch(it was silent before i touch it) the 7 pin adapter that is installed on the LD 1+ and the hum is there and if i touch the LD 1+ and LD MK III at the same time the hum from LD 1 will disapear could it be a grounding issue?THANK YOU!


gibosi said:


> In my opinion, yes.


 
 THANK YOU!
  


mikelap said:


> I  made 8 and 9 pin adapters ive had hum on 8 pin adapters but it was the tubes falt , another thing to ask for before buying octals. Out of 10 tubes i had 2 that hummed some people reported having adapters that hum but i never had that problem and ive made 6 or 7 of them dont know the cause of that is it placement of amp i dont know all i can say is hope for the best.I to recently when back to 7 pin tubes to see how they sounded and i also prefer the 8 and 9 pin tubes especially the octals for there warmth and bass . For me the adventure stops here probably dont really feel the need to go any deeper but who knows what the future holds.Its still a very interesting read


 
 Before i start making the adapter for Octal i will try to move around my amp (LD 1+) to see if there is a spot that have no or least HUM and then i go from there. THANK YOU!


----------



## gibosi

i luvmusic 2 said:


> Before i start making the adapter for Octal i will try to move around my amp (LD 1+) to see if there is a spot that have no or least HUM and then i go from there. THANK YOU!


 
  
 I suggest you purchase an 8-pin socket and configure it for 6DJ8 and 6CG7 tubes. To run octals, use a simple adapter purchased on line, with octal on top and 6DJ8 on the bottom. This one will work, as the 61NP is pin-compatible with the 6DJ8.
  
 http://www.ebay.com/itm/two-Adapters-6SN7-6N1P-6N1-tubes-SUB-/250751485737?pt=Vintage_Electronics_R2&hash=item3a61f40729


----------



## i luvmusic 2

gibosi said:


> I suggest you purchase an 8-pin socket and configure it for 6DJ8 and 6CG7 tubes. To run octals, use a simple adapter purchased on line, with octal on top and 6DJ8 on the bottom. This one will work, as the 61NP is pin-compatible with the 6DJ8.
> 
> http://www.ebay.com/itm/two-Adapters-6SN7-6N1P-6N1-tubes-SUB-/250751485737?pt=Vintage_Electronics_R2&hash=item3a61f40729


 
 Thanks gibosi! I found the source of the hum it was my furnace and the vector adapter,when the furnace is running some of the tubes would hum.this is a big problem for me.


----------



## mordy

Perhaps running the amp on a different electrical circuit would help.


----------



## siles1991

Elo guys  i'm lovin the progress! Now everyone's into octals? Really tempted to get a pair but the adapters sure do cost a bomb T.T but imo I feel octals will make the LD look more snazzy hahaha gotta love it


----------



## mordy

Hi siles 1991,
  
 If you use an octal tube as a driver (which I assume most people here do) you only need one tube with one socket adapter, but you do need two Vector adapters. The octals are dual triodes, so each tube serves the function of two tubes for our purposes.


----------



## gibosi

I finally received a Tungsram E80CC today. It was marked as shipped from Ukraine on December 28. It arrived in NY on January 4 and sat there until the 26th!
  
 It is a tall tube, similar to the Heerlen-made E80CC, with an O-getter and rhodium pins. According to the vendor, this tube was made in 1967 - date code "3T". But "3T" could also be 1984....
  
 http://www.cathedralstone.net/Tubes/TungsramDCTable.pdf
  

  
 The number "1" is stamped on the small sheet of metal attached to the getter post. (Sorry for the poor phone pic.)
  

  
 And there is a 4-digit code, similar to Philips, etched into the glass close to the base. Unfortunately, I couldn't get the light adjusted properly to photograph it.... Anyway, the code looks like A 3 D 1. However, the D looks more like an upside down U with a dot at the bottom, and the "1" looks like a simple straight line.
  
 Perhaps Oskari will see this post and be able to tell us where and when this tube was manufactured.....


----------



## Oskari

Or perhaps not. 
	

	
	
		
		

		
			




  
 As far as I know, the type was only made by Philips (NL) and Tungsram (H); your tube being of the latter variety.
  
 The rest I can't help with.


----------



## gibosi

Thanks for taking the time to look into this.  
  
 I am inclined to believe the vendor's claim that it is was manufactured in 1967, as the box appears to be from that time frame.
  
 And it does appear that the majority of the tubes on eBay, including Mullard, Valvo, Siemens and Telefunken, were made in one or the other of these factories. However, I have seen a listing for what is claimed to be a Hamburg-made Valvo E80CC:
  
 http://www.ebay.com/itm/1-NOS-NEW-tube-Valvo-Hamburg-E80CC-6085-pinch-waist-D-getter-311040-/380780884667?pt=Vintage_Electronics_R2&hash=item58a84f32bb
  
 And this listing for a Brimar E80CC, which looks nothing like the Holland and Hungary tubes, with a short bottle and black plates, makes me wonder if it might be from old USSR....
  
 http://www.ebay.com/itm/Brimar-E80CC-double-triode-/310673724241?pt=UK_Sound_Vision_Valves_Vacuum_Tubes&hash=item485598d351
  
 Edited: to add the Brimar


----------



## mordy

Hi,
  
 I am now testing my first 12V tube. This tube is from May 1948 and labeled Teletone:


  
 It is an octal tube with black smoked glass. The number 274 indicates that it was made by RCA.
  
 The Teletone Corporation manufactured tube radios and tube television sets from 40's up til 1954. Here is a 1948 tube radio.
  





  
 Teletone is just a blip on the electronic history horizon and their styling and technology apparently were not endearing. Well, I found one example of interesting styling - an Ames radio:
  




  
 Anyhow, mostly forgettable. But how does this 12SN7GT tube sound?
  
 In one word: Delicious. This is the first impression though; need it to simmer for a while.
  
 Happy tube rolling!


----------



## mab1376

If anyone has a spare Tung Sol 6SU7GTY tube with black glass please PM me.
  
 I've emailed a few sellers with no luck and I want a good tube to test out with my new octal adapter.
  
 I have a new production Tung Sol 6SL7GT that has a little bit of background hum to it.


----------



## gibosi

E80CC
  
 After spending more time with the 1961 Holland E80CC and the 1967 Hungary E80CC, I am quite comfortable in saying that these are the best tubes I have. As one might guess, the Holland tube is a tad bit warmer and the Hungary tube is a tad bit airier, but the differences are subtle, and, as a fellow Headfier would say, amount to different shades of grey so to speak. I really don't have a preference for one over the other. They are that good. 
  
 If you have an external heater PS, strongly recommended.


----------



## gibosi

mab1376 said:


> If anyone has a spare Tung Sol 6SU7GTY tube with black glass please PM me.
> 
> I've emailed a few sellers with no luck and I want a good tube to test out with my new octal adapter.
> 
> I have a new production Tung Sol 6SL7GT that has a little bit of background hum to it.


 
  
 While IMO, not quite as good as the Tung Sol, the Sylvania JAN CHS 6SL7WGT with black plates is very good tube, and I see a number of them on eBay at this  time.


----------



## mab1376

gibosi said:


> While IMO, not quite as good as the Tung Sol, the Sylvania JAN CHS 6SL7WGT with black plates is very good tube, and I see a number of them on eBay at this  time.


 
  
  
 Thanks! i'll see if i can snag one!


----------



## Oskari

gibosi said:


> However, I have seen a listing for what is claimed to be a Hamburg-made Valvo E80CC:


 
  
 Ah, thanks. It seems that some early production took place in Hamburg.
  


> And this listing for a Brimar E80CC, which looks nothing like the Holland and Hungary tubes, with a short bottle and black plates, makes me wonder if it might be from old USSR....


 
  
 It looks like a Brimar-made tube (or bottle) to me. I suspect it's not an E80CC, though, but a similar tube labelled as one.


----------



## gibosi

mordy said:


> I am now testing my first 12V tube. This tube is from May 1948 and labeled Teletone:
> 
> It is an octal tube with black smoked glass. The number 274 indicates that it was made by RCA.
> 
> ...


 
  
 It is my understanding that all the 1940s smoked-glass RCAs in this tube family, be they 6SN7GT, 12SN7GT or the 25 volt 1633s, sound essentially identical. And judging from my experience with a 1945 6SN7GT, the word "delicious" sums it up very nicely.


----------



## gibosi

mordy said:


> I believe that you have the Raytheon 6CG7/6FQ7 tube. How does it compare to the tubes you did a shootout on?


 
  
 I was able to compare a US-made Raytheon 6CG7 to a US-made 1940s Raytheon VT-231/6SN7GT. After going back and forth several times, I was unable to discern any significant difference. Since it appears that these tubes have the same innards, I was not surprised. I should note that I do not possess a Japan-made Raytheon 6CG7, so I have no idea how it might compare....
  


Spoiler: Raytheon 6CG7 and 6SN7GT



 









  
 Next, I compared the Raytheon VT-231 with the Holland E80CC. The reason I used the octal, rather than the 6CG7, was that it is much easier. I configured the socket to run the E80CC in 6-volt mode and, using a 6SN7 to 12AU7 adapter on the octal, swapping between tubes was simple and easy. Comparing the E80CC directly to the 6CG7 would have required that I adjust the voltage up, or down, every time.... too much of a hassle....
  
 Anyway, I was quite surprised with what I heard. I have liked the Raytheon since I first heard it, and I still do. However, the Raytheon has a frequency bump in the mid bass region, adding a considerable bass presence to the sound.  Unfortunately, this tends to give the bass kind of a "one-note" sound rather lacking in detail. And further, since the mid bass is front and center, the mids and treble are recessed more than I would prefer. On the positive side, the mids and treble actually sound quite linear, but again, the mid bass bump is problematic, IMHO.


----------



## kvtaco17

So guys... I might make a move to get a WA6 SE... I was listening to my Lyr today with my PS500's and even though my modded LD is quieter, the extra current of the Lyr really makes everything sound bigger. I'm not selling my LD though lol Its got some magic that the Lyr cant touch with my Grados and AD2000x. Someone talk me out of it lol My wallet needs a break lol


----------



## MIKELAP

People so far not to dissuasive hmm !


----------



## kvtaco17

mikelap said:


> People so far not to dissuasive hmm !


 
 looks like I'll have 3 amps in rotation then lol


----------



## MIKELAP

kvtaco17 said:


> looks like I'll have 3 amps in rotation then lol


 
 Wont get bored thats for shure.


----------



## kvtaco17

mikelap said:


> Wont get bored thats for shure.


 
 I did audition the 1540's last weekend... and yeah not sold on them lol


----------



## gibosi

kvtaco17 said:


> So guys... I might make a move to get a WA6 SE... I was listening to my Lyr today with my PS500's and even though my modded LD is quieter, the extra current of the Lyr really makes everything sound bigger. I'm not selling my LD though lol Its got some magic that the Lyr cant touch with my Grados and AD2000x. Someone talk me out of it lol My wallet needs a break lol


 
  
 I am very curious to know how the WA6 SE sounds relative to the Lyr and the LD, so by all means please get one! lol


----------



## kvtaco17

gibosi said:


> I am very curious to know how the WA6 SE sounds relative to the Lyr and the LD, so by all means please get one! lol


 
 I probably will soonish... probably use my tax return cuz I can lol


----------



## MIKELAP

kvtaco17 said:


> I probably will soonish... probably use my tax return cuz I can lol


 
 With which HP would you use the Woo .


----------



## kvtaco17

mikelap said:


> With which HP would you use the Woo .


 
 HD800 and a soon to be purchased unnamed can...
  
 Maybe throw my other cans at it too...  but really the HD800 and maybe a planar or sorts lol


----------



## gibosi

A tall bottle 1944 Sylvania 6SN7A with metal base
  

  
 This tube sounds closer to the Holland E80CC than the Tungsram, with a slightly bigger bass and more slam. The Sylvania 6SN7A / 6SN7W is often described as huge and gorgeous with lots of heft and slam, and in my experience, this is spot on. I am not sure the Syl is technically as accurate as the E80CC, but then I have to admit to a certain degree of disbelief that a 70 year-old tube can be as good as a 50 year-old tube lol.  In the end, given my old ears and modest cans, I can say the differences between the Syl and the Holland E80CC are small, just a slightly different shade of gray, and it's very good. 
  
 The tall bottle 6SN7W and 6SN7A, both with metal bases, are identical. The tall bottle with a black plastic base is likely the same, but I am not sure. The short bottle with a black plastic base is said to be different.
  
 If you are serious about exploring 6SN7s, this is a tube to be on the lookout for, but it can be a budget buster.  Mine carries a Philco label, not Sylvania, so it was priced a bit lower, but even so, it was quite a bit more than $8.00 lol.


----------



## TrollDragon

kvtaco17 said:


> So guys... I might make a move to get a WA6 SE... I was listening to my Lyr today with my PS500's and even though my modded LD is quieter, the extra current of the Lyr really makes everything sound bigger. I'm not selling my LD though lol Its got some magic that the Lyr cant touch with my Grados and AD2000x. Someone talk me out of it lol My wallet needs a break lol


That WA6-SE is getting real close to the Taboo MK III... The Taboo in a nice Walnut case would be my choice.


----------



## rosgr63

Very nice tube Gibosi.
  
 There is no A designation for the 6SN7 only W as far as I know for the Sylvania metal base.
 The A was usually stamped on the dome top but the base markings, packaging etc were 6SN7W.
  
 The micanol base sounds the same as it was the same bottle in a different base.
 The short bottle is different.


----------



## gibosi

rosgr63 said:


> There is no A designation for the 6SN7 only W as far as I know for the Sylvania metal base.
> The A was usually stamped on the dome top but the base markings, packaging etc were 6SN7W.
> 
> The micanol base sounds the same as it was the same bottle in a different base.
> The short bottle is different.


 
  
 Actually, "6SN7GT" is printed on the base of this Sylvania / Philco, and "6SN7A" on top of the bottle, so a bit confusing. But considering the construction and appearance, I knew what it was.


----------



## kvtaco17

I really want a taboo also lol... I demoed one last year and still dream of it... But the WA6se is a bit cheaper... But the lucid modes are so crazy good sounding... Dammit...


----------



## TrollDragon

kvtaco17 said:


> *But the lucid modes are so crazy good sounding...* Dammit...


 
  
 And with the Taboo you can run all your current 6922 / 6DJ8 / 6N1P's

 Just Gorgeous...
  
 You'll have to chase new tubes to roll in the WA6-SE...


----------



## gibosi

kvtaco17 said:


> I really want a taboo also lol... I demoed one last year and still dream of it... But the WA6se is a bit cheaper... But the lucid modes are so crazy good sounding... Dammit...


 
  
 Well, the solution is obvious!  Buy both! lol


----------



## kvtaco17

I do like chasing new tubes...


----------



## gibosi

kvtaco17 said:


> I do like chasing new tubes...


 
  
 Since you would very likely buy new (expensive) tubes for the WA6se, but not for the Taboo, it seems to me that in the end, the total price would be about the same....


----------



## kvtaco17

gibosi said:


> Since you would very likely buy new (expensive) tubes for the WA6se, but not for the Taboo, it seems to me that in the end, the total price would be about the same....


 
 You are correct!
  
 I know what the Taboo sounds like and I love it... the WA6SE intrigues me because it is an unknown...


----------



## mab1376

Did anyone else notice their power tubes glowing a bit brighter with octals?


----------



## MIKELAP

mab1376 said:


> Did anyone else notice their power tubes glowing a bit brighter with octals?


 
 Not here. i have a pair of 6H30PI Electro Harmonix power tubes on and compared to a 6DJ8 looks the same


----------



## i luvmusic 2

I finally got the guts to try another 9 pin adapter it's annoying noisy on LD 1+ but it's  quiet on LD MK III so here it is with 12AU7.


----------



## MIKELAP

i luvmusic 2 said:


> I finally got the guts to try another 9 pin adapter it's annoying noisy on LD 1+ but it's  quiet on LD MK III so here it is with 12AU7.


 
 I like the supercharged alcool burning one on the left lol


----------



## tvrguy

Hi Guys,
  
 I Love my Little Dot MkIII so much that I just just bought a used Raysonic SP120.
 Anyone have any thoughts or information on this piece of tube Nirvana?  
 I heard it, it totally blew me away so I bought it. (and it wasn't for sale)   LMAO!!!
 Has Better Depth and Resolution than my Mark Levinson Gear!
 Need to talk to my Tech to see if he can add a Headphone output.
 Seriously.... this amp almost brought me to tears and I have had a Lot of High End Stuff.
 Awaiting replies from the Collective.
  
 Steve.


----------



## mab1376

mikelap said:


> Not here. i have a pair of 6H30PI Electro Harmonix power tubes on and compared to a 6DJ8 looks the same


 
  
 I have those too, I'll try them out to compare anyway with the octals, the 6N6P-IR are definitely brighter though.


----------



## i luvmusic 2

mikelap said:


> I like the supercharged alcool burning one on the left lol


 
 Me too it give a little wrm to the sound.


----------



## i luvmusic 2

Hi guys any suggestion for 9 pin tubes THANKS!


----------



## mordy

Hi i luvmusic2,
  
 Congrats to your new adapter - I'll drink to that! May I suggest a bottle of Oban Single Malt Scotch - it is rich and full bodied.


----------



## i luvmusic 2

mordy said:


> Hi i luvmusic2,
> 
> Congrats to your new adapter - I'll drink to that! May I suggest a bottle of Oban Single Malt Scotch - it is rich and full bodied.


 
 Thanks Mordy! I should try that.


----------



## mordy

Hi tvrguy,
  
 Hey, you went from a TVR 2500 to a Nissan GT-R! Don't know if it is fair to compare a $200 amp to a $2500 amp.
  
 Truth is, I have not heard of this Canadian designed, made in China amp before, but it gets glowing reviews - enjoy!
  




 Power Handling: 50w x 2 channels
 Frequency Response: 5HZ - 78KHZ +/-1dB
 Display Device: N/A
 Input Sensitivity: 970mv
 Input Impedance: 100kOhm
 Tube Type: KT88 x 4,12AU7 x 2, 6922EH x 1
 Signal-to-Noise Ratio: 96dB
 Inputs: 4 sets
 Outputs: N/A
 Dimensions: 11.9in W x 20.5cm/8.1in H
 Weight: 25kg/55lbs


----------



## gibosi

i luvmusic 2 said:


> Hi guys any suggestion for 9 pin tubes THANKS!


 
  
 I see that your socket is setup for 12AU7. But if you can reconfigure it for 6DJ8, then I recommend an Amperex Orange Globe ECC88 from the late sixties.


----------



## kvtaco17

gibosi said:


> I see that your socket is setup for 12AU7. But if you can reconfigure it for 6DJ8, then I recommend an Amperex Orange Globe ECC88 from the late sixties.


 
 They are very good! Very musical, warm, detailed, extended, and impactful!
  
 Also check out the Voskhod 6n23p the earlier then better (I have a 75, 77 and 78) and the 75 sounds more detailed then the other two. They are more neutral side of warm, have decent sound staging, imaging and are more extended then the Amperex OG's... very different but equally good.
  
 The Mullard 6DJ8 / ECC88 has a more tradition liquid tube sound... it sacrifices some extension and detailed BUT has a pretty gorgeous sound with bright material/cans


----------



## i luvmusic 2

Hi Gibosi,
   this is how i wired the adapter is this same for 6DJ8?
 THANKS!


----------



## kvtaco17

That is for 6DJ8


----------



## i luvmusic 2

kvtaco17 said:


> That is for 6DJ8


 
 THANK YOU!


----------



## MIKELAP

i luvmusic 2 said:


> Hi Gibosi,
> this is how i wired the adapter is this same for 6DJ8?
> THANKS!


----------



## mojorisin35

Anybody have a 1975 Voskhod 6n23p they would sell me? My Russian connection disappeared on me, I had 3 ordered but he close up shop. Thank you gary


----------



## MIKELAP

mojorisin35 said:


> Anybody have a 1975 Voskhod 6n23p they would sell me? My Russian connection disappeared on me, I had 3 ordered but he close up shop. Thank you gary


 
 Ever try 6BQ7A sound good and there cheap.


----------



## i luvmusic 2

mikelap said:


>


 
 Hi Mikelap,
       since i'am using 12AU7 meaning my setup should be like what you have in the picture(12AX7)?Now i'm running 12AU7 on a 6DJ8 setup did i do any harm to my LD?THANKS!


----------



## MIKELAP

i luvmusic 2 said:


> Hi Mikelap,
> since i'am using 12AU7 meaning my setup should be like what you have in the picture(12AX7)?Now i'm running 12AU7 on a 6DJ8 setup did i do any harm to my LD?THANKS!


 
 Exactly, to be honest i dont know . do you have the tube list of the tubes we can use with  our different adapters they are on page 267 i printed that tube list theres the 6DJ8 types ,the 12AX7 and the 6SL7octals i always double check to make shure i dont  use the wrong tube .


----------



## mordy

Hi,
  
 I am using an external voltage regulator. We have been told to shut off the LD amp and wait several minutes (5-10Min?) when changing tubes so that the capacitance of the amp dissipates.
  
 Now, when I have an external source to power the tube heaters, do I have to wait, or can I just shut off the voltage regulator and change tubes right away?


----------



## i luvmusic 2

mikelap said:


> Exactly, to be honest i dont know . do you have the tube list of the tubes we can use with  our different adapters they are on page 267 i printed that tube list theres the 6DJ8 types ,the 12AX7 and the 6SL7octals i always double check to make shure i dont  use the wrong tube .


 
 THANK YOU Mikelap!Yes i will check out Page 267   i feel bad though that i can't used adapter on my LD 1+ due to Noise.I'am looking forward to make my octal adapter as soon as my parts arrive then i will Bug you guys for the schematic for octal adapter.I will stop using 12AU7 on a 6DJ8 adapter  again THANK YOU!


----------



## gibosi

i luvmusic 2 said:


> since i'am using 12AU7 meaning my setup should be like what you have in the picture(12AX7)?Now i'm running 12AU7 on a 6DJ8 setup did i do any harm to my LD?THANKS!


 
  
 No, you have not hurt the LD or the tube. Nothing to worry about.
  
 The only difference between these two configurations is the way pins 4, 5 and 9 are configured. In a 6DJ8 socket, pin 9 is tied to pin 8, the right cathode. But since pin 9 is part of the heater circuit on a 12AU7, you connected the heater to the right cathode!  And yes I can imagine that it was very noisy. lol
  
 And if you will rewire your socket properly for your 12AU7, it will be much quieter.


----------



## gibosi

mordy said:


> I am using an external voltage regulator. We have been told to shut off the LD amp and wait several minutes (5-10Min?) when changing tubes so that the capacitance of the amp dissipates.
> 
> Now, when I have an external source to power the tube heaters, do I have to wait, or can I just shut off the voltage regulator and change tubes right away?


 
  
 I suspect that the reason for this recommendation doesn't have anything to do with the heater circuit. I think it has more to do with the 100 volts or so on the plates. If so, then this recommendation would still be valid. However, this is just a guess on my part.... Perhaps someone else who understands this better will lend his/her advice.....
  
 That said, I have never waited.....


----------



## i luvmusic 2

gibosi said:


> No, you have not hurt the LD or the tube. Nothing to worry about.
> 
> The only difference between these two configurations is the way pins 4, 5 and 9 are configured. In a 6DJ8 socket, pin 9 is tied to pin 8, the right cathode. But since pin 9 is part of the heater circuit on a 12AU7, you connected the heater to the right cathode!  And yes I can imagine that it was very noisy. lol
> re
> And if you will rewire your socket properly for your 12AU7, it will be much quieter.


 
 THANK YOU!I will build one for octal soon so no need for me to rewire.


----------



## MIKELAP

gibosi said:


> I suspect that the reason for this recommendation doesn't have anything to do with the heater circuit. I think it has more to do with the 100 volts or so on the plates. If so, then this recommendation would still be valid. However, this is just a guess on my part.... Perhaps someone else who understands this better will lend his/her advice.....
> 
> That said, I have never waited.....


 
 What i do is shut off Littledot but let volume turned up until music fades away due to lack of current once i dont ear the music i remove the tube.


----------



## MIKELAP

Here are all the schematics Artsi made for different adapters and page 267 with the tubes we can use on those adapters                                                                                                                                                                            
    
 6V tube types
  
 ECC88 6DJ8 6N23P CV5358 M3624        0.35A 33x
 E88CC 6922 CCa CV2492 CV2493 9622  0.30A 33x
 E188CC 7308 CV4108                         0.35A 33x
 E288CC 8223                                    0.47A 25X
 ECC85 6AQ8 B719 6L12                      0.44A 57X
 ECC86 6GM8 6N27P                           0.30A 14X
 ECC189 6ES8                                   0.36A 31X
 ECC804 6GA8 6/30L2                         0.30A 18X
 ECC812                                          0.44A 50X
 ECC865                                          0.44A 58X
 ECC180 6BZ7 6BQ7 6BS8 6T27           0.40A 36X
 6N2P 6CC41                                    0.34A 100X
 6BK7                                              0.45A 40X
 6BC8 6BZ8                                      0.40A 35X
 PCC88 7DJ8                                     0.30A 33X
 6AU7                                              0.30A 20X
 6AX7                                              0.30A 100X
 6BX8                                              0.40A 25X
 6CH7                                              0.40A 36X
 6DT8                                              0.30A 60X
  
  
  
 12V tube types
  
 ECC83 12AX7 B339 95-127-01 6L13 CM1        0.30A 100X
 ECC82 12AU7 B329 95-126-01 CC82E CV491  0.30A 17X
 ECC81 12AT7 B152 CC81E CV455                 0.30A 60X
 E81CC 12AT7WA CV6091 6201                     0.30A 60X
 E82CC 6189 M8136 6189W                         0.30A 17X
 E83CC 12AX7WA 6057                              0.30A 100X
 E180CC CV8431 7062                               0.40A 50X
 E181CC                                                  0.40A 32X
 ECC186 12AU7WA 7316                              0.30A 17X
 ECC802S                                                 0.30A 17X
 5751 GL5751 CK5751 CV4017                      0.35A 70X
 5814A CK5814-A                                      0.35A 17X
 5963 CV3900                                           0.30A 21X
 5965 6829                                               0.45A 47X
 6679                                                      0.30A 60x
 7025                                                      0.30A 100X
 12AD7                                                   0.45A 100X
 12DF7                                                   0.30A 100X
 6680                                                     0.30A 20X
 6211                                                     0.30A 27X
 12AZ7                                                   0.45A 60X
 12AD7                                                   0.45A 100X
 12AV7                                                   0.45A 40X
 12AY7 6N4P                                           0.30A 40X
 12DM7                                                   0.26A 100X
 12DF7                                                   0.30A 100X
 12DT7                                                   0.30A 100X
 12U7                                                     0.30A 20X
 6072                                                     0.35A 44X
 6681                                                     0.30A 100X

Edited by Artsi - 10/21/13 at 1:57pm


                                                                                                                                                                                                                                                                                                                                            


 Here is small list of octal tubes that i could recommend to use with little dot.
  
 Driver octals:
 6SL7GT = VT-229     Classic type
 = CV1985
 6SL7W                    Sylvania
 6SL7WGT                Rugged version with smaller parts
 6SL7WA                  Military version
 6SL7GTB                 Lower base
 6SU7GTY                Better quality and balance? Tung-Sol
 6SU7WGT = 6188     Ruggedized and bantam construction
 ECC35                    European version with 0.4A heater
 6N9S (6H9C)           Russian
 6N9M (6H9M)          Russian mini version
 1579                      Russian, better quality?
 6N9P                     Chinese
 6N9P-T                  Chinese, better quality?
 6113                     Low microphonic?
 5691                     Better quality? 0.6A heater
  
 Power octals:
 6SN7GT = VT-231     Classic
 6SN7GTA                 More power?
 6SN7GTB                 Like -A but with faster heating
 6SN7GTY = CV1988   Better quality?
 6SN7WGTA              Ruggedized and bantam construction
 6SN7W                   Sylvania
 5692                      Better quality?
 6N8S (6H8C)           Russian
 1578                      Russian, better quality?
 6N8P                     Chinese
 6N8P-T                  Chinese, better quality?


----------



## i luvmusic 2

THANK YOU MIKELAP/ARTSI For Posting those schematics and tubes lists!I should be receiving all my parts within next week i ordered it locally this time so hopefully will be here in few days.
 So if I'm going to make one for octal driver tubes adapter which PIN is for the separate Power adapter?


----------



## MIKELAP

i luvmusic 2 said:


> THANK YOU MIKELAP/ARTSI For Posting those schematics and tubes lists!I should be receiving all my parts within next week i ordered it locally this time so hopefully will be here in few days.
> So if I'm going to make one for octal driver tubes adapter which PIN is for the separate Power adapter?


 
 I use those types of adapters Gibosi nows this better than me.


----------



## MIKELAP




----------



## gibosi

mikelap said:


>


 
  
 As you can see from the above pin diagram, you would connect your external heater power supply to pins 7 and 8.


----------



## i luvmusic 2

THANKS! so it will work without separate power adapter reason i asked the Bravo audio Ocean power adapter is 24V-1.5A i'am thinking to used that as power adapter for 6SL7 and i ordered the regulator as will.


----------



## gibosi

i luvmusic 2 said:


> THANKS! so it will work without separate power adapter reason i asked the Bravo audio Ocean power adapter is 24V-1.5A i'am thinking to used that as power adapter for 6SL7 and i ordered the regulator as will.


 
  
 A separate power adapter is not really necessary for 6SL7 tubes. They draw only 300 millamps and the LD can easily provide this much current. So you can connect pins 3 and 4 on one of your Vectors to pins 7 and 8 on your octal socket. 
  
 But 6SN7 draw 600 milliamps and therefore a separate heater power supply is recommended. The Bravo adapter plus a voltage regulator should be perfect.


----------



## i luvmusic 2

So pin 7 and  8 will be disconnected from LD Right socket pin 3 and 4 and can you please let me know which pin should i connect the Positive and negative(PIN 7 or 8) from power regulator sorry for all these questions i don't have much knowledge in Electronics/Electricity Again THANK YOU!


----------



## i luvmusic 2

gibosi said:


> A separate power adapter is not really necessary for 6SL7 tubes. They draw only 300 millamps and the LD can easily provide this much current. So you can connect pins 3 and 4 on one of your Vectors to pins 7 and 8 on your octal socket.
> 
> But 6SN7 draw 600 milliamps and therefore a separate heater power supply is recommended. The Bravo adapter plus a voltage regulator should be perfect.


 
 Since i have the regulator on the way and i have the power adapter on hand mind aswell used it.Thank You!


----------



## gibosi

i luvmusic 2 said:


> So pin 7 and  8 will be disconnected from LD Right socket pin 3 and 4 and can you please let me know which pin should i connect the Positive and negative(PIN 7 or 8) from power regulator sorry for all these questions i don't have much knowledge in Electronics/Electricity Again THANK YOU!


 
  
 Fortunately, polarity does not matter.


----------



## i luvmusic 2

gibosi said:


> Fortunately, polarity does not matter.


 
 THANK YOU!


----------



## i luvmusic 2

THANK YOU GUYS FOR YOUR HELP!


----------



## TrollDragon

I'll throw my 2 peso's in here as I know you guys just like hearing my wet blanket, err on the side of caution opinion...

When you shut off the LD there is still high voltage in the capacitors that takes a minute or two to discharge. This is why you still hear music after the amp shuts off and the tubes cool.

Yanking out tubes when the amp is immediately shut off will stress the board components unnecessarily.

I always turn the amp on without headphones plugged in, I allow it to warm up for a few minutes then with the volume at zero, plug my headphones in. When tuning the amp off I always bring the volume to zero, unplug my headphones and then turn the amp off. I wait 5 minutes before changing tubes, then repeat the above turn on sequence.

The less stress to the amp and my headphones, I feel should be taken into consideration. Call me OCD or anal retentive but I am not really interested in taking chances just to flip a $5 tube. I always test new tubes with crap heaphones, I have a pair of $9 JVC RX300's that I use.

This has been my opinion for this question and you know what they say about opinions...


----------



## MIKELAP

trolldragon said:


> I'll throw my 2 peso's in here as I know you guys just like hearing my wet blanket, err on the side of caution opinion...
> 
> When you shut off the LD there is still high voltage in the capacitors that takes a minute or two to discharge. This is why you still hear music after the amp shuts off and the tubes cool.
> 
> ...


 
 Better safe than sorry!


----------



## hypnos1

Hi guys.
  
 Just thought I'd butt in, even though I confess I haven't been joining the octal odyssey - to my shame! In my defence - and to my 'grand chagrin' that no-one else seems to have given them a try -  with a good many more hours on them, these C3gs have done incredible things for my MKIV SE (with 6N30P-DRs). I can honestly say the leap is not just that from 6HM5/6CS6 to some VERY good '6DJ8s', but from the stock 8100s - if not even greater!! And this holds true for EVERY piece of music I have been using for comparison these past many months. Can this be surpassed? Possibly... but...
  
 Whatever, I can only hope y'all are experiencing the same joy that I now get from this humble machine.
  
 Happy rolling, everyone...


----------



## gibosi

hypnos1 said:


> Hi guys.
> 
> Just thought I'd butt in, even though I confess I haven't been joining the octal odyssey - to my shame! In my defence - and to my 'grand chagrin' that no-one else seems to have given them a try -  with a good many more hours on them, these C3gs have done incredible things for my MKIV SE (with 6N30P-DRs). I can honestly say the leap is not just that from 6HM5/6CS6 to some VERY good '6DJ8s', but from the stock 8100s - if not even greater!! And this holds true for EVERY piece of music I have been using for comparison these past many months. Can this be surpassed? Possibly... but...
> 
> Whatever, I can only hope y'all are experiencing the same joy that I now get from this humble machine.


 
  
 Unfortunately, I suspect that many of us, myself included, are a bit daunted by the task of building a proper set of adapters, plus the cost of a pair of C3gs. Perhaps you should consider starting a cottage industry? Perhaps "C3gLD" would be a good name? lol 
  
 For sure, I can't help but wonder how these compare to the E80CC....


----------



## mab1376

hypnos1 said:


> Hi guys.
> 
> Just thought I'd butt in, even though I confess I haven't been joining the octal odyssey - to my shame! In my defence - and to my 'grand chagrin' that no-one else seems to have given them a try -  with a good many more hours on them, these C3gs have done incredible things for my MKIV SE (with 6N30P-DRs). I can honestly say the leap is not just that from 6HM5/6CS6 to some VERY good '6DJ8s', but from the stock 8100s - if not even greater!! And this holds true for EVERY piece of music I have been using for comparison these past many months. Can this be surpassed? Possibly... but...
> 
> ...


 
  
 Can you post a pin out for your adapters if you haven't already?


----------



## hypnos1

Gibosi.
  
 I can fully understand the hurdles you mentioned - IF ONLY we had discovered these C3gs a while ago, before spending money exploring so many of the 6DJ8 family...we would still be less out-of-pocket! Ah...hindsight...Especially as I missed out on 8! tubes (used) at Christmas - can now kick myself REAL hard, they went for about $8 each if I remember rightly!! At that price I would have gladly made up some adapters and shared them amongst my fellow masochists, if only to check whether I am hallucinating re. my findings! But as I am sure I am NOT, I would love to share the magic I have been enjoying for a while now. Perhaps some more cheapies will appear at some time in the future...who knows? (Would _love_ to know who got them and to what use - or rather _in_ what). Then I could at least send them on the 'rounds', for people to compare - such as with your E80CCs, etc.
  
 Ah well, we wait and see...live in hope, lol.


----------



## hypnos1

Mab.
  
 I did in fact post pin layout, with corresponding EF95's on page 312. Hopefully that may be useful to you...


----------



## gibosi

trolldragon said:


> I always turn the amp on without headphones plugged in, I allow it to warm up for a few minutes then with the volume at zero, plug my headphones in. When tuning the amp off I always bring the volume to zero, unplug my headphones and then turn the amp off. I wait 5 minutes before changing tubes, then repeat the above turn on sequence.


 
  
 Actually, I don't deviate too much from this regimen. However, when I am doing A/B comparisons of two tubes, I probably wait about 2 or 3 minutes, rather than 5. Also, when rolling 6DJ8 tubes, I find that if I take the volume all the way to zero, there is a strong ground hum, so I take it down to around one or two. I do not experience this with any other tube and suspect it is due to parasitic oscillation as this is a known problem with 6DJ8.


----------



## gibosi

The other day, I received a 1953 Sylvania "Chrome Dome."
  

  

  
 The eBay vendors often refer to any tube with top getter splash as a "Chrome Dome". However, it is my understanding that this is the tube people were looking at when the term "Chrome Dome" was coined. You will notice that virtually the entire bottle is "chromed". Further, the demarcation between the getter splash and clear glass is rather ragged and defuse. On most of the other tubes with top getter splash, that demarcation is crisper and straighter. Peering inside, I can see the same 3-hole black plates as the Sylvania 6SN7W, but no copper support rod.
  
 Unfortunately, I have not spent much time with this tube, but in a quick A/B comparison with the metal-base Sylvania 6SN7W, I noticed a strong resemblance. While not exactly the same, it is quite similar, a slightly different shade of gray so to speak, and if you like that sound signature, I think you would also like this tube. I should note that a number of posters over on the 6SN7 Addicts thread rate this tube quite highly, in their top 5.


----------



## i luvmusic 2

Just checked the status of my parts order and it should arrive this tuesday or wednesday.any suggestion which 6SL7 i should get.


----------



## chiman

I got my 6HM5 today. When turning on the amp one flashes up but the other doesn't, just wanted to know if this is ok? Thanks.


----------



## i luvmusic 2

chiman said:


> I got my 6HM5 today. When turning on the amp one flashes up but the other doesn't, just wanted to know if this is ok? Thanks.


 
 I would not worry about it as long as it sound the same with the other tube.I bought 8 tubes and 2 of them does not not flash.


----------



## JoeDoe

Anyone have lengthy experience with GE JAN Blackplates for the LD1+?
  
 Got a pair yesterday that I love for the soundstage and warmth but the bass is a bit muddy. Will this improve with burn in?


----------



## mordy

Hi,
  
 If you need a pair of top quality small speakers for a real bargain price of $72 shipped, look at these:
  
 http://www.newegg.com/Product/Product.aspx?Item=N82E16882117406&clickid=xu7W8i02X1eRXDXyMJwbPUm5UkTyAqX5z1jCQM0&iradid=97618&ircid=2106&irpid=10577&nm_mc=AFC-IR&cm_mmc=AFC-IR-_-na-_-na-_-na
  
 I have these speakers, and they are very good - get 5 star reviews on Amazon and Newegg; well rated by Stereophile.


----------



## i luvmusic 2

finally i received my parts today and made a 6SL7 adapter.I'am listening to it right now and it blow my mind really good.


----------



## i luvmusic 2

When i just turned on my LD 1+ with the 6SL7 there was a slight hum after one hour i turn the volume to zero the hum was gone now it's dead quiet.


----------



## mojorisin35

It is 8am and my Amperex OG 6DJ8 with my beyerdynamic dt 1350’s have me rocking and causing my co workers to pause and smile. 
 WOW the 6DJ8 family is something else! 
  
 This morning’s muse turn it up and hang on:
 Xavier Rudd Footprints


----------



## gibosi

Yesterday I received a 1945 small-bottle Sylvania 6SN7W.
  

  
 It has the same 2-hole plates and support rod as the metal-base, tall bottle 6SN7W. There is a small crack in the base, but it appears not to be a problem as the bottle is not loose.
  


Spoiler: Tall bottle metal Sylvania 6SN7W






  
 I have not had a chance to compare it to the metal tall bottle or chrome dome, but I did have a chance to listen to it for about an hour last night, and feel it has strong detailed bass, smooth mid range and clean extended highs similar to the other two Sylvanias. Comparing these three tubes is on my very, very long to-do list, but for now, I am simply enjoying this tube.


----------



## mab1376

I received my 1955 Sylvania 6SL7WGT tube today and notice some hum on this tube as well. It is most prominent around 12 o'clock on the volume pot for some strange reason.


----------



## MIKELAP

mab1376 said:


> I received my 1955 Sylvania 6SL7WGT tube today and notice some hum on this tube as well. It is most prominent around 12 o'clock on the volume pot for some strange reason.


 
 I think i mentionned this before i to for some reason have a couple of the 6SL7 tubes that  have a slight hum and others nothing have you tried moving your amp around .The hum on mine is constant volume doesnt change anything but  at 9 oclock i dont ear it anymore when i pla y music its not loud. i made an adapter with a shielded usb cable grounded to adapter chassis and that didnt help hum is still the same with that tube so maybe its about the tubes who knows .


----------



## mab1376

mikelap said:


> I think i mentionned this before i to for some reason have a couple of the 6SL7 tubes that  have a slight hum and others nothing have you tried moving your amp around .The hum on mine is constant volume doesnt change anything but  at 9 oclock i dont ear it anymore when i pla y music its not loud. i made an adapter with a shielded usb cable grounded to adapter chassis and that didnt help hum is still the same with that tube so maybe its about the tubes who knows .


 
  
 well so far two out of two have the buzz, its barely noticeable with music playing but on quiet parts its noticeable. What tubes do you have that have no buzz?


----------



## MIKELAP

mab1376 said:


> well so far two out of two have the buzz, its barely noticeable with music playing but on quiet parts its noticeable. What tubes do you have that have no buzz?


 
 6H9C Russian tubes and Sylvanias and Tung Sol 6SL7 the one i have that hums is my best one the Tung-Sol 6SU7GT and a black glass i have to identical one hums and the other doesnt atleast i dont ear it when music plays because they sound very good


----------



## mab1376

The Sylvania 6SL7WGT I have from 1955 hums less and does sound amazing, the sound stage and instrument separation are amazing compared to the 6AV6 and 6HM5 tubes i've been using. The new production TS 6SL7GT from '05 I have hums a bit more and sounds OK, but nothing mind blowing.
  
 Its really troubling me what is causing the humming, as you tried grounding isn't the issue.
  
 I don't know what im looking at but does the little dot reach these specs sufficiently or may over by too much?


----------



## MIKELAP

mab1376 said:


> The Sylvania 6SL7WGT I have from 1955 hums less and does sound amazing, the sound stage and instrument separation are amazing compared to the 6AV6 and 6HM5 tubes i've been using. The new production TS 6SL7GT from '05 I have hums a bit more and sounds OK, but nothing mind blowing.
> 
> Its really troubling me what is causing the humming, as you tried grounding isn't the issue.
> 
> I don't know what im looking at but does the little dot reach these specs sufficiently or may over by too much?


 
 As far as i know its safe to use those or else i wouldnt risk it. Heater current is .300 amp thats well within the max. 500 amp The thing is maybe and im speculating here those tubes arent really made for what we are using them for . also another thing i noticed usually when i touch the adapter i ear a radio station lol but when music is playing no problem . Maybe somebody could explain these things we notice with these tubes .


----------



## TrollDragon

mab1376 said:


> The Sylvania 6SL7WGT I have from 1955 hums less and does sound amazing, the sound stage and instrument separation are amazing compared to the 6AV6 and 6HM5 tubes i've been using. The new production TS 6SL7GT from '05 I have hums a bit more and sounds OK, but nothing mind blowing.
> 
> Its really troubling me what is causing the humming, as you tried grounding isn't the issue.


 
 From the interwebs... "6v octal preamp tubes (6SC/L/N7)are more prone to hum than 12v noval preamp tubes (12AX/T/Y/U7)"
 The octals are more microphonic than other tubes as well for some reason.
  
 Here is a little test I read about, wrap a piece tinfoil around the whole tube and base from top to bottom and then ground the tinfoil to the chassis to see if the hum goes away.
 Also it is highly recommended to have a DC heater when using octals as preamps to try and get rid of the hum.


----------



## gibosi

I have only two 6SL7s, a Tung-Sol 6SUL7GTY, with black glass, and a Sylvania GB-6SL7WGT, and both are completely silent. And I can add that all the 6SN7s I have tried are also completely silent. However, I am using an external DC heater power supply, which tends to be quieter than the LD's internal AC heater supply.
  
 The cathode voltage tends to be a little lower than desired when using 6SL7s in our Little Dots. However, if the cathode voltage is too low, it is my understanding that this would manifest itself as distortion, not as a ground hum. My best guess is that the hum you are hearing is due to the heater power supply, but again, this is only guess. Mordy has used 6SL7s, both with and without an external power supply. Perhaps he would be willing to add his two cents.


----------



## mab1376

gibosi said:


> I have only two 6SL7s, a Tung-Sol 6SUL7GTY, with black glass, and a Sylvania GB-6SL7WGT, and both are completely silent. And I can add that all the 6SN7s I have tried are also completely silent. However, I am using an external DC heater power supply, which tends to be quieter than the LD's internal AC heater supply.
> 
> The cathode voltage tends to be a little lower than desired when using 6SL7s in our Little Dots. However, if the cathode voltage is too low, it is my understanding that this would manifest itself as distortion, not as a ground hum. My best guess is that the hum you are hearing is due to the heater power supply, but again, this is only guess. Mordy has used 6SL7s, both with and without an external power supply. Perhaps he would be willing to add his two cents.


 
  
 it sounds more like radio static than a ground hum, i think you're onto something here.
  
 Do you have ebay links to the voltage regulator and breadboard i would need to make a powered adapter?


----------



## gibosi

mab1376 said:


> it sounds more like radio static than a ground hum, i think you're onto something here.
> 
> Do you have ebay links to the voltage regulator and breadboard i would need to make a powered adapter?


 
  
 All you need is a voltage regulator and an AC to DC adapter. You may already have a suitable AC adapter. I am using a 24VDC adapter that came with an old cordless drill/driver. So if you have an adapter putting out 15V or more (to allow you to use 12 volt tubes as well) you are good to go. And I bought my regulator here:
  
  http://www.ebay.com/itm/131062144956?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649


----------



## mordy

Hi mab1376,
  
 Please look at the page 301 post 4507 where you have a guide to make an adapter using a breadboard.
  
 There are many sources for a voltage regulator - can be bought for less than $5. In retrospect I would look for one from China rather than Hong Kong since it took 30 days to arrive from HK. Get one with a LED volt meter.
  
 http://www.ebay.com/itm/DC-Step-Down-Converter-Module-LM2596-Voltage-Regulator-Led-Voltmeter-SSY-2510-/221302164468?pt=LH_DefaultDomain_0&hash=item3386a30bf4
  
 This is one link of many. You can get it a little cheaper, but shipping time may be shorter from China.


----------



## gibosi

Disconnect the wires currently connecting the LD's AC heater (Vector pins 3 and 4) to the 9-pin socket, pins 4 and 5 (or if you are using an octal socket, pins 7 and 8).
  
 Run wires from the voltage regulator OUT to pins 4 and 5 on the 9-pin socket (pins 7 and 8 on an octal socket), and connect negative OUT to chassis screw to establish a common ground.


----------



## mordy

Hi Gibosi,
  
 I use an external PS with a grounded voltage regulator as per your advice, and I do not have any major problems with hum using 6SL7 or 6SN7 octals (or any other tubes for that matter).
  
 Since I listen through speakers, I run my LD KMIII at the highest volume without clipping, and keep the volume low on my power amp (110W ss). If I play very loud  (louder than I need), there is a hum, but it is drowned out by the music, and I can only hear it with nothing playing and turning up the volume very loud.
  
 Even though the 6SL7 is a very nice tube, I find that the 6SN7 is a better sounding tube for me. The 6SN7s are plentiful, and I am able to buy tubes for $4 - 9 (incl shipping). I have a couple of Sylvanias form the 50's that are just plain wonderful sounding. They are so good that I am almost tempted to stop looking for better, although I have another tube that is exceptional - have to do a shoot-out before I report. And yes, this tube is also very inexpensive.
  
 I do note that the Little Dot MK9 uses a Chinese variant 6H9C of the 6SL7 family as the driver tube.
  
 It has been a three year odyssey for me to find these tubes.  It was a lot of fun and excitement to explore dozens and dozens of tubes to reach this level, but in one way I wish I would have known about them earlier and how to use them with the LD amps.
  
 But I guess that you wouldn't really appreciate these tubes unless you went through all the trouble, experimenting and searching. In the words of my old dentist: "If I knew how fun grand children were, I would have had them first."


----------



## mab1376

mordy said:


> Hi mab1376,
> 
> Please look at the page 301 post 4507 where you have a guide to make an adapter using a breadboard.
> 
> ...


 
  
 Is this the right vector adapter?
  
 http://www.radiodaze.com/product/15450.aspx
  
 I ordered this: http://www.ebay.com/itm/8-pin-octal-breadboard-prototype-tube-socket-for-DIY-experimenting-/150913780305?ssPageName=ADME:L:OC:US:3160
  
 and this: http://www.ebay.com/itm/DC-Step-Down-Converter-Module-LM2596-Voltage-Regulator-Led-Voltmeter-SSY-2510-/221302164468?ssPageName=ADME:L:OC:US:3160
  
 so far.
  
 I just need to but some wire and find a power supply (which I'm sure i have one somewhere, at least 12v).


----------



## gibosi

mab1376 said:


> Is this the right vector adapter?
> 
> http://www.radiodaze.com/product/15450.aspx


 
  
 Yes.
  
 And I am curious...  What is your current setup for listening to octals?


----------



## mab1376

gibosi said:


> Yes.
> 
> And I am curious...  What is your current setup for listening to octals?


 
  
 Sweet, all parts ordered, just need to find a PSU and get some wire.
  
 I bought an adapter off MIKELAP, it just has the buzz issue so i wanna take the DIY route with the PSU to see if that fixes it.


----------



## mordy

U got all the parts right. I am sure u have a little flat blade screwdriver for the breadboard.
  
 The wires I use I got from an old computer power supply. Most anything will do.
  
 Make sure you read about how to handle the Vector adapters in the post on page 301.
  
 I think that an old laptop adapter would do fine as well since they usually are rated for around 20V.
  
 Good luck!


----------



## mab1376

mordy said:


> U got all the parts right. I am sure u have a little flat blade screwdriver for the breadboard.
> 
> The wires I use I got from an old computer power supply. Most anything will do.
> 
> ...


 
  
 Thanks, i'm sure i have some old power adapters around to use.
  
 Thanks for the tip on the adapters, i would be irritated if they came apart and i wasn't able to get them back together.


----------



## Artsi

I finished my latest DIY amp. It uses one 6X5GT as rectifier, two 6SN7 powertubes and one octal socket for driver. I optimized this to use 6SL7 tubes as driver, cathode resistor 1.5k and to anode through 68k. No feedback connection.
  
 After listening a while this amp with Tung-Sol 6SU7GTY i have realized how badly little dot is suitable for 6SL7 tubes. With little dot 6SL7 tubes work very limited way. With 6SL7 optimized amp 6SU7GTY tube sounds insanely good, it gives so much details, that i get chills. Music sounds weird, this amp will dig out all the little things from music, that i have not even noticed before. This is going to take time to get used to. Now i can focus on adjusting my other DIY tube amps even better.
  
 In brief i suggest to use 6SN7 tubes with little dots. 6SL7 tubes are much more sensitive to any electric interference, and they won't sound as good how they could sound.


----------



## mab1376

artsi said:


> I finished my latest DIY amp. It uses one 6X5GT as rectifier, two 6SN7 powertubes and one octal socket for driver. I optimized this to use 6SL7 tubes as driver, cathode resistor 1.5k and to anode through 68k. No feedback connection.
> 
> After listening a while this amp with Tung-Sol 6SU7GTY i have realized how badly little dot is suitable for 6SL7 tubes. With little dot 6SL7 tubes work very limited way. With 6SL7 optimized amp 6SU7GTY tube sounds insanely good, it gives so much details, that i get chills. Music sounds weird, this amp will dig out all the little things from music, that i have not even noticed before. This is going to take time to get used to. Now i can focus on adjusting my other DIY tube amps even better.
> 
> In brief i suggest to use 6SN7 tubes with little dots. 6SL7 tubes are much more sensitive to any electric interference, and they won't sound as good how they could sound.


 
  
 Got any pics? sounds interesting, i'd love to see your work.
  
 Do you feel tube rectification provides any benefit?


----------



## Artsi

mab1376 said:


> Got any pics? sounds interesting, i'd love to see your work.
> 
> Do you feel tube rectification provides any benefit?


 
http://kuvaton.com/k/yYqo.jpg Needs some paint...
  
 Chassis is way too small! And there is inside transformer, 15H choke etc. Do not know is there any benefit to use tube rectifier, but it makes electric field and many 6SL7 tubes are rather sensitive to it. At least with tube rectifier amp does not seem to sound worse than with diodes.
  
 Amp uses AC heaters without any problem.


----------



## mab1376

artsi said:


> http://kuvaton.com/k/yYqo.jpg Needs some paint...
> 
> Chassis is way too small! And there is inside transformer, 15H choke etc. Do not know is there any benefit to use tube rectifier, but it makes electric field and many 6SL7 tubes are rather sensitive to it. At least with tube rectifier amp does not seem to sound worse than with diodes.
> 
> Amp uses AC heaters without any problem.


 
  
 I've been looking to upgrade to the LD MK VI+ vs the WA22 and a lot of poeple said you lose some power with a tube rectifier which is a downfall if you're going to orthos like I plan to, but if you're using something high impedance in an OTL topology its up in the air whether its better or worse for SQ.


----------



## mordy

Hi Artsi,
  
 Is the amp base a cooking pot or a cover for a heating urn?
  
 Interesting that I discovered that 6SN7 tubes sounded better than 6SL7 tubes in the Little Dot just by listening.
  
 Also interesting that the new Little Dot MK9 uses a Chinese variant of the 6SL7 as driver.


----------



## rosgr63

Rectifier tubes don't suffer from Solid State switching noise.
  
 In some amps some people can hear it.


----------



## mab1376

rosgr63 said:


> Rectifier tubes don't suffer from Solid State switching noise.
> 
> In some amps some people can hear it.


 
  
 Have you seen anything that compared both side by side and measured the noise? I really like the WA22's design since it has all the luxury amenities such as the DACT attenuator and if nothing else the tube rectifier looks cool, but from $775 to $1900 i don't think i can justify it. Other than that the MK VI+ can use the same 6SN7/6SL7 driver tubes with 6080/6as7g/5998 power tubes.
  
 sorry if I'm rambling the subject has just always intrigued me.


----------



## rosgr63

Personally I haven't.
  
 But I have two friends who tried it and could hear the switching noise.
 They did not carry out any measurements.
  
 Some of my amps use SS and others tube rectification and all sound good to me.


----------



## i luvmusic 2

What voltage should i set my external PS for 6SL7/ 6SN7 and can i use 6SN7 as a driver tube?


----------



## gibosi

i luvmusic 2 said:


> What voltage should i set my external PS for 6SL7/ 6SN7 and can i use 6SN7 as a driver tube?


 
  
 Yes, you can use both the 6SL7 and the 6SN7 as driver tubes. In fact, the 6SN7 is a better driver tube in our LDs than the 6SL7. These are 6.3 volt tubes, so set your PS accordingly.


----------



## i luvmusic 2

gibosi said:


> Yes, you can use both the 6SL7 and the 6SN7 as driver tubes. In fact, the 6SN7 is a better driver tube in our LDs than the 6SL7. These are 6.3 volt tubes, so set your PS accordingly.


 
 THANK YOU VERY MUCH!!


----------



## Artsi

mordy said:


> Hi Artsi,
> 
> Is the amp base a cooking pot or a cover for a heating urn?
> 
> ...


 
 We had spare 180mm diameter aluminium block at work and i lathed it to amp chassis. 250mm would have been much better, this was too small.
  
 Those chinese 6SL7 variants are either russian copies or even made with old russian machinery. I'm pretty sure that MK9 should work fine with 6SN7 as driver too.


----------



## gibosi

I received a gray smoked-glass National Union 6SN7GT yesterday. These were manufactured earlier than the more common black smoked-glass tubes, prior to 1949 I believe. At first glance, one might think this tube is an RCA from the same time period. However, there are two distinguishing characteristics. Both the RCA and the NU have mica spacers attached to the top mica, similar to the those on the TungSol mouse ears. However, in the RCA they are rectangular in shape, whereas in the NU they are square. But the most noticeable difference is the NU has U-shaped structures, used to spring-load the plates, located on the top mica, similar to the TungSol BG/RP.
  
 The vendor didn't know anything about this tube and as I didn't know what it was either, I asked rosgr63 if he would be kind enough to take a look. So I got 5 tubes for $99 including a TungSol BG/RP, Sylvania VT231, Raytheon VT231 and a GE 6SN7GTA. For $25 a tube, I am pleased. 
  
 I listened to it for a while last night and found it very enjoyable. (But it seems I find almost all the 6SN7s enjoyable! lol ). As others have written, it has a lush and somewhat forward mid range, with good bass and treble. Comparing this to the black-glass version has now been added to my very, very long to-do list. If you stumble across one of these at a good price, as I did, I think you will find it to be a very nice tube.


----------



## i luvmusic 2

Which side i need to connect the ground wire from LD chassis  to Voltage Regulator In or out?


----------



## rosgr63

This is a rare tube, a nice and lucky find which you are going to enjoy.
  
 Better sounding IMHO than the later NU with the black glass coating.


----------



## gibosi

i luvmusic 2 said:


> Which side i need to connect the ground wire from LD chassis  to Voltage Regulator In or out?


 
 Out, like so:


----------



## i luvmusic 2

gibosi said:


> Out, like so:


 
 THANK YOU! I'am almost done with the adapter again THANK YOU!


----------



## gibosi

rosgr63 said:


> This is a rare tube, a nice and lucky find which you are going to enjoy.
> 
> Better sounding IMHO than the later NU with the black glass coating.


 
  
 And again, thanks for ID-ing this tube for me before I purchased it! I do indeed feel very fortunate to have stumbled on this tube for such a good price.
  
 After doing a very quick A/B comparison between the gray glass and black glass, I think I prefer the gray glass, as well. While I find the black glass to have a very beautiful sound, it is rather dark with a fairly heavy bass presence. The gray tube has a much more balanced tonal balance, from top to bottom. Since I have only one tube in my system, I do not have the luxury of matching two different 6SN7s to adjust tonal balance. For example, I have read that combining the strong bass of the black glass NU with the weaker bass but better mids and highs of the Sylvania VT231 often works very well. But in my system, one tube has to do it all, and the gray glass is the clear winner.


----------



## rosgr63

Please don't thank me, I am more than happy to help whenever I can.
  
 You are right by combining tubes you can get the benefits of different variants or types.
 However you can get lots of enjoyment by rolling just the driver, some amps respond very well to it depending on the design.


----------



## mordy

Hi Gibosi and rosgr63,
  
 I find it fascinating to read about combining two driver tubes, because this has been on my mind for quite a while. My present set up is a breadboard with an external PS using a dual triode of the 6SN7 family via 2 Vector adapters plugged into the LD MKIII.
  
 If I have the 7 pin Vector sockets available to plug in two 7 pin tubes such as the 6HM5, and they are powered by the LD, is there anything untoward preventing me from trying this?


----------



## gibosi

mordy said:


> Hi Gibosi and rosgr63,
> 
> I find it fascinating to read about combining two driver tubes, because this has been on my mind for quite a while. My present set up is a breadboard with an external PS using a dual triode of the 6SN7 family via 2 Vector adapters plugged into the LD MKIII.
> 
> If I have the 7 pin Vector sockets available to plug in two 7 pin tubes such as the 6HM5, and they are powered by the LD, is there anything untoward preventing me from trying this?


 
  
 Mordy, I think fire and smoke is quite possible resulting from plugging anything into the Vectors while your 6SN7 is also running. Further, I doubt that the LD can support two stages of driver tubes without a huge amount of modification. However, what is very possible is using the one 6SN7 with external heater PS as a driver and then installing a pair of 6CG7/6SN7 as power tubes.
  
 I remember that you tried using 6CG7s as power tubes driven by a single 6SL7, but that was not optimal, largely due to the 6SL7's borderline compatibility in the LD, I suspect. But running 6CG7/6SN7 in both the driver and power positions could work quite well.


----------



## i luvmusic 2

Hi everyone,
   I Just tried running my  LD 1+ with  3 driver Tubes 1 6SL7 with separate PS and 2   6J1 so far no fireworks and no magic smoke.


----------



## mordy

I felt that using the 6CG7 tubes as power tubes ruined both the drive tube and the 6CG7 power tubes. The plate voltage was in the area of 218V. The heater voltage on my favorite 12AX7 tube read 0.34V on one side after this experiment.
  
 I recall a comment that the 6CG7 is not compatible with the LD MKIII but the 6FQ7 is (perhaps from the Little Dot Forum).
  
 Too scared to try the 6FQ7 as power tubes.
  
 I have to wait for another way to combine tubes safely.


----------



## mordy

Hi i luvmusic2,
  
 Congratulations! Looks really neat! Now, I have the LD MKIII, so it is not exactly the same setup. If somebody can vouch for the safety of my MKIII amp I would definitively try it.
  
 The BIG question: How does it sound? Is there a real improvement?
  
 Next: Your voltage regulator looks the same as mine. I am not able to adjust the LED readout to read 6.3V. The closest I get is 6.27V.  However, it seems that the LED readout is stepped, because I get 6.27V and next 6.43V. However, you can still turn the set screw within the 6.27V readout and see different voltages as measured at the output terminals on the voltage regulator. After a little fiddling and measuring with my multimeter, I can get a steady 6.30V. Sometimes the voltage fluctuates as measured, but minimally  (6.29 - 6.31V) - not that it should matter much.


----------



## i luvmusic 2

mordy said:


> Hi i luvmusic2,
> 
> Congratulations! Looks really neat! Now, I have the LD MKIII, so it is not exactly the same setup. If somebody can vouch for the safety of my MKIII amp I would definitively try it.
> 
> ...


 
 IMO None.


----------



## i luvmusic 2

Hi Mordy,
    I just tried my LD MK III running combined Driver tubes(same setup with my LD 1)again nothing happened no fireworks and no smoke,about the sound  IMO No changes . I hope these Help.
  

  

  

  

  
 Thanks!


----------



## mordy

Hi i luvmusic2,
  
 Thanks for trying the three driver setup on the MKIII. I was really hoping that there would be a sonic benefit, but you state that it did not make a difference. Maybe a different combination of tubes would change things.
  
 Thanks for the help.


----------



## TrollDragon

Haphazardly running random tubes in parallel is very careless and will prove to be entertaining...


----------



## mordy

HI TD,
  
 Is this the entertainment you mean?


----------



## i luvmusic 2

I will try 6HM5 and 6SL7 as a Driver tube on LD MK III.wish me LUCK,someone has to try it right. 'll be back in a minute.


----------



## TrollDragon

No I mean this kind of entertainment...

[VIDEO]http://youtu.be/PLs7p0_1w8U[/VIDEO]

This was from a bad capacitor but similar things can happen when good parts are overdriven.


----------



## i luvmusic 2

I'm back,No worries LD 1,LD MK III and i are OK.Just tried 6HM5 and 6SL7 combined driver tubes with my LD1 and LD MK III and still no changes in sound and no fireworks.That's enough for me before i hurt my self.


----------



## gibosi

mordy said:


> I felt that using the 6CG7 tubes as power tubes ruined both the drive tube and the 6CG7 power tubes. The plate voltage was in the area of 218V. The heater voltage on my favorite 12AX7 tube read 0.34V on one side after this experiment.
> 
> I recall a comment that the 6CG7 is not compatible with the LD MKIII but the 6FQ7 is (perhaps from the Little Dot Forum).
> 
> ...


 
  
 Mordy,
  
 The only difference between a 6CG7 and a 6FQ7 is the former has a shield and the latter does not, so if one is compatible then the other one is too. The 6SN7 is perfectly happy with a plate voltage of 250V, so 218V is well within spec. And the heater voltage for the 6SN7 is now controlled via your external PS, so that is no longer an issue. However, I certainly understand your reluctance.....
  
 But I will say that this is far and away much safer than running two 7-pin tubes in parallel with your 6SN7!!!


----------



## rosgr63

Mordy, what about using two 1/2 6SN7's so many variants out there.
  
 Or even two 6SJ7's strapped in triode mode?
  
 I have used both the 6CG7 and 6FQ7 in the *same *circuit and never had any problems.
  
*EDIT:same*
 I never tried them in my LD.


----------



## chiman

Hi, one of my 6HM5 tubes is generating a buzzing, I swapped them over to see if it was the tube.
  
 If I touch it it stops for a second or two, anyway to fix it? It wasn't doing this until last night, it's the tube that flashes up if that helps?
  
 Thanks.


----------



## gibosi

chiman said:


> Hi, one of my 6HM5 tubes is generating a buzzing, I swapped them over to see if it was the tube.
> 
> If I touch it it stops for a second or two, anyway to fix it? It wasn't doing this until last night, it's the tube that flashes up if that helps?


 
  
 There might be some tiny pieces of debris causing the problem, and if so, flicking the tube with your finger might dislodge this material. But if that doesn't work, then it is likely that the tube is simply bad and you might want to contact the vendor to ask for a replacement. Good luck!


----------



## TrollDragon

Possibly try cleaning the pins as well.


----------



## kvtaco17

anyone consider rolling the Psvane UK-6SN7?


----------



## gibosi

kvtaco17 said:


> anyone consider rolling the Psvane UK-6SN7?


 
  
 I would definitely like to try one of these, but they haven't gotten much attention, much less love, in the 6SN7 Addict's thread, and consequently I have no idea if these tubes are really worth $100 each. Until I can find out more, I am simply unwilling to spend that much for a tube that may be no better than a nice $25 Sylvania 6SN7GT.
  
 But of course, it would be great if someone could get their hands on one of these and compare it to the "antiques" most of us are listening to.


----------



## kvtaco17

gibosi said:


> I would definitely like to try one of these, but they haven't gotten much attention, much less love, in the 6SN7 Addict's thread, and consequently I have no idea if these tubes are really worth $100 each. Until I can find out more, I am simply unwilling to spend that much for a tube that may be no better than a nice $25 Sylvania 6SN7GT.
> 
> But of course, it would be great if someone could get their hands on one of these and compare it to the "antiques" most of us are listening to.


 
  
 I agree about the cost... I'm currently burning a very noisy Sylvania 6SN7GTB in... its getting better... so far very musical, lush, with good extension and separation... DELICIOUS!
  
 Maybe someone here will be willing to test one lol (I'll probably get around to it when things calm down here)


----------



## gibosi

The tube I really want to try is the Mullard ECC32, but as one tube typically sells for $200 and more, I will need to win the lottery or get incredibly lucky for that to happen. lol


----------



## kvtaco17

Or save a few dollars here and there... Skimp on a meal couple times a week (cereal for dinner maybe?)


----------



## Artsi

Here is an example what kind of driver tubes i am using with my DIY amp, that uses 6N6P powertubes.
http://www.head-fi.org/t/698282/my-diy-headphone-tube-amps#post_10255710
  
 I think that RCA 6AS7G is going to stay many hours on this amp.


----------



## gibosi

I received a 1943 RCA 1633 this morning. The 1633 is a 25V version of a 6SN7 designed for use in aircraft in the 1940s. At $7.49 shipped, I figured it was a cheap way to try a 25V tube in my LD. And going by memory, it has the same delicious sound as my 1945 RCA gray-glass 6SN7GT.
  
 Oh, even though my AC adapter is rated for 24VDC, it is actually putting out 33VDC, so fortunately, I didn't have to purchase another adapter in order to run 25V tubes.


----------



## TrollDragon

Wow has this thread ever slowed down...

Everyone must have found some great tubes! I miss the good ole days of just switching from B7G's to B9A's so much excitement and activity in the thread.

Crickets...


----------



## dxanex

trolldragon said:


> Wow has this thread ever slowed down...
> 
> Everyone must have found some great tubes! I miss the good ole days of just switching from B7G's to B9A's so much excitement and activity in the thread.
> 
> Crickets...


 

 I've noticed that too. Although lately all my tube rolling has been going on with my Bottlehead Crack!


----------



## kvtaco17

I'm awaiting a bunch of tubes to review...


----------



## MIKELAP

trolldragon said:


> Wow has this thread ever slowed down...
> 
> Everyone must have found some great tubes! I miss the good ole days of just switching from B7G's to B9A's so much excitement and activity in the thread.
> 
> Crickets...


 
 http://www.youtube.com/watch?v=pShuE09VsjI


----------



## mordy

Probably some truth that people have found some great tubes and are busy listening to them. In addition, AFB who is one of the main contributors is abroad - I think he said Japan, and we have not heard from him in a while.
  
 Another thing that surprises me are that a number of people participate regularly and suddenly disappear. Perhaps they switched to a different type of amp or gave up on tubes - who knows?
  
 Acapella 11 - we miss you.
  
 SonySlave - what's up?
  
 inphu510n: any good deals on tubes?
  
 Hypnos1 -  what's going on?
  
 John57 - did u ever get to clean up your desk?
  
 And the mysterious (and ambitious) thread starter - Dept_of_Alchemy: What do you think about where we are now? No more Pentodes, Triodes, Triode/Diodes or Heptodes. Only glorious Dual Triodes.....
  
 Bitten by the vacuum tube bug:
  





  
 Oh no - another one!


----------



## TrollDragon

dxanex said:


> Although lately all my tube rolling has been going on with my Bottlehead Crack!


Nice!
That was one of my first choices, after the Speedball upgrade and Shipping / Duty to Canada it overshot the budget by quite a bit... The Bottlehead didn't have any WAF either...


----------



## TrollDragon

mikelap said:


> http://www.youtube.com/watch?v=pShuE09VsjI


 
 Ahhhhhh... that's enough to make my drive forks into my ears!


----------



## CollectoR13

Hello guys, as the thread kind of slowed down, i would ask for help on my new project. 
What i planned was an adapter for my ld mkiii that allows me to use 6sn7 as power tube and c3g as driver tube. 
I did never build any adapter, no experience. 
Do you think it is possible for an soldering noob like me to build this adapter? 
I highly doubt that i could solder the pins in the right layout... 

Another question, what tube adapters or...... do i need to buy to connect to the sockets of the mkiii in driver and power section? 

Thank you guys! 
Great thread!


----------



## gibosi

collector13 said:


> Hello guys, as the thread kind of slowed down, i would ask for help on my new project.
> What i planned was an adapter for my ld mkiii that allows me to use 6sn7 as power tube and c3g as driver tube.
> I did never build any adapter, no experience.
> Do you think it is possible for an soldering noob like me to build this adapter?
> ...


 
  
 To use 6SN7 as power tubes, you can purchase a ready-made adapter:
  
 http://www.ebay.com/itm/1pc-convert-tube-socket-6CG7-to-6SN7-/221065463320?pt=US_Amplifier_Parts_Components&hash=item3378874618
  
 Or more simply, you can use 6CG7 and 6FQ7 tubes, which are plug and play. However, you might find that your current power tubes are better....
  
 I have never seen a ready-made C3g to 6AK5 adapter, and making one is not trivial. The C3g has an 8-pin base and the 6AK5 has a 7-pin base, so you will have to figure out how to make that translation. To my knowledge, the only person who has done this is Hypnos1 so you might want to contact him.  
  
 But there is another option.... Like the C3g, the E80CC is a very low distortion tube. But in fact, when you strap the C3g as a triode, the distortion increases to a level comparable to a 6SN7. The E80CC, being a dual triode, doesn't need to be strapped and as a result, has lower distortion than a strapped C3g. Further, using a E80CC in our Little Dots is easier. All you need is a 9-pin socket and an external heater power supply, similar to a 6SN7.
  
 Anyway, whatever you decide, good luck and have fun!


----------



## mab1376

hypnos1 said:


> Audiofanboy.
> 
> Yep, you certainly were right to throw C3gs into the mix, after gibosi's related findings. My heartfelt thanks go to you both; Yamamoto, and JAC Music for pushing me in that direction. Even straight out of the box they were amazing, and now with a good few hours on them I still cannot believe what they have done for this modest not-so-little amp (ie the MKIV SE).
> While I am giving thanks, I for one would also like to say _grazie_ to the founder of this thread - Dept of Alchemy - and Acapella 11, who contributed so much to this thread and is sorely missed (where are you now?!). I would have loved to hear their views on what has been achieved these past months. Thanks also to all the other regulars, who have made this thread such an education AND joy (not to mention the "tube-roller widow" indoors!!)...
> ...


 
  
 This is the c3g pinout post


----------



## gibosi

hypnos1 said:


> Mordy, and anyone else interested, here is the pin layout for said C3g :
> 
> C3g               6AK5(et al)
> 
> ...


 
  
 I can see a very crude, but easy way to do this with two 8-pin breadboard sockets and two Vector 7-pin test sockets:
  
 Purchase two 8-pin breadboard sockets for the C3gs. In each socket, tie pins 2 and 5 and 7 together, which straps Grid 3 to the cathode. And then tie pins 3 and 4 together, which straps Grid 2 to the anode. And then route pins 3 (anode), 5 (cathode) and 6 (grid) in each of these sockets to the corresponding pins in the Vectors plugged into your LD.
  
 Edit: And don't forget about the heaters! 
 Edit2: It is not necessary to tie pins 5 and 7 together, as they are tied together inside the tube.... 
 Edit3: Correction: 8-pin loctal breadboard sockets
 Edit4: More corrections....


----------



## hypnos1

gibosi said:


> I can see a very crude, but easy way to do this with two 8-pin breadboard sockets and two Vector 7-pin test sockets:
> 
> Purchase two 8-pin breadboard sockets for the C3gs. In each socket, tie pins 2 and 5 and 7 together, which straps Grid 3 to the cathode. And then tie pins 3 and 4 together, which straps Grid 2 to the anode. And then route pins 3 (anode), 5 (cathode) and 6 (grid) in each of these sockets to the corresponding pins in the Vectors plugged into your LD.
> 
> ...


 
  
 Hi gibosi, mab and collectoR13.
  
 Many thanks g and m for referring cR13 to my previous posts, and sorry cR13 for not responding sooner...had spent 40mins this afternoon composing a long post, just for it to be trashed when I tried to add a link to a video on youtube, which I thought y'all might find interesting....I was not best amused, to say the least! So I shall try to see how I'm supposed to do it _correctly_ this time...
  
 Gibosi : lots more 'bits 'n pieces' but yes, safer for someone not confident in adapter-making land...such a shame.
 Was interested by your instruction to tie C3g's pins 3 and 4 together. I routed #4 to LD's #6...can you enlighten me - is it to do with how the LD socket itself is wired? I have had no adverse effects whatsoever....And yes, it appears from the tube data that pins 5 & 7 _are_ linked internally.
  
 cR13 -  My advice  would be - if you already have said C3gs - to follow gibosi's idea first, _then_ practice having a go at putting together some adapters yourself using a 'dummy' 8-pin, bending some solid 1 or 1.2 mm wire through a drilled disc (not metal, of course!!) that corresponds to the base of a 7-pin tube, and routed as per the pin-layout posts - but you MUST be sure of the pin numbering, both at the C3g and the disc...just remember that when viewing the pins from below, they run with #1 to the left, then clockwise. The solid wire then becomes the lower pins, of course, which has got to be far better than using a cut-off base from an old tube IMHO. Then you would need to seal and enclose the innards, however you wish. Needless to say, you MUST also make sure that no _bare_ wire can possibly touch another (or anything else metal)...or...BOOM!
 I must admit this is a tall order for a noob - but then so was I before I joined this thread. Only through reading the many posts of these past months, with the invaluable advice/knowledge freely given by so many great guys (no gals?!), plus practice (not to mention a wee bit o' courage/fright?!) have I managed to make a _little_ progress in this field. But if you are still not confident in such a venture, you would be wise not to go this route...Whatever, good luck with anything you try...


----------



## CollectoR13

Thank you very much guys! 
I would like to follow the way gibosi mentioned with c3g... 
But what kind of adapter should I buy to plug into the ef95 sockets? 
And i would like to keep it as simple as possible, i want a clean look like artsi achieved with his adapter.. 


And the readymade 6sn7 adapters are unfortunatly not shipping to germany... (and quite expensive lol) 


So my main problem is, i dont know which parts to use for what and how i could put them into a clean case..


----------



## CollectoR13

Thanks hypnos, you typed faster than i lol. 
I think i try what you said. 

Now on to the 6sn7, anyone got another readymade adapter, i did not find any?


----------



## i luvmusic 2

Hi, I just received my 6SN7 tube and i would like to know if i need to modify the adapter for 6SL7 or adjust the voltage on my external Power supply?I'am currently running 6SL7 with externel PS(driver Tube).


----------



## hypnos1

mordy said:


> Probably some truth that people have found some great tubes and are busy listening to them. In addition, AFB who is one of the main contributors is abroad - I think he said Japan, and we have not heard from him in a while.
> 
> Another thing that surprises me are that a number of people participate regularly and suddenly disappear. Perhaps they switched to a different type of amp or gave up on tubes - who knows?
> 
> ...


 
  
 WOW mordy, LOVE those bugs - they look how I feel after many hours of analysing/evaluating/comparing etc. etc. Not to mention frustrating indecision! Are we all certifiable, or what?!
  Addiction has a fascinating array of elements and emotions...and would we have it any other way? I think NOT!
  
 Yes, I have been quiet. And yes, it's because I continue to be blown away - still - by my C3gs, in a way I have never encountered before. I could swear the LD (MKIV SE at least) was _made_ for these beauties - which is rather surprising, as in my search to gain more info on said tubes it appears that even aficionados have had problems getting the best out of them, in their high-end set-ups. And yet this humble machine hasn't encountered the slightest hiccough, even after many 15+ hour sessions. On the contrary, they have continued to get better and better.
 I suspect they have been helped by my minimising connections from the tube pins to LD - ie mechanically attached _and_ soldered 1.2mm silver wire (soft-annealed), basically acting as extended pins. A bit fiddly but, I believe, well worth it...
  
 And so, as I believe I would have to spend BIG bucks for only little gain (which I am loathe to do in _any_ area of life), I think this is where I shall be happy for a very long time.
  
 Anyway folks, in my search I came across a mind-blowing video of a tube set-up like no other I have come across, and which you might find interesting/amusing. It is not a head-amp, but as a part of the 'beast' he has used C3gs, which must say something for them, methinks...
  
 http://www.youtube.com/watch?v=dZ0N1g-kH1M
  
  
 Oh dear, wrong again - still haven't managed a clickable link, but at least I've managed an address! Will try again - but AFTER I have posted this!!
  
 Edit. Well what d'ya know - the link IS clickable when submitted...yipeee!


----------



## mordy

Hi I luvmusic2,
  
 The 6SL7 and the 6SN7 use the same adapter, but the 6SN7 draws more power, and you need and external power supply. The voltage is the same for both the SL and SN tubes, 6.3V.
  
 So, in your case, it's just plug and play - you do not need to make any changes since you already are using the external PS.
  
 IMHO, the 6SN7 is a better tube for the LD amps. Whatever the 6SL7 has, the 6SN7 has more of ...
  
 Good luck listening!


----------



## i luvmusic 2

mordy said:


> The 6SL7 and the 6SN7 use the same adapter, but the 6SN7 draws more power, and you need and external power supply. The voltage is the same for both the SL and SN tubes, 6.3V.
> 
> So, in your case, it's just plug and play - you do not need to make any changes since you already are using the external PS.
> 
> ...


 
 THANK YOU! Now it's time for me to switch the tube.


----------



## i luvmusic 2

Just a reminder to anyone using Vector adapter becareful when handling it while it's installed on your amp.I thouht i turned off my amp but it turned out i forgot to do so, when i grab the adapter don't know which part i touch and i got shock not a good experienced.Dumb me....


----------



## gibosi

hypnos1 said:


> Gibosi : lots more 'bits 'n pieces' but yes, safer for someone not confident in adapter-making land...such a shame.
> Was interested by your instruction to tie C3g's pins 3 and 4 together. I routed #4 to LD's #6...can you enlighten me - is it to do with how the LD socket itself is wired? I have had no adverse effects whatsoever....And yes, it appears from the tube data that pins 5 & 7 _are_ linked internally.


 
  
 Yes, it amounts to the same thing. Per my instructions, Grid 2 (pin 4) is strapped to the anode (pin 3) in the socket. Routing Grid 2 (pin 4) directly to LD #6 takes advantage of the fact LD straps LD #6 to LD #5 (anode) internally by default.


----------



## gibosi

collector13 said:


> Thank you very much guys!
> I would like to follow the way gibosi mentioned with c3g...
> But what kind of adapter should I buy to plug into the ef95 sockets?
> And i would like to keep it as simple as possible, i want a clean look like artsi achieved with his adapter..
> ...


 
  
 Unfortunately, my solution trades off clean and neat for easy and ugly. But as Hypnos1 suggests, once you have everything working to your satisfaction using "Easy and Ugly," then your next task will be to figure out how to make two "Clean and Neat" adapters, with C3g on top and 6AK5 on the bottom. And as I have absolutely no experience with "Clean and Neat" adapters or C3gs, I cannot help you....
  
 Parts for "Easy and Ugly":
  
 For the C3gs.
  
 You need two 8-pin loctal breadboard sockets like this:
  
 http://www.ebay.com/itm/8-pin-loctal-breadboard-prototype-tube-socket-for-DIY-experimenting-NOT-OCTAL-/151163424139?pt=Vintage_Electronics_R2&hash=item23320acd8b
  
 To connect the C3g to your Little Dot, you need two 7-pin Vector test sockets like this:
  
 http://www.radiodaze.com/product/15450.aspx
  
 Since you are in Germany, you may have to find other sources for these items, but the pictures should help you recognize what you are looking for.
  
 Cheers,
  
 Edit: Changed to reflect Oskari's correction.


----------



## Oskari

gibosi said:


> For the C3gs.
> 
> If you leave the metal casing on, you need two 8-pin loctal breadboard sockets like this:
> 
> ...


 
  
 Why wouldn't the socket above work?
  


> http://www.ebay.com/itm/eu-8-Pin-Tube-sockets-Experiment-boards-x1-for-tube-project-diy-prototype-test-t-/290965746041?pt=Vintage_Electronics_R2&hash=item43bee8f179


 
  
 Nope. That's for rimlock tubes.


----------



## gibosi

oskari said:


> Why wouldn't the socket above work?
> 
> 
> Nope. That's for rimlock tubes.


 
  
 Ah, so the loctal socket works with or without the case.... This makes things a bit simpler.  And as I have no experience with tubes like the C3g, I need others to correct me when I go astray.... Thanks


----------



## CollectoR13

Thank you guys, i will start searching for parts. 
But what about the 6sn7?
There should not be a high risk to use them as power tubes, since the stock ones draw similar current, right? 
Does anybody know another readymade adapter?


----------



## gibosi

collector13 said:


> Thank you guys, i will start searching for parts.
> But what about the 6sn7?
> There should not be a high risk to use them as power tubes, since the stock ones draw similar current, right?
> Does anybody know another readymade adapter?


 
  
 You will need to search for an adapter with 6SN7 on top and 6CG7 on the bottom.
  
 It should work fine.... However, since my LD 1+ uses an op amp instead of power tubes, I just do not know....


----------



## CollectoR13

Ok... 
And if I would try the same method like for the c3g, like hypnos adviced, means taking some copper wire of 1mm and manually wiring from every socket to a top socket? 
How should I wire from 6n30 to 6sn7?


----------



## gibosi

Yesterday a small package appeared in my mailbox with a 1952 Brimar 13D1 / CV423. This is a British mil-spec version of the 25SN7 (25V version of the 6SN7), specifically designed for use in aircraft and other high-reliability applications. Interestingly, but probably of no consequence, it has two D-getters. I spent a couple hours with it last night and found it to be a very good sounding tube, very enjoyable.
  
 Also in this series, there is the 13D2, which is essentially identical to a 6SN7.
  
 And there is a 9-pin miniature 13D3 (premium version 6158 / CV4068). This appears to be very similar to the 6CG7 / 6FQ7, except for the pin-out. The 13D3 has the same pin-out as a 12AU7, and therefore, can be configured to run with either 6.3 or 12.6 heaters. However, if configured to run with 6.3V heaters, it draws 600ma, so either way, an external heater PS would still be necessary to use these in our Little Dots.
  
13D1,13D2,13D3 Datasheet


----------



## gibosi

collector13 said:


> Ok...
> And if I would try the same method like for the c3g, like hypnos adviced, means taking some copper wire of 1mm and manually wiring from every socket to a top socket?
> How should I wire from 6n30 to 6sn7?


 
  
 The 6N30 has the same pin-out as the 6CG7, and therefore, my previous suggestion still holds: 
  
 You will need to search for an adapter with 6SN7 on top and 6CG7 or 6DJ8 or 6N1 on the bottom. All these tubes, 6N30, 6N1, 6CG7 6DJ8 have the same pin-out. This is a common adapter and you should have no trouble finding one. I use one of these adapters to run 6SN7 tubes in my 9-pin breadboard socket.


----------



## hypnos1

gibosi said:


> Unfortunately, I suspect that many of us, myself included, are a bit daunted by the task of building a proper set of adapters, plus the cost of a pair of C3gs. Perhaps you should consider starting a cottage industry? Perhaps "C3gLD" would be a good name? lol
> 
> For sure, I can't help but wonder how these compare to the E80CC....


 
  
 gibosi...I think your statement - 'Perhaps "C3gLD" would be a good name?' - is actually FAR more apt than you may have realised...let me explain :
  
 This afternoon, having done some research on 'pentode v triode', several lightbulbs have suddenly burst into the ol' grey matter.
 With contrasting opinions regarding triode-strapped pentodes, it would appear to all come down (fairly obviously, really...) to how the amp is optimised - including their relative merits/deficiencies compared to 'true' triodes. As the LD was _designed_ to use pentodes in this way (and _not_ triodes per se), this would explain why the C3g has been accepted so gleefully - I believe it to be the proverbial 'prodigal son'...in other words, the tube that _should_ have been in the LD - at least the later, more expensive, models - from the off. This would have taken them to a level far beyond the competition, I am sure. AND saved us all an immense journey in time, effort and money (although it _has_ been a wonderful journey in many respects).
 So, in reality, it seems we may have been going round in circles to some degree - we HAVE been making _incremental_ improvements, but mostly because the WRONG pentodes were chosen in the first place!!! Obviously things are built to a price point, but I am sure that with bulk-buying and NO need for any (material) alteration to the unit, the extra price premium could have been minimal...
 Ah well, I suppose this is easy to say with hindsight - but I still feel that perhaps further research at the outset _may_ have had the LD team hit on a winner to beat all comers, anywhere near the price level.
  
 Rant over... At least I can now enjoy my "LDMKIV C3g"
  
 Cheers everyone.


----------



## mordy

Hi,
  
 What is the difference between a 6SN7 tube and a
  
 6BX7 and a 31BX7 tube?
  
 6DN7 tube?
  
 6BL7 tube?
  
 Can these tubes be used in the LD with an external PS?


----------



## gibosi

hypnos1 said:


> This afternoon, having done some research on 'pentode v triode', several lightbulbs have suddenly burst into the ol' grey matter.
> With contrasting opinions regarding triode-strapped pentodes, it would appear to all come down (fairly obviously, really...) to how the amp is optimised - including their relative merits/deficiencies compared to 'true' triodes. As the LD was _designed_ to use pentodes in this way (and _not_ triodes per se), this would explain why the C3g has been accepted so gleefully - I believe it to be the proverbial 'prodigal son'...in other words, the tube that _should_ have been in the LD - at least the later, more expensive, models - from the off. This would have taken them to a level far beyond the competition, I am sure. AND saved us all an immense journey in time, effort and money (although it _has_ been a wonderful journey in many respects).
> So, in reality, it seems we may have been going round in circles to some degree - we HAVE been making _incremental_ improvements, but mostly because the WRONG pentodes were chosen in the first place!!! Obviously things are built to a price point, but I am sure that with bulk-buying and NO need for any (material) alteration to the unit, the extra price premium could have been minimal...
> Ah well, I suppose this is easy to say with hindsight - but I still feel that perhaps further research at the outset _may_ have had the LD team hit on a winner to beat all comers, anywhere near the price level.
> ...


 
  
 Perhaps... But the major problem with strapping pentodes into triodes is that linearity is typically lost. And this is the feature that makes the C3g so attractive. Unlike most pentodes, a strapped C3g retains its linearity. It is just as linear used as a triode as it is a pentode. And in fact, the Cg3, triode strapped, is as linear as a "real very good triode" (http://www.jacmusic.com/techcorner/ARTICLES/English-neu/Portraits/C3g/C3g-C3m-info.html). So I am inclined to think that, electrically, the difference between using a "real very good triode" and a C3g in our LDs is negligible.
  
 Regarding strapping the C3g, we have decided to use one of two common configurations, Grid 3 to the cathode and Grid 2 to the anode. However, another common configuration straps both G2 and G3 to the anode, as the EF91/92. You might remember that with many pentodes and heptodes, selecting one or the other of these strappings significantly changed the sound. Does anyone know if there is a "recommended" triode strapping configuration for the C3g? Absent that information, one of the advantages of my "easy and ugly" configuration is that it would be very simple to try both of these strappings to see if there is a difference....
  
 Anyway.......  just some stuff that have been going around in my head.....


----------



## gibosi

mordy said:


> Hi,
> 
> What is the difference between a 6SN7 tube and a
> 
> ...


 
  
 These might be OK, but they all draw some serious heater current: The 6BX7 / 6BL7 / 31BX7 heaters draw 1.5 amps and the 6DN7 heaters draw .9 amps. Personally, I think these are more like power tubes than drivers.....


----------



## mab1376

hypnos1 said:


> gibosi...I think your statement - 'Perhaps "C3gLD" would be a good name?' - is actually FAR more apt than you may have realised...let me explain :
> 
> This afternoon, having done some research on 'pentode v triode', several lightbulbs have suddenly burst into the ol' grey matter.
> With contrasting opinions regarding triode-strapped pentodes, it would appear to all come down (fairly obviously, really...) to how the amp is optimised - including their relative merits/deficiencies compared to 'true' triodes. As the LD was _designed_ to use pentodes in this way (and _not_ triodes per se), this would explain why the C3g has been accepted so gleefully - I believe it to be the proverbial 'prodigal son'...in other words, the tube that _should_ have been in the LD - at least the later, more expensive, models - from the off. This would have taken them to a level far beyond the competition, I am sure. AND saved us all an immense journey in time, effort and money (although it _has_ been a wonderful journey in many respects).
> ...


 
  
 Did you test the cg3 vs the cg3s?
  
 also what is the price you paid if you don't mind me asking, they don't seem to have a price posted anywhere.
  
 -edit-
  
 i found the price list, looks like $40.86 each form JAC music or $66.01 each for the c3gs for the Siemens, Telefunken are absolutely ridiculous pricing!
  
 (That's after a quick currency conversion from the euro using google, based on their "Export" price)
  
 http://www.jacmusic.com/html/order/jacmusic-pricelist.PDF


----------



## rosgr63

gibosi said:


> These might be OK, but they all draw some serious heater current: The 6BX7 / 6BL7 / 31BX7 heaters draw 1.5 amps and the 6DN7 heaters draw .9 amps. Personally, I think these are more like power tubes than drivers.....


 
  
 I have an amp that uses six 6BL7s as output tubes.
 Wonderful low end.


----------



## Oskari

gibosi said:


> Ah, so the loctal socket works with or without the case.... This makes things a bit simpler.  And as I have no experience with tubes like the C3g, I need others to correct me when I go astray.... Thanks


 
  
 It should also be noted that removing the bottom part with the spigot is a bad idea. With no spigot, the tube can be inserted eight different ways, only one of which is correct. The spigot also protects the evacuation tip.


----------



## hypnos1

gibosi said:


> Perhaps... But the major problem with strapping pentodes into triodes is that linearity is typically lost. And this is the feature that makes the C3g so attractive. Unlike most pentodes, a strapped C3g retains its linearity. It is just as linear used as a triode as it is a pentode. And in fact, the Cg3, triode strapped, is as linear as a "real very good triode" (http://www.jacmusic.com/techcorner/ARTICLES/English-neu/Portraits/C3g/C3g-C3m-info.html). So I am inclined to think that, electrically, the difference between using a "real very good triode" and a C3g in our LDs is negligible.
> 
> Regarding strapping the C3g, we have decided to use one of two common configurations, Grid 3 to the cathode and Grid 2 to the anode. However, another common configuration straps both G2 and G3 to the anode, as the EF91/92. You might remember that with many pentodes and heptodes, selecting one or the other of these strappings significantly changed the sound. Does anyone know if there is a "recommended" triode strapping configuration for the C3g? Absent that information, one of the advantages of my "easy and ugly" configuration is that it would be very simple to try both of these strappings to see if there is a difference....
> 
> Anyway.......  just some stuff that have been going around in my head.....


 
  
 Yes gibosi, the C3g is one VERY special pentode!  And certainly streets ahead of any triode I personally have tried...
  
 As to trying both G2 and G3 tied to the anode, I may just be able to give it a go - in my first adapters I ran the strap wire _externally_, so I can instead link down to the anode at the socket - promise me all will be well!! Actually, I am only prepared to give it a try because I was fortunate enough to get a pair of C3gSs for no more than I paid for plain C3gs - couldn't resist! So it's back to adapter construction...at least I feel much more confident with that now...
 Will keep you informed...


----------



## hypnos1

mab1376 said:


> Did you test the cg3 vs the cg3s?
> 
> also what is the price you paid if you don't mind me asking, they don't seem to have a price posted anywhere.
> 
> ...


 
  
 As per my previous post, I have been lucky enough to get a pair of Siemens C3gSs - for under $70 the PAIR. So I look forward to comparing them with the 'plain' ones. But as they look such well-made tubes, I doubt there will be much difference... the main reason anyway was to have some in reserve - I do not want to take_ any_ chances with these babies!
 JAC are pricey - I'm sure more tubes will trickle onto ebay. And as for the Telefunkens...NO WAY!!


----------



## hypnos1

oskari said:


> It should also be noted that removing the bottom part with the spigot is a bad idea. With no spigot, the tube can be inserted eight different ways, only one of which is correct. The spigot also protects the evacuation tip.


 

 Yes Oskari - GREAT care is needed, and certainly not for the faint-hearted! There is in fact a slightly raised 'marker' on the underside of the glass, which indicates the 1-8 demarcation (but you need fairly good eyes!). The protruding tip can also induce mild panic, so all in all it is far safer to leave the bottom on. In my case, I wanted to use minimal space for neatness in the adapter, and as I was using bare silver wire didn't want that metal spigot in the way! Needless to say, I took things VERY carefully and VERY slowly, checking things twice and thrice. So it can be done, but...
  
 Thanks for pointing out possible pitfalls to anyone interested.


----------



## Oskari

hypnos1 said:


> There is in fact a slightly raised 'marker' on the underside of the glass, which indicates the 1-8 demarcation (but you need fairly good eyes!).


 
  
 It's quite a brilliant design that 'marker' being a _spigot_ in itself for the _socket_ that is the bottom metal part of the tube.


----------



## gibosi

oskari said:


> It should also be noted that removing the bottom part with the spigot is a bad idea. With no spigot, the tube can be inserted eight different ways, only one of which is correct. The spigot also protects the evacuation tip.


 
  
 If... I get a pair of these, I would like to remove the top metal cap, but is it possible to easily do so without disturbing the metal base?


----------



## gibosi

hypnos1 said:


> As to trying both G2 and G3 tied to the anode, I may just be able to give it a go - in my first adapters I ran the strap wire _externally_, so I can instead link down to the anode at the socket - promise me all will be well!! Actually, I am only prepared to give it a try because I was fortunate enough to get a pair of C3gSs for no more than I paid for plain C3gs - couldn't resist! So it's back to adapter construction...at least I feel much more confident with that now...
> Will keep you informed...


 
  
 Well, I have tied G2 and G3 to the anode on lots of pentodes with absolutely no problems, so it SHOULD be fine. lol 
  
 The published curves for the C3g strapped as a triode were generated using one or the other of these strappings, so one would think that somewhere there is some fine print indicating precisely how this was done. My gut feeling is that it does make a difference and they were most likely strapped identically to yours, Grid 3 to the cathode and Grid 2 to the anode, as this seems to be the most common strapping. On the other hand, it should be an interesting exercise to compare the two strappings to see if there is a difference.


----------



## mab1376

Hypnos1,
  
 Does this look right for the c3g to 6ak5 adapter pinout, i made it one to one to make it more readable.
  

cg3 6ak5   1 32 73 54 65 26 17 78 4
  
 Also does the c3g use the same socket at the 6SL7 (octal?)


----------



## gibosi

mab1376 said:


> Hypnos1,
> 
> Does this look right for the c3g to 6ak5 adapter pinout, i made it one to one to make it more readable.
> 
> ...


 
  
 Yes, if you are going to make a "clean and neat" adapter similar to that of Hypnos1, this pin translation is the way to go. But no, an octal socket will not work. You want to use a LOCTAL socket.


----------



## mab1376

gibosi said:


> Yes, if you are going to make a "clean and neat" adapter similar to that of Hypnos1, this pin translation is the way to go. But no, an octal socket will not work. You want to use a LOCTAL socket.


 
 OK thanks.
  
 Also i was looking for a PSU while my regulator board is on its way, i found one that outputs 12v at 500ma, is that sufficient or should i find something that outputs around 1amp?


----------



## gibosi

mab1376 said:


> OK thanks.
> 
> Also i was looking for a PSU while my regulator board is on its way, i found one that outputs 12v at 500ma, is that sufficient or should i find something that outputs around 1amp?


 
  
 My recommendation is at least 15V, as this gives you the option of running 12V tubes.
  
 Using the adapter you found, Power (watts) = Volts X Amps. So 12 x .5 = 6 watts. So to determine that available amps for 6.3 tubes:  6 watts / 6.3V = .95 amp, which is quite adequate. But again, I would recommend at least 15V. Mine puts out 30V which allows me to run 25V tubes. 
  
 However, here's is a nice 16V adapter:
  
 http://www.ebay.com/itm/IBM-AC-Adapter-08K8204-100-240V-1-5A-0-9A-16V-4-5A-/141192619642?pt=LH_DefaultDomain_0&hash=item20dfbc667a


----------



## samtheman

Hi Everyone,
  
 I've haven't viewed this thread for a very long time (the most recent and best tube I have for my MKIII is a pair of Yugo 6hm5 tubes) and I've spent the last few weeks trying to play catch-up. Not being the most technically gifted hamster on the wheel, I must confess to being at least partly baffled by recent developments. Money is very tight at the moment and I'm thinking of trying one of the new Octals and making an adapter. With this in mind I have a few questions I'm hoping someone might be willing to answer:
  
 1. For an adapter, can I make a cheap one using metal pins from here:
 http://www.ebay.com/itm/35pcs-IN-8-IN-12-IN-18-NIXIE-VFD-TUBE-PINS-VALVE-SOCKET-TO-PCB-UNIVERSAL-PIN-/121254898319?pt=Vintage_Electronics_R2&hash=item1c3b5aea8f
  
  
 and then wiring them to a cheap Octal socket such as:
 http://www.ebay.ie/itm/8-Pin-Gilard-Bakelite-Octal-Audio-Amplifier-Tube-Socket-/270649677461?pt=UK_Sound_Vision_Other&hash=item3f03fa5695
  
 2. I am willing to do a little soldering and assuming I have made such an adapter correctly (I'd be very grateful if someone could point me in the direction of a wiring diagram?) can I bypass the need for an external power supply and use an 6sn7 tube and still see a marked upgrade from the Yugo 6hm5 tubes? If that is correct, what would be a good quality cheap 6sn7 tube be? Is this a good one:
 http://www.ebay.com/itm/Tung-Sol-6SN7-GT-Tall-black-Plates-bottom-getter-Tested-/141170484884?pt=UK_Sound_Vision_Valves_Vacuum_Tubes&hash=item20de6aa694
  
 I will be feeding my MKII with a  LD DACII and for headphones using a pair of Byerdynamic t90s. The cans are bright so I guess I'm looking to tame siblence while retaining clarity etc.
  
 Any help would be gratefully received as I'm trying to decide if I should stick or twist with regards to the 6hm5 tubes.
  
 Thank you


----------



## mab1376

gibosi said:


> My recommendation is at least 15V, as this gives you the option of running 12V tubes.
> 
> Using the adapter you found, Power (watts) = Volts X Amps. So 12 x .5 = 6 watts. So to determine that available amps for 6.3 tubes:  6 watts / 6.3V = .95 amp, which is quite adequate. But again, I would recommend at least 15V. Mine puts out 30V which allows me to run 25V tubes.
> 
> ...


 
  
 I have a Nintendo Wii adapter that outputs 12v at 3.7amp
  
 that wouldn't hurt the voltage regulator board would it?


----------



## gibosi

mab1376 said:


> I have a Nintendo Wii adapter that outputs 12v at 3.7amp
> 
> that wouldn't hurt the voltage regulator board would it?


 
  
 It wouldn't hurt it at all. The tube is going to draw only what it needs. So even though the adapter can deliver about 7 amps into 6.3V, a 6SN7, for example, is going to draw only 600 milliamps.
  
 Perhaps too far out of the box, but something to think about....  C3m tubes are easier to find than C3gs, probably because they have 20V heaters, instead of 6.3V. So you could purchase two 24V adapters, two voltage regulators and two C3ms....


----------



## gibosi

samtheman said:


> I've haven't viewed this thread for a very long time (the most recent and best tube I have for my MKIII is a pair of Yugo 6hm5 tubes) and I've spent the last few weeks trying to play catch-up. Not being the most technically gifted hamster on the wheel, I must confess to being at least partly baffled by recent developments. Money is very tight at the moment and I'm thinking of trying one of the new Octals and making an adapter. With this in mind I have a few questions I'm hoping someone might be willing to answer:
> 
> 1. For an adapter, can I make a cheap one using metal pins from here:
> http://www.ebay.com/itm/35pcs-IN-8-IN-12-IN-18-NIXIE-VFD-TUBE-PINS-VALVE-SOCKET-TO-PCB-UNIVERSAL-PIN-/121254898319?pt=Vintage_Electronics_R2&hash=item1c3b5aea8f
> ...


 
   
 If you just want metal pins, these might be better:
  
 http://www.ebay.com/itm/100pc-gold-plated-tube-pin-you-DIY-Tube-adapter-15-1mm-free-shipping-/200977094414?pt=US_Home_Audio_Amplifiers_Preamps&hash=item2ecb2b170e
  
 And you are going to need some kind of a base to hold the pins. Some have glued the pins into these:
  
 http://www.ebay.com/itm/British-Mullard-Tube-Pin-Straightners-NEW-OLD-STOCK-For-RCA-Telefunken-Brimar-/130832123892?pt=Vintage_Electronics_R2&hash=item1e7633c7f4
  
 Quote:
  


samtheman said:


> 2. I am willing to do a little soldering and assuming I have made such an adapter correctly (I'd be very grateful if someone could point me in the direction of a wiring diagram?) can I bypass the need for an external power supply and use an 6sn7 tube and still see a marked upgrade from the Yugo 6hm5 tubes? If that is correct, what would be a good quality cheap 6sn7 tube be? Is this a good one:
> http://www.ebay.com/itm/Tung-Sol-6SN7-GT-Tall-black-Plates-bottom-getter-Tested-/141170484884?pt=UK_Sound_Vision_Valves_Vacuum_Tubes&hash=item20de6aa694


 
  
 We believe that the Little Dot is designed to deliver no more than 500 milliamps per driver tube. The 6SN7 draws 600 milliamps. So I cannot in good conscience recommend that you skip the external power supply. By exceeding the design limits of the LD, you could very well be looking at smoke and fire....
  
 The Tung Sol you are looking at is a very nice tube and that is a great price. However, I have no experience with the Byerdynamic t90, so I can't say if it would be a good match


----------



## Oskari

gibosi said:


> If... I get a pair of these, I would like to remove the top metal cap, but is it possible to easily do so without disturbing the metal base?


 
  
 It isn't. See http://www.head-fi.org/t/600110/2359glenn-studio/2475#post_9329427


----------



## Oskari

gibosi said:


> The published curves for the C3g strapped as a triode were generated using one or the other of these strappings, so one would think that somewhere there is some fine print indicating precisely how this was done.


 
  
 It's right there in plain sight: "g2 an a, g3 an k". In German, obviously.
  

http://tubedata.tubes.se/sheets/190/c/C3g.pdf
http://tubedata.tubes.se/sheets/128/c/C3g.pdf


----------



## gibosi

oskari said:


> It isn't. See http://www.head-fi.org/t/600110/2359glenn-studio/2475#post_9329427


 
  
 Too much work for me! So if I get a pair of these, the metal caps will stay on. lol
  


oskari said:


> It's right there in plain sight: "g2 an a, g3 an k". In German, obviously.
> 
> 
> http://tubedata.tubes.se/sheets/190/c/C3g.pdf
> http://tubedata.tubes.se/sheets/128/c/C3g.pdf


 
  
 I see it now! Thanks! 
  
 So the strapping that Hypnos1 is using is the one we want to use.


----------



## hypnos1

oskari said:


> It isn't. See http://www.head-fi.org/t/600110/2359glenn-studio/2475#post_9329427


 
  
 Oskari - thanks for the post. Nice to see more coverage of the C3g...please also see below...
  


gibosi said:


> Too much work for me! So if I get a pair of these, the metal caps will stay on


 
  
 gibosi - can understand your reticence, but IF you do try these beauties (and anyone else for that matter), can I just point out that the method shown (ie using a flat-blade implement) is asking for trouble, and cannot understand its recommendation. FAR better (and easier) is to use a SMALL pair of pliers and prise away the outer cover from the metal base, as it (the crimped cover bottom) is of very soft metal and comes away nice and neatly with minimal effort. And with a bit of 'jiggling' the tube plus metal base pops out unharmed.
 The tubes unsheathed look SO much better than black canisters!
  
 I shall be taking a good few pics of my next adapter construction this weekend, so will post them ASAP...


----------



## samtheman

Thank you for the reply Gibosi
  
 I was mistaken and thought the 6sn7 tubes didn't need external power. Looks like it was the 6SL7GT I need. Are there any 6SL7GT tubes that would outclass the Yugo 6hm5 tubes?
  
 I'm going to have to give the whole idea a re-think as I really wanted to keep the price down as much as possible. I'll have a little dig around and see if I already have a power supply I could use.
  
 Thanks again!


----------



## hypnos1

gibosi said:


> Too much work for me! So if I get a pair of these, the metal caps will stay on. lol


 
  
 Re the strapping, I must admit I just cannot see how any other configuration could bring anything else to the table - everything is so wonderfully integrated. So it may be some good time before I play around with the status quo! Will therefore be linking C3gS pins 2 & 7 _inside_ the adapter tomorrow, for neatness sake...


----------



## mordy

Hi samtheman,
  
 I think that you will be happier with the 6SN7 tube than the 6SL7 tube. A voltage regulator is less than $5 and perhaps you have an old lap top PS sitting around - don't see any reason why you cant use one of those. The lap top PS is usually rated around 19V.
  
 Good luck!


----------



## samtheman

Thanks for the advice  I suspect you are right re the 6sn7 tube. I have a spare AC adapter rated as 5v 2000mA output - would that do the job?
 I'm also wondering if I could get away without the external power supply for a few hours to get a sense of the sound and then decide if it's worth getting the power supply and regulator?


----------



## Artsi

I heard you were talking about using 6SN7 as powertube. This was my totally hum and noise free adapter for octals, made some months ago.

 With 6SN7 you lose some maximum power to headphones, but otherwise they work like charm. Btw Ten 6SL7GT tube is not bad at all. Been burning it in for some time with my diy amps.


----------



## TrollDragon

samtheman said:


> Thanks for the advice  I suspect you are right re the 6sn7 tube. I have a spare AC adapter rated as 5v 2000mA output - would that do the job?
> I'm also wondering if I could get away without the external power supply for a few hours to get a sense of the sound and then decide if it's worth getting the power supply and regulator?


5V will not do it..

As to the other question...


----------



## gibosi

samtheman said:


> Thanks for the advice  I suspect you are right re the 6sn7 tube. I have a spare AC adapter rated as 5v 2000mA output - would that do the job?
> I'm also wondering if I could get away without the external power supply for a few hours to get a sense of the sound and then decide if it's worth getting the power supply and regulator?


 
  
 You need an AC adapter that puts out at least 10V at 400ma. I don't know that I have ever seen a 10V adapter, but 12V adapters are common.
  
 Rolling 6SN7s in your LD without an external PS is like rolling dice....  Your amp might be fine for a short time. Or it might not. I am sorry, but I am not willing to encourage you.
  
 And further, it may be that the Tung Sol you are looking at does not meet your fancy. But perhaps a Sylvania, RCA., Raytheon, Hitachi, or what have you, might be wonderful. I think you cannot judge an entire tube family from a sample size of one.
  
 To be very frank, if you cannot afford to try 6SN7s without cutting corners and taking risks, then I think you are much better off staying with your 6HM5s until you can afford to do it right.
  
 Cheers


----------



## samtheman

Thank you all for the suggestions and very sensible warnings. I will heed them and if I decide to build the adapter I will do it properly with an external power supply.
  
 Thanks again


----------



## samtheman

After some more digging around, I found an old hard drive power supply with these output ratings: 12Vdc -- 1.5A
  
 Am I right in assuming this will do the job? I've already ordered the other parts so am committed to making this work - and to doing it safety  
  
 Thanks


----------



## gibosi

samtheman said:


> After some more digging around, I found an old hard drive power supply with these output ratings: 12Vdc -- 1.5A
> 
> Am I right in assuming this will do the job? I've already ordered the other parts so am committed to making this work - and to doing it safety


 
  
 Yes, that adapter is more than adequate. Have fun!


----------



## Royan

Guys, do you know if Voshkod 6ZH1P-EV = 6J1P-EV? I'm looking for the real 6ZH1P-EV for a Little Dot MkIII.
  
 I found this matched pair on ebay at a very good price:
 http://www.ebay.com/itm/6ZH1P-EV-6J1P-EV-EF95-5AK5-Matched-pair-Mil-Tubes-TOP-/141184491953?pt=DE_TV_Video_Audio_Elektronenr%C3%B6hren_Valves&hash=item20df4061b1
  
 But the seller says "6ZH1P-EV / 6J1P-EV" and I read several post in these forums where people doubt if 6ZH1P-EV = 6J1P-EV, so I'm confused.
  
 There is another, pricier auction wich says 6ZH1P-EV only:
 http://www.ebay.com/itm/301050973465?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT
  
 I appreciate any information,
 Raul


----------



## Oskari

royan said:


> Guys, do you know if Voshkod 6ZH1P-EV = 6J1P-EV? I'm looking for the real 6ZH1P-EV for a Little Dot MkIII.


 
  

http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/225#post_7936925
http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/2385#post_9711481


----------



## MIKELAP

http://en.wikipedia.org/wiki/Russian_tube_designations


----------



## Royan

Many thanks!!


----------



## gibosi

royan said:


> Guys, do you know if Voshkod 6ZH1P-EV = 6J1P-EV? I'm looking for the real 6ZH1P-EV for a Little Dot MkIII.
> 
> I found this matched pair on ebay at a very good price:
> http://www.ebay.com/itm/6ZH1P-EV-6J1P-EV-EF95-5AK5-Matched-pair-Mil-Tubes-TOP-/141184491953?pt=DE_TV_Video_Audio_Elektronenr%C3%B6hren_Valves&hash=item20df4061b1
> ...


 
  
 Yes, they are the same. It just comes down to how the Russian cyrillic alphabet is translated into English. And to give you one more choice, I bought mine from this vendor:
  
 http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=130436695928&ssPageName=ADME:L:OC:US:3160


----------



## CollectoR13

Hello guys! 

Just wanted to say that I ordered 2 octal and 2 loctal sockets, a black case, silver plated copper wire and 2 sylvania 6sn7gt black plate, bottom d getter and also 2 siemens c3g-s, so I am ready to build my adpater in a couple weeks! 

What I need is some table or something showing me how to rewire the pins from 6n6p to 6sn7, do you have any clue where I could find this? 

Thanks in advance, looking forward for some tube adapter magic 

Edit:
Artsi, maybe you could help me, as you already built an adapter to use 6sn7 as power tube?


----------



## gibosi

collector13 said:


> What I need is some table or something showing me how to rewire the pins from 6n6p to 6sn7, do you have any clue where I could find this?


 
  
 This would be a good time for you to learn how to read data sheets:
  
 6N6P
  
 http://tubes.ru/techinfo/HiFiAudio/6n6poc.html
  
 6SN7
  
 http://www.radiostation.ru/tubes/6SN7.pdf
  
 The key is that the "basing diagram" or "lead diagram" is analogous to holding the tube upside down. That is, hold the tube in your hand, upside down and translate the pins from one tube to the other. However, you have to remember that you will insert the tube right side up. So when you diagram from one socket to the other, you will use the mirror image.
  
 Have fun.


----------



## mab1376

gibosi said:


> This would be a good time for you to learn how to read data sheets:
> 
> 6N6P
> 
> ...


 
 Can 6SN7 be used as power tube without any power supplies?


----------



## gibosi

mab1376 said:


> Can 6SN7 be used as power tube without any power supplies?


 
  
 Yes. 6SN7s draw a little less heater current than the standard LD power tubes, so absolutely no problem.


----------



## CollectoR13

Sorry for the stupid question, but is there any site explaining the letter abbreviations of tube diagrams? 
Did not find any... 
Or I am just not searching right...


----------



## gibosi

collector13 said:


> Sorry for the stupid question, but is there any site explaining the letter abbreviations of tube diagrams?
> Did not find any...
> Or I am just not searching right...


 
  
 I suspect you are stymied by the 6N6P basing diagram. Yes, the Russian abbreviations appear to be a bit different. Typically, a = plate, g = grid, k = cathode, s = shield and f = heater. Here are two 6CG7 datasheets, which has the same pin-out as the 6N6P, to help you figure it out:
  
 http://www.radiomuseum.org/tubes/tube_6cg7.html
  
 http://www.drtube.com/datasheets/6cg7-ge1956.pdf


----------



## mordy

Hi,
  
 Can somebody clarify to me if I could used an external power supply rated 2A (3A peak) to supply two separate tubes at the same time. The combined heater draw would be less than 2A for the two tubes.
  
 Next question: I have two bread boards, one set up for 6DJ8 tubes and the other for 12AX7/octal tubes w adapter. The heater connections are different for these two boards. Would there be any problem if I would connect my external PS to both boards with separate wires, but only use one board at a time? In other words, both boards would be connected to the PS, but only one tube would be plugged in at any given time. This way I would not have to switch wires when I change from one tube family to another.


----------



## gibosi

mordy said:


> Can somebody clarify to me if I could used an external power supply rated 2A (3A peak) to supply two separate tubes at the same time. The combined heater draw would be less than 2A for the two tubes.
> 
> Next question: I have two bread boards, one set up for 6DJ8 tubes and the other for 12AX7/octal tubes w adapter. The heater connections are different for these two boards. Would there be any problem if I would connect my external PS to both boards with separate wires, but only use one board at a time? In other words, both boards would be connected to the PS, but only one tube would be plugged in at any given time. This way I would not have to switch wires when I change from one tube family to another.


 
  
 Someone other than myself will have to weigh in on the first question. But my thinking is that this would be a parallel connection, and so if the output from the regulator is set to 12.6V, then I think you could supply two 6.3V tubes. But again, my working knowledge is insufficient to say for sure....
  
 And as long as you are using only one socket at a time, I can see no reason why you couldn't connect both sockets as you propose...  But here too, I hope someone else will weigh in....


----------



## TrollDragon

mordy said:


> Hi,
> 
> Can somebody clarify to me if I could used an external power supply rated 2A (3A peak) to supply two separate tubes at the same time. The combined heater draw would be less than 2A for the two tubes.
> 
> Next question: I have two bread boards, one set up for 6DJ8 tubes and the other for 12AX7/octal tubes w adapter. The heater connections are different for these two boards. Would there be any problem if I would connect my external PS to both boards with separate wires, but only use one board at a time? In other words, both boards would be connected to the PS, but only one tube would be plugged in at any given time. This way I would not have to switch wires when I change from one tube family to another.


 

 Hey mordy
  
 Here is a schematic of a tube amp that provides filament power to 5 tubes from the one 6.3V 3A transformer.

  
 The transformer T3 provides High Voltage and Heater power.
 They have on the 6.3V winding a Pilot Lamp PL1
 Filament power to the 6X4 Rectifier Tube
 Tube Filament V1 & V4 are 12AX7's in 6.3V mode using 4/5 & 9 as heater wires just like our adapters.
 Tube Filament V2 is a 12AT7 in 6.3V mode
 Tube Filament V3 is a 6AK5 native 6.3V filament.
  
 So with a 3A supply they are powering all these filaments in parallel...
  
 With your 2A supply you could power as many tubes as you want adding up the current draw of each tube. Don't forget that from cold, tubes will draw quite a bit more current than they rated at for a split second. If you are going to be powering 2 tubes that draw close to 2A, I would use at least a 3A supply to drive them. As they could draw close to 3 or 4 amps for a split second before warming up.
  
 Running a 2A rated supply at it's max output is usually not a good thing, the regulator that provides your 2A will wear out quite a bit sooner than if it was a 3A version. A 5A supply would be ideal with lots of headroom for whatever you wanted to try.


----------



## TrollDragon

gibosi said:


> And as long as you are using only one socket at a time, I can see no reason why you couldn't connect both sockets as you propose...  But here too, I hope someone else will weigh in....


 
 Running the wires in parallel will cause no problem as long as you stay under the rated max output of your regulator or like gibosi says only use one socket at a time.


----------



## mordy

Thanks for the answers to my questions - I'll play it safe and just use one tube at a time.


----------



## TrollDragon

mordy said:


> Thanks for the answers to my questions - I'll play it safe and just use one tube at a time.


 

 Here is a 5A module from China with LED voltmeter.
 http://www.ebay.com/itm/NEW-DC-DC-Step-Down-Power-Module-4V-38V-to-1-25V-36V-5A-Voltmeter-Adjustable/331064390176


 This should power anything you can roll with a decent source such as a laptop power supply which are usually 19V / 4.75A


----------



## mordy

HI TD,
  
 Thanks, looks like a good unit. The problem I have with my unit is that it seems that the LED voltage readout is stepped, and I cannot get it to read exactly 6.3V as an example. Either it reads 6.36V or 6.43V.
  
 However, within that 6.36V range I can still turn the set screw and lower/increase the voltage as measured with an external voltmeter. After some fiddling, I am able to set it to 6.3V (or 6.29-6.31V). Sometimes there is a little drift, and when rechecking, the voltage is a little higher or lower, but negligible.
  
 My eyesight isn't what it used to be, and sometimes it is hard for me to turn the little set screw with a jewelers flat blade screwdriver.
 Any suggestion how to attach a turning knob to the little brass set screw? (It takes quite a few turns to go from 6.3V to 12.6V.)
  
 Based on the picture, it seems that you need to attach a heat sink for higher power ratings. How do you attach it?


----------



## gibosi

mordy said:


> HI TD,
> 
> Thanks, looks like a good unit. The problem I have with my unit is that it seems that the LED voltage readout is stepped, and I cannot get it to read exactly 6.3V as an example. Either it reads 6.36V or 6.43V.
> 
> ...


 
  
 Delivering exactly 6.3 volts is not required. Anything between 6.2 and 6.4 is more than good enough. And I am quite sure that any setting between +/- 5% is also fine.
  
 And I too have been trying to figure out what I could attach to that tiny little brass screw to make it easily to turn with fingers only. I am hoping that someone out there with a clever solution will please share.


----------



## TrollDragon

Yes as gibosi say anything within 5% would be fine, there is no accuracy on a $10 Chi-nee LED readout regulator. 

Measure with a meter and if it is close enough to 6.3 or 12 then all is good.

Options for the little pot...
What I would do if I had one was measure the resistance of the pot in both 6.3 & 12 V setting (measure with power off after the setting is set and it might have to come off the board) then install a switch with a resistor that would give the appropriate value to toggle between 12 & 6.3 volts. The pot could stay in series with the resistor and the switch would cut it in or bypass it. If you have worked on circuit boards beforre this would be an easy mod.

You could also find a normal sized pot with the same value as the board one, remove the board one and run wires to the larger pot plus a way to mout the larger pot or let it hang. 

Epoxy a piece of plastic to the little screw top, like a piece of pen tube or QTip stick etc...


----------



## mordy

Thanks Gibosi and TrollDragon,
  
 Well, well TD,  you forgot about my secret weapon, the 8.4V tubes. Anyhow, the toggle switch solution is too complicated for me. However, a little plastic extension from the innards of a ball point pen might do the trick....


----------



## i luvmusic 2

If you google the code on your Pot you can get the resistance value of the pot Ex.mine is BOURNE 3296 W 203 so it is 10R-2M Pot.


----------



## TrollDragon

i luvmusic 2 said:


> If you google the code on your Pot you can get the resistance value of the pot Ex.mine is BOURNE 3296 W 203 so it is 10R-2M Pot.


The 203 shows that it is a 20K Ohm pot, since it is a 3 leg pot you would have to see if all 3 legs are hooked up in the circuit. Pins 1&3 give the whole 20K of resistance and pin 2 is the adjustable value. If you turn it so the resistance between pins 1&2 is 5K ohm the remaining resistance between pins 2&3 would be 15K. If they are using the pot as a voltage divider then there would be some calculations involved to bypass it with a switch. Probably easier to obtain a normal sized 20K pot and wire it in place of the little one.


----------



## i luvmusic 2

trolldragon said:


> The 203 shows that it is a 20K Ohm pot, since it is a 3 leg pot you would have to see if all 3 legs are hooked up in the circuit. Pins 1&3 give the whole 20K of resistance and pin 2 is the adjustable value. If you turn it so the resistance between pins 1&2 is 5K ohm the remaining resistance between pins 2&3 would be 15K. If they are using the pot as a voltage divider then there would be some calculations involved to bypass it with a switch. Probably easier to obtain a normal sized 20K pot and wire it in place of the little one.


 
 So in order for me to take a more accurate measurement on the pot i need to removed it from the PCB right?I turned the adjusting screw all the way up and measured it with my Multimeter and the reading is 11+K(Pin 1 to 3).Good thing Mordy mentioned about running 2 adapter from the same PS/Converter because i've been running both  LD 1 and LD MK III 6SL7/6SN7 adapter from the same PS/Regulator at the same time to burn-in the 2 tubes(6SN7) that i received and it works but when i switch one of the tube to 6SL7 it HUM(both amp),Do you think the HUM was cause by the PS/Regulator?Running 2 6SL7 at the same time is no HUM.Thank you for posting the ebay link i get to buy some parts that i needed to build a inclosed PS/regulator with LED(Votls and Amp. reading) Display i need to inclosed all the exposed electrical contacts(spiacially the VECTOR ADAPTER)i just got Shocked not long ago by those Vector adapter they can be hazardous.Need to take a measurement on top of LD 1 and LD MK III so i can buy or make a box/case to put the tubes on top so all the tube adapters are all inclosed.


----------



## Artsi

Heater voltages should be biased over cathode voltage. So between heater + and - is 6.3v, but minus side from amplifier zero should be more than cathode voltage. Otherwise with some tubes cathode starts to draw electrons from filament.

Do not know is it even possible to raise voltages above cathode with those heater power supplys...

Example with my diy amps heater voltages are biased about 30v above amps zero.


----------



## TrollDragon

mordy said:


> Based on the picture, it seems that you need to attach a heat sink for higher power ratings. How do you attach it?


 
 The heat sink has a thermally conductive sticky pad on the back.


----------



## TrollDragon

i luvmusic 2 said:


> So in order for me to take a more accurate measurement on the pot i need to removed it from the PCB right?I turned the adjusting screw all the way up and measured it with my Multimeter and the reading is 11+K(Pin 1 to 3).Good thing Mordy mentioned about running 2 adapter from the same PS/Converter because i've been running both  LD 1 and LD MK III 6SL7/6SN7 adapter from the same PS/Regulator at the same time to burn-in the 2 tubes(6SN7) that i received and it works but when i switch one of the tube to 6SL7 it HUM(both amp),Do you think the HUM was cause by the PS/Regulator?Running 2 6SL7 at the same time is no HUM.Thank you for posting the ebay link i get to buy some parts that i needed to build a inclosed PS/regulator with LED(Votls and Amp. reading) Display i need to inclosed all the exposed electrical contacts(spiacially the VECTOR ADAPTER)i just got Shocked not long ago by those Vector adapter they can be hazardous.Need to take a measurement on top of LD 1 and LD MK III so i can buy or make a box/case to put the tubes on top so all the tube adapters are all inclosed.


 
 After looking at the datasheet for the TI chip http://www.ti.com/lit/ds/symlink/lm2596.pdf bottom of page 12 provides resistor and inductor calculations for variable voltage, this pot or resistor has to have short leads and be close to the chip. This will eliminate the use of an external regular size pot unless it can be connected with very short leads.
  
 The number from your pot shows it to be 20K, if you only measure 11K then there are other board components affecting the measurement.
  
 Sounds like if the tube hums in both amps then it is probably the tube itself.


----------



## TrollDragon

artsi said:


> Heater voltages should be biased over cathode voltage. So between heater + and - is 6.3v, but minus side from amplifier zero should be more than cathode voltage. Otherwise with some tubes cathode starts to draw electrons from filament.
> 
> Do not know is it even possible to raise voltages above cathode with those heater power supplys...
> 
> Example with my diy amps heater voltages are biased about 30v above amps zero.


 
 The built in driver heater supply (AC) is already DC Biased.

 Connection at the top.
  
 With a pure DC heater supply I don't think the same thing applies but I am not 100% positive?


----------



## mab1376

Would this work as a driver for the MK IV with octal adapter and power supply?
  
 http://www.ebay.com/itm/Vintage-TUNG-SOL-JAN-CTL-12SA7GTY-Tubes-/261179404620


----------



## gibosi

mab1376 said:


> Would this work as a driver for the MK IV with octal adapter and power supply?
> 
> http://www.ebay.com/itm/Vintage-TUNG-SOL-JAN-CTL-12SA7GTY-Tubes-/261179404620


 
  
 This is a heptode with 5 grids.
  
 http://www.radiomuseum.org/tubes/tube_12sa7gt.html
  
 http://www.r-type.org/pdfs/12sa7.pdf
  
 If you wanted to use this in your LD, it would be best to have an octal breadboard socket to facilitate strapping the extra grids to the plate and/or cathode, that is, to convert it to a triode. So it could be done. However, in my opinion, it probably wouldn't be worth the time....


----------



## mordy

Hi,
  
 Bought a grab bag of ten 6SN7 tubes. One turned out to be a re-branded Japanese made tube. I have trouble finding information about Japanese octal tubes. Here are a couple of pictures. Can anybody tell me who made it and when?

  

  

  

  
 There is no information on the base. Brand Channel Master 6SN7GTB. Only inscription is J90 and Japan.
  
 Another question about the breadboard adapter: When I set the voltage regulator to 6.3V the voltage taken at the octal breadboard screw terminals for the heater wires read 6.10V. (The terminals at the voltage regulator read 6.3V). In order to get 6.3V at the socket on the breadboard I have to increase the voltage regulator to 6.49V.
  
 My other breadboard does not have this problem, and I get the same reading from the breadboard as from the voltage regulator.
  
 The octal breadboard needed little wires soldered in since it had provisions for inserting resistors. Could the little wires cause this?
  
 PS: Listening to the Channel Master octal tube. First impression very open and forward with wide sound stage with great width and height; punchy bass. Delicious....


----------



## i luvmusic 2

trolldragon said:


> After looking at the datasheet for the TI chip http://www.ti.com/lit/ds/symlink/lm2596.pdf bottom of page 12 provides resistor and inductor calculations for variable voltage, this pot or resistor has to have short leads and be close to the chip. This will eliminate the use of an external regular size pot unless it can be connected with very short leads.
> 
> The number from your pot shows it to be 20K, if you only measure 11K then there are other board components affecting the measurement.
> 
> Sounds like if the tube hums in both amps then it is probably the tube itself.


 
 Thanks for the info i need to wait until my other regulator and Display panel arrived the new regulator is the one that will be built inclosed with display panel and for the HUM it's the 6SL7 causing the hum.Again THANK YOU!


----------



## mab1376

i luvmusic 2 said:


> Thanks for the info i need to wait until my other regulator and Display panel arrived the new regulator is the one that will be built inclosed with display panel and for the HUM it's the 6SL7 causing the hum.Again THANK YOU!


 
  
 As MIKELAP said some tubes just hum, especially in the 6SL7/6SN7 family.
  
 best to ask your vendor before purchasing.


----------



## Oskari

mordy said:


> Bought a grab bag of ten 6SN7 tubes. One turned out to be a re-branded Japanese made tube. I have trouble finding information about Japanese octal tubes. Here are a couple of pictures. Can anybody tell me who made it and when?
> 
> There is no information on the base. Brand Channel Master 6SN7GTB. Only inscription is J90 and Japan.


 
  
 I can't find enough photos to be sure but my guess is Toshiba. If not Toshiba, then possibly Hitachi.
  
 You can see typical black-plate Hitachis (ITT-branded) and some grey-plate Toshibas at http://www.head-fi.org/t/479031/6sn7-tube-addicts/1830


----------



## hypnos1

gibosi said:


> If... I get a pair of these, I would like to remove the top metal cap, but is it possible to easily do so without disturbing the metal base?


 
  
 Hi folks.
 The adapters for the C3gSs are done (phew), so here are some photos & tips for anyone interested...
  
 gibosi - hope this shows how easy it is in fact to release tube from ugly canister...
  
 If you (or anyone) wish to re-attach the metal base, note the position of the 3 gaskets (pins 2, 5, and7), which may well fall out on extraction! (Second photo).
  

  
  
  


oskari said:


> It's quite a brilliant design that 'marker' being a _spigot_ in itself for the _socket_ that is the bottom metal part of the tube.


 
  
 The raised marker on the glass underside is not _very_ clear, but is visible enough to show the 1-8 position - 1, of course, (sorry to those much more experienced than I) being to the left and running clockwise to 8. The metal base also has one slot (pin 6) of a different shape to fit the tube base raised seats.
  

  
 You might just be able to see the tiny pieces of Teflon tube (leftover from speaker cable construction) I used to hold the silver wire to the tube pins for soldering, plus (hopefully) to give some mechanical connection also. A bit of 'white tack' - like plasticine - over the precarious protrusion - offers _some_ protection but, of course, still needed to be treated warily!
  

  
 Next, some tape around the pins to contain the first dose of 2-part rapid-setting resin - the joints MUST be well solidly bedded before even thinking of bending those would-be pins!...
  

  
 Finally, over the wire/cum pins went half a 7-pin ceramic socket then a small, drilled disc of 5mm plastic (from an old chopping board) - 5mm being the socket inset, on the MKIV at least. For the last enclosure I used a piece of 26mm internal diam. aluminium tube (from some old tree loppers - well, necessity is the Mother...etc.etc.), suitably mauled at the rear to provide a gap (so who's gonna see it?!) for pouring in the final resin sealant. A snip of the wire pins to 7mm and a smoothing of any burrs...
 (Edit...internal diam. changed to 26mm)
  
 et voila!
  

  
 (The tube is sitting in a glass egg-cup, in case you were wondering!).
 The finished article doesn't look _too_ out-of-place on the LD?...But some lovely, large, curvy rectifier-type tubes behind would certainly look much better - but after what I paid for those 6N30P-DRs, the look will have to stay!!
  

  
 I must admit this job is a bit tricky, but I myself am quite a novice to this sort of thing (especially soldering). But with due care and diligence; careful planning; _more_ care and diligence; patience and soldering practice, if necessary, this is not TOO difficult a task for most people. Using a loctal socket would be safer than attaching direct to the tube pins, that's for sure, but would make for a somewhat bulkier adapter... Otherwise, gibosi's 'breadboard' method , to a pair of Vector sockets, may suit those who do not feel confident in such construction. But I am sure this route must degrade the end result somewhat...especially if TOP grade wire isn't used. I firmly believe the 1.2mm silver wire I had doubling up as the pins has contributed to the magical sound I am now getting (or perhaps I'm deluding myself!...).
 Whatever, I really do hope someone else gives these amazing tubes a try...
  
  
  
  
  
  


mab1376 said:


> Did you test the cg3 vs the cg3s?
> 
> also what is the price you paid if you don't mind me asking, they don't seem to have a price posted anywhere.
> 
> ...


 
  
 With just 15hrs on the C3gSs, I must admit (and I just can't believe it possible) they _are_ sounding even better than the 'ordinary' ones. I suppose the only way I can describe the difference is there seems to be more _weight_ to the overall sound - especially in the bass (plus a bit more detail) and mids. But with no adverse effect on the high end either, nor the wonderful spacious airiness and pin-point imaging...how do they do it? There is also even more detail - the already amazing handling of transients and micro-detail goes to another level.
 In other words, if you do go for C3gs, the 'S's are the ones to possibly keep looking for - if they _do_ surface , and the PRICE IS RIGHT!  But even if not, the 'plain' ones are still utterly wonderful and would not disappoint, I am sure.
 ps.  The S's tops are _slightly_ flatter than the plains - otherwise they look totally identical.


----------



## mordy

Hi Oskari,
  
 Thanks for the info and the pictures. The tube I have does not match any of the pictures - especially the mica plates are different.









  
 I guess it is safe to say that it was made by MaHiTo (Matsushiita/Hitachi/Toshiba) LOL.


----------



## gibosi

Received an ECC40 today. This is an 8-pin double triode (6.3V, 0.6A) with what is called a "Rimlock" base (B8A). All the pins are equidistant and evidently, the little glass nub close to the base is used for alignment. The groove where the foot is joined to the bottle indicates that it was manufactured using Philips production equipment. For example, tubes manufactured by Tungsram do not have this groove.
  
 Apparently, this tube was designed by Philips to replace the 6SN7GT, but it seems it was not a commercial success, and had a production run of only 3 years, from 1948 through 1951 (according to one source). And interestingly, "Made in Holland" is silk-screened on this tube, but the tube code (+9B8) suggests it was manufactured by La Radiotechnique, Chartres, in 1949.
  
 From Google, a number of people have reported that this is a very good tube for audio, but unfortunately, my adapter is still sitting in San Francisco....
  
 Edit: I can't believe that this tube was manufactured in 1949. To my mind, the 0-getter and 4-digit Phililps tube code suggests 1959 or even 1969. Perhaps Oskari will be able to shed more light on this....  
 Edit2: Oh, he did!! And I will another look at the tube code.


----------



## gibosi

hypnos1 said:


> The adapters for the C3gSs are done (phew), so here are some photos & tips for anyone interested...


 
  
 Thanks for the very informative post!
  
 As I am quite comfortable with ugly external sockets and an auxiliary heater PS, I am inclined to try a pair of C3ms. They are fairly plentiful and relatively inexpensive, perhaps due to the fact that they require 20V heaters. However, I am still quite enamored with 6SN7s and eager to hear my new ECC40, so these C3-pentodes (C3m, C3o and C3g) will probably sit on the back burner for a bit longer.


----------



## Oskari

gibosi said:


> Received an ECC40 today. ...
> 
> Apparently, this tube was designed by Philips to replace the 6SN7GT, but it seems it was not a commercial success, and had a production run of only 3 years, from 1948 through 1951 (according to one source). And interestingly, "Made in Holland" is silk-screened on this tube, but the tube code (+9B8) suggests it was manufactured by La Radiotechnique, Chartres, in 1949.


 
  
 Rimlock tubes were common in Europe, for a while.
  
 Unless the date code is somehow exceptional, this must be a 60s or later code. That's because there's a character in the week number position. The week number, however, should be 1, 2, 3, 4 or 5, not 8. Can you check this?
  
 What does the other part of the code look like?


----------



## gibosi

oskari said:


> Rimlock tubes were common in Europe, for a while.
> 
> Unless the date code is somehow exceptional, this must be a 60s or later code. That's because there's a character in the week number position. The week number, however, should be 1, 2, 3, 4 or 5, not 8. Can you check this?
> 
> What does the other part of the code look like?


 
  
 Looking more carefully, that 8 is actually a 3. And the rest of the tube code is LC4 = ECC40, revision 4.


----------



## Oskari

gibosi said:


> Looking more carefully, that 8 is actually a 3. And the rest of the tube code is LC4 = ECC40, revision 4.


 
  
 Thanks! Probably 1969 then (rather than 1979). Do you agree?


----------



## gibosi

oskari said:


> Thanks! Probably 1969 then (rather than 1979). Do you agree?


 
  
 Yes, 1969 makes the most sense to me. The only thing that seems a bit off is this implies there were only 4 revisions since the tube was introduced some 20 years earlier. But since the tube seems not to have been nearly as important to Philips as tubes such as the ECC82 and ECC88, then I would guess it is likely that very few resources were devoted to its development and improvement over that period of time.


----------



## hypnos1

gibosi said:


> Thanks for the very informative post!
> 
> As I am quite comfortable with ugly external sockets and an auxiliary heater PS, I am inclined to try a pair of C3ms. They are fairly plentiful and relatively inexpensive, perhaps due to the fact that they require 20V heaters. However, I am still quite enamored with 6SN7s and eager to hear my new ECC40, so these C3-pentodes (C3m, C3o and C3g) will probably sit on the back burner for a bit longer.


 
  
 Thanks for your reply, gibosi.
  
 Considering your marathon with different tubes, I can certainly understand another project needing to take its place in the queue on that (large!) burner...a shame really...
  
 However, methinks you should definitely be awarded the honour of 'Master Roller' for all your tremendous efforts - WELL DONE, and long may you prosper!
  
  
 mab1376 :
  
 With another 17 hours on the C3gSs, I continue to be totally blown away by this family...in addition to the differences I mentioned previously (all of which are even greater!), the already unnerving ability to resolve difficult elements such as a fast drum run with total aplomb is also surpassed with the Ss. As is the case with reproducing a note from clean attack/strike thru delicious decay throughout the frequency range (but especially noticeable with piano), with no single one dominating at the expense of others...And as for 'holographic sound'..I am lost for words now. All I can say (to anyone) is KEEP SEARCHING for the 'Ss' if you decide to give these C3gs a try. These things (especially the Ss) are lightyears ahead of where we started from.
  
 Cheers from someone currently on another planet!!


----------



## CollectoR13

Glad I bought c3gS...
I think I wont be disappointed with the change i plan to make to the tubes.

Btw, do you think the 6sn7 as power tube does make big difference vs my 6h30?

Oh and forgot to thank for the explanation of tube pin abbreviations!


----------



## mab1376

hypnos1 said:


> mab1376 :
> With another 17 hours on the C3gSs, I continue to be totally blown away by this family...in addition to the differences I mentioned previously (all of which are even greater!), the already unnerving ability to resolve difficult elements such as a fast drum run with total aplomb is also surpassed with the Ss. As is the case with reproducing a note from clean attack/strike thru delicious decay throughout the frequency range (but especially noticeable with piano), with no single one dominating at the expense of others...And as for 'holographic sound'..I am lost for words now. All I can say (to anyone) is KEEP SEARCHING for the 'Ss' if you decide to give these C3gs a try. These things (especially the Ss) are lightyears ahead of where we started from.
> 
> Cheers from someone currently on another planet!!


 
  
 Thanks for the info, I'll definitely consider them if i can make an easy adapter using a LOCTAL socket.
  
 For now i have my PSU board on the way and I'm going to use the 6SU7GTY tube i have on the way with two 6SN7GTB's as power tubes.


----------



## hypnos1

collector13 said:


> Glad I bought c3gS...
> I think I wont be disappointed with the change i plan to make to the tubes.
> 
> Btw, do you think the 6sn7 as power tube does make big difference vs my 6h30?
> ...


 
  
 You lucky feller - I am sure those C3gSs will blow you away. Well chosen...
  
 The general concensus (for the LD anyway) seems to have been that the power tubes  - unless paying BIG bucks for the 6N30P-DR 'Supertubes' - do not have a great influence on the sound, certainly if you have the gold-pin 6H30Pi-EH. However, Artsi seems to like the 6SN7s and mab1376 is going to be trying some , so perhaps we shall have some comparisons coming in very soon?...Should prove very interesting.
  
 And I believe it was gibosi who helped you re. the pins, so it's thanks to him...
  


mab1376 said:


> Thanks for the info, I'll definitely consider them if i can make an easy adapter using a LOCTAL socket.
> 
> For now i have my PSU board on the way and I'm going to use the 6SU7GTY tube i have on the way with two 6SN7GTB's as power tubes.


 
  
 Yes mab, PLEASE consider them seriously...I am desperate for some other opinions!! If you do go ahead, please feel free to get in touch if you have any questions/doubts re. the tube and/or  adapter. Perhaps I might be able to help...(this goes for anyone else who wants to give them a try).
 Look forward to your impressions of the 6SN7GTBs as power tubes.


----------



## Oskari

mordy said:


> Thanks for the info and the pictures. The tube I have does not match any of the pictures - especially the mica plates are different.


 
  
 You are close to the answer when you find a branded one that is an exact match.
  


> I guess it is safe to say that it was made by MaHiTo


 
  
 Or TeNeMaHiTo.


----------



## Oskari

hypnos1 said:


> The raised marker on the glass underside is not _very_ clear, but is visible enough ...


 
  
 I see your 'marker' wasn't exactly the thing I thought it was.


----------



## Oskari

gibosi said:


> Yes, 1969 makes the most sense to me. The only thing that seems a bit off is this implies there were only 4 revisions since the tube was introduced some 20 years earlier. But since the tube seems not to have been nearly as important to Philips as tubes such as the ECC82 and ECC88, then I would guess it is likely that very few resources were devoted to its development and improvement over that period of time.


 
  
 Sounds plausible. There probably was a limited replacement market for which batches were produced only every now and then.


----------



## gibosi

My ECC40 to 6DJ8 adapter arrived yesterday and I was able to spend a couple hours with the Philips ECC40 last night. This is a seriously good tube folks. My go-to tube recently has been the small-bottle Sylvania 6SN7W, and this ECC40 is just as good.
  


Spoiler: 1945 Small bottle Sylvania 6SN7






  
 As a colleague likes to say, the differences are not black and white, but shades of gray. The Sylvania is just a tad bit darker and the Philips is just a tad bit brighter, but otherwise, from top to bottom, both of these are top-tier.
  
 Philips manufactured these tubes in at least three factories. La Radiotechnique, Chartres, Valvo Hamburg, and either CIFTE (Compagnie Industrielle Francaise Des Tubes Electroniques) or Philips, Sittard. I have seen Mullard ECC40/CV3884 on eBay, so perhaps Mullard also manufactured these tubes. The tube codes are typically etched into the foot of the tube around the pins.
  
 My tube - La Radiotechnique, Chartres (I am pretty sure the factory symbol is a + with an underline, that is "+", and not the Siemens symbol). I have seen Philips and Siemens tubes with these codes.
  

  
 Valvo, Hamburg (Factory symbol = D). I have seen a Siemens with this code, so I don't think Siemens manufactured this tube.
  




  
 CIFTE. (factory symbol = malformed "t") or Sittard, Holland (factory symbol "+") I am inclined to think it is CIFTE, as I think Sittard would more likely have used the standard Philips format, FYMW. Further, I have seen two Darios with this code, which again leads me to think CIFTE France production.


----------



## Oskari

gibosi said:


> CIFTE. (factory symbol = malformed "t") or Sittard, Holland (factory symbol "+") I am inclined to think it is CIFTE, as I think Sittard would more likely have used the standard Philips format, FYMW.


 
  
 Both are Philips formats, 'old' code (from 1948 to 1955 or 1956) and 'new' code (later on) as described by Blake. The week was added to the 'new' code in about 1961. 
  

http://tubedata.milbert.com/other/Philips/PhilipsCodeListAB-v10.pdf


----------



## gibosi

oskari said:


> Both are Philips formats, 'old' code (from 1948 to 1955 or 1956) and 'new' code (later on) as described by Blake. The week was added to the 'new' code in about 1961.
> 
> 
> http://tubedata.milbert.com/other/Philips/PhilipsCodeListAB-v10.pdf


 
  
 Thanks! The info on 'old' code tells me that the Hamburg tube, above, was manufactured in September, 1953. And it now seems likely that "+" indicates the Sittard, Holland factory, and that tube was manufactured in March, 1953.
  
 And just today, I learned that the ECC40 was also manufactured in the La Radiotechnique, Suresnes factory and the Thorn-AEI Radio valve Co. Ltd. (Ediswan) factory. The Suresnes and Ediswan tubes I saw carry the Mullard label and were manufactured in the 1970s (LC5 F2J4 = 1972 and LC5 I8H2 = 1978).
  
 So it appears the ECC40 was manufactured for a period of time lasting at least 30 years, starting in 1948, in at least 5 different Philips factories, plus Tungsram....
  
 Happy rolling! lol


----------



## mordy

Hi,
  
 Seems that part of the performance of a vacuum tube is resistance to internal vibration. If vibration/oscillation of internal components can be prevented or minimized, it should result in less micro-phonics and better sound.
  
 Read somewhere that the "mouse ears" on the top mica on some Tung Sol octal tubes were made in an attempt to brace the internal components against the glass envelope, but the writer claimed that it did not work.




  
 Here is a picture of a 6CG7 tube with spring loaded C-clamps on the top mica to clamp down the internals:
 Here is another tube from my  6SN7 260 stash: It is labeled Hoffman Easy Vision. The number 274 indicates that it was made by RCA; the manufacturing date is Sept 1965. On the top mica is a an interesting mounting of the heaters with a wire connecting them:
  


 (Hoffman was a California based company that made TVs from 1948 - 1977).
  
 Anybody knows the purpose of the wire arrangement on the top mica?
  
 Finally, there are lots of ads on Ebay for damping rings:




  
  
 Snake oil, or do they help?
  
 "Madam, you car needs to have the muffler bearings greased".  lol....


----------



## mab1376

mordy said:


> Snake oil, or do they help?
> "Madam, you car needs to have the muffler bearings greased".  lol....


 
  
 My 6HM5 are extremely microphonic with my T70's since they are so sensitive. if you tap it with your nail you can hear a high pitched ring like a bell. I think it would stop that but not much else. Probably not a good idea to be tapping tubes anyway while they're on anyway.
  
 I can notice the ring as music starts too and stays there subtlety in the background. Don't notice it at all with my HD650's.


----------



## gibosi

This link was posted over in the Schiit Lyr Tube Rollers thread, but think it deserves a wider posting.

 http://www.ominous-valve.com/hifi.html
  
 "It's a movement. It's the Mister Valve anti-sonic-massacree movement, and you're in it."


----------



## kvtaco17

My adapter for 6SN7's arrived! Rolled in the Sylvania 6SN7GTB I have and so far so good... such sound, much dynamic... wow lol
  
 Really diggin this setup so far... BUT how will it compare to my trusty US Raytheon 6CG7? More to come!


----------



## gibosi

kvtaco17 said:


> My adapter for 6SN7's arrived! Rolled in the Sylvania 6SN7GTB I have and so far so good... such sound, much dynamic... wow lol


 
  
 Welcome to 6SN7 land! But watch out, these tubes can be addictive! lol


----------



## CollectoR13

My siemens C3GS and sylvania 6sn7gt arrived!
I am usually not that into looks, but this tubes are looking so beautiful!
I am so desperate to try them, but unfortunally my Sockets for the C3GS didn't arrive yet...
Now I have to build everything together into a clean black case, I hope the silver wire I bought is not too stiff, hopefully it will serve its purpose.
I will make a table for the 6n6p to 6sn7 conversion, could anyone correct it if its wrong?
I will uplpad it soon!

Thanks guys!


----------



## CollectoR13

This is my conversion table for 6n6p to 6sn7!
 I would appreciate if you tell me if there is anything wrong with it!

  
 BTW, what does S in a tube diagram mean?


----------



## gibosi

collector13 said:


> This is my conversion table for 6n6p to 6sn7!
> I would appreciate if you tell me if there is anything wrong with it!
> 
> 
> BTW, what does S in a tube diagram mean?


 
  
 Your conversion table looks fine to me.
  
 S = Shield. The 6N6P (and 6DJ8) have a metal shield between the two triodes while the 6SN7 does not. And so in this translation, you can ignore pin 9.


----------



## CollectoR13

Thank you very much for your help, gibosi!
I wanted to stay on the safe side, not that I blow up those sylvanias lol...


----------



## ostewart

I don't have a little dot, but i thought I would post here. Just got a XDuoo TA-02 which uses the 6J1 as stock, terrible tube. Also one failed after 30 mins of being plugged in (white cloud at the bottom, bass sounded awful).
  
 So I decided to buy a pair of Mullard 5654 tubes off ebay. Got them today, put them in, and wow what a difference, brilliant body, the mids are a tad too warm sometimes, and the highs are a little less sparkly but the overall sound is much better. The are aged around 1964, Mitcham Factory, July, Week 4 (R4G4 code). Nice tubes, makes me want to try the Voshkod...
  
 The TA-02 is a great little budget amp, for $112 retail it is incredible value, hybrid design.
  
 Thanks for the guide. Using modded Grado SR-60's out of it at the moment.


----------



## TrollDragon

The TA-03 looks interesting, with a lot of rolling possibilities...

http://www.xduoo.com/xduoo/ProductShow.asp?id=41


----------



## MIKELAP

ostewart said:


> I don't have a little dot, but i thought I would post here. Just got a XDuoo TA-02 which uses the 6J1 as stock, terrible tube. Also one failed after 30 mins of being plugged in (white cloud at the bottom, bass sounded awful).
> 
> So I decided to buy a pair of Mullard 5654 tubes off ebay. Got them today, put them in, and wow what a difference, brilliant body, the mids are a tad too warm sometimes, and the highs are a little less sparkly but the overall sound is much better. The are aged around 1964, Mitcham Factory, July, Week 4 (R4G4 code). Nice tubes, makes me want to try the Voshkod...
> 
> ...


 
 You might want to check page 77 of this thread if your amp uses ef95 type tubes theres some there and usually around $3.00to $5.00 each and up


----------



## ostewart

Nice, will take a look. Might try and get the TA-03 after I've reviewed the TA-02, but the TA-02 is impressive in it's own right for a budget amp. I have the Bravo Audio Ocean too. I prefer the look of the TA-02 and the double tubes. The Ocean is more versatile in having both 3.5 and 6.3mm outputs, RCA and 3.5mm line in and also RCA out as a preamp.
 Soundwise, depends on tubes i think, i haven't tried the 12AU7 mullard's i have in the Ocean as mine was faulty and I'm waiting for the replacement.


----------



## i luvmusic 2

Since some of us here have external PS with octal adapter anyone tried using 12SN7 and is it safe to use with LD?


----------



## gibosi

i luvmusic 2 said:


> Since some of us here have external PS with octal adapter anyone tried using 12SN7 and is it safe to use with LD?


 
  
 Yes, I have run 12SN7s and 25SN7s, and it is perfectly safe.


----------



## i luvmusic 2

gibosi said:


> Yes, I have run 12SN7s and 25SN7s, and it is perfectly safe.


 
 Hi gibosi,in your opinion does it sound better than 6SN7 and what is the benefits of using it?THANKS!


----------



## gibosi

i luvmusic 2 said:


> Hi gibosi,in your opinion does it sound better than 6SN7 and what is the benefits of using it?THANKS!


 
  
 In my opinion, the only benefit is sometimes the 12V and 25V tubes are cheaper. Otherwise, there is no difference. For example, a gray-glass 6SNGT RCA sounds exactly the same as the 12V and 25V versions.


----------



## mordy

Hi kvtaco17,
  
 I am going through a lot of ten 6SN7 tubes I bought. They are all good, RCAs, Sylvanias, GE and a Japanese TenHiMaTo. Previously, I bought a bunch a 8 volt 6FQ7/6CG7 cousins - 8FQ7/8CG7 tubes. So far, the nod goes to the Japanese and Sylvania tubes.
  
 These tubes are a development of the 6SN7 family with the same pinout as the 6DJ7 family. Maybe I am imagining, but I find the 8V 8FQ7 tubes to have more bass punch than the 6FQ7 tubes. (I know, they are supposed to sound the same, just different heaters. There are also 12V variants, but some high end amps use them, and I can't find these tubes at really low prices.) The best 8FQ7/CG7 tubes so far have been Japanese and Sylvania tubes - sounds familiar, eh?
  
 The difference between the 6SN7 and 6/8FQ7 tubes IMHO is that the 6SN7 tubes are more musical and sweeter, and 6/8FQ7 are more detailed and somewhat analytical, with punchier bass.
  
 Both tube families are wonderful to listen to; it's really a matter of taste and perhaps how they match your equipment. In addition, 6SN7 tubes are extremely common with thousands of offers on Ebay. The 6/8CQ7 tubes aren't as common, but can be found very inexpensive as well.
  
 I can't compare these $2-4 tubes to ones costing $30-100 each because such tubes are beyond my self imposed limit, but I am inclined to think that they are just as good as the expensive exotic or hyped up tubes.
  
_Anybody out there who can give me an opinion on tube damper rings?_


----------



## TrollDragon

mordy said:


> _Anybody out there who can give me an opinion on tube damper rings?_


 
 Available in 298 sizes around $8 per 100, pick your size and go!

 http://www.amazon.com/Silicone-O-Ring-70A-Durometer-Red/dp/B003SLE5LS


----------



## mordy

Hi TD,
  
 A little reading seems to say that these rings help for tubes that rattle. So far, I never came across a tube that rattles. (Well, one of my octals had a loose piece inside but since it does not seem to affect the sound, and since I cannot hear it rattling when playing music, I ignored it.)
  
  
 http://herbiesaudiolab.net/rx.htm
  
 Seems to be some kind of consensus that Herbie's dampers work. At a cost of $29 each I am not inclined to try them yet.
  
 There is a 90 day no risk trial - your money back if not satisfied. Hmm....


----------



## TrollDragon

mordy said:


> Hi TD,
> 
> A little reading seems to say that these rings help for tubes that rattle. So far, I never came across a tube that rattles. (Well, one of my octals had a loose piece inside but since it does not seem to affect the sound, and since I cannot hear it rattling when playing music, I ignored it.)
> 
> ...


 
  
 If you have a tube that is susceptible to microphonics then they *might* solve the issue, most people just change the tube...
 And at $30 a pop, they are a nice bit of tube jewelery...
  
  
 And then you read stuff like this from his site...







> *PTFE-coated silicone O-rings* fare better. These industrial seals, available from McMaster-Carr and other hardware suppliers, tend to improve the sound of tubes suffering particularly from microphonics or tube rattle, adding only a slight frequency coloration. Some users have reported satisfactory results with these. With some tubes, however, *they induce a bloopy, muddied bass and/or high-frequency loss and/or upper-mid harshness*. Because PTFE softens and elongates with higher temperature, results can be unpredictable when in direct contact with the radiant heat of tube glass.


----------



## mordy

Hi TD,
  
 Just what I thought, bloopy snake oil....


----------



## mordy

Hi,
  
 Listening to a RCA 6SN7 tube from 1967 that sounds great.


 I have two such tubes from 1965 and 1967 in my 260 stash. One is pictured above; the other one says RCA but lacks the 6SN7 designation on the tube. Both have clear tops with that funny little wire on top.
 The getter is in the bottom of the tube. I assume that the getter flash is there also, but it must be covered by the bakelite base because I cannot see it. Another interesting construction detail is that all the wires internally have been brought into one vertical plane and encased in some kind of glass.

  

  
  
 Can't remember reading about these tubes as great sounding tubes, but they really sound delicious. The sound stage is remarkable - wide, holographic. Does anybody have experience with these tubes?


----------



## i luvmusic 2

gibosi said:


> In my opinion, the only benefit is sometimes the 12V and 25V tubes are cheaper. Otherwise, there is no difference. For example, a gray-glass 6SNGT RCA sounds exactly the same as the 12V and 25V versions.


 
 THANK YOU!


----------



## i luvmusic 2

I was on my way to buy some MDF board to build the inclosure for my amp/tubes and on the  curb someone dump a old YAMAHA AMP i picked it up and  here is what i came up with.
  

  

 I will be keeping these for a while.


----------



## hypnos1

collector13 said:


> My siemens C3GS and sylvania 6sn7gt arrived!
> I am usually not that into looks, but this tubes are looking so beautiful!
> I am so desperate to try them, but unfortunally my Sockets for the C3GS didn't arrive yet...
> Now I have to build everything together into a clean black case, I hope the silver wire I bought is not too stiff, hopefully it will serve its purpose.
> ...


 

  Hey C. Don't know if you have sprung the C3gSs from prison yet, but they DO look beautiful!
 Congrats on the silver wire - these tubes certainly deserve some special treatment. Hopefully you got _soft-annealed_ wire, which is supposed to be better for sonic performance, and is quite easy to bend.
 Remember to give them a good period of burn-in for the _real_ magic to appear - I personally found they kept improving up to 30+ hours (how much is due to burn-in of the tube and how much to the new wire/adapter I couldn't say).
 Good luck with your efforts...I really look forward to your impressions.


----------



## ostewart

Here's the xDuoo with the Mullard's:


----------



## mordy

Hi,
  
 Listening to a RCA 6SN7 tube from 1967 that sounds great.


 I have two such tubes from 1965 and 1967 in my 260 stash. One is pictured above; the other one says RCA but lacks the 6SN7 designation on the tube. Both have clear tops with that funny little wire on top.
 The getter is in the bottom of the tube. I assume that the getter flash is there also, but it must be covered by the bakelite base because I cannot see it. Another interesting construction detail is that all the wires internally have been brought into one vertical plane and encased in some kind of glass.

  

  
  
 Can't remember reading about these tubes as great sounding tubes, but they really sound delicious. The sound stage is remarkable - wide, holographic. Does anybody have experience with these tubes?


----------



## TrollDragon

Hi mordy!
  
 It's like *Déjà vu*, did you not just post that a few hours ago?
  
post #5114


----------



## MIKELAP

trolldragon said:


> Hi mordy!
> 
> It's like *Déjà vu*, did you not just post that a few hours ago?
> 
> post #5114


 
 Theres probably a tear in the space time continuum TD thats why !.


----------



## TrollDragon

mikelap said:


> Theres probably a tear in the space time continuum TD thats why !.


 

 Using those tubes must be creating a tear in the magical fabric...
 I need to quickly find a _Sonic Screwdriver_ just in case...


----------



## MIKELAP

trolldragon said:


> Using those tubes must be creating a tear in the magical fabric...
> I need to quickly find a _Sonic Screwdriver_ just in case...


 
 No its ok ill beam one down Scotty i mean TD !


----------



## mordy

Hi TD and Mikelap,
  
 Was worried that nobody read my edited post where I added on pictures. Seriously, I think that these tubes are very special. I wish  somebody could confirm (or dispute) my impressions about these tubes, as well as the 8FQ7 Japanese or Sylvania tubes.
  
 So many great tubes, and at bargain prices as well - I feel like a kid in a candy store.....
  
 In case somebody needs an idea for a birthday present, I found this great suggestion:
  




 Have fun!


----------



## gibosi

mordy said:


> Was worried that nobody read my edited post where I added on pictures. Seriously, I think that these tubes are very special. I wish  somebody could confirm (or dispute) my impressions about these tubes, as well as the 8FQ7 Japanese or Sylvania tubes.


 
  
 In my opinion, the small-bottle Sylvania 6SNGT and 6SN7GTA from the late 1940's and early 1950's are great buys, often very cheap, with deep bass, natural sounding vocals and crystal clear highs. The Sylvania 6SN7WGT and 6SN7GTA are also great sounding tubes, but I don't find them to sound significantly different than the regular GTs and GTAs, and don't believe they are worth the extra cost. My only criticism of these small-bottle Sylvanias is that on some recordings, I find the mid-range to be just a tad bit thin and dry. But on most recordings, I find these tubes to be very enjoyable. Strongly recommended.
  
 I was going to purchase a Japanese Raytheon 8FQ7 to have the same tube Mordy favors so highly. However, due to a mix up of some sort, while I successfully purchased this tube, it was in fact not available. So I got my money back, but I didn't get the tube. However, I dug out the 8FQ7s I purchased some time ago, and it appears that two of them are Japanese. One looks to be a Toshiba, but I am not at all sure about the second one. Will take some pictures and post them tomorrow.....


----------



## gibosi

Two Japanese 8FQ7
  
 Comparing the first tube to pictures on the web, I believe this to be a Toshiba 8FQ7, with short square plates and a small O-getter. Unfortunately, other than the circled H, which I have seen on other tubes made by Toshiba, any printed text or graphics has rubbed off. 
  

  
 The second tube has "Japan" and the date "7022" printed on it, and it carries the IEC brand which might indicate a Mullard - Matsushta connection. However, I have also seen these long, gray, flat-ladder plates on tubes made by Toshiba and Hitachi.
  

  
 Mordy, do either of these resemble yours?


----------



## gibosi

mordy said:


> Listening to a RCA 6SN7 tube from 1967 that sounds great.
> 
> Can't remember reading about these tubes as great sounding tubes, but they really sound delicious. The sound stage is remarkable - wide, holographic. Does anybody have experience with these tubes?


 
  
 The only RCA I have is the 1940's smoked-glass gray 6SN7GT, and I would describe it similarly, very warm with a huge sound stage. As I have said before, I think it conveys an exquisite balance of warmth and detail. However, I have never heard the later RCAs so cannot say how they might compare....
  
 In my experience, live music is much warmer, with more bass and less detail, than the rather cool, analytical, ultra-detailed sound that many headfi enthusiasts prefer. Given that I tend to swing on the warm and bassy side, the signature sound of the 6SN7, with its strong bass and warm presentation, is very appealing to me. And in fact, the 1940's RCA could be called the poster child of the 6SN7. Listening to this tube, with its strong bass and reverberations bouncing off all the walls, transports me into a wide, deep, 3-D performance space. Yes, sometimes it does seem to be a bit too syrupy and sometimes I would welcome a bit more detail, but most of the time, it is simply delicious. Strongly recommended unless you are a detail freak.


----------



## hypnos1

gibosi said:


> The only RCA I have is the 1940's smoked-glass gray 6SN7GT, and I would describe it similarly, very warm with a huge sound stage. As I have said before, I think it conveys an exquisite balance of warmth and detail. However, I have never heard the later RCAs so cannot say how they might compare....
> 
> In my experience, live music is much warmer, with more bass and less detail, than the rather cool, analytical, ultra-detailed sound that many headfi enthusiasts prefer. Given that I tend to swing on the warm and bassy side, the signature sound of the 6SN7, with its strong bass and warm presentation, is very appealing to me. And in fact, the 1940's RCA could be called the poster child of the 6SN7. Listening to this tube, with its strong bass and reverberations bouncing off all the walls, transports me into a wide, deep, 3-D performance space. Yes, sometimes it does seem to be a bit too syrupy and sometimes I would welcome a bit more detail, but most of the time, it is simply delicious. Strongly recommended unless you are a detail freak.


 
  
 Hi g.
 So you like syrup eh? Me - I prefer _honey_! Preferably with lots of different, subtle flavours...which is what I am getting from my C3gSs!! The thing about uber detail is that music you have heard many times becomes something wonderfully new and showcases the sound engineer's craft - given a decent performance in the first place! These babies have detail in abundance, and sometimes I can't believe I am listening to the same tracks I have heard _many_ times before...Plus, tracks I never previously had any time for suddenly have me thinking - my goodness, now I can understand why they were included in the album.
 So, mon ami, if this doesn't appeal, I think you had best move them a bit further to the back of the burner!! BUT, I have a sneaky feeling that if you found the right pieces of music you just _might_ also catch the 'bug'...who knows?...
 Whatever, I'm glad all your research is bearing fruit for your (poor?! Edit: they are indeed true martyrs to the cause) ears.
  
 Cheers.


----------



## mordy

Hi Gibosi,
  
 I have three different Japanese 8FQ7/6CG7 tubes. The first tube you pictured is identical to one of mine. The H indicates Toshiba (not Hitachi - go figure), and I labeled this one as Very Good. I don't have any other markings than you, so I don't think that they rubbed off - they simply weren't there to begin with.
  
 The star of the three is the Raytheon/Hitachi tube - sorry you did not get it.
  
 The third tube is labeled Silvertone (Radio Shack?) and has the markings AAF and 635. Gave this tube an Excellent rating.
  

 This Silvertone tube could be made by any of the major Japanese manufacturers, Ten, Hitachi, Toshiba, Matsushiita.
  
 About dating: What would be an educated guess for 635? The 35th week 1966?


----------



## gibosi

mordy said:


> The star of the three is the Raytheon/Hitachi tube - sorry you did not get it.
> 
> The third tube is labeled Silvertone (Radio Shack?) and has the markings AAF and 635. Gave this tube an Excellent rating.
> 
> About dating: What would be an educated guess for 635? The 35th week 1966?


 
  
 I expect that one of these Japanese Raytheons will pop up on ebay eventually....
  
 "Silvertone" was a Sears Roebuck brand back in the day. And 1966 seems like a good guess to me, but who knows?


----------



## gibosi

hypnos1 said:


> So you like syrup eh? Me - I prefer _honey_! Preferably with lots of different, subtle flavours..


 
  
 lol.. Well yes, sometimes the RCA is a bit too syrupy for sure, but it does a wonderful job of recreating a sense of being in a live performance space, and on some recordings, it is quite spectacular. However, the 6SN7 that spends the most time in my LD is a 1945 short-bottle Sylvania 6SN7W. It compares very well with my Heerlen-made E80CC, which is the most neutral and linear tube I have, with similar detail, but a stronger and more propulsive bass. So as of this moment, these are my top two tubes.
  
 Eventually, I do intend to get to the C3-pentodes. But as they will require a significant reworking of my current configuration, swapping two loctal sockets for one 9-pin, I want to wait until I have finished exploring the ECC40s....
  
 Cheers,


----------



## mab1376

Has anyone tried any VT-99 tubes?


----------



## gibosi

mab1376 said:


> Has anyone tried any VT-99 tubes?


 
  
 I haven't, but they have gotten a fair amount of love over in the 6SN7 Tube Addicts thread. As it is simply a 6F8G, all you need is an octal socket and an adapter like this:
  
 http://www.ebay.com/itm/Tube-adaptor-6F8G-to-6SN7-Socket-/400667131972?pt=Vintage_Electronics_R2&hash=item5d499f4044


----------



## Nic Rhodes

6F8G are great tubes if you have quiet one, BL63 better again. Re the former Tung Sol are the prefered with round plates but I have found many other good examples out there with and without both round plates and Tung Sol logos.


----------



## mab1376

gibosi said:


> I haven't, but they have gotten a fair amount of love over in the 6SN7 Tube Addicts thread. As it is simply a 6F8G, all you need is an octal socket and an adapter like this:
> 
> http://www.ebay.com/itm/Tube-adaptor-6F8G-to-6SN7-Socket-/400667131972?pt=Vintage_Electronics_R2&hash=item5d499f4044


 
  
 so its an octal but different pinout? and whats the top cap in the adapter for?


----------



## gibosi

mab1376 said:


> so its an octal but different pinout? and whats the top cap in the adapter for?


 
  
 Again, I have no experience with this tube, but yes, the pin-out is different and thus, an adapter is needed. The biggest difference is that there is an element, or perhaps one might say, a very fat pin located on top of the tube, which corresponds to grid 1.


----------



## mordy

Hi Artsi,
  
 Here is a colorful idea for your next project. All you need is a WWII jerry can:
  




  
 LOL


----------



## Artsi

mordy said:


> Hi Artsi,
> 
> 
> 
> ...



 


Usually those jerry cans smell like diesel for a long time. But i have plans to do normal stereo tube amplifier with headphone output. It is little bit different to work with output transformers, but we'll see what is going to happen.


----------



## mordy

Hi,
  
 Little quiet on the forum; we need a little action.
  
 Here is a he-man tube, the indomitable 833C: (plz note the size compared to a regular tube)
  
  
  




  




  
 This is a broadcast tube that can generate some serious high voltage; 1200-2000V +
  




  
  
 Here is an application for stereo.
  




  
 However, personally, I think that it is a bigger achievement to get $1000 sound from a $200 amp than to get great sound from an amp costing tens of thousands of $$......


----------



## gibosi

Yes, it has been quiet... So maybe I can stir things up a bit? lol
  
 I have been thinking about whether it might be possible to use a rather different double triode, the E90CC, in our LDs. Users of Torpedo headphone amps
  
 http://beezar.com/catalog/product_info.php?cPath=42&products_id=153
  
 rate the E90CC to be the best tube available for that amp.
  
 However, it has a common cathode, and evidently, there is no way to run it as a double triode in our LDs. When I first looked at this tube, and saw only 7 pins, I wondered how? Each triode typically takes 3 pins and then the heaters take 2 more for 8 pins! But in the E90CC, the two cathodes are tied together. So, this leads me to the idea of converting this double triode into a single triode, that is, finish the job by tying the two grids together and the two plates together in the socket.
  
 Now.... my knowledge of electronics is just sufficient to get me into trouble... but not out of trouble!  lol...
  
 So I will just throw this out and see if folks think this is crazy..
  
 From what I have been able to figure out....  The plate resistance of the E90 is 4.5Kohms. So if we tie the two plates together, I guess the combined plate resistance would be 9.0Kohms? However, the ECC40 has a plate resistance of 9.3Kohms, and it works extremely well in my LD. So it would seem to me that the LD just might be able to handle a E90CC converted into a single triode...
  
 TrollDragon and others.... what do you think?


----------



## TrollDragon

mordy said:


> This is a broadcast tube that can generate some serious high voltage; 1200-2000V +


 
 Here is an 833A DIY amp...
http://world-designs.co.uk/forum/showthread.php?t=5939


----------



## TrollDragon

gibosi said:


> From what I have been able to figure out....  The plate resistance of the E90 is 4.5Kohms. So if we tie the two plates together, I guess the combined plate resistance would be 9.0Kohms? However, the ECC40 has a plate resistance of 9.3Kohms, and it works extremely well in my LD. So it would seem to me that the LD just might be able to handle a E90CC converted into a single triode...
> TrollDragon and others.... what do you think?


 
 Hey gibosi
  
 Paralleling plates is like paralleling resistors the resistance will be half not double, so you will end up with an Rp of 2.25K
  
 The parafeed amp does parallel the plates and the grids but it is designed to do such.

 Sorry I don't know what the LD's minimum Rp value should be and can't say if this tube would be OK or not.


----------



## TrollDragon

I was thinking something along the lines of a 6D10, Compactron with three triodes in it, just ignore the middle triode and make a 12pin to dual 7 pin adapter and the heater is only 0.45A.
 http://www.radiomuseum.org/tubes/tube_6d10.html


----------



## gibosi

trolldragon said:


> Hey gibosi
> 
> Paralleling plates is like paralleling resistors the resistance will be half not double, so you will end up with an Rp of 2.25K
> 
> ...


 
  
 lol... So I got it backwards!
  
 But even so, the 6DJ8 has a plate resistance of about 2.5K, so the E90CC just might be OK...


----------



## i luvmusic 2

I'm wondering what will happen if i switch the jumper from EF95 to EF91/92 setting with 6SN7 Tube.fireworks maybe?


----------



## gibosi

i luvmusic 2 said:


> I'm wondering what will happen if i switch the jumper from EF95 to EF91/92 setting with 6SN7 Tube.fireworks maybe?


 
  
 I do not know what your adapter looks like....  My adapter uses two 7-pin test sockets inserted into the LD. The 6SN7's two triodes are directly connected to pins 1, 2 and 5 on each test socket. As the EF91/92 setting connects pins 6 and 7, which are not used by my mod, nothing would happen.....


----------



## TrollDragon

Like gibosi said, the 7 pin LD sockets have pins 5&6 shorted together permanently on the circuit board. When you move the jumper to EF92 it shorts pin 7 to 5&6.


----------



## i luvmusic 2

gibosi said:


> I do not know what your adapter looks like....  My adapter uses two 7-pin test sockets inserted into the LD. The 6SN7's two triodes are directly connected to pins 1, 2 and 5 on each test socket. As the EF91/92 setting connects pins 6 and 7, which are not used by my mod, nothing would happen.....


 
 OK Thanks no need for me to try switching.


----------



## mab1376

on the 6sn7 tubes, which is the heater positive and negative? is 7 positive or 8?
  
 also how do you adjust the output of the regulator? mine is stuck at 11.6 output and there's a little screw on it but it does nothing.


----------



## Oskari

gibosi said:


> Two Japanese 8FQ7


 
  


mordy said:


> I have three different Japanese 8FQ7/6CG7 tubes.


 
  
 I take it that you have checked the relevant parts of http://www.geocities.jp/radiomann/HomePageVT/TV_GPTT.html.
  
 If not, please do.


----------



## mordy

Hi Oskari,
  
 Thanks - the first time I checked I could not find them, but now I think that I have identified Hitachi and Toshiba tubes, with the nod going to Hitachi.
 The Raytheon/Hitachi 8FQ7 is one of my favorite tubes at this point.


----------



## i luvmusic 2

mab1376 said:


> on the 6sn7 tubes, which is the heater positive and negative? is 7 positive or 8?
> 
> also how do you adjust the output of the regulator? mine is stuck at 11.6 output and there's a little screw on it but it does nothing.


 
 According to Gibosi it does not matter 7 or 8  on mine 8 is +.IMO on your Regulator maybe input and output are reverse or faulty Pot.


----------



## mab1376

The component in red is also a little wobbly.
  
 I probably have to request a replacement and wait another month...


----------



## i luvmusic 2

mab1376 said:


> The component in red is also a little wobbly.
> 
> I probably have to request a replacement and wait another month...


 
 Try resoldering those components or replaced the pot. in my area those pots are less than $1.


----------



## mab1376

i luvmusic 2 said:


> Try resoldering those components or replaced the pot. in my area those pots are less than $1.


 
  
 I found that if i twisted the pot to the left it eventually went down, strangely i can only set 6.19 or 6.35 with no in between?


----------



## gibosi

oskari said:


> I take it that you have checked the relevant parts of http://www.geocities.jp/radiomann/HomePageVT/TV_GPTT.html.


 
  
 Yes, I have checked my tube against the pictures. Unfortunately, tall, flat, ladder plates can be seen on Toshiba and Hitachi, as well as other brands. Further, my tube has a disk getter and one of those mica-spring structures on the top mica, and ferrous grids, not copper. I don't see anything quite like it there....


----------



## gibosi

mab1376 said:


> I found that if i twisted the pot to the left it eventually went down, strangely i can only set 6.19 or 6.35 with no in between?


 
  
 Our cheap voltage regulators, being digital and not analogue, are adjustable in discrete steps. It is not infinitely adjustable and you simply can't adjust it as precisely as you might want. Further, this is somewhat exacerbated by having LED displays with 2 decimal points. My display is only 1 decimal point so these discrete steps are not as noticeable. On the other hand, there is nothing to be gained by setting the voltage to exactly 6.3 volts. Either 6.19 or 6.35 is perfectly OK.


----------



## mab1376

gibosi said:


> Our cheap voltage regulators, being digital and not analogue, are adjustable in discrete steps. It is not infinitely adjustable and you simply can't adjust it as precisely as you might want. Further, this is somewhat exacerbated by having LED displays with 2 decimal points. My display is only 1 decimal point so these discrete steps are not as noticeable. On the other hand, there is nothing to be gained by setting the voltage to exactly 6.3 volts. Either 6.19 or 6.35 is perfectly OK.


 
  
 I used a multimeter on the output for exactly 6.3v which actually reads 6.19v
  
 I would assume to much voltage would shorten the life by increased heat?
  
 Its now dead silent while not playing music!! No background hiss/buzz!
  






 
  
 Got a Tung-Sol JAN-CTL-6SU7GTY running right now!


----------



## gibosi

Glad to hear that everything is working well for you. And yes, it is great to be able to kill two birds with one stone. Now we can roll higher heater current tubes, like 6SN7, E80CC and ECC40, and our amps are quieter! Win-win!!


----------



## gibosi

mab1376 said:


> I used a multimeter on the output for exactly 6.3v which actually reads 6.19v
> 
> I would assume to much voltage would shorten the life by increased heat?


 
  
 Too much voltage will shorten tube life, but not 6.4 or 6.5 volts. If you were running at 7V or 8V, yes.


----------



## mab1376

gibosi said:


> Glad to hear that everything is working well for you. And yes, it is great to be able to kill two birds with one stone. Now we can roll higher heater current tubes, like 6SN7, E80CC and ECC40, and our amps are quieter! Win-win!!


 
  
 I've got a new production Tung-Sol 6SN7GTB I'm listening to right now which also sounds really good based on a few minutes of listening.


----------



## mordy

Hi mab1376 et al,
  
 Re the little voltage regulator, my impression is that the LED readout is stepped; i.e it goes from 6.27V to 6.43V to 6.52V in my case. However, you can turn the little set screw about a quarter of a turn or so without changing the LED readout value, but a multimeter will show the voltage changing in between these readings.
 Therefore, I am able to adjust the voltage to exactly 6.3V using the multimeter with the LED readout still showing 6.19V or 6.27V etc.
  
 My nature is such that I'd rather have it at 6.3V than be content with 6.19V or 6.42V.
  
 Something else I discovered - the voltage can show 6.3V at the regulator output terminals, but read 6.19V at the socket on my breadboard. I have two setups using breadboards; one for 6/8FQ7 and 6DJ8 tubes, and another for 12AX7 and octal tubes (with an adapter). The first setup reads the same voltage at the socket pins as at the voltage regulator, but the second setup reads lower than at the regulator. In order to get 6.3V at the tube socket I need 6.52V at the regulator (don't know why).
  
 I would recommend measuring the voltage at the tube socket just to be sure. I am doing this with everything turned on and a tube in place, being very careful only to touch the correct pin tabs with the test leads. As has been pointed out previously, some pins carry dangerously high voltage, and I mounted the regulator and breadboard on a piece of wood so that I can't touch anything underneath by accident.


----------



## mordy

Re the new Tung Sol tube vs an old one, have you been able to compare them?
  
 From what I read the new production tubes are good, but most people seem to prefer the old ones.
  
 I am coming in without any preconceived ideas, and I am just giving over my listening impressions as honestly as I can.  My goal is to try to find the inexpensive giant killers. So far I have not read much about the Japanese Raytheon 8FQ7 and RCA 6SN7GTB 1965-67 tubes with the thin heater wire above the top mica, but to me these tubes sound fabulous.
  
 At this time these tubes can be found for less than $5.00 if you shop carefully. Would like to hear from others who tried these tubes.


----------



## mab1376

mordy said:


> Re the new Tung Sol tube vs an old one, have you been able to compare them?
> 
> From what I read the new production tubes are good, but most people seem to prefer the old ones.
> 
> ...


 
  
 The new production sounds much brighter whereas the older ones sound sweet and more balanced. I very much like the new ones from the few minutes i have comparing them, I could easily recommend them as a cheap starter tube I also have a Sylvania 6SL7WGT from 1955 which sounds similar to the old Tung Sol but has a much larger sound stage to me.
  
 This whole vast new world of tubes is already becoming overwhelming lol


----------



## TrollDragon

mordy said:


> In order to get 6.3V at the tube socket I need 6.52V at the regulator (don't know why).


 
  
 That is very strange mordy,
  
 Are you still using solid core wire to connect everything? It really sounds to me like there is a resistor in series with the heater wiring. The short distance the wire travels from your power board to your breakout board would have a very minute effect on the voltage, but you are almost loosing 1/2 a volt.
  
 If you want to try something take a piece of Lamp Cord (Zip Cord we call it) or something similar and use it to wire up your filaments.
 Then check your voltage at both ends and see if there is any drop. If there is a difference unhook the wires connected to the breakout board's filament pins and measure the voltage at the end of the unconnected wire. (Keep your amp powered off for that test.)


----------



## mab1376

How difficult would it be to put a switch on the output of the regulator to turn it on and off?


----------



## gibosi

Yesterday, received an ECC40, manufactured in February, 1952. However I am not at all sure about the factory. The production code appears to be LCC 5S, and if the first character in the second picture is actually a "5", this would indicate Toshiba, Japan. But if so, this would imply that Philips production equipment was installed into a Japanese factory by 1952 and that factory was using Philips production codes. Silk-screening on the tube indicates Holland manufacture, but we know from past experience that we can't necessary believe this. I do not know what to think....
  
 However, regardless of where this tube was manufactured, it sounds great!


----------



## Oskari

gibosi said:


> Yesterday, received an ECC40, manufactured in February, 1952. However I am not at all sure about the factory. The production code appears to be LCC 5S, and if the first character in the second picture is actually a "5", this would indicate Toshiba, Japan. But if so, this would imply that Philips production equipment was installed into a Japanese factory by 1952 and that factory was using Philips production codes. Silk-screening on the tube indicates Holland manufacture, but we know from past experience that we can't necessary believe this. I do not know what to think....


 
  
 I think the code was originally used by some Philips department in Eindhoven, later for Toshiba-made tubes.


----------



## mab1376

I just picked up a smoked glass RCA 12SN7, the 6SN7 version goes for about $40 on ebay and i got the 12v version for $5 
  
 Yay for mods!


----------



## gibosi

oskari said:


> I think the code was originally used by some Philips department in Eindhoven, later for Toshiba-made tubes.


 
  
 Thanks! Eindhoven certainly seems to make more sense than Toshiba for this tube.


----------



## samtheman

mab1376 said:


> I just picked up a smoked glass RCA 12SN7, the 6SN7 version goes for about $40 on ebay and i got the 12v version for $5
> 
> Yay for mods!


 

 Please excuse my naivety but I have to ask a potentialt silly question. To use a 12sn7 with a custom Octal adapter with external step-down power supply on a LD MKiii, is it as simple as turning up the power supply to 12volts?


----------



## mab1376

samtheman said:


> Please excuse my naivety but I have to ask a potentialt silly question. To use a 12sn7 with a custom Octal adapter with external step-down power supply on a LD MKiii, is it as simple as turning up the power supply to 12volts?


 
  
 yup just increase the pot on the trimmer board to 12v output, as long as your PSU supports 12v at 600ma that's the only thing you need to do.
  
 I'm currently using the power adapter from a Nintendo Wii that i recently threw out since it was broken. I'd like to find something with an on/off switch though.


----------



## gibosi

mab1376 said:


> yup just increase the pot on the trimmer board to 12v output, as long as your PSU supports 12v at 600ma that's the only thing you need to do.
> 
> I'm currently using the power adapter from a Nintendo Wii that i recently threw out since it was broken. I'd like to find something with an on/off switch though.


 
  
 An on/off switch would be great. But in the meantime, I simply plug the LD and the adapter into a separate surge protector power bar and use that to turn both on and off. In this way, I don't have to worry about inadvertently leaving the heaters on when I turn the LD off.
  
 Oh, while 6SN7s require 600ma, if you double the voltage to 12.6V, the amperage requirement drops by half to 300ma.


----------



## samtheman

That's good to hear - just waiting on my Step-down converter to arrive in the post. The wait is making me crazy. Everything else for the adapter is built.
  
 I have just dug-up another power adapter with an output rated as 6v at 600ma. Would this do the job for 6SN7 tubes while I wait for the converter? Does 6volts vs 6.3 volts make a big difference?


----------



## mordy

Hi samtheman,
  
 6V won't do the trick. The voltage regulator works in such a way that what comes out is around 2V lower than what goes in. In order to get 6V out you need at least an 8V adapter. To be able to use the voltage regulator for a variety of tubes from 6V - 12V it is best to get an adapter capable of at least 15V.


----------



## samtheman

I was thinking of bypassing the regulator (as I don't have it yet) altogether and powering the 6SN7 tube directly with the 6v 600ma power adapter?


----------



## mordy

Hi mab1376,
  
 Since i use a receiver, I just plug the voltage regulator adapter into a switched outlet on the back of the receiver. When the receiver is on, the heater is on, and when I shut it off, it's off.
  
 However, I don't see any problem inserting a little push button or similar on off switch in one of the leads from the adapter (many times lamp cords have these little switches for table lights).


----------



## mab1376

mordy said:


> Hi mab1376,
> 
> Since i use a receiver, I just plug the voltage regulator adapter into a switched outlet on the back of the receiver. When the receiver is on, the heater is on, and when I shut it off, it's off.
> 
> However, I don't see any problem inserting a little push button or similar on off switch in one of the leads from the adapter (many times lamp cords have these little switches for table lights).


 
  
 I'm sure i can find something, I can probably scrounge up one at work since I work in an electronics factory. Right now I just have a Wii PSU plugged into my UPS.
  


samtheman said:


> I was thinking of bypassing the regulator (as I don't have it yet) altogether and powering the 6SN7 tube directly with the 6v 600ma power adapter?


 
  
 As long as that's whats being outputted it should work. Spec is technically 6.3v but 6.0v will probably work fine.
  
 http://www.alibaba.com/product-detail/6-3v-600ma-dc-adapter_487037164.html


----------



## samtheman

mab1376 said:


> I'm sure i can find something, I can probably scrounge up one at work since I work in an electronics factory. Right now I just have a Wii PSU plugged into my UPS.
> 
> 
> As long as that's whats being outputted it should work. Spec is technically 6.3v but 6.0v will probably work fine.
> ...


 

 Thanks for the advice. Just tried it and its working 
  Will post impressions once I've had a chance to have a proper listen.


----------



## gibosi

samtheman said:


> I was thinking of bypassing the regulator (as I don't have it yet) altogether and powering the 6SN7 tube directly with the 6v 600ma power adapter?


 
  
 It would be a good idea to check the output of this adapter with a voltmeter. I have a 24V adapter that is actually putting out 33V! So your 6V adapter might be putting out more than 6V. If is is less than 7V, then I think you can get by for awhile. But if it is more than 7V, it mght be better to wait...


----------



## i luvmusic 2

Good point let me measure mine...


----------



## samtheman

gibosi said:


> It would be a good idea to check the output of this adapter with a voltmeter. I have a 24V adapter that is actually putting out 33V! So your 6V adapter might be putting out more than 6V. If is is less than 7V, then I think you can get by for awhile. But if it is more than 7V, it mght be better to wait...


 

  Gibosi - you are a legend! Always so helpful and wise.
  
 The power adapter is one where you can select the output voltage - 5,6,7 etc. I checked the 6V setting with a Multimeter and just as you warned it was indeed outputting a high voltage (7.5 Volts). Just for interest's sake I selected 5volts and checked again. What would you know - the actual reading on the multimeter came out as 6.3 Volts exactly  I'm going to stick with the 5 volt setting until the step-down converter arrives.
  
 Thank you so much Gibosi and everyone else who has been advising me. It's helpful people like you all who re-new my faith in Humanity


----------



## i luvmusic 2

I just measured mine(24V) SPERRY Meter readout is 24.82V and IDEAL meter readout is 23.97V on the output side it read 6.39V on board LED Display but on my IDEAL Meter it read 6.34V.


----------



## mab1376

samtheman said:


> Gibosi - you are a legend! Always so helpful and wise.
> 
> The power adapter is one where you can select the output voltage - 5,6,7 etc. I checked the 6V setting with a Multimeter and just as you warned it was indeed outputting a high voltage (7.5 Volts). Just for interest's sake I selected 5volts and checked again. What would you know - the actual reading on the multimeter came out as 6.3 Volts exactly  I'm going to stick with the 5 volt setting until the step-down converter arrives.
> 
> Thank you so much Gibosi and everyone else who has been advising me. It's helpful people like you all who re-new my faith in Humanity


 
  
 Good catch Gibosi!


----------



## TrollDragon

samtheman said:


> The power adapter is one where you can select the output voltage - 5,6,7 etc. I checked the 6V setting with a Multimeter and just as you warned it was indeed outputting a high voltage (7.5 Volts). Just for interest's sake I selected 5volts and checked again. What would you know - the actual reading on the multimeter came out as 6.3 Volts exactly  I'm going to stick with the 5 volt setting until the step-down converter arrives.


You need to measure the voltage under load for a proper reading, You will probably find on most non switching unregulated power supplies / adapters that measuring voltage without a load will give higher readings than advertised since the minimal regulation circuitry requires a load to work.

Test it again with the 6V setting connected to a tube filament.


----------



## gibosi

trolldragon said:


> You need to measure the voltage under load for a proper reading, You will probably find on most non switching unregulated power supplies / adapters that measuring voltage without a load will give higher readings than advertised since the minimal regulation circuitry requires a load to work.
> 
> Test it again with the 6V setting connected to a tube filament.


 
  
 I have a question. Measuring my 24V adapter at the input to the voltage regulator shows 33V with no load. But still, I am able to dial in more than 25V. So, it certainly seems that my 24V adapter is actually putting out more than 24V into a load. But perhaps, since its intended use is as a battery charger for an 19.2V drill/driver, the load presented by a tube is somewhat different than it was spec'd for?  And perhaps this explains to some degree why it is delivering more than it's rated voltage?


----------



## TrollDragon

gibosi said:


> I have a question. Measuring my 24V adapter at the input to the voltage regulator shows 33V with no load. But still, I am able to dial in more than 25V. So, it certainly seems that my 24V adapter is actually putting out more than 24V into a load. But perhaps, since its intended use is as a battery charger for an 19.2V drill/driver, the load presented by a tube is somewhat different than it was spec'd for?  And perhaps this explains to some degree why it is delivering more than it's rated voltage?


 
 NiCad batteries require a constant current for charging, the voltage has to be higher than the battery voltage to allow this to happen. If you plugged in a battery pack and measured the voltage from the charger you will find it to be between 19.2 and 24V depending on the charge state of the batteries.
  
 You are able to dial in more than 25V as the no load output of the charger is 33V and the current draw from the regulator / tube is minimal compared to charging a battery.


----------



## gibosi

Thanks for clarifying this. It all makes sense.


----------



## samtheman

trolldragon said:


> You need to measure the voltage under load for a proper reading, You will probably find on most non switching unregulated power supplies / adapters that measuring voltage without a load will give higher readings than advertised since the minimal regulation circuitry requires a load to work.
> 
> Test it again with the 6V setting connected to a tube filament.


 

 Thank you - great advice.
  
 Power supply was connected to the tube when I tested it - more by luck than design though


----------



## TrollDragon

samtheman said:


> Thank you - great advice.
> 
> Power supply was connected to the tube when I tested it - more by luck than design though


You are most welcome.

I couldn't tell by your post if it was connected or not, since it is under load that you get 6.3V on the 5V setting then that is good and will work great until your reglulator arrives on the slow boat from China.


----------



## samtheman

trolldragon said:


> You are most welcome.
> 
> I couldn't tell by your post if it was connected or not, since it is under load that you get 6.3V on the 5V setting then that is good and will work great until your reglulator arrives on the slow boat from China.


 

 Yes - that boat from China is certainly a slow one 
  
 By the way - would you recommend using the regulator when it arrives instead of the power supply I have now? I'm just wondering if the regulator is better? The power supply I'm using now is a switching power supply - if that makes a difference.
  
 Thanks again.


----------



## i luvmusic 2

Hi TD,is it possible to run 2 regulator from one Power Supply(24V-5A PS)?I will be using one regulator for 6.3V and one regulator for 12V from one PS and i will put a ON(6.3V) OFF ON(12)switch i think these way i don't need to dial in the voltage regulator all the time.And can i run both regulator at the sametime if i need to.


----------



## TrollDragon

samtheman said:


> Yes - that boat from China is certainly a slow one
> 
> By the way - would you recommend using the regulator when it arrives instead of the power supply I have now? I'm just wondering if the regulator is better? The power supply I'm using now is a switching power supply - if that makes a difference.
> 
> Thanks again.


 

 Since the power supply you have now is a switching variety and is providing adequate voltage and current to run the 6V tubes, then I see no reason to change it out for the regulator. If you are looking to run 12V tubes the regulator would come in handy with at least a 15V source supply.
  
 Whatever works and is the easiest to use is what I like.


----------



## TrollDragon

i luvmusic 2 said:


> Hi TD,is it possible to run 2 regulator from one Power Supply(24V-5A PS)?I will be using one regulator for 6.3V and one regulator for 12V from one PS and i will put a ON(6.3V) OFF ON(12)switch i think these way i don't need to dial in the voltage regulator all the time.And can i run both regulator at the sametime if i need to.


 

 I don't see any problem in running both regulators from the power supply and the switch is a handy feature to flip between them. I'd just use two SPST switches, one for 6V and the other for 12V instead of the Center Off switch, it would be easier to use both at the same time that way.


----------



## i luvmusic 2

trolldragon said:


> I don't see any problem in running both regulators from the power supply and the switch is a handy feature to flip between them. I'd just use two SPST switches, one for 6V and the other for 12V instead of the Center Off switch, it would be easier to use both at the same time that way.


 
 THANK YOU!


----------



## samtheman

trolldragon said:


> Since the power supply you have now is a switching variety and is providing adequate voltage and current to run the 6V tubes, then I see no reason to change it out for the regulator. If you are looking to run 12V tubes the regulator would come in handy with at least a 15V source supply.
> 
> Whatever works and is the easiest to use is what I like.


 

 Gracias Senor! Simple is best.


----------



## i luvmusic 2

I don't know why i'am reading these thread backwards...


----------



## i luvmusic 2

Page 300 that's where my 6SL7/6SN7 journey began did not look back ever since.THANKS GUYS!


----------



## gibosi

Received some nice tubes here recently....
  
 A pair of FIVRE 6SN7GT. I got these for a pretty good price as they are not quite a "matched" pair. Notice that the tube on the right has a side getter and the tube on the left, a bottom getter, but otherwise, they appear identical. In a quick search on Google, I wasn't able to find anything to help me date these tubes. An obvious guess is that the "7" and "6" might represent the last digit of the year, so perhaps, the 1940's or 1950's, or even 1960's?
  
 Spent an hour or so last night with the left tube and it sounded very good to me. Borrowing from Mordy, this is very musical and toe-tapping tube and there was nothing in the sound to distract me. That is, I found myself listening to the music, and not the tube. One album in particular, Don't Explain (Beth Hart and Joe Bonamassa), stood out. Hart's vocals are very raw and powerful on this album, and with some tubes, her voice can be a bit shrill and harsh, but with the FIVRE, everything was good.
  

 .
 And a Dario branded ECC40, manufactured in Philips' Sittard, Holland. factory in January, 1953 (LCC +t). Note that as Dario is a French brand, a Holland-made tube is labeIed "FOREIGN". Haven't had a chance to listen to this tube, but am very relieved to be able say that it lights up and plays. One thing that is immediately noticeable when powering up these Philips ECC40s is they exhibit a bright flash of light similar to the 6HM5.


----------



## Oskari

gibosi said:


> .
> And a Dario branded ECC40, manufactured in Philips' Sittard, Holland. factory in January, 1953 (LCC +t). Note that as Dario is a French brand, a Holland-made tube is labeIed "FOREIGN".


 
  
 This is quite interesting. It seems to me that the tube was packaged for the UK market. Sure enough, radiomuseum.org has a (very short) listing for Dario-Impex, GB:
  

http://www.radiomuseum.org/dsp_hersteller_detail.cfm?company_id=6975
  
 If you can manage the German, the last message here by Jacob Roschy is especially enlightening:
  

http://www.radiomuseum.org/forum/dario_roehren_typen_daten.html
  
 Google translation:


> In the book "History of the British Radio Valve to 1940," writes KR Thrower on Dario-Impex (UK): "Selling Philips tubes French production"; Address: Impex Electrical Ltd, 538 High St., London, E11 and 47 Victoria Street, London, SW1..
> The name Impex deuted already on imports and exports. Again, this is another example of how Philips disguised its huge market share and the buyers pretending alternatives. Philips was strongly represented in the UK already under his own name and with Mullard.


 
  
 Perhaps Stavros might be able to tell you something about the FIVREs.


----------



## gibosi

Coincidentally, I purchased this Dario from a UK-based vendor.


----------



## Nic Rhodes

Keith's books are excellent


----------



## mordy

Hi i luvemusic 2,
  
 After you set up both power supplies I would just re-measure the voltage at the tube socket pins to make sure that nothing changes.
  
 Personally, I have a different type of setup with two differently wired breadboards attached to one voltage regulator. I just have to make sure that only one tube is plugged in at any one time. To switch from 6DJ8 to octal tubes I just unplug the Vector adapters and switch to a second set of Vectors, making sure that the voltage is set correctly.
  
 (I tried having one Vector plugged into the other, i.e one on top the other, hoping that I would only need to switch the tube and the voltage, but that did not work at all. In retrospect, I should have figured out that that it is a dumb idea to mix two different wiring schemes.)
  
 Anyhow, waiting for an upgraded 5A voltage regulator for them power hungry 6SN7 variants...
  
 There are custom made Bugatti Weyron level systems out there costing mega bucks:
  

VPI Scout turntable + Shelter 501 MkII cartridge
Krell KPS 20i/L cd player
Gryphon XT MC preamplifier
Mandozzi DART harddiskrecorder
Nagra ARES harddiskrecorder
Self build power amplifiers using 6SN7 - 300B - TB3/1000. These are on the outside of the audio rack. The dedicated power supplies are below; the amplifiers themselves are above
Self build tube headphone amplifier using 6SN7's. It is in the middle lower shelf. The dedicated power supply is next to it. It drives a Grado RS1.
Self build Avalon Opus Ceramic loudspeakers with external crossovers.
 The power amplifiers deliver 70 Watt single ended Class A. The output triodes are pre-WWII transmitting triodes from Philips. The American equivalent is the well known 833A. These triodes are fired through a step down interstage using EML 300B's. I have the 300B-XLS and the 300B-Mesh. And it is a matter of taste what to choose; both perform excellent !. The 300B-driver is essential in these amplifiers for the output triodes want to see a very stable driver.
 The amplifiers are fully hard-wired. All needed voltages do have there own power line consisting of power transformer - rectifier - snubber - coil - capacitor - coil - capacitor. This adds up to a total of 32 coils and transformers. And as these amplifiers run on 1200 Volt everything is quite large. The complete amplifier weighs more than 300 kgs.
  




  
 This guy claims that the listening experience is better than listening live in a concert hall.
  
 Why I am showing this? Because we have something in common - he is using 6SN7 tubes as drivers. I think we are on to something...


----------



## mab1376

Anyone ever try any 5961 tubes?
  
 http://www.cryoset.com/catalog/product_info.php?cPath=71&products_id=270&osCsid=19f2617a255156356120b77c56188f42


----------



## gibosi

mab1376 said:


> Anyone ever try and 5961 tubes?
> 
> http://www.cryoset.com/catalog/product_info.php?cPath=71&products_id=270&osCsid=19f2617a255156356120b77c56188f42


 
  
 The 5961 is a premium, long-life, high-reliability, industrial version of the 6SL7, and while a little different, they are plug-compatible in our LDs, providing you have an external heater PS, as they require 600ma as opposed to 300ma for the standard 6SL7.
  
 http://www.r-type.org/pdfs/5691.pdf
  
 However, I have never tried one....


----------



## Nic Rhodes

5691 (6sl7gt) and 5692 (6sn7gt) are premium long life tubes. Rated for 10000 hrs they probably achieve this but under rating the standard tube (hence spec differences) but these tubes are well built with extras supports etc. Originally in the famed red bases, these tubes are highly sort after by audiophiles, especially in Japan after the Roberts Sound Practices article. There were however brown based examples (like CBS / Hytron) in the mid 1950s and later Sylvania / PhilipsECG black based versions 70s / 80s also (as linked to above). All are excellent tubes but I like the brown based ones best and these are still good value for a 5691 / 5692. The balck base 5691 are cheap compared to the red based versions. The 5691 / 5692 are tough little tubes built with massive excess, second only to Bendix. Be careful in purchasing these tubes however as many people try to re label / palm off standard tubes as 5691 / 5692s. These are easily spotted if you know what to look for (5 heavy duty support rods), I have 10 National 5692 from Russia that are...... , well not the same as the US ones!


----------



## i luvmusic 2

mordy said:


> Hi i luvemusic 2,
> 
> After you set up both power supplies I would just re-measure the voltage at the tube socket pins to make sure that nothing changes.
> 
> ...


 
 Hi Mordy,
       My setup is only for 6SL7/6SN7 and for 12 volt version. my plan is to use  2 regulators(one is set to 6.3V and the other is  set to12V) and some switches to select from 6V and 12V and from LD 1 to LD MK III or play/used both amps if i want to, once i'am done with these configuration i will take a picture.I want to do it this way because lately i got soo lazy adjusting/reconfigure my setup just to play from LD 1 to LD MK III And hopefully my parts will arrived soon i ordered it 2 weeks ago and i'am still waiting for that SLOW BOAT FRON CHINADA.Those amps on the picture are really nice and THANK YOU for your advised.


----------



## hypnos1

Hi guys - wonder if anyone can put me straight on my search for some nice "coke-bottle" power tubes, better to match (_almost _visually anyway!) my C3gSs.
 Am I way off here, please - viz 6C4C (6B4G/6A3) tubes? 6.3v/900mA - but DIRECTLY heated...would love to hear any opinions/info...
  
 Cheers.


----------



## gibosi

hypnos1 said:


> Hi guys - wonder if anyone can put me straight on my search for some nice "coke-bottle" power tubes, better to match (_almost _visually anyway!) my C3gSs.
> Am I way off here, please - viz 6C4C (6B4G/6A3) tubes? 6.3v/900mA - but DIRECTLY heated...would love to hear any opinions/info...


 
  
 I hope someone with more expertise will weigh in, but I have no idea what sort of modifications would be necessary to run directly heated cathodes in our Little Dots... But of course, I am hoping that there is a way.


----------



## i luvmusic 2

What is the average price you guys paid for 6SN7? i've been looking around and the lowest i found is $20 + shipping (which is some seller will charged arm and a leg)Thanks!


----------



## gibosi

i luvmusic 2 said:


> What is the average price you guys paid for 6SN7? i've been looking around and the lowest i found is $20 + shipping (which is some seller will charged arm and a leg)Thanks!


 
  
 I'm not sure where you are looking, but I see lots of 6SN7s for less than $20. For example, here is a nice Sylvania "Chrome Dome", relabeled as a Raytheon, for $8.50 plus $3.75 shipping within the US. (However, I know that shipping from the US to Canada would be more than $3.75).
  
 http://www.ebay.com/itm/1-RAYTHEON-6SN7GTA-Radio-Vacuum-TUBE-Tested-audio-amplifier-Sylvania-/351014736002?pt=Vintage_Electronics_R2&hash=item51ba1bd082
  
 One suggestion, when using eBay, go to the left-hand side and click "Worldwide" under "Item Location", and then search for "6SN7". This will give you the largest selection.
  
 Of course, if you are searching for tubes that are well-known and in-demand, you might have to pay more. But even then, if you are familiar with the unique construction details of the tube you hope to buy, looking for rebranded tubes can often reward you with significant savings. For example, if you wanted a Sylvania "Chrome Dome", you could purchase the Raytheon linked to above, for cheap.
  
 Good luck!


----------



## MIKELAP

gibosi said:


> I'm not sure where you are looking, but I see lots of 6SN7s for less than $20. For example, here is a nice Sylvania "Chrome Dome", relabeled as a Raytheon, for $8.50 plus $3.75 shipping within the US. (However, I know that shipping from the US to Canada would be more than $3.75).
> 
> http://www.ebay.com/itm/1-RAYTHEON-6SN7GTA-Radio-Vacuum-TUBE-Tested-audio-amplifier-Sylvania-/351014736002?pt=Vintage_Electronics_R2&hash=item51ba1bd082
> 
> ...


 
 Yup to Montreal  $18.48 U.S. shipping for a $8.50 tube incredible !


----------



## gibosi

mikelap said:


> Yup to Montreal  $18.48 U.S. shipping for a $8.50 tube incredible !


 
  
 Yes, those of us in the US are very spoiled. I can send a tube from Ohio to California for $2 or $3, with tracking, and it will get there in 2 or 3 days. If I were to send the same package to you in Montreal, it would be around $10, with no tracking, and it would take 10 days to 2 weeks! I find this to be amazing! (>_<)


----------



## mab1376

I found a smoked glass RCA 12SN7 for $8 on ebay last week that I bought.
  
 http://www.ebay.com/itm/151210735886?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649
  
 12SN7 are less popular therefore much cheaper, just gotta make sure you have a sufficient external PSU.


----------



## mordy

Hi i luvmusic 2,
  
 I recently bought a lot of 10 6SN7 tubes for $26 including shipping. Read somewhere (jacmusic?) that he opened a factory sealed box of 50 tubes and found JAN, VT, GT and GTW tubes in the box. Apparently, all the tubes were the same, but they were marked differently.
  
 For this reason I don't pay so much attention to what it says on the tube, and as they say, the proof is in the pudding; I'll listen to them and make my own evaluation. There is no doubt in my mind that certain sellers have hyped certain items for profit making reasons. I somebody paid $99 for a tube it better sound stupendous!
  
 In this lot of ten I lucked out; there were five winners. I got a Japanese tube, a genuine Sylvania Chrome Dome (not Chrome Top), two late model RCAs and a an earlier RCA that all sound excellent. So I paid $2.60 each, or if I discard the me too's, the cost was $5.20 each incl shipping.
  
 If you look at the left column on Ebay of 6SN7 listings (or whatever) you will find a check box that says sold listings. When you check it you will see what the items actually sold for. Usually, but not always, there will be desirable tubes that sold very cheap. This overview gives you an idea what to pay and how much you should bid. If there is a best offer feature, don't hesitate to make a shamelessly low offer. A decent seller will not ignore you, but come up with a counter offer. Sometimes it's ridiculous, and sometimes reasonable. Or they may bite on your original offer...
  
 What you a are looking for are the non professional sellers that are selling off what they picked up at an estate sale or inherited from an old uncle. Don't forget that the 99c tube somebody is selling is the same as someone else is asking $29.99 for.
  
 Scroll down this list to see what 6SN7 tubes sold for the last couple of months:
 http://www.ebay.com/sch/Vintage-Electronics-/14998/i.html?_from=R40&_sop=15&_nkw=6sn7&LH_Complete=1&LH_Sold=1&rt=nc
  
 Now, type in 6SN7 and click on lowest price incl shipping from the drop down menu on the right:
 http://www.ebay.com/sch/Vintage-Electronics-/14998/i.html?_from=R40&_sop=15&_nkw=6sn7&rt=nc
  
 I counted a dozen auctions starting on under $1 (don't know where the price will end), and four Buy It Now tubes for less than $6 incl shipping within the US
  
 Unfortunately, shipping to Canada is a bummer...
  
 Now I have given away my buying secrets....
  
 PS: Don't forget to check the feedback score. Anything under 99% I would be leery of. You can actually go in and read the negative feedback to see what the problem is - sometimes it is trivial.


----------



## Artsi

hypnos1 said:


> Hi guys - wonder if anyone can put me straight on my search for some nice "coke-bottle" power tubes, better to match (_almost _visually anyway!) my C3gSs.
> Am I way off here, please - viz 6C4C (6B4G/6A3) tubes? 6.3v/900mA - but DIRECTLY heated...would love to hear any opinions/info...
> 
> Cheers.


 
 Those directly heated could be very very difficult to get work with LD. I could suggest next tubes:
http://www.radiomuseum.org/tubes/tube_6j5g.html Half of the 6SN7, so you need 4 tubes to replace two 6N6P.
http://www.radiomuseum.org/tubes/tube_6f8g.html Like 6SN7, but needs different adapter
http://www.radiomuseum.org/tubes/tube_ecc32.html This could be the best candidate.


----------



## mab1376

artsi said:


> Those directly heated could be very very difficult to get work with LD. I could suggest next tubes:
> http://www.radiomuseum.org/tubes/tube_6j5g.html Half of the 6SN7, so you need 4 tubes to replace two 6N6P.
> http://www.radiomuseum.org/tubes/tube_6f8g.html Like 6SN7, but needs different adapter
> http://www.radiomuseum.org/tubes/tube_ecc32.html This could be the best candidate.


 
  
 I've been considering trying the 6F8G (VT-99) if i can find an affordable one, especially since i'll need to buy an adapter.


----------



## hypnos1

artsi said:


> Those directly heated could be very very difficult to get work with LD. I could suggest next tubes:
> http://www.radiomuseum.org/tubes/tube_6j5g.html Half of the 6SN7, so you need 4 tubes to replace two 6N6P.
> http://www.radiomuseum.org/tubes/tube_6f8g.html Like 6SN7, but needs different adapter
> http://www.radiomuseum.org/tubes/tube_ecc32.html This could be the best candidate.


 
  
 Many thanks Artsi (and everyone else!) for not calling me mad/sad/stupid (as _I_ did the moment I posted that shot-in-the-dark!). Suppose I was hoping against hope there would be _some_ way of using direct-heated tubes....ah well...
  
 Re.your best candidate - wish I could afford them!! I have in fact been browsing a cv181 substitute - a rather nice-looking Sophia '6SN7', which actually looks nothing like a 6SN7!. But even these are not cheap...WHY did I pay so much for the 6N30P-DRs??? These Sophias would _look_ SO much better...and probably sound just as good, if not better? (Mind you, of course, we had no idea we would end up in such tube territory many months ago, lol!).
  
 But who knows - Santa Claus just _might_ come early...
  


gibosi said:


> I hope someone with more expertise will weigh in, but I have no idea what sort of modifications would be necessary to run directly heated cathodes in our Little Dots... But of course, I am hoping that there is a way.


 
  
 Yes g, so was I hoping...but alas _against_ hope it would appear!
  Never mind, at least Artsi has come up with some possible alternatives...to spend or not to spend?, that is the question...


----------



## TrollDragon

Those Tennis Ball CV181's look amazing.

  
 These don't look too bad either, but not as nice.


----------



## Oskari

Don't be fooled by marketing, guys. The tubes look purdy, but they are CV181s in name only.


----------



## Nic Rhodes

yes agree totally, chinese 6SN7GT in different clothes (but premium chinese 6SN7GTs) but a long long way from a proper CV181.


----------



## Oskari

Markedly so. The ECC32/CV181 is not a 6SN7GT, et vice versa.


----------



## rosgr63

I agree with Nic and Oskari, the Chinese CV181 have the same spec as 6SN7, which is not the same as the ECC32/CV181.


----------



## hypnos1

oskari said:


> Markedly so. The ECC32/CV181 is not a 6SN7GT, et vice versa.


 
  
  


rosgr63 said:


> I agree with Nic and Oskari, the Chinese CV181 have the same spec as 6SN7, which is not the same as the ECC32/CV181.


 
  
 Hi guys. Yo...a '6SN7' that isn't, and a 'CV181' that isn't - all sent to confuse us (yet again!). However, the Shuguang 'Treasure' series CV181-Z certainly has had some very good reviews in the past, and does look to be a VERY beautifully made tube. Wonder if this might make a nice replacement for the 6H30P/6N30P-DR (would certainly look MUCH better behind the C3GSs - but what about _sound_?).
 Would love any feedback from people with first/second-hand experience of these tubes...


----------



## mab1376

hypnos1 said:


> Hi guys. Yo...a '6SN7' that isn't, and a 'CV181' that isn't - all sent to confuse us (yet again!). However, the Shoguang 'Treasure' series C181-Z certainly has had some very good reviews in the past, and does look to be a VERY beautifully made tube. Wonder if this might make a nice replacement for the 6H30P/6N30P-DR (would certainly look MUCH better behind the C3GSs - but what about _sound_?).
> Would love any feedback from people with first/second-hand experience of these tubes...


 
 Interesting: Typical *6SN7* heaters draw about *0.6A* and the *CV181z* draws about *0.9A (900mA)*
  
*Not sure if the LD can handle that since the typical 6n6p types only draw about 750ma.*
  
 http://www.tnt-audio.com/accessories/shuguang_treasures_cv181_e.html


----------



## TrollDragon

mab1376 said:


> Interesting: Typical *6SN7* heaters draw about *0.6A* and the *CV181z* draws about *0.9A (900mA)*
> 
> *Not sure if the LD can handle that since the typical 6n6p types only draw about 750ma.*
> 
> http://www.tnt-audio.com/accessories/shuguang_treasures_cv181_e.html


 
 You get 6.8V @ 2.5A filament current for the power tubes, or so the label says on my MK IV transformer.


----------



## i luvmusic 2

Thanks Guys for all the Tips/suggestions and those Links.Again THANK YOU!


----------



## hypnos1

mab1376 said:


> Interesting: Typical *6SN7* heaters draw about *0.6A* and the *CV181z* draws about *0.9A (900mA)*
> 
> *Not sure if the LD can handle that since the typical 6n6p types only draw about 750ma.*
> 
> http://www.tnt-audio.com/accessories/shuguang_treasures_cv181_e.html


 
  
  


trolldragon said:


> You get 6.8V @ 2.5A filament current for the power tubes, or so the label says on my MK IV transformer.


 
  
 Yep...the 6N30P-DRs draw up to 900mA, and I haven't had any problems at all with 'em. So the Shuguangs would be fine - in that respect at least...I' m REALLY tempted!


----------



## mab1376

hypnos1 said:


> Yep...the 6N30P-DRs draw up to 900mA, and I haven't had any problems at all with 'em. So the Shuguangs would be fine - in that respect at least...I' m REALLY tempted!


 
  
 I'm sure you could always sell the one of the two you don't like, go for it!


----------



## TrollDragon

Here is a nice pair of ECC803S (12AX7) still sealed in the Telefunken Boxes.

 http://www.ebay.co.uk/itm/Pair-of-Telefunken-ECC803S-NOS-NIB-SEALED-12AX7-ECC83-/221372383074


----------



## MIKELAP

trolldragon said:


> Here is a nice pair of ECC803S (12AX7) still sealed in the Telefunken Boxes.
> 
> http://www.ebay.co.uk/itm/Pair-of-Telefunken-ECC803S-NOS-NIB-SEALED-12AX7-ECC83-/221372383074


 
 Holy s....t  Batman !


----------



## mordy

Hi TD,
  
 What's $2200 for a pair of tubes?
  
 Here is a pair of Western Electric 300 B tubes that sold for $13,099.00 + shipping less than a month ago:
  





  
 http://www.ebay.com/itm/Western-Electric-Engraved-Base-300B-Vacuum-Tube-matched-NIB-Pair-/251440711321?pt=Vintage_Electronics_R2&hash=item3a8b08c699&nma=true&si=niP8zVCLHLuw0mJaJfN5L2UzD9g%253D&orig_cvip=true&rt=nc&_trksid=p2047675.l2557


----------



## TrollDragon

mordy that's just Krazy...
  
 We can use the ECC803S though, you'd be some hard pressed to put a 300B into play.


----------



## rosgr63

mab1376 said:


> Interesting: Typical *6SN7* heaters draw about *0.6A* and the *CV181z* draws about *0.9A (900mA)*
> 
> *Not sure if the LD can handle that since the typical 6n6p types only draw about 750ma.*
> 
> http://www.tnt-audio.com/accessories/shuguang_treasures_cv181_e.html


 
  
  
 Actually the CV181Z has the same heater requirement as a 6SN7, 0.6A  at 6.3V.
 The original CV181 draws 0.9A at 6,3V which makes it different to the 6SN7 which means that some amps designed for the 6SN7 may not be able to handle it.
  
 http://grantfidelity.com/site/files/shuguang%20treasure%20tube%20spec%20cv-181.pdf
  
 Shuguang Treasure Series Tube Specification: 
 Model Number: CV-181Z Distributed by: www.grantfidelity.com
 Filament Heating: 
 UH 6.3 V
 IH 0.6 A


----------



## hypnos1

mab1376 said:


> I'm sure you could always sell the one of the two you don't like, go for it!


 
  
 Hey mab, Mephistopheles rides again! How can you tempt a poor fellow so?...How could I possibly part with the DRs? (Mind you, I do have a spare pair - unfortunately one has no writing on it, so had to take it on trust...will probably move them on...).
 So it looks like it's adapter-making time once again - 'She who must be obeyed' thought all was just about wrapped up. As did I!! At least those nice fat pins will be much easier to work with than the C3gs'...
 Ah well, I can always blame you, mon ami (not that I take much persuasion - they look SO beautiful!). With matched pairs going on ebay for not _too_ much (one seller also with 'best offer'), methinks I am LOST (past saving, even)!
 Here's a link to an interesting article comparing them to some of the best 6SN7s....
  
 http://www.tnt-audio.com/accessories/shuguang_treasures_cv181_e.html
  
  
 Edit:  ps. Have just put in an offer for $100 for matched pair...wish me luck!


----------



## gibosi

hypnos1 said:


> Hey mab, Mephistopheles rides again! How can you tempt a poor fellow so?...How could I possibly part with the DRs? (Mind you, I do have a spare pair - unfortunately one has no writing on it, so had to take it on trust...will probably move them on...).
> So it looks like it's adapter-making time once again - 'She who must be obeyed' thought all was just about wrapped up. As did I!! At least those nice fat pins will be much easier to work with than the C3gs'...
> Ah well, I can always blame you, mon ami (not that I take much persuasion - they look SO beautiful!). With matched pairs going on ebay for not _too_ much (one seller also with 'best offer'), methinks I am LOST (past saving, even)!
> Here's a link to an interesting article comparing them to some of the best 6SN7s....
> ...


 
  
 Actually, you don't have to build adapters, as you can buy them ready-made (the 6CG7 has the same pin-out as your DRs):
  
 http://www.ebay.com/itm/1pc-6SN7-TO-6CG7-6FQ7-tube-adapter-for-you-amp-/191082280257?pt=US_Home_Audio_Amplifiers_Preamps&hash=item2c7d643541
  
 While I do not have a smoked-glass Brimar 6SN7GT, I do have a Brimar 13D1 (which is essentially a 25SN7GT) and the Sylvania 6SN7GT referenced in this article, and while I think they are very good, I would not rate them among the very best. But of course, this is just one man's opinion based on old ears and modest gear. 
  
 So in my opinion, if you want "curvy" CV181s of similar quality to your DRs and C3gs , I think you should get "real" CV181s:
  
 http://www.ebay.com/itm/Unique-NOS-Set-2-x-Mullard-Black-base-ECC32-CV-181-D-Getter-New-in-box-/191077832056?pt=Vintage_Electronics_R2&hash=item2c7d205578


----------



## mab1376

hypnos1 said:


> Hey mab, Mephistopheles rides again! How can you tempt a poor fellow so?...How could I possibly part with the DRs? (Mind you, I do have a spare pair - unfortunately one has no writing on it, so had to take it on trust...will probably move them on...).
> So it looks like it's adapter-making time once again - 'She who must be obeyed' thought all was just about wrapped up. As did I!! At least those nice fat pins will be much easier to work with than the C3gs'...
> Ah well, I can always blame you, mon ami (not that I take much persuasion - they look SO beautiful!). With matched pairs going on ebay for not _too_ much (one seller also with 'best offer'), methinks I am LOST (past saving, even)!
> Here's a link to an interesting article comparing them to some of the best 6SN7s....
> ...


 
  
 Good luck! hopefully you can find a pair for really cheap. It didn't seem to take much convincing!


----------



## hypnos1

gibosi said:


> Actually, you don't have to build adapters, as you can buy them ready-made (the 6CG7 has the same pin-out as your DRs):
> 
> http://www.ebay.com/itm/1pc-6SN7-TO-6CG7-6FQ7-tube-adapter-for-you-amp-/191082280257?pt=US_Home_Audio_Amplifiers_Preamps&hash=item2c7d643541
> 
> ...


 
  
 Hey gibosi : sorry, but the bank raid was a failure - have you seen the price these things go for? The item you linked hasn't even _started_ to take off! Will be VERY interesting to see the final bid...
 Thanks anyway...
 Am getting a _little_ more optimistic re the Chinese connection as I discover more Shuguang tubes in some VERY fancy equipment, so I live in hope...
 And thanks for the info re adapters -  call me a masochist (or worse!), but I really do believe making my own with some nice _silver_ wire adds a certain something to the final results...not to mention a certain satisfaction when they actually WORK!! (Pray my luck holds out lol)
  


mab1376 said:


> Good luck! hopefully you can find a pair for really cheap. It didn't seem to take much convincing!


 
  
 You caught me out, mab - you must have known I was _already_ sold on them! (I'm a sucker for a pretty skirt!!).
 At least curiosity will be satisfied...and who knows, I just _might_ get lucky, as I did with the C3gSs?? It's going to be a VERY frustrating long wait to find out...


----------



## spiderking31

I wish you would think about reviewing the Siemens 6ak5w driver tubes! They are a completely awesome tube! Would love to hear a review about them.


----------



## kvtaco17

The siemens 6ak5's were a very average tube going from memory... Congested, occasionally bright, smallish sound stage... Somewhat diffuse but not slow sounding... I remember not liking them when I had them in my amp. Out of the stock compatible tubes I would strongly urge you to try the 6HM5 and 6DT6.


----------



## spiderking31

I'll search for the tubes your recommending. See what they're going for...do you have a brand preference?


----------



## TrollDragon

I can see that Yugo sillyness starting up again...


----------



## MIKELAP

spiderking31 said:


> I'll search for the tubes your recommending. See what they're going for...do you have a brand preference?


 
 Theres a search function atop the page but its seems yugo 's and Sylvania are decent


----------



## MIKELAP

You mean this sillyness  !


----------



## spiderking31

Awesome! I'll check em out now


----------



## TrollDragon

spiderking31 said:


> Awesome! I'll check em out now


 

 These are the popular 6HM5's here...
 http://www.ebay.com/itm/6HM5-6HA5-EC900-export-quality-audio-triode-tube-NOS-FREE-SHIPPING-/300879467071


----------



## gibosi

spiderking31 said:


> I'll search for the tubes your recommending. See what they're going for...do you have a brand preference?


 
  
 From memory, Sylvania, RCA and Tung-Sol 6DT6. And tall-bottle (avoid the short bottle versions) Sylvania, "Yugoslavia" and GE (Made in Great Britain) 6HM5 /6HA5 / EC900. 
  
 Edit: Use the EF92 setting to run 6DT6 and the EF95 setting to run 6HM5.


----------



## TrollDragon

mikelap said:


> You mean this sillyness  !


 
 I've seen a few Yugo 6HM5's back in the day... 
	

	
	
		
		

		
			





 Yup that's the stuff...


----------



## spiderking31

Thanks a bunch


----------



## kvtaco17

gibosi said:


> From memory, Sylvania, RCA and Tung-Sol 6DT6. And tall-bottle (avoid the short bottle versions) Sylvania, "Yugoslavia" and GE (Made in Great Britain) 6HM5 /6HA5 / EC900.
> 
> Edit: Use the EF92 setting to run 6DT6 and the EF95 setting to run 6HM5.


 
 I concur


----------



## hypnos1

mab1376 said:


> I'm sure you could always sell the one of the two you don't like, go for it!


 
  
 Well mab, the offer of $100 wasn't accepted - thank goodness! Because it looks like the psvane CV181-T MKII could be a better bet, even though more expensive - by ex-Shuguang people.
 Just plucking up courage to go the extra mile...oh what a tangled web we weave!! This tube-rolling game is SO addictive...


----------



## spiderking31

I did some research on the Siemens 6ak5w, and reading about the exact type I have, and listening to them, I think they're the best I've come across, and I'm in love what the little treasures I've come across! The best $40 pair I've ever come across!


----------



## gibosi

spiderking31 said:


> I did some research on the Siemens 6ak5w, and reading about the exact type I have, and listening to them, I think they're the best I've come across, and I'm in love what the little treasures I've come across! The best $40 pair I've ever come across!


 
  
 It would appear that you have not read the last 250 pages, or so, of this thread.... But in the end, all that matters is that you like them. Cheers.


----------



## spiderking31

gibosi said:


> It would appear that you have not read the last 250 pages, or so, of this thread.... But in the end, all that matters is that you like them. Cheers.


 I would rather stick to the ef95 class tubes, but they're epic though! I must admit that though. They're pretty sweet!  I could try other tubes, which I've tried a few others, but this is the sweet spot


----------



## MIKELAP

Since we are talking about the older tubes we use to listen to i decided to sampled a pair a Mullard 8100 and a pair of 6DJ8 with homemade adapter. Started with the Mullard 8100 at first i was kind off surprised the sound is really detailed and bass is good but eventually i was focusing more on the highs and for me that was a bit to much  but they sound good . Now for the Amperex Bugle Boys. From the start i found those tubes to have a more balanced sound thruout also  warmer sounding in other words nothing sticks out  but detail is still there listening is relaxing imo  this is with Senns HD800 and Littledot mk3.


----------



## hypnos1

spiderking31 said:


> I would rather stick to the ef95 class tubes, but they're epic though! I must admit that though. They're pretty sweet!
> 
> 
> 
> ...


 
  
 Hi spiderking...you mentioned previously $40? OUCH!! As several 'old-timers' (sorry boys!) have advised, and which I was plugging for a long time, the tall-bottled 6HM5 was about the best straight replacement (ie EF95) we all found - mine were the Ei (Yugoslavian) tubes that TD posted a link for on 4th March and for which I had $5 offers accepted, with FREE delivery...do the maths! Sylvanias should also be good, depending where you are, but just compare prices with the tachonz link. You can't go wrong at these prices...NO fancy adapting needed!!
 Give 'em a look...
  
 Cheers


----------



## hypnos1

gibosi said:


> Actually, you don't have to build adapters, as you can buy them ready-made (the 6CG7 has the same pin-out as your DRs):
> 
> http://www.ebay.com/itm/1pc-6SN7-TO-6CG7-6FQ7-tube-adapter-for-you-amp-/191082280257?pt=US_Home_Audio_Amplifiers_Preamps&hash=item2c7d643541
> 
> ...


 
  
 On further reflection, g, your mention of ready-made adapters does actually make _very_ good sense as I can give them a try _before_ mutilating them - just in case! So thanks again for the link...
  
 As I have already posted, I think I shall be going for the Psvane CV181-T MKII instead of the Shuguang - looks like they could just be a step up ...time will tell...


----------



## gibosi

hypnos1 said:


> On further reflection, g, your mention of ready-made adapters does actually make _very_ good sense as I can give them a try _before_ mutilating them - just in case! So thanks again for the link...
> 
> As I have already posted, I think I shall be going for the Psvane CV181-T MKII instead of the Shuguang - looks like they could just be a step up ...time will tell...


 
  
 And once you have these adapters, you can also try some of the old-stock 6SN7s. While not as pretty as the new Chinese versions, they usually cost less, and according to most accounts, sound better. That said, most of the observations out there regard the use of these tubes as drivers. Since you will be using the 6SN7 as output tubes, your goal would be to find the 6SN7 that has the best synergy with your C3gs. So my advice is try some cheap Sylvanias, Tung-Sols and/or RCAs to get a feel for how the 6SN7 plays with your C3s before spending the big bucks on a Psvane. 
  
 Cheers.


----------



## hypnos1

gibosi said:


> And once you have these adapters, you can also try some of the old-stock 6SN7s. While not as pretty as the new Chinese versions, they usually cost less, and according to most accounts, sound better. That said, most of the observations out there regard the use of these tubes as drivers. Since you will be using the 6SN7 as output tubes, your goal would be to find the 6SN7 that has the best synergy with your C3gs. So my advice is try some cheap Sylvanias, Tung-Sols and/or RCAs to get a feel for how the 6SN7 plays with your C3s before spending the big bucks on a Psvane.
> 
> Cheers.


 
  
 Oh gee,g, - why do you have to give such good, sensible advice? Do you not realise I am TOTALLY infatuated?! (Which, of course, means totally besotted/illogical/insane!). So I'm afraid I can't promise to be a good boy and _take_ it!
 The crux/problem of the matter is that, as you said, there is a dearth of info re. their use (6SN7 generally) as POWER tubes...So this is all just a stab in the dark - hey, weren't there a couple of guys in the process of experimenting with same? WHERE ARE YOU? Help, please!
 The dilemma also is that there could be quite a difference between what the usual 6SN7s do in their new role, compared to the Psvanes. Thus, I am of a mind to experiment with BOTH - in the name of our honour-bound duty to promote research in this hallowed thread (either that or I really AM just plain crazy). And as mab (optimistically?) said, I could always move them on - or try to at least...I really do have the bit between my teeth, don't I?
 Not to mention the fact that usually I try to be ultra 'sensible', but which I am finding_ increasingly_ boring!! (Just be there to catch me if I fall, lol!...).
  
 BTW...Can you remind me of your current favourites?
  
 Thanks


----------



## mordy

I have been trying a number 6SN7 as driver tubes with excellent results. Almost all the tubes I tried sound good, and some sound excellent. Current favorites are mid 60's RCA tubes with a thin heater wire horizontally across above the top mica, a '52 Sylvania GTA, and a Japanese Channelmaster rebranded tube.
  
 These tubes are inexpensive and plentiful - wish somebody would compare them to the hyped up and overpriced exotics. Something tells me that these plebeian tubes will rate very well in comparison....


----------



## gibosi

While I do not have the RCA or the Channelmaster, I do have the small-bottle, chrome-dome Sylvania 6SN7GTA. And yes, the chrome-dome compares very well as a driver tube to the Sylvania 6SN7W, which is my current favorite. However, I find the chrome-dome to be just a tad bit too dry and thin in the mid range compared to the 6SN7W.
  
 That said, my hunch is that an output tube should be essentially neutral. And if not, I think it is better that it is too thin rather than too fat. For example, I have read that the Sylvania VT-231, which many find to be a bit too thin in the bass when used as a driver, is excellent as an output tube. Similarly, I would guess that the chrome dome might also be an excellent output tube, and they are cheap too.


----------



## mordy

Some time ago we compared various power tubes for the LD MKIII. 6N6P, 6N6Pi, 6N6P-IR and 6H30-DR. The last two were the best, the IR tube being a best buy. However, what distinguished one tube over another was the bass detail and punch, and nobody mentioned how neutral sounding the tube was.


----------



## hypnos1

mordy said:


> Some time ago we compared various power tubes for the LD MKIII. 6N6P, 6N6Pi, 6N6P-IR and 6H30-DR. The last two were the best, the IR tube being a best buy. However, what distinguished one tube over another was the bass detail and punch, and nobody mentioned how neutral sounding the tube was.


 
  
 Using logic as the yardstick, having noticed so many different 'sounds' depending on the (many) _drivers_ I have partnered with my DRs, I think it might be fair to assume that the latter remained throughout fairly neutral in the equation...but perhaps my logic is flawed?! I welcome any further comments...where on Earth are you, Audiofanboy - is there no internet in Japan?!!


----------



## gibosi

To take this a bit further, if you are going to live with only one output tube, it would be optimal to have it be as neutral as possible, as this allows the sonic character of each driver tube to be revealed. And this is what makes the DRs very special as they do seem to be very neutral and transparent.
  
 That said, the chance of a 6SN7, or any other double triode for that matter, being better than the DRs is likely very slim. But there is only one DR, whereas there are many, many 6SN7s. With so many to choose from, the selection of an output tube can be transformed into a rather different game, as the huge selection of 6SN7s offer the possibility of finding that one output tube which is the "perfect" match for a particular driver tube.
  
 For example, the NU 6SN7GTs are typically quite bassy. Some have discovered that matching it with a 1940's Sylvania 6SN7GT, with it's thinner bass, but rather forward mids and highs is a great match. But for sure, rolling through many tubes in this manner take lots of time and money.
  
 So in my opinion, to start, I would go for the most neutral 6SN7 I could find. And from my limited experience, I would start with a pair of Sylvania 6SN7GTAs or Tung-Sol "mouse ears".


----------



## i luvmusic 2

How do i wire 6SN7 to 12AU7?I have a 9 pin socket and the 8 pin socket and Power Supply all i need is to wire them it's just i have no clue how to do it.


----------



## gibosi

i luvmusic 2 said:


> How do i wire 6SN7 to 12AU7?I have a 9 pin socket and the 8 pin socket and Power Supply all i need is to wire them it's just i have no clue how to do it.


 
  
 I am not sure I understand exactly what you want to do....  Why do you want to wire a 6SN7 to a 12AU7???


----------



## i luvmusic 2

gibosi said:


> I am not sure I understand exactly what you want to do....  Why do you want to wire a 6SN7 to a 12AU7???


 
 I have a Bravo Audio Ocean Amp that use 12AU7 so i want to try if i can use a 6SN7 with it.THANK YOU!


----------



## i luvmusic 2

Will these work?
 6SN7   To    12AU7
 1                   2
 2                   1
 3                   3
 4                   7
 5                   6
 6                   8
 7
 8


----------



## gibosi

i luvmusic 2 said:


> I have a Bravo Audio Ocean Amp that use 12AU7 so i want to try if i can use a 6SN7 with it.THANK YOU!


 
  
 First, do you know if your 12AU7 is running on 6V heaters? Or 12V heaters?


----------



## gibosi

If you do not know, then take a voltmeter and measure the voltage between pins 4 and 9. The voltage is likely DC as this amp runs off of a 24V adapter. If no voltage, then it is 12V. Otherwise, you should see 6V. (TrollDragon, please correct me if I am wrong!


----------



## TrollDragon

Scratch all that...

ILM2 has an external power supply, so all you have to do is match up the Anode / Grid / Cathode of both sides and use the external p/s for your 6V... The next post still applies IMHO.


----------



## TrollDragon

Personally I would not bother putting Octals on a Bravo Ocean. You probably won't be able to adjust the bias on that tube.


----------



## gibosi

Oh, I overlooked that you are using an external power supply, so yes, all you have to do is match up the Anode / Grid / Cathode on each side and you are good to go.
  
 As to the biasing... I figure you don't know until you try. I have a friend using a 6SN7 in his Crack (modded with a DC PS), which also comes stock with a 12AU7, and it sounds great.
  
 Also, I encourage you to try an E80CC, as it is considered an upgrade to the 12AU7. However, the heater current is twice that of the 12AU7, so you will likely have to use your external PS.


----------



## i luvmusic 2

THANK YOU TD and Gibosi i will try!


----------



## i luvmusic 2

Sorry to say that the 6SN7 to 12AU7 for my Bravo did not work properly i double ckecked my wirings still no luck.the LED Power indicator on Bravo turned RED and eventualy shuts off but i can still hear music even the indicator is off and the volume knob turned all the way up just to hear a little music from it but to my surprise no hum/noice at all.


----------



## TrollDragon

trolldragon said:


> Personally I would not bother putting Octals on a Bravo Ocean. You probably won't be able to adjust the bias on that tube.


----------



## gibosi

This is good to know. It is interesting that two 12AU7 amps, the Crack and the Bravo Ocean, react so differently when substituting 6SN7s. I wonder if it is perhaps due to the Ocean having only one amplification stage, whereas the Crack has two stages, a driver and an output?  And I continue to be amazed at the huge variety of tubes we can run in our LDs with nary a problem.


----------



## TrollDragon

gibosi said:


> This is good to know. It is interesting that two 12AU7 amps, the Crack and the Bravo Ocean, react so differently when substituting 6SN7s. I wonder if it is perhaps due to the Ocean having only one amplification stage, whereas the Crack has two stages, a driver and an output?  And I continue to be amazed at the huge variety of tubes we can run in our LDs with nary a problem.


 
  
 I think it has a lot to do with the way the Bravo provides filament power to the tube, where the Crack has a heater winding directly from the transformer.
  
 The Bravo, depending on the version uses a transistor and zener or LM317 regulator to provide the 6.3 VDC heater power... You could probably make enough modifications to the Bravo to allow octals to work but why...
  
 It's basically a solid state amp with a little piece of glowing glass on top, to put it a lot nicer than a comment that was made about the Bravo Ocean in another thread which I won't repeat here.


----------



## gibosi

While I don't want to encourage ILM2 to go to the trouble and expense to procure a simple 6SN7 to 12AU7 adapter, which would therefore use the Ocean's internal heater circuit, I wonder if that would work?


----------



## TrollDragon

In theory it should providing the heater current is within limits... I only found user type schematics on line for the Ocean, so I could not be 100% sure that they are not using the a 12V heater. He would still have to measure pins 4&5 to see if there is 12V. There was no board layout to see how pins 4,5 and 9 are configured. ILM2 could take his amp apart and post pictures of the board top and bottom if he wants to.


----------



## gibosi

And as the E80CC draws twice the 12AU7's heater current, running one of these using the Ocean's internal heater supply raises same question regarding the maximum heater current available....


----------



## gibosi

Received three ECC40s today.
  
 First up, one with a metal base, 1951, manufactured in Hamburg. Note the interesting getter shape.
  

  
 And then two more, apparently manufactured in 1955, but I have no idea where. These factory symbols don't look like anything here:
  
 http://tubedata.milbert.com/other/Philips/PhilipsCodeListAB-v10.pdf
  
 But maybe a fresh set of eyes can figure this out?


----------



## i luvmusic 2

Sorry guys i know this is not a Bravo thread IMO this the only place i can get help for this Amp.I measured the voltage between Pin 4 & 5 = 0V  Pin 4 & 9 = 21.9V and Pin 5 & 9 = 21.9V PCB pictures to follow.THANKS!


----------



## Oskari

gibosi said:


> And then two more, apparently manufactured in 1955, but I have no idea where. These factory symbols don't look like anything here:


 
  
 That's a 4, and a deformed character probably supposed to be a 4.


----------



## gibosi

oskari said:


> That's a 4, and a deformed character probably supposed to be a 4.


 
  
 4 = Venolanda S.A., Venezuela
  
 Ummmm.... Does it seem reasonable to then conclude that these were actually manufactured in Venezuela in 1955 using Philips production equipment?


----------



## Oskari

Eindhoven, again. 
	

	
	
		
		

		
			




  

http://frank.pocnet.net/other/Philips/PhilipsCodeList.pdf


----------



## gibosi

i luvmusic 2 said:


> Sorry guys i know this is not a Bravo thread IMO this the only place i can get help for this Amp.I measured the voltage between Pin 4 & 5 = 0V  Pin 4 & 9 = 21.9V and Pin 5 & 9 = 21.9V PCB pictures to follow.THANKS!


 
  
 While the measurements seem strange, I would conclude that that 0V across pins 4 - 5 suggests 6.3 volts.
  
 My best suggestion:
  
 Send an email to 
  
 info@bravoaudio.com
  
 And ask two questions:
  
 1) Is it safe to roll E80CCs in the Ocean?
  
 2) Is the 12AU7 configured in 6.3 mode or 12.6 mode?


----------



## gibosi

oskari said:


> Eindhoven, again.
> 
> 
> 
> ...


 
  
 Oh, this scan is different than the pdf I have been using. But when looking at old tubes this scan looks to be more useful. Thanks!


----------



## i luvmusic 2

gibosi said:


> While the measurements seem strange, I would conclude that that 0V across pins 4 - 5 suggests 6.3 volts.
> 
> My best suggestion:
> 
> ...


 
 OK THANKS!


----------



## i luvmusic 2




----------



## gibosi

trolldragon said:


> I think it has a lot to do with the way the Bravo provides filament power to the tube, where the Crack has a heater winding directly from the transformer.
> 
> The Bravo, depending on the version uses a transistor and zener or LM317 regulator to provide the 6.3 VDC heater power... You could probably make enough modifications to the Bravo to allow octals to work but why...


 
  
 Would it be feasible to strap a resister across the heater pins to fake the Bravo into "thinking" there is a tube inserted in the socket? And then he could make the appropriate connections from his octal socket to the Bravo and use his external heater PS?
  
 (And again, I know just enough about electrical circuits to be dangerous! lol


----------



## TrollDragon

@ILM2 Excellent!
 I'll have to look at the board in a little bit.
  
 @gibosi I don't think that would be good a good idea but I'll have a look at the board and see what might be.


----------



## i luvmusic 2

These is the AMP that got me started buying the DT and Q Headphones followed by LD MK III and then the LD 1+  i know it's not the best amp out there but IMO i can plug in any headphone i have and it able to drive them all and the sound from it is not that bad in that price range.If we can manage to run it with 6SN7 tube it would be nice and in end if not then back  into the drawer.


----------



## i luvmusic 2

gibosi said:


> Would it be feasible to strap a resister across the heater pins to fake the Bravo into "thinking" there is a tube inserted in the socket? And then he could make the appropriate connections from his octal socket to the Bravo and use his external heater PS?
> 
> (And again, I know just enough about electrical circuits to be dangerous! lol


 
  
  


trolldragon said:


> @ILM2 Excellent!
> I'll have to look at the board in a little bit.
> 
> @gibosi I don't think that would be good a good idea but I'll have a look at the board and see what might be.


 
 THANK YOU!


----------



## TrollDragon

Hey ILM2
  
 OK looking at the board it appears that pin 9 goes to ground. Can you carefully give me 2 voltage readings from the two points in red with you negative probe on the black point. DC Volts and a 12AU7 tube has to be installed for doing this.

  
 Also can you read the numbers off of these two components circled in red, I believe they are LM317's but can't find any pictures on the net to verify.

  
 The schematic's I have seen around seem to deal with those ugly Bravo amps in the plexiglass as opposed to the Ocean.


----------



## mab1376

Got two new production tung sol 6SN7GTB's running as power tubes with a 6SU7GTY as the driver, AMAZING!
  
 Bass is well defined, mids are very forward and real (I kept thinking my speakers were on), highs are super extended and sweet. and everything is crystal clear!
  
 I love this combination!


----------



## gibosi

mab1376 said:


> Got two new production tung sol 6SN7GTB's running as power tubes with a 6SU7GTY as the driver, AMAZING!


 
  
 Great news!!
  
 I have been waiting for someone to try running 6SN7s as power tubes in their LD. I was pretty sure that electrically, they would work fine, but I wondered how they might sound....
  
 And I think 6SN7s might have less gain than the standard tubes.... So do you find that you are setting the volume a bit higher than before?
  
 Oh.. and by "new production", do you have the Tung Sols made in Russia?


----------



## Dr4Bob

I am using a pair of Raytheon N.O.S. 6AK5 in the Mk II- absolutely stunning in the amp both as a headphone amp driving DT880 600ohm cans as well as a preamp feeding a Virtue Two.2 amp for my power loving Role Sampans.


----------



## i luvmusic 2

1st Reading=5.09V    and     2nd Reading=5.09V
                                                                                                                                                                      
                                                                        
                                                                       IRF 630N
 Thank You TD!


----------



## mab1376

gibosi said:


> Great news!!
> 
> I have been waiting for someone to try running 6SN7s as power tubes in their LD. I was pretty sure that electrically, they would work fine, but I wondered how they might sound....
> 
> ...


 
  
 I normally play at 12 o'clock, with these i use 1 o'clock, so minimal difference.
  
 and yes they're from russia.


----------



## hypnos1

mab1376 said:


> Got two new production tung sol 6SN7GTB's running as power tubes with a 6SU7GTY as the driver, AMAZING!
> 
> Bass is well defined, mids are very forward and real (I kept thinking my speakers were on), highs are super extended and sweet. and everything is crystal clear!
> 
> I love this combination!


 

 Well done mab...indirectly you have me sleeping a _little_ better at night as finally, at last_,_ I have incontrovertible proof of my insanity - against all gibosi's sensible advice to try some cheaper 6SN7s first (sorry g!), I have bitten the bullet and gone for some Psvane CV181-T MKIIs (supposedly a step up from the Shuguang CV181-Z). If they come near (or even surpass?) your findings, I shall be a happy chappie...at least I will have achieved the _look_ I seek...But , of course, it's very much down to how things partner each other, so I live in hope (not to mention patience...ie that darned _slow boat_!).
 And I now realise it's not _you_ I should blame for leading me astray - 'tis thou MORDY shouldst take the blame, viz your post saying things had gone quiet, and inciting to 'wake things up'!!.(Well, I can't blame _myself_ now can I?!).
  
 Perhaps you will be trying some of gibosi's musings on different 6SN7s as power tubes -  or are you now happy enough as things are?...
 We wait with baited breath!...


----------



## CollectoR13

Great to read good comments about 6sn7 as power tube! 
My parts finally arrived and i am going to build my clean adapter in the next days. 
Would you wish to see a picture by picture tutorial on how to assemble? 
I think it could serve newbies (actually i am a tube wiring etc newbie, too XD) very well if they decide to build one... 
And also i will give something back to the community! 
Hopefully all works like i imagined! XD


----------



## mordy

Hi Dr4Bob,
  
 Is it safe to smoke in the underground bunker? LOL....
  
 Anyhow, way back then I tried several different 6AK5 Raytheon tubes. I found that the the only type I liked was from the 50's and had a large mica plate as the top one, and a much smaller mica plate underneath. The smaller plate did  not reach the glass envelope and was supported by the wires and pins underneath.
  
 Is this the Raytheon tube you refer to?


----------



## mordy

Hi hypnos1,
  
 Thank you for your kind comments. Truth is, I am perfectly happy to listen to the offspring of a 6SN7 and a 6DJ8. This baby is called 8FQ7 and made for Raytheon in Japan, probably by Hitachi. This tube has amazing clarity and musicality, and great treble and amazing bass detail and punch.
  
 But I am not adverse to try 6SN7 as power tubes; I am just wondering if I am capable of building the adapters needed. Gibosi's solderless breadboard solution suits me fine,
  
  
 Hi CollectoR13,
 Please share with us how you build the adapters for the 6SN7 tubes as power tubes.


----------



## gibosi

collector13 said:


> My parts finally arrived and i am going to build my clean adapter in the next days.
> Would you wish to see a picture by picture tutorial on how to assemble?
> I think it could serve newbies (actually i am a tube wiring etc newbie, too XD) very well if they decide to build one...
> And also i will give something back to the community!


 
  
 Please do!
  
 Currently, I am very happy with my ugly and easy, "wires-flying-everywhere" adapters. But I am sure that eventually I might want to put together some clean and "pretty" adapters, and I would much rather copy than invent! lol


----------



## gibosi

mordy said:


> Please share with us how you build the adapters for the 6SN7 tubes as power tubes.


 
  
 Or you can purchase a couple of pre-made adapters:
  
 http://www.ebay.com/itm/1pc-6SN7-TO-6CG7-6FQ7-tube-adapter-for-you-amp-/191082280257?pt=US_Home_Audio_Amplifiers_Preamps&hash=item2c7d643541


----------



## mab1376

hypnos1 said:


> Well done mab...indirectly you have me sleeping a _little_ better at night as finally, at last_,_ I have incontrovertible proof of my insanity - against all gibosi's sensible advice to try some cheaper 6SN7s first (sorry g!), I have bitten the bullet and gone for some Psvane CV181-T MKIIs (supposedly a step up from the Shuguang CV181-Z). If they come near (or even surpass?) your findings, I shall be a happy chappie...at least I will have achieved the _look_ I seek...But , of course, it's very much down to how things partner each other, so I live in hope (not to mention patience...ie that darned _slow boat_!).
> And I now realise it's not _you_ I should blame for leading me astray - 'tis thou MORDY shouldst take the blame, viz your post saying things had gone quiet, and inciting to 'wake things up'!!.(Well, I can't blame _myself_ now can I?!).
> 
> Perhaps you will be trying some of gibosi's musings on different 6SN7s as power tubes -  or are you now happy enough as things are?...
> We wait with baited breath!...


 
  
 Definitely give it a try with a 6SN7/6SL7/6SU7 driver tube if it doesn't seem all that impressive with the c3g's! I'm loving my 6SU7GTY.


----------



## TrollDragon

i luvmusic 2 said:


> IRF 630N
> Thank You TD!


 
  
 Sorry been out all day long and wasn't able to make this post for you.
  
 The 12AU7 is run in 6V mode.
  
 Are you sure that those two are IRF 630N's? They are the output mosfets and should be on the other side?
 Ok then what are the numbers of the two on the other side? 
	

	
	
		
		

		
			




  
 The LM317 max's out at 1.5A, it provides the current for the mosfets and the 12AU7 filament.
  
So you can test it by running wires out to a socket matching both sides of the 12AU7  Anode / Gate / Cathode with the 6SN7 pins.
You will use pin 5 and 9 from the bravo socket for your octal filaments, it does not matter which way you hook them up to the octal socket, 5 to 7 and 9 to 8 or vice versa. 
  
The LM317's will probably get a LOT hotter from the doubled current draw, you will have to watch for this and if it gets TOO hot, I'd just forget about the octal in the bravo amp.
  
 Thinking about this further, the two LM317's (to be confirmed by ILM2) are providing 6V to each side of the 12AU7's filaments with the center tap to ground. This also provides a load for the LM317 and for the IRF 630N mosfets. So no you will not be able to run a 6SN7 tube easily. I can't tell you to jumper pin 4 and 5 to 9 with a resistor and use an external power supply on the tube as I do not know what size and wattage resistor you would need to make this work.
 Sorry.
	

	
	
		
		

		
		
	


	



  
 You can feel free to experiment, but you do it at your own risk to the amp.


----------



## gibosi

trolldragon said:


> Sorry been out all day long and wasn't able to make this post for you.
> 
> Thinking about this further, the two LM317's (to be confirmed by ILM2) are providing 6V to each side of the 12AU7's filaments with the center tap to ground. This also provides a load for the LM317 and for the IRF 630N mosfets. So no you will not be able to run a 6SN7 tube easily. I can't tell you to jumper pin 4 and 5 to 9 with a resistor and use an external power supply on the tube as I do not know what size and wattage resistor you would need to make this work.
> Sorry.
> ...


 
  
 Suppose we tie pins 4 and 5 together and then measure the resistance across pins 5 and 9 of a 12AU7, held in our hand, and not plugged in! Wouldn't this give us the value of the internal resistance of the tube's internal 6V heater circuit? Or is it just not that simple (as usual)?
  
 Edit: Oops!! should be pins 4 and 5!


----------



## TrollDragon

gibosi said:


> Suppose we tie pins 4 and 6 together and then measure the resistance across pins 5 and 9 of a 12AU7, held in our hand, and not plugged in! Wouldn't this give us the value of the internal resistance of the tube's internal 6V heater circuit? Or is it just not that simple (as usual)?


 

 Tube filaments change resistance (goes up) when they heat up, it might be 4 ohms cold and 90 when hot.
  
 The circuit uses the LM317's not in the same way your regulator does, such as put 12V in and adjust to 6V out. These are tied into the output of the mosfets through the tube filaments to ground like a constant current or voltage source.
  
 The pictures do not show if pins 4 & 5 on the board are tied together, there might be a trace joining them under the socket. This could be measured with the amp shut off for a while to let the capacitors drain, then measure the resistance across pins 4 & 5 with the tube out and see if it is 0 ohms. If that is the case then 4 & 5 are most likely bridged and it might possibly just work with a 6SN7 using pins socket 5 & 9 to the octals 7 & 8.
  
 ILM2 will have to decide if he wants to experiment with this and see.


----------



## hypnos1

mordy said:


> Hi hypnos1,
> 
> Thank you for your kind comments. Truth is, I am perfectly happy to listen to the offspring of a 6SN7 and a 6DJ8. This baby is called 8FQ7 and made for Raytheon in Japan, probably by Hitachi. This tube has amazing clarity and musicality, and great treble and amazing bass detail and punch.
> 
> But I am not adverse to try 6SN7 as power tubes; I am just wondering if I am capable of building the adapters needed. Gibosi's solderless breadboard solution suits me fine,


 
  
 Actually, mordy, I'm beginning to feel that rather than castigate you (and mab) I should be sending you (and him) my greatest thanks...I'm sensing in my bones that good things are on their way (literally!). So now, rather than with trepidation, I am awaiting the consequences of my rash decision with eagerness. 
	

	
	
		
		

		
			




 At the very least perhaps I may have helped gee things along a bit in this particular direction (but full marks go to mab, of course)...and to echo gibosi's sentiments, it amazes me also what we are able to do with our LDs...and still they beg for more! I can't think of any other units that are so forgiving, or that have made such massive improvements from stock without the need for equally massive (and costly) mods...perhaps somebody else knows differently?...
  
 Cheers!


----------



## hypnos1

mab1376 said:


> Definitely give it a try with a 6SN7/6SL7/6SU7 driver tube if it doesn't seem all that impressive with the c3g's! I'm loving my 6SU7GTY.


 
  
 As per my post to mordy, I feel thanks are in order after all...am feeling much more positive about the whole thing! 
	

	
	
		
		

		
		
	


	



  
 I must admit, though, I _am_ putting all my faith in the Psvanes...from what I have been able to glean, it would appear they shouldn't have _too_ negative an impact on the C3GSs, which are providing such an incredible signal to play with (but no guarantees, of course!).
  
 And really don't fancy altering the look with the mods necessary to run 6SN7s as drivers. So wish me luck!!
  
 Cheers!
  
 ps. So glad you are still loving your new power tubes...you didn't have the DRs did you?


----------



## mab1376

> ps. So glad you are still loving your new power tubes...you didn't have the DRs did you?


 
  
 I was running 6N6P-IR previously, and EH 6H30Pi prior to that.
  
 I'm using these adapters: http://www.ebay.com/itm/250751485737?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649
  
 They sent me 2 sets of adapters BTW.


----------



## mordy

Hi mab1376,
  
 If I understand correctly, you are running two 6SN7 tubes as power tubes and another 6SN7 as a driver tube?
  
 Could you describe the difference between the IR power tubes and the 6SN7 power tubes? Is there a substantial difference that you feel will make it worthwhile to change from the IR tubes to the 6SN7 tubes?


----------



## Oskari

trolldragon said:


> Tube filaments change resistance (goes up) when they heat up, it might be 4 ohms cold and 90 when hot.


 
  
 Shouldn't a hot one be simply _Uf_ / _If _ ? No?


----------



## hypnos1

mab1376 said:


> I was running 6N6P-IR previously, and EH 6H30Pi prior to that.
> 
> I'm using these adapters: http://www.ebay.com/itm/250751485737?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649
> 
> They sent me 2 sets of adapters BTW.


 
  
 Hi mab.
  
 Things are looking up...if they are surpassing both those tubes - my EHs equipped themselves very well, even compared to the DRs - then I am filled with even _more_ hopeful expectation...(just hope I'm not setting myself up for a fall!).
  
  
 Thanks for the link...


----------



## samtheman

gibosi said:


> Or you can purchase a couple of pre-made adapters:
> 
> http://www.ebay.com/itm/1pc-6SN7-TO-6CG7-6FQ7-tube-adapter-for-you-amp-/191082280257?pt=US_Home_Audio_Amplifiers_Preamps&hash=item2c7d643541


 
  
 Thanks for the link - just ordered a pair.
  
 Does anyone have a suggestion for a reasonably priced pair of 6SN7s to run as power tubes with these, apart from the re-issue tung sol 6SN7GTBs?


----------



## i luvmusic 2

trolldragon said:


> Sorry been out all day long and wasn't able to make this post for you.
> 
> The 12AU7 is run in 6V mode.
> 
> ...


 
 Thank You for all the info/help(specially to TrollDragon and Gibosi)i tried all the method that you guys suggested but in the end it is not worth it using octal on BRAVO it HEAT UP a lot i may risk on burning the amp.Yes TD it is LM 317T and also by using octal the voltage measurment on those pins went up to 14V(pin 9 to 4 and 5)the sound was distorted and by strapping resistors i tried that too it did work(sound is distorted) and the IRF 630N(with resistors strapped) it gets overheated  soo i decided not to bother converting, after all we all have this AMAZING AMP(LITTLE DOT) Rolling all kinds of tubes and it sound amazing again THANK YOU for all you HELP!


----------



## TrollDragon

oskari said:


> Shouldn't a hot one be simply _Uf_ / _If _ ? No?


 
 Yes indeed, all he would have to do is measure the voltage between pins 5 & 9 with a voltmeter to get V.
 Break the connection to pin 9 and put an ammmeter in series with it to get I.
 Then the hot filament resistance R could be calculated.
  
 R = V/I


----------



## TrollDragon

i luvmusic 2 said:


> Thank You for all the info/help(specially to TrollDragon and Gibosi)i tried all the method that you guys suggested but in the end it is not worth it using octal on BRAVO it HEAT UP a lot i may risk on burning the amp.Yes TD it is LM 317T and also by using octal the voltage measurment on those pins went up to 14V(pin 9 to 4 and 5)the sound was distorted and by strapping resistors i tried that too it did work(sound is distorted) and the IRF 630N(with resistors strapped) it gets overheated  soo i decided not to bother converting, after all we all have this AMAZING AMP(LITTLE DOT) Rolling all kinds of tubes and it sound amazing again THANK YOU for all you HELP!


 
 You are most welcome, anytime!
  
 That is too bad though, I figured it probably would not work without some major board rework...
  
 And like I said quite a few pages back. 
	

	
	
		
		

		
		
	


	




 
    
 Quote:


trolldragon said:


> Personally I would not bother putting Octals on a Bravo Ocean. You probably won't be able to adjust the bias on that tube.


 Just Kidding...


  
 But you did have some fun and it was a great experiment to try out! Leave the little Blue amp just as it is and enjoy *The LD Rolling Extravaganza!*


----------



## gibosi

samtheman said:


> Does anyone have a suggestion for a reasonably priced pair of 6SN7s to run as power tubes with these, apart from the re-issue tung sol 6SN7GTBs?


 
  
 In this forum we have very little experience using 6SN7s as power tubes in our LDs. To my knowledge, mab1376 is the only one. So my advice is to go by price. By a cheap pair of RCA,. Sylvania, Tung-Sol, Raytheon, or whatever, and see how they sound. You could get a pair of the old Russian equivalents, 6N8S, pretty cheap too. Personally, I think Sylvanias and Tung-Sols might be pretty good as they are fairly balanced and neutral, but this is just wild guess on my part....


----------



## i luvmusic 2

trolldragon said:


> You are most welcome, anytime!
> 
> That is too bad though, I figured it probably would not work without some major board rework...
> 
> ...


 
 Oh yeah i had alot of fun and learn something from it to DO NOT USED YOUR FINGER AS ATHERMOMETER FOR THOSE HEAT SINK lol


----------



## samtheman

Thank you gibosi - you are always so helpful to everyone.


----------



## TrollDragon

i luvmusic 2 said:


> Oh yeah i had alot of fun and learn something from it to DO NOT USED YOUR FINGER AS ATHERMOMETER FOR THOSE HEAT SINK lol


 

 Been there, done that, got the blister or two... 
	

	
	
		
		

		
		
	


	



  
 Now what you really need to do is work on a TV where the High Voltage wire going to the picture tube has a crack in the insulation, poking around taking measurements you happen to lean too close to the wire and *SNAP*, a 30 kV spark jumps to your nose... Yank your head back bumping it on the cabinet, just an excellent time, I really hated console TV sets.
  
 But that was a long time ago, in a land far far away.


----------



## TrollDragon

Well I dug out the old 6H9C again and decided to give it another listen.
  
 Changed out the ceramic B9A for a machined pin ceramic Octal socket.

  
 Not one of the prettiest tubes when it comes to glow...

  
 This Great Album was sent to me and I thought I'd give it a listen with the 6H9C.

 I don't remember the 6H9C sounding this good for a cheap soviet tube.
  
 Listening with the GMP 8.300D's this Jazz Fusion album has some ultra sweet bass lines, and the 6H9C is providing a really nice punch to the GMP's. I am seriously impressed, a totally different experience than what I remember when I first tried the tube.


----------



## MIKELAP

trolldragon said:


> Well I dug out the old 6H9C again and decided to give it another listen.
> 
> Changed out the ceramic B9A for a machined pin ceramic Octal socket.
> 
> ...


 
 Thats what i figure to for the price( $5.00 ) compared to the other 6SL7 they sound pretty good .


----------



## mab1376

mordy said:


> Hi mab1376,
> 
> If I understand correctly, you are running two 6SN7 tubes as power tubes and another 6SN7 as a driver tube?
> 
> Could you describe the difference between the IR power tubes and the 6SN7 power tubes? Is there a substantial difference that you feel will make it worthwhile to change from the IR tubes to the 6SN7 tubes?


 
 I'm using a 6SU7GTY as the driver which is closer to 6SL7 tubes.
  
 To me the difference seems like an all around extension on all frequencies and much warmer. The IR tubes seem thin sounding in comparison.
  
 I would rate the IR tubes as a 7 out of 10 and the 6SN7 tubes as an 8.5 as far as overall SQ. The sound is very real and spacious, one thing that keeps happening with my HD650's is i keep thinking i have my speakers on by accident.
  
 if you could do it for the price of some IR tubes or cheaper it's 100% worth it.


----------



## mordy

The 6H9C is a Russian 6SL7 tube. IMHO the LD MKIII sounds better with the 6SN7 as a driver tube. Has anybody tried the Russian equivalent 6H8C?
  
 These tubes can also be found fairly inexpensive.


----------



## i luvmusic 2

mordy said:


> The 6H9C is a Russian 6SL7 tube. IMHO the LD MKIII sounds better with the 6SN7 as a driver tube. Has anybody tried the Russian equivalent 6H8C?
> 
> These tubes can also be found fairly inexpensive.


 
 Hi Mordy,
     Yes i have that tube compared to my Westinghouse 6SN7GTA i prefer the 6H8C, IMO it have a better sound than my 6SN7.


----------



## gibosi

ECC40 -  Preliminary impressions:
  
 I have been living in ECC40 land for some time now, with 6 tubes in house and 5 more on the way.  My thinking is these are essentially 6SN7s in a different bottle: that is, Philips 6SN7s if you will. The ECC40 was introduced by Philips in 1948 to replace the 6SN7GT. However, as the ECC40 was among the first of the all-glass construction vacuum tubes, the micanol octal base was discarded in favor of the glass rimlock B8A base. Evidently, the rimlock base never really took hold, as it was soon replaced by the ubiquitous B9A base used in the production of 12AUX7s, 6DJ8s and many, many others. Even so, Philips continued to manufacture the ECC40 on a rimlock base well into the 1970's.
  
 I currently have tubes manufactured in Chartres, Sittard, Eindhoven and Hamburg, and notice the same country-specific sonic signatures we have noticed before. The ECC40 manufactured in Chartres, warm with rather punchy highs, is similar to the ECC88 manufactured in Suresnes. The Hamburg-made ECC40 has a similar sound signature to the Hamburg-made ECC88s, a bit dry, with nice airy highs, but not as punchy as the highs on the French tubes. And the Sittard-made ECC40 most strongly resembles the Heerlen-made ECC88 and E80CC. (I am told that Mullard manufactured the ECC40 in Britain, but have yet to get one.)
  
 In the early 1950's it appears that there was a cluster of perhaps 9 distinct factories and/or production lines located Eindhoven, each with a distinct factory symbol. To date, I have seen ECC40s bearing 5 different Eindhoven factory symbols, and possess three of them. I have yet to spend any significant time with these Eindhoven tubes, as I have a couple more coming, and hope to evaluate them later as a group. However, based on first impressions, they appear to be similar to the Sittard tube.
  
 While I am still in the process of evaluating the ECC40, I can say that the Sittard-made ECC40 is very comparable to the Heerlen-made E80CC and Sylvania 6SN7. In other words, it is already one of my favorite tubes. And for those with darker systems, the Hamburg-made ECC40 may well be spot on. Yes, you do need a rimlock adapter, but I think you will find these tubes to be well worth the trouble. Highly recommended.
  
 1953 Dario (Sittard-made) ECC40


----------



## mab1376

Sorry for the grainy cell pic


----------



## mordy

I am sure it sounds great! I too, would like to try a setup with 6SN7 as power tubes, but I do not know how to remove the decorating rings around the tube sockets. These rings do not allow the socket adapter to be seated in the socket. (I tried it with a different socket I have for octal to 12AX7)
  
 The adapter rings on sale on Ebay look like they are screwed in from underneath with two screws.
  
 Does anybody know how to remove the two rings from the chassis for the power tubes on the Little Dot MkIII?


----------



## TrollDragon

My guess would be from inside, the MKIV has the cages screwed down from the top or you can remove the whole plate to take all 4 off at once.

Sorry, you'll have to probably disassemble the amp to take them off, and that is a little bit of work.

You could always add a couple of 9 pin socket savers to allow your adapters to plug in.


----------



## MIKELAP

trolldragon said:


> My guess would be from inside, the MKIV has the cages screwed down from the top or you can remove the whole plate to take all 4 off at once.
> 
> Sorry, you'll have to probably disassemble the amp to take them off, and that is a little bit of work.
> 
> You could always add a couple of 9 pin socket savers to allow your adapters to plug in.


 
 Could those rings just be glued on because they seem to just sit on the chassis for mk3 anyways


----------



## TrollDragon

It's possible, a little JB Weld and those rings would be there solid!

A quick tap with a hammer and block of wood will let you know if they are. 

I'll still bet on 2 little Phillips screws holding each on from the underside of the top.

If you took the faceplate off the MKIII you could peek inside and see, it might be just clips but I doubt it.


----------



## TrollDragon

Probably not clips from looking at that picture, which I missed the first time through... Mobile browser...

Knowing the incredible lack of quality control that the Chinese have, if they did glue them I can guarantee every ring would be crooked and only half glued. 

Socket savers FTW!


----------



## mordy

No luck folks.
  
 Scrolled through a bunch of 9 pin socket savers for sale. So far all are 27.5 mm wide and too wide to fit inside the decorative ring. Since it took me a week to put together a Vector adapter that I took apart, I would not entertain the idea of opening up the MKIII and put it together again.


----------



## TrollDragon

mordy said:


> No luck folks.
> 
> Scrolled through a bunch of 9 pin socket savers for sale. So far all are 27.5 mm wide and too wide to fit inside the decorative ring. Since it took me a week to put together a Vector adapter that I took apart, I would not entertain the idea of opening up the MKIII and put it together again.


 
  
 Well then mordy

 All you need to do is buy a pair of socket extenders that are bolted together. Such as this one here (It was the first on that showed up)
 http://www.ebay.com/itm/9-pin-tube-amp-tester-socket-savers-can-be-unbolted-/400653261220
  
 Remove the bolt, cut the pins to the size you need and wrap a piece of tape around the solder parts. or shrink tube that is not shrunk too much so it bends the pins or a little hot glue to cover up the exposed solder tabs.
  
 What ever works to keep it from shorting out against that ring.


----------



## MIKELAP

mordy said:


> No luck folks.
> 
> Scrolled through a bunch of 9 pin socket savers for sale. So far all are 27.5 mm wide and too wide to fit inside the decorative ring. Since it took me a week to put together a Vector adapter that I took apart, I would not entertain the idea of opening up the MKIII and put it together again.


 
 Hey Mordy took the faceplate off and its like TD said theres at least 2 small screws holding the rings .


----------



## samtheman

just ordered a pair of these socket savers:
  
 http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=160622385954&ssPageName=ADME:L:OC:IE:3160
  
 Hoping they will be small enough in diameter to allow them inside the rings!


----------



## mordy

Hi TD and Mikelap,
  
 Thanks for the suggestions and help.
  
 Do you think these will work, i.e. can be unbolted?
  
 http://www.ebay.com/itm/4pc-9PIN-Bakelite-vaccum-TUBE-SOCKET-SAVER-base-FOR-12AX7-12AU7-ECC82-ECC83-amps-/251473065996?pt=Vintage_Electronics_R2&hash=item3a8cf6780c


----------



## TrollDragon

mordy said:


> Hi TD and Mikelap,
> 
> Thanks for the suggestions and help.
> 
> ...


 
 Those look like they can for sure!


----------



## mab1376

mordy said:


> Hi TD and Mikelap,
> 
> Thanks for the suggestions and help.
> 
> ...


 
 maybe you can reach the screws from the holes for the gain jumpers with a screwdriver?


----------



## mordy

_maybe you can reach the screws from the holes for the gain jumpers with a screwdriver?_
  
 From what I remember from the pictures of the circuit boards in the MKIII there are several boards one above another so I don't think that this is possible.
  
 http://www.littledot.net/forum/viewtopic.php?f=9&t=815


----------



## TrollDragon

No there is just one board and it is a whole lot of fun to get in and out. You have to bring it forward halfway to unsolder the front heater wires, then back halfway to get the other wires. After that you can slide it out around the transformer wires. Front and Back panels have to be removed. 4 screws on top of the chassis hold the board in.


----------



## mordy

Hi TD,
  
 Thank you for clarifying the board layout. I don't feel that I am proficient enough to tackle the task of removing the circuit board.
 Waiting to hear from China if the adapter set above can be unbolted - the one adapter I have (different) is riveted.


----------



## i luvmusic 2

hope this help if you recall this picture i posted awhile back and you can take apart and put back the 9 pin adapter alot easier than the Vector(see the 9 pin adapter installed in MK III)


----------



## mordy

Since I want to use octal tubes it seems to me that the adapters for octals are wider and will not fit inside the ring.


----------



## gibosi

mordy said:


> Since I want to use octal tubes it seems to me that the adapters for octals are wider and will not fit inside the ring.


 
  
 I think the easy and ugly solution is two adapters plugged together. The first adapter, the ones you referenced, are simple socket savers, which would act as "risers" to essentially move the "base" of the LD socket up above the rings. You don't have to take them apart. Just plug them in.
  
 http://www.ebay.com/itm/4pc-9PIN-Bakelite-vaccum-TUBE-SOCKET-SAVER-base-FOR-12AX7-12AU7-ECC82-ECC83-amps-/251473065996?pt=Vintage_Electronics_R2&hash=item3a8cf6780c
  
 And then you would have the octal to 9-pin adapters, with 9-pin on the bottom and octal on top, to allow the use of 6SN7s. Just plug them into the first adapters and you should be good to go.


----------



## TrollDragon

Whoo Hoo...
It will look like the "Rocket to Russia", or MIKELAP's "Nuclear Stacks", my "Tower of Power" or ILM2's "Apple Antlers"

I just love it!


----------



## TrollDragon

Or just pick up a MK9 and roll all the octals you want...


----------



## MIKELAP

trolldragon said:


> Or just pick up a MK9 and roll all the octals you want...


 
 Man i swear your a mind reader was checking the mk9 this instant .Tempting   . Look at those tubes burn wow !


----------



## MIKELAP

trolldragon said:


> Whoo Hoo...
> It will look like the "Rocket to Russia", or MIKELAP's "Nuclear Stacks", my "Tower of Power" or ILM2's "Apple Antlers"
> 
> I just love it!


 
 Reach for the sky!


----------



## gibosi

trolldragon said:


> Or just pick up a MK9 and roll all the octals you want...


 
  
 But.... Then we would have to go out and buy new adapters to run all of our favorite 6AK5s!!


----------



## MIKELAP

gibosi said:


> But.... Then we would have to go out and buy new adapters to run all of our favorite 6AK5s!!


 
 Good one


----------



## mordy

> But.... Then we would have to go out and buy new adapters to run all of our favorite 6AK5s!!


 
  
 Very funny!


----------



## i luvmusic 2

any specific type and brand of adhesive you guys used for your copper adapters?THANKS!


----------



## TrollDragon

i luvmusic 2 said:


> any specific type and brand of adhesive you guys used for your copper adapters?THANKS!


Solder for the pipe and Hot Glue or JB Weld Kwik for the 7 pin connectors.

JB Weld is permanent, and the Kwik stuff gives you 1 minute of mix time and 5 minutes till mostly set. Leave it overnight and you can file or drill it as you like, I've seen intake manifolds on small engines repaired with the stuff.


----------



## MIKELAP

i luvmusic 2 said:


> any specific type and brand of adhesive you guys used for your copper adapters?THANKS!


 
 For the pin part of the adapter i use hot glue to bond   the pin staightner  to ceramic socket                                             
 And to the ceramic socket i use contact glue but use shrink wrap which i glue also  and so far everything is still ok  or JB weld it                                                               
 But for the socket that holds the tube i JB weld the socket to the copper chassis


----------



## i luvmusic 2

trolldragon said:


> Solder for the pipe and Hot Glue or JB Weld Kwik for the 7 pin connectors.
> 
> JB Weld is permanent, and the Kwik stuff gives you 1 minute of mix time and 5 minutes till mostly set. Leave it overnight and you can file or drill it as you like, I've seen intake manifolds on small engines repaired with the stuff.


 
  
  


mikelap said:


> For the pin part of the adapter i use hot glue to bond   the pin staightner  to ceramic socket
> And to the ceramic socket i use contact glue but use shrink wrap which i glue also  and so far everything is still ok  or JB weld it
> But for the socket that holds the tube i JB weld the socket to the copper chassis


 
 THANK YOU!JB weld should stick to plastic (Amphenol Octal socket)and copper right?


----------



## TrollDragon

i luvmusic 2 said:


> THANK YOU!JB weld should stick to plastic (Amphenol Octal socket)and copper right?


 

 Yes it will, for best results rough up the plastic and copper with some coarse sandpaper before using JB Weld, it helps the epoxy to stick better.


----------



## TrollDragon

Recieved an electro-harmonix 6922EH today in a little tube hybrid amp I am going to review...

  

 miuaudio MKTP1, I'll have to see if it will take a 6H9C once it comes apart...


----------



## mab1376

hypnos1 said:


> Well done mab...indirectly you have me sleeping a _little_ better at night as finally, at last_,_ I have incontrovertible proof of my insanity - against all gibosi's sensible advice to try some cheaper 6SN7s first (sorry g!), I have bitten the bullet and gone for some Psvane CV181-T MKIIs (supposedly a step up from the Shuguang CV181-Z). If they come near (or even surpass?) your findings, I shall be a happy chappie...at least I will have achieved the _look_ I seek...But , of course, it's very much down to how things partner each other, so I live in hope (not to mention patience...ie that darned _slow boat_!).
> And I now realise it's not _you_ I should blame for leading me astray - 'tis thou MORDY shouldst take the blame, viz your post saying things had gone quiet, and inciting to 'wake things up'!!.(Well, I can't blame _myself_ now can I?!).
> 
> Perhaps you will be trying some of gibosi's musings on different 6SN7s as power tubes -  or are you now happy enough as things are?...
> We wait with baited breath!...


 
  
 Spotted this is the MK VI+ thread, jealous?


----------



## hypnos1

mab1376 said:


> Spotted this is the MK VI+ thread, jealous?


 
  
 Hey mab, what are you trying to do to me? All those curves are just _too_ much for a poor, ageing lothario! (who am I kidding...those were the days lol - well, I _was_ an officer on the 'Princess' ships out of LA for some years...enough said?!!).
  
 I must admit I don't know if I prefer the looks of those Shuguang CV181-Zs over the Psvanes winging their way (hopefully) to me...perhaps I should get BOTH...now don't tempt me again, _please_!
 Naturally, I shall post a photo or 2 _when_ they arrive, and you can give me your (honest?) opinion...
  
 And as for those - I presume - 6AS7Gs behind...what a shame we can't use them in our MKIII or IV. OR the 6080s...Both seem to be available for (almost) peanuts.
  
 Mind you, methinks I prefer my curves to be on the 'small but beautifully-built' lines...those powers look BIG!!


----------



## mab1376

hypnos1 said:


> Hey mab, what are you trying to do to me? All those curves are just _too_ much for a poor, ageing lothario! (who am I kidding...those were the days lol - well, I _was_ an officer on the 'Princess' ships out of LA for some years...enough said?!!).
> 
> I must admit I don't know if I prefer the looks of those Shuguang CV181-Zs over the Psvanes winging their way (hopefully) to me...perhaps I should get BOTH...now don't tempt me again, _please_!
> Naturally, I shall post a photo or 2 _when_ they arrive, and you can give me your (honest?) opinion...
> ...


 
  
 i believe they're 6as7g's, the 5998's also have a similar bottle but got for about $125 a pop and are pretty rare now the 7236 is supposedly the cream of the crop and the same size bottle as the 6080.
  
 you can use them on the MK 9 though. 
	

	
	
		
		

		
		
	


	




 which is basically SE version and half of an MK VI+.
  
 I really do look forward to seeing your finished product, and i hope they sound as good as they look!


----------



## hypnos1

mab1376 said:


> i believe they're 6as7g's, the 5998's also have a similar bottle but got for about $125 a pop and are pretty rare now the 7236 is supposedly the cream of the crop and the same size bottle as the 6080.
> 
> you can use them on the MK 9 though.
> 
> ...


 
  
 Hey...you tryin' to tempt me with a MK9 now?. Is there no end to your perfidy, mab?! (But keep it up, lol!!).
  
 And boy, am I hoping too!...


----------



## Oskari

mab1376 said:


> i believe they're 6as7g's


 
  
 Yeah, Russian 6AS7G equivalents. You can actually see the =C= symbol of Svetlana in the photo.


----------



## MIKELAP

hypnos1 said:


> Hey...you tryin' to tempt me with a MK9 now?. Is there no end to your perfidy, mab?! (But keep it up, lol!!).
> 
> And boy, am I hoping too!...


 
       Pictures we need pictures ahhhhhhhh !!!   Aint that sweet !


----------



## hypnos1

mikelap said:


> Pictures we need pictures ahhhhhhhh !!!   Aint that sweet !


 
  
 So, MIKE, now YOU'RE trying to tempt me, eh? Shame on you...would you kick a guy when he's down?
	

	
	
		
		

		
		
	


	




 
  
  
 ps. Those 6080s could almost tempt me away from the curves!...


----------



## mordy

Nobody can accuse me of catering to aesthetics, what with my spiderweb of wires and adapters surrounding my MKIII. What matters to me is the sound. Does anybody know if the MK9 sounds significantly better than an up-to-date tube modded MKIII with your favorite tubes (and I don't mean 6AK5 tubes)?
  
 Does a MKVI  (which I understand essentially is a double MK9)  sound so much better?


----------



## gibosi

hypnos1 said:


> So, MIKE, now YOU'RE trying to tempt me, eh? Shame on you...would you kick a guy when he's down?
> 
> 
> 
> ...


 
  
 And just to muddy up the waters a bit more...  
  
 As the ECC40s are essentially 6SN7s, these too could be used as output tubes. The very expensive and highly sought-after ECC32, ECC33 and ECC34 differ significantly from the 6SN7, whereas in most cases, the ECC40 is a drop-in replacement, requiring only a different socket. So if you have ever wondered what an Amperex, La Radiotechnique, or Valvo 6SN7 might sound like, roll some Holland-made, French-made or German-made ECC40s and then you will know.   
  
 Actually, Philips did not acquire the Amperex brand until 1955, and it seems that Holland-made ECC40s never carried the Amperex label. But in the end, I believe it is perfectly acceptable to call Holland-made ECC40 tubes "Amperex."
  
 (Apparently, the ECC40 was also manufactured in Britain, but the only one I have seen was manufactured in 1978, and as I tend to avoid tubes manufactured that late in the game, I passed....)
  
 A 1952 "Amperex" ECC40 / 6SN7


----------



## MIKELAP

hypnos1 said:


> So, MIKE, now YOU'RE trying to tempt me, eh? Shame on you...would you kick a guy when he's down?
> 
> 
> 
> ...


 
 To be honest might pull the trigger on a Woo Audio2 tonight with 6AS7 also 6DJ8 and others man it's not easy decisions decisions!


----------



## hypnos1

mikelap said:


> To be honest might pull the trigger on a Woo Audio2 tonight with 6AS7 also 6DJ8 and others man it's not easy decisions decisions!


 
  
 Now it's MY turn to play the tempter...go for it MIKELAP, and let us know how it compares!
  
 GOOD LUCK


----------



## hypnos1

gibosi said:


> And just to muddy up the waters a bit more...
> 
> As the ECC40s are essentially 6SN7s, these too could be used as output tubes. The very expensive and highly sought-after ECC32, ECC33 and ECC34 differ significantly from the 6SN7, whereas in most cases, the ECC40 is a drop-in replacement, requiring only a different socket. So if you have ever wondered what an Amperex, La Radiotechnique, or Valvo 6SN7 might sound like, roll some Holland-made, French-made or German-made ECC40s and then you will know.
> 
> ...


 
  
 Hi gibosi.
  
 Yes indeed...once again SO many tubes to try, so little time (not to mention money!). These ECC40s certainly sound interesting - something for MY backburner, methinks!
  
 Cheers (and good night!)


----------



## i luvmusic 2

trolldragon said:


> Yes it will, for best results rough up the plastic and copper with some coarse sandpaper before using JB Weld, it helps the epoxy to stick better.


 
 THANK YOU!


----------



## mordy

What is the difference between an 6FQ7/6CG7 tube and the ECC40? As I understand it the 6FQ7/6CG7 tube was a replacement for the 6SN7 in a smaller envelope.


----------



## Oskari

gibosi said:


> Actually, Philips did not acquire the Amperex brand until 1955, and it seems that Holland-made ECC40s never carried the Amperex label. But in the end, I believe it is perfectly acceptable to call Holland-made ECC40 tubes "Amperex."


 
  
 Personally I think that one shouldn't. It would be accurate to call something Amperex if that something was made by Amperex or branded by Amperex. A tube branded Philips Miniwatt made by Philips in a Dutch Philips factory has zero connection to Amperex. I admit that this is a pet peeve of mine.


----------



## gibosi

oskari said:


> Personally I think that one shouldn't. It would be accurate to call something Amperex if that something was made by Amperex or branded by Amperex. A tube branded Philips Miniwatt made by Philips in a Dutch Philips factory has zero connection to Amperex. I admit that this is a pet peeve of mine.


 
  
 And I accept this. 
  
 Personally, I am far more focused on factory than on brand. And therefore, in my mind for example, Amperex labeled ECC88s made in England's Blackburn factory are "Amperex" in name only. Further, to call them "Amperex" is downright confusing. Again, my focus is on the factory. But I often find it helpful, when talking to others who are more focused on brand, to refer to Holland-made Philip's tubes as Amperex, even though it is not technically correct.
  
 So of course the picture of the Philips Miniwatt ECC40 I posted above is not really an Amperex. But calling it such can be helpful to those who don't understand just how complex and convoluted the Philips manufacturing conglomerate actually was.
  
 Cheers.


----------



## gibosi

mordy said:


> What is the difference between an 6FQ7/6CG7 tube and the ECC40? As I understand it the 6FQ7/6CG7 tube was a replacement for the 6SN7 in a smaller envelope.


 
  
 To my knowledge, the primary difference is that Philips never made 6SN7s, 6FQ7s or 6CG7s. And American manufacturers never made ECC40s. In terms of use and function, they are essentially the same tube. Technically, the 6FQ7/6CG7 are 9-pin miniature (B9A base) tubes and the ECC40 are 8-pin (Rimlock) miniatures (B8A base). So again, the same tube, different bases. And therefore, the only reason to try ECC40s is if you want to experience 6SN7s with a Philips flavor.


----------



## Oskari

gibosi said:


> And I accept this.
> 
> Personally, I am far more focused on factory than on brand. And therefore, in my mind for example, Amperex labeled ECC88s made in England's Blackburn factory are "Amperex" in name only. Further, to call them "Amperex" is downright confusing. Again, my focus is on the factory. But I often find it helpful, when talking to others who are more focused on brand, to refer to Holland-made Philip's tubes as Amperex, even though it is not technically correct.
> 
> ...


 
  
 I agree on all points but wish to note that we should strive to educate rather than perpetuate the "lie".


----------



## Oskari

mordy said:


> What is the difference between an 6FQ7/6CG7 tube and the ECC40? As I understand it the 6FQ7/6CG7 tube was a replacement for the 6SN7 in a smaller envelope.


 
  
 You could see them as slightly different answers to the same question, i.e., miniaturization.
  


gibosi said:


> To my knowledge, the primary difference is that Philips never made 6SN7s, 6FQ7s or 6CG7s.


 
  
 Philips did make 6SN7GTs; Mullard did not, they had their ECC3Xs.


----------



## gibosi

oskari said:


> Philips did make 6SN7GTs; Mullard did not, they had their ECC3Xs.


 
  
 Obviously, I still have much to learn. 
  
 In the past, whenever I saw a Philips-branded 6SN7GT. I just assumed that it was an American rebrand, I often see Brimars, but as this company was created to manufacture American tubes for the British market (*Bri*tish *M*anufactured *A*merican *R*adio), this is to be expected, and I don't think Brimar was part of Philips? While I certainly don't see them very often, I will definitely spend a little more time checking out any Philips 6SN7s I see in the future.


----------



## Oskari

gibosi said:


> I don't think Brimar was part of Philips?


 
  
 It wasn't. It was part of STC until sold to Thorn in 1960. Thorn then merged their tube interests with those of AEI in 1961.
  


> While I certainly don't see them very often, I will definitely spend a little more time checking out any Philips 6SN7s I see in the future.


 
  
 You'll find out that, in addition to Philips, many were made by MBLE in Brussels.


----------



## gibosi

Found and purchased a Sylvania (DELCO brand) metal base 6NS7W for peanuts, as the base had completely split and come loose. Notice that it looks similar to the much later coin-base 6SN7s. This suggests to me that when removing these tubes from their sockets, it is perhaps best to grab them by the black phenolic bottom rather than the metal wrapping.
  

  
 I figure that this shouldn't be all that hard to repair. The original brown mastic is rather thick so I think this calls for a very thin glue. I have read that clear nail polish works well for resecuring phenolic bases, but maybe a couple drops of superglue would do the trick. Any suggestions?
  

  
 But in the meantime, a simple twist tie works very well and it has the added benefit of fitting in with the "flying wire" aesthetic of my current rig. And it sounds great!


----------



## TrollDragon

I would leave the metal off myself, adds a unique flavor to the tube.


----------



## MIKELAP

Well its a done deal i am the proud owner of a gorgeous Woo Audio 2 tube amp .My treat picture wise of course lol.


----------



## TrollDragon

Congratulations MIKELAP!

That is a gorgeous amp and will be incredible with the HD800's.


----------



## MIKELAP

trolldragon said:


> Congratulations MIKELAP!
> 
> That is a gorgeous amp and will be incredible with the HD800's.


 
 Thanks alot TD it is gorgeous lol will get it Monday or Tuesday. with already upgraded tubes plus my 6DJ8 will work with this amp thats even better.


----------



## gibosi

mikelap said:


> Well its a done deal i am the proud owner of a gorgeous Woo Audio 2 tube amp .My treat picture wise of course lol.


 
  
 Congratulations! Everything I have read about this amp suggests that is crazy good! 
  
 But... Does this mean we won't see you here anymore? (((((


----------



## gibosi

trolldragon said:


> I would leave the metal off myself, adds a unique flavor to the tube.


 
  
 Yes, it does look pretty neat without the metal, but I worry about the black phenolic base coming loose as I try to wriggle the tube out the socket. The metal ring does have four interlocking tabs securing it to the black phenolic base which makes it a little easier to handle. But perhaps I am being a bit overprotective. lol


----------



## MIKELAP

gibosi said:


> Congratulations! Everything I have read about this amp suggests that is crazy good!
> 
> But... Does this mean we won't see you here anymore? (((((


 
 The only thing it means is that my pc station his going to be even more cluttered beside that its bussiness as usual LEAVE MY BUDDY'S NO WAY !!!!


----------



## TrollDragon

gibosi said:


> Yes, it does look pretty neat without the metal, but I worry about the black phenolic base coming loose as I try to wriggle the tube out the socket. The metal ring does have four interlocking tabs securing it to the black phenolic base which makes it a little easier to handle. But perhaps I am being a bit overprotective. lol


JB Weld is good to 500F and will withstand 600F for 10 Minutes... Mix some up and put it on the inside of the metal on both sides of the split you can put a little on the opposite side as well. Attach the ring, align it nicely and clamp it, wipe off the excess from the crack and in 24 hours you will not get that ring off again. 

You mentioned Crazy glue before, the only thing that stuff is good for is gluing fingers together... I hate the stuff, the bond shatters if dropped or hit after it sets.


----------



## TrollDragon

mikelap said:


> LEAVE MY BUDDY'S NO WAY !!!!


Famous last words...

Once you start hanging around with the Woo crowd in the Summit-Fi threads, upgrading your DAC and cables and Tubes... You won't have time for us in the little Chi-nee amp thread where copper and flying wires are the order of the day.


----------



## gibosi

mikelap said:


> ....LEAVE MY BUDDY'S NO WAY !!!!


 
  
 I hope so... But like TD says... After a basking in Summit-Fi land for awhile, "copper and flying wires" may well seem "tres gauche" lol
  
 But back to the tubes! 
  
 For those who might be interested in ECC40s, it is back to the misleading and confusing world of Philips tubes, similar to the ECC88s.....
  
 Here is a listing for a Siemens ECC 40, "made in Germany". But the code indicates this tube was manufactured in Chartres, France (±), likely in the 1970s.
  
 http://www.ebay.com/itm/Siemens-ECC-40-Elektronenrohre-/201053058472?pt=DE_TV_Video_Audio_Elektronenr%C3%B6hren_Valves&hash=item2ecfb235a8
  
 And here is another listing: 2 x ECC40 / CV3884 MINIWATT DARIO made in HOLLAND. But the code suggests these tubes were manufactured in Suresnes, France (F), in 1948. (It is not at all clear what "60" refers to....)
  
 http://www.ebay.com/itm/2-x-ECC40-CV3884-MINIWATT-DARIO-made-in-HOLLAND-Valve-Tube-Rohre-/251475549801?pt=Accessori_per_Radioamatori&hash=item3a8d1c5e69


----------



## MIKELAP

trolldragon said:


> Famous last words...
> 
> Once you start hanging around with the Woo crowd in the Summit-Fi threads, upgrading your DAC and cables and Tubes... You won't have time for us in the little Chi-nee amp thread where copper and flying wires are the order of the day.


----------



## gibosi

trolldragon said:


> JB Weld is good to 500F and will withstand 600F for 10 Minutes... Mix some up and put it on the inside of the metal on both sides of the split you can put a little on the opposite side as well. Attach the ring, align it nicely and clamp it, wipe off the excess from the crack and in 24 hours you will not get that ring off again.
> 
> You mentioned Crazy glue before, the only thing that stuff is good for is gluing fingers together... I hate the stuff, the bond shatters if dropped or hit after it sets.


 
  
 Thanks for the tip. I don't have any JB Weld, but it sure sounds like it would be a very good glue to have on hand, for this and many other uses.
  
 Cheers


----------



## henree

Is there an ultimate tube for the Hybrid Little Dot +. I have about a dozen pairs. But I only listen to the Sylvania Gold Brand 408. And Mullard 8083. Should I stop looking or is there better tubes for the Dot + out there.
 Really like warmth, musicality and soundstage.


----------



## kvtaco17

henree said:


> Is there an ultimate tube for the Hybrid Little Dot +. I have about a dozen pairs. But I only listen to the Sylvania Gold Brand 408. And Mullard 8083. Should I stop looking or is there better tubes for the Dot + out there.
> Really like warmth, musicality and soundstage.


 
 the best tube is the one you like the most. Out of things that work in the LD without modification the tall bottle 6HM5 are one of the best tubes available (the yugo and Sylvania's seem to be the favorites)
  
 IF you are willing to mod/wire up some adapters there's a whole new world of better tubes to be tried...


----------



## lljayll

mikelap said:


> Thanks alot TD it is gorgeous lol will get it Monday or Tuesday. with already upgraded tubes plus my 6DJ8 will work with this amp thats even better.


 
 Congratulations Mike.


----------



## henree

kvtaco17 said:


> the best tube is the one you like the most. Out of things that work in the LD without modification the tall bottle 6HM5 are one of the best tubes available (the yugo and Sylvania's seem to be the favorites)
> 
> IF you are willing to mod/wire up some adapters there's a whole new world of better tubes to be tried...


 
 What are the sonic characteristics of the 6hm5? And what kind of adaptor would I need to use it?


----------



## kvtaco17

henree said:


> What are the sonic characteristics of the 6hm5? And what kind of adaptor would I need to use it?


 
 they are stock compatible in EF95 mode
  
 http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/1140#post_9392055
  
 They are very spacious and detailed with good dynamics... VS the 6AK5 family of tubes its a big step up... I had the Mullard 8083 at one point and greatly preferred 6HM5, 6DT6, 6AV6 heck even the EH90.
  
 The point being is the traditional tubes these amps were designed around may be good... but there are far better... start with the post I linked above as a reference and check out all the tube reviews myself and others have done throughout this thread. I'd limit your searches to the 6HM5, 6DT6 and 6AV6.


----------



## henree

kvtaco17 said:


> they are stock compatible in EF95 mode
> 
> http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/1140#post_9392055
> 
> ...


 
 Just to follow up. 6HM5, 6DT6 and 6AV6 these types will work without any type of modification on the Dot +?


----------



## CollectoR13

Hello again guys! 
Im in the last steps of completing my adapter, picture tutorial follows  
Do you know what setting I should set to use the c3g-s? Ef95 or ef92?
Does it make a big difference?


----------



## gibosi

collector13 said:


> Hello again guys!
> Im in the last steps of completing my adapter, picture tutorial follows
> 
> 
> ...


 
  
 I do not recall exactly how the pins are strapped in order to use c3gs, but as best I can remember, you are using pin 7, and if so, it would make a major difference. In the ef92 setting you would be connecting pin 7 to the anode (pin 5). But I believe in your adapter, you are connecting pin 7 to the cathode. So...  connecting the cathode directly to the anode is definitely not something you want to do. Again, as best I can recall, you are making the c3gs look like a ef95, so I think you would use that setting.
  
 But again, I haven't tried to use a c3s, so I encourage you to study the pins to see exactly how they are connected, and then figure out if pin 7 should, or should not, be connected to pins 5 and 6.
  
 Good luck!


----------



## MIKELAP

henree said:


> Just to follow up. 6HM5, 6DT6 and 6AV6 these types will work without any type of modification on the Dot +?


 
 6HM5 use EF95 setting, 6DT6 use EF91-92 or EF95 PLUS 1/7 wire mod and 2/7 wire mod (page 77) .Finally the 6AV6  tube uses EF91-92 setting BUT PINS 5 AND 6 HAVE TO BE CUTOFF AND ELECTRICAL TAPE APPLIED ON WHERE THE PINS USE TO BE TO PREVENT ANY CONTACT here are  few pictures of the 6AV6 mod


----------



## MIKELAP

lljayll said:


> Congratulations Mike.


 
 ahhhhh,what goes around comes around my friend .


----------



## hypnos1

mikelap said:


> Well its a done deal i am the proud owner of a gorgeous Woo Audio 2 tube amp .My treat picture wise of course lol.


 
  
 WELL DONE MIKE! ... So, mon ami, you've beaten me to some nice curvy tubes? You are definitely off my Xmas card list!
  
 Enjoy your new level in headfi land, and look forward to your impressions on how our humble LDs compare (I feel the green-eyed monster lurking over my shoulder!..).
  
 Sante


----------



## henree

mikelap said:


> 6HM5 use EF95 setting, 6DT6 use EF91-92 or EF95 PLUS 1/7 wire mod and 2/7 wire mod (page 77) .Finally the 6AV6  tube uses EF91-92 setting BUT PINS 5 AND 6 HAVE TO BE CUTOFF AND ELECTRICAL TAPE APPLIED ON WHERE THE PINS USE TO BE TO PREVENT ANY CONTACT here are  few pictures of the 6AV6 mod
> 
> Awesome thanks. I will find some 6hm5 tubes. Since they require no mods. I had no idea there were ways to explore so many more tube families.  Are new tubes still being made today? Do you forsee some company producing new vacuum tubes for the audiofille consumers?


----------



## hypnos1

collector13 said:


> Hello again guys!
> Im in the last steps of completing my adapter, picture tutorial follows
> 
> 
> ...


 
  
 Hi there CR13.
  
 Look forward to seeing your handiwork on those adapters...hope you haven't encountered _too_ many tricky moments!
  
 I presume you linked as per my post on page 312 (EF95 setting), and I have had no problems at all linking C3g pins 2 and 7 together...
  
 Also look forward to your impressions of the C3GSs - remember they continue to improve with 30+ hours


----------



## CollectoR13

So, the adapter is half done, its usable but not pretty, have to tidy up the wires and such...  
But I can already say I am really impressed! 
I got the siemens C3g-s as driver and sylvania 6sn7gt (bad boys???) as power tube and i have to say that the effort is more than worth it. 
This combinatiom really sings in my setup! 
(Btw i wired everything with silver plated solid core copper...) 
So i can encourage every ld owner to try these great tubes and build (or buy?) adapters!


----------



## hypnos1

henree said:


> Is there an ultimate tube for the Hybrid Little Dot +. I have about a dozen pairs. But I only listen to the Sylvania Gold Brand 408. And Mullard 8083. Should I stop looking or is there better tubes for the Dot + out there.
> Really like warmth, musicality and soundstage.


 
  
 As already mentioned, there are tubes that will perform much better even than the (very good) 6HM5. If you are prepared to do some _relatively_ simple mod work, the 6SN7 family are giving really good results by all accounts (my own magic has come from the Siemens C3g (and especially C3GS) tubes - but require making your own adapters, covered by myself a while back, and now by CollectoR13). IF you are seriously interested, I suggest you look back over recent posts by gibosi et al for help re the 6SN7...a bit of a marathon, yes, but VERY interesting/informative.
 Whatever your choice, welcome to the land of magical transformation of a humble collection of units that can punch WELL above their weight!..(given a bit of investment in time and effort - most of which has already been done by a group of wonderfully creative and _very_ helpful guys. And without the need to spend _too _much money...).


----------



## hypnos1

collector13 said:


> So, the adapter is half done, its usable but not pretty, have to tidy up the wires and such...
> 
> 
> 
> ...


 
  
 WELL DONE CR13!...so glad you've got there without any mishaps. I can assure you that you have only just _begun_ to hear what the C3GSs are capable of...can't wait to get your feedback a bit further down the road (especially as there's a lot of "stuff" needs burning in). Glad to hear also that the 6SN7s as power tubes are performing well - you really are trailblazing!
  
 A shame you didn't use pure (or sterling) silver wire, but that's just _my_ pet love (probably makes not a lot of difference, actually!! But then again...)
  
 Cheers!


----------



## gibosi

collector13 said:


> So, the adapter is half done, its usable but not pretty, have to tidy up the wires and such...
> 
> 
> 
> ...


 
  
 Sylvania 6sn7gt bad boys:  Tall bottles, bottom getter and 3-hole black T-plates manufactured from about 1950 to 1953. Those with 2-hole plates or top getter are not considered to be true "Badboys" and sound different, but eBay vendors often label them such....


----------



## CollectoR13

Thanks hypnos, very kind words. 
I look forward to some tube burn in, experienced it often enough to believe in it. 
Oh, and as you can read in my profile, I use to have kind of a budget setup, so I thought silver plated copper was resonable enough... 
I am only 17 years old, close to do my exams and have only a tight budget... 
All the gear I have I bought after saving cash month after month and I got several things for much, much lower price than new.
Hope that explains my choice  


And gibosi, I have to clarify, I think I was wrong. 
They are not bad boys, but rather these tubes in the link http://www.tubemaze.info/sylvania-6sn7gt-black-flat-plates/
But anyways, they sound brilliant!


----------



## kvtaco17

Quote:


mikelap said:


> 6HM5 use EF95 setting, 6DT6 use EF91-92 or EF95 PLUS 1/7 wire mod and 2/7 wire mod (page 77) .Finally the 6AV6  tube uses EF91-92 setting BUT PINS 5 AND 6 HAVE TO BE CUTOFF AND ELECTRICAL TAPE APPLIED ON WHERE THE PINS USE TO BE TO PREVENT ANY CONTACT here are  few pictures of the 6AV6 mod


 
  
 Thank you sir for responding for me... between traveling and working nights I've been pretty scarce around here...


----------



## kvtaco17

Look at what I scored locally here in Omaha today!
  
 a Mullard 6SN7, Gold Arrow 5692 and a Sylvania NOS 6SN7 button bottom.
  
 I am traveling and do not have my LD with me so it will be at least 3 weeks before I get to testing these.


----------



## TrollDragon

Nice score!

Three weeks... hope you have a sweet portable rig with you.


----------



## MIKELAP

kvtaco17 said:


> Thank you sir for responding for me... between traveling and working nights I've been pretty scarce around here...


 
 My pleasure if it helped you out . Theres  no rush anymore  time to take it easy for my part .


----------



## kvtaco17

trolldragon said:


> Nice score!
> 
> Three weeks... hope you have a sweet portable rig with you.


 
 I have my home theater PC, E17 and my K550's that I'm evaluating... so no... I need better cans lol
  
 They aren't bad cans... just not as good as I'd like... might keep them and throw a mod mic on them for gaming...


----------



## gibosi

collector13 said:


> And gibosi, I have to clarify, I think I was wrong.
> They are not bad boys, but rather these tubes in the link http://www.tubemaze.info/sylvania-6sn7gt-black-flat-plates/
> But anyways, they sound brilliant!


 
  
 I have yet to hear a Sylvania 6SN7 I don't like, so I am not at all surprised they sound brilliant! 
  
 And as my LD 1+ is an op amp hybrid, I am not able to try 6SN7s as output tubes, so I am a bit envious...   I am thinking I should get another amp so I can roll output tubes....   But for now, new headphones are a higher priority.


----------



## MIKELAP

gibosi said:


> I have yet to hear a Sylvania 6SN7 I don't like, so I am not at all surprised they sound brilliant!
> 
> And as my LD 1+ is an op amp hybrid, I am not able to try 6SN7s as output tubes, so I am a bit envious...   I am thinking I should get another amp so I can roll output tubes....   But for now, new headphones are a higher priority.


 
 OH !OH ! i see it coming again.:                THE EMPTY WALLET SYNDROME


----------



## gibosi

mikelap said:


> OH !OH ! i see it coming again.:                THE EMPTY WALLET SYNDROME


 
  
 lol.....  Well, my income tax refund was a little higher than I expected... and it's starting to burn a hole in my wallet...  What should I get?  lol


----------



## kvtaco17

gibosi said:


> lol.....  Well, my income tax refund was a little higher than I expected... and it's starting to burn a hole in my wallet...  What should I get?  lol


 
 LD MKVI+ or a WA6SE


----------



## MIKELAP

gibosi said:


> lol.....  Well, my income tax refund was a little higher than I expected... and it's starting to burn a hole in my wallet...  What should I get?  lol


 
 Thats exciting ! I would say go for the gusto we worked hard enough to get there .


----------



## gibosi

kvtaco17 said:


> LD MKVI+ or a WA6SE


 
  
 I would prefer to stay with 6SN7 and the 6AS7. My current investment in tubes is obviously a factor, as I already have a bunch of some of the best 6SN7s and ECC40s. Further, the 6AS7s are relatively cheap and many consider them to be one of the very best power tubes available, so the LD is more appealing to me than the Woo. However, I believe my tricked out Little Dot is good enough to warrant better headphones and so this is where I think I am heading.... 
  
 Edit: Oh, the LD VI+ uses 6H9C / 6SL7 rather than 6N8S / 6NS7, so scratch that one off the list....
 Edit2: Just discovered that even though it ships with 6SL7s, it was designed to accommodate 6SN7s as well, sacrificing only a little gain... so back on the list it goes.


----------



## kvtaco17

gibosi said:


> I would prefer to stay with 6SN7 and the 6AS7. My current investment in tubes is obviously a factor, as I already have a bunch of some of the best 6SN7s and ECC40s. Further, the 6AS7s are relatively cheap and many consider them to be one of the very best power tubes available, so the LD is more appealing to me than the Woo. However, I believe my tricked out Little Dot is good enough to warrant better headphones and so this is where I think I am heading....
> 
> Edit: Oh, the LD VI+ uses 6H9C / 6SL7 rather than 6N8S / 6NS7, so scratch that one off the list....
> Edit2: Just discovered that even though it ships with 6SL7s, it was designed to accommodate 6SN7s as well, sacrificing only a little gain... so back on the list it goes.


 

 Those edits were quick lol


----------



## TrollDragon

kvtaco17 said:


> I have my home theater PC, E17 and my K550's that I'm evaluating... so no... I need better cans lol
> 
> They aren't bad cans... just not as good as I'd like... might keep them and throw a mod mic on them for gaming...


That is interesting, before I picked up the German Maestro's as my closed can I asked HiFiGuy528 about a neutral pair of closed. He has the MB Quart version which was German Maestro's previous company, also his major recommendation was the AKG 550's. He likes them so much he has two pairs, I have not heard them but would like to one of these days. Are they to neutral for your liking?


----------



## TrollDragon

gibosi said:


> lol.....  Well, my income tax refund was a little higher than I expected... and it's starting to burn a hole in my wallet...  What should I get?  lol


WA5 LE with the ultra sweet 300B's and you can always sell off the 6SN7's on eBay to fund the Sophia Princesses you will just want to buy... 

A nice Eddie Current Zana Deux with those sweet 6C33C-B Mig Fighter tubes would be the ultimate.


----------



## gibosi

trolldragon said:


> WA5 LE with the ultra sweet 300B's and you can always sell off the 6SN7's on eBay to fund the Sophia Princesses you will just want to buy...
> 
> A nice Eddie Current Zana Deux with those sweet 6C33C-B Mig Fighter tubes would be the ultimate.


 
  
 lol... Yes, likely either or both are "ultimate", but the amount I got back from the tax collector won't get me anywhere near those prices...   And besides, I am much more comfortable with the notion of slow and orderly change rather than a revolution. 
  
 Further... at this point in time, I am in the market for a new pair of headphones, not a new amp. I believe my ugly little amp is good enough to justify new headphones... However, I don't believe my headphones are good enough to justify a new amp....


----------



## MIKELAP

trolldragon said:


> WA5 LE with the ultra sweet 300B's and you can always sell off the 6SN7's on eBay to fund the Sophia Princesses you will just want to buy...
> 
> A nice Eddie Current Zana Deux with those sweet 6C33C-B Mig Fighter tubes would be the ultimate.


 
 Hey TD always document what your talking about ,because you know a picture is worth a thousand words lol


----------



## kvtaco17

trolldragon said:


> That is interesting, before I picked up the German Maestro's as my closed can I asked HiFiGuy528 about a neutral pair of closed. He has the MB Quart version which was German Maestro's previous company, also his major recommendation was the AKG 550's. He likes them so much he has two pairs, I have not heard them but would like to one of these days. Are they to neutral for your liking?


 
 I actually think they sound good... good bass extension and mids... the treble is never biting or bright, it just seems like it is missing something. Decent imaging, sound stage and no bass bleed (these are not bass head cans by any means lol) I did have to modify the ear pads and bend the headband to get a good seal... without doing that they were not usable and sounded awful. If I can make these fit a little better (why couldn't AKG use the k/q7xx headbands?) I'll keep them.


----------



## kvtaco17

mikelap said:


> My pleasure if it helped you out . Theres  no rush anymore  time to take it easy for my part .


 
 Really thank you lol


----------



## TrollDragon

kvtaco17 said:


> I actually think they sound good... good bass extension and mids... the treble is never biting or bright, it just seems like it is missing something. Decent imaging, sound stage and no bass bleed (these are not bass head cans by any means lol) I did have to modify the ear pads and bend the headband to get a good seal... without doing that they were not usable and sounded awful. If I can make these fit a little better (why couldn't AKG use the k/q7xx headbands?) I'll keep them.


 

 Thanks for the sound info, yes I have read a lot about the fit issues. I'll really have to find a place to try these before I'd blind order them.


----------



## kvtaco17

trolldragon said:


> Thanks for the sound info, yes I have read a lot about the fit issues. I'll really have to find a place to try these before I'd blind order them.


 
 Amazon... so you can send em back if you hate them!


----------



## TrollDragon

kvtaco17 said:


> Amazon... so you can send em back if you hate them!


 

 Canada here... so the shipping back to Amazon with tracking would be a killer. I sent an Audioengine D1 (Great DAC, schiit amp) back to B&H without tracking through regular mail and had anxiety the whole time it was in transit that it wouldn't get lost or stolen...
  
 You 'mericans have a seriously great dealie with your country wide shipping and Amazon returns.


----------



## Oskari

kvtaco17 said:


> a Mullard 6SN7


 
  
 CCCP. Rebranded. Mullard did not make 6SN7s.


----------



## mordy

Hi,
  
 I have a problem - I am perfectly happy with my MKIII IR-8FQ7 set-up, and I don't feel the need to upgrade to a $2000 amp. Is something wrong with me?
  
 I agree that the Woos and Deuces look much nicer than my 1925 styling spider web amp, but to me it does not matter.
  
 Waiting for two adapters from China to try 6SN7 tubes as power tubes, but that's it for curiosity (meanwhile).


----------



## gibosi

I don't have a problem. (Or at least any that I am willing to discuss here! lol)
  
 I am not at all unhappy with my LD1+ MUSES02/6SN7 set-up. But that said, eventually, I would like to be able to roll output tubes instead of op amps. So I expect that I will purchase another amp someday, but not any time soon, and very fortunately for my wallet, it will not be necessary to spend $2000 to do this.


----------



## hypnos1

mab1376 said:


> I really do look forward to seeing your finished product, and i hope they sound as good as they look!


 
  
 Well mab, miracle of miracles - the Psvanes have arrived! And quicker from Hong Kong than Germany sometimes!
  
 So here are a couple of pics....they do tower over the C3GSs somewhat, but I prefer that to the "little" DRs behind....and I finally have my _curves!! _
  
 So how do they sound, I hear you ask? Given that they are supposed to be at their best after100 (yes, one hundred!) hours, all I can say is WOW! Straight out of the box, and with new bought adapters (NOT with my beloved silver wire, alas - YET), I seriously believe they have the potential to even surpass the 6N30P-DRs - and that's not wishful thinking. I was not expecting this AT ALL (especially at half the price...). Bass has even more weight; mids are even more present; nothing is compromising the magic of the C3GSs - just a slight edge to the upper end, but nowhere near as much as I would have expected given all is new. In other words I am totally blown away - already!!
  
 Will keep you posted...
  



  
  
 I'm in love...AGAIN...


----------



## mab1376

hypnos1 said:


> Well mab, miracle of miracles - the Psvanes have arrived! And quicker from Hong Kong than Germany sometimes!
> 
> So here are a couple of pics....they do tower over the C3GSs somewhat, but I prefer that to the "little" DRs behind....and I finally have my _curves!! _
> 
> ...


 
  
  
 Now i feel more fire to get the c3gs' and make the adapters.
  
 congrats! looks amazing!


----------



## Artsi

hypnos1 said:


>


 
 Now this is starting to look like a Tube Amplifier to me. Excellent!
  
 But there is still some way to go.

 ~15kg


----------



## MIKELAP

LD 4 looks great !


----------



## hypnos1

Thanks a lot guys for the encouraging messages...had been having a good few serious doubts up 'til now! But thankfully, they're all blown away...
  
 mab : I am sure the C3GSs are providing the real magic here, so if you get the chance, take the plunge!
  
 artsi : A real pleasure to get your approval also...but as for going 15kg...I'll pass on that one, thank you very much!
  
 mike : I still like your WA2, you lucky feller!
  
 Cheers (breathes a sigh of relief...- is there a smiley for such?!)


----------



## mordy

Hi Artsi,
  
 I assume this is your own amp design - which tubes are you using?


----------



## mab1376

hypnos1 said:


> Thanks a lot guys for the encouraging messages...had been having a good few serious doubts up 'til now! But thankfully, they're all blown away...
> 
> mab : I am sure the C3GSs are providing the real magic here, so if you get the chance, take the plunge!
> 
> ...


 
  
 I would like to build adapters like you did to clean up my amp since it's a mess with all these wires going to the vector adapters for my 6SU7 tube.
  
 Hopefully soon I'll have the patience and ambition to get it done. If i order the tubes I'll be on the hook to get it done once they tubes are on my desk staring at me.


----------



## Artsi

mordy said:


> Hi Artsi,
> 
> I assume this is your own amp design - which tubes are you using?


 
 Russian 1x 6N9S, 2x 6N8S, 2x 6N13S and one sylvania 6BY5GA. After photo 6N8S's have changed to older '65 model. It is stereo amplifier with headphone out too. First tube is for signal amplify only and second works as phase splitter too, so powertubes do things in push-pull.
  
 With this amp i can use pretty freely my 6SL7, 6SN7, 6BL7, 6BX7 and 6AS7 tubes.
  
 And it really is my own design, did not find quickly any similar schematics. Of course someone could have made same kind, since there have been ~60years time to do amplifier like this.


----------



## hypnos1

gibosi said:


> I have yet to hear a Sylvania 6SN7 I don't like, so I am not at all surprised they sound brilliant!
> 
> And as my LD 1+ is an op amp hybrid, I am not able to try 6SN7s as output tubes, so I am a bit envious...   I am thinking I should get another amp so I can roll output tubes....   But for now, new headphones are a higher priority.


 
  
 gibosi : hope you caught my post re the Psvanes...have some reflections after on what I think may be a couple of rather controversial/interesting? topics...but first, to perhaps shed a little more light on the 6SN7 as power tube quest, I'm glad you like the Sylvanias - I've a pair of VT231 on the way, which I believe are not far off the (real) "Bad Boys"? So I can't wait to see how they compare to the Psvane CV181-T MKII...
  
 And now for something that hopefully might be of interest also to anyone else who may be following this...
  
 FOLKS...After just 4hours (of the optimum 100!), these Psvanes are obviously going to easily surpass the 6N30P-DRs - which is generating some VERY strong feelings in me at the moment...over and above the euphoria!
  
 To tell the truth, for some time now I have been having serious doubts about -  (what I am now fairly convinced to be true) - the myth surrounding those Russian "Supertubes" (at SUPER prices).
 The first hint there may be something in it came from a forum post where someone (who seemed to know what he was talking about) actually rated the performance of the 'humble' 6H30Pi OVER the DR. At the time I thought it was down purely to personal preference...but now that I am hearing what these Chinese tubes are doing (admittedly not the cheapos), my suspicions are definitely looking more founded in fact ( to me anyway). I am quite sure the Sylvania VT231s will prove it beyond doubt...but we will see!...
  
 I am going to be generous in my disappointment, and put this down to SOLELY because of traditional partnering with less-than-ideal drivers, thereby making the DR _appear_ to be a "supertube", when in fact that was not really the case...
 Which brings me to the second 'myth' that I feel needs busting - ie that (in our LDs, at least), the power tubes do not have a great bearing on the final result...these Psvanes are _definitely_ disproving that one - already!!
  
 So, folks, I am convinced that the Meisters in this thread, through the relentless trial and error of tubes that were never envisaged at its outset, have hit upon some EXTREMELY interesting and RELEVANT pointers that go beyond the mere 'improvement' of what our units can achieve. And I honestly believe that although we have found drivers that can transform the sound we enjoy, the biggest advance will in fact lie in this area of power tubes...even if only to save just 1 person from being 'robbed' by the "Supertube" myth...I welcome any (informed) challenge to my rant...and I am quite sure my suspicions will be upheld by others who tread this route to alternative power tubes.
  
 Rant over...back to seeing how the burn-in is going...
  
 Cheers, and HAPPY ROLLING everyone.


----------



## mab1376

hypnos1 said:


> gibosi : hope you caught my post re the Psvanes...have some reflections after on what I think may be a couple of rather controversial/interesting? topics...but first, to perhaps shed a little more light on the 6SN7 as power tube quest, I'm glad you like the Sylvanias - I've a pair of VT231 on the way, which I believe are not far off the (real) "Bad Boys"? So I can't wait to see how they compare to the Psvane CV181-T MKII...
> 
> And now for something that hopefully might be of interest also to anyone else who may be following this...
> 
> ...


 
  
 I'm glad i never splurged on them, because these 6SN7GTB's that are only about $25 (+35 for the adapters) each are very pleasing as power tubes.
  
 I hope we can find an even better and ideally, even cheaper, alternatives to the super tubes and their ridiculous pricing.


----------



## CollectoR13

I have to say that I also think that the 6sn7 is the superior tube. 
In my setup its simply a huge step up from the 6n30s...
Sound wise I experienced more space and ambiance (soundstage) , better control and dynamics and a definitly cleaner top end with better extension with the C3gs.
And I think, as you are able to buy those pre made adapters, go for it! 
Unfortunatly the seller did not ship to germany, where I live, so I had to build my own adapters... 

Btw, I did not forget to write the tutorial, I am just very busy these days, sorry


----------



## hypnos1

mab1376 said:


> I'm glad i never splurged on them, because these 6SN7GTB's that are only about $25 (+35 for the adapters) each are very pleasing as power tubes.
> 
> I hope we can find an even better and ideally, even cheaper, alternatives to the super tubes and their ridiculous pricing.


 
  
 I'm glad too, mab...as I mentioned, if we can at least save _someone_ from being fleeced, so much the better!
 As for even better/cheaper - where on Earth do we go from here?! Looks like the only real contenders are, unfortunately, a no-go for our LDs - up to MKIV at least...but who knows?!...
  


collector13 said:


> I have to say that I also think that the 6sn7 is the superior tube.
> In my setup its simply a huge step up from the 6n30s...
> Sound wise I experienced more space and ambiance (soundstage) , better control and dynamics and a definitly cleaner top end with better extension with the C3gs.
> And I think, as you are able to buy those pre made adapters, go for it!
> ...


 
  
 Glad you have also found the 6SN7 a good power tube, CR13...
  
 By the way, re your previous post, may I say DOUBLY well done given your situation - and I shall let you off for not having used real silver wire...perhaps in the future, when you have made your fortune?!!
  
 Cheers.


----------



## gibosi

hypnos1 said:


> FOLKS...After just 4hours (of the optimum 100!), these Psvanes are obviously going to easily surpass the 6N30P-DRs - which is generating some VERY strong feelings in me at the moment...over and above the euphoria!


 
  
 I am not entirely surprised. To my way of thinking, the primary selling point of the 6N30P-DR is its linearity and neutrality. And I admit that for quite some time, I felt that output tubes/op amps should be as neutral as possible in order to reveal the true sonic signature of the drivers. However, in the process of rolling op amps in my LD1+, I discovered that neutral and linear often just doesn't sound very good. These very neutral chips had poor synergy with my driver tubes. The combination simply wasn't "musical." My current opamp, the MUSES02, is not all that neutral or linear, but it has a wonderful synergy with my driver tubes, and offers a very musical presentation.
  
 Similarly, the E80CC is tops in terms of linearity and neutrality. However, as a driver in my system, it too lacks "musicality". While I still consider it to be a very good tube, it doesn't get much playing time in my system. I primarily use it as a standard to evaluate new tubes. Comparing them to the E80CC helps me to determine how their frequency response deviates from neutral. But in the end, 6SN7s and ECC40s are getting the vast majority of the playing time.
  
 As your C3gs are also very linear, I suspect that combining them with the very neutral 6N30P-DRs is simply not a good match. No synergy. Whereas, the less linear, but bassy and warm Psvanes have great synergy with your C3gs. And I am looking forward to reading your observations regarding the 1940's Sylvania VT231 in your system.


----------



## gibosi

Received a pair of Raytheon 6SN7GTB made in Japan. As Mordy is very impressed with his Japan-made Ratheon 8CG7, I thought these just might have a similar sound. I do not know what year these were manufactured (U-16?), but with O-getters, they could well be early 1960's.


----------



## mordy

Hi Gibosi,
  
 Looking forward to hear how the Japanese Raytheon 6SN7GTB tubes sound. As an alternative to the Japanese Raytheon 8FQ7/8CG7 I can also recommend 8FQ7/8CG7 Sylvania tubes - seems the Japanese Raytheon tubes are hard to find; the Sylvanias should be more easily available. The main difference is that the Sylvanias have a little less bass punch; otherwise they sound similar.
  
 As mentioned before, I am waiting for to try the 6SN7 tubes as power tubes once I get the adapters needed. I agree with the posts above that some tubes have been hyped up by marketing. However, in our comparison tests the DR tubes came out on top. (That was before the 6SN7 era.)
  
 Another area that deserves more exploration is synergy. Not that I understand why, but certain tube combinations sound better. At one time I tried to speed up the listening tests by having two different tubes as drivers for the right and left channels and A/B the sound by turning the balance control all the way right or left. Even though the two channels in the LD are completely independent, it did not work. Somehow there was some kind of effect that one channel affected the other, and the only way to properly evaluate a tube was to have two of the same playing.
  
 From the little window shopping I did looking at very high end systems I did notice that some of them use the 6SN7 as drivers. Yet others use the 6SL7, but I did not have much luck with the ones I tried in my system. Wonder how the 6SL7 works as a driver with the 6SN7 as power tubes? Or all three 6SN7 tubes?


----------



## Artsi

mordy said:
			
		

> Wonder how the 6SL7 works as a driver with the 6SN7 as power tubes? Or all three 6SN7 tubes?



 


www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/3795#post_9952269
I did use happily 3 octals with my LD mk2 over 100 pages ago.


----------



## mab1376

mordy said:


> Hi Gibosi,
> 
> Looking forward to hear how the Japanese Raytheon 6SN7GTB tubes sound. As an alternative to the Japanese Raytheon 8FQ7/8CG7 I can also recommend 8FQ7/8CG7 Sylvania tubes - seems the Japanese Raytheon tubes are hard to find; the Sylvanias should be more easily available. The main difference is that the Sylvanias have a little less bass punch; otherwise they sound similar.
> 
> ...


 
  
 I'm using the 6SU7GTY as my driver (basically a 6SL7) and love it with the 6SN7GTB as the power tubes.
  
 Haven't tried them with other tube types yet.


----------



## TrollDragon

We need some pictures of the octal setups for the thread.


----------



## hypnos1

gibosi said:


> I am not entirely surprised. To my way of thinking, the primary selling point of the 6N30P-DR is its linearity and neutrality. And I admit that for quite some time, I felt that output tubes/op amps should be as neutral as possible in order to reveal the true sonic signature of the drivers. However, in the process of rolling op amps in my LD1+, I discovered that neutral and linear often just doesn't sound very good. These very neutral chips had poor synergy with my driver tubes. The combination simply wasn't "musical." My current opamp, the MUSES02, is not all that neutral or linear, but it has a wonderful synergy with my driver tubes, and offers a very musical presentation.
> 
> Similarly, the E80CC is tops in terms of linearity and neutrality. However, as a driver in my system, it too lacks "musicality". While I still consider it to be a very good tube, it doesn't get much playing time in my system. I primarily use it as a standard to evaluate new tubes. Comparing them to the E80CC helps me to determine how their frequency response deviates from neutral. But in the end, 6SN7s and ECC40s are getting the vast majority of the playing time.
> 
> As your C3gs are also very linear, I suspect that combining them with the very neutral 6N30P-DRs is simply not a good match. No synergy. Whereas, the less linear, but bassy and warm Psvanes have great synergy with your C3gs. And I am looking forward to reading your observations regarding the 1940's Sylvania VT231 in your system.


 
  
 Hi gibosi.
 Very interesting points you make - _possibly_ the reason, but not _wholly_ convinced!..viz since the Psvanes (MKII) are supposedly 'tuned' more to a 'modern' upper frequency character, logic would therefore be somewhat hard-pressed to explain why they are surpassing the DRs in EVERY respect - with now just 24hrs on them, and apparently even more improvement to come. But perhaps this 'synergy' effect (which also seems to bamboozle mordy!) defies ALL logic (which always unsettles me, lol!). Perhaps one day (if I ever find time?) I may do a pile of comparison combinations re DRs/30Pi - EH/6N6P and various drivers...but can't promise...In the meantime, what happens when the Sylvania VT231s arrive may well shed some more light on the matter...hope so.
 As an aside - but may also be related/relevant? - I have noticed that there is nowhere near the same level of 'sshhh' when the volume is turned right to max (with no music playing!), compared to the DRs. My gut feeling is still that the DRs are NOT AT ALL worth the kind of bucks demanded...but who am I?...


			
				mordy said:
			
		

> As mentioned before, I am waiting for to try the 6SN7 tubes as power tubes once I get the adapters needed. I agree with the posts above that some tubes have been hyped up by marketing. However, in our comparison tests the DR tubes came out on top. (That was before the 6SN7 era.)
> 
> Another area that deserves more exploration is synergy. Not that I understand why, but certain tube combinations sound better.


 
  Yo mordy...they may well have come out on top, but perhaps (as I mentioned previously) they were simply the 'big fish in a small pond'?!
  
 Certainly MUCH more work needs to be done re 'synergy'...are you volunteering? As you said, the only way to get any idea whatsoever is to have both channels operating in tandem - a lot of work!
  


trolldragon said:


> We need some pictures of the octal setups for the thread.


 
  
 Hi TD...mine's on P363 (mind you, LOCTALS to the fore!!).


----------



## mordy

Hi hypnos1,
  
 Once I get the adapters I'll give the synergy theory a shot - I have about a dozen each of 6SL7 and 6SN7 tubes. Re the DR Super Tubes it seems that the IR tubes are quite close so it could be marketing hype (or the biggest fish in a small pond).
  
 We have to form our own honest opinions and I would not be surprised if some inexpensive relatively unknown tubes make it to the top of the list - can't wait!


----------



## hypnos1

mordy said:


> Hi hypnos1,
> 
> Once I get the adapters I'll give the synergy theory a shot - I have about a dozen each of 6SL7 and 6SN7 tubes. Re the DR Super Tubes it seems that the IR tubes are quite close so it could be marketing hype (or the biggest fish in a small pond).
> 
> We have to form our own honest opinions and I would not be surprised if some inexpensive relatively unknown tubes make it to the top of the list - can't wait!


 
  
 Hi mordy.
  
 I look forward (as I am sure does everyone else!) to your findings...methinks you'll be doing a good few 24hr sessions - poor you!! But we will all? be rooting for you...as for me, I need my beauty sleep, alas...
  
 In a way I hope it's just a case of wishful thinking re the 'inexpensive/unknown...........'. With what I've spent on DRs and Psvanes (at least I got the VT231s for small dosh) I would be _mightily miffed_, lol!. Ah well, the things we do in the name of research/progress!....(Mind you, I doubt they would look as gorgeous - to _my_ eyes anyway - as the Psvanes! And I must admit I have never seen a better-made tube...not everything that comes out of China is poorly-made c**p.


----------



## i luvmusic 2

mikelap said:


> Well its a done deal i am the proud owner of a gorgeous Woo Audio 2 tube amp .My treat picture wise of course lol.


 
 Congratulations!


----------



## i luvmusic 2

I have not sign in for a few days and i missed a lot.


----------



## i luvmusic 2

I'am looking forward to see the tutorial  picture for 6SN7 power tubes...


----------



## kvtaco17

So my 6SN7 love has spread to my Lyr... I ordered some adapters and materials to start butchering that amp too.


----------



## gibosi

kvtaco17 said:


> So my 6SN7 love has spread to my Lyr... I ordered some adapters and materials to start butchering that amp too.


 
  
 I will be very interested in your observations. In searching the Lyr threads some time ago, I found that 6CG7s had been tried, and those few who posted felt that the Lyr was designed so tightly arround 6DJ8s, that it couldn't bias 6CG7s properly....


----------



## kvtaco17

gibosi said:


> I will be very interested in your observations. In searching the Lyr threads some time ago, I found that 6CG7s had been tried, and those few who posted felt that the Lyr was designed so tightly arround 6DJ8s, that it couldn't bias 6CG7s properly....


 
I've been following that tread since I got my Lyr and I never remember seeing that discussion... I'll go dig some more before I chase this...
  
 Found it! So it has a 200V rail... I need like 400V to be in spec and to get control of the tubes... I supposed I'll have to investigate building a new circuit to power them...


----------



## gibosi

kvtaco17 said:


> I've been following that tread since I got my Lyr and I never remember seeing that discussion... I'll go dig some more before I chase this...
> 
> Found it! So it has a 200V rail... I need like 400V to be in spec and to get control of the tubes... I supposed I'll have to investigate building a new circuit to power them...


 
  
 But I wonder about that...   I am pretty sure our LDs have 200V rails?


----------



## TrollDragon

kvtaco17 said:


> I've been following that tread since I got my Lyr and I never remember seeing that discussion... I'll go dig some more before I chase this...
> 
> Found it! So it has a 200V rail... I need like 400V to be in spec and to get control of the tubes... I supposed I'll have to investigate building a new circuit to power them...


That would require a complete new HV power supply... New transformer, caps, resistors. I'd look for an amp that takes 6SN7's as default, it would be cheaper IMHO.

The little single tube hybrid I have for review takes a 6922, some of my 6DJ8's distort in it and it is a biasing issue. I crank up the trim pots and I can get the odd 6DJ8's to play nice. If I changed the cathode resistors I could probably get the 6H9C to work without distortion like it has now.

I'd look into biasing if you have issues with the 6SN7 in the lyr, but I am just guessing. There is nothing as versatile as the Little Dot for rolling many different tubes, except for that Garage1217 plastic case stuff, which is just butt ugly in my opinion.


----------



## TrollDragon

The other thing is the little single tube hybrid runs the 6922 at 5V on the plate, so I don't think you really need 400V...


----------



## Artsi

trolldragon said:


> The other thing is the little single tube hybrid runs the 6922 at 5V on the plate, so I don't think you really need 400V...


 
 5V on the plate? 
	

	
	
		
		

		
		
	


	




 No wonder if there is easily distortion. It's a miracle that it is possible to get any sound through with voltages like that. And i have been thinking, that under 50v between plate and cathode is no good.


----------



## kvtaco17

trolldragon said:


> That would require a complete new HV power supply... New transformer, caps, resistors. I'd look for an amp that takes 6SN7's as default, it would be cheaper IMHO.
> 
> The little single tube hybrid I have for review takes a 6922, some of my 6DJ8's distort in it and it is a biasing issue. I crank up the trim pots and I can get the odd 6DJ8's to play nice. If I changed the cathode resistors I could probably get the 6H9C to work without distortion like it has now.
> 
> I'd look into biasing if you have issues with the 6SN7 in the lyr, but I am just guessing. There is nothing as versatile as the Little Dot for rolling many different tubes, except for that Garage1217 plastic case stuff, which is just butt ugly in my opinion.


 

 Don't ruin my dreams lol


----------



## hypnos1

Well folks, I'm half-way through the 100 hr burn-in of the Psvanes + adapters, and last night (at 35hrs) I had a minor unpleasant shock - the changes that can take place during burn-in certainly are VERY interesting/strange, but with these the 35hr mark was the strangest I have ever encountered. From  apparent (almost) perfection straight out of the box -  and trouncing of the 6N30P-DRs -  I was presented with something very worrying (for _me_ at least)..._too_ much of the classic "warm/soft/tubey" sound. I know many people go to tubes just for that very reason, but I myself prefer what some consider "cool/analytical/too(?) much detail". I find this generally brings a greater sense of clarity, instrument/voice separation, and 3-dimensional sound stage. And those wonderful _micro_ details and transients can be so magical (given a sound engineer who knows what they are doing!). Well, these qualities I love had almost disappeared! Bass and (instrumental) mids had come to the fore (which I am sure would have delighted many!), but at the expense of what I love - and certain vocals were pushed further away - horror of horrors! My anguish was heightened by the possible appearance of unwelcome 'extras' related to the "tuning for greater upper frequencies". But I was at least spared this nasty surprise...
  
 Needless to say I didn't sleep well last night!...I know I should have known better, but never having encountered such an about-face before I was caught off-guard...Thankfully, a further 16hrs have brought another transformation - I'm a happy chappie once more. All that I crave has returned - balance is restored, and the DRs have suffered another KO. Once again the Psvanes at the very  least match the DRs, and now especially, surpass them in _most_ areas...and the newly-tamed bass is truly delicious. To paraphrase a review on 6SN7s, the Psvanes are to the DRs what the Sylvania 6SN7GT "Bad Boys" are to their VT231s - viz the latter being heaven from the bottom up, but the Bad Boys even more so, and with uber-divine bass!
  
 So tonight I shall sleep more soundly....just hope there are no more nasty about-turns, lol!!!


----------



## TrollDragon

Here you go MIKELAP the new Black Diamond Telefunken 6922's are available for shipping.
  
http://www.telefunken-elektroakustik.com/products/tubes/black-diamond-tubes/e88cc-tk.php


----------



## d4rkch1ld

Hey guys can some1 be kind enough to direct me what kind of modification needs to be done to run these E88CC tubes. I have little dot mkIVSE. Thx


----------



## mordy

Hi,
  
 If you don't need to impress ur friends with the Telefunken logo, you could buy these 6922 tubes made in the same factory for roughly 70% less ($42 vs $12):
  
 https://tubedepot.com/products/jj-e88cc-6922-preamp-vacuum-tube?gclid=CJ7Rq6idn70CFfNxOgodqHUA6w


----------



## TrollDragon

mordy said:


> Hi,
> 
> If you don't need to impress ur friends with the Telefunken logo, you could buy these 6922 tubes made in the same factory for roughly 70% less ($42 vs $12):
> 
> https://tubedepot.com/products/jj-e88cc-6922-preamp-vacuum-tube?gclid=CJ7Rq6idn70CFfNxOgodqHUA6w


 
 So the JJ's are the same as the Black Diamonds?


----------



## TrollDragon

d4rkch1ld said:


> Hey guys can some1 be kind enough to direct me what kind of modification needs to be done to run these E88CC tubes. I have little dot mkIVSE. Thx


 
 Start with the links gibosi provides in this post here, everything you need is there.
  
http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/3435#post_9882977


----------



## MIKELAP

d4rkch1ld said:


> Hey guys can some1 be kind enough to direct me what kind of modification needs to be done to run these E88CC tubes. I have little dot mkIVSE. Thx


 
 Here is a wiring diagram for 6DJ8 tube  adapter .  it all depends what type of adapter you want to make using a breadboard which is easier  or made with copper pipes  which involves soldering


----------



## mordy

Hi TD,
  
 OK, the TF Black Diamond tubes have gold plated pins, but still made by JJ tubes.
  
 "TELEFUNKEN vacuum tubes have been the benchmark of excellence in all audio applications, both production and reproduction, for many decades. Today, this rich history continues with the introduction of new production tubes from TELEFUNKEN Elektroakustik, _*in partnership with JJ Tubes from the Carpathian Mountains of Cadca in Slovakia*_."
  
 http://www.telefunken-elektroakustik.com/products/tubes/


----------



## Oskari

mordy said:


> OK, the TF Black Diamond tubes have gold plated pins, but still made by JJ tubes.


 
  
 There are gold-pin JJs as well.
  
http://www.thetubestore.com/Tubes/6922-E88CC-Tube-Types/JJ-E88CC-6922-Gold


----------



## gibosi

I received a very nice package this afternoon: Sennheieser HD 700


----------



## i luvmusic 2

gibosi said:


> I received a very nice package this afternoon: Sennheieser HD 700


 
 Congratulations and Enjoy.


----------



## MIKELAP

gibosi said:


> I received a very nice package this afternoon: Sennheieser HD 700


 
 Wow ,nice good for you gibosi.


----------



## TrollDragon

gibosi said:


> I received a very nice package this afternoon: Sennheieser HD 700


Congratz gibosi!

All the Senn people in here, no love for beyer's?


----------



## kvtaco17

gibosi said:


> I received a very nice package this afternoon: Sennheieser HD 700


 

 congrats you are now "one of us"
  
 HD700/800 brotherhood 2014!


----------



## TrollDragon

mordy said:


> Hi TD,
> 
> OK, the TF Black Diamond tubes have gold plated pins, but still made by JJ tubes.
> 
> ...


Thanks mordy, I was mesmerized by the Black Logo and didn't read the spiel.


----------



## kvtaco17

trolldragon said:


> Congratz gibosi!
> 
> All the Senn people in here, no love for beyer's?


 
 I had DT990's... I also briefly had a T1... I like beyer's, I just got a stupid good deal on a new set of HD800's...


----------



## mab1376

trolldragon said:


> Congratz gibosi!
> 
> All the Senn people in here, no love for beyer's?


 
  
 I have the T70, I really want to swap them for a T90 though, jumped on the T70's when they came out so I didn't have the T90 option at the time.


----------



## TrollDragon

Good to hear there is a little beyer love in this thread! I really have to hear some Senn's one day to see what they are all about, the AKG's as well.


----------



## MIKELAP

trolldragon said:


> Good to hear there is a little beyer love in this thread! I really have to hear some Senn's one day to see what they are all about, the AKG's as well.


 
 Roadtrip!


----------



## MIKELAP

mikelap said:


> Wow ,nice good for you gibosi.


 
 Hey gibosi they look very comfortable are they leather pads personnally the  hd 800 are the most comfortable HP  to date i owned. and those look very similar very nice .


----------



## TrollDragon

mikelap said:


> Roadtrip!


BigTime!

Woo and HD800's can I be your long lost brother from another mother? 
One of these days for sure!

In the meantime I'd settle for the "Big Neutral Trifecta", the DT880's which I own, add an HD600 and a K701. That would cover the neutral bases perfectly.

But if I had MIKELAP's money it would be Audeze for the endgame.


----------



## kvtaco17

trolldragon said:


> Good to hear there is a little beyer love in this thread! I really have to hear some Senn's one day to see what they are all about, the AKG's as well.


 
  
  


mikelap said:


> Roadtrip!


 
  
 Being in MN really is like living in lower Canada lol... I bet a few of us could help satisfy your need to demo some AKG's and Senn's.


----------



## MIKELAP

trolldragon said:


> BigTime!
> 
> Woo and HD800's can I be your long lost brother from another mother?
> 
> ...


 
 Shure Bro anytime. As for money well i would like to believe your statement ,which reminds me gotta go buy lottery tickets lol . OK i tought i already  had my endgame HP hmm.... ! You just planted a seed right .HONEY TD IS TRYING TO INFLUENCE ME AGAIN.!


----------



## TrollDragon

kvtaco17 said:


> Being in MN really is like living in lower Canada lol... I bet a few of us could help satisfy your need to demo some AKG's and Senn's.


Thanks for the offer, very much appreciated.

New Prague is 3400 km's away from me and MIKELAP is 1200... I could probably talk the wife into a trip to Montreal... But Minneapolis might be stretching it a bit far... Now she has some quilting friends in Des Moines... Nah it would never fly.


----------



## MIKELAP

trolldragon said:


> Thanks for the offer, very much appreciated.
> 
> New Prague is 3400 km's away from me and MIKELAP is 1200... I could probably talk the wife into a trip to Montreal... But Minneapolis might be stretching it a bit far... Now she has some quilting friends in Des Moines... Nah it would never fly.


 
  
 Audio show  next week Montreal Hotel Hilton Bonanenture .


----------



## TrollDragon

mikelap said:


> HONEY TD IS TRYING TO INFLUENCE ME AGAIN.!


End of the month, the Audio Show in Montreal. Woo and Audeze will both be there and you need to hear how amazing the Woo WA2 can be paired with Ortho's.

LCD-3's, X's or XC's... The lure is strong, like a sirens sweet song!


----------



## TrollDragon

mikelap said:


> Audio show  next week Montreal Hotel Hilton Bonanenture .


Already tried that... Drop her off at the daughters in NB and then 7 hours onto Montreal, she wouldn't bite...


----------



## gibosi

mikelap said:


> Hey gibosi they look very comfortable are they leather pads personnally the  hd 800 are the most comfortable HP  to date i owned. and those look very similar very nice .


 
  
 I have had them on my head for less than an hour, but first impressions, these are crazy good.  
 The pads appear to be velour, not leather. While I never thought my HE 300 were uncomfortable, these are considerably more comfortable. The HD 700s are little smaller and lighter than the HD 800, but my impression is they have a very similar fit and feel.


----------



## kvtaco17

trolldragon said:


> Thanks for the offer, very much appreciated.
> 
> New Prague is 3400 km's away from me and MIKELAP is 1200... I could probably talk the wife into a trip to Montreal... But Minneapolis might be stretching it a bit far... Now she has some quilting friends in Des Moines... Nah it would never fly.


 
 Des Moines isn't much farther from Minneapolis lol jk


----------



## mab1376

The meet on long island is on the front page if anyone is in the NY metro area on 4/5.


----------



## mordy

Hi Gibosi,
  
 Congratulations on the HD700 headphones!
  
 Way back I had a pair of HD600 but I could not wear them for a long time - too hot and not comfortable for me. Bought a pair of Audio Technica ATH-AD700 that are very comfortable. However, the sound and resolution is better from my inexpensive Polk speakers.
  
 Any suggestions for very good sounding, comfortable headphones in a low price range?


----------



## kvtaco17

Mordy, it depends on what kinda sound your after... Do u want something laid back or aggressive? What kinda eq profile? (airy dry or lush and euphoric) and how cheap is cheap?

cans I usually recommend around $200 would include...



k/q7xx
ad900x
dt880
hd598

and they are all pretty comfy!


----------



## gibosi

kvtaco17 said:


> Mordy, it depends on what kinda sound your after... Do u want something laid back or aggressive? What kinda eq profile? (airy dry or lush and euphoric) and how cheap is cheap?
> 
> cans I usually recommend around $200 would include...
> 
> ...


 
  
 Is the DT990 Pro worth $135.00?
  
 http://www.amazon.com/gp/product/B0011UB9CQ/ref=gno_cart_title_2?ie=UTF8&psc=1&smid=A304D686EJ3MRJ


----------



## kvtaco17

They are worth it if you want a v shaped sound... They are super fun and pretty detailed... I kinda miss mine lol 

the 880 uses the same basic driver... The difference between the 2 is the housing and dome foam. I'd look at 880's because u can easily remove the foam and basically have the 990.


----------



## MIKELAP

mordy said:


> Hi Gibosi,
> 
> Congratulations on the HD700 headphones!
> 
> ...


 
 Dont know if you like beyerdynamic DT990 250 OHMS theres a pair in my neck of the woods still has 1 year left on warranty he paid $230.00 for them selling for $150.00 CAD that $135.00 about US  heres link                 http://www.canuckaudiomart.com/details/649112691-beyerdynamic_dt990/


----------



## TrollDragon

DT880's are a great inexpensive neutral choice as well.


----------



## hypnos1

gibosi said:


> I have had them on my head for less than an hour, but first impressions, these are crazy good.
> The pads appear to be velour, not leather. While I never thought my HE 300 were uncomfortable, these are considerably more comfortable. The HD 700s are little smaller and lighter than the HD 800, but my impression is they have a very similar fit and feel.


 
  
 Hi there g.
  
 So you've gone space-age, eh? They certainly are one _serious_ set of 'phones....shame they're also _serious_ money, lol! Christmas HAS come early...ENJOY!


----------



## BbOO

Not sure if this is the right place to ask but: i bought a Little Dot MK III which i am planing to connect to Fiio E10s line out by using a very generic RCA to mini cable (1-3 euros). I wanted to know how important is the quality of the RCA cable in such a setup?


----------



## gibosi

hypnos1 said:


> So you've gone space-age, eh? They certainly are one _serious_ set of 'phones....shame they're also _serious_ money, lol! Christmas HAS come early...ENJOY!


 
  
 Everything fell into place very nicely. My tax refund was larger than I expected and I found them on clearance. Even so, I am still in a state of shock at what I have done, but enjoying them immensely.


----------



## gibosi

bboo said:


> Not sure if this is the right place to ask but: i bought a Little Dot MK III which i am planing to connect to Fiio E10s line out by using a very generic RCA to mini cable (1-3 euros). I wanted to know how important is the quality of the RCA cable in such a setup?


 
  
 It depends...  Some folks think cables make a significant difference, and others don't. My recommendation is to go forward with the purchase of a generic cable for now. And later, if you would like to experiment, try something a bit better, say 10-15 euros, and see if you notice a difference.


----------



## Oskari

bboo said:


> I wanted to know how important is the quality of the RCA cable in such a setup?


 
  
 Generally speaking, not that important at all (if it's not faulty). Copper, any copper, is just copper. There are people that would disagree but it is OK to disagree with them.


----------



## mab1376

oskari said:


> Generally speaking, not that important at all (if it's not faulty). Copper, any copper, is just copper. There are people that would disagree but it is OK to disagree with them.


 
  
 Personally i'd take build quality over materials used.
  
 Yeah i bought an aftermarket cable for my HD650's, but I don't really notice any real difference. Money that could have been better spent elsewhere.
  
 Cables to go is all i use for RCA. Anyone who buys Nordost cables has entirely too much money eating away at them.
  
 http://www.cablestogo.com/product/40081
  
 This is even kinda pricy but i like the flexibility of the cable and the build quality is great.


----------



## Oskari

mab1376 said:


> Yeah i bought an aftermarket cable for my HD650's


 
  
 I bought an original HD650 cable for my HD600s when the HD600 cable had problems (at a considerable mileage).


----------



## mordy

Beyerdynamic DT-990-Pro-250 Headphones from Amazon.com for $129.95
  
 Is this a good deal? These phones come in 250/32/600 ohm. Only the 250 ohm version is on sale. Which value works best for LD MKIII?


----------



## MIKELAP

mordy said:


> Beyerdynamic DT-990-Pro-250 Headphones from Amazon.com for $129.95
> 
> Is this a good deal? These phones come in 250/32/600 ohm. Only the 250 ohm version is on sale. Which value works best for LD MKIII?


 
 Dont really know but what i know is my 300 ohms Senns sound great on mk3 from what i heard higher ohms with Littledot is a better match


----------



## kvtaco17

mordy said:


> Beyerdynamic DT-990-Pro-250 Headphones from Amazon.com for $129.95
> 
> Is this a good deal? These phones come in 250/32/600 ohm. Only the 250 ohm version is on sale. Which value works best for LD MKIII?


 
 Shouldn't make much of a difference... Last year I head both the 250 omh (my old cans) and a 600 ohm version and heard no real difference.
  
 The mkiii outputs 350 mW @ 300/600 ohm so go for cheap!


----------



## TrollDragon

B&H has them for $129 as well.
 http://www.bhphotovideo.com/c/product/92807-REG/Beyerdynamic_459038_DT_990_PRO_Studio.html
  
 Did you find the DT990`s a bit sharp in the treble kvtaco17? That is the biggest issue brought up in the beyer thread, some find the treble just a little too piercing.


----------



## kvtaco17

trolldragon said:


> B&H has them for $129 as well.
> http://www.bhphotovideo.com/c/product/92807-REG/Beyerdynamic_459038_DT_990_PRO_Studio.html
> 
> Did you find the DT990`s a bit sharp in the treble kvtaco17? That is the biggest issue brought up in the beyer thread, some find the treble just a little too piercing.


 
 on a few recordings it can be, however that was on my modi and magni, on my LD it was fine


----------



## TrollDragon

kvtaco17 said:


> on a few recordings it can be, however that was on my modi and magni, on my LD it was fine


 
  
 Thanks.
 I had read that the M&M stack was a bit bright, the LD would tame that that for sure.


----------



## spiderking31

mordy said:


> Beyerdynamic DT-990-Pro-250 Headphones from Amazon.com for $129.95
> 
> Is this a good deal? These phones come in 250/32/600 ohm. Only the 250 ohm version is on sale. Which value works best for LD MKIII?


 600 ohm is probably the best, but you'll have no issues running the 250 ohm headphones


----------



## TrollDragon

spiderking31 said:


> 600 ohm is probably the best, but you'll have no issues running the 250 ohm headphones


 
 This has been hashed over and beat to death in the beyer thread at least once a month... There is NO difference between the 250Ω & 600Ω versions, also the Pro's clamp a little tighter so they present a little more bass presence over the Premium's.


----------



## hypnos1

bboo said:


> Not sure if this is the right place to ask but: i bought a Little Dot MK III which i am planing to connect to Fiio E10s line out by using a very generic RCA to mini cable (1-3 euros). I wanted to know how important is the quality of the RCA cable in such a setup?


 
  
 Yeah, this is a _very_ controversial subject...but my way of thinking is why cut corners if the rest of your equipment is decent?. I personally have found definite improvements when upgrading cables - audio and video interconnects/speaker cable/headphone cable (the greatest when I made my own pure silver jobs - commercial ones would NOT be worth the money demanded). But , of course, so much depends on what is happening in the rest of the signal path, even down to the power supply! Not to mention ears, preferences etc. etc...Plus depth of pocket. But something like the cables mab1376 mentions I am sure would do you proud :
  


mab1376 said:


> Personally i'd take build quality over materials used.
> 
> Yeah i bought an aftermarket cable for my HD650's, but I don't really notice any real difference. Money that could have been better spent elsewhere.
> 
> ...


 
  
 These look pretty good to me, for not _too_ much money...


----------



## hypnos1

Getting close to the 100hr mark with the Psvanes and, thankfully, no more scary about-turns...on the contrary, they are performing better than I could have ever hoped for...PHEW!! What the sound would be with gibosi's HD700s or mikelap's 800s I just cannot imagine...lottery here I come!..


----------



## mab1376

hypnos1 said:


> Yeah, this is a _very_ controversial subject...but my way of thinking is why cut corners if the rest of your equipment is decent?. I personally have found definite improvements when upgrading cables - audio and video interconnects/speaker cable/headphone cable (the greatest when I made my own pure silver jobs - commercial ones would NOT be worth the money demanded). But , of course, so much depends on what is happening in the rest of the signal path, even down to the power supply! Not to mention ears, preferences etc. etc...Plus depth of pocket. But something like the cables mab1376 mentions I am sure would do you proud :
> 
> 
> These look pretty good to me, for not _too_ much money...


 
  
 And much cheaper on amazon which i where i buy them:
  
 http://www.amazon.com/C2G-Cables-Go-45428-Sonicwave/dp/B0009JR3RA/ref=sr_1_3?ie=UTF8&qid=1395423730&sr=8-3&keywords=cables+to+go+sonicwave+rca


----------



## spiderking31

trolldragon said:


> This has been hashed over and beat to death in the beyer thread at least once a month... There is NO difference between the 250Ω & 600Ω versions, also the Pro's clamp a little tighter so they present a little more bass presence over the Premium's.


 if there's no difference, why would they make a 250 ohm, and also a 600 ohm? :rolleyes:


----------



## spiderking31

mab1376 said:


> And much cheaper on amazon which i where i buy them:
> 
> http://www.amazon.com/C2G-Cables-Go-45428-Sonicwave/dp/B0009JR3RA/ref=sr_1_3?ie=UTF8&qid=1395423730&sr=8-3&keywords=cables+to+go+sonicwave+rca


I use my after market cable with my hd650's and I use a monster prolinks rca cable with my little dot mk3, and I notice little differences....so I think it's worth it....


----------



## mab1376

spiderking31 said:


> if there's no difference, why would they make a 250 ohm, and also a 600 ohm?


 
  
 The 600 would get more power out of an OTL amp I believe.


----------



## spiderking31

mab1376 said:


> The 600 would get more power out of an OTL amp I believe.


 that makes sense


----------



## i luvmusic 2

IMO for  250 ohms it sounded like it need more power with my LD MK III but when it's plug-in to my LD 1+ it's better, now i have DT880 Prem.600 Ohms with MK III it sound smooth and powerful and on LD1+ it sound congested.so i think the diference between the two is for how would you want to use them and not for the sound.


----------



## spiderking31

Little dot mk3 is pretty powerful in my opinion....I'm running sennheiser hd650's on them, no issues, and are getting maximum power. Have also used hifiman he-400's on it, and had no problems. Both sounded awesome!


----------



## kvtaco17

i luvmusic 2 said:


> IMO for  250 ohms it sounded like it need more power with my LD MK III but when it's plug-in to my LD 1+ it's better, now i have DT880 Prem.600 Ohms with MK III it sound smooth and powerful and on LD1+ it sound congested.so i think the diference between the two is for how would you want to use them and not for the sound.


 
 MKIII makes more the 2x power then the LD1+ @300 ohm...350mv vs 150mv... I'd assume your LD1+ is in high gain mode and the MKIII is in low?


----------



## i luvmusic 2

When i was doing my own testing to know which HP i will keep both amps are in the same gain settings i did high and low gain only no inbetween gain settings.


----------



## kvtaco17

i luvmusic 2 said:


> When i was doing my own testing to know which HP i will keep both amps are in the same gain settings i did high and low gain only no inbetween gain settings.


 
 Odd, but oh well... I don't own the MKIII so I cant really comment based on experience, just numbers.


----------



## TrollDragon

You really can't compare OTL to hybrid anyway... 

The DT880 have a different sound when driven from the E09K as opposed to my MK IV.


----------



## gibosi

6SN7 update...
  
 For some time now, my favorite 6SN7 has been the small-bottle Sylvania 6SN7W. Switching from the HE 300 to the HD 700, this tube continues to impress. 
  
 (In case it is of interest in light of the current discussion on OTL LDs versus the LD 1+ hybrid, the HE 300 is 50 Ohms, 93 dB, and the HD 700 is 150 Ohms, 105 dB, and I notice that I have the volume set almost identically for both on my LD 1+.)


----------



## kvtaco17

gibosi said:


> 6SN7 update...
> 
> For some time now, my favorite 6SN7 has been the small-bottle Sylvania 6SN7W. Switching from the HE 300 to the HD 700, this tube continues to impress.
> 
> (In case it is of interest in light of the current discussion on OTL LDs versus the LD 1+ hybrid, the HE 300 is 50 Ohms, 93 dB, and the HD 700 is 150 Ohms, 105 dB, and I notice that I have the volume set almost identically for both on my LD 1+.)


 
 I have both the shorty like you love and a black bottom, tall bottle (well taller then the short) GTB and I have to agree they are both beautiful... the GTB has slightly better mids at the expense of some air... I love both for different reasons...
  
 Currently I'm running the Gold Arrow 6SN7 (yeah I know I';m home early lol) and its very similar to the short bottle Sylvania... time will tell...


----------



## gibosi

kvtaco17 said:


> I have both the shorty like you love and a black bottom, tall bottle (well taller then the short) GTB and I have to agree they are both beautiful... the GTB has slightly better mids at the expense of some air... I love both for different reasons...
> 
> Currently I'm running the Gold Arrow 6SN7 (yeah I know I';m home early lol) and its very similar to the short bottle Sylvania... time will tell...


 
  
 As the number of variants produced by Sylvania is large enough to be quite confusing, I should clarify that the tube I am loving is a short-bottle 1944 JAN-CHS-6SN7W. This tube has a single support rod between the two micas and 4 umbrella-like spokes extending downward from the top mica. The short-bottle 6SN7GT and 6SN7GTA, produced in the early 1950's, is a different tube, still excellent, but with slightly dryer mids.


----------



## i luvmusic 2

trolldragon said:


> You really can't compare OTL to hybrid anyway...
> 
> The DT880 have a different sound when driven from the E09K as opposed to my MK IV.


 
 Exactly even at 250 ohms i still prefer it with my hybrid than otl and at 600 ohms otl for me.


----------



## i luvmusic 2

Is this tube (6AS7,6080 and 6082)compatible with the 6SN7 adapter with external PS for LD?Thanks!


----------



## gibosi

i luvmusic 2 said:


> Is this tube (6AS7,6080 and 6082)compatible with the 6SN7 adapter with external PS for LD?Thanks!


 
  
 Yes, the 6AS7 has the same pin-out as the 6SN7 and could be used in the LD with an external PS. However, this tube draws 2.5 amps of heater current, a bit more than 3 times that of a 6SN7, so a pretty heavy-duty AC adapter is necessary. For example, 15VDC and more than 1.05 amps, or 24VDC and more than .66 amps. And if you want to run two of them as output tubes, you will need to double the current. So yes it will work, but I am guessing the AC adapters many of us are currently using do not provide enough current....
  
 Edit: If you search eBay for "laptop power supply" you can find power supplies that can provide enough current.


----------



## i luvmusic 2

gibosi said:


> Yes, the 6AS7 has the same pin-out as the 6SN7 and could be used in the LD with an external PS. However, this tube draws 2.5 amps of heater current, a bit more than 3 times that of a 6SN7, so a pretty heavy-duty AC adapter is necessary. For example, 15VDC and more than 1.05 amps, or 24VDC and more than .66 amps. And if you want to run two of them as output tubes, you will need to double the current. So yes it will work, but I am guessing the AC adapters many of us are currently using do not provide enough current....
> 
> Edit: If you search eBay for "laptop power supply" you can find power supplies that can provide enough current.


 
 What about using a computer power supply?I have a broken desktop i open it and the PS is 400W 12V 15A.THANK YOU!
 Need to use High current regulator.


----------



## gibosi

i luvmusic 2 said:


> What about using a computer power supply?I have a broken desktop i open it and the PS is 400W 12V 15A.THANK YOU!


 
  
 Yes, a computer power supply has more than enough of current. However, there is still the voltage regulator to consider. My voltage regulator is rated at 2 amps continuous. If yours is similar, it would have to be replaced. This one would likely work:
  
 http://www.ebay.com/itm/331064390176?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649


----------



## i luvmusic 2

gibosi said:


> Yes, a computer power supply has more than enough of current. However, there is still the voltage regulator to consider. My voltage regulator is rated at 2 amps continuous. If yours is similar, it would have to be replaced. This one would likely work:
> 
> http://www.ebay.com/itm/331064390176?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649


 
 Yes i have that regulator received it 2 days ago and i installed it inside this salvaged electronics box and a scrap piece of aluminum build it last night not done yet but i may need to scrap this and used the Desktop PS instead.THANKS AGAIN Gibosi!


----------



## gibosi

i luvmusic 2 said:


>


 
  
 This looks very professional! I think you might have a future building and selling power supplies to Little Dot owners!


----------



## i luvmusic 2

gibosi said:


> This looks very professional! I think you might have a future building and selling power supplies to Little Dot owners!


 
 THANKS!
    The Desktop PS is Noisy i don't like it the fan is annoying some of my tubes Picked up the noise.


----------



## mordy

Hi,
  
 I just replaced my 2A voltage regulator with the one in the link above which is rated at 5A when applying a little self stick heat sink. The voltage is only displayed by one decimal so I am using a multimeter to set it. Just like the first regulator, turning the adjusting screw for the voltage changes the voltage within the decimal reading, i.e. 8.3V can mean 8.31V or 8.39V. On this voltage regulator you can adjust the readout to make it correspond to a reading from a tester - haven't tried it yet.
  
 As mentioned before, the actual voltage at the tube pins on the breadboard can be a little lower than at the voltage regulator output. In my case I am using a 8FQ7 tube as a driver. The voltage regulator LED readout fluctuates between 8.3V and 8.4V (the LED can be shut off if the flickering or light bothers you), The voltage reading is 8.44V at the regulator output terminals, and the breadboard voltage at the tube pins is 8.40V. I don't think that these small variations really matter, but it gives me satisfaction to set it precisely LOL.
  
  
 Does anybody have experience with a 6AS7 tube as a driver? Can the 6080 and the 6N13S tubes be substituted for the 6AS7 and do they have the same pinout as the 6SN7?


----------



## MIKELAP

mordy said:


> Hi,
> 
> I just replaced my 2A voltage regulator with the one in the link above which is rated at 5A when applying a little self stick heat sink. The voltage is only displayed by one decimal so I am using a multimeter to set it. Just like the first regulator, turning the adjusting screw for the voltage changes the voltage within the decimal reading, i.e. 8.3V can mean 8.31V or 8.39V. On this voltage regulator you can adjust the readout to make it correspond to a reading from a tester - haven't tried it yet.
> 
> ...


 
 What i can say is that in my WA2 i can run as power tubes 6AS7 and 6080's. in post #5540 gibosi says its same pinout


----------



## gibosi

mordy said:


> Does anybody have experience with a 6AS7 tube as a driver? Can the 6080 and the 6N13S tubes be substituted for the 6AS7 and do they have the same pinout as the 6SN7?


 
  
 With 2.5 amp heaters, I don't think this tube is typically used as a driver. But yes, it has the same pinout as a 6SN7, and I seem to remember that you are using a laptop power supply, so you have adequate power, and with your new regulator, you are good go.
  
 Edit: The 5998, 6080, 6N13S, 6N13P, 6N22P, 6N5P all appear to be similar....


----------



## Artsi

mordy said:


> Hi,
> 
> Does anybody have experience with a 6AS7 tube as a driver? Can the 6080 and the 6N13S tubes be substituted for the 6AS7 and do they have the same pinout as the 6SN7?


 
 I can use even 6AS7 tubes as driver with my little DIY amp.

 With RCA 6AS7G sound is excellent, BUT gain is very low, due to amp factor 2. So with low sensitivity headphones there could be problems to get enough power.
  
 I suggest to use 6BL7 with amp factor 15 or 6BX7 amp factor 10. These have same pinout with 6SN7, but 1.5A heater currents. These rare tubes are easily found from USA or Canada EBAY.


----------



## gibosi

artsi said:


> I suggest to use 6BL7 with amp factor 15 or 6BX7 amp factor 10. These have same pinout with 6SN7, but 1.5A heater currents. These rare tubes are easily found from USA or Canada EBAY.


 
  
 And I believe the LD can handle 1.5A heaters without having to use an external supply, so these may well be worth looking into as power tubes.


----------



## Artsi

gibosi said:


> And I believe the LD can handle 1.5A heaters without having to use an external supply, so these may well be worth looking into as power tubes.


 
 If i remember correctly LD can push 2.5A for powertubes, and 1.5A x 2 = 3A. Not recommended without external supply.


----------



## gibosi

Thanks for correcting me.


----------



## i luvmusic 2

Anyone tried gutted LD MK III/IV?My idea is to save some space on my Desk so i want to put my LD 1,MK III and the External Power Supply in one inclosure(maybe salvage some old Electronics case.or make one out of aluminum and wood)Some picture would be helpful to me.THANKS!


----------



## i luvmusic 2

Spring cleaning my wife said...


----------



## mordy

"Brainless Tales:"


----------



## MIKELAP

Over here this is still in demand  ruff winter this year .


----------



## hypnos1

artsi said:


> If i remember correctly LD can push 2.5A for powertubes, and 1.5A x 2 = 3A. Not recommended without external supply.


 
  
 Ah so - some while back when I put out feelers for possible use of 6AS7s and 6080s as powers I assumed there were other factors going against their use in our LDs...eg. plate dissipation 13W (6080). Was I worrying unduly, and do we just need to provide an external heater supply of 2x 2.5A (6080) to be safe? If so , these 6080s sure do look interesting...
  
 HOWEVER, despite fear of boring people to death re my Psvane CV181-T MKIIs, another 24 hours or so (on the already 100) have brought even  _more_ magic to the table - they obviously _love_ my C3GSs (and vice-versa). The sound I am getting reminds me of what the Senn HD700 produced over my 650s, so their combined cost is still way below the 700s!. Perhaps my wallet can now rest easy (not to mention my nervous system...). And perhaps I shan't need to explore the 6080s? Mmmm...Actually, I still have the Sylvania 6SN7GT - VT231s to trial - when they arrive from the States (my Psvanes came quicker from Hong Kong!!).


----------



## mordy

Hi Artsi and Gibosi,
  
 A 6BX7 tube is on the way which uses a 1.5A heater - should not be a problem for my 5A voltage regulator and power supply.
  
 Re the 6AS7, 6080 and similar tubes with a low amp factor of 2, what would be the result using such a tube as a driver in the LD MKIII together with my 110W ss Sony amp driving speakers?
  
 As it is now, the LD volume control is always set at near clipping (around 3o'clock), and the Sony volume is on low. (As a comparison, when using headphones I cannot use a higher setting on the LD than 9 o'clock without risking my hearing.)  The Sony amp has a LED bar graph that indicates less than 1-2W (!) to get more than adequate listening levels. If I play really loud and go higher than say 30W on this meter I experience audible hum (that may be masked by the music).
  
 Using the 6AS7 etc tubes, would I need to increase the volume level substantially? The tube I am using now, the 8FQ7, has an amplification factor of 20.
  
 .


----------



## mordy

Man, there is always something new...
  
 Here is a 6080 replacement, the mighty 6336 tube. With a heater drawing 4.75A I assume that you can use it as a space heater (Good for the Montreal winter?)
  
 http://www.radiomuseum.org/tubes/tube_6336.html


----------



## Nic Rhodes

I haven't used 6BL7GT / 6BX7GT in this circuit but have elsewhere and it is a cracking tube, in fact it is one (perhaps the only one left) of what I call the 'premium audio' tubes that is both relatively un-discovered by 'mainstream' audio, but great examples are easily bought at great prces still. Just as the Woo 6 used the 6FD7, 6EW7, 6DR7 etc which are now drying up, then the next mainstream roller amp might consider the 6BL7GT / 6BX7GTs. Some cracking 6BL7GT / 6BX7GTs tubes but I prefer the earlier full base ones rather than the button / coin based ones.


----------



## gibosi

mordy said:


> Re the 6AS7, 6080 and similar tubes with a low amp factor of 2, what would be the result using such a tube as a driver in the LD MKIII together with my 110W ss Sony amp driving speakers?
> 
> As it is now, the LD volume control is always set at near clipping (around 3o'clock), and the Sony volume is on low. (As a comparison, when using headphones I cannot use a higher setting on the LD than 9 o'clock without risking my hearing.)  The Sony amp has a LED bar graph that indicates less than 1-2W (!) to get more than adequate listening levels. If I play really loud and go higher than say 30W on this meter I experience audible hum (that may be masked by the music).
> 
> Using the 6AS7 etc tubes, would I need to increase the volume level substantially? The tube I am using now, the 8FQ7, has an amplification factor of 20.


 
  
 Since you have a very unique system, I doubt that anyone here knows for sure...  As Artsi's experience confirms, the lower gain of the 6AS7 will result in lower volume levels, but the only way to know if it is too low for your system is to try one. The 6BX7 you have on the way will give you more information. If it works well, then it might be worth trying a 6AS7. And if the output of the 6BX7 is too low, then of course, a 6AS7 would be even lower....


----------



## BassInMyFace

I am about to purchase some matched Mullard M8100 / CV4010 tubes and have the choice between two different years:
  
 1981 (Week 27) or 1983 (Week 35 or 44)
  
 Does anyone know if there is any sound quality or build differences between the two years, or if there are any differences between them at all even?  I've searched and searched without an answer unfortunately.


----------



## MIKELAP

mordy said:


> Man, there is always something new...
> 
> Here is a 6080 replacement, the mighty 6336 tube. With a heater drawing 4.75A I assume that you can use it as a space heater (Good for the Montreal winter?)
> 
> http://www.radiomuseum.org/tubes/tube_6336.html


 
 Removes the humidity thats for shure !


----------



## gibosi

bassinmyface said:


> I am about to purchase some matched Mullard M8100 / CV4010 tubes and have the choice between two different years:
> 
> 1981 (Week 27) or 1983 (Week 35 or 44)
> 
> Does anyone know if there is any sound quality or build differences between the two years, or if there are any differences between them at all even?  I've searched and searched without an answer unfortunately.


 
  
 Generally speaking, older is better. However, as these are only 2 years apart, I doubt there is any significant difference. So buying the cheapest pair might make the most sense.


----------



## BassInMyFace

gibosi said:


> Generally speaking, older is better. However, as these are only 2 years apart, I doubt there is any significant difference. So buying the cheapest pair might make the most sense.


 
  
 Thank you for the quick response!
  
 I guess I have to debate now on getting the 1981 version or waiting for something older to pop-up on eBay...


----------



## Artsi

hypnos1 said:


> Ah so - some while back when I put out feelers for possible use of 6AS7s and 6080s as powers I assumed there were other factors going against their use in our LDs...eg. plate dissipation 13W (6080). Was I worrying unduly, and do we just need to provide an external heater supply of 2x 2.5A (6080) to be safe? If so , these 6080s sure do look interesting...


 
  
 Now this is another real problem to use 6AS7's as powertube with LD. With 150ohm cathode resistors 6AS7 could hog 4-5 times the current what 6N6P uses! I think LD does not have enough anode current. And LD resistors can't stand the heat. Cathode resistors should be 10W.
  


mordy said:


> Hi Artsi and Gibosi,
> 
> A 6BX7 tube is on the way which uses a 1.5A heater - should not be a problem for my 5A voltage regulator and power supply.
> 
> ...


 
 When coming to gain 6BX7 and 6AS7, 6BX7 should work ok and 6AS7 could be 5x quieter. 5998 is better option with amp factor of 5.5.


----------



## gibosi

With my hybrid LD, rolling power tubes is not even an option, and so recently, I have been trying to figure out what amp I should buy next. Given my considerable investment in 6SN7 and ECC40 tubes, both in time and in dollars, I would prefer to be able to use them in my next amp. Moreover, I would also like to be able to roll 6AS7-type power tubes. At this time, the Bottlehead Crack looks very attractive to me. It is quite affordable and, further, it is directed to the DIY crowd. I have heard reports that 6SN7s are quite noisy in the Crack, but similar to the LD, it appears to be possible to use an external DC power supply.
  
 Having just purchased new headphones, I won't be purchasing another amp anytime soon, but thought I would throw this out to see what others think.
  
 Cheers


----------



## MIKELAP

*Friendly words of advise if your considering getting new gear :*


----------



## mordy

I an octal 6N7 tube compatible with the LD MKIII? This tube is all metal - any info about the sonic characteristics?


----------



## gibosi

mordy said:


> I an octal 6N7 tube compatible with the LD MKIII? This tube is all metal - any info about the sonic characteristics?


 
  
 This double triode has a common cathode. That is, two anodes, two grids and only one cathode. And so the 6N7 is not pin compatible with a 6SN7, and thus is not a good candidate for tube rolling in our LDs


----------



## mordy

Thanks - you saved me from a wrong purchase


----------



## hypnos1

artsi said:


> Now this is another real problem to use 6AS7's as powertube with LD. With 150ohm cathode resistors 6AS7 could hog 4-5 times the current what 6N6P uses! I think LD does not have enough anode current. And LD resistors can't stand the heat. Cathode resistors should be 10W.


 
  
 Many thanks Artsi...your greater knowledge has reinforced my gut feeling that all may not be well moving in this direction. And reinforced my belief that my current combo of C3GS and Psvane (on MKIV SE) has reached a level that would be _very_ hard indeed to surpass. I am one REALLY happy LD owner, and do not even feel the need to move to another camp (or spend a vast amount of money on new headphones)...I have so many people to thank for this fascinating, rewarding and enjoyable journey...
  
 Cheers everyone...


----------



## gibosi

Re: Mordy's recent question about inexpensive headphones
  
 I have never heart these, but this might be a good deal:
  
 Sennheiser 558's for 50% off -  $89.97 + free shipping
  
 http://slickdeals.net/f/6808062-sennheiser-hd-558-headphones-50-off-89-97-plus-free-shipping


----------



## mordy

Hi Gibosi,
  
 Thanks for the suggestion. As a rule, I always go to Amazon.com to check prices and customer reviews. IMHO you can really on them if there are many customer reviews. In this case there are almost 240 reviews, the overwhelming majority very positive.
  
 As part of my research I always start reading the negative reviews. In this case they are almost nil which is a very good sign. There seems to be a long term quality issue with the plastic headband cracking after time, but it may have been fixed - there is a two year warranty.
  
 Some reviewers describe the sound as dark. Personally, I prefer an open, airy and lively sound. Don't know how much an improvement these would be over my Audio Technica ATH AD700 ($65 B stock) headphones. Saw a pair of HD700 used going for  $544....
  
 http://www.amazon.com/Sennheiser-504631-HD-558-Headphones/product-reviews/B004FEEY9A/ref=sr_1_1_cm_cr_acr_txt?ie=UTF8&showViewpoints=1


----------



## MIKELAP

mordy said:


> Hi Gibosi,
> 
> Thanks for the suggestion. As a rule, I always go to Amazon.com to check prices and customer reviews. IMHO you can really on them if there are many customer reviews. In this case there are almost 240 reviews, the overwhelming majority very positive.
> 
> ...


----------



## mordy

Hi,
  
 Today I received the little 9 pin socket savers to be used as socket extenders. They came with a speedboat from China - only 9 days (I'm glad that I took my own advice and did not order from Hong Kong which took 30 days. The US Post Office has a small packet deal with China where the vendor in China can use a tracking number that can be tracked through USPS.)
  
 These socket savers fit inside the decorative rings around the sockets on my LD MKIII, enabling me to use 6SN7 tubes as power tubes with an octal to 6CG7 adapter (thanks mab1376). I picked a pair of 60's RCA 6SN7 tubes that are among my best driver tubes, now to be used as power tubes.
  
 By coincidence, the GE 6BX7GT tube arrived today as well. This tube draws 1.5A, but I upgraded my voltage regulator to a 5A model, so this should not be a problem (the old one was rated for 2-3A).
  


 I am pleased to report that this tube has no problem with volume, although the amplification factor is 10 and half of what I was using. Maybe I have to turn up my ss amp one notch, but no problem at all.
  
 Before I used the the BX tube I had used a 6SN7 tube as driver. The voltage regulator has an easy way to calibrate it to make the LED readout correspond to the measurements of a multimeter. I had it set to 6.3V at the tube pins.
  

  
 On the bottom of the regulator on each side of the red LED display are two little push buttons. You push in the right button and hold it for two seconds and let go. The display flashes, and you can increase or decrease the readout numbers by pushing the right or left button.
  
 A curiosity: The voltage at the BX tube pins dropped half a volt when I inserted the BX tube. In order to get it up to 6.3V I had to adjust the regulator to 6.77V (It shows 6.7V).
  
 Thanks Nic Rhodes for your comments on the 6BL7 and 6BX7 tubes. First impression is that this really is a cracking tube! In American English we would say awesome!
  
 I think we'll call it a cracking tube to keep it a secret so I can buy great sounding octals for less than $4...LOL
  
 Anyhow, the clarity, soundstage and sweet midrange are astounding. The bass is very powerful. There is a little brightness in the presentation, but I don't know if the tube is new or if I have to pair it with different power tubes. Toe tapping index is 5+
  
 The BX runs hot, too hot to touch, the power tubes are moderately hot, but the amp itself is cool as a cucumber.
  
 The sound is mesmerizing....
  
 Anyhow, this is a first impression, so tentative...
  
 Happy tube rolling!


----------



## mab1376

mordy said:


> Hi,
> 
> Today I received the little 9 pin socket savers to be used as socket extenders. They came with a speedboat from China - only 9 days (I'm glad that I took my own advice and did not order from Hong Kong which took 30 days. The US Post Office has a small packet deal with China where the vendor in China can use a tracking number that can be tracked through USPS.)
> 
> ...


 
  
  
 Glad you're up and running! I'm waiting on a pair of c3gs and some adapters I commissioned from an ebay member who makes custom adapters.
  
 Hopefully my 6SN7GTB synergizes as well as Hypnos1's cv181-z with the c3gs'.


----------



## DogMeat

Mordy;
 your rig there is very fascinating.
 please excuse that I don't know exactly what all you have hooked up there, or that I may have missed the place you identified what all you have wired into what...
  
 any chance you could post up a simple diagramme, or maybe just re-post the pic with some labels superimposed?
  
 I'm big on tube rolling adventures but I don't know the nitty-gritty electronics side of it as much as I'd like.
 What you are doing is very interesting.
  
  
 So...I know I am asking a much repeated question; can one run a 6CY7 in a LD 1?
  
 thanks so much!


----------



## mordy

Hi DogMeat,
  
 Basically I have a breadboard with a 9 pin socket with two 7 pin Vector adapters connected that allows me to use 12AX7 or 6DJ7 tube families (with different wiring) or octal tubes with an adapter in my LD MKIII. For tubes used as drivers that draw more than 0.5A an external power supply and voltage regulator is required.
  
 The latest post shows how you can use 6SN7 tubes as power tubes with the appropriate adapters.
  
 The 6CY7 tube draws 0.75A which means that you need an external power supply if it is used a driver. For the suitability for the LD MkI which I do not have experience with, I refer you to Gibosi who has been extremely helpful with all these types of questions.
  
 Once it has been determined which tube family the pinout of this tube corresponds to, and if it is suitable, you can build an adapter. There are many posts on this thread with wiring diagrams and how to instructions.
  
 Good luck!


----------



## DogMeat




----------



## mordy

Hi mab1376,
  
 Seems hard to find C3g tubes but here I came across an adapter:
  
 http://www.ebay.com/itm/1x-C3G-to-6AK5-8Pin-to-7Pin-Vacuum-Tube-socket-Convert-Socket-Adapter-/301131714830?pt=Vintage_Electronics_R2&hash=item461cd9510e
  
 Price seems steep - $35 for one.
  
 Meanwhile I am listening to the combination of RCA 6SN7GT power tubes and a GE 6BX7GT as driver. Really very nice. GT means Grand Touring if my amp was a car. Now GT just means Glass Tube. 
  
 I'm afraid that my beloved 6N6P-IR tubes will be relegated to the the dust bin......At least they have good company; some 300+ sibling tubes.
  
 Here is some (blah blah) listening impressions:
  
_Super wide, airy and open, extremely spacious 3D holographic sound stage, super detail everywhere without being etched but very musical instead, very powerful, fat and detailed bass that goes really low, pinpoint imaging and instrument separation, sweet midrange etc._
  
_On the con side: A little bright but not sibilant, could be quicker with more slam._ It is also interesting to note that this tube combination needs to warm up some 20 minutes to sound its best.
  
 Nah, strike the blah - this is real, this is cracking!
  
*British Slang: Cracking* - If something is cracking, it means it is the *best*. Usually said without pronouncing the last "G".  Thanks, Nic.


----------



## gibosi

dogmeat said:


> So...I know I am asking a much repeated question; can one run a 6CY7 in a LD 1?


 
  
 First, you should know that while the 6CY7 is a double triode, the triodes are deliberately dissimilar. One triode was intended to operate as a vertical-deflection oscillator and the other, an amplifier, combined in one tube, for use in television receivers. Not a good candidate for use in our LDs, IMO....


----------



## DogMeat

Thanks HUGELY!
 That's why one asks questions before blowing up one's gear.
	

	
	
		
		

		
			




 I always appreciate how I will receive nice, pertinent answers to questions here on HeadFi.


----------



## mordy

Hi G and DM,
  
 Thanks Gibosi for clarifying this!


----------



## gibosi

A heads-up for those of you buying 6SN7s...
  
 To the best of my knowledge, Mullard never made a 6SN7GT. Therefore, if you see a Mullard 6SN7GT, it was manufactured elsewhere, and simply relabeled. Furthermore, these tubes are typically of Russian origin.
  
 Note this listing:
  
 http://www.ebay.com/itm/Mullard-6SN7GT-Made-In-England-Grey-Plates-Tube-B-K-Tested-/191114223492?pt=Vintage_Electronics_R2&hash=item2c7f4b9f84
  
 And take a good look at the getter....  That "flying saucer" getter is a dead giveaway that these are of Russian origin and definitely were not manufactured by Mullard or any other Philips subsidiary. And if this tube really was manufactured in England, the equipment used in its manufacture was of Russian origin.


----------



## DogMeat

I simply LOVE finding the Gurus of HeadFi.org.
  
 You guys are AWESOME in your knowledge of the details that make superior gear...SUPERIOR.
  
 I don't know how many tube I.D. charts I've had to run through to be sure about my purchases being the genuine item.
BEWARE of inadequate photo-representation of what you are purchasing!
I often ask for close-ups of specific parts of an item just so that I know....
if they won't comply, I am immediately suspicious.
  
Thanks so MUCH for making HeadFi a super place!


----------



## hypnos1

mordy said:


> Hi mab1376,
> 
> Seems hard to find C3g tubes but here I came across an adapter:
> 
> ...


 
  
 Mordy....aren't you the lucky one - just 6N6P-IRs to relegate..._me_, it's 30P-DRs...OUCH!!!
  
 These 6SN7s (and _types_) really are proving to be extremely versatile tubes (for us, anyway!) - glad you have also been "converted"...
  
 Re your 'cons', perhaps (no, _probably)_ those adapters - and possibly tubes? - need a good bit more run-in yet...keep us posted!
  
 If your $4 tubes can perform the same as my C3GSs, you and I may well fall out!! But 'good on yer,mate!' (Glad I made my own adapters, at least!!).


----------



## mordy

In my 6AK5 days I ordered eight Mullard M8100 tubes from a seller in the UK. One of the tubes was labeled Mullard M8100 but was a re-branded Sylvania 6AK5W tube!
  
 Anyhow, I seem to remember somebody looking for the Mullard M8100/CV4010 tubes and I just realized that I have several of them.  If interested please PM me.


----------



## mab1376

mordy said:


> Hi mab1376,
> 
> Seems hard to find C3g tubes but here I came across an adapter:
> 
> ...


 
  
 Those are the adapters i commissioned, they just put it up for other people to purchase. they will be using hypnos1's pinout he posted a while back.
  
 They are pricy indeed, but they are the first built and handmade with skills i don't posses so i feel its worth it if the c3gs is as good as hypnos1 says. Plus i can finally get rid of the spider web of wires on my unit right now.


----------



## mordy

Hi Hypnos1,
  
 I am sure the C3g tubes are better. Thing is, I am happy with the 6BX7 tube. I am going to try some similar variants if I can get a good price.
  
 As you suggested I am burning in the tube. Don't know how much an effect the extender/socket saver adapters have on sound, but they look cheaply made and are only supposed to last 200 times for changing the tubes . They are not deep enough to completely insert the octal adapter 9 pin bottom pins, and there is is a 2 mm gap between the adapters. Maybe good for ventilation LOL?
  
 Anyhow, the price was right for the extenders - $6.59 for four incl shipping.
  
 Looking for a 6336 tube that draws 4.75A with an amplification factor of 2.7.  Wow, just found another another tube with an amplification factor of 9, the mighty 6528 tube that draws 5A. When is this going to end?
  
 Artsi, we need a chart of all the 6SN7 variants (with multiplication factor) so we know what to shop for. And this chart should include the 8, 12 and 25V variants as well. Here is a beginning list:
  
 6SN7
 6AS7
 6080
 6082
 6336
 6528
 12SX7
 12SN7
 6BX7
 6H13C
 5998
 421A?
 CV181
 ECC32
 6H8C
 6N8S
 1578
  
 Man, I am getting tired...


----------



## gibosi

mordy said:


> Artsi, we need a chart of all the 6SN7 variants (with multiplication factor) so we know what to shop for. And this chart should include the 8, 12 and 25V variants as well. Here is a beginning list:
> 
> 6SN7
> 6AS7
> ...


 
  
 I'm not sure it is quite correct to call all these tubes "6SN7 variants", but it is true that they are all double triodes with the same pin-out as a 6SN7GT.
  
 In addition to the ECC32, many folks also roll ECC33, ECC34 and ECC35 (a 6SL7 variant)
  
 The 25 volt 6SN7s I am aware of:
  
 25SN7
 1633
 13D1
  
 In addition to the 25 volt 13D1, there is a 6 volt 13D2, a special quality version of the 6SN7GT, and a 13D3, which is a 9-pin variant having the same pinout as a 12A-7. The 13D series tubes appear to be unique to Brimar.....
  
 And the beat goes on...


----------



## i luvmusic 2

I finally fixed my noisy Desktop power supply i just replaced the fan  and here it is dead quiet.Now i can't wait to receive my 12A regulator and Russian 6AS7.Can anyone please Post how to wire up 6SN7/6AS7 for Power tubes.


----------



## mojorisin35

hypnos1 said:


> Mordy....aren't you the lucky one - just 6N6P-IRs to relegate..._me_, it's 30P-DRs...OUCH!!!


 
 I would use the 30P-DRs if you are done with them as I have no plans to upgrade yet...


----------



## mordy

Hi i luvmusic 2,
  
 The 6SN7 tubes are just plug and play with an adapter (you need two of them):
  
 http://www.ebay.com/itm/221065459067?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT
  
 If the decorative ring prevents the adapters from getting seated in the sockets you need two socket savers to use as extenders. The adapters may be too wide to fit inside the diameter of the decorative ring and the pins do not reach into the sockets:
  
 http://www.ebay.com/itm/2PCS-9-PIN-vaccum-TUBE-SOCKET-SAVER-FOR-12AX7-12AU7-ECC82-ECC83-tube-audio-amps-/251350602537?pt=Vintage_Electronics_R2&hash=item3a85a9d329
  
  
 The 6AS7 tubes are the same pinout but they draw more current than the LD amp can handle. It is therefore imperative that you have an external power supply that supplies both tubes with the proper voltage and amperage; in this case 2.5A.  I do not have experience with this setup. You need some kind of adapter that allows you to connect the heaters of each tube separately to the appropriate voltage regulator and power supply.


----------



## CollectoR13

collector13 said:


> This is my conversion table for 6n6p to 6sn7!
> I would appreciate if you tell me if there is anything wrong with it!
> 
> 
> ...




Here is my wiring diagram I used for my adapters, full tutorial coming soon!


----------



## hypnos1

mordy said:


> Hi Hypnos1,
> 
> I am sure the C3g tubes are better. Thing is, I am happy with the 6BX7 tube. I am going to try some similar variants if I can get a good price.
> 
> As you suggested I am burning in the tube. Don't know how much an effect the extender/socket saver adapters have on sound, but they look cheaply made and are only supposed to last 200 times for changing the tubes . They are not deep enough to completely insert the octal adapter 9 pin bottom pins, and there is is a 2 mm gap between the adapters. Maybe good for ventilation LOL?


 
  
 Thanks, mordy, for encouragement/solace(!) re the C3GS tubes - I'm sure mab1376 is equally comforted!!...Let's not forget CollectoR13, who has also joined the club (and was very impressed with them...).
  
 As for adapters AND extenders, I can't help feeling they _must_ degrade the signal somewhat, which is why I persevered with making my own, using solid silver wire - acting also as the pins. But I can understand a reluctance to shy away from the task!
  
 Good luck with the other 'variants'...


----------



## hypnos1

mab1376 said:


> Those are the adapters i commissioned, they just put it up for other people to purchase. they will be using hypnos1's pinout he posted a while back.
> 
> They are pricy indeed, but they are the first built and handmade with skills i don't posses so i feel its worth it if the c3gs is as good as hypnos1 says. Plus i can finally get rid of the spider web of wires on my unit right now.


 
  
 Hi mab.
  
 Very resourceful of you to commission those adapters...certainly a lot easier than making your own! (But OF COURSE you possess the required skills...you just haven't flexed those particular muscles yet! - I myself am _by no means_ an electronics engineer, and with just a little practice - plus a bit of research on Google/youtube - it's amazing what you can achieve...with a modicum of care and patience thrown in, of course!).
  
 BTW...I hope you instructed them to link C3g pins 2 and 7 within the adapter?...
  
 I do hope they make a good job of them - I can't wait to hear your impressions...


----------



## gibosi

Broken ECC40
  
 For those who do not remember, the ECC40 was a Philips' design to replace the 6SN7GT with a miniature all-glass tube having reduced microphonics. I was listening to one of my favorites, made in Eindhoven in 1951, when suddenly the music faded and the filaments went dark. And then when I tried to remove it from the socket, the entire glass bottle broke off from the base... 
  
 Anyway, I thought some might be interested in seeing the internal structure in some detail. It is a very well-built tube, with thick micas, a number of vertical reinforcement rods and some curious structures, pieces of sheet metal attached to copper posts, located above the top mica. Some call these structures, "flags", but I can only guess at their intended purpose.


----------



## CollectoR13

So quick update now for the C3GS. 
I put around 50hrs on them now and they changed kind of noticable, much more rounded and dynamic. 
All I have to say is: endgame. 
As hypnos said in his first posts about these tubes, they are some of the best to put in a little dot. 
I think they are totally neutral but with a clarity I never imagined to get from the little dot, as it will never be the most high end amp, but wasn't supposed to be. 
What you get is a tube that doesn't color much and is absolutely true to the record, in combination with my sylvania 6sn7gt there is some serious punch and dynamic if the record delivers. 
That is also one of my main problems, bad albums sound bad. 
But I can live with it, as it is not like you never can't listen cause it sounds so bad, but rather like this: yep, could be better. (changing album) oh, yeah, this is how it goes!. 
My setup is now complete, it was a good decision to build these adapter, although building the adapters + price of the tubes was a little expensive, but however... its like the whole hifi hobby: pricey. 
In exchange you are taking the little dot to another level, clearly no comparison to other 6ak5 and 6n6p 's, my voskhods got totally destroyed by the siemens. 
But reading the positive experiences about the shuguang 6sn7, I am tempted to try better 6sn7's.... 
Must..... Resist.... lol


----------



## mordy

Hi G,
  
 Here is a more elaborate eulogy of an expired tube:
  




  
 ANNOUNCEMENT 
 A very regretful message from Kees has reached us. 
 One of his Arcturus 227 tubes has passed away. It died quietly and unexpectedly from a broken filament,  at the age of 79 years. 
 ARCTURUS Tube 227
 Born 1927
 Died February 2006 
  




  
 And speaking of old tubes, I couldn't resist showing pictures of this 6C21 tube:
  




  




 Some specs:

*Base*Sidecontact and top contact*Filament*Vf 8.2 Volts / If 17 Ampere / Direct /*Description*Special version of 1000T transmitting triode, intended as high-voltage radar pulse modulator. Capable of handling pulses of 15A at 30KV, with grid driven from -1000V cutoff to 1500V.


----------



## mab1376

hypnos1 said:


> Hi mab.
> 
> Very resourceful of you to commission those adapters...certainly a lot easier than making your own! (But OF COURSE you possess the required skills...you just haven't flexed those particular muscles yet! - I myself am _by no means_ an electronics engineer, and with just a little practice - plus a bit of research on Google/youtube - it's amazing what you can achieve...with a modicum of care and patience thrown in, of course!).
> 
> ...


 
 This is the pin mapping i used:
  

cg36ak5  1327354652617784
  
 Or the other way around to make it easier to read:
  

6ak5c3g16253148536472,7


----------



## Oskari

gibosi said:


> Anyway, I thought some might be interested in seeing the internal structure in some detail. It is a very well-built tube, with thick micas, a number of vertical reinforcement rods and some curious structures, pieces of sheet metal attached to copper posts, located above the top mica. Some call these structures, "flags", but I can only guess at their intended purpose.


 
  
 Sorry about your loss.
  
 That is interesting indeed. I believe those are heat radiators for cooling the grid wires. They are fixed to grid posts, aren't they?


----------



## hypnos1

collector13 said:


> So quick update now for the C3GS.
> I put around 50hrs on them now and they changed kind of noticable, much more rounded and dynamic.
> All I have to say is: endgame.
> As hypnos said in his first posts about these tubes, they are some of the best to put in a little dot.
> ...


 
  
 Hi CR13.
  
 Yep...about 50hrs make these babies _really_ shine - so glad you echo my findings. You summed things up nicely : that quality of 'clarity', along with what I term 'clean' sound is what I find most attractive about them (especially as they do everything else so well...). And yes again, poor recordings are shown _no_ mercy...which does not bother me _at all_!! And as for hi-res recordings, I am totally blown away (am sure the Psvane CV181-T MKII powers come into their own here especially...give out some hints come birthday or Christmas time! - I don't think the standard Shuguang 6SN7s would 'cut the mustard', but probably their CV181-z would be good). I plumped for the Psvanes as I like how they seemed to genuinely build on the Shuguang origins, and I do not regret one iota splurging out on them - plus, I love how they look!!
  
 It will be interesting to see how the Sylvania 6SN7GT-VT231s compare - I believe they're supposed to surpass the standard GTs?
  
 We await mab1376's assessment of the C3GSs with eager anticipation!...
  
 Glad you are enjoying the results of your time, effort and expense...HAPPY LISTENING...
  
  
  


>


----------



## hypnos1

mab1376 said:


> This is the pin mapping i used:
> 
> 
> cg36ak5  1327354652617784
> ...


 
  
 Good, good, mab...everything looks fine - now just the wait!...
  
 Patience, mon ami


----------



## mab1376

hypnos1 said:


> Good, good, mab...everything looks fine - now just the wait!...
> 
> Patience, mon ami


 
  
 Tubes are almost here from Germany, adapters are coming from China so who knows.
  
 Only time will tell.


----------



## gibosi

oskari said:


> Sorry about your loss.
> 
> That is interesting indeed. I believe those are heat radiators for cooling the grid wires. They are fixed to grid posts, aren't they?


 
  
 Fortunately, I have one more of these Eindhoven #5 tubes, so all is not lost. But for sure, I will be keeping my eye open for another so that I always have a backup. 
  
 And I am pretty sure these are copper grid posts. Looking through the holes in the plates, I can see a fine wire wrapped around these copper posts, and I assume that that is the grid wire I am seeing......


----------



## Oskari

gibosi said:


> Looking through the holes in the plates, I can see a fine wire wrapped around these copper posts, and I assume that that is the grid wire I am seeing......


 
  
 Absolutely.


----------



## Oskari

mordy said:


> Here is a more elaborate eulogy of an expired tube:


 
  
 Lol at the coffin.


----------



## i luvmusic 2

mordy said:


> Hi i luvmusic 2,
> 
> The 6SN7 tubes are just plug and play with an adapter (you need two of them):
> 
> ...


 
 Thank you for the links i have the 9 pin socket saver.I'am going to make my own. my idea is to  solder some wires on the socket tabs and at the end of the wires(Stranded wire) solder 18AWG solid copper wire and it's done i've done this with the 12AU7 adapter just plug the 18 AWG wire in the socket .Regarding the Power Supply i got plenty of current on my PS 15A(Desktop PS) and 12A regulator so no worries there.Again Thank You! 
  


collector13 said:


> Here is my wiring diagram I used for my adapters, full tutorial coming soon!


 
 So since i'm using a Enternal Power Supply i don't need to connect 6AS7 pin 7 and 8 to 6N6p pin 4 and 5 and 6N6p pin 9 no connection just to clarify before i create a fireworks.THANK YOU!


----------



## gibosi

i luvmusic 2 said:


> So since i'm using a Enternal Power Supply i don't need to connect 6AS7 pin 7 and 8 to 6N6p pin 4 and 5 and 6N6p pin 9 no connection just to clarify before i create a fireworks.THANK YOU!


 
  
 As you are going to use an external heater PS to provide power to the 6AS7, pins 7 and 8, you should definitely leave pins 4, 5 and 9 disconnected in the socket.
  
 Cheers


----------



## i luvmusic 2

gibosi said:


> As you are going to use an external heater PS to provide power to the 6AS7, pins 7 and 8, you should definitely leave pins 4, 5 and 9 disconnected in the socket.
> 
> Cheers


 
 Thank You!


----------



## mordy

Hi I luvmusic 2,
  
 Wishing you good luck in making the adapters. If possible, could you please take some pictures when you make them so that I can better understand how to wire in the power supply?
  
 I wonder if I could run the the LD MKIII with 6080 tubes as power tubes if I wired in an external power supply to supply each tube with 2.5A.
  
 Don't know what the amplification factor of 2 means in regard to using these tubes as power tubes.


----------



## gibosi

mordy said:


> Wishing you good luck in making the adapters. If possible, could you please take some pictures when you make them so that I can better understand how to wire in the power supply?
> 
> I wonder if I could run the the LD MKIII with 6080 tubes as power tubes if I wired in an external power supply to supply each tube with 2.5A.
> 
> Don't know what the amplification factor of 2 means in regard to using these tubes as power tubes.


 
  
 Pardon me for butting in here, but given Artsi's posting a few days ago, I would be very leery to try to use 6AS7s as power tube in your LD:
  
 http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/5565#post_10389835


----------



## mordy

What about as a driver tube?


----------



## gibosi

mordy said:


> What about as a driver tube?


 
  
 Given it's power requirements, I would be very leery. But I just don't know...... Perhaps Artsi can weigh in on this.


----------



## mordy

If the tube draws 2.5A, and my voltage regulator is rated 5A and the PS can put out more than 5A, why shouldn't it work? I have used the 6BX7 tube which draws 1.5A with very good results.


----------



## gibosi

Yes, you can easily meet the requirements for the heaters. But as Artsi mentioned several pages ago, there might be other factors to consider:
  
 "Now this is another real problem to use 6AS7's as powertube with LD. With 150ohm cathode resistors 6AS7 could hog 4-5 times the current what 6N6P uses! I think LD does not have enough anode current. And LD resistors can't stand the heat. Cathode resistors should be 10W."
  
 And so my hesitation is based on the possibility that these same concerns regarding the current draw of the cathode and anode could also be an issue in using this tube as a driver. I just don't know...  and so I remain leery....


----------



## henree

Received my 6HM5 sylvania tubes in the mail today. Put them into my Little Dot + and they are Sibilant with a capital Sssssssssssssss. I had to snatch that 4562 out very quick. Put my darker more smooth BB 2107 in and it calmed the treble down a great deal. These tubes are very Solid State sounding. Great bass authority and Excellent precision. I just need to know if the Sibilance or treble will smooth out over time. Is there another setting that can work. Gain is at the lowest setting. With my Denon D-7000 headphones.


----------



## hypnos1

collector13 said:


> Here is my wiring diagram I used for my adapters, full tutorial coming soon!


 
  
 Hi CR13.
  
 Better late than never!...Something I did notice, which I presume doesn't make any difference? - ANYBODY? - the triode _numbering_ looks different on the 6SN7 to most other tubes, ie pins 1, 2,3,4 are labelled triode 2 on the former, as opposed to triode 1. Just a quirk, I suppose...
  
 And I believe the 'S' on pin 9 is for 'shield' - also sometimes combined with grids as 'suppressor'...


----------



## gibosi

hypnos1 said:


> Better late than never!...Something I did notice, which I presume doesn't make any difference? - ANYBODY? - the triode _numbering_ looks different on the 6SN7 to most other tubes, ie pins 1, 2,3,4 are labelled triode 2 on the former, as opposed to triode 1. Just a quirk, I suppose...
> 
> And I believe the 'S' on pin 9 is for 'shield' - also sometimes combined with grids as 'suppressor'...


 
  
 Yes, the pin-out of 6SN7-type Octal tubes is completely different than the 9-pin 6DJ8s and 12AU7-type tubes. And it gets more complicated. The 7N7, the 8-pin Loctal version of the 6SN7GT, has a pin-out completely different from the Octal form. And the ECC40, the European 8-pin Rimlock version of the 6SN7GT, has a pin-out completely different from both the Octal and the Loctal forms.
  
 In the 9 pin socket, if you are running 6DJ8-type tubes, pin 9 is the electrostatic shield and should be tied to pin 8. If you are running 12AU7-type tubes, pin 9 is part of the heater circuit when running these tubes in the 6 volt mode.


----------



## kvtaco17

henree said:


> Received my 6HM5 sylvania tubes in the mail today. Put them into my Little Dot + and they are Sibilant with a capital Sssssssssssssss. I had to snatch that 4562 out very quick. Put my darker more smooth BB 2107 in and it calmed the treble down a great deal. These tubes are very Solid State sounding. Great bass authority and Excellent precision. I just need to know if the Sibilance or treble will smooth out over time. Is there another setting that can work. Gain is at the lowest setting. With my Denon D-7000 headphones.


 
 Mine were far from sibilant... I assume the tubes you have are the tall bottles?


----------



## DogMeat

before, or after run-in period?


----------



## MIKELAP

henree said:


> Received my 6HM5 sylvania tubes in the mail today. Put them into my Little Dot + and they are Sibilant with a capital Sssssssssssssss. I had to snatch that 4562 out very quick. Put my darker more smooth BB 2107 in and it calmed the treble down a great deal. These tubes are very Solid State sounding. Great bass authority and Excellent precision. I just need to know if the Sibilance or treble will smooth out over time. Is there another setting that can work. Gain is at the lowest setting. With my Denon D-7000 headphones.


 
 i have a pair of Lawton modded Denon D-5000 and  sometimes there was  sibilance, but depending on the tune played do yours always sound like that with those tubes or just on certain tracks .


----------



## mordy

Hi,
  
 Continuing my exploit of possible octal driver tubes for the the LD MKIII. Found a 12SN7GT Westinghouse tube and bought it mainly because it was inexpensive - less than $4 shipped. This tube has a side getter and the code 5R13, (maybe April 1955?).
  
 Was just going to see if it lights up and makes sound and check out other tubes in this lot, but I can't get myself to pull it out of the socket; it is that good. Being fed a steady diet of 12.6V what is striking is the punchy, tuneful and detailed midrange bass as well as the quickness and liveliness of the tube.
  
 For power tubes I am using two RCA 6SN7GT tubes. The 12SN7 draws 0.3A and has an amplification factor of 20 so we all can breathe easy - no worries about compatibility.
  
 So far the only cons are a midrange that is very good but not sweet and a slight sibilance in the treble; however, these characteristics may very well change after burn in.


  
 It is amazing - it is hard to find a mediocre 6SN7 family tube.....


----------



## henree

mikelap said:


> i have a pair of Lawton modded Denon D-5000 and  sometimes there was  sibilance, but depending on the tune played do yours always sound like that with those tubes or just on certain tracks .


 
 This is my first pair of these types of tubes. I would not have the d7000 if they always sounded this crisp. There was no info on ebay about these tubes. It could be NOS. Is it normal for certain tubes to be harsh when 1st listenig to them? Hopefully the 6hm5 smooth out over time.


----------



## MIKELAP

henree said:


> This is my first pair of these types of tubes. I would not have the d7000 if they always sounded this crisp. There was no info on ebay about these tubes. It could be NOS. Is it normal for certain tubes to be harsh when 1st listenig to them? Hopefully the 6hm5 smooth out over time.


 
 Let them simmer for a while . For my part it depends on the track they are not sibilant usually.  Some tubes like the Voskhod 6ZHIP-EV its been reported that they need up to 100hours to simmer down .so i would say yes


----------



## gibosi

henree said:


> This is my first pair of these types of tubes. I would not have the d7000 if they always sounded this crisp. There was no info on ebay about these tubes. It could be NOS. Is it normal for certain tubes to be harsh when 1st listenig to them? Hopefully the 6hm5 smooth out over time.


 
  
 It is likely that your tubes are NOS, and therefore, it is likely that they will change for the better after 20 hours, or more. Typically, after burning in, bass tightens up and highs smooth out. My experience was with the GE 6HM5, but other posters always spoke very highly of the Sylvania.


----------



## gibosi

mordy said:


> Continuing my exploit of possible octal driver tubes for the the LD MKIII. Found a 12SN7GT Westinghouse tube and bought it mainly because it was inexpensive - less than $4 shipped. This tube has a side getter and the code 5R13, (maybe April 1955?).
> 
> Was just going to see if it lights up and makes sound and check out other tubes in this lot, but I can't get myself to pull it out of the socket; it is that good


 
  
 I have yet to purchase a Westinghouse 6SN7. My thinking is that Westinghouse never manufactured this tube, but simply sourced from others and relabeled. But I am not sure.....
  
 But of course, a good tube is a good tube, regardless of label.


----------



## MIKELAP

Found this great case very good condition on Ebay


----------



## TrollDragon

Nice Case!


----------



## MIKELAP

Thanks ,had the tubes out of the boxes took a while to put them back in but now there in one place .


----------



## hypnos1

gibosi said:


> Yes, the pin-out of 6SN7-type Octal tubes is completely different than the 9-pin 6DJ8s and 12AU7-type tubes. And it gets more complicated. The 7N7, the 8-pin Loctal version of the 6SN7GT, has a pin-out completely different from the Octal form. And the ECC40, the European 8-pin Rimlock version of the 6SN7GT, has a pin-out completely different from both the Octal and the Loctal forms.
> 
> In the 9 pin socket, if you are running 6DJ8-type tubes, pin 9 is the electrostatic shield and should be tied to pin 8. If you are running 12AU7-type tubes, pin 9 is part of the heater circuit when running these tubes in the 6 volt mode.


 
  
 Yes indeed gibosi, all these different pin-outs make for _very _fiddly adapter-construction!
 Actually - as perhaps I didn't word it properly - I was wondering if, due to the different triode# attribution (as always shown by a 'from below' view of tube base), it is OK to basically link the 6SN7's a1, g1, k1, h1 to LD's a2, g2,k2,h2, and vice-versa....the pin routing being much easier this way?...
  
 Cheers!


----------



## gibosi

hypnos1 said:


> Yes indeed gibosi, all these different pin-outs make for _very _fiddly adapter-construction!
> Actually - as perhaps I didn't word it properly - I was wondering if, due to the different triode# attribution (as always shown by a 'from below' view of tube base), it is OK to basically link the 6SN7's a1, g1, k1, h1 to LD's a2, g2,k2,h2, and vice-versa....the pin routing being much easier this way?...


 
  
 In the special case of power tubes, I suspect this would be OK. It is my understanding that the LD parallels the 6H30's two triodes, essentially transforming the 6H30 from a double triode to a single triode, so maintaining the correct internal left and right orientation would no longer matter. And therefore, it would be the same when you plug a 6SN7 into the LD. The two triodes are paralleled into one and the internal orientation no longer matters. So it *should* be fine...


----------



## i luvmusic 2

mordy said:


> Hi I luvmusic 2,
> 
> Wishing you good luck in making the adapters. If possible, could you please take some pictures when you make them so that I can better understand how to wire in the power supply?
> 
> ...


 
 Sure i will post a picture as soon as it's done.For 6AS7 i should asked before i bought them will it's too late now it's been shipped and i'am willing to try it as a Power tube and driver tube as will.Someone has to try it and that would be me.


----------



## hypnos1

gibosi said:


> In the special case of power tubes, I suspect this would be OK. It is my understanding that the LD parallels the 6H30's two triodes, essentially transforming the 6H30 from a double triode to a single triode, so maintaining the correct internal left and right orientation would no longer matter. And therefore, it would be the same when you plug a 6SN7 into the LD. The two triodes are paralleled into one and the internal orientation no longer matters. So it *should* be fine...


 
  
 Thanks gibosi...suspected as much. Just have to get ordering my silver wire now, and can proceed with more confidence! Will be interesting to see how my adapters compare to the bought ones (will be rather miffed if there is no difference after all!!).
  
 Cheers once more.


----------



## mordy

Hi G,
  
 Seems to me that Westinghouse did manufacture their own vacuum tubes. Here is a snippet from an interview:
  
 "The war ended and then came a time when things were going very slowly and progress was not to my liking. I got an invitation then from Westinghouse. Westinghouse by the consent decree after at about 1930 had to stay out of the receiving tube business. But by 1950, they could make receiving tubes again. Westinghouse wanted to make not only receiving tubes but more power tubes, cathode tubes, pick-up tubes and what have you — the whole shebang! So I accepted the job and became chief engineer of the newly created Westinghouse tube division. I had a marvelous time because I always wanted to build something from scratch. I hand-picked the engineers, I built up a patent department for the tube division and so forth. It was wonderful. We started to work first in Bloomfield and then the location was changed in 1952 to Elmira in New York State, where they built a new factory. After several years the aims of the company changed. The management in East Pittsburgh had different ideas. There was a slump of business, and I thought of leaving the company. I got an early retirement that was accepted, and I was free. Then I looked around. I had a few offers, but RCA invited me and discussed things with me and I felt inasmuch as I knew RCA and most of the personnel very well I would be more effective there than if I would go somewhere else and start from scratch. So I became a consultant for RCA, worked on semiconductors on germanium, silicon, on methods of making transistors. I had a grand glorious time."
  
 Here is the link to a lengthy interview with a tube pioneer:
  
 http://www.ieeeghn.org/wiki/index.php/Oral-History:Ernst_Lederer


----------



## gibosi

mordy said:


> Seems to me that Westinghouse did manufacture their own vacuum tubes.


 
  
 Yes, this strongly suggests that Westinghouse made tubes in the 1950s. And this also explains why we don't see any Westinghouse tubes in the 1940's, during the war.  So I guess I will have to get myself a nice Westinghouse tube.


----------



## gibosi

Mordy,
  
 As you search for interesting tubes to roll as drivers, I would suggest you take another look at your current holdings. If I am not mistaken you have a couple different 6H30-type power tubes that have recently been displaced by 6SN7s?


----------



## mordy

Hi Gibosi,
  
 Are you suggesting that I try the 6N6P, 6N6P-i, 6N6P gold grid and 6N6P-IR as driver tubes? Didn't think of that. I seem to remember that AFB tried his 6H30-DR tube as a driver with good results.
  
 Sounds interesting - I'll give it a shot when I finish burning in the 12V Westinghouse tube. Thanks,


----------



## gibosi

mordy said:


> Hi Gibosi,
> 
> Are you suggesting that I try the 6N6P, 6N6P-i, 6N6P gold grid and 6N6P-IR as driver tubes? Didn't think of that. I seem to remember that AFB tried his 6H30-DR tube as a driver with good results.
> 
> Sounds interesting - I'll give it a shot when I finish burning in the 12V Westinghouse tube. Thanks,


 
  
 Exactly! 
  
 As the 6H30-DR requires an external heater PS to be used as a driver, AFB was not able to try his... But I know he wanted to....


----------



## Oskari

gibosi said:


> ... maintaining the correct internal left and right orientation ...


 
  
 The tube doesn't really care which triode system you use for left contra right channel.


----------



## gibosi

oskari said:


> The tube doesn't really care which triode system you use for left contra right channel.


 
  
 As I don't have power tubes in my hybrid, I always try to err on the side of caution when giving my 2 cents. But now that you mention it, it is obvious: The tube doesn't care. lol


----------



## hypnos1

oskari said:


> The tube doesn't really care which triode system you use for left contra right channel.


 
  
 Thanks Oskari (and gibosi) for stating what I should have known for sure...ah well, can't ever be _too_ careful when making adapters!...
  
 Cheers.


----------



## happy5930

They sourced years ago for their transceivers. I doubt they ever manufactured their own.


----------



## mab1376

I should have my c3g tubes and adapters potentially tomorrow, Monday at the latest based on tracking!


----------



## gibosi

ECC40
  
 I wonder... Am I the only one rolling these tubes?
  
 Anyway, I now have about 15 of these in my possession and thought I might share some of my observations.
  
 In the late 1940's and into the 1950's, these were manufactured in at least 5 Philips factories: 
  
 Eindhoven, Holland (factory symbols: "4", "5" and "H". The "H" appears to be a miss-shaped 4, as they look and sound the same to me.)
  
 Sittard, Holland (factory symbol "+")
  
 Chartres, France (factory symbol "±", that is a "+" on top of a "-")
  
 Suresnes, France (factory symbol "F")
  
 Hamburg, Germany (factory symbol "D")
  
 And in addition to Philips, Tungsram also made this tube. However, I have yet to spend any quality time with mine.
  
 By the late 1960's it appears that most of Philips' ECC40 production seems to have been located in Chartres, as the vast majority of the tubes I see from that time were manufactured there. And into the 1970's, some tubes were also manufactured at Suresnes and the Ediswan factory in Britain, according to one vendor, but I do not have any of these, so I am not sure.
  
 Generally, I like the Chartres-made tubes the least. I find the highs to be a bit over the top. The Hamburg-made tubes have the airy highs and dryish mids typical of German-made tubes, and although, this is not my favorite sound signature, still, it is quite nice. And the Holland-made tubes seem to do everything quite right (to my ears).
  
 Last night I spent several hours with a Suresnes-made tube and was surprised to discover that I really liked it. Interestingly, the Suresnes-made tubes look rather different than the tubes from all the other Philips factories. The bottle is shorter, the plates are somewhat different, and the metal work above the top mica and below the bottom mica is also different.
  
 1952 Suresnes production compared to 1955 Eindhoven
  

  

  
 And the ECC40 metal-base variants also look different.
  
 Early 1950's Suresnes production compared to 1951 Hamburg
  

  
 I hope others will try these tubes and let us know what they think. To begin, I can easily recommend the Suresnes, Hamburg and the various Holland tubes.


----------



## hypnos1

mab1376 said:


> I should have my c3g tubes and adapters potentially tomorrow, Monday at the latest based on tracking!


 
  
 Hey mab, I don't know who's more like the proverbial "cat on a hot tin roof" - you or _me_!! Can't wait!!...
  
 As for me, my Sylvania 6SN7GT-VT231s are waiting in my local post office, so tomorrow we could both be having an interesting time :C3GS vs ???..., and Psvane CV181-T MKII v Sylvania. The suspense is just TOO much...this rolling game sure does get the juices flowing (not to mention nervous exhaustion!!).
  
 GOOD LUCK!


----------



## i luvmusic 2

I just noticed the voltage reading on my multi meter that the length of the wires are affecting the voltage reading at 12'' = 6.35V and at 20" = 5.98V.
 Does it mean if i connect my adapter wires closer to the PCB would have a little bit better sound maybe.


----------



## i luvmusic 2

Or the shorter the signal path the better?


----------



## gibosi

i luvmusic 2 said:


> I just noticed the voltage reading on my multi meter that the length of the wires are affecting the voltage reading at 12'' = 6.35V and at 20" = 5.98V.
> Does it mean if i connect my adapter wires closer to the PCB would have a little bit better sound maybe.


 
  
 Again, I am certainly not an expert, but it is hard for me to believe that 8 inches of wire causes that large of a voltage drop. I have to believe that something else is causing this. But there are others here who know much more than I....


----------



## mordy

I find that different tubes give different voltage readings at the tube pins. When I change a tube I adjust the pot to read the correct voltage at the tube. The LED readout or multimeter reading is usually a bit higher measured at the voltage regulator. As an example, the 6P6N-IR as a driver needs 6.3V, but the voltage regulator value has to be 6.45V to achieve this at the breadboard socket in my case.
  
 Regarding wires I am skeptical. IMHO a foot or two should not make a difference. Me thinks some fancy interconnects work as tone controls....Of course, then you have silver.....


----------



## i luvmusic 2

I tried again measuring using even longer wires and again it dropped even lower.Same here G i'm not an expert but  this suggest to me that the shorter the signal path the better maybe no effect on sound quality.You mentioned about 6N6 as a driver tube i would like to try these if you or anybody can post the pin connections since Mordy(sorry Mordy) is having fun with his new driver tubes while i'm bored waiting for my parts from Chinada.Thanks!


----------



## gibosi

i luvmusic 2 said:


> I tried again measuring using even longer wires and again it dropped even lower.Same here G i'm not an expert but  this suggest to me that the shorter the signal path the better maybe no effect on sound quality.You mentioned about 6N6 as a driver tube i would like to try these if you or anybody can post the pin connections since Mordy(sorry Mordy) is having fun with his new driver tubes while i'm bored waiting for my parts from Chinada.Thanks!


 
  
 6H30-type tubes have the same pin-out as a 6DJ8.


----------



## i luvmusic 2

gibosi said:


> 6H30-type tubes have the same pin-out as a 6DJ8.


 
 So i can connect pin 4 and 5 to  - and + from external PS and pin 9 no connection?Thanks!


----------



## i luvmusic 2

Sorry to say that i will be busy listening to 6n6 driver tube Holy schiit it works no hum dead silent...


----------



## i luvmusic 2

mordy said:


> I find that different tubes give different voltage readings at the tube pins. When I change a tube I adjust the pot to read the correct voltage at the tube. The LED readout or multimeter reading is usually a bit higher measured at the voltage regulator. As an example, the 6P6N-IR as a driver needs 6.3V, but the voltage regulator value has to be 6.45V to achieve this at the breadboard socket in my case.
> 
> Regarding wires I am skeptical. IMHO a foot or two should not make a difference. Me thinks some fancy interconnects work as tone controls....Of course, then you have silver.....


 
 That could be  it i cahnged the tubes.


----------



## TrollDragon

Grey Goose FTW!


----------



## gibosi

i luvmusic 2 said:


>


 
  
 I have to admit, I really like the "Grey Goose" adapter. And I wonder if that bottle would fit over the two test sockets? If so, the bottom could be cut off, the bottle placed over the two test sockets, and the wires routed to a socket mounted on top? This might be just as classy as some of the brass steampunk adapters we have seen.


----------



## i luvmusic 2

No i think i will put the LD 1 inside the bottle in that way you don't see any wires just the tube on top.
	

	
	
		
		

		
			




 This 6N6 it remind me of 6HM5 only have a bigger soundstage.


----------



## hypnos1

So, the Sylvania 6SN7GT-VT231s are in (as powers), and they certainly are VERY good (after an awful start with one tube giving the most horrendous hum - said tube having the slightest loose play in its base, but with a twist it's gone...not very happy, but they've obviously had a good bit of use and I didn't pay much for them...).
  
 It's early days re trialling my different test CDs, but first impressions are not _quite_ giving me the same "tingle" factor as the Psvanes - too early to put my finger on all the reasons, but the main difference seems to lie in the overall clarity of presentation. The soundstage is good, but somehow _very slightly_ compressed in comparison - the C3gS magic in this area is not quite 100%. Possibly this is partly a by-product of the bass being _deep_ but with not quite the same _detail_ and finesse as the Psvanes. They can't seem to handle fast bass/drum runs as well, either.
 Treble on the whole is very well handled, with occasional slight tendency to sibilance in certain tracks.
  
 Have been listening to my Clannad 'Past Present' while composing this, and some tracks come over well but others the Sylvanias seem to be struggling with...prolonged listening, I fear, is going to be a bit of a mixed bag. At the moment, I feel they are not doing the C3gSs full justice...perhaps they need to be partnered with other drivers for better 'synergy'.
  
 However, I shall continue with the testing and see how things develop.


----------



## gibosi

hypnos1 said:


> So, the Sylvania 6SN7GT-VT231s are in (as powers), and they certainly are VERY good (after an awful start with one tube giving the most horrendous hum - said tube having the slightest loose play in its base, but with a twist it's gone...not very happy, but they've obviously had a good bit of use and I didn't pay much for them...).
> 
> It's early days re trialling my different test CDs, but first impressions are not _quite_ giving me the same "tingle" factor as the Psvanes - too early to put my finger on all the reasons, but the main difference seems to lie in the overall clarity of presentation. The soundstage is good, but somehow _very slightly_ compressed in comparison - the C3gS magic in this area is not quite 100%. Possibly this is partly a by-product of the bass being _deep_ but with not quite the same _detail_ and finesse as the Psvanes. They can't seem to handle fast bass/drum runs as well, either.


 
  
 I am not completely surprised as the Sylvanias are not as balanced as your Psvanes appear to be. As I find this tube to be somewhat dry and bass deficient, I can imagine that it would pair very well with a warm, bassy gray-glass RCA. But it appears that your C3s have better synergy with a more balanced output tube.


----------



## gibosi

Received a Bendix Eclipse-Pioneer 2C51 / 396A / 5670 in the mail today. (It seems that I am the only one rolling these tubes as well?)
  
 The Bendix is considered one of the best and most desirable of the 2C51s and as I found this one at a good price, I grabbed it. First impressions, very good bass and treble, nice wide sound stage and lush mids. It sounds great with my HD 700s. 
  
  

  
 The vendor packed it very well, and with a surprising sense of humor. When I brought the mail in and opened the package, my wife asked, "Oh, did you buy me a new ring?" lol


----------



## mab1376

Got my C3gS' running, initial impressions are very forward presentation, sort of in your face. I'm hoping the soundstage will widen a bit with some burn in.
  
 Other than that they are ridiculously detailed and have very extended highs almost like cymbals are in the room with you, bass is very tight a well defined and mids are amazing, acoustic guitar sounds very realistic.
  
 Tracks i use to test:
  
 Bass: Jamiroquai - Cosmic Girl
 Mids: Rodrigo y Gabriela - Foc
 Percussion (highs): Daft Punk - Contact
 Soundstage: Queens of the stone age: No One Knows (Lullabies to Paralyze Bonus Cd Live from Earthlink in Atlanta, GA)


----------



## gibosi

I really want to try these C3gs.... someday.... 
  
 Someone asked today what my favorite tubes are.
  
 In no order:
  
 2C51 = 1951 Bendix. (Until the arrival of the Bendix today, I would have said 1951 Western Electric)
 6DJ8 = 1975 Voskhod 6N23P
 ECC40 = Any of the Holland-made early 1950's tubes
 6SN7 = 1944 Sylvania JAN-CHS-6SN7W
 ECC80 = 1950's-1960's Holland made
  
 All these tubes are more similar than different. All have very good bass and highs, with lush, somewhat warm, musical mids. I could be happy with any one of them, but for sure, it is nice to have all of them. 
  
 That said, I have had my HD-700s for less than two weeks, and I am still trying to get my mind around what I am hearing. They are very, very different than my HE-300s. And in fact, the only 6SN7 I have heard with these headphones is the Sylvania 6SN7W. As I get more comfortable with these headphones and slowly roll through the rest of my tube collection, it is certainly possible that my list of favorites might change.


----------



## mordy

Hi I luvmusic 2,
  
 Enjoyed your "grey market" adapter LOL. Did you check out how a Scotch bottle adapter sounds?
  
 Anyhow, on Gibosi's suggestion I am trying out my stash of 6N6P family tubes. Briefly tried my best _power_ tube before the 6SN7 era - the 6N6P-IR. This tube did not match well with my two RCA 6SN7 power tubes and sounded thin and unengaging.
  
 Next tried my least desirable power tube, the 6N6P as a driver tube. Surprise - it sounds very good! Musical and good bass, maybe bass is boomy - gotta give it more time. Then the P-i and gold grid.....


----------



## mordy

Hi G,
  
 Speaking of 2C51 tubes, there is a 12V octal dual triode called 2C52, which was designed for aircraft servo-amplifiers. Anybody has experience with this tube? Perhaps similar to the 12SX7 tube....


----------



## Nic Rhodes

the 2C52 is a new one on me but if you like the 2C51 sound (massively under rated tube imho) look out for the LM Ericson european ones (gold pins) as the best I found though they are getting pricey now but you may get lucky still with effort searching. The wild card is the Reflector 6N3P DR, note the DR bit which is the 'most rugged' Russian variant and still not silly money. The 2C51s however are a very good quality across all the different manufacturers.


----------



## i luvmusic 2

mordy said:


> Hi I luvmusic 2,
> 
> Enjoyed your "grey market" adapter LOL. Did you check out how a Scotch bottle adapter sounds?
> 
> ...


 
 Yup the Grey adds a little touch of warm into the sound.I tried the 6N6P and like what i said before it remind of 6HM5 and pair well with my 6N6p-i driver tube so now i can't wait for my Russian 6AS7,6N9C and the RCA 6SN7 driver tubes oh and the Parts coming from Chinada.


----------



## gibosi

mordy said:


> Hi G,
> 
> Speaking of 2C51 tubes, there is a 12V octal dual triode called 2C52, which was designed for aircraft servo-amplifiers. Anybody has experience with this tube? Perhaps similar to the 12SX7 tube....


 
  
 The 12SX7 is electrically identical to the 12SN7. The only difference is that it was designed to be less microphonic. So yes, it is simply a premium version of the 12SN7.
  
 The 2C52 is a high mu dual triode. While the 12SN7 has a mu of about 20, similar to a 12AU7, the 2C52 has a mu of about 100, similar to a 12AX7. This tube should work fine in our LDs as we have successfully used the high mu 12AX7 before and the pin-out is the same as the 12SN7.


----------



## hypnos1

mab1376 said:


> Got my C3gS' running, initial impressions are very forward presentation, sort of in your face. I'm hoping the soundstage will widen a bit with some burn in.
> 
> Other than that they are ridiculously detailed and have very extended highs almost like cymbals are in the room with you, bass is very tight a well defined and mids are amazing, acoustic guitar sounds very realistic.
> 
> ...


 
  
 Hi mab.
  
 Glad to hear you are now in C3gS land...congrats.
  
 Am VERY perplexed re your _very_ forward presentation!...I do hope your adapters are not going to hold back these tubes! However, given that the C3gS need 30-50 hrs to _really_ shine - not to mention the adapters - I am pretty confident that all will be (more than) well very soon. Soundstage certainly does develop, and all those other qualities you mentioned integrate to an astonishing degree...have no fear, mon ami...
  
 BTW - what powers are you using? My Psvanes are providing _wonderful_ 3-dimensionality - could almost swear it's *4* dimensions! But the Sylvania 6SN7GT-VT231s, good though they are, cannot compete in this area especially.
  
 Look forward to hearing how things progress...and I make this promise...if that soundstage does _not_ open up (but I am sure it _will_), I shall make you some silver wire adapters...gladly...
  
 Cheers!


----------



## henree

Just wanted to follow up with the 6HM5 sylvania tubes. I found out that they are truly NOS tubes. And that crispy sibilance is normal with never before used tubes. They are really impressing me. So much effortless power and dynamism. They are superior to the Mullard 8083's in almost every way except for Musicality. I will still use the 6HM5 as my primary to go to tubes. Is there anything else that is more musical I should try. For my Little Dot + hybrid. Preferably tubes that are plug and play. I like Smooth highs and deep tight bass. Colored musical tubes where my preferences lie.


----------



## gibosi

You have the Sylvania 6HM5 and as I haven't heard them, I can't say for sure how other tubes compare. But since 6HM5 are cheap, you might want to try the other tall-bottle types, GE and Yugoslavia EI.
  
 The 6DT6 (set your amp to EF92) is worth trying. I found the RCA and Tung Sol to be very good. And I believe that others liked the Sylvania.
  
 Again, these will all likely be NOS, and as you have noticed, you will need to burn them in.


----------



## hypnos1

gibosi said:


> I am not completely surprised as the Sylvanias are not as balanced as your Psvanes appear to be. As I find this tube to be somewhat dry and bass deficient, I can imagine that it would pair very well with a warm, bassy gray-glass RCA. But it appears that your C3s have better synergy with a more balanced output tube.


 
  
 Yo gibosi...that 'dryness' is surely what is killing the C3gS magic. The delicious reverb and decay, especially on bass drum/piano/acoustic string notes, is just not being delivered by the Sylvanias (and yet the VT-231s are normally supposed to be so good at nearly everything, no?). And this alone methinks would have a very negative effect on the wonderful, spacious soundstage...the slightly more emphasis on mids, though sometimes very attractive, also contributes towards this effect I am sure - why is there always a trade-off with all the things we love?! Something to do with "you can't have your cake _and_ eat it?...Life's a b***h, ain't it?...
 Ah well, mustn't be greedy I suppose. All I can say is I have been EXTREMELY lucky to find the Psvanes matching the C3gSs so brilliantly - perhaps it's their developers' clever remit to combine the qualities of both the CV181 _and _ 6SN7. Whatever, they are proving to be way beyond what I (and I am sure many others) was expecting from Far Eastern tube makers...


----------



## mab1376

hypnos1 said:


> Yo gibosi...that 'dryness' is surely what is killing the C3gS magic. The delicious reverb and decay, especially on bass drum/piano/acoustic string notes, is just not being delivered by the Sylvanias (and yet the VT-231s are normally supposed to be so good at nearly everything, no?). And this alone methinks would have a very negative effect on the wonderful, spacious soundstage...the slightly more emphasis on mids, though sometimes very attractive, also contributes towards this effect I am sure - why is there always a trade-off with all the things we love?! Something to do with "you can't have your cake _and_ eat it?...Life's a b***h, ain't it?...
> Ah well, mustn't be greedy I suppose. All I can say is I have been EXTREMELY lucky to find the Psvanes matching the C3gSs so brilliantly - perhaps it's their developers' clever remit to combine the qualities of both the CV181 _and _ 6SN7. Whatever, they are proving to be way beyond what I (and I am sure many others) was expecting from Far Eastern tube makers...


 
  
 Hey Hypnos1,
  
 How do i get the black metal shields off of the c3gs'?


----------



## hypnos1

mab1376 said:


> Hey Hypnos1,
> 
> How do i get the black metal shields off of the c3gs'?


 

 Am off to bed now, mab, but tomorrow I will take some photos of the procedure - they do look much prettier with them off!!
  
 Cheers.


----------



## henree

gibosi said:


> You have the Sylvania 6HM5 and as I haven't heard them, I can't say for sure how other tubes compare. But since 6HM5 are cheap, you might want to try the other tall-bottle types, GE and Yugoslavia EI.
> 
> The 6DT6 (set your amp to EF92) is worth trying. I found the RCA and Tung Sol to be very good. And I believe that others liked the Sylvania.
> 
> Again, these will all likely be NOS, and as you have noticed, you will need to burn them in.


 
 Gibosi, What do you think about the Amperex 6BY6 tubes? They are heptodes. Is there any specific sonic characteristics that seperate the Heptodes from the Triodes?


----------



## gibosi

hypnos1 said:


> Yo gibosi...that 'dryness' is surely what is killing the C3gS magic. The delicious reverb and decay, especially on bass drum/piano/acoustic string notes, is just not being delivered by the Sylvanias (and yet the VT-231s are normally supposed to be so good at nearly everything, no?).


 
  
 From what I have read, "VT-231" is nothing more than an inventory number used by the US Navy during WWII. All you can really infer from this designation is they were produced in the 1940's in support of the war. Evidently, they are identical to 6SN7GTs made during the 1940's for civilian use.
  
 My impression is the Sylvania VT-231 is prized by those who combine more than one 6SN7 together to counterbalance deficiencies in each to achieve a desired sonic signature. But as your C3gs are very linear, and likely have no significant deficiencies, I believe they require an output tube with more balance than the Sylvania. If you are still interested in trying old-stock 6SN7, I would suggest a pair of Raytheon VT-231. There are two versions, and the one with 2 free support posts and flat plates seems to be preferred over the other. Or a pair of Tung Sol "Mouse Ears." In my experience, both of these have pretty good balance.


----------



## gibosi

henree said:


> Gibosi, What do you think about the Amperex 6BY6 tubes? They are heptodes. Is there any specific sonic characteristics that seperate the Heptodes from the Triodes?


 
  
 First, you should realize that in order to use pentodes and heptodes in the LD, it is necessary to convert them into triodes. The LD does this on the circuit board for EF91, 92 and 95. The problem with heptodes is there are two more grids to deal with. It is certainly possible to run 6BY6, 6BE6 and 6CS6 heptodes in our Little Dots, and in fact a number of us, including myself have done this. The easiest way is to run them in the EF92 mode.
  
 In my experience, with very few exceptions, such as the C3gs, the only advantage to converting pentodes and heptodes into triodes is cost. These tubes are typically very cheap. The downside is that in the conversion process, linearity decreases and distortion increases. That said, it is completely harmless and as cheap as they are, why not?


----------



## gibosi

And I should add, one of the reasons the 6HM5 sounds better than the Mullard 8083 is the 6HM5 is a true triode. Prior to running double triodes, the only tube I found that was better than the 6HM5 is another true triode, tubes in the 6AV6 / 6AT6 / 6AQ6 family. These three tubes differ only slightly, and in our LDs, they are essentially identical. Again, these are true triodes. However, there are also two diodes in the same bottle. So we cut off the diodes, pins 5 and 6, and now we have true triodes that run perfectly wonderful in the EF92 mode.
  
 Food for thought....


----------



## mab1376

hypnos1 said:


> Am off to bed now, mab, but tomorrow I will take some photos of the procedure - they do look much prettier with them off!!
> 
> Cheers.


 
 Thanks, I appreciate it!


----------



## henree

gibosi said:


> First, you should realize that in order to use pentodes and heptodes in the LD, it is necessary to convert them into triodes. The LD does this on the circuit board for EF91, 92 and 95. The problem with heptodes is there are two more grids to deal with. It is certainly possible to run 6BY6, 6BE6 and 6CS6 heptodes in our Little Dots, and in fact a number of us, including myself have done this. The easiest way is to run them in the EF92 mode.
> 
> In my experience, with very few exceptions, such as the C3gs, the only advantage to converting pentodes and heptodes into triodes is cost. These tubes are typically very cheap. The downside is that in the conversion process, linearity decreases and distortion increases. That said, it is completely harmless and as cheap as they are, why not?


 
 Thanks for the info. Generally speaking would the 6BY6 be a step down from the Sylvania 6HM5 tubes I have right now? The 6BY6 don't need to be altered other than changing the jumpers correct? I don't mind my music being colored. I just want a  very musical presentation first.


----------



## gibosi

Ummm... Again, as I said above, prior to running double triodes, the 6HM5 and 6AV6 were the best tubes I tried. So in my opinion, the 6BY6 would be a step down....
  
 But hey! Heptodes are cheap! Have some fun! Buy a bunch and see what YOU think! 
  
 And in fact, you can safely run these tubes in either the EF95 or EF92 setting. (We also tried strapping them in a couple of different ways, which resulted in a total of 4 different triode-conversion configurations.) So try both EF95 and EF92 and you will be able to hear for yourself what different triode-conversion configurations do to the sound. And you will be able to judge for yourself how these converted triodes compare to the Sylvania 6HM5, a true triode.
  
 Cheers


----------



## hypnos1

mab1376 said:


> Hey Hypnos1,
> 
> How do i get the black metal shields off of the c3gs'?


 
  
 Right then mab, here we go...don't want to sound like Mother, but please take VERY careful note of the pointers...would hate for anything to go amiss with these little treasures:
  
 1. The bottom outer rim of the canister is folded (fairly soft metal) over the metal protective tube base. So, using a pair of small (preferably) pliers, gradually and gently prise that rim away, as per photo #1 - you don't need to pull it _too_ far away :
  

  
 At this point you can see clearly the different-shaped cut-out for orientating the base to tube (church window as opposed to round)...
  
  
 2. You may well have to gently 'wiggle' the metal base and/or adjust the prised rim to lift out said base. *NOTE* : there are 3 washers - over pins 2,5, and7 (not exactly sure why...perhaps something to do with heat transference?). They might possibly come adrift as you remove the base...
 The protruding "locator" on the side of the central metal cylinder corresponds to the mid-point between pins 1 and 8.
 This mid-point is marked on the glass bottom by a _tiny_ pimple, located at the 6 o'clock position in photo #2 - the pins running clockwise from #1(to the left of mid-point as you look from below)...
  

  
 Note the 'church window' of the metal base sits over pin #6 - (I'm sure 2, seated either side of the 'mid-point' would have been _much_ less confusing lol!).
  
 3. You now have 2 options, of course...#1: pop it straight into the adapter, which would need EXTREME care - you would have to clearly mark that mid-point on the side of the tube, to ensure correct location with the indent on the adapter. Also, that protruding glass tube seal looks rather vulnerable - probably no trouble when pushing the tube _in _(still with care..), but potentially a problem if having to waggle hard to pull it _out! _
 Option 2 is much safer, of course : glue the base back on...as there's a small gap between metal and the glass, something like a 2-part rapid-setting clear resin/adhesive applied to the inside rim of the metal base should do the trick...or whatever your preference is, mab. And don't forget those 3 washers!
 Just make DOUBLY sure of the positioning - church window to same, and protruding metal 'locator' to glass 'pimple' - and all will be well...
  
 If ever you should have a problem with a base - eg (not that it _would_ happen, I'm sure!) : the base comes unstuck, and then gets damaged prising it out of the adapter (aren't I a cheerful chappie?!) - have no fear, I've a couple of spare ones you could have.
  
 Hopefully, mab, this is all the info you'll need. So I shall wish you all the best with the project - it certainly is worth the (minimal) effort to reveal the beauty hidden within!
 Any problems/questions, just post or PM me...
  

  
 Cheers...and remember the 30-50hrs burn-in needed!!


----------



## mordy

Just wondering - what is the purpose of the metal covers for the tube?
  
 Does the C3m tube require a different voltage? Seems it is less expensive than the Cg3.


----------



## mab1376

c3m uses 20v heaters. c3g is typical 6.3v.
  
 I read somewhere that the purpose is to keep the heat in but I'm not certain, I would think its to shield from EMI as well.


----------



## hypnos1

mordy said:


> Just wondering - what is the purpose of the metal covers for the tube?
> 
> Does the C3m tube require a different voltage? Seems it is less expensive than the C3g.


 
  
  As mab1376 says - 20V. And apparently also an excellent tube, but not the frame grid and gold pins of the C3g. Gain also seems less, and pin-out is different...so, given these caveats, certainly would appear a good candidate for those with external power supplies - if the price is right.


----------



## hypnos1

gibosi said:


> From what I have read, "VT-231" is nothing more than an inventory number used by the US Navy during WWII. All you can really infer from this designation is they were produced in the 1940's in support of the war. Evidently, they are identical to 6SN7GTs made during the 1940's for civilian use.
> 
> My impression is the Sylvania VT-231 is prized by those who combine more than one 6SN7 together to counterbalance deficiencies in each to achieve a desired sonic signature. But as your C3gs are very linear, and likely have no significant deficiencies, I believe they require an output tube with more balance than the Sylvania. If you are still interested in trying old-stock 6SN7, I would suggest a pair of Raytheon VT-231. There are two versions, and the one with 2 free support posts and flat plates seems to be preferred over the other. Or a pair of Tung Sol "Mouse Ears." In my experience, both of these have pretty good balance.


 
  
 Thanks for the info, gibosi. You certainly do a good bit of reading on these subjects!
 I have to admit that I am being rather 'picky' in my appraisal of the Sylvanias...with tracks heavier on the electronics and without too much treble emphasis, they sound really exciting...so it could well be a case of swapping around to suit...it surely is asking too much to expect a tube to give _everything_...Possibly a _real_ CV181/ECC32 just might get even closer to perfection (for _my_ ears, anyway), but at their prices - if you can find them at all - they are a non-starter! So I think I shall keep with my CV181/6SN7 hybrid...for now, at least...


----------



## gibosi

hypnos1 said:


>


 
  
 An excellent tutorial! I am bookmarking this page to use when I finally get around to purchasing a pair.
  
 Cheers


----------



## hypnos1

gibosi said:


> An excellent tutorial! I am bookmarking this page to use when I finally get around to purchasing a pair.
> 
> Cheers


 
  
 Thanks, gibosi - took me a good while to put together, but hope I covered most elements and that it may prove useful to you in the future (and perhaps anyone else who may be tempted to tread this path).


----------



## mordy

Hi,
  
 As you all know, burn-in is a part of life using vacuum tubes. Found a free burn in recording that covers most bases. It is intended for headphones/ear buds, but sounds eminently suitable for tubes as well. The site seems to offer good advice as well.
  
 https://www.jlabaudio.com/index/burn-in


----------



## mab1376

hypnos1 said:


> Thanks, gibosi - took me a good while to put together, but hope I covered most elements and that it may prove useful to you in the future (and perhaps anyone else who may be tempted to tread this path).


 
  
 Thanks much for the tutorial, I'm loving these more and more with time.
  
 With my super sensitive T70's I heard a little bit of a background buzz, but with my HD650's its dead silent.
  
 I haven't tested with the T70's again after some burn in, hopefully its gone.
  
 Thanks again.
  
 Also those washers may connect the shield to the outside metal base for reduced hum: http://www.audiofaidate.org/uploaded/baldo95/C3g-C3m-info.pdf


----------



## hypnos1

mab1376 said:


> Thanks much for the tutorial, I'm loving these more and more with time.
> 
> With my super sensitive T70's I heard a little bit of a background buzz, but with my HD650's its dead silent.
> 
> ...


 
  
 My pleasure mab - glad to be of help. And am also glad you're finding that they are developing nicely...just wait 'til the 50 hour mark!
  
 I would suspect that buzz is more to do with the adapters, but whatever, I do hope it disappears completely...(or perhaps the C3gSs are showing up something in the power tubes? Time should tell...Me, I had only deathly silence in the background - 650s again - with just the slightest 'ssshhh' with the volume at max and no music playing. But that, even, all but disappeared when I changed from the 6N30P-DRs to the Psvanes).
  
 Interesting re the washers/gaskets...I removed the metal base in my permanent adaptation, and no hint of hum...but then again, there seem to be so many possible causes for hum!
  
 Enjoy those little (well, not _so_ little!) treasures...
  
 Cheers


----------



## gibosi

Received a pair of Ken-Rad VT-231 today. These are often costly so I have been waiting for a good deal to pop up on eBay. Even though these look rather different, they are the same tube and sound identical. I suspect many bidders were put-off by their mismatched appearance, which was to my benefit.  
  
 The black glass seems a tad bit taller and was manufactured in June, 1944, and the shorter, clear glass, January, 1945. From what I have read, GE took over the company sometime in 1945, and the later, GE/Ken-Rad tubes don't seem to get much love. You can tell the original Ken-Rad from the later GE/Ken-Rad by the orientation of the plates. The original Ken-Rad has "staggered" plates. That is, while the plates are parallel, they are mounted between the micas at an angle. You can see this quite easily from the top. The later GE/Ken-Rads also have parallel plates, but they are mounted parallel to the edges of the micas.
  
 This tube is considered to be the "Bass Champion" of the 6SN7s, and I can certainly attest to that. The mids are neutral with a bit of sweetness, and the highs are quite nice and extended, but not as smooth and airy as the Sylvanias. All in all, a very nice tube.
  

  
 "Staggered" plates


----------



## mordy

Hi,
  
 Was re-acquainting myself with the famed Mullard M8100/CV4010 tubes. Actually, they sound very nice with my 6SN7 RCA drivers. Took a picture and discovered the ephemeral mysterious blue light that sometimes appear with tubes:
  

 On this picture you can also the thin heater wire on top of the mica that separates this tube from the rest.
  
 Here is a fancier picture of the blue light phenomenon:
  





  
 For further study (and more confusion) about what this is see this link under Type 1:
  
 http://www.jacmusic.com/techcorner/ARTICLES/English-neu/blueglow/blueglow.htm
  
 Good night!
  
 Yep - I picked the right word:
 e·phem·er·al
 əˈfem(ə)rəl/
_adjective_
 adjective: *ephemeral*
*1*.
 lasting for a very short time.
  

synonyms:transitory, transient, fleeting, passing, short-lived, momentary, brief, short;


----------



## i luvmusic 2

Hey mordy those adapters looks nice.


----------



## mordy

Hi i luvmusic2,
  
 There are actually 2x2 adapters. Here is the first one that allows you to put an octal tube into the Little Dot MKIII.
 http://www.ebay.com/itm/221065459067?_trksid=p2055120.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT
  




  
 However, the decorative rings around the tube sockets do not allow these adapters to go inside the socket since the adapters are too wide to fit inside the ring. For this we need an extender or socket saver:
  




  
 This set fits inside the ring. http://www.ebay.com/itm/2PCS-9-PIN-vaccum-TUBE-SOCKET-SAVER-FOR-12AX7-12AU7-ECC82-ECC83-tube-audio-amps-/251350602537?pt=Vintage_Electronics_R2&hash=item3a85a9d329
  
 Spending around $35 incl shipping for these four adapters allows you to use any 6SN7 tube (and 6SL7) in your LD MKIII. These tubes outclass the 6N6P family of tubes and to boot are plentiful and very inexpensive.
  
 There is a lot of hype about the 6SN7 tubes, and certain types command very high prices. IMHO I would not bother with these but instead buy any garden variety Sylvania or RCA tube. Just plug them in and enjoy delicious, full bodied sound! In addition, these tubes are well built and are supposed to last a long time.
  
 Another added bonus I noticed is that my LD amp does not even break out in a sweat with these tubes and the amp is cool to the touch. It has to be added though that I am using another 6SN7 as driver with it's own power supply.  The tubes run hot, but the amp is not even warm.
  
 And then there is the ephemeral Blue Light......


----------



## TrollDragon

Here MIKELAP is a nice tube for the little hybrid amp. Thanks!


----------



## mordy

Hi TD,
  
 The light on the picture is a LED light and not the blue glow. The following quote is from a 1960's Sylvania publication:
  
 "Blue Glows are not tube detriments per se. They are, however, suspects in the eyes of many receiving tube users for lack of a full understanding of their origins. There are several types of Blue Glow which can be described as follows:
 Blue glow FLUORESCENCE (Photo 1)- this type of glow is usually violet in color and most noticeable around the inside surface of the glass bulb. It is most pronounced on power tubes and is the product of electron bombardment of the glass taking place within the tube. It generally has no adverse affect upon receiver performance, and in fact, tubes displaying this phenomenon are particularly good with respect to gas content."
  








  
 Quote: "Hey, you'd be blue too if you smacked your head off a piece of glass a few billion times thicker than you while traveling at the speed of light."


----------



## TrollDragon

Hey mordy!
  
 I was just showing MIKELAP the 6BQ7A he sent to me in use with the hybrid amp, the LED under the lamp is actually white but appears blue in the camera.
  
  
 This is the Blue Glow that I like from Mecury Vapour Rectifiers.


----------



## mordy

Hi TD,
  
 "MERCURY VAPOR HAZE - is a blue-violet glow associated with those tube types which rely upon mercury vapor for proper operation. In such cases, the blue glow should be evident indicating proper operation."
  
 To be specific, the Blue Glow is not the same as the mercury vapor haze; the colors and origin are different.
  





To compare:




  
 As you all know, an expired tube turns white:
  




  
  
 I guess that too much much tube rolling drive some people crazy.....


----------



## i luvmusic 2

Will i be Blue because i still don't have my Tubes and those adapter parts from snail mail inc.in Chinada.
 Thanks for those Links Mordy.I'am expecting 2 russian 6AS7,6H8C and  8 RCA 6SN7 (got theme from Eb auction)I hope i don't get that Blue feeling this weekend.


----------



## i luvmusic 2

trolldragon said:


> Here MIKELAP is a nice tube for the little hybrid amp. Thanks!


 
 What type of Opamp do you have in that amp? Pardon me for asking.


----------



## TrollDragon

i luvmusic 2 said:


> What type of Opamp do you have in that amp? Pardon me for asking.


It came with an NE5532, I have an LME49860 in it at the moment.


----------



## i luvmusic 2

trolldragon said:


> It came with an NE5532, I have an LME49860 in it at the moment.


 
 Thank You!


----------



## gibosi

Yesterday I received a Sylvania Gold Brand 5670 (2C51/396A) with gold pins. These tubes are typically $40 to $50 each, but I found this one (1950's with D-getter) for only $10.00. It's obviously used and a little ratty looking, but it allowed me the opportunity to try one for cheap. I spent a couple hours with it last night, so I can't say that I know it's sound well, but I can say that I like this better than the Bendix I got a few days ago. So unless something changes, this is now my favorite 2C51.
  
 While there is no basis in fact, sometimes I find myself thinking that big tubes have big bass and little tubes have little bass. Well, this little tube quickly dispels one of that notion! lol Great bass, great highs and Sylvania's signature smooth mid range make this little guy a winner. 
  

  
 Short and squat.


----------



## mordy

Which pinout does the 5670 tube use? 12AX7 or 6DJ8?


----------



## gibosi

mordy said:


> Which pinout does the 5670 tube use? 12AX7 or 6DJ8?


 
  
 Neither. It is different from both of these. I am using an adapter, 2C51 on top and 6DJ8 on the bottom. Or you could simply re-configure one of your 9-pin sockets:
  
 Pin
 1          heater
 2          cathode #1
 3          grid #1
 4          plate #1
 5          shield (connected to pin 8)
 6          plate #2
 7          grid #2
 8          cathode #2
 9          heater


----------



## gibosi

After rolling 6SN7 and ECC40 from the 1940's and 1950's, I am beginning to think that that period of time was truly the golden age of vacuum tubes in the West. Considering how much I like my 1961 Heerlen-made E80CC, I decided to try to find one from the 1950's. This tube was first introduced around 1952, so hoped to find one from the mid 1950's. Well, I managed to find and purchase one, and it arrived today. At the time I purchased it, I wasn't sure of the manufacture date. The vendor couldn't make out the entire production code, but did provide the first line, "WK3".  With a change code of "3", I figured it was pretty early, as my 1961 has a change code of "8". I am pleased to discover that this one was manufactured in February, 1955. And further, I was surprised to discover this tube was manufactured in Eindhoven. The full code is WK3 45B.
  
 I have the tube in my amp as I write this, and it sounds great. But then, recently, it seems almost every tube sounds great on first listen... time will tell.... 
  
 1961 on the left, 1955 on the right, with pinched waist (neck?) and D-getter


----------



## mordy

Hi G,
  
 If you don't mind, a table showing which tube pin on my breadboard goes to which number on the Vector adapters right and left would be much easier for me to understand. Remember this table?
  
  
 9 Pin socket                                 Left LD socket                    Right LD socket
  
 1 plate triode 1                                     5
 2 grid triode   1                                     1
 3 cathode triode 1                                 2
 4 heater                                                                                           3
 5 heater                                                                                           4
 6 plate triode 2                                                                                 5
 7 grid triode 2                                                                                   1
 8 cathode triode 2                                                                             2
9 Shield tied to pin 8 at the socket


----------



## gibosi

mordy said:


> If you don't mind, a table showing which tube pin on my breadboard goes to which number on the Vector adapters right and left would be much easier for me to understand. Remember this table?
> 
> 
> 9 Pin socket                                 Left LD socket                    Right LD socket
> ...


 
  
 Here you go... 
  
 2C51 / 396A / 5670 wiring guide for the LD
  
 9 Pin socket                                 Left LD socket                    Right LD socket
  
 1 heater                                                                                           3
 2 cathode triode   1                                2
 3 grid triode 1                                        1
 4 plate triode 1                                       5
 5 shield tied to pin 8 at the socket
 6 plate triode 2                                                                                 5
 7 grid triode 2                                                                                   1
 8 cathode triode 2                                                                             2
 9 heater                                                                                           4


----------



## Oskari

gibosi said:


> After rolling 6SN7 and ECC40 from the 1940's and 1950's, ...


 
  
 I really like these tube photo-essays of yours.


----------



## i luvmusic 2

I just received my russian 6AS7 and playing it with LD 1 for now  just incase i blow something up. it works but i'm worried about the  tube base it's wobbly (both tubes i don't know if these is normal for these type of tube)it looks SEXY.


----------



## mab1376

Loving these C3gS tubes!
  
 Finally got the shields removed thanks to Hypnos1's guide.


----------



## gibosi

oskari said:


> I really like these tube photo-essays of yours.


 
  
 It's good to know that someone actually reads this stuff. Thanks! 
  
 And continuing with E80CCs, I just came across a very interesting listing on eBay. A pair of 1957 Hamburg-made E80CCs. From one of the pictures, it is easy to read the production code: WK2 D7B. And again, the production code on my tube is WK3 45B.
  
 Now this is very interesting...... The Hamburg tubes were manufactured two years, to the month, after my Eindhoven tube. But the change code on the Hamburg tube is "2" whereas the change code on my Eindhoven tube is "3". And so I wondered... why are the later Hamburg tubes an iteration behind my Eindhoven tube? My first thought was that it just took time for the latest changes to roll out from Holland. But on second thought, 2 years seems too long. Perhaps what this actually suggests is that by the middle 1950's the decision had already been made to cease the manufacture of this tube in Hamburg and consolidate all production in Holland, and eventually Heerlen. And therefore, it made good business sense to avoid spending the funds necessary to upgrade the Hamburg assembly line. And perhaps these 1957 tubes were among the very last to be made in Hamburg. 
  
 Of course, I do not know, but sometimes it is fun to speculate about things that happened many years ago....


----------



## gibosi

mab1376 said:


> Loving these C3gS tubes!
> 
> Finally got the shields removed thanks to Hypnos1's guide.


 
  
 These look great! What kind of glue did you use to reattach the metal bases?


----------



## hypnos1

i luvmusic 2 said:


> I just received my russian 6AS7 and playing it with LD 1 for now  just incase i blow something up. it works but i'm worried about the  tube base it's wobbly (both tubes i don't know if these is normal for these type of tube)it looks SEXY.


 
  
 Hey, I luv.
  
 WELL DONE for trying the 6AS7 - hope nothing goes..._bang?..._I sure do like the look of those tubes. I wondered some time ago if they could be used in our LDs...let's hope artsi's concerns can be overcome by these VERY versatile machines...are there any early warning signs of resistors becoming unhappy...ANYONE?...
  
 But, of course, we are (all?) dying to know if TWO used as power tubes are going to be safe! Is this on your menu at all? - "you're a braver man than I, Gunga Din"!
  
 Keep up the good work...


----------



## hypnos1

mab1376 said:


> Loving these C3gS tubes!
> 
> Finally got the shields removed thanks to Hypnos1's guide.


 
  
 Hi mab.
  
 WELL DONE!  See what you can do?...DIY adapters next!!...
  
 You don't know how happy I am that you are loving these tubes - after all my build-up, I would have been mortified to hear I was deluding myself (and possibly leading CollectoR13 - and yourself -  "up the garden path"!). I can now sleep easy...
  
 BTW. I have noticed the 7N7 has an almost identical metal base, and it appears the reason is so it can be connected to ground in the socket, to help combat hum...interesting, no?
  
 Your LD is now looking good...not to mention sounding eh? Now all you need is a nice pair of "coke bottle" 6AS7Gs or 6080s behind them and...WOW...or is that BANG?! We must follow I luvmusic's progress _very_ carefully, methinks...
  
 Happy listening.


----------



## i luvmusic 2

hypnos1 said:


> Hey, I luv.
> 
> WELL DONE for trying the 6AS7 - hope nothing goes..._bang?..._I sure do like the look of those tubes. I wondered some time ago if they could be used in our LDs...let's hope artsi's concerns can be overcome by these VERY versatile machines...are there any early warning signs of resistors becoming unhappy...ANYONE?...
> 
> ...


 
 So far so good the LD get a little warmer  compared to using 6SN7 that is all i've been using it for few hours now(continuous).With LD 1 it sound really good with huge soundstage but i have to turned the Volume knob a little bit higher than my usual listening level   have not try with my LD MK III yet i'am really enjoying this with LD 1.are there any early warning signs of resistors becoming unhappy?My answer is i don't know what to look for so can't really answer that besides the amp gets a little warm nothing else unusual happening with my amp.IMO  each hour passing by it's sounding better and better.Using it as a power tubes yes i consider that option i'am curious how it will sound and besides doesn't it look SEXY.About the Resistor if i only know which one i need to replaced i might swap it with better one.


----------



## mordy

Hi I luvmusic 2,
  
 When you say that the tubes are wobbly, do you mean that the glass envelope is loose or that they don't seat firmly in the sockets? Did you notice if you need to turn up the volume substantially more than with other tubes?


----------



## mordy

Hi Gibosi,
  
 Many thanks for the wiring diagram using the Vectors!
  
 I remember from my 6AK5 days that the Sylvania Gold tube sounded exactly the same as the Jan tube without the gold pins. There was a big difference in price though.


----------



## TrollDragon

Early warning signs of resistors going bad is a distinct burning smell just before they let go.

You would have to take the bottom off the LD I+ and see if any of them on the board are too hot to touch. They can glow red for a while before they open, so a blister warning is advised.


----------



## i luvmusic 2

mordy said:


> Hi I luvmusic 2,
> 
> When you say that the tubes are wobbly, do you mean that the glass envelope is loose or that they don't seat firmly in the sockets? Did you notice if you need to turn up the volume substantially more than with other tubes?


 
 Hi Mordy,
     Yes the glass is loose/wobbly i can actually twist the base and it will moved a bit. luckily the glass doesn't moved up that's probably a bad thing isn't it.I need to moved the volume knob a little bit higher than my listening level from 9 o'clock to 10 o'clock.


----------



## i luvmusic 2

trolldragon said:


> Early warning signs of resistors going bad is a distinct burning smell just before they let go.
> 
> You would have to take the bottom off the LD I+ and see if any of them on the board are too hot to touch. They can glow red for a while before they open, so a blister warning is advised.


 
 THANK YOU TD!Remember i used my finger as a thermometer for my blue amp so i know how it will feel


----------



## i luvmusic 2

No burning smell or no discolouring Resistors or maybe not yet it's only been  running for 5 hours so maybe it's a good sign.

  


 No more Vector test sockets for LD 1.


----------



## i luvmusic 2

Hi Mordy,
    I'am using the 6AS7 tube on my LD 1 tomorrow i will try it with MK III so i will let you know how it works with that amp and see how far i need to turn the volume knob.I think you have MK III right?


----------



## mab1376

gibosi said:


> These look great! What kind of glue did you use to reattach the metal bases?


 
  
 Honestly didn't use any, just connected them into the adapter and it stays in there fine.


----------



## TrollDragon

i luvmusic 2 said:


> Hi Mordy,
> Yes the glass is loose/wobbly i can actually twist the base and it will moved a bit. luckily the glass doesn't moved up that's probably a bad thing isn't it.I need to moved the volume knob a little bit higher than my listening level from 9 o'clock to 10 o'clock.


 

 Nice work on the bottom of the LD I+!
  
  
 Wobbly tube base... This is from the Antique Radio Forums on how to fix the problem which a lot of them there use.
  
 Quote: http://antiqueradios.com/forums/viewtopic.php?p=1233870#p1233870 





> I work a 50/50 mixture of Elmer's Glue and water into the tube base. This works well! It dries in about a day, and the beauty is that is comes off with water, so if you have a bit of excess, it wipes off easily.
> It's also just about invisible after you do the job...
> 
> -Tom


----------



## TrollDragon

i luvmusic 2 said:


>


 
  
 Looking at the bottom of your LD I see the yellow wire seems to join the filament power on both sockets together.
 If I can get you to take the cover off of it's transformer and see if there is a label on it, that should tell us how much power the transformer provides for the heaters.
  
 Post a picture of the label on the transformer with the Chinese writing and Voltages if you would.
  
 Thanks!


----------



## gibosi

mordy said:


> Hi Gibosi,
> 
> Many thanks for the wiring diagram using the Vectors!
> 
> I remember from my 6AK5 days that the Sylvania Gold tube sounded exactly the same as the Jan tube without the gold pins. There was a big difference in price though.


 
  
 You are very welcome.
  
 I never had a Sylvania 6AK5 with gold pins, so I can't say how it compared to the JAN tube. But I have seen Sylvania Gold Brand 2C51/5670 mil-spec tubes both with and without gold pins, and I wouldn't be surprised if they were in fact the exact same tube. And further, I would guess that all of 1950's Sylvanias are very similar, if not identical. That said, since I found the gold pin version for only $10, I figure why not?


----------



## mordy

Hi I luvmusic 2,
  
 I bought two octal tubes that the glass moved inside the bakelite bottom. My friend the retired electronics engineer took a little crazyglue and applied it in two-three spots with a little brush that came with the glue (supermarket brand).
  
 So far it is holding fine and no problems, and the repair took a minute.


----------



## hypnos1

mab1376 said:


> Honestly didn't use any, just connected them into the adapter and it stays in there fine.


 
  
 Hi mab....WARNING!... yes, they will work fine like that but (sorry if I'm stating the obvious) the problem could be if ever you decide to lift the tube out - without trying to remove the base from the adapter - and then replace it. You would need to be EXTREMELY careful with the positioning - I found that the tube can sit in the base quite snugly IN ANY POSITION! You would have to mark clearly on the side of the tube the mid-point "pimple" position, and ensure it aligns _perfectly_ with the indent in the base, rather than relying only on "church window" to "church window"...
 Better safe than sorry!...
  
 Cheers


----------



## mab1376

hypnos1 said:


> Hi mab....WARNING!... yes, they will work fine like that but (sorry if I'm stating the obvious) the problem could be if ever you decide to lift the tube out - without trying to remove the base from the adapter - and then replace it. You would need to be EXTREMELY careful with the positioning - I found that the tube can sit in the base quite snugly IN ANY POSITION! You would have to mark clearly on the side of the tube the mid-point "pimple" position, and ensure it aligns _perfectly_ with the indent in the base, rather than relying only on "church window" to "church window"...
> Better safe than sorry!...
> 
> Cheers


 
  
 Yes I lined up the "church window" with the proper hole seemed pretty straight forward. Also i'm aware the evacuation port is extremely sensitive and could cause the tube to lose its vacuum if cracked.
  
 I'll probably use some sort of glue for the base in the future when i feel ambitious and deoxit the pins.
  
 any suggestions? super glue, gorilla glue, hot glue, caulk?


----------



## hypnos1

mab1376 said:


> Yes I lined up the "church window" with the proper hole seemed pretty straight forward. Also i'm aware the evacuation port is extremely sensitive and could cause the tube to lose its vacuum if cracked.
> 
> I'll probably use some sort of glue for the base in the future when i feel ambitious and deoxit the pins.
> 
> any suggestions? super glue, gorilla glue, hot glue, caulk?


 
  
 Glad you don't seem to be having any trouble regarding positioning, but I would still advise making that visible mark on the side of the tube at the "pimple" position, to be doubly safe...especially if you find it's not so easy to remove the base from the adapter without deforming it too much!
 Hopefully you shouldn't find any need for deoxit, with gold-plated pins...but who knows?
  
 I personally would go for a 2-part (resin/hardener - rapid cure) adhesive that you mix - in the UK : "Araldite" - which you can apply to the inside rim of the base; which is not too runny; and which you can apply fairly neatly with a very small implement. You don't want it leaking down to the pins - or the evacuation port for that matter (worst case scenario? : _it_ becomes stuck to its 'protector'; the rest of the attachment loosens; you pull/twist the tube and...CRACK!  In case you hadn't noticed already, I'm a natural-born pessimist! But at least it makes me _ultra_ careful...).
 I don't know what your version of Araldite is, but I'm sure you get the gist of my meaning...unless anyone else has other/better suggestions?...


----------



## Nic Rhodes

A  few drops of super glue is all you need.


----------



## hypnos1

nic rhodes said:


> A  few drops of super glue is all you need.


 

 Hi Nic.
  
 This might be a little tricky...1. There is a slight gap between the metal base sides and the tube, which really needs to be filled with something thicker than super glue.  2. The 3 gaskets between tube bottom and metal base will also create a slight gap, and thus also need something a bit thicker. Just my own observations...
  
 Edit.  ps  I personally have come _not_ to trust so-called "super-glue" in many different situations in the past!...


----------



## Nic Rhodes

If you need a filler then super glue is not what you need, and I am not a fan of it in general at all, however if you have a wobbly base on say an octal or similar then a few drops will set it hard and is the only place I would ever recommend it but it works well here.


----------



## gibosi

I received a BRIMAR 13D3 today. As the ECC40 and 6CG7/6FQ7, with a gain of 20, were designed as miniature all-glass replacements for the 6SN7, it appears that the 13D3, with a gain of 32, was designed as a miniature all-glass 9-pin replacement for the ECC32. For some reason, these tubes tend to be somewhat expensive on eBay, around $40 or so, even though I am not aware of any amp that uses them. Eventually my patience was rewarded and I was thrilled to grab this one for $10. 
  
 The pin-out of this tube is identical to the 12AX7, but it requires an external heater PS. In the 6DJ8 setting, disconnect pin 9 (shield) from pin 8, adjust the voltage to 12.6, and go. Or configure your socket to run 12AX7 in 6-volt mode (but be aware that it draws .6amps, hence the need for an external PS), and go.
  
 The BRIMAR date code is "4F2", where 4 equals week, F equals month, and 2 equals year, so the year of manufacture could be 1952, 1962 or even 1972. However, with a D-shaped getter, I don't think it is as late as 1972. On the other hand, I am not sure this tube was even available in 1952, so my best guess is 1962.
  
 Having just shoved it in my LD, I am pleased to report that it lights up, it's quiet and I hear music.


----------



## i luvmusic 2

trolldragon said:


> Nice work on the bottom of the LD I+!
> 
> 
> Wobbly tube base... This is from the Antique Radio Forums on how to fix the problem which a lot of them there use.


 
 THANK YOU!i will give that a try when i have time.
  


trolldragon said:


> Looking at the bottom of your LD I see the yellow wire seems to join the filament power on both sockets together.
> If I can get you to take the cover off of it's transformer and see if there is a label on it, that should tell us how much power the transformer provides for the heaters.
> 
> Post a picture of the label on the transformer with the Chinese writing and Voltages if you would.
> ...


 
 Sure i will as soon as i'm done with my other Stuff should have done  that when i had it open for soldering  but yeah i will open it again and see what i can screw around with it again.
  


mordy said:


> Hi I luvmusic 2,
> 
> I bought two octal tubes that the glass moved inside the bakelite bottom. My friend the retired electronics engineer took a little crazyglue and applied it in two-three spots with a little brush that came with the glue (supermarket brand).
> 
> So far it is holding fine and no problems, and the repair took a minute.


 
 Thank You!i will try that.


----------



## i luvmusic 2

OK so i tried the 6AS7 with the LD MK III i need to turned the volume knob upto 12o'clock way past my listening level which is 9 o'clock to 10 oclock IMO it's very good, smooth i can listen to it in a full volume and not getting fatigue(it's loud) .I Run the amp and 6AS7 for 6hours and their are no barbeque smell or fireworks so that is a good sign for me to continue using this tube but then again i have 8 RCA 6SN7 on the way i prefer the 6AS7 over those 6SN7  i have on hand.I don't have exotic/expensive 6SN7to compare it with all i have are those common variety ex. Marconi GTB, Rogers GTA ,PHILCO GTB, westinghouse GTA, PHILIPS GTB ,GE GTA some Russian 6SN7  and a (Superior Electronics Industries Montreal,CANADA and it's Made in JAPAN).


----------



## i luvmusic 2

mab1376 said:


> Loving these C3gS tubes!
> 
> Finally got the shields removed thanks to Hypnos1's guide.


 
 I wish i can make my set up clean looking like yours very nice.Me i asked if those Power tubes are the New TUNG-SOL?


----------



## mab1376

i luvmusic 2 said:


> I wish i can make my set up clean looking like yours very nice.Me i asked if those Power tubes are the New TUNG-SOL?


 
  
 Yes they are new production Tung-Sol 6SN7GTB


----------



## i luvmusic 2

mab1376 said:


> Yes they are new production Tung-Sol 6SN7GTB


 
 Thank You!


----------



## i luvmusic 2

I would like to make a Power Adapter for my MK III i will be using a external power supply(12V 15A and 12A regulator)these adapter will be use with 6SN7 and 6AS7 tubes and the wires are 2ft. long so i'am thinking of using 18awg wire instead of 22awg. would the 18awg  or 22awg wire at 2ft long is big enough to handle the 6AS7 current? Can someone please doubble check my connections below.Thank you!
  
 LD MK III (2X)              Adapter(6SN7/6AS7)  (2X)
 1 A                               2 A
 2 G                              1 G
 3 K                               3 K
 4 H
 5 H
 6 A                                5 A
 7 G                               4 G
 8 K                                6 K
 9


----------



## gibosi

i luvmusic 2 said:


> I would like to make a Power Adapter for my MK III i will be using a external power supply(12V 15A and 12A regulator)these adapter will be use with 6SN7 and 6AS7 tubes and the wires are 2ft. long so i'am thinking of using 18awg wire instead of 22awg. would the 18awg  or 22awg wire at 2ft long is big enough to handle the 6AS7 current? Can someone please doubble check my connections below.Thank you!
> 
> LD MK III (2X)              Adapter(6SN7/6AS7)  (2X)
> 1 A                               2 A
> ...


 
  
 The connections look good to me. As to the adequacy of 18awg or 22awg, someone else will have to weigh in.....


----------



## TrollDragon

According to the chart #18 will handle 16A. You could probably get away with a 20 or 22 AWG but if your power supply is fused at 12 or 15A, anything lower than 18 would glow red and burn before the fuse blew.

So I would use the 18AWG just incase you ever had a short it would pop the fuse in the power supply.

If the powersupplys fuse is replaceable, you could put an 6 or 8A in place of what is there and use lower gauge wire.

18 is not that bad to work with so go with it, safety first.

AWG wire chart.
 www.powerstream.com/Wire_Size.htm


----------



## kvtaco17

I should rewire mine with 750kcmil... I could use scrap from work LMAO


----------



## TrollDragon

kvtaco17 said:


> I should rewire mine with 750kcmil... I could use scrap from work LMAO


I've stripped 4/0 chunks for the copper before... I'd love to have your 750 scraps. 

I just love wire you have to cut with a Milwaukee Sawzall.


----------



## kvtaco17

trolldragon said:


> I've stripped 4/0 chunks for the copper before... I'd love to have your 750 scraps.
> 
> 
> 
> ...


 

 4/0 is little cable in my line of work lol
  
 We normally use 350-1000... BUT the customer keeps the scrap... #thesearesaddays


----------



## Oskari

gibosi said:


> The BRIMAR date code is "4F2", where 4 equals week, F equals month, and 2 equals year, so the year of manufacture could be 1952, 1962 or even 1972. However, with a D-shaped getter, I don't think it is as late as 1972. On the other hand, I am not sure this tube was even available in 1952, so my best guess is 1962.


 
  
 That was my initial thinking, too. Now I'm not sure. The label style is certainly too old for 1972, but is it too old also for 1962? I tried to find photos of matching tubes with additional military labels (unambiguous date codes!) but this proved difficult. With enough patience this could be done.
  
http://www.r-type.org/exhib/aaa0626.htm tells us that the type first appeared in a 1953 Brimar manual. I then found this:
  

http://www.ebay.co.uk/itm/Brimar-13D3-CV2212-KB-FD-black-plate-ECC802s-ECC82-wide-square-getter-pair-rare-/291075287902?orig_cvip=true
  
 The photos show what must be experimental CV2212s with 2F2 date codes – and HG military date codes. That's July 1952. This agrees nicely enough with June from 2F2. Also note that, like your tube, the tubes have no type codes that usually go together with date codes. They do have the Footscray [military] factory code FB. Otherwise I've only seen Rochester codes, earlier FD and later AD.
  
 In short, I don't know where and when your tube was made.


----------



## gibosi

oskari said:


> http://www.ebay.co.uk/itm/Brimar-13D3-CV2212-KB-FD-black-plate-ECC802s-ECC82-wide-square-getter-pair-rare-/291075287902?orig_cvip=true
> 
> The photos show what must be experimental CV2212s with 2F2 date codes – and HG military date codes. That's July 1952. This agrees nicely enough with June from 2F2. Also note that, like your tube, the tubes have no type codes that usually go together with date codes. They do have the Footscray [military] factory code FB. Otherwise I've only seen Rochester codes, earlier FD and later AD.


 
  
 Comparing my tube to those, as best I can tell from the photo, the construction appears to be identical. Also, I overlooked two more characters printed in red on the back of the tube: A 3.


----------



## Nic Rhodes

The valve was certainly around by 1953 but not released by 1951 so 1952 is a real possibility.


----------



## Oskari

nic rhodes said:


> The valve was certainly around by 1953 but not released by 1951 so 1952 is a real possibility.


 
  


gibosi said:


> Comparing my tube to those, as best I can tell from the photo, the construction appears to be identical. Also, I overlooked two more characters printed in red on the back of the tube: A 3.


 
  
 Looks like you might have a very early 13D3 there. (I don't know what the red characters purport to tell.)


----------



## i luvmusic 2

gibosi said:


> The connections look good to me. As to the adequacy of 18awg or 22awg, someone else will have to weigh in.....


 
 Thank You!
  


trolldragon said:


> According to the chart #18 will handle 16A. You could probably get away with a 20 or 22 AWG but if your power supply is fused at 12 or 15A, anything lower than 18 would glow red and burn before the fuse blew.
> 
> So I would use the 18AWG just incase you ever had a short it would pop the fuse in the power supply.
> 
> ...


 
 Thank You!


----------



## gibosi

nic rhodes said:


> The valve was certainly around by 1953 but not released by 1951 so 1952 is a real possibility.


 
  


oskari said:


> Looks like you might have a very early 13D3 there. (I don't know what the red characters purport to tell.)


 
  
 Thanks for your help guys! 
  
 So I will put in my notes that this tube was quite likely manufactured in 1952, factory unknown.
  
 I spent a couple hours with this tube yesterday evening and it reminds me of other Brimars I have heard, with a strong bass, warm mids and somewhat subdued highs, a pretty good match for my HD700s. And after a half hour or so, I stopped listening to the tube and began to listen to the music, a very nice tube. Recommended.


----------



## gibosi

Mordy,
  
 If you are still looking for headphones, some to consider:
  
  
 Beyer DT770 250ohm - $125 shipped (MFR-Used Restock Model).
  
 http://www.fullcompass.com/product/436749.html?utm_source=googleps&utm_medium=shopping&utm_campaign=googleps&gclid=CK2zsqWAyr0CFUoV7AodEHUAxQ
  
 Also...
  
 www.razordogaudio.com extended their warehouse sale until April 15th: 
 Items below are 22% off with PROMO CODE --- WAREHOUSE. 
 2. ALL AIAIAI products
 3. ALL KEF products
 4. ALL AKG consumer AND pro products
 5. ALL Harman Kardon
 6. ALL JBL inventory
 7. ALL FOSTEX
 8. ALL Beyerdynamic
  
 And
  
 25% off select headphones at Sonic Electronix including low end Grados (SR60s, 80s, 125s), some AKGs, Senn Momentum On Ears, 380 Pros, Westone UM1s, etc.
  
 Search using     Headphones040514   as your keyword,
 use 25HEAD for the Coupon Code


----------



## i luvmusic 2

These will be my new Power supply/adapter for LD 1 and MK III when it's done.I can't wait for that speed boat from Chinada delivering my parts if that speed boat is not here in 2 weeks i will probably butcher one of my Amp and put it inside these case or i will learn how to read schematics and buy parts so i can build an amp instead of just power supply/adapter that is why i leaved the faceplate blank and did not solder any wires so i can decide what should i do with it later.The top plate is recycled from a old electronics(free)The faceplate(free)The two sides Wood cutoff from lumber yard $4 (cheap person) plus sockets and screws $15 that's how much it cost me and labour free i enjoyed it.


----------



## Rossliew

mordy said:


> Hi i luvmusic2,
> 
> There are actually 2x2 adapters. Here is the first one that allows you to put an octal tube into the Little Dot MKIII.
> http://www.ebay.com/itm/221065459067?_trksid=p2055120.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT
> ...


 
 Hi, would these adaptors allow the use of 6AS7 tubes in the LD Mk III ?
  
 Sorry, a noob here with the LD and also tube rolling...appreciate your advice on the various types of tubes which I can use with the adaptors in your picture above (thanks for the link to eBay - will purchase them to try out)


----------



## i luvmusic 2

Using a 6AS7 on LD without external power supply might suck out the life of your LD.I'am no expert it's just my opinion...


----------



## Rossliew

Thanks for the advice! LOL thankfully I didn't go crazy and start buying all types of tubes...what about those unique tubes which Gibosi uses in his amps? Where can one find an adaptor to match them to the LD mk III?


----------



## i luvmusic 2

Picked up a pair of 6CG7 for $2(pair)didn't think it works because vendor said they are not tested.I just tried now(Driver tube) and they are working they sound better than my 6N6P-i driver tubes.


----------



## mordy

Hi Rossliew,,
  
  
 The 6AS7 tube draws 2.5A with an amplification factor of 2. It seems that it is possible that you could use this tube as a driver tube, but only with an external power supply since the LD MKIII cannot handle such high current with it's built in power supply. The socket adapter for octal tubes should work for the 6AS7 tube.
  
 I am not sure if anybody has used the 6AS7 as a power tube in the LD MKIII. This setup would require external power supplies for both tubes. Then it seems to be a question if the internal electronics match this tube - could be that the amp would be damaged.
  
 A low amplification factor means that you have to turn the volume up higher than what you normally do. I am running a 6BX7 octal tube as driver with an amplification factor of 10 (draws1.5 amps) without any problems.
  
 I cannot say that I understand well the relationship between all these factors. In the past I tried to use 6FQ7/6CG7 tubes as power tubes but that did not work well. However, using the adapters and 6SN7 tubes works beautifully, and they sound better than the 6N6P-IR tubes that were my previous best power tubes.


----------



## gibosi

rossliew said:


> Thanks for the advice! LOL thankfully I didn't go crazy and start buying all types of tubes...what about those unique tubes which Gibosi uses in his amps? Where can one find an adaptor to match them to the LD mk III?


 
  
 First, I am using these tubes as drivers. and not power tubes. In order to do so, I have an external breadboard 9-pin socket, Vector test sockets and an external power supply. Once that is set up, you can buy very specific adapters to run ECC40, 2C51 and 6SN7s. If you still want to do this, I suggest you search this forum looking for "Vector", "breadboard socket", "ECC40 adapter" and "2C51 adapter".
  
 I know... I should probably put all this in one place, but...........
  
 And if you take no extra steps to make it pretty, you will have something like this:


----------



## mordy

Or this:
  

  
 As you can see from sophisticated colorful spider web inspired set up, there are two breadboards connected for a quick change from octal/12AX7  to 6DJ8 pinout tubes. Please note the advanced Sears multitester for voltage readings ($10 on sale) and the switched off LED on the voltage regulator which cannot decide if it is 6.7 or 6.8V -make that 6.3V at the tube pins for this 1.5A tube.
  
 Thanks Gibosi for all the inspiration and cheerful advice.
  
 But folks, this works! Beautifully.....


----------



## i luvmusic 2

mordy said:


> Or this:
> 
> 
> 
> ...


 
 Hi mordy,
      Have you ever try stacking the 2 vector does it hum when you stack them on top of each other?I would like to know if you done that because my new adapter i'am planning to solder all the wires together for the adapter socket and separate all the Heater wires in that way i can just plug-in all the tubes that i need and turn them on one at a time via heater switch.Connetions would be 6 wires from LD driver sockets to 6SN7 socket 6AS7 socket 6DJ8 socket 12AU7 socket but all the heaters are in thier own power switch.They  would all be plug-in all together then just turn on the switch that you need.


----------



## mordy

Hi 2,
  
 I have thought of it, but I am afraid to try it because even though the heater wires can be switched off, it seems to me that the wiring from one Vector set up could interfere with a different wiring configuration with another Vector as far as the amp is concerned.
  
 For me it is not very difficult to pull out the Vectors from one breadboard and plug in another set from another breadboard. The heater wires are always connected to both bread boards, but I make sure that only one tube is plugged in. The other thing to remember is to check the voltage - I briefly ran a 6V tube on 8V because I forgot to check.
  
 As pointed out previously, the voltage at the tube pins seems to change depending on the tube, and that setting has to be checked as well when switching tubes.
  
 I am the first one to admit that I do not know much about electronics, and there may very well be a way to stack the Vectors without any problems, but I defer to others to try it.


----------



## Rossliew

Thanks, Mordy and Gibosi for the advice. Looking at the pictures above and my very limited understanding of electronics and wiring, I think I will stick to the 6SN7 adaptors and enjoy that for awhile. Unless either of you chaps can prep one of those breadboards and external PSU ready for plug and play use, then I will gladly pay for a set to try out myself


----------



## gibosi

rossliew said:


> Thanks, Mordy and Gibosi for the advice. Looking at the pictures above and my very limited understanding of electronics and wiring, I think I will stick to the 6SN7 adaptors and enjoy that for awhile. Unless either of you chaps can prep one of those breadboards and external PSU ready for plug and play use, then I will gladly pay for a set to try out myself


 
  
 Unfortunately, my setup is too messy to lend itself to a nice and neat system that is plug and play. That said, all the information you need is contained in this forum. And if you do decide to give it a try, all you need are these items and some wire:
  
 1) One 9-pin breadboard socket. Search eBay for "9-pin breadboard socket" and "9-pin experiment socket"
  
 I purchased this one:
  
 http://www.ebay.com/itm/9-pin-breadboard-prototype-tube-socket-for-DIY-experimenting-/161388726782?
  
 2) Two 7-pin Vector test sockets:
  
 http://www.radiodaze.com/product/15450.aspx
  
 And if Radiodaze is out of stock, you can make some test sockets using a 7-pin socket and some 16 gauge wire:
  
 https://www.youtube.com/watch?v=MxLckWT-fvg
  
 3) A step down voltage regulator. This allows you to roll 6SN7 and ECC40 at 6 volts as well as 12 volt tubes like E80CC and 13D3.
  
 I purchased this one:
  
 http://www.ebay.com/itm/LM2596-Digit-Display-4-40V-DC-DC-Converter-Module-Step-Down-Regulator-Voltmeter-/360685295663?pt=LH_DefaultDomain_0&hash=item53fa84d82f
  
 And this one can handle more current:
  
 http://www.ebay.com/itm/1pcs-DC-DC-Step-Down-Power-Module-4V-38V-to-1-25V-36V-5A-Voltmeter-Adjustable/351197902632?
  
 4) An AC to DC power supply. You might have one of these already, an extra laptop power supply. Make sure it is rated for at least 1.5A. And if you anticipate running 12.6V tubes, at least 15V.
  
 For example:
  
 http://www.ebay.com/itm/19V-3-42A-Laptop-Power-Supply-AC-Adapter-Charger-Cord-for-Acer-Toshiba-Gateway-/121387965243?
  
 ~~~~~~~~~~
  
 If you decide to give this a try, come back here once you have all the parts and we will walk you through the connections.
  
 Cheers
  
 Edit: Clarified AC to DC power supply requirement.
 Edit2: Updated AC to DC PS to accommodate 5687/7044
 Edit2: Updated links


----------



## Rossliew

Wow!! This is what I call a real committed and very helpful community! Many thanks, G, for the kind advice and offer. I shall find time to read up more on this thread and google to learn a bit more basics before i attempt anything. Don't want to blow the amp (or possible myself!) up in the process...


----------



## gibosi

rossliew said:


> Wow!! This is what I call a real committed and very helpful community! Many thanks, G, for the kind advice and offer. I shall find time to read up more on this thread and google to learn a bit more basics before i attempt anything. Don't want to blow the amp (or possible myself!) up in the process...


 
  
 You are very welcome. It is fun and very easy, and I believe you will be very pleased with how much better your LD sounds with double triodes.
  
 A good place to begin to follow our double triode journey starts with Audiofanboy's post on page 204. And you will see that our first steps were even cruder and more primitive than what you have seen here recently. lol 
  
 http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/3045#post_9830528


----------



## mordy

Hi Rossliew,
  
 On page 301 post #4507 there is a step-by-step pictorial guide how to build a breadboard adapter. It does not require any technical knowledge and is easy to do with the right parts.


----------



## i luvmusic 2

mordy said:


> Hi 2,
> 
> I have thought of it, but I am afraid to try it because even though the heater wires can be switched off, it seems to me that the wiring from one Vector set up could interfere with a different wiring configuration with another Vector as far as the amp is concerned.
> 
> ...


 
 Hi Mordy,
          Thanks for the Info and about pluging tubes   to the proper voltage regulator/socket is very important to remember which tube you have on the socket.I did plug-in 6SN7 to 12V thinking that that was the Marconi 12SN7 but it was the marconi 6SN7 so when i look at it told my self that tube is glowing really bright and i leaved it there untill  the sound started to distort then i unplug it when it cools down i checked that tube and it was 6SN7 luckily it did not burn to this day that tube  still working and from that i always double checked what tube i have and which plug it's in(6V or 12V Socket).


----------



## Rossliew

Thanks, Mordy and G for the links...need to read and absorb the info there!


----------



## Rossliew

Btw, anyone have pictures on how to change the jumpers from ef95 to ef92 on the LD Mk 3?


----------



## kvtaco17

Its in the user manual... If you don't have the one that came with your amp, it is available on the little dot site...

http://dl.dropboxusercontent.com/u/6037680/Little%20Dot%20MK%20III%20Reference%20Guide.pdf


----------



## hypnos1

mordy said:


> Hi Rossliew,,
> 
> 
> The 6AS7 tube draws 2.5A with an amplification factor of 2. It seems that it is possible that you could use this tube as a driver tube, but only with an external power supply since the LD MKIII cannot handle such high current with it's built in power supply. The socket adapter for octal tubes should work for the 6AS7 tube.
> ...


 
  
 Hi mordy.
  
 First off I heartily agree with you re 6SN7 tubes as powers...the more I listen to my Sylvania VT231s (with the C3GSs as drivers) the more I am liking them - they are _absurdly_ good for the money. They really are giving my MUCH more expensive Psvane CV181-T IIs a run for their money (and that's before I make my own silver wire adapters!).
  
 Secondly, just for interest's sake, I am awaiting a Tung Sol 7N7 - the loctal version of the 6SN7GT..._more_ adapter-making!! Looking forward to seeing how they compare to the Sylvanias...
  
 And thirdly - don't ask me why (perhaps iluvmusic's pioneering spirit with 6AS7s has lit a fuse in me!) - but I have just bought some very nice-looking RCA "coke bottle" 6AS7Gs...wait for it...to try as power tubes. I know, I know...I am putting it down to early onset dementia! Whatever, I am determined to at least see if it is a complete no-no.
 As for heater power, I am wondering if it is possible to have one tube fed by the LD, with the other fed externally...suppose a peek inside would show if each is fed separately or not...
 And I would need to take off the front panel and stick my finger inside to test for excessive heat...*NO, ONLY KIDDING!!* - the dementia isn't _that_ far advanced?? A thermometer - carefully positioned! - should do the trick.
  
 You _could_ try to dissuade me, mordy, but I am all fired up at the moment!...Still, I have probably a fortnight to reflect on my madness...This rolling game has become _too_ addictive, lol...


----------



## gibosi

hypnos1 said:


> First off I heartily agree with you re 6SN7 tubes as powers...the more I listen to my Sylvania VT231s (with the C3GSs as drivers) the more I am liking them - they are _absurdly_ good for the money. They really are giving my MUCH more expensive Psvane CV181-T IIs a run for their money (and that's before I make my own silver wire adapters!).
> 
> Secondly, just for interest's sake, I am awaiting a Tung Sol 7N7 - the loctal version of the 6SN7GT..._more_ adapter-making!! Looking forward to seeing how they compare to the Sylvanias...
> 
> ...


 
  
 Glad to hear that the Sylvania's are growing on you. And as you like the VT-231, you would probably like most of the Sylvanias, Even the often maligned GTBs are quite good. And it is very likely that the Tung Sol 7N7s on their way to you are also a Sylvania. To the best of my knowledge, only Sylvania and National Union made 7N7 and the vast majority of the ones I have seen are Sylvania-made. (The Sylvania have chrome tops and the NUs do not.)
  
 And I would be very leery about trying to run one 6AS7 off the internal Little Dot heater circuit and the other off an external power supply. It is quite likely (TrollDragon please weigh in here) that the two power tubes are wired separately and drawing that much current through just one side may well overload your wiring (smoke and flames?). But for sure, if you are willing to go to the trouble of feeding one separately, it would be simple matter to feed both off the same external power supply (tie the tubes' heaters together, pin 7 to pin 7 and pin 8 to pin 8) as long as your power supply and regulator have sufficient capacity, I am guessing more than 5amps to be safe.
  
 So by all means do this! But be careful.


----------



## kvtaco17

gibosi said:


> Glad to hear that the Sylvania's are growing on you. And as you like the VT-231, you would probably like most of the Sylvanias, Even the often maligned GTBs are quite good. And it is very likely that the Tung Sol 7N7s on their way to you are also a Sylvania. To the best of my knowledge, only Sylvania and National Union made 7N7 and the vast majority of the ones I have seen are Sylvania-made. (The Sylvania have chrome tops and the NUs do not.)
> 
> And I would be very leery about trying to run one 6AS7 off the internal Little Dot heater circuit and the other off an external power supply. It is quite likely (TrollDragon please weigh in here) that the two power tubes are wired separately and drawing that much current through just one side may well overload your wiring (smoke and flames?). But for sure, if you are willing to go to the trouble of feeding one separately, it would be simple matter to feed both off the same external power supply (tie the tubes' heaters together, pin 7 to pin 7 and pin 8 to pin 8) as long as your power supply and regulator have sufficient capacity, I am guessing more than 5amps to be safe.
> 
> So by all means do this! But be careful.


 

 16 awg will be plenty safe @ 5A
  
 http://assets.bluesea.com/files/resources/newsletter/images/DC_wire_selection_chartlg.jpg
  
 That's assuming you run both heaters off an external regulator in parallel


----------



## gibosi

This is a good recommendation to use with an external power supply. But what we don't know is the wire gauge Little Dot is using to to supply heater current to power tubes in his LD !V. The 6N30s draw only about .9amps each, so it is not at all clear that it would be safe to draw 2.5amps through that same wiring for a single 6AS7.....


----------



## mordy

Hi hypnos 1,
  
 Seems that everybody agrees that the the 6AS7 tubes draw more power than the LD can put out. These tubes draw 2.5A each, and the LD MKIII can put out max 1.5A/channel if I remember correctly, so external power supplies are a must.
  
 I don't know how to rig up the adapters for two separate power supplies with voltage regulators for power tubes, but if you can figure it out it is certainly an interesting and rewarding project. And don't forget the aesthetic aspect:
  
"Here is a picture showing the open design of the 6AS7 electrode architecture. This tube (and the 6080) is a real glower - a perfect show-off tube.​"
  




  
 So I am definitively encouraging you to try; just exercise caution. Who knows, maybe you will end up with a bargain MK9!
  




  
 Personally, I would like to try the 6AS7/6080 as a driver tube with the 6SN7 tubes for power tubes. Or maybe a 5A 6338 tube? My voltage regulator can handle 5A ......


----------



## Oskari

Heaters aside, perhaps a single 6AS7G could replace both power tubes. What do you think?


----------



## hypnos1

Many thanks to you all - gibosi; mordy;kvtaco17; oskari - it really is comforting to know so many good people are here to keep an eye on us keen amateurs, who otherwise could get into _so_ much trouble!
  
 Yes, the obvious safe course is to externally heat _both_ tubes - just in case. Thanks for the reassurance...
  
 Yes, these tubes (especially the "coke bottles") are real sexy. And the "cokes" seem to attract more pluses than the others - or is it all in the mind?...(Mind you, the real stars seem to be that shape...viz WE 421A; 5998...).
  
 A single 6AS7? With amplification of just 2, would that be sufficient?
  
 There are a lot of factors to ponder in this experiment...not forgetting artsi's concerns.
  
 Thanks again for all your encouragement, folks, and be assured I shall be as careful as possible. It's such a shame it will be a while yet before I can venture forth into the unknown, what with postal systems etc. Not to mention sorting external power supplies. Ah well, such is the nature of what we do, no?
  
 ps. So gibosi, it looks like my 7N7 will just be replicating my VT231? Those adapters will have to wait, methinks!!
  
 pps....mordy - the 6338 seems to attract interest, but were there other differences to accommodate also?
  
 Cheers folks.


----------



## Nic Rhodes

I love the idea of using 6SN7GT more (great tube) but remember the GTB can take twice the power of our lovely GT fron the 40s. I would be interest in knowing where you got Tung Sol 7N7s  re the 6AS7G, my favourite tube type for OTLs and I use it loads, however I would not be thinking to use it here. Just a bit too different, PSU issues sorted. The E182CC might make another intersting power tube also.......anyone tried a 3A/167M as a pre?


----------



## gibosi

hypnos1 said:


> A single 6AS7? With amplification of just 2, would that be sufficient?
> 
> ps. So gibosi, it looks like my 7N7 will just be replicating my VT231? Those adapters will have to wait, methinks!!


 
  
 I think a single 6AS7 could be used. but it is not at all clear what it would sound like. As the LD runs the double triodes in parallel, the resisters used to bias the tube are sized accordingly, and they may be too far out of spec for a single triode. But even so, I think it may well be worth trying.
  
 And actually, the 7N7 will be less like your VT231 and more like a chrome-top 6SN7GT or GTA. At the least, you should notice more bass.


----------



## gibosi

Recieved a Tungsam ECC40 the other day. Casual inspection suggests that it is perhaps mid-1950's, with the rather dirty, multi-hued getter splash and foil getter. But on closer inspection, I see the little tag "75" and according to the Tungsram tube codes, this suggests mid-1970's. So at this point, I do not know what to think....


----------



## gibosi

nic rhodes said:


> ......The E182CC might make another intersting power tube also.......anyone tried a 3A/167M as a pre?


 
  
 The E182CC looks very interesting, unfortunately, is has a different pin-out than either the 6DJ8 or the 12AU7. It is closer to the 12AU7, but the heater center tap is on pin 8, instead of 9. It draws 640amps in the 6v mode and .320amps in the 12v mode
  
 http://tdsl.duncanamps.com/dcigna/tubes/sheets/amperex/7119-1g.gif
  
 For those of us using breadboard sockets, we would need to reconfigure three connections and use an external PS to use this as driver. And to use as a power tube, it would require a special adapter.
  
 And the 3A/167M is a single 6v loctal triode and would therefore require two custom adapters to be used as a driver, similar to the C3G. It draws .45amps, which is the same as the 6AH6 pentodes many of us used to run.
  
 http://www.retrovox.com.au/3A167M.pdf
  
 Two very interesting tubes, but both would require some work to use with our LDs.....


----------



## Nic Rhodes

gibosi said:


> Two very interesting tubes, but both would require some work to use with our LDs.....


 
  
 Nothing that hasn't been done before  and certainly the E182CC is a very friendly tube to the LDs. Some great Mullard box plates out there in good numbers


----------



## mordy

Then we have the synergy of running certain combinations of tubes together. My choice of investigating synergy is based on which tubes sounded good as drivers, and what I have that is a pair. Or, based on a sign I saw in a shoe store Midwest many years ago: A 7 and 71/2 shoe was labeled as a "near pair".
  
 Been running two RCA 6SN7 (Hoffman rebrand and RCA from the mid fifties) with mysterious dark blue glow and top mounted heater wires with a GE 6BX7 as driver. Time for a change. Found to my surprise two mid 50's identical Sylvania chrome tops with the same date in my 6SN7 box. (They were bought separately). Since it is a pair they got to play the power tube role. Then I took my 6SN7 Japanese Channel Master MatsuHiToTen and plugged it in as the driver tube. Checked the voltage - needed a little less than the 6BX7, but the LED readout reads 6.5V to get 6.3V at the tube pins.
  
 First impression: You got to wait. About 20 minutes before the tubes are up to speed. Then: Beautiful sound - sounds best without any adjustments in bass and treble. The bass is very powerful and the highs are sizzling. Very wide soundstage. All is well, nothing bothers me. The BX set up sounds different with more heft; this one is a little lighter, but everything sounds just right.
  
 Amazing how you cannot go wrong with 6SN7 tubes.....


----------



## MIKELAP

rossliew said:


> Btw, anyone have pictures on how to change the jumpers from ef95 to ef92 on the LD Mk 3?


 
     On the first picture you see 3 pins (arrows) on the right side its the EF95 JUMPER SETTING so you would use the 2 pins on the right and if you want to use EF92 you use the 2 pins to the left and you do the same thing for the other channel. On the 2 nd picture the jumper is on the EF95 setting these peep holes are under the Littledot remember to put jumpers the same way on both channels


----------



## i luvmusic 2

Regarding power supply i'am using a old desktop PS IMO it have more than enough current to roll  tubes (12V-15A) and i'm currently using a 12A voltage regulator.
 TD here is the picture of LD 1 transformer.I just butchered mine i can't wait for that speed boat from Chinada.The wire size from LD 1 are 22AWG i don't know about the MK III yet i'am about to find out soon.I'am replacing the transformer wires to 18awg the headphone socket are 18awg and the Pot is 22awg.


----------



## hypnos1

nic rhodes said:


> I love the idea of using 6SN7GT more (great tube) but remember the GTB can take twice the power of our lovely GT fron the 40s. I would be interest in knowing where you got Tung Sol 7N7s  re the 6AS7G, my favourite tube type for OTLs and I use it loads, however I would not be thinking to use it here. Just a bit too different, PSU issues sorted. The E182CC might make another intersting power tube also.......anyone tried a 3A/167M as a pre?


 
  
 Nic. Got the 7N7s off fleabay - one had just part of "Tung Sol" on it, the other no discernible markings but looking identical. Both chrome top short-bottles...so Sylvanias, according to gibosi...
  
 Am hoping against hope the 6AS7G is not _too_ different - and that the MKIV SE can continue its magical versatility...what a feat _that_ would be - the Klondike revisited perhaps?! (I do actually feel like I'm in the grip of goldrush fever lol!).
  


gibosi said:


> I think a single 6AS7 could be used. but it is not at all clear what it would sound like. As the LD runs the double triodes in parallel, the resisters used to bias the tube are sized accordingly, and they may be too far out of spec for a single triode. But even so, I think it may well be worth trying.
> 
> And actually, the 7N7 will be less like your VT231 and more like a chrome-top 6SN7GT or GTA. At the least, you should notice more bass.


 
  
 So,g, the 7N7 look to be Sylvania short-bottle chrome-tops. I believe you've said the short-bottles have a more detailed bass than the talls. Well that would suit me fine, because the VT231s - in my setup anyway - are giving me _plenty_ of bass, and I would prefer a little less weight and a bit more detail. I am sure it's that bass, plus the greater mids, that are giving me a little less "air" compared to my Psvanes (and the 6N30P-DRs). So perhaps I have _not_ wasted my money after all...thanks once more


----------



## TrollDragon

i luvmusic 2 said:


>


 
 Excellent ILM2, thanks for the pics!
  
 Unfortunately there is no current ratings on any of the outputs.
  
 Label reads as follows:
 Power Transformer - 15VA
 Import: 120V Black Red 120V Black Red
 Export: 100V Brown Brown 15V*2 Blue Black Blue
              3.2V*2 Green Black Green / Ground Green (The one on the top I assume)
  
 There is no current ratings on the individual winding and there is no way to figure it out from just the 15VA rating.
 If there was a model number on the transformer and one had access to the national Chi-Nee transformer database, it could be figured out.
  
 Since it is only 15VA there is NOT a lot of current to go around.
 The more info we have on these Little Dots the better we can understand the limitations.
  
 Thanks Again for the Pics!


----------



## Rossliew

mikelap said:


> On the first picture you see 3 pins (arrows) on the right side its the EF95 JUMPER SETTING so you would use the 2 pins on the right and if you want to use EF92 you use the 2 pins to the left and you do the same thing for the other channel. On the 2 nd picture the jumper is on the EF95 setting these peep holes are under the Littledot remember to put jumpers the same way on both channels


 
  
 Crystal clear now!! Thanks very much, M!


----------



## TrollDragon

Not picking on you gibosi, your posts just quoted nicely. 
	

	
	
		
		

		
		
	


	




 
  
 Quote:


gibosi said:


> And I would be very leery about trying to run one 6AS7 off the internal Little Dot heater circuit and the other off an external power supply. It is quite likely (TrollDragon please weigh in here) that the two power tubes are wired separately and drawing that much current through just one side may well overload your wiring (smoke and flames?). But for sure, if you are willing to go to the trouble of feeding one separately, it would be simple matter to feed both off the same external power supply (tie the tubes' heaters together, pin 7 to pin 7 and pin 8 to pin 8) as long as your power supply and regulator have sufficient capacity, I am guessing more than 5amps to be safe.


 
 Yes indeed 2.5A max split between the two power tubes, I would not advise using the LD to power 6AS7's. As gibosi says, if you are going to the trouble to externally feed one heater, might just as well feed both with a proper power supply, yes greater than 5 Amps as tubes can draw triple the current for a brief moment when starting from cold. 
  
  


gibosi said:


> I think a single 6AS7 could be used. but it is not at all clear what it would sound like. *As the LD runs the double triodes in parallel*, the resisters used to bias the tube are sized accordingly, and they may be too far out of spec for a single triode. But even so, I think it may well be worth trying.


 

 We can not run single triodes in the output stage as it is a Push-Pull, White Cathode Follower circuit.
  
 This is basically the output circuit give or take a few components (Borrowed from Tube Cad Journal)
 There is only the power tube from a single channel drawn here.

  
 Also an article written by Alex Cavalli from Cavalli Audio about optimizing a WCF circuit in an OTL amplifier. (Heavy Math)
 http://www.cavalliaudio.com/diy/docs/WCFOptimization.pdf


----------



## hypnos1

trolldragon said:


> Yes indeed 2.5A max split between the two power tubes, I would not advise using the LD to power 6AS7's. As gibosi says, if you are going to the trouble to externally feed one heater, might just as well feed both with a proper power supply, yes greater than 5 Amps as tubes can draw triple the current for a brief moment when starting from cold.
> 
> 
> 
> ...


 
  
 Thanks TD for your input re 6AS7 requirements...now just have to try and find a good (but not too expensive) hiA DC power supply here in the UK...
  
 Had a quick look at that article - gave me the shivers (flashback to school days!). But what I did manage to grasp was the difficulty in getting the plate resistance just right in this kind of circuit - shades of artsi's concerns. So it really is going to be a question of just where they pitched these parameters in the MKIV SE - hopefully such that they are "jack of all trades, master of none"!.
 Will certainly have to keep a _very_ close eye on those resistors...wish I knew _exactly_ where they would be located inside the unit, though...
  
 Interesting/slightly worrying times ahead, methinks!...


----------



## gibosi

hypnos1 said:


> Thanks TD for your input re 6AS7 requirements...now just have to try and find a good (but not too expensive) hiA DC power supply here in the UK...


 
  
 Search eBay for "laptop power supplies". These typically have plenty of capacity. For example:
  
 http://www.ebay.com/itm/AC-ADAPTER-POWER-SUPPLY-HP-PA-1900-18H2-P-N-463554-002-laptop-Charger-AMD-CPU-/400691844773?pt=Laptop_Adapters_Chargers&hash=item5d4b1856a5
  
 This is listed as 65W (18.5V/3.5A). Divide the wattage by 6.3V and you get a bit more than 10A, so more than enough. And I would expect that you could find something similar at a local computer supply store there in UK.


----------



## i luvmusic 2

It's too bad it's not enough info on that LD 1 Transformer.


----------



## gibosi

Received a Brimar 6SN7GT today. Managed to pick it up for $5. Apparently the vendor didn't realize what he had and the picture quality was quite poor, so I was the only one who bid on it. 
  

  
 This appears to be the first version, according the 6SN7GT Identification thread, apparently the same as the STC/Brimar 6SN7GTY / CV1988, as it has the "small anode plate extensions" extending vertically above the top mica.
  

  
 I have only just now shoved it into the LD, and I am happy to say that it lights up, it's quiet, and I hear music, A very good beginning.


----------



## gibosi

i luvmusic 2 said:


> It's too bad it's not enough info on that LD 1 Transformer.


 
  
 Even so, I think we can continue to assume that the LD 1+ can supply at most a total of one 1 amp shared between the two driver tubes. And to be safe, if we are going to use the internal heater circuitry, we should probably not exceed .450A per tube.


----------



## i luvmusic 2

I think i may have burn my VOLUME POT when i was unsoldering it from the PCB but i need to reconnect it to be sure it  still working but if i need to replace it do i need one of those so called high end and am i gonna gain something from those?


----------



## i luvmusic 2

gibosi said:


> Even so, I think we can continue to assume that the LD 1+ can supply at most a total of one 1 amp shared between the two driver tubes. And to be safe, if we are going to use the internal heater circuitry, we should probably not exceed .450A per tube.


 
 As long as we use External Power Supply we should be fine i think.I have used 6AS7 and the LD 1 get a little warmer than usual that is all so IMO it is safe to use 6AS7 i did run mine for 6 hours straight to see how long the LD 1 can handle the 6AS7 and my amp still functioning properly.It depends on how comfortable you are using 6AS7.LD 1 can handle that tube no doubt in my mind.


----------



## hypnos1

gibosi said:


> Search eBay for "laptop power supplies". These typically have plenty of capacity. For example:
> 
> http://www.ebay.com/itm/AC-ADAPTER-POWER-SUPPLY-HP-PA-1900-18H2-P-N-463554-002-laptop-Charger-AMD-CPU-/400691844773?pt=Laptop_Adapters_Chargers&hash=item5d4b1856a5
> 
> This is listed as 65W (18.5V/3.5A). Divide the wattage by 6.3V and you get a bit more than 10A, so more than enough. And I would expect that you could find something similar at a local computer supply store there in UK.


 

 Thanks gibosi...but that means a voltage regulator as well - was hoping to find something "all-in" (6V approx.) to keep things neat...you know I like things 'neat and tidy!'
  
 Cheers.


----------



## gibosi

i luvmusic 2 said:


> I think i may have burn my VOLUME POT when i was unsoldering it from the PCB but i need to reconnect it to be sure it  still working but if i need to replace it do i need one of those so called high end and am i gonna gain something from those?


 
  
 You are going to mount it on a new case I think? If it isn't too expensive, why not? And at the least, this is the perfect opportunity to get one with a larger knob. I have always felt that the LD 1+'s knob is too small and too slippery to allow very fine adjustments.


----------



## hypnos1

Hey there mikelap...how are things with the Woo? Am sure I'm not the only one eager to hear how it compares to the LD!
  
 Hope you can give us the low-down sometime soon...


----------



## i luvmusic 2

gibosi said:


> You are going to mount it on a new case I think? If it isn't too expensive, why not? And at the least, this is the perfect opportunity to get one with a larger knob. I have always felt that the LD 1+'s knob is too small and too slippery to allow very fine adjustments.


 
 Yes G i will be mounting it in a new Chassis but if that pot is still working i will still use it with a big KNOB i have the knob recycled from an old amp i don't know why i keep on using recycled materials am i going GREEN nah i'm just being CHEAP.


----------



## gibosi

hypnos1 said:


> Thanks gibosi...but that means a voltage regulator as well - was hoping to find something "all-in" (6V approx.) to keep things neat...you know I like things 'neat and tidy!'


 
  
 Well I am one of the best when it comes to easy and ugly. lol


----------



## gibosi

i luvmusic 2 said:


> As long as we use External Power Supply we should be fine i think.I have used 6AS7 and the LD 1 get a little warmer than usual that is all so IMO it is safe to use 6AS7 i did run mine for 6 hours straight to see how long the LD 1 can handle the 6AS7 and my amp still functioning properly.It depends on how comfortable you are using 6AS7.LD 1 can handle that tube no doubt in my mind.


 
  
 This is great news! We are all indebted to you for going out on a limb and trying these tubes as drivers. Thanks!


----------



## i luvmusic 2

hypnos1 said:


> Thanks gibosi...but that means a voltage regulator as well - was hoping to find something "all-in" (6V approx.) to keep things neat...you know I like things 'neat and tidy!'
> 
> Cheers.


 
 I don't know in your area if you can go to your local recycling yard(City owned yard not privately owned) and asked for Desktop Power supply it should be FREE of charged because they will distroy them anyway so you should be able to get them for FREE.What i did is went to my Town recycling yard and asked for old computer then they asked me why i need a junk computer and i told them i just need the power supply for my electronic project and they let me in and told me take as much as i want so i grabed 2 PS unfortunately 1 it does not work so now i got 12V-15A Power Supply for free and i  used a 12A voltage regulator.


----------



## i luvmusic 2

USED 6AS7 as a driver for your LD at YOUR OWN RISK i'am not responsible for ANY DAMAGED occured using 6AS7.
	

	
	
		
		

		
			




 I used my LD 1 as a guinea pig for all of us so PLEASE use yours with your own risk.


----------



## hypnos1

i luvmusic 2 said:


> I don't know in your area if you can go to your local recycling yard(City owned yard not privately owned) and asked for Desktop Power supply it should be FREE of charged because they will distroy them anyway so you should be able to get them for FREE.What i did is went to my Town recycling yard and asked for old computer then they asked me why i need a junk computer and i told them i just need the power supply for my electronic project and they let me in and told me take as much as i want so i grabed 2 PS unfortunately 1 it does not work so now i got 12V-15A Power Supply for free and i  used a 12A voltage regulator.


 
  
 Geez, man...I don't know about "going green"...more like canary yellow...'cheep cheep' - sorry for the pun!
 Got to admire your resourcefulness. Well done...good idea...but we're back to that regulator!
  
 Glad to hear you've had no problems with the 6AS7 as driver...wish I could feel 100% safe with them as powers, though...time will tell (don't know how long resistors can take punishment before throwing in the towel!).
  
 Keep up the good work...


----------



## i luvmusic 2

hypnos1 said:


> Geez, man...I don't know about "going green"...more like canary yellow...'cheep cheep' - sorry for the pun!
> Got to admire your resourcefulness. Well done...good idea...but we're back to that regulator!
> 
> Glad to hear you've had no problems with the 6AS7 as driver...wish I could feel 100% safe with them as powers, though...time will tell (don't know how long resistors can take punishment before throwing in the towel!).
> ...


 
 For power i would not push my luck on that with my experienced for driver it makes the LD a bit warmer than usual(i don't know much when it comes to Electronics or Electrical) i'am just imagining 2 6AS7 pushing or pulling that current from LD maybe the LD would not stand the heat that long maybe.But i'am willing to try it for a short period of time.


----------



## hypnos1

i luvmusic 2 said:


> For power i would not push my luck on that with my experienced for driver it makes the LD a bit warmer than usual(i don't know much when it comes to Electronics or Electrical) i'am just imagining 2 6AS7 pushing or pulling that current from LD maybe the LD would not stand the heat that long maybe.But i'am willing to try it for a short period of time.


 
  
 For sure ilm2, we're gonna have to be _extremely_ careful, lol!
  
 Ah well, time for bed...


----------



## mordy

Folks, the word is not cheap (or cheep), but FRUGAL. I'll bet you have a friend with an old outdated laptop who can give you the old power supply ....
  
 I discovered that the power supply I am using comes from an old label printer. 50W and 8A at 6.3V. Another source for a power supply would be an old credit card machine or an old scanner etc etc.


----------



## mordy

More plug-and-play fun:
  
 Went to my box of 6SL7 tubes. Found a near pair of two Sylvania 6SL7GTW from the 50's. One has a beige base and one a brown base. For reasons that are not fully explained this near pair was chosen to do the duty of power tubes.
 Then I picked a tall National Union 6SL7 with tinted glass (late 40's early 50's ?) as the driver tube. Somehow I have the notion that the driver tube should be tall. After all, it is in charge. Had to adjust the voltage down a little; 6.39V reads 6.3V at the tube pins.
  
 FIrst impression: Plays louder than the 6SN7. Then, sweet and fleet presentation with excellent treble and good, not overwhelming bass. Very musical - and I thought that I did not like 6SL7 tubes.....Not the utmost detail, but a very cohesive and beautiful sound stage.
  
 This all 6SL7 lineup is quite nice....

  
  
 (image missing)
  
 If you think my set up is awkward, watch this giraffe drinking water from a fountain in the desert....


----------



## TrollDragon

hypnos1 said:


> Will certainly have to keep a _very_ close eye on those resistors...wish I knew _exactly_ where they would be located inside the unit, though...


 
 This is my MK IV board, the SE should be the same except for upgraded capacitors and jacks.

 The two resistors circled in red are the 150Ω cathode resistors that Artsi spoke of, these resistors are 1 Watt. The two White Square resistors on the right edge of the board are 5 Watt sized just for reference.
  
 If running the 6AS7's as power tubes with the 1W resistors draws too much current, the most that would likely happen is you would just burn out those two resistors. The heat / flame generated when these resistors burn would cause much stress to the two caps on either side. If it doesn't cause any trouble to the circuit board underneath as well.
  
 This is a 1/4 Watt resistor with too much power through it, the bigger the wattage the better the burn. 

  
*So What Do?*
  
 New resistors come with long legs, you could put 5 Watt or 10 Watt resistors in place of these 1 Watt's for a few dollars each. Bend the legs and the resistor would have to be mounted in the air a little as it would not fit in the other resistors space.
  
 Then the resistors would not burn out, the transformer would...


----------



## Rossliew

hi guys, would these tubes be rollable for the Mk III ?
  
 http://www.ebay.com/itm/3C22S-EF95-6F32-Tube-lamp-USSR-Lot-of-2-pcs-/131045114396?pt=LH_DefaultDomain_0&hash=item1e82e5c21c


----------



## Oskari

No!
  
 It's a rectifier, not even close to EF95. That substitution "information" is positively dumb.


----------



## Rossliew

Many thanks, Oskari! I searched around the net and couldn't find info to state whether it was a direct replacement or not. Thank goodness for this thread and you fine people


----------



## hypnos1

mordy said:


> Folks, the word is not cheap (or cheep), but FRUGAL. I'll bet you have a friend with an old outdated laptop who can give you the old power supply ....
> 
> I discovered that the power supply I am using comes from an old label printer. 50W and 8A at 6.3V. Another source for a power supply would be an old credit card machine or an old scanner etc etc.


 
  
 Yes indeed mordy, frugal is a MUCH nicer word....but "cheap" has an extra dimension - _naughty_ AND (possibly!) nice - when used amongst friends, that is!!
  
 And as in all probability - ref TDs doomsday scenario below! - that power supply will be in operation for a _very_ short while, I would be silly not to take the ch...oops, sorry...FRUGAL option, n'est-ce-pas? So on the hunt I shall go (IF my nerve holds out, that is! 
	

	
	
		
		

		
		
	


	




).
  


trolldragon said:


> This is my MK IV board, the SE should be the same except for upgraded capacitors and jacks.
> 
> The two resistors circled in red are the 150Ω cathode resistors that Artsi spoke of, these resistors are 1 Watt. The two White Square resistors on the right edge of the board are 5 Watt sized just for reference.
> 
> ...




  
 Many, many thanks TD for showing where I need to stick my finger...no, THERMOMETER!...so as to back off before things get too scary - or should it be DISASTROUS! And burning out the transformer is NOT an option...
  
 Excuse my ignorance, but where does _anode_ resistance come in, as opposed to _cathode_ resistance?...Would appreciate your enlightenment.


----------



## i luvmusic 2

trolldragon said:


> This is my MK IV board, the SE should be the same except for upgraded capacitors and jacks.
> 
> The two resistors circled in red are the 150Ω cathode resistors that Artsi spoke of, these resistors are 1 Watt. The two White Square resistors on the right edge of the board are 5 Watt sized just for reference.
> 
> ...




 Hi TD,
        If repalced those resistors with say 10W and used a external power supply would it be still put alot of stress on the transformer?


----------



## MIKELAP

rossliew said:


> Many thanks, Oskari! I searched around the net and couldn't find info to state whether it was a direct replacement or not. Thank goodness for this thread and you fine people


 
 Did you have a look at page 77 those are tubes that are compatible with the Littledot for the most part but some have to be modified like the 6AV6 tubes that you need to cut  pins 5 and 6 off and cover those up with electrical tape , or the 6AU6 tubes which need an adapter or a socket wire mod 2-7 which means you link pin holes 2 and 7 with a very small wire and insert in socket holes on Littledot and insert tubes after


----------



## Rossliew

Mikelap, let me check it out, thanks again. In any case, i bought a bunch of ef95 type tubes off ebay so I will be occupied for awhile. But am really, really itching to try the external power supply mod as advised by Gibosi above..


----------



## TrollDragon

hypnos1 said:


> Excuse my ignorance, but where does _anode_ resistance come in, as opposed to _cathode_ resistance?...Would appreciate your enlightenment.


 

 This page here can explain the various resistors and their purpose better than I can.
 The author was trying to play on the xxx for dummies foolishness of back in the day.
 http://www.diystompboxes.com/pedals/tubedummy.html
  


i luvmusic 2 said:


> Hi TD,
> If replaced those resistors with say 10W and used a external power supply would it be still put alot of stress on the transformer?


 

 Yes... The anode resistor, those power resistors and the transformer doesn't provide enough B+ voltage or current...
 Also I do not possess enough knowledge of tube theory or the math to calculate what you would have to change to get the LD board to run those tubes in a properly configured circuit.
  
 Here are some tube parameter explanations.
 http://www.allaboutcircuits.com/vol_3/chpt_13/8.html
  
 Here is a plenitude of tube books all in the public domain.
 http://www.tubebooks.org/technical_books_online.htm


----------



## i luvmusic 2

I need to stop screwing around with LD circuits because i'm making it sounding like crap i took apart the LD1 tried transfering it in a new  chassis after that it hum like crazy and as soon as i put it back in it's original case it's dead silent.I did ground the whole chassis and it did reduce the hum a bit bundled all the cables but that did not help at all it actually made it hum even more.enough for me for now i'am just going to enjoy them the way they are made and just roll tubes speaking of tubes just received my 8 RCA 6SN7 and i love them all they really are better than the first few sets of 6SN7 i have.
     Thank you TD for those Links!


----------



## TrollDragon

i luvmusic 2 said:


> I need to stop screwing around with LD circuits because i'm making it sounding like crap i took apart the LD1 tried transfering it in a new  chassis after that it hum like crazy and as soon as i put it back in it's original case it's dead silent.I did ground the whole chassis and it did reduce the hum a bit bundled all the cables but that did not help at all it actually made it hum even more.enough for me for now i'am just going to enjoy them the way they are made and just roll tubes speaking of tubes just received my 8 RCA 6SN7 and i love them all they really are better than the first few sets of 6SN7 i have.
> Thank you TD for those Links!


 

 Enjoy the Links and all the reading while listening to your new RCA's.


----------



## gibosi

I think I have found a possible successor to my LD 1+: the Cavalli Liquid Glass, a "Tube-Roller's Dream Amplifier." Like the LD 1+ it is hybrid and would allow me to roll almost all my double triodes.
  
 https://www.cavalliaudio.com/index.php?p=product_details&pId=1
  
 However, there are a few drawbacks...  I won't be able roll 8v and 25v tubes. Further, the amp uses pairs rather than singles, so tube rolling is more expensive. And finally, the price is $2,950, which is a bit more than I can handle unless I win big at the lottery or find a sugar mama. lol


----------



## TrollDragon

Yes gibosi

That is a very nice looking amp with great protection and auto biasing features. End game amplifier for sure with your HD700's until you get a taste of Audeze's...


----------



## TrollDragon

And like I said to MIKELAP with the Woo, its only money dude, you can't take it with you.


----------



## kvtaco17

gibosi said:


> I think I have found a possible successor to my LD 1+: the Cavalli Liquid Glass, a "Tube-Roller's Dream Amplifier." Like the LD 1+ it is hybrid and would allow me to roll almost all my double triodes.
> 
> https://www.cavalliaudio.com/index.php?p=product_details&pId=1
> 
> However, there are a few drawbacks...  I won't be able roll 8v and 25v tubes. Further, the amp uses pairs rather than singles, so tube rolling is more expensive. And finally, the price is $2,950, which is a bit more than I can handle unless I win big at the lottery or find a sugar mama. lol


 
 Well you could mod it for tubes with voltages greater then 6v lol


----------



## MIKELAP

gibosi said:


> I think I have found a possible successor to my LD 1+: the Cavalli Liquid Glass, a "Tube-Roller's Dream Amplifier." Like the LD 1+ it is hybrid and would allow me to roll almost all my double triodes.
> 
> https://www.cavalliaudio.com/index.php?p=product_details&pId=1
> 
> However, there are a few drawbacks...  I won't be able roll 8v and 25v tubes. Further, the amp uses pairs rather than singles, so tube rolling is more expensive. And finally, the price is $2,950, which is a bit more than I can handle unless I win big at the lottery or find a sugar mama. lol


 
 Is Liquid fire similar $2000.00 canuck dollars thats about $1700.00 U.S      http://www.canuckaudiomart.com/details/649105006-cavalli_audio_liquid_fire/


----------



## MIKELAP

trolldragon said:


> And like I said to MIKELAP with the Woo, its only money dude, you can't take it with you.


 
 By the way thanks for your advise there TD               
 lol .


----------



## MIKELAP

trolldragon said:


> Yes gibosi
> 
> That is a very nice looking amp with great protection and auto biasing features. End game amplifier for sure with your HD700's until you get a taste of Audeze's...


----------



## i luvmusic 2

Here is my new adapter(6SN7,6DJ8,12A..EF 91..and for 6SN7 Power Adapter for MK III)  for LD 1 and MK III it's made out of recycled materials(Because i'am CHEAP or FRUGAL as per Mordy).The LD 1 is inside the adapter Chassis and i finally resolved the hum problem i had when i was working on LD 1(Disconnected ground inside LD 1 Chassis)I can't decide about the finish Polish the aluminum or paint the whole case or leaved it the way it is so you can see all the ugly pencil marked and scratches on the surface.


----------



## gibosi

mikelap said:


> Is Liquid fire similar $2000.00 canuck dollars thats about $1700.00 U.S      http://www.canuckaudiomart.com/details/649105006-cavalli_audio_liquid_fire/


 
  
 The Liquid Fire is quite different in that it does not encourage tube rolling. There are 6 screws on the bottom that have to be removed to again access to the tubes, 6DJ8s I believe. Apparently the amp is no longer available from Cavalli, as it does not appear on their website.
  
 While the Liquid Glass looks to be a great amp, it has a solid state output like my LD 1+, so it isn't really what I want. And unfortunately, I was very disappointed to learn that the Crack is designed for headphones 200 ohms and higher. My HD700s are 150 ohms so back to square one....


----------



## gibosi

i luvmusic 2 said:


> Here is my new adapter(6SN7,6DJ8,12A..EF 91..and for 6SN7 Power Adapter for MK III)  for LD 1 and MK III


 
  
 Wow!


----------



## MIKELAP

gibosi said:


> The Liquid Fire is quite different in that it does not encourage tube rolling. There are 6 screws on the bottom that have to be removed to again access to the tubes, 6DJ8s I believe. Apparently the amp is no longer available from Cavalli, as it does not appear on their website.
> 
> While the Liquid Glass looks to be a great amp, it has a solid state output like my LD 1+, so it isn't really what I want. And unfortunately, I was very disappointed to learn that the Crack is designed for headphones 200 ohms and higher. My HD700s are 150 ohms so back to square one....


 
 At least on the Woo i can use my 6DJ8 varietys good thing i had bought pairs .


----------



## mordy

Hi I luvmusic 2,
  
 Congrats or your new adapter box!. My only suggestion is to label all the sockets (and switches) so that you don't make mistakes when inserting different tubes or switching voltages etc. Something tells me that you may want to wait with the finish until you have finalized the design (provision for 2c51/5670 tubes?).


----------



## i luvmusic 2

mordy said:


> Hi I luvmusic 2,
> 
> Congrats or your new adapter box!. My only suggestion is to label all the sockets (and switches) so that you don't make mistakes when inserting different tubes or switching voltages etc. Something tells me that you may want to wait with the finish until you have finalized the design (provision for 2c51/5670 tubes?).


 
   Thanks for your suggestion!In the back of the box there is a TERMINAL BLOCK  where i can only connect one adapter at once so it's less mistake connecting adapter it's semilar to switching PCB or VECTOR only one at a time and all the heater wires are all isolated no switches just Dc jack and they have a 12V Dc jack adapter i made that the plug is bigger than the one for 6V dc jack.I was going to put switch in between the adapters instead of pluging 6 wires in the terminal block but i'am worried about noise/hum issue by putting switch in between and i tried leaving the vector on the amp and plugin one adapter on top of vector adapter and it's a bit noisy specialy if i moved my hand across the amp.
    The 6SN7 power tubes are really nice and it make the MK III run cooler it doesn't even get warm it feels like it's off it's cold and i'am worried that the MK III might get frozen (no just kidding)


----------



## mordy

I also noticed that the 6SN7 tubes used as power tubes don't even make the LD MKIII break out in a sweat - runs really cool, which I think is good.
  
 In the never ending quest for audio truth I have being trying out different combinations of octal tubes. I am trying to the answer the question:
 Do power tubes matter?
  
 The answer is yes. I decided to use some of the poorest sounding 6SN7 tubes I have (based on using them as driver tubes). Put in a near pair of two GE 1950's tubes, and used a good performing Tung Sol 6SN7GTA as driver. This TS tube is a real midget with a short glass envelope. Although I prefer a tall tube as driver I decided not to discriminate and give the little guy a chance.
  
 The main problem with the sound was the bass. Flabby, muddy, without good control of the low frequencies and a dull almost lifeless presentation.
  
 So my conclusion, which is also based on comparing the 6N6P family tubes as power tubes, is that the main difference with different power tubes is the control of the bass and the quickness and slam of the presentation. I am not stating this as an absolute, but at this point I am inclined to think that this may be correct IMHO. (If you think otherwise, I am interested to know.)
  
 Could not stand the GEs, so I popped in a near pair of '53 and '55 RCA 6SN7 tubes. This TS/RCA combo is OK with the only complaint too much sizzle in the treble. Maybe it will go away after using the tubes for a while; you'll never know with these used bargain tubes. With a NOS tube you can count on it changing for the better after burn in, but here I just don't know.
  
 Well, I found out. LOL; even after extended playing the treble was too sharp. Put in the tried and true RCA heater wire on top of mica tubes, and popped in the Japanese Channel Master as driver, and all is well again.


----------



## Rossliew

Anyone with suggestions of tubes to try with the Mk III for pairing with a HD800?


----------



## gibosi

rossliew said:


> Anyone with suggestions of tubes to try with the Mk III for pairing with a HD800?


 
  
 Everyone's ears are different. What one person likes another doesn't, even with the same headphones and amp....
  
 I don't have the HD800s, but I have been able to spend a little time with them. In my opinion, the very clinical and analytical nature of the HD800s pairs very well with a rather warm tube with strong bass. So I would suggest a pair of RCA 6DT6. Set your LD to use EF92 tubes, and they are plug and play. And fortunately, they are normally inexpensive, so if they aren't to your taste, you haven't lost much.


----------



## Rossliew

gibosi said:


> Everyone's ears are different. What one person likes another doesn't, even with the same headphones and amp....
> 
> I don't have the HD800s, but I have been able to spend a little time with them. In my opinion, the very clinical and analytical nature of the HD800s pairs very well with a rather warm tube with strong bass. So I would suggest a pair of RCA 6DT6. Set your LD to use EF92 tubes, and they are plug and play. And fortunately, they are normally inexpensive, so if they aren't to your taste, you haven't lost much.


 
 Thanks G and I agree with you on the differences in listening preferences. I shall look out for the 6DT6 tubes. Would Mullards be a good pairing as well?


----------



## gibosi

rossliew said:


> Thanks G and I agree with you on the differences in listening preferences. I shall look out for the 6DT6 tubes. Would Mullards be a good pairing as well?


 
  
 Generally speaking, the best Mullards have warm bass and lower mids and smooth and liquid upper mids and highs. So yes, if you like a warm sound signature, you might like these as well. Of the "traditional" Little Dot tubes, the Mullard EF92 are a classic example.


----------



## MIKELAP

hypnos1 said:


> Hey there mikelap...how are things with the Woo? Am sure I'm not the only one eager to hear how it compares to the LD!
> 
> Hope you can give us the low-down sometime soon...


 
 Tonight i listen to the Littledot it had been a while,  i used  a 6SL7 octal tube with octal adapter and Electro Harmonix 6H30PI gold pin power tubes and my first impression is that the Woo has a fuller warmer sound also more bass using a pair of Russian 6N13S/ 6AS7 as  power tubes .   Littledot seems thinner sounding  and thats with the Senns HD800. but Littledot is no slouch it does the job.  One other thing if i would of used  the Russian 6n6pir power tubes they  usually sound warmer  than the Electro Harmonix


----------



## gibosi

mikelap said:


> Tonight i listen to the Littledot it had been a while,  i used  a 6SL7 octal tube with octal adapter and Electro Harmonix 6H30PI gold pin power tubes and my first impression is that the Woo has a fuller warmer sound also more bass using a pair of Russian 6N13S/ 6AS7 as  power tubes .   Littledot seems thinner sounding  and thats with the Senns HD800. but Littledot is no slouch it does the job.  One other thing if i would of used  the Russian 6n6pir power tubes they  usually sound warmer  than the Electro Harmonix


 
  
 As I believe your Woo uses 6DJ8, I would like to know how the same 6DJ8 compares in your LD.


----------



## Rossliew

mikelap said:


> Tonight i listen to the Littledot it had been a while,  i used  a 6SL7 octal tube with octal adapter and Electro Harmonix 6H30PI gold pin power tubes and my first impression is that the Woo has a fuller warmer sound also more bass using a pair of Russian 6N13S/ 6AS7 as  power tubes .   Littledot seems thinner sounding  and thats with the Senns HD800. but Littledot is no slouch it does the job.  One other thing if i would of used  the Russian 6n6pir power tubes they  usually sound warmer  than the Electro Harmonix


 
  
 Mike, which Woo amp did you use to pair with the HD800? And that LD tube adaptor looks killer! Is there a link somewhere as to how I could DIY that for my Mk III ? thanks


----------



## Rossliew

gibosi said:


> Generally speaking, the best Mullards have warm bass and lower mids and smooth and liquid upper mids and highs. So yes, if you like a warm sound signature, you might like these as well. Of the "traditional" Little Dot tubes, the Mullard EF92 are a classic example.


 
 OK, noted with thanks. Shall try to experiment changing jumpers first before i search for EF92 tubes..


----------



## MIKELAP

rossliew said:


> Mike, which Woo amp did you use to pair with the HD800? And that LD tube adaptor looks killer! Is there a link somewhere as to how I could DIY that for my Mk III ? thanks


 
 i am using the Woo audio 2 with the HD 800.  This is the schematics and the parts you need  Qty. 1 chassis mount octal sockets , Qty. 2 chassis mount 7pin sockets ,  after you will need 1m.m. dia. stock to make the 14 pins and cut them to right lenght , 2 pin straihgtners that go on top of 7 pin socket and hot glued with pins together  like picture  .Next i think i used 20 or 22 gauge stranded wire .youll need shrink wrap  to put over wires  when soldering is done and chassis you will need to align sockets in Littledot and  jb weld sockets in the copper pipes and put the shrink wrap with glue inside  over sockets  so the sockets dont come out when you pull adapter out  . picture at bottom is the pipes you will need doesnt have to be exactly like that but i recommend you get sockets first bring them to the store and check the fit because you will have to modify pipe to fit the octal socket meaning opening up hole so octal socket fits in (dremel).you will need a tester to check your connections because when looking at configuration of the  pins  pin 7 is actually pin 1 when you flip it over to  connect to Littledot so study the schematic well because i made that mistake.  .                                                                                                                                                                                                                                                                                                                                                                       Regarding chassis it is made of 3 parts theres the part for the 2- 7pin sockets but theres also a reducer sleeve in the part where octal goes so the pipe for 7 pin socket fits snuggly also i soldered a piece of pipe  to the octal pipe for the left channel . So it looks nice but its alot of work  At best i think it took at least 5 hours to do this . you can also make a 6DJ8 adapter theres less grinding for this one the socket for the 9 pin tube fits right in the pipe .Also gibosi has a nice breadboard setup if you do not want to solder and keep in simple  if you have any questions let me know ill be happy to help you out .


----------



## hypnos1

mikelap said:


> Tonight i listen to the Littledot it had been a while,  i used  a 6SL7 octal tube with octal adapter and Electro Harmonix 6H30PI gold pin power tubes and my first impression is that the Woo has a fuller warmer sound also more bass using a pair of Russian 6N13S/ 6AS7 as  power tubes .   Littledot seems thinner sounding  and thats with the Senns HD800. but Littledot is no slouch it does the job.  One other thing if i would of used  the Russian 6n6pir power tubes they  usually sound warmer  than the Electro Harmonix


 
  
 Hi mikelap. Bet you're loving your woo, you lucky thing!
  
 I wonder how the LD would compare, with either my C3gSs or 6SN7s as drivers, and some good 6SN7s (or Shuguang CV181-z/Psvane CV181-T II) as powers?..I have a hunch the competition would be _much_ hotter!!
  
 Whatever, it's nice to know you haven't forsaken us all here...


----------



## MIKELAP

hypnos1 said:


> Hi mikelap. Bet you're loving your woo, you lucky thing!
> 
> I wonder how the LD would compare, with either my C3gSs or 6SN7s as drivers, and some good 6SN7s (or Shuguang CV181-z/Psvane CV181-T II) as powers?..I have a hunch the competition would be _much_ hotter!!
> 
> Whatever, it's nice to know you haven't forsaken us all here...


 
 The Littledot is a very nice sounding amp with the 6DJ8 or 6SL7 and its probably better even with the 6sn7 you guys are using and compared to the Woo the Littledot is  no slouch with the tubes we are using and its not a night and day difference its hard to put in words let me put it like this if youd sample both amps you wouldnt say OH MY GOD what a difference not with our tubes anyway and these olden ears by the way .                                                                                                                                                                                                                                                                                                                                                                           


gibosi said:


> As I believe your Woo uses 6DJ8, I would like to know how the same 6DJ8 compares in your LD.


 
 And regarding the use of the 6DJ8 in the Littledot and the Woo its pretty similar but the power tubes of the Woo  and rectifiers affects sound from what ive read and noticed . So i guess even if components are not of same quality the sound is ¨similar¨  , but will Littledot last as long as a Woo ?


----------



## gibosi

In my mailbox today I discovered a pair of C3g having just arrived in the US after running away from the UK. The story they are telling is that back in the UK, they were feeling rather unloved and neglected as their owner was spending all his time with the more hoity-toity *C3gs*, and so they decided to make their escape. And I am very glad they did! lol 
  
 I fired them up, and yes, everything that *hypnos1* has said about them is true. These are top-tier tubes. I've only had a little time with them, but the first thing I notice is that they are very clear and very musical, and similar to *mab1376*, I notice they are bit more forward (going only by memory) than my reference Sylvanias. This is in no way a negative. One might say that the Sylvania 6NS7W and the Siemens C3g are both top tier, but the C3g is just a "lighter shade of gray."
  
 I have them plugged into my Vectors, primarily because this will make it much easier to compare them to double triodes. Of course, this essentially negates all the silver *hypnos1* put into them. (And I think I can hear his groans all the way from Britain! lol) But it also creates a more even playing field for comparison purposes. Both the double triodes and the C3g are routed through the Vectors, which handicaps both equally, and if anything, the C3g with a shorter wire run to the LD, is perhaps handicapped less.
  
 Even though I knew that the C3g is a Loctal, I was still shocked to see just how big these tubes are. As you can see these are not little.


----------



## gibosi

How about the 6336 as a power tube? This is essentially two 6AS7s in one bottle, and thus requires *5 amps* of heater current. 
  
 http://www.r-type.org/exhib/aai0287.htm


----------



## hypnos1

gibosi said:


> In my mailbox today I discovered a pair of C3g having just arrived in the US after running away from the UK. The story they are telling is that back in the UK, they were feeling rather unloved and neglected as their owner was spending all his time with the more hoity-toity *C3gs*, and so they decided to make their escape. And I am very glad they did! lol
> 
> I fired them up, and yes, everything that *hypnos1* has said about them is true. These are top-tier tubes. I've only had a little time with them, but the first thing I notice is that they are very clear and very musical, and similar to *mab1376*, I notice they are bit more forward (going only by memory) than my reference Sylvanias. This is in no way a negative. One might say that the Sylvania 6NS7W and the Siemens C3g are both top tier, but the C3g is just a "lighter shade of gray."
> 
> ...


 
  
 Yo gibosi..._lovely_ (surprisingly large!) tubes...glad you like 'em...
  
 As for the forward nature, I have found that it is all down to the power stage...as I mentioned some while back - and now corroborated by mordy - the old-established wisdom re the power tubes not having a great impact on the final result is just not correct.
 In my case, the differences between 6N30P-DR; Psvane CV181-T II and Sylvania VT231 are not just minimal - especially between the last two...the VT231 is _much_ more forward, quite a different sound. At first I thought it may just be a question of strange synergy between my C3gSs and the followers, but mordy's findings with different 6SN7s has confirmed my suspicions...power tubes are _just_ as important as the drivers in our LDs. So more research is definitely needed in this area...perhaps tubes a little less risky than those (6AS7) I shall be trying in the weeks to come! The LD journey is obviously not over yet!!
  


gibosi said:


> How about the 6336 as a power tube? This is essentially two 6AS7s in one bottle, and thus requires *5 amps* of heater current.
> 
> http://www.r-type.org/exhib/aai0287.htm


 
  
 This would indeed be another great milestone for us, gibosi,...*IF* it were possible! Everything looks stacked against us with these types - the fateful day is a while off just yet, as I await all the necessary ingredients for the Chinese fireworks!!! (A prayer or two might not go amiss!..)
  
 Cheers.


----------



## MIKELAP

hypnos1 said:


> Yo gibosi..._lovely_ (surprisingly large!) tubes...glad you like 'em...
> 
> As for the forward nature, I have found that it is all down to the power stage...as I mentioned some while back - and now corroborated by mordy - the old-established wisdom re the power tubes not having a great impact on the final result is just not correct.
> In my case, the differences between 6N30P-DR; Psvane CV181-T II and Sylvania VT231 are not just minimal - especially between the last two...the VT231 is _much_ more forward, quite a different sound. At first I thought it may just be a question of strange synergy between my C3gSs and the followers, but mordy's findings with different 6SN7s has confirmed my suspicions...power tubes are _just_ as important as the drivers in our LDs. So more research is definitely needed in this area...perhaps tubes a little less risky than those (6AS7) I shall be trying in the weeks to come! The LD journey is obviously not over yet!!
> ...


 
                                                                                                                                                                                                                                                                                                                                                                
  
 Might need more than that!


----------



## hypnos1

mikelap said:


> Might need more than that!


 
  
 Reckon you could just be right, mikelap...been nice knowing y'all!!


----------



## mab1376

hypnos1 said:


> Reckon you could just be right, mikelap...been nice knowing y'all!!


 
  
 Has anyone tried 12AX7 as power tubes yet?
  
 http://www.ebay.com/itm/Tube-socket-converter-adapter-12ax7-ecc83-to-russian-6n2p-/161183516184?pt=Vintage_Electronics_R2&hash=item2587494618
  
 should be safe
  
 "The 'E' in the European designation classifies this as having a 6.3 volt heater" at 300 mA
- http://en.wikipedia.org/wiki/12AX7
  
 I think someone suspected these of being identical to re-issue telefunkens:
  
 http://www.ebay.com/itm/2x-NEW-JJ-Tesla-12AX7-ECC83-ECC83S-Vacuum-Tube-Matched-Pair-TESTED-/290608597897?pt=Vintage_Electronics_R2&hash=item43a99f4b89
  
 I still want to try some VT231's i've still only be using re-issue Tung Sol 6SN7.


----------



## gibosi

hypnos1 said:


> As for the forward nature, I have found that it is all down to the power stage...as I mentioned some while back - and now corroborated by mordy - the old-established wisdom re the power tubes not having a great impact on the final result is just not correct.
> In my case, the differences between 6N30P-DR; Psvane CV181-T II and Sylvania VT231 are not just minimal - especially between the last two...the VT231 is _much_ more forward, quite a different sound. At first I thought it may just be a question of strange synergy between my C3gSs and the followers, but mordy's findings with different 6SN7s has confirmed my suspicions...power tubes are _just_ as important as the drivers in our LDs. So more research is definitely needed in this area...perhaps tubes a little less risky than those (6AS7) I shall be trying in the weeks to come! The LD journey is obviously not over yet!!


 
  
 While this is true for all-tube amps, where driver tubes actually "drive" the output tubes, in the LD 1+, the driver tubes don't really "drive" anything. And in fact, if one wanted, the tube stage can be bypassed by a straight wire, and the amp would still work perfectly fine, minus the tube "flavor". With no interaction between the tube and op amp stages, the op amp simply amplifies the audio signal after it has been "flavored" by the tube. And therefore, I am quite confident in saying that the C3g is inherently a bit more forward than my reference Sylvania, all else being equal.
  
 But of course, as those of you who have power tubes know, finding and selecting driver and power tubes with just the right synergy is half the fun. And I do hope to be able to eventually find and purchase an OTL amp with 6AS7 type power tubes so that I can double my fun too.


----------



## gibosi

mab1376 said:


> Has anyone tried 12AX7 as power tubes yet?
> 
> http://www.ebay.com/itm/Tube-socket-converter-adapter-12ax7-ecc83-to-russian-6n2p-/161183516184?pt=Vintage_Electronics_R2&hash=item2587494618
> 
> ...


 
  
 I have never seen seen the 12A-7 tubes used as power tubes, only as drivers. Being small signal tubes, I don't think they can provide enough "power", so to speak. But of course, should you want to try, they may well work. However, as the LD is configured for 6 volt power tubes, you will need to find an adapter to enable these 12 volt tubes to run on 6 volts.


----------



## Oskari

Europe calling! They are 6V tubes!
  
 As well. When properly connected as such.


----------



## Nic Rhodes

amps have used them as outputs [paralled]  but not my choice!


----------



## gibosi

oskari said:


> Europe calling! They are 6V tubes!
> 
> As well. When properly connected as such.


 
  
 Yes, I know. 
  
 However, the LD power-tube sockets are wired for 6N30P-type tubes, and I am quite sure most folks are not up to disassembling their LD and rewiring pins 4, 5 and 9 on the circuit board to run 12A-7 type tubes in 6-volt mode. And therefore, I suggested adapters such as these to reconfigure the heaters and allow one to plug 12A-7-type tubes into a 6 volt socket configured for 6N30P (6GC6/6DJ8).
  
 http://www.ebay.com/itm/Two-adapters-for-12AU7-ECC82-6CG7-TUBES-amplifier-/260716251584?pt=Vintage_Electronics_R2&hash=item3cb3e649c0


----------



## Oskari

gibosi said:


> Yes, I know.


 
  
 I know you do. (I'm just joking.)
  
 But the _E_ says that they _are_ 6V tubes... (I'm going to stop now.)


----------



## gibosi

oskari said:


> I know you do. (I'm just joking.)
> 
> But the _E_ says that they _are_ 6V tubes... (I'm going to stop now.)


 
  
 Oh, now I see what you mean!  
  
 ECC81 (12AT7), ECC82 (12AU7), ECC83 (12AX7).
  
 In the European system, the beginning "E" indicates 6V tubes. "F" indicates 12V tubes, but I don't know that I have ever seen a European tube beginning with "F"?


----------



## mordy

In the past I tried several different 12AX7 tubes as _drivers_ but was not very impressed. IMHO there is a correlation between how a driver tube sounds compared to the same tube used as a power tube. It seems to me that a tube that sounds good as a driver tube would sound good as a power tube as well, and a poor sounding driver tube would not sound good when used as a power tube.
  
 It also seems to me that the electric guitar crowd like the 12AX7 for their amps, which has caused the prices to go up, especially on the older German and British tubes.


----------



## gibosi

Again, I don't think the 12AX7 have enough power. But if someone wants to try a small signal tube, the 6DJ8 / ECC88 is plug and play. Like the 12AX7, I doubt it has enough power, but if someone wants to try, it would be easier and cheaper than buying a pair of adapters for the 12AX7.


----------



## gibosi

Siemens C3g and Sylvania (gold pin) GB 5670 (396A / 2C51)
  
 Did a quick AB to compare tonality. While I find the mid range on the C3g to be a tad bit more forward than the Sylvania 6SN7W, it is very nearly the same as the Sylvania 5670. With the C3g vocals have a tad bit more warmth in the upper bass / lower mid range while the 5670 is maybe a tad bit more lush, but they are very close. Again, this was just a quick AB, so can't say more at this time....


----------



## mordy

Hi G,
  
 Took up your challenge with the 6DJ8 family tubes as power tubes. Since I did not want to take a chance if anything untoward would happen, I picked some tubes from my stock that I don't use much; a near pair of 6BZ7 (GE and Sylvania) as power tubes, and a Russian 6N9C (6SL7 equivalent) as the driver.
  

  
 The 6BZ7 is a 6.3V tube and draws 0.4A, so an easy load in the LD MKIII and a very similar load to the 6SL7 tubes. Took a deep breath and turned on the heaters on the Russki driver, than powered up the LD amp, waited 30 seconds for warm-up, then pushed the speaker button in. Sound! Music; sounds quite good. Seem to to have adequate power in my system. Also tried my AT ATH-AD700  headphones; they play very loud. Need more time to analyze the sound, but this combo definitively works.
  
 Man, a new world of power tubes suddenly opened up! 6DJ8, 6BC8, 6BZ8, X155, 6BS8, 6BQ7 and the Russian 6N23P.
  
 Popped in a (real) 1974 pair of the Voskhod 6N23P - sounds very good. The headphones need less volume than usual. Stay tuned.....


----------



## Oskari

gibosi said:


> In the European system, the beginning "E" indicates 6V tubes. "F" indicates 12V tubes, but I don't know that I have ever seen a European tube beginning with "F"?


 
  
 I don't think many F types existed.
  

http://frank.yueksel.org/sheets/118/e/EL152.pdf


----------



## Nic Rhodes

http://www.stereophile.com/content/ear-v20-integrated-amplifier
  
 Shows a ecc83 amp, not my cup of tea but popular!


----------



## mab1376

mordy said:


> Hi G,
> 
> Took up your challenge with the 6DJ8 family tubes as power tubes. Since I did not want to take a chance if anything untoward would happen, I picked some tubes from my stock that I don't use much; a near pair of 6BZ7 (GE and Sylvania) as power tubes, and a Russian 6N9C (6SL7 equivalent) as the driver.
> 
> ...


 
  
 Are the 12AX7 and 6DJ8 the same pinout?
  
 It seems you didn't need any kind of adapter for this, would that be the same for the 12AX7?
  
 I want to try the new issue JJ tubes that are supposedly pretty good.


----------



## gibosi

mab1376 said:


> Are the 12AX7 and 6DJ8 the same pinout?
> 
> It seems you didn't need any kind of adapter for this, would that be the same for the 12AX7?
> 
> I want to try the new issue JJ tubes that are supposedly pretty good.


 
  
 No. As above, these are normally 12V tubes, and even though the triode elements have the same pin-out, the heaters are different. Unless you want to try to rig up an external heater power supply, the easiest way to use them as power tubes is to purchase these adapters, which reconfigures the heaters for 6V circuits.
  
 http://www.ebay.com/itm/Two-adapters-for-12AU7-ECC82-6CG7-TUBES-amplifier-/260716251584?pt=Vintage_Electronics_R2&hash=item3cb3e649c0


----------



## mordy

Have been listening to the 6N23P tubes (6DJ8 family) as power tubes with a GE 6BX7 as driver, which is an excellent tube. The treble and midrange are very good sounding, but the bass has a hollow quality to it when you crank up the volume, as if it is running out of steam. Maybe this is what Gibosi meant when he thought these tubes would not have enough power. Had the same impression with 6BZ7 tubes as power tubes.
  
 In any event, the 6DJ8 type tubes can compete with the 6N6P family as power tubes. In addition, they can be found very inexpensive as long as it doesn't say Amperex on them.


----------



## i luvmusic 2

I think buying a Balance and match tubes are just rip-off.


----------



## TrollDragon

i luvmusic 2 said:


> I think buying a Balance and match tubes are just rip-off.


Unless you have a balanced amp like the MK VIII where you want matched pairs on each side.


----------



## i luvmusic 2

trolldragon said:


> Unless you have a balanced amp like the MK VIII where you want matched pairs on each side.


 
 I'am using a RCA 6SN7 that according to the sellers measurement reading marked on the tubes are way out of balance and i can't tell any difference.


----------



## TrollDragon

And again with the LD which is NOT designed to run the octals propery, you wouldn't be able to tell since the tube is underpowered... :rolleyes:


----------



## i luvmusic 2

trolldragon said:


> And again with the LD which is NOT designed to run the octals propery, you wouldn't be able to tell since the tube is underpowered...


 
 Thanks good to know because some vendors are offering that service and it's not free.


----------



## TrollDragon

We don't need matched tubes for our amps... So it would not be worth buying them.


----------



## hypnos1

gibosi said:


> While this is true for all-tube amps, where driver tubes actually "drive" the output tubes, in the LD 1+, the driver tubes don't really "drive" anything. And in fact, if one wanted, the tube stage can be bypassed by a straight wire, and the amp would still work perfectly fine, minus the tube "flavor". With no interaction between the tube and op amp stages, the op amp simply amplifies the audio signal after it has been "flavored" by the tube. And therefore, I am quite confident in saying that the C3g is inherently a bit more forward than my reference Sylvania, all else being equal.
> 
> But of course, as those of you who have power tubes know, finding and selecting driver and power tubes with just the right synergy is half the fun. And I do hope to be able to eventually find and purchase an OTL amp with 6AS7 type power tubes so that I can double my fun too.


 
  
 Hi g.
 Yes indeed, having a neutral power stage - for comparisons at least - seems very useful for assessing different drivers...and interesting that you and mab find a forward signature for the C3g, which I only found with the Sylvania VT231.
  
 ALSO FOR ANYONE interested in different power tubes....
  
 On the subject of synergy - plus TDs reiteration of matched tubes not being necessary in our LDs - I have just completed my first adapter for the Tung Sol 7N7 as powers(Sylvania chrome-top), after having foolishly(?) assumed that being a loctal-version 6SN7 the pin-out would be the same!... and double SHOCK/SURPRISE/BEWILDERMENT...then *JOY*...
  
 Firstly, after resin getting where it shouldn't!, it actually _worked_...
  
 Secondly, even before adapter burn-in, I could not believe my ears...something that doesn't seem to have worked well for folks before now...with the 7N7 in the right channel and the Psvane in the left - absolute MAGIC! NOS American plus young(ish) Chinese? - NO WAY is what I was expecting...certainly not what (at the moment anyway) appears to be a very happy marriage of the best of the Psvane and that of the VT231...the spatial clarity of the former, with a bit more of the mids and bass of the Sylvania/Tung Sol.
 Obviously I need to see if this holds for my other test pieces, but at the moment I am somewhat gobsmacked...so perhaps experimentation with 'mix and match' of power tubes is in fact a possible option after all!! What is there to lose, I ask?
  
 So another step forward in the power tube saga - for me, anyway. Should be interesting to see what happens with the _two_ 7N7s...but that will have to wait a wee while, I'm afraid...those adapters are a bit of a pig to make - I defy _anyone_ to make one with a 22mm case!!...Of course, any sensible person just buys the ready-made 7N7 to 6SN7 adapters and piggy-backs onto the 6CG7 adapter...but TWO lots of degradation? - not for me!
  
 Anyway, time to come back down to Earth and get on with the chores...will check later to see if I was simply hallucinating after too much strong coffee


----------



## gibosi

hypnos1 said:


> So another step forward in the power tube saga - for me, anyway. Should be interesting to see what happens with the _two_ 7N7s...but that will have to wait a wee while, I'm afraid...those adapters are a bit of a pig to make - I defy _anyone_ to make one with a 22mm case!!...Of course, any sensible person just buys the ready-made 7N7 to 6SN7 adapters and piggy-backs onto the 6CG7 adapter...but TWO lots of degradation? - not for me!


 
  
 Actually, it is possible to do this with only one "lot of degradation".  
  
 7N7 to 6CG7 adapter:
  
 http://www.ebay.com/itm/two-Adapters-7N7-plug-adapters-6CG7-ECC88-tubes-amplifier-SUB-/250751485734?pt=Vintage_Electronics_R2&hash=item3a61f40726
  
 And for those of you who do not want to mess with loctals, the late 1940's to early 1950's small-bottle chrome-top Sylvania 6SN7GT and GTA sound very similar to the 7N7.


----------



## i luvmusic 2

how do you read the date on tubes?


----------



## hypnos1

gibosi said:


> Actually, it is possible to do this with only one "lot of degradation".
> 
> 7N7 to 6CG7 adapter:
> 
> ...


 
  
 Hi again gibosi.
  
 Just popped back to correct my previous post - said mordy, not mab - and found your post...certainly much better than two piggy-backed, but *$37* each PLUS postage?...OUCH!!...Will stick to my blood, sweat and tears!...
  
 Cheers.


----------



## gibosi

i luvmusic 2 said:


> how do you read the date on tubes?


 
  
 For the small-bottle chrome-top Sylvania 6SN7GT and GTA (and other Sylvania tubes):
  
 326 = 1953 week 26
  

  
 Top etch codes:
  
 D= April, 2 = 1952 (And R = Replacement - that is, not OEM issue)
  

  
 Edit: Added top etch codes and fixed typos


----------



## gibosi

hypnos1 said:


> Hi again gibosi.
> 
> Just popped back to correct my previous post - said mordy, not mab - and found your post...certainly much better than two piggy-backed, but *$37* each PLUS postage?...OUCH!!...Will stick to my blood, sweat and tears!...
> 
> Cheers.


 
  
 Actually, $37 for a pair plus $13 for shipping (to the States), so still not cheap.


----------



## i luvmusic 2

My tubes marking on the base are AL and on top of tubes F4B and F3B these are Sylvania Chrome top no number markings anywhere on or around  the tubes.So F=June 4=1954  and B=? is these right?


----------



## gibosi

i luvmusic 2 said:


> My tubes marking on the base are AL and on top of tubes F4B and F3B these are Sylvania Chrome top no number markings anywhere on or around  the tubes.


 
  
 F4B = June 1954 and F3B = June 1953
  
 Also, you will see these small-bottle chrome-top Sylvania 6SN7GT and GTA with short bases and tall bases, still the same tube, same sound.


----------



## i luvmusic 2

You can make a dapter for 8 pin to 9 pin using a copper fitting(reducer) 1'' to 3/4''. or 3/4'' to 1/2 for 9 pin to 7 pin.


----------



## mab1376

What about EL34 as power tubes?


----------



## TrollDragon

mab1376 said:


> What about EL34 as power tubes?


The EL34 is a pentode, you would need 4 of them strapped as triodes and probably would not work in our LD configuration.


----------



## hypnos1

gibosi said:


> Actually, $37 for a pair plus $13 for shipping (to the States), so still not cheap.


 
  
 Thanks gibosi...I should look more closely. But yes, not cheap...then again, if you can find the 7N7 for the right price you could be on to a winner!
  
 A few more hours on the 7N7/Psvane combo and still WOW...I cannot believe it..._veeery_ interesting!


----------



## mordy

Hi hypnos 1,
  
 Firstly, I decided to try an all Russian all star lineup and use two 6P23N tubes for power tubes, and one for a driver. This worked quite well, and the bass became firmer and better controlled, without a feeling of hollowness. Nevertheless, real slam and attack in the bass is missing, but all-in-all a nice combination.
  
 Then I read your impressions of mixing two different power tubes and getting a synthesis of the best of them both. Sounds interesting; let's try it. So I swapped out one 6P23N for my trusty Hoffman (nee RCA) top heater wire 6SN7.
  
 Well, I listen through speakers and not headphones, and unfortunately I did not get any synthesis of the sound, but two distinct halves, right and left. The Hoffman side sounded full bodied and coherent with a fat round bass, and the Russki side sounded thin, akin to the difference in general between the 6N6P-IR tubes compared to the RCA 6SN7 octals when used as power tubes.
  
 In conclusion, this did not work for me, but it taught me that power tubes could make such a difference that I could clearly hear the difference, similar to hearing the differences between different sets of driver tubes.
  
 Now I am listening to the 6N23P as a driver with the RCA 6SN7 as power tubes. This is quite a good combination - the sound is open and forward with great detail and soundstage, except for a peculiar brightness bump in the upper midrange - we'll see if it gets better by time. The bass is very strong with great impact and slam; the mid bass is outstanding with a propensity to unlock the full bass potential of old 20's 78's (and everything else for that matter).
  
 Funny that the other way around (6N23P power and octal driver) it is only OK, but this way with 6N23P as driver and power octals it is quite good.
  
 About the upper midrange bump - I have four tubes, so I'll may try another one if it does not go away.


----------



## BbOO

Just received Little Dot MK III and wanted to try some new tubes. I just don't understand if i have to change all 4 tybes or just the two small ones?
 *n00b*


----------



## MIKELAP

bboo said:


> Just received Little Dot MK III and wanted to try some new tubes. I just don't understand if i have to change all 4 tybes or just the two small ones?
> *n00b*


 
 The 2 Tubes in the back are the POWER tubes and  the 2 in front are the DRIVER tubes . You can roll a few types of power tubes but there are  a lot more driver tubes to try out . The 6n6pir Russian power tubes are nice and cheap at around$13.00 each and are popular here's link http://www.ebay.com/itm/161171325915?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT                                                                                                                                                                                                                                                          For driver tubes alot of guys here like yugo's 6HM5 here's a link if interested offer $5.00 each  http://www.ebay.com/itm/300879467071?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT. For a list of  the  tubes you can try out go to page 77 of this thread post #1154. and remember not all tubes on that page are plug &play so best thing is to start reading around page 40 for the tubes on page 77 up to about page 200 + infos on power tubes on page 191


----------



## hypnos1

mordy said:


> Hi hypnos 1,
> 
> Firstly, I decided to try an all Russian all star lineup and use two 6P23N tubes for power tubes, and one for a driver. This worked quite well, and the bass became firmer and better controlled, without a feeling of hollowness. Nevertheless, real slam and attack in the bass is missing, but all-in-all a nice combination.
> 
> ...


 
  
 Yes mordy, this "mix and match" of power tubes is certainly going to be very "hit and miss" - with a good heap of luck thrown in!. And obviously is a no-go with tubes that are _too_ dissimilar. But if one has a good variety to play with I am sure it could just prove a worthwhile (if not interesting!) experiment...nothing to lose lol..
  
 As for my pairing of Psvane CV181- T II and short-bottle chrome-dome 7N7, with 20hrs burn-in for the adapter (the 7N7 being a used tube) I don't seem to be getting any mismatch whatsoever - the exact opposite in fact...my first WOW impressions have now been confirmed. I think I must have lucked-out BIG time, lol. 
	

	
	
		
		

		
			





 Mind you, it _could_ just be down to my right ear not being quite up to scratch compared to the left. So, just as astigmatism is remedied with lenses, the ear equivalent can apparently be remedied with _tubes_...methinks I just might have stumbled upon a very useful revelation indeed! And I'm sure I am not the only one with such a defect... Whatever, I personally seem to have struck gold...another reason for me NOT to continue with my mad quest to try the 6AS7 (_when_ they arrive). But curiosity is killing _this_ cat!
  
 Anyway mordy, keep playing around with different combinations - I'm sure you will find the 'magic' one soon...but you might just have to do a gibosi and try a lot more tubes yet in your search - all in a good cause, of course!!
  
 Happy rolling


----------



## gibosi

mordy said:


> Then I read your impressions of mixing two different power tubes and getting a synthesis of the best of them both. Sounds interesting; let's try it. So I swapped out one 6P23N for my trusty Hoffman (nee RCA) top heater wire 6SN7.
> 
> Well, I listen through speakers and not headphones, and unfortunately I did not get any synthesis of the sound, but two distinct halves, right and left. The Hoffman side sounded full bodied and coherent with a fat round bass, and the Russki side sounded thin, akin to the difference in general between the 6N6P-IR tubes compared to the RCA 6SN7 octals when used as power tubes.
> 
> In conclusion, this did not work for me, but it taught me that power tubes could make such a difference that I could clearly hear the difference, similar to hearing the differences between different sets of driver tubes.


 
  
 I think the 6SN7 and 6N32P are much too different to use in this way. Putting an RCA 6SN7 on one side and a Sylvania 6SN7 on the other might give you a better idea of what Hypnos1 is hearing with his 7N7, which is just a short-bottle Sylvania 6SN7 with a different base, and Psvane CV181, which is also just a 6SN7.


----------



## TrollDragon

I was chatting with a serious tube guy the other night and telling him about the rolling thread here... The first question he asked was WHY? Rolling tubes without the knowledge of how they operate and without doing the calculations and adjustments to the circuitry is basically pointless.

I told him we were looking for the best sounding tubes for the amp and he corrected me by saying that without doing any of the calculations and modifications we were just finding the "Least worst compatible tubes"...

Much truth to that and something to think about.


----------



## gibosi

trolldragon said:


> I was chatting with a serious tube guy the other night and telling him about the rolling thread here... The first question he asked was WHY? Rolling tubes without the knowledge of how they operate and without doing the calculations and adjustments to the circuitry is basically pointless.
> 
> I told him we were looking for the best sounding tubes for the amp and he corrected me by saying that without doing any of the calculations and modifications we were just finding the "Least worst compatible tubes"...
> 
> Much truth to that and something to think about.


 
  
 Well, one could argue that in rolling through the EF91, EF92, EF95 and 408A tubes, collectively speaking, we tried all the "compatible" tubes. And not satisfied, we decided to try everything and anything that looked like it might work, to see if we could find something better. And at this point in time, the so-called "least worst compatible" tubes I have been rolling recently are far-and-away better than the "compatible" tubes. (But of course, I should insert the standard disclaimer, "This is with my ears and gear".)
  
 This seems to me to be the old "measurements vs ears" debate.... and I freely admit my bias.... I trust my ears, even though they are old and well-worn....
  
 "If it measures good and sounds bad, it is bad. If it sounds good and measures bad, you've measured the wrong thing" - Daniel R. von Recklinghausen
  
 Cheers


----------



## hypnos1

gibosi said:


> Well, one could argue that in rolling through the EF91, EF92, EF95 and 408A tubes, collectively speaking, we tried all the "compatible" tubes. And not satisfied, we decided to try everything and anything that looked like it might work, to see if we could find something better. And at this point in time, the so-called "least worst compatible" tubes I have been rolling recently are far-and-away better than the "compatible" tubes. (But of course, I should insert the standard disclaimer, "This is with my ears and gear".)
> 
> This seems to me to be the old "measurements vs ears" debate.... and I freely admit my bias.... I trust my ears, even though they are old and well-worn....
> 
> ...


 
  
 Hey gibosi. You've hit the nail RIGHT on the head...I don't think our collective appraisals and results can be discounted just because we haven't done the maths...OK, it might take us _much_ longer, and have to kiss a hell of a lot of frogs before finding the 'Prince', but that is also a good part of the fun - not to mention great camaraderie - in what we have been doing for a good while now. And isn't it just GREAT when we do hit upon the Prince/Princess!?...I for one wouldn't have wanted to miss all we have been through, no matter how "pointless" some may want to call our efforts/pain/trials/enterprising spirit/education...not to mention fun and joy...I rest _my_ case also...
  
 Carry on folks....take ye not any heed of disbelievers!


----------



## i luvmusic 2

After 24 hours of burn-in for my 6SN7 GTA Sylvania Chrome top from1953 and 1954 the sound it improved alot at first i was a bit disapointed how bright/harsh it sound and now they are not harsh at all  i love them they are more detailed than my RCA black plates these 6SN7's are really a nice tube for my LD amp.These is where i'am going to stopped buying 6SN7's i do have more than enough to play with my LD it's time for me to look for any other type of amp that it can use 6SN7's i'am wondering about Bottlehead Crack.


----------



## i luvmusic 2

It's time for me to try the 6AS7 as power tubes.....


----------



## i luvmusic 2

Still waiting for the tubes to cooldown for tube changed.I hoped you guys can come up with another type of tubes that we can use with LD.These 6SN7 is killing my wallet i need something inexpensive
	

	
	
		
		

		
		
	


	




.


----------



## gibosi

i luvmusic 2 said:


> ......it's time for me to look for any other type of amp that it can use 6SN7's i'am wondering about Bottlehead Crack.


 
  
 The Crack comes with a 9-pin miniature socket with the heaters configured to run 12AU7 tubes in 6 volt mode. Some have reported that they have successfully rolled 6SN7. However, others have reported that the 6SN7 is too noisy. I suspect that one could use the same external DC heater PS you have been using in the LD, and that would solve the noise problem. And further, you should be able roll ECC40, E80CC, 2C51, 7N7, 7AF7 and so on.....
  
 Unfortunately for me, the Crack is designed to work with 200 Ohm headphones and up. If it could drive lower impedance phones, I would probably get one.


----------



## i luvmusic 2

Oops my bad can't try 6AS7 for now i need to wait for my regulator comming from Chinada(it's on speedboat) i just tried the 6AS7 and it did overloaded my 5A regulator 2 6AS7 and 1 6SN7(5.6A) is to much for my 5A regulator.I forgot about that regulator inside my power supply.FAIIIIIIIIIIL


----------



## i luvmusic 2

gibosi said:


> The Crack comes with a 9-pin miniature socket with the heaters configured to run 12AU7 tubes in 6 volt mode. Some have reported that they have successfully rolled 6SN7. However, others have reported that the 6SN7 is too noisy. I suspect that one could use the same external DC heater PS you have been using in the LD, and that would solve the noise problem. And further, you should be able roll ECC40, E80CC, 2C51, 7N7, 7AF7 and so on.....
> 
> Unfortunately for me, the Crack is designed to work with 200 Ohm headphones and up. If it could drive lower impedance phones, I would probably get one.


 
 The only thing that making me think twice is i listen to my Q#@ rather than my DT8@# 600 ohms but i'am still looking into it i really like to build my first tube amp.


----------



## mordy

Hi All,
  
_"Rolling tubes without the knowledge of how they operate and without doing the calculations and adjustments to the circuitry is basically pointless._
_I told him we were looking for the best sounding tubes for the amp and he corrected me by saying that without doing any of the calculations and modifications we were just finding the "Least worst compatible tubes"..._
  
 TD, why don't you ask your friend which calculations and adjustments to make?
  
 hypnos 1, I agree completely with you about all the fun and exciting discoveries we have made, not to mention the tremendous upgrade in the sound of the LD amps.
  
 Right on, Gibosi!
_"Well, one could argue that in rolling through the EF91, EF92, EF95 and 408A tubes, collectively speaking, we tried all the "compatible" tubes. And not satisfied, we decided to try everything and anything that looked like it might work, to see if we could find something better. And at this point in time, the so-called "least worst compatible" tubes I have been rolling recently are far-and-away better than the "compatible" tubes."_
  
 Something tells me that we would not have achieved the heights we have reached if we followed the advice of TD's friend.....
  
 When I hear the expression "the least worst compatible tube" all I can think of is this:
  

  
 PS: Stay tuned for a report on a great underrated and inexpensive tube: the 6BL7.


----------



## kvtaco17

mordy said:


> Hi All,
> 
> _"Rolling tubes without the knowledge of how they operate and without doing the calculations and adjustments to the circuitry is basically pointless._
> _I told him we were looking for the best sounding tubes for the amp and he corrected me by saying that without doing any of the calculations and modifications we were just finding the "Least worst compatible tubes"..._
> ...


 
  
 and on top of that I'll be testing 6f8g's soon!


----------



## TrollDragon

I am not stirring up the pot or trying to get anyone's knickers in a knot, just passing along information from a person who has worked with tubes all their life, repairs and designs amplifiers.

Then again he mostly works with amps that have a B+ greater than 350V so things can get out of hand quickly when tube theory is not applied and followed.


----------



## hypnos1

trolldragon said:


> I am not stirring up the pot or trying to get anyone's knickers in a knot, just passing along information from a person who has worked with tubes all their life, repairs and designs amplifiers.
> 
> Then again he mostly works with amps that have a B+ greater than 350V so things can get out of hand quickly when tube theory is not applied and followed.


 
  
 Hi TD.
  
 No offence taken, mon ami - can see where you're coming from...the pro is _always_ going to be looking at things differently to the semi-, or amateur. And usually becomes bogged down in theory (certainly in higher voltage land)...whereas _we_ are much more into _practice_! There is a place for BOTH in this world...
  
 I am sure I speak for us all when I say we do appreciate your contribution to this thread...keep it up! 
	

	
	
		
		

		
		
	


	



  
 Cheers


----------



## i luvmusic 2

hypnos1 said:


> Hi TD.
> 
> No offence taken, mon ami - can see where you're coming from...the pro is _always_ going to be looking at things differently to the semi-, or amateur. And usually becomes bogged down in theory (certainly in higher voltage land)...whereas _we_ are much more into _practice_! There is a place for BOTH in this world...
> 
> ...


----------



## mordy

_Hi TD._
  
_No offense taken, mon ami - can see where you're coming from...the pro is always going to be looking at things differently to the semi-, or amateur. And usually becomes bogged down in theory (certainly in higher voltage land)...whereas we are much more into practice! There is a place for BOTH in this world..._
  
_I am sure I speak for us all when I say we do appreciate your contribution to this thread...keep it up! 
	

	
	
		
		

		
		
	


	


_ 
  
  
 Ditto, keep up the good work! BTW, what happened to the protective circuit for DC coupled amps from the British designer?


----------



## maxipad

I think it's a pretty good review that hit most of what I felt about a lot of those tubes right on the head.  I love my Tung-Sol tubes and my Voshkods.  The other ones don't really get any amp time.


----------



## TrollDragon

mordy said:


> Ditto, keep up the good work! BTW, what happened to the protective circuit for DC coupled amps from the British designer?


 
 This was the last communication I got from him at the end of March.
  


> Looking forward to seeing the next review on the tube amp. When I get in the new house I will finally send you the LDP that I have all the parts for..! and an amplifier.


 
  
 Just waiting for him to get settled down in his new house.


----------



## maxipad

Hey so one of my tubes split open on the bottom.  What could have caused this?  It was a fairly old tube (1945)  but it worked fine (was kind of microphonic though)  so I swapped it out and noticed the split.


----------



## gibosi

maxipad said:


> Hey so one of my tubes split open on the bottom.  What could have caused this?  It was a fairly old tube (1945)  but it worked fine (was kind of microphonic though)  so I swapped it out and noticed the split.


 
  
 We need a bit more information.... For example, what kind of tube?


----------



## maxipad

gibosi said:


> We need a bit more information.... For example, what kind of tube?


 
 JHY-6AK5 Hytron


----------



## gibosi

maxipad said:


> JHY-6AK5 Hytron


 
  
 OK.... An all-glass 7-pin miniature and the glass base cracked... You have my condolences... 
  
 But as you pointed out, it is close to 70 years old.  And while this doesn't happen everyday, it is not all that unusual. Whenever I find a tube I really like, I always try to get a couple extras, because it is impossible to predict if and when one might give up the ghost....


----------



## maxipad

gibosi said:


> OK.... An all-glass 7-pin miniature and the glass base cracked... You have my condolences...
> 
> But as you pointed out, it is close to 70 years old.  And while this doesn't happen everyday, it is not all that unusual. Whenever I find a tube I really like, I always try to get a couple extras, because it is impossible to predict if and when one might give up the ghost....


 
 Haha yeah, I mostly figured it was because it was so old.  I got probably 6mo use out of them as well, so it wasn't like it split right after I got it either.  I was honestly kind of proud that I've finally listened to my amp enough to have a tube go bad (then again using one from 1945 might have been cheating a little).  I've already moved on to some 1956 6AK5W Tung-Sol tubes (turns out I have a bunch of them laying around!) and I'm happy as can be.    Honestly when all else fails I just go back to the Voshkods since they sound really... really... really good.


----------



## hypnos1

Update on the Psvane CV181-T II/7N7 (short-bottle) power combo...
  
 Now with the adapters well run-in, they are still defying all previous thoughts on "mix and match" (when using just 1 tube per channel).
 A happier marriage you could not hope for - there is no clash/imbalance/over-dominance whatsoever...so WHY IS THIS? :
 To ascertain how much may be down to my "unbalanced" ears, I swapped L to R and...no noticeable (negative) difference. So, thankfully, my less-than-perfect right ear is obviously not impeding too much on my listening pleasure...nice to know!
  
 So what now?...A clue came from a derogatory comment on the 6SN7 rolling thread, viz the Psvane being "girlie". This I suspect came from a "macho man" - anything that can surpass a 6N30P-DR is no slouch in _my_ book. What I think is a more accurate description is a well-rounded and balanced presentation, not "in your face" or overtly dramatic, but more delicate/subtle. In this respect I suppose one could actually say (Old World!) "feminine". Now most of the time I personally find this trait much more attractive (am no headbanger, me!), but sometimes a bit more "masculinity" can of course bring another dimension - _power_ (unless the gal is an 'Amazonian!'). This, I am beginning to think, could well be one of the main reasons for my combo's successful pairing...yin and yang, if you will. With _neither_ being dominant, but the two creating the whole...
  
 Plus, of course, a great deal of luck in there being no major clashes technically/electrically!.
  
 Well, that's _my_ take on this "conundrum" anyway. Whatever, I am now getting the most satisfying sound that has ever emanated from this humble machine - no matter what the purists may say...but of course _no-one_ on this planet is going to have the _exact_ same set-up as mine, so perhaps very few people are actually going to be as lucky in their findings as I have been. But I am sure I cannot be the _only_ one for this phenomenon to "come together"...or am I?! 
	

	
	
		
		

		
		
	


	




 
  
 Edit...a couple of pics...


----------



## hypnos1

kvtaco17 said:


> and on top of that I'll be testing 6f8g's soon!


 
  
 Can't wait to get your feedback on the 6F8g - looks like many prefer that over the 6SN7...but what on earth is going on with the price of these things? Perhaps they became TOO popular, lol?!


----------



## kvtaco17

Just waiting on the adapter to come...


----------



## mab1376

hypnos1 said:


> Can't wait to get your feedback on the 6F8g - looks like many prefer that over the 6SN7...but what on earth is going on with the price of these things? Perhaps they became TOO popular, lol?!


 
  
 Yeah I considered testing them, but couldn't justify the price.
  
 If I could find a respectable pair for >$60 i'd give it a shot, but you would still need adapters.


----------



## hypnos1

mab1376 said:


> Yeah I considered testing them, but couldn't justify the price.
> 
> If I could find a respectable pair for >$60 i'd give it a shot, but you would still need adapters.


 
  
 Hi mab.
  
 As has been mentioned elsewhere, I am sure dealers keep an eye on us all in these forums with a "view to a kill"...very murky goings-on indeed!...Or am I just being my old cynical self?
  
 Ah well, if our LDs can continue to be _extra_ versatile, perhaps the 6C8g might be a better option?...depending on who's watching us! They appear to be just as good as the 6F8g, but much cheaper (a nice-looking pair went for $24 earlier today). Would need to have a close look at the electrical differences though....
  
 Will certainly be interesting to hear our colleague's findings however...


----------



## mab1376

hypnos1 said:


> Hi mab.
> 
> As has been mentioned elsewhere, I am sure dealers keep an eye on us all in these forums with a "view to a kill"...very murky goings-on indeed!...Or am I just being my old cynical self?
> 
> ...


 
  
 Ha interesting perspective. I'm sure they're all watching...
  
 I'll definitely consider the 6C8G if i can confirm using the 6F8G - 6SN7 adapter so i can use them as power tubes.
  
 The Tung Sol VT-99 (6F8G) seems to be cream of the crop going for about $250.


----------



## hypnos1

Further to my previous post re power tube combo, I can confirm that they are definitely performing better than either pair of Psvane or VT231.
  
 The added "masculinity" of dynamism is most suredly there...I suppose I could now term my rig "Amazonian gal", or LD Xena (Warrior Princess?)!!
  
 Enough of analogy...back to some "proper" tube-speak (mind you, I feel that "analogy" can often convey much more). What seems to have been addressed is the slight veiling of the C3gS's wonderful clear detail resolution and "airiness" when partnered with the VT231s. And since this is (one of) the C3g's truly magical qualities, it is a real joy to have it back PLUS the extra dynamism and mids detail.
  
 I am now utterly convinced that with the C3Gs in the driver's seat of the MKIV SE (and other models it looks like), the sky's the limit! All that's needed is a fatter wallet, unfortunately...especially now the prices of what we could yet try have gone ballistic! 
	

	
	
		
		

		
		
	


	



  
  
 ps. The dreaded 6AS7s have arrived, but not yet the 8A regulator...so the fateful day will have to wait until after the hols...
	

	
	
		
		

		
		
	


	



  
 BFN


----------



## gibosi

hypnos1 said:


> Ah well, if our LDs can continue to be _extra_ versatile, perhaps the 6C8g might be a better option?...depending on who's watching us! They appear to be just as good as the 6F8g, but much cheaper (a nice-looking pair went for $24 earlier today). Would need to have a close look at the electrical differences though....


 
  
 The 6C8G has .3 amp heaters, and appears to be somewhat similar to a 6SL7 or 7AF7. As usual, since I have no power tubes, I am going on gut feeling here, but I suspect that like the 6DJ8, this tube just doesn't have enough current, or "power" if you will, to do well as an output tube. However, as a driver tube it should be perfectly fine. I have run the 7AF7 as a driver, and found it to be a very nice tube. As the 6D8G has the same pin-out as the 6F8G, the same adapter can be used.


----------



## gibosi

mab1376 said:


> The Tung Sol VT-99 (6F8G) seems to be cream of the crop going for about $250.


 
  
 The National Unions also seem to get a lot of love.


----------



## Nic Rhodes

Sylvania and RCA should also be very affordable still, Tung Sol carry  a massive premium nowdays.


----------



## mordy

Hi Gibosi and hypnos 1,
  
 Have been thinking about how to pair different power tubes to get a synergistic effect. My first try resulted in hearing two distinct halves of the music using a 6DJ8 and 6SN7 type tube. Acting upon Gibosi's suggestion to use similar (sounding) tubes I got better results.
  
 At this point my thinking is that you need to match two similar tubes with complementing characteristics ( detailed/analytical + musical as an example). Could also be that they have to play similarly loud to get the right effect.
  
 Right now I am trying two 6SN7 tubes, a RCA top heater wire and a Japanese tube. The RCA is more musical and the Japanese more detailed. I get a coherent sound stage that sounds very nice, but I need more time with this setup to finalize my impressions. (Something is bothering me, but I can't put my finger on it.)
  
 The driver is a 1952 Philco/Sylvania 6BL7 1.5A tube. This tube has an amplification factor of 15 compared to the 6BX7 with an amplification factor of 10. Otherwise these two tubes sound similar with great clarity and punch. In the words of Nic Rhodes, these are cracking/awesome tubes and available at real bargain prices. IMHO I would recommend trying these tubes before spending megabucks on hyped up boutique tubes.
  
 Now, could I use a combination of one 1.5A tube + one 0.9A tube as power tubes in the LD MKII? As I understand it, the transformer can handle up to 2.5A.
  
 Before I try it, I would like to hear if this is safe - thanks.


----------



## mab1376

So a few weeks with the C3gS/6SN7 combo and i'm still loving it, an absolute perfect match with the HD650's
  
 It also sounds amazing with my TT setup as a preamp playing through my Klipsch Forte speakers.
  
 However my T70's still have a slight buzz when not playing music, its completely inaudible when playing music so i'm suspecting due to the extremely high sensitivity of those headphones that i'm picking up some noise from the AC heaters.
  
 Either way still a great setup and highly recommended.
  
 I am still curious ho some other tube variants would work as power tubes, i'm very anxious to try some 6F8G or their cheaper variants, but i'll hold off for now until someone has some solid feedback on how they are.


----------



## Rossliew

Just took delivery of 2 pairs of driver tubes - a pair of Tung sol 6AJ5 and a pair of blue BTB EF95. The Tungsol had a fuller bodied sound with good bass impact whilst the blue BTBs had a leaner sound. Decided to get adventurous and mixed the tubes - 6AJ5 on the left and BTB on the right. Nice balance. Not entirely distinguishable differences in sound although bass lines where more rumbling, so to speak and mids/vocals were more pinpoint centric. Will listen a bit more and see if the sound changes (or my ears get accustomed to the sound)..


----------



## gibosi

mordy said:


> Now, could I use a combination of one 1.5A tube + one 0.9A tube as power tubes in the LD MKII? As I understand it, the transformer can handle up to 2.5A.
> 
> Before I try it, I would like to hear if this is safe - thanks.


 
  
 Mordy,
  
 I think we have to assume that it is not safe to run a power tube that draws more than 1.25A. Even though the transformer appears to be good up to 2.5A, you cannot assume that the wiring supplying each tube can handle more than half of that. So, you might be able to get away with 1.5 amps, but then again, you might not....


----------



## gibosi

Received a Sylvania subminiature 7963 double triode today.  I was very intrigued by this thread:
  
 http://rockgrotto.proboards.com/thread/9798/sylvania-7963-best-e88cc-planet?page=1&scrollTo=134293
  
 As you can see in this photo, it is indeed very small compared to a Voshkod 6N23P. So now I just have to figure out how to connect this little guy to my breadboard socket. lol


----------



## hypnos1

mordy said:


> Hi Gibosi and hypnos 1,
> 
> Have been thinking about how to pair different power tubes to get a synergistic effect. My first try resulted in hearing two distinct halves of the music using a 6DJ8 and 6SN7 type tube. Acting upon Gibosi's suggestion to use similar (sounding) tubes I got better results.
> 
> At this point my thinking is that you need to match two similar tubes with complementing characteristics ( detailed/analytical + musical as an example). Could also be that they have to play similarly loud to get the right effect.


 
  
 Spot on mordy...that's _precisely_ what I am getting with my Psvane/TS (Sylvania) 7N7 combo, and things just keep getting better ( I really can't get my head round what is happening!)...so good hunting!!


mab1376 said:


> So a few weeks with the C3gS/6SN7 combo and i'm still loving it, an absolute perfect match with the HD650's
> 
> It also sounds amazing with my TT setup as a preamp playing through my Klipsch Forte speakers.
> 
> However my T70's still have a slight buzz when not playing music, its completely inaudible when playing music so i'm suspecting due to the extremel


 
  
 Real glad you're still loving the C3gSs...awesome indeed! And my 650s love 'em too....they were made for each other, that's for sure.
 And partnered with my power combo, the  650s  are delivering a sound WAY beyond their relatively "cheap" price. Looks like synergy, synergy and _more_ synergy! I'm now truly in sound heaven 
	

	
	
		
		

		
			





.


----------



## i luvmusic 2

gibosi said:


> Received a Sylvania subminiature 7963 double triode today.  I was very intrigued by this thread:
> 
> http://rockgrotto.proboards.com/thread/9798/sylvania-7963-best-e88cc-planet?page=1&scrollTo=134293
> 
> As you can see in this photo, it is indeed very small compared to a Voshkod 6N23P. So now I just have to figure out how to connect this little guy to my breadboard socket. lol


 
 You can solder 18 AWG solid copper wire then heatshrink all the terminals(individualy) and put a piece of round wood or plastic in the middle of all the terminals the same width with your socket on the breadboard then heatshrink the whole thing leaving enough copper to plug into the socket so now you have tube with built in adapter.You can used a ballpen tube cut to lenght then you wrapped electrical tape or heatshrink to get the width that you need.


----------



## gibosi

That's a great idea.... but I couldn't wait! lol 
  
 So I rewired the socket for this tube and then simply screwed the tube's wire leads into the compression blocks.... And it works! 
  
 I did find that it is very important to keep a fair amount of distance between the wires connecting the two plates in order to avoid what sounds like a strong ground hum.
  
 First impression... It sounds great!  However, whether I think it is in fact the "best sounding E88CC / 6922 / 6DJ8 / ECC88 on planet Earth" as the reviewer on Rockgrotto wrote will take considerably more time to determine....
  
 So my fellow tube rollers, add the Sylvania subminiature 7963 to the LD rolling list!


----------



## mordy

Hi Gibosi,
  
 The Sylvania 7963 is a *frame grid* tube. Here is a link to a post describing what a frame grid tube is - the writer obviously was not aware of the Sylvania 7963 tube:
  
 http://www.head-fi.org/t/452721/fs-tesla-e83cc-gold-pin-nos-1-1-to-telefunken-ecc803s#post_6117913
  
 Interesting....


----------



## gibosi

mordy said:


> The Sylvania 7963 is a *frame grid* tube. Here is a link to a post describing what a frame grid tube is - the writer obviously was not aware of the Sylvania 7963 tube:
> 
> http://www.head-fi.org/t/452721/fs-tesla-e83cc-gold-pin-nos-1-1-to-telefunken-ecc803s#post_6117913
> 
> Interesting....


 
  
 The ECC803S is considered by some as one of the "Holy Grail" tubes, very rare and evidently, very good. But it seems that the writer is only concerned with the ECC83 family of tubes. This overlooks the fact that the 6DJ8 is also a frame grid tube, as is the E80CC, the C3g, and the 7693. And there may well be others I don't know about.....


----------



## mordy

Recently so many great choices of tubes for the LD amps have become unearthed, and to me it is almost confusing. I do remember posts on this forum describing sub miniature dual triode tubes, and at one point I even dug up a list of possible choices. However, those octopus like wire leads scared me away since I did not know how to make an adapter. How do you know which lead is which? Probably a reference notch or some such.
  
 Now Gibosi came up with such a simple idea: Simply screw in the leads into the breadboard compression blocks! Great!
  
 Don't know how practical the following idea is, but are there little sleeves that could be put on regular tube pins and then an 18 gauge solid insulated wire could be crimped on to other end of the sleeve and inserted directly into the tube socket (or the breadboard)?
  
 Anyhow, now that I discovered that I have a stash of the coveted frame grid 6DJ8 tubes I ought to give them more exposure.
  
 Meanwhile I am trying out oldies but goodies. Two Sylvania 1950's 6SL7GTW tubes serve as power tubes, and another Sylvania 6BL7 serves as the driver. This 6BL7 tube is built like a tank with three micas, copper posts, and dual heaters top and bottom. It is labeled Automatic Radio.
  
 Automatic Radio was a Boston radio manufacturer that existed from the 20's to 1957. It's most famous radio was the a miniature portable radio called Tom Thumb. Here is a tube version:
  








  
 Coming back to the SL-BL setup: The power tubes add an elegant lightness and delicious detail to the presentation. (Sorry, at the moment I can't think of better words to describe the sound)
  
 Can't resist sharing these pictures of a Tesla radio and speaker:
  




  




  
 Good Night!
  
 BTW, the US Tesla electric car company settled with the Chech Tesla electronic company about the trademark name; amount not disclosed.


----------



## gibosi

mordy said:


> .........I do remember posts on this forum describing sub miniature dual triode tubes, and at one point I even dug up a list of possible choices. However, those octopus like wire leads scared me away since I did not know how to make an adapter. How do you know which lead is which? Probably a reference notch or some such.


 
  
 The 7963 has 8 wire-leads coming out of the base. There is a slightly larger gap between wire-lead #1 and wire-lead #8, similar to the larger gap between pin #1 and pin #9 on a 9-pin tube.
  
 I have been thinking of putting this tube into an Octal base. It should be a simple matter to route the wires into the pins and solder them. It will certainly look strange, but it should work quite well.


----------



## TrollDragon

Will look no stranger than this one does...


----------



## mordy

In lieu of the 5670/2c51 tube, has anybody tried the Russian 6N3P or the Chinese 6N3-J tubes?
  
 Gibosi, do you have to cross wires inside the octal base to accommodate the 7963 tube? How do you insulate them and or reduce hum?


----------



## Nic Rhodes

I am not a fan of the Chinese, even the JunDui doesn't do it for me. The best Russian is the DR variant but still prefer the Western 2C51s.


----------



## gibosi

mordy said:


> Gibosi, do you have to cross wires inside the octal base to accommodate the 7963 tube? How do you insulate them and or reduce hum?


 
  
 I am quite sure some of the wires would cross, so it will be necessary to insulate them in some fashion. As *i lovemusic 2* suggested, a spent ballpoint pen ink tube and some electrical tape might do the trick, or if one has a heat gun, some heat-shrink tubing.
  
 The rock grotto posting I referenced above shows the tube mounted into a 9-pin socket saver with heat-shrink tubing.
  
 http://rockgrotto.proboards.com/thread/9798/sylvania-7963-best-e88cc-planet?page=1&scrollTo=134293


----------



## i luvmusic 2

I want to try this tube(Sylvania subminiature 7963)but it is CAD $22 plus shipping wow....


----------



## gibosi

i luvmusic 2 said:


> I want to try this tube(Sylvania subminiature 7963)but it is CAD $22 plus shipping wow....


 
  
 Yeah, it's pretty crummy. If you check eBay's sold listings, a lot of 5 went for only $19.99, with free shipping in the states, just a few months ago. Now they are going for 5 times that! 
  
 There is currently one listing on eBay for $24, or best offer. My first offer was 3 for $30, and it was refused. My second offer was 2 for $30, and that offer was refused as well. Finally, I offered to buy just one for $20 and was accepted. Shipping in the states is $4, so it appears that for now, $24 is about cheap as we are going to get. However, it just might be possible to find them from sources outside of eBay for less....
  
 I figure that there can't be that much demand for these as the wire leads limits them to tinkerers. Perhaps in a few months we will see the prices on eBay go back down.....


----------



## Nic Rhodes

There are plenty of other good wired leadout tubes people may want to try that are more conventional in size like CV4033 (12AT7 / ECC81), CV4034 (12AU7 / ECC82), CV4035 (12AX7 / ECC83), CV4109 (7308 / E188CC), CV4069 (13D3). All of the listed CV numbers are 'premium' examples.
  
 Others of note but not relevant here CV4001 (6X4 / EZ90), CV4086 (EF86).


----------



## gibosi

For the 7963, 6832 and perhaps other sub-miniature "Pencil" double triodes.....
  
 Mordy asked for a diagram indicating how to wire the external socket to the Vectors, so I thought I should also post it here:
  
 Holding the tube upside down, the gap between lead #1 and lead #8 is a bit wider than the others, just like it is on our 7-pin and 9-pin tubes. And like those tubes, upside down, #1 is on the left and you go around the tube clockwise ending at #8.
  
 9 Pin socket                                 Left LD socket                    Right LD socket
  
 1 plate triode 2                                                                                   5
 2 grid triode   2                                                                                   1
 3 heater -- external PS or                                                                     3
 4 cathode triode 2                                                                               2
 5 cathode triode 1                                    2
 6 heater -- external PS or                                                                     4
 7 grid triode 1                                          1
 8 plate triode 1                                         5
 9 not used


----------



## Androb

trolldragon said:


>


 
 That looks pretty badass!!!
  
 Anyway here is my LD that I changed tubes on


----------



## MIKELAP

Can you guys see any tubes in these pictures that are usable with the littledot or with a power supply. Thanks


----------



## gibosi

mikelap said:


> Can you guys see any tubes in these pictures that are usable with the littledot or with a power supply. Thanks


 
  
 A quick look...
  
 In pic#1, there is an 8FQ7/8CG7 top center
 In pic#2, there are a couple of 12Bh7
 In pic#3, there are a couple 8FQ7 and a 6CG7/6FQ7
  
 So I don't see any treasures, but again, it was just a quick look....


----------



## gibosi

androb said:


> That looks pretty badass!!!
> 
> Anyway here is my LD that I changed tubes on


 
  
 What were your old tubes?  And what are your new tubes?


----------



## MIKELAP

gibosi said:


> A quick look...
> 
> In pic#1, there is an 8FQ7/8CG7 top center
> In pic#2, there are a couple of 12Bh7
> ...


 
 Thanks alot gibosi  found around 35 tubes in all in that box nothing spectacular but usable, they belong to my kid brother so he told me ,take what you need he didnt tell me twice lol. Thanks again.


----------



## TrollDragon

androb said:


> That looks pretty badass!!!
> 
> Anyway here is my LD that I changed tubes on


 
 Thanks!
  
 Get out of here... teasing us with your Balanced MK VI+ and the Svetlana 6H5C's


----------



## Androb

trolldragon said:


> Thanks!
> 
> Get out of here... teasing us with your Balanced MK VI+ and the Svetlana 6H5C's :tongue_smile:


Hehe 

Gibosi i'm not but I think they are called RCA 6080. They sound a bit congested compared to these tubes!


----------



## gibosi

I got a Mullard 6SN7GTY today!
  

  
 But everyone knows that Mullard NEVER EVER made a 6SN7.... Right? 
  
 And the flip side reveals that this is actually a BRIMAR CV1988 made in the Oldsway factory (FE)
  

  
 I believe the date code of XB = February, 1965. But in the next picture, below, 3J5 = Week 3, Month J, Year 5, several months later. Maybe this is the packing date?
  
 And I do not know what the number 383 indicates.


----------



## Oskari

gibosi said:


> I got a Mullard 6SN7GTY today!
> 
> But everyone knows that Mullard NEVER EVER made a 6SN7.... Right?


 
  
 Right. The print job looks pretty rough.
  


> And the flip side reveals that this is actually a BRIMAR CV1988 made in the Oldsway factory (FE)


 
  
 Believe it or not, the STC Oldway site was right here, next to a mansion of the same name:
  

http://goo.gl/maps/7o7i6
  


> I believe the date code of XB = February, 1965. But in the next picture, below, 3J5 = Week 3, Month J, Year 5, several months later. Maybe this is the packing date?


 
  
 X is actually 1966. This is easier to explain: the CV labels were often printed later.
  


> And I do not know what the number 383 indicates.


 
  
 It could be a type code. Not mentioned here, though:
  

http://myweb.tiscali.co.uk/g8hqp/audio/brimarcodes.html


----------



## kvtaco17

My 6FG8 has arrived! Its an inexpensive RCA
  

 A little size comparison to my Golden Arrow 6SN7 shorty...
  
  

  

  

  

  

  
 She's a big one! lol We'll see how she sounds when my adapter arrives!


----------



## Rossliew

Hi, anyone have experience rolling in the following Full Music 6SN7 tube?
  
 http://www.ebay.com/itm/Matched-Pair-2x-TJ-Full-Music-NIB-6SN7-ECC32-tubes-Gold-Pins-Test-NEW-/171226764798
  
 Believe this is a Chinese tube but why so expensive? Any impressions on the sound with a LD Mk 3 + HD800? thanks!


----------



## kvtaco17

rossliew said:


> Hi, anyone have experience rolling in the following Full Music 6SN7 tube?
> 
> http://www.ebay.com/itm/Matched-Pair-2x-TJ-Full-Music-NIB-6SN7-ECC32-tubes-Gold-Pins-Test-NEW-/171226764798
> 
> Believe this is a Chinese tube but why so expensive? Any impressions on the sound with a LD Mk 3 + HD800? thanks!


 
 Nope, but they sure are nice looking...


----------



## i luvmusic 2

WOW hundreds of $ for a tube for -$300 tube amp.


----------



## Rossliew

i luvmusic 2 said:


> WOW hundreds of $ for a tube for -$300 tube amp.


 
 That gets me wondering why this particular brand of tube should be so expensive...


----------



## i luvmusic 2

I'm loving my $7 Russian 6AS7 for my LD 1 if i will spent that kind of money for a tube it will be for a better amp than my LD 1 and LD MK III.Most money i spent on tube is $30 with shipping and that was my first Octal(GE 6SL7) and now i only buy 6SN7 by lot not singles for me single tube cost more than 2+ tubes(equal to $10 per tube).


----------



## i luvmusic 2

How do you guys store your TUBES?
 Most of my tubes have no box and everytime i open the drawer i can hear them knocking each other i'm afraid that they may break.
 Any sugestions.THANK YOU!


----------



## kvtaco17

i luvmusic 2 said:


> How do you guys store your TUBES?
> Most of my tubes have no box and everytime i open the drawer i can hear them knocking each other i'm afraid that they may break.
> Any sugestions.THANK YOU!


 
 I have spare white tube boxes... they then go in a shoe box and then a big plastic tub OR if they are in rotation they stay in a drawer near my amps.


----------



## gibosi

i luvmusic 2 said:


> WOW hundreds of $ for a tube for -$300 tube amp.


 
  
 Well, you have to remember that most people run the 6SN7 in more expensive amps, such as DarkVoice, Woo, Carver and so on. My $100 LD1+ was never designed to use these tubes. lol.
  
 Also, these are new production tubes. It is very expensive to set up a factory and manufacture vacuum tubes. Moreover, the demand for new vacuum tubes is quite small. After all, how many people do you know who are out looking for new vacuum tubes? Worse, many of the people who do want to purchase vacuum tubes think the 60 year-old tubes sound better. So this is very different than manufacturing computer parts on a very large scale to supply a very large demand. And it is impossible for them to sell their brand new vacuum tubes very cheaply and make any money.


----------



## i luvmusic 2

kvtaco17 said:


> I have spare white tube boxes... they then go in a shoe box and then a big plastic tub OR if they are in rotation they stay in a drawer near my amps.


 
 Thank You! Yup i just ordered some white tube boxes from the Tube depot.


----------



## i luvmusic 2

I did not know you can buy just the boxes.


----------



## i luvmusic 2

kvtaco17 said:


> My 6FG8 has arrived! Its an inexpensive RCA
> 
> 
> A little size comparison to my Golden Arrow 6SN7 shorty...
> ...


 
 Do you need to use the pin on top?


----------



## gibosi

i luvmusic 2 said:


> How do you guys store your TUBES?
> Most of my tubes have no box and everytime i open the drawer i can hear them knocking each other i'm afraid that they may break.
> Any sugestions.THANK YOU!


 
  
 Like Kvtaco 17, I use white tube boxes to store tubes that come without boxes.
  
 http://www.ebay.com/itm/25-White-Vacuum-Tube-Boxes-6V6-6SN7-5Y3-FAST-SHIP-/171309847519?pt=Vintage_Electronics_R2&hash=item27e2dcd3df
  
 The boxes are stored in an old chest-of-drawers, octals in one drawer, 9-pin double triodes in another, and so on.


----------



## gibosi

i luvmusic 2 said:


> Do you need to use the pin on top?


 
  
 The pin on top is tied to the cathode for one of the triodes. A special adapter is needed, 6F8G on top and 6SN7 on the bottom:
  
 http://www.ebay.com/itm/1pc-6F8G-TO-6SN7-6SL7-TUBE-ADAPTER-/190991571450?pt=Vintage_Electronics_R2&hash=item2c77fc19fa


----------



## i luvmusic 2

gibosi said:


> Like Kvtaco 17, I use white tube boxes to store tubes that come without boxes.
> 
> http://www.ebay.com/itm/25-White-Vacuum-Tube-Boxes-6V6-6SN7-5Y3-FAST-SHIP-/171309847519?pt=Vintage_Electronics_R2&hash=item27e2dcd3df
> 
> The boxes are stored in an old chest-of-drawers, octals in one drawer, 9-pin double triodes in another, and so on.


 
 I bought mine from the tubedepot $19 for 100pcs + killer USA shipping to Canada but still cheaper than buying it locally.Thanks! for the link.


----------



## i luvmusic 2

gibosi said:


> The pin on top is tied to the cathode for one of the triodes. A special adapter is needed, 6F8G on top and 6SN7 on the bottom:
> 
> http://www.ebay.com/itm/1pc-6F8G-TO-6SN7-6SL7-TUBE-ADAPTER-/190991571450?pt=Vintage_Electronics_R2&hash=item2c77fc19fa


 
  
 For the adapter it should be easy to reconfigure my adapter for that tube but Holy schiit that(6F8G)tube is not cheap.


----------



## kvtaco17

my RCA was 25 shipped... Lol


----------



## MIKELAP

i luvmusic 2 said:


> I bought mine from the tubedepot $19 for 100pcs + killer USA shipping to Canada but still cheaper than buying it locally.Thanks! for the link.


 
 i got them here                                   http://www.amplifiedparts.com/products/tube_accessories?filters=Type%3DBoxes


----------



## mordy

Hi i luvemusic 2,
  
 I too, store my tubes in shoe boxes which are marked with a sticker as to content:
  

  
 Most octals I buy come without boxes (I guess since they are used). In order to remember how they sound I put a little paper with the designation, manufacturer and date and my rating of the tube (OK, VG, Excellent, Superb or NG) on the tube itself with small rubber bands. When I use the tube I pull off the paper and put it back on when switching tubes.

  
 A large rubber band is used to hold the box together with the top. If the tubes have boxes, I store them in the boxes, again with the little paper stuck on with rubber bands.

  
 If there are just a few tubes in a box I put in a piece of bubble wrap or similar to prevent the tubes from rattling around. If I need to remember a matched or near pair, I put a rubber band around both together.
  
 This system is unsophisticated but cheap, and it works. Sometimes the markings on the tube wear off, or they are very hard to read, and then the little paper comes in extra handy.
  
 Presently I am using a Dutch 1975 6DJ8/ECC88 Tektronix Amperex A-frame tube as driver and a near pair of Sylvania 6SL7GTW as power tubes. This is a very nice and sweet sounding combination.


----------



## Rossliew

Hi Mordy,
  
 Simple and effective system you have - i have started labelling my boxes as well and will move along to putting pieces of paper with notes as to its sound. Thanks for the tip!


----------



## Rossliew

Btw, anyone know if it is safe to use a CV181 as a replacement tube for the 6SN7 (which I plan to roll once my adapter and socket saver arrives) in my LD Mk 3? Read in the 6SN7 Addicts thread that it is not a direct replacement and may blow power transformers over time...


----------



## Nic Rhodes

New or old CV181s?


----------



## gibosi

rossliew said:


> Btw, anyone know if it is safe to use a CV181 as a replacement tube for the 6SN7 (which I plan to roll once my adapter and socket saver arrives) in my LD Mk 3? Read in the 6SN7 Addicts thread that it is not a direct replacement and may blow power transformers over time...


 
  
 Are you going to be using this tube as a driver? Or as power tubes? The reason Nic is asking, "new or old?" is that the new ones are electrically identical to a 6SN7 with .6A heaters, while the old ones are essentially a ECC32 and have .9A heaters. Either way, it should be safe to use either new or old CV181 as a driver or as power tubes in your LD.
  
 To use as a driver, you will need an AC to DC wall adapter putting out at a bit more than .9A at 6.3V. To use as a power tube, it is plug and play with an octal to 9-pin socket adapter, as the LD can safely use power tubes with heaters drawing up to around 1.0A per tube.


----------



## i luvmusic 2

mikelap said:


> i got them here                                   http://www.amplifiedparts.com/products/tube_accessories?filters=Type%3DBoxes


 
  
 Thanks For the link!


kvtaco17 said:


> my RCA was 25 shipped... Lol


 
 Are you refering to 6F8G?i did not see anything less than US $29 + shipping.For 6SN7 i learn how to buy cheap(Thanks to Mordy and Gibosi)most of the time i buy them by atleast a pair or more in this way it's cheaper for example i got 6 6SN7 GTA  RCA blackplate for US $45 shipped.
  


mordy said:


> Hi i luvemusic 2,
> 
> I too, store my tubes in shoe boxes which are marked with a sticker as to content:
> 
> ...


 
 I did put rubber band(2 per tube) on all of my tubes without case to prevent them from knocking each other but that did not helped.
 By labeling the tubes is a very good idea there are times that a particular tube it sound nice then i switch,when i try to find that tube can't remember which one.Thanks You!


----------



## kvtaco17

i luvemusic 2 I made an offer, it was listed at $40 and I offered $25 and he accepted! Just gotta work the system to get deals!


----------



## i luvmusic 2

kvtaco17 said:


> i luvemusic 2 I made an offer, it was listed at $40 and I offered $25 and he accepted! Just gotta work the system to get deals!


 
 Yup i wondered how did you get it that low, anyhow did you try it with your LD yet


----------



## i luvmusic 2

Time to do some electronic chassis RECYCLING for my Tube storage because i'am cheap.


----------



## kvtaco17

i luvmusic 2 said:


> Yup i wondered how did you get it that low, anyhow did you try it with your LD yet


 
 Nope the adapted is sitting at the USPS hub in St.Paul... probably another day or 2...


----------



## TrollDragon

A trio of shiny baubles arrived today.

  
 The short one appears to be all chrome.

 Hard to photograph, like a mirror behind the glass.


----------



## Rossliew

gibosi said:


> Are you going to be using this tube as a driver? Or as power tubes? The reason Nic is asking, "new or old?" is that the new ones are electrically identical to a 6SN7 with .6A heaters, while the old ones are essentially a ECC32 and have .9A heaters. Either way, it should be safe to use either new or old CV181 as a driver or as power tubes in your LD.
> 
> To use as a driver, you will need an AC to DC wall adapter putting out at a bit more than .9A at 6.3V. To use as a power tube, it is plug and play with an octal to 9-pin socket adapter, as the LD can safely use power tubes with heaters drawing up to around 1.0A per tube.


 
 Hi Gibosi / Nic, i plan on using them as plug in replacements for the stock power tubes. I have ordered the adapters and socket savers so once these arrive, i can start ordering some 6SN7s. Does this mean i can safely use both old and new CV181 tubes?
  
 On 6SN7 tubes, can I also safely use the different variants like 6SN7GTA/GTB/GTC ones? Thanks again!


----------



## gibosi

rossliew said:


> Hi Gibosi / Nic, i plan on using them as plug in replacements for the stock power tubes. I have ordered the adapters and socket savers so once these arrive, i can start ordering some 6SN7s. Does this mean i can safely use both old and new CV181 tubes?
> 
> On 6SN7 tubes, can I also safely use the different variants like 6SN7GTA/GTB/GTC ones? Thanks again!


 
  
 Yes, you can safely use both old and new CV181 tubes. And yes, you can safely use all versions of the 6SN7.
  
 Enjoy.


----------



## Rossliew

gibosi said:


> Yes, you can safely use both old and new CV181 tubes. And yes, you can safely use all versions of the 6SN7.
> 
> Enjoy.


 
 Wonderful !! Now, i need to spend more time searching...and money LOL!


----------



## kvtaco17

So damn tall this thing is...
  
  

  
 Adapter is here!
  
 Initial impressions are very good... more dynamic the anything I've tried so far.... good mids... sweet treble and well textured bass... I'll need some time to really get to know this tube and compare it to my 6SN7's.


----------



## i luvmusic 2

Oh schiit i'am SCREWED i just received my 12A(after over a month waiting for it) regulator from Chinada and i decided to unsolder the trim pot so i can install a external pot on the amp faceplate and i burnt the PCB i managed to solder a solid wire on the PCB only to find out the trace are burnt.


----------



## kvtaco17

i luvmusic 2 said:


> Oh schiit i'am SCREWED i just received my 12A(after over a month waiting for it) regulator from Chinada and i decided to unsolder the trim pot so i can install a external pot on the amp faceplate and i burnt the PCB i managed to solder a solid wire on the PCB only to find out the trace are burnt.


 
  
 That sucks! I'm sorry, it happens though when you tinker... trust me I've ruined my fair share of amps and cans...


----------



## i luvmusic 2

kvtaco17 said:


> That sucks! I'm sorry, it happens though when you tinker... trust me I've ruined my fair share of amps and cans...


 
 Will i just bought another regulator(same as the one that i screwed up)and this time no more desoldering for me or maybe for now.


----------



## i luvmusic 2

kvtaco17 said:


> So damn tall this thing is...
> 
> 
> 
> ...


 
 Now that is what you call Tower of Power.


----------



## kvtaco17

i luvmusic 2 said:


> Now that is what you call Tower of Power.


 
 Its getting out of hand... its more then a foot tall... lots of height for a little amp lol


----------



## mordy

Hi,
  
 Want to try an inexpensive and fairly unknown great driver tube? Try the 6BC8 (also known as 6BZ8 or X155) which is a dual triode in the 6DJ8 family. Balanced, sweet and detailed with laid back sound. Only con is that I have to turn up the volume more than usual.
  
 These tubes were made by all the big manufacturers, and I have Sylvania, Tung Sol, CBS, RCA and GE variants.
  
 This Sylvania 6BC8 has a nice glow with four heaters:
  
 Would be curious to know if somebody has tried this tube.
  
 I am using octals as power tubes


----------



## mordy

Big Brother has arrived - a 1976 RCA 6AS7G tube. Can it be used with the LD MKIII as a driver tube with an amplification factor of 2?
  

 Man, this tube is BIG (compare to the 6SL7 power tube in the background.). What about the show-off factor?

 Hard to get all the glowing wires into one view. Is it usable? Yes, but instead of keeping the headphone volume at 9 o'clock I have to turn it to almost max at around 4 o'clock.
First impression of sound: Hefty strong bass with a nice laid back mellow presentation with very good detail. There is a total absence of sibilance in the treble;  but no wow factor - I guess that I am a little spoiled from all the great tubes we'd tried lately. Could be that the tube needs burn in so things may change - this is only the initial impression.
  
 Patience pays off: Been looking for inexpensive 6AS7 and 6080 tubes. Finally found this tube, a bunch of 6080's + three other SN tubes. All in all 11 tubes for less than $2 each shipped from two different sellers.
  
 This tube needs a diet of 7.11V from the voltage regulator to get 6.3V at the tube pins.
  
 After listening for a while this tube is starting to grow on me (pun intended). I can "see" into the recordings and notice new micro details. The instrument separation is excellent without being artificially analytical. Have to take back what I said about the wow factor - it's just not a wow factor in your face, but, yes it's there, but more subtle.
  
 Happy tube rolling!


----------



## i luvmusic 2

mordy said:


> Big Brother has arrived - a 1976 RCA 6AS7G tube. Can it be used with the LD MKIII as a driver tube with an amplification factor of 2?
> 
> 
> Man, this tube is BIG (compare to the 6SL7 power tube in the background.). What about the show-off factor?
> ...


 
 IMO this 6AS7 tube have a bigger soundstage than any of my 6SN7's.For the MK III you are right about the volume.I used this tube most of my listening with LD 1 and Q70i.


----------



## i luvmusic 2

It's not only sound nice it looks nice too.


----------



## gibosi

mordy said:


> Big Brother has arrived - a 1976 RCA 6AS7G tube..........
> 
> Man, this tube is BIG (compare to the 6SL7 power tube in the background.)........


 
  
 Boy, I wish I had some BIG tubes! lol 
  
 At first I thought, this is backwards! The 6SL7 should be the driver and the 6AS7G should be the power tube! But now I wonder... aside from gain, does the order of the tubes, first or second, make a difference? If you could swap them, making the 6AS7G the power tube, would the "sound" be the essentially same?
  
 I hope someone will cobble together an adapter to run 6AS7's as power tubes in their LD and let us know.....


----------



## i luvmusic 2

I tried running one side  6AS7 as a power tube and the other side is 6SN7 and driver is 6SN7 and the sound is lacking in power on 6AS7 side but it's smooth sounding. As for the amp did not get warm at all i run it for 15 mins.So far i can't try running two 6AS7 power tubes because my regulator can't handle the current(i just screwed up my 12A)


----------



## i luvmusic 2

Can i used just one 6AS7 Power tube for left and right channel?


----------



## i luvmusic 2

6DJ8(Left)     6AS7          6DJ8(Right)
  
 1A                   2A                   1A
 2G                   1G                   2G 
 3K                    3K                   3K
  
 6A                    5A                  6A
 7G                    4G                  7G
 8K                   6K                   8K
 9N/C                                      9N/C
  
  
  
 Can i connect it like this?
 All heaters will be hook to external power supply.


----------



## gibosi

i luvmusic 2 said:


> Can i used just one 6AS7 Power tube for left and right channel?


 
  
 It won't work...  The LD expects to find two triodes on each side which are configured in what is called a "Push-Pull, White Cathode Follower" circuit
  
 Several weeks ago, TrollDragon addressed this exact question here:
  
 http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/5790#post_10440716


----------



## mordy

Hi Gibosi,
  
 As you mentioned, it would be nice to be able to use the 6AS7 as a power tube. The reason I use it as a driver is because I have not figured out how to use it as a power tube since it draws 2.5A and I don't know how to connect it with two separate voltage supplies.
  
 In addition to the 6AS7 tube I also got seven 1960's 6080 tubes, All RCA + one GE. Looking at the tube, the internals look very similar to the 6AS7 but in a smaller envelope. The 6080 tubes I have all look similar, except for the getters. One has a double rectangular getter, others a round or square getter. I have to admit that the coke bottle shape of the 6AS7 is very interesting and nice looking, but looks isn't everything.
  
 I have one matched pair labeled Stromberg-Carlson. I was hoping that these were Tung Sol tubes since I have seen other tubes with this name made by TS; however, these are also made by RCA.
 If you look closely you can see that the plate assembly is slanted inside the glass - doesn't seem to make a difference in performance.
  

 Stoking the fires - perhaps two of these could substitute for a room heater since they run quite hot...

  
 The sound is a little different from the 6AS7 but still similar. What first strikes me is the total lack of sibilance and the powerful bass. In fact, it seems that the bass is too powerful for my National Union 6SL7 tube used as one of the power tubes, making the the bass murky and breaking up a little. Switching to my RCA top heater wire 6SN7 tubes helped. The 6080 seems quicker and having more slam and impact than the 6AS7, but I cannot yet hear into the recording and perceive the microdynamics to the same extent as with the 6AS7.
  
 These are only initial impressions, and I need more time with this tube to form a more definite impression. The little 5A voltage regulator is working hard and the tiny heat sink is getting hot putting out 7.12V to keep the 6080 happy with the required 6.3V.
  
 If we can get the adapter issue solved (hopefully an elegant non spider web solution) we'll have a poor man's Little Dot MK9. Well, not yet, I forget that we need a protective circuit to run DC coupled amps safely.
  
 It seems to me that one of functions of power tubes is to provide ample power for the lower frequencies. Based on this I would pick strong bass performers as power tubes (think of the rhythm section in a band supporting the front players). This is not based on anything I'll read, just a hunch based on using different power tubes and noticing the differences in overall sound. Could be that I am all wrong....


----------



## i luvmusic 2

gibosi said:


> It won't work...  The LD expects to find two triodes on each side which are configured in what is called a "Push-Pull, White Cathode Follower" circuit
> 
> Several weeks ago, TrollDragon addressed this exact question here:
> 
> http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/5790#post_10440716


 
 That sucks! i was hoping it will work.Thanks G!


----------



## i luvmusic 2

Soo i fixed some of my wobbly tubes with some wood glue and water mixture it does work but one of the tube developed a channel imbalanced.I don't know where did i go wrong anyway it does work so Thank you for all the helped.


----------



## gibosi

What are the best tubes for the Little Dot?
  
 This is a question often asked in this forum, and if the person asking doesn't want to mess with 9-pin sockets, Vector test sockets, and external heater power supplies, the best we could do was suggest the 6HM5, which are not all that good compared to even a mediocre double triode.
  
 However, due to the pioneering work of Hypnos1, I now believe we can make a much stronger recommendation:
  
 C3g
  

  
 If someone doesn't want to mess with double triodes, these are "endgame" tubes. Even if they eventually decide to try double triodes, they will not find them to be better, just slightly different.
  
 Pairs of C3g are going for around $70 on eBay. And I should point out that this is what top-tier double triodes often cost. It is possible to take the black metal sheaths off, but as Siemens designed this tube to last 10,000 hours with it on, it is perfectly fine as is.
  
 A pair of adapters is needed to convert the 8-pin loctal C3g base to a the Little Dot's 7-pin 6AK5 socket. A pair will run about $40.
  

  
 http://www.ebay.com/itm/2piece-Gold-plated-C3G-TO-6AK5-tube-converter-adapter-/191424601510?rmvSB=true
  
 And finally, if one is using a stock Little Dot, the above adapters will not fit within the gold rings surrounding the driver sockets, so a pair of small spacers - "Test socket 7 pin miniature" - for about $16 will be necessary. Apparently, it is possible to remove these gold rings, and if so, these spacers are not necessary.
  

  
 http://leedsradio.com/parts-sockets.html#savers
  
 And this is the result, shown next to a nice Tung Sol 6AK5 for scale. Yes, these are BIG! But the sound is GLORIOUS! 
  

  
 To the best of my knowledge, only Lorenz and Siemens manufactured the C3g. And as best as I can tell, Telefunken and Valvo are nothing more than rebranded Siemens. So again, there are only two versions out there.
  

  
 And finally, these are 10,000 hour tubes. It is likely that the tubes will last longer than the amp! So in the end, if someone is willing to spend $130 in this way, they won't have to spend another dime on driver tubes for the life of their amp. And perhaps even more impressive, they will have an amp that can easily match amps costing considerably more.


----------



## JoeDoe

mordy said:


> Here is wiring diagram for a 12AX7 tube:
> 12AX7
> 
> 9-pin socket           left LD socket        right LD socket
> ...


 
  
 For the breadboard, since each # has 2 sockets, does it matter which one I run the wire into?


----------



## JoeDoe

Anything glaringly wrong here?


----------



## superdux

gibosi said:


> What are the best tubes for the Little Dot?
> 
> This is a question often asked in this forum, and if the person asking doesn't want to mess with 9-pin sockets, Vector socket testers, and external  heater power supplies, the best we could do was suggest the 6HM5, which are not all that good compared to even a mediocre double triode.
> 
> ...


 
  
 So i can plug these babys(C3g) with adaptor in my LDMKIII without external power supply in standard setting (MKIII as delivered)? Just asking to be absolutely sure.


----------



## gibosi

joedoe said:


> For the breadboard, since each # has 2 sockets, does it matter which one I run the wire into?


 
  
 I am not sure I understand your question....  On the breadboard socket, pins 1, 2 and 3 correspond to the plate, grid and cathode for  triode #1 and pins 6, 7 and 8 correspond to the plate, grid and cathode of triode #2. It doesn't matter if you connect triode # 1 to the left socket, as above, or to the right socket. And the same for triode # 2. The tube doesn't care.


----------



## JoeDoe

gibosi said:


> I am not sure I understand your question....  On the breadboard socket, pins 1, 2 and 3 correspond to the plate, grid and cathode for  triode #1 and pins 6, 7 and 8 correspond to the plate, grid and cathode of triode #2. It doesn't matter if you connect triode # 1 to the left socket, as above, or to the right socket. And the same for triode # 2. The tube doesn't care.


 
 Got it. I need to read up on my tube anatomy. Probably could've come to that myself if I was a bit more tube saavy...


----------



## gibosi

superdux said:


> So i can plug these babys(C3g) with adaptor in my LDMKIII without external power supply in standard setting (MKIII as delivered)? Just asking to be absolutely sure.


 
  
 Yes indeed. The C3g has .37 amp heaters, so no external heater power supply is necessary. The internal Little Dot heater supply is more than adequate. So all you need are the 8-pin loctal to 7-pin socket adapters and these tubes are "plug and play".


----------



## superdux

good, i have some money spare.If it were always as easy and relatively cheap to get to audio heaven Do you think they´ll make a good matching with my HD650s?


----------



## gibosi

superdux said:


> good, i have some money spare.If it were always as easy and relatively cheap to get to audio heaven Do you think they´ll make a good matching with my HD650s?


 
  
 I am pretty sure that Hypnos1 has HD650's, and given his enthusiasm for the C3g I have to think that are a match "made in heaven."


----------



## Gerrrsh

I recently was gifted a Little Dot I. It's got two tubes (the front pair) that are blown and I need to replace them. The front pair are 1T4 RCA tubes and the back 4 are 3A4 RCA tubes. Also, can someone please explain why it has two different voltages? What difference does it make? Is it just an audio thing or is it something to do with power?
  
 Edit: I'm very new to this level of audiophila. Before I was just a simple headphone geek.


----------



## TrollDragon

gerrrsh said:


> I recently was gifted a Little Dot I. It's got two tubes (the front pair) that are blown and I need to replace them. The front pair are 1T4 RCA tubes and the back 4 are 3A4 RCA tubes. Also, can someone please explain why it has two different voltages? What difference does it make? Is it just an audio thing or is it something to do with power?
> 
> Edit: I'm very new to this level of audiophila. Before I was just a simple headphone geek.


Now there is a vintage piece of gear, I guess it is hard to find tubes for and it runs rather hot. You might want to consider getting a newer amplifier unless you can find a source for the tubes.


www.head-fi.org/t/503046/old-possibly-original-little-dot


----------



## TrollDragon

Well I stand corrected... 
http://www.ebay.com/sch/i.html?_trksid=p2050601.m570.l1313&_nkw=1T4+tube&_sacat=0&_from=R40


----------



## mordy

Hi Joe Doe,
  
 As you mention, each terminal block has two screw posts; it does not matter which one you use. The proof that everything is connected properly is getting sound from both channels.
  
 Please be careful in touching the bare solder/wires - some voltages can go up to over 155V. Good luck!


----------



## superdux

relying on gibosi and hypnos1 judgment i just ordered some adapters(c3g to 6ak5) from china.I also could get some used C3g with these measurements:
  
 1 x Telefunken = 10,5 mA,
 1 x Siemens = 10,5 mA,
 2 x Siemens = 12,5 mA
  
 they were measured with "Funke W19" and "good" starts at 6,5mA with the Funke.
  
 do you think it'll be worth it buying those used tubes?


----------



## mordy

Hi superdux,
  
 What prices are they asking? The Funke W19 is supposed to be one of the best testers. Are these tubes from JACMusic?
  
 Are the tubes C3g or C3gS?


----------



## gibosi

superdux said:


> relying on gibosi and hypnos1 judgment i just ordered some adapters(c3g to 6ak5) from china.I also could get some used C3g with these measurements:
> 
> 1 x Telefunken = 10,5 mA,
> 1 x Siemens = 10,5 mA,
> ...


 
  
 Again, these are 10,000 hour tubes. They should have lots of life yet in them. Enjoy.


----------



## mordy

Hi Gibosi,
  
 Could you elaborate on double triodes that you feel are equal to but different from the C3g tubes? The cheapest I could found a pair of the C3g tubes was $70 incl shipping.


----------



## gibosi

mordy said:


> Are the tubes C3g or C3gS?


 
  
 From this site:
  
 http://www.radiomuseum.org/tubes/tube_c3gs.html
  
 "In case the final factory-tests of a C3g revealed a transconductance equal or higher than 105% of the nominal value ( 14000 µmhos), these tubes were marked with the suffix /s."
  
 So the C3gs appears to be nothing more than a C3g that was measured at the factory and found to have a slightly higher transconductance value than the design spec. In my opinion it is probably not worth spending a lot more for these......


----------



## superdux

mordy said:


> Hi superdux,
> 
> What prices are they asking? The Funke W19 is supposed to be one of the best testers. Are these tubes from JACMusic?
> 
> Are the tubes C3g or C3gS?


 

 hi this is an auction(not from JACMusic) and i'm planning on not going to high with my bid cos of "onion leather" in my wallet.But i'd be willing to forward 2 of these if i win the auction for auctioning price and postage.They are C3g.
  
 EDIT: sorry folks, i've found someone from Europe who is willing to take the 2 tubes from me.


----------



## gibosi

mordy said:


> Hi Gibosi,
> 
> Could you elaborate on double triodes that you feel are equal to but different from the C3g tubes? The cheapest I could found a pair of the C3g tubes was $70 incl shipping.


 
  
 Well, of course this is all very subjective... My current favorites are Sylvania 6SN7W, both short and tall bottle, Fivre 6SN7GT, National Union gray glass 6SN7GT, Heerlen- or Eindhoven-made E80CC and 1975 Voskhod 6N23P. If you can find them, the Voskhods are probably the cheapest of these, but in my experience, when purchasing from Ukraine and Russia, I never really know what I am going to get before they arrive.... I believe you have a '74? I find it to sound virtually the same as the '75.
  
 I am very poor at comparing tubes... I don't have the discipline or the ears for it.... But I can say that in my mind, these are all top-tier tubes, they are all very, very close, with only very subtle differences. One might be a bit more forward, one might be a little more warm, one might have a bit more bass detail, and so on.... I could be happy with any of them long term.


----------



## gibosi

And I thought I should remind those who have a 9-pin breadboard socket and Vectors, that it is easy to roll C3g's too. Just be very sure you do not have a tube plugged into your 9-pin socket at the same time!


----------



## JoeDoe

gibosi said:


> And I thought I should remind those who have a 9-pin breadboard socket and Vectors, that it is easy to roll C3g's too. Just be very sure you do not have a tube plugged into your 9-pin socket at the same time!




Good to know!


----------



## mordy

Hi Gibosi,
  
 Thanks for your answer - made me feel better. Yes, I have four 1974 6N23P tubes that cost me $4 each shipped. I had trouble communicating to the seller the year I wanted until I used Google translate.
  
 Now I am listening to another bargain tube, the GE 1954 12SL7GT which cost me less than $2 each in a lot of four tubes (3 GEs and and a Coke Bottle 6AS7 RCA). Nice, brassy rich sound.

  

  
 I have been looking for the 12SX7 tube (a premium version of the 12SN7) that Nic Rhodes recommended, but can only find it for around $20, so I took a chance on this tube. Seems that GE made fine tubes in the 50's, and this one does not disappoint. Somehow I have the preconceived idea that silver plate does not sound good (based on some 6AK5 tubes with silver plate), but this one is sounding very good.


----------



## mordy

If I used two loctal breadboards with the Vectors, could I skip the adapters? This would shave off half the price of the $60 adapters.


----------



## gibosi

mordy said:


> If I used two loctal breadboards with the Vectors, could I skip the adapters? This would shave off half the price of the $60 adapters.


 
  
 You sure can! I was thinking about doing this, but I just don't have enough room on my desk. With a couple of loctal breadboard sockets, you can connect G3 to the Cathode and G2 to the Plate using the compression terminal blocks and then you will have two nice pentode-strapped triodes.


----------



## gibosi

gibosi said:


> You sure can! I was thinking about doing this, but I just don't have enough room on my desk. With a couple of loctal breadboard sockets, you can connect G3 to the Cathode and G2 to the Plate using the compression terminal blocks and then you will have two nice pentode-strapped triodes.


 
  
 Purchase two 8-pin breadboard loctal sockets for the C3g's. In each socket, tie pins 2 and 5 together, which straps Grid 3 to the Cathode. Tie pins 3 and 4 together, which straps Grid 2 to the Plate. Route pins 3 (Plate), 5 (Cathode) and 6 (Grid) in each of the two sockets to the corresponding pins in the two Vectors. And finally, hook up your heaters, either through the Vectors or an external heater PS.  This done, the C3g's are very properly strapped, per the textbook. as triodes, and "plugged" into the LD.
  
 8-pin loctal                                    Vector
  
 1 Heater                                         3 (or external PS) 
 2 Grid #3 to pin 5 in socket
 3 Plate                                           5       
 4 Grid #2 to pin 3 in socket
 5 Cathode                                       2
 6 Grid #1                                        1
 7 Cathode 
 8 Heater                                         4  (or external PS) 
  
 (It is not necessary to tie pins 5 and 7 together, as they are already tied together inside the tube)


----------



## hypnos1

i luvmusic 2 said:


> I tried running one side  6AS7 as a power tube and the other side is 6SN7 and driver is 6SN7 and the sound is lacking in power on 6AS7 side but it's smooth sounding. As for the amp did not get warm at all i run it for 15 mins.So far i can't try running two 6AS7 power tubes because my regulator can't handle the current(i just screwed up my 12A)


 
  
 Hi ilm2.
  
 Just back from my hols and I notice you've beaten me to it re. 6AS7 as power tube...WELL DONE! With low amplification factor, we will certainly need to be using 2 of same.
  
 I'm glad your amp has not gone up in flames...gives me more confidence to continue with the experiment. However, even though you say the amp did not get warm, I have a horrible feeling things could go drastically wrong at almost any time...I would have thought a resistor could reach critical point with little warning as regards obvious external overheating (perhaps I'm being my usual over-anxious self!). Therefore, just to be extra sure I will be removing the front panel of my MKIV SE and be using a temperature probe - VERY CAREFULLY! - to keep an eye on things. Hopefully this may give a somewhat higher level of reassurance...(w_hen_ I've managed to get everything sorted back in the house and garden, that is - holidays make a lot of work!!).
  


superdux said:


> good, i have some money spare.If it were always as easy and relatively cheap to get to audio heaven Do you think they´ll make a good matching with my HD650s?


 
  
 Hi superdux.
  
 In a word - or rather *2* - YOU BET! I never thought I would get such a sound from my 650s...truly a match made in heaven...
 I do hope you managed to get those C3Gs...as gibosi said, it is not worth paying a great deal more for the 'S's, but I have to admit my pair did have the edge over the standard tubes...so if they can be found for not _too_ much more, they are certainly worth the extra.
  
 Good luck.


----------



## superdux

thats great hypnos1, i´m already eager as how the C3g will sound from my setup! But the delivery of the adapters will take a few weeks from China if they don´t also get stuck in customs too, as stuff usually does that i order from China.
  
 Also i'm happy to say that i was highest bidder on the 4 used c3g's and it was a reasonable price.Someone from this board is also inclined to make joint effort and i will forward 2 tubes to him.
  
 Thats what i like about this board, as i have met members that trusted me and sent items before me being able to pay as i'm usually broke.
 Tubes and adapters have cost me approx. ~250Euros so far and i plan to put an end to spending after i have the c3g's.My brother always laughs at me when i tell him i want to put my bank account back to black numbers.


----------



## i luvmusic 2

hypnos1 said:


> Hi ilm2.
> 
> Just back from my hols and I notice you've beaten me to it re. 6AS7 as power tube...WELL DONE! With low amplification factor, we will certainly need to be using 2 of same.
> 
> ...


 
 I tried mine with 1 6AS7(Driver Tube) so your expirement would different from what i did take extra caution.I would love to try 2 6AS7 power tube but that would take sometime i'am still waiting for my 12A regulator.I'am tempted to get those C3Gs but in few months i will be backhome then i will get the Bottlehead Crack and i know that the 6SN7 will work with Crack so i'm OK with that but for C3Gs i'm not sure if it's compatible with crack.


----------



## gibosi

i luvmusic 2 said:


> ......I'am tempted to get those C3Gs but in few months i will be backhome then i will get the Bottlehead Crack and i know that the 6SN7 will work with Crack so i'm OK with that but for C3Gs i'm not sure if it's compatible with crack.


 
  
 We don't know... The Crack's default driver is a 12AU7 configured in 6-volt mode. C3g's are pentodes, so you would need to build an adapter to convert them to triodes and connect them to the 12AU7 socket. But this is just "sockets and wires" and we know how to do that. What we don't know is if triode-strapped C3g's have too much gain.
  
 I have read that 12AT7's with a gain of around 70 and 12AX7's with a gain of around 100 will not work in the Crack. Too much gain. The gain of the 12AU7 is about 20, about the same as the 6SN7. I have read that folks have had good success running 6DJ8's, with a gain of 33, in the Crack. So I think we know that tubes with a gain between 20 and 33 are compatible with the Crack.
  
 I believe a triode-strapped C3g has a gain of around 40. This is twice as high as the tube the Crack was designed around, the 12AU7. So the C3g might have too much gain for the Crack.... or it might just be fine.....
  
 When you get your Crack, I hope you will give them a try and tell us how the sound.


----------



## superdux

I'm not sure if already mentioned, but there are 3 versions of C3g:
  
 the C3g with 8 pins (those must be the ones we can use for our LD's)
  
 http://www.radiomuseum.org/tubes/tube_c3g.html
  
 the C3g new with pin 5 missing
  
 http://www.radiomuseum.org/tubes/tube_c3g_newi.html
  
 and the C3g old with 9 pins and no serial fabrication.
  
 http://www.radiomuseum.org/tubes/tube_c3g_old.html
  
 sorry, the links are all in German, but you can see the mapping of the pins.
  
 I guess there could be problems if you plugin the C3g new into a adapter?
  


> Pentode for wide-band amplifiers (PTT)from SN 10001 onwards with a different base diagramme in respect to *C3g_new*.
> 
> Important Note:
> Already in WWII a pentode named C3g was developed. We call it *C3g_old*.
> ...


----------



## gibosi

I did not know about these other versions! And yes, if one was to obtain these other versions, it would be necessary to rewire the socket, and for the C3g_old, the heater voltage is 18 volts, instead of 6.3. However, I would guess that these earlier versions are very rare and probably don't turn up very often. I know that I have never seen them.... But for sure, it is good to know that they exist.
  
 Thanks!


----------



## superdux

you´re right gibosi, the other versions had either a serial number from 501 to 10000 and the second one didn´t go into mass production.
 btw. i contacted the seller of those adapters and he has added 2 extra fotos to his auction where you can see a different socket from the one initially presented and he can only deliver them atm.
  
 see ebay auction nr.:301131714830


----------



## mordy

If you look on the German EBay, you can find C3m tubes from 1941:
  
 http://www.ebay.de/itm/R208-Siemens-C3m-Hochfrequenz-Verstarker-Pentode-ca-1941/160715042053?_trksid=p2047675.c100005.m1851&_trkparms=aid%3D222003%26algo%3DSIC.FIT%26ao%3D1%26asc%3D22325%26meid%3D6699380015620457391%26pid%3D100005%26prg%3D9704%26rk%3D2%26rkt%3D6%26sd%3D160715036259&rt=nc
  
 There are several offers for Siemens and Lorenz tubes.


----------



## TrollDragon

Here is a great tip for posting eBay links, I'll use mordy's link as an example.

If you chop off everything from the "?" back it gets rid of all the eBay tracking / referral stuff.

www.ebay.de/itm/R208-Siemens-C3m-Hochfrequenz-Verstarker-Pentode-ca-1941/160715042053

Much cleaner link and no nosey foolishness attached.


----------



## hypnos1

superdux said:


> thats great hypnos1, i´m already eager as how the C3g will sound from my setup! But the delivery of the adapters will take a few weeks from China if they don´t also get stuck in customs too, as stuff usually does that i order from China.
> 
> Also i'm happy to say that i was highest bidder on the 4 used c3g's and it was a reasonable price.Someone from this board is also inclined to make joint effort and i will forward 2 tubes to him.
> 
> ...


 
  
 Hi again superdux.
  
 I think I am fairly safe in saying that once you hear what the C3gs can deliver, you will feel quite happy "putting an end to spending"...BUT - what about the power tubes?! I am currently listening to some of my favourite music - Clannad's 'Past Present' (Irish progressive acoustic/electronic folk) - and after just 2 weeks' absence I had almost forgotten how mind-blowing is the combination of MKIV SE/C3gSs/Psvane CV181 TII & Tung Sol 7N7/HD650s...I simply cannot imagine anything bettering what is entering my ears and brain...AWESOME!! (Why am I even contemplating the 6AS7s as power tube experiment? - I haven't a clue!!...yes I have : it's called tube-rolling mania/addiction! Heaven help us, lol
	

	
	
		
		

		
			




  
 I look forward to your impressions when those adapters _finally_ arrive...you have my sympathies re the long wait! Patience mon ami/mein freund/amico mio...


superdux said:


> I'm not sure if already mentioned, but there are 3 versions of C3g:
> 
> the C3g with 8 pins (those must be the ones we can use for our LD's)
> 
> ...


 
  
 Wow! I never knew that...well found, superdux.
  
 Yo, it's the 8-pin version we certainly need...
  
 As for the 'S' version being merely one with higher transconductance, I am wondering why the top of the S's tube is slightly flatter than the standard tube? Ah well, the wonderful vagaries of tube land!


----------



## i luvmusic 2

gibosi said:


> We don't know... The Crack's default driver is a 12AU7 configured in 6-volt mode. C3g's are pentodes, so you would need to build an adapter to convert them to triodes and connect them to the 12AU7 socket. But this is just "sockets and wires" and we know how to do that. What we don't know is if triode-strapped C3g's have too much gain.
> 
> I have read that 12AT7's with a gain of around 70 and 12AX7's with a gain of around 100 will not work in the Crack. Too much gain. The gain of the 12AU7 is about 20, about the same as the 6SN7. I have read that folks have had good success running 6DJ8's, with a gain of 33, in the Crack. So I think we know that tubes with a gain between 20 and 33 are compatible with the Crack.
> 
> ...


 
 In that case i'm not jumping into C3g wagon i will wait until i get my crack then get some nice 6AS7/6080 tubes because i know i can used these tubes with my LD amps.


----------



## i luvmusic 2

Thanks for the info G!


----------



## Rossliew

I can barely keep up with all your different tube configurations!
  
 On another note, can anyone share experience of the Little Dot I+ paired with an LCD-XC? or perhaps another LD model which is more suitable to drive the planars? Many thanks!


----------



## TrollDragon

rossliew said:


> I can barely keep up with all your different tube configurations!
> 
> On another note, can anyone share experience of the Little Dot I+ paired with an LCD-XC? or perhaps another LD model which is more suitable to drive the planars? Many thanks!


I ran the LCD-3's with the MK IV for a few weeks on the Burson Loaner program and really enjoyed the sound from the Audeze's with the tubes, my only comparison was the DT880's and the LCD-3's do everything in spades compared to the beyers.

The MK IV had plenty of power compared to the Conductor SL's 2 watts of output, I didn't find it lacking in drive power by any means. I even ran the LCD-3's from my FiiO E09K with good results.

I miss the Audeze's, incredible sound and plush earpads.


----------



## gibosi

According to Audeze's website, the LCD-3 has an impedance of 110 ohms, whereas the LCD-XC has an impedance of 22 ohms. I doubt that the LD II, III or IV, being OTL tube amps, would be able to drive the low-impedence LDC-XC very well. On the other hand, the LD1+ was specifically designed to drive low impedance headphones. So in my opinion, the LD1+ would be best for the LCD-XC. On the other hand, any of the Little Dots would be a good match for the LCD-3.


----------



## Rossliew

Thanks, guys.
  
 I actually tried the Mk III with the XC and it sounded OK just lacking body. I suppose the I+ would be good, maybe even the VI+?


----------



## Androb

rossliew said:


> Thanks, guys.
> 
> I actually tried the Mk III with the XC and it sounded OK just lacking body. I suppose the I+ would be good, maybe even the VI+?


 I got both MK3 and MKVI+ at home and wouldn't recommend MK3, it lacks power. The mkvi+ in fully balanced tho is awesome!


----------



## Rossliew

androb said:


> I got both MK3 and MKVI+ at home and wouldn't recommend MK3, it lacks power. The mkvi+ in fully balanced tho is awesome!


 
 From the description on the LD site, it would seem the VI+ is tuned towards lower impedance headphones. Mk 3 is definitely for higher impedance loads and possibly Grados being the exception.
  
 How's the bass response with the VI+? Which headphones do you pair it with?


----------



## Androb

rossliew said:


> From the description on the LD site, it would seem the VI+ is tuned towards lower impedance headphones. Mk 3 is definitely for higher impedance loads and possibly Grados being the exception.
> 
> How's the bass response with the VI+? Which headphones do you pair it with?


Lcd-3 and hd650 both balanced cables! I think it's a really nice pairing, everything is fine!


----------



## Rossliew

androb said:


> Lcd-3 and hd650 both balanced cables! I think it's a really nice pairing, everything is fine!


 
 With the XC being relatively more sensitive, i hope they would sound good too...choices, choices..


----------



## Androb

rossliew said:


> With the XC being relatively more sensitive, i hope they would sound good too...choices, choices..


I think they prolly will. When I asked david what amp to get he told me to get this one, as I use many differeny headphones. Most stuff sounds really nice with it, except if you have sensitive headphones with 1/4 plug since then it will be noisy.


----------



## Rossliew

androb said:


> I think they prolly will. When I asked david what amp to get he told me to get this one, as I use many differeny headphones. Most stuff sounds really nice with it, except if you have sensitive headphones with 1/4 plug since then it will be noisy.


 
 David suggested the I+ for the XC but i thought  a balanced topology might benefit it more..


----------



## Androb

rossliew said:


> David suggested the I+ for the XC but i thought  a balanced topology might benefit it more..


Oh, well I haven't heard that one so it might be possible  But yea, balanced is killer!


----------



## superdux

just to let you know: the chinese seller deducted total shipping for 4pieces C3G to 6AK5 Adapter.


----------



## gibosi

As I have been suffering from "BIG Tube Envy" for some time now, I decided to put an end to the agony and buy one! lol
  
 A nice Tung-Sol 2399 (AKA 5998), which is very similar to the 6AS7, but with slightly electrical characteristics and "domino" plates. At this time, I am waiting for a more powerful AC adapter and a suitable voltage regulator to arrive so I can give it a try. And even if it is not up to par as a "driver" in my LD, it will most certainly make a very fine power tube when the day comes that I get an OTL amp.


----------



## i luvmusic 2

gibosi said:


> As I have been suffering from "BIG Tube Envy" for some time now, I decided to put an end to the agony and buy one! lol
> 
> A nice Tung-Sol 2399 (AKA 5998), which is very similar to the 6AS7, but with slightly electrical characteristics and "domino" plates. At this time, I am waiting for a more powerful AC adapter and a suitable voltage regulator to arrive so I can give it a try. And even if it is not up to par as a "driver" in my LD, it will most certainly make a very fine power tube when the day comes that I get an OTL amp.


 
 I think you will like that  tube with your LD 1+ i enjoyed my 6AS7 with my LD 1+ i may need to turn the volume knob a bit higher than my usual listening level but the detail with the 6AS7 is amazing IMO.


----------



## CITIZENLIN

Hi
  
 Currently I am enjoying 6DT6A and 5915. I've tried 6AU6A, 6485. My like to know If 6HM5 will be improvement over 6DT6A or 5915 before I jump on C3G option. Which is way over my budget for now. Thank you.


----------



## gibosi

citizenlin said:


> Currently I am enjoying 6DT6A and 5915. I've tried 6AU6A, 6485. My like to know If 6HM5 will be improvement over 6DT6A or 5915 before I jump on C3G option. Which is way over my budget for now. Thank you.


 
  
 It has been a long time since I have listened to these tubes... But to the best of my recollection, the 6HM5 offers a more 3-D sound stage with better imaging.... But again, it has been a long time....


----------



## kvtaco17

citizenlin said:


> Hi
> 
> Currently I am enjoying 6DT6A and 5915. I've tried 6AU6A, 6485. My like to know If 6HM5 will be improvement over 6DT6A or 5915 before I jump on C3G option. Which is way over my budget for now. Thank you.


 
 The imaging is much better BUT I found the 6HM5's to have less warmth, so it may come down to personal preference.


----------



## CITIZENLIN

Thanks gibosi.
  
 I've been reading quietly for last 3 weeks . My head is spinning trying to get it all in. On 6HM5, short ones are not recommended . Should I just get russian 6HM5? Which are 6.99 with free shipping for each.
  
 Thank you


----------



## gibosi

citizenlin said:


> Thanks gibosi.
> 
> I've been reading quietly for last 3 weeks . My head is spinning trying to get it all in. On 6HM5, short ones are not recommended . Should I just get russian 6HM5? Which are 6.99 with free shipping for each.
> 
> Thank you


 
  
 Russian? I don't think I have ever seen a Russian 6HM5....  I have tried and liked the GE's. And others here have tried and liked the Sylvania and the EI (made in Yugoslavia).


----------



## CITIZENLIN

My bad , I meant EI Yugoslavia. GE or EI ?


----------



## mordy

Hi CITIZENLIN,
  
 Several people tried this tube and liked it.
  
 http://www.ebay.com/itm/6HM5-6HA5-EC900-export-quality-audio-triode-tube-NOS-FREE-SHIPPING-/300879467071?pt=Vintage_Electronics_R2&hash=item460dd0523f
  
 When I bought a pair the seller accepted $5 each shipped - try it.  This tube was made by Ei in Yugoslavia. When it starts up there may be a flash of light, but it is nothing to worry about - just a quick start feature.


----------



## mordy

Hi Gibosi,
  
 Received a lot of seven 6080 tubes. They are from different years; all but one of them is made by RCA, the other one is a GE. They sound different, perhaps because of slightly different construction and usage.
  
 The best of these, a 1956 and 1960 RCA and the GE, sound very good with a very strong punchy bass which pairs very well with my Audio Technica headphones which are bass shy.
  
 In comparison to my Coke Bottle 1976 RCA 6AS7G tube the 6080's have better bass, but the 6AS7 has more detail. These 6080 tubes also play louder than the 6AS7 although both have an amplification factor of 2.
  
 At this time the nod goes to the 6080. However, what I really would want to do is to use these 6080s as power tubes, but I haven't figured out how to do it. Perhaps buying two octal breadboards and two 9-pin socket extenders. Then use solid 18 gauge insulated copper wire (which is the same thickness as the tube pins) and connect the wires to screw terminals on each breadboard. The other end of the wire I could just strip and push down into the socket extender.
  
 Two separate wires would go to an external power supply rated 10A. Do I need two external power supplies, or would one do? The 6080 tubes draw 2.5A each.


----------



## gibosi

citizenlin said:


> My bad , I meant EI Yugoslavia. GE or EI ?


 
  
 Unfortunately, I tried the GE, but didn't try the EI, so I really can't say which....  But as cheap as these are, why not try both?


----------



## CITIZENLIN

gibosi said:


> Unfortunately, I tried the GE, but didn't try the EI, so I really can't say which....  But as cheap as these are, why not try both?


 

 haha you are right but I am trying to save money for C3G setup. You know adapters so expensive.
  
  
  


mordy said:


> Hi CITIZENLIN,
> 
> Several people tried this tube and liked it.
> 
> ...


 
  Thank you mordy. I think I will try those (EI). 
  
 Thank you guys. Without you guys, I would've been still playing stock set up on my MK IV. Then again thank you very much for letting spent ton of mula.


----------



## gibosi

mordy said:


> Two separate wires would go to an external power supply rated 10A. Do I need two external power supplies, or would one do? The 6080 tubes draw 2.5A each.


 
  
 Probably you would need two external power supplies.... The reason I say this is I haven't seen a cheap voltage regulator that I am confident is good for 5A. All those I have seen that are labeled 5A add something like "Recommended for use in the 4.5A". So I am not sure it is a good idea to try to draw 5A through one of the these.
  
 Similarly, I have been thinking about running a Cetron JAN 6336B in my LD1+. However, this is a 5A tube. And I just don't know how to interpret "Output current: 0-5A. Recommended for use in the 4.5A."


----------



## Rossliew

Is the 6hm5 a direct plug and play?


----------



## gibosi

rossliew said:


> Is the 6hm5 a direct plug and play?


 
  
 Yes it is. Set your LD for EF95 tubes and it is plug and play.


----------



## Rossliew

gibosi said:


> Yes it is. Set your LD for EF95 tubes and it is plug and play.




Cheers! I ordered a pair and realized it might not be a direct plug in Lol!


----------



## mordy

Hi,
  
 I was intrigued by the subminiature frame grid dual triode tubes that supposedly were the pinnacle of tube development. Once Gibosi showed us how you can use them connected to a breadboard I decided to take the plunge. These tubes are supposed to be strong enough to withstand nuclear radiation and survive tremendous vibration and G forces.
  
 Found a deal on an unknown dual triode Raytheon JAN 6832 from 1957 with characteristics similar to the 6SN7 tubes. Paid $7 shipped for a pair (received three). [I believe this offer is still available if you want to try them.]  My retired engineer friend helped me to solder little 18 gauge solid copper insulated wires onto the leads. These copper wires are the same thickness as the socket holes in the LD amp. Gibosi provided the wiring diagram and instructions how to connect the little octopus thing.
  
 I used little plastic pin protectors that came with Mullard tubes as a numbering guide, putting a sticker on the perimeter and marking the leads 1-7 (I know, there are eight leads, but I'll leave it to you to figure out). No external power supply is needed since these tubes work on the standard 6.3V and draw 0.4A. To keep things solderless I used cable ties to keep the wires more or less in place.Here is a picture comparing the size of a 6AS7 with the 6832:
  
 Here is a work in progress - the experimental setup using the Vectors (disconnected from the breadboards). It looks like a dangerous spider web. What is left is to insulate the wires in case they end up touching each other. My engineer friend suggested nail polish on the bare wires. I am going to ask one of my grand daughters for a color they don't use any more, green, purple, black or whatever....
 I do not have any humming problem unless I turn up the volume too high which is the same as with most tubes I use.
  

  
 Now, after having all this fun and brain and finger exercises, comes the best part - this sub miniature dual triode sounds excellent. Powered by a near pair of RCA 6SN7GTB tubes this 5837 has punchy solid bass and great extended highs and a balanced, detailed, coherent, and lively presentation right out of the bubble wrap. (No boxes and no markings on the tube.)
  
 The frame grid construction is said to use wires that are so thin that the naked eye cannot see them. The prized 6DJ8 tubes are also said to use frame grid construction. Perhaps this has to do with the excellent sound.
  
 My set up seems very fragile so I think that I have to limit my toe tapping LOL.
  
 Happy tube rolling!


----------



## i luvmusic 2

mordy said:


> Hi,
> 
> I was intrigued by the subminiature frame grid dual triode tubes that supposedly were the pinnacle of tube development. Once Gibosi showed us how you can use them connected to a breadboard I decided to take the plunge. These tubes are supposed to be strong enough to withstand nuclear radiation and survive tremendous vibration and G forces.
> 
> ...


 
  lucky you the last time i checked that tube on 3bay it was $29+ killer shipping.


----------



## gibosi

i luvmusic 2 said:


> lucky you the last time i checked that tube on 3bay it was $29+ killer shipping.


 
  
 Mordy is using a different sub-miniature than the one I used. The one I used, Sylvania 7963, is expensive, over $20. But he is using a Raytheon 6832. and these are much cheaper. For example:
  
 http://www.ebay.com/itm/Raytheon-Jan-6832-Submini-dual-Triode-Matched-Pair-Excellent-NOS-tubes-/271171966719


----------



## i luvmusic 2

I'm  bidding on 3 RCA 6AS7G i hope i can get this one i really want this,preparing for my future CRACK not only that i can still use this tubes with my LD's.


----------



## i luvmusic 2

gibosi said:


> Mordy is using a different sub-miniature than the one I used. The one I used, Sylvania 7963, is expensive, over $20. But he is using a Raytheon 6832. and these are much cheaper. For example:
> 
> http://www.ebay.com/itm/Raytheon-Jan-6832-Submini-dual-Triode-Matched-Pair-Excellent-NOS-tubes-/271171966719


 
 Thanks G! i just bought it from your link.


----------



## hypnos1

mordy said:


> Hi Gibosi,
> 
> Received a lot of seven 6080 tubes. They are from different years; all but one of them is made by RCA, the other one is a GE. They sound different, perhaps because of slightly different construction and usage.
> 
> ...


 
  
 Right then folks, here we go - at last! - the 6AS7G as power tube (only 1, in the right channel at the moment, with the Psvane CV181-T II in the left).
  
 Well, all I can say at the moment is...WOW! I wasn't really expecting anything could outdo the TS 7N7 in my setup, but after about half an hour (I believe these tube types need a fair warm-up) I just could not believe it...initial impressions were greater dynamics, more detail especially in the upper bass/lower mids, and an even more expansive soundstage (assisted in my Clannad tracks by more of the reverb). A much more intensive listening appraisal will have to wait I'm afraid - peering into the MKIV SE's innards, while holding the temperature probe hard against the cathode resistor and watching the temp readout with much trepidation was NOT very conducive to proper sound assessment, lol!!
  
 Anyway, much to my great relief the temperature didn't do heart-stopping jumps, but a gradual rise to 56/57C after an hour's continuous playing (the 6SN7-types held at 28C).
 Better still, it stayed there after 2 hours; then just 58C at 3 hours, and 59C at 4 hours. As I believe this is way below the maximum rated temp for such a resistor, it looks as though we may be OK with these tubes after all...if so, I think this could  be just as  great a leap for our LDs (the MKIV SE, anyways) as was given by the C3g drivers. I am over the moon - at present at least! The prospect of *BOTH* RCAs up and running is getting me all of a lather
	

	
	
		
		

		
		
	


	




.
  
 As for setup, mordy, I am using a 6SN7 to 6C7G adapter, with pins 4 & 5 of the latter chopped off, all bar enough to solder the external heater wires (then covered with tape, of course).
 I managed to find a voltage regulator rated at 8A, which at the moment with just 1 tube is working fine - no real heat from it even after 4 hours' use. It is on amazon.com for $10.96 (free shipping), and .co.uk for £4.99 (free UK shipping). It is listed as "Input AC/DC 12-45V to Output AC/DC 0.7-21V 8A converter board step-down voltage regulator module"... It has no readout, so you do need a meter, which is good for checking the _actual_ figure at the pin anyway. And the power is via an old laptop supply.
 With my IV SE I don't need the socket extenders (thank God!) - I just remove all the brass bits...
  
 And so at the moment, my rig is looking like this :
  

  
 .....and sounding like...
	

	
	
		
		

		
		
	


	



  
  
  


gibosi said:


> Probably you would need two external power supplies.... The reason I say this is I haven't seen a cheap voltage regulator that I am confident is good for 5A. All those I have seen that are labeled 5A add something like "Recommended for use in the 4.5A". So I am not sure it is a good idea to try to draw 5A through one of the these.
> 
> Similarly, I have been thinking about running a Cetron JAN 6336B in my LD1+. However, this is a 5A tube. And I just don't know how to interpret "Output current: 0-5A. Recommended for use in the 4.5A."


 
  
  
 Hi g,
  
 As I mentioned above, I think I have found a regulator that can deliver, minus the readout that is.
  
 As for the 6336B, have you checked ALL the tube data? I thought it was one mighty job to match OK....


----------



## i luvmusic 2

hypnos1 said:


> Right then folks, here we go - at last! - the 6AS7G as power tube (only 1, in the right channel at the moment, with the Psvane CV181-T II in the left).
> 
> Well, all I can say at the moment is...WOW! I wasn't really expecting anything could outdo the TS 7N7 in my setup, but after about half an hour (I believe these tube types need a fair warm-up) I just could not believe it...initial impressions were greater dynamics, more detail especially in the upper bass/lower mids, and an even more expansive soundstage (assisted in my Clannad tracks by more of the reverb). A much more intensive listening appraisal will have to wait I'm afraid - peering into the MKIV SE's innards, while holding the temperature probe hard against the cathode resistor and watching the temp readout with much trepidation was NOT very conducive to proper sound assessment, lol!!
> 
> ...


 
 Finally that is what i been waiting for 6AS7 Power Tubes if only my 12A regulator is here danm speedboat.


----------



## gibosi

hypnos1 said:


> As for the 6336B, have you checked ALL the tube data? I thought it was one mighty job to match OK....


 
  
 Great work! So it does seem that the LD's can handle 6AS7-types with relative ease. 
  
 And yes indeed, the 6336B is quite a tube. Some have described it as equivalent to two 6AS7's in one bottle! While I have no real plans to run the 6336B in my LD, I wanted to make sure that I could provide 5A if I ever become crazy enough to try. lol


----------



## MIKELAP

i luvmusic 2 said:


> I'm  bidding on 3 RCA 6AS7G i hope i can get this one i really want this,preparing for my future CRACK not only that i can still use this tubes with my LD's.


 
 Did they just sell for $26.00 if so i just won that auction sorry man


----------



## i luvmusic 2

mikelap said:


> Did they sell for $26.00


 
 Don't tell me you got them yes they are.


----------



## MIKELAP

i luvmusic 2 said:


> Don't tell me you got them yes they are.


 
 Lol ill have to move i guess


----------



## i luvmusic 2

mikelap said:


> Did they just sell for $26.00 if so i just won that auction sorry man


 
 No worries but if you want to sell one PM me thanks!


----------



## i luvmusic 2

mikelap said:


> Lol ill have to move i guess


 
 At one point during the auction i bet 28 then back it down to 24 then it's done.Lucky You!


----------



## i luvmusic 2

I guess better luck next time


----------



## MIKELAP

i luvmusic 2 said:


> At one point during the auction i bet 28 then back it down to 24 then it's done.Lucky You!


 
 My maximum was $37.00


----------



## i luvmusic 2

mikelap said:


> My maximum was $37.00


 
 Will i did not go that high....


----------



## i luvmusic 2

Finally i received my 12A regulator last night and started using it with my desktop power supply(12V-15A)and 6AS7 power tubes for Ld MK III and i noticed a fire hazard.Cable 4feet 18awg stranded is not enough to supply 7V-6.2A(as per my crappy multi meter).The cable it gets very soft and hot it nearly  burnt on me luckily i  noticed the burning smell  and when i grabbed it man it's that hot then i replaced it with 16awg and it's fine now.The 12A regulator it gets really hot as well so my guess is i'am screwed for the other two 7.5A regulator that i ordered it looks like i can't used just one of those 7A regulator to supply 6AS7 Power tubes and 6SN7 driver tube.


----------



## gibosi

i luvmusic 2 said:


> Finally i received my 12A regulator last night and started using it with my desktop power supply(12V-15A)and 6AS7 power tubes for Ld MK III...


 
  
 This is your LD MKIII? I think you have stuffed it into another enclosure? But in the picture, I am seeing 8 tubes!


----------



## i luvmusic 2

No it's the LD 1 in the case the other tubes are for MK III as you can see in the picture i have the 6AS7 side by side that is the power tube  and on the right back  tube is the driver adapter for MK III on the left back tube is for the LD 1 and the front tubes are adapters for 12A.. 6DJ8 and driver tube for LD 1 because i can't access it anymore MK III is beside the adapter and i have a terminal block behind to connect what ever adapter i need  or which amp to connect it to.I was going to put the Mk III with the LD 1 but i don't have enough room in that chassis plus it's going to be a pain  in the butt for me to take these amps with me on my way back home.I don't know if i'am allowed to fly with these type of electronics or i just shipped them out back home.


----------



## i luvmusic 2

i luvmusic 2 said:


> Finally i received my 12A regulator last night and started using it with my desktop power supply(12V-15A)and 6AS7 power tubes for Ld MK III and i noticed a fire hazard.Cable 4feet 18awg stranded is not enough to supply 7V-6.2A(as per my crappy multi meter).The cable it gets very soft and hot it nearly  burnt on me luckily i  noticed the burning smell  and when i grabbed it man it's that hot then i replaced it with 16awg and it's fine now.The 12A regulator it gets really hot as well so my guess is i'am screwed for the other two 7.5A regulator that i ordered it looks like i can't used just one of those 7A regulator to supply 6AS7 Power tubes and 6SN7 driver tube.


 
 Correction the cable i've used is actually 20awg speaker wires not 18awg.


----------



## JoeDoe

The 12AX7 adapter is just great! Thanks to @gibosi for the solderless design. There's a noticeable improvement in weight and clarity over the 6AK5 family. Running a NOS GE 5751 triple mica that just sounds great. Got a Telefunken 12AX7 that's distorting a bit in the low end so it's benched for now.


----------



## mordy

Hi Joe Doe,
  
 Now when you are almost there having a Vector set up and a breadboard my humble suggestion is to buy an adapter  6SN7 to 12AX7. With this adapter octal tubes are simply plug and play. You will also need a voltage regulator and an external power supply.and you have to connect the two heater wires to the voltage regulator. It is well worth the the effort.
  
 http://www.ebay.com/itm/NEW-DC-DC-Step-Down-Power-Module-4V-38V-to-1-25V-36V-5A-Voltmeter-Adjustable-/251525539037?pt=LH_DefaultDomain_0&hash=item3a901724dd
  
 http://www.ebay.com/itm/1pc-6SN7-6SL7-TO-12AU7-12AX7-6-3v-filament-tube-adapter-/200952599533?pt=US_Home_Audio_Amplifiers_Preamps&hash=item2ec9b553ed
  
 An old laptop power supply or similar will work fine. With the voltage regulator you can adjust the voltage from 6.3V to around 18V if your PS puts out 20V. Then you can shop for oddball 8V or 12V tubes that may be cheaper than the 6.3V equivalents.


----------



## JoeDoe

mordy said:


> Hi Joe Doe,
> 
> Now when you are almost there having a Vector set up and a breadboard my humble suggestion is to buy an adapter  6SN7 to 12AX7. With this adapter octal tubes are simply plug and play. You will also need a voltage regulator and an external power supply.and you have to connect the two heater wires to the voltage regulator. It is well worth the the effort.
> 
> ...


 
 Thanks for the suggestion mordy. I will certainly look into this upgrade after I get some more time with my current set up. It's crazy how versatile this little amp can be for tube rollers!


----------



## gibosi

joedoe said:


> The 12AX7 adapter is just great! Thanks to @gibosi for the solderless design. There's a noticeable improvement in weight and clarity over the 6AK5 family. Running a NOS GE 5751 triple mica that just sounds great. Got a Telefunken 12AX7 that's distorting a bit in the low end so it's benched for now.


 
  
 Welcome to the LD Double Triode club! 
  
 I thought the 5751's were very good tubes, especially the GE and Sylvania. And there are many more very good double triodes you might want to try. But for now, enjoyl


----------



## hypnos1

mikelap said:


> Might need more than that!


 
  
 Hey mikelap.
  
 Looks like I must have sold my soul to the Devil...'cos not only do the 6as7s work in the IV SE, but even with just 1 in the right channel and the Psvane in the left the result is downright mind-boggling! The difference already sounds very similar to what you hinted at coming from your Woo...further info below...I still cannot believe that what I jokingly (with forlorn hope) tossed in the air re using them in our LDs has actually come into being - and beyond my wildest expectations. The Woo will have to wait a good while now lol!
  
  


trolldragon said:


> This is my MK IV board, the SE should be the same except for upgraded capacitors and jacks.
> 
> The two resistors circled in red are the 150Ω cathode resistors that Artsi spoke of, these resistors are 1 Watt. The two White Square resistors on the right edge of the board are 5 Watt sized just for reference.
> 
> ...




  
 I have to thank you once more TD for showing me the target resistors...despite a nasty crick in my neck after hours of peering inside the unit with temp probe in hand, fortunately it looks like once again the LD (MKIV SE at least) heaps surprise upon surprise. With the outside temp of said target being 56/57C after 1 hour and just 59C after 4 hours' continuous play, I think all should be OK, yes? - WELL below max operating temp, I believe...so hopefully no nasty surprises in store
	

	
	
		
		

		
		
	


	




 
  
 I can only hope other models are similarly forgiving...
  
  
 And so now, guys, an update on this most unexpected development :
  
 After a good many hours of my favourite test tracks, and much to my disbelief, my initial comments only just touched the surface.
 The dynamic sound and extra upper bass and lower mids did not come at the expense of anything else whatsoever...on the contrary, there's even _more_ detail across the entire spectrum. It would appear that no matter what part of the system is changed/upgraded, the C3gs maintain a perfect balance in all respects, and just keep on delivering more and more. Coupled with the 6AS7G (and still only in the right channel, with the Psvane in the left), at first it's almost as though there's _too_ much detail, but when you hear it with pinpoint precision and placement, the end result is truly mind-blowing. This gives _true_ holographic imaging and soundstage. Again, this doesn't come with a heavy price-tag...vocals (especially female) stay nicely, and intimately placed - not lost somewhere in the 3D stage!
 There is increased tonal range, both vocally and instrumentally, and a particular quality of reproduction that I have never properly noticed before, exemplified by, of all means, a tambourine in an old ELO track - ie you could hear the shake running around its rim like a musical ferris wheel (moving VERY fast, mind you!)...amazing...
 Bass had even more depth - not heavy-metal heavy - but with exquisite detail. And as for treble...sweet, delicate (especially with percussion), detailed and with delicious decay hardly does it justice.
  
 Anyway, that's just a taster of what the 6AS7G has delivered...had better get back to the "roller widow" before I'm in  the dog-house!.
  
 Will update again when I've finished the adapter for magical tube #2...
  
 Cheers for now.
  
 In case you missed the pic first time round :


----------



## mordy

Hi hypnos1,
  
 When trying the RCA 6AS7G as a driver, I found that the RCA/GE 6080 tubes were more to my liking. Perhaps you want to try a 6080 as well since they can be found very inexpensive.


----------



## mordy

Hi,
  
 Finally got the guts to cobble together an all sub miniature set up consisting of three Raytheon 1957 JAN-6832 tubes. No external PS is needed. I opted for a solderless solution for the power tubes and used two 9 pin socket extenders with small pieces of solid copper 18 gauge insulated wire to wedge the long leads into the pin sockets. It is a delicate job for fumbly fingers but doable.

 The little red dynamite charges are the eight little push pins made of the copper wire to keep the leads in place.

 Here is the experimental set up (euphemism for inability to make it look elegant) - notice the flying driver tube:
  
 Hey, it works, no hum unless I crank up the volume too high. The sound is good with the bass going very low. However, the slam and impact in the bass could be be better - hopefully it will improve with burn in. But it does not look pretty - let's try a night view:
  

 Looks better, but here is a real pretty picture from last week - spring is finally here!
  

  
 Happy tube rolling!


----------



## gibosi

mordy said:


> Finally got the guts to cobble together an all sub miniature set up consisting of three Raytheon 1957 JAN-6832 tubes. No external PS is needed. I opted for a solderless solution for the power tubes and used two 9 pin socket extenders with small pieces of solid copper 18 gauge insulated wire to wedge the long leads into the pin sockets. It is a delicate job for fumbly fingers but doable.
> 
> Hey, it works, no hum unless I crank up the volume too high. The sound is good with the bass going very low. However, the slam and impact in the bass could be be better - hopefully it will improve with burn in. But it does not look pretty - let's try a night view:


 
  
 As with the 6DJ8's, I just don't think these little sub-miniatures can move enough current to function as power tubes.... But as you haven't had time to burn them in yet, I just might be wrong...


----------



## hypnos1

mordy said:


> Hi hypnos1,
> 
> When trying the RCA 6AS7G as a driver, I found that the RCA/GE 6080 tubes were more to my liking. Perhaps you want to try a 6080 as well since they can be found very inexpensive.


 
  
 Hi mordy.
  
 Now that it looks like the 6AS7/6080 family are options for the powers, (yet) another quandary appears...having already spent a fortune on tubes, there's now _this_ family to explore - "she who must be obeyed" is not sounding too happy!! I must admit I _too_ am beginning to think enough is enough. This time, I really do think I have pushed the humble LD to its absolute limits. From stock to what I am hearing now is just way beyond belief, lol. I am of the firm belief that only the uber expensive "coke bottle" 5998 and equivalents would deliver more. And that is definitely NOT an option - for me, anyways. Plus, the law of diminishing returns would surely apply here, given my new level of sound!
  
 Re the 6080 that you prefer, you mentioned that it had more bass than the 6AS7, but with a shade less detail? As I am now getting all the depth of bass I would ever want, I much prefer to have the extra detail...especially as this is an area where the C3gS excels bar none. And from a good few researches, the nod seems generally to go to the 6AS7G. Thanks for your interest though, mordy.
 So it looks (once again!) as though I can now rest on my laurels and begin to hear anew all my favourite music as I have never heard it before, and at least without having spent _thousands_ of pounds/dollars 
	

	
	
		
		

		
		
	


	




.
  
 BFN and happy (continued!) rolling


----------



## sgbwill2

hypnos1 said:


>


 
 Is there a company that makes tube adapters such as you have made for your LD? as I am not the most skilful when it comes to DIY projects. I also wouldn't even know what components to buy if I were to undertake making the adapters myself. If there isnt a company that makes them a run through of how you made them would be much appreciated


----------



## hypnos1

sgbwill2 said:


> Is there a company that makes tube adapters such as you have made for your LD? as I am not the most skilful when it comes to DIY projects. I also wouldn't even know what components to buy if I were to undertake making the adapters myself. If there isnt a company that makes them a run through of how you made them would be much appreciated


 
  
 Hi sgbwill2.
  
 Good to see new blood interested in what we have been discovering over these past many months...hopefully you have the time - and patience! - to look back over all the guys' work...you should find it quite interesting and informative.
 As for my own set-up, if you're interested in the C3gs as drivers you are in luck..happydiy998 on ebay.com supplies C3g to 6AK5 adapters for $29.50 each...pricey, but I wouldn't recommend you even try going DIY if you don't have much experience in this area...too many possible pitfalls, believe you me!! The power tubes are 1 Psvane CV181 - TII, which is basically the same as a 6SN7 and 1 6AS7G. Again, you can get adapters for the 6SN7 - ebay.com, 6SN7 to 6CG7 for about $19.90 each. These and the drivers are then plug and play. With the MKIV SE it is simply a question of removing all the brass bits, then the adapters fit snugly into the LDs sockets. Other models that have rings atop the sockets need socket extenders also...if this applies to you, let us know and some of the other guys I am sure will chip in and advise you...
 As for the 6AS7G as power tube, I can only vouch for how it suits the MKIV SE, but again I'm sure others here with more knowledge than myself may have additional input. This tube family can again be used with the 6SN7 to 6CG7 adapter...*BUT THEY REQUIRE A SEPARATE POWER SUPPLY FOR THE HEATERS!* Pins 4 and 5 on the 6CG7 section MUST NOT enter the LD. If you are interested in going this route, there is plenty of info going back a good few pages that I suggest you read VERY carefully, and post any doubts you may have. There's a wonderful bunch of very helpful guys in this thread.
  
 Hopefully this has given you a bit more info to be getting on with...let us all know how you get on.
  
 Cheers for now...supper calls!


----------



## sgbwill2

Thanks for the reply. I think I will be getting myself some c3gs for my LD MKIII soon as they sound incredible from how you and some others have been describing them. The 6AS7G's also sound promising though the thought of having to solder on external heaters is putting me off  Have you tried them without the external heaters? I guess they would overheat quickly thats why you soldered them on in the first place but not having to solder them on would save me a lot of hassle.As for the 7 pin extenders hopefully I can remove the brass rings on my LD though I have yet to check if its possible. The psvane's might be the way I will have to go though they are very pricey so a standard 6SN7 might have to do.


----------



## gibosi

sgbwill2 said:


> ...............The 6AS7G's also sound promising though the thought of having to solder on external heaters is putting me off  Have you tried them without the external heaters? I guess they would overheat quickly thats why you soldered them on in the first place but not having to solder them on would save me a lot of hassle.As for the 7 pin extenders hopefully I can remove the brass rings on my LD though I have yet to check if its possible. The psvane's might be the way I will have to go though they are very pricey so a standard 6SN7 might have to do.


 
  
 Two 6AS7's draw 5 amps. The LD can provide, at most, 2.5 amps. If one was to try them without an external heater power supply, I can't see anything good happening. But I can easily imagine smoke and flames....
  
 While I have never heard a psvane, it is worth noting that some believe them to be very good while others believe that many old-stock 6SN7's are better. Given that old-stock 6SN7's can often be had for not much money, my advice is to start cheap, and then, if you are not satisfied, move up to more expensive tubes.
  
 I suggest that you check out the Reference 6SN7 thread to help you decide which ones you would like to try.
  
 http://www.head-fi.org/t/117677/the-reference-6sn7-thread


----------



## JoeDoe

I realize this may be the wrong thread for this, but I've decided to sell my 1+. If anyone is interested PM me referencing this post and I'll cut you a deal.


----------



## Rossliew

hypnos1 said:


> Hi sgbwill2.
> 
> Good to see new blood interested in what we have been discovering over these past many months...hopefully you have the time - and patience! - to look back over all the guys' work...you should find it quite interesting and informative.
> As for my own set-up, if you're interested in the C3gs as drivers you are in luck..happydiy998 on ebay.com supplies C3g to 6AK5 adapters for $29.50 each...pricey, but I wouldn't recommend you even try going DIY if you don't have much experience in this area...too many possible pitfalls, believe you me!! The power tubes are 1 Psvane CV181 - TII, which is basically the same as a 6SN7 and 1 6AS7G. Again, you can get adapters for the 6SN7 - ebay.com, 6SN7 to 6CG7 for about $19.90 each. These and the drivers are then plug and play. With the MKIV SE it is simply a question of removing all the brass bits, then the adapters fit snugly into the LDs sockets. Other models that have rings atop the sockets need socket extenders also...if this applies to you, let us know and some of the other guys I am sure will chip in and advise you...
> ...




Hi hypnos, I'm interested in your set up. Is it a simple plug and play with the adapters? Do I need a separate power supply as well? I'm no DIY person so bread boards and separate psu will be no no for me. Unless someone can build me one and I just plug and play from there


----------



## gibosi

joedoe said:


> I realize this may be the wrong thread for this, but I've decided to sell my 1+. If anyone is interested PM me referencing this post and I'll cut you a deal.


 
  
 Color me very surprised after your recent GE 5751 posting! What are you replacing your 1+ with?


----------



## JoeDoe

gibosi said:


> Color me very surprised after your recent GE 5751 posting! What are you replacing your 1+ with?


 
 I know I know! Still very impressed with this little guy. To me my new KICAS Caliente synergizes even better with the RS1s. Not to mention plenty of leftover power for my ZMFs.


----------



## Rossliew

Finally received a pair of generic 6SN7s which I've used with the adapters and a pair of Voshkod 6ZH1P-EV and the sound out of the HD800 is full with rumbling bass. In a a word, lovely! Sure, the treble and high end energy seems a tad held back but it sounds good with my metal tunes.


----------



## sgbwill2

gibosi said:


> Two 6AS7's draw 5 amps. The LD can provide, at most, 2.5 amps. If one was to try them without an external heater power supply, I can't see anything good happening. But I can easily imagine smoke and flames....
> 
> While I have never heard a psvane, it is worth noting that some believe them to be very good while others believe that many old-stock 6SN7's are better. Given that old-stock 6SN7's can often be had for not much money, my advice is to start cheap, and then, if you are not satisfied, move up to more expensive tubes.
> 
> ...


 
 Thanks for explaining that. I have just ordered 2 sets of p2n7's. a set of 1578 replicas and a pair of GE 6"N7GTB's. Just need to buy the adapters now. I dont think I am able to remove the brass rings so was wondering do you know of anyone who sells 7 pin extenders? As for c3g adapters I saw the ones you recommended but was wondering if these also work as they are slighltly cheaper and dont seem so rough around the edges:
 http://www.ebay.co.uk/itm/321135529598?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649


----------



## gibosi

sgbwill2 said:


> Thanks for explaining that. I have just ordered 2 sets of p2n7's. a set of 1578 replicas and a pair of GE 6"N7GTB's. Just need to buy the adapters now. I dont think I am able to remove the brass rings so was wondering do you know of anyone who sells 7 pin extenders? As for c3g adapters I saw the ones you recommended but was wondering if these also work as they are slighltly cheaper and dont seem so rough around the edges:
> http://www.ebay.co.uk/itm/321135529598?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649


 
  
 To use the 6SN7's as power tubes, you will need to use a 9-pin "extender", or socket saver, to allow for the brass rings. This plugs into your power tube sockets and then you plug your 6NS7 to 9-pin adapter into the extender.
  
 http://www.ebay.com/itm/10-BAKELITE-9pin-tube-socket-testing-saver-for-12AX7-12AT7-12AU7-6DJ8-ECC82-6922-/221434781772?pt=Vintage_Electronics_R2&hash=item338e8aa04c
  
 To use the C3g's as drivers, you will need a 7-pin extender, or socket saver, to allow for the brass rings:
  
 http://leedsradio.com/parts-sockets.html#savers
  
 Test socket 7 pin miniature                           $8.00
  
 And the 8-pin to 7-pin adapter you found is specifically to adapt a 6X5 tube to a 6X4 socket. It will not work to adapt a C3g to a 6AK5 socket.


----------



## sgbwill2

Just ordered some 9 pin extenders and 9 to 8 pin adapters as well as 2 7 pin extenders. Still have to get the c3g's though and their adapters. Unfortunately because leesradio is based in the US postage for the 2 7 pin extenders was $16  thanks for your advice though and I hope these tubes are worth the extra money buying the extenders and adapters.


----------



## hypnos1

artsi said:


> Now this is starting to look like a Tube Amplifier to me. Excellent!
> 
> But there is still some way to go.
> 
> ~15kg


 
  
 Hi artsi - if you're still about!
  
 Although nowhere near the 15kg, is this LD now looking even more the business?...:
  

  
 And as for sound...well, now with the 6AS7Gs in both channels all I can say is...I'm lost for words! (which is unusual for me lol!).
  
 Suffice to say there is even more of everything I have stated previously with just 1 in the hot seat - fortunately not _too_ hot! Your earlier concerns, I am glad to say, seem to be handled amazingly well (by my MKIV SE at least), viz resistor temp maxing at 59C after 4 hours' continuous play. So hopefully everything should be OK?
  
 ps. An addition to end results...there appear to be more 'layers' of sound - again something I haven't really appreciated/noticed in my rig to the same level at all before.
  
 Also, and much to my surprise, I'm not having to crank up the volume much at all compared to before ...what can this humble marvel NOT cope with, I ask?!
  


gibosi said:


> Two 6AS7's draw 5 amps. The LD can provide, at most, 2.5 amps. If one was to try them without an external heater power supply, I can't see anything good happening. But I can easily imagine smoke and flames....
> 
> While I have never heard a psvane, it is worth noting that some believe them to be very good while others believe that many old-stock 6SN7's are better. Given that old-stock 6SN7's can often be had for not much money, my advice is to start cheap, and then, if you are not satisfied, move up to more expensive tubes.
> 
> ...


 
  
 Wise words as usual gibosi...given the price difference, some nice used (and already burnt-in!) 6SN7s would be a MUCH better buy.
  
  
  


rossliew said:


> Finally received a pair of generic 6SN7s which I've used with the adapters and a pair of Voshkod 6ZH1P-EV and the sound out of the HD800 is full with rumbling bass. In a a word, lovely! Sure, the treble and high end energy seems a tad held back but it sounds good with my metal tunes.


 
  
 Hi R.
  
 Glad you're happy with the 6SN7s as power tubes...now if you could get someone to adapt the adapters to take an external heater supply, and splash out on the C3gs (preferably the 'S' version if possible, and not too much more $) I can't even begin to imagine what your 800s would sound like, if my 650s are anything to go by!
  
  


sgbwill2 said:


> Thanks for explaining that. I have just ordered 2 sets of p2n7's. a set of 1578 replicas and a pair of GE 6"N7GTB's. Just need to buy the adapters now. I dont think I am able to remove the brass rings so was wondering do you know of anyone who sells 7 pin extenders? As for c3g adapters I saw the ones you recommended but was wondering if these also work as they are slighltly cheaper and dont seem so rough around the edges:
> http://www.ebay.co.uk/itm/321135529598?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649


 
  
 Am glad gibosi is putting you on the right track...what a guy! I agree about the appearance of those C3g adapters, but it seems they work OK. Good luck with your efforts (and expense!) - I'm sure you won't regret it one bit 
	

	
	
		
		

		
			





.
  
 Speaking of adapters, just thought I'd post a pic of my latest one - for the 6AS7G. I think I'm finally getting the hang of making these things, but what a work-up...not to mention turning me into a nervous wreck!! Ah well, all because the guy loves _silver_...
  

  
 The added bonus is that I can route the heater wires out the back of it...I really love _neatness, _where at all possible, lol.
  
 ps. Dummy pin 9 to aid positioning - not wasting silver there!


----------



## mordy

Hi hypnos1,
  
 Congrats to your super modded amp! Wish I could make these mods, but unless the adapters were available commercially I doubt that I'll get there since I don't think I could make them myself. Hopefully one of the Chinese adapter makers will pick up on your neat idea of having the heater wires coming out of the adapter socket!
  
 Meanwhile I have gone the other direction re the size of the tubes and now I am using three sub miniature tubes; two as power tubes and one as driver. Surprisingly, this combination works well with a balanced and lively presentation. The treble is excellent and the bass is quite strong and I don't have the feeling that it is running out of steam. These tubes do not have the ultimate grip on the lowest frequencies of a bass drum with the bass control turned up fully,  but overall very pleasant and engaging to listen to. Look, for $7 worth of tubes this is a true bargain!
  
Raytheon Jan 6832 Submini dual Triode


----------



## Rossliew

gibosi said:


> To use the 6SN7's as power tubes, you will need to use a 9-pin "extender", or socket saver, to allow for the brass rings. This plugs into your power tube sockets and then you plug your 6NS7 to 9-pin adapter into the extender.
> 
> http://www.ebay.com/itm/10-BAKELITE-9pin-tube-socket-testing-saver-for-12AX7-12AT7-12AU7-6DJ8-ECC82-6922-/221434781772?pt=Vintage_Electronics_R2&hash=item338e8aa04c
> 
> ...


 
  
 Hi G,
  
 With the C3G to 6AK5 adapter plus the 7 pin miniature socket saver, will the C3g tubes be plug and play without the need for an external power supply? If it is so, I will order some pronto!


----------



## sgbwill2

The 2 6AS7Gs look great hypno. Rossliew according to previous posts the c3g's are plug and play with the adapter. Hypno or gibosi I was wondering what are the differences between the c3g and c3m tubes? I see the c3g's have gold pins but thats the only difference I have noticed. Have either of you had experience with the c3m's?


----------



## Rossliew

sgbwill2 said:


> Rossliew according to previous posts the c3g's are plug and play with the adapter.


 
 Great ! Looks like another round of fun hunting for tubes


----------



## sgbwill2

Haha I know your troubles; im currently waiting for 6sn7 tubes and adapters and i am also in the process of getting some c3g tubes and adapters as well. its turning out to be quite an expensive process. my poor wallet


----------



## Rossliew

sgbwill2 said:


> Haha I know your troubles; im currently waiting for 6sn7 tubes and adapters and i am also in the process of getting some c3g tubes and adapters as well. its turning out to be quite an expensive process. my poor wallet


 
 I bet it's all well worth it : )
  
 Need to continue the hunt for affordably priced 6sn7s too. Anyone with spares willing to sell them off, kindly pm me!


----------



## Rossliew

gibosi said:


> To use the C3g's as drivers, you will need a 7-pin extender, or socket saver, to allow for the brass rings:
> 
> http://leedsradio.com/parts-sockets.html#savers
> 
> Test socket 7 pin miniature                           $8.00


 
 I contacted Leeds Radio and they tell me that is a test socket and not a socket saver. Can I still order it and use it as a socket saver with the c3g to 6ak5 adapter ? I tried searching Ebay for a 7 pin socket saver but nothing came up...


----------



## gibosi

rossliew said:


> With the C3G to 6AK5 adapter plus the 7 pin miniature socket saver, will the C3g tubes be plug and play without the need for an external power supply? If it is so, I will order some pronto!


 
  
 No external power supply is needed. The C3g's draw .37 amps each, for a total of .74 amps, which is well within the LD's internal 1 amp heater supply. Two C3g's, two adapters and  two extenders, and you are good to go.
  


rossliew said:


> I contacted Leeds Radio and they tell me that is a test socket and not a socket saver. Can I still order it and use it as a socket saver with the c3g to 6ak5 adapter ? I tried searching Ebay for a 7 pin socket saver but nothing came up...


 
  
 Technically, it is a test socket, but it can be used as a socket saver. The only difference is the exposed metal rods on top which would allow one to use a multimeter to check such things as plate voltage, grid voltage and so forth.


----------



## gibosi

sgbwill2 said:


> The 2 6AS7Gs look great hypno. Rossliew according to previous posts the c3g's are plug and play with the adapter. Hypno or gibosi I was wondering what are the differences between the c3g and c3m tubes? I see the c3g's have gold pins but thats the only difference I have noticed. Have either of you had experience with the c3m's?


 
  
 The C3g has 6.3 volt heaters, whereas, the C3m has 20 volt heaters. You would need an adjustable external power supply to use these. There are also some other construction differences, but I have no idea how different they sound. There is also a C3o, which is a 6.3 volt version of the C3m, but these don't show up on eBay all that often.
  
 Edit: Also, the socket would have to be reconfigured for C3m/C3o tubes, which means the C3g-to-6AK5 adapter would not work....


----------



## sgbwill2

gibosi said:


> The C3g has 6.3 volt heaters, whereas, the C3m has 20 volt heaters. You would need an adjustable external power supply to use these. There are also some other construction differences, but I have no idea how different they sound. Also, there is also a C3o, which is a 6.3 volt version of the C3m, but these don't show up on eBay all that often.


 
 Thanks for clearing that up. Do you think the c3o is sonically identical to the c3g?


----------



## Rossliew

Thanks @Gibosi. Proceeding with my orders!
  
 Them 6SN7s have so many variations, i'm going dizzy...


----------



## gibosi

joedoe said:


> I know I know! Still very impressed with this little guy. To me my new KICAS Caliente synergizes even better with the RS1s. Not to mention plenty of leftover power for my ZMFs.


 
  
 The reviews certainly suggest that the KICAS Caliente is a very good little amp, so I am not surprised you are liking it. However, I think you should keep the LD 1+, and for the purpose of furthering our "LD Research Program", put a MUSES 02 op amp in it and a pair of C3g's and tell us how it compares to your KICAS.


----------



## gibosi

sgbwill2 said:


> Thanks for clearing that up. Do you think the c3o is sonically identical to the c3g?


 
  
 As the C3o is identical to the C3m, except for the heaters, these two tubes should sound the same. However, I haven't found reviews comparing them to the Cg3. And besides, the C3o requires a different adapter. The C3g adapter will not work. One more obstacle that would have to be overcome.....


----------



## sgbwill2

Thanks I think i will play it safe then and get the c3g's


----------



## hypnos1

mordy said:


> Hi hypnos1,
> 
> Congrats to your super modded amp! Wish I could make these mods, but unless the adapters were available commercially I doubt that I'll get there since I don't think I could make them myself. Hopefully one of the Chinese adapter makers will pick up on your neat idea of having the heater wires coming out of the adapter socket!
> 
> ...


 
  
 Hi mordy. Thanks. But hey, it's not _too_ difficult to alter the 6Cg7 adapter to take the 6AS7/6080 as power tube. With the MKIV, and no extender necessary once all the brass bits are removed, it just needs pins 4 and 5 cut with enough left to solder the new power supply wires, then covered with tape. I found that worked perfectly (obviously they mustn't project _too_ far out!). If socket extenders are needed (I'm assuming they are available for 8-pin to LD's 9-pin?), the wires could be wedged in atop the extender and its pins 4 and 5 at the LD cut off completely.
 Well, so I _think_ anyway, mordy...
  


rossliew said:


> Great ! Looks like another round of fun hunting for tubes


 
  
  
 Yo R. That's all part of a tube roller's lot, y'know! And I have to admit I _have_ spent far more than I ever anticipated. But still cheaper than out playing golf (if not so healthy lol!).
  


sgbwill2 said:


> Thanks I think i will play it safe then and get the c3g's


 
  
 You will not be disappointed, mon ami. And with the Siemens NOS 'S' versions going for about $70 on ebay, I don't think you will find a better deal...the (20V) C3m seems to have now jumped up in price and certainly is not worth bothering with at current prices.
  
 Happy hunting and rolling...
  
  
  
 And finally I know you must all be getting fed up with my ravings, but after a few hours' burn-in of my new adapter, the two 6AS7Gs are forcing me to write that I cannot OVERstate the difference they are making. The shift to another level is at least equal to the C3gS phenomenon... Do I now have a MK9? Hey, even _that_ doesn't have the C3g!  This MKIV SE is now a TOTALLY different animal to even a few months ago, when we were a good way on from original stock. All the trials - not to mention tribulations (and expense!) - have been worth the journey. Not to mention the wonderful camaraderie along the way, with some great guys.
 So whichever direction you take, mes amis, I can only hope you experience the sense of wonderment and sheer joy I am currently enjoying...way beyond my expectations.
  
 HAPPY ROLLING EVERYONE


----------



## philiptw

Hey guys, I have just started my tube rolling journey with the LD mk3 and I am a bit confused to whether these are genuine or not? Also, the seller is stating quite a few figures that I dont understand...
 So.. was wondering if I could find some help from you experts 
  
  
 It is the Voskhod 6ZH1P-EV EF95 I am after..
  
 http://www.ebay.co.uk/itm/2-matched-6J1P-EV-EF95-6AK7-Gold-Platinum-grid-NIB-/130950289707?pt=Vintage_Electronics_R2&hash=item1e7d3ed92b
  
 http://www.ebay.co.uk/itm/2-matched-Gold-pins-Gold-Platinum-grid-6J1P-EV-EF95-6AK5-6AK7-NEW-NOS-NIB-/131032948276?pt=Vintage_Electronics_R2&hash=item1e822c1e34
  
  
 thank you guys!


----------



## TrollDragon

philiptw said:


> It is the Voskhod 6ZH1P-EV EF95 I am after..


 
  
 These ones here are genuine, I dont think there are any 6Ж1П-ЕВ fakes as they would not be worth replicating...
http://www.ebay.com/itm/2x-MATCHED-6J1P-EV-VOSKHOD-70s-TUBES-GOLD-GRID-6J1P-EF95-6F32-6AK5-PAIR/310952351749
  
 And a pair of these to go with...
http://www.ebay.com/itm/6HM5-6HA5-EC900-export-quality-audio-triode-tube-NOS-FREE-SHIPPING-/300879467071


----------



## philiptw

trolldragon said:


> These ones here are genuine, I dont think there are any 6Ж1П-ЕВ fakes as they would not be worth replicating...
> http://www.ebay.com/itm/2x-MATCHED-6J1P-EV-VOSKHOD-70s-TUBES-GOLD-GRID-6J1P-EF95-6F32-6AK5-PAIR/310952351749
> 
> And a pair of these to go with...
> http://www.ebay.com/itm/6HM5-6HA5-EC900-export-quality-audio-triode-tube-NOS-FREE-SHIPPING-/300879467071


 
  
 Thank you! ^_^ 
  
 I intend to keep the RTC 5654 as backup tubes~
 Already looking forward to that Voskhod!


----------



## gibosi

hypnos1 said:


> Hi mordy. Thanks. But hey, it's not _too_ difficult to alter the 6Cg7 adapter to take the 6AS7/6080 as power tube. With the MKIV, and no extender necessary once all the brass bits are removed, it just needs pins 4 and 5 cut with enough left to solder the new power supply wires, then covered with tape. I found that worked perfectly (obviously they mustn't project _too_ far out!). If socket extenders are needed (I'm assuming they are available for 8-pin to LD's 9-pin?), the wires could be wedged in atop the extender and its pins 4 and 5 at the LD cut off completely.
> Well, so I _think_ anyway, mordy...


 
  
 Thinking about this a bit....
  
 Some of us might remember disassembling 7-pin socket-savers and using solder and wire to connect various pins together to allow us to strap 6AU7's and heptodes for use in our LDs. Looking at Hypnos1's custom-made 6AS7 adapter suggests to me that something similar could be done to allow the use of 6AS7's.  First, disassemble a 9-pin socket-saver and drill a hole in the housing to allow two heater wires to pass through. After that, solder wires to pins 4 and 5, which will later be connected to an external PS. Once done, reassemble the saver, routing the wires out through the drilled hole. Once assembled, cut off pins 4 and 5 at the bottom of the saver. Plug the socket savers into the LD and connect the wires to the external heater PS.  This _should_ work!


----------



## Rossliew

philiptw said:


> Thank you! ^_^
> 
> I intend to keep the RTC 5654 as backup tubes~
> Already looking forward to that Voskhod!


 
 The RTC's have got good treble extension (at least with my LD 3 and to my ears) and Voshkods are truly bass monsters!


----------



## gibosi

Received this little treasure the other day: An E80CC manufactured in Hamburg, Germany, October, 1956 (WK2 D6J). It has a horseshoe getter and pinched waist. However, the pinching is not as deep and well-defined as it is on my 1955 Eindhoven tube. I got it for $45, shipped from Germany, which isn't too bad when you consider a pair of C3g's go for around $75. Like the C3g, the E80CC is an ultra-linear, frame-grid tube. And in fact, it has a signicantly lower distortion figure than the C3g. (That is, when we strap the C3g, to convert it from a pentode to a triode, the distortion increases to a level approaching that of a 6SN7, still quite low, but not as low as the E80CC.)
  
 Have spent a few hours with this tube, and in my opinion, this is right up there with the C3g, top-tier.


----------



## hypnos1

Hey guys...a word of WARNING, if anyone is thinking of buying the 8A voltage regulator/converter I posted a while ago.
  
 After a near heart attack when the gorgeous glow from my 6AS7Gs disappeared - I always assume the worst! - it turned out to be said cheapo chinese converter. At £4.99, incl shipping, I should have known better. Mind you, with the possible high initial surges from the 6AS7Gs I suppose it isn't really fair on the poor thing! Probably, all would be well using 2 of same 
	

	
	
		
		

		
		
	


	




...
  
 Might just bite the  bullet and get a _proper_ unit, now I know it would be well worth the investment, lol.
  
 Cheers


----------



## Androb

I just received some new tubes for my mkvi+ 
  

  
 The left grey one is the original tube, right is Ken rad VT-231! 
  

  

  

 This is the RCA 6SL7GT grey glass version!


----------



## TrollDragon

hypnos1 said:


> Hey guys...a word of WARNING, if anyone is thinking of buying the 8A voltage regulator/converter I posted a while ago.
> 
> After a near heart attack when the gorgeous glow from my 6AS7Gs disappeared - I always assume the worst! - it turned out to be said cheapo chinese converter. At £4.99, incl shipping, I should have known better. Mind you, with the possible high initial surges from the 6AS7Gs I suppose it isn't really fair on the poor thing! Probably, all would be well using 2 of same
> 
> ...


 
  
 Cheap Chi-Nee schiit will bite you on the ass every time.
 Your just lucky it only burned out and didn't go the other way dumping the source voltage into the filaments...
  
 Get one of these and never worry again.
http://www.ebay.com/itm/0-20VDC-Adjustable-10A-Power-Supply-PS10AD-/180632120608


----------



## hypnos1

gibosi said:


> Received this little treasure the other day: An E80CC manufactured in Hamburg, Germany, October, 1956 (WK2 D6J). It has a horseshoe getter and pinched waist. However, the pinching is not as deep and well-defined as it is on my 1955 Eindhoven tube. I got it for $45, shipped from Germany, which isn't too bad when you consider a pair of C3g's go for around $75. Like the C3g, the E80CC is an ultra-linear, frame-grid tube. And in fact, it has a signicantly lower distortion figure than the C3g. (That is, when we strap the C3g, to convert it from a pentode to a triode, the distortion increases to a level approaching that of a 6SN7, still quite low, but not as low as the E80CC.)
> 
> Have spent a few hours with this tube, and in my opinion, this is right up there with the C3g, top-tier.


 
  
 Looks like you've found another really nice tube,g - too late for me, anyway! Keep up the good work (is there no bottom to your wallet lol?!).
  
  


trolldragon said:


> Cheap Chi-Nee schiit will bite you on the ass every time.
> Your just lucky it only burned out and didn't go the other way dumping the source voltage into the filaments...
> 
> Get one of these and never worry again.
> http://www.ebay.com/itm/0-20VDC-Adjustable-10A-Power-Supply-PS10AD-/180632120608


 
  
 Yes TD, it does NOT pay to go too cheap - with _anything_! So I'll be investing in a bench DC power supply - but one not _quite_ so expensive, methinks!
 But looking on the bright side, at least it provided the necessary - and very cheaply - for me to check those resistor temperatures...so all was not wasted, really 
	

	
	
		
		

		
		
	


	




.


----------



## TrollDragon

Really what you need instead of a power supply is a DarkVoice / LaFigaro 339, it will take 6AS7's or 6080's by default as power tubes with pentodes as drivers. The build quality on this amp is incredible so it would be very easy to conver the driver sockets to C3g/s pentode sockets.
  
 Reposted from the DarkVoice 339 thread.
  

  
 Now for the best part...

  
 Cathode Resistors...


----------



## kvtaco17

Or get a Glenn OTL.
  

  
 uses 6AS7's, 6SN7's as power/driver and 3DG4/5U4 rectifiers and sounds glorious!


----------



## sgbwill2

kvtaco17 said:


> Or get a Glenn OTL.
> 
> 
> 
> uses 6AS7's, 6SN7's as power/driver and 3DG4/5U4 rectifiers and sounds glorious!


 
 I was wondering how much does Glenn roughly charge for the amps he produces? such as the one pictured


----------



## kvtaco17

sgbwill2 said:


> I was wondering how much does Glenn roughly charge for the amps he produces? such as the one pictured


 
 I will PM u


----------



## gibosi

hypnos1 said:


> Looks like you've found another really nice tube,g - too late for me, anyway! Keep up the good work (is there no bottom to your wallet lol?!).


 
  


trolldragon said:


> Really what you need instead of a power supply is a DarkVoice / LaFigaro 339, it will take 6AS7's or 6080's by default as power tubes with pentodes as drivers. The build quality on this amp is incredible so it would be very easy to conver the driver sockets to C3g/s pentode sockets.


 
  
 There is no denying that I buy a lot of tubes.... But I do so with the long view in mind. I consider most of the tubes I purchase to be investments for the future. The E80CC I just purchased for $45 often goes for around $100 and more. I never pay top dollar. And therefore, worst case, if I decide to sell this tube, I can always get back at least what I paid, and very probably more.
  
 However, it is not really my intention to sell these tubes. This is only a fallback plan, Plan B. Plan A is to use them in any future amp I buy. And so, as much as it appears that the DarkVoice / LaFigaro 339 is a great amp, it is incompatible with all my current tubes, and I won't even consider it. My current tubes must work in my next amp in order for my current investment to pay off. And fortunately, this restriction is very easy to live with, as there are plenty of wonderful amps that use these tubes. The hardest part is deciding which amp to get.


----------



## i luvmusic 2

Thinking ahead is always a good idea
	

	
	
		
		

		
		
	


	



 For example i have 12A.. 6SN7 6SL7 12SN7 and 6AS7 tubes all will work with my future CRACK.


----------



## Rossliew

Just received my Ken-Rad VT231 tubes and playing them now with some BTB EF95 blue tubes...sounding solid, full bodied and noticeably more harder hitting bass thumps. I'm liking it over my generic 6SN7s.


----------



## gibosi

rossliew said:


> Just received my Ken-Rad VT231 tubes and playing them now with some BTB EF95 blue tubes...sounding solid, full bodied and noticeably more harder hitting bass thumps. I'm liking it over my generic 6SN7s.


 
  
 The Ken-Rad's are one of the very best 6SN7's for bass, no doubt about it. But how are you liking the mids and the highs?


----------



## hypnos1

trolldragon said:


> Really what you need instead of a power supply is a DarkVoice / LaFigaro 339, it will take 6AS7's or 6080's by default as power tubes with pentodes as drivers. The build quality on this amp is incredible so it would be very easy to conver the driver sockets to C3g/s pentode sockets.
> 
> Reposted from the DarkVoice 339 thread.
> 
> ...


 
  
 WOW!...Just _love_ those resistors...(what on earth is happening to me? 
	

	
	
		
		

		
		
	


	




).
  
 Sure is one beautifully-built piece of kit - are you intent upon _bankrupting _me or what?! *IF* my beloved MKIV SE should die on me one day, I could be sorely tempted by this beauty...especially as I could use my C3GSs. Better get saving, eh? - if only to pay for the accursed customs charges!!
  
  
  


kvtaco17 said:


> Or get a Glenn OTL.
> 
> 
> 
> uses 6AS7's, 6SN7's as power/driver and 3DG4/5U4 rectifiers and sounds glorious!


 
  
 So you want to see me broke as well, mon ami? What chance do I stand? - another lovely-looking machine 
	

	
	
		
		

		
		
	


	




. Perhaps I should try the lottery after all!...
  
  


gibosi said:


> There is no denying that I buy a lot of tubes.... But I do so with the long view in mind. I consider most of the tubes I purchase to be investments for the future. The E80CC I just purchased for $45 often goes for around $100 and more. I never pay top dollar. And therefore, worst case, if I decide to sell this tube, I can always get back at least what I paid, and very probably more.
> 
> However, it is not really my intention to sell these tubes. This is only a fallback plan, Plan B. Plan A is to use them in any future amp I buy. And so, as much as it appears that the DarkVoice / LaFigaro 339 is a great amp, it is incompatible with all my current tubes, and I won't even consider it. My current tubes must work in my next amp in order for my current investment to pay off. And fortunately, this restriction is very easy to live with, as there are plenty of wonderful amps that use these tubes. The hardest part is deciding which amp to get.


 
  
 Looks like I will have to call you 'wile-e-coyote' from now on, gibosi...certainly method in the madness, lol!
  
 But yet another deserter from the camp in the offing? What shall we do if you disappear from our midst?...All head for the Figaro or Glenn perhaps?! - is there a VERY generous, well-wishing philanthropist out there taking pity on us poor tube-rollers? Methinks not, alas 
	

	
	
		
		

		
		
	


	




.
 Ah well, must get back to my (pining) more humble offering...I think I've upset her somewhat! But I shall reassure her...once my 'proper' power supply arrives, that is!!


----------



## kvtaco17

hypnos1 said:


> WOW!...Just _love_ those resistors...(what on earth is happening to me?
> 
> 
> 
> ...


 
  
 I shall tempt you no more...
  

  
  
  

  

  

  
 ...unless shots of tubes in the dark are tempting...


----------



## superdux

I have the 12AX7 adaptor from MIKELAP running before my C3G's are tested. On top of the Adapter is a 12AX7 to 6SL7 adapter and i plugged in a reissue tube Tung Sol 6SL7GT with brown base. At first it was a bit bass shy and its still burning in and now the bass has gotten better.
 UPDATE:after about 5-10 albums the tube has become very resolving with more detail than my vohskods.I did hear some bass bleed into the mids but i expect that to be a burn-in issue. Bass is good now too. Highs are very present but not sharp on my HD650. Album i listened to was "Brighten the Corners" from Pavement.This album is very good for testing distortion of the drivers as in the song "Stereo". Until now i think only my T50RPs haven´t clipped but i can test so if someones wishes me to.


----------



## gibosi

hypnos1 said:


> Sure is one beautifully-built piece of kit - are you intent upon _bankrupting _me or what?! *IF* my beloved MKIV SE should die on me one day, I could be sorely tempted by this beauty...especially as I could use my C3GSs. Better get saving, eh? - if only to pay for the accursed customs charges!!
> 
> But yet another deserter from the camp in the offing? What shall we do if you disappear from our midst?...All head for the Figaro or Glenn perhaps?! - is there a VERY generous, well-wishing philanthropist out there taking pity on us poor tube-rollers? Methinks not, alas
> 
> ...


 
  
 Without knowing how pentodes are configured in the Darkvoice 339, it may or may not be a simple matter to use the C3g. The Cg3 has more gain than most pentodes. In fact, even strapped as a triode, it has more gain than many unstrapped pentodes....
  
 If and when I do get another amp, I will certainly keep using my LD. One of the real advantages of a hybrid is being able to compare drivers. For example, I have a bunch of ECC40's from as many as 8 different assembly lines that I want to compare. The LD 1+ is superb for this. More lowly, but very important, is burning in new tubes. With a solid-state output I would not be putting needless hours on power tubes. And getting another amp will free the LD up to try more strange tubes. For example, if my LD is out of commission for a week as I configure and rewire my external socket, I can listen to my new amp. I want to give the E182CC a try. And even more strange, I want to try to roll a pair of common-cathode E90CC's by converting these double triodes into single triodes. I will need two 7-pin external sockets for this. So I anticipate that I will continue to be a presence here, and I expect that I will continue to push the envelope


----------



## Rossliew

gibosi said:


> The Ken-Rad's are one of the very best 6SN7's for bass, no doubt about it. But how are you liking the mids and the highs?


 
 Hmm...I didn't pay too much attention to the mids and highs but unless it is very noticeable, i don't recall hearing any roll offs in the highs nor smearing/recessed mids. With the HD800 in tow, it sounded like how the recording was supposed to sound, just with thumpier bass : ) So far, am liking what I hear.


----------



## Nic Rhodes

The E182CC  (and 5687) are excellent driver tubes. They can even drive 300Bs well, something the 6SN7GT can't do well. Great to see the use of C3gs and ECC40s also, FINE TUBES. Has anyone tried to use a WE 437A / STC 3A/167M yet?


----------



## TrollDragon

This pair of WE437A's would be fine!

http://www.ebay.com/itm/Western-Electric-WE437A-Tubes-Matched-Pair-437A-437-Gold-standard-with-Curves-/181391104557

Then all you would need is a pair of WE421A's as power tubes.


----------



## gibosi

nic rhodes said:


> The E182CC  (and 5687) are excellent driver tubes. They can even drive 300Bs well, something the 6SN7GT can't do well. Great to see the use of C3gs and ECC40s also, FINE TUBES. Has anyone tried to use a WE 437A / STC 3A/167M yet?


 
  
 Well no, I haven't tried these tubes. And given the prices I am seeing on eBay, I don't expect to be trying them anytime soon, especially since we need two of them! lol
  
 But sure, if I could get a pair for less than $100, I would be happy to give them a try.


----------



## gibosi

rossliew said:


> Hmm...I didn't pay too much attention to the mids and highs but unless it is very noticeable, i don't recall hearing any roll offs in the highs nor smearing/recessed mids. With the HD800 in tow, it sounded like how the recording was supposed to sound, just with thumpier bass : ) So far, am liking what I hear.


 
  
 I can easily believe that the Ken-Rad, with it's huge bass and slightly dark sound signature, is a great match with the HD800. Others with the HD800 should try one.


----------



## Nic Rhodes

gibosi said:


> Well no, I haven't tried these tubes. And given the prices I am seeing on eBay, I don't expect to be trying them anytime soon, especially since we need two of them! lol
> 
> But sure, if I could get a pair for less than $100, I would be happy to give them a try.


 
  
 very possible with the STCs, certainly the right ball park but not everyone need to go out to buy new tubes in to try these  If people are happy changing bases, adding power supplies etc then these are the natural extension in triodes. The thread has moved a long way from the $5 strapped pentode with some expensive 'ECC88 family'  and unusual based now being tried.


----------



## Rossliew

gibosi said:


> I can easily believe that the Ken-Rad, with it's huge bass and slightly dark sound signature, is a great match with the HD800. Others with the HD800 should try one.


 
 Yes, they do! But i have to also add, the extra bass does not sacrifice the inherent sound sig of the HD800 i.e. its high frequency goodness! I admit the HD800 got me into treble when I was quite a bass head back in the day with no care in the world for mids or highs..


----------



## hypnos1

hypnos1 said:


> Hey guys...a word of WARNING, if anyone is thinking of buying the 8A voltage regulator/converter I posted a while ago.
> 
> After a near heart attack when the gorgeous glow from my 6AS7Gs disappeared - I always assume the worst! - it turned out to be said cheapo chinese converter. At £4.99, incl shipping, I should have known better. Mind you, with the possible high initial surges from the 6AS7Gs I suppose it isn't really fair on the poor thing! Probably, all would be well using 2 of same
> 
> ...


 
  
 Update on above warning...
  
 Turns out it wasn't anything really nasty - the output connector block came loose from it's solder points, caused by my overenthusiasm in tightening the screws (mind you, I wasn't _that_ brutal!). A quick re-solder and all is well. So now I can get back to my Ferraried LD - oh joy!!


----------



## mordy

Hi,
  
 After having listened extensively to the dual triode Raytheon 6832 sub miniature tubes in combination as both power and driver tubes I have come to the conclusion that they they sound very good. The presentation is lively, quick and balanced with a wide sound stage. The only drawback is a lack of real heft and slam in the bass, although it goes quite low and the midbass is very good. The bass does not break up, but doesn't have the full impact on bass heavy recordings.
  
 This tube is very neutral and because of this it perhaps lacks in charisma but nevertheless it is very pleasant to listen to. These tubes deliver a bigger bang for the buck than most. They are still available on Ebay for $6.95/pair incl shipping (although I received three tubes for this price). Search Ebay for this:
  
 Raytheon Jan 6832 Submini dual Triode. Matched Pair, Excellent NOS tubes!
  
 I am afraid to ask TD if a voltage regulator rated max 3A will work for a 6080 tube that draws 2.5A. Make that a Chinese voltage regulator. What do you think?


----------



## TrollDragon

Hey mordy

Feel free to ask anything, anytime... I'll do my best to give you an answer that falls on the side of caution all the time. 

Your Chi-nee 3A'er will most likely power the 2.5 perfectly fine, just remember that tubes can possibly draw up to 3x the rated current at startup. I believe those regulators have an over current protection built in so at the worst, it would just shut down.

I always find that running things close to maximum is never any good, heat is the major killer of electronics, so you might have to put a heatsink on the regulator if it gets too hot.

Just like the a 4 cylinder engine, it will last a lot longer running it at 3000 RPM than at 6500...

I would order an 8A or higher off of eBay and never worry about the current draw.

Unless you break the solder on the terminals with over enthusiasm. 

Try the 3A first and see how it fares.


----------



## i luvmusic 2

Hi TD,
  Since we are on a regulator topic i replaced the trim pot(10K) on one of my regulator with a 10K pot so i can install a knob on it the problem i have is when i turn the POT i can only turn(7 to 9 o'clok) a little and the voltage reading on the regulator is already max out.What could be the problem?Thanks!


----------



## i luvmusic 2

Here is the picture of the regulator.


----------



## TrollDragon

Hey ILM2,

Providing you have connected the big pot the same way as the little pot was.

Is the markings on this pot 10K A or 10K B?

A is an logarithmic pot which goes full very quickly. If there was a dial on the pot with numbers 1 to 10, anything after 3 would be like 10.

B is a linear pot which is what you need, it works basically where each number like above would be a percentage of total resistance. 3=30%, 5=50%, 7=70% and so on.


----------



## i luvmusic 2

trolldragon said:


> Hey ILM2,
> 
> Providing you have connected the big pot the same way as the little pot was.
> 
> ...


 
 Hi TD,
    The Pot is mark B10K and i connected it like the old one was.THANK YOU!


----------



## TrollDragon

i luvmusic 2 said:


> Hi TD,
> The Pot is mark B10K and i connected it like the old one was.THANK YOU!


Then there is something not quite correct in either how you wired it or if it is an old pot salvaged from an old radio they had changed the A / B designation quite a few years ago.

The best way to tell if it is a linear pot is to unsolder it completely. Measure both outside lugs, this should give you roughly 10K ohms. Then turn the shaft approximately half way and you should measure 5K ohms between the center and each of the outside lugs. If the measurement is drastically different between the center and each outside lug, you have a logarithmic pot that will not work.

Also check the pinout of the trimpot you removed by looking it up on the net and make sure you have the wires to the big pot in the same configuration. Only if the big pot is confirmed to be linear from the first test.


----------



## i luvmusic 2

trolldragon said:


> Then there is something not quite correct in either how you wired it or if it is an old pot salvaged from an old radio they had changed the A / B designation quite a few years ago.
> 
> The best way to tell if it is a linear pot is to unsolder it completely. Measure both outside lugs, this should give you roughly 10K ohms. Then turn the shaft approximately half way and you should measure 5K ohms between the center and each of the outside lugs. If the measurement is drastically different between the center and each outside lug, you have a logarithmic pot that will not work.
> 
> Also check the pinout of the trimpot you removed by looking it up on the net and make sure you have the wires to the big pot in the same configuration. Only if the big pot is confirmed to be linear from the first test.


 
 Hi TD,
       I measured the pot from lug 1 to lug 3 = 9.56K then lug 1 to lug 2=4.11K then lug 2 to lug 3=5.42K.I double checked my connections they look ok pin1 to pin1 pin2 to pin2 pin3 to pin3=by turning the shaft clockwise the reading goes up and if i connect it reverse pin1 to pin3 pin2 to pin2 pin3 to pin1= by turning the shaft counter clockwise the reading goes up.The POTS are brand new from Chinada.THANKS!


----------



## TrollDragon

Well everything sounds correct, don't forget the trimmer pot on the board only goes up a few hundred ohms with each turn of the little screw.

Try turning the big pot very slowly and gradually to see what happens.


----------



## gibosi

Finally got the Sylvania sub-miniature 7963 installed into a 6SN7 base. I don't know why I thought this was a good idea! It was a PITA! So you might want to consider this a short essay in how NOT to build an adapter for these little tubes. lol 
  
 Since the pins in a 6SN7 base are hollow, I guess I thought it would be easy to simply insert the long sub-miniature leads and solder. But since the 6SN7 pins are recessed about an inch into the bottom of the base, it was very difficult to manipulate the leads in such a tight space. I ended up using some thick bare copper wire salvaged out of an old 12 gauge cable of the kind used to wire American buildings. I cut the wire into 1.75 inch sections and soldered them to the ends of the thin wire leads. Next, I wrapped the exposed leads with white electrical tape and labeled each - H, 1K, 2K, and so forth, and then inserted the thick copper wires directly into the hollow pins. A very snug fit, no solder required.
  
 And there you have it: Another ugly masterpiece from yours truly 
  

  
 Listened to Diana Krall - Live in Paris last night. This tube has exceptional transparency, clarity and detail, with a black, black background. Imaging is precise and the stage is wide and deep. Like the Sylvania 6SN7W, vocals are sweet with a touch of warmth, very natural. Highs are extended and airy and the bass is deep, detailed and propulsive. This is right up there with the C3g. Another "endgame" tube to my mind.


----------



## i luvmusic 2

trolldragon said:


> Well everything sounds correct, don't forget the trimmer pot on the board only goes up a few hundred ohms with each turn of the little screw.
> 
> Try turning the big pot very slowly and gradually to see what happens.


 
 Yeah that's what i've been doing turning the shaft very slow one thing i noticed if the input is 12V the pot looks like it's sensitive and if the input is 24V not as sensitive compared to 12V inputs.Again THANK YOU for  your HELP!


----------



## i luvmusic 2

So those miniature tubes are that good i can't wait for mine your adapter looks fine to me whatever works is all good.


----------



## mordy

Hi Gibosi,
  
 Welcome to sub miniature land! I do not have the C3g tubes  but I was very impressed that you found your Sylvania 7963 comparable to the C3g.
  
 Now, I do not have the 7963 either, and it's $20 price and up precludes me from getting it due to my self imposed $8 limit per tube. However, I do have the mighty Raytheon 6832. Instead of using my clumsy set up of two Vectors I realized that I can use the tube mounted in the 9 pin extender on my 6DJ8 breadboard. IMHO it is easier to use it in this way with solderless connections, utilizing insulated 18 gauge solid copper wire as push in pins. Based on our collective experience with jumpers on various tubes I do know that the connections made this way are solid and perhaps superior to soldered connections. Just think of all the tubes that are pushed into tube sockets! Here are pictures:

  

  
 I gave up on using the 6832 tubes as power tubes although it was quite possible, but I was lacking the slam in the bass. Now I am running my trusty RCA 6SN7GTB top heater wire tubes as power tubes, and the Raytheon JAN 6832 as driver.
  
 The sound is excellent with all the accolades you can heap upon it. I am going to paint the leads with nail polish to insulate them, but one grand daughter gave me a bottle of pearlized nail polish and I am afraid that there is metal in it which would defeat it's purpose. Holding out for a different nail polish from another kid.
  
 It would be nice if somebody could compare the 6832 to the 7963. My guess is that they are going to sound similar. If that is true I will easily resist the itch to buy the C3g with all the adapters. (I did see a pair of Lorenz C3g on German Ebay that went for 2.5 Euros + shipping, but I think a lot of German sellers don't ship outside of Europe.)
  
 Cheers,


----------



## hypnos1

kvtaco17 said:


> I shall tempt you no more...
> 
> 
> 
> ...


 
  
 Sorry old fruit....already have a gorgeous glow....:
  

  
 And not only that, but at the risk of repeating myself, I can say that without doubt these 6AS7Gs are giving me a _taste_ of hi-end at a lo-to-mid-end price. NOTHING could have prepared me for the difference they are making. Now my new adapter is well run-in, along with all the other goodies I have described (many times!) the _depth_ of bass (as blew me away on revisiting Dire Straits' track 'Love over Gold') is now as never before...together with its wonderful detail...sheer bliss!
 Can't wait to see what happens when silver wire adapter #2 gets finished, lol!


----------



## philiptw

Hi guys,
  
 So now I have obtained the Mullard 8100 and Voskhod, I was just wondering if upgrading my power tubes from stock to *ELECTRO HARMONIX 6H30Pi *would have any further improvement?
  
 I would really appreciate some subjective and fair comments, as these are costing between 50-60GBP online at the moment.. If they dont make a noticeable difference then I will not rush into buying them.
  
  
 Thanks in advance! 
  
 ps cant make my mind up whether I should use the Mullards or Voskhods as my default tubes... both are good :x


----------



## i luvmusic 2

Hi guys anyone of you familiar with these brand of 6AS7 made by GTC on the base it mark GTC 6AS7G Made in USA.Thanks!


----------



## gibosi

i luvmusic 2 said:


> Hi guys anyone of you familiar with these brand of 6AS7 made by GTC on the base it mark GTC 6AS7G Made in USA.Thanks!


 
  
 I have no idea what GTC means.... I suggest you might have a better chance to get an informed answer if you post in the 6AS7G tube rollers thread. And it would very helpful if you posted a picture so people can see this tube.
  
 http://www.head-fi.org/t/410326/for-6as7g-tube-rollers-here


----------



## i luvmusic 2

gibosi said:


> I have no idea what GTC means.... I suggest you might have a better chance to get an informed answer if you post in the 6AS7G tube rollers thread. And it would very helpful if you posted a picture so people can see this tube.
> 
> http://www.head-fi.org/t/410326/for-6as7g-tube-rollers-here


 
 Thanks G! i did not think about the pictures and the 6AS7 thread.


----------



## gibosi

philiptw said:


> So now I have obtained the Mullard 8100 and Voskhod, I was just wondering if upgrading my power tubes from stock to *ELECTRO HARMONIX 6H30Pi *would have any further improvement?
> 
> I would really appreciate some subjective and fair comments, as these are costing between 50-60GBP online at the moment.. If they dont make a noticeable difference then I will not rush into buying them.


 
  
 My amp is a hybrid, so I have no experience with power tubes. However, buried in the last 400 pages are a number of discussions. I suggest you click on the "Search This Thread" at the top (or bottom) of this page and search for "6H30P". Good luck.


----------



## i luvmusic 2

I'm wondering if those tubes are made by RCA.


----------



## i luvmusic 2

I think those are Russian tubes they look exactly like my russian tubes but i could be wrong.


----------



## TrollDragon

i luvmusic 2 said:


> I'm wondering if those tubes are made by RCA.


I would hazard a guess those were made for the General Transformer Corp.'s PeeWee 25W transmitter from the 30's.

Sold by Rat Shack.
http://www.radioshackcatalogs.com/html/1939/h037.html 
Center of the page.


----------



## i luvmusic 2

trolldragon said:


> I would hazard a guess those were made for the General Transformer Corp.'s PeeWee 25W transmitter from the 30's


 
 For $22 a piece i think it's not bad i've seen some 6AS7 go for $$$ so far this is the cheapest.


----------



## i luvmusic 2

Except the 3pcs. of  RCA 6AS7G  for $26 + the killer shipping that Mikelap won from the auction.


----------



## mordy

Hi philiptw,
  
 IMHO I suggest that you skip the Electro Harmonix 6H30P-i tubes and instead buy a pair of inexpensive Sylvania (or RCA) 6SN7 octal tubes. ( You don't have to go for expensive ones, any Sylvania tube will do). Then you need the proper adapters, and everything is plug and play - no external power supplies needed.
  
 These octals will sound better as power tubes than the EH and even the expensive "super" tubes 6H30-DR. If you look through this blog you will find all the information you need - good luck!


----------



## philiptw

gibosi said:


> My amp is a hybrid, so I have no experience with power tubes. However, buried in the last 400 pages are a number of discussions. I suggest you click on the "Search This Thread" at the top (or bottom) of this page and search for "6H30P". Good luck.


 
  
 Done that already before i posted.
  
 Not a lot of useful things pitching up tho..
  
 EDIT: bit the bullet and went for the 6H30Pi-EH in the end..


----------



## TrollDragon

I tried a pair of 6GU7's as power tubes last night, they didn't sound as good as the 6H30-Pi's, bass fell of dramatically.


----------



## bbmiller

i luvmusic 2 said:


> trolldragon said:
> 
> 
> > I would hazard a guess those were made for the General Transformer Corp.'s PeeWee 25W transmitter from the 30's
> ...


 
https://www.vacuumtubes.net/RES%20Audio%20pages/5998.html what do you think of these?


----------



## hypnos1

i luvmusic 2 said:


> Hi guys anyone of you familiar with these brand of 6AS7 made by GTC on the base it mark GTC 6AS7G Made in USA.Thanks!


 
  
 Hi ilm 2.
  
 WAS going to say :Sure looks like the RCA black- plates to me...the dead giveaway for the Russians are the 2 bottom getters shaped like 'flying saucers', and the deep band of silvering, also on the bottom...
  
 But then I noticed mine have 2 partial (what look like...) 'blinkers' beneath the plates, just as above them...more research needed lol!...


----------



## hypnos1

Hi guys.
  
 Had a question/pointer from Chris J, when I popped over to the MKIV SE appreciation thread, re the case temperature with the 6AS7Gs in full flight.
  
 Well, out came the probe again and (thankfully) things didn't seem too bad - to me, anyway...anyone differ?..viz : 36C after 1 hour, and 39C after 4.5 hrs. And let's face it, that gorgeous glow doesn't come for free, lol!!
  
 And with even more hours on the unit, still no nasty surprises..."long may she prosper!".


----------



## mordy

Hi,
  
 Since I have a self imposed rule of not paying more than $8/tube perhaps I have a different way of shopping Ebay. The other day a pair of RCA(GE?) 6AS7 tubes went for less than $3 incl shipping (I missed the end of the auction), and I bought my one RCA 6AS7 tube for less than $3 incl shipping not long ago.
  
 http://www.ebay.com/itm/MATCHED-PAIR-OF-GE-6AS7G-BLACK-PLATE-TUBES-TEST-88-89-AND-90-90-GUARANTEED-/181412339179?pt=Vintage_Electronics_R2&hash=item2a3d049deb
  
 Here I will share some points how to find the bargains. The first ingredient is patience. Keep on looking. Try to buy from somebody who is selling off his grandfather's radio repair shop stock rather than somebody who is making a living selling on Ebay.
  
 To find out if it is possible to get a real bargain, type in what you are looking for. Bring up the screen; then scroll down on the left and look for a checkbox that says "sold items."
  
 Click on it. You may also want to check another box on the left that says "worldwide" to get the global perspective. After doing this you can see what people actually paid. Don't kick yourself if you see that Tung Sol black glass tube that sold two months ago for $5 that the pros are asking $149 for.
  
 Now you have established a frame of reference. It could be that what you are looking simply isn't available as a bargain. Either take the plunge, or consult rule#1 - patience. Try again later. Maybe you'll pick up a pair of Lorenz (Siemens) C3g tubes for $10 on German Ebay if you can persuade the seller to ship outside Germany. Clicking Worldwide will not bring up all the sellers; only those that ship internationally. Go to Google and type in Ebay UK or Ebay Germany etc to get access to local sellers.
  
 http://www.ebay.de/itm/2x-C3g-Lorenz-Matched-Pair-/360869114154?pt=DE_TV_Video_Audio_Elektronenr%C3%B6hren_Valves&hash=item540579b12a
  
 Which brings us to fundamental rule#2: Communication.
  
 Email the seller and ask, using Ebay messages. If you see a guy selling a bunch of stuff, maybe he has what you want but it isn't listed. Based on experience I would only do business through Ebay and not outside Ebay because of the buyer protection. Ask the guy to put up your tube for the agreed buy it now price and zap it right away.
  
 It may be helpful to use Google translate to communicate with a seller who has trouble understanding English.
  
 OK, now you know what is possible with a little luck. How do you sort through several hundred listings for the item you want?
 Again, type in what you want: Super Unobtanium 6SN7GTQ. Normally, Best Match comes up first. Go to the drop down menu on the top right and click. Select lowest price+shipping. Click on it.
  
 Now you can savor the 99c stores if you are lucky. Just watch out for shipping charges. Scroll down. Your best bargains may not be lowest priced+shipping, but after scrolling down a little further you may find somebody who is selling seven tubes for $9.99 with $4 shipping. What would you rather have? One tube for $6 including shipping, or seven for $14 including shipping?
  
 If somebody has a "Submit best offer" don't be afraid to use it by submitting a real low down offer. Your research will tell you what is reasonable. A good seller may make a reasonable counter offer instead of ignoring you. Or the seller may surprise you with accepting your low ball offer...
  
 Probably you all know this stuff already, but maybe the above could help somebody to get better buys.
  
 Happy tube rolling!


----------



## Nic Rhodes

For the GTCs, Chathams.


----------



## i luvmusic 2

Too bad they are sold i waited too long.


----------



## MIKELAP

bbmiller said:


> https://www.vacuumtubes.net/RES%20Audio%20pages/5998.html what do you think of these?


 
 i bought a pair of Chathams from this seller.they work fine .


----------



## i luvmusic 2

A local vendor have a RCA 6SN7 GTB for $7 but according to him it was tested 59%.So 59% is a life span of the tube?Sorry clearly i don't know anything about Tubes and electronics.


----------



## i luvmusic 2

mordy said:


> Hi,
> 
> Since I have a self imposed rule of not paying more than $8/tube perhaps I have a different way of shopping Ebay. The other day a pair of RCA(GE?) 6AS7 tubes went for less than $3 incl shipping (I missed the end of the auction), and I bought my one RCA 6AS7 tube for less than $3 incl shipping not long ago.
> 
> ...


 
 Thank you for the TIPS!
 I saw a NOS one piece RCA 6080 for $6.99 + shipping $34.99 + Import charged $7.99 then you convert that to CAD $ WOW.


----------



## i luvmusic 2

mikelap said:


> i bought a pair of Chathams from this seller.they work fine .


 
 Hi Mikelap,
     How much was the shipping and other charges?Thank!


----------



## MIKELAP

i luvmusic 2 said:


> Hi Mikelap,
> How much was the shipping and other charges?Thank!


 
 Shipping was $14.00 to Montreal total $54.00 U.S for a pair


----------



## i luvmusic 2

mikelap said:


> Shipping was $14.00 to Montreal total $54.00 U.S for a pair


 
 Thanks!


----------



## mordy

Hi i luvmusic2,
  
 The measurements depend on the reference point of the equipment used to test the tubes. Here is an example from a current Ebay listing:
 If the tube was true NOS it should read 100% or even higher, for example 110%. The two readings correspond to the two triodes in a dual triode tube (in our case right and left channel if used as a driver). In this case the tube measures below acceptable in one channel.
 If the tube has a life span of 3000 to 10000 hours I would not worry if the value is above good. You may have to turn up the volume slightly compared to a 100% tube.
 In summary, you must ask what a "good" value is since each manufacturer is different.
  
General Mutual Transconductance (Gm) Test Results:​ *44/56* Where the Minimum is: *50/50* and the NOS value is: *82/82*
 or
*54/69%* of what a NOS tube should test where the Minimum "good" value is *65%*​
 ​
 ​
 ​
 ​
 ​
 ​
 ​
 ​
 ​


----------



## bbmiller

mordy said:


> If the tube has a life span of 3000 to 10000 hours I would not worry if the value is above good. You may have to turn up the volume slightly compared to a 100% tube.
> In summary, you must ask what a "good" value is since each manufacturer is different.


 
 Do you have a site you could link us to with tube life span specs or predictions?


----------



## bbmiller

mikelap said:


> bbmiller said:
> 
> 
> > https://www.vacuumtubes.net/RES%20Audio%20pages/5998.html what do you think of these?
> ...


 
 Did you see all the brands on that page first and come to the Chathams decision by past experience or review or how?


----------



## gibosi

bbmiller said:


> Did you see all the brands on that page first and come to the Chathams decision by past experience or review or how?


 
  
 Here is a nice review of 6AS7-type tubes.
  
 http://the-key.enix.org/~krystal/review-tube-bottlehead.html
  
 I have had good luck purchasing from www.vacuumtubes.net. That said, I have some doubt about the Mullard 6AS7's for $35. At that price, I am inclined to think they are Russian rebrands, similar to these:
  
 http://www.ebay.com/itm/NOS-NIB-Mullard-USSR-6AS7G-Gray-Plate-UFO-Get-3-Mica-Vacuum-Tube-100-/121317136204?


----------



## mordy

Hi bbmiller,
  
 It is difficult to predict tube life, but it seems to me that the octal tubes often were engineered for a life span of around 10,000 hours."The lifespan of the tube depends a great deal on its operating conditions. In other words, you can probably use up a 6SN7 in 2,000 hours or 10,000 hours, depending upon the choice of current and plate voltage. I think that a standard 6SN7 is rated for something less than 10,000 hours."
  
 Seems that the smaller tubes such as the 6AK5 were engineered to last on average 3,000 hours. Various manufacturers made versions with longer lived heaters rated for 10, 000 hours. Amperex had PQ (Premium Quality) tubes, Mullard Millenium tubes, and GE Five Star tubes, the latter said to be good for 7,500 hours. Russian EV tubes are good for 5,000 hours and DR tubes for 10,000 hours. Russian tubes with suffix -i (6N6P-i) are supposed to last only 500 hours, but I think that means in a stressed environment inside an airplane and not in a home use amp.
  
 Personally, being struck by the tube rolling bug, I cannot remember having a tube that I used up. If a tube stopped functioning it always was because of corrosion - a little scraping of the pins with a pen knife would restore it.
  
 You can google individual tube types and see if you can find the life span mentioned.


----------



## bbmiller

gibosi said:


> I have had good luck purchasing from www.vacuumtubes.net. That said, I have some doubt about the Mullard 6AS7's for $35.


 
 Have you ever bought a 6AS7 from them you were satisfied with? Will they give you all the information on exactly what you're buying so you can research on review places like the one you link to? How where exactly would you get all the information from them if they will give it to you? Does it require it a dialogue with them?


----------



## gibosi

bbmiller said:


> Have you ever bought a 6AS7 from them you were satisfied with? Will they give you all the information on exactly what you're buying so you can research on review places like the one you link to? How where exactly would you get all the information from them if they will give it to you? Does it require it a dialogue with them?


 
  
 I have not purchased a 6AS7 from them, as I do not have an amp that uses this tube. But of course, you can email them directly with your questions:
  
  sales@vacuumtubes.net
  
 Whether or not you will be satisfied with their answers, I cannot say.


----------



## bbmiller

mordy said:


> Personally, being struck by the tube rolling bug, I cannot remember having a tube that I used up. If a tube stopped functioning it always was because of corrosion - a little scraping of the pins with a pen knife would restore it.


 
 I do not know if there is some sort of view thread biased you bring to viewing a thread as lodges this one. But on this thread I have not run across people saying they are rolling tubes per vintage of recording. Do you do things like rolled tubes to listen to your favorite 60s or 70s recordings and have other tubes you use for modern recordings.
  
Also do you have a system of marking your tubes for left and right channels before you remove them. Is there a marker that will withstand the heat tubes make?
  
 Is there a premium contact cleaner recommended by the people on this thread? I mean something like the old spray tuna cleaner you used when televisions had those click to change channels tuners?


----------



## hypnos1

David and Goliath?.... Read on!...
  

  
 Guys...just when I thought I was done with mind-blowing moments in this rolling game, I thought (for a laugh) I'd pop in the cheapo 6HM5s, in place of the C3GSs....and SHOCK, AMAZEMENT, BEWILDERMENT...final proof that the traditionally-held "wisdom" re the power tubes having only slight influence on the final results is *TOTALLY WRONG* - dare I even say it?!
  
 What hit my ears left me dazed, to say the least...expecting to go 'yeuch', I was not prepared for a sound that wasn't actually far off the C3GS's. They _never_ sounded like this with the 6N30P-DRs.
  
 As I am still reeling from the shock, I will have to end here and have a treble espresso (or equivalent). These 6AS7Gs are truly amazing tubes, and have rewritten the book, lol!
  
 So what will the Tesla E88CC (gold grids & pins) do? Probably have me shooting myself!! 
	

	
	
		
		

		
			





. Will keep you posted...


----------



## MIKELAP

bbmiller said:


> Did you see all the brands on that page first and come to the Chathams decision by past experience or review or how?


 
 Yes i saw all the tubes on that page the Chatham tubes seem to be well regarded and for $20.00 each that as much as i want to pay theres the Tung Sol 5998 at $85.00 each that are supposebly better but i probably wouldnt ear the difference anyway. So i only have the affortable 6AS7G tubes like the  Chathams, RCA, and Russian equivalent 6SN5S that are cheap but decent.


----------



## bbmiller

mikelap said:


> bbmiller said:
> 
> 
> > Did you see all the brands on that page first and come to the Chathams decision by past experience or review or how?
> ...


 
 Please bear with me I am trying to understand this tube rolling stuff are you saying you own at least three pairs 6AS7G tubes or their equivalent and are rolling them for some purpose? I mean per headphones or per type of music or per vintage of recording or per something else?


----------



## hypnos1

hypnos1 said:


> David and Goliath?.... Read on!...
> 
> 
> 
> ...


 
  
 OK...it's official...I'm gonna shoot myself!
  
 Having just recovered, thanks to good ol' caffeine, my mind has at last totally blown...the reason...:
  

  
 With the Teslas in the driving seat I'm once again in a mortifying stupor...this is just crazy! These 6AS7Gs take otherwise _very_ good tubes to an entirely new level. On preliminary listening there is now only the slightest difference between the sound from the Teslas and that from the wonderful C3GS. Will need much more testing yet, but it's so close that I cannot really put my finger on the actual differences...perhaps the C3GS does things with a little more delicacy is all I am getting at present. But overall, if the 6AS7Gs had been in place way back then, I would have saved myself a lot of money...aah, this rolling game lol!
 But, of course, these E88CCs have to be adapted - no commercially- made ones available, I think.
  
 And so the saga continues...oh my poor head hurts! 
	

	
	
		
		

		
		
	


	




.


----------



## mordy

Hi bb,
  
 IMHO tube rolling involves finding the tubes or combinations thereof that sound best in _your_ system. The sound signature will affect all music you are playing. There is a consensus what the best tubes are, and within these top tier tubes you have to pick what your personal preference is.
  
 It's not about a certain tube being better for hard rock and another for classical music. It's about a tube/tube combination that makes everything sound right, albeit there are subtle differences between the best sounding ones. (I personally feel that octal tubes match very well with old 78 recordings. However, it could just be the difference between analog and digital recordings.)
  
 Please note that the price of the tube is not related directly to how good it sounds. There are many lesser known inexpensive tubes that beat the hyped up expensive alternatives. In addition, the same tube can cost $5 from one seller, and $35 from another seller - caveat emptor.


----------



## MIKELAP

bbmiller said:


> Please bear with me I am trying to understand this tube rolling stuff are you saying you own at least three pairs 6AS7G tubes or their equivalent and are rolling them for some purpose? I mean per headphones or per type of music or per vintage of recording or per something else?


 
 No special purpose simply because i like to try different tubes to see how they sound,  thats what called tube rolling and as time passes they will get more expensive and rare so you can say i am also stocking up, and collecting those beautiful glass works of art .


----------



## gibosi

bbmiller said:


> Please bear with me I am trying to understand this tube rolling stuff are you saying you own at least three pairs 6AS7G tubes or their equivalent and are rolling them for some purpose? I mean per headphones or per type of music or per vintage of recording or per something else?


 
  
 To sum up what others have said. Tubes manufactured in different factories and at different times sound different. Moreover, everyone has different ears and different gear. And so if follows that some tubes will sound better than others given a particular set of ears and gear. Thus people roll different tubes to try to find the best sound, given their ears and gear.
  


bbmiller said:


> I do not know if there is some sort of view thread biased you bring to viewing a thread as lodges this one. But on this thread I have not run across people saying they are rolling tubes per vintage of recording. Do you do things like rolled tubes to listen to your favorite 60s or 70s recordings and have other tubes you use for modern recordings.
> 
> Also do you have a system of marking your tubes for left and right channels before you remove them. Is there a marker that will withstand the heat tubes make?
> 
> Is there a premium contact cleaner recommended by the people on this thread? I mean something like the old spray tuna cleaner you used when televisions had those click to change channels tuners?


 
  
 Yes, some people roll different tubes depending on the music. I don't. Too complicated.
  
 And no, I can see no reason to ensure that the same tubes are always inserted in the same channel. Again, too complicated and not worth the trouble.
  
 I clean pins mechanically by gently scraping them with a dull knife. I have no experience using premium contact cleaners. Some recommend DeoxIT if you are so inclined.


----------



## i luvmusic 2

mordy said:


> Hi i luvmusic2,
> 
> The measurements depend on the reference point of the equipment used to test the tubes. Here is an example from a current Ebay listing:
> If the tube was true NOS it should read 100% or even higher, for example 110%. The two readings correspond to the two triodes in a dual triode tube (in our case right and left channel if used as a driver). In this case the tube measures below acceptable in one channel.
> ...


 
 Thank You for the info Mordy!


----------



## gibosi

The parts for a more powerful heater power supply arrived today, and I am pleased and relieved that the Tung-Sol/Chatham 5998 lights up and plays. As Mordy and others have noted, these power tubes sound surprisingly good as drivers. However, I notice that the LD 1+ runs pretty hot after a hour or more, so will likely put it away for now until I get an OTL amp. After all, with the Sylvania 7963 and the Siemen's C3g's on hand, it's not as if I don't have any new and interesting tubes to listen to. 
  
 Which reminds me...
  
 As the Sylvania sub-miniature 7963 is considered by some to be the best double triode Sylvania ever made, I decided to compare it to a 1945 Sylvania 6SN7W. In many rankings, the 6SN7W is considered to be one of the top 4 or 5 6SN7's ever made, and it is my reference 6SN7.
  
 I A/B'ed a couple tracks, Diana Krall, 'Devil May Care' on the 'Live in Paris' album, and Alex McMurray, 'One Step Away from the Hole' on the 'I Will Never Be Alone in This Land' album. And I was pleasantly surprised. My impression is that the 7963 sounds very similar to the 6SN7W, and maybe not all that surprising, it seems to be a tad bit quieter. The bass is detailed and propulsive, the highs are very extended and airy, and vocals have what I consider to be the Sylvania "house sound," slightly warm, liquid, smooth and sweet. Moreover, I believe the added quietness enhances transparency, imaging and sense of stage. Of course, I might change my mind over time, but for now, I consider the 7963 to be as good as any tube I have (600 and counting lol).


----------



## sgbwill2

600 tubes holy heck. I'll be returning back home in just over a week where I have had all my newly purchased tubes posted to. Cant wait to try out the c3g's and the 4 pairs of 6SN7's I have purchased. Should be good . Btw do you have any other 6SN7's for reference which you would recommend? I'm sure I will be purchasing more in the future haha


----------



## Nic Rhodes

I have been rolling >25 yrs now and have accumulated over 7000 audio tubes! It gets worse not better.....


----------



## gibosi

sgbwill2 said:


> 600 tubes holy heck. I'll be returning back home in just over a week where I have had all my newly purchased tubes posted to. Cant wait to try out the c3g's and the 4 pairs of 6SN7's I have purchased. Should be good . Btw do you have any other 6SN7's for reference which you would recommend? I'm sure I will be purchasing more in the future haha


 
  
 For someone just getting started with 6SN7's, I think the Tung-Sol "Mouse Ears" is a very good tube, especially for the money, and a good reference.


----------



## gibosi

nic rhodes said:


> I have been rolling >25 yrs now and have accumulated over 7000 audio tubes! It gets worse not better.....


 
  
 Let's see now....  7000 tubes divided by 25 years is 280 tubes a year. I have been rolling for almost two years and have 600 tubes, so it appears that I am right on track! lol


----------



## hypnos1

nic rhodes said:


> I have been rolling >25 yrs now and have accumulated over 7000 audio tubes! It gets worse not better.....


 
  
 Phew!... Think I'd better pack it in right NOW - can't take much more of this mind- scrambling stuff, lol! 
	

	
	
		
		

		
		
	


	




.


----------



## philiptw

Received 6H30Pi by Electro Harmonix today, and paired them with Mullard CV4010 on my LD mk3 - listening with DT880 600ohm..
  
 I am somewhat disappointed because I think the stock power tubes (6H6PI) sounded better in both lows and highs, especially the bass impacts..
  
 Would the 6H30Pi improve with burn in? :-/ 
  
 I also noted that one of my 6H30Pi has a brighter glow on one of the electrode than the other, is that normal?
  
 Additionally, the external ambient buzz sound are more apparent with the 6H30Pi tubes.. is this normal?
 The machine isn't overheating or anything and I cant hear pops/hiss/hum from my headphones.
  
 EDIT: Thanks @mordy


----------



## mordy

Hi philiptw,
  
 Like all tubes, the EH tubes will improve with burn-in. However, the 6N6P-IR will sound better. Even better (much better) results will be obtained with 6SN7 tubes.
  
 It is not uncommon for one tube to glow brighter than the other - it means nothing unless you hear a distinct difference, such as much less volume. It is simply a matter of how the heaters are mounted inside the tube, and some parts may obscure the view a little. Even if one is brighter, it could also be that one of the pins is not making good contact inside the tube socket. A gentle scraping of the pin with a knife will take care of it.
  
 Buzzing sounds and hum are sometimes hard to trace. Make sure that electrical appliances and portable telephones aren't too close to the amp - these things could create electrical interference.


----------



## mordy

Hi sgbwill2,
  
 I have found certain RCA 6SN7GTB tubes sounding very nice. These are not expensive but require a little work to find. These tubes were made in 60's and have a heater wire running horizontally on top of the topmost mica plate. Since many pictures do not show the top heater wire clearly, you have to ask the seller.
  
 Here are a couple of pictures that show the heater wire in action, A RCA tube with the top heater (labeled Hoffman), and a Times Square neon night view.


----------



## i luvmusic 2

Hi,
   Anyone familiar with this site Westubes.com?Thanks!


----------



## i luvmusic 2

Hi Guys,
    I just received my Raytheon JAN-6832 Please show me the PIN Layout for this tube.THANK YOU!


----------



## i luvmusic 2

i luvmusic 2 said:


> Hi Guys,
> I just received my Raytheon JAN-6832 Please show me the PIN Layout for this tube.THANK YOU!


 
 This tube is same as Mordy's tubeThanks!


----------



## kvtaco17

i luvmusic 2 said:


> Hi Guys,
> I just received my Raytheon JAN-6832 Please show me the PIN Layout for this tube.THANK YOU!


----------



## kvtaco17

Well I jacked that up...
  
  1 = a
  2 = g2
  3 = h
  4 = k
  5 = k''
  6 = h
  7 = g''
  8 = a''
  
 from the above pic...


----------



## kvtaco17

kvtaco17 said:


> Well I jacked that up...
> 
> 1 = a
> 2 = g2
> ...


 
 I use this to find pinouts
  
 http://www.duncanamps.com/tdslpe/index.html


----------



## i luvmusic 2

THANK YOU !


----------



## kvtaco17

I tried lol


----------



## i luvmusic 2

Is this the right way to wire 6832 to 6SN7?
  
 6832                          6SN7
 Pin 1=A                     pin 2
       2=G2                        1
       3=H                          7
       4=K                          3
       5=K"                         6
       6=H                          8
       7=G"                        4
       8=A"                        5
  
 I wired my adapter like this and it's only working with Left channel.


----------



## kvtaco17

i luvmusic 2 said:


> Is this the right way to wire 6832 to 6SN7?
> 
> 6832                          6SN7
> Pin 1=A                     pin 2
> ...


 
 Looks right to me


----------



## gibosi

i luvmusic 2 said:


> Is this the right way to wire 6832 to 6SN7?
> 
> 6832                          6SN7
> Pin 1=A                     pin 2
> ...


 
  
 This looks fine to me. And I am assuming that you remembered that when looking down into the octal base, the pins are numbered 1 -8 counting *counter clockwise*. 
  
 If you are building an adapter similar to mine, the only things I can suggest is to make sure that you don't have any wire leads touching, your solder joints connecting the leads to the 12 gauge wire posts are good, and the posts are making good contact inside the octal base. You might want to pull out your multimeter and check continuity from the octal pin to the wire lead for each element.
  
 Good luck!


----------



## i luvmusic 2

kvtaco17 said:


> Looks right to me


 
  
 Thank You!


gibosi said:


> This looks fine to me. And I am assuming that you remembered that when looking down into the octal base, the pins are numbered 1 -8 counting *counter clockwise*.
> 
> If you are building an adapter similar to mine, the only things I can suggest is to make sure that you don't have any wire leads touching, your solder joints connecting the leads to the 12 gauge wire posts are good, and the posts are making good contact inside the octal base. You might want to pull out your multimeter and check continuity from the octal pin to the wire lead for each element.
> 
> Good luck!


 
 Thank You!


----------



## i luvmusic 2

I'am still having a problem with my miniature adapter still working with left channel only, even i reversed my wiring and using one section at a time or wired right side still just the left channel will play The tube is fine i used each channel separately and it works.It's my wiring that i can't figure out.


----------



## JoeDoe

No luck selling the LD yet so I unpacked it this morning and now I'm considering keeping it again! 
	

	
	
		
		

		
			




  
 Wanting to try the C3G upgrade. Found a  few online for under $50. @gibosi can you chime in on the difference between C3gs, C3g, and C3m?


----------



## i luvmusic 2

I think i found the problem...........


----------



## i luvmusic 2

I finally got it right and this tube (6832) it sounds nice....
	

	
	
		
		

		
		
	


	




.


----------



## gibosi

joedoe said:


> No luck selling the LD yet so I unpacked it this morning and now I'm considering keeping it again!
> 
> 
> 
> ...


 
 C3g that test better than spec are labeled C3g/s in the factory, so both are essentially the same. C3m has 20 volt heaters and a different pinout, so unless you would like to be a pioneer and try these, it might be best to stay with the C3g.


----------



## gibosi

i luvmusic 2 said:


> I finally got it right and this tube (6832) it sounds nice....
> 
> 
> 
> ...


 
  
 Success is sweet.


----------



## i luvmusic 2

Here it is working......


----------



## i luvmusic 2

gibosi said:


> Success is sweet.


 
 Thanks! I wired it reversed looking at the pin numbers on the bottom of the socket i did not realise that i need to flip the socket and it works now so it's all good. again THANK YOU For you guys Help.


----------



## sgbwill2

Thanks on the advice for 6SN7 tubes guys. I'm going to try the 4 pairs I've just bought and see where I go from there.


----------



## philiptw

This is not entirely to do with tube rolling but please do read on..
  
  
 How do you guys carry your Little Dot amp when you are relocating/moving around?
  
 Has anyone tried to look for aluminium hard cases with foam padding to carry these delicate little things safely?
  
 I have been trying to find a hard case for my LD mk3, but hasnt found a suitable solution...


----------



## gibosi

philiptw said:


> How do you guys carry your Little Dot amp when you are relocating/moving around?
> 
> Has anyone tried to look for aluminium hard cases with foam padding to carry these delicate little things safely?
> 
> I have been trying to find a hard case for my LD mk3, but hasnt found a suitable solution...


 
  
 I simply use the box the LD came in, the tubes get put in tube boxes and tossed in a plastic bag with the cables and away I go.


----------



## Nic Rhodes

Re the C3m 20v tube, don"t many little dots have a 20v capability for WE408s built in already?


----------



## gibosi

nic rhodes said:


> Re the C3m 20v tube, don"t many little dots have a 20v capability for WE408s built in already?


 
  
 Yes, the LD 1+ can roll 20v WE408A's, so heater-wise, it could easily handle a pair of C3m's. The major problem would be converting the C3m 8-pin loctal to 6AK5 7-pin miniature, as the pin-outs for the C3m and C3g are different. While an adapter for the C3g is available on eBay, a C3m adapter is not. That said, it is very likely that the eBay vendor happydiy998 might be willing to build a set of adapters for the C3m as well.


----------



## Rossliew

Can the Mk3 handle the same tubes as well, with just an adaptor and no need for an external power supply?


----------



## i luvmusic 2

I'am wondering if the 6832 can be use as a power tubes?


----------



## gibosi

rossliew said:


> Can the Mk3 handle the same tubes as well, with just an adaptor and no need for an external power supply?


 
  
 No, of the current Little Dot's, only the 1+ can roll 20v tubes. However, the MK3 can roll a pair of C3g's without an external power supply. All you need is a pin-adapter.


----------



## gibosi

i luvmusic 2 said:


> I'am wondering if the 6832 can be use as a power tubes?


 
  
 I believe Mordy tried using these as power tubes. You can read about his about his experience a few pages back....


----------



## i luvmusic 2

gibosi said:


> I believe Mordy tried using these as power tubes. You can read about his about his experience a few pages back....


 
 OK THANKS!


----------



## i luvmusic 2

mordy said:


> Hi Gibosi,
> 
> Welcome to sub miniature land! I do not have the C3g tubes  but I was very impressed that you found your Sylvania 7963 comparable to the C3g.
> 
> ...


 
 Or you can use a heat shrink tubing or brush- on electrical tape but this kind of tape can get messy.


----------



## i luvmusic 2

I'am running 6832 power tubes right now and  i gotta say mordy is right about bass however i like it.It sounds clear and the details are nice the way i prefer my music lots of details.


----------



## mordy

Hi I lovemusic2,
  
 Glad you like the 6832 tubes. As with everything else, the sound depends on the associated equipment, and in my case I found the 6832s very good as power tubes, but ultimately lacking in the bass slam and impact.
  
 I am happily using one as a driver, but I went back to my RCA 6SN7GTB tubes as power tubes. In the future I would like to try a pair of 6080 tubes as power tubes, but these require external power supplies since they draw 2.5A each. Once all the parts come in I am going to try and see how it sounds.
  
 I know that there are people on the blog that tried various sub miniature tubes in the past. One such post came from Critical Bill, maybe in 2009, but right now I cannot find his post. Would appreciate it if somebody has information, as well as information on comparisons between different dual triode sub minis.
  
 Somehow the sub miniature tubes do not have the visual appeal of the Coke Bottle tubes, but looks isn't everything!
  




  
  
 These are mighty minis, and really the pinnacle of vacuum tube technology. For those of you who like to travel with the LD amp, they are good for 80,000 feet altitude (commercial air planes fly under 40,000 feet). They can withstand a 500G impact, and 2,5G vibration, as well as nuclear radiation. The amplification factor is 40.
  
 Which one is the best sub miniature tube for the LD MKIII?


----------



## gibosi

mordy said:


> I know that there are people on the blog that tried various sub miniature tubes in the past. One such post came from Critical Bill, maybe in 2009, but right now I cannot find his post. Would appreciate it if somebody has information, as well as information on comparisons between different dual triode sub minis.


 
  
 His handle is Ctritical Bill.


----------



## hypnos1

mordy said:


> Hi I lovemusic2,
> 
> Glad you like the 6832 tubes. As with everything else, the sound depends on the associated equipment, and in my case I found the 6832s very good as power tubes, but ultimately lacking in the bass slam and impact.
> 
> ...


 
  
 Hi mordy.
  
 Your and gibosi's wee wonders certainly sound interesting...would have been SO much easier to adapt than the C3G, viz the DIY version! And also, it seems, would have been a lot cheaper, lol!
  
 Ah well, another of life's "if only's". Mind you, I think they would look a little 'strange' perched in front of the giants...and I am into aesthetics, as w
  
 ell as sound 
	

	
	
		
		

		
		
	


	




.
  
  
 As an update to my previous post, re the E88CCs driving the "coke bottles", it appears I have been granted a reprieve...after their initial "wow" factor, the C3GS still reigns supreme and I have no regrets spending out on them - apart from the price some have been going for! (I was looking for weeks and never had that kind of luck 
	

	
	
		
		

		
		
	


	




.  And am back in love with them even more now I have finished silver wire adapter #2...there is no doubt in _my_ mind that pure silver in as much of the signal path as possible _does_ bring extra benefits...most notably in the treble area - more 'sparkle', and decay to the notes...lovely...
  
 I cannot wait for your comments when you get those 6080s in the hot seat...you are in for one hell of a surprise mordy - if mine is anything to go by...and wouldn't it be great if someone out Far East _did_ make an adapter with the 2 power leads exiting the back...makes for a nice , neat package... :
  
 Ah well, the picture was _supposed_ to end up here, not above...but didn't! Sometimes this site does some VERY strange things lol! Still, am very grateful for it nonetheless.


----------



## mordy

Hi G,
  
 Thanks for the proper spelling - found the post on page #268.


----------



## i luvmusic 2

mordy said:


> Hi I lovemusic2,
> 
> Glad you like the 6832 tubes. As with everything else, the sound depends on the associated equipment, and in my case I found the 6832s very good as power tubes, but ultimately lacking in the bass slam and impact.
> 
> ...


 
 Hi Mordy,
       The 6080 is identical to 6AS7 i beleived by using 2 as power tubes for MK III(which i have) IMO there is nothing special about it except creating a lot of heat for the MK III i'am not comfortable using it as a power tubes on my MK III it gets  too hot.As much i love to push my amp to it's limit i would not bother using it with my amp although it works.Enjoy and Good luck with your 6080!


----------



## mordy

Did you use separate external power supplies?


----------



## i luvmusic 2

mordy said:


> Did you use separate external power supplies?


 
 Yes i did...12A regulator.


----------



## i luvmusic 2

Speaking of power supply how important it is to have a DUMMY LOAD RESISTOR on one of the power rail?


----------



## gibosi

i luvmusic 2 said:


> The 6080 is identical to 6AS7 i beleived by using 2 as power tubes for MK III(which i have) IMO there is nothing special about it except creating a lot of heat for the MK III i'am not comfortable using it as a power tubes on my MK III it gets  too hot.As much i love to push my amp to it's limit i would not bother using it with my amp although it works.Enjoy and Good luck with your 6080!


 
  
 Hypnos1 has been running 6AS7's in his MK IV and his most recent temperature measurements on a critical resistor don't seem overly hot: 
  
 "36C after 1 hour, and 39C after 4.5 hrs"
  
 Have you taken similar measurements in your MK III?


----------



## bbmiller

Do you think you should use these if you choose to go sub mini?

*link 9-pin breadboard / prototype tube socket for DIY experimenting @ ebay*


----------



## i luvmusic 2

gibosi said:


> Hypnos1 has been running 6AS7's in his MK IV and his most recent temperature measurements on a critical resistor don't seem overly hot:
> 
> "36C after 1 hour, and 39C after 4.5 hrs"
> 
> Have you taken similar measurements in your MK III?


 
 No i did not but IMO when touching the case it's too hot to the touch hotter than usual.I don't know about MK IV if they have same resistor rating with MK III and  i'm not willing to open up my MK III again LOL.


----------



## i luvmusic 2

bbmiller said:


> Do you think you should use these if you choose to go sub mini?
> 
> *link 9-pin breadboard / prototype tube socket for DIY experimenting @ ebay*


 
 Yes you can! see gibosi's and Mordy's post or you can refer to mine just used the terminal block as long as the tube leads are long enough to reach those terminal blocks.


----------



## bbmiller

i luvmusic 2 said:


> bbmiller said:
> 
> 
> > Do you think you should use these if you choose to go sub mini?
> ...


 
 I guess then what I am asking that is that prototype board the right size to plug a sub meanie tube into straightaway without doing what you are showing above?
  
 P.S. after looking at your picture I think the one that's right for the minis is linked and pictured below.
  
*7-pin mini breadboard / prototype tube socket for DIY experimenting*


----------



## i luvmusic 2

IMHO 6AS7 as power tubes for MK III is not much of an improvement over 6SN7's .With 6AS7 power tubes less bass but a bit more on detail and soundstage.


----------



## i luvmusic 2

Or it could be less bass because of my 6AS7 (mine is 6H13C)Brand/Manufacturer maybe it depends on tubes brand/manufacturer i could be wrong.
 NOTE: I'am not trying to discourage some of you guys to used 6AS7 as power tubes it's just my opinion.


----------



## i luvmusic 2

bbmiller said:


> I guess then what I am asking that is that prototype board the right size to plug a sub meanie tube into straightaway without doing what you are showing above?


 
 Those socket  are bigger than the minis leads refer to gibosi's and mordy's post a few pages back they've used cutt off solid copper cable to fit on those sockets.


----------



## i luvmusic 2

bbmiller said:


> Do you think you should use these if you choose to go sub mini?
> 
> *link 9-pin breadboard / prototype tube socket for DIY experimenting @ ebay*


 
 IMO if i were to used these proto board for minis i will just solder a solid wire to minis  leads long enough to bend the leads into place and to reach those terminal blocks or push those solid wire into the socket and put insulations to those leads.


----------



## i luvmusic 2

bbmiller said:


> I guess then what I am asking that is that prototype board the right size to plug a sub meanie tube into straightaway without doing what you are showing above?
> 
> P.S. after looking at your picture I think the one that's right for the minis is linked and pictured below.
> 
> *7-pin mini breadboard / prototype tube socket for DIY experimenting*


 
 It all depends on  what type(ie.7,8 or 9 leads)of mini's you are using in my case iam using 6832(8 LEADS).


----------



## gibosi

bbmiller said:


> Do you think you should use these if you choose to go sub mini?
> 
> *link 9-pin breadboard / prototype tube socket for DIY experimenting @ ebay*


 
  
 When I first got the Sylvania 7963, this is exactly what I did. Works fine. The only problem is if you want to roll another tube, not a sub-miniature, you have to completely rewire everything. A PITA. lol 
  
 Edit: This 9-pin socket works fine. Since the 7963 has only 8 leads, terminal #9 is simply not connected.
 Edit2: The Sylvania 7963 and the Raytheon 6832 have the exact same pin assignment.


----------



## hypnos1

i luvmusic 2 said:


> Hi Mordy,
> The 6080 is identical to 6AS7 i beleived by using 2 as power tubes for MK III(which i have) IMO there is nothing special about it except creating a lot of heat for the MK III i'am not comfortable using it as a power tubes on my MK III it gets  too hot.As much i love to push my amp to it's limit i would not bother using it with my amp although it works.Enjoy and Good luck with your 6080!


 
  
 Hi ilm 2.
  
 Strange indeed...the difference in my MKIV SE is quite dramatic...in ALL areas. The 6SN7s (well, my 7N7 & Psvane CV181- TII versions!) may have _appeared_ to be heavier in the bass, but in comparison to the 6AS7Gs it was in fact more like _bloated_ bass...nowhere near as clean, pure or detailed - in my setup, anyway (especially now with pure silver in both adapters, and of course I don't need that extra extender adapter either...both of which will make quite a difference in cleaning up the bass, as well as all the other goodies they bring, lol!).
  
 And as for heat, there is definitely something going on with your amp...mine is nowhere near the "too hot to handle" mark...in fact case temp is just 39C after 4.5 hrs...see below...
  


gibosi said:


> Hypnos1 has been running 6AS7's in his MK IV and his most recent temperature measurements on a critical resistor don't seem overly hot:
> 
> "36C after 1 hour, and 39C after 4.5 hrs"
> 
> Have you taken similar measurements in your MK III?


 
  
 Hi g.
  
 Actually that was the _case_ temp. The resistor's was 59C - still way below the maximum operation value, I believe...
  


i luvmusic 2 said:


> Or it could be less bass because of my 6AS7 (mine is 6H13C)Brand/Manufacturer maybe it depends on tubes brand/manufacturer i could be wrong.
> NOTE: I'am not trying to discourage some of you guys to used 6AS7 as power tubes it's just my opinion.


 
  
 Coupled with my previous remarks, your tubes - either Russian or Chinese - do not (apparently) match up to even the modestly-priced RCAs.
 I repeat...there is something strange going on with your set-up for you not to be noticing a _great_ improvement over the 6SN7s...
	

	
	
		
		

		
			





. I am really sorry you are not getting the same mind-blowing results that I still cannot believe...


----------



## Oskari

gibosi said:


> Yes, the LD 1+ can roll 20v WE408A's, so heater-wise, it could easily handle a pair of C3m's.


 
  
 Even the +150% heater current?


----------



## mordy

Just a little progress progress report on the sub miniature Raytheon JAN 6932. As good as they are, suddenly there is a marked improvement in sound - more of everything. More air, ambiance, treble, bass, detail; you pick the words. Instead as previously "watching" the sound stage, I can now "see into" the sound stage, similar to my experience with the 6AS7GT.
 Usually detailed and analytical is antithetical to sweet and musical, but here? Maybe we finally have both....
  
 Could it be that these little buggers need extended burn-in? I reckon it is around 70-80 hours+ by now. Amazing...




  
 If anybody knows where I can buy a Russian sub miniature tube 6N16G-V ( 6Н16Г-В in Russian)  let me know. According to one source this is the best one.
  
 Otherwise I have my eyes on the 6N16B but I don't know if it is any better than the Raytheon 6832. Seems that the Russian sellers like to sell them in 4-packs or more.
  
 From the Raytheon catalog: "Popular Raytheon  (subminiature) industrial types and improved military versions meet a host of critical applications. Their long life and stability insure optimum performance in guided missiles, computers, communications and radar equipments and radiation measuring instruments. In high temperature and high radiation environments their reliable qualities overcome your most critical problems."
  
 Maybe this tube has overcome the critical problem of merging analytical with musical - end game? Think of it, instead of sitting in a guided missile, this tube is sitting in my hi-fi setup just generating intense listening pleasure.


----------



## gibosi

oskari said:


> Even the +150% heater current?


 
  
 Good point! And I believe so....
  
 Multiplying 20 volts by .125 amps = .2.5 watts. Dividing 2.5 watts by 6.3 volts = .397 amps. By comparison, the C3g draws .37 amps, so quite close. And as a number of us have run 6.3 volt, .45 amp pentodes, such as the 6AH6 / 6485, in the past with no problems, the C3m _should_ be fine.


----------



## CITIZENLIN

I am currently enjoying 6n6p-IR with 6HM5 on my LD IV. I went through 6au6, 6be6, 6dt6a ect.... I thought I was very happy with 6DT6A and 6N6p-IR until I read about 6HM5. How much more would I get out of LD IV by getting 6SN7 as power tube with adapter? Should I get the C3G with adapter first before 6SN7 or get both to get major differences from my current set up. I am asking because my wallet is on little thin side right now. 
  
 1. Get 6SN7 and adapter
 OR
 2. GET C3G and adapter
 What are your opinion on improvement? (percentage wise)
  
  
 Thank you


----------



## Rossliew

I use the 6SN7 (with adaptor) and 6HM5 on my Mk 3 and find improved dynamics, bass and air between instruments..not sure if a similar result would occur with your IV.


----------



## superdux

i have to give a shoutout to the C3G Adapter seller on Ebay :

```
happydiy998
```
 Everything went fine, except there was a crack in the glass base holding the pins in one of the adapters, so they offered a total refund for that adapter if it doesn`t work.They've always answered the same day being kind and polite and they even deducted total postage fee for 4pieces of the adapter.
  
 I got to listen to the C3G's yesterday and listened to 3 albums being Basement on a Hill from Elliott Smith, Magical Mystery Tour from The Beatles and Present Tense from Wild Biests.
 As for the Elliott Smith album i was surprised to hear a 3D image of the strumming of his gitarre.The total frequency spectrum was represented evenly across from highs to lows. Details were very rich and i even heard some talking on the Beatles album, that i have never heard before. I'm not sure if this was the honeymoon effect and hightened senses but i was satisfied with what i heard and will let these tubes be my endgame (haha). My setup was MKIII and my HD650s and already used C3G's.


----------



## gibosi

citizenlin said:


> I am currently enjoying 6n6p-IR with 6HM5 on my LD IV. I went through 6au6, 6be6, 6dt6a ect.... I thought I was very happy with 6DT6A and 6N6p-IR until I read about 6HM5. How much more would I get out of LD IV by getting 6SN7 as power tube with adapter? Should I get the C3G with adapter first before 6SN7 or get both to get major differences from my current set up. I am asking because my wallet is on little thin side right now.
> 
> 1. Get 6SN7 and adapter
> OR
> ...


 
  
 Of course, you are going to want to do both! Of course! 
  
 In my opinion, assigning improvement percentages to options 1 and 2 is very difficult to do, but it is clear that either will make a significant difference. My suggestion is to start with the cheapest option first, which is probably a nice pair of 6SN7's and adapters.
  
 Cheers


----------



## hypnos1

citizenlin said:


> I am currently enjoying 6n6p-IR with 6HM5 on my LD IV. I went through 6au6, 6be6, 6dt6a ect.... I thought I was very happy with 6DT6A and 6N6p-IR until I read about 6HM5. How much more would I get out of LD IV by getting 6SN7 as power tube with adapter? Should I get the C3G with adapter first before 6SN7 or get both to get major differences from my current set up. I am asking because my wallet is on little thin side right now.
> 
> 1. Get 6SN7 and adapter
> OR
> ...


 
  
 Hi C.
  
 gibosi is probably right re the order of things, but I would say -  from my own experience with the IV SE - that the C3G gives a greater percentage improvement. So you _must_ save up for them (or give out hints for birthday etc.!). Unless, that is, you can keep trying to find some for silly money a-la-mordy...but I wish you _good luck_! in that lol...
	

	
	
		
		

		
		
	


	




.


----------



## hypnos1

superdux said:


> i have to give a shoutout to the C3G Adapter seller on Ebay :
> 
> ```
> happydiy998
> ...


 
  
 If that is 'honeymoon effect', then mine must be the longest honeymoon EVER...and I'm not even married!! Mind you, more than 25 years together qualifies me as such, I suppose 
	

	
	
		
		

		
		
	


	




.
  
 And things will improve for you even more as those adapters burn in lol...Actually, superdux, "heightening of the senses" is a VERY apt statement as to what these tubes manage to impart in bucketloads! Am also glad to hear your positive experience with 'happydiy998'...would hate anything to spoil the magic of this tube...


----------



## i luvmusic 2

hypnos1 said:


> Hi ilm 2.
> 
> Strange indeed...the difference in my MKIV SE is quite dramatic...in ALL areas. The 6SN7s (well, my 7N7 & Psvane CV181- TII versions!) may have _appeared_ to be heavier in the bass, but in comparison to the 6AS7Gs it was in fact more like _bloated_ bass...nowhere near as clean, pure or detailed - in my setup, anyway (especially now with pure silver in both adapters, and of course I don't need that extra extender adapter either...both of which will make quite a difference in cleaning up the bass, as well as all the other goodies they bring, lol!).
> 
> ...


 
 Don't really know what to say about my experienced with these 6AS7 power tubes.Today though i received 3pcs of  6080 tubes from RCA,SYLVANIA and GE i will try those tubes and see if there is a difference in sound.Regarding the heat issue i maybe over exaggerated(should not wrote too hot) about that i know it gets hot hotter than usual.


----------



## i luvmusic 2

Ok first few minutes with 6080 RCA and SYLVANIA i noticed a difference in bass these tubes are better than my 6H13C. the soundstage is bigger and  smoother treble IMO that is.I will see after few hours of burn-in.


----------



## i luvmusic 2

Correction i'am using them as driver tubes.


----------



## gibosi

i luvmusic 2 said:


> Correction i'am using them as driver tubes.


 
  
 6AS7-type tubes, used as drivers, do run hot, and very likely, too hot. The LD's driver tube circuitry is designed for tubes drawing .5 amps, at most, so running these 2.5 amp power tubes seems to me, not to be a good idea.
  
 I ran my 5998 for about 30 minutes, just enough to satisfy myself that it was not defective, so that I could give the eBay vendor positive feedback. I do not intend to roll it again until I have an amp designed to use it as a power tube.


----------



## mordy

I have tried seven different 6080 tubes and one 6AS7 tube as _driver_ tubes with a separate 5A power supply and I did not notice anything untoward.
  
 The tubes run hot, but not excessive, and the LD transformer housing feels a little warm (using 6SN7 tubes as power tubes). With other driver tubes drawing less current (0.6A), the LD feels cool to the touch with the 6SN7s,
  
 The best of the 6080 tubes sound quite nice with strong bass performance, and I would like to try them as power tubes when the right pieces arrive.


----------



## i luvmusic 2

Actually 6080 driver tube for MK III and 1+ the amp did not even get warm same as 6SN7 driver tube but with 6H13C driver tube for MK III and 1+ it gets a little warm.Now for 6AS7 power tubes expect your amp to get HOT,Sure it does work for MK III but for how long.


----------



## CITIZENLIN

gibosi said:


> Of course, you are going to want to do both! Of course!
> 
> In my opinion, assigning improvement percentages to options 1 and 2 is very difficult to do, but it is clear that either will make a significant difference. My suggestion is to start with the cheapest option first, which is probably a nice pair of 6SN7's and adapters.
> 
> Cheers


 
  
  
  
  


hypnos1 said:


> Hi C.
> 
> gibosi is probably right re the order of things, but I would say -  from my own experience with the IV SE - that the C3G gives a greater percentage improvement. So you _must_ save up for them (or give out hints for birthday etc.!). Unless, that is, you can keep trying to find some for silly money a-la-mordy...but I wish you _good luck_! in that lol...
> 
> ...


 
  
 Thank you guys for your inputs. My 6SN7 journey just started. I just got myself 3ea. early 50s Sylvania 2 holes bad boy 6SN7GT for  23 USD  .  And ordered  a pair of adapter for 22 USD.  Did I  pay too much or fair price? Wish me luck.
  
 I will have to wait awhile for C3g and adapters. WOW! A pair of adapter cost as much as C3g.


----------



## gibosi

citizenlin said:


> Thank you guys for your inputs. My 6SN7 journey just started. I just got myself 3ea. early 50s Sylvania 2 holes bad boy 6SN7GT for  23 USD  .  And ordered  a pair of adapter for 22 USD.  Did I  pay too much or fair price? Wish me luck.


 
  
 The price you paid for the 6SN7's and adapters sounds very fair to me. I assume your LD has rings around the sockets? If you cannot remove them, you will need two additional 9-pin socket-savers to clear those rings. The base of the 6SN7 adapters is too wide to fit within the rings....


----------



## gibosi

mordy said:


> I have tried seven different 6080 tubes and one 6AS7 tube as _driver_ tubes with a separate 5A power supply and I did not notice anything untoward.
> 
> The tubes run hot, but not excessive, and the LD transformer housing feels a little warm (using 6SN7 tubes as power tubes). With other driver tubes drawing less current (0.6A), the LD feels cool to the touch with the 6SN7s,
> 
> The best of the 6080 tubes sound quite nice with strong bass performance, and I would like to try them as power tubes when the right pieces arrive.


 
  
 I would agree that running these 2.5 amp tubes makes the LD about as hot as when we rolled 6AH6's. However, with the 6AH6's that heat was generated by the *internal LD heaters* and the associated *driver tube circuitry*. With these 6AS7-type tubes, which require external heaters, that same amount of heat is being generated *only by the driver tube circuitry*. And therefore, I have to believe that all the components and circuit board wiring associated with the driver tube are running much hotter than before.
  
 Until someone is willing to open up their LD's and measure the temperature of critical resisters, similar to the testing Hypnos1 did while running 6AS7 as power tubes, I am not willing to take the risk....
  
 Be careful out there....


----------



## CITIZENLIN

gibosi said:


> The price you paid for the 6SN7's and adapters sounds very fair to me. I assume your LD has rings around the sockets? If you cannot remove them, you will need two additional 9-pin socket-savers to clear those rings. The base of the 6SN7 adapters is too wide to fit within the rings....


 
 Hi gibosi
  
 Thank you. There are two screws holding the whole tube guard rings and base plate. Looks like I am good to go as soon as I get my tubes and adapters. This is my very first tube headphone amp. I was never really into headphone until last "black Friday" I got myself HD650 from sennheiser for 300 USD , DT880/600 for 230 USD and LD MK IV from David in Feb of this year. Until then I had Sony MDR 6 for the last 20 years and still alive and kicking but being ignored for last few months. I do have Fisher 500c for last 15 years but not in use for last few years because of humming problem. Now I am thinking about selling it and get a nice headphone amp or should I do restoration??? Decision decision. Fisher takes KT88/7591 tubes . Can we use them in LD? I've never done any TUBE ROLLING on my fisher 500c.


----------



## gibosi

citizenlin said:


> Hi gibosi
> 
> Thank you. There are two screws holding the whole tube guard rings and base plate. Looks like I am good to go as soon as I get my tubes and adapters. This is my very first tube headphone amp. I was never really into headphone until last "black Friday" I got myself HD650 from sennheiser for 300 USD , DT880/600 for 230 USD and LD MK IV from David in Feb of this year. Until then I had Sony MDR 6 for the last 20 years and still alive and kicking but being ignored for last few months. I do have Fisher 500c for last 15 years but not in use for last few years because of humming problem. Now I am thinking about selling it and get a nice headphone amp or should I do restoration??? Decision decision. Fisher takes KT88/7591 tubes . Can we use them in LD? I've never done any TUBE ROLLING on my fisher 500c.


 
  
 The KT88 is a single beam tetrode and it will not work in the LD....  
  
 You might want to simply put new tubes in the Fisher. After 15 years, I would say it is about time....  And as to getting a "nice headphone amp", if you follow Hypnos1's lead, your LD will in fact be a very nice headphone amp.


----------



## Gravit8

Hey guys, I'm looking for suggestions for power tubes on a MKII ... In the guide he doesn't cover them at all.  I've settled on the Voshkod 6ZH1P-EV, and was wondering what manufacturer I should go for for the power tubes.  I was just going to get the Russian 6H6P-I from YenAudioStore figured I'd keep it Russian  Would you guys say these work together, or is there a better power tube set. 
  
_Btw, I did use the search button on this thread, but putting in the terms " power tubes " brought up just about every post on this gigantic thread haha, so sorry if this has already been covered. _


----------



## gibosi

gravit8 said:


> Hey guys, I'm looking for suggestions for power tubes on a MKII ... In the guide he doesn't cover them at all.  I've settled on the Voshkod 6ZH1P-EV, and was wondering what manufacturer I should go for for the power tubes.  I was just going to get the Russian 6H6P-I from YenAudioStore figured I'd keep it Russian  Would you guys say these work together, or is there a better power tube set.


 
  
 Here is  pretty good review of the traditional power tubes for the LD:
  
 http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/3000#post_9823694
  
 Now you should know that a number of folks have begun to use 6SN7's and some believe them to be better.


----------



## Gravit8

gibosi said:


> Here is  pretty good review of the traditional power tubes for the LD:
> 
> http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/3000#post_9823694
> 
> Now you should know that a number of folks have begun to use 6SN7's and some believe them to be better.


 
 Sweet, thanks so much for that link.  So looking over it, he talks about how the 6H30P-EV is faster and more neutral, while the 6N6P-IR sounds " tubier "... Well, I'd be using this amp mostly for Rock from the 70s through 90s.. So I'm a little torn, should I go with the nostalgia sound, or the faster sound?  
Also, just based off of the OP's recommendation I was going with the Voshkod 6ZH1P-EV... Now, I don't know if there's a tube that you guys have found since then that people like more?  Or if there's one that's maybe good with rock? The amp is being paired with a pair of Grado 225is if that means anything.  I'm mostly looking to upgrade the sound of the amp once, I'm not so much interested in having multiple sets of tubes. 
Thanks!


----------



## gibosi

gravit8 said:


> Sweet, thanks so much for that link.  So looking over it, he talks about how the 6H30P-EV is faster and more neutral, while the 6N6P-IR sounds " tubier "... Well, I'd be using this amp mostly for Rock from the 70s through 90s.. So I'm a little torn, should I go with the nostalgia sound, or the faster sound?
> Also, just based off of the OP's recommendation I was going with the Voshkod 6ZH1P-EV... Now, I don't know if there's a tube that you guys have found since then that people like more?  Or if there's one that's maybe good with rock? The amp is being paired with a pair of Grado 225is if that means anything.  I'm mostly looking to upgrade the sound of the amp once, I'm not so much interested in having multiple sets of tubes. 
  
 I have an LD 1+, which is a hybrid, so I really cannot comment on the sound of power tubes.....
  
 Of the EF-95-type tubes, the Voshkod 6ZH1P-EV are among the best. One tube that many people like more is the EI 6HM5, and it is pretty cheap. In the end, the only way to know which tube is your favorite is to try them all! lol  Or at least, you need to try a few. Everyone has different ears and different gear. And everyone has a different preferred sound signature. What one person loves another finds to be blah. So I encourage you to try as many as your wallet will allow. Cheers.


----------



## Gravit8

gibosi said:


> I have an LD 1+, which is a hybrid, so I really cannot comment on the sound of power tubes.....
> 
> Of the EF-95-type tubes, the Voshkod 6ZH1P-EV are among the best. One tube that many people like more is the EI 6HM5, and it is pretty cheap. In the end, the only way to know which tube is your favorite is to try them all! lol  Or at least, you need to try a few. Everyone has different ears and different gear. And everyone has a different preferred sound signature. What one person loves another finds to be blah. So I encourage you to try as many as your wallet will allow. Cheers.


 
 Thanks so much for the help!  Well I can't seem to find any 6N6P-IR tubes on ebay, so I guess that decision made itself haha.
  
 EI 6HM5.  Are these them? http://www.ebay.com/itm/6HM5-6HA5-EC90
 Do I need to worry about balance? I see all these " matched " tubes on ebay, but I read somewhere in this thread that that doesn't really mean much.


----------



## CollectoR13

gravit8 said:


> Sweet, thanks so much for that link.  So looking over it, he talks about how the 6H30P-EV is faster and more neutral, while the 6N6P-IR sounds " tubier "... Well, I'd be using this amp mostly for Rock from the 70s through 90s.. So I'm a little torn, should I go with the nostalgia sound, or the faster sound?
> Also, just based off of the OP's recommendation I was going with the Voshkod 6ZH1P-EV... Now, I don't know if there's a tube that you guys have found since then that people like more?  Or if there's one that's maybe good with rock? The amp is being paired with a pair of Grado 225is if that means anything.  I'm mostly looking to upgrade the sound of the amp once, I'm not so much interested in having multiple sets of tubes.
> Thanks!




Hi gravit! 

After my long abstinence here, i have to say that i found my endgame tubes. 
Many have now found that the Siemens c3gs as driver tube outrule most other tubes in areas like tansparacy and neutrality. 
I also listen to much rock and i have to say, neutrality is not bad for rock at all! It might sound less "interesting" at first, but after a while you notice all the little details you didn't hear before. 
Also the position of the instruments is much better defined. 
So my advice is clear,try to get some c3gs!

As for power tubes, i tried the 6sn7 tubes, which seem to provide extra power and dynamics the amp was missing till then. In combination with the c3g, this is my endgame combo. 
But i might try some 6f8g in the future... Who knows? 


Btw, cheers guys, wasn't online a long time (yeah my profile says other, but everytime i open my smartphone browser, it logs into headfi, even if i don't surf there, so...) 
Cool to see many others to try the c3g!
Did you try the 6f8g's eventually? 
What where the results? 
Haha i missed so much information! XD


----------



## gibosi

gravit8 said:


> EI 6HM5.  Are these them? http://www.ebay.com/itm/6HM5-6HA5-EC90
> Do I need to worry about balance? I see all these " matched " tubes on ebay, but I read somewhere in this thread that that doesn't really mean much.


 
  
 Those are the ones. And in my opinion, spending extra to purchase "matched pairs" for LD driver tubes is a waste of money. As long as they were made in the same factory at about the same time, they will be fine.


----------



## CITIZENLIN

gibosi said:


> The KT88 is a single beam tetrode and it will not work in the LD....
> 
> You might want to simply put new tubes in the Fisher. After 15 years, I would say it is about time....  And as to getting a "nice headphone amp", if you follow Hypnos1's lead, your LD will in fact be a very nice headphone amp.


 
 May be I should get new set of tubes for the Fisher. I do like my LD MK IV a lot before I got into tube rolling fever. What are your have your favorite " BUDGET 6SN7s"?


----------



## CollectoR13

gibosi said:


> Those are the ones. And in my opinion, spending extra to purchase "matched pairs" for LD driver tubes is a waste of money. As long as they were made in the same factory at about the same time, they will be fine.




Absolutely right, i've made the same experience. 
To gravit: have fun with those 6hm5, they will sure be a upgrade from the voskhods (which i also had and loved, till i upgraded lol)! 
But remember, these are also more neutral than the voskhods, so they might sound not as exciting at first, but keep burning them in and listen to them some hours, they will get better and better with time. 
I also experienced that with my change from the voskhods to the c3g.


----------



## CollectoR13

citizenlin said:


> May be I should get new set of tubes for the Fisher. I do like my LD MK IV a lot before I got into tube rolling fever. What are your have your favorite " BUDGET 6SN7s"?



I have some sylvania black plates from 50s with 3 holes on one side and 2 on the other which are sounding perfect! 
Got them for around 30$

Here is a link of how they look like and a review: http://www.tubemaze.info/sylvania-6sn7gt-black-flat-plates/


----------



## CITIZENLIN

gravit8 said:


> Thanks so much for the help!  Well I can't seem to find any 6N6P-IR tubes on ebay, so I guess that decision made itself haha.
> 
> EI 6HM5.  Are these them? http://www.ebay.com/itm/6HM5-6HA5-EC90
> Do I need to worry about balance? I see all these " matched " tubes on ebay, but I read somewhere in this thread that that doesn't really mean much.
 
 Hi Gravit8
  
 I recently purchased 6n6p-IR from ebay.
  
 http://www.ebay.com/itm/6N6P-IR-ECC99-E182CC-Matched-Pair-High-DurableDoubleTriode-Gold-Grid-NOS-OTK-/171310973012?pt=Vintage_Electronics_R2&hash=item27e2ee0054


----------



## gibosi

citizenlin said:


> May be I should get new set of tubes for the Fisher. I do like my LD MK IV a lot before I got into tube rolling fever. What are your have your favorite " BUDGET 6SN7s"?


 
  
 My favorite "BUDGET 6SN7's":
  
 Tung-Sol, Sylvania, Raytheon, and for a fuller, warmer sound, RCA


----------



## Gravit8

collector13 said:


> Hi gravit!
> 
> After my long abstinence here, i have to say that i found my endgame tubes.
> Many have now found that the Siemens c3gs as driver tube outrule most other tubes in areas like tansparacy and neutrality.
> ...


 
 Those do sound nice, but I don't think I'll be looking in that price range for a little bit, I wana try some of the cheaper tubes first ^.^
 Interesting on the 6sn7 tubes, they're pretty reasonable as well.  Is there a recommended brand or anything?  How are these > ? http://www.ebay.com/itm/2-MATCHED-BLACK
 Thanks for the help!


----------



## hypnos1

gravit8 said:


> Thanks so much for the help!  Well I can't seem to find any 6N6P-IR tubes on ebay, so I guess that decision made itself haha.
> 
> EI 6HM5.  Are these them? http://www.ebay.com/itm/6HM5-6HA5-EC90
> Do I need to worry about balance? I see all these " matched " tubes on ebay, but I read somewhere in this thread that that doesn't really mean much.
 
  
 Hi Gravit8.
  
 Ditto re gibosi's comments...plus I and a few others got these 6HM5s from this seller - btw, I offered $5 ea and he accepted! These are hard to beat as a (cheap) straight replacement, on EF95 setting.
 But if you can beg, steal or borrow the necessary $, as Collector13 said you should try for the C3G - this tube (or the 'S' version if the price is right) is streets ahead of the 6HM5. And now there are adapters available on ebay (admittedly not cheap), it is an option for those who are not into much DIY, lol! I have been plugging this tube for a long while now, and thankfully all who have tried it have sung its praises. It takes the LD to a whole new level. And even more so if you can go the route of 6SN7 as power tube...again there are adapters available on ebay.


----------



## Gravit8

hypnos1 said:


> Hi Gravit8.
> 
> Ditto re gibosi's comments...plus I and a few others got these 6HM5s from this seller - btw, I offered $5 ea and he accepted! These are hard to beat as a (cheap) straight replacement, on EF95 setting.
> But if you can beg, steal or borrow the necessary $, as Collector13 said you should try for the C3G - this tube (or the 'S' version if the price is right) is streets ahead of the 6HM5. And now there are adapters available on ebay (admittedly not cheap), it is an option for those who are not into much DIY, lol! I have been plugging this tube for a long while now, and thankfully all who have tried it have sung its praises. It takes the LD to a whole new level. And even more so if you can go the route of 6SN7 as power tube...again there are adapters available on ebay.


 
 Thanks for the advice!  The ones I saw on ebay were about $70 for two? Does that sound right?
So you'd need an adapter for the C3G, but not the 6SN7, correct? EDIT : nevermind, I found the answer earlier in the thread.


----------



## gibosi

gravit8 said:


> Thanks for the advice!  The ones I saw on ebay were about $70 for two? Does that sound right?
> So you'd need an adapter for the C3G, but not the 6SN7, correct? EDIT : nevermind, I found the answer earlier in the thread.


 
  
 About $70 for a pair seems to be the going price these days. And here is an earlier post to help you get started:
  
 http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/6000#post_10512665


----------



## hypnos1

Yet _another_ update on the 6AS7G as power tube saga...sorry folks!
  
 Just as I thought the C3G had delivered all the splendour it could, once again I am in total awe...replaced the RCAs with a pair of Chathams (= Tung Sol), and even _more_ lovely rich bass, plus extra detail all round. A true match made in heaven. And at $20 ea from vacuumtubes.net, a VERY reasonable buy (thanks, gibosi!)...I think I may actually now have achieved total end-game - after a good few of them lol!
  
 ps. Get yourselves a MKIV SE guys and be done with it!! MERRY CHRISTMAS  
	

	
	
		
		

		
			





.


----------



## gibosi

gravit8 said:


> Interesting on the 6sn7 tubes, they're pretty reasonable as well.  Is there a recommended brand or anything?  How are these > ? http://www.ebay.com/itm/2-MATCHED-BLACK


 
  
 For those just getting started with 6SN7's:
  
 head-fi 6SN7 reference thread
  
 http://www.head-fi.org/t/117677/the-reference-6sn7-thread
  
 head-fi 6SN7 identification thread
  
 http://www.head-fi.org/t/209782/the-6sn7-identification-guide


----------



## Gravit8

gibosi said:


> Those are the ones. And in my opinion, spending extra to purchase "matched pairs" for LD driver tubes is a waste of money. As long as they were made in the same factory at about the same time, they will be fine.


 
 Is there anything I should do with the seller asking for tubes from the same box/date?  I figure no matter what tubes I might get in the future, I'd pick these up, they're so cheap!


----------



## MIKELAP

gravit8 said:


> Is there anything I should do with the seller asking for tubes from the same box/date?  I figure no matter what tubes I might get in the future, I'd pick these up, they're so cheap!


 
 Heres a link for 6N6PIR tubes they are $13.00 each + shipping from Russia               http://tubes-store.com/index.php?cPath=30_78&page=2


----------



## CITIZENLIN

gibosi said:


> For those just getting started with 6SN7's:
> 
> head-fi 6SN7 reference thread
> 
> ...


 

 Thanks gibosi. Haha I did read them and yet still asking questions here. Do you have suggestion on c3g, c3gs ? source and reasonable prices?? buy a set or buy 4 to save few bucks?


----------



## Gravit8

> Originally Posted by *gibosi* /img/forum/go_quote.gif
> 
> For those just getting started with 6SN7's:
> head-fi 6SN7 reference thread
> ...


 
  
 Alright, I'll get reading. Thanks!
  


> Originally Posted by *CITIZENLIN* /img/forum/go_quote.gif
> 
> Hi Gravit8
> I recently purchased 6n6p-IR from ebay.
> http://www.ebay.com/itm/6N6P-IR-ECC99-E182CC-Matched-Pair-High-DurableDoubleTriode-Gold-Grid-NOS-OTK-/171310973012?pt=Vintage_Electronics_R2&hash=item27e2ee0054


 
  
 Thanks for the link! I must have missed this somehow.
 ---
 Sorry for noobing up this thread, thanks for all the info and direction everyone! It's easy to get lost in here haha


----------



## gibosi

citizenlin said:


> Do you have suggestion on c3g, c3gs ? source and reasonable prices?? buy a set or buy 4 to save few bucks?


 
  
 Again $70 for a pair seems to be the going price these days. So if you can find them for less, that might be a good deal.
  
 As best I can tell, all C3g's were made by Siemens, so it doesn't matter which brand you get, Siemens, Telefunken, Valvo or Lorenz. Further, these tubes are rated for 10,000 hours, so a pair will probably last longer than your amp. If you can afford 4, you would be set for life.


----------



## mordy

Hi Gravit 8,
  
 IMHO tubes that sound good or great, sound good with any kind of music; it doesn't matter classical or rock, so go for the best sounding ones.
  
 If the objective is to get the biggest bang for the buck, go with the subminiature Raytheon 6832 and a pair of Sylvania or RCA 6SN7 tubes. These tubes you should be able to get for around $20 total. Then you need adapters and possibly extenders. I am waiting for someone to compare the 6832 to the C3g - wouldn't be surprised if they come close.
  
 Read the later posts on the blog and you will find all the info that you will need. Good Luck!


----------



## CITIZENLIN

gibosi said:


> Again $70 for a pair seems to be the going price these days. So if you can find them for less, that might be a good deal.
> 
> As best I can tell, all C3g's were made by Siemens, so it doesn't matter which brand you get, Siemens, Telefunken, Valvo or Lorenz. Further, these tubes are rated for 10,000 hours, so a pair will probably last longer than your amp. If you can afford 4, you would be set for life.


 
 Thanks gibosi. Do you think I can use C3g on my Fisher  500c? I think Fisher use 12AX7 for preamp. You got me all excited about Fisher 500c again which been collecting dust for few years.


----------



## CITIZENLIN

mordy said:


> Hi Gravit 8,
> 
> IMHO tubes that sound good or great, sound good with any kind of music; it doesn't matter classical or rock, so go for the best sounding ones.
> 
> ...


 
 OH .. NO  6832???? more reading for " the biggest gang for the buck" hahahaha I am on it.


----------



## gibosi

citizenlin said:


> Thanks gibosi. Do you think I can use C3g on my Fisher  500c? I think Fisher use 12AX7 for preamp. You got me all excited about Fisher 500c again which been collecting dust for few years.


 
  
 The 12AX7 has a gain of about 100, while the C3g has a gain of about 40, so I doubt it would work without serious modification...


----------



## i luvmusic 2

I only have 3 hours using these 6080(driver) and they are getting better each passing time.the soundstage opens up  the treble it gets smoother and that bass is deep.My DT880 is loving that deep bass and the smooth treble.


----------



## Gravit8

mordy said:


> Hi Gravit 8,
> 
> IMHO tubes that sound good or great, sound good with any kind of music; it doesn't matter classical or rock, so go for the best sounding ones.
> 
> ...


 
 Good to know on the tube sound, wasn't sure if different tubes worked with different genres better, but this clears it up.
 So it seems like as far as stock tube sizes go, everyone seems to really like the 6HM5 correct?  Then after that for end game sort of stuff Raytheon 6832 on the cheap, and C3g for best overall? Thanks!


----------



## gibosi

gravit8 said:


> Good to know on the tube sound, wasn't sure if different tubes worked with different genres better, but this clears it up.
> So it seems like as far as stock tube sizes go, everyone seems to really like the 6HM5 correct?  Then after that for end game sort of stuff Raytheon 6832 on the cheap, and C3g for best overall? Thanks!


 
  
 IMHO, C3g's are not alone at the top as the best overall. If someone does not want to mess with double triodes, which typically require an external socket, 7-pin Vector socket-savers and an external power supply, then in my opinion, a pair of C3G's is clearly "end-game". But in order to use the Raytheon 6832, which is after all, a double triode, an external socket and Vectors are required. And if you have gone that far, you may as well set up an external power supply. Once everything is properly setup, there are a number of 6SN7's, E80CC's, E88CC's, and some of the other sub-miniatures, such as the Sylvania 7963, which rival the C3g's.
  
 So, if someone wants a simple and relatively clean and neat "end-game" rig, C3g's are the only game in town. If someone is willing to deal with the messiness of external sockets, power supplies and such, the universe of "end-game" tubes is much larger.


----------



## CITIZENLIN

gibosi said:


> IMHO, C3g's are not alone at the top as the best overall. If someone does not want to mess with double triodes, which typically require an external socket, 7-pin Vector socket-savers and an external power supply, then in my opinion, a pair of C3G's is clearly "end-game". But in order to use the Raytheon 6832, which is after all, a double triode, an external socket and Vectors are required. And if you have gone that far, you may as well set up an external power supply. Once everything is properly setup, there are a number of 6SN7's, E80CC's, E88CC's, and some of the other sub-miniatures, such as the Sylvania 7963, which rival the C3g's.
> 
> So, if someone wants a simple and relatively clean and neat "end-game" rig, C3g's are the only game in town. If someone is willing to deal with the messiness of external sockets, power supplies and such, the universe of "end-game" tubes is much larger.


 

 Thank you very much for your explanation. How do I go about setting up the external power supply.  Is there a step by step explanation on that on this thread?


----------



## gibosi

citizenlin said:


> Thank you very much for your explanation. How do I go about setting up the external power supply.  Is there a step by step explanation on that on this thread?


 
  
 These postings will get you started. And if you have any questions, just let us know.
  
 http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/5760#post_10435226
  
 http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/5760#post_10432434
  
 http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/4410#post_10076232


----------



## CITIZENLIN

gibosi said:


> These postings will get you started. And if you have any questions, just let us know.
> 
> http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/5760#post_10435226
> 
> ...


 
 Thank you. More reading. I feel like I am back in school. Thanks again ... I am off to study (reading).


----------



## Rossliew

gravit8 said:


> Good to know on the tube sound, wasn't sure if different tubes worked with different genres better, but this clears it up.
> So it seems like as far as stock tube sizes go, everyone seems to really like the 6HM5 correct?  Then after that for end game sort of stuff Raytheon 6832 on the cheap, and C3g for best overall? Thanks!


 
 6HM5 is very good for the money you pay for them. The Voshkods are also good but then it depends on your set up and the music you listen to. For me, i love my metal tunes and bass so any tube which gives me good bass, i will love them. Thus far, I've had several pairs of generic 6AK5 tubes and RTCs which all sound relatively good. The Voshkods and 6HM5s have very good bass but if you want to move a notch up, the 6SN7 as power tubes will help a lot. After listening with 6SN7s, i cannot return to the stock power tubes as I feel everything seems to have tuned down a notch in terms of dynamics, clarity, bass, etc. And it's a plug and play affair without the need for an external power supply (just need a pair of adaptors). 6SN7s can be had relatively cheap all over eBay so there you go - have fun !


----------



## hypnos1

gibosi said:


> IMHO, C3g's are not alone at the top as the best overall. If someone does not want to mess with double triodes, which typically require an external socket, 7-pin Vector socket-savers and an external power supply, then in my opinion, a pair of C3G's is clearly "end-game". But in order to use the Raytheon 6832, which is after all, a double triode, an external socket and Vectors are required. And if you have gone that far, you may as well set up an external power supply. Once everything is properly setup, there are a number of 6SN7's, E80CC's, E88CC's, and some of the other sub-miniatures, such as the Sylvania 7963, which rival the C3g's.
> 
> So, if someone wants a simple and relatively clean and neat "end-game" rig, C3g's are the only game in town. If someone is willing to deal with the messiness of external sockets, power supplies and such, the universe of "end-game" tubes is much larger.


 
  
  


rossliew said:


> 6HM5 is very good for the money you pay for them. The Voshkods are also good but then it depends on your set up and the music you listen to. For me, i love my metal tunes and bass so any tube which gives me good bass, i will love them. Thus far, I've had several pairs of generic 6AK5 tubes and RTCs which all sound relatively good. The Voshkods and 6HM5s have very good bass but if you want to move a notch up, the 6SN7 as power tubes will help a lot. After listening with 6SN7s, i cannot return to the stock power tubes as I feel everything seems to have tuned down a notch in terms of dynamics, clarity, bass, etc. And it's a plug and play affair without the need for an external power supply (just need a pair of adaptors). 6SN7s can be had relatively cheap all over eBay so there you go - have fun !


 
  
 Hi gibosi and Rossliew.
  
 Nicely summed up for the majority of LD lovers...
	

	
	
		
		

		
		
	


	




.


----------



## CollectoR13

Exactly!


----------



## hypnos1

collector13 said:


> Hi gravit!
> 
> After my long abstinence here, i have to say that i found my endgame tubes.
> Many have now found that the Siemens c3gs as driver tube outrule most other tubes in areas like tansparacy and neutrality.
> ...


 
  
 Hi CR13.
  
 Good to see you back again...HOWEVER...do you have the MKIV?...can't remember - one of the joys(?!) of getting old... Please don't give up on 'end-game' _just_ yet...perhaps you've caught my (endless!) rantings re the 6AS7G as power tubes - endless because they really do take the IV especially to another level. And as I believe you have managed to make your own adapters in the past, the mod needed to provide these tubes with 2.5A each is a piece of cake...and it can be done using the 6SN7 adapter, lol! The pairing with the C3GS is just out of this world...it is almost criminal (!!) _not_ to treat the MKIV in this way - not to mention _yourself..._so, perhaps a project to bear in mind? I guarantee you would not regret it...I'm still on cloud nine with every piece of music I throw at the combo...
  
 Rant over (once again!)...
  
 Happy rolling.


----------



## CollectoR13

hypnos1 said:


> Hi CR13.
> 
> Good to see you back again...HOWEVER...do you have the MKIV?...can't remember - one of the joys(?!) of getting old... Please don't give up on 'end-game' _just_ yet...perhaps you've caught my (endless!) rantings re the 6AS7G as power tubes - endless because they really do take the IV especially to another level. And as I believe you have managed to make your own adapters in the past, the mod needed to provide these tubes with 2.5A each is a piece of cake...and it can be done using the 6SN7 adapter, lol! The pairing with the C3GS is just out of this world...it is almost criminal (!!) _not_ to treat the MKIV in this way - not to mention _yourself..._so, perhaps a project to bear in mind? I guarantee you would not regret it...I'm still on cloud nine with every piece of music I throw at the combo...
> 
> ...




Hi hypnos! 
No, i have the mkiii. 
I might try some 6as7g in the future, but for now, i seriously don't feel the need to upgrade any part of my system. 
It sounds just perfect to me, i can get lost in the music for hours lol! 
Btw, did i post some pictures of my adapter? 
Don't remember, all before my exams haha lol...


----------



## hypnos1

collector13 said:


> Hi hypnos!
> No, i have the mkiii.
> I might try some 6as7g in the future, but for now, i seriously don't feel the need to upgrade any part of my system.
> It sounds just perfect to me, i can get lost in the music for hours lol!
> ...


 
  
 Hi again CR13.
  
 Am really glad you are so happy with your sound - that's all that counts in the end...as gibosi and mordy would espouse!
  
 Things are still in the air re use of 6AS7G (6080) in the MKIII - ilm2 didn't seem to get the same magic as myself, but we await with eagerness (well *I* do anyway, lol!) mordy's findings when he finally gets all his bits 'n pieces...
  
 Can't remember if I saw your photos either...and BTW I hope all went well with your exams 
	

	
	
		
		

		
			





.


----------



## hypnos1

Slightly off topic - but not really, as we're all trying to wring the last ounce out of our LDs, no?...  I have had confirmation of something I commented on some good while back, and which was endorsed by Audiofanboy - one of our star contributors, before he got 'lost' somewhere in Japan! - regarding mains conditioners. Basically, until I received my new power supply and higher-rated voltage regulator for the 6AS7Gs (the bench DC power supply didn't materialise in the end), the originals were plugged directly into the mains...with no untoward mains nasties.
 But the new power supply (a 12V 6A laptop-like unit, marketed as an led string light supply) I plugged into my 6-outlet mains conditioner, and either my hearing has suddenly taken a turn for the better (highly unlikely!) or the already amazing sound went up yet another notch - to a degree I really wasn't expecting, even though I am a big fan of a _decent_ conditioner, not just for audio but video also...
 There was a noticeable enhancement of 'smoothness' to the overall sound -  without any loss of 'sparkle' - and a greater crispness to notes, from initial attack thru decay, plus even clearer detail separation/positioning...and everything through an even 'blacker' background than before.
 And so now I'm an even _bigger_ fan of 'cleaning' the mains supply, lol!
  
 addendum...When you see the size of those heaters in these tubes, perhaps it's no surprise that a 'clean' supply is going to reap benefits! 
	

	
	
		
		

		
		
	


	




.


----------



## TrollDragon

Hmmm... starting to sound a little too much like the Sound Science "Fiction" threads...

If you tell us the the fuse in the LD or the Power Cord needs to be changed to "Audiograde" next, then I'm outta here... :rolleyes:


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## CollectoR13

trolldragon said:


> Hmmm... starting to sound a little too much like the Sound Science "Fiction" threads...
> 
> If you tell us the the fuse in the LD or the Power Cord needs to be changed to "Audiograde" next, then I'm outta here... :rolleyes:




I tried fuses myself, they make subtile difference, but increase transparancy a bit. But i got them for free, i would never pay so much for such a subtile change, maybe it was only autosuggestion? 
So i am definitely not a "fuse-believer" lol

And re power cables, the only power cable that made a difference was changing my main amplifiers power cable to thick solid core cable which improved dynamics quite a bit. Tried other cables for my cd transport and the little dot, but they didn't differ so much from stock, that it justifies the price tag. Maybe i diy some in the future, but for now..... No!


----------



## i luvmusic 2

Regarding power supply i tried a few my self(recycled not willing to pay for them)and what i found out is some of them(AC to DC adapters not include desktop PS)it have a very slight hum and it is hard to hear/notice unless you put the adapter against your ear and at that time i was blaming my tubes for a slight hum only to find out it was the adapter causing the hum not the tubes until i found a nice quiet Desktop PS that i don't even know i have it installed in my old PC long time ago and these one is very quiet i was surprised how quiet the fan is.Those tubes that was slightly humming i reused them with these new desktop PS i found and  they are quiet  these is the deference i found about PS.Regarding sound i did not hear any deference.So if your tube is humming check your PS for any slight noise it may help,maybe in these case those Power conditioner will help.


----------



## gunnerwholelife

Hey guys will ld mk ii work well with hd650 + dt880 ?
 I just want to get the feel of a warm tube amp.
 How much of a difference is there between mk ii vs mk iii ?
  
 Also I have the following tubes :-
 6hm5 + 6n6p.
 Will they work with ld mk ii ?
  
 Let me know.
 Thanks.


----------



## sgbwill2

mk iii works well with the 650's (though isnt the warmest sound ever with stock tubes)
  
 On a side note ive just used my 6sn7 tubes for the first time and am getting a lot of distortion when playing my headphones at high volumes. is anyone else getting this problem? and what would you expect the solution to the problem to be? thanks
  
 edit: normal listening levels distortion is not as much a problem except the base is flappy still though mids and highs aren't distorted unlike at the high volumes


----------



## hypnos1

trolldragon said:


> Hmmm... starting to sound a little too much like the Sound Science "Fiction" threads...
> 
> If you tell us the the fuse in the LD or the Power Cord needs to be changed to "Audiograde" next, then I'm outta here...


 
  
 Hmmm...when my other half even notices improvements in sound and vision from the TV, let alone _proper_ audio equipment (and she, bless her, doesn't even know what 'frequency response' means), then I think there must be _some_ element of truth in it, lol!...probably depending on what is happening within one's own particular mains supply?
  
 Anyway, TD, all I can say is there was a _definite_ improvement in sound when the plug went into the conditioner...perhaps I have more than average gremlins living in my mains! (Now I think about it, I could always install a dedicated mains supply to the hi-fi system, complete with ground out to a spike in the garden...even a 'balanced' mains unit ($$$$?)...
	

	
	
		
		

		
		
	


	




...then again...!!
  
 ps...Funny you should mention hi-grade fuses


----------



## gibosi

gunnerwholelife said:


> Hey guys will ld mk ii work well with hd650 + dt880 ?
> I just want to get the feel of a warm tube amp.
> How much of a difference is there between mk ii vs mk iii ?
> 
> ...


 
  
 Both the mk ii and mk iii are tube OTL amps and either can easily drive both of these headphones.
  
 As far as the differences between the two amps, I believe the quality of components in the mk iii is superior, but I suspect that any sonic differences are likely very small. That is, I am unaware of anyone reporting that the iii sounds better. As I have no experience with either of these amps, perhaps others who do will chime in.
  
 And yes, the current versions of these amps use the same tubes.


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## mordy

Little quiet on the blog - probably everybody has found their end game tubes and are basking in sonic bliss...LOL
  
  
 Anyhow, here is an update on the mighty subminiature 6832 tube. It continues to amaze as a driver tube. I did a lot of listening using my Audio Technica ATH-AD700 head phones and after an extended burn in it turned out to be an excellent match.
  
 After switching to listening through speakers there was a certain brightness that bothered me. I could turn down the treble but then I lost some of the detail in the treble. Decided to switch out the RCA 6SN7GTB power tubes for a near pair of Sylvania 6SL7WGT. The 6SL7 tubes impart a certain fleetness and quickness that is very pleasing, but the ultimate heft and slam was missing. The brightness was less pronounced, though.
  
 What's next to try? All my octals have served duty as driver tubes, and I take notes on little pieces of paper that I stick on the tubes with rubber bands. IMHO a good sounding driver tube makes a good sounding power tube, and it is easier to hear the differences when using the tubes as drivers.
  
 Seems to me that you can mix tubes that sound similar without having to worry about a strange sound field. I picked two tubes that only match in size - both are quite tall: A Channel Master 6SN7GTB from a Famous Japanese Maker (ToTenHiMa) and a Newark, NJ, US made Tung Sol tube of the same designation. Not even a near pair, but a collaboration of the best talents of two continents, or whatever...
  
 The brightness is tamed, and the bass has the appropriate heft. Sounds great! Sweet....
  
 Happy tube rolling!


----------



## i luvmusic 2

My first American made 6AS7G  and My end game for me are these...
 IMO these tubes are far better than my 6H13C and the 6080 tubes have more bass than these Coke Bottle tubes.The vendor sent me a RCA instead of RAYTHEON.


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## i luvmusic 2

mordy said:


> Little quiet on the blog - probably everybody has found their end game tubes and are basking in sonic bliss...LOL
> 
> 
> Anyhow, here is an update on the mighty subminiature 6832 tube. It continues to amaze as a driver tube. I did a lot of listening using my Audio Technica ATH-AD700 head phones and after an extended burn in it turned out to be an excellent match.
> ...


 
 IMO the 6832 is bright.


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## gibosi

I am pleased to report that the Sylvania 7963 keeps getting better and better.


----------



## sgbwill2

Anyone care to comment on whether their 6SN7 tubes also distort at high volumes? and possible solutions? so far not very impressed with these tubes as mids + highs may have improved however there is still bass distortion even at lower volumes. Still yet to try the C3G's as I am waiting for the 7 pin miniature extenders. Hopefully I have better results with the C3G's than the 6sn7's.


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## kvtaco17

sgbwill2 said:


> Anyone care to comment on whether their 6SN7 tubes also distort at high volumes? and possible solutions? so far not very impressed with these tubes as mids + highs may have improved however there is still bass distortion even at lower volumes. Still yet to try the C3G's as I am waiting for the 7 pin miniature extenders. Hopefully I have better results with the C3G's than the 6sn7's.


 
 I never had that issue... at all volume levels my 6SN7's were silent. This was with the LD MK1+.


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## sgbwill2

Thanks for the reply. I must have a problem somewhere then whether its the adapters or the extenders. Doubt its the tubes as I have tried 4 different pairs and all are distorting =/


----------



## kvtaco17

sgbwill2 said:


> Thanks for the reply. I must have a problem somewhere then whether its the adapters or the extenders. Doubt its the tubes as I have tried 4 different pairs and all are distorting =/


 

 Agreed! I would check your grounds... also the DC output of your voltage regulator with an actual voltmeter... the one's with the display like to lie...


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## sgbwill2

Well the stock tubes don't distort at all so that leads me to believe it must be the adaptor or 9 pin extenders for the 6sn7's


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## kvtaco17

I ran an external dc regulator for my 6sn7's... So that may be the difference...


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## gibosi

Are you using an external DC heater power supply? If not, you are likely exceeding the LD's internal heater power supply capacity. Probably not safe.... 
  
 And if you are using an external heater power supply, have you tied the negative out to a chassis screw on the amp?
  
 Also....  are you using 6SN7's as drivers? Or as power tubes?


----------



## sgbwill2

Been running the 6sn7's now for a few more hours and the distortion has all but disappeared. Strange; seems like whatever was causing the problem has sorted itself out. Still some when playing the amp on full though its only minor and i doubt i'll ever be listening to it at those levels. more than happy now


----------



## sgbwill2

I am not using a external DC heater power supply. amp is cooler than with the stock tubes for some reason. which is good. im using the 6sn7's as power tubes


----------



## tjw321

sgbwill2 said:


> Been running the 6sn7's now for a few more hours and the distortion has all but disappeared. Strange; seems like whatever was causing the problem has sorted itself out. Still some when playing the amp on full though its only minor and i doubt i'll ever be listening to it at those levels. more than happy now


 
 Sounds very similar to a problem I had with another amp. Reseating the tube nearly fixed it for me. Cleaning the contacts and reseating the tube completely fixed it. Maybe one of your connections is a little dodgy?
  
 Incidentally my Little Dot Mk III arrived a few days ago. I haven't done any rolling yet, but I have a pair of Voskhod 6ZH1P-EVs and a pair of Mullard M8100s on the way. Thanks to everyone for all the info in this thread.


----------



## gibosi

sgbwill2 said:


> I am not using a external DC heater power supply. amp is cooler than with the stock tubes for some reason. which is good. im using the 6sn7's as power tubes


 
  
 Used as power tubes, you do not need an external DC heater power supply. The 6SN7 heaters draw only .6 amps whereas the stock power tubes draw around .85 amps, so they do run cooler. However, if you ever decide to run 6SN7's as drivers, you will need an external heater.
  
 And I never give up on a noisy tube until it has burned in for at least 20 hours. Nearly always, they quiet down.


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## Rossliew

No such distortion but i listen at fairly low levels around 9 o clock. I do note that the 6sn7/6hm5 combo does produce some distortion with some of my bass heavy music. Could be the tune's mastering but i doubt it as it sounded fine with other tube configs. Btw, am using the Mk3 with HD800.


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## hypnos1

Well folks, the Chatham 6AS7Gs have been in situ now for some time and they definitely give more than the RCAs...methinks I have pushed my poor IV SE to its limits...don't think I can ask _any_ more from her (luckily still no signs of objection - what a machine lol!). Certainly shall not be needing to look at the Darkvoice ( NOR the Glenn!) for a VERY long time...sigh from wallet..
	

	
	
		
		

		
			





.
  
 So it looks like it's finally _bon voyage_, and my (patient) other half; garden; Koi and camera can get a bit more attention at last...but boy, am I gonna miss this exciting journey, not to mention some great guys - past _and_ present. I never thought getting into valves (vacuum tubes!) would be such fun or so fascinating...main amp next, perhaps?...sorry missus!!
  
 I would like to thank - once again - all who have helped me along the way this past year, and I wish you all HAPPY CONTINUED ROLLING!!
  
 Shall certainly be keeping an eye on what's cookin' though...
	

	
	
		
		

		
		
	


	




.
  
 Cheers everyone.


----------



## mordy

Hi hypnos 1,
  
 Glad to see that you have found the ultimate level in modding the LD amp! I am working on using 6080/6AS7 tubes as power tubes as well. Can't see any wires from the extender sockets, but I assume that they are there, going to a voltage regulator and an external power supply. You probably wrote about it before, but could you describe what you are using to power the Chathams?
  
 My idea is to use two independent 5A voltage regulators. Would one 20V 2.5A PS suffice for a pair of 6080 tubes? I think that at 6.3V this PS translates into 8A. (The tubes draw 2.5A)


----------



## hypnos1

mordy said:


> Hi hypnos 1,
> 
> Glad to see that you have found the ultimate level in modding the LD amp! I am working on using 6080/6AS7 tubes as power tubes as well. Can't see any wires from the extender sockets, but I assume that they are there, going to a voltage regulator and an external power supply. You probably wrote about it before, but could you describe what you are using to power the Chathams?
> 
> My idea is to use two independent 5A voltage regulators. Would one 20V 2.5A PS suffice for a pair of 6080 tubes? I think that at 6.3V this PS translates into 8A. (The tubes draw 2.5A)


 
  
 Hi mordy.
  
 I look forward to hearing your findings when you complete your mod, and do hope you get the same thrilling results as myself, lol!
  
 Ah, I'm glad I've managed to minimise the 'intrusive' look re the mod - another advantage of making my own adapters!...the wires exit the back and almost disappear. Helped, of course, by the fact that (luckily!) the MKIV doesn't need the extenders.
  
 I was using my old laptop power supply/charger at first, but as I wanted it back(!) I opted for a cheap 12V 6A power supply off Amazon - looks like the laptop kind, but meant for those strings of led lights ( £10, on UK site). I'm afraid I'm no expert on electricity, so cannot say for sure if your assumption is correct re higher amps at lower voltage within the same unit being OK..._sounds_ OK, but hopefully others with greater knowledge can confirm?...
  
 I wish you the very best of luck, mordy...and that you have more fruitful results with the MKIII than ilm2 had  
	

	
	
		
		

		
		
	


	




.


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## i luvmusic 2

As i mentioned before my end game tubes are the 6AS7G/6080  and Raytheon 6832 IMO these tubes are nice Driver tubes.
 Few weeks ago when a lot of the topic here are the C3g i nearly pulled the trigger for C3g but then i thought about getting the CRACK so i decided to get those RCA,SYLVANIA and the mysterious GTC 6AS7's  and some RCA,GE and SYLVANIA 6080's some day i might get C3g if i can be sure that it will work with the Crack so now i will wait until i get the Crack.Few more months and i will be back home then crack time and also i need to shipped out all my gears can't be flying with these amps(LD 1+ and LD MK III plus the crappy adapter and power supplies that i build)so i'am hoping that my boss will allow me to go home in a few months and be working in my hometown for good.
 Or i may sale my gears and start a new LD setup.


----------



## bbmiller

hypnos1 said:


> And as I believe you have managed to make your own adapters in the past, the mod needed to provide these tubes with 2.5A each is a piece of cake...and it can be done using the From what to 6SN7 Adapter adapter,


 
 From what (tube NO.) to 6SN7 Adapter adapter?


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## bbmiller

How pure does heater current and voltage have to be? Pictured below are two pictures from this and another thread showing what I think are linear regulators attached to two different types of 12V  DC power supplies one being a laptop and the other being the 12 all rail of a PC power supply. In both pictures the 12V is sent to what the responders called a regulator, but I believe may be a linear regulator to be [size=13px !important]more
	

[/size] precise about it. I thought linear regulators have to waste away a little voltage so if you were to put linear regulators on 12 V to regulate 12 V they would not work. Am I making correct assumptions?
  
 Also I believe I do see slight stroboscopic effects from incandescent light bulbs which aren't strobe lights. I believe this is due to slight fluctuations in the light due to slight cooling between AC cycles with the voltage goes to zero between sine waves. But if we are talking about even slider fluctuations less than 100% pure DC power supply could that affect our audio if used for heater current and not for cathode or anode voltage? 
  
 So in summary is slightly DC impure heater current nonetheless as pure as we will ever need because it is heater current and not cathode or anode voltage and current? And if we do need pure regulated DC from a linear regulator do we have to start out with [size=13px !important]more
	

[/size] than 12V to get a voltage regulated to 12V ?


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## gibosi

bbmiller said:


> From what (tube NO.) to 6SN7 Adapter adapter?


 
  
 To run 6AS7's in the LD:
  
 The stock tube in the LD, 6H6PI/6H6n, has the same pinout as the 6DJ8, 6GC7 and 6FQ7. And the 6AS7 has the same pinout as the 6SN7. So you need an adapter with 6SN7 on top and 6DJ8 or similar on the bottom. These are common and plentiful on eBay.
  
 Next you will need to cut off pins 4 and 5 on the bottom of this adapter which disconnects the tube from the LD's internal heater supply. And then, connect your external heater power supply to pins 7 and 8 on top.


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## bbmiller

>


 
 Whoops I misread. Sorry!


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## gibosi

bbmiller said:


> How pure does heater current and voltage have to be? Pictured below are two pictures from this and another thread showing what I think are linear regulators attached to two different types of 12V  DC power supplies one being a laptop and the other being the 12 all rail of a PC power supply. In both pictures the 12V is sent to what the responders called a regulator, but I believe may be a linear regulator to be [size=13px !important]more
> 
> 
> [/size] precise about it. I thought linear regulators have to waste away a little voltage so if you were to put linear regulators on 12 V to regulate 12 V they would not work. Am I making correct assumptions?
> ...


 
  
 I don't think the voltage has to be all that pure just to run heaters. Collectively, we are successfully using battery chargers, laptop power supplies, virtually anything that can provide adequate voltage and amperage. The cheap regulators we are using allow us to adjust the voltage as our power suppliers might be putting out 30 volts, 24 volts, 15 volts, or whatever. And yes, the regulators do "waste" a little voltage, so if you want to run 12.6 volt tubes, you will need a power supply that can output around 15 volts, or higher.
  
 For drivers, I recommend a 30 volt power supply as this will allow the use of 6.3, 8.4, 12.6, 20 and 25 volt tubes. In order to run 6SN7's as drivers, you will need about 5 watts (6.3V x .6A = 3.78W). If you want to run 6AS7's as drivers, you will need at around 20 watts (6.3V x 2.5A = 15.75W). For power tubes, specifically 6AS7's, which run at 6.3 volts / 2.5 amps, you will need a power supply that can handle both tubes, around 40 watts (6.3V x 5.0A = 31.5W).
  
 Regarding voltage regulators, the limiting factor is usually amperage. Most of what you see on eBay are limited to about 2 amps. These are fine for the vast majority of driver tubes. But if you want to run 6AS7's as drivers, you need a regulator that can comfortably handle 2.5 amps. An inexpensive 5 amp regulator, like the one I have, works well. If you want to run a pair of 6AS7's as power tubes, you will need a regulator that can comfortably handle 5 amps. I personally do not trust my cheap 5 amp regulator to actually handle 5 amps, so if I wanted to run 6AS7's as power tubes, I would purchase one of the cheap 8 amp units, similar to the one that Hypnos1 uses.


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## gibosi

bbmiller said:


> Driver Tubes: 2x JAN 5654 (MK IV) or 2x M8100/CV4010 (MK IV SE)
> Power Tubes: 2x Soviet 6H30EH (MK IV) or 2x 6H30PI Gold-Pin (MK IV SE)
> OK the stock tubes for the LD are 6H6PI/6H6n, well the above is straight from little dot IV specification page and you must obviously be talking about other models of little dot so if you offhand know how it would relate to my little dot IV se model I would appreciate you make it very easy for me and related to my model, though your response as is very much appreciated.


 
  
 The pinout is the same for the 6H30-types and the 6H6-types. You could roll a 6H6PI in your se if you wanted. And therefore, the same adapter can be used for the II, III and IV.


----------



## bbmiller

> Regarding voltage regulators, the limiting factor is usually amperage. Most of what you see on eBay are limited to about 2 amps. These are fine for the vast majority of driver tubes. But if you want to run 6AS7's as drivers
> 
> 
> , you need a regulator that can comfortably handle 2.5 amps. An inexpensive 5 amp regulator, like the one I have, works well. If you want to run a pair of 6AS7's as power tubes, you will need a regulator that can comfortably handle 5 amps. I personally do not trust my cheap 5 amp regulator to actually handle 5 amps, so if I wanted to run 6AS7's as power tubes, I would purchase one of the cheap 8 amp units, similar to the one that Hypnos1 uses.


 
 OK so let me see if I am perceiving things right here. You are saying to get voltage regulation you do have to drop a little voltage. But if you were to run 6AS7 as power tubes you would use this regulator you recommend, even though people here have claimed spectacular results with regulators with less than adequate voltage inputs to regulate or put another way they are essentially running unregulated, but you think running 6AS7 as power tubes with heater supply regulators would be of benefit. I suppose because you think you may be able to get even better results than the people here have gotten with essentially unregulated power that they perceived as being regulated?


----------



## gibosi

bbmiller said:


> OK so let me see if I am perceiving things right here. You are saying to get voltage regulation you do have to drop a little voltage. But if you were to run 6AS7 as power tubes you would use this regulator you recommend, even though people here have claimed spectacular results with regulators with less than adequate voltage inputs to regulate or put another way they are essentially running unregulated, but you think running 6AS7 as power tubes with heater supply regulators would be of benefit. I suppose because you think you may be able to get even better results than the people here have gotten with essentially unregulated power that they perceived as being regulated?


 
  
 I am not sure I completely understand...  But perhaps this will help. The LD can provide, at most, 1.25 amps per power tube. (The stock tubes draw about .9 amps.) However, the 6AS7 requires 2.5 amps per tube, which is far more than the LD can deliver, hence an external power supply is absolutely required to use these tubes.


----------



## hypnos1

bbmiller said:


> From what (tube NO.) to 6SN7 Adapter adapter?


 
  
 Hi bb.
  
 The adapters you need are *6SN7* _to_ *6CG7*...available from xulingmrs on ebay.com. I notice as well as the standard one at $19.90 ea. (free shipping) there is now another with copper cover and a lead for connecting to ground or chassis, for the same price but with $5 shipping - looks very good!
  
 If you go for running the heater wires into the _top_ of the 6CG7 adapter (cutting bottom pins 4&5 completely), instead of from shortened pins 4&5 at the bottom, please remember (hope I'm not insulting you, lol!) that as you look at the adapter from _above,_ the pins run ANTI-clockwise from the 1-8 indent, #1 being to the right of the indent as you look from above...and you need pins (holes) 7&8, of course. Doing this, I should think you would need stranded wire for both this and the pins to fit in the socket (again, hope I'm not insulting you!).
  
 Good luck!


----------



## bbmiller

gibosi said:


> bbmiller said:
> 
> 
> > OK so let me see if I am perceiving things right here. You are saying to get voltage regulation you do have to drop a little voltage. But if you were to run 6AS7 as power tubes you would use this regulator you recommend, even though people here have claimed spectacular results with regulators with less than adequate voltage inputs to regulate or put another way they are essentially running unregulated, but you think running 6AS7 as power tubes with heater supply regulators would be of benefit. I suppose because you think you may be able to get even better results than the people here have gotten with essentially unregulated power that they perceived as being regulated?
> ...


 
 OK am I right in perceiving we are not talking about cathode anode power but he the voltage power. And at least in the case of the person shown in my pictures using the 12 vote PC power supply rail that wasn't adequate voltage to get regulation from his regulator because you do have to drop some voltage. And perhaps I am mix perceiving Hypnos1 said and his posting on this little dot IV se appreciation thread which can be found here, but I thought he said he was using a 12 V laptop power supply which would not give him sufficient voltage drop in his regulator to be running regulated. So if I am perceiving things correctly Hypnos1 was running his power tubes with sufficient amperage, but on insufficient voltage to be running regulated but still getting what sound to him as spectacular results.


----------



## gibosi

bbmiller said:


> OK am I right in perceiving we are not talking about cathode anode power but he the voltage power. And at least in the case of the person shown in my pictures using the 12 vote PC power supply rail that wasn't adequate voltage to get regulation from his regulator because you do have to drop some voltage. And perhaps I am mix perceiving Hypnos1 said and his posting on this little dot IV se appreciation thread which can be found here, but I thought he said he was using a 12 V laptop power supply which would not give him sufficient voltage drop in his regulator to be running regulated. So if I am perceiving things correctly Hypnos1 was running his power tubes with sufficient amperage, but on insufficient voltage to be running regulated but still getting what sound to him as spectacular results.


 
  
 There are essentially two power supplies, one for the heaters alone and the other for the amp. In this case we are talking about the heater supply only. Power to run the amp itself is not affected in any way.
  
 The 6AS7 is a 6.3 volt tube, and therefore, a 12 volt power supply is more than adequate, providing it can provide enough amperage.


----------



## bbmiller

gibosi said:


> There are essentially two power supplies, one for the heaters alone and the other for the amp. In this case we are talking about the heater supply only. Power to run the amp itself is not affected in any way.
> 
> The 6AS7 is a 6.3 volt tube, and therefore, a 12 volt power supply is more than adequate, providing it can provide enough amperage.


 
 Whoops I guess if I had studied the tube numbering system a little better I would've known that. So this that mean if you set up one of these tubes with the regulator in series the 12 V output from one of my many old PC power supplies the regulator would be set to 6.3 V the spot on or would you do something like temporarily put amperage meter in series with the tube and power supply and regulator to adjusted to certain current weather that current was achieved at 6.3 V or something a little higher?


----------



## gibosi

bbmiller said:


> Whoops I guess if I had studied the tube numbering system a little better I would've known that. So this that mean if you set up one of these tubes with the regulator in series the 12 V output from one of my many old PC power supplies the regulator would be set to 6.3 V the spot on or would you do something like temporarily put amperage meter in series with the tube and power supply and regulator to adjusted to certain current weather that current was achieved at 6.3 V or something a little higher?


 
  
 I would assume that any of your old 12 volt PC power supplies can supply the necessary amperage, in this case, 5.0 amps to run two 6AS7's. If you choose a regulator that can provide 5 amps comfortably, you would use the small brass screw to adjust the voltage down to 6.3 volts, and you would be good to go. It is not necessary to adjust the amperage. The tubes will draw only what they need, 5 amps for the two of them, no more and no less.


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## TrollDragon

Now if one were to run the heaters in series you could use the 12 volts from the PC power supply and no regulators would be required...


----------



## bbmiller

trolldragon said:


> Now if one were to run the heaters in series you could use the 12 volts from the PC power supply and no regulators would be required...


 
 I have never taken a very accurate voltage reading of the PC power supplies 12 votes is it exactly 12 votes or is it more like 12.6? Whatever it is would it be right as you explain? A few more words please!


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## i luvmusic 2

It all depends on Desktop PS i do have few of them and the voltage out put varies some have(schiit ones/no name brand)11.something volts i've even saw one that only out put 10 something volts but this one on the picture out put 12.15V(according to my IDEAL Multi metre).One thing to be aware of these type of power supplies some have annoying fan noise and some of them it makes your tube hum but not these one on the picture these one is very quiet fan and all and it's heavier than any desktop PS i have on hand.If the fan is noisy you can just replaced them with quieter model or install a fan speed controller.


----------



## TrollDragon

bbmiller said:


> I have never taken a very accurate voltage reading of the PC power supplies 12 votes is it exactly 12 votes or is it more like 12.6? Whatever it is would it be right as you explain? A few more words please! :eek:


A decent PC power supply with a load attached should put out very close to 12V and be useful for heater supply of the same tubes in a series configuration. The reason I say the same tubes is if you decide to try a tube that draws 2.5 amps with a tube that draws 0.6 amps you will most likely burn out the lesser filament from the bigger tube drawing too much current through it. Best to series the filaments on the same current draw tubes.

You will have to measure the 12 volt line on your power supplies with a load connected such as a hard drive to see if the output would be suitable.

You don't need exactly 12.6 volts, 12V will work fine and the tubes will last a little longer in the process.


----------



## i luvmusic 2

Hi TD,
    Since we are on PS topic how important it is to put a dummy load resistor in the PS?What i did is i installed a 18R 5W resistor (white ceramic resistor don't know what you call them) on 5V rail, and since i tied the 2 12V rails(V1 and V2)does it mean i double up the current?THANKS!


----------



## TrollDragon

Well ILM2...

I don't really know if you parallel both rails if you'll get double the current. Most of the stuff in this thread is unorthodox so it hasn't been tested before as PC power supplies are made for PC's... Utilizing the 3, 5 & 12 rails all at once. So I can't really say if the resistor is needed for the 5V rail or not as well. I'd say take it out and see if it still works, why generate heat when you don't have to?

All the tube amplifiers out there have transformers designed and spec'd to run the HV and Filament supplies and that's it there are no other sources like those from a multivolt switching power supply to deal with.

The best thing would be to find a 12V 8A power supply if anyone wants to run the 6AS7 filaments in series...


----------



## gibosi

trolldragon said:


> The best thing would be to find a 12V 8A power supply if anyone wants to run the 6AS7 filaments in series...


 
  
 Or for those who don't have a suitable 12V desktop PC power supply.....
  
 I am using this laptop power supply, adequate to power the heaters of two 6AS7's connected either in series or parallel.
  
 19V 4.74A AC Adapter Charger For Samsung Laptop for about $9.50 (includes AC power cord).
  
 http://www.ebay.com/itm/151235154803?
  
 And I believe this regulator is similar to the one that Hypnos1 is using:
  
 AC/DC 12-45V to 0.7-21V 8A Step-Down Voltage Regulator for about $8.25
  
 http://www.ebay.com/itm/300839166993?


----------



## TrollDragon

Yes indeed gibosi,
That setup works like a charm, I was just simplifying it a little for those who do not want to mess with regulators.


----------



## hypnos1

gibosi said:


> Or for those who don't have a suitable 12V desktop PC power supply.....
> 
> I am using this laptop power supply, adequate to power the heaters of two 6AS7's connected either in series or parallel.
> 
> ...


 
  
 Hi gibosi and bb.
  
 I have now gone for a higher-rated regulator, which looks a little better made (not a lot!)...
http://www.amazon.com/VvW-4-5-30V-0-8-30V-Converter-Regulator-4-5-30V/dp/B00IOT2TPI/ref=sr_1_2?
  
  
  


trolldragon said:


> Yes indeed gibosi,
> That setup works like a charm, I was just simplifying it a little for those who do not want to mess with regulators.


 
  
 Sure does work like a charm, TD...
  
 ps. With protection circuits built into the regulator - especially the one I mentioned above - will this give added safety?...can't be too careful...or am I being my usual paranoid self, lol?! 
	

	
	
		
		

		
		
	


	




.


----------



## i luvmusic 2

trolldragon said:


> Well ILM2...
> 
> I don't really know if you parallel both rails if you'll get double the current. Most of the stuff in this thread is unorthodox so it hasn't been tested before as PC power supplies are made for PC's... Utilizing the 3, 5 & 12 rails all at once. So I can't really say if the resistor is needed for the 5V rail or not as well. I'd say take it out and see if it still works, why generate heat when you don't have to?
> 
> ...


 
 Without the dummy load on 5V rail if  i plug-in 2 6AS7 on 12V rail the voltage will drop significantly then it goes back up to 12V and with the dummy load i can plugin the tubes and the voltage just dropped a few millivolts does this mean that with the dummy load the PS is more stable?Thanks!


----------



## TrollDragon

No what it means is that a PC power supply is designed to provide multiple voltages all at once and it gets a little wonky when put into service out of its design specifications.

So you'll have to leave the 5V load resistor in place to use the 12V lines.


----------



## TrollDragon

hypnos1 said:


> ps. With protection circuits built into the regulator - especially the one I mentioned above - will this give added safety?...can't be too careful...or am I being my usual paranoid self, lol?! :blink: .


With most inexpensive protection circuits, IF they are designed and working properly will crowbar the output to Zero volts in the event of failure. These ones on your board I believe also disable the regulator chip in the event of a short on the output lines as well.

So you should be alright as far as one can trust inexpensive Chi-Nee products...


----------



## i luvmusic 2

trolldragon said:


> No what it means is that a PC power supply is designed to provide multiple voltages all at once and it gets a little wonky when put into service out of its design specifications.
> 
> So you'll have to leave the 5V load resistor in place to use the 12V lines.


 
 Thank You sir!


----------



## i luvmusic 2

Two packages arrived to day for me i suspect it's those tubes that i ordered but someone at work missed placed it oh i hate being away from home.


----------



## Gravit8

Wow! Just got my 6HM5s... SO much better than stock... How many hours are they rated at? Might pick up another set at this price.  Thanks for the suggestions, this amp just got 5x better ^.^


----------



## TrollDragon

Always good to have spares, just incase....


----------



## hypnos1

trolldragon said:


> With most inexpensive protection circuits, IF they are designed and working properly will crowbar the output to Zero volts in the event of failure. These ones on your board I believe also disable the regulator chip in the event of a short on the output lines as well.
> 
> So you should be alright as far as one can trust inexpensive Chi-Nee products...


 
  
 Thanks TD...at least my new reg'r does seem to have more 'goodies' in it than the first, lol...
  


gravit8 said:


> Wow! Just got my 6HM5s... SO much better than stock... How many hours are they rated at? Might pick up another set at this price.  Thanks for the suggestions, this amp just got 5x better ^.^


 
  
 Hi G8.
  
 Now you're getting some idea of just what our humble LDs are capable of...   WELL DONE!... But remember, they can do _much_  more - something for you to look forward to? 
	

	
	
		
		

		
		
	


	




.
  
 I do believe the 6HM5s have a very good life - perhaps someone else has the true figures?...Whatever, as TD says, it ALWAYS pays to have a couple in reserve, lol...


----------



## philiptw

So my headphone upgrade bug hit me and I am now venturing for a LCD-2..
  
 Any suggestions on what settings/tubes to use with my LD mk3 to drive it? I have heard that OTL amps are in general not very good for planar headphones.. but is a significant factor?
  
@TrollDragon Would really appreciate your input seeing you seem to have a vast understanding of tube amps.. 
	

	
	
		
		

		
		
	


	




 
  
 ps.. discovered the death of 1 of my 6J1P-EV tube from 1975.. quite sad  what am I going to do with the other one lol


----------



## superdux

now i've listened to a few albums and these C3G's seem quite refined and now i really can enjoy my music.Thx for the tip Hypnos and Gibosi


----------



## gibosi

philiptw said:


> So my headphone upgrade bug hit me and I am now venturing for a LCD-2..
> 
> Any suggestions on what settings/tubes to use with my LD mk3 to drive it? I have heard that OTL amps are in general not very good for planar headphones.. but is a significant factor?


 
  
 According to the Audeze home page, the LCD2 has an impedance of 70 ohms. The HE-500 has an impedance of 38 ohms and a number of folks in this thread report that it sounds fine with their mk3 and mk4, so I would think that the LCD2, with almost twice the impedance, would also be fine.


----------



## gibosi

gravit8 said:


> Wow! Just got my 6HM5s... SO much better than stock... How many hours are they rated at? Might pick up another set at this price.  Thanks for the suggestions, this amp just got 5x better ^.^


 
  
 Glad you are enjoying the 6HM5's. But.... the C3g's are "SO much better" than 6HM5's! Rather than picking up another pair, I think you should start saving your money to purchase C3g's!


----------



## sgbwill2

superdux said:


> now i've listened to a few albums and these C3G's seem quite refined and now i really can enjoy my music.Thx for the tip Hypnos and Gibosi


 
 Looks good. May I ask where you ordered the 7 pin miniature tube extender/socket saver from? I've ordered mine from lee's radio and its been 4 weeks now and they still haven't arrived. My c3g's are sitting here and I cant use them


----------



## superdux

sorry for your long wait, but i also ordered at lee's radio.Maybe just ask where they are?I live in germany and mine arrived in about a week.
  
 http://leedsradio.com/parts-sockets.html#savers
  
 oh and beware not to touch the socket savers during playback cos they are for collecting measurements and wire protrudes at the top of them.


----------



## philiptw

gibosi said:


> According to the Audeze home page, the LCD2 has an impedance of 70 ohms. The HE-500 has an impedance of 38 ohms and a number of folks in this thread report that it sounds fine with their mk3 and mk4, so I would think that the LCD2, with almost twice the impedance, would also be fine.


 
  
 From calculation, I think the mk3 can throw out ~150mW at 60ohm , acheiving peak dB of ~113 (91dB/mW) - so providing that I listen at around 97dB (which is already much louder than my normal listening levels) I should have a 16dB headroom which should be plenty..
  
 Tho having said that, I can use my DX90's built in amp (2.8Vrms) to drive it a max of 112dB as well.. 
  
 I don't really get why every/most threads I read on says LD mk3 is terrible for LCD-2.. it cant be that bad can it?
  
  
 EDIT: found 1 post a while back that makes sense imo.. 
 http://www.head-fi.org/t/495631/amp-recommendations-for-audeze-lcd-2/7230#post_10424733
  
 Please correct me if my understanding is incorrect cheers


----------



## TrollDragon

philiptw said:


> So my headphone upgrade bug hit me and I am now venturing for a LCD-2..
> 
> Any suggestions on what settings/tubes to use with my LD mk3 to drive it? I have heard that OTL amps are in general not very good for planar headphones.. but is a significant factor?
> 
> ...


 
 Hey philiptw,
  
 I don't have a vast understanding of tube amps, I got into electronics after tubes. 
	

	
	
		
		

		
		
	


	



 I was a technician for Rat Shack when they were big here in Canada, fixing their CB's 8Tracks, Cassette Deck's, Reel to Reel's and those big ugly Direct Coupled amplifiers they used to sell as well as all the other assorted junk in their catalog.
  
 So no... I am just a tech from a bygone era, a Hack and a Tinkerer. 
	

	
	
		
		

		
		
	


	



  
 But I ran the LCD-3's for a few weeks on the MK IV with no problem...

 6CS6's as drivers, before all the thread advancements. 
  
 Over in the MK IV appreciation thread there is a post from a user who runs LCD-2's, they work good with his MK IV but sound so much better he states from his Schiit Lyr. Which makes sense since the LCD's are a low Z headphone and the Lyr (2 Now) is a hybrid that can dump out a massive 6 Watts in 32Ω, there is ample power with a ton of headroom to play with. The Conductor SL could run the LCD-3's with some authority as well but it's a SS amp.
  
 Something you might want to seriously consider looking into.
  
 Sorry for your tube loss as well...


----------



## tjw321

> Spoiler: Warning: Spoiler!
> 
> 
> 
> ...


 
 That is the most awesome headphone stand ever!


----------



## hypnos1

superdux said:


> now i've listened to a few albums and these C3G's seem quite refined and now i really can enjoy my music.Thx for the tip Hypnos and Gibosi


 
  
 Hi superd.
  
 Glad you like the C3gs...another convert! Just wait 'til you have 40-50 hours on them, lol!
  
 Then...some nice 6SN7s behind them? Better still, be brave and enter 6AS7G/6080 land?...Aaaaahh 
	

	
	
		
		

		
		
	


	



  


trolldragon said:


> Well ILM2... Most of the stuff in this thread is unorthodox...


 
  
 Unorthodox?...AGREED, TD. But I would also venture to add : resourceful; pioneering; fascinating; educational; rewarding, BRAVE...and not a little MAD! But isn't this precisely what so often results in the greatest quantum leaps in _any_ endeavour? (And, no doubt, been a source of a little amusement for the 'purists', lol!).
  
 Whatever, hopefully what has been achieved is proving to be of great benefit to those LD owners who are now enjoying a level of sound from their lowly machines way beyond what may have ever been thought possible (well, it is for _me_ anyways!). And hopefully also for those yet to come...
	

	
	
		
		

		
		
	


	




.


----------



## TrollDragon

tjw321 said:


> That is the most awesome headphone stand ever!


 
 Thanks!
  
 Here is another one I made. 
	

	
	
		
		

		
		
	


	




  
 Here is a Flickr Set
 https://www.flickr.com/photos/troll_dragon/sets/72157635038856825


----------



## tjw321

trolldragon said:


> Thanks!
> 
> Here is another one I made.
> 
> ...


 
 Very nice - both of them. My metal-working skills are non-existent but if I get a bit of spare time, I think I might have a go at making something (maybe wood would be a safer medium for me 
	

	
	
		
		

		
		
	


	




). The corner of my monitor will thank me for it....


----------



## TrollDragon

tjw321 said:


> Very nice - both of them. My metal-working skills are non-existent but if I get a bit of spare time, I think I might have a go at making something (maybe wood would be a safer medium for me
> 
> 
> 
> ...


 
 Thanks! but there is not much metal working skills there...
 Just 1/2" copper pipe and some fittings. The big one was epoxied with PC-7 & JB Weld, the small one was soldered and that makes a real mess which does not look as good when you buff it.
  
 Have you looked through the DIY Headphone Stand Thread? Many a great stand and lots of ideas in there. 
	

	
	
		
		

		
		
	


	



 http://www.head-fi.org/t/249671/the-diy-headphone-stand-thread
  
  
 Do something up for sure!


----------



## mordy

Hi philiptw,
  
 Unless your Voskhod tube turned white inside instead of the silver coating I do not believe that it is dead. I once had a 6N6P tube that I wrote off for dead, but did not throw it away. A year later I gently scraped the pins with a pocket knife blade, pushed it in and out of the socket a few times, and it worked perfectly again. Seems a little oxidation caused it to malfunction.
  
 Take any kind a knife blade that is small, hobby knife, pen knife etc, and just scrape each pin gently from different angles. Take a look if you can see oxidation on the pins, and if so, especially scrape those parts.
  
 Let me know when you revive the tube...
  
 Good luck!


----------



## philiptw

mordy said:


> Hi philiptw,
> 
> Unless your Voskhod tube turned white inside instead of the silver coating I do not believe that it is dead. I once had a 6N6P tube that I wrote off for dead, but did not throw it away. A year later I gently scraped the pins with a pocket knife blade, pushed it in and out of the socket a few times, and it worked perfectly again. Seems a little oxidation caused it to malfunction.
> 
> ...


 
  
 Thanks Mordy 
  
 Unfortunately the getters are white powdery so I am pretty sure of its demise.. there's also a crack at the bottom of the tube..
 I wanted to open it up to see the structure but seeing as platinum can be a toxic chemical I decided to not open it up.
  
 See the photo below for the Voskhod's #beautifuldeath (any GoT fans here?)


----------



## mordy

Here is a little update on using the 6080 2.5A tube as a power tube. At this point I am waiting for a second 5A voltage regulator from China, but couldn't resist trying out one channel with a 6080. Picked a 6080 RCA that only earned a so-so rating as driver tube (my notes say 'murky") just in case Something Would Happen.
  
 In order to use it in the LD MKIII it is first plugged into an octal to 9 pin adapter; then into a 9 pin extender to fit inside the ring surrounding the socket. This extender was taken apart and pins #4 and 5 were de-soldered and removed and replaced with two wires going to the external voltage regulator. This necessitated drilling a hole in the side of the extender socket to allow for the two wires to exit neatly.
  
 The tube complement features an all star set up of the 1957 subminiature 6832 as driver (using the built in LD power supply), a 1957 Tung Sol 6SN7GTB as power tube for the left channel (LD powered) and the 1962 RCA 6080 as power tube for the right channel, using the external 5A PS.
  
 A trial run indicated that the amp was getting warm. After an hour it was quite warm, but  not too hot to touch. Out of caution I installed a fan to cool off the amp. Here are a couple of pics:
  
 Here is a close up of the extender showing the two wires coming out and teeth #4&5 missing. Used a little piece of white sticker to mark off the right pins and a little piece of blue to line up with the indentation on the top so that it goes together correctly.

  
  
 Here is the fan assembly. The fan comes from a an old PC power supply and was picked for being fairly quiet. The power supply is a 12V wall wart that once powered a router. The plastic fasteners are used to tie the fan to my equipment rack in such a way that the fan sucks away the hot air instead of blowing directly on the amp. If you touch the 6080 you could burn yourself (ouch, just did), but the fan lowers the temperature of the amp chassis significantly.

  
 Here is the triple dual triode (tongue twister?) line-up. The 6832 is swinging to the music like a buoy on the ocean. (Finally got the nail polish insulation but have yet to decide on fire engine red or turquoise blue.)

  
 The sound is fabulous with a glorious bass and treble (and this is with the worst sounding 6080 I have!). Will have to try to better sounding 6080s and the coke bottle 6AS7 RCA as well. Meanwhile I am just enjoying the sound. Did I mention that this set-up is very quiet as well?
  
 Here I have to quote hypnos 1 on the achievements of the members on this forum:
  
_Unorthodox?...AGREE . But I would also venture to add : resourceful; pioneering; fascinating; educational; rewarding, BRAVE...and not a little MAD! But isn't this precisely what so often results in the greatest quantum leaps in any endeavor? (And, no doubt, been a source of a little amusement for the 'purists', lol!)._
  
_Whatever, hopefully what has been achieved is proving to be of great benefit to those LD owners who are now enjoying a level of sound from their lowly machines way beyond what may have ever been thought possible (well, it is for me anyways!). And hopefully also for those yet to come..._
  

```
[b][i]Maybe alternating red and blue? LOL......[/i][/b]
```


----------



## mordy

Hi philiptw,
  
 You made the correct diagnosis; the tube died from lack of vacuum - sorry. The good news is that there are better choices....


----------



## i luvmusic 2

Since most of us tried or continue using 6AS7/6080 tubes as Power tubes what if we use these tubes for both driver and power, what would be the out come?Maybe a big bang.


----------



## mordy

As long as you have the required external PS there is no problem in running a 6AS7/6080 as a driver. With an amplification factor of 2 the volume has to be turned up higher. You just have to experiment and see which tube/tube combination sounds the best.
  
 Having tried such tubes as drivers my impression is that the subminiature 6832 sounds better as a driver, whereas the 6832 cannot compete with the 6080 as a power tube for lack of power in the bass region. The way I envision it in my mind is that the power tubes contribute significantly to the bass and rhythmic foundation of the sound presentation. Having the 6AS7/6080 as a driver might be a little "heavy handed", but I may be wrong. Haven't tried it yet.


----------



## i luvmusic 2

Sorry i mean can we use 3 6AS7/6080 tubes all at once for LD MK III/IV or would it be too much for LD circuits?


----------



## i luvmusic 2

Oh schiit i'am going to kick my self on the head i accidentally dropped one of my G.T.C. 6AS7G i just received these tubes few minutes ago.
	

	
	
		
		

		
		
	


	




.


----------



## philiptw

i luvmusic 2 said:


> Spoiler: Warning: Spoiler!
> 
> 
> 
> ...


 
  
 RIP... I feel your pain..


----------



## i luvmusic 2

Yup that's what i get for not being careful got too excited because the G.T.C. is a mystery tube.


----------



## gibosi

i luvmusic 2 said:


> Sorry i mean can we use 3 6AS7/6080 tubes all at once for LD MK III/IV or would it be too much for LD circuits?


 
  
 The driver and power circuits are separate and the heaters are powered externally, so it _should_ work. But I don't know that anyone has tried it yet.


----------



## gibosi

i luvmusic 2 said:


> Yup that's what i get for not being careful got too excited because the G.T.C. is a mystery tube.


 
  
 I am pretty sure your GTC was manufactured by Tung Sol / Chatham.....


----------



## i luvmusic 2

gibosi said:


> I am pretty sure your GTC was manufactured by Tung Sol / Chatham.....


 
 Yeah who ever makes it it sound nice.


----------



## i luvmusic 2

gibosi said:


> The driver and power circuits are separate and the heaters are powered externally, so it _should_ work. But I don't know that anyone has tried it yet.


 
 You know what since the GTC is on the driver's socket i will turn off the PS and the amp and let it cool down so i can change the 2 RCA Power tubes with 2 SYLVANIA 6080 wish my LD MK III luck.


----------



## kvtaco17

gibosi said:


> I am pretty sure your GTC was manufactured by Tung Sol / Chatham.....


 
  
 I though the Tung-Sol/Chatham tubes all had top getters and earlier examples had grey glass bottoms and new examples had clear bottoms?


----------



## i luvmusic 2

Just wanna say wow a bit more power in bass would be perfect setup.


----------



## i luvmusic 2

i luvmusic 2 said:


> Just wanna say wow a bit more power in bass would be perfect setup.


 
 These tube setup makes me thinking of butchering my MK III put it in a bigger case similar to what i did to LD 1+ and install a case fan.


----------



## gibosi

kvtaco17 said:


> I though the Tung-Sol/Chatham tubes all had top getters and earlier examples had grey glass bottoms and new examples had clear bottoms?


 
  
 I suspect that over the years, as with most tubes, the construction changed. However, I have a pair of Chatham 6AS7's that look very similar to i luvmusic 2's. Mine have two bottom D getters, and of course, clear tops. And unlike the RCA's, no shields below the bottom mica. I am beginning to believe that of the American manufacturers, only Tung Sol and RCA manufactured these tubes. All the GE, Sylvania, Westinghouse and Raytheon that I have seen so far appear to my eyes to be rebranded versions of these two. There are also quite a few rebranded Russian 6AS7G's out there and these look quite similar to the Tung-Sol. However, the top shield is taller and of course, they have the flying-saucer getters.
  
 For example, my guess is this GE was manufactured by Tung Sol:
  
 http://www.ebay.com/itm/151300296001?
  
 And these two Amperex. The one of the left may well have been manufactured in England but it has the tall top shields (and probably saucer getters), and is likely of Russian origin. And the one on the right with bottom shields is likely an RCA:
  
 http://www.ebay.com/itm/2-NOS-Amperex-6AS7G-Tubes-/351085497478?
   

 To be clear, I am speaking only of the coke-bottle 6AS7G. The 6AS7GA appears to have been more widely manufactured.


----------



## mordy

Hi G,
  
 Which re-branded Coke bottle 6AS7G tubes are most likely to be Tung Sol tubes?


----------



## gibosi

mordy said:


> Which re-branded Coke bottle 6AS7G tubes are most likely to be Tung Sol tubes?


 
  
 I don't know.... It appears that RCA manufactured many more 6AS7's than Tung Sol, so most of the rebrands I see were made by RCA. In the end, all you can do is look at the construction. If it has shields below the lower mica, it is very likely an RCA. If there are no shields below the lower mica it is likely Tung Sol or Russian.


----------



## i luvmusic 2

I took TD's advised about connecting the heater wires in series and it workout well the Desktop PS 12V output is now divided into two sections one for MK III's power heaters in series(6AS7/6080 and 6S.. tubes) and the other section is for the 12A regulator for driver tube and something else it free up some load for 12A regulator.  Again Thank You Mr. TD! Oh and the sound is amazing the bass is really extended  deep and the details are superb nuh JUST KIDDING!


----------



## i luvmusic 2

Anyone here from GTA area wants to buy a one 5A and one 3A step down regulator with display?


----------



## TrollDragon

You are most Welcome ILM2! :basshead:


----------



## i luvmusic 2

gibosi said:


> The driver and power circuits are separate and the heaters are powered externally, so it _should_ work. But I don't know that anyone has tried it yet.


 
 Thanks G! i've tried this last night it's a nice setup.


----------



## hypnos1

i luvmusic 2 said:


> These tube setup makes me thinking of butchering my MK III put it in a bigger case similar to what i did to LD 1+ and install a case fan.


 
  
 Sure was a sad loss re your Chatham...they are seriously good tubes. But fear not, vacuumtubes.net have them for $20 ea.
  
 And if you do butcher your MKIII, do your fellow MKIII owners a big favour and try to see if there's any (relatively) easy way you can get rid of those pesky rings, so y'all can do away with those even peskier extenders, lol! -  I'm sure the tubes would say "thank you", and make things look neater...GOOD LUCK. ( Mind you, mordy's trick of drilling through the extenders to take the heater wires is really neat!).


----------



## hypnos1

mordy said:


> Here is a little update on using the 6080 2.5A tube as a power tube. At this point I am waiting for a second 5A voltage regulator from China, but couldn't resist trying out one channel with a 6080. Picked a 6080 RCA that only earned a so-so rating as driver tube (my notes say 'murky") just in case Something Would Happen.
> 
> In order to use it in the LD MKIII it is first plugged into an octal to 9 pin adapter; then into a 9 pin extender to fit inside the ring surrounding the socket. This extender was taken apart and pins #4 and 5 were de-soldered and removed and replaced with two wires going to the external voltage regulator. This necessitated drilling a hole in the side of the extender socket to allow for the two wires to exit neatly.
> 
> ...


 
  
 Hey mordy.
  
 Sooo glad you have finally managed to see/hear for yourself what this move can do...just wait 'til you get TWO really good 6080s/6AS7Gs in the hot seat!..I am smiling for you already, lol!


----------



## i luvmusic 2

hypnos1 said:


> Sure was a sad loss re your Chatham...they are seriously good tubes. But fear not, vacuumtubes.net have them for $20 ea.
> 
> And if you do butcher your MKIII, do your fellow MKIII owners a big favour and try to see if there's any (relatively) easy way you can get rid of those pesky rings, so y'all can do away with those even peskier extenders, lol! -  I'm sure the tubes would say "thank you", and make things look neater...GOOD LUCK. ( Mind you, mordy's trick of drilling through the extenders to take the heater wires is really neat!).


 
  I did opened my MK III halfway.Back when i was butchering the 1+ IMO no other easy way to removed those rings without removing the MK III's PCB if you removed the PCB you can access those two screws per ring holding the rings from the bottom of the case..


----------



## hypnos1

i luvmusic 2 said:


> I did opened my MK III halfway.Back when i was butchering the 1+ IMO no other easy way to removed those rings without removing the MK III's PCB if you removed the PCB you can access those two screws per ring holding the rings from the bottom of the case..


 
  
 Oh dear...looks like you MKIII guys are well and truly bu*****d, lol!...I did tell you to go get yourselves a MKIV SE 
	

	
	
		
		

		
		
	


	




...they do sometimes seem to appear on the 2nd-hand market (but not often! 
	

	
	
		
		

		
		
	


	




).
  
 Ah well, it seems you can all still get GRRREEAT results, regardless...
	

	
	
		
		

		
		
	


	




.


----------



## i luvmusic 2

hypnos1 said:


> Oh dear...looks like you MKIII guys are well and truly bu*****d, lol!...I did tell you to go get yourselves a MKIV SE
> 
> 
> 
> ...


 
 How did you removed yours?The BH Crack would be my next amp.


----------



## Oskari

gibosi said:


> And these two Amperex. The one of the left may well have been manufactured in England but it has the tall top shields (and probably saucer getters), and is likely of Russian origin. And the one on the right with bottom shields is likely an RCA:
> 
> http://www.ebay.com/itm/2-NOS-Amperex-6AS7G-Tubes-/351085497478?


 
  
 The one on the left is clearly a Svetlana. Note the distinctive bottle shape.


----------



## TrollDragon

i luvmusic 2 said:


> How did you removed yours?The BH Crack would be my next amp.


The gold anodized plate with the tube guards comes off the MK IV from the top. 

Crack with Speedball, will be a sweet amplifier.


----------



## i luvmusic 2

trolldragon said:


> The gold anodized plate with the tube guards comes off the MK IV from the top.
> 
> 
> 
> ...


 
 That easy to removed i guess and yes BH Crack is going to have the speedball.


----------



## tjw321

I got my Little Dot MK III about a week ago and yesterday a pair of Mullard M8100s arrived which I'd pre-ordered in anticipation. They came a bit faster than expected! Anyway, I had to try them out, just to see if they were working...
  
 It's too early to say as the original tubes are still burning-in, the Mullards are still burning-in, and so are my headphones (arrived just after the Little Dot), but I would tentatively agree with Dept_of_Alchemy's first post regarding the Mullards. I'm very much enjoying the bass, but I'm going to try and find something with a bit more detail (though I expect the burn-in will take care of that, anyway). I've got a couple of Voskhod 6ZH1P-EVs on the way which I'm going to try next.
  
 I'm keeping it simple ATM - just trying drop-in replacements so I haven't had to fiddle with any jumpers yet. Does anyone think it is worth me doing any power tube rolling (with recommendatons, if so) or should I just stick with the drivers for now? Actually, I should probably get at least one set of drivers burnt-in first...
  
 It's going to be interesting re-trying the tubes once they are all burnt-in...
 So, thank you all for the advice in this thread. I was very pleasantly surprised how easy the first tube rolling steps are. 
	

	
	
		
		

		
		
	


	



  
 And an extra thank you to TrollDragon for pointing me at the DIY headphone stands thread. I should have said something earlier but I'd already derailed the thread enough by that point!
  
 And finally, apologies in advance if I ever write valve - I'm English and I can just about remember valve driven computers...so I can't help it.


----------



## philiptw

tjw321 said:


> I got my Little Dot MK III about a week ago and yesterday a pair of Mullard M8100s arrived which I'd pre-ordered in anticipation. They came a bit faster than expected! Anyway, I had to try them out, just to see if they were working...
> 
> It's too early to say as the original tubes are still burning-in, the Mullards are still burning-in, and so are my headphones (arrived just after the Little Dot), but I would tentatively agree with Dept_of_Alchemy's first post regarding the Mullards. I'm very much enjoying the bass, but I'm going to try and find something with a bit more detail (though I expect the burn-in will take care of that, anyway). I've got a couple of Voskhod 6ZH1P-EVs on the way which I'm going to try next.
> 
> ...


 
  
 Hey there,
  
 I took the exact same steps of gear acquisition as you 
  
 As my signature states, my source is the DX90.
  
 The Mullards will indeed become better and better as they burn in further.
 Personally I found the Voskhods to not be as fully "bodied" as the Mullards, and the detail can be just a tad too much for my personal taste at times (can become fatiguing IMO).
 The Mullards have been sitting in my Driver slots the most since their arrival and I think that suggests something.
  
 I rolled 6H30Pi-EHs for my power tube and I think there is not a dramatic difference in sound when compared to the stock tubes.. but I am using the 6h30pi for now and keeping the stock power tubes as backups.
  
 Enjoy the journey of tube rolling.. before the upgraditis bug hits again.. which has already done so for me... haha!


----------



## tjw321

philiptw said:


> Hey there,
> 
> I took the exact same steps of gear acquisition as you
> 
> ...


 
 That's interesting. I already had a couple of 6H30Pi-EHs in my "basket" and was dithering a bit about whether to buy them "just in case". I'll probably go ahead and buy them now, as I don't really want to have to wait too many days if I need replacements at any time.
 I'm using an Arcam irDAC into the Little Dot with either a Mac, or an X3 as source. I haven't used the X3 directly into the Little Dot (yet).
 My headphones are either HD600s, or AKG K702s (I bought them in local stock clearances, unauditioned, at a too good to be missed price, and ending up liking both, despite/because of their differences), so I expect I'll be swapping tubes to match my 'phones - or vice versa...
 I've only tried the HD600s with the Mullards, so far. I think the AKGs might well be a better match. So many things to try, so little time....


----------



## TrollDragon

tjw321 said:


> And an extra thank you to TrollDragon for pointing me at the DIY headphone stands thread. I should have said something earlier but I'd already derailed the thread enough by that point!


You are most welcome!

Have no worries I derail this thread all the time, it always finds its way back to the straight and narrow. If you build a stand please post a picture or two here as I don't subscribe to the Stand thread anymore. Too many stick a pair of headphones on anything around the house and call it a stand. Those are the furthest thing from DIY and is disrespectful to the people who actually build a stand... But that is my pet peeve... 

Welcome to the Club (Little Dot & Tube Rolling) you should pick up a pair of Yugoslavian 6HM5's from eBay as well to have in your stable, they are one of the best tubes for plug and play the members here have found.

Call them Valves, Tubes or FireBottles it all good!

Edit: The Line Out of the X3 works perfectly as a source for the LD!


----------



## bbmiller

I have been noticing a tremendous improvement in the sound of my little dot IV se without tube rolling, but if I start listening to it after high have it on with the volume control in the 10 o'clock position after four hours. I am wondering if anyone here has ever observed this or would be willing to test this assertion cause I could assure you it is true. Both male and female voices become more realistic and so does the sound of the orchestra.
  
 I am wondering how one would test if it is OK to use your little dot IV se amplifier beyond the stated eight hour limit before cooldown. What do you think?


----------



## TrollDragon

bbmiller said:


> I am wondering how one would test if it is OK to use your little dot IV se amplifier beyond the stated eight hour limit before cooldown. What do you think?


The biggest contributor to shortening the life of electronic components is heat. When you run the amplifier and place a hand on the case, the heat you feel is not generated by the tubes, the heat comes from current flowing through the resistors on the board, these are Chinese resistors, so finding an operational parameter sheet on them would be next to impossible.

I personally would not run the amplifier past its recommend time but the choice is yours.


----------



## tjw321

trolldragon said:


> You are most welcome!
> 
> Have no worries I derail this thread all the time, it always finds its way back to the straight and narrow. If you build a stand please post a picture or two here as I don't subscribe to the Stand thread anymore. Too many stick a pair of headphones on anything around the house and call it a stand. Those are the furthest thing from DIY and is disrespectful to the people who actually build a stand... But that is my pet peeve...
> 
> ...


 
 Unfortunately my skills are more mental than physical. I have the manual dexterity of an elephant wearing mittens - hence my tube rolling being limited to the jumper-free variety...so far. I have been somewhat inspired, and will give it a go, though - and if the result is passable, I'll post pictures. I have a couple of ideas....
  
 I managed to locate some Yugoslavian 6HM5's so I'll soon have even more unburnt-in tubes. Thanks for the tip. 
	

	
	
		
		

		
		
	


	



  
 The listening session with the AKGs and the Mullards did not go well. What I love about the AKGs is the detail they pick up but, right now, some of that detail is in the rough region which I think burn-in will smooth out. The same thing happened for the first couple of days with the stock tubes. I don't normally do this, but I think it may be time to dig out "pink-noise.wav"...
  
 I'll give the line-out of the X3 a go sometime but it'll have to be something special to beat taking the X3 coax into the irDAC. (NB, I have used the line-out of the X3 elsewhere and I really wouldn't be surprised if it gives the irDAC a bit of stiff competition, but I have to at least pretend the irDAC was money well-spent - or isn't that the head-fi way? 
	

	
	
		
		

		
		
	


	




).


----------



## i luvmusic 2

My experienced with the Q7XX with MK III is not that bad but it's better with LD 1+ specially with the 6SN7 and 6AS7 tubes.


----------



## hypnos1

i luvmusic 2 said:


> How did you removed yours?The BH Crack would be my next amp.


 
  
 Hi ilm2.
  
 As TD said, the tube rings and plate just screw off...nice and easy...
  
 And have just had a horrible reply from vacuumtubes.net...they're out of stock of the Chatham 6AS7Gs! -  All the more galling as I only got 2 the first time...and that after advising (like TD) to always make sure to have more in reserve!..PHYSICIAN HEAL THYSELF, no?! So now I'm gonna have to do a mordy and keep on searching, searching, and more searching...so much to do, and so little time...
  
 But search I must, as these Chathams are delivering more with every new piece of music I try...I am wondering what on earth the BH Crack (or similar) could bring to the table, especially as they - the Chathams - are making the C3GSs sing like no canary you have ever known, lol!


----------



## MIKELAP

hypnos1 said:


> Hi ilm2.
> 
> As TD said, the tube rings and plate just screw off...nice and easy...
> 
> ...


 
 I manage to get a pair last month from vacuumtubes.net also ,and got a Chatham 6AS7G this morning from my tube guy at the flea market but even better than that i got a pair of Chatham's 2399 when i got the Woo and if you know the price these go for ,im very happy about that because i wouldnt pay that kind of money for those tubes to start with .So i should be  good for awhile but they always pop up somewhere And of course everybody knows   so there you go


----------



## mordy

Hi bbmiller,
  
 I have found that using the Little Dot MKIII at as a high a volume as I can before clipping produces the best sound. In my case this translates to three o'clock on the volume dial, but I play through a ss amp. With my headphones on I can't turn up the volume more than 9-10 o'clock or I'll damage my hearing.
  
 As is well known, heat is the biggest enemy of electronics, and this is probably the reason the manual advises against more than eight hours on at a time. Different tubes heat up the amp differently, some leave the amp cool, others warm and some burning hot. For hot running tubes I am using a discarded computer fan to direct away the hot air from the amp, with good results.
  
 There have been times when I have left the amp on for several _days_ burning in tubes without any untoward effects. Just check here and there with your hand if the amp is running cool. As far as I recall, other people did the same and nobody reported problems.
  
 I once asked David Zhe Zhe what the anticipated life span is of the amp. He replied: The same as regular consumer electronics - around 20 years.


----------



## sgbwill2

Hi guys. Seen as the 7 pin extenders/socket savers were lost in transit I decided to remove the brass rings. After much deliberation I got them off and now the 6sn7's and c3g's fit and no extenders are needed. Now I'm just wondering how people have removed the metal casings on the c3g's? Thought I would ask in advance just in case I break the tubes removing them.
  
 Thanks


----------



## i luvmusic 2

This looks similar to the G.T.C. 6AS7G.


----------



## hypnos1

sgbwill2 said:


> Hi guys. Seen as the 7 pin extenders/socket savers were lost in transit I decided to remove the brass rings. After much deliberation I got them off and now the 6sn7's and c3g's fit and no extenders are needed. Now I'm just wondering how people have removed the metal casings on the c3g's? Thought I would ask in advance just in case I break the tubes removing them.
> 
> Thanks


 
  
 Hi sgb.
  
 I did in fact post a photo tutorial - #5683 - which should hopefully help you. You can either leave the base loose, or glue it back on - you'll need a thick glue, and be careful it doesn't run down into the pins. Either way, you will need to make ABSOLUTELY sure the 'church windows' match up to maintain proper pin placement...I found the base could _almost_ fit convincingly onto the pins in any order!
  
 Hope all goes well...it'll look SO much better, lol!
  
 Any questions/problems just let us know...will be back on tomorrow...
  
 Cheers.


----------



## sgbwill2

hypnos1 said:


> Hi sgb.
> 
> I did in fact post a photo tutorial - #5683 - which should hopefully help you. You can either leave the base loose, or glue it back on - you'll need a thick glue, and be careful it doesn't run down into the pins. Either way, you will need to make ABSOLUTELY sure the 'church windows' match up to maintain proper pin placement...I found the base could _almost_ fit convincingly onto the pins in any order!
> 
> ...


 
 Thank hypnos. Might attempt it sometime in the future. Seems like a fair bit of effort though I do like to see tube glow  Why do the tubes have the casing in the first place? does it help to keep them cool? I was apprehensive of trying these c3g's due to the rave reviews and didn't want to be disappointed though I'm glad you and others recommended them. Along with the 6sn7's this amp is in another league now. Just got my sylvania 1952 'bad boys' 6sn7's to arrive and I think I'm set and wont be buying tubes (for the LD MKIII anyway) ever again unless another incredible tube like the c3g gets discovered.


----------



## TrollDragon

mikelap said:


>


Dude!
You have a Reel to Reel?
HOW COME I DON'T KNOW ABOUT THIS????


----------



## TrollDragon

tjw321 said:


> Unfortunately my skills are more mental than physical. I have the manual dexterity of an elephant wearing mittens - hence my tube rolling being limited to the jumper-free variety...so far. I have been somewhat inspired, and will give it a go, though - and if the result is passable, I'll post pictures. I have a couple of ideas....
> 
> I managed to locate some Yugoslavian 6HM5's so I'll soon have even more unburnt-in tubes. Thanks for the tip.
> 
> ...


The Coax Out from the X3 should be very nice into the Arcam for sure, I would have rather had an Optical on the X3, not for any specific sound difference from Coax, I just like Toslink cables... 

Enjoy the 6HM5's when they arrive.


----------



## philiptw

trolldragon said:


> Dude!
> You have a Reel to Reel?
> HOW COME I DON'T KNOW ABOUT THIS????


 
  
 lol TD please explain your excitement over Reel to Reel 
  
 I am curious now..


----------



## markm1

Newbie-alert. I've just bought a Grado RS1i and am thinking about a LD1+. Sorting through 400 + pages here is a little daunting. Would any of you give me some suggestions as a starting point?


----------



## kvtaco17

markm1 said:


> Newbie-alert. I've just bought a Grado RS1i and am thinking about a LD1+. Sorting through 400 + pages here is a little daunting. Would any of you give me some suggestions as a starting point?


 
 I'd start with this chart...
  
 http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/1140#post_9392055


----------



## tjw321

trolldragon said:


> The Coax Out from the X3 should be very nice into the Arcam for sure, I would have rather had an Optical on the X3, not for any specific sound difference from Coax, I just like Toslink cables...
> 
> 
> 
> ...


 
 I hear you. I still can't believe that something as "science fiction" as optical cables seemed when they first came out can now be matched by a bit of antenna cable. It just doesn't seem right.


----------



## TrollDragon

philiptw said:


> lol TD please explain your excitement over Reel to Reel
> 
> I am curious now..


I Have heard some great stuff back in the day on R2R systems, seeing that deck in the background brings back fond memorys from the repair shop of torque meters, test tapes, head alignments... Stuff I haven't seen or used in years, when someone brought in a R2R deck for service, one took pride in tuning it up top notch as you knew the music was appreciated and not just background noise.

That's all... I havn't heard one in years.


----------



## markm1

kvtaco17 said:


> I'd start with this chart...
> 
> http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/1140#post_9392055


 

 thanks!


----------



## tjw321

Just a quick progress report, and I'll stop spamming the thread for a while. I put 4 hours of pink noise through the Mullards and things are improving nicely. I don't think the AKG K702s will need any more detail, after all, and I believe that the AKG/Mullard combination will be very much to my taste. Still plenty of improvements to come though (I think). I'll get a bit more time on these tubes then I'll try the Voskhods. I've a feeling that they will work well with my HD600s.

Then I can do it all over again with the 6HM5s 

At least it's cheaper than buying a whole new amp to tweak your sound


----------



## philiptw

tjw321 said:


> At least it's cheaper than buying a whole new amp to tweak your sound


 
  
 Inb4 you go for a planar headphone eg LCD-3/HE-6


----------



## gibosi

sgbwill2 said:


> Hi guys. Seen as the 7 pin extenders/socket savers were lost in transit I decided to remove the brass rings. After much deliberation I got them off and now the 6sn7's and c3g's fit and no extenders are needed. Now I'm just wondering how people have removed the metal casings on the c3g's? Thought I would ask in advance just in case I break the tubes removing them.


 
  
 These tubes were designed to last 10,000 hours in their little metal cans. The metal casings were designed to shield these tubes from electrical interference as they were typically used in noisy environments. So it is perfectly fine to leave them in their cans forever. The only reason to run them "nude" is aesthetic.


----------



## mordy

Here is another update on the great sounding LD MKIII Raytheon 6832 subminiature setup. In anticipation of receiving another 5A voltage regulator for the left 6080 power tube, I cobbled together a separate power supply using my old 2A voltage regulator to test everything out.
  
 Since I cannot run the second 6080 yet, I put in a Westinghouse 12SN7GT in the left socket. Previously, when I used this tube as a driver, it distinguished itself as very good sounding. The one 6080 I have installed runs _very_ hot (I have a small burn mark mark on my thumb to prove it). I decided to change the external cooling fan from 3" to 4" for greater air flow.
  
 This fan also came from my parts bin of old computer parts. It makes a little whining noise, but the music drowns it out. For the second PS I found an old laptop PS rated 19V/2.6A. The inexpensive extenders have an unexpected benefit - they are not deep enough that the pins go all the way down, leaving a small gap. There is enough space to touch the the voltage meter probes to pins 4&5 and get an actual _in vivo_ reading of the voltage with the tube in place and the PS plugged in. It is easier to do this before inserting the entire tube assembly into the LD sockets.
  
 Close-up of the gap:

  
  
 The three musketeers shooting electrons:
 .
  
 The two voltage regulators in action. Although indicated 7V and 12.5V, the actual measurements at the tube pins are 6.3V and 12.6V.

  
 Bought some inexpensive heat shrink tubing that is supposed to shrink to half the thickness when heat is applied. Since I do not have a heat gun I used a cigarette lighter to shrink the tubing. The trick is to hold the flame some distance from the tubing and watch it shrink. Stop before the heat shrink turns burnt hot dog color (right side of wire).

 This is an experiment in joining two wires without solder. I put two wires side by side and slipped the heatshrink tubing over the two pieces, then heated it.

 The red section shows the heat shrink joint - seems to be holding fine.
  
 Coming back to the three tube set-up - sounds very good. The bigger fan keeps the amp cooler.
  
 Have fun!


----------



## MIKELAP

trolldragon said:


> Dude!
> You have a Reel to Reel?
> HOW COME I DON'T KNOW ABOUT THIS????


 
 I can confirm i do lol . Simple i didnt mention it lol.


----------



## hypnos1

mikelap said:


> I manage to get a pair last month from vacuumtubes.net also ,and got a Chatham 6AS7G this morning from my tube guy at the flea market but even better than that i got a pair of Chatham's 2399 when i got the Woo and if you know the price these go for ,im very happy about that because i wouldnt pay that kind of money for those tubes to start with .So i should be  good for awhile but they always pop up somewhere And of course everybody knows   so there you go


 
  
 OMG! mikelap...looks like you struck gold TWICE, you lucky b******! Sure wish I had a flea market like that near me, lol...(don't see many valves - ie tubes - in such places here in the UK, more's the pity).


----------



## Rossliew

Guys, would the following vector adaptor with 12AX7 tube work with the Mk 3? http://www.head-fi.org/t/718599/lots-of-desktop-amps
  
 Does it require an external power supply?


----------



## MIKELAP

hypnos1 said:


> OMG! mikelap...looks like you struck gold TWICE, you lucky b******! Sure wish I had a flea market like that near me, lol...(don't see many valves - ie tubes - in such places here in the UK, more's the pity).


 
 The guy has a website with the tubes he has in stock just check it out you never know this is the list he gave me regarding 6as7g tubes heres link for the website and list he sent me                                                  http://www.tubebazar.com/


----------



## gibosi

rossliew said:


> Guys, would the following vector adaptor with 12AX7 tube work with the Mk 3? http://www.head-fi.org/t/718599/lots-of-desktop-amps
> 
> Does it require an external power supply?


 
  
 Yes, these will work in LD 1, II, III and IV. Actually, you need two Vectors and an external 9-pin breadboard socket with compression block connectors.
  
 Vectors are here:
  
 http://www.radiodaze.com/product/15450.aspx
  
 There are lots of breadboard sockets on eBay. Here is one:
  
 http://www.ebay.com/itm/9-pin-Ceramic-Breadboard-tube-socket-for-Experiments-Prototypes-/161327960735?pt=Vintage_Electronics_R2&hash=item258fe5529f
  
 You can roll 6DJ8 and 12AX7/12AT7?12AU7 without an external power supply. The external PS is necessary only when you are rolling tubes that need more than about .450 amps, such as 6SN7, ECC40 and E80CC.


----------



## Rossliew

gibosi said:


> Yes, these will work in LD 1, II, III and IV. Actually, you need two Vectors and an external 9-pin breadboard socket with compression block connectors.
> 
> Vectors are here:
> 
> ...


 
 Thanks...so I need to make an extra set of the vectors plus breadboard to complete it?


----------



## gibosi

rossliew said:


> Thanks...so I need to make an extra set of the vectors plus breadboard to complete it?


 
  
 You need two vectors and one socket and then you can roll anything under .45 amps.
  
 Here is a 6DJ8, and again, you do not need the external PS.
  

  
 And here, a pair of C3g's, and again, you do not need the external PS:
  

  
 And here is a sub-miniature Sylvania 7963, and again, no external PS is necessary:
  

  
 edit: added sub-miniature


----------



## Rossliew

Ok, got it..Joe's bundle includes both vectors and a breadboard. But for the 6DJ8, would I need to rewire the vectors to the breadboard?


----------



## gibosi

rossliew said:


> Ok, got it..Joe's bundle includes both vectors and a breadboard. But for the 6DJ8, would I need to rewire the vectors to the breadboard?


 
  
 Yes, you would need to change the way pins 4, 5 and 9 are wired on the breadboard to configure the heaters properly depending on whether you are running 12AX7-type tubes or 6DJ8-type tubes. Loosen a couple screws, move a couple wires, retighten, and done. It's easy.


----------



## Rossliew

gibosi said:


> Yes, you would need to change the way pins 4, 5 and 9 are wired on the breadboard to configure the heaters properly depending on whether you are running 12AX7-type tubes or 6DJ8-type tubes. Loosen a couple screws, move a couple wires, retighten, and done. It's easy.


 
 Gracias!!


----------



## gibosi

And it just occurred to me, you could leave the socket in the 6DJ8 configuration and then purchase an adapter, 12AX7 on top and 6DJ8 on the bottom.


----------



## hypnos1

mikelap said:


> The guy has a website with the tubes he has in stock just check it out you never know this is the list he gave me regarding 6as7g tubes heres link for the website and list he sent me                                                  http://www.tubebazar.com/


 
  
 Thanks mikelap. Will keep him in mind...
  
 Unfortunately, I have a horrible feeling in my (increasingly old!) bones that, despite mordy's optimistic view that bargains will always "appear", we are now going to be at the mercy of the profit-takers...unless one wants RCAs, that is!  And as my C3GSs much prefer the Chathams, I can only hope these JANs have a good LONG life, lol! 
	

	
	
		
		

		
			





.


----------



## hypnos1

sgbwill2 said:


> Thank hypnos. Might attempt it sometime in the future. Seems like a fair bit of effort though I do like to see tube glow  Why do the tubes have the casing in the first place? does it help to keep them cool? I was apprehensive of trying these c3g's due to the rave reviews and didn't want to be disappointed though I'm glad you and others recommended them. Along with the 6sn7's this amp is in another league now. Just got my sylvania 1952 'bad boys' 6sn7's to arrive and I think I'm set and wont be buying tubes (for the LD MKIII anyway) ever again unless another incredible tube like the c3g gets discovered.


 
  
 Hi again sgb.
  
 As long as you take things carefully and follow the instructions to the letter, it isn't _too_ tricky a job, lol...
  
 So glad you too can now enjoy the 'Super-LD', with those mods...we have come a LONG way since Dept-of- Alchemy started this thread. I only wish he could see - and HEAR - what has been achieved...haven't a clue what happened to him, unfortunately...


----------



## CITIZENLIN

I just received C3Gs and adapters. Got excited and put them on LD MK IV.  BUT NO SOUND COME ON. If I crank the volume to the max I could hear tiny tiny sound. C3gs do get warm, so there is power just no sound. I think I got the bad adapters. Tubes that seeding in adapters are not straight (leaning one side) and adapters doesn't sit straight on LD sockets.  Kind of disappointed after all the wait.  Its strange that no sound from both channels. I put 6HM5 back on and they are working perfectly. Any idea? ( Is there ON/OFF switch on adapter? j/k).


----------



## gibosi

That's a bummer! 
  
 And I agree with your thinking... The chance of getting two defective C3g tubes seems minuscule to me, so it must be that the adapters are wired-up wrong. Or maybe the adapter's ON/OFF switches are in the wrong position? lol Seriously, ask the adapter vendor to make this right for you.
  
 Cheers


----------



## CITIZENLIN

gibosi said:


> That's a bummer!
> 
> And I agree with your thinking... The chance of getting two defective C3g tubes seems minuscule to me, so it must be that the adapters are wired-up wrong. Or maybe the adapter's ON/OFF switches are in the wrong position? lol Seriously, ask the adapter vendor to make this right for you.
> 
> Cheers


 
 C3Gs look spanking NEW to me but workmanship on adapters are HMMMmmmm how can I put it nicely!!! LOL. May be they do good job (most of you didn't have any problem with adapters) or may be this is just isolated case. I will contact ebay vendor now.


----------



## gibosi

My adapters work fine. But they do look a bit different than yours....


----------



## i luvmusic 2

IMO the easiest way to used two 6080/6AS7 power tubes is to connect them in series to a desktop power supply the output is 12V so no need for the regulator and also this type of PS have plenty of current.I even tried running my power tubes and the driver tube in 5V and i can't tell the deference between 6.3V and 5V the volume setting is in the same position so they sound the same to me even the tubes  are under voltage/under powered.You only need to use the regulator for the driver tube but in my case i used the 5V rail from the desktop PS i don't used regulator any more.Thanks to TD!


----------



## i luvmusic 2

Oh and did i say the tubes are very quiet,some of the tubes that i have it have a slight hum but the hum is not cause by the tubes it's from the DC adapter.Each time i reused the dc adapter the slight hum would come back and for the dc adapter i need to ground the output of the regulator from the LD case but for the desktop PS no need for extra ground.


----------



## CITIZENLIN

I think they are the same but the tube on mine are unevenly sticking out.

  

 Still looking for hidden ON/OFF switch on adapter. LOL


----------



## i luvmusic 2

Why is the bottom are uneven?I hoped it didn't cost you arm and leg for that adapters.


----------



## CITIZENLIN

i luvmusic 2 said:


> Why is the bottom are uneven?I hoped it didn't cost you arm and leg for that adapters.


 
 Well, it did. totally poor workmanship for the price. They look little better in photo. They are actually worst than photos.


----------



## i luvmusic 2

Actually that's not bad at all,I sent back my 9 pin adapters to chinada because of very poor/ugly workmanship but in the end the seller sent me a good one thanks for me for being picky.


----------



## i luvmusic 2

Sorry for your wallet though.


----------



## TrollDragon

Make sure to contact him before you leave negative feedback... The Chinese sellers sure hate the negative feedback.

You should be able to send him pictures and have two express shipped for free.

My guess is they are shorted out inside or not hooked up correctly, they could most likely be fixed depending on how much epoxy they used in the construction.


----------



## CITIZENLIN

i luvmusic 2 said:


> Sorry for your wallet though.


 
 I had many sleepless nights making decision(buy or not to buy) on C3GS and adapters. HAHAH that will teach me lesson for spending money that you don't have.


----------



## CITIZENLIN

Quote: 





trolldragon said:


> Make sure to contact him before you leave negative feedback... The Chinese sellers sure hate the negative feedback.
> 
> You should be able to send him pictures and have two express shipped for free.
> 
> My guess is they are shorted out inside or not hooked up correctly, they could most likely be fixed depending on how much epoxy they used in the construction.


 
 I sent the email to "happydiy998" regarding this situation and awaiting reply. I am sure they will fix it (wish me luck) . Here are some   (not so proud DIY headphone stand)


----------



## i luvmusic 2

citizenlin said:


> I sent the email to "happydiy998" regarding this situation and awaiting reply. I am sure they will fix it (wish me luck) .


 
 Will good luck! That is the same seller i bought from(9 pin socket saver)but in the end he did pay for the return shipping and sent me a nice pieces after 6 weeks of bugging him/her.


----------



## CITIZENLIN

i luvmusic 2 said:


> Will good luck! That is the same seller i bought from(9 pin socket saver)but in the end he did pay for the return shipping and sent me a nice pieces after 6 weeks of bugging him/her.


 
 HAHA Thanks alot. Maybe they sent me the one you just returned.


----------



## TrollDragon

citizenlin said:


> I sent the email to "happydiy998" regarding this situation and awaiting reply. I am sure they will fix it (wish me luck) . Here are some   (not so proud DIY headphone stand)


Good Luck! Hope it all turns out good, such a long wait from China.

That is a great stand with a nice collection mounted on it!


----------



## CITIZENLIN

i luvmusic 2 said:


> Will good luck! That is the same seller i bought from(9 pin socket saver)but in the end he did pay for the return shipping and sent me a nice pieces after 6 weeks of bugging him/her.


 
 Looks like I am onto a long ride of back and fort emails with "happydiy998".
 I just received two emails with different tunes
 The first one said
  
 ========
Hello,

 We will ship one pair tomorrow again,

 please kindly ship back the two pcs you received to following address:

 Ms. Tse Yuk Chi, Shop 20, G/Fl., Fullview Garden Shopping Centre, 18 Siu Sai Wan Road, Hong Kong. 00852 92166680

 tomorrow or the day after tomorrow, we will send you tracking number,

 any questions, please kindly contact us again,

 Thanks&Best Regards,
 Vanessa
  
- happydiy998
====
 
Then I asked her to make sure they work before she them out replacement. This is her 2nd email within 2 hours from previous email
 
=======
 
Hello,

This adapter is made by hand, so every item can not look exactly the same, and meterial can not be find easily, I will ask our technical person becareful when he makes the adaters,

We sold several pairs, now only you says they are not work, we want to test the adapters, would you please ship it back for a check? we did tested it before delivery,

my suggestion is to refund you money fully, and you send back the adapters to us to check, when we confirm the adapters are defective, we will send another pair for free, if not, we will send you money for the shipping cost you spend, is that ok?

Looking forward to hearing from you soon,

Thanks&Best Regards,
Vanessa
=======
 
Simple plug and play turning into nightmare. I don't like the direction its going . SIGH.....


----------



## manizkrishnan

Hello, I recently bought Russian Tubes 6Zh1P-EV = 6J1P-EV ( 6Ж1П-ЕВ ) an quality equivalent of the EF95 / 6F32 and NOS RUSSIAN TUBES 6N6P-I ( 6Н6П-И ) an quality equivalent of the ECC99 / E182CC for my liitle dot MK III amp. Can i install these tubes with out changing anything? You seems to know lot about tube rolling. any help would be really appreciated.


----------



## CITIZENLIN

manizkrishnan said:


> Hello, I recently bought Russian Tubes 6Zh1P-EV = 6J1P-EV ( 6Ж1П-ЕВ ) an quality equivalent of the EF95 / 6F32 and NOS RUSSIAN TUBES 6N6P-I ( 6Н6П-И ) an quality equivalent of the ECC99 / E182CC for my liitle dot MK III amp. Can i install these tubes with out changing anything? You seems to know lot about tube rolling. any help would be really appreciated.


 
 I just went through the whole tube rolling thing. 6zh1p are better than stock driver tubes and 6n6P-I are really good my favorite of all. I recently got a pair of 6HM5 (tall )from EB suggested by few guru on this thread and indeed they are my favorite combo. 6N6P-I & 6HM5 (got them for 5 USD ea.). Then there are other options.... 6SN7 as power tube.


----------



## manizkrishnan

Thanks for the reply. I have not received my tubes yet. I will try these tubes for a while. So i can just replace the stock tubes with these tubes right? No need to change anything inside the amp?


----------



## gibosi

manizkrishnan said:


> Hello, I recently bought Russian Tubes 6Zh1P-EV = 6J1P-EV ( 6Ж1П-ЕВ ) an quality equivalent of the EF95 / 6F32 and NOS RUSSIAN TUBES 6N6P-I ( 6Н6П-И ) an quality equivalent of the ECC99 / E182CC for my liitle dot MK III amp. Can i install these tubes with out changing anything? You seems to know lot about tube rolling. any help would be really appreciated.


 
  
 Yes, you can use the 6J1P-EV and the 6N6P-I in your Little Dot without changing anything.


----------



## mordy

I'm sure many of you know the feeling. You turn on your beloved system, and somethin' is wrong. What, the left channel isn't working! What could the problem be? Speakers? PC? Bad connection? Did you finally kill the LD?
  
 Well, u didn't listen to TD, and you did this crazy stuff and ran one channel on 12V and the other on 6V, and you used a 2.5A tube (with ext PS) where the max is 1.25A. How much does it cost to send it back to China? How do you contact LD? How long will it take to get it fixed? Could it be one of those pesky resistors (shudder)?Is it cheaper to buy a new one? MKIII or IV?
  
 Perspiration, anxiety, worry. How can I listen to mediocre sound in the absence of the LD?
  
 Well, let's see. Pull out all the external stuff, pull on all the wires, change all the tubes to OEM stuff. PC? - no, it works both channels. LD? Only the right channel. OK, I'll rewire the 6832 adapter; while I'm at it I'll add some some heat shrink insulation; seems less messy than turquoise nail polish - or red nail nail polish. Slap everything together. Perspiration. Doing a mental check: Can't remember any electronic acrid burnt smell, no poof or loud crackle. All three heaters light up. OK - turn on the sound. Sounds good, BUT ONLY THE RIGHT CHANNEL. Panic.
  
 Well, it got to be something simple. Maybe. Didn't smell anything acrid, right. Of course, it must be that one of the E95 jumpers underneath worked itself loose or corroded. You just had to demonstrate that drum solo to one of your grand children, didn't you? Check - nyet; everything in place. Still NO LEFT CHANNEL. What's next? Check all the cables to the LD - everything OK. Calm down, take a few deep breaths, think about something else (can't). RELAX, RELAX.
  
 To make a long story short: On the back of my 35 year old Sony amp is a slider switch that switches on and off an external equalizer loop. The LD is connected to this loop. Turns out that the switch corroded and killed the left channel. A few pushes back and forth cleared up everything. Hurray! Everything works! Need to get the super advanced hi tech super mods in place again - 12.6V 12SN7GT, 6.3V 6080, and the 6832 in it's new red clothes.
  
 Relief...RELIEF....*RELIEF*
  
 Another day in the life of a Little Dot owner.....


----------



## manizkrishnan

Thank You  I am so excited now.


----------



## TrollDragon

Good to hear mordy it was only the tape monitor switch on the receiver.

You would definitely know the smell of cooked resistors, they have a unique smell that lingers. When electrolytic capacitors go, its usually with a bang sometimes as the metal can flys off. Other times its just a loud hiss and a nasty smell of cooked electrolyte.

Time to pick up a little contact cleaner for the switches on the receiver.


----------



## JoeDoe

For anyone interested in the C3G tubes, I'm selling my two with 6ak5 adapters. Pm for a way to save some scratch on importing and wait times.


----------



## tjw321

So I've now got 3 sets of drivers:
  
 Mullard M8100 with 10 hours of burn-in
 Voskhod 6ZH1P-EV with 4 hours of burn in
 Stock Tubes with 20 hours of burn in
  
 At the moment, Voskhod >> Stock > Mullard. So, I know I'm nowhere near fully burnt-in on any of the tubes, but I'm surprised that the stock ones are still (a little) better than the Mullards at this point in time - and that the Voskhods are so good with so little burn-in time. Can I expect the Mullards to catch up after some more hours burn-in? Or will they start to shine with the 6H30Pi power tubes? (which have *just* arrived BTW - I was expecting a few more day's playtime with the drivers first - I bet if I'd been desperate for them they would have taken weeks).


----------



## gibosi

tjw321 said:


> So I've now got 3 sets of drivers:
> 
> Mullard M8100 with 10 hours of burn-in
> Voskhod 6ZH1P-EV with 4 hours of burn in
> ...


 
  
 What is "great" for one person is often just "so-so" for another, even given the same amp, tubes and headphones. And so it is hard to predict which tubes will be "your" favorites. For now, it is best to withhold judgement until all of them have been burned in, and then you can do a shootout to figure out which is best given your ears and gear.


----------



## tjw321

gibosi said:


> What is "great" for one person is often just "so-so" for another, even given the same amp, tubes and headphones. And so it is hard to predict which tubes will be "your" favorites. For now, it is best to withhold judgement until all of them have been burned in, and then you can do a shootout to figure out which is best given your ears and gear.


 
 Thanks - will do. The shootout is (at least) half the fun, after all


----------



## mordy

Another update on the use of subminiature dual triode vacuum tubes with eight thin flexible leads in the LD amps. IMHO this approach of solderless connections should make it easy for anyone to try these type of tubes.
  
 All you need is 1mm heat shrink tubing and 18 gauge solid copper wire + one 9 pin tube socket saver/extender and a breadboard.. A cigarette lighter can be used as a heat source for shrinking the tubing. (It would be possible to make the leads a little longer and do away with both the breadboard and socket extender and just stick in the appropriate leads directly into both driver tube sockets.)
  
 Cut the tubing to cover the flexible leads, cut up little pieces of 1" copper wire. Insert the copper pieces into the heat shrink tube, leaving 5mm exposed wire sticking out. Heat and serve.
  
 Here the 6832 does it's octopus imitation:

  
 Look, new shoes! (I did scrape off the little oxidation from the flame)

  
  
 Close-up of wiring into socket extender. A little tricky to get the right order, but not too difficult.
  

  
 Action photo. It is not necessary that the flexible wires are absolutely straight as long as you can thread the sleeve on. The heat shrinking makes for a tight good fit. If you want to change tubes, just pull out the socket extender the same as any other tube.

  
 These little submini tubes are not visually appealing, but sound wise they can stand their own against anything we've tried, including the priciest icons. If you haven't heard one yet, give it a try. You may be in for a surprise.....


----------



## mordy

Hi tjw321,
  
 Based on experience most tubes need 30-50 hours of burn in to stabilize. The Voskhods are an exception - they need 110-120 hours of burn in. And the 6832 submini came into it's own after some 70 hours...
  
 Patience, patience


----------



## tjw321

mordy said:


> Hi tjw321,
> 
> Based on experience most tubes need 30-50 hours of burn in to stabilize. The Voskhods are an exception - they need 110-120 hours of burn in.


 
 Thanks - I had a feeling that I'd read that the Voskhods were supposed to take a bit longer - that's why I was a bit surprised that they were appreciably better than the Mullards after a much shorter burn in time. Maybe the Mullards need a bit more contact cleaning. I have too much burning in to do....so many tubes, so little time


----------



## hypnos1

citizenlin said:


> Looks like I am onto a long ride of back and fort emails with "happydiy998".
> I just received two emails with different tunes
> The first one said
> 
> ...


 
  
 Hi C.
  
 Am SO disheartened you are going through the mill for something that should - and eventually WILL, mon ami - be bringing wonderful anticipation, then overwhelming joy, lol!
  
 It's almost as if I talked it up when I mentioned some time ago that I hoped the adapter-makers did nothing to spoil the magic of these tubes...deja vu?!
  
 I must admit I am not at all impressed with the examples you have shown...you MUST demand better - I am a real amateur, but even the ones I made (the first being a little 'Heath Robinson', admittedly!) didn't look too bad and WORKED!!...well actually, they were even _more_ tricky because I attached the new (silver) pins direct to the tube pins...baptism of fire, you might say!
  
 So COURAGE, my friend...  you will get there in the end, and it will all be worthwhile...
	

	
	
		
		

		
		
	


	




.
  
  


mordy said:


> I'm sure many of you know the feeling. You turn on your beloved system, and somethin' is wrong. What, the left channel isn't working! What could the problem be? Speakers? PC? Bad connection? Did you finally kill the LD?
> 
> Well, u didn't listen to TD, and you did this crazy stuff and ran one channel on 12V and the other on 6V, and you used a 2.5A tube (with ext PS) where the max is 1.25A. How much does it cost to send it back to China? How do you contact LD? How long will it take to get it fixed? Could it be one of those pesky resistors (shudder)?Is it cheaper to buy a new one? MKIII or IV?
> 
> ...


 
  
 Hey mordy...PLEASE, PLEASE don't deliver such shocks...my poor old ticker can't handle it!
  
 Had nightmare visions of the (MY!!) amp suddenly doubling as a toaster, given the punishment we are now meting out to the poor old thing(s)...
  
 But SO glad it turned out to be just a minor hiccough...and that you did actually manage to find its source...a touch of Sherlock Holmes, or just plain GOOD LUCK?!
  
 Cheers...
  
 ps. Don't do it again...please! 
	

	
	
		
		

		
		
	


	




...and


----------



## i luvmusic 2

citizenlin said:


> Looks like I am onto a long ride of back and fort emails with "happydiy998".
> I just received two emails with different tunes
> The first one said
> 
> ...


 
 I heard that tune before good luck!


----------



## gibosi

mordy said:


> Another update on the use of subminiature dual triode vacuum tubes with eight thin flexible leads in the LD amps. IMHO this approach of solderless connections should make it easy for anyone to try these type of tubes.
> 
> All you need is 1mm heat shrink tubing and 18 gauge solid copper wire + one 9 pin tube socket saver/extender and a breadboard.. A cigarette lighter can be used as a heat source for shrinking the tubing.
> 
> ...


 
  
 Mordy, a great tutorial! This is as easy as it gets! And now there is no excuse for anyone not to try these sub-miniatures, either the Raytheon 6832 (I also see Sylvania on eBay), or the Sylvania 7963.
  
 IMHO the 7963 is as good as any tube I have. I would describe it as a "refined" version of the 1940's Sylvania 6SN7W. It has essentially the same sound signature - strong detailed bass, smooth silky mids and airy highs, but a bit more linear, faster, quieter.... and a lot cheaper!


----------



## i luvmusic 2

mordy said:


> I'm sure many of you know the feeling. You turn on your beloved system, and somethin' is wrong. What, the left channel isn't working! What could the problem be? Speakers? PC? Bad connection? Did you finally kill the LD?
> 
> Well, u didn't listen to TD, and you did this crazy stuff and ran one channel on 12V and the other on 6V, and you used a 2.5A tube (with ext PS) where the max is 1.25A. How much does it cost to send it back to China? How do you contact LD? How long will it take to get it fixed? Could it be one of those pesky resistors (shudder)?Is it cheaper to buy a new one? MKIII or IV?
> 
> ...


 
 IMO the LD MK III can handle 2 6080/6AS7 Power Tubes and 1 6080/6AS7 Driver Tube i've tried this before  only i'am not comfortable running it for long due to heat issue.


----------



## TrollDragon

I'm sorry ILM2 but that just doesn't equate. In your opinion you feel that the Little Dot can handle 3 power tubes but yet you won't run it in that configuration because the amplifier gets too hot...

Well then I guess it really doesn't handle it, does it?


----------



## i luvmusic 2

Yes the amp start to gets warm around one hour of used i don't know if that is adequate enough for me to say it can handle it.If i'am only home i don't mind running it longer than that.I usually shut down the amp as soon as it gets warm the longest amount of time i used that set up 2 to 3 hours then i noticed it's hotter than usual.


----------



## TrollDragon

Personally I wouldn't risk it, heat is a killer and if the case is too hot to leave your hand on comfortably. Then there is an issue.

But I'm just the broken record...
So YMMV


----------



## i luvmusic 2

I thought about butchering the MK III and install a fan but then again  that's more work i just wait and build  a CRACK instead.


----------



## i luvmusic 2

Does anyone here did a comparison between the 6080 and 6AS7G driver tubes?Thanks!


----------



## bbmiller

tjw321 said:


> Thanks - will do. The shootout is (at least) half the fun, after all


 
 I do not know how many people have tried this, but I find the stock tubes take on an amazing improved audio quality once you have your little dot IV se on for more than four hours. I turned them on for hours before I want to start listening. Call me nuts but if you could include this in your shoot out and report here how the more than 4 hours on stock tubes compared with the rest of the ones in your shoot out I would be very appreciative.


----------



## mordy

Hi i luvmusic 2 and TD,
  
 Regarding the heat generated by the 6080 tubes - there is plenty of it. At this time I am only running one 6080 (waiting for a second voltage regulator). In order to alleviate the (over?) heating problem, I installed a 4" fan from a discarded computer.
  

  
 The fan runs off a 12V wall wart and is attached to my equipment rack with plastic ties in such a way that it draws the hot air away from the amp. With the ambient temperature in my room at 77 F the amp is barely warm to the touch after running for many hours (6-7 hours). Plan to turn on the A/C since it is too warm in the room now. Even with a second 6080 I anticipate that the heat will not be a problem. If it does become a problem I can always go to a bigger fan or a dual fan setup.
  
 Meanwhile the Little Dot is singing the wonderful 6832 tune - perfect.....


----------



## i luvmusic 2

mordy said:


> Hi i luvmusic 2 and TD,
> 
> Regarding the heat generated by the 6080 tubes - there is plenty of it. At this time I am only running one 6080 (waiting for a second voltage regulator). In order to alleviate the (over?) heating problem, I installed a 4" fan from a discarded computer.
> 
> ...


 
 I like the setup(2 6080/6AS7 power tubes and 1 6080/6AS7 driver tube)i only run my amp for one hour or so due to heat but i may try your cooling fan method.THANKS!BTW the 6832 is amazing tube.


----------



## TrollDragon

So I have this shaft with a sealed bearing in a pillow block, there is too much torque on the bearing, it gets hot and starts to squeal. I put a fan or two in front of the pillow block to blow away the heat, now the bearing is quiet...

Does this not seem like a problem?

The properly designed bearing would have a grease nipple on it to apply some of Titans oil as it is designed to take the load.

Which reminds me of an old gir...
Never Mind.


----------



## mordy

Hi bbmiller,
  
 IMHO most tubes need a little warm up to sound the best. Usually I found that this period is a matter of minutes. Some larger octal tubes may need 30 minutes or more to sound their best. Have not noticed that tubes sound better after four hours.
  
 There are other factors that come into play. All the above refers to tubes that have been burned in. In addition, many times your equipment sounds better late at night when a host of appliances, lights and electronic devices may be turned off, thus providing an electronic environment with less electric interference.


----------



## mordy

Hi i luvmusic 2,
  
 I have very limited experience with the 6AS7 and 6080 tubes. When I tried the RCA 6AS7 as a driver I felt that it was very detailed and layered, allowing me to see into the sound stage and hear new things. The 6080 as a driver I found to have more punch in the bass and a little less detail and decided that overall it is well suited as a power tube. I have 7 6080 tubes, all various RCAs and one GE. The RCAs are from different years and have different construction details, and there are differences in the sound.


----------



## bbmiller

bbmiller said:


> tjw321 said:
> 
> 
> > Thanks - will do. The shootout is (at least) half the fun, after all
> ...


 



mordy said:


> Hi bbmiller,
> 
> IMHO most tubes need a little warm up to sound the best. Usually I found that this period is a matter of minutes. Some larger octal tubes may need 30 minutes or more to sound their best. Have not noticed that tubes sound better after four hours.
> 
> There are other factors that come into play. All the above refers to tubes that have been burned in. In addition, many times your equipment sounds better late at night when a host of appliances, lights and electronic devices may be turned off, thus providing an electronic environment with less electric interference.


 
 well I would very much swear what I am hearing is real and not imagined or placebo in my opinion. Over four hours warming is the ticket for better sound with the original tubes in the little dot IV se.


----------



## i luvmusic 2

mordy said:


> Hi i luvmusic 2,
> 
> I have very limited experience with the 6AS7 and 6080 tubes. When I tried the RCA 6AS7 as a driver I felt that it was very detailed and layered, allowing me to see into the sound stage and hear new things. The 6080 as a driver I found to have more punch in the bass and a little less detail and decided that overall it is well suited as a power tube. I have 7 6080 tubes, all various RCAs and one GE. The RCAs are from different years and have different construction details, and there are differences in the sound.


 
 This is why asked because most of my 6AS7 have more detail than the 6080's except the G.T.C. 6AS7G this have more bass than the RCA's,GE's amd SYLVANIA's.Thanks!


----------



## i luvmusic 2

trolldragon said:


> So I have this shaft with a sealed bearing in a pillow block, there is too much torque on the bearing, it gets hot and starts to squeal. I put a fan or two in front of the pillow block to blow away the heat, now the bearing is quiet...
> 
> Does this not seem like a problem?
> 
> ...


 
 No need to worry if i ever use a fan i will use one of this.
	

	
	
		
		

		
		
	


	







 JUST KIDDING TD!


----------



## TrollDragon

That will work providing you can drive enough kerosene into it at a decent rate...


----------



## mordy

Maybe this machine will take care of the cooling of 3 6080s........
  




  
 All kidding aside, my amp is cool to the touch with the A/C on and a room temperature of 72F with the 4" fan on. Have to see how it works with two 6080s.
  
 Yesterday ran the amp 9 hours without problems.
  
 PS: If you are curious what this is, it's a wind tunnel to test jet engines in cold weather ingesting ice and rain.
       http://www.wired.com/2012/02/ge-heads-north-for-new-jet-engine-ice-test-facility/


----------



## superdux

citizenlin said:


> I think they are the same but the tube on mine are unevenly sticking out.
> 
> 
> 
> Still looking for hidden ON/OFF switch on adapter. LOL


 

 Hi, i found the seller to be very friendly but we also had one tube with a slightly cracked base holding the pins but which still worked.I hope you get to enjoy your C3G's very soon.I have experienced them to be very resolving with good presentation of freq. spectrum.


----------



## tjw321

trolldragon said:


> The Coax Out from the X3 should be very nice into the Arcam for sure, I would have rather had an Optical on the X3, not for any specific sound difference from Coax, I just like Toslink cables...
> 
> 
> 
> ...


 
 The 6HM5s just arrived. I haven't had much time with them yet, but judging by the first session, these are going to be my "keepers". And they were the cheapest - if they live up to their initial promise I might get a couple of spares whilst I can.
  
 Thanks for the tip.


----------



## hypnos1

sgbwill2 said:


> Hi guys. Seen as the 7 pin extenders/socket savers were lost in transit I decided to remove the brass rings. After much deliberation I got them off and now the 6sn7's and c3g's fit and no extenders are needed. Now I'm just wondering how people have removed the metal casings on the c3g's? Thought I would ask in advance just in case I break the tubes removing them.
> 
> Thanks


 
  
 Hi sgb.
  
 Was intrigued as to how you removed those rings...I'm sure your fellow MKIII owners would be grateful for any advice, if interested in the latest 'super' mods!
  


tjw321 said:


> The 6HM5s just arrived. I haven't had much time with them yet, but judging by the first session, these are going to be my "keepers". And they were the cheapest - if they live up to their initial promise I might get a couple of spares whilst I can.
> 
> Thanks for the tip.


 
  
 Good to hear you like the 6HM5s...certainly about the best straight replacement for the (much inferior) stock.
  
 It seems a lifetime ago now since gibosi first gave these a try, but despite fear of repetition I must urge you to continue the quest...as you must have gathered by now, we have found MUCH better still. If funds permit, the C3G driver is WAY ahead, and improves yet again with 6SN7s as power tubes (the 6AS7G/6080 may be just a step too far for you?!). And there are adapters available for both said driver and power...and if sgbwill2 has found a (not _too_ difficult)  way to remove those rings, you may not have to worry about the additional 'extenders'.
  
 Just food for thought, lol?


----------



## tjw321

hypnos1 said:


> Hi sgb.
> 
> Was intrigued as to how you removed those rings...I'm sure your fellow MKIII owners would be grateful for any advice, if interested in the latest 'super' mods!
> 
> ...


 
 Thanks for the words of encouragement - much appreciated. I've only had the Little Dot for about 2 weeks and I have 4 sets of drivers and 2 sets of power tubes. I don't think there is really much chance I'm going to stop there. 
	

	
	
		
		

		
		
	


	



 I should get at least one set properly burnt-in, though. I'm particularly keen to give the Mullards some more time as, based on others' impressions of them, they should suit me to a tee. So my short term goal is to give the Mullards more chance to shine, and to see how the 6HM5s go.
 Longer term - who knows? 
	

	
	
		
		

		
		
	


	




  It'll be a few months before I'm tempted by any "major surgery" though...


----------



## sgbwill2

hypnos1 said:


> Hi sgb.
> 
> Was intrigued as to how you removed those rings...I'm sure your fellow MKIII owners would be grateful for any advice, if interested in the latest 'super' mods!


 
 Hi hypnos,
  
 It wasnt all too difficult really. All I did was I undid the screws at the back of the amplifier so the panel can partially come off (as wires still keep it attached) then I undid the alan key screws at the front and then took off the volume knob (using an alan key again as theres a small hole on the knob which has an allan key screw in it) after this you can completely remove the front cover (after detaching the volume control from the front cover by un-bolting it). After this I undid the screws on the top of the amplifier which fixes the board of the little dot in place. After this you can slide the whole board backwards as the front panel no longer obstructs the movement as only the volume control device is attached which is small enough to fit through the amplifier chassis. The wires quite often got tangled on some of the other components within the amplifier when sliding the board back so I would take care and don't yank it (I suggest using a screw driver to manipulate the wires around the components so you can slide it back far enough). Once the board is slid far enough back you can access the screws which hold the brass rings in place (2 per brass ring) easily as the 8 small circular holes on the base of the amplifier are all located directly above the screws (I always thought they were part of some sort of ventilation though it is clear they were drilled as access to attaching the screws for the brass rings). After the brass rings are removed just put it back together again  (though make sure when you put the volume knob back on that you have the volume device turned all the way to the left and that it is pointing to the 0 volume mark). After this no extenders are needed for either the front or back tubes and looks much better than having the extenders (+ saves some money).
  
 Hope this helps. Sorry for no photos but I don't fancy taking it all apart again 
  
 Btw thanks for your guide on removing the metal covers on the c3g's hypnos I decided not to use any glue and they work fine once in the adapters. (shame though that there isnt much tube glow from these c3g's)


----------



## tjw321

philiptw said:


> Hey there,
> 
> I took the exact same steps of gear acquisition as you
> 
> ...


 
 I've been getting a bit frustrated with my Mullards because I couldn't get a decent sound out of them. They're still burning in, so that could be some of it, but I just tried them for the first time with the 6H30Pi power tubes......Wow - now I understand 
	

	
	
		
		

		
		
	


	




. Maybe it's just a coincidence and they just burnt in enough just before I swapped the power tubes, but I don't care - Right now I'm enjoying Eddi Reader more than I ever have before! Of course, tomorrow I'm going to have to try her with the 6HM5s...
 There really is no end to this journey once you've started, is there? Well, except for full-blown upgraditis.


----------



## TrollDragon

Nice very nice!

The journey down the rabbit hole has only just begun. 

What gain are you running the amplifier at? They come default at 3, it wasn't until I switched mine to 5 before it started to really open up. The 10 setting got too loud too fast, so I switched mine back to 5 and that's where it has been ever since.

Something else you might want to play with because it does change the sound. I like my volume control between 10 and 11 o'clock for a really nice listening level and that's with 5 gives me.


----------



## tjw321

trolldragon said:


> Nice very nice!
> 
> The journey down the rabbit hole has only just begun.
> 
> ...


 
 I haven't tried changing the gain yet. I'm at about 10 O'Clock with my HD 600s which seemed reasonable and with four sets of drivers and two sets of power tubes I had enough variables to play with. I don't think I'll ever go back to the stock power tubes (not because they were terrible, but I don't feel any need to do that experiment any more), and I'm down to a choice between the Mullards and 6HM5s for pole position in the driver's seat - with the Voskhods taking the wheel for the occasional special circumstance (basically, if I fancy a bit of a change...). Now I think could be a good time to explore the gain switches.
  
 It's kind of funny that the plan was to play with the switches first, and then try the tubes as and when they arrived....but they all arrived within a day or two of ordering except for the ones which I paid for delivery, and came from just a few miles away. Next day delivery from Serbia to the UK was free!
  
 Thanks for the help, assistance and advice. 
	

	
	
		
		

		
		
	


	



  
 A quick question for the experts - I read somewhere that part of the tube burn-in process was getting them hot enough to activate the scavenging coating on the inside of the tube to collect up the last few molecules of non-vacuum. The last time I used the Mullards I ran them for about 8 hours so they were good and hot, but they sounded pretty rough. The next time I use them, they sound smoother than a very smooth thing. Could the burn in have continued after I stopped listening, or does there actually have to be an audio signal going through them.?


----------



## i luvmusic 2

mordy said:


> Maybe this machine will take care of the cooling of 3 6080s........
> 
> 
> 
> ...


 
 That's not gonna work it only have 7 tiny fans......


----------



## TrollDragon

tjw321 said:


> I haven't tried changing the gain yet. I'm at about 10 O'Clock with my HD 600s which seemed reasonable and with four sets of drivers and two sets of power tubes I had enough variables to play with. I don't think I'll ever go back to the stock power tubes (not because they were terrible, but I don't feel any need to do that experiment any more), and I'm down to a choice between the Mullards and 6HM5s for pole position in the driver's seat - with the Voskhods taking the wheel for the occasional special circumstance (basically, if I fancy a bit of a change...). Now I think could be a good time to explore the gain switches.
> 
> It's kind of funny that the plan was to play with the switches first, and then try the tubes as and when they arrived....but they all arrived within a day or two of ordering except for the ones which I paid for delivery, and came from just a few miles away. Next day delivery from Serbia to the UK was free!
> 
> ...


You are most welcome, LD's are great amps, explore every feature and get the sound that works for you.

The silver part of the tubes is the Getter Flash that is done at the factory with an induction heater during manufacturing. You couldn't get the tube hot enough with use and there none of the initial barrium left in the tube.

Getter Info
http://www.wikipedia.org/wiki/Getter

I don't "burn-in" tubes personally, I plug them in and enjoy right from the start, others here have an idea as to how long different tubes take to reach optimal sound.

I personally don't believe in Headphone, Cable or especially Electronic device burn-in ie DAC's, SS Amps etc...

So others might chime in here with some times for you or just do as I do, leave the tubes in and enjoy the music.


----------



## tjw321

trolldragon said:


> You are most welcome, LD's are great amps, explore every feature and get the sound that works for you.
> 
> The silver part of the tubes is the Getter Flash that is done at the factory with an induction heater during manufacturing. You couldn't get the tube hot enough with use and there none of the initial barrium left in the tube.
> 
> ...


 
 One of my early posts on Head-Fi:
  
 "I multi-task. I burn-in while listening to music...
	

	
	
		
		

		
		
	


	




"
  
http://www.head-fi.org/t/651769/the-fiio-x3-thread/4995#post_9793341
  
 This is the first time I've ever run pink noise through anything to burn it in. But with 2 pairs of head-phones, 4 sets of drivers, and 2 sets of power tubes and only a couple of hours a day to listen, I was in a hurry. 
	

	
	
		
		

		
		
	


	



  
 I have noticed that a far bigger effect than the burn in one comes from just getting the tubes seated properly. That might be where the huge improvement in the Mullards came from. I clean the contacts on my tubes with a contact cleaner when I get them, but a couple of re-insertions may well have helped improve contact - or I may just have not done a very good of seating them the first time. There are so many variables, it's just too easy to fool yourself.
  
 Anyway, whatever the reason, I'm enjoying it too much. I had to get up at 5am this morning, so staying up late (1am) last night listening to music was probably not my best idea ever. I just..didn't...want...it...to...stop.


----------



## hypnos1

sgbwill2 said:


> Hi hypnos,
> 
> It wasnt all too difficult really. All I did was I undid the screws at the back of the amplifier so the panel can partially come off (as wires still keep it attached) then I undid the alan key screws at the front and then took off the volume knob (using an alan key again as theres a small hole on the knob which has an allan key screw in it) after this you can completely remove the front cover (after detaching the volume control from the front cover by un-bolting it). After this I undid the screws on the top of the amplifier which fixes the board of the little dot in place. After this you can slide the whole board backwards as the front panel no longer obstructs the movement as only the volume control device is attached which is small enough to fit through the amplifier chassis. The wires quite often got tangled on some of the other components within the amplifier when sliding the board back so I would take care and don't yank it (I suggest using a screw driver to manipulate the wires around the components so you can slide it back far enough). Once the board is slid far enough back you can access the screws which hold the brass rings in place (2 per brass ring) easily as the 8 small circular holes on the base of the amplifier are all located directly above the screws (I always thought they were part of some sort of ventilation though it is clear they were drilled as access to attaching the screws for the brass rings). After the brass rings are removed just put it back together again  (though make sure when you put the volume knob back on that you have the volume device turned all the way to the left and that it is pointing to the 0 volume mark). After this no extenders are needed for either the front or back tubes and looks much better than having the extenders (+ saves some money).
> 
> ...


 
  
 All I can say is...WELL DONE! You did a fine job with those rings. A good deal of care is obviously needed when sliding back that board, but certainly doable.
 Luckily I have the MKIV SE, so I don't have that particular problem - our tube rings and plate come off nice and easily from the top 
	

	
	
		
		

		
		
	


	




. But I was hoping you could enlighten your fellow MKIII owners...which of course you have!!
  
 Glad you managed to remove the C3Gs from their prison...sure looks much prettier, lol! - even if there isn't much glow 
	

	
	
		
		

		
		
	


	




. But if you want _gorgeous_ glow, just take the 6AS7G high road...your mind would be blown in more ways than one - guaranteed! And your C3Gs would say a BIG "thank you"...
  
 ps. Sorry if I'm stating the obvious (again), sgb, but please be extremely careful if you remove the tube and it separates from the base...as I mentioned before, the base can _appear_ to fit on the tube in any position... just ensure the 'church windows' line up perfectly, and all is well.


----------



## hypnos1

Thought I was taking a holiday from the thread, but I just can't seem to stay away...will be in trouble 'indoors' if I'm not careful (live dangerously, I say!).
  
 However, there's a couple of points I feel I need to make :
  
 Firstly, after looking back over some of our (myriad) posts, I realised that you - *MORDY* - were way ahead of your time when you tentatively proposed using 6SN7s as power tubes...and which you - *GIBOSI * - then made possible with your experimentation with external heater power supplies.
  
 This thread and all LD I to IV owners interested in taking their amps to new heights do indeed owe you both a great debt of gratitude...and is certainly 'one in the eye' for the experienced guy who wondered why we were bothering to do what we have been doing without checking out all the pure 'technicalities' involved...had we done so, we probably would never have _dared_ to carry on, lol!
  
 Secondly, I am now fairly sure I don't need to 'move up' to a Bottlehead Crack...milosz, over on the Little Dot MKIII review thread did a very interesting A/B comparison - with the BH (plus speedball upgrade and better caps) only marginally ahead. And this with only _stock _tubes! Given my IVSE, with C3GSs and Chatham 6AS7Gs (as if you didn't know lol!) is a million miles from stock sound, I doubt VERY MUCH - IMHO -  whether the BH even matches what I am now getting. I really do believe I would need to spend BIG BUCKS to get any noticeable improvement...am I deluding myself? Possibly, but this past year with all you wonderful guys has taught me more about 'sound', its reproduction, and music appreciation than I ever imagined possible. And I can finally appreciate more as a whole the finer points regarding what my ears (and brain!) are hearing - beyond the more 'technical' aspects of sound.
 Whatever, I continue to be amazed at what this amp is now doing...and this, long after the initial 'honeymoon' effect that can often happen...
  
 Cheers to you all...
  
 Edit. Forgot to post milosz's link...silly me...:
  
http://lf.org/abtests/ns/hpamps/10.html


----------



## sgbwill2

hypnos1 said:


> All I can say is...WELL DONE! You did a fine job with those rings. A good deal of care is obviously needed when sliding back that board, but certainly doable.
> Luckily I have the MKIV SE, so I don't have that particular problem - our tube rings and plate come off nice and easily from the top
> 
> 
> ...


 
 The MKIV certainly is the way to go if adapters are to be used that's for sure, seems far less effort, though now its done I don't have to worry about it again . The 6AS7G's may be a future project for me but for now I am pleased enough with the 6SN7's sound. I agree that the C3G's are more aesthetically pleasing now that the casings have been removed. Even though there is very little tube glow it is the sound that matters the most and these certainly deliver, now that they are plugged into the adapters I don't think I'll be removing them unless they give out on me so I wont have that problem so there are no worries on that front haha


----------



## hypnos1

sgbwill2 said:


> The MKIV certainly is the way to go if adapters are to be used that's for sure, seems far less effort, though now its done I don't have to worry about it again . The 6AS7G's may be a future project for me but for now I am pleased enough with the 6SN7's sound. I agree that the C3G's are more aesthetically pleasing now that the casings have been removed. Even though there is very little tube glow it is the sound that matters the most and these certainly deliver, now that they are plugged into the adapters I don't think I'll be removing them unless they give out on me so I wont have that problem so there are no worries on that front haha


 
  
 Jolly good...now you have an LD that LOOKS better, as well as SOUNDING better...what more can you ask?...(There is _always_ more!..
	

	
	
		
		

		
		
	


	




). But all in good time, mon ami...
  
 ps. As those C3Gs were built to do a really tough job, hopefully we should NEVER have to remove them, lol!!


----------



## i luvmusic 2

What inspired me getting the CRACK is this.

 I would like to build my own amp IMO the CRACK will allow me to do that,I can say i build that.THANK YOU Artsi!


----------



## TrollDragon

i luvmusic 2 said:


> I would like to build my own amp IMO the CRACK will allow me to do that,I can say i build that.THANK YOU Artsi!


If you reall want to build your "Own" there are a ton of designs on the net that you can use. You'll have to source all the parts and learn to basically follow a schematic, you don't have to fully understand the workings of the circuit just to build the design.

IMHO It would be much more rewarding than a put part A in place A, put part B in place B type of build. It is more expensive than the Crack would be but you get to design the case and layout to your liking, within reason of course, the smaller the case the more critical the parts placement to avoid hum and noise etc...


----------



## i luvmusic 2

trolldragon said:


> If you reall want to build your "Own" there are a ton of designs on the net that you can use. You'll have to source all the parts and learn to basically follow a schematic, you don't have to fully understand the workings of the circuit just to build the design.
> 
> IMHO It would be much more rewarding than a put part A in place A, put part B in place B type of build. It is more expensive than the Crack would be but you get to design the case and layout to your liking, within reason of course, the smaller the case the more critical the parts placement to avoid hum and noise etc...


 
   I will start with the CRACK for now and believe me once i build the crack it's not gonna look like a stock CRACK,I looked around for a TRANSFORMER that i can used for a tube amp build and some of them are twice the price of CRACK that just the trans. and some RESISTORS and CAPACITORS are not cheap either IMO the crack will get me started to be more comfortable working with P2P wiring i've never done this before so hopefully i can learn some skills from the CRACK and don't closed your account here i will be sending you a lot of PM once i start this thing.LOL


----------



## i luvmusic 2

I just don't like the idea of putting all the plugs and switches on top of the AMP.


----------



## TrollDragon

i luvmusic 2 said:


> I will start with the CRACK for now and believe me once i build the crack it's not gonna look like a stock CRACK,I looked around for a TRANSFORMER that i can used for a tube amp build and some of them are twice the price of CRACK that just the trans. and some RESISTORS and CAPACITORS are not cheap either IMO the crack will get me started to be more comfortable working with P2P wiring i've never done this before so hopefully i can learn some skills from the CRACK and don't closed your account here i will be sending you a lot of PM once i start this thing.LOL







i luvmusic 2 said:


> I just don't like the idea of putting all the plugs and switches on top of the AMP.


Well then the Crack is the place to start, P2P wiring is really easy, you should have no trouble at all!

Feel free to ask away, I'll assist with whatever I can answer. There is a ton of help on the Crack forums as well and Doc B is there to answer anything technical in regards to circuit operation so you should really set up an account there as well.

No, I don't care much for connectors and knobs on the top deck either, but if I had a Decware CSP I could probably get used to the top mounted connectors and controls very easily...


----------



## gibosi

A Sylvania 6832, manufactured in 1960 and sporting a D-getter, arrived yesterday. However, in comparing my Sylvania 6832 to pictures of the Raytheons on eBay, I am quite sure that mine was also manufactured by Raytheon and simply rebranded. Like my 7963, I mounted the 6832 into an octal base, but this time, I thought I should try to improve my technique. Inspired by Mordy, I used heat shrink tubing. I think it looks a _little_ better. lol 
  
 Sylvania 7963                                                                       Sylvania (Ratheon) 6832
  

  
 I listened to it for about an hour last night and even right out of the box, it sounds very good. As usual, I will wait until it has considerably more hours on it before I do any critical listening, but my first impression is the 6832 is a bit brighter and more forward than the 7963.


----------



## TrollDragon

Still at the back of the bus here, with a pair of 6GU7's as power tubes.


----------



## i luvmusic 2

trolldragon said:


> Well then the Crack is the place to start, P2P wiring is really easy, you should have no trouble at all!
> 
> Feel free to ask away, I'll assist with whatever I can answer. There is a ton of help on the Crack forums as well and Doc B is there to answer anything technical in regards to circuit operation so you should really set up an account there as well.
> 
> No, I don't care much for connectors and knobs on the top deck either, but if I had a Decware CSP I could probably get used to the top mounted connectors and controls very easily...


 
 Good to know and THANK YOU SIR!


----------



## i luvmusic 2

trolldragon said:


> Still at the back of the bus here, with a pair of 6GU7's as power tubes.


 
 You should really try the Raytheon 6832 they are cheap and sound really nice.PM  me i have one extra.


----------



## mordy

Hi,
  
 Finally received the second 5A voltage regulator and rigged up two Stromberg-Carlson 6080 (nee RCA) tubes from May, 1960 as power tubes. The trusty Raytheon JAN 6832 from September 1957 serves as the driver.
  
  
  The voltage regulators, although looking alike, display different numbers even though the readout at the tube pins is 6.29-6.31V (hard to set exactly).                                                                                                                                                                                                                                                                                               
  
 Here is a night view of 5.4A of fire power:
  

  
 And a closeup of the orange lightning rods:
  

  
 First impression: With an amplification factor of 2 I am running the LD at full tilt at 5:45 on the volume control. With the A/C on and an ambient room temperature of 73F with the external fan drawing away air from the amp, the amp after one hour  is barely warm to the touch. The tubes need perhaps 30 min to come into their own. (Don't know if these are used or new. Just like TD I am enjoying them right away, but IMHO tubes improve after burn-in, and they may sound better later.
  
 The sound is open and sweet with a wide luscious sound stage. I can "see" into the recording and hear things I did not hear before. It is as if there are layers of music added. The highs are gorgeous, and the bass is very detailed and tuneful and really strong and powerful.
  
 There is not more hum than before; only when I turn it up very loud without music playing. Can somebody advise me if I need to ground the second voltage regulator to the chassis the same as the first one?
  
 End game?


----------



## hypnos1

mordy said:


> Hi,
> 
> Finally received the second 5A voltage regulator and rigged up two Stromberg-Carlson 6080 (nee RCA) tubes from May, 1960 as power tubes. The trusty Raytheon JAN 6832 from September 1957 serves as the driver.
> 
> ...


 
  
 Hi mordy.
  
 Thought you would be bowled over with your second 6080 in place...who would have believed we could squeeze such a sound out of our LDs?...I really cannot see how we could push things any further...some WE 421As perhaps?...at their prices, you're on your own I'm afraid!!
  
 The journey has indeed borne fruit aplenty, and has been a very enjoyable one in addition...I wish you continued  HAPPY LISTENING...methinks 'ROLLING' is now less appropriate - more's the pity, lol!
  
 Cheers.
  
 C.J.


----------



## gibosi

mordy said:


> Hi,
> 
> Finally received the second 5A voltage regulator and rigged up two Stromberg-Carlson 6080 (nee RCA) tubes from May, 1960 as power tubes. The trusty Raytheon JAN 6832 from September 1957 serves as the driver.
> 
> ...


 
  
 Perhaps TD will weigh in here, but I believe tying all external PS's and the amp to a common ground is best practice.
  
 End game? In the 6AS7 forum, there is considerable consensus that an RCA 6AS7 is superior to all but very few (and expensive) 6080. Given your self-imposed limit of $8 per tube, I would guess that the RCA 6AS7 may well be your end game. But who knows? Sometimes eBay "sleeps", and you may be able to snag a pair of Tung-Sol/Chatham 6AS7's for cheap....
  
 Cheers


----------



## TrollDragon

You should be able to connect the negative output of one regulator to the negative output of the other and then carry that wire onto the chassis screw.


----------



## mordy

I just did that, before I read your post. Did not notice a reduction in high volume hum. Anyhow, I want to thank you all for your kind words and encouragement.
  
 I have one RCA 6AS7 from Dec 1973. I could try it together with the RCA 6080 or look for a second one. Recently, somebody closed out a whole bunch of 6AS7 tubes and the prices and demand went down temporarily, and I was able to buy this tube (from a different source) for a couple of bucks.
  
 As hypnos 1 writes, it is amazing how much more we have been able to get out this humble little amp. However, in the sense of fairness I cannot take any credit for coming up with the idea of using 6SN7 tubes for power tubes. I think one of the first people to try it was Artsi with Russian 6SN7 equivalents. All the ideas with extenders, voltage regulators, and pulling the wires through a drilled hole in the extender came from knowledgeable people on this forum. The heat shrink trick I got from YouTube.
  
 I did discover the 6832 tube, but the credit goes to Oskari who provided a link to an extensive list of  sub miniature tubes with specs. I picked out a dual triode with specs similar to the 6SN7 tube. Actually, I picked out half a dozen tubes, and then scanned Ebay to see what was available. Some of them I could not find, and the 6832 was the best buy.
  
 Part of the fun of tube rolling in my case is to find unknown and/or inexpensive tubes with superior sonic characteristics. (And a secret desire to turn my MKIII into a MK9).
  
 Could be that this goal has been met - the sound I now get from my amp feels just right and continues to astound me. Saw a post of somebody selling 900 pieces of the 6832s for $1800. Wonder if David Zhe Zhe would be receptive to build a modified MKIII with this tube as driver. Nah, the little bugger does not have any visual impact... Maybe install a dummy orange glow tube LOL!


----------



## TrollDragon

That orange glow tube is a voltage regulator of the sub 100V variety, they have no filaments and are filled with gas.

Basically a tube version of the Zener diode.


----------



## mordy

Thanks TD - I just thought it would be a good suggestion to get the visual appeal for a tube amp using the tiny subminiature tube as a driver....


----------



## gibosi

Similar to Mordy, I reviewed the list of sub-miniatures that Oskari provided, and based on specifications, availability and documented use in audio applications (per Google), I believe the 7963, 6832 and 6021 are the best choices to run in our Little Dots. Indeed, a number of us have already found the 6832 to be a very good tube. And if you are willing to take my word for it, the 7963 is also a very good tube. This leaves the 6021.
  
 So.... In this morning's mail, a Sylvania Gold Brand 6021A arrived, manufactured in 1961 and sporting a D-getter. A search on eBay for this tube reveals that all the major US brands and a couple of European brands marketed this tube. As there exists a Sylvania datasheet for the 6021, I am quite certain that Sylvania did, in fact, manufacture this tube. However, I do not know if all these other companies manufactured their own tubes, or if they are simply rebrands. By way of comparision, I am quite sure that only Sylvania manufactured the 7963 and only Raytheon manufactured the 6832...
  
 Fortunately, the 7963, 6832 and 6021 all have the same pin-out, so once you figure out how to mount one into your base of choice, mounting the others should be easy. I intend to mount this tube into an octal base, like the 7963 and 6832. However, the 6021 has another little wrinkle that the others apparently do not have, a Russian counterpart, the 6N16B. And wouldn't you know, the pin-out on the Russian tube is different! Moreover, there exists an ultra premium version, the 6N16B-VR, which has 9 leads, instead of 8, the extra lead being attached to an electrostatic shield. According to a number of reports via Google, this ultra premium Russian tube is better than any of the US-made 6021's. I have some on their way to me from Russia... and with some luck, they might arrive before the snow falls. lol 
  
 In the meantime, I am curious to learn how this 6021 compares to the 7963 and 6832.


----------



## Oskari

mordy said:


> I did discover the 6832 tube, but the credit goes to Oskari who provided a link to an extensive list of  sub miniature tubes with specs.


 
  
 I don't think I did. Have I completely forgotten? Perhaps it was Artsi.


----------



## gibosi

Well..... here it is again, if anyone is interested:
  
 http://pw2.netcom.com/~wa2ise/radios/penciltubes.html


----------



## hypnos1

mordy said:


> I just did that, before I read your post. Did not notice a reduction in high volume hum. Anyhow, I want to thank you all for your kind words and encouragement.
> 
> I have one RCA 6AS7 from Dec 1973. I could try it together with the RCA 6080 or look for a second one. Recently, somebody closed out a whole bunch of 6AS7 tubes and the prices and demand went down temporarily, and I was able to buy this tube (from a different source) for a couple of bucks.
> 
> ...


 
  
 So, mordy, we have artsi (wherever he is now!) to thank...but don't sell yourself short my good man - you were indeed instrumental in bringing the 6SN7 more into focus...
  
 And, of course, my comments re *GIBOSI* 's work on external heater power supplies should be aimed more at enabling the use of 6AS7G/6080 as power tube  (a leap equalled only by the C3G as driver, and now the sub-miniatures) - the 6SN7s not needing it of course...


----------



## mordy

Extra points if you can identify this "tube"
  

  




 (Another example of same)


----------



## hypnos1

trolldragon said:


> Still at the back of the bus here, with a pair of 6GU7's as power tubes.


 
  
 Hey there TD...what's this "back of the bus" stuff? The enthusiast that you are should have you right at the FRONT, lol!
  
 Que pasa, mi amigo?! 
	

	
	
		
		

		
		
	


	




.


----------



## Oskari

mordy said:


> Extra points if you can identify this "tube"


 
  
 Videos of these are pretty awesome. (Plenty on youtube.)


----------



## tjw321

mordy said:


> Spoiler: Warning: Spoiler!
> 
> 
> 
> ...


 
 It's a mercury arc rectifier. But I don't know any more than that...


----------



## Oskari




----------



## TrollDragon

mordy said:


> Extra points if you can identify this "tube"


 
 Mercury Arc Rectifiers... Honking BIG diodes... 
	

	
	
		
		

		
		
	


	



  
 Here are the type we would use as opposed to the massive Subway power system beasties.

  
 There are many models...
 http://www.ebay.com/itm/816-mercury-vapor-rectifier-tubes-NOS-RCA-USA-2-pcs-/331235569819


----------



## TrollDragon

hypnos1 said:


> Hey there TD...what's this "back of the bus" stuff? The enthusiast that you are should have you right at the FRONT, lol!
> 
> Que pasa, mi amigo?!
> 
> ...


 
 My enthusiasm is high but unfortunately my wallet does not share the same искренний энтузиазм.


----------



## MIKELAP

trolldragon said:


> My enthusiasm is high but unfortunately my wallet does not share the same искренний энтузиазм.


 
 The empty wallet syndrome terrible condition a high percentage of people affected by this ,i share your pain .


----------



## TrollDragon

mikelap said:


> The empty wallet syndrome terrible condition a high percentage of people affected by this ,i share your pain .


 
 Thanks Bro!


----------



## mordy

Hi,
  
 Yep, you all got it right on the first try! Those contraptions look pretty scary...
  
 A *mercury-arc valve* or *mercury-vapor rectifier* or (UK) *mercury-arc rectifier*[1][2] is a type of electrical rectifier used for converting high-voltage or high-current alternating current (AC) into direct current (DC). It is a type of cold cathode gas discharge tube but is unusual in that the cathode, instead of being solid, is made from a pool of liquid mercury and is therefore self-restoring. As a result, mercury-arc valves were much more rugged, long-lasting and could carry much higher currents than most other types of gas discharge tube.
 Invented in 1902 by Peter Cooper Hewitt, mercury-arc rectifiers were used to provide power for industrial motors, electric railways, streetcars, and electric locomotives, as well as for radio transmitters and for high-voltage direct current power transmission. They were the primary method of high power rectification before the advent of semiconductor rectifiers such as diodes, thyristors and gate turn-off thyristors (GTOs) in the 1970s.


----------



## i luvmusic 2

OK i'am lost except for the empty wallet syndrome.


----------



## hypnos1

trolldragon said:


> My enthusiasm is high but unfortunately my wallet does not share the same искренний энтузиазм.


 
  
 Now you come to mention it TD, I dare not even look back over the past year and add up all the 'bits and pieces' lol!!
  
 Perhaps we should all enrol at Professor mordy's school for impoverished vacuum tube rollers?...
  
 Ah well... still cheaper than golf... or is it?!


----------



## TrollDragon

Well the middle of the road course down the road from where I work is $1200 a year for membership. I think that gives you 40 rounds and the wind never stops blowing there off the ocean.


----------



## mordy

Hi hypnos 1,
  
 Don't take me wrong, I _could_ spend more, but I enjoy the extra challenge in finding a good buy. It gives me additional satisfaction that I am using less than $15 worth of tubes to get superior sound. Never mind that it took a few hundred tubes and $$$ to get there - that's part of the fun of tube rolling!
  
 My wife asked me why I need so many tubes. So of course I tell her that we are looking for audio perfection, and besides, these tubes become more valuable as time goes on (bluff!)
  
 There are some tubes that are desirable in people's eyes, either because they really are superior or because they are hyped up by vendors.
 The rest are not so easy to sell, especially since I don't have a tester and can only ascertain that they work.
  
 The 6080s work, and the pair I selected from having used them as drivers works very well. I stuck in two pieces of wood (Chinese chop sticks) between the transformer housing and the piece of wood the voltage regulators are mounted on for better ventilation. The amp has been going 11-12 hours with the fan doing it's thing, and it is just slightly warm to the touch - looks like the spacing helped. With proper ventilation and a room temperature around 70-73F heat doesn't seem to be a concern.
  
 I have in mind to make a solderless adapterless adapter for the 6832 if you get the gist. Thinking of extending the flexible leads 2" with 0.8mm copper wire using shrink wrap tubing and inserting the leads directly into the two driver tube sockets. To facilitate the correct mounting in the sockets I will use two Mullard plastic pin protectors. It might look better as well.
  
 Continuing to enjoy the RCA 6080 tubes. The instrument separation is so well defined that I can concentrate on one instrument in a band and follow the playing.


----------



## CITIZENLIN

superdux said:


> Hi, i found the seller to be very friendly but we also had one tube with a slightly cracked base holding the pins but which still worked.I hope you get to enjoy your C3G's very soon.I have experienced them to be very resolving with good presentation of freq. spectrum.


 

 Update on adapters
  
 I just received replacement adapters. EB seller "happydiy998" sent me replacement pair of adapters via DHL EXPRESS. Took 6 days because of the weekend. Vanessa was the one helped me out with the whole process and upgrade china post to DHL express. Now i just have to listen to them as soon as I get home... can't wait.  Thank you everyone here for your inputs.
 Thank you again to Vanessa @ happydiy998.


----------



## sgbwill2

Hi guys,
  
 I am very happy with my current set-up of c3g's and 6sn7's however my curiosity is starting to get the better of me (again) and was wondering if anyone has used 6f8g or 6c8g as power tubes instead of the 6sn7's? They can be directly swapped out with the 6sn7's along with the appropriate adapter and no external heaters are needed (6f8g's 0.6 and 6c8g's 0.3 and 6sn7's 0.6). Would the 6f8g's be more compatible seen as they have a 0.6 draw-up instead of the 0.3 of the 6c8g's? If anyone has experience with both the 6f8g's and 6c8g's what are the differences between the two and what one would work best in the LD MKIII?
  
 Thanks


----------



## MIKELAP

citizenlin said:


> Update on adapters
> 
> I just received replacement adapters. EB seller "happydiy998" sent me replacement pair of adapters via DHL EXPRESS. Took 6 days because of the weekend. Vanessa was the one helped me out with the whole process and upgrade china post to DHL express. Now i just have to listen to them as soon as I get home... can't wait.  Thank you everyone here for your inputs.
> Thank you again to Vanessa @ happydiy998.


 
 i bought adapters from them before even if sometimes they dont work they always make it right .


----------



## gibosi

sgbwill2 said:


> Hi guys,
> 
> I am very happy with my current set-up of c3g's and 6sn7's however my curiosity is starting to get the better of me (again) and was wondering if anyone has used 6f8g or 6c8g as power tubes instead of the 6sn7's? They can be directly swapped out with the 6sn7's along with the appropriate adapter and no external heaters are needed (6f8g's 0.6 and 6c8g's 0.3 and 6sn7's 0.6). Would the 6f8g's be more compatible seen as they have a 0.6 draw-up instead of the 0.3 of the 6c8g's? If anyone has experience with both the 6f8g's and 6c8g's what are the differences between the two and what one would work best in the LD MKIII?


 
  
 The 6F8G preceded the 6SN7, and electrically, the two are virtually the same. And the 6C8G preceded the 6SL7, and electrically, these two are virtually the same, as well. Like the 6SL7, the 6C8G with .3A heaters doesn't move enough current to perform well as a power tube. The 6F8G, being virtually the same as the 6SN7, won't perform any better or any worse. The only real advantage is it gives you a few more tubes to roll  
  
 I would suggest that you follow in the footsteps of Hypnos1 and Mordy and try a pair of the 6AS7 or 6080. A cheap pair of RCA 6AS7 would be a major improvement over the 6SN7.


----------



## sgbwill2

gibosi said:


> The 6F8G preceded the 6SN7, and electrically, the two are virtually the same. And the 6C8G preceded the 6SL7, and electrically, these two are virtually the same, as well. Like the 6SL7, the 6C8G with .3A heaters doesn't move enough current to perform well as a power tube. The 6F8G, being virtually the same as the 6SN7, won't perform any better or any worse. The only real advantage is it gives you a few more tubes to roll
> 
> I would suggest that you follow in the footsteps of Hypnos1 and Mordy and try a pair of the 6AS7 or 6080. A cheap pair of RCA 6AS7 would be a major improvement over the 6SN7.


 
 Thanks for your reply. I would like to try the 6AS7's though I'm not confident enough about fitting external heaters. I think I may try the 6F8G's just out of curiosity and see how I like them 
  
 btw are there any further alternatives without external heaters?


----------



## TrollDragon

Now someone needs to try a FETRON as a driver. 2C51 / 396A / 407A pinout with no heater connections required. 
	

	
	
		
		

		
		
	


	



  

 http://www.ebay.com/itm/1x-Teledyne-FETRON-dual-triode-direct-replacement-of-WE396A-407A-tube-/271510171780
  
 Information Manual
 http://www.lib.radionostalgia.ca/Unsorted_Book/Unsorted/FETRON_Solid_State_Vacuum_Tube_Replacement.pdf


----------



## mordy

Another update on 6832 + RCA 6AS7G and RCA 6080. Put in the the two different power tubes. By moving my office chair (on wheels) and positioning myself in front of the right and left speakers alternatively I can A/B the tubes. (Works especially well with a good quality mono recording) It is also possible to move the balance control right or left, but moving the sweet spot works better for me.
  
 David, Goliath and Sixty Eighty: (Taken with flash)
  

 A closer view:

 And the obligatory night view in honor of the Orange Glow Tube Society (Try that with a Fetron!  - "The best thing since the West was won!")

 OK, back to the serious stuff. I can definitively hear a difference between the power tubes. The 6AS7G is warmer and has beautiful timbre, but the bass is less powerful and more recessed and somewhat muffled. In addition, it allows for more front to back depth of the sound stage.The 6080 goes lower and is harder hitting. It has stronger bass and more slam and attack, as well as being more forward and open sounding. The amount of detail seems to be the same.
  
 Since I started listening to these 2.5A power tubes the various musicians on different recordings started to talk to each other (or shout) much more during the recordings - don't know why they were quiet before!
  
 "If it ain't got that swing it ain't got a thing." That thing for me is superior bass performance. In this shootout the nod goes to the Stromberg-Carlson (RCA) 6080 tube. (Possibly other 6AS7 tubes could best them.)
  
 I am also starting to realize the impact power tubes have on the sound. Conventional wisdom has it that the power tubes account for 15% of the sound. The same conventional wisdom has it that if you increase horsepower in an engine 5% you don't notice it, but if you lose 5% horsepower you feel it right away. IMHO the power tubes lay the rhythmic bass foundation for the music. Having tasted superior bass performance I now know what I have been missing, and there is no going back.....In addition, the power tubes affect the overall sound as well. In sum, the effect of power tubes is an all encompassing effect and not necessarily quantifiable, but still highly significant in the overall musical presentation.


----------



## hypnos1

citizenlin said:


> Update on adapters
> 
> I just received replacement adapters. EB seller "happydiy998" sent me replacement pair of adapters via DHL EXPRESS. Took 6 days because of the weekend. Vanessa was the one helped me out with the whole process and upgrade china post to DHL express. Now i just have to listen to them as soon as I get home... can't wait.  Thank you everyone here for your inputs.
> Thank you again to Vanessa @ happydiy998.


 
  
 Am really glad things are beginning to look up for you...you will forget all about this hiccough once you hear what the C3Gs can do, lol! 
	

	
	
		
		

		
		
	


	




.
  


mordy said:


> Another update on 6832 + RCA 6AS7G and RCA 6080. Put in the the two different power tubes. By moving my office chair (on wheels) and positioning myself in front of the right and left speakers alternatively I can A/B the tubes. (Works especially well with a good quality mono recording) It is also possible to move the balance control right or left, but moving the sweet spot works better for me.
> 
> David, Goliath and Sixty Eighty: (Taken with flash)
> 
> ...


 
  
 Hey mordy...looks like I'm gonna have to give the 6080s a try after all. Even if only for interest's sake! (My wallet does NOT thank you,though!! - apparently only top-notch 6080s might beat my Chatham 6AS7Gs, and mainly the rather expensive (and rare) graphite plate/column versions. But I shall try some of _your_ tactics, and perhaps I'll get lucky...
  
 Am glad you have confirmed my previous what-I-thought-to-be-heretical statements re. the importance of power tubes in the overall sound...the difference is beyond doubt AND question, not to mention BELIEF lol!
  
 'Tis funny you should mention musicians "talking/shouting" to each other (not literally I presume!)...but today I popped in a CD of a (very old) Peter, Paul and Mary recording - please don't laugh, they were a very talented trio (IMO!) - and I heard a slight whispering at the beginning of a track that I had never heard before...I was gobsmacked, to say the least. And despite some rather dubious sound engineering - not to mention "limitations in the Master Tape" - the overall sound left me even more dumbfounded. What this amp keeps on producing now just continues to scramble my brain...detail retrieval especially is phenomenal - I make no apologies for all the superlatives! I can only urge EVERYONE to go the extra mile and give these power tubes a try...you would NOT regret it....ask mordy...and iluvmusic2...and ???


----------



## i luvmusic 2

Hi Mordy,
   You should try 6080/6AS7G driver tube with 6080/6AS7G power tubes you may like this setup i've tried this and it sounds nice IMO.


----------



## mordy

Hi hypnos 1,
  
 When I said talking/shouting I meant literally. I listen to classic jazz from the twenties and New Orleans Jazz, and it is not unusual that a musician will talk to another one or even shout something while performing, especially during a live recording. However, with these tubes I heard things I did not notice before.
  
 How can I tell a graphite tube from a regular one? I have six different RCA 6080's, and only one real pair. The construction in five of them is slightly different from tube to tube.
  
 Hi i lovemusic 2,
  
 I am certainly willing to try three 6080's or two + the 6AS7. I hope that the third voltage regulator which is rated 2-3A is powerful enough.


----------



## gibosi

mordy said:


> How can I tell a graphite tube from a regular one? I have six different RCA 6080's, and only one real pair. The construction in five of them is slightly different from tube to tube.


 
  
 To my knowledge, only Bendix manufactured 6080 with graphite plates. However, they were often rebranded and sold under other labels.
  
 Here are some pictures:
  
 http://the-key.enix.org/~krystal/review-tube-bottlehead.html
  
 and here:
  
 http://www.head-fi.org/t/410326/for-6as7g-tube-rollers-here/1350#post_10625059
  
 From the pictures, it is difficult to see the difference between graphite and metal, but up close, graphite plates appear to be carved out of a solid block of material and look rather different than formed sheet metal.


----------



## i luvmusic 2

mordy said:


> Hi hypnos 1,
> 
> When I said talking/shouting I meant literally. I listen to classic jazz from the twenties and New Orleans Jazz, and it is not unusual that a musician will talk to another one or even shout something while performing, especially during a live recording. However, with these tubes I heard things I did not notice before.
> 
> ...


 
  You should get one 12A regulator so at least you can run higher current tubes without worries for regulator.My favourite set up is two RCA 6AS7G and one G.T.C./Chatham 6AS7G this set up gave plenty of Bass my DT880 600 Ohms love this set up but not so much for my Q7X1 it's boomy however i don't want to run this set up no longer than 1.5 hours due to heat issue i've tried the fan thingy and IMO did not make that much deference.


----------



## TrollDragon

Mmmmm Graphite Plates.


----------



## i luvmusic 2

No offense they maybe shiny and expensive but i prefer the look of the 6AS7G's(coke bottle) unless they make a gigantic curvy bottle  tubes with tons of pencil leads in it.


----------



## mordy

Thanks all for elucidating me on graphite tubes. One thing is sure - I ain't got any!
  
 Regarding the 12A voltage regulator: Is one enough to drive three 6080s? Could u provide a link?
  
 Re the fan: First I used a 3" fan that helped somewhat but was not adequate. Afterwards I installed a 4" fan close above the amp and the tubes, pulling away the air. Then I moved out the piece of wood that houses the voltage regulators from resting on the transformer housing. At this point the temperature dropped from hot to slightly warm, and I have no concern running the amp for extended hours. Perhaps the placement of the fan and the location of the amp has to be taken into consideration. It also helps to keep the room cool at 73F or so.


----------



## TrollDragon

i luvmusic 2 said:


> No offense they maybe shiny and expensive but i prefer the look of the 6AS7G's(coke bottle) unless they make a gigantic curvy bottle  tubes with tons of pencil leads in it.


 

 Sorry but the KR T-1610 trumps any ST tube by a mile...


----------



## mordy

KR T-1610MATCHED PAIR  $2499.00The T-1610 is an ultra-linear, low frequency, high power triode tube capable of producing 22-45 watts of pure class-A power. The T-1610 is an exceptional tube for those special applications requiring 50 watts or more of class-A power. Recommended for new designs only. There is no other tube currently in production like Kronzilla, the T-1610 power tube. There may be bigger transmitting tubes that one can convert to audio operation, but the T-1610 is a true triode designed specifically by KR Audio for audio use.  All KR Enterprise tubes are warranted for a period of 2 years.
  
 Doesn't look like I could use it in the LD amp .....


----------



## mordy

Hi i luvmusic 2,
  
 Tried your suggestion of using 6080/6AS7 tubes. Cobbled together another voltage regulator PS with my old 2-3A voltage regulator. Here is a picture of the experimental set up:
  
 After some trial and error and a dead right channel with large hum I got everything to work, sort of. The sound is OK, but not as good as my previous set up, and I miss the sound of the 6832.  The volume on the LD has to be full tilt because of the low amplification factor. The entire set up was very quiet, maybe because of the low amplification factor.
  
 Keeping a watchful eye on the nixie readout on the 2A regulator, I noticed that the voltage kept on dropping slowly. When I touched the microchip above the first number it was burning hot. If I understood the information correctly that came with the regulator, 3A operation requires a heat sink on top of the microchip, but it did not come with it, unlike the 5A voltage regulators. There is some kind of overload protection, but I didn't want to take a chance, and pulled the plug.
  
 I'm glad I tried, but now I am going back to my previous set up.
  
 What's next? Just plugged in everything again, and listened to a recording that I have heard numerous times over several decades (4). Guess what? I heard something new that I did not notice before - this fantastic resolution of micro details is astounding......Add to this that the presentation is completely natural and musical, and not analytical with any kind of etched quality.


----------



## i luvmusic 2

I just purchased the CRACK with SB sorry for my wallet tho..........
	

	
	
		
		

		
		
	


	



 Wish me luck building this kit i might screw it up like what i did with those regulators.


----------



## gibosi

i luvmusic 2 said:


> I just purchased the CRACK with SB sorry for my wallet tho..........
> 
> 
> 
> ...


 
  
 Have fun! Personally, I think it is a great little amp. And in fact, it was at the top of my list until I found out that it was not recommended for headphones with an impedance of less than 200 ohms. Too bad.....


----------



## TrollDragon

i luvmusic 2 said:


> I just purchased the CRACK with SB sorry for my wallet tho..........
> Wish me luck building this kit i might screw it up like what i did with those regulators.


Congratz!

If you screw it up just pop it in the mail and I'll fix it for you... It might take quite a bit of audition time before its all good to ship back though... 

Seriously if you need any help just PM me instead of messages here since they would be OT and might make the others a little jealous, all except for "Mista Woo" of course since he has a WA2.


----------



## i luvmusic 2

gibosi said:


> Have fun! Personally, I think it is a great little amp. And in fact, it was at the top of my list until I found out that it was not recommended for headphones with an impedance of less than 200 ohms. Too bad.....


 
 It took me awhile to decide what i really want to do build my own vs the crack i choose the CRACK due to it's price range.Thanks!


trolldragon said:


> Congratz!
> 
> If you screw it up just pop it in the mail and I'll fix it for you... It might take quite a bit of audition time before its all good to ship back though...
> 
> ...


 
 For sure you will get a lot of PM from me once the CRACK arrived.Thanks!


----------



## MIKELAP

trolldragon said:


> Congratz!
> 
> If you screw it up just pop it in the mail and I'll fix it for you... It might take quite a bit of audition time before its all good to ship back though...
> 
> ...


 
 You called !


----------



## TrollDragon

mikelap said:


> You called !


Nope just making sure you were still around...


----------



## gibosi

Mikelap! It's good to know that you are still around! 
  
 I was able to spend some time with two sub-miniatures earlier today, the 6021 and the 7923. Both were manufactured by Sylvania, but some 15 years apart, the 6021 in 1961 and the 7963 in 1976, and as expected they share the Sylvania "house" sound, great bass, extended highs and silky smooth mid-range. They are so similar that, at least for me, comparison was very difficult. After a time, I did notice a difference, but I had a tough time trying to figure out just what it was. There was something about the 6021 that just didn't seem right to me. Finally, with the help of Diana Krall, Live in Paris, I realized that it was the tonality of her voice, and the mid-range in general. The 6021 puts a bit of a bloom or lushness onto her vocals, and to my ears, mid-range detail is slightly obscured. Therefore, I prefer the 7963 to the 6021.
  
 This is not to say that the Sylvania 6021 is a bad tube. But considering that both are quite cheap, I would recommend the 7963 over the 6021, and especially to you, Mikelap! I really think you should roll a pair of these little guys into your Woo!


----------



## mordy

Hi Gibosi,
  
 Did you have a chance to compare the 7963 to the Raytheon 6832?  It is till available for a song....


----------



## gibosi

mordy said:


> Did you have a chance to compare the 7963 to the Raytheon 6832?  It is till available for a song....


 
  
 I have a Raytheon 6832 (rebadged as a Sylvania) and comparing it to the 7963 is on my to do list.


----------



## kvtaco17

i luvmusic 2 said:


> I just purchased the CRACK with SB sorry for my wallet tho..........
> 
> 
> 
> ...


 
 The Crack is a fun build! The only reason I didn't keep it was because everything I had at the time, minus the HD800 and DT990 were 32-40 ohm cans...


----------



## TrollDragon

Tension is hot, there is Schiit in the works.

Pictures later...


----------



## i luvmusic 2

trolldragon said:


> Tension is hot, there is Schiit in the works.
> 
> Pictures later...


 
 What are you up to Sir?


----------



## i luvmusic 2

Oops! never mind i can wait.........


----------



## MIKELAP

trolldragon said:


> Tension is hot, there is Schiit in the works.
> 
> Pictures later...


----------



## TrollDragon

Well today I received a very generous care package from ILM2, when I opened the box not only did I find a 6832 tube inside but an octal socket, terminal strips and some heat shrink tubing.
 What a well thought out ready to assemble package, props to you for including all the extra stuff!

  
 The cute little 6832, is this thing ever tiny. 
	

	
	
		
		

		
		
	


	





 So how I assembled this was to take an empty octal tube base, the socket ILM2 provided fits just perfectly inside and rests on the shoulder of the tube base like they were made to go together.
  
 1. Apply some heat shrink pieces to the legs of the tube leaving about 1" free at the bottom.
 2. Bend the tangs over on the bottom of the octal socket since they are just on the edge of touching the tube base connectors 
 3. Feed all the wires through the center hole of the socket, if you can arrange the wire layout first it helps with assembly of the base section.
 4. Double check your wire layout and slide the base up on the wires making sure to feed each wire into its appropriate hole.
 5 You will end up with an inch of tube wire sticking out of each hollow pin, pull gently to even up any that look short.
 6. Solder each pin and your done.
 7. Plug it in and enjoy!
  
 The 6832 all aglow in its base.

  

 Since these picture were taken I have replace the 6GU7 power tubes with the original 6H30Pi-EB's as the outpul level was too low with the other tubes.
  
 Tested with Rainbow's "Temple of the King" amazing song, RIP Ronnie James Dio.

  
 So far this is a very nice sounding little tube right out of the box, much more music will be put through it this weekend.
  
 Much Thanks to ILM2 for sharing a great little tube!


----------



## gibosi

trolldragon said:


> So how I assembled this was to take an empty octal tube base, the socket ILM2 provided fits just perfectly inside and rests on the shoulder of the tube base like they were made to go together.
> 
> 1. Apply some heat shrink pieces to the legs of the tube leaving about 1" free at the bottom.
> 2. Bend the tangs over on the bottom of the octal socket since they are just on the edge of touching the tube base connectors
> ...


 
  
 What a great idea! Very clean, neat and professional looking, especially compared to my latest and greatest! lol 
  

  
 I have some a couple sockets and a few extra bases and will try this technique when my 6N16B's finally arrive. Thanks for sharing!


----------



## TrollDragon

Thanks gibosi!

You are most welcome, this is a semi permanent type build since you would have to desolder the pins to change the tube later. Check the height of the base with the socket in it for heat shrink length, this pair worked at 1". I just placed the tube beside the assembled pieces, bottom of the tube flush with the top and measured to just before the edge of the base bottom. The socket does not have to be glued in place as the soldered tube holds it in snug. Also putting the wires into the pins can be a little fiddly but is very doable if you hold your tongue the right way and mutter a few choice words during the process. 

Enjoy a nice clean build with your next sub miniatures.


----------



## i luvmusic 2

trolldragon said:


> Well today I received a very generous care package from ILM2, when I opened the box not only did I find a 6832 tube inside but an octal socket, terminal strips and some heat shrink tubing.
> What a well thought out ready to assemble package, props to you for including all the extra stuff!
> 
> 
> ...


 
 You're welcome! That thing is a beauty nice and clean......


----------



## i luvmusic 2

It's a little quiet here today.........


----------



## gibosi

trolldragon said:


> You are most welcome, this is a semi permanent type build since you would have to desolder the pins to change the tube later. Check the height of the base with the socket in it for heat shrink length, this pair worked at 1". I just placed the tube beside the assembled pieces, bottom of the tube flush with the top and measured to just before the edge of the base bottom. The socket does not have to be glued in place as the soldered tube holds it in snug. Also putting the wires into the pins can be a little fiddly but is very doable if you hold your tongue the right way and mutter a few choice words during the process.


 
  
 This evening I tried to mount a sub-miniature in this way, but I failed miserably when it came to putting the wires into the pins. It would seem that I am lacking the necessary dexterity and patience, or perhaps I just didn't hold my tongue the right way or say the correct words. lol 
  
 So as usual, I'm back to easy and ugly again.


----------



## i luvmusic 2

This waiting time is killing me.....
	

	
	
		
		

		
			




 I already have the aluminum plates cut for the crack and no amp yet.


----------



## i luvmusic 2

gibosi said:


> This evening I tried to mount a sub-miniature in this way, but I failed miserably when it came to putting the wires into the pins. It would seem that I am lacking the necessary dexterity and patience, or perhaps I just didn't hold my tongue the right way or say the correct words. lol
> 
> So as usual, I'm back to easy and ugly again.


 
 I've tried to do the same This morning and i give up.


----------



## TrollDragon

The key is to have all your wires in a circular pattern. Put the tube wires through the socket top. Then I separated the two halves, brought 3 & 6 forward to plug into 7 & 8 then arranged the 123 side then the 456 side, bending the wire in a circular shape. Line up each wire with the holes and slide the plug up to the socket.

To help with arranging the wires, try flipping over the plug so the pins are up and use that as a form to assist in bending the wires, then turn it over and slide it on. Also a little stick or screwdriver to assist in guiding the wires to the holes might help. Hold the tube inplace with a little masking tape across the top to each side of the socket if it moves around.

Snug your wires up, not too tight and solder, the pins do take quite a bit of heat. 

Trim off the excess poking through the pins and bob's your uncle!

It's a bit of a pain that whoever designed the tube didn't follow a standard dual triode pinout.


----------



## gibosi

This evening, I was able to take some time to directly compare my Raytheon 6832 and Sylvania 7963. I found the sound signature of these two tubes to be quite similar with the 6832 being just a tad bit brighter.  In this regard I did not prefer one over the other and consider these tubes about equal.
  
 However, in terms of stage and imagery, they were much more different. The 6832 seemingly transports you to a performance space that is somewhat two-dimensional and flat. There is no real sense of depth or height. On the other hand, with the 7963, the performance space is wide, deep and tall. There is a palpable sense of space around the vocalists and instruments, and one can easily pinpoint their locations. For this reason, I believe the Sylvania 7963 is the better tube.
  
 It is currently going for around $15 to $20 on eBay, quite a bit more than the 6832, at $3 to $5. And for some, it may not be worth it. After all, the 6832 is a very good tube. On the other hand, I believe the 7963 is in the same league as a pair of C3g's or a Sylvania 6SN7W which typically go for around $70. And so to my mind, the 7963 is a steal for $20. But of course, YMMV.


----------



## gibosi

trolldragon said:


> The key is to have all your wires in a circular pattern............
> 
> It's a bit of a pain that whoever designed the tube didn't follow a standard dual triode pinout.


 
  
 Thanks for the tips. 
  
 I should confess that I tried this with my 6021 after having uninstalled it from my "easy and ugly" adapter. As the ends of the leads had been wrapped and soldered, I wasn't able to completely restraighten them, and of course, this made the very difficult task of guiding the leads into the pins even more difficult....
  
 I might try this again with clean and straight leads when I my 6N16B's arrive. However, these tubes have 9 leads, and I suspect that I will have to guide the leads for the shield and one of the cathodes into the same pin.... again, making a very difficult task just a little more difficult... Or I just might end up installing the 6N16B into a 9-pin socket saver....
  
 ~~~~~~~~
  
 All the American sub-miniature twin triodes have the same pinout. It is my understanding that the pinout was designed in this way to facilitate soldering the tube onto a circuit board, similar to an op amp. But of course, this makes it a pain to install them into the old standard 8-pin and 9-pin adapters.... 
  
 But it occurs to me that one could trim the leads a bit and easily insert them into a TO-99 op amp socket. And I have been thinking that it would be slick to have a TO-99 to 8-pin octal adapter, such that we could easily plug and unplug these sub-miniatures. But I haven't quite figured out how to make one....
  
 Cheers


----------



## Audio tumshie

Hi, I'm new to tubes and wondered what pair of tubes Mullard cv4014 would replace, rear or front?
 I just got my LD and I've no clue as to which are drivers or power. Are the large ones power and how do you tell what are power or driver in a sellers lists of tubes?
 Thanks in advance.


----------



## TrollDragon

Yes indeed a semiconductor socket would be perfect, I was going to mount the 6832 in a machined pin DIP 8 socket as I have quite a few from opamp rolling.

This is one from eBay and how it would look, without the bent pin... 


It would be easier to solder wires to a second machine pin socket and epoxy it to the top of your octal socket / plug adapter as you can work from both ends to get the wires aligned.

Then you solder a DIP socket to your new tubes in whichever configuration you need and just plug it in.

This would work perfectly with machine pin TO-99 sockets as well since they have a tube socket type look to them! I'll have to get me some of these from my local RAE electronics distributor.

Pure Genius gibosi, pure genius!


----------



## mordy

Hi At,
  
 I assume that you have a Little Dot MKIII or IV. These amps have four tubes. The front tubes are the driver tubes, and the rear ones the power tubes.
  
 Which model do you have, and what are the other two tubes?
  
 The CV4014 is a pentode of the EF91 family. Go to page 77 of this blog and look at the chart there that lists compatible tubes. In addition, download and print out the manual for your amplifier. It is a short read, but very informative. The link is at the bottom of this page:
  
 http://www.littledot.net/forum/viewtopic.php?f=9&t=815&sid=d19a88fc5a2b44c2f0c87179030bd08d#p3199


----------



## mordy

If you have a breadboard adapter with a 9pin socket, it is easy to build a solderless adapter for the 6832 tube. You need a 9pin socket extender, some 1mm heat shrink tubing, and 0.8mm/18gauge copper wire.
  
 Cut the copper wire into small pieces and strip off 1/4" at the end. This becomes a push pin to keep the flexible lead wedged in the socket. Before mounting the leads in the socket extender, thread on appropriate lengths of shrink wrap to insulate the leads from each other.
  
 The metal to metal makes for a very good contact area - let's face it; all tube sockets work on this principle.
  




  
  
 The heat shrink tubing is not shown in this picture:




  
 With this set up you can just pull out the whole assembly with the extender like a regular tube to swap for another tube.


----------



## i luvmusic 2

What about something like this( Rocket Launch Pad
	

	
	
		
		

		
		
	


	




 )upside down octal socket with terminal block i call it one adapter fits all 8 pin miniature.


----------



## i luvmusic 2

Hi Mordy,
    Have you tried using the 6832 as a Power Tubes?Thank You!


----------



## TrollDragon

That is a great adapter as well ILM2!

It just needs a big Red Star and CCCP to set it off, and a Soviet tube of course.


----------



## i luvmusic 2

trolldragon said:


> That is a great adapter as well ILM2!
> 
> It just needs a big Red Star and CCCP to set it off, and a Soviet tube of course.


 
 Thanks! And where can i get some of those LOL


----------



## mordy

Hi IL2,
  
 Yes indeed - I tried using an all 6832 set up.
  




  
 I(image missing)


----------



## Audio tumshie

[COLOR=FF00AA]"Hi At,
I assume that you have a Little Dot MKIII or IV. These amps have four tubes. The front tubes are the driver tubes, and the rear ones the power tubes.
Which model do you have, and what are the other two tubes?"[/COLOR]

Sorry mordy, I forgot to say my LD is MKII. All the tubes are stock so far since it's new.I was checking my options because I found a Brittish web site for tubes or valves as I call them.


----------



## Rossliew

Guys, sorry to back track here...anyone can recommend an affordable 6SN7 tube that is warm and sweet sounding (traditional tubey sound)? Am looking for some to use in my Mk 3 for vocal tunes..after aggressive music all this while, need some slow down and warm, syrupy sweet signatures : ) Thanks in advance! Will be pairing with EF95 type driver tubes if this is of help..


----------



## sgbwill2

Supposedly the RCA red base 5692 have the sweetest sound of all the 6sn7's. Speaking of 6sn7's mine are causing major distortion again at higher volumes which I am unsure why =/ hopefully the 6f8g tung-sol's or NU 7n7's fix this problem as I will be using different adapters and I think that is what is causing the problems with my 6sn7's.


----------



## Rossliew

sgbwill2 said:


> Supposedly the RCA red base 5692 have the sweetest sound of all the 6sn7's. Speaking of 6sn7's mine are causing major distortion again at higher volumes which I am unsure why =/ hopefully the 6f8g tung-sol's or NU 7n7's fix this problem as I will be using different adapters and I think that is what is causing the problems with my 6sn7's.


 
 Are the RCAs expensive? For your other tubes, are you using an external PS as well?


----------



## sgbwill2

Yes unfortunately they are very expensive. For the 6sn7's no I am not using external power supplies as there is no need as they are only have a 0.6 draw up.


----------



## Rossliew

sgbwill2 said:


> Yes unfortunately they are very expensive. For the 6sn7's no I am not using external power supplies as there is no need as they are only have a 0.6 draw up.


 
 Sorry I meant the 6f8g / 7n7..


----------



## gibosi

rossliew said:


> Guys, sorry to back track here...anyone can recommend an affordable 6SN7 tube that is warm and sweet sounding (traditional tubey sound)? Am looking for some to use in my Mk 3 for vocal tunes..after aggressive music all this while, need some slow down and warm, syrupy sweet signatures : ) Thanks in advance! Will be pairing with EF95 type driver tubes if this is of help..


 
  
 It appears that you will be using 6SN7's as power tubes, so an external heater power supply is not necessary. I don't have the RCA red base 5692, so can't comment on it personally. And given that they don't get a whole lot of love in the 6SN7 forum and they are not exactly cheap, they are not even on my radar screen. lol
  
 But for sure, RCA tubes in general tend to be warm and sweet, so I would start cheap. Mordy has reported very favorably on the sound of his 6SN7GTB's and they are very affordable. I have a couple pairs of 1940's gray glass 6SN7GT / VT-231 and they are wonderful tubes. The National Union's, both gray and black glass versions, are also quite sweet. And another wonderful tube, but often a bit more pricey, is the 1940's Ken-Rad 6SN7GT / VT-231. Any of these would be well worth trying, IMO.


----------



## gibosi

rossliew said:


> Sorry I meant the 6f8g / 7n7..


 
  
 Like the 6SN7, these tubes draw .6A, However, each requires a different adapter.


----------



## Rossliew

gibosi said:


> It appears that you will be using 6SN7's as power tubes, so an external heater power supply is not necessary. I don't have the RCA red base 5692, so can't comment on it personally. And given that they don't get a whole lot of love in the 6SN7 forum and they are not exactly cheap, they are not even on my radar screen. lol
> 
> But for sure, RCA tubes in general tend to be warm and sweet, so I would start cheap. Mordy has reported very favorably on the sound of his 6SN7GTB's and they are very affordable. I have a couple pairs of 1940's gray glass 6SN7GT / VT-231 and they are wonderful tubes. The National Union's, both gray and black glass versions, are also quite sweet. And another wonderful tube, but often a bit more pricey, is the 1940's Ken-Rad 6SN7GT / VT-231. Any of these would be well worth trying, IMO.


 
 Thank you, thank you! Yes, the 5692 cost a bomb on eBay and I don't believe its worthwhile at that price. I shall check out the tubes you mentioned then.


----------



## Rossliew

sgbwill2 said:


> Supposedly the RCA red base 5692 have the sweetest sound of all the 6sn7's. Speaking of 6sn7's mine are causing major distortion again at higher volumes which I am unsure why =/ hopefully the 6f8g tung-sol's or NU 7n7's fix this problem as I will be using different adapters and I think that is what is causing the problems with my 6sn7's.


 
 Can you share pictures of your 6f8g and 7n7 adaptors for the Little Dot? thanks


----------



## sgbwill2

When I receive them sure. I bought them off ebay though and the listings are here:
  
 http://www.ebay.co.uk/itm/1pc-6F8G-TO-6CG7-6FQ7-tube-adapter-CNC-Copper-body-/191197575305?pt=US_Home_Audio_Amplifiers_Preamps&hash=item2c84437889
  
 http://www.ebay.co.uk/itm/1pc-7N7-7F7-TO-12AU7-12AX7-tube-adapter-for-you-amp-6-3V-Heat-/201102573014?pt=UK_Sound_Vision_Amplifier_Parts&hash=item2ed2a5bdd6


----------



## Rossliew

Will these do? I already have the 6SN7 Adaptor so i figure I can just add these 6f8g adaptors on top..
  
 http://www.ebay.com/itm/300980566435?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT
  
 The following is what I have for using 6SN7 tubes :
  
 http://www.ebay.com/itm/2-x-convert-tube-socket-6CG7-to-6SN7/221065459067?_trksid=p3984.c100023.m2049&_trkparms=aid%3D333008%26algo%3DRIC.MBE%26ao%3D1%26asc%3D22943%26meid%3D7824974462340279553%26pid%3D100023%26prg%3D9893%26rkt%3D4%26
  
  
 So, can i just get the "6f8g to 6sn7" adaptor and plug it on top of the "6cg7 to 6sn7" adaptor?


----------



## Nic Rhodes

The 5692 red is a nice tube but certainly not the best, the problem with them is the price after the Sound Practice article. We are blessed with many excellent 6SN7s however a few are now getting pricey (Tung Sol, the Swedish one, early Sylvania Ws, the red 5692s) however there are still some bargains to be had for not silly money, early Ken Rads, Natuional Unions, CBS Hytron 5692, most ww11 ones (vt 231). I am a big fan of the 50 and 60s 6SN7WGTs and european examples. Still loads of NOS goodies out their unlike some tubes and I haven't even got around to checking out the Russian ones!.


----------



## sgbwill2

rossliew said:


> Will these do? I already have the 6SN7 Adaptor so i figure I can just add these 6f8g adaptors on top..
> 
> http://www.ebay.com/itm/300980566435?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT
> 
> ...


 
 Yes they should work. I was contemplating getting them myself though seen as I have removed the rings I can plug them straight in with a 9 pin. Heres another cheaper alternative: http://www.ebay.com/itm/1pc-6F8G-6C8G-TO-6SN7-6SL7-TUBE-ADAPTER-/190991571450?pt=Vintage_Electronics_R2&hash=item2c77fc19fa


----------



## Rossliew

sgbwill2 said:


> Yes they should work. I was contemplating getting them myself though seen as I have removed the rings I can plug them straight in with a 9 pin. Heres another cheaper alternative: http://www.ebay.com/itm/1pc-6F8G-6C8G-TO-6SN7-6SL7-TUBE-ADAPTER-/190991571450?pt=Vintage_Electronics_R2&hash=item2c77fc19fa


 
 Much cheaper! Thanks!


----------



## Rossliew

nic rhodes said:


> The 5692 red is a nice tube but certainly not the best, the problem with them is the price after the Sound Practice article. We are blessed with many excellent 6SN7s however a few are now getting pricey (Tung Sol, the Swedish one, early Sylvania Ws, the red 5692s) however there are still some bargains to be had for not silly money, early Ken Rads, Natuional Unions, CBS Hytron 5692, most ww11 ones (vt 231). I am a big fan of the 50 and 60s 6SN7WGTs and european examples. Still loads of NOS goodies out their unlike some tubes and I haven't even got around to checking out the Russian ones!.


 
 Am actually listening to a pair of Russian generic 6SN7 tubes and they sound mighty good. Strong sounding and i think slightly higher gain than the Ken Rad VT231s.


----------



## mordy

Hi Rossliew,
  
 From what I read the red base RCA were hyped up by a retailer that had a lot of them, and as Gibosi mentions, a lot of people don't think that they are special at all. Since we do not have any preconceived ideas on this forum what is the best sound, we can perhaps look or listen more objectively.
  
 I ordered several lots of 6SN7 tubes when the price was right in order to become familiar with them. Any 60's Sylvania 6SN7GTB sounds very good, and also RCA 6SN7GT tubes with a little horizontal heater wire on top of the top mica. These tubes can be found for $5 or less with a little patience. In addition, these tubes are long lived - 10,000 hours, and so far I have not bought any that did not work. They are very simple to use - just plug and play.
  
 Tried a couple of inexpensive Russian tubes, but in the long run I find that I am always coming back to US made tubes as better sounding, at least to me.


----------



## Nic Rhodes

Although there certainly had been interest before on the special red tubes (especially from Asia and MFA) but I remember the hype going into over drive with the Joe Roberts? article on red bank tubes for issue 3 of Sound Practices magazine (1993 I think). Prices went silly after that with people thinking they were the best made tubes available, little did they know about Bendix! Nice tube, wrong price.


----------



## Oskari

Oh, it's a great tube...
  
 If you need it for your artillery computer.


----------



## mordy

The 6832 "insures optimum performance in guided missiles" according to the Raytheon manual.


----------



## Oskari

Hej, mordy! These pages explain why the Swedish version of the 5692 exists:
  

http://www.veteranklubbenalfa.se/veteran/09q2/090611.htm
http://www.sm7ucz.se/Kanongrej/Kanongrej.htm
  
 The rest of you might need:
  

https://translate.google.com


----------



## Rossliew

mordy said:


> Hi Rossliew,
> 
> From what I read the red base RCA were hyped up by a retailer that had a lot of them, and as Gibosi mentions, a lot of people don't think that they are special at all. Since we do not have any preconceived ideas on this forum what is the best sound, we can perhaps look or listen more objectively.
> 
> ...


 
  
 HI Mordy,
  
 I only have 2 pairs of 6SN7s and so far, they are serving me well. I would like to explore other tube types like the 6f8g (they look good!) and C3gs and see how they fare. Tempted with the 6SL7s but afraid of the complexity involved in building the adaptor and external PSU. 
  
 Having said that, I may just buy another couple of pairs of 6SN7s just for experimentation : )


----------



## mordy

The 6SL7 tubes are just plug and play exactly like the 6SN7 and don't need any external PS. IMHO they sound a little lightweight in the bass compared to the 6SN7 tubes when used as power tubes, but still very nice sounding - a light and elegant sound if you will...


----------



## mordy

Hi Oskari,
  
 Thanks for the interesting Swedish vacuum tube history. Wonder if the rubber mounted sockets would make a difference in audiophile applications - sometimes I play recordings with cannon shots....


----------



## Rossliew

mordy said:


> The 6SL7 tubes are just plug and play exactly like the 6SN7 and don't need any external PS. IMHO they sound a little lightweight in the bass compared to the 6SN7 tubes when used as power tubes, but still very nice sounding - a light and elegant sound if you will...


 
 Hmm...this is interesting. Is the adaptor the same as the one used with 6SN7 tubes?
  
 On another note, after some experimentation, I found the 6SN7+6HM5 combo to be slightly veiled with my HD600. Edges were softer leading to an overall smothered kinda sound.


----------



## Rossliew

These sound like a good deal...plug and play?
  
 http://www.ebay.com/itm/Lot-of-4-6N9S-6H9C-6SL7-1579-Russian-Double-Triode-Tubes-NOS-NIB-Tested-/141324377412?pt=Vintage_Electronics_R2&hash=item20e796dd44


----------



## TrollDragon

rossliew said:


> These sound like a good deal...plug and play?
> 
> http://www.ebay.com/itm/Lot-of-4-6N9S-6H9C-6SL7-1579-Russian-Double-Triode-Tubes-NOS-NIB-Tested-/141324377412?pt=Vintage_Electronics_R2&hash=item20e796dd44


 
 I think we all have a quad of 6H9C's here, they are a decent tube for the price, 6SL7 compatible so no external supply required.


----------



## Rossliew

trolldragon said:


> I think we all have a quad of 6H9C's here, they are a decent tube for the price, 6SL7 compatible so no external supply required.


 
 Thanks, TD.
  
 So, can I confirm I can use these tubes with the present 6SN7 adaptors?


----------



## TrollDragon

rossliew said:


> Thanks, TD.
> 
> So, can I confirm I can use these tubes with the present 6SN7 adaptors?


 
 They will work perfectly in your 6SN7 adapters but the tubes have a gain of 70 vs 20 and much higher plate resistance, so I don't know how they will fare as power tubes. I have used a single tube as a driver before with good results.
 .


----------



## Rossliew

trolldragon said:


> They will work perfectly in your 6SN7 adapters but the tubes have a gain of 70 vs 20 and much higher plate resistance, so I don't know how they will fare as power tubes. I have used a single tube as a driver before with good results.
> .


 
 Hmm....then using 2 tubes as power tubes may blow my LD3 to smithereens?


----------



## TrollDragon

I dont think that will happen, others have tried them as power tubes before if you search back through the thread.


----------



## Rossliew

trolldragon said:


> I dont think that will happen, others have tried them as power tubes before if you search back through the thread.


 
 Noted with thanks


----------



## rosgr63

mordy said:


> The 6SL7 tubes are just plug and play exactly like the 6SN7 and don't need any external PS. IMHO they sound a little lightweight in the bass compared to the 6SN7 tubes when used as power tubes, but still very nice sounding - a light and elegant sound if you will...


 
  
 That's provided the plate voltage is less than 250V.
  
 Here are some 33S30 from my collection.


----------



## MKTRV6

What a great review and it's been very helpful to me!
  
 I liked the stock GE tubes on my LD3, but was hoping for a bit more bass, especially for the DT-880's, so I sprung for the Voshkod 6ZH1P-EV's, which indeed had significantly more bass, but also significantly more in the high frequency range.  These were the cat's meow for the HD-595's, but the mid-range when using the DT-880's was noticeably weak, especially compared to the GE stock tubes.
  
 Decided to try the Mullard NOS M8100's and holy cow, what a difference!  Now the DT-880's sound extremely good with improved bass, sweet midrange and enough high frequency response to make a really nice balance.  Not so good for the HD-595's by comparison which now sound muddy and don't have enough top end sparkle.
  
 As a result, I'm using a SS amp for the Sennheisers and the LD3 for the DT-880's.  I haven't ventured into the TOTL phones yet as that's still a bit pricey for me, but I have to agree with those that have said headphone technology is still immature in development.  The HUGE differences between headphones and amps is remarkable.  Still loving it!
  
  
 Mark


----------



## Rossliew

rosgr63 said:


> That's provided the plate voltage is less than 250V.
> 
> Here are some 33S30 from my collection.




Sorry, what do you mean by plate voltage? Is this affected by output voltages? Here in Malaysia, it's 240v.


----------



## mordy

I have used 6SL7 tubes as power tubes without any problems. Even used one as a driver together with the power tubes. The sound is very pleasant; quick and detailed but a little lightweight.
  
 At this time I am using a  1954 12SL7 GE (12V version of 6SL7) and a RCA 6AS7G with good results. Since the SL tube plays louder than the AS tube I have to compensate slightly with the balance control.
  

 Why this uneven set up? I did something stupid, totally my fault - can't blame anything else, and shorted out one of my 5A voltage regulators. Explosion, white acrid smoke - yuck!!!!  After shutting everything off and after the smoke cleared (exaggeration, but it sure smelled) I saw that the microchip had burnt up and shattered. Had to use my old voltage regulator that only can handle 2A which is just fine for a 12V/0.3A tube.
  
 Aerial view of destroyed area:
  

  
 Such is the life of a tube roller - full of excitement....
  
 Here is a picture of the latest scientific tool in our arsenal - a thermometer with a probe. Through an intricate mechanism it has been attached to my equipment stand. The tip is resting on the transformer housing. Without the fan on, the housing reaches over 90F; the fan lowers the temperature 10 degrees to around 80F. The tie strap serves to hold the fan in place - one of three.
  

  




  
 When the price is right I am going to try to purchase a 15A voltage regulator - should be enough for two 2.5A 6AS7 tubes. My A/V engineer friend told me that the current draw could triple on start-up.
  
 Happy tube rolling!


----------



## mordy

Hi I luvmusic 2,
  
_Have you tried using the 6832 as a Power Tubes?Thank You!_
  
 Yes, I tried it. Here is the proof:
  




  
 The sound was quite good, but ultimately I found that the bass lacked power and did not have enough slam and impact. For this we need the 6080/6AS7 tubes with the concomitant voltage regulators and power supplies.


----------



## rosgr63

rossliew said:


> Sorry, what do you mean by plate voltage? Is this affected by output voltages? Here in Malaysia, it's 240v.


 
  
 The maximum Plate Voltage 6SL7 can handle is 250V.
 6SN7 can handle 300V and 6SN7GTB 450V.
  
 If an amp is designed to run the 6SN7 above 250V, you cannot replace them with 6SL7.
  
 All this has nothing to do with your mains voltage but the way the amp is designed.


----------



## gibosi

My 1+ runs 6SN7's and 6SL7's with a plate voltage of around 100V, and I believe the II, III and IV are similar in this regard. So as Mordy said, in our amps, the 6SL7, like the 6SN7, used as power tubes, are plug and play. However, as Mordy pointed out earlier, power tubes are all about power. The 6SL7 simply does not move enough current to provide a satisfying level of bass slam and propulsive rhythm when used as a power tube.


----------



## Rossliew

Thanks for the clarification @rosgr63 and @gibosi !
  
 I may try a pair of 6SL7 just for the kicks.. : )


----------



## i luvmusic 2

mordy said:


> Hi I luvmusic 2,
> 
> _Have you tried using the 6832 as a Power Tubes?Thank You!_
> 
> ...


 
 THANK YOU! And sorry about your REGULATOR!


----------



## i luvmusic 2

I promised my self no more 6/12SN7's tubes for me but i was tempted by these 2 SYLVANIA  8SN7 GTB for $15 ,2 12SN7  SYLVANIA and PHILCO for $8, 6 12SN7 T-S,GE,CBS Hytron,SYLVANIA and RCA for $29.Is these a good deal? THANKS!


----------



## gibosi

Received some 6N16B-VR sub-miniatures today. These are the Russian equivalent to the American 6021. Moreover, the VR indicates that these are uber-premium. The major physical difference I see is these have 9 leads, whereas the 6021 and regular 6N16B have 8. And further, the "pin-out" is different than the American sub-miniatures. I intend to mount these into a 9-pin socket-saver using Mordy's ingenious 18-gauge pins.
  
 Curiously, there are two very similar numbers, one printed below the tube number, 9109, and the other above, 9103. Perhaps date related? Or perhaps not?
  

  
 I believe the circle-M symbol indicates that these were manufactured in the Melz factory located in Moscow. 
  

  
 The etched characters appear to be OTK - 73, which leads me to to think that the year of manufacture is 1973.
  

  
 And an etched rhombus with the number 14.
  

  
 Anyway, hope to get his little guy mounted and start burning it in soon.


----------



## mordy

Hi Gibosi,
  
 Congrats om the Russian sub miniature tubes - curious to know how they sound. Seems that Meltz is a high quality factory, but I don't really know the differences between the Russian factories.
  
 Regarding the OTK designation, my impression is that this is simply a quality control number, and the number is the number of the inspector. Usually you find lower numbers in the single digits. In this case OTK 73 would simply mean "inspected by quality control inspector #73" and I don't think that it has a bearing on the year it was manufactured.
  
 I think I saw somewhere that the number inside the rhombus indicates a certain quality level, similar to the US JAN or W designations for military use.
  
 Maybe I am wrong on this, but this is as far as I got when trying to decipher this information.
  
 Oskari - maybe you want to weigh in on this?


----------



## Oskari

O.K. Yep, that's MELZ. I agree that OTK is a quality control mark. I've read something about quality levels, too, but I'm not sure about them. Those 910X strings match the YYMM date format. But: Why two dates? Manufacturing date and acceptance date?


----------



## gibosi

On the eBay listing for these, the pictures show the date with the same format as is commonly seen on the 6N23P, that is "VIII - 80". Maybe into the 1990's the format changed to YYMM? But if so, the two different dates is a bit of a conundrom...
  
 http://www.ebay.com/itm/181254560270?


----------



## mordy

Here is a short history of the Melz factory. Seems tubes were produced from 1942 until the 80's(?):
  




Moscow Electric Plant "MELZ" is the oldest in Russia for production of electronic devices. History of the plant began with a workshop for making light bulbs in 1906. Soon workshop has grown to the size of the factory. She launched by 300,000 bulbs per year.
In 1921 was founded the Moscow Association factories tubes . In 1926, automobile designs have been developed and powerful gas-filled tubes . Vacuum tubes produce steel from domestic flint glass. Factories moved with plant production system for streaming. Import radio tubes to Russia stopped. Moscow Electric Plant became the first and largest in the country now - plant. In 1929, all electron tubes factories were placed under the leadership of " the Moscow Electric Plant".
In 1938 the plant was divided into several independent companies . By this time, the emergence of the name of the plant MELZ.
During the Second World War, the factory worked around the clock and releasing the necessary radio tubes . In 1942, the plant began production of tubes . In the same year from besieged Leningrad factory "Svetlana", arrived in Moscow large group of specialists . They, along with specialists MELZ begun to establish pilot production of special generator tubes designed for radar transmitters. In the 60s to establish production of color picture tubes.
In the mid-70s at the plant was organized by central laboratory (CPL), which dealt with the optimization of manufacturing processes electronic devices. In the 80s there was a decline of the plant. Many of its territory emptied. It was only in the mid-90s production began to recover.


 In the past few years, special attention is paid to MELZ creation and development of the production of energy-saving light sources: high pressure sodium lamps and compact fluorescent lamps. Just the company started production of glass products for the food industry. But the main activity is the production of electron-optical converters (EOP) 2 and 2 + generations, as well as night vision binoculars with image making false color.
 
The architecture of the Melz building in Moscow was obviously inspired by tubes:
 
 





  
 MELZ is an acronym for Moscow Electric Tube Plant  (Moskovsky Elektrolampovy Zavod).


----------



## Oskari

gibosi said:


> On the eBay listing for these, the pictures show the date with the same format as is commonly seen on the 6N23P, that is "VIII - 80". Maybe into the 1990's the format changed to YYMM? But if so, the two different dates is a bit of a conundrom...
> 
> http://www.ebay.com/itm/181254560270?


 
  
 Even those have two dates!
  
 The format did change at some point. When exactly, and whether this is true for all manufacturers, I don't know.


----------



## Nic Rhodes

I think the 9103 date relates to march 91 as year of manufacture. The 73 number is just tied up with a person inspecting in this case at the Melz factory.


----------



## TrollDragon

A lot of the sub miniatures only have a maximum plate voltage of 100V unlike the 7963 which has a 165V plate maximum.

Maybe gibosi you can take some readings of the plate voltages on the various sub miniatures before everyone gets too carried away with them. I'd hate to see the tubes arc over in someone's amplifier.


----------



## TrollDragon

I just measured the 6832 in my MK IV and I am getting 105V &108V on the plates. I am not sure as to how far overvoltage these will run, but from what I have read, a lot of tubes will tolerate higher plate voltage as long as the current is lower.


----------



## gibosi

The absolute maximum plate voltage for the 6021 is 165 volts, and for the Russian 6N16B, 200 volts, so no worries.


----------



## lithium1085

Hi Mordy, you had uploaded a picture of a 1945 raytheon 6AK5 some time ago. Would it be possible to upload this picture again since the link appears to be broken now? Thanks for your help.


----------



## mordy

Here is a picture of this tube:
  
 (image missing)
  
  
  
  
 I still have one such tube left - PM me if interested


----------



## mordy

Hi lithium 1085,
  
 Here is a picture of this tube:
  

  
 I have one tube left - please PM me if you are interested.


----------



## gibosi

Mounted the 6N16B-VR into an octal base last night. I tried to install it into 9-pin socket saver with 18-gauge pins, but gave up. The 18-gauge pins simply wouldn't hold the leads securely enough and I couldn't get all 9 inserted, without some pulling out. Perhaps a higher quality socket-saver would work better.  And perhaps 9 leads instead of 8 plus too much twisting and crossing to get everything lined up correctly. Whatever, after fiddling with it for over an hour, I went back to my "easy and ugly" octal mount. In the event others decide to mount a 6N16B-VR into an octal base, I should point out that it is necessary to tie leads 5 (shield) and 6 (cathode) together.


----------



## mordy

Hi Gibosi,
  
 It seems to me that the octal socket pins are thicker than the 9 socket pins. The push pins work very well with a 9pin socket extender providing a good tight fit.
  




  
 Here is a link to the 9pin socket extenders:




  
 http://www.ebay.com/itm/4pc-9PIN-Bakelite-vaccum-TUBE-SOCKET-SAVER-base-FOR-12AX7-12AU7-ECC82-ECC83-amps-/161352940119?pt=Vintage_Electronics_R2&hash=item2591627a57
  
 Following the diagram you provided, it was no too difficult to insert each lead in it's place with a small needle nose pliers. It is a good idea to insulate each lead with shrink wrap to avoid contact, but if you are careful, it can be assembled without the shrink wrap.




  
 http://www.ebay.com/itm/100x-1-0mm-Diameter-Black-Heat-Shrinkable-Tube-Shrink-Tubing-50mm-length-2-1-/181285338463?pt=LH_DefaultDomain_0&hash=item2a3572bd5f
  
 By buying several 9pin extenders you can switch the sub miniature tubes just like you switch in and out regular tubes, and you do not have to disassemble the tube set up.


----------



## gibosi

Mordy
  
 I did try to use a *9-pin socket-saver* with 18 gauge pins. And again, the connections were not tight enough.
  
 That you have had good success suggests to me that not all 9-pin socket-savers are the same. I bought these thinking that gold was better. 
  
 http://www.ebay.com/itm/140892378813?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649
  
 But even though secured with 18-gauge pins, the leads slide in and out too easily.
  
 I did manage to mount a 7963 into one of these gold 9-pin socket-savers. Again, the leads were not as tight as I would like and I used electrical tape to keep everything in place. I planned to do the same thing with the 6N16B-VR, but never was able to get all the leads inserted without others sliding out.
  
 So people should buy the 9-pin socket-savers that Mordy bought. Not the ones I bought. lol


----------



## i luvmusic 2

You can used a sewing needle to tighten the socket pin hole.Gently push in the needle on the side of the socket pin hole to reduced the gap of the socket hole(mine is gold plated 9 pin saver the socket hole is slotted/split) I've done this before just watch your finger while doing this.


----------



## mordy

Hi Gibosi,
  
 And I thought that all 9pin socket extenders were the same....The ones I bought were the least expensive (4 for $6.59 incl shipping) but don't look to be high quality and are only rated for 200 uses (whatever that means).
  
 Anyhow, how does the 6N16B-VR sound compared to the Sylvania 7963 and the Raytheon 6832?
  
 Hi I luvmusic2,
  
 I have an extender adapter for octal tubes to 9pin that is too tight, and I have to push very hard to get the octal tube in all the way, and use even more force to pull it out. Do you have any advice how to make the adapter less tight fitting?


----------



## TrollDragon

Y'all need to build up one of these...


----------



## TrollDragon

Much gibosi pictures in the Ohio meet thread, we can now all put a face to a name.


----------



## gibosi

It occurs to me that gold plated sockets might be a bit more slippery, with a little less friction than non-plated sockets, and this might be a contributing factor. However, using a sewing needle to try to tighten the sockets sounds like a good idea.
  
 And TD, I couldn't get an 8-lead miniature threaded through an octal base! There was noway that I was going to try 9 leads compressed down to 8! lol 
  
 I have only listened this tube for a few minutes, shortly after putting it in the amp for the first time, but I think it sounds pretty good. But of course, it needs to cook in for a day or so......
  
 Cheers


----------



## MIKELAP

trolldragon said:


> Much gibosi pictures in the Ohio meet thread, we can now all put a face to a name.


 
 +1


----------



## i luvmusic 2

mordy said:


> Hi Gibosi,
> 
> And I thought that all 9pin socket extenders were the same....The ones I bought were the least expensive (4 for $6.59 incl shipping) but don't look to be high quality and are only rated for 200 uses (whatever that means).
> 
> ...


 
 I used a AWG 8 solid copper for my Rocket Launcher and it made my Octal socket loosed.
 Perhaps too loosed so maybe a AWG 10 0r 12 sollid copper and wiggle it until it start to loosen up just don't over do it it might get too loosed.That's what happen to mine.
  


trolldragon said:


> Y'all need to build up one of these...


 
    You should buy bunch of those miniature tubes and start putting them in your Octal base and sell them to us but then again i have my Rocket Launcher so i don't need one for now,Just don't put made in Chinada.


----------



## i luvmusic 2

gibosi said:


> It occurs to me that gold plated sockets might be a bit more slippery, with a little less friction than non-plated sockets, and this might be a contributing factor. However, using a sewing needle to try to tighten the sockets sounds like a good idea.
> 
> And TD, I couldn't get an 8-lead miniature threaded through an octal base! There was noway that I was going to try 9 leads compressed down to 8! lol
> 
> ...


 
 I've done the needle before  back when we used to used the Vector 7 pin test/saver  and IMO it's easier to widen the slot than making it tighter with the needle but it can be done watch those fingers tho.


----------



## mojorisin35

Shipped some tubes to a fellow canadian and I'm ashamed to say it cost me more than shipping to the US. I have had tubes shipped from across the sea at 2$ for the package and it cost me 13 to ship a few provinces over. Rant over...


----------



## TrollDragon

Welcome to the Canadian Postal Service!

$13 tracked and it still took a week to get there, wait till you want to send the same tracked package to the USA... $$$


----------



## MIKELAP

trolldragon said:


> Welcome to the Canadian Postal Service!
> 
> $13 tracked and it still took a week to get there, wait till you want to send the same tracked package to the USA... $$$


 
 I did when i sent my Denons to Lawton Audio for mods and if i remember correctly  it cost me at least $35.00 to Rhode Island .


----------



## TrollDragon

mikelap said:


> I did when i sent my Denons to Lawton Audio for mods and if i remember correctly  it cost me at least $35.00 to Rhode Island .


When I sent the Burson / Audeze onto the next guy in New York, the box was huge and it went by FedEx which only cost $35 as well (reimbursed by Burson) so if your sending stuff to the states it pays to take a look at the carriers. I don't want to think what the Post Office would have charged for that shipment, would have been at least double.


----------



## mordy

I had to send back a receiver for repair - 33 lbs. The US post office wanted around $29, UPS around $33 and FedEx around $20, using a commercial FedEx account. My son told me that I should not have insured it for $600, but just the minimum (he claims they never lose anything) which dropped the shipping to $13. Caveat emptor....
  
 Seems that if you can get hold of a commercial FedEx account for heavier items, their rate would be the least expensive (only speaking about US domestic shipping, but it seems this would apply to Canada as well.)
  
 I once had an experience that FedEx shipped overnight, but since I used the cheaper rates (FedEx ground) they held the package in the arriving terminal so that it took longer (!).


----------



## gibosi

While I have yet to try to compare the Russian 6N16B-VR to the 8632 and the 7963 sub-miniatures, with something like 20 hours on this tube, I can say that this is an exceptionally fine tube. It definitely blows the American 6021 away. With a crystal clear presentation and exceptionally good imaging, multiple layers of sound, and large stage, I really like this tube. And therefore, I encourage others to try it. 
  
 To help, I have put together the following translation table.
  
 First, how to figure out which lead is which on the Russian tube.... There is no "larger gap" between leads 1 and 9, as there is on the 8-lead American sub-miniatures. However, there is what looks like lead # 10 that has been cut off flush with the glass. You may need a magnifying glass to see it. With my old eyes and bifocals, I do. lol And simply use that stub as your reference point to count and number the leads.

 6N16B-VR                                   6DJ8/6CG7                   6SN7
 1 Cathode 1                                       3                            6
 2 Grid 1                                             2                            4
 3 Heater                                            4                            7
 4 Plate 1                                            1                            5
 5 Shield                                             9                            3 tie to lead 6 (cathode 2)
 6 Cathode 2                                       8                            3
 7 Grid 2                                             7                            1
 8 Heater                                            5                            8
 9 Plate 2                                            6                            2
  
 Some might notice that in the case of the 6DJ8, I have connected the triodes in reverse. That is, 6N16B-VR, triode #1 is connected to 6DJ8, triode #2, and vice versa. This was done to make sure that the 6N16B-VR shield and cathode #2 were routed to the 6DJ8 pins 8 and 9. For tubes with shields, it is necessary to tie the shield to the adjacent cathode. The other cathode will not work properly. And fortunately, the tube doesn't care which triodes you designate as #1 and #2.


----------



## mordy

Hi Gibosi,
  
 Thanks for your schematic. Just to clarify, I would hold the tube with the leads facing down and count anti clockwise with the #1 lead to the left of the stub?
  
 Waiting to hear from you about a comparison to the 6832 and 7963 before I pull the trigger.....


----------



## gibosi

mordy said:


> Thanks for your schematic. Just to clarify, I would hold the tube with the leads facing down and count anti clockwise with the #1 lead to the left of the stub?
> 
> Waiting to hear from you about a comparison to the 6832 and 7963 before I pull the trigger.....


 
  
 You do this the same way as you would with any other tube. So as always, hold the tube upside down, and begin counting clockwise, starting with the lead to the left of the stub. If the leads are facing down, it is the mirror image. So you would count counter-clockwise, starting with the lead to the right of the stub.


----------



## sgbwill2

Hello everyone, I'm back again  in the time since I last posted here I have thoroughly been enjoying my tung sol 6f8g's with my c3g;s and sennheiser 650's. Though the other day I decided to try my denon d5000's through the amp. So I plugged in my denon's and flicked the switches on the base of the LD to lower impedance mode, and all I was hearing was major distortion. I had this problem before with the 6sn7's and thought it may be that I had a faulty jack or wire in my denon's but I tried them from other sources and they sounded fine. So I tried some more lower impedance headphone with the LD and I'm getting the same distorted results. Does anyone else have this same problem with their lower impedance headphones? I didn't get this distortion out of my denon's with the stock tubes so I'm wondering if that the 6f8g's, 6sn7's and c3g's just really dislike lower impedance headphones. Could anyone shed any light on this and suggest any way I can fix this problem?
  
 Thanks


----------



## TrollDragon

Switches for lower impedance mode???

Do you mean the gain jumpers? If so put them back to where they were and try the amp again. OTL amps are really not designed for low Z cans and can have trouble with some...

Since you are running unorthodox tubes gain settings might play a major factor in operation.


----------



## sgbwill2

Thanks for your prompt reply. I have tried them with the gain in high and low positions and get the same results either way =/ though the low gain is slightly better but still unlistenable as the distortion is so bad. I guess I will just have to use my d5000s with my portable setup instead.


----------



## TrollDragon

You're most welcome.

I made an impedance matcher for when I want to run my 35 Ohm Ultrasone's from the LD. I get a bad hum in them, basically all I did was take a 1/4" plug and a 1/8" socket and wire up an adapter with a 150 ohm resistor in series with each channel. It removes the hum for me, not an ideal solution but doesn't harm anything either.

It might work for you as well and easy to wire up loosely to test.


----------



## sgbwill2

That may be the best bet. I dont fancy buying a completely new amp for my low impedance headphones . Thanks again.


----------



## i luvmusic 2

Or you can get a LD 1+.
	

	
	
		
		

		
			




 LD 1+ pair well with my AKG QXXX and i used most of the driver tube for MK III.


----------



## i luvmusic 2

And some tube may sound nice in MK III but not with 1+ or vice versa.


----------



## sgbwill2

I've spent so much over the last few months on tubes ,amplifiers and cables. Not sure I could justify spending even more on a new amplifier haha


----------



## i luvmusic 2

Same here but for me at least i'am done spending $  for my LD's but BH CRACK is coming soon so that is another story for me.


----------



## i luvmusic 2

You should follow Mordy's advice on buying tubes it works for me saved some $ set a budget per tube.


----------



## sgbwill2

Sounds like its going to be fun . My aim for the future (a far distant future) is to eventually save for the la figaro 339. Sound wise its suppose to be terrific. It looks extremely well made and internally looks very clean.


----------



## i luvmusic 2

Yup sure is a nice amp( la figaro 339)but for me i had a lot of fun making my own cables, adapters and chassis that is why i went with the CRACK and who knows maybe some day i will build my own tube amp.


----------



## sgbwill2

Far more ambitious than I am. good luck to you. Hopefully the assembly will all go well.


----------



## i luvmusic 2

Thanks! i think i need all the luck i can get.


----------



## TrollDragon

sgbwill2 said:


> That may be the best bet. I dont fancy buying a completely new amp for my low impedance headphones . Thanks again.


You are welcome, hopefully it works for you as well. That La Figaro 339 is one gorgeous looking amp inside for sure!


----------



## mordy

Need a little help:
  
 I am preparing a power supply for my coming 15A voltage regulator, and I wanted to use an old PS from a computer rated  +12V  14A,  -12V  0.8A
                                                                                                                                                                                       + 5V   25A,   -5VSB  2A
  
 I plugged it into the wall outlet, but I am not able to measure any voltage at any of the 7 different plugs. The power cord to the PS has 115V - tried another PS and still no reading.
  
 What am I doing wrong?


----------



## TrollDragon

You're missing the power good signal there's usually a thin green wire roughly the middle of the connector and what you have to do short that to a black to get the power supply to actually turn on.

I'd send you a link but I'm actually in the car at the moment so Google is your friend.


----------



## i luvmusic 2

What i did with mine is cut off all the connectors then separate all the wires by colours and connect green to any black wires and leaved a few yellow and black wires longer than the rest of the wires so i used those longer wires for the Regulator.All the wires that i don't need i cut them short then soldered all the yellow wires(12V)together and all the black wires on the other bundle.


----------



## mordy

The PS has a 20 pin connector. Can I just jump the green wire with the closest black wire there?
  
 There are another 6 connectors. Is it enough to just use one black and one yellow wire to connect the voltage regulator (from the longest lead), or do I have to bundle together all yellow and black wires? (eight black and 5 yellow)?


----------



## i luvmusic 2

You can use a jumper for the green to black but make sure it does not move or touch anything else for this i've used a jumbo paper clips.
 IMO you can use just 1 yellow and one black for the regulator that is how i hooked up mine before.I would cut 1 yellow and 1 black from the 20/24 pin connector then wrap the connector so the jumper is covered and it would not moved.


----------



## i luvmusic 2

Electrical tape maybe.


----------



## i luvmusic 2

The good  thing about  using a PS with a big fan on top of the case you can used it to cool the regulator.When ever i'am running a pair of 6AS7G tubes i usually put the regulator upside down on top of the PS fan and that cools the regulator.


----------



## mordy

Thanks for all the advice and tips - going to try to connect everything tomorrow. With two 6AS7 tubes, do the heat sinks get too hot to touch?


----------



## i luvmusic 2

It gets hot but not too hot to the touch,How i wish that those Heat sink on the Chinee regulators are bigger.I forgot to mention if you put the regulator on top of the case fan put on  something on the regulator to leaved a gap between  the regulator and the fan for this i've used those clear rubber bump on/bumper for cabinet doors.


----------



## hypnos1

Hey guys...
  
 A cheap laptop power supply/charger is sooo much easier lol! Not to mention neater...but then, y'all know I _love_ neat and tidy!
  
 Cheers.


----------



## mordy

I do have a cheap lap top power supply, but at 6.3V it puts out 8A if my calculations are correct.  It is rated 20V 2.5A. From what I have been told, a tube drawing 2.5A could use three times that current on startup, so ideally I would want something capable of 15A current draw.
  
 Now I have a new problem. When I connected the power supply as per instructions, everything works, and it puts out 11.3V, but as soon as I put the 6AS7 in the socket, the PS shuts off. It does reset itself, but every time I try, it shuts off again.
  
 What's the problem now? My PS is an older type, rated at 218W at 12V/14A, 5V/25A.


----------



## gibosi

I am using a Samsung laptop 19V 4.74A AC Adapter Charger:
  
 http://www.ebay.com/itm/151235154803?var=450272775764&ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649
  
 At 6.3V, it is capable of putting out a little over 14A, which should be more than adequate to run two 6AS7's. So if you are not able to get your desktop PS working, you might want to consider something like this.
  
 Edit: I have run a single 5998 in my LD1+ with a 5A regulator. If the 5998 required 3 times 2.5A, or 7.5A, at start-up, I suspect my regulator would have failed. Based on my experience, I believe that anything over 2 times the rated amperage is probably fine for 6AS7-type tubes: 2399, 421A, 5998, 6080, 7802, 7236....
  
 Edit2: The LD has a 1A heater circuit for drivers and 2.5A for powers. Two EF91's draw .6A, a bit more than half of LD"s 1A capacity. And two 6N30P draw around 1.7A, again more than half of the LD's 2.5A capacity.
  
 So I believe that designing your heater PS circuit to handle 3 times normal operating current is perhaps a good thing to do, it is not necessary.


----------



## i luvmusic 2

mordy said:


> I do have a cheap lap top power supply, but at 6.3V it puts out 8A if my calculations are correct.  It is rated 20V 2.5A. From what I have been told, a tube drawing 2.5A could use three times that current on startup, so ideally I would want something capable of 15A current draw.
> 
> Now I have a new problem. When I connected the power supply as per instructions, everything works, and it puts out 11.3V, but as soon as I put the 6AS7 in the socket, the PS shuts off. It does reset itself, but every time I try, it shuts off again.
> 
> What's the problem now? My PS is an older type, rated at 218W at 12V/14A, 5V/25A.


 
 You have a short somewhere.I never have that problem with my PS.


----------



## i luvmusic 2

Another thing to note about desktop PS D3LL PS have different colour coding.


----------



## mordy

Saw a YouTube video about using a PC PS and the guy said that you have to put in a resistor to make a dummy load. This is stuff that is beyond my abilities....
  
 It's not a Dell, so I know that I need the green and black wires.


----------



## i luvmusic 2

You can install one dummy load on 5V rail i used 20R 5W Ceramic resistor connected to RED(5V) and BLACK that's it very simple.


----------



## i luvmusic 2

You mentioned your PS is older model i believed older PS you need to install dummy load or it will be unstable sounds like your PS is unstable since it is resetting if there in so short.My PS is not that old so i can run it with out dummy load and it's fine so you should install a dummy load in your PS.


----------



## i luvmusic 2

Cut one RED and one BLACK from 20/24 PIN Connector and splice/solder the ceramic resistor on those pair of wires and you are in business just make sure that the resistor  does not touch anything else the resistor can get hot.


----------



## i luvmusic 2

hypnos1 said:


> Hey guys...
> 
> A cheap laptop power supply/charger is sooo much easier lol! Not to mention neater...but then, y'all know I _love_ neat and tidy!
> 
> Cheers.


 
 Iv'e got some PS for FREE....
	

	
	
		
		

		
			





 ZERO NADA $ for me


----------



## hypnos1

i luvmusic 2 said:


> Iv'e got some PS for FREE....
> 
> 
> 
> ...


 
  
 Hi ilm2.
  
 The best things in life are free?...I feel a song coming on, lol!
  
 I, too, try to be cheap - er, sorry, FRUGAL - but sometimes the hassle that can ensue has me reaching for the wallet, especially if we're not talking big bucks...
	

	
	
		
		

		
		
	


	



  
 mordy...as gibosi has found, I don't think we have to worry _too_ much about_ over-_ provision of power handling...my set-up has been on and off _numerous_ times, and still all is OK. Actually, as you guys have easy access to your pins/sockets, why don't you use the meter to see just what happens on start-up? On second thoughts, easier just to measure at the regulator, no? Just a thought....


----------



## i luvmusic 2

hypnos1 said:


> i luvmusic 2 said:
> 
> 
> > Iv'e got some PS for FREE....
> ...


 
 I agree with you the free stuff is good if you like screwing around with stuff like me.I feel bad that he is having trouble with his PS i do have a few desktop PS and some of them are the older model they do not work that well the out put voltage is lower compared to the newer model the older PS are unstable.


----------



## mordy

Success!
  
 Decided to use my new back up spare PS for my PC - a Thermaltake TR2 430 which is (you guessed it) a 430W PS. Can't decide what is worse, the LD MKIII not working or the PC not working - in any case I had to preserve the PS just in case, so no cutting.
  
 Found the right size wires to push into the right plugs, hooked everything up, and voila! Everything works just fine!
  
 There is a difference: The bass got considerable stronger and better defined compared to the old laptop PS so there must be something to the power output of different power supplies. Many of the high end audio  manufacturers are selling upgraded power supplies for their products.
  
 The other difference is that at the indicated 6.3 volts at the tube pins the voltage regulator reads 6.6V instead of 7V with the previous PS.
  
 This PS has dual fans (front and back) and seems a tad quieter as far as hum goes, but there is a whine at very high volume settings which I normally don't use. Have to figure out how to eliminate it.
  
 Esthetically, you could probable say that my configuration changed from spider web to snake pit - don't know why the braiding of all the wires looks like snake skin color.
  
 Again, I want to thank everybody who helped me in figuring out how to use the computer PC - thanks!


----------



## i luvmusic 2

Good for you Mordy
	

	
	
		
		

		
		
	


	




 as i said before the output varries from PS to PS newer power PS works better without any MOD(dummy load).
 My Desktop PS with the 12A regulator to get 6.3V on the tube pin i need to set the regulator at 6.39V if i'am using the laptop PS(19V-8A) the regulator is set to 6 to 7V to get 6.3V on tube pin.


----------



## i luvmusic 2

What do you guys do with your none working tubes?


----------



## TrollDragon

Garbage, or cut the bottom off of them to make adapters. 

Unhealthy schiit inside them, so don't playing with the bits and licking your fingers...


----------



## i luvmusic 2

Too late i just did...
	

	
	
		
		

		
		
	


	



 Mine are not garbage yet see.

  

 Sorry i don't mean to be childish i was just bored packing all my stuff to send back home my work here is done time to go back home(CANADA).I put a red LED inside the tube.


----------



## gibosi

mordy said:


> Decided to use my new back up spare PS for my PC - a Thermaltake TR2 430 .........................
> 
> There is a difference: The bass got considerable stronger and better defined compared to the old laptop PS so there must be something to the power output of different power supplies. Many of the high end audio  manufacturers are selling upgraded power supplies for their products.


 
  
 Frankly, this surprises me.... The upgraded power supplies in high end gear are designed to actually run the amp itself, that is, provide clean DC power to the cathodes, grids and plates. They do not provide power to the heaters. Heater power supplies are typically separate and making them more powerful than necessary shouldn't make any difference.... ????


----------



## mordy

Surprised me too. At this stage I am running a sub mini 6832 as driver, a 12SL7GT as one power tube with a separate power supply, and the RCA 6AS7 with the 430W PC PS. My guess is that there is some kind of synergistic effect between the channels, even though they are supposed to be completely separate.
  
 Don't have any explanation, and maybe it doesn't make sense logically; I am only reporting what I am hearing. A new 500W PS can be bought on sale at Newegg for around $30 with rebates. Over the years I have saved a couple of PCs by installing new PS when the old one gave out, and I like to have a spare on hand.


----------



## TrollDragon

Well my take on the PS issue is that the heaters are probably getting a proper current now where they were underpowered before.

Driving the regulator from a 12V 4A supply will only ever give you 4A of output, dropping the voltage to 6 will not give you 8A of power... The regulator is converting the voltage, it still only has the rated supply amps to work with.

Which is why I have always recommended a 8A or higher supply for a 5A draw...

The easiest way to test this is to actually measure the current draw on the heaters, something I suggested with a diagram some 100 or more pages back... 

If you do use your meter to measure the current on the 6AS7's or any other tube for that matter, hook up your meter power up the tubes and take your reading, leaving a meter on the 10A current measurement too long will burn it out as it does get warm inside.

1. Set the meter for 10A scale and double check it.
2. Move your probes to the 10A connections double check them.
3. Connect the meter in series with the heater wires + or Red to the positive on your regulator, - or Black to the tube.
4. Power up the LD and observe the current draw as the tube heats up no more than 30 seconds.

If you get a brief reading after you turn on the amplifier then nothing, it is possible that the in rush current has popped the 10A fuse in your meter and you will need to replace it.

Expensive meters and Amprobe's are a different story but I don't think anyone has those except for "Mr. Fluke" who we havn't seen in a while...


----------



## i luvmusic 2

Anyone of you guys used this TEAC - UD-H01 DAC?Thanks!


----------



## gibosi

trolldragon said:


> Well my take on the PS issue is that the heaters are probably getting a proper current now where they were underpowered before.
> 
> Driving the regulator from a 12V 4A supply will only ever give you 4A of output, dropping the voltage to 6 will not give you 8A of power... The regulator is converting the voltage, it still only has the rated supply amps to work with.
> 
> Which is why I have always recommended a 8A or higher supply for a 5A draw...


 
  
 Boy am I surprised! I have always assumed that when using these regulators, it was the wattage that remained constant. And therefore, as we reduced the voltage, amperage would accordingly increase. And now I learn that the amperage can never increase! Well, I learn something new everyday! lol
  
 And so, as TD recommends, if someone intends to run two 6AS7's, it is necessary to use a power supply that can provide significantly more than 5A. The 19V 4.74A AC Adapter / Charger I recommended above is not suitable....
  
 Edit: And I should add... If you are running 6SN7's as drivers, check your power supply. For best results, it should be rated at 1A or higher.


----------



## TrollDragon

All this power supply talk... As I go to turn on my computer tonight, the LEDs light then go out. Pull the power cord, wait 10 seconds and try again, same deal lights go on then out.

 Take it all apart, yank the supply out and down to the workshop I go to find the blown capacitor on the board. A 3300uF @ 10V on the 12V crowbar side was all puffed and the electrolyte was cooked and oozing out of it.

 Of course no one has an exact match in the parts bin so I swapped the one from the 5V side and put a 2200uF @ 16V in its place, all up and running again. 
	

	
	
		
		

		
		
	


	




 Old Enermax's can take a beating for sure.


----------



## gibosi

Yesterday took some time to compare three sub-miniatures, Raytheon 6832, Melz 6N16B-VR and Sylvania 7963. First, I should say that all these tubes are exceptional. Moreover, they are more similar than different. And the differences that exist are very subtle. So while I try to accentuate these differences below, in reality, they are quite small.
  
 As before, I found the 6832 to be the least 3-D of the bunch. The stage is relatively flat. Imaging and layering is less precise, and there is a little less clarity. In complex passages, it was a little harder to separate each strand. That said, the tone is right, vocals have good body and warmth, it is a very nice tube, all in all.
  
 At times, the 6N16B-VR can be breathtaking. Exquisite clarity and an almost magical 3-D space. There is a sense of immersion, being surrounded by the music, rather than the stage being somewhere in front of you. But... the vocals are a bit thin, and on some recordings, even a bit reedy. On most recordings, this is a supremely enjoyable tube, but once in awhile, I found the vocals to be a little grating. (I should say this is with Senns 700 and an LD 1+ with MUSES02 opamp.)
  
 The best of the four sub-miniatures in my possession (including the Sylvania 6021) is the 7963. It has all the 3-D magic of the 6N16B-VR plus that warm, silky-smooth Sylvania mid-range. As cheap as these sub-miniatures are, I recommend all three. But if the choice is one, and only one, then the Sylvania 7963 is the way to go.


----------



## hypnos1

trolldragon said:


> Well my take on the PS issue is that the heaters are probably getting a proper current now where they were underpowered before.
> 
> Driving the regulator from a 12V 4A supply will only ever give you 4A of output, dropping the voltage to 6 will not give you 8A of power... The regulator is converting the voltage, it still only has the rated supply amps to work with.
> 
> ...


 
  
 Glad you cleared up that heater power supply anomaly, TD - must admit I too was somewhat perplexed as to mordy's finding, lol!


----------



## i luvmusic 2

This SUCKS! I just got home and my rig is not gonna be here until next week.


----------



## i luvmusic 2

Oh by the way this tube(None working Chatham 6080WB with Red LED inside)) i sold it for $15.


----------



## hypnos1

A word to those with the C3g as drivers...if you decide to go the 6AS7G route, with external heater power supply - which once again I _implore_ you to take, if you haven't already - make sure you seek out the *CHATHAM *JAN CAHG tube. If ever a driver and power tube were made for each other, these most certainly were, lol! Even after all this time now, I continue to be amazed each and every listening session no matter what genre of music thrown at them. I feel no necessity _whatsoever_ to blow hard-earned cash on the (over?) high-priced 5998/421A/A1834 family...but of course that's just my take on things. Suppose it's because the much more reasonably-priced Chathams have me in total awe...and luckily, they do seem to pop up now and then. My RCAs cannot compare, IMHO.


----------



## i luvmusic 2

hypnos1 said:


> A word to those with the C3g as drivers...if you decide to go the 6AS7G route, with external heater power supply - which once again I _implore_ you to take, if you haven't already - make sure you seek out the *CHATHAM *JAN CAHG tube. If ever a driver and power tube were made for each other, these most certainly were, lol! Even after all this time now, I continue to be amazed each and every listening session no matter what genre of music thrown at them. I feel no necessity _whatsoever_ to blow hard-earned cash on the (over?) high-priced 5998/421A/A1834 family...but of course that's just my take on things. Suppose it's because the much more reasonably-priced Chathams have me in total awe...and luckily, they do seem to pop up now and then. My RCAs cannot compare, IMHO.


 
 Do you have any good source for Chatham 6AS7G's?If so please share.THANKS!


----------



## Nic Rhodes

I wish he would ship to the UK but for for the US / Canada try
  
 http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=221485227989&ssPageName=ADME:B:SS:GB:1120
  
 a bit of a bargain for some I think


----------



## i luvmusic 2

THANK YOU ALL ! For the LINK i just contact the vendor.I need 4 pcs. and i have 3 on it's way from Vacuum tubes(bought all chatham they have) .net sometimes they can be over price but these ones i'am grabbing some.Again Thank You!


----------



## hypnos1

nic rhodes said:


> I wish he would ship to the UK but for for the US / Canada try
> 
> http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=221485227989&ssPageName=ADME:B:SS:GB:1120
> 
> a bit of a bargain for some I think


 
  
 Ye gods! At that price they're an absolute STEAL. As for not shipping to the UK...that just SUCKS, lol!!


----------



## i luvmusic 2

I need to wait and see how much for the shipping.
 4 6AS7G's should be no more than US$17.00-20.00 this what vac^um t@#e.net charge for 5 6AS7G's(3 Chatham and 2 RCA 6AS7G's)


----------



## mordy

Hi TD,
  
 Thank you for providing a rational explanation why the tubes sound better with a PS with the higher amp rating. The PS I am running now is rated 12V/14-15A, but I am only running a single 2.5A tube from it at the present. The old PS was rated at 19V 2.6A.
  
 In conclusion, it appears beneficial to use a more beefy PS, and I am awaiting the results of other people trying this. Once you have a proper PS, it can can be modified in a couple of minutes without cutting or soldering.
  
 Take a 1/2" 0.8 mm copper wire and bend it into a U shape. Locate the 20/24 pin plug and look for the single green wire in the entire tangle. Next to it on either side is a black wire. Push in the U shaped copper wire (a large paper clip cut to size could do the same job) into the connecting sockets for the green and black wires. Cover with electric tape.
  
 Find a connector with a yellow and black wire (should be many of them; ignore other colors) and find a piece of wire that will fit both into the voltage regulator and the computer plug (you could double the the wire for a snug fit in the computer harness). Cover with tape. The yellow wire is + and the black wire is -; just connect to the corresponding connectors on the voltage regulator.
  
 That's it; you are done! You will have a lot of extra wires coming out from the PS - I bundled them up and put the whole harness into a bag, but must admit that it doesn't look esthetically pleasing.
  
 The increased punch in the bass and the increased clarity more than makes up for it.


----------



## mordy

Hi All,
  
 Here is a partial answer to the question: When is Ebay sleeping?
  
 In other words, are there times when you can get a better buy, or are there times when fewer people look for things to buy, resulting in less competition for bids?  On the flip side, are there times when you can expect to get fewer bids or less interest when selling?
  
 The answer is simple and common sense, but maybe this knowledge will help you in snagging a good deal (or avoiding something to go for 99 cents).
  
 Basically, your chances of getting a better buy is when people are busy with other things and don't have time to check Ebay. Such times are national holidays and Saturday nights when many people are busy doing other things. If you are selling something, avoid the auction to finish Saturday night or on the 4th of July, Thanksgiving etc.
  
 On the topic of Chathams 6AS7 tubes, I notice that checking the sold listings for the last sixty days the least expensive tubes went for for $13, $14 and $20 (all prices incl shipping), so Nic's suggestion is certainly very worth wile. In June two Tung Sol 6AS7 tubes went for $15 and $17 incl shipping.


----------



## i luvmusic 2

No luck on the Chatham 6ASG's the seller is not replying to my email about shipping cost to Canada i was gonna buy 4 but then again i don't want to get rip off for the shipping it should not be more than US$20 for all 4 but then again some eba7er charged US $34.99 for 1 tube and some even charged import charges.I hope i will get a reply soon.


----------



## gibosi

i luvmusic 2 said:


> No luck on the Chatham 6ASG's the seller is not replying to my email about shipping cost to Canada i was gonna buy 4 but then again i don't want to get rip off for the shipping it should not be more than US$20 for all 4 but then again some eba7er charged US $34.99 for 1 tube and some even charged import charges.I hope i will get a reply soon.


 
  
 This weekend is is a national holiday in the US, so the vendor may not get back to you until Monday. That said, the vendor would charge $14.00 to ship four tubes in the US, which I think is high....


----------



## i luvmusic 2

gibosi said:


> i luvmusic 2 said:
> 
> 
> > No luck on the Chatham 6ASG's the seller is not replying to my email about shipping cost to Canada i was gonna buy 4 but then again i don't want to get rip off for the shipping it should not be more than US$20 for all 4 but then again some eba7er charged US $34.99 for 1 tube and some even charged import charges.I hope i will get a reply soon.
> ...


 
 Sorry i for got about the US holiday.I hope it will not cost me arm and a leg for the shipping.
	

	
	
		
		

		
		
	


	




THANKS!


----------



## i luvmusic 2

I've got a reply from the Chatham seller,just waiting for the total amount.


----------



## i luvmusic 2

Just bought the 4 Chatham 6AS7G's now it's that waiting game.


----------



## MIKELAP

i luvmusic 2 said:


> Just bought the 4 Chatham 6AS7G's now it's that waiting game.


 
 Waiting for shipping cost how much for you .


----------



## i luvmusic 2

mikelap said:


> i luvmusic 2 said:
> 
> 
> > Just bought the 4 Chatham 6AS7G's now it's that waiting game.
> ...


 
 US $10 for 4 tubes.I was gonna get more but i changed my mind i already have 8 Chatham 6AS7G's(including the 4 i just bought)


----------



## MIKELAP

i luvmusic 2 said:


> US $10 for 4 tubes.I was gonna get more but i changed my mind i already have 8 Chatham 6AS7G's(including the 4 i just bought)


 
 Thanks ,response is long probably missed them no matter theres always a next time


----------



## i luvmusic 2

mikelap said:


> i luvmusic 2 said:
> 
> 
> > US $10 for 4 tubes.I was gonna get more but i changed my mind i already have 8 Chatham 6AS7G's(including the 4 i just bought)
> ...


 
 I email the seller since yesterday and i just got the reply few hours ago,Just wait and see.


----------



## i luvmusic 2

Vacuum Tu3e.net said they get Chatham all the time but it's being sold quickly i've just got their last 3 last week.


----------



## MIKELAP

i luvmusic 2 said:


> Vacuum Tu3e.net said they get Chatham all the time but it's being sold quickly i've just got their last 3 last week.


 
 Like you i have several pairs one thing i dont know is how many hours they are  rated for!


----------



## TrollDragon

mikelap said:


> Like you i have several pairs one thing i dont know is how many hours they are  rated for!


They will probably outlive the amplifier...


----------



## MIKELAP

trolldragon said:


> They will probably outlive the amplifier...


 
 Thanks .


----------



## TrollDragon

No Pwawbwem... Anytime!


----------



## hypnos1

i luvmusic 2 said:


> US $10 for 4 tubes.I was gonna get more but i changed my mind i already have 8 Chatham 6AS7G's(including the 4 i just bought)


 
  
 OMG...this gets worse! I had to pay $26 just for postage/import handling(?!)...for *ONE* tube. Rip-off or what, eh? Ah well, we live and learn...the HARD way - for me anyway, lol!
  
 Anyway, I'm glad you guys are getting these wonderful tubes for VERY reasonable money...(I hate you all! 
	

	
	
		
		

		
		
	


	




).
  
 Enjoy...


----------



## i luvmusic 2

mikelap said:


> i luvmusic 2 said:
> 
> 
> > Vacuum Tu3e.net said they get Chatham all the time but it's being sold quickly i've just got their last 3 last week.
> ...


 
 Will i have advantage over you, your WOO need a pair to run my Crack only need one so looks like TD is right this tubes will definitely out lived my Crack.........


----------



## i luvmusic 2

hypnos1 said:


> i luvmusic 2 said:
> 
> 
> > US $10 for 4 tubes.I was gonna get more but i changed my mind i already have 8 Chatham 6AS7G's(including the 4 i just bought)
> ...


 
 That's too bad,is it from the same seller where i got mine?WOW


----------



## i luvmusic 2

Hi Mikelap,
     Did you get a reply from The Chatham Seller?


----------



## mordy

Tried to find out the life span of a 6AS7 tube - the only information I found was 5000 hours. The 6SN7 octals are supposed to last 10,000 hours.


----------



## MIKELAP

mordy said:


> Tried to find out the life span of a 6AS7 tube - the only information I found was 5000 hours. The 6SN7 octals are supposed to last 10,000 hours.


 
 Not much infos out there checked the 6AS7 Thread didnt see nothing about it or on the web.Thanks mordy


----------



## MIKELAP

i luvmusic 2 said:


> Hi Mikelap,
> Did you get a reply from The Chatham Seller?


 
 No not yet ,i saw on the guys site that there was no bundling forget the term ,but you said it was $10.00 for shipping so will see soon enough .


----------



## genclaymore

I bought a pair of 6ZH1P-EV But I got 6ж1n-EB  I can't find where I seen what they was, But I wanted to make sure if they are the same thing. Because the russian letters throw me off. I mainly wanna make sure I got what I paid for.


----------



## MIKELAP

genclaymore said:


> I bought a pair of 6ZH1P-EV But I got 6ж1n-EB  I can't find where I seen what they was, But I wanted to make sure if they are the same thing. Because the russian letters throw me off. I mainly wanna make sure I got what I paid for.


----------



## genclaymore

mikelap said:


>


 

 Thank's


----------



## MIKELAP

i luvmusic 2 said:


> Hi Mikelap,
> Did you get a reply from The Chatham Seller?


 
 Got reply just now shipping is $18.00 for 4 tubes looks like shipping charges are fluctuating lol where are you in Canada ! Anyways i got 4 tubes so now im set for life hmm i think i said that before lol.


----------



## hypnos1

i luvmusic 2 said:


> That's too bad,is it from the same seller where i got mine?WOW


 
  
 Hi ilm2. Sorry for the late reply...toooo busy, lol!
  
 But no, not your seller....lucky you! What's all the more galling is that another seller charged me just $12...I smell something fishy 
	

	
	
		
		

		
			





. Not only that, but I asked for a Tung Sol/Chatham, but got a Tung Sol...no copper posts, and doesn't look half as good - just like a bog-standard RCA in fact. Don't think I'll even bother to pop it in - getting real crotchety in my old age!. Thank God I do at least have a spare pair of the real thing...


----------



## i luvmusic 2

mikelap said:


> i luvmusic 2 said:
> 
> 
> > Hi Mikelap,
> ...


 
 Good for you,I'am from GTA So he charged me US$10 for 4 tubes.


----------



## i luvmusic 2

hypnos1 said:


> i luvmusic 2 said:
> 
> 
> > That's too bad,is it from the same seller where i got mine?WOW
> ...


 
  You're right some of them will charged you arm and a leg.Example i bought 4 6080 from this vendor he charged $16 for the shipping then few weeks later i email him if he have more 6080 he replied Yes then i asked for total amount this time my shipping charge is $26 WHAT
	

	
	
		
		

		
		
	


	




.So you need to watch the shipping cost i usually asked the seller if he can lower the shipping cost and some of them will do that.


----------



## gibosi

hypnos1 said:


> . Not only that, but I asked for a Tung Sol/Chatham, but got a Tung Sol...no copper posts, and doesn't look half as good - just like a bog-standard RCA in fact. Don't think I'll even bother to pop it in - getting real crotchety in my old age!. Thank God I do at least have a spare pair of the real thing...


 
  
 My current thinking is that of the American manufacturers, only RCA and Chatham manufactured 6AS7's, not Raytheon, not Sylvania, not GE, and not Tung-Sol (before the acquisition of Chatham). Like you, I have seen early (before Chatham) TS tubes that were obviously manufactured by RCA.  
  
 I haven't been looking at these tubes all that long, so it is likely that I have't seen every permutation, but so far, my rule of thumb is if it doesn't have copper grid posts, it is not a Chatham. Further, I have yet to see an RCA with copper grid posts. Also, I have yet to see a Chatham with top getters, only two bottom getters. On the other hand, the cleartop RCA's have only one bottom getter, and again, steel grid posts.
  
 Of course, there may well be some exceptions, but so far, these observations appear to be true....


----------



## MIKELAP

i luvmusic 2 said:


> Good for you,I'am from GTA So he charged me US$10 for 4 tubes.


 
 Just for fun i checked with Google Earth and it seems that Montreal is 100 k.m. closer to the guys location than Toronto so when they tell you that they dont play with the shipping prices thats excuse my french  BS i would think. By the way only 5 tubes left


----------



## hypnos1

gibosi said:


> My current thinking is that of the American manufacturers, only RCA and Chatham manufactured 6AS7's, not Raytheon, not Sylvania, not GE, and not Tung-Sol (before the acquisition of Chatham). Like you, I have seen early (before Chatham) TS tubes that were obviously manufactured by RCA.
> 
> I haven't been looking at these tubes all that long, so it is likely that I have't seen every permutation, but so far, my rule of thumb is if it doesn't have copper grid posts, it is not a Chatham. Further, I have yet to see an RCA with copper grid posts. Also, I have yet to see a Chatham with top getters, only two bottom getters. On the other hand, the cleartop RCA's have only one bottom getter, and again, steel grid posts.
> 
> Of course, there may well be some exceptions, but so far, these observations appear to be true....


 

 Hi g.
  
 You have confirmed my worst fears... that d***ed tube has cost me many times what I paid for my inferior RCAs...just might take it up with the vendor. But  then, is it worth the hassle? Perhaps not... just put it down to experience, lol!
  
 I do actually have a Tung Sol Chatham that has copper posts and TOP getter... will post a photo tomorrow... time for bed.


----------



## MMMan

Hi Everybody!!

I just got my LD mk iv about 6 weeks ago... And found this thread about 3 weeks ago. It is pure gold!!

I'm currently on page 81, and enjoying every nugget!! I can't wait to catch up to page 453, but I'm going to take my time and follow you on your journey with each new tube class.

Thank you all so much, it has been fantastic so far!!!

Best,

Gordon


----------



## hypnos1

mmman said:


> Hi Everybody!!
> 
> I just got my LD mk iv about 6 weeks ago... And found this thread about 3 weeks ago. It is pure gold!!
> 
> ...


 
  
 Hi Gordon (MMMan). Welcome to the thread.
  
 Congrats on getting what I am sure you will EVENTUALLY(!) discover to be one of the (if not THE) best bargains in headphone amps...assuming you manage to wade through ALL the progress that has been made since page 81, lol! I do hope you manage to hang in there - if so, you will be handsomely rewarded -  _guaranteed_!
  
 I applaud you for doing the proper "leg-work" - not everyone is prepared to put in the time and effort, sadly. In doing so, I am sure you will pick up a great deal of information and advice on many topics besides just pure "tube rolling". And any further info/advice you may need will be willingly given by the marvellous guys on this thread (a thread matched by VERY few for bonhomie, patience, understanding, helpfulness...the list goes on. And, unlike many, there is a refreshing lack of "disdain" for those with more lowly units, and/or those with limited knowledge and experience just starting out on this road).
  
 But I do hope you aren't going to be spending the sort of bucks _we_ all have had to in order to reach "nirvana"...skip on the spending until you reach near the end, lol!! Learn from _our_ expenditure...not to mention mistakes!
  
 Cheers, and HAPPY ROLLING
  
 CJ


----------



## hypnos1

As promised, picture of the Tung Sol/Chatham 6AS7G, with top getter...
  
 Interesting that the tube is slightly more elongated than the "pure" Chatham with bottom D getters.


----------



## CollectoR13

Wow, those chathams look great... 
So, hypothetically, what do i need to make my 6sn7 sockets ready for those 6as7s?
I know I need a external power supply, but what exact board do I need? 
And do I have to short one connection in my adapters and wire it to the power supply? 
Is that how you can achieve this? 
Sorry but I have no clue about these external power supply things...


----------



## kvtaco17

hypnos1 said:


> As promised, picture of the Tung Sol/Chatham 6AS7G, with top getter...
> 
> Interesting that the tube is slightly more elongated than the "pure" Chatham with bottom D getters.


 
 That's identical to the one that dies on me... Loved that tube lol


----------



## gibosi

hypnos1 said:


> As promised, picture of the Tung Sol/Chatham 6AS7G, with top getter...
> 
> Interesting that the tube is slightly more elongated than the "pure" Chatham with bottom D getters.


 
  
 Thanks for the pic! I have seen bottom getter Chatham 6AS7's with the same exact plates, that is, an unpainted band at the top and bottom, and yellow lettering on the base, so there is no doubt in my mind yours is a "real" Chatham.
  
 As your tube was packed in 1960, one might speculate that Chatham's with top getters were all manufactured around 1960 and later. And perhaps, those with bottom getters were probably manufactured in the 1950's. So for example, a couple of bottom getter Chathams I see on eBay, dated 639 and 522 were probably manufactured in the 1956 and 1955, respectively.


----------



## gibosi

collector13 said:


> Wow, those chathams look great...
> So, hypothetically, what do i need to make my 6sn7 sockets ready for those 6as7s?
> I know I need a external power supply, but what exact board do I need?
> And do I have to short one connection in my adapters and wire it to the power supply?
> ...


 
  
 As my 1+ doesn't have power tubes, Mordy and Hypnos1 might be able reply in more detail.
  
 However, you will need two 6SN7 to 6DJ8 adapters, such as these:
  
 http://www.ebay.com/itm/1pc-6SN7-6H8C-6N8P-CV1988-B65-VT231-TO-ECC88-6922-6DJ8-6N6-6N11-tube-adapter-/201083508552?
  
 And you will need two 9-pin socket savers, such as these:
  
 http://www.ebay.com/itm/1pc-6SN7-6H8C-6N8P-CV1988-B65-VT231-TO-ECC88-6922-6DJ8-6N6-6N11-tube-adapter-/201083508552?
  
 Next, you would disassemble the socket savers and drill a hole in the housings, preferably facing towards the back of the amp. Inside the saver, solder some lamp wire to pins 4 and 5 and route the wire through the hole. Reassemble the savers and then cut off pins 4 and 5 from the bottom of the saver. Mordy has a great picture and explanation here:
  
 http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/6405#post_10612269
  
 Next, you need a power supply. Some have used desktop computer power supplies, but an 8A laptop power supply similar to this would also work:
  
 http://www.ebay.com/itm/120W-15V-8A-AC-Power-Adapter-Charger-Power-Supply-for-Toshiba-Laptop-Computer-/310985342634?
  
 and you need an 8A regulator, similar to this:
  
 http://www.ebay.com/itm/300839166993?
  
 Connect the PS to the regulator and adjust the regulator for 6.3V. Connect pins 4 of both savers together and pins 5 together, connect these wires to the output of the regulator... And you _should_ be good to go.


----------



## MMMan

hypnos1 said:


> Hi Gordon (MMMan). Welcome to the thread.
> 
> Congrats on getting what I am sure you will EVENTUALLY(!) discover to be one of the (if not THE) best bargains in headphone amps...assuming you manage to wade through ALL the progress that has been made since page 81, lol! I do hope you manage to hang in there - if so, you will be handsomely rewarded -  _guaranteed_!
> 
> ...




Thanks for the welcome CJ. 

i am very patient and fully appreciate the wealth of knowledge this thread represents. My intent on starting at the start was so that I could enjoy some of the side-arc adventures each of you has shared. Perhaps my nirvana is to be found in one of these arcs, instead of at the end. Besides, if I have nothing of value for comparison, how can I appreciate your nirvana?

So, today I am running a pair of beautiful 1944 tung sol 6ak5w (mil version) as my drivers. Yesterday I dropped in a pair of 1978 6n6p-I power tubes (from Souz factory ) and they opened up the sound beautifully!! Beautiful treble, fantastic detail and very good solid deep bass. If it gets better than this, I can't wait!!

Btw, I listen with Sennheiser HD650s and through Klipsch ref series 61 speakers. I use a cheap t-amp to power the speakers, with the LD mk iv as pre-amp. The t-amp is beautifully transparent and preserves the tube pre-amp sound wonderfully....

Best wishes to all, and thanks for this wonderful thread!!!

Gordon


----------



## mordy

Welcome to the thread MMMan,
  
 Gibosi's instructions are very good and thorough. However, regarding soldering in the wires into the socket extenders to the voltage regulator, it may be helpful to desolder the two pins 4&5 inside. Just remove them, and then solder in the wires into the socket pins inside the extender. This avoids cutting the pins and makes more room inside for the wires. Afterwards, a little piece of colored tape or similar may be used to mark where to insert the socket extender into the the LD socket.
  
 IMHO a PC 400-500W 15A power supply will yield better results sonically than a laptop PS or similar lower powered PS.
  
 I am happy to hear that you enjoy the sound of your MKIV with the TS and 6N6P-i tubes. But, if good is good, isn't better better?
  
 You should know that using the top tier driver tubes and octal power tubes described in the more recent posts yields a sound that is several orders better than what you have now. And by reading carefully, you can find out how to achieve this at a low cost....


----------



## MMMan

mordy said:


> Welcome to the thread MMMan,
> 
> Gibosi's instructions are very good and thorough. However, regarding soldering in the wires into the socket extenders to the voltage regulator, it may be helpful to desolder the two pins 4&5 inside. Just remove them, and then solder in the wires into the socket pins inside the extender. This avoids cutting the pins and makes more room inside for the wires. Afterwards, a little piece of colored tape or similar may be used to mark where to insert the socket extender into the the LD socket.
> 
> ...




Thank you for the greetings Mordy. I'm glad you are still so passionate about your sound. 

I have a pair of GE 6cb6a tubes in my hand..... And a grab bag of 6485 s in the post, including 4 TS tubes, so I am ready to roll!! No short cuts here....

I'm sure I will catch up to power tube mods in about a year.

Best,

Gordon


----------



## tjw321

hypnos1 said:


> ... And any further info/advice you may need will be willingly given by the marvellous guys on this thread (a thread matched by VERY few for bonhomie, patience, understanding, helpfulness...the list goes on. And, unlike many, there is a refreshing lack of "disdain" for those with more lowly units, and/or those with limited knowledge and experience just starting out on this road).


 
 +1. I'm a new "member" of the tube rolling fraternity, and in my experience this is the most welcoming and least judgemental thread of any that I've posted-on on head-fi.
  
 Thanks guys.


----------



## TrollDragon

Hey Girls!
  
 You need to check this post out for a nice bit of research from a MK III owner!
 http://www.head-fi.org/t/439449/little-dot-mk-iii-mods/135#post_10697619


----------



## hypnos1

collector13 said:


> Wow, those chathams look great...
> So, hypothetically, what do i need to make my 6sn7 sockets ready for those 6as7s?
> I know I need a external power supply, but what exact board do I need?
> And do I have to short one connection in my adapters and wire it to the power supply?
> ...


 
  
 Hi CR13. Glad to see you're keeping an eye on the thread...are you a glutton for punishment, or what?! 
	

	
	
		
		

		
		
	


	




.
  
 Also glad that gibosi (as always!) looks out for us all, and has given you good info - even though he doesn't have power tubes himself (is that keen, or what?!). Thanks also to mordy for his assistance...again, as always...I must admit, though, that my 12V, 6A, AC/DC power supply (for LED string lights, CCTV cameras etc) that can be found on ebay for $7 to $9 (free shipping from China) or $8 + shipping from Amazon, has been doing the job marvellously...no shortcomings in bass or detail/clarity in my set-up at least (I do have a good mains filter/conditioner for all my equipment though...).
  
 I must admit the TS Chatham in the photo is a _tad_ sexier than the clear-top, bottom getter (older) Chathams, but that's just being picky - they too are real sexy, lol! And the sound is so good from 'em that I can't even yet be bothered to take them out and test the TS/Ch'm!
  
  


kvtaco17 said:


> That's identical to the one that dies on me... Loved that tube lol


 
  
 I feel your pain, kvt...please tell me they aren't short-lived! 
	

	
	
		
		

		
		
	


	




.
  
  


gibosi said:


> Thanks for the pic! I have seen bottom getter Chatham 6AS7's with the same exact plates, that is, an unpainted band at the top and bottom, and yellow lettering on the base, so there is no doubt in my mind yours is a "real" Chatham.
> 
> As your tube was packed in 1960, one might speculate that Chatham's with top getters were all manufactured around 1960 and later. And perhaps, those with bottom getters were probably manufactured in the 1950's. So for example, a couple of bottom getter Chathams I see on eBay, dated 639 and 522 were probably manufactured in the 1956 and 1955, respectively.


 
  
 Yes, I have Chathams with and without the unpainted bands. And it does look like the later ones - especially when Tung Sol became involved - went over to top getters. So the moral of the tale is to make absolutely sure one gets the Tung Sol/Chatham _proper, _if going Tung Sol (mine off ebay had photos, so I was OK. The one that came NOT off ebay, and with no pic, was just "Tung Sol" and thus - it would appear - the inferior (IMHO) RCA).
  


trolldragon said:


> Hey Girls!
> 
> You need to check this post out for a nice bit of research from a MK III owner!
> http://www.head-fi.org/t/439449/little-dot-mk-iii-mods/135#post_10697619


 
  
 That, TD, is for AMAZONIAN girls methinks! Most of us are far lesser mortals, I fear! From the look of things, there's one Hell of a lot of parameters to be aware of when dabbling in the finer points of amp electronics...and the opportunity for one Hell of a lot of (expensive) mistakes lol!!
 The more I TRY to make sense of what's going on with DIYers, the more amazed I am at what these LDs can keep taking without _major_ objection/catastrophe! Long live the little marvels - hopefully!
  
 Edit: ps...nice to see at least _some_ useful upgrades in the MKIV SE


----------



## genclaymore

So Far I enjoying my 6J1P-EB and my 6h30PI pair with my little dot mk 2 2.0. It took me a long time to pick between the power tubes and driver tubes. to get what I wanted. After I got the power tube down, I had to closed my eye and pick one of the 3 driver tubes that I was looking at.


----------



## kvtaco17

hypnos1 said:


> I feel your pain, kvt...please tell me they aren't short-lived!
> 
> 
> 
> ...


 
  
 One of mine lost vacuum...BUT I assume it was damaged in shipping and I passed quickly after I used it (3 weeks) I did however find that the Chatham 6080 with the same plate construction sound very similar, just a touch less lush and a little more controlled. Short story is that I ended up loving them... one of my favorite tubes, I only prefer the 5998 and TS/Chatham graphite plate 6336 more.


----------



## hypnos1

kvtaco17 said:


> One of mine lost vacuum...BUT I assume it was damaged in shipping and I passed quickly after I used it (3 weeks) I did however find that the Chatham 6080 with the same plate construction sound very similar, just a touch less lush and a little more controlled. Short story is that I ended up loving them... one of my favorite tubes, I only prefer the 5998 and TS/Chatham graphite plate 6336 more.


 
  
 Phew! Looks like you were just unlucky with that tube, kvtaco17...I can breathe once more, lol! 
	

	
	
		
		

		
		
	


	




. Am glad you confirmed the right choice of 6AS7G...
  
 Couldn't wait any longer, so I've just popped the NOS TS/Ch'm in the left channel, with the Chatham in the right, and straight out of the box sounds loooovely. (And is definitely taller than the Chatham).
  
 Unfortunately, with the price of a 5998 now in the realm of cloud cuckoo land and the 6336 having 5A heater draw and *30W*! plate dissipation, methinks my MKIV SE just can't be punished any further! 
	

	
	
		
		

		
		
	


	




. Ah well, mustn't be greedy - the sound I am now getting is way beyond expectation 
	

	
	
		
		

		
		
	


	




...


----------



## kvtaco17

hypnos1 said:


> Phew! Looks like you were just unlucky with that tube, kvtaco17...I can breathe once more, lol!
> 
> 
> 
> ...


 
  
 They are warm, power hungry tubes for sure!
  
 They all have similar qualities, the 5998 is the most spacious, detailed and dynamic of the trio, the 6336 has incredible bass and sweet treble and the 6080 sounds a lot like a 5998 minus the dynamics and has less detail... it however has a sweeter midrange. All glorious!


----------



## mordy

Hi kvtaco 17,
  
 From what I read some people prefer the plain vanilla RCA 6AS7 tubes to the TS/Chatham tubes. Could you describe the difference in sound? One source claimed that the TS/C tubes are a little better, but don't justify the great difference in price.


----------



## tjw321

I've just received a complete set of valves for my Little Dot MK III from tubes-store.com which got held up on the way so I can't even remembered if there was any specific reason for ordering them. I think I got these:
  
http://tubes-store.com/product_info.php?currency=USD&products_id=295
  
 (6N6P-IR / ECC99 / E182CC)
  
 to try with my Ei 6HM5, and these:
  
http://tubes-store.com/product_info.php?currency=USD&cPath=&products_id=736
  
 (6J1P / 6AK5 / EF95 / 6F32)
  
 because, well it seemed silly not to at $1 each....
  
 Anyway, being in a hurry, and not remembering my plan to pair with the 6HM5, I just put them all in to make sure that they were working and it turns out that they're pretty d*mn good! I'm not sure if those $1 tubes are supposed to be good, but regardless, I think that the main reason is for some reason the gain is lower, so I can turn the dial up into the "sweet zone" (i.e. more than the 9 o'clock that I'm usually limited to).
  
 As usual, more listening, and more experimentation is required....particularly with the 6HM5s...


----------



## kvtaco17

mordy said:


> Hi kvtaco 17,
> 
> From what I read some people prefer the plain vanilla RCA 6AS7 tubes to the TS/Chatham tubes. Could you describe the difference in sound? One source claimed that the TS/C tubes are a little better, but don't justify the great difference in price.


 
 I found the Chatham's to have a better sense of air and detail and better dynamics... The RCA's are warmer and more lush sounding. The RCA's are good sounding tubes, just not the most detailed or airy... they do pair well with can's that need help taming treble. I own both and greatly prefer the sound of the Chatham's... to save a few dollars check out Chatham's 6080's... they sound very similar and typically are quieter.


----------



## i luvmusic 2

Hi Guys,
  Anybody know if this is a DUAL MONO or DUAL STEREO Volume Attenuator?Thanks!


----------



## TrollDragon

Looks dual mono to me, ask the seller...


----------



## i luvmusic 2

trolldragon said:


> Looks dual mono to me, ask the seller...


 
   Yes i did asked the seller still waiting for the reply from Chinada.I hope it's not a MONO or else i need to reorder another attenuator the CRACK should be shipping in a few weeks according to the email i've got.Thanks!


----------



## i luvmusic 2

Ok i've got a reply from the attenuator seller he confirmed that the attenuator he send me is a DUAL STEREO(Resistors are connected in series for stereo mode)according to him MONO mode usually connected in parallel which is he does not sell.Is this make sense?


----------



## TrollDragon

In a Chinglish sort or way...
I see the two sections as seperate pots hence the mono thought. Infact it is like any other dual volume control except it's stepped instead of smooth motion.

I find the only problem with a 28 step attenuator is there seems to be times when you want a step in between...

Now MIKELAP has a 48 step one and it would be perfect, but they cost a little less than the Crack itself... 

Hopefully on this attenuator they used precision resistors or you might just have a channel imbalance... 

Most people use Goldpoint's in their projects.
http://www.goldpt.com/compare.html


----------



## i luvmusic 2

trolldragon said:


> In a Chinglish sort or way...
> I see the two sections as seperate pots hence the mono thought. Infact it is like any other dual volume control except it's stepped instead of smooth motion.
> 
> I find the only problem with a 28 step attenuator is there seems to be times when you want a step in between...
> ...


 
   I think for my first DIY amp i should be ok with this one it cost $23 not bad for a amateur like me.If i blow it up i can always buy a next one for cheap and i don't know if the attenuator can improved the amp SQ i have to hear it first before i dropped some big $.Thanks TD!


----------



## TrollDragon

It's a volume control with click stops... If it is made properly with precision components it will sound no different than a non click, quality made volume control...

To purchase the (48) 0.1% precision resistors from a quality manufacturer like Vishay Dale. It would cost you more than the price of your attenuator.

Like most things, you get what you pay for and I hope it works fine for you, but you might just want to have a nice Alps Pot queued up in your eBay cart just incase.


----------



## gibosi

Has anyone tried a 5687 dual triode?
  
 It appears to be a good tube for audio:
  
 http://www.aca.gr/index/hiend/hiendArticles?row=2609
  
 Unfortunately, it has a different pin-out than either a 12AU7 or 6DJ8, but since when has that been a problem? lol 
  
 http://frank.pocnet.net/sheets/049/5/5687.pdf


----------



## tjw321

tjw321 said:


> ...they're pretty d*mn good! I'm not sure if those $1 tubes are supposed to be good, but regardless, I think that the main reason is for some reason the gain is lower, so I can turn the dial up into the "sweet zone" (i.e. more than the 9 o'clock that I'm usually limited to).
> 
> As usual, more listening, and more experimentation is required....particularly with the 6HM5s...


 
 False alarm. The 6HM5s are much better.... I'd just been away for a few days and hadn't had a chance to listen to the LD for a while so was surprised (again!) at just how good it sounds. Definitely worth $1 for the occasional listening session with something different (as opposed to better), though.


----------



## Nic Rhodes

the 5687 has much more in common with E182CC, 7119, CV5188, 7044, CV5766 type tubes and their expensive brother 6900 (Bendix and others made this). All are excellent at audio, in fact my best amp uses both 5687 and E182CCs in different locations. The 5687 are famed for use in the Audio Note Ongaku. The tube that is perhaps closest to these is the 6N6P but with a different pin out already used in the outputs of our LDs! I believe early LDs came with E182CC before the change to 6N6Ps. My favourite 5687s have been the Tung Sols though there are many other excellent makes (RCA Command, GE 5*, Sylvania GB, Raytheon, PhilipsECG).


----------



## hypnos1

mordy said:


> Welcome to the thread MMMan,
> 
> 
> 
> IMHO a PC 400-500W 15A power supply will yield better results sonically than a laptop PS or similar lower powered PS.


 
  
 Hey mordy (and iluvmusic2)...you have a lot to answer for! Being more than happy with my encapsulated (laptop-like) external power supply, your experiments with PC PSs have had me itching to try something else...Looking around, I found a good deal on a used "medical grade" 15V 10A unit that seems quite interesting, and which in theory should be much better than my current choice...perhaps?!
 It's made by AstroDyne, who appear to be quite a specialist outfit, so it will be very interesting to see what the outcome is once I get my eager fingers on it, lol!
  
 Some pics to be going on with...will have to cobble together a metal enclosure for it, but no big deal...


----------



## mordy

Hi h 1,
  
 Looks like massive heat sinks, but if you are going to make a case for it, perhaps adding a fan wouldn't hurt. As far as I know, all the PC power supplies I've seen use fans. The one I am using now even has two fans.
  
 I awaiting other people's impressions using higher grade power supplies to see if they concur with my impression.
  
 Last week I saw a sale on a 430W PS for $16 shipped at Newegg, but I did not want to post a link because a quick search revealed a 18% failure rate. It should be possible to get a good 400-500W PS for around $30 with a rebate.


----------



## 8bitBarry

I have new NOS Mullard 5654's installed into my Little Dot 1+ this evening and I am sitting here listening to Amon Tobin's Isam Live - the bass / stereo separation is absolutely astounding!!
  
http://i1273.photobucket.com/albums/y415/davidclapp/headfi-audirvana-bluecat_zps17e6f7a5.jpg
 I'm listening through a set of Sennheiser HD650's and I am actually wondering how much better I can get this system to sound 
	

	
	
		
		

		
			







  
 Is there any particular direction I could go push things EVEN further?
  
 Is there a new level of amp I could be moving towards that other consider to be the next step up?
  
 Its mostly EDM as I am a self confessed basshead....
  
 8bitBarry


----------



## gibosi

hypnos1 said:


> Hey mordy (and iluvmusic2)...you have a lot to answer for! Being more than happy with my encapsulated (laptop-like) external power supply, your experiments with PC PSs have had me itching to try something else...Looking around, I found a good deal on a used "medical grade" 15V 10A unit that seems quite interesting, and which in theory should be much better than my current choice...perhaps?!
> It's made by AstroDyne, who appear to be quite a specialist outfit, so it will be very interesting to see what the outcome is once I get my eager fingers on it, lol!


 
  
 Since your current setup is rated at only 6A, I think it is wise to increase the capacity to at least 7.5A. But I very seriously doubt that anything over that will make any difference.
  
 A pair of 6AS7's draw 5A to run the heaters and this is all that they will take, no matter how much is available. Yes, of course, the PS should have a capacity of more than 5A. These tubes probably draw a bit more than 5A at start-up and further, it is generally not a good idea to run a power supply at maximum output. Most things fail when pushed to their limit.
  
 LD used a factor of about 1.5 in designing both their driver and power heater circuits, and therefore, 1.5 X 5A = 7.5A is plenty, thus my recent recommendation of 8A. And I am sure it will sound just as good as 100A.


----------



## gibosi

8bitbarry said:


> I have new NOS Mullard 5654's installed into my Little Dot 1+ this evening and I am sitting here listening to Amon Tobin's Isam Live - the bass / stereo separation is absolutely astounding!!
> 
> Is there any particular direction I could go push things EVEN further?
> 
> Is there a new level of amp I could be moving towards that other consider to be the next step up?


 
  
 Most of us would suggest double triodes and/or a pair of C3g's.


----------



## gibosi

6SN7M ... metal can 6SN7's.
  
 http://www.ebay.com/itm/PAIR-2-6SN7M-RCA-NOS-BRASILIA-MOST-UNIQUE-6SN7-VERY-RARE-LIMITED-SUPPLY-/231280622226?
  
 It is my understanding that these are simply 6CG7's installed in metal cans. And a pair can be yours for only $168!!


----------



## i luvmusic 2

Personally i would not bother with that type of PS too much work for me.I will get one of those PC PS and be done with it it's already in case.If you really want a PS that looks good just cut those wires short install some type of Female connectors(Maybe a Binding Post, DC Jack, XLR and some other schiit that i don't know) and LED panels  on the PC PS case and they will look pretty(I know you're all about looks).Sound wise PC PS vs. Walwart PS no comment.Did you like that PS because it's MEDICAL GRADE?


----------



## TrollDragon

That AstroDyne power supply would actually be perfect for the job at hand, since all it is designed to do is output 15V/10A. There are no other voltages floating and you don't have to jumper a PG line to get it to fire up or dummy loads that just create heat...

You others be very wary of the $30 PC power supplies, I've seen more than I want to take out main boards...


----------



## mordy

Hi TD,
  
 I meant a $60 PS on sale for $30 LOL. With 2000 feedback and most people very happy I would not worry.....


----------



## 8bitBarry

gibosi said:


> Most of us would suggest double triodes and/or a pair of C3g's.


 
 Could you elaborate further? I am fairly new to all this. I googled C3G's and I see they need a convertor to fit? What do you mean by double triodes - ECC83's or similar?
 Can I fit these to a Little Dot 1+?


----------



## hypnos1

mordy said:


> Hi h 1,
> 
> Looks like massive heat sinks, but if you are going to make a case for it, perhaps adding a fan wouldn't hurt. As far as I know, all the PC power supplies I've seen use fans. The one I am using now even has two fans.
> 
> ...


 
  
 Hi mordy.
  
 As I don't think heat is going to be _too_ much of a problem, I shall try to skip the fan(s) - don't really want motors running in the vicinity, if not necessary lol!
  
  


gibosi said:


> Since your current setup is rated at only 6A, I think it is wise to increase the capacity to at least 7.5A. But I very seriously doubt that anything over that will make any difference.
> 
> A pair of 6AS7's draw 5A to run the heaters and this is all that they will take, no matter how much is available. Yes, of course, the PS should have a capacity of more than 5A. These tubes probably draw a bit more than 5A at start-up and further, it is generally not a good idea to run a power supply at maximum output. Most things fail when pushed to their limit.
> 
> LD used a factor of about 1.5 in designing both their driver and power heater circuits, and therefore, 1.5 X 5A = 7.5A is plenty, thus my recent recommendation of 8A. And I am sure it will sound just as good as 100A.


 
  
 Hi g.
  
 I hear you, mon ami, but what's another 2A amongst friends?! Will be nice to have a little extra in hand 
	

	
	
		
		

		
		
	


	




...(Especially at the price...*$15*!).
  


i luvmusic 2 said:


> Personally i would not bother with that type of PS too much work for me.I will get one of those PC PS and be done with it it's already in case.If you really want a PS that looks good just cut those wires short install some type of Female connectors(Maybe a Binding Post, DC Jack, XLR and some other schiit that i don't know) and LED panels  on the PC PS case and they will look pretty(I know you're all about looks).Sound wise PC PS vs. Walwart PS no comment.Did you like that PS because it's MEDICAL GRADE?


 
  
 Hi ilm2.
  
 "Too much work"? You _are_ kidding me, aren't you?...Considering your (mammoth) jobs of re-housing amps, lol! Would be kid's play to you, no? 
	

	
	
		
		

		
		
	


	




.
  
 Why did I choose it?...Medical grade? YES! Looks _really_ well made? YES! Extremely good spec (TD confirms)? YES! Silly price?($15)...YES! A no-brainer, I thought lol...
	

	
	
		
		

		
		
	


	




.
  


trolldragon said:


> That AstroDyne power supply would actually be perfect for the job at hand, since all it is designed to do is output 15V/10A. There are no other voltages floating and you don't have to jumper a PG line to get it to fire up or dummy loads that just create heat...
> 
> You others be very wary of the $30 PC power supplies, I've seen more than I want to take out main boards...


 
  
 Many thanks, TD, for putting my mind at ease....not money wasted, then...phew! 
	

	
	
		
		

		
		
	


	




.


----------



## hypnos1

Hi folks...yes, it's me _again_!...was supposed to be devoting more time to the garden/fish/little woman, remember?...What is it about this thread that I just can't seem to stay away?...Ah yes...it's so WONDERFUL lol!!
  
 Anyway, just thought I'd post a pic of my (meant to be last) spare Chatham that just arrived...complete with long hairline crack/scratch near the top of the tube, easily visible in the photo.
  
 I have a horrible feeling that repeated heating/cooling is not going to be conducive to a very long life?! 
	

	
	
		
		

		
		
	


	




. Anyway, I've emailed the seller, and hopefully may have some redress if the worst happens...who knows?
  

  
 On this unhappy note I shall say cheerio (for now!) and get back to my garden......etc etc


----------



## genclaymore

It's like hes sending you all his bad tubes or something or he packing them wrong. that sucks that you been getting damaged tube's. You might in up having to try a different seller.


----------



## gibosi

8bitbarry said:


> Could you elaborate further? I am fairly new to all this. I googled C3G's and I see they need a convertor to fit? What do you mean by double triodes - ECC83's or similar?
> Can I fit these to a Little Dot 1+?


 
  
 Yes, C3g's require adapters to work in an LD. And yes, an ECC83 is a double triode. However, I believe the ECC88 and 6SN7 have been more popular in this thread. And yes, double triodes also require "adapters." 
  
 You asked if there were any tubes better than Mullard 5654. And yes, IMHO, there are lots of tubes that are significantly better. Some, like the 6HM5 are "plug and play", and others, such as the 6SN7 require a rather complicated "adapter". To answer your question thoroughly, "Is there any particular direction I could go push things EVEN further?", requires more than a single posting.
  
 I suggest you skim through the last 456 pages of this forum. There is a wealth of information regarding the pros and cons of the many tubes we have tried and how to use them. Having done that, you will then be able to make an informed decision regarding how you wish to "push things EVEN further", and if you do, we will be happy to help you with the details.
  
 Cheers


----------



## i luvmusic 2

hypnos1 said:


> Hi folks...yes, it's me _again_!...was supposed to be devoting more time to the garden/fish/little woman, remember?...What is it about this thread that I just can't seem to stay away?...Ah yes...it's so WONDERFUL lol!!
> 
> Anyway, just thought I'd post a pic of my (meant to be last) spare Chatham that just arrived...complete with long hairline crack/scratch near the top of the tube, easily visible in the photo.
> 
> ...


 
 Sorry about your tube that's too bad it's a nice tube.But you know what you can do if it's not working you can put a LED inside the tube and sell it as a show piece.


----------



## i luvmusic 2

I supposed to be doing some research about the CRACK build but each time i'am in that page i got chill and goosebumps seems like most people there are either millioner or Lottory winner they spend tones of $ for the CRACK.Expensive Attenuators,not soo cheap Capacitors not to mention Very Expensive TUBES.As far as i know the most expensive tube that i saw for the LD is a pair of C3g's now it makes me wonder how well the Modified LD compete with the CRACK.


----------



## hypnos1

genclaymore said:


> It's like hes sending you all his bad tubes or something or he packing them wrong. that sucks that you been getting damaged tube's. You might in up having to try a different seller.


 
  
 Hi genclaymore (not part of a famous Scotch Whisky family, are you lol?!)
  
 It looks like it was a genuine oversight by the seller - he's offered me a refund if I want it...can't ask for more than that, really. BUT...as it looks more like a scratch than a crack (fingers crossed!), I might just take a gamble and cover it with some special glass-mending glue, and hope for the best - the tube sounds so GOOD!...this nos tube, together with the nos Tung Sol/Chatham, seems to be giving a bit more "bite" than the two used Chathams. But perhaps things might even out with more burn-in - unless 'N'os is actually better than used os. Then again, as we have found throughout our extensive rolling, there can be noticeable differences between tubes from even the same batch, in a way that seems to defy all logic!
  


i luvmusic 2 said:


> Sorry about your tube that's too bad it's a nice tube.But you know what you can do if it's not working you can put a LED inside the tube and sell it as a show piece.


 
  
 Well, ilm2, as mentioned above, it looks like things just _might_ be OK...and I shan't need to be making "pretty things" - much as I do indeed love 'em, lol!!
  


i luvmusic 2 said:


> I supposed to be doing some research about the CRACK build but each time i'am in that page i got chill and goosebumps seems like most people there are either millioner or Lottory winner they spend tones of $ for the CRACK.Expensive Attenuators,not soo cheap Capacitors not to mention Very Expensive TUBES.As far as i know the most expensive tube that i saw for the LD is a pair of C3g's now it makes me wonder how well the Modified LD compete with the CRACK.


 
  
 As I mentioned a while ago, someone did a comparison between the Crack (with upgraded caps!) and the LD MKIII (with stock tubes!), and felt there was not a _great_ deal between them. And given my amp (the MKIV SE, of course) with C3GS's and Chathams is *WAY* ahead of stock, I would suspect you'd have to spend BIG bucks on all those things you mentioned for possibly only minimal improvement over said LD. Sure would LOVE you, or someone else with the MKIII or IV to do an in-depth shoot-out...Me? I'm not even going to consider giving it a try...my set-up is delivering everything I could ever want. Am not even going to consider the Senn HD 700 or 800...I am certain the 650s are performing to a standard very rarely bettered, and definitely beyond what even the Sennheiser people thought possible from such humble equipment. I firmly believe (IMHO) that although very well-liked, they are capable of far more than generally realised.


----------



## 8bitBarry

gibosi said:


> Yes, C3g's require adapters to work in an LD. And yes, an ECC83 is a double triode. However, I believe the ECC88 and 6SN7 have been more popular in this thread. And yes, double triodes also require "adapters."
> 
> You asked if there were any tubes better than Mullard 5654. And yes, IMHO, there are lots of tubes that are significantly better. Some, like the 6HM5 are "plug and play", and others, such as the 6SN7 require a rather complicated "adapter". To answer your question thoroughly, "Is there any particular direction I could go push things EVEN further?", requires more than a single posting.
> 
> ...


 
 Thats excellent. I have a few pairs of ECC83's I could use now, so I will have to get some converters. 
  
 I had a really good tread through your posts and others, to have a look at the C3G's info but I can't find any sound description for these valves. Can you give me any idea of what to expect before buying? Sorry if I have missed something but there's quite a few pages now... (* I started around page 400 where the search feature lead me)
  
 Many thanks in advance. I am learning an awful lot from this thread.


----------



## TrollDragon

8bitbarry said:


> Thats excellent. I have a few pairs of ECC83's I could use now, so I will have to get some converters.
> 
> I had a really good tread through your posts and others, to have a look at the C3G's info but I can't find any sound description for these valves. Can you give me any idea of what to expect before buying? Sorry if I have missed something but there's quite a few pages now... (* I started around page 400 where the search feature lead me)
> 
> Many thanks in advance. I am learning an awful lot from this thread.


We didn't have much luck with any 12AX7's sounding that good as drivers, you might want to look into the tall 6HM5's as a great sounding plug and play tube that requires no adapter.

http://www.ebay.com/itm/6HM5-6HA5-EC900-export-quality-audio-triode-tube-NOS-FREE-SHIPPING-/300879467071


----------



## i luvmusic 2

hypnos1 said:


> genclaymore said:
> 
> 
> > It's like hes sending you all his bad tubes or something or he packing them wrong. that sucks that you been getting damaged tube's. You might in up having to try a different seller.
> ...


 
     HD600 or HD650 will be my next HP i just can't decide which one of the two and still waiting for the price to dropped down a bit they usually do at my local store so i'am keeping eye on it as You may all know i'am a El cheapo so i'am just waiting for that price dropped(Few months ago it was $100 less from the regular price).I saved up for The HD800 then i auditioned the Burson and HD800 i did not like what i heard from that combo plus according to the sales guy he own the HD800 and they are source picky i may need to spend a lot of $ just to get what i want from the HD800(I don't have anymore $ for the source),Then i want the Tesla T1(Brandnew T1 CAD$899.99 at NCIX.ca) but for some reason i can't find a store where i can try the T1 before i purchase.That is why i endup getting the BH CRACK and  i heard alot of good things about the CRACK and HD600/650 pairing another HP i'am considering is the T90 so those 3 HP are my top choices.


----------



## tjw321

trolldragon said:


> We didn't have much luck with any 12AX7's sounding that good as drivers, you might want to look into the tall 6HM5's as a great sounding plug and play tube that requires no adapter.
> 
> http://www.ebay.com/itm/6HM5-6HA5-EC900-export-quality-audio-triode-tube-NOS-FREE-SHIPPING-/300879467071


 
 I think I've pretty much established that I'm terrible at working out which tubes sound best ("audio memory" too short), but FWIW, I'm enjoying the 6HM5s right now.
  
 Talking of my terrible "audio memory", how safe is it to switch tubes immediately after powering off, and then powering up right away? I mean to the tubes/electronics, not to me 
	

	
	
		
		

		
		
	


	




. It's the only way I'll ever be able to definitively pick between tubes.
  
 Right now, though, I just like that I can change things around whenever I fancy a change - helps keep the upgraditis at bay.


----------



## gibosi

8bitbarry said:


> Thats excellent. I have a few pairs of ECC83's I could use now, so I will have to get some converters.
> 
> I had a really good tread through your posts and others, to have a look at the C3G's info but I can't find any sound description for these valves. Can you give me any idea of what to expect before buying? Sorry if I have missed something but there's quite a few pages now... (* I started around page 400 where the search feature lead me)
> 
> Many thanks in advance. I am learning an awful lot from this thread.


 
  
 To run ECC83's, 6DJ8's, 6SN7's and similar double triodes in the LD, the following post might be of help to get you started:
  
 http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/5760#post_10435226
  
 Describing the "sound" of tubes is not one of my strengths - my ears are old and worn out and I simply don't have the necessary discipline and patience. But I can say that the C3g's are among the very best tubes I own (out of 700+ lol). Bass is deep and tight, with very good body. Transparency, imaging and staging are exceptional, with nicely detailed and layered mids. Moreover, the treble is just "there". Not a trace of harshness or sibilance on my Senns 700's.
  
 Hypnos1 is our resident "expert" on the C3g and I suggest you seek out and read his observations regarding this wonderful tube.
  
 Cheers


----------



## TrollDragon

tjw321 said:


> I think I've pretty much established that I'm terrible at working out which tubes sound best ("audio memory" too short), but FWIW, I'm enjoying the 6HM5s right now.
> 
> Talking of my terrible "audio memory", how safe is it to switch tubes immediately after powering off, and then powering up right away? I mean to the tubes/electronics, not to me
> 
> ...


 

 For the LD II, III, IV the capacitors take as little while to discharge so I would personally wait for 30 seconds or so to allow some level of discharge, you can test this by pulling the power cord and observing how long the music remains playing.
  
 I'd disconnect your headphones, power off the LD, wait 30 seconds, put in your new tubes, power back up waiting 30 seconds then plug in your headphones.
  
 There is no protection on the headphone jack or line out of these units, so I would err on the side of caution.
  
 The LD I+ is a hybrid so it sort of does not apply to it since the output is solid state, but I'd still wait a time for the high voltage in the caps to bleed off before putting a new tube in.


----------



## tjw321

trolldragon said:


> For the LD II, III, IV the capacitors take as little while to discharge so I would personally wait for 30 seconds or so to allow some level of discharge, you can test this by pulling the power cord and observing how long the music remains playing.
> 
> I'd disconnect your headphones, power off the LD, wait 30 seconds, put in your new tubes, power back up waiting 30 seconds then plug in your headphones.
> 
> ...


 
 Thanks - much appreciated. 
	

	
	
		
		

		
		
	


	



  
 Now I just have to hope my memory lasts longer than the capacitors....it's about even odds, I'd say.


----------



## gibosi

tjw321 said:


> I think I've pretty much established that I'm terrible at working out which tubes sound best ("audio memory" too short), but FWIW, I'm enjoying the 6HM5s right now.
> 
> Talking of my terrible "audio memory", how safe is it to switch tubes immediately after powering off, and then powering up right away? I mean to the tubes/electronics, not to me
> 
> ...


 
  
 "Immediately" is not all that safe for your equipment. But you don't have to wait all that long, only a couple minutes to allow the circuits to "settle down", before pulling tubes out.
  
 In my opinion, it is most important to protect your headphones. I recommend that you turn the volume down and unplug your headphones... wait a couple minutes and pull the tubes out...  plug-in the new tubes, turn the amp on, and wait a couple minutes.... plug in your headphones...  and finally turn the volume up.
  
 Also, if you have power tubes, it is generally not a good idea to install a cold tubes into an amp with hot tubes. Waiting for all the tubes to cool down a bit prevents electrical arcing and other bad things from happening when you turn the amp on. And again, arcing is a grand way to ruin a pair of headphones, so always unplug your headphones before swapping tubes.
  
 Oh, I see that TD beat me to it! lol 
  
 Edit: I use a 3-foot headphone extension cable between the amp and the headphones. As I do an awful lot of rolling, this practice virtually eliminates wear and tear on the headphone jack.


----------



## tjw321

gibosi said:


> "Immediately" is not all that safe for your equipment. But you don't have to wait all that long, only a couple minutes to allow the circuits to "settle down", before pulling tubes out.
> 
> In my opinion, it is most important to protect your headphones. I recommend that you turn the volume down and unplug your headphones... wait a couple minutes and pull the tubes out...  plug-in the new tubes, turn the amp on, and wait a couple minutes.... plug in your headphones...  and finally turn the volume up.
> 
> ...


 
 Thank you. The extra info about the power tubes is v. useful. I have a Fiio HS2 headphone switcher so I can flip between my HD600s and K702s. I'll switch to a vacant connection to achieve the same effect as your extension cable. I probably wouldn't have thought of that if you hadn't mentioned it.
  
 Thanks everyone.


----------



## MIKELAP

hypnos1 said:


> Hi genclaymore (not part of a famous Scotch Whisky family, are you lol?!)
> 
> It looks like it was a genuine oversight by the seller - he's offered me a refund if I want it...can't ask for more than that, really. BUT...as it looks more like a scratch than a crack (fingers crossed!), I might just take a gamble and cover it with some special glass-mending glue, and hope for the best - the tube sounds so GOOD!...this nos tube, together with the nos Tung Sol/Chatham, seems to be giving a bit more "bite" than the two used Chathams. But perhaps things might even out with more burn-in - unless 'N'os is actually better than used os. Then again, as we have found throughout our extensive rolling, there can be noticeable differences between tubes from even the same batch, in a way that seems to defy all logic!
> 
> ...


 
 Ive had the Woo Audio2 for a while now and when i compare my mk3 with either 6DJ8 OR 6SL7 tubes that i generally use with the amp the Littledot is still very very listenable and i dont use the tubes you guys are using now .compare to the Woo with more bass and warmer sounding the Littledot is a bit thin sounding but like i said very listenable.


----------



## TrollDragon

tjw321 said:


> Thank you. The extra info about the power tubes is v. useful. I have a Fiio HS2 headphone switcher so I can flip between my HD600s and K702s. I'll switch to a vacant connection to achieve the same effect as your extension cable. I probably wouldn't have thought of that if you hadn't mentioned it.
> 
> Thanks everyone.


Nice! I really wanted one of those HS2's but they are gone forever...

An excellent application for the little guy.


----------



## TrollDragon

mikelap said:


>


Nothing like rubbing our noses in it, there *Mista Woo*...


----------



## genclaymore

hypnos1 said:


> Hi genclaymore (not part of a famous Scotch Whisky family, are you lol?!)
> 
> It looks like it was a genuine oversight by the seller - he's offered me a refund if I want it...can't ask for more than that, really. BUT...as it looks more like a scratch than a crack (fingers crossed!), I might just take a gamble and cover it with some special glass-mending glue, and hope for the best - the tube sounds so GOOD!...this nos tube, together with the nos Tung Sol/Chatham, seems to be giving a bit more "bite" than the two used Chathams. But perhaps things might even out with more burn-in - unless 'N'os is actually better than used os. Then again, as we have found throughout our extensive rolling, there can be noticeable differences between tubes from even the same batch, in a way that seems to defy all logic!
> 
> ...


 

 Nah but I wish I was then I be rolling around in money,


----------



## TrollDragon

That WA2 just cries out for some of Herbie's Rings.
http://herbiesaudiolab.net/rx.htm





100% Pure SnakeOil, but they do look fine on tubes!


----------



## 8bitBarry

gibosi said:


> To run ECC83's, 6DJ8's, 6SN7's and similar double triodes in the LD, the following post might be of help to get you started:
> 
> http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/5760#post_10435226
> 
> ...


 
 Thank you my friend, much appreciated information. I am using HD650s so I hope to experience a similar sound.


----------



## mordy

Hi All,
  
 What is this?
  

  
 This is my long awaited dream - to have a Little Dot MK9. Well, not exactly, but this is is a Little Dot MkIII v.MK9 or M9 (pronounced Maiin) for short. {I know, two ii's is in style.}
  
 What we have here is a modded MKIII with the tube complement of a Little Dot  MK9 - two RCA 6080 tubes and a Russian 6H9C - also known as 6N9S/6N9P and equivalent of 6SL7.
  
 Finally got my 15A voltage regulator and hooked it up to my 430W 15A PC PS. The whining noise I heard before at very high volume levels thankfully disappeared. The 6080 tubes run very hot, and if you are not careful you could sustain a burn on your fingers if you touch them. Have my 4" fan running (top right in picture) and the transformer housing reads about 85F or so; not too hot.
  
 At first I tried a pair of Sylvania 6080 tubes as power tubes (and another Sylvania 6SL7 as driver)  but found them to be too sibilant. With the present set up with the two 1960 RCAs and a 1981 Russian driver I was pleasantly surprised at the sound - really nice and sweet and very musical. I guess that the LD amp designer Sword Yung did the tube rolling for me this time...(The LD MK9 uses a Chinese 6N9P tube)
  
 As mentioned, the 6080s need external power, but the 6H9C only draws 0.3A so it is plug and play with an adapter.
  
 As I am listening I am getting more excited about the sound - it really sounds very good!
  
 Just added up the cost of all the pieces needed to make this work, including the tubes: 7 adapters, breadboard, voltage regulator, PS, 3 tubes. It comes out to around $130.  A new MK9 is $518.
  
 http://www.ebay.com/itm/Little-Dot-MK-9-Vacuum-Tube-Amplifier-/201073365088?pt=Vintage_Electronics_R2&hash=item2ed0e81060
  
  
 One piece is missing: The protective circuit to be able to use the M9 with a Direct Coupled (DC) amplifier. (Maybe TD can weigh in on that topic.)
  
 Happy tinkering and tube rolling!


----------



## hypnos1

8bitbarry said:


> Thats excellent. I have a few pairs of ECC83's I could use now, so I will have to get some converters.
> 
> I had a really good tread through your posts and others, to have a look at the C3G's info but I can't find any sound description for these valves. Can you give me any idea of what to expect before buying? Sorry if I have missed something but there's quite a few pages now... (* I started around page 400 where the search feature lead me)
> 
> Many thanks in advance. I am learning an awful lot from this thread.


 
  
 Hi 8bit.
  
 So you're seriously interested in the C3g?...Such a shame you don't have the MKIII or IV (perhaps for Christmas?!), as you could then experience that driver's absolute magic when combined with the 6AS7G power tubes - and spend even _more_ money, lol!
 However, I think I can safely say that there is no better driver for our LDs than the C3g (especially if you can grab a bargain lot that (rarely!) comes along), apart from perhaps the sub-miniatures that gibosi and mordy have been enjoying. Although they are much cheaper than the C3gs, as you will have seen, they require quite a bit of "playing around" with. If you can stretch the pennies, the C3g route is much easier, with the C3g to 6AK5 adapter available on ebay.
 Good luck, whatever you decide to do, and feel free to ask for any assistance, if needed.
  
 Cheers,
 CJ
  


mikelap said:


> Ive had the Woo Audio2 for a while now and when i compare my mk3 with either 6DJ8 OR 6SL7 tubes that i generally use with the amp the Littledot is still very very listenable and i dont use the tubes you guys are using now .compare to the Woo with more bass and warmer sounding the Littledot is a bit thin sounding but like i said very listenable.


 
  
 Ah, mikelap...there you have it. If you had the C3g(S) in the driver seat, feeding the Chathams in your MKIII, I am certain you would find the LD _much_ closer to your Woo, lol! 
	

	
	
		
		

		
			





. (Especially if you upgraded those caps!!).


----------



## TrollDragon

Hey mordy!

I gave up on the protective circuit, I sent the builder my address a couple of months back and I am not going to hound him anymore... It's been almost a year and it looks like he is just plainly not interested or just way too busy for a one off item...


----------



## lemonjelly

Hi I've got a pair of Thomson 6080s installed now, with a 6SN7.  They sound good and hopefully will improve with breaking in.
  
 I was pretty shocked how much current the 6080s pull when I was near stock, ie over 150mA total for amp compared to 50mA or so with 6n6ps.  The increased current draw also meant the 6SN7 got moved out of the operating point I was at as well, from 5.5mA/115v to 3.5mA/95v, cos of the B+ changing from 220v to around 160v.  I ended up reducing the power resistors (the 2 180s) to a 60 and a 110, to try and get the B+ a bit higher, ending up at 193v (+ the 6SN7 being at a better operating point again). 
  
 I also got an 8A power regulator, which I'm using with a laptop supply, but it seems like I have to redo the voltage setting every time I start it.  Just wondered if anyone else has found that or whether mine might be faulty?  Thanks.


----------



## mordy

Hi,
  
 More tube rolling - using two select 1960 RCA 6080s as power tubes with an octal driver. First I tried a Russian 6N9C  (6SL7 ) with good results. Then I tried a 12SL7 GE tube from 1954 that had done duty as a power tube.  It was OK but lacking the wow factor.
  
 Then I went back to the MK9 recipe and tried a Sylvania 6SL7WGT from August 1966 with beige base. Wow! Beautiful, expansive sound, very musical. Had to compare it with the miniature wunderkind, the Raytheon 6832. Very nice sound, detailed, more bass than the Sylvania 6SL7WGT but more analytical - perfect for AFB (where are you? Lost in Japan?)
  
 So there we are: The old quandry - musical or analytical? Both these tubes sound excellent in this environment - we have to see how it shakes out; which one will I prefer? At this stage I don't know; both these tubes are great with the 6080s.
  
 Originally I thought that the RCA 6AS7 tubes would sound better, but for me the 6080s have a fuller sound. Maybe the bargain samples I have from 1965 and 1974 aren't the best ($4 and $5 incl shipping; paid $11 for 7 6080 tubes incl shipping which goes to show that Coke sells). Both Coke bottles have identical construction except that one has black plates and one gray plates.
  
 Hi lemonjelly,
  
 I found that the the voltage fluctuates all the time, but the changes are very minor. I might set the voltage at 6.3V and later it would read 6.27V or 6.31V. I had a situation where the voltage fluctuated much more and determined that the PS was defective and discarded it. Perhaps this is your situation.
  
 It is important IMHO to measure the voltage at the tube pins or tube socket with the tube in place since it may drop more than 1/2V depending on the tube - the more power the tube draws, the bigger the difference.


----------



## lemonjelly

Hmmm mine is a bit different... I wouldn't mind if the voltage was just changing a bit, but it jumps around at less than a volt when first turned on (+LED blinks on the regulator) until I rebias it .  I'm wondering if it might be cos the tubes probably pull more power initially so maybe it's overloading the regulator/PSU (it has 2 6080s in parallel on it).  I do have another PSU that I could try at some point.  Kinda done for a while with messing around so I'll just suffer the hassle rather than change stuff again.  It def stays stable once it's changed to 6.3v so not sure really.  Maybe I'll try a 5.7v or so bias and see if it keeps working after turning off/on (if it's pulling too much at 6.3v at startup maybe it would be OK at a lower voltage).
  
 Anyway I'll definitely reread some bits of this thread and pick a few tubes to roll, fantastic info here !


----------



## mordy

From what I seen on the blog a tube may draw perhaps twice the current (or more) at start up so it may very well be what you think. If the voltage is stable once warmed up I wouldn't worry. However, when I switched to a more powerful PS the sound improved with a better bottom end.
  
 I usually listen through speakers, and at start up there usually is some loud noise or static. In order to spare my ears and speakers, I shut off the speakers until I see the spikes on a LED meter on my receiver that indicates the wattage used. After 30 seconds or I can safely turn on the speakers. What I am seeing on the LEDs is probably the warm up surge.


----------



## gibosi

Mordy,
  
 Since you have those big honking heater power supplies for your output tubes, I really think you should upgrade to some tubes that can better use all the power, perhaps a pair of 6336A or 6528. These draw 5A each. 
  
 http://www.radiomuseum.org/tubes/tube_6336a.html
  
 http://www.radiomuseum.org/tubes/tube_6528.html


----------



## mordy

Hi G,
  
 My PS definitively is not honking, but nice and quiet LOL I do have my sights set on the 5A tubes, but so far only found them at the lowest prices of $25 - 35 each. First plan is to snag some 5998 Chatham tubes, but right now slim pickings. Actually was going to buy from the the guy Nic told us about, but he sold the last five before I could work it out with him.
  
 What do you say about the 7236 tube? Both the 5998 and 7236 draw 2.4A.
  
 Meanwhile I am trying to find out the best driver tube combination for my two Carlson-Stromberg 6080s.


----------



## gibosi

mordy said:


> My PS definitively is not honking, but nice and quiet LOL I do have my sights set on the 5A tubes, but so far only found them at the lowest prices of $25 - 35 each. First plan is to snag some 5998 Chatham tubes, but right now slim pickings. Actually was going to buy from the the guy Nic told us about, but he sold the last five before I could work it out with him.
> 
> What do you say about the 7236 tube? Both the 5998 and 7236 draw 2.4A.
> 
> Meanwhile I am trying to find out the best driver tube combination for my two Carlson-Stromberg 6080s.


 
  
 Unfortunately, 6336's and 6528's are likely the least expensive of the bunch, at $25 - 35 each. Both the Sylvania and Tung-Sol/Chatham 7236's have gotten good reviews, but the cheapest I have seen them is about $35. And the cheapest I have seen 5998 is about $80. So if you can get any of these for your standard price, you will be doing very good indeed!


----------



## hypnos1

Further proof of early onset dementia, I fear!....
  
 Having bought a spare Chatham 6AS7G a while back (not the same one as my recent hiccough!), and as it looked almost new and (supposedly) tested for this and that, I didn't bother to try it in the amp straight away. Yesterday I finally decided to give it a go and yes, you've got it....
	

	
	
		
		

		
		
	


	




...horrid distortion! So I clean the pins - although they looked like new...no change. Then it's into the other socket (blaming my homemade adapter first off)...just the same... 
	

	
	
		
		

		
		
	


	




...then 
	

	
	
		
		

		
		
	


	




. Totally unlistenable! And even more anger - at myself - for not checking it straight away (hence dementia, lol!). I ALWAYS used to...Have emailed the vendor, but I don't hold out _too_ much hope, being the increasingly cynical old b***er that I am! Still, we live in hope...
  
 So, folks, the moral of the tale is : ALWAYS CHECK YOUR TUBES THE MINUTE YOU GET 'EM! But then, y'all always do, don't you?
 Am also now even _more_ peeved that that $15 Chatham seller didn't post to the UK!!
  
 One positive note did come out of the whole saga, however : while checking that the rogue tube didn't wreck my beloved LD (and have me guiltily pondering the la Figaro 339 - how could I?!), I popped  the 6N30P-DR in the right channel on a whim. And...interesting...At first the sound seemed a bit fuller, with a shade more bass...hmmm...But within less than a minute, I had to stop - couldn't stand it any longer. Even with the TS Chatham in the left channel, the wonderful detailed, airy, holographic sound that I have come to love was totally absent. I know it's rather silly to be judging two dissimilar tubes in bed together, but it did reinforce (if it were needed!) the magical qualities brought to the table by the Chatham 6AS7Gs. The sound is just in another league altogether - especially when partnered with the C3gS......still miffed about the duff tube, though!


----------



## Frankzappa92

To those of you whom are owners of it-- how do you guys fancy your Little Dot 1+s?


----------



## 8bitBarry

hypnos1 said:


> Hi 8bit.
> 
> So you're seriously interested in the C3g?...Such a shame you don't have the MKIII or IV (perhaps for Christmas?!), as you could then experience that driver's absolute magic when combined with the 6AS7G power tubes - and spend even _more_ money, lol!
> However, I think I can safely say that there is no better driver for our LDs than the C3g (especially if you can grab a bargain lot that (rarely!) comes along), apart from perhaps the sub-miniatures that gibosi and mordy have been enjoying. Although they are much cheaper than the C3gs, as you will have seen, they require quite a bit of "playing around" with. If you can stretch the pennies, the C3g route is much easier, with the C3g to 6AK5 adapter available on ebay.
> ...


----------



## i luvmusic 2

I love my F@#^ed up LD 1+
	

	
	
		
		

		
		
	


	




 See........

  

  

  

  

  

  


 This last picture i called it BIGFATUGLYDOT 1++
	

	
	
		
		

		
		
	


	




 I forgot more +++++.


----------



## gibosi

frankzappa92 said:


> To those of you whom are owners of it-- how do you guys fancy your Little Dot 1+s?


 
  
 If you want to be able to use low-impedance headphones and IEM's, the 1+ is the best choice. It can use precisely the same driver tubes as the II, III and IV, plus 408A's. Further, in the same way that owners of the other LD's can roll power tubes, owners of the 1+ can roll op amps. On the other hand, if you have high-impedance phones, I believe the LD III strikes a very good balance between quality and cost, and would be a better choice.
  
 Cheers


----------



## 8bitBarry

gibosi said:


> If you want to be able to use low-impedance headphones and IEM's, the 1+ is the best choice. It can use precisely the same driver tubes as the II, III and IV, plus 408A's. Further, in the same way that owners of the other LD's can roll power tubes, owners of the 1+ can roll op amps. On the other hand, if you have high-impedance phones, I believe the LD III strikes a very good balance between quality and cost, and would be a better choice.
> 
> Cheers




Sound information - thanks. I was thinking about an upgrade in the future.


----------



## dabtpa

I love it. The instructions suck and you have to open it up to optimize the impedance to your phones by setting jumper cables. I chose not to and it works fantastically with my Beyer DT 990 Pros and AKG 702s. I did the Voshkod tube upgrade from Yen Audio on eBay (plugged them right in) for $40 and it was well worth it. The Chinese tubes are okay, just a bit "edgy". By the way, they send you RCA cables with it that are marginal. Not junk, but not close to high end either. I am not a super high end cable guy, but I have a minimum standard in quality I go by and theirs' wasn't it.. I am using Belden Synaps RCA cables playing directly from my $1000 Denon SACD into the  LD 1+. The sound is very good. In reality, I would have had to pay allot more to get noticeably better sound. The HIFIMAN EF2a is a good tube amp for $169, but I like the sound a bit better on my LD1+ and the build quality seems noticeably better. Also, when you creep up in price, you could then look at a LD2 or 3. We'll see how the amp holds up over time.Also, I like the fact that it has an on board transformer and not a Wal Wart.


----------



## hypnos1

8bitbarry said:


> Many thanks for the advice and ideas. I'm very captivated my LD 1+ so I would happily invest in another LD system like the mk4. I'm a valve head, I see mileage in this
> 
> 
> 
> ...


 
  
 Hi 8bitBarry.
  
 I personally have preferred the Chatham 6AS7G, as have a good few "heavyweights" using this type of tube...but opinion remains divided. Presumably it all comes down to the rest of the system - especially the drivers used and the headphones. It would also, of course, depend upon personal preference. But I believe it generally boils down to whether you prefer what is termed a "fuller" sound, with more _apparent_ bass weight, which is delivered by the RCA stable (regardless of brand name) and the straight-sided 6080 versions, or the more "holographic", airy sound of the Chathams. I also find the Chathams (or Tung Sol Chathams - NOT the 'plain' Tung Sol) bring out tremendous micro-detail/transients from the C3g...more so than the others mentioned.
 And as for bass, although it may _appear_ slightly less weighty, I find it actually has better _detail_ and of course the greater "3D" separation will, I am sure, have a slight "diluting" effect on the _apparent_ weight (unless I'm mistaken lol!).
  
 As for the "S" version C3g, I personally did find a _slight_ improvement across the board over the standard tube. It all depends on the price you can find them at...they don't really warrant a _great_ deal more but when I was buying, the S was available at the same price as the standard. But later (typical!), some standards appeared at much cheaper prices, so it comes down to luck of the draw (and whether you're prepared to keep waiting in the _hope_ of grabbing a bargain!).
  
 ps. Although the only differences were meant to be in the transconductance readings, I found the tubes to be _very slightly_ different - ie the top of the S version was slightly flatter than the standard...whether that signifies anything much, I don't know...(Of course, I'm referring to when the tube is released from its metal protector!).
  
 Anyway, mon ami, all I can say is that this driver/power pairing is phenomenal...full stop!
  
 Happy rolling!


----------



## hypnos1

Hi folks.
  
 Now my spirits have been lifted once more by reinstating the Chathams, I have to confirm that with further burn-in the New Old Stocks (one Tung Sol Chatham - top getter, and one Chatham - bottom getter/clear top, are delivering even more than the Used Old Stocks...unbelievable! I am once more back on cloud nine, and again in total amazement 
	

	
	
		
		

		
		
	


	




... (can even forgive the seller of the duff tube for not getting back to me yet, lol!).
  
 Oh happy day...


----------



## TrollDragon

​


----------



## hypnos1

trolldragon said:


> ​


 
  
 Couldn't agree with you more, TD...time for me to retire, lol!


----------



## TrollDragon

All in good fun sir, all in good fun.


----------



## hypnos1

trolldragon said:


> All in good fun sir, all in good fun.


 
  
 I'll drink to that too...but mine's a nice merlot/cabernet sauvignon, s'il vous plait...


----------



## genclaymore

I been enjoying my current set of tube's so much I can't explain how they sound with my T90's, even tho I like them I have urge's to grab both M8100 and M8161 but I know I be bleeding money if I do, because It was hard choice between them 3.


----------



## 8bitBarry

hypnos1 said:


> Hi 8bitBarry.
> 
> I personally have preferred the Chatham 6AS7G, as have a good few "heavyweights" using this type of tube...but opinion remains divided. Presumably it all comes down to the rest of the system - especially the drivers used and the headphones. It would also, of course, depend upon personal preference. But I believe it generally boils down to whether you prefer what is termed a "fuller" sound, with more _apparent_ bass weight, which is delivered by the RCA stable (regardless of brand name) and the straight-sided 6080 versions, or the more "holographic", airy sound of the Chathams. I also find the Chathams (or Tung Sol Chathams - NOT the 'plain' Tung Sol) bring out tremendous micro-detail/transients from the C3g...more so than the others mentioned.
> And as for bass, although it may _appear_ slightly less weighty, I find it actually has better _detail_ and of course the greater "3D" separation will, I am sure, have a slight "diluting" effect on the _apparent_ weight (unless I'm mistaken lol!).
> ...




You're very generous with you're knowledge and I for one appreciate that. I've learned a lot from your posts and others on this forum for which I am grateful.


----------



## 8bitBarry

i luvmusic 2 said:


> I love my F@#^ed up LD 1+  See........
> 
> 
> 
> ...




It looks like a red wire / blue wire bomb! I want one.


----------



## TrollDragon

hypnos1 said:


> I'll drink to that too...but mine's a nice merlot/cabernet sauvignon, s'il vous plait...:wink_face:


Coffee and a decent cigar around here.


----------



## hypnos1

8bitbarry said:


> You're very generous with you're knowledge and I for one appreciate that. I've learned a lot from your posts and others on this forum for which I am grateful.


 
  
 Glad we have all been able to help...that's been the main aim of this thread (amongst lighter offerings, lol!).


----------



## hypnos1

trolldragon said:


> Coffee and a decent cigar around here.


 
  
 So long as it's decent _freshly ground_ coffee, you're on!


----------



## gibosi

A 5687WA Tung-Sol manufactured in 1956 arrived in today's mail. Since the pin-out is different than any other tube I own, I rewired my 9-pin socket and then plugged it in. Similar to the 12AX7, this tube can be run at 6.3V or 12.6V. However, I should point out that at 6.3V, this tube draws .9A, so an external heater power supply is absolutely necessary. First impressions, it sounds very good. But of course, considering it is used as a driver in the Audio Note Ongaku, this isn't all that surprising. lol
  
 As has been noted elsewhere, this tube might not be the best tube to use with darker headphones
  
 http://www.head-fi.org/t/600110/2359glenn-studio/10170#post_10714151
  
 but it seems to suit my Senns 700 quite well.


----------



## bbmiller

What are the heater current limitations for both power and driving tubes in the little dot IV SE amplifier?


----------



## JoeDoe

If there are any LD owners who'd like to try the endgame C3G tubes, I'm selling a pair of C3G to 6ak5 adapters. PM me for more info.


----------



## gibosi

bbmiller said:


> What are the heater current limitations for both power and driving tubes in the little dot IV SE amplifier?


 
  
 The two standard 7-pin driver tubes share 1.0A. However, in that it is usually not a good idea to run a circuit at it's maximum rating, many of us do not feel it is safe to use tubes drawing more than .45A each, or .9A total. And even though many of us have used .45A tubes in the past, even that is likely too high. The power tubes share 2.5A. And again, it is probably a good idea to use tubes drawing less than 1.0A each or so.


----------



## mordy

Using external power supplies and voltage regulators for tubes with higher power requirements than the LD was designed for, do you think that there are limits on how much the driver and power circuits can handle?


----------



## gibosi

mordy said:


> Using external power supplies and voltage regulators for tubes with higher power requirements than the LD was designed for, do you think that there are limits on how much the driver and power circuits can handle?


 
  
 We are in uncharted territory here... For sure, it is only reasonable to think that such limits exist, but we do not know what those limits are. To date, a number of us have run 2.5A 6AS7's as drivers with no discernible damage to our LD's. But perhaps a 5.0A 6336 as a driver would be too much? And maybe a pair of 6336's drawing 10A would even be too much as power tubes? We just don't know....  
  
 My best advice is "Go slow...  and be careful"......
  
 Cheers


----------



## gibosi

For those who like a tube to put on a nice light show at night, the 5687 does a pretty good job. Although my phone's camera doesn't do it justice.....


----------



## hypnos1

mordy said:


> Using external power supplies and voltage regulators for tubes with higher power requirements than the LD was designed for, do you think that there are limits on how much the driver and power circuits can handle?


 
  
  


gibosi said:


> We are in uncharted territory here... For sure, it is only reasonable to think that such limits exist, but we do not know what those limits are. To date, a number of us have run 2.5A 6AS7's as drivers with no discernible damage to our LD's. But perhaps a 5.0A 6336 as a driver would be too much? And maybe a pair of 6336's drawing 10A would even be too much as power tubes? We just don't know....
> 
> My best advice is "Go slow...  and be careful"......
> 
> Cheers


 
  
 Hey mordy...from the little trawling I've been doing re the 6336 it looks a real animal - 30W plate dissipation!...WOW...And one DIYer managed to blow several fuses before getting it right. So it would appear to be _real_ tricky territory..."You're a braver man than I, Gunga Din!


----------



## kvtaco17

hypnos1 said:


> Hey mordy...from the little trawling I've been doing re the 6336 it looks a real animal - 30W plate dissipation!...WOW...And one DIYer managed to blow several fuses before getting it right. So it would appear to be _real_ tricky territory..."You're a braver man than I, Gunga Din!


 
 6336 is a beast tube in my Glenn amp... just massive everything! Love it for low impedance cans!


----------



## hypnos1

kvtaco17 said:


> 6336 is a beast tube in my Glenn amp... just massive everything! Love it for low impedance cans!


 
  
 Oh you lucky thing...methinks our lowly LDs don't really inhabit the same territory...more's the pity!


----------



## kvtaco17

hypnos1 said:


> Oh you lucky thing...methinks our lowly LDs don't really inhabit the same territory...more's the pity!


 
 I actually haven't used my LD much since the Glenn OTL showed up... kinda feel bad about it...


----------



## gibosi

On the chance that someone other than myself would like to try 5687 and similar tubes in their LD, below is a connection table. This assumes the use of an external 9-pin socket, two 7-pin Vector test-sockets and an external heater PS.
  
 For the following double triodes: 5687/CV2578/CV5188, 6900, 7044, 7119/E182CC/CV5766
  
 6.3V mode (external PS required)
  
 Connections between the 9-pin socket and two 7-pin Vector test-sockets installed into the LD driver sockets
  
 9 Pin socket                                 Left LD socket                    Right LD socket
  
 1 plate 2                                                                                         5
 2 grid 2                                                                                          1
 3 cathode 2                                                                                    2
 4 heater -- external PS                                                                    
 5 heater -- tied to 4                                   
 6 cathode 1                                          2
 7 grid 1                                                1
 8 heater center tap -- external PS                               
 9 plate 1                                               5
  
 And the end result will look something like this. 
  

  
 Edit: My Little "Monster" Dot.


----------



## i luvmusic 2

I opened my email today and guess what i've got,A shipping confirmation from BH for my CRACK and SB.......YAY i'am soo excited
	

	
	
		
		

		
			





 oh wait that's more work for me


----------



## TrollDragon

Congrats ILM2!


----------



## i luvmusic 2

trolldragon said:


> Congrats ILM2!


 
 THANK YOU! I can't wait.......


----------



## TrollDragon

When I first read that I thought B&H don't sell Crack Amplifiers... 

You going to carve some Celtic designs into the woodwork?


----------



## i luvmusic 2

trolldragon said:


> When I first read that I thought B&H don't sell Crack Amplifiers...
> 
> 
> 
> ...


 
   I'am  thinking about making a new case but with all these work i have at home(Just got back home  2 weeks ago and i have tonnes of work)that will be for later i will build it stock for now because i don't know if i will like it or not.If i do like it for sure it will have a newer box and a 1/8'' thick stainless plate(I have the plate cut to size) and if i don't like it it will be for sale this is the other reason i did not buy the HD650  i need to hear the CRACK first.


----------



## 8bitBarry

Its amazing when you read across other forums like Headfonia that devoid of our informative conversation about Little Dot and valves, everyone raves about the Beyerdynamic A20 being the match made in heaven for the Sennheiser HD650's - does anyone have any point of reference they can share?
  
 And whats all this talk about crack?!


----------



## 8bitBarry

gibosi said:


> On the chance that someone other than myself would like to try 5687 and similar tubes in their LD, below is a connection table. This assumes the use of an external 9-pin socket, two 7-pin Vector test-sockets and an external heater PS.
> 
> For the following double triodes: 5687/CV2578/CV5188, 6900, 7044, 7119/E182CC/CV5766
> 
> ...


 
 You are the mad professor...! I haven't got a clue whats going on... but I like it.


----------



## gibosi

8bitbarry said:


> You are the mad professor...! I haven't got a clue whats going on... but I like it.


 
  
 If you are interested in transforming your LD into a Little Monster Dot, the following post will help you get started:
  
 http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/5760#post_10435226
  
 Cheers


----------



## i luvmusic 2

8bitbarry said:


> Its amazing when you read across other forums like Headfonia that devoid of our informative conversation about Little Dot and valves, everyone raves about the Beyerdynamic A20 being the match made in heaven for the Sennheiser HD650's - does anyone have any point of reference they can share?
> 
> And whats all this talk about crack?!


 
 Please ignore the CRACK it's nothing.


----------



## gibosi

8bitbarry said:


> And whats all this talk about crack?!


 
  
 http://bottlehead.com/product/crack-otl-headphone-amplifier-kit/


----------



## DylanF

I just got some stuff in the mail for my LDMKII.
 Two of 6N6P-i  (just need to check this pair for output/voltages)
 Five of 6J1P-EV (6ZH1P-EV) (need testing for 'matching' pairs)
 There is a person near Reno NV that has the equipment to test/match the tubes.
 I'll post how the sound is after some testing.  This thread was exactly what I needed for information.


----------



## genclaymore

That would have been a cheaper option for my self, If I had a tube tester and knew how to use it.


----------



## TrollDragon

dylanf said:


> I just got some stuff in the mail for my LDMKII.
> Two of 6N6P-i  (just need to check this pair for output/voltages)
> 
> Five of 6J1P-EV (6ZH1P-EV) (need testing for 'matching' pairs)
> ...


Matched pairs are absolutely pointless on the Little Dot MK II, III & IV since the tubes are not run in parallel.

If you think that the tubes are suspect and possibly shorted then by all means get them tested. Paying someone to match them for you will not give you any benefit in the sound and will just make the guy who tests them an easy $20 or more...


----------



## genclaymore

trolldragon said:


> Matched pairs are absolutely pointless on the Little Dot MK II, III & IV since the tubes are not run in parallel.
> 
> If you think that the tubes are suspect and possibly shorted then by all means get them tested. Paying someone to match them for you will not give you any benefit in the sound and will just make the guy who tests them an easy $20 or more...


 
 I thought the power tube's suppose to be matched so it doesn't damaged the amp.


----------



## Artsi

I do not know if i have missed something here. It just have been too busy and no much time to "roll tubes". So happy with two of my latest DIY amps. One with TEN 6SL7GT and 6N6P-IR-s and another one with Russian reflector made 6N9S '86, 6N8S's '65 and 6N13S's from '74. All other tubes have been in one cardboard box. There is enough tubes for the rest of my life, i think.
  
 Hi-fi hobby have took me deeper. Vinyl player with tube amp's is just so good.


----------



## DylanF

trolldragon said:


> Matched pairs are absolutely pointless on the Little Dot MK II, III & IV since the tubes are not run in parallel.
> 
> If you think that the tubes are suspect and possibly shorted then by all means get them tested. Paying someone to match them for you will not give you any benefit in the sound and will just make the guy who tests them an easy $20 or more...


 
 Okay then. I have no idea of the quality, so for peace of mind, I'll get them tested.  The power tubes are supposedly matched, but how would I know? So, I'll get them tested too.  (plus I'm a geeky type and would like to watch the testing process).
 Thanks for the  info, as I didn't know about 'parallel' in the circuit design.
 Dylan


----------



## TrollDragon

genclaymore said:


> I thought the power tube's suppose to be matched so it doesn't damaged the amp.


On power amps with multiple output tubes run in parallel it is best but not on the Little Dots...


----------



## TrollDragon

dylanf said:


> Okay then. I have no idea of the quality, so for peace of mind, I'll get them tested.  The power tubes are supposedly matched, but how would I know? So, I'll get them tested too.  (plus I'm a geeky type and would like to watch the testing process).
> Thanks for the  info, as I didn't know about 'parallel' in the circuit design.
> Dylan


Enjoy the process then, all is good!

I was just letting you and any other new users to this thread that matched tubes are a way for the tube seller to get more money out of you... 

Those new to the little dots see matched pairs of 5654's for $80 a and think wow that great, these must be really good! Then they plug in a pair of $7 6HM5's from Yugoslavia and are totally blown away by the sound of the cheap tubes!

That is what this thread is all about, cheap tubes that sound amazing!


----------



## TrollDragon

Unless you have a $3500+ Eddie Current or Cavalli Audio... Then the $400 each 6DJ8's are as much a bragging right as the $400 Power Cable and RCA interconnects are...


----------



## gibosi

I know that many of you have been waiting with bated breath to hear more about my experience with the 5687.... Yes? lol 
  
 Initial impressions: 1956 Tung-Sol 5687WA
  

  
 The Sylvania 6SN7W and 7963, my reference tubes, have airier highs, while the TS 5687 is somewhat darker. The Sylvania's have a silky smooth mid-range, while the Tung-Sol's is a bit more forward, with more body and fullness. I often see the word "fruity" to describe the mid-range of Tung-Sol tubes and it seems to fit. lol
  
 While the highs on the TS are not as airy as the Sylvania, the highs do not seem to me to be lacking. They are just "there" without calling any extra attention to them. The TS has a very liquid and fluid presentation, very quiet, with exceptional transparency and mid-range detail. There is the sensation of being able to hear very deep into the music, with the vocals and instruments often presented in startling clarity.
  
 Having amassed a collection of some 700 tubes that can be used in the LD, I have come to the conclusion that there is no Holy Grail. There are lots of really wonderful tubes out there, and as a colleague puts it, it isn't black or white, it's just subtle shades of gray.  In the end, it really comes down to synergy. Everyone has different equipment, different headphones/speakers, different ears, a different brain and even different genres of music can be a factor. And to make it even more complicated, some days I prefer one tube and on other days, I prefer another. lol 
  
 I strongly recommend the Tung-Sol 5687WA. It is as good as my Sylvania's, but it is different. And I suggest that those of you with bright headphones may well find this tube to be exceptional.
  
 I also have Raytheon and Sylvania 5687's on the way. Searching Google, the lack of information regarding 7044's suggest that they don't get much love, so will likely skip that tube. However, the 7119/E182CC looks very interesting.
  
 Cheers


----------



## Nic Rhodes

a nice low distortion tube the 5687, like the 6SN7 in that regard.


----------



## gibosi

Also, I should point out, the 5687 has a heater current draw of .9A in the 6.3V mode. And therefore, you will need an external heater PS that can supply at least 1.0A.  However, 1.5A or more would be optimal. The 7119/E182CC has a heater current draw of .64A in the 6.3V mode, about the same as a 6SN7, so a 1.0A PS would be fine.


----------



## gibosi

A 1959 Raytheon 5687WA arrived today. I should note that, as usual, rebranding was the norm, and not the exception, so it is necessary to pay attention to construction details, otherwise, you may well end up with several tubes, all made by the same manufacturer (Tung-Sol in this case), but bearing different brands.
  
 While the plates and micas appear to very similar, the Raytheon has steel grid posts compared to copper for the Tung-Sol. Also, note the metal details on top of the upper mica are different. And further, the shape of the bottle is different. The Tung-Sol is slighted pinched at the base and has a more rounded top.
  
 I typically try to purchase tubes manufactured in the 1940's and 50's and accordingly, expect to see the older style getters. So I was surprised to see the big round getter on the Raytheon given that it was manufactured in 1959.
  
 I just rolled it into my amp and it lights up and plays. Both the Raytheon and the Tung-Sol came in their original boxes and tested new, so I will let this tube burn in for a while.


----------



## mordy

Hi Gibosi,
  
 From the little reading I did on the 5687 tube, it seems that the best sounding ones are the Tung Sol and Raytheon tubes with preference given to the earlier ones.


----------



## gibosi

mordy said:


> Hi Gibosi,
> 
> From the little reading I did on the 5687 tube, it seems that the best sounding ones are the Tung Sol and Raytheon tubes with preference given to the earlier ones.


 
  
 Yeah, we have probably read the same postings. Plus I have read that some consider the gold-pin Sylvania's among the best as well. Found a single and it's on it's way to me now.
  
 It is my impression that most of the amps that use this tube use pairs of them, some even two and three pairs, so singles are often pretty cheap. Good for me.


----------



## Nic Rhodes

I like the Tung Sol 5687WAs.


----------



## mordy

_I have read that some consider the gold-pin Sylvania's among the best as well._
  
 Way back in my 6AK5 days I tried some inexpensive JAN Sylvania 6AK5 tubes from the 60's and found that they sounded identical to the coveted Sylvania Gold Brand 6AK5 tubes (corroborated by others as well). IMHO the GB tubes and gold plating is just another marketing ploy.


----------



## gibosi

mordy said:


> _I have read that some consider the gold-pin Sylvania's among the best as well._
> 
> Way back in my 6AK5 days I tried some inexpensive JAN Sylvania 6AK5 tubes from the 60's and found that they sounded identical to the coveted Sylvania Gold Brand 6AK5 tubes (corroborated by others as well). IMHO the GB tubes and gold plating is just another marketing ploy.


 
  
 I think Mordy is absolutely correct. However, I think it is important to recognize that Gold Brand tubes are premium tubes. That is, back in the day, the military versions, in this case, the Sylvania 5687WA with extra support posts were not generally available to the consumer. Sylvania repackaged these military versions, complete with gold pins, and made them available to the public under the Gold Brand label. So while it was a marketing ploy, these tubes were Sylvania's best tubes. Today, with surplus military versions readily available, there is no reason to spend a premium for the Gold Brand versions. I am sure that except for the gold pins, there is no difference between a Sylvania 5687WA and a Sylvania GB5687. Personally, I like the gold pins as they do not easily corrode, and fortunately, I was able to get a single one for cheap, so I figured why not?


----------



## Nic Rhodes

You also had GE 5* and RCA Command tubes as similar ranges to Gold Brand Sylvanias.


----------



## bbmiller

mordy said:


> Hi,
> 
> Since I have a self imposed rule of not paying more than $8/tube perhaps I have a different way of shopping Ebay. The other day a pair of RCA(GE?) 6AS7 tubes went for less than $3 incl shipping (I missed the end of the auction), and I bought my one RCA 6AS7 tube for less than $3 incl shipping not long ago.
> 
> ...


 
How to win every auction on eBay - eBay Sniping video link


> From the videos author
> 
> *Uploaded on Aug 25, 2010*
> Click here for links ---------- (ATTENTION) Im already aware that the site is no longer called Goofbay.com like showed in the video but has a name change and now called Goofbid.com. Same site, same program, same idea


 
 I am wondering what you all think of this authors video and his suggestion of using the program mentioned which was called "Sniper" to automate your eBay bidding? Do you all have even better programs or techniques to successfully low bid on eBay?


----------



## 8bitBarry

OK Tube rolling I get. _There is distinct differences between the sound of valves in my Little Dot 1+_. I have been long aware they make sonic differences  since I began changing them in guitar amps 20 years ago... Opamp rolling?? I have no idea what anyone is going on about...
  
 I have tested four different opamps over the last week with a set of *Mullard CV4010*'s on my Little Dot 1+ using a basic home test of analysis software, audio test tones and my own collection of 'reference tunes'  and I am *99% sure they make no difference at all*.
  
 This is where I stand on my chair for you all to throw mud at me, but I can literally hear no differences in sound stage, dimension or anything that others perceive. It seems like its the McGurk effect, our brain imagining additional sounds when bombarded with sensory information from songs we love. You want to hear the differences. Even the obvious claims people make, 'better bass' 'faster' 'more 3D' etc have had no bearing on these devices that I have audibly tested whatsoever.
  
*Now because this thread is full of audiophiles whose knowledge I respect, whats your verdict? I would be interested to read them.*
  
*Or can anyone at least point me towards more enjoyable reading?*
  
 Thanks in advance as always...
  
 8bit


----------



## TrollDragon

bbmiller said:


> How to win every auction on eBay - eBay Sniping video link
> 
> 
> I am wondering what you all think of this authors video and his suggestion of using the program mentioned which was called "Sniper" to automate your eBay bidding? Do you all have even better programs or techniques to successfully low bid on eBay?


Let me share my experience with sniping software... We had sold a hand inlaid wooden cribbage board on ebay one time, included with this board was a Crane manual on cribbage. Not knowing vintage crib boards we just assumed it was a crane model and advertised the auction has such. A few of the bidders had noticed that it actually was not a crane, so we updated the description sent messages to all current bidders and the auction ran its course getting up over $100.

We shipped the board to the winning bidder and after he received it, he immediately filed a claim with Paypal and Ebay about how he was ripped off, product misrepresentation on our part and the like.

Much hassle and many emails later with Paypal and Ebay defending our position, we come to find out that this clown was using sniping software that didn't notify him of the description change.

So I have absolutely no use for sniping software or the people that use it...


----------



## gibosi

8bitbarry said:


> OK Tube rolling I get. _There is distinct differences between the sound of valves in my Little Dot 1+_. I have been long aware they make sonic differences  since I began changing them in guitar amps 20 years ago... Opamp rolling?? I have no idea what anyone is going on about...
> 
> I have tested four different opamps over the last week with a set of *Mullard CV4010*'s on my Little Dot 1+ using a basic home test of analysis software, audio test tones and my own collection of 'reference tunes'  and I am *99% sure they make no difference at all*.
> 
> ...


 
  
 We all have different ears and gear..... I found the difference in op amps to be quite noticeable. But again, this is me, my ears and my gear. As always YMMV.


----------



## TrollDragon

8bitbarry said:


> I have tested four different opamps over the last week with a set of *Mullard CV4010*'s on my Little Dot 1+ using a basic home test of analysis software, audio test tones and my own collection of 'reference tunes'  and I am *99% sure they make no difference at all*.


 
 I have tested a few op amps in various amplifiers...

 The ones I like best are the TI LME49720HA metal cans, if those don't fit then its the LME49860NA's I usually go to as the difference is minor between those two opamps. No if you are looking for an opamp that will allow you to "hear" a difference then you need to try an AD8620 opamp in your gear. To me it is like listening to a TI DAC then switching over to an ESS DAC chip... I find the AD8620 to be very clean and sterile just like the ESS DAC's.


----------



## bbmiller

trolldragon said:


> bbmiller said:
> 
> 
> > How to win every auction on eBay - eBay Sniping video link
> ...


 
 So should the lesson be only used sniping software responsibly by setting it up shortly before the conclusion of an auction?


----------



## TrollDragon

bbmiller said:


> So should the lesson be only used sniping software responsibly by setting it up shortly before the conclusion of an auction?


Or better yet not at all...


----------



## mordy

Hi bb,
  
 If I understand correctly, the whole concept of sniping is setting up a maximum bid and letting the sniper program do the rest automatically so that you don't have to stay up til 4 in the morning when the auction ends.
  
 I haven't used any sniper programs, but it seems to me that I lost several bids because of people using them and winning with just a few cents more than my bid.
  
 Despite TD's misgivings, I am thinking of using a sniper system. If I do, I will report back if and how it works.


----------



## gibosi

In the end, the highest bid wins. So it doesn't really matter if someone uses a sniping program if their bid is lower than yours. When I make my bid, I calculate my true maximum. That is, that amount such that if someone outbids me, I will have no regrets. Again, if someone else wants it more than I do, and is willing to pay more, it's their's.  And I know that if I am patient, another opportunity will eventually come along.


----------



## Acapella11

Hey, the LD thread has had an amazing progress and I haven't been on here for ages. I am not exactly on the DYI side of things, so I have just a plain question: In my LD is still the yugoslavian 6HM5, which I really appreciate for its neutrality and transparency. My only criticism is that the stage is not as wide as I it should be for my ears.
 Has anyone of you been listening to a tube that is very neutral and transparent but with a reasonably wide stage to replace my 6HM5s?


----------



## gibosi

acapella11 said:


> Hey, the LD thread has had an amazing progress and I haven't been on here for ages. I am not exactly on the DYI side of things, so I have just a plain question: In my LD is still the yugoslavian 6HM5, which I really appreciate for its neutrality and transparency. My only criticism is that the stage is not as wide as I it should be for my ears.
> Has anyone of you been listening to a tube that is very neutral and transparent but with a reasonably wide stage to replace my 6HM5s?


 
  
 Long time no see! 
  
 For those not wanting to mess with external sockets, power supplies and so forth, a pair of C3g's with adapters are several orders of magnitude better than your 6HM5. And in fact, a pair of these are as good or better than the best double triodes we have found to date. This post should answer most of your questions:
  
 http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/6000#post_10512665


----------



## Acapella11

Indeed  Thank you for this. Very useful.


----------



## i luvmusic 2

How is it possible that a $40 US shipping to Canada will take this long(4 days since the last tracking)and i paid the same amount from CHINA to Canada it took 2 DAYS WHAT.......


----------



## mordy

Hi Acapella 11,
  
 Welcome back! Good to hear from you!


----------



## hypnos1

acapella11 said:


> Hey, the LD thread has had an amazing progress and I haven't been on here for ages. I am not exactly on the DYI side of things, so I have just a plain question: In my LD is still the yugoslavian 6HM5, which I really appreciate for its neutrality and transparency. My only criticism is that the stage is not as wide as I it should be for my ears.
> Has anyone of you been listening to a tube that is very neutral and transparent but with a reasonably wide stage to replace my 6HM5s?


 
  
 Hey A11...we'd given you up for lost! Good to see you back.
  
 My goodness, things certainly have come a long way from the good work you were doing - which seems an even LONGER while ago, lol.
  
 As gibosi has said, the C3g(S) turned out to be a real find, and which I have plugged ad nauseam!
 Luckily for the MKIV, we don't need the extenders... the brass bits all come off easily, et voilà.
  
 If you decide to go for them, I posted some while ago how to free them from their metal prison!
  
 And then, perhaps, you might try a bit of (fairly) easy DIY and be treated to an equal leap by using 6as7g's as power tubes...I think you would hardly believe the end result... And if not the latter, the easier 6SN7 as powers surpass even the 6N30P-DR.
  
 In other words, mon ami, you have a lot of catching up to do!...
  
 Once again, it's good to see you back...
  
 HAPPY RENEWED ROLLING!!


----------



## MIKELAP

acapella11 said:


> Hey, the LD thread has had an amazing progress and I haven't been on here for ages. I am not exactly on the DYI side of things, so I have just a plain question: In my LD is still the yugoslavian 6HM5, which I really appreciate for its neutrality and transparency. My only criticism is that the stage is not as wide as I it should be for my ears.
> Has anyone of you been listening to a tube that is very neutral and transparent but with a reasonably wide stage to replace my 6HM5s?


 
 Hey guy welcome back .


----------



## mordy

Hi Gibosi,
  
_"However, the 7119/E182CC looks very interesting._"
  
 How about the Bendix MU 6900 tube?
  
  
 http://www.ebay.com/itm/NOS-PR-RARE-BENDIX-TYPE-6900-similar-to-7044-7119-5687-TUBES-/141353404782?pt=Vintage_Electronics_R2&hash=item20e951c96e
  
 For $715.00 you can have this pair right now LOL.
  
 Here is an eye opening article about the fabled Bendix Red Bank tubes - the highest quality tubes ever manufactured (until Eltrog http://www.audionote.com.au/NEW_-_Elrog_Tubes.html came along), LOL again.
 The article is subtitled: *Gold Plated Myths and Snake Oil *.
  
 A fascinating item: The gold plating on the pins was intended for storage only, in order to avoid corrosion. These tubes were intended for war heads for the Cold War, and the gold plating was supposed to scrape off when the tubes were inserted into the war heads.
  
 In addition to describing the various Bendix tubes, the link also contains a discussion on the shelf life of tubes being stored, and concludes with a fascinating video explaining the psychology of high priced sellers of vacuum tubes (plus many other real life scenarios).
  
 I am still trying to digest and understand all the information contained in this multifaceted article. Not sure if I understand correctly, but it seems to me that the 6900 tube has to be operated at parameters that are not found in audio equipment, which makes it unsuited for audio applications. Maybe someone can help here in explaining what's going on.
  
 This read and video qualifies for three credits at VTU (Vacuum Tube University):
  
 http://www.timeelect.com/vacuum-tubes-tc-myths-and-snake-oil-marketing.html
  
 For extra credit, here is an article that debunks all them fancy tube testers, including the Amplitrex 1000:
  
 http://www.timeelect.com/vacuum-tubes-tc-the-lagacy-from-wwII.html
  
 Well, it seems to me that this article justifies my approach to evaluating tubes: If it sounds good, it is a good tube; never mind that it is a garden variety $2-5 tube and didn't cost $100+ each and wasn't hyped up by the cognoscenti.
  
  
 .


----------



## gibosi

Yeah, the price of 6900's is way out of my league and that tube isn't even on my radar. lol  Fortunately, 5687's are relatively cheap and very good.
  
 I received a Sylvania Gold Brand 5687 with gold pins today. Since it is a repackaged 5687WA, notice the upper mica is doubled and there are two extra support posts between the micas. As it has an O-getter, I am assuming 1960's, or even 1970's, but it was cheap, and I am pleased to report that it lights up and plays.
  
 I figure that if I like it well enough, will try to find a 1950's vintage 5687WA.


----------



## Acapella11

Thank you for your warm welcome.


----------



## i luvmusic 2

Hi,
    Anyone have tried 6DN7 with LD's?THANKS!


----------



## gibosi

i luvmusic 2 said:


> Anyone have tried 6DN7 with LD's?THANKS!


 
  
 While the 6DN7 is a double triode, the two triodes are not identical. One is designed to be an oscillator and the other an amplifier. So while you could probably use it, it may well sound strange... lol


----------



## i luvmusic 2

gibosi said:


> i luvmusic 2 said:
> 
> 
> > Anyone have tried 6DN7 with LD's?THANKS!
> ...


 
 I saw them cheaper than 6SN7 so i thought they will be good for LD's.THANK YOU!


----------



## gibosi

While certainly not as cheap as 6DN7's, I am very impressed with 5687's. Further, these can also be used as power tubes in the LD II, III and IV. I have also seen a picture of a Single Power Audio One using a single 6SN7 as a driver and two 5687's as power tubes, so it's been done before.
  
 The easy way is to purchase two of these adapters:
  
 http://www.ebay.com/itm/290977041297?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649
  
 In fact, a number of folks here on head-fi have already tried these tubes in their LD's as power tubes, with positive results, and they even built their own adapters:
  
 http://www.head-fi.org/t/301219/review-of-the-diy-6h6n-to-e182cc-5687-tube-adapters-bullplugs-for-ld-mkii-mkiii-headphone-amplifiers
  
 Have fun!


----------



## i luvmusic 2

At this time i'am done making MOD's for LD's i have tonnes of work at home plus the CRACK on it's way so for now Baby steps for me.


----------



## MMMan

mmman said:


> Thank you for the greetings Mordy. I'm glad you are still so passionate about your sound.
> 
> I have a pair of GE 6cb6a tubes in my hand..... And a grab bag of 6485 s in the post, including 4 TS tubes, so I am ready to roll!! No short cuts here....
> 
> ...




Hi All,

Wow, this thread has been moving ahead faster than light!! It has been a fantastic journey for me to work through your adventures on my own.

I loved the step up to a fuller sound that came with the 6cbca and 6au6wa drivers. Cheap and wonderful expansion of range and dynamics. For the past week, I have been listening to a pair of 1967 GE 6ah6 6485 tubes.... My new fave drivers! Very realistic voices.... Deft worth a try!!

I have some IBM 1680 6be6 and some yugo 6hm5 (no car pics please!) on the way.... Followed closely by a bundle of adaptors, c3gs drivers and 6sn7 to try as power tubes 

Yes, I'm on the slow boat.... And enjoying every rose!!

Thank you all, once again.

Gordon


----------



## MIKELAP

mmman said:


> Hi All,
> 
> Wow, this thread has been moving ahead faster than light!! It has been a fantastic journey for me to work through your adventures on my own.
> 
> ...


 
 You've read the thread nice ,will spare you the car pics then lol


----------



## gibosi

5687
  
 I have three 5687's in my possession, a 1956 Tung-Sol 5687WA , a 1959 Raytheon 5687WA and a 1960-70 Sylvania GB5687 (5687WA). Last night I took some time to do some critical listening. However, I should note that I am not an "audiophile" as much as I am a "tube roller". lol  My critical listening skills are rather poor as are my ears, so at best, these are summary impressions.
  


Spoiler: Tung-Sol






  
 As I have mentioned before, the Tung-Sol 5687 is a somewhat dark tube with a "fruity and crunchy" mid range often associated with the Tung-Sol sound. The mids are fairly forward, with good body and fullness. The presentation is very liquid and very quiet, with exceptional transparency and mid-range detail. Bass is solid and detailed, but of the three 5687's the TS has the most subdued highs, not as airy as the Raytheon and Sylvania.
  


Spoiler: Raytheon






  
 The Raytheon has a fairly forward mid-range, like the Tung-Sol, but the highs are not as subdued, so the Raytheon comes across as a bit brighter than the Tung-Sol. While the presentation does not seem to be quite as liquid as the TS, this is still a very quiet and transparent tube, with very good detail and air. While the Tung-Sol might match up better with brighter headphones, the Raytheon might be a better fit for darker headphones. Otherwise, I would say that these sound very similar, and both are very good.
  


Spoiler: Sylvania






  
 As is typical of Sylvania tubes, I find the mid-range to be a bit subdued compared to the Tung Sol and Raytheon. I was able to make a quick comparison with the Sylvania 7963 and I could not reliably tell which tube I was listening to. And as I suspect that not many have heard the 7963, I should note that the 7963 is very similar to the 1940's Sylvania 6SN7W. So airy highs, silky smooth midrange and great bass. I guess you can tell that this is my favorite of the three 5687's lol.
  
 But that said, all of these are very good tubes and I strongly recommend any and all of them to you.


----------



## MMMan

Well, I finally caught up on my reading from post one to post 6952 this morning ( it's early Sunday morning here in Australia!). Fantastic (and relatively expensive) read!! Once again, thank you all for sharing.

I have an LD Mk IV, and it sounds fantastic!! A great buy.... And such a pleasure to try so many different tubes!!

So, here's my first question to the list: as you go up in costs for tube pre-amps, you appear to get more complex and separate circuits for L and R channels. Also, as you mix driver and power tubes, you tend to optimise combinations for detail and treble or bass/warmth/punch. I listen mostly through my speakers, which are bi-amped with two small t-amps. With the recent drift in this thread towards 6080s and 6as7s I'm thinking about buying an LD mk 9 and bi-preamping(start the signal split at the pre-amp stage, with each pre going to its own amp). Then I could Optimise the mk 9 for bass/warmth and optimise the mk IV for detail with different tube sets. I wonder how it would sound when the signals 'came back together' at the speakers? Thoughts?


----------



## TrollDragon

That would be a really fun setup to play with!

My computer 2.1 desktop system is bi-amped, nothing I built just a Corsair 250 watt package.


----------



## MMMan

Thought you might like it TD. BTW, love your crazy mad modding skills.... esp the headphone stands!! Plus other more complex things too....

G


----------



## TrollDragon

Thanks! Much Appreciated!
Your not on Instagram by any chance are you?


----------



## mordy

Hi MMMan and Gibosi et al,
  
 I wouldn't say that I am passionate about my sound, but rather that I am trying to be objective (even though I have old ears that have lost some of the ability to hear the upper treble according to a hearing test I took). Luckily, most of the recorded music resides in the lower and middle frequencies. By listening critically for a number of years it is possible to distinguish between different sounding tubes fairly easily.
  
 When the differences are smaller, it takes longer to crystallize out what the differences and personal preferences are, but it can definitively be done. One of the surprises to me on this forum is that we are able to agree that certain tubes are much better than others. Because of people being different, the equipment being different, the musical taste being different etc. etc., the ranking order of the best sounding tubes may differ from person to person, but we can definitively reach a consensus on a group of outstanding tubes.
  
 I would never say that such and such a tube is the best there is, but there is no doubt in my mind that the 6SN7, 6080 and 6AS7 tubes when used as power tubes are superior to the highly touted 6H30-DR "super tubes."
  
 As far as driver tubes go, one of the best of the EF95 family is the Ei 6HM5 tube.However,  based on personal experience and the judgment of people I trust, there are much better sounding tubes out there. In the top tier are the C3g tubes, the subminiature 6832 and 7963 tubes, as well as some 6SL7 and 6SN7 tubes, and now the 5687 tube (have one coming).
  
 Synergy: At the present time I am using my Little Dot Meiin9 which is a LD MKIII with the tube complement of the Little Dot MK9 (2x6080 + 6SL7). I have tried several different driver tubes, but so far the best are a 6SL7 and the 6832.
  
 Objectively, I think that this combination of tubes is better sounding than the OEM tube complement with a huge margin.
  
 Regarding the suggestion to use two LD amps to bi-amp speakers, I have mixed feelings. The only real way to find out is to try it. However, I do feel that the LD amp in a sense fulfills the biamp function with the power tubes effecting the lower frequencies especially, and the driver tubes taking care of the presentation of the mid and higher frequencies. Think of the power tubes as the rhythm section, and the driver tubes as the front line in a band. This applies to such powerful tubes as the 1.5A and 2.5A power tubes.
  
 Here is a tune to illustrate what I mean. It is a high quality New Orleans Jazz recording from 1965 called "Introduction Blues" where each band member is introduced separately. The piano, string bass, banjo and drums represent the rhythm section; tp, as, cl, tb the front line (power vs driver). You can use this recording to check your soundstage and imaging. (I have resigned myself a long time ago that few people share my musical taste. If u don't like it, just switch it off, but regardless, this recording can highlight some of your system's abilities.)
  
  
 https://www.youtube.com/watch?v=i4H9320KsqI
  
  
 One last item: Did someone compare the 5687 as a power tube to the 6AS7?


----------



## gibosi

mmman said:


> So, here's my first question to the list: as you go up in costs for tube pre-amps, you appear to get more complex and separate circuits for L and R channels. Also, as you mix driver and power tubes, you tend to optimise combinations for detail and treble or bass/warmth/punch. I listen mostly through my speakers, which are bi-amped with two small t-amps. With the recent drift in this thread towards 6080s and 6as7s I'm thinking about buying an LD mk 9 and bi-preamping(start the signal split at the pre-amp stage, with each pre going to its own amp). Then I could Optimise the mk 9 for bass/warmth and optimise the mk IV for detail with different tube sets. I wonder how it would sound when the signals 'came back together' at the speakers? Thoughts?


 
  
 Given the price of a LD mk9, I personally don't think it would be worth it....  
  
 I have a 4-speaker system: two satellites and two subwoofers (that I haven't listened to in ages). Out of the preamp, I have an electronic crossover which in turn feeds two stereo power amps, one for the satellites and one for the subwoofers. The crossover point is 100 Hertz. Unless the crossover point is substantially much higher in your system, dedicating a preamp to handle a frequency range of 20 to 100 Hertz, or so, would be a real waste of money, and further, would make your system unnecessarily complicated with no discernible benefit. I strongly suspect that if you install 6AS7's or 6080's in your IV, the bass would likely be indistinguishable from that of a MK 9.
  
 But anyway, as usual, my opinion is exactly worth the price you paid. 
  
 Cheers


----------



## MMMan

trolldragon said:


> Thanks! Much Appreciated!
> Your not on Instagram by any chance are you?


 
  
 No, I'm not on Instagram... unless the pictures are REALLY great looking, in which case that might be me!!
  
 Best
  
 G


----------



## MMMan

> snip... snip... snip
> 
> Here is a tune to illustrate what I mean. It is a high quality New Orleans Jazz recording from 1965 called "Introduction Blues" where each band member is introduced separately. The piano, string bass, banjo and drums represent the rhythm section; tp, as, cl, tb the front line (power vs driver). You can use this recording to check your soundstage and imaging. (I have resigned myself a long time ago that few people share my musical taste. If u don't like it, just switch it off, but regardless, this recording can highlight some of your system's abilities.)


 
  
Hi Mordy,
  
Interesting analogy.. but your musicians are playing in parallel. The physical sound characteristics of the tuba (more jazz bands should have tubas!!) does not depend on what the trumpet player blew!
  
Output of the power tube IS directly influenced by the output of the driver tube. The power tube cannot recover detail that is not passed to it by the driver... so everything I have read on here suggests that different combinations tend to influence either the higher end or the lower end. Do any combinations do a fantastic job of both? 
  
Best,
  
M


----------



## MMMan

gibosi said:


> Given the price of a LD mk9, I personally don't think it would be worth it....
> 
> I have a 4-speaker system: two satellites and two subwoofers (that I haven't listened to in ages). Out of the preamp, I have an electronic crossover which in turn feeds two stereo power amps, one for the satellites and one for the subwoofers. The crossover point is 100 Hertz. Unless the crossover point is substantially much higher in your system, dedicating a preamp to handle a frequency range of 20 to 100 Hertz, or so, would be a real waste of money, and further, would make your system unnecessarily complicated with no discernible benefit. I strongly suspect that if you install 6AS7's or 6080's in your IV, the bass would likely be indistinguishable from that of a MK 9.
> 
> ...


 
  
 Interesting setup. I was thinking of a crossover more in the range of 1,500 Hz, but not an absolute active filtered crossover. Relying more on the passive crossover within my bi-amped speaker.
  
 I agree that modded Mk IVs likely sound identical to the Mk 9 with regards to bass, and probably 'fullness', which I see as coming from lower-mids. I'm going to try some 6SN7s first, but I still may do it.
  
 Best,
  
 G


----------



## gibosi

Generally speaking, it is best to set the crossover point as low as possible. Middle C is about 262 Hertz. The top note on the piano is about 4000 Hertz. 1500 Hertz is roughly in the middle of what is generally considered to be the midrange. A crossover inevitably adds some distortion as you roll-off from one speaker driver to the other. And you may very likely be able to hear that transition at 1500 Hertz. Almost every instrument will be affected. At the very least, it is best to stay below the midrange.
  
 Fundamentals are red, yellow are harmonics


----------



## mordy

Hi MMMan,
  
_"Output of the power tube IS directly influenced by the output of the driver tube. The power tube cannot recover detail that is not passed to it by the driver... so everything I have read on here suggests that different combinations tend to influence either the higher end or the lower end. Do any combinations do a fantastic job of both?"_
  
 I am not sure if I understand what you are saying here. IMHO different power tubes extract more detail and bass than others. As an example, the RCA 6AS7 bring out more micro details than the RCA 6080 tubes I have. In previous comparison tests, the different versions of the 6N6P variants (6N6P, 6N6P-i, 6N6P-IR and 6H30-DR) mainly differed in the bass punch delivery. In other words, using the same driver, all these power tubes will make the sound different, some in details and some in bass, and some in both. Other areas where there was a difference was quickness and timbre.
  
 Perhaps some power tubes recover more detail from the driver tubes than others. I think I read about the GEC 6AS7 tubes that "they add an additional layer of detail to the sound." By way of analogy, a sensitive radio receiver would pick up more stations than one less sensitive. The signals are all there, but not every receiver is able to pick all of them up.
  
 I do feel that the tube combination I am using now does a fantastic job of all the ranges, bass, mid and high. IMHO there is definitively a synergy between driver and power tubes. It appears to me that my power tubes are somewhat dark, and the driver tube somewhat bright, and the combination works out very well.
  
 All of the above is based on my subjective listening impressions, and hopefully not influenced by any hype and preconceived notions.


----------



## jamca

hypnos1 said:


> Update on the 6HM5s (Yugoslavia?!)...
> 
> Despite the blinding flashes still on start-up(!) - but with no obvious ill-effects after 50+hrs - these have definitely knocked the RCA 6DT6As off their perch. Initial reservations have been totally kicked into touch. I have now become an avid fan of really wide and deep soundstage, even though I thought it at first a rather less "intimate" sound. I love the 'airiness' and clarity these babies are putting out. And the range and 'cleanliness' of treble notes, coupled with extra instrument separation is truly a revelation. This separation probably also explains my initial doubts over bass response - what I thought may be a negative, ie less perceived 'slam', I now realise may be down to a much more subtle reproduction of different TYPES of lower frequency...ie a nice spread, rather than 'bunched', which at first can seem less weighty.  Perhaps these tubes are not for heavy head-banging - unless you turn that knob right up! Then again, I am a firm believer that less is more as far as bass is concerned - there are so many fine, detailed things going on in a really well-recorded piece of music that it is bordering on the criminal to overpower them indiscriminately...just my personal thoughts, that is...But despite my ramblings, please don't get the wrong impression - bass is lovely and rich from these tubes. Give 'em a try! And the beauty of these also is they are just "plug 'n play" (EF95).
> 
> Happy rolling.


 

 i just tried them and i could say that i totally agree with you...


----------



## MMMan

gibosi said:


> Generally speaking, it is best to set the crossover point as low as possible. Middle C is about 262 Hertz. The top note on the piano is about 4000 Hertz. 1500 Hertz is roughly in the middle of what is generally considered to be the midrange. A crossover inevitably adds some distortion as you roll-off from one speaker driver to the other. And you may very likely be able to hear that transition at 1500 Hertz. Almost every instrument will be affected. At the very least, it is best to stay below the midrange.
> 
> Fundamentals are red, yellow are harmonics
> 
> Snip....snip...




Hi Gibosi,

Cool chart... Thank you. 

I think the internal crossover for my speakers is 1500hz. Since I won't use an external active crossover, I will be crossing over at 1500hz based on the speakers design. Perhaps later I will get speakers than can cut out the internal crossover and I can input directly to the driver, but that's something for the future...

Best,

G


----------



## MMMan

mordy said:


> Hi MMMan,
> 
> _"Output of the power tube IS directly influenced by the output of the driver tube. The power tube cannot recover detail that is not passed to it by the driver... so everything I have read on here suggests that different combinations tend to influence either the higher end or the lower end. Do any combinations do a fantastic job of both?
> "_
> ...




Hi Mordy,

Sorry I didn't describe it very well. All I am suggesting is that perhaps one set of tubes optimised for high end detail plus another set of tubes optimised for very well defined mids and bass may perform better than a single set.

A tube is simply a signal processor with an emphasis on amplification. All are imperfect in the way they amplify our audio signals, but some of these imperfections sound nice. Other imperfections lead to information loss. Some tubes lose information in the high end and some lose information in the low end. We tend to compensate by matching a bright driver with a Bassy power tube, or vice versa. I want to see what happens if we match a bright driver with a bright power tube then compensate with a second system that matches a mid- oriented driver with a solid bass power tube. Just out of interest. If nothing good happens, I find the best overall tubes for the mk 9 and move the mv IV to my man-cave. Win-win...

But, I have some 6sn7s on the way.... And maybe they will convince me I don't need to try bi-preamping.

Best,

G


----------



## hypnos1

jamca said:


> i just tried them and i could say that i totally agree with you...


 
  
 Hi jamca.
  
 Nice to see another convert to LD land...WELL DONE!
  
 And thanks for reminding me of where the _real _magic began, lol!...I'm so glad you agree about the 6HM5 - a truly amazing tube, given straight plug 'n play and dirt cheap...BUT..."you ain't seen nothin' yet!". I can only hope you have the funds & fairly simple DIY skills to experience an even greater leap - to where we are now, ie C3g drivers and 6AS7G/6080 powers (or other combos a la gibosi and mordy, if you're not quite so into "nice 'n neat" as I am!)...Plus, of course, depending on the model you possess...
  
 What I stated in the post you quoted mirrors _precisely_ the qualities of the combo I mentioned -  as I have described (too?!) many times - but TWOFOLD!!
  
 So, perhaps, your journey is not yet over? 
	

	
	
		
		

		
		
	


	



  
 Cheers.
  


mmman said:


> Hi Mordy,
> 
> Sorry I didn't describe it very well. All I am suggesting is that perhaps one set of tubes optimised for high end detail plus another set of tubes optimised for very well defined mids and bass may perform better than a single set.
> 
> ...


 
  
 Hi MMMan.
  
 I must admit your idea _sounds_ interesting, but methinks gibosi's doubts have a solid ring about them, lol!
  
 Then again, nothing ventured....!! ...And if nothing is lost, better still.
  
 6SN7s?... Much more convincing would be the 6AS7Gs/6080s - of that I am quite sure. And even MORE convincing could possibly be the 5998...shame the price has gone ballistic (despite my horror at such $$$, I am increasingly tempted to raid the savings and see if the gains generally found can also be replicated in our humble LDs - yet another sign of early-onset dementia...does anyone think they might just surpass the Chatham 6AS7Gs enough to warrant a near heart-attack?!)...


----------



## gibosi

> Originally Posted by *hypnos1* /img/forum/go_quote.gif
> 
> Then again, nothing ventured....!! ...And if nothing is lost, better still.
> 
> 6SN7s?... Much more convincing would be the 6AS7Gs/6080s - of that I am quite sure. And even MORE convincing could possibly be the 5998...shame the price has gone ballistic (despite my horror at such $$$, I am increasingly tempted to raid the savings and see if the gains generally found can also be replicated in our humble LDs - yet another sign of early-onset dementia...does anyone think they might just surpass the Chatham 6AS7Gs enough to warrant a near heart-attack?!)...


 
  
 It is my understanding that a 5998 requires a different cathode resistance than the 6AS7 in order to really shine. That said, lots of folks have put 5998's into amps designed for the 6AS7 and believe they are an improvement. As the LD was not designed to run 6AS7's, it is just really, really tough to predict how they will sound.....
  
 But "Then again, nothing ventured....!! ...And if nothing is lost, better still."
  
 And for sure, if they are not a significant improvement, you could likely resell them for what you paid... so nothing lost....
  
 So I say, 'Go for it!" lol


----------



## mordy

TEST YOUR KNOWLEDGE: What is this? (Hint: this tube is 20" tall)


----------



## genclaymore

I can imaging some one trying to mod that to work on their little dot and blowing there ear's off there head.   Look like something that was used in radio or some kind of old machine. could make the world largest Tube amp with that.


----------



## hypnos1

mordy said:


> Hi MMMan,
> 
> _"Output of the power tube IS directly influenced by the output of the driver tube. The power tube cannot recover detail that is not passed to it by the driver... so everything I have read on here suggests that different combinations tend to influence either the higher end or the lower end. Do any combinations do a fantastic job of both?"_
> 
> ...


 
  
 Hi mordy.
  
 Considering your "less-than-perfect" ears, lol, you (like gibosi) come up with some pretty darned good assessments of what is entering them! Keep it up...
  
 Yes, indeed, this thread is now showing there is much more to the power tube than the generally regarded "simply a signal processor with an emphasis on amplification" (thanks/sorry MMMan!). Against all logic, _something_ else is going on that defies objective quantification/explanation, methinks...The same (but even more so) goes for the external power supplies we are using for our 'super' power tubes' heaters...as you have previously commented on. I recently mentioned I was replacing my laptop-power-supply-like 12V 6A unit with a "fancy", medical grade 12V 10A supply. Well, as it arrived from Israel with 2 loose components in the bag! (I did at least get a full refund), I went for a 12V 15A transformer power supply - made in China, of course - which I got from a UK seller for £9, incl shipping! (and about $16-$20 from either China, HK or within the USA). I have to admit it looks VERY well made for such silly money - just as good as aforementioned 'special' unit, in fact.
  
 Anyway, even though my previous 6A supply had power to spare, and should have been perfectly good enough for the 5A 6AS7Gs' draw (and thereby negating TD's concerns re sufficient power to get the best out of the tubes), I could swear this new unit is giving a bit more weight to the lower frequencies. I have tried SO hard to avoid any possible placebo effect, but I still feel there is just "that bit more". Once again, logic/technical reasoning should discount these findings - being just the heater supply, and not the plates' - ...BUT!!
  
 Ah well, who knows?!
  
 As an aside, even after a couple of hours this unit gets just slightly warm - no need whatsoever for a fan...NICE! I am really pleased with it...so far, at least...
  
  
  


gibosi said:


> It is my understanding that a 5998 requires a different cathode resistance than the 6AS7 in order to really shine. That said, lots of folks have put 5998's into amps designed for the 6AS7 and believe they are an improvement. As the LD was not designed to run 6AS7's, it is just really, really tough to predict how they will sound.....
> 
> But "Then again, nothing ventured....!! ...And if nothing is lost, better still."
> 
> ...


 
  
 Aw gee, g, I didn't think you'd be tempting me to bankruptcy lol! (But I kinda like it!!).
  
 Must admit I am _slightly_ concerned that it isn't a _straight_ replacement for the 6AS7G...if the cathode resistor needs to be GREATER, then it's surely a no-go...must research a bit more...
	

	
	
		
		

		
		
	


	



  
 Cheers.


----------



## Nic Rhodes

VC 1257? Hydopgen Thyratron. Tung Sol / Chatham made them I think and it is not compatible with LDs!


----------



## gibosi

hypnos1 said:


> Must admit I am _slightly_ concerned that it isn't a _straight_ replacement for the 6AS7G...if the cathode resistor needs to be GREATER, then it's surely a no-go...must research a bit more...


 
  
 From this discussion:
  
 http://www.head-fi.org/t/600110/2359glenn-studio/735#post_8661420
  
 The cathode resister needs to be one-half the value of that used for a 6AS7. The objective is to run the plates at a higher current. However, I do not know what the proper value is for a 6AS7, nor do I know the value of the LD's stock cathode resister. Assuming that the LD's resister is about right for the 6AS7 (a rather risky assumption I think) and you decide to reduce that resistance by one half, then you have to determine if the transformer can supply the necessary extra current, and if so, can the LD circuitry handle the extra current.....


----------



## mordy

Well done, Nic! U get a 100 on the test! Here is the link:
  
 http://home.earthlink.net/~webdisk1/oddtubes/ChathamVC1257.htm
  
 This tube is filled with Hydrogen - I think that it has been evacuated for display purposes....
  
 Hypnos 1,
  
 If we can trust our ears, power supplies and power tubes do make a difference in the sound IMHO.
  
 On another note, my Tung Sol 5687 arrived. I followed Gibosi's recipe for connecting the tube to a 9pin 12AX7 breadboard. The tube lights up and I get sound, but there is a fairly loud hum in the left channel, and the tube seems somewhat microphonic. Any advice?
  
 First impression is that it sounds quite good with strong bass and treble, but the hum is distracting....


----------



## gibosi

mordy said:


> On another note, my Tung Sol 5687 arrived. I followed Gibosi's recipe for connecting the tube to a 9pin 12AX7 breadboard. The tube lights up and I get sound, but there is a fairly loud hum in the left channel, and the tube seems somewhat microphonic. Any advice?
> 
> First impression is that it sounds quite good with strong bass and treble, but the hum is distracting....


 
  
 I never had that problem, so have no good ideas about what might be causing it. Of course, rechecking your connections is a good idea, especially the left channel, corresponding to pins 6, 7 and 9, and make sure that your heater connection on pin 8 isn't inadvertently touching 7 or 9.
  
 Good luck!


----------



## hypnos1

gibosi said:


> From this discussion:
> 
> http://www.head-fi.org/t/600110/2359glenn-studio/735#post_8661420
> 
> The cathode resister needs to be one-half the value of that used for a 6AS7. The objective is to run the plates at a higher current. However, I do not know what the proper value is for a 6AS7, nor do I know the value of the LD's stock cathode resister. Assuming that the LD's resister is about right for the 6AS7 (a rather risky assumption I think) and you decide to reduce that resistance by one half, then you have to determine if the transformer can supply the necessary extra current, and if so, can the LD circuitry handle the extra current.....


 
  
 Thanks gibosi...looks like a LOT more research is needed!...Will have to be later, though.
  
 Cheers!


----------



## mordy

Hi Gibosi,
  
 Here is a spec sheet for the TS 5687.
  
_5687_ - Jogis Roehrenbude  
 By connecting pins 4 and 5 (skipping pin 8 and not tying together 4&5) to an external heater PS I could run this tube at 12.6V. Would there be any advantage in doing this?
  
 (I am still trying to correct the hum, mainly in the R channel - got a little bit better but not gone)


----------



## gibosi

mordy said:


> By connecting pins 4 and 5 (skipping pin 8 and not tying together 4&5) to an external heater PS I could run this tube at 12.6V. Would there be any advantage in doing this?
> 
> (I am still trying to correct the hum, mainly in the R channel - got a little bit better but not gone)


 
  
 Yeah, these tubes can be run at 12.6 volts just like a 12AX7. And just like 12AX7's, it doesn't make any difference - 6 of one, half-a-dozen of the other. 
  
 As the hum is getting better, it just may be that you have a NOS tube, and the hum will go away after burning in for a few hours.
  
 Cheers


----------



## mordy

I'll let the tube burn in and will recheck the humming - thanks.
  
 Something else that I don't understand: The 6080 power tubes have an amplification factor of 2, which means that I can turn up the volume on the LD amp all the way without any distortion.
  
 Normally, with my headphones, I leave the volume at 9 o'clock. With the 6080s, I need to run it a 12 o'clock. As mentioned, with speakers, I keep it all the way up.
  
 Now, when listening to the hum in the left channel, it keeps increasing with increasing volume levels, but at full volume the hum decreases - why?


----------



## gibosi

I'm trying to remember....  It's been a while since I had to deal with "new tube hum"....  But as best I can remember, with new tube hum, the level of the hum doesn't change with the volume setting. Further, checking the tube every couple hours during the burning-in process, the tube becomes noticeably quieter. So.... if the hum does't get better with time, you may well have a defective tube....


----------



## hypnos1

gibosi said:


> It is my understanding that a 5998 requires a different cathode resistance than the 6AS7 in order to really shine. That said, lots of folks have put 5998's into amps designed for the 6AS7 and believe they are an improvement. As the LD was not designed to run 6AS7's, it is just really, really tough to predict how they will sound.....
> 
> But "Then again, nothing ventured....!! ...And if nothing is lost, better still."
> 
> ...


 
  
 SAVINGS RAIDED!! (Have I finally lost the plot?).
  
 Hey, gibosi, methinks you just might have something to answer for, lol...especially if "She who must be obeyed" finds out how much I paid! 
	

	
	
		
		

		
			




  
 Well, I took your advice (sic) AND the plunge. But given the question mark over the 5998's requirements, I treated myself to an early Christmas present (or rather _another_ one!)...a pair of NOS British made CV2523s (6AS7G equivalent, as you know) which should be OK and which would appear to be at least as good as, if not better than, the 5998 (depending on ears, of course).
  
 The heart attack, thankfully, has been mediated by several factors :
  
 1. The 5998s, with customs and VAT, now come up to their price level (when they used to be MUCH cheaper).
 2. As you said, if not much different, I could always resell...hmmm...any _real_ chance of that happening?!
 3.Cheaper than a MK9/La Figaro/Glenn etc etc.
 4. If my poor LD does finally succumb to the torture, I could get _yet another_ Christmas present - a La Figaro 339, which I am sure _would_ say "thank you"!
  
 So, as you can see mon ami, I've done a fairly good job of convincing myself of my folly...and of absolving you of all blame (well, _nearly_ all!! 
	

	
	
		
		

		
		
	


	




 ). Now I just can't wait to get my sticky hands on 'em, and see if they really _do_ better the Chathams...


----------



## MIKELAP

hypnos1 said:


> SAVINGS RAIDED!! (Have I finally lost the plot?).
> 
> Hey, gibosi, methinks you just might have something to answer for, lol...especially if "She who must be obeyed" finds out how much I paid!
> 
> ...


 
 I guess youll hold on just a bit tighter to them when removing .the horror


----------



## Nic Rhodes

I hope the CV2523s are GECs. I have original military CV2523s labelled as Valve Electronic but are russian made but very similar boxes to the GEC also labelled by  Valves Electronic (and I broke the original seals) so are not later repacks.


----------



## mordy

Today I received a pair of Chatham JAN CAHG 6080WA tubes for $10 incl shipping.  This tube was manufactured in Sept 1960 - is this after Tung Sol took over Chatham? These used tubes light up and sound OK.
  

  

  

  
  
  
 After I bought them, the seller, a woman, asked me: "I am really curious why these tubes were viewed by shoppers over 896 times during the week they were listed. If you don't mind, please tell me a little more about them. I do hope you find them useful! Thank you again"
  
 What should I tell her? How come I was the single bidder?


----------



## TrollDragon

mordy said:


> After I bought them, the seller, a woman, asked me: "I am really curious why these tubes were viewed by shoppers over 896 times during the week they were listed. If you don't mind, please tell me a little more about them. I do hope you find them useful! Thank you again"
> 
> What should I tell her? How come I was the single bidder?


 
  
 Tell here those tubes are closely watched by Homeland Security and you are using them to build a small geothermal nuclear device, ask if she has any lithium-6 deuteride (_6Li2__H_) for sale...


----------



## hypnos1

mikelap said:


> I guess youll hold on just a bit tighter to them when removing .the horror


 
  
 You bet ya, M!
  


nic rhodes said:


> I hope the CV2523s are GECs. I have original military CV2523s labelled as Valve Electronic but are russian made but very similar boxes to the GEC also labelled by  Valves Electronic (and I broke the original seals) so are not later repacks.


 
  
 Hi Nic...you tryin' to give me _another _heart attack lol?! They were listed as Mullards, and I know 'their' 6AS7Gs were in fact Russians...but hopefully these are the real deal - they certainly look it, from the photos...any comments? :
  

  

  
 They look pretty Kosher to me...fingers crossed (listed as made in UK so if not, they go straight back!).


----------



## mordy

Hi TD,
  
 Did u know that Chatham Electronics started out building Geiger counters in the late 40's - early 50's? I have tried to find information on this company, but there are so far very few references that I have found.
 Does anybody have a reference to the history of Chatham?


----------



## i luvmusic 2

mordy said:


> Today I received a pair of Chatham JAN CAHG 6080WA tubes for $10 incl shipping.  This tube was manufactured in Sept 1960 - is this after Tung Sol took over Chatham? These used tubes light up and sound OK.
> 
> 
> 
> ...


 
 Because i was too busy checking my BH CRACK Kit parts  don't have time to do some ebay shopping 
	

	
	
		
		

		
		
	


	




BTW i purchased two of that and one of them does not work i punch a hole insert a LED and sold it for $15 to my Boss son.


----------



## gibosi

hypnos1 said:


> Hey, gibosi, methinks you just might have something to answer for, lol...especially if "She who must be obeyed" finds out how much I paid!
> 
> 
> 
> ...


 
  
 Wow! A pair of NOS CV2523! Wow! But yes, I agree, for the same cost there is significantly less risk in going with these versus 5998. But wow!


----------



## gibosi

mordy said:


> After I bought them, the seller, a woman, asked me: "I am really curious why these tubes were viewed by shoppers over 896 times during the week they were listed. If you don't mind, please tell me a little more about them. I do hope you find them useful! Thank you again"
> 
> What should I tell her? How come I was the single bidder?


 
  
 Well, this is just a WAG on my part, but perhaps "Chatham" is the reason. Given that Chatham 6AS7G and Chatham 5598 are much sought after, people saw "Chatham" in the listing title and decided to check to verify what they were. But again, just a WAG on my part.


----------



## mordy

Here are my thoughts why so many looked and nobody bid: This offer was advertised with too many caveats - look at his:
  
Lot of 2 JAN-CAHG-6080WA Chatham Electronics Vacuum Tubes UNTESTED No Boxes  
 “UNTESTED I have no way to guarantee that these work. They are shiny but out of their boxes.”
  
  
 Two out-of-the boxes vacuum tubes JAN-CAHG-6080WA Chatham Electronics. They look shiny but I do not know if they work or not. They came from a large box of mixed loose and boxed tubes.
  
 So here we have somebody who is selling off tubes from an estate or some such, cannot test them, and don't know if they work or not. I assume that these factors scared away potential buyers.
  
 On the other hand, why would somebody hold on to junk for over 50 years? Took a chance; my experience has been that almost all tubes work that I bought, and the most of the ones that did not work had broken in transit.
  
 Gibosi - your wild guess (had to look up WAG in the slang dictionary - has a different meaning in the UK though) is probably right on.


----------



## bbmiller

hypnos1 said:


> gibosi said:
> 
> 
> > From this discussion:
> ...


 
 Is cathode resistance the same as bias? When you see headphone tube amps advertised as having automatic or adjustable bias is that what they're talking about? Automatically or manually adjusting the cathode resistance?


----------



## kvtaco17

mordy said:


> Here are my thoughts why so many looked and nobody bid: This offer was advertised with too many caveats - look at his:
> 
> Lot of 2 JAN-CAHG-6080WA Chatham Electronics Vacuum Tubes UNTESTED No Boxes
> “UNTESTED I have no way to guarantee that these work. They are shiny but out of their boxes.”
> ...


 

 Those are very good tubes... I have a matched pair and love them!


----------



## mordy

The tubes I got are from the same date so perhaps a matched pair. Emailed seller that the tubes lit up and work. Seller replied that I was brave to take a chance on them!
  
 The most expensive Chatham tubes are the Chatham/Bendix tubes with graphite plates - sometimes $400/pair. Read somewhere that these tubes were intended for military and missile use, and the specs are for missiles and not audio. Is it true that these tubes are not suited well for audio?
  
 The subminiature tubes work very well in audio applications, and they were also developed for missiles.


----------



## kvtaco17

mordy said:


> The tubes I got are from the same date so perhaps a matched pair. Emailed seller that the tubes lit up and work. Seller replied that I was brave to take a chance on them!
> 
> The most expensive Chatham tubes are the Chatham/Bendix tubes with graphite plates - sometimes $400/pair. Read somewhere that these tubes were intended for military and missile use, and the specs are for missiles and not audio. Is it true that these tubes are not suited well for audio?
> 
> The subminiature tubes work very well in audio applications, and they were also developed for missiles.


 

 I have a few pair of amazing Chatham/Tung-Sol 6336, graphite plates with copper posts... Truly sublime with anything low impedance in my Glenn amp... maybe after my C3G's get here and I get bored I'll try to adapt them since I have 2 matched pairs...


----------



## gibosi

I think you are talking about the Bendix 6900..... It is my understanding that they are fine for audio, but it is necessary to bias them quite differently than the 5687 and 7119. As most amps are not configured to properly bias these tubes, some incorrectly assume that they are not suitable for audio. (And I don't think the LD can properly bias these tubes either.... )
  
 Anyway, in today's mail I received an Heerlen-made Amperex 7119/E182CC, manufactured in 1962 (ID2 /Delta 2A1). I paid about $20, so much more affordable than a 6900 would be, lol, and I am pleased to be able to report that it lights up and plays.


----------



## gibosi

bbmiller said:


> Is cathode resistance the same as bias? When you see headphone tube amps advertised as having automatic or adjustable bias is that what they're talking about? Automatically or manually adjusting the cathode resistance?


 
  
 I think so...  but this is way beyond my knowledge and experience. Perhaps TrollDragon will read this and be able to tell us more.....


----------



## TrollDragon

gibosi said:


> I think so...  but this is way beyond my knowledge and experience. Perhaps TrollDragon will read this and be able to tell us more.....


 


bbmiller said:


> Is cathode resistance the same as bias? When you see headphone tube amps advertised as having automatic or adjustable bias is that what they're talking about? Automatically or manually adjusting the cathode resistance?


 
  
 These will best answer that question.
  
 Quote: Aiken Amplifiers What is Biasing Whitepaper.


> Preamp tubes are almost universally cathode biased, because they are used for signal amplification, not power amplification, and the side effects of cathode biasing are not as important.  Also, cathode biasing makes the circuit less dependent on tube parameters, and more forgiving with respect to bias point.  This allows replacement of tubes without having to rebias the amplifier stage.   Output tubes that are cathode-biased should always be checked when replacing tubes, however, because they vary widely in terms of idle current for a given cathode resistor value, and it may be necessary to change the cathode resistor value to return the output stage to it's proper bias current.


 
  
 He speaks of _preamp_ tubes and _output_ tubes, the LD is *only* a preamp in all regards.
  
 Also this info here from Ideal Innovations is a good read.
 http://www.idealinnovations.biz/biastubes.htm


----------



## hypnos1

gibosi said:


> Wow! A pair of NOS CV2523! Wow! But yes, I agree, for the same cost there is significantly less risk in going with these versus 5998. But wow!


 
  
 Thanks, gibosi, for helping to assuage my guilt lol!...and can only hope that it will indeed be WOW! once again - assuming they arrive intact!!. (Hope Nic - or anyone else -  can confirm all is well from the photos).
  


bbmiller said:


> Is cathode resistance the same as bias? When you see headphone tube amps advertised as having automatic or adjustable bias is that what they're talking about? Automatically or manually adjusting the cathode resistance?


 
  
 Hi bb.
  
 It seems using cathode resistors is _one_ way of setting bias...so I would assume _self_-bias is more correct - according to the resistor used, and thus only really altered by manually switching between different ones? As gibosi says, we need the likes of TD to chip in here?...


----------



## bbmiller

trolldragon said:


> Quote: Aiken Amplifiers What is Biasing Whitepaper.
> 
> 
> > Preamp tubes are almost universally cathode biased, because they are used for signal amplification, not power amplification, and the side effects of cathode biasing are not as important.  Also, cathode biasing makes the circuit less dependent on tube parameters, and more forgiving with respect to bias point.  This allows replacement of tubes without having to rebias the amplifier stage.   Output tubes that are cathode-biased should always be checked when replacing tubes, however, because they vary widely in terms of idle current for a given cathode resistor value, and it may be necessary to change the cathode resistor value to return the output stage to it's proper bias current.
> ...


 
 Thanks very much  TrollDragon! I think both those links in the above that I have re-quoted are very good. From those links it seems fixed biasing which those articles explain might be called the opposite of fixed biasing because a potentiometer is usually employed is not what the little dot amplifiers use. Since  as much work as the frequent posters to this thread have done with these amplifiers, it seems to me, that someone would have surely discovered such potentiometers if they were to exist. So it would seem to be probably a safe assumption that both driving tubes and power tubes in these amplifiers are cathode bias. Do you think I assume too much?
  
 I am also wondering with as much time as the good people who frequent post to this thread have spent modifying their little dot amplifiers if anyone has made a attempts however crude of creating a partial or full schematic from site? If so may we swear to not be judged mental as to the artistic merit of such a drawing and have this person share a picture of such schematic drawing with us?
  
 I recall spending much time both at the little dot company site and the rest of the World Wide Web looking for schematics of little dot amplifiers and being totally unsuccessful in finding such so I assume it doesn't exist and the only possible source of such a schematic, were they to exist, might be a member of this thread should such a drawing even exist?


----------



## MIKELAP

bbmiller said:


> Thanks very much  TrollDragon! I think both those links in the above that I have re-quoted are very good. From those links it seems fixed biasing which those articles explain might be called the opposite of fixed biasing because a potentiometer is usually employed is not what the little dot amplifiers use. Since  as much work as the frequent posters to this thread have done with these amplifiers, it seems to me, that someone would have surely discovered such potentiometers if they were to exist. So it would seem to be probably a safe assumption that both driving tubes and power tubes in these amplifiers are cathode bias. Do you think I assume too much?
> 
> I am also wondering with as much time as the good people who frequent post to this thread have spent modifying their little dot amplifiers if anyone has made a attempts however crude of creating a partial or full schematic from site? If so may we swear to not be judged mental as to the artistic merit of such a drawing and have this person share a picture of such schematic drawing with us?
> 
> I recall spending much time both at the little dot company site and the rest of the World Wide Web looking for schematics of little dot amplifiers and being totally unsuccessful in finding such so I assume it doesn't exist and the only possible source of such a schematic, were they to exist, might be a member of this thread should such a drawing even exist?


 
 Check this out maybe its what your looking for  looks to be a schematic of mk4 page 203 post 3033


----------



## bbmiller

mikelap said:


> bbmiller said:
> 
> 
> > Thanks very much  TrollDragon! I think both those links in the above that I have re-quoted are very good. From those links it seems fixed biasing which those articles explain might be called the opposite of fixed biasing because a potentiometer is usually employed is not what the little dot amplifiers use. Since  as much work as the frequent posters to this thread have done with these amplifiers, it seems to me, that someone would have surely discovered such potentiometers if they were to exist. So it would seem to be probably a safe assumption that both driving tubes and power tubes in these amplifiers are cathode bias. Do you think I assume too much?
> ...


 

 Yes that right thanks!


----------



## TrollDragon

bbmiller said:


> Yes that right thanks!


In this post there is the rest of the power supply section as well. I am not an electronics draftsman and the schematic was made by following the traces on the LD MK IV board.

http://www.head-fi.org/t/439449/little-dot-mk-iii-mods/135#post_10697668 

If you have the skill and wish to clean up the layout then please feel free to.


----------



## joshk4

Hi,
  
 I'm new to tube rolling, and was wondering if there are any differences to these two?
  
 http://www.ebay.com/itm/2x-Voshkod-6ZH1P-EV-Matched-Pair-Little-Dot-Amp-MKIII-MKIV-MKII-II-III-IV-I-/121241104213?_trksid=p2054897.l5658
  
 http://www.ebay.com/itm/MATCHED-PAIR-6J1P-EV-6ZH1P-EV-GOLD-GRID-Little-Dot-MKIII-MKIV-MKII-II-III-IV-I/141335108254?_trksid=p2047675.c100011.m1850&_trkparms=aid%3D222007%26algo%3DSIC.MBE%26ao%3D1%26asc%3D20140602152332%26meid%3D8771771165595592921%26pid%3D100011%26prg%3D20140602152332%26rk%3D3%26rkt%3D10%26sd%3D171386850249
  
 The price difference is quite a fair bit, and just wanted help on whether there is a difference.
  
 Thanks
 Josh


----------



## gibosi

joshk4 said:


> I'm new to tube rolling, and was wondering if there are any differences to these two?
> 
> http://www.ebay.com/itm/2x-Voshkod-6ZH1P-EV-Matched-Pair-Little-Dot-Amp-MKIII-MKIV-MKII-II-III-IV-I-/121241104213?_trksid=p2054897.l5658
> 
> ...


 
  
 They are the same, that is 6ZH1P-EV = 6J1P-EV.
  
 Purchasing matched pairs for the Little Dot is a waste of money. I purchased two pairs from this vendor:
  
 http://www.ebay.com/itm/2-pc-6J1P-EV-EF95-6F32-6AK7-Gold-Platinum-grid-NIB-/130436695928?
  
 $3 / pair, plus $12 shipping to the US.


----------



## TrollDragon

Yenaudio is a "Boutique" tube seller in the States and you will pay higher for any tubes from them.


----------



## mordy

Did anybody try the 6336 tubes as power tubes with the LD MKIII using an external PS? Would two 5A tubes work in the LD MKIII using external PS?


----------



## TrollDragon

Why on earth would you want a pair of tubes that would draw 10A of heater power.

It's like putting "Y" speed rated tires on a Yugo... It won't go any faster or drive any better even though the tires are rated for 300KMh... 

You would be better off changing out the Capacitors on the amplifier for better quality ones...


----------



## gibosi

mordy said:


> Did anybody try the 6336 tubes as power tubes with the LD MKIII using an external PS? Would two 5A tubes work in the LD MKIII using external PS?


 
  
 If anyone has done this they haven't said so publicly.... And while it would be a simple matter to provide 10A of heater current using an external PS, it is not at all clear how much current the cathode and plate require to operate. So there is the question of whether the LD can actually supply enough current to operate these tubes. And then there is the question of whether the circuit board inside the LD can handle that current without overheating or worse....
  
 I certainly don't know the answers to these questions....
  
 Again, this is uncharted territory... Of course, I would be very interested to hear the results if someone tries...  But I hope their LD doesn't go up in smoke....


----------



## kvtaco17

So now I've inherited an MK3... So many tube Amos so little time lol


----------



## kvtaco17

Amps lol


----------



## i luvmusic 2

So you guys are having fun with your LD's while in the meantime i'am  waiting for the Crack Transformer end bell to dry.I hate waiting


----------



## TrollDragon

i luvmusic 2 said:


> So you guys are having fun with your LD's while in the meantime i'am  waiting for the Crack Transformer end bell to dry.I hate waiting


Bake it in the oven!


----------



## i luvmusic 2

trolldragon said:


> i luvmusic 2 said:
> 
> 
> > So you guys are having fun with your LD's while in the meantime i'am  waiting for the Crack Transformer end bell to dry.I hate waiting
> ...


 
 No can't do my wife is here i was trying that but she's not happy baking Chems in her oven.


----------



## i luvmusic 2

For 12AU7 what is the advantage of connecting Pin 4 and Pin 5 to Positive and Pin 9 to Negative?Thanks!


----------



## TrollDragon

I really don't think it makes much difference as the tube filaments don't have a polarity. Is this on the Crack? Possibly a better routing of wires, maybe to keep noise down.


----------



## i luvmusic 2

trolldragon said:


> I really don't think it makes much difference as the tube filaments don't have a polarity. Is this on the Crack? possibly a better routing or wires, maybe to keep noise down.


 
 Yes and THANK YOU! I was just curious about that because i always connect 4 and 5 to - and + for my adapters.


----------



## i luvmusic 2

I love these thread i can asked anything and i can count on you guys the other thread if they think you are out of the topic they will shut you.


----------



## i luvmusic 2

Or maybe not yet for me here.


----------



## mordy

Hi TD and G,
  
 I am currently using two 2.5A 6080 Chatham tubes in the LD MKIII as power tubes with good results. Was just wondering if four tubes would be better, since the 6336 is said to be a double 6AS7/6080.
  
 However, I have a hunch that it might be too much current draw for the amp, so meanwhile I will shelve this option.
  
 SERENDIPITOUS: "Discovered by chance in a happy or beneficial way."
  
 I just had to try the 5687 with 12.6V. Disconnected the loop that connected tube pins 4 and 5 and connected the external PS to the heater pins 4 and 5 (previously the heater leads were connected to pins 4 and 8). It sounds fine and maybe a little different compared to 6.3V - needs further listening.
  
 Then the volume suddenly became lower, but everything sounded fine. What's going on? The PC 15A power supply has an of/off switch on the back of it, and by accident I had shut it off. No current to the power tubes, but everything works fine, except that I need to turn the volume up, but only by two notches. (Listening through speakers)
  
 How is it possible for the LD amp to work without the power tubes turned on?
  
 Connecting the headphones to the LD results in volume too low to be usable.
  
 Is the 5687 doing the job of all four tubes?


----------



## TrollDragon

Hey mordy,

Tubes will still conduct quite a while as they cool down... If the tubes were cold then what you are hearing is probably conducted through the LD's feedback circuit...

Did you turn the LD up 2 notches or your receiver? Try the same experiment with cold tubes and don't turn on the PC supply to the outputs.


----------



## mordy

The power tubes are completely cool - have been going for over an hour without power. The LD is turned up all the way, which is where I keep it with the 6AS7/6080 power tubes due to the low amplification factor. (All the way up with RCA 6AS7 and RCA 6080, almost all the way up with the Chatham 6080).
  
 The 5687 is running off a 5A voltage regulator set at 12.6V.


----------



## TrollDragon

Very Cool... 

So it is my guess the the feedback circuit in the LD is passing the audio along, I think you would find it not to work if you powered the output filaments instead of the driver.


----------



## joshk4

Hi,
  
 Sorry my bad, forgot to mention that I was using the Hifiman ef2a, I'm guessing this would be the same to the little dots?
  
 Thanks guys for helping me out.
  
 Josh


----------



## genclaymore

gibosi said:


> They are the same, that is 6ZH1P-EV = 6J1P-EV.
> 
> Purchasing matched pairs for the Little Dot is a waste of money. I purchased two pairs from this vendor:
> 
> ...


 

 I would had did that but I did not trust ordering tubes from outside of the usa, because I didn't want to go thru the hassle of getting a bad tube and sending it back. Plus I wouldn't had like it if I gotten a fake. So I got both my pairs in the usa to ease my mind, I know i spent too much but it put my mind at ease as if something went wrong  or sent bad ones I could easy send them back. Instead of paying a lot to ship them back outside of the usa. I also don't have any way to test them as I don't have a tube tester, plus one of you guys said power tube matching on little dot is pointless but I read conflicting stories that it could damaged or shorten life of the tube amp if it wasn't matched and I wasn't about to take that chance and would not look forward to my Little dot burning out which would mean i would be out of luck for months.


----------



## bbmiller

trolldragon said:


> Nice Schematic as well, I have a hand drawn MK IV version that I cobbled together.
> 
> 
> 
> Spoiler: MK IV Rough Schematic


 
 Do you think from looking at the way TrollDragon draws the 6.3 volt portion of the power supply that in its on modified form the little dot MK four headphone amplifier uses AC rather than DC voltage and current to heat its tubes and an alternative way to modify this amplifier to supply more current to the power tubes would be to drill a hole in the chassis and simply remove the wires from the press and transformer supplying the 6.3 AC and replace it with the more hefty external AC step down transformer with no regulation or rectification?


----------



## TrollDragon

Yes bbmiller you could very easily drill a hole in the backplate of the amplifier and run a higher current 6.3V into the tube filaments from am external power supply. The only thing is large current transformers are rather big, heavy and not cheap.

That is why all the guys here use a Switching Power Supply and an external regulator. But if you have access to a filament transformer then that would be an easy conversion, just unsolder and tie off the current filament leads coming from the LD's transformer and hook up your own.


----------



## TrollDragon

genclaymore said:


> I would had did that but I did not trust ordering tubes from outside of the usa, because I didn't want to go thru the hassle of getting a bad tube and sending it back. Plus I wouldn't had like it if I gotten a fake. So I got both my pairs in the usa to ease my mind, I know i spent too much but it put my mind at ease as if something went wrong  or sent bad ones I could easy send them back. Instead of paying a lot to ship them back outside of the usa. I also don't have any way to test them as I don't have a tube tester, plus one of you guys said power tube matching on little dot is pointless but I read conflicting stories that it could damaged or shorten life of the tube amp if it wasn't matched and I wasn't about to take that chance and would not look forward to my Little dot burning out which would mean i would be out of luck for months.


There are quite a few good Eastern Block eBay sellers that have a 100% rating who will not send you bad tubes, also they are cheap enough that one should order 3 or 4 just incase someone drops kicks the box during transport...

They don't fake tubes like the 6J1P A's it is really not worth the time to do so. It would be like someone counterfeiting $5 bills, they go after the tubes that are in high demand that they can get $100 for from uninformed new tube buyers.

Matched tubes are recommended for amplifiers that have parallel output power tubes which the Little Dot has none. There is only one output tube per channel and they are not a power tube although we label them such.

So unmatched tubes will not harm the LD amplifier and paying extra for them is just money wasted. But if you do have lots of extra dosh to splash around there is probably a matched pair of $80 Telefunken 6AK5's on Yenaudio that they would just love to sell you...


----------



## MIKELAP

genclaymore said:


> I would had did that but I did not trust ordering tubes from outside of the usa, because I didn't want to go thru the hassle of getting a bad tube and sending it back. Plus I wouldn't had like it if I gotten a fake. So I got both my pairs in the usa to ease my mind, I know i spent too much but it put my mind at ease as if something went wrong  or sent bad ones I could easy send them back. Instead of paying a lot to ship them back outside of the usa. I also don't have any way to test them as I don't have a tube tester, plus one of you guys said power tube matching on little dot is pointless but I read conflicting stories that it could damaged or shorten life of the tube amp if it wasn't matched and I wasn't about to take that chance and would not look forward to my Little dot burning out which would mean i would be out of luck for months.


 
 I have ordered tubes at least 35 times from abroad and the tubes always got here just check for sellers that have a good reputation and everything should be alright . And i also dont use matched tubes ive had my MK3 for several years now and all is find .


----------



## bbmiller

trolldragon said:


> Yes bbmiller you could very easily drill a hole in the backplate of the amplifier and run a higher current 6.3V into the tube filaments from am external power supply. The only thing is large current transformers are rather big, heavy and not cheap.
> 
> That is why all the guys here use a Switching Power Supply and an external regulator. But if you have access to a filament transformer then that would be an easy conversion, just unsolder and tie off the current filament leads coming from the LD's transformer and hook up your own.


 
 You said above an external power supply not simply a step down transformer to 6.3 AC as the complete package. Is my assertion that the on modified little dot MK IV runs on AC filament voltage correct?


----------



## mordy

Hi genclaymore,
  
 Agree completely with all the above comments about not having to worry about buying tubes from inexpensive reputable sources. The Little Dot MKIII that I have experience with is very sturdy, and I cannot remember people ruining the amp no matter what they threw at it.
  
 As a rule, there are two types of tube sellers on Ebay - those who make a living from it, and those who sell tubes as a side income. The commercial sellers will try to make you think that their tubes are much better and thus deserve very high prices, but the truth is that the grand daughter who is selling off her grandfather's stock of old tubes for a fraction of the price, is selling the exact same tube as the high priced one.
  
 By all means, it would be nice just to pick high priced tubes without worrying about the cost, but since the people on this forum bought thousands of tubes (collectively), and many of us have several hundred tubes, it makes financial sense to avoid the highest priced sellers, especially since they do not offer anything better than lower priced sellers of the same tube.
  
 The 6AK5 family of tubes were produced in enormous numbers, and should somebody want to replace the stock GE 6AK5 tubes that came with the LD MKIII with a new pair, there is no problem - you could buy 10,000 of them! ($1.20 each, incl shipping, or best offer)
  
 http://www.ebay.com/itm/MASSIVE-LOT-10-000-NOS-NIB-GENERAL-ELECTRIC-6AK5-6AK5W-5654-5654W-6J1-403A-TUBES-/301210986229?pt=Vintage_Electronics_R2&hash=item462192e6f5
  
 Yen Audio will happily sell you a pair of GE 6AK5 for $73.50 incl shipping......
  
 http://www.ebay.com/itm/2x-GE-Mobile-Radio-6AK5-Matched-Pair-Little-Dot-Amp-Mk-/290581310456
  
 Good luck!


----------



## TrollDragon

bbmiller said:


> You said above an external power supply not simply a step down transformer to 6.3 AC as the complete package. Is my assertion that the on modified little dot MK IV runs on AC filament voltage correct?


Hey bbmiller,

I am really not sure what you are trying to do or understand...

The LD amps have two separate windings on the built in power transformer to provide filament power to both output and driver tubes. There is a 6.3V 2.5A winding divided between the output tubes, and a 6.3V 1A winding divided between the driver tubes. This filament voltage is AC on an unmodified LD amplifier.

The guys here use both driver and output tubes that can draw more filament current than the LD transformer will safely provide, so this requires an external power source of some type for the filaments.

Since a higher current filament stepdown transformer ie 110VAC to 6.3VAC @ 10A is not easily or cheaply available, they run the filaments on 6.3VDC via a switching power supply and a 5A or 10A voltage regluator that can be adjusted down to 6.3VDC.

You could even run either pair of tube filaments in series from a 12.6V DC or AC source as well, but I don't wish to confuse the issue.

Has this answered your question?


----------



## bbmiller

trolldragon said:


> bbmiller said:
> 
> 
> > You said above an external power supply not simply a step down transformer to 6.3 AC as the complete package. Is my assertion that the on modified little dot MK IV runs on AC filament voltage correct?
> ...


 
 Yes that answered it. thanks


----------



## i luvmusic 2

I finally finish my CRACK after 12 hours.......time for bed.


----------



## CollectoR13

Pictures please! 
Very interested in how it looks (and sounds )!


----------



## MIKELAP

i luvmusic 2 said:


> I finally finish my CRACK after 12 hours.......time for bed.


 
 Now that's an addict


----------



## TrollDragon

i luvmusic 2 said:


> I finally finish my CRACK after 12 hours.......time for bed.


Nice!
I take it the build was very easy? You didn't have a handful of parts left over like the guy in the Crack thread and wonder why the amp won't turn on. 

Pictures and a sound comparison is mandatory!


----------



## i luvmusic 2

Pictures will be for later and about sound IMO very quiet,detailed,deep bass,smooth sounding and larger soundstage than my LD MK III i can see my self getting a next Crack in the future replacing my LD's it can even drive my Q7XX with no problem at all.I highly recommend it for anyone thinking of getting a next amp for High Z headphones.If you will asked me if it's better than LD's? yes even with my Butchered/modified LD's i preffered the BH CRACK.I'am enjoying this Amp with classical music due to it's black background and smooth sound.


----------



## TrollDragon

Did you install the Speedball right from the start or are you going to put it in later?


----------



## gibosi

1962 Heerlen-made 7119/E182CC
  


Spoiler: 7119/E182CC






  
 Having spent some time with this tube, I can say that it definitely has the Heerlen house sound.  A/B-ing between the E182CC and my 1960 Heerlen-made E188CC, I was struck by how similar they sound. Most noticeably, both display the signature Heerlen mid-range, lush and bright. And I was reminded why I preferred the slightly darker 1975 Voskhod 6N23P when I was more actively rolling 6DJ8-type tubes...
  
 The frequencies emphasized by this lush, bright mid-range are the same that are emphasized by reverb. Listening to female vocalists like Lana Del Ray and Jillian Banks, who use reverb on virtually every song, some tracks are just a bit too over the top (with HD700's) for my old tired ears. lol 
  
 That said, the E182CC compares very well to the E188CC, which is considered by many to be one of the very best, and the 7119/E182CC is typically more affordable and easier to find. So if a rather forward, bright, lush mid-range works well with your headphones, I believe these are definitely worth a try. As for me, I have gone back to my Sylvania 5687WA.


----------



## i luvmusic 2

trolldragon said:


> i luvmusic 2 said:
> 
> 
> > I finally finish my CRACK after 12 hours.......time for bed.
> ...


 
  I was surprised that i did not screwed up a lot,i do have a one extra part a piece of lock washer that it will not fit where it should be due to the other 9 pin socket i've used other than that the build went smooth.


----------



## i luvmusic 2

trolldragon said:


> Did you install the Speedball right from the start or are you going to put it in later?


 
 Not yet it will be for later i probably don't need it it sound very nice even only in stock form.


----------



## gibosi

This past weekend, I went to a local Hamfest and one of the vendors had a large assortment of tubes. Didn't see anything I couldn't live without, but did find a GE 5687. Searching Google, the GE doesn't seem to get much love, but for $8, cash and carry, figured I'd give it a try. 
  
 Will try to spend some time with it in the next several days, but for now, it lights up and plays.


----------



## i luvmusic 2




----------



## i luvmusic 2

mikelap said:


> i luvmusic 2 said:
> 
> 
> > I finally finish my CRACK after 12 hours.......time for bed.
> ...


 
 LOL.


----------



## mordy

Hi, 
  
 Exploring 5687 tubes - so far I have gotten one Sylvania, one GE and two Tung Sol. Usually tubes come with black or gray plates, and sometimes silver, but one of the Tung Sols has bronze plates. (The only other material for the tube plate I know of is graphite.)
  
 Can anybody tell me if there is any advantage to bronze plates?


----------



## gibosi

mordy said:


> Hi,
> 
> Exploring 5687 tubes - so far I have gotten one Sylvania, one GE and two Tung Sol. Usually tubes come with black or gray plates, and sometimes silver, but one of the Tung Sols has bronze plates. (The only other material for the tube plate I know of is graphite.)
> 
> Can anybody tell me if there is any advantage to bronze plates?


 
  
 Do they appear to actually be made of bronze? Or perhaps this is nothing more than paint, like black and gray plates?


----------



## i luvmusic 2

I plug in the SIEMENS ECC82 and it lights up like the 6HM5  few seconds later a loud CRACKLING sound on both channel while the volume is all the way down,What might that be?It's playing normal now that scares me i thought i blew my HP.


----------



## TrollDragon

i luvmusic 2 said:


>


 
 A very nice clean build, Props!
 Does BH provide the CMC sockets or are they your addition? The CMC's are such a nice socket to work with. Listen for a while, then get your Speedball installed as it supposedly brings some nice bass extension to the table.
  
 I want one now!


----------



## i luvmusic 2

trolldragon said:


> i luvmusic 2 said:
> 
> 
> >
> ...


 
  No i got them from parts connexion, yes i will be listening to it stock for now it looks like the SB is more tricky to solder than the CRACK it self ,you should get one specially it's cheaper than my  III and it sound really sweet with CHATHAM 6AS7G and SEIMENS ECC82.


----------



## gibosi

i luvmusic 2 said:


> I plug in the SIEMENS ECC82 and it lights up like the 6HM5  few seconds later a loud CRACKLING sound on both channel while the volume is all the way down,What might that be?It's playing normal now that scares me i thought i blew my HP.


 
  
 When tubes start up, it is not all that unusual to hear crackling and popping noises, so it is probably nothing to worry about.
  
 But just a reminder:  Unplug your headphones before turning the amp off.  And when turning the amp on, wait a couple minutes before plugging your headphones back in. This practice protects your ears and your headphones.


----------



## i luvmusic 2

gibosi said:


> i luvmusic 2 said:
> 
> 
> > I plug in the SIEMENS ECC82 and it lights up like the 6HM5  few seconds later a loud CRACKLING sound on both channel while the volume is all the way down,What might that be?It's playing normal now that scares me i thought i blew my HP.
> ...


 
 I never experienced like that before that is why it scares me a bit,Good to know and THANK YOU! for the info.


----------



## maidos

i wanna get into the tube rolling with my hd 650 but atm i can only get a pair either driver or power tubes, which one/type would you recommend ?
 i dont want to mod my littledot II


----------



## i luvmusic 2

6HM5 Yugoslavia  IMO better than any plug and play driver tubes i've tried Plus it comes with a fire works.


----------



## hypnos1

gibosi said:


> Wow! A pair of NOS CV2523! Wow! But yes, I agree, for the same cost there is significantly less risk in going with these versus 5998. But wow!


 
  
 Well, g, wow! doesn't really cover it...just when I thought there couldn't be any more _real_ OMGs from the Little Wonder, I get TWO of them! - and that's _before_ the NOS pair arrives from Italy!..Let me explain...
 Out of curiosity and on a whim, I rang around some UK valve dealers and after hearing enough times " no chance - VERY few and far between", and about to give up, I struck upon some "ex-equipment" tubes a third the price of the NOS ones. So of course I bagged a couple - spares are ALWAYS needed, no? Plus, I thought this would be a good way of checking those on their way, lol...
 Anyway, they arrive NEXT day, I open box 1...a nice Osram A1834, looking in very good condition...NICE. Then box 2...and *OMG* #1 - another Osram, but with CURVED base...like, the 'Holy Grail'!! The base alone is a minor work of art, and the rest of the tube just screams quality.
 Well, once I'd picked myself up from the floor I pop them in and...
	

	
	
		
		

		
		
	


	




...the first is dead (was offered full refund in such an event, but still _mightily_ disappointing). Luckily the curved-base gold strike is fine, so with this in the right channel and the Chatham in the left I proceed...and *OMG* #2 - could not believe my ears...smooth, rich, fluid - liquid gold. More weight to the bass and lower mids, with no loss of detail...on the contrary, even _more_ detail across the entire range...as mordy mentioned recently (from others' comments), as if more 'layers' to the sound - perhaps due in part to greater resolution of the harmonics?
 It would appear these tubes compensate for the generally regarded 'lighter' nature of the Chathams (which I must agree with - but which also gives them their magical 'air'). To finally confirm this 'fuller' sound, and see how they perform re handling dynamic range, I give them what I have found to be a VERY good test - tracks from the original music score of 'Gladiator', especially track 3 : 'Battle'. This actually brought a further *OMG* and blew me away (even more so than it usually does lol!). Dynamic range was handled with masterly aplomb, and the soundstage was just breathtaking 
	

	
	
		
		

		
		
	


	




.
  
 So all in all, it looks like this '6AS7G' combines the best of the 5998 with that of the Chatham 6AS7G...or could it be that the combo I have described might just be even greater than TWO Osram/GECs?...Time will tell, of course!
  
 Whatever, I already cannot believe (once again!) what these tubes are doing to the LD...
  
 So, gibosi, rather than _blaming_ you for encouraging me to "go for it", I wholeheartedly _thank_ you for same! ..




 .....The penultimate set-up...
  

  
 Cheers!


----------



## mordy

Hi i luv music 2,
  
 I always get some kind of brief surge and loud noise when turning on my tubes. Used to turn the volume all the way down, but no I push a button on my receiver to disconnect the speakers (no headphones plugged in) and watch my LED watt meters for a spike - usually after 20-30 seconds.
 Once that's gone I'll turn on the speakers, and all is well.
  
 Hi maidos,
  
 Agree with the suggestion for the 6HM5 tubes. Today you can get a pair for $14 of US made Sylvania (have not tried them, but got good reviews)
  
 http://www.ebay.com/itm/6HA5-6HM5-Sylvania-Electronic-Tube-NOS-/321474318998?pt=LH_DefaultDomain_0&hash=item4ad95cd296
  
 or the Yugoslavian Ei fireworks tubes (flash up when starting - quick heat feature) for 4 for $24.50 or 10 for $35.
  
 http://www.ebay.com/sch/i.html?_from=R40&_trksid=p2047675.m570.l1313.TR0.TRC0.H0.X6HM5+Ei&_nkw=6HM5+Ei&_sacat=0
  
 Good luck!


----------



## i luvmusic 2

mordy said:


> Hi i luv music 2,
> 
> I always get some kind of brief surge and loud noise when turning on my tubes. Used to turn the volume all the way down, but no I push a button on my receiver to disconnect the speakers (no headphones plugged in) and watch my LED watt meters for a spike - usually after 20-30 seconds.
> Once that's gone I'll turn on the speakers, and all is well.
> ...


 
  As i said before it never happened to me i know that tubes can have a spike during start up but this time it is very loud i don't even have my HP on my head and i heard it Crakle kind of scary experienced.I never unplug my HP during power on/off the amp but now i will start unplugging my HP.  Thanks!


----------



## mordy

Hy hypnos 1,
  
 Congrats on your find! Is the tube the same as this $615 pair?
  
 http://www.ebay.com/itm/A1834-6AS7G-OSRAM-BROWN-BASE-NOS-VALVE-TUBE-PAIR-K1-/390438538194


----------



## gibosi

Yes, A1834 = 6AS7G = CV2523, so the same tubes. Some of these GEC/MOV (Marconi-Osram Valve) tubes have a curved base bottom and some don't, as you can see on this page:
  
 http://the-key.enix.org/~krystal/review-tube-bottlehead.html


----------



## Nic Rhodes

hypnos1 said:


> You bet ya, M!
> 
> 
> Hi Nic...you tryin' to give me _another _heart attack lol?! They were listed as Mullards, and I know 'their' 6AS7Gs were in fact Russians...but hopefully these are the real deal - they certainly look it, from the photos...any comments? :
> ...


 

  Yes I would happy if you sent me these  I would check the manufacurer codes when they decent however, you never know what you might have


----------



## gibosi

hypnos1 said:


> So, gibosi, rather than _blaming_ you for encouraging me to "go for it", I wholeheartedly _thank_ you for same! ..


 
  
 Given the reputation of these GEC/MOV 6AS7's there was never any doubt in my mind. I knew these tubes would sound glorious with the C3g/s. 
  
 I think you have taken your Little Dot *almost* as far as it can go. All that's left is to slap on an external socket. add another external power supply and roll some double triodes! 
  
 Cheers lol


----------



## hypnos1

mordy said:


> Hy hypnos 1,
> 
> Congrats on your find! Is the tube the same as this $615 pair?
> 
> http://www.ebay.com/itm/A1834-6AS7G-OSRAM-BROWN-BASE-NOS-VALVE-TUBE-PAIR-K1-/390438538194


 
  
 Hi mordy, thanks...yep, sure is! You can see why they almost had to pick me up off the floor, eh? Especially at $50! - which I know is still way above what you manage to find tubes for, but I fear there isn't much chance of finding anything to touch these tubes...at anywhere near _this_ price...or even the NOS pair yet to come (which, unfortunately, don't have the curved base...but which apparently are almost indiscernible in sound quality - I did, however, notice that my 'dead' straight-sided-base tube didn't scream _quite_ the same quality of construction...once again it appears that the old'uns are the best, lol!).


----------



## hypnos1

nic rhodes said:


> Yes I would happy if you sent me these  I would check the manufacurer codes when they decent however, you never know what you might have


 
  
 Thanks Nic...if you would be happy, then I am pretty hopeful for them...shame they're not Osram curved-base! (Then again, they would have been a _really_ silly price I suppose..
	

	
	
		
		

		
		
	


	




).
  


gibosi said:


> Given the reputation of these GEC/MOV 6AS7's there was never any doubt in my mind. I knew these tubes would sound glorious with the C3g/s.
> 
> I think you have taken your Little Dot *almost* as far as it can go. All that's left is to slap on an external socket. add another external power supply and roll some double triodes!
> 
> Cheers lol


 
  
 Sorry, g....too much excitement I can't handle so easily these days lol! Let me get over this one first...not to mention even _more_ to come - hopefully.
  
 Do you really think I can surpass the C3GS by much - given their 'synergy' with the 6AS7Gs, especially this latest version? I find it hard to see in what area there could now be noticeable improvement...
	

	
	
		
		

		
		
	


	




...


----------



## kvtaco17

So my C3gs arrived today and I get almost no output... the tubes test good, its almost like someone forgot to hook something up in the adapter...


----------



## gibosi

kvtaco17 said:


> So my C3gs arrived today and I get almost no output... the tubes test good, its almost like someone forgot to hook something up in the adapter...


 
  
 And given that it is both tubes, and not just one, I agree that it is quite likely the adapters are defective....


----------



## kvtaco17

gibosi said:


> And given that it is both tubes, and not just one, I agree that it is quite likely the adapters are defective....


 

 Worst disappointment ever lol
  
 gibosi where did you get your adapters? I have the crappy flee-bay version...


----------



## gibosi

kvtaco17 said:


> Worst disappointment ever lol
> 
> gibosi where did you get your adapters? I have the crappy flee-bay version...


 
  
 I got mine from the Hong Kong eBay seller happydiy998
  
 hhttp://www.ebay.com/itm/301131714830?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649


----------



## kvtaco17

gibosi said:


> I got mine from the Hong Kong eBay seller happydiy998
> 
> hhttp://www.ebay.com/itm/301131714830?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649


 
 Yup those are what I have... I might need to go over there and tell my people to step up their quality of work...


----------



## Oskari

nic rhodes said:


> hypnos1 said:
> 
> 
> > They look pretty Kosher to me...fingers crossed (listed as made in UK so if not, they go straight back!).
> ...


 
  
 Irrespective of the brand, they were all made by MOV, and that inverted pan getter is very much MOV. You can also see the code (Z) for the MOV Hammersmith factory in the photo. MOV was originally owned by Marconi and GEC, later by EMI and GEC, and finally solely by GEC. Osram was a GEC brand (in the UK).


----------



## Nic Rhodes

oskari said:


> Irrespective of the brand, they were all made by MOV, and that inverted pan getter is very much MOV. You can also see the code (Z) for the MOV Hammersmith factory in the photo. MOV was originally owned by Marconi and GEC, later by EMI and GEC, and finally solely by GEC. Osram was a GEC brand (in the UK).


 
  I think many of us know that already but the buyer now misses the joy of checking the manufacturers code when it decends himself


----------



## hypnos1

oskari said:


> Irrespective of the brand, they were all made by MOV, and that inverted pan getter is very much MOV. You can also see the code (Z) for the MOV Hammersmith factory in the photo. MOV was originally owned by Marconi and GEC, later by EMI and GEC, and finally solely by GEC. Osram was a GEC brand (in the UK).


 
  
 Thanks Oskari...can definitely sleep soundly now...
  
 Cheers, and goodnight!


----------



## gibosi

hypnos1 said:


> Sorry, g....too much excitement I can't handle so easily these days lol! Let me get over this one first...not to mention even _more_ to come - hopefully.
> 
> Do you really think I can surpass the C3GS by much - given their 'synergy' with the 6AS7Gs, especially this latest version? I find it hard to see in what area there could now be noticeable improvement...
> 
> ...


 
  
 I don't think I can count the number of times you have said, "I find it hard to see in what area there could now be noticeable improvement..." Almost every time you have made a change. lol 
  
 But it is very hard to predict. When we are talking about top-tier tubes like the C3g, it is simply not possible to say one is clearly better than the other. The differences are not black and white. They are more like different shades of gray. And selecting which shade of gray is best is a very subjective and even an emotional decision. So given there are quite a few double triodes that can be considered as good as the C3g, if you could try a half a dozen or so, there is a very real possibility that you might like one better than the Cg3. And of course there is a very real possibility that you might not.
  
 To paraphrase Mordy, tubes are like ice cream. And in order to know which flavor is your favorite, you simply must try every flavor in the ice cream shop. So you best get cracking!  lol


----------



## mordy

Not sure if it is necessary to try every flavor LOL. When I came to New York in the 60's I was amazed to see celery soda - Dr. Brown's Cel-Ray. Don't like the flavor of raw celery, so I would stay away from celery ice cream.
 Seriously, it may be a good idea to try certain dual triode tubes that come well recommended; certain octals 6SL7 and 6SN7, the sub miniature 7963 or 6832, and the 5687 (Sylvania, Tung Sol and Raytheon).
  
 The there is the question of synergy with the power tubes.....


----------



## maidos

im interested to buy 6HM5 sylvania but is it the tall tube or the short ones? i prefer to keep the stock driver (short ones) and getting the new tubes does it mean i have to change gain switch and also i noticed it got less pins than what my little dot mk2 has :S the stock one got 9 pins while 6hm5 got only 7 pins, how would i connect it correctly?
  
 Quote:


> Originally Posted by *mordy* /img/forum/go_quote.gif
> 
> 
> Hi maidos,
> ...


----------



## maidos

nvm appears my stock tubes started to have really loud buzzing noise, not sure which of them so im just gonna replace all 4 of them(removed all 4 tubes and powered the amp and buzzing noise were gone). so for the power tubes i will go 6hm5 what about the driver tubes?
 use little dot mk2, prefer not to mod or buy any adapters.


----------



## MMMan

<snip snip snip> 





> .....The penultimate set-up...
> 
> 
> 
> Cheers!


 
  
 Hi H,
  
 Great find... and BTW, what are the drivers in your pic? I know I should know this, but I am a step out of time... my C3g/s haven't arrived yet so I don't know what they look like with their caps removed...
  
 Best,
 G


----------



## MMMan

So, here is my 'blast from the past': Tonight I fell in love with my LD Mk IV all over again!!
  
 My 6SN7 adaptors arrived tonight, so I finally got to try some totally new power tubes!! The only ones I have right now are 1955 Sylvania 6SN7GTB black plates ($25)... but wow, they sound beautiful!! Biggest improvement from any tube (driver or power) I have put  into this preamp!! I am deft going to stay and play with 6SN7s for a while. I have some Russians on the way and I found a great price on some Mickey Mouse ear Tung Sols ($22)... 
  
 On another note, my current drivers are some Russian 6J3P-Es marked OTK <0> ($8.50 for 10!!). Lampizator says zero in rhombus is 'space'... which I tend to believe. They came with the best packaging of any Russian tube I own, each with its own data sheet. They sound very nice with these 6SN7s... but I'm going to have fun rolling some other drivers. Can't wait for my C3g/s to arrive!!
  
 Thanks again to you all for finding the path!!
  
 Best,
  
 G


----------



## jamca

could you please tell me a few things about how gain options affect the amp's sound? i have searched really a lot but i could not find anything specific and for sure. i will tell you which conclusions i made and i would like to discuss if they are right or wrong....so as i understand,  high gain means that the amplifier amps a lot( go louder) so we hear more tubey sound as it works ''more'' . The sound hass less soundstage but with more impact, with more treble and bass. So you may thing at first that it is more analytical but this might be becouse or the more treble.  At the opposite lower gain means that sound is more pure, as the diffference from the music source is smaller, the soundstage becomes bigger but with no such impact as the bass and treble goes down. With low gain the sound becomes more real and matches better with the true sound of the source. I have also read that lowering gain means rising negative feedback ( a function of the amplifier)  which means two things, first better frequency response and less distortion and secondly lower output impedance.  
   Well now i need your help...which of those things are true and which are not. I would like someone to explane how the gain function work and especially how it influences, if it does, the output impedance. Also is enywhere the actual output impedance of little dot mk3?  Thanks a lot!!!!!!!


----------



## kvtaco17

maidos said:


>


 
 get the Yugo's they rock pretty hard and have more body then the Sylvania's, both a great... just never get a short bottle one... they kinda suck...


----------



## TrollDragon

maidos said:


> nvm appears my stock tubes started to have really loud buzzing noise, not sure which of them so im just gonna replace all 4 of them(removed all 4 tubes and powered the amp and buzzing noise were gone). so for the power tubes i will go 6hm5 what about the driver tubes?
> use little dot mk2, prefer not to mod or buy any adapters.


The 6HM5's are the driver tubes, they go in the front of the amp. When you buy 6HM5's make sure to get the tall version as opposed to the short ones, the tall version sounds better. Members here have had very good luck with the Yugoslavian 6HM5's from the link posted earlier.

Your output tubes are 6N6's, they should be put back or replaced with 6H6PI's or 6H6N's, there are not many options for output tubes in an unmodified LD. 

Someone here with a MKII could chime in with which output tubes they use.


----------



## MMMan

jamca said:


> could you please tell me a few things about how gain options affect the amp's sound? i have searched really a lot but i could not find anything specific and for sure. i will tell you which conclusions i made and i would like to discuss if they are right or wrong....so as i understand,  high gain means that the amplifier amps a lot( go louder) so we hear more tubey sound as it works ''more'' . The sound hass less soundstage but with more impact, with more treble and bass. So you may thing at first that it is more analytical but this might be becouse or the more treble.  At the opposite lower gain means that sound is more pure, as the diffference from the music source is smaller, the soundstage becomes bigger but with no such impact as the bass and treble goes down. With low gain the sound becomes more real and matches better with the true sound of the source. I have also read that lowering gain means rising negative feedback ( a function of the amplifier)  which means two things, first better frequency response and less distortion and secondly lower output impedance.
> Well now i need your help...which of those things are true and which are not. I would like someone to explane how the gain function work and especially how it influences, if it does, the output impedance. Also is enywhere the actual output impedance of little dot mk3?  Thanks a lot!!!!!!!




From this thread, I've learned that 'gain' has a different impact on different headphone/system combinations. Some people like a higher gain because it sound better with thei specific tube/headphone combinations. I have tried different gain settings with my sennheiser hd650s... And I like the lowest gain settings. Although higher gain settings are louder, I find the bass louder but not as ' tight'.... It's a mushy bass that I'm not too keen on. Different people like different settings, so try changing gain and see what you like best...

Cheers,

G


----------



## TrollDragon

jamca said:


> could you please tell me a few things about how gain options affect the amp's sound? i have searched really a lot but i could not find anything specific and for sure. i will tell you which conclusions i made and i would like to discuss if they are right or wrong....so as i understand,  high gain means that the amplifier amps a lot( go louder) so we hear more tubey sound as it works ''more'' . The sound hass less soundstage but with more impact, with more treble and bass. So you may thing at first that it is more analytical but this might be becouse or the more treble.  At the opposite lower gain means that sound is more pure, as the diffference from the music source is smaller, the soundstage becomes bigger but with no such impact as the bass and treble goes down. With low gain the sound becomes more real and matches better with the true sound of the source. I have also read that lowering gain means rising negative feedback ( a function of the amplifier)  which means two things, first better frequency response and less distortion and secondly lower output impedance.
> Well now i need your help...which of those things are true and which are not. I would like someone to explane how the gain function work and especially how it influences, if it does, the output impedance. Also is enywhere the actual output impedance of little dot mk3?  Thanks a lot!!!!!!!


With the gain on the LD most of us here use 5. The amplfier comes set at 3 from the factory and I had to turn my volume up 3/4 with the 250 Ohm DT880's.

I like a listening level that is around the middle of the volume control so I use 5 which gives me a 10-11 o'clock decent listening level. I tried gain 10 but the volume ramped up to quickly for me.

I don't think there is a published output impedance on the amplifier since it is designed to drive High-Z headphones it is not really that important.

The LD I+ is a hybrid made for Low-Z headphones so that might have a value published somewhere.


----------



## jamca

thanks a lot for the replies...personally i have set the gain at 4 which gives me some loudness boost but also keeps the bass tignt enough for my tastes...i think it sounds cleaner, with wider soundstage and less distortion. also with better, more accurate frequency response . i have sennheiser hd650, the first vesion... it is nice to tell what we think with the changes we make because the placebo effect is always there and we need verification!!


----------



## TrollDragon

jamca said:


> thanks a lot for the replies...personally i have set the gain at 4 which gives me some loudness boost but also keeps the bass tignt enough for my tastes...i think it sounds cleaner, with wider soundstage and less distortion. also with better, more accurate frequency response . i have sennheiser hd650, the first vesion... it is nice to tell what we think with the changes we make because the placebo effect is always there and we need verification!!


 
 Excellent, it is all about what sounds good to you with your ears and gears.
  
 We had a similar discussion in the X3 thread about how people thought that High Gain sounded better than Low Gain on the X3. If you take two identical units with the same songs, set one to high gain and one to low gain then switch between the units with a headphone switcher, we perceive the unit with high gain to sound better since it is louder. If you actually SPL match the two units with a meter, hit play and switch between the two you will find that they sound exactly the same.
  
  
 So in theory the LD amplifier should sound the same at all the gain settings since the gain is only supposed to provide amplification and not colouration, this we do find not to be the case in the LD amps due to the feedback circuit and other factors in the amplifier.


----------



## jamca

trolldragon said:


> Excellent, it is all about what sounds good to you with your ears and gears.
> 
> We had a similar discussion in the X3 thread about how people thought that High Gain sounded better than Low Gain on the X3. If you take two identical units with the same songs, set one to high gain and one to low gain then switch between the units with a headphone switcher, we perceive the unit with high gain to sound better since it is louder. If you actually SPL match the two units with a meter, hit play and switch between the two you will find that they sound exactly the same.
> 
> ...


 
 i agree that we must trust our ears...however i think that gain at little dot mkiii has not to do only with signal amplification, but with an internal function( i think negative feedback) in order to provide lower distortion and better frequency responce. The lower amplification is just the result of this process. I will post the link where i read this, if i find it later. But as i wrote, I THINK , so do not trust me too much because i am also confused with this...


----------



## mab1376

Does anyone have any VT-229 or VT-231 pairs for sale? i'm looking to replace my current production Tung-Sol 6SN7GTB power tubes with something sweeter.


----------



## hypnos1

kvtaco17 said:


> Yup those are what I have... I might need to go over there and tell my people to step up their quality of work...


 
  
 You have my deepest sympathy, kvt...one reason why I make my own adapters lol - but not for the faint-hearted!


gibosi said:


> I don't think I can count the number of times you have said, "I find it hard to see in what area there could now be noticeable improvement..." Almost every time you have made a change. lol
> 
> But it is very hard to predict. When we are talking about top-tier tubes like the C3g, it is simply not possible to say one is clearly better than the other. The differences are not black and white. They are more like different shades of gray. And selecting which shade of gray is best is a very subjective and even an emotional decision. So given there are quite a few double triodes that can be considered as good as the C3g, if you could try a half a dozen or so, there is a very real possibility that you might like one better than the Cg3. And of course there is a very real possibility that you might not.
> 
> To paraphrase Mordy, tubes are like ice cream. And in order to know which flavor is your favorite, you simply must try every flavor in the ice cream shop. So you best get cracking!  lol


 
  
 You are absolutely right, gibosi...will I ever learn? I know it only too well - I also can't count the number of times I've crept into bed after a midnight listen, to be greeted with...well? To which I reply : I can't believe it. To which _she_ replies : that's what you said _last_ time! To which I reply : I KNOW!!
 I should know by now - NEVER SAY NEVER AGAIN, lol 
	

	
	
		
		

		
			





. So it looks like I have a Winter project on my hands (sorry missus!) - especially as I also have mordy egging me on! Ah well, I do after all have some nice double triodes - VT231s/7N7s/PsVanes. Would be a shame really not to put them to further use...so long as I can keep it NEAT!!
  
 As an update to my gold strike Osram A1834, today I received the replacement for the dead tube...ANOTHER curved-bottom base GEC!!...Halleluja!...BUT, talk about rollercoaster rides in this game - not a murmur when plugged in...
	

	
	
		
		

		
		
	


	




. So now I have to hope against hope they might have one more...but it's looking a bit dodgy with these used tubes. Thank heavens the two on their way from Italy are NOS...but then, _nothing_ is guaranteed in this life, non? Fingers crossed...
  
  


mmman said:


> Hi H,
> 
> Great find... and BTW, what are the drivers in your pic? I know I should know this, but I am a step out of time... my C3g/s haven't arrived yet so I don't know what they look like with their caps removed...
> 
> ...


 
  
 Thanks MMMan. You were pretty well there...they are indeed the C3g(S)s. I just hope to God you are luckier than a couple of others have been with the adapters - kvtaco being the latest. But it looks like things get sorted in the end, if such a fate does befall...
 Good luck, anyway, and can't wait to hear your impressions (eventually!)...same goes for you, kvtaco...
  
 Cheers,
  
 CJ


----------



## mordy

Hi jamca,
  
 Here is information on gain in the LD MKIII - hope it helps. In my personal experience, I get the best sound by leaving the internal DIP switches on 5 (this is headphone dependent), and the volume set as high as possible before distortion sets in.
  
 Here is a link to the Little Dot manual for MKIII. Pages 8 and 9 have information on gain. You need to click on the link at the bottom of this page where it says dropbox.
  
  
 http://www.littledot.net/forum/viewtopic.php?f=9&t=815&sid=d19a88fc5a2b44c2f0c87179030bd08d#p3199


----------



## Oskari

nic rhodes said:


> I think many of us know that already but the buyer now misses the joy of checking the manufacturers code when it decends himself




He'll still have the date code to crack...


----------



## Oskari

hypnos1 said:


> Thanks Oskari...can definitely sleep soundly now...
> 
> Cheers, and goodnight!




I certainly did. 

(Some nights can be difficult with this heat wave we're having.)


----------



## maidos

can anyone pleasde recommend me 9 pin driver and power tube? dont wish to mod my mk2
 i was thinking about getting this but havent found ppl tried this out
 http://www.ebay.com/itm/ECC99-E182CC-GOLD-GRID-6N6P-2-NEW-NOS-1978-/360919318768
 http://www.ebay.com/itm/6DJ8-E88CC-VINTAGE-USSR-6N23P-TUBES-2-NEW-NOS-/360920204105
 http://www.ebay.co.uk/itm/6J1P-EV-6N6P-i-Full-matched-kit-of-strong-Russian-tubes-for-Little-Dot-MK-II-III-/141219079721?pt=Vintage_Electronics_R2&hash=item20e1502629


----------



## Rossliew

hypnos1 said:


> Well, g, wow! doesn't really cover it...just when I thought there couldn't be any more _real_ OMGs from the Little Wonder, I get TWO of them! - and that's _before_ the NOS pair arrives from Italy!..Let me explain...
> Out of curiosity and on a whim, I rang around some UK valve dealers and after hearing enough times " no chance - VERY few and far between", and about to give up, I struck upon some "ex-equipment" tubes a third the price of the NOS ones. So of course I bagged a couple - spares are ALWAYS needed, no? Plus, I thought this would be a good way of checking those on their way, lol...
> Anyway, they arrive NEXT day, I open box 1...a nice Osram A1834, looking in very good condition...NICE. Then box 2...and *OMG* #1 - another Osram, but with CURVED base...like, the 'Holy Grail'!! The base alone is a minor work of art, and the rest of the tube just screams quality.
> Well, once I'd picked myself up from the floor I pop them in and...
> ...


 
 @hypnos1 , will your tube set up in the picture above work just the same for a Mk 3? I thought 6AS7s are not plug and play for Mk 3s...or I could have read it wrongly..


----------



## gibosi

maidos said:


> can anyone pleasde recommend me 9 pin driver and power tube? dont wish to mod my mk2
> i was thinking about getting this but havent found ppl tried this out
> http://www.ebay.com/itm/ECC99-E182CC-GOLD-GRID-6N6P-2-NEW-NOS-1978-/360919318768
> http://www.ebay.com/itm/6DJ8-E88CC-VINTAGE-USSR-6N23P-TUBES-2-NEW-NOS-/360920204105
> http://www.ebay.co.uk/itm/6J1P-EV-6N6P-i-Full-matched-kit-of-strong-Russian-tubes-for-Little-Dot-MK-II-III-/141219079721?pt=Vintage_Electronics_R2&hash=item20e1502629


 
  
 As you don't want to use any mods, then your drivers, the tubes in front, must be 7-pin tubes.
  
 The first listing, for a pair of "ECC99 / ~ E182CC / GOLD GRID 6N6P", is suitable for power tubes.
  
 The second listing, for a pair of "6DJ8 / E88CC / VINTAGE USSR 6N23P TUBES", is *not* suitable as power tubes or drivers. This tube can be used as a driver only with modifications.
  
 The third listing, for two pairs, "6J1P-EV 6N6P-i Full matched kit of strong Russian tubes for Little Dot MK II III" gives you two drivers (6J1P-EV) and two power tubes (6N6P-I) that are suitable for your mk2.


----------



## maidos

gibosi said:


> As you don't want to use any mods, then your drivers, the tubes in front, must be 7-pin tubes.
> 
> The first listing, for a pair of "ECC99 / ~ E182CC / GOLD GRID 6N6P", is suitable for power tubes.
> 
> ...


 
 but my mk2 only have inputs of 9 pins holes for power and drives, it wouldnt be compatible if i get a 7 pin :S


----------



## gibosi

maidos said:


> but my mk2 only have inputs of 9 pins holes for power and drives, it wouldnt be compatible if i get a 7 pin :S


 
  
 The current mk2 uses EF91, EF92 and EF95 tubes as drivers, all 7-pin.
  
 http://www.littledot.net/forum/viewtopic.php?f=9&t=816&sid=0d126f86cbec27983de3662f17e2779e


----------



## hypnos1

rossliew said:


> @hypnos1 , will your tube set up in the picture above work just the same for a Mk 3? I thought 6AS7s are not plug and play for Mk 3s...or I could have read it wrongly..


 
  
 Hi Rossliew.
  
 Unfortunately 6AS7s are NOT plug and play for any of our LDs...they need the same adapters used for the 6SN7, but with the adapter's heater pins removed and the 6AS7g's fed by a separate external DC power supply - they draw 2.5A each, so we look for a supply that provides some extra (10 or 15A), and as they are usually 12V we have to route it through a step-down converter to get the 6.3V needed. So it's quite a bit of work, especially if you're not used to much DIY...but not _too_ difficult if you follow all the info posted on this topic.
 I have to admit there's a further requirement with the MK 3...because of those rings, which are not easy to remove, you also need an 'extender' (test) adapter, so the end result must look a little like the Eiffel Tower lol! (Unless you go gibosi's and mordy's route using 'breadboards').
  
 I managed to get my set-up looking a bit neater by making my own adapters and routing the heater wires out the back - almost hidden. But this is not really for those who don't feel confident with DIY - and who are not prepared to be ULTRA careful...damage to the amp is one thing, but to one'sSELF?... 
	

	
	
		
		

		
			





.
  
 So if you want to try the 6AS7(G)s/6080s, you will find plenty of support right here lol!


----------



## Rossliew

hypnos1 said:


> Hi Rossliew.
> 
> Unfortunately 6AS7s are NOT plug and play for any of our LDs...they need the same adapters used for the 6SN7, but with the adapter's heater pins removed and the 6AS7g's fed by a separate external DC power supply - they draw 2.5A each, so we look for a supply that provides some extra (10 or 15A), and as they are usually 12V we have to route it through a step-down converter to get the 6.3V needed. So it's quite a bit of work, especially if you're not used to much DIY...but not _too_ difficult if you follow all the info posted on this topic.
> I have to admit there's a further requirement with the MK 3...because of those rings, which are not easy to remove, you also need an 'extender' (test) adapter, so the end result must look a little like the Eiffel Tower lol! (Unless you go gibosi's and mordy's route using 'breadboards').
> ...


 
 Hahahaha...thanks, mate! Am not a DIY guy so I'll stick with my 6SN7s


----------



## mordy

Hi,
  
 Are you familiar with quick change knock-off racing wheels on cars?
  




  




  
 Well, I have developed a quick change method for changing dual triodes using a breadboard. Here goes - you leave the Little Dot amp on, you leave on the the power tubes with external power, and in my case, leave the receiver on. The only disconnect is the external power supply to the driver tube.
  
 I let the music play, pull the plug to the external PS for the driver tube, and wait until the music fades away - usually in some 20-30 seconds. When it is quiet, I take a rag, wrap it around the hot tube and pull it out. The push in the next tube. Turn on the power supply; after a few seconds the tube starts to warm up and the sound gradually comes on. No pops or unwanted noise, just the sound level increasing gradually to normal.
  
 In this manner I have been able to quickly run through my cache of 5687 tubes and compare them to each other. More about this in the next post...


----------



## TrollDragon

That's going to bite you on the butt at some point, as the socket pins still have a high voltage on them...


----------



## mordy

Hi,
  
 First thanks to Gibosi for (re)introducing the 5687 tube to this forum. IMHO this is a super tube with beautiful sound and available very inexpensively if you take the time to shop. Seems that audio amplifiers employing this tube use pairs or quads. Since the Little Dot only needs one, single tubes can be found at very reasonable prices.
  
 The cognoscenti seem to prefer Tung Sol, Sylvania and Raytheon tubes. I managed to buy six tubes for between $4 -$8 incl. shipping from three different sellers - 3 TS, one Sylvania and 2 GE. (Didn't yet find a Raytheon at my self imposed price limit).
  
 All these tubes can be run at 6.3V or 12.6V. I choose 12.6V because of a preconceived idea that the higher voltage tightens up the bass. When I can muster enough energy to rewire the breadboard for 6.3V operation for these tubes I am going to try to debunk my own (mis)conception and try to come to a conclusion. Be it what it may, here is the comparo: Note: Since I am shopping in the bargain basement of Ebay, one has to assume that all tubes are used, although perhaps some are NOS. In addition, the markings on some had worn off, and I cannot date them, but I was able to identify the manufacturers. Also note that power tubes used in this comparison test were 1960 Chatham 6080 tubes.
  
 GE 5687: March 1961, blk plate, copper rods, doubled top mica layer. Thinner sounding than the others, less bass and punch, laid back sound.
 GE 5687WA: Blk plate, copper rods, doubled top mica layer. Good sounding but bright and a little thin sounding, although strong bass. Sound stage not wide.
  
 Tung Sol 5687: Blk plate, excellent bass, somewhat bright, very good sound stage
 Tung Sol 5687 JTL: June 1966, bronze plate. Have never seen bronze plate before. Under a magnifying glass the bronze plate looks like metal (gun) color with brown algae growing on it - don't know what this means. This tube has super deep round bass, a wide and deep sound stage with depth; not bright.
 Tung Sol 5687: Sept. 1964, blk plate. Sounds great, like something in between the first two.
  
 Sylvania 5687WA: Blk plate, copper rods. Deep fat bass, wider and deeper sound stage than the TS; very detailed and musical.
  
 The winner in this comparo is the Sylvania followed by the 1964 and 1966 Tung Sol tubes. Please note that even the GE tubes are miles ahead of the best EF95 tubes.
  
 At this point the 5687 is one of my favorite tubes.


----------



## mordy

Hi TD,
  
 Was waiting for your response....A couple weeks ago I got quite a shock when I accidentally brushed against the top of one of my Vector adapters. I am trying to be very careful - did not like that experience.
  
 If I shut down the Little Dot, but left on the heaters to the power tubes (6.3V) and left the receiver on, could I avoid the high voltage?


----------



## TrollDragon

mordy said:


> Hi TD,
> 
> Was waiting for your response....A couple weeks ago I got quite a shock when I accidentally brushed against the top of one of my Vector adapters. I am trying to be very careful - did not like that experience.
> 
> If I shut down the Little Dot, but left on the heaters to the power tubes (6.3V) and left the receiver on, could I avoid the high voltage?


 
 Hey mordy,
  
 Unless a device is designed for "Hot Swap" it is always never a good practice to remove components while the device is live.
  
 Let's say you not quite on the ball one night and you get the tube a little cockeyed, while attempting to put the tube in you discover the filament pins have nicely bridged the plate and grid connections. I don't know what you use for a source but I doubt it would be too pleased with a 100+ volts driven into the Line Out jacks.
  
 If you must do this then leaving the filaments powered would be a lot less harmful in the above scenario than having the amp powered up and yanking tubes from it.
  
  
 On a side note:
 I'd really like to know how an amplifier alters "Sound Stage" when that is a function of the speakers / room  or headphones / ears. Unless an amplifier has a serious channel imbalance or there is some complex signal processing involved e.g.a DAC, how does an amplifier or even a tube alter the perceived "Sound Stage"?


----------



## mordy

Hi TD,
  
 Thanks for the advice - I'll power off the stuff when I change the tubes. I could still speed up the change by just waiting for the sound to stop.
  
 Re sound stage, I recall borrowing a Dynaco tube preamplifier from a neighbor in the 70's. It had a switch that allowed you to "stretch" the sound stage - perhaps a function of a time delay.
  
 I've noticed that Sylvania tubes often have a wide sound stage. My guess is that there is some kind of way to engineer a delay somewhere in the signal internally in the tube, but I do not know for sure.
  
 Some recordings convey a much larger space than others to the point that some instruments appear to come from beyond the speakers. It appears to me that this is a function of the microphones used and their placement.


----------



## i luvmusic 2

So it wasn't me alone got shock from Mr. Vector i remember posting something like that before.


----------



## gibosi

trolldragon said:


> On a side note:
> I'd really like to know how an amplifier alters "Sound Stage" when that is a function of the speakers / room  or headphones / ears. Unless an amplifier has a serious channel imbalance or there is some complex signal processing involved e.g.a DAC, how does an amplifier or even a tube alter the perceived "Sound Stage"?


 
  
 I believe my understandings are largely intuitive, rather than technical, so they may well be wrong......
  
 With that proviso, it is my understanding that "sound stage" information, such as room acoustics and instrument placement, are captured in the original recording. As with all musical information, this spacial information can be altered or even lost due to non-linearity, distortion, noise, phase shift, and so forth. Some tubes appear to project a narrow sound stage while others a much wider sound stage. Some project a deep 3-D sound stage while others a flatter 2-D sound stage. Which ones are the most accurate? I don't know, but I wouldn't be surprised to learn that tubes that amplify and enhance this information are the ones I like the best.
  
 Cheers


----------



## MMMan

trolldragon said:


> Hey mordy,
> 
> 
> On a side note:
> I'd really like to know how an amplifier alters "Sound Stage" when that is a function of the speakers / room  or headphones / ears. Unless an amplifier has a serious channel imbalance or there is some complex signal processing involved e.g.a DAC, how does an amplifier or even a tube alter the perceived "Sound Stage"?




I suspect soundstage is an artefact created by the sound engineer when re-mixing tracks recorded separately. Each instrument is given a different position on the L/R channel. Some stronger left, some stronger right. Also, each instrument has its own unique tonal range. Our amps, speakers and rooms never reproduce the recording faithfully. Some systems are good at a certain range, and 'position' certain instruments properly. Make a system change, and a different instrument is positioned 'properly' because different tonal ranges are reproduced properly. This makes it sound like instruments move around when we make system changes.... No magic, simple physics.

Best,

G


----------



## mordy

There is no doubt in my mind that certain equipment and tubes capture the soundstage and recording much better than others. Certain tubes will let you identify the individual instruments very clearly, and you can follow one individual instrument throughout a recording, ("pinpoint imaging").
  
 It is very interesting that high quality mono recordings may have a sound stage. The earliest direct to disc (!) acoustic recordings sometimes have a small soundstage, and a high quality early 20's electric mono recording may have a wider sound stage. Instead of mixing different tracks, the players were placed at different distances from the acoustic horn or electric microphone. A louder sounding instrument may be perceived as being closer.
  
 Then you have the effect of speakers, speaker placement and room interaction. The speakers I have usually project a sound image that appears between the speakers and isn't directly traced to each speaker.
  
 It appears to me that soundstage and imaging is a very complex subject that perhaps is more art than science.....


----------



## TrollDragon

Hey @mordy, @gibosi and @MMMan
  
 Thanks for all the opinions on Sound Stage guys, I realize it was really a question for the "Sound Science Asylum" here on Head-Fi but I don't venture into that wasteland too often... 
	

	
	
		
		

		
		
	


	



  
 All my readings and understandings are that a properly working amplifier with minimal distortion and a flat response curve has absolutely zero effect on the perceived sound stage, so I was just trying to wrap my head around how a driver tube of one type for example from different years or manufacturers could even affect it? Since the tube is just a simple signal amplifier that cannot do any type of processing except increase the signal level of the audio sine wave. If all of the example tubes are manufactured to the proper electrical specification for that model, then they should in theory all have the exact same electrical characteristics.
  
 That said, I find it hard to believe a series of identical tubes could alter the sound stage of one piece of music.  
 No big deal just curious.


----------



## mordy

IMHO my personal experience is that different tubes throw different sound stages. Some are wider, some deeper, some even impart a sense of height. If it is a function of the tube, the electronics, speakers or synergy between them,I don't know.


----------



## hypnos1

trolldragon said:


> Hey @mordy, @gibosi and @MMMan
> 
> Thanks for all the opinions on Sound Stage guys, I realize it was really a question for the "Sound Science Asylum" here on Head-Fi but I don't venture into that wasteland too often...
> 
> ...


 
  
 Hi TD.
  
 You have indeed highlighted what we have been discovering for a good while now - and we are not the only ones, lol - ie the curious conundrum re the difference between THEORY and PRACTICE. Please forgive my highlighting of parts of your post, but there are a good few "IFs" involved. It seems that it's not very likely any two tubes even from the same batch - let alone different manufacturers - are going to be _identical, _and so could explain a certain difference in final sound output?
  
 There is definitely more going on than can (currently) be explained by technical theory, and which brings an unending fascination/wonder/JOY! to this rolling game. I'm sure there IS a big deal in here _somewhere!..._but in the meantime we shall relish the curiosity 
	

	
	
		
		

		
		
	


	




...


----------



## hypnos1

oskari said:


> He'll still have the date code to crack...


 
  
 You ain't kiddin', Oskari...the little beauties arrived today 
	

	
	
		
		

		
			





. M6 mean anything to you? And there's an X with the Z...
  
 Whatever, they are - of course! - the real thing. And what can I say?...for once I'm (almost) speechless - but I'll give it a try lol!
  
 Any misgivings I might have had re losing some of the Chatham's 'air' are now totally gone...these tubes have definitely kicked the (wonderful) Chathams out of the marital bed...and those shameless C3GSs have not complained one bit - infidelity reigns even in tube land! 
	

	
	
		
		

		
		
	


	




. Even with just a few hours' burn-in, everything that is said about them is NOT hype. FINAL proof (if it were needed!) that tubes are NOT 'just' a standardised vehicle for signal gain, having minimal effect on the overall sound. And given they are still electrically a 6AS7G, the difference between them and, say, your standard RCA is quite extreme - I use the term advisedly...
  
 Having just listened to what I now use as my main test for 'fullness', impact/excitement and handling of dynamic range - 'The Battle', from the original music soundtrack of 'Gladiator', which must be up there with almost anything Wagner churned out, and a monument to Hans Zimmer _and_ the sound engineer - I firmly believe that THIS time (sorry gibosi!) I just might have reached my own nirvana...for the nth time!! I know something else _might_ be brought to the table by an alternative to the C3GS, but with my couple now making such "beautiful music" together - not to mention the aesthetic factor - I am surely going to be VERY happy for a VERY long time...
  
 And so...my ULTIMATE set-up looks just so :...
  

  
 ps. And what of the used curved-bottomed-base GECs?...With just one good one (which seems to be wanting to develop a slight hum) to three dead ones, unfortunately things are not looking too rosy - I suspect that these tubes are not particularly long-lived ones...more's the pity! But who knows, I just _might_ get real lucky! Thank heavens I splashed out on this NOS pair - hopefully they should see me out, lol!
  
 Cheers and
  
 Happy rolling everyone...


----------



## MMMan

trolldragon said:


> Hey @mordy
> , @gibosi
> and @MMMan
> 
> ...




None of our amps are transparent and our tubes are non- linear transformers. We change tubes in an imperfect system and create unexpected differences across the tonal range. Plus, we are all using different tubes for L and R. Leads to large perceived differences.... In sound.

G


----------



## Oskari

hypnos1 said:


> You ain't kiddin', Oskari...the little beauties arrived today
> 
> 
> 
> ...


 
  
 Yes, that's probably the date code but it should consist of two letters. M is 1956. The second letter tells the month. You can read all about it in here (including the X).
  

http://www.tubecollector.org/cv-valves.htm


----------



## TrollDragon

Thanks @hypnos1 and @MMMan
  
 Many a great possibility in this wonderful hobby of audio.


----------



## superdux

hi forum,
  
 since the beginning my loudness poti(LDMKIII) has been scratching and it has gotten worse so that as i dialed in to turn up the volume a channel dropped out so i swished the dial back and forth until everything seamed fine. I hope it doesn't get worse with all the years but i guess i might find someone then to solder in a new potentiometer and some better parts.Is there a way of fixing this issue with a contact spray or something else?
  
 sorry for offtopic.


----------



## MIKELAP

superdux said:


> hi forum,
> 
> since the beginning my loudness poti(LDMKIII) has been scratching and it has gotten worse so that as i dialed in to turn up the volume a channel dropped out so i swished the dial back and forth until everything seamed fine. I hope it doesn't get worse with all the years but i guess i might find someone then to solder in a new potentiometer and some better parts.Is there a way of fixing this issue with a contact spray or something else?
> 
> sorry for offtopic.


 
 I would try a contact cleaner .just spray it in the whole in your pot and turn the knob 10 - 20 times worked for me .


----------



## hypnos1

oskari said:


> Yes, that's probably the date code but it should consist of two letters. M is 1956. The second letter tells the month. You can read all about it in here (including the X).
> 
> 
> http://www.tubecollector.org/cv-valves.htm


 
  
 Thanks, Oskari...on closer inspection that '6' must be a 'G' - they're not too clear lol! (Or are my eyes on the way out? 
	

	
	
		
		

		
		
	


	




).
  
 Thanks also for the gentle letting-down re the 'X'...and its meaning! I am not _too_ disheartened though, because it would appear to _me_ anyway that it simply didn't reach the ULTRA high spec required, but still above the 'commercial' grade (or am I deluding myself? 
	

	
	
		
		

		
		
	


	




).
  
 Whatever, with further burn-in and a good cross-section of my test music assailing my ears, they are delivering a leap in sound above even the 6SN7/7N7 to a degree over and above that of the C3G compared to the premium 6DJ8s...no mean feat, to be sure! The level of clarity, smooth richness, frequency range, 'holographic' soundstage is truly astounding. Not to mention (amongst other qualities) the most extended note decay I have _ever_ come across...DELICIOUS!.. How on earth such a difference can be the result of just another 'simple vehicle for signal gain' defies any arguments/explanations I have yet heard, lol...
  
 Cheers, from somewhere up in the stratosphere...


----------



## mordy

Hi,
  
 Presently burning in the Sylvania 5687 driver tube since I suspect that it is NOS. So far I have some 15 hours on it. With the Chatham 6080 power tubes I must say that this is the best sound I have experienced with the LD MKIII so far. Everything sounds just right with great clarity and super bass and treble and very musical. This combination manages to be extremely detailed without being analytical or etched. I can pick out an instrument in the background and focus on it and follow it throughout the recording. Micro details abound.
  
 There is a certain _glow_ and warmth to the music and everything sounds better. At the same time this setup is very sensitive to the recording quality, and I may have to adjust the tone controls according to the recording.. This tube complement is not "ruthlessly revealing" in that it highlights flaws in the recordings, but it does show them.
  
 Re the old argument about how much the power tubes add to the sound: In the LD MKIII manual it states: "The pre-amplification signal in the Little Dot MK III includes both the driver and power tubes.."
  
 I have the ability to shut off the heaters to the power tubes while they are mounted in place. Doing so lowers the volume so that the headphone jack on the LD puts out too low a signal to be usable, but my receiver can use it. I just need to turn up the volume two-three steps to get satisfactory volume. I don't fully understand what is happening, but it seems to me that I running my system on just one dual triode. The sound is good, but not fleshed out, and the bass and slam is lacking compared to when the power tubes are being activated. Think grape juice vs wine, or better yet, unsweetened grape juice vs your favorite wine.
  
 Now, depending on who you are, you could say that there definitively is a difference, or, in my case, an enormous difference.  Somebody wrote that the power tubes contribute 15% to the sound, but I find it hard to quantify it. But I do know that there is no question what I prefer between a glass of grape juice or a glass of Cabernet Sauvignon.
  
 Hard to tear yourself away from this sweet sounding system........


----------



## hypnos1

mordy said:


> Hi,
> 
> Presently burning in the Sylvania 5687 driver tube since I suspect that it is NOS. So far I have some 15 hours on it. With the Chatham 6080 power tubes I must say that this is the best sound I have experienced with the LD MKIII so far. Everything sounds just right with great clarity and super bass and treble and very musical. This combination manages to be extremely detailed without being analytical or etched. I can pick out an instrument in the background and focus on it and follow it throughout the recording. Micro details abound.
> 
> ...


 
  
 Hi mordy.
  
 'Power' tubes certainly do rule, OK!...so long as they're fed by really nice drivers lol -  and it looks like you and gibosi are using some pretty good'uns. Am sorely tempted to have a go, but now that I am also in 'sound nirvana', and I like the _look, _methinks that will have to be very much a 'backburner' job...(???!).
  
 Happy listening.


----------



## gibosi

mordy said:


> Presently burning in the Sylvania 5687 driver tube since I suspect that it is NOS. So far I have some 15 hours on it. With the Chatham 6080 power tubes I must say that this is the best sound I have experienced with the LD MKIII so far. Everything sounds just right with great clarity and super bass and treble and very musical. This combination manages to be extremely detailed without being analytical or etched. I can pick out an instrument in the background and focus on it and follow it throughout the recording. Micro details abound.
> 
> There is a certain _glow_ and warmth to the music and everything sounds better. At the same time this setup is very sensitive to the recording quality, and I may have to adjust the tone controls according to the recording.. This tube complement is not "ruthlessly revealing" in that it highlights flaws in the recordings, but it does show them.


 
  
 To my (old and worn out) ears, the Sylvania 5687WA is almost indistinguishable from the 1940's Sylvania 6SN7W and the sub-miniature Sylvania 7963. And as the Sylvania 5687 is cheap and plentiful, anyone who is willing to cobble together an external socket and heater power supply can experience one of the best tubes Sylvania ever made for very little money. And in my opinion, these three Sylvania tubes are among the very best ever made by any manufacturer.
  
 edit: typo


----------



## Nic Rhodes

have you tried a box plate E182CC, a very different style of presentation......? and plug and play for a 5687.


----------



## gibosi

nic rhodes said:


> have you tried a box plate E182CC, a very different style of presentation......? and plug and play for a 5687.


 
  
 I have tried a 1962 Heerlen-made E182CC. And yes, it has a very different style of presentation. It strongly reminds me of my 1960 Heerlen-made E188CC, with that rather bright and lush mid-range, With my HD700's, I prefer the slightly laid-back Sylvania mid range. But of course, this is my opinion, my ears and my gear.


----------



## Nic Rhodes

partner it with another phone and it is another tube that will find much favour. Holland, UK and US all made excellent box plate examples.


----------



## gibosi

I hear you... I would really like to hear the E182CC through a pair of HD650's.....


----------



## Oskari

hypnos1 said:


> Thanks also for the gentle letting-down re the 'X'...and its meaning! I am not _too_ disheartened though, because it would appear to _me_ anyway that it simply didn't reach the ULTRA high spec required, but still above the 'commercial' grade (or am I deluding myself?
> 
> 
> 
> ...


 
  
 You are perhaps reading too much into it. I think it means that the valve bypassed the formal qualification approval process, perhaps they didn't even have test specifications for the type at the time.
  


> When approval has been given for the use of a valve in MDAP equipment by the Director of Electronics Research and Development (Air) but that valve has not received Qualification Approval the letter X shall be marked on the valve as if it were the appropriate Qualification Approval letter.


 
  
 Any other interpretations?


----------



## hypnos1

oskari said:


> You are perhaps reading too much into it. I think it means that the valve bypassed the formal qualification approval process, perhaps they didn't even have test specifications for the type at the time.
> 
> 
> Any other interpretations?


 
  
 Hi O.
  
 I like _your_ interpretation better, lol! 
	

	
	
		
		

		
			





...the last bit - "as if it were..." doesn't show on the page I get - or did you add that, mon ami?!! 
	

	
	
		
		

		
		
	


	




...
  
 Cheers...
  
 ps  These tubes just keep getting better and better...for a while I was beginning to worry that the extra bass and mids might just be taking the edge off certain treble instruments, but now I realise that they are being resolved with more subtle delicacy and range, and that previously I was being seduced by their _apparent_ magical quality. These babies are doing quite a job of re-educating my assessment/appreciation of what is entering my ears...but methinks I've run on more than enough about their qualities, lol!


----------



## Oskari

hypnos1 said:


> I like _your_ interpretation better, lol!
> 
> 
> 
> ...


 
  





 No, I didn't. It's there in Section 4.
  

http://www.tubecollector.org/documents/k1001/section4.pdf


----------



## hypnos1

oskari said:


> No, I didn't. It's there in Section 4.
> 
> 
> http://www.tubecollector.org/documents/k1001/section4.pdf


 
  
 Ah so...the answer lies in Section 4..
	

	
	
		
		

		
		
	


	




...I only read the first page of the (first) link.That 'last bit' makes the statement _much_ more encouraging lol!
  
 Cheers!


----------



## i luvmusic 2

If you install a MONO attenuator instead of STEREO would it work?


----------



## TrollDragon

If you used two mono attenuators...
http://www.dact.com/html/attenuators.html


----------



## i luvmusic 2

trolldragon said:


> If you used two mono attenuators...
> http://www.dact.com/html/attenuators.html


 
 WOW they look expensive compared to this,I think i got rip-off for this.


----------



## i luvmusic 2

I don't usually believed in Burn-in except for tubes but for this Attenuator the sound improved over one hour period i was playing it without listening,Then i picked up the HP and give it a listen the compressed sound disappeared compared when i just installed it and listened to it i hate the PoS but now i changed my mind it's actually not that bad no more slight channel  imbalance i used to hear and the background is even quieter.Whatever this thing is STEREO or MONO it's not that bad.


----------



## mordy

Hi,
  
 Wanted to talk a little bit about my hot tubes - a Sylvania 5687 driver tube and two Chatham 6080 power tubes. I have an inexpensive digital thermometer and decided to measure the tube and amplifier temperatures for fun, or shall we say trepidation...
  
 Turns out that I went away and forgot to shut off my rig. It had been running for 30 hours non stop when I returned, , and I was a little nervous about it, especially since Messrs Zhe Zhe and Yang warn against running the amp for more than 8 hours at a time. Obviously this refers to a stock amp using 6N6P and 6AK5 tubes, and not a fan cooled modified amp running two 2.5A room heaters in an air conditioned room.
  
 Anyhow, nothing untoward happened. Testing conditions: Room temperature 70-73F
  
 Temp of transformer housing: 83F
 Temp of amp chassis measured near tube sockets: 74F
 Temp of power tube on top: 117F
 Temp of power tube in the middle of glass envelope (previously determined to be a hot spot by inadvertently touching by finger resulting in a burn): 175F
 Temp of driver tube in the middle of glass envelope:115F
  
 After 45 hours I think that the Sylvania tube is burnt in - sound is delicious. Now I am burning in the bronze plate TS. Does anybody know what the advantage is of bronze plates?


----------



## TrollDragon

i luvmusic 2 said:


> WOW they look expensive compared to this,I think i got rip-off for this.


You didn't get ripped off for that attenuator, like I mentioned before you bought it, you get what you pay for... The Dact Attenuators are 10X the price of that one.


----------



## i luvmusic 2

I gotta admit changing the POT/ATTENUATOR can make a deference in sound it's either make it more noisy or a lot quieter.For fun i swapped the Attenuator from crack to LD 1+ Attenuator and CRACK very quiet background For LD 1+ and attenuator they suck big time noisy,could it be the LD 1+ is more sensitive Amp?


----------



## TrollDragon

Same value between the pot and attenuator? How is it noisy?


----------



## i luvmusic 2

What about GOLDPOINT attenuators anyone have used them?


----------



## i luvmusic 2

trolldragon said:


> Same value between the pot and attenuator? How is it noisy?


 
 No idea but it's noisy on LD 1.


----------



## i luvmusic 2

I would like use my MK III as a Pre-amp but i don't know which volume control i need to use to control the volume level.My set-up as follow DAC( no vol. control)  to MK III to Amp.Thanks!


----------



## TrollDragon

I would use the Amplifiers volume control, unless they are just a pair of mono blocks then use the LD's control.

Goldpoint Attenuators cost more than the LD I+ so it's up to you... I personally don't like 23/24 step attenuators as there is always a spot on them where one notch it to low and the next notch it to much. Now MIKELAP has a 48 step in his Burson, a much nicer control.

There are 68 and 79 step controllers out there but hard to find and way too much money for the application.

You should put in one of the motorized Alps with a remote, that would be a nice control.


----------



## TrollDragon

i luvmusic 2 said:


> No idea but it's noisy on LD 1.


Then it is either not the correct value for the LD or connected wrong, there is no difference between them. Basically one has continuous resistance and the other is a switched resistance.


----------



## i luvmusic 2

trolldragon said:


> I would use the Amplifiers volume control, unless they are just a pair of mono blocks then use the LD's control.
> 
> Goldpoint Attenuators cost more than the LD I+ so it's up to you... I personally don't like 23/24 step attenuators as there is always a spot on them where one notch it to low and the next notch it to much. Now MIKELAP has a 48 step in his Burson, a much nicer control.
> 
> ...


 
 No i don't intend to use the Goldpoint in LD 1+,So i need to set the amp volume to MAX and used the LD's pot.THNAKS!


----------



## i luvmusic 2

I found this at Patrsconnexion ALPS *100K*, Blue Velvet Motorized Volume Pot.Is this the kind of pot that need a remote?


----------



## MIKELAP

i luvmusic 2 said:


> I found this at Patrsconnexion ALPS *100K*, Blue Velvet Motorized Volume Pot.Is this the kind of pot that need a remote?


 
 Parts Connexion is where i got my Khozmo 50k attenuator .


----------



## i luvmusic 2

mikelap said:


> i luvmusic 2 said:
> 
> 
> > I found this at Patrsconnexion ALPS *100K*, Blue Velvet Motorized Volume Pot.Is this the kind of pot that need a remote?
> ...


 
 How do you like the Khozmo?Did you hear a deference in sound?I know i did hear deference is sound after i installed this schiity attenuator.Thanks!


----------



## i luvmusic 2

IMO by using a attenuator the sound is more balance.Only thing is mine sounds like it lack of Bass and details.


----------



## i luvmusic 2

Sorry for all this ATTENUATOR Talks i'am trying to gather as much information i can get before my little finger hit the buy and check out button.


----------



## MIKELAP

i luvmusic 2 said:


> How do you like the Khozmo?Did you hear a deference in sound?I know i did hear deference is sound after i installed this schiity attenuator.Thanks!


 
 Just remembered in the Burson Conductor thread RUBY TIGER  has a Khozmo attenuator in the amp he has the modded Conductor but the model before mine PCX says the changes were cosmetic only on mine you might use the SEARCH FUNCTION i remember him commenting about it


----------



## i luvmusic 2

mikelap said:


> i luvmusic 2 said:
> 
> 
> > How do you like the Khozmo?Did you hear a deference in sound?I know i did hear deference is sound after i installed this schiity attenuator.Thanks!
> ...


 
 Thank You!


----------



## gibosi

Today, while checking out what's new on eBay, I found 
  
 "1 x 5687 to 6AK5 tube adapter socket converter"
  
 http://www.ebay.com/itm/1x-5687-to-6AK5-tube-adapter-socket-converter-/301276665208?
  
 And I am thinking What? How?
  
 As the 5687 is a double triode and the 6AK5 is a single pentode, perhaps this adapter is simply connecting one of the triodes and leaving the other one disconnected.... Reminds me of the way we first started running 6DJ8's, but perhaps considerably more elegant. lol


----------



## mordy

This seems a bit of an overkill since you would need two adapters to convert two tubes into 6AK5 pinout. Personally, I would like to see a one piece bridge style adapter that allows one dual triode to be plugged into the two driver tube sockets in the LD MKIII. Judging from the price of the two 5687 to 6AK5 adapters for around $60 I think that I will stick to a breadboard and two Vector adapters.....
  
 The 5687 tube continues to amaze, and I have now burnt in the Tung Sol bronze plate tube. Here is a close-up of the bronze plate - the color looks like military camouflage:
  

  
 Before I will compare this tube to my Sylvania 5687, I am going to explore another Tung Sol black plate tube (on the left):

  
 The preliminary impression of the TS bronze plate tube is that the bass goes lower (room shaking) and has more punch than the Sylvania, but overall the tube seems less sweet and less involving than the Sylvania. Need to compare them back to back for a final conclusion.....
  
 So far I have not been able to find any reference to bronze plates. There is an opinion (myth?) that black plate is better in vacuum tubes, but I cannot find any information on bronze plates.


----------



## gibosi

I have recently learned that an LD running 6AS7 output tubes has died. While it is not clear that the 6AS7s were the cause, given the amount of current these tubes draw, they should be considered the prime suspect. For those running, or planning to run 6AS7's, following Mordy's example and using external cooling fans should be strongly considered. However, in my opinion, the safest and best practice is simply not to us 6AS7's in the Little Dot.
  
 But remember, there are lots of wonderful 6SN7's that are perfectly safe to use. Plus the 5687, 7044 and 7119/E182CC are all safe. On paper the 5687 and 7044 would seem to have the most promise, with .9amp heaters. I hope someone will give these a try and tell us. 
  
 Be careful out there....


----------



## lemonjelly

gibosi said:


> I have recently learned that an LD running 6AS7 output tubes has died. While it is not clear that the 6AS7s were the cause, given the amount of current these tubes draw, they should be considered the prime suspect. For those running, or planning to run 6AS7's, following Mordy's example and using external cooling fans should be strongly considered. However, in my opinion, the safest and best practice is simply not to us 6AS7's in the Little Dot.
> 
> But remember, there are lots of wonderful 6SN7's that are perfectly safe to use. Plus the 5687, 7044 and 7119/E182CC are all safe. On paper the 5687 and 7044 would seem to have the most promise, with .9amp heaters. I hope someone will give these a try and tell us.
> 
> Be careful out there....


 
 Hi gibosi.  I've modded my mkIII pretty extensively at this point, and I have wondered how well the transformer would hold up with the current the 6AS7s draw.  I found with a config ish close to stock mkIII the 6AS7s would pull over 80mA per tube....  The mk IV I'd guess would be similar but slightly lower cos of increased plate resistors.  So total for the amp when I first put my 6080s in (with a 6SN7 driver) of around 170mA.  The transformer on the mkIII is rated 175v@0.1A, which is more than you'd ever pull with a mix of 6n6p power and ef95/91 driver tubes, but obviously with what I imagine would be the pull with a stock mkIII with 6AS7s you're probably pulling at least 1.5x the amount the transformer is rated for.
  
 The power resistors also will probably be out of spec with 6AS7s as power tubes, and so I wonder if they would degrade etc after a while (pulling 5w or so while being rated 5w).  As far as whoever has had the amp die, I'd expect it's likely the transformer, or else maybe the power resistors have burnt out?  Should be fixable anyway.
  
 To fix both problems and bring the amp to a safer point if using the 6AS7s the easiest method is probably to change the cathode bias resistor.  In the mkIII it's stock at 120ohm and 150ohm in the mk IV.  I found 660ohm dropped the current to about 60mA (so 130mA total for amp or less).  The only problem is the capacitor attached to the resistor is only rated @ 16v, and will now be pulling about 40v (from 10v or so with the old resistor).  So you'd also need to uprate that capacitor to ~50v or so.  The value of the capacitor doesn't need to be exact (it's 220uF but could be a bit lower or higher really).  Another way of doing it which might take less space and would probably improve the sound too, would be to use a voltage regulator (LM317 or TL783 are easy), and then you just need a resistor to set the current.
  
 More details in the other thread here http://www.head-fi.org/t/439449/little-dot-mk-iii-mods/135


----------



## i luvmusic 2

Here is the one that keep me busy for the past few weeks.


----------



## i luvmusic 2

Sorry for the loss! So one has died and one is just born.


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## edshull

That looks very, very cool. Can you give me specs?


----------



## edshull

I just upgraded from the LD +1 with Grado 125's, to a MKII with HiFiMan HE-400's. I rolled Voshkod 6ZH1P's, which I transferred over to the MKII.
  
 I expected a big impact, but in fact things sound a bit cloudier, and muted. The MKII isn't pushing out the volume level of the +1, even if when I swap back to the Grado's. 
  
 I'm letting them burn in a bit, and I'm thinking about increasing the gain. Any other suggestions? Anyone else go through this?


----------



## i luvmusic 2

I think it is cheaper to just buy the kit from Bottlehead than sourcing the parts specially for the transformer it can be difficult to find the exact one for the Crack.If you decide to do the kit get the CRACK and SPEEDBALL,changed the volume pot and that's it ignore the rest of the upgrade specially those big A55 Caps they don't give a lot of improvement.Most noticeable/big improvement is the Speedball.


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## gibosi

edshull said:


> I just upgraded from the LD +1 with Grado 125's, to a MKII with HiFiMan HE-400's. I rolled Voshkod 6ZH1P's, which I transferred over to the MKII.
> 
> I expected a big impact, but in fact things sound a bit cloudier, and muted. The MKII isn't pushing out the volume level of the +1, even if when I swap back to the Grado's.
> 
> I'm letting them burn in a bit, and I'm thinking about increasing the gain. Any other suggestions? Anyone else go through this?


 
  
 As I understand, the Grado 125 has an impedance of 32 ohms and the HE-400 has an impedance of 35 ohms. The 1+, being a hybrid, is specifically designed to drive low Z headphones such as these. The all-tube versions, MKII, III and IV, tend to do much better with high Z headphones. So I am not surprised that your MKII doesn't sound as good as the 1+ with either of these headphones.


----------



## gibosi

In light of lemonjelly's recent posting
  
 http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/7140#post_10803964
  
 I believe that even if you are using an external cooling fan, you are pushing your luck running 6AS7's. Eventually, either the transformer or the power resisters will likely fail. Therefore, unless you are willing to change out the cathode resisters/capacitors or replace the plate loads with SS CCS's, as suggested by lemonjelly, I strongly recommend that you do not run 6AS7's in your LD.


----------



## edshull

gibosi said:


> As I understand, the Grado 125 has an impedance of 32 ohms and the HE-400 has an impedance of 35 ohms. The 1+, being a hybrid, is specifically designed to drive low Z headphones such as these. The all-tube versions, MKII, III and IV, tend to do much better with high Z headphones. So I am not surprised that your MKII doesn't sound as good as the 1+ with either of these headphones.


 
 Thanks for the feedback. I purchased this combo because I had read others saying they had good luck with it for rock and jazz. I'll return them and move on to a different combo. Thanks for the info.


----------



## hypnos1

gibosi said:


> I have recently learned that an LD running 6AS7 output tubes has died. While it is not clear that the 6AS7s were the cause, given the amount of current these tubes draw, they should be considered the prime suspect. For those running, or planning to run 6AS7's, following Mordy's example and using external cooling fans should be strongly considered. However, in my opinion, the safest and best practice is simply not to us 6AS7's in the Little Dot.
> 
> But remember, there are lots of wonderful 6SN7's that are perfectly safe to use. Plus the 5687, 7044 and 7119/E182CC are all safe. On paper the 5687 and 7044 would seem to have the most promise, with .9amp heaters. I hope someone will give these a try and tell us.
> 
> Be careful out there....


 
  
 Hi gibosi - and everyone out there - thanks for posting the warning....sorry guys for not letting you know sooner. At the moment, it's a case of "it never rains but it pours" lol! And I have been checking and _re_-checking all other possible avenues - tubes/sockets/inputs/'phones + cable + connection at the amp before blaming the amp itself (or, rather, the probable culprit - the 6AS7Gs...or, rather, more accurately...MYSELF!! Looks like I have indeed pushed the poor thing one step too far 
	

	
	
		
		

		
			





).
  
 A _little_ curious as not the slightest hint (smell) of anything burning, or anything untoward as far as I can see inside (through the front panel opening, at least). I know the prime suspect has to be the 6AS7, but I suppose there is always the possibility of some other component giving out. I'm afraid I don't know enough about checking  the entire innards (safely!) to diagnose fully, so the safest bet has to be - as gibosi said - not to bother with this family of tubes. Which has at least answered the question of whether or not to have the LD repaired/modified...there is NO WAY I can give up my GECs - they are so much better than anything else I have used 'til now (despite their tendency towards slight hum and microphonics!). So I am looking to other pastures, my friends...and it truly saddens me, after all this time.
 In fact, my first (tongue-in-cheek) experiment is going to be to see just what a real cheap chap can do - ie a Little Bear P8 (with metal case), which uses a single 6N5P (6AS7 equiv) driven by a pair of 6N3Ps (which I hope to replace with adapter-modified C3gs, or if not, gibosi's and mordy's 5687s). And if no good, will have to raid the savings (once again!).
  
 Anyway, it looks like you won't have to put up with my (endless) rantings any longer, folks! And I am very glad most (sensible!) people didn't follow _my_ folly...not that _you_ , MORDY, are not sensible lol! Like me - and ilm2 - you were brave/insane enough to see how far we could go with our "Little Wonders". I just hope your baby doesn't succumb as mine has...GOOD LUCK! 
	

	
	
		
		

		
		
	


	




.
  
 So, I shall bid you all a fond farewell and state once more how much I have enjoyed your company and all that the past year has given me (especially my poor LD!!)...I wish you the very best with your own experiences in LD land...
	

	
	
		
		

		
		
	


	



  
 ps....Thanks, lemonjelly, for your info and advice...but I'm afraid I must pass on this one - thanks again, anyway.
  
 Cheers,
  
 Colin


----------



## i luvmusic 2

Sorry about your LD! If you are considering another AMP that uses 6AS7's may i suggest the BH Crack with Speedball these combo is very nice no need for the other expensive upgrades for this amp. You can ignore most of those upgrades just do the Speedball and volume pot (ALPS Blue Velvet) and you are good to go.Their are some for sale(Crack/Speedball/upgraded caps/Attenuator)) few weeks ago from UK and AUS if you find one for say US $600(Crack/Speedball) grab it that is a good deal for this Crack. I look at those little Bear  amp before the crack and figured out if i have to modify it and put in a case i will end up spending over $200+ that is why i end up with the Crack.Good Luck!


----------



## TrollDragon

No way! You mean those bigass honking caps didn't improve the sound any? I think I mentioned that somewhere...


----------



## lemonjelly

Sad to hear that it was your amp hypnos :/.  I remember reading about you finding the c3gs + tbh they're probably the first tubes I'll roll in once I've finished faffing around with the mods to the actual amp.  I'm pretty amazed that an amp has actually died really, I've made plenty of mistakes while modding + tried loads of different things, with the only real losses at this point being 2 voltage regulators and a cheap pair of headphones that I accidentally put 100v through (oops).  
  
 You're taking it well but then I suppose it's never that bad when it means more toys to play with in the future !
  
 If you ever change your mind about troubleshooting send me a PM (although I'd guess a few other members would also be useful/willing to help).


----------



## i luvmusic 2

trolldragon said:


> No way! You mean those bigass honking caps didn't improve the sound any? I think I mentioned that somewhere...


 
  Nope no schiit those big A55 Caps means no schiit to the amp if there is any effect very little that i don't notice it's more like a bragging rights,Hey i have those MUNDORF 100uf 400V M-CAP MKP Series Film Capacitor LOL
	

	
	
		
		

		
		
	


	




.These are my impressions about the film caps,Thought about it 
	

	
	
		
		

		
		
	


	




,bought it
	

	
	
		
		

		
		
	


	







,installed it
	

	
	
		
		

		
		
	


	










,then i listened to it
	

	
	
		
		

		
		
	


	



















What. But it's ok i ordered a aluminum volume knob this will definitely have a big impact of sound or maybe i should change the Fuse with a Audiophile Grade and replaced all the wires with silver wires or NNNNNNNNNNNNNNNNNN ofc wires.
	

	
	
		
		

		
		
	


	




  
  
 IMO the most essential upgrade for the CRACK are SpeedBall and the Volume Pot that's it this amp will make your HP sing's like you've never heard Before with these  2 upgrades.


----------



## mordy

Hi hypnos 1,
  
 Sorry to hear about your amp giving up. I can only remember one case when somebody had a fire in his amp. Seems that Little Dot repaired it without charge if I remember correctly, even after the warranty period. Why don't you explore the repair option?
  
 Like you, I can't see myself giving up the delicious sound I get with the 6080 Chatham 2.5A power tubes and 5687/7963 tubes. I have gotten so much listening pleasure out of this amp, not to mention all the fun in trying countless tubes and combinations in addition to learning a lot about tubes. And of course the benefit of the great, patient, polite and helpful guys on this forum. A number of guests to the blog commented on the outstanding civilized tone and helpfulness.
  
 Although I am perfectly happy with the Little Dot MKIII with all the mods, a "What If" is lurking in the back of my mind. Several of us have moved on to different amps, I think kvatco to the Glenn amp, and Mikelap to the Woo 2 amp. Artsi builds his own amps, i love music 2 went to the Crack/Speedball. I would like to ask you to continue to report and describe your quest for great sound. The trick is to get great sound without spending a couple of thousand dollars. Since we all have a similar frame of reference (LD amps) I find it very helpful to hear how the other amps people are using compare. Should I decide to upgrade in the future it will make it much easier what to choose.
  
 Yes, I finally found the 7963 Sylvania tube at my self imposed less than $8/tube price point. Presently burning it in, and it sounds extremely promising. If you want to try it, here is the Ebay link. My guess is that the seller has plenty of them, but he is only advertising one lot at a time. In order not to drive up the price, I would humbly suggest just one bid at the minimum. If somebody bid already,  just wait until the seller puts it up again a day later- this offer is the third time I've seen it.
  
 http://www.ebay.com/itm/5-x-7963-NOS-NIB-Sylvania-Subminiature-Frame-Grid-Twin-Triodes-Submin-6DJ8-/261559064756?pt=Vintage_Electronics_R2&hash=item3ce62298b4
  
 Good luck!


----------



## i luvmusic 2

Hi,
   Although i have the Crack now for few weeks i still listened to my MK III occasionally for comparison not like which one is a better amp but for tube preference.The LD MK III is bargain for what it can do,I or we drived this thing so hard and i'am impressed how it handled all those high current tubes we inserted to this amp.I still continue to run those 2.5A tubes but only for driver tube,Iv'e been using this type of tubes for sometime now without any Fan(with external power supply for driver and power tube heaters) the amp get a little warm  but not as hot compared to running all stock/plug and play tubes for MK III.
  I'am not trying to encourage anyone to run high current tubes i'am just giving my thoughts how wonderful this amp is.Thank You and be safe tube rolling!


----------



## gibosi

i luvmusic 2 said:


> Although i have the Crack now for few weeks i still listened to my MK III occasionally for comparison not like which one is a better amp but for tube preference.The LD MK III is bargain for what it can do,I or we drived this thing so hard and i'am impressed how it handled all those high current tubes we inserted to this amp.I still continue to run those 2.5A tubes but only for driver tube,Iv'e been using this type of tubes for sometime now without any Fan(with external power supply for driver and power tube heaters) the amp get a little warm  but not as hot compared to running all stock/plug and play tubes for MK III.
> I'am not trying to encourage anyone to run high current tubes i'am just giving my thoughts how wonderful this amp is.Thank You and be safe tube rolling!


 
  
 I would agree.... It is simply amazing what we have been able to do with our Little Dots. Simply amazing! 
  
 And I also agree that we should not encourage anyone to use 6AS7's either as drivers or as output tubes. The LD is designed for two output tubes drawing no more than 2.5A. Two 6AS7's draw 5.0A, or twice the design spec. And we now know, these tubes draw too much current and can cause the amp to fail. Following this rather simplistic line of thinking, the LD is designed for two driver tubes drawing no more than 1.0A. A single 6AS7 draws 2.5A, or _*two and half times*_ the design spec. So in my mind, it is very likely that used as a driver, a single 6AS7 will also draw too much current and may cause the amp to fail.
  
 That said, we have learned from lemonjelly that swapping out the cathode resisters in the output circuit can reduce the current enough to allow 6AS7's to be safely used as output tubes. Perhaps the factory-installed cathode resisters in the LD's driver circuit are sized adequately to allow a single 6AS7 to be used as a driver? I certainly don't know, but I strongly doubt it...
  
 My best advice: Do not use tubes that exceed 1.0A as drivers. Fortunately, this allows the use of all the double triodes we have tried (except 6AS7's), such 6DJ8's and 6SN7's, as well as ECC32's (.95A) and 5687's (.9A).
  
 Again... be careful out there.....


----------



## lemonjelly

gibosi said:


> I would agree.... It is simply amazing what we have been able to do with our Little Dots. Simply amazing!
> 
> And I also agree that we should not encourage anyone to use 6AS7's either as drivers or as output tubes. The LD is designed for two output tubes drawing no more than 2.5A. Two 6AS7's draw 5.0A, or twice the design spec. And we now know, these tubes draw too much current and can cause the amp to fail. Following this rather simplistic line of thinking, the LD is designed for two driver tubes drawing no more than 1.0A. A single 6AS7 draws 2.5A, or _*two and half times*_ the design spec. So in my mind, it is very likely that used as a driver, a single 6AS7 will also draw too much current and may cause the amp to fail.
> 
> ...


 
 Hi, I'm not really sure if there's much of a relationship between the heater currents + the likelihood of problems (obviously so long as you are using an external PSU).  The 6AS7 is just known as a very current hungry tube, if you look at the curves for them in comparison to 6SN7 you can see they just pull much higher currents from the power transformer, which is what causes the problems (max for 6SN7 ~ 16mA, max for 6AS7 ~ 200mA).  But as you say that can be fixed by changing the cathode resistors, or using a current regulator as plate load etc.  As before the transformer is rated on the housing @ 175/0.1A, so you have that 100mA available for the power/driver tubes if you want to stay in spec.  Of course saying that I'm listening to 2x6080s with a 6SN7 at the moment - and it sounds great - while pulling 130mA from the transformer.
  
 You could easily use a current regulator as plate load or as cathode bias and set them to 40-45mA for the 6AS7s to keep the amp in spec power wise.  I don't see why there would then be any problems running the tube in that case, but without modification I'd agree it's a bad idea.  I'd guess that as a driver it would be very likely (with the plate load of 33k vs 120/150 and higher cathode resistors) to be completely fine.  I'd assume that both sections as a driver for the 6AS7 would only pull 20-30mA (a complete guess as I haven't tried to work it out, but it would be much less than 60mA total) leaving 70-80mA for the power tubes, with 6n6ps only pulling about 20mA each.
  
 Anyway... this has definitely got me more interested in tube rolling again... the 5687s look interesting although I'm still really tempted by the c3gs...


----------



## mordy

Hi lemonjelly,
  
 Thanks for your explanation about the power draw of different tubes. I cannot say that I understand everything well because of my limited electronic background. However, I am also running two 6080's as power tubes, and presently a sub miniature 7963 as driver tube. Is my understanding correct that the 6080 tubes draw less current from the transformer than the 6AS7 tubes? I tried to look up the spec sheets and understand the curves and look for the max current draw but couldn't identify that information.
  
 Had in mind to look for two Chatham 6AS7 tubes but now it seems unwise to use them. Is it safer to use the Chatham 6080 tubes? With two computer fans drawing away hot air from them the amp runs only slightly warm, and I can let it run for many hours without it getting hot.


----------



## lemonjelly

Hmm it's an interesting question as to whether there's a difference.  I've only got a single pair of 6080WAs (Thomson) so I can't do any testing to find a difference between tubes.  With this tube I found they match the 6AS7 curve very closely (so at least with this 6080WA they appear to pull the current you'd expect of a 6AS7).  The datasheets have slightly different max dissipations, but the same recommended current ranges (125-150ma).  The only information I could find about differences in current between the types is from http://diyaudioprojects.com/mirror/members.aol.com/sbench102/inv6as7.html which might not transfer at all, as it's about inverted tubes and so appears to be talking about differences in grid specs between the tubes.  But it does suggest there might be large differences between tube types... so not sure really.  Going off that 6AS7s would be 1 group (normal current), 6080s and some 6AS7Gs another group (less), and then 6AS7s and 6080WCs in a third group (more).
  
 So you might be right in that the 6080 might pull less... and from that it would be best to avoid the 6080WCs (if what's in that article does transfer).  Just reading about what the different suffixes mean - W = rugged, A = military, B = airborne, C = super rugged (some used for pershing missiles apparently).


----------



## maidos

just got my yugoslavia 6hm5 and 6n6p for my mk2 and really love the sound. much punchier and detailed bass compare to stock tubes imo.  was worth tuberolling. cant wait to hear these out once i burn it after 100+ hours.


----------



## mordy

This morning I asked my friend the retired A-V engineer the question if 6AS7/6080 type tubes running on external power would affect the internal components of the LD amp to the point of causing damage.
  
 His answer was that he could not see such a relationship. The heat build up in the amp comes from the temperature of the tube, and this can controlled by external cooling.
  
 Perhaps hypnos 1's failure of one channel could be attributed to something else - just one opinion....


----------



## gibosi

This is not really about too much heat. As your friend points out, heat can be dealt with very easily by using cooling fans. This is about current. As I understand from lemonjelly's posts, in a stock LDIII, 6080's want about 80ma each, or 160ma for the pair. Adding a driver, the total is now up to about 170ma. However, the transformer in your LD is rated for only 100ma.  Drawing 170ma out of a transformer rated for 100ma is asking for trouble and it should come as no surprise if one day it fails.
  
 Therefore, in order to use 6AS7's and stay at or below 100ma, it is necessary to modify the circuit in order to reduce the current draw of these tubes to 40-45ma each, which with a driver, keeps the total draw within spec. In lemonjelly's own amp, he is running his 6AS7's at 60ma per tube, for a total draw of about 130ma. While still higher than the the transformer's 100ma rating, it appears that lemonjelly believes the risk is small enough to be tolerable. So to lemonjelly, do you see an advantage to running these tubes at 60ma rather than 40?
  
 Again, this is not a problem that can be solved by adding cooling fans. These tubes require circuit modifications to be used safely.


----------



## lemonjelly

You've caught me, I'm a risk taker at heart !  Or well that's a little bit of it.  The transformer has that as a rating, but it is self wound by LD (I think) so I'm not sure how accurate it would be (they didn't even really need 100mA for stock configs so they might have put a conservative rating on it).  As well I'd assume that it depends a bit on the heat that the transformer is exposed to - I've got mine on top of the case and it does get warm but not hot - so I'm not really worried about it, and 1.3x the rated current doesn't seem as bad as the 1.7x I had originally.  I'm also probably going to replace the toroid in the next month or so with 2xHammond transformers, so honestly for me the longevity of the transformer doesn't come into it so much.  As well of course I know for sure that all of the resistors/caps/whatever are all within specs, although I would think at 130mA there wouldn't be a problem with any of the stock LDs as far as that goes (@170ma I'd be more worried).
  
 For the 6AS7s where I've seen people discussing it, most have recommended 60mA as a minimum, so I'm assuming that if you ran it at lower than 60 the sound probably wouldn't be as good (but I haven't tried it, just had it at 80+ then reduced to 60 immediately).  A lot seem to recommend higher currents - up to 100mA - but obviously that's not an option at this point.  
  
 As far as what's caused the amp to fail for hypnos... we really don't know at this point.  I think it probably is linked to the transformer being run out of it's rating, or 1 of the resistors failing/drifting out of spec.  But it could be something completely different.  Really if people are happy that they are potentially doing something dangerous (and obviously that danger comes with good sound), then at least they're informed and can make the choice, and the changes aren`t that difficult if people don`t mind modding a bit.


----------



## hypnos1

Thanks EVERYONE for your messages of support and sympathy...this is one GREAT thread - especially the people in it, lol!
  
 lemonjelly.....your offer of advice/help is much appreciated. At the moment I shan't be taking that mod route, but many thanks anyway (I might get my local hi-fi shop to examine/diagnose the amp, if the cost is reasonable - I'm still not TOTALLY convinced it is actually due to the 6AS7Gs, even though they are the prime suspect...surely there would be at least a _hint_ of burning if a resistor/cap/transformer section were fried?).
          I don't know if this could have any bearing on what's happened, but some months back when I was temperature probing the cathode resistor, the probe slipped, touched the area above on the PCB and killed the sound. But after switch off and back on, all was well. And has(had!) been since, so probably coincidence? One other thing - as a final(?) check, I tried the pre-amp out and all I get is a very low-level distorted sound from the speakers - from BOTH, even with no tubes in the right channel (my headphone cable is soldered direct to the amp, but I unplugged it at the cups)...
	

	
	
		
		

		
			




  
  
 ilm2.....yes, I would have loved to give the Crack a try, but final prices here are still a bit high for my liking...an option for the future perhaps, depending on how the Little Bear performs, lol!
  
  
 mordy.....thanks for the link, but I have gone for a pair of early TS 5687s and a pair of "D" getter Raytheons - thanks again, anyways. Thanks also for your invitation to keep you all informed of progress with new equipment...mind you, you do realise this means y'all could have to put up with _more_ endless rantings, just when you thought you were free?! 
	

	
	
		
		

		
		
	


	




 It's going to be really interesting to see how the 5687s perform - especially if I manage to get my C3GSs to work (doubled up as per gibosi's helpful advice), and can then compare the two types...
  
         I am missing my LD so much (taking it well, lemonjelly? - not so sure!). But yes, new projects are good for taking the mind away from melancholy...plus, I have just realised I could always keep the beloved LD on the rack, rather than consigned to oblivion...as provider of the LEFT channel, with the Little Bear providing the RIGHT...my very own "dual" set-up lol?!! (I like the idea of being able to control volume level between channels...worth a try, perhaps...).
  
  
 Ah well, guys, thanks again for your condolensces...will keep you informed...


----------



## gibosi

lemonjelly said:


> ........Really if people are happy that they are potentially doing something dangerous (and obviously that danger comes with good sound), then at least they're informed and can make the choice, and the changes aren`t that difficult if people don`t mind modding a bit.


 
  
 This is a very good point. On the one hand, theoretically, pulling 170ma through a transformer rated for 100ma should be considered risky and dangerous. On the other, we really don't know the reason hypnos1's amp failed, and further, mordy and ilm2 have not experienced any problems running 6AS7/6080. And it could even be that mordy's fans are making a difference by keeping the transformer cool. Whatever, at least now, everyone should know the risks and can make their own decisions.
  
 Cheers


----------



## TrollDragon

gibosi said:


> ...
> And it could even be that mordy's fans are making a difference by keeping the transformer cool.
> ...


 
  
 The heat inside the case is not created by the tubes or the transformer.
  
 Resistors create heat and unless they are designed with heat sinks on them to dissipate the heat, moving air across the ones in the LD is just prolonging a possible chance for failure.
 There doesn't have to be smoke or fire or smell for a winding to open or a component to let go.


----------



## i luvmusic 2

Is it possible to change the wattage rating of a resistor to run cooler?
 In my case one of the resistor on the crack rated at 33K 10W can i change this to say 33K 20W if there is any resistor rated like this.
 This 33K 10W when it was still on the crack before the Speedball i accidentally touch that SoB and it is burning hot now i'am glad that is gone replaced by the SB.


----------



## lemonjelly

Hmm from the sounds of it it isn't the transformer hypnos (it just wouldn't get any power I would've thought if it was).  I'd still say it's probably the resistors in some part of the amp.  Before uprating some I had resistors being run over spec, and they didn't stop working, but kinda melted a bit instead (and I'm guessing went a bit higher resistance wise but didn't burn out).  One of them also melted enough that the connection broke but worked fine once I'd resoldered (was still waiting on the resistors to come).  So maybe it's something like that.  I'd hope it means that the cost will be in the diagnosis rather than in replacement parts anyway.
  
 I'd agree with the fan thing... the casing isn't connected directly to all the components but even for the transformer, if the casing is being helped by the fans cooling it, it won't be much help as the casing isn't geared to active cooling (no fins or anything).
  
 With the resistors, the higher the rating the cooler they should run, with the main reasons why you wouldn't uprate resistors always being size and cost (I think), as well as diff types of resistor only being available in specific power ratings.  If you put in a 20W it'll probably have a big heatsink - and so will take more space - but should run much cooler.


----------



## mordy

Once I was burning in a tube from the EF92 family and the amp got extremely hot - the hottest it ever got. Since it was designed for this type of tube, is there a way to find out how much current this type of tube draws?


----------



## TrollDragon

It would be on the data sheet for the tube.


----------



## mordy

Hi,
  
 Found the information for the current draw of the EF91 and EF92 families of tubes. These tubes are recommended for use in the Little Dot MKIII. Here are the values:
  
*The EF91 draws significantly more current (300mA) compared to the EF92 (200mA) and EF95 (175mA) families. *(The source is post #2 on this blog!)
  
 Am I correct that with a design parameter of 300mA  current draw the LD should be able to handle 6AS7 tubes?


----------



## mordy

Hi,
  
 Found the information for the current draw of the EF91 and EF92 families of tubes. These tubes are recommended for use in the Little Dot MKIII. Here are the values:
  
*The EF91 draws significantly more current (300mA) compared to the EF92 (200mA) and EF95 (175mA) families. *(The source is post #2 on this blog!)
  
 Am I correct that with a design parameter of 300mA  current draw the LD should be able to handle 6AS7 tubes?


----------



## gibosi

mordy said:


> Found the information for the current draw of the EF91 and EF92 families of tubes. These tubes are recommended for use in the Little Dot MKIII. Here are the values:
> 
> *The EF91 draws significantly more current (300mA) compared to the EF92 (200mA) and EF95 (175mA) families. *(The source is post #2 on this blog!)
> 
> Am I correct that with a design parameter of 300mA  current draw the LD should be able to handle 6AS7 tubes?


 
  
 There are essentially two circuits. One to supply current to the heaters and the other to supply current to actually run the amp. The values quoted above refer to the heater circuit. For the 6AS7, you are using an external heater power supply to provide 2.5 amps to heat the heaters. What is burning up resisters and perhaps killing transformers involves the other circuit. And again, the LD is designed for a maximum current of 100ma to actually run the amp, the driver and the output tubes. The 6AS7's want 80ma each, or 160ma for two. This excessive current may well damage the amp.


----------



## lemonjelly

Hi because it's interesting and it helps me to learn this stuff as well.. I drew some load lines on the valve curves to try and show what's happening:
  
 6AS7:
  

 6n6p:
  

  
 I've only really learnt all of this stuff in the last month, but I *think* this is right.  So basically the load line is for the plate resistance we're using (I was using 120ohm for the power tubes) and then I've plotted the cathode voltages that I have.  So if you change the cathode bias voltage (via changing the resistance or whichever method) then you move up and down the line.  If you change the plate resistance then the line becomes steeper if you decrease, and less steep if you increase.
  
 So you can see with the 6n6ps you move up and down from ~25ma, while with the 6AS7s you're moving down from over a 100ma.  The measurements aren't that exact... I just scribbled them down while modding so I wouldn't say the load line is that accurate, but it does to show what's happening.
  
 So if you wanted to get the current on the 6AS7s down to 40ma then you would increase the cathode resistance to:
 V = IR, ~65v = 0.04A * R, R = ~1600ohms.  And for that resistor you would need a rating of:
 P= VI, P = 65v *.04A = 2.6W so you'd need probably at least a 3W resistor.


----------



## hypnos1

gibosi said:


> There are essentially two circuits. One to supply current to the heaters and the other to supply current to actually run the amp. The values quoted above refer to the heater circuit. For the 6AS7, you are using an external heater power supply to provide 2.5 amps to heat the heaters. What is burning up resisters and perhaps killing transformers involves the other circuit. And again, the LD is designed for a maximum current of 100ma to actually run the amp, the driver and the output tubes. The 6AS7's want 80ma each, or 160ma for two. This excessive current may well damage the amp.


 
  
 Hi gibosi....It's certainly looking more like the resistors all the time, lol! - those in the Little Bear P8 to come look MUCH more up to the job...lovely fins on 'em, and TWO for the one 6AS7 (equiv)...pics below...
	

	
	
		
		

		
			




  


lemonjelly said:


> Hi because it's interesting and it helps me to learn this stuff as well.. I drew some load lines on the valve curves to try and show what's happening:
> 
> 6AS7:
> 
> ...


 
  
 Nice work, lj...I think the LD's is 1W...so the poor thing certainly has been working hard lol!...
	

	
	
		
		

		
		
	


	



  
 Anyway, just thought you guys might like to see the cheap chappie on its way...
  

  
 But mine will have the toroidal transformer...
  
 This metal-cased version should have innards like so....
  
  

  
 And...
  
 Are American "Dale" resistors good ones, as they are being made out to be?
  
 I DO like the look of those 2 finned ones, though!
  
 So, it's going to be VERY interesting to see what this baby can do, with my GEC 6AS7G driven by either my C3GSs - if possible - or a pair of 5687s in place of the 6N3Ps (whichever, I've got a bit of work on my hands! But looking forward to it, nonetheless...).


----------



## i luvmusic 2

What i'am interested in is this *DarkVoice 336SE.*


----------



## TrollDragon

i luvmusic 2 said:


> What i'am interested in is this [COLOR=333333]*DarkVoice 336SE.*[/COLOR]


I would go with the La Figaro 336C, looks much nicer and was my first choice before the MK IV.

http://www.yuking09.com/336c.asp


----------



## i luvmusic 2

trolldragon said:


> i luvmusic 2 said:
> 
> 
> > What i'am interested in is this *DarkVoice 336SE.*
> ...


 
 Are they the same amp in defferent  chassis?


----------



## TrollDragon

I don't know the history behind them both but they are the same design. I just liked the 336C's layout and looks better.


----------



## i luvmusic 2

What i don't like about the crack is by using 6SN7 it sucks not to my liking lack of power and details.I invested in 6AS7G/6080 and 6SN7 tubes for the crack but unfortunately 6SN7 and crack are no no for me that is why if i will get another amp i need something that is good for 6SN7 and 6AS7/6080 so my tubes are not going to be dust collector.I don't want to spend more $ on tubes i would like to use what i have,so far i have no choice but to get more 12AU7's i only have 4 and 2 of them i don't really like they sound flat/weak in bass.MK III with 6SN7 is wonderful that is why i have no plan on getting rid of this amp.


----------



## i luvmusic 2

trolldragon said:


> I don't know the history behind them both but they are the same design. I just liked the 336C's layout and looks better.


 
 I like the P2P wiring they are easy to work with than PCB's IMO that is.


----------



## superdux

hypnos1 said:


> Anyway, just thought you guys might like to see the cheap chappie on its way...


 
  
 Hi Hypnos,
  
 whats the name of the amp? I'm old, so i can hardly read the writing on the frontplate


----------



## genclaymore

Its Little dot


----------



## TrollDragon

That amp is the Little Bear P8.


----------



## gibosi

i luvmusic 2 said:


> What i don't like about the crack is by using 6SN7 it sucks not to my liking lack of power and details.I invested in 6AS7G/6080 and 6SN7 tubes for the crack but unfortunately 6SN7 and crack are no no for me that is why if i will get another amp i need something that is good for 6SN7 and 6AS7/6080 so my tubes are not going to be dust collector.I don't want to spend more $ on tubes i would like to use what i have,so far i have no choice but to get more 12AU7's i only have 4 and 2 of them i don't really like they sound flat/weak in bass.MK III with 6SN7 is wonderful that is why i have no plan on getting rid of this amp.


 
  
 You have tried 6SN7's in the Crack and they don't sound as good as they do in your MK III??? I am very surprised! The MK III uses two output tubes, whereas the Crack uses only one.... And I assume you are using two 6AS7's in the MK III? And if so, I wonder if that could be the difference......


----------



## kvtaco17

i luvmusic 2 said:


> What i don't like about the crack is by using 6SN7 it sucks not to my liking lack of power and details.I invested in 6AS7G/6080 and 6SN7 tubes for the crack but unfortunately 6SN7 and crack are no no for me that is why if i will get another amp i need something that is good for 6SN7 and 6AS7/6080 so my tubes are not going to be dust collector.I don't want to spend more $ on tubes i would like to use what i have,so far i have no choice but to get more 12AU7's i only have 4 and 2 of them i don't really like they sound flat/weak in bass.MK III with 6SN7 is wonderful that is why i have no plan on getting rid of this amp.


 
 Get a Glenn OTL amp...


----------



## hypnos1

superdux said:


> Hi Hypnos,
> 
> whats the name of the amp? I'm old, so i can hardly read the writing on the frontplate


 
  
 Hi superdux...yep, TD's right - Little Bear P8. They come in different flavours...acrylic "open" jobs, or metal-cased (silver or black) with the option of toroidal transformer for just another $10.
  
 Wish there was more info out there from users...at least I shall be able to assess without any preconceptions, lol! (But I will be VERY harsh in my comparison to the ill-fated experiment with the MKIV SE + C3GSs + GEC 6AS7Gs!!...this poor little thing might be doomed before it's even arrived 
	

	
	
		
		

		
		
	


	




...).
  
  
 Despite fear of repetition, the more I read other peoples' feedback on different amps and tube combos, the more I am convinced that the partnership of C3G and 6AS7G (_especially_ the Chatham, and even more so, the GEC family versions) is a truly wondrous one...so long as you have an amp you can put them in lol!).
  


kvtaco17 said:


> Get a Glenn OTL amp...


 
  
 Hey, kvt, you payin'?...If so, put me down for one 
	

	
	
		
		

		
		
	


	




.


----------



## TrollDragon

If cash was not a issue then there would be a Line Magnetic 219ia at the house with headphone taps on the speaker output.


----------



## superdux

@hypnos1 it's so cute! can you roll some of your old tubes in it?


----------



## hypnos1

superdux said:


> @hypnos1 it's so cute! can you roll some of your old tubes in it?


 
  
 Hi again s.
  
 That's one reason why I'm giving this little amp a try...it will take my fabulous GEC 6AS7G, which appears to have been the downfall of my MKIV SE lol!
  
 As for drivers, the 6N3Ps will be consigned to the bin - even modest US 5670s would be far better, it seems. Or even a pair of my previous 6N23Ps, with adapters (which I would probably have to make myself).
 However, the 6AS7Gs deserve much better than these, so (with some advice from gibosi, but without danger of blame lol!) I shall be attempting to cobble together a set-up that will use 2x C3gs(S version) per 6N3P, and see just what happens 
	

	
	
		
		

		
			





...I have also got some 5687s that gibosi and mordy have found to be excellent tubes, but which also will need some major mods - external heater supply plus home-made adapters.
  
 So unfortunately, if one is not prepared to go this route, the only real alternative would appear to be a good 5670...but they do however seem to be quite a good tube.


----------



## i luvmusic 2

gibosi said:


> i luvmusic 2 said:
> 
> 
> > What i don't like about the crack is by using 6SN7 it sucks not to my liking lack of power and details.I invested in 6AS7G/6080 and 6SN7 tubes for the crack but unfortunately 6SN7 and crack are no no for me that is why if i will get another amp i need something that is good for 6SN7 and 6AS7/6080 so my tubes are not going to be dust collector.I don't want to spend more $ on tubes i would like to use what i have,so far i have no choice but to get more 12AU7's i only have 4 and 2 of them i don't really like they sound flat/weak in bass.MK III with 6SN7 is wonderful that is why i have no plan on getting rid of this amp.
> ...


 
  
 Not to my ears Crack with 6SN7 not for me prefered 6SN7 and MK III,Nope 3 6SN7's for comparison but most of the time it's 2 6SN7 1 6AS7G for the Mk III.


kvtaco17 said:


> i luvmusic 2 said:
> 
> 
> > What i don't like about the crack is by using 6SN7 it sucks not to my liking lack of power and details.I invested in 6AS7G/6080 and 6SN7 tubes for the crack but unfortunately 6SN7 and crack are no no for me that is why if i will get another amp i need something that is good for 6SN7 and 6AS7/6080 so my tubes are not going to be dust collector.I don't want to spend more $ on tubes i would like to use what i have,so far i have no choice but to get more 12AU7's i only have 4 and 2 of them i don't really like they sound flat/weak in bass.MK III with 6SN7 is wonderful that is why i have no plan on getting rid of this amp.
> ...


 
 Too much for me..Thanks!


----------



## i luvmusic 2

My budget is not more than $351.99 so you guys and girls can recommend me an amp that use 6SN7 and 6AS7G.What i have in mind is the DV 336C but i don't know if it can use 6SN7.Thanks!


----------



## i luvmusic 2

Wow! found this Burson *Conductor SL9018 from Parts connexion for $749 it's on sale half price.*


----------



## i luvmusic 2

trolldragon said:


> If cash was not a issue then there would be a Line Magnetic 219ia at the house with headphone taps on the speaker output.


 
 I think just to buy one of those tubes will put me over budget already.


----------



## TrollDragon

i luvmusic 2 said:


> Wow! found this Burson *Conductor SL9018 from Parts connexion for $749 it's on sale half price.*


That is a great price on that amp, it has no Line/Pre Out's so it is just a headphone amp. I found the ESS DAC (9018) very sterile and analytical sounding. The TI DAC is a lot warmer and much more fun sounding, so you could swap DAC's to suit your taste.


----------



## TrollDragon

i luvmusic 2 said:


> I think just to buy one of those tubes will put me over budget already.


Yeah there is a few grand worth of tubes there...


----------



## gibosi

hypnos1 said:


> So unfortunately, if one is not prepared to go this route, the only real alternative would appear to be a good 5670...but they do however seem to be quite a good tube.


 
  
 If you can figure out how to roll 5687 in the Little Bear P8, in the same way, that is, with adapters and an external heater PS, you should be able to roll 6SN7, ECC40, E80CC and E81CC.  Further, the sub-miniatures and the 6DJ8 would require adapters, but not an external PS. Roll on!


----------



## i luvmusic 2

trolldragon said:


> i luvmusic 2 said:
> 
> 
> > Wow! found this Burson *Conductor SL9018 from Parts connexion for $749 it's on sale half price.*
> ...


 
 So this amp will allow you to roll op amp?It is probably more expensive than tube rolling.


----------



## i luvmusic 2

I let my kid listened to the Crack and MK III for a whole day today while i was at work,My kid said to me Dad can  i keep the Crack?I asked why? then the answer was because the crack it sounds like you're in the middle of everything i can hear every instrument playing in the background.Then i asked what about the MK III?the answer was will it sound good but it's difficult to tell where are the instrument playing in the background and it sounds everything is  away from you.I don't know what this kid is describing could it be the Soundstage and instrument separation/clarity?I have to agree the Crack to my ears are more forward sounding than the MK III and with the crack it's easy to pinpoint the location of the instrument.But then this kid told me at the end BTW dad i dropped two of the tubes on the floor and they are broken
	

	
	
		
		

		
		
	


	




.So where are the broken tubes?it's garbage day today so it's in the garbage truck(good answer) i just smile and said that's ok,only to find out two of the 6AS7G CHATHAM was broken.Lessons learned for me never let your kid/s used your tube amp unattended.Once my wife broke a tube pins on the MK III i don't know how she managed to do that.These two in my life they're costing me money every time they used my AMP.


----------



## superdux

@i luvmusic 2 i hate you for posting that burson conductor offer!!!!$%%&&&// damn i wish i would have some money spare, i probably would have bought it straight away without even reading any reviews lol.
 And you better put a metal cage around your amp with a warning sign "Beware High Voltage!"


----------



## i luvmusic 2

I hear you for that price it's tempting but i don't have enough $ i have other plans for my limited $ i would like to get the HD65X.
 Beware high voltage sign and electric fence.


----------



## MIKELAP

Quote: 





trolldragon said:


> If cash was not a issue then there would be a Line Magnetic 219ia at the house with headphone taps on the speaker output.


----------



## TrollDragon

You guys just know you want that Conductor SL don't you, it's such a great amp!

  

  
  
 ESS DAC & TI DAC.

  

 There are no op amps in the SL, it's all FET's.


----------



## MIKELAP

trolldragon said:


> You guys just know you want that Conductor SL don't you, it's such a great amp!
> 
> 
> 
> ...


 
 Sold!


----------



## MMMan

mmman said:


> So, here is my 'blast from the past': Tonight I fell in love with my LD Mk IV all over again!!
> 
> My 6SN7 adaptors arrived tonight, so I finally got to try some totally new power tubes!! The only ones I have right now are 1955 Sylvania 6SN7GTB black plates ($25)... but wow, they sound beautiful!! Biggest improvement from any tube (driver or power) I have put  into this preamp!! I am deft going to stay and play with 6SN7s for a while. I have some Russians on the way and I found a great price on some Mickey Mouse ear Tung Sols ($22)...
> 
> ...




Hi everyone!

As I mentioned in this previous post, I have been playing in the world of 6sn7 power tubes. Wow, some of them are just amazing in the LD. I still like the drivers I mention above with rhe 6sn7s, but my new favourite power tube is the Tung Sol 6sn7gt 'Mickey Mouse Ears'. Beautifully clean, great highs and great clean bass. Strongly recommended on all the 6sn7 threads... And if you do some reading and look for rebranded tubes, you can find a great pair for $20! I have lots more 6sn7s on they way, so I will be having fun with this tube for quite a while.

BTW, does anyone know if the current to the heater filament in the LD IV is AC or DC? I want to get or make a step up transformer to run 12sn7s..... Identical to 6sn7s except 12v heaters.

Cheers


----------



## MMMan

PS - nice new amp TD!


----------



## TrollDragon

mmman said:


> PS - nice new amp TD!


Thanks but that was a loaner from Burson on their trial/demo program... Well above my pay scale. 

The LD filament power is AC from the transformer.


----------



## i luvmusic 2

trolldragon said:


> You guys just know you want that Conductor SL don't you, it's such a great amp!
> 
> 
> 
> ...


 
 How does it sound with your DT880?If i get this amp i can kiss the HD650 goodbye for now no more cash leftover
	

	
	
		
		

		
		
	


	




.Thanks!


----------



## i luvmusic 2

mikelap said:


> trolldragon said:
> 
> 
> > You guys just know you want that Conductor SL don't you, it's such a great amp!
> ...


 
 Hi Mikelap,
  Is that the Burson you have how does it sound compared to the tube amp?A little bright i assume.Thanks!


----------



## i luvmusic 2

My original budget was for the CRACK and HD650 now minus the crack  i just have enough for the HD650 but with this BURSON it's driving me nuts.I just email Partsconnexion and they said this only one time sale.


----------



## Rossliew

Is the Soloist suitable for high impedance cans like the Senns?


----------



## TrollDragon

rossliew said:


> Is the Soloist suitable for high impedance cans like the Senns?


From what I have read, the Soloist will drive just about any headphone perfectly.


----------



## MIKELAP

rossliew said:


> Is the Soloist suitable for high impedance cans like the Senns?


 
 I use my Conductor with Senns hd800 and they sound great especially with classical but not all tunes are created equal so some sound better than others for example Doug Mcleod   http://www.hdtracks.com/there-s-a-time-134528 and  Daft Punk great bass on that album   http://www.hdtracks.com/random-access-memories           Also Muse 2nd law sounds good             http://www.hdtracks.com/the-2nd-law.                                                                                                                                                                                                                                        Best is to read the Senns hd800 thread . Here is a review and a quote from that review of the Bakoon amp versus  the Conductor which uses the Soloist amp but it has 4 watts per channel compared to 2 watts/channel for Soloist SL and Soloist SL like TD said is only a HP amp no preamp. 
.                    http://headmania.org/2013/06/06/bakoon-hpa-21-review/


----------



## Rossliew

mikelap said:


> I use my Conductor with Senns hd800 and they sound great especially with classical but not all tunes are created equal so some sound better than others for example Doug Mcleod   http://www.hdtracks.com/there-s-a-time-134528 and  Daft Punk great bass on that album   http://www.hdtracks.com/random-access-memories           Also Muse 2nd law sounds good             http://www.hdtracks.com/the-2nd-law.                                                                                                                                                                                                                                        Best is to read the Senns hd800 thread . Here is a review and a quote from that review of the Bakoon amp versus  the Conductor which uses the Soloist amp but it has 4 watts per channel compared to 2 watts/channel for Soloist SL and Soloist SL like TD said is only a HP amp no preamp.
> .                    http://headmania.org/2013/06/06/bakoon-hpa-21-review/


 
 Thanks Mike. I have read pretty good reviews of the Soloist as an amp but I've always believed it to be more suited for low impedance headphones. Thanks for the links too.


----------



## i luvmusic 2

My BURSON dreams are gone because of this.


----------



## MIKELAP

i luvmusic 2 said:


> My BURSON dreams are gone because of this.


 
 ???????????????


----------



## i luvmusic 2

The Burson have no pre out so no no for me,I have to admit HD 650 and CRACK is really really good very relaxing.I can see the HD800 in my future.


----------



## TrollDragon

Only the "SL" versions have no Line/Pre Out, all the rest do.... :rolleyes:


----------



## i luvmusic 2

Those Burson's with pre out are $1,500 and up no thanks! for that money i will get a S.E.X.


----------



## i luvmusic 2

How do you test a tube for short without a tube tester is this possible?Thanks!


----------



## kvtaco17

Plug the tube into an amp...
Turn amp on...
Pray to little baby Jesus...
If it pops you didn't pray hard enough...

Repeat


----------



## i luvmusic 2

Will it pop with a bright blue light,need  to pray more...........
 THANK YOU!


----------



## mordy




----------



## MIKELAP

i luvmusic 2 said:


> How do you test a tube for short without a tube tester is this possible?Thanks!


 
 Which tube is it ,and pray you live in Montreal.


----------



## i luvmusic 2

mikelap said:


> i luvmusic 2 said:
> 
> 
> > How do you test a tube for short without a tube tester is this possible?Thanks!
> ...


 
  G.T.C.(Chatham)6AS7G and 3 RCA 6SN7's,It's too bad i'am from GTA
	

	
	
		
		

		
		
	


	




.
 The 3 RCA 6SN7 i got them some time ago from eb4y auctions and for got about them till today i found them they are defective i believe 2 of them during start up they spark(blue light) and the sound is distorted and low 1 only one channel works and the GTC at first started with low on one side until both channel is low and it pops during start up i never plug these tubes since i got them they just spark and one channel does not work with the LD's and CRACK.THANK YOU!


----------



## i luvmusic 2

I will go to the Flea market tomorrow and see if i can find someone with a tube tester.


----------



## MIKELAP

i luvmusic 2 said:


> I will go to the Flea market tomorrow and see if i can find someone with a tube tester.


 
 To bad i could of tested  them for you


----------



## i luvmusic 2

mikelap said:


> i luvmusic 2 said:
> 
> 
> > I will go to the Flea market tomorrow and see if i can find someone with a tube tester.
> ...


 
 Very nice! I didn't know you have a tube tester OK i'am moving to Montreal LOL.
	

	
	
		
		

		
		
	


	




Thank you for the offer!


----------



## kvtaco17

i luvmusic 2 said:


> I will go to the Flea market tomorrow and see if i can find someone with a tube tester.


 

 I would try hitting up a music store that sells guitar amps... Most of them that service amps have a tester on hand.


----------



## i luvmusic 2

kvtaco17 said:


> i luvmusic 2 said:
> 
> 
> > I will go to the Flea market tomorrow and see if i can find someone with a tube tester.
> ...


 
 I will try that Thanks!


----------



## kvtaco17

i luvmusic 2 said:


> I will try that Thanks!


 
  
 It's what I do when I have tubes I can't test... stupid 6336's...


----------



## i luvmusic 2

If they are not good it's ok i will turn them like these.


----------



## MIKELAP

i luvmusic 2 said:


> If they are not good it's ok i will turn them like these.


 
 Burn baby burn!


----------



## TrollDragon

i luvmusic 2 said:


> Very nice! I didn't know you have a tube tester OK i'am moving to Montreal LOL. Thank you for the offer!


 
Does VIA still run the Bullet Train to Montreal? You could be there in an hour and a half...


----------



## i luvmusic 2

It would be nice to go back in montreal but i'am busy so no time to go back.Last time i was there 2001.


----------



## hypnos1

Well guys, looks like you just might not be free of me after all lol!
  
 Have decided to let my local repair man, who does a lot of work on old "valve" radios, have a look at my LD. So hopefully we will get some idea of just what happened and what needs to be done...as per lemonjelly's postings. My feller mentioned anode resistors and possible caps/coupling caps as well as cathode resistors...it looks like he's gonna give it a good going over at least. And if the bill isn't _too_ steep, I just might have my beloved amp back in my arms!
  
 Too bad the Little Bear is on its way, but it should be a fun project and a not-too-expensive one...
  
 Will keep you all posted...


----------



## i luvmusic 2

Will i was in luck that i found a guy that have a tube tester but on the other hand my tubes were tested shorted and low.
	

	
	
		
		

		
			





 
 I should test them as soon as i got them but instead put them away and forgot about them now i a can't returned it.


----------



## gibosi

i luvmusic 2 said:


> Will i was in luck that i found a guy that have a tube tester but on the other hand my tubes were tested shorted and low.
> 
> 
> 
> ...


 
  
 I run all new tubes in my amp for around an hour. This alone is a pretty good test. But even so, it would be nice to have a tube tester, especially for double triodes. It would be great to be able to test both sides to see if one might be significantly lower than the other.


----------



## i luvmusic 2

It sure be nice to have tube tester.Weird that one side of the tube is shorted and the other is not but it tested low.Thanks!


----------



## MMMan

i luvmusic 2 said:


> It sure be nice to have tube tester.Weird that one side of the tube is shorted and the other is not but it tested low.Thanks!




What does testing low do to the sound of a tube?


----------



## i luvmusic 2

I'am not sure because i don't know much about electronics but if i plug-in that tube tested low i need to turn the volume knob past my volume preference.


----------



## gibosi

And if only one side is low, the sound of one channel might be slightly lower than the other. The effect on the sound may well be subtle and somewhat hard to hear. But perhaps you could hear it if you were able to compare the unbalanced tube with another identical tube whose sections are more closely balanced....


----------



## i luvmusic 2

gibosi said:


> And if only one side is low, the sound of one channel might be slightly lower than the other. The effect on the sound may well be subtle and somewhat hard to hear. But perhaps you could hear it if you were able to compare the unbalanced tube with another identical tube whose sections are more closely balanced....


 
 So now i have more understanding why some of the tubes sounds unbalanced.THANK YOU!


----------



## mordy

Hi,
  
 Yesterday I was using my 6080s planning to do a comparison test with the 6832, 7963 and 5687 tubes. As you may recall my fans draw air away from the amp. Suddenly I smelled a whiff of acrid smell. Mindful of all the warnings from Gibosi and TD about running 2.5A tubes I immediately shut off my Little Dot and the rest of the system. The faint smell went away, and I switched the 6080s for 6SN7 tubes.
  
 Plugged in everything - all is OK, but I decided against taking a chance of running 6AS7/6080 tubes again in the LD MKIII. Problem is that I love the sound of these tubes - the bass is so much better. The 6SN7 tubes are OK, but they lack the heft and authority of their big brothers.
  
 So what is the next step? Should I try the 5687 tubes as power tubes? Will they have enough power to give me the bass I like? Would they be an improvement over the 6SN7s?  In addition, I would have to buy two special adapters.
  
 Or should I go the way of the other members on this forum who bought other amps? I think I know what I want: An amp that uses 6080/6AS7 tubes or similar as power tubes, and uses dual triodes as drivers. It has to be able to be used as a pre-amp as well as headphone amp. In addition, I want a protective circuit that allows me to use a DC coupled amp. (My old Sony ss amp has a protective circuit, but I can't use my Outlaw RR2150 receiver.)
  
 Little Dot makes a model that seems to have the specs I want - the MK9. However, I cannot find much of reviews or user information on this amp, and it seems that there is no English manual for it yet.  Does anybody have any information?
  
 I am open to suggestions for an upgrade, but I am not ready to build something myself. I realize that I could get whatever I want if you spend enough, but I am looking for the biggest bang for the buck (the LD MKIII certainly fits this criterion).
  
 The MK9 is around $500. It seems to me that some of the amps mentioned here like the Glenn and the Woo 2 are much more expensive, and the Crack is DIY.
  
 Any advice is appreciated.


----------



## MIKELAP

mordy said:


> Hi,
> 
> Yesterday I was using my 6080s planning to do a comparison test with the 6832, 7963 and 5687 tubes. As you may recall my fans draw air away from the amp. Suddenly I smelled a whiff of acrid smell. Mindful of all the warnings from Gibosi and TD about running 2.5A tubes I immediately shut off my Little Dot and the rest of the system. The faint smell went away, and I switched the 6080s for 6SN7 tubes.
> 
> ...


 
 Maybe get a used crack i see them for 400.00 -$500.00 assembled  but make shure you see hires pictures of it compared to the crack assembled by somebody who really knows what he's doing ,
 and also that it is a clean assembly and you compare the 2 amps and you will see soon enough if the guy followed and did everything he was supposed to by the book .Like they say a picture is worth a 1000 words .


----------



## i luvmusic 2

mordy said:


> Hi,
> 
> Yesterday I was using my 6080s planning to do a comparison test with the 6832, 7963 and 5687 tubes. As you may recall my fans draw air away from the amp. Suddenly I smelled a whiff of acrid smell. Mindful of all the warnings from Gibosi and TD about running 2.5A tubes I immediately shut off my Little Dot and the rest of the system. The faint smell went away, and I switched the 6080s for 6SN7 tubes.
> 
> ...


 
 What about Littlebear see Hypnos1's post.


----------



## i luvmusic 2

Or assembled CRACK and QUICKIE you got the crack for amp and the quickie for a Pre-amp.


----------



## gibosi

mordy said:


> Little Dot makes a model that seems to have the specs I want - the MK9. However, I cannot find much of reviews or user information on this amp, and it seems that there is no English manual for it yet.  Does anybody have any information?


 
  
 As I have also been looking at something similar, that is, two 6AS7 for power and a single double-triode driver, I have considered the MK9. However, I am slightly put-off by the fact that the amp is designed for 6N9P/6SL7 rather than the 6SN7. I have read that 6SN7's will work, but as the MK9 is not optimized for these tubes, I do not know if they would sound as good as they might in an amp designed for them. Further, I do not know about the 5687 in the MK9. As the 6N9P has .3A heaters compared to the .9A for the 5687, it is not clear if the LD9 can run tubes drawing 3X the heater current. Another limitation I see is no provision for 12V tubes. But of course, there is no reason why an external heater PS couldn't be slapped on as we are now doing. But for only $500, even with these reservations, it just might be good enough..... or not.....


----------



## i luvmusic 2

Would it be nice if the S.E.X. can be modified to run 6AS7's or 6SN7's this will be my next amp in the near future.


----------



## MMMan

gibosi said:


> As I have also been looking at something similar, that is, two 6AS7 for power and a single double-triode driver, I have considered the MK9. However, I am slightly put-off by the fact that the amp is designed for 6N9P/6SL7 rather than the 6SN7. I have read that 6SN7's will work, but as the MK9 is not optimized for these tubes, I do not know if they would sound as good as they might in an amp designed for them. Further, I do not know about the 5687 in the MK9. As the 6N9P has .3A heaters compared to the .9A for the 5687, it is not clear if the LD9 can run tubes drawing 3X the heater current. Another limitation I see is no provision for 12V tubes. But of course, there is no reason why an external heater PS couldn't be slapped on as we are now doing. But for only $500, even with these reservations, it just might be good enough..... or not.....




I've looked too.... And the Mk 9 has the best price for the feature set required. However, right now I am happy with nice 6SN7s in the Mk IV.

BTW, the LD Mk VI owners threads seem to like the 6SN7 as a driver, despite the lower gain.


----------



## TrollDragon

Hey mordy,

Upon smelling an acrid smell, I would guess that you have some resistors on the board that are partially cooked or have been overheated enough to turn the paint on then black. You really should pop the amp apart and investigate, as those resistors won't last.


----------



## mordy

Hi TD,
  
 I'm afraid that if I open up the amp and take it apart I'll won't be able to put it together correctly again. Meanwhile, everything is working as it should.
  
 There is a post somewhere that a person who had a problem with a MKIII contacted David Zhe Zhe and was advised to send it to a repair place in California. Apparently, the parts and labor on the Little Dot amps are covered, except for the shipping.


----------



## hypnos1

Right guys, here goes...
  
 First, the BAD news...I'm a first class idiot (which some may have gathered by now lol!). 
	

	
	
		
		

		
		
	


	



  
 Second, the GOOD news...my LD hasn't been nuked after all!!! (I am fairly sure).
  
 Before carting her off to the repair man, I decided to do just one last complete check. This time, it occurred to me to use the meter and confirm there was no signal at the headphone connection inside the amp...lo and behold, THERE WAS! 
	

	
	
		
		

		
		
	


	




 So I unplug at the 'phone, test the plug and...yes, you've got it...NO READING...doh...! I pull it apart and.. 
	

	
	
		
		

		
		
	


	




..both (thin) silver wires (+) detached...
  
 The one thing I hadn't really considered, as I was SO careful when putting it together...sealed with resin, and generously covered in insulating tape - those tiny plugs (on the HD650) are the _devil_ to work with.
  
 So, folks, although I haven't re-soldered yet - after dinner project! - that's 99% sure to be the culprit, no?!! Will confirm later this evening.
  
 But even if all is well, from mordy's near-miss, it would appear mods ARE needed so I shall go ahead and see what my local valve/tube man suggests.
  
 Sorry to have been premature, but at least it has been a wake-up call to stop taking such a big risk and try to get it sorted...something I'm sure mordy now agrees with, lol!


----------



## hypnos1

mordy said:


> Hi,
> 
> Yesterday I was using my 6080s planning to do a comparison test with the 6832, 7963 and 5687 tubes. As you may recall my fans draw air away from the amp. Suddenly I smelled a whiff of acrid smell. Mindful of all the warnings from Gibosi and TD about running 2.5A tubes I immediately shut off my Little Dot and the rest of the system. The faint smell went away, and I switched the 6080s for 6SN7 tubes.
> 
> ...


 
  
 Hi mordy.
  
 Sorry to see your amp appears to have said "enough is enough", lol!. But all is not yet lost...perhaps some easy and not too expensive mods may just do the job (as per lemonjelly). Will know for sure soon, when my local repair man has done his stuff...and of course I'll let everyone know straight away.
  
 As you may have seen from my previous post, it does actually look like my baby may well be OK after all...silly me!!
  
 As for a replacement, I may well now not need the Little Bear, but it will certainly be a very interesting project...and who knows, with the 5687s as drivers it just _might_ be a real winner - for peanuts! 
	

	
	
		
		

		
		
	


	



  
 Good luck, whatever course you eventually take...it looks like we are both somewhat in limbo at present. And all because we can't/won't give up our wonderful 6AS7G/6080 tubes...I for one could NEVER go back...


----------



## mordy

Well, well, maybe I shouldn't be worried after all. I have a set of Chatham 6AS7 tubes on the way, with a current draw of 0.84A each. There is the possibility of the acrid whiff coming from somewhere else - my 1980s Sony 110W amp or one of the three voltage regulators on hand, or the PC 12V PS, or one of the two wall warts.....
  
 Maybe my wife's pear pie spilled over in the oven and caused the smell? Me thinks that I shouldn't be paranoid and just go for it!
  
 When my DC coupled receiver blew up I was able to smell it by sticking my nose by the amp, but this time I forgot to do this test. Tried the smell test now - no smell. Stay tuned....
  
 Hypnos 1, you made my day!


----------



## i luvmusic 2

So you guys are going back to 2  6AS7G driver tube?


----------



## mordy

_"And all because we can't/won't give up our wonderful 6AS7G/6080 tubes...I for one could NEVER go back..."_
  
 I feel exactly the same way, so in some way, manner or shape I just have to use those tubes. As mentioned, I have Chatham 6AS7 tubes on the way. I may wait for them arrive to plug into my amp just in case.....The 6AS7/6080 I only intend to use as power tubes.
  
 The 6SN7 are very nice, and a big step above the 6N6P family, but the 2.5A tubes is still much better. Meanwhile, I am using a pair of 1960's RCA 6SN7GTB as power tubes and am trying to compare the two sub miniature dual triode tubes I have (6932/7963). This got to be the most difficult comparison so far - they are that similar, but there are differences; I just have to find ways to describe the differences. In addition, I realize that they need time to warm up to sound their best (don't know if this depends on the sub miniature tube, the 6SN7 tubes or both together, but I have to wait some 20-30 min after turning them on to get the best sound).
  
 These tubes were the ultimate development of vacuum tube tube technology at the end of the tube era. Perhaps their intended use in missile warheads dictated very tight tolerances and thus the similarities.


----------



## hypnos1

mordy said:


> Well, well, maybe I shouldn't be worried after all. I have a set of Chatham 6AS7 tubes on the way, with a current draw of 0.84A each. There is the possibility of the acrid whiff coming from somewhere else - my 1980s Sony 110W amp or one of the three voltage regulators on hand, or the PC 12V PS, or one of the two wall warts.....
> 
> Maybe my wife's pear pie spilled over in the oven and caused the smell? Me thinks that I shouldn't be paranoid and just go for it!
> 
> ...


 
  
 SCOOBY-DOOBY-DOO....OH HAPPY DAY!...
  
 Yep, mordy...made my day too lol....*MY LD LIVES!! *  
  
 I cannot believe it - 'twas that darned plug all along 
	

	
	
		
		

		
		
	


	




. Normally, when a plug like that is going, there's _some_ kind of early warning...not _this_ time, obviously!
  
 Don't know how much longer I could have gone without my fix 
	

	
	
		
		

		
		
	


	




.
  
 However, m, methinks it still rather risky to continue without any mods...but tonight..TO HELL WITH IT - I'm getting my fix, lol!
  
 Cheers!




  
  
  


i luvmusic 2 said:


> So you guys are going back to 2  6AS7G driver tube?


 
  
 No ilm2...POWER tubes - for me at least, there is nothing to compare with my C3GSs as drivers for the GEC 6AS7Gs...PURE HEAVEN!!


----------



## superdux

New gear is costing me, so i want to hand over my 12AX7 adapter that MIKELAP had made and sent me. It comes with a 12AX7 to 6SL7 adapter for octals to use. There is also a brand new 1 russian octal and a tung sol 6SL7GT that goes with it if you like. I have also put some extra socket savers onto the adapter to keep the strain from plugging and unplugging off of the adapter plugs. This adapter has worked fine for me in my LD MKIII but i have come to love my C3G's more over the time. Please send me a message for further info and price.
  

  

  

  

  
 EDIT: gibosi gave me some tips on more tubes to roll with this adapter, so for the while i will be keeping it but you still can ask if you're interested.


----------



## i luvmusic 2

hypnos1 said:


> mordy said:
> 
> 
> > Well, well, maybe I shouldn't be worried after all. I have a set of Chatham 6AS7 tubes on the way, with a current draw of 0.84A each. There is the possibility of the acrid whiff coming from somewhere else - my 1980s Sony 110W amp or one of the three voltage regulators on hand, or the PC 12V PS, or one of the two wall warts.....
> ...


 
 Sorry my bad i mean POWER TUBES not DRIVER LOL,i always mixed up the two.


----------



## gibosi

mordy said:


> Well, well, maybe I shouldn't be worried after all. I have a set of Chatham 6AS7 tubes on the way, with a current draw of 0.84A each. There is the possibility of the acrid whiff coming from somewhere else - my 1980s Sony 110W amp or one of the three voltage regulators on hand, or the PC 12V PS, or one of the two wall warts.....


 
  
 Given lemonjelly's description of the "melted" resisters in his amp, I think you should still be concerned:
  
 http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/7170#post_10808730
  
 On the other hand, no one else has reported a similar failure and you may well be able to run 6AS7/6080 in your LD indefinitely. The fact that you, hypnos1 and ilm2 have yet to have a failure of any kind due to these output tubes is one more example of the value and quality inherent in LD products. These cheap little amps are simply amazing!
  
 Nonetheless, I think everyone here understands the risks very well so I will be quiet now.... (says the guy with an LD1+ which doesn't even have output tubes! lol 
  
 Cheers


----------



## mordy

Hi Gibosi et al,
  
 Thanks for the encouraging words. Something strange happened....
  
 I let my amp play with the 7963 as driver and the the two RCA 6SN7GTB as power tubes. As mentioned, I found it hard to distinguish the 7963 from the 6832. One sounded better here, the other better there, but almost the same. Suddenly I paid attention to the sound - what's going on?
  
 It sounded like I put back the 6080s in the power seat! A full, weighty, satisfying bass, a delicate, detailed shimmering treble; sweet midrange. Really don't know what happened, but suddenly the 7963 took flight and left the others behind. Maybe 48 hours wasn't enough for burn in - maybe it needs 60 hours.
  
 Here is a size comparison between the 7963 and a Coke bottle style tube:
  

  
 I am afraid to move everything around again; this is too good to change. Hope I am not imagining all this. Let's see how it sounds tomorrow.
  
 What others are saying:
  
*"The 7963, while claiming no octal forerunners (as there were no frame grid octal twin triodes), can trace its ancestry to the 6DJ8 family. In fact, with regard to audio applications, the 7963 offers performance in low level audio applications that is superior to all 6DJ8 variants, and to all other subminiature twin triodes as well."

 Absolutely SUPERB"*
  
*"It has totally blown my ears away the past few days (big style)"*
  
 Maybe some promoter will arrange a match between the C3g and the 7963 to see who is the reigning champion....


----------



## hypnos1

gibosi said:


> Given lemonjelly's description of the "melted" resisters in his amp, I think you should still be concerned:
> 
> http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/7170#post_10808730
> 
> ...


 
  
 I know I _should_ be concerned/careful, g, BUT...after the absence (that really DOES make the heart grow fonder, lol - had almost forgotten just how wonderful the sound is now from my "Little Beauty"), I'm of a mind to postpone the (sensible) mods until lemonjelly can confirm they don't have ANY detrimental effect on the sound WHATSOEVER...if there's the slightest hint they do, I shall continue to play Russian roulette until (possibly!) the worst happens 
	

	
	
		
		

		
			





. Very often, the best info re a problem is when something FAILS (as I have found on many occasions 
	

	
	
		
		

		
		
	


	




). Now I have to be prepared for (yet _more) _chuckles from my repair man! - he couldn't believe what we've been up to, without modifying this, and that...Yes, our LDs certainly are amazing creatures!
  
 ps...Hope you can forgive a foolish old b**ger


----------



## i luvmusic 2

I'am about to take on another amp build once i'am done with this amp my MK III is on the line up for a major surgery i will butcher this amazing amp.


----------



## i luvmusic 2

Wait BUTCHER? That doesn't sound right.


----------



## kvtaco17

Look at this handsome little thing...
  
 http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=111315291396&fromMakeTrack=true&ssPageName=VIP:watchlinken
  
 Kinda want one just for the look lol


----------



## mordy

Pretty, eh?
  
  




  




  
 U could get one as a kit for less than $300 shipped (or is it a finished amp - don't quite understand the Chinglish in the Ebay offering). Tubes are not that expensive. Look for FU-32 or 832 tubes.


----------



## kvtaco17

The engrish in the listing suggests that it's a finished amp.


----------



## TrollDragon

There is a thread here discussing that specific amp, and I guess the FU-32 tubes are absolute junk... So if your thinking of picking one up grab some 832's for when the stock tubes let go in a week or are DOA...


----------



## Rossliew

kvtaco17 said:


> Look at this handsome little thing...
> 
> http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=111315291396&fromMakeTrack=true&ssPageName=VIP:watchlinken
> 
> Kinda want one just for the look lol


 
 I have this exact amp at home. Not bad sounding and works great with headphones as well, both low n high impedance. I think it is a kit that you would need to assemble yourself or did i read that correctly...


----------



## kvtaco17

Ha good to know... I'm not buying another amp... See my signature... Lol

I will be selling a few though!


----------



## mordy

Hi,
  
 Back to the serious business of evaluating tubes. The Sylvania 7963 is changing, but only for the better. The bass is getting stronger and better - hard to believe. This is a superb tube. Not much eye appeal with it's spindly wires and tiny size, but the sound is absolutely amazing. Great soundstage, excellent imaging, super presentation and clarity in the lows, mids and highs - WOW!
  
 Highly recommended!


----------



## MMMan

1578s....




Pretty, and sound amazing!! Very nice trebles, with persistence on cymbals plus great defined bass, great energy (attack) on snares and other high energy transients plus beautiful mids (brass, woodwinds and voice). Highly recommended from first hand enjoyment.

Ps - make sure yours have holes in the plates.... Not just metal base!


----------



## mordy

Are these the ones?
  
 http://www.ebay.com/itm/ORIGINAL-1578-TUBES-NOT-6N8S-HOLE-PLATE-2-NEW-NOS-/161385223327?pt=Vintage_Electronics_R2&hash=item25934f149f


----------



## hypnos1

Well guys, although I'm _really_ loving my MKIV SE once again, like many others I'm always looking for something that might just topple it - but without spending a fortune lol!
  
 I thought I might have found a good contender in the Feliks-Audio Espressivo-E (reviewed in a thread on this forum). However, although VERY nicely made, it only has mediocre Sovtek tubes in situ. and therefore not up to OUR standards!
  
 Anyway, I thought I would just point out to them they would find a much bigger market (especially in the US and Canada) if they used 6SN7s as drivers and 6AS7G/6080s as powers...and they seemed quite interested. They were a little concerned about tube cost, but I pointed out that most enthusiasts already have these tubes, or are prepared to seek out good used old stock, if not NOS.
  
 If this sounds interesting to anyone here, why not email them with your thoughts...could be a worthwhile option, perhaps?...feliks-audio.pl
  
 BTW...the Little Bear P8 arrived today and looks very well made. But with only one driver! So I can't even have a proper preliminary listen 
	

	
	
		
		

		
		
	


	




. But with just one channel in my ears, the volume knob is having to go fairly high. Perhaps ilm2's slight disappointment with the Crack could well be down to ONE 6AS7/6080 not really being enough to give the necessary power/dynamics for best performance?
 Of course, it's much too early for me to get a proper idea yet! 
	

	
	
		
		

		
		
	


	




.
  
 ps. Forgot the pics of the Feliks-Audio, lol...


----------



## i luvmusic 2

My MK III will never see a $100+ tube not even $30/Tube............
	

	
	
		
		

		
		
	


	




 
 The most i spend for my CHATHAM 6AS7G's are $20/tube and some that i got from auctions it works out to $10.50/tube i've got seven tubes from that auction.
 Not even the CRACK or the S.E.X. will see that amount for a tube.


----------



## i luvmusic 2

hypnos1 said:


> Well guys, although I'm _really_ loving my MKIV SE once again, like many others I'm always looking for something that might just topple it - but without spending a fortune lol!
> 
> I thought I might have found a good contender in the Feliks-Audio Espressivo-E (reviewed in a thread on this forum). However, although VERY nicely made, it only has mediocre Sovtek tubes in situ. and therefore not up to OUR standards!
> 
> ...


 
  Actually the 6SN7's on the CRACK is not that bad but compared to 12AU7's(which is i prefer)sound like the 12AU7's have more gain.Or maybe it depends on the tube because all my tubes are used none of them are NOS but you know what i wan't some 6DN7 for the S.E.X. i will asked my vendor if he can sell me a NOS 6SN7's. I would like to try a newer 6SN7 for the CRACK.


----------



## i luvmusic 2

40 what?
	

	
	
		
		

		
			





 One NOS RCA 6SN7 GTB for $45 no thanks.So much for a NOS tubes LOL.


----------



## mordy

Thoughts about the Little Dot MK9? It uses 6080/6AS7 and 6SL7 (could be substituted for 6SN7)


----------



## i luvmusic 2

If we run MK III with Two 6080/6AS7G and one 6SL7/6SN7(which i do once in awhile)isn't it functioning like the MK9?
 For me i don't need MK9 i already own it(MK III using tubes for MK9)


----------



## MMMan

mordy said:


> Are these the ones?
> 
> http://www.ebay.com/itm/ORIGINAL-1578-TUBES-NOT-6N8S-HOLE-PLATE-2-NEW-NOS-/161385223327?pt=Vintage_Electronics_R2&hash=item25934f149f



 
Yes, the exact ones. From the Ukraine. I have bought quite a few good tubes of that seller.


----------



## MMMan

My C3g adapters arrived today:



Wow, they sound beautiful with the 1578s! Too early for a full review, but I have no doubt this combination could be an 'end game' for many. Full rich sound, with great bass and not much compromise in other areas.


----------



## MMMan

My three 'new gear' CDs are Miles Davis KoB, Sinead O'Conner Am I not ur grl, and Eric Clapton Undrugged. All slightly different sounds and each beautiful in its own rights. I know each better than any other recordings. Right now, with the tubes mentioned above, KoB sounds sublime (again!).

BTW, if you like classic female old school big band jazz/blues vocals, look up the Sinead album.


----------



## MMMan

i luvmusic 2 said:


> My MK III will never see a $100+ tube not even $30/Tube............
> The most i spend for my CHATHAM 6AS7G's are $20/tube and some that i got from auctions it works out to $10.50/tube i've got seven tubes from that auction.
> Not even the CRACK or the S.E.X. will see that amount for a tube.




I have bought a LOT of tubes super cheap. I spent a long time poaching auctions on great 6SN7s. If you read some of the 6SN7 threads, you can learn to recognise re-branded great tubes and pick them off for < $15. 

eBay never sleeps, but it does sometimes 'look the other way'. I have poached great tubes listed as 6SNGT (missing 7) that don't show up in the straight forward search and I have found amazing tubes in grab bag lots from estate sales. Getting a bargain is great fun. I have a pair of Ken Rad VT 231 s on the way for less than $10 each!! But there are some tubes that are more difficult to get a bargain on. It is very unlikely you will ever get real 1578s on the cheap.... Or Tung Sol BGRPs.

Happy hunting


----------



## MMMan

For example:




The first pic is from a lot of 5 6SN7s I bought for $35. These two tubes are both black glass NUs, that sell for $70 to $90 a pair. All were reported as 'test good'. A great deal.

The second two are a Ken Rad VT231 and a grey glass Sylvania VT231 I picked up from an estate auction for $15. A great deal... And fun finding a match for each on the cheap!

It is important for everyone to know that very good deals are out there. Perhaps not all NOS tubes, but still testing 'good'....


----------



## hypnos1

mmman said:


> My C3g adapters arrived today:
> 
> 
> 
> Wow, they sound beautiful with the 1578s! Too early for a full review, but I have no doubt this combination could be an 'end game' for many. Full rich sound, with great bass and not much compromise in other areas.


 
  
 Hi MMMan.
  
 I am _so_ glad you like those C3Gs...just you wait 'til they have 30+ hours on them - you'll be blown away! Would have loved to see how those 1578s compare to my GEC 6AS7Gs, but at those prices I shall have to pass lol!! Shall just continue to take the risk, unless I chicken out and do (or have done for me) the suggested mods to make the 6AS7Gs safer to use 
	

	
	
		
		

		
		
	


	




   
	

	
	
		
		

		
		
	


	




.
  
 Enjoy!!


----------



## mordy

Hi,
  
 After listening to the Sylvania 7963 sub miniature tube I have come to the conclusion that it needs some 70 hours of burn in to bring out the full potential. At that stage the bass became much more articulated and stronger. Tried it with my pair of Chatham 6080 tubes (nothing untoward happened) but somehow there was too much bass and it sounded boomy. The synergy wasn't there.
  
 With the pair of RCA 6SN7GTB (top heater wire) the synergy is there, and I can revel in the clarity and detail of the entire musical spectrum + great musicality and sound stage. There is a multilayered presentation of the music, and on obscure 20s recordings i can follow and pick out individual instruments with much greater ease than before. It is hard to tear yourself away from the listening - it is so beautiful with superb sound in all ranges.
  
 In addition, these tubes are easy to drive for the MKIII and no external power supplies are needed. Don't know what the "cryo treatment" my fans add, but the amp is literally cold to touch, and the power tubes are barely warm.
  
 Happy tube rolling! (BTW, the entire tube complement cost me less than $20)


----------



## hypnos1

mordy said:


> Hi,
> 
> After listening to the Sylvania 7963 sub miniature tube I have come to the conclusion that it needs some 70 hours of burn in to bring out the full potential. At that stage the bass became much more articulated and stronger. Tried it with my pair of Chatham 6080 tubes (nothing untoward happened) but somehow there was too much bass and it sounded boomy. The synergy wasn't there.
> 
> ...


 
  
 WELL DONE, mordy! Sounds like you're getting the same kind of magic that I am - but for much cheaper lol! Can't be bad 
	

	
	
		
		

		
		
	


	




. And no need for external "gubbins"...even better!!
  
 That heavy, boomy bass is why I stuck with the 6AS7Gs....the Chathams and especially the (expensive!) GECs 
	

	
	
		
		

		
		
	


	




.
  
 Out of interest, what differences do you find between your 7963s and the 5687s?


----------



## gibosi

mmman said:


> .......But there are some tubes that are more difficult to get a bargain on. It is very unlikely you will ever get real 1578s on the cheap.... Or Tung Sol BGRPs.


 
  
 If you are patient, even good deals on TS BGRPs can be found. Many are rebranded and some sellers don't know what they have. Recently, I saw one branded RCA in a RCA box. The seller thought it was an RCA and had it listed for $15, "Buy It Now". I tried, but must have just missed it, as it was already gone....     lol.
  
 I currently have three, two of which are branded Emerson, and I also have a 12SN7. And I didn't pay all that much for any of them.
  
 At least in my experience, patience will always be rewarded.


----------



## gibosi

hypnos1 said:


> Out of interest, what differences do you find between your 7963s and the 5687s?


 
  
 Mordy, 
  
 I too am curious how the Sylvania 7963 and the Sylvania 5687WA compare in your rig. In my LD+, they are very, very close.


----------



## mordy

Hi hypnos 1,
  
 Today the fabled 6AS7 Chatham tubes arrived with a price tag just slightly over my self imposed limit. I assume that the tubes were made in Dec 1958. First impression is excellent: unusually coherent and wide sound stage and great detail. The bass has more slam and the treble more sizzle than the RCA 6SN7GTB tubes but nothing of the boominess I heard with the 6080s in combination with 7963.
  


 Here is an explanation of this experimental setup: In the center are the two Chatham tubes. To the right is a 15A voltage regulator powering the heaters. In the background left is the humble 7963 tube mounted on a breadboard with wires going to the Vector adapters in the drivers seats. On top right and left are two computer fans that draw away air from the amp.
 The voltage regulator is using a very sophisticated mounting plate of premium scrap wood from a floor molding that is attached with two rubber bands to the transformer housing. In order to aid in cooling two Chinese chopsticks are inserted behind this mounting plate. The metal rod between the chopsticks belongs to a temperature probe to monitor the transformer housing temperature. The blue and yellow strips on the left are two plastic tie-ties to hold the smaller fan in place.
  
 The amp is mounted on three 1980s aluminum cone footers (not seen in picture) to lower vibrational effects and aid in cooling. The chassis temperature is monitored by the human touch by inserting the hand under the the amp to feel the temperature. (At the present slightly warm.) I also use olfaction to monitor the health of the amp.
  
 For some reason it appears to me that these tubes run cooler than the 6080s, although they are said to draw 0.84A each.
  
 Re the question of comparing the 7963 to the 5687 I need to do a head to head comparison and then figure out which combination sounds best (Chatham vs Chatham or 6AS7 vs 6080) to pronounce a winner or a draw. But first I need to convince myself that the 5687 sounds the same on a 6V or 12V diet.
  
 Below is a close-up of the coke bottle style Chatham 6AS7G tube as well as another coke bottle style tube. The latter has a liquid but dark and fizzy presentation, but more about that at another time.....
  


 PS. After this picture was taken the real Coke bottle took revenge and pushed the imitation coke bottle off the desk smashing it into oblivion. At least it wasn't a GEC tube, and I still have a pair left, but now I know how it feels......


----------



## superdux

A few pages ago, i offered my 12ax7 adapter but no one seems interested, so i was going to roll some 12ax7 next month and wanted to ask you if there is something i have to look out for to not harm my beloved LDMKIII?
  
 EDIT: Mikelap just told me to look up the list on following page

 http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/4875#post_10229116


----------



## gibosi

mordy said:


> For some reason it appears to me that these tubes run cooler than the 6080s, although they are said to draw 0.84A each.


 
  
 Electrially, the 6080 and 6AS7 are virtually identical including 2.5A heaters.Where did you get this 0.84A number?


----------



## gibosi

superdux said:


> A few pages ago, i offered my 12ax7 adapter but no one seems interested, so i was going to roll some 12ax7 next month and wanted to ask you if there is something i have to look out for to not harm my beloved LDMKIII?
> 
> EDIT: Mikelap just told me to look up the list on following page
> 
> http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/4875#post_10229116


 
  
 Yes, a number of us have  run 12AX7-type tubes in our LDs with absolutely no problems. Also, I ran a number of 5751, which I thought were pretty good.
  
 You might find this to be an interesting read:
  
  http://www.audioasylum.com/scripts/d.pl?audio/faq/joes-tubes.html#12AX7
  
 Edit: Also, if you are using an external heater PS, the E80CC is a great tube. There are the more common Tunsgram and Heerlen-made versions, and the more rare, and better to my ears, early Eindhoven and Hamburg versions. However, the heaters draw .6A when run in the 6.3V setting so again, an external heater PS is necessary. 
  
 And another very fine tube that has the same pinout as a 12AX7 is the Brimar 13D3, but the heaters draw .65A at 6.3V, so again an external heater PS is necessary.


----------



## MMMan

mmman said:


> For example:
> 
> ....snip.....
> 
> ...




This is the match for the top left tube:



Total cost for the pair: $12. eBay was looking the other way... Very happy


----------



## superdux

gibosi said:


> Yes, a number of us have  run 12AX7-type tubes in our LDs with absolutely no problems. Also, I ran a number of 5751, which I thought were pretty good.
> 
> You might find this to be an interesting read:
> 
> http://www.audioasylum.com/scripts/d.pl?audio/faq/joes-tubes.html#12AX7


 
 hi gibosi,

 thx for your advice, i read the site about 12ax7 and maybe want to try some 5751 out.Do they share same pin layout as with 12ax7?
 As for the list they should all run at 350mA.Guess i'll have to look for a bargain tube on the bay.Mikelaps adapter doesn't work with external power supply, it combines the 2 front tube outlets of my amp, so i'll have to beware of not too high mA rates.


----------



## gibosi

All the 12A-7's: 12AU7, 12AT7 and 12AX7 have the same pinout, and as the 5751 is just a ruggedized 12AX7, with slightly less gain, it too has the same pinout.
  
 And now I remember, you are using Mikelap's adapter so no external l heater PS. But fortunately, all these tubes are perfectly safe to use in your rig.
  
 Cheers


----------



## gibosi

And on the chance you don't have one of these.... you can purchase an adapter which will allow you to roll 6DJ8/ECC88 tubes in a 12AX7 socket:
  
 http://www.ebay.com/itm/1pc-gold-plated-6cg7-6fq7-TO-ECC82-12AU7-tube-adapter-6-3V-heat-/201083377532?


----------



## superdux

Hi gibosi,
  
 i think a 6V tube won't work in mikes adapter as he told me only to use 12V tubes yesterday, so i'm not sure about that.
  
 anyway we have something called sperrmuell here in germany where people put out their trash onto the street for pickup and i found an old german radio and picked out the tubes so if any of you like to take a look:
  

  

  

  

  

  

  
 it says "Lorenz ECH81","Lorenz EL84","Lorenz EADC 80" and "Lorenz EF89" on them.


----------



## gibosi

superdux said:


> i think a 6V tube won't work in mikes adapter as he told me only to use 12V tubes yesterday, so i'm not sure about that.


 
  
 I assure you that with an adapter, 6DJ8/EC88 tubes will work fine. The heaters in the LD are 6.3V, not 12.6V. The only reason 12AX7 tubes will work at all in the LD is that it is possible to wire these tubes to run on 6.3V. This is what Mike's adapter does. It is wired to run a 12AX7 on 6.3V. And the adapter I linked to above allows you to use a 6DJ8 in a 12AX7 socket that has been wired to operate at 6.3V.


----------



## hypnos1

mmman said:


> This is the match for the top left tube:
> 
> 
> 
> Total cost for the pair: $12. eBay was looking the other way... Very happy


 
  
  


mmman said:


> For example:
> 
> 
> 
> ...


 
  
 Sorry...think I got the postings the wrong way round!
  
 Anyway, MMMan, your examples (and gibosi's...not to mention mordy's results after patient searches) have shown that 6SN7s _can_ be found for reasonable money...which brings me to an update on my suggestion to the Feliks-Audio Espressivo-E people, in Poland, to consider changing those mediocre tubes for 6SN7 drivers and 6AS7G/6080 powers...AND THEY'RE GOING TO BUILD A PROTOTYPE!! ...WOWEE!...If they can manage to keep the price below the LD MK9 and LaFigaro 339, that should be a giant killer to say the least!! 
	

	
	
		
		

		
		
	


	




.
  
 Will keep y'all posted...
  


gibosi said:


> Mordy,
> 
> I too am curious how the Sylvania 7963 and the Sylvania 5687WA compare in your rig. In my LD+, they are very, very close.


 
  
 Well, gibosi, I can see why you love the 5687...I have only just finished cobbling together (much against my usual principles, lol! 
	

	
	
		
		

		
		
	


	




) your (and mordy's) "flying" monstrosities...my excuse being I needed to make sure they would be OK in my new Little Bear!
  
 Given that the amp hasn't many hours on it, and the tubes/masses of wires even less...plus only my HD598s to test (until I patch into my 650s), to say I'm VERY impressed is understating things at the very least 
	

	
	
		
		

		
		
	


	




. With one of my GEC 6AS7Gs in the hot seat, I am fairly confident already that this cheapie chappie will almost be a match for the LD III & IV with modded upgrades. And for less than $200 (free shipping), this is quite ridiculous!!
  
 I am sure the 5687s are a major help here...although I was very UNDERwhelmed by their appearance (especially compared to the C3Gs!), I can tell already that they are all you say they are...EXCELLENT. The full potential is a ways off yet...but I am getting really excited at the prospect of what may come, after proper burn-in/proper (silver-wired!) adapters/650s in tow 
	

	
	
		
		

		
		
	


	




.
  
 And then will come the shoot-out with the fully-loaded LD...can't wait lol!


----------



## bbmiller

gibosi said:


> The only reason 12AX7 tubes will work at all in the LD is that it is possible to wire these tubes to run on 6.3V. This is what Mike's adapter does. It is wired to run a 12AX7 on 6.3V. And the adapter I linked to above allows you to use a 6DJ8 in a 12AX7 socket that has been wired to operate at 6.3V.


 
 Anybody have any details on this type of wiring to wire a 12 V filament tube to run on 6 V is this possible with many 12 V tubes?


----------



## MIKELAP

gibosi said:


> I assure you that with an adapter, 6DJ8/EC88 tubes will work fine. The heaters in the LD are 6.3V, not 12.6V. The only reason 12AX7 tubes will work at all in the LD is that it is possible to wire these tubes to run on 6.3V. This is what Mike's adapter does. It is wired to run a 12AX7 on 6.3V. And the adapter I linked to above allows you to use a 6DJ8 in a 12AX7 socket that has been wired to operate at 6.3V.


 
 Its been awhile i didnt remember that but when i looked  at the octal to 9 pin adapter that goes in copper adapter it is marked 6.3 v on it so my bad and thanks gibosi for pointing that out .


----------



## MIKELAP

Was just checking this out on page 267 and this is what gibosi told me back then i tought it sounded familiar .post 4004
  
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                
  
 And 6 volts is correct. Fortunately, the 12AX7 can be used with either 12 volt or 6 volt heaters. The Little Dot heater supply voltage is 6 volts, so we wire the 9-pin socket (by using pin 9) to run the 12AX7 on 6 volts. And since the 6SL7 is also a 6 volt tube, it works flawlessly.


----------



## superdux

Thx @gibosi and @MIKELAP, i'll guess then i'll do some more tube rolling in the future. There are so many tubes to roll with MIKELAPS adapter and i hope i'll find a special one.


----------



## gibosi

bbmiller said:


> Anybody have any details on this type of wiring to wire a 12 V filament tube to run on 6 V is this possible with many 12 V tubes?


 
  
 It's easy. In 12V mode, you would connect the heater supply directly to pins 4 and 5. But of course, this requires that you have a 12V heaters. In an amp with 6V heaters, first, you connect the heater supply to pins 4 and 9 (heater center tap). And then you need to tie pins 4 and 5 together. Fortunately, the triode elements, cathode, grid and anode, are identical for 6DJ8 and 12A-7 tubes, so the only change necessary to switch between the two of them is the heater wiring. This will work for 12AU7, 12AT7 and 12AX7, as well as E80CC and 13D3 (these last two need an external heater PS), and there might be others that I am overlooking....
  
 5687, 7044 and E182CC/7119 are similar, in that they can also be wired for 12V or 6V, but the wiring is slightly different. In these tubes, pin 8 is the heater center tap. (However, these need more current than the LD can provide, so an external heater PS is required.) To run these in 6V mode, tie pins 4 and 5 together, and connect the heater supply to pins 4 and 8.
  
 In the 6DJ8, pin 9 is attached to the shield. In the 12A-7, pin 9 is attached to the heater center tap. Otherwise, the triode sections, cathode, grid and anode, are wired identically. So to switch between 6DJ8 and 12AX7, the only change necessary is for the heaters. For the 5687 tubes, the triode-section wiring is not quite the same as a 6DJ8. so it is also necessary to rewire pins 6 and 9 if switching between 6DJ8 and 5687.
  
 Below, a pic of my 9-pin socket wired to run 5687 tubes in 6V mode. The fat wires are the heater supply, and you can see that I have bridged pins 4 and 5.
  

  
  
  
  
 Have fun!  
  
 Edit: typo


----------



## mordy

Hi hypnos 1,
  
_"update on my suggestion to the Feliks-Audio Espressivo-E people, in Poland, to consider changing those mediocre tubes for 6SN7 drivers and 6AS7G/6080 powers...AND THEY'RE GOING TO BUILD A PROTOTYPE!! ...WOWEE!...If they can manage to keep the price below the LD MK9 and LaFigaro 339, that should be a giant killer to say the least!! 
	

	
	
		
		

		
		
	


	




._
  
_Will keep y'all posted..._"
  
 When you are communicating with the Feliks people, please ask them to design and incorporate a protective circuit so that a direct coupled  (DC) amp can be used. I assume that the amp will not only be a headphone amp, but could be used as a preamp as well. I would be happy to evaluate the amp as well....


----------



## bbmiller

gibosi said:


> bbmiller said:
> 
> 
> > Anybody have any details on this type of wiring to wire a 12 V filament tube to run on 6 V is this possible with many 12 V tubes?
> ...


 
 Thanks for that pic and all!


----------



## MIKELAP

mordy said:


> Hi hypnos 1,
> 
> _"update on my suggestion to the Feliks-Audio Espressivo-E people, in Poland, to consider changing those mediocre tubes for 6SN7 drivers and 6AS7G/6080 powers...AND THEY'RE GOING TO BUILD A PROTOTYPE!! ...WOWEE!...If they can manage to keep the price below the LD MK9 and LaFigaro 339, that should be a giant killer to say the least!!
> 
> ...


 
 The MK9 has such circuit and can be used with dc amps if its as good and cheaper that would be interesting but cheaper than chinease amps ?


----------



## hypnos1

mordy said:


> Hi hypnos 1,
> 
> _"update on my suggestion to the Feliks-Audio Espressivo-E people, in Poland, to consider changing those mediocre tubes for 6SN7 drivers and 6AS7G/6080 powers...AND THEY'RE GOING TO BUILD A PROTOTYPE!! ...WOWEE!...If they can manage to keep the price below the LD MK9 and LaFigaro 339, that should be a giant killer to say the least!!
> 
> ...


 
  
 Hi m.
  
 Have sent them an email and am now awaiting a reply. Don't yet know what facility they might have for demo-ing...I suspect the project will take quite some time lol! (Will keep you informed).
  


mikelap said:


> The MK9 has such circuit and can be used with dc amps if its as good and cheaper that would be interesting but cheaper than chinease amps ?


 
  
 Yes, MIKELAP...it will be a minor (no, MAJOR!) miracle if they can come up with something about the same price point as the MK9 (or less ? 
	

	
	
		
		

		
		
	


	




)...We live in hope..
	

	
	
		
		

		
		
	


	




...


----------



## mordy

Hi Gibosi et al,
  
 I finally got around to compare the 5687 tube to the 7963 sub mini tube.  Both tubes are made by Sylvania. Power tubes are the Chatham 6AS7G, and the 5687 is running on 12V.
  
 In this setup the 5687 sounds great, but a little laid back. The bass is very strong and fat. Excellent, coherent and wide sound stage and great treble. Very musical and very good detail.
  
 The 7963 is more forward sounding with better instrument separation, more lively and quick, and more engaging. Instruments stand out in relief and the bass, mid range and treble are just about perfect. However, as I am writing this the 5687 is settling in and the sound and the presentation of the 5687 is getting much closer to the 7963. The 5687 is more polite and the 7963 more forward sounding.
  
 Both these tubes are the best I have encountered in the search for audio perfection using the Little Dot MKIII, and they sound very close to each other. To me the winner is the Sylvania sub miniature 7963. This unknown mighty midget wunderkind tube is currently available on Ebay from a single seller with a price of under $7 when bought as a lot of five. My hunch is that the seller has many lots, but he only puts out one at a time. If you like to try it, please don't drive up the price and let the first bidder get it, and wait for the next offer. (In the past sellers got around $20-25 each for the tubes).
  
 http://www.ebay.com/itm/5-x-7963-NOS-NIB-Sylvania-Subminiature-Frame-Grid-Twin-Triodes-/261575626159?pt=Vintage_Electronics_R2&hash=item3ce71f4daf
  
 This 7963  tube has no visual appeal but everything else you could want. Should you want to try the 5687 you could find them singly for under $10 with a little patience. I tried Tung Sol, GE and Sylvania, and like the Sylvania the best followed by the Tung Sol.
  
 The 7963 is the end game for me (until something else better comes along!). Oh, I forgot, the 7963 first blossoms in full after some 65-70 hours of burn in!
  
  
 Happy tube rolling!


----------



## hypnos1

mordy said:


> Hi Gibosi et al,
> 
> I finally got around to compare the 5687 tube to the 7963 sub mini tube.  Both tubes are made by Sylvania. Power tubes are the Chatham 6AS7G, and the 5687 is running on 12V.
> 
> ...


 
  
 Aah, BUT...you haven't tried the C3GS have you,m?!...Get digging deep into those pockets lol!! 
	

	
	
		
		

		
		
	


	




...


----------



## gibosi

mordy said:


> In this setup the 5687 sounds great, but a little laid back. The bass is very strong and fat. Excellent, coherent and wide sound stage and great treble. Very musical and very good detail.
> 
> The 7963 is more forward sounding with better instrument separation, more lively and quick, and more engaging. Instruments stand out in relief and the bass, mid range and treble are just about perfect. However, as I am writing this the 5687 is settling in and the sound and the presentation of the 5687 is getting much closer to the 7963. The 5687 is more polite and the 7963 more forward sounding.
> 
> ...


 
  
 I have both these tubes, plus the 1940's Sylvania 6SN7W, and my experience is very similar to yours. Of these three, the 7963 is the brightest, while the 5687 and 6SN7W are a bit more laid back. These three Sylvania double triodes are among the very best tubes I have, including a pair of C3g. However, over the last four months or so of living with the 7963, I have begun to notice that on some tracks it is just too bright with my HD700's, sometimes to the point of unpleasantness. On the other hand, this tube makes my HE300's, which are considerably darker, sound the best they ever have.
  
 Based on my experience, I suspect that the 5687 or 6SN7W might be better in brighter systems, whereas, the 7963 might be better in darker systems.  As cheap as the 5687 and 7963 are, I strongly recommend you get one of each to see which works best for you.
  
 Cheers


----------



## mordy

Hi hypnos 1 and Gibosi,
  
 Guess I have to go on the German Ebay site and see if I can find a pair of C3g tubes for a song; then I have to buy the custom adapters for another $60 etc. At this point my self imposed budget limits precludes trying this tube....
  
 Re the brightness of the 7963: I don't find it overly bright. In my system I have old fashioned tone controls and can tone down the tube a little. With the 7963 I find the best setting turning down the treble a little and turning up the bass a little. I find that the 7963 affords more detail in the lower bass and mid range than the 5687, and that it is more forward.
  
 A lot of things are system dependent - as they say: YMMV.


----------



## MMMan

Hi Mordy,

You just might enjoy the c3 g as drivers. They do enhance the bass potential of the power tubes and from everything I've read, you like a nice warm sound.

I don't think I'll keep them as my primary drivers tho. I really like my 6J3P-E tubes as drivers. Perhaps a bit more detail at the high end, with more attack and more defined bass. I'm still going to enjoy switching between these two drivers as new power tubes come in.... But it is not an obvious or easy choice between the two.


----------



## MMMan

Last night, the match for my Ken Rad VT-231 arrived and I switched out my 1578s. 

Very nice sound, but a bit too Bassy (not kick drum bass, more bass guitar or double bass Bassy), which is fine for many. These tubes are sometimes called the king of bass. I like more solid and defined bass. I rolled in a different driver combo ( switched from c3g to 6J3P-E) which are a bit tighter on the low end.... See how they go for the next few days.


----------



## hypnos1

mmman said:


> Hi Mordy,
> 
> You just might enjoy the c3 g as drivers. They do enhance the bass potential of the power tubes and from everything I've read, you like a nice warm sound.
> 
> I don't think I'll keep them as my primary drivers tho. I really like my 6J3P-E tubes as drivers. Perhaps a bit more detail at the high end, with more attack and more defined bass. I'm still going to enjoy switching between these two drivers as new power tubes come in.... But it is not an obvious or easy choice between the two.


 
  
 Hi MMMan...you surprise me. Have you given the C3gs more than 30 hours yet? I found they kept improving up to 50 hrs, in fact! 
	

	
	
		
		

		
		
	


	




.


----------



## MMMan

hypnos1 said:


> Hi MMMan...you surprise me. Have you given the C3gs more than 30 hours yet? I found they kept improving up to 50 hrs, in fact!  .




I will give them more time. I wanted to listen to some new power tubes with drivers that I am used to. They will come back into the rotation soon.... So far, they sound as described above. After three days of listening to them, that is close of music 30 time....


----------



## hypnos1

mordy said:


> Hi hypnos 1,
> 
> _"update on my suggestion to the Feliks-Audio Espressivo-E people, in Poland, to consider changing those mediocre tubes for 6SN7 drivers and 6AS7G/6080 powers...AND THEY'RE GOING TO BUILD A PROTOTYPE!! ...WOWEE!...If they can manage to keep the price below the LD MK9 and LaFigaro 339, that should be a giant killer to say the least!!
> 
> ...


 
  
 Hi mordy.
  
 Good news...they have agreed to incorporate said circuit 
	

	
	
		
		

		
		
	


	




. They are obviously interested in suggestions that are feasible, without pushing up costs  _too _much. Lorspeaker over at "For 6AS7G tube rollers here" suggested balanced amp facility...a fully balanced circuit I am sure would add too much to the cost, but I shall ask if at least a balanced output as well as SE might just be possible...They have certainly got their work cut out, lol!!


----------



## i luvmusic 2

hypnos1 said:


> mordy said:
> 
> 
> > Hi hypnos 1,
> ...


 
 These is where the S.E.X. come to play SE,BALANCED and it can drive speakers (2W) from the speaker output if they can do these in a reasonable cost i'am in.


----------



## mordy

Hi hypnos 1,
  
 Thanks for forwarding my suggestion. Any inkling about price and time frame?


----------



## MMMan

Their current amp, which uses 6N6P power tubes, sells for £220 on eBay.... Which is already more than a Mk 9.

Given everything we have seen that our LD amps can do, I would find it hard to believe something else could offer the same quality and durability for less, or even 2 or 3 x more expensive!!


----------



## i luvmusic 2

Meaning what i'am asking will be more expensive than all my current equipment.......


----------



## kvtaco17

i luvmusic 2 said:


> Meaning what i'am asking will be more expensive than all my current equipment.......


 

 I'm really convinced that the next logical step for all of us is a Glenn amp lol
  
 My OTL is pretty awesome for all my cans with the right tubes ( a good rectifier GZ32 on the cheap, some 5998's for HD800's, 6336's for low impedance cans, and 6080's for a do everything tube... all driven with your favorite 6SN7)


----------



## kvtaco17

And fyi Ill be listing my o2, ODAC, and Lyr soon if any of you guys want first dibs on scooping any of it.


----------



## i luvmusic 2

kvtaco17 said:


> i luvmusic 2 said:
> 
> 
> > Meaning what i'am asking will be more expensive than all my current equipment.......
> ...


 
  Way out of my budget,My next purchased will be a HP since i just have the HD 650,CRACK and now the S.E.X. on it's way,This is where i'am going to stop buying HP and AMP.Similar to what i did back when we were rolling tubes i'v'e been tempted  to get the C3g and some other expensive Tubes and i just stop at CHATHAM 6AS7G's and 6SN7's.If i only have the money i will get the GLENN AMP.


----------



## MIKELAP

kvtaco17 said:


> I'm really convinced that the next logical step for all of us is a Glenn amp lol
> 
> My OTL is pretty awesome for all my cans with the right tubes ( a good rectifier GZ32 on the cheap, some 5998's for HD800's, 6336's for low impedance cans, and 6080's for a do everything tube... all driven with your favorite 6SN7


 
 Is this amp around $700.00


----------



## gibosi

Or with the appropriate adapters, your favorite 6DJ8, 5687, or what have you. Any double tride you can run in your LD will work fine in a Glenn OTL.


----------



## mordy

What do you think about burning in a tube without being plugged into the amp - only connected to an external PS for the heaters? Could that work?


----------



## gibosi

mikelap said:


> Is this amp around $700.00


 
  
 When I checked last April, the base price was $650. And if you wanted an additional switch to accommodate 6.3, 12.6 and 25 volt tubes, it was $50 more.


----------



## gibosi

mordy said:


> What do you think about burning in a tube without being plugged into the amp - only connected to an external PS for the heaters? Could that work?


 
  
 I do not know... If only the heaters are energized, there is no current flowing through the tube, cathode to plate. Is this a problem? I do not know....
  
 But.... when we first started to roll 6DJ8's we were using two tubes but connecting only one triode in each tube. However, even though we were using only one triode in each tube. we were heating both cathodes, which left one triode "hanging". And I seem to remember that Audiofanboy expressed concern that heating a triode with no signal could lead to "cathode poisoning". So it might not be a good idea to heat the cathodes while leaving the triodes "hanging"...


----------



## hypnos1

mmman said:


> Their current amp, which uses 6N6P power tubes, sells for £220 on eBay.... Which is already more than a Mk 9.
> 
> Given everything we have seen that our LD amps can do, I would find it hard to believe something else could offer the same quality and durability for less, or even 2 or 3 x more expensive!!


 
  
 Hi MMMan.
  
 I just looked on ebay, and the MK9 is going for $469 (£284, @ $1.65 = £1), plus $59 (£36) delivery.
  
 If the feliks-audio guys can manage to pitch at not _too_ much more than this price point...perhaps by having extras like a balanced output as an optional upgrade, for example (which I shall put to them), then it surely would be a real contender...


----------



## hypnos1

mordy said:


> Hi hypnos 1,
> 
> Thanks for forwarding my suggestion. Any inkling about price and time frame?


 
  
 Hi mordy...no problem...
  
 Lukasz mentioned within a month...
	

	
	
		
		

		
			





. I suppose at this early stage it will be difficult to come up with a close approximation of price, but I'm going to ask if they can possibly pitch at not too much more than the MK9. So long as it can be a good bit below the Crack S.E.X.; LF339 and the Glenn, then it should be a real contender...


----------



## lemonjelly

Hi, I was reading about transformers and because I kinda created some worry over the 6AS7 tubes, I thought I'd put some minds at rest....  We're actually running the transformer under it's rating (I think) with the 6AS7 tubes.  I wasn't sure before how it worked if you weren't using all of the secondaries - as we aren't using the heater windings - but from what I've read, they sum.
  
 So the ratings for the different windings are: 175v@0.1A, 6.8v@2.5A and 2*3.3v@1A.
  
 So in total the amp has available... 175*0.1 + 6.8*2.5 + 2(3.3*1) = 41.1va.  If you're not using any of the heater windings, and to keep in spec, this means you can use up to... 41.1/175 = 235mA throughout the amp.  So with the 6AS7s in a stock amp probably using around 170mA, there shouldn't be any problem as far as the transformer.  You're still probably taking a risk with the resistors, but they won't be massively out of their rating (the 5W power resistors are just @ or slightly over their rating with 6AS7s).
  
 Anyway enjoy the music as always !


----------



## i luvmusic 2

hypnos1 said:


> mordy said:
> 
> 
> > Hi hypnos 1,
> ...


 
 Or they can send us the parts/schematic and lets DIY the AMP that would keep the cost down even more.
	

	
	
		
		

		
		
	


	




 That's what Bottlehead do...........


----------



## mordy

Hi lemonjelly.
  
 I'm not quite sure I understand your calculations, but empirically I feel that it is safe to use the Little Dot MKIII with 6AS7/6080 power tubes using external heaters. Today I have been running the Chatham 6AS7 tubes  over 10 hours straight with my computer fans moving away the air. At this point, being in an air conditioned room at 72F, the temperature at the bottom of the tube at the decorative ring is 89F, the chassis is 79F, and the transformer housing is 83F. The amp feels slightly warm to the touch.
  
 As mentioned before, when burning in an EF91 tube in the past the amp got significantly much hotter, and those tubes are on the recommended list for this amp.
  
 I can not assess the suitability and performance of the internal resistors, but so far so good..........
  
 Thanks for your looking into this.


----------



## hypnos1

hypnos1 said:


> Hi mordy...no problem...
> 
> Lukasz mentioned within a month...
> 
> ...


 
  
 Have had word from them, and they are seriously trying to work towards a figure *BELOW $500, *with balanced output being considered as a possible optional extra, depending on demand (which is understandable). This would certainly be no mean feat, and I can only hope they manage to pull it off 
	

	
	
		
		

		
		
	


	




.
  
 I have finally decided to start a new thread on this (with encouragement from Lorspeaker) - "*Feliks-Audio...6SN7 + 6AS7G/6080 prototype"* for anyone interested in this project. Not really fair to keep on about it in this thread!...So ALLcomers welcome - I shall be updating as soon as I hear any more news from the Feliks guys.
  
 The wait continues...could this be like expecting a child lol?! 
	

	
	
		
		

		
		
	


	



  


lemonjelly said:


> Hi, I was reading about transformers and because I kinda created some worry over the 6AS7 tubes, I thought I'd put some minds at rest....  We're actually running the transformer under it's rating (I think) with the 6AS7 tubes.  I wasn't sure before how it worked if you weren't using all of the secondaries - as we aren't using the heater windings - but from what I've read, they sum.
> 
> So the ratings for the different windings are: 175v@0.1A, 6.8v@2.5A and 2*3.3v@1A.
> 
> ...


 
  
 Hi lemonjelly.
  
 Are we really OK? As gibosi has mentioned, aren't they separate windings for anodes and heaters? I remember TrollDragon voicing concerns over the transformer if higher rated resistors are used...
  
 Cheers!


----------



## lemonjelly

hypnos1 said:


> Hi lemonjelly.
> 
> Are we really OK? As gibosi has mentioned, aren't they separate windings for anodes and heaters? I remember TrollDragon voicing concerns over the transformer if higher rated resistors are used...
> 
> Cheers!


 
 Hmm I'm learning this stuff as I go, so I needed to check this a bit more carefully.  The VA rating above is correct for the entire transformer, so the transformer can handle that amount of power and the resultant heat, but obviously the question is whether the winding itself can manage.  Apparently if you don't use the heater windings, then it does mean you can use more current in the HT winding, as the transformer is cooler due to not using those windings.  It's pretty hard to work out exactly how much leeway this gives you however - it's definitely not as simple as I assumed above - but it seems like really about 50% extra or so would be realistic (so 150mA HT).  You're OK so long as no part of the transformer gets so hot that you can't keep your hand on it from the sounds of it (a transformer dies when it gets so hot the laminations between windings melt and the transformer shorts).
  
 + I know that I had the transformer at over 180mA and it was hot, I'd say probably fairly close to as hot as I'd want it, but it still worked fine.  And that's with my wooden/acrylic chassis whereas a stock amp would have the metal casing as a heatsink.  So yep it's still a risk, but I think it's much less of a risk than I thought before... as in the transformer is pretty close to being in spec (maybe slightly over but nothing like as over spec as I thought it was before) and the resistors probably also are over/@ spec, but they're likely to last for a decent amount of time (but this is where I'd expect failures really).


----------



## gibosi

Is anyone getting bored? lol I have a suggestion for a new tube to try:
  
 PCC85 / 9AQ8
  
 This is a double triode with the same pinout as the ECC88, but 9 volt heaters! So you will need an adjustable external heater PS. From what little I can find on Google, it seems to be pretty good and I figure it is worth a look.
  
 There are a few eBay sellers offering these for ridiculous prices, but there also are plenty of bargains to be had. I have a 1960's era Telefunken NOS/NIB coming my way for $10. And American brands can often be had for less than $5.


----------



## lemonjelly

gibosi said:


> Is anyone getting bored? lol I have a suggestion for a new tube to try:
> 
> PCC85 / 9AQ8
> 
> ...


 
 Agreed ... tldr it's not that much of a risk to run 6AS7s... but still a little bit of a risk.  And I don't have a horse in this race any more as I bought a cheap 165v HT transformer, and so am now running the 6080s I have at over 90mA, with a 6SN7 for about 100ma per transformer (the stock transformer for 1 channel, the 165v HT 1 the other).
  
 There are so many good tubes to try... it's a bit scary really.  I've basically finished modding (I'll put in some DN2540s/IXY45s as CCS for plate load/cathode bias but that's a simple mod), so will be trying some of the tubes you guys have recommended soon.  The miniatures look interesting... and of course the c3gs at some point (but that's a bit more expensive), and I'm currently thinking about ordering some 6E5Ps, which are supposed to be good, but look like they pull a lot of current.  I don't think anyone has tried them yet?  If I try them I'll let you all know how it goes + if they're usable in a stock amp of course (be good to contribute something to this thread that I've lurked for a long time).
  
 And currently burning in the final mod on my amp, which are some 100uF obligatto film caps in place of the stock 220uF/330uF output electrolytics - it's enough capacitance for my 300 ohm HD650s but probably wouldn't be enough with the bass rolloff on lower impedance cans.


----------



## gibosi

lemonjelly said:


> ..............and I'm currently thinking about ordering some 6E5Ps, which are supposed to be good, but look like they pull a lot of current.  I don't think anyone has tried them yet?  If I try them I'll let you all know how it goes + if they're usable in a stock amp of course (be good to contribute something to this thread that I've lurked for a long time).


 
  
 The 6E5P does indeed look interesting. However, building two clean and neat adapters to triode-strap these 9-pin tetrodes and convert them to a 7-pin B7G base may well be a challenge for some of us. (And you can count me as one of those!) I would be inclined to use two 9-pin breadboard sockets to accomplish the strapping and then route the triode elements into the LD through the existing 7-pin vectors, ugly and easy. lol 
  
 And if it turns out that these work well in the LD, and sound good, I am sure we could ask one of the Chinese eBay sellers to make converters for us, as they did for the C3g.
  
 A couple more Russian tubes that might be worth trying are the 6N1P and 6N5P. These are double triodes with the same pin-out as a 6DJ8. However, they have 0.6A heaters, so an external PS is necessary.


----------



## mordy

Hi,
  
 Found an interesting review comparing the MKIII to the MKVI. This was written in 2008 so I assume it refers to the first version of the LD MKIII. The relevance to me is that the the MK9 amp basically is half of a MKVI. Here is what the reviewer says:
  
 "So, the question is: considering the price difference between the two amps, is the MK6 worth the $500 difference (excluding shipping difference)? After listening to both amps for extended periods of time, I can say that for $200, the MK3 is truly a very good amp. Although its sound is beat by the MK6 in almost all categories (as expected), it takes a much more expensive balanced setup to reaffirm just how good the MK3 is. The overall sound signature is almost identical to that of the MK6. It’s just that the latter sounded like two of the former combined. If you do not want to spend too much on headphones audio, I’d suggest sticking with the LD MK3. However, if you are an experienced audiophile and wish to try out how balanced audio sounds, the Little Dot MK6 would be a very good choice. If Little Dot could sort out the component(s) making the buzz and entirely eliminate the noise, the MK6 would be one of the best bargains in the audio market today. For me, let’s just say after going balanced, I do not ever want to go back."
  
 It seems to me that with the mods we have found, using 6AS7/6080 power tubes and the great driver tubes discovered, the sound of the MKIII should be approaching the sound of the MK9 (MKVI). I do not understand how using a balanced set up with speakers will improve the sound.
  
 If you want to see the entire review the link is here:
  
 http://www.compudio.ca/2008/10/exclusive-review-little-dot-mk6.html


----------



## lemonjelly

gibosi said:


> The 6E5P does indeed look interesting. However, building two clean and neat adapters to triode-strap these 9-pin tetrodes and convert them to a 7-pin B7G base may well be a challenge for some of us. (And you can count me as one of those!) I would be inclined to use two 9-pin breadboard sockets to accomplish the strapping and then route the triode elements into the LD through the existing 7-pin vectors, ugly and easy. lol
> 
> And if it turns out that these work well in the LD, and sound good, I am sure we could ask one of the Chinese eBay sellers to make converters for us, as they did for the C3g.
> 
> A couple more Russian tubes that might be worth trying are the 6N1P and 6N5P. These are double triodes with the same pin-out as a 6DJ8. However, they have 0.6A heaters, so an external PS is necessary.


 
 Yep I was thinking of something similar (to be able to try them).  I've got a 6080 tube that had stopped working, and so I smashed it and reused the base - soldering in wires to the wires going to the 8 pins (including the heaters).  As I replaced the 7pins with a single octal socket, I can then use it as an adaptor for any tubes I want to try.  I've just tried it with EF95s to see if it worked OK, and might eventually take readings with EF91/EF92/EF95 tubes just to compare what bias they run at compared to the 6SN7 I've got in currently (it'll be interesting to see what all of the readings etc are especially for the EF91s/92s).
  
 Interesting review mordy... I'd agree I think with the changes to the tubes we've made that we probably are approaching similar quality to the mkVI.  But I have noticed that the sound with 2 transformers (so basically a little like a balanced amp in that there is reduced crosstalk as the channels aren't directly connected) is improved.  How much a properly balanced setup would improve on that I'm not sure - cos balanced is really meant when using long cable runs to reduce interference.


----------



## mordy

Hi lemonjelly.
  
 I have a broken octal tube as well. How do I disassemble the octal bottom from the rest of the tube?


----------



## lemonjelly

mordy said:


> Hi lemonjelly.
> 
> I have a broken octal tube as well. How do I disassemble the octal bottom from the rest of the tube?


 
 Um.... I just smashed it.  The 6080 I had has a metal base anyway (Thomson) so that stayed together... and then I just cut off the main body of the tube from the rest... and could solder wires to the wires coming off the pins.  Really it's just cos I had a broken tube and I wanted the octal base (cos I've replaced the 7 pins with the octal in my amp).  It's interesting to see all the makeup of the tube if you do that though, still think the workmanship etc that goes into tubes is amazing really.


----------



## yomomma1

Hijack!
  
 I have buzzing coming from my left channel (mk4 SE) it starts after a short time or if the desktop is even gently knocked. HELP!


----------



## lemonjelly

yomomma1 said:


> Hijack!
> 
> I have buzzing coming from my left channel (mk4 SE) it starts after a short time or if the desktop is even gently knocked. HELP!


 
 Hi, the easiest thing to check first are the tubes.  You can swap the tubes from one side to another, and wiggle them a bit while you have the buzz to see if it is a dodgy connection with the tubes.  If it's that then cleaning the pins/changing the tubes will probably fix it.  After that it'll probably be a loose connection.  To find where it is you could see if you can move physically/flick/whatever the: volume control; headphone cable socket; and RCAs at the back of the amp, and just see where the problem seems to be (my bet going off the MKIII build would be the volume pot or RCAs).  It's easier if you can narrow down where the problem is, but it's probably a dodgy connection in one of those if it isn't the tubes.  
  
 Then it'll probably mean a visit to a repair shop, returning to LD, or opening the amp yourself if you're handy with a soldering iron.  If opening the amp, leave music playing and turn the amp off (so leave the source connected) and wait for the sound to go as quiet as possible.  Then the voltage in the amp should be dissipated mostly (but will dissipate more if you can leave it overnight), but still avoid touching any of the capacitors unless you either short the terminals first or use a resistor across the terminals to get rid of any of the voltage (you shouldn't need to be dealing with any of the capacitors though).  Then you might be able to see where the loose connection is easily, or just resolder any of the connections that look dull on whichever component it is that seems to be causing the problem. 
  
 I wouldn't be too worried though, the difficulty will be finding where the fault is rather than the fixing of the problem.  + ofc let us know how it goes !


----------



## yomomma1

Cheers pal. I have changed tubes over and ran as a pre-amp so not tubes or HP socket. Will check other options, I started to take it apart but chickened out and put it back together, I'm not confident with that so will poss take it in somewhere?
  
 Thanks again.


----------



## lemonjelly

yomomma1 said:


> Cheers pal. I have changed tubes over and ran as a pre-amp so not tubes or HP socket. Will check other options, I started to take it apart but chickened out and put it back together, I'm not confident with that so will poss take it in somewhere?
> 
> Thanks again.


 
 It's probably a good plan .  The problem with taking the amp apart - as you probably found - is that it's pretty shoehorned in there.  I should've said that if you do that then you have to be really careful cos you could break connections just because it's such a hassle to pull it out enough to work on it.  But kinda forgot as I've not worked in that chassis in so long !  If you do take it somewhere it should be a simple job for them... I would think the volume potentiometer or input RCAs are the most likely places where the dodgy connection is as before.
  
 Edit: saw your post about the preamp thing as well so I'll just tag a reply on here.  The problem when using the LD as a preamp is with DC coupled amps, so long as your amp isn't DC coupled (which I think is fairly rare, but more common in audiophile stuff) then there aren't any problems.  It's cos DC coupled amps don't have a blocking capacitor to stop DC (less capacitors in the signal path and all that) and there's a chance the LD will pass some DC voltage across, that will then get amplified by the amp and possibly blow the speakers (some DC coupled amps will have a protection built in to prevent it even then though).  LD and from the looks any manufacturer of DC coupled amps just flat out say it's not a good idea for them to be used together.


----------



## MIKELAP

lemonjelly said:


> It's probably a good plan .  The problem with taking the amp apart - as you probably found - is that it's pretty shoehorned in there.  I should've said that if you do that then you have to be really careful cos you could break connections just because it's such a hassle to pull it out enough to work on it.  But kinda forgot as I've not worked in that chassis in so long !  If you do take it somewhere it should be a simple job for them... I would think the volume potentiometer or input RCAs are the most likely places where the dodgy connection is as before.
> 
> Edit: saw your post about the preamp thing as well so I'll just tag a reply on here.  The problem when using the LD as a preamp is with DC coupled amps, so long as your amp isn't DC coupled (which I think is fairly rare, but more common in audiophile stuff) then there aren't any problems.  It's cos DC coupled amps don't have a blocking capacitor to stop DC (less capacitors in the signal path and all that) and there's a chance the LD will pass some DC voltage across, that will then get amplified by the amp and possibly blow the speakers (some DC coupled amps will have a protection built in to prevent it even then though).  LD and from the looks any manufacturer of DC coupled amps just flat out say it's not a good idea for them to be used together.


 
 Thats exactly what i was told when i wanted to use my LD mk3 with my 70's Pioneer. I was told tough that the LD MK9 can be used with DC coupled amps .


----------



## mordy

Hi yomommo1,
  
 Another source of hum not be overlooked could come from electric interference, especially portable phones and appliances. If you have a portable phone or base station near your amp, see what happens if you move it away or turn it off. I found that I can reduce hum by moving and repositioning the various breadboards and adapter wires that I am using with my LD MKIII.
  
 Hi lemonjelly,
  
 I have a DC coupled receiver that I cannot use with the MKIII.  Do you know of any kind of circuit or outboard unit that can be added to block the high DC voltage?


----------



## yomomma1

Hmm....well I ran it through a lovely Denon amp )yes they do exist) and more recently through my Marantz 610 but it hummed (which is defo not a phone related issue, don;t have a phone near it and it occurs if I even tap on the desk) I turned the amp off when it buzzed and the 610 almost blew! Popped and went off, couldn;t switch it on for a while, thought I'd killed it!!!


----------



## lemonjelly

mikelap said:


> Thats exactly what i was told when i wanted to use my LD mk3 with my 70's Pioneer. I was told tough that the LD MK9 can be used with DC coupled amps .


 


mordy said:


> Hi lemonjelly,
> 
> I have a DC coupled receiver that I cannot use with the MKIII.  Do you know of any kind of circuit or outboard unit that can be added to block the high DC voltage?


 
 Hi yep I think they included a DC protection circuit in the later amps.  If someone wanted I would think you could do this yourself + add it to the chain.  Probably there would be 2 ways of doing it, either after the DC coupled power amp with something like this (http://www.ebay.co.uk/itm/2X-Stereo-Speaker-protection-DIY-kit-Dual-relay-with-startup-delay-DC-protection-/221390943192?pt=US_Home_Audio_Amplifiers_Preamps&hash=item338bedb3d8) or after the LD with something like this (http://www.ebay.co.uk/itm/MINI-UPC1237-Headphone-Protector-Protection-For-Headphone-Amplifier-AMP-Project-/150784726223?pt=UK_Sound_Vision_Other&hash=item231b7854cf).  They just kick in once the DC voltage gets above a certain level, so you're not using the circuit all of the time, but it just gives you insurance that your speakers will be protected.
  
 I'd guess really that you'd be best using the speaker protection version as I wouldn't be sure what voltage would be safe to be amplified by the power amp (and would depend on the power amps volume/gain I would think).  The other problem is potentially that the DC offset, even below a dangerous level might still be enough to degrade the sound (it isn't a good thing even in moderation).  
  
 Edit: just read a bit more about this (there's a good audiok thread if you google for dc offset blown speaker), so it seems you'll always have a bit of offset with a DC coupled amp anyway, and you can check to see how much that is with a multimeter.  I suppose with the speaker protection board above, you would protect your speakers from any bad tube problems, and you could check what the DC offset is with/without the LD connected to see if the DC offset changes much, and use your ears ofc to see what you prefer.


----------



## hypnos1

Hi guys.
  
 Although at the moment I'm all caught up with the Feliks-Audio project, I still like to see what's going on here! (By the way, the new prototype will have the protection circuit for DC direct coupled amp use...).
  
 And even though this is an old topic, I have just noticed that the famous GLENN has a unit at $2,500, and he's using the C3g as drivers...so must be a pretty good tube, eh?! 
	

	
	
		
		

		
			





..


----------



## mordy

Hi LJ,
  
 Thanks for your reply. I am a little bit confused, because I don't know what I need, either something to protect my DC coupled receiver, my speakers, or both.
  
 I have an Outlaw RR2150 100W ss receiver. I used it with the LD MKIII as a pre-amp successfully for several years. One day one channel blew in the receiver. I had it repaired, but did not realize that I had blown one of my speakers. When connecting the speaker, the receiver blew again.
  
 The speaker was replaced under warranty, the receiver repaired again (they did not charge me the second time), but I am afraid to use it with the LD amp.
  
 Is seems to me that I need something between the LD and the receiver. At this time time the LD is connected to the receiver with RCA interconnects to an external (equalizer) loop.
  
 All the various modules I looked at are inexpensive enough and usually DIY. One manufacturer will sell you a finished unit for another $4.00.
 Could you look at these offerings and tell me what I need? How do I connect it?
  
 http://www.ebay.com/sch/i.html?_odkw=1237+protection&_from=R40&_osacat=0&_from=R40&_trksid=p2045573.m570.l1313.TR0.TRC0.H0.X.TRS5&_nkw=Stereo+Speaker+protection+kit+Dual+relay&_sacat=0
  
 http://www.ebay.com/sch/i.html?_from=R40&_trksid=p2050601.m570.l1313.TR0.TRC0.H0.X1237+protection.TRS0&_nkw=1237+protection&_sacat=0
  
 Or do I need something else?
  
 Presently I am using a 1980's Sony 110W ss amp. This amp has a built in protective relay. It's quite nice, but the RR2150 has many more features and I would like to use it without worry.


----------



## lemonjelly

mordy said:


> Hi LJ,
> 
> Thanks for your reply. I am a little bit confused, because I don't know what I need, either something to protect my DC coupled receiver, my speakers, or both.


 
 Hi, cos I'm not using my LD as a preamp I haven't really looked at any of this before... but it's interesting so I'll have a read on stuff over the weekend and see if we can work it out (hopefully other people will also chime in).  I wasn't sure if an amplifier would become damaged or not by DC being passed, but it seems like that can be the case, so if we can put in a circuit to avoid too much DC being passed from the LD that would probably be the best plan.
  
 The relays you linked to will protect your speakers (they kick in when DC goes over 1v for a lot of those circuits) but whether that means the amp will still blow or not I'm not sure.  It seems like the options are basically first add a capacitor in series to block any DC going to the receiver (in between the ouput RCAs from the LD and the input RCAs to the receiver).  Or add a relay which kicks in when the DC goes over a particular value (which will depend on the gain of the receiver).  If you add the capacitor in then potentially you're making the sound worse - this is why the DC coupled amp doesn't have any input capacitors in the first place.  But this shouldn't make much difference depending on the value (determining the frequencies passed) and quality of the capacitor (film etc would be best).  The relay would still allow some DC through which could make the sound worse just because speakers don't like DC.
  
 After just looking briefly maybe adding an input capacitor in between the amps would work best... but I'll have a more thorough read over the weekend.
  
 Edit: and an easy way of seeing the offset from the LD is to use a multimeter and connect to the +ve/-ve coming out of the amp - easy if you have senns as you can just put the probes on the spade connectors of each channel.  Or not cos actually you need a load to get accurate readings .... so have headphones plugged in and take the measurements from the RCAs.


----------



## i luvmusic 2

I can see fireworks.......


----------



## mordy

Hi,
  
 Over on the Feliks Audio thread people are extolling the virtues of the 6N13S Svetlana Tubes with a winged "C". Did anybody compare them to the Chatham 6AS7G tubes?
  
 If I decide to get a pair, which years and production should I look for?
  
 After a lot of trial and error I must admit that I am partial to US made tubes, but I am open for suggestions.....


----------



## i luvmusic 2

Is these the one?Less bass and treble compared to RCA 6AS7G's but i like this 1960's Svetlana Winged "C" 6H13C for vocals/mids.
 BTW these was my first 6AS7G tube and paid $6/tube + shipping.


----------



## genclaymore

I bought some mullard CV4010 off ebay and so far I liking them,I don't know how to explain how it sounds but the first thing I notice was the mids and then the bass impact, I liked the 6J1P-EB's but the details was a bit too much. Seems like the CV4010 sound imaging is different too, I not sure how to say it. Go it from a usa seller and it was a tad cheaper then the seller who was outside of the usa, that had the CV4010. I fear this vacuum tube swapping is gonna be like my op-amp rolling past, with  dozen of boxes of tubes in the closet, falling all over the place.


----------



## gibosi

genclaymore said:


> .............I fear this vacuum tube swapping is gonna be like my op-amp rolling past, with  dozen of boxes of tubes in the closet, falling all over the place.


 
 Only dozens of boxes? Probably more like hundreds of boxes! lol


----------



## mordy

Hi,
  
 Just got this tube with a new type of tube designation. What kind of tube is it? (The tube was made in Dec 1971)
  

 Hint: It is not that difficult to figure out, but why?


----------



## mordy

Hi genclaymore,
  
 Why don't you rely on the tube rollers on this forum that tried dozens and hundreds of tubes - one of the best (and least expensive) tubes that can be used without any modifications is the Ei 6HM5. [Plug and Play]
  
 http://www.ebay.com/itm/6HM5-EC900-Lot-of-four-4-tubes-EI-Yugoslavia-NOS-free-shipping-/251611916081?pt=Vintage_Electronics_R2&hash=item3a953d2731
  
 In the past it was possible to buy them for $5 each incl shipping. Nothing lost in making a low ball offer......


----------



## gibosi

mordy said:


> Hi,
> 
> Just got this tube with a new type of tube designation. What kind of tube is it? (The tube was made in Dec 1971)
> 
> ...


 
  
 That is bizarre! EFHGWA = 5687WA, but indeed, why? lol  And from the internals, the anodes, the getter support plate, the reinforcement rods and the copper grid posts, I would say it is a Sylvania.


----------



## mordy

Hi G,
  
 You scored 100 + bonus points for figuring out that it is a Sylvania! My guess is that the tube people got frustrated when the tube era was ending and made strange designations. I actually have a tube, Sylvania as well, with a date code XYZ!


----------



## MIKELAP

genclaymore said:


> I bought some mullard CV4010 off ebay and so far I liking them,I don't know how to explain how it sounds but the first thing I notice was the mids and then the bass impact, I liked the 6J1P-EB's but the details was a bit too much. Seems like the CV4010 sound imaging is different too, I not sure how to say it. Go it from a usa seller and it was a tad cheaper then the seller who was outside of the usa, that had the CV4010. I fear this vacuum tube swapping is gonna be like my op-amp rolling past, with  dozen of boxes of tubes in the closet, falling all over the place.


 
 What you need is this  case or a couple of them lol it goes fast and if you start with the 6AS7 and 6080 tubes type youll run out of room fast since that picture was taken  i filled up another case with the bigger tubes


----------



## mordy

Found a less elegant way of storing my tubes, but definitively less expensive. I use old shoe boxes where the contents are marked with a sticker. These are easy to stack, but here they are laid out to show the concept. This is maybe a third of the boxes I have.

  
 Each box is marked with the contents:
  

  
 Each individual box tube box is marked with what's inside. This is handy since oftentimes the markings wear off, even when handled gently.
  

  
 Many of my tubes lack boxes. The little paper with designation, dates and notes is attached to the tube with a rubber band. The paper comes from an adding machine roll. When using the tube the paper is taken off.
  

  
 With so many tubes it is hard to remember what is what. I am sure that there are many other ways to organize the tubes, but this simple system works for me.
  
 Nic, how do you find what you are looking for among your 7000 tubes? (I only have around 400)


----------



## i luvmusic 2

For those of you who are welling to sell some 6080's,12AU7's and 6SN7's let me know.Thanks!


----------



## genclaymore

mordy said:


> Hi genclaymore,
> 
> Why don't you rely on the tube rollers on this forum that tried dozens and hundreds of tubes - one of the best (and least expensive) tubes that can be used without any modifications is the Ei 6HM5. [Plug and Play]
> 
> ...


 
 The main reason why I don't buy outside of the usa mostly is the duty charge. I don't look forward to being charge a but load of money just because i trying to shave off some money and get something cheaper. Also it easier and faster to get it when i buying within the usa. If something happens I can easily return it for a refund. Like if something comes broken.  Where I would have to spend some money just to ship it back, Unless tube sellers outside of the usa ship the replacements without shipping the damaged during shipping ones back. 
  
 Before I got the 6J1P-EB Tube's I was trying to make up my mind on the M8100/CV4010's. I didn't get the CV4010 then because they was outside of the USA while the Russian tube's wasn't. I also have a 2.0 Little Dot MK 2 that already been modded from the factory, Unless you mean different kind of modified. When I got the CV4010 and it was shipped, I saw a lot of 5 for a bit more then what I paid, that wasn't there at first but that didn't bother me, because next time I might get a lot.
  
 I did listen to couple of people in this thread that mentioned 6J1P-EB(6ZH1P-EV) which I bought. I did enjoy the 6J1P-EB but I wanted to give the CV4010 a try too as I read about it and it seem interesting. I wasn't aware of the Ei 6HM5's in the first place, I tried to find info on their sound signature and i haven't found any thing yet.


----------



## MIKELAP

genclaymore said:


> The main reason why I don't buy outside of the usa mostly is the duty charge. I don't look forward to being charge a but load of money just because i trying to shave off some money and get something cheaper. Also it easier and faster to get it when i buying within the usa. If something happens I can easily return it for a refund. Like if something comes broken.  Where I would have to spend some money just to ship it back, Unless tube sellers outside of the usa ship the replacements without shipping the damaged during shipping ones back.
> 
> Before I got the 6J1P-EB Tube's I was trying to make up my mind on the M8100/CV4010's. I didn't get the CV4010 then because they was outside of the USA while the Russian tube's wasn't. I also have a 2.0 Little Dot MK 2 that already been modded from the factory, Unless you mean different kind of modified. When I got the CV4010 and it was shipped, I saw a lot of 5 for a bit more then what I paid, that wasn't there at first but that didn't bother me, because next time I might get a lot.
> 
> I did listen to couple of people in this thread that mentioned 6J1P-EB(6ZH1P-EV) which I bought. I did enjoy the 6J1P-EB but I wanted to give the CV4010 a try too as I read about it and it seem interesting. I wasn't aware of the Ei 6HM5's in the first place, I tried to find info on their sound signature and i haven't found any thing yet.


 
 I buy tubes in the U.S and abroad and so far i paid duty once hope my luck continues .Have you tried the SEARH THIS THREAD function


----------



## genclaymore

mikelap said:


> I buy tubes in the U.S and abroad and so far i paid duty once hope my luck continues .Have you tried the SEARH THIS THREAD function


 

 I not gonna worry about the 6HM5 any way, I sure they might be good like people are mention but I need exact detail of how it sound and i only see a couple of people mention that it neutral, but neutral to one person is different to another and that's not enough for me to go on. I gonna just enjoy my CV4010 and I don't plan on buying any more tube's for a very long time.  I only got the CV4010 because I had a feeling that I was missing out on something by not getting it over the 6J1P-EBs.


----------



## i luvmusic 2

If you really want a tube that is better than any plug and play tubes for LD you can DIY or buy an adapter for 6SN7  tubes or you can used some miniature tubes i can't remember which one because these tube are tiny i misplaced mine
	

	
	
		
		

		
			





.Just search these thread for miniature tube and for the adapters.


----------



## mordy

Hi genclaymore,
  
 Have gotten dozens of tubes from outside the US and never had to pay any customs. If you buy on Ebay your purchase is guaranteed. If a tube is broken in shipment (happens here and there) the seller usually makes good on it. Only have one case where a pair of tubes from Hungary never arrived. Contacted the seller who sent out a second pair registered mail.
  
 If you have a problem, Ebay/PayPal will reimburse you - no worries at all. Won a voltage regulator on an auction for less than $4 when the going rate was around $12 the cheapest. The Chinese seller contacted me and said he was new to Ebay and did not want to sell it to me and would refund the money. I called Ebay and asked what the policy is if you win an auction and the seller doesn't want to honor the price. They told me that he must honor the price, and if he doesn't he will not be allowed to do business on Ebay.
  
 Told the seller this information, and he sent the item + left me good feedback. The feedback feature is a very powerful tool, and nobody wants even a hint of negative feedback.
  
 Re modifications I mean using dual triodes with adapters and external voltage sources.
  
 Look up post #6935 and #7173 for some observations on the Ei 6HM5 tubes.
  
 Under the headline for each page on the blog you find:
  
Unread Posts Subscribed Search This Thread Preferences
  
 Click on Search this thread. Then it says: Search for posts in this thread. Type in 6HM5 and click the circle for Relevance. Then scroll down. When you find something you like to read, click on View Full Post.
  
 Good luck!


----------



## mordy

> What does "JTL" mean?


 It is a military procurement acronym for Joint Theater Logistics.  Similar to JAN, Joint Army Navy.
  
 So now u know what JTL means on a vacuum tube....


----------



## Oskari

... or JTL = JAN-CTL meaning Tung-Sol.


----------



## mordy

Yep, went through my mind that I've only seen JTL on Tung Sol tubes.


----------



## gibosi

A couple of 6N5P's, manufactured in the Novosibirsk factory, with triple micas and flat, black plates arrived in the mail today, one manufactured in 1963 and the other in 1968. There are some internal construction differences between these tubes, the most notable being the getter, a flat disc in 1963 and the more familiar flying saucer in the 1968. This is quite interesting as I have never seen a disk getter on a Russian tube before. Anyway, I just popped the 1963 in and I am pleased to be able to report that it lights up and doesn't sound bad at all.
  

  
 I also received four 1974 6N1P's, made in the Voskhod factory, and these were pretty cheap, $4 each, including shipping from Ukraine. According to the datasheet on the vendor's site, each of these tubes has about 1 mg of gold, specifically gold grids, similar to the 6N1P-E and -EV. While my cell-phone pic is poor, the grid does have a slightly yellow-gold tinge, so perhaps they do.
  

  
 Both of these tubes have the same pin-out as a 6DJ8, but 0.6A heaters, so an external heater PS is required.


----------



## mordy

Hi G,
  
 It is interesting to note that Russian vendors always point out the gold grid if present. However, the gold grid was first introduced by GE in the 50's and used in some of their 5 Star tubes, but they never made it a marketing ploy. Don't know if the gold grid adds to the audio qualities of a tube, but it seems that the microscopic frame grid construction does. The windings in a frame grid are said to be so thin that they cannot be seen with the naked eye.
  
 I have two different Russian tubes with gold grid and the same tube without the gold, and they do sound a little different - maybe more mellow. The 6DJ8 uses frame grid construction as well as the sub miniature dual triodes, and some of those tubes are over achievers.


----------



## mordy

Hi.
  
 Rolling along and trying different tubes and tube combinations from my tube bins. All the tubes were bought from bargain sellers on Ebay and it is hard to know if they are new or used - I guess mostly used.
  
 The power tubes are a near pair of 12/69 and 3/71 Sylvania 6080WB of the same construction. For some reason the 6080s often are referred to as "Industrial Grade." For a driver tube I first tried a Tung Sol 5687 from 6/66 with bronze plates but it did not sound so good (bright and boomy bass). Then I switched to another Tung Sol 5687 from 9/64. This tube might be NOS because it keeps improving and by now after some 15 hours it sounds very good. (The 5687 is run on 12.6V)
  
 In comparison to the Chatham 6AS7G the Sylvania 6080WB sound a little less refined but have a harder hitting bass. They also run hotter, and the amp is warm to the touch. The TS 5687 from 1964 also runs quite hot.
  
 When I powered up the Sylvanias they sounded terrible, bright and congested, but after warming up for some 20-30 minutes they got much better. So much for first impressions...
  
 Here is a day view and night view:
  

  

  
 Pretty
  
 One pretty thing deserves another - here is beautiful picture of a water lily from a trip yesterday:
  

  
  
 Still need time to crystallize out which combination I like the best, but the Sylvania x 2 + TS sounds very good, although different than the Chatham x 2 + Sylvania. Haven't figured out a way to predict the synergy between different tubes yet.


----------



## gibosi

Spoiler: 6N5P triple mica, flat black plates










  
 Have been able to spend some time with the 1960's Novosibirsk-made 6N5P's, triple micas and flat black plates, and it is my opinion that this is a surprisingly good tube. Of course, since this is a Russian tube, my first instinct was to compare it to a 1975 Reflector 6N23P which is one of my three reference tubes. (The other two are the Sylvania 6SN7W and Siemens C3g.) In terms of tonality and 3-D stage, I find it to be very close. Next, I rolled in a 1957 Tung-Sol 5687WA and an early 1960's Sylvania 5687WA. Of these two, the 6N5P matches up most closely with the Sylvania. I think the Sylvania has just a bit more treble, but they are very close. Again, this tube was a real surprise, and I expect to keep it in my amp for some time.
  
 There is very little information on the web regarding the 6N5P, and further, there is a Chinese version of the 6AS7 often listed under the same number, which makes things a bit confusing. However, from the datasheets, it appeared to be very similar to the 6N1P, so I figured it was worth a try. In the old Lyr thread, a 6N1P with triple micas and flat black plates was mentioned by one poster as being very good, much better than the more common 6N1P which looks like a 6N23P. While lookiing for that 6N1P, I stumbled on these 6N5P's, with the same distinctive construction, and bought them on a hunch. I was also able to find a pair of the 6N1P's with the same construction and am waiting as they make their way to me from Russia. Of course, I am very curious to compare them. 
  
 Unfortunately, these are both somewhat rare, and the price has gone up recently. I paid $28 for my mismatched pair of 6N5P's and I now see matched pairs going for $50. I paid $35 for a matched pair of 6N1P's and I now see them going for $60. My suggestion is to be patient. They will very likely go back down in price eventually.


----------



## hypnos1

gibosi said:


> Spoiler: 6N5P triple mica, flat black plates
> 
> 
> 
> ...


 
  
 Hi gibosi.
  
 Re. the 6N1P, the Feliks-Audio guys' current Espressivo - E uses 2 as drivers, with 2 6N6P powers and apparently the end result was very good. So it will be interesting to see how they fare in the LD...


----------



## hypnos1

mordy said:


> Hi.
> 
> Rolling along and trying different tubes and tube combinations from my tube bins. All the tubes were bought from bargain sellers on Ebay and it is hard to know if they are new or used - I guess mostly used.
> 
> ...


 
  
 Hi mordy.
  
 (That's my favourite water lily colour , by the way!)...
  
 Anyway, re the TS 5687, it appears the _really_ early ones are by far the(ir) best....got any?!
  
 ps. If you _do_ manage to figure out the synergy thing, methinks you would become a millionaire OVERNIGHT, lol!!...So keep trying


----------



## mordy

Hi hypnos 1,
  
 I have three Tung Sol 5687 tubes, one with bronze plates from 1966, one black plate 1964, and another black plate unknown year (markings rubbed off). The two black plates look similar. There is a school of thought that the older the tube is, the better it sounds. It may very well be that the workmanship and quality control were better in the early tubes. On the other hand, Audiofanboy (remember him? - wonder what happened to him) advocated that later tubes may have benefited from continuous research and development. In general, I try to approach tubes without any preconceived ideas and let my ears judge.
  
 The black plate TS from '64 together with the two Sylvania 6080WB tubes sounds excellent at this time after burn in. This combination is just as good as the two Chatham 6AS7G with the Sylvania 5687 or Sylvania subminiature 7963. At first I thought that the Sylvania 6080's were used because they looked a little grimy and dirty. However, it could be that they just got dirty from lying around without boxes for several decades and they may be new.
  
 (Here is another purple water lily from two years ago - no connection to tubes other than beauty)

  
 The beautiful sound I am listening to cost me me $13 for the three tubes.


----------



## hypnos1

mordy said:


> Hi hypnos 1,
> 
> I have three Tung Sol 5687 tubes, one with bronze plates from 1966, one black plate 1964, and another black plate unknown year (markings rubbed off). The two black plates look similar. There is a school of thought that the older the tube is, the better it sounds. It may very well be that the workmanship and quality control were better in the early tubes. On the other hand, Audiofanboy (remember him? - wonder what happened to him) advocated that later tubes may have benefited from continuous research and development. In general, I try to approach tubes without any preconceived ideas and let my ears judge.
> 
> ...


 
  
 Hey, m...first you taunt me with wonderful memories of times in the Caribbean - viz the lilac-coloured lily, then with your uncanny ability to get good tubes for PEANUTS...have you no pity, lol?! 
	

	
	
		
		

		
			





.
  
 ps. You MUST share your guidance on how to get the deals over on the Feliks-Audio thread...PLEASE - it may well be needed to help any interested parties, especially to find some good "cheep cheep" 6SN7s!
  
 Cheers...


----------



## gibosi

mordy said:


> I have three Tung Sol 5687 tubes, one with bronze plates from 1966, one black plate 1964, and another black plate unknown year (markings rubbed off). The two black plates look similar. There is a school of thought that the older the tube is, the better it sounds. It may very well be that the workmanship and quality control were better in the early tubes. On the other hand, Audiofanboy (remember him? - wonder what happened to him) advocated that later tubes may have benefited from continuous research and development. In general, I try to approach tubes without any preconceived ideas and let my ears judge.


 
  
 I think there is no doubt that tubes benefited from continuous R&D. However, after a few iterations, most tubes likely reached a level where no further improvements were deemed necessary. Changes after that typically added features, such as higher peak voltage and power ratings for the 6SN7GTA and controlled heater warm-up in the 6SN7GTB (which didn't necessarily make them "better") or reduced the cost of production. Reducing the cost of production was especially important going into the 1960's and later. Solid state was the new state-of-the-art, and by that time many tubes had become mass-produced commodity items manufactured primarily to keep old tube equipment running. If you will, in the early tubes, changes were implemented to make them better. In the later tubes, changes were implemented to make them cheaper.
  
 So it is not at all clear to me that the very first version of a tube is the best. But it does make sense that the second, third and fourth versions may well be the best. Fortunately, I cannot afford first versions, but in my experience, tubes manufactured in the 1940's and through the '50's and very early '60's, when tubes were still state-of-the-art, often sound better than later tubes.
  
 All that said, Mordy's approach has considerable merit. The vast majority of these tubes were designed for use in IF, HF and VHf applications, and therefore, one cannot assume that the best VHF amplifier is going to be the best audio amplifier. Keeping an open mind can result in considerable savings and serendipitous treasures.


----------



## hypnos1

gibosi said:


> I think there is no doubt that tubes benefited from continuous R&D. However, after a few iterations, most tubes likely reached a level where no further improvements were deemed necessary. Changes after that typically added features, such as higher peak voltage and power ratings for the 6SN7GTA and controlled heater warm-up in the 6SN7GTB (which didn't necessarily make them "better") or reduced the cost of production. Reducing the cost of production was especially important going into the 1960's and later. Solid state was the new state-of-the-art, and by that time many tubes had become mass-produced commodity items manufactured primarily to keep old tube equipment running. If you will, in the early tubes, changes were implemented to make them better. In the later tubes, changes were implemented to make them cheaper.
> 
> So it is not at all clear to me that the very first version of a tube is the best. But it does make sense that the second, third and fourth versions may well be the best. Fortunately, I cannot afford first versions, but in my experience, tubes manufactured in the 1940's and through the '50's and very early '60's, when tubes were still state-of-the-art, often sound better than later tubes.
> 
> All that said, Mordy's approach has considerable merit. The vast majority of these tubes were designed for use in IF, HF and VHf applications, and therefore, one cannot assume that the best VHF amplifier is going to be the best audio amplifier. Keeping an open mind can result in considerable savings and serendipitous treasures.


 
  
 Nice one, gibosi


----------



## gibosi

A Telefunken PCC85 arrived today. As you might remember, this is a 9 volt VHF double triode, 9AQ8 in the US, used in television tuners as RF amplifiers and oscillators. The structure seems quite simple, with box plates and an electrostatic shield. This one was manufactured in Berlin, 1970, probably. The fourth digit is the year, "0", and this coding system was implemented by Telefunken in the late 1960's.
  

  
 Rummaging around among a lot of PCC88's I bought quite some time ago, I discovered that one of them was actually a PCC85! lol This one is a Valvo, manufactured in the Hamburg factory, in 1954, similar plates and shield, with a foil disc getter. I vaguely remember not being all that impressed with this tube, but then, I thought it was a PCC88 and was running it on 6.3V!
  

  
 The Telefunken is burning in and I expect to spend some time with these tubes over the next several days.


----------



## MIKELAP

Listening to some 6AV6 tubes sounded good back then still sound good now and as gibosi mentionned back then heres what to look for :                                                                                                                                                                                                                                                                                                       Of all the 6AV6 I have heard, the GE, Toshiba, FIVRE and Tung-Sol 6AV6 (and sisters, 6AT6 / 6AQ6) with box getters have the best sound stage, treble and detail. And further, after reading Mordy's observations, I think I can safely say that any 6AV6 with box-getters should be excellent.                                                                                                                                                                                                                                                                                                       And by the way those tubes are not plug &play first you need to be on EF91- 92 setting then you need to cut off pins 5 and 6 and cover the 2 pins youve just cut off  with electrical tape  and voilà your ready to rock& roll .


----------



## TrollDragon

mikelap said:


> Listening to some 6AV6 tubes sounded good back then still sound good now...


 
 Nice one, I might just do the same for a while.


----------



## mordy

If you don't want to move the jumpers underneath you can always do the 6-7 wire strap and leave the jumpers in the EF95 setting.
  
 EF91/92 = EF95 + 6/7-wire mod. See figure below.
  

  

  

 I still remember how I felt when I first stumbled across the box getter 6AV6 variants:
  




  
  
 Have not thought of making a comparison with the 5687 tube using 6080 power tubes, but now you piqued my interest. Wonder how they sound with heavy duty industrial grade 6080 backing?


----------



## MIKELAP

mordy said:


> If you don't want to move the jumpers underneath you can always do the 5-7 wire strap and leave the jumpers in the EF95 setting.
> 
> EF91/92 = EF95 + 6/7-wire mod. See figure below.
> 
> ...


 
 Thanks mordy for pointing that out i forgot about that, also if you dont want to freak out everytime you move jumpers get the long jumpers , man its really a night  and day difference lol.


----------



## mordy

I am sweating profusely. I always do when I change the jumpers underneath. Those little thingamajigs are torture for fumbly old hands and fingers with the added cold sweat feature of worrying about dropping one of them inside the amp. One came off easily, but the second didn't want to budge, but I finally got it out and placed both on the appropriate pins.
 I couldn't use the 6-7 wire strap since on this tube pin #6 is cut off.
  
 Thanks to my advanced storage system I was able to find the 6AV6 boxtop getter tubes within a few seconds. I have three pairs: Sylvania, Tung Sol and RCA + one Sylvania side getter. The RCA has an unusual "lollipop" style getter. Placing both tubes together makes them look like they have sunglasses on. My notes stated that they sounded the best, so I tried them.
  


 The right tube in the box looks like this:
  

  

 The box is in the shape of a silver box on top of the top mica. The side getter and brownish getter flash is also seen. This tube is marked C27. I think it is a Sylvania from March, 1962.
  
  
 How do the 6AV6 RCAs sound? "Sounded good back then, still sound good now." Concur; however, even though the sound stage may be a little wider than the TS 5687, the bass, although very musical and detailed, doesn't have the slam and punch and doesn't go as deep as the 5687. Will give it time for a final conclusion.
  

  
 I'll pop in the other two pairs later to see how it sounds with the 6080s.


----------



## MIKELAP

Got a question for 6hm5 owners do they all sound similar i have  a pair of G.E.'s, are the yugo's better sounding , no car pictures please lol


----------



## kvtaco17

mikelap said:


> Got a question for 6hm5 owners do they all sound similar i have  a pair of G.E.'s, are the yugo's better sounding , no car pictures please lol


 
 I disliked the GE's... the Yugo's were slightly tilted to the warm side and the Sylvania's were more neutral... the GE's sounded kinda thin... This is from memory...


----------



## TrollDragon

If you grab a pair of the Yugo 6HM5's MIKELAP, let me know how you like them and I'll grab a pair for myself.


----------



## Rossliew

I was just listening to my Mk3 st night with stock output tubes matched with the 6hm5 tubes driving hd600. My oh my, what glorious sound it makes! Palpable mids with punchy bass and smooth top end. 

TD, you should get a pair to try out. They are inexpensive.


----------



## TrollDragon

Thanks Rossliew that sounds good, I think I will!


----------



## Rossliew

Guys, are these tubes a direct replacement for the 6HM5 as mentioned by the seller? 
  
 http://www.ebay.com/itm/SLEEVE-OF-5-NEW-6HQ5-VHF-TRIODE-TUBES-VALVES-6HA5-6HK5-6HM5-/350575258704?pt=LH_DefaultDomain_0&hash=item519fe9ec50


----------



## gibosi

rossliew said:


> Guys, are these tubes a direct replacement for the 6HM5 as mentioned by the seller?
> 
> http://www.ebay.com/itm/SLEEVE-OF-5-NEW-6HQ5-VHF-TRIODE-TUBES-VALVES-6HA5-6HK5-6HM5-/350575258704?pt=LH_DefaultDomain_0&hash=item519fe9ec50


 
  
 Yes, these are very similar to the 6HM5, with the same pin-out, and in our LD's they are plug and play in the EF95 setting.


----------



## Rossliew

gibosi said:


> Yes, these are very similar to the 6HM5, with the same pin-out, and in our LD's they are plug and play in the EF95 setting.


 
 Great! thanks, G.
  
 Searching for cheap equivalents to try out and see if they sound similar to the Yugoslavian ones.


----------



## Rossliew

Are these the real deal? The price is pretty steep and I'm not familiar with these type of tubes..appreciate the eagle eyed amongst you to help out 
  
 http://www.ebay.com/itm/4pcs-NOS-Western-Electric-403A-6AK5-tubes-Square-getter-Original-box-6613-/321521428517?pt=Vintage_Electronics_R2&hash=item4adc2ba825


----------



## MIKELAP

About the Yugo's 6HM5 any special year to look for or there all good.


----------



## hypnos1

Hi guys.
  
 A while ago I decided to give a real cheap job a try just for fun, remember?...ie the Little Bear P8 (with metal case and toroidal transformer).
  
 Well, with 2x '50's TS 5687s (separate heater power supply and different pin-out to the stock 6N3P) driving a single Chatham 6AS7G, all I can say is... _unbelievable_!.. Better than the MKIV SE with any tubes up until the latest magical finds...I kid you not...CRAZY!!
  
 However (there's always a catch, no?) - even with just one 6AS7G, it gets far hotter than the LD...volume knob is at 3 o'clock as opposed to the LD's 10 or 11. And it obviously doesn't _really_ like the higher external heater power supply - pretty bad hum, which I can actually minimise by using myself as ground, via a wire attached to the tubes' centre tap, and completely by finger also placed on the amp's metal front plate...unconventional, but it works lol! (Better be careful I don't brush the pos., though!
	

	
	
		
		

		
			





)...Next step is to attach said wire direct to said metal front, and see what happens...
  
 Anyway, these niggles notwithstanding, for anyone prepared to do the necessary this represents tremendous value-for-money, methinks...
  
 Here she is, next to big brother...and as per gibosi and mordy, giving new meaning to "flying by wire"!! (might get round to making some proper adapters later - all depends on the Feliks project...).
  
 (To eliminate the need for external power supply, I might just have a go with some nice 6N23Ps...)
  
.
  
 Edit...Correction...the 5687s in at present are the Raytheons...and very good they are too 
	

	
	
		
		

		
		
	


	




.
  
 I know this is VERY unfair, but there isn't quite the 3D 'holographic' sound of the modded LD, nor same level of detail...but hey, you want blood?!!


----------



## hypnos1

mikelap said:


> About the Yugo's 6HM5 any special year to look for or there all good.


 
  
 I think they're ALL very good, MIKELAP...anyone else got any different findings?


----------



## MIKELAP

hypnos1 said:


> I think they're ALL very good, MIKELAP...anyone else got any different findings?


 
 Just found this, the best ones are the  tall bottles not the short ones.


----------



## MIKELAP

Can any of you guys access Ebay over here i cant .


----------



## TrollDragon

These are the ones you want but it looks like all of his listings have been removed...


----------



## Rossliew

I can't access Ebay here as well..Mikelap, look for the Yugoslavian ones.
  
 Having said that, I'm keen to try the other variations from the US and EU..


----------



## hypnos1

mikelap said:


> Just found this, the best ones are the  tall bottles not the short ones.


 
  
 Hi again, M.
  
 I think you'll find all the 'yugos' are tall-bottled


----------



## TrollDragon

Hey MIKELAP it looks like his stuff is back online...
 www.ebay.ca/itm/6HM5-6HA5-EC900-export-quality-audio-triode-tube-NOS-FREE-SHIPPING-/300879467071


----------



## gibosi

rossliew said:


> I can't access Ebay here as well..Mikelap, look for the Yugoslavian ones.
> 
> Having said that, I'm keen to try the other variations from the US and EU..


 
  
 As far as I know, GE did not manufacture the 6HM5. However, they did sell relabeled tubes. I found two different versions of GE relabels, both apparently manufactured in GB. One carries Philips/Mullard codes and the other does not. Moreover, they sound different, the relabeled Mullard being just a bit warmer.
  
 I never got around to purchasing the Yugos, but would assume that they sound similar to the GE/Mullards.
  
 GE 6HM5, original manufacturer unknown
  




  
 GE 6HM5, relabeled Mullard


----------



## Rossliew

gibosi said:


> As far as I know, GE did not manufacture the 6HM5. However, they did sell relabeled tubes. I found two different versions of GE relabels, both apparently manufactured in GB. One carries Philips/Mullard codes and the other does not. Moreover, they sound different, the relabeled Mullard being just a bit warmer.
> 
> I never got around to purchasing the Yugos, but would assume that they sound similar to the GE/Mullards.
> 
> ...


 
  
 Thanks, G. From eBay i saw some equivalents which are shorter than the Yugos ones..have you tried those before? If i remember correctly, some were Amperex and Admiral branded..


----------



## gibosi

rossliew said:


> Thanks, G. From eBay i saw some equivalents which are shorter than the Yugos ones..have you tried those before? If i remember correctly, some were Telefunken (eBay is still down for me) branded..


 
  
 I tried the short squat tubes and found them to be nowhere near as good as the tall ones. As I recall, the short ones were manufactured by Siemens, but resold under many other labels.


----------



## kvtaco17

http://www.ebay.com/itm/6HM5-6HA5-EC900-export-quality-audio-triode-tube-NOS-FREE-SHIPPING-/300879467071?pt=Vintage_Electronics_R2&hash=item460dd0523f
  
 is what you guys want!


----------



## MIKELAP

trolldragon said:


> Hey MIKELAP it looks like his stuff is back online...
> www.ebay.ca/itm/6HM5-6HA5-EC900-export-quality-audio-triode-tube-NOS-FREE-SHIPPING-/300879467071


 
 Bought these 10 6HM5 yugos on this site they come out to $3.90each .i offered $35.00 He countered with a $39.00 bid                http://www.ebay.com/itm/251609948341?_trksid=p2059210.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT


----------



## Rossliew

gibosi said:


> I tried the short squat tubes and found them to be nowhere near as good as the tall ones. As I recall, the short ones were manufactured by Siemens, but resold under many other labels.


 
 OK, that saved me some money LOL! Thanks again!
  
 On a side note, I found that the 6SN7/6HM5 combo didn't sound as punchy nor aggressive as the 6H6N/6HM5 combo. In the latter, the treble was more extended and it brought more energy to the recording with punchier bass whilst the former combo smoothed the highs a tad - creamier for lack of a better word.
  
 Anyone feel the same?


----------



## TrollDragon

mikelap said:


> Bought these 10 6HM5 yugos on this site they come out to $3.90each .i offered $35.00 He countered with a $39.00 bid                http://www.ebay.com/itm/251609948341?_trksid=p2059210.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT


 

 Nice Grab!


----------



## gibosi

rossliew said:


> OK, that saved me some money LOL! Thanks again!
> 
> On a side note, I found that the 6SN7/6HM5 combo didn't sound as punchy nor aggressive as the 6H6N/6HM5 combo. In the latter, the treble was more extended and it brought more energy to the recording with punchier bass whilst the former combo smoothed the highs a tad - creamier for lack of a better word.
> 
> Anyone feel the same?


 
  
 There are many, many 6SN7's.... And many sound very different....  Which ones are you using for powers?


----------



## Rossliew

gibosi said:


> There are many, many 6SN7's.... And many sound very different....  Which ones are you using for powers?


 
 The ones I have says the following :
  
 "JAN CKR 6SN7GT" and below it states Ken-Rad USA VT-231.


----------



## gibosi

rossliew said:


> The ones I have says the following :
> 
> "JAN CKR 6SN7GT" and below it states Ken-Rad USA VT-231.


 
  
 The Ken-Rad's have great bass but rather subdued highs. "Creamy" is a good word.....  I suggest you try a pair of Sylvanias or Raytheons for a little more punch and airier highs. The Tung-Sol mouse ears are very balanced and might be worth trying as well.


----------



## Rossliew

gibosi said:


> The Ken-Rad's have great bass but rather subdued highs. "Creamy" is a good word.....  I suggest you try a pair of Sylvanias or Raytheons for a little more punch and airier highs. The Tung-Sol mouse ears are very balanced and might be worth trying as well.


 
 Great advice there again, G. I have found some mouse ears on Ebay and keen to get a pair to try out.


----------



## Rossliew

gibosi said:


> The Ken-Rad's have great bass but rather subdued highs. "Creamy" is a good word.....  I suggest you try a pair of Sylvanias or Raytheons for a little more punch and airier highs. The Tung-Sol mouse ears are very balanced and might be worth trying as well.


 
 http://www.ebay.com/itm/Sylvania-1956-vintage-tall-6SN7GTB-vacuum-tubes-matched-and-ultra-quiet-/111330100983?pt=Vintage_Electronics_R2&hash=item19ebca86f7
  
 How do i tell if the above are genuine Sylvanias as claimed by the seller?


----------



## MIKELAP

You guys use these is that a good price you can also make an offer  if anyone is interested heres the link           http://www.ebay.com/itm/Siemens-C3m-platinum-matched-pair-NOS-NIB-made-in-W-Germany-/261493572835


----------



## Rossliew

MIKELAP - i think the guys here use c3g/c3gs with an adapter...not sure about the plug n play possibility of the c3m though.


----------



## gibosi

Spoiler: PCC85



http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/7395#post_10875163


 Have been able to spend some time with the Telefunken and Valvo PCC85. Unfortunately, the Valvo is defective. One side is noticeably weaker than the other, which is too bad, as it still sounds pretty good. However, the Telefunken is very, very good. I spent several hours with it Friday and Saturday night, just listening to music. There is nothing I don't like about this tube. And given that I paid only $10 for it, I couldn't be more pleased. 
  
 Obviously, I got a very good deal on this tube, but even so, if someone would like to have a "real" Telefunken, these are rather plentiful, and if one is patient, I am sure there will be more good deals in the future. I also found a GE manufactured in GB and a Sylvania manufactured in Holland. The pictures were too poor to see any Philips production codes, but for less than $5 each, who cares? lol 
  
 Again, these are 9V tubes, most people can't use them, and they are cheap.


----------



## gibosi

rossliew said:


> http://www.ebay.com/itm/Sylvania-1956-vintage-tall-6SN7GTB-vacuum-tubes-matched-and-ultra-quiet-/111330100983?pt=Vintage_Electronics_R2&hash=item19ebca86f7
> 
> How do i tell if the above are genuine Sylvanias as claimed by the seller?


 
  
 Sylvania's factory code is 312, so these are genuine. And the date codes are the same 613, so the 13th week of 1956.


----------



## gibosi

mikelap said:


> You guys use these is that a good price you can also make an offer  if anyone is interested heres the link           http://www.ebay.com/itm/Siemens-C3m-platinum-matched-pair-NOS-NIB-made-in-W-Germany-/261493572835


 
  
 With an adapter, these are plug and play. 
  
 $69 for a pair has been the going price for quite some time. So not a good deal, but not a ripoff either.


----------



## TrollDragon

Don't the C3m's have 20V heaters?


----------



## gibosi

trolldragon said:


> Don't the C3m's have 20V heaters?


 
  
 Oh! My sleepy eyes didn't catch this! Yes, these have 20V heaters, and so definitely not plug and play!
  
 The C3g is plug and play with an adapter.
  
 Thanks for catching this!


----------



## mordy

Here is a link to a pair of Sylvanias 6SN7GTB (used) for $12.50 incl shipping -  why pay $70/pair? Try them, and if you like them, shop for a NOS pair at the right price if you want new tubes.
  
 http://www.ebay.com/itm/Pair-Used-6SN7GTB-Sylvania-Black-T-Plate-Halo-Getter-gm-Good-Match-/131207978618?pt=Vintage_Electronics_R2&hash=item1e8c9ade7a
  
 Sylvania sold many tubes under other names, and if the factory code is 312 it is a Sylvania. It is possible to get good deals using other brand names.
  
 Here is an offer for 5 used C3m Lorenz tubes for EUR 18.00
  
 http://www.ebay.de/itm/Lorenz-Tube-Radiorohre-5-x-C3m-/231308467346?pt=R%C3%B6hren&hash=item35db0f1c92


----------



## Rossliew

gibosi said:


> Sylvania's factory code is 312, so these are genuine. And the date codes are the same 613, so the 13th week of 1956.


 
 Thanks, G!


----------



## Rossliew

mordy said:


> Here is a link to a pair of Sylvanias 6SN7GTB (used) for $12.50 incl shipping -  why pay $70/pair? Try them, and if you like them, shop for a NOS pair at the right price if you want new tubes.
> 
> http://www.ebay.com/itm/Pair-Used-6SN7GTB-Sylvania-Black-T-Plate-Halo-Getter-gm-Good-Match-/131207978618?pt=Vintage_Electronics_R2&hash=item1e8c9ade7a
> 
> Sylvania sold many tubes under other names, and if the factory code is 312 it is a Sylvania. It is possible to get good deals using other brand names.


 
 Thanks, Mordy!


----------



## Rossliew

Unfortunately the seller does not ship to Malaysia  I shall try to ask if he will make an exception.
  
 Sorry, where do you see the factory code ? I don't seem to see any markings on the tubes..


----------



## gibosi

rossliew said:


> Sorry, where do you see the factory code ? I don't seem to see any markings on the tubes..


 
  
 The tubes you linked to earlier:
  
 http://www.ebay.com/itm/Sylvania-1956-vintage-tall-6SN7GTB-vacuum-tubes-matched-and-ultra-quiet-/111330100983?pt=Vintage_Electronics_R2&hash=item19ebca86f7
  
 The second picture shows the tube codes.
  
 On the first tube, the codes are vertical
  
 3  6
 1  1
 2  3
  
 And on the second tube, horizontal
  
 312612


----------



## Rossliew

gibosi said:


> The tubes you linked to earlier:
> 
> http://www.ebay.com/itm/Sylvania-1956-vintage-tall-6SN7GTB-vacuum-tubes-matched-and-ultra-quiet-/111330100983?pt=Vintage_Electronics_R2&hash=item19ebca86f7
> 
> ...


 
 OK, i see it now! Some tubes do not have these markings so we won't be sure then. Looks like i need to find those with markings to be doubly sure.


----------



## gibosi

rossliew said:


> OK, i see it now! Some tubes do not have these markings so we won't be sure then. Looks like i need to find those with markings to be doubly sure.


 
  
 If they are labeled Sylvania, then you can be reasonably sure they really are Sylvania. These are way to common to encourage anyone to go to the trouble to make fakes. And there are some construction details that are helpful. Every Sylvania I have seen has black plates. Further, except for a few 6SN7GT's manufactured in the 1940's and early 1950's, the vast majority of Sylvanias, especially the GTA's and GTB's, have chrome tops. The GTB's linked to by Mordy, are classic examples.
  
 Search eBay for Sylvania 6SN7 and after looking at a bunch of them, you will soon be able to recognize these tubes, and also be able to differentiate them from the VT-231 types with clear tops, black plates and bottom getters.
  
 So when you are looking at rebrands, black plates and chrome tops pretty much narrows it down to Sylvania. And fortunately, rebrands often have the standard Sylvania manufacturer and date codes.


----------



## mordy

Here is an update on my excursion into the past, comparing three different pairs of box top getters 6AV6 triodes to a Tung Sol 5687 dual triode. Power tubes for this comparo are a pair of 60's Sylvania 6080WB.
  
 All the 6AV6 tubes have very nice mid range and treble, but they seem to be running out of steam in the bass in comparison to the 5687. The best sounding pair is the RCA, followed by the Sylvania and lastly by the Tung Sol. The RCA and Sylvania are musical and sweet, but lack the heft and authority in the bass. The TS sounded slower and had a more woolly and loose bass than the others.
  
 Time for a change again. Pulled out the the tubes and changed the jumpers from EF92 to EF95 settings no sweat, plugged in the Vectors and the 5687 with the 12.6V voltage regulator and PS. With this tube it sounds like you added a sub woofer; it goes so much lower in the bass, and the bass is much better defined with great slam and attack. The treble also has more sizzle and power.
  
 I figured out that I must have spent around $120 or more on adapters (two Vectors, two octal to 6N6P, two 9pin socket extenders), two voltage regulators 5A and 15A, a laptop power supply and a PC 430W 12 V PS, two computer fans and a 9pin breadboard. It is well worth it because of the tremendous upgrade in the sound.
  
 So long 6AV6 - the 5687 is the clear winner in this comparo.


----------



## Rossliew

mordy said:


> Here is an update on my excursion into the past, comparing three different pairs of box top getters 6AV6 triodes to a Tung Sol 5687 dual triode. Power tubes for this comparo are a pair of 60's Sylvania 6080WB.
> 
> All the 6AV6 tubes have very nice mid range and treble, but they seem to be running out of steam in the bass in comparison to the 5687. The best sounding pair is the RCA, followed by the Sylvania and lastly by the Tung Sol. The RCA and Sylvania are musical and sweet, but lack the heft and authority in the bass. The TS sounded slower and had a more woolly and loose bass than the others.
> 
> ...


 
 If you want to sell your adaptors, voltage regulators, PS, breadboard, etc...i may consider taking them off your hands


----------



## gibosi

mordy said:


> Here is an update on my excursion into the past, comparing three different pairs of box top getters 6AV6 triodes to a Tung Sol 5687 dual triode. Power tubes for this comparo are a pair of 60's Sylvania 6080WB.


 
  
 Very interesting, but I am not at all surprised. My 1950's GE 6AV6 were my favorite tubes up until I started to roll double triodes. But after my first session with an Amperex Orange Globe, there was no turning back. In my opinion, the GE 6AV6 is superior to the GE/Mullard 6HM5, but no match for a good double triode.


----------



## mordy

Concur - the allure of the 6HM5 is that it is a straight plug and play tube, and it doesn't require any modifications to use. The superior box top 6AV6 require cutting off and taping pins 5&6, and changing the jumpers from the EF95 to the EF92 setting.
  
 The dual triodes require much more extensive modifications with a breadboard and adapters + external power sources in some cases. However, the efforts are rewarded with superior sound. There is no turning back....


----------



## i luvmusic 2

hypnos1 said:


> Hi guys.
> 
> A while ago I decided to give a real cheap job a try just for fun, remember?...ie the Little Bear P8 (with metal case and toroidal transformer).
> 
> ...


 
 Did you hard wire your HEADPHONE into your AMP?


----------



## i luvmusic 2

One of my Favourite Plug and play tube is the GE JAN 5654W but IMO not better than 6HM5,How i miss those days using those tubes now they are Dust Collectors.


----------



## mordy

You may be able to sell them old dusty tubes on Ebay - seems a number of people only read the first posts on this forum......LOL


----------



## hypnos1

i luvmusic 2 said:


> Did you hard wire your HEADPHONE into your AMP?


 
  
 Hi ilm2.
  
 Yep, I sure did - out of necessity, originally!...After MUCH searching to find the cause of break-up in the left channel, I finally traced it to the "upgraded" Neutrik jack socket of the LD.
  
 Being VERY unimpressed with its quality I decided to go by the principle of "the best connector is NO connector"! and soldered direct to the amp...and there was a definite improvement in sound (despite a certain amount of derision from some over on another thread... and who undoubtedly had never tried this before passing opinion, lol).
  
 Of course, this is only OK if sticking to one set of 'phones! - Why oh why isn't there standardised fitment into different cups?...That would be FAR too convenient, methinks!...
  
 Another niggle is if using as pre-amp - because of hum, my main amp needs to be on low volume and the LD turned up, which means remembering to unplug at the phone's cups (HD650s)...OR ELSE!! 
	

	
	
		
		

		
			




  
 Would love to know if anyone else has done this, and their findings...


----------



## Rossliew

You peeps are HARDCORE! 
	

	
	
		
		

		
		
	


	




  LOL


----------



## hypnos1

rossliew said:


> You peeps are HARDCORE!
> 
> 
> 
> ...


 
  
 You bet, *R!!*...


----------



## i luvmusic 2

hypnos1 said:


> i luvmusic 2 said:
> 
> 
> > Did you hard wire your HEADPHONE into your AMP?
> ...


 
 I do the same when using the MK III as a pre amp volume way up on the MK III and control the volume level on the other amp.


----------



## superdux

After Gibosi had sent me some tips on what other tubes i can try with my adapter from MIKELAP i bought some cheap silver shield 79's Voskhod 6N23P.
I was surprised from their detail and was very happy with the bass too.Guess there are some more tubes to try but first i have to save a bit.
One question though: does USED TST NOS mean a used tube and after testing it's considered to be as new old stock?


----------



## gibosi

superdux said:


> One question though: does USED TST NOS mean a used tube and after testing it's considered to be as new old stock?


 
  
 Yes, the seller believes the tube is used, but it measures brand new. These tubes are usually a bit cheaper than new and never used, but they should last just as long.


----------



## MIKELAP

Going thru the old stock again listening to some 6AU6 G.E.Tektronix tubes nice detail got those from Audiofanboy a while back  .


----------



## TrollDragon

I am as well, reliving some glorious Cold War era Svetlana made 6Ж5П's out to the Fostex T50RP's.


----------



## MIKELAP

trolldragon said:


> I am as well, reliving some glorious Cold War era Svetlana made 6Ж5П's out to the Fostex T50RP's.


 
 How do those Fostex and new cable sound with MK4


----------



## MIKELAP

superdux said:


> After Gibosi had sent me some tips on what other tubes i can try with my adapter from MIKELAP i bought some cheap silver shield 79's Voskhod 6N23P.
> I was surprised from their detail and was very happy with the bass too.Guess there are some more tubes to try but first i have to save a bit.
> One question though: does USED TST NOS mean a used tube and after testing it's considered to be as new old stock?


 
 That's a good idea I like those tubes they sound very good as a matter of fact im also listening to some 70's 6N23P  .


----------



## kvtaco17

Blast from the past today!
  
 Currently running 2 Raytheon 6CG7's as power tubes and a pair of 6HM5 Yugo's I had lying around in my MK3 and it sound pretty darn good for a budget setup!


----------



## TrollDragon

mikelap said:


> How do those Fostex and new cable sound with MK4


 
  
 The T50RP's with my adaptation of the BMF DBV 3 Mod.

  

 The new cable is a 4 conductor braid of 140 Strand / 44 AWG Litz type 2 wire, terminated with Tiny xlr plugs and a Toxic Cable carbon fibre 6.5mm TRS plug.
  
 These are orthodynamic drivers so they are fast with a great clarity. The stock T50RP's sound flat and lifeless out of the box, you would only get a pair of these if you wanted to mod them into a better sounding headphone. You can adjust the bass and treble to your liking depending on the mods involved. My mod provides just enough bass, a treble that is not bright and these come with excellent mids by default. The sound takes a bit getting of use to, but after you listen for a while they are quite impressive for a $139 headphone.
  
 At 50Ω, 98 dB/mW and can handle a maximum of 3W, they do require a little power to bring them up to their potential and the Little Dot does a superb job.
  
 Here is the FIMM thread for those that are interested in modding a pair, or you can just go buy a pair of Mad Dogs if you don't.


----------



## MIKELAP

kvtaco17 said:


> Blast from the past today!
> 
> Currently running 2 Raytheon 6CG7's as power tubes and a pair of 6HM5 Yugo's I had lying around in my MK3 and it sound pretty darn good for a budget setup!


 
 Ordered some 6HM5 Yugo's this week should sound nice.


----------



## Rossliew

mikelap said:


> Ordered some 6HM5 Yugo's this week should sound nice.


 
 You will enjoy them, M !!


----------



## hypnos1

mikelap said:


> Ordered some 6HM5 Yugo's this week should sound nice.


 
  
  


rossliew said:


> You will enjoy them, M !!


 
  
 Hi guys.
  
 Popped mine in too a while back...and quickly popped the C3GSs back in LOL!!  
	

	
	
		
		

		
			




  
 Hit those credit cards, boys - you only live once


----------



## gibosi

6HN5... 6AV6.... I just can't persuade myself to go back that far.... lol... 
  
 But regarding the 6N23P, I am currently listening to a 1975 Reflektor 6N23P, silver shield, single wire getter post, and it is the best 6N23P I have ever heard. Moreover, it is the best 6DJ8-type tube I have ever heard. These are difficult to come by, but this tube is one of my top three favorites, along with the Sylvania 6SN7W and the Siemens C3g.


----------



## gibosi

Now, something new. Have been wanting to try a 7044. These have the same pinout as the 5687 and 7119/E182CC. And like the 5687, it has 0.9A heaters. There haven't been many of these on eBay, and often, they cost more than I wanted to pay, just to try one out. Finally found a Sylvania 7044, relabeled as an IBM, for $15/shipped. My guess is this was manufactured in the 26th week of 1960. I haven't been able to find out when this tube was first introduced, but the 5687 and 7119/E182CC were introduced around 1957, so my assumption is that this tube was introduced at about that time, and couldn't have been manufactured as early as 1950.
  

  
 I also received a couple of cheap 9AQ8/PCC85, $5 each, one manufactured in Heerlen and the other in Japan.....


----------



## i luvmusic 2

trolldragon said:


> mikelap said:
> 
> 
> > How do those Fostex and new cable sound with MK4
> ...


 
 WOW!That looks really good i like the pads and the cable,That should be a nice HP for the S.E.X.
 Where did you get the paracord?


----------



## TrollDragon

i luvmusic 2 said:


> WOW!That looks really good i like the pads and the cable,That should be a nice HP for the S.E.X.


 
 Thanks ILM2!
  
 Those are Shure 840 memory foam pads and you can put them on just about anything with a 100mm cup diameter, the thick HM5 pads just don't quite fit the T50RP's.
 Stax 02 pads will fit as well but their price ramps up quite quickly, I might get a pair of Alpha Dog pads for them from Mr. Speakers down the road.
  
 T50RP's will sound good on anything that has a bit of ballz to it.


----------



## MIKELAP

gibosi said:


> 6HN5... 6AV6.... I just can't persuade myself to go back that far.... lol...
> 
> But regarding the 6N23P, I am currently listening to a 1975 Reflektor 6N23P, silver shield, single wire getter post, and it is the best 6N23P I have ever heard. Moreover, it is the best 6DJ8-type tube I have ever heard. These are difficult to come by, but this tube is one of my top three favorites, along with the Sylvania 6SN7W and the Siemens C3g.


 
 Hey gibosi Is the wire round or is it flat like so .    Thanks


----------



## i luvmusic 2

trolldragon said:


> i luvmusic 2 said:
> 
> 
> > WOW!That looks really good i like the pads and the cable,That should be a nice HP for the S.E.X.
> ...


 
 THANKS!  i think the SEX have enough Balls 2W per channel.


----------



## gibosi

mikelap said:


> Hey gibosi Is the wire round or is it flat like so .    Thanks


 
  
 There are two different getter post structures found in 1970's 6N23P manufactured by Voskhod and Reflektor. On the left, the getter post is a single piece of wire attached to that part of the shield which extends above the top mica. And on the right, the getter post appears to be a flat sheetmetal extension of the side of the shield. In the Voskhods, this design change occurred in 1975. The wire getter post is found in tubes from early 1975, and before. And the flat sheetmetal getter post is found in tubes from late 1975, and after. Both of these tubes are 1975 Voskhods. I prefer the late 1975 Voskhod, with the flat sheetmetal getter post to the earlier one. And I prefer the 1975 Reflektor, with single wire getter post over the Voskhods.


----------



## kvtaco17

Just a little tip... Tung-Sol round plate, 6SN7/VT231 = godly in anything as a driver... even our little dot's...


----------



## Rossliew

hypnos1 said:


> There doesnt seem to be any c3gs tubes for sale on ebay now. H, any spares to sell?
> 
> 
> Hi guys.
> ...


----------



## Rossliew

gibosi said:


> Now, something new. Have been wanting to try a 7044. These have the same pinout as the 5687 and 7119/E182CC. And like the 5687, it has 0.9A heaters. There haven't been many of these on eBay, and often, they cost more than I wanted to pay, just to try one out. Finally found a Sylvania 7044, relabeled as an IBM, for $15/shipped. My guess is this was manufactured in the 26th week of 1960. I haven't been able to find out when this tube was first introduced, but the 5687 and 7119/E182CC were introduced around 1957, so my assumption is that this tube was introduced at about that time, and couldn't have been manufactured as early as 1950.
> 
> 
> 
> ...




As the 7044 tubes have a heater current of 0.9A, are they plug and play with the LD Mk3 (with an adaptor)?


----------



## Oskari

gibosi said:


> Finally found a Sylvania 7044, relabeled as an IBM, for $15/shipped. My guess is this was manufactured in the 26th week of 1960. I haven't been able to find out when this tube was first introduced, but the 5687 and 7119/E182CC were introduced around 1957, so my assumption is that this tube was introduced at about that time, and couldn't have been manufactured as early as 1950.


 
  
 Tube Lore gives a 1957 registration date for the type.


----------



## gibosi

rossliew said:


> As the 7044 tubes have a heater current of 0.9A, are they plug and play with the LD Mk3 (with an adaptor)?


 
  
 The general consensus is that any tube drawing less than 0.45A is safe. So, the 7044 and 5687, at 0.9A, and the 7119/E183CC at 0.6A are not plug and play without an external heater power supply.


----------



## gibosi

oskari said:


> Tube Lore gives a 1957 registration date for the type.


 
  
 Good to know that my guess was correct. Thanks!


----------



## mordy

Took up the 6N23P challenge and popped one in. I have four identical Voskhod tubes from Aug 1974. They have a single round wire post for the getter and no silver shields. Powered by the 6080 Sylvanias they sound very good; the bass and treble is a little softer than the 5687.
  
 The 6N23P needed some warm up to come to its best. It runs very cool - you can barely feel the tube being warm, whereas the 5687 runs very hot. This tube is really very good, and I could see how it would perform very well in certain systems.
  
 Bought these "lightly used" tubes from a Russian seller. It took several emails and Google translate to make him understand the years of manufacture I wanted. He finally offered me 1977 tubes. I also ordered a 6N9C/6SL7 tube to save on the shipping. All emails were in English and Russian from me, and he answered in broken English. In the end I got 1974 tubes instead of the 1977 tubes. In addition to the 6N9C tube he threw in an additional 6N9C without markings. All this shows that Google translate works, sort of....Paid around $4 each incl shipping. Checking today I found a seller in Moldova who could sell you four used ones for $16 incl shipping.
  
 Before trying the 6N23P i was listening to a GE 5687WA. I have not found a way to decipher the dots on the tube, but I think I am in good company here since nobody else has been able to interpret what the dots mean. This tube is physically a little taller than the regular 5687 tubes. People seem to prefer the Sylvanias, Tung Sols and Raytheons, but this tube after burn-in sounds superb on a 12.6V diet.
  
 It is amazing how many really good inexpensive tubes we have unearthed. To use the 6N23P dual triode you need a 9pin breadboard and two vector adapters and some 22 gauge wire. That's it - no soldering needed, just a small flat blade screw driver. Try it - you won't regret it.


----------



## Rossliew

gibosi said:


> The general consensus is that any tube drawing less than 0.45A is safe. So, the 7044 and 5687, at 0.9A, and the 7119/E183CC at 0.6A are not plug and play without an external heater power supply.


 
 Thanks, Gibosi!
  
 For a moment there, I thought I had other interesting tubes to try out without hassles of an external PSU.


----------



## mordy

*Congratulations to all! We have reached page 500!*


----------



## MIKELAP

mordy said:


> *Congratulations to all! We have reached page 500!*


----------



## gibosi

rossliew said:


> For a moment there, I thought I had other interesting tubes to try out without hassles of an external PSU.


 
  
 Actually, there is another tube you can try out with the stock LD heaters and your 12AX7 double triode adapter. However, you will need a pin-converter:
  
 http://www.ebay.com/itm/1-pcs-Adapter-396A-5670-12AU7-tubes-SUB-/261395051589?
  
 You can find this tube listed under these designations: 2C51 / 396A / 5670, and the Russian equivalent is 6N3P.


----------



## Rossliew

gibosi said:


> Actually, there is another tube you can try out with the stock LD heaters and your 12AX7 double triode adapter. However, you will need a pin-converter:
> 
> http://www.ebay.com/itm/1-pcs-Adapter-396A-5670-12AU7-tubes-SUB-/261395051589?
> 
> You can find this tube listed under these designations: 2C51 / 396A / 5670, and the Russian equivalent is 6N3P.


 
 Where can one obtain the 12AX7 double triode adapter?  Thanks for the link though!
  
 Sorry, did you mean I can use the linked adaptor and the 2C51/396A/5670 tubes immediately, similar to what we can do using 6SN7 tubes?


----------



## gibosi

rossliew said:


> Where can one obtain the 12AX7 double triode adapter?  Thanks for the link though!
> 
> Sorry, did you mean I can use the linked adaptor and the 2C51/396A/5670 tubes immediately, similar to what we can do using 6SN7 tubes?


 
  
 Sorry...  I have trouble keeping track of everyone's configuration, and for some reason I thought you already had a 12AX7 adapter....   To use these as drivers, you need a 9pin breadboard, two Vector test sockets and some hookup wire. But no external PS is required. Easy. 
  
 I think you are using 6SN7's as powers? These 2C51's have 0.3A heaters, so not enough power I believe....
  
 However, the 6N1P and 6N5P, with 0.6A heaters, should work fine as powers and no pin-adapters are necessary. And the 5687 and 7044, with 0.9A heaters should also work fine as powers, but you will need a pin-adapter.
  
 http://www.ebay.com/itm/1x-5687-to-6N6-6N1-6N2-6N6-6N11-ECC88-E88CC-Vacuum-tube-adapter-socket-converter-/321472393335?


----------



## Rossliew

gibosi said:


> Sorry...  I have trouble keeping track of everyone's configuration, and for some reason I thought you already had a 12AX7 adapter....   To use these as drivers, you need a 9pin breadboard, two Vector test sockets and some hookup wire. But no external PS is required. Easy.
> 
> I think you are using 6SN7's as powers? These 2C51's have 0.3A heaters, so not enough power I believe....
> 
> ...


 
  
 No worries, G 
  
 Yes, am using 6SN7s as powers.
  
 Let me try to get this correct - for the 6N1P tubes, i can just plug and play without adapters? But for the 5687/7044 tubes, I need to get the 5687 to 6N6 adapters as per the link you provided, correct?


----------



## Rossliew

Can i use this adapter to connect a 6922/6N1P/ECC88 tube to my 6CG7-to-6SN7 adapter plugged into the LD Mk 3?
  
 http://www.ebay.com/itm/1x-ECC88-6DJ8-6922-to-6SN7-Vacuum-tube-adapter-socket-converter-/301018619572?pt=Vintage_Electronics_R2&hash=item46161b9eb4


----------



## gibosi

rossliew said:


> Yes, am using 6SN7s as powers.
> 
> Let me try to get this correct - for the 6N1P tubes, i can just plug and play without adapters? But for the 5687/7044 tubes, I need to get the 5687 to 6N6 adapters as per the link you provided, correct?


 
  
 Yes, the 6N1P has the same pin-out as the 6N30P, so they are plug and play, no adapters required. The 5687/7044 tubes have a different pin-out, so pin-adapters are required.


----------



## Rossliew

gibosi said:


> Yes, the 6N1P has the same pin-out as the 6N30P, so they are plug and play, no adapters required. The 5687/7044 tubes have a different pin-out, so pin-adapters are required.


 
 That is just wonderful! I have many 6N1Ps & its variants so i can roll even MOAR tubes now! 
	

	
	
		
		

		
			




  
 You just made my day, G! Now, lets see if they sound nice as power tubes..impressions to come!


----------



## Rossliew

Listening with a pair of Sylvania 6N1Ps as power tubes with a pair of Russian 6ZH1Ps - taut, punchy bass with prominent mids. Upon further listening, i would think the soundstage is slightly compressed. Nothing too bad really. I consider it more intimate a presentation. For me, so long as the bass is punchy, I'm happy


----------



## gibosi

rossliew said:


> Listening with a pair of Sylvania 6N1Ps as power tubes with a pair of Russian 6ZH1Ps - taut, punchy bass with prominent mids. Upon further listening, i would think the soundstage is slightly compressed. Nothing too bad really. I consider it more intimate a presentation. For me, so long as the bass is punchy, I'm happy


 
  
 Sylvania? But the 6N1P is a Russian tube.....


----------



## Rossliew

gibosi said:


> Yes, the 6N1P has the same pin-out as the 6N30P, so they are plug and play, no adapters required. The 5687/7044 tubes have a different pin-out, so pin-adapters are required.


 
 Oops..i noticed from your earlier replies that the 6N1Ps draw 0.6A and the 5687 tubes draw 0.9A and we need an external PSU to make them work...gasp! 
  
 I just plugged in the 6N1Ps into the socket without any external PSU - will I kill the amp?? But it sounds so good...


----------



## Rossliew

gibosi said:


> Sylvania? But the 6N1P is a Russian tube.....


 
 My bad...i think its a 6922 variant..or one of those


----------



## mordy

Hi,
  
 After trying the Russian 6N23P tube I dipped into my box of 6DJ8 derivatives. Fished out a rebranded Sylvania 6BC8 tube from Oct 1965 that I had marked as superb sounding. Guess what? With the 6080 power tubes this tube is even better than the 6N23P - more musical and better bass. They are very close though; the 6N23P is brighter with wider sound stage and a little more detail, but as said, not as musical.
  
 A quick look at Ebay shows many very inexpensive offerings of the 6BC8 tube. You could buy this tube incl shipping for just a few dollars. Highly recommended!
  
 In comparison, the Sylvania sub miniature 7963 is brighter than the 6N23P; otherwise sounds similar.
  
 Now time for a quick engine change - I have two Vector set-ups. One is for 6DJ8 tubes and one for 12AX7 tubes. The latter works for octal tubes with an adapter, as well for the 5687 tube with a simple rewiring.
  
 Popped in the GE 55687WA, connected the 12.6V PS and listened again. At this time the 5687 is my personal favorite. In comparison with the above tubes it has better instrument separation and more slam in the bass, more sizzle in the treble and overall great performance, attack and quickness.
  
 It could very well be that each one of the above tubes will work the best in a certain set-up. It's a matter of taste and individual equipment, but they all are safe best bets. And none of them will cost you more than $7-8 if you shop carefully (you may need to be buy several in a lot to get this price).
  
 Happy tube rolling!


----------



## Rossliew

@mordy - I'm using the 6N23P as power tubes now, plugged in without adapters or external heater power supply and it sounds great! Solid bass, wide soundstage and all round musicality. Just not sure if it will kill the amp though..


----------



## mordy

Nuthin' can kill this amp...
  
 The 6N23P draws 0.33A and uses 6.3V so this tube is entirely within the operating specs of the LD MKIII - you have nothing to worry about.
 Just enjoy the music....


----------



## gibosi

rossliew said:


> Oops..i noticed from your earlier replies that the 6N1Ps draw 0.6A and the 5687 tubes draw 0.9A and we need an external PSU to make them work...gasp!
> 
> I just plugged in the 6N1Ps into the socket without any external PSU - will I kill the amp?? But it sounds so good...


 
  
 While driver tube heaters should not exceed 0.45A, power tubes should be fine up to at least 1.0A, So used as powers, 6SN7's and 6N1P's, drawing 0.6A, and 5687's, drawing 0.9A, are perfectly fine.


----------



## hypnos1

rossliew said:


>


 
  
 Hi Rossliew.
  
 If you make sure you set your search options location to "Worldwide" in advanced search, you should find a used PAIR in Italy for about $32, and new ones from Belgium for about $26 each (plus shipping, of course). The only niggle, though, is having to spend more for the adapters than the tubes, lol! - available from happydiy998 (and some people have had problems with quality, but which seem to get resolved OK...). Again, you might need to ensure "Worldwide" search location to find the "C3g to 6AK5 converter/adapter"...or you could search him direct, of course.
  
 But there is no doubt whatsoever that these tubes take our LDs to an amazing level, and are only really equalled by a few that also need the external heater power supply.
  
 Happy rolling!


----------



## gibosi

mordy said:


> After trying the Russian 6N23P tube I dipped into my box of 6DJ8 derivatives. Fished out a rebranded Sylvania 6BC8 tube from Oct 1965 that I had marked as superb sounding. Guess what? With the 6080 power tubes this tube is even better than the 6N23P - more musical and better bass. They are very close though; the 6N23P is brighter with wider sound stage and a little more detail, but as said, not as musical.
> 
> A quick look at Ebay shows many very inexpensive offerings of the 6BC8 tube. You could buy this tube incl shipping for just a few dollars. Highly recommended!


 
  
 The 6BC8 is a variable mu tube. That is, the grid was deliberately designed to be non-linear to handle a wide range of input signal levels without excessive cross-modulation distortion. In theory, given this non-linearity, these should not be suitable for audio. However, in practice, many others in addition to Mordy report that they sound excellent. For those with adjustable heater power supplies, there is also the 4BC8, a 4.2 volt, 0.6A. version. Another variable mu tube that appears to work well for audio is the ECC189/6ES8. And for those with variable heater power supplies, there is also the 5ES8, a 5.6 volt, 0.45A version. Again, these non-standard voltages often result in very cheap prices.


----------



## Rossliew

mordy said:


> Nuthin' can kill this amp...
> 
> The 6N23P draws 0.33A and uses 6.3V so this tube is entirely within the operating specs of the LD MKIII - you have nothing to worry about.
> Just enjoy the music....


 
  
 That's what's so great about the LD! Hmm..A/B-ing the 6N23P and 6922s, the 0.33A current draw is pretty weak which results in a less fulsome sound...but then it still sounds good!
  


gibosi said:


> While driver tube heaters should not exceed 0.45A, power tubes should be fine up to at least 1.0A, So used as powers, 6SN7's and 6N1P's, drawing 0.6A, and 5687's, drawing 0.9A, are perfectly fine.


 
 Thanks for clarification!
  
 Does that mean if there are any tubes which draw 1.0A and lower, it is safe to plug and play as power tubes in the LD 3? (of course some may need adapters). This would mean a pretty wide range of tubes to play around with without the need for external bread boards, PSUs, etc..


----------



## Rossliew

When you guys talk about heater voltage, when used as power tubes, what is the min and max voltage level that is safe for use with the LD3 as plug and play?
  
 For example, Gibosi mentioned the 4BC8 has 4.2V, 0.6A - can i safely use this as a power tube?


----------



## gibosi

rossliew said:


> Does that mean if there are any tubes which draw 1.0A and lower, it is safe to plug and play as power tubes in the LD 3? (of course some may need adapters). This would mean a pretty wide range of tubes to play around with without the need for external bread boards, PSUs, etc..


 
  
 Yes.


----------



## Rossliew

hypnos1 said:


> Hi Rossliew.
> 
> If you make sure you set your search options location to "Worldwide" in advanced search, you should find a used PAIR in Italy for about $32, and new ones from Belgium for about $26 each (plus shipping, of course). The only niggle, though, is having to spend more for the adapters than the tubes, lol! - available from happydiy998 (and some people have had problems with quality, but which seem to get resolved OK...). Again, you might need to ensure "Worldwide" search location to find the "C3g to 6AK5 converter/adapter"...or you could search him direct, of course.
> 
> ...


 
@hypnos1 thanks, dude! I shall seek to find that elusive tube hehehe..


----------



## gibosi

rossliew said:


> When you guys talk about heater voltage, when used as power tubes, what is the min and max voltage level that is safe for use with the LD3 as plug and play?
> 
> For example, Gibosi mentioned the 4BC8 has 4.2V, 0.6A - can i safely use this as a power tube?


 
  
 Without an external heater PS, only 6.3V tubes can be used as power tubes in your LD.


----------



## TrollDragon

mordy said:


> Nuthin' can kill this amp...


 
  
 Now there is a comment I would never make in this thread...


----------



## Rossliew

gibosi said:


> Without an external heater PS, only 6.3V tubes can be used as power tubes in your LD.


 
 Ahh..i get it now, anything less than 6.3V would need external help to heat/power it up. Thanks!


----------



## Rossliew

Guys, can i use a 12AX7 as a power tube with my LD? These are the specifications :
  

Specification and max ratings(*) 
Filament Voltage 6.3-12
VFilament Current 300-150
mAPlate Voltage (_max_) 330
VPlate Current (_max_) 6
mAPlate Dissipation (_max_) 1.1
WScreen Voltage (_max_) ---
VScreen Current (_max_) ---
AScreen Dissipation (_max_) ---
W
 
  
 Looks like it draws about about 0.3A and uses 6.3V or am i reading it wrongly?


----------



## gibosi

rossliew said:


> Guys, can i use a 12AX7 as a power tube with my LD? These are the specifications :
> 
> Looks like it draws about about 0.3A and uses 6.3V or am i reading it wrongly?


 
  
 With an adapter, yes. However, I will be surprised if it sounds good..... too much gain.. not enough current....


----------



## mordy

Hi TD,
  
 The comment about nothing could kill this amp was said in jest. Obviously, if somebody would really want to, you could kill it. What I meant is that with all the various tubes we tried, the amp held up just fine despite some misgivings.
  
 I have been using a pair of 2.5A 6080 tubes as power tubes for many hours without any problems at all. There is a very big spike on my watt meter when they heat up, so I disconnect my speakers with a button until the spike is gone after some 30 seconds.
  
 At this stage my favorite set up is two Sylvania 6080s with the 5687 (Sylvania, Tung Sol or GE) as driver. The bass especially is extremely clear and detailed, and goes very deep. On many recordings I hear details in the deep bass that were not apparent before.


----------



## gibosi

Am I the only one rolling these 9 volt 9AQ8/PCC85?
  
 I received a GT. Britain-made GE today. There are no Philip's codes on the tube, and the construction is very different than my Heerlen-made tube. Comparing it to the Japan-made Sylvania, it is obvious that these were made on identical assembly lines. Perhaps GE is lying? lol


----------



## gibosi

And I also received a Raytheon 6SN7W, and I am happy to report that it lights up and plays. 
  
 Not sure when it was manufactured.  From "2809-38",  280 = Raytheon, so perhaps 9-38 might indicate 1949, week 38?
  
 Note the interesting construction: Little "umbrella spokes" attached to the top mica and cooling fins attached to the cathodes above the top mica.


----------



## Rossliew

mordy said:


> I have been using a pair of 2.5A 6080 tubes as power tubes for many hours without any problems at all. There is a very big spike on my watt meter when they heat up, so I disconnect my speakers with a button until the spike is gone after some 30 seconds.
> 
> At this stage my favorite set up is two Sylvania 6080s with the 5687 (Sylvania, Tung Sol or GE) as driver. The bass especially is extremely clear and detailed, and goes very deep. On many recordings I hear details in the deep bass that were not apparent before.


 
  
 Hi Mordy, did you plug and play the 6080 tubes (perhaps with an adapter only)?


----------



## hypnos1

rossliew said:


> Hi Mordy, did you plug and play the 6080 tubes (perhaps with an adapter only)?


 
  
 Hi R (and mordy).
  
 Please excuse butting in, but...NO, NO, *NO!* - they MUST have a separate heater power supply, lol!


----------



## Rossliew

hypnos1 said:


> Hi R (and mordy).
> 
> Please excuse butting in, but...NO, NO, *NO!* - they MUST have a separate heater power supply, lol!


 
 Oh c#$p! Thought I could have the easy way out..


----------



## mordy

Hi R,
  
 The 6080 draws 2.5A and since the Little Dot amp is limited to 1A you cannot safely use this tube unless you use an external voltage regulator and power supply.
  
 You need an adapter from octal to 9pin. This adapter gets plugged into a 9pin socket extender where the heater pins have been removed and substituted for two wires going to the voltage regulator.
  




 This socket extender comes apart with one screw. The two pins for the heater are de-soldered and removed. A hole has to be drilled in the Bakelite to allow for the wire to leave the socket extender. This dual wire is soldered in at the two pin sockets inside and the wire connected to the voltage regulator, in this case a 15A one. The voltage regulator is powered by a 12V computer power supply in my case.
  




  
 The octal to 9pin adapter is connected to the socket extender (with the two wires going to the voltage regulator). I made a mistake and did not position the hole properly - should have been on the other side of the extender for a neater look.
  




  
 Here are two 6080's connected to two 5A voltage regulators. I have since switched to one 15A voltage regulator for an extra margin of safety.
  




  
 It looks like the one above and does not have a voltage readout so you need an inexpensive multimeter to monitor the voltage.
  
 The whole thing is much less complicated than it sounds and well worth trying.


----------



## Rossliew

mordy said:


> Hi R,
> 
> The 6080 draws 2.5A and since the Little Dot amp is limited to 1A you cannot safely use this tube unless you use an external voltage regulator and power supply.
> 
> ...


 
 Thanks, Mordy for the step-by-step guide. Unfortunately I'm quite a dodo at all these DIY stuff and is bound to mess it up. Unless I can find someone to do it for me, I wouldn't attempt it myself


----------



## hypnos1

I hate to keep rubbing it in guys, but if any of you can manage to stretch to a pair of C3Gs and (somehow!) discover a pair of _reasonably-priced_ GEC 6AS7Gs (or else wait for assessment of the Feliks-Audio project...), I promise you would be in for the surprise of your life.
  
 Just when I thought I could no longer be blown away by this combo, I am currently blasting my eardrums with a remastered "Breakfast in America" by Supertramp, and all the reservations I previously had about this album (or, rather, its less-than-subtle recording quality!) are totally GONE - this set-up is working miracles on this album, and once again I cannot believe my ears, lol!
  
 So dig deep, do a bit of (easy) modding and nirvana is just round the corner 
	

	
	
		
		

		
		
	


	




.


----------



## i luvmusic 2

I need help on finding a pair/s of 6DN7's.Most of the listings at eb4y are singles and pricey so far i found a pair of GE 6DN7 for CAD $16.Thanks!


----------



## MIKELAP

i luvmusic 2 said:


> I need help on finding a pair/s of 6DN7's.Most of the listings at eb4y are singles and pricey so far i found a pair of GE 6DN7 for CAD $16.Thanks!


 
 Bidding starts at $10.00+ $3.25 shipping                                                                                                                                     http://www.ebay.com/itm/Pair-of-Conn-GE-6DN7-tubes-Tested-94-94-92-87-KEI-231-/161423896075?pt=Vintage_Electronics_R2&hash=item25959d2e0b


----------



## MIKELAP

This guy has some he's in Montreal  have to contact him for price and brand               http://www.tubebazar.com/services.html


----------



## i luvmusic 2

mikelap said:


> i luvmusic 2 said:
> 
> 
> > I need help on finding a pair/s of 6DN7's.Most of the listings at eb4y are singles and pricey so far i found a pair of GE 6DN7 for CAD $16.Thanks!
> ...


 
 THANKS! Just don't bid me up LOL.


----------



## MIKELAP

i luvmusic 2 said:


> THANKS! Just don't bid me up LOL.


 
 Oups !


----------



## i luvmusic 2

mikelap said:


> This guy has some he's in Montreal  have to contact him for price and brand               http://www.tubebazar.com/services.html


 
 Preferably not GE i have a pair,Thanks again!


----------



## i luvmusic 2

mikelap said:


> i luvmusic 2 said:
> 
> 
> > THANKS! Just don't bid me up LOL.
> ...


 
 I'am kidding.....Not bidding on it i already have the GE.


----------



## superdux

@hypnos1 thats definatly an album i want to listen to soon! ATM i am rolling some Voskhod 6N23P's and i have the 79 plugged in and just shelved out some more money for 4 more of those beauties(78) which work with an 12AX7 adapter and a 6N23P adapter plugged on top and i also have to say these are some of the best tubes , besides the C3G i have heard yet. We expect prices to soon go rising so grab yourself some aslong as they're hot (and cheap). Their sound is very detailed and i thought there was no more detail to get from my HD650's but i was wrong. This maybe my long lasting rig if i ever win the lottery i'd get something bigger and better. But for entry HiFi this sounds audiophil to me and my 46 year old ears.

some info i found of the different types of Voskhod tubes

http://www.wy7.co.uk/6n23pVarieties.html


----------



## i luvmusic 2

It's kind of a PITA to find a pair of reasonably price 6DN7's.


----------



## hypnos1

superdux said:


> @hypnos1 thats definatly an album i want to listen to soon! ATM i am rolling some Voskhod 6N23P's and i have the 79 plugged in and just shelved out some more money for 4 more of those beauties(78) which work with an 12AX7 adapter and a 6N23P adapter plugged on top and i also have to say these are some of the best tubes , besides the C3G i have heard yet. We expect prices to soon go rising so grab yourself some aslong as they're hot (and cheap). Their sound is very detailed and i thought there was no more detail to get from my HD650's but i was wrong. This maybe my long lasting rig if i ever win the lottery i'd get something bigger and better. But for entry HiFi this sounds audiophil to me and my 46 year old ears.
> 
> some info i found of the different types of Voskhod tubes
> 
> http://www.wy7.co.uk/6n23pVarieties.html


 
  
 Hi superdux.
  
 If you go for a new CD of "BiA", I really suggest you look for the *2010* remaster - there were others - this one is amazing (some of the best deals on ebay seem to be from the UK - about $13, int'l shipped).
  
 Enjoy!


----------



## Johnnysound

Hi to all, returning to this Forum after a  loooong time, I am just a newcomer to "tube rolling" or to tubes in general ( not to audio)  and reading this Forum is for me, basically, an instructive experience.  First, I  must say that I am impressed with the more than 500 pages of posts ¡¡ Congratulations to all,  this is really interesting, we can learn about the  endless possibilities of tube rolling with the LDMKIII, also about tube technology,  rare tubes, and I understand that other tube gear is not so flexible in this aspect.  This indicates to me a very solid, stable and reliable design of the LD amplifier in the first place, with high tolerances, allways a good thing.  
  
As a "rookie" I was inmediately impressed  with the improvement  in sound just by swapping the stock GE tubes with some NOS Voshkod ones, recommended in this forum.  Big difference indeed,  now the sound was more clearly defined,  with superior bass and extended highs.  So modified,  I tested the LD as a preamp (thru mono ss amps) into my very efficient 93 Db speakers, and it sounded simply beautiful, no less.  I do have two very nice preamps,  one is an ss active and the other an esoteric TVC passive, both much more costly but....this little tubed HP amp simply sounded MUCH better,  blow them away in musicality, naturalness, tonality, I dont know how to describe it.  I must confess that I was not really interested in an HP amp, in fact, I discovered the LD  in this very forum,  read so many positive comments, and found in the LD page that  it was designed from the outset as a full preamp, in paralell with  its headphone out,  Now this was interesting, if the LD was capable of such quality with high definition headphones, then It must make an outstanding preamp as well.  I was right, and I do not care if nobody praises the LDIII as a preamp,  This is why this hobby is so nice.                 
  
So far so good, but... after some hours I detected a kind of background "tension",  more than noise, something that was not totally right .  Again, this forum had the right answers, and many thanks to Gibosi and Hypnos1 for their advice about "elemental" tube rolling with the LDMKIII, in short, going from EF95 to EF92 tubes is much more significant in sound quality, and the NOS Tung Sols 6485 recommended made a great difference.  First, much lower noise floor, a more open, relaxed sound, (probably a result of being a "quieter" tube) and very linear performance from top to bottom.  Very good, and I do not feel the need to rolling anything after this ¡¡ It must be a better tube, more stable, I do not know the technical details,  Finally, I must say that I am totally LOST with the latest posts, swapping power tubes with adaptors, external power supplies, are beyond the uninitiated.  Perhaps somewhere is a kind of basic guide or something about power tubes...
  
Thanks everybody,


----------



## hypnos1

johnnysound said:


> Hi to all, returning to this Forum after a  loooong time, I am just a newcomer to "tube rolling" or to tubes in general ( not to audio)  and reading this Forum is for me, basically, an instructive experience.  First, I  must say that I am impressed with the more than 500 pages of posts ¡¡ Congratulations to all,  this is really interesting, we can learn about the  endless possibilities of tube rolling with the LDMKIII, also about tube technology,  rare tubes, and I understand that other tube gear is not so flexible in this aspect.  This indicates to me a very solid, stable and reliable design of the LD amplifier in the first place, with high tolerances, allways a good thing.
> 
> As a "rookie" I was inmediately impressed  with the improvement  in sound just by swapping the stock GE tubes with some NOS Voshkod ones, recommended in this forum.  Big difference indeed,  now the sound was more clearly defined,  with superior bass and extended highs.  So modified,  I tested the LD as a preamp (thru mono ss amps) into my very efficient 93 Db speakers, and it sounded simply beautiful, no less.  I do have two very nice preamps,  one is an ss active and the other an esoteric TVC passive, both much more costly but....this little tubed HP amp simply sounded MUCH better,  blow them away in musicality, naturalness, tonality, I dont know how to describe it.  I must confess that I was not really interested in an HP amp, in fact, I discovered the LD  in this very forum,  read so many positive comments, and found in the LD page that  it was designed from the outset as a full preamp, in paralell with  its headphone out,  Now this was interesting, if the LD was capable of such quality with high definition headphones, then It must make an outstanding preamp as well.  I was right, and I do not care if nobody praises the LDIII as a preamp,  This is why this hobby is so nice.
> 
> ...


 
  
 Welcome back J...and boy, do you have some catching up to do, lol!
  
 The general concensus is that the best straight plug 'n play driver is the TALL-bottle 6HM5 (EF95 setting) - and a very good deal is from ebayer 'tachonz' in Serbia...I always found he accepted an offer of $5 a tube, with FREE shipping! You can't ask for more really, can you?
  
 As for powers, the easiest mod has to be using 6SN7s with commercially available adapters...there's all the info you need in recent posts (a fair bit of reading still needed though, as you have found out!).
  
 You will find you can take the humble LD to even greater heights!


----------



## gibosi

More tubes....
  
 A 1966 Nevz 6N1P-E arrived today. It is the tube on the right. And to the left is a 1968 Novosibirsk 6N5P. The resemblance is quite remarkable I think.
  

  
 And I have been wanting to try an RCA 5687 and finally found one cheap. The RCA has these very distinctive support rods that come up through the top mica and then are bent over.  
  

  
 Have a full schedule today so have yet to even check to see if they light up and play... ;(


----------



## Johnnysound

hypnos1 said:


> Welcome back J...and boy, do you have some catching up to do, lol!
> 
> The general concensus is that the best straight plug 'n play driver is the TALL-bottle 6HM5 (EF95 setting) - and a very good deal is from ebayer 'tachonz' in Serbia...I always found he accepted an offer of $5 a tube, with FREE shipping! You can't ask for more really, can you?
> 
> ...


 
 Yes, you are right, 500 pages are a LOT of posts to read.  Is good to know about the 6HM5 tube, will try it, found the ebayer you mentioned, there are two or three more in Serbia selling the same tubes,  look like very good quality.  There is an offer for four at $24.50 free shipping, in my short experience with NOS tubes, is better to be on the safe side and have some spares ¡¡ I bought the NOS Tung-Sol 6485 in a pack of 5, wise decision,  one tube went dead after about 20 hs. and I have a spare to .replace it.     Also, found a pair of EC900 (equivalent 6HM5) Miniwatt Philips, very highly regarded brand, as it seems,,,what do you think, it is compatible ? any experiences with this one ?  About the power tubes, the original russians look quite good, what is the difference in sound with a pair of 6SN7 with adapters?


----------



## gibosi

johnnysound said:


> Also, found a pair of EC900 (equivalent 6HM5) Miniwatt Philips, very highly regarded brand, as it seems,,,what do you think, it is compatible ? any experiences with this one ? About the power tubes, the original russians look quite good, what is the difference in sound with a pair of 6SN7 with adapters?


 
  
 In general, the short squat EC900/6HM5 do not sound as good as the tall bottles. So if the Philips tubes are tall, they will probably be very good.
  
 You may have noticed on eBay there are about 3000 listings for 6SN7 tubes. These tubes were manufactured from the early 1940's through the 1970's and even beyond, by American, European. Japanese and Russian manufacturers. With so many different tubes, and so many sonic signatures, it is hard to describe the 6SN7 "sound." My suggestion is buy some cheap ones and see what you think. Also, I suggest a pair of 5687 with adapters for powers. There are fewer options, only American brands, but in my experience they are all very good.


----------



## Johnnysound

gibosi said:


> In general, the short squat EC900/6HM5 do not sound as good as the tall bottles. So if the Philips tubes are tall, they will probably be very good.
> 
> You may have noticed on eBay there are about 3000 listings for 6SN7 tubes. These tubes were manufactured from the early 1940's through the 1970's and even beyond, by American, European. Japanese and Russian manufacturers. With so many different tubes, and so many sonic signatures, it is hard to describe the 6SN7 "sound." My suggestion is buy some cheap ones and see what you think. Also, I suggest a pair of 5687 with adapters for powers. There are fewer options, only American brands, but in my experience they are all very good.


 
 The seller puts only a fuzzy picture of the box, not the tubes,  *EC900   PHILIPS   (2) NIB/NOS  (6HA5 / 6HM5)* but are original ones, maybe I should ask about it. Look like tall bottles,
 My doubt about the power tubes is very general, I wonder what are the advantages in sound quality with the 6SN7 tubes, and I mean ANY good  6SN7 with adapters,  over the stock russian 6H6PI ? 
 I am sure there are many posts about this...I suppose you get better bass and dynamics.


----------



## mordy

Can the 6DN7 tube be used in the LD MKIII? Power tubes or driver? Does it have any advantage over a 6SN7/6AS7/6080?


----------



## TrollDragon

mordy said:


> Can the 6DN7 tube be used in the LD MKIII? Power tubes or driver? Does it have any advantage over a 6SN7/6AS7/6080?


 

 Not well as it is a Dissimiliar Dual Triode.


----------



## mordy

Hi Johnnysound,
  
 All the questions you asked have answers on this forum - suggest reading from the most recent posts and work backwards in time. There are illustrated tutorials how to make. and/or connect adapters and what kind of stuff you need etc etc.
  
 For a long time we experimented with different versions of the Russian 6N6P power tubes and found versions much better than stock. There are certain tubes that have been hyped up by various sellers. One such tube is the 6H30-DR "super tube". It's nice, but it commends a very high price today.
  
 Now, a garden variety 6SN7 tube (needing adapters to be used) sounds much better than even the best 6N6P family of tubes. The 6H30-DR sounds thin in comparison.
  
 The next step up in power tubes are the octal 6AS7/6080 tubes. These draw 2.5A and need , in addition to the adapters, an external power supply with a voltage regulator. The difference between these tubes compared to the 6SN7 is like the difference between grape juice and a fine wine. The best of these 2.5A octals add more layers of detail and more punch in the bass and sizzle in the treble - the difference is startling.
  
 Some of these tubes are very pricey, but other unsung heroes can be bought for a few dollars. In general, the 6AS7 fetch higher prices, perhaps because esthetically the coke bottle shape looks nicer.
  
 Then we have the dual triodes for use as driver tubes.....
  
 PS: Re the Tung Sol tube that died on you - did it turn white inside or did the glass crack? If not, it probably is still working, but the pins may have oxidized. You can take a small knife blade or similar and gently scrape the pins to remove the grime and oxidation accumulated over decades. I got several tubes working after trying this, including a Tung Sol tube.


----------



## mordy

Hi TD,
  
 Does this mean that each half of the dual triode has a different function?


----------



## TrollDragon

mordy said:


> Hi TD,
> 
> Does this mean that each half of the dual triode has a different function?


 
  
 Hi mordy,
 Basically like two different tubes in one, they were built for TV vertical oscillation / deflection circuitry.
  
 Quote: NJ7P SQL Tube Database 





> *Triode 1 Class A Amplifier*
> Plate Voltage ................................. 250 V
> Grid No. 1 Voltage ............................ -8 V
> Amplification Factor .......................... 22.5
> ...


----------



## gibosi

johnnysound said:


> My doubt about the power tubes is very general, I wonder what are the advantages in sound quality with the 6SN7 tubes, and I mean ANY good  6SN7 with adapters,  over the stock russian 6H6PI ?
> I am sure there are many posts about this...I suppose you get better bass and dynamics.


 
  
 If you go back through this thread, most, if not all, who have tried 6SN7's as power tubes, prefer them over the traditional 6N6P/6N30P-type tubes. As to the details and specifics, you will need to read their postings.
  
 Since I have an LD 1+, which uses an op amp, rather than power tubes, I simply can't say....
  
 Cheers


----------



## Johnnysound

gibosi said:


> If you go back through this thread, most, if not all, who have tried 6SN7's as power tubes, prefer them over the traditional 6N6P/6N30P-type tubes. As to the details and specifics, you will need to read their postings.
> 
> Since I have an LD 1+, which uses an op amp, rather than power tubes, I simply can't say....
> 
> Cheers


 
 Thanks gibosi, I am doing precisely that... reading earlier postings, and so far,  in page 201 (post 3007) found an excellent review by Acapella11 about that family of power tubes, and he liked very much  the 6N6PI-R,  an improved version of the stock tubes.  I am yet to arrive at the page where the mighty 6SN7 with adapters won the competition...


----------



## i luvmusic 2

Speaking of 6DN7's i found  10 6DN7(2 RCA,1 Marconi,3 Sylvania and 4 GE)$62 including shipping.Since the two sections are dissimilar matching pair is not important? and don't worry these tubes are not going on the LD,maybe


----------



## gibosi

mordy said:


> Does this mean that each half of the dual triode has a different function?


 
  
 It is my understanding that in the amps that use the 6DN7, one half is used as a driver and the other half is used as a power. It would require fairly complex adapters to use these in an LD, but  of course, it could be done.


----------



## hypnos1

johnnysound said:


> Thanks gibosi, I am doing precisely that... reading earlier postings, and so far,  in page 201 (post 3007) found an excellent review by Acapella11 about that family of power tubes, and he liked very much  the 6N6PI-R,  an improved version of the stock tubes.  I am yet to arrive at the page where the mighty 6SN7 with adapters won the competition...


 
  
 Hi again J.
  
 Glad to see the guys have given you all the advice you need - no wonder this thread beats all comers, lol! 
	

	
	
		
		

		
		
	


	




.
  
 In the end, it all comes down to how full the wallet is (or the credit card empty!) and how much tinkering you feel up to 
	

	
	
		
		

		
		
	


	




..
  
 If funds permit, and you don't want the DIY stuff, you will not get better than a pair of C3g drivers (with adapters) and your choice of 6SN7 (again with adapters). BUT, as mordy says, if you can manage the power tube mods for the 6AS7G/6080, the leap is quite dramatic...unbelievable, in fact!
  
 GOOD LUCK!   
	

	
	
		
		

		
		
	


	




 
  
 EDIT..ps. _When(?!)_ you manage to digest all you need in this thread, if you go ahead with the 6SN7 there's PLENTY(!!) more on these tubes over at the "6SN7 Tube Addicts" thread and "The Reference 6SN7 thread (guide)"...You're gonna need plenty of midnight oil, methinks...


----------



## Johnnysound

Many thanks mordi, gibosi and hypnos1  for your  advice,  it will be fun to try the mods ¡¡
  
  BTW, mordi  the Tung-Sol 6485 just died, and the tube looks 100% perfect, so you are probably right about the pins...


----------



## gibosi

Has anyone who has installed an external heater PS circuit to run 6AS7's tried the 6BL7 and/or 6BX7 as power tubes in their LD? (While these draw only 1.5A compared to 2.5A for the 6AS7, an external PS is still required.) Internally, these draw considerably less plate current than the 6AS7, and therefore, should be less stressful on circuit board resisters. And further, I have read a number of reports claiming that these sound better than the 6AS7 when used as power tubes. The only real drawback compared to a 6AS7 is they can't drive low-Z cans as well. Even so, they can drive low-Z cans better than 6SN7's.


----------



## Johnnysound

hypnos1 said:


> Hi again J.
> 
> Glad to see the guys have given you all the advice you need - no wonder this thread beats all comers, lol!
> 
> ...


 
 Any suggestion for the 6SN7 adapters ? (octal to 9-pin I understand)


----------



## gibosi

You want something like this:
  
 http://www.ebay.com/itm/1pc-6SN7-6H8C-6N8P-CV1988-B65-VT231-TO-6CG7-6FQ7-tube-adapter-for-you-amp-6-3V-/201083492877?
  
 With 6SN7 on top and 6CG7 on the bottom.


----------



## mordy

Hi Gibosi,
  
 I did try the 6BX7 and 6BL7 as _driver_ tubes, and they are quite good, with my preference going to the 6BX7 tube. I cannot remember clearly, but I think I tried them as power tubes and found the 6SN7/12SN7 sounding better as power tubes. I would have to revisit using the 6BX7/6BL7 to confirm it.


----------



## superdux

thx gibosi for the link. I really had quit on spending more on tubes.....but now i have to try the 6SN7 just for fun.Guess i'm broke already next month. Are there similar iterations i can look for, because these tubes seem quite expensive to me after doing a search.
 anyway found an interesting chart on FB.Here ya go


----------



## gibosi

superdux said:


> thx gibosi for the link. I really had quit on spending more on tubes.....but now i have to try the 6SN7 just for fun.Guess i'm broke already next month. Are there similar iterations i can look for, because these tubes seem quite expensive to me after doing a search.


 
  
 Without using an external heater PS for power tubes, other than the Russian 6N6P/6N30P-type tubes, the only others I am aware of are 6SN7's and 5687 (and related 7044/7119/E182CC). 
  
 And yes, so-called "pairs" of 6SN7 can be expensive. However, I suggest buying a bunch of cheap ones. For example, this listing.
  
 http://www.ebay.com/itm/Mixed-Lot-16-RCA-6SN7-Type-Tubes-Tested-/390932102670?
  
 You often see lots of 8, 10, 20 tubes, often all one brand, and they usually sell cheap. Once you get them, select two tubes that look the same and plug them in. This is an inexpensive way to learn what you like and don't like.
  
 Cheers


----------



## Johnnysound

gibosi said:


> You want something like this:
> 
> http://www.ebay.com/itm/1pc-6SN7-6H8C-6N8P-CV1988-B65-VT231-TO-6CG7-6FQ7-tube-adapter-for-you-amp-6-3V-/201083492877?
> 
> With 6SN7 on top and 6CG7 on the bottom.


 
  
 Thank you again gibosi,  and sorry about my ignorance, this means this adapter (6SN7 on top) goes directly into my 9-pin power tube socket ?
  
 Also, if I want to use the very nice C3g as driver tube, (as suggested), I would need another adapter.. this one octal to 7-pin, need help to find it...maybe the same ebayer has it. 
 You know, for us newcomers,  so many tube codes can be a bit...CONFUSING (lol)


----------



## superdux

may i answer your C3G question:

socket savers(test tube)

http://leedsradio.com/parts-sockets.html#savers


Test socket 7 pin miniature $8.00

C3G adapter

http://www.ebay.com/itm/301131714830?ssPageName=STRK%3AMEWNX%3AIT&_trksid=p3984.m1497.l2649

you only need the socket saver if you have a MKIII and don't touch when the amp is running, they are test sockets and have wires sticking out.


----------



## gibosi

johnnysound said:


> Thank you again gibosi,  and sorry about my ignorance, this means this adapter (6SN7 on top) goes directly into my 9-pin power tube socket ?
> 
> Also, if I want to use the very nice C3g as driver tube, (as suggested), I would need another adapter.. this one octal to 7-pin, need help to find it...maybe the same ebayer has it.
> You know, for us newcomers,  so many tube codes can be a bit...CONFUSING (lol)


 
  
 Yes, you plug your 6SN7 into the adapter, and then you plug the other end of the adapter into your power tube socket. So here is a pic of a nice Raytheon 6SN7W plugged into the adapter.
  

  
 And Superdux has provided you with links to use a pair of C3g's. Since it is likely that your LD III has those gold rings around the socket, they are too narrow and do not allow the adapter to be plugged in, so you need the socket saver, which functions as a socket extender.
  
 Here you go with pictures:
  
 http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/6000#post_10512665


----------



## superdux

here is a link to socket savers for your 6SN7 adapters.

http://www.ebay.de/itm/160622385954?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649

Thx to rossliew who provided me the links


----------



## Johnnysound

Many thanks superdux, now it is clear for me:  the 7-pin socket needs an extender (socket saver), plus an adapter for the C3g tube.  BTW, the adapter is VERY expensive at $29.50 each plus shipping (¡¡)
 On the other hand, I assume that (hopefully) the 6SN7 adapter goes directly into the 9-pin socket,


----------



## superdux

Hi johnny, i just posted a link to some socket savers for your 6SN7 adapter, see post above
You just need them, if you have the MKIII and the gold rings around the socket.


----------



## Johnnysound

gibosi said:


> Yes, you plug your 6SN7 into the adapter, and then you plug the other end of the adapter into your power tube socket. So here is a pic of a nice Raytheon 6SN7W plugged into the adapter.
> 
> 
> 
> ...


 
  
 Excellent  ¡¡  Just saw this matched pair of old Raytheon 6SN7GTB, black flat plate top O Get, tested 80/82 (is this good?) Coded: G24 and I24, I assume compatible, again, different designation than your 6SN7W which look much more "vintage":
  
  
  

  
  
  
    
As you said in your earlier and very informative post, the investment with the C3g is considerable at around $ 140-$150 with adapters, but if it sounds so glorious, is worth the price of admission...I see tube stores charge even more for single tubes ¡¡


----------



## gibosi

johnnysound said:


> Excellent  ¡¡  Just saw this matched pair of old Raytheon 6SN7GTB, black flat plate top O Get, tested 80/82 (is this good?) Coded: G24 and I24, I assume compatible, again, different designation than your 6SN7W which look much more "vintage":


 
  
  
  
 Actually, after further investigation, I have concluded that my 6SN7W was manufactured in 1959, so not as old as I thought.... Nonetheless, it is a terrific tube. And if you can get the Raytheon GTB's cheap, then yes, these would be great tubes to start your journey into 6SN7 land


----------



## Johnnysound

superdux said:


> Hi johnny, i just posted a link to some socket savers for your 6SN7 adapter, see post above
> You just need them, if you have the MKIII and the gold rings around the socket.


 
 Thank you Superdux ¡¡   Yes, when I saw the 6SN7 adapter pic, it looked too wide for the MKIII...
 In short: both the 6SN7 and the C3g need socket extenders and adapters...from 4 different suppliers ¡¡


----------



## Johnnysound

Got this matched quad "lightly used" ITT 6SN7GTB (Japan) for  39.95 plus shipping.  Looks like a good deal, seen the same quartet elsewhere for $100 or more ¡.   In the "6SN7 Addicts" thread they love this one, and say is the same tube as the famed Hitachi 6SN7GTB,   with a very interesting history: ITT bought Western Electric many years ago,  an then owned STC-Brimar  in the UK  from 1925 till 1982.   I concluded that ITT  must  know something about tubes. The "Addicts" say that these japanese tubes are very well made, and sonically among the "top three" favorites for some...we'll see.   Besides, better have some spares, just in case...


----------



## superdux

if there's any ending at the name of the 6SN7 like "GTB" or "W" or somethin similar doeas that have to bother me, if i want to roll the tubes as power tubes in my LDMKIII?


----------



## gibosi

superdux said:


> if there's any ending at the name of the 6SN7 like "GTB" or "W" or somethin similar doeas that have to bother me, if i want to roll the tubes as power tubes in my LDMKIII?


 
  
 No.
  
 The "W" just indicates that the tube was ruggedized for military and industrial uses. Since the 6SN7GT was used in television circuits, 6SN7GTA tubes were introduced to handle the increased voltage and power requirements of larger screen sizes. And again, the 6SN7GTB was introduced to provide a controlled warm-up time necessary for stringing multiple tubes together. As far as your LD is concerned none of these "enhancements" make a difference.


----------



## superdux

thx gibozi, you tube wizard, lol


----------



## hypnos1

Hi everyone....
  
 A salutary lesson in how easy it is to be misled when assessing tubes :
  
 Despite being an avid follower of (and erstwhile contributor to) this thread and having rolled many dozens of tubes (though nowhere near as many as some, lol!), I made a basic error in my latest test - viz. having been ordered (...no, _encouraged_! 
	

	
	
		
		

		
			





) by mordy to do a shoot-out between my beloved C3GSs and some 5687s, I dutifully obliged and set to with my Raytheons - which had good reviews -  and being used, I assumed wouldn't need extended burn-in...they also came with very good test readings...
  
 Anyway, to cut a long story short, they sounded terrible - not because of any fault in the tubes as such, but in every respect they were trounced by the C3gs. My mistake?...to assume the 5687 was nowhere near the C3g...silly me!
  
 Luckily, I had also managed to snag a pair of '50s Tung Sols, so before writing off this tube family completely I popped them in just out of curiosity, and...WOW, the difference was unbelievable. How two tubes of the same family could sound so different took me rather by surprise - to say the least! I don't think I have ever come across such disparity in all the tubes I have tried in this past year (plus).
  
 In short, even without much testing as yet, they are going to be VERY stiff competition for the C3gs. First impressions are that they give a slightly more forward and "fuller" sound - the bass hits a bit harder, especially - but perhaps at the expense of some "airiness" and holographic imagery (I have a feeling that there is always going to be a certain trade-off between these two "signatures", and that one has to choose which type is preferred*...unless an amp, or tube combination, turns up that can achieve miracles and marry the two successfully - a seemingly impossible task, perhaps?!).
  
 And so, mes amis, the moral is try as many different flavours of a tube as you can _before_ coming to a conclusion....which, of course, is what you all do already, no?!  
	

	
	
		
		

		
		
	


	



  
 ps. It would appear, perhaps, that several reviews I have glimpsed are correct when they praise the virtues of the very early Tung Sol 5687s in particular...
  
 Edit...*ps. Mind you, we rollers don't really have too much of a problem with this dilemma - we can just pop in the tubes we want depending on the mood, lol!...eg. C3g when we want to float dreamily through the heavens, and 5687 when we want to be "in the thick of the action", lol! (Or something along those lines 
	

	
	
		
		

		
		
	


	




..).


----------



## i luvmusic 2

Anyone have tried these type of RCA tubes,are they better than clear glass?
  
 THANKS!


----------



## gibosi

hypnos1 said:


> Luckily, I had also managed to snag a pair of '50s Tung Sols, so before writing off this tube family completely I popped them in just out of curiosity, and...WOW, the difference was unbelievable. How two tubes of the same family could sound so different took me rather by surprise - to say the least! I don't think I have ever come across such disparity in all the tubes I have tried in this past year (plus).
> 
> In short, even without much testing as yet, they are going to be VERY stiff competition for the C3gs. First impressions are that they give a slightly more forward and "fuller" sound - the bass hits a bit harder, especially - but perhaps at the expense of some "airiness" and holographic imagery (I have a feeling that there is always going to be a certain trade-off between these two "signatures", and that one has to choose which type is preferred...unless an amp, or tube combination, turns up that can achieve miracles and marry the two successfully - a seemingly impossible task, perhaps?!).
> 
> ...


 
  
 There are early 1950's Tung sols and mid-to-late 1950's Tung-Sols. The ones that people seem to think are the best are the early 1950's. These tubes have flat, thin ribbed plates, quite different than the plates on the mid-1950's and later, and are often quite expensive:
  
 http://www.ebay.com/itm/Matched-Pair-TUNG-SOL-JTL-5687-Black-Ribbed-Plates-D-Getter-E182CC-TUBES-/131293016241?
  
 I don't have one of these so I can't say just how good they are. Mine is a 1956 tube, and while it is very good, it does not have the older plates.
  
 The Sylvania 5687WA is my favorite 5687, so far, and recently, I have been listening to an RCA which sounds very good too. It has a bit more warmth, typical of RCA's, but all and all, it is very nicely balanced to my ears. So yes indeed, I suggest you try a couple more flavors.


----------



## gibosi

i luvmusic 2 said:


> Anyone have tried these type of RCA tubes,are they better than clear glass?


 
  
 The differences people talk about regarding RCA's are related to the year of manufacture, and not smoked glass or clear glass. And as you might guess, people say the earlier the better. So while 1940's production might be a bit better, these should still be terrific.


----------



## i luvmusic 2

gibosi said:


> i luvmusic 2 said:
> 
> 
> > Anyone have tried these type of RCA tubes,are they better than clear glass?
> ...


 
 THANK YOU!I think i'am getting addicted to 12SN7's they are cheaper than 6SN7's.
 BTW i started using 6/12SN7's on the CRACK and i love them now, back then i really did not give them enough time to familiarize the sound of these tubes compared to 12AU7's i now know the difference between the two types of tubes(on CRACK).The 6/12SN7's have wider soundstage and more details than the 12AU7 but for the bass i prefer the 12AU7's bass for the CRACK.


----------



## TheClarifier

I could never thank Dept_Of_Alchemy enough for this guide (THANK YOU!!)! These posts and this guide got me to take the plunge with an MKll and I could not have been happier with it so far. I have some Voshkod 6ZH1P-EV drivers and some Russian 6H6P-1 power tubes that will be going into it tonight thanks to everyone's feedback. Once I got about 5 albums on the stock tubes they really started to come alive and I was already enjoying them. So if the stock tubes were going to get even better in time then I can't imagine what these new tubes will sound like down the road.   A question for the group... not that they would be necessary per se but I have seen pictures where people have small heat sinks that attach directly to the tube. One image I saw it was like a metal wire that clung to the tube halfway down and it had some small donut-like heat sinks looped in it that were resting against the tube surface. Are these helpful? Anyone know what they are officially called? I Googled for at least 30 minutes with absolutely zero hits. I wish I could find the pic again. There is a possibility this was part of a specific set of tubes and not an accessory. 
  
 Edit: Found the pic! Halfway down this forum page. http://www.head-fi.org/t/364043/little-dot-i-tube-rolling/420    Thanks in advance for any info you can provide!


----------



## mordy

Hi TC,
  
 I believe that these gizmos are called tube dampers. Here is a link:
  
 http://herbiesaudiolab.net/tube.htm
  
 (Seems that what you have on the picture you saw is the Guitar Amp Ultrasonic damper)
  
 I think that the intention of these dampers is to get rid of vibrations and microphonics. Some people use silicon rings on the tube. Just type in tube dampers on Ebay and you will get hundreds of orange silicone rings for sale. (A plumbing supply may have these items for significantly less)
  
 Whether they work or not seems to be debatable - anybody wants to weigh in?
  
 Here is some Turkish Delight tube candy:
  
 http://www.ebay.com/itm/2-x-VACUUM-TUBE-AMP-DAMPER-RING-12AX7-6DJ8-EL84-6H30P-Improves-Sound-/161388790693?pt=Vintage_Electronics_R2&hash=item25938583a5


----------



## Oskari

mordy said:


> Whether they work or not seems to be debatable - anybody wants to weigh in?


 
  
 They add some weight. That just might help if you're lucky. Don't count on miracles.


----------



## TrollDragon

Nice tube jewelry...


----------



## mab1376

mordy said:


> Hi TC,
> 
> I believe that these gizmos are called tube dampers. Here is a link:
> 
> ...


 
  
 My c3gs tubes ring audibly if I tap the glass. If i hold the tip of my finger on the glass the ringing stops (it stops on it's own pretty quickly anyway). I don't notice any ring if I tap the desk it's on instead. 
  
 The 6SN7's on the other hand, can be tapped to the beat of a song and I don't notice a thing.
  
 My 2 cents would be they're good if you're gonna spend less than $10 on the pair, any more than that and you're may as well be buying jewelry.


----------



## TheClarifier

Thanks Morty, Mab1376 et all!
 I'll wait to see if anyone else chimes in before heading over to Howies. In my mind if they even help a little and add to the aesthetics I am probably in. Going to try doing some light tapping tonight as Mab1376 mentioned.


----------



## Oskari

Do remember that all tubes are microphonic to some degree. Generally speaking, one should avoid tapping one's tubes.


----------



## TrollDragon

While you are picking out some jewelry for your tubes, you should get them some anti-vibration sockets as well...
  

  
 Ya need a nice pair of shoes to go with those earrings...


----------



## Oskari

Shoes… or galoshes.


----------



## TheClarifier

Thank you Oskari...good heads up on the tapping. And thank you TrollDragon for the heads up on the footwear which I now see as a must have. I will certainly be further blinging (really there isn't a better word than that?) my MKll out. 
  
 So I got the Voshkod 6ZH1P-EV drivers and Russian 6H6P-1 power tubes in tonight. On album 2 and I can already tell what I am in for. If anyone is reading this and you haven't ordered your LD amp you are just wasting time. An incredible value and worth investing those savings in some killer tubes. 
  
 Brick the doorway I will be sitting right here in my listening chair.


----------



## mab1376

oskari said:


> Do remember that all tubes are microphonic to some degree. Generally speaking, one should avoid tapping one's tubes.


 
 sorry i should've mentioned it, more of an observation.


----------



## hypnos1

Further observations on 5687 v C3g...given _my_ gear and ears, of course!
  
 As the Tung Sols were also used tubes, I think I now have enough time on them to get a good idea of what they do...
  
 Although they are far better than the Raytheons (mine, at least), I think I am getting  - coupled with others' findings - a fair impression of the 'house' sound, and it looks like a definite emphasis on the bass and lower mid-range frequencies. This gives a really nice 'lush' sound, and fair blows the mind (if not the head _off_!) with music where this part of the spectrum dominates - like 'The Battle' on the soundtrack to Gladiator...VERY exciting...
  
 However, this is at the expense of some of the higher frequencies - they are there, but are somewhat overpowered by the lower ones, most noticeable when the upper strings come in, on this particular track.
  
 This tendency I also found with music combining acoustic, electronic and vocals...a nice rich, 'full' sound on the whole, but again the more subtle tonal ranges of the upper mids and treble, eg. strummed strings, treble woodwind/percussion, female voice etc. weren't resolved to quite the same degree as managed by the C3g. Coupled with the slightly less note decay (especially in the treble), this aspect - of my 5687s - results in not quite the same degree of 3D, holographic spatial rendition (as I have mentioned previously). The C3gs also seem better able to position different elements of a REALLY good recording engineer's mastery of "surround sound" - front/back; top/bottom; left/right - in fact, sometimes I could swear there's a FOURTH dimension going on in my head, lol!
  
 Once again, these differences are only very subtle ones, and so much is going to depend on the rest of the set-up in question of course. My own findings are through HD650s (with pure silver cable, and said silver wherever I can manage to fit it! - right down to my own-made adapters) connected direct to the amp; mains power conditioner etc. etc.
  
  
 Anyway, these are just my own observations - but I feel there must be a modicum of truth somewhere in how I find the C3g ...viz a question recently put to maestro Glenn (of Glenn amps, of course), ie. when asked if he had an amp "to rule them all", Glenn's reply was..."C3g > 300B with Lundahl transformer...  rules everything". I cannot imagine a better vindication of the qualities of the C3g, lol!..
	

	
	
		
		

		
		
	


	



  
 ps. Mind you, these 5687s sure are mighty tubes...and a lot cheaper - IF you are prepared to do some modding, that is!


----------



## gibosi

hypnos1 said:


> Further observations on 5687 v C3g...given _my_ gear and ears, of course!
> 
> Although they are far better than the Raytheons (mine, at least), I think I am getting  - coupled with others' findings - a fair impression of the 'house' sound, and it looks like a definite emphasis on the bass and lower mid-range frequencies. This gives a really nice 'lush' sound, and fair blows the mind (if not the head _off_!) with music where this part of the spectrum dominates - like 'The Battle' on the soundtrack to Gladiator...VERY exciting...
> 
> ...


 
  
 A question and a few comments:
  
 Do you have the oldest Tung-Sol, the one with flat, ribbed plates? Or are yours the later ones, with flanged square box plates?
  
 Your observations regarding the TS-5687 match those of others, that is, less tonal decay and detail in the upper mids and treble. Those that really like this tube tend to use brigher headphones, such as Grado and Beyers. From this, I suspect that HD650's might be a bit too dark to match up well with this tube. Moreover, it is a matter of personal taste, as well. My HD700's are pretty bright, but even so, I still prefer the Sylvania.
  
 And very frankly, it is the 300B tube with transformers that makes Glenn's amp the "one to rule them all". This amp can drive speakers, as well as low-Z and high-Z cans. So it truly is an "all in one" amp. While it is a given that the C3g is an extraordinary tube, what makes it special in this case is a gain of 40. The 300B requires a driver with lots of gain. A 6SN7, with a gain of only 20, simply cannot drive the 300B nearly as well. To date, Glenn has yet to build a 6AS7-based OTL with C3g's. I fully expect that he will someday, but for now, we do not know how this combination might stack up against a C3g+300B for headphone use.
  
 All that said, the C3g is a GREAT tube!


----------



## hypnos1

gibosi said:


> A question and a few comments:
> 
> Do you have the oldest Tung-Sol, the one with flat, ribbed plates? Or are yours the later ones, with flanged square box plates?
> 
> ...


 
  
 Hi g.
  
 My TSs do have narrow 'boxes' (17mm black plates), so I presume are not the earliest - unfortunately.
  
 So, do you think the Sylvanias answer ALL of my reservations? - not just re decay and detail, but the C3g's uncanny abilities concerning 3-dimensional placement?...Very tall order, methinks!  
	

	
	
		
		

		
		
	


	




...shall have to look out for a 'mordy' deal, lol!!
  
 Interesting point re the 300B requiring the higher gain...my GEC 6AS7Gs need the volume control turned up a good deal higher with the 5687s in situ...


----------



## i luvmusic 2

trolldragon said:


> While you are picking out some jewelry for your tubes, you should get them some anti-vibration sockets as well...
> 
> 
> 
> Ya need a nice pair of shoes to go with those earrings...


 
 Don't forget to CRYO them.


----------



## Johnnysound

mordy said:


> Hi TD,
> 
> The comment about nothing could kill this amp was said in jest. Obviously, if somebody would really want to, you could kill it. What I meant is that with all the various tubes we tried, the amp held up just fine despite some misgivings.
> 
> ...


 
 Hi Mordy, found a pair of NOS Sylvania 5687WB, (look like sixties stock) at a fair price, but these are 9-pin tubes, what adapter you use into the 7-pin driver socket ?  Thanks for your help.


----------



## gibosi

johnnysound said:


> Hi Mordy, found a pair of NOS Sylvania 5687WB, (look like sixties stock) at a fair price, but these are 9-pin tubes, what adapter you use into the 7-pin driver socket ?  Thanks for your help.


 
  
 If you wish to use the 5687 as power tubes, then get a pair of these adapters, and you are good to go:
  
 http://www.ebay.com/itm/290977041297?
  
 If you wish to use the 5687 (as well as other double triodes) as a driver, then the "adapter" is a bit more complicated....
  
 http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/5760#post_10435226
  
 And you will have something like this:


----------



## JazzVinyl

Questions regarding use of the C3g on Little Dot amps...

Does the C3g work on the Little Dot MK IV (non SE) model? 

Would I still need the extensions before the C3g converter socket on the non SE if I remove the brass colored bits??

Does anyone have a picture of C3g being used as drivers on their Little Dot MK IV (non SE)?






gibosi said:


> What are the best tubes for the Little Dot?
> 
> This is a question often asked in this forum, and if the person asking doesn't want to mess with 9-pin sockets, Vector socket testers, and external  heater power supplies, the best we could do was suggest the 6HM5, which are not all that good compared to even a mediocre double triode.
> 
> ...


----------



## gibosi

jazzvinyl said:


> Questions regarding use of the C3g on Little Dot amps...
> 
> Does the C3g work on the Little Dot MK IV (non SE) model?
> 
> ...


 
  
 The C3g works fine with LD 1+, II, III, IV and IVSE.
  
 But I will have to leave the other questions to someone who has actually used these tubes in an LDIV.....


----------



## mab1376

hypnos1 said:


> Further observations on 5687 v C3g...given _my_ gear and ears, of course!
> 
> As the Tung Sols were also used tubes, I think I now have enough time on them to get a good idea of what they do...
> 
> ...


 
  
 When i was listening to paranoid android/karma police the other day, i swore it was coming out of my speakers and actually took off the heapdhones to verify, the cg3s are amazing tubes!
  
 Quote:


gibosi said:


> The C3g works fine with LD 1+, II, III, IV and IVSE.
> 
> But I will have to leave the other questions to someone who has actually used these tubes in an LDIV.....



  
  
 The SE and non-SE are the same unit with upgraded parts in the SE, it will work just fine with the adapters.
  
 you can just remove the brass plate and you don't need the risers, there is no rings on the IV.


----------



## JazzVinyl

Excellent! 
  
 Thank you VERY MUCH for the info!!
  
  
  
 Quote:


> The SE and non-SE are the same unit with upgraded parts in the SE, it will work just fine with the adapters.
> you can just remove the brass plate and you don't need the risers, there is no rings on the IV.


----------



## hypnos1

mab1376 said:


> When i was listening to paranoid android/karma police the other day, i swore it was coming out of my speakers and actually took off the heapdhones to verify, the cg3s are amazing tubes!
> 
> Quote:
> 
> ...


 
  
 Yo,mab - their ability to "fill your head", so to speak, never ceases to amaze me, lol!  
	

	
	
		
		

		
		
	


	



  


jazzvinyl said:


>


 
  
 Hi JV.
  
 Glad the guys have put you right re. the C3g...you are in for one REAL treat - they are brilliant even straight out of the box, and they just keep getting better and better up to 50hrs or so burn-in. If you fancy having a go at releasing them from their metal prison, I posted a tutorial some good while ago (if you do, and you can't find it, just post 'help'! and I will search it out for you).
  
 An added bonus of the MKIV and SE is we don't need the extra extenders...GREAT!
  
 HAPPY ROLLING...


----------



## JazzVinyl

Hello hypnos1
  
 I have taken the plunge and ordered the socket adapters, and I _accidentally_ ordered (2) C3m tubes...then realized my mistake, and sent euroklang the extra $10.00 for C3g's - I hope he realizes my mistake, and sends the C3g tubes!!
  
 Really looking forward to the magic of the C3g as drivers!! 
  
 Thanks to all in here for your time and efforts, to help us all get the most from our Tube Amps!!
  
  
  
 Quote:


hypnos1 said:


> Hi JV.
> 
> Glad the guys have put you right re. the C3g...you are in for one REAL treat - they are brilliant even straight out of the box, and they just keep getting better and better up to 50hrs or so burn-in. If you fancy having a go at releasing them from their metal prison, I posted a tutorial some good while ago (if you do, and you can't find it, just post 'help'! and I will search it out for you).
> 
> ...


----------



## hypnos1

jazzvinyl said:


>


 
  
 Well done JV...but I do hope you got your message to euroklang in time, lol! (I'm sure all will be well 
	

	
	
		
		

		
		
	


	




).
  
 I hope also you have no trouble with the adapters..._if_ there should be any problem, it looks like it is soon sorted by the ebayer (but again, I'm sure all will be well!)...
 Now the looong wait...
	

	
	
		
		

		
		
	


	




.
  
 Yes, this thread has to be one of the (if not THE!) best around...


----------



## sssboa

gibosi said:


> The C3g works fine with LD 1+, II, III, IV and IVSE.
> 
> But I will have to leave the other questions to someone who has actually used these tubes in an LDIV.....


 

 OK
  
 But how do they sound comparing to High Quality ef95/91/92? To make it simple I put them in order of bass amount from bassiest to the thinnest:
 EF95 Mullard military > EF95 Russian 80's gold/platinium plate > EF92 Mullard military 
 Where do c3g fit in in terms of amount of bass?
  
 Or in terms of sound stage vs detail from more sound stage and less detail to more detail but less soundstage
 EF95 Tung-Sol 1950s > EF95 JAN > EF95 80s Russian gold/platinium > EF95 RCA 1960s black plate
 Again where would c3g fit in?
  
 Is it improvement really? Won't adapters cause problems similar to having valves with dirty pins?
  
 Now with 5687 power tubes, what will they give me comparing to the popular Russian 80's power tubes?
  
 BTW, I have two LD MK II amps. One with EF92 Mullard military for bass heavy cans and the other one with EF95 Russian for neutral cans.
 Also I assume amps must be set for EF95 valves to use c3g?
  
 Thank you
 Andy


----------



## gibosi

sssboa said:


> But how do they sound comparing to High Quality ef95/91/92? To make it simple I put them in order of bass amount from bassiest to the thinnest:
> EF95 Mullard military > EF95 Russian 80's gold/platinium plate > EF92 Mullard military
> Where do c3g fit in in terms of amount of bass?
> 
> ...


 
  
 1) It has been so long since I have listened to EF91/92 and 95, that I cannot give a detailed answer. I will say that in my opinion, the C3g is several orders of magnitude better than any of the traditional tubes.
  
 2) No, I have never heard any additional noise due to using adapters, and I use lots of them.
  
 3) First, I have an LD 1+, so no power tubes....  However, you might have noticed that many of our group have used 6SN7's as power tubes, and believe them to be better than the traditional Russian tubes. In that the 5687, as a driver, is as good or better than a 6SN7, I would expect them to be better as well. However, if anyone is using these tubes as powers, they haven't gone public, so I don't know..... Could I interest you in being a guinea pig? 
  
 4) Yes, the adapter is designed to convert from 8-pin Loctal to 7-pin EF95, so you would set your LD accordingly.


----------



## sssboa

gibosi said:


> 1) It has been so long since I have listened to EF91/92 and 95, that I cannot give a detailed answer. I will say that in my opinion, the C3g is several orders of magnitude better than any of the traditional tubes.
> 
> 2) No, I have never heard any additional noise due to using adapters, and I use lots of them.
> 
> ...


 

 thx
 So I should rather think of using 6SN7s as power tubes on adapter and with them c3g as drivers on appropriate adapter as well.
 Regards
 Andy


----------



## gibosi

sssboa said:


> Can I use 5687 as driver tubes in LD using some kind of adapter?


 
  
 Yes, you can... but as I replied to Johnnysound about ten posts prior (post #7591), the "adapter" is a bit complicated. The easiest way to accomplish this is to use one 9-pin breadboard socket, two 7-pin test sockets, a laptop power supply providing at least 1.5A, a voltage regulator and some wire.
  
 Cheers


----------



## sssboa

So I think of using 6SN7s as power tubes on adapters and with them c3g as drivers on appropriate adapters as well. Could you please confirm it's sensible and no other devices are needed to make it work?
 I am a bit afraid that it is all overkill for headphones and those tubes are rather for speaker amps. I guess it will make the sound warmer and bassier than what I have currently. I am extremely satisfied with Soviet 6AK5 driver tubes for my Beyer DT880 600ohm but this is too bassy for DT990 600 ohm, and I can't figure out any tubes to sound good with DT990, EF92 are a bit dead sounding.


----------



## hypnos1

sssboa said:


> thx
> So I should rather think of using 6SN7s as power tubes on adapter and with them c3g as drivers on appropriate adapter as well.
> Regards
> Andy


 
  
 Hi sssboa.
  
 That combination will, I am sure, give you results that may well astound you...and then you might want to get even more adventurous and mull over recent postings on using 6AS7G/6080s as power tubes - if you're in the market for a little modding, lol! Then you would be _more_ than astounded!!
  
 Whatever, just like all the rest of us, you are going to discover how our humble LDs can punch WAY above their weight...
	

	
	
		
		

		
		
	


	



  
 Cheers!


----------



## Johnnysound

gibosi said:


> Yes, you can... but as I replied to Johnnysound about ten posts prior (post #7591), the "adapter" is a bit complicated. The easiest way to accomplish this is to use one 9-pin breadboard socket, two 7-pin test sockets, a laptop power supply providing at least 1.5A, a voltage regulator and some wire.
> 
> Cheers


 
 Hi Gibosi, thx again, the "breadboard" is an entertaining DIY project,  looks easier than the 6AS7G/6080s one ¡¡   but lets follow the upgrade path step by step,  I am going to try the 6SN7s as powers first  ( I wonder about the comparative performance of the 5687s as powers, could not find a single post about it)  then swap some different driver tubes (EF92 TS 6485, EF95 Voshkod and EI 6HM5)  to see how they "interact",   only because I am curious about the power tubes contribution to SQ.    Of course, all this experiments before going "up" to the C3gs I am seeing in the near future...


----------



## gibosi

Frankly, I think it is wise to go slowly and to do the easiest things first. And rolling through a few 6SN7's and 5687's as power tubes is indeed easy, requiring only ready-made adapters. 
  
 Again, if anyone is using 5687's as powers, they haven't gone public, so we don't know how good they are. My hunch is that they will be as good, or better than 6SN7's. In my opinion, power tubes provide power, impact and propulsive rhythm to the music. Since the 5687's have 0.9A heaters, compared to 0.6A for the 6SN7's, it seems logical to think that they might provide more power. But until someone tries them and reports back, we just don't know. And since I have an LD1+, I can't roll power tubes, so I have to beg and cajole others to try them for me. lol


----------



## superdux

I might try those adapters but i wished i had more funds, so here's my paypal....haha just joking.
But what if they sound like crap? Anyway my dole money will be tuesday on the account and shipping and handling will sure take 3-4 weeks.
And besides that i'm not that good at describing and memorizing sound signatures.


----------



## Johnnysound

gibosi said:


> Frankly, I think it is wise to go slowly and to do the easiest things first. And rolling through a few 6SN7's and 5687's as power tubes is indeed easy, requiring only ready-made adapters.
> 
> Again, if anyone is using 5687's as powers, they haven't gone public, so we don't know how good they are. My hunch is that they will be as good, or better than 6SN7's. In my opinion, power tubes provide power, impact and propulsive rhythm to the music. Since the 5687's have 0.9A heaters, compared to 0.6A for the 6SN7's, it seems logical to think that they might provide more power. But until someone tries them and reports back, we just don't know. And since I have an LD1+, I can't roll power tubes, so I have to beg and cajole others to try them for me. lol


 
  
 Well, after all the great advice from you and all the pros here, maybe I can make this humble contribution, and check the merits of the 5687s as power tubes.  By chance, found an old repair shop (here in Lima, Peru) that happens to still have, forgotten in their shelves,  a VERY interesting stock of NOS tubes, all kinds, brands and types.  From what I saw, mostly 60s and 70s stock, american and european.  I jumped in expecting the bargain of the century, but no,  the old guy knows that  nobody else has tubes around here, and the guitar amplifier people are his main customers...so he prices his tubes at will.  
  
 He  offered me a pair of NOS Sylvania 5687WB at about $30, and I rejected the offer.  Then he came with a match pair of really nice and solid Tungsram 6SN7GT at $35,   brand new but obviously old stock, sixties I think, and I couldn't resist that famous hungarian brand. This is a very rare NOS tube, found only ONE for sale worldwide (in Italy) at around $40.  Only afterwards I discovered in this very thread that these tubes are, without doubt,  rebranded 60s russian tubes,  but high quality ones.  Forget about Tungsram,  authentic russians from the 60s are also worth trying, I think... He probably will offer me a deal with the Sylvanias, and then I will need the adapters to test them...


----------



## Rossliew

Thanks to @gibosi  I tried some Raytheon 6SN7s and they indeed sound more neutral and engaging as compared to the VT-231 which, whilst sounding full bodies, was a tad too warm and treble rolled-off for my taste. I have regained my faith in the 6SN7s and am now going to pull the trigger on some 5687s as power tubes. Pulling 0.9A, i hope they will sound better than the 6SN7s.
  
 On another note, can someone send me a link to some C3GS tubes for sale? I can't find them over at eBay, only the C3G...many thanks in advance!


----------



## superdux

i have a seller who wants to sell me a cheap batch of C3GS for 10 euro a piece.I could pickup maybe 10 or even more.If anyone is interested they could send me money via paypal including shipping and paypal fees.As for transactions with Head-Fi members i refer to MIKELAP and Vic2Vic.
Please PN me and if i have enough biddings i will edit this post.
The seller is selling them as used but i phoned him and he said they were NOS but he makes no garanty (because they are so old) and serves as is.


Buyers:

Rossliew 2xC3GS
Myself 2xC3GS
Mordy 2xC3GS
Acapella11 2xC3GS
Vic2Vic 4xC3GS
Citizenlin 2xC3GS

Ok no more orders please, maybe next year again.THX


----------



## MIKELAP

superdux said:


> i have a seller who wants to sell me a cheap batch of C3Gs for 10 euro a piece.I could pickup maybe 10 or even more.If anyone is interested they could send me money via paypal including shipping and paypal fees.As for transactions with Head-Fi members i refer to MIKELAP and Vic2Vic.
> Please PN me and if i have enough biddings i will edit this post.
> The seller is selling them as used but i phoned him and he said they were NOS but he makes no garanty (because they are so old) and serves as is.


 
 No problem there .


----------



## hypnos1

rossliew said:


> Thanks to @gibosi  I tried some Raytheon 6SN7s and they indeed sound more neutral and engaging as compared to the VT-231 which, whilst sounding full bodies, was a tad too warm and treble rolled-off for my taste. I have regained my faith in the 6SN7s and am now going to pull the trigger on some 5687s as power tubes. Pulling 0.9A, i hope they will sound better than the 6SN7s.
> 
> On another note, can someone send me a link to some C3GS tubes for sale? I can't find them over at eBay, only the C3G...many thanks in advance!


 
  
 Hi Rossliew.
  
 superdux's arrangement @ 10 euros a piece is a really good offer...but if you want the 'S' version (NOS) here's a link...hope it works! :
  
 http://www.ebay.co.uk/itm/2x-C3g-S-SIEMENS-audio-tubes-NOS-POST-C-3-g-/311099669640?
  
 Obviously they are much more expensive, but of course they're NOS, and I personally found they gave a _little_ bit more than the standard tube (the only indication of 'S' status is on the box - nowhere else, lol!).
  
 So perhaps you have a choice to make, mon ami?...
  
 Cheers!


----------



## gibosi

rossliew said:


> Thanks to @gibosi  I tried some Raytheon 6SN7s and they indeed sound more neutral and engaging as compared to the VT-231 which, whilst sounding full bodies, was a tad too warm and treble rolled-off for my taste. I have regained my faith in the 6SN7s and am now going to pull the trigger on some 5687s as power tubes. Pulling 0.9A, i hope they will sound better than the 6SN7s.


 
  
 Glad to hear you are liking the Raytheons. These are under rated and too often overlooked in my opinion. I would also recommend the Tung-Sol mouse ears and perhaps a pair of Sylvanias.


----------



## TheClarifier

Newb mistake. Won't happen again. Sorry.


----------



## TheClarifier

i luvmusic 2 said:


> Don't forget to CRYO them.


 
 Sorry @ i luvmusic 2 , can you explain what you mean by "Cryo them"? Sorry for my newb-ness.


----------



## sssboa

hypnos1 said:


> Hi sssboa.
> 
> That combination will, I am sure, give you results that may well astound you...and then you might want to get even more adventurous and mull over recent postings on using 6AS7G/6080s as power tubes - if you're in the market for a little modding, lol! Then you would be _more_ than astounded!!
> 
> ...


 

 OK, thx
 Just ordered a pair of c3g and 6SN7 with all adapters.
 I took 6SN7 vintage Sylvania nice looking black plate, chrome top, moderately priced, I doubt they affect quality really so want them to be lookers


----------



## CITIZENLIN

Hello , sssboa


You wont regret your investment on C3g and 6SN7. I am still amaze every time I listen to it my LD MK IV. Thanks to gibosi, hypnos1, mordy TrollDragon among others on the board.


----------



## mordy

Hi TC,
  
 Cryogenic treatment means taking the tube slowly to extremely cold temperatures and then very slowly bringing the tubes back to room temperature. Liquid nitrogen is used. This procedure is said to reorient the molecular pattern more uniformly and strengthen the material, be it steel or other metals, glass or plastics.
  
 Apparently this method is used to make certain tools last longer, and it has many applications in industry, such as high performance car parts etc.
  
The question is if it benefits vacuum tubes. From the cursory reading I did, it seems that although there are differences in sound after cryogenic treatment, most posts I read noticed _no improvement or degradation _of the sound, but, as always, some said that it helped.
  
 IMHO researching and buying the best tubes for you application will yield much better results.
  
 My personal impression is that tube dampers and cryogenic treatments are on the same level as snake oil as far as tubes go.


----------



## Rossliew

Anyone has a spare pair of 7-pin miniature test sockets for sale? I've contacted Leeds Radio for it but they have just shifted to a new premise and the shop will only open in November...
  
 I tried eBay but couldn't find the same or similar product. If anyone can help, it will be most appreciated!


----------



## i luvmusic 2

theclarifier said:


> i luvmusic 2 said:
> 
> 
> > Don't forget to CRYO them.
> ...


 
 Hi!
    Pardon me for bringing the CRYO up i was just teasing TD,Read MORDY's post that explain some of the CRYO treatment/uses.THANKS! for saving my A55 Mordy.


----------



## superdux

rossliew said:


> Anyone has a spare pair of 7-pin miniature test sockets for sale? I've contacted Leeds Radio for it but they have just shifted to a new premise and the shop will only open in November...
> 
> 
> 
> ...



 


found this from an old post of gibosi

http://www.radiodaze.com/product/15450.aspx


----------



## Rossliew

superdux said:


> rossliew said:
> 
> 
> > Anyone has a spare pair of 7-pin miniature test sockets for sale? I've contacted Leeds Radio for it but they have just shifted to a new premise and the shop will only open in November...
> ...


 
 Thanks, dude! Shall order a pair now..


----------



## Rossliew

Darn! It doesn't ship to Malaysia


----------



## superdux

then try them

http://www.vacuumtubesinc.com/Products/SocketsAdaptersParts/Adapters.aspx


----------



## Acapella11

Good job Superdux, I'll take 2


----------



## gibosi

superdux said:


> rossliew said:
> 
> 
> > Anyone has a spare pair of 7-pin miniature test sockets for sale? I've contacted Leeds Radio for it but they have just shifted to a new premise and the shop will only open in November...
> ...


 
  
 These will work fine. However, they are a bit tall! lol 
  
 I use these test sockets along with my 9-pin adapter to run double triodes, but as you can see, you can still use them with 7-pin tubes.
  
 Edit: Just make sure you don't have a double triode plugged in at the same time!!


----------



## mordy

Another less elegant solution, but less expensive, would be to connect two *loctal* breadboards to the Vectors. This would cut the cost of the adapters in half from $60 to $30 (for those of us that have the Vector 7pin adapters).
  
 http://www.ebay.com/itm/200958131372?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT
  
 (I have a 9pin bread board from the same supplier and the quality is good.)
  




  
 There is a US supplier of a bread board that does not require soldering in little wires in the place of the spaces for resistors as above, but it costs $24  so I don't think this version is worth it compared to the $30 custom made adapter.
 http://www.ebay.com/itm/8-pin-loctal-breadboard-prototype-tube-socket-for-DIY-experimenting-NOT-OCTAL-/161397121735?pt=Vintage_Electronics_R2&hash=item259404a2c7


----------



## vic2vic

superdux said:


> i have a seller who wants to sell me a cheap batch of C3GS for 10 euro a piece.I could pickup maybe 10 or even more.If anyone is interested they could send me money via paypal including shipping and paypal fees.As for transactions with Head-Fi members i refer to MIKELAP and Vic2Vic.
> Please PN me and if i have enough biddings i will edit this post.
> The seller is selling them as used but i phoned him and he said they were NOS but he makes no garanty (because they are so old) and serves as is.
> 
> ...


 
  
 Count me in mate


----------



## i luvmusic 2

mordy said:


> Another less elegant solution, but less expensive, would be to connect two *loctal* breadboards to the Vectors. This would cut the cost of the adapters in half from $60 to $30 (for those of us that have the Vector 7pin adapters).
> 
> http://www.ebay.com/itm/200958131372?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT
> 
> ...


 
 Hey Mordy!
  The first picture,I'am wondering  if you can install a resistor on the board to limit the current going into the MK III from the 6AS7G tubes.Will these work?
 Maybe TD and Gibosi can comment on these.THANK YOU!


----------



## superdux

My experience with the 78' 6N23P Voskhod tube: these had no burn-in and i probably listened about 6hrs in total spanning 2 days. I experienced a tad lesser bass than the 79', the detail still has to be considered but they have a very contoured, crystal(liquid) like ( i thought of ice but not in the sense of cold but its luminal abilities) mid section with pleasant male voices and strings.It took a bit to get used to this sound sig but i like them a lot having a 4 hour listening session today also trying different HPs from my collection. Were they better than the 79'? That depends on your listening habits: the 79's are clearly detailed, have a nice bass section and nice mids giving you a pleasant listening experience.

Albums listened to:

Anthony and the Johnsons- I am a bird now
The Beatles- White album
Nick Drake- Pink Moon

EDIT/UPDATE: now the tubes must have 10-12hrs on them and the sound sig has become more smoother than in the beginning. I just listened to some Aphex Twin-Syro and could hear nice details with this tube through my HD650. The bass is also more pronounced now. The mids are not so hard/contoured as in the beginning but have some silky smoothness to them. There's still a hint of the brilliant tonal quality there, what i described as "ice-like". But all has gotten rounder now and they are certainly one of the best tubes for the Little Dot considering you'll need a handmade adapter. Maybe ask here for someone to build one for you if you're not that tech-savy.


----------



## Rossliew

superdux said:


> My experience with the 78' 6N23P Voskhod tube: these had no burn-in and i probably listened about 6hrs in total spanning 2 days. I experienced a tad lesser bass than the 79', the detail still has to be considered but they have a very contoured, crystal(liquid) like ( i thought of ice but not in the sense of cold but its luminal abilities) mid section with pleasant male voices and strings.It took a bit to get used to this sound sig but i like them a lot having a 4 hour listening session today also trying different HPs from my collection. Were they better than the 79'? That depends on your listening habits: the 79's are clearly detailed, have a nice bass section and nice mids giving you a pleasant listening experience.
> 
> Albums listened to:
> 
> ...


 
  
 I've tried the 6N23P a power tubes but due to their low current draw , the sound is not as full bodied as I'd like. All in all, these are not really suitable as power tubes IMO. Neither were the 6N1Ps except for some Amperex 6922s, if I'm not mistaken. The golden globes..


----------



## Rossliew

superdux said:


> then try them
> 
> http://www.vacuumtubesinc.com/Products/SocketsAdaptersParts/Adapters.aspx


 
 Thanks..have just placed my order


----------



## gibosi

rossliew said:


> I've tried the 6N23P a power tubes but due to their low current draw , the sound is not as full bodied as I'd like. All in all, these are not really suitable as power tubes IMO. Neither were the 6N1Ps except for some Amperex 6922s, if I'm not mistaken. The golden globes..


 
  
 The 6N23P, 6922 and 6DJ8/ECC88 have only 0.30A heaters and there appears to be considerable consensus that they do not work well as power tubes. However, 6N1P and 6N5P have 0.6A heaters, the same as 6SN7, so they just might be better. However, I do not know if anyone here has tried them....


----------



## Rossliew

gibosi said:


> The 6N23P, 6922 and 6DJ8/ECC88 have only 0.30A heaters and there appears to be considerable consensus that they do not work well as power tubes. However, 6N1P and 6N5P have 0.6A heaters, the same as 6SN7, so they just might be better. However, I do not know if anyone here has tried them....


 
 Hmm..i didn't find the 6N1P to be a good match either (or maybe there's no synergy in my rig) although I noted that the Amperex's had a fuller sound. I shall try and give it another round of listening tonight. For now, the Raytheon 6SN7s are giving me a lot of musical and emotionally engaging listening times!


----------



## gibosi

i luvmusic 2 said:


> The first picture,I'am wondering  if you can install a resistor on the board to limit the current going into the MK III from the 6AS7G tubes.Will these work?
> Maybe TD and Gibosi can comment on these.THANK YOU!


 
  
 Just to clarify, these are Loctal breadboard sockets for use with C3g. To use breadboard sockets to run 6AS7's, it would be necessary to purchase Octal sockets. As to whether adding resisters to an octal socket would make it more safe run 6AS7's, I have no idea...
  
 For those interested in exploring this possibility it might be a good idea to reread lemonjelly's posts regarding his modifications. Specifically, I cannot remember if he suggested adding resistance or lowering resistance?
  
 http://www.head-fi.org/newsearch/?search=&resultSortingPreference=recency&byuser=lemonjelly&output=posts&sdate=0&newer=1&type=all&containingthread%5B0%5D=563884&advanced=1
  
 And maybe lemonjelly would be willing to offer his opinion regarding the feasibility of this idea.....


----------



## mordy

Hi i luvmusic 2,
  
 These breadboards are very versatile, and each lead, be it 8 or 9 leads depending on model, has two screw posts and two leads for resistors. However, the double screw posts and resistor leads are connected; in other words, soldering in one resistor will effect both screw terminals for that lead.
  
 I have one such breadboard, and I had to solder in wires into the place of the resistors to connect the tube socket pins to the screw posts. It is very easy to connect the outgoing wires securely using a small flat blade screw driver.
  
 There should be no problem to add resistors to specific pins as this board is designed for it.


----------



## mordy

Hi Rossliew,
  
 Re power tubes I tried four different variants of the 6N6P family - the IR were the best in this group. Then tried 6CG7/6FQ7 but these tubes were not a good match for the LD as power tubes. Then the 6SL7 - good, but light weight in the bass region.
  
 The 6SN7 are very nice as power tubes, but have a light feel to them as well.
  
 Seems that when it comes to power tubes bigger is better, and the 6AS7 and 6080 tubes have all the heft and bass authority that you want. At this time I am using a GE 5687WA as driver and am trying various 6080 tubes. With this 5687 they all sound very good, be it Chatham, GE, Sylvania or RCA. The differences don't seem to major with this combination - there may be small differences in the control of the bass mainly.
  
 Way back in 2009 some people on this forum tried the 5687 as both power and driver tubes with good results. Since they draw 0.9A my guess is that they may sound similar to the 6SN7 but maybe a little better bass.
  
 Now I hope to get the Cg3 tubes - curious how they will stack up. Trying to figure out inexpensive adapters for these tubes.... Suggestions anybody?


----------



## superdux

Way back in 2009 some people on this forum tried the 5687 as both power and driver tubes with good results. Since they draw 0.9A my guess is that they may sound similar to the 6SN7 but maybe a little better bass.


 



 


do you know in which thread that was? I'm considering getting them as power tubes with an adapter.


----------



## gibosi

superdux said:


> Way back in 2009 some people on this forum tried the 5687 as both power and driver tubes with good results. Since they draw 0.9A my guess is that they may sound similar to the 6SN7 but maybe a little better bass.


 
  
  
 http://www.head-fi.org/t/301219/review-of-the-diy-6h6n-to-e182cc-5687-tube-adapters-bullplugs-for-ld-mkii-mkiii-headphone-amplifiers


----------



## Rossliew

mordy said:


> Hi Rossliew,
> 
> Re power tubes I tried four different variants of the 6N6P family - the IR were the best in this group. Then tried 6CG7/6FQ7 but these tubes were not a good match for the LD as power tubes. Then the 6SL7 - good, but light weight in the bass region.
> 
> ...


 
  
  
 I would surely love to try the 6AS7/6080 tubes as power but the need to have an external heater PSU is keeping me away..am just not a DIY person. So, for now, I will stick to plug and play tubes first. Next on the list is the 5687s as power tubes..


----------



## superdux

thx gibosi,

i was wondering how much ampere the 6H6N draw?

EDIT: i think i found it~around 0,7Ampere

so the 6N30P-DR have around 100mA...is that right?


----------



## gibosi

superdux said:


> thx gibosi,
> 
> i was wondering how much ampere the 6H6N draw?
> 
> ...


 
  
 The 6N30P-DR draws 0.825A, so just a bit less than a 5687.
  
 http://www.tubeampdoctor.com/images/File/Specifications%206N30P.pdf


----------



## Acapella11

gibosi said:


> These will work fine. However, they are a bit tall! lol
> 
> I use these test sockets along with my 9-pin adapter to run double triodes, but as you can see, you can still use them with 7-pin tubes.
> 
> Edit: Just make sure you don't have a double triode plugged in at the same time!!


 

 Cheers gibosi, I have ordered yours


----------



## superdux

ok folks, i have enough orders and the seller has promised me to send, so hopes all will go well and they work too!

BTW thx to gibosi for your help

If the tube group buy works out well and the seller still has some tubes i will do another group buy next year.


----------



## hypnos1

mordy said:


> Hi Rossliew,
> 
> Re power tubes I tried four different variants of the 6N6P family - the IR were the best in this group. Then tried 6CG7/6FQ7 but these tubes were not a good match for the LD as power tubes. Then the 6SL7 - good, but light weight in the bass region.
> 
> ...


 
  
 Hey mordy...looks like you're gonna have to make your own, lol!


----------



## mordy

Tutorial?


----------



## JazzVinyl

Hello hypnos1...
  
 Good news, I did get the message to euroklang in time, and he says he is sending two NOS C3gS's..!  Yeah!
  
 I would indeed be interested in your guide to removing the black metal C3g sheaths...and cannot find your guide...so here an official: "HELP"...!
  
 Also ordered the adapters and pair of GSN7's..just to see...might go the full monte of your suggested 6AS7G w/external heater supply. 
 Sounds like it would make a fun "Winter Project"!
  
  
  
 Appreciate..
  
  
  
  
 Quote:


hypnos1 said:


> Hi JV.
> Glad the guys have put you right re. the C3g...you are in for one REAL treat - they are brilliant even straight out of the box, and they just keep getting better and better up to 50hrs or so burn-in. If you fancy having a go at releasing them from their metal prison, I posted a tutorial some good while ago (if you do, and you can't find it, just post 'help'! and I will search it out for you).
> 
> An added bonus of the MKIV and SE is we don't need the extra extenders...GREAT!
> ...


----------



## gibosi

> I would indeed be interested in your guide to removing the black metal C3g sheaths...and cannot find your guide...so here an official: "HELP"...!


 
  
 Just remember... Siemens designed these tubes to have a lifetime of 10,000 hours inside their black metal sheaths. The only reason to take them off is cosmetic. But to be frank, they really don't put on that much of a show. And in my opinion, given the amount of work it takes and the very real chance that something might go wrong, it simply isn't worth the trouble. But of course, I fully expect Hypnos1 will argue otherwise.


----------



## CITIZENLIN

Hello everyone,
  
 It have been a while but I missed reading / learning /new finding here. I've been listening / tube rolling many 6sn7s in past few months. Hope everyone is doing well here.


----------



## JazzVinyl

Very nice, Citizenlin!
  
 You appear to be using the exact combination that I hope to be enjoying, within a month.
  
 So what's your favorite 6sn7 thus far? 
  
 Are the C3g's all they say they are?
  
 Appreciate...
  
  
  
 Quote:


citizenlin said:


> Hello everyone,
> 
> It have been a while but I missed reading / learning /new finding here. I've been listening / tube rolling many 6sn7s in past few months. Hope everyone is doing well here.


----------



## i luvmusic 2

mordy said:


> Hi Rossliew,
> 
> Re power tubes I tried four different variants of the 6N6P family - the IR were the best in this group. Then tried 6CG7/6FQ7 but these tubes were not a good match for the LD as power tubes. Then the 6SL7 - good, but light weight in the bass region.
> 
> ...


 
  
  


gibosi said:


> i luvmusic 2 said:
> 
> 
> > The first picture,I'am wondering  if you can install a resistor on the board to limit the current going into the MK III from the 6AS7G tubes.Will these work?
> ...


 
 I guess i have some reading to do.THANKS GUYS!


----------



## CITIZENLIN

Oh yeah, Pictures are for you to see, I saw your post about LD IV and C3gs, 6sn7. I am still loving it everyday. My fav 6sn7 is Tung sol 6sn7 GTB or Tung sol 6SN7 GT clear glass which I got them for around 10.00ea. If money doesn't matter just go for Tung sol 6sn7GT vt231 black glass.

1. Tung Sol 6SN7 GT VT 231 (Oval or Roung plate, black glass)
2. Ken Rad 6SN7 GT VT 231 black glass / super tight bass
3. Sylvania 6SN7 GT VT231
4. Tung Sol 6SN7 GT/GTB clear glass
5. RCA 6SN7GT grey glass

These are my top 5 in order.


----------



## mordy

Hi Citizenlin,
  
 Am I correct that you use tube damper rings on your octal tubes? Could you describe what effect they have on the sound?


----------



## CITIZENLIN

mordy said:


> Hi Citizenlin,
> 
> 
> 
> ...



 

Hello Mordy

 Yes , They are tube damper silicone rings. Sonically I couldn't tell any changes by my ears. I got them cheap to serve as tube protector/sonic improvement. Now they are just protector rings.


----------



## i luvmusic 2

The rings reminds me of a C...oms................


----------



## CITIZENLIN

lol I still get my eargasm with or without protections.


----------



## i luvmusic 2

It's too bad for me i can't have eargasm with the LD my wife is using it and the CRACK my kid have it too i'am back using my Bravo Ocean.
	

	
	
		
		

		
		
	


	




 
 The LD 1 is not that good with HD 650.


----------



## superdux

I bought these tubes:



> For sale two 5687 tubes , by Raytheon , made in USA,( old version from 50 decade ) . No visible sign of usage, in good condition.
> 
> The tubes have black plates, and square getter on the top.
> 
> Tested on my Hickok 752A tube tester and the readings are: 825-850 , 850-850 (1-2%) , The minimum good reading of 5687 tubes on this tester is 475-475




from ebay and am waiting for adapter and socket saver. So i'll give a feedback on this in a few weeks.


----------



## JazzVinyl

Appreciate the photos you posted, Citizenlin....thank you.
  
 Also appreciated your 6SN7 Tube listening impressions.
  
 I have a couple of older 6SN7's made my "WG & Co" who are not mentioned in the 6SN7 Reference thread.  I will start my 6SN7 adventures,  there.
  
 I love the idea of your suggested "Tung sol 6sn7GT vt231 black glass" but seems they are worth their weight in gold!  So will have to give that some considered thought.
  
 Again...appreciate your help...
  
 ...JV...
  
 Quote:


citizenlin said:


> Oh yeah, Pictures are for you to see, I saw your post about LD IV and C3gs, 6sn7. I am still loving it everyday. My fav 6sn7 is Tung sol 6sn7 GTB or Tung sol 6SN7 GT clear glass which I got them for around 10.00ea. If money doesn't matter just go for Tung sol 6sn7GT vt231 black glass.
> 
> 1. Tung Sol 6SN7 GT VT 231 (Oval or Roung plate, black glass)
> 2. Ken Rad 6SN7 GT VT 231 black glass / super tight bass
> ...


----------



## superdux

I'd like to measure the C3GS tubes i bought, so could someone explain me how and if it's possible using a multimeter to determine if the tube still has some life in it.
 Maybe you'll want to edit my uploaded pics and point me to the pins i have to measure and what i have to do on my multimeter:resistance in ohm maybe?)
 Thx for help and reply.


----------



## TrollDragon

A meter will not test the life of the tubes, unless it looks similar to the one below...


----------



## superdux

Oh ok, 

then we'll hope for the best!


----------



## hypnos1

superdux said:


> Oh ok,
> 
> then we'll hope for the best!


 

 Hi superdux.
  
 With a projected life of 10,000 hrs plus, hopefully they should outlast you, lol!...Assuming they haven't been nuked, of course!  
	

	
	
		
		

		
		
	


	



  
 But I shall cross everything in hope for yourself - and everyone else...


----------



## hypnos1

jazzvinyl said:


>


 
  
 Hi JV.
  
 Sorry for the late reply...lots goin' on at the moment (not least trying to keep a grip on the Feliks-Audio project, lol!).
  
 Gibosi certainly has a point, but so long as you're careful and _reasonably_ proficient with a small pair of pliers, it's not that tricky. Will search out the tutorial in question and re-post, if interested.
  
 And to remind you of how they look unleashed....:
  

  
 Don't forget I have made permanent adapters for mine, but at least you get an idea of how they look...
  
 So the choice is yours!


----------



## hypnos1

mordy said:


> Tutorial?


 
  
 Hi mordy.
  
 My original one -  which was basically a permanent adapter, relying on everything going 100% to plan -  I now realise is somewhat risky for those who are new to making such an animal.
  
 So I would really like to come up with something easier and less risky, for yourself and others -  if interested...and such that you (and all non-MKIV owners) wouldn't need those pesky extenders in addition, lol! The only trouble is I'm short on time at present, so it could mean a month or more's wait I'm afraid. If you're willing to wait, I shall sincerely do my best to put together a new tutorial.
  
 Cheers.
  
 CJ


----------



## mordy

Hi hypnos 1,
  
 Thanks for your offer - I'll wait for you to post your tutorial.
  
 I do not find the 9pin extenders pesky except for aesthetics. I have several of them and they come to good use, both for clearing the decorative rings with wide adapters and for the sub miniature 7963 tube. Also converted two of them for use with an external power supply for power tubes.
  
 You can find four of them for around $7 shipped:
  
 http://www.ebay.com/itm/4pc-9PIN-Bakelite-vaccum-TUBE-SOCKET-SAVER-base-FOR-12AX7-12AU7-ECC82-ECC83-amps-/151027969922?pt=Vintage_Electronics_R2&hash=item2329f7ef82
  
 Not the greatest quality, but they get the job done.


----------



## superdux

Hi hypnos1,

assuming they are NOS i have to believe the guy,
but i'll fire some up as soon as they arrive.


----------



## JazzVinyl

Hello hypnos1
  
 I do like the way the C3g's look un-sheathed, and your "Permanent adapters" too, make your amp look really professional!!
  
 I would like a Tutorial on making the Permanent adapters, for sure!!
  
 Also looks like your running the external juice to your 6AS7G's through the amp and up to the Tubes from below?  If, so, I would like my copy of the Tutorial on how to do that, too,
 please 
  
 The Felkis-Audio project sounds intriguing and if it really comes to pass at the $500.00 mark, I will be ordering one!  Fingers crossed!!
  
 I am considering leaving my C3g's sheathed, and maybe painting the metal sleeves, some groovy colors?  But we'll see how it goes.  As I said, I really like the look you have there with your "permanent adapters"!!  Do you sell them?
  
 Appreciate the photo....!!!!
  
 Quote:


hypnos1 said:


> Hi JV.
> 
> Sorry for the late reply...lots goin' on at the moment (not least trying to keep a grip on the Feliks-Audio project, lol!).
> 
> ...


----------



## gibosi

jazzvinyl said:


>





> Also looks like your running the external juice to your 6AS7G's through the amp and up in to the Tubes from below?  If, so, I would like my copy of the Tutorial on how to do that, too,
> please


 
  
 Mordy put together a very nice tutorial on how to hook up an external heater power supply for 6AS7/6080 type tubes:
  
 http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/6405#post_10612269


----------



## superdux

I've updated my 78' 6N23P listening experience:

http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/7620#post_10917585


----------



## MIKELAP

Received some 6HM5 yugo's today ,no wonder people around here love them so much nice punchy sound bass is very good thats with SIMPLY REDS GREATEST HITS album and HD800 cant go wrong with those tubes one problem tough dum dum cant pack tubes so out of 10 tubes 2 were broken these things were bouncing all over the place i was slightly annoid to say the least so you better believe he's goig to send me 2 more tubes  Heres what a disaster looks like poor baby's,WHAT  tubes need love too LOL.  Ya i know get a life !  Got a little advance Christmas gift today a nice pair of dimpled Tung Sol 5998.


----------



## i luvmusic 2

mikelap said:


> Received some 6HM5 yugo's today ,no wonder people around here love them so much nice punchy sound bass is very good thats with SIMPLY REDS GREATEST HITS album and HD800 cant go wrong with those tubes one problem tough dum dum cant pack tubes so out of 10 tubes 2 were broken these things were bouncing all over the place i was slightly annoid to say the least so you better believe he's goig to send me 2 more tubes  Heres what a disaster looks like poor baby's,WHAT  tubes need love to LOL.  Ya i know get a life !  Got a little advance Christmas gift today a nice pair of dimpled Tung Sol 5998.


 
 I'am sorry about your 6HM5!
 Congratz! On your 5998.......


----------



## TrollDragon

Sorry for your loss on the 6HM5's and congrats on the dimple's!

Yes the threat of negative feedback for poor packaging should have him sending you replacement tubes pronto!


----------



## mordy

Hi,
  
 Just popped in my beautiful aesthetically pleasing coke bottle Chatham 6AS7 tubes as power tubes, using a GE 5687 as driver. Alas, something was bothering me with the sound. After allowing the tubes to warm up for 1/2 hour I listened carefully again - the sound changed a little, but something is still amiss.
  
 Yep - figured it out: The bass is mushy and flabby even though it goes very low. With this combination the 6080 "industrial grade" tubes have more punch and better definition and control of the bass.  Have no idea why people like to call the 6080s "Industrial Grade." The benefit to tube rollers is that you can pick up these tubes for $2-3 if you buy several at a time.
  
 It may very well be that the 6AS7 sounds great with other driver tubes, but the 5687 excels at clarity, detail and definition in the mid bass, and to me the 6080 is a better match. I am not a bass freak, but I enjoy the clarity and extra detail in the bass, allowing me to hear new things in the recordings. My favorite 6080 is set of 60's Sylvanias, but the RCA, GE and Chatham that I have all sound very good.
  
 Go 6080!


----------



## hypnos1

mordy said:


> Hi,
> 
> Just popped in my beautiful aesthetically pleasing coke bottle Chatham 6AS7 tubes as power tubes, using a GE 5687 as driver. Alas, something was bothering me with the sound. After allowing the tubes to warm up for 1/2 hour I listened carefully again - the sound changed a little, but something is still amiss.
> 
> ...


 
  
 Hi mordy.
  
 That is real strange, how your findings are so different to many others - especially re. the Chatham 6AS7Gs...I'm definitely gonna have to try some 6080s and see what's going on, lol! 
	

	
	
		
		

		
		
	


	




 
  
 ps. Do you have the red-label RCAs?...


----------



## mordy

Hi hypnos 1,
  
 I do not have the red label RCAs. Read somewhere that a dealer had a large stock and decided to hype up these RCA tubes with a red base. The article that I read had the opinion that these tubes are over-rated and don't sound that great. A case of the "Emperor's new clothes?"
  
 Just one quote - there are others:
  
_"The red base tubes do not have the same specs as the other 6SN7's and need to be run at a lower point, the reason for the longer life. You can run them at the same points but they will not last any longer than a normal tube. Also, and this is very important and backed up with much listening from me and friends who know what they are talking about, the tube is not that great and I do not even consider it a good 6SN7 type. There is just much hype that has gone with it."_
  
 My approach when trying a new tube is to get a selection of different ones and just listen. Doing it this way excludes expensive "boutique" type tubes or expensive tubes in general. However, I have been able to find very good sounding tubes that are not that well known (or unknown) for very reasonable prices.  One example of such a find from people on the blog is the Ei or Sylvania 6HM5 that most people agree trumps any 6AK5 variant. It can be bought for $5.
  
 With the 6SN7 tubes I found a RCA with a thin horizontal heater wire above the top mica that sounds excellent. This tube can be found for a few bucks.
  
 Can it really be that only the most expensive tubes sound good?


----------



## JazzVinyl

Hello mordy...
  
 Are you using the 6HM5's as drivers?  Or power?
  
 And...
  
 Have you tried the fabled C3g as drivers?
  
  
  
 Quote:


mordy said:


> My approach when trying a new tube is to get a selection of different ones and just listen. Doing it this way excludes expensive "boutique" type tubes or expensive tubes in general. However, I have been able to find very good sounding tubes that are not that well known (or unknown) for very reasonable prices.  One example of such a find from people on the blog is the Ei or Sylvania 6HM5 that most people agree trumps any 6AK5 variant. It can be bought for $5.
> With the 6SN7 tubes I found a RCA with a thin horizontal heater wire above the top mica that sounds excellent. This tube can be found for a few bucks.
> 
> Can it really be that only the most expensive tubes sound good?


----------



## mordy

Hi JazzVinyl.
  
 In the past I used the Yugoslavian Ei 6HM5 tubes as drivers. They are quite good and perhaps the best of all "plug and play" tubes for the Little Dot MKIII (meaning that you do not need any adapters or modifications - just plug them in). These tubes are not suitable as power tubes.
  
 When i first plugged them in I got a scare because they flashed up and I thought they would explode. However, this is just a quick heat feature built in into the tube - makes for a second of fireworks, though.
  
 There are much better tubes to use as drivers, but all of them will require adapters and modifications.
  
 I hope to get the C3g tubes in the near future. At the present I am using single tubes (dual triodes) as drivers with 2.5A power tubes with very good results.
  
 Anything you try that will sound better than the 6HM5 tubes will require some kind of adapter/voltage regulator/power supply etc.


----------



## hypnos1

jazzvinyl said:


>


 
  
 Hi again JV.
  
 If you decide to go ahead with the unleashing, I have (finally!) found the post in question - #5683, page 379.
  
 I believe mab (or was it another convert?!) didn't bother to glue the metal base to the tube, which is fine. But I do recommend making  alignment marks (with a CD marker, for example) on the tube and metal base at the corresponding 'church window' locations...And please follow the instructions VERY carefully..
	

	
	
		
		

		
		
	


	



  
 As for the adapters, my 'permanent' ones had the tube pins soldered direct to the extensions, which is much trickier, riskier and less flexible than a stand-alone adapter. So I shall be looking to put together the latter...when I can get around to it, lol!
  
 And re. my external power supply leads, no fancy routing up from inside the case I'm afraid - the black wires just blend nicely into the top of the case!
  
 Good luck!


----------



## JazzVinyl

There is an old junky store here, that has lots of dusty tubes in bins...I went today at lunch, and found two NIB Raytheon 6HM5's for 3 bucks each.
  
 Came back to work, and popped them in the MK IV...
  
 I do like them, a lot!  I think they are better than the Voshkod 6ZH1P-EV's that they replaced (that I paid about 2x the price for).
  
 The 6HM5's seem better (clearer) on both ends of the audio spectrum, to me.
  
 Mine do not have the "fireworks" you described....
  
 Thanks for the suggestion, mordy!
  
  
 Quote:


mordy said:


> Hi JazzVinyl.
> 
> In the past I used the Yugoslavian Ei 6HM5 tubes as drivers. They are quite good and perhaps the best of all "plug and play" tubes for the Little Dot MKIII (meaning that you do not need any adapters or modifications - just plug them in). These tubes are not suitable as power tubes.
> 
> ...


----------



## i luvmusic 2

You guys can call me CRAZY if i tell you  i run 6DN7 on my CRACK and darn it sound good no channel imbalanced no hum what so ever despite the different section of the 6DN7"s
	

	
	
		
		

		
			




 LD MK III's turn for the 6DN7's as driver's first then maybe power later on........


----------



## i luvmusic 2

YUP!The 6DN7  does work with the MK III no hum lots of details perhaps it's bright sounding.........


----------



## i luvmusic 2

Dumb me i was wondering why this 6DN7's light up BRIGHT and sounds really bright i forgot to reduce the heater voltage to 6.3V the regulator was set to 12V for the 12SN7's(FAIL)
   Running it now with 6.3V very nice it give more Bass for my DT880.


----------



## gibosi

> There is an old junky store here, that has lots of dusty tubes in bins...I went today at lunch, and found two NIB Raytheon 6HM5's for 3 bucks each.
> 
> Came back to work, and popped them in the MK IV...


 
  
 I don't think Raytheon made these...  Do these have a tall bottle?  Or short, like your Voskhods?


----------



## JazzVinyl

The boxes say Raytheon 6HM5 6HA5
  
 One was tall and marked:
 6HQ5 Motorola Golden "Premium Rated" Made in U.S.A
  
 The other is short, and marked:
 6HA5 6HM5 Amperex made in Great Britian
  
 But both were in what appears to be new Raytheon 6HM5 6HA5 red and white boxes, "Excelence in Electronics"
  
 There is no doubt that I like the way they sound a lot better than the Voskhods, they dig out a heck of a lot more subtle detail.
  
 Quote:


gibosi said:


> I don't think Raytheon made these...  Do these have a tall bottle?  Or short, like your Voskhods?


----------



## JazzVinyl

Mine were not, but here are some that are branded Raytheon:
  
 http://www.ebay.com/itm/Set-of-3-NOS-Raytheon-6HM5-6HA5-vacuum-tubes-audio-amplifier-amp-ham-radio-/111468130821
  
 My boxes look exactly like these...
  
 Quote:


gibosi said:


> I don't think Raytheon made these...  Do these have a tall bottle?  Or short, like your Voskhods?


----------



## gibosi

jazzvinyl said:


>





> One was tall and marked:
> 6HQ5 Motorola Golden "Premium Rated" Made in U.S.A
> 
> The other is short, and marked:
> 6HA5 6HM5 Amperex made in Great Britian


 
  
 It is not likely that these will sound the same. My best guess is that the Motorola tube is a rebranded Sylvania, and this is generally considered to be a good sounding tube.  All the short ones I have seen were actually manufactured by Siemens, regardless of what is printed on the bottle, and I, for one, don't like them much.
  
 The Amperex tube likely has Philip's production codes. Check out this document to see if it was in fact manufactured by Siemens:
  
 http://tubedata.milbert.com/other/Philips/PhilipsCodeListAB-v10.pdf


----------



## gibosi

jazzvinyl said:


>





> Mine were not, but here are some that are branded Raytheon:
> 
> http://www.ebay.com/itm/Set-of-3-NOS-Raytheon-6HM5-6HA5-vacuum-tubes-audio-amplifier-amp-ham-radio-/111468130821


 
  
 Even though these carry the Raytheon label, I am quite sure that Raytheon did not make 6HM5 tubes. So it is likely they were procured from another manufacturer and relabeled. And in this case, they were procured from two different manufacturers and relabeled. Again, based on my experience, the short ones are likely Siemens, and the tall one is likely Sylvania or Philips/Mullard.


----------



## JazzVinyl

Very good, appreciate the info..

One of the two was really digging out the details, today. It was exciting to hear.

I have five GE brand tall 6MH5's inbound from an ebay vendor...20.00 shipped. So, looking forward to a pair that sound the same. 



gibosi said:


> Even though these carry the Raytheon label, I am quite sure that Raytheon did not make 6HM5 tubes. So it is likely they were procured from another manufacturer and relabeled. And in this case, they were procured from two different manufacturers and relabeled. Again, based on my experience, the short ones are likely Siemens, and the tall one is likely Sylvania or Philips/Mullard.


----------



## JazzVinyl

Hello hypnos1...

Yes, thank you, found your C3g sheath removal guide, and it's absolutely perfect!! Explained the whole deal, much appreciate your effort to find the post.

Looking forward to seeing what you come up with on the permanent adapters. 

Again, very much appreciate your time and effort! 

Cheers!,





hypnos1 said:


> Hi again JV.
> 
> If you decide to go ahead with the unleashing, I have (finally!) found the post in question - #5683, page 379.
> 
> ...


----------



## hypnos1

jazzvinyl said:


> Hello hypnos1...
> 
> Yes, thank you, found your C3g sheath removal guide, and it's absolutely perfect!! Explained the whole deal, much appreciate your effort to find the post.
> 
> ...


 
  
 Hi JV.
  
 Glad you found it OK and that you like it...any problems/questions just shout!
  
 Re. the (stand-alone) adapters, I would like to think I'll have time (?!) to make a few pairs to help out those interested...I realise this job is not quite as easy as it might sometimes appear - no matter how clear the instructions -  until one has made a good few of them, along with attendant ****-ups lol!! I will do my very best, however, to make it happen...
  
 By the way, I don't know if you've caught the latest good news over at the Feliks-Audio prototype thread, but if not you might find it quite interesting...and sure to have you reaching for the wallet!!


----------



## CITIZENLIN

hypnos1 said:


> Hi JV.
> 
> Glad you found it OK and that you like it...any problems/questions just shout!
> 
> ...



 


hypnos1, 

I would be definitely interested in a pair of C3g's adapters. I can't get enough of C3gs & 6sn7 set up on LD MK IV. I will come and help out with your dishes, gardening.


----------



## JazzVinyl

Hello hypnos1...
  
 Appreciate the perm adapter effort!  Can't wait to see what you can do!!
  
 I used to own the Mister-X built PPA v2 with the variable bass boost option.  And it was a very very nice amp!
  
 But I sold it in favor of the LD MK IV, and I must say....that switching tubes and hearing the different sound signatures has been WAY MORE FUN than the SS amp!  Yeah for us!
  
 And, yes, been watching the Felikis-Audio project and the chatter on the new amp....and I am curious...
  
 If the C3g is as good as everyone says...why was it not chosen as the driver tubes...instead of the 6SN7?  Availability/variety of the many 6SN7's, maybe?
  
 I would also love to be able to compare the tricked out LD MK IV with the C3g drivers and 6AS7 as power tubes...to the new Felikis offering... 
  
 That will be the MOST fun you have, with your pants on  
  
  
 Quote:


hypnos1 said:


> Hi JV.
> 
> Glad you found it OK and that you like it...any problems/questions just shout!
> 
> ...


----------



## hypnos1

citizenlin said:


> hypnos1 said:
> 
> 
> > Hi JV.
> ...


 
  
 Will do my best...dishes, gardening? - wish that were all I have to fit in lol!! But thanks for the offer anyway..
	

	
	
		
		

		
		
	


	



  


jazzvinyl said:


>


 
  
 Hi again JV.
  
 With all this encouragement, how can I _not_ make the time to do it, lol?!
  
 As for C3g drivers in the 'Elise'...didn't even mention it to them - the cost would have driven them right off the project, I'm afraid! But you've got it...LOTS of love for the 6SN7; LOTS of varieties/personal preferences, and still plenty of good old (NOS or cheaper used) tubes out there, let alone newer versions. My hope is that with a pair of good 6SN7s in this beauty it will at least match a MUCH-modded LD MKIII/IV/SE (with C3gs or 5687s and 6AS7G/6080s), and very probably surpass it (the entire component/build quality will, I am sure, be a good bit beyond even the MK9) - all without the need for the downside of various mods. And then there's the LOOKS...'classy' doesn't begin to do it justice, IMHO...


----------



## CITIZENLIN

hypnos1 said:


> Will do my best...dishes, gardening? - wish that were all I have to fit in lol!! But thanks for the offer anyway..
> 
> 
> 
> ...



 


hypnos1 said:


> Will do my best...dishes, gardening? - wish that were all I have to fit in lol!! But thanks for the offer anyway..
> 
> 
> 
> ...



 


Thanks hypnos1
I've been reading Elise thread last couple of days. Can't wait to hear one.


----------



## superdux

So the tubes have finally arrived, but damn...one of my adapters has failed me suddenly!I tested 4 tubes and they all were running so i'll be sending during next week as we have a german holiday on friday.I'll let you guys know when i've sent them in a PM.


----------



## CITIZENLIN

superdux said:


> So the tubes have finally arrived, but damn...one of my adapters has failed me suddenly!I tested 4 tubes and they all were running so i'll be sending during next week as we have a german holiday on friday.I'll let you guys know when i've sent them in a PM.



 

superdux,

Looks like a lot of work, thank you for hooking us up with deals. I hope you enjoy your holiday weekend. Thank you


----------



## hypnos1

superdux said:


> So the tubes have finally arrived, but damn...one of my adapters has failed me suddenly!I tested 4 tubes and they all were running so i'll be sending during next week as we have a german holiday on friday.I'll let you guys know when i've sent them in a PM.


 
  
 Ye Gods, superdux...you've got the Holy Grail there - 'S's AND those boxes look NOS to me! You got them for 10 Euros each?...I'm gonna shoot myself, lol!!  
  
 WELL DONE!


----------



## MIKELAP

superdux said:


> So the tubes have finally arrived, but damn...one of my adapters has failed me suddenly!I tested 4 tubes and they all were running so i'll be sending during next week as we have a german holiday on friday.I'll let you guys know when i've sent them in a PM.


 
 Good for you, a break once in a while doesnt hurt .


----------



## i luvmusic 2

It's here........finally i can have SEX.


----------



## superdux

@hypnos1 there was a certain risk with this deal and i would have had to fix it if it would have went wrong but i phoned the guy and he seemed trustworthy, but you never know when you transfer money, you might not get it back.BTW i might order some more in the next few months, if you guys are satisfied with the tubes.

As for my broken C3G adapter i have to recommend the chinese ebay seller "happydiy998" once again for being so kind and sending me a new adapter even though i haven't sent the faulty one yet. This is a great dealer and its a great pleasure to do business with them!I can only speak in the highest tone of them! They also sell the 5687 to 6N6 6N1，6N2，6N6，6N11，ECC88，E88CC Vacuum tube adapter socket converter.


----------



## MIKELAP

superdux said:


> @hypnos1 there was a certain risk with this deal and i would have had to fix it if it would have went wrong but i phoned the guy and he seemed trustworthy, but you never know when you transfer money, you might not get it back.BTW i might order some more in the next few months, if you guys are satisfied with the tubes.
> 
> As for my broken C3G adapter i have to recommend the chinese ebay seller "happydiy998" once again for being so kind and sending me a new adapter even though i haven't sent the faulty one yet. This is a great dealer and its a great pleasure to do business with them!I can only speak in the highest tone of them! They also sell the 5687 to 6N6 6N1，6N2，6N6，6N11，ECC88，E88CC Vacuum tube adapter socket converter.


 
 Have delt with him also adapter not always reliable but its true he's always ready to replace them.


----------



## gibosi

More tubes...
  
 Managed to purchase 11 of 7044's for less than $4 each. lol  So in addition to the Sylvania I purchased earlier, I now have 3 GE's, 4 Sylvania's, 3 RCA's and 1 Raytheon. From their construction, it appears that none of these tubes are rebrands. Will be testing and burning them in over the weekend....
  


Spoiler: Sylvania 7044


----------



## gibosi

And an interesting 6SN7:
  
 Recently, I have noticed a number of these Tung-Sol 6SN7GT's with black glass, square top mica and flat black plates on eBay, and the other day, I stumbled across one listed as a "Mouse Ear" for $22 BIN.
  
 This is a totally different tube than the coveted 6SN7GT/VT-231 with black glass, round or oval top mica and round plates (BGRP). In my experience, this is much more rare. But of course, being rare does not necessarily mean that it sounds good. And I have yet to find any information about this tube. There is no date. So while it definitely looks like the 1940's, I don't know if it was manufactured before, along side, or after the BGRP's. And I have no idea how this tubes sounds, especially in comparison to the BGRP.  So I really don't know what I have.... But for $22, I couldn't resist. lol


----------



## JazzVinyl

Looking forward to a listening impression, of this one, gibosi..
  
 Quote:


> Originally Posted by *gibosi* /img/forum/go_quote.gif
> 
> And an interesting 6SN7:
> Recently, I have noticed a number of these Tung-Sol 6SN7GT's with black glass, square top mica and flat black plates on eBay, and the other day, I stumbled across one listed as a "Mouse Ear" for $22 BIN.


----------



## gibosi

Too many tubes... not enough time...  but slowly I plod along... lol 
  
 After having spent a bit more time with the 1960's era 6N5P and 6N1P-E, with triple micas and flat plates, I have begun to notice that vocals and horns, especially, have a certain raspiness, similar to the the Russian 6N16B-VR sub-miniature. And over time, I find that I just don't want to listen to these tubes anymore. In my opinion any Voskhod 6N23P from the 1970's is smoother and more musical. So my recommendation is to pass on these. There are lots of better tubes out there....


----------



## Johnnysound

gibosi said:


> And an interesting 6SN7:
> 
> Recently, I have noticed a number of these Tung-Sol 6SN7GT's with black glass, square top mica and flat black plates on eBay, and the other day, I stumbled across one listed as a "Mouse Ear" for $22 BIN.
> 
> This is a totally different tube than the coveted 6SN7GT/VT-231 with black glass, round or oval top mica and round plates (BGRP). In my experience, this is much more rare. But of course, being rare does not necessarily mean that it sounds good. And I have yet to find any information about this tube. There is no date. So while it definitely looks like the 1940's, I don't know if it was manufactured before, along side, or after the BGRP's. And I have no idea how this tubes sounds, especially in comparison to the BGRP.  So I really don't know what I have.... But for $22, I couldn't resist. lol


 
 Hi Gibosi,  out of curiosity, I did a little research on this one and you got a very interesting  6SN7 indeed, extremely rare,  as you said, much more than the famous "mouse ears".  It is  of course a military JAN-CTL,  all indicates is  early 1940´s,  and I almost could bet that this one belongs to one of the very first series produced by Tung-Sol at the beginning of WW2.  I leave this discussion to the experts, but what I have learned so far is that the 6SN7GT with flat black parallel plates,  the characteristic three-step "ladder" and bottom getter was an RCA patent at the time, a good and proven design, and that the military needed 6SN7s  by the thousands, because it was used for radar and many other applications.  I assume that the other US manufacturers (including Tung-Sol) produced  this "RCA style"  tube to meet the war demand in the very early 1940's, before developing their own designs.  I found two examples of this very rare tube for sale, one for $220 and the other for $295 (¡¡) and that is for a single one... for $22 you got an extraordinary deal... congratulations ¡¡


----------



## gibosi

Thanks for doing the research on this tube. I didn't make the connection that these were "RCA style" plates, but it makes perfect sense. And who knows, maybe Tung-Sol, being a smaller company, purchased these plates directly from RCA in the beginning, in order to meet the tremendous surge in demand as the war effort ramped up. Apparently, sometime after that, Tung-Sol replaced the flat RCA-style plates with round plates, which can also be found in Tung-Sol's version of the 6SN7's younger sibling, the 6SL7.
  
 And yes, I noticed that these tubes were going for more than $200 a piece, so of course, when I saw this one for $22, I pounced on it. Very lucky.


----------



## hypnos1

Just a few words to those considering the C3g driver...a while back I was comparing them with my TS 5687s (admittedly not the very earliest ones, but I do believe they indicate a certain 'house' sound), and I intimated that they might not be _quite_ so "in the thick of the action" as the 5687...well, after a 2-week break from ear-bashing and with some new pieces of music as well as old favourites to help resume my addiction, I realise I was insulting my beloved C3GSs - they deliver all the 'action' you could want, and in a way that envelops you such that words cannot really describe fully. It goes beyond meticulous instrument and voice detail/separation/placement/cohesion. It took this short break to remind me of just how well these tubes manage all those feats, and more...the magic was evident the minute (no, _second!_) my HD650s started to fill my head...UTTER BLISS...


----------



## mordy

Hi H 1,
  
 So what do you say - should I just take the plunge and order the expensive adapters, or should I wait and try to make my own? I'm not good with DYI and soldering.....


----------



## JazzVinyl

I, for one, am glad to hear this....because...my adapters for the C3gS's are finally reported to be on USA soil (in San Francisco).  Hope to have them soon.  The C3gS's I bought were reportedly shipped from Germany, days ago, but no tracking info was given.  So I am not sure _when_ they might arrive.
  
 I have a pair of 6SN7's in the house, but those adapters were shipped from China, apparently, dutifully strapped atop a turtle's shell.. as there has been only one tracking update...they passed through some-or-another local China post office, days ago, with not a hint of a word on their whereabouts, since!
  
 But, in the end, after all the waiting, I am hoping the hear the "C3gS UTTER BLISS,  spoken about so often,  by hypnos1
  
 Over and out  (for now)...
  
  
 Quote:


hypnos1 said:


> Just a few words to those considering the C3g driver...a while back I was comparing them with my TS 5687s (admittedly not the very earliest ones, but I do believe they indicate a certain 'house' sound), and I intimated that they might not be _quite_ so "in the thick of the action" as the 5687...well, after a 2-week break from ear-bashing and with some new pieces of music as well as old favourites to help resume my addiction, I realise I was insulting my beloved C3GSs - they deliver all the 'action' you could want, and in a way that envelops you such that words cannot really describe fully. It goes beyond meticulous instrument and voice detail/separation/placement/cohesion. It took this short break to remind me of just how well these tubes manage all those feats, and more...the magic was evident the minute (no, _second!_) my HD650s started to fill my head...UTTER BLISS...


----------



## bbmiller

2014 CanJam @ RMAF (October 10-12, 2014): The CanJam exhibitor list has been finalized Quote:


> Buy your plane ticket. (Or plan your drive, if you're driving.) Book your hotel room (*click here* for info on the hotel and other nearby hotels). Get your ears ready. We've finalized the list of exhibitors at 2014 CanJam @ Rocky Mountain Audio Fest, and here they are (in alphabetical order):
> 
> 
> 
> ...


 
 Hi - I probably have asked many to many questions on this forum for a person who didn't intend roll vacuum tubes on my little dot IV MK tube amp until I got a chance to hear other amps and understand more fully what you all are talking about when you say things like I was able to hear even more layers particularly in the base. I did appreciate your honest answers and beg your indulgence a little more.
  
  
 So the Rocky mountain audio show is finally almost here in my Denver Colorado USA area and next week I intend to be there with my beloved Sennheiser HD 600 headphones and a thumb drive with my favorite tracks as well as a CD with the same.
  
  
 So what is your advice as far as experiencing what you are talking about when you say I heard many more layers with that combination of tubes especially in the base? I have quoted the exhibit a list for headphone related exhibitors in the quote above. Do any of you have any idea if any of the tubes rolled in this tube rolling Fred will be available for listening in the above exhibit a list of tube amp exhibitors. If not do you have any advice to listen for the equivalent sound from other combinations of tubes available from the above exhibitors.
  
  
 I am also wondering since vacuum tube amplifiers can be as expensive as several thousand dollars do any of you think there is something about driving my beloved Sennheiser HD 600 headphones with tube amps which can't be equaled with solid-state at any price even if I have the opportunity to listen to an amp costing several thousand dollars. If so what do you think are the qualities I might listen for when listing to run of my beloved tracks on a very expensive solid-state amplifier which cannot be duplicated with solid-state? Also any advice on what type of track you would have to listen to. Do you really see tube amps at its best when listing to drums and cymbals or the human voice or brass?


----------



## JazzVinyl

Hello bbmiller...

You say you already have a Little Dot MK IV?

And you seem to be saying your unwilling to Tube Roll with your current MKIV?

And you want advice on hearing layers in the "base"...I assume you mean "bass" notes?

The Sennheiser 600 is well known to be a bit bass shy, you know that, right?

I hope it does NOT take thousands of dollars to make a headphone amp sound really really good.

I have owned a really nice Solid State amp, and I do think the Little Dot MK IV is more "fun" and more 3D than the SS amp was. Also, a tube amp can have it's sonic signature changed via Tube Rolling.

I also have found it difficult in the RMAF type environment, to really evaluate potential amps. It's easy to get caught up in in the spin of the moment instead of being able to quietly evaluate gear in a calm and sedate manner. The Sennheiser 600's are also prone to outside sound interference...which adds to the complexity of the problem.

May I suggest you start tube rolling with the amp you already own and try 6HM5's as drivers. These are inexpensive and may indeed open your eyes/ears to "depth and layers" that tube rollers speak of...

I would do that, before spending thousands...



[quote name="bbmiller"
So what is your advice as far as experiencing what you are talking about when you say I heard many more layers with that combination of tubes especially in the base? I have quoted the exhibit a list for headphone related exhibitors in the quote above. Do any of you have any idea if any of the tubes rolled in this tube rolling Fred will be available for listening in the above exhibit a list of tube amp exhibitors. If not do you have any advice to listen for the equivalent sound from other combinations of tubes available from the above exhibitors.


I am also wondering since vacuum tube amplifiers can be as expensive as several thousand dollars do any of you think there is something about driving my beloved Sennheiser HD 600 headphones with tube amps which can't be equaled with solid-state at any price even if I have the opportunity to listen to an amp costing several thousand dollars. If so what do you think are the qualities I might listen for when listing to run of my beloved tracks on a very expensive solid-state amplifier which cannot be duplicated with solid-state? Also any advice on what type of track you would have to listen to. Do you really see tube amps at its best when listing to drums and cymbals or the human voice or brass?
[/quote]


----------



## bbmiller

> *By *
> JazzVinyl
> 
> 
> ...


 


> by bbmiller
> So what is your advice as far as experiencing what you are talking about when you say I heard many more layers with that combination of tubes especially in the base? I have quoted the exhibit a list for headphone related exhibitors in the quote above. Do any of you have any idea if any of the tubes rolled in this tube rolling Fred will be available for listening in the above exhibit a list of tube amp exhibitors. If not do you have any advice to listen for the equivalent sound from other combinations of tubes available from the above exhibitors.
> 
> 
> I am also wondering since vacuum tube amplifiers can be as expensive as several thousand dollars do any of you think there is something about driving my beloved Sennheiser HD 600 headphones with tube amps which can't be equaled with solid-state at any price even if I have the opportunity to listen to an amp costing several thousand dollars. If so what do you think are the qualities I might listen for when listing to run of my beloved tracks on a very expensive solid-state amplifier which cannot be duplicated with solid-state? Also any advice on what type of track you would have to


 
 Forgive me for the impreciseness of my language. My example of layers in the base was not necessarily anything I ever heard in this thread but a kind of paraphrase of the kinds of things that is said in this thread. Let me also explain that before I got my present headphone set up my best audio listening was with my 40 year old Bose 901 speakers and it 40 year old solid-state amplifier. Even before my present set up was burnt in do any degree at all my present little dot amplifier and HD 600s was blowing the sound quality of my Bose and its 40-year-old amplifier away.
  
 So I am very unsophisticated in my listening experiences to good quality audio and presently have by far the best audio I have ever had with the little dot amplifier and the HD 600 headphones. I actually am enjoying the sound of drums and cymbals from this set up more than I have ever enjoyed the sound of those instruments before so I don't know if I really want to hear more base from my set up, but do want to educate myself as to what you all are talking about. It seems to me you just can't hear things through description unless you could do something like have somebody stand side-by-side by you and tell you that's the sound of that description.
  
 I do not know to what degree I could trust people who are trying to sell you something and an audio show if they say you are about to hear an amplifier that really excels in this way. So how do you think I could use this audio show to educate me to the Max about what's possible in headphone audio.
  
 I am not necessarily totally against getting both the driving tubes and power tubes recommended on this forum as end-stage tubes. I just want to edify myself as to how good audio can get. Perhaps your suggestion of trying 6MH5 drivers is a good one do you think the RCA inexpensive variety of that tube would be a good choice as far as brands go.
  
 I have heard on these head FI forms that if you get a good enough solid-state amplifier you can create all the numerous sound signatures you could desire with an equalizer. Do any of you all believe that to be true?


----------



## MIKELAP

bbmiller said:


> Forgive me for the impreciseness of my language. My example of layers in the base was not necessarily anything I ever heard in this thread but a kind of paraphrase of the kinds of things that is said in this thread. Let me also explain that before I got my present headphone set up my best audio listening was with my 40 year old Bose 901 speakers and it 40 year old solid-state amplifier. Even before my present set up was burnt in do any degree at all my present little dot amplifier and HD 600s was blowing the sound quality of my Bose and its 40-year-old amplifier away.
> 
> So I am very unsophisticated in my listening experiences to good quality audio and presently have by far the best audio I have ever had with the little dot amplifier and the HD 600 headphones. I actually am enjoying the sound of drums and cymbals from this set up more than I have ever enjoyed the sound of those instruments before so I don't know if I really want to hear more base from my set up, but do want to educate myself as to what you all are talking about. It seems to me you just can't hear things through description unless you could do something like have somebody stand side-by-side by you and tell you that's the sound of that description.
> 
> ...


 
 Most everybody here bought the yugoslavian 6HM5 like on this picture and they are cheap i bought 10 tubes comes out to $3.90 U.S. each shipped   heres the link if your interested.Dont have to buy 10 tubes just visit his store              http://www.ebay.com/itm/6HM5-EC900-lot-10-pcs-EI-Yugoslavia-NOS-free-registered-airmail-shipping-/251609948341?ssPageName=ADME:X:RTQ:US:1123                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    
  
       When i went to my audio show in Montreal i listened to many amps and headphones and compared to the gear i have right now the higher end gear wasnt a night and day difference ,changes where very subtle with what i am using now so this is encouraging in a way lol .Now if i could only stop buying tubes  i would cured .


----------



## bbmiller

I am wondering if there is anybody else attending the Rocky Mountain audio Fest, if they would be willing to meet with me there to jointly visit some of the exhibits? You won't have to stick with me all day, but if you can share a few impressions of what you are hearing at a few of the exhibits it would be very edifying for me. As I have explained above my new Sennheiser HD 600s and my little dot IV MK SE is the first new good audio equipment I have had in 40 years. So any impressions from just about any of you all would be appreciated.
  
 I don't know if these audio shows make a circuit and any of you all could share your recent listening experiences listening to this year's circuit of audio exhibits at the various headphone audio shows, but if you could share your thoughts on how a certain exhibit sounded to you and I could visit a sensually the same exhibit in my Metro Denver hometown audio show and compare impressions of the sound that would be appreciated as that could edify me as to what you all are hearing when you say you hear this of that.


----------



## mordy

Hi bbmiller,
  
 It is very difficult to explain in words the difference between average or mediocre equipment compared to very good or superb equipment, and so many variables come into play - your personal equipment and personal preferences, the type of music and type of recordings you listen to etc etc.
  
 What I have learned from this forum is that it is possible to reach a consensus on what is really good sound, no matter what the variables are. (It actually continues to amaze me.)
  
 No if I told you that there is a difference in taste between grape juice and wine, would you agree with me? Most likely you would agree. If I told you that there are differences in taste between wines, you most likely would also agree.
  
 No, if I told you that you could train yourself to taste different wines and pick out a group of the best tasting wines, you may or may not agree. However, if you asked experts on wine testing they would say that this is quite possible. The connoisseurs will tell you what they are looking for and why this wine is better than another wine etc. (Please don't take it that I am in any way an expert; I'm only using this as an example. When it comes to tubes I can only honestly report what I hear without any pretense.)
  
 Now, let's see if we can apply this analogy to Hi-Fi. The average type good solid state equipment to me is like the grape juice - nice, but flat and without character. (I am sure that there is expensive ss equipment that has many of the qualities of good tube equipment.) Continuing the analogy: Good tube equipment is like the wine. Tube rolling is like the wine tasting (!) Some wines taste like kerosene, others are heavenly.
  
 Take a wine bottle and read the label (actual quote): "A crisp semi-dry wine with a slight sweetness and a spicy floral aroma. The wine is prevalent with chocolate and raspberries and a smooth finish with chocolate undertones. It will complement a wide selection of sweet and spicy style foods, and will continue to age gracefully over time."
  
 Translated into audio speak: "This tube combination has a sweet mid range with great musicality, impact and slam in the bass, as well as shimmering highs. These tubes offer great clarity and great detail with a very wide three dimensional sound stage. As the tubes burn in your musical enjoyment will continue to increase over time."
  
 There is a switch on the back of my ss receiver so that I can instantly switch the tube preamp in and out . Once your ear is trained you can instantly pick out when the tube preamp is switched out - the sound becomes flatter and loses it's vitality.
  
 Got my first equalizer in 1974 - a Soundcraftsmen preamp-equalizer. As far as I know, the equalizer can emphasize or de-emphasize certain frequencies and thus compensate for a poor recording, but I cannot see how it can add the timbre, quickness, impact, slam, detail and effervescence that good tubes can add.
  
 About layers: When you listen to good tubes suddenly you hear and become aware of new things in familiar recordings that you did not hear before. You can pinpoint certain instruments that you did notice before, and you can follow that instrument throughout the recording whereas before you only caught a glimpse of it or it was obscured by other instruments in the recording.


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## BGRoberts

I am sure learning a lot from bbmiller's questions and you all's answers. Thanks for all the thought, time, and effort put in to them. 
Really looking forward to the day I can play with the LDIII again! 
BG


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## JazzVinyl

Well said about "Layers" mordy...and I agree, 100%....



mordy said:


> About layers: When you listen to good tubes suddenly you hear and become aware of new things in familiar recordings that you did not hear before. You can pinpoint certain instruments that you did notice before, and you can follow that instrument throughout the recording whereas before you only caught a glimpse of it or it was obscured by other instruments in the recording.


----------



## bbmiller

jazzvinyl said:


> Well said about "Layers" mordy...and I agree, 100%....
> 
> 
> 
> ...


 

 In the above YouTube video clip from the  White House: Fiesta Latina (which I have the complete high quality video television performance of) I can visually see there is a lot of instruments and percussion to reveal, but my present little dot IV MK SE with its stock tubes does not reveal all that I could see visually going on in its sound rendition. Mind you I am using Sennheiser HD 600 headphones which some of you have told me have limits in its ability to reveal the base notes. 
  
 I am wondering if this is exactly the type of music/video clip which some of you can find revealing with your best little dot vacuum tube set up and headphones which I cannot do to the limitations of my present little dot tube set up and headphones. I am further wondering if this would be exactly the type of music/video clip I should take to the Rocky Mountain audio Fest to learn exactly the limitations of my present equipment.
  
 Where I to decide to take this clip to the Rocky mountain audio Fest any ideas in what formats I should take it. Should I take on my flash thumbnail drive as well as a CD and DVD. I mean if you have been to a festival like I will be going to with your own music to test the exhibitors equipment what formats are the exhibitors most likely to accept?


----------



## MIKELAP

bbmiller said:


> In the above YouTube video clip from the  White House: Fiesta Latina (which I have the complete high quality video television performance of) I can visually see there is a lot of instruments and percussion to reveal, but my present little dot IV MK SE with its stock tubes does not reveal all that I could see visually going on in its sound rendition. Mind you I am using Sennheiser HD 600 headphones which some of you have told me have limits in its ability to reveal the base notes.
> 
> I am wondering if this is exactly the type of music/video clip which some of you can find revealing with your best little dot vacuum tube set up and headphones which I cannot do to the limitations of my present little dot tube set up and headphones. I am further wondering if this would be exactly the type of music/video clip I should take to the Rocky Mountain audio Fest to learn exactly the limitations of my present equipment.
> 
> Where I to decide to take this clip to the Rocky mountain audio Fest any ideas in what formats I should take it. Should I take on my flash thumbnail drive as well as a CD and DVD. I mean if you have been to a festival like I will be going to with your own music to test the exhibitors equipment what formats are the exhibitors most likely to accept?




 Dont know about you guys but over here they all have there own setup  and its mostly on a laptop and different HP to try out, but you could always bring your HP and a favorite CD and maybe you could try out your stuff.and get a good idea .


----------



## mordy

Hi bb,
  
 This clip may be HD video, but soundwise it is not HD. As an example, at the 2 min mark the male drummer hits the cymbal and you can barely hear it. I would take along familiar recordings that you consider very well recorded and bring those. Then you have a frame of reference to compare with.
  
 Now, a set-up with very good tubes will bring out much more resolution in _ANY_ non-compressed recording. Think of a regular point-and-shoot camera and a very high quality SLR camera - the same picture taken by the better camera will be much sharper, and the sharpness will be there even when you magnify the picture many times. Both pictures may be pleasing, but once you know what to look for, you will prefer the better quality picture.
  
 Truth is that YouTube may not do justice to the sound quality of the original recording due to electronic processing and compression etc. ....What you hear at home with a high resolution CD etc may be very different than hearing the same recording on YouTube, and I don't think that a good tube amp will bring out what was omitted from the recording through compression.


----------



## Acapella11

Dear bb,
  
 It is always a good idea to go to a meet. You widen your horizon a lot in terms of gear and you can talk to people who's gear you like. And it is also good to take your headphones with you and you could put some tracks you are used to on a USB-stick or CD, as often a laptop is used for playback.
  
 Mordy, really did an effort answering, quite impressed. But as Mikelap suggested, it certainly is a good idea to get these 6HM5. Words can only say _so_ much and you really don't have to be afraid trying them. You will understand whilst listen to different tubes. Also, these are inexpensive but revealing.


----------



## Rossliew

Have recently been listening with my newly arrived Tung Sol mouse ear 6SN7 with Western Electric WE403A as drivers - WOW! What a great combo in my system - prominent mids and thumping, beats-heavy bass. Highs are present but not overly so, just enough to give a sense of space and airiness between instruments to make it sound holographic.


----------



## Uncle AL

rossliew said:


> Have recently been listening with my newly arrived Tung Sol mouse ear 6SN7 with Western Electric WE403A as drivers - WOW! What a great combo in my system - prominent mids and thumping, beats-heavy bass. Highs are present but not overly so, just enough to give a sense of space and airiness between instruments to make it sound holographic.


 
 Are you using your HD555s with this combo?


----------



## Rossliew

uncle al said:


> Are you using your HD555s with this combo?


 
 No, with the HD600. Now that you mentioned it, i will try it with the HD555 tonight. But since its a low impedance headphone, not too sure about the synergy with my LD Mk 3 OTL..


----------



## gibosi

rossliew said:


> Have recently been listening with my newly arrived Tung Sol mouse ear 6SN7 with Western Electric WE403A as drivers - WOW! What a great combo in my system - prominent mids and thumping, beats-heavy bass. Highs are present but not overly so, just enough to give a sense of space and airiness between instruments to make it sound holographic.


 
  
 I had a hunch that mouse ears would be good power tubes in the LD. It is always good when a hunch turns pans out!


----------



## Uncle AL

rossliew said:


> No, with the HD600. Now that you mentioned it, i will try it with the HD555 tonight. But since its a low impedance headphone, not too sure about the synergy with my LD Mk 3 OTL..


 
 Your right.. synergy of LD MK 3 with HD555s would not be as good as HD600s with MK3.  Amplifier power output is 100 mW with HD555s and 3x that amount, 350 mW, at LD MK3 setting for your HD600s.  While you're not going to use all of that power, it will be noticed in overal audio quality.  Please remember, before you change between the HD600s and HD555s, you will need to change the DIP switch settings, inside window on underside of the MK3 amp.  I'm sure you're aware of it, but correct setting for your HD600s is "ON", "ON" for each of the two channels, and "OFF", "OFF" for the HD555s.  Hope this helps--


----------



## Rossliew

gibosi said:


> I had a hunch that mouse ears would be good power tubes in the LD. It is always good when a hunch turns pans out!


 
  
 You're right, G! Now, if only I can find those CTL 6SN7s you mentioned earlier to try out 
  


uncle al said:


> Your right.. synergy of LD MK 3 with HD555s would not be as good as HD600s with MK3.  Amplifier power output is 100 mW with HD555s and 3x that amount, 350 mW, at LD MK3 setting for your HD600s.  While you're not going to use all of that power, it will be noticed in overal audio quality.  Please remember, before you change between the HD600s and HD555s, you will need to change the DIP switch settings, inside window on underside of the MK3 amp.  I'm sure you're aware of it, but correct setting for your HD600s is "ON", "ON" for each of the two channels, and "OFF", "OFF" for the HD555s.  Hope this helps--


 
  
 I'm too lazy to keep switching the dip settings so i just leave them where they are LOL..who knows, I might be hardworking tonight..


----------



## Uncle AL

rossliew said:


> You're right, G! Now, if only I can find those CTL 6SN7s you mentioned earlier to try out
> 
> 
> I'm too lazy to keep switching the dip settings so i just leave them where they are LOL..who knows, I might be hardworking tonight..


 
 If so, you can hit happy-medium and have one switch "OFF" and one switch "ON", which is for medium impedence.  This would be fair at best for either headphone, but at least it would not require you to change back-and-forth between "OFF", "OFF" and "ON", "ON".  That being said, you will gain a huge amount in sound quality by matching the DIP switch settings to each set of cans... and, you may extend life of the tubes, because they would be balanced to the impedence of the headphones.
  
 If it was me, I would set DIP switches to level for main headphones you plan on using the most, in this case, the HD600s.  I have the LD MK 4 SE, and am using HD650 phones with it, and the sound is AWESOME... great synergy.  Your HD600s, should be almost identical in quality, if you set DIP switches, "ON", "ON" for each channel.


----------



## Rossliew

uncle al said:


> If so, you can hit happy-medium and have one switch "OFF" and one switch "ON", which is for medium impedence.  This would be fair at best for either headphone, but at least it would not require you to change back-and-forth between "OFF", "OFF" and "ON", "ON".  That being said, you will gain a huge amount in sound quality by matching the DIP switch settings to each set of cans... and, you may extend life of the tubes, because they would be balanced to the impedence of the headphones.
> 
> If it was me, I would set DIP switches to level for main headphones you plan on using the most, in this case, the HD600s.  I have the LD MK 4 SE, and am using HD650 phones with it, and the sound is AWESOME... great synergy.  Your HD600s, should be almost identical in quality, if you set DIP switches, "ON", "ON" for each channel.


 
 Noted with thanks, @Uncle AL! 
  
 Btw, what's the difference between the Mk 4 and the 3? Have always been curious about this since both are OTL (am i right??)


----------



## Uncle AL

gibosi said:


> I had a hunch that mouse ears would be good power tubes in the LD. It is always good when a hunch turns pans out!


 
 Mouse Ears 6SN7 are great but won't fit LD MK3.  I believe they will fit LD MKVIII.  The LD MK IV SE is supplied with M8100 / C4010 and EH 6H30Pi gold pin tubes, and same combo is great in MK3, especially with HD600 cans.  It'll put a smile on your face, for sure--


----------



## gibosi

uncle al said:


> Mouse Ears 6SN7 are great but won't fit LD MK3.  I believe they will fit LD MKVIII.  The LD MK IV SE is supplied with M8100 / C4010 and EH 6H30Pi gold pin tubes, and same combo is great in MK3, especially with HD600 cans.  It'll put a smile on your face, for sure--


 
  
 With adapters the 6SN7 can be used in place of the 6H30Pi in LD amps.....


----------



## Uncle AL

rossliew said:


> Noted with thanks, @Uncle AL!
> 
> Btw, what's the difference between the Mk 4 and the 3? Have always been curious about this since both are OTL (am i right??)


 
 The MK 4 has upgraded electronic parts, transformers, capacitors, etc.  Then there's a huge difference when you bump up the the MK IV SE.  They go all-out with best possible parts, and then they spec this amp with the M8100 and Electro Harmonix 6H30PI Gold Pin tubes.  If you check other Little Dot threads and reviews, this is one of the best possible combos.  The MK 3 would benefit from these tubes as well.  If you check, you can find Mullard M8100 matched pair tubes for around $39, and around $100 for the 6H30PI tubes.
  
 One other odd difference between the MK3 and MK4, is that the MK3 runs much, much hotter with average temp around 100 deg.  The MK4 is cooler, and the MK 4 SE is MUCH cooler, due in-part to the funky-looking gold tube cages.  It does help disipate heat, and a cooler amp, is a happer amp


----------



## Uncle AL

gibosi said:


> With adapters the 6SN7 can be used in place of the 6H30Pi in LD amps.....


 
 Hmm.. yes, correct.  Only problem is that would open a whole new world to tube rolling.
 "So many tubes, so little time!"


----------



## mordy

Hi Uncle Al,
  
 The mouse ear tubes as well as all 6SN7 - 6AS7 - 6080 tubes _will_ fit the LD MKIII with a 9pin extender that raises the adapter above the decorative ring around the tube socket. The 6SL7 - 6SN7 only need the adapters with extenders, but the 6AS7/6080 tubes also need an external power supply.
  
 Here is a link to the 9pin socket extenders:
  
 http://www.ebay.com/itm/4pc-9PIN-Bakelite-vaccum-TUBE-SOCKET-SAVER-base-FOR-12AX7-12AU7-ECC82-ECC83-amps-/151433025896?pt=Vintage_Electronics_R2&hash=item23421c9968


----------



## gibosi

uncle al said:


> Hmm.. yes, correct.  Only problem is that would open a whole new world to tube rolling.
> "So many tubes, so little time!"


 
  
 With all due respect, it appears that you have not read the last several hundred pages of this thread. A number of us are indeed running 6SN7's, and even 6AS7's, as power tube in the LD. And perhaps more surprisingly, a number of us are using 6SN7's, 6DJ8's and other medium mu double triodes as drivers. So yes indeed, tube rolling is very much alive and well here.
  
 Cheers!


----------



## Uncle AL

Have not rolled tubes other than E95, E92 and E91 class tubes.  Modding for  6SN7, 6AS7, 6DJ8 "would open up a whole new world", as I acknowledged prior to comment.


----------



## Rossliew

@Uncle AL, it is a world worth opening and exploring


----------



## Rossliew

Guys, would it be possible to use the 6DJ8/ECC88/6922 family of tubes as driver tubes in the Mk 3? Voltage requirements are the same as the 6AK5 but with higher current draw..


----------



## gibosi

rossliew said:


> Guys, would it be possible to use the 6DJ8/ECC88/6922 family of tubes as driver tubes in the Mk 3? Voltage requirements are the same as the 6AK5 but with higher current draw..


 
  
 The current draw of these tubes is about the same as the EF91, so no problem at all with respect to heaters. But of course, you will still need to use an external 9-pin breadboard socket.


----------



## MIKELAP

rossliew said:


> Guys, would it be possible to use the 6DJ8/ECC88/6922 family of tubes as driver tubes in the Mk 3? Voltage requirements are the same as the 6AK5 but with higher current draw..


 
      With these adapters you can run a 6DJ8  a 6SL7 OCTAL , AND12AX7  tube you can also use breadboards and power supplies for even more choices   PAGE 267 post# 3998
 shows you the tubes you can use preferably below .40 A   and schematics page 300 post#4493. For the breadboards setup you could use the search function also  mordy and gibosi know alot more than me on this subject . Have fun .


----------



## gibosi

uncle al said:


> Have not rolled tubes other than E95, E92 and E91 class tubes.  Modding for  6SN7, 6AS7, 6DJ8 "would open up a whole new world", as I acknowledged prior to comment.


 
  
 On the chance that you might be interested, this posting will give you an idea how we are modding our LD's to run these tubes as drivers:
  
 http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/5760#post_10435226


----------



## Rossliew

Thanks both @MIKELAP and @gibosi ! Shall re-look the older postings on breadboards since I'm running out of simple plug and play tube types to roll hehe..


----------



## TrollDragon

Yes a nice little adapter will allow you 6DJ8, 6922 or 6Н23П-ЕВ... even Octals...


----------



## TrollDragon

uncle al said:


> The MK 4 has upgraded electronic parts, transformers, capacitors, etc.  Then there's a huge difference when you bump up the the MK IV SE.  *They go all-out with best possible parts, and then they spec this amp with the M8100 and Electro Harmonix 6H30PI Gold Pin tubes.  If you check other Little Dot threads and reviews, this is one of the best possible combos.*  The MK 3 would benefit from these tubes as well.  If you check, you can find Mullard M8100 matched pair tubes for around $39, and around $100 for the 6H30PI tubes.
> 
> One other odd difference between the MK3 and MK4, is that the MK3 runs much, much hotter with average temp around 100 deg.  The MK4 is cooler, and the MK 4 SE is MUCH cooler, *due in-part to the funky-looking gold tube cages.*  It does help disipate heat, and a cooler amp, is a happer amp


 
  
 For those that are new to the Little Dot or very uninformed, the stock M8100's are the furthest thing from optimal or even the best. Many have come here stating that they just bought an $80+ pair of 8100's or some other so called exotic 6AK5 for a gross amount of money. (From the likes of Yew Audio etc...) Then they install in a pair of Yugo 6HM5's and are totally blow away by a $7 tube sounding head and tails above the so called Cryo'ed, Matched Pair they thought MUST be good. 
  
  
 The aesthetic rings have absolutely nothing to do with keeping the amplifier cool, 99% of the heat is generated internally from the resistors on the PCB.


----------



## hypnos1

trolldragon said:


> For those that are new to the Little Dot or very uninformed, the stock M8100's are the furthest thing from optimal or even the best. Many have come here stating that they just bought an $80+ pair of 8100's or some other so called exotic 6AK5 for a gross amount of money. (From the likes of Yew Audio etc...) Then they install in a pair of Yugo 6HM5's and are totally blow away by a $7 tube sounding head and tails above the so called Cryo'ed, Matched Pair they thought MUST be good.
> 
> 
> The aesthetic rings have absolutely nothing to do with keeping the amplifier cool, 99% of the heat is generated internally from the resistors on the PCB.


 
  
 Right on, TD...I got _my_ Ei ('Yugo') 6HM5s for FIVE dollars a piece - best straight plug 'n play (on EF95 setting) out there, to be sure.
  
 I suppose one might conjecture that the brass plate would conduct a certain amount of case heat to the posts, thence to the rings...but I must admit I never noticed much heat on 'em!!
  
 With mine off, and 2 high-gain C3GSs driving 2 6AS7G powers, the case never gets overly hot (36C after 4 hrs, if I remember correctly!)...so yes, UncleAL, the MKIV SE _is_ very good at dissipating heat, lol...


----------



## mordy

Possibly the posts around the tubes are there to protect your fingers from getting a burn in addition to aesthetics. With two 6080 tubes and fan cooling my case does not exceed 32C (89F) even though you could sustain a burn from touching the power tubes.
  
 Even though the MKIV supposedly uses better components, I have never heard anybody say that it sounds better than the MKIII. David Zhe Zhe calls the MKIII the sweet spot of his line of amps.


----------



## Rossliew

Dear tube gurus!
  
 I note that the Schiit Valhalla uses a similar tube type (6N6P) with the LD Mk 3 as power tubes . Going along a similar line of reasoning, would it be safe and possible to use our 6SN7 adapters and run 6SN7s as power tubes for the Valhalla?


----------



## TrollDragon

rossliew said:


> Dear tube gurus!
> 
> I note that the Schiit Valhalla uses a similar tube type (6N6P) with the LD Mk 3 as power tubes . Going along a similar line of reasoning, would it be safe and possible to use our 6SN7 adapters and run 6SN7s as power tubes for the Valhalla?


 

 I think the Schiit gear has a lot tighter tolerances as to what tubes you can use and which ones you can't.


----------



## TrollDragon

Well I received a MOST EXCELLENT gift today, four Yugoslavians came to live here in Nova Scotia!

  
  
 Running 6GU7's as power tubes in this setup and these little Yugo's sound incredible!

  
 The DBV3 T50RP's with Metallica's Welcome Home is a perfect fitting tune for these little guys!

 The YouTube quality doesn't do the song justice, seek this out in CD as it's one of the best.
  
 Much Thanks!


----------



## Rossliew

trolldragon said:


> I think the Schiit gear has a lot tighter tolerances as to what tubes you can use and which ones you can't.


 
  
 Ahh..that's unfortunate but thanks for that.


trolldragon said:


> Well I received a MOST EXCELLENT gift today, four Yugoslavians came to live here in Nova Scotia!
> 
> 
> 
> ...




  
 Congrats on the 6HM5s! You will not be disappointed!
  
 Btw, are the 6GU7s plug and play? I believe they are 9-pin tubes so would an adapter be required?


----------



## TrollDragon

rossliew said:


> Ahh..that's unfortunate but thanks for that.
> 
> Congrats on the 6HM5s! You will not be disappointed!
> 
> Btw, are the 6GU7s plug and play? I believe they are 9-pin tubes so would an adapter be required?


 
 You might want to check in the Schiit threads but I have never seen any Valhalla's with adapted 6SN7 on them. The Valhalla might be easier to modify than the LD for heater current and bias mod's considering it's case design, but I don't have one to tinker with.
  
 Thanks on the 6HM5's, I'm really liking the sound so far and yes the 6GU7's are plug and play as output tubes.


----------



## Rossliew

trolldragon said:


> You might want to check in the Schiit threads but I have never seen any Valhalla's with adapted 6SN7 on them. The Valhalla might be easier to modify than the LD for heater current and bias mod's considering it's case design, but I don't have one to tinker with.
> 
> Thanks on the 6HM5's, I'm really liking the sound so far and yes the 6GU7's are plug and play as output tubes.


 
  
 I might just drop a mail to the techies at Schiit and see if any positive reply is forthcoming 
  
 Time to check out some 6GU7s!  how would you describe their sound vis-a-vis the 6SN7s?


----------



## TrollDragon

rossliew said:


> I might just drop a mail to the techies at Schiit and see if any positive reply is forthcoming
> 
> Time to check out some 6GU7s!  how would you describe their sound vis-a-vis the 6SN7s?


 

 I don't run any 6SN7's at all as I never jumped on the bandwagon, since the average price of them ramped up very quickly. The 6GU7's are a tad warmer than the 6H30Pi's but as far as I understand, the 9 pin output's only make a very subtle change to the sound unlike using octal as outputs.
  
 There is a eBay Make an Offer on 3 of them but the shipping would be more than the tubes.


----------



## Rossliew

trolldragon said:


> I don't run any 6SN7's at all as I never jumped on the bandwagon, since the average price of them ramped up very quickly. The 6GU7's are a tad warmer than the 6H30Pi's but as far as I understand, the 9 pin output's only make a very subtle change to the sound unlike using octal as outputs.
> 
> There is a eBay Make an Offer on 3 of them but the shipping would be more than the tubes.


 
 Yeah, these 6GU7s are pretty affordable in price (and hope they remain so for the foreseeable future!). I saw that ad as well but have identified a few other sellers with more reasonable shipping prices LOL.


----------



## Uncle AL

gibosi said:


> On the chance that you might be interested, this posting will give you an idea how we are modding our LD's to run these tubes as drivers:
> 
> http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/5760#post_10435226




VERY interested.. Thanks gibosi! You realize, of course that this creates a monster of interest in exploring modding and new tube combinations!


----------



## hypnos1

uncle al said:


> VERY interested.. Thanks gibosi! You realize, of course that this creates a monster of interest in exploring modding and new tube combinations!


 
  
 Welcome to our INSANE world, Uncle AL!!..


----------



## gibosi

uncle al said:


> VERY interested.. Thanks gibosi! You realize, of course that this creates a monster of interest in exploring modding and new tube combinations!


 
  
 Yes, I realize this...lol...  I have something over 700 tubes as a result of this insanity, and more on the way..... And you should count yourself lucky in that you can skip all the pentodes and heptodes we went through before finally getting to double triodes. Most of my 700 plus tubes are in a pile labeled "not good enough!". lol  
  
 Enjoy! .


----------



## hypnos1

gibosi said:


> Yes, I realize this...lol...  I have something over 700 tubes as a result of this insanity, and more on the way..... And you should count yourself lucky in that you can skip all the pentodes and heptodes we went through before finally getting to double triodes. Most of my 700 plus tubes are in a pile labeled "not good enough!". lol
> 
> Enjoy! .


 
  
 700+, g?...What a fabulous wall-hanging those could make, lol - all hooked up to the mains, of course!!


----------



## TrollDragon

gibosi said:


> Yes, I realize this...lol...  I have something over 700 tubes as a result of this insanity, and more on the way..... And you should count yourself lucky in that you can *skip all the pentodes and heptodes we went through before finally getting to double triodes.* Most of my 700 plus tubes are in a pile labeled "not good enough!". lol
> 
> Enjoy! .


 
  
 The Pentode/Heptode days were some of the most enjoyable, active and innovative times in this thread.


----------



## hypnos1

trolldragon said:


> The Pentode/Heptode days were some of the most enjoyable, active and innovative times in this thread.


 
  
 Yep, TD - "Those were the days my friend"...great song, that!!...
	

	
	
		
		

		
		
	


	



  
 But haven't we come a _long_ way, too...


----------



## Rossliew

Anyone knows what is the rail voltage in our LD Mk 3? Am trying to see if the 6SN7 tubes we use are suitable for the Valhalla 2 as well. Schiit tech says its possible but the Valhalla's rail voltage of 200V is not ideal (seems the 6SN7s require 400V). 
  
 Can anyone help confirm if you know? Thanks!


----------



## mab1376

rossliew said:


> Anyone knows what is the rail voltage in our LD Mk 3? Am trying to see if the 6SN7 tubes we use are suitable for the Valhalla 2 as well. Schiit tech says its possible but the Valhalla's rail voltage of 200V is not ideal (seems the 6SN7s require 400V).
> 
> Can anyone help confirm if you know? Thanks!


 
  
 What about 6SL7?


----------



## TrollDragon

rossliew said:


> Anyone knows what is the rail voltage in our LD Mk 3? Am trying to see if the 6SN7 tubes we use are suitable for the Valhalla 2 as well. Schiit tech says its possible but the Valhalla's rail voltage of 200V is not ideal (seems the 6SN7s require 400V).
> 
> Can anyone help confirm if you know? Thanks!


 
 The B+ on the LD III & IV is around 200V as well, I have not measured it specifically but all the filter caps are rated at 250V so it would not be higher or even within a few volts of that.
  
 The transformer output is AC 175,  multiply by sqrt(2) to convert from RMS and that gives you approximately 247 VDC out of the full wave bridge, subtract the voltage drop from the the filtering resistors and caps you are left with a usable 200VDC


----------



## Acapella11

Quote:


> Originally Posted by *Rossliew*
> 
> 
> I might just drop a mail to the techies at Schiit and see if any positive reply is forthcoming
> Time to check out some 6GU7s!  how would you describe their sound vis-a-vis the 6SN7s?


  
 Quote:


trolldragon said:


> I don't run any 6SN7's at all as I never jumped on the bandwagon, since the average price of them ramped up very quickly. The 6GU7's are a tad warmer than the 6H30Pi's but as far as I understand, the 9 pin output's only make a very subtle change to the sound unlike using octal as outputs.
> There is a eBay Make an Offer on 3 of them but the shipping would be more than the tubes.


 
  
 Thanks for mentioning the 6GU7s. It is compatible with the 6FQ7 also. Just found this:
 "The 6CG7 is just a noval version of the 6SN7."
  
 Here: http://www.ebay.com/itm/1-x-NEW-RCA-6CG7-6FQ7-tubes-NIB-NOS-red-Cavali-pair-matched-in-HICKOK-TV7-D-/151410436089?pt=Vintage_Electronics_R2&hash=item2340c3e7f9
 The same tubes are also offered in ebay.de
  


> The Pentode/Heptode days were some of the most enjoyable, active and innovative times in this thread.


 


> Originally Posted by *hypnos1* /img/forum/go_quote.gif
> Yep, TD - "Those were the days my friend"...great song, that!!...
> 
> 
> ...


 
  
 Enjoyed them a lot


----------



## hypnos1

acapella11 said:


> Thanks for mentioning the 6GU7s. It is compatible with the 6FQ7 also. Just found this:
> "The 6CG7 is just a noval version of the 6SN7."
> 
> Here: http://www.ebay.com/itm/1-x-NEW-RCA-6CG7-6FQ7-tubes-NIB-NOS-red-Cavali-pair-matched-in-HICKOK-TV7-D-/151410436089?pt=Vintage_Electronics_R2&hash=item2340c3e7f9
> ...


 
  
 Now I'm getting _really_ nostalgic, A11!..And I suspect there are a good few more recent members who don't realise the tremendous contributions you (and the long-lost Audiofanboy) made to this thread...we probably would not be at the current dizzy heights if it weren't for you guys...'Hall of Fame' should you both grace, lol!


----------



## Acapella11

hypnos1 said:


> Now I'm getting _really_ nostalgic, A11!..And I suspect there are a good few more recent members who don't realise the tremendous contributions you (and the long-lost Audiofanboy) made to this thread...we probably would not be at the current dizzy heights if it weren't for you guys...'Hall of Fame' should you both grace, lol!


 
 Not feeling guilty by making you feel nostalgic 
	

	
	
		
		

		
		
	


	




 and thank you Hypnos. 
	

	
	
		
		

		
		
	


	



 Just did what I love to do when I had a lot of time for it. 
	

	
	
		
		

		
		
	


	



  
 Yeah, Audiofanboy was a great innovator.
  
 Now, on to the C3GS and beyond! 
	

	
	
		
		

		
		
	


	




 lol You guys have done an amazing job here.


----------



## Oskari

trolldragon said:


> The Pentode/Heptode days were some of the most enjoyable, active and innovative times in this thread.


 
  
 "Guess who made this 'Siemens' EH90." Lots of fun.


----------



## mab1376

hypnos1 said:


> Now I'm getting _really_ nostalgic, A11!..And I suspect there are a good few more recent members who don't realise the tremendous contributions you (and the long-lost Audiofanboy) made to this thread...we probably would not be at the current dizzy heights if it weren't for you guys...'Hall of Fame' should you both grace, lol!


 
  
 Looks like he sold his LD 
  
 http://www.head-fi.org/t/701183/flash-sale-little-dot-mk-iv-se-220v-like-new-sep-2013


----------



## TrollDragon

oskari said:


> "Guess who made this 'Siemens' EH90?" Lots of fun.


 
 Ribbed or Smooth...


----------



## hypnos1

mab1376 said:


> Looks like he sold his LD
> 
> http://www.head-fi.org/t/701183/flash-sale-little-dot-mk-iv-se-220v-like-new-sep-2013


 
  
 Oh...let's hope all was (and _is_) well with him...


----------



## gibosi

hypnos1 said:


> Oh...let's hope all was (and _is_) well with him...


 
  
 My recollection is that this was his father's amp.... 
  
 "essentially the same way it was when I received it, since I barely touched it."
  
 He definitely "touched" his! lol


----------



## MIKELAP

Speaking of  Audiofanboy we had met once with his father here in Montreal summer of 2013 while he was on vacation here from France had shown him the sites here in town with the wife it was fun .had a nice day that's him in the middle. A couple weeks ago i sent him a pm and i got a short reply he says all is well he's still in Japan and will be for awhile he has no gear with him over there thats about it short and sweet .


----------



## TrollDragon

Nice shot of the Oratoire Saint-Joseph du Mont-Royal...


----------



## i luvmusic 2

mikelap said:


> Speaking of  Audiofanboy we had met once with his father here in Montreal summer of 2013 while he was on vacation here from France had shown him the sites here in town with the wife it was fun .had a nice day that's him in the middle. A couple weeks ago i sent him a pm and i got a short reply he says all is well he's still in Japan and will be for awhile he has no gear with him over there thats about it short and sweet .


 
 The last time i was there it was 12 years ago,it's been awhile..........


----------



## Uncle AL

gibosi said:


> Yes, I realize this...lol...  I have something over 700 tubes as a result of this insanity, and more on the way..... And you should count yourself lucky in that you can skip all the pentodes and heptodes we went through before finally getting to double triodes. Most of my 700 plus tubes are in a pile labeled "not good enough!". lol
> 
> Enjoy! .



Do you allow burn-in time prior to assessment of tube performance, or is that not considered in initial determination?


----------



## i luvmusic 2

While you guys are busy playing with your tubes  i'am having SEX.


----------



## gibosi

uncle al said:


> Do you allow burn-in time prior to assessment of tube performance, or is that not considered in initial determination?


 
  
 Yes, I usually burn tubes for 25 to 30 hours before making any assessments. However, many of the better double triodes are used, and therefore, already burned in.


----------



## MIKELAP

i luvmusic 2 said:


> While you guys are busy playing with your tubes  i'am having SEX.


 
 WOO OUUUUUUUUUUUU!!!!!!!!!!!!!!


----------



## Uncle AL

i luvmusic 2 said:


> While you guys are busy playing with your tubes  i'am having SEX.



Some of us have nice tubes 


gibosi said:


> Yes, I usually burn tubes for 25 to 30 hours before making any assessments. However, many of the better double triodes are used, and therefore, already burned in.



Looking forward to trying some of the double triodes


----------



## i luvmusic 2

mikelap said:


> i luvmusic 2 said:
> 
> 
> > While you guys are busy playing with your tubes  i'am having SEX.
> ...


 
 It's certainly nice to say WOO WOO WOO while you are having SEX........
	

	
	
		
		

		
		
	


	





uncle al said:


> i luvmusic 2 said:
> 
> 
> > While you guys are busy playing with your tubes  i'am having SEX.
> ...


 
 It's not all about nice tubes ask her.


----------



## Uncle AL

I know, I luvmusic2... there are those who have an Awesome pair of headphones


----------



## i luvmusic 2

uncle al said:


> I know, I luvmusic2... there are those who have an Awesome pair of headphones


----------



## i luvmusic 2

To be honest it is easier to have CRACK than SEX..................


----------



## gibosi

I don't even need an amp! With 100s' of tubes, I can sniff getter gas all day long...


----------



## Uncle AL

i luvmusic 2 said:


> To be honest it is easier to have CRACK than SEX..................



Woooo Hooooo


----------



## i luvmusic 2

gibosi said:


> I don't even need an amp! With 100s' of tubes, I can sniff getter gas all day long...


 
 If you like to share some Getter Gas you know who to call.....


----------



## i luvmusic 2

Anyone here have used those NOS Russian ceramic rotary switches?
  
 I want to make a SOURCE SELECTOR.


----------



## bbmiller

trolldragon said:


> Well I received a MOST EXCELLENT gift today, four Yugoslavians came to live here in Nova Scotia!
> 
> 
> 
> Running 6GU7's as power tubes in this setup and these little Yugo's sound incredible!


 
 OK your incredible gift of four Yugoslavian's that came to Nova Scotia. It is not clear to me if all 6GU7 come from Yugoslavia it seems eBay sells one branded as Sylvania. Are those not the good ones?
  
 So are you saying between Yugoslavian inexpensive 6HM5's and 6GU7 (inexpensive or not) you can have a complete plug-and-play replacement for stock tubes in the little dot IV MK SE which will be completely plug-and-play and pretty inexpensive?


----------



## Acapella11

Off topic but I just made a nice discovery playing tunes from AIMP3 instead Foobar2k (both WASAPI) and I am coming to the conclusion to use probably AIMP3 as my standard player. Recommend trying it out.


----------



## TrollDragon

bbmiller said:


> OK your incredible gift of four Yugoslavian's that came to Nova Scotia. It is not clear to me if all 6GU7 come from Yugoslavia it seems eBay sells one branded as Sylvania. Are those not the good ones?
> 
> So are you saying between Yugoslavian inexpensive 6HM5's and 6GU7 (inexpensive or not) you can have a complete plug-and-play replacement for stock tubes in the little dot IV MK SE which will be completely plug-and-play and pretty inexpensive?


 

 Hey bbmiller,
  
 The 4 pictured tubes are all 6HM5's from Yugoslavia you need the TALL version like the ones pictured, NOT the little short ones that can also be found on eBay.
  
 Get the tall 6HM5,'s from this seller, most of the users of this thread has bought them from him.
 http://www.ebay.com/itm/6HM5-6HA5-EC900-export-quality-audio-triode-tube-NOS-FREE-SHIPPING-/300879467071
  
 The 6GU7's are the two tubes in the back of my amplifier, where the 6H30Pi usually go. They are just your general run of the mill Colour TV Matrix tubes that can also be used for audio amplification.
  
 Both of these tube pairs, the 6HM5 and 6GU7 are plug an play replacements that you could use.
  
 6HM5's in the front, 6GU7's in the back.


----------



## gibosi

bbmiller said:


> OK your incredible gift of four Yugoslavian's that came to Nova Scotia. It is not clear to me if all 6GU7 come from Yugoslavia it seems eBay sells one branded as Sylvania. Are those not the good ones?
> 
> So are you saying between Yugoslavian inexpensive 6HM5's and 6GU7 (inexpensive or not) you can have a complete plug-and-play replacement for stock tubes in the little dot IV MK SE which will be completely plug-and-play and pretty inexpensive?


 
  
 The 6GU7 was manufactured by RCA, Sylvania  and a number  of other American companies. I do not think these were manufactured in eastern Europe.
  
 If you are interested in the 6GU7, I would also suggest the 6CG7 and 6FQ7. These tubes are essentially a 6SN7 shoehorned into a 9-pin glass bottle. The 6CG7 has a shield whereas the 6FQ7 doesn't, but in our LD's this difference doesn't matter. A number of our members have rolled these as power tubes, but found genuine 6SN7's to be better. On the other hand, if someone doesn't want to go to the trouble and expense of purchasing adapters, these are completely plug and play and fairly cheap.


----------



## superdux

Wow these 6GU7 are cheap. Gonna get a pair for my LDMKIII!


----------



## Rossliew

trolldragon said:


> The B+ on the LD III & IV is around 200V as well, I have not measured it specifically but all the filter caps are rated at 250V so it would not be higher or even within a few volts of that.
> 
> The transformer output is AC 175,  multiply by sqrt(2) to convert from RMS and that gives you approximately 247 VDC out of the full wave bridge, subtract the voltage drop from the the filtering resistors and caps you are left with a usable 200VDC


 
 Thanks for that, TD!  Looks like those with the Valhalla can have a bit of fun as we do with the LD 
  
  
 Very tempted to try the Valhalla next.....hmm...


----------



## TrollDragon

I have some 6CG7's & 6FQ7's but there is not a pair between them, all from different MFG's and all look different.
  
 Probably would work and sound the same, BUT the Feng Shui of the amp would be broken using tubes that look different...


----------



## Rossliew

Would the following adapters allow me to use 6DJ8/6922/ECC88 type tubes as driver tubes with the LD Mk 3?
  
http://www.ebay.com/itm/1x-6AQ5-to-6P1-7pin-to-9pin-vacuum-tube-adapter-socket-converter-02-/290973107611?pt=Vintage_Electronics_R2&hash=item43bf59459b


----------



## TrollDragon

rossliew said:


> Would the following adapters allow me to use 6DJ8/6922/ECC88 type tubes as driver tubes with the LD Mk 3?
> 
> http://www.ebay.com/itm/1x-6AQ5-to-6P1-7pin-to-9pin-vacuum-tube-adapter-socket-converter-02-/290973107611?pt=Vintage_Electronics_R2&hash=item43bf59459b


 

 No those are 7Pin to 9Pin converters.
  
 You need to split the 6DJ8 across both 7 Pin sockets to use them as drivers.
 So a DIY solution or Breadboard & Vector sockets is the way to use them.


----------



## gibosi

rossliew said:


> Would the following adapters allow me to use 6DJ8/6922/ECC88 type tubes as driver tubes with the LD Mk 3?
> 
> http://www.ebay.com/itm/1x-6AQ5-to-6P1-7pin-to-9pin-vacuum-tube-adapter-socket-converter-02-/290973107611?pt=Vintage_Electronics_R2&hash=item43bf59459b


 
  
 No. The 7-pin 6AQ5 and the 9-pin 6P1 are beam tetrodes. These beam tetrodes are single channel amps. The 6DJ8 is a two channel amp. It is a double triode. There are two triodes in one bottle. So you need an adapter that will distribute the two channels into two 7-pin sockets, left and right. I accomplish this rather crudely with one 9-pin breadboard socket and two Vector 7-pin test sockets.


----------



## Rossliew

Thanks, gibosi and TD. I managed to scroll back to the earlier postings and found my answer. Not so simple i guess...


----------



## TrollDragon

rossliew said:


> Thanks, gibosi and TD. I managed to scroll back to the earlier postings and found my answer. Not so simple i guess...


 
  
 We ran them on rigs like these back when the dual triodes were just getting implemented.
 Actually quite easy if you have any soldering skills, if not the Vector sockets and Breadboard adapter is solderless.


----------



## MIKELAP

So we can use 6GU7 tubes as power tubes plug&play and what would be there sound sig compared to the 6n6pir russian power tubes or others for that matter.


----------



## gibosi

trolldragon said:


> We ran them on rigs like these back when the dual triodes were just getting implemented.
> Actually quite easy if you have any soldering skills, if not the Vector sockets and Breadboard adapter is solderless.


 
  
 The fact that the breadboard socket and Vectors is a solderless "adapter" makes it very easy to rewire the socket to accommodate tubes with different pin-outs. For example, with a small screwdriver, the wires can be rerouted to run either a 2C51, 12AU7, 5687 or a 6DJ8, as all of these have different pin-outs. And if you get tired of moving wires around, you can then purchase a ready-made adapter, or solder up a rig like TD's.
  
 It appears that the tube in the picture is an ECC85. For those who don't know, this is very similar to a 12AT7/ECC81, with a gain of 60. However, the ECC85 has an electrostatic shield connected to pin-9, whereas, the 12AT7 has a heater center-tap connected to pin-9. The ECC85 is pin-compatible with the 6DJ8. And with a heater drawing 0.435A at 6.3V, these do not require an external heater PS.
  
 The American nomenclature for the ECC85 is 6AQ8. However, I have yet to see an American-made tube. So far, they have all been Philips (Heerlen and Hamburg), Telefunken or Mitsubishi (Japan). These are nice tubes, and not terribly expensive.


----------



## TrollDragon

mikelap said:


> So we can use 6GU7 tubes as power tubes plug&play and what would be there sound sig compared to the 6n6pir russian power tubes or others for that matter.


 

 I don't have any 6Н6П И's so I can't say, but I do find the 6GU7's a tad warmer than the 6H30Pi EB's.


----------



## MIKELAP

trolldragon said:


> I don't have any 6Н6П И's so I can't say, but I do find the 6GU7's a tad warmer than the 6H30Pi EB's.


 
 With that said it would bring them near  the level of the russian 6n6pir i would think thats good because i find the 6H30PI light not as warm as russian toooobes


----------



## Johnnysound

mikelap said:


> With that said it would bring them near  the level of the russian 6n6pir i would think thats good because i find the 6H30PI light not as warm as russian toooobes


 
 Still waiting for the adapters to arrive from China (ordered a month ago) , to try the 6SN7GTs as powers in my LD3.  In the meantime, (following the great advice from various member of this thread) I installed  the excellent Tung-Sol 6485s, NOS sixties, square getters (sorry, no round ones), paired with the stock 6N6PI and the thing is just making beautiful music.  Compared with the EF95s triodes I have, even with  the excellent  Voshkod EV, the pentode Tung-Sol is simply a step above.  It is a quieter tube, more neutral, perhaps "sparkier" in the highs, but these qualities seem to complement very nicely with the "warmth" of the russian 6N6PI.  Not only that, the ambient and "spatial" clues of the music are there in full, with a reverberant, natural  quality that is really fascinating.  I know that there are better tubes out there,  but I personally respect this humble 6N6PI tube,  it can sing and it can sound really good, paired with a competent performer like the TS. So far, the EF92 pentodes seem to outperform the EF95 triodes. is there any technical reason for this ?


----------



## bbmiller

As I have stated earlier in this thread I have been refraining from any tube rolling until the next few days when I go to the Rocky mountain audio Fest (going later today) and I hear some of what all you guys are talking about.
  
 I think the discussion I am hearing at this moment on this thread may be particularly pertinent to my later today exploration of hearing sound from other systems. I own Sennheiser HD 600 and and these are my only audiophile level headphones. On the 600 HD impressions thread many people favor 600 HD's over 650 HD's which are said to have more base which can even be seen in the spectrums published of these two headphones. So how do you all distinguish between warmth and baselevel. On the thread for this year's Rocky mountain audio Fest I ask this someone with more experience might meet up with me to explain me audio fight headphone language. And was given a link to Head-FI's glossary thread which can be found here. According to the glossary thread warmth can be defined this way 
  
  
  
 "Warm - Good bass, adequate low frequencies, adequate fundamentals relative to harmonics. Not thin. Also excessive bass or mid bass. Also, pleasantly spacious, with adequate reverberation at low frequencies. Also see Rich, Round. Warm highs means sweet highs."
  
  
  
 OK then are you guys able to hear warmth even through headphones you know have some based level drop-off in the base spectrum. And is this more than just your tubes inning base spectrum level wise?
  
 I am also wondering if warmth equals better soundstage at bass frequencies or if such distinctions are beyond the capabilities of most human ears to distinguish. If you are able to distinguish such things as soundstage at different frequencies. Do you think say a Latino percussive jazz track of music with many percussive instruments playing side-by-side would be the I deal think to listen to to distinguish warmth and soundstage in the base region or is that not the way it is done?
  
 Incidentally I look like my picture of me holding my niece in my avatar. That is me in that picture. If you are going to be at the Rocky mountain audio Fest in the next few days could you please p.m. me a picture if you would not mind me saying hello to you?


----------



## TrollDragon

Hey bbmiller,

If you want to know what a lot of those descriptions sound like then you should take the Philips Golden ear test.

https://www.goldenears.philips.com

I am one step away from Gold, there is a test at the end with full EQ applied that is hard to do with my old ears.


----------



## Uncle AL

trolldragon said:


> Hey bbmiller,
> 
> The 4 pictured tubes are all 6HM5's from Yugoslavia you need the TALL version like the ones pictured, NOT the little short ones that can also be found on eBay.
> 
> ...



Hey TrollDragon.. Can you please describe the how well the combination of the 6HM5 and 6GU7 perform compared to the MK IV SE stock tubes, including Soundstage, tonality, etc.? Thanks--


----------



## TrollDragon

uncle al said:


> Hey TrollDragon.. Can you please describe the how well the combination of the 6HM5 and 6GU7 perform compared to the MK IV SE stock tubes, including Soundstage, tonality, etc.? Thanks--


I have not listened to the old GE JAN 6AK5's in eons... I'll see if I can dig them up this weekend and install them for a listen.


----------



## MIKELAP

trolldragon said:


> I have not listened to the old GE JAN 6AK5's in eons... I'll see if I can dig them up this weekend and install them for a listen.


 
 Those remind me of the days i use to get ripped off fortunately only happened a couple times lol.


----------



## Demibeard

trolldragon said:


> Hey bbmiller,
> 
> The 4 pictured tubes are all 6HM5's from Yugoslavia you need the TALL version like the ones pictured, NOT the little short ones that can also be found on eBay.
> 
> ...


 
  
 Hi, can I be a complete noob?
  
 Going on the elation and advice on the forum for these tubes (6HM5 and 6GU7), I've ordered a set for my Little Dot MK III.
  
 As I'm currently rolling a pair of 6H30Pi and pair of Mullard M8100, therefore the only thing I need to do to accommodate the new tubes is adjust the jumpers into the EF92 mode?
  
 I'm fairly certain this is the correct thing to do, just wanted to make sure.
  
 Thanks in advance.
  
 Hmm, looks like I've got myself confused and they are just EF95s like the Mullards.
  
 Sorry all.


----------



## TrollDragon

demibeard said:


> Hi, can I be a complete noob?
> 
> Going on the elation and advice on the forum for these tubes (6HM5 and 6GU7), I've ordered a set for my Little Dot MK III.
> 
> ...


 
 I run the 6HM5 in EF95 mode and since the cathode is attached to Pin 2 and Pin 7 it in theory should work in both modes. *BUT* after I pulled up the data sheet, there is a Shield connection on Pin 6 so I would run it in EF95 mode to be safe.


----------



## Demibeard

trolldragon said:


> I run the 6HM5 in EF95 mode and since the cathode is attached to Pin 2 and Pin 7 it in theory should work in both modes. *BUT* after I pulled up the data sheet, there is a Shield connection on Pin 6 so I would run it in EF95 mode to be safe.


 
  
 Thank you for the quick response.
  
 I'll leave the jumpers alone.


----------



## TrollDragon

mikelap said:


> Those remind me of the days i use to get ripped off fortunately only happened a couple times lol.


 
  
 No way... Tell me you didn't get ripped off buying expensive 6AK5/M8100/CV4010's did you?


----------



## MIKELAP

trolldragon said:


> No way... Tell me you didn't get ripped off buying expensive 6AK5/M8100/CV4010's did you?


 
 And guess by who TD........ you guessed it YEN AUDIO lol. Live and learn !


----------



## Uncle AL

demibeard said:


> Hi, can I be a complete noob?
> 
> Going on the elation and advice on the forum for these tubes (6HM5 and 6GU7), I've ordered a set for my Little Dot MK III.
> 
> ...



Hey Demibeard... I'm interested in the same tube rolling, but for a MK IV SE. Once you've had a chance to try these new tubes, it would add to overall impressions for the 6HM5 and 6GU7 combo.


----------



## Uncle AL

. . . Just ordered 6HM5 Yugoslavian and 6GU7 tubes, many of you appear to enjoy


----------



## Demibeard

uncle al said:


> . . . Just ordered 6HM5 Yugoslavian and 6GU7 tubes, many of you appear to enjoy


 

 This forum has been a such a drain on my wallet 
	

	
	
		
		

		
		
	


	




, and to think, I only came here to get some settings for my walkman (NWZ-A828).
  
 I'm not very eloquent, but when the new tubes arrive, I'll try to compare them as best I can.
  
 At least these tubes aren't as expensive as other things.


----------



## i luvmusic 2

Yes indeed,if your not careful your wallet might runaway from you.


----------



## mordy

Hi,
  
 Although the 6FQ7/6CG7 tubes work as power tubes in the LD MKIII, I would not recommend them. I did try them, and there was something with them that was not compatible with the driver tube I was using (12AX7 family).
  
 As driver tubes they were pretty good, and you could find real bargains in looking for 8V tubes - 8FQ7/8CG7. There are also 12V versions, but it seems that they are used in certain high end amps, and they cost much more.


----------



## CITIZENLIN

i luvmusic 2 said:


> Yes indeed,if your not careful your wallet might runaway from you.



 


What wallet??? They took my wallet too.


----------



## gibosi

mordy said:


> Although the 6FQ7/6CG7 tubes work as power tubes in the LD MKIII, I would not recommend them. I did try them, and there was something with them that was not compatible with the driver tube I was using (12AX7 family).
> 
> As driver tubes they were pretty good, and you could find real bargains in looking for 8V tubes - 8FQ7/8CG7. There are also 12V versions, but it seems that they are used in certain high end amps, and they cost much more.


 
  
 As the 6FQ7/6CG7 is electrically the same as the 6SN7, I would suspect the incompatibility was caused by the 12AX7. The 12AX7 has a gain of 100, which is quite high compared to a gain of 20 for a 6SN7 or 33 for a 6DJ8, and perhaps too high to drive a 6CG7. I am curious to learn how they will sound paired with a 6HM5 or a medium-mu double triode.


----------



## TrollDragon

citizenlin said:


> What wallet??? They took my wallet too.


 
 That is a serious collection of Mod's and Cart's in your Avatar...
 Vaping gear ramps up quickly in price too, at least here in Canada. I just picked up an Aspire mini Nautilus, and need a decent variable wattage battery to go with it.


----------



## electroshock

Hello this is my first post after lurking for the past few months.
  
 I have been playing with a LD 1+ trying to absorb as much as I can from this and other forums.  I thought I would share some of the things I have learned and some of the mistakes I made so far. My main means of using the forum has been through using the search.  This has saved time but it also means I missed key bits of info concerning some of the modifications. My biggest mistake so far has been making a 6DJ8 adaptor for the LD 1+ without realizing the
 noise issue with this model. 
 I used a Hammond box, the 7 pin test connectors from Radiodaze and 9 pin socket.  I bought a matched (2nd mistake) pair of Amperex Bugle Boy 6DJ8 ECC88 tubes from Ebay. These are marked a little different than other Amperex tubes I have seen as they have a treble clef mark separate from the standard bugle boy logo.


  
  
  After about 8 hours of break in the tube sounds great with all the sound stage and detail folks have talked about but there is a persistent small hum in the right channel that will not go away even with pins 8 and 9 connected.  I even tried connecting Pin 3 which is the cathode for other channel to ground but this just generated a much louder hum.
  
 The best performing tube I have found so far is a $3 pair of Sylvania NOS untested 6DT6 tubes in EF95 with Pins 1 and 7 connected which I achieved by running a jumper on a set of 7 pin test connectors per Page 77.

  
  I am running the Muse 02 DAC chip which I believe is a little better than the dual SOIC LME49990. However I must say that that the DAC in the LD 1+ does have a major effect on the stage and detail of the sound so there is probably not a perfect correlation of how tubes change the sound in this amp versus others in the LD product line but that's a topic for another thread.
* *
 Just a couple of questions on stuff I have not figured out yet
  
 Is there any solution to the 6DJ8 noise problem on the LD 1+ I may have missed?
  
 Do the other options listed on Page 77 for the 6DT6 (6/7 pin mod and 2/7 pin mod) make any difference to the way the 6DT6 tube sounds?
  
 Will the 5687WA modification with the external heater work with the LD 1+ (I assume yes as gibosi has advocated for this mod).  Also is there a wiring diagram for this mod? I found the parts list that gibosi made but I have not found a diagram. I am hoping I may be able to salvage my box by using it with this mod.  
  
 Finally will the C3G mod work with the LD 1+ using the double adaptor modification?
  
 Thanks for any additional insight the members of this forum can provide and also for all the help this forum has provided in the past. The strength and number of involved members on this forum is the reason I purchased a Little Dot. I started with the low end model so I can make most of my errors with this amp before blowing up more expensive hardware. I am enjoying my first tube rolling experience thanks to all the info available on the forum.
  
  
.​


----------



## TrollDragon

electroshock said:


> Is there any solution to the 6DJ8 noise problem on the LD 1+ I may have missed?


 
 Excellent work on the Adapter box it looks great.
  
 Possibly your heater wires are running too close to the other pins? Heater wires need to be twisted and separated a fair distance from other wires or run at 90 degrees across the other wires if you don't have the room. The heater wires will induce AC hum into the circuit.


----------



## gibosi

electroshock said:


> Is there any solution to the 6DJ8 noise problem on the LD 1+ I may have missed?
> 
> Do the other options listed on Page 77 for the 6DT6 (6/7 pin mod and 2/7 pin mod) make any difference to the way the 6DT6 tube sounds?
> 
> ...


 
  
 1) In my experience the 6DJ8's are the noisiest double triodes in my collection. They are very susceptible to heater noise and random RF. An external DC heater PS helps quite a bit. And since you have built a case for your adapter, you might try putting some ERS shielding paper on the inside. However, as my 9-pin breadboard adapter is open to the air, I haven't tried this....
  
 http://www.partsconnexion.com/accessories_ers.html
  
 2) Yes, each strapping changes the sound of the 6DT6. However, it has been a long time since I rolled that tube, so I can't say how these other strappings sounded.
  
 3) Here is a picture of a 9-pin breadboard socket wired to run the 5687 using an external DC heater PS.
  

  
 4) And a pic of two 3Cg's plus adapters plugged into 7-pin vectors.


----------



## CITIZENLIN

trolldragon said:


> That is a serious collection of Mod's and Cart's in your Avatar...
> 
> 
> Vaping gear ramps up quickly in price too, at least here in Canada. I just picked up an Aspire mini Nautilus, and need a decent variable wattage battery to go with it.






I don't have Aspire mini Nautilus but I heard so much good things about it. Here are my latest to my collection. As far as variable wattage, you can pick up DNA 30 for around 70USD.

I sent you PM.


----------



## Uncle AL

demibeard said:


> This forum has been a such a drain on my wallet  , and to think, I only came here to get some settings for my walkman (NWZ-A828).
> 
> I'm not very eloquent, but when the new tubes arrive, I'll try to compare them as best I can.
> 
> At least these tubes aren't as expensive as other things.



To All-- Are there any impressions about the combination of 6HM5s with 6H30PI power tubes? I ordered 6GU7s but wondering difference of these tubes versus leaving 6H30PIs in place and simply replacing M8100s with 6HM5s?

P.S., I'm not into vamping, but I really enjoy the decadence of a Cuban cigar with a single malt scotch, on occasion...


----------



## CITIZENLIN

uncle al said:


> To All-- Are there any impressions about the combination of 6HM5s with 6H30PI power tubes? I ordered 6GU7s but wondering difference of these tubes versus leaving 6H30PIs in place and simply replacing M8100s with 6HM5s?
> 
> 
> 
> P.S., I'm not into vamping, but I really enjoy the decadence of a Cuban cigar with a single malt scotch, on occasion...



 


Hello Uncle Al,

6HM5s and 6H30PIs combo is the best plug and play set up with my MK IV but my current set up is C3gs and 6SN7s. I can't go back to plug and play anymore. But I do play 6HM5s with 6SN7s set up sometimes. Oh yeah!!! this week is my 5th anniversary of " totally free from analog cigarette or cigar""


Cheers


----------



## TrollDragon

citizenlin said:


> Oh yeah!!! this week is my 5th anniversary of " totally free from analog cigarette or cigar""
> 
> 
> Cheers


 
  
 Much Congrats!
  
 The new ones you posted are nice, and thanks for the PM I'll check into them.


----------



## TrollDragon

uncle al said:


> I'm not into vamping, but I really enjoy the decadence of a Cuban cigar with a single malt scotch, on occasion...


 
  
 A fine listening session was had here...


----------



## mordy

Hi electroshock,
  
 If you use the search option on top of the page you will find a lot of material on the 6DT6 ("Detox") tube. Here is an excerpt from post #3056:
  
_Started out with the EF95 1/7, but now I use EF92 setting without a strap, and I am happy with this ( but I liked the EF85 1/7 setting as well) . My 6DTA6 tubes in use at this time are Japanese made, either by Hitachi or Toshiba and perhaps they come from the same factory as the (demystified?) Siemens Foreign and Haltron tubes._
_IMHO the 6DT6 tubes require 30-50 hours burn in to enter their prime._
  
_Changing the strap settings has a big effect on the sound, and it is usually easy to pick out the best combination. _I admire your work on making the adapter - wish I had those skills. In the past I found that grounding the amp chassis helped to reduce hum. Don't overlook RF sources such as portable phones etc in close proximity to the amp.


----------



## gibosi

electroshock said:


> Will the 5687WA modification with the external heater work with the LD 1+ (I assume yes as gibosi has advocated for this mod).  Also is there a wiring diagram for this mod? I found the parts list that gibosi made but I have not found a diagram. I am hoping I may be able to salvage my box by using it with this mod.


 
  
 Not exactly sure what kind of wiring diagram you are asking for....
  
 If you are asking how to wire up an external DC heater PS, this might help:
  
 http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/4410#post_10076232
  
 If you are asking how to wire your 9-pin socket to the LD's two 7-pin sockets in order to run an 5687WA, this might help:
  
 http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/6885#post_10722910


----------



## electroshock

trolldragon said:


> Excellent work on the Adapter box it looks great.
> 
> Possibly your heater wires are running too close to the other pins? Heater wires need to be twisted and separated a fair distance from other wires or run at 90 degrees across the other wires if you don't have the room. The heater wires will induce AC hum into the circuit.


 

 Thanks for the tip I will give that a try as the inside of the box looks like a birds nest...


----------



## electroshock

gibosi said:


> Not exactly sure what kind of wiring diagram you are asking for....
> 
> If you are asking how to wire up an external DC heater PS, this might help:
> 
> ...


 
 Wow thanks gibosi both of these links are exactly what I was looking for.  I am going to order the components and start playing around. Thanks also for your earlier post on the 6DJ8. I tried moving the wires inside the box as TrollDragon suggested but it did not seem to make a difference with this setup.  I think I am going to just concentrate on 6TD6 strap options and getting the 5687 setup as I was able to get a Sylvania 5687WA with a mfg date of 9-64 that I am excited to try. I post again when I get everything setup.


----------



## electroshock

mordy said:


> Hi electroshock,
> 
> If you use the search option on top of the page you will find a lot of material on the 6DT6 ("Detox") tube. Here is an excerpt from post #3056:
> 
> ...


 
 Thanks mordy for the kind words and the info. I like the idea of being able to plug the 6DTA tubes directly into the board with the EF92 setting.  I am going to play around with the strap settings while I am waiting for the external voltage components.


----------



## bbmiller

> Originally Posted by *TrollDragon* /img/forum/go_quote.gif
> 
> Get the tall 6HM5,'s from this seller, most of the users of this thread has bought them from him.
> http://www.ebay.com/itm/6HM5-6HA5-EC900-export-quality-audio-triode-tube-NOS-FREE-SHIPPING-/300879467071


 
 Are these the tall ones as well? 
    6HM5 EC900 - lot 10 pcs EI Yugoslavia


----------



## Uncle AL

Awhile back, there was a photo of a large collection of vacuum tubes stored neatly in drawers. May I suggest, that along with useful discussion of tube rolling and adapting, that head-fiers post photos of how they maintain their inventory of vacuum tubes?


----------



## Rossliew

bbmiller said:


> Are these the tall ones as well?
> 6HM5 EC900 - lot 10 pcs EI Yugoslavia


 
 Yes, these will do.


----------



## MIKELAP

rossliew said:


> Yes, these will do.


 
 bbmiller those are the ones i bought just remind the guy to pack them well ,because when i got mine 2 of them were broken the guy says i put them in a foam box yes he did but they were bouncing around in there Hmm..tell him you know somebody that happened to recently maybe he will do a better job this time dont think he'd like negative feedback i am waiting for replacements .


----------



## MIKELAP

rossliew said:


> Yes, these will do.


----------



## bbmiller

mikelap said:


> rossliew said:
> 
> 
> > Yes, these will do.
> ...


 
 Thanks MIKELAP. I just sent the message to eBay they, Say it can take two days for him to reply.


----------



## TrollDragon

Well I did a little playing on the weekend between feeds of Turkey... 
	

	
	
		
		

		
			




  

  
 These are the tubes I ran in the MK IV for a little listen, from left to right are the modified Octal Drivers, Regular Drivers and Output's. They are placed in the order of what I enjoyed best to least. Various music genre's were listened to and I was using the modded DBV3 style Fostex T50RP's. The house was full of family from near and far so there was absolutely no chance to listen with the beyerdynamic DT880 Pro's. 
	

	
	
		
		

		
		
	


	



  


Spoiler: DBV3 Fostex T50RP terminated with mini XLR & Toxic Cables 6.5mm






  
 Groups Left to Right:

Sylvania JAN 5751, Raytheon 6832, Sylvania JAN CHS 6SL7GT
EI Yugoslavian 6HM5, GE JAN 5654
Electro-Harmonix 6H30Pi-EH, OE NEC Japan 6GU7, RCA Cleartop 6CG7
  
 The output tubes in group 3 don't really offer a major change to the sound of the amplifier. The 6H30Pi's do have the best sound of the three types I tried, they have the best range and deliver the highest output level, they are very smooth with great detail. The 6GU7's are a nice inexpensive solution for a replacement to the 6H30Pi's, they have a little more amplification but don't really deliver the same level of output. This is understandable as the LD's circuit was NOT designed around the 6GU7 so one cannot expect the same level of performance. The 6CG7's... Well I just don't like them at all, it seems to me that there is something a little "Off" in the sound that is hard to describe. It could very well be the ones I have (3 different makes) but I would not choose them as a replacement output tube. As with any tube review it is all subjective, my gears & my ears so your mileage will vary.
  
 The regular drivers in group 2 were really no competition when it comes to sound, just like switching from AM radio (5654) over to FM radio (6HM5) the difference is a very welcome upgrade to the quality of sound over the stock 5654's.  The first thing you notice on the 6HM5's is where did that nice bass come from? The bass is far from overpowering, the tube is very musical and easy to listen to. The EI 6HM5 is one of the quickest and most cost effective upgrades you can to for your Little Dot, but order 3 or 4 as you will want a spare or two.
  
 Modifying your Little Dot to accept dual triodes like the ones in group 1 is an upgrade that will be Head and Tails above even the best 6HM5 type drivers when it comes to overall sound quality and presentation. There are SO MANY choices and options to be experimented with when you decide to take your first step down that rabbit hole that is Dual Triode Land, you will seriously have to do some research first as to which path you want to take.  Now you will be looking for tubes on eBay that 90% of the world searches for so the prices ramp up consideribly, also the chance of getting taken by shady sellers increases as a lot of these tubes are in much higher demand. You really need to be an informed buyer to know what you are looking for and what it is that the seller is actually selling. There are many great deals that come along when looking for 6DJ8 / 6SN7 type tubes but you might have to camp out on eBay for a time and that is a discussion that those who know how to work the eBay system can help with.
  
 I am not going to describe the sound of the group 1 tubes as there are so many variations of them and they do change from manufacturer to manufacturer even year to year. When you do make an adapter for the Little Dot you can change tubes and sound at whim without jumper or switch settings coming into play. Just shut down, change tubes and in a minute or two you are good to go again with a whole new sound.
  
  
 The Westinghouse CWL-6BQ7A is one of my absolute favorites when it comes to the 6DJ8 style of tubes. I listen to this tube a lot and really enjoy it, the 6BQ7A is a very musical and euphonic tube.

  
 Considering the tubes in group 1, the one with the most detail and upper presence is the 5751 which is an update to the 12AX7 tube. They have lowered the µ to 70 on it and increased the current/bandwidth. This is the reason the 5751 is very popular as a preamp tube, the pair I have came from a Jolida phono stage after a friend upgraded his tubes. The sub miniature Raytheon 6832 is another great tube that is on par with a lot of the 6DJ8 tubes on the market but it does require a custom made adapter to use it conveniently with plug and play. Lastly the 6SL7GT is another driver option that does not require an external power source to use. There are literally 100's of different 6SL7's out there to choose from, I don't have a large selection of these but out of the ones I do have this one is the best sounding to my ears. I have one that is very microphonic that does have a better sound than the one pictured but the noise from it is more annoying than the sound benefit so it does not get much use. This is apparently a common trait of 6S?7 tubes, they might or might not be microphonic so you take a chance when purchasing them.
  
  
 Well I don't know if this will be an informative post to those new to our fun little game of rolling tubes in the Little Dot amplifier. It is all subjective and without a way to volume match the output of each of these tubes all reviews will have to be taken on what the reviewer hears with their ears and gears. To actually compare the output of the tubes properly, it does require some sort of SPL meter. You are not able to match volume by ear since audio memory is very short and each tube will have a different gain that reflects in the level of the output volume.


----------



## sssboa

sssboa said:


> OK, thx
> Just ordered a pair of c3g and 6SN7 with all adapters.
> I took 6SN7 vintage Sylvania nice looking black plate, chrome top, moderately priced, I doubt they affect quality really so want them to be lookers


 

 So the tubes arrived.
 C3G do not much my Beyerdynamic DT880 headphones at all, bass is bloated and poorly controlled, Voshod perform much better, also they (c3g) don't sound much off some bassy ef95 tubes. it's my problem with beyerdynamic DT770/880/990 cans that most tubes make them sound too warm and with overwhelming bass, so after months of testing very wide array of tubes I singled out Soviet EF95 Voshod and EF92 Mullard as best sounding with my phones, still very warm but not too (I use M8081 but I think all EF92 sound very similar if not the same as opposed to EF95 that differ a lot from brand to brand, all EF91 sounded too warm to me and also similar too each other but clearly Mullard had best highs, with military model having a slight edge maybe) . 
 6SN7 look cool when off, when on they do not glow much and do not think they add anything to the sound over my default type of power tubes (Soviet 6N6P), not sure if they (6SN7) do not add some very subtle humming in the background though and crackling when the amp is touched, I also bought 6SN7 Tung-sols with black plates, normally very expensive, they look like piece of art and it's probably waste to use them as power tubes.
 C3G and their adaptors will be for sale probably.


----------



## i luvmusic 2

I finally finished my SEX amp........Thank GOD!!!!!!!!!


----------



## Uncle AL

i luvmusic 2 said:


> I finally finished my SEX amp........Thank GOD!!!!!!!!!



Nice--- Photos and first hand impressions please? ...after burn-in


----------



## i luvmusic 2

uncle al said:


> i luvmusic 2 said:
> 
> 
> > I finally finished my SEX amp........Thank GOD!!!!!!!!!
> ...


 
  With all the amp i have the SEX is more detailed of them all,The voice sound natural and the soundstage is bigger/wider and something that this amp made me realized some of the classical music i listened to can sounds like the orchestra are in front of you instead of sounding like you are in the middle i even noticed some sound slightly above my head/ear.Those can be heard with the CRACK and MK III but you really need to focused on them or you will never noticed that sound i never noticed those until i listened to SEX.
  
 SEX IS GOOD!!!!!!!!!!!!!


----------



## Uncle AL

Thanks i luvmusic 2..
  
 ...It looks like you were having fun with the connections.  Congratulations on your skill in handling the soldering iron so well for such a well deserved result.  Your review is enough to make me want to order SEX, too.  No, not that kind.. the how-to assemblage of electronic components in a concerted effort to achieve maximum enjoyment from the results.  Okay.. now, I see why they named this amp SEX, because it is THAT GOOD, and drives the listener to achieve new heights of soundstage and tonal enrichment.
  
 Did you order the stock tubes?.. or alternatives?  The point-to-point wiring kind of reminds me of the old breadboard wiring that I used to do eons ago, but one cannot sit on the sidelines and criticize how SEX comes together.  The results are what counts, and it sounds like the fun of connecting up the elements and the overwhelming climactic sound is more than enough to have head-fiers saying,
  
_"I'll have what she's having!"_        
	

	
	
		
		

		
		
	


	



 Right now is when I would be reaching for a Cuban cigar and brandy, as I relax in the afterglow of imagined radiance and allure of the SEX amp's curvacious encased filaments and overall amplification goodness!
  
 Enjoy your SEX... and thank you for sharing with us!


----------



## Rossliew

Received the 12AX7/12AU7 adapter (for use as driver tubes) from @MIKELAP today and listening to the set up now with some 12AU7s as driver and RCA 6SN7s as power tubes - euphonic lushness making the LD3 warmer sounding, smooth and creamy with some punchy bass. Next up would be some 12AX7s and 6SL7-type octals (with adapter).
  
 BTW, anyone tried ordering from China recently? I think the customs there is doing some VERY stringent checks on all goods exported out of the country. A friend who ordered some kiddy backpacks faced such a situation with the backpack sitting at Chinese customs for more than a week. If anyone here has bought adapters from Chinese sellers, did you receive them on time? I may want to hold back on getting some C3G adapters if this is so...


----------



## MIKELAP

rossliew said:


> Received the 12AX7/12AU7 adapter (for use as driver tubes) from @MIKELAP today and listening to the set up now with some 12AU7s as driver and RCA 6SN7s as power tubes - euphonic lushness making the LD3 warmer sounding, smooth and creamy with some punchy bass. Next up would be some 12AX7s and 6SL7-type octals (with adapter).
> 
> BTW, anyone tried ordering from China recently? I think the customs there is doing some VERY stringent checks on all goods exported out of the country. A friend who ordered some kiddy backpacks faced such a situation with the backpack sitting at Chinese customs for more than a week. If anyone here has bought adapters from Chinese sellers, did you receive them on time? I may want to hold back on getting some C3G adapters if this is so...


 
 i ordered a couple adapters they were shipped on the 11/10/14 usually takes a month


----------



## mab1376

I have a pair of Tung Sol JAN-CTL-6SU7GTY (6SL7 type) coming in to use as power tubes, to replace my new production 6SN7GTB tubes.
  
 I very much like the sound as a driver so hopefully it benefits in the same way. (very well pronounced bass with sweet treble)
  
 Also this track keeps fooling me with the c3g's, i keep thinking speakers are on.


----------



## Acapella11

sssboa said:


> So the tubes arrived.
> C3G do not much my Beyerdynamic DT880 headphones at all, bass is bloated and poorly controlled, Voshod perform much better, also they (c3g) don't sound much off some bassy ef95 tubes. it's my problem with beyerdynamic DT770/880/990 cans that most tubes make them sound too warm and with overwhelming bass, so after months of testing very wide array of tubes I singled out Soviet EF95 Voshod and EF92 Mullard as best sounding with my phones, still very warm but not too (I use M8081 but I think all EF92 sound very similar if not the same as opposed to EF95 that differ a lot from brand to brand, all EF91 sounded too warm to me and also similar too each other but clearly Mullard had best highs, with military model having a slight edge maybe) .
> 6SN7 look cool when off, when on they do not glow much and do not think they add anything to the sound over my default type of power tubes (Soviet 6N6P), not sure if they (6SN7) do not add some very subtle humming in the background though and crackling when the amp is touched, I also bought 6SN7 Tung-sols with black plates, normally very expensive, they look like piece of art and it's probably waste to use them as power tubes.
> C3G and their adaptors will be for sale probably.


 
 First thing, as everybody here would suggest, do get some Ei 6HM5 as driver tubes. They are not on the warm side, rather neutral and should fit your Beyerdynamics quite well, if that is what you are looking after.
 I would wait with the sale until I had the 6HM5s because you may discover the differences between the power tubes much better when using those. Also, depending on the year of production (older is better), I found the 6N6P tubes to be the weakest of all tubes (YMMV) and recommend as a first upgrade the 6N6P-IR as they massively increase stage, but also treble and deep bass.


----------



## Acapella11

trolldragon said:


> ...
> The output tubes in group 3 don't really offer a major change to the sound of the amplifier. The 6H30Pi's do have the best sound of the three types I tried, they have the best range and deliver the highest output level, they are very smooth with great detail. The 6GU7's are a nice inexpensive solution for a replacement to the 6H30Pi's, they have a little more amplification but don't really deliver the same level of output. This is understandable as the LD's circuit was NOT designed around the 6GU7 so one cannot expect the same level of performance. The 6CG7's... Well I just don't like them at all, it seems to me that there is something a little "Off" in the sound that is hard to describe. It could very well be the ones I have (3 different makes) but I would not choose them as a replacement output tube. As with any tube review it is all subjective, my gears & my ears so your mileage will vary.
> 
> ...


 
  
 Hey TD, if you do not want to jump onto the bandwagon of alternative driver tubes with adapters but the best in sound you can get, classically, the high budget pre-1984 6H30P-DR might come handy. Just saying ...


----------



## mab1376

acapella11 said:


> First thing, as everybody here would suggest, do get some Ei 6HM5 as driver tubes. They are not on the warm side, rather neutral and should fit your Beyerdynamics quite well, if that is what you are looking after.
> I would wait with the sale until I had the 6HM5s because you may discover the differences between the power tubes much better when using those. Also, depending on the year of production (older is better), I found the 6N6P tubes to be the weakest of all tubes (YMMV) and recommend as a first upgrade the 6N6P-IR as they massively increase stage, but also treble and deep bass.


 
  
 I've had a poor experience with Beyers as well with the c3g. (T70)
  
 They're so ridiculously sensitive so they have a little buzz in the background and are pretty sibilant, even on low gain.
  
 The c3g pairs amazingly with the HD650.


----------



## JazzVinyl

I finally have my C3gS's and my C3g -> 6AK5 socket adapters. 
Sad to say, only one of the two adapter sockets, work. I have notified the ebay seller.

Interesting to read the poor results with C3g and Beyerdynamic phones...my favorite cans are the Beyer DT-990's but it looks like I will have to wait another month of Sundays to hear my C3gS's with my cans. 

Ugh!!


----------



## JazzVinyl

Also got my socket adapters to use 6SN7's as power tubes...

Happy to report both of these, do work perfectly.....


----------



## superdux

@rossliew

you certainly should try the 6N23P from the 70's voskhod factory, they are a dream. Especially voices sound silky and "creamy" to me.I've auditioned the grey shields 79' and the silver shield 78'.If its the same adapter MIKELAP had sold me you'd just need an 12AUX7 to 6N23P adapter to try these.


----------



## bbmiller

mab1376 said:


> I have a pair of Tung Sol JAN-CTL-6SU7GTY (6SL7 type) coming in to use as power tubes, to replace my new production 6SN7GTB tubes.


 
 You are confusing me. According to datasheets I have been consulting 6SU7GTY uses .3 A heater current so you are all right with the amplifiers commonly talked about on this thread. But if in a new factory production you got a amplifier with 6SN7GTB in place this requires .6 A heater current exceeding heater current capabilities of the amplifiers commonly talked about in this thread, but perhaps not exceeding what is possible with the more expensive little dot amplifiers. So what amplifier are we talking about?
  
 PS OK catching article on the web about the history of tubes you are not probably talking about new production little dot amplifiers, but probably new production tubes. So I guess you were supplying external heater current with your  new production 6SN7GTB tubes So I posted a stupid question sorry.


----------



## i luvmusic 2

uncle al said:


> Thanks i luvmusic 2..
> 
> ...It looks like you were having fun with the connections.  Congratulations on your skill in handling the soldering iron so well for such a well deserved result.  Your review is enough to make me want to order SEX, too.  No, not that kind.. the how-to assemblage of electronic components in a concerted effort to achieve maximum enjoyment from the results.  Okay.. now, I see why they named this amp SEX, because it is THAT GOOD, and drives the listener to achieve new heights of soundstage and tonal enrichment.
> 
> ...


 
  Yes indeed i have lots of fun soldering,I cut all the wires longer than how it should be for future modding C4S and Impedanced switch need to be installed.Those tubes are stock it comes  with the kit the Volume pot and the tube sockets with pcb's are all upgrade bought from parts connexions  and knob from ebay.I tried using Sylvania,RCA and Marconi 6DN7's i could not tell the difference in terms of sound they sounds all the same to me even mixed and match i did not hear any difference(to my ears anyway).I'am really happy with this AMP the joy of working on it and the sound coming from it is very rewarding,for me at least.THANK YOU!


----------



## Uncle AL

i luvmusic 2 said:


> Yes indeed i have lots of fun soldering,I cut all the wires longer than how it should be for future modding C4S and Impedanced switch need to be installed.Those tubes are stock it comes  with the kit the Volume pot and the tube sockets with pcb's are all upgrade bought from parts connexions  and knob from ebay.I tried using Sylvania,RCA and Marconi 6DN7's i could not tell the difference in terms of sound they sounds all the same to me even mixed and match i did not hear any difference(to my ears anyway).I'am really happy with this AMP the joy of working on it and the sound coming from it is very rewarding,for me at least.THANK YOU!



Hope my order of 6HM5s and 6GU7s arrive soon. I'm guessing 6HM5 and existing EH 6H30Pi tubes will best plug-and-play option for my MK IV SE. Have considered modding LD to accept dual triode tubes, and understand from threads that improvements are substantial, even when compared to 6HM5s. I'm considering ordering adapters / tubes, but not sure which ones considered best for my LD? I'm willing to save to get best tubes for this unit. After these simple mods, may see about ordering Bottlehead S.E.X. amplifier kit.

Your thoughts on best adapter modded dual triode / power tube options for MK IV SE?


----------



## mordy

Hi uncle AL,
  
 I have not yet tried the C3g tubes. However, I am very happy with a GE 5687WA as driver and two Sylvania 6080 as power tubes. Don't know anybody else who tried this combination, but these tubes are inexpensive and IMHO well worth trying. (Sorry - no rare expensive tubes made of unobtanium, but easily obtainable for less than $20 if bought right.)


----------



## Rossliew

mikelap said:


> i ordered a couple adapters they were shipped on the 11/10/14 usually takes a month


 
 Hmm..perhaps i should just order and see how it goes.
  


superdux said:


> @rossliew
> 
> you certainly should try the 6N23P from the 70's voskhod factory, they are a dream. Especially voices sound silky and "creamy" to me.I've auditioned the grey shields 79' and the silver shield 78'.If its the same adapter MIKELAP had sold me you'd just need an 12AUX7 to 6N23P adapter to try these.


 
  
 I need to get Mike to do up an adapter for me first, eh @MIKELAP


----------



## MIKELAP

rossliew said:


> Hmm..perhaps i should just order and see how it goes.
> 
> 
> I need to get Mike to do up an adapter for me first, eh @MIKELAP


 
 You guys should look at my profile more closely what does it say next to what i do for a living .........


----------



## gibosi

bbmiller said:


> You are confusing me. According to datasheets I have been consulting 6SU7GTY uses .3 A heater current so you are all right with the amplifiers commonly talked about on this thread. But if in a new factory production you got a amplifier with 6SN7GTB in place this requires .6 A heater current exceeding heater current capabilities of the amplifiers commonly talked about in this thread, but perhaps not exceeding what is possible with the more expensive little dot amplifiers. So what amplifier are we talking about?
> 
> PS OK catching article on the web about the history of tubes you are not probably talking about new production little dot amplifiers, but probably new production tubes. So I guess you were supplying external heater current with your  new production 6SN7GTB tubes So I posted a stupid question sorry.


 
  
 It is important to distinguish between drivers and powers. Tubes used as drivers should not exceed 0.45A, and thus, the 6SU7GTY drawing 0.3A is perfectly suitable, but the 6SN7,drawing 0.6A is not without an external heater PS. Tubes used as powers should not exceed 1.0A, and thus, the 6SN7 is perfectly suitable as an output tube, requiring only a pin-adapter, but the 6AS7/6080 drawing 2.5A is not without an external heater PS.
  
 I think mab1376 does not use an external heater, so he has been using the 6SN7 exclusively as an output tube. However, while the 6SU7GTY is perfectly safe to use as a power tube, I doubt that it will sound very good. Like the 6DJ8, it likely does't run enough current to provide authoritative bass and propulsive rhythm. But to my knowledge, no one has reported using the 6SU7GTY in this way, so we will all be the wiser to hear mab1376's observations.


----------



## gibosi

uncle al said:


> Hope my order of 6HM5s and 6GU7s arrive soon. I'm guessing 6HM5 and existing EH 6H30Pi tubes will best plug-and-play option for my MK IV SE. Have considered modding LD to accept dual triode tubes, and understand from threads that improvements are substantial, even when compared to 6HM5s. I'm considering ordering adapters / tubes, but not sure which ones considered best for my LD? I'm willing to save to get best tubes for this unit. After these simple mods, may see about ordering Bottlehead S.E.X. amplifier kit.
> 
> Your thoughts on best adapter modded dual triode / power tube options for MK IV SE?


 
  
 First, I wish to emphasize all the double triodes that work in my LD1+ will work in your IV SE, as well as the II, III and unenhanced IV. All these amps are very similar with only minor differences.
  
 Secondly, everyone's ears and gear are different, so even folks with the same amp, the same headphones and the same tubes often disagree.
  
 That said, many of us find the Tung Sol and Sylvania 5687 to be excellent.
  
 The 6SN7's comprise an enormous universe, with tubes manufactured beginning in the early 1940's all the way into the 1970's, and in some cases, even into the 1980s, by manufacturers all over the world. Moreover, there are a number of companies, most in Russia and China, that are manufacturing 6SN7's today. So this tube has been continuously manufactured for 70 years now. When you search eBay for 6SN7, you will see around 3000 listings. So again, this is an enormous universe of tubes....
  
 I suggest you try a few different 6SN7's, gray-glass RCA, black-glass National Union, chrome-top Sylvania and "mouse ears" Tung Sol, to see what you like. I encourage you to seek out the earliest tubes you can afford, but as Mordy will attest, there are some very good-sounding 6SN7GTB's to be had for not much money.
  
 Further, there are a number of very informative threads devoted to this wonderful tube:
  
 http://www.head-fi.org/t/209782/the-6sn7-identification-guide
  
 http://www.head-fi.org/t/117677/the-reference-6sn7-thread
  
 http://www.head-fi.org/t/479031/6sn7-tube-addicts
  
 Have fun! 
  
 Edit: Oh, mid-1974-1979 Voskhod 6N23P's are also excellent, and they do not require an external heater PS.


----------



## Rossliew

gibosi said:


> Edit: Oh, mid-1974-1979 Voskhod 6N23P's are also excellent, and they do not require an external heater PS.


 
  
 Did you mean to use the 6N23Ps as power tubes or drivers? I tried them on my III as power tubes and to me, it didn't sound so nice. Must be the low current draw they are capable of. 6N1Ps sounded much better : )


----------



## gibosi

rossliew said:


> Did you mean to use the 6N23Ps as power tubes or drivers? I tried them on my III as power tubes and to me, it didn't sound so nice. Must be the low current draw they are capable of. 6N1Ps sounded much better : )


 
  
 It was my understanding that Uncle AL was contemplating installing the mods necessary to run double triodes as drivers, so the recommendation was to use the 6N23P as a driver. I believe everyone who has tried 6N23P (and other 0.3A tubes) as power tubes had the same experience. It appears that they do not run enough current to be effective.


----------



## Rossliew

gibosi said:


> It was my understanding that Uncle AL was contemplating installing the mods necessary to run double triodes as drivers, so the recommendation was to use the 6N23P as a driver. I believe everyone who has tried 6N23P (and other 0.3A tubes) as power tubes had the same experience. It appears that they do not run enough current to be effective.


 
 Ahh...understood. 
  
 On another note, I must report here that using 12AU7s as a driver tube is also a wonderful experience.


----------



## TrollDragon

rossliew said:


> Ahh...understood.
> 
> On another note, I must report here that using 12AU7s as a driver tube is also a wonderful experience.


 
 12AX7's and it's variants 7025/5751/ECC83/6057 etc all work very nicely as well.
  
 I am going to try a 7AU7 in a 6DJ8/6922 adapter by removing pin 9 on the tube so the heater center tap does not tied to a cathode.
 Running the 7V Heater at 6.3V will cause no issues and the 7AU7's are dirt cheap since they are not as popular as the 12AU7's.


----------



## TrollDragon

rossliew said:


> Hmm..perhaps i should just order and see how it goes.
> 
> 
> I need to get Mike to do up an adapter for me first, eh @MIKELAP


 
   
 Quote:


mikelap said:


> You guys should look at my profile more closely what does it say next to what i do for a living .........


 
  
 Which translates into *LOTS* of free time for building adapters.


----------



## mab1376

gibosi said:


> It is important to distinguish between drivers and powers. Tubes used as drivers should not exceed 0.45A, and thus, the 6SU7GTY drawing 0.3A is perfectly suitable, but the 6SN7,drawing 0.6A is not without an external heater PS. Tubes used as powers should not exceed 1.0A, and thus, the 6SN7 is perfectly suitable as an output tube, requiring only a pin-adapter, but the 6AS7/6080 drawing 2.5A is not without an external heater PS.
> 
> I think mab1376 does not use an external heater, so he has been using the 6SN7 exclusively as an output tube. However, while the 6SU7GTY is perfectly safe to use as a power tube, I doubt that it will sound very good. Like the 6DJ8, it likely does't run enough current to provide authoritative bass and propulsive rhythm. But to my knowledge, no one has reported using the 6SU7GTY in this way, so we will all be the wiser to hear mab1376's observations.


 
  
 I currently use the c3g as a driver tube and 6SN7 as power tube without external heaters, the 6su7 has a much lower requirement on heater current but overall very similar construction to the 6SN7.
  
 I'm hoping it can add a similar sound as it did when i used a single 6su7 as a driver with an external heater.


----------



## TrollDragon

acapella11 said:


> Hey TD, if you do not want to jump onto the bandwagon of alternative driver tubes with adapters but the best in sound you can get, classically, the high budget pre-1984 6H30P-DR might come handy. Just saying ...


 
 I really don't know anyone in their right mind who would spend that kind of dosh on a pair of those tubes...
 http://www.ebay.ca/itm/2x-MATCHED-6N30P-DR-NIB-OTK-1987-Military-Grade-TUBES-Hi-Fi-AUDIO-PAIR-6-30-/251676954041
  
 That kind on money would put a Yaqin nicely on my desktop.


----------



## i luvmusic 2

uncle al said:


> i luvmusic 2 said:
> 
> 
> > Yes indeed i have lots of fun soldering,I cut all the wires longer than how it should be for future modding C4S and Impedanced switch need to be installed.Those tubes are stock it comes  with the kit the Volume pot and the tube sockets with pcb's are all upgrade bought from parts connexions  and knob from ebay.I tried using Sylvania,RCA and Marconi 6DN7's i could not tell the difference in terms of sound they sounds all the same to me even mixed and match i did not hear any difference(to my ears anyway).I'am really happy with this AMP the joy of working on it and the sound coming from it is very rewarding,for me at least.THANK YOU!
> ...


 
 I like using  6AS7G's(WARNING!6AS7G is not recommended it's just me taking chances) and 6SN7's for power tubes and for driver tubes i used Chatham 6AS7G and Various 6SN7's.


----------



## i luvmusic 2

trolldragon said:


> acapella11 said:
> 
> 
> > Hey TD, if you do not want to jump onto the bandwagon of alternative driver tubes with adapters but the best in sound you can get, classically, the high budget pre-1984 6H30P-DR might come handy. Just saying ...
> ...


 
 One of us here will(but not me)for that $ i will asked GLEN to build me an amp...........
	

	
	
		
		

		
		
	


	




 
  
 But i don't have the $$$$$$.


----------



## TrollDragon

i luvmusic 2 said:


> One of us here will(but not me)for that $ i will asked GLEN to build me an amp...........
> 
> 
> 
> ...


 
  
 I don't think that $800 will buy you a 2359glenn amp, but I could be wrong...


----------



## Uncle AL

mab1376 said:


> I currently use the c3g as a driver tube and 6SN7 as power tube without external heaters, the 6su7 has a much lower requirement on heater current but overall very similar construction to the 6SN7.
> 
> I'm hoping it can add a similar sound as it did when i used a single 6su7 as a driver with an external heater.



How well does this C3G and 6SN7 combination work for you? How might sound quality 63G and 6SN7 compare to say, plug-in-play 6HM5 / 6H30Pi combination? There was discussion in another thread of using a C3G adapter and different tube other than C3G for drivers and 6SN7 for power tubes, but cannot find my notes from that thread. Your thoughts..?


----------



## gibosi

trolldragon said:


> I don't think that $800 will buy you a 2359glenn amp, but I could be wrong...


 
  
 Last spring, his basic amp was going for $650 plus shipping....


----------



## MIKELAP

trolldragon said:


> I really don't know anyone in their right mind who would spend that kind of dosh on a pair of those tubes...
> http://www.ebay.ca/itm/2x-MATCHED-6N30P-DR-NIB-OTK-1987-Military-Grade-TUBES-Hi-Fi-AUDIO-PAIR-6-30-/251676954041
> 
> That kind on money would put a Yaqin nicely on my desktop.


 
 Prices are going up up up crazy !


----------



## i luvmusic 2

trolldragon said:


> i luvmusic 2 said:
> 
> 
> > One of us here will(but not me)for that $ i will asked GLEN to build me an amp...........
> ...


 
 Ok then i will do another BH kit.....
  
 At the moment i don't think i will need another amp for awhile the MK III and the CRACK is really nice.The SEX is much better and it can drive all of the HP that i have very well.


----------



## TrollDragon

gibosi said:


> Last spring, his basic amp was going for $650 plus shipping....


 
 Well that is a very reasonable price. What features,options and tubes does that include?
  
  


mikelap said:


> Prices are going up up up crazy !


 
 Yeah I know, I'd love to have a master case of those to sell on eBay...


----------



## Uncle AL

i luvmusic 2 said:


> Ok then i will do another BH kit.....
> 
> At the moment i don't think i will need another amp for awhile the MK III and the CRACK is really nice.The SEX is much better and it can drive all of the HP that i have very well.



Is your new BH SEX even better than your LD amps even after modding?


----------



## i luvmusic 2

uncle al said:


> i luvmusic 2 said:
> 
> 
> > Ok then i will do another BH kit.....
> ...


 
 YES it's a night and Day difference.Think of these make the LD have deeper bass bigger/wider soundstage and if you need more bass than the SEX the CRACK will take care of that.


----------



## gibosi

trolldragon said:


> Well that is a very reasonable price. What features,options and tubes does that include?


 
  
 One rectifier - 3DG4, 5AW4 and other 5 Volt rectifiers that can provide at least 250ma.
 Two output - 6AS7 and all the variants, as well as the 6336, and
 One driver - octal 6SN7. And of course, with pin adapters, many others 
  
 As of last spring he included three rectifier tubes with the amp, two 3DG4 and 5AW4. However, I am not sure if he provides output and drivers.
  
 (kvtaco17 posted this pic in another thread)


----------



## Uncle AL

i luvmusic 2 said:


> I like using  6AS7G's(WARNING!6AS7G is not recommended it's just me taking chances) and 6SN7's for power tubes and for driver tubes i used Chatham 6AS7G and Various 6SN7's.


 
 Thanks-- Regarding the 6AS7G, you suggested, (with warning), the use of the 6AS7G for both power =and= driver tubes?  Isn't the current too high for use as a driver tube? I believe Woo Audio uses this tube successfully in their amps, but unsure about LD circuit enabling 6AS7G use for driver tubes?  Clarification...?


----------



## i luvmusic 2

uncle al said:


> i luvmusic 2 said:
> 
> 
> > I like using  6AS7G's(WARNING!6AS7G is not recommended it's just me taking chances) and 6SN7's for power tubes and for driver tubes i used Chatham 6AS7G and Various 6SN7's.
> ...


 
  I'am sorry! i can't give you more info about using the 6AS7G it is not recommended/not safe at all.
  
 If one day this MK III dies because of me being careless it's OK i have 4 more HP amps. plus 2 DAC that can drive my HP so i'am covered for a long time.


----------



## mab1376

Just popped in the 6SU7GTY's and after literally a minute of being on the bass seems fine. Tested a new KMFDM track which is extremely bass heavy, wasn't disappointed. Gonna let em burn in over night and give more detailed feedback tomorrow.
  
 Hopefully the lower current will play nicer with my T70's


----------



## Uncle AL

i luvuic 2.. No.. I'm not pressing, and I'm not planning on rolling / modding without consderable research first, but just searching for a viable combination that would improve over 6HM5 / 6H30Pi combo.  it seems 6AS7Gs would be okay as power tubes, and possibilityTung-Sol VT-229 or 6SN7s as driver tubes. If this still poses risk, let me know, but should be safer than 6AS7Gs as driver and power tubes..


----------



## i luvmusic 2

uncle al said:


> i luvuic 2.. No.. I'm not pressing, and I'm not planning on rolling / modding without consderable research first, but just searching for a viable combination that would improve over 6HM5 / 6H30Pi combo.  it seems 6AS7Gs would be okay as power tubes, and possibilityTung-Sol VT-229 or 6SN7s as driver tubes. If this still poses risk, let me know, but should be safer than 6AS7Gs as driver and power tubes..


 
  No worries,The 6AS7G is too much current for the LD MK amps,It requires external power supply for the heaters and it heats up the amp,Some of us here used fans to cool it down.Anyway you used the 6AS7G(for power or driver) it is a RISK.I suggest try the 6SN7's for power and driver,IMO they are better than the stock power tubes and 6HM5's combo.


----------



## gibosi

uncle al said:


> Thanks-- Regarding the 6AS7G, you suggested, (with warning), the use of the 6AS7G for both power =and= driver tubes?  Isn't the current too high for use as a driver tube? I believe Woo Audio uses this tube successfully in their amps, but unsure about LD circuit enabling 6AS7G use for driver tubes?  Clarification...?


 
  
 While ILM2 likes a 6AS7 as a driver tube, using it as such is very unusual. However, it appears that as long as you can provide the 2.5 amps it needs with an external heater power supply, it does work. Where the 6AS7 excels is as an output tube. It has a very low plate resistance and as a consequence, it is the most common output tube used in OTL (Output TransformerLess) amps. As you noted, Woo and other manufacturers use it in this way. And in this forum, Mordy, Hypnos1 and perhaps others are also using them as power tubes in their LD's with very good results.
  
 My advice is to stick with the lower power double triode signal tubes as drivers. And after you have become comfortable using external heater power supplies for driver tubes, it won't seem like such a stretch to do the same for your power tubes.


----------



## JazzVinyl

Anyone repaired a "happydiy998" c3g to 6AK5 socket adapter? After the "long wait" one of mine arrived not working.

I see they are using the pin section of a regular tube (looks like they break the tube to be able to use the bottom portion with the pins) and then run wires to the loctal socket on top.

Probably easy enough to find the problem wire and fix by soldering....

If I could figure out how the round brass cover between the pin section and loctal socket above, was attached....anyone know?

Appreciate....


----------



## gibosi

Looking at my adapters, I suspect that some kind of glue or epoxy was used. Trying to pry them apart might get pretty ugly, but while you are waiting for a replacement, it might be worth a try. lol


----------



## JazzVinyl

They want me to mail the bad one back to China, but I hardly see the point and waiting for mine to arrive before they sent a replacement.....no good.

Sure wish I had gotten a working pair to begin with!!!! Don't they QA their own work?





gibosi said:


> Looking at my adapters, I suspect that some kind of glue or epoxy was used. Trying to pry them apart might get pretty ugly, but while you are waiting for a replacement, it might be worth a try. lol


----------



## gibosi

I'm surprised! I seem to remember that others who have received defective adapters from happydiy9981 had no trouble getting replacements. I suggest that you keep bothering them. It is absurd to expect you to waste good money to send a defective adapter back to China. And of course, it wouldn't hurt to remind them that your positive feedback depends on it.
  
 Good luck!


----------



## JazzVinyl

They also never gave me my feedback! I paid immediately and owe them nothing further, I should have received my feedback weeks ago.

I did ask them to leave my feedback, but they have not done so.




gibosi said:


> I'm surprised! I seem to remember that others who have received defective adapters from happydiy9981 had no trouble getting replacements. I suggest that you keep bothering them. It is absurd to expect you to waste good money to send a defective adapter back to China. And of course, it wouldn't hurt to remind them that your positive feedback depends on it.
> 
> Good luck!


----------



## MIKELAP

jazzvinyl said:


> They want me to mail the bad one back to China, but I hardly see the point and waiting for mine to arrive before they sent a replacement.....no good.
> 
> Sure wish I had gotten a working pair to begin with!!!! Don't they QA their own work?


 
 I had problems with his adapters once or twice they never asked me to send it back , there must be somebody  in North America that does these adapters.


----------



## Rossliew

Anyone has a spare pair of C3G adapters to sell? Need one as i don't think I'm receiving stuff from China. Their customs are taking their sweet time holding up packages for export.


----------



## sgbwill2

Hello again, I recently purchased a NOS pair of RCA 6as7's and am running them with the c3g's without external heaters with my LD MKIII. I was previously using 6sn7 and 6f8g's which sounded great but with low impedance headphones I was getting major distortion in the base. now I have switched to the 6as7's the distortion has completely gone. I thought the c3g's were causing the distortion but surprisingly it was the 6sn7's. Thought I would just post this update so that if anyone is getting distortion with low impedance headphones with the LD MK III with the same set up it is most likely the 6sn7's causing the distortion. Hopefully the 6as7's will be fine without external heaters i will keep a close eye on the amps heat. so far seems to be fine though. I can now finally use my denon 5k's with the LD yay.


----------



## gibosi

sgbwill2 said:


> Hello again, I recently purchased a NOS pair of RCA 6as7's and am running them with the c3g's without external heaters with my LD MKIII. I was previously using 6sn7 and 6f8g's which sounded great but with low impedance headphones I was getting major distortion in the base. now I have switched to the 6as7's the distortion has completely gone. I thought the c3g's were causing the distortion but surprisingly it was the 6sn7's. Thought I would just post this update so that if anyone is getting distortion with low impedance headphones with the LD MK III with the same set up it is most likely the 6sn7's causing the distortion. Hopefully the 6as7's will be fine without external heaters i will keep a close eye on the amps heat. so far seems to be fine though. I can now finally use my denon 5k's with the LD yay.


 
  
 Running 6AS7's without external heaters is living very, very dangerously.....  A pair of 6AS7's draw 5.0A which far exceeds the current draw the transformer in the LD III was designed for.


----------



## sgbwill2

gibosi said:


> Running 6AS7's without external heaters is living very, very dangerously.....  A pair of 6AS7's draw 5.0A which far exceeds the current draw the transformer in the LD III was designed for.


 
 Yes I agree after further listening the transformer has began to get rather warm. it is best i switch back to the 6f8g's for the time being


----------



## sgbwill2

Sorry for the double post but does anyone know the transformer output for the LD MK III?


----------



## gibosi

sgbwill2 said:


> Yes I agree after further listening the transformer has began to get rather warm. it is best i switch back to the 6f8g's for the time being


 
  
 Mordy provided a great explanation with pictures on how to set up external heater power supply to run 6AS7's. Now that you know how good these tubes can sound with your headphones, I hope you will agree that it might well be worth the extra time and expense. 
  
 Or you might want to try a pair of 7044 or 5687. These have 0.9A heaters, which is 1.5 times a 6SN7, so they just might work fairly well with low Z phones. But I don't know that anyone else has tried them....


----------



## TrollDragon

sgbwill2 said:


> Sorry for the double post but does anyone know the transformer output for the LD MK III?


 
  
 If it is the same as the MK IV which I think it is since the model name of mine is MK-III.

 The 6.8V @ 2.5A is the output tube heater supply.


----------



## MIKELAP

trolldragon said:


> If it is the same as the MK IV which I think it is since the model name of mine is MK-III.
> 
> The 6.8V @ 2.5A is the output tube heater supply.


 
 This picture is never far away if i would have a $ everytime i saw this  picture...........


----------



## mab1376

sgbwill2 said:


> Hello again, I recently purchased a NOS pair of RCA 6as7's and am running them with the c3g's without external heaters with my LD MKIII. I was previously using 6sn7 and 6f8g's which sounded great but with low impedance headphones I was getting major distortion in the base. now I have switched to the 6as7's the distortion has completely gone. I thought the c3g's were causing the distortion but surprisingly it was the 6sn7's. Thought I would just post this update so that if anyone is getting distortion with low impedance headphones with the LD MK III with the same set up it is most likely the 6sn7's causing the distortion. Hopefully the 6as7's will be fine without external heaters i will keep a close eye on the amps heat. so far seems to be fine though. I can now finally use my denon 5k's with the LD yay.


 
 I haven't confirmed yet, but the 6SL7 might work better for more sensitive headphones.
  
 so far sounds good on my HD650's, hopefully my T70's like them as much.


----------



## hypnos1

jazzvinyl said:


> They want me to mail the bad one back to China, but I hardly see the point and waiting for mine to arrive before they sent a replacement.....no good.
> 
> Sure wish I had gotten a working pair to begin with!!!! Don't they QA their own work?


 

 Hi JV.
  
 I am SOOO sorry these "Happy??!! DIY people are creating such agony for a good few people now...it just shouldn't happen - it's hardly rocket science, for goodness sake! These were some of the early adapters I had a go at myself, never having done anything like that before and they're still working perfectly, lol! So there's NO excuse for the pros!!...(Especially what they charge!).
  
 I'm only sorry I can't get down to a pictorial on making one yourselves just now, but I shall be ASAP. With basic soldering skills and a bit of care (and patience!), it's not TOO difficult and is immensely rewarding...so for even those whose adapters are 'working!' at present, it just might be a worthwhile option for the future, from the look of things!! 
	

	
	
		
		

		
			





...(Must get my skates on 
	

	
	
		
		

		
		
	


	




).
  
 In the meantime impress upon them that they are biting the hand that feeds them BIG TIME!!...And keep on at them until you get a better response...GOOD LUCK!


----------



## CITIZENLIN

sgbwill2 said:


> Hello again, I recently purchased a NOS pair of RCA 6as7's and am running them with the c3g's without external heaters with my LD MKIII. I was previously using 6sn7 and 6f8g's which sounded great but with low impedance headphones I was getting major distortion in the base. now I have switched to the 6as7's the distortion has completely gone. I thought the c3g's were causing the distortion but surprisingly it was the 6sn7's. Thought I would just post this update so that if anyone is getting distortion with low impedance headphones with the LD MK III with the same set up it is most likely the 6sn7's causing the distortion. Hopefully the 6as7's will be fine without external heaters i will keep a close eye on the amps heat. so far seems to be fine though. I can now finally use my denon 5k's with the LD yay.



 


Hi, sgbwill2

When I listen to LD MK IV with westone 3 ime or shure 535, I do get some distortion. Does not work well with low impedance headphones or IME.


----------



## CITIZENLIN

jazzvinyl said:


> Anyone repaired a "happydiy998" c3g to 6AK5 socket adapter? After the "long wait" one of mine arrived not working.
> 
> 
> 
> ...



 


I bought mine from the same seller and only one out of 2 were good but they sent me replacement. I had to stay on their case and they did send me replacement with DHL (only took a week to get replacement) stay on them. Good luck


----------



## JazzVinyl

Not rocket science, indeed!

At looking at my two closer...I can see the one that works, has been epoxied at the lip where there loctal socket joins the brass ring. On the one that does not work, there is no visible epoxy. Also see some marks at the top of the brass ring on the non working example.

So, rather looks to me like they had this one apart a few times, trying to get the continuity 100%. Seems an incredibly simple process to check continuity, there is no excuse to ship one that has a continuity problem!!

I have contacted the seller again, and pointed out that citizenlin also got one of his two that was bad and they they sent him a replacement via DHL, and requested they provide me with the same level of service, and that I would mail back the bad one after receiving a working replacement.

Again, asked them to leave my feedback....

Appreciate the thoughts here , from the head-fi crowd....






hypnos1 said:


> Hi JV.
> 
> I am SOOO sorry these "Happy??!! DIY people are creating such agony for a good few people now...it just shouldn't happen - it's hardly rocket science, for goodness sake! These were some of the early adapters I had a go at myself, never having done anything like that before and they're still working perfectly, lol! So there's NO excuse for the pros!!...(Especially what they charge!).
> 
> ...


----------



## Uncle AL

With reports of adapter failures from overseas suppliers, does anyone have a source that is more consistent in quality? I'd even be willing to pay a bit more, if I knew they were quality. I noticed an ad by, "Vacuum Tubes, Inc.", but would be interested in feedback from others in this thread...


----------



## Rossliew

I am listening to the LD3 with the following combo of tubes :
  
 12AU7 (with adapters) - driver tube
 Russian 6N23Ps - power tubes
  
 All I can say is WOW! Despite the low current draw of the 6N23P, as a combo with the 12AU7, the overall sound is full bodied, holographic with wide sound staging. All this with a HD600. I continue to be impressed by the LD3 and I can't wait for the 6DJ8 adapter to be done and i can roll some of them to see how they fare against the 12AU7s.


----------



## i luvmusic 2

If you can DIY that is the best quality adapter you can get.


----------



## JazzVinyl

Well Folks...after contacting "happydiy998" again and stating my interest in getting a replacement adapter sent via DHL....here is the response I got:
  
  
 =======
Hello,

 yes, please ship back the broken one, we will test, if the problem is there, we will ship one adapter to you by DHL,

 this is our shipping address: Ms. Tse Yuk Chi, Shop 20, G/Fl., Fullview Garden Shopping Centre, 18 Siu Sai Wan Road, Hong Kong. 00852 92166680,

 Thanks&Best Regards,
 Vanessa"​ =======
  
  
 And after FOUR REQUESTS....that STILL have NOT left my positive feedback!! 
  
 This seller clearly engages in "feedback extortion" practices!!!!
  
 Paint me: REALLY REALLY PISSED!!!!
  
  
 --JV
  
  
 Quote:


uncle al said:


> With reports of adapter failures from overseas suppliers, does anyone have a source that is more consistent in quality? I'd even be willing to pay a bit more, if I knew they were quality. I noticed an ad by, "Vacuum Tubes, Inc.", but would be interested in feedback from others in this thread...


----------



## i luvmusic 2

jazzvinyl said:


> Well Folks...after contacting "happydiy998" again and stating my interest in getting a replacement adapter sent via DHL....here is the response I got:
> 
> 
> =======
> ...


 
 Had a problem with them too,sent me a wrong materials but i took care of it very well leaved a BAD and nasty negative feedback.THEY CRIED LIKE A BABY after that.


----------



## stvn758

http://www.ebay.co.uk/itm/2x-Matched-Voskhod-Gold-pins-Gold-grid-6ZH1P-EV-6AK5-EF95-403B-5654-6J1-1975-NIB-/111486106781?pt=Vintage_Electronics_R2&hash=item19f516fc9d
  
  
 I just bought these mostly because of the write up at the start of this thread. These are an upgrade from the stock ones and I will be impressed, won't I?


----------



## TrollDragon

stvn758 said:


> http://www.ebay.co.uk/itm/2x-Matched-Voskhod-Gold-pins-Gold-grid-6ZH1P-EV-6AK5-EF95-403B-5654-6J1-1975-NIB-/111486106781?pt=Vintage_Electronics_R2&hash=item19f516fc9d
> 
> 
> I just bought these mostly because of the write up at the start of this thread. These are an upgrade from the stock ones and *I will be impressed, won't I?  *


 
  
 Wow those are expensive...
  
 Probably not as much as a pair of these for $10 or $12 shipped with the "Make Offer" deal.
 http://www.ebay.com/itm/6HM5-6HA5-EC900-export-quality-audio-triode-tube-NOS-FREE-SHIPPING-/300879467071


----------



## stvn758

trolldragon said:


> Wow those are expensive...
> 
> Probably not as much as a pair of these for $10 or $12 shipped with the "Make Offer" deal.
> http://www.ebay.com/itm/6HM5-6HA5-EC900-export-quality-audio-triode-tube-NOS-FREE-SHIPPING-/300879467071


 

 See all these numbers confuse me, I also assumed as in most products expensive equals better (within reason). Are they the same tube?
  
 How much are the stock tubes worth then, pennies?


----------



## TrollDragon

stvn758 said:


> See all these numbers confuse me, I also assumed as in most products expensive equals better (within reason). Are they the same tube?
> 
> How much are the stock tubes worth then, pennies?


 

 With all the new popularity of tubes these days it is a sellers market on eBay and they get to dictate the prices, more expensive isn't necessarily better in the tube rolling game.
 "Matched" is a red flag word to look out for as the LD I+/II/III/IV DO NOT require matched tubes and will not benefit from them. It is a way the seller can get more money for the tubes.
  
 The stock LD MK III & IV tubes (GE 5654W) can be had for 55 cents a piece if you win this auction...
 http://www.ebay.com/itm/100-PIECES-NOS-NIB-GENERAL-ELECTRIC-6AK5W-5654-6AK5-403-A-6J1-AMP-VINTAGE-TUBES-/271638933330
  
 That is a small private auction, I do believe there are other suppliers who sell tubes in bulk/wholesale only and don't list on eBay. With those suppliers you could probably pick up a thousand lot for 25 cents a piece...
  
 This thread can be overwhelming with all the info, there is a table on page 77 that shows all the stock replacement tubes that have been tried. One of the best tubes for an unmodified LD is the 6HM5`s I linked, other than that you will need to get into double triodes and octal tubes with adapters and possibly external power supplies...


----------



## MIKELAP

i bought these 10 for $39.00 if your interested just make shure to tell him to pack them well.   That's $3.90 each now that's a deal.                                                                                                                                                                                                                                                                                            http://www.ebay.com/itm/251609948341?_trksid=p2059210.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT


----------



## TrollDragon

mikelap said:


> i bought these 10 for $39.00 if your interested just make shure to tell him to pack them well.   That's $3.90 each now that's a deal.                                                                                                                                                                                                                                                                                            http://www.ebay.com/itm/251609948341?_trksid=p2059210.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT


 

 A most excellent deal!


----------



## stvn758

trolldragon said:


> With all the new popularity of tubes these days it is a sellers market on eBay and they get to dictate the prices, more expensive isn't necessarily better in the tube rolling game.
> "Matched" is a red flag word to look out for as the LD I+/II/III/IV DO NOT require matched tubes and will not benefit from them. It is a way the seller can get more money for the tubes.
> 
> The stock LD MK III & IV tubes (GE 5654W) can be had for 55 cents a piece if you win this auction...
> ...


 

 Thanks, I'll have a look at that page. Was interested in the Mullards but in the Little Dot manual it said some people had experienced distortion with them, so gave them a miss.


----------



## JazzVinyl

"HappyDIY998" engages in "Feedback Extortion"!!
  
 The last message to me, from them:
  
 ====
Hello,

 Dear sir, if you say like this, we are willing to refund you the payment fully and not sell this adapter anymore, I do not know what that buyer told you, you can find that we want to solve the problem, if you leave us positive feedback, you will get the same, if you leave negative, we can not control you, please keep in mind, we are the honest seller who want to solve the problem,

 now we can tell you one way, we will refund you payment fully if you leave positive feedback, or if you have any suggestions, please tell us, we are waiting for your reply,

 Thanks&Best Regards,
 Vanessa​ ====


----------



## Uncle AL

Sorry about your continued problems, "JazzVinyl". If through eBay there is recourse (eBay / PayPal), but may not result in positive feedback. Amazon has more influence to obtain restitution for problems. Other transactions where a credit card was used, permit you to file dispute with your bank for goods not received (or non-functional). Problems with adapters may have prompted headf-fiers to go the DIY route.

If any fellow head-fiers have had good experience with a supplier of vacuum tube/valve adapters can you please let us know?


----------



## TrollDragon

Really too bad they are the only builder of the C3G to 6AK5 adapter.
 I didn't like it the moment I saw the chopped off B7G tube as part of the build,  that is something I would do and not expect it from a commercial seller.
  
 Report them to eBay about the full Refund "IF" Positive feedback. Leave them Negative Feedback and file a PayPal claim against them.
  
 Then tear the bad adapter apart and fix it yourself.


----------



## Uncle AL

I don't believe eBay will tolerate Seller extortion. If it was me, I would file with eBay to assure the Seller follows thru with their promise to refund your amount, and suggest in your dispute filing, that you be reimbursed for shipping. Once resolved, you can leave feedback, noting that you received a non-functional adapter from the Seller. Either way, I would doubt Seller intent to leave positive feedback...


----------



## JazzVinyl

Yes, I don't think there is any hope for getting this seller "happydiy998" to understand he owes me a working C3g to 6AK5 adapter.
  
 I will report them for Feedback Extortion, as they are clearly guilty.
  
 And I _do_ want to tear apart and fix it...the question is:  How the heck does it come apart?  I have been inspecting it with a Lupe, but I don't see a way in.  And it does appear that it would be pretty easy to break the glass "chopped off B7G" portion of the adapter...
  
 Any ideas on how to get it apart, guys???
  
  
  
 Quote:


trolldragon said:


> Really too bad they are the only builder of the C3G to 6AK5 adapter.
> I didn't like it the moment I saw the chopped off B7G tube as part of the build,  that is something I would do and not expect it from a commercial seller.
> 
> Report them to eBay about the full Refund "IF" Positive feedback. Leave them Negative Feedback and file a PayPal claim against them.
> ...


----------



## gibosi

trolldragon said:


> Really too bad they are the only builder of the C3G to 6AK5 adapter.


 
  
 I seem to recall that one of our posters contacted happydiy998 and asked them to make this adapter, which they did. So it is certainly possible that if asked, another manufacturer might be willing to make them, as well.


----------



## Acapella11

trolldragon said:


> I don't think that $800 will buy you a 2359glenn amp, but I could be wrong...


----------



## Acapella11

$212 last year's June for a matched pair of 6H30P-DR incl. shipping from Russia. 
Sorry for answering with two posts, mobile editing mistake.


----------



## MIKELAP

>


 From what i heard they start at $650.00.


----------



## gibosi

Finally managed to snag an early Tung-Sol 5687.
  
 In both pictures, 1956 on the left and 1952 on the right. Notice the flat black ladder plates on the earlier tube.
  

  
 Haven't had time to do any comparisons, but after a couple hours, it certainly seems to be a terrific tube.


----------



## bbmiller

trolldragon said:


> stvn758 said:
> 
> 
> > See all these numbers confuse me, I also assumed as in most products expensive equals better (within reason). Are they the same tube?
> ...


 
 I'm I right in thinking that  page 77 table is only for driving tubes? Has anybody assembled such a table the power tubes?

 What is the process for Figuring out what power tubes are compatible for yourself?


----------



## stvn758

bbmiller said:


> I'm I right in thinking that  page 77 stable is only for driving tubes? Has anybody assembled such a table the power tubes?
> 
> What is the process for for agreeing out what power tubes are compatible for yourself?


 
 Check the manual for your amp. From what I gathered browsing this thread the power tubes have a lesser effect on the sound of the amp.


----------



## TrollDragon

I'ma no read english too a good sometime...


----------



## TrollDragon

jazzvinyl said:


>


 
 Here is a little tip, when you respond above quoted text instead of below, the next person can't quote your reply as nothing ends up in the quote box.
  
 Looks like the C3g to 6AK5 adapters have been pulled from eBay as there are none to be found...
 Aliexpress has them but they look like the same poorly made product from happydiy998 and most likely are.
  
 They definitely look to be epoxied, if you could pop out that greenish piece of circuit board, you might be able to push the innards out and examine them.

 Might get lucky and find out it's only hot glue encasing the insides...


----------



## MIKELAP

bbmiller said:


> I'm I right in thinking that  page 77 table is only for driving tubes? Has anybody assembled such a table the power tubes?
> 
> What is the process for Figuring out what power tubes are compatible for yourself?


 
 Quote:


mordy said:


> Some time ago we compared various power tubes for the LD MKIII. 6N6P, 6N6Pi, 6N6P-IR and 6H30-DR. The last two were the best, the IR tube being a best buy. However, what distinguished one tube over another was the bass detail and punch, and nobody mentioned how neutral sounding the tube was.


----------



## gibosi

bbmiller said:


> I'm I right in thinking that  page 77 table is only for driving tubes? Has anybody assembled such a table the power tubes?
> 
> What is the process for Figuring out what power tubes are compatible for yourself?


 
  
 To my knowledge, no one has put together such a table. In order to figure out for yourself, the most important factors are
  
 1) Double triode
 2) Separate cathodes (there are some double triodes such as the E90CC where the triodes "share" a cathode. These will not work.)
 3) Heater current 1.0A or less
 4) 6.3 Volts
  
 I think that is about it, but if I am overlooking something, I am sure someone will let me know. 
  
 If the tube is not pin-compatible with the 6DJ8 and 6N30P, it should be a simple matter to purchase or make an adapter. For example, the 6SN7.
  
 Have fun! 
  
 Edit: added 4)


----------



## bbmiller

gibosi said:


> If the tube is not pin-compatible with the 6DJ8 and 6N30P, it should be a simple matter to purchase or make an adapter. For example, the 6SN7.
> 
> Have fun!


 
 Are there any databases which lets you search for tubes by pin arrangement? Do pin arrangements of vacuum tubes have names that can be search for in any way? On the Internet? On a page itself if you search for the recognizable pin arrangement name, say in certain very good datasheets?
  
 What "are the to and from tube names" that are iconic for certain pin arrangement conversions adapters which are already made? Are there ones which are important for a little dot IV amplifier which haven't been mentioned on this thread?


----------



## JazzVinyl

trolldragon said:


> Here is a little tip, when you respond above quoted text instead of below, the next person can't quote your reply as nothing ends up in the quote box.
> 
> Looks like the C3g to 6AK5 adapters have been pulled from eBay as there are none to be found...
> Aliexpress has them but they look like the same poorly made product from happydiy998 and most likely are.
> ...




Yes, happydiy988 said he would no longer offer them, in one of his ugly responses to me...

And I have been trying to get the green circuit board out, but so far no luck. 

Will keep trying and appreciate ANY help....


----------



## mordy

Hi JV,
  
 Some time ago I won an item from a Chinese seller for a 1/4 of the going price. The seller did not want to sell the item, stating that he was new to EBay. Called EBay and asked them about the rules. They told me that the seller is obligated to honor the price. After communicating this and mentioning that I would like to leave good feedback, everything was peaches and cream from the seller and no further problems.
  
 Suggest that you go to EBay's Resolution Center and find the phone# to contact them. Tell them your story and ask how to proceed.
  
 http://res.ebay.com/ws/eBayISAPI.dll?ResolutionCenter
  
 If you payed via Pay Pal they may also be able to offer assistance in recovering your money etc. Finally, if you used a credit card, the credit card company may also be able to help you, although foreign purchases are much harder to deal with than domestic.
  
 Good luck!
  
 This Chinese seller has thousands of items for sale and cannot afford bad publicity/feedback.


----------



## gibosi

bbmiller said:


> Are there any databases which lets you search for tubes by pin arrangement? Do pin arrangements of vacuum tubes have names that can be search for in any way? On the Internet? On a page itself if you search for the recognizable pin arrangement name, say in certain very good datasheets?
> 
> What "are the to and from tube names" that are iconic for certain pin arrangement conversions adapters which are already made? Are there ones which are important for a little dot IV amplifier which haven't been mentioned on this thread?


 
  
 If there are such databases, I sure don't know about them... But wouldn't that be great!
  
 And I am unaware of any names that there might be for the different pin arrangements. I am quite sure that all double triodes using the octal base since about 1940 have the same pin-out, the same as a 6SN7, so that one is easy. There is a small group of 8-pin all-glass miniatures, Rimbase ECC40. These are essentially an all-glass miniature European version of the 6SN7/ECC32. For 9-pin all-glass miniature double triodes, I am aware of 4 different pin-outs: The 6DJ8 pin-out appears to be the most common. And then the 12AU7 pin-out, the 5687 pin-out and finally the 2C51/396A. If there are others, I either can't think of them, or have yet to encounter them.....
  
 Among the octals, the 6SN7, of course, and with external heater PS, the 6BL7. 6BX7 and 6AS7.
  
 Among the 8-pin all-glass miniatures, Rimlock base tubes, the ECC40, with 0.6A heaters might be worth trying....
  
 Among the 6DJ8 pin-out, perhaps the stock LD tubes are the most common.
  
 Among the 12AU7 pinout, most are 0.3amps or less, so maybe not many good candidates for power tubes. However, there is the Brimar 13D3, with 0.65A (6.3V) heaters, which might be worth trying. Also, the E80CC, with 0.6A heaters (6.3V)
  
 Among the 5687 pinout, in addition to the 5687, there is the 7044 (0.9A) and the 7119/E182CC (0.64A)
  
 Among the 2C51/396A, I know only of that one tube, 0.3A heaters, probably not a good candidate.
  
 If others have more to add, please do so.....
  
 Edit: Added the E80CC


----------



## JazzVinyl

mordy said:


> Hi JV,
> 
> Some time ago I won an item from a Chinese seller for a 1/4 of the going price. The seller did not want to sell the item, stating that he was new to EBay. Called EBay and asked them about the rules. They told me that the seller is obligated to honor the price. After communicating this and mentioning that I would like to leave good feedback, everything was peaches and cream from the seller and no further problems.
> 
> ...




Hello Mordy...

Yes, this Chinese seller is engaging in feedback extortion. Refuses to leave my positive feedback until after I leave him positive feedback. 

This is against Ebay policy and I fully intent to report him. He is risking being thrown off Ebay by doing this, so it's a very DUMB move on his part.

I have made some progress on disassembling the socket adapter. I did get the bottom glass pin portion out of the brass barrel. I can see that all 7 pins on the 6AK5 portion had a wire soldered on and done in good fashion. And each went to a connector on the C3g side.

I checked continuity and all sockets (save for one that has no wire connected) on the C3g side DO have continuity to a pin on the 6AK5 side.

So, this means it's wired incorrectly!!!

I will have to sit down and compare the good unit with the bad one to determine where they went wrong. 

Will keep folks here informed on what I find...will need to get the C3g side out of the brass barrel next, to be able to fix it....


----------



## bbmiller

Thanks for all that gibosi! That all may take me some time to digest.


----------



## sgbwill2

gibosi said:


> If there are such databases, I sure don't know about them... But wouldn't that be great!
> 
> And I am unaware of any names that there might be for the different pin arrangements. I am quite sure that all double triodes using the octal base since about 1940 have the same pin-out, the same as a 6SN7, so that one is easy. There is a small group of 8-pin all-glass miniatures, Rimbase ECC40. These are essentially an all-glass miniature European version of the 6SN7/ECC32. For 9-pin all-glass miniature double triodes, I am aware of 4 different pin-outs: The 6DJ8 pin-out appears to be the most common. And then the 12AU7 pin-out, the 5687 pin-out and finally the 2C51/396A. If there are others, I either can't think of them, or have yet to encounter them.....
> 
> ...


 
 Thanks for this post as I am currently contemplating replacing the 6sn7's due to the distortion yet dont want to fit external heaters for the 6as7's yet. As for the 7044 and 5687's radiomuseum data sheets list them both as 0.45A. is this the case? If so and there are 0.9A versions how do i distinguish the two? thanks.


----------



## Uncle AL

Hey, "sgbwill2", Since I'm considering adapting my next LD amp to use 6SN7s, drivers and power tubes, can you share more specifics on distortion you're experiencing? I've heard this mentioned but no specifics. As I wait, I plan to try 6HM5 / 6H30Pi combo..


----------



## sgbwill2

uncle al said:


> Hey, "sgbwill2", Since I'm considering adapting my next LD amp to use 6SN7s, drivers and power tubes, can you share more specifics on distortion you're experiencing? I've heard this mentioned but no specifics. As I wait, I plan to try 6HM5 / 6H30Pi combo..


 
 When using relatively high impedance headphones such as the sennheiser hd 650 i dont experience any distortion with my LD MK III however when i switch to low impedance headphones such as my dennon 5k's it is un-listenable as the base distorts massively. If your headphone collection solely includes high impedance headphones you should be ok but if you plan on listening to low impedance headphones out of your LD as well i wouldn't recommend it.


----------



## Uncle AL

sgbwill2 said:


> When using relatively high impedance headphones such as the sennheiser hd 650 i dont experience any distortion with my LD MK III however when i switch to low impedance headphones such as my dennon 5k's it is un-listenable as the base distorts massively. If your headphone collection solely includes high impedance headphones you should be ok but if you plan on listening to low impedance headphones out of your LD as well i wouldn't recommend it.



Thanks-- I'm almost exclusively using high impedance headphones with my MK IV SE, and using lower impedance headphones (Q701, PX100) with one of three SS amps. I get that the 6SN7s produce richer bass than the 6HM5s, but how are the mids and highs of the 6SN7s, say with HD650s, HD800 or DT880 / 990 cans?


----------



## gibosi

sgbwill2 said:


> Thanks for this post as I am currently contemplating replacing the 6sn7's due to the distortion yet dont want to fit external heaters for the 6as7's yet. As for the 7044 and 5687's radiomuseum data sheets list them both as 0.45A. is this the case? If so and there are 0.9A versions how do i distinguish the two? thanks.


 
  
 These tubes are similar to the 12AU7 in that they can be configured to operate in either a 6.3 volt or 12.6 volt circuit. In 12.6 volt circuits, they draw 0.45A and in 6.3 volt circuits, they draw 0.9A. As the LD employs a 6.3 circuit, these tubes will draw 0.9A. You will need an adapter configured to use them in 6.3 volt circuits:
  
 http://www.ebay.com/itm/1x-5687-to-6N6-6N1-6N2-6N6-6N11-ECC88-E88CC-Vacuum-tube-adapter-socket-converter-/321472393335?


----------



## Uncle AL

"Rossliew", Appreciated your much earlier WOW! post about near holographic audio from combination of 12AU7 / 6N23P combo with your LD MK III. I'm transitioning through several combinations including 6HM5 / 6H30Pi and possibility 6SN7s. Can you compare 12AU7 / 6N23P combo to 6SN7s in audio quality / soundstage?


----------



## gibosi

uncle al said:


> Thanks-- I'm almost exclusively using high impedance headphones with my MK IV SE, and using lower impedance headphones (Q701, PX100) with one of three SS amps. I get that the 6SN7s produce richer bass than the 6HM5s, but how are the mids and highs of the 6SN7s, say with HD650s, HD800 or DT880 / 990 cans?


 
  
 there are many, many different 6SN7's. Some, like the RCA and Ken-Rad are known for their bass. Others, like the Sylvania are known for their highs. So it will be necessary to roll through a few of these to find the right balance for your ears and gear.


----------



## Rossliew

uncle al said:


> "Rossliew", Appreciated your much earlier WOW! post about near holographic audio from combination of 12AU7 / 6N23P combo with your LD MK III. I'm transitioning through several combinations including 6HM5 / 6H30Pi and possibility 6SN7s. Can you compare 12AU7 / 6N23P combo to 6SN7s in audio quality / soundstage?


 
 Hmm..am not that good with impressions but I will try my best.
  
 With some Tung Sol mouse ear 6SN7s and the 12AU7, i found the sound to be slightly congested with a narrower/compressed soundstage. Somehow, the 12AU7 and 6N23Ps gave a very good synergy that the sound signature "clicked" immediately for me. I was not left wanting and it could be so-called end-game combo.  Having said that, it all depends on the type of music you listen to and the entire chain feeding music to the amp. Hope it helps somewhat..


----------



## Oskari

bbmiller said:


> Are there any databases which lets you search for tubes by pin arrangement? Do pin arrangements of vacuum tubes have names that can be search for in any way? On the Internet? On a page itself if you search for the recognizable pin arrangement name, say in certain very good datasheets?


 
  
 There are the EIA base codes like 7BD for the 6AK5. See
  

http://www.nj7p.org/Tube/SQL/Tube_query.php?Type=6ak5
  
 If you click the "same base" button, you'll get a list of all the 7BD-based types in the database.
  
 TDSL PE lets you search in multiple ways, but this one you need to install on your computer and I'm not sure whether it runs on current Windows systems.
  

http://www.duncanamps.com/tdslpe/


----------



## sgbwill2

gibosi said:


> These tubes are similar to the 12AU7 in that they can be configured to operate in either a 6.3 volt or 12.6 volt circuit. In 12.6 volt circuits, they draw 0.45A and in 6.3 volt circuits, they draw 0.9A. As the LD employs a 6.3 circuit, these tubes will draw 0.9A. You will need an adapter configured to use them in 6.3 volt circuits:
> 
> http://www.ebay.com/itm/1x-5687-to-6N6-6N1-6N2-6N6-6N11-ECC88-E88CC-Vacuum-tube-adapter-socket-converter-/321472393335?


 
 Thanks for clearing that up. have you tried ECC40's yourself with the LD? and what would you expect to sound better ECC40's or 7044's?


----------



## i luvmusic 2

WOW! $20 for a Speedball upgrade for the BH CRACK..........


----------



## gibosi

sgbwill2 said:


> Thanks for clearing that up. have you tried ECC40's yourself with the LD? and what would you expect to sound better ECC40's or 7044's?


 
  
 I have run both these tubes as drivers, not powers. The ECC40 was manufactured only in Europe, Philips and Tungsram. Further, the ECC40 was manufactured in a number of different Philips factories. I have tubes from Eindhoven, Sittard, Suresnes, Chartres and Hamburg. I like all of the late 1940s early 1950's tubes, especially those from Eindhoven. I don't much care for those made after 1960.
  
 The 7044 was manufactured only the US. I have GE, RCA, Sylvania and Raytheon, However, I have not had a chance to listen to them, so I can't really say how much I like them..... Too many tubes... not enough time.... lol


----------



## MIKELAP

His there a wiring schematics for the C3GS tube adapter . Thanks.


----------



## gibosi

mikelap said:


> His there a wiring schematics for the C3GS tubes


 
  
 This old posting might help:
  
 http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/5010#post_10269194


----------



## MIKELAP

Would anybody have a ceramic loctal socket on hand would like to know what size is this diameter . Thanks


----------



## gibosi

mikelap said:


> Would anybody have a ceramic loctal socket on hand would like to know what size is this diameter . Thanks


 
  
 It looks to me like 2.5MM


----------



## MIKELAP

gibosi said:


> It looks to me like 2.5MM


 
  


gibosi said:


> It looks to me like 2.5MM


 
 Ok 25 m.m. thats a little less than 1 inch but looks like 25.5 m.m. is that possible or camera angle Thanks .


----------



## hypnos1

mikelap said:


> Would anybody have a ceramic loctal socket on hand would like to know what size is this diameter . Thanks


 
  
 Gibosi is right, M...but...2.5 CM (25MM).


----------



## Audiofanboy

Just read the last 30 some pages out of curiosity; nice work people! I can't believe how many tube possibilities we now have for our LDs! I also can't believe my name is still being mentioned after such a long absence, thanks for not forgetting about me and those first monstrous experiments with hanging double triodes...
  
 Like Mikelap said a few pages back, I am in Japan and had been virtually "gear-less" for many months, hence my disappearance. Now that my lifestyle here is getting more stable, I'm getting back in the hobby, piece of equipment by piece of equipment! Most of my gear is still in Europe--and 220V anyway--so I have to start from scratch here. I have the speakers, DAC preamp/headamp, and power amp, but I'm still missing the headphones--anybody say HE-560?--and tube headamp, but I'm getting drawn back pretty quickly and should be using my next paycheck or two to get some cool toys! My wallet is weeping already haha...
  
 Anyway, just a heads-up to say I'm still alive and intend to get back in the game at some point! In the meantime, happy rolling!


----------



## mordy

Hi AFB,
  
 Good to hear from you again, and good luck on getting your new stuff!


----------



## gibosi

AFB!  今日は! Great to hear from you!
  
 And I am very envious... One of my dreams is to be able to live in Japan for a year or two, but I just don't see it happening at this time.
  
 And of course, I am wondering which tube headamp you are planning to get??
  
 Cheers


----------



## gibosi

mikelap said:


> Ok 25 m.m. thats a little less than 1 inch but looks like 25.5 m.m. is that possible or camera angle Thanks .


 
  
 OK... tried this again... It looks to be a tad more than 26mm? But I wonder if these are perfectly round?


----------



## Acapella11

Good to hear back from you AFB, I am sure you will find some nice upgrades


----------



## MIKELAP

gibosi said:


> OK... tried this again... It looks to be a tad more than 26mm? But I wonder if these are perfectly round?


 
 I asked a guy on ebay that sells those sockets he's saying 26.5 m.m. also so thats 1.035 approx , so  i guess its around there  and thats good my copper fitting is that size so its looking good . Once finished adapters hopefully will be about 11/2 inch tall or less will have to cut that's for shure.


----------



## bbmiller

I seek understanding as to why in this article the person writing it has called the 6H30 - 6N30 tubes the Supertubes! I do not know if I be so enthused that I should try to purchase one of these tubes as power tubes. (For one thing I do not know if any of them they should be significantly different sounding from 6h30pi which already comes with my little dot IV MK SE.) But if you believe the article these parameter values are very significant to its sonic excellence, so let me quote what the writer of the article claims are parameters of sonic excellences and ask you why these are parameters of sonic excellence?


> 6H30 has Amplification factor 15, Plate resistance 200 Ω, Transconductance 72 mA/V and it is very linear


 
  
 So can you explain to me here why these are parameters of sonic excellences or alternatively suggest readings, searches, or links which might yield the answer to me? I think I have the linearity one licked, but if you could help me with those of the parameters I would be greatly appreciative.


----------



## TrollDragon

Looking good MIKELAP!

You should have a look on eBay for some 1" to 5/8" reducers, less cutting involved.

They would look nice in aluminum or stainless steel as well.


----------



## MIKELAP

trolldragon said:


> Looking good MIKELAP!
> 
> You should have a look on eBay for some 1" to 5/8" reducers, less cutting involved.
> 
> They would look nice in aluminum or stainless steel as well.


 
 i had a look didnt see the size i needed,  get me a lathe man youll have them in whatever type of metal  you want lol .and dont show me pictures of those mini lathes lol .


----------



## mordy

Hi bb,
  
 Heard about Superman? Supertubes? The humble people on this forum have listened to and compared the supertubes to other power tubes of the same family, and different ones as well. The 6H30-DR so called supertubes are only incrementally better than the much less expensive 6N6P-IR tubes (mainly slightly better bass). The conclusion is that in relation to the Little Dot amp, the supertubes are marketing hype.
  
 For very little money, the 6SN7 garden variety octal tubes used as power tubes are much better (only need adapters to work in the LD), and the 6AS7/6080 are even better but the latter need adapters + an external power supply.
  
 Man, this is crazy - just checked EBay  for supertubes. They go for $250-350 each! Three years ago u could pick up a pair for $100. And there are only half a dozen offerings...6N6P-IR tubes go for $34-41/pair today.
  
 There are only some 2500 listings for 6SN7 tubes, and about 500 for pairs. What do I mean with garden variety? Right now, today, u can pick up rebranded Sylvania tubes for $15-18/pair including shipping Buy it now. IMHO a pair of these will sound better than a pair of supertubes for $700. However, they don't come with bragging rights - Zenith? Capeheart? Silvertone? Radioshack?!
  
 Let your ears judge....


----------



## JazzVinyl

I have broken open the non-functional C3g->6AK5 socket adapter.  I was able to get the glass pin side off okay, but not able to get the Loctal socket out, without
 damaging it. So, I broke off the Loctal side and now have a good pin side and have ordered a new Loctal socket for the top of the adapter.
 In checking the WORKING adapter, I have found the C3g to Loctal continuity as thus:
  
 C3G         6AK5
 1---------->3
 2---------->2 and 7
 3---------->1
 4---------->Not connected to any 6AK5 pins
 5---------->6
 6---------->5
 7---------->2 and 7
 8---------->4
  
 Socket 4 is not used on the C3g side.
  
 This is how I plan to solder the pins back up to the new Loctal socket.
 The non working adapter differed from above, and surely was the cause of the malfunction.
 Also note that the pin side has but 6 wires showing, there must be a jumper between pins 2 and 7 that I cannot see.
 Will post some photos, later tonight.


----------



## i luvmusic 2

mikelap said:


> gibosi said:
> 
> 
> > OK... tried this again... It looks to be a tad more than 26mm? But I wonder if these are perfectly round?
> ...


 
 This was done a month ago (6SN7 to 12AU7).


----------



## TrollDragon

jazzvinyl said:


> I have broken open the non-functional C3g->6AK5 socket adapter.  I was able to get the glass pin side off okay, but not able to get the Loctal socket out, without
> damaging it. So, I broke off the Loctal side and now have a good pin side and have ordered a new Loctal socket for the top of the adapter.
> In checking the WORKING adapter, I have found the C3g to Loctal continuity as thus:
> 
> ...


 
 There is something off in your wiring, Pin 3 on the C3G is the anode of the tube and pin 1 on the 6AK5 is the first grid....
  
 This was posted a while back on C3G to 6AK5 wiring.
  

C3g 6AK5   1->32->73->54->65->26->17->78->  
 [size=inherit]4[/size]
  

  
 You might want to check it again, just sayin...


----------



## TrollDragon

i luvmusic 2 said:


> This was done a month ago (6SN7 to 12AU7).
> 
> 
> 
> Spoiler: Warning: Spoiler!


 
 With a fully wide open chassis like you have, why would you not just mount an octal socket underneath?


----------



## JazzVinyl

trolldragon said:


> There is something off in your wiring, Pin 3 on the C3G is the anode of the tube and pin 1 on the 6AK5 is the first grid....
> 
> This was posted a while back on C3G to 6AK5 wiring.
> 
> ...


 

 Yes, I did check mine again that original post and I know my finding does differ, but it does work.
  
 Working correctly?  Maybe or maybe not...


----------



## i luvmusic 2

trolldragon said:


> i luvmusic 2 said:
> 
> 
> > This was done a month ago (6SN7 to 12AU7).
> ...


 
 It only look wide open on top but underneath  a lot of things need to be moved before you can install a OCTAL socket specially with the Speedball everything need to be move back plus i still used 12AU7 sometimes.


----------



## MIKELAP

i luvmusic 2 said:


> This was done a month ago (6SN7 to 12AU7).


 
 So they make a fitting 1 inch to 5/8 inch .


----------



## gibosi

jazzvinyl said:


> Yes, I did check mine again that original post and I know my finding does differ, but it does work.
> 
> Working correctly?  Maybe or maybe not...


 
  
 This extra detail might help you to determine what is going on inside your adapter.
  

C3g 6AK5   1 heater->3 heater2 grid 3->7 grid 33 plate->5 plate4 grid 2->6 grid 25 cathode->2 cathode6 grid 1->1 grid 17 cathode->7 grid 38 heater->  
 4 heater
  

​


----------



## i luvmusic 2

mikelap said:


> i luvmusic 2 said:
> 
> 
> > This was done a month ago (6SN7 to 12AU7).
> ...


 
 The 1'' to 1/2'' will give you 1-1/8 to 5/8.But if you go to the hardware store asked them for 1 to 1/2 they don't include the wall thickness of the pipes. 
  
 NOTE:
 Copper Pipes comes in different types so the wall thickness and hardness varies. 
 Most common types are Type M and Type L,Type L is thicker than Type M.


----------



## JazzVinyl

gibosi said:


> This extra detail might help you to determine what is going on inside your adapter.
> 
> 
> C3g 6AK5   1 heater->3 heater2 grid 3->7 grid 33 plate->5 plate4 grid 2->6 grid 25 cathode->2 cathode6 grid 1->1 grid 17 cathode->7 grid 38 heater->
> ...


 
  
 Thanks for this gibosi...
  
 But now I am really confused!
  
 I am certain that what I posted is how the happydiy998 adapter that works...is wired.
  
 According to this, even the working adapter is wired wrong!?
  
 Would it make sound wired wrong?
  
 I had noted that even with the "working adapter" I did not hear a "glorious rapture"...as expected...
  
 Any ideas?
  
 .


----------



## MIKELAP

i luvmusic 2 said:


> The 1'' to 1/2'' will give you 1-1/8 to 5/8.But if you go to the hardware store asked them for 1 to 1/2 they don't include the wall thickness of the pipes.
> 
> NOTE:
> Copper Pipes comes in different types so the wall thickness and hardness varies.
> Most common types are Type M and Type L,Type L is thicker than Type M.


 
 When i say 1¨and 5/8¨i talking bore size .


----------



## i luvmusic 2

mikelap said:


> i luvmusic 2 said:
> 
> 
> > The 1'' to 1/2'' will give you 1-1/8 to 5/8.But if you go to the hardware store asked them for 1 to 1/2 they don't include the wall thickness of the pipes.
> ...


 
 Are you looking to mount a 7 pin socket?
 5/8 is the bore size for 1/2" fittings.
 1-1/8 is the bore size for 1" fittings.


----------



## MIKELAP

i luvmusic 2 said:


> Are you looking to mount a 7 pin socket?
> 5/8 is the bore size for 1/2" fittings.


 
 need 5/8 bore for 7 pin socket


----------



## i luvmusic 2

mikelap said:


> i luvmusic 2 said:
> 
> 
> > Are you looking to mount a 7 pin socket?
> ...


 
 Then you need a 1/2 fittings that gives you your 5/8 bore.
 For 9 pin socket you need 3/4 fittings this is what i used.


----------



## gibosi

jazzvinyl said:


> What it make sound wired wrong?
> 
> I had noted that even with the "working adapter" I did not hear a "glorious rapture"...as expected...


 
  
 Tubes can be wired up in all different kinds of ways, and they will often still work, but perhaps not sound so good.... lol 
  
 Taking a look at what you have found....
  
 C3G         6AK5
 1 heater ---------->3 heater
 2 grid 3 ---------->2 and 7 cathode and grid 3
 3 plate ---------->1 grid 1
 4 grid 2---------->Not connected to any 6AK5 pins
 5 cathode ---------->6 grid 2
 6 grid 1 ---------->5 plate
 7 cathode ---------->2 and 7 cathode and grid 3
 8 heater ---------->4 heater 
  
 Obviously, you should switch things around so that grid 1 and the plate are connected properly. And then, connect grid 2 in each tube. And since the C3g pins 5 and 7 are tied together inside the tube, you can leave 5 not connected. Also, it is useful to know that 6AK5 pins 2 and 7 are tied together inside the tube.
  
 You have to remember that both the C3g and the 6AK5 are pentodes. And therefore, it is necessary to convert them into triodes. This is done by tying the extra grids, grid 2 and grid 3, to either the plate or the cathode.
  
 In the EF95 setting, your amp expects to see a 6AK5 with the cathode tied to grid 3. And on the circuit board, the amp will tie grid 2 (pin 6) to the plate (pin 5). And thus, you have a triode-strapped 6AK5.
  
 So first, we need to strap the cathode and grid 3 in the C3g together. And the adapter you have does this by tying them to the strapped cathode and grid 3 in the 6AK5. Second, grid 2 of the C3g must be aligned with grid 2 of the 6AK5 so that the LD can strap grid 2 to the plate. Once that is done, it is a simple matter to make sure the heaters, cathode, grid 1 and the plate are lined up correctly.
  
 So this should work:
  
 C3G         6AK5
 1 heater ---------->3 heater
 2 grid 3 ---------->2 and 7 cathode and grid 3
 3 plate ---------->5 plate
 4 grid 2---------->6 grid 2
 5 cathode ----------> not connected
 6 grid 1 ---------->1 grid 1
 7 cathode ---------->2 and 7 cathode and grid 3
 8 heater ---------->4 heater


----------



## vic2vic

gibosi said:


> Tubes can be wired up in all different kinds of ways, and they will often still work, but perhaps not sound so good.... lol
> 
> Taking a look at what you have found....
> 
> ...


 
  
 I just noticed a thing, driven by the comment of the "unconnected" pin: if you consider the C3G pin connections provided by JazzVinyl in reverse order (8-->1 instead of 1-->8), you actually got the same connections proposed by Gibosi (except for the heaters and 2/7, which are shortened anyway. Would it work anyway?).
 Maybe it's only a problem of reading the pins in the wrong sequence. It happened to me a couple of times when preparing other adapters


----------



## TrollDragon

vic2vic said:


> I just noticed a thing, driven by the comment of the "unconnected" pin: if you consider the C3G pin connections provided by JazzVinyl in reverse order (8-->1 instead of 1-->8), you actually got the same connections proposed by Gibosi (except for the heaters and 2/7, which are shortened anyway. Would it work anyway?).
> Maybe it's only a problem of reading the pins in the wrong sequence. It happened to me a couple of times when preparing other adapters


 
 Bingo, that is exactly what has happened, reverse pinout.
 Good Catch!


----------



## JazzVinyl

vic2vic said:


> I just noticed a thing, driven by the comment of the "unconnected" pin: if you consider the C3G pin connections provided by JazzVinyl in reverse order (8-->1 instead of 1-->8), you actually got the same connections proposed by Gibosi (except for the heaters and 2/7, which are shortened anyway. Would it work anyway?).
> Maybe it's only a problem of reading the pins in the wrong sequence. It happened to me a couple of times when preparing other adapters


 

 Wow...you may be on to something, vic2vic!
  
 I counted them in this fashion:


----------



## bbmiller

> bbmiller said:
> 
> 
> > I seek understanding as to why in this article the person writing it has called the 6H30 - 6N30 tubes the Supertubes! I do not know if I be so enthused that I should try to purchase one of these tubes as power tubes. (For one thing I do not know if any of them they should be significantly different sounding from 6h30pi which already comes with my little dot IV MK SE.) But if you believe the article these parameter values are very significant to its sonic excellence, so let me quote what the writer of the article claims are parameters of sonic excellences and ask you why these are parameters of sonic excellence?
> ...


 


> Hi bb,
> 
> Heard about Superman? Supertubes? The humble people on this forum have listened to and compared the supertubes to other power tubes of the same family, and different ones as well. The 6H30-DR so called supertubes are only incrementally better than the much less expensive 6N6P-IR tubes (mainly slightly better bass). The conclusion is that in relation to the Little Dot amp, the supertubes are marketing hype.
> 
> ...


 
 Quote:


gibosi said:


> I suggest you try a few different 6SN7's, gray-glass RCA, black-glass National Union, chrome-top Sylvania and "mouse ears" Tung Sol, to see what you like. I encourage you to seek out the earliest tubes you can afford, but as Mordy will attest, there are some very good-sounding 6SN7GTB's to be had for not much money.
> 
> Further, there are a number of very informative threads devoted to this wonderful tube:
> 
> ...


 
 "$15-18/pair including shipping Buy it now. IMHO a pair of these will sound better than a pair of supertubes for $700. However, they don't" come with bragging rights - Zenith? Capeheart? Silvertone? Radioshack?!"

 OK requoting Mordy  from my quote middle above $15-$18 for a pair sounds awful good but as explained on this thread and with all those links above from gibosi 6SN7 is part of the 6SN7 enormous universe. So were I to jump on those other threads suggested by gibosi we you can learn more a bout  6SN7 enormous universe, to push finding the best possible 6SN7 or at least give it my best try, would I be looking for one that looks like the parameters in the quote of myself above if possible?

 Also forgive me very much for forgetting, but now that I am getting into to rolling in a more serious way what exactly is the adapter required in the power tube socket to use the 6SN7 octal's. Looking at the data sheet from the stock power tube 6h30pi it appears we are going from a mini glass envelope nine pin with pin nine grounded to an larger octal?


----------



## gibosi

jazzvinyl said:


> Wow...you may be on to something, vic2vic!
> 
> I counted them in this fashion:


 
  
 This is the view when you look down on the tube while holding it upside down. When working on this adapters, you are essentially looking at the bottom of the C3g, counting pins from left to right, clockwise, and looking at the top of the 6AK5, counting pins right to left, counterclockwise. Keeping these two orientations straight while working on an adapter can be be quite a challenge.
  
 Good luck!


----------



## gibosi

bbmiller said:


> OK requoting Mordy  from my quote middle above $15-$18 for a pair sounds awful good but as explained on this thread and with all those links above from gibosi 6SN7 is part of the 6SN7 enormous universe. So were I to jump on those other threads suggested by gibosi we you can learn more a bout  6SN7 enormous universe, to push finding* the best possible 6SN7* or at least give it my best try, would I be looking for one that looks like the parameters in the quote of myself above if possible?
> 
> Also forgive me very much for forgetting, but now that I am getting into to rolling in a more serious way what exactly is the adapter required in the power tube socket to use the 6SN7 octal's. Looking at the data sheet from the stock power tube 6h30pi it appears we are going from a mini glass envelope nine pin with pin nine grounded to an larger octal?


 
  
 We have to remember... Everyone's ears are different. Even with the same tubes, same headphones and same electronics, one person will love them and another will find them so-so. As Mordy reminded us some time ago, tubes are like ice cream. Everyone has a different favorite flavor. And in order to discover your favorite, you might have to try every flavor in the ice cream shop! lol. So I really think you will have to try at least a few to determine your favorite flavor. And when you have found your favorite, it very likely won't be everyone's favorite, especially when you consider that not only do we all have different ears, but also different headphones and different electronics.
  
 The adapter you need converts a standard 8-pin octal 6SN7 to a 9-pin 6DJ8 / 6N6 / 6N11 / 6CG7 / 6N30P
  
 http://www.ebay.com/itm/1pc-6SN7-6H8C-6N8P-CV1988-B65-VT231-TO-ECC88-6922-6DJ8-6N6-6N11-tube-adapter-/201083508552?


----------



## JazzVinyl

gibosi said:


> This is the view when you look down on the tube while holding it upside down. When working on this adapters, you are essentially looking at the bottom of the C3g, counting pins from left to right, clockwise, and looking at the top of the 6AK5, counting pins right to left, counterclockwise. Keeping these two orientations straight while working on an adapter can be be quite a challenge.
> 
> Good luck!




Indeed, I can see how the mistake could be made! 

You have been helpful, gibosi, and i very much appreciate it!!

.


----------



## mordy

Hi bb and G,
  
 Personally, I don't think that you can find "the best tube" either by price and measured parameters. Let's switch to ice cream - more neutral topic. Most people like ice cream, and I assume that you do as well. How do you know which brand and flavor ice cream you like?
  
 Because you tasted it. It's not how much it cost, or what the ingredients are that made you decide that you liked it. You tasted it and said to yourself: I really like this one.
  
 And no matter how somebody would explain to you how good this or that one tastes, there is no way of really knowing how it tastes until you take some into your mouth. You get it...
  
 It is the same with tubes, but more complicated since they need to be burnt in and be paired with synergistic equipment. (My currently best set of power tubes sounded so bad when they were new that I was ready to write them off and throw them on the dust pile.)
  
 What I did was to just look for varied bargain lots and get a bunch of tubes (six, eight, ten etc) and listen. After a while you learn to hear the differences and you learn how to describe them. To my surprise I found other people on this forum that heard the same things I heard so I knew that I wasn't just imagining what I heard. And we were able to agree on groups of top tier tubes and on tube families that were much better than others.
  
 If you get a Sylvania made tube (as an example) it doesn't matter if it was rebranded and sold by Radioshack or Sears. It is still a Sylvania tube with the EIA (Electronics Industry Association) number 312 on it. IMHO you do not need to spend big bucks to get excellent sound.
  
 The best tube is the one YOU like the best, the one that sounds the best to YOU. Not what the marketing guys tell you is the best. Not the most expensive one. Not the rarest one, and certainly not the oldest one; not the most exotic one, or the one with the most glow or the biggest size etc etc. And everybody knows that British/Dutch/Russian/Japanese/US tubes are the best.....(Personally, I have had the best luck in finding favorite tubes among those that were US made)
  
 There is plenty advice on this blog. The best way to find out what you like is to follow some of the recommendations, get the tubes, and listen.
  
 Happy tube rolling!


----------



## gibosi

bbmiller said:


> I seek understanding as to why in this article the person writing it has called the 6H30 - 6N30 tubes the Supertubes! I do not know if I be so enthused that I should try to purchase one of these tubes as power tubes. (For one thing I do not know if any of them they should be significantly different sounding from 6h30pi which already comes with my little dot IV MK SE.) But if you believe the article these parameter values are very significant to its sonic excellence, so let me quote what the writer of the article claims are parameters of sonic excellences and ask you why these are parameters of sonic excellence?
> 
> So can you explain to me here why these are parameters of sonic excellences or alternatively suggest readings, searches, or links which might yield the answer to me? I think I have the linearity one licked, but if you could help me with those of the parameters I would be greatly appreciative.


 
  
 There are those who believe that the best tubes are those with the "best" measurements. And there are those who believe that measurements are useless. I find that I am in the middle. Measurements are useful, but they are not in and of themselves enough. I wholeheartedly agree with this quote:
  
 "If it measures good and sounds bad, it is bad. If it sounds good and measures bad, you've measured the wrong thing." - Daniel R. von Recklinghausen
  
 So my advice is to believe your ears. In the end, your ears are the best test and measurement instruments available to you.


----------



## gibosi

Has anyone with an external heater PS tried 6BL7's as output tubes?
  
 Judging from this review, they just might be pretty good:
  
 http://www.tweak-fi.com/apps/blog/show/42754587-building-a-reference-system-part-2-glenn-s-headphone-amplifier


----------



## mordy

Hi G,
  
 Don't remember if I tried the the 6BL7 as a power tube, but I tried it as a driver tube. It is an 1 1/2A  tube. However, IMHO a tube that performs well as a driver tube (and has enough power to work as a power tube) will perform well as a power tube.
  
 The 6BX7 is similar to the 6BL7 and I found that I liked the sound of the 6BX7 better. The 6BL7 has an amplification factor of 15 and the 6BX7 an amplification factor of 10; otherwise they seem very similar. In the Glenn amp you are dealing with 6 tubes instead of two - don't know how this changes the dynamics. Maybe we should ask the the user if he tried the 6BX7 tubes as well?
  
 At the present time I am so happy with my set up that I really don't want to change - 2 Sylvania 6080WA and a GE 5687 as driver.
  
 Saw several sellers of the GE 5687 state that it was made by Tung Sol (even though the pictures show the EIA # of 188 which is the GE factory code). Don't know the basis how they can state this....


----------



## hypnos1

jazzvinyl said:


> Wow...you may be on to something, vic2vic!
> 
> I counted them in this fashion:


 
  
 Hi JV...and everyone else assisting here. Sorry I myself have been a bit lax coming in, but things have been very hectic recently...my upcoming (soon!) pictorial would have clarified things somewhat, but gibosi et al have hopefully answered all your queries and provided the correct pin order/placement.
 Now that you are reading pin order correctly - both from the bottom of the upside down tube, and as it appears looking _down_ on the target socket (reversed of course but yes, can sometimes get confusing and catch you out!) - hopefully all should be well. I personally have found it helpful - nay _essential!_ - to mark the bottom target socket/pin aligner-holder of the adapter with the reverse numbering, as below...
  

  
 ps...The end result is the same, but I personally connect pin 2 (grid 3) to pin 7 (cathode) at the C3g end, and pin 5 (cathode) of C3g to pin 2 of 6AK5...
  
 Hope all goes well for you now...


----------



## hypnos1

mikelap said:


> I asked a guy on ebay that sells those sockets he's saying 26.5 m.m. also so thats 1.035 approx , so  i guess its around there  and thats good my copper fitting is that size so its looking good . Once finished adapters hopefully will be about 11/2 inch tall or less will have to cut that's for shure.


 
  
 Hi again M.
  
 You're probably sorted by now, but it looks like different makes have different specs...mine (below) are indeed the 25mm mentioned...
  

  
 ps... Hope you're going to give folks a full pictorial on how to make 'em...


----------



## MIKELAP

hypnos1 said:


> Hi again M.
> 
> You're probably sorted by now, but it looks like different makes have different specs...mine (below) are indeed the 25mm mentioned...
> 
> ...


 
 Will do ,i ordered my parts and will try and find a 1 piece housing if not will modify parts in picture above so that in the end adapter is shorter


----------



## hypnos1

audiofanboy said:


> Just read the last 30 some pages out of curiosity; nice work people! I can't believe how many tube possibilities we now have for our LDs! I also can't believe my name is still being mentioned after such a long absence, thanks for not forgetting about me and those first monstrous experiments with hanging double triodes...
> 
> Like Mikelap said a few pages back, I am in Japan and had been virtually "gear-less" for many months, hence my disappearance. Now that my lifestyle here is getting more stable, I'm getting back in the hobby, piece of equipment by piece of equipment! Most of my gear is still in Europe--and 220V anyway--so I have to start from scratch here. I have the speakers, DAC preamp/headamp, and power amp, but I'm still missing the headphones--anybody say HE-560?--and tube headamp, but I'm getting drawn back pretty quickly and should be using my next paycheck or two to get some cool toys! My wallet is weeping already haha...
> 
> Anyway, just a heads-up to say I'm still alive and intend to get back in the game at some point! In the meantime, happy rolling!


 
  
 Hi AFB (if somewhat belated!)...great to hear from you, and hope life is good for you in that fascinating country (channel NHK is one of my favourites on SKY TV!).
  
 As you may have gathered already, the C3g driver has proved to be a real winner, for myself and a good few others now. If you hadn't tossed that into the mix of alternatives - some good while ago now! - I wouldn't have been tempted to adapt it for the LD (even though I previously liked the fact that Yamamoto uses the 20V C3m version in one of his fabulous amps). Its synergy with the 6AS7G/6080 (my rather expensive GEC CV2523/6AS7G especially!) is quite extraordinary, lol!! 
	

	
	
		
		

		
		
	


	



  
 So, mon ami, we must all say to you...merci bien; vielen dank; grazie mille; muchas gracias!...don't know any Japanese, I'm afraid.
  
 Good luck with your return to the wallet-emptier...it will be interesting to hear what gear you end up with!!


----------



## natra084

I


----------



## bbmiller

hypnos1 said:


> Well guys, looks like you just might not be free of me after all lol!
> 
> Have decided to let my local repair man, who does a lot of work on old "valve" radios, have a look at my LD. So hopefully we will get some idea of just what happened and what needs to be done...as per lemonjelly's postings. My feller mentioned anode resistors and possible caps/coupling caps as well as cathode resistors...it looks like he's gonna give it a good going over at least. And if the bill isn't _too_ steep, I just might have my beloved amp back in my arms!
> 
> ...


 
 Sorry if I missed it. This enormous thread sometimes can get away from you. But can hypnos1 report or can I be pointed to the report if I missed it of just what hypnos1 repair man reported went wrong with hypnolittle1's little dot amplifier ?

 Can I also get a rehash of what possibly caused the need for a repair in the first place of his little dot amp?


----------



## TrollDragon

hypnos1 said:


> Right guys, here goes...
> 
> First, the BAD news...I'm a first class idiot (which some may have gathered by now lol!).
> 
> ...


 
  
  


bbmiller said:


> Sorry if I missed it. This enormous thread sometimes can get away from you. But can hypnos1 report or can I be pointed to the report if I missed it of just what hypnos1 repair man reported went wrong with hypnolittle1's little dot amplifier ?
> 
> Can I also get a rehash of what possibly caused the need for a repair in the first place of his little dot amp?


 
  
 His headphone wires had broken and there was nothing wrong with the Little Dot.


----------



## bbmiller

trolldragon said:


> hypnos1 said:
> 
> 
> > Right guys, here goes...
> ...


 


> But even if all is well, from mordy's near-miss, it would appear mods ARE needed so I shall go ahead and see what my local valve/tube man suggests.
> 
> Sorry to have been premature, but at least it has been a wake-up call to stop taking such a big risk and try to get it sorted...something I'm sure mordy now agrees with, lol!


 
 So did local valve/tube man suggests any mods to make the little dot amp more rope plus or less likely to burn out? Is there anything that you all would suggest?


----------



## hypnos1

bbmiller said:


> So did local valve/tube man suggests any mods to make the little dot amp more rope plus or less likely to burn out? Is there anything that you all would suggest?


 
  
 Hi bbm.
  
 It would appear the cathode bias resistor needs to be uprated, but then its accompanying capacitor may also need changing - according to lemonjelly. If you punch up his postings a while back, you will find more info on this...but later he seemed to think the plate draw problem, and hence extra load on the transformer, (as a consequence of uprating said resistor) might not be so serious after all. So all is still not too clear, I'm afraid. And as I didn't need to visit my local man after all - especially given the upcoming Feliks-Audio unit - he hasn't been able to investigate/modify the LD itself.
  
 All I can say is that my MKIV SE has not yet shown any ill-effects from the punishment, and the resistor concerned never reached an alarmingly high temp. when I monitored it for some hours' continuous use...but this apparently doesn't necessarily mean all is well!!
  
 So in the end it comes down to personal choice as to what path to take, I'm afraid...I personally think the best thing is to just keep going until the amp says 'enough is enough' (making sure you don't jump to conclusions as I did, and check EVERYTHING else first before blaming the resistor!) and simply confirm if the resistor(s) needs replacing and if so, use slightly higher rated ones...we are always having to take _slight_ risks when veering a good way off the stock configuration, lol!


----------



## Acapella11

The pin numbering inversion happened quite a few times back when we started with non-EF91/92/95 driver tubes.
  
 Received now AK5-vector socket extender, C3G-AK5 adapter and a while ago already the Siemens C3GS tubes (thanks superdux).
  
 Just listening to it and it sounds very promising with the HD800s. Larger stage than with the 6HM5 for sure and the first impression is quite nice. Will come back once they are further burnt in. Took a shot from the big tube adapter assemblies put together. Not the most beautiful setup but sounds good as far as I can tell. 
  
  

  
 For reviews of 6N6P standard compatible driver tubes, look at this post #3007. It includes impressions from Mordy, Audiofanboy and myself.


----------



## MIKELAP

acapella11 said:


> The pin numbering inversion happened quite a few times back when we started with non-EF91/92/95 driver tubes.
> 
> Received now AK5-vector socket extender, C3G-AK5 adapter and a while ago already the Siemens C3GS tubes (thanks superdux).
> 
> ...


 
 Thats good to know sounds promising .Was looking for that post just the other day Thanks alot .


----------



## mordy

Hi bbm.
  
 I have been using the LD MKIII with 2.5A power tubes with an external power supply for many many hours, and IMHO these tubes are perfectly safe to use with the LD amp with the provision that the amp is also cooled by an external fan.
  
 Previous posts show how to assemble an external power supply and how to arrange simple cooling with inexpensive computer fans.


----------



## mordy

Hi A11,
  
 I notice that you use the OEM family 6N6P power tubes. If you would switch to plug and play 6SN7 type tubes (only requiring adapters) the sound would improve further, especially the bass.


----------



## MIKELAP

mordy said:


> Hi A11,
> 
> I notice that you use the OEM family 6N6P power tubes. If you would switch to plug and play 6SN7 type tubes (only requiring adapters) the sound would improve further, especially the bass.


 
 Expecting those 6sn7 adapters from China hopefully this year lol  .


----------



## hypnos1

acapella11 said:


> The pin numbering inversion happened quite a few times back when we started with non-EF91/92/95 driver tubes.
> 
> Received now AK5-vector socket extender, C3G-AK5 adapter and a while ago already the Siemens C3GS tubes (thanks superdux).
> 
> ...


 
  
 Hi A11.
  
 Glad you are giving the C3gSs a try...they keep improving up to 50 hrs or even more. And as mordy says, the 6SN7 as power will do them a good bit more justice. But the real leap then comes when partnered with the 6AS7G/6080. I truly hope you give this option a try at some stage...the mods are not _too_ difficult 
	

	
	
		
		

		
			





.
  
 I am beginning to suspect that those C3g adapters may not be helping the tube to achieve its full potential...when they work at all, lol!! But I do hope you have no trouble with yours....


----------



## Acapella11

mordy said:


> Hi A11,
> 
> I notice that you use the OEM family 6N6P power tubes. If you would switch to plug and play 6SN7 type tubes (only requiring adapters) the sound would improve further, especially the bass.


 

 Hi Mordy,
  
 They are 6H30P-DRs, but yeah, may as well try some 6SN7 plus vector extender and adapter and sell these. 
  
 Quote:


hypnos1 said:


> Hi A11.
> 
> Glad you are giving the C3gSs a try...they keep improving up to 50 hrs or even more. And as mordy says, the 6SN7 as power will do them a good bit more justice. But the real leap then comes when partnered with the 6AS7G/6080. I truly hope you give this option a try at some stage...the mods are not _too_ difficult
> 
> ...


 
  
 Hi Hypnos1,
  
 They are coming along very well. Looking forward to see how they burn in the next 50 hours. Doubt, I can restrain myself for long from looking into alternative power tubes.  
  
 Another upgrade I am seriously considering is: http://www.powerinspired.com/ag500-ac-regenerator-500w-p-1723.html I had the opportunity to use it for a few hours and the difference was quite impressive on my setup.


----------



## bbmiller

mordy said:


> Hi bbm.
> 
> I have been using the LD MKIII with 2.5A power tubes with an external power supply for many many hours, and IMHO these tubes are perfectly safe to use with the LD amp with the provision that the amp is also cooled by an external fan.
> 
> Previous posts show how to assemble an external power supply and how to arrange simple cooling with inexpensive computer fans.


 
  Were you to use a massive amount of aluminum fin heatsinks with a good enough thermal paste and fasten these heatsinks on three sides to the rear transformer could that in your opinion be a good alternative to fan cooling that would be totally passive?


----------



## Acapella11

Hi Hypnos1 and Gibosi,
  
 How great differences in SQ have you found between different C3GS tubes?


----------



## i luvmusic 2

If you want to go that route why not replaced the whole chassis and install a cooling fan in the back of the chassis.It's not just the Transformer heating up some internal components  heating up too.
  
 Sorry! for butting in.........


----------



## MIKELAP

Time to relax and enjoy a little tube glow.


----------



## gibosi

acapella11 said:


> How great differences in SQ have you found between different C3GS tubes?


 
  
 To the best of my knowledge, all C3g tubes were manufactured by Siemens, so there is nothing to be gained by rolling through the different "brands".
  
 Good news for your wallet!


----------



## Rossliew

mikelap said:


> Time to relax and enjoy a little tube glow.


 
  
 You managed to get a WA6, Mike?


----------



## gibosi

bbmiller said:


> Were you to use a massive amount of aluminum fin heatsinks with a good enough thermal paste and fasten these heatsinks on three sides to the rear transformer could that in your opinion be a good alternative to fan cooling that would be totally passive?


 
  
 I suggest that you search out and read lemonjelly's recent posts on this subject. The most vulnerable components appear to be a few resisters. Heatsinks and so forth likely wouldn't help. But replacing these resisters with higher rated ones is highly recommended.


----------



## TrollDragon

mikelap said:


> Time to relax and enjoy a little tube glow.
> 
> 
> Spoiler: Booh Yeah...


 
 Would that be a Sophia Princess 274B Mesh Plate???
  
*Very Nice! *


----------



## MIKELAP

trolldragon said:


> Would that be a Sophia Princess 274B Mesh Plate???
> 
> *Very Nice! *


 
 Oui mon ami !


----------



## mordy

Hi bbm,
  
 My LD MKIII sits on three 1" aluminum cones stuck to the bottom of the amp with bluetack (generic). I use two discarded 12V computer fans, 3" and 4" . These fans can be bought new for $ 4-5.
  
 The footers allow ample air circulation around the amp. The fans are mounted above the amp and are drawing air away from it.
  
 I don't see any reason to use massive heat sinks when there are much simpler solutions.


----------



## mordy

Hi,
  
 Here is a very informative link about the C3g tubes. It is interesting to note that these tubes when new sold for around $200 each. The very high specs were needed to lower noise and improve gain on telephone conversations over transatlantic cables.
  
 http://www.jacmusic.com/techcorner/ARTICLES/English-neu/Portraits/C3g/C3g-C3m-info.html


----------



## mordy

Hi G,
  
 According to the price list from JACMusic, there are C3g tubes with the names of Lorenz, Telefunken and Valvo as well, in addition to Siemens. Don't know if these were rebranded,
 Look at items # 92-102 on the price list.
  
 http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&ved=0CCAQFjAA&url=http%3A%2F%2Fwww.jacmusic.com%2Fhtml%2Forder%2Fjacmusic-pricelist.pdf&ei=qYBIVPjjCu_CsATz3oDQDw&usg=AFQjCNGPMXPhuUTZ5BtAwtX4T7A5I_DIAg&sig2=SXAYs79ijQNAlPBsbduVxA&bvm=bv.77880786,d.cWc
  
 There is also another type not mentioned before, the C3o. This is a C3m (20V tube)  manufactured for 6.3V usage.
  
 Here is a very informative page about the history and usage of the C3g tubes:
  
  
 http://www.jacmusic.com/techcorner/ARTICLES/English-neu/Portraits/C3g/C3g-C3m-info.html


----------



## gibosi

mordy said:


> According to the price list from JACMusic, there are C3g tubes with the names of Lorenz, Telefunken and Valvo as well, in addition to Siemens. Don't know if these were rebranded,
> 
> There is also another type not mentioned before, the C3o. This is a C3m (20V tube)  manufactured for 6.3V usage.


 
  
 I am reasonably sure that Lorenz, Valvo and Telefunken C3g were all manufactured by Siemens. I very much doubt that there was enough demand for this tube to justify the costs necessary for each of these manufacturers to produce their own version, but of course, I cannot be positive.... 
  
 While I was watching for a good price on a pair of C3g/s, I thought about getting a pair of C3o. However, the pin-out on these is different than the C3g. So while I could purchase adapters for the C3g (at that time), I would have had to cobble together a pair of suitable adapters, and very frankly, I really don't need anymore projects. lol.


----------



## mab1376

acapella11 said:


> Hi Hypnos1,
> 
> They are coming along very well. Looking forward to see how they burn in the next 50 hours. Doubt, I can restrain myself for long from looking into alternative power tubes.
> 
> Another upgrade I am seriously considering is: http://www.powerinspired.com/ag500-ac-regenerator-500w-p-1723.html I had the opportunity to use it for a few hours and the difference was quite impressive on my setup.


 
  
 I'm currently using 6SU7GTY (6SL7) as power tubes and they pair very well with my very sensitive Beyer T70. They also sound very nice with my HD650's.
  
 i haven't done very through A/B testing but i'm liking it subjectively. I would recommend someone else try the 6SL7 type with their phones report back.
  
 I wouldn't bother with orthos or other power hungry cans due to the lower spec of the 6SL7 vs 6SN7.


----------



## hypnos1

acapella11 said:


> Hi Hypnos1 and Gibosi,
> 
> How great differences in SQ have you found between different C3GS tubes?


 
  
 Hi A11.
  
 Gibosi may well be right re the different brands (ie all Siemens), and yet JAC Music imply others are not...and charge accordingly! I personally smell a rat, lol!!
  
 From what I can recall, I believe I _did_ notice a slight improvement in the 'S' version over the standard one...apparently they were selected for higher transconductance readings. I did notice also a very slight difference in the top of the glass - the 'S' being slightly flatter. But perhaps this is down purely to different batches/years...who knows?!


----------



## Acapella11

> Originally Posted by *gibosi* /img/forum/go_quote.gif
> To the best of my knowledge, all C3g tubes were manufactured by Siemens, so there is nothing to be gained by rolling through the different "brands".
> Good news for your wallet!


 
  
 Good news indeed! 
	

	
	
		
		

		
			




  


hypnos1 said:


> Hi A11.
> Gibosi may well be right re the different brands (ie all Siemens), and yet JAC Music imply others are not...and charge accordingly! I personally smell a rat, lol!!
> From what I can recall, I believe I _did_ notice a slight improvement in the 'S' version over the standard one...apparently they were selected for higher transconductance readings. I did notice also a very slight difference in the top of the glass - the 'S' being slightly flatter. But perhaps this is down purely to different batches/years...who knows?!


 
  
 Hi Hypnos1, my Siemens tube packaging says C3GS but the top of the black casing says C3G, so I am not sure what they really are.
  


> Time to relax and enjoy a little tube glow.


 
 I understand ´the Sophia Princess 247B are very nice 6SN7 tubes. How much have you paid for those? You must be looking forward to the 6SN7 adapters now. 
  
  
 Just to be sure, these are the 6SN7 power tube adapters? http://www.ebay.com/itm/1x-5687-to-6N6-6N1-6N2-6N6-6N11-ECC88-E88CC-Vacuum-tube-adapter-socket-converter-/321472393335


----------



## TrollDragon

The 274b is a rectifier, not a 6SN7... 

http://www.sophiaelectric.com/pages/se/274b.htm


----------



## Acapella11

trolldragon said:


> The 274b is a rectifier, not a 6SN7...
> 
> 
> 
> ...


 

 Oops


----------



## Oskari

acapella11 said:


> Just to be sure, these are the 6SN7 power tube adapters? http://www.ebay.com/itm/1x-5687-to-6N6-6N1-6N2-6N6-6N11-ECC88-E88CC-Vacuum-tube-adapter-socket-converter-/321472393335


 
  
 Oops?


----------



## hypnos1

acapella11 said:


> Good news indeed!
> 
> 
> 
> ...


 
  
 Ciao A11.
  
 Fear not, they ARE 'S's...strangely enough it's only noted on the box and NOT on the casing, or tube...weird!


----------



## gibosi

acapella11 said:


> Good news indeed!
> 
> 
> 
> ...


 
  
 Mine have the same packaging - C3g-S, but the black casing says C3g. Evidently this is normal. I have read that the C3g-s also have "Post" printed on the side, and the standard C3g do not. This is true of the two pairs I have one C3g-s and the other C3g, but I do not know if it is true for all.
  
 And the link you posted is to allow a 5687 to be plugged into your power sockets. If you want to use 6SN7's, you will need an adapter similar to this one:
  
 http://www.ebay.com/itm/1pc-6SN7-6H8C-6N8P-CV1988-B65-VT231-TO-ECC88-6922-6DJ8-6N6-6N11-tube-adapter-/201083508552?


----------



## vic2vic

gibosi said:


> Mine have the same packaging - C3g-S, but the black casing says C3g. Evidently this is normal. I have read that the C3g-s also have "Post" printed on the side, and the standard C3g do not. This is true of the two pairs I have one C3g-s and the other C3g, but I do not know if it is true for all.


 
  
 Some C3Gs with C3G on the black casing have a very small S drawn by hand at the bottom side of the case, on the non black painted area. Probably they were measured as "exceptional" after the encasing, so marked as "s" at a later stage of production.
  
 Regarding the "Post" print to differentiate between the 2 models, here are some examples of C3G (o S) with Post printing:
http://f.hatena.ne.jp/platycerus/20100618104035
http://www.ab.auone-net.jp/~pal/c3g.JPG
  
 So probably all C3Gs have Post on the side, but having Post on a C3G is not enough to confirm it's a C3Gs


----------



## gibosi

vic2vic said:


> Some C3Gs with C3G on the black casing have a very small S drawn by hand at the bottom side of the case, on the non black painted area. Probably they were measured as "exceptional" after the encasing, so marked as "s" at a later stage of production.
> 
> Regarding the "Post" print to differentiate between the 2 models, here are some examples of C3G (o S) with Post printing:
> http://f.hatena.ne.jp/platycerus/20100618104035
> ...


 
  
 Yes! I found the little hand-written "s" on my C3g-s. 
  
 However, I have a pair of regular C3g which do not have "Post" written on the sides of the can. They have only the number "383" written on the side. But from your pictures, I would agree, "Post" is not a reliable way to tell them apart. Thanks for the info.


----------



## MIKELAP

acapella11 said:


> Good news indeed!
> 
> 
> 
> ...


 
 The 274b goes on my wa6 amp along with a pair of adapter i got from Woo to use 6SN7 I am also  waiting for 6SN7 adapters for the LD to use 6SN7 as power tubes not shure they will work i had bought them for another amp  if anybody knows let me know they are 6SN7 TO 6CG7. Thanks


----------



## mordy

Hi Mikelap,
  
 Those adapters are the correct ones and will work just fine for the 6SN7 tubes - have them myself. Just plug the tubes into the adapter and then the whole thing into the LD amp. If you have the decorative rings the adapter is too wide to fit inside the ring, and you need two 9pin extenders.The 9pin extenders are narrow enough to fit inside the rings.
  
 Tube + adapter + 9pin extender. In order to make it easier to find the pin holes in the socket I applied a little piece of colored tape on the 9pin extender to indicate the orientation.


----------



## MIKELAP

mordy said:


> Hi Mikelap,
> 
> Those adapters are the correct ones and will work just fine for the 6SN7 tubes - have them myself. Just plug the tubes into the adapter and then the whole thing into the LD amp. If you have the decorative rings the adapter is too wide to fit inside the ring, and you need two 9pin extenders.The 9pin extenders are narrow enough to fit inside the rings.
> 
> Tube + adapter + 9pin extender. In order to make it easier to find the pin holes in the socket I applied a little piece of colored tape on the 9pin extender to indicate the orientation.


 
 Would it really matter if the adapters go let say only halfway in what do you think ?


----------



## MIKELAP

Would you be suspicious of these tubes the glass inside looks cloudy around the edges they seem to be chrome tops.is that normal suppose to be badboys . What to you guys think would you buy these tubes.?


----------



## gibosi

mikelap said:


> Would it really matter if the adapters go let say only halfway in what do you think ?


 
  
 No harm in trying. 


mikelap said:


> Would you be suspicious of these tubes the glass inside looks cloudy around the edges they seem to be chrome tops.is that normal suppose to be badboys . What to you guys think would you buy these tubes.?


 
  
 These look perfectly fine to me. I have noticed that tubes from the late 1940's and into the early 1950's have this rather dirty and uneven looking getter splash. In the later tubes, the getter splash became much neater, with a very clear and even edge.
  
 What you have there are the classic Sylvania 6SN7GT "Chrome Domes", characterized by a very uneven getter splash that typically covered more than half of the glass. Might fine tubes.


----------



## MIKELAP

gibosi said:


> No harm in trying.
> 
> These look perfectly fine to me. I have noticed that tubes from the late 1940's and into the early 1950's have this rather dirty and uneven looking getter splash. In the later tubes, the getter splash became much neater, with a very clear and even edge.
> 
> What you have there are the classic Sylvania 6SN7GT "Chrome Domes", characterized by a very uneven getter splash that typically covered more than half of the glass. Might fine tubes.


 
 Thanks good to know . just got mysel 4 - 1957Sylvania GTB now checking out aCV593 very nice tube it seems . man that exchange is killing me not living  in the right country .


----------



## JazzVinyl

gibosi said:


> Yes! I found the little hand-written "s" on my C3g-s.




Confirmed hand written "s" are present on my pair, as well...

.


----------



## mordy

Hi Mikelap,
  
 Those adapters are not going to in halfway into the the LD MKIII. I tried, but the the rings block the adapters from seating into the pin sockets, and you cannot get good contact. The 9pin extender sockets can be bought for less than $7 for four of them.
  
 Been there, done that, and no, it did not work without the extenders. Unless you take apart the MKIII and open up the chassis and reach in with an Allen wrench to loosen up the set screws for the rings, you will need the extenders. Everything is so crammed in there that I wouldn't even try.


----------



## JazzVinyl

MIKELAP said:
			
		

> I am also  waiting for 6SN7 adapters for the LD to use 6SN7 as power tubes not shure they will work i had bought them for another amp  if anybody knows let me know they are 6SN7 TO 6CG7. Thanks




I am using 6SN7's as powers with that adapter on my LD MK IV and I really like them, a lot...

Hoping you will make me a pair of C3g to 6Ak5 adapters, Hint hint hint... 

.


----------



## mordy

My two C3gS tubes from Superdux have printed on the sides Post
                                                                                                Gabl
  
 and somebody wrote a little S on the side of the silver metal part of the socket with a black marker. The top of the metal can has the number 35062 twice.
  
 (August 1962?)


----------



## BGRoberts

mordy said:


> Hi bbm,
> 
> My LD MKIII sits on three 1" aluminum cones stuck to the bottom of the amp with bluetack (generic). I use two discarded 12V computer fans, 3" and 4" . These fans can be bought new for $ 4-5.
> 
> ...





HI mordy , 
Any pictures of your setup? I'm having a hard time visualizing it. 
~BG


----------



## MIKELAP

jazzvinyl said:


> I am using 6SN7's as powers with that adapter on my LD MK IV and I really like them, a lot...
> 
> Hoping you will make me a pair of C3g to 6Ak5 adapters, Hint hint hint...
> 
> .


 
 Waiting for parts to make first pair the problem  will be to make them as short as possible need a one piece body for that with the right dimension for the sockets or else a 2 piece adapter with all the sockets installed  ready to go will be about 13/4¨ tall +the tube maybe a bit less . with one piece adapter it could possibly be as short as 1 inch tall thats the goal may be will need to have them machined will see when i get parts  Heres a ruff 2 piece construction i started   with regular octal socket the loctal socket seems to be thinner  than the octal socket .


----------



## hypnos1

vic2vic said:


> Some C3Gs with C3G on the black casing have a very small S drawn by hand at the bottom side of the case, on the non black painted area. Probably they were measured as "exceptional" after the encasing, so marked as "s" at a later stage of production.
> 
> Regarding the "Post" print to differentiate between the 2 models, here are some examples of C3G (o S) with Post printing:
> http://f.hatena.ne.jp/platycerus/20100618104035
> ...


 
  
 Well, well...indeed there _are_ little 'S's on the canister - I stand corrected! In my eagerness to free the (not-so-) little beauties from their (protective and potentially grounded) prison, I completely missed 'em...well spotted v2v...
  
 That they were individually handwritten denotes a very admirable dedication to quality - in my book, anyway..


----------



## d4rkch1ld

Yesterday got some 6N6P tubes and got a little suprise inside those 4 boxes. Here is the pic.

  

  
 One of four tubes is missing chrome top. Is it safe to use that tube?


----------



## gibosi

d4rkch1ld said:


> Yesterday got some 6N6P tubes and got a little suprise inside those 4 boxes. Here is the pic.
> 
> 
> 
> One of four tubes is missing chrome top. Is it safe to use that tube?


 
  
 That is very interesting to see this much variation among these tubes. It is not uncommon to see tubes with no visible getter splash, but still there is likely a very light coating. And just enough that if the tube had a leak, the top would be white. So my opinion is to it should be fine.


----------



## mordy

Hi BGRoberts,
  
 My LD amp sits with three aluminum cones on a MDF shelf on an equipment rack. The rack itself sits with spikes on a hardwood floor. Each shelf sits on four tabs within a metal frame. Each tab has a round marble between the tab and the shelf. All this is supposed to eliminate unwanted vibrations. Don't know what works best individually or in combination, but I do not have any problems with microphonics. What my set up is lacking in looks is made up by practicality.
  


 Here is the equipment rack with various contents. The blue, yellow and white plastic ties hold the two fans in place. On the top left is a temperature probe whose tip touches the transformer housing. On the shelf underneath is the Little Dot MKIII standing on three footers. On the transformer housing an 15A voltage regulator is attached with two rubber bands. The two white pieces behind it are wooden chopsticks to make a space between the voltage regulator mounting plate and the transformer housing to allow for better air circulation and cooling.
 To the left of the amp on the shelf is a mounting board for two voltage regulators that supply power to one of the fans and the driver tube, seen on the bottom suspended by wires to the two Vector adapters (less hum).
  


 Here the shelf is lifted up to show the arrangement with a marble to cancel out vibrations.
  


 Here are the 80's aluminum cones attached with generic bluetack to the bottom of the LD amp.
  

This is the 12V 4" fan mounted above the amp.
  

 Here is a close up of the temperature probe. Actual temperature of the transformer housing today with the amp in operation is 78F. Room temperature is 67F. On a hot day with a room temperature of around 76F with A/C on the temperature may go up to 89F.
  
  
  


 Here is the second fan, also mounted above the amp. It is a 12V 3" computer fan from a busted power supply. It was chosen because it is quiet. Rather than blowing air on the amp, both fans draw the hot air away from the amp. Under the fan are seen two 6080WA Sylvania 2.5A power tubes. How do these octal tubes fit into the 9pin sockets on the LD?
  


 Since the octal to 9pin adapters are too wide to fit inside the decorative rings on the LD MKIII, a 9pin socket extender is needed. The little red strip marks the orientation of the adapter for easy insertion. The octal adapter goes into the extender, and the tube - you guessed it - goes into the octal adapter.
 Since the 6080 tubes use much more current than the amp can provide, an external 15A voltage regulator is connected to the heaters of the tubes. On the left of the extender you can see a wire coming out. A hole was drilled in the bakelite of the extender. The heater pins were desoldered and removed (the extender comes apart easily with one screw) and the wires soldered onto the pin tabs inside the extender. If you use 6SN7/6SL7 octal tubes as power tubes no external power supply is necessary.
 The 15A voltage regulator is powered by a 430W computer power supply. I found that that a beefier power supply resulted in better sound.
  


 This is the15A voltage regulator. The smaller voltage regulators can be bought with voltage readouts, but for some reason these come without - you will need a simple voltage meter to set the voltage to 6.3V using a little set screw on the voltage regulator. For some reason the voltage reading taken at the tube pins always is lower than at the voltage regulator itself, but may differ a little between different tubes. Usually, with the 6080s, I have to set the voltage to around 7V to get 6.3V at the tube itself. The large heat sinks never get warm in use.
  
 What else is there to describe? The fans run on 12V, and I used whatever I had on hand. One is powered by a 12V wall wart from an old portable phone, the other shares the 12V PC power supply with the heaters for the power tubes. The 12V driver tube uses an old laptop 19.8V power supply via a voltage regulator.
  
 This set up is very flexible, and I can use all kinds of driver/power tubes that use different voltages - 6V, 7V, 8V, 12V - no problem.
  
 It's been a long journey, littered with tubes relegated to the dust pile, but very rewarding.....


----------



## mordy

Hi d4rkch1ld,
  
 The purpose of the getter flash is only one - to get rid of any oxygen left in the tube to create a hard vacuum. The size and color of the getter flash does not matter, and different manufacturing methods result in different amounts of getter flash or color; or no flash at all (cleartop tubes). {Side getter or bottom getter tubes have the flash on the side or the bottom, but although they have clear tops, I am not referring to them as cleartop tubes.}
  
 If the vacuum is lost, the getter usually turns white, and the tube is finished.
  
 If your tube works I would not worry.


----------



## TrollDragon

mordy said:


>


 
  
 Way too much crazy action going on there... I'll stick with the basics as it has a better _*WAF*_.


----------



## mab1376

d4rkch1ld said:


> Yesterday got some 6N6P tubes and got a little suprise inside those 4 boxes. Here is the pic.
> 
> 
> 
> ...


 
  
 It may indicate a leak in the glass. Its what happened to one of my 6AV6 when i clipped the pin and it cracked the glass.
  
 Not saying its definitely the issue, but a possibility.


----------



## MIKELAP

mab1376 said:


> It may indicate a leak in the glass. Its what happened to one of my 6AV6 when i clipped the pin and it cracked the glass.
> 
> Not saying its definitely the issue, but a possibility.


 
 Thats what i was thinking at first with these tubes , it looked suspicious .


----------



## mordy

Hi TD,
  
 I agree with you that your system looks miles better than mine. However, I don't let anybody into my listening room/office/junk collection, and my wife hates the music I am listening to, so WAF is not a factor here.
  
 Aesthetics don't bother me, and the sound of  my system is superb. Waiting to see if the C3g will be an upgrade.....


----------



## hypnos1

trolldragon said:


> Way too much crazy action going on there... I'll stick with the basics as it has a better _*WAF*_.


 
  
 Hey TD...does this not have a fair degree of *WAF?*....
  

  
 ...Not to mention a sound _way_ better...and well within your capabilities, mon ami!


----------



## TrollDragon

hypnos1 said:


> Hey TD...does this not have a fair degree of *WAF?*....
> 
> 
> 
> ...


 
 Yes indeed WAF is strong with this one...


----------



## TrollDragon

mordy said:


> Hi TD,
> 
> I agree with you that your system looks miles better than mine. However, I don't let anybody into my listening room/office/junk collection, and my wife hates the music I am listening to, so WAF is not a factor here.
> 
> Aesthetics don't bother me, and the sound of  my system is superb. Waiting to see if the C3g will be an upgrade.....


 
 All is good then, my amp sits out front and center so I have to keep the self contained part up.
  
 I was asked how long those "Big Ugly Headphones" were going to stay up there... 
	

	
	
		
		

		
		
	


	




 
  
 Sacrilege I tell you, Sacrilege.


----------



## hypnos1

trolldragon said:


> All is good then, my amp sits out front and center so I have to keep the self contained part up.
> 
> I was asked how long those "Big Ugly Headphones" were going to stay up there...
> 
> ...


 
  
 I feel for you, TD...some people in a household just have _*NO SOUL!!  *_


----------



## i luvmusic 2

mikelap said:


> jazzvinyl said:
> 
> 
> > I am using 6SN7's as powers with that adapter on my LD MK IV and I really like them, a lot...
> ...


 
  You can get a 1'' to 1/2'' reducer  then cut the 1''part if you need to.What you have there is 3/4'' to 1/2''  and 1'' to 3/4'',8 pins fits in 1'' coupling and 7 pins fits in 1/2'' coupling 9 pins fits on 3/4'' coupling.If you are Having a hard time getting the 1'' to 1/2'' PM me.


----------



## gibosi

6SN7M
  
 http://www.ebay.com/itm/PAIR-2-6SN7M-RCA-NOS-BRASILIA-MOST-UNIQUE-6SN7-VERY-RARE-LIMITED-SUPPLY-/311146512544?
  
 It is my understanding that these are simply RCA 6CG7s stuffed into metal cans....


----------



## BGRoberts

So many ingenious ideas! 
Thanks for all the effort to share them, mordy !






mordy said:


> Hi BGRoberts,
> 
> My LD amp sits with three aluminum cones on a MDF shelf on an equipment rack. The rack itself sits with spikes on a hardwood floor. Each shelf sits on four tabs within a metal frame. Each tab has a round marble between the tab and the shelf. All this is supposed to eliminate unwanted vibrations. Don't know what works best individually or in combination, but I do not have any problems with microphonics. What my set up is lacking in looks is made up by practicality.
> 
> ...


----------



## Acapella11

trolldragon said:


> The 274b is a rectifier, not a 6SN7...
> 
> 
> 
> ...


 


gibosi said:


> Mine have the same packaging - C3g-S, but the black casing says C3g. Evidently this is normal. I have read that the C3g-s also have "Post" printed on the side, and the standard C3g do not. This is true of the two pairs I have one C3g-s and the other C3g, but I do not know if it is true for all.
> And the link you posted is to allow a 5687 to be plugged into your power sockets. If you want to use 6SN7's, you will need an adapter similar to this one:
> http://www.ebay.com/itm/1pc-6SN7-6H8C-6N8P-CV1988-B65-VT231-TO-ECC88-6922-6DJ8-6N6-6N11-tube-adapter-/201083508552?


 
 So, I had two Oopses. 
	

	
	
		
		

		
		
	


	




 Looking actually at the names of the socket adapter links, makes it quite obvious. Just got a bit confused by the new tubes available for the LD. Thanks for the corrections. 
	

	
	
		
		

		
		
	


	



 it
 I will look for the "s" on my C3g. Brilliant, you found it. This weekend, I am away from my kit, so I will check Monday.
  
 Mordy, Thank you for that Link before to the C3g history, very interesting.


----------



## bbmiller

oskari said:


> bbmiller said:
> 
> 
> > Are there any databases which lets you search for tubes by pin arrangement? Do pin arrangements of vacuum tubes have names that can be search for in any way? On the Internet? On a page itself if you search for the recognizable pin arrangement name, say in certain very good datasheets?
> ...


 
 OK that software you recommended runs on my Windows 7 computer just fine. Thanks!


----------



## mordy

Hi G,
  
 Probably you already saw this comment from 2011 about the metal tubes:
  
_"comment about late production Brazilian made RCA 6SN7M after I found out that someone is currently selling them on eBay for $88 (!) a pair. A few years ago I got a handful of them for nothing in a dumpster store. I understood they are not true 6SN7 after a friend of mine told me he had opened the metal can to find out that there was miniature 6FQ7A/6CG7 inside. Wires had been spot welded to make for the pin conversion. While it looked like a neatly done factory job, I doubt the metal can around the tube will help heat exchange, so it should probably run a little hotter than if it was at open air. Electrically, the interchangeability seems very good, as long as one consider that the smaller plates of the 6FQ7A/6CG7 should not withstand the very same power dissipation._
_Now I wonder how these odd late Brazilian 6SN7M got reach to the States. Mine are still on the store. Cheers for all,_
_Flavio, from Brazil._"
  
 The pair you referenced went for $148 - excellent marketing! You can pick up 6CG7 tubes for a couple of dollars. I have some sold by Sears - Satisfaction Guaranteed or your money back.....


----------



## mordy

Hi BGRoberts,
  
 Thanks for your comment. I forgot to point out that except for soldering four wires inside the 9pin extenders everything else goes together with a small screwdriver.


----------



## Acapella11

hypnos1 said:


> Hey TD...does this not have a fair degree of *WAF?*....
> 
> 
> ...Not to mention a sound _way_ better...and well within your capabilities, mon ami!


 
  
 Hi Hypnos1,The setup looks really nice. You have done those adapters very well. Do you have a guide for that?
 I think this question has come up before, but since you are using GEC 6AS7G as power tubes, I guess you are using an external power supply. How have you modified the amp further to route the extra wiring?
  


trolldragon said:


> Way too much crazy action going on there... I'll stick with the basics as it has a better _*WAF*_.


 
  
 Hi Trolldragon, the HP-stand is cool. Which LCDs are those? I am guessing the LCD 3 you auditioned. They would not be the typically matching headphones for the LD. Does the combination actually sound alright? Which HPs do you normally use with the LD?


----------



## TrollDragon

acapella11 said:


> Hi Trolldragon, the HP-stand is cool. Which LCDs are those? I am guessing the LCD 3 you auditioned. They would not be the typically matching headphones for the LD. Does the combination actually sound alright? Which HPs do you normally use with the LD?


 
 Yes those were the non Fazor LCD-3's I auditioned.
 They have the specifications of 110Ω and 93dB / 1mW which does require some grunt on an output to bring out the best in them. The LD does have enough power to drive them quite nicely, but they were much better suited to the Burson or even driven from speakers taps out of an Emotiva Mini-X A-100 at 50W per side. (There is a large thread here on using speaker amps as headphone amps.)
  
 My daily drivers are the beyerdynamic DT880 Pro's and the Fostex T50RP (DVB3 Mod). The LCD-3's have some of the most amazing bass I have ever heard in a headphone, if you want a truly exceptional headphone with incredible speed, clarity and dynamic range then you really need to try the LCD-3's in a quite environment as they are very open.  The weight might be a issue for some who are a tad spleeny as they weigh around 1.5lb's but the thickness of the lambskin leather pads is just heavenly!
  
  
  
 That was an incredible few weeks with a truly amazing headphone!


----------



## hypnos1

acapella11 said:


> Hi Hypnos1,The setup looks really nice. You have done those adapters very well. Do you have a guide for that?
> I think this question has come up before, but since you are using GEC 6AS7G as power tubes, I guess you are using an external power supply. How have you modified the amp further to route the extra wiring?


 
  
 Hi A11.
  
 Thanks...I'm lucky enough that the MKIVs don't have those hard-to-remove rings, so the adapters can be somewhat neater, lol!
  
 With these particular C3g ones, I soldered the wires (that also act as the pins) direct to the tube's pins, and without the metal base looks even neater...BUT, of course, is much riskier - you only have one shot when everything is finally sealed up!! So it's not recommended if new to the task. I did post a guide many moons ago, and will try to find it if you're feeling brave! 
	

	
	
		
		

		
			




  
 I am actually in the process of making a conventional plug-in adapter, and will be posting a pictorial very soon...when I'm out of mourning!...see further posting later...(after breakfast..)...
	

	
	
		
		

		
		
	


	



  
 As for the 6AS7G adapters, no fancy mods to the amp for extra wiring I'm afraid...it's just that you can't see the black wires very clearly in the photo! When I made these adapters, I routed the heater wires out the back of them and they blend quite nicely into the top of the amp case 
	

	
	
		
		

		
		
	


	




. Once again, with those MKIII rings _you_ need an extra extender, and mordy achieved the same sort of thing by drilling into said extender to access the relevant wires (he's made several posts on this). Then you can get a 6SN7 to 6CG7 adapter for the 6AS7G/6080 (not using the LD's heater pins, of course!) - much easier than making 'em.
  
 Recent posts should have most of the info you need, but of course (as you already know, lol!) any further questions will soon be answered by all of us here...(Life should be much easier when the Feliks-Audio amp arrives!!).


----------



## hypnos1

Further to my previous post, those with a nervous disposition should look away now...I've killed one of my (new) beloved C3GSs!!!
  
 Having just completed the first (conventional) adapter, while testing it I must have pushed/pulled the tube just wrong and damaged it enough so that as it heated up...POP/CRACK...
	

	
	
		
		

		
		
	


	




. I should have known better and been more careful, as it was removed from its protective canister...and so...*A TIMELY WARNING* to those who, like me, prefer to expose the tube - be *EXTREMELY** CAREFUL* when fitting into the adapter (and once in, KEEP it in, lol!).
  
 And so my last remaining spare will have to go back into its prison while testing adapters - but will come straight out again afterwards! 
	

	
	
		
		

		
		
	


	




.
  
 Below -  the results of my carelessness...
	

	
	
		
		

		
		
	


	



  
EDIT...Once again those pesky gremlins have been messing with my brain...despite being ULTRA careful, it has in fact turned out to be the ADAPTER after all, so perhaps the tube is not actually quite so fragile...further info below...


----------



## Oskari




----------



## Rossliew

Currently listening to Verite "Strange Enough" streamed on Spotify premium with the LD3 using Raytheon 6SN7s / Electro Harmonix 12AU7 gold pins - the HD600s never sounded so spacious and full of energy, hardly veiled at all (this with copper cables). Treble is extended and sparkling like the best fizzy drink! Bass is deep and hard hitting. Really liking this combo.
  
 Can't wait for some RCA 12AU7s incoming to try out..


----------



## mordy

Hi hypnos 1,
  
 Sorry to hear about losing one of the C3g tubes - I guess these things happen to all of us....
  
 Here is another train wreck:
  

  
 I had just taken a picture comparing this splendid and rare Chatham 6AS7G tube to a subminiature tube. While uploading the picture I accidentally knocked my desk and the tube rolled off and fell on the floor. I found out that the glass envelope is really fragile. At least the sub miniature tube can withstand 250G impact.
  
 Oh well......


----------



## hypnos1

mordy said:


> Hi hypnos 1,
> 
> Sorry to hear about losing one of the C3g tubes - I guess these things happen to all of us....
> 
> ...


 
  
 Thanks mordy...and commiserations for _your_ mishap. This hobby certainly does have its perils, lol!
  


oskari said:


> _no_




  
 Oh Oskari...as if I weren't already close to tears!.. How did you know I _love_ melancholic music - that is one beautiful piece.
  
 But what accompanies a SECOND tragedy?...Let me explain...
  
 Actually, it turns out that the culprit was _not_ my clumsiness after all, but the first ADAPTER!!... Having tested the second one, I re-checked the first and *C3gS #2 DIES!*...Unbelievable...I was SO meticulously careful at all stages of production.
  
 After racking my brains(?!) for a while, I finally narrowed it down to something strange that happened while filling the adapter with resin (a make I hadn't used before) - a strange smoke-like substance flew up, and the metal case got REALLY warm. At the time I thought it was simply part of the curing process, so I wasn't unduly worried. But I now realise it must have reacted VERY badly with a putty-like substance I used as an insulator, and caused massive internal damage.
  
 So it just goes to show that no matter _how_ careful you are, the unexpected can creep in and ruin all your efforts...
  
 Ah well, I suppose I should look on the bright(?!) side - at least it didn't blow the amp and/or headphones, lol!!
  
 Now let me go and sob a while...


----------



## Oskari

hypnos1 said:


> Ah well, I suppose I should look on the bright(?!) side - at least it didn't blow the amp and/or headphones, lol!!


 
  
 Right you are! Sorry about the funeral music.


----------



## i luvmusic 2

Crap! someone deleted my POST,I'am wondering if they noticed/read the bottom part of my POST.


----------



## hypnos1

oskari said:


> Right you are! Sorry about the funeral music.




  
 From the sublime to the ???????
	

	
	
		
		

		
		
	


	



  
 I must admit, O, that is one of the best Python moments...a good note on which to hit the sack, lol!


----------



## bbmiller

> Originally Posted by *gibosi*
> We have to remember... Everyone's ears are different. Even with the same tubes, same headphones and same electronics, one person will love them and another will find them so-so. As Mordy reminded us some time ago, tubes are like ice cream. Everyone has a different favorite flavor.


 
 OK as Morty pointed out to us quite a while ago everybody has a favorite flavor, but I am wondering if you all are ready to accept that I like the disgusting topping I like.
  
 The disgusting topping I like is to leave my little dot IV MK amplifier on 24/7. I know this is not easily accepted since I have talked elsewhere on these Head-FI forums about my 24/7 preference and was greeted with disbelief. But I made it one of the points to check out when I went to the Rocky mountain audio Fest. I asked the question to Head-FI  founder Jude Mansilla and he said some people find it takes an awful long time for tubes to get to their maximum sound and that this happens depending on the tubes. He has friends that run their tube amplifiers 24/7 and he does it himself sometimes if he knows he is going to be reviewing a certain tube amp a lot.
  
  I also talked to the Schiit company amplifier designer and told them what I was doing with the little dot branded tube amplifier I am using now. I told him I was running it 24/7 and it sounds better that way. And asked him if he believes that his brand of amplifiers would behave the same. He said he believed that running them 24/7 would improve their sound but it would be expensive. I also spoke to another amplifier engineer who agreed and the chief guru of listen up audio stores, who may have the biggest operation of audio equipment sales in Colorado USA, and after talking to him quite a lot and becoming friendly he said that in their store they run the tube amps 24/7 because they sound better that way and sell more amps that way. I was wondering if that is ethical if the customers do not know that, but I very much heard it just the same.
  
 So I think my predilection that running my amplifier 24/7 makes them sound better is at least real to me and may be real two other people as well.
  
 Well after delaying my purchase  6HM5 EC900 Yugoslavian driver tubes, to see what I could learn at the Rocky mountain audio Fest first, I finally ordered them and a have arrived. I ordered the lot of 10 MIKELAP recommended to me and I had none of the trouble he had with two broken tubes. They must've taken MIKELAP advice and improved the way they pack them greatly. They certainly seemed well packed.
  
 Well when I started listening to them they immediately gave me a better soundstage the instrument placement was more easily recognized by my ears, but initially they lack the warmth when I listened human vocals or brass instruments I have come to love when I was listening with the stock driver tubes after they had been on for over 24 hours. Well the same beautiful increase in warmth came with a full 24 hour wait with these Yugoslavian tubes. I now love the sound I'm hearing and could love this kind of sound forever, but at the burnout rate that the stock power tubes might burn out at if I continue burning them 24 seven I think at my income level I will need to find a cheaper alternative.
  
 I can see a cheaper alternative being tubes that aren't even that cheap, but you can burn for 10,000 hours or tubes that are cheap. I am thinking that this will leave out the type of power tubes that require an external power supply heater since those would either be expensive tubes or would not last 10,000 hours, but abuse me of this belief if it is wrong.
  
 I have ordered my octal converters for the power tube sockets and expect them any day now. I do not necessarily need to ever use them, but will be looking for more economical power tubes in what ever size I can make work in my little dot IV MK amplifier. So what you are previous recommendations to me change in any way in light of these preferences on my part. Are there such things as power tubes which if you only buy two are expensive, but are also the ones which can be most often board in big lots at cheap prices.
  
 I could try a few different power tubes even if they were not that  cheap if I thought later on these are the very power tubes which can be purchased in big lots at cheap prices. Incidentally by 10 Yugoslavian driving tubes cost me only $45 US.
  
 Well there is one more question I have what if anything I have to do to my little dot IV MK amplifier to make it ready for 24 hour operation. I know from my experience that this can be done somewhat, but is the only thing I need to do to ensure it can be done for a long long time is have the cathode resistors on hand, at a higher wattage, shown in the picture below along with possibly there bypass capacitors at a higher dielectric breakdown voltage then comes standard?
  

  
 If one was to have to replace those cathode resistors and there bypass capacitors what would be the easiest way to get to them. It seems they must be closest to the front panel where the volume control sets rather than the rear panel and perhaps you can unscrew the breastplate which sits next to the tubes and gain access to whatever you have to on solder to make the printed circuit card removable to work on it. Does this sound right. Has anybody worked on that printed circuit card and can give me advice on how to remove it if necessary. I am not looking to remove it now, but would love to be forearmed with the information should the necessity arrive.


----------



## TrollDragon

To do any work on the LD MK IV board you will need to remove it from the chassis, that picture you posted is of my MK IV board.

I will post instructions for you later today when I am not on the mobile browser.

My only concern with running the LD 24/7 is a power transformer failure. You can replace any part on the board easily from any electronics supplier, the transformer is custom wound for LD and I doubt you would be able to purchase one if it fails.

This is not a Schiit amp or any other type of higher end tube type amp. It is an inexpensive Chinese built amp with typical Chinese stock quality parts, so one cannot really compare build quality or longevity with other brands.

The best person you could ask about running it 24/7 would be Little Dot themselves.


----------



## MIKELAP

trolldragon said:


> To do any work on the LD MK IV board you will need to remove it from the chassis, that picture you posted is of my MK IV board.
> 
> I will post instructions for you later today when I am not on the mobile browser.
> 
> ...


 
 Dont they recommend no more than 8 hours at a time !


----------



## MIKELAP

This is from LD MK3 guide book


----------



## JazzVinyl

hypnos1 said:
			
		

> But what accompanies a SECOND tragedy?...Let me explain...
> 
> Actually, it turns out that the culprit was _not_ my clumsiness after all, but the first ADAPTER!!... Having tested the second one, I re-checked the first and *C3gS #2 DIES!*...Unbelievable...I was SO meticulously careful at all stages of production.
> 
> ...




I am sorry that you had two die on you, hypnos1...

Especially while trying to make a guide for us....!

I have had one of my two C3gS's die...I know it received no rough treatment. Just regular insertion/removal while I tried to make a working adapter....both of mine are still in the shields.

Perhaps they are not as robust as we thought.

.


----------



## superdux

don't worry folks, i'll have around 20 C3G and 8 C3GS to sell in about a week, so you can do further testing.I'm not sure if NOS but will sell cheap anyway.


----------



## TrollDragon

mikelap said:


> Dont they recommend no more than 8 hours at a time !


That is what they recommend in my manual as well. There must be something to it otherwise it would not be outlined in its own box so it wasn't missed.

But it is just like a temporary spare tire on a car with the big yellow writing of 80km/h maximum. I see people all the time going up the highway at 110km/h with one mounted on their vehicle...

People like to roll the dice of fate. If your amp burns out you just buy another, which for some would be a minor inconvenience or an easy reason to upgrade, I don't have that kind of disposable income so I don't taunt the gods of fate.


----------



## mordy

Hi bb,
  
 I have run my amp for 48 hours straight without any problems - I think the worry is about heat build up, and that can be taken care of easily with external fan cooling and very inexpensively.
  
 About longevity of tubes, some tubes are designed for 10,000 hours of use. These tubes have different names depending on the manufacturer. Amperex uses PQ (Premium Quality), GE 5 Star (7,500-10,0000, Mullard Millenium, the Siemens Cg3 is rated for 10K hours, and Russian tubes use the DR designation.
  
 Octal 6SN7 tubes and the like are supposedly rated for 5,000 hours. Russian EV tubes the same.
  
 The average tube should last 2,000 to 3,000 hours.
  
 I have personally not found tubes improving much in sound after 1/2hr - 1 hr warm-up, but burn in makes a big difference. Some tubes are burnt in after 30 hours, others 50, and yet others 100 hours or more.
  
 In general, I found the sound to be better at night when less electric appliances are used and less RF interference.
  
 If you ran your amp 24/7 you should get at least 6 months of use from most tubes; and the longest lasting ones at least 18 months.


----------



## JazzVinyl

> I have personally not found tubes improving much in sound after 1/2hr - 1 hr warm-up, but burn in makes a big difference. Some tubes are burnt in after 30 hours, others 50, and yet others 100 hours or more.


 
  
 This has been my experience as well. 
   
.


----------



## JazzVinyl

superdux said:


> don't worry folks, i'll have around 20 C3G and 8 C3GS to sell in about a week, so you can do further testing.I'm not sure if NOS but will sell cheap anyway.


 
  
 Good to know, thank you, superdux!


----------



## hypnos1

jazzvinyl said:


> I am sorry that you had two die on you, hypnos1...
> 
> Especially while trying to make a guide for us....!
> 
> ...


 
  
 Thanks JV...yes, this project has cost me dear already, both in time/effort _and_ financially...but I'm determined to get things stabilised if it kills me, lol! Thankfully, superdux is helping me out in this 
	

	
	
		
		

		
			





.
  
 Sorry to hear you too have lost a tube...we are pushing the boundaries rather a lot here, it would appear! Let's just hope the disasters are behind us...


----------



## sgbwill2

Hey again, I was just wondering, are EL80 tubes plug and play in the LD MK III and had anyone used them?


----------



## bbmiller

mordy said:


> Hi bb,
> 
> I have run my amp for 48 hours straight without any problems - I think the worry is about heat build up, and that can be taken care of easily with external fan cooling and very inexpensively.
> 
> ...


 
 Where do you perceive this heat build up to build up? Do you think lifting off the breastplate and putting it away someplace for safekeeping and occasionally blowing out your amplifier with some of that canned high pressure air without even shutting it down could work? I mean that canned high pressure air would just be for ridding your open amplifier from dust not for cooling. But removing the breastplate would give the inners of the amplifier on more easy way to exhaust heat.
  
 Also in regard to designations of long life on tubes do you think most to buyers are keenly aware of these designations and the price of these tubes adjust accordingly or are there long life best buys out there because many tube  buyers are not aware of the meaning of these designations?


----------



## gibosi

sgbwill2 said:


> Hey again, I was just wondering, are EL80 tubes plug and play in the LD MK III and had anyone used them?


 
  
 The EL80 is a pentode commonly used as a power/output tube. To use this as an output tube in the LD would require a very customized adapter. The LD is configured to use double triodes whereas this is a single pentode. First, you would have to convert the EL80 to a triode, and then you would have to design a converter to wire it into a double triode circuit. It can be done. However, this tube can put out *4 watts*. I have a very strong suspicion that this is way more than the the LD circuitry can safely handle...
  
 The safest way to use this tube would be as a pair of drivers. However, in addition to strapping them as a triodes, you will need an external PS, as these require 0.71A each.
  
 In my opinion, all this is too much work...


----------



## sgbwill2

gibosi said:


> The EL80 is a pentode commonly used as a power/output tube. To use this as an output tube in the LD would require a very customized adapter. The LD is configured to use double triodes whereas this is a single pentode. First, you would have to convert the EL80 to a triode, and then you would have to design a converter to wire it into a double triode circuit. It can be done. However, this tube can put out *4 watts*. I have a very strong suspicion that this is way more than the the LD circuitry can safely handle...
> 
> The safest way to use this tube would be as a pair of drivers. However, in addition to strapping them as a triodes, you will need an external PS, as these require 0.71A each.
> 
> In my opinion, all this is too much work...


 
 Thanks for clearing that up. I'm glad that there are knowledgeable people like you on this forum to help clear up things for noobs like me haha.


----------



## bbmiller

trolldragon said:


> My only concern with running the LD 24/7 is a power transformer failure. You can replace any part on the board easily from any electronics supplier, the transformer is custom wound for LD and I doubt you would be able to purchase one if it fails.


 
 If one want to get really scientific and use a temperature probe what type a temperature probe would one use. Could this be the same type a temperature probe computer overclockers use to figure out how to overclock their computer best?
  
 Could somebody post a picture of the power supply transformer I think there are two possible things I can think of being the power transformer in a little dot IV amplifier, but I am not sure which is the power transformer. I am also wondering how would you attach an appropriate temperature probe to this transformer? Would you use some sort of thermal paste to get good temperature transfer to your temperature probe attached to your transformer?

Would the one above be a very adequate temperature probe for testing are amplifiers? Or am I looking at something very different?

Do you think a temperature  gun like this one would be a far better way to make temperature measurements on our amplifiers?


----------



## mordy

Hi bb,
  
 I don't know much about heat build up, and my thoughts are just simple novice observations and have to be taken in that light. Heat is an enemy to electronics, so running cool is preferable for electronic equipment. What you are worried about in the amp is if something melts down or burns up. I don't know where the weakest link is, but people seem to be saying that resistors are vulnerable.
  
 If the amp gets too hot to touch I would think that it is a danger sign. The external metal parts of the amp may act as a heat sink to dissipate heat, so I don't know if it is a good idea to take off the face plate, and dirt build up cannot help either. Think about a home radiator that has many fins. The fins are there to increase the surface area to radiate heat into the room. If there is dust between the fins it will reduce the heat dissipation. (Just take a look under the front of your refrigerator -the radiator fins there require periodic cleaning. If the air circulation is impaired, the compressor may get too hot and break prematurely.) Many electronic items employ heat sinks to passively radiate away heat, and these may be augmented by fans to move away the hot air as well.
  
 The internal parts may have a very different temperature than the outside of the amp, and as said, I have no idea where the hot spots are. Empirically, I have found that keeping the chassis cool with external fans works well for for tubes using up to 2.5A. Tubes need to reach a certain temperature to operate properly, but his temperature varies a lot. Some tubes barely get warm, and others may cause burns if you just touch them by accident.
  
 Regarding the longevity of tubes, I don't know how much people are aware of this. That said, It seems to me that the most important attribute of any tube is that it sounds good. Having more than a touch of _Audiophilia Nervosa_ and constantly changing tubes, I have not been able to wear out too many tubes, so longevity is not a criterion for me, although a big plus if the tube sounds very good.
  
 I have not found any relationship between 10,000 hour rated tubes and sound quality.
  
 I am not worried about leaving the tubes on a long time, but leaving them on 24/7 seems excessive - I don't see the benefit of leaving them on when I am not listening. At times it seemed to me that the tubes got "tired" after being on a long time for burn in and didn't sound their best until I switched them off, waited,  and turned them on again - (could be related to the equipment?). The last comment is purely subjective and not intended as any criticism whatsoever; only my humble opinion.


----------



## i luvmusic 2

I think the best solution for you is to just transfer your LD into a chassis that you can install a FAN.I would install 2 FANS one to blow and one to suck(Sh1t it sound dirty).
  
 BTW i butchered my LD 1+ awhile back.


----------



## TrollDragon

bbmiller said:


> Could somebody post a picture of the power supply transformer I think there are two possible things I can think of being the power transformer in a little dot IV amplifier, but I am not sure which is the power transformer.


 
  
 The power transformer in the Little Dot is a torodial that sits under the square cover on top.

 http://www.hammondmfg.com/1182.htm
  
 The biggest concern that you should have about leaving the Little Dot amplifier on 24/7 is the possibility of it burning your house down if a failure might occur. Tube amps should never be left unattended as that is just asking for trouble.
  
 I also have a really hard time believing that leaving an amplifier on 24/7 really makes *that* *much* difference in the sound, so much that you would risk the safety of your family.


----------



## TrollDragon

Also blowing fans on the case to cool it down is a false sense of security as the components on the board are still getting just as hot, but the case is cooler to the touch now...
  
 Running the LD with the face plate or back plate removed causes the amplifier to hum very badly, so much that it is unusable, why do people have such a hard time running a product within it designed specifications?
  
 The quest for better sound?  If the C3g's were *THAT* amazingly incredible, then why are they not used in any commercial amplifiers, from Cary Audio, Eddie Current, Woo, Manley, Mcintosh, Prima Luna etc? And I don't mean one offs that have used the tube in it's design.


----------



## bbmiller

trolldragon said:


> bbmiller said:
> 
> 
> > Could somebody post a picture of the power supply transformer I think there are two possible things I can think of being the power transformer in a little dot IV amplifier, but I am not sure which is the power transformer.
> ...


 
  


trolldragon said:


> Also blowing fans on the case to cool it down is a false sense of security as the components on the board are still getting just as hot, but the case is cooler to the touch now...
> 
> Running the LD with the face plate or back plate removed causes the amplifier to hum very badly, so much that it is unusable, why do people have such a hard time running a product within it designed specifications?
> 
> The quest for better sound?  If the C3g's were *THAT* amazingly incredible, then why are they not used in any commercial amplifiers, from Cary Audio, Eddie Current, Woo, Manley, Mcintosh, Prima Luna etc? And I don't mean one offs that have used the tube in it's design.


 
 Thanks very much trolldragon that link you gave me on the  torodial transformer should lead me to the exact model of transformer I should need if it should ever need replacing. I do not want to remove the transformer cover right at this moment since I do not want to turn off my amplifier right now I haven't listened to it yet today and the 24/7 thing is making a tremendous difference in the sound quality to my ears.
  
 I am live a loan bachelor so I will not be burning up my family should I cause a fire just possibly myself. My house is also fully detached.
  
 I am thinking my thoughts as I expressed in a post above of attaching aluminum fin heatsinks to that transformer cover might indeed work now if that is the most critical part of the little dot amplifier to need extra cooling to make 24/7 possible. Perhaps if I shoot that black transformer cover with a heat gun temperature probe before and after 6 to 8 hours I can see if I am's succeeding in keeping that transformer cool.
  
 I look followed to your instructions on removing the printed circuit board if necessary, but there is definitely definitely no rush.


----------



## Uncle AL

Hi bb,

If there are comments contrary to the idea of leaving the LD on 24/7, it is out of compassion, for you and safety. That being said, continual operation of electronic equipment that is not engineered for that purpose, unduly stresses components, including transformers, as was pointed out. 

A fellow engineer I worked with on a design project, was also a technical expert, investigating cause of electrical fires. There was a demonstration (national fire investigators) of failure of power supplies and surge suppressors following continual operation, resulting in virtually explosive combustion and incineration of everything within 2-3 feet. While the design of a tube amplifier differs from a regulated power supply or surge suppressor, those devices are designed for continual 24/7 operation, yet over time, the stress on components may lead to catastrophic failure and potential unpredictable combustion. Even less so, is a tube amplifier equipped to take the strain of continual operation. For safety, my colleague recommended replacing surge suppressors every 2-3 years. Since tube amplifiers are less equipped for continual operation than a surge suppressor, it might be wise to consider replacing your amplifier after roughly 12-18 months, for safety-sake. Understandably, the cost of doing so would counterbalance any perceived gains. Tubes would likely need to be replaced twice during that time period, adding maybe another 50% to the cost of maintaining 24/7 operation.

More importantly though, is the concern I and all of your fellow head-fiers have for your welfare and safety.


----------



## gibosi

trolldragon said:


> The quest for better sound?  If the C3g's were *THAT* amazingly incredible, then why are they not used in any commercial amplifiers, from Cary Audio, Eddie Current, Woo, Manley, Mcintosh, Prima Luna etc? And I don't mean one offs that have used the tube in it's design.


 
  
 Can't say why these particular manufacturers don't...  It is my understanding that Yamamoto is the company most responsible for "discovering" these tubes (actually the C3m, which is the 20V version):
  
 http://www2.117.ne.jp/~y-s/index-e.html
  
 They manufacture a number of different amps using this tube:
  
 http://www2.117.ne.jp/~y-s/HA-03-news-E.html
  
 http://www2.117.ne.jp/~y-s/A-014-News-E.html
  
 http://www2.117.ne.jp/~y-s/A-010-e.html
  
 http://www2.117.ne.jp/~y-s/A-08S-101D-104D-amp-e.html
  
 http://www2.117.ne.jp/~y-s/A-06-3-News-2-E.html


----------



## TrollDragon

Haha leave it to gibosi to find a manufacturer...
  
 Yamamoto makes amazing amplifiers and he likes to use odd tubes.
 http://www2.117.ne.jp/~y-s/A-08S-205D-amp-e.html


----------



## hypnos1

trolldragon said:


> The quest for better sound?  If the C3g's were *THAT* amazingly incredible, then why are they not used in any commercial amplifiers, from Cary Audio, Eddie Current, Woo, Manley, Mcintosh, Prima Luna etc? And I don't mean one offs that have used the tube in it's design.


 
  
 Hi TD...a very good question. I would suspect there are quite a few reasons - eg...awareness of tube; availability; cost (probably not re high-end, of course); preference for tubes with wide variety/local manufacture; prejudice(!), etc. etc. It would be interesting to know how many of them have actually even considered experimenting with them in the first place...
  
 I suppose we'll never really know for sure...(Mind you Glenn of Glenn amps, at least, rates them highly. And as gibosi says, Yamamoto). All we ourselves can go by is how they stack up against the MANY different (and fairly top-tier) tubes we have been experimenting with for a long time now...and at the end of the day THAT'S ALL THAT COUNTS, NO?


----------



## Oskari

hypnos1 said:


> I would suspect there are quite a few reasons - eg...awareness of tube; availability; cost (probably not re high-end, of course); preference for tubes with wide variety/local manufacture; prejudice(!), etc. etc.


 
  
 Yep. Only a small-scale boutique manufacturer can use long-out-of-production parts (unless they hold extensive stock).
  

http://www.colotube.ch/en/vacuum-tube-amplifiers/preamplifier-se/


----------



## Acapella11

Just browsed through the last two pages and what comes to my mind is that this thread always reads well and is good to come back to. 
Meanwhile the C3GS are burning in and surely, they are an amazing pair of driver tubes.


----------



## hypnos1

acapella11 said:


> Just browsed through the last two pages and what comes to my mind is that this thread always reads well and is good to come back to.
> Meanwhile the C3GS are burning in and surely, they are an amazing pair of driver tubes.


 
  
 You're certainly right there, A11...some good while ago I was supposed to be having a sojourn from things head-fi and devoting more time to other commitments...garden, fish etc (not to mention the good lady!). And yet here I still am, pestering people more than ever...must be true addiction, lol! 
	

	
	
		
		

		
		
	


	



  
 I am SO glad you also are finding the C3g a quite exceptional tube...


----------



## superdux

so i tried some Raytheon 5687 as Power tubes today using some Hytron 6AK5 as drivers and the first thing i realized was definatly more (authorativ) punch in the bass. Maybe even a bit too much, i'm not sure. Spatial layering was obvious on Sgt.Peppers Lonely Heart Clubs Band from the Beatles.Also there were fine noises to be recognized, like some breathing on the Beatles album i didn't hear before.
 I found the Hytrons a bit boring with stock power tubes but the Raytheons made them shine. I used my HD580 to listen.
 I can't wait to test with C3G soon, as my new adapter arrived from china and the POST tubes will probabbly arrive end of next week for those interested in some C3G(S) please leave me a message.
  
 EDIT: all C3GS are sadly gone now, so there'll still be enough C3G to grab and if someones on a tight budget i will have around 6 C3G tubes used for 5€ each. The other tubes are 10€. Postage would be 3.45€ International.


----------



## mab1376

hypnos1 said:


> Hi TD...a very good question. I would suspect there are quite a few reasons - eg...awareness of tube; availability; cost (probably not re high-end, of course); preference for tubes with wide variety/local manufacture; prejudice(!), etc. etc. It would be interesting to know how many of them have actually even considered experimenting with them in the first place...
> 
> I suppose we'll never really know for sure...(Mind you Glenn of Glenn amps, at least, rates them highly. And as gibosi says, Yamamoto). All we ourselves can go by is how they stack up against the MANY different (and fairly top-tier) tubes we have been experimenting with for a long time now...and at the end of the day THAT'S ALL THAT COUNTS, NO?


 
  
 Lets email a few of the manufacturers and see their views on the c3g.
  
 my guess is it is an extremely microphonic tube, so much so moving my mouse on the same desk can create a very slight ringing only audible with no music playing.


----------



## gibosi

mab1376 said:


> my guess is it is an extremely microphonic tube, so much so moving my mouse on the same desk can create a very slight ringing only audible with no music playing.


 
  
 I have two pairs, C3g-s and C3g, and neither are microphonic....


----------



## mab1376

gibosi said:


> I have two pairs, C3g-s and C3g, and neither are microphonic....


 
  
 I removed the shield on mine, and didn't glue the ring back on, just pressed it into the adapter. works perfect if there's no vibrations on the desk, and even if there is, i only hear it when theres no music.
  
 Also i only audibly hear the microphonics with my very sensitive T70's.


----------



## hypnos1

mab1376 said:


> Lets email a few of the manufacturers and see their views on the c3g.
> 
> my guess is it is an extremely microphonic tube, so much so moving my mouse on the same desk can create a very slight ringing only audible with no music playing.


 
  
 Hi mab.
  
 I must admit I did once notice a _slight_ touch of microphonics (never _extreme_), but I've a feeling it was more down to the power tubes at the time...must do some further examination. But certainly nothing that had me in the slightest worried, lol!. It sounds like yours is nothing too intrusive - hopefully!


----------



## TrollDragon

A light tap on the amp body or tube will tell you very quickly.


----------



## Acapella11

I have to knock my C3GS shield or LD directly to cause a ringing. Knocking onto the table directly around the amp causes only the tiniest of a noise.


----------



## mab1376

acapella11 said:


> I have to knock my C3GS shield or LD directly to cause a ringing. Knocking onto the table directly around the amp causes only the tiniest of a noise.


 
  
 This is true for me with the HD650


----------



## SomeoneWhoIsntMe

On the subject of noise/feedback in these amps... with my stock LD 1+ and ultrasone DJ1-Pro cans I can hear a faint popping or ticking noise in the right channel, which steadily repeats quickly, maybe at a rate of about 6-8Hz? The sound remains present with the input unplugged and does not change it's amplitude regardless of the volume setting on the amp, it persists even with the volume down all the way. Is this noise from the power supply leaking through?


----------



## gibosi

someonewhoisntme said:


> On the subject of noise/feedback in these amps... with my stock LD 1+ and ultrasone DJ1-Pro cans I can hear a faint popping or ticking noise in the right channel, which steadily repeats quickly, maybe at a rate of about 6-8Hz? The sound remains present with the input unplugged and does not change it's amplitude regardless of the volume setting on the amp, it persists even with the volume down all the way. Is this noise from the power supply leaking through?


 
  
 Have you tried a different pair of tubes? Or have you tried swapping tubes? That is, left to right and right to left?


----------



## SomeoneWhoIsntMe

gibosi said:


> Have you tried a different pair of tubes? Or have you tried swapping tubes? That is, left to right and right to left?



 


Thanks, I swapped the tubes L/R and the noise seems to have decreased noticeably. I've got a muses02 and a pair of voshkod tubes on the way anyhow, so I'll just forget about noise from the stock tubes for now!


----------



## TrollDragon

_"Welcome back my friends to the show that never ends, we're so glad you could attend. Come inside! Come inside!"_​  
LD MKIV Circuit Board Removal​  
 Use masking tape to label wires and a sheet of paper to mark down the solder locations of the wires you have to unsolder to remove the circuit board,
  
*1.* Unplug cables & remove tubes

*2.* Loosen volume knob set screw and remove knob. Remove nut from volume control shaft.
  
*3.* Remove the two faceplate screws and slide the faceplate forward.
  
*4.* Unsolder the headphone jack wires from either the jack itself or the circuit board and remove the faceplate.
*4a.* Look inside at the way the heater wires are positioned in the chassis (Two white twisted pairs and Two green twisted pairs) so you can try to position them the same way when you reassemble the amplifier.
  
*5.* Unsolder the Line Out and Line In wires from the circuit board.
  
*6.* Remove the two back plate screws. The back plate will not pull free and needs to be swung away from the chassis by pulling on the RCA side, sliding the Line In/Out wires out of the case and rotating the back plate away towards the power plug side.
  
*7.* Remove the 4 black screws on top of the chassis at each corner of the gold colour tube guard plate.
  
*8.* The circuit board will be loose, lower the board and work it forward till the driver tube sockets clear the front of the chassis, unsolder the left and right driver tube heater wires from pins 3 & 4 of each socket.
  
*9.* Work the circuit board out the back of the chassis so you can unsolder the DC Heater elevation wire from the back corner and the transformer secondary wires from the power section.
  
*10.* Working the circuit board out a little further till you can unsolder the output tube heater wires from pins 4 & 5 of each socket.
  
*11.* Work the circuit board out through the back of the chassis by maneuvering the standoffs around the transformer wires.
  
*12*. Now the circuit board is free, hopefully you marked all the wires and where they went on the circuit board. 
	

	
	
		
		

		
			




  
_**Reverse the steps above for reassembly, if you take your time at the disassembly, take lots of notes if required and *__*pay attention to how it is assembled from the factory. You shouldn't have any trouble putting it back the same way.**_
  
  
 When putting the amplifier back together there are a few things you should be aware of:
  
 Line up the led with the faceplate hole before you screw down the faceplate.
  
 The little black screw on top in the front right position is the screw that connects the circuit board ground to the chassis. If this screw is loose or you didn't put it back in, there will be a massive hum.
  
 If the volume control shaft nut is too tight the volume control will bind up or be stiff around the 70-80% volume mark. If this happens just loosen the shaft nut a bit till you have free travel from 0 to 100.
  
 The amplifier will work with either the back or front plates removed but there will be a massive hum till they are both screwed on. These screws just screw into little channels in the chassis which can strip very easily, If this happens then just take a pair of needle nose pliers and squeeze the channel that the screws go into a little bit to bring both sides a little closer together.
  
 The reason I use the word work instead of slide for taking the circuit board from the chassis is that it really has to be worked with the brass standoffs around the transformer wires to get it in or out.
  
 If you do manage to get the circuit board out and put it back in again without any hassle and have it still working, then a little celebration of a job well done is in order.

 The LD MK III should have a similar type of take apart except that the headphone jack is soldered onto the circuit board instead of being attached to the front plate.
  
 Good Luck!


----------



## mordy

Very impressive TD! But why? What secret mod/upgrade did you do?


----------



## i luvmusic 2

trolldragon said:


> _"Welcome back my friends to the show that never ends, we're so glad you could attend. Come inside! Come inside!"_​
> LD MKIV Circuit Board Removal​
> Use masking tape to label wires and a sheet of paper to mark down the solder locations of the wires you have to unsolder
> to remove the circuit board,
> ...


 
 Another job well done by Mr.TD,Thank You!
  
 Now you give me  idea on how to Butcher my MK III..........


----------



## TrollDragon

mordy said:


> Very impressive TD! But why? What secret mod/upgrade did you do?


 
 Hi mordy,
  
 bbmiller asked for instructions a while back.


----------



## MIKELAP

trolldragon said:


> _"Welcome back my friends to the show that never ends, we're so glad you could attend. Come inside! Come inside!"_​
> LD MKIV Circuit Board Removal​
> Use masking tape to label wires and a sheet of paper to mark down the solder locations of the wires you have to unsolder to remove the circuit board,
> 
> ...


 
 Now i know why i wont take it apart lol.


----------



## bbmiller

> TrollDragon
> The amplifier will work with either the back or front plates removed but there will be a massive hum till they are both screwed on. These screws just screw into little channels in the chassis which can strip very easily, If this happens then just take a pair of needle nose pliers and squeeze the channel that the screws go into a little bit to bring both sides a little closer together.


 
 Thanks troll Dragon!
 In regard to the noise created by leaving the back or front plate off. I am wondering in the same regard if one was to create some small holes on the side of your case between the two tubes geographically where the cathode resistors should be positioned if that could create noise too. Were holes to create noise one could use duct tape and aluminum foil to cover it up better shielded that it was before.
  
I have checked all parts of the little dot IV MK case with a multimeter and it all seems made of insulated material with no shielding. I even sled the front plate slightly to get in there with my multimeter and the case does not seem coded with shielding. Well if you observed noise by leaving the front of backplate off you heard it if you heard it! But do you have any physics type reasoning for this observation?
  
 Incidentally I now have the transformer cover off and I'm blowing a cooling  fan right on that transformer and it seems to stay cool 100% of the time.


----------



## TrollDragon

bbmiller said:


> Thanks troll Dragon!
> In regard to the noise created by leaving the back or front plate off. I am wondering in the same regard if one was to create some small holes on the side of your case between the two tubes geographically where the cathode resistors should be positioned if that could create noise too. Were holes to create noise one could use duct tape and aluminum foil to cover it up better shielded that it was before.
> 
> I have checked all parts of the little dot IV MK case with a multimeter and it all seems made of insulated material with no shielding. I even sled the front plate slightly to get in there with my multimeter and the case does not seem coded with shielding. Well if you observed noise by leaving the front of backplate off you heard it if you heard it! But do you have any physics type reasoning for this observation?
> Incidentally I now have the transformer cover off and I'm blowing a cooling  fan right on that transformer and it seems to stay cool 100% of the time.


 
 I don't really know about drilling holes in the side of the case.
  
 As to the chassis not measuring with a multimeter, it is Anodized Aluminum and the the anodic layer is non-conductive.


----------



## mordy

Hi superdux,
  
 I read with interest that you used the 5687 as power tubes. What kind of adapter do you use? Can you comment on any comparison of the sound of the 5687 vs 6SN7 or 6SL7 (or other tubes) as power tubes?
  
 Presently, I am using the 5687 as driver tube with very good results. I am waiting to compare it to the C3g tubes - hope to have the adapters soon. The 5687 has an extremely detailed mid bass, and as you mentioned, I often hear new things in old familiar recordings.


----------



## sgbwill2

Hi Mordy, I too will be receiving GE 5687 5 star's and using them as power tubes so I will let you know how they sound when i get them. I wouldve thought that they would draw up too much to be used as drivers as each tube draws up 0.9A in 6.3V. I purchased http://www.ebay.co.uk/itm/321472393335?_trksid=p2059210.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT as adapters to convert 12.6V to 6.3V


----------



## superdux

hi mordy,
  
 i am rather impressed by the 5687 tubes, but i can't compare to 6SL7 cos these are the only different tubes i tried until now. I'll report back how they sound with the C3G as soon as my package arrives next week.
 I can tell you bass has been leaner\better and details are more "scetched"(in german "durchgezeichnet") out and there's some spatial imaging i haven't experienced before. I don't know if it's the combination with the driver tubes but i will update soon.
 Listening to Joni Mitchell "Blue" was a real pleasure as the music had a nice imaging on my setup.I was a bit surprised to hear the better details to stock power tubes.
 These are the adapters i used including extenders.
  
 Ebay article No. 290977041297
  
 These are the socket savers\extenders
  
 Ebay article No. 160622385954


----------



## gibosi

sgbwill2 said:


> Hi Mordy, I too will be receiving GE 5687 5 star's and using them as power tubes so I will let you know how they sound when i get them. I wouldve thought that they would draw up too much to be used as drivers as each tube draws up 0.9A in 6.3V. I purchased http://www.ebay.co.uk/itm/321472393335?_trksid=p2059210.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT as adapters to convert 12.6V to 6.3V


 
  
 Yes, they draw too much amperage to be used as a driver without an external heater PS. But with an external heater PS, I routinely run 5687's, 6SN7's and other higher current tubes as drivers. And in fact, I am listening to a nice Sylvania 5687WA as I write this.


----------



## mordy

Hi superdux,
  
 Perhaps the English hi fi word you are looking for is "etched", meaning that the details stand out clearly.
  
 I would like to hear from somebody who tried both 5687, 6SN7/6SL7 and 6AS7/6080 as power tubes before I shell out the money on the adapters. Anyone out there?
  
 I already have the 9pin extenders - must be a lot of people tinkering, because they sold some 300 sets.....


----------



## superdux

Yes mordy, that's what i meant!


----------



## Uncle AL

gibosi said:


> Yes, they draw too much amperage to be used as a driver without an external heater PS. But with an external heater PS, I routinely run 5687's, 6SN7's and other higher current tubes as drivers. And in fact, I am listening to a nice Sylvania 5687WA as I write this.



How's the audio quality / soundstage with this set-up?


----------



## mordy

Hi Uncle Al,
  
 I have been using the 5687 as driver for a while now,  and I have some eight different tubes from Tung Sol, Sylvania and GE. At this point it is my favorite driver tube. I am using two Sylvania 6080WA as power tubes with an external power supply.
  
 These tubes can be run at 6.3V or 12.6V depending on how they are wired. I am running these tubes on 12.6V because when I tried 6SN7 and 12SN7 which are essentially the same tube but made for different voltages, I felt that the bass was more tight with the 12V tubes. This is my personal opinion and may not have any basis in fact and be dependent on other factors than voltage. I may be all wrong on this, and the voltage may not make any difference with the 5687 tubes, but at this time I am running the 5687 with an external power supply and a voltage regulator set at 12.6V.
  
 All the tubes sound good with the exception of a bronze plate Tung Sol which has a soft bass- perhaps this one isn't in as good a shape as the others because one channel is weaker.
  
 All of the tubes are from the 60's, and cost me between $4 - 8 including shipping. (All bought as used, but it could be that some were new since burn in changed the sound.)
  
 What I like about this tube is that it excels in everything; great and exquisitely detailed mid bass, low bass is very strong, great mid range and beautiful highs. Wide 3D sound stage, pinpoint imaging etc etc.
  
 This tube has great synergy with the 6080s  and reveals new details and distinct layers in familiar recordings. It is possible to concentrate on one instrument and follow it, whereas with other tubes this distinction may be blurred or drowned out.
  
 Waiting to try the Cg3S tubes to compare.....Should have everything ready soon.
  
 Happy tube rolling!
  
 PS: The 5687 has a nice glow as well
 This tube is a GE. Above the factory code 188-5 it says the letters LV - anybody knows what it means?

  
 Night view of the boiler room:


----------



## MIKELAP

Trying to find out if this pair of Sylvanias 6SN7 GTB is a pair of bad boys .Thanks


----------



## mordy

Hi Mikelap,
  
 Seems that Sylvania Bad Boys were only manufactured in 1951 and 1952.
  
 “Later GT versions were in a medium glass envelope with a green label and blackplates with bottom getter, sometimes called the “Bad Boy” 6SN7, and are sought after for their excellent sonics. The Bad Boy tubes are virtually identical to the military VT-231 from the early 1950s and are currently a less expensive alternative, but this could change as the Bad Boy fad catches on! A side note about Bad Boys, there were versions with 2 rivet holes in each plate, and versions with 3 holes. Both types sound identical. Don’t fall for the bogus story that only the 3 rivet hole types are the true “Bad Boys”! You will miss out on some great sound from the 2 hole type, since the 3 hole versions are more difficult to find, more expensive elsewhere, and don’t sound any different! I suspect the “3-hole only” story got started by my competition to justify charging a higher price for these tubes!”
 I have to agree with that. I compared two Sylvanias which were identical except one had 2 holes and the other 3 holes. And the difference??? The only difference is the year of production. 
	

	
	
		
		

		
			





 2 hole version of from 1951, 3 hole version is from 1952. The sound identical. Both have bottom foil getter."
  
 The 6SN7GTB was introduced in 1954 so according to the above, the tubes pictured are not the the Bad Boy type. What year are those Canadian tubes from?


----------



## gibosi

uncle al said:


> How's the audio quality / soundstage with this set-up?


 
  
 With my ears and gear, the Sylvania is exceptional. 
  
 Regarding the 5687s, I have Sylvania, Tung-Sol, Raytheon, RCA and GE. However, I have spent the most time with the Tung-Sol (1952 and 1956) and the Sylvania (1961 and 1963).
  
 Both the TS and Syl are exceptionally transparent with great micro detail. For me the major differences are the midrange on the TS is a bit more forward and there is less decay and reverberation. And in my opinion, both of these attributes affect the soundstage. To my way of thinking, decay and reverberation allow one to hear sound reflecting off the walls, which conveys the feeling of being in a physical performance space as opposed to a highly damped recording studio. With my ears and gear, it is easier for me to imagine I am in a performance space with the Syl. And I find the midrange on the Sylvanias to be a bit recessed compared to the TS. As a result, the TS, with a more forward midrange, puts the vocals inside my head, and the other instruments seem quite close, creating a rather flat, 2-D soundstage. The Sylvania, with the more recessed midrange, puts the vocals slightly in front of my head, which in turn seems to push the other instruments even further off into the distance, creating a nice and deep 3-D soundstage.
  
 But of course, everyone's ears and gear are different.... My ears have many years of wear and tear, I have an LD1+ with a MUSES02 opamp and I use Senn HD700's. Perhaps with a warmer system, the TS might hit the sweet spot? I don't know....


----------



## Uncle AL

gibosi said:


> With my ears and gear, the Sylvania is exceptional.
> 
> Regarding the 5687s, I have Sylvania, Tung-Sol, Raytheon, RCA and GE. However, I have spent the most time with the Tung-Sol (1952 and 1956) and the Sylvania (1961 and 1963).
> 
> ...



+1... Thanks for your detailed impression and especially the comparison of Tungsol vs. Sylvania tubes. I am trying to recall if adapters are required for 5687? I have an LD MK IV SE, and have tried plug-n-play tube rolling, so far including 6HM5 / 6H30Pi. Looking forward to transitioning into adapting tubes and stretching boundaries beyond the usual.. into the extrodinary!


----------



## gibosi

uncle al said:


> +1... Thanks for your detailed impression and especially the comparison of Tungsol vs. Sylvania tubes. I am trying to recall if adapters are required for 5687? I have an LD MK IV SE, and have tried plug-n-play tube rolling, so far including 6HM5 / 6H30Pi. Looking forward to transitioning into adapting tubes and stretching boundaries beyond the usual.. into the extrodinary!


 
  
 If you wish to use a pair as power tubes, all you need is a couple pin-adapters. These will work:
  
 http://www.ebay.com/itm/1x-5687-to-6N6-6N1-6N2-6N6-6N11-ECC88-E88CC-Vacuum-tube-adapter-socket-converter-/321472393335
  
 However, if you wish to use one as a driver, you will need to cobble some sort of adapter to connect one 9-pin socket to your two 7-pin LD driver sockets plus an external PS providing at least 1.5A. I would suggest wiring the 9-pin socket for a ECC88, so you would need only one of the above adapters.


----------



## bbmiller

trolldragon said:


> bbmiller said:
> 
> 
> > Thanks troll Dragon!
> ...


 
 OK a thread I started called "[size=24.7999992370605px]*Can venting holes be added to a tube amp case without breaking shielding?*[/size][size=12.8000001907349px]" Is[/size] making me feel encouraged to think that adding venting holes to your little dot case can be a good way to reduce any heat build upe[size=12.8000001907349px] [/size][size=12.8000001907349px]insid[/size] the case. The trouble is I've been running tests, which I do not know are valid or not, drilling into a discarded desktop PC power supply which I perceive as being aluminum. These drilling test make it seem extremely tough to drill into anodized aluminum if that's what I am drilling into when I run these tests. Using a Trammel high speed rotary tool and the high speed rotary tool only (because just a plain drill doesn't work) I can get not bad drilling speed, but it takes one bit per hole. 
  
 I was also thinking of cutting out a hole, say in the bottom of the little dot case, to install a fan. Cutting a PC power supply case(assuming it is indeed comparable material to a little dot case) I see you can melt away one dribble cutting wheel per inch and a half of cutting. Well those cutting wheels come in 20 packs which might make doing that cheap enough. You can then install an aluminum mesh to restore shielding, but you might have to sacrifice drill bits at one drillbit per hole if you were to attach your aluminum mesh with sheet metal screws.
  
 So this is a very long and drawn out way to ask you all how hard of aluminum do you think the anodized aluminum in the little dot case is. Have any of you drilled into one or cut into one and can relate to my long drawn out story above?


----------



## Oskari

mordy said:


> This tube is a GE. Above the factory code 188-5 it says the letters LV - anybody knows what it means?


 
  
 That's the warranty date code. See the following link.
  

http://www.antiqueradios.com/forums/viewtopic.php?f=19&t=218841


----------



## hypnos1

Hi folks.
  
 After that disastrous episode with my rogue C3g adapter, I'm glad to say it wasn't down to some stupid mistake in the wire routing or the like - they now work a treat! 
	

	
	
		
		

		
		
	


	




.
  
 So now I can feel secure in posting the tutorial on how to make 'em...but I have to admit my particular method calls for a certain degree of confidence with a soldering iron/pliers/hacksaw etc., plus a good deal of patience and care. If you can muster these requirements and follow instructions pretty well to the letter (unless you are more experienced than I, of course, and can modify to your preference!), you should end up with something FAR superior to those Chinese things...and derive a great deal of satisfaction into the bargain, lol!
  
 If you think you may want to give it a try, I would _strongly_ recommend you get 2 or 3 of superdux's cheap used tubes for testing, in addition to your main ones...just in case of possible disasters (like mine!!).
  
 Then, of course, Mikelap should hopefully be posting a tutorial also, which may well be a more straightforward method...
  
 Anyway, for now this is how they (can) look...full post another day - need a bit of a rest, I'm afraid! 
	

	
	
		
		

		
		
	


	



  

  
 One thing I have to say is it would appear that what I have suspected for some time may well be true - ie the more there is between the tube and the amp the more is the likelihood of slight sound degradation, depending on the quality of other elements in the signal path, of course. I say this because I compared 2 C3gSs + adapters (that have the top sockets in situ, of course) to my original ones where I soldered the wires direct to the tube's pins. The difference was unnoticeable with a pair of 7N7s as powers (which are high-quality Sylvania 6SN7s, basically), but as soon as the GEC CV2523s (6AS7G) went in it _was_ noticeable.
  
 Now it could just be down to the need for the new adapters to burn in, but one at least had a good few hours on it. But some of the differences were not in areas where burn-in usually improves things. So I still think there may be something in  it, lol!...Or I could be totally wrong! 
	

	
	
		
		

		
		
	


	




.  However, those who also need to add an extender in addition to the adapter I am quite sure _are_ losing out slightly...again, depending on the power tubes used. Probably, it's only because these GECs are quite phenomenal in their detail resolution and clarity...which further reinforces the capabilities of the C3g(S, in particular) - they just keep improving in line with the power tubes used (whoever said the powers are not so important in the scheme of things?!...).


----------



## i luvmusic 2

hypnos1 said:


> Hi folks.
> 
> After that disastrous episode with my rogue C3g adapter, I'm glad to say it wasn't down to some stupid mistake in the wire routing or the like - they now work a treat!
> 
> ...


 
 What type of materials did you used as a feller inside the tube?Thanks!


----------



## Acapella11

mab1376 said:


> Lets email a few of the manufacturers and see their views on the c3g.
> 
> my guess is it is an extremely microphonic tube, so much so moving my mouse on the same desk can create a very slight ringing only audible with no music playing.


 
  
 Hi mab1376, just a possibility and what I experienced recently: I heard high pitched noises dropping into the sound. I first thought it was my monitor until I realized it was my mouse. What I did as a trial was to move my USB-cable, connecting the DAC, to a lonesome front slot and those interferences were gone.
 Besides this, I am still a weak crackling noise, which is only noticeable between tracks, when carefully listening. I don't think the PC generates a very clean USB-signal also.


----------



## hypnos1

i luvmusic 2 said:


> What type of materials did you used as a feller inside the tube?Thanks!


 
  
 Hi ilm2.
  
 I use 2-part epoxy resin as filler/glue, which can be rather expensive - here in the UK the main brand names are Araldite and Evo-Stik. But I have just found some in one of our 'thrift' shops (Poundland) at a fraction of the price - clear liquids in plunger-like tubes...NOT the sort that caused my recent disaster! Perhaps you have similar shops near you?
  
 The reason I use this is because it pours nicely into all the tight spaces (as long as you work fast if using the 'rapid' version!) and seals everything nice and firmly. I tried hot glue, but mine would not stay liquid long enough to flow into all said tight places...So that's _my_ preference, anyway...
	

	
	
		
		

		
		
	


	




.


----------



## i luvmusic 2

hypnos1 said:


> i luvmusic 2 said:
> 
> 
> > What type of materials did you used as a feller inside the tube?Thanks!
> ...


 
 I thought about using a Lepage PL Premium construction adhesive.THANKS!


----------



## hypnos1

i luvmusic 2 said:


> I thought about using a Lepage PL Premium construction adhesive.THANKS!


 
  
 From what I can see, I don't think anything like this product is going to flow properly to fill all the 'nooks and crannies', lol!


----------



## i luvmusic 2

hypnos1 said:


> i luvmusic 2 said:
> 
> 
> > I thought about using a Lepage PL Premium construction adhesive.THANKS!
> ...


 
 You are right because it's a thicker type adhesive.


----------



## Acapella11

Has anyone compared a 5687 as power tube with a 6N6P-IR. Is this a step up?


----------



## MIKELAP

Heres a look at future adapters for c3g tubes 2nd picture is total lenght and third  picture is the lenght sticking over the LD rings  which is about 11/2¨ inches .pin straightner will be hot glued over socket at bottom as always to  strenghten the pins .sockets maybe will be JB welded to casing and shrink wrap will be over entire casing and sockets ,should be sturdy and should last  a long time.


----------



## mordy

Hi Oskari,
  
 Thanks for the link to GE date codes - looks like my tube is from August 1966. There is also a reference to deciphering the GE etched dot codes, but I could not find anything on the Internet. Would you have any link?
  
 Perhaps you have a link to the Tung Sol codes as well - another mystery....
  
 Thanks very much for the above information about GE.


----------



## TrollDragon

mikelap said:


>


 
 Now that is going to be one excellent C3g to 6Ж1П adapter!


----------



## Oskari

mordy said:


> There is also a reference to deciphering the GE etched dot codes, but I could not find anything on the Internet. Would you have any link?
> 
> Perhaps you have a link to the Tung Sol codes as well - another mystery....


 
  
 Only negative answers to give this time. Sorry.


----------



## mab1376

acapella11 said:


> Hi mab1376, just a possibility and what I experienced recently: I heard high pitched noises dropping into the sound. I first thought it was my monitor until I realized it was my mouse. What I did as a trial was to move my USB-cable, connecting the DAC, to a lonesome front slot and those interferences were gone.
> Besides this, I am still a weak crackling noise, which is only noticeable between tracks, when carefully listening. I don't think the PC generates a very clean USB-signal also.


 
  
 No it doesn't at all, look into the Schiit Wyrd "USB Decrapifier".
  
 I use Coax from my sound card to my Bifrost, so i don't have any USB weirdness.
  
 My iBasso D6 sometimes can turn to white noise if the USB get out of sync.


----------



## mojorisin35

mikelap said:


> Heres a look at future adapters for c3g tubes 2nd picture is total lenght and third  picture is the lenght sticking over the LD rings  which is about 11/2¨ inches .pin straightner will be hot glued over socket at bottom as always to  strenghten the pins .sockets maybe will be JB welded to casing and shrink wrap will be over entire casing and sockets ,should be sturdy and should last  a long time.


 

 WOW amazing JOB I want a set!  the 6DJ8 adapter I purchased of mike is a thing of beauty...Just thinking out loud making 2 pairs is not that much harder...eh!


----------



## MIKELAP

mojorisin35 said:


> WOW amazing JOB I want a set!  the 6DJ8 adapter I purchased of mike is a thing of beauty...Just thinking out loud making 2 pairs is not that much harder...eh!


 
 Thanks  .Not harder just more parts and more time lol.


----------



## superdux

Here's a pic of my amp with the 5687 tubes:


  
 and good news the C3G tubes have arrived and i still have a few C3G NOS and used here for anyone interested. NOS would be 10€ each, used 5€ each. Postage worldwide is 3.45€, registered mail 2.05€ extra and paypal fees around 1~2€.


----------



## hypnos1

OK folks... bearing in mind my previous statements, here goes (my) C3g adapter-making guide...please note the change mentioned at the end...
  
 I'm sorry if it may appear somewhat long-winded but trust me, there are a few things that can trip you up and so need extra care (hence the unreliability of those Chinese ones!) - _I_ had to learn some of them the hard way..._you_ don't have to, hopefully!
  
 First, some of the main tools you'll need :
 Plus vise, of course...and preferably some kind of 'helping hands' gizmo.   
 Note the pliers are LONG-NOSED, and small watch repair tools are invaluable.
                                                                                                                                                                                                                                                                                                                                                                                                                                 
 Now to the parts :
  
 Pic#1...2 pcs cut aluminium (preferably, as non-conductive)         Pic#2...  2 LOCTAL sockets - I suggest you buy 4 or more, just
  
 tubing - internal diameter 26.5mm approx. I painted mine...    in case! They're not too expensive from the Far East...
 Length about 25mm

  
 Pic#3...Stiff plastic sheet (I used an old food container!) to       Pic#4...Cut lengths of wire that form the pins - shown here
                          act as pin wire guide/holder.                              bare wire (high-quality silver coated copper, or 925 Sterling
                                                                                                     silver if you want to 'push the boat out'!). These are part-covered
                                                                                                     with Teflon (PTFE) tubing - 2mm internal diameter. If your
                                                                                                     amp/extender sockets are well-used and getting a loose fit,
                                                                                                    I suggest 1.2mm wire. If still tight, 1mm should be OK. You may
                                                                                                    prefer to use plastic coated wire (but good quality, solid).
  
                                                                                                    For later reference, these are numbered 1 to 7 from the left,
                                                                                                    and *AT THE LD END!*
                                                                                                
 Construction :
  
 To remove the socket from its holder, I find it easiest to place in the vise (vice!) and lever up the lugs first with a small watch-repair screwdriver, then finish with a slightly larger one...but be as gentle as possible, the ceramic is surprisingly brittle! :
  

  
 Cut narrow strips of masking tape and wrap around the socket's edge, then mark the pin numbers on it - the numbers can be seen (very faintly!) on the underside, or just remember they run LEFT TO RIGHT CLOCKWISE, #1 starting to the left from the central indent - AS YOU SEE IT, looking down at the underside of the socket. It pays to check, check and check again all through the construction to make sure you don't invert those numbers!
  
 If you have removed the tube from its canister and haven't glued the metal base back on, you will want to use just the base for the rest of the process and I suggest you secure down the socket's pin holders with more tape, as they can protrude up during construction - you can just see an example of this in the above photo. For others, the contained tube will be inserted and will then reduce this tendency.
  
 Ref. pic#2. The socket's centre metal guide has an extension for a ground connection that we don't use, so needs to be removed (as seen in photo)...just hold in long-nosed pliers and bend back and forth, it soon snaps off...Also, as the tube is held EXTREMELY tightly by the guide, I personally open it up a bit by using the pliers as shown below - but the choice is yours! If you do, be very careful once again not to use too much force. The narrow masking tape (with the pin numbers marked on it) around the socket's edge gives some protection.
  

  
                         
  
 Now with the whole tube (or just metal base, as below) inserted into the socket, we need to insulate the centre exposed metal parts. I find using the removable fixing 'putty' (ours called 'BLU-TAK') the simplest method, as it is also good for sealing the small holes around the pin connectors (to prevent seepage of the epoxy resin later) :
  

  
 Then, I like to prime the connector tabs with solder.
  
 Now we need to prepare the wires as per pic#4...to make life a bit easier, I have shown the rough shapes they can be bent to, remembering the numbers relate to the LD end, 1 to 7, left to right (of course I should have arranged them as at the C3g end, since that's where they're soldered - a senior moment, lol! So PLEASE keep referring to the equivalent C3g number when positioning for solder).
 The wire lengths should be roughly as : (LD) pins #3,4,5&6 - 35mm;  #1 - 32mm; #2 - 38mm; #7 - 39mm. Plus you need a short piece to connect *C3g pin tabs 2 & 7* inside the socket.
  
 Oh dear...am running out of time and nowhere near finished, so I'll have to part post this and continue after dinner - sorry! (If you haven't already given up anyway! 
	

	
	
		
		

		
			





...(Haven't found how to just save work here, yet...). So BFN...
  
 Right, that's dinner out of the way so it's back to work.
  
 So with wires at the ready - those with conventional wire will of course need to bare the bent (solder) ends, and strip to leave about 10mm covering beyond these ends (the photos will give you a rough idea) - I find it useful to also prime the bent ends with a little solder.
  
 Now it's time to solder the wires to the socket tabs...and this is where those 'helping hands' flexible grips come in REAL handy ('scuse the pun!). Remembering to CAREFULLY convert the wires' LD pin numbers to the C3g equivalent, solder them so as they all SPREAD OUTWARDS, as per the photo - the idea being that when you push the soldered tabs forward they will be close to the required new position (with some manipulation needed later, that is!). And remember the short 2-7 C3g internal connecting wire will join with that to the LD at C3g #2  :
  
 The pin routing is as follows  :
  
     LD    C3g
  
      1   -   6
      2   -   5
      3   -   8
      4   -   1
      5   -   3
      6   -   4
      7   -   2
               7 connected to 2 inside socket
  
  

  
 If you haven't already, I now suggest you cover the tube canister also (not shown above) with masking tape, for protection from any resin yet to come!
  
 Next, it's time to push forward (and over where necessary) the soldered tabs, making sure the joins are really secure - the pushing and pulling will soon show up any that aren't!
 By studying carefully just where they need to go to match the LD pin positions, hopefully you won't find it too hard to manipulate the wires to roughly where needed, and the long-nosed pliers will be vital in the bending needed to finally get the positions just right.
  
 A bit more of an idea can be got from holding the LD pin holder (more info on it below) above the socket as a guide  :
  

  
 nb...don't forget to mark the correct corresponding numbers on the underside of the plastic, because when you look at the underneath for positioning it's easy to get confused due to the 'inversion' factor! *KEEP CHECKING* the C3g numbers are going to the correct LD target numbers...you can't be too careful...
  
 Better late than never, a look at these pin holder/guides - ref. pic#3. Although other items can be used - like cut pieces of circuit board or 7-pin straighteners, if you can find them - because of the need for gaps to pour in the resin, I have found it fairly easy to cut to shape pieces of thin but stiff plastic (like that used in food containers).
 As in the photo, this can be done by drawing a circle to the same diameter as the inside of the case, marking the pin positions in the middle (for example by dabbing some ink/paint to the ends of an old tube and applying, or making a paper stencil of the same size and pushing the pins through to make the required holes for stencilling onto the plastic), then drawing the triangle to just clear the holes. Now drill the holes (2mm drill bit for 1.2mm wire, and perhaps a 1.5mm bit for 1mm wire, you can always increase the size if necessary) - keeping as vertical as possible. Finish by cutting it out (carefully, please, if using a Stanley knife!), and trim to fit inside the case.
  
 (Will post this last section before it freezes on me again, and continue after...)
  
 Right now...where was I?...can't blame the page for freezing on me (again!)...wouldn't blame _you_ either...but perhaps if you digest bits at a time and mull over what's involved for a few days, you might just feel like giving it a go...
	

	
	
		
		

		
		
	


	



  
 Anyway, by now the pin wires are hopefully just about in position enough to work through the holes in the guide - cutting them to equal length (not too short, yet!) and using a pair of tweezers should help, plus a good dose of patience. Be *ABSOLUTELY SURE* you have aligned the pins correctly through the holes...check, check and check again. At this point, when you push the guide down to its final resting place, just below the top of the case which is slid over and onto the socket, you will see just how near the middle you've managed to position everything (the case may just need a forceful push to sit flush on the socket - the degree will indicate how far out you may be). This will give you an indication of where you may need to do some last minute bending at the lower end of the wires to correct things, and with the case removed you will also see how true the wires are vertically...adjust to the best vertical you can manage  :
  

  
 As you can see, I had some more adjusting to do!!
  
  
 With all adjustments finished, you *MUST *make sure there is no metal to metal contact ANYWHERE...check especially where the soldered tabs are bent over the covered central dome - if necessary pack with more of the Blu-Tak (or equivalent). And where wires have to cross. Make sure also the casing is well clear of the bent tabs when placed onto the socket - if in any doubt at all, form a ring of insulating tape around them. While at it, check also the 'putty' sealing the gaps at the base of the pin connectors/tabs - it's probably come loose after all the manipulating...
  
 It would be wise to check with a meter that you have continuity from socket to pins - this would also act as final confirmation you have routed the pin wires correctly. Failing this, at least make sure all the solder joints are still secure.
  
  
 Slide the case back over, and while holding it flush to the socket wrap tightly with masking tape, making sure it seals well at the join.
  
 Now it's time to prepare for filling with epoxy resin...
  
      Oh dear, time has run against me again...afraid I shall have to finish this tomorrow.
  
 Good night all (if you're still awake, that is!)...as I said earlier, please digest all this in bite-sized pieces...
  
 OK...let's get this massive missive done and dusted, lol...
  
 I suggest that if only the tube's metal base was used, as opposed to the whole thing, you check the top of the socket and make sure none of the pin connectors has been pushed up and standing proud - just push 'em back down if they have before filling with resin (you might also want to check the base is flush up to the socket - if not, remove and replace the masking tape while holding the base in hard...you don't want too much of a gap here, as the tube's pins are not very long).
  
 And so, with the plastic pin guide/holder just below the case edge (and the pins hopefully looking fairly straight!), run some masking tape around them, flush with the case's edge   :
  

  
 You're almost there now, folks...give yourselves a pat on the back for having got this far(!), and get mixing that 2-part epoxy resin. I suggest that unless you're used to working fast with the 'rapid' version, you use the ordinary type that takes longer to cure...you'll just have to be a bit more patient, lol! I use this type of 'glue' because it flows nicely into all the tight spaces inside the case and seals everything like almost nothing else can - and, like, PERMANENTLY once cured!...which is why it really is a good idea to do that checking with a multimeter before this irreversible stage (although you _can_ always cut the case and smash the innards with a heavy hammer if worse comes to worse!!).
 I find my tubes of resin - about 24 grams combined - enough to do the job, and I suggest you mix it in a small, shallow (but not _too_ shallow), square or rectangular plastic container that will allow you to be fairly precise in pouring through the gaps formed by the pin guide (perhaps with the help of a small spatula or old screwdriver, for example). Filling to just about the top of the case should cover the guide and the small area of pins between it and the tape (hence the need to place the protecting tape FLUSH with the case edge) , thereby securely finalising the position of the pins.
  
 When finally set, remove the ring of tape, making sure no resin has crept up the pins - if so, just remove with a Stanley knife. Then trim the pins to about 8mm (better a little more than less) and smooth the ends with a small file - preferably to a slight, rounded point, to aid insertion...(I find my wire cutter sometimes pushes out the edges - if so, make sure you remove the protrusions with extra filing).
 All this will probably push the pins slightly out of position, so check with another pin guide; up against the base of an old tube; a 7-pin socket or straightener if you have one, and readjust if necessary.
 If you have been working with bare hands all the while, there's likely to be a load of grease on those pins, so I suggest cleaning them with something like isopropyl alcohol, or white spirit followed by a damp cloth.
  
 Now all that remains is to remove the masking tape -  while breathing a great sigh of relief! -  and plug the darned thing in...I suggest removing any extender and then plug the adapter into it, just in case a certain amount of 'wiggling' and careful use of force is needed - especially if the larger 1.2mm wire is used. Not only will this be easier away from the amp, but will reduce the strain on the amp's socket - I feel those sockets (_and_ PCB) are not mounted all that strongly!. Those with the bare tube now need to be VERY careful when inserting into the adapter - not only re correct alignment into the metal base, but because it can be an extremely tight fit, and may need careful, but quite forceful, working in of the pins...so *TAKE EXTRA CARE!*
  
 Hopefully all is well as you power up  - and they actually WORK?!...Whereupon you will, no doubt, wear the biggest smile (almost!) of your life...
	

	
	
		
		

		
		
	


	




... As I mentioned previously, all the better if you test first with a cheap used tube - _just_ in case.
  
 So there we have it...a project I don't doubt has put some (if not many!) of you off the whole idea...BUT...if you do have the basic skills necessary, it won't seem so daunting if you take your time and go over all that I have covered here a good few times, and allow yourself plenty of time to get all the necessary bits (and tools) together, and start making the various components slowly, one at a time - don't try to rush things...you may well become frustrated and disheartened. If necessary practice some of the procedures a few times to gain confidence - and hone your soldering skills as best you can. The end result will be MORE than worth it, when you can enjoy the magic of the C3g tube...not to mention the immense satisfaction from achieving such a goal.
  
 I wish you all the very best in the event you do bite the bullet...at the very least, this has shown just what is involved in making these things, lol! 
	

	
	
		
		

		
		
	


	




.
  
 (Perhaps MIKELAP's offering will be more straightforward than mine...we wait with eager anticipation!).
  
 CHEERS!
  
 ps...By the way, if you didn't catch the finished article in a previous post, this is how they can look...:
  

  
 Update on construction...
  
 To save having to make those triangular pin guide/holders, Mikelap's use of B7G pin straighteners/protectors should be much easier, if you can get hold of them...viz :


----------



## Acapella11

Wow hypnos1, very detailed guide for the C3g adapter, good job! This will make this tube available to everyone if they are sufficiently into diy.


----------



## stvn758

Is the Headphone Amp on the Audiolab MDAC Solid State - I can switch between that and my Little Dot MK3 and compare with the tube sound?  I just got my new Matched Voskhod Gold pins Gold grid 6ZH1P-EV 6AK5 EF95 403B 5654 6J1 1975 NIB tubes, not the magical transformation I was hoping for from the stock ones, seemed quite harsh at first.
  
 Been going through my music collection, I suppose the good news is they do sound different so there must be some that sound better. I'll give these a while to run in and let my ears get used to them, see if they improve. I have AKG 712's and the aforementioned DAC. Any hints for my next purchase would be gratefully received, the previous recommendation was actually cheaper  so it seems I don't have to break the bank to tube roll. All those numbers after the tubes though, make finding the ones recommended here a nightmare.


----------



## TrollDragon

stvn758 said:


> Is the Headphone Amp on the Audiolab MDAC Solid State - I can switch between that and my Little Dot MK3 and compare with the tube sound?  I just got my new Matched Voskhod Gold pins Gold grid 6ZH1P-EV 6AK5 EF95 403B 5654 6J1 1975 NIB tubes, not the magical transformation I was hoping for from the stock ones, seemed quite harsh at first.
> 
> Been going through my music collection, I suppose the good news is they do sound different so there must be some that sound better. I'll give these a while to run in and let my ears get used to them, see if they improve. I have AKG 712's and the aforementioned DAC. Any hints for my next purchase would be gratefully received, the previous recommendation was actually cheaper  so it seems I don't have to break the bank to tube roll. All those numbers after the tubes though, make finding the ones recommended here a nightmare.


 
 Wow.. NICE Dac!
  
 It is solid state and you could switch between it and the LD to compare sound... Get a SPL/Sound Meter application for your smart phone so you can match the output of the two amplifiers. Play a single frequency tone (1KHz for example) into the DAC and measure the output level of it's headphone amplifier with the app. Then switch the output over to the LD and adjust it to the same level. Then when you play your music both amps will be at the same level, you can't match volume by ear and as we all know, a little louder always seems to sound better.


----------



## gibosi

stvn758 said:


> Been going through my music collection, I suppose the good news is they do sound different so there must be some that sound better. I'll give these a while to run in and let my ears get used to them, see if they improve. I have AKG 712's and the aforementioned DAC. Any hints for my next purchase would be gratefully received, the previous recommendation was actually cheaper  so it seems I don't have to break the bank to tube roll. All those numbers after the tubes though, make finding the ones recommended here a nightmare.


 
  
 Many think the 6HM5 made in Yugoslavia are superb, and fortunately, they are plentiful and cheap:
  
 http://www.ebay.com/itm/6HM5-EC900-EI-Yugoslavia-NOS-matched-pair-Little-Dot-Amp-FREE-SHIPPING-WW-/251691711374?
  
  
 http://www.ebay.com/itm/EI-6HM5-EC900-6HA5-6HQ5-former-Yugoslavia-MATCHED-PAIR-TUBE-NOS-/400771715218?
  
  
 http://www.ebay.com/itm/6HM5-6HA5-EC900-export-quality-audio-triode-tube-NOS-FREE-SHIPPING-/300879467071?
  
 Set your LD for EF95 tubes, plug them in and play.


----------



## Uncle AL

Quick question-- Has anyone noticed decreased amplifier output when using 6HM5 driver tubes? Amp volume previously was set to 40 and now requires upping volume to 92 for same listening level. Power tubes in both circumstances were same, 6H30PIs. Previous driver tubes, M8100s


----------



## mordy

Hi stvn 758,
  
 It is important to know that the Voskhod 6ZH1P-EV require an unusually long break in period before the harshness goes away - 110-120 hours. Patience....


----------



## TrollDragon

uncle al said:


> Quick question-- Has anyone noticed decreased amplifier output when using 6HM5 driver tubes? Amp volume previously was set to 40 and now requires upping volume to 92 for same listening level. Power tubes in both circumstances were same, 6H30PIs. Previous driver tubes, M8100s


 

 I run my 6HM5's at 35 for the T50RP's Gain 5X on the Mk IV. With every tube I have rolled I have never run the amp past 12 o'clock on the volume control.
  
 What gain are you running on the amp? They come default from the factory set to 3, give 5 a try.


----------



## stvn758

gibosi said:


> Many think the 6HM5 made in Yugoslavia are superb, and fortunately, they are plentiful and cheap:
> 
> http://www.ebay.com/itm/6HM5-EC900-EI-Yugoslavia-NOS-matched-pair-Little-Dot-Amp-FREE-SHIPPING-WW-/251691711374?
> 
> ...


 

 Thanks, will have a look. What happens if you don't set the Little Dot - does stuff explode, in case I forget which jumpers do what.


----------



## stvn758

trolldragon said:


> Wow.. NICE Dac!
> 
> It is solid state and you could switch between it and the LD to compare sound... Get a SPL/Sound Meter application for your smart phone so you can match the output of the two amplifiers. Play a single frequency tone (1KHz for example) into the DAC and measure the output level of it's headphone amplifier with the app. Then switch the output over to the LD and adjust it to the same level. Then when you play your music both amps will be at the same level, you can't match volume by ear and as we all know, a little louder always seems to sound better.


 
  
 Thanks.  I was reading up on them and someone listed instruments that sounded better on each style amp. I thought classical would sound better on a solid state amp and things like electric guitars would be more suited to old fashioned tubes. Especially as guitarists seem to favour them in their guitar amplifiers.


----------



## stvn758

mordy said:


> Hi stvn 758,
> 
> It is important to know that the Voskhod 6ZH1P-EV require an unusually long break in period before the harshness goes away - 110-120 hours. Patience....


 

 Am giving them a good go, what with electricity being so expensive and the power button being at the back of the amp and a pain to reach I find myself listening mostly with the inbuilt headphone amp, which is surprisingly good. Anyone know how much electricity these things use, it's getting quite chilly in my bedroom now winter is upon us so I could use my Little Dot as an amp and a heater - those lovely glowing valves can take the chill off.


----------



## gibosi

stvn758 said:


> Thanks, will have a look. What happens if you don't set the Little Dot - does stuff explode, in case I forget which jumpers do what.


 
  
 Well, I have never had one explode... lol...  Most of the time, either the tube sounds different, often worse, or in some cases, there is no sound at all.
  
 But you do have a manual? Yes? So forgetting isn't really a problem. Just look in the book.


----------



## stvn758

gibosi said:


> Well, I have never had one explode... lol...  Most of the time, either the tube sounds different, often worse, or in some cases, there is no sound at all.
> 
> But you do have a manual? Yes? So forgetting isn't really a problem. Just look in the book.


 
 I have it somewhere, have a downloaded copy as well. Just ordered a pair, can't go wrong at that price. Meanwhile I'll be giving these Voskhods a good run in, see what happens.


----------



## TrollDragon

stvn758 said:


> Am giving them a good go, what with electricity being so expensive and the power button being at the back of the amp and a pain to reach I find myself listening mostly with the inbuilt headphone amp, which is surprisingly good. Anyone know how much electricity these things use, it's getting quite chilly in my bedroom now winter is upon us so I could use my Little Dot as an amp and a heater - those lovely glowing valves can take the chill off.


 

 The MK IV draws 30W of power in the specifications on LD's site. If I ran it 6 hours it would draw .18 kWh which here in NS at 14¢ a kWh would cost me approximately 7¢ to run the amp.


----------



## stvn758

In the UK they are bleeding us dry for electricity, 10%+ it's just gone up. Bloodsuckers.


----------



## Uncle AL

trolldragon said:


> I run my 6HM5's at 35 for the T50RP's Gain 5X on the Mk IV. With every tube I have rolled I have never run the amp past 12 o'clock on the volume control.
> 
> What gain are you running on the amp? They come default from the factory set to 3, give 5 a try.



Thanks TrollDragon..

Source is an iPad Air, with volume at roughly 60%. Connected to the amplifier via Evergreen cable 3.5mm TRS to RCA inputs
Dip switches are set at ON-ON, with volume at 92 (4 O'Clock). Output to HD650s. This is the second amplifier. The first amplifier only required volume setting of 35.
Your assessment...?


----------



## SomeoneWhoIsntMe

Just got an email from a tube seller... he goofed and accidentally sent me (10) 6P1P-EV tubes, instead of the (4) 6J1P-EV tubes I ordered, so he's going to make it up to me by shipping me an additional four for a total of (8) 6J1P-EV's, and it'll probably be too expensive to ship the 6P1P's back to him in Russia. Any ideas What I can do with all these tubes? lol...


----------



## hypnos1

acapella11 said:


> Wow hypnos1, very detailed guide for the C3g adapter, good job! This will make this tube available to everyone if they are sufficiently into diy.


 
  
 Many thanks for those kind words A11...have finally completed the posting...I thought I was never going to get it finished - especially when the page froze my laptop a couple of times (each time after an hour or more's work!!). Thank Heavens I managed to (somehow) retrieve it, else I might just have given up on the whole thing!
  
 I only hope it doesn't appear _too _daunting a prospect to people  
	

	
	
		
		

		
			





...


----------



## TrollDragon

someonewhoisntme said:


> Just got an email from a tube seller... he goofed and accidentally sent me (10) 6P1P-EV tubes, instead of the (4) 6J1P-EV tubes I ordered, so he's going to make it up to me by shipping me an additional four for a total of (8) 6J1P-EV's, and it'll probably be too expensive to ship the 6P1P's back to him in Russia. Any ideas What I can do with all these tubes? lol...


 
 Send a pair to me!


----------



## superdux

great tutorial hypnos!Thx for your contribution to the Tube Rolling Community!


----------



## hypnos1

superdux said:


> great tutorial hypnos!Thx for your contribution to the Tube Rolling Community!


 
  
 Thanks superdux...and you certainly were very helpful in my resuming the project after the initial disastrous event!.. (No way could I have risked losing two more NOS C3GSs!!).
 Whether it encourages anyone to have a go is another matter, and remains to be seen, lol!...
	

	
	
		
		

		
			





.


----------



## TrollDragon

uncle al said:


> Thanks TrollDragon..
> 
> Source is an iPad Air, with volume at roughly 60%. Connected to the amplifier via Evergreen cable 3.5mm TRS to RCA inputs
> Dip switches are set at ON-ON, with volume at 92 (4 O'Clock). Output to HD650s. This is the second amplifier. The first amplifier only required volume setting of 35.
> Your assessment...?


 
 The second amplifier?
  
 I'd try a gain of 5 and see what you think, right now you have it set to 3.


----------



## MIKELAP

Tired of using extenders  on your LDMK3 time to break out the Dremel with cutting disk.Here's the result .


----------



## TrollDragon

mikelap said:


> Tired of using extenders  on your LDMK3 time to break out the Dremel with cutting disk.


 
  
 That's cheating...


----------



## MIKELAP

trolldragon said:


> That's cheating...


 
     Et voilà !


----------



## Acapella11

stvn758 said:


> Is the Headphone Amp on the Audiolab MDAC Solid State - I can switch between that and my Little Dot MK3 and compare with the tube sound?  I just got my new Matched Voskhod Gold pins Gold grid 6ZH1P-EV 6AK5 EF95 403B 5654 6J1 1975 NIB tubes, not the magical transformation I was hoping for from the stock ones, seemed quite harsh at first.
> 
> Been going through my music collection, I suppose the good news is they do sound different so there must be some that sound better. I'll give these a while to run in and let my ears get used to them, see if they improve. I have AKG 712's and the aforementioned DAC. Any hints for my next purchase would be gratefully received, the previous recommendation was actually cheaper  so it seems I don't have to break the bank to tube roll. All those numbers after the tubes though, make finding the ones recommended here a nightmare.


 
Hi stvn, I got the same dac and I am also in UK ☺ Besides, the dac amp ain't bad, but the LD MK III does or surely can anyway sound better. 
The Voskhods get softer during the very long burn in process. I would recommend to change the power tubes first thing to a pair of 6N6P-IR. Those are the best bargain for the money of the directly pin compatible ones, from my listening experience. Some othets hete on the thread have them also. Then, the Yugoslavian 6HM5 are very nice, transparent and dynamic. The stage is not very wide though. This is the standard tube suggested for an upgrade. Gentler with a wider stage are the heptodes. The tubes requiring adapters can achieve more SQ but require a bit more investment. 
Btw., which filter are you using? My favourite one is the Minimal Phase.


----------



## Acapella11

Good j





mikelap said:


> Et voilà !




Good cheating job! *thumbs up*


----------



## stvn758

acapella11 said:


> Hi stvn, I got the same dac and I am also in UK ☺ Besides, the dac amp ain't bad, but the LD MK III does or surely can anyway sound better.
> The Voskhods get softer during the very long burn in process. I would recommend to change the power tubes first thing to a pair of 6N6P-IR. Those are the best bargain for the money of the directly pin compatible ones, from my listening experience. Some othets hete on the thread have them also. Then, the Yugoslavian 6HM5 are very nice, transparent and dynamic. The stage is not very wide though. This is the standard tube suggested for an upgrade. Gentler with a wider stage are the heptodes. The tubes requiring adapters can achieve more SQ but require a bit more investment.
> Btw., which filter are you using? My favourite one is the Minimal Phase.


 
http://www.hi-fiworld.co.uk/index.php/cd-dvd-blu-ray/62-cd-reviews/642-audiolab-q-dac-filters-.html?start=1
  
 I did settle on Optimal Spectrum for the most part, after reading this article I experimented. I have used Minimum Phase as that is said to be the most analogue sounding one.


----------



## superdux

for any one interested: i'm selling a pair of C3G to 6AK5 adapters from the chinese seller i have spare for 45EURO including shipping worldwide. I have to admit they are rather fragile so you must not plug and unplug that much to keep them in order.


----------



## ToTje

Thx for the rep and inviting me to this thread, Mikelap! 
	

	
	
		
		

		
		
	


	




 I already had bookmarked this and browsed a bit through this thread a few times, but totally forgot about it.
  
 Anyway; Hello people! 
	

	
	
		
		

		
		
	


	



  


Spoiler: Introduction



Last september I bought an AKG K712 and Objective 2 + ODAC (actually E-DAC), but even though I was very impressed with the great level of detail and huge soundstage, I found this setup to be too bright sounding (although it does have a nice tight bass).
  
 After having tried out the Philips Fidelio X1 on the Objective amp, I decided to take things a few steps up to get the sound I really wanted and I bought an Audeze LCD-X and a Little Dot MK III with French NOS RTC 5654 tubes; my very first tube amp! 
	

	
	
		
		

		
		
	


	




 (Still using the ODAC though.) This really is a huge improvement to my "old" set! Much warmer sounding, more "oomph!" in the bass, the treble is less painful to my ears (although it still can be slightly sibilant at some times), far more detail in the lows and mids, and everything just sounds so much more realistic now! Just a pinch more sub-bass would have been lovely though. However, the tubes of course still need to burn in further. Seeing that the sound was horribly sibilant at first, I am sure the current sibilance will recede even further and perhaps the sub-bass will improve as well. (I am not a basshead at all and don't want to boost the current bass all the way; only a slight bump in the very lowest region so the sound gets closer to that of my active speakers.)
  
 I do miss the emphasis on some small details in the highs compared to my AKG with the Objective 2, and high female vocals sometimes lack their brightness, but am glad my ears don't hurt after an evening of listening to music anymore. This sound is far less fatiguing, and deep male vocals and most instruments in general also sound much more enjoyable now.
 My "old" set did seem to sound more spacious, appearing to have a much bigger soundstage. After getting a bit used to the new sound I learned how to interpret the soundstage on my new set. It's less explicit than on my other set, but it's still there. It does take a bit more concentration to fully notice it though.
  
 I am an absolute n00b with tubes and don't even know why trying out new tubes is called "rolling", and I hope I can get some new insights here. 
	

	
	
		
		

		
		
	


	




 
 I was told that grooved Gold-Platinum grid 6J1P-EV tubes would be an excellent upgrade for my amp, but perhaps there are even better options?
  
 My wishes may be a bit contradicting here and there. I'd like to improve the sub-bass and the soundstage, and smooth out the sibilance while also getting a bit more detail in the upper mids and treble. I'll check the first posts of this thread again to see if I can find something myself of which the description seems to be what I am looking for, but advices always are more than welcome! 
	

	
	
		
		

		
		
	


	




 Perhaps I should try out the Voshkod 6ZH1P-EV?
  
 Perhaps a different DAC also might help a bit?


----------



## hypnos1

totje said:


> Thx for the rep and inviting me to this thread, Mikelap!
> 
> 
> 
> ...


 
  
 Hi ToTje.
  
 Welcome.... If you're prepared to be patient and go back a fair way, you should find enough info to save you a lot of time - and MONEY! (please don't be too tempted by some of these so-called 'super' tubes that are direct plug and play replacements. The REAL, worthwhile improvements only came when we started modifying to use non stock-type tubes, like heptodes and triodes...you will find all the info you need - eventually! - by looking back, if you are interested in tackling some of these mods. (Even the earlier posts contain a lot of useful material on related subjects that will give you a bit more understanding of this fascinating area of hi-fi).
  
 As far as direct replacements for the front driver tubes go, some good while ago we found pretty well the best option was the tall-bottle 6HM5, which was also one of the cheapest! I found one of the best sources to be ebayer 'tachonz', who always accepted my offer of $5 a tube (with FREE shipping!)...an absolute steal 
	

	
	
		
		

		
		
	


	




. Gibosi posted a link (the 3rd one down) to his site on page 545.
  
 Then, if you can study what has been achieved regarding the POWER/output tubes, you will make even greater leaps in what your modest LD can achieve - to a level WAY beyond its fighting weight, lol!
  
 So take your time, digest things gradually and you may well be gobsmacked by the end results...WE certainly have been 
	

	
	
		
		

		
		
	


	




...
  
 Happy 'rolling', whatever you do...


----------



## ToTje

hypnos1 said:


> Hi ToTje.
> 
> Welcome.... If you're prepared to be patient and go back a fair way, you should find enough info to save you a lot of time - and MONEY! (please don't be too tempted by some of these so-called 'super' tubes that are direct plug and play replacements. The REAL, worthwhile improvements only came when we started modifying to use non stock-type tubes, like heptodes and triodes...you will find all the info you need - eventually! - by looking back, if you are interested in tackling some of these mods. (Even the earlier posts contain a lot of useful material on related subjects that will give you a bit more understanding of this fascinating area of hi-fi).
> 
> ...


 
 Thanks! 
	

	
	
		
		

		
		
	


	




 Yeah I'll browse a bit more thoroughly through this thread. I've only read about 10 pages or so, so far. I'll also look this tachonz up on eBay!


----------



## MIKELAP

totje said:


> Thanks!
> 
> 
> 
> ...


 
 Or this seller also   http://www.ebay.com/itm/6HM5-EC900-Lot-of-four-4-tubes-EI-Yugoslavia-NOS-free-shipping-/251611916081                                                                                                  ..............*THESE ARE THE CORRECT ONES NOT THE SHORT BOTTLES ..........*


----------



## ToTje

mikelap said:


> Or this seller also   http://www.ebay.com/itm/EC900-6HM5-Lot-of-four-4-tubes-EI-Yugoslavia-NOS-free-shipping-WW-/261599117610


 
 Even better, thx! 
	

	
	
		
		

		
		
	


	



 I'll try to find posts in this thread that explain the sound properties of these tubes and if the sound quality is very different than for instance the Voshkod 6ZH1P-EV.
 And power tubes also can make quite a difference?
 Got a lot of catching up to do!


----------



## hypnos1

totje said:


> Even better, thx!
> 
> 
> 
> ...


 
  
 Sorry to MIKELAP, but these look like the _short_-bottle version to me...which most found inferior to the _tall_-bottle. Please check...


----------



## MIKELAP

hypnos1 said:


> Sorry to MIKELAP, but these look like the _short_-bottle version to me...which most found inferior to the _tall_-bottle. Please check...


 
 Yup your right wrong ones these are the correct ones                                                                                                   http://www.ebay.com/itm/6HM5-EC900-Lot-of-four-4-tubes-EI-Yugoslavia-NOS-free-shipping-/251611916081


----------



## MIKELAP

Finished my C3G adapters today ,tutorial to follow shortly .Wish me luck want to write it once without deleting it by mistake lol.


----------



## i luvmusic 2

mikelap said:


> Finished my C3G adapters today ,tutorial to follow shortly .Wish me luck want to write it once without deleting it by mistake lol.


 
 So you jump into one of those EXPENSIVE TUBES,GOOD LUCK!!!!!!!


----------



## mordy

Hi ToTje,
  
_My wishes may be a bit contradicting here and there. I'd like to improve the sub-bass and the soundstage, and smooth out the sibilance while also getting a bit more detail in the upper mids and treble._
  
  
 Personally, I would recommend a 5687 tube as the answer to your "contradiction."


----------



## ToTje

mordy said:


> Hi ToTje,
> 
> _My wishes may be a bit contradicting here and there. I'd like to improve the sub-bass and the soundstage, and smooth out the sibilance while also getting a bit more detail in the upper mids and treble._
> 
> ...


 
 Thanks, all help is appreciated! 
	

	
	
		
		

		
		
	


	




 I see a lot of different types with that number though, and a HUGE price range.


----------



## hypnos1

mikelap said:


> Finished my C3G adapters today ,tutorial to follow shortly .Wish me luck want to write it once without deleting it by mistake lol.


 
  
 Well done, M...I hope to you-know-who _your_ pages don't freeze everything a good way through!...Nearly tore out what's left of my poor hair, lol!!  
	

	
	
		
		

		
		
	


	




.


----------



## gibosi

totje said:


> Thanks, all help is appreciated!
> 
> 
> 
> ...


 
  
 I am not sure how much you have read about how we use this tube in our LD's, so I think I should remind you that this tube can be used both as a replacement for your output tubes and as a driver. To use as output tubes, you will need to purchase a pair, along with adapters, as the 5687 has a pinout different than a 6N6P.
  
 If you wish to use the 5687 as a driver, you will need only one. However, as it is a double triode, you will need an adapter to allow you to connect the two triodes to the left and right driver sockets, and you will also need to use an external heater power supply providing at least 1.5 amps.
  
 And yes, some listings for these tube are quite high, especially if you want a pair. However, if you are patient you can find good deals. Mordy appears to be currently enamored with using the GE as a driver, and I favor the Sylvania, also as a driver. The RCA, Raytheon and Tung Sol are also worth trying if you can get them cheap. It does not appear that there were any other manufacturers, so if you see a Motorola, AEG, Siemens, or what have you, it was manufactured by one of the above and simply rebranded.
  
 Also, the 7044, 7119/E182CC and the 6900 have the same pinout and are also worth trying.


----------



## ToTje

gibosi said:


> I am not sure how much you have read about how we use this tube in our LD's, so I think I should remind you that this tube can be used both as a replacement for your output tubes and as a driver. To use as output tubes, you will need to purchase a pair, along with adapters, as the 5687 has a pinout different than a 6N6P.
> 
> If you wish to use the 5687 as a driver, you will need only one. However, as it is a double triode, you will need an adapter to allow you to connect the two triodes to the left and right driver sockets, and you will also need to use an external heater power supply providing at least 1.5 amps.
> 
> ...


 
 Wow! Plenty to look into, I see! Thx! 
	

	
	
		
		

		
		
	


	



 And about what I've read so far: I did browse through about 10 pages or so, but I think I should first really learn the basics about tube amps in general. I have read a simple explaination about how a tube works and a little bit about bias and such, so that's at least a start.


----------



## Acapella11

mordy said:


> Hi ToTje,
> 
> _My wishes may be a bit contradicting here and there. I'd like to improve the sub-bass and the soundstage, and smooth out the sibilance while also getting a bit more detail in the upper mids and treble._
> 
> ...


 

 Hi Mordy, is this more in favour of 5687 as a driver or a rather a power tube? Since you have  a pair of 6N6P-IRs, would you mind commenting on those as compared to the 5687?
  
 Welcome to the thread Totje.
	

	
	
		
		

		
		
	


	




 
  


mikelap said:


> Finished my C3G adapters today ,tutorial to follow shortly .Wish me luck want to write it once without deleting it by mistake lol.


 
  
 Curious about your sound impressions.


----------



## ToTje

Thanks Acapella! 
	

	
	
		
		

		
		
	


	



  
 Well in the mean time I've read this thread thoroughly: http://www.head-fi.org/t/119389/the-new-improved-tube-faq-for-newbies (Found it in chapter 5.3 at the first page here.)
  
 Now I think I have the basic knowledge to understand a bit what people are talking about in this thread here.


----------



## Johnnysound

totje said:


> Thanks Acapella!
> 
> 
> 
> ...


 
 Hi ToTje, and welcome ¡  
  
 This thread is certainly instructive,  and we can learn a lot from the more advanced users.   I was also a "newbie" in 2013, and  opted for a "step by step" approach,   experimenting with certain  "recomended" tubes in my LDMKIII,   and I must say that the advice from the people here was  excellent.   This thread is chronological, it starts as a guide for basic tube rolling  back in 2011 (¡) and then evolves steadily  into more advanced and radical options.   You need to search this thread as I did, but to save you some time,  I would suggest  a "Level 1" upgrade by   replacing the standard 6AK5 tubes (EF95 family) with  the Tung-Sol 6485 (EF92 family) or the very similar TS 6AH6WA tubes.  The Sylvania 6AH6WA is also excellent, and you can get these quite cheaply on Ebay.   The difference in SQ is inmediate,  the 6485, a pentode type,  is a more neutral and "quiet" tube, very detailed, but needs appropiate "burn in" to sound its best.  Take your time and look for NOS mil spec tubes.  
  
 The EF92 tubes require changing the internal jumpers in the LD, but a much practical solution is to "strap" the 2-7 pins in the socket with a little piece of wire. This is easy to do, and is explained in detail in this thread.   Curiously,   now the consensus here for the best  "plug and play" driver tube goes for the EI Yugo 6HM5 (tall bottle) which is a EF95 variant.  I am waiting for the mail to deliver mine, and is also a cheap tube.   Now you have two options to play with ¡   About upgrading the power tubes, see post 3007, page 201.  Frankly, I am perfectly happy with my  6N6P standard tubes.  Maybe I am lucky, because my LD came standard with 6N6P 1978 gold grid,  highly recommended in the review,  I do agree, great sounding tubes across the whole  sonic spectrum.    Have to compare with the 6N6PI-IR special version.  Summing up, lets stay in level 1, so  play with the drivers and do not touch the powers....for now


----------



## mordy

Hi A11,
  
 I have only used the 5687 as a driver tube so cannot comment on using them as power tubes. Some people in the past used an all 5687 set up (driver and power tubes), and I think Superdux just tried using the 5687 as power tubes with good results as well.
  
 I did try a number of 6N6P variants for power tubes, including the 6N6P-IR (but not the 6H30-DR). The consensus was that the best one is the so called "supertube" 6H30-DR which was incrementally better than the IR tube, but  not worth the considerable extra expense compared to the 6N6P-IR tube ($40/pair compared to $200/pair).
  
 However, inexpensive 6SN7 octal tubes used as power tubes were found to be better than the supertube in the LD, and at a fraction of the cost. The next step up in power tubes are the 6AS7/6080 tubes. The main difference between all these different power tubes is how impactful the bass is reproduced, as well as adding layers of detail and depth in the sound stage - the latter applying to the 6AS7/6080 tubes.
  
 There is a cliche that the power tubes only add some 15% of the sound compared to the driver tubes. Based on my personal experience they have a much greater impact, but only in synergy with the right driver tubes. With the right combination the power tubes have a great impact and change the entire sonic presentation. The difference, as an example, is between flat and soft, and full bodied and lively.
  
 A Little Dot owner may be very pleased with the 6HM5 as a driver, and the 6N6P-IR as power tubes, but once you switch to the 5687 (or C3g which I haven't tried yet -coming) and 6AS7/6080 as power tubes, there is no turning back.  There is simply more of everything; more bass, more treble, more clarity - everything is beautifully balanced and sounds right.
  
 As mentioned many times, all of these great tubes require external power supplies and/or adapters, but IMHO it is very much worth the trouble to make these modifications which elevate the Little Dot amps to a totally different level of performance.
  
 PS: How can I make statements about tubes that I did not audition personally? After having compared notes with members of this forum for several years you get an appreciation of the other person's taste and listening preferences and you come to a realization that their judgments are correct and can be relied upon.


----------



## Johnnysound

Just received today a small lot of  6AH6WA/6AU6 tubes and all are really interesting,  will take decent pictures soon, but in the meantime this is what I got:
  

  
 IEC Mullard 6AU6 , not NOS but tested very strong (no problem at $1.50 each),  and I really enjoyed how they sounded, very musical, very nice,  very special, with strong and deep bass, in fact deeper bass  than my reference Tung-Sols 6485.   A true gift at the price.   Now for the experts, are  marked "made in England" and it arouses suspicion, the Mullards normally say "made in Great Britain". I also learned that  latest production IEC Mullards (late 70s.) were in fact made in the U.S.  However, the tubes have etched codes as all Mullards have, top line 1022 652 and bottom line 2G5 || 199.  Deciphering this is not easy,  I have no idea of the date, but the G5 code and the parallel vertical lines indicate that these were made at the Loewe Opta plant by Valvo in Hamburg, Germany,  for Mullard.  Now that explains the "made in England" anomaly.  Not  made in England, but in Germany.  Interesting discovery,  just try to find a Valvo 6AU6, it will cost you perhaps 40 or 50 dollars each....if you can find one.  This is a very entertaining hobby, indeed.  
  

  
 NOS Tung-Sol USAF 6AH6WA,  1961. (3)  I understand that some friends here have similar   tubes, and liked them very much.  I have not tested them yet,  but at first glance  looks almost identical in its components to my reference TS 6485s, (which  are probably  mid sixties tubes), and  If  the 6485 is  an special version of the 6AH6,  then this one is certainly even more special.    Obviously, it  was  made to much higher specs than any civilian tube, and I can imagine it as part of the electronics of a B-52 bomber.  This is a super 6485,   with an inner (partial)  black coating I never saw before in small tubes,  only in overpiced military 6SN7/VT 231. For 5.30 dollars each, it sounds like a good investment.   My LDMKIII  will be then a live Cold War exhibition,  with American nuclear bomber tubes as drivers and Russian nuclear missile tubes as powers.   This is what I call international cooperation. 
  
  
  
   
  
 NOS Sylvania JAN-CHS 6AH6WA.    This is a real abuse, poor tubes ¡¡   Sorry for the "stock" photo, I promise a better one soon.  Anyway, I freed them from prison after 30 or 40 years in that plastic bag, and was inmediately impressed.   The tubes are brand new with perfect graphics,  and you can easily find 6AH6 Sylvanias, even JAN 6AH6WA Sylvanias, but all are transparent and none look even remotely like these,  with an almost full  black coated interior, in vertical bands around the tube, never saw anyhing like that.  I suspect this ones are the REAL military stuff, sold as surplus without boxes or anything.  Extremely rare.  One are inclined to think that the coating will mask the filament glow,  wrong,  they glow on top, just behind the chrome, and the blackes look really cooooool.  As you can imagine, after a careful cleaning and  "Pro Gold" treatment, I put them to work at once, They need to exercise after so many years (burn in)  but first impressions are really good,  no surprises;  quick, clean, detailed,  a serious contender against the Tung-Sols...


----------



## superdux

mordy said:


> Hi A11,
> 
> I have only used the 5687 as a driver tube so cannot comment on using them as power tubes. Some people in the past used an all 5687 set up (driver and power tubes), and I think Superdux just tried using the 5687 as power tubes with good results as well.


 
  
 The 5687 as power tubes seem a bit bass pronounced.They are also nicely detailed and give weaker sounding driver tubes new life.
  
 EDIT: i just switched to stock power tubes for the first 30 minutes of "Tommy" from The Who and changed back again and these are certainly an upgrade to stock tubes!Voices are more destinguishable, there's more spatial layering, some more bass and definately more detail.The sound is more crisper.
  
 Tested with C3G tubes as drivers.
  
 I will compare to 6SN7 next month when i have some money to buy a batch of tubes as the adapters are on their way from china.


----------



## Nic Rhodes

Made in Great Britain, British Made, Made in Holland and Foreign Made are all common on UK sold Mullards. Made in England however is more commonly used by MOV and Mazda etc but Mullard did also label some like this I think.


----------



## ToTje

johnnysound said:


> Hi ToTje, and welcome ¡
> 
> This thread is certainly instructive,  and we can learn a lot from the more advanced users.   I was also a "newbie" in 2013, and  opted for a "step by step" approach,   experimenting with certain  "recomended" tubes in my LDMKIII,   and I must say that the advice from the people here was  excellent.   This thread is chronological, it starts as a guide for basic tube rolling  back in 2011 (¡) and then evolves steadily  into more advanced and radical options.   You need to search this thread as I did, but to save you some time,  I would suggest  a "Level 1" upgrade by   replacing the standard 6AK5 tubes (EF95 family) with  the Tung-Sol 6485 (EF92 family) or the very similar TS 6AH6WA tubes.  The Sylvania 6AH6WA is also excellent, and you can get these quite cheaply on Ebay.   The difference in SQ is inmediate,  the 6485, a pentode type,  is a more neutral and "quiet" tube, very detailed, but needs appropiate "burn in" to sound its best.  Take your time and look for NOS mil spec tubes.
> 
> The EF92 tubes require changing the internal jumpers in the LD, but a much practical solution is to "strap" the 2-7 pins in the socket with a little piece of wire. This is easy to do, and is explained in detail in this thread.   Curiously,   now the consensus here for the best  "plug and play" driver tube goes for the EI Yugo 6HM5 (tall bottle) which is a EF95 variant.  I am waiting for the mail to deliver mine, and is also a cheap tube.   Now you have two options to play with ¡   About upgrading the power tubes, see post 3007, page 201.  Frankly, I am perfectly happy with my  6N6P standard tubes.  Maybe I am lucky, because my LD came standard with 6N6P 1978 gold grid,  highly recommended in the review,  I do agree, great sounding tubes across the whole  sonic spectrum.    Have to compare with the 6N6PI-IR special version.  Summing up, lets stay in level 1, so  play with the drivers and do not touch the powers....for now


 
 Wow, thanks for this extensive reply! 
	

	
	
		
		

		
			





 I'll surely look into it. At this moment I already have pentode tubes: French NOS RTC 5654RT tubes. I've seen them mentioned in this topic. I believe someone couldn't wait till they arrived and was very curious what they sounded like, and once he received them, they were a huge disappointment for him (if I remember correctly).
 I wish I could find more about the general characteristics of my current tubes and how they compare to for instance the ones you mention here (and others that are advised in this thread).
 If I want to try out different tubes, I prefer using some that have a very different sound, so I can decide what I like better. 
	

	
	
		
		

		
		
	


	




 With google I can't find anything bout how these sound.
 I don't really understand those families of tubes yet, but seeing that the number 5654 only appears in the EF95 family, I guess mine belong to that one. However, I read that there are huge differences in sound in that family, so I still don't know which ones these can be compared with. 
	

	
	
		
		

		
		
	


	




 I understand Mullard and RTC are the same, and it seems the 5654RT also is known as 6AK5.
  
 Looking at the characters on the power tubes in my LD, they appear to be russian (Plus the "CCCP" is a dead giveaway).
 I see:
 6H6П
 VI-73 (but the "-" is a pengaton, which I can't type)
 And then a load of characters that I really can't type.
 I'll check out post 3007, page 20 for the power tubes. 
  
 Edit: looks like the 6H6П is the standard 6H6P. My LD was upgraded with different tubes, but it seems that the power tubes are still the original ones then.


----------



## gibosi

johnnysound said:


> IEC Mullard 6AU6 , not NOS but tested very strong (no problem at $1.50 each),  and I really enjoyed how they sounded, very musical, very nice,  very special, with strong and deep bass, in fact deeper bass  than my reference Tung-Sols 6485.   A true gift at the price.   Now for the experts, are  marked "made in England" and it arouses suspicion, the Mullards normally say "made in Great Britain". I also learned that  latest production IEC Mullards (late 70s.) were in fact made in the U.S.  However, the tubes have etched codes as all Mullards have, top line 1022 652 and bottom line 2G5 || 199.  Deciphering this is not easy,  I have no idea of the date, but the G5 code and the parallel vertical lines indicate that these were made at the Loewe Opta plant by Valvo in Hamburg, Germany,  for Mullard.  Now that explains the "made in England" anomaly.  Not  made in England, but in Germany.  Interesting discovery,  just try to find a Valvo 6AU6, it will cost you perhaps 40 or 50 dollars each....if you can find one.  This is a very entertaining hobby, indeed.
> 
> .............................
> 
> NOS Sylvania JAN-CHS 6AH6WA..........


 
  
 I don't think your IEC Mullards were actually manufactured by Mullard. Below is the genuine article. Notice the two square holes and the round hole in the plates. Also, these tubes bear etched Mullard tube codes on the side, close to the base:
  
 Wd3 (Wd = EF94/6AU6, 3 = revision number)
 B2K3 (manufactured in Mullard's Blackburn factory in 1962)
  
 I am not sure where yours were manufactured. Rebranding was very common back in the day... Will take a look at my stash of 6AU6 and see if I can find a match.
  

  
 And the Sylvania 6AH6 is very interesting. I never came across a pair of Sylvanias, only GE and Tung-Sol, and again, I wonder if yours are rebrands....


----------



## Oskari

johnnysound said:


> IEC Mullard 6AU6 , not NOS but tested very strong (no problem at $1.50 each),  and I really enjoyed how they sounded, very musical, very nice,  very special, with strong and deep bass, in fact deeper bass  than my reference Tung-Sols 6485.   A true gift at the price.   Now for the experts, are  marked "made in England" and it arouses suspicion, the Mullards normally say "made in Great Britain". I also learned that  latest production IEC Mullards (late 70s.) were in fact made in the U.S.  However, the tubes have etched codes as all Mullards have, top line 1022 652 and bottom line 2G5 || 199.  Deciphering this is not easy,  I have no idea of the date, but the G5 code and the parallel vertical lines indicate that these were made at the Loewe Opta plant by Valvo in Hamburg, Germany,  for Mullard.  Now that explains the "made in England" anomaly.  Not  made in England, but in Germany.


 
  
 IEC was Mullard's US distributor. Their use of the brand was somewhat liberal to say the least, so you never know what you have – unless you do know.
  
 In this case, I believe, the answer is Brimars. There is a bit of a problem interpreting 2G5 as a Philips code because 2G indicates a type which doesn't match. Brimar codes are similar enough to cause confusion. In fact, the code looks like a Brimar code in the photo. 
  
 So, this time, the "made in England" is not a lie.


----------



## vic2vic

superdux said:


> I will compare to 6SN7 next month when i have some money to buy a batch of tubes as the adapters are on their way from china.


 
  
 Hi, do you have the link to the adapter (I found one on ebay but I'm not sure if it's the correct one) ?
 Anybody knows if the 6SN7 adapters works also for 6SL7 / 6N9S ? And would these tubes be comparable, soundwise, to the 6SN7 ?
  
 I found some 6N9S at home, form previous test on driver adapters, and maybe I can re-use them as power tubes.


----------



## superdux

hi vic, gibosi was so kind to look them up for me:
  
http://www.ebay.com/itm/1pc-6SN7-TO-6CG7-6FQ7-tube-adapter-for-you-amp-/191082280257?
  
http://www.ebay.com/itm/1x-6SN7-to-ECC88-Vacuum-tube-socket-adapter-socket-converter-/291181600224?
  
http://www.ebay.com/itm/two-Adapters-6SN7-6N1P-6N1-tubes-SUB-/250751485737?
  
 and another quote from gibosi:
  


> No they are definitely not the same. While they all have octal bases with the same pinout, they are otherwise very different. The 6SL7's heater draws 0.3A. The 6SN7's heater draws 0.6A. And the 6AS7's heaters draws 2.5A.
> 
> In terms of the LD, the 6SL7 does not need an external heater PS. The 6SN7 needs an external PS if used as a driver, but not as a power tube. And the 6AS7 needs an external PS if used as a driver or a power tube.


----------



## mordy

Hi vic2vic,
  
 The same adapter that works for 6SN7 will work just fine for 6SL7 and Russian equivalents. I found the 6SN7 having more heft than the 6SL7 types; the 6SL7 sounded more light weight and elegant.
  
 It could very well be a case of how to best pair these octals as power tubes with driver tubes for the best synergy.  Personally, I prefer the 6SN7 because of the better bass presentation. However, IMHO nothing beats the 6AS7/6080 tubes for real impact, detail, and slam in the bass,


----------



## mordy

I find it fascinating that we can have very similar impressions of a tube, in this case the 5687, even though our equipment is very different. The first quote is mine re using them as driver tubes:
  
_great and exquisitely detailed mid bass, low bass is very strong, great mid range and beautiful highs. Wide 3D sound stage, pinpoint imaging etc etc._
  
_reveals new details and distinct layers in familiar recordings._
  
  
_Here is Superdux impressions using them as power tubes:_
  
_The 5687 as power tubes seem a bit bass pronounced.They are also nicely detailed and give weaker sounding driver tubes new life._
  
_Voices are more distinguishable, there's more spatial layering, some more bass and definitely more detail.The sound is more crisper._
  
_*The next step is to pair them with the right power or driver tubes..*.._


----------



## Oskari

totje said:


> Looking at the characters on the power tubes in my LD, they appear to be russian (Plus the "CCCP" is a dead giveaway).
> I see:
> 6H6П
> VI-73 (but the "-" is a pengaton, which I can't type)


 
  
 If you are wondering, the pentagon means that the tubes were made by NEVZ-Soyuz in Novosibirsk. VI = month, 73 = year.


----------



## ToTje

oskari said:


> If you are wondering, the pentagon means that the tubes were made by NEVZ-Soyuz in Novosibirsk. VI = month, 73 = year.


 
 Ahhhh thanks! Yeah I already thought '73 must be the year.
  
 Anyway, I understand that these are quite ordinary, I'm checking up on the tips I got here for replacing the other tubes. Might as well replace these too!


----------



## MIKELAP

hypnos1 said:


> OK folks... bearing in mind my previous statements, here goes (my) C3g adapter-making guide.
> 
> I'm sorry if it may appear somewhat long-winded but trust me, there are a few things that can trip you up and so need extra care (hence the unreliability of those Chinese ones!) - _I_ had to learn some of them the hard way..._you_ don't have to, hopefully!
> 
> ...


 
 Nice job on the tutorial probably longer to do than the adapters themseves lol i know mine did .It wont be shorter thats for shure theres alot more than meets the eye ,also waiting for tubes to test adapters to see if they work first .again nice job.


----------



## Acapella11

[quote name="Johnnysound" url="/t/563884/little-dot-tube-amps-vacuum-tube-rolling-
 Frankly, I am perfectly happy with my  6N6P standard tubes.  Maybe I am lucky, because my LD came standard with 6N6P 1978 gold grid,  highly recommended in the review,  I do agree, great sounding tubes across the whole  sonic spectrum.    Have to compare with the 6N6PI-IR special version.  Summing up, lets stay in level 1, so  play with the drivers and do not touch the powers....for now  
[/quote]

Very nice summary indeed. However, the point of changing the power tubes has two reasons:
1. Just like Mordy, I believe the difference is greater than 15 %. This estimation comes from "old" times. 
2. When rolling your driver tubes you will match them to your power tubes, consciently or not and if you have better and also slightly differently sounding power, tubes you will fit maybe a different driver tube. Also, you might find that differences between driver tubes become more apparent with better power tubes. Now, since there are more driver than power tubes, it makes sense to set the base alright, if that makes sense. 




mordy said:


> Hi A11,
> 
> I have only used the 5687 as a driver tube so cannot comment on using them as power tubes. Some people in the past used an all 5687 set up (driver and power tubes), and I think Superdux just tried using the 5687 as power tubes with good results as well.
> 
> ...




Thanks Mordy, I agree with you in terms of all the tubes I have tried. For the rest, I have some rolling ahead of me. What I was getting at ultimately asling for the 5687: Could the 5687 be ranked on a similar level as the 6SN7?


----------



## gibosi

acapella11 said:


> Thanks Mordy, I agree with you in terms of all the tubes I have tried. For the rest, I have some rolling ahead of me. What I was getting at ultimately asling for the 5687: Could the 5687 be ranked on a similar level as the 6SN7?


 
  
 Used as a driver, I would say yes. I find the Sylvania 5687WA to be very similar to a Sylvania 6SN7W. As I see it, the primary advantage of the 6SN7 is the variety. To the best of my knowledge, only 5 companies manufactured the 5687, all American, whereas the 6SN7 was manufactured by these same companies, plus several more American and a number of British, European and Russian companies. Further, there is the fact that the 6SN7 is still being manufactured today, so you have about 70 years of tubes to choose from. The variety is enormous. On eBay there are more than 3000 listings for 6SN7 compared to less than 400 for the 5687. The world of the 6SN7 is a tube roller's heaven. lol


----------



## hypnos1

mikelap said:


> Nice job on the tutorial probably longer to do than the adapters themseves lol i know mine did .It wont be shorter thats for shure theres alot more than meets the eye ,also waiting for tubes to test adapters to see if they work first .again nice job.


 
  
 Thanks M...yep, quite a work-up to say the least! 
	

	
	
		
		

		
		
	


	




...look forward to seeing _your_ hard work...
  
 And I just hope you don't have _my_ bad luck at first blast-off, lol!
  
 Really looking forward also to your impressions of the C3g...don't forget they get even better up to 50+ hrs burn-in if NOS...
  
 ps. I like how you use those 'pin straighteners'...got some coming so I can see if there's enough gap for pouring my resin into the case - much easier than making own guide/holder!


----------



## MIKELAP

hypnos1 said:


> Thanks M...yep, quite a work-up to say the least!
> 
> 
> 
> ...


 
 You would not believe the problems i had .


----------



## hypnos1

mikelap said:


> You would not believe the problems i had .


 
  
 Oh yes I would!!


----------



## MIKELAP

hypnos1 said:


> Oh yes I would!!


 
 I still have to write it on here lol hope for the best as the saying goes .


----------



## MIKELAP

Oups


----------



## mordy

Hi G,
  
 As I remember, your Sylvania 6SN7W has a metal base. Those tubes are selling for well over $100 today. whereas the 5687 Sylvania can be found today for less than a quarter of that price ( and occasionally you can find them for $8 or less).
  
 I realize more and more the importance of synergy and matching re driver tubes and power tubes. It seems that each tube will influence the other in terms of the sound. It could be that a good power tube will bring out new higher levels of performance from a good driver tube. In general I found that a good driver tube will make for a good power tube, BUT, if it does not move enough current, the bass will be weak.  The question is if 0.9A is enough (5687) or you have to go to 6BX7 (1.5A), or maybe only 2.5A will do (6AS7/6080).


----------



## Oskari

gibosi said:


> To the best of my knowledge, only 5 companies manufactured the 5687, all American


 
  
 Gibosi, you can add CSF to your list. I just noticed yesterday that I have a single French 5687WA from Saint-Égrève. There is always an exception, isn't there?


----------



## gibosi

Yes, it seems that there is always at least one exception! lol 
  
 And now that I know that the CSF tube exists,I will keep an eye out for one.
  
 Cheers


----------



## gibosi

mordy said:


> As I remember, your Sylvania 6SN7W has a metal base. Those tubes are selling for well over $100 today. whereas the 5687 Sylvania can be found today for less than a quarter of that price ( and occasionally you can find them for $8 or less).


 
  
 I have seen three versions of the Sylvania 6SN7W, two tall bottles, one with a metal and the other with a black phenolic base, and one short bottle, with a black phenolic base. My avatar pic is the tall bottle with metal base. The metal bands have a tendency to break, but a simple twist tie is a perfectly adequate fix. lol. And because the base was broken, I got it cheap. However, I prefer the short bottle version which can often be found for around $35. But yes, the Sylvania 5687WA is very similar and even cheaper. Frankly, I am not sure I could tell them apart in a blind test....


----------



## Johnnysound

gibosi said:


> I don't think your IEC Mullards were actually manufactured by Mullard. Below is the genuine article. Notice the two square holes and the round hole in the plates. Also, these tubes bear etched Mullard tube codes on the side, close to the base:
> 
> Wd3 (Wd = EF94/6AU6, 3 = revision number)
> B2K3 (manufactured in Mullard's Blackburn factory in 1962)
> ...


 
  
  


oskari said:


> IEC was Mullard's US distributor. Their use of the brand was somewhat liberal to say the least, so you never know what you have – unless you do know.
> 
> In this case, I believe, the answer is Brimars. There is a bit of a problem interpreting 2G5 as a Philips code because 2G indicates a type which doesn't match. Brimar codes are similar enough to cause confusion. In fact, the code looks like a Brimar code in the photo.
> 
> So, this time, the "made in England" is not a lie.


 
 Hi G,  I agree with you, all UK Mullards 6AU6s have the two big square holes and the characteristic round hole, just like  the Valvos made for Mullard, and also some Brimars.  Mine have a smooth plate with small rectangular holes and a big "O" getter.  I suspected rebranded american tubes , (Sylvania, Raytheon) with similar plates, but discovered that most US 6AU6 tubes have square getters (¡)
 Then, Oskari is probably right, SOME (not all) 6AU6 Brimars fit, the plates are coincident with very faint vertical lines, difficult to see in the photo,  7  digit codes,  complete with the "Made in England" statement. Also,I said code 2G5||199, but it is difficult to read and it can easily be 2G5/1199, similar to the Brimars in the photo ¡¡   Now, Brimar also rebranded tubes, so the mystery continues... or not ? Maybe that "1199" means something... 
  

  
  
 Here is another pair of Brimars, very similar  to the Mullards, but "foreign", obviously rebranded russian or eastern Europe tubes, just look at the "UFO" getter


----------



## gibosi

johnnysound said:


> Hi G,  I agree with you, all UK Mullards 6AU6s have the two big square holes and the characteristic round hole, just like  the Valvos made for Mullard, and also some Brimars.  Mine have a smooth plate with small rectangular holes and a big "O" getter.  I suspected rebranded american tubes , (Sylvania, Raytheon) with similar plates, but discovered that most US 6AU6 tubes have square getters (¡)


 
  
 Generally speaking square getters and halo getters are primarily an indication of the date of manufacture. Tubes manufactured in the 1940's and through the 1950's tend to have square getters, be they American or European. Halo getters began to appear in the late 1950's and early 1960's. So the US 6AU6 you are seeing were likely manufactured in the 1950's. Later American tubes have halo getters. And there is one more possibility: Japanese manufacturers.
  
 For example:
  
 http://www.ebay.ie/itm/TWO-NOS-TOSHIBA-6AU6-EF94-VACUUM-PENTODE-AUDIO-TUBES-JAPAN-60s-FREE-SHIPPING-/181581145755?


----------



## Oskari

johnnysound said:


> Then, Oskari is probably right, SOME (not all) 6AU6 Brimars fit, the plates are coincident with very faint vertical lines, difficult to see in the photo,  7  digit codes,  complete with the "Made in England" statement. Also,I said code 2G5||199, but it is difficult to read and it can easily be 2G5/1199, similar to the Brimars in the photo ¡¡   Now, Brimar also rebranded tubes, so the mystery continues... or not ? Maybe that "1199" means something...


 
  
 199 (or 1199) indicates the type. Please see the following link.
  

http://myweb.tiscali.co.uk/g8hqp/audio/brimarcodes.html
  
 They are Brimars. There is no mystery. 
	

	
	
		
		

		
		
	


	



  


johnnysound said:


> Here is another pair of Brimars, very similar  to the Mullards, but "foreign", obviously rebranded russian or eastern Europe tubes, just look at the "UFO" getter


 
  
 Yes:
  


gibosi said:


> Six 6J4Ps (Russian equivalent of the 6AU6/EF94) arrived in today's mail:


----------



## Acapella11

mordy said:


> Hi G,
> 
> As I remember, your Sylvania 6SN7W has a metal base. Those tubes are selling for well over $100 today. whereas the 5687 Sylvania can be found today for less than a quarter of that price ( and occasionally you can find them for $8 or less).
> 
> I realize more and more the importance of synergy and matching re driver tubes and power tubes. It seems that each tube will influence the other in terms of the sound. It could be that a good power tube will bring out new higher levels of performance from a good driver tube. In general I found that a good driver tube will make for a good power tube, BUT, if it does not move enough current, the bass will be weak.  The question is if 0.9A is enough (5687) or you have to go to 6BX7 (1.5A), or maybe only 2.5A will do (6AS7/6080).


 
  
 +1 for the cheap 5687s, although I will probably start with some 6SN7s now
 +1 for driver and power tube matching


----------



## mordy

Hi,
  
 Today I finally got the adapters to listen to the Cg3 tubes. First impression is splendid - really great sounding tubes. Need more time to burn them in and analyze and compare to other tubes.
 However, I have a problem: There is much more hum than with the other tubes I am using.
  
 I am using the C3g tubes in adapters plugged into Vector adapters to clear the ring on the LD MKIII. The voltage regulator for the power tubes is grounded to the chassis of the MKIII. Any suggestion to minimize the hum?


----------



## MIKELAP

mordy said:


> Hi,
> 
> Today I finally got the adapters to listen to the Cg3 tubes. First impression is splendid - really great sounding tubes. Need more time to burn them in and analyze and compare to other tubes.
> However, I have a problem: There is much more hum than with the other tubes I am using.
> ...


 
 Should join the club soon  hopefully tubes will come in this week will see if any hum with my adapters fingers crossed


----------



## gibosi

mordy said:


> Today I finally got the adapters to listen to the Cg3 tubes. First impression is splendid - really great sounding tubes. Need more time to burn them in and analyze and compare to other tubes.
> However, I have a problem: There is much more hum than with the other tubes I am using.
> 
> I am using the C3g tubes in adapters plugged into Vector adapters to clear the ring on the LD MKIII. The voltage regulator for the power tubes is grounded to the chassis of the MKIII. Any suggestion to minimize the hum?


 
  
 Plugged into my LD1+ in the exact same way, C3g/adapters/Vectors, mine are as quiet as my other tubes, that is, very quiet. It might be important to note that plugged into the Vectors, the C3g's are using the LD's internal AC heaters. Is the noise worse than what you hear with a pair of 6HM5 or 6AK5? Maybe they will quiet down after more burn in..... Otherwise, those adapters would seem to be the prime suspects.....


----------



## gibosi

>> Six 6J4Ps (Russian equivalent of the 6AU6/EF94) arrived in today's mail:
  
 I had forgotten all about those 6J4Ps... I got a bunch of them for a few dollars and they were all noisy. And even after burn-in, they didn't quiet down even a little....  
  
 I am willing to part with these for cheap if anyone is interested. lol


----------



## Johnnysound

oskari said:


> 199 (or 1199) indicates the type. Please see the following link.
> 
> 
> http://myweb.tiscali.co.uk/g8hqp/audio/brimarcodes.html
> ...


 
  
 Yes, I think so.     Following that mysterious Brimar codes, 2G5 indicates the  date,  should be 2nd. week of july, 1955 or 1965,  and the 1199 should mean a 6AU6 tube type.    Sadly,  the 1199 = 6AU6 code does not appear in the list  provided, but this is an incomplete list  and that number  is not assigned to any other tube...


----------



## Uncle AL

trolldragon said:


> The second amplifier?
> 
> I'd try a gain of 5 and see what you think, right now you have it set to 3.



First MK IV SE returned on warranty due to finish problem. LD responded well and sent replacement, but amp has much lower output. Set gain to 5, ON-OFF. Volume must be set to 50 (12 O'Clock) for comfortable listening. Audio quality is excellent. Just lower than expected output.


----------



## Oskari

gibosi said:


> I had forgotten all about those 6J4Ps...


 
  
 Rest assured that Google will not forget. An image search for _ef94 russian_ handily delivered that photo of yours.


----------



## Oskari

johnnysound said:


> Yes, I think so.     Following that mysterious Brimar codes, 2G5 indicates the  date,  should be 2nd. week of july, 1955 or 1965


 
  
 Somehow 65 seems more plausible to me.


----------



## i luvmusic 2

I was about to Butcher my MK III for the socket adapters then i changed my mind so i end up doing this instead installed 4 Pin XLR socket and upgrade the Electrolytic Caps to Film Caps.


----------



## Acapella11

A few questions to all the 6SN7 users if you don't mind: Do you find a great difference in SQ between the 6SN7 tubes? Which is your favourable tube and why? And which is the most transparent/detailed one?


----------



## jazzwave

acapella11 said:


> A few questions to all the 6SN7 users if you don't mind: Do you find a great difference in SQ between the 6SN7 tubes? Which is your favourable tube and why? And which is the most transparent/detailed one?



 


My fav so far Sylvania VT-231 

Some user said VT-231 Tung-Sol, round black plates is the best

6sn7-tube-addicts
http://www.head-fi.org/t/479031/6sn7-tube-addicts


~ron~


----------



## MIKELAP

acapella11 said:


> A few questions to all the 6SN7 users if you don't mind: Do you find a great difference in SQ between the 6SN7 tubes? Which is your favourable tube and why? And which is the most transparent/detailed one?


 
 As power tube in LD or in general ?


----------



## mordy

Hi A11,
  
 With the risk of rousing the ire of the 6SN7 "addicts", my favorite 6SN7 is a 1960's RCA with a thin heater wire on top. Haven't found anybody mentioning this tube anywhere. If you are lucky (or diligent/patient) you can find these for a few dollars.
  
 That said, I have not tried the exotic and expensive 40's tubes - so I cannot really compare with the $100 tubes.
  








 This tube is a rebranded RCA with the name Hoffman. If you look carefully you can see the little wire on top. These tubes are nice as drivers as well as power tubes.


----------



## Acapella11

jazzwave said:


> acapella11 said:
> 
> 
> > A few questions to all the 6SN7 users if you don't mind: Do you find a great difference in SQ between the 6SN7 tubes? Which is your favourable tube and why? And which is the most transparent/detailed one?
> ...


 
  


mordy said:


> Hi A11,
> 
> With the risk of rousing the ire of the 6SN7 "addicts", my favorite 6SN7 is a 1960's RCA with a thin heater wire on top. Haven't found anybody mentioning this tube anywhere. If you are lucky (or diligent/patient) you can find these for a few dollars.
> 
> ...


 
  
 Dear jazzwave and Mordy, thank you for the answers, it would be nice if collect a few more suggestions. I will look out for the tubes mentioned above.
  
  


mikelap said:


> As power tube in LD or in general ?


 
  
 Hi Mikelap, as power tube mainly. Although I would hope that the priority list as driver tubes would be the same with the only difference being that the matching would change of course.


----------



## siles1991

wow how long has it been xD I'm still using my RCA 6DT6A, thinking of trying get more outta from my MKIV SE now ! What direction should I take! Hopefully something that a electronically challenged person like me can handle.


----------



## gibosi

acapella11 said:


> A few questions to all the 6SN7 users if you don't mind: Do you find a great difference in SQ between the 6SN7 tubes? Which is your favourable tube and why? And which is the most transparent/detailed one?


 
  
 In my experience there are significant sonic differences among the 6SN7, not only between brands, but also within the same brand over the years. And in fact, there are differences between 6SN7 manufactured by the same company at the same time. Here I am referring to Sylvania, which manufactured Chrome Domes, VT231's and the three-hole Badboys all at the same time.
  
 That said, nearly all these tubes are very fine. And I think it is safe to say that any of these can shine in the right system. Again, it really comes down to synergy. So I would expand on Mordy's advice and suggest that you try several cheap pairs: For example, RCA, Tung-Sol, Sylvania, Raytheon, CBS/Hytron, National Union, and Hitachi, to help you find your favorite brands. And then, as I believe that the 1940's and early 1950's are the best, you might want to try some of these earlier tubes.
  
 Used as drivers, my favorite is the 1940's Sylvania 6SN7W. However, the early 1950's Chrome Dome provide a sound that is quite close, lacking just a little warmth. Paired with a relatively warmer driver, they could be great.


----------



## bbmiller

mikelap said:


> acapella11 said:
> 
> 
> > A few questions to all the 6SN7 users if you don't mind: Do you find a great difference in SQ between the 6SN7 tubes? Which is your favourable tube and why? And which is the most transparent/detailed one?
> ...


 
   
 Quote:


jazzwave said:


> 6sn7-tube-addicts
> http://www.head-fi.org/t/479031/6sn7-tube-addict


  

 I too have been finding your answers to Acapella11 question very informative! I have particularly found  jazzwave  link to the other forum very good! Which led me to some browsing on my own to answer the question in regard to inexpensive power tubes. Which eventually led me to the criteria set out by this person below.


> RE: Inexpensive Sylvania 6SN7GTA​ 67.84.135.83​
> Posted by Neff on July 18, 2010 at 05:07:58 In Reply to: RE: REVIEW: Tung-Sol 6SN7GTB Tubes posted by *steven d* on July 17, 2010 at 05:05:28:
> 
> 
> ...


 
 With each leads me to further wonder if one wanted to go with the criteria set out by the person above could any of you all give me a link to a good seller that would definitely meet all criteria set forth by the person above for a 6SN7GTA(or a before 1957 6SN7GTB) including a fair price?

 Also I do not know how in eBay I managed to generate this link "Showing items imilar to... Two 6SN7 GTA/GTB  Sylvania Angle Plate Chrome Top Two 6SN7 GTA/GTB Sylvania Angle Plate Chrome Top "Reference Graded Pair"  but I am wondering if angle plates are the same as  'Y' plate in the person above criteria?
  
 One more also if I may further beg you all's indulgence? If none of you could send me to the type of seller I desire you to link me to could you give me some criteria and how to find a seller that meets all those criteria. I mean will I have to write to eBay sellers and hope they will explicitly answer me in a timely manner or are there other better ways to ensure a seller meets a list of criteria for the tube they are selling?


----------



## gibosi

bbmiller said:


> I too have been finding your answers to Acapella11 question very informative! I have particularly found  jazzwave  link to the other forum very good! Which led me to some browsing on my own to answer the question in regard to inexpensive power tubes. Which eventually led me to the criteria set out by this person below.
> With each leads me to further wonder if one wanted to go with the criteria set out by the person above could any of you all give me a link to a good seller that would definitely meet all criteria set forth by the person above for a 6SN7GTA(or a before 1957 6SN7GTB) including a fair price?
> 
> Also I do not know how in eBay I managed to generate this link "Showing items imilar to... Two 6SN7 GTA/GTB  Sylvania Angle Plate Chrome Top Two 6SN7 GTA/GTB Sylvania Angle Plate Chrome Top "Reference Graded Pair"  but I am wondering if angle plates are the same as  'Y' plate in the person above criteria?
> ...


 
  
 1) The first thing I look at is the seller information block. If a seller has 500 or more transactions and a positive feedback rating of at least 98%, I consider them to be a reliable seller. I have purchased over 800 tubes from many, many different sellers, world wide, and have had only a handful of problems, and even then, these problems were resolved by the seller, or in one case, by eBay, to my satisfaction.
  
 2) You need to learn how to recognize the construction used by Sylvania (or any other tube you are considering.). There is no shortcut. In the end, you need to spend a fair amount of time examining as many pictures as you can find.
  
 3) And then, armed with this knowledge, when you find a tube(s) you are interested in, examine the pictures very closely. If the pictures are poor, ask the seller to provide better pictures. In the case at hand, 6SN7GTA should be clearly seen on these tubes. The plate style should be easy to determine. And the date codes should be visible. If not, and the vendor is not cooperative, go elsewhere. Searching for "sylvania 6SN7" today yielded almost 600 listings. These tubes are not rare. Take your time. And don't pull the trigger until you are convinced you are buying exactly the tubes you want. 
  
 Cheers


----------



## gibosi

Well, on the chance that some of you are getting bored with the current tubes, I humbly suggest another group of twin triodes:
  
 6350
 6463/CV5404/CC86E and
 ECC813
  
 Evidently these tubes are used in the Audio Note, Ongaku, M8, M9+
  
 6350
  
 The 6350 are the most common tubes in this group:
  
 RCA 1959                                                                                 Sylvania (IBM) 1957
  

  
 The 6463's are less common. That said, there appear to be a ton of GE's, and much more rarely, Philips and Telefunken.
  
 And finally, the ECC813 appears to have been manufactured only by RFT.
  
 These tubes are similar to the 12AU7 and 5687 groups in that they have a center tap allowing their use in both 12 and 6 volt systems. However, the pin-out is different than any other tube I have tried. Essentially, it is the 12AU7 pinout with the cathodes and grids swapped out:
  
  9 Pin socket                                 Left LD socket                    Right LD socket
  
 1 plate section 2                                                                                   5
 2 cathode section   2                                                                            2
 3 grid section 2                                                                                    1
 4 heater - external PS                                                                           
 5 heater -tie to 4                                    
 6 plate section 1                                        5
 7 cathode section 1                                   2
 8 grid section 1                                         1
 9 heater center tap to external PS
  
 Have fun!


----------



## gibosi

gibosi said:


> 2) You need to learn how to recognize the construction used by Sylvania (or any other tube you are considering.). There is no shortcut. In the end, you need to spend a fair amount of time examining as many pictures as you can find.


 
  
 I think I cannot emphasize too much how important it is that you take the time to study the construction of these tubes. You simply cannot count on most vendors to know what it is they are selling. It is not that they are dishonest, they just simply don't know. For example, sometimes you will see a pair of Mullard 6SN7GT, made in England on eBay for a hefty price. Well, Mullard NEVER EVER manufactured the 6SN7GT. Moreover, a close examination of the pictures reveals flying saucer getters! Maybe these tubes were manufactured in England, but if so, Russian factory equipment was used. The vendor simply doesn't know what he has.... And I pity the poor soul who spends the big bucks for these "Mullard" tubes. The only way you can be sure you are getting the real deal is to do your homework.
  
 Cheers


----------



## sgbwill2

gibosi said:


> Well, on the chance that some of you are getting bored with the current tubes, I humbly suggest another group of twin triodes:
> 
> 6350
> 6463/CV5404/CC86E and
> ...


 
 Why tempt me with more tubes! haha. Just received my 5687 GR 5 star's today(1961-62) and am extremely happy with them. Upgrade to 6f8g and 6sn7's to my ears, and there is no base distortion now at all allowing me to listen to the LD with low impedance headphones finally! As I am enjoying these tubes so much I will most likely purchase some more 12.6v tubes which you have just stated. My poor wallet


----------



## stvn758

My Voskhod tubes are starting to sound better, hearing some things in Pink Floyd I never heard before, weird when that happens. My 6HM5 EC900 EI Yugoslavia also arrived today, must remember I need to set the jumpers before using them. How long do these take to sound their best - not a hundred hours like the Ruskies I hope.


----------



## gibosi

sgbwill2 said:


> Why tempt me with more tubes! haha. Just received my 5687 GR 5 star's today(1961-62) and am extremely happy with them. Upgrade to 6f8g and 6sn7's to my ears, and there is no base distortion now at all allowing me to listen to the LD with low impedance headphones finally! As I am enjoying these tubes so much I will most likely purchase some more 12.6v tubes which you have just stated. My poor wallet


 
  
 Not too fast!!  I have yet to find a suitable adapter to allow these tubes to be used in a stock LD power tube socket. All I have found to date are 6463 to 6SN7 which could then be plugged into the 6SN7 adapters you were using.
  
 Inserting two adapters between tube and socket is certainly not optimal or pretty, but it would work....


----------



## sgbwill2

gibosi said:


> Not too fast!!  I have yet to find a suitable adapter to allow these tubes to be used in a stock LD power tube socket. All I have found to date are 6463 to 6SN7 which could then be plugged into the 6SN7 adapters you were using.
> 
> Inserting two adapters between tube and socket is certainly not optimal or pretty, but it would work....


 
 Seems I am too eager haha. hopefully there are some suitable adapters out there as I would very much like to try some of these


----------



## bbmiller

gibosi said:


> bbmiller said:
> 
> 
> > I too have been finding your answers to Acapella11 question very informative! I have particularly found  jazzwave  link to the other forum very good! Which led me to some browsing on my own to answer the question in regard to inexpensive power tubes. Which eventually led me to the criteria set out by this person above.
> ...


 
 OK - I don't know if you think asking this is less than kosher because it is continuing to ask for a shortcut, but is there anything like a picture guide to the parts of the tube you need to know in all their variations or even some of their variations?
  
 I also know the basic parts of the tube are the plate (cathode), grid, anode, and heater. But are there other parts of tubes I need to know about? You mentioned the getter for example are there still other parts?
  
 After I know all the part names I would want to know about to learn about say Sylvania  6SN7 GTA/GTB do I simply use the part names like say "gathers in all their variations" in image search engines or are there better searching strategies you all who have already gone through the process could suggest? Did Sylvania back in the day put out guides to that big deal at the time tubes and explain their tube constructions and their variations complete with the names of specific part variations you could explicitly search for in image search engines?


----------



## Nic Rhodes

aren't 6463 part of the ECC86 family?


----------



## jazzwave

Quote from some sites, 6SN7 option, in general.

http://flagshipaudio.blogspot.com/2009/07/getting-best-sound-out-of-6sn7-tubes.html

http://vinylsavor.blogspot.com/2014/02/tube-of-month-6sn7.html

http://www.wiredstate.com/forum/viewtopic.php?t=8265&f=11

But its depend on your amp design, some time cheaper tube deliver better sound than the expensive one.
So, try directly in your system,listen the sound is the best way.

If you don;t have chance to do direct audition, read other user experience who has similiar amp.
But sometime not mach with your taste, one person said good but other probably say ;well this tube is good but not enough bass..


Good luck and enjoy with your 6SN7 adventure

~ron~

.


----------



## gibosi

nic rhodes said:


> aren't 6463 part of the ECC86 family?


 
  
 The 6GM8/ECC86 is often suggested as a replacement for the 6463. However, the pinout is different. The 6GM8/ECC86 has the same pinout as a 12AU7, whereas the pinout of the 6463 swaps the cathode and grid assignments. Moreover, when I read the data sheets, it seems to me that these tubes were designed for different uses. The 6463 is a 10,000 hour tube designed for use in computer circuits. The 6FM8/ECC86 appears to have been designed for use as a VHF amplifier and mixer for use in automobile radio sets. 
  
 Even so, for those who are setup to run 12AU7 tubes, the 6GM8/ECC86 might well be worth trying.


----------



## Nic Rhodes

Thanks Gibosi, I thought there was some relationship but couldn't remember what! Checking my stock I just have mostly GE and some Telefunken 6463s but have never used them in anger yet.


----------



## gibosi

bbmiller said:


> OK - I don't know if you think asking this is less than kosher because it is continuing to ask for a shortcut, but is there anything like a picture guide to the parts of the tube you need to know in all their variations or even some of their variations?
> 
> I also know the basic parts of the tube are the plate (cathode), grid, anode, and heater. But are there other parts of tubes I need to know about? You mentioned the getter for example are there still other parts?
> 
> After I know all the part names I would want to know about to learn about say Sylvania  6SN7 GTA/GTB do I simply use the part names like say "gathers in all their variations" in image search engines or are there better searching strategies you all who have already gone through the process could suggest? Did Sylvania back in the day put out guides to that big deal at the time tubes and explain their tube constructions and their variations complete with the names of specific part variations you could explicitly search for in image search engines?


 
  
 References such as these might exist, but if they do, I don't know about them....
  
 In the end, "a picture is worth 1000 words". For example, these are the tubes that gave rise to the "Chrome Dome" moniker. They were manufactured in the late 1940's into the early 1950's by Sylvania. You will notice that the shiny getter splash is kind of dirty. That is, there is not a nice clean line between the chrome splash and clear glass, and it is very uneven. Further, the getter splash covers more than 1/2 of the bottle. The later Sylvania tubes, with clean and neat getter splashes, covering only the very top of the tube are different, and in my opinion, not as good. 
  
 There are some physical differences among the Chrome Domes, but to my ears they all sound the same. So my conclusion is short base, tall base, 2-hole plates, 3-hole plates, all these late 1940's / early 1950's heavily chromed Sylvanias are virtually the same tube.
  
 Sylvania 6SN7GTs 1952 (left) and 1949 (right)
  
 Most have 3-hole plates, but the 1949 tube has 2-hole plates and bottom mica similar to the 6SN7W. Also, you will notice that one has a short base while the other has a taller base.
  

  
  
 Sylvania 6SN7GTAs, both 1953


----------



## mordy

Hi G,
  
_"the shiny getter splash is kind of dirty. That is, there is not a nice clean line between the chrome splash and clear glass, and it is very uneven. Further, the getter splash covers more than 1/2 of the bottle."_
  
 Thank you for clarifying this. Checked my inventory of Sylvania 6SN7 tubes. Found one real chrome dome from 1953, but the other tubes I have from 1954, 1955 and 1957 with a chrome top are not chrome domes. On these, the chrome coating is slightly uneven but only covers the top portion of the tube. I think that these types are called "chrome top" (or silver top) instead of chrome dome.
  
 Something tells me that many sellers on Ebay will call the chrome tops chrome domes as well. And some will say that the 2 hole (or three hole) tube is _the_ tube to have. Depends on how many you have to sell I guess...
  
 Anyhow, I am now in C3g land and exploring. They sound very good, kind of 5687 on steroids - they have more of _everything_. Have to get used to these tubes and try a few power tube combinations until I can form a detailed opinion. But it really seems that they are as great as people say.
  
 Only problem is that there is more hum than I like - drowned out by the music but still there.


----------



## TrollDragon

I dislike HUM on any level, even if it is drowned out by the music. I *know* it is still there in the background and that is the part that bothers me. Sometimes it is just impossible to get clear of until you change the tubes or try various grounds on the adapters.


----------



## mordy

Hi TD,
  
 At normal to loud  listening levels I do not hear any hum, but cranking up my system very loud (beyond normal listening levels) there is always some hum. However, with these Cg3 tubes the hum appears much earlier, even at normal listening levels.
  
 Would appreciate it if you could tel me how to ground the adapters.


----------



## MIKELAP

trolldragon said:


> I dislike HUM on any level, even if it is drowned out by the music. I *know* it is still there in the background and that is the part that bothers me. Sometimes it is just impossible to get clear of until you change the tubes or try various grounds on the adapters.


 
 Should get the c3g tubes  next week hope theres no hum with adapters ,i tried to insulate heater wires to see if that helps will see soon enough.


----------



## superdux

no hum here using C3G tubes


----------



## Acapella11

With C3gs tubes (socket extender -> adapter), I have a very weak hum. I need to crank up to 10 o'clock to hear any. However, I hardly ever get close to 10 o'clock when listening. The Ei 6HM5 show the same hum at 2 o'clock. Well, the C3gs is a high gain tube after all. So, in summary, I am not bothered but would be curious about a grounding solution.


----------



## mordy

Hi,
  
 Had one of my teenage grandsons over yesterday - wanted to show off my wonderful system, so I asked him to pick his favorite tune on his iPhone and I would play it through my system.
  
 Connected the iPhone - the music was compressed, highly processed and awfully recorded. Tried to talk to him about dynamic range, soundstage, imaging etc - forget about it! I think he understood what I meant (I demonstrated it to him with different recordings) but he didn't care.
  
 I know what an iPhone is capable of; it can play quite nicely. However, it seems that this generation has been brought up on mediocre music reproduction without any appreciation for great sound.
  
 Same thing with headphones that are in style again. Another grandson showed me his Dr Dre headphones. The look was cool, but the sound was just way to bass heavy; muddy and unpleasant.
  
 Do I have the wrong impression that kids don't care about great sound reproduction any more?


----------



## hypnos1

acapella11 said:


> With C3gs tubes (socket extender -> adapter), I have a very weak hum. I need to crank up to 10 o'clock to hear any. However, I hardly ever get close to 10 o'clock when listening. The Ei 6HM5 show the same hum at 2 o'clock. Well, the C3gs is a high gain tube after all. So, in summary, I am not bothered but would be curious about a grounding solution.


 
  
 Hi A11.
  
 Looks like the high (yes!) gain, plus higher transconductance of the 'S' is highlighting something somewhere in your system/surroundings etc...I was going to point the finger at possibly the adapters and/or extenders (or tubes, even!), but as it appears with the 6HM5s, the blame seems to lie elsewhere, lol.
  
 I personally have never had any hum whatsoever from mine - perhaps the MKIV SE has better grounding/isolation than the MKIII?
  
 I shall have to do a much more in-depth comparison between my original set-up - with the tube pins soldered direct to the wires-cum-pins, straight into the amp's sockets - and that using encased tubes into adapters...with ears poised for HUM!  
	

	
	
		
		

		
			





.
  
 Will post my findings in due course...


----------



## hypnos1

mordy said:


> Hi,
> 
> Had one of my teenage grandsons over yesterday - wanted to show off my wonderful system, so I asked him to pick his favorite tune on his iPhone and I would play it through my system.
> 
> ...


 
  
 I fear you may well be right, mordy...one must be careful not to over-generalise, of course, but everywhere _I_ look (and listen) around me it seems either horrendous bass rules, or equally horrendous (what passes for...) treble!...SIGH...


----------



## sgbwill2

hypnos1 said:


> I fear you may well be right, mordy...one must be careful not to over-generalise, of course, but everywhere _I_ look (and listen) around me it seems either horrendous bass rules, or equally horrendous (what passes for...) treble!...SIGH...


 
 Being 21 myself and considered of the younger generation I can say there are a select few out there who don't fall into the trap of buying over advertised, hyped up pieces of crap such as beats and iphones. Though I have had numerous debates with my friends on the subject who all seem to be blind to the fact that these products are overpriced and under-perform compared to other alternatives often at a much cheaper price. Though because high quality audio products aren't as well advertised as say beats, skullcandy etc and they aren't necessarily as aesthetically pleasing they will never get any recognition from the younger generations unfortunately =/


----------



## hypnos1

sgbwill2 said:


> Being 21 myself and considered of the younger generation I can say there are a select few out there who don't fall into the trap of buying over advertised, hyped up pieces of crap such as beats and iphones. Though I have had numerous debates with my friends on the subject who all seem to be blind to the fact that these products are overpriced and under-perform compared to other alternatives often at a much cheaper price. Though because high quality audio products aren't as well advertised as say beats, skullcandy etc and they aren't necessarily as aesthetically pleasing they will never get any recognition from the younger generations unfortunately =/


 
  
 Hi sgbwill2..agreed..."a select _few_", lol!....sad that otherwise reasonably intelligent people can be so easily swayed by 'fashion/the look', obviously OTT (nay puerile!) marketing etc. etc.
  
 Still, we live in hope, n'est-ce pas?...


----------



## Acapella11

gibosi said:


> In my experience there are significant sonic differences among the 6SN7, not only between brands, but also within the same brand over the years. And in fact, there are differences between 6SN7 manufactured by the same company at the same time. Here I am referring to Sylvania, which manufactured Chrome Domes, VT231's and the three-hole Badboys all at the same time.
> 
> That said, nearly all these tubes are very fine. And I think it is safe to say that any of these can shine in the right system. Again, it really comes down to synergy. So I would expand on Mordy's advice and suggest that you try several cheap pairs: For example, RCA, Tung-Sol, Sylvania, Raytheon, CBS/Hytron, National Union, and Hitachi, to help you find your favorite brands. And then, as I believe that the 1940's and early 1950's are the best, you might want to try some of these earlier tubes.
> 
> Used as drivers, my favorite is the 1940's Sylvania 6SN7W. However, the early 1950's Chrome Dome provide a sound that is quite close, lacking just a little warmth. Paired with a relatively warmer driver, they could be great.


 
  
 Thank you for your 6SN7 starter guide. It looks like 6SN7 rolling will get more from my wallet than the good old heptodes, lol. I have bought a pair of Raytheon advertised as from the 50s to start with. It was still a decent price.
  
 Quote:


hypnos1 said:


> Hi A11.
> 
> Looks like the high (yes!) gain, plus higher transconductance of the 'S' is highlighting something somewhere in your system/surroundings etc...I was going to point the finger at possibly the adapters and/or extenders (or tubes, even!), but as it appears with the 6HM5s, the blame seems to lie elsewhere, lol.
> 
> I personally have never had any hum whatsoever from mine - perhaps the MKIV SE has better grounding/isolation than the MKIII?


 
  
 You are probably right that there is somewhere a hum issue, I considered the USB-connection, will try my optical again to see if it is that. Moving my USB-cable to a front port reduced the background.


----------



## Oskari

nic rhodes said:


> aren't 6463 part of the ECC86 family?


 
  
 Whoever first wrote CC86E probably meant the E86CC. Even those are very rare.
  

http://www.roehrenhuette.de/42490/43046.html


----------



## gibosi

Searching Google, the E86CC is even more rare than the CC86E. Neither the Radio Museum, the National Valve Museum nor the Duncanamps sites have any information on this tube in their databases. The Radio Museum and Duncanmaps do list the CC86E but the National Valve Museum does not. Anyway, it certainly seems that both of these tubes are exceedingly rare.


----------



## Oskari

Radio Museum's source for CC86E is not firsthand information and TDSL's might be the same. The source could be mistaken.
  

http://www.radiomuseum.org/tubes/tube_cc86e.html
http://frank.pocnet.net/short/054/2/271.pdf


----------



## Acapella11

mordy said:


> Hi,
> 
> Had one of my teenage grandsons over yesterday - wanted to show off my wonderful system, so I asked him to pick his favorite tune on his iPhone and I would play it through my system.
> 
> ...


 

 Hi Mordy, I am guessing being interested in the quality of music reproduction and not only the tune is a personal preference and many just done care much. It was a good effort you did and maybe he will come back to this topic much later.
 What is important to keep in mind IMO is that many of these teenagers wear headphones as expensive accessories and thereby raising the awareness of headphones in the public. Even if not all of them may convert to proper enthusiasts, this may result in more members sharing the head-fi interest. Also, once these teenagers earn proper money, some of them might be more inclined to buy themselves a nice setup at home, which could further increase the headphone industry giving all of us a greater variety and quality of gear. However, you probably cannot get them all.


----------



## Oskari

Can you put a positive spin on rap, too?


----------



## i luvmusic 2

Are they even singing?


----------



## mordy

Hi sgbwill2, A11 and Oskari,
  
 You all bring up valid points - kids today tend to care about the tune much more than how it is reproduced. One positive aspect of the huge interest in portable music is the great proliferation and selection of earbuds and headphones, and I have no doubt that this interest has resulted in a lot of advances in music reproduction at the high end as well.
  
 I am sure that it is true the looks play a big role as well. Reminds me of a true story: A little boy wanted a certain pair of shoes, but the shoe store did not have the correct size; only a size too small. The little boy insisted that they felt fine, but the salesman and the mother knew that they were too small. The boy refused to be persuaded to wait for the right size and finally said: People can only see how it looks, not how it feels!


----------



## gibosi

oskari said:


> Radio Museum's source for CC86E is not firsthand information and TDSL's might be the same. The source could be mistaken.
> 
> 
> http://www.radiomuseum.org/tubes/tube_cc86e.html
> http://frank.pocnet.net/short/054/2/271.pdf


 
  
 I see what you mean now...  
  
 In the end, I figure that if I ever come across a tube labeled CC86E or a E86CC, it's not worth a premium price, as it appears these are just 6463s with different paint. On the other hand, if I can get one on the cheap, it might be nice to have.


----------



## hypnos1

OK then guys...re the ongoing 'C3g hum'...
  
 Have just finished another pair of adapters (phew! - but getting the hang of 'em, lol!), and have reinstated the 6H30P-DRs so as not to be confused by the very slight hum in one channel from either the GEC CV2523 or (more likely) the external PS/regulator...
  
 Anyway, with a pair of superdux's used C3g, try as I might I cannot hear the slightest hint of hum...so either the MKIV SE _is_ better grounded/isolated than the MKIII or it would appear there are other factors at play with those who are experiencing it (assuming of course it isn't down to the occasional hint of hum with new tubes, that then gradually disappears 
	

	
	
		
		

		
			





).
  
 So I can only hope that sufferers are able to identify and rectify the source, or that it does not intrude noticeably and spoil the magic of these wonders...


----------



## i luvmusic 2

Cold solder can sometimes create a hum routing your wires properly will help too,I just learned all these stuff by building the CRACK and the SEX.Back when i used to have those long wired adapters i used to twist and bundle the wires to reduced the hum and sometimes by doing that the hum disappeared.I build my 6SN7 to 12AU7 adapter with a hum so i throw it away then i build a next one but this time i leaved the wires inch longer then twisted it a couple of times before i push it back inside the copper couplings then glue it in and clamp it 24Hours later that adapter is Dead quiet.


----------



## MIKELAP

hypnos1 said:


> OK then guys...re the ongoing 'C3g hum'...
> 
> Have just finished another pair of adapters (phew! - but getting the hang of 'em, lol!), and have reinstated the 6H30P-DRs so as not to be confused by the very slight hum in one channel from either the GEC CV2523 or (more likely) the external PS/regulator...
> 
> ...


 
 So far on the adapters i made i never experience hum unless it was induced by a tube ,but that same adapter on an other system produced a hum why i dont know ,maybe tube related also like i said on the C3G adapters i just finished i insulated the wires with alluminium foil 
	

	
	
		
		

		
		
	


	




 and covered them with shrink wrap will see if that helps. on a previous adapter i used a usb cable that was insulated also and no hum to report . So if i ever get those C3G tubes which i think  will be this week they shipped on the 5th will get to try them and post my tutorial after .                                                                                                                                                                                                                                                                            By the way mordy how long did it take to get yours .


----------



## mordy

Hi Mikelap,
  
 Der Deutche Post took about 8 days, but that is to the US. My understanding is that the Canadian post is slower....
  
 About the hum I don't think that the adapters are causing it. There is less hum with the 5687 tube than the C3g, but I always had hum, but only at very loud listening levels, and therefore usually not noticeable.
  
 With the C3g I notice it more. I have a snake pit of electric wires in my listening room, and I don't have the knowledge and patience to go looking for a ground loop. I probably have some thirty different items plugged in. Lately something generates tremendous static when I am running my system, and any AM radio in an adjacent room is unlistenable -haven't figured out yet which specific item causes it. If I shut off my system it goes away.
 When I shut off the heaters to the 6080 power tubes but left the tubes in place, the hum returned to pre-C3g levels (not objectionable). Funny thing, I cannot listen to headphones without the 6080 tubes lighting up, but there is enough signal that I can listen to my speakers at satisfying levels. I guess that my ss amp gets enough of a signal to play the music through the speakers.
  
 The last item made me aware of how much the power tubes contribute to the sound - it is an all around difference like warm, flat beer compared to cold and fizzy beer, if u get the gist...


----------



## MIKELAP

It's going to be 8 business days tomorrow good chance tomorrow i would think U.K. usually is 7-8 days as a matter of fact expecting a Fivre 5R4GY rectifier from over there will see .I do like the LD alot with 6SN7'S as power tubes and a 6SU7GTY as driver very nice bass. Thanks mordy


----------



## MIKELAP

Received C3G tubes this morning i like the bass on those tubes .Happy to report no hum with adapters ,happy with that .


----------



## hypnos1

mikelap said:


> Received C3G tubes this morning i like the bass on those tubes .Happy to report no hum with adapters ,happy with that .


 
  
 Well done M...now for that tutorial, lol!!
  
 As I mentioned a while back, I liked your use of those pin straightener/protectors - hadn't really considered them before, silly me! So much better and easier for not a lot of money 
	

	
	
		
		

		
		
	


	




.
  
 Do you have the base C3g or the S version? Now I've been able to do more A/B comparison while testing adapters, the S definitely has the edge - but then it could always be down to the particular tubes used, although it does tie in with what I thought a LONG while back...
  
 Yes, bass is real nice - not just in extension, but even more so in detail/texture. Actually,the same goes for the entire frequency range IMHO - the degree depending on the powers used...which brings me to another confirmation with all this testing - ie with the (expensive!) 6H30P-DRs in the hot seat, they just come nowhere near my 6AS7Gs...NOWHERE NEAR!
  
 And if your tubes are new, they will just keep getting better and better...trust me! 
	

	
	
		
		

		
		
	


	




.


----------



## hypnos1

mordy said:


> Hi Mikelap,
> 
> Der Deutche Post took about 8 days, but that is to the US. My understanding is that the Canadian post is slower....
> 
> ...


 
  
 Hi mordy.
  
 Looks like yours could be the same situation as A11 - ie the higher gain (and transconductance if using the 'S') is highlighting something somewhere in the system/environment...not an easy hunt sometimes, for sure lol! (Actually, my MKIV SE has very slight hum in both channels - excluding the 6AS7G/PS one - when not fed a signal, but disappears completely when fed...).
  
 And yes, as we have found before, the power tubes DO (or CAN!) make a big difference and yet I still find people on other threads saying the opposite - I just cannot understand it!! 
  
 ps. 4 more adapters and still NO HUM...


----------



## MIKELAP

hypnos1 said:


> Well done M...now for that tutorial, lol!!
> 
> As I mentioned a while back, I liked your use of those pin straightener/protectors - hadn't really considered them before, silly me! So much better and easier for not a lot of money
> 
> ...


 
 Before posting Tutorial gotta test those adapters and so far so good they have been running for 3 hours now no problems and more importantly no hum . you gotta be careful when inserting tube in and removing them they were very hard ,will try and find better quality Loctal sockets .I have both the C3G AND C3GS .As for pin straightners its a easy solution combined with 7 pin sockets it makes the pins sturdier when hot glued together


----------



## hypnos1

mikelap said:


> Before posting Tutorial gotta test those adapters and so far so good they have been running for 3 hours now no problems and more importantly no hum . you gotta be careful when inserting tube in and removing them they were very hard ,will try and find better quality Loctal sockets .I have both the C3G AND C3GS .As for pin straightners its a easy solution combined with 7 pin sockets it makes the pins sturdier when hot glued together


 
  
 Yep, those sockets sure are TIGHT so, people, you must work those tubes in VERY carefully - as M says...
  
 It sounds to me like you don't seal everything in with epoxy resin? I'm sure that's what helps minimise interference in my case, as opposed to twisting/covering with foil..(plus, those wires and joints aren't going _anywhere_, lol! - but once sealed in..._that's it!!_).


----------



## MIKELAP

hypnos1 said:


> Yep, those sockets sure are TIGHT so, people, you must work those tubes in VERY carefully - as M says...
> 
> It sounds to me like you don't seal everything in with epoxy resin? I'm sure that's what helps minimise interference in my case, as opposed to twisting/covering with foil..(plus, those wires and joints aren't going _anywhere_, lol! - but once sealed in..._that's it!!_).


 
 Once you JB weld or epoxy the sockets and you cover them with pre glued shrink wrap thats all you can do to keep those sockets in there Im more afraid for the Loctal since the lip of the socket is not long Personnally i will leave them in adapter no need to remove them anyways the more you do you risk ripping out the socket time will tell .


----------



## hypnos1

mikelap said:


> Once you JB weld or epoxy the sockets and you cover them with pre glued shrink wrap thats all you can do to keep those sockets in there Im more afraid for the Loctal since the lip of the socket is not long Personnally i will leave them in adapter no need to remove them anyways the more you do you risk ripping out the socket time will tell .


 
  
 I agree with you there, M - once those tubes are in KEEP 'EM IN!!


----------



## stvn758

My Voskhods are starting to sound superb, definite leap up from the stock ones.


----------



## MIKELAP

​  
C3g ADAPTER TUTORIAL FOR LITTLE DOT MK3 AMP​ _First of all many thanks to Troll Dragon for helping me out with this project and for the schematic ._​ *ATTEMPT THIS AT YOUR OWN RISK*​ My advice to you is that pictures #1 and #2 should be on your screen or printed out as you will reference them often during build.  Have fun.
 REMEMBER ON 7 PIN SOCKETS PINS ARE INVERTED (FOR EXAMPLE PIN #7 ON PICTURE TOP VIEW BECOMES PIN#1 WHEN SOCKET IS FLIPPED OVER) READ BELOW.
                                                                  
                                                                     
  
                       
                                                                      
  
                                                                      
  
                                                                      
  
                                                                      
  
                            #5                                      
  
  
                                                              MAKING PINS FOR YOUR 7 PIN SOCKETS                                                   
                                                  What I did is buy a roll of 1/32¨or 1 mm diameter copper wire that I straightened out with a drill and a vise or a pair of vise grips                                                   as shown in this video.
  
                                                                 
  
                                                               
  
                                                               
                                                               
  
                                                               
  
                                                               
  
                                                                        
  
                                                      
  
                                                                               CUTTING COPPER CASING                                                      
 This piece is referred to as a copper reducer 1¨ to 1/2¨ actual sizes are approx 1.025¨ x 5/8¨ inch or 26 mm x 15.8 mm approx. Luckily the only operation that is required to do on the copper reducer is to shorten the length, once cut our piece should be around 1 3/16¨ (about 30 mm) tall.  The main thing is to try and cut the piece straight. You can use a saw but more than likely it will cut crooked you will have to use a file to straighten the piece out.  What I tried is this,  I found a socket extender that fits into the smaller diameter of the piece. It was a bit loose so I put a small piece of electrical tape around it so now the socket extender fits snugly into the copper casing. Then I wrap the 2 pieces with more electrical tape so they don't separate. Then I insert the square part into the drill chuck and tighten. That part of it is solved.
                                                           
  
                                                  
 Next what I use is a grinder with a cutting disk. To hold down the drill i used my adjustable work bench. I taped the speed button on the drill so I don't have to press on it myself .  If you have a reversible drill make sure it turns in the opposite direction of your grinder as it will cut better.  BE CAREFUL WHEN DOING THIS!  ALWAYS 2 HANDS ON THE GRINDER!
                                                            
  
                                                                SOLDERING WIRES TO 7 PIN SOCKET                                   
 Cut your 14 - 28 gauge wires 11/8¨ long and apply solder to each end of wires as it will be easier to solder them to lugs on the sockets.  Always check the connection you've just soldered with your multimeter. When your finished connecting them all or after each wire is soldered and tested, I slide a piece of shrink wrap over each wire and use the soldering iron to shrink the tubing.  Now it is possibly best to twist heater wires #4 and #5 and WRAP THEM IN A FOIL to isolate them and hopefully prevent hum. REMEMBER WHEN LOOKING UNDER THE SOCKET POSITIONS ARE INVERTED, refer to picture #2.
                                                                                                          
  
  
                                                CONNECTING YOUR 7 PIN SOCKET TO THE LOCTAL SOCKET                                                                
 I use a PanaVise to hold the assembly, I like this vise it swivels and is very versatile. You might also need was is called a Third Hand as this to can be very useful to hold the small parts like in picture #5
                                          
 Your multimeter will be very handy for the next step. Insert 7 pin socket in copper casing and put in your vise, then you will need to find with your tester the wire you want to solder, refer to picture #1 and #2.  Before soldering insert a piece of shrink wrap on the wire and push it up the wire, not doing so will shrink the tubing in the wrong place when you solder the wire to the lug. If you cannot use shrink wrap, use electrical tape to isolate each wire from one another. After soldering the wires to the lugs, tape around all the wires to isolate them from the copper pipe. Once finished prepare a batch of JBweld epoxy resin apply to lenght of socket then push the socket into the pipe and tape it in place.let dry  Then retest all the connections to make sure everything is ok.  To finish the adapter i use 1 3/16¨or 30 mm dia.(3:1) shrink wrap with glue already inside the membrane. This will cover the upper part of copper pipe and overlap the loctal socket  without covering the pin holes. To cover the 7 pin sockets use 3/4¨ inch shrink wrap with glue inside if you cannot find wrap with glue, you can always use contact cement The shrink wrap should keep the sockets in place . What i do to shrink the wrap is use my soldering iron this way adapter does not heat up to much . To finish this tutorial i would recommend against removing the C3G tube to often from adapter as the Loctal socket might come apart from copper casing  .I noticed tube is very hard to remove  so if removing make shure you hold on to socket .                                                                                                                                                                                                                                                                                                                                                                                                                                                                
  
                                                                                                                                                                                                                                                                                                   
                                                             
    So this is the finish product if you need any information or clarifications on how to make this adapter dont hesitate to contact me .Thanks guys . Michel (MIKELAP)


----------



## TrollDragon

You are most welcome MIKELAP!
 Excellent tutorial. I am glad that it all worked out, they have Zero hum and look great to boot!


----------



## hypnos1

WARNING!!!... Possible C3g problems...
  
 It looks like my initial disaster with 2 Ss wasn't down to my workmanship on the adapters after all....I have been racking my brains as to what could possibly have caused them to go 'pop' and crack - now I know!!
  
 There is obviously a weakness in the pin/glass boundary, whether general or batch-specific, because as I just tried to (carefully) work another S into a (tight) socket...CRACK...breaking glass, and instant death of course.
  
 So all I can suggest is you loosen those socket pin connectors as best you can, by working them with something a _shade_ larger, and be ULTRA careful when inserting the tube - with the least lateral movement possible...then PRAY.
  
 I cannot believe this turn of events, but is obviously something that needs our utmost care and attention because there is no way of gaining prior warning, of course...


----------



## hypnos1

mikelap said:


> C3g ADAPTER TUTORIAL FOR LITTLE DOT MK3 AMP​ _First of all many thanks to Troll Dragon for helping me out with this project and for the schematic ._​ *ATTEMPT THIS AT YOUR OWN RISK*​ My advice to you is that pictures #1 and #2 should be on your screen or printed out as you will reference them often during build.  Have fun.
> REMEMBER ON 7 PIN SOCKETS PINS ARE INVERTED (FOR EXAMPLE PIN #7 ON PICTURE TOP VIEW BECOMES PIN#1 WHEN SOCKET IS FLIPPED OVER) READ BELOW.
> 
> 
> ...


 
  
 Great work, M!
  
 Further to your (and my) comments on the tightness of the sockets we use, I have just posted a warning that relates directly to this aspect which I now know for sure is VERY BAD NEWS for either all C3g or just certain batches...please read...


----------



## MIKELAP

hypnos1 said:


> WARNING!!!... Possible C3g problems...
> 
> It looks like my initial disaster with 2 Ss wasn't down to my workmanship on the adapters after all....I have been racking my brains as to what could possibly have caused them to go 'pop' and crack - now I know!!
> 
> ...


 
 My feeling exactly i saw this type of socket looks better and you spread apart 2 plates instead of lining the pins in the holes . Like i said the less you remove them the better  .


----------



## i luvmusic 2

Well done Mike......


----------



## bbmiller

Well I am not planning on building a C3g  adapter any time soon, but nevertheless that picture above MIKELAP posted has been bugging me. I have been following the discussions here my understanding was the C3g   tube is a single pentode used as a single triode in the little dot III and IV amplifiers. I didn't understand it to be a double anything pentode or triode or anything else, but that picture seems to be indicating  it is a double or at least an adapter that goes in both seven pin tube sockets. Please and is confusion. It's just bugging me.


----------



## MIKELAP

bbmiller said:


> Well I am not planning on building a C3g  adapter any time soon, but nevertheless that picture above MIKELAP posted has been bugging me. I have been following the discussions here my understanding was the C3g   tube is a single pentode used as a single triode in the little dot III and IV amplifiers. I didn't understand it to be a double anything pentode or triode or anything else, but that picture seems to be indicating  it is a double or at least an adapter that goes in both seven pin tube sockets. Please and is confusion. It's just bugging me.


 
 This picture only indicates pin numbering  it is not a C3G adapter


----------



## mordy

Hi Mikelap,
  
 Congrats on the detailed tutorial and great pictures; obviously a lot of work went into this - great presentation.
  
 To me it is a little intimidating because you need much more than a screw driver LOL.
  
 Hi hypnos 1,
  
 Re the breakage issues with the C3g tubes it has me worried. I already lost a C3gS tube, and it was not abused in any way. After having rolled tubes many hundreds of times I never had any tube break while rolling it until now with the Siemens C3g.
  
 The crack in the glass is clearly visible, and the white getter flash indicates loss of vacuum. The metal tube shield  as well as the metal loctal base have been removed in this picture.

  
 The loctal base is not attached to the tube at all, but only held in place by crimping the metal tube shield to the base. Possibly this arrangement allows for some movement of the glass tube inside the metal jacket. If the pins are pushed hard because of a tight tube socket, the glass may be pushed against the tube shield, resulting in breakage, Or maybe the glass envelope is fragile in general.
  
 It could be that the traditional way of removing a tube by wiggling it from side to side (tube rolling) should be avoided with this tube, and that it should just be lifted out straight up. This may be difficult to do with a tight fit. In the past we used rubber fingers to remove the small 6AK5 style tubes. Maybe a bigger piece or some kind of rubber grip should be used. Does anybody have advice on this?


----------



## MIKELAP

mordy said:


> Hi Mikelap,
> 
> Congrats on the detailed tutorial and great pictures; obviously a lot of work went into this - great presentation.
> 
> ...


 
 First of all thanks mordy for your support ,and yes it was alot of work but fun at the same time . About the C3G tube removal what i did to remove tube from adapter was to first of all remove adapter from LD then i simply use a small flat screwdriver  by inserting screwdriver between tube and socket and twist  screwdriver from side to side slowly lifting up the tube a section at a time and go all around the tube and eventually it comes out i feel its way safer than pulling it out by hand . But i wont be removing tube to often will just leave it there thats even better i think.


----------



## mordy

Hi Mikelap,
  
 Had the same idea about taking out the adapter from the socket and using a flat blade screw driver when I woke up this morning LOL. We'll see how the tube fares......


----------



## MIKELAP

mordy said:


> Hi Mikelap,
> 
> Had the same idea about taking out the adapter from the socket and using a flat blade screw driver when I woke up this morning LOL. We'll see how the tube fares......


 
 Bad news a C3GS just went dead tried another it works,looks like those tubes are very fragile  .I might add it was a new tube that died ,right now i have the use pair on will see how that goes .


----------



## TrollDragon

mikelap said:


> Bad news a C3GS just went dead tried another it works,looks like those tubes are very fragile  .I might add it was a new tube that died ,right now i have the use pair on will see how that goes .


 
 Good thing you got them cheap and not for the high price from eBay....


----------



## MIKELAP

The tube is cracked on the bottom probably when i put it in.  Damm!


----------



## MIKELAP

trolldragon said:


> Good thing you got them cheap and not for the high price from eBay....


 
 Ya ,so its only half as painfull lol. C'est la vie !


----------



## hypnos1

mikelap said:


> Bad news a C3GS just went dead tried another it works,looks like those tubes are very fragile  .I might add it was a new tube that died ,right now i have the use pair on will see how that goes .


 
  
 Sorry for your loss (my count is now 3 Ss - 2 at ebay prices! 
	

	
	
		
		

		
		
	


	




),
  
 Yep, M, as I mentioned - the pin/glass boundary is definitely rather weak, which is VERY surprising given how well made the tube appears otherwise. Those tight sockets are just too much for it.
  
 Luckily the remedy is very simple - the hole connectors can be widened  by working a small 1.5mm screwdriver (like those in (cheap) sets for repairing spectacles etc.) in and out until not much force is needed to insert it ...et voila, the tube can be pushed in STRAIGHT with no need to 'work/wiggle' it, which of course (now we know, lol!) is what has been the problem all along...It can even be pulled out straight with no need for killer side to side force - if necessary!!
  
 If only I had twigged this with my first disaster....but such is life...???!!!


----------



## MIKELAP

hypnos1 said:


> Sorry for your loss (my count is now 3 Ss - 2 at ebay prices!
> 
> 
> 
> ...


 
 Sometimes the learning curve is steep damm i could of learned with one tube of the use pair lol. BUT NO !!!!!!           Breath in Breath out Breath in Breath out ....... I feel better now DAMM!!!!!!


----------



## Nic Rhodes

Are you both using Loctal sockets as opposed to Octals?


----------



## MIKELAP

nic rhodes said:


> Are you both using Loctal sockets as opposed to Octals?


 
 You forgot one word CHEAP loctal sockets !!!!!!!!!!!!!!!


----------



## Nic Rhodes

The best ones I used were from Teflon ones from Billington but bought mine 20 years ago but have seen then much more recently. The tubes breaking is unusual.


----------



## stvn758

I have seen some quite expensive tubes on EBay, are they valuable in their own right or strictly valued for their musical value. I am somewhat pleased at how cheaply I have been able to start tube rolling - how often can you say that when you go about improving something. 
  
 Is there a holy grail of tubes out there?


----------



## MIKELAP

nic rhodes said:


> The best ones I used were from Teflon ones from Billington but bought mine 20 years ago but have seen then much more recently. The tubes breaking is unusual.


 
 i bought these yesterday they look better maybe more forgiving when inserting tube  compare to other  picture


----------



## Nic Rhodes

are they NOS?


----------



## MIKELAP

nic rhodes said:


> are they NOS?


 
  
 Yes they are .           *Ceramic Loctal-8, B8G (Sylvania, 1938) socket*


----------



## Nic Rhodes

They look nice. I have used ones like this for years
  
 http://www.ebay.co.uk/itm/190371869274?ssPageName=STRK:MESINDXX:IT&_trksid=p3984.m1436.l2649


----------



## Acapella11

mikelap said:


> C3g ADAPTER TUTORIAL FOR LITTLE DOT MK3 AMP​ _First of all many thanks to Troll Dragon for helping me out with this project and for the schematic ._​ *ATTEMPT THIS AT YOUR OWN RISK*​ My advice to you is that pictures #1 and #2 should be on your screen or printed out as you will reference them often during build.  Have fun.
> REMEMBER ON 7 PIN SOCKETS PINS ARE INVERTED (FOR EXAMPLE PIN #7 ON PICTURE TOP VIEW BECOMES PIN#1 WHEN SOCKET IS FLIPPED OVER) READ BELOW.
> 
> 
> ...


 
  
 Great detailed guide Mikelap and a lot of effort obviously went into this! Seems, I would need to go a bit shopping before I could put those together 
	

	
	
		
		

		
		
	


	







. Really great stuff!
  
  
 Dear Mordy, on a different topic, I was close to post this in the Feliks forum but it would have been maybe a bit too much of an hijack. Just tried my HE-500 (/w Norse/Norne Skuld 2 cable) the first time since the C3GS upgrade and, I must say, quite a nice match indeed. So, Mordy, the HE-400i could be a good option for your super tuned LD, even though people say planar magneto headphones and OTL amps are not a good match.
 Interestingly, the humming is even lower, the background blacker with the HE-500 as compared to the HD800. Just to put this into proportion, even with the HD800, the humming is not distracting at all on my setup as it only appears in the background when the volume is increased beyond normal listening levels.


----------



## mordy

Hi stvn758,
  
 It is my impression that the price of a tube isn't an indication that it will sound better. Certain tubes have been popularized by certain sellers who have been able to drive up prices. Other tubes are rare and hard to find and so fetch more.
  
 In addition, a certain tube can be found for a few dollars, whereas a professional seller may charge you ten times more for the same thing. An inexpensive 60's 9pin tube may sound just as good as an old 40's octal tube going for 15 times the price.
  
 Take the time to read the Little Dot Tube Amps: Vacuum Tube Rolling Guide and you will find plenty of advice and insights as well information on pricing. Just don't make the mistake and start from the beginning! Instead, read backwards from the latest posts. In this way you will be knowledgeable about the latest advances found by the erudite members of this forum.
  
 Have fun!


----------



## mordy

C3g breakage:
  
 We have at least three members of this forum that have accidentally broken expensive hard to get tubes. I would venture that between us we have rolled many thousands of tubes, and next to none or none have broken from normal handling. (I am not speaking of accidentally dropping a tube .)
  
 Siemens is a long established tube manufacturer, and it seems strange that they would design a tube with such a weakness that normal insertion would break it. IMHO these tubes have a design flaw, or we got tubes from bad batches.
  
 The whole thing does not make sense.......


----------



## Acapella11

Dear Mikelap, comparing your 6SN7/C3GS LD MKIII with your Woo, what is your verdict?


----------



## TrollDragon

Well I can say that my Fostex T50RP's with @bluemonkeyflyer's DBV #3 style tuning mod, works superbly with the LD amplifier IMHO.
  

  
 The HE-400i's should sound just as good!


----------



## MIKELAP

acapella11 said:


> Dear Mikelap, comparing your 6SN7/C3GS LD MKIII with your Woo, what is your verdict?


 
 Well im not sure actually let me explain ,first off as i explain the LD is not as thin sounding as with other tubes  and as matter of fact its the best ive ever heard of the Littledot MK3 the sound is fuller more balanced heres the catch its something i didnt realise actually .In my setup i use the LD as a preamp with my Burson Conductor what i notice is that actually the sound with LD is warmer more bassy compared to the Conductor thats more neutral sounding so it seems to add that little extra balance in the mix that i like when the 2 are combine , because to my well traveled ears i dont ear much difference between my Conductor LD setup and the  WA2 . After when i remebered this i connected the LD only to the Dac out jacks of my Conductor and the sound was alot warmer not as detailed  not as pleasing so guess what i did Conductor preamp jacks here i come lol.


----------



## JazzVinyl

mordy said:


> C3g breakage:
> 
> We have at least three members of this forum that have accidentally broken expensive hard to get tubes. I would venture that between us we have rolled many thousands of tubes, and next to none or none have broken from normal handling. (I am not speaking of accidentally dropping a tube .)
> 
> ...




I wonder if removing the C3g sheaths is contributing to the breakage problem? In my case, I left the sheaths on, and still broke one, simply by inserting and removing it from a tight loctal socket. I didn't actually hear mine go crack...just assume it did, since it stopped working. 

I believe superdux had a couple stop working on him, too, so wonder if we have had four members break a C3g?


----------



## MIKELAP

jazzvinyl said:


> I wonder if removing the C3g sheaths is contributing to the breakage problem? In my case, I left the sheaths on, and still broke one, simply by inserting and removing it from a tight loctal socket. I didn't actually hear mine go crack...just assume it did, since it stopped working.
> 
> I believe superdux had a couple stop working on him, too, so wonder if we have had four members break a C3g?


 
 The one i broke was stock you would not think that they are that fragile its the first time that happened to me, so gotta be extra  careful taking it out or putting it in the adapter .mine was cracked on the bottom maybe quality or thickness of glass is at fault here . I you want to remove the alluminum cover just file the bottom edge  of alluminum cage all around  and it will become loose you then separate bottom part from top part


----------



## hypnos1

mordy said:


> C3g breakage:
> 
> We have at least three members of this forum that have accidentally broken expensive hard to get tubes. I would venture that between us we have rolled many thousands of tubes, and next to none or none have broken from normal handling. (I am not speaking of accidentally dropping a tube .)
> 
> ...


 
  
  


mikelap said:


> The one i broke was stock you would not think that they are that fragile its the first time that happened to me, so gotta be extra  careful taking it out or putting it in the adapter .mine was cracked on the bottom maybe quality or thickness of glass is at fault here . I you want to remove the alluminum cover just file the bottom edge  of alluminum cage all around  and it will become loose you then separate bottom part from top part


 
  
 Hi mordy and MIKELAP.
  
 Agreed...doesn't make much sense...it seems to me the most likely explanation is that in some batches the special glass needed for the pin base was not up to specification - if it was a flaw in ALL tubes, there would surely have been info on that somewhere on the Web, or at the likes of JAC Music etc. So I think we have been EXTREMELY unlucky, lol!
  
 Fortunately, at least now we know where we must take EXTRA care, and that it is absolutely vital to make sure the socket hole connectors are worked so as to enlarge them, and such that the tube can be inserted with a STRAIGHT push and without the need for forceful 'rolling'...
  
 I have now tested 4 'worked' adapters using our "cheap!" sockets (of which many even more expensive ones use the same sort of connector!), and even with multiple insertions/removals - a case of do or die!! - all is now OK.
  
 So hopefully there will be no more catastrophes - I for one have had enough for a VERY long time, lol!


----------



## superdux

Sorry for your losses!I asked the seller if he knew anything about breaking tubes but he bought up the batch of tubes aswell and stated he was sorry and that he'd rather like satisfied customers and as he has gone out on C3G tubes offered to send some C3M as a replacement. I told him i'd ask the forum members if they are interested but as what i have read so far C3M need more power.Anyway if someone with broken tubes is interested i would have to buy a batch from him but he would give me 5 C3M tubes for free.
 I also still have some normal C3G here and have no problems with them. The only failure that occured to me was that a chinese adapter failed on me and as they are stupidly expensive it was a relief that the chinese seller sent a replacement.


----------



## gibosi

Unfortunately, the C3m has a different pinout than the C3g, so an entirely different adapter would be necessary. Moreover, the C3m has 20 volt heaters as opposed to 6.3 for the C3g. In fact, the LD 1+ can run 20 volt tubes, but again, the pinout is different than a C3g. Of course, if someone with a 1+ is up to using the C3g tutorials posted by Hypnos1 and Mikelap to make a pair of adapters, it looks like only pins 2, 3 and 5 are different.


----------



## hypnos1

superdux said:


> Sorry for your losses!I asked the seller if he knew anything about breaking tubes but he bought up the batch of tubes aswell and stated he was sorry and that he'd rather like satisfied customers and as he has gone out on C3G tubes offered to send some C3M as a replacement. I told him i'd ask the forum members if they are interested but as what i have read so far C3M need more power.Anyway if someone with broken tubes is interested i would have to buy a batch from him but he would give me 5 C3M tubes for free.
> I also still have some normal C3G here and have no problems with them. The only failure that occured to me was that a chinese adapter failed on me and as they are stupidly expensive it was a relief that the chinese seller sent a replacement.


 

 Hi superdux.
  
 It is indeed unfortunate that your supplier didn't realise (?) the C3gSs were pretty sure to have been of those batches I mentioned in my last post - I say the 'S's, because I'm sure it's no coincidence that all my 3 breaks were with the S, and yet both straight used C3g had no problems, with just the same sort of treatment...I'm only sorry he may have put you in an embarrassing position - your motives and actions have been beyond reproach and now with hindsight, plus the required care taken, hopefully your good works shall prevail, lol!
  
 I'm afraid the C3m are of no real use to us - a pity, though.... (now if he'd offered them with no strings attached, at least they could have been put on ebay 
	

	
	
		
		

		
		
	


	




!!).
  
 Keep the faith...


----------



## hypnos1

Having just peeked at the Schiit Lyr Tube Rollers thread, I feel I must put into perspective our recent problems/losses....when I see what some owners are paying for tubes we left behind a good while back, my own losses now seem a lot less painful!...NO WAY do I(personally) regret one iota what has transpired of late...and NO WAY would I want to turn back the clock, lol! 
	

	
	
		
		

		
		
	


	




.
  
 (Excuse me while I continue my chuckle...
	

	
	
		
		

		
		
	


	




)...


----------



## i luvmusic 2

trolldragon said:


> Well I can say that my Fostex T50RP's with @bluemonkeyflyer's DBV #3 style tuning mod, works superbly with the LD amplifier IMHO.
> 
> 
> 
> The HE-400i's should sound just as good!


 
 Looks really nice TD.........


----------



## i luvmusic 2

Maybe the METAL shield is there for a reason.


----------



## MIKELAP

Is there a brand in particular of 6GU7 tubes that sound good i have a pair of Raytheon


----------



## hypnos1

i luvmusic 2 said:


> Maybe the METAL shield is there for a reason.


 

 Hi ilm2.
  
 Makes no difference as far as the 'cracking' problem is concerned - nearly all cases have been with shield on. Obviously it protects the glass envelope in risky environments, but in our case that shouldn't be a problem...hopefully! 
	

	
	
		
		

		
		
	


	




. It may just help with interference suppression, when (if) the central metal spigot is connected to ground via the tab in the socket, but I haven't encountered any such problems with just my 'bare' tubes...
	

	
	
		
		

		
		
	


	



  
 Cheers


----------



## mordy

Hi h1,
  
 Do you think that I a wire from the central pin on the loctal socket to ground on the LD chassis is doable, and would it lower the hum?


----------



## hypnos1

mordy said:


> Hi h1,
> 
> Do you think that I a wire from the central pin on the loctal socket to ground on the LD chassis is doable, and would it lower the hum?


 

 Hi mordy.
  
 Doable?...Yes.
 Easy?...Perhaps not so....
 Pretty?..No... (there would need to be the ground wire protruding out of the adapter (and/or extender) going to the case ground location point - unless you fancy drilling through the top of the case and fiddling around inside!...I take it that's a no-no, lol 
	

	
	
		
		

		
		
	


	




).
 Effective?...Who knows...as I have mentioned before, even with my tubes 'bare' and no sheath at all I have just deathly silence...
	

	
	
		
		

		
		
	


	




...so...
	

	
	
		
		

		
		
	


	




.
  
 On this subject of hum, further to my recent post on hum being present only when not being fed a signal, I decided to make sure once and for all that even that was not due to the C3gS - so in went the old Mullard stocks and lo and behold - slightly LOUDER!!...Knock-out punch from the C3g, methinks!! 
	

	
	
		
		

		
		
	


	




.


----------



## MIKELAP

Does anybody know if a C3G tube can be mounted horizontally ,for example a 6as7 can be as long as the planes of the filament are vertical .


----------



## TrollDragon

mikelap said:


> Does anybody know if a C3G tube can be mounted horizontally ,for example a 6as7 can be as long as the planes of the filament are vertical .


 
 I cant see why they couldn't be mounted horizontally...
  
  
 These loctal sockets from Yamamoto might help with the cracking of the tubes.
  
 Scroll down to the 8 Pin loctal *Order Number: 320-036-23*
 http://www.jacmusic.com/sockets/Socket-Yamamoto.htm
  
  
  
 They are Teflon so the chassis mounting tangs could be trimmed off very easily.


----------



## MIKELAP

trolldragon said:


> I cant see why they couldn't be mounted horizontally...
> 
> 
> These loctal sockets from Yamamoto might help with the cracking of the tubes.
> ...


 
 Funny i was just looking at those .Thanks


----------



## hypnos1

trolldragon said:


> I cant see why they couldn't be mounted horizontally...
> 
> 
> These loctal sockets from Yamamoto might help with the cracking of the tubes.
> ...


 
  
 Hi TD...like all things Yamamoto, beautiful; classy...but EXPENSIVE, lol!  With such an easy solution to the socket problem, are these gorgeous creatures really necessary?  
	

	
	
		
		

		
			





 
  
 ps.  IMHO the money (actually far less!) is better spent on using solid pure silver wire in the adapters, lol!...


----------



## gibosi

Some thoughts and observations regarding the breaking of C3gs:
  
 I have yet to have a C3g break on me using the Chinese adapters. Paying close attention, I notice that the pins go in with almost no resistance. It is the center tang that meets resistance as it "locks" in place. These are called "loctal" sockets, after all. Octals and glass miniatures were designed to use the pin-socket connection to keep the tube in place. Loctals were designed to use the central tang to hold the tube in place. And therefore, octals and glass miniatures have a more robust pin structure than the loctals.
  
 If there is too much resistance when inserting the pins on a loctal tube, it puts undue stress on the base of the tube. This is stress the tube was not designed to handle, and as we have noticed breakage may result. As others have suggested, widen the socket pin-holes so that the tube pins can be inserted easily but still snug enough to ensure good contact. It is the center tang that should "click-in" holding the tube securely in place.


----------



## MIKELAP

hypnos1 said:


> Hi TD...like all things Yamamoto, beautiful; classy...but EXPENSIVE, lol!  With such an easy solution to the socket problem, are these gorgeous creatures really necessary?


 
 Speaking for myself ,I would say yes,it is necessary  if you dont want to break out in a sweat everytime you remove or insert the tube lol.  the relief you have when inserting the tube guides the pins to the center of the hole compare that to our $2.00 socket .Were talking long term so imo i think its worth it in the end .7 pin sockets work well the octal also but the loctal dont have a good feel to them when i insert them so ill try better sockets next time .


----------



## mordy

Hi,
  
 Remember the old days of strapping the pins with small wires stuck into the sockets? Well, I thought that I could use this method to ground the center pin of the C3g tube. Took a length of 30 gauge wire, stripped both ends, and then inserted it inside the hole for the notched center guide pin making sure that the insulation would cover any area near a tube pin. There was no problem pushing in the tube with this arrangement. Then I connected the other end of the wire to a chassis screw for ground.
  
 Sorry to say - there was no difference at all regarding the hum. I tried this with a used C3g tube; the other socket has the C3gS in it, and I try to leave alone. However, the C3gS has a louder hum in my system.
  
 Did I connect it properly, or did I miss something? Is the wire too thin to connect to the ground?


----------



## hypnos1

mordy said:


> Hi,
> 
> Remember the old days of strapping the pins with small wires stuck into the sockets? Well, I thought that I could use this method to ground the center pin of the C3g tube. Took a length of 30 gauge wire, stripped both ends, and then inserted it inside the hole for the notched center guide pin making sure that the insulation would cover any area near a tube pin. There was no problem pushing in the tube with this arrangement. Then I connected the other end of the wire to a chassis screw for ground.
> 
> ...


 
  
 Hi m.
  
 Do all the chassis (case) screws provide a ground? And I would also have thought you need a thicker wire than that ...?


----------



## MIKELAP

mordy said:


> Hi,
> 
> Remember the old days of strapping the pins with small wires stuck into the sockets? Well, I thought that I could use this method to ground the center pin of the C3g tube. Took a length of 30 gauge wire, stripped both ends, and then inserted it inside the hole for the notched center guide pin making sure that the insulation would cover any area near a tube pin. There was no problem pushing in the tube with this arrangement. Then I connected the other end of the wire to a chassis screw for ground.
> 
> ...


 
 Found this   post # 3062           http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/3060


----------



## hypnos1

gibosi said:


> Some thoughts and observations regarding the breaking of C3gs:
> 
> I have yet to have a C3g break on me using the Chinese adapters. Paying close attention, I notice that the pins go in with almost no resistance. It is the center tang that meets resistance as it "locks" in place. These are called "loctal" sockets, after all. Octals and glass miniatures were designed to use the pin-socket connection to keep the tube in place. Loctals were designed to use the central tang to hold the tube in place. And therefore, octals and glass miniatures have a more robust pin structure than the loctals.
> 
> If there is too much resistance when inserting the pins on a loctal tube, it puts undue stress on the base of the tube. This is stress the tube was not designed to handle, and as we have noticed breakage may result. As others have suggested, widen the socket pin-holes so that the tube pins can be inserted easily but still snug enough to ensure good contact. It is the center tang that should "click-in" holding the tube securely in place.


 
 Hi gibosi!!
 You make a very good point re the different 'holding' principles, but I must admit 2 of my breakages came with what I would never call EXCESSIVE strain - I find it hard to believe a tube that needs to withstand high temperatures would be so 'fragile'...but...
  
 As for the "click-in" spigot, I myself found it did TOO good a job of holding - that _did_ require a great deal of force to remove and would certainly court disaster, which is why I snapped off the socket ground tab and widened the centre guide, as per my tutorial. I found that with the socket holes widened, the tube is held perfectly secure without the need for that spigot hold.
  


mikelap said:


> Speaking for myself ,I would say yes,it is necessary  if you dont want to break out in a sweat everytime you remove or insert the tube lol.  the relief you have when inserting the tube guides the pins to the center of the hole compare that to our $2.00 socket .Were talking long term so imo i think its worth it in the end .7 pin sockets work well the octal also but the loctal dont have a good feel to them when i insert them so ill try better sockets next time .


 
  
 Well, M, you pays your money (possibly a LOT!) and takes your choice. All I can say is that I found those first sockets to be absolutely fine after working the holes...no panic whatsoever 
	

	
	
		
		

		
		
	


	




.
  
 And why on Earth would anyone really want to remove the tube once in? (Unless performing multiple testings)...I certainly wouldn't, lol!!


----------



## MIKELAP

hypnos1 said:


> Hi A11.
> You make a very good point re the different 'holding' principles, but I must admit 2 of my breakages came with what I would never call EXCESSIVE strain - I find it hard to believe a tube that needs to withstand high temperatures would be so 'fragile'...but...
> 
> As for the "click-in" spigot, I myself found it did TOO good a job of holding - that _did_ require a great deal of force to remove and would certainly court disaster, which is why I snapped off the socket ground tab and widened the centre guide, as per my tutorial. I found that with the socket holes widened, the tube is held perfectly secure without the need for that spigot hold.
> ...


 
 Not with these sockets anyways lol .


----------



## Acapella11

Quite excited now.
 I received my Raytheon JAN CRP brown base tubes and my socket adapters from Hong Kong (http://www.ebay.com/itm/1pc-6SN7-TO-6CG7-6FQ7-tube-adapter-for-you-amp-/191082280257?ssPageName=ADME:L:OC:GB:3160) and I was waiting for the 9-pin vector socket extender.
 So far nothing out of the ordinary.
 Then I unpacked the socket adapters and found quite long pins extending from them... and tried to fit those directly into the power tube sockets. And it worked, WOW. I am in 6SN7-land faster than I thought and without socket adapters!
 This does not work for the happydiy998 C3G socket adapter.
  

  

  
 I am not doing any comparisons as of now but just enjoying the sound!
  
 EDIT: Alright, this is not it yet! It all works fine when using the HD800s but with the HE-500s I am getting some gain problems and distortions, so for the full fun of it, I will need to be patient... Hope it is not an incompatibility issue with the lower HE-500 impedance...


----------



## i luvmusic 2

mikelap said:


> hypnos1 said:
> 
> 
> > Hi TD...like all things Yamamoto, beautiful; classy...but EXPENSIVE, lol!  With such an easy solution to the socket problem, are these gorgeous creatures really necessary?
> ...


 
 Bottom picture i used similar to that (octal for my CRACK and SEX)it's a very nice socket when inserting tubes no need to put a  lot of  forced but pulling out the tubes it's  tight.I think it's designed to grip the tube pins.


----------



## MIKELAP

i luvmusic 2 said:


> Bottom picture i used similar to that (octal for my CRACK and SEX)it's a very nice socket when inserting tubes no need to put a  lot of  forced but pulling out the tubes it's  tight.I think it's designed to grip the tube pins.


 
 I am using these Woo adapters with my WA6 and its like butter either way very smooth very nice adapters what i ordered and will try next is these sockets hopefully they will be better but there coming from Russia so will let you know in about 1 month  if there good or not unfortunately  .


----------



## TrollDragon

mikelap said:


>


 
Now that is one _*fine*_ looking socket!​  ​  
​ *This is your next mission, should you choose to accept it.*​


----------



## MIKELAP

trolldragon said:


> Now that is one _*fine*_ looking socket!​  ​
> ​ *This is your next mission, should you choose to accept it.*​


 
 You mean a 596  those tubes are as rare as a 4% raise already got 5 RK 60 close enough .im getting  dizzy just looking at it


----------



## TrollDragon

That Woo gear is just too nice to look at and I don't think you should taunt us with pictures of them here... 
	

	
	
		
		

		
		
	


	



  
 I am relieved to see that the UGLY knob has been retired!


----------



## MIKELAP

trolldragon said:


> That Woo gear is just too nice to look at and I don't think you should taunt us with pictures of them here...
> 
> 
> 
> ...


 
 You mean this one  lol.


----------



## TrollDragon

Nooooo....​ UGLY knob is UGLY....​ ​


----------



## mordy

Hi,
  
 All you want to know about Woo adapters - around $50 each + shipping:
  
 http://www.head-fi.org/t/548267/new-product-universal-teflon-tube-adapter
  
 It seems to me that they will wire adapters to your specifications as well.


----------



## mordy

Usually I play music from my computer using iTunes where I have my CD library. Today I played a CD from my CD player and to my surprise the hum became significantly lower.
  
 If the hum comes from my computer connection, what can I do to lower the hum? Changing outlets used for the PC? Changing the wire that connects the PC to the receiver?
  
 Would appreciate any suggestions - thanks


----------



## MIKELAP

mordy said:


> Usually I play music from my computer using iTunes where I have my CD library. Today I played a CD from my CD player and to my surprise the hum became significantly lower.
> 
> If the hum comes from my computer connection, what can I do to lower the hum? Changing outlets used for the PC? Changing the wire that connects the PC to the receiver?
> 
> Would appreciate any suggestions - thanks


 
 Is your PC plugged into a power bar or in the wall


----------



## CITIZENLIN

mordy said:


> Usually I play music from my computer using iTunes where I have my CD library. Today I played a CD from my CD player and to my surprise the hum became significantly lower.
> 
> 
> 
> ...



 

Hi Mordy
I use PC to play most of the time but I don't get any hum with C3gs and 6sn7 combo. I would try different outlets first. Have you tried different player as well? JRIVER, JPLAY or FOOBAR. Do you have any other USB outlet that plugged in for mouse, keyboard, bluetooth or ect..... Try to unplug everything that are not necessary. Try to install "fidelizer.exe" http://www.windowsxlive.net/fidelizer/ . I hope you get rid of annoying hum.


Cheers


----------



## hypnos1

mordy said:


> Usually I play music from my computer using iTunes where I have my CD library. Today I played a CD from my CD player and to my surprise the hum became significantly lower.
> 
> If the hum comes from my computer connection, what can I do to lower the hum? Changing outlets used for the PC? Changing the wire that connects the PC to the receiver?
> 
> Would appreciate any suggestions - thanks


 
  
 Hi m.
  
 PCs seem to be a hotbed of possible gremlins - I gave up using my (expensive) Dell XPS laptop, with Windows 7 (used so as I could also play back my hi-res downloads)...too many strange noises occasionally ruining everything, and for which I could never suss the reason.
  
 So I got myself a relatively cheap Toshiba W8 tablet (8in, Windows 8), mainly to act just as a versatile media  player that can also output hi-res files, and for much less than many hi-res music-only-players! With the added benefit of full Windows 8 functionality if needed, lol!..(This thing has micro-SD slot for the storage; micro-usb slot  AND mini-HDMI slot...amazing for the money...).
  
 Anyway, using usb out into my Audiolab 8200CD's usb slot, the results are amazing...superb sound quality, and not the slightest hint of interference/distortion whatsoever. I very rarely now even bother with the excellent CD transport - especially as I can of course get loads of CDs (at full res) on a tiny card, plus the hi-res tracks. What more can one ask for, lol?!


----------



## hypnos1

acapella11 said:


> Quite excited now.
> I received my Raytheon JAN CRP brown base tubes and my socket adapters from Hong Kong (http://www.ebay.com/itm/1pc-6SN7-TO-6CG7-6FQ7-tube-adapter-for-you-amp-/191082280257?ssPageName=ADME:L:OC:GB:3160) and I was waiting for the 9-pin vector socket extender.
> So far nothing out of the ordinary.
> Then I unpacked the socket adapters and found quite long pins extending from them... and tried to fit those directly into the power tube sockets. And it worked, WOW. I am in 6SN7-land faster than I thought and without socket adapters!
> ...


 
  
 Hi A11.
  
 That's certainly good news re being able to lose those extenders...must improve things IMHO.
  
 And so now you can discover what our humble LDs are REALLY capable of achieving...(just wait 'til you are sucked into 6AS7G/6080 land, lol!! 
	

	
	
		
		

		
		
	


	




)...
  
 ps. If you would rather just stay in 6SN7 land for the powers (which is excellent territory anyway!), besides our findings, good info is to be had over at the 6SN7 Tube Addicts thread, and the 6SN7 Reference thread (in case you didn't already know...)


----------



## TrollDragon

Ignore the hum...
 Just imagine that you have one of the McIntosh MI-350's from the Woodstock wall of sound. Let the tunes roll and live in the moment!


----------



## hypnos1

trolldragon said:


> Ignore the hum...
> Just imagine that you have one of the McIntosh MI-350's from the Woodstock wall of sound. Let the tunes roll and live in the moment!




  
 A Toshiba W8 is a lot smaller (and cheaper) lol!!


----------



## Acapella11

Here is an example of how highly regarded the combination of 6SN7 driver and 6080 power tubes is. This is an Apex Teton, and you can have it at home for just $5,000 
	

	
	
		
		

		
		
	


	






  




  
 http://www.apexhifi.com/Teton.htm


----------



## Acapella11

mordy said:


> Usually I play music from my computer using iTunes where I have my CD library. Today I played a CD from my CD player and to my surprise the hum became significantly lower.
> 
> If the hum comes from my computer connection, what can I do to lower the hum? Changing outlets used for the PC? Changing the wire that connects the PC to the receiver?
> 
> Would appreciate any suggestions - thanks


 
  
 Hi Mordy,
  
 Just recently I had very similar questions and found that my USB-ports in the back are noisier than my front USB-ports to my DAC. The main culprit was probably my mouse. Are you using a dedicated DAC? If so, you could use an optical cable, which will uncouple PC and DAC. But generally, the optical connection is not regarded as the highest quality way out of the PC. The best one is probably a coaxial out, but you would need a dedicated sound card for this, in most cases. USB is good but you could suffer more interference. The optimal solution there is a proper galvanic uncoupling of DAC and PC but there is not a product I have tried. In a post before, the Shiit Decrapifier was suggested but I am not sure it provides proper galvanic isolation.
  
 Hypnos1's suggestion of a dedicated tablet, is a very good idea.
  
 And as Mikelap already pointed to, mains filtering can certainly improve sound quality further. Generally, the background becomes blacker and the stage greater. Don't know of a case it helped with humming (yet).
  
 As an alternative player, I can recommend the russian AIMP3 player, ofc with english interface 
	

	
	
		
		

		
		
	


	




. The sound quality is different to Jriver, more forward but very dynamic and it is free, Jriver can be tried for free for 30 days. I certainly prefer AIMP3 over Foobar.


----------



## MIKELAP

mordy said:


> Usually I play music from my computer using iTunes where I have my CD library. Today I played a CD from my CD player and to my surprise the hum became significantly lower.
> 
> If the hum comes from my computer connection, what can I do to lower the hum? Changing outlets used for the PC? Changing the wire that connects the PC to the receiver?
> 
> Would appreciate any suggestions - thanks


 
 i was checking out spec on my Burson Conductor and maybe the fact that i dont have any hum problems is related to having several power filters in the amp as described in this review  .I use the Consductors  DAC for my 4 amps that are plugged into it with no hum  problem all the amps are 2 to 3 feet away from PC maybe that helps to .I think you would also gain in sound quality  by using something else then itunes  player .What you need is this player  http://getmusicbee.com/download.html  its free  you can convert your files to FLAC  or several other formats you can rip your cd's to the player or scan your entire library to Musicbee  i have over 21.000 tunes on there and its still very fast,its less complicated than Foobar  plays hires files  up to 24 bit/192 i think you would gain in sound quality with a different player heres a screen shot of Musicbee the way i have it setup.Also if you need help theres a Forum and updates from time to time.
                                                                                                                                                                                                                                      Best thing i would think is to download program install a few cd's and convert them to the format you want just to get a feel for the player try features get use to it .Since theres album art you need to have proper tagging and usually when ripping a cd to Musicbee it gets album art automatically if not you Google image and put in folder .


----------



## mordy

Hi All,
  
 Many thanks for all the different suggestions on how to improve the sound. At one point I loaded in some 300 CDs to iTunes, but that took weeks. Is there a way to simply transfer over this music library to another program that can play these tunes in a format that is easy to use? It has to be able to display songs/artists/albums in alphabetical order, and it has to be easily searchable.
  
 I bought a Toshiba Chromebook not long ago, and I did notice that the sound card on it sounds quite good.
  
 Just tried a YouTube video now on the Chromebook connected to my system. THERE IS NO HUM UNLESS I PLAY AT EARSPLITTING LEVELS - WOW! Anything up to loud levels is free of hum. In addition this computer sounds better than my old Vista PC.
  
 How can I play my iTunes library through it since the ss hard drive only has 16GB of space? If I understand correctly, you cannot load programs onto the Chromebook but apps instead. It seems to me that the apps must be supported by Google. (I saw that Google let you play iTunes via a cloud server, but I don't feel like paying $10/month for the privilege of listening to my own CDs.)
  
 The Chromebook has a USB port.  Would it be possible to put the music that I have on iTunes on an external hard drive and play it through the chromebook?


----------



## MIKELAP

mordy said:


> Hi All,
> 
> Many thanks for all the different suggestions on how to improve the sound. At one point I loaded in some 300 CDs to iTunes, but that took weeks. Is there a way to simply transfer over this music library to another program that can play these tunes in a format that is easy to use? It has to be able to display songs/artists/albums in alphabetical order, and it has to be easily searchable.
> 
> ...


 
 The program i was talking to you about has the possibility to play in portable mode meaning that main files (program) are on your pc but you could use a EDD with your tunes on it .I know its possible to import your library files to MUSICBEE from itunes but you dont have enough space .Theres a wiki on Musicbee if you want to read in the end youll like it im shure here's the link and if you dont get your answer you can always register and ask on the forum i always got an answer very underrated player  im telling you.                         http://musicbee.wikia.com/wiki/MusicBee_Wiki


----------



## MIKELAP

mordy said:


> Hi All,
> 
> Many thanks for all the different suggestions on how to improve the sound. At one point I loaded in some 300 CDs to iTunes, but that took weeks. Is there a way to simply transfer over this music library to another program that can play these tunes in a format that is easy to use? It has to be able to display songs/artists/albums in alphabetical order, and it has to be easily searchable.
> 
> ...


 
 Like i said if you decide to try just install the program ill tell you where to get what you need ,rip a couple cd 's to the player familiarize yourself with it and  ill send you photo captures of my settings ,my settings are  very basic im talking about tagging and all of that .alot of stuff on that player i dont know about, after all i just want to listen to music not rack my brains . If you need help send me a  PM .ill help you best i can .


----------



## mordy

More thoughts on humming in my system: Tried my iPhone 4S connected to my receiver - the hum is louder than the Chromebook but not bad. Unplugged the USB charging cable and the hum level became quieter on a par with the Chromebook. It seems very clear that the hum comes from my Windows Vista PC.
  
 Now I hooked up an old Toshiba XP laptop that has my iTunes files on it. (Old = from around 2002). This laptop has about 10 min of battery life, so it is always connected to the wall outlet. Very low level hum, only noticeable when playing way too loud; same as the Chromebook.
  
 At this point I have this solution to the hum problem: Play iTunes on my old XP laptop (the sound card is prett good), and use the Chrome book for YouTube and the Internet. Not elegant, but it works - sort of....
  
 When time permits I am going to try other solutions to clean up my PC based on the suggestions received.
  
 I thank everybody who contributed for their help - thanks!


----------



## MIKELAP

mordy said:


> More thoughts on humming in my system: Tried my iPhone 4S connected to my receiver - the hum is louder than the Chromebook but not bad. Unplugged the USB charging cable and the hum level became quieter on a par with the Chromebook. It seems very clear that the hum comes from my Windows Vista PC.
> 
> Now I hooked up an old Toshiba XP laptop that has my iTunes files on it. (Old = from around 2002). This laptop has about 10 min of battery life, so it is always connected to the wall outlet. Very low level hum, only noticeable when playing way too loud; same as the Chromebook.
> 
> ...


 
 Are you using your PCsoundcard because before i installed my ASUS Essence STX soundcard things where alot noisier with STX soundcard power is connected separately soundcard is isolated from main power source in PC .


----------



## TrollDragon

Hi mordy,
 So have you actually taken the LD out of the equation to see if it is the cause of the hum? Computer or Chromebook, etc directly plugged into the receiver to see if any hum is still present?
  
 My first guess would be the flying wires on the LD hookup to be the main source of your hum.


----------



## tjw321

mordy said:


> More thoughts on humming in my system: Tried my iPhone 4S connected to my receiver - the hum is louder than the Chromebook but not bad. Unplugged the USB charging cable and the hum level became quieter on a par with the Chromebook. It seems very clear that the hum comes from my Windows Vista PC.
> 
> Now I hooked up an old Toshiba XP laptop that has my iTunes files on it. (Old = from around 2002). This laptop has about 10 min of battery life, so it is always connected to the wall outlet. Very low level hum, only noticeable when playing way too loud; same as the Chromebook.
> 
> ...


 
  
 If the hum isn't caused by interference over the mains, then an external USB DAC might be a quick and dirty (well, clean signal-wise, hopefully) and cheap way to carry on using your PC as a source and tame the hum. The cheapest one that I use is this one:
  
http://hifimediy.com/DACs/ready-made-dacs/U2-DAC
  
 For a little more cash, I also like the ODAC (available from several manufacturers - mine is Epiphany) or UD120. The form factor of the UD120 doesn't work that well with my dodgy laptop ports, though, and it gets a little hot - but it is probably the best value for money of the three.
  
 But, as with all audio gear, you can spend as much as you like. It quickly gets to the point where you may as well replace your PC 
	

	
	
		
		

		
			





.


----------



## David.M

I've milked this amp for 5 years now.

 Probably one of the best bang for the buck amps I've ever spent.
  
 But i think I'm going to have to let it go.
  
 I've rolled several mullard driver tubes on this amp. But i stuck with the EF95 M8100's.
  
 The Power tubes that i tried were
  
 Sovtek 6H30 P-I : Excellent after some burn in time. Clarity pops, but not in your face and bass reaches and extends decently.
  
 But guess what? The right driver of these sovtek's died on me 14 months in.
  
 No biggie, then i ordered the . . ...
  
 Electro-Harmonix 6H30pi ; Again, these were superb at voices and bringing everything closer and tightening up the whole audio chain.
  
  
 But guess what? 9 months in on these, I saw a spark/electricity type lightning/thunderstorm type scary bolts of flash coming out of the right tube one day.
  
 And apparently, that tube went out as well, and despite the face that i heard crackling noises after it went out, nothing serious happened to my headphones.
  
 Everything works great now on stock power tubes.
  
 But unfortunately, I'm not sure if i want to mess with it, cause i don't really want this amp taking down my headphones if something like this happens in the future.
  
 I might order some of the 6n6p-IR or the 6n23p voskhod(like someone recommended here) and try them as my power tubes, but I might just be thinking of upgrading to the Woo Audio line instead.
  
 Thank you little dot, you guys held me for this long, but i think it might be time to move on.


----------



## gibosi

david.m said:


> I've milked this amp for 5 years now.
> 
> Probably one of the best bang for the buck amps I've ever spent.
> 
> ...


 
  
 In each case you reference it was a tube that failed. And guess what? Woo amps use tubes too! So the only way to avoid blown tubes is to go solid state....


----------



## mordy

Hi David.M,
  
 Agree with Gibosi - it does not seem that the amp is at fault. A number of us on this forum have tried all kinds of things and modifications of this amp, and even when the amp was suspect in causing problems it turned out that was not the case. IMHO the LD MKIII is built like a tank and holds up very well.
  
 May I suggest that you do a simple upgrade to 6SN7 octal power tubes (needs adapters) + 6HM5 Ei driver tubes (plug and play). It will cost you a fraction of what a Woo amp costs, and will be a significant upgrade, requiring no special DIY skills.


----------



## mordy

Hi TD,
  
 The LD amp is plugged into an external loop on my receiver, and I can switch it in and out with a switch on the back of the receiver. When I use the ss receiver to play, using my PC as the music source, the hum decreases in volume, but it is still there.
  
 Based on this I would say that the main source of hum comes from my PC and not the LD amp. However, the C3gS tubes do increase the hum (less so with C3g tube). With other music sources, laptop, Chromebook and iPhone, the hum decreases significantly and is not a problem unless I play crazy loud.


----------



## mordy

Hi Mikelap,
  
 When I priced the ASUS Essence STX soundcard it was in the $180 range. To me it does not seem cost effective to upgrade an old Vista computer with the soundcard, although it would be nice. Meanwhile, I am exploring different solutions using what I have on hand. We'll see how successful I will be...
  
 Thanks for the tip on the Musicbee player. I installed it and like it. It picked up some 11.000 tunes from my computer (iTunes has some 6,000). Have to learn how to use it, but it looks like a good program. Is there a user's manual somewhere?
  
 I must say that I am impressed by the broad knowledge of the members on this forum - so many things to learn that I never even heard of! Thanks to all!


----------



## Acapella11

mordy said:


> Hi Mikelap,
> 
> When I priced the ASUS Essence STX soundcard it was in the $180 range. To me it does not seem cost effective to upgrade an old Vista computer with the soundcard, although it would be nice. Meanwhile, I am exploring different solutions using what I have on hand. We'll see how successful I will be...
> ...


 
  
 Dear Mordy, the investment in an external soundcard or DAC is not limited by the Vista notebook. The audiophile WASAPI interface was introduced with VISTA and it does not need any performance to play back music files. USB 2.0 would be important for your interface to the soundcard/DAC and enough hard disk space, which you could get with an external USB drive as well.
 My guess is that the performance level of your LD is way above the build in soundcards. It seems to me that the price of the soundcard/DAC should rather be compared to the LD than the PC. By upgrading the DAC you can venture into even sublimer SQ territories. Also, you can use the external soundcard/DAC of course with any other PC or device that masters the USB-port properly, maybe even the chromebook. Some enthusiasts entertain the idea that a good source is critical because you can never improve the SQ above the level of the original signal. Good luck on your hunt for better sound


----------



## MIKELAP

mordy said:


> Hi Mikelap,
> 
> When I priced the ASUS Essence STX soundcard it was in the $180 range. To me it does not seem cost effective to upgrade an old Vista computer with the soundcard, although it would be nice. Meanwhile, I am exploring different solutions using what I have on hand. We'll see how successful I will be...
> 
> ...


 
 One of the links i gave you is the  wiki for Musicbee almost everything you need to know is there but it is not entirely finished . i can send you screen shots of my settings if you want just PM me tell me what you  need .      http://musicbee.wikia.com/wiki/MusicBee_Wiki


----------



## mordy

Tried something else to lower hum - nothing earth shattering. Discovered that the Chromebook can accept external hard drives. Connected one of my external hard drives with part of my music library stored, and I can now play music without hum, but something is missing - don't know yet what it is. Could be that the files I am using are in MPEG Audio with some compression of the sound.


----------



## bbmiller

mordy said:


> Hi All,
> 
> Many thanks for all the different suggestions on how to improve the sound. At one point I loaded in some 300 CDs to iTunes, but that took weeks. Is there a way to simply transfer over this music library to another program that can play these tunes in a format that is easy to use? It has to be able to display songs/artists/albums in alphabetical order, and it has to be easily searchable.
> 
> ...


 
 I am wondering if some of the many hard drive docking stations available from someplace like Amazon will have one with the proper drivers for your Chromebook. They work with both USB 2 and USB 3, but USB three is far better if you have one of those on your Chromebook.

 Perhaps somebody mentioned this are ready but completely catching up on this thread is going to take me a while.


----------



## bbmiller

gibosi said:


> In each case you reference it was a tube that failed. And guess what? Woo amps use tubes too! So the only way to avoid blown tubes is to go solid state....


 
 I heard schiit MJOLNIR at headphone amplifier at the Rocky mountain audio Fest. It comes awful close to the best tube amps, but instead of using tubes it uses more tube like solid-state components. I quote"Mjolnir is the only dedicated headphone amp using an Circlotron-style topology with high-voltage JFET inputs and MOSFET outputs. Unlike other balanced headphone amps, Mjolnir is not simply two of the same amps in a box, with one run inverted. It’s a unique, inherently balanced stage that delivers both low complexity and very high performance."

 You don't have to use it with balanced headphone cables there are adapters to let you use headphones of the unbalanced cable type. They could not find the adapter to let me hear it on my Sennheiser unbalanced HD 600s, but borrowed balanced HD 600s from Sennheiser to let me listen to them and I was amazed at how good the sound was coming very close to the best tube amps.

 At the Sennheiser booth I really could not hear the difference between balance cables and unbalanced cables though.


----------



## gibosi

While I am sure the Mjolnir is a very fine amp, I am at heart more of a tinkerer and a tube roller than an audiophile, and so for me, solid state amps are boring. lol


----------



## Acapella11

6SN7 power tube update: Received my 9-pin socket savers and unfortunately got the exact same issues as before, the HE-500 would produce distortions, the HD800 would not. Prelimnary first info with the HD800s, the Raytheon JAN CRP brown base tubes seem well resolving with a good stage extension, sound warmer, more euphonic, with a looser bass as compared to my DRs. The DRs seem a bit more microphnic though. At the moment, I wouldn't necessarily choose the Raytheon 6SN7s over the DRs but I will keep the Raytheons in for now. Might be just needing proper burn in. Meanwhile, I am waiting for a pair of Sylvania 6SN7 to be delivered, maybe the HE-500 distortions are just something coming from these Raytheons... or 0.6 Amp heater current are just not enough.
  
 Musicbee sounds good. I am using it at the moment. Coming back with more details once I have had the time to compare it with AIMP3.


----------



## gibosi

I strongly suspect that the 6SN7's simply can't handle low Z cans all that well. I vaguely remember another poster reported an experience similar to yours, and found that a pair of 5687's were much better with his low Z cans.


----------



## hypnos1

acapella11 said:


> 6SN7 power tube update: Received my 9-pin socket savers and unfortunately got the exact same issues as before, the HE-500 would produce distortions, the HD800 would not. Prelimnary first info with the HD800s, the Raytheon JAN CRP brown base tubes seem well resolving with a good stage extension, sound warmer, more euphonic, with a looser bass as compared to my DRs. The DRs seem a bit more microphnic though. At the moment, I wouldn't necessarily choose the Raytheon 6SN7s over the DRs but I will keep the Raytheons in for now. Might be just a burn in issue. Meanwhile, I am waiting for a pair of Sylvania 6SN7 to be delivered, maybe I was just unlucky with these Raytheons.
> 
> Musicbee sounds good. I am using it at the moment. Coming back with more details once I have the time to compare it with AIMP3.


 
  
 Hi A11.
  
 I suspect you will need some better 6SN7s to trump the DRs...but _really_, you need to enter 6AS7G/6080 territory for the LD to fly high, lol! 
	

	
	
		
		

		
			





....feeling adventurous?...


----------



## Acapella11

gibosi said:


> I strongly suspect that the 6SN7's simply can't handle low Z cans all that well. I vaguely remember another poster reported an experience similar to yours, and found that a pair of 5687's were much better with his low Z cans.


 
  
 Yes, I suspect exactly that too. Thanks Gibosi.


----------



## Acapella11

hypnos1 said:


> Hi A11.
> 
> I suspect you will need some better 6SN7s to trump the DRs...but _really_, you need to enter 6AS7G/6080 territory for the LD to fly high, lol!
> 
> ...


 
  
 Hi Hypnos1,  6AS7G territory would certainly help


----------



## MIKELAP

acapella11 said:


> 6SN7 power tube update: Received my 9-pin socket savers and unfortunately got the exact same issues as before, the HE-500 would produce distortions, the HD800 would not. Prelimnary first info with the HD800s, the Raytheon JAN CRP brown base tubes seem well resolving with a good stage extension, sound warmer, more euphonic, with a looser bass as compared to my DRs. The DRs seem a bit more microphnic though. At the moment, I wouldn't necessarily choose the Raytheon 6SN7s over the DRs but I will keep the Raytheons in for now. Might be just a burn in issue. Meanwhile, I am waiting for a pair of Sylvania 6SN7 to be delivered, maybe I was just unlucky with these Raytheons.
> 
> Musicbee sounds good. I am using it at the moment. Coming back with more details once I have the time to compare it with AIMP3.


 
 Do you have the MK3 if you do just grind of the rings youll only have 1 adapter between tube and LD and if you like the rings they sell them on ebay but these would accept your 6SN7 .Speaking of adapter having problems with my 6SN7 adapter scratchy sound but only when i touch it besides that its fine ,expecting another one on chinease pony express lol seller wants me to send broken one back at my expense rightttttttt !                                                                                                                                                                                                                                                          Musicbee is a very nice player ive had it for several years , and you can give it the look you want .                                                                                                                                                                                                                                                                                                                                    Just in case you feel like cutting something with a Dremel .Notice that i did not cut all the way thru the rings at one point they will bend and you wont have any marks on your amp  .The 2 screws in the left ring will fall in the amp  the 2 in right ring will stay there they seem to rest on something wiring i think. just loosen and remove front plate on LD and they will fall out  maybe a little shaking involve .Only thing to watch is the wiring for the pot best to unplug it be careful i had 3 wires i had to resolder wasnt careful enough .


----------



## sgbwill2

gibosi said:


> I strongly suspect that the 6SN7's simply can't handle low Z cans all that well. I vaguely remember another poster reported an experience similar to yours, and found that a pair of 5687's were much better with his low Z cans.


 
 Yes gibosi that was me. The 5687's are far superior in sound quality in my personal opinion and don't produce any base distortion that i can hear, even with my low impedance cans such as my denon 5k's. I would recommend them Acapella11. Currently i am using 5687 GE 5 star's, these are the only ones I have tried though, eventually i would like to give some tung-sol's a go as I believe they are regarded as the best 5687's


----------



## sgbwill2

mikelap said:


> Do you have the MK3 if you do just grind of the rings youll only have 1 adapter between tube and LD and if you like the rings they sell them on ebay but these would accept your 6SN7 .Speaking of adapter having problems with my 6SN7 adapter scratchy sound but only when i touch it besides that its fine ,expecting another one on chinease pony express lol seller wants me to send broken one back at my expense rightttttttt !                                                                                                                                                                                                                                                          Musicbee is a very nice player ive had it for several years , and you can give it the look you want .                                                                                                                                                                                                                                                                                                                                    Just in case you feel like cutting something with a Dremel .Notice that i did not cut all the way thru the rings at one point they will bend and you wont have any marks on your amp  .The 2 screws in the left ring will fall in the amp  the 2 in right ring will stay there they seem to rest on something wiring i think. just loosen and remove front plate on LD and they will fall out  maybe a little shaking involve .Only thing to watch is the wiring for the pot best to unplug it be careful i had 3 wires i had to resolder wasnt careful enough .


 
 I took a less brutal approach to removing the ring on my LD MKIII, After removing both the front and back plates, removing the volume knob and unscrewing the board from the chassis, you can slide back the board (but not all the way out) allowing you to unscrew the rings with a screwdriver through the holes on the underside of the amp. I agree it is much better without the rings though. Nice to use adapters without extenders


----------



## Acapella11

mikelap said:


> Do you have the MK3 if you do just grind of the rings youll only have 1 adapter between tube and LD and if you like the rings they sell them on ebay but these would accept your 6SN7 .Speaking of adapter having problems with my 6SN7 adapter scratchy sound but only when i touch it besides that its fine ,expecting another one on chinease pony express lol seller wants me to send broken one back at my expense rightttttttt !                                                                                                                                                                                                                                                          Musicbee is a very nice player ive had it for several years , and you can give it the look you want .                                                                                                                                                                                                                                                                                                                                    Just in case you feel like cutting something with a Dremel .Notice that i did not cut all the way thru the rings at one point they will bend and you wont have any marks on your amp  .The 2 screws in the left ring will fall in the amp  the 2 in right ring will stay there they seem to rest on something wiring i think. just loosen and remove front plate on LD and they will fall out  maybe a little shaking involve .Only thing to watch is the wiring for the pot best to unplug it be careful i had 3 wires i had to resolder wasnt careful enough .


 
  
 At the moment, I am running the 6SN7 adapter with golden rings but without socket extender. It works perfectly fine. All the issues I found were related to other causes. Thank you for the tips though!
  
 Musicbee seems very nice, only one little shortcoming. For whatever reason it does not recognize my 96 kHz frequency files as 96 kHz with WASAPI with the result that it gives weak crackling noises when playing them back, like a vinyl album would. With ASIO4ALL v2, it works fine though.
  


sgbwill2 said:


> Yes gibosi that was me. The 5687's are far superior in sound quality in my personal opinion and don't produce any base distortion that i can hear, even with my low impedance cans such as my denon 5k's. I would recommend them Acapella11. Currently i am using 5687 GE 5 star's, these are the only ones I have tried though, eventually i would like to give some tung-sol's a go as I believe they are regarded as the best 5687's


 
  
 Great, 5687 it is! Thanks sgbwill2!


----------



## MIKELAP

acapella11 said:


> At the moment, I am running the 6SB7 adapter with golden rings but without socket extender. It works perfectly fine. All the issues I found were related to other causes. Thank you for the tips though!
> 
> Musicbee seems very nice, only one little shortcoming. For whatever reason it does not recognize my 96 kHz frequency files as 96 kHz with WASAPI with the result that it gives weak crackling noises when playing them back, like a vinyl album would. With ASIO4ALL v2, it works fine though.
> 
> ...


 
 I use Wasapi with my Burson Dac and all is well except  because i use Vista i cant get 88 and 176 sample rates i had to run in compatibility mode with Windows XL to get drivers  weird . it doesnt recognize all your 24/96 files you say .Did you try ASIO setting on Musicbee


----------



## MIKELAP

Was thinking in SOUND on PC is your sample rate set alright


----------



## MIKELAP

This is my Musicbee setup in preference > player


----------



## genclaymore

gibosi said:


> While I am sure the Mjolnir is a very fine amp, I am at heart more of a tinkerer and a tube roller than an audiophile, and so for me, solid state amps are boring. lol


 
 I think you mention some GE 6HM5 a few pages back, have you compared it to Mullard M8100/CV4010 and 6ZH1P-EV if you have used both.  I know my wallet is hidding under the bed but I thought about trying those GE 6HM5's out but i wanna know what to expect in compare to the tube's i have now.


----------



## gibosi

genclaymore said:


> I think you mention some GE 6HM5 a few pages back, have you compared it to Mullard M8100/CV4010 and 6ZH1P-EV if you have used both.  I know my wallet is hidding under the bed but I thought about trying those GE 6HM5's out but i wanna know what to expect in compare to the tube's i have now.


 
  
 Yes, I own all these tubes, but I haven't listened to any of them in a long time....  I can say that when I was listening to these tubes, I thought the tall-bottle GE 6HM5, manufactured in Gt Britain, was superior to both the Mullard M8100 and the Voskhod 6Zhip-EV. Also, a number of posters found the EI 6HM5, manufactured in Yugoslovia, and the US-made Sylvania to be similar. Again, you want the tall-bottles. The short bottles are nowhere near as good.
  
 And these 6HM5's are cheap. I see that the EI's are currently going for $12.50 a pair with free shipping. And since the vendor will accept offers, you might be able to get them for less.
  
 http://www.ebay.com/itm/6HM5-EC900-EI-Yugoslavia-NOS-matched-pair-Little-Dot-Amp-FREE-SHIPPING-WW-/251691711374?
  
 Set your LD for EF95 tubes, and they are plug and play.


----------



## MIKELAP

I was checking out 7N7 tubes it seems those are electrically the same as 6SN7 tubes so in the Littledot they could only be used as power tubes right with  7N7 loctal to 6CG7 adapters am i right and do they sound better  than the 6SN7.Also tempted to try them in WA6 Jac music sells the adapters and tubes are cheap .Those tubes worth it you think . Thanks.


----------



## Acapella11

mikelap said:


> Was thinking in SOUND on PC is your sample rate set alright


 

 Hi Mikelap, generic ASIO with ASIO4ALL works fine for playing 96 kHz files with Musicbee and I can use WASAPI with AIMP3 and Foobar at 96 kHz without issues. Yes, it is set to 24 Bit with 96 kHz, which is apparently the max for the M-DAC. I will try the hardware mixing but I am not inclined to do the upsampling. Thanks for coming back on this topic.


----------



## hypnos1

mikelap said:


> I was checking out 7N7 tubes it seems those are electrically the same as 6SN7 tubes so in the Littledot they could only be used as power tubes right with  7N7 loctal to 6CG7 adapters am i right and do they sound better  than the 6SN7.Also tempted to try them in WA6 Jac music sells the adapters and tubes are cheap .Those tubes worth it you think . Thanks.


 

 Hi MIKELAP.
  
 I personally preferred them to even a nice pair of VT231s, and they do get a good bit of praise from various quarters...


----------



## Acapella11

mikelap said:


> This is my Musicbee setup in preference > player


 
  
 Hi Mikelap, hardware mixing didn't do it but I can use WASAPI if I set the resampling rate to 48 kHz, resampling to 96 kHz would always produce the crackling background noises. Now, I am trying ASIO4ALL, which apparently is Kernel streaming, at 96 kHz and WASAPI resampled to 48 kHz, which in theory should be worse but doesn't appear so far worse maybe because WASAPI is superior.
  
 I have got this from the Jriver Support page, might be interesting for everyone:
  
Choosing the Audio Output Mode  On OS X MC uses Core Audio to access your audio device, which provides bit-perfect playback, and requires no configuration. On Windows, Media Center will typically choose the best Output Mode available for your device, based on the drivers installed. If given the choice between multiple modes or drivers, choose the best output for your hardware in this order:
 1) If your hardware has a native, well-behaved, ASIO driver, use ASIO.
 2) Otherwise, on Windows Vista, Windows 7, or newer, use WASAPI Exclusive Access.
 3) Otherwise, use Kernel Streaming if it works.
 4) If none of the above are possible, use DirectSound or WaveOut. Neither of these provide hardware direct output, so choose based on performance.
 If you have problems, start with DirectSound and get MC working. Once you have audio working and are comfortable using MC, then experiment with other audio output choices.
  ASIO  _See also_: ASIO
 ASIO is a sound card communication system created by Steinberg.
 If your soundcard has a native ASIO driver, this is the most direct (and normally best) way to communicate with it.
 Please note that ASIO4All is basically Kernel Streaming with an ASIO wrapper. There's no good reason to use ASIO + ASIO4All vs just using Kernel Streaming directly in Media Center.
  WASAPI (Windows Audio Session API)  _See also_: WASAPI
 WASAPI is a hardware communication system in Vista, Windows 7, and newer. When used in exclusive mode, the Windows system mixer is bypassed.
  Kernel Streaming  Kernel Streaming is a hardware direct way to speak directly to a WDM audio driver. It works on XP, so is useful when the above two options are not possible.
  Direct Sound  This is Windows default and the most compatible output method. It plays through the system mixer. This means all formats will be converted by Windows to the native format of the card. It is highly compatible, but it is not the highest quality method.
  Wave Out  This is a legacy output mode. With some misbehaved hardware, it may work better than DirectSound.
  Disk Writer  This writes whatever would have gone to the soundcard to a WAV file on disk.


----------



## gibosi

mikelap said:


> I was checking out 7N7 tubes it seems those are electrically the same as 6SN7 tubes so in the Littledot they could only be used as power tubes right with  7N7 loctal to 6CG7 adapters am i right and do they sound better  than the 6SN7.Also tempted to try them in WA6 Jac music sells the adapters and tubes are cheap .Those tubes worth it you think . Thanks.


 
  
 Electrically, they are identical to 6SN7's, but of course, they require a loctal socket instead of octal. The vast majority of 7N7s were manufactured by Sylvania, but occasionally you will find tubes manufactured by National Union. In my experience, the Sylvania's sound quite close to the short bottle 6SN7GT/A Chrome Domes. So yes, they are quite good. However, in my opinion, if you already have a pair of Chrome Domes, the 7N7s are probably not worth the extra cost of the adapters.
  
 On the other hand, if you are itching to try 7N7s, you could also try 7AF7s, which are the loctal version of the 6SL7. As a driver, I liked this tube better than the 7N7s, but can't say how it might perform as a power tube.


----------



## MIKELAP

acapella11 said:


> Hi Mikelap, hardware mixing didn't do it but I can use WASAPI if I set the resampling rate to 48 kHz, resampling to 96 kHz would always produce the crackling background noises. Now, I am trying ASIO4ALL, which apparently is Kernel streaming, at 96 kHz and WASAPI resampled to 48 kHz, which in theory should be worse but doesn't appear so far worse maybe because WASAPI is superior.
> 
> I have got this from the Jriver Support page, might be interesting for everyone:
> 
> ...


 
 In Musicbee if your Dac supports ASIO  if you choose ASIO you see configure you click on that a screen appears you see CONFIGURE again click on that  a small screen appears on there you can ajust latency  this is usually done when tune stutters maybe would help your problem


----------



## Acapella11

mikelap said:


> In Musicbee if your Dac supports ASIO  if you choose ASIO you see configure you click on that a screen appears you see CONFIGURE again click on that  a small screen appears on there you can ajust latency  this is usually done when tune stutters maybe would help your problem


 

 Hi Mikelap, thanks for the hint. With ASIO4ALL, everything works fine, even both Audiolab Bitperfect tests pass. Of course it doesn't pass with resampled WASAPI. My guess is that it is a random MDAC incompatibility issue with Musicbee, that just pops up at 96 kHz and with WASAPI.


----------



## TrollDragon

That is why we run Foobar2K, It just works.

  
 Or Fidelia if your from the other side of the tracks...


----------



## mordy

Hi Mikelap,
  
_"was checking out 7N7 tubes it seems those are electrically the same as 6SN7 tubes so in the Littledot they could only be used as power tubes_?"
  
 I have used 6SN7 tubes as driver tubes using a breadboard and Vector adapters. If you have a loctal breadboard adapter the 7N7 should work just fine (and the same goes for the 7AF7).


----------



## TrollDragon

mikelap said:


>


 
 Congrats on getting _*Headphone Supremus*_!


----------



## Acapella11

trolldragon said:


> That is why we run Foobar2K, It just works.
> 
> Or Fidelia if your from the other side of the tracks...


 
  
 Cheers Trolldragon. Foobar2k works fine but it doesn't sound as good as AIMP3 or, checking that at the moment, Musicbee.
  
 +1 for Kiss, Detroit Rock City 
	

	
	
		
		

		
		
	


	



  


trolldragon said:


> Congrats on getting _*Headphone Supremus*_!


 
  
 Congrats Mikelap!


----------



## TrollDragon

acapella11 said:


> Cheers Trolldragon. Foobar2k works fine but it doesn't sound as good as AIMP3 or, checking that at the moment, Musicbee.
> 
> 
> Congrats Mikelap!


 
  
 Won't go down that road on the *sound* of players, I followed that silliness for a while in the J River threads...
	

	
	
		
		

		
		
	


	



  
 The player should be the most transparent item in the chain unless you add features that muck with the sound. 
  
  
 Enjoy AIMP3 and MusicBee!


----------



## sgbwill2

acapella11 said:


> Cheers Trolldragon. Foobar2k works fine but it doesn't sound as good as AIMP3 or, checking that at the moment, Musicbee.
> 
> +1 for Kiss, Detroit Rock City
> 
> ...


 
 I also use AIMP3, very happy with it. great upgrade from the standard windows media player which I was previously using


----------



## Acapella11

trolldragon said:


> Won't go down that road on the *sound* of players, I followed that silliness for a while in the J River threads...
> 
> 
> 
> ...


 
  




   
 Quote:


> Enjoy AIMP3 and MusicBee!


 
  
 Cheers mate


----------



## i luvmusic 2

trolldragon said:


> That is why we run Foobar2K, It just works.


 
 +1 Foobar 2K and TEAC UD H-01 sound amazing.


----------



## Acapella11

i luvmusic 2 said:


> +1 Foobar 2K and TEAC UD H-01 sound amazing.


 

 Nice, glad you love it. Have you tried other players?


----------



## i luvmusic 2

acapella11 said:


> i luvmusic 2 said:
> 
> 
> > +1 Foobar 2K and TEAC UD H-01 sound amazing.
> ...


 
 Yes and Foobar/WASAPI is the only one that is simple enough for me to play with the others can get complicated.


----------



## Acapella11

i luvmusic 2 said:


> Yes and Foobar/WASAPI is the only one that is simple enough for me to play with the others can get complicated.


 

 Fair enough 
	

	
	
		
		

		
			





 Usability wise, Musicbee is quite good too. AIMP3 is is a bit more getting used to.
  
 Everyone has different preferences and ears. It is good there are different players out there. I think some may just not be aware what is out there.


----------



## i luvmusic 2

acapella11 said:


> i luvmusic 2 said:
> 
> 
> > Yes and Foobar/WASAPI is the only one that is simple enough for me to play with the others can get complicated.
> ...


 
 I've tried both.


----------



## MIKELAP

i luvmusic 2 said:


> Yes and Foobar/WASAPI is the only one that is simple enough for me to play with the others can get complicated.


 
 And from what i heard at that time when i was looking for a player is that Foobar was complicated ,i never tried it tought.so i saw Musicbee on this website that talked about it and i decided to try it. heres the link to that website talks about PC audio very very interesting site 
                                                                        http://www.thewelltemperedcomputer.com/


----------



## woloya

I do personally think that you just should wait a little longer
  
 ---------------------------------------------------------------------------------------------------


----------



## nsixtyfour

Hi 
	

	
	
		
		

		
		
	


	



 Would you  tell me what are your new discoveries about good (and cheap) driver tubes for the Little Dot MK2 ?
 Until now i bought only the 6j1P-EV
  
 Now I see that The 6HM5 seem apreciated for exemple.
 Have you another references to advise me?
  
 Regards,
 Aurélien


----------



## sgbwill2

Just bought a La Figaro 339, 2011 version. My dream amp  cant wait for it to arrive, interested to compare it with the LD. BTW both the 2011 and 2013 versions have 12% off them at the moment on ebay  that's why I could finally afford it lol.


----------



## gibosi

nsixtyfour said:


> Now I see that The 6HM5 seem apreciated for exemple.
> Have you another references to advise me?


 
  
 In my opinion, the 6HM5 is the best plug and play (EF95) tube available for the LD.
  
 If you are willing to do a little tube surgery, I believe the 1950's GE 6AV6 are a bit better. However, to use these it is necessary to remove pins 5 and 6 and then set your LD for EF92. The only tubes better than these are double tridoes, which will not work in the LD without a relatively complicated adapter.
  

  
 Edit: typing error - pins 5 and 6, not 6 and 7!!


----------



## bbmiller

gibosi said:


> remove pins 6 and 7


 
 Is that just a matter of two snaps with a very heavy peer diagonal cutters or is it harder than that? I mean is it hard to do without ruining the tube? How do you do it?


----------



## TrollDragon

sgbwill2 said:


> Just bought a La Figaro 339, 2011 version. My dream amp  cant wait for it to arrive, interested to compare it with the LD. BTW both the 2011 and 2013 versions have 12% off them at the moment on ebay  that's why I could finally afford it lol.


 
 Congrats!
 Very nice, it should perform Toe to Toe with MIKELAP's Woo collection.
  
 The point to point build on those looks great.


----------



## TrollDragon

bbmiller said:


> Is that just a matter of two snaps with a very heavy peer diagonal cutters or is it harder than that? I mean is it hard to do without ruining the tube? How do you do it?


 
 Dremel with a cut off disc works the best.


----------



## bbmiller

trolldragon said:


> The point to point build on those looks great.


 
 Do you think a point-to-point build is better than a printed circuit board for tube amps?


----------



## sgbwill2

trolldragon said:


> Congrats!
> Very nice, it should perform Toe to Toe with MIKELAP's Woo collection.
> 
> The point to point build on those looks great.


 
 The clean point to point internals was one of the attractive features of this amp which made me buy it. In all the reviews I have read the internals and build quality have been highly praised and allows for easy modification / replacement of parts . I am also led to believe the La Figaro 339 is in the same league as the WA2 at almost half the price, and going by the headfonia review the reviewer actually prefers the warmer sound of the La Figaro. Cant wait to try it I'm so excited  should be a nice upgrade from the LD.


----------



## gibosi

bbmiller said:


> Is that just a matter of two snaps with a very heavy peer diagonal cutters or is it harder than that? I mean is it hard to do without ruining the tube? How do you do it?


 
  
 I tried using a Dremel, but my hand just wasn't steady enough. lol. So I used a pair of flush cutters. Tube pins are relatively soft, so snipping them off flush with the glass is a simple matter.
  
  
  
 Hold the tube in your hand, upside down, and count the pins clockwise, from 1 to 7, as in the following pin diagram, and snip off pins 5 and 6. Using this technique, you can roll 6AQ6, 6AT6 and 6AV6 as EF92 tubes.


----------



## TrollDragon

bbmiller said:


> Do you think a point-to-point build is better than a printed circuit board for tube amps?


 
 Yes Indeed.
 Sgbwill2 sums it up very nicely with the ease of modification and/or parts replacement.
  


sgbwill2 said:


> The clean point to point internals was one of the attractive features of this amp which made me buy it. In all the reviews I have read the internals and build quality have been highly praised and allows for easy modification / replacement of parts . I am also led to believe the La Figaro 339 is in the same league as the WA2 at almost half the price, and going by the headfonia review the reviewer actually prefers the warmer sound of the La Figaro. Cant wait to try it I'm so excited  should be a nice upgrade from the LD.


 
  
 I could very easily get used to the 339 if it is anything like Lieven's review.
Headfonia


> OTL Amp comparisons Compared to the Bottlehead Crack, the OTL Crack is the faster amp of the two, it it clearer sounding and focuses more on the treble. Bass with the Crack is punchier but not as deep and it doesn’t quite have the same rumble. Overall the 339 is smoother, warmer and laid back with an even bigger sound stage. It just makes you feel the music better (softer) as the crack. The Crack is a great deal and an excellent amp as we already said in our review but the La Figaro 339 is the better amp for me. Compared to the Woo Audio 2, the 339 is the more tube-ish sounding amplifier with a much warmer sound. The WA2 sounds much cleaner and faster but misses the warmth and soul I like of the 339. The WA2 is more analytical as the 339 and the bass depth and rumble isn’t quite the same, however it does have an even bigger sound stage.


 
  
 Now you have different tubes to chase...


----------



## sgbwill2

trolldragon said:


> Yes Indeed.
> Sgbwill2 sums it up very nicely with the ease of modification and/or parts replacement.
> 
> 
> ...


 
 A lush warm tube sound is what I am looking for  as for tubes I knew I would eventually get a 339 so I pre purchased some tubes that came up cheap. I have a pair of RCA 6AS7's and rebranded Tung Sol 6SJ7 mesh plates already to try. Hopefully I will get myself a pair of catham/tung sol 6AS7's eventually but prices are unfortunately extremely high at the moment


----------



## i luvmusic 2

trolldragon said:


> sgbwill2 said:
> 
> 
> > Just bought a La Figaro 339, 2011 version. My dream amp  cant wait for it to arrive, interested to compare it with the LD. BTW both the 2011 and 2013 versions have 12% off them at the moment on ebay  that's why I could finally afford it lol.
> ...


 
 WOW! look at those power resistors,I would bypass some of those CAPS with film or replace some of them if there is enough room.


----------



## genclaymore

gibosi said:


> Yes, I own all these tubes, but I haven't listened to any of them in a long time....  I can say that when I was listening to these tubes, I thought the tall-bottle GE 6HM5, manufactured in Gt Britain, was superior to both the Mullard M8100 and the Voskhod 6Zhip-EV. Also, a number of posters found the EI 6HM5, manufactured in Yugoslovia, and the US-made Sylvania to be similar. Again, you want the tall-bottles. The short bottles are nowhere near as good.
> 
> And these 6HM5's are cheap. I see that the EI's are currently going for $12.50 a pair with free shipping. And since the vendor will accept offers, you might be able to get them for less.
> 
> ...


 

 If i read that right you mean the GE ,EL and Sylvania to be similar. or you meant just the EL and the Sylvania. As I found a deal with 5 GE's for 19 dollars and they are the tall ones. I tried to get the EL cheaper but the seller declined my offer.


----------



## Acapella11

trolldragon said:


> Yes Indeed.
> Sgbwill2 sums it up very nicely with the ease of modification and/or parts replacement.
> 
> I could very easily get used to the 339 if it is anything like Lieven's review.
> ...


 
 The 339 layout looks really neat. It should sound great. Hifimanrookie was posting a lot in the HE-500 thread, which I subscribed, about the Darkvoice 337/Lafigaro 339, for example here. He absolutely loved it. Based on Lieven's review, I would choose the WA2 but with the right tubes you could probably make me like it too 
	

	
	
		
		

		
		
	


	




.


----------



## gibosi

genclaymore said:


> If i read that right you mean the GE ,EL and Sylvania to be similar. or you meant just the EL and the Sylvania. As I found a deal with 5 GE's for 19 dollars and they are the tall ones. I tried to get the EL cheaper but the seller declined my offer.


 
  
 Yes, I believe the GE, EL and Sylvania 6HM5 to be quite similar. Personally, I have not heard the Sylvania and EL, but others report that these and the GE are quite similar. So my general advice is go for the cheapest ones.


----------



## MIKELAP

gibosi said:


> I tried using a Dremel, but my hand just wasn't steady enough. lol. So I used a pair of flush cutters. Tube pins are relatively soft, so snipping them off flush with the glass is a simple matter.
> 
> 
> 
> Hold the tube in your hand, upside down, and count the pins clockwise, from 1 to 7, as in the following pin diagram, and snip off pins 5 and 6. Using this technique, you can roll 6AQ6, 6AT6 and 6AV6 as EF92 tubes.


 
  Here's a picture of which pins to cut off


----------



## MIKELAP

trolldragon said:


> Congrats!
> Very nice, it should perform Toe to Toe with MIKELAP's Woo collection.
> 
> The point to point build on those looks great.


 
 The inside is really nice alot nicer than the Woo  very clean .  But there's one thing TD what you cant see cant hurt you .Damm i just saw it lol .But there's an upside to everything .Ahhhhh!


----------



## TrollDragon

mikelap said:


>


 
 Those CMC sockets are very nice! The Woo is also a great build!


----------



## bbmiller

Thanks gibosi and MIKELAP the picture of those flush cutters convinced me that those were far superior to any tool I have now for cutting tube pins. And that other picture will be very reassuring should and when I decide to cut tube pins.

  I did find searching by picture to find where you buy those a little challenging though. I had to resort turn in the picture on its side and reading the labeling exactly to find them on eBay.
The eBay link if anybody else is interested is here with a price of only US $6.78.


----------



## sgbwill2

mikelap said:


> The inside is really nice alot nicer than the Woo  very clean .  But there's one thing TD what you cant see cant hurt you .Damm i just saw it lol .But there's an upside to everything .Ahhhhh!
> 
> 
> Still very neat inside compared to the likes of the LD range haha. I would love to compare both the WA2 and LF 339 side by side some day. Maybe when I'm older and have more money in my pocket it may be possible  So excited for the LF to arrive. Now the long wait for it from Hong Kong!


----------



## mordy

If you do not have a flush cutter to cut off the tube pins, a small regular cutting pliers will do fine. The tiny pieces left can be covered with small pieces of electrical tape. Do not try to bend the pins to get them off because it may cause the glass to crack.


----------



## mordy

Just wanted to correct a little typo: You won't find what you want by searching for EL tubes - the correct name is Ei. I think the name means something like Electronic Industry in the Yugoslav language.
  
 PS: Oskari, was it Phillips or Philips?


----------



## Oskari

mordy said:


> PS: Oskari, was it Phillips or Philips?


 
  


oskari said:


>


----------



## TrollDragon




----------



## genclaymore

gibosi said:


> Yes, I believe the GE, EL and Sylvania 6HM5 to be quite similar. Personally, I have not heard the Sylvania and EL, but others report that these and the GE are quite similar. So my general advice is go for the cheapest ones.


 
 I end up buying the EI's just gotta wait for the seller to ships them. Since they came out cheaper, glad I did as as soon after i bought them, he raised the price by 4 dollars. so I paid $12 Right in time.


----------



## mordy

So there I was, trying to install the Voshkod and Phillips tubes with my Philips screwdriver when I was interrupted by a tube roller using a vacuum tube....
  





  




  
 And to round out the wacky images - a trio of lady tubes:


----------



## Acapella11

mordy said:


> So there I was, trying to install the Voshkod and Phillips tubes with my Philips screwdriver when I was interrupted by a tube roller using a vacuum tube....
> 
> 
> 
> ...


----------



## Acapella11

Received a pair of Sylvania brown base 6SN7WGT tubes. Besides, the HE-500 problem still exists, when using them as power tubes, they sound really nice with the HD800s (+ C3GS). The cosmetic disadvantage is that with the large chrome cap of the Sylvanias, I hardly see any tube glow, lol. More after some more listening...


----------



## mordy

Hi,
  
 Still trying to do something about the hum from my PC sound card. I have a little USB DAC, but when I plug it in there is no sound coming out from the audio jack. Should I disable the Realtek Audio that the PC comes with?
  
 Something else I can do to activate the USB DAC?


----------



## sgbwill2

mordy said:


> Hi,
> 
> Still trying to do something about the hum from my PC sound card. I have a little USB DAC, but when I plug it in there is no sound coming out from the audio jack. Should I disable the Realtek Audio that the PC comes with?
> 
> Something else I can do to activate the USB DAC?


 
 I had some initial issues with my topping d20 DAC and connecting it with my laptop. If I remember correctly I believe I went into audio devices and found the DAC and set it as the main device/default and that allowed it to work. Hope this helps.


----------



## mordy

USB DAC set as main device but nothing happens. To the left of the box is a bar graph that shows sound output - it only works for Speakers and not for DAC. I am not able to click on the Apply button - maybe that's the problem.


----------



## sgbwill2

I have no idea then =/ maybe go on devices and printers and see if your device is there and maybe try changing some settings update drivers etc. Have u tried it out of other USB ports? just in case that port is dodgy.


----------



## MIKELAP

mordy said:


> USB DAC set as main device but nothing happens. To the left of the box is a bar graph that shows sound output - it only works for Speakers and not for DAC. I am not able to click on the Apply button - maybe that's the problem.


 
 Your using vista right what player are you using ,ill try and explain i have a bose desktop setup and my dac setup for my amps both are activated .When i point to speaker icon i see the bose setup but when i open Musicbee it might show the bose setup or it might show the dac setup depending if i listened to utube or something else .So in order to listen to my amps via dac i need to activate the dac in PREFERENCE >PLAYER  in my case its burson conductors dac and my usb interface works with wasapi once thats changed i APPLY changes and all is well . If you had photo capture of the screens it would be simpler.


----------



## mordy

Problem solved.
  
 Found a site that said that some Windows OS cannot switch to a DAC from the Win audio output while a music browser is running. I shut off the Musicbee, and then turned it on again. It worked! The output goes through my DAC now.
  
 I think Gibosi told me about this little DAC a couple of years ago.
  




  
 Anyhow, this is what I have on hand. My objective was to find out if I could decrease the hum from my PC by using an external DAC.
  
 So how did my experiment go? The answer is that the hum is somewhat lower with this device but it is still noticeably there. My laptop, chromebook and CD player make much less hum, down to a tolerable level.
  
 In conclusion only a slight improvement and not meeting my objectives. Now I just have to figure out if the sound from the DAC is better than the built in Win sound card....And I better not trip on that wire connecting the DAC across the floor in my room!


----------



## mordy

Hi Mikelap,
  
 I am using Musicbee, but all those abbreviations and screens leave me confused. I can access a manual for Musicbee and maybe try to figure it out, but I am totally unfamiliar with all the different stuff with the strange names.
  
 ASIO, ASIO4ALL, WASAPI, AIMP3 and Foobar - don't know what these mean. Hey, if I can learn what the difference is between a C3m and a C3o I could pick this up too! (If you can tell what the difference is you get a honorable mention LOL.)


----------



## Acapella11

mordy said:


> Hi Mikelap,
> 
> I am using Musicbee, but all those abbreviations and screens leave me confused. I can access a manual for Musicbee and maybe try to figure it out, but I am totally unfamiliar with all the different stuff with the strange names.
> 
> ASIO, ASIO4ALL, WASAPI, AIMP3 and Foobar - don't know what these mean. Hey, if I can learn what the difference is between a C3m and a C3o I could pick this up too! (If you can tell what the difference is you get a honorable mention LOL.)


 
  
 OK, I am not addressed, but I may still help I guess. ASIO is a direct software interface from your player to your dac. It circumvents besides others the windows equalizer. THe proper ASIO only works if your hardware manufacturer delivers a specific driver for ASIO. If that is not the case, you can download ASIO4ALL (http://www.asio4all.com/), which works well for me. It is not as ideal as perfect hardware ASIO, but still good. WASAPI is the Windows (since Vista) own audiophile software interface. It comes just after manufacturer's ASIO in priority.
  
 You can find the settings for Musicbee in Edit -> Preferences -> Player.
  
 AIMP3 and Foobar are alternative players to Musicbee.
  
 Enjoy!


----------



## MIKELAP

mordy said:


> Hi Mikelap,
> 
> I am using Musicbee, but all those abbreviations and screens leave me confused. I can access a manual for Musicbee and maybe try to figure it out, but I am totally unfamiliar with all the different stuff with the strange names.
> 
> ASIO, ASIO4ALL, WASAPI, AIMP3 and Foobar - don't know what these mean. Hey, if I can learn what the difference is between a C3m and a C3o I could pick this up too! (If you can tell what the difference is you get a honorable mention LOL.)


 
 All you need to know his here            http://www.thewelltemperedcomputer.com/


----------



## Oskari




----------



## i luvmusic 2

mikelap said:


> trolldragon said:
> 
> 
> > Congrats!
> ...


 
  Both inner guts make me drool I'am a sucker for P2P wiring i really like them they are pretty to look at and easy to mod depending on chassis/case size.


----------



## bbmiller

Hello
  If you look at the pinouts of the stock 6H30PI power tube (for a little dot MK IV amplifier) and the 12ax7eh they look identical except that the 12ax7eh has a wire going to pin nine of the tube which is said to make it a  6V or  12 V heater tube. But I do not know if my little dot MK IV amplifier comes with that pin already grounded to let you use this type of 12 vote tube. So does the little dot MK IV amplifier come with this pin already grounded so that this tube would become a plug-and-play power tube. If it doesn't how hard would this be to do?
  
A Pinouts for the 6H30PI can be found here.
  
A pinouts for the 12ax7eh can be found here.
  
In the head FI The Reference 6SN7 Thread the review I am posting below sounds excellent.
 Quote


> *NEW STOCK – Electro-Harmonix EH6SN7** [PHOTO HERE]*
> _[black plates, black base, black labels on glass, top getter]_
> ● “The Electro Harmonix were the most dynamic in the MPX3 . The Bass is also the best and biggest of the three; quite detailed and tight. Midrange is also full of detail air and transparency up and down the range. Gets a little too bright in my system at times, but generally the most fun and involving tubes to listen to so far for me.” –bobjew
> ● “With the Electro Harmonix 6SN7's in current production, there is no need to suffer.” –Hirsch
> ...


 
 So does all that boil down to an almost identical sounding tube to the the stock little dot  IV MK SE  power tube? Has anybody heard  this tube? If I like the stock power tube will I like this tube and it's much cheaper price?
  
 PS whoops I now realize what I did when I reviewed the post I just posted. I posted what is said, but about the octal version of this tube but I was looking at the nine pin mini package version when I got enthused about what could be a cheaper version of the stock power tube on eBay. Well perhaps you can tell me what you think of both I also have a pair of octal adapters just sitting there ready to use should I have to.
  
 OK I finally think I'm getting my reviews straight between the mini nine pin version and the octal's. They seem to like the mini nine pin version@Amazon.com. Reviews to numerous to post, but here is the link. It is said to be a black Friday deal and as of this moment it is black Friday.


----------



## gibosi

bbmiller said:


> Hello
> If you look at the pinouts of the stock 6H30PI power tube (for a little dot MK IV amplifier) and the 12ax7eh they look identical except that the 12ax7eh has a wire going to pin nine of the tube which is said to make it a  6V or  12 V heater tube. But I do not know if my little dot MK IV amplifier comes with that pin already grounded to let you use this type of 12 vote tube. So does the little dot MK IV amplifier come with this pin already grounded so that this tube would become a plug-and-play power tube. If it doesn't how hard would this be to do?


 
  
 In short, no, you cannot simply plug 12AX7's into your LD. Pin 9 on the 6H30PI is connected to an electrostatic shield. Pin 9 on the 12AX7 is connected to the heater circuit. And thus, in your LD power tube sockets, the heaters are connected to pins 4 and 5. In order to run a 12AX7 at 6V, it is necessary to tie pins 4 and 5 together, and then connect the heaters to pin 4 (or pin 5) and pin 9.
  
 But there is no reason for despair... There are adapters! 
  
 For example:
  
 http://www.ebay.com/itm/Two-adapters-for-12AU7-ECC82-to-instead-6CG7-6AQ8-ECC88-TUBES-amplifier-/261667818185?
  
 When searching for adapters, it is important to remember that 12AU7, 12AT7 and 12AX7 all have the same pin-out. And likewise, 6CG7, 6AQ8, ECC85, 6DJ8, ECC88, 6N23P, 6N1P and 6H30PI all have the same pinout.
  
 That said, the 12AX7, drawing only 0.3A, is probably not a good candidate for a power tube. But with high Z cans, it might not be all that bad....


----------



## MIKELAP

Would any of you guys have the 2 letter date codes used  for RCA tubes in mid 50's and again in the mid 60's. Thanks .


----------



## MIKELAP

Gibosi you had a link to RCA  date codes post # 2587 page 173 but link is not active anymore do you still have those date codes.Thanks.


----------



## gibosi

mikelap said:


> Would any of you guys have the 2 letter date codes used  for RCA tubes in mid 50's and again in the mid 60's. Thanks .


 
  
 http://pax-comm.com/rcadates.pdf
  
 Evidently, it is possible to date RCA tubes by looking at the etched octagram and noting where there are breaks in the lines. I have noticed these breaks, but to my knowledge, the "key" to this coding is not available on the internet.
  
 So it appears that the best we can do is determine the date of shipment. So for example, I have a RCA 6FW8, which is a plug-in replacement for a 6DJ8/ECC88. The two-letter code is "LS". Looking at the table on the third page (actually page #18) I see that my tube was shipped in March, 1960. So while I don't know the precise date of manufacture, it was sometime before that shipment date, perhaps a few weeks or months.
  
 edit: typo


----------



## gibosi

A nice Telefunken 6463 arrived in today's mail and I am pleased to say that it lights up and plays 
  

  
 And I wonder if anyone else is running 6350, 6463 or ECC813 tubes? Again, if you have a breadboard socket, it is easy to reconfigure it for these tubes. As I have recently gone back to school to get started in a new career, I haven't been able to spend much time listening to my system. But I can say that the Sylvania 6350's are terrific tubes, and I have high hopes for this Telefunken.


----------



## siles1991

I want to kick my MKIV SE up a notch and I have no idea how after being out of the scene for so long T.T. Would the 6HM5's be better than my current RCA 6DT6A and Valvo's?
 Or should I just go for the C3gS's with adapters?


----------



## gibosi

siles1991 said:


> I want to kick my MKIV SE up a notch and I have no idea how after being out of the scene for so long T.T. Would the 6HM5's be better than my current RCA 6DT6A and Valvo's?
> Or should I just go for the C3gS's with adapters?


 
  
 It really depends on how much you are willing to spend? A pair of 6HM5's are dirt cheap, and in my opinion, better than the 6DT6. But a pair of C3g's sound significantly better, arguably end-game as far as drivers go. So again, it really depends on how much you are willing to spend? Perhaps $15 for a pair of 6HM5? or $130 for Cg3?
  
 http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/6000#post_10512665
  
 Evidently, adapters are no longer available from "happydiy998", but I see that"tubemalls" has them for a better price. I have purchased other adapters from this vendor in the past and so expect these C3g adapters to be fine.
  
 http://www.ebay.com/itm/2piece-Gold-plated-C3G-TO-6AK5-tube-converter-adapter-/191424601510?


----------



## MIKELAP

siles1991 said:


> I want to kick my MKIV SE up a notch and I have no idea how after being out of the scene for so long T.T. Would the 6HM5's be better than my current RCA 6DT6A and Valvo's?
> Or should I just go for the C3gS's with adapters?


 
 I 've been using the C3GS as drivers and the 6SN7with adapters as power tubes and i would say it the best sound i've  gotten out of this amp(MK3) yet .Electro Harmonix 6H30pi sound good to But if you get into C3GS they tend to be fragile when inserting in adapters so NO WIGGLING the tube when inserting or removing it might break the glass around the pins .


----------



## siles1991

gibosi said:


> It really depends on how much you are willing to spend? A pair of 6HM5's are dirt cheap, and in my opinion, better than the 6DT6. But a pair of C3g's sound significantly better, arguably end-game as far as drivers go. So again, it really depends on how much you are willing to spend? Perhaps $15 for a pair of 6HM5? or $130 for Cg3?
> 
> http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/6000#post_10512665
> 
> ...


 
  
  


mikelap said:


> I 've been using the C3GS as drivers and the 6SN7with adapters as power tubes and i would say it the best sound i've  gotten out of this amp(MK3) yet .Electro Harmonix 6H30pi sound good to But if you get into C3GS they tend to be fragile when inserting in adapters so NO WIGGLING the tube when inserting or removing it might break the glass around the pins .


 
  
 I want something end-game so i'll prolly go straight for the CG3's. Thanks for the links ^_^ Power tubes i'll prolly wait till mine dies out haha. Im using the MKIV SE will I need the additional adapter on top of the adapter to fit it in?


----------



## MIKELAP

siles1991 said:


> I want something end-game so i'll prolly go straight for the CG3's. Thanks for the links ^_^ Power tubes i'll prolly wait till mine dies out haha. Im using the MKIV SE will I need the additional adapter on top of the adapter to fit it in?


 
  


siles1991 said:


> I want something end-game so i'll prolly go straight for the CG3's. Thanks for the links ^_^ Power tubes i'll prolly wait till mine dies out haha. Im using the MKIV SE will I need the additional adapter on top of the adapter to fit it in?


 
 You can remove your tube cages on MK4


----------



## Acapella11

siles1991 said:


> I want to kick my MKIV SE up a notch and I have no idea how after being out of the scene for so long T.T. Would the 6HM5's be better than my current RCA 6DT6A and Valvo's?
> Or should I just go for the C3gS's with adapters?


 
 Mikelap and Gibosi beat me to it


----------



## hypnos1

siles1991 said:


> I want something end-game so i'll prolly go straight for the CG3's. Thanks for the links ^_^ Power tubes i'll prolly wait till mine dies out haha. Im using the MKIV SE will I need the additional adapter on top of the adapter to fit it in?


 
  
 Hi s1991.
  
 Yes...end-game indeed IMHO...
  
 As MIKELAP says, you can just remove the 'cages'...and the plate, of course...
  
 And you are VERY lucky that gibosi has found that new source for the adapters!...
  
 Again, as MIKELAP says, you must be EXTREMELY careful inserting the tubes into the adapter...if they won't go in fairly easily with a STRAIGHT push, loosen the socket hole connectors - I found a good method was to use a small 1.5mm screwdriver (as in those spectacle repair kits) to prise them open a bit more. Just work it in and out until it inserts without too much effort, and you should then be safe...I would hate for you also to lose big $$$$$$ -  as a few of us have already!
  
 Then...ENJOY!!


----------



## hypnos1

gibosi said:


> It really depends on how much you are willing to spend? A pair of 6HM5's are dirt cheap, and in my opinion, better than the 6DT6. But a pair of C3g's sound significantly better, arguably end-game as far as drivers go. So again, it really depends on how much you are willing to spend? Perhaps $15 for a pair of 6HM5? or $130 for Cg3?
> 
> http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/6000#post_10512665
> 
> ...


 
  
 Hey g...WELL FOUND!...Those adapters look MUCH better - AND cheaper....GENIUS!


----------



## superdux

still have some C3G for a bargain price if anyone is interested.


----------



## bbmiller

mikelap said:


> You can remove your tube cages on MK4


 
 The easiest way to do this is to unscrew the two black screws you find between the power and driver tubes and not disassemble the cages. Unscrewing the two black screws lets all the bronze lift in one piece removing the cages from both power and drivers and the rest of the bronze to. You may not even have to remove your tubes first. Then put back those screws for safekeeping. That's the best way to do that.


----------



## mordy

Hi siles 1991,
  
 Agree with above about the C3g as drivers. However, having tried both the 6SN7 tubes and the 6AS7/6080 tubes as power tubes I found the 6AS7/6080 tubes superior. There is more of everything, especially bass impact and slam.
  
 IMHO approaching end game performance for the LD would include the 2.5A power tubes mentioned. Especially the 6080 are easy to find and not expensive. However, these tubes draw more current than the LD can handle, and require an external power source. In order to make it all work you need octal to 9pin adapters plus socket extenders so that the heaters can be wired to the external power source.
  
 All this is described in detail on this forum and is less complicated than it sounds.


----------



## mordy

Hi A11 and Mikelap,
  
 Thanks for your input - very helpful. A11, anybody on this forum is always invited to answer questions - thanks for the clarification of the terms. Will need more time to digest the article Mikelap sent the link for.
  
 Anyhow, what's the difference between C3m and C3o tubes? And STC 5A152M?


----------



## i luvmusic 2

superdux said:


> still have some C3G for a bargain price if anyone is interested.


 
 How much are you asking per tube?with a good price i will take four.
  
 THANKS!


----------



## superdux

hi wrote you a message.This is my last batch C3G tubes, first come first serve: there would probably be 2 left if the folks who asked are buying.


----------



## i luvmusic 2

I guess i will be joining you guys with your C3g journey.
	

	
	
		
		

		
			




 All i need now is to find a good Loctal sockets(not adapter socket only).
 Can anyone please send me a link where i can get one.
 THANK YOU!
  
 Thanks to superdux!


----------



## i luvmusic 2

> i bought these yesterday they look better maybe more forgiving when inserting tube  compare to other  picture


 
 Hey Mike!
   May i asked where did you get those sockets?


----------



## MIKELAP

i luvmusic 2 said:


> Hey Mike!
> May i asked where did you get those sockets?


 
 Got those from Russia still waiting for them by the way .Just checked wanted to give you the link but guy is soldout but theres some here in your neighborhood but there expensive i offered him $5.00 never got a response lol. 
                                                                      
 http://www.ebay.com/itm/151491140665?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT


----------



## i luvmusic 2

mikelap said:


> i luvmusic 2 said:
> 
> 
> > Hey Mike!
> ...


 
 Yeah i know i offered $6 and was declined.
 THANK YOU!


----------



## i luvmusic 2

Anyone have used one of those made in Chinada loctal sockets for your DIY adapters for C3g's? THANKS!


----------



## Acapella11

superdux said:


> hi wrote you a message.This is my last batch C3G tubes, first come first serve: there would probably be 2 left if the folks who asked are buying.


 
 Get a few more of these C3G deals! 
	

	
	
		
		

		
		
	


	




 I am sure you will be able to sell them and everyone will have the chance to try the excellent sound. 
	

	
	
		
		

		
		
	


	




 Thanks for putting your effort into this.
  
 Quick question: Wouldn't be the combination of 6SN7 as driver and C3G as power tubes workable?


----------



## superdux

I would surely do, but this was just a one time deal but at least it brought the C3G tube to a wider audience with not such a steep price tag.


----------



## MIKELAP

i luvmusic 2 said:


> Anyone have used one of those made in Chinada loctal sockets for your DIY adapters for C3g's? THANKS!


 
 I could accomodate you


----------



## siles1991

I'll be trying the c3g's first short on funds to hit all the way to the end atm. Shipping to Malaysia aint cheap.


----------



## gibosi

acapella11 said:


> Quick question: Wouldn't be the combination of 6SN7 as driver and C3G as power tubes workable?


 
  
 The problem is the stock LD power tubes are double triodes, and the C3g is a single triode-strapped pentode, so it is not as simple as using a 6NS7 or a 5687. However, it is my understanding that it could be done, if the LD has the two halves of the 6H30P configured in series, one driving the other. Hook the grid of the C3g to the pin corresponding to the grid of the first half of the 6H30P, pin 7, and the plate and cathode of the C3g to the plate and cathode of the second half, pins 1 and 3. Connect the heaters to pins 4 and 5, and leave the other pins in the socket disconnected. This assumes you have already done the strapping necessary to convert the Cg3 into a triode. And it just might work.


----------



## ToTje

I just ordered 2 sets of 6J1P-EV (EF95 6F32 6AK7) VHF pentode tubes with gold-Platinum grid! 
	

	
	
		
		

		
			




  
 Do I need to change something in my Little Dot, or can these replace the current RTC 5654RT's without problems?


----------



## gibosi

totje said:


> I just ordered 2 sets of 6J1P-EV (EF95 6F32 6AK7) VHF pentode tubes with gold-Platinum grid!
> 
> 
> 
> ...


 
  
 Nothing different needs to be done. Pull the RTC's out and plug the Voskhods in.
  
 Cheers


----------



## ToTje

gibosi said:


> Nothing different needs to be done. Pull the RTC's out and plug the Voskhods in.
> 
> Cheers


 
 Great, thanks! 
	

	
	
		
		

		
		
	


	



 $3 a pair, but a friend told me they sound awesome, so I guess it's worth a try.


----------



## i luvmusic 2

mikelap said:


> i luvmusic 2 said:
> 
> 
> > Anyone have used one of those made in Chinada loctal sockets for your DIY adapters for C3g's? THANKS!
> ...


 
 Sure why not......


----------



## Acapella11

gibosi said:


> The problem is the stock LD power tubes are double triodes, and the C3g is a single triode-strapped pentode, so it is not as simple as using a 6NS7 or a 5687. However, it is my understanding that it could be done, if the LD has the two halves of the 6H30P configured in series, one driving the other. Hook the grid of the C3g to the pin corresponding to the grid of the first half of the 6H30P, pin 7, and the plate and cathode of the C3g to the plate and cathode of the second half, pins 1 and 3. Connect the heaters to pins 4 and 5, and leave the other pins in the socket disconnected. This assumes you have already done the strapping necessary to convert the Cg3 into a triode. And it just might work.


 
  
 Thanks Gibosi, what would we do without you  It would be a new experimental adapter. This could possibly be a Xmas project after a communication Mr ZheZhe


----------



## Johnnysound

While I wait for the 6HM5s to arrive  (and soon C3 gs ¡) I received some nice old  6SN7s, and yes, they are a step above the stock 6N6Ps.    I used the TS 6485s to test the powers,   my current favorite,  along with the Sylvania JHS 6AH6.  Both tubes are 6AH6 variants,  but they do sound different.  The TSs are a bit more detailed,   and the Sylvanias have deeper bass.  
  
 Tung-Sol  6485s, early sixties I think
  

  
  
 Very nice sounding Nos Sylvanias.   Note the mil-spec black coating... 
  

  
  
 Just for comparison, Soviet  6J5Ps, which is a copy of the U.S. 6485. This particular pair from an extint Ukranian factory I think.  Nice looking, but awful sounding IMHO.  These tubes were NOT made for audio.    However, you never know, probably Svetlana "winged C" 6J5Ps will sound very good...quality varies a lot from different Soviet factories and years of production. 
  

  
  
 In contrast, the 6SN7GT Tungsrams (photo from an ad) are excellent tubes, obviously Soviet made and rebranded.  Mine look older than these, and are probably late fifties/early sixties Foton factory.  
  
  

  
  
  
  
 Trio of CBS Hytrons, 1954.   Classic tube sound with detail, warmth, ambience and  very deep bass. Outstanding tubes.  For me, the Soviet Tungsrams sounded  very close,  and I wonder if the similar "T" plate construction has to do something with this.  
  
  
    
  
  
  
 Quad ITT Japan 6SN7GTB, parallel black plates, top "O" getter.  The least "tubey"  sounding of the three, or maybe more "modern" sounding.   Not  particularly warm or romantic, but very detailed with tight bass impact and dynamics, like good solid state.   Best sounding tube with my speakers,  that are a little "bass heavy" so its tight bass make a good combination.


----------



## Acapella11

Couldn't resist to make a non-tube upgrade to improve my tube (and ss-) sound:
  

  
 This is an Power Inspired AG500 power re-generator. It is specced for 500 W and includes batteries to run the system in case of a loss of power for a short time. It converts AC to DC and DC back to AC. Six devices can be connected via female IEC connectors at the back, to which I connected adapters (IEC male to power socket). The unit is active but this model allows to set the fan speed manually and in my ears it is very very quiet at say about 75 % of the max fan speed.
This is a flowchart from the software included. It shows current stats of the power regeneration and as you can see the load is 0 %. That is with 2 amps and one DAC connected and running. I needed a power hungry lamp on top to trigger a load of 25 %.
  
 The cleaner power has a positive effect on my Little dot and Questyle amps. The stage gets deeper and develops more volume. More details are revealed, I really discovered a lot more microdetails with the AG500 connected. The sound becomes less "shrieking" and more refined. Overall, it quite adds to the SQ. I recommend it. The, still reasonably quiet, version without fan control comes for £299, the one with for £349. Considering, you can use this unit throughout all your upgrades and gear, it is a reasonable price and if you compare it to the prices of other re-generator units, this is actually a bargain.
 If you want to know more, here is a proper review: http://headmania.org/2013/09/02/power-inspired-ag500-power-regenerator-review/


----------



## i luvmusic 2

Dumbest thing i've done when it comes to power,I took a CAR Battery and used my 12A regulator to power-up my 6AS7G's for the MK III it works and have a very quiet/clean background and deeper bass this i like but car batteries are ugly and heavy.


----------



## sgbwill2

Nice, sounds interesting. Wish I could listen to one. One of the drawbacks to living in the countryside in Wales is there are no audio stores to speak of within 100 miles. Though speaking of upgrades a present arrived via DHL today


----------



## i luvmusic 2

sgbwill2 said:


> Nice, sounds interesting. Wish I could listen to one. One of the drawbacks to living in the countryside in Wales is there are no audio stores to speak of within 100 miles. Though speaking of upgrades a present arrived via DHL today


 
 Congrats and enjoy!


----------



## sgbwill2

i luvmusic 2 said:


> Congrats and enjoy!


 
 Thanks  I'm enjoying it very much. Listening through it at this moment using RCA 6AS7's and Japanese 6SJ7 mesh plates. Cant wait to get my hands on the Tung Sol mesh plates and the Bendix 6080wb graphite plates as they are supposed to be the best combo with this amp.


----------



## Acapella11

i luvmusic 2 said:


> Dumbest thing i've done when it comes to power,I took a CAR Battery and used my 12A regulator to power-up my 6AS7G's for the MK III it works and have a very quiet/clean background and deeper bass this i like but car batteries are ugly and heavy.


 
  
 Brilliant though!


----------



## i luvmusic 2

sgbwill2 said:


> i luvmusic 2 said:
> 
> 
> > Congrats and enjoy!
> ...


 
 Bendix 6080wb graphite plates i've look at those tubes before i build my CRACK amp and i nearly schiit on my pants when i saw how much they go for.


----------



## sgbwill2

i luvmusic 2 said:


> Bendix 6080wb graphite plates i've look at those tubes before i build my CRACK amp and i nearly schiit on my pants when i saw how much they go for.


 
 The price is crazy. I just hope that I get lucky and pick up a pair cheap. The Tung sol 5998's are also supposedly very nice but unfortunately they are also ridiculously priced
(


----------



## i luvmusic 2

acapella11 said:


> i luvmusic 2 said:
> 
> 
> > Dumbest thing i've done when it comes to power,I took a CAR Battery and used my 12A regulator to power-up my 6AS7G's for the MK III it works and have a very quiet/clean background and deeper bass this i like but car batteries are ugly and heavy.
> ...


 
 This is to proved that CLEAN POWER is good for Tube amps i don't know if SS amp will be the same.


----------



## i luvmusic 2

sgbwill2 said:


> i luvmusic 2 said:
> 
> 
> > Bendix 6080wb graphite plates i've look at those tubes before i build my CRACK amp and i nearly schiit on my pants when i saw how much they go for.
> ...


 
 I wanted those tubes for my crack but did not pull the trigger instead i got my self a SEX amp.Good Luck!


----------



## mordy

Hi I love music 2,
  
 How many amps does your car battery carry [cold cranking amps LOL]? It's a neat idea though. How does it compare to a good PC power supply?
  
 At this point my hum level has been lowered quite a lot by using a Win7 laptop with the little outboard DAC. There is now no hum at loud levels, but I still get it when I turn the volume all the way up, but I couldn't listen to such loud levels. (Testing the system without playing music)
  
 Years ago I bought an AC power line conditioner that helps to lower RF and EMI noise, and most of my equipment is plugged into it. Reminds me that I have an isolation transformer lying around - gonna find it and try it again.


----------



## i luvmusic 2

mordy said:


> Hi I love music 2,
> 
> How many amps does your car battery carry [cold cranking amps LOL]? It's a neat idea though. How does it compare to a good PC power supply?
> 
> ...


 
 Plenty enough to weld some metals if you short them
 Very CLEAN SOUNDING NO HUM/NOISE  very quiet background.


----------



## i luvmusic 2

Note:
 I did the car battery thingy while it is not installed in the car.


----------



## i luvmusic 2

Please don't bring your CAR inside your house just to power-up your LD amp tubes.


----------



## Acapella11

i luvmusic 2 said:


> This is to proved that CLEAN POWER is good for Tube amps i don't know if SS amp will be the same.


 
  
 Yes, also, quantity depends on quality of the power supply and built in power filters, generally.


----------



## i luvmusic 2

acapella11 said:


> i luvmusic 2 said:
> 
> 
> > This is to proved that CLEAN POWER is good for Tube amps i don't know if SS amp will be the same.
> ...


 
 So i guess having a really good power supply is a good start if you are building your own amp but that is probably expensive.


----------



## i luvmusic 2

I forgot to mention my setup for the car battery test was Sylvania Chrome top 2 6SN7 GTB for the power and 1 Chatham 6AS7G for the driver this setup have a slight hum when i have it plug-in to my Desktop PS but with the CAR BATTERY very quiet.


----------



## MIKELAP

sgbwill2 said:


> i luvmusic 2 said:
> 
> 
> > Congrats and enjoy!
> ...


 
 If im not mistaken the 5693 reds are suppose to be good with this amp


----------



## MIKELAP

i luvmusic 2 said:


> Please don't bring your CAR inside your house just to power-up your LD amp tubes.


 
 Good advice ,use cables lol


----------



## TrollDragon

sgbwill2 said:


> Nice, sounds interesting. Wish I could listen to one. One of the drawbacks to living in the countryside in Wales is there are no audio stores to speak of within 100 miles. Though speaking of upgrades a present arrived via DHL today


 
 Congrats!


----------



## sgbwill2

mikelap said:


> If im not mistaken the 5693 reds are suppose to be good with this amp


 
 Yes, they are supposed to be a very warm sounding tube but the mesh plates extend the soundstage and add more detail I believe from what I have read. I will most likely end up getting both


----------



## sgbwill2

trolldragon said:


> Congrats!


 
 Thanks  I will post some photos of my setup later now it is all set up.


----------



## sgbwill2

Some pictures of the La Figaro


----------



## Acapella11

Totally love the HE-500 with my 1983 6H30P-DR and C3GS tubes. Hope the 5687 tubes I have ordered come any close to that.
 Besides this, I found that with the HD800, my Sylvania 6SN7WGT brown base tubes have a similar signature to the 6H30P-DRs.


----------



## sgbwill2

acapella11 said:


> Totally love the HE-500 with my 1983 6H30P-DR and C3GS tubes. Hope the 5687 tubes I have ordered come any close to that.
> Besides this, I found that with the HD800, my Sylvania 6SN7WGT brown base tubes have a similar signature to the 6H30P-DRs.


 
 I found the 5687's to be better than any 6sn7/6f8g tubes that I tried. Hope you like them as much as I do


----------



## MIKELAP

sgbwill2 said:


> acapella11 said:
> 
> 
> > Totally love the HE-500 with my 1983 6H30P-DR and C3GS tubes. Hope the 5687 tubes I have ordered come any close to that.
> ...


 
 Are the 5687's  plug n play as power tubes


----------



## sgbwill2

mikelap said:


> Are the 5687's  plug n play as power tubes


 
 Nope you need adapters as they are 12.6v tubes but can also run in 6.3v. I bought these and they work fine:
  
 http://www.ebay.co.uk/itm/1x-5687-to-6N6-6922-6N11-ECC88-6DJ8-Vacuum-tube-adapter-socket-converter-/291131310065?pt=UK_AudioTVElectronics_HomeAudioHiFi_Amplifiers&hash=item43c8c73ff1


----------



## MIKELAP

I know this tube can be used as a driver so  is it possible or not to use only one tube as driver in the copper 6DJ8 adapter or the 12ax7 adapter i made awhile back .Thanks


----------



## sgbwill2

The 5687 is very similar to 12ax7 I believe but it draws up 3 times as much (0.9A in 6.3v setup compared to 0.3A with 12ax7). It should in theory work in the 12ax7 adapter but I am unsure whether it would strain the amp too much being used as drivers. As for being used as power tubes they are fine without external heaters.


----------



## gibosi

mikelap said:


> I know this tube can be used as a driver so  is it possible or not to use only one tube as driver in the copper 6DJ8 adapter or the 12ax7 adapter i made awhile back .Thanks


 
  
 As sgbwill2 wrote, with an adapter it could be used in one of your copper adapters. However, you would need to find a way to power the heaters with an external heater power supply. As best we can tell, the LD can safely provide up to 0.45A, whereas the 5687 requires 0.9A.
  
 As I use an external PS, the Sylvania 5687WA is one of my favorite drivers.


----------



## dxanex

sgbwill2 said:


> Some pictures of the La Figaro


 
 The 339 is a gorgeous sounding OTL amp, especially with the HD 650. I can vouch for the Tung-Sol 5998 as I use it in my Crack/Speedball. They are expensive, but the bump in detail and resolution is truly significant.


----------



## MIKELAP

Santa's little tube elf's are starting to get busy .Offer the one you love a tube chances are youll have to duck lol.


----------



## i luvmusic 2

mikelap said:


> i luvmusic 2 said:
> 
> 
> > Please don't bring your CAR inside your house just to power-up your LD amp tubes.
> ...


 
 I hope someone have a very long jumper cables.


----------



## sgbwill2

dxanex said:


> The 339 is a gorgeous sounding OTL amp, especially with the HD 650. I can vouch for the Tung-Sol 5998 as I use it in my Crack/Speedball. They are expensive, but the bump in detail and resolution is truly significant.


 
 Yes I agree it is very nice and the 650 pairs with it very nicely. Unfortunately the 5998's are crazy expensive at the moment though


----------



## gibosi

sgbwill2 said:


> Yes I agree it is very nice and the 650 pairs with it very nicely. Unfortunately the 5998's are crazy expensive at the moment though


 
  
 Given what they often cost, this looks like a pretty good deal:
  
 http://www.head-fi.org/t/744559/matched-pair-5998-tung-sol-in-excellent-condition


----------



## dxanex

gibosi said:


> Given what they often cost, this looks like a pretty good deal:
> 
> http://www.head-fi.org/t/744559/matched-pair-5998-tung-sol-in-excellent-condition




+1 that is a good deal.


----------



## David.M

Hey, guys, it's me again.
  
 I decided to not pull the trigger on the Woo Audio 3, just yet ! Maybe Mordy's or Gibosi's recommendation might save me some bucks !   Even tho my Electro-Harmanox and Sovtek 6h30-PI died very prematurely and early deaths.
  
  
 So I've  been re-listening to this amp with  the Voskhod 6N23P(power tubes) and Mullard M8100.
  
 The Senn HD600 sounded so muffled, buzzy and just plain out weird for the first 30 min. Then i realized I had the Gain Settings on 10, THIS WHOLE TIME !!
  
  
 So i went back to gain 3(the lowest for the LD MK3), and the sound was much more cooler, spacious, soft, and more pleasant. Just the way the HD600 suppose to sound !
  
  
 Even tho my 6N23P are still very new(5 hours) , why does it take so little on the volume dial to reach loud volume. At 10'oclock, the Senn's become quite loud? But the Beyer DT990, I could be comfortable with 1'oclock?
  
  
 Maybe the Voskhod 6N23P need less volume or maybe this is a not a recommended power tube? The tube sounds great, but maybe i am missing something here?
  
  
 My main question is should i try a 6N6P-IR, for power tube ? Will it sound more full bodied? And allow me to play with the volume a little more?


----------



## gibosi

david.m said:


> So I've  been re-listening to this amp with  the Voskhod 6N23P(power tubes) and Mullard M8100.
> 
> The Senn HD600 sounded so muffled, buzzy and just plain out weird for the first 30 min. Then i realized I had the Gain Settings on 10, THIS WHOLE TIME !!
> 
> ...


 
  
 The 6N23P is a 0.30A tube, so no, it is not recommended for use as a power tube. Even so, low-power tubes like the 6N23P tend to work pretty good with high Z cans like your 300 ohm HD600. I have no experience or knowledge regarding the DT990s, but it seems that there are several versions with difference impedance? Which ones do you have?
  
 But to answer your last question, yes, the 6N6P or 6N30P are better suited as power tubes.


----------



## hypnos1

Hi guys.
  
 Further confirmation that our humble LDs are capable of truly outstanding results, once you get into C3g(S) + 6AS7G/6080 land...viz... my Beyer T1s have finally arrived and I just cannot believe the sound I am getting from these babies (and the LD, of course!!). And this is with them straight out of the box. I really thought my HD650s with pure silver cable were wringing nearly every last drop from my modded MKIV SE...HOW WRONG can one be, lol?! These T1s must be taking the LD up into _very_ serious amp territory indeed...not just one level or two, but _many_!!
  
 What they will bring to the Feliks-Audio 'Elise', which hopefully should be winging its way to me towards the end of next week (
	

	
	
		
		

		
		
	


	







), I can't begin to imagine (unless LD + C3gS is equal to the Elise _minus_ C3gS - in which case I'd be MAKING the C3gS work in her, whatever it takes lol!).
  
 I cannot overstate how amazing these T1s are already - they really have blown the 650s RIGHT out of the water...and that's before any burn-in (mind you, they're a darned sight more expensive! But if you can get a decent(?) price on them I think they are worth EVERY penny...no wonder Skylab rates them the King of dynamic HPs. (If you don't believe me, just ask my MKIV SE lol!! 
	

	
	
		
		

		
		
	


	




).


----------



## TrollDragon

The King of the beyer's for sure! I hope to hear a pair one of these days.
  
 You didn't chop the end off of them for direct wire into the MK IV did you?


----------



## Acapella11

hypnos1 said:


> Hi guys.
> 
> Further confirmation that our humble LDs are capable of truly outstanding results, once you get into C3g(S) + 6AS7G/6080 land...viz... my Beyer T1s have finally arrived and I just cannot believe the sound I am getting from these babies (and the LD, of course!!). And this is with them straight out of the box. I really thought my HD650s with pure silver cable were wringing nearly every last drop from my modded MKIV SE...HOW WRONG can one be, lol?! These T1s must be taking the LD up into _very_ serious amp territory indeed...not just one level or two, but _many_!!
> 
> ...


 
  
 I have heard them too, on an Audio-GD Master 9 and they are amazing headphones.


----------



## Acapella11

Here are impressions of (only) two 6SN7 tubes, used as power tubes and compared to Reflektor 6N30P-DR (1983) power tubes after the 6SN7 tubes had their burn in time of certainly over 30 h each. It is a humble selection, I admit 
  
 1. Raytheon JAN-CRP 6SN7WGT, brown base

  
  
 2. Sylvania JAN-CHS 6SN7WGT, brown base

  
  
 3. Reflector 6N30P-DR, 1983

  
  
 Headphones: Sennheiser HD800 /w Draugh v2
 DAC: MDAC, Minumum Phase, connected to LD MKIII via Charleston Cable Company UPOCC cable
 Power: PowerInspired AG500
  
*6N30P-DR*: Sound signature is on the brighter side, energetic, very good imaging, very controlled and articulated bass, “good sized” stage, very good detail retrieval, highest tendency to cause sibilance from these tubes
*Raytheon*: Darker sounding tube, very good imaging and more bass bias than the DR, more controlled bass than the Sylvania, largest and deepest stage, wettest tube, most details, least sibilance, sweet mids, refined, natural, blacker background than Sylvania. Works well once you got used to it, kind of like a LCD 2  lol.
*Sylvania*: Brightness of signature is between Raytheon and DR, “only” good imaging on a high level though, because it doesn’t sound as “clean” as the Raytheon, bass more bloated than the other two tubes, not as deep stage, warmer than the 6N30P-DR and more bass bias, more dynamic sounding than the Raytheon. On first impression more balanced than Raytheon because more treble is presented but the Raytheons sound fine in their own way and not rolled off. Transparent mids, not as “clean” as DRs.
*Conclusion*: Now, would I just give up the DRs for one of these 6SN7 power tubes, totally ignoring the price ofc . No. The DR produces a very energetic quality sound, different but very nice in its own rights. Listening to a pair of headphones on the brighter side (HD800) means the Raytheon tubes match very well. For now, I would keep the DRs as a reference.
  
 Remark: As the sound may still change, or my perception of it, I may need to revise these impressions later 
  
 Edit: I recommend the combination HD800/C3GS/Raytheon JAN CRP 6SN7WGT, brown base: holographic, silky, smooth and revealing. No fatigue whatsoever and lots of details.


----------



## hypnos1

trolldragon said:


> The King of the beyer's for sure! I hope to hear a pair one of these days.
> 
> You didn't chop the end off of them for direct wire into the MK IV did you?


 
  
 Don't tempt me now, TD!  
	

	
	
		
		

		
		
	


	




....but have no fear, I need them to go in the Feliks Elise lol! (And I have NO intention of possibly spoiling these wonderful babies - even though it brought DEFINITE improvement to the 650s in the LD!!).
  
 Sleep sound, my friend...


----------



## i luvmusic 2

hypnos1 said:


> Hi guys.
> 
> Further confirmation that our humble LDs are capable of truly outstanding results, once you get into C3g(S) + 6AS7G/6080 land...viz... my Beyer T1s have finally arrived and I just cannot believe the sound I am getting from these babies (and the LD, of course!!). And this is with them straight out of the box. I really thought my HD650s with pure silver cable were wringing nearly every last drop from my modded MKIV SE...HOW WRONG can one be, lol?! These T1s must be taking the LD up into _very_ serious amp territory indeed...not just one level or two, but _many_!!
> 
> ...


 
 Congrats!


----------



## i luvmusic 2

hypnos1 said:


> trolldragon said:
> 
> 
> > The King of the beyer's for sure! I hope to hear a pair one of these days.
> ...


 
 If i were you i would chopped it..........


----------



## hypnos1

i luvmusic 2 said:


> If i were you i would chopped it..........


 

 Luv you too, baby!!


----------



## i luvmusic 2

I can't remember which one of you guys removed the metal shield on C3g.What is  the metal shield for?without the metal shield is it sensitive to noise?


----------



## mordy

Here is a picture of a C3g with the shield taken off. My assumption is that the shield helps for RF noise. Since this tube does not have much of a glow, taking off the shield does not add much in aesthetics.
  
 The loctal base is crimped to the shield and not attached to the tube. Using the tube without the shield necessitates gluing the base to the glass envelope. Given the very fragile nature of this tube it is best to avoid tinkering too much with it.
  
  

  
 The above tube cracked from normal tube rolling. In order to avoid the tube from breaking, it is necessary to loosen up the tube socket pins and only insert or remove the tube straight down or up, without any side to side movement.


----------



## sgbwill2

mordy said:


> Here is a picture of a C3g with the shield taken off. My assumption is that the shield helps for RF noise. Since this tube does not have much of a glow, taking off the shield does not add much in aesthetics.
> 
> The loctal base is crimped to the shield and not attached to the tube. Using the tube without the shield necessitates gluing the base to the glass envelope. Given the very fragile nature of this tube it is best to avoid tinkering too much with it.
> 
> ...


 
 I believe c3g's were meant to be used in very noisy environments and to reduce noise distortion/microphonics the shields were added. As we arent using them in a noisy environments its fine to use them without the shields. Just remember to keep using the metal base. Personally I didn't glue the base to the tubes and just slotted them into the adapters together and I have had no problems. I would rather look at the tube glow than the ugly metal sheaths though so I am happy .


----------



## i luvmusic 2

mordy said:


> Here is a picture of a C3g with the shield taken off. My assumption is that the shield helps for RF noise. Since this tube does not have much of a glow, taking off the shield does not add much in aesthetics.
> 
> The loctal base is crimped to the shield and not attached to the tube. Using the tube without the shield necessitates gluing the base to the glass envelope. Given the very fragile nature of this tube it is best to avoid tinkering too much with it.
> 
> ...


 
 THANKS! for the Info.
 I will install a loctal socket on a plate/box instead of adapter this way i don't need to removed the tube once inserted to the  socket.The box will be beside the MK III similar to the one in this picture.Incase i want to used the tube for something else at least i can unplug the cables and it's just a matter of re-routing the cable the tube always stays inplace i don't want to remove them once inserted to avoid damage,They are not that cheap.


----------



## ToTje

I'm thinking about trying the Voshkod 6ZH1P tubes out like Dept_of_Alchemy recommended in his 5th post.
  
 I guess these must be them: (Click)
  
 I have absolutely no experience with tubes, but I see some vague similarities with the one I just ordered: (Click)
  
 Have I been lucky and did I accidentally buy really good tubes for a really low price, or are neither of these 2 the real deal and shouldn't I be so greedy and just spend a little more for for instance these?


----------



## i luvmusic 2

So it doesn't hurt to ground the shield?


----------



## i luvmusic 2

I will skipped those i will get a 6HM5 Yugo instead.


----------



## gibosi

totje said:


> I'm thinking about trying the Voshkod 6ZH1P tubes out like Dept_of_Alchemy recommended in his 5th post.
> 
> I guess these must be them: (Click)
> 
> ...


 
  
 They look the same to me. And while I don't remember where I bought mine, but I paid only $15 for a pair, $3 for the tubes and $12 for shipping to the US. $23 for a pair plus $12 for shipping is way too much. You did good.


----------



## ToTje

gibosi said:


> They look the same to me. And while I don't remember where I bought mine, but I paid only $15 for a pair, $3 for the tubes and $12 for shipping to the US. $23 for a pair plus $12 for shipping is way too much. You did good.


 
 Ahhh good to hear, thanks! 
	

	
	
		
		

		
			





 Yeah a buddy of mine recommended the 6J1P-EV tubes since he had great experiences with them. I didn't know the 6J1P-EV are the same as the 6ZH1P-EV then.  I don't always see 6ZH1P-EV as an alternative name for the 6J1P-EV and vice versa, so I wasn't sure that assumption was correct or not.
  
 The fact that I even saw 6ZH1P-EV's for $36 a pair (plus $13,75 for shipping) which have a bit more modern-looking packaging made me think there are are differences between tubes of this line. Perhaps newer ones have some improvements over the older ones?


----------



## Tianming

Has anyone tried Philips 5654W ECG? Any comments on this tube?


----------



## Tianming

Is there any difference between Mullard tubes that are labeled EF95, CV4010, M8100 and 6AK5?


----------



## Acapella11

Got a bit carried away listening to my HD800 with C3GS and Raytheon JAN CRP 6SN7WGT tubes


----------



## mordy

Hi ToTje,
  
 All the 61JP-EV/6Z1HP-EV are basically the same tube. The EV designation indicates a 5000 hour life span. The only difference I know is that some have a minuscule amount of gold in the grid (gold grid). BTW, GE invented the gold grid and used it in its 5Star tubes but never made it into a marketing hype.
  
 The gold grid sounds a little more mellow than the regular version. These tubes require an extra long burn in time - around 110 hours!
  
 As a rule, earlier Russian tubes from before the fall of Communism are said to be better made. Try to get tubes from the 70's or first two-three years 80's.
  
 The difference between a $3 tube and a $ 18 tube is that the guy who sells the more expensive one makes more money on the sale. Psychologically some people may feel that it must be better if it costs more, but I am afraid that this does not apply to NOS tubes.
  
 In general, the prevailing consensus seems to be that tubes made earlier, say in the 40's and 50's (or early 60's), are of better quality. One theory is that the early tube manufacturing had to be more precise in obtaining a good vacuum in the tube. Later, shortcuts were found to get a good vacuum by adding certain chemicals to be activated by the getter flash that would take care of impurities in the tube. The early tubes could not rely on this method, and thus had to use better materials and quality control.


----------



## gibosi

tianming said:


> Has anyone tried Philips 5654W ECG? Any comments on this tube?


 
  
 Philips purchased Sylvania, forget exactly when, and sometime thereafter, began selling Sylvania-manufactured products under the Philips ECG brand. Most of the Philips ECG stuff I see is from the 1980's, and generally speaking, most tubes from the 1980's are usually not all that good. By that time, solid state was the new state-of-the-art, and tubes were being made as cheaply as possible only to keep old gear alive. However, as I don't have these, I can't comment on their sound.....


----------



## ToTje

mordy said:


> Hi ToTje,
> 
> All the 61JP-EV/6Z1HP-EV are basically the same tube. The EV designation indicates a 5000 hour life span. The only difference I know is that some have a minuscule amount of gold in the grid (gold grid). BTW, GE invented the gold grid and used it in its 5Star tubes but never made it into a marketing hype.
> 
> ...


 
 Hey thanks for this very complete answer! 
	

	
	
		
		

		
		
	


	




 Now you mention it, I've also read that about tubes from the cold war being better and such, probably because of better vacuum methods and such. 
  
 Yeah I almost fell for that psychological trap about more expensive = better.


----------



## mordy

Hi Tianming,
  
 You could add Mullard CV850 to your list as well. All these tubes are essentially the same, but some were intended for military use instead of civilian use and supposedly more rugged. I think that CV stands for "common valve" and "M" stands for military version.
  
 The sound signature is similar for all of them, but may vary depending on which factory it was made in and the year of manufacture. The only way to find out what you like is to listen to different pairs in your system. However, as has been discovered on this forum, there are many other better sounding and less expensive tubes.


----------



## mordy

Hi A11,
  
 I can identify with waking up in my listening chair at dawn! Problem was that one time listening to my headphones I decided to play really loud for a short time and fell asleep even though the music was blasting....


----------



## genclaymore

mordy said:


> Hi A11,
> 
> I can identify with waking up in my listening chair at dawn! Problem was that one time listening to my headphones I decided to play really loud for a short time and fell asleep even though the music was blasting....


 

 I most been some boring music to make you sleep at ear shaking volume.  I hope you didnt get rinning in your ears after that.
  


acapella11 said:


> Got a bit carried away listening to my the HD800 with C3GS and Raytheon JAN CRP 6SN7WGT tubes


 

 I wish my T90 cable was like that, maybe it would stop bunching up. It be good if beyer starts using cables that doesn't do that. I even twist tie it in a loop in hope that shorting it would stop that from happening, but nope still did it. Maybe wish I had headphones with removable cables to get around that.


----------



## Tianming

mordy said:


> Hi Tianming,
> 
> You could add Mullard CV850 to your list as well. All these tubes are essentially the same, but some were intended for military use instead of civilian use and supposedly more rugged. I think that CV stands for "common valve" and "M" stands for military version.
> 
> The sound signature is similar for all of them, but may vary depending on which factory it was made in and the year of manufacture. The only way to find out what you like is to listen to different pairs in your system. However, as has been discovered on this forum, there are many other better sounding and less expensive tubes.


 
 Thank you for your reply. Could you recommend some "better sounding and less expensive" tubes?


----------



## TrollDragon

tianming said:


> Thank you for your reply. Could you recommend some "better sounding and less expensive" tubes?


 

 The *tall version* 6HM5's from Yugoslavia are one of the best plug and play driver tubes.
  
 Excellent seller and option to make an offer.
 http://www.ebay.com/itm/6HM5-6HA5-EC900-export-quality-audio-triode-tube-NOS-FREE-SHIPPING-/300879467071


----------



## TrollDragon

genclaymore said:


> I wish my T90 cable was like that, maybe it would stop bunching up. It be good if beyer starts using cables that doesn't do that. I even twist tie it in a loop in hope that shorting it would stop that from happening, but nope still did it. Maybe wish I had headphones with removable cables to get around that.


 
  
 Contact our very own @cCasper TFG dude does some seriously excellent work.
  
 Denon rewire -> http://www.head-fi.org/t/71148/diy-cable-gallery/14100#post_11026710
  
*AMAZING T50RP build...*

  
  
 or Brian at BTG Audio. Looks like he does excellent work and has very reasonable prices.
 http://www.btg-audio.com/


----------



## MIKELAP

For 6HM5 there's also this seller you could buy tube for$ 5.50 each or possibly less                                                                                               http://www.ebay.com/itm/251611916081?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT


----------



## mordy

Hi genclaynmore,
  
 The music wasn't boring at all - I just couldn't stop listening although it was way past my normal bedtime, and that's why i fell asleep around 3am. You are right, my ears were ringing....


----------



## mordy

Hi Tianming,
  
 Definitively try the Yugoslavian Ei 6HM5 tubes (links by TD and Mikelap above) - you will not be disappointed.  Good luck!


----------



## Tianming

Thanks a lot! I will look into EI 6HM5. They looks awesome!


----------



## Tianming

trolldragon said:


> The *tall version* 6HM5's from Yugoslavia are one of the best plug and play driver tubes.
> 
> Excellent seller and option to make an offer.
> http://www.ebay.com/itm/6HM5-6HA5-EC900-export-quality-audio-triode-tube-NOS-FREE-SHIPPING-/300879467071


 
 Actually my amp is not Little Dot. It's something similar to Little Dot Mk1, a hybrid of tube and solid state. It uses two 5654 tubes. Can I directly replace 5654 with 6HM5?


----------



## Johnnysound

totje said:


> I'm thinking about trying the Voshkod 6ZH1P tubes out like Dept_of_Alchemy recommended in his 5th post.
> 
> I guess these must be them: (Click)
> 
> ...


 
 The 3 tubes look  the same to me, only different years of manufacture, and as far as I know, with the LDMKIII you do not really need "matched pairs" on the input side.  The price you paid is OK, just be sure to get spare tubes because the 6ZH1P can be microphonic (it happened to me).  I liked very much the sound of that tubes indeed...


----------



## hypnos1

acapella11 said:


> Got a bit carried away listening to my the HD800 with C3GS and Raytheon JAN CRP 6SN7WGT tubes


 
  
  


mordy said:


> Hi A11,
> 
> I can identify with waking up in my listening chair at dawn! Problem was that one time listening to my headphones I decided to play really loud for a short time and fell asleep even though the music was blasting....


 
  
 Hi guys...when that happens to me (but luckily nowhere near dawn!!)...BOY, do I feel cheated lol!!


----------



## ToTje

johnnysound said:


> The 3 tubes look  the same to me, only different years of manufacture, and as far as I know, with the LDMKIII you do not really need "matched pairs" on the input side.  The price you paid is OK, just be sure to get spare tubes because the 6ZH1P can be microphonic (it happened to me).  I liked very much the sound of that tubes indeed...


 
 Coolcool! 
 Yeah I ordered 2 pairs, so 4 tubes in total.


----------



## TrollDragon

tianming said:


> Actually my amp is not Little Dot. It's something similar to Little Dot Mk1, a hybrid of tube and solid state. It uses two 5654 tubes. Can I directly replace 5654 with 6HM5?


 
  
 Sorry I can not say that they will work without any problem in your amplifier.
  
 You will have to check your manual to see what compatible tubes you can use. The 6HM5 is a triode where the 5654 is a pentode, so it really all depends on how the 5654's are configured.
  
 I do not recommend blindly trying them.


----------



## Tianming

trolldragon said:


> Sorry I can not say that they will work without any problem in your amplifier.
> 
> You will have to check your manual to see what compatible tubes you can use. The 6HM5 is a triode where the 5654 is a pentode, so it really all depends on how the 5654's are configured.
> 
> I do not recommend blindly trying them.


 
 The manual says it is compatible with M8100, CV4010, EF95, 6J1 and 5725. Do you think it may work with 6HM5?


----------



## TrollDragon

tianming said:


> The manual says it is compatible with M8100, CV4010, EF95, 6J1 and 5725. Do you think it may work with 6HM5?


 

 Hard to say, the LD amps use the pentodes as a _strapped_ triode with the extra grid either floating or shorted to the cathode. If your amplifier implements the second grid like most do designed around the EF95 type tubes then the 6HM5's will not work.
  
 What is the make and model of your amp?


----------



## Tianming

trolldragon said:


> Hard to say, the LD amps use the pentodes as a _strapped_ triode with the extra grid either floating or shorted to the cathode. If your amplifier implements the second grid like most do designed around the EF95 type tubes then the 6HM5's will not work.
> 
> What is the make and model of your amp?


 
 Well it's a DIY amp. Here is a link but it's in Chinese http://item.taobao.com/item.htm?spm=a1z10.1.w4004-1206581359.19.jchNaS&id=1882066537. It probably won't work with 6HM5. I think I will try 6HM5 when I upgrade to LD in future. Thanks a lot for your help!


----------



## TrollDragon

tianming said:


> Well it's a DIY amp. Here is a link but it's in Chinese http://item.taobao.com/item.htm?spm=a1z10.1.w4004-1206581359.19.jchNaS&id=1882066537. It probably won't work with 6HM5. I think I will try 6HM5 when I upgrade to LD in future. Thanks a lot for your help!


 
 No problem, if you have a schematic of the amp since it is a DIY that would tell for sure. I don't read Chinese so I cant tell if there is a schematic available or not.


----------



## autoteleology

Does anyone know which tubes deliver the best detail and imaging? Anything the first post doesn't cover?


----------



## gibosi

tus-chan said:


> Does anyone know which tubes deliver the best detail and imaging? Anything the first post doesn't cover?


 
  
 Assuming that you don't want to mess with adapters, the 6HM5 is well worth checking out, Sylvania, GE or Ei (Yugoslavia) tall bottles. For some reason, the short bottles, which are actually made by Siemens, do not sound near as good. Set your LD for EF95, plug them in and play.


----------



## Johnnysound

tianming said:


> Actually my amp is not Little Dot. It's something similar to Little Dot Mk1, a hybrid of tube and solid state. It uses two 5654 tubes. Can I directly replace 5654 with 6HM5?


 
 You can try the Voshkods 6J1P-EV (6ZH1P) which are 5654 compatible.  In my opinion, very good sounding tubes.  See post 8569


----------



## Tianming

johnnysound said:


> You can try the Voshkods 6J1P-EV (6ZH1P) which are 5654 compatible.  In my opinion, very good sounding tubes.  See post 8569


 
 Is there any difference between 6J1P-EV, 6Ж1n-EB and 6ZH1P? From my eBay search, 6ZH1P is much more expensive. Also the price of 6J1P-EV varies a lot. Any recommendations?


----------



## Johnnysound

tianming said:


> Is there any difference between 6J1P-EV, 6Ж1n-EB and 6ZH1P? From my eBay search, 6ZH1P is much more expensive. Also the price of 6J1P-EV varies a lot. Any recommendations?


 
 I am not a tube "expert", but  those are the same basic tube,  the various  denominations come from different  translations of of the original cyrillic (russian) name.  Read Post # 8555 by mordy for a complete explanation.    My recommendation ?  the 6J1P  tubes are real cheap (lots of stocks) so  do not pay more than 5 dollars per tube,  try to get the oldest ones possible with "gold grids"... and buy at least 4, to have spares in case some are microphonic.


----------



## MIKELAP

tianming said:


> johnnysound said:
> 
> 
> > You can try the Voshkods 6J1P-EV (6ZH1P) which are 5654 compatible.  In my opinion, very good sounding tubes.  See post 8569
> ...


----------



## ToTje

tianming said:


> Is there any difference between 6J1P-EV, 6Ж1n-EB and 6ZH1P? From my eBay search, 6ZH1P is much more expensive. Also the price of 6J1P-EV varies a lot. Any recommendations?


 
 Hehehe I just asked the same thing a bit earlier: the only difference between them apparently is the price, nothing else.
 Soms tubes actually come with all those names. I bought the tubes that are $3 a pair on eBay, and apparently they are exactly the same as the $36 a pair tubes.
  
 If you look a bit further, you'll see that some tubes even have all those codes you mentioned.
  
 However, try (if possible) to get tubes from before '83. Read the previous page in this topic if you want to know more.


----------



## ToTje

mikelap said:


>


 
 Oh? So there actually is a difference? RF pentode vs rectifier?
  
 Edit: I think these tubes must always have a combination of these codes, since very early in this topic others also say they're really the same thing.


----------



## Artsi

I haven't been active at all here. 
	

	
	
		
		

		
		
	


	



  
 At last i got my own simple emission tube tester. Superior Instrument Co. TV-11. It needed just a little service and now it works like new and can test all my tubes. Since it is just emission tester, it's not very scientific or absolutely accurate. However there seems to be many suspicious tubes in my collection and one previously used 6DJ8 showed some flashing welding inside one triode. Even new tubes are not safe, one JJ ECC83 tube was very weak and triodes were far from matching ones. Won tube tester from USA ebay, and it uses 110v, so i needed step down transformer too. Better testers are just far too expensive.


----------



## Artsi

Haven't been resting much with my diy amps. Here is phono preamp for MM cartridges. Followed this schematic http://www.hagtech.com/pdf/cornetoctal.pdf. Rectifier is 6X5 in my amp. Somehow this was rather tricky to make quiet. There is 2 6SL7s triodes doing their best to amplify signal in series. It is like little dot at max volume and more. Input in front and output from back to keep signal path as short as possible. Those GE 6SL7GT coinbases look fun.
  
 Next week i should get 2 old Hammond Organ amplifiers. Around 35KG of some serious stuff. Main transformers from those push about 6A 5v, 10A 6.3v and to anode 415v-0-415v. Got those hammonds rather cheap from GB and there is 6 output transformers too. I need to buy more tubes like EL34, KT88, 5U4G and 5Z3 to make amplifiers with those transformers. So they are not primarily for headphones.


----------



## Johnnysound

artsi said:


> I haven't been active at all here.
> 
> 
> 
> ...


 
 Wow, very nice tester, congratulations.    In my "Tube 101"  self imposed course,  I always wondered why in the tube era there was no "standard"  technology  for testing tubes.  As a result, it is amazing to read that  vintage tube testers are quite  different from each other,  because  almost every single  brand employed its own design.   
  
 I understand that  "emission"   tests  the basic function  of the tube,   in other words its ability to convert volts to amperes with a fixed signal.  The number  will give an indication of  its life span, and  so you can detect  "bad"  tubes that are below the standard.  I also read  that this test  should be complemented with a "transconductance" test to give a more accurate idea, because "low emission" tubes should  be perfectly operational  if they have good transconductance values...and still have a long life span ahead.    What ?   Maybe there are many "endgame" 1945 Tung-Sol round plates for $ 5, because they tests "low"... low in emissions only  ? 
  
 In any case,   transconductance  (Gm) looks very relevant  in terms of SQ, because it measures the "ratio"  of  V to Ampere emission with a  variable input,  or the "efficiency" of the tube in real world conditions.  The higher, the better, and  this value  is obviously  important for  audio,  because high GM  translates into better S/N,  more gain,   and a linear current output.   A higher GM means less distortion between input and output ,  and this is what we want  in  an input tube, which deals with small voltages.     It is not by chance that the  Siemens C3g  have super high GM values, (4 times that of other tubes)  because the engineers decided that this parameter was necessary for low-noise, critical audio applications.      Continuing with my "course",  I discovered   that high GM was also introduced into tubes designed for radio or early computer applications,   to increase their performance and durability. .  The 6AU6 (GM¨= 4500)  was replaced in RF amplifiers by the 6AH6 (GM= 9000) with excellent results.  (The 6485 is  just a "computer grade" 6AH6 tube).   I have heard both,   and while the Mullard 6AU6 sounds quite good, have deep bass and a mellow, relaxed sound, the Tung-Sol 6485s are clearly above,in all terms...


----------



## Nic Rhodes

I got interested in transconductance  (Gm) some 20+ years ago whilst experrimenting and came across some fun tubes. Some were well known with high price tags but others were not. Long known about were the 417a and 437 triodes and 7788 pentode (look that one up, Gm 50,000). However even when I looked at these there were good value variants like 5842 for the 417 (Gm 24,000), 3a/167m for the 437 and E810F / CV5809 for the 7788.
  
 This started to lead me to other tubes like the 6688 / E180F (Gm 16,000) which appeared to me to be like the 404a / 5847 but just on a different base wiring and much cheaper then. On route I did lots of work with 5687, 7044, 7119,  E182CCs. My paths crossed with 12SX7GTs, 6BL7GT, 6BX7GTs, EC8010, 8556, EC8020, D3a, C3G, C3M etc and nowdays we also have access to Russian 6C45Pis. It was a great journey but I did learn theat my desire for high GM is not the magic path to audio bliss I thought it was but it thinking this way was the foundation of 20+ years of adiction  Often some tubes came with some excellent spec (but not the best) that were being forgotton and went for cents / pennies like the excellent 6688 / E180F.....whilst the world used second rate Russian 6922 / E88CC into designs which were vastly inferior to the tubes the hobbiest had access to.


----------



## rosgr63

Hi Nic,
  
 I too have discovered that the highest possible test scores don't mean audio bliss.
  
 Some tubes of the same type but of different maker that don't test as strong may sound much better.
  
 This is the tube magic.......
  
 I am still learning been into headphone more than 40 years.


----------



## Nic Rhodes

It has got me thinking again, given the love for 6080 / 6AS7G as an output tube with a new PSU, has anyone tried the 6C33B Ulyanov made 'trawler valve'? [You recognise it with it the tripple nipples]. I know it is getting rarer now but technically it has always been a valve that look excellent for OTL / SE outputs.


----------



## bbmiller

rosgr63 said:


> Hi Nic,
> 
> I too have discovered that the highest possible test scores don't mean audio bliss.
> 
> ...


 
 So were you looking at tubes in the 6SN7 family would you only look at what people have to say about type and brand and not look at this transconductance? And if you did look at transconductance is it always posted as GM and the datasheets order of their other ways to post transconductance other than GM figures?


----------



## gibosi

nic rhodes said:


> It has got me thinking again, given the love for 6080 / 6AS7G as an output tube with a new PSU, has anyone tried the 6C33B Ulyanov made 'trawler valve'? [You recognise it with it the tripple nipples]. I know it is getting rarer now but technically it has always been a valve that look excellent for OTL / SE outputs.


 
  
 The Eddie Current Zana Deux SE uses a pair of 6C33C-B....
  
 http://www.eddiecurrent.com/Zanadeux.html


----------



## i luvmusic 2

artsi said:


> Haven't been resting much with my diy amps. Here is phono preamp for MM cartridges. Followed this schematic http://www.hagtech.com/pdf/cornetoctal.pdf. Rectifier is 6X5 in my amp. Somehow this was rather tricky to make quiet. There is 2 6SL7s triodes doing their best to amplify signal in series. It is like little dot at max volume and more. Input in front and output from back to keep signal path as short as possible. Those GE 6SL7GT coinbases look fun.
> 
> Next week i should get 2 old Hammond Organ amplifiers. Around 35KG of some serious stuff. Main transformers from those push about 6A 5v, 10A 6.3v and to anode 415v-0-415v. Got those hammonds rather cheap from GB and there is 6 output transformers too. I need to buy more tubes like EL34, KT88, 5U4G and 5Z3 to make amplifiers with those transformers. So they are not primarily for headphones.


 
 Very nice!Where did you get the power switch?
  
 Thanks!


----------



## TrollDragon

i luvmusic 2 said:


> Very nice!Where did you get the power switch?
> 
> Thanks!


 

I found this really neat thing here...


----------



## i luvmusic 2

trolldragon said:


> i luvmusic 2 said:
> 
> 
> > Very nice!Where did you get the power switch?
> ...


 
 I will check it out .THANK TD!


----------



## TrollDragon

This one here from seeed studio's is great with the OSH logo, my Arduino came from seeed studio so they are a reputable seller.
OSH Logo power switch.


----------



## i luvmusic 2

trolldragon said:


> This one here from seeed studio's is great with the OSH logo, my Arduino came from seeed studio so they are a reputable seller.
> OSH Logo power switch.


 
 Too may to choose from.I need 2 one for the Crack and the SEX.Thanks!


----------



## rosgr63

bbmiller said:


> So were you looking at tubes in the 6SN7 family would you only look at what people have to say about type and brand and not look at this transconductance? And if you did look at transconductance is it always posted as GM and the datasheets order of their other ways to post transconductance other than GM figures?


 

 My tubes of interest which I currently use are 2C51/6SL7/6SN7/6F8G/ECC32/ECC34/ECC35/6AS7G/45/6A3/VT-52/PX4/300B/6BL7/6H12/310/328/5692/7062/12SN7/25SN7/5692/5998 etc not going into rectifiers .
  
 I read what people say but over the years I have been able to try for myself and form my own albeit limited opinion.


----------



## Nic Rhodes

gibosi said:


> The Eddie Current Zana Deux SE uses a pair of 6C33C-B....
> 
> http://www.eddiecurrent.com/Zanadeux.html


 

  thanks. That has a good reputation,I wonder who will have the first LD with 33s?


----------



## Oskari

totje said:


> Oh? So there actually is a difference? RF pentode vs rectifier?
> 
> Edit: I think these tubes must always have a combination of these codes, since very early in this topic others also say they're really the same thing.


 
  
 It is the 6Ж1П-ЕВ that you are talking about. The rest are just garbled transliterations from the Cyrillic into the Latin script.


----------



## Oskari

nic rhodes said:


> … 7788 pentode … variants like … E810F / CV5809 for the 7788.


 
  
 Same thing really, 7788 is the US type number.


----------



## gibosi

nic rhodes said:


> thanks. That has a good reputation,I wonder who will have the first LD with 33s?


 
  
 With a heater current of 6.6A at 6.3V, the 6C33C is a beast! More so than a 6336! Running a pair of these in our LD's would require an external heater power supply capable of providing about 20A. Given that running a pair of 2.5A 6AS7's is not without risk, I would be very leery about trying to use the 6C33C in an LD....
  
 Some time ago, I asked Glenn, our resident amp-builder extraordinaire, if he had ever considered using this tube:
  
 http://www.head-fi.org/t/600110/2359glenn-studio/9735#post_10578437
  
 "I did but changed my mind I even have all the parts to build one.
 But I would have to use 4 in my circuit they have power hungry filaments
 Means big transformer for power very heavy to much to ship especially to Europe.
 Plus I don't think they sound that great and have noise issues.
 Plus you are stuck with that tube no rolling."


----------



## gibosi

bbmiller said:


> So were you looking at tubes in the 6SN7 family would you only look at what people have to say about type and brand and not look at this transconductance? And if you did look at transconductance is it always posted as GM and the datasheets order of their other ways to post transconductance other than GM figures?


 
  
 First, I think you should consider what others have said about the different types and brands. In lieu of purchasing samples of every tube out there, the observations of others can help you narrow the list down to a select few that seem worth trying. The importance of measurements, including transconductance, to my mind is in helping to determine if the tube is almost new versus well used. Obviously, a tube that tests like new has a higher probability of having a longer useful life, and depending on price, might be the better value.
  
 That said, I often purchase well-used, cheap tubes just to sample their flavor. If the flavor is not to my liking, I am not out all that much. And if the flavor is to my liking, I will then be on the lookout for new, or almost new tubes at a good price.


----------



## mordy

Hi Gibosi,
  
*"Given that running a pair of 2.5A 6AS7's is not without risk"*.
  
 Having run a pair of 2.5A power tubes using a 15A voltage regulator and a PC 15A power supply in the LD MKIII (the amp is fan cooled) for very extended time periods my humble opinion is that it poses no risk at all.
  
 For some reason it was postulated that it would be risky to run 2.5A tubes in the Little Dot amps but this is simply not true based on my extended personal experience.
  
 I even asked Glenn if it would be dangerous to run 5A 6336 power tubes in the LD. He answered that these tubes would present the same electrical picture to the amp as the 2.5A tubes and would be compatible. However, he added that since these tubes would not add anything, he questioned why I would want to use them. Based on this I did not pursue using 6336 tubes.
  
_2359glenn:_
_Does the 6336 sound better then a 6AS7   No it will react the same in the same circuit but don't sound better.Maybe worse no sense in using it unless you are trying to drive low impedance phones._
_If your filament power supply can supply 15 amps it should be OK. The 6336 acts like a 6AS7 without the cathode resistor being changed._
  
 So, in all fairness, can we kill the myth that 2.5A tubes are dangerous to use in the LD MKIII?
  
 I want to add that using C3g driver tubes with a pair 2.5A 6080 power tubes barely makes my amp warm. The 6080s give me the punch and slam I want in the bass and everything  else I tried sounds puny (6N6 family, 6SL7, 6SN7) in comparison.


----------



## hypnos1

mordy said:


> Hi Gibosi,
> 
> *"Given that running a pair of 2.5A 6AS7's is not without risk"*.
> 
> ...


 
  
 Hi mordy.
  
 I agree with you about the amp not getting overly warm (mine being the MKIV SE of course), which would _appear_ to indicate nothing too untoward is happening - but who knows just how long those cathode resistors will continue to take the punishment?...Perhaps forever, but the question mark remains...
	

	
	
		
		

		
			





. As I shall soon be devoting most of my time to the upcoming Feliks-Audio Elise I personally am not at all worried...I feel I have had more than my money's worth out of the LD already lol!. But even if I were to continue with the LD and its 'punishment?', IF those resistors were to go at least it wouldn't be a major job to get them replaced (?)....(Yours and mine have certainly lasted pretty well already!..
	

	
	
		
		

		
		
	


	




).
  
 So I wish you continued good luck, mon ami...


----------



## bharat2580

Ok. All you learned people. 

What are the direct swap power tubes for the mk iii. I have V4 board. 
I have the 6n6p. And the ir which have noise so i need new ones.

I dont want to fiddle with the board so please suggest the direct replacements.


----------



## MIKELAP

bharat2580 said:


> Ok. All you learned people.
> 
> What are the direct swap power tubes for the mk iii. I have V4 board.
> I have the 6n6p. And the ir which have noise so i need new ones.
> ...


 
 Power tube reviews Page 201 post # 3007


----------



## gibosi

mordy said:


> Hi Gibosi,
> 
> *"Given that running a pair of 2.5A 6AS7's is not without risk"*.
> 
> ...


 
  
 When running a pair of 6AS7/6080, *lemonjelly* noticed that some resisters got hot enough that they partially melted. He had one get hot enough that the connection broke, although he was able to successfully resolder it. Further, it is a fact that a pair of 6AS7s draw significantly more current than these resisters were designed to handle.
  
 http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/7170#post_10808730
  
 Those who are comfortable working on circuit boards should consider replacing these resisters with higher-rated components. For more information, I suggest you search this thread for *lemonjelly*'s posts. Further, he created a very informative thread on some of his mods here:
  
 http://www.head-fi.org/t/439449/little-dot-mk-iii-mods/135
  
 And therefore, I stand by my statement: 
  
 "Running a pair of 2.5A 6AS7's is not without risk"
  
 That you, Hypnos and several others have yet to experience a failure suggests that this risk is not large or certain, but nevertheless, it is incumbent on those of us who dispense advice to make sure people understand all the risks and benefits, so that they may make an informed decision.


----------



## mordy

Came across another C3 variant that I did not know about - the C3e.
  




  
 This tube is an 18V 0.24A tube. Would it be suitable for the LD amp?


----------



## Nic Rhodes

oskari said:


> Same thing really, 7788 is the US type number.


 

  Yes but the point was the E810F was much much cheaper 20 years ago even from the same supplier. I bought a decent sized stash for pennies of the european labeled variant from Wilson Valves but the american labelelled variat was quite expensive from the same guy.


----------



## Nic Rhodes

gibosi said:


> With a heater current of 6.6A at 6.3V, the 6C33C is a beast! More so than a 6336! Running a pair of these in our LD's would require an external heater power supply capable of providing about 20A. Given that running a pair of 2.5A 6AS7's is not without risk, I would be very leery about trying to use the 6C33C in an LD....
> 
> Some time ago, I asked Glenn, our resident amp-builder extraordinaire, if he had ever considered using this tube:
> 
> ...


 
  
 I think I might ave a play with the 6C33C sometime in the future. Monster filament transformers are here already and other changes are easy to do. The Zana amp wets the appetite, it is obviously capable of quality.


----------



## gibosi

mordy said:


> Came across another C3 variant that I did not know about - the C3e.
> 
> 
> 
> ...


 
  
 Electrically, it would probably work if strapped as a triode and provided with an external heater power supply. The biggest problem I see is that it has a weird "EU-Telephone 9-pin base" which is different than anything I have ever seen.....


----------



## gibosi

nic rhodes said:


> I think I might ave a play with the 6C33C sometime in the future. Monster filament transformers are here already and other changes are easy to do. The Zana amp wets the appetite, it is obviously capable of quality.


 
  
 Since you have everything you need, it sounds like it would be a fun project. If and when you do this, please let us know how they compare to the 6AS7/6080 types.
  
 Cheers


----------



## hypnos1

gibosi said:


> When running a pair of 6AS7/6080, *lemonjelly* noticed that some resisters got hot enough that they partially melted. He had one get hot enough that the connection broke, although he was able to successfully resolder it. Further, it is a fact that a pair of 6AS7s draw significantly more current than these resisters were designed to handle.
> 
> http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/7170#post_10808730
> 
> ...


 
  
 Hi g.
  
 As with ALL "modifications", the caveat must _always_ be :  "AT YOUR OWN RISK!!!", lol....
	

	
	
		
		

		
		
	


	




...


----------



## Oskari

nic rhodes said:


> Yes but the point was the E810F was much much cheaper 20 years ago even from the same supplier. I bought a decent sized stash for pennies of the european labeled variant from Wilson Valves but the american labelelled variat was quite expensive from the same guy.


 
  
 That's rather daft, both were probably made at Heerlen, too. (Well, maybe Hicksville played a part.)


----------



## i luvmusic 2

I received the C3g today but can't do anything with them until next week,waiting for the Loctal sockets.


----------



## Nic Rhodes

oskari said:


> That's rather daft, both were probably made at Heerlen, too. (Well, maybe Hicksville played a part.)


 

 whether it it is daft or not, it remains true which is why I posted as such. They are a mixture of Hicksville (expensive Amperex and cheap Mullards) and Heerlen (cheap Mullard)


----------



## Oskari

nic rhodes said:


> whether it it is daft or not, it remains true which is why I posted as such. They are a mixture of Hicksville (expensive Amperex and cheap Mullards) and Heerlen (cheap Mullard)


 
  
 Not doubting you. I have only Philips Heerlens in my stash.


----------



## Johnnysound

nic rhodes said:


> I got interested in transconductance  (Gm) some 20+ years ago whilst experrimenting and came across some fun tubes. Some were well known with high price tags but others were not. Long known about were the 417a and 437 triodes and 7788 pentode (look that one up, Gm 50,000). However even when I looked at these there were good value variants like 5842 for the 417 (Gm 24,000), 3a/167m for the 437 and E810F / CV5809 for the 7788.
> 
> This started to lead me to other tubes like the 6688 / E180F (Gm 16,000) which appeared to me to be like the 404a / 5847 but just on a different base wiring and much cheaper then. On route I did lots of work with 5687, 7044, 7119,  E182CCs. My paths crossed with 12SX7GTs, 6BL7GT, 6BX7GTs, EC8010, 8556, EC8020, D3a, C3G, C3M etc and nowdays we also have access to Russian 6C45Pis. It was a great journey but I did learn theat my desire for high GM is not the magic path to audio bliss I thought it was but it thinking this way was the foundation of 20+ years of adiction  Often some tubes came with some excellent spec (but not the best) that were being forgotton and went for cents / pennies like the excellent 6688 / E180F.....whilst the world used second rate Russian 6922 / E88CC into designs which were vastly inferior to the tubes the hobbiest had access to.


 
 Yes, I do totally agree,  better specs ( higher Gm in this case) does not necessarily translates into  SQ.   I have some Ukranian "no brand" 6J1Ps that imitate the 6485 (same Gm) , but its SQ is very far below.   The Brimar 6AU6s (with half the Gm of  my 6J1Ps)   sound much better.... so Gm alone will not tell the story.


----------



## Acapella11

I have received three pairs of 5687 tubes (Tung Sol 5687WA, supposedly Raytheon manufactured but Siemens label 5687WB, RCA 5687) and even though I do not want to draw a final conclusion yet, I can say that these are some vibrant power tubes worth rolling - with adapter - not to forget!


----------



## sgbwill2

acapella11 said:


> I have received three pairs of 5687 tubes (Tung Sol 5687WA, supposedly Raytheon manufactured but Siemens label 5687WB, RCA 5687) and even though I do not want to draw a final conclusion yet, I can say that these are some vibrant power tubes worth rolling - with adapter - not to forget!


 
 As far as power tubes go the 5687's are the best I have yet to try. Far better than the 6SN7/6F8G variants I have tried and I have only tried the GE 5 star 5687's which aren't supposedly the best sounding ones.


----------



## mordy

I have used the 5687 as a driver tube with excellent results. The only tube so far that eclipses it is the C3g - the C3g sounds like a 5687 on steroids. The only area where the 5687 beats the C3g is in mid bass detail, but otherwise the C3g is overall superior. (These are my personal impressions - YMMV)
  
 Haven't tried the 5687 yet as power tube, but I am very satisfied with the 6AS7/6080 as power tubes. Is there anyone out there that has compared the 6080 (or 6AS7) to the 5687 as power tubes?


----------



## genclaymore

My EI 6HM5 came took almost 2 weeks. So far I like them but they still burning in. I kind of wish I knew about them from the start, i could have saved money on tubes and got these instead. When I first turned it on, the EI light up bright, kinda of scared me for a second. Had some odd smell but i don't know if that was the from the stickers that was on them or what, The smell died down tho after using it for a while.


----------



## mordy

Hi glenclaymore,
  
 The scary flash when turning on this tube is a quick heat feature and is perfectly normal for this tube. Nuthin' to worry about (but it scared me as well until I found out what it was).
  
 I wish we could post something on this blog for new members - that it should be read backwards from the most recent to the earlier posts. That way people would have access to the newest and best tube information for the LD amps instead of starting from the beginning with the Mullards and Voskhods....


----------



## gibosi

mordy said:


> I wish we could post something on this blog for new members - that it should be read backwards from the most recent to the earlier posts. That way people would have access to the newest and best tube information for the LD amps instead of starting from the beginning with the Mullards and Voskhods....


 
  
 It appears that the Thread Starter, Dept_of_Alchemy, was last online on 5/7/12. And I wonder if it is possible for someone else to "take over" the care and maintenance of threads in instances like this where the original starter seems to have left Head-Fi. If someone would be interested in doing so, it might be worth contacting the Moderator to find out if Head-Fi has procedures to handle situations like this......


----------



## bobbyblack

Hi guys,

i buy it LD MK3 1 month ago with upgraded tubes Mullard M8100/CV4010 and i use this with SENNHEISER HD650 .The sound is v.nice but i feel i miss some of the high frecvency range so you can tell me some of the tubes with clear highs?Thx.in advance!


----------



## sgbwill2

mordy said:


> I have used the 5687 as a driver tube with excellent results. The only tube so far that eclipses it is the C3g - the C3g sounds like a 5687 on steroids. The only area where the 5687 beats the C3g is in mid bass detail, but otherwise the C3g is overall superior. (These are my personal impressions - YMMV)
> 
> Haven't tried the 5687 yet as power tube, but I am very satisfied with the 6AS7/6080 as power tubes. Is there anyone out there that has compared the 6080 (or 6AS7) to the 5687 as power tubes?


 
 I briefly tried some RCA 6AS7's with the LD without using external heaters and due to this I didn't use them for long but from what I can remember I preferred the 6AS7's. The amount of detail was similar but the soundstage of the 6AS7's were far superior.


----------



## ToTje

bobbyblack said:


> Hi guys,
> 
> i buy it LD MK3 1 month ago with upgraded tubes Mullard M8100/CV4010 and i use this with SENNHEISER HD650 .The sound is v.nice but i feel i miss some of the high frecvency range so you can tell me some of the tubes with clear highs?Thx.in advance!


 
 I found the first 5 posts of this topic to be extremely helpful; you'll see very detailed descriptions of the sound of many different tubes there.
 Your impressions of the Mullard M8100 seem to be correct, when you read these posts.


----------



## gibosi

I think it is very likely that the 6AS7 is superior to the 5687, given their popularity in a number of commercially avaiable amps. However, what makes the 5687 unique is that with a simple pin-adapter, it can be used in the LD without an external heater power supply. And in this regard, it gives LD owners a real alternative to the 6N6P-type power tubes.


----------



## gibosi

bobbyblack said:


> i buy it LD MK3 1 month ago with upgraded tubes Mullard M8100/CV4010 and i use this with SENNHEISER HD650 .The sound is v.nice but i feel i miss some of the high frecvency range so you can tell me some of the tubes with clear highs?Thx.in advance!


 
  
 GE, Sylvania or Ei (Yugoslavia) 6HM5. When searching for these tubes, you will notice that some are tall bottles and some short. In our experience, the tall bottles sound better. In order to use these tubes, set your LD for EF95.


----------



## sgbwill2

gibosi said:


> I think it is very likely that the 6AS7 is superior to the 5687, given their popularity in a number of commercially avaiable amps. However, what makes the 5687 unique is that with a simple pin-adapter, it can be used in the LD without an external heater power supply. And in this regard, it gives LD owners a real alternative to the 6N6P-type power tubes.


 
 I agree the 6as7's are superor however it is far less hassle to use the 5687's and they still sound great and can generally be picked up cheaper as well.


----------



## hypnos1

mordy said:


> Hi glenclaymore,
> 
> The scary flash when turning on this tube is a quick heat feature and is perfectly normal for this tube. Nuthin' to worry about (but it scared me as well until I found out what it was).
> 
> I wish we could post something on this blog for new members - that it should be read backwards from the most recent to the earlier posts. That way people would have access to the newest and best tube information for the LD amps instead of starting from the beginning with the Mullards and Voskhods....


 
  
 Hi mordy.
  
 Agree with you 1000%...why on Earth do newcomers (bless 'em! 
	

	
	
		
		

		
			





) keep on spending precious time and money backtracking to inferior - and sometimes ridiculously expensive - tubes that we have already gone through the process (sometimes painful!) of testing and eliminating? We have tried on numerous occasions to spare people these troubles....PLEASE GUYS, learn from OUR mistakes/expense - I assure you it's well worth it, lol!!  
	

	
	
		
		

		
		
	


	




...(Mind you, there's something to be said for a _certain_ amount of trialling lower-ranked tubes first so as to recognise and appreciate the better ones!...What we try to do, however, is to help _minimise_ this necessary element of gaining experience...but we wouldn't want to spoil _all_ the aspects of tube-rolling - pleasure AND pain!!)...
  
 HAPPY ROLLING....


----------



## MIKELAP

gibosi said:


> I think it is very likely that the 6AS7 is superior to the 5687, given their popularity in a number of commercially avaiable amps. However, what makes the 5687 unique is that with a simple pin-adapter, it can be used in the LD without an external heater power supply. And in this regard, it gives LD owners a real alternative to the 6N6P-type power tubes.


 
  What is better 5687 or is it the 5687WA and what brand ,looks like going rate for these is $30.00 or $40.00 each rather expensive !


----------



## TrollDragon

What you might want to do is start a "New Little Dot Tube Rolling" thread with updated information and have an administrator close this thread and put a forward link at the end to the new thread.

 That way you could start a new updated thread and possibly a Wiki for all the new LD users.
  
 Just my 2 peso's


----------



## mordy

Hi Mikelap,
  
 To my surprise almost all of the 5687 tubes I tried sound very good. Haven't shopped lately, but was able to buy them each for $8 or less a few months ago. Since you could use just a single tube as a driver, I found that single tubes are less than pairs (or quads) proportionately. Did not hear much of a difference between older tubes and newer WA types.
  
 Seems to me that GE and RCA are priced lower than Tung Sol, Sylvania and Raytheon.
  
 As always, patience pays off, and if you keep looking you should be able to snag good buys. Just checked now on Ebay - there are three buy it now offers for single tubes for $8 or less, and two auctions. One is for a single tube starting at under $7, another for four tubes (two RCA and 2 TS) starting at $14.
  
 Good luck!


----------



## MIKELAP

mordy said:


> Hi Mikelap,
> 
> To my surprise almost all of the 5687 tubes I tried sound very good. Haven't shopped lately, but was able to buy them each for $8 or less a few months ago. Since you could use just a single tube as a driver, I found that single tubes are less than pairs (or quads) proportionately. Did not hear much of a difference between older tubes and newer WA types.
> 
> ...


 
 I could use a single 5687 as driver how exactly .Thanks


----------



## Acapella11

gibosi said:


> I think it is very likely that the 6AS7 is superior to the 5687, given their popularity in a number of commercially avaiable amps. However, what makes the 5687 unique is that with a simple pin-adapter, it can be used in the LD without an external heater power supply. And in this regard, it gives LD owners a real alternative to the 6N6P-type power tubes.


 
 +1  That's it! And on top, they sound good.


mikelap said:


> What is better 5687 or is it the 5687WA and what brand ,looks like going rate for these is $30.00 or $40.00 each rather expensive !


 
  


mordy said:


> Hi Mikelap,
> 
> To my surprise almost all of the 5687 tubes I tried sound very good. Haven't shopped lately, but was able to buy them each for $8 or less a few months ago. Since you could use just a single tube as a driver, I found that single tubes are less than pairs (or quads) proportionately. Did not hear much of a difference between older tubes and newer WA types.
> 
> ...


 
  
 Prices vary and I have bought mine for $30 - $40 / pair. Might follow Mordie's advice for the next ones though  However, if you consider that a pair of 6N30P tubes is $40 to $50 and the 5687s sound better, then it sounds like they are reasonably priced, if not bargains. I am sure some members of this forum have spend quite a bit on their 6SN7 or 6AS7 tubes to and easily above this mark as they are more sought after.
 From the quick comparison I did, the Tung Sol 5687WA and Siemens 5687WB sound similar but also the inner construction looks similar. The RCAs are a bit noisier but also sound differently, not bad at all though. If we had more experience with these tubes, we might be able to nail down the 6N6P-IR successor to go with 6HM5, C3G or double triodes with breadboard adapter.
  
 And for everyone who is reading this thread from the beginning also, power tubes do more than a 10% difference and that's why it is good to find better ones (IMO).


----------



## Acapella11

trolldragon said:


> What you might want to do is start a "New Little Dot Tube Rolling" thread with updated information and have an administrator close this thread and put a forward link at the end to the new thread.
> 
> That way you could start a new updated thread and possibly a Wiki for all the new LD users.
> 
> Just my 2 peso's


 
  
 Brilliant idea. I actually started a new table, lol...


----------



## mordy

Hi Mikelap.
  
 To use a single 5687 as driver you need a breadboard and two 7pin Vector adapters. The 5687 runs on 6.3V, but can also be run on 12.6V. If you want to use 12.6V you also need a power supply and voltage regulator. The breadboard wiring is slightly different for 12V vs 6V operation.
  
 Gibosi has provided detailed wiring diagrams and tutorials in previous posts.


----------



## TrollDragon

mikelap said:


> I could use a single 5687 as driver how exactly .Thanks


 

 The 5687 draws 900mA of current in 6V heater configuration and 450mA in 12V,  so either way you would need a power supply in my opinion.


----------



## Oskari

trolldragon said:


> What you might want to do is start a "New Little Dot Tube Rolling" thread with updated information and have an administrator close this thread and put a forward link at the end to the new thread.
> 
> That way you could start a new updated thread and possibly a Wiki for all the new LD users.
> 
> Just my 2 peso's


 
  
 I can only agree. This is page 576 after all.
  
 Oops. Make that 577.


----------



## i luvmusic 2

So i received the Loctal sockets today and i'am trying to loosen the sockets so i can insert the C3g without too much downward pressure but the PoS loctal sockets is difficult to loosen.


----------



## gibosi

Received an RFT ECC813 in the mail today. This has the same pinout as the 6350 and 6463, but it appears that it was manufactured only by Radio-Funk-Technik. located in what was then East Germany, in the 1960's. These are somewhat rare, I don't see any on eBay at the moment, but there appears to be little demand, so they are not expensive. I paid less than $20 for this one, including shipping from Germany. And the good news is it lights up and plays.


----------



## Oskari

What RFT was short for, varied over the years.
  
 Regardless, that's the logo of the Erfurt factory.


----------



## mordy

Hi Gibosi,
  
 Checked on Ebay DE (Germany) now - four offers today of EEC813.


----------



## MIKELAP

i luvmusic 2 said:


> So i received the Loctal sockets today and i'am trying to loosen the sockets so i can insert the C3g without too much downward pressure but the PoS loctal sockets is difficult to loosen.


 
 What kind are they the same type as before


----------



## mordy

Hi TD,
  
_"The 5687 draws 900mA of current in 6V heater configuration and 450mA in 12V,  so either way you would need a power supply in my opinion." _You are 100% correct, as a driver the 5687 needs an external power supply in 6V mode as well.
  
 This is easy to do; any wall wart rated 1 1/2A or so will do, and voltage regulators for up to 5A are very inexpensive. The heater wires are connected to the voltage regulator, and the other leads from the breadboard with the 9pin socket are configured for each of the two Vector adapters. The only tools needed are cutting pliers and a small flat blade screwdriver.


----------



## TrollDragon

mordy said:


> Hi TD,
> 
> _"The 5687 draws 900mA of current in 6V heater configuration and 450mA in 12V,  so either way you would need a power supply in my opinion." _You are 100% correct, as a driver the 5687 needs an external power supply in 6V mode as well.
> 
> This is easy to do; any wall wart rated 1 1/2A or so will do, and voltage regulators for up to 5A are very inexpensive. The heater wires are connected to the voltage regulator, and the other leads from the breadboard with the 9pin socket are configured for each of the two Vector adapters. The only tools needed are cutting pliers and a small flat blade screwdriver.


 

 Hi mordy,
  
 Excellent info for those that want to use this tube as a driver. I don't think MIKELAP was looking to use an external power supply though, but I could be wrong.


----------



## hypnos1

i luvmusic 2 said:


> So i received the Loctal sockets today and i'am trying to loosen the sockets so i can insert the C3g without too much downward pressure but the PoS loctal sockets is difficult to loosen.


 
  
 Hi ilm2.
  
 Yes, whatever you do you MUST loosen those sockets lol!!...I presume they're the 'split circle' type and not the 'rolled jaw' (Russian) type that MIKELAP showed recently. If so, I found no problem using a small 1.5mm flat blade screwdriver - with the flats across the solid walls of the circle just keep working in and out until it does so fairly easily. I then found the tubes would go in straight without the need for _too_ much force, but enough to give a good contact.
 So hopefully you should be able to do the same...
	

	
	
		
		

		
		
	


	




...and GOOD LUCK!


----------



## gibosi

trolldragon said:


> What you might want to do is start a "New Little Dot Tube Rolling" thread with updated information and have an administrator close this thread and put a forward link at the end to the new thread.
> 
> That way you could start a new updated thread and possibly a Wiki for all the new LD users.
> 
> Just my 2 peso's


 
  
 I agree that this is a great idea. Now we just have to find someone who would be willing to take on this task. And on the chance someone points at me, I have just started a new job, still in training and no spare time....
  
 Cheers


----------



## TrollDragon

gibosi said:


> I agree that this is a great idea. Now we just have to find someone who would be willing to take on this task. And on the chance someone points at me, I have just started a new job, still in training and no spare time....
> 
> Cheers


 
 You good sir, would actually be the best candidate for this exalted position. Your tube knowledge and activity in this thread is top-shelf and I can't think of anyone else who would be your equal.
  
 So no rush, it would be a good project in the new year after all the hustle and bustle of the season and your new job has calmed down.


----------



## MIKELAP

trolldragon said:


> mordy said:
> 
> 
> > Hi TD,
> ...


 
 Your right on that TD just looking for plug n play tubes as i use my other amps for similar tubes but thanks anyways.


----------



## mordy

Hi,
  
 Not long ago one post mentioned that as a rule tubes made in the late 70's and 80's usually aren't as well made as earlier tubes. This seems to be correct, but there are exceptions to every rule. From what I read Philips tubes (after they bought out Sylvania) made in those years kept the quality up.
  
 Saw some 6080 tubes available for a low price and bid. These two auctions ended Saturday night so I was hoping that people would be too busy to bid - won 4 tubes for less than $3 each.
  
 Two were Philips (Sylvania), one Sylvania and one GE. The GE tube has the distinction of being the youngest tube in my collection:
  

  

 There are two dates on this tube - 52nd week 1987 and 38th week 1987. I assume that one is manufacturing date and the later date shipping date. Under the later date are the numbers 33173. Does anybody know what they mean?


 This is the other side of the tube. Saw somewhere that the (in)famous GE dots had been deciphered but could not find any information. Anybody?
  
 Lastly, each of the four tubes has what looks like a white fabric band around the tube extending into the base (see first picture). Anybody knows what it is?
  
 As I am writing this I am listening to the pair of Philips 80's tubes. They sound very similar to my 60's Sylvania tubes, and they sound very good.


----------



## genclaymore

Any one here wouldn't happen to know the best setting to set the gain to on the little dot MK2 2.0 for the Hifiman HE-500.


----------



## MIKELAP

mordy said:


> Hi,
> 
> Not long ago one post mentioned that as a rule tubes made in the late 70's and 80's usually aren't as well made as earlier tubes. This seems to be correct, but there are exceptions to every rule. From what I read Philips tubes (after they bought out Sylvania) made in those years kept the quality up.
> 
> ...


 
  I have a pair of Sylvania 6AS7GA with the fabric ,but dont know year of manufacture  anybody .


----------



## sgbwill2

mordy said:


> Hi,
> 
> Not long ago one post mentioned that as a rule tubes made in the late 70's and 80's usually aren't as well made as earlier tubes. This seems to be correct, but there are exceptions to every rule. From what I read Philips tubes (after they bought out Sylvania) made in those years kept the quality up.
> 
> ...


 
 I recently purchased a NOS matched pair of Thomson-CSF 6080WA's manufactured in France. They sound amazing in my La Figaro 339 and many regard them as one of the better 6080 tubes other than the 6080WB Bendix graphite plates that is which fetch an insane price.


----------



## gibosi

trolldragon said:


> You good sir, would actually be the best candidate for this exalted position. Your tube knowledge and activity in this thread is top-shelf and I can't think of anyone else who would be your equal.
> 
> So no rush, it would be a good project in the new year after all the hustle and bustle of the season and your new job has calmed down.


 
  
 Thank you for the kind words and I will think about it... But again, for now, no time....
  
 And I wonder.... If we do decide to create a new thread, maybe it should be called something like "Extreme Little Dot Tube Rolling" to emphasize that all the tubes under discussion in this new thread, even the 6DT6 and the 6HM5, are extreme departures from the traditional tubes recommended by the Little Dot company.
  
 And maybe the current thread should be left open for those who wish to discuss the pros and cons of EF91, EF92 and EF95....


----------



## gibosi

mordy said:


> Not long ago one post mentioned that as a rule tubes made in the late 70's and 80's usually aren't as well made as earlier tubes. This seems to be correct, but there are exceptions to every rule. From what I read Philips tubes (after they bought out Sylvania) made in those years kept the quality up.
> 
> .......
> 
> As I am writing this I am listening to the pair of Philips 80's tubes. They sound very similar to my 60's Sylvania tubes, and they sound very good.


 
  
 My hunch is that while the small signal tubes were replaced early on by solid state devices, other tubes, such as the sub-miniatures and power supply voltage regulators like the 6080 could not easily be replaced by the solid state devices available in the 1980s. And therefore, while the small signal tubes were being manufactured as cheaply as possible, solely to keep old tube gear running, tubes like the 6080 were still state-of-the-art and manufacturing quality remained high.


----------



## MIKELAP

gibosi said:


> trolldragon said:
> 
> 
> > You good sir, would actually be the best candidate for this exalted position. Your tube knowledge and activity in this thread is top-shelf and I can't think of anyone else who would be your equal.
> ...


 
 Because getting to where we are now  was fun  to.


----------



## Acapella11

mikelap said:


> Because getting to where we are now  was fun  to.


 
  
 Of course, you shouldn't need to buy 50 pairs of tubes before you buy the 6HM5s but the journey through all the tubes taught me a lot about what I like and to express my impressions. Besides, that the LD MKIII / IV sounds amazingly good for its price, the big advantage of the LD MKIII / IV is that you can try a lot of different sound signatures on a low budget.
 For me it was to some extend like Confucius said: "The journey is the goal."


----------



## mordy

Hi sgbwill2,
  
 It doesn't have to be that the most expensive tubes have a monopoly on good sound. Glad you enjoy the Thompson 6080s. Am I the only one who enjoys $3.00 Sylvania/Philips 6080WA/WC tubes?
  
 Maybe somebody wants to take a chance on a pair of these.... I don't think you will be disappointed.


----------



## mordy

Just saw over on  the Feliks thread that hypnos1 ordered a pair of Syls 6080. Let's see if I am just imagining or not.....


----------



## hypnos1

mordy said:


> Hi sgbwill2,
> 
> It doesn't have to be that the most expensive tubes have a monopoly on good sound. Glad you enjoy the Thompson 6080s. Am I the only one who enjoys $3.00 Sylvania/Philips 6080WA/WC tubes?
> 
> Maybe somebody wants to take a chance on a pair of these.... I don't think you will be disappointed.


 

 Hi m.
  
 $3 Sylvania 6080s?...There sure don't look many about for that kind of money now, lol!!...But then, you ARE the Master of the bargain tube...


----------



## sgbwill2

mordy said:


> Hi sgbwill2,
> 
> It doesn't have to be that the most expensive tubes have a monopoly on good sound. Glad you enjoy the Thompson 6080s. Am I the only one who enjoys $3.00 Sylvania/Philips 6080WA/WC tubes?
> 
> Maybe somebody wants to take a chance on a pair of these.... I don't think you will be disappointed.


 
 The Thompsons after just having them a few hours have become faulty somehow after I switched my amp off and returned to it a few hours later. They suddenly now only play at 1/10 the volume they originally did. I switched to my rca 6as7's and they play at normal volumes so fortunately its not the amp. Will be returning them soon I guess for a refund or replacements. I'm sure the sylvania/philips sound great, though the expensive bendix 6080wb's supposedly are the kings of 6080's. Would like to try some sometime, but not at the current prices .


----------



## gibosi

sgbwill2 said:


> ................. I'm sure the sylvania/philips sound great, though the expensive bendix 6080wb's supposedly are the kings of 6080's. Would like to try some sometime, but not at the current prices .


 
  
 And some think the GEC 6080's are as good or better than the Bendix. And some think the TS and/or Syl 7236 are as good or better. Too many tubes to try and not enough time and/or money to try them all... lol


----------



## i luvmusic 2

mikelap said:


> i luvmusic 2 said:
> 
> 
> > So i received the Loctal sockets today and i'am trying to loosen the sockets so i can insert the C3g without too much downward pressure but the PoS loctal sockets is difficult to loosen.
> ...


 
 Yes it's this.

  
  


hypnos1 said:


> i luvmusic 2 said:
> 
> 
> > So i received the Loctal sockets today and i'am trying to loosen the sockets so i can insert the C3g without too much downward pressure but the PoS loctal sockets is difficult to loosen.
> ...


 
 I've tried and still tight i guess i need to work it more.
 It's this type.
 THANKS GUYS!


----------



## i luvmusic 2

Hey guys,
   I think i found the problem with those Chinnee Loctal sockets,They are tight on the SHIELD PIN SLOT not on the Tube pin slots.Instead of loosening the Tube pin slot i widen the Shield pin slot with a small needle nose pliers and it works,mostly it's tight in the bottom part of the shield slot so make sure to widen/spread  it out as much as possible without splitting the ceramic.


----------



## i luvmusic 2

Hopefully i can wire up my C3g tomorrow.


----------



## MIKELAP

i luvmusic 2 said:


> Hey guys,
> I think i found the problem with those Chinnee Loctal sockets,They are tight on the SHIELD PIN SLOT not on the Tube pin slots.Instead of loosening the Tube pin slot i widen the Shield pin slot with a small needle nose pliers and it works,mostly it's tight in the bottom part of the shield slot so make sure to widen/spread  it out as much as possible without splitting the ceramic.


 
 You just reminded me ,I had to do this also


----------



## MIKELAP

If i ever get my other copper reducers ill use my russian sockets those work very well been waiting 3 weeks for the fittings none in stock .but those chinease sockets work well no issues after several weeks


----------



## hypnos1

i luvmusic 2 said:


> Hey guys,
> I think i found the problem with those Chinnee Loctal sockets,They are tight on the SHIELD PIN SLOT not on the Tube pin slots.Instead of loosening the Tube pin slot i widen the Shield pin slot with a small needle nose pliers and it works,mostly it's tight in the bottom part of the shield slot so make sure to widen/spread  it out as much as possible without splitting the ceramic.


 
  
 Yes indeed ilm2...that's why I showed in my adapter tutorial how to alleviate that problem, and also prevent the spigot holding the tube like grim death when fully inserted, lol!
  
 Hope all is well when it's "all systems go" with the C3Gs  
	

	
	
		
		

		
			





...
  
 ps. Even when this centre problem is sorted the tube socket connectors STILL need loosening in most cases...


----------



## ToTje

Well, my Voshkod 6ZH1P-EV tubes finally arrived today.
 I replaced my old tubes with them and gave them a try,
 Horrible crackling at first, but they of course still needed to warm up and burn in.
 The highs sounded like I was listening to 96kbit MP3s, but already I noticed a huge difference with my old tubes: the sound was much fuller/richer, the instrument separation and soundstage were improved and the bass was quite a lot deeper and stronger!
 With one song I found the bass a bit too overpowering even, since the bassguitar only had a supporting role in that song, and now it draws the attention too much.
  
  
 Other than that: WOW!
 I've read the name Jcques Loussier somewhere as a recommendation for good music, so I looked him up on YouTube.
 I tried this video out: https://www.youtube.com/watch?v=-x6jzKpqeuw
 After 22 seconds I took my LCD-X off, because I was quite certain I left my speakers with 30cm active woofers on and I was hearing that bass  through my headphones.

 As soon as I took them off, I realized the Vokshods were causing this incredible sound. Okay, while I am typing this line, a few seconds before the 11th minute of that vid, my eyes opened up wide again!
  
  
 Big, BIG recommendation, these $3 a pair -tubes! 
	

	
	
		
		

		
		
	


	




 The crackling has gone completely by now and the highs have smoothed out as well.
  
  
 EEK! Now somebody is coughing in my kitchen! (And I live alone! 
	

	
	
		
		

		
		
	


	




 ) I never thought I'd have this kind of soundstage with my LCD-X!


----------



## MIKELAP

If anybody is interested in loctal sockets the guy in Russia i bought mine from has them in stock again but this time they are $6.50 each instead of $4.50 each +$7.50 shipping .                                                                                                                                                                   http://www.ebay.com/itm/Ceramic-Loctal-8-B8G-Sylvania-1938-socket-12G1L-12P17L-2G27L-2P29L-4P1L-/381087439551?


----------



## ToTje

Hmm I do hear a soft but constant buzz with these tubes. Especially at silences it's very noticeable.


----------



## gibosi

totje said:


> Hmm I do hear a soft but constant buzz with these tubes. Especially at silences it's very noticeable.


 
  
 Run them for 20 to 30 hours. This is called "burning in." It is very common for new tubes to be a bit noisy, but most quiet down after burning in.


----------



## ToTje

gibosi said:


> Run them for 20 to 30 hours. This is called "burning in." It is very common for new tubes to be a bit noisy, but most quiet down after burning in.


 

 Ah right, I knew sound quality would improve with burning in; smoother highs, tighter bass etc, but I didn't know new tubes also could have a buzz and that that would go away with burning in. 
	

	
	
		
		

		
		
	


	




 Thx! 
	

	
	
		
		

		
		
	


	




 I didn't have any buzzing sounds with the old tubes though.


----------



## Acapella11

totje said:


> Well, my Voshkod 6ZH1P-EV tubes finally arrived today.
> I replaced my old tubes with them and gave them a try,
> Horrible crackling at first, but they of course still needed to warm up and burn in.
> The highs sounded like I was listening to 96kbit MP3s, but already I noticed a huge difference with my old tubes: the sound was much fuller/richer, the instrument separation and soundstage were improved and the bass was quite a lot deeper and stronger!
> ...




Thank you for sharing your impressions. The even better news is that there are a few more excellent tubes ahead of you, which will probably surprise you again and again. 

It feels refreshing to hear some initial "old school" tube impressions.


----------



## ToTje

acapella11 said:


> Thank you for sharing your impressions. The even better news is that there are a few more excellent tubes ahead of you, which will probably surprise you again and again.
> 
> It feels refreshing to hear some initial "old school" tube impressions.


 

 Heh cool! 
	

	
	
		
		

		
		
	


	



 Yeah I want to try out the tubes that score high in the first 5 posts of this topic. I also have read that the Voskhod 6sch1p-EV is even a bit better than this one, and I've seen very cheap ones of that as well, so I think I'll try that out some day as well.


----------



## Acapella11

The 6sch1P-EV are the same as the 6ZH1P-EV, it happens that ZH is spoken like a hard sounding 'sh'. 
If you don't want order a pair if 6HM5 large bottle straight, I would suggest a pair of Tung Sol 6485 and have a look at page 77.


----------



## ToTje

acapella11 said:


> The 6sch1P-EV are the same as the 6ZH1P-EV, it happens that ZH is spoken like a hard sounding 'sh'.
> If you don't want order a pair if 6HM5 large bottle straight, I would suggest a pair of Tung Sol 6485 and have a look at page 77.


 

 Really? LOL 
	

	
	
		
		

		
		
	


	



 Well perhaps there's a difference between golden grid versions and others then: http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/330#post_8413891
 Anyway, same or not; I guess they're very similar at least. 
  
 Thx for the tip, will check!


----------



## i luvmusic 2

WOW!This C3g took the LD amp in different level.


----------



## kephansting

I'm in need of some help. I recently purchased the i+ off Amazon with the WE408A tube upgrade. After some research and time spent listening, I decided to roll in EI 6HM5 tubes that I purchased from tubes.rs out of Serbia. There are many posts on this site about this seller, and I am assured they are reputable. After putting these tubes in, however,  there is an incredibly loud humming noise that is extremely intrusive all the time. People on this site tend to think this problem is caused by:

 A) Unmatched tubes (the seller guaranteed they are matched)
 B) Defective tubes (the seller guaranteed they were tested)
 or
 C) Incorrect EF setting

 I cannot seem to figure out how to identify which mode it came in with the 408A tubes. I know the 6HM5 are intended to be run in EF95 mode. So, my question is:

 A) How do I tell which EF setting my amp is currently set to?
 and
 B) What steps are involved in switching to the EF95 setting if it is not already?


----------



## tjw321

kephansting said:


> I'm in need of some help. I recently purchased the i+ off Amazon with the WE408A tube upgrade. After some research and time spent listening, I decided to roll in EI 6HM5 tubes that I purchased from tubes.rs out of Serbia. There are many posts on this site about this seller, and I am assured they are reputable. After putting these tubes in, however,  there is an incredibly loud humming noise that is extremely intrusive all the time. People on this site tend to think this problem is caused by:
> 
> A) Unmatched tubes (the seller guaranteed they are matched)
> B) Defective tubes (the seller guaranteed they were tested)
> ...


 
 I don't have the I+ but there's a link to the I+ user guide at the bottom of this page:
  
http://www.littledot.net/forum/viewtopic.php?f=9&t=819&sid=75669282daed018b3745603545ed5719
  
 I think that will have (some of) the information you need.


----------



## MIKELAP

kephansting said:


> I'm in need of some help. I recently purchased the i+ off Amazon with the WE408A tube upgrade. After some research and time spent listening, I decided to roll in EI 6HM5 tubes that I purchased from tubes.rs out of Serbia. There are many posts on this site about this seller, and I am assured they are reputable. After putting these tubes in, however,  there is an incredibly loud humming noise that is extremely intrusive all the time. People on this site tend to think this problem is caused by:
> 
> A) Unmatched tubes (the seller guaranteed they are matched)
> B) Defective tubes (the seller guaranteed they were tested)
> ...


 
  
 Edited


----------



## TrollDragon

kephansting said:


> I'm in need of some help. I recently purchased the i+ off Amazon with the WE408A tube upgrade. After some research and time spent listening, I decided to roll in EI 6HM5 tubes that I purchased from tubes.rs out of Serbia. There are many posts on this site about this seller, and I am assured they are reputable. After putting these tubes in, however,  there is an incredibly loud humming noise that is extremely intrusive all the time. People on this site tend to think this problem is caused by:
> 
> A) Unmatched tubes (the seller guaranteed they are matched)
> B) Defective tubes (the seller guaranteed they were tested)
> ...


 

 The WE408A has a 20 Volt heater and the 6HM5's have a 6.3Volt heater. I would NOT plug the 6HM5's in again until you have the jumpers/switches moved on the LD I+. Hopefully you didn't burn out the 6HM5 heaters.
  

 Make sure both switches are set to 6J1 and the EF92 jumpers are off.


----------



## Oskari

mordy said:


> Saw somewhere that the (in)famous GE dots had been deciphered but could not find any information. Anybody?


 
  
 Apparently Tube Collector magazine Dec 2010 has the information.
  

http://www.tubecollectors.org/tcoll2010.htm


----------



## kephansting

trolldragon said:


> Make sure both switches are set to 6J1 and the EF92 jumpers are off.


 

 This was it. The EF92 jumpers were off, but it was not set to 6J1. I must have a hardware refresh, because there are no switches to make this change. My model uses jumpers. A million thanks to you, good sir!


----------



## ToTje

Man, these Voshkod 6ZH1P-EV's are incredible with pianos and snare instruments!
 Vocals seem a little bit recessed compared to those instruments though.
  
 However, they're still nowhere near burned in.


----------



## gibosi

I know that many of you have been on the edge of your seats to learn more about the 6350/6463/ECC813 family of tubes. Yes?? lol 
  
 I was able to spend a little time with the RFT ECC813 (left) and the Telefunken 6463 (right). It is interesting to note just how similar the internal construction is.
  

  
 Listening to highly produced music, such as Lorde (Pure Heroine) and James Blake (Overgrown) these tubes sounded very similar to me, and very good. However, when I switched to more natural music, just vocals and real instruments, such as Holly Cole (NIGHT), John Boutte (Stew Called New Orleans) and Nora Jones (Come Away With Me), I noticed a slight difference in the midrange. The RFT has just a bit more emphasis in the upper mid range, vocals have a slight edge to them. And as my headphones (HD700) are already fairly bright, I prefer the Telefunken in my system.
  
 After deciding that I preferred the Telefunken, I chilled out and listened to a recent discovery and a current favorite, Field Report (Marigolden), and was struck with this tube's superb transparency and precise imaging. I really like this tube. And I hope to be able find some time soon to compare it to a couple of 6350s, a Sylvania and an RCA. Also, Philips manufactured the 6463 in their Hamburg plant, but have yet to come across one at a price I am willing to pay.  Patience.....  
  
 Again, for those of you who are new to eXtreme LD tube rolling, I am using this double triode as a driver in my LD 1+ (with MUSES02 opamp), and in order to do so, mods are absolutely necessary.


----------



## i luvmusic 2

gibosi said:


> I know that many of you have been on the edge of your seats to learn more about the 6350/6463/ECC813 family of tubes. Yes?? lol
> 
> I was able to spend a little time with the RFT ECC813 (left) and the Telefunken 6463 (right). It is interesting to note just how similar the internal construction is.
> 
> ...


 
 Hi gibosi,
   Will these tubes comparable/close to the sound of C3g's?I just started using C3g's last night and these tubes blown me away.THANKS!


----------



## i luvmusic 2

Many thanks to Superdux for sharing the C3g's with me.


----------



## i luvmusic 2




----------



## superdux

nice adapter! What kind of power tubes do you have installed?


----------



## i luvmusic 2

Sylvania 6SN7 GTB.
  
 THANKS!


----------



## superdux

I also have some NOS chinese 6SN7 as power tubes.The sound is incredible in combination with the C3G but its still burning in and i think its a hidden gem.


----------



## gibosi

> Originally Posted by *i luvmusic 2* /img/forum/go_quote.gif
> 
> Will these tubes comparable/close to the sound of C3g's?I just started using C3g's last night and these tubes blown me away.THANKS!


 
  
 In my opinion, yes. While I haven't directly compared them, I feel that I know the C3g's sound fairly well and to my ears, the Telefunken 6463's are not lacking. But again, this is all very subjective, my ears and my gear.
  
 To my mind, there is no one "best" tube that is head-and-shoulders above all the others. The goal of the C3g designers was to create a pentode that would sound as good as a top-tier double triode when strapped. And there are a number of comparable top-tie double triodes, all equally good, but each slightly different. Depending on one's ears and gear, one of these might be preferable to the others, but it is not necessarily better. And in my mind, the Telefunken 6463 is right up there with the best of them.


----------



## i luvmusic 2

How long does it need to burn-in the C3g's?I have mine running for at least 12hrs since last night i can't stopped listening my A55 is glued to my chair right now.


----------



## i luvmusic 2

gibosi said:


> > Originally Posted by *i luvmusic 2* /img/forum/go_quote.gif
> >
> > Will these tubes comparable/close to the sound of C3g's?I just started using C3g's last night and these tubes blown me away.THANKS!
> 
> ...


 
 THANK YOU!


----------



## hypnos1

i luvmusic 2 said:


> How long does it need to burn-in the C3g's?I have mine running for at least 12hrs since last night i can't stopped listening my A55 is glued to my chair right now.


 
  
 Hi ilm2. Glad you're loving your C3gs...they get even better, lol! - up to 50hrs plus!!  
	

	
	
		
		

		
		
	


	



  
 So keep enjoying


----------



## i luvmusic 2

hypnos1 said:


> i luvmusic 2 said:
> 
> 
> > How long does it need to burn-in the C3g's?I have mine running for at least 12hrs since last night i can't stopped listening my A55 is glued to my chair right now.
> ...


 
 Sure i will,THANKS!


----------



## mordy

Hi,
  
 Here is another C3g style tube, 18V 0.2A - The Philips Miniwatt 18040. I am not sure about the pinout - waiting for Gibosi to weigh in.


----------



## bbmiller

> gibosi said:
> 
> 
> > To my mind, there is no one "best" tube that is head-and-shoulders above all the others. The goal of the C3g designers was to create a pentode that would sound as good as a top-tier double triode when strapped. And there are a number of comparable top-tie double triodes, all equally good, but each slightly different. Depending on one's ears and gear, one of these might be preferable to the others, but it is not necessarily better. And in my mind, the Telefunken 6463 is right up there with the best of them.


 
 Which is the least expensive of the ones that are right up there with the best of them?


----------



## stacker45

I have a Little Dot 1+, that still has the stock tubes. I want to upgade them , but since I'm clumsy, I don't want to have to fiddle with the little switches Inside.
  
 I want to know if the Voshkod 6ZH1P-EV, is a direct replacement, and I'm open to suggestions, so feel free...
  
 Oh!, and I don't know if this is relevant, but I'm from the ''Dark Side'', meaning I'm a Grado owner.


----------



## ToTje

stacker45 said:


> I have a Little Dot 1+, that still has the stock tubes. I want to upgade them , but since I'm clumsy, I don't want to have to fiddle with the little switches Inside.
> 
> I want to know if the Voshkod 6ZH1P-EV, is a direct replacement, and I'm open to suggestions, so feel free...
> 
> Oh!, and I don't know if this is relevant, but I'm from the ''Dark Side'', meaning I'm a Grado owner.


 
 I just bought those Voshkods and they're plug and play. 

 The sound with those goes deep, and I mean DEEP!!!!


----------



## stacker45

totje said:


> I just bought those Voshkods and they're plug and play.
> 
> The sound with those goes deep, and I mean DEEP!!!!


 
  
 Thanks, Graos aren't  known for their bass exensin, so that's a good thing.


----------



## gibosi

stacker45 said:


> I have a Little Dot 1+, that still has the stock tubes. I want to upgade them , but since I'm clumsy, I don't want to have to fiddle with the little switches Inside.
> 
> I want to know if the Voshkod 6ZH1P-EV, is a direct replacement, and I'm open to suggestions, so feel free...
> 
> Oh!, and I don't know if this is relevant, but I'm from the ''Dark Side'', meaning I'm a Grado owner.


 
  
 You can purchase the LD1+ with either 6J1, EF92 or 408A. And therefore, the answer to your question depends on which of these tubes were installed in your amp when you purchased it. As the amp costs a bit more with the EF92 and 408A, it is likely your amp came with 6J1. And if so, the 6ZH1p-EV is a direct replacement. But if your amp came with EF92 or 408A, it is absolutely necessary to change the internal jumpers.


----------



## gibosi

mordy said:


> Hi,
> 
> Here is another C3g style tube, 18V 0.2A - The Philips Miniwatt 18040. I am not sure about the pinout - waiting for Gibosi to weigh in.


 
  
 Unfortunately, this tube has a different pinout than the C3g, so it is likely that you would have to build custom adapters to use this in an LD.....


----------



## gibosi

bbmiller said:


> Which is the least expensive of the ones that are right up there with the best of them?


 
  
 As double triodes and the C3gs are not natively compatible with the LD, it seems to me that in order to make this price comparison, it is necessary to add in the cost of any adapters and/or mods required to run them. Further, coming up with prices is difficult because the cost of tubes is all over of the place. Case in point, I recently purchased a very early Tung-Sol VT231/6SN7GT for only $22. I have seen this tube go for over $200 on eBay. Perhaps the best way to estimate prices is to search the sold listings to determine what people have actually been willing to pay. But from my experience, the most important factor is patience. If you are willing to wait, sometimes good deals will fall in your lap. 
  
 A pair of C3g's typically runs about $70, but the additional cost of the adapters brings the cost up to around $125.00. Further, so far, these adapters will work for no other tube that I am aware of..... 
  
 Top-tier double triodes can cost anywhere from a few dollars to hundreds of dollars and even more. Further, it is necessary to factor in the cost of the various mods necessary to run them. That said, once you have these mods in place, you can easily run any double triode. So one might say that the cost of the mods can be spread over as many tubes as you decide to purchase. The prices I paid for these mods totals about $40 for a 9-pin breadboard socket, 2 Vector 7-pin test sockets, a 4.5A laptop power supply and a step-down voltage regulator. And it is possible to purchase these mods for considerably less as Mordy has demonstrated. If you wish to run 6SN7's you would need to purchase an octal to 9-pin adapter for about $15.
  
 In my opinion, top-tier double triodes might include Tung-Sol VT231, Sylvania 6SN7W, Gray National Union 6SN7GT (and a few other 6SN7GT's as well), Bendix and Sylvania 3C51, various Philips E88CC and E188CC, 1975 Voskhod and Reflektor 6N32P, 1950's E80CC, 1950's ECC40, Sylvania and Tung-Sol 5687WA and most recently, Telefunken 6463. I have paid anywhere from $5 to $70 for each of these tubes. So again, with the prices on eBay being so variable, it is hard to say which tube is the least expensive.
  
 In my opinion, if you are set up to run double triodes, the "world is your oyster". And the icing on the cake is you can still run C3gs if you want.


----------



## David.M

Gibosi/Mordi
  
 What do you guys think about the 6HM5 Yugo and the 6N6P-IR Gold Grid Combination?
  

 How would the Mullard M8100 compare to the Yugo?


 The Voshkod 6N23P are decent as power tubes, but i find them a little bright and too detailed. 
  
  I'm looking for something airy, warm,  with intact/full bodied  vocals, with improved bass and separation response that will compliment both the Senn HD600's and the beyer dt990's.
  
 Just needing a second opinion, thanks.
  
 I think, that's pretty much it for the plug and play. Next step after that will be modding the resistors/circuits and what-not, so your amp looks like a damn  octopus :I


----------



## Acapella11

david.m said:


> Gibosi/Mordi
> 
> What do you guys think about the 6HM5 Yugo and the 6N6P-IR Gold Grid Combination?
> 
> ...


 
 My 2 c: Excellent combo. Haven't compared those for a long time but from the top of my head, you get more detail, treble extension and tighter bass and definitely more transparency. The 6N6P-IR are reasonably warm. Warmer than 6H30P tubes, while the Yugo 6HM5 are more on the neutral side.


----------



## gibosi

david.m said:


> I think, that's pretty much it for the plug and play. Next step after that will be modding the resistors/circuits and what-not, so your amp looks like a damn  octopus :I


 
  
 My LD1+ uses an op amp as an output device instead of tubes, so I will defer to others....  However, I encourage you to try 5687's as output tubes. While the 6N23P excels as a driver, it just doesn't have enough "power" to be a good power tube. The 5687 has "power" similar to the 6N6P/6N30P types, and with a simple pin-adapter, you have more rolling options: RCA, Sylvania, Tung-Sol, Raytheon, GE and Thomson.
  
 And you think my Little Monster Dot looks like an octopus? lol


----------



## Johnnysound

david.m said:


> Gibosi/Mordi
> 
> What do you guys think about the 6HM5 Yugo and the 6N6P-IR Gold Grid Combination?
> 
> ...


 
 I agree with Acapella11, excellent combo.  Just used it recently:  6HM5 Yugos with 6N6P (not IR version but good 78´ gold grid)   and the 6HM5 neutrality, presence and deep bass complement very nicely with the 6N6P "tight" bass and extended highs presentation, along with a touch of warmth...


----------



## Acapella11

gibosi said:


> My LD1+ uses an op amp as an output device instead of tubes, so I will defer to others....  However, I encourage you to try 5687's as output tubes. While the 6N23P excels as a driver, it just doesn't have enough "power" to be a good power tube. The 5687 has "power" similar to the 6N6P/6N30P types, and with a simple pin-adapter, you have more rolling options: RCA, Sylvania, Tung-Sol, Raytheon, GE and Thomson.
> 
> And you think my Little Monster Dot looks like an octopus? lol


 
  
 And I encourage to roll 5687 tubes also


----------



## mordy

Hi David. M
  
 Based on my own experience with power tubes, the 6SL7 and 6SN7 octal tubes are better than the 6N6P-IR. There is more weight and heft, the 6SL7 being a little lighter and quicker in presentation.
  
 I haven't yet tried the 5687 as power tubes, but those who have used them claim that they sound better than the 6SN7. This is not surprising to me, given how good the 5687 sounds as a driver tube.
  
 The above tubes are plug and play with the appropriate adapters.
  
 The next step up for the Little Dot MKIII/IV would involve more adapters to run the C3g as driver tubes, and adapters, socket extenders (MKIII) and an external power supply with a 15A voltage regulator to use 2.5A power tubes (6AS7/6080).


----------



## mordy

Hi David.M,
  
 Just wanted to add one more thing. You write that the Voskhod 6N23P sounded too detailed. My understanding is that you mean that the tube is to analytical, etched. The opposite would be musical, warm etc.
  
 In general, it is very difficult to find a tube that has both qualities, both analytical and musical. IMHO the best tubes combine these virtues, in addition to reproducing the entire sound spectrum clearly and equally well in the bass, mid range and treble with a wide sound stage.
  
 Sounds like a tall order, but it is possible to approximate this level. However, it requires a synergy between the power tubes and the driver tubes as well. Throw in factors such as your equipment, taste (and hearing), and you can get varied opinions. However, you can arrive at a consensus which tubes are in the best category.
  
 The members of this forum have investigated and researched these choices, and their collective advice is very valuable. Read the blog, from the most recent posts and backwards in time, to get the knowledge of which tubes work the best in the LD amps.
  
 Good Luck!


----------



## Nic Rhodes

You also should try the E182CC as an output tube. Very different presentation style to the 5687 [I actually have another amp that uses both]. LD may have even started out with this tube!


----------



## gibosi

nic rhodes said:


> You also should try the E182CC as an output tube. Very different presentation style to the 5687 [I actually have another amp that uses both]. LD may have even started out with this tube!


 
  
 Yes! 
  
 The E182CC has the same pinout as the 5687, so if you are using, or plan to use the 5687, you can use the same adapter. Like the Philips E88CC/6922 and E188CC/7308, this tube was manufactured both in Heerlen, Holland, and in Hicksville, L.I., NY, and I find it to have a similar sonic signature. In Europe, it was marketed as E182CC and in the states, 7119.
  
 And in addition to the 5687 and E182CC/7119, you might want to consider the 7044. As best I can tell, these were manufactured only in the US by the major American companies. I have not spent much time with the 7044 (used as a driver), but from what I have read, some consider it to be a tad bit drier than the American versions of 5687.
  
 Have fun!


----------



## Acapella11

nic rhodes said:


> You also should try the E182CC as an output tube. Very different presentation style to the 5687 [I actually have another amp that uses both]. LD may have even started out with this tube!


 
  


gibosi said:


> Yes!
> 
> The E182CC has the same pinout as the 5687, so if you are using, or plan to use the 5687, you can use the same adapter. Like the Philips E88CC/6922 and E188CC/7308, this tube was manufactured both in Heerlen, Holland, and in Hicksville, L.I., NY, and I find it to have a similar sonic signature. In Europe, it was marketed as E182CC and in the states, 7119.
> 
> ...


 
  
  
 Yes, yes, yes! Only the heater current is a bit low with 0.3 A for the ECC88.


----------



## Nic Rhodes

Thought we had been here before p285, post 4360 ish! 18 month ago I was push 5687 and E182CCs as output tubes1


----------



## gibosi

acapella11 said:


> Yes, yes, yes! Only the heater current is a bit low with 0.3 A for the ECC88.


 
  
 The ECC88, E88CC and E188CC all have a heater current of about 0.3A, similar to a 6N23P, so these are not well suited to be used as an output tubes.
  
 However, the E182CC draws about 0.64A so it could be at least as good as a 6SN7, which draws 0.60A. And with a sonic signature quite different than the American versions of the 5687 and 7044, I believe it is very definitely worth a try.


----------



## gibosi

nic rhodes said:


> Thought we had been here before p285, post 4360 ish! 18 month ago I was push 5687 and E182CCs as output tubes1


 
  
 Sometimes it takes a while for "pushes" to bear fruit.


----------



## MIKELAP

Nobody seem to know anything about this tube asked in several threads . This is not really the right thread but this is a last resort you might say .Does anybody know anything about a the U54 RECTIFIER is it as good as a U52 or is it different what would be sound signature of these . would appreciate any infos you guys might have . Thanks


----------



## sgbwill2

mikelap said:


> Nobody seem to know anything about this tube asked in several threads . This is not really the right thread but this is a last resort you might say .Does anybody know anything about a the U54 RECTIFIER is it as good as a U52 or is it different what would be sound signature of these . would appreciate any infos you guys might have . Thanks


 
 http://www.radiomuseum.org/tubes/tube_u54.html
 http://www.radiomuseum.org/tubes/tube_u52.html
  
 Those links are good for info on the tubes. As you can see they both run in 5V but the U54 draws up 2.8A and the U52 draws up 3.0A. Also the pinouts are different as you can see by the pictures. As for sound signature I have no idea; though I imagine they would sound similar but that's me guessing.


----------



## Oskari

U54 seems to be the MOV type code for the Mullard GZ37. So, who made the U54 in question? Mullard? Or is it perhaps the fat Cossor?


----------



## MIKELAP

oskari said:


> U54 seems to be the MOV type code for the Mullard GZ37. So, who made the U54 in question? Mullard? Or is it perhaps the fat Cossor?


 
 it is labelled as a GEC  made in 1961 i saw somewhere that bite marks on corners plates makes this a  Mullard possible you think


----------



## Oskari

It is a Mullard tube. 
	

	
	
		
		

		
		
	


	




 
  
 What's the etched code on it?


----------



## Oskari

sgbwill2 said:


> Also the pinouts are different as you can see by the pictures.


 
  
 One is indirectly heated and the other directly heated. That is what you can see.


----------



## MIKELAP

oskari said:


> It is a Mullard tube.
> 
> 
> 
> ...


 
 I dont know


----------



## MIKELAP

Got another one this one is suppose to be Mullard made Philips Miniwatt GZ32 also has same bite marks with RK 71 /B0E  .is it a Mullard .thanks


----------



## Oskari

Ok. The U54 is a Mullard. The shape of the bottle says so.


----------



## Oskari

mikelap said:


> Got another one this one is suppose to be Mullard made Philips Miniwatt GZ32 also has same bite marks with RK 71 /B0E  .is it a Mullard .thanks


 
  
 R71 B0E tells that it is a 1960 Blackburn Mullard GZ32.


----------



## MIKELAP

oskari said:


> mikelap said:
> 
> 
> > Got another one this one is suppose to be Mullard made Philips Miniwatt GZ32 also has same bite marks with RK 71 /B0E  .is it a Mullard .thanks
> ...


 
 Would it be a good deal at $50.00


----------



## Oskari

mikelap said:


> Would it be a good deal at $50.00


 
  
 Better than the Mullard-branded one at twice the price or so.


----------



## Nic Rhodes

Mike
  
 as others have said, definately a Mullard. It is more normally labelled GZ37 and in my favourite goto tube in GZ range. These are the tubes I turn to first for full wave rectifiers like this. These rectifiers are indirectly heated (as opposed to 5U4G type directly heated) to combat cathode stripping and therefore have a nice slow controlled warm up (as opposed to 5U4G American types). U54 is just the GEC number that was used by GEC / Cossor etc however they labelled many examples as theirs that Mullard made for them with this distinctive thin slim ST look (They made their own fatter bulb version which is brilliant and earlier). Mullard made a huge number of these especially in the 66 / 67 era for the military (CV378) that many have stockpiled. All the GZ30, 32, 33, 34 and 37 are fine rectifiers worth looking at further. Most have a Uxx number or something like 52KU or 53KU used when supplied / made by others. The only thing you need to watch with all of these full wave rectifiers is the capacitance limitations and that will determine the PSU design and where / how you can swap. Filament voltages are often less than 5U4Gs. The voltage drop of the U54 / GZ37 is a bit less than the 5U4G but more than a GZ34 / 5AR4. The GZ33 is also a very similar tube to the GZ37.


----------



## MIKELAP

nic rhodes said:


> Mike
> 
> as others have said, definately a Mullard. It is more normally labelled GZ37 and in my favourite goto tube in GZ range. These are the tubes I turn to first for full wave rectifiers like this. These rectifiers are indirectly heated (as opposed to 5U4G type directly heated) to combat cathode stripping and therefore have a nice slow controlled warm up (as opposed to 5U4G American types). U54 is just the GEC number that was used by GEC / Cossor etc however they labelled many examples as theirs that Mullard made for them with this distinctive thin slim ST look (They made their own fatter bulb version which is brilliant and earlier). Mullard made a huge number of these especially in the 66 / 67 era for the military (CV378) that many have stockpiled. All the GZ30, 32, 33, 34 and 37 are fine rectifiers worth looking at further. Most have a Uxx number or something like 52KU or 53KU used when supplied / made by others. The only thing you need to watch with all of these full wave rectifiers is the capacitance limitations and that will determine the PSU design and where / how you can swap. Filament voltages are often less than 5U4Gs. The voltage drop of the U54 / GZ37 is a bit less than the 5U4G but more than a GZ34 / 5AR4. The GZ33 is also a very similar tube to the GZ37.


 
 Thanks guys  for all  the infos on these tubes according to Woo i can use all those rectifiers. I ended up getting the Mullard made Philips Miniwatt gz32 will see how that sounds .  Thanks


----------



## Acapella11

Swapped the MKIII for an MKIVSE and the first thing I noticed was the size difference. The MKIVSE is substantially bigger than the MKIII, I would say at least double the volume. It also sounds different, somewhat harder and more neutral. Also, I noticed that, with the MKIII and and C3GS, I put the volume control to about 8.30 - 9.30 o'clock, whereas now I am at 11-12 o'clock.


----------



## TrollDragon

Gain Setting?


----------



## i luvmusic 2

acapella11 said:


> Swapped the MKIII for an MKIVSE and the first thing I noticed was the size difference. The MKIVSE is substantially bigger than the MKIII, I would say at least double the volume. It also sounds different, somewhat harder and more neutral. Also, I noticed that, with the MKIII and and C3GS, I put the volume control to about 8.30 - 9.30 o'clock, whereas now I am at 11-12 o'clock.


 
   Now that you mentioned the difference between this two amps it makes me wonder if the MK IV SE is comparable to the CRACK.
 IMO even i'am now using the C3g's sounds to me that the MK III still can't compete with the CRACK..


----------



## MIKELAP

acapella11 said:


> Swapped the MKIII for an MKIVSE and the first thing I noticed was the size difference. The MKIVSE is substantially bigger than the MKIII, I would say at least double the volume. It also sounds different, somewhat harder and more neutral. Also, I noticed that, with the MKIII and and C3GS, I put the volume control to about 8.30 - 9.30 o'clock, whereas now I am at 11-12 o'clock.


 
 Interesting, more neutral  you say, is that with the Senns and by the way nice aquisition .MK4 has different sound signature ,does that mean better sound quality


----------



## MIKELAP

The Littledot mk3 use a 1A fuse does anybody know if its a fast blo or slo blo fuse


----------



## TrollDragon

mikelap said:


> The Littledot mk3 use a 1A fuse does anybody know if its a fast blo or slo blo fuse


 

 Probably a fast blow which looks like just a wire inside.
  
 A slow blow fuse looks like this one.

 But check your fuse and see.


----------



## MIKELAP

trolldragon said:


> mikelap said:
> 
> 
> > The Littledot mk3 use a 1A fuse does anybody know if its a fast blo or slo blo fuse
> ...


 
 Thanks i checked mine is a thin wire so it would be a fast blo.Woo amps is like your picture a slo blo .Woo says you can use a 2A or 3 A fuse thats weird which one would you use . Thanks


----------



## TrollDragon

mikelap said:


> Thanks i checked mine is a thin wire so it would be a fast blo.Woo amps is like your picture a slo blo .Woo says you can use a 2A or 3 A fuse thats weird which one would you use . Thanks


 
 That is strange they say you can use a 2A or 3A...
 What is in it? I would stick with what is labeled on the amplifier or fuse socket or manual.


----------



## MIKELAP

trolldragon said:


> mikelap said:
> 
> 
> > Thanks i checked mine is a thin wire so it would be a fast blo.Woo amps is like your picture a slo blo .Woo says you can use a 2A or 3 A fuse thats weird which one would you use . Thanks
> ...


 
 i checked its a 3.15 A 250V.


----------



## mordy

Hi,
  
 Still fighting my hum problem from my PC. A long time ago there was a post on this forum about somebody who plugged in an isolation transformer between the wall outlet and his LD amp and claimed an improvement in sound.
  
 I found an inexpensive one and plugged it in between the wall outlet and the LD MKIII,  but did not notice any change in sound. Now I decided to try to plug it in between my PC and my wall outlet to see if it would reduce the hum.
  
 This is how the unit looks like: (mine looks a little better but it is used)
  




  
 Here are the specs:




  
 There is definitively less hum, but it has not gone away completely. However, I can play quite loud without objectionable hum (hum can only be noticed when I pause the music at loud levels). I did an A/B comparison with my laptop, playing the same song at the same time, switching sound sources. The laptop has less hum (on pause), but the sound from the laptop is thinner with less impact. The PC sounds better with a more fleshed out and fuller sound.
  
 I really have no idea about the electrical implications of what I am doing. It seems to me that this isolation transformer was used to clean up noise in telephone lines (echos of the C3g?):
  
 Have two questions: The unit is rated 0.69A input and 0.625A output. It is getting somewhat warm to the touch, but not hot. Is it safe to use with a PC with a 420W PS?
 As seen above on the bottom left, although it uses a grounded plug, there is a provision for an "environmental reference ground" according to a sticker on the unit. Would I benefit from using this ground? And if so, how?
  
 Would appreciate help with this.


----------



## mordy

Well folks, hit a dead end. After some 3-4 hours the transformer suddenly cut out. I assume that the overload circuit was activated.
  
 I am not giving up yet; I'm going to get rid of that hum!


----------



## Acapella11

trolldragon said:


> Gain Setting?


 

 Yes, indeed. Thanks for reminding. Set my gain 2 years ago to 10 and forgot about it.
  


mikelap said:


> Interesting, more neutral  you say, is that with the Senns and by the way nice aquisition .MK4 has different sound signature ,does that mean better sound quality


 
  
 Thanks, well at the moment I have like no time to listen to it. The MKIVSE may also need to burn in properly. Unfortunately, I don't have the MKIII any more around, so my comparisons are not very accurate. However, I did notice, the MKIVSE sounding more neutral, less "tubey" (less euphonic), a bit brighter, less coulored maybe. When I listened to the 6SN7GT, which sounded quite mellow but detailed before, they now sound like a better match with the HD800s, just more lively. On the other hand, the Tung Sol 5687WA sounded very nice on the MKIII, as in very vibrant, but on the MKIVSE, I was rather feeling that I would get a listening fatigue. The slightly darker Siemens 5687WB (supposedly relabelled Raytheon) were a better and good match now. This is all still prelimniary. The only other detail I think I can point is out is that the MKIVSE stage was wider and deeper.


----------



## Oskari

mordy said:


> Have two questions: The unit is rated 0.69A input and 0.625A output. It is getting somewhat warm to the touch, but not hot. Is it safe to use with a PC with a 420W PS?


 
  
 We don't know how much the computer actually draws but I don't think it's safe. 120 V * 0.625 A = 75 VA which is quite a bit less than 420.
  


mordy said:


> Well folks, hit a dead end. After some 3-4 hours the transformer suddenly cut out. I assume that the overload circuit was activated.


 
  
 I guess so. Did it reset?


----------



## i luvmusic 2

It could be from the adapters?
  
 My C3g's are Dead quiet all the way to the max of the volume pot but occasionally i knocked the adapter out of place and it will hum.


----------



## mordy

Hi Oskari,
  
 Thankfully, the isolation transformer just shut off from thermal overload, and it works fine. Decided to try the transformer with the LD MKIII plugged into it. The LD is rated at 30W so this would be a much better match.
  
 Another dead end - the sound was clearer, but there was a hollow and thin quality to the mid and low bass that wasn't satisfying.
  
 Another anomaly: when testing for hum with my laptop connected, it was quiet at low volume, then hum appeared between 11 to 15 (clockwise) and disappeared again at high volume. The same hum appeared at the same levels without the isolation transformer plugged in. In any case, this hum is much lower than from my PC and only noticeable when the music isn't playing.
  
 I realize that the transformers used in the amps and in the system have an effect on the clarity of the sound. Don't know how important this aspect is in the total presentation.


----------



## TrollDragon

A standard Cooler Master RS-460-PSAR-J3 460W power supply will haul down 8.5A @ 115Vac under full load. Since you are only using the 12V rails the AC current would have to be measured to get an accurate reading but I know it will be well above the 0.6A ration of that isolation transformer.


----------



## mordy

Hi TD,
  
 Here is a picture of the specs of my PS that I use to power the heaters on two 2.5A 6080 tubes for my LD MKIII:
  

  
 I am correct in that this is 115V/10A PS that supplies 15A at 12V? Using a 15A voltage regulator, how many amps are available at 6.3V?


----------



## Acapella11

I'd guess 7.875 A.


----------



## TrollDragon

mordy said:


> Hi TD,
> 
> Here is a picture of the specs of my PS that I use to power the heaters on two 2.5A 6080 tubes for my LD MKIII:
> 
> I am correct in that this is 115V/10A PS that supplies 15A at 12V? Using a 15A voltage regulator, how many amps are available at 6.3V?


 
 Yes that power supply under full load would draw 10A from your AC Mains.
  
 There should be 15A available for 6.3V, the regulator will only give you on the output what is available on the input. If there is 4A available on the input there there will only be 4A available on the output.


----------



## Artsi

I have finished my newest DIY amp. Sadly no headphone connect (yet?). I bought Russian 6F6S tubes because of this effect.

 With 6F6S's around 2x13w triode connected and pentode connected 2x18w. So these small powertubes are giving their max. Of course this amp is designed for KT88's, and with them i get much more power. And here is the amp with 5U4G, 4 6F6's, 2 6SN7 and 12AV7.

 I had so many different 12A*7 tubes from little dot times, so decided to use these as driver tube and they tolerate more voltage than 6DJ8. Transformers and choke are from old Hammond organ amplifiers. 4 inputs and again selector switch from old organ, since it was way better quality, than new small plastic knob. 6SN7's are connected as long-tailed-pair phase inverters. There is small switch for triode-pentode change behind powertubes. It seems to be mostly as for experimental and not for real high-end sound with pentode connection.
  
 Amp size is 50x37cm and weights 20kg.


----------



## siles1991

ah crap ahahaha i think 1 of my power tubes are dying, i swapped them left to right and i can confirm that 1 of them has lost a bit of volume and its dimmer then the other so I guess i'll be getting a power upgrade before my drive hahaa


----------



## mordy

What tube is it?


----------



## Acapella11

Just a brief MKIVSE / 5687 update: Either it is gear or brain burn in but I am not perceiving the MKIVSE as hard anymore, such that the Tung Sol 5687WA black plates are now a very good match. In fact from all power tubes that I have heard, they come closest to the Reflektor DN30P-DR (1983). I wouldn't yet say that they are superior because the resolution of the DRs is really outstanding but they are close and match in signature.
 But, I must say that I find the 5687 bass more 'visceral', it seems to extend deeper.


----------



## Acapella11

mordy said:


> Well folks, hit a dead end. After some 3-4 hours the transformer suddenly cut out. I assume that the overload circuit was activated.
> 
> I am not giving up yet; I'm going to get rid of that hum!


 
  
 Have you considered to use a form of uncoupling of your external DAC and laptop, e.g. galvanic uncoupling?


----------



## i luvmusic 2

artsi said:


> I have finished my newest DIY amp. Sadly no headphone connect (yet?). I bought Russian 6F6S tubes because of this effect.
> 
> With 6F6S's around 2x13w triode connected and pentode connected 2x18w. So these small powertubes are giving their max. Of course this amp is designed for KT88's, and with them i get much more power. And here is the amp with 5U4G, 4 6F6's, 2 6SN7 and 12AV7.
> 
> ...


 
 Very nice!How i wish i can read schematics so i can build my own amp.I'am a sucker for DIY Amps


----------



## siles1991

mordy said:


> What tube is it?


 
 The 6N6P-IR


----------



## mordy

Hi siles1991,
  
 Here is a quote that may be helpful:
  
 "You mention that one of the stock tubes completely burnt out after two years. How do you know it burnt out? The reason I am asking is that I had the same experience. However, for some reason I saved it.
 A year later on a hunch I took out my little pocket knife and and scraped clean the pins on the bad tube. Pushed it back in, and you wouldn't believe it! It lit up again and works fine. Looks like a little corrosion made it stop working.
  
 About the IR tubes: Although they are rated for 500 hours, and the regular 6N6P tubes for 3000 hours, I agree with the posts that state that this is for severe military working conditions (maybe in a MIG fighter plane).  IMHO they should last much longer in a little quiet preamp...."
  
 I used my own 6N6P-IR extensively for around 18 months. After that I switched to what I consider to be better tubes. Tried the 6N6P-IR as a driver with a breadboard and the Vector adapters. I was surprised to hear that one channel was much lower in volume on both tubes - did not notice this when used as power tubes.
  
  If the tube turns white inside instead of silver, this is a sure sign that you lost the vacuum and the tube is finished. If it looks normal, try scraping the pins gently in case they oxidized.


----------



## siles1991

mordy said:


> Hi siles1991,
> 
> Here is a quote that may be helpful:
> 
> ...


 
 ok i,ll try cleaning the pins and try again thanks for the info


----------



## mordy

Any luck?


----------



## MIKELAP

If anybody is looking for loctal sockets good ones TUBE DEPOT has them $4.95 each hopefully they still have them in stock                                                     https://www.tubedepot.com/products/8-pin-loctal-socket-4cx250b-4cx400a-etc


----------



## Acapella11

Hi, Just for Christmas I have put together a table as a reminder for everyone in the thread  and to help new arrivals. The table is now pretty much complete.
  
 Please, let me know if you find any additions or anything that requires correction.
  
*Little Dot I" / II/ III / IV Endgame Tube Table*
  

*Power Tube*   *Name**Adapter**Heater Current (A) / 6.3 V**Notes*5687/7044/7119(E182CC)5687 Powersocket Adapter 0.9easily usable substitutes, sound great6AS7G/6080Adapter + External Power Supply, see 1 and 2 and 32.5this is probably the icing of the power tube cake12AU7/12AT7/12AX7/7025/5751/ECC83/6057Powersocket Adapter0.35 6BL7/6BX7/6BQ7Adapter + External Power Supply, see 1 and 2 and 31.5 6DJ8not needed0.365 6GU7/6CG7/6FQ7not needed0.6not compatible with 12AX7 driver tubes6N23Pnot needed0.31 6SL7*6SN7 Powersocket Adapter0.3lower gain than 6SN7, not compatible with low impedance cans6SN7*6SN7 Powersocket Adapter0.6classic high end tube, not compatible with low impedance cans6N6P-IRnot needed0.9high quality, long lasting version of the 6N6P-I and considered best sounding 6N6P before the very expensive 6N6P-DR    Maximum recommended heater current for power tubes is 1.0 A. Tubes exceeding this are highlighted in red.      *Driver Tube*   *Name**Adapter**Heater Current (A) / 6.3 V**Notes*5687/7044/7119(E182CC)External driver socket ^, external power supply0.96.3 V / 12.6 V **6350/6463/ECC813External driver socket ^, external power supply0.96.3 V / 12.6 V**2C51 / 396A / 5670External driver socket ^ + driver socket adapter0.35 7AU7External driver socket ^0.63. 5 V / 7 V**12AU7External driver socket ^0.36.3 V / 12.6 V**12AU7/12AT7/12AX7/7025/5751/ECC83/6057*External driver socket ^0.3One triode can be used besides a non-powered one, 6.3 or 12.6 V**6BQ7AAdapter0.4 6DJ8External driver socket ^0.365probably noisiest double triode, both triodes must be powered6HM5none0.19probably best standard AK5-type option6N23Pnone0.31 6SL7*6SL7 driver adapter0.3 6SN7*External driver socket ^, external power supply0.6 C3G(S)* ^^C3G AK5 Adapter0.37C3G(S) tubes sound great but they are produced with a fragile glass base. Widen the socket holes before inserting the tube to avoid breaking.ECC81External driver socket ^0.3 ECC40External driver socket ^, external power supply0.6 E80CC/6085External driver socket ^, external power supply0.6 6.3 V / 12.6 V **     Maximum recommended heater current for driver tubes is 0.4 A. Tubes exceeding this are highlighted in red.
  
   *: Requires socket extenders for LD MKIII": For Little Dot I only driver tubes.  9 Pin power socket extender   7 Pin driver socket vector extender   **: Generally, when doubling the voltage, the apparent current is halved.  ^: The external driver socket adaper uses a breadboard and allows the use of a single double triode to drive both channels. ^^ Hypnos1 (post 5670): How to remove the C3Gs metal shielding, this requires care to not break the fragile tubes. 
 
    Power Tube Requirements (Gibosi post #7937)  1) Double triode   2) Separate cathodes (there are some double triodes such as the E90CC where the triodes "share" a cathode. These will not work.) 3) Heater current 1.0A or less   4) 6.3 Volts       List of compatible tubes and 6DJ8, 6SL7, 6SN7, 12AX7 wiring instructions  
  
 For old school driver tubes operable without adapter, see page 77.
  
 Driver Tube 7-Pin Vector Socket Adapter





  
 Power Tube 9-Pin Socket Adapter




  
_Revisions 1 & 2, 24/12/2014:_ Thanks for the input Gibosi and Mordy, thanks for sending the socket extender pictures Mordy, which are now included. Added a reference to Hypnos1 on how to remove the C3G(S) metal shielding.
 Added ECC40 and E80CC/6085 as suggested by Gibosi, thanks.
 Merry Christmas.
 Revision 3, 09/01/2015: Added links to the implementation of 6AS7G/6080 power tubes, thanks Gibosi for finding the posts and suggesting the implementation and Mordy making it work. Added link to page 77 and 6N6P-IR.
 Revision 4, 10/02/2015: Updated power tube links for 6080/6AS7G by Mordy's post 9059 on page 604 (3)


----------



## i luvmusic 2

acapella11 said:


> Hi, Just for Christmas I have put together a table as a reminder for everyone in the thread  and to help new arrivals. Please treat this as a alpha version of would be the final product but however I hope it provides useful data for everyone interested.
> 
> Please, let me know if you find anything that requires correction.
> 
> ...


 
 Thank You! for posting these it's very helpful.


----------



## Acapella11

i luvmusic 2 said:


> Thank You! for posting these it's very helpful.


 
  
 Thanks i luvmusic 2!


----------



## vic2vic

acapella11 said:


> Hi, Just for Christmas I have put together a table as a reminder for everyone in the thread  and to help new arrivals. Please treat this as a beta version of would be the final product but however I hope it provides useful data for everyone interested.
> 
> Please, let me know if you find anything that requires correction.


 
  
 WOW ! Amazing job. Page 585 is now the new "page 77" 
	

	
	
		
		

		
		
	


	



 I need to change my fixed bookmark.


----------



## Rossliew

MERRY CHRISTMAS y'all fellow tube rollers of the LD land!!


----------



## Acapella11

Merry Christmas everyone!


----------



## hypnos1

More best CHRISTMAS WISHES  for all members - old and new!
  
 And continued HAPPY ROLLING in a HAPPY NEW YEAR too...
	

	
	
		
		

		
		
	


	



  
 Cheers!!


----------



## MIKELAP




----------



## hypnos1

artsi said:


> I have finished my newest DIY amp. Sadly no headphone connect (yet?). I bought Russian 6F6S tubes because of this effect.
> 
> With 6F6S's around 2x13w triode connected and pentode connected 2x18w. So these small powertubes are giving their max. Of course this amp is designed for KT88's, and with them i get much more power. And here is the amp with 5U4G, 4 6F6's, 2 6SN7 and 12AV7.
> 
> ...


 
  
 Artsi....you are a true CRAFTSMAN - one of the highest order. I envy you your skills. Marvellous work!


----------



## i luvmusic 2

MERRY CHRISTMAS TO ALL!


----------



## Acapella11

Just found an interesting sniplet of information in the beginning of the 'Schiit happens' story:
"...you may have heard of Mike Moffat. He was the founder of Theta (the first one, the analog one), in the late 1970s. You can blame him, at least in part, for resurrecting tube audio. He was the first person to use 6DJ8s in audio."
Mike Moffat and Jason Stoddard founded Schiit.


----------



## Nic Rhodes

LOL, not to take anything away from Mike M whom I have the greatest respect but Fisher used the 6DJ8 in 1957 in the FM 90x tuner as a development tube before it even had a proper designtion! Fisher called it a 'Gold Cascode', it then got it's RETMA code as all wanted it. The tube was used in all sorts of audio stuff regularly ever since like the Marantz 9 power amp just as an example in 1960s, Audio research SP 6c? in 70s.....but it is great Mike is still using this stuff.


----------



## Shrew

Hi, just got the HD650s and I'm interested in beginning my journey into tube amps; Little Dot seems like a good place to start. What are your thoughts on the Little Dot MK2? Are there any cheaper options that sound just as good?
  
 I really want to experience the "warm" tube sound and experiment with tube rolling, so any advice is appreciated.


----------



## siles1991

mordy said:


> Any luck?


 
 i've tried scraping and using sandpaper as well but no go....sigh


----------



## i luvmusic 2

shrew said:


> Hi, just got the HD650s and I'm interested in beginning my journey into tube amps; Little Dot seems like a good place to start. What are your thoughts on the Little Dot MK2? Are there any cheaper options that sound just as good?
> 
> I really want to experience the "warm" tube sound and experiment with tube rolling, so any advice is appreciated.


 
 ...............


----------



## gibosi

shrew said:


> Hi, just got the HD650s and I'm interested in beginning my journey into tube amps; Little Dot seems like a good place to start. What are your thoughts on the Little Dot MK2? Are there any cheaper options that sound just as good?
> 
> I really want to experience the "warm" tube sound and experiment with tube rolling, so any advice is appreciated.


 
  
 Purchased directly from Little Dot (which is highly recommended as amps purchased from unauthorized vendors are not covered by the manufacturer's warranty) for $136 USD, I am not aware of any other amp costing less that can compare.
  
 On the other hand, based on the experience of a number of posters in this thread, the LD MKIII seems to be a better value, for around $50 more ($189 USD). But for sure, if you can't afford the III, the LD MKII should be fine.


----------



## sgbwill2

shrew said:


> Hi, just got the HD650s and I'm interested in beginning my journey into tube amps; Little Dot seems like a good place to start. What are your thoughts on the Little Dot MK2? Are there any cheaper options that sound just as good?
> 
> I really want to experience the "warm" tube sound and experiment with tube rolling, so any advice is appreciated.


 
 If you want warm I would go for La Figaro (LF) / DarkVoice (DV) range over the little dot range. The little dot's (LD) are awesome but are nowhere near as warm as DV and LF. Although I don't own the DV 336se which is in the same price range as the LD MK III, I own its big brother the la figaro 339 and its lovely and warm and is a perfect match with the 650's. There are plenty of threads and reviews out there on the DV 336se which describe it as being quite warm sounding so I would go check them out before making the decision on what entry level tube amp to get.


----------



## gibosi

Of course, the DV and LF are wonderful amps. However, in my opinion, warmth is more a function of the tubes, than the amp itself. With warm tubes, and RCAs are some of the warmest, a Little Dot can be quite warm. For example, RCA 5687WA as powers (pin adapters required) and a pair of RCA 6DT6s as drivers.


----------



## sgbwill2

gibosi said:


> Of course, the DV and LF are wonderful amps. However, in my opinion, warmth is more a function of the tubes, than the amp itself. With warm tubes, and RCAs are some of the warmest, a Little Dot can be quite warm. For example, RCA 5687WA as powers (pin adapters required) and a pair of RCA 6DT6s as drivers.


 
 True, I agree with this however with the DV 336se you can run the RCA 6AS7 which is very warm sounding without the hassle of adapters or external heaters which also may be cheaper in the long run due to the price of adapters etc. However if it is diverse tube rolling options that Shrew is looking for then the LD would be better in that respect.


----------



## TsukiNick

Where do I get Socket savers for my Little Dot MK III?  I just want something short that prevents me from screwing up my unit if I swap tubes.  I want to get some EF91 Tubes, so I'll be switching back and forth depending on headphones


----------



## gibosi

tsukinick said:


> Where do I get Socket savers for my Little Dot MK III?  I just want something short that prevents me from screwing up my unit if I swap tubes.  I want to get some EF91 Tubes, so I'll be switching back and forth depending on headphones


 
  
 Leeds Radio carries "Test socket 7 pin miniature" for $8.00 which might work for you.
  
 http://leedsradio.com/parts-sockets.html#savers
  
 That said, I have rolled hundreds of tubes through my LD with no apparent damage to the sockets, so I strongly doubt that this is something you have to worry about.
  
 Cheers


----------



## i luvmusic 2

shrew said:


> Hi, just got the HD650s and I'm interested in beginning my journey into tube amps; Little Dot seems like a good place to start. What are your thoughts on the Little Dot MK2? Are there any cheaper options that sound just as good?
> 
> I really want to experience the "warm" tube sound and experiment with tube rolling, so any advice is appreciated.


 
 I was going to say this before but i deleted it because i don't want anybody to bite my head off.The LD MK III will not do any justice for your HD 650 even using a C3g tubes.If you can DIY get the CRACK.


----------



## Acapella11

The HD650 is a very scaleable headphone. The Crack would hardly be endgame. However, at one point you will get a better total by purchasing a higher end headphone.


----------



## TsukiNick

acapella11 said:


> The HD650 is a very scaleable headphone. The Crack would hardly be endgame. However, at one point you will get a better total by purchasing a higher end headphone.



I refuse to CRACK and purchase a new amp. Those moneys are for Closed Back around ears haha.


----------



## Acapella11

sgbwill2 said:


> True, I agree with this however with the DV 336se you can run the RCA 6AS7 which is very warm sounding without the hassle of adapters or external heaters which also may be cheaper in the long run due to the price of adapters etc. However if it is diverse tube rolling options that Shrew is looking for then the LD would be better in that respect.


 
  
 Warmth is a personal preference or a signature matching criteria. If you'd asked me whether I favour a very warm amp over a rather neutral amp, I would always decide for the neutral amp. However, warmth does not reflect sound quality, as for example imaging or dynamics and this is important to consider also. If you have both amps at hand, I would be very curious about an A/B comparison with the LD using some nice drivers and - say 5687 power tubes.


----------



## sgbwill2

acapella11 said:


> Warmth is a personal preference or a signature matching criteria. If you'd asked me whether I favour a very warm amp over a rather neutral amp, I would always decide for the neutral amp. However, warmth does not reflect sound quality, as for example imaging or dynamics and this is important to consider also. If you have both amps at hand, I would be very curious about an A/B comparison with the LD using some nice drivers and - say 5687 power tubes.


 
 I only mentioned the DV range as Shrew was asking about warm sounding amps and the DV/LF range is notoriously warm/tubey sounding and the 336 is in the same price range as the LD MKIII. I have never owned the 336 but I do own the LF 339 and it is a warm sounding amp, especially in comparison to the LD MKIII. I personally like warm sounding amps and yes warmth does not effect sound quality. The LF is warmer yet its sound quality, imaging and dynamics far surpass the LD in every way even when using c3g's and 5687's, though this should be expected as they are in completely different price brackets.


----------



## Acapella11

sgbwill2 said:


> The LF is warmer yet its sound quality, imaging and dynamics far surpass the LD in every way even when using c3g's and 5687's, though this should be expected as they are in completely different price brackets.


 
  
 That's fair enough.
  
  
 Enjoying the Siemens (Raytheon) 5687WB + C3GS at the moment. Good bass and wet, very detailed sound.


----------



## gibosi

I think I would agree that the Crack and DarkVoice 336SE are very likely better than a Little Dot III, and the difference is largely due to the use of the 6AS7 as a power tube. However, I still maintain that of the three, the LD is the best value for the least amount of money.
  
 The LD III is $189 plus $45 shipping (to the US) for a total of $234, directly from the manufacturer. This includes one of the best warranty and support programs in the business.
  
 The Crack is $279 plus $16 shipping (to Ohio, USA) for a total of $295, directly from the manufacturer. However, many believe that the Speedball upgrade is essential, $115, which would bring the total to $410. And this price includes a decent parts warranty and support. However, since this is a kit, obviously they cannot warranty the assembly, which means, if it doesn't work, it's largely your problem.
  
 As best I can tell, the DarkVoice cannot be purchased directly from the manufacturer. In fact, I cannot find a manufacturer's web site for this amp, which leads me to wonder who is the actual manufacturer? And further, this leads me to wonder if there is a "manufacturer's warranty"? If not, the only recourse would be to send it back to the seller. A quick search reveals prices ranging from $263 to $299, all with free shipping (to the US).
  
 While the DV costs more than the LD, the price might be close enough to be comparable. However, the warranty issue is something to consider. Given the LD's superb warranty, the DV might be a bit of a gamble, but yes, I think the DV is a better amp, if one is willing to accept more risk.
  
 For someone who is comfortable with a soldering iron, the Crack might be the way to go. But frankly, I wouldn't purchase it without the Speedball option, and at $410, the price is close to the cost of the Elise, which is an even better amp, I believe.
  
 So if one wants to spend something around $200, the LD III is very hard to beat in my opinion.


----------



## sgbwill2

The Darkvoice/La Figaro 336 is no longer in production however (http://www.ebay.co.uk/itm/DarkVoice-336SE-Headphone-Tube-Amplifier-neat-technics-/260695457691?pt=US_Pro_Audio_Amplifiers&hash=item3cb2a8ff9b) who still sell it provide a 1 year manufacturer warranty as can be seen in the description which is longer than the LD's at 3 months. Both are arguably the best bang for buck tube amplifiers out there just depends on what preferences you have. For us in the UK the Crack isn't really an option unless wanting to pay a lot for shipping and import duties etc.


----------



## gibosi

sgbwill2 said:


> The Darkvoice/La Figaro 336 is no longer in production however (http://www.ebay.co.uk/itm/DarkVoice-336SE-Headphone-Tube-Amplifier-neat-technics-/260695457691?pt=US_Pro_Audio_Amplifiers&hash=item3cb2a8ff9b) who still sell it provide a 1 year manufacturer warranty as can be seen in the description which is longer than the LD's at 3 months.


 
  
 Within 3 months, LD will reimburse shipping costs, so there is absolutely no cost. After that, for as long as you own your LD, repair/labor/parts are always free - the only thing you are responsible for is shipping costs.
  
 As I said before, this is one of the best warranties in the business. 
  
 http://www.littledot.net/forum/viewtopic.php?f=9&t=442&sid=5c57ce139be89c76c139a0ab68ca22bb


----------



## sgbwill2

gibosi said:


> Within 3 months, LD will reimburse shipping costs, so there is absolutely no cost. After that, for as long as you own your LD, repair/labor/parts are always free - the only thing you are responsible for is shipping costs.
> 
> As I said before, this is one of the best warranties in the business.
> 
> http://www.littledot.net/forum/viewtopic.php?f=9&t=442&sid=5c57ce139be89c76c139a0ab68ca22bb


 
 My bad missed the for as long as you own it part


----------



## Acapella11

Happy New Year LDs!


----------



## bundy

Same too you my friend


----------



## michaelkeeney

Hey gang, hope everyone's having a great start to the new year.  Had a question that I haven't been able to find an answer to here online past a link to a product that is no longer manufactured, and that is a 6SN7 to 6N6P adapter.  Anyone know where to find one, or is more only choice to make my own?  Thanks.
  
 edit:  I think I figured it out on ebay, but not sure… is this them?
  
 http://www.ebay.com/itm/261667818185


----------



## Nic Rhodes

Does anyone know the current capability of the 20v winding on the transformer in the 1+? The 408s needs 50mA so it is at least that, wondering if it could do 125mA for a C3M....


----------



## gibosi

nic rhodes said:


> Does anyone know the current capability of the 20v winding on the transformer in the 1+? The 408s needs 50mA so it is at least that, wondering if it could do 125mA for a C3M....


 
  
 I routinely run the C3m in my LD 1+, and it sounds great! 
  
 Edit: I read too fast....  I have used the C3g, not the C3m....  My assumption is that the LD can power the C3m at 20V, but as I haven't tried it, I can't be sure....


----------



## gibosi

michaelkeeney said:


> Hey gang, hope everyone's having a great start to the new year.  Had a question that I haven't been able to find an answer to here online past a link to a product that is no longer manufactured, and that is a 6SN7 to 6N6P adapter.  Anyone know where to find one, or is more only choice to make my own?  Thanks.
> 
> edit:  I think I figured it out on ebay, but not sure… is this them?
> 
> http://www.ebay.com/itm/261667818185


 
  
 I assume you want to use 6SN7s as power tubes in your LD? 
  
 The 6N6P has the same pinout as a 6DJ8/6922/EC88 and 6CG7.
  
 So this will work:
  
 http://www.ebay.com/itm/1x-6SN7-to-ECC88-Vacuum-tube-socket-adapter-socket-converter-/291181600224?


----------



## MIKELAP

gibosi said:


> michaelkeeney said:
> 
> 
> > Hey gang, hope everyone's having a great start to the new year.  Had a question that I haven't been able to find an answer to here online past a link to a product that is no longer manufactured, and that is a 6SN7 to 6N6P adapter.  Anyone know where to find one, or is more only choice to make my own?  Thanks.
> ...


 
 I tried this link with Google and it doesnt work but if you use Internet Explorer it works


----------



## Acapella11

Re 6SN7 to 6N6P adapter: As per page 585 table, you can also use this link: http://www.ebay.com/itm/1pc-6SN7-6H8C-6N8P-CV1988-B65-VT231-TO-ECC88-6922-6DJ8-6N6-6N11-tube-adapter-/201083508552?rmvSB=true
  
 This link also shows you how the adapter should look like. Apparently, this seller only takes orders from the 8th of January on.


----------



## mordy

Have been using Musicbee for playing my music files. One feature that I like I haven't been able to find - maybe somebody can tell me how to find it:
  
 When playing a song, at times I want to go back to hear a certain passage, but I can only hear it again by playing the entire song on Musicbee. (This feature is easily found on iTunes, where a cursor moves along a bar indicating how long you played a tune, and how much is left. You just put your mouse cursor on it and move it forward or backward.)
  
 On my Musicbee screen I can only see time elapsed and remaining, but cannot find a place to move up or down in time.


----------



## Acapella11

mordy said:


> Have been using Musicbee for playing my music files. One feature that I like I haven't been able to find - maybe somebody can tell me how to find it:
> 
> When playing a song, at times I want to go back to hear a certain passage, but I can only hear it again by playing the entire song on Musicbee. (This feature is easily found on iTunes, where a cursor moves along a bar indicating how long you played a tune, and how much is left. You just put your mouse cursor on it and move it forward or backward.)
> 
> On my Musicbee screen I can only see time elapsed and remaining, but cannot find a place to move up or down in time.


 
  
 At the bottom of Musicbee is a grey bar. You can move with the mouse pointer up and down inside the song. The progress of the playback is indicated by a yellow bar.


----------



## MIKELAP

mordy said:


> Have been using Musicbee for playing my music files. One feature that I like I haven't been able to find - maybe somebody can tell me how to find it:
> 
> When playing a song, at times I want to go back to hear a certain passage, but I can only hear it again by playing the entire song on Musicbee. (This feature is easily found on iTunes, where a cursor moves along a bar indicating how long you played a tune, and how much is left. You just put your mouse cursor on it and move it forward or backward.)
> 
> On my Musicbee screen I can only see time elapsed and remaining, but cannot find a place to move up or down in time.


 
 Here's a screen shot of my setup you  point at progress bar same as itunes


----------



## mordy

Thanks A11 and Mikelap - found it now. I knew I could count on you guys!


----------



## Acapella11

Re MKIVSE, 5687WB/C3GS:
 I have settled for now with the combination of C3GS and 5687WB (Raytheon, Siemens label). The signature tends to a darker sound. This a) fits well with the HD800 and b) it seems to not generate any "false treble dynamics". What I mean with that is that sometimes, for example with some silver or cheaper copper cables, the treble gets slightly overemphasized/distorted, which seems to add dynamics but in my perception just "outshines"  valuable details. The 5687WB just takes that away and acts more like a single copper crystal cable. The sound stays dynamic but gets smooth, the treble refined and very detailed, I was very tempted to ramp up the volume straight to max 
	

	
	
		
		

		
			





. There is a small but nice bass bias, the mids are neutral to slightly warm and very natural, the stage is extensive in any direction and the background as black as it gets with this amp. So, if your headphone is on the "brighter side", this combination is highly recommended. Will post a pic later.
  
 PS: Works also well with the HE-500.


----------



## Rossliew

Can any one advise the equivalent for the 6N9P tube used in the Mk 9? thanks in advance.


----------



## sgbwill2

rossliew said:


> Can any one advise the equivalent for the 6N9P tube used in the Mk 9? thanks in advance.


 
 I don't own the MK 9 but equivalents of the 6N9P are 6SL7 tubes and their equivalents. Hope this helps


----------



## Rossliew

sgbwill2 said:


> I don't own the MK 9 but equivalents of the 6N9P are 6SL7/5693 tubes. EF 86 and its equivalents can also be used with adapters. Hope this helps


 

 Thank you very much! Helps a lot since i already have some 6SL7 tubes in hand for the Mk 3 rolling fun : ) 
  
 Just curious if the Mk 9 would be as good as a Mk 3 running 6AS7 power tubes with external heater supplies..


----------



## Rossliew

Just to add, am currently listening to the Mk 3 running Raytheon 6SN7s as power tubes mated with Western Electric WE403A as drivers - WOW! Holographic imaging and it lifts off the slight veil of the HD600. 
  
 (As an aside, my rig is using the Gungnir as DAC with source from Audirvana Plus on the Mac Air)


----------



## sgbwill2

rossliew said:


> Thank you very much! Helps a lot since i already have some 6SL7 tubes in hand for the Mk 3 rolling fun : )
> 
> Just curious if the Mk 9 would be as good as a Mk 3 running 6AS7 power tubes with external heater supplies..


 
 The MK 9 runs 2 6080 tubes which are identical to 6AS7's so no external heaters are needed for them. Other options for 6080's are 5998,2399,421A and 7236 tubes and the russian 6h13c/s. As for the sound I imagine the MK9 would sound better as it is actually designed to run these tubes whereas the MKIII is not.


----------



## Nic Rhodes

rossliew said:


> Can any one advise the equivalent for the 6N9P tube used in the Mk 9? thanks in advance.


 

  Ross, the 6N9P is basically a 6SL7GT so the following are good. 6SL7GT, 5691, CV1985, 6113, 6188, ECC35, CV569, VT 229. There are millions of these in circulation, others will work in adapters like the earlier top cap 6G8G (like the 6F8G on the 6SN7GT) but with such a wealth of possibles you may not want to go that route. 6SL7GT are quite cheap also because of the quantity they were made in..The 6SU7GT, 6188 is another great alternative, ruggidised version basically.


----------



## Rossliew

nic rhodes said:


> Ross, the 6N9P is basically a 6SL7GT so the following are good. 6SL7GT, 5691, CV1985, 6113, 6188, ECC35, CV569, VT 229. There are millions of these in circulation, others will work in adapters like the earlier top cap 6G8G (like the 6F8G on the 6SN7GT) but with such a wealth of possibles you may not want to go that route. 6SL7GT are quite cheap also because of the quantity they were made in..The 6SU7GT, 6188 is another great alternative, ruggidised version basically.


 

 Thanks for the list of compatible tubes, Nic. I have a few generic Russian 6SL7s so that should provide a good headstart. Am thinking of getting the Little Dot Mk 9 as starters and see if i enjoy the sound as compared to the Mk 3. Of course, the WA22 is very tempting but for the price, I would rather spend a larger portion of the money on tubes and music : ) Am already scouring eBay for some tubes to accumulate


----------



## mordy

Hi Rossliew,
  
 Perhaps you should consider the Feliks Elise as well since you are thinking of the LD MK9. Take a look at the Feliks thread:
  
 http://www.head-fi.org/t/732875/feliks-audio-6sn7-6as7g-6080-prototype


----------



## Acapella11

mordy said:


> Hi Rossliew,
> 
> Perhaps you should consider the Feliks Elise as well since you are thinking of the LD MK9. Take a look at the Feliks thread:
> 
> http://www.head-fi.org/t/732875/feliks-audio-6sn7-6as7g-6080-prototype


 
  
 He was already there


----------



## mordy

I realized it after I posted. But the question still remains: Since both amps are similar in price, why would a person interested in the MK9 not consider the Elise? I guess that we have to wait to see what Nic Rhodes says after evaluating both amps.......


----------



## MIKELAP

mordy said:


> I realized it after I posted. But the question still remains: Since both amps are similar in price, why would a person interested in the MK9 not consider the Elise? I guess that we have to wait to see what Nic Rhodes says after evaluating both amps.......


 
 It's like buying a new model car you dont buy it the first year its introduced you wait till the bugs are ironed out ,a bit like the Chevrolet Cruze well not really ,because there up to  9 or 10 recalls lol


----------



## gibosi

In my opinion the Elise and the MK9 are not directly comparable. The Elise is designed to use the 6SN7 (with a gain of 20) as the driver, whereas the MK9 is designed to use the 6SL7 (with a gain of 70). Evidently, it is possible to use the 6SN7 in the MK9, but given that the circuit was designed for a tube with a much higher gain, I doubt that it would sound nearly as good as it would in an amp explicitly designed for the 6SN7. 
  
 Therefore, if one decides to purchase the MK9, it would be best to stay with 6SL7s and other high gain tubes, such as the 12AT7, 5751 and ECC808.  And if one purchases the Elise, it would be best to stay with 6SN7s and other medium gain tubes, such as the 12AU7, ECC40 and 5687. From this, one factor to consider is how these two amps will work with an existing tube collection.
  
 For example, I have accumulated several hundred medium gain tubes and maybe a half-a-dozen high gain tubes. On this basis alone, I eliminated the MK9 from consideration. The Elise, based on the 6SN7, would allow me to roll all my favorite tubes, and thus is a much better fit for my collection.. And this same line of reasoning was a major factor in my decision to purchase a Glenn OTL.


----------



## hypnos1

mikelap said:


> It's like buying a new model car you dont buy it the first year its introduced you wait till the bugs are ironed out ,a bit like the Chevrolet Cruze well not really ,because there up to  9 or 10 recalls lol


 
  
 Hi M.
  
 Well mon ami, I've a good few hours (to say the least) on my Elise...and not the slightest hint of a bug, lol! On the contrary, it just keeps getting better and better...
  
 I understand your comments re new models (of cars at least!), but this is slightly different territory methinks 
	

	
	
		
		

		
			





. Especially as we aren't talking Chinese here! These Polish guys obviously take MUCH greater care with quality of components and circuit design, which makes for much better reliability of course.
  
 You know how much in praise I have been of my MKIV SE for a good while now, but she just does not compare to the Elise - even though modded to the nth degree!...And as for the MK9 using the same case - it may well have been very good for the modestly priced MKIV, but I would not be so happy for a 'higher' grade unit....Plus, as an example, just look at the difference in the all-important transformer! (And as for David Zhe Zhe saying ALL transformers make non-electronic noise...well all I can say is he should source his from Poland, lol! 
	

	
	
		
		

		
		
	


	




).
  
 As mordy says, it's gonna be REALLY interesting to see what Nic makes of them, if he does get both...can't wait...(come on Nic!! 
	

	
	
		
		

		
		
	


	




).


----------



## Rossliew

Thanks for the advice guys. I did contemplate the Elise but thought that the waiting time for the Mk9 would be shorter. But i would love to try both though. Lets see what Nic says when he has had the time to listen to both. I may spring for the Mk9 first in the meantime.


----------



## Rossliew

@gibosi , how long is the build time for your Glenn OTL? That would be another option for me if it does not take half a year or more to build..


----------



## bbmiller

gibosi said:


> For example, I have accumulated several hundred medium gain tubes and maybe a half-a-dozen high gain tubes. On this basis alone, I eliminated the MK9 from consideration. The Elise, based on the 6SN7, would allow me to roll all my favorite tubes, and thus is a much better fit for my collection.. And this same line of reasoning was a major factor in my decision to purchase a Glenn OTL.


 



  
 Hello
 what gibosi has stated above has given me food for thought. Quite a while ago I posted that I leave my little dot MK IV amplifier on 24 seven because I noticed such a large improvement in the sound running this amp 24 seven. At that time I was warned that perhaps doing this can result in me burning me and my house down. Consequently I did the above Modification shown in pictures above to install a computer fan that will blow directly into my little dot MK IV amplifier.
  
 Well I still think the difference between normal operation and 24 seven operation is phenomenal, but now think it's more phenomenal that I have ever thought it was before and all I could say is with the tubes I am now rolling its wow wow wow wow in terms of sound. I am presently using Russian NOVOSIBIRSK  plant late 70s vintage 6N8S as power tubes and the 6HM5 EC900 Yugoslavian triode's (often recommended on this thread) as driver tubes.
  
 Once I leve my amplifier on for 24 hours the sound gets just phenomenal. Consequently I've stocked up on these tubes owning 24 of the power tubes and 10 of the driver tubes. I think I will always, as long as I can still hear, want am amplifier which can use these double triode's 6SN7 family tubes as power tubes and the 7 pin Yugoslavian 6HM5 EC900 as driver tubes.
  
 So the reason I bring this up is I found doing this mod so difficult I think I would want to buy another amplifier other than the little dot MK IV amplifier before I would ever want to go through doing that mod again. So do any of you know of other amplifiers with just readily available adapters or fully ready to go tube sockets could use these tubes I love without modifying the amplifier. And be good to run in 24 seven operation out-of-the-box? I am thinking perhaps the amplifier mentioned earlier in this thread called La Figaro 339 could do it as least as far as the power tubes were concern, but I do not know if there is a driver tube adapter available to use that amplifier with seven pin Yugoslavian triode's. 
  
 So is there any amplifier which will let you use 6N8S power tubes and 6HM5 EC900 driver tubes immediately without modifying it for 24 seven operation?


----------



## bbmiller

bbmiller said:


> Duplicated an above post somehow and do not know how to delete a post.


----------



## sgbwill2

bbmiller said:


> So the reason I bring this up is I found doing this mod so difficult I think I would want to buy another amplifier other than the little dot MK IV amplifier before I would ever want to go through doing that mod again. So do any of you know of other amplifiers with just readily available adapters or fully ready to go tube sockets could use these tubes I love without modifying the amplifier. And be good to run in 24 seven operation out-of-the-box? I am thinking perhaps the amplifier mentioned earlier in this thread called La Figaro 339 could do it as least as far as the power tubes were concern, but I do not know if there is a driver tube adapter available to use that amplifier with seven pin Yugoslavian triode's.
> 
> So is there any amplifier which will let you use 6N8S power tubes and 6HM5 EC900 driver tubes immediately without modifying it for 24 seven operation?


 
 The LF 339 has 2 design options. Both use 6AS7/6080's as power tubes, so 6N8S/6SN7 wouldnt be very effective here as their draw up is so much lower (0.6A compared to 2.5A). As for driver tubes you have the choice of either 6J4P, 6SJ7, 5693, 6Ж4С (+ all equivalents e.g. ef80/ef86) or 6C5, 6J5, 6J5G, 6J5GT, L63 (+ all equivalents) so 6HM5/EC900's cant be used here either. And I would never run the LF 339 24/7 as the metal case is designed to be a heatsink meaning it runs really hot. To be honest I wouldn't run any tube amp 24/7 even with fans as components are likely to burn out sooner as well as this the tubes life will be greatly reduced in the long run.


----------



## bbmiller

bbmiller said:


> Duplicated an above post somehow and do not know how to delete a post.


----------



## bbmiller

sgbwill2 said:


> To be honest I wouldn't run any tube amp 24/7 even with fans as components are likely to burn out sooner as well as this the tubes life will be greatly reduced in the long run.


 
 obviously if you run tubes 24/7 they are likely to burn out three times faster than were you to only run them for eight hours a day. But if the tubes are cheap enough like $15 for a set of four tubes which is about what it will cost me with the tubes I am talking about bought in bulk I think it is well worth it since the improvement in sound is so phenomenal. As for other components perhaps if I get another amplifier it should be one with highly accessible components much more so than a little dot MK four design.

 Back in the day phone companies and other commercial operations must've used commercial electronics 24/7.


----------



## MIKELAP

hypnos1 said:


> mikelap said:
> 
> 
> > It's like buying a new model car you dont buy it the first year its introduced you wait till the bugs are ironed out ,a bit like the Chevrolet Cruze well not really ,because there up to  9 or 10 recalls lol
> ...


 
 Maybe i didnt say this right ,I am not saying its not a good amp i like this amp very much . it just  a question of getting some reputation ,credibility first because i never heard of Feliks audio before the Elise,so a more indept look of the amp is warranted i would say before committing to buying  the amp   and that starts with a look of  internal parts quality ects.fixing little thingd like the cover of the amp so it will accept 6080 tubes without extenders  that will come in time im shure .Bottom line is  if they want to sell there amp they wont have a choice but to show there stuff. .A good example  is our Littledot  amps at first im shure potential buyers were not to enthusiastic about Littledot  amps but eventually they gain a good reputation and if you want to sell your amp its almost a shure thing .Thats the way i see it  .                                                                                                                                                                                                                                                                                                                                               .


----------



## mordy

Hi Rossliew,
  
 When I asked Lukasz about the availability of the new Elise amp he said that it should be available in January 2015.
  
 Hi Mikelap,
  
 The Feliks company is in business for 10 years, so it's not like a brand new company. I do agree with you about waiting for bugs/improvements to be worked out. As far as I know, the Little Dot MKIII that I have is v.2 which allows for more choices in tube rolling than the previous version.
  
 On the other hand, it sounds very tempting to get the Elise amp....


----------



## MIKELAP

mordy said:


> Hi Rossliew,
> 
> When I asked Lukasz about the availability of the new Elise amp he said that it should be available in January 2015.
> 
> ...


 
 Yes it is very very tempting but as the saying goes ¨Good thing come to those who wait ¨


----------



## TrollDragon

mikelap said:


> Yes it is very very tempting but as the saying goes ¨Good thing come to those who wait ¨


----------



## TrollDragon

so55 said:


> Hi all,
> 
> Where's the best place to buy little dot from the UK?
> 
> thanks


 
 The best place is to get them from Little Dot directly or David ZheZhe's eBay site. Everyone else is an unauthorized reseller.
  
 Little Dot Driect
 http://www.littledot.net/forum/viewforum.php?f=9&sid=7744aa7d0637f11f23b9ee67f0b9b864
  
 eBay
 http://www.ebay.com/sch/davidzhezhe/m.html?_nkw=&_armrs=1&_from=&_ipg=&_trksid=p3686


----------



## MIKELAP

trolldragon said:


> mikelap said:
> 
> 
> > Yes it is very very tempting but as the saying goes ¨Good thing come to those who wait ¨


 
 Time will tell .


----------



## TrollDragon

bbmiller said:


>


 
 OMG What did you do to that poor little amp...
	

	
	
		
		

		
			




  
 Sacrilege


----------



## Nic Rhodes

My MK9  will be here wednesday, I won't be back until late thursday but have friday off


----------



## bbmiller

trolldragon said:


> bbmiller said:
> 
> 
> >
> ...


 
 OK
 I don't know if anybody here will ever believe me but I did see that running my amp 24/7, I don't mean with music I just mean leaving it on, created a tremendous improvement in the sound even with the stock tubes. So consequently I wanted to make it 24/7 capable. I started this thread which can be found here to ask if adding  cooling holes to a chassis would thoroughly break the shielding and got advice that it would not. They explained shielding was frequency dependent and I could create holes that would still shield at audio frequencies.
  
 My amp looks a lot better than in that particular picture I have covered the holes with window screening. And put a computer fans on top of where most of the holes are in a rubber mate food container so that I might constantly forced air through the amplifier case to make sure that all of the critical parts of this amplifier stay cool enough for 24/7 operation.
  
 As I have explained in the above posting I found that using $15 worth of 6N8S power tubes and 6HM5 EC900 driving tubes I get as spectacular sounding amplifier once I leave it on for 24 hours.
  
 I am now looking to see if there is some other amp that will let you use the tubes I just mentioned without such a radical modification. I mean is there amp that will let you use these tubes, which you are now my tubes of choice, with out modification in a on 24/7   mode because I do not know if anybody will ever believe me but to me leaving these tubes on 24 seven makes a tremendous improvement in the sound. I can't believe I get such good sound through my little dot MK IV amplifier and my Sennheiser 600 HD headphones. In my opinion I have a tremendously good sounding headphone amplifier set up as long as I do not turn it off.


----------



## sgbwill2

bbmiller said:


> OK
> I don't know if anybody here will ever believe me but I did see that running my amp 24/7, I don't mean with music I just mean leaving it on, created a tremendous improvement in the sound even with the stock tubes. So consequently I wanted to make it 24/7 capable. I started this thread which can be found here to ask if adding  cooling holes to a chassis would thoroughly break the shielding and got advice that it would not. They explained shielding was frequency dependent and I could create holes that would still shield at audio frequencies.
> 
> My amp looks a lot better than in that particular picture I have covered the holes with window screening. And put a computer fans on top of where most of the holes are in a rubber mate food container so that I might constantly forced air through the amplifier case to make sure that all of the critical parts of this amplifier stay cool enough for 24/7 operation.
> ...


 
 I have never tried running an amp 24/7 but I don't see how it would improve sound quality as tubes reach their max temperature only after a relatively short period of time (also depends what tubes they are) but as for the 6AS7's and 6SJ7's I use I would say they have reached max temperature in under 30 mins and leaving them on longer doesn't change the sound at all.


----------



## hypnos1

mikelap said:


> Maybe i didnt say this right ,I am not saying its not a good amp i like this amp very much . it just  a question of getting some reputation ,credibility first because i never heard of Feliks audio before the Elise,so a more indept look of the amp is warranted i would say before committing to buying  the amp   and that starts with a look of  internal parts quality ects.fixing little thingd like the cover of the amp so it will accept 6080 tubes without extenders  that will come in time im shure .Bottom line is  if they want to sell there amp they wont have a choice but to show there stuff. .A good example  is our Littledot  amps at first im shure potential buyers were not to enthusiastic about Littledot  amps but eventually they gain a good reputation and if you want to sell your amp its almost a shure thing .Thats the way i see it  .                                                                                                                                                                                                                                                                                                                                               .


 
  
 Hi M.,
  
 As mordy says, these guys have been around a fair while and have built some very attractive (and reliable by all accounts) equipment.
  
 Of course new models can sometimes have 'bugs' - but thank goodness there are pioneers in the world...'twould be a VERY sorry place otherwise, lol! 
	

	
	
		
		

		
		
	


	




. (There are those who lead, and those who follow...one chooses one's own path... -  there was no-one more cautious than myself in days gone by, but I have recently discovered the sheer joy of taking more risks...regardless of the occasional disappointment. But I respect your own standpoint, mon ami ...CHEERS!  
	

	
	
		
		

		
		
	


	




).
  
 Edit.   ps.  Enlarging the hole to accommodate the 6080 would not be very aesthetically pleasing, I think...given the socket has quite a deep recess, an extender is probably the better option IMHO...


----------



## gibosi

bbmiller said:


> I am now looking to see if there is some other amp that will let you use the tubes I just mentioned without such a radical modification. I mean is there amp that will let you use these tubes, which you are now my tubes of choice, with out modification in a on 24/7   mode because I do not know if anybody will ever believe me but to me leaving these tubes on 24 seven makes a tremendous improvement in the sound. I can't believe I get such good sound through my little dot MK IV amplifier and my Sennheiser 600 HD headphones. In my opinion I have a tremendously good sounding headphone amplifier set up as long as I do not turn it off.


 
  
 I sincerely doubt that there is a commercially available amp designed to operate 24/7. Unlike military and industrial applications, there is simply no real consumer demand for 24/7 in a head-phone amp, and given the extra costs to design and build such a product, it would likely fail in the marketplace....


----------



## bbmiller

gibosi said:


> bbmiller said:
> 
> 
> > I am now looking to see if there is some other amp that will let you use the tubes I just mentioned without such a radical modification. I mean is there amp that will let you use these tubes, which you are now my tubes of choice, with out modification in a on 24/7   mode because I do not know if anybody will ever believe me but to me leaving these tubes on 24 seven makes a tremendous improvement in the sound. I can't believe I get such good sound through my little dot MK IV amplifier and my Sennheiser 600 HD headphones. In my opinion I have a tremendously good sounding headphone amplifier set up as long as I do not turn it off.
> ...


 
 Well then will you know offhand if the pen out for the Yugoslavian  6HM5 EC900 driving tubes have a few or many commercially made adapters to  more commercially available amplifier sockets than the 7 pin triode socket they use or is 7 pin triode sockets comment in commercially available headphone amplifiers?


----------



## Nic Rhodes

My Vali has been on since I bought it  on release


----------



## natra084

hi guys I know that this thread it's not about the bravo ocean but I can't find any other threat about the bravo ocean the is active like this thread,I need some tube recommendations for this amp.


----------



## Acapella11

natra084 said:


> hi guys I know that this thread it's not about the bravo ocean but I can't find any other threat about the bravo ocean the is active like this thread,I need some tube recommendations for this amp.


 
  
 The Bravo Ocean uses 12AU7 tubes which are lower gain versions of the 12AT7, I advise you to look into a 12AT7 thread or best of all start your own Bravo Ocean thread. You won't find much 12AU7 information here, besides it is a totally different amp.


----------



## gibosi

natra084 said:


> hi guys I know that this thread it's not about the bravo ocean but I can't find any other threat about the bravo ocean the is active like this thread,I need some tube recommendations for this amp.


 
  
 And I would add that the 12AU7 is used as a driver for the Crack. So you might find some info on the Crack thread regarding this tube.
  
 Good luck!


----------



## gibosi

bbmiller said:


> Well then will you know offhand if the pen out for the Yugoslavian  6HM5 EC900 driving tubes have a few or many commercially made adapters to  more commercially available amplifier sockets than the 7 pin triode socket they use or is 7 pin triode sockets comment in commercially available headphone amplifiers?


 
  
 I am not aware of any amp that uses the 6HM5. We stumbled across this tube when we were searching for 7-pin tubes that would work in the LD, and I suspect that the vast majority of the people who buy this tube are LD owners. So no, to my knowledge, there are no adapters to allow this tube to be used in any other amp. And very frankly, in my opinion, there is no compelling reason to use the 6HM5, as even cheap double triodes are better.
  
 Edit: That said, it is very likely that the 6HM5 will work in any amp that is designed to use the 6AK5.


----------



## gibosi

nic rhodes said:


> My Vali has been on since I bought it  on release


 
  
 Yes indeed! I had forgotten that the Vali uses a sub-miniature triode-strapped 6088. A great little amp! But no tube rolling!


----------



## TrollDragon

natra084 said:


> hi guys I know that this thread it's not about the bravo ocean but I can't find any other threat about the bravo ocean the is active like this thread,I need some tube recommendations for this amp.


 

 Also the Bravo Ocean runs on a 24V adapter so the tube in it only has enough power to make it conduct.
 It is more along the lines of a SS amp with a tube for looks IMHO.


----------



## genclaymore

gibosi said:


> Yes indeed! I had forgotten that the Vali uses a sub-miniature triode-strapped 6088. A great little amp! But no tube rolling!


 

 I would have owned it instead of the little dot MK2 2.0 if it had rolling,Maybe some one could some how mode it in a way to accept different vacuum tubes with a special pin slot or wired in a way to work,maybe with addition mods to the design to make it work with 8 pins.


----------



## gibosi

genclaymore said:


> I would have owned it instead of the little dot MK2 2.0 if it had rolling,Maybe some one could some how mode it in a way to accept different vacuum tubes with a special pin slot or wired in a way to work,maybe with addition mods to the design to make it work with 8 pins.


 
  
 http://schiit.com/products/vali
  
 The 6088's heater draws only 1.2V DC and the plate is run at 60V. Unfortunately, fitting a 6.3V tube which is typically designed to operate at a significantly higher plate voltage into this circuit would be far from satisfactory.


----------



## Acapella11

Just plugged a pair of Raytheon JAN 6SN7WGT as driver tubes into the MKIVSE for the first time and firstly of course they are still not working any better with my low impedance HE500 but on the plus side they match better in signature with the MKIVSE than the MKIII. This is because the two pairs of 6SN7 I have tried tend to sound a bit warm/refined and the MKIVSE is more on the neutral side than the MKIII, which is a bit warmer.
 6SN7s sound very good as power tubes with my 300 ohm HD800, they should also be good with 250 ohm Beyers. The sound is livelier than on the MKIII, very detailed, would say more than the 5687, and the perception of the stage / ambience is excellent. So, higher Z + MKIVSE + 6SN7 power tube is an equation that works nicely. Driver tubes were C3GS.


----------



## MIKELAP

acapella11 said:


> Just plugged a pair of Raytheon JAN 6SN7WGT as driver tubes into the MKIVSE for the first time and firstly of course they are still not working any better with my low impedance HE500 but on the plus side they match better in signature with the MKIVSE than the MKIII. This is because the two pairs of 6SN7 I have tried tend to sound a bit warm/refined and the MKIVSE is more on the neutral side than the MKIII, which is a bit warmer.
> 6SN7s sound very good as power tubes with my 300 ohm HD800, they should also be good with a 250 ohm Beyers. The sound is livelier than on the MKIII, very detailed, would say more than the 5687, and the perception of the stage / ambience is excellent. So, higher Z + MKIVSE + 6SN7 power tube is an equation that works nicely. Driver tubes were C3GS.


 
 MK4SE in da house nice, congrats .Would you say sound is more solid state like compared to MK3 and would the sound be fuller than with MK3 .


----------



## Acapella11

mikelap said:


> MK4SE in da house nice, congrats .Would you say sound is more solid state like compared to MK3 and would the sound be fuller than with MK3 .


 
  
 Thanks. Again, this is from memory, and I would say, yes, more solid state like signature but the MKIII sounding fuller, in parts simply because the stage appears larger with the MKIVSE. I found that there is a MKIVSE burn in effect though, which mellowed the quite hard initial sound more to a neutral tube sound.


----------



## ToTje

Wow, yesterday my Little Dot had a continuous hum through both channels (left and right).
 Moving the tubes a bit did change the hum a bit, but it was quite loud.
 I swapped the left and the right tube, but the hum didn't change.
 Pulled out all the cables and plugged them back in; no change.
 I replaced the Voskhods with the French RTC 5654RT tubes that the amp originally came with, and the hum was significantly lower in volume.
 Then I took new Voskhods out of their packaging and placed them in the amp; exactly the same loud hum as with the other set.
  
 Then I realised: earlier that day I had placed the base of my home telephone next to the amp, and the tubes were picking up interference of it! 
	

	
	
		
		

		
			





 
	

	
	
		
		

		
		
	


	




 
	

	
	
		
		

		
		
	


	



  
 Funny to notice how much more sensitive to interference the Voskhods are than those RTC tubes. However, the sound of those Russian tubes is far superior over that of the French ones, so I keep using them for now. I still am looking around for other tubes a bit, based on what I read here.


----------



## superdux

Thx to the guys that bought the C3G's from me i was able to afford a few more tubes and i already mentioned the chinese tube a few posts back. Well now i have to say i have a very, lush and rich and mellow (and a bit dark) combination of tubes in my amp. I unplugged my C3G as the combination with the chinese 6SN7 wasn't that nice. Then i plugged back in the 6N23P Voskhod rocket factory tubes from 78 and i was fascinated with the sound that came out of my HD650s. The chinese tubes are Nankings 6SN7 from this seller:
  
 http://www.ebay.de/usr/orpheus_2005?_trksid=p2047675.l2559
  
 and i found a statement about these tubes after buying them, not knowing they were that precious:
  
 http://forum.audiogon.com/cgi-bin/frr.pl?rprea&1188586856&openfrom&28&4
  


> The best 6SN7's I have found are a pair of Nanjing 6N8P no longer in production. This is after Sylvanias, EH's, VT231's, and even the vaunted Russky 1578's with the holes. I did my research, and then tried the Chinese tubes on a whim, due to the fact that they have metal bases and were for sale cheap. Holy Valve, Batman! they were like the Russian "Holy Grail" 6H8C's but with a cleaner lower midrange, making them very clear, dynamic, spacious, musical, and tonally accurate. I despair to think of these tubes ever wearing out - I will never find another pair.


 
  
 This combi is nothing for you if you rather like a bright bassy presentation.But if you'd like to experience the music like sweet honey dripping in your ears then try it out. The details are also very discernable. I had Heaven or Las Vegas from the Cocteau Twins in my CD player listening to this combi. First i thought rather not say anything incase the chinese tubes get sold out but i thought about it: them having nearly a 10000 hour lifespan and me listening up to 2 hrs a day it would take more than 10 yrs for them to give up. So i won't buy a second pair and leave it to you guys to grab some.


----------



## natra084

Hi is there any dac that can be used tube amplifier without making any hissing noise when you turn up the volume at max without music playing.


----------



## Acapella11

Plugged today the Sylvania 6SN7WGT brown base tubes into the MKIVSE (with C3GS) and I am beginning to get sold to these as power tubes with my HD800. The feeling of the three dimensions of the stage (spatial perception) is really good, accurate instrument placement, very good imaging and great level of detail make a great experience 
	

	
	
		
		

		
		
	


	




.
  


> Originally Posted by *superdux* /img/forum/go_quote.gif
> 
> This combi is nothing for you if you rather like a bright bassy presentation.But if you'd like to experience the music *like sweet honey dripping* *in your ears *then try it out.


 
  
 Must be sound impression that sticks! 
	

	
	
		
		

		
		
	


	




 
  
 Was the combination of 6SN7 with HD650 in your MKIII too dark/not lively?


----------



## superdux

hi acapella,
  
 i think this is the synthesis of 2 very good tubes and the HD650 also being dark in nature and maybe the pitch black background of the 6N23P.


----------



## Peter_S

gibosi said:


> I am not aware of any amp that uses the 6HM5. We stumbled across this tube when we were searching for 7-pin tubes that would work in the LD, and I suspect that the vast majority of the people who buy this tube are LD owners. So no, to my knowledge, there are no adapters to allow this tube to be used in any other amp. And very frankly, in my opinion, there is no compelling reason to use the 6HM5, as even cheap double triodes are better.
> 
> Edit: That said, it is very likely that the 6HM5 will work in any amp that is designed to use the 6AK5.


 

 I just got a LD mkii v2 amplifier used with a number of tubes.  I had to re-mount the transformer, and I hope that the amp is working.  Will test it tomorrow.  One of the tubes is the EI 6HM5.  I just want to confirm that it is in fact suitable.  Can someone confirm?  Thanks, Peter


----------



## gibosi

peter_s said:


> I just got a LD mkii v2 amplifier used with a number of tubes.  I had to re-mount the transformer, and I hope that the amp is working.  Will test it tomorrow.  One of the tubes is the EI 6HM5.  I just want to confirm that it is in fact suitable.  Can someone confirm?  Thanks, Peter


 
  
 I do not know if version 2 of this amp is the current model or an older model..... If your amp can run EF 95 tubes, then yes, a pair of 6HM5 are perfectly suitable when used as drivers in current versions of LD I, II, III and IV.
  
 Good luck!


----------



## Acapella11

Re MKIVSE and 6SN7 powertubes: I have kept on listening to the two pairs of 6SN7 tubes and just wanted to share a few impressions.
Both are 6SN7WGT brown base tubes and both fit very well with the MKIVSE (for MKIII, I prefer the more vibrtantly sounding 5687) and HD800. Both sound more refined, darker and detailed than the 5687.
The Sylvanias present more bass and treble than the Raytheon, sound is more V-shaped and exciting. Treble is a bit harder, bass more "visceral", mids are a bit sharper, stage representation is more forward. 
The Raytheons sound a bit more linear/mid centered and wetter with a resulting larger stage. The mids are to die for, the treble is refined and very detailed. This is probably the most detailed sound I have ever heard on the MKIII & MKIVSE. Instruments have a good volume and presence, imaging is a bit better than with the Sylvanias. 
In summary, I will probably stick with the 6SN7s as driver tubes and the HD800 as my preferred setup and keep the Raytheons in for now. Driver tubes were C3GS.


----------



## MIKELAP

acapella11 said:


> Re MKIVSE and 6SN7 powertubes: I have kept on listening to the two pairs of 6SN7 tubes and just wanted to share a few impressions.
> Both are 6SN7WGT brown base tubes and both fit very well with the MKIVSE (for MKIII, I prefer the more vibrtantly sounding 5687) and HD800. Both sound more refined, darker and detailed than the 5687.
> The Sylvanias present more bass and treble than the Raytheon, sound is more V-shaped and exciting. Treble is a bit harder, bass more "visceral", mids are a bit sharper, stage representation is more forward.
> The Raytheons sound a bit more linear/mid centered and wetter with a resulting larger stage. The mids are to die for, the treble is refined and very detailed. This is probably the most detailed sound I have ever heard on the MKIII & MKIVSE. Instruments have a good volume and presence, imaging is a bit better than with the Sylvanias.
> In summary, I will probably stick with the 6SN7s as driver tubes and the HD800 as my preferred setup and keep the Raytheons in for now. Driver tubes were C3GS.


 
 Do you mean stick with 6SN7 as POWER tubes not drivers .Can you say so far if your upgrading to the MK4SE is a big jump or moderate in sound quality .Also  do parts used seem to be of a better quality to explain the difference in price .I use the HD800 with my MK3 i think you said the MK4 SE was more neutral then the MK3 meaning ,a cleaner more detailed sound ?  does it loose warmt., or is it just a different sounding altogether .Thanks


----------



## gibosi

I have been curious about 6F8Gs for some time so when I recently stumbled on a pair, an RCA and a Ken-Rad, for $15, I couldn't resist. For those who are new to the 6F8G, it is considered the direct predecessor of the 6SN7.
  
 A picture of the Ken-Rad 6F8G, dated 1942, and a Ken-Rad 6SN7, dated 1945. The staggered plates and micas appear almost identical, but of course, the 6F8G bottle is significantly larger and there is a top cap connected to the grid of the first section. 
  

  
 Assuming one already has adapters to allow the use of 6SN7s, it is then necessary to purchase an additional adapter to allow a 6F8G to be used in a 6SN7 socket, like so:
  

  
 I haven't taken the time to compare these tubes, but going from memory, used as a driver in my LD 1+, the 6F8G has the same big bass, smooth midrange and highs as the 6SN7. A terrific tube. For about $8, I am real pleased.


----------



## Acapella11

mikelap said:


> Do you mean stick with 6SN7 as POWER tubes not drivers .Can you say so far if your upgrading to the MK4SE is a big jump or moderate in sound quality .Also  do parts used seem to be of a better quality to explain the difference in price .I use the HD800 with my MK3 i think you said the MK4 SE was more neutral then the MK3 meaning ,a cleaner more detailed sound ?  does it loose warmt., or is it just a different sounding altogether .Thanks


 

 Yes, powers, not drivers. Loses warmth, some more details and stage. Moderate jump but noticeable and because the synergy with 6SN7 is better, I'd  say the jump just got bigger. For me now, it was worth the money.


----------



## MIKELAP

Was listening to my MK3 with 6SN7Russian tubes equi.  and  C3g's  and comparing against my WA6 with Brimar 5Z4G rectifier  and RCA 6SN7 gray glass when you switch over from amp to amp over and over and cant hear a difference i guess there very similar sounding lol . One thing im very shure of  6SN7 AND C3G'S dont like 25 ohms Denons lots of distortion .but with the WA6 with swith on for low impedance HP no distortion but to much bass this is with the JOE SPILGOE Hi Res track sounds much much better with the HD800 not much love for the poor Denon's anymore


----------



## Acapella11

mikelap said:


> Was listening to my MK3 with 6SN7Russian tubes equi.  and  C3g's  and comparing against my WA6 with Brimar 5Z4G rectifier  and RCA 6SN7 gray glass when you switch over from amp to amp over and over and cant hear a difference i guess there very similar sounding lol . One thing im very shure of  6SN7 AND C3G'S dont like 25 ohms Denons lots of distortion .but with the WA6 with swith on for low impedance HP no distortion but to much bass this is with the JOE SPILGOE Hi Res track sounds much much better with the HD800 not much love for the poor Denon's anymore


 
  
 Yeah, low Z cans are not good with 6SN7 power tubes for MKIII / MKIV but with higher impedance cans, they shine. Should be good with Sennheisers and Beyerdynamics, matches the HD800 well. With the MKIVSE, the 6SN7 power tubes light up more, meaning sound more lively .
 Yeah, I experience the exactly same choice between the Hifiman and the HD800 as you with Denons or HD800. Surprising findings comparing MKIII and theWA6!


----------



## mordy

Hi A11,
  
 Like you, I enjoyed the 6SN7 as power tubes. However, replacing them with 2.5A tubes (6AS7/6080) made a big difference - more of everything, especially bass impact.
  
 Using these tubes necessitates using special adapters, an external power supply and voltage regulator, but IMHO, it is well worth the extra effort.


----------



## sgbwill2

mikelap said:


> Was listening to my MK3 with 6SN7Russian tubes equi.  and  C3g's  and comparing against my WA6 with Brimar 5Z4G rectifier  and RCA 6SN7 gray glass when you switch over from amp to amp over and over and cant hear a difference i guess there very similar sounding lol . One thing im very shure of  6SN7 AND C3G'S dont like 25 ohms Denons lots of distortion .but with the WA6 with swith on for low impedance HP no distortion but to much bass this is with the JOE SPILGOE Hi Res track sounds much much better with the HD800 not much love for the poor Denon's anymore


 
 I also noticed this. My denon 5k's and my other low impedence cans produced some pretty bad bass distortion when using 6sn7's and 6f8g's but with the 650's they sounded great (unless I cranked up the volume to 80%+). After replacing the 6sn7's with the 5687's the sound wasn't much different yet I was able to use low impedence cans without any distortion even at really high listening levels which makes them the better tubes in the LD in my opinion


----------



## MIKELAP

sgbwill2 said:


> mikelap said:
> 
> 
> > Was listening to my MK3 with 6SN7Russian tubes equi.  and  C3g's  and comparing against my WA6 with Brimar 5Z4G rectifier  and RCA 6SN7 gray glass when you switch over from amp to amp over and over and cant hear a difference i guess there very similar sounding lol . One thing im very shure of  6SN7 AND C3G'S dont like 25 ohms Denons lots of distortion .but with the WA6 with swith on for low impedance HP no distortion but to much bass this is with the JOE SPILGOE Hi Res track sounds much much better with the HD800 not much love for the poor Denon's anymore
> ...


 
 I noticed this only with the 6SN7  as power tubes with other power tubes no problems


----------



## superdux

funnily my T50RP distorts too with the 6SN7 but i plugged in some low ohm IEMs and they are just fine. Thinking about getting an SS amp for all my low ohm HPs.


----------



## i luvmusic 2

superdux said:


> funnily my T50RP distorts too with the 6SN7 but i plugged in some low ohm IEMs and they are just fine. Thinking about getting an SS amp for all my low ohm HPs.


 
 Or a LD 1+? mine doesn't HUM for my low Z Sony XB700 even quieter background with the  C3g's.


----------



## Nic Rhodes

6F8G are a lovely tube but can be occasionally  noisey in comparison to many 6SN7GTs. When the latter were made, they had really nailed the manufacture and consistency making the distortion fron 6SN7GTs both low and consistent in comparison to all mediuum mu tubes, as well as noise.


----------



## MIKELAP

acapella11 said:


> mikelap said:
> 
> 
> > Was listening to my MK3 with 6SN7Russian tubes equi.  and  C3g's  and comparing against my WA6 with Brimar 5Z4G rectifier  and RCA 6SN7 gray glass when you switch over from amp to amp over and over and cant hear a difference i guess there very similar sounding lol . One thing im very shure of  6SN7 AND C3G'S dont like 25 ohms Denons lots of distortion .but with the WA6 with swith on for low impedance HP no distortion but to much bass this is with the JOE SPILGOE Hi Res track sounds much much better with the HD800 not much love for the poor Denon's anymore
> ...


 
 Again i must say this about MK3 sounding similar to WA6  i achieve this using MK3 as preamp with Burson Conductor


----------



## gibosi

It's been a pretty quiet week here recently.... But I have more tubes for you! 
  
 Received an Amperex 6463 and a Thomson 5687 here recently:
  
 Below, to the left, the Heelen-made Amperex 6463. Even though it sports a halo getter, it appears that this tube was manufactured in 1959 - "Cd1 ⊿9G". For comparison purposes, an early 1960's Telefunken 6463 on the right.
  

  
 Below to the left, a Thomson 5687, made in France - "7202" = February, 1972. For comparison purposes, an early 1960's Sylvania 5687 on the right.
  

  
 I am pleased to note that both light up and play, but plan to burn them in for a while before I do any serious listening....


----------



## i luvmusic 2

To make a bit more interesting here(i know it's off topic)How is your Glenn amp coming?


----------



## gibosi

It is my understanding that Glenn is currently working on a 300B and my OTL is next in the queue, so I hope to have it soon. That said, Glenn has a full-time job so building amps has to be squeezed into his evenings and weekends.....


----------



## Acapella11

Re Sylvania 6SN7WGT brown base as power tubes: It seems these tubes need more time to burn in than I have given so far, as the stage seems to extend now a bit more and the sound becomes more detailed. Overall, it also sounds gentler than before, still with more trebleand bass presentation than the Raytheon 6SN7WGT brown base. This story may continue, lol but I am more inclined to the Sylvania now and it really does sound damned good with the MKIVSE and C3GS driver tubes.
  
 Quote:


gibosi said:


> It's been a pretty quiet week here recently.... But I have more tubes for you!
> 
> Received an Amperex 6463 and a Thomson 5687 here recently:
> 
> Below, to the left, the Heelen-made Amperex 6463. Even though it sports a halo getter, it appears that this tube was manufactured in 1959 - "Cd1 ⊿9G". For comparison purposes, an early 1960's Telefunken 6463 on the right.


 
  
 Interesting, the 6463 has 0.6 as opposed to 0.9 A heater current of the 5687 and looks pin compatible.Found on Audioasylum that they should sound better than the 5687 and there are also significantly fewer offers on ebay. Curious to hear your LDI driver tube impressions.


mordy said:


> Hi A11,
> 
> Like you, I enjoyed the 6SN7 as power tubes. However, replacing them with 2.5A tubes (6AS7/6080) made a big difference - more of everything, especially bass impact.
> 
> Using these tubes necessitates using special adapters, an external power supply and voltage regulator, but IMHO, it is well worth the extra effort.


 
  
 Hi Mordy, Yes thanks, I am aware of that. I consider to rather upgrade to an amp that was designed to use tubes with specifications exceeding those of the LD, just because these would be so much away from the original design that using a purpose build amp would properly give me back in sound what those tubes cost and their potential.


----------



## gibosi

acapella11 said:


> Interesting, the 6463 has 0.6 as opposed to 0.9 A heater current of the 5687 and looks pin compatible.Found on Audioasylum that they should sound better than the 5687 and there are also significantly fewer offers on ebay. Curious to hear your LDI driver tube impressions.


 
  
 Unfortunately, the 5687 and 6463 are not pin compatible. The 6350, 6463 and ECC813 all have the same pin-out, and again, it is different than the 5687, 6900, 7044 and E182CC/7119.
  
 To date, I have found 6463 manufactured by GE, Philips (Heerlen) and Telefunken (Ulm). The vast majority of 6463 currently available on eBay are GEs. Telefunkens and Philips do popup from time to time, but are not common. I purchased the Philips from Brent Jessee for $25, which seems pretty reasonable to me. However, Brent Jessee charges $30 to ship overseas, so those living in Europe may want to see if they can find these European tubes on that side of the pond.
  
 While I haven't had a chance to listen closely to the Philips 6463, I can say that the Telefunken is a terrific tube. The transparency and imaging are exceptional which I believe is somewhat due to the Telefunken's airy highs. I briefly compared a 1975 Reflector 6N32P with the Telefunken, and that airiness was the most noticeable difference.


----------



## i luvmusic 2

gibosi said:


> It is my understanding that Glenn is currently working on a 300B and my OTL is next in the queue, so I hope to have it soon. That said, Glenn has a full-time job so building amps has to be squeezed into his evenings and weekends.....


 
 I'am interested in his amp i want a amp that can use all/most of my existing tubes.
  
 Thanks gibosi!


----------



## mordy

Hi A11,
  
 I can understand your reluctance to mod the LD MKIII/IV to use 2.5A power tubes, but it isn't really that difficult. First of all, you already have the adapters for using 6SN7 tubes as power tubes. You will need a pair of 6AS7/6080 tubes. Some of these tubes are very inexpensive, well less than $10 each.
  
 Then you need a pair of socket savers/extenders to connect the external power source to the heaters. These socket extenders can be bought for less than $7 for a pair. A 15A computer PS can be found for $30-35 on sale, and finally, a 15A voltage regulator costs around $13.
  
 So we have an investment of some $75 - isn't this much less than $560 or more for a new amp?
  
 On the other hand, Hypnos 1 feels that the Elise is significantly better, so this may be the way to go.....
  
 I have yet to hear from other owners of the Elise, and new orders are pushed back to Feb-March.


----------



## gibosi

I am still hoping that someone will try the 6BL7 and/or 6BX7 as power tubes. While those who have tried the 6AS7s believe them to be the best power tube they have tried, the fact remains that the LD cannot provide enough plate current for these tubes to really shine. The 6BL7/6BX7 heaters draw about 1.5 amps each, so they will still need an external power supply, but given that the plate current requirement is lower than the 6AS7, there is a good chance they will be a better match for the LD. And if so, they may well shine.
  
 But of course, the only way for us to know is if people try both the 6AS7 and 6BL7/6BX7 and tell us....


----------



## mordy

Hi Gibosi,
  
 Took u up on the challenge. I have a "near" pair of Sylvania 6BL7GT  (Automatic Radio 7/51 and Philco 11/52). From my days of experimenting with these type of 1.5A tubes as driver tubes, I remember that the 6BX7 sounded better, but i only have one such tube. The driver tubes were the Siemens C3gS.
  
 From experience I know that the voltage at the voltage regulator usually reads higher than at the tube pins. For my 6080 Sylvania tubes i need 6.85V at the regulator to get 6.3V at the tube pins. Did not want to fiddle with the voltage regulator setting trying the 6BL7GT tubes - the voltage at the tube pins read 6.5V, but I decided that this small difference should not affect the sound.
  
 The sound can best be described as nice - good mid range and treble, but the bass lacked impact, detail and slam. Overall, there was a lack of liveliness to the sound.
  
 Which all goes to show that there is no substitute for horsepower, or whatever.
  
 Am I the only one who likes Sylvania early 1960's 6080 tubes as power tubes? To me they sound better than the RCA 6AS7, Chatham 6AS7, and RCA, Chatham,  GE  and even Sylvania Gold Brand (1970's?) 6080 tubes.


----------



## buldogge

Hey Guys...I've been slowly making my way thru reading this thread (maybe 1/6 way thru so far)...have begun ordering some different/new tubes to try (already have some various 6AK5s, Mullard EF91 and 92s, and Soviet tubes):
  
 Tung Sol, JAN RCA, and JAN GE 6CB6As
 Sylvania 6GY6s
 Sylvania 6GM6s
 GE 8136s
 GE 6EW6s
  
 (2) Questions...
  
 1) Any other "must try" tubes, without jumping sockets or making adaptors?  Amperex Bugle Boy EF91s??  I'm mainly using HD650s and running from a '13 iMac thru a Dac the Destroyer into the LB MKII...Power tubes are 6H6N-U  (6N6P-I).
  
 2) Any ideas/help on trying to install a switch to replace the pin jumpers on a MKII?  Having distortion/power thump issues...I've started a thread, here:
  
 http://www.head-fi.org/t/750997/little-dot-mkii-modification#post_11238270
  
 TIA
 -Mark in St. Louis


----------



## gibosi

buldogge said:


> 1) Any other "must try" tubes, without jumping sockets or making adaptors?  Amperex Bugle Boy EF91s??  I'm mainly using HD650s and running from a '13 iMac thru a Dac the Destroyer into the LB MKII...Power tubes are 6H6N-U  (6N6P-I).


 
  
 6HM5 - the tall bottles. Or if you are willing to do a little tube mutilation, that is removing pins 5 and 6, 1950's era 6AQ6/6AT6/6AV6 are also very good.


----------



## MIKELAP

buldogge said:


> Hey Guys...I've been slowly making my way thru reading this thread (maybe 1/6 way thru so far)...have begun ordering some different/new tubes to try (already have some various 6AK5s, Mullard EF91 and 92s, and Soviet tubes):
> 
> Tung Sol, JAN RCA, and JAN GE 6CB6As
> Sylvania 6GY6s
> ...


 
 Dont know if MK2 is same as MK3 but i use longer jumpers with a pair of longnose pliers once you try this you wont need anything else that's what i use now and i dont freak out anymore everytime i change jumpers around .


----------



## mordy

Hi buldogge,
  
 Since it seems that adding a switch and wires to the jumpers introduces hum, the easiest way to avoid it is to make "quick change" jumpers.
  
 You can buy 2.54mm jumpers with a long handle and then glue on a paper match or add some pieces of plastic (I used pieces from the mechanism of a roller pen) to make a long handle for the jumper. This, and a little flashlight to make it easier to see, makes changing the jumpers much easier. Here is one link for long handle jumpers (there are many more):
  
 http://www.ebay.com/itm/10-pieces-of-Standard-Size-2-54mm-Computer-Jumper-with-Long-Handle-Black-Color-/251626867373?pt=US_Computer_Case_Accessories_Tool_Kits&hash=item3a96214aad
  
 Here is a link to my long handle jumper set up:
  
 http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/3285#post_9860068


----------



## buldogge

I assume you are referring to the Yugoslavian 6HM5s?
  
 I'm was also going to try some of the 6AQ6s...need to shoot an email off to a certain eBay bulk tube seller and see what he actually has...Worth it if I get the Yugo 6HM5s?
  
 What about 6J4?
  
 Any particular make/model to look for in the the 6AQ6 family or 6J4???
  
 TA
 -Mark
  
 Quote:


gibosi said:


> 6HM5 - the tall bottles. Or if you are willing to do a little tube mutilation, that is removing pins 5 and 6, 1950's era 6AQ6/6AT6/6AV6 are also very good.


----------



## buldogge

^^^Thanx Mordy and MIKELAP...Any idea if these are readily available in the US?  Someplace like Microcenter, perhaps??
  
 The MKII doesn't have the holes...but...it will shortly.
  
 I guess I'll just find a rubber plug for the hole I made for the switch in back.
  
 I just noticed that the MKII jumpers may be different...possibly mini 2mm as opposed to the normal 2.54mm of the MKIII...hmm.
  
 TA
 -Mark


----------



## gibosi

buldogge said:


> I assume you are referring to the Yugoslavian 6HM5s?
> 
> I'm was also going to try some of the 6AQ6s...need to shoot an email off to a certain eBay bulk tube seller and see what he actually has...Worth it if I get the Yugo 6HM5s?
> 
> ...


 
  
 The Yugoslavian 6HM5s are very popular here. I also like the tall-bottle GEs and others have like the tall-bottle Sylvanias. So our collective experience suggests that any of the tall bottles are worth a try.
  
 A number of us tried 6J4 and the mil-spec 8532 version, and didn't much like it. That said, they are cheap. 
  
 For the 6AQ6 / 6AT6 / 6AV6, I suggest you look for any brand with a box-like structure mounted on top of the upper mica. For example, a pair of GEs and a couple posts down, a pair of Sylvanias.
  
 http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/3360#post_9870568


----------



## buldogge

Thanx again...I've sent a note to an eBay seller asking for pics of the 6AQ6s and checking to see if he has any 6HM5s.
  
 -Mark
  
 Quote:


gibosi said:


> The Yugoslavian 6HM5s are very popular here. I also like the tall-bottle GEs and others have like the tall-bottle Sylvanias. So our collective experience suggests that any of the tall bottles are worth a try.
> 
> A number of us tried 6J4 and the mil-spec 8532 version, and didn't much like it. That said, they are cheap.
> 
> ...


----------



## buldogge

Another question...Maybe for those who own, or have owned, both... Do you notice a major difference between the MKII, MKIII, and MKIV in performance...once the tube rolling starts???
  
 I'm thinking of bringing my MKII to the office (would share space with a SS Schiit stack) and getting a MKIII or IV for home....Gotta put all these new tubes to use!
  
 Thoughts???
  
 TIA
 -Mark


----------



## buldogge

Guys...Any idea if the 6Hk5 or 6HQ5 is a compatible/crossover for the 6HM5???
  
 TIA
 -Mark


----------



## gibosi

buldogge said:


> Guys...Any idea if the 6Hk5 or 6HQ5 is a compatible/crossover for the 6HM5???


 
  

 According to the Radiomuseum site, 6HA5 and 6HQ5 are "Normally replaceable-slightly different". In practice, they perform identically in our LDs. And again, the tall-bottle tubes - 6HM5, 6HA5 or 6HQ5 - typically sound better than the small-bottle.
  
 http://www.radiomuseum.org/tubes/tube_6hm5.html


----------



## buldogge

Yeah...I was just making sure I was reading the socket charts correctly...the 6HQ5 looks identical, with just a .01 higher amperage.
  
 TA
 -Mark
  
 Quote:


gibosi said:


> According to the Radiomuseum site, 6HA5 and 6HQ5 are "Normally replaceable-slightly different". In practice, they perform identically in our LDs. And again, the tall-bottle tubes - 6HM5, 6HA5 or 6HQ5 - typically sound better than the small-bottle.
> 
> http://www.radiomuseum.org/tubes/tube_6hm5.html


----------



## Acapella11

Hi buldogge, also consider to replace your power tubes. Easiest and useful replacement would be the 6N6P-IR.


----------



## buldogge

Hey Acapella11...I have bookmarked some IRs...although I have had good luck with the replacement  Soviet OTK 6N6P-Is so far.
  
 -Mark
  
 Quote:


acapella11 said:


> Hi buldogge, also consider to replace your power tubes. Easiest and useful replacement would be the 6N6P-IR.


----------



## Zeejet

I currently own pairs of Voshkhod 6J1P-EV from 1978, GE JAN 5654W from1988 (I think), and WE 408A.
  
 I have not tried the WE 408A's yet but I was disappointed by the Voshkhods, which seem to be universally lauded here. I found them harsh and weak on low end. The GE JAN 5654W's were far better. 
  
 I'm really skeptical about things like long burn-in times (sounds like audiophile placebo nonsense). I've spent about 20 hours on the Voshkhods and they still sound unpleasant. Does the year of production matter?


----------



## michaelkeeney

zeejet said:


> I currently own pairs of Voshkhods from 1978, GE JAN 5654W from1988 (I think), and WE 408A.
> 
> I have not tried the WE408's yet but I was disappointed by the Voshkhods, which seem to be universally lauded here. I found them harsh and weak on low end. The GE JAN 5654W's were far better.
> 
> I'm really skeptical about things like long burn-in times (sounds like audiophile placebo nonsense). I've spent about 20 hours on the Voshkhods and they still sound unpleasant. Does the year of production matter?


 
 What headphones are you using?  From what I've read on here, different cans sometimes call for different tubes… Gibosi was schooling me on this just the other day, lol.


----------



## Zeejet

michaelkeeney said:


> What headphones are you using?  From what I've read on here, different cans sometimes call for different tubes… Gibosi was schooling me on this just the other day, lol.


 
  
 Beyer 880 DT Pro.
  
 THe GE JAN 5654W's are a lot smoother in tone while the Voshkhods can sound shrill in the highs (even if they do seem to extend further). Also, Voshkhod 6J1P-EV's are dirt cheap from what I can tell (anywhere between $3-15 per pair), but so are GE JAN's.


----------



## michaelkeeney

zeejet said:


> Beyer 880 DT Pro.
> 
> THe GE JAN 5654W's are a lot smoother in tone while the Voshkhods can sound shrill in the highs (even if they do seem to extend further). Also, Voshkhod 6J1P-EV's are dirt cheap from what I can tell (anywhere between $3-15 per pair), but so are GE JAN's.


 
 Listen to your ears… they won't lie to you.  
  
 If you are okay with spending a little money (and have patience to wait for the shipping) a lot of people are saying the end game tube for the LD is the C3g.  It's a Siemens tube, and you'll need an adapter and extender.  I can't tell you how good they are from experience yet, as I'm still waiting on my adapters, but the things people are saying on there about them would lead me to believe they might in fact kick ass.


----------



## buldogge

If you want to stick with the EF95s...I've found the Tung Sols 6AK5s to be a real nice for small $...Several guys mentioned the GE 6096 CT...I've got a pair of those, on the way, to try.
  
 If you're willing to delve into the EF91/92s...The Mullards are renowned for their smooth/warm delivery...I like my CV131s a lot.
  
 Lastly...I'm looking forward to trying the 6CB6As, 6HQ5s, and M8083s.
  
 Basically...as evidenced by this thread...there is a BIG world of tube rolling possibilities with these LDs!
  
 You can have a bit of fun/explore the soundscape for small money, really.
  
 Good luck.
  
 -Mark in St. Louis
  
 Quote:


zeejet said:


> Beyer 880 DT Pro.
> 
> THe GE JAN 5654W's are a lot smoother in tone while the Voshkhods can sound shrill in the highs (even if they do seem to extend further). Also, Voshkhod 6J1P-EV's are dirt cheap from what I can tell (anywhere between $3-15 per pair), but so are GE JAN's.


----------



## buldogge

Anyone have any thoughts regarding the MKIII or IV, compared to the MKII, in relation to doing some tube rolling???
  
 TA
 -Mark
  
 Quote:


buldogge said:


> Another question...Maybe for those who own, or have owned, both... Do you notice a major difference between the MKII, MKIII, and MKIV in performance...once the tube rolling starts???
> 
> I'm thinking of bringing my MKII to the office (would share space with a SS Schiit stack) and getting a MKIII or IV for home....Gotta put all these new tubes to use!
> 
> ...


----------



## ToTje

About the Voshkhods: I absolutely love these tubes. The higher mids sometimes get a very OVERrealistic sound; better than the real thing, so to speak.
 The bass also goes VERY deep. I especially love how the deeper tones of string instruments sound with these, although I must say that after an evening of listening to '80s pop-music, the bass-guitars do get quite tiring since they get quite a bit emphasis.


----------



## Acapella11

The Voskhods have a very long burn in time, in which the treble tames down. It can take 90 hours.


----------



## Zeejet

acapella11 said:


> The Voskhods have a very long burn in time, in which the treble tames down. It can take 90 hours.


 
 Is this pretty universally agreed upon? It seems like hocus pocus to me (like expensive cables or high-end op-amp rolling). I did notice burn-in affecting my GE JAN 5654W's but it only took 5-6 hours. How can another tube take almost 100 hours?
  
 Also, here is a noob question: do I need to be playing sound in order to burn-in? Or just have the amp ON? Furthermore, do I need headphones connected if burn-in requires there to be a signal going to the amp?


----------



## ToTje

zeejet said:


> Is this pretty universally agreed upon? It seems like hocus pocus to me (like expensive cables or high-end op-amp rolling). I did notice burn-in affecting my GE JAN 5654W's but it only took 5-6 hours. How can another tube take almost 100 hours?
> 
> Also, here is a noob question: do I need to be playing sound in order to burn-in? Or just have the amp ON? Furthermore, do I need headphones connected if burn-in requires there to be a signal going to the amp?


 
 As I understood, there has to be music playing, preferrably a bit above normal listening levels and I've read that you do need a headphone connected to the amp, but I'm not really sure why.
  
 Also, people say you just should listen to the music when you're giving the tubes a burn-in, because of their limited life-span: it's a shame to waste listening time.  Also keep about 8 hours continuous music as a max and then switch the amp off for a while to let the tubes cool down.


----------



## Acapella11

zeejet said:


> Is this pretty universally agreed upon? It seems like hocus pocus to me (like expensive cables or high-end op-amp rolling). I did notice burn-in affecting my GE JAN 5654W's but it only took 5-6 hours. How can another tube take almost 100 hours?


 
  
 It is pretty much a common agreement for this tube. No hocus pocus. Some report burn in times of over 100 hours.
  


> Also, here is a noob question: do I need to be playing sound in order to burn-in? Or just have the amp ON? Furthermore, do I need headphones connected if burn-in requires there to be a signal going to the amp?


 
  
 Burn in while playing music. Don't worry about listening to it though, these tubes will last you a long time.


----------



## jaywillin

zeejet said:


> Is this pretty universally agreed upon? It seems like hocus pocus to me (like expensive cables or high-end op-amp rolling). I did notice burn-in affecting my GE JAN 5654W's but it only took 5-6 hours. *How can another tube take almost 100 hours?*
> 
> Also, here is a noob question: do I need to be playing sound in order to burn-in? Or just have the amp ON? Furthermore, do I need headphones connected if burn-in requires there to be a signal going to the amp?


 
  
  


acapella11 said:


> *It is pretty much a common agreement for this tube. No hocus pocus.*
> 
> 
> *Burn in while playing music.*


 
_*not sure of the exact reasoning, but guess would be, they are russian military/rocket tubes*_
  
  
*yes*
*and yes, well actually, i know i listen to music*


----------



## mordy

Hi Zeejet,
  
 Your ears don't lie. Just as you, I was skeptical about burn in, but learned through experience that it is usually needed for new tubes. Different tubes need different times, and the Voskhod require more time than most, perhaps 110 hours. After this time they sound softer and more mellow, and there is less treble harshness.
  
 Jlab earbuds has a special burn in track that plays as long as you want - link below.
  
 I think that the industry standard for burn in time is 48 hours (if there is such a standard).
  
 Some tubes change dramatically during burn in, others less, but I think that they all need it. Why? I think that some impurities in the tube need to burn off, and the tube has to stabilize.
  
 http://www.jlabaudio.com/pages/audio-burn-in


----------



## Zeejet

Thanks for all the tips! I will try this out when I leave for work every morning until I log enough hours.


----------



## buldogge

Trying some GE 6EW6 out right now...first impressions are pretty good...nice full sound...slightly strong mids.
  
 Think I'll try the Tung Sol 6CB6As next...
  
 -Mark in St. Louis


----------



## MIKELAP

zeejet said:


> Thanks for all the tips! I will try this out when I leave for work every morning until I log enough hours.


 
 Personnally i would not leave amp on  all day if there's nobody in the house you never know ,second when your burning in amp plug in  an old pair of HP if a tube or anything else would happen its not going to be your best pair of HP that will go up in smoke, just my two cents


----------



## Acapella11

Re 6SN7 vs 5687 power tubes:
  
 Just comparing Sylvania 6SN7WGT and Tung Sol 6587 WA: I am starting to believe that the reason why the 5687 sounds more vibrant at least partially is because it drives the HD800 better than the 6SN7WGT. I am going to look into this more next week but using the 5687WA certainly has its advantages.

  


> Originally Posted by *Zeejet*
> 
> 
> 
> Thanks for all the tips! I will try this out when I leave for work every morning until I log enough hours.


 
  
 I have run the LD MKIII at RT in a non-cluttered space all day without issues, even though it was suggested to operate it only 8 h without interruption.


----------



## Rossliew

mikelap said:


> Personnally i would not leave amp on  all day if there's nobody in the house you never know ,second when your burning in amp plug in  an old pair of HP if a tube or anything else would happen its not going to be your best pair of HP that will go up in smoke, just my two cents


 
  
  


acapella11 said:


> I have run the LD MKIII at RT in a non-cluttered space all day without issues, even though it was suggested to operate it only 8 h without interruption.


 
  
 I dare not leave it on all day for fear of something shorting in the circuitry thereby causing a fire...


----------



## Shrew

Hello, I recently purchased a Little Dot MKIII using the (6H30) and (M8100 / CV4010) tubes. I find the treble a bit harsh and grainy? As well as the instrument separation lacking behind the Magni. Which tubes give the best instrument separation/detail and smooth treble?
  
 I was looking into the *Mullard M8161/CV401* how are those compared to the M8100? I know I'd have to change the jumpers.
  
 What else should I look into?


----------



## gibosi

shrew said:


> Hello, I recently purchased a Little Dot MKIII using the (6H30) and (M8100 / CV4010) tubes. I find the treble a bit harsh and grainy? As well as the instrument separation lacking behind the Magni. Which tubes give the best instrument separation/detail and smooth treble?
> 
> I was looking into the *Mullard M8161/CV401* how are those compared to the M8100? I know I'd have to change the jumpers.
> 
> What else should I look into?


 
  
 It has been a very long time since I listened to these tubes, but as best as I can remember, the M8161 (EF92) is a bit warmer and smoother than the M8100 (EF95 / 6AK5), so it might do the trick. I would also suggest the 6HM5. There are two versions of this tube, one short and squat and the other tall. Go for the tall ones. Sylvania and GE are good, as are Ei, which were manufactured in Yugoslavia.


----------



## Shrew

gibosi said:


> It has been a very long time since I listened to these tubes, but as best as I can remember, the M8161 (EF92) is a bit warmer and smoother than the M8100 (EF95 / 6AK5), so it might do the trick. I would also suggest the 6HM5. There are two versions of this tube, one short and squat and the other tall. Go for the tall ones. Sylvania and GE are good, as are Ei, which were manufactured in Yugoslavia.


 
  
 I can't find anything on the 6HM5 tube, was it a typo or are they extremely rare?


----------



## gibosi

shrew said:


> I can't find anything on the 6HM5 tube, was it a typo or are they extremely rare?


 
  
 http://www.radiomuseum.org/tubes/tube_6hm5.html
  
 It is not a typo and it is not rare. In fact is is cheap and fairly plentiful.
  
 http://www.ebay.com/sch/i.html?_from=R40&_sacat=0&_nkw=6hm5&rt=nc&LH_PrefLoc=2
  
 In my opinion it is better than either of the Mullards above and it is cheap. However not many people outside of Headfi know about this tube.  Set your LD for EF95 tubes and you are good to go.


----------



## TrollDragon

shrew said:


> I can't find anything on the 6HM5 tube, was it a typo or are they extremely rare?


 
 Like gibosi says the 6HM5 is not a typo but an excellent tube!
  

 4 Excellent Yugoslavians came to live in NS via PQ!
  

 Loaded up as driver tubes powering my T50RP's


----------



## Shrew

Well the price is certainly enticing. Do driver tubes need to be matched? Might go with this and see if it increases the instrument separation and make the treble less harsh.


----------



## TrollDragon

shrew said:


> Well the price is certainly enticing. Do driver tubes need to be matched? Might go with this and see if it increases the instrument separation and make the treble less harsh.


 

 LD amps do not require matched tubes.


----------



## Shrew

Should I buy the 6HM5 from thetubestore.com (they don't even tell you what brand or style it is short/tall) or just buy two different 6HM5 tubes from ebay? I don't see any matched pairs or sellers selling 2 in the States.


----------



## TrollDragon

I would just order some from this auction here, many of the people in this thread have bought from this seller.
 http://www.ebay.com/itm/6HM5-6HA5-EC900-export-quality-audio-triode-tube-NOS-FREE-SHIPPING-/300879467071
  
 Make him an offer, you might be able to get them for $6 each.


----------



## gibosi

shrew said:


> Should I buy the 6HM5 from thetubestore.com (they don't even tell you what brand or style it is short/tall) or just buy two different 6HM5 tubes from ebay? I don't see any matched pairs or sellers selling 2 in the States.


 
  
 If the tubestore can't even tell you if they are short or tall, then no, I would not encourage you to purchase from that vendor....
  
 But a question? Why the apparent aversion to foreign sellers?  For many here, the Yugoslavian Ei tubes purchased from Serbian vendors have been excellent buys....


----------



## Shrew

gibosi said:


> If the tubestore can't even tell you if they are short or tall, then no, I would not encourage you to purchase from that vendor....
> 
> But a question? Why the apparent aversion to foreign sellers?  For many here, the Yugoslavian Ei tubes purchased from Serbian vendors have been excellent buys....


 
  
 Would rather not wait 2 weeks for shipping. Does brand matter much? I think I'll go with http://www.ebay.com/itm/4-Olympic-6HA5-6HM5-Electronic-Vacuum-Tubes-in-Box-NOS-Matching-Set-/111572170113
  
 Edit: Went ahead and purchased 2 GE 6HM5s, hopefully it'll be as good as I've heard, or at least better than the M8100 for treble smoothness.


----------



## Nic Rhodes

The best one I tried were the EI ones recommended here.


----------



## MIKELAP

shrew said:


> Should I buy the 6HM5 from thetubestore.com (they don't even tell you what brand or style it is short/tall) or just buy two different 6HM5 tubes from ebay? I don't see any matched pairs or sellers selling 2 in the States.


 
 I bought mine from this seller pretty cheap he accepted around $22.00 for 4 tubes       
 http://www.ebay.com/itm/251611916081?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT


----------



## gibosi

shrew said:


> Edit: Went ahead and purchased 2 GE 6HM5s, hopefully it'll be as good as I've heard, or at least better than the M8100 for treble smoothness.


 
  
 As long as they both have the same construction, they should be fine. However, I have seen two very different GE 6HM5, one manufactured by Mullard and relabeled as a GE, and the other silk-screened "Made in Britain" from an unknown factory:
  
 Mullard (Mitcham) construction. Note the getter flashing covers almost half the tube.
  

  
 Unknown factory. Getter flashing covers less area than the Mullards and the plates are different
  

  
 Both these sound great, but as you might expect, they do not sound the same.
  
 Good luck!


----------



## Oskari

gibosi said:


> Unknown factory. Getter flashing covers less area than the Mullards and the plates are different


 
  
 Evidence of Philips tooling on the glass...


----------



## gibosi

Yes, these are a bit of a mystery. I can feel and see the four glass seams typical of Philips manufacture on the top, but there are no visible etched factory codes. While I think we can safely rule out one of GE's factories in the US, still the construction is different than the Mullard and Ei 6HM5s we have seen. And so for now, the factory is unknown....


----------



## BGRoberts

Oh manl
 Talk about an emotional rollercoaster!
 Last night I slept in my own bedroom and bed after 483 nights in hospital beds.
 Happy! Happy! Happy!
 Today I began to fire up my nightstand system which my wife had unplugged during my absence.
 Fired up the Squeezebox streamer and connected it to the network.  Plugged a pair of items in to check it was working.
 Perfect!
 Plugged in the Little Dot MKIII and flipped it on.
 Reached for the nodded Fostex T50's...
 Smoke comes pouring from the bottom vents on the LD3!!!
 Cr@p! Cr@p! CR@P!!


----------



## hypnos1

bgroberts said:


> Oh manl
> Talk about an emotional rollercoaster!
> Last night I slept in my own bedroom and bed after 483 nights in hospital beds.
> Happy! Happy! Happy!
> ...


 
  
 Hi BG.
  
 Glad to hear of your GOOD news, but not your BAD!...commiserations...
  
 All I can say is here's your opportunity to look at the Feliks-Audio 'Elise' that has eclipsed my MKIV SE big time... just a thought


----------



## WilliamLeonhart

This may seem crazy but I'd have to ask: can bad cables make the amps buzz? I have the LD I+ which always has a buzzing sound at a certain volume (about 20%), even when plugged into nothing. Later I tried removing the input cable (but still keep the amp and my headphones on), and the buzz is gone. I've noticed bad cables do drastically worsen the sound, but I don't know if I can constantly give out buzz...


----------



## Rossliew

williamleonhart said:


> This may seem crazy but I'd have to ask: can bad cables make the amps buzz? I have the LD I+ which always has a buzzing sound at a certain volume (about 20%), even when plugged into nothing. Later I tried removing the input cable (but still keep the amp and my headphones on), and the buzz is gone. I've noticed bad cables do drastically worsen the sound, but I don't know if I can constantly give out buzz...


 

 The input cable is from a DAC, which is plugged in and powered up, i presume? Could be a ground loop. i experienced that before or maybe its a non-related event..


----------



## WilliamLeonhart

rossliew said:


> The input cable is from a DAC, which is plugged in and powered up, i presume? Could be a ground loop. i experienced that before or maybe its a non-related event..


 
 Even when I unplug the DAC I can still hear the noise. What's weird is sometimes the noise only appears when I touch the volume knob, sometimes it appear right from the start when I turned on the I+. But then I do remember plugging the I+ into a friend's iphone and no hum was audible even at higher volume.
  
 I have opend the amp once to switch the jumper.


----------



## michaelkeeney

Just got my MUSES02 op amp installed, and really liking the difference.  The clarity is quite noticeable.  Thanks for the lead, gibosi.
  
 edit:  whoops, wrong thread, lol.


----------



## buldogge

Hey Guys...So, I've been playing with my accumulation of EF91/92/95 tubes...feeling out my favorites....really liking the GE 6EW6 and 6DK6 so far.
  
 I've also been slowly been making my way thru the thread (currently on page 446) and am probably going to buy or fab C3G and 6SN7 adaptor(s).
  
 Coupla questions...
  
 What are 6SN7s you guys have had luck with, in general, for power tubes...and...do the LDs need 6SN7...or 6SN7 GT...or GTA...or GTB...or will *any* of the family will work???
  
 TIA
 -Mark in St. Louis


----------



## Rossliew

buldogge said:


> Hey Guys...So, I've been playing with my accumulation of EF91/92/95 tubes...feeling out my favorites....really liking the GE 6EW6 and 6DK6 so far.
> 
> I've also been slowly been making my way thru the thread (currently on page 446) and am probably going to buy or fab C3G and 6SN7 adaptor(s).
> 
> ...


 
 Mark, any 6SN7 will work with the adapter in place, of course. Having said that, there will be sound differences between manufacturers and age. You need to try them out on your own to know what your personal preferences are. That said, try to source some Tung-Sol Mouse ears - they do sound awesome!


----------



## MIKELAP

buldogge said:


> Hey Guys...So, I've been playing with my accumulation of EF91/92/95 tubes...feeling out my favorites....really liking the GE 6EW6 and 6DK6 so far.
> 
> I've also been slowly been making my way thru the thread (currently on page 446) and am probably going to buy or fab C3G and 6SN7 adaptor(s).
> 
> ...


 
 Ive been using the 6SN7 ,Sylvania WGTA, KENRAD dark glass VT-231,GT, RCA GT VT-231 gray glass ,6H8C Russian tubes,Tung-Sol mouse ears, and gtb's also


----------



## buldogge

So...Would you guys say the 6SN7, as a power tube, is worth dealing with buying or building adapters, or do you think that subbing the 6N6P gold grids for -IRs would be "sufficient" (I know it's subjective, obviously).
  
 I'm leaning towards putting the money towards building a single adapter "plate" that handles the 6SN7 and C3G mods simultaneously.  (4) sets of sockets and (100) gold plated pins cost about 1/2 of what the pre-made adapters do...I'm sure I have some lexan/wire/standoffs/shrink tube/etc. lying around.
  
 Thoughts???
  
 -Mark


----------



## TrollDragon

buldogge said:


> So...Would you guys say the 6SN7, as a power tube, is worth dealing with buying or building adapters, or do you think that subbing the 6N6P gold grids for -IRs would be "sufficient" (I know it's subjective, obviously).
> 
> I'm leaning towards putting the money towards building a single adapter "plate" that handles the 6SN7 and C3G mods simultaneously.  (4) sets of sockets and (100) gold plated pins cost about 1/2 of what the pre-made adapters do...I'm sure I have some lexan/wire/standoffs/shrink tube/etc. lying around.
> 
> ...


 

 Build it up, Lexan makes a great adapter base for the ceramic gold pin sockets.


----------



## buldogge

^^^I'm dealing with a MKII (for now) so I will probably create a lexan sandwich with the pins potted to the bottom layer and the sockets bolted to the top layer.
  
 Solid or stranded wire connections?
  
 -Mark


----------



## buldogge

Can these 1.2mm pins be used, or is the .184mm pin diameter difference too great???
  
 http://www.ebay.com/itm/191401257016?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT
  
 Do we need to use 1mm, only?
  
 http://www.ebay.com/itm/100pc-gold-plated-Copper-tube-pins-for-you-DIY-Tube-adapter-or-others-17-1mm-/201098488778?pt=LH_DefaultDomain_0&hash=item2ed2676bca
  
 TIA
 -Mark


----------



## buldogge

OK...One more.
  
 Is the 6SN7 "worth" building adapters for, over using the "electrically identical" 6CG7???
  
 -Mark


----------



## MIKELAP

buldogge said:


> Can these 1.2mm pins be used, or is the .184mm pin diameter difference too great???
> 
> http://www.ebay.com/itm/191401257016?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT
> 
> ...


 
 i used 1mm but 1.2mm is only .007 thou. bigger .tube pins measure 1mm.


----------



## TrollDragon

buldogge said:


> ^^^I'm dealing with a MKII (for now) so I will probably create a lexan sandwich with the pins potted to the bottom layer and the sockets bolted to the top layer.
> 
> Solid or stranded wire connections?
> 
> -Mark


 
  
  


buldogge said:


> Can these 1.2mm pins be used, or is the .184mm pin diameter difference too great???
> 
> http://www.ebay.com/itm/191401257016?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT
> 
> ...


 

 Stranded for all connections is recommended as it is much more flexible and easier to work with. As for pins, most here have used 18AWG solid copper wire which works out to 0.8 mm, but those 1 mm ones would work just fine.
  
 I used old 7 pin tube bottoms for my adapter pictured above. I soldered the wires to the pins then filled the cut off  glass section with hot glue and shrink wrapped over that.


----------



## mordy

Hi buldogge,
  
_"Is the 6SN7 "worth" building adapters for, over using the "electrically identical" 6CG7???_"
  
 Don't bother with the 6CG7/6FQ7 tubes as power tubes - don't work well in the LDMKIII in my experience (I know u have a MKII).
  
 The 6SN7 are well worth exploring, and better than any 6N6P/6H30 variants in the LD amps IMHO.
  
 Good luck!


----------



## buldogge

Thanx for the replies guys...I'll stick with the 6SN7 adapter build plan.
  
 TD...How did you cut the glass of the tubes...glass cutter?  dremel? carbide "saw"?  I would love to just use the throw-away OE Chinese tubes and make for easy floating connectors!
  
 Any reasonable source for sockets in the US, or should I just order the gold ones from China for $7-10/pair??
  
 TA
 -Mark


----------



## MIKELAP

buldogge said:


> Thanx for the replies guys...I'll stick with the 6SN7 adapter build plan.
> 
> TD...How did you cut the glass of the tubes...glass cutter?  dremel? carbide "saw"?  I would love to just use the throw-away OE Chinese tubes and make for easy floating connectors!
> 
> ...


 
 i have been using these they are $30.00        http://www.ebay.com/itm/221065459067?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT


----------



## Acapella11

buldogge said:


> So...Would you guys say the 6SN7, as a power tube, is worth dealing with buying or building adapters, or do you think that subbing the 6N6P gold grids for -IRs would be "sufficient" (I know it's subjective, obviously).
> 
> I'm leaning towards putting the money towards building a single adapter "plate" that handles the 6SN7 and C3G mods simultaneously.  (4) sets of sockets and (100) gold plated pins cost about 1/2 of what the pre-made adapters do...I'm sure I have some lexan/wire/standoffs/shrink tube/etc. lying around.
> 
> ...


 
  
 Hi Mark, 6SN7 make great power tubes if you are having high impedance headphones. They work well my 300 ohm HD800 but not with my 38 ohm HE-500. For lower impedance, 5687 are better. Even though I prefer the 6SN7 with an MKIVSE over an MKIII, they produce a large amount detail nevertheless and I would prioritize them over -IR tubes. I have been using two brown base tubes: Raytheon 6SN7WGT and Sylvania 6SN7WGT and I recommend the Sylvania tubes.
  
 6SN7 as power tubes produce a very detailed sound with an excellent spatial perception. At the same time, they sound somewhat "harmonic" and gentle, without listening fatigue.


----------



## TrollDragon

buldogge said:


> Thanx for the replies guys...I'll stick with the 6SN7 adapter build plan.
> 
> TD...How did you cut the glass of the tubes...glass cutter?  dremel? carbide "saw"?  I would love to just use the throw-away OE Chinese tubes and make for easy floating connectors!
> 
> ...


 
  
 I wrapped the tube up tightly with a couple of wraps of electrical tape. Using a black cutting disk on your Dremel, you can go around the bottom of the tube slowly and gently allowing the glass to cool in between cuts. The base will crack if you cut too fast, hard or even look at it the wrong way so you might want want to prepare a few cheap tubes.
  
 Cut all the inner wires away that attach the tube parts to the pins. I just carefully cut the pins off I won't be using on the inside with flush cutters, right next to the little glass support post.
  
 The wires that go to the tube parts are spot welded to the pins, you will need to sand the pins a little and use a little flux to get them to take solder. Some bases will crack as well when you put heat to the pins so be aware of that as well. I had many a perfectly cut off tube have the base crack while soldering wires to the pins.
  
 Once your wires are soldered on, fill the hole with hot glue and apply a piece of shrink tube so it just slightly comes down over the edge of the bottom of the tube.
  
 Can be more effort than it is worth depending on how well the tube survives the cutting.
  
 I have also used a thick little disk of Lexan and drilled holes in it with the drill press in a B7G pattern which is 7 pins arranged at 45 degrees spacing in a 9.53 mm (3/8th inch) _diameter_ arc, really easy to make, just keep cutting the circle in half till you have 8 points on the circle. I used straightened paperclips as the pins with a loop on the top to attach a wire.
  
 Good luck either way you go.


----------



## buldogge

While I would love to use the tube bottoms, for simplicity sake, I think drilling the tube pin pattern and using either the gold plated pins or solid copper wire as pins would be an easier endeavor.
  
 18g wire is pretty much exact at 1.02 mm, 16g is 1.2mm of course...
  
 Time to order the sockets from China, I guess.
  
 On a side note...I rolled some 70's GE 6HQ5s in...really , really nice.  I was going to order some Yugo 6HM5s...but...I think I'll just leave those out now and concentrate on getting the C3Gs up and running.
  
 TA
 -Mark


----------



## buldogge

OK...On a different note.
  
 Be it coincidence, happenstance, or my ears...I seem to have settled on GE tubes after trying various E92s and E95s.
  
 I would say my current top (3) are:
  
 6HQ5
 6EW6
 6DK6
  
 I'm still waiting on some 6DT6As and 6CS6s, arriving today...as well as EF91 Mullard 8083s, coming from Germany.
  
 Anyway, while I wait on the parts for my C3G/6SN7 adapter plate build...
  
 Do you think it would be reasonable to assume a good starting point for a 6SN7 would be to find a GE variant?

 Any suggestions, within that realm??
  
 TA
 -Mark


----------



## Nic Rhodes

GE 6SN7GT polarise people opinions, a few people used to rave about the silver side getter version however there is a much bigger group that rate them at the bottom of the US makes pile. You might be better looking at Tung Sol, Ken Rad, Natiion Union, RCA and Sylvania first.


----------



## gibosi

buldogge said:


> OK...On a different note.
> 
> Be it coincidence, happenstance, or my ears...I seem to have settled on GE tubes after trying various E92s and E95s.
> 
> ...


 
  
 Like Nic, my opinion regarding GE 6SN7s is that they are not very good. In addition to the brands he suggested, I would add CBS/Hytron. These are quite good and often overlooked.
  
 In my experience, really good GE tubes are just not very common. The best I have found are 6AU6, 6AH6 and 1950's 6AV6. In my opinion, the GE 6AU6 is in fact better than the GE 6DT6A. Of the 6DT6, I liked the Tung-Sol and RCA the best.
  
 Also, your GE 6HQ5/6HM5 might not have been manufactured by GE. The two variations I have were manufactured using Philip's factory equipment and were not even manufactured in the US.
  
 http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/8925#post_11255228
  
 And speaking of GE tubes, today I received a couple of Sylvania 6463. The pictures weren't all that good and I doubted that they were actually made by Sylvania, but for $12 I figured it was worth the gamble. And as I suspected, these were manufactured by GE. To date, the only manufacturers of the 6463 I am aware of are GE, Philips (Heerlen) and Telefunken (Ulms). It appears that Sylvania never made this tube.
  
 Notice the whitish dots under the tube number. This is a dead giveaway that these were in fact manufactured by GE. If you don't see the dots, then the tube was manufactured elsewhere and rebranded by GE. In this case, I think it was a bit of good luck that one has an O-getter and the other a D-getter, so perhaps late 1950s for the older tube and 1960's or later for the newer one.
  
 The oldest one is burning in as I write this. And as the GE 6463 doesn't seem to get much love in the Google searches I have done, I don't expect it to be great, but time will tell.


----------



## buldogge

I'll check those 6HQ5s later tonight...I know they were marked 'Made in the USA'...not sure if that matters.
  
 As far as 6SN7s...I needed up buying a couple mismatched/re-labeled TS "Mouse-Ears" off eBay today.  One is labeled 'Admiral' and the other 'Rad-Tel'...the pictures weren't great, but they appear similar, if not identical.
  
 The 6DT6 assortment I just picked up (all NOS) are 3x GE (?), 2x RCA, 2x Zenith, 1x TS, and 1x CBS/Hytron.
  
 I also grabbed 2x RCA 6CS6s...Don't hold a lot of hope for these...been pretty disappointed in most of the RCAs I have tried.
  
 TA
 -Mark
  
 Quote:


gibosi said:


> Like Nic, my opinion regarding GE 6SN7s is that they are not very good. In addition to the brands he suggested, I would add CBS/Hytron. These are quite good and often overlooked.
> 
> In my experience, really good GE tubes are just not very common. The best I have found are 6AU6, 6AH6 and 1950's 6AV6. In my opinion, the GE 6AU6 is in fact better than the GE 6DT6A. Of the 6DT6, I liked the Tung-Sol and RCA the best.
> 
> ...


----------



## gibosi

buldogge said:


> I'll check those 6HQ5s later tonight...I know they were marked 'Made in the USA'...not sure if that matters.


 
  
 The "Made in Xxxxx" text on tubes is often a lie as is the brand. lol. I have seen Japanese-made tubes with "Made in Germany" and the Siemens brand, Soviet-made tubes with "Made in Gt Britain" and the Mullard brand, and on and on. After all, the silk-screened text and graphics were added after the tubes were manufactured, sometimes long after, even years, and the silk-screening was more about marketing and distribution than anything else.
  
 Etched markings, such as the GE "dots" and Philips manufacturing codes, were put into the glass during manufacture, and I find these to be quite reliable. Otherwise, you have to go by construction details - plates, micas, grid posts, getters, bottle shape, and so on.


----------



## bobbyblack

Hello guyz,

I want to say a special thanks to gibosi and mordy for the EI 6HM5 tubes recomandation!Only 2 days on them and the sound is allready amazing with my HD650(i came from Mullard's CV4010),good bass,rich sound,non sibilant,i say almost neutral-I dont know for other headphones but for Sennheiser HD650/600 they are v.good!


----------



## gibosi

Glad to know you are liking them. Even though we all have different ears and different gear, it seems that these inexpensive and relatively unknown tubes please almost everyone.
  
 Enjoy


----------



## bobbyblack

Thank you,i do!


----------



## buldogge

Hey gibosi...FWIW...The GE 6HQ5s I have also have 6HQ5 USA etching, along with (3) small dots and (1) larger dot below them....so I assume they are actual GE tubes.
  
 Also, both the 6DK6s and the 6EW6s, which I also like, have etched dots...hmm.
  
 -Mark
  
 Quote:


gibosi said:


> The "Made in Xxxxx" text on tubes is often a lie as is the brand. lol. I have seen Japanese-made tubes with "Made in Germany" and the Siemens brand, Soviet-made tubes with "Made in Gt Britain" and the Mullard brand, and on and on. After all, the silk-screened text and graphics were added after the tubes were manufactured, sometimes long after, even years, and the silk-screening was more about marketing and distribution than anything else.
> 
> Etched markings, such as the GE "dots" and Philips manufacturing codes, were put into the glass during manufacture, and I find these to be quite reliable. Otherwise, you have to go by construction details - plates, micas, grid posts, getters, bottle shape, and so on.


----------



## gibosi

Interesting! The 6HQ5 is slightly different than the 6HM5, so perhaps GE made the 6HQ5 here in the states and procured the 6HM5 from other manufactureres.....
  
 Edit: At about the same time we discovered the 6HM5, I was also exploring double triodes, so I didn't spend much time checking out all the 6HM5/6HA5/6HQ5/EC900 variants. I hope you will consider getting the Ei 6HM5s and some of the others and then let us know how they all compare. For those who do not wish to mod their LDs for more exotic tube rolling, impressions regarding how all these tubes compare could be very useful.


----------



## mordy

Hi bobbyblack,
  
 Happy to hear that you like the Ei tubes. Do your tubes start up with fireworks?
  
 Based on my several years of tube rolling experience, I have come to the conclusion that great tubes do not necessarily have to be expensive or rare. There are a lot of sellers out there that try to convince you otherwise, even perpetuating myths about special "great" tubes that only they sell.
  
 One of the great features of this thread is that you have a group of patient, helpful and dedicated people that give their honest unbiased opinions and advice, based on their personal hands on experiences.


----------



## bobbyblack

Hi mordy,

Yea lots of peoples here like to experiment things with passion and dedication for music and equipment and this is a good thing for newcomers like me and by the way i'm allready thinking of the next move on my LD3 ,probably 5687 power tubes !


----------



## Acapella11

Just felt like posting some pics of the power tubes I am mostly using at the moment. For the Sylvanias, most of the writing is gone. One can just about make out JAN CHS in capital on the glass and "van" from Sylvania. Maybe you have any comments whether these particular 6SN7WGT, from your experience, are good ones or not 
	

	
	
		
		

		
			





  On the Tung Sol 5687 WA tubes are a few numbers. I assume that in 3223, the 322 is the Tung Sol manufacturer code plus another 3, then there are different year/week of the year codes: 5643 (dark grey) and 5652 (white).


----------



## gibosi

acapella11 said:


> Just felt like posting some pics of the power tubes I am mostly using at the moment. For the Sylvanias, most of the writing is gone. One can just about make out JAN CHS in capital on the glass and "van" from Sylvania. Maybe you have any comments whether these particular 6SN7WGT, from your experience, good ones or not
> 
> 
> 
> ...


 
  
 The Sylvania 6SN7WGT is a great tube. I think it sounds very similar to the chrome dome 6SN7GT. Structurally, the only visible difference is the extra support rod in the mil-spec tube, but again, I don't notice any significant difference in sound. The only Sylvania 6SN7 I like better is the small-bottle 6SN7W from the 1940's, which has a bit more body in the mid-range.
  

  
 It appears your Tung-Sols were manufactured only 9 weeks apart in 1956, so very likely they are identical. And since you like the Sylvania 6SN7WGT, I suspect that you would also like the Sylvania 5687WA.
  
 Edit: Also, the 7044 and E182CC/7119 have the same pin-out as the 5687, so you might want to explore these types as well.


----------



## Acapella11

gibosi said:


> The Sylvania 6SN7WGT is a great tube. I think it sounds very similar to the chrome dome 6SN7GT. Structurally, the only visible difference is the extra support rod in the mil-spec tube, but again, I don't notice any significant difference in sound. The only Sylvania 6SN7 I like better is the small-bottle 6SN7W from the 1940's, which has a bit more body in the mid-range.
> 
> It appears your Tung-Sols were manufactured only 9 weeks apart in 1956, so very likely they are identical. And since you like the Sylvania 6SN7WGT, I suspect that you would also like the Sylvania 5687WA.
> 
> Edit: Also, the 7044 and E182CC/7119 have the same pin-out as the 5687, so you might want to explore these types as well.


 
  
 Hi Gibosi, thank you for the quick response and your suggestions.  Yeah, Sylvanias sound dynamic yet detailed with this lovely 6SN7 space perception.
 Sorry, if I made myself not clear with respect to the 5687 year numbers: My first tube on its own has the year codes 5643 in dark grey at the getter flash and 5652 in white under the main label, the other has 5609 in dark grey at the getter flash and but main label has almost completely disappeared.
  
 Edit: How are your Amperex 6463 tubes coming along?


----------



## buldogge

Any comment on later Sylvania 6SNTGTBs?
  
 They look similar to earlier ones...but...the "chrome dome" is smaller, for sure.
  
 I just picked up a "tested good" pair for $7...figure it was worth a shot.
  
 I'll stick with these and the TS Mouse Ears, for now, for preliminary testing with my 6SN7/C3G adapter plate.
  
 -Mark in St. Louis


----------



## gibosi

acapella11 said:


> Hi Gibosi, thank you for the quick response and your suggestions.  Yeah, Sylvanias sound dynamic yet detailed with this lovely 6SN7 space perception.
> Sorry, if I made myself not clear with respect to the 5687 year numbers: My first tube on its own has the year codes 5643 in dark grey at the getter flash and 5652 in white under the main label, the other has 5609 in dark grey at the getter flash and but main label has almost completely disappeared.
> 
> Edit: How are your Amperex 6463 tubes coming along?


 
  
 The etched 5643 is likely the date of manufacture and 5652 would be date the tube was silk-screened and packed. It would appear that the other tube was manufactured in 5609, so still quite close in time, and if the construction appears to be the same, likely identical.
  
 I am still burning the GE 6463 in. Once done, and when I can find some time, will try to discern the differences between the Telefunken, Philips and GE. In casual listening, the GE actually sounds pretty good. Vocals bring back memories of the GE 6AU6. One comment I read about the GE is that it is often microphonic, but this is not the case with the two GEs I have. In fact it is the Telefunken that is slightly microphonic, but only when I tap on the amp. I don't hear any extraneous sounds when I tap on the desk, so not a problem.


----------



## gibosi

buldogge said:


> Any comment on later Sylvania 6SNTGTBs?
> 
> They look similar to earlier ones...but...the "chrome dome" is smaller, for sure.
> 
> ...


 
  
 For $7 you can't go wrong! 
  
 When purchasing 6SN7, I try to stick to the 1940's and very early 1950's, as I think they sound slightly better. So if you really like these GTBs, you might want to try some earlier ones later.


----------



## buldogge

The Tung Sols appear to be '49s, so it should make for a decent contrast.
  
 -Mark
  
 Quote:


gibosi said:


> For $7 you can't go wrong!
> 
> When purchasing 6SN7, I try to stick to the 1940's and very early 1950's, as I think they sound slightly better. So if you really like these GTBs, you might want to try some earlier ones later.


----------



## TrollDragon

Just a tip Mark.
  
 If you type after the quoted text then the first bit of your answer will appear in the list of new messages in peoples subscribed lists. If you type before the quoted text your post shows up as *(no title)* in the list.


----------



## GravitySmacked

Total noob here when it comes to tubes. I would appreciate opinions on these:

http://www.ebay.co.uk/itm/251789963059?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

and whether they're a decent upgrade from the standard Little Dot 1+ tubes? 

I listen to pretty most music genres but I probably favour classical and electronic at a push.

Thanks in advance.


----------



## gibosi

gravitysmacked said:


> Total noob here when it comes to tubes. I would appreciate opinions on these:
> 
> http://www.ebay.co.uk/itm/251789963059?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT
> 
> ...


 
  
 I am not familiar with the Svetlana version of this tube, but the Voskhod is a favorite. However, I believe the Ei (Yugoslavia) 6HM5 is significantly better
  
 From here:
  
 http://www.ebay.com/itm/251611916081?
  
 or here:
  
 http://www.ebay.com/itm/6HM5-6HA5-EC900-export-quality-audio-triode-tube-NOS-FREE-SHIPPING-/300879467071?


----------



## GravitySmacked

Thanks for your reply gibosi; I'll take a good look at those links.

I've also been looking at these, which may well be to my taste, after reading the guide at the beginning of the thread:

http://www.ebay.co.uk/itm/M8100-CV4010-5654-MULLARD-VINTAGE-MATCHED-PAIR-VALVE-TUBES-SQUARE-GETTER-/261733284625?pt=UK_Sound_Vision_Valves_Vacuum_Tubes&hash=item3cf084fb11

Is there anyway of telling whether the advertised tubes are indeed matching pairs and from the dates advertised without actually buying them?

Many thanks


----------



## buldogge

Personally, I would skip the EF95 family, other than the 6HM5/6HA5/6HQ5...IMHO.
  
 If you like the "Mullard sound", have a look at EF91/8083 or EF92/8161 (or even CV131).
  
 I would +1 what gibosi said though...grab some Yugo 6HM5s or maybe try these (I like them a lot):
  
 http://www.ebay.com/itm/VACUUM-TUBE-6HQ5-GE-NOS-6HQ5-/370193284113?pt=LH_DefaultDomain_0&hash=item56313d3c11
  
 Also, there is no need for "matched tubes" on the Little Dots...As long as you are using same make/type, you should be GTG.
  
 -Mark in St. Louis
  
  
 Quote:


gravitysmacked said:


> Thanks for your reply gibosi; I'll take a good look at those links.
> 
> I've also been looking at these, which may well be to my taste, after reading the guide at the beginning of the thread:
> 
> ...


----------



## buldogge

I've been rolling these Mullard 8083s tonight...Probably up there with the GE 6HQ5s, for me, so far.  They deliver a little less on the bottom end...but...they are very revealing..._very_ smooth.
  
 http://www.ebay.com/itm/2-x-ROHREN-MULLARD-M8083-NEU-OVP-EF91-/251206910290?pt=Röhren&hash=item3a7d194152
  
 -Mark


----------



## WilliamLeonhart

Emailed LD (gmail) about the buzz and hums on my I+ since Saturday, still no reply yet  Perhaps I need to register on their own forum


----------



## Acapella11

Decided to remove the metal shields from my C3GS tubes. Not much of a glow, as expected, but looks _so_ much better...


----------



## hypnos1

acapella11 said:


> Decided to remove the metal shields from my C3GS tubes. Not much of a glow, as expected, but looks _so_ much better...


 
  
 Well done A11...sure DO look better (IMHO)!....your MKIVSE is getting there, lol! 
	

	
	
		
		

		
		
	


	




.


----------



## gibosi

acapella11 said:


> Decided to remove the metal shields from my C3GS tubes. Not much of a glow, as expected, but looks _so_ much better...


 
  
 Better?  Really? I don't think it looks nearly as good as mine! lol.


----------



## Acapella11

gibosi said:


> Better?  Really? I don't think it looks nearly as good as mine! lol.


----------



## MIKELAP

Nic Rhodes hows the MK9 coming along any comparaisons or comments. Thanks.


----------



## buldogge

Hey Guys...I received one of my Tung Sol (nee Rad Tel) Mouse Ears 6SN7GTs today.  I was just wondering how they came to have zero getter flash/clear glass???
  
 I won't have a chance to run it for awhile...still waiting on the 2nd one and the sockets from China...but...it tests good (84) on my simple Pacific tube tester (assuming the numbers from it are legit!)...with no shorts, and good gas reading.  The black body has no markings printed on it, and the glass only has the 6SN7 over GT from what I can see.
  
 -Mark


----------



## MIKELAP

buldogge said:


> Hey Guys...I received one of my Tung Sol (nee Rad Tel) Mouse Ears 6SN7GTs today.  I was just wondering how they came to have zero getter flash/clear glass???
> 
> I won't have a chance to run it for awhile...still waiting on the 2nd one and the sockets from China...but...it tests good (84) on my simple Pacific tube tester (assuming the numbers from it are legit!)...with no shorts, and good gas reading.  The black body has no markings printed on it, and the glass only has the 6SN7 over GT from what I can see.
> 
> -Mark


----------



## gibosi

buldogge said:


> Hey Guys...I received one of my Tung Sol (nee Rad Tel) Mouse Ears 6SN7GTs today.  I was just wondering how they came to have zero getter flash/clear glass???


 
  
 Getter flash ranges from shiny chrome to black to almost invisible. If the tube develops an air leak, it will turn a chalky white. Mouse ears tend to have an almost invisible flash. Have no idea why, but it is normal.


----------



## buldogge

Crappy low light photo...only place I have to plug it in is the tester socket...


----------



## jaywillin

mikelap said:


> Nic Rhodes hows the MK9 coming along any comparaisons or comments. Thanks.


 
 very interested as well, i almost bought one of these, but went mk iii for now, but i may have a mk 9 yet


----------



## MIKELAP

buldogge said:


> Crappy low light photo...only place I have to plug it in is the tester socket...


 
                                                                                                                    
   This one is a Tung Sol looks similar to yours


----------



## buldogge

^^^Every "mouse ear" ,I have seen photos of, seems to have been made in 1952.  The other tube I ordered (marked Admiral) is a '52 as well.
  
 Mike...Is that your pic?  How do you find the sound/presentation??
  
 -Mark


----------



## MIKELAP

buldogge said:


> ^^^Every "mouse ear" ,I have seen photos of, seems to have been made in 1952.  The other tube I ordered (marked Admiral) is a '52 as well.
> 
> Mike...Is that your pic?  How do you find the sound/presentation??
> 
> -Mark


 
 Yes it is, i would have to listen to them  again my audio memory is very short lol .


----------



## gibosi

Had some time this evening to compare the three 6463 - GE (relabeled by Sylvania), Philips (Heerlen) and Telefunken (Ulms).
  


Spoiler: GE






  


Spoiler: Amperex and Telefunken






  
 Interestingly, I found the GE and Philips were quite similar. Both have a rather lush midrange, but the Philips has a bit more upper bass/lower midrange warmth whereas the GE is a bit livelier with more air. While listening to these tubes, I thought I could be happy with either one.  However, when I added the Telefunken to the mix, I changed my mind. With an LD1+ running a MUSES02 op amp and listening through Senns 700s, the Telefunken is better, to my ears.
  
 I believe the lushness of the GE and Philips masks too much detail. Vocals on theTelefunken on the other hand seem cleaner, while still having good warmth and body, very similar to my reference 1975 Reflektor 6N23P. And as a result this tube has excellent transparency and detail. One of the real strengths of the 700s is imaging, and when paired with a tube as transparent as the Telefunken, I can easily pick out all the vocalists and instruments, from front to back and side to side.
  
 Highly recommended.


----------



## Jolfr

Hey guys,
 I have a couple questions about tube rolling. I just got my first amp (Little Dot Mk III, for my HD650's) and have heard that tube rolling can really help an amp.
 How much does it help the amp in all reality? How much would I need to spend on tubes to make a noticeable/good difference? (I would prefer to not spend too much)
  
 As far as the LD Mk III I see that it can take different kinds of tubes. I can't find anywhere what the difference between a 5654 tube and a 5725 tube is. And what's the difference between a 6H6PI, a 6H6n and a 6H6nN?
  
  
 Thank you very much to anyone who can help me out with this!


----------



## WilliamLeonhart

gibosi said:


> Better?  Really? I don't think it looks nearly as good as mine! lol.


 
 What are those wires for? And if I'm not wrong you're using adapters below the tubes?


----------



## MIKELAP

jolfr said:


> Hey guys,
> I have a couple questions about tube rolling. I just got my first amp (Little Dot Mk III, for my HD650's) and have heard that tube rolling can really help an amp.
> How much does it help the amp in all reality? How much would I need to spend on tubes to make a noticeable/good difference? (I would prefer to not spend too much)
> 
> ...


 
 Take a look at these power tube comparaison page 201 post # 3007


----------



## MIKELAP




----------



## gibosi

williamleonhart said:


> What are those wires for? And if I'm not wrong you're using adapters below the tubes?


 
  
 I have set my LD1+ up to run double triodes as drivers using an external 9-pin breadboard socket, an external DC heater circuit and two 7-pin Vector test sockets. When I wish to run C3gs, I simply make sure there is no tube in the external 9-pin socket, and then plug the C3gs directly into the test sockets. 
  
 Here pictured with the Telefunken 6463 mentioned just above.


----------



## Nic Rhodes

mikelap said:


> Nic Rhodes hows the MK9 coming along any comparaisons or comments. Thanks.


 
  
 Well spent some time with the new Little Dot Mk9 now, thoughts so far:
  
 Well I'll cut straight to one conclusion, this is a nice upgrade to a LD III, IV or IVse with rolled tubes (say C3Gs and 5687 / 6SN7GT premium combinations). So yes it is a far better amp than basic or rolled baby LD and one that I am very fond of now.
  
 So a little more detail about the LD Mk9:
  
 The amplifier has the same form factor as the a LD III, IV or IVse amps but uses a different circuit and different tubes. The amp has perhaps more in common with the MkVI+ power house but a half of it. It has a single driver tube which is 6SL7GT and two output tubes of 6080. Both of these tubes are common and cheap, this is something I think is very important as we have all seen what has happened to the cost of some tubes recently. There are also many other similar tubes that could be rolled.
  
 The 6SL7GT is actually a Chinese 6N9P. The quality of this tube was average and not to my taste at all, however there are lot’s of alternative you can try.
  
 Russian 6N9S / 6H9C are  widely available and come in metal or plastic bases. Most seem to prefer the metal based ones but not really what interests me. I prefer the European and US examples.
  
 The 6SL7GT was released during the war years (1942?) and has been made in huge numbers ever since. The early ones were often made with round plates and were also marked VT-229.  These are not expensive at all (and this amp has the advantage of using only one!). In terms of cost they are much less than the sister tube 6SN7GT. The early example are still plentiful on the ‘bay’ so people should have no problem getting stocks. There are also some ruggedized examples. These are labelled 6SL7WGT or 6113. Then there is the ‘RCA’ red based version 5691 which is a super ruggedized ‘long life’ version. This was made in a black based version well into the 1980s by PhilipECG (Sylvania) and these late example aren’t bad at all and really well made. There is also a premium compatible version called 6SU7GT or  6188 which is my favourite. 1940s examples from Tung-sol are excellent  I am a fan of all of these premium and ruggedized examples (none carry the price premium of 6SN7GT does now) but tbh there are many great examples from many great makes (usual names), especially from the 1950s and 1940s.
  
 The Europeans made the ECC35 which is similar to the CV569 and close enough to be in the 6SL7GT family. The other military number to look out for is the CV1985 (Brown and Black based examples) and many examples were marked as Brimar (although actually made by STC, either at their Footscray plant, look for KB / FB marking or KB/FE for STC, Oldway ). I like these. Quality tubes but generally a little more money (still affordable however). For those wanting to use with adapters then there is 6C8G with a top cap (pre dated the 6SLGT) and the Loctal 7F7 (mostly Sylvania made). Both nice rubes. In fact there is a real wealth of quality tubes out there, they are well priced, quality is high and you only need one for this amp. It is a win everywhere.
  
 The 6080 is an industrial triode and this amp uses two French Thomson CSF (very decent). This is reasonable powerful output tubes and is far easier to drive it properly than say the beefier 300b. It is ideally suited to headphone amplifiers because of it’s size and can be used in a number of configurations. Here the Little Dot Mk9 is used in SEPP (single ended push pull) OCL (output capacitor-less) design and this design means you can also use it to drive a power amplifier as well as headphones (not something I recommend with all power amps in others members of the LD range). This in itself is a departure from the LD III, IV or IVse amps and much closer to the VI+. What this means is that you will get same power into 32 ohms as you will 600 ohm phones (as opposed to the Output Transformer less Designs OTL which are best at driving >300 ohm phones despite marketing claims saying otherwise… ).
  
 If the 6080 is too dull and squat to look at, then pop in 6AS7G tubes. Often better performance again also and prettier shape but identical electrical characteristics. Both of these tubes are still cheap and plentiful (if you don’t want the best GEC models). The Russian 6N5S / 6N13S examples (of 6AS7Gs) are plentiful and cheap and have excellent performance (I like the oldest ones best). £12.50 will even get you NOS 6080 Mullard in crisp new boxes….and remember this is a big tube (Langrex by the way). Good 6080 tubes by Tung-sol, GE 5*, RCA Command, Bendix (graphite), Mullard, Thomson CSF and GEC, good 6AS7G tubes by Tung-sol, RCA, Chatham and GEC. Basically loads of good options out there including many not mentioned.
  
 So this amp runs cheap tubes, has only 1x 6SL7GT and 2x 6080 / 6AS7Gs and will drive most things. So how does it perform?
  
 Well considering this amp has been around for a few years now, I am amazed that more has not been written about it. I found one reference to it humming on the internet. My example is dead quiet and I mean really quiet. It does not have the romance of the OTL driving 600 ohm headphones (few do) but has a wonderful even nature. Unlike most of my amplifiers which drive one type of phone (big OTL fan), this amp has a decent stab at most of them. It won’t drive an HE6 but little does (properly) and LD have their VI+ for that anyway. So it is a great all-rounder, and when properly loaded with the quality tubes  it makes great sounds without being a power house. In fact my AKG 240DFs never have sounded better. At it’s price, I think it makes great value and I really am struck by how few people know about it. This certainly does not make any sense given it’s quality.
  
 I now see this as well above the level of the LD III, IV or IVse (even fully rolled / adapters galore) and more as a baby VI+ (though I haven’t heard this yet). There is just way too much similarity in how they are designed to disniss the similarity. The big brother is now firmly on my wants list. List from David Z is $459 for the Little Dot Mk9 which puts it into an interesting area that is sparsely populated for affordable valve amp that are cheap to run. Perhaps the obvious competition will be the Elise but that is an OTL, used 2x of the more expensive 6SN7GTs and same output tubes. Both look very interesting propositions and I may be the first to own both  I don’t see it as one being better than the other  but more similar priced amps aiming at different markets but similar tubes / form factor. It will make an interesting shoot off however.
  
 All told, one fine performing amp, keenly priced that is cheap to run.


----------



## MIKELAP

nic rhodes said:


> mikelap said:
> 
> 
> > Nic Rhodes hows the MK9 coming along any comparaisons or comments. Thanks.
> ...


 
 To my knowledge its the first time i ear someone comment on the MK9 ,nice read thanks Nic. Last time i looked i didnt find anything on the Littledot website


----------



## mordy

Hi Jolfr,
  
 Welcome to the forum!
  
 Here is a recipe for sound that it is at least three levels better than stock for the MKIII for a small cost:
  
 A pair of Ei 6HM5 tubes for drivers.
  
 A pair of inexpensive Sylvania 6SN7 tubes for power tubes. In addition you need a pair of socket adapters to use the octal tubes as well as a pair of socket extenders since the adapters are too wide to fit into the socket opening for the power tubes.
  
 Everything is plug and play.
  
 So there you are - what it took us several years to figure out you can benefit from right away - no need to wade through all the possibilities that were explored in a couple of hundred posts....


----------



## jaywillin

mordy said:


> Hi Jolfr,
> 
> Welcome to the forum!
> 
> ...


 
  
 would these be available on ebay or another supplier, or would they need to be made ? , i've got some yugo 6hm5's already


----------



## stvn758

Someone please tell me there's an easy way to switch the jumpers so I can finally listen to my Yugoslav tubes. Pulled both the little bastards out but no matter which tweezers I use cannot get them back in. Looks like they upgraded the new MK3 to something a little easier.
  
 Is there a helpful guide on here to pulling apart the amp without destroying it so I'm not poking through a hole in the bottom for hours on end. I unscrewed the rear and top screws but only some of the rear end guts came out, the odd looking black ones on the front panel gave me pause for thought - do they require a special bit or are they just black washers?
  
 What happens if I play the amp without the jumpers in, nothing untoward I read, only need them for the other family of tubes.
  
 Could have made the whole on the bottom a bit bigger, maybe a nice flap you could unclip, nothing too grand.
  
  
 Managed it in the end, lots of shaking the thing about to get the jumper back out. Bloody newbies eh!!
  
 Guess it would help if I actually had the right set of tubes, the Yugoslav ones I have are the same as the previous ones and don't need the jumpers changed - hence the silence. What was I thinking, obviously wasn't.


----------



## gibosi

Received an US-made Amperex E182CC/7119 today.
  
 US on the left and Heerlen on the right.
  

  
 I have been searching for a US-made E182CC for several months now. Frankly, I find most Heerlen-made tubes to be a bit too lush for my taste. This is likely somewhat due to the fact that my HD700s are pretty bright, as many others love, love, love the Heerlen sound. 
  
 Since I prefer US-made E88CC over the Heerlen-made tubes, I thought it was worth trying a US-made E182CC. However, US-made E182CC appear to be quite rare. Further most I have seen were manufactured in the 1970s and into the 1980s. I have yet to see one manufactured in the early to mid 1960s, which is my preference. In the end, this 1972 tube (ID8 *2F) was the earliest I could find. For comparison purposes, the Heerlen tube on the right was manufactured in 1962 (ID2 ⊿2A1). Interestingly I cannot detect any construction differences in these tubes even though manufactured 10 years apart in different factories.
  
 I am pleased to report this tube lights up and plays. Will have more to say after burn in.


----------



## mordy

Hi jaywillin,
  
 Here is a link to a pair of socket extenders:
  
 http://www.ebay.com/itm/2PCS-9-PIN-TUBE-SOCKET-SAVER-FOR-12AX7-12AU7-ECC82-ECC83-tube-amp-audio-DIY-part-/161584664637?pt=LH_DefaultDomain_0&hash=item259f32503d
  
 Here is a link to the octal to 9pin adapters:
  
 http://www.ebay.com/itm/191082280257?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT
  
 $4.29 + $18.31x2 - $2 combined shipping = $38.91
  
 Here is a starter pair of Sylvania 6SN7 tubes with the bidding starting on $7. (There are a lots of choices - this is just one example)
 http://www.ebay.com/itm/Pair-6SN7-GTA-Sylvania-Tubes-Used-/141564857510?pt=LH_DefaultDomain_0&hash=item20f5ec4ca6


----------



## jaywillin

mordy said:


> Hi jaywillin,
> 
> Here is a link to a pair of socket extenders:
> 
> ...


 
 thanks, the octal the 9-pin adapter was the the main think i was having trouble finding


----------



## MIKELAP

stvn758 said:


> Someone please tell me there's an easy way to switch the jumpers so I can finally listen to my Yugoslav tubes. Pulled both the little bastards out but no matter which tweezers I use cannot get them back in. Looks like they upgraded the new MK3 to something a little easier.
> 
> Is there a helpful guide on here to pulling apart the amp without destroying it so I'm not poking through a hole in the bottom for hours on end. I unscrewed the rear and top screws but only some of the rear end guts came out, the odd looking black ones on the front panel gave me pause for thought - do they require a special bit or are they just black washers?
> 
> ...


 
    I use these extended jumpers with a pair of needle nose pliers no more panic attack lol  .mordy made a pair of jumpers with an extension  on them page 220  post #3297 .


----------



## WilliamLeonhart

Where did you buy those extended jumpers?


----------



## MIKELAP

williamleonhart said:


> Where did you buy those extended jumpers?


 
 Check out Ebay


----------



## stvn758

Now that is ingenious.


----------



## WilliamLeonhart

mikelap said:


> Check out Ebay


 
 Sometimes I forgot the obvious (___-_____!)


----------



## stvn758

These 6HM5 EC900 EI Yugoslavia tubes I was recommended on here are quite feisty, aren't they. Like someone has turned the gain setting up. Always amazed when you swear you can hear things you never heard before on a CD with a new bit of kit added - tried my go to slice of audio heaven ( ) and dauðalogn by Sigur Ros for testing purposes, not sure if it's the placebo effect but wow!
  
 They are very precise and detailed once you get over the initial 'boom', my gain setting is at it 4 at the moment, not sure if dropping it all the way down will add something else to the mix.
  
 What's the burn in time on these, not the hundred hours for the Matched Voskhod Gold pins Gold grid 6ZH1P-EV 6AK5 EF95 403B 5654 6J1 1975 NIB I just took out.


----------



## buldogge

I don't have the Yugo 6HM5s, but I do have equivalent GE 6HQ5s and I have found the same thing.  I really like this tube family!  
  
 Having said that, for the past few days, I have been rolling Mullard M8083s (70's, blue glass) and I think I like the slightly less boomy gain...seems like maybe it is a little more revealing...a little smoother.
  
 Need to do a quick back-to-back...have to deal with the jumpers of course.
  
 -Mark in St. Louis
  
 Quote:


stvn758 said:


> These 6HM5 EC900 EI Yugoslavia tubes I was recommended on here are quite feisty, aren't they. Like someone has turned the gain setting up. Always amazed when you swear you can hear things you never heard before on a CD with a new bit of kit added - tried my go to slice of audio heaven ( ) and dauðalogn by Sigur Ros for testing purposes, not sure if it's the placebo effect but wow!
> 
> They are very precise and detailed once you get over the initial 'boom', my gain setting is at it 4 at the moment, not sure if dropping it all the way down will add something else to the mix.
> 
> What's the burn in time on these, not the hundred hours for the Matched Voskhod Gold pins Gold grid 6ZH1P-EV 6AK5 EF95 403B 5654 6J1 1975 NIB I just took out.


----------



## buldogge

Do you guys ever buy tube lots off eBay that are untested?
  
 Obviously it's a gamble...but I'm thinking $10 for 3-4-or-5 tubes might be worth a play...???
  
 Also, for you guys that know something about tube testers...
  
 I recently bought a couple TS Mouse Ears 6SN7GTs off eBay...2 different sellers.  I also bought a pair of Sylvania GTBs.  I have an old Pacific 'Dial Junior' tester...it uses a simple 0-100 meter scale.  I tested all the tubes I bought, against the sellers numbers.  Their numbers are always xx/yy...My *number* (amp setting)* *doesn't necessarily match either of their numbers...but...4 of the 5 tested as good, and were in a similar range to these sellers 2nd number.  One of the TSs tested only 59 on my tester ("replace").  
  
 Of course, I can't real world test it yet, because I don't have the sockets to finish my adaptors.
  
 Thoughts???
  
 TIA
 -Mark


----------



## lagigia

Hello!
 I have LD MkIII. I am testing Mullard M8100 and Voshkod 6ZH1P-EV with power tubes Electro-Harmonix 6H30Pi Gold.
  
 I can decide which one is better, M8100 and 6ZH1P-EV sounds really similar to me.
  
 Thoughts?


----------



## mordy

Hi stvn 758,
  
 For most tubes a burn in time of 30-40 hours should be enough. Some hi-fi manufacturers of high end equipment routinely burn in tubes for 48 hours.


----------



## mordy

Hi buldogge,
  
 I have bought a number of inexpensive lots on Ebay with generally good results. Once you want to try a new tube family, a bunch of different used ones is a lot of fun to try out. In my experience it is rare to get non working tubes.
  
 A tube that doesn't measure new may still have a lot of life in it. IMHO all you may need to do is to turn up the volume a little more. Once you find what you like, you may want to buy NOS tubes.
  
 As far as I know, different tube testers give very different values and the measurements are often not directly comparable to each other. There seems to be much debate about the accuracy as well. The best and most accurate testers are very expensive and need to be professionally calibrated as well.
  
 Let your ears be the judge.....


----------



## mordy

Hi lagigia,
  
 Try one each in each socket and see if you can hear the difference in each channel on a monophonic recording. Both tubes are good, but there are better choices, such as the Ei 6HM5.


----------



## buldogge

Thanx Mordy...I guess I'll just have to wait and see how it performs.  I was wondering whether it would create a channel imbalance, since I will be using (2)...
  
 -Mark
  
 Quote:


mordy said:


> Hi buldogge,
> 
> I have bought a number of inexpensive lots on Ebay with generally good results. Once you want to try a new tube family, a bunch of different used ones is a lot of fun to try out. In my experience it is rare to get non working tubes.
> 
> ...


----------



## lagigia

Hi Mordy,
 something better?! Oh boy, I trusted the reviews on the first page and I bought the top EF95 model. Was I wrong?
  
 Anyway, I'll do as you suggested and I'll look for a quality mono source... something on youtube?


----------



## gibosi

buldogge said:


> Do you guys ever buy tube lots off eBay that are untested?
> 
> Obviously it's a gamble...but I'm thinking $10 for 3-4-or-5 tubes might be worth a play...???


 
  
 I agree with Mordy on this. If the price is right, that is cheap, I often buy bunches of cheap tubes off eBay. It is very rare that I get a dud and very importantly, it allows me to 'taste" the flavor of tubes I have no experience with on the cheap. And when I find tubes I really like, then I am more willing to spend a bit more to get tubes that test NOS or near NOS.


----------



## Jolfr

lagigia said:


> Hi Mordy,
> something better?! Oh boy, I trusted the reviews on the first page and I bought the top EF95 model. Was I wrong?
> 
> Anyway, I'll do as you suggested and I'll look for a quality mono source... something on youtube?


 
 I would definitely choose FLAC to listen to, especially if you're looking for small differences. Then use Foobar2000 to play the tracks in mono.


----------



## Mojo777

mordy said:


> Hi jaywillin,
> 
> Here is a link to a pair of socket extenders:
> 
> ...


 
*thanks a bunch, i'm new to this*
  
*looks like the last piece of the puzzle is a pair of EI 6HM5, where do you source those?*


----------



## adtrance

mojo777 said:


> *thanks a bunch, i'm new to this*
> 
> *looks like the last piece of the puzzle is a pair of EI 6HM5, where do you source those?*


 
 Tall bottle IE 6HM5:  http://www.ebay.com/itm/6HM5-6HA5-EC900-export-quality-audio-triode-tube-NOS-FREE-SHIPPING-/300879467071


----------



## MIKELAP

mojo777 said:


> mordy said:
> 
> 
> > Hi jaywillin,
> ...


 
 Or here you want the tall bottles       http://www.ebay.com/itm/251611916081?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT


----------



## stvn758

mordy said:


> Hi stvn 758,
> 
> For most tubes a burn in time of 30-40 hours should be enough. Some hi-fi manufacturers of high end equipment routinely burn in tubes for 48 hours.


 

 Thanks, these Yugoslav ones certainly gave me a jump.


----------



## lagigia

jolfr said:


> I would definitely choose FLAC to listen to, especially if you're looking for small differences. Then use Foobar2000 to play the tracks in mono.


 
  
 Thanks mate!


----------



## Acapella11

lagigia said:


> Thanks mate!


 
  
 If you want to use an alternative good player in Stereo, Musicbee is excellent, and switch to playback via WASAPI, that circumvents sound altering influences from Windows.


----------



## Acapella11

gibosi said:


> Had some time this evening to compare the three 6463 - GE (relabeled by Sylvania), Philips (Heerlen) and Telefunken (Ulms).
> 
> Interestingly, I found the GE and Philips were quite similar. Both have a rather lush midrange, but the Philips has a bit more upper bass/lower midrange warmth whereas the GE is a bit livelier with more air. While listening to these tubes, I thought I could be happy with either one.  However, when I added the Telefunken to the mix, I changed my mind. With an LD1+ running a MUSES02 op amp and listening through Senns 700s, the Telefunken is better, to my ears.
> 
> ...


 
  
 Almost missed that one. Thanks for sharing!


----------



## Acapella11

nic rhodes said:


> Well spent some time with the new Little Dot Mk9 now, thoughts so far:
> 
> Well I'll cut straight to one conclusion, this is a nice upgrade to a LD III, IV or IVse with rolled tubes (say C3Gs and 5687 / 6SN7GT premium combinations). So yes it is a far better amp than basic or rolled baby LD and one that I am very fond of now.
> 
> ...


 
  
 Seems, I didn't read page 600 at all! This is amazing information on an amp hardly anyone looked at. I would suggest to start your own thread to enlighten more people.
  
 Edit: Could you quantify how much much of a step up this is from the best LD IV configuration you know and where the differences are, e.g. in terms of transparency, frequency extension etc.?


----------



## Mojo777

My LD MKiii just arrived. No hum! and warming up for the first time right now.


----------



## Acapella11

mojo777 said:


> My LD MKiii just arrived. No hum! and warming up for the first time right now.


 
  
 Very nice pic and great gear. Enjoy your new amp!
 How do you feel of the combination with the LCD 2? They are theoretically not matching that well with OTL amps.


----------



## Mojo777

Thanks. I have an X which should not pair well but on medium gain 5 I think the synergy is very good so far. Letting it warm up for the past couple of hours really improved the sound. I really like the wide soundstage and the treble improved a lot from when I first turned it on. Nice! Looks like I will be ordering the upgraded tubes mentioned on page 602. Definitely different than the OPPO but in a good way.


----------



## bobbyblack

I discovered 2 weeks ago Musicbee and is amazing,I use both(foobar2000),with Asio.


----------



## MIKELAP

bobbyblack said:


> I discovered 2 weeks ago Musicbee and is amazing,I use both(foobar2000),with Asio.


 
 Do you find theres a difference in sound between the 2 ive had Musicbee for  3 1/2 years now and its great, i have around 22000 tunes in there and its still fast .With my Burson's Dac i can use Wasapi only  when i use my  Asus Essence STX soundcard i was using Asio.all in all i love that player.


----------



## bobbyblack

I use Asio with Peachtree Dac It X because ppl. say are better than Wasapi(never tried with this dac,but i'l do soon) and on Foobar i like to try different themes from Deviantart,is very customizable!
I dont did it difference between players until now,i use 95% of time Musicbee and i like it sooooo much(themes are nice to),no lag or anything ,is quite light.


----------



## Acapella11

For me, WASAPI is superior to ASIO with Musicbee, but that is using ASIO4ALL and not hardware specific ASIO.
I my ears, Musibee sounds richer, more dynamic than Foobar.


----------



## buldogge

Hey Guys...I've got a slightly OT MK III question...
  
 For "testing" purposes could I run my Senn HD650s from an RCAs to stereo jack cord off the pre-amp outputs?
  
 Bored while waiting for the loctal and 8 pin sockets for my adaptor plate to arrive from China...
  
 TIA
 -Mark


----------



## jaywillin

ok, i'm a little confused(not the first time) lol
 regarding the power tubes on the mkiii, i've got a pair of 6sn7's with the adapter's, and extenders coming in, 
 but are there any drop in replacements ? 
 i've been trying to do some research, reading, and i'm confused as to whether the ecc99,e182cc, 7119 need adapters, i think what's throwing my off is the 5687 , 
 does it need the adapter and not the others ?


----------



## TrollDragon

buldogge said:


> Hey Guys...I've got a slightly OT MK III question...
> 
> For "testing" purposes could I run my Senn HD650s from an RCAs to stereo jack cord off the pre-amp outputs?
> 
> ...


The Pre-Out and the Headphone Jack are wired in parallel on the LD MKIII and MKIV's. So yes you can.


----------



## buldogge

Thanx TD.
  
 -Mark


----------



## mordy

HI JAYWILLIN,
  
 The 5687 has 9 pins, but the wiring is different than the stock power tubes in the MKIII, so it will need an adapter with the correct pinout. Regarding the other tubes, I assume the situation is similar. If you look up Radiomuseum on Google for each of the tubes, there will be a picture there for each tube with the wiring/pinout.
  
 http://www.radiomuseum.org/tubes/tube_5687.html
  
 Better yet, ask Gibosi, who is our resident expert on these matters.


----------



## jaywillin

mordy said:


> HI JAYWILLIN,
> 
> The 5687 has 9 pins, but the wiring is different than the stock power tubes in the MKIII, so it will need an adapter with the correct pinout. Regarding the other tubes, I assume the situation is similar. If you look up Radiomuseum on Google for each of the tubes, there will be a picture there for each tube with the wiring/pinout.
> 
> ...


 
 yeah, i was gathering the wiring wasn't the same, but then i'd read something that would say they were equivalent , thanks for the link


----------



## gibosi

jaywillin said:


> regarding the power tubes on the mkiii, i've got a pair of 6sn7's with the adapter's, and extenders coming in,
> but are there any drop in replacements ?
> i've been trying to do some research, reading, and i'm confused as to whether the ecc99,e182cc, 7119 need adapters, i think what's throwing my off is the 5687 ,
> does it need the adapter and not the others ?


 
  
 I am not aware of any drop in replacements...... Of all the tubes with that pin-out, only the standard suggested Russian tubes have enough "power". 
  
 The 5687, 7044, E182CC/7119 all have the same pin-out. And yes, an adapter is needed to run any of these as a power tube in the LD. An adapter with 5687 on top and 6N6, ECC88, 6CG7 on the bottom. something like this:
  
 http://www.ebay.com/itm/1piece-Gold-plated-5687-TOP-TO-6N6-6N11-ECC88-6922-tube-converter-adapter-/191395667769?
  
 The ECC99 is a current production tube with the same pinout as a 12AU7 and it too will require an adapter with 12AU7 on top and 6N6, ECC88, 6CG7 on the bottom, something like this:
  
 http://www.ebay.com/itm/1Piece-Gold-plated-12AU7-ECC82-adapter-top-to-6CG7-6FQ7tube-converter-adapter-/191489172267?


----------



## jaywillin

gibosi said:


> I am not aware of any drop in replacements...... Of all the tubes with that pin-out, only the standard suggested Russian tubes have enough "power".
> 
> The 5687, 7044, E182CC/7119 all have the same pin-out. And yes, an adapter is needed to run any of these as a power tube in the LD. An adapter with 5687 on top and 6N6, ECC88, 6CG7 on the bottom. something like this:
> 
> ...


 
 thank you gibosi ! you're the man
 any recommendations, ? i know when i had my mad ear+ hd, rolling power tubes didn't give much , if any improvement


----------



## jaywillin

I should say "the man"


----------



## gibosi

jaywillin said:


> any recommendations, ? i know when i had my mad ear+ hd, rolling power tubes didn't give much , if any improvement


 
  
 I have a 1+, which uses an op amp instead of power tubes, so I am afraid I am not in a position to make any recommendations. lol. 
  
 From the postings of others, Tung-Sol and Sylvania 5687 have gotten good reviews. But unfortunately, no one has commented on the E182CC or the 7044. The vast majority of E182CC were manufactured in Heerlen, Holland, so if you like the "Holland" sound, a pair of these might be worth a try. The 7044 was manufactured only in the US.
  
 The ECC99 is a modern tube, manufactured in Russia, I believe. I have no experience with it and I don't know if anyone has tried it in an LD. On the other hand, it is quite cheap and might be worth a try.
  
 https://www.tubesandmore.com/products/T-ECC99-JJ


----------



## jaywillin

gibosi said:


> I have a 1+, which uses an op amp instead of power tubes, so I am afraid I am not in a position to make any recommendations. lol.
> 
> From the postings of others, Tung-Sol and Sylvania 5687 have gotten good reviews. But unfortunately, no one has commented on the E182CC or the 7044. The vast majority of E182CC were manufactured in Heerlen, Holland, so if you like the "Holland" sound, a pair of these might be worth a try. The 7044 was manufactured only in the US.
> 
> ...


 
 thanks again, 
 i think i'll just get a good assortment and do a little experimenting


----------



## adtrance

I too ordered an assortment of tubes and a MUSES02 op-amp to tinker with. 
  
 I will say that the LD 1+ sound much better today than they did out of the box.


----------



## gibosi

adtrance said:


> I too ordered an assortment of tubes and a MUSES02 op-amp to tinker with.
> 
> I will say that the LD 1+ sound much better today than they did out of the box.


 
  
 Which tubes did you order?


----------



## gibosi

[fixed]


----------



## Acapella11

gibosi said:


> We need some more feedback on alternative power tubes, so please let us know which ones you get and how they sound.


 
  
 It is a I+


----------



## adtrance

gibosi said:


> Which tubes did you order?


 

 Oh just the usual suspects - Voskhod 6ZH1P-EV (two sets:  1973 pair and 1987 pair), Yugoslavia 6HM5, GE JAN 5654W.


----------



## adtrance

acapella11 said:


> It is a I+


 

 Yep, just driver tubes on mine.


----------



## gibosi

jaywillin said:


> thanks again,
> i think i'll just get a good assortment and do a little experimenting


 
  
 (Responding to the right person this time.... lol )
  
 We need some more feedback on alternative power tubes, so please let us know which ones you get and how they sound.


----------



## jaywillin

gibosi said:


> (Responding to the right person this time.... lol )
> 
> We need some more feedback on alternative power tubes, so please let us know which ones you get and how they sound.


 
 i kinda had a feeling you were talking to me!  
	

	
	
		
		

		
		
	


	



  
 i'll certainly report back


----------



## d4rkch1ld

Hey guys i would like to hit the 6AS7 train so i would be grateful if some1 could repost, or PM me tutorial how to do it. It's hard to find all the usefull information in this 600 pages. I'm now using 6SN7 as powers and C3Gs as drivers. Also have an little problematic C3G adpters as they sometimes hums. Would using test socket and then routing wires to amp solve my problem? I dont mind messy look. Maybe some1 could open a new thread with this tutorial so people can find it easyer?


----------



## gibosi

d4rkch1ld said:


> Hey guys i would like to hit the 6AS7 train so i would be grateful if some1 could repost, or PM me tutorial how to do it. It's hard to find all the usefull information in this 600 pages. I'm now using 6SN7 as powers and C3Gs as drivers. Also have an little problematic C3G adpters as they sometimes hums. Would using test socket and then routing wires to amp solve my problem? I dont mind messy look. Maybe some1 could open a new thread with this tutorial so people can find it easyer?


 
  
 Mordy and Hypnos1 are the resident experts in using 6AS7s in the LD. You might want to search this thread for their posts mentioning 6AS7.
  
 If you are thinking about using two loctal breadboard sockets with routing wires to 7-pin test sockets, you could install "grid stopper" resisters on all the grids which might help. Check out the following discussion here:
  
 http://www.head-fi.org/t/732875/feliks-audio-6sn7-6as7g-6080-prototype/795#post_11252025
  
 Good luck!


----------



## mordy

Hi d4rkch1ld,
  
 Modding your LD MKIII/IV amp to use 2.5A power tubes will give it a totally new dimension in sound with much more powerful bass and more detail. Here is what you need (in addition to a pair of 6AS7/6080 tubes or equivalent):
  




  
 This is a 9pin socket saver/extender. You can buy a pair for under $5 on Ebay. There is a screw that goes through it with a little recessed nut. Unscrew it, open it up and desolder pins 4 and 5. Then drill a hole in the side of the barrel big enough for 18gauge lamp cord wire. Solder this wire to the sockets #4 and #5 and pull through the wall of the extender.
  
 Now you need a pair of adapters for octal tubes to 9pin 6CG7 adapters. These cost around $30/pair.




 http://www.ebay.com/itm/221065459067?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT
  
  
 Next you need a 15A voltage regulator (costs less than $13 on Ebay).




  
 http://www.ebay.com/itm/231104103029?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT
  
 There is a little set screw of brass that can be turned for the proper voltage for the tubes (6.3V). An inexpensive volt meter/multi tester will help you measure the voltage.
  
 Lastly, you need a 15A power supply. You can buy decent power supplies for PCs on sale for around $30 - look on Newegg for sales. Use the voltage meter to find the 12V connectors.
  
 Connect the socket extenders to the voltage regulator, the voltage regulator to the power supply, and plug it in. The tubes go into the octal extenders, the bottoms of which fit into the 9pin extenders that plug into the power tube sockets in the amp.
  
 Some people worry that the 2.5A tubes will overheat the LD amp. I use two old PC fans to draw away heat from my amp and have not had any problems with this set up over hundreds of hours of listening.
  
 The power tubes do get very hot to the touch in operation, but the amp stays cool to slightly warm with this configuration.
  
 If you need more clarification on how to use the 6AS7/6080 tubes, just ask.
  
 Good luck!


----------



## adtrance

The amount of information and the help given in this thread is truly staggering.
  
 Thank you guys for your contributions!!


----------



## Nic Rhodes

Not problem with feedback on E182CC, many of the regular types here, what do people want tried. Say Mullards from UK, US and Holland?


----------



## NiMo7

adtrance said:


> Oh just the usual suspects - Voskhod 6ZH1P-EV (two sets:  1973 pair and 1987 pair), Yugoslavia 6HM5, GE JAN 5654W.


 

And what do you like the most?


----------



## d4rkch1ld

Thanks alot mordy.
 Are these extenders u were talking about? http://www.ebay.com/itm/2PCS-9-PIN-TUBE-SOCKET-SAVER-FOR-12AX7-12AU7-ECC82-ECC83-tube-amp-audio-DIY-part-/160622385954?pt=LH_DefaultDomain_0&hash=item2565d71b22
 Also any recomendation for starting tubes? Are soviet Svetlana good for start?


----------



## bogdanopolis

Which EF91, 92 or 95 tubes can I use in my Little Dot II Amp? , it is the first model produced in 2005.


----------



## mordy

Hi d4rkch1ld,
  
 Yes, you have the right link for the extenders. Would suggest to get four for just a little more money in case something goes wrong in making them.
  
 For power tubes my favorites are 1960's Sylvania 6080 tubes. These are plentiful and not expensive.


----------



## mordy

Hi adtrance,
  
 Thanks for your comment.
 What makes this thread so great is the helpfulness, honesty and humility of the participants. There is a lot of excellent information here, and everybody tries to help each other.


----------



## adtrance

nimo7 said:


> And what do you like the most?


 

 I don't know!  
	

	
	
		
		

		
			




  
 I've only had my Little Dot 1+ for a few days and from what I understand, it takes a good 40-60 hours before you get to see the real potential of any NOS tubes.  So it might take me a month or two before I can say which one I like the most.  
	

	
	
		
		

		
		
	


	




 
  
 That's why I ordered these tubes - they seem to consistently have the best reviews.


----------



## adtrance

mordy said:


> Hi adtrance,
> 
> Thanks for your comment.
> What makes this thread so great is the helpfulness, honesty and humility of the participants. There is a lot of excellent information here, and everybody tries to help each other.


 

 I've only recently joined this community and I'm looking forward to pitching in.


----------



## gibosi

bogdanopolis said:


> Which EF91, 92 or 95 tubes can I use in my Little Dot II Amp? , it is the first model produced in 2005.


 
  
 Given the age of your amp, I simply do not know....   I suggest that you contact Little Dot directly with this question:
  
 little.tube@gmail.com


----------



## TrollDragon

bogdanopolis said:


> Which EF91, 92 or 95 tubes can I use in my Little Dot II Amp? , it is the first model produced in 2005.


 

 The old LD II takes 1B2 and 4P1S tubes you can't use any EF91,92 or 95's.
 Here is a thread on LD II tubes. -> http://www.head-fi.org/t/164093/tube-swapping-not-working-out-for-my-ldii


----------



## Acapella11

mordy said:


> Hi d4rkch1ld,
> 
> Modding your LD MKIII/IV amp to use 2.5A power tubes will give it a totally new dimension in sound with much more powerful bass and more detail. Here is what you need (in addition to a pair of 6AS7/6080 tubes or equivalent):
> 
> ...


 
  
  
 Thank you for posting this info Mordy. I have included this post in the table on page 585.


----------



## Acapella11

mojo777 said:


> Thanks. I have an X which should not pair well but on medium gain 5 I think the synergy is very good so far. Letting it warm up for the past couple of hours really improved the sound. I really like the wide soundstage and the treble improved a lot from when I first turned it on. Nice! Looks like I will be ordering the upgraded tubes mentioned on page 602. Definitely different than the OPPO but in a good way.


 
  
 Ok, that sounds very promising for using the LCD X with the LD, besides the price point . I have heard it is easier to drive than the 3 or even 2.


----------



## i luvmusic 2

Be very careful using 6AS7G/6080 tubes it could create the MAGIC SMOKE


----------



## mab1376

acapella11 said:


> Ok, that sounds very promising for using the LCD X with the LD, besides the price point . I have heard it is easier to drive than the 3 or even 2.


 
  
 The HE1000 is supposedly also easier to drive with its new nanometer diaphragm.
  
 http://audio-head.com/the-hifiman-he-1000-ces-2015/


----------



## gibosi

nic rhodes said:


> Not problem with feedback on E182CC, many of the regular types here, what do people want tried. Say Mullards from UK, US and Holland?


 
  
 Not sure which post you are responding to... 
  
 What we need is more info on alternatives to the 6N6-type power tubes for the LD II, III and IV.
  
 A number have tried 6SN7s and 5687s with good results. While I have tried E182CC, 7044, 6463, 6350 as drivers, and believe them to be very good, I have not seen any posts about using these as power tubes. Of course, those who have adapters to allow the use of 5687 can also roll E182CC and 7044, so I am hoping that someone will take the plunge.
  
 Unfortunately, I have yet to see an adapter to roll 6463 and 6350 in a 6N6/6GC7/6DJ8 socket. In order to run these as drivers, I am using two adapters, one from 6463 to 6SN7 and then a second 6SN7 to 6N6. Pretty ugly! lol.


----------



## jaywillin

i received my sylvania 6sn7's today, waiting on the adapters
 also ordered 
*Super Matched Pair 5687 Vacuum Tubes Tung-Sol AF JTL Same Date Code 8/60 NOS*
  
*MATCHED PAIR GE JAN 5687 WB Black Plate GREEN LABEL​*  
*AMPEREX 7119 ECC182 5687 12AU7 PQ VACUUM TUBE 1970*
  
*and the corresponding adapters*


----------



## gibosi

Bravo!


----------



## jaywillin

all the adapters are coming from china, so, it might be a while


----------



## Ctritical Bill

Firstly I would like to apologise to Mordy for not replying to his PM he sent months ago. I have not been checking this forum for over a year.
 You may remember that I was keen on the russian sub-miniature tubes and recently I ordered some 6N16B-VR to add to my collection. When I received the package I found I had been sent 6N16G-VIR instead. Here is a picture with a standard 6N16B-V on the left for comparison.
  

  
 As you can see, much larger but electrically the same, except for an internal shield and the plate dissipation is up to 1.2W. This was made at the Melz plant in Moscow in 1979.
 I have to say this is a very good tube with a great soundstage and sense of ambiance. Only had it running for less than an hour so it can only improve but highly recommended. There is just one seller on ebay at the moment who has some so if you are interested get in quick.
  

  
 I solder the legs of these tubes into an 8 pin dip socket and then I can simply plug it into another socket on the breadboard. This is a universal board that I can use on other amps by simply changing the leads and it has an in-built voltage regulator so no need for separate heater connections. Also I have it wired so I can use it with two single triodes or one dual triode.


----------



## gibosi

Very interesting! I tried a Melz 6N16B-VR some time ago. It too has a shield, so 9 leads. I very crudely mounted mine into an octal base. lol. 
  

  
 Like your 6N16G-VIR, I found the VR to have a wonderful 3-D stage and ambiance. However, the vocals are a bit thin, and on some recordings, even a bit raspy. (This in an LD 1+, MUSES02 opamp and Senns 700.) And I should note that I heard the same raspy vocals with the 9-pin miniature 6N5P and 6N1P-E. Of the Russian tubes I have tried, the mid-1970s 6N23P are the best, with exceptional staging and ambiance, plus the vocals are smoother and have more body. I wonder if your VIR is more similar to the VR or the 6N23P....
  
 To my ears, the best of the four sub-miniatures in my possession (including the Sylvania 6021 and Raytheon 6832) is the Sylvania 7963. It has all the 3-D magic of the 6N16B-VR plus that warm, silky-smooth Sylvania mid-range.


----------



## Ctritical Bill

I too have some 6N23P but I don't like them that much. I find the whole 6DJ8 family too analytical and cold.
 This 6N16G-VIR has a similar sound to the 6N16B but more of the "magic". I don't notice raspy vocals but I am using a ( now quite modified ) LD 3 so that may be the difference.
 Others I really like are the single triode version of the 6N16B - the 6S6C, and a G.E. 5star 6021 . I have tried a lot of the pentode versions but they don't impress. I think the 6N16G-VIR is the best of the bunch.


----------



## gibosi

Thanks for telling us about this. I should have one shortly.


----------



## mab1376

Anyone have any NOS tung-sol 6SN7 they wanna get rid of?
  
 everything on ebay is $100 ish.


----------



## mordy

Hi mab1376,
  
 You must be looking for a specific Tung Sol 6SN7 because I just checked and there are dozens of listings for far less than $100:
  
 http://www.ebay.com/sch/i.html?_from=R40&_sacat=0&_nkw=Tung+Sol+6SN7&_sop=15


----------



## adtrance

gibosi said:


> Very interesting! I tried a Melz 6N16B-VR some time ago. It too has a shield, so 9 leads. I very crudely mounted mine into an octal base. lol.
> 
> 
> 
> ...


 
 Man you guys are hardcore.  I understand a hobby is an iterative process but the things you guys do for the sake of trying new tubes is pretty amazing.


----------



## gibosi

adtrance said:


> Man you guys are hardcore.  I understand a hobby is an iterative process but the things you guys do for the sake of trying new tubes is pretty amazing.


 
  
 Where there is a will there is a way. lol


----------



## mab1376

Yeah, should have clarified, specifically VT-231 variants. 
  
 Either Tung Sol or Ken Rad
  
 I would be fine with newer GTB variants if it has good bass performance.


----------



## mordy

Looks like Ken Rad is the way to go on a budget.
  
 http://www.ebay.com/sch/i.html?_from=R40&_sacat=0&_nkw=Ken+Rad+VT-231&LH_Complete=1&LH_Sold=1&rt=nc
  
 This link takes you to recent SOLD LISTINGS (last checkbox on the left of Ebay search screen). The least expensive went for $16 each, and several pairs for $60 (did not check shipping costs).
  
 This tells you what the current lowest market price is. With a little patience you will be able to get the Ken Rads for a relatively good price. However, I am sure that there are 6SN7 variants equally good for much less. Although I have not heard the VT-231 variants, I would suggest looking for a pair of RCA 60's 6SN7 tubes with a thin horizontal heater wire above the top mica. If you find a rebranded one it will be even less. These tubes I did try and found very good sounding.
  




  




  
 So far no one has corroborated my like of these tubes.....


----------



## mab1376

Thanks for the info!


----------



## Acapella11

mab1376 said:


> Yeah, should have clarified, specifically VT-231 variants.
> Either Tung Sol or Ken Rad
> I would be fine with newer GTB variants if it has good bass performance.


 
  
 Quote:


mordy said:


> Looks like Ken Rad is the way to go on a budget.
> http://www.ebay.com/sch/i.html?_from=R40&_sacat=0&_nkw=Ken+Rad+VT-231&LH_Complete=1&LH_Sold=1&rt=nc
> This link takes you to recent SOLD LISTINGS (last checkbox on the left of Ebay search screen). The least expensive went for $16 each, and several pairs for $60 (did not check shipping costs).
> This tells you what the current lowest market price is. With a little patience you will be able to get the Ken Rads for a relatively good price.


 
  
 Just bought a pair of Ken-Rad VT231 for $66.95, lol. Burning them in now and so far, they sound generally speaking, very promising! This statement is not to be underestimated .


----------



## buldogge

Finally got the Chinese "gold" sockets to finish the 6SN7/C3G adapter plate...
  
 Is it normal for the pins to be able to slide up and down in the ceramic?
  
 Looks like the one set (6SN7) have the tubular pins that need careful spreading.
  
 Now I need to create a clear picture/understanding of the wiring diagram...
  
 -Mark in St. Louis


----------



## mab1376

acapella11 said:


> Just bought a pair of Ken-Rad VT231 for $66.95, lol. Burning them in now and so far, they sound generally speaking, very promising!




I've read they have amazing bass response which I want very much for live drum recordings.


----------



## gibosi

E182CC/7119 update.
  
 As some of you might remember, I have two of these, one manufactured in 1962 by Philip's Heerlen factory, and the other manufactured in 1972 by Philip's New York factory. I should note that I run these tubes as drivers in an LD 1+. This evening I was able to spend some time listening and comparing, and as expected, the Heerlen tube is a bit more lush than the New York tube. Again, this is not a surprise to me, as I noticed the same differences when comparing Philips E88CCs manufactured in Heerlen and New York.
  
 So next I rolled my favorite of the Philips 6DJ8 family, a 1961 E88CC/6922 manufactured in New York. It sounds very similar to the NY E182CC, but just a bit thinner in the upper bass/lower midrange.
  
 Next, I rolled in the Telefunken 6463. It sounds most like the New York E88CC, but I believe it is a bit cleaner and more transparent. On the other hand, the NY E182CC has just a bit more body and fullness in the midrange than the E88CC and the 6463.
  
 Of all these, I think I prefer the NY E182CC. However, this quick comparison was quite limited, allowing me to discern only a few differences in tonality and not much else.  My feeling is that I need to spend more time with both the NY E182CC and the Telefunken 6463 in order to better understand what I am hearing.
  
 Again these differences in tonality are quite small, and I enthusiastically recommend all of them, the NY E88CC, both the NY and Heerlen E182CC and the Telefunken 6463. These are all terrific tubes.


----------



## Nic Rhodes

gibosi said:


> Not sure which post you are responding to...
> 
> What we need is more info on alternatives to the 6N6-type power tubes for the LD II, III and IV.
> 
> ...


 
  
 Sorry if I have explained this poorly gibosi. I have about 90x E182CC here and it would take seconds to pop into the adapter as output tube if anyone was interested in something specific. Similarly almost 150x 5687s.
  
 So for E182CC they are printed as say Mullards from Holland, Great Britiain and USA. [Some also marked foreign but probably Holland], Valvo West Germany, GE, USA, Amperex, USA, Philips, USA and Holland. Most are probably Mullard marked however.


----------



## buldogge

Hey guys...Got a slightly unrelated question.  I picked up a MK III on the cheap, seller says static in left channel...I can induce or eliminate the static by moving the tube (any tube) around in the left driver socket.
  
 I pulled the board (whew) and checked the soldering...all good.  Both 7-pin sockets are "loose" in their construction.  Is this normal?  You can twist the bodies (not the pins soldered to the PCB) axially a bit and feel play in the "cap".
  
 Any thoughts???
  
 I posted in the MK III mods thread, but that thread is barely breathing...so...anyone here with board mods, that has thoughts in that arena, would love your thoughts on cap replacement choices/etc.
  
 TIA
 -Mark in St. Louis


----------



## Nic Rhodes

pinch the pins with some needle nose pliers in the pin sockets when off for a while, clean and straighten pins of tubes if you can.


----------



## buldogge

Hey Nic...Will do.  Weird thing is, the pin sockets are rather tight already.  Is the looseness of the ceramic body "normal".
  
 TA
 -Mark


----------



## Nic Rhodes

yes often wobbly in the ceramic but should be tight when soldered to pcb. They look bad when in your hand but get better when soldered in. No harm in pinching them a little to get a tight connection.


----------



## gibosi

nic rhodes said:


> ...............I have about 90x E182CC here and it would take seconds to pop into the adapter as output tube if anyone was interested in something specific. Similarly almost 150x 5687s.
> 
> So for E182CC they are printed as say Mullards from Holland, Great Britiain and USA. [Some also marked foreign but probably Holland], Valvo West Germany, GE, USA, Amperex, USA, Philips, USA and Holland. Most are probably Mullard marked however.


 
  
 About 90x E182CC accumulated over many years... What a wonderful collection!
  
 In addition to Philips and Amperex, I often see eBay listings for E182CC with Mullard, Valvo and even Telefunken labels. However, on close examination of the pictures, these always have etched Heerlen or Hicksville, NY production codes. But I have long wondered... Were any E182CC manufactured in Eindhoven before the Heerlen plant opened? Or in Britain by Mullard? Or in Hamburg by Valvo? It occurs to me that if so, you likely have specimens in your collection... If such tubes do in fact exist, I for one would be very curious to know how they compare to the Heerlen and NY tubes.


----------



## buldogge

nic rhodes said:


> yes often wobbly in the ceramic but should be tight when soldered to pcb. They look bad when in your hand but get better when soldered in. No harm in pinching them a little to get a tight connection.


 

 Hey Nic...TA...The pins aren't wobbly at all...the ceramic body is "loose"...it can be rotated slightly on its axis/twisted...pins stay solidly put in the PCB...pins in the socket are tight.
  
 -Mark


----------



## Nic Rhodes

buldogge said:


> Hey Nic...TA...The pins aren't wobbly at all...the ceramic body is "loose"...it can be rotated slightly on its axis/twisted...pins stay solidly put in the PCB...pins in the socket are tight.
> 
> -Mark


 

  Two side of the same coin, often the pins are not solid with the body, not uncommon Mark. It is the electrical connection that is important more than the ceramic bit. That jsut keeps stuff separate.


----------



## Acapella11

mab1376 said:


> I've read they have amazing bass response which I want very much for live drum recordings.


 
  
 Hi mab, from an initial very preliminary comparison, Ken-Rad VT231 vs. Sylvania 6SN7WGT, the differences are quite significant. The K-R sounds darker, with more bass bias, lusher and with female voices more "seducing", which makes the Sylvanias then sound a bit thinner and brighter, resulting for example in more aggressively sounding guitar plucks. I am not yet sure whether the darker character of the K-Rs also results in a blacker background and more details.
 The K-Rs are a good match with the HD800.


----------



## buldogge

nic rhodes said:


> Two side of the same coin, often the pins are not solid with the body, not uncommon Mark. It is the electrical connection that is important more than the ceramic bit. That jsut keeps stuff separate.


 

 Got it...Thanx.  So I guess the only other failure mode would be if there was internal break of a pin.
  
 Moot point right now...Dealing with attempting to rewire this volume pot and it's cramped tiny wiring!!
  
 TA
 -Mark


----------



## i luvmusic 2

I have a channel imbalance from my 1+ it's a shame i need to butcher it again


----------



## buldogge

Ok...Getting ready to tackle the 6SN7/C3G adapter today.  I've attached a couple pics...Could anyone confirm that i have the pins numbered correctly?  Also, Is Hypnos pin-out correct here in post #8157?


----------



## hypnos1

buldogge said:


> Ok...Getting ready to tackle the 6SN7/C3G adapter today.  I've attached a couple pics...Could anyone confirm that i have the pins numbered correctly?  Also, Is Hypnos pin-out correct here in post #8157?


 
  
 Hi buldogge.
  
 Congrats on tackling the adapters...do please be VERY careful  
	

	
	
		
		

		
			





.
  
 Re the C3g pin-out numbering, all has been well with my own lol!
  
 These particular sockets (for the C3g) can be extremely tight - both the central metal spigot AND the pin holes. So I suggest doctoring the former as per the tutorial or else the tube will be grabbed and held REAL hard!  And be sure to loosen the pin holes a bit - I used a tiny screwdriver like those for mending spectacles. Both these measures are to avoid the catastrophes that some of us suffered through forcing the tubes into/out of the sockets - the tube's glass base cracks VERY easily if 'worked/rolled' from side to side...you MUST be able to just push the tube in STRAIGHT. The same goes for removing it - but I suggest NOT removing it once in, unless absolutely necessary!
  
 I hope all goes well for you...the effort will be worth it in the end. Any questions, feel free to ask...
  
 Cheers,
  
 CJ
  
 ps...Re your socket numbering, you will be ok so long as #1 is to YOUR left of the indent as you look down on the socket's underside (as in your photo...).


----------



## buldogge

^^^So, my numbering looks correct then?
  
 On the plug end (both 7 and 9 pin...with the open end of the 'C' facing left the pins are number 1-X  counterclockwise starting at the bottom left...correct???
  
 -Mark


----------



## hypnos1

buldogge said:


> ^^^So, my numbering looks correct then?
> 
> On the plug end (both 7 and 9 pin...with the open end of the 'C' facing left the pins are number 1-X  counterclockwise starting at the bottom left...correct???
> 
> -Mark


 
  
 Hi Mark.
  
 Not sure what you refer to as the 'plug' end...looking at the tube's pins from the bottom (tube upturned) and the gap to the bottom, those with the 'C' always run 1-X CLOCKWISE starting bottom (your) left.
 Hope this clarifies things...
  
 ps.  As you look down at the sockets IN THE AMP the pin holes then run counterclockwise starting bottom right...


----------



## mordy

Re the C3g tubes the center notched pin hole may be tight in the Chinese made sockets. It is important to try to loosen it up with a needle nose pliers or similar.
  
 As mentioned, and unfortunately experienced by several members of the forum, these tubes break easily. Rocking the tubes back and forth to insert or remove (tube rolling) may cause the tube glass envelope to hit the metal shield casing, or perhaps cause stress in the glass envelope, causing fractures in the glass.
  
 These tubes must be inserted straight in or out. I found it helpful to use a small flat blade screw driver to ever so gently work around the tube base and lift up the tube in very small increments until it could be easily pulled out.
  
 The metal casing is just crimped on to the loctal base, and JacMusic suggested to remove the metal shield to make it safer to insert or pull out.
  
 Here is a post mortem on a cracked C3gS tube, showing how the casing is crimped to the base:
  
  




  
 (I used a little flat blade screwdriver to open up the crimping.)


----------



## buldogge

hypnos1 said:


> Hi Mark.
> 
> Not sure what you refer to as the 'plug' end...looking at the tube's pins from the bottom (tube upturned) and the gap to the bottom, those with the 'C' always run 1-X CLOCKWISE starting bottom (your) left.
> Hope this clarifies things...
> ...


 

 We're saying the same thing...I was plotting them with the pins facing down...you're plotting them in plan view.  In my pic, the black wire is #1.
  
 What about the 8 pin sockets?  Looking at them from the bottom (pin side), how are they numbered in relation to the "notch"...same way?  #1 on the left, and clockwise (as my pic)??
  
 TA
 -Mark


----------



## gibosi

buldogge said:


> Ok...Getting ready to tackle the 6SN7/C3G adapter today.  I've attached a couple pics...Could anyone confirm that i have the pins numbered correctly?  Also, Is Hypnos pin-out correct here in post #8157?


 
  
 Just to clarify...   Are you trying to build a C3g to 6AK5 adapter? Or a C3g to 6SN7 adapter? In post #8157, Hypnos1 shows how to construct a C3g to 6AK5 adapter. Constructing a C3g to 6SN7 adapter, which might be used in an amp with two 6SN7 drivers, is a very different kind of undertaking....


----------



## hypnos1

buldogge said:


> We're saying the same thing...I was plotting them with the pins facing down...you're plotting them in plan view.  In my pic, the black wire is #1.
> 
> What about the 8 pin sockets?  Looking at them from the bottom (pin side), how are they numbered in relation to the "notch"...same way?  #1 on the left, and clockwise (as my pic)??
> 
> ...


 
  
 Hi again Mark.
  
 Glad we're on the same tack in the end!
  
 Re the 8-pin sockets -  yes, they run the same way from the 'notch'.
  
 Gibosi has a good point...I presume you are adapting the C3g as driver and the 6SN7 as power?...
  
 Cheers!


----------



## buldogge

^^^You guys are both correct.  I'm making the C3G to 6AK5 now and I will do the 6SN7s shortly.
  
 I'm using a Lexan plate on a stand, so I can move it between the MKII and MKIII (when I fix the volume pot...sigh.) for now...not the prettiest thing, but it should do the job.
  
 -Mark


----------



## i luvmusic 2

I just replaced the POT for my LD 1+ the sound opens up.


----------



## buldogge

What volume pot did you use???  I'm thinking of using this:  http://www.ebay.com/itm/DACT-Type-21-Stepped-Attenuator-Potentiometer-100K-2A3-/201239685917
  
 TIA
 -Mark
  
 Quote:


i luvmusic 2 said:


> I just replaced the POT for my LD 1+ the sound opens up.


----------



## buldogge

Well...That  was disappointing after an afternoon of work.
  
 I just got nada, zero, zilch out of the MK II after installing the C3Gs...No noise...no hum...no static...no music...no nuthin'!
  
 Tubes start getting warm...so I guess the heater circuit works...???  Could be dead tubes I suppose...bought from eBay, German seller.  
  
 Wish I knew settings to use on my tester of these...
  
 -Mark


----------



## i luvmusic 2

buldogge said:


> What volume pot did you use???  I'm thinking of using this:  http://www.ebay.com/itm/DACT-Type-21-Stepped-Attenuator-Potentiometer-100K-2A3-/201239685917
> 
> TIA
> -Mark
> ...


 
 I used the POT that came with my CRACK,I never used it so i installed it into my 1+ I will be replacing it with either a attenuator or ALPS Blue Velvet Pot.


----------



## buldogge

6SN7 Power tube adapters worked out just fine.  Used the plot posted by Artsi on p.264.  Running the Tung Sol Mouse Ears now...very smooth...a little laid back...had to up the volume a couple notches.
  
 Bummer about the C3Gs...Guess I'll email the eBay seller.
  
 -Mark


----------



## hypnos1

buldogge said:


> Well...That  was disappointing after an afternoon of work.
> 
> I just got nada, zero, zilch out of the MK II after installing the C3Gs...No noise...no hum...no static...no music...no nuthin'!
> 
> ...


 
  
 Hi Mark.
  
 That's a real bu**er!...Oh the joys of DIY adapter making!!
  
 Of course you've checked several times your routing? 
  
 It was difficult to tell from your photo, but I presume when you say #1 (black) starting from bottom left, that is from the side of the gap nearest to you?
  
 Did you loosen the pin holes in the socket? If so, are some now TOO loose?
  
 It is rather unusual that both tubes would be faulty - are they used?
  
 I do hope you get sorted OK in the end...


----------



## buldogge

Quote: 





hypnos1 said:


> Hi Mark.
> 
> That's a real bu**er!...Oh the joys of DIY adapter making!!
> 
> ...


 

 Hey hypnos... The wiring matches your chart on post #8157.  With the bottom (LD end) pins facing up, opening of the 'C' facing down, I am numbering 1-7 clockwise.  With the socket turned upside down, with the notch on center bottom, I am numbering 1-8 clockwise.  Continuity is checked.  Pins are still relatively tight.
  
 Pic below:
 LD wiring=
 1=Black
 2=Red
 3=Blue
 4=White
 5=Green
 6=Yellow
 7=Orange

 -Mark


----------



## buldogge

OK...Small update on the C3G...There IS output...*very, very low*...volume pot turned to MAX???
  
 Should the C3Gs be set to EF95 or EF92?
  
 What would a gain issue point o with these tubes???
  
 TIA
 -Mark


----------



## buldogge

Ok...Finish this conversation with myself...Obviously EF95 setting is correct.  I have output now.  Had to play with the tubes in those cheap Chinese socket though.  Basically, can't touch the adaptors/tubes or they cut out...assuming the crappy pins.
  
 Guess I'll order some NOS or maybe some of those Russian sockets Mike got.
  
 Anyone tried these?:
 http://www.ebay.com/itm/Cinch-NOS-Vintage-Loctal-Loktal-8-pin-tube-socket-/400772825220?pt=LH_DefaultDomain_0&hash=item5d4fec0084
  
 TA
 -Mark


----------



## TrollDragon

These Amphenol's might be your best bet for a decent socket.
 http://www.ebay.com/itm/NOS-Amphenol-8-Pin-Loctal-Loktal-Tube-Socket-for-7N7-7AF7-type-tubes-/221681170614


----------



## hypnos1

buldogge said:


> Ok...Finish this conversation with myself...Obviously EF95 setting is correct.  I have output now.  Had to play with the tubes in those cheap Chinese socket though.  Basically, can't touch the adaptors/tubes or they cut out...assuming the crappy pins.
> 
> Guess I'll order some NOS or maybe some of those Russian sockets Mike got.
> 
> ...


 
  
 Glad you finally sorted it Mark...yes, those particular sockets do leave a lot to be desired, lol!


----------



## gibosi

......


----------



## WilliamLeonhart

Sent my LD I+ for repair yesterday. Still can't figure out why they have buzz and noises.


----------



## jaywillin

williamleonhart said:


> Sent my LD I+ for repair yesterday. Still can't figure out why they have buzz and noises.


 
 Little dots are known to pick up interference , my mkiii is dead silent most of the time, but occasionally it'll pick up some noise
 i had a I+ that was silent all the time, and one that was noisy as hell, and not matter what i did, stayed that way
 good luck !


----------



## jaywillin

jaywillin said:


> Little dots are known to pick up interference , my mkiii is dead silent most of the time, but occasionally it'll pick up some noise
> i had a I+ that was silent all the time, and one that was noisy as hell, and not matter what i did, stayed that way
> good luck !


 
  
 well, it wasn't the mkiii at all, it was one of the 6hm5's being a little noisy, and that just developed
 i put in my mullard 6ak5's, -silent


----------



## GravitySmacked

Hi folks,

Could do with some advice please.

I bought the following EF95 tubes for my Little Dot Mk1+

http://www.ebay.co.uk/itm/251789963059?_trksid=p2060778.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT

However I've noticed a reasonably loud humming noise coming from them even with the volume on my Little Dot turned down. 

I'm under the assumption no jumper settings need changing with these, as they are EF95's, so have I bought duds?

Cheers


----------



## gibosi

gravitysmacked said:


> I bought the following EF95 tubes for my Little Dot Mk1+
> 
> http://www.ebay.co.uk/itm/251789963059?_trksid=p2060778.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT
> 
> ...


 
  
 They might be duds, but most likely there is nothing really wrong with them. New tubes often buzz and hum, so run them for 20 hours or so, and see if they don't quiet down.
  
 Good luck!


----------



## GravitySmacked

Thanks for replying  

Does this apply to 'old' new tubes? These were supposedly made in the 60's. 

Also do I need to have music playing through them or is just having them switched on enough when burning in? 

Sorry for the stupid questions.


----------



## gibosi

gravitysmacked said:


> Thanks for replying
> 
> 
> 
> ...


 
  
 Yes. Even though these Russian tubes were manufactured in 1966, they have never been used. Again, new tubes, tubes that have never been used, need to be burned-in. And it doesn't matter if they were manufactured in 1945 or 2015. 
  
 It is generally considered best practice to have a set of headpones plugged in when any amp is on, but not when turning it on or off. That is, it is best to turn an amp on, wait a minute or two, and then plugin the phones. And likewise, unplug the headphones first, and then turn the amp off. This protects your ears and your headphones in the event that the tube fails catastrophically. Further, I always use a very cheap pair of headphones when burning in new tubes.
  
 I am not sure that it is absolutely necessary to run a signal through them, but I do.  I like to be able to listen every several hours or so, to see if they tubes are quieting down. I just run a CD player on repeat.


----------



## GravitySmacked

Thanks for the information; I'll give it a go and see how I get on


----------



## GravitySmacked

Just a quick update; I ran the tubes for about 10 or so hours today and the hum is much quieter already! So far, so good


----------



## WilliamLeonhart

jaywillin said:


> well, it wasn't the mkiii at all, it was one of the 6hm5's being a little noisy, and that just developed
> i put in my mullard 6ak5's, -silent


 
 My LD I+ came with 6cq6 tubes, but one of the 2 went dead after I moved house, so I bought Mullards CV4010 to replace them instead. It would be worse if the tubes caused the buzz, cos I bought them in Singapore and won't return to the country in the near future... Damn


----------



## WilliamLeonhart

gibosi said:


> Yes. Even though these Russian tubes were manufactured in 1966, they have never been used. Again, new tubes, tubes that have never been used, need to be burned-in. And it doesn't matter if they were manufactured in 1945 or 2015.
> 
> It is generally considered best practice to have a set of headpones plugged in when any amp is on, but not when turning it on or off. That is, it is best to turn an amp on, wait a minute or two, and then plugin the phones. And likewise, unplug the headphones first, and then turn the amp off. This protects your ears and your headphones in the event that the tube fails catastrophically. Further, I always use a very cheap pair of headphones when burning in new tubes.
> 
> I am not sure that it is absolutely necessary to run a signal through them, but I do.  I like to be able to listen every several hours or so, to see if they tubes are quieting down. I just run a CD player on repeat.


 
 Thanks for the tips. So far you have helped me tremendously


----------



## Gravit8

Hey all! First off, I have a Little Dot MkII. With 6N6P-IRs power, and 6HM5s up front.  The problem I'm having is tube feedback? Not sure if that's the correct term.  If you were to flick one of your tubes, and get a pinging sound, that's what I'm getting but almost at random, near anything will set them off. For instance, I'll sneeze (literally) and the tubes will ring for 10+ seconds unless I put my finger on them (stops the vibrating?).  Also, when I shut off the amp, the tubes all click like crazy (cooling down?).  All these side affects are something I didn't have with the stock tubes that came with it. Is this all normal for these tubes?  I have multiple pairs of 6HM5, and they all do this.


----------



## buldogge

Hey Guys...Quick question re: a pair of Tung Sol Mouse Ears 6SN7s I have...I ended up with (3) tubes...Two test strong, one just OK...One of the strong ones has a much brighter glow at the center wire which protrudes thru the top plate/mica.  Is this glow an indication of anything...one way or the other...positive or negative?  The other (2) have no noticeable glow there...
  
 ???
  
 TIA
 -Mark in St. Louis


----------



## TrollDragon

I have a few tubes with a bright filament glow at the top and they work fine. I think it is just a little too much filament at the top during the manufacturing process and the bottom seems to have the same glow as the other tube.
  
 I like the standoff's soldered to the copper pipe sides for the socket mounting screws.


----------



## buldogge

Thanx TD...Just waiting on those Amphenol loktal sockets now, to make final adapters for the C3Gs...it's touch and go every time something is moved with those chinese sockets...
  
 Also, need to replace the volume pot on the MK III I picked up...Anyone have soldering tips when working with a pot?  In and out quickly, I presume??
  
 -Mark


----------



## TrollDragon

I have the ALPS Blue Velvet in the MK IV, I am not sure what is in the MK III.
 A solder sucker or some dry wick will work good, the boards traces are fairly decent.


----------



## TrollDragon

gravit8 said:


> Hey all! First off, I have a Little Dot MkII. With 6N6P-IRs power, and 6HM5s up front.  The problem I'm having is tube feedback? Not sure if that's the correct term.  If you were to flick one of your tubes, and get a pinging sound, that's what I'm getting but almost at random, near anything will set them off. For instance, I'll sneeze (literally) and the tubes will ring for 10+ seconds unless I put my finger on them (stops the vibrating?).  Also, when I shut off the amp, the tubes all click like crazy (cooling down?).  All these side affects are something I didn't have with the stock tubes that came with it. Is this all normal for these tubes?  I have multiple pairs of 6HM5, and they all do this.


 

 The microphonics (pinging) you mention can happen in any tube but my 6HM5's do not have this. Are all the 6HM5's from the same seller? If so he or someone might have dropped the case of them at some point which would loosen up the tubes internals and make them very microphonic.
  
 Have you swapped out the 6HM5's for the 5654 stock driver tubes to see if it is the output tubes making the noise?


----------



## buldogge

trolldragon said:


> I have the ALPS Blue Velvet in the MK IV, I am not sure what is in the MK III.
> A solder sucker or some dry wick will work good, the boards traces are fairly decent.


 

 Hey TD...The MKIII pot mounts to the faceplate and runs a JST 4S (5 pin) extension lead to a socket on the PCB.  I'm going to replace it with this pot:
  
 http://www.ebay.com/itm/201239685917?_trksid=p2059210.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT
  


 My concern is simply heat/damage at the pot interface...???
  
 TA
 -Mark


----------



## TrollDragon

I wouldn't see any problem soldering to that at all. I would tin the via's first then solder your wires to them.
  
 Unless your using one of the old board chewers... 
	

	
	
		
		

		
		
	


	




 Then it would be time for an upgrade to a nice Hakko FX-888D or similar. 
	

	
	
		
		

		
		
	


	



  
  
 I still use my Weller WCPL that I was given for a birthday present back in the 70's...

 Many, Many miles on the old girl and many thousands of solder connections.


----------



## buldogge

Thanx TD...My OE MKIII Alps pot was wonky when I got it (bought it cheapish, as broken)...tried to repair it...seems the connections/connectors/vias? loosened while de-soldering and re-soldering.  
  
 I'm just using a run-of-the-mill Weller 25w....but I also have a simple Weller 80w (need to get a non-chisel tip)...
  
 -Mark


----------



## MIKELAP

trolldragon said:


> I have the ALPS Blue Velvet in the MK IV, I am not sure what is in the MK III.
> A solder sucker or some dry wick will work good, the boards traces are fairly decent.


----------



## gibosi

This looks very interesting... A way to improve our LDs that is a bit less drastic than replacing capacitors....   Could this "DACT Type 21 Stepped Attenuator Potentiometer 100K" referenced above by Buldogge be used in an LD 1+?


----------



## gibosi

A National Union 6F8G arrived here the other day:
  
 The NU with round plates is ranked as one of the best 6F8G by a number of folks, so was pleased to find this Philco rebrand for a good price. The Philips date-code is "3S" which suggests that it was labeled and packaged by Philco in the last quarter of 1943. Next to it is a grey-glass National Union VT231/6SN7GT probably manufactured in the mid 1940s. (Is anyone out there able to translate National Union date codes?  "GU"?)
  
 I personally prefer the sound of the grey-glass NU 6SN7 over the black-glass version and am interested to see how the 6F8G compares.


----------



## MIKELAP

gibosi said:


> A National Union 6F8G arrived here the other day:
> 
> The NU with round plates is ranked as one of the best 6F8G by a number of folks, so was pleased to find this Philco rebrand for a good price. The Philips date-code is "3S" which suggests that it was labeled and packaged by Philco in the last quarter of 1943. Next to it is a grey-glass National Union VT231/6SN7GT probably manufactured in the mid 1940s. (Is anyone out there able to translate National Union date codes?  "GU"?)
> 
> I personally prefer the sound of the grey-glass NU 6SN7 over the black-glass version and am interested to see how the 6F8G compares.


 
 Received several 6f8g waiting for adapters  Glenn made for my tubes. was asking guys in WooAudio thread about branding and its a real mess looks like you really have to see the tube regarding the structure .So far what i found was that Westinghouse ,Philco, Tung Sol, can be similar or not ,RCA ,SYLVANIA ,G.E,RAYTHEON , also G.E. and Kenrad can be similar or not theres seems to be more than one structure type for the same brand like i said a mess .Like my Westinghouse plates looks similar to your Philco


----------



## buldogge

gibosi said:


> A National Union 6F8G arrived here the other day:
> 
> The NU with round plates is ranked as one of the best 6F8G by a number of folks, so was pleased to find this Philco rebrand for a good price. The Philips date-code is "3S" which suggests that it was labeled and packaged by Philco in the last quarter of 1943. Next to it is a grey-glass National Union VT231/6SN7GT probably manufactured in the mid 1940s. (Is anyone out there able to translate National Union date codes?  "GU"?)
> 
> I personally prefer the sound of the grey-glass NU 6SN7 over the black-glass version and am interested to see how the 6F8G compares.


 
 Are the grey glass NUs made by NU...any other brands they were sold as to look for?  The black and grey glass tubes seem to go for silly (to me) money...
  
 TIA
 -Mark


----------



## buldogge

gibosi said:


> This looks very interesting... A way to improve our LDs that is a bit less drastic than replacing capacitors....   Could this "DACT Type 21 Stepped Attenuator Potentiometer 100K" referenced above by Buldogge be used in an LD 1+?


 

 As long as there is 21mm D clearance to the PCB, I wouldn't see why not...might use solid pins/wire to connect it to the PCB.
  
 -Mark


----------



## gibosi

mikelap said:


> Received several 6f8g waiting for adapters  Glenn made for my tubes. was asking guys in WooAudio thread about branding and its a real mess looks like you really have to see the tube regarding the structure .So far what i found was that Westinghouse ,Philco, Tung Sol, can be similar or not ,RCA ,SYLVANIA ,G.E,RAYTHEON , also G.E. and Kenrad can be similar or not theres seems to be more than one structure type for the same brand like i said a mess .Like my Westinghouse plates looks similar to your Philco


 
  
 This is especially true regarding the Tung Sol. I have seen some with round plates and some Sylvania-style shiny black T-plates. From what I have read, both of them are wonderful, but if you are looking for a pair, they just might sound a bit different. I have also noticed that Sylvania and RCA tubes manufactured in the 1940s have grey-smoked glass, but in the 1950s, the smoked glass was discontinued. As a consequence, good pictures are especially important. If I can't see the details in the pictures, I ask for better pictures. And if they don't comply, I pass.
  
 Regarding National Union, I spent quite a bit time studying lots of pictures on eBay, and when I found the Philco rebrand, I was able to compare it to these pictures. Apparently, unlike their 6SN7s, National Union never used smoked gray or black glass in their 6F8G. Judging from the shape of the plates, the clear glass bottle, the two copper support rods, the shape of the micas and the way the copper wire connected to the top grid cap is twisted and terminated, I feel very certain that the Philco is a National Union.
  
 Mikelap: Yours sure looks like a National Union except the shape of the micas. On all the National Unions I have seen, the micas are somewhat rectangular with smooth long sides and spikes on the shorter rounded sides that contact the glass. That said, NU used rounded spiked micas on the first version of their black-glass 6SN7, so it may be that yours was manufactured after mine, perhaps in the late 1940s or early 1950s. In the end, if yours is not a NU, then I have no idea what else it could be.


----------



## MIKELAP

gibosi said:


> mikelap said:
> 
> 
> > Received several 6f8g waiting for adapters  Glenn made for my tubes. was asking guys in WooAudio thread about branding and its a real mess looks like you really have to see the tube regarding the structure .So far what i found was that Westinghouse ,Philco, Tung Sol, can be similar or not ,RCA ,SYLVANIA ,G.E,RAYTHEON , also G.E. and Kenrad can be similar or not theres seems to be more than one structure type for the same brand like i said a mess .Like my Westinghouse plates looks similar to your Philco
> ...


 
 Expecting a NU tube next week did not see a picture but for the price i took a chance .


----------



## gibosi

buldogge said:


> Are the grey glass NUs made by NU...any other brands they were sold as to look for?  The black and grey glass tubes seem to go for silly (to me) money...


 
  
 The grey-glass NUs are fairly rare and often go for silly money. I have yet to see a rebranded grey-glass National Union 6SN7GT. However, National Union and Philco were pretty tight, so I wouldn't be surprised to see one of these carrying the Philco brand someday. I currently have three, two with war-time VT-231 and Army Signal Core markings and one with a clean black base with no visible markings. At first glance, these look very similar to the RCA grey-glass. However, the mica spacers attached to the top mica are square whereas they are rectangular on the RCA (and round on the TS mouse-ears). And if the vendor provides a good picture of the top mica, you will see these two very distinctive U-shaped structures on the NU.
  
 On the other hand, the later black-glass NUs can often be found fairly inexpensively, and were often rebranded by Philco, Motorola and others.


----------



## gibosi

buldogge said:


> As long as there is 21mm D clearance to the PCB, I wouldn't see why not...might use solid pins/wire to connect it to the PCB.


 
  
 The next time I open it up, will take a better look and check that clearance. Thanks!


----------



## Oskari

gibosi said:


> However, National Union and Philco were pretty tight, …


 
  
 So tight that Philco bought NU in 1947.


----------



## i luvmusic 2

Since the Attenuator posted above is not designed to mount directly onto the PCB it might be a(bottom space between the PCB and the Attenuator) problem for the LD 1+ but is best suited for the MK III.
  
  I will be replacing the MK III's POT with the ALPS BLUE soon when i got a chance to do it,I just replaced my +1 pot last week.


----------



## gibosi

i luvmusic 2 said:


> Since the Attenuator posted above is not designed to mount directly onto the PCB it might be a(bottom space between the PCB and the Attenuator) problem for the LD 1+ but is best suited for the MK III.
> 
> I will be replacing the MK III's POT with the ALPS BLUE soon when i got a chance to do it,I just replaced my +1 pot last week.


 
  
 So.... which replacement pot do you recommend for the LD 1+?


----------



## i luvmusic 2

gibosi said:


> i luvmusic 2 said:
> 
> 
> > Since the Attenuator posted above is not designed to mount directly onto the PCB it might be a(bottom space between the PCB and the Attenuator) problem for the LD 1+ but is best suited for the MK III.
> ...


 
  Anything that is PCB mounted that have similar size with the stock pot,the one posted above it may work by soldering a wire to the attenuator then to the PCB.My question is is there enough GAP between the Attenuator solder PODS and the PCB? Since my LD 1+ is butchered i will be redoing the pot that i just installed temporarily it will be replace with the ALPS BLUE i will let you know if the ALPS will fit into the LD 1+.


----------



## adtrance

i luvmusic 2 said:


> Anything that is PCB mounted that have similar size with the stock pot,the one posted above it may work by soldering a wire to the attenuator then to the PCB.My question is is there enough GAP between the Attenuator solder PODS and the PCB? Since my LD 1+ is butchered *i will be redoing the pot that i just installed temporarily it will be replace with the ALPS BLUE i will let you know if the ALPS will fit into the LD 1+.*


 




  
 Looking forward to this!


----------



## i luvmusic 2

Hopefully sometime next week........
  
 For the MK III the ALPS BLUE may not fit so i probably need to make a new FACE PLATE or butcher it like what i did to my 1+.


----------



## MIKELAP

i luvmusic 2 said:


> Hopefully sometime next week........
> 
> For the MK III the ALPS BLUE may not fit so i probably need to make a new FACE PLATE or butcher it like what i did to my 1+.


 
 Its seems the pot cant me more than 21mm in dia. for it to fit in the MK3


----------



## MIKELAP




----------



## i luvmusic 2

I've used two of these one for the CRACK and one for the S.E.X.,I Ordered 2 more for the LD 1 and MK III.


----------



## i luvmusic 2

mikelap said:


> i luvmusic 2 said:
> 
> 
> > Hopefully sometime next week........
> ...


 
  I opened mine this morning and it looks like the stock pot is very closed to the PCB but i did not measure it.I may need to make a new Faceplate.
 No matter how difficult it is to fit it into the MK III i will do my best to replace that stock pot,If it wasn't one day i had a channel Imbalanced with the 1+ i would never thought replacing the pot.Definitely those stock pot should be replaced unless you already have the ALPS BLUE VELVET installed like some models.


----------



## gibosi

mikelap said:


> .......Like my Westinghouse plates looks similar to your Philco


 
  
 I believe this is a Raytheon.


----------



## MIKELAP

gibosi said:


> mikelap said:
> 
> 
> > .......Like my Westinghouse plates looks similar to your Philco
> ...


 
 This is a Raytheon i have will check for Raytheon's also to match my Westinghouse   .Thanks


----------



## Acapella11

trolldragon said:


> I have the ALPS Blue Velvet in the MK IV, I am not sure what is in the MK III.
> A solder sucker or some dry wick will work good, the boards traces are fairly decent.




Hi TD, the volume pod is certainly a good point of action to improve SQ. Question, is the Alps Velvet the default MKIV volume control? Have you looked for a stepped attenuator to fit?


----------



## SonicTrance

Hi!
 I've had the LD MKIV SE for about 3 years now but only recently (past 6 months or so) started tube rolling. I've read this thread from the beginning right to the end. It only took me a month or two
	

	
	
		
		

		
		
	


	




 But it was a good read to say the least! So much information in here it's incredible! As most people (I assume) I read the first post and ordered a matched pair of waay overpriced 6ZH1P-EV. Great tubes overall but nothing compared to the 6HM5's I moved on to later as I kept reading this thread. They really took the LD to a new level.
  
 I skipped the breadboard adapters and using double triodes as driver tubes. As I'm into PC modding, naturally I want things to look just as good as it performs. So no flying wires for me, lol. Instead I went straight to the C3G and 6SN7 combo with adapters after reading hypnos1's comments on those tubes. I've only tried 2 sets of powertube replacements yet. First I got the psvane UK-6SN7's. I've never heard such a dramatic change in sound as I did with the psvanes in the LD. Much more clear and detailed sound compared to the stock 6H30PI's. A couple days ago I got a pair of Sylvania 6F8G's with adapters. They are burning in as I type this but first impressions is that they are a tad warmer than the psvane's and not as much bass neither. But that could change as I put more hours on them. Here's some pics of my setup 
	

	
	
		
		

		
		
	


	



 Psvane UK 6SN7 and Siemens C3GS with chinese adapters that I modified to look a little nicer I filed off the socket mounts and painted them matte black.
  




 Here's the 6F8G's. They get quite tall with two adapters Just wanted to say thank you to everyone in this thread for all the usefull information! Oh, and I got a pair of 6N5S's on the way too and an external psu


----------



## TrollDragon

acapella11 said:


> Hi TD, the volume pod is certainly a good point of action to improve SQ. Question, is the Alps Velvet the default MKIV volume control? Have you looked for a stepped attenuator to fit?


 

 The Alps is the default control for the MK IV series, it is cheap and has very good channel matching.
  
 The Dact CT2 on the other hand is an excellent attenuator, but with most 21 step type units I find there is always a time where the current level you are listening to is too low and the next click is too loud. This doesn't happen with a 48 stepped unit like the Khozmo or a 41 step unit like the Acoustic Dimension, unfortunately they are too big to fin in our cases.
  
Goldpoint has 47 step units that will fit, but they are only available in 10K and 50K which will not work.
  
 Then there is this clown, selling a 24 step unit quoted as  "probably the* best attenuator *on this planet". I really don't know about other planets and if there are better ones.


----------



## Acapella11

trolldragon said:


> The Alps is the default control for the MK IV series, it is cheap and has very good channel matching.
> 
> The Dact CT2 on the other hand is an excellent attenuator, but with most 21 step type units I find there is always a time where the current level you are listening to is too low and the next click is too loud. This doesn't happen with a 48 stepped unit like the Khozmo or a 41 step unit like the Acoustic Dimension, unfortunately they are too big to fin in our cases.
> 
> ...



I suggest for him to try Alpha Centauri or Kepler 438b for this comparison, lol.
Gonna stick with the Alps Velvet in the MKIV then.


----------



## gibosi

mikelap said:


> This is a Raytheon i have will check for Raytheon's also to match my Westinghouse   .Thanks


 
  
 Interestingly, this Raytheon has Sylvania-style black T-plates and heat radiators. Very similar. However, 1940s Sylvanias typically have grey-smoked glass bottles, top micas with metal "umbrella spoke" spacers, steel rather than copper grid posts, and a different the way the copper wire connected to the top grid cap is bent.


----------



## TrollDragon

acapella11 said:


> I suggest for him to try Alpha Centauri or Kepler 438b for this comparison, lol.
> Gonna stick with the Alps Velvet in the MKIV then.


 
  
 So many Class M planets and so little time to search them all... There would be some excellent attenuators on Cardassia Prime but you would get better deals on Ferenginar.


----------



## i luvmusic 2

Which planet is closer?I would like to go there and pick up the best POT/ATTENUATOR......
  
 The closest planet to me is planet Partsconnexion 30 minutes away.


----------



## buldogge

Hey guys...For those of you running 40's Ken Rad 6SN7s...Do you notice a vast difference (or any at all) between the angled and straight plate versions???
  
 TIA
 -Mark in St. Louis


----------



## TrollDragon

i luvmusic 2 said:


> Which planet is closer?I would like to go there and pick up the best POT/ATTENUATOR......
> 
> The closest planet to me is planet Partsconnexion 30 minutes away.


 
 Leaving earth on the Defiant would take you around 11 days to get to Terok Nor at a speed of 1816c since it is 52ly away.
  
 Consulting with Stellar Cartography shows Cardassia Prime is 5.2ly away from Bajor and Ferenginar is 65ly away from Bajor. Since Cardassia Prime is only one more day away, it would be you closest location to pick it up in person.
  
 You would have no faster way to get there than on the USS Defiant


----------



## gibosi

buldogge said:


> Hey guys...For those of you running 40's Ken Rad 6SN7s...Do you notice a vast difference (or any at all) between the angled and straight plate versions???


 
  
 If "angled and straight" is your way of saying "staggered and parallel", I am not able to say... Based on comments and observations regarding these two Ken-Rad VT-231 versions in the 6SN7 Reference thread, I have purchased only staggered plate versions. And I can say that these are excellent tubes.
  
 http://www.head-fi.org/t/117677/the-reference-6sn7-thread


----------



## buldogge

gibosi said:


> If "angled and straight" is your way of saying "staggered and parallel", I am not able to say... Based on comments and observations regarding these two Ken-Rad VT-231 versions in the 6SN7 Reference thread, I have purchased only staggered plate versions. And I can say that these are excellent tubes.
> 
> http://www.head-fi.org/t/117677/the-reference-6sn7-thread


 

 Yes and copy.
  
 Thanx.
 -Mark


----------



## MIKELAP

trolldragon said:


> i luvmusic 2 said:
> 
> 
> > Which planet is closer?I would like to go there and pick up the best POT/ATTENUATOR......
> ...


 
 Hey TD would it be asking to much of you , could you drop me off at Risa lol my favorite M class planet a little further away though at 90 light years ill pay for the Dilithium cristal .Thanks.


----------



## i luvmusic 2

That flight is full.........


----------



## TrollDragon

mikelap said:


> Hey TD would it be asking to much of you , could you drop me off at Risa lol my favorite M class planet a little further away though at 90 light years ill pay for the Dilithium cristal .Thanks.


 
  
 Sure Can!

 You just want to go to Risa for the *Jamaharon*...


----------



## MIKELAP

I was planning to use   my 6F8G tubes on my Woo amp but looks like i can plug my 6F8G adapter in my 6sn7 adapter with my MK3 that's a nice bonus great. I did not know that .


----------



## gibosi

buldogge said:


> Yes and copy.


 
  
 And on the chance you haven't found the 6NS7 Identification thread, it too can be very helpful too.
  
 http://www.head-fi.org/t/209782/the-6sn7-identification-guide


----------



## gibosi

sonictrance said:


> Hi!
> I've had the LD MKIV SE for about 3 years now but only recently (past 6 months or so) started tube rolling..... [snip]
> Just wanted to say thank you to everyone in this thread for all the usefull information! Oh, and I got a pair of 6N5S's on the way too and an external psu


 
  
 Welcome to the forum! 
  
 It's great to know that you have benefited from our experiences as we have searched and trialed tube after tube in our amazing Little Dots. And when you get your 6N5Ss and psu up and running, I hope you tell us about your experiences as well.
  
 Since the 6N5S is in fact different than the 6N13S, which many believe to be a best buy, I am very curious how these two compare. Another tube I am curious about is the Chinese Dawn Sound 6N13P.
  
 Soon I expect to obtain an OTL based on a pair of 6AS7 and I can hardly wait to try these myself. 
  
 Cheers!


----------



## mordy

Welcome to the forum MisterX!,,
  
 The way to go for superior bass and overall best performance for the LD is to get the 2.5A power tubes from the 6AS7/6080 families. Congrats on your beautiful work with your mods!


----------



## SonicTrance

gibosi said:


> Welcome to the forum!
> 
> It's great to know that you have benefited from our experiences as we have searched and trialed tube after tube in our amazing Little Dots. And when you get your 6N5Ss and psu up and running, I hope you tell us about your experiences as well.
> 
> ...


 
 Thanks! 
  
 So the 6N13S is believed to be the best buy? Hm, I did not know that. May have to buy some of those to These tubes are so cheap anyway, I got the 6N5S pair for $20 + shipping. They're NOS tubes from 1963, hope they're good I'll share may experience when I got everything setup for sure.
  


mordy said:


> Welcome to the forum MisterX!,,
> 
> The way to go for superior bass and overall best performance for the LD is to get the 2.5A power tubes from the 6AS7/6080 families. Congrats on your beautiful work with your mods!


 
 Thanks! 
  
 Yes, that's what I figured. Lets hope the 6N5S's I got on the way are as good as i hope. Funny thing about rolling power tubes in the LD, I think it impacts the sound just as much if not even more than rolling driver tubes.


----------



## SonicTrance

If anyone was wondering what the difference between the Lorenz C3G and Siemens C3GS looks like, here it is
  




  
 Lorenz on the left and Siemens on the right. Cant say that I noticed a big difference in sound, though the Siemens are a lot quieter than the Lorenz when using my sensitive W1000X cans.


----------



## gibosi

sonictrance said:


> If anyone was wondering what the difference between the Lorenz C3G and Siemens C3GS looks like, here it is
> 
> Lorenz on the left and Siemens on the right. Cant say that I noticed a big difference in sound, though the Siemens are a lot quieter than the Lorenz when using my sensitive W1000X cans.


 
  
 Fascinating! From everything I have read, I was quite sure all C3G were manufactured by Siemens, regardless of the printed brand. And that still may be the case. It is possible that both were manufactured by Siemens, but at different points in time. On the other hand, the differences are quite significant, which does suggest different factories.
  
 Since we can't see the guts when we buy these tubes, I wonder if we could surmise that gold pins = Siemens and standard pins = Lorenz or other source?


----------



## mordy

Some time back when I contacted a prospective seller in Germany he stated that the Lorenz C3g was made in a factory in Berlin by Lorenz. There are Telefunken and Valvo versions of the C3g as well.
  
 Somebody in Germany is selling a large lot of 80 used C3g and C3m tubes:
  
 C3g Telefunken : 50 Stück/ Pcs
 C3g Lorenz : 18 Stück / Pcs
 C3g Siemens : 11 Stück / Pcs
 C3g Valvo : 2 Stück / Pcs
 -------------
 C3m Telefunken 3x
 C3m Lorenz 3x
 C3m Siemens 1x 
  
 So far the bidding is up to around 27 Euro; shipping is Euro 35 to the US. The auction ends in 23 hours.
  
 http://www.ebay.de/itm/KONVOLUT-VON-80-POSTROHREN-C3g-C3m-TELEFUNKEN-SIEMENS-LORENZ-VALVO-/271780920171?pt=R%C3%B6hren&hash=item3f4767bb6b
  
 It is too much for me to absorb. If somebody decides to buy, please save me two Telefunken tubes!


----------



## hypnos1

sonictrance said:


> Hi!
> I've had the LD MKIV SE for about 3 years now but only recently (past 6 months or so) started tube rolling. I've read this thread from the beginning right to the end. It only took me a month or two
> 
> 
> ...


 
  
 Hi MisterX, and welcome...to the most helpful (IMHO) thread in the entire forum lol! This past year and a half has been the best time I've had in years!!
  
 May I say it is MOST refreshing that you have taken the time and trouble to plough through the entire thread...WELL DONE!  I'm sure you have picked up a good few tips over and above the obvious ones - and had a bit of fun also? 
	

	
	
		
		

		
		
	


	




...
  
 And well done for choosing what I firmly believe to be one of the (if not THE!) best driver tubes on the planet...and bravo also for freeing them from their prison. If they are NOS you won't believe either just how much better they get up to (and above) 50hrs' burn-in - you're in for some magical listening methinks (no...I KNOW!).
  
 And as A11 says, you must try the 6N13S powers...I must admit I was very(pleasantly) surprised at how well they perform in my new Feliks-Audio Elise. You would have to spend a good deal more (on something like the Chatham or Tung Sol/Chatham 6AS7G) to get any better performance, IMHO.
  
 You have already taken the humble LD to a level WAY beyond stock....just wait 'til you get those next-step power tubes up and running! 
	

	
	
		
		

		
		
	


	




 (they trounce even my nice PsVane CV181TIIs..)
  
 Happy rolling!...


----------



## mordy

Are there any special years of manufacture to look for with the 6N13S, or maybe it does not matter when they were made? Were there more than one manufacturer (Svetlana)?


----------



## SonicTrance

gibosi said:


> Fascinating! From everything I have read, I was quite sure all C3G were manufactured by Siemens, regardless of the printed brand. And that still may be the case. It is possible that both were manufactured by Siemens, but at different points in time. On the other hand, the differences are quite significant, which does suggest different factories.
> 
> Since we can't see the guts when we buy these tubes, I wonder if we could surmise that gold pins = Siemens and standard pins = Lorenz or other source?


 
  
 Yeah, all Siemens branded ones seems to have gold pins.


hypnos1 said:


> Hi MisterX, and welcome...to the most helpful (IMHO) thread in the entire forum lol! This past year and a half has been the best time I've had in years!!
> 
> May I say it is MOST refreshing that you have taken the time and trouble to plough through the entire thread...WELL DONE!  I'm sure you have picked up a good few tips over and above the obvious ones - and had a bit of fun also?
> 
> ...


 
 Thank you hypnos1! 
  
 Yes, very helpful thread indeed this one A lot of late nights reading through it though
  
 The C3GS's I got are NOS and I'm very happy with them to say the least. Don't really feel the need to roll driver tubes for some time unless I build a nice looking adapter to roll double triodes
	

	
	
		
		

		
		
	


	



  
 So you're also recommending the 6N13S's, damn it, lol. Have you by any chance compared them to the 6N5S's?


----------



## hypnos1

sonictrance said:


> Yeah, all Siemens branded ones seems to have gold pins.
> Thank you hypnos1!
> 
> Yes, very helpful thread indeed this one A lot of late nights reading through it though
> ...


 
  
 Hi again *-MX-*
  
 NOS 'S's?...doubly well done - as the saying goes..."you ain't seen nothin' yet"!!..(50+ hrs, remember?...
	

	
	
		
		

		
		
	


	




).
  
 I applaud your enthusiasm to build for double triodes, and it would be an interesting exercise...but I fear you would have to spend a great deal of money to get anywhere NEAR the C3GSs...
	

	
	
		
		

		
		
	


	




...
  
 I must admit to not having tried the 6N5S, so we all look forward to your comparison?!...
  
 Cheers...


----------



## SonicTrance

hypnos1 said:


> Hi again *-MX-*
> 
> NOS 'S's?...doubly well done - as the saying goes..."you ain't seen nothin' yet"!!..(50+ hrs, remember?...
> 
> ...


 
 Hi,
  
 Like I said I don't feel the need but IF I were to roll driver tubes it has to be double triodes. Because I'm not going back to EF95 tubes, ever
	

	
	
		
		

		
		
	


	




 But first I need to get those 6N5S's up'n runnin. Really looking forward to it


----------



## michaelkeeney

Hello LD crew. Thinking about pulling the trigger on a set of hifiman he560 cans, but wondering about compatabity with the LD mk iii. I've currently got some C3G's and 6SN7's in there right now, but being that the 560's are low impedance cans, I know they won't like the 6SN7's. I'd originally purchased and rolled my mk iii because I was thinking of going the Senn HD 800 route, but have since been semi redirected to the hifiman cans. My endgame amp will be a WA22, but I'm a year away from that still. Anyone have any insight into this? Thanks


----------



## Acapella11

michaelkeeney said:


> Hello LD crew. Thinking about pulling the trigger on a set of hifiman he560 cans, but wondering about compatabity with the LD mk iii. I've currently got some C3G's and 6SN7's in there right now, but being that the 560's are low impedance cans, I know they won't like the 6SN7's. I'd originally purchased and rolled my mk iii because I was thinking of going the Senn HD 800 route, but have since been semi redirected to the hifiman cans. My endgame amp will be a WA22, but I'm a year away from that still. Anyone have any insight into this? Thanks




Hi Michael, three ways to go with the Hifiman and beyond 6H30P/6N6P-IR power tubes: 1) 6080/6AS7G + power supply, 2) 5687 with adapter, 3) audiophile resistor cable and 6SN7.


----------



## michaelkeeney

Thanks so much. I'll poke around the web and see what is easiest. Sounds like it might be that audiophile cable with the 6sn7...

Edit: actually I think I have some 5687 and adapters already, so that might be my ticket. Thanks


----------



## gibosi

acapella11 said:


> Hi Michael, three ways to go with the Hifiman and beyond 6H30P/6N6P-IR power tubes: 1) 6080/6AS7G + power supply, 2) 5687 with adapter, 3) audiophile resistor cable and 6SN7.


 
  
 Are there any downsides to using audiophile resister cables?


----------



## TrollDragon

gibosi said:


> Are there any downsides to using audiophile resister cables?


 
 Yes, your wallet is much lighter...


----------



## gibosi

I seem to remember that you built an impedance adapter to allow the use of low-Z headphones with your LD?  Granting that pre-built cables might be costly, practically speaking, is there a downside to using an impedance adapter to allow the use of low Z headphones with OTL amps?


----------



## TrollDragon

gibosi said:


> I seem to remember that you built an impedance adapter to allow the use of low-Z headphones with your LD?  Granting that pre-built cables might be costly, practically speaking, is there a downside to using an impedance adapter to allow the use of low Z headphones with OTL amps?


 
 Sorry I was thinking of something else.. Yes the little impedance adapter does cut the volume a bit but you just turn it up a little more. For my Low Z headphones it did remove the hum I was experiencing.
  
 I was thinking about this bit of Snake Oil here...


----------



## SonicTrance

gibosi said:


> I seem to remember that you built an impedance adapter to allow the use of low-Z headphones with your LD?  Granting that pre-built cables might be costly, practically speaking, is there a downside to using an impedance adapter to allow the use of low Z headphones with OTL amps?


 
 I've used a impedance adapter with low Z cans with good results. My goal was to remove hum from the Lorenz c3g's, and it did. Not needed with the Siemens c3gs's though. Also I dont experience any distortion using 6sn7's with either my HE400i or the W1000X


----------



## michaelkeeney

You guys rock. Thanks a ton. Is there an impedance adapter you guys can recommend?


----------



## TrollDragon

michaelkeeney said:


> You guys rock. Thanks a ton. Is there an impedance adapter you guys can recommend?


 

 If you are handy with DIY, you can build your own. This one has a pair of 150Ω resistors in series with each chanel.


----------



## d4rkch1ld

Any solution on the market? I would like to use my fidelio x2 with little dot, for now sound is very bad...


----------



## mordy

_All Siemens branded ones seems to have gold pins._
  
 I have several Siemens branded C3g tubes with pins that are not gold plated.


----------



## SonicTrance

d4rkch1ld said:


> Any solution on the market? I would like to use my fidelio x2 with little dot, for now sound is very bad...


 
 I use this http://www.ebay.com/itm/300453295797?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT
 I got the 150ohm and the 300ohm version and the only difference between the two is that I have to turn the volume up further with the 300ohm adapter.


----------



## buldogge

C3G questions.
  
 So, I got my new adapter version made, using the NOS Amphenol sockets.  The sockets themselves are a lot nicer engaging the C3G pins, but I'll tell you what, soldering to the terminals was a beotch...by comparison, the Chinese "gold" spades took solder like a champ.  
  
 Anyway, the issue that I thought was the cheapo Chinese sockets, seems like maybe it is one of the C3Gs after all.  (1) tubes seems to have a short, of sorts...needs to be messed with/sittting just right.   Also, I noticed it was picking up radio signals today!?
  
 Any ideas/input???
  
 Did you guys note the german C3G auction, that Mordy pointed out, ending at 300+ Euros...will end up being a good score for someone.
  
 TIA
 -Mark in St. Louis


----------



## Acapella11

Found some more infos on resistor cables on head-fi in this thread:
  
 http://www.head-fi.org/t/601669/impedance-adapters-cables-explained-listed


----------



## michaelkeeney

acapella11 said:


> Found some more infos on resistor cables on head-fi in this thread:
> 
> http://www.head-fi.org/t/601669/impedance-adapters-cables-explained-listed




Epic. Was having trouble finding anything on the web. Probably should have just used the headfi search engine. Thanks bru.


----------



## Jolfr

So I just purchased some new tubes and have seen a few things on ebay called tube dampers. I've seen all sorts, some that look like rubber o-rings, and some that look like cylinders on a ring. Do these really help? 
 Thanks!


----------



## MIKELAP

jolfr said:


> So I just purchased some new tubes and have seen a few things on ebay called tube dampers. I've seen all sorts, some that look like rubber o-rings, and some that look like cylinders on a ring. Do these really help?
> Thanks!


 
 I have regular rubber orings that happen to fit on a pair of microphonic RCA 6SN7GT greyglass i have and what i say to you is dont spend your money on overpriced orings because they are just that doesnt work for me .


----------



## TrollDragon

jolfr said:


> So I just purchased some new tubes and have seen a few things on ebay called tube dampers. I've seen all sorts, some that look like rubber o-rings, and some that look like cylinders on a ring. Do these really help?
> Thanks!


 

 I find that they really add a nice aesthetic and help with the separation.


Spoiler: ...



Of you from your money and that's all.


----------



## i luvmusic 2

I managed to squeezed in the ALPS BLUE into my MK III,again the sound improvement is noticeable quiet background and sounds very clear.


----------



## buldogge

^^^Did you have to make a spacer for the faceplate?

I installed the eBay DACT 21 in the MKIII tonight...all fixed now...sounds good. 

Now we'll see if I can break it, after the Mundorf caps arrive from Germany (Russian PIOs sitting here now)...

-Mark in St. Louis


----------



## i luvmusic 2

buldogge said:


> ^^^Did you have to make a spacer for the faceplate?
> 
> I installed the eBay DACT 21 in the MKIII tonight...all fixed now...sounds good.
> 
> ...


 
 Yes and i in-large the existing POT hole big enough to put the Alps flash to the faceplate.I will post some pics sometime this week,I'am enjoying it that is why i don't want to take it apart again.Did you noticed how quiet the background and to my ears everything sounds smooth and quiet/clear and the soundstage sounds like it gets bigger at least to my ears.
  
 I'am one of those MUNDORF whore.


----------



## buldogge

^^^ 
	

	
	
		
		

		
		
	


	




  Wow...
  
 Is there a write up on that build anywhere???
  
 -Mark


----------



## i luvmusic 2

Here's what i did to install the  ALPS into the MK III.

 Shaved off some PCB materials.

  

  

 In large the existing Pot hole.
  


 Removed the Back cover of the ALPS.

  

 Pieces needed for installation 1 large washer and the ALPS hardware.

 Bend all the ALPS solder Lugs flat and solder all the connections.

 Installed the POT onto the Faceplate.


----------



## gibosi

A Tung-Sol 6F8G with flat ladder plates arrived today. So far I have seen three different versions of the TS 6F8G, one with round plates, one with Sylvania-style T-plates plates and one with RCA-style flat ladder plates. And there might be other versions out there that I have't seen.
  
 From this photograph, it is easy to see that the rather rare TS 6SN7GT with flat ladder plates and a square top mica I picked up recently is essentially a TS 6F8G stuffed into a 6SN7 bottle.


----------



## Acapella11

Today a pair of Westinghouse 6SN7 GTB from 1966 arrived (round getter, white mica, grey plate) and burn in. So far, very pleasant sound, good resolution and bass. Used as power tubes with C3GS as driver.


----------



## MIKELAP

Got my adapters from Glenn today to use with the 6F8G tubes ,were a long way from stock i would say


----------



## jaywillin

love the glow !


----------



## buldogge

OK...This is getting a little annoying.
  
 Two questions:
  
 1) Is anyone else picking up radio signals with their C3Gs???
  
 2) Have you found that the C3Gs need more gain (volume pot position) than EF95 or EF91/92 tubes on the same track?
  
 TIA
 -Mark in St. Louis


----------



## adtrance

i luvmusic 2 said:


> Here's what i did to install the  ALPS into the MK III.


 
 Absolutely superb!!!  This is the sort of treasure you come across here.  Thank you!!


----------



## gibosi

buldogge said:


> OK...This is getting a little annoying.
> 
> 1) Is anyone else picking up radio signals with their C3Gs???


 
  
 I do not pick up any radio signals with the C3gs. And the flying wires and extra test sockets in my configuration is likely more prone to stray rf than most.


----------



## MIKELAP

buldogge said:


> OK...This is getting a little annoying.
> 
> Two questions:
> 
> ...


 
  
 Nope no problem here with radio signals and C3G'S ,as for question 2 i just tried  some 6DT6A RCA tubes with 6F8G as power tubes and for equal volume the C3g's are louder and sound way better by the way .


----------



## buldogge

^^^I think one of the C3Gs is "bad", somehow...maybe some kind of short...Doesn't happen with any other tube.  I emailed the German seller...I don't get the feeling he is gonna be very helpful, based on the last time I emailed him.
  
 Does anyone have a single/stray C3G they want to part with???..or I'll buy a pair, if they prefer/need me to.
  
 TIA
 -Mark


----------



## SonicTrance

adtrance said:


> Absolutely superb!!!  This is the sort of treasure you come across here.  Thank you!!




I agree. Nice upgrade!


----------



## i luvmusic 2

THANKS!


----------



## buldogge

Hey Guys...I have  a slightly OT/side-topic question...
  
 I'm picking up a Music Hall 25.3 DAC for a great price and I'm gonna pair it with the MKIII.  It uses a single 6922/6DJ8/7308 for the output stage thru RCAs.  It also has XLR outputs (which are not true balanced) which bypass the tube (are SS).
  
 So, I could run XLR to RCA cables and bypass the 6922...or...RCAs thru a single 6922 family.
  
 What is a good/cheap/reasonable neutral 6922?  (assume neutral on a DAC would be wise)
  
 Should I leave the coloration/tuning to the LD tube rolling and run out of the XLRs??
  
 Thoughts???
  
 TIA
 -Mark in St. Louis
  
_ps...Still looking for a C3G (or 2) if anyone has any spares!_


----------



## hypnos1

buldogge said:


> Hey Guys...I have  a slightly OT/side-topic question...
> 
> I'm picking up a Music Hall 25.3 DAC for a great price and I'm gonna pair it with the MKIII.  It uses a single 6922/6DJ8/7308 for the output stage thru RCAs.  It also has XLR outputs (which are not true balanced) which bypass the tube (are SS).
> 
> ...


 
 Hi buldogge.
  
 I think I have one out of its shell and permanently adapted for use just in the LD - ie silver wires attached directly to the pins and all sealed in resin, so would look different to your other put in an adapter...if any good to you just PM me...


----------



## superdux

buldogge said:


> _ps...Still looking for a C3G (or 2) if anyone has any spares!_


 
  
 These C3G are going cheap, but hurry there are only 6 left:

 Auction Nr.261797955911


----------



## WilliamLeonhart

Slightly off-topic but guys I need to learn something:
  
 http://en.wikipedia.org/wiki/6AK5
  
 From this article I figure that tubes with identical design but from manufacturers will have different designation? 
  
 My LD I+ came with 6cq6 tubes, but it has "EF92" written on the boxxes. What does it mean?


----------



## gibosi

williamleonhart said:


> Slightly off-topic but guys I need to learn something:
> 
> http://en.wikipedia.org/wiki/6AK5
> 
> ...


 
  
 Yes, identical tubes can have different designations. Generally, 6AK5 is the American designation, EF95 is the European designation, and 5654 is the industrial/military designation. The 6AK5 and EF95 were consumer-grade tubes, while 6AK5W and 5654 were more rugged, providing a longer lifetime, which was obviously important for industrial/military uses.
  
 The Radio Museum web site provides more information on all the different versions.
  
 http://www.radiomuseum.org/tubes/tube_6ak5.html
  
 And similarly, 6CQ6 is the American designation and EF92 is the European designation:
  
 http://www.radiomuseum.org/tubes/tube_6cq6.html


----------



## WilliamLeonhart

So I figure that "6CQ6" and "EF92" will have the same sound characteristics? 
 Or is it that the same tubes manufactured by different companies will have different sound? I'm leaning towards the 2nd theory. The "identical"-ness that we're talking about is just in terms of gains, I suppose?


----------



## Rayzilla

Sorry if I am asking a noob question here but I do not know much about tubes let alone rolling them. I recently picked up an old used Little Dot II. I have been trying to find information about it, specifically the tube types that go with it. The unit that I picked up has very old tubes on it. It even looks like some of the pins inside of the tubes are snapped/disconnected.
  
 I am now living in Hong Kong, so if I can find some cheap tubes here to use on the Little Dot II, I will give it a shot. Otherwise I will be going back for the summer in Toronto this year.
  
 The sound that I would like to change from the current, I assume stock tubes, is less warm, more transparent, and more bass would be good.
  
 Whenever I do a search, most of the information that pops up is for Little Dot MKII, which I believe is newer and better. I did come across this information from an ebay website. Is it the right information?
  
The Little Dot II has sharp, dynamic range. Low sounds are really low and highs are really loud. Bass and sound stage wasn't good at first but after 100 hrs the warm bass came through beautifully and sound stage widened incredibly. Voice is super realistic, with more body. I'm using this amp with my PC tower,  DAC and Sennheiser HD 650. Tube Upgrade​ Look for Mullard 8100 drivers tubes if you ordered stock. 
 Power Tubes 6H30Pi 6N1P 
 Driver Tubes Russian 6zh1P Tung-sol 403b Sylvania black plate 6AK5W (or WB) Mullard 8100 Solid Sate upgrade​ *NONE REQUIRED* 
  
Tube Rolling​   * *
(403A, 403b, 408a, 408b, 415A, 5654, 5591, CV4010, CV5216, CV8246, 6069, CV10442, EF95 , M8100, 6AK5, CV10100, CV8159, CV8225, CV850, 6J1, EF92, 6CQ6, CV2023, V884, VP6, M8161, CV131, 9D6, W77)


----------



## gibosi

williamleonhart said:


> So I figure that "6CQ6" and "EF92" will have the same sound characteristics?
> Or is it that the same tubes manufactured by different companies will have different sound? I'm leaning towards the 2nd theory. The "identical"-ness that we're talking about is just in terms of gains, I suppose?


 
  
 They have the same "electrical" characteristics. However, tubes manufactured in different factories at different times often sound different.


----------



## Oskari

Also identical tubes made at the same factory can carry different designations based on the market they were destined for.


----------



## Oskari

> Originally Posted by *gibosi* /img/forum/go_quote.gif
> 
> 5654 is the industrial/military designation.


 
  
 You can add "American" there. The systematic Euroname of an improved type is E95F.


----------



## Acapella11

rayzilla said:


> Sorry if I am asking a noob question here but I do not know much about tubes let alone rolling them. I recently picked up an old used Little Dot II. I have been trying to find information about it, specifically the tube types that go with it. The unit that I picked up has very old tubes on it. It even looks like some of the pins inside of the tubes are snapped/disconnected.
> 
> I am now living in Hong Kong, so if I can find some cheap tubes here to use on the Little Dot II, I will give it a shot. Otherwise I will be going back for the summer in Toronto this year.
> 
> ...


 
  
 You could read through the thread and look at the table page 585. However, in short the answer is: Ignore ebay infos and for direct replacement, get a pair of 6N6P-IR as power tubes and Yugoslavian Ei tall bottle 6HM5 driver tubes. After that, there are more options via adapters. You could also buy a pair of adapters as indicated in the table and get yourself a pair of 6SN7 as power tubes. Those would probably surpass the 6n6P-IRs.


----------



## TrollDragon

What tubes are in the old LD II now? If it is one of the first ones, then most of the tubes we use will not work at all. You might have trouble finding replacements for the ones you have.


----------



## WilliamLeonhart

gibosi said:


> They have the same "electrical" characteristics. However, tubes manufactured in different factories at different times often sound different.


 
  


oskari said:


> Also identical tubes made at the same factory can carry different designations based on the market they were destined for.


 
 Great. Thanks for the clarifications.


----------



## Jolfr

So I took Mordy's advice and decided to get some 6SN7 tubes for my Mk iii. I purchased some extenders and adapters (9-pin to 8 pin) and I wanted to show off the adapters I got.
 I purchased these:
 http://www.ebay.com/itm/191186398466?_trksid=p2060778.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT
 The covering is real brass(which looks really nice), and they have a grounding wire (I don't know how useful this actually is). They are only a couple bucks more expensive than any other adapters I've seen.
 Here's the kicker though. The pins are really long! When I plugged them into the adapter I noticed quite a bit of space left in between the adapter and the extender.
 Turns out they fit into the socket by themselves so no adapters are needed! This means that they end up being cheaper and look nicer.
  
 what do you guys think?


----------



## mordy

Hi Jolfr,
  
 Thanks for sharing with us the information about these adapters. The only reason to use the extenders is because the other style adapter is too wide to fit inside the decorative ring on the MKIII amp. In addition, these look better with the brass covering.
  
 Now, how do you find the sound of the 6SN7 tubes compared to your old power tubes? In my experience the 6SN7 tubes have more bass and add more overall to improve the sound than the 6N6P family of tubes. You can also try 6SL7 tubes that give a little lighter and more airy presentation.
  
 For the ultimate slam and impact in the bass, and an overall richer and fuller sound, you would have to upgrade to 2.5A power tubes such as the 6AS7/6080. (Needs external 15A power supply and 15A voltage regulator.)


----------



## SonicTrance

mordy said:


> Hi Jolfr,
> 
> Thanks for sharing with us the information about these adapters. The only reason to use the extenders is because the other style adapter is too wide to fit inside the decorative ring on the MKIII amp. In addition, these look better with the brass covering.
> 
> ...


 
 Hi Mordy,
  
 Why would you need a 15A psu to run 2.5A tubes? Doesn't make sense to me. I just got my 6H5C's in my MK IVSE. I'm running two 6V 6A psu's, one for each tube, no regulator. Tubes are burning in now, literally just got them in Will come back with impressions.


----------



## mordy

Hi MisterX,
  
 We are really pretty much on the same page, LOL.
  
 You are using two power supplies, each 6A = 12A. I am using one PS rated 15A. I have been told that when the tubes start up, they can draw up to three times the current, hence 2.5AX3 = 7.5A per tube. One PS for two tubes would need 15A. I used a 430W computer PC power supply that I had saved as a spare, and it was rated 14-15A, so pretty much within what I wanted.
  
 The PC PS puts out 12V and 5V, and that is why I bought a 15A voltage regulator to connect it to the 12V rails and then I adjust it to 6.3V. Both tubes are driven by one PS and one voltage regulator.
  
 Based on experience, there is a voltage drop at the actual tube pins compared to the measured voltage at the voltage regulator, so in practice I need something like 6.9V at the regulator to get a reading of 6.3V at the tube pins (Varies with tubes). You may want to measure the actual voltage at the tube pins to see if you get a full 6.3V there.
  
 The PS cost $30 on sale (usually $60), and the voltage regulator around $12.
  
 Lycka till med allting!


----------



## Jolfr

mordy said:


> Hi Jolfr,
> 
> Thanks for sharing with us the information about these adapters. The only reason to use the extenders is because the other style adapter is too wide to fit inside the decorative ring on the MKIII amp. In addition, these look better with the brass covering.
> 
> ...


 
 I definitely noticed that the sound was much more full! And yes, I would say it's definite upgrade from the 6N6P.


----------



## gibosi

As some might remember, I have been thinking for over a year about moving beyond my LD 1+ to a 6AS7G-based OTL. Of particular importance to me was being able to use all my favorite tubes in my new amp. Today, I took delivery of a Glenn OTL. Of particular note, this amp can use either a pair of G3gs or any SN7 (6SN7, 12SN7 or 25SN7). I am not aware of any other 6AS7-based OTL that is designed from the ground up to use a pair of C3gs as drivers as well as SN7s.
  
 Pictured, with a 3DG4 rectifier, Ken-Rad 1633 (25SN7) and two Chatham 6AS7s. And yes, it sounds much better than my LD 1+!
  

  
 In fairness, we need to remember that our LDs were designed to use triode-strapped 6AK5s, not 6SN7s or any other double-triode, and certainly not a pair of C3gs. For sure, these tubes sound great in our LDs, much better than any 6AK5, but since the biasing is not optimal for these tubes, they cannot sound as good as they do in an amp that has been carefully and deliberately designed to use these tubes.
  
 And now please excuse me as I return to the music.


----------



## jaywillin

gibosi said:


> As some might remember, I have been thinking for over a year about moving beyond my LD 1+ to a 6AS7G-based OTL. Of particular importance to me was being able to use all my favorite tubes in my new amp. Today, I took delivery of a Glenn OTL. Of particular note, this amp can use either a pair of G3gs or any SN7 (6SN7, 12SN7 or 25SN7). I am not aware of any other 6AS7-based OTL that is designed from the ground up to use a pair of C3gs as drivers as well as SN7s.
> 
> Pictured, with a 3DG4 rectifier, Ken-Rad 1633 (25SN7) and two Chatham 6AS7s. And yes, it sounds much better than my LD 1+!
> 
> ...


 
 very nice indeed !


----------



## SonicTrance

mordy said:


> Hi MisterX,
> 
> We are really pretty much on the same page, LOL.
> 
> ...




Hm, I totally forgot about the startup draw, I've also read that somewhere. I'm pretty sure I'm not getting 6.3 volts at the pins since the psu is rated at 6.0v but i figured it's close enough, lol. 

Tackar!


----------



## i luvmusic 2

gibosi said:


> As some might remember, I have been thinking for over a year about moving beyond my LD 1+ to a 6AS7G-based OTL. Of particular importance to me was being able to use all my favorite tubes in my new amp. Today, I took delivery of a Glenn OTL. Of particular note, this amp can use either a pair of G3gs or any SN7 (6SN7, 12SN7 or 25SN7). I am not aware of any other 6AS7-based OTL that is designed from the ground up to use a pair of C3gs as drivers as well as SN7s.
> 
> Pictured, with a 3DG4 rectifier, Ken-Rad 1633 (25SN7) and two Chatham 6AS7s. And yes, it sounds much better than my LD 1+!
> 
> ...


 
 Congrats!


----------



## Acapella11

gibosi said:


> As some might remember, I have been thinking for over a year about moving beyond my LD 1+ to a 6AS7G-based OTL. Of particular importance to me was being able to use all my favorite tubes in my new amp. Today, I took delivery of a Glenn OTL. Of particular note, this amp can use either a pair of G3gs or any SN7 (6SN7, 12SN7 or 25SN7). I am not aware of any other 6AS7-based OTL that is designed from the ground up to use a pair of C3gs as drivers as well as SN7s.
> 
> Pictured, with a 3DG4 rectifier, Ken-Rad 1633 (25SN7) and two Chatham 6AS7s. And yes, it sounds much better than my LD 1+!
> 
> ...


 
  
 Great, you got it after all the looking forward. Now you need a few amps next to it to compare  Enjoy!


----------



## mordy

Hi Gibosi,
  
 Congratulations on your new Glenn amp! It seems like you were waiting almost a year to get it....
  
 Awaiting your listening impressions - wonder which combination of tubes sounds the best. Probably will take some time given all the possibilities and all the different tubes you have collected. Perhaps a combination of C3g and 6AS7 tubes will sound the best, but maybe we will be in for some surprises.
  
 Good luck and enjoy your new amp!


----------



## mordy

Hi Mister X,
  
 If you have a voltmeter you could just touch the pins 4&5 and measure the voltage at the tube. Should be possible if the pins on the adapter are long enough. Just be careful to touch the right pins.
  
 (Jag vaxte up i Sverige och talar fortfarande svenska efter 47 ar i Amerika.)


----------



## TrollDragon

gibosi said:


> As some might remember, I have been thinking for over a year about moving beyond my LD 1+ to a 6AS7G-based OTL. Of particular importance to me was being able to use all my favorite tubes in my new amp. Today, I took delivery of a Glenn OTL. Of particular note, this amp can use either a pair of G3gs or any SN7 (6SN7, 12SN7 or 25SN7). I am not aware of any other 6AS7-based OTL that is designed from the ground up to use a pair of C3gs as drivers as well as SN7s.
> 
> Pictured, with a 3DG4 rectifier, Ken-Rad 1633 (25SN7) and two Chatham 6AS7s. And yes, it sounds much better than my LD 1+!
> 
> ...


 
  
 Hmmmm... That sounds very similar to something I said a long while ago...


----------



## gibosi

acapella11 said:


> Great, you got it after all the looking forward. Now you need a few amps next to it to compare  Enjoy!


 
  
 If you mean I should start collecting amps, I don't think so.... lol 
  
 But of course, it would be great fun to go to meets and be able to compare it Woos and others....


----------



## gibosi

trolldragon said:


> Hmmmm... That sounds very similar to something I said a long while ago...


 
  
 Yes, I remember... 
  
 However, the fact remains that even an average double triode sounds better than any 6AK5 in our LDs. Using crude pin-adapters and external power supplies, we have taken our LDs to heights beyond our wildest dreams.
  
 And in my case, I have been adapting and trialing all these tubes with the understanding that they were an investment. I wasn't sure exactly what amp I would get, but I knew that eventually I would purchase an amp that would do these wonderful tubes justice. And it finally happened.
  
 So it seems to me that one can adapt their LDs to use double triodes, C3gs and even 6AS7s. And the end result is indeed very good. And it just might be good enough. But if not, there are other amps than can reveal the true potential of these tubes.
  
 Speaking of tubes, I have a couple of ECC808s coming, one a Valvo manufactured in Hamburg, and the other a Telefunken. These are closer to a 12AX7 than a 6SN7, so I will be trialing these in the my LD.  The LD 1+ lives on...


----------



## SonicTrance

gibosi said:


> As some might remember, I have been thinking for over a year about moving beyond my LD 1+ to a 6AS7G-based OTL. Of particular importance to me was being able to use all my favorite tubes in my new amp. Today, I took delivery of a Glenn OTL. Of particular note, this amp can use either a pair of G3gs or any SN7 (6SN7, 12SN7 or 25SN7). I am not aware of any other 6AS7-based OTL that is designed from the ground up to use a pair of C3gs as drivers as well as SN7s.
> 
> Pictured, with a 3DG4 rectifier, Ken-Rad 1633 (25SN7) and two Chatham 6AS7s. And yes, it sounds much better than my LD 1+!
> 
> ...


 
 Congrats on the new amp! Looks great and I bet it sounds great as well
	

	
	
		
		

		
			





  
  


mordy said:


> Hi Mister X,
> 
> If you have a voltmeter you could just touch the pins 4&5 and measure the voltage at the tube. Should be possible if the pins on the adapter are long enough. Just be careful to touch the right pins.
> 
> (Jag vaxte up i Sverige och talar fortfarande svenska efter 47 ar i Amerika.)


 
 That would be a real hassle cause I've cut of pin 4 and 5 on the adapters and soldered the psu cables to the cut of pins.
 Here's what it looks like:
  

  

  
 I've only had the chance to listen to these 6H5C's for a couple of hours but I do notice a big difference compared to the the 6SN7's. Bass is punchier and deeper and no background noise. No need for any impedance adapter with low Z cans with these power tubes. This makes me want to upgrade to an MK9, lol. But then I couldn't use the lovely C3Gs...


----------



## mordy

Hi Mister X,
  
 Your setup looks really nice - enjoy!  I use the C3gS as drivers, and a pair of 1960's Sylvania 6080 tubes as power tubes with great sound. Although I tried several other power tubes, including RCA 6AS7, Chatham 6AS7, and GE, RCA, Phillips and Sylvania Gold 6080s, I prefer the 1960 Sylvanias. Have yet to find somebody who corroborates my preference.....


----------



## Peter_S

Hi guys. I'm seeking some advice. My amplifier is making crackling and static sounds. I read the manual, and will clean all the contacts for the tubes. Other any other steps I should do to identify and address the source of this problem, I have different output tubes but I don't have a different power tube. I may have to get one to try to identify the issue.

I am using it as a preamp for a Trends audio 10.2 amplifier. I will also check to see if the crackling sound occurs with headphones.


----------



## buldogge

Which amplifier?

 Is the sound from a single channel, or both?

 Does the noise move channels when you swap tubes?
  
 I just went thru this with my MK III...ended up having to switch out the volume pot.
  
 BTW...The output, both HP jack and pre-outs goes thru the pot...FWIW.
  
 -Mark in St. Louis
  
 Quote:


peter_s said:


> Hi guys. I'm seeking some advice. My amplifier is making crackling and static sounds. I read the manual, and will clean all the contacts for the tubes. Other any other steps I should do to identify and address the source of this problem, I have different output tubes but I don't have a different power tube. I may have to get one to try to identify the issue.
> 
> I am using it as a preamp for a Trends audio 10.2 amplifier. I will also check to see if the crackling sound occurs with headphones.


----------



## SonicTrance

mordy said:


> Hi Mister X,
> 
> Your setup looks really nice - enjoy!  I use the C3gS as drivers, and a pair of 1960's Sylvania 6080 tubes as power tubes with great sound. Although I tried several other power tubes, including RCA 6AS7, Chatham 6AS7, and GE, RCA, Phillips and Sylvania Gold 6080s, I prefer the 1960 Sylvanias. Have yet to find somebody who corroborates my preference.....


 
 Hi Mordy,
  
 I'm enjoying it alright
	

	
	
		
		

		
		
	


	




 I have a pair of those chinese Shuguang 6N13P-T on the way for me to try next. I've looked at 6080's but they're mostly available from the states and that means extra custom/import charges. None of that from China.


----------



## Jolfr

So I received my ei 6hm5's today, and I wanted to check before I power anything on. Do I need to switch the jumpers from where they were for the stock tubes?
 So if I'm looking at the jumpers from the bottom of the amp with the headphone jack pointed towards me, should the jumpers be to the right or to the left?
 Thanks once again!


----------



## SonicTrance

jolfr said:


> So I received my ei 6hm5's today, and I wanted to check before I power anything on. Do I need to switch the jumpers from where they were for the stock tubes?
> So if I'm looking at the jumpers from the bottom of the amp with the headphone jack pointed towards me, should the jumpers be to the right or to the left?
> Thanks once again!


 
 The jumper needs to cover pin 1 & 2 for EF95 type tubes. Don't have the mk3 myself but i guess the pins are numbered?


----------



## buldogge

jolfr said:


> So I received my ei 6hm5's today, and I wanted to check before I power anything on. Do I need to switch the jumpers from where they were for the stock tubes?
> So if I'm looking at the jumpers from the bottom of the amp with the headphone jack pointed towards me, should the jumpers be to the right or to the left?
> Thanks once again!


 

 EF95 setting...
  
 MK III?  Jumpers on the left when looking at the board/bottom.
  
 MK II?  No jumpers/jumpers removed.
  
 -Mark in St. Louis


----------



## Jolfr

Thanks guys!


----------



## MIKELAP

jolfr said:


> So I received my ei 6hm5's today, and I wanted to check before I power anything on. Do I need to switch the jumpers from where they were for the stock tubes?
> So if I'm looking at the jumpers from the bottom of the amp with the headphone jack pointed towards me, should the jumpers be to the right or to the left?
> Thanks once again!


 
 Looking under the MK3 amp arrow pointing to front


----------



## i luvmusic 2

.


----------



## Rayzilla

acapella11 said:


> You could read through the thread and look at the table page 585. However, in short the answer is: Ignore ebay infos and for direct replacement, get a pair of 6N6P-IR as power tubes and Yugoslavian Ei tall bottle 6HM5 driver tubes. After that, there are more options via adapters. You could also buy a pair of adapters as indicated in the table and get yourself a pair of 6SN7 as power tubes. Those would probably surpass the 6n6P-IRs.




Thanks for this information. I will try to Take a look at it in more detail when I get the chance and after I confirm on the issue raised by TrollDragon. 


trolldragon said:


> What tubes are in the old LD II now? If it is one of the first ones, then most of the tubes we use will not work at all. You might have trouble finding replacements for the ones you have.



I bought it used so I do not know how old or whether it is one of the first ones or not. Is there any particular way to confirm? This sounds discouraging.


----------



## TrollDragon

rayzilla said:


> I bought it used so I do not know how old or whether it is one of the first ones or not. Is there any particular way to confirm? This sounds discouraging.


 
 What are the numbers on the tubes you have in the amp now?
 We can tell you what should work and what wont if we know what those are.


----------



## TrollDragon

You have Line Magnetic gear...
 What on earth are you doing playing with an old Little Dot?  
	

	
	
		
		

		
			




  
 The 219ia would be my dream amplifier for sure, because no one can afford a pair of LM-1's.


----------



## Rayzilla

trolldragon said:


> What are the numbers on the tubes you have in the amp now?
> 
> We can tell you what should work and what wont if we know what those are.








Hopefully the pics have uploaded properly. Does it help? I am not near my LD button I took these pictures just the other day.


----------



## Rayzilla

trolldragon said:


> You have Line Magnetic gear...
> What on earth are you doing playing with an old Little Dot?
> 
> 
> ...


 





 The LM amp and separate dac was my first and only desktop rig so I have no idea how to evaluate it. So I didn't know whether it is good/bad/whatever because I had nothing to compare with it. I love trying different things, especially if affordable.
  
 And I wanted to get an amp to use at work so I just wanted to pick up anything cheap and the LD II came up in a local ad so I went for it. Hopefully there will be some good news on the tube rolling options. Anything cheap will do and if it can be easily purchased from here ...


----------



## Acapella11

This is taken from a 2010 MKII reference guide:
 Little Dot MK II
 Switches for Driver Tube
 -
 Rolling The Little Dot MK II has two switches or two sets of jumper pins (depending on your circuit version) that allow two different types of driver tubes. You can access the switches /jumper pins through the amplifier’s bottom panel, and they are located to the sides of the pair of capacitors closest to the front of the amplifier. Please power off the amplifier, and unplug it for at least 10 minutes before attempting to change the switch /jumper settings.
  
*Driver Tubes*
  
 For Switches: If the switches are not toward the E92 label the following driver tubes may be used:
  WE403A
  5654, CK5654, GL5654, 5591, CV4010, CV5216, CV8246, 6069, CV10442
  EF95F, M8100, 6AK5W, CV10100, CV8159,CV8225, CV850
  6J1
 If the switches are on the side of the E92 label, the following driver tubes may be used:
  EF92, 6CQ6, CV2023, V884, VP6, M8161
  EF91, 6AM6, CV10327, CV138, CV1955, CV2195, Z77
  CV131, 9D6, W77
 For Jumper Pins:
 2
 - pin sets: If the jumper caps are removed, you can use the 5654/6JI driver tubes (default). If the jumper
 caps are placed over the pins, you can use EF92 type driver tubes.
 3
 - pin sets: Place the jumper cap over the middle pin and the pin to the side of the “E95” text to use the
 default 6JI/5654 tubes. Place the jumper cap over the middle pin and the pin to the side of the E92 text to
 use EF92 type tubes.
  
 Any other equivalents or drop-in replacements for the above - mentioned tubes (both sets) may also be used.
  
*Power Tubes*
  
 The Little Dot MK II uses 6n6 power tubes by default, and these can be replaced with 6H6PI,6H6n, 6H6n-N, 6N6P, and 6N6P-I power tubes.
 If your circuit version is 2.0 or above, you can also use the 6H30 type power tubes (6H30EB, 6H30PI, 6H30P-DR, etc).
  
 Here is the link to the most current reference guide: https://dl.dropboxusercontent.com/u/6037680/Little%20Dot%20MK%20II%20Reference%20Guide.pdf
  
 The 6N6P-IR are direct replacements for MKII power tubes.
 However, the power tubes you are having there don't look to me like Russian 6N6P tubes at all. Your's have a flat top like 6SN7 tubes, not the "helmet" type one like 6N6P. See also here the original configuration: http://www.littledot.net/forum/viewtopic.php?f=9&t=816&sid=4c64bb54fd31ff4d2317c7030f11bd95
  
 If you could please could provide photos which capture the actual logos crisply? Btw., don't worry to take the tubes out. Just pull out your headphones before doing so. Switching off the amp is optional, lol, have I just said that? Shhh.


----------



## gibosi

rayzilla said:


> Hopefully the pics have uploaded properly. Does it help? I am not near my LD button I took these pictures just the other day.


 
  
 Your LD appears to be quite old, perhaps as old as 10 years, and it does not use the same tubes as the current version. My best guess is that the amp uses 1B2 for the driver and 4P1S for output. However, I would suggest that you contact Little Dot directly, along with the pictures you have posted here, to have them verify this. They can be reached at little.tube@gmail.com.


----------



## gibosi

As this is the Little Dot rolling thread, and not the Glenn OTL thread, I won't be posting very often about the Glenn, but I thought a few of my initial impressions as to how it compares with my Little "Monster" Dot 1+ might be of interest to some.
  
 In recent weeks, a US-made Philips E182CC and a grey-glass NU 6SN7 spent the most time in my LD, so I was very eager to see how these tubes sounded in the Glenn. I am pleased to report that that they retain their basic sonic signature. Rolling them in to the Glenn, they sound very familiar, like old and dear friends, and yet a little different.
  
 The first thing I noticed was the bass. Mordy and others have commented about the bass slam and power resulting from rolling 6AS7s in their LDs. As my 1+ has solid state output, not tubes, I was very curious how the bass would compare. The Chatham 6AS7s (the only output tube I have tried so far) in the Glenn provide a much better bass -- more authority, more power and yet more detail -- than the 1+, likely similar to the way this tube sounds in an LD III or IV. Better, much better. 
  
 Something else I think I am noticing... Differences in clarity, micro-details - resolution - if you will. Glenn gave me a Ken-Rad 1633, essentially a 25V 6SN7, so I started with that tube. Replacing it with a pair of C3gs was like a veil being lifted. Micro details became sharper and more clear. In the LD, while this difference was noticeable, it was more subtle.
  
 In a similar way, the resolution of the E182CC is superior to the NU 6SN7. However, the differences in resolution are still quite small, and the NU's other strengths more than offset. As I write this I am thoroughly enjoying Leslie Feist's 2004 album _Let It Die_ through the NU. Her voice has a tendency to sound a little "reedy" at times, and with some tubes, this can be a little grating. But the wonderfully smooth and liquid mid range of the NU allows her voice to shine.
  
 Suffice it to say, the Glenn is everything I hoped it would be... and more.


----------



## SonicTrance

gibosi said:


> As this is the Little Dot rolling thread, and not the Glenn OTL thread, I won't be posting very often about the Glenn, but I thought a few of my initial impressions as to how it compares with my Little "Monster" Dot 1+ might be of interest to some.
> 
> In recent weeks, a US-made Philips E182CC and a grey-glass NU 6SN7 spent the most time in my LD, so I was very eager to see how these tubes sounded in the Glenn. I am pleased to report that that they retain their basic sonic signature. Rolling them in to the Glenn, they sound very familiar, like old and dear friends, and yet a little different.
> 
> ...




Interesting to hear that the 6SN7 sounded about the same in your Glenn, wich is made to run those tubes, as it did in your LD. Though the c3gs sounded better in the Glenn?
Anyway, it sounds like you're real happy with your new amp!


----------



## gibosi

sonictrance said:


> Interesting to hear that the 6SN7 sounded about the same in your Glenn, wich is made to run those tubes, as it did in your LD. Though the c3gs sounded better in the Glenn?
> Anyway, it sounds like you're real happy with your new amp!


 
  
 The four driver tubes I have tried, including the C3g, retain their same basic sonic signature, but sound even better, with the differences noted above. And this is very reassuring, as I think I can expect that some of my other favorites, like the short-bottle Sylvania 6SN7W, will also sound familiar, but better. 
  
 Edit: And so I think you can take from this that even though the LDs are not designed to run C3gs, 6SN7s and other medium mu double triodes, they still sound very good and it is very likely that your favorites with the LD will continue to be your favorites with a better amp.


----------



## SonicTrance

gibosi said:


> The four driver tubes I have tried, including the C3g, retain their same basic sonic signature, but sound even better, with the differences noted above. And this is very reassuring, as I think I can expect that some of my other favorites, like the short-bottle Sylvania 6SN7W, will also sound familiar, but better.
> 
> Edit: And so I think you can take from this that even though the LDs are not designed to run C3gs, 6SN7s and other medium mu double triodes, they still sound very good and it is very likely that your favorites with the LD will continue to be your favorites with a better amp.




That's good to know, thanks


----------



## buldogge

Today I paired the C3Gs (now with ground wires from my adapters to behind the MK III front plate) with NU (neither labeled as such) Black Glass 6SN7GTs...
  
 Very nice, and I seem to have gotten some of my gain back.
  
 The combo seems to offer a nice balance of clarity (C3G) with added warmth/lush character (NUs)...at least to my amateur ears.
  
 Trying to decide now whether to even mess with finding older VT-231s, for the power position!???
  
 -Mark in St. Louis


----------



## buldogge

Couldn't help myself and bought some Ken Rad staggered plates...paid more than I like to (cheap git), but oh well...done with 6SN7s (for now, at least).
  
 OT: Anyone have a distinct preference for coupling caps in the LD MK III...The mod thread is dead, it seems.  I was considering Auricaps or Jantzen Z-Superiors @ about the same cost...Also, less so, Russian K42 PIOs.
  
 Any thoughts on this, at all?
  
 TIA
 -Mark


----------



## TrollDragon

buldogge said:


> Couldn't help myself and bought some Ken Rad staggered plates...paid more than I like to (cheap git), but oh well...done with 6SN7s (for now, at least).
> 
> OT: Anyone have a distinct preference for coupling caps in the LD MK III...The mod thread is dead, it seems.  I was considering Auricaps or Jantzen Z-Superiors @ about the same cost...Also, less so, Russian K42 PIOs.
> 
> ...


 
  
Duelund's or Jupiter's are the preferred choice, just ask ILM2. He partially ventured down that Rabbit Hole with his BH Crack.


----------



## buldogge

Umm...No.  
	

	
	
		
		

		
		
	


	



  
 Little too rich for my Little Dot blood.
  
 Any real world suggestions for a $300 amp??? (keeping in mind space constraints, as well)
  
 -Mark
  
 Quote:


trolldragon said:


> Duelund's or Jupiter's are the preferred choice, just ask ILM2. He partially ventured down that Rabbit Hole with his BH Crack.


----------



## i luvmusic 2

buldogge said:


> Umm...No.
> 
> 
> 
> ...


 
 SOLEN or those RUSSIANS.Boutique CAPS are more for a Bragging rights(at least for me)the difference are subtle and those film caps Takes forever to Burn-in,Yes they do get better overtime.


----------



## buldogge

Worth changing the WIMA MKPs out for Solens or PIOs, in your opinion???
  
 -Mark
  
 Quote:


i luvmusic 2 said:


> SOLEN or those RUSSIANS.Boutique CAPS are more for a Bragging rights(at least for me)the difference are subtle and those film caps Takes forever to Burn-in,Yes they do get better overtime.


----------



## i luvmusic 2

trolldragon said:


> buldogge said:
> 
> 
> > Couldn't help myself and bought some Ken Rad staggered plates...paid more than I like to (cheap git), but oh well...done with 6SN7s (for now, at least).
> ...


 
 Nice one TD.........


----------



## i luvmusic 2

buldogge said:


> Worth changing the WIMA MKPs out for Solens or PIOs, in your opinion???
> 
> -Mark
> 
> ...


 
 Those WIMA are nice i would not bother unless you want to change the stock sound,CAPS are more like tubes they do have different sound characteristics.Your ears are different from mine so what sound good for me might not be for you.


----------



## buldogge

i luvmusic 2 said:


> Those WIMA are nice i would not bother unless you want to change the stock sound,CAPS are more like tubes they do have different sound characteristics.Your ears are different from mine so what sound good for me might not be for you.


 

 I'll hold off for a little while.  
  
 I changed the RIFA power bypass caps to K40 Russian PIOs and the WIMA Output caps to Mundorf MKPs.
  
 I'm running it thru a Music Hall 25.3...waiting on a Beckmann (Amperex PQ) 6922 for it now...I'll see how that set-up sounds then, I guess.
  
 TA
 -Mark


----------



## i luvmusic 2

buldogge said:


> i luvmusic 2 said:
> 
> 
> > Those WIMA are nice i would not bother unless you want to change the stock sound,CAPS are more like tubes they do have different sound characteristics.Your ears are different from mine so what sound good for me might not be for you.
> ...


 
 I can't comment on the CAPS because i haven't replace any in my MK III.The most noticeable upgrade that i've done for my MK III is running a C3g,6SN7 and replaced the POT(ALPS BLUE VELVET),The POT is another thing to consider.


----------



## gibosi

Well, I didn't receive any capacitors today but I did get a nice little treasure.   A Philips E80CC apparently manufactured in the NY Amperex factory. While I thought that it was certainly possible that Philips manufactured this tube in the US, I had never seen or even heard mention of one prior to this one popping up on eBay. The price was very decent and I grabbed it. 
  
 Below, the NY tube on the left and the much more common Heerlen tube on the right. The construction is very similar although the metal work above the top mica is slightly different, and most noticeably, the NY tube doesn't have gold pins. The Heerlen tube was manufactured in 1961 (VB8 ⊿1A1) and I suspect the NY tube in 1977 (VBC *7D).
  
 My WAG is that sometime in the 1970's, Philips shifted some production of this tube (and the E182CC, as well) to NY. While there must have been sufficient demand to warrant this expense, the fact that these tubes are quite rare suggests that not all that many were manufactured.
  
 As an aside, with all the talk about C3gs, the E80CC actually has even lower distortion and better linearity. However, it seems that such measurements have little or no relation to how tubes actually sound......
  
 Anyway, I am relieved to report that it lights up and plays. As I tend to prefer NY Philips production to Heerlen, I am very curious to see how this one compares.


----------



## adtrance

gibosi said:


> Below, the NY tube on the left and the much more common Heerlen tube on the right. The construction is very similar although the metal work above the top mica is slightly different, and most noticeably, the NY tube doesn't have gold pins. The Heerlen tube was manufactured in 1961 (VB8 ⊿1A1) and I suspect the NY tube in 1977 (VBC *7D).


 
 Will these work in the Little Dot 1+ without any sort of adapters or modification?


----------



## buldogge

i luvmusic 2 said:


> I can't comment on the CAPS because i haven't replace any in my MK III.The most noticeable upgrade that i've done for my MK III is running a C3g,6SN7 and replaced the POT(ALPS BLUE VELVET),The POT is another thing to consider.


 

 I'm running the same combo, and have switched the pot to one of those eBay HK DACT 21s...definite improvement.
  
 -Mark


----------



## i luvmusic 2

buldogge said:


> i luvmusic 2 said:
> 
> 
> > I can't comment on the CAPS because i haven't replace any in my MK III.The most noticeable upgrade that i've done for my MK III is running a C3g,6SN7 and replaced the POT(ALPS BLUE VELVET),The POT is another thing to consider.
> ...


 
 I have used a 24 Stepped attenuator with my CRACK and i end up replacing it with the Alps blue if i turned the Attenuator at 7 clicks not loud enough at 8 clicks too loud.
  
 This Schiit.....


----------



## gibosi

adtrance said:


> Will these work in the Little Dot 1+ without any sort of adapters or modification?


 
  
 I am afraid not. These are double triodes with the same pinout as a 12AU7. Further, an external heater is required. Even if wired up to run in the 6.3V mode, the heaters draw 0.6A, significantly more than the LD can provide.


----------



## adtrance

I see.  Thanks for the info.
  
 Currently content with my Voskhods and MUSES02 in the 1+.  I might need to wait for the next round of upgrades to pick up a double triode based amp.


----------



## gibosi

gibosi said:


> My WAG is that sometime in the 1970's, Philips shifted some production of this tube (and the E182CC, as well) to NY. While there must have been sufficient demand to warrant this expense, the fact that these tubes are quite rare suggests that not all that many were manufactured.


 
  
 Oh, I just remembered. The manufacture of receiving tubes at the Heerlen factory ceased around 1975-76. So it stands to reason that Philips was beginning to shift production to other factories by the early 1970s. And this would explain why I haven't seen any E182CC or E80CC manufactured in NY before that time.


----------



## spiderking31

gibosi said:


> Made in Great Britain GE 6HM5/6HA5 followup:
> 
> GE Made in Great Britain by GE. Date unknown.
> 
> ...


why would someone want to avoid the short 6ha5's? I own both the 6hm5, and the 6ha5's but don't really notice a difference....why should someone ignore the short 6ha5??? Very curious to know...


----------



## mordy

Hi spiderking31,
  
 Did u try the Ei 6HM5 tubes?


----------



## spiderking31

mordy said:


> Hi spiderking31,
> 
> Did u try the Ei 6HM5 tubes?


i actually own the yougoslavian 6HM5, and a pair of Zenith 6HA5's but don't know what the sound difference is between them though


----------



## gibosi

> why would someone want to avoid the short 6ha5's? I own both the 6hm5, and the 6ha5's but don't really notice a difference....why should someone ignore the short 6ha5??? Very curious to know...


 
  
 I tried a pair of the squat bottles, branded RCA, but manufactured by Siemens, and I found them to be inferior to the tall bottles I tried. In fact, I didn't like them at all. But other than that, there is nothing really wrong with them. It's not like they will damage your amp or anything serious. So if you do decide to try a pair, please tell us what you think of them.


----------



## gibosi

Received a couple ECC808 today:
  
 As labeled, a Telefunken on the left and a Valvo (Hamburg) on the right. These double triodes have yet again a different pin-out than any I have tried thus far, so will have to rewire my socket before I can pop them into my amp. The ECC808 has a mu of about 100, about the same as a ECC83 / 12AX7, and many consider it to be a much improved version, the best of the breed, with less noise and not as prone to microphonics.
  
 Many of us have run 12AX7, most notably, 5751, with very good success so I am very curious how these will compare.


----------



## stvn758

These 6HM5 EC900 EI Yugoslavia tubes are a little too bombastic for me, put my Voskhod Gold pins Gold grid 6ZH1P-EV 6AK5 EF95 403B 5654 6J1 1975 NIB back in.
  
 Does size ahem, matter, the Yugoslavian ones are almost twice the size. Bigger tube bigger sound? I have the gain set low as well, dread to think what they would sound like if I put it up.


----------



## TrollDragon

stvn758 said:


> These 6HM5 EC900 EI Yugoslavia tubes are a little too *bombastic*...


----------



## stvn758

Yep, that's what sprung to mind. 
	

	
	
		
		

		
			





 
  
 Just ordered some power tubes but forgot to get a matched pair, memory is like a sieve these days.


----------



## buldogge

stvn758 said:


> These 6HM5 EC900 EI Yugoslavia tubes are a little too bombastic for me, put my Voskhod Gold pins Gold grid 6ZH1P-EV 6AK5 EF95 403B 5654 6J1 1975 NIB back in.
> 
> Does size ahem, matter, the Yugoslavian ones are almost twice the size. Bigger tube bigger sound? I have the gain set low as well, dread to think what they would sound like if I put it up.


 

 I would give Mullard M8081 a try if you find those a little "too much"...definitely a great sounding, little more laid-back, tube.
  
 -Mark in St. Louis


----------



## stvn758

I don't buy them too often, Mullard are on my list though. These Voskhod ones are very detailed with my AKG712's.


----------



## MIKELAP

Anybody try these adapters  6F8G TO 6CG7 to use with 6F8G tubes as power tubes  would save on a set of adapters  if im not mistaken .                                           http://www.ebay.com/itm/1pc-Gold-plated-6F8G-TO-6CG7-6FQ7-tube-adapter-CMC-Ceramic-socket-/201094583173?pt=LH_DefaultDomain_0&hash=item2ed22bd385


----------



## Nic Rhodes

I have a a pair, work ok.


----------



## SonicTrance

sonictrance said:


> Hi Mordy,
> 
> I'm enjoying it alright
> 
> ...


 
 Ok, I've now tried the chinese 6N13PT's in the LD mk IVSE with the C3GS's driving them. In short they're just terrible tubes, bass is distorting, highs are muddy they just sound awful to my ears anyway. I gave them about 10h before I put the 6H5C's back in. True night and day difference between those tubes, at least in my setup.


----------



## Nic Rhodes

The Russian ones are certainly much preferred in my book also


----------



## buldogge

Hey Guys...Now that I got the MK III fixed (and slightly modded) and my adapters built and running the C3G/6SN7s I need something new to "play with".
  
 I use my Senn 650s with both the MK II and MK III but would love to try something else...Wondering what you guys are using, what you really like with the LDs??
  
 I can't/won't spend HD700/800 $$$ right now though.
  
 Philips X2, Used HE-500, Open box/used HE-400i...or...fiddle/play with some T50RPs???
  
 The T50RPs would be interesting, just because they are "cheap" and I would get some playtime with them...hmmm...but are they worth messing with???
  
 TIA
 -Mark in St. Louis


----------



## gibosi

buldogge said:


> I use my Senn 650s with both the MK II and MK III but would love to try something else...Wondering what you guys are using, what you really like with the LDs??
> 
> I can't/won't spend HD700/800 $$$ right now though.
> 
> ...


 
  
 I would expect that the two HIFIMAN cans, both being low-Z, less than 50 Ohms, might not be the best match for the II and III. I don't know the impedance of the Philips or T50RPs, but again, the II and III are generally better with high-Z cans.


----------



## gibosi

Rewired my 9-pin socket for ECC808 and I am pleased to say that both the Telefunken and the Valvo light up and play. Like the 6DJ8 / ECC88, these have an internal shield, but fortunately, the tube doesn't mind if the shield, on pin-6, is left open, so one less wire to fiddle with.


----------



## MIKELAP

The left channel went out on me did the usual tube swap checked my adapters seem ok ,i noticed something ,read about this before but dont remember the outcome though.What happens is  when i partly remove hedphone jack both channel work .i put in in all the way left doesnt work any ideas  Thanks


----------



## buldogge

mikelap said:


> The left channel went out on me did the usual tube swap checked my adapters seem ok ,i noticed something ,read about this before but dont remember the outcome though.What happens is  when i partly remove hedphone jack both channel work .i put in in all the way left doesnt work any ideas  Thanks


 

 Most likely the volume pot, Mike.
  
 I used the eBay Hong Kong DACT 21, someone else just fitted a Blue Velvet by removing the back cover and cutting the PCB slightly.
  
 http://www.ebay.com/itm/201239685917?_trksid=p2059210.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT
  
 Of course...You can probably just re-solder the little wires, I'm sure one came loose.
  
 If you want fresh, larger AWG wires, you can use this:
  
 http://www.ebay.com/itm/260972483935?_trksid=p2059210.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT
  
 -Mark


----------



## MIKELAP

mikelap said:


> The left channel went out on me did the usual tube swap checked my adapters seem ok ,i noticed something ,read about this before but dont remember the outcome though.What happens is  when i partly remove hedphone jack both channel work .i put in in all the way left doesnt work any ideas  Thanks


 
 Well found my problem small thing finally one of the wires wasnt making a good contact to my dac jack  few in a way ,first thing that came to mind hmmm got more space now lol will it ever end lol.


----------



## MIKELAP

buldogge said:


> mikelap said:
> 
> 
> > The left channel went out on me did the usual tube swap checked my adapters seem ok ,i noticed something ,read about this before but dont remember the outcome though.What happens is  when i partly remove hedphone jack both channel work .i put in in all the way left doesnt work any ideas  Thanks
> ...


 
 Thanks Mark  it was something stupid finally cable not making good contact at  Dac end really didnt take much Speaking of pot or pots lol received a DACT 21 today will install soon see if theres improvement


----------



## buldogge

^^^Glad it was nothing major!
  
 -Mark


----------



## gibosi

sonictrance said:


> Ok, I've now tried the chinese 6N13PT's in the LD mk IVSE with the C3GS's driving them. In short they're just terrible tubes, bass is distorting, highs are muddy they just sound awful to my ears anyway. I gave them about 10h before I put the 6H5C's back in. True night and day difference between those tubes, at least in my setup.


 
  
 Are these the Shuguang 6N13P-T you mentioned earlier? If so, I definitely won't be getting a pair....
  
 However, I am curious about the Dawn Sound 6N13P T. I am wondering if they are relabeled Shuguang, or different?
  
 http://www.ebay.com/itm/221002394824?
  


nic rhodes said:


> The Russian ones are certainly much preferred in my book also


----------



## Oskari

gibosi said:


> However, I am curious about the Dawn Sound 6N13P T. I am wondering if they are relabeled Shuguang, or different?
> 
> http://www.ebay.com/itm/221002394824?


 
  
 That is Shuguang.
  
曙光 (shuguang)  'dawn'


----------



## gibosi

oskari said:


> That is Shuguang.
> 
> 曙光 (shuguang)  'dawn'


 
  
 Thanks! 
  
 So I certainly won't be getting these!


----------



## TrollDragon

buldogge said:


> Hey Guys...Now that I got the MK III fixed (and slightly modded) and my adapters built and running the C3G/6SN7s I need something new to "play with".
> 
> <SNIP>
> The T50RPs would be interesting, just because they are "cheap" and I would get some playtime with them...hmmm...but are they worth messing with???
> ...


 
 The most amazing, tunable, Orthodynamic headphones for the price. I have a slight variation of bluemonkeyflyer's DBV 3 three on mine and they are my main headphones.

 You start by reading through the FIMM thread.
  
 Get your supplies.

  
 Do your Mods.

  
 And enjoy!


----------



## i luvmusic 2

mikelap said:


> buldogge said:
> 
> 
> > mikelap said:
> ...


 
 After i've used Five ALPS BLUE VELVET i thought i was the only one  who really like this POT.
  
 BTW i ordered the A3 stepped attenuator from GlassWare Audio to make a passive preamp will see how this A3 perform.
  
 Originally Posted by *Doc B.* 


  
 I'm saying yes, the Blue Velvet sounded better to me than a PEC in my system.


----------



## buldogge

trolldragon said:


> The most amazing, tunable, Orthodynamic headphones for the price. I have a slight variation of bluemonkeyflyer's DBV 3 three on mine and they are my main headphones.
> 
> You start by reading through the FIMM thread.
> 
> ...


 

 TD...Are those your mods pics???
  
 Any direct suggestions, outside of those in the thread?
  
 TIA
 -Mark


----------



## lekoross

T


----------



## superdux

I have a modded T5ORP too and with some tubes on the MKIII they don't sound that good. Others worked again with them.


----------



## TrollDragon

buldogge said:


> TD...Are those your mods pics???
> 
> Any direct suggestions, outside of those in the thread?
> 
> ...


 
 Hey Mark,
  
 Yes those mod pics are mine.
 There are many great tips in the FIMM and Wow T50RP threads but it can be a lot of reading. The main sound changer is the ear pads from stock to either Shure 840's or MadDog Alphas. The new memory foam HM5's will fit as well but they have to be really stretched and have the possibility or ripping. I used quilt batting instead of rock wool for the insulation as I couldn't get a single piece of rock wool locally. I have a friend who used pink fiberglass insulation on his and it works for him.
  
 Start with the Shure 840 pads as they roll on and off really easily. Use masking tape on the outside with different sized holes to tune the level of bass that you want Then cut that size hole in the cardboard to be taped on the inside for the finished version. I cut a piece of Veg Tan leather as a comfort band, it makes them much more comfortable over the rubber headband.
  
 Mass loading the driver plate with plasticine will reduce vibrations. You are leveling out the back of the cup with the paxmate and felt. Remember that you can tune these the way you want them, with treble disks and bass port mods. When they first arrived I let the wife listen to them and she said "You picked these up why? They sound terrible!" After the mods she couldn't believe they were the same headphones. 
	

	
	
		
		

		
		
	


	



  
 You can build the microphones for them and run the software to see what you are doing but I never bothered with that. BMF had a great tip of using masking tape to hold the drivers to the cups during incremental mods as it keeps the screw posts from stripping.
  
 I also installed dual entry tiny xlr 4 jacks in mine. The tiny xlr jack will JUST fit into the corner of the cup housing and has to be epoxied in as there is no room for the nut. I left the headband wire intact and connected them up so I can use them with my short single sided tiny xlr to 3.5mm cable as well which is why I used 4 pin connectors. I can also go balanced if I get an amp down the road.
  
 If the headphone will take a tiny xlr, it gets one! 
	

	
	
		
		

		
		
	


	



  
  
 Get yourself a pair of T50RP's and have some fun with them.


----------



## mordy

I recently bought a Yamaha MT-220 set of headphones based on the recommendation of Lorspeaker. These headphones can be found for $149.99. (List price around double that.)
  
 http://www.amazon.com/Yamaha-HPH-MT220-monitor-over-ear-headphones/dp/B00B44N0DA/ref=sr_1_1?ie=UTF8&qid=1426384351&sr=8-1&keywords=Yamaha+MT-220
  
 There is an entire thread devoted to them and ways of tuning them:
  
 http://www.head-fi.org/t/658673/yamaha-hph-mt220-thread-merged/720
  
 Until now it never occurred to me that you can fine tune headphones, but once I read about it, it makes perfect sense.
  
 The biggest difference so far is to stuff some gauze in the back portion of the ear cushions to change the angle of the drivers towards your ears. Speaker placement, eh?
  
 These are low Z cans, but they do pretty well with my MKIII running 2,500 horsepower tubes (2.5A). There are more mods to do by substituting cork for a felt pad inside the headphones, but I haven't tried it yet.
  
 BTW, using fiberglass padding is not recommended. I know that TD always is safety conscious, and I was surprised to read his mention of somebody using pink fiberglass insulation_. "OSHA even requires fiberglass insulation to be packaged with a label citing it as a possible carcinogen. Several government agencies, including the Environmental Protection Agency recognize the carcinogenic potential of fiberglass insulation_."


----------



## TrollDragon

mordy said:


> BTW, using fiberglass padding is not recommended. I know that TD always is safety conscious, and I was surprised to read his mention of somebody using pink fiberglass insulation_. "OSHA even requires fiberglass insulation to be packaged with a label citing it as a possible carcinogen. Several government agencies, including the Environmental Protection Agency recognize the carcinogenic potential of fiberglass insulation_."


 
 Yes I wouldn't use it, I don't even like moving the stuff around when working with electrical repairs.
  
 But many in the T50RP thread have used it with decent results. I'll stick to the quilt batting.


----------



## SonicTrance

gibosi said:


> Are these the Shuguang 6N13P-T you mentioned earlier? If so, I definitely won't be getting a pair....
> 
> However, I am curious about the Dawn Sound 6N13P T. I am wondering if they are relabeled Shuguang, or different?
> 
> http://www.ebay.com/itm/221002394824?


 
 Those are the ones, yes. And no, I wouldn't recommend them to anybody.


----------



## buldogge

To continue with my headphone/Little Dot sidebar...
  
 Anyone have/like the Beyer DT880 (250 or 600?) or T90 with the LDs???
  
 TA
 -Mark in St. Louis


----------



## TrollDragon

buldogge said:


> To continue with my headphone/Little Dot sidebar...
> 
> Anyone have/like the Beyer DT880 (250 or 600?) or T90 with the LDs???
> 
> ...


 
 DT880's the budget king of neutral!
  
 250's here, picked up the LD MK IV especially for them.


----------



## buldogge

^^^TD, Did you choose the 250 over the 600, specifically?  
  
 Also, did you do the re-cabling on those?  How difficult is it (never had Beyers to have them apart)??
  
 TA
 -Mark


----------



## TrollDragon

buldogge said:


> ^^^TD, Did you choose the 250 over the 600, specifically?
> 
> Also, did you do the re-cabling on those?  How difficult is it (never had Beyers to have them apart)??
> 
> ...


 
 Hey Mark,
  
 Yes I re-cabled those myself, they are easy to get apart with just a small flat screwdriver.

 The voice coil wires on the drivers are very fine and the tabs or tangs they attach to are just press fit into the driver housing. They are extremely easy to tear out which will render the driver useless. If your lucky you can reattach the wire like a few of us have done here. So you need to pop out the driver housing with great care.
  
 I chose the 250 over the 600 as there is minimal if not any sound difference and the 250's will work with a greater variety of devices.


----------



## buldogge

Thanx TD...
  
 Has anyone tried/compared the DT880s and T90s with the Little Dots???
  
 I'm wavering around DT880, T90, or HE-500 (maybe 400i).
  
 I'm also trying to pick up a cheap pair of T50RPs to mess around with, but that's a whole different kettle of fish.
  
 TA
 -Mark


----------



## MIKELAP

I have a spare  6DJ8 tube adapter for sale if interested send me a PM please  .Thank you .


----------



## SkyDoc

Thanks so much. I just bought a LD I+ w/ the 6cq6 tube upgrade. The tubes are probably Chinese , but it is a starting point. Your post helped declutter a pretty confusing mess of read and reread posts as well as other online searches I've done. I'll probably tell you my impressions after I get the lil' darlin'. Hers a question. What intro headphones would you use w/ this amp. I know ears are ears and everyone's is different. I have a pair of Audio Technica AD700's that I think will work w/ this amp since for me the AT 700's are a pretty blank slate musically for me. Again thanks. Next Op Amps.......


----------



## adtrance

My Grado 325e is an excellent pairing with the Little Dot 1+, and so is the HD600.  The volume nob just gets turned a bit more on the Senn to match the Grado.
  
 Running Voskhod tubes and the MUSES02 opamp.


----------



## spiderking31

I'm using the Yugoslavian 6HM5's and they are superior to the 6HA5's IMHO....I'm currently using the Voshkod 6ZH1P-EV's, and they're freaking incredible!!!! My top 2 tubes are Voshkod's in first place, followed by 6HM5's and third place being my Tesla 6F32's


----------



## adtrance

I'm burning in the Ei 6HM5's (barely have 3-4 hours on them currently), and they do not have the detail or the mid-range clarity that the Voskhods do.  Right now I would say 6ZH1P-EV, GE JAN 5654W, Ei 6HM5 in order of preference.


----------



## spiderking31

Voshkod's are the best I've come across actually, and I also own the GE 5654W's as well, including the Yugoslavian 6HM5's, so I have to plug in the 5654W's only because it's been roughly 2 years since I last listened to them. Might be interesting


----------



## jaywillin

i just got a pair of voshkods, arrived yesterday, i've had a few pairs of of driver tubes i though were very nice, and these are sure to be among those, they've only got a few hours on them
 and i already like the sound, and they are dead quiet


----------



## TrollDragon




----------



## spiderking31

They're very impressive to my ears honestly, and I own about 11 different types of tubes that can be used with my little dot MK3, and I can't stop listening to my CD's with the Voshkod's! They're that good! IMHO Anyways


----------



## Oskari

trolldragon said:


>


 
  
 Yo, TD! You may have to tell the noobs around here that the proper transliteration of Восход (in English) is *Voskhod*.


----------



## jaywillin

trolldragon said:


>


 
  
  


oskari said:


> Yo, TD! You may have to tell the noobs around here that the proper transliteration of Восход (in English) is *Voskhod*.


 
 (hangs my head in shame) i'm always doing that , my dyslexia will kick in


----------



## spiderking31

Ok, I'm not a noob for one, and type in Voshkod, and that's how it's spelled in English! American English....


----------



## Oskari

spiderking31 said:


> Ok, I'm not a noob for one, and type in Voshkod, and that's how it's spelled in English! American English....


 
  
 Looks like a noob, spells like a noob...


----------



## adtrance

NOS '87 voskhods just came in and they have a vertical ridge/indent on them that I didn't notice on my '73.  I still need to give the 6HM5's until the weekend for a decent burn in (~25 hours) before I pull them out but I'm really curious if there's much of a difference between the '73 and '87.


----------



## superdux

mikelap said:


> I have a spare  6DJ8 tube adapter for sale if interested send me a PM please  .Thank you .


 
  
 I have already bought an adapter from MIKELAP and they are really sturdy and wellbuilt. Excellent craftsmansship.
 But the best thing is with this adapter you can run the well known 6N23P Voskhods preferably from the seventies as for the 75s have become hail and praise but they're hard to find and soooooo expensive now.


----------



## spiderking31

I founded a Facebook group, and have almost 5000 members. 100% of my members know how it's spelles...including myself ☺️ Thanks again!


----------



## Oskari

spiderking31 said:


> I founded a Facebook group, and have almost 5000 members. 100% of my members know how it's spelles...including myself ☺️ Thanks again!


 
  
 A million flies...


----------



## TrollDragon

oskari said:


> Yo, TD! You may have to tell the noobs around here that the proper transliteration of Восход (in English) is *Voskhod*.


 
 Indeed!
  
 And another refresher for the noobs here, your post about Philips.


----------



## MIKELAP

trolldragon said:


> oskari said:
> 
> 
> > Yo, TD! You may have to tell the noobs around here that the proper transliteration of Восход (in English) is *Voskhod*.
> ...


 
 Are we going to end up posting pictures of YUGOS again .I can feel it !


----------



## TrollDragon

Quote: Matthew 7:7–8 





> Ask and it will be given to you...


 

 The infamous Yugo 6HM5...


----------



## mordy

I like the tube glow of this Yugo....
  




  
 Here is a picture of my own car, nicknamed "The Toaster.":


----------



## Oskari

This calls for a photo of the infamous Multipla, but posting one would be too cruel and would inevitably lead to the Aztek.


----------



## mordy

Extra points if u can identify the last car


----------



## MIKELAP

trolldragon said:


> Quote: Matthew 7:7–8
> 
> 
> 
> ...


 
 She's a bute magwheels sporty gas cap oh ya !!!


----------



## MIKELAP

mordy said:


> Extra points if u can identify the last car


 
 Is that a Messerscmitt  or its italian dont remember the name


----------



## buldogge

trolldragon said:


> Hey Mark,
> 
> Yes I re-cabled those myself, they are easy to get apart with just a small flat screwdriver.
> 
> ...


 

 Ended up grabbing some Beyer T90s...
  
 Anyone have tube pairing recommendations for these cans?  Can be EF95/EF92/EF91 or C3G and 6SN7s or Russian powers.
  
 TIA
 -Mark


----------



## gibosi

Well, it appears that a "new" regulator I just got, a Tung-Sol 3DG4, was on its last legs and shorted out the first time I plugged it in to the Glenn. As designed, no damage, it just took out the amp's fuse. However, I don't have any spares around the house, so will be out and about tomorrow to see if I can find some: T4AL 250V. These appear to be common, so with a little luck the Glenn should be back in business soon.
  
 So this evening, I have some time to spend with the LD and the two recently arrived ECC808.


----------



## Oskari

mordy said:


>


 
  
 What is that?


----------



## i luvmusic 2

These guys car.......


----------



## i luvmusic 2

gibosi said:


> Well, it appears that a "new" regulator I just got, a Tung-Sol 3DG4, was on its last legs and shorted out the first time I plugged it in to the Glenn. As designed, no damage, it just took out the amp's fuse. However, I don't have any spares around the house, so will be out and about tomorrow to see if I can find some: T4AL 250V. These appear to be common, so with a little luck the Glenn should be back in business soon.
> 
> So this evening, I have some time to spend with the LD and the two recently arrived ECC808.


 
 Your lucky it's just a fuse once i blew a fuse and a resistor it took me sometime to figured out why the amp sounded different after i replaced the blown fuse.There was no burning smell or discoloration on the resistor.


----------



## gibosi

Spent much of yesterday evening with the Valvo (Hamburg) ECC808 and I think this is a terrific tube. It is definitely better than any ECC83/12AX7 I have tried in the LD.
  
 Pictures and more info here:
  
 http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/9300#post_11405037
  
 http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/9300#post_11410837
  
 Again the pinout is different than other double triodes I have tried, so for those using an external 9 pin socket it will be necessary to rewire accordingly. 
  
 9 Pin socket                                 Left LD socket                    Right LD socket
  
 1 grid section 2                                                                                   1
 2 cathode section   2                                                                           2
 3 anode section 2                                                                                5
 4 heater - external PS (or LD pin 3)                                                       (3)          
 5 heater - external PS (or LD pin 4)                                                       (4)
 6 shield - no connection                                        
 7 anode section 1                                    5
 8 cathode section 1                                 2
 9 grid section 1                                       1
  
 Have fun! 
  
 Edit: Heater current is only 340ma, so the LD's internal heaters will be fine.


----------



## gibosi

i luvmusic 2 said:


> Your lucky it's just a fuse once i blew a fuse and a resistor it took me sometime to figured out why the amp sounded different after i replaced the blown fuse.There was no burning smell or discoloration on the resistor.


 
  
 Yes, I was lucky. And this morning, found replacement fuses close by and the Glenn is alive and well again.


----------



## i luvmusic 2

gibosi said:


> i luvmusic 2 said:
> 
> 
> > Your lucky it's just a fuse once i blew a fuse and a resistor it took me sometime to figured out why the amp sounded different after i replaced the blown fuse.There was no burning smell or discoloration on the resistor.
> ...


 
 The 6SN7 GTB was the one shorted in my CRACK the fuse did not blow right away i usually turned the amp on and leaved it for a few minutes before listening and i noticed the tube was glowing bright blue.
  
 I'am glad that your amp is all well.


----------



## mordy

Hi Oskari,
  
 Came across the funny picture of the fat car, but I cannot find any information about it, except for that one site calls it "Obese Cadillac."
  
 However, I discovered that you can search Google Images using a picture:
  
 https://images.google.com/imghp?hl=en&gws_rd=ssl
  
 Just drag the picture into the search box and that's it. I tried your Avatar of the Finnish landscape and found several of your recent posts on Head-Fi.
  
 Nothing is safe any more....


----------



## Oskari

mordy said:


> However, I discovered that you can search Google Images using a picture


 
  
 I actually tried that but couldn't find any information.
  


> I tried your Avatar of the Finnish landscape


 
  
 That, by the way, is a night view from the hotel room window at Koli National Park.


----------



## mordy

Remember the Internet Bubble? Well, everybody knew it would not last, but i took a chance on some investments and pulled out $1400 when everything was going up and bought a state of the art headphone amp: The Headroom Max. The year was 1999. I also got a pair of Sennheiser HD600 headphones. Then the bubble burst, but I had my gear at least.
  
 Why did I go to such excess? (The amp in today's dollars would cost around $2400.)
  
 The reason was that I wanted to savor Class A sound, and i could not afford a $20,000 system, so I figured, let me try this at least. Sad to say, even though the amp reproduced everything very well, I could not get used to listening through headphones and the ss sound of the amp.
  
  








  
 One such amp was advertised on Head-Fi:
  
 http://www.head-fi.org/t/468734/sold-headroom-max-original-owner
  
 Can anybody give me suggestions on how much it is worth and where to sell it? It has been sitting unused for a long time, but is in perfect condition and works perfectly as well.


----------



## bobbyblack

Hi guyz just 1 question:my volume pot on the LD MK3 became so noisy on left channel,what can i do?

Thanks!


----------



## MIKELAP

bobbyblack said:


> Hi guyz just 1 question:my volume pot on the LD MK3 became so noisy on left channel,what can i do?
> 
> Thanks!


 
 Try cleaning it with Deoxit or something similar usually that does it for awhile but be careful removing pot assembly  not to break off wires they are very easy to break. Lately i changed the pot to a dact type 21 stepped attenuator 100k 2a3 works great 
  
  
 http://www.ebay.com/itm/DACT-Type-21-Stepped-Attenuator-Potentiometer-100K-2A3-/201239685917?pt=LH_DefaultDomain_0&hash=item2edad1eb1d


----------



## bobbyblack

mikelap said:


> Try cleaning it with Deoxit or something similar usually that does it for awhile but be careful removing pot assembly  not to break off wires they are very easy to break. Lately i changed the pot to a dact type 21 stepped attenuator 100k 2a3 works great
> 
> 
> http://www.ebay.com/itm/DACT-Type-21-Stepped-Attenuator-Potentiometer-100K-2A3-/201239685917?pt=LH_DefaultDomain_0&hash=item2edad1eb1d


Is hard to change the pot?If not i'm gonna buy it,thank you !


----------



## MIKELAP

bobbyblack said:


> mikelap said:
> 
> 
> > Try cleaning it with Deoxit or something similar usually that does it for awhile but be careful removing pot assembly  not to break off wires they are very easy to break. Lately i changed the pot to a dact type 21 stepped attenuator 100k 2a3 works great
> ...


 
 No, if you can solder and have a tester to identify what wire goes where.


----------



## i luvmusic 2

Or if you can cut the wires one at a time from the old pot and solder it to the corresponding lugs onto the new pot.


----------



## buldogge

i luvmusic 2 said:


> Or if you can cut the wires one at a time from the old pot and solder it to the corresponding lugs onto the new pot.


 

 The OE wires are ridiculously small and fragile...I would replace them with a new wiring harness.  Since it uses a 5 wire JST 4S harness, just make sure you assign a color from the new harness to a color from the old harness in the same order/position.
  
 I bought this  one...22AWG, reasonable quality: http://www.ebay.com/itm/JST-XH-4S-14-8v-Lipo-Balance-Wire-Extension-Lead-8-5-inches-/260972483935
  
 It appears to be sold out, but here is another, which appears to be the same:  http://www.ebay.com/itm/New-JST-JST-XH-4S-Balance-Wire-Extension-20cm-Adapter-14-8v-Lipo-Battery-Charge-/131155665680?pt=LH_DefaultDomain_0&hash=item1e897ca310
  
 -Mark in St. Louis


----------



## i luvmusic 2

that's even better.............


----------



## bobbyblack

mikelap said:


> No, if you can solder and have a tester to identify what wire goes where.


And without stepper attenuator some good knobs where i find to be compatible?I found this:http://www.ebay.com/itm/100-Original-Japan-ALPS-27-type-blue-Volume-potentiometer-2X50K-/221566575294?pt=LH_DefaultDomain_0&hash=item339665a2be


----------



## bobbyblack

buldogge said:


> The OE wires are ridiculously small and fragile...I would replace them with a new wiring harness.  Since it uses a 5 wire JST 4S harness, just make sure you assign a color from the new harness to a color from the old harness in the same order/position.
> 
> I bought this  one...22AWG, reasonable quality: http://www.ebay.com/itm/JST-XH-4S-14-8v-Lipo-Balance-Wire-Extension-Lead-8-5-inches-/260972483935
> 
> ...


----------



## i luvmusic 2

bobbyblack said:


> And without stepper attenuator some good knobs where i find to be compatible?I found this:http://www.ebay.com/itm/100-Original-Japan-ALPS-27-type-blue-Volume-potentiometer-2X50K-/221566575294?pt=LH_DefaultDomain_0&hash=item339665a2be


 
 If you decide to used the ALPS BLUE VELVET then you have a lot of work ahead of you and you need 100K pot.


----------



## MIKELAP

Last weekend got myself an amp that would incorporate at least 2 types of tubes i wanted to have in an amp 6AS7 and  6SN7 types so since getting the Elise was to expensive because of currency and customs bought an amp here instead that incorporates all i was looking for and more at a very good price  a Woo Audio 22 yes another Woo i guess i like those amps lol.


----------



## buldogge

I think I'll eventually machine a front face extension/box for a ALPS Blue Velvet.  I'm thinking that it will have a circular lip that will interface with the LD faceplate and be held by set screw throughout the retention hole...then the main body will be a square to accommodate the ALPS, with separate faceplate to match the shaft and retention spot.
  
 What's the best place/best price t pick a Blue Velvet up at???
  
 -Mark


----------



## TrollDragon

mikelap said:


> Last weekend got myself an amp that would incorporate at least 2 types of tubes i wanted to have in an amp 6AS7 and  6SN7 types so since getting the Elise was to expensive because of currency and customs bought an amp here instead that incorporates all i was looking for and more at a very good price a Woo Audio 22 yes another Woo i guess i like those amps lol.


 
*Many Congratulations on the New Woo!*










  
 You are now going to have to get yourself a set of balanced cables and a balanced DAC to go with it...
  
 The Q French Silk cable is *very nice* and you will need the matching HD800 adapter.

  
 Also:
 Don't say BALANCED too loud or we will have @Mshenay in the thread extolling the virtues of a balanced system...


----------



## i luvmusic 2

buldogge said:


> I think I'll eventually machine a front face extension/box for a ALPS Blue Velvet.  I'm thinking that it will have a circular lip that will interface with the LD faceplate and be held by set screw throughout the retention hole...then the main body will be a square to accommodate the ALPS, with separate faceplate to match the shaft and retention spot.
> 
> What's the best place/best price t pick a Blue Velvet up at???
> 
> -Mark


 
 In CANADA Parts connexion (most boutique components are in there) 30 mins from my home..........


----------



## i luvmusic 2

trolldragon said:


> >
> 
> 
> 
> ...


 
 What happen to that guy i haven't see/heard anything from him for a while?Unless he changed his name and his with us in this thread.


----------



## gibosi

Received a pair of Lorenz CG3 today. Up until MrX's recent posting showing a picture of a Lorenz and Siemens C3g, I had believed that all C3g were manufactured by Siemens regardless of the label. However, that picture certainly changed my mind. lol 
  
 http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/9180#post_11350547
  
 So when I saw Superdux's recent post about some cheap Lorenz C3g (Auction Nr.261797955911) I grabbed a pair. Even though they are still in their cans, their physical appearance certainly suggests that these were not manufactured by Siemens. The Lorenz sound great, but I haven't had them long enough to burn them in, much less compare them to the Siemens.
  

  

  

  
 .


----------



## TrollDragon

i luvmusic 2 said:


> What happen to that guy i haven't see/heard anything from him for a while?Unless he changed his name and his with us in this thread.


 

 Don't know... He is still active, must be busy in the HiFiman threads...


----------



## SonicTrance

gibosi said:


> Received a pair of Lorenz CG3 today. Up until MrX's recent posting showing a picture of a Lorenz and Siemens C3g, I had believed that all C3g were manufactured by Siemens regardless of the label. However, that picture certainly changed my mind. lol
> 
> http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/9180#post_11350547
> 
> ...


 
 So Lorenz also makes c3g's with gold pins. Didn't know that. Not that it makes a huge difference, lol.


----------



## SonicTrance

mikelap said:


> Last weekend got myself an amp that would incorporate at least 2 types of tubes i wanted to have in an amp 6AS7 and  6SN7 types so since getting the Elise was to expensive because of currency and customs bought an amp here instead that incorporates all i was looking for and more at a very good price  a Woo Audio 22 yes another Woo i guess i like those amps lol.


 
 Nice, I got a pair of those Psvane treasure cv181's pictured on the way too. Have fun with your new amp!


----------



## mordy

Hi Gibosi,
  
 I am under the impression that Telefunken also made C3g tubes. Don't know if the C3g tubes marked Valvo were made by Valvo.


----------



## mordy

Hi Mikelap,
  
 Congrats on your new amp! Looks like it could use 6080 tubes as well. If you want to try Sylvania 6080 tubes from the 60s, let us know your impressions - these are my favorite power tubes in the modded LD MKIII.


----------



## bobbyblack

mikelap said:


> Last weekend got myself an amp that would incorporate at least 2 types of tubes i wanted to have in an amp 6AS7 and  6SN7 types so since getting the Elise was to expensive because of currency and customs bought an amp here instead that incorporates all i was looking for and more at a very good price  a Woo Audio 22 yes another Woo i guess i like those amps lol.


Congrats Mike,i heard it in shop with Senn HD650 and Senn HD800 only half an hour and i liked enough .


----------



## gibosi

mordy said:


> Hi Gibosi,
> 
> I am under the impression that Telefunken also made C3g tubes. Don't know if the C3g tubes marked Valvo were made by Valvo.


 
  
 Since the Telefunkens and Valvos I am seeing have the same smooth shiny black cans as the Siemens, I have much less confidence that these are anything but Siemens. That said, if I find a pair of either of these for a cheap, will definitely give them a try.


----------



## MIKELAP

mordy said:


> Hi Mikelap,
> 
> Congrats on your new amp! Looks like it could use 6080 tubes as well. If you want to try Sylvania 6080 tubes from the 60s, let us know your impressions - these are my favorite power tubes in the modded LD MKIII.


 
 Thanks mordy those are not my tubes in the picture above  what i have in there are 2- TS 5998 2- Marconi 6F8G and 1- Brimar 5Z4GY rectifier .


----------



## jaywillin

got the adapters in, sounding suhweet , i must say


----------



## mordy

Hi jaywillin,
  
 What kind of tubes are u using? EF95 and 6SN7?


----------



## d4rkch1ld

jaywillin said:


> got the adapters in, sounding suhweet , i must say



If u put 6AS7G in there it will blow your mind(ears)


----------



## jaywillin

mordy said:


> Hi jaywillin,
> 
> What kind of tubes are u using? EF95 and 6SN7?


 
 i have a pair of yugo 6hm5's up front and sylvania's to the rear


----------



## jaywillin

d4rkch1ld said:


> If u put 6AS7G in there it will blow your mind(ears)


 
 so far, while maybe not blown, but the brain is very happy, and the ears are still intact ,


----------



## mordy

This is a nice combination, but d4rkch1ld is right - putting in 6AS7/6080 power tubes brings it up to a different level. The ultimate mod of the LD MKIII adds C3g tubes as driver tubes.
  
 I have been running this combination (6080/C3gS) for several months now, and it only gets better. End game?
  
 I think so, at least for the LD MKIII. The next step up would be a different, much more expensive amp......However, I am perfectly happy with this combination, at least for now....


----------



## jaywillin

oh i'm loving the 6sn7's i just meant nothing blew up ! lol
 which for some reason, i was a little nervous before i hit the power switch, 
 i'm hearing more depth and weight , the bass goes lower and is tight, well controlled , instruments have better separation , i'm a very happy camper !


----------



## jaywillin

mordy said:


> This is a nice combination, but d4rkch1ld is right - putting in 6AS7/6080 power tubes brings it up to a different level. The ultimate mod of the LD MKIII adds C3g tubes as driver tubes.
> 
> I have been running this combination (6080/C3gS) for several months now, and it only gets better. End game?
> 
> I think so, at least for the LD MKIII. The next step up would be a different, much more expensive amp......However, I am perfectly happy with this combination, at least for now....


 
 oh 6as7s or 6080 ?? i wasn't aware, i missed it !
 use the same adapter combo ?


----------



## SonicTrance

jaywillin said:


> oh 6as7s or 6080 ?? i wasn't aware, i missed it !
> use the same adapter combo ?


 
 You use the same adapter for 6AS7/6080 as you do for 6SN7 but you need an external psu for the heaters.


----------



## jaywillin

sonictrance said:


> You use the same adapter for 6AS7/6080 as you do for 6SN7 but you need an external psu for the heaters.


 
 uh oh, sounds like some skills might be needed ?


----------



## hypnos1

mordy said:


> This is a nice combination, but d4rkch1ld is right - putting in 6AS7/6080 power tubes brings it up to a different level. The ultimate mod of the LD MKIII adds C3g tubes as driver tubes.
> 
> I have been running this combination (6080/C3gS) for several months now, and it only gets better. End game?
> 
> I think so, at least for the LD MKIII. The next step up would be a different, much more expensive amp......However, I am perfectly happy with this combination, at least for now....


 
  
 Yes indeed mordy...end game combination for sure - and not just for humble LDs!! (Especially for those lucky enough to have/acquire the GEC 6AS7G equiv.).


jaywillin said:


> uh oh, sounds like some skills might be needed ?


 
 Hi j.
  
 All the info you need is in past posts... study carefully and if you do go ahead you will be well rewarded!


----------



## i luvmusic 2

BEWARE using 2 6080/6AS7G even with External Power Supply it still make your amp HOTTER than usual.


----------



## mordy

I have used 6080 power tubes for months without problems, but I have two small cooling fans (from a discarded computer) pulling away air from the amp.
  
 In the beginning it used to get warmer, but now it runs very cool and barely gets warm to the touch.


----------



## Shaffer

Please forgive a question that was likely asked before. Is there a sonic difference between 6N6P-I and 6N6P-IR? I would truly appreciate an experienced opinion. Thank you all in advance.


----------



## MIKELAP

shaffer said:


> Please forgive a question that was likely asked before. Is there a sonic difference between 6N6P-I and 6N6P-IR? I would truly appreciate an experienced opinion. Thank you all in advance.


 
 You will find reviews here page 201 post# 3007
                                                                http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/3000


----------



## Shaffer

mikelap said:


> You will find reviews here page 201 post# 3007
> http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/3000




Thank you very much. Just ordered a pair of the 6N6P-IR.


----------



## mordy

Hi Shaffer,
  
 If you want high performance WRX STi power tubes, you would have to take the leap to 6AS7/6080 tubes....
  
 And if you just want to go with the WRX, get a pair of 6SN7 tubes with adapters - no mods required, just plug and play.


----------



## gibosi

I was able to do a quick comparison of the Siemens and Lorenz C3g yesterday. This is not an in-depth review. I simply listened to a couple songs to see what differences, if any, stood out. As I do not have the ears nor the patience to carefully parse and articulate small and subtle differences between tubes, I will leave it to others to perform a more in-depth comparison.

 Starting first with the Siemens and then the Lorenz, I caught myself reflexively reaching out to turn-up the volume with the Lorenz. The Siemens are definitely more forward and brighter. As the Siemens are also somewhat brighter than my favorite double triodes, for example, the small-bottle Sylvania 6SN7W, I am finding myself preferring the more subdued sound of the Lorenz.
  
 Otherwise, their tonality seems very similar and I find both to have great clarity, transparency and detail. Unlike MrX's experience, the Lorenz are just as quiet as the Siemens. While it might not matter, my tubes have gold pins. unique serial numbers and arrived in German military packaging.
  

  
  

  

  
 So, these two tubes do in fact sound different, which is certainly not surprising. After all, they were manufactured in different factories owned by two different companies.
  
 Also, I noticed that the guide-pin on the Lorenz is shaped somewhat differently than that of the Siemens. As a consequence, the Lorenz fits into the socket a bit more tightly, which makes it more difficult to extract it. In fact, I was originally going to make this comparison using the Little Monster Dot, but was reluctant to apply the force necessary to plug the Lorenz into my adapters. It was considerably easier to use the built-in sockets on the Glenn.
  
 Even so, as reported here, others have had these tubes crack when rolling and pulling them out of tight-fitting sockets, so I adopted Mordy's technique and use a small flat-bladed screwdriver when extracting the Lorenz. On the other hand, a screwdriver isn't needed to extract the Siemens from the Glenn.


----------



## mordy

Hi Gibosi,
  
 Thanks for the comparison. I'll see if I can pick up a pair on German Ebay. Now we have to know if the Telefunken C3g is different as well.....


----------



## gibosi

If only we could find out whether Telefunken manufactured the C3g, or if they simply sourced and resold Siemens tubes under their own name. From the pictures I have seen, the Telefunkens look identical to the Siemens, except for the silk screening. If someone does purchase a pair of Telefunkens and removes the cans, I hope they will post some pictures so we can compare the internal construction.


----------



## Shaffer

mordy said:


> Hi Shaffer,
> 
> If you want high performance WRX STi power tubes, you would have to take the leap to 6AS7/6080 tubes....
> 
> And if you just want to go with the WRX, get a pair of 6SN7 tubes with adapters - no mods required, just plug and play.




Heh, I own an Evolution IX. That must be, what, a 6550? 

I actually have some 6SN7s. Something to consider. Thanks!

Edit: If I may be an even bigger PITA, which adapters would I need?


----------



## jaywillin

shaffer said:


> Heh, I own an Evolution IX. That must be, what, a 6550?
> 
> I actually have some 6SN7s. Something to consider. Thanks!
> 
> Edit: If I may be an even bigger PITA, which adapters would I need?


 
 Here is a link to a pair of socket extenders:
  
http://www.ebay.com/itm/2PCS-9-PIN-TUBE-SOCKET-SAVER-FOR-12AX7-12AU7-ECC82-ECC83-tube-amp-audio-DIY-part-/161584664637?pt=LH_DefaultDomain_0&hash=item259f32503d
  
 Here is a link to the octal to 9pin adapters:
  
http://www.ebay.com/itm/191082280257?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT


----------



## Shaffer

jaywillin said:


> Here is a link to a pair of socket extenders:
> 
> 
> 
> ...




I very much appreciate your time.

If you don't mind, I'd like to ask a few questions later; it's a matter of me thinking them through.


----------



## Oskari

gibosi said:


>


 
  
 I can see the date on the Lorenz box. Do you have Siemens dates?


----------



## gibosi

oskari said:


> I can see the date on the Lorenz box. Do you have Siemens dates?


 
  
 Unfortunately no. I have two pairs of Siemens, C3g and C3g-S, and there are no dates on the boxes or the tubes. Both came packaged in the typical vivid orange and blue boxes that are so common on eBay. Since these are the not the old-style boxes, it leads me to think they could be as late as the 1970's or even the 1980's. And the packaging of the Lorenz tubes does make me wonder why I have not seen Siemens, Telefunkens or Valvos in military boxes....


----------



## Oskari

Just entertaining the possibility that the difference might be the vintage instead of the factory...


----------



## gibosi

And yes, I have wondered about that possibility as well...


----------



## mordy

Hi Gibosi,
  
 Take a look at this Telefunken C3g - looks very similar to the Siemens:
  





 Could the date be Dec 1977?
  
 However, here is another one that looks like the Lorentz?
  




  




  
 Don't know what to think....


----------



## mordy

Best photo of a C3g:
  




  
 Let's make it suitable for a poster:


----------



## gibosi

Yes, I have seen this tube on eBay. And perhaps "77" indicates 1977 was the year of manufacture.  And here is another one which appears to be dated 1978.
  




  
 I have found Telefunken, Lorenz and Siemens datasheets for C3g via Google.
  
 http://frank.pocnet.net/sheets/062/c/C3g.pdf
  
 http://frank.pocnet.net/sheets/128/c/C3g.pdf
  
 http://frank.pocnet.net/sheets/190/c/C3g.pdf
  
 It seems to me that if Lorenz and Telefunken were not making these tubes, they would not have published these datasheets. But of course, I could be wrong.... Speculating further, perhaps in the 1950s and 1960's, each of these three companies did in fact manufacture the C3g. But into the mid 1970's, demand for these tubes began to fall, Telefunken and Lorenz ceased production, and Siemens remained the only manufacturer. As best I can tell, all these tubes with shiny black cans appear to have been manufactured in the same factory in the 1970's. 
  
 But it is certainly possible that Lorenz and Telefunken never manufactured these tubes. Perhaps, every last one of them were manufactured by Siemens, and the construction differences between my Lorenz and Siemens are due simply to different manufacturing dates.....
  
 So I am looking for 1960's vintage Telefunken and Siemens.
  
 I would guess that these C3ms with embossed logos on top might be older versions.... Perhaps they were they all manufactured in the same factory? Or maybe not?


----------



## mab1376

mordy said:


> Best photo of a C3g:


 
  
 Great photo! Is that blue actually from the tube? which brand is that one, my Siemens doesn't seems to have any blue in the glow.


----------



## mordy

Found the photo on the internet from a guy in Sweden (don't know which brand). My C3g tubes are still in their metal cans. Opened one up and slipped with the screwdriver and cut my finger - once is enough!
  
 Anyhow, I am thoroughly enjoying my Siemens C3gS/Sylvania 6080 combination and don't really feel that I am lacking anything, But Hypnos put a bug in my head with his praise of the Feliks Elise....
  
 If I can sell my Headroom Max amp and my Mirage S3i speakers I may go for more expensive stuff...Not to mention the Dunlap-Clarke Dreadnaught 250 amp.


----------



## mordy

Hi Gibosi,
  
 I have Siemens C3g tubes with the embossed logos and with the printed logos.


----------



## Oskari

mordy said:


> http://www.ebay.de/itm/KONVOLUT-VON-80-POSTROHREN-C3g-C3m-TELEFUNKEN-SIEMENS-LORENZ-VALVO-/271780920171?pt=R%C3%B6hren&hash=item3f4767bb6b


 
  


> Originally Posted by *gibosi* /img/forum/go_quote.gif
> 
> But it is certainly possible that Lorenz and Telefunken never manufactured these tubes. Perhaps, every last one of them were manufactured by Siemens, and the construction differences between my Lorenz and Siemens are due simply to different manufacturing dates.....


 
  
 Maybe, maybe not. If you take a close look at the photos of the auction above you can see multiple brands with the different envelope shapes.


----------



## gibosi

mordy said:


> I have Siemens C3g tubes with the embossed logos and with the printed logos.


 
  
 Do they sound the same? Different?
  
 My embossed Lorenez and printed Siemens certainly sound different. And so the question: Different factories, Lorenz and Siemens? Or the same factory but different dates?
  
 And again, looking at the picture posted by -MisterX-, which clearly shows internal construction differences... Different factories? Or different dates?
  
 http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/9180#post_11350547


----------



## buldogge

I just received 4x Siemens today that have embossed cans (my others are printed)...I'll see if I can note any sonic differences.  
  
 These are used, and the pins either have different plating or are just a little more tarnished/worn than the others I have.
  
 I picked these up on the cheap...so I think I'll actually try to remove the cans on (2) of them.  Can anyone point me to the "best" procedure for cleanly removing the cans?  I will epoxy/glue the lower cover back in place afterwards.
  
 TIA
 -Mark in St. Louis


----------



## gibosi

buldogge said:


> These are used, and the pins either have different plating or are just a little more tarnished/worn than the others I have.
> 
> I picked these up on the cheap...so I think I'll actually try to remove the cans on (2) of them.  Can anyone point me to the "best" procedure for cleanly removing the cans?  I will epoxy/glue the lower cover back in place afterwards.
> 
> ...


 
  
 Courtesy of Hypnos1:
  
 http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/5670#post_10412030


----------



## MIKELAP

buldogge said:


> I just received 4x Siemens today that have embossed cans (my others are printed)...I'll see if I can note any sonic differences.
> 
> These are used, and the pins either have different plating or are just a little more tarnished/worn than the others I have.
> 
> ...


 
 Just use a file and  go all around the rim of the base of the tube till you go thru the thin layer of metal  its alluminum its a very soft material   and pull on centering pin comes out easily make  marks to make shure you put  the base in same holes                                                                                                                                                                                                                    
 +                                                                                                 -


----------



## buldogge

Thanks guys


gibosi said:


> Courtesy of Hypnos1:
> 
> http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/5670#post_10412030


 
  
  


mikelap said:


> Just use a file and  go all around the rim of the base of the tube till you go thru the thin layer of metal  its alluminum its a very soft material   and pull on centering pin comes out easily make  marks to make shure you put  the base in same holes
> +                                                                                                 -


 

 Thanx guys...Unfortunately, I'm an idiot...Sigh.
  
 Before worrying about removing the cans, I'm gonna have to worry about fixing (if even possible) the tubes!
  
 In my haste to score some reasonably priced spares, I didn't translate the description text (in German) and bought a set of tubes with Pin 5 removed!  Apparently this makes it perform like a C3M...?
  
 So, short of managing to solder a pin in place (they did a good removal job, unfortunately)...Is there anything else I can do to connect the cathode (I'm still tube construction illiterate for all intents and purposes).
  
 TIA
 -Mark


----------



## gibosi

buldogge said:


> Thanks guys
> 
> 
> 
> ...


 
  
 Depending on how your adapters are wired, it may not matter. The cathode is connected to both pins 5 and 7, so as long as Grid#3 (pin 2 of the C3g) is tied to pin 7, and pin 7 is, in turn, connected to pin 2 (6AK5 cathode) in the 6AK5 socket, then everything is good.


----------



## buldogge

gibosi said:


> Depending on how your adapters are wired, it may not matter. The cathode is connected to both pins 5 and 7, so as long as Grid#3 (pin 2 of the C3g) is tied to pin 7, and pin 7 is, in turn, connected to pin 2 (6AK5 cathode) in the 6AK5 socket, then everything is good.


 

 Unfortunately, according to my notes, 2+7 of the C3G are connected to 7 of the 6AK5...
  
 5 of the C3G is connected to 2 of the 6AK5.
  
 So, I could rewire my one set of adapters easily enough (the other set is epoxied)...or a little more rigged...I could run a strap wire from pin 7 of the C3G to the 5 socket of the adapter...Yes?
  
 TA
 -Mark


----------



## gibosi

buldogge said:


> Unfortunately, according to my notes, 2+7 of the C3G are connected to 7 of the 6AK5...
> 
> 5 of the C3G is connected to 2 of the 6AK5.
> 
> So, I could rewire my one set of adapters easily enough (the other set is epoxied)...or a little more rigged...I could run a strap wire from pin 7 of the C3G to the 5 socket of the adapter...Yes?


 
 Pin 7 in the 6AK5 socket is open in the EF95 setting. It is not connected to anything. So connecting pins 2 and 7 of the C3g to pin 7 of the 6AK5 accomplishes nothing. With C3g pin 5 removed, it is necessary to tie C3g pins 2 and 7 to pin 2 in the 6AK5 socket. And likely, the easiest way to do this is to use a piece of small gauge stranded wire to strap pins 5 and 7 together in your loctal socket, similar to what we used to do with 6AU6 and 6AH6.
  
 Good luck!


----------



## buldogge

gibosi said:


> Pin 7 in the 6AK5 socket is open in the EF95 setting. It is not connected to anything. So connecting pins 2 and 7 of the C3g to pin 7 of the 6AK5 accomplishes nothing. With C3g pin 5 removed, it is necessary to tie C3g pins 2 and 7 to pin 2 in the 6AK5 socket. And likely, the easiest way to do this is to use a piece of small gauge stranded wire to strap pins 5 and 7 together in your loctal socket, similar to what we used to do with 6AU6 and 6AH6.
> 
> Good luck!


 

 Both of my adapters are built that way...they were based on Hypnos1's wiring diagram...both work fine...I just tried strapping the pins but got nothing...I'll try again.
  
 -Mark


----------



## gibosi

buldogge said:


> Both of my adapters are built that way...they were based on Hypnos1's wiring diagram...both work fine...I just tried strapping the pins but got nothing...I'll try again.


 
  
 They work because it is necessary to tie pins 2 and 7 together in the adapter. But again, pin 7 in your 6AK5 socket is not connected to anything inside your amp. But since pin 5 is tied to pin 7 inside the C3g, then pin 5 connects pins 7 and 2 to the cathode in your 6AK5 socket, pin 2.
  
 You may want to tie pin 7 and pin 2 in your 6AK5 socket together to see if that works.


----------



## buldogge

gibosi said:


> They work because it is necessary to tie pins 2 and 7 together in the adapter. But again, pin 7 in your 6AK5 socket is not connected to anything inside your amp. But since pin 5 is tied to pin 7 inside the C3g, then pin 5 connects pins 7 and 2 to the cathode in your 6AK5 socket, pin 2.
> 
> You may want to tie pin 7 and pin 2 in your 6AK5 socket together to see if that works.


 

 No strapping of any kind works.  
  
 How about running pin 2 of the 6AK5 to pin 7 (or 2) of the C3G (on the adaptors I can re-wire)?  (pin 2 + 7 C3G are bridged)
  
 ???
  
 -Mark


----------



## gibosi

buldogge said:


> No strapping of any kind works.
> 
> How about running pin 2 of the 6AK5 to pin 7 (or 2) of the C3G (on the adaptors I can re-wire)?  (pin 2 + 7 C3G are bridged)


 
  
 It appears that rewiring may well be your best option. Again, you want to tie pins 2 (grid 3) and 7 (cathode) of the C3g together and then connect them to pin 2 (cathode) in the 6AK5 socket.


----------



## buldogge

gibosi said:


> It appears that rewiring may well be your best option. Again, you want to tie pins 2 (grid 3) and 7 (cathode) of the C3g together and then connect them to pin 2 (cathode) in the 6AK5 socket.


 

 So I just soldered a jumper from 5 to 7 (which is already bridged to 2) on the C3G end...checked continuity thru the adapter...checks out from pin 2 on the 6AK5 side thru to 2,5,7 on the C3G side...but...no dice...no sound.
  
 Starting to wonder about these tubes...
  
 -Mark


----------



## i luvmusic 2

I was hesitant to bid on these tubes and at the last minute i bid $50 CAD(max bid) and i got it for $34 CAD+$12 CAD shipping i think i did good.The seller said they are all NOS they all look new to me never been used and my favourite out of all 5 is the Tung-Sol Tall Bottle,GE brown base and the Sylvania WGTA these 3 tubes sound really good to my ears.


----------



## spiderking31

I just purchased a pair of telefunken EH900S type tubes, so they're coming this upcoming week  see how they are when I get them


----------



## buldogge

buldogge said:


> So I just soldered a jumper from 5 to 7 (which is already bridged to 2) on the C3G end...checked continuity thru the adapter...checks out from pin 2 on the 6AK5 side thru to 2,5,7 on the C3G side...but...no dice...no sound.
> 
> Starting to wonder about these tubes...
> 
> -Mark


 

 Any other thoughts on dealing with these tubes?  I have initiated a return thru ebay (seller doesn't offer returns, so would be trying to use the ebay guarantee)...but...would love to figure out if I am doing something wrong.
  
 If I had a loctal breadboard or a spare socket, I would build a test plug and try some different things...but...I am baffled why 2-7-5 bridged on the C3G running to 2 on the 6AK5 doesn't work!...???
  
 -Mark


----------



## TrollDragon

buldogge said:


> Any other thoughts on dealing with these tubes?  I have initiated a return thru ebay (seller doesn't offer returns, so would be trying to use the ebay guarantee)...but...would love to figure out if I am doing something wrong.
> 
> If I had a loctal breadboard or a spare socket, I would build a test plug and try some different things...but...I am baffled why 2-7-5 bridged on the C3G running to 2 on the 6AK5 doesn't work!...???
> 
> -Mark


 
 Paperclips in the B7G and jumper wires to the C3g will allow you to cobble together a sudo breakout board, that would be the only way to easily test the tube without a proper breakout board or spare socket IMHO.


----------



## buldogge

trolldragon said:


> Paperclips in the B7G and jumper wires to the C3g will allow you to cobble together a sudo breakout board, that would be the only way to easily test the tube without a proper breakout board or spare socket IMHO.


 

 Good idea TD...Keeping the wires attached will be a bit of a bear...maybe tiny alligator clipped cables.
  
 -Mark


----------



## superdux

Hi bulldogge,
  
 i could translate into German for you one time so you could explain yourself to the seller
 BTW i was lucky yesterday and snatched 2x '75 grey shields voskhod 6n23p and the seller has put up some more delicacies for you and they are very, very cheap.
 ATM he has a74, 76, 77 tubes as auctions.Just wanted to let you know.
 I was lucky getting the 75s but i keep stretching my bank account limit to the max every month, so no more 6n23ps for me anymore.Besides i already have 2x78, 1x79, 1x80, hopefully soon 2x75 and just recently a 73.
 So good luck on your buy and you will surely enjoy these beauties as they have nice detailed representation with good bass and black background.
 When i get those tubes I'll post some pics for you guys. Happy holidays from germany.
 Oh nearly forgot this is the seller, so hurry
  
 http://www.ebay.de/usr/kwtubes
  
 EDIT: of course you'll need an adapter for them to work in the LDMKIII but i've seen the Shiit Lyr uses them too but then you'll need two of a kind.


----------



## buldogge

superdux said:


> Hi bulldogge,
> 
> i could translate into German for you one time so you could explain yourself to the seller
> BTW i was lucky yesterday and snatched 2x '75 grey shields voskhod 6n23p and the seller has put up some more delicacies for you and they are very, very cheap.
> ...


 

 Hey superdux...The seller's English seems quite good.  They do not offer returns (listed on auction) but I will ask eBay to honor their guarantee.
  
 As far as those 6N23Ps...I have a MH 25.3 DAC that uses a single 6DJ8/6922...Are these worth picking up for what is essentially a pre-amp stage?  I'm currently using a Amperex (Beckman) PQ 6922.
  
 TIA
 -Mark


----------



## superdux

I've seen 73s sell for 65$ and the 75 for 159$ a piece(to be noted). You do the math. As for pre Amp stage i couldn't tell you if its worth it. I just know from the Lyr thread that these tubes are real beauties.


----------



## gibosi

buldogge said:


> Hey superdux...The seller's English seems quite good.  They do not offer returns (listed on auction) but I will ask eBay to honor their guarantee.
> 
> As far as those 6N23Ps...I have a MH 25.3 DAC that uses a single 6DJ8/6922...Are these worth picking up for what is essentially a pre-amp stage?  I'm currently using a Amperex (Beckman) PQ 6922.
> 
> ...


 
  
 I would guess that the Beckman tube was manufactured in the US? Instead of a triangle representing Philips' Heerlen, Holland, factory, it has an asterisk representing Philips' Hicksville, NY, factory? I have 1961 and 1965 New York tubes and I prefer both to the Heerland, Holland 6922 / E88CC manufactured at about the same time. However, I prefer the 1975 Voskhod 6N23P to any of these Philips tubes. But of course, my ears and my gear.


----------



## buldogge

superdux said:


> I've seen 73s sell for 65$ and the 75 for 159$ a piece(to be noted). You do the math. As for pre Amp stage i couldn't tell you if its worth it. I just know from the Lyr thread that these tubes are real beauties.


 

 Well...sounds like it's worth a try for the price.
  
 TA
 -Mark


----------



## buldogge

gibosi said:


> I would guess that the Beckman tube was manufactured in the US? Instead of a triangle representing Philips' Heerlen, Holland, factory, it has an asterisk representing Philips' Hicksville, NY, factory? I have 1961 and 1965 New York tubes and I prefer both to the Heerland, Holland 6922 / E88CC manufactured at about the same time. However, I prefer the 1975 Voskhod 6N23P to any of these Philips tubes. But of course, my ears and my gear.


 

 Hey gibosi...Yes, US manufactured, gold pins, big halo getter...1964 production.
  
 -Mark


----------



## buldogge

OK...I picked up a '74 6N23P to try in the MH 25.3.
  
 TA superdux...
  
 -Mark


----------



## Nic Rhodes

KWTubes was selling a 75 for about $13, same for the 74 I think. I have bought from him in the past and had no issues. Cheap P and P also.


----------



## i luvmusic 2

nic rhodes said:


> KWTubes was selling a 75 for about $13, same for the 74 I think. I have bought from him in the past and had no issues. Cheap P and P also.


 
 I have bought few items(switches,tubes,Caps and some solid copper wires) from the same seller he is good/quick respond and shipping.


----------



## Oskari

nic rhodes said:


> KWTubes was selling a 75 for about $13, same for the 74 I think. I have bought from him in the past and had no issues. Cheap P and P also.


 
  
 There is also the bonus that he is in EU.


----------



## DecentLevi

Hello everybody, I'm brand new to tube amps and I'm trying to sort out all my questions, in hopes that you folks can answer them - at least a few people can answer a few of my questions - and if it's already been answered it's OK to just send me a link to the page.


 I heard the Little Dot MK3 sounds warmer than the MK4, yet was still advised to go with the MK4. Is the difference just because of a different type of tubes used in MK4, or is there anything else that makes the MK4 'better'? 
_ (I prefer a fairly flat sound signature that is punchy/dynamic, slightly warm and highs that are detailed yet not harsh)_


 I have read the the Little Dot MK3 has adjustable gain switches, but I couldn't find any photos of that. Where on the unit is that switch - or is that just referring to disconnecting some of the tubes to change the gain amount?


 _Approx._ what is the average lifespan of a tube (the ones that the MK3 / 4 come with or otherwise?)


 Is anybody here familiar with the headphone amp "DarkVoice 336"? If so, how does this compare with the Little Dot amps, and which one would you recommend I may like better based upon my sound preference? _
(not important, just asking)_ 


 Does anybody have advice on which tubes I may like best, based on my sound preferences?


----------



## DecentLevi

Also, would anybody say that Little Dot MK3 / 4 amps are best only for high-impendence headphones? (For me, I have several 32 ohm cans like Beyer. DT 880 and 300 ohm cans like HD-600)


----------



## superdux

Hi DecentLevi,
  
 if you have the spare change get the MKIV it has the better parts and some guys here wrote they noted a difference for the better when changing from MKIII.
 Yes the gain switches are inside the amp, if you turn it on its backside you can see 2 switches with on/off on them.With a tiny screwdriver flatblade you can toggle them to your desire.
 As for the low ohm cans: they can be driven but it might be better getting a seperate amp for those cans if you have many of them.Though i do have positive experience with low ohm IEM that worked and sounded flawless on my MKIII.
 As i've just switched powertubes to stock again i have the impression these are not so dark as the chinese 6SN7 i recently plugged in with an adapter. As for darker driver tubes i had some M8100/CV4010/6AK5W MULLARD that were not so hot on the top and a bit darker. I think they even come with the MKIV??? I'm not sure though.
 Hope you have fun with your amp and don't make my mistake and buy from a reseller but buy directly from Davidzeze i think he's called.The guy from Littledot.You have a better garanty and warranty status with him.


----------



## MIKELAP

decentlevi said:


> Hello everybody, I'm brand new to tube amps and I'm trying to sort out all my questions, in hopes that you folks can answer them - at least a few people can answer a few of my questions - and if it's already been answered it's OK to just send me a link to the page.
> I heard the Little Dot MK3 sounds warmer than the MK4, yet was still advised to go with the MK4. Is the difference just because of a different type of tubes used in MK4, or is there anything else that makes the MK4 'better'?
> _(I prefer a fairly flat sound signature that is punchy/dynamic, slightly warm and highs that are detailed yet not harsh)_
> 
> ...


 
 Here are a few pictures .For the gain switches( page 8)  they are 2 of them for each channel on the MK3 ,under the amp in front  circled in black, towards the middle of the amp the arrows show the jumpers that you will have to move depending on the tubes you use  it will be easier to change them around if you get the long jumpers like in picture there about 1/2¨inch long with small longnose pliers its a dream.
  
 https://dl.dropboxusercontent.com/u/6037680/Little%20Dot%20MK%20III%20Reference%20Guide.pdf


----------



## DecentLevi

Thanks very much guys, I guess I would have to figure out how to change tubes from trial & error later. Anybody can mention about the average lifespan of a tube, and if it would always be necessary to change the gain settings each time I switch from a low/high impendence headphone?


----------



## DecentLevi

Hello again guys, I just wanted to ask if anybody would recommend the Little Dot MK3 over the Vali or FiiO E12 amp? I mean, would you say this amp sounds as better/worse than these other amps, and in about what way? I'm just asking because a lot of faith in these reviews would be required to buy this without first trying it.
  
 I think if I do get a Little Dot I would get MK3 to save a few bucks, and maybe try replacing some tubes to get it to sound as good as the MK4.
  
 In case this helps which amp / tube to recommend, _I prefer a fairly flat sound signature that is punchy/dynamic, slightly warm and highs that are detailed yet not harsh. _Thanks again folks!


----------



## TrollDragon

decentlevi said:


> Hello again guys, I just wanted to ask if anybody would recommend the Little Dot MK3 over the Vali or FiiO E12 amp? I mean, would you say this amp sounds as better/worse than these other amps, and in about what way? I'm just asking because a lot of faith in these reviews would be required to buy this without first trying it.
> 
> I think if I do get a Little Dot I would get MK3 to save a few bucks, and maybe try replacing some tubes to get it to sound as good as the MK4.
> 
> In case this helps which amp / tube to recommend, _I prefer a fairly flat sound signature that is punchy/dynamic, slightly warm and highs that are detailed yet not harsh. _Thanks again folks!


 
  
 Just the option of being able to tailor the sound on a Little Dot amplifier greatly surpasses the Vali and its non roll-able tubes. You could put tubes in the Little Dot that will bring it above Schiit audio quality and start entering Woo territory.
  
 The E12 is a portable solid state amp, I don't really know how you would compare apples to oranges...


----------



## Nic Rhodes

decentlevi said:


> Hello again guys, I just wanted to ask if anybody would recommend the Little Dot MK3 over the Vali or FiiO E12 amp? I mean, would you say this amp sounds as better/worse than these other amps, and in about what way? I'm just asking because a lot of faith in these reviews would be required to buy this without first trying it.
> 
> I think if I do get a Little Dot I would get MK3 to save a few bucks, and maybe try replacing some tubes to get it to sound as good as the MK4.
> 
> In case this helps which amp / tube to recommend, _I prefer a fairly flat sound signature that is punchy/dynamic, slightly warm and highs that are detailed yet not harsh. _Thanks again folks!


 
  
 I have a Fiio E12 and E12 DIY. They hardly get used (but are nice amps). Most of my phones are high impedance types so I favour amps like the LD 3 / 4. I bought a 4SE bought without any tubes so I can roll whatever I want (tubes are all cheap for these amps). It is s best with high impedance phones however. For other impedance phones my LD Mk9 and my Schiit Vali are better all rounders (the latter a hybrid). So amp choice may be down to phone driving first and foremost. In my case, most of my phones are >300 ohms types so I favour OTL valve amps. I have solid state amps, some good ones, but my heart has always been valve based.


----------



## i luvmusic 2

Deleted.


----------



## Mikkee33

Hi,
  
 I have no experience of the Mk4, however I use a Mkiii as a pre-amp and incorporate a mechanical switch box to swap between different components.
  
 It really is a fabulous amp, I have used a variety of driver tubes, my favourites are the Mullards. Power tubes have less sonic impact for me about 20% absolute max. I have used Electro Harmonix but I found the sound rather harsh and abrupt, to be fair I have little complaint with the stock tubes supplied, however they do need about 100 hours + burn in to soften.
  
 I have put my Little dot up against some very good pre-amps circa £1500, its not necessarily better but certainly on a par for the price differential.
  
 I hope this input helps your purchase decision.


----------



## DecentLevi

mikkee33 said:


> Hi,
> 
> I have no experience of the Mk4, however I use a Mkiii as a pre-amp and incorporate a mechanical switch box to swap between different components.
> 
> ...


 

 That's some good advice, thanks. Any impressions you can post on what the Mullard tubes do for the sound signature?
 And which DAC are you using?
 Thanks


----------



## Mikkee33

The Mullards give a rich sweet presentation quite laid back, they help take off the sharp digital presentaion from my Cambridge Audio CD6 which has upgraded BurrBrown op amps. I use Neotech pure silver interconnects...fantastic. My dac is a Firestone audio Spitfire Mkii not incredibly expensive but some excellent reviews which I endorse. My power amp is an Alchemist Forset mkii about £1500 when I originally bought it and still fetch around £1000. So you can see my Little Dot is with some reasonable equipment. If you are on a budget or indeed open minded check out Temple Audio I have a pair of Bantum Golds bi-amped on a secondary system. Astonishing little amps and almost as good as my Forseti. They go nicely the the Little Dot also. I probably can recommend some alternative driver tubes but off the top of my head cant remember the names. I bought a job lot of 50 off ebay few months back. Finally Headphones Sennheiser 595, good value and very open and detailed.


----------



## spiderking31

decentlevi said:


> That's some good advice, thanks. Any impressions you can post on what the Mullard tubes do for the sound signature?
> And which DAC are you using?
> Thanks


Im currently using the Yugoslavian 6HM5's and they're totally out of this world with my Sennheiser HD650's! I've also have the Voshkod 6ZH1P-EV's, and while many praise those as being one of the best, I prefer the 6HM5, as they're a laid back, detailed tube, with superb soundstage! It's what you prefer I guess. But that's my honest opinion on the best tubes you can use, especially the fact that I own 12 different tubes for the little dot! ☺️☺️


----------



## Shaffer

spiderking31 said:


> Im currently using the Yugoslavian 6HM5's and they're totally out of this world with my Sennheiser HD650's! I've also have the Voshkod 6ZH1P-EV's, and while many praise those as being one of the best, I prefer the 6HM5, as they're a laid back, detailed tube, with superb soundstage! It's what you prefer I guess. But that's my honest opinion on the best tubes you can use, especially the fact that I own 12 different tubes for the little dot! ☺️☺️




Do the 6HM5 require moving the jumpers, or simply plug and play like the Voshkod?


----------



## MIKELAP

shaffer said:


> spiderking31 said:
> 
> 
> > Im currently using the Yugoslavian 6HM5's and they're totally out of this world with my Sennheiser HD650's! I've also have the Voshkod 6ZH1P-EV's, and while many praise those as being one of the best, I prefer the 6HM5, as they're a laid back, detailed tube, with superb soundstage! It's what you prefer I guess. But that's my honest opinion on the best tubes you can use, especially the fact that I own 12 different tubes for the little dot! ☺️☺️
> ...


 
 Both the Voskhod and the 6HM5 are on EF95 setting


----------



## Shaffer

mikelap said:


> Both the Voskhod and the 6HM5 are on EF95 setting




Thank you.


----------



## DecentLevi

Hello again guys - I'm still brand new to the tubular thing.

* What is a jumper? (do I need it, and why, how do I use it, where would I get it etc.?)
* What is EF95 setting??
* I see the Little Dot MK3 & 4 amps have 2 sets of 2 tubes (4). So would I only be replacing the larger tubes, the smaller tubes, or both?


----------



## mordy

Hi DecentLevi,
  
 The general consensus on this forum is that the Yugoslavian Ei 6HM5 tubes are among the best driver tubes if you don't want to do any modifications to the MKIII - just plug and play (EF95 setting). They are inexpensive as well.
  
 To get the best information on the the tubes for the MKIII, start from the more recent posts and work backwards. There is a wealth of information available. As far as value for the dollar and versatility, I cannot think of any amp that beats the MKIII.
  
 Re life span of tubes:
  
 Most EF95 family tubes are designed to last at least 3000 hours. The old octals 5000 hours. Special editions were designed to last 10,000 hours - notably Russian tubes with DR designation (Russian EV designation = 5000 hours). GE 5 Star tubes 7,500 hours. Amperex Special Quality (SQ) and Mullard Millenium tubes 10,000 hours. Some Russian IR tubes are supposed to last only 500 hours, but that may be when they are used in the hostile environment of a tank or jet fighter.
  
 For all practical purposes the life span of the tube does not matter much, and most of us have experienced very few tubes actually getting used up. It is much more common to drop one and break it than wearing it out!
  
 Once you start the addictive game of tube rolling, chances are that you will never wear out a tube....
  
 Re power tubes they make an enormous difference if they are really good - they change the entire sonic signature of the amp. IMHO the more current they handle, the better in the LD MKIII. If you do not want to do any modifications, the best way to get good power tubes on a budget is to order adapters so that you can use 6SN7 octal tubes for power tubes. Any Sylvania or similar will sound better and give better bass than the 6H30 family of tubes.
  
 Good luck!


----------



## MIKELAP

decentlevi said:


> Hello again guys - I'm still brand new to the tubular thing.
> 
> * What is a jumper? (do I need it, and why, how do I use it, where would I get it etc.?)
> * What is EF95 setting??
> * I see the Little Dot MK3 & 4 amps have 2 sets of 2 tubes (4). So would I only be replacing the larger tubes, the smaller tubes, or both?


 
 Refer to the pictures and comments i wrote on previous page blow up picture youll see better .The circle with the arrows you see the jumpers are there you see the marking EF95  and in other circle you see  ef92 the blacks rectangular thing in those circles  are the jumpers


----------



## spiderking31

mikelap said:


> Both the Voskhod and the 6HM5 are on EF95 setting


i have a pair of Tesla 6F32's and I have a pair of Telefunken EH900S tubes coming in the next few days, as well as many other types. And they're all EF95 setting! all of these tubes are EF95 setting, and all various brands, and types


----------



## MIKELAP

page 77 is your friend you can go check there if there listed


----------



## MIKELAP

spiderking31 said:


> mikelap said:
> 
> 
> > Both the Voskhod and the 6HM5 are on EF95 setting
> ...


 
 both of them are EF95


----------



## spiderking31

Yes, they are


----------



## MIKELAP

spiderking31 said:


> Yes, they are


 
 I have some of those Tesla's as well


----------



## spiderking31

I have the Excalibur ones....not the ones with the yellow print, but with the two swords on them


----------



## TomNC

Hello. First time posting in this thread. Are there tube recommendations for LD MKiii that may extend the highs relative to the stock tubes. I have also used CV4010 and GE JAN 5654W (my favorite) tubes for extended periods of time. Common to these tubes, I dislike the clipping and somewhat fatigue highs when the LD drives my HD-650. To my ears, there is a similar tendency for LCD-3 too, though to a lesser extent due to the nature of the LCD-3.
  
 Recently I bought a McIntosh 4100 receiver and have been pleasantly surprised at the much extended ranges of the 4100. It substantially improves both the high and low ends of the HD-650. I no longer experience the clipping or hot highs from the HD-650. Sound stage is also expanded.
  
 Still I wonder I can get some tubes to open up the high frequencies of the LD. Thanks in advance for your input.


----------



## DecentLevi

> Quote:


 


tomnc said:


> ...
> Recently I bought a McIntosh 4100 receiver and have been pleasantly surprised at the much extended ranges of the 4100. It substantially improves both the high and low ends of the HD-650. I no longer experience the clipping or hot highs from the HD-650. Sound stage is also expanded.
> 
> Still I wonder I can get some tubes to open up the high frequencies of the LD. Thanks in advance for your input.


 
 Hello, sorry I'm just posting here to ask a question: Where does your MK3 come into play in the chain with your McIntosh 4100? Are you using that as a radio tuner then outputting it to your MK3, or using it the other way around as a 2nd amp connected in series after the MK3? I'm sure by sometime tomorrow you'll receive a better answer to your question - there are several experts on here 
	

	
	
		
		

		
			




  
 Also speaking of the experts on this thread; I have just a few more stupid questions for now please.
  
 * I got an email from a seller of the MK3 and he said there are two types of tubes this uses, the EF95 and 6H6PI type (big and small ones I think). So if I were to want to change the sound of the amp, would I need to replace both the big and small sets of tubes, or just one set?
  
 * I checked on page 77 and saw only about the EF95 tubes so I'm not quite sure where the 6H6PI would fit in.
  
 * I have seen the photos from MikeLap, but I still don't have the foggiest clue what a "Jumper" is, or how to use tube mods? (my hunch is this is some sort of an adapter to make other tubes fit but I wouldn't know where to begin on using it or finding tubes that fit the adapter)
  
 Thanks again!


----------



## MIKELAP

decentlevi said:


> > Quote:
> 
> 
> 
> ...


 
  To change the sound you can change power tubes and driver tubes but you will have to experiment because what sounds good to me might not sound so good to you depending on the gear you have and all .Thats why search function is very useful and reading the thread will help alot                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      The EF95, EF92  types those are driver tubes (front tubes ) the 6H6P 6H30Pi ects. those are power tubes (back tubes) there's also tubes on page one you could try out but tubes on page 77 were found to be better and most of the time cheaper but ive tried all of these tubes at one point or another its part of the fun of tube amps trying different tubes and also collecting them .                                                                                                                                                                                                                                                                                                                              Thats why mordy says to start reading from the end if you want to try the best tubes weve found so far and most of the time to get to listen to those you will need atleast adapters that you can buy on ebay but some other tubes are not plugnplay you would need a power supply and other stuff                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         The easiest i find so far to get very good sound is to use 6SN7 tubes as power tubes (back tubes) with (6SN7 to 6CG7 adapters ) and C3G tubes as driver tubes (front tubes) with adapters (C3G TO 6AK5) or you could also try 6HM5 made in yougoslavia tall bottles as driver tubes they are EF95 type tubes and they are plugnplay.these are pretty much the best tubes imo you can use with only adapters .                                                                                                                                                                                                                                                                                      Ok jumpers (picture#1 ) the arrows shows the jumpers those are situated under your amp so the board is downside up(pic#1) Theres one jumper per channel.You move jumpers by pulling on them,(black rectangular part)  the jumpers rest usually on 3 pins . Whats written in the circle pic#1) is EF95(5654) OFF AND EF92 ON its the same on otherside or channel. so you would move your jumpers to its designated side .heres a look of those 3 pins (pic below) that the jumpers goes on On my amp if i would be using  EF95 type tubes  my  jumpers would go on the 2 pins on the right side on each channel and for EF92 the 2 pins to left.  on each channel    Long jumpers are easier to change You can get them at DIGIKEY  .Hope this helps.                                                                                                                                                                                                                             
  
                                                                                                                                                                         
  

  
  
  
                                                                                                                                                                                                                                                      PICTURE #1                                                                                                            
  
                                                                                                                                                                                                                                                  6SN7 TO 6CG7 ADAPTERS           

                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           C3G TO 6AK5 adapters                                                                                                                                                                                                        
                                 
 6HM5 tall bottle


----------



## Shaffer

Mike, I ordered the Yugo 6HM5 yesterday. Will I need adapters? And if so, which? Thanks again for your time.


----------



## MIKELAP

shaffer said:


> Mike, I ordered the Yugo 6HM5 yesterday. Will I need adapters? And if so, which? Thanks again for your time.


 
 No they are plugnplay in the driver position (front) and amp should be on  EF95 setting


----------



## Shaffer

mikelap said:


> No they are plugnplay in the driver position (front) and amp should be on  EF95 setting




I genuinely appreciate the clear reply.


----------



## MIKELAP

shaffer said:


> mikelap said:
> 
> 
> > No they are plugnplay in the driver position (front) and amp should be on  EF95 setting
> ...


 
 Thanks .I just have to remember when i started with tube amps not so long ago that every little detail helped get me started


----------



## adtrance

I've perused more Head Fi threads than I care to admit and the LD threads are consistently the most helpful.  Thanks again to you guys for sharing your experience!
  
 I also wanted to comment on the differences to me on the much vaunted 6HM5s and the Voskhods.  I prefer the Voskhods over the 6HM5's because my listening tends to favor crispy highs, which the Voskhods have over the Ei tubes.  Grado with the 6HM5's are very good while HD600 gives it a bit too much midrange bloom - to my ears.  I can see how the Ei tubes are preferable to the Voskhods for a lot of folks because it does have a warmer, fatter sound.


----------



## buldogge

gibosi said:


> It appears that rewiring may well be your best option. Again, you want to tie pins 2 (grid 3) and 7 (cathode) of the C3g together and then connect them to pin 2 (cathode) in the 6AK5 socket.


 

 This is the latest thing the German seller has written (Bing translated):
  
Hi, my offer stands "old design". This means that pins are not the same with the new design. See Internet. Important: pin 2 (anode) and 3 (g3/k) are reversed! 
  
Old design C3G?  New design C3G?...News to me!
  
 http://www.radiomuseum.org/tubes/tube_c3g_newi.html
  
Just treat 2 and 3 in reverse on the adaptors???
  
TIA
-Mark in St. Louis


----------



## gibosi

buldogge said:


> This is the latest thing the German seller has written (Bing translated):
> 
> Hi, my offer stands "old design". This means that pins are not the same with the new design. See Internet. Important: pin 2 (anode) and 3 (g3/k) are reversed!
> 
> ...


 
  
 I knew about these "old" and "new" versions of the C3g, but for sure, it never occurred to me that these are what you have. I have never seen either of these versions in person, and always assumed that they were so rare, they would never popup on eBay...
  
 Anyway, grid 3 and the cathode are strapped inside the tube, so you do not have to accomplish this strapping in your adapter. In your adapter, route either pin 3 or 7, but not both, to pin 2 (cathode) in the 6AK5 socket. And strap pin 4 (c3g g2) to pin 2 (c3g plate) and route to pin 5 (plate) in the 6AK5 socket. Grid 1 and the heaters are hooked up as before, and it *should* work.


----------



## buldogge

gibosi said:


> I knew about these "old" and "new" versions of the C3g, but for sure, it never occurred to me that these are what you have. I have never seen either of these versions in person, and always assumed that they were so rare, they would never popup on eBay...
> 
> Anyway, grid 3 and the cathode are strapped inside the tube, so you do not have to accomplish this strapping in your adapter. In your adapter, route either pin 3 or 7, but not both, to pin 2 (cathode) in the 6AK5 socket. And strap pin 4 (c3g g2) to pin 2 (c3g plate) and route to pin 5 (plate) in the 6AK5 socket. Grid 1 and the heaters are hooked up as before, and it *should* work.


 

 Thanx Gibosi!...I will test with some flying wires first...
  
 -Mark


----------



## buldogge

gibosi said:


> I knew about these "old" and "new" versions of the C3g, but for sure, it never occurred to me that these are what you have. I have never seen either of these versions in person, and always assumed that they were so rare, they would never popup on eBay...
> 
> Anyway, grid 3 and the cathode are strapped inside the tube, so you do not have to accomplish this strapping in your adapter. In your adapter, route either pin 3 or 7, but not both, to pin 2 (cathode) in the 6AK5 socket. And strap pin 4 (c3g g2) to pin 2 (c3g plate) and route to pin 5 (plate) in the 6AK5 socket. Grid 1 and the heaters are hooked up as before, and it *should* work.


 

 Hey gibosi...That seems to do it!  Thanx for all your help...much appreciated!!
  
 -Mark


----------



## gibosi

Great news!
  
 By the way, do you also have the "newest" version of the C3g, the one the rest of us have? If so, it would be interesting to know how the "new" ones and the "newest" ones compare sonically.


----------



## buldogge

gibosi said:


> Great news!
> 
> By the way, do you also have the "newest" version of the C3g, the one the rest of us have? If so, it would be interesting to know how the "new" ones and the "newest" ones compare sonically.


 

 I do...all Siemens...(2) marked 'Post', (2) not...all screen printed cans.  
  
 Might be my imagination, but...these C3G "new" seem like they have a little more gain...or perhaps a little more highs/treble presentation, at the least.
  
 I'll report more after I modify the adapters and am running both, instead of the one I ran on flying wires.
  
 TA
 -Mark


----------



## TomNC

@DecentLevi
  
 Based on my experience so far, The MAC 4100 is overall a better headphone amp (using the headphone output) than the MK3 in that the former has a large envelop of dynamic ranges and larger sound stage, let alone the convenience of EQ with the buttons. But the modern amps like MK3 can resolve more details though the MAC has enough details for my ears. Thus, I either use the MAC or the MK3, but not both (with one as a preamp). Since I heard clipping from HD-650 driven by the MK3 but not by the MAC, with the same DAC (CEntrance DACport), I thought there was no point using the MK3 as a preamp.
  
 I have only limited experience with Mk3 tube rolling: change the stock power tubes to 6N6P-IR which is said to have a life of >10000 hrs.
  
 As to driver tubes, I tried a few. The Mullards tend to produce lush, warm sounds, which can be too much for my LCD-3 phones. Then I end up with GE JAN 5654W due to their balanced sound (somewhat warm but also resolving, energetic). Also, they are very cheap on ebay.
  
 Now that I start to follow this thread, more choices are open to me, but I would concentrating on HE-6 driven through speak tap of vintage receivers for a while before I invest more on MK3 tube rolling. I need to have a better understanding of whether the clipping I heard from the MK3 is determined by the design of the MK3 or the tubes I have used.


----------



## mordy

Man, I am learning new things all the time... So we have C3g old and C3g new. Let's throw in some more variants:
  
 C3b  4V/1.1.A





  
 C3c 4V/1.1A




  
 C3d 18V/0.24A




  
 C3e 18V/0.24A
  




  
 C3f 18V/0.24A
  




  
  
  




  
 C3g 6.3V/0.37A This is the one we all use
  




  
  
 C3g/S 6.3V/0.37A. When the final factory-tests of a C3g revealed a transconductance equal or higher than 105% of the nominal value ( 14000 µmhos), these tubes were marked with the suffix /s. The S is handwritten on the tubes (see below). These are the ones I use - great driver tubes.
  




  
 C3m 20V/0.125A
  




  
 C3o 6.3V/0,4A
  




 i think that this tube has similar electrical characteristics to the C3g but a different pinout (same pinout as C3m).
  
 I am only aware of amps that use the C3g and C3m tubes. Does anybody have any experience with the other variants?
  
 There are a few more C3 tubes in the alphabet soup, but they are not pentodes and totally different tubes as far as I know.


----------



## mordy

Hi TomNC,
  
 I may not have understood your post, but you state that you heard clipping using the LD MKIII amp with your headphones. I have clipping many times since I try to turn up the volume on the MKIII as much as I can to get better sound when I use it as a preamp. Different recordings, different tubes and different input sources can produce clipping. The LD MKIII can accommodate tubes that can have amplification factors varying from 2 to 100. The simple remedy is just to turn down the volume control until the clipping disappears.
  
 If the distortion does not disappear after turning down the volume, it is most likely a faulty recording.
  
 Is there some other factor here that eluded me?


----------



## TomNC

@mordy
  
 Thanks for discussion. I am pretty sensitive to clipping and hardened bass. But a considerable portion of music I listen to are rock songs which need certain levels of loudness for impact. With the LD MK3, it often occurs that while the vocals are at right volume I like but some instruments are already hot. This is a primary factor that I sold my Grado RS1i though there are many things I like about the Grado. In comparison, listening from the MAC 4100, the highs can extend a large range without signs of clipping. With the same loudness, the MK3 is far more prone to clipping than the MAC.


----------



## SonicTrance

That's a lot of C3 tubes Mordy! I only knew about the last three, interesting.


----------



## gibosi

mordy said:


> C3o 6.3V/0,4A
> 
> 
> 
> ...


 
  
 And of all the other C3 variants, the C3o is the most suitable for use in our Little Dots. Considering that buldogge is now an expert at building adapters, perhaps he will turn his eyes to a pair of these next.


----------



## buldogge

gibosi said:


> And of all the other C3 variants, the C3o is the most suitable for use in our Little Dots. Considering that buldogge is now an expert at building adapters, perhaps he will turn his eyes to a pair of these next.


 

 Hahaha...I trolled eBay this morning looking for these...prices are no different and there are less of them.  Seems to be a lot of C3Ms out there...
  
 If anyone sees the C3G Neu type for sale (missing pin 5), please let me know...I do have (2) back-ups already though, luckily.
  
 -Mark


----------



## Audiofanboy

Hi everyone! Sorry again for my long absence... I'd been amp-less for over a year (and away from my home country) and couldn't follow the new trends on this thread, so there was little point in me posting here. But I always kept reading the thread to keep up with the new ideas!
  
 I'm finally getting my amp back next week (my folks are coming to visit me in Japan and bringing most of the gear I left behind with them) so I'm back in the game! After reading rb2013's epic 6922 shootout, I bought an $8 holy grail Reflektor 1975 6N23P to celebrate; that should be with me next week too! I'll see how they fare against the Amperex pinched waists.
  
 But who still uses 6922 here huh? None of the cool kids, that's for sure...
  
 So I need to try some C3G in my amp first. I don't really have time lately to be building adapters and stuff, so here's a question: what's the best way to get 6AK5-C3G adapters? Get them from those shady Chinese sellers on ebay? Wait until some kind soul puts up a classified? Or should I buy all the parts and try making them myself?
  
 Another thing I'm wondering about is power tubes. I know everyone says using 6AS7 as power tubes is a huge step-up and glorious and all, but for the time being I'll be using the MK IV as a preamp, so I don't really need all that power. Do you think it's worth getting/making adapters and buying a separate power supply for those too?
  
 Sorry about all the questions right off the bat. I feel like a newbie haha... But I should be posting more often I think, I've missed the whole tube rolling thing too much for a year!


----------



## gibosi

audiofanboy said:


> Hi everyone! Sorry again for my long absence... I'd been amp-less for over a year (and away from my home country) and couldn't follow the new trends on this thread, so there was little point in me posting here. But I always kept reading the thread to keep up with the new ideas!
> 
> I'm finally getting my amp back next week (my folks are coming to visit me in Japan and bringing most of the gear I left behind with them) so I'm back in the game! After reading rb2013's epic 6922 shootout, I bought an $8 holy grail Reflektor 1975 6N23P to celebrate; that should be with me next week too! I'll see how they fare against the Amperex pinched waists.
> 
> ...


 
  
 It's great to have you back! 
  
 The 75 Reflektor 6N23P is one of my top tubes. My other favorite 9-pin double triodes are E80CC (the old 50's Eindhoven and Hamburg and the early 1970's US-made) and the E182CC (1970's US-made).
  
 I personally have had very good luck with the Chinese-made C3g adapters and see no reason not to get a pair. These ready-made adapters will enable you to quickly get a feel for the sound of the C3gs, which I think is the best we can get in the LD. After spending some time with my Glenn OTL, I have come to the conclusion that the LD bias points are much better suited to the C3g than they are to 6SN7, for example.
  
 And since I have the 1+, I will have to defer to others about power tubes....


----------



## MIKELAP

audiofanboy said:


> Hi everyone! Sorry again for my long absence... I'd been amp-less for over a year (and away from my home country) and couldn't follow the new trends on this thread, so there was little point in me posting here. But I always kept reading the thread to keep up with the new ideas!
> 
> I'm finally getting my amp back next week (my folks are coming to visit me in Japan and bringing most of the gear I left behind with them) so I'm back in the game! After reading rb2013's epic 6922 shootout, I bought an $8 holy grail Reflektor 1975 6N23P to celebrate; that should be with me next week too! I'll see how they fare against the Amperex pinched waists.
> 
> ...


 
  First of all welcome back .man.  Those adapters from China are right around the corner from you shouldnt take long to get them personnally i made my adapters but of course its less trouble to buy them  .About the 6AS7 im shure mordy is going to  encourage you to go for it .i use 6as7 but with a couple of WooAudio amp i have love the look of those tubes .For power tubes on the MK3 these days i use 6SN7 tubes with adapters  sounds good .Take it easy .


----------



## Audiofanboy

Wow, as quick as ever! Thanks for your answers!
  
 So I guess I'll just bite the bullet and eventually get a pair of those Chinese adapters, and save myself all the DIY trouble... Just one question to the MK IV or IV SE users: do these adapters fit through the brass rings? I have a faint memory I read they didn't...
  
 Now I just have to find some nice C3Gs to go with those. ebay seems to be running out of cheap ones too. Anyone want to part with a pair?
  
 Quote:


gibosi said:


> It's great to have you back!
> 
> The 75 Reflektor 6N23P is one of my top tubes. My other favorite 9-pin double triodes are E80CC (the old 50's Eindhoven and Hamburg and the early 1970's US-made) and the E182CC (1970's US-made).
> 
> ...


 
  
  


mikelap said:


> First of all welcome back .man.  Those adapters from China are right around the corner from you shouldnt take long to get them personnally i made my adapters but of course its less trouble to buy them  .About the 6AS7 im shure mordy is going to  encourage you to go for it .i use 6as7 but with a couple of WooAudio amp i have love the look of those tubes .For power tubes on the MK3 these days i use 6SN7 tubes with adapters  sounds good .Take it easy .


----------



## superdux

hi Audiofanboy,
  
 yes i'd also like to know how the 75s compare to your Amperex pinched waists because i couldn't afford them thats why I'm eager to listen to the 75s grey shield kwtubes just sent me. I'm rolling a 73 ATM. And yes i concur with Gibosi when he says he hasn't heard anything better than the C3Gs. But hopefully i will also be able to claim the Voskhods as so called Holy Grails.
 As for those chinese adapters i had them fail on me twice so i would consider asking someone tech savy (looks around in the forum) if he can build you some. I can only talk of the one Chinese seller who's name I forgot.(something with happy in it).
 Oh and i stated the prices i saw those 75 grey shield 6N23P Voskhods go for and i have to correct myself: that was 159$ for a matched pair.


----------



## Audiofanboy

But even if the "HG" 6N23P tube was better than the 6922 PW, I think I would still keep the PW, as they really do something no other tube I've owned does. rb2013 talked about "flow", the ability to draw you in a magical musical world for hours on end, and the PW did that better than any other tube. Still, I'm really curious about the 6N23P!
  
 I guess I got lucky about the price. I just read rb2013's shootout, was like "oh, let's take a look on ebay and have ourselves a good laugh" and bam, found one tube for 8 bucks... Just goes to show.
  
 I see what you mean about those ebay adapters. Indeed one seller, happy something, sells adapters made from chopped up tubes, while the other seller seems more legit.


----------



## Shaffer

mikelap said:


> First of all welcome back .man.  Those adapters from China are right around the corner from you shouldnt take long to get them personnally i made my adapters but of course its less trouble to buy them  .About the 6AS7 im shure mordy is going to  encourage you to go for it .i use 6as7 but with a couple of WooAudio amp i have love the look of those tubes .For power tubes on the MK3 these days i use 6SN7 tubes with adapters  sounds good .Take it easy .




Mike, are the 6SN7s plug and play with the adapters on a LDIII, or is there more involved?


----------



## buldogge

shaffer said:


> Mike, are the 6SN7s plug and play with the adapters on a LDIII, or is there more involved?


 
  
 Plug and play with adapters...You may need to use socket savers as well if you have a MK III and still have the brass rings.
  
 -Mark in St. Louis


----------



## mordy

Hi Audiofanboy and welcome back!
  
 As far as I know, the MKIV has brass cages that are easily removable and so no need for socket adapters (which are required to make the adapters fit within the brass rings on the MKIII - those brass rings are quite difficult to remove).
  
 IMHO the addition of 2.5A power tubes changes the entire presentation of the LD amp, and is a must if you want to explore the full potential of this great amp. The difference is enormous, not subtle, like the difference between grape juice and a good wine.
  
 You will need a 15A PS and a 15A voltage regulator. Here in the US you can buy a computer PS 400-500W on sale for around $30; a 15A voltage regulator can be found on Ebay for $13 or less. (if you can swing it, a audiophile grade PS supposedly will be quieter and may have less hum).
  
 You could look on German Ebay for deals on C3g tubes - Good Luck!


----------



## MIKELAP

audiofanboy said:


> Wow, as quick as ever! Thanks for your answers!
> 
> So I guess I'll just bite the bullet and eventually get a pair of those Chinese adapters, and save myself all the DIY trouble... Just one question to the MK IV or IV SE users: do these adapters fit through the brass rings? I have a faint memory I read they didn't...
> 
> ...


 
 One word of advice before inserting your C3G tubes in the adapters first try to enlarge the pin holes and where the centering pin goes in the adapter you might have to push the tab in the center of  the adapter back so  the tube slides in better. These tubes   are very fragile dont wiggle them when inserting them in the pin wholes,because  i and a few other guys ended up with a cracked tubes. Also you have an mk4 if i remember so you wont need socket extenders to clear the rings it would be the same if you would try the 6SN7 tubes as power tubes because adapter are to big for mk3 rings but in my case i cut them out .                                                                                                                                                                                                                                                                                                 These are the adapters i made for the c3g's and here a pic with the MK3 and  6sn7  and if you ever decide to build them loctal sockets are available but it all depends what you want to use for the body i used copper fittings 1¨x 1/2¨inch here's a tutorial i made on page 553 post#8295 and a tutorial hypnos1 made on page 544post# 8157   and these loctal sockets are still avaible on ebay i bought some look to be a better quality than the chinese sockets   and also using a little screw driver to remove the C3G from sockets personnally  i leave them on dont want to risk it .Have fun   here's link to loctal sockets in case you want to make them    http://www.ebay.com/itm/Ceramic-Loctal-8-B8G-Sylvania-1938-socket-12G1L-12P17L-2G27L-2P29L-4P1L-/381087439551?pt=LH_DefaultDomain_0&hash=item58ba94dabf


----------



## bharat2580

after a few rollings, i came to a conclusion from the tubes i own
  
 the E92 Mullards + russian 6n6p-i are the best combo for me. i guess it depends on the source i use the Ibaso DX90 line out to feed the LD mk III
  
 i also own the  6n6p-ir and the voskhods and a few more.


----------



## hypnos1

Hi guys.
  
 After the interesting musings on different C3gs, thought I'd take gibosi's invitation to try some very reasonably-priced NOS Lorenz with gold pins.
  
 I won't be able to see how they compare to the Siemens 'S' versions just yet - it's back to adapter making for my Elise...thought I'd just about finished this (very time-consuming!) game, lol!...(gibosi, you have a lot to answer for mon ami!! 
	

	
	
		
		

		
			





...but I must admit I am really curious to hear them after your own findings).
  
 In the meantime just thought you might like to see the insides of them cheek to cheek - Lorenz to the left.
  

  

  
 As you can see, quite a few differences between them...so different factories? - or just different Siemens manufacturing periods?...???
  
 Cheers!


----------



## spiderking31

EH900S Telefunken tubes, which run in EF95 setting...these are the most detailed, best tube I have ever encountered! I have the Voshkod 6ZH1P-EV's and the Yugoslavian 6HM5's among many other different tubes, and these here are the most detailed tube EVER!!! This is true audio nirvana IMHO  don't believe me??? Order a pair, which you'll find these on eBay, but they're pretty hard to find though, as these were made in the 1950's ☺️☺️ Take my word on these....if you don't believe me, then stick with you're voshkods...you've been told which is the best tube....


----------



## TrollDragon

> <Snip>
> *if you don't believe me, then stick with you're voshkods...you've been told which is the best tube....*
> </Snip>


 
 Dude, keep the arrogance for your FB group...


----------



## hypnos1

spiderking31 said:


> EH900S Telefunken tubes, which run in EF95 setting...these are the most detailed, best tube I have ever encountered! I have the Voshkod 6ZH1P-EV's and the Yugoslavian 6HM5's among many other different tubes, and these here are the most detailed tube EVER!!! This is true audio nirvana IMHO  don't believe me??? Order a pair, which you'll find these on eBay, but they're pretty hard to find though, as these were made in the 1950's ☺️☺️ Take my word on these....if you don't believe me, then stick with you're voshkods...you've been told which is the best tube....


 
  
 I take it you haven't yet tried the C3g?...


----------



## buldogge

spiderking31 said:


> EH900S Telefunken tubes, which run in EF95 setting...these are the most detailed, best tube I have ever encountered! I have the Voshkod 6ZH1P-EV's and the Yugoslavian 6HM5's among many other different tubes, and these here are the most detailed tube EVER!!! This is true audio nirvana IMHO  don't believe me??? Order a pair, which you'll find these on eBay, but they're pretty hard to find though, as these were made in the 1950's ☺️☺️ Take my word on these....if you don't believe me, then stick with you're voshkods...you've been told which is the best tube....


 
  
 These are very similar to 6BY6...which I personally found just "ok".  The 6HM5/6HQ5, CV8083, and 6EW6 all trumped these...not to mention the C3G obviously.
  
 If you like these tube types, I have a wide variety of these, 6EW6, 6DK6, etc to try for cheap...
  
 -Mark in St. Louis


----------



## SonicTrance

hypnos1 said:


> Hi guys.
> 
> After the interesting musings on different C3gs, thought I'd take gibosi's invitation to try some very reasonably-priced NOS Lorenz with gold pins.
> 
> ...


 
 Those are some beautiful tubes=) Very nice photos!


----------



## superdux

Hi Hypnos, nice pics there! What have you been up to lately? Haven't seen you around!
 After reading the 6922 shootout i was lucky to get one 6N23P single wire getter post 75 grey shield, i think the one mentioned in that thread. I just popped it in and was surprised of the more forward details and its filigree character which i have noticed gives a tube an audiophile character.The C3G holds up to it easily so i am pleased with my momentary rather cheap tube setup for the LDMKIII.
  
 Mentioned Thread
  
 http://www.head-fi.org/t/761078/6922-tube-review-17-top-6922-6n23p-e88cc-cca-7308-e188cc-tubes#post_11464856


----------



## hypnos1

sonictrance said:


> Those are some beautiful tubes=) Very nice photos!


 
  
 Thanks -MX-...do these Lorenz with gold pins look any different inside to yours?
  
 I must admit, the more I look at them the more I'm inclined to think they are indeed a different factory to the Siemens...unless Siemens decided on MAJOR changes to their design! There are so many glaring differences...
  


superdux said:


> Hi Hypnos, nice pics there! What have you been up to lately? Haven't seen you around!
> After reading the 6922 shootout i was lucky to get one 6N23P single wire getter post 75 grey shield, i think the one mentioned in that thread. I just popped it in and was surprised of the more forward details and its filigree character which i have noticed gives a tube an audiophile character.The C3G holds up to it easily so i am pleased with my momentary rather cheap tube setup for the LDMKIII.
> 
> Mentioned Thread
> ...


 
  
 And thanks to you too, superdux.
  
 Have been on hols and things, but also I'm ashamed to say most of my energies are no longer with my long-loved MKIV SE - my new Elise has ousted her big time!! 
	

	
	
		
		

		
		
	


	




 
	

	
	
		
		

		
		
	


	




...So she is 'mothballed' for the moment (and I can still hear her pining, lol...). But she still holds a fond place in my heart...
	

	
	
		
		

		
		
	


	




...
  
 Yes, those 6N23P sure are VERY good tubes...but for me they just can't match my beloved C3gSs - as you may well have gathered by now I am TOTALLY besotted with them! 
	

	
	
		
		

		
		
	


	




...
  
 Shall continue to keep an eye on this thread though...


----------



## hypnos1

audiofanboy said:


> But even if the "HG" 6N23P tube was better than the 6922 PW, I think I would still keep the PW, as they really do something no other tube I've owned does. rb2013 talked about "flow", the ability to draw you in a magical musical world for hours on end, and the PW did that better than any other tube. Still, I'm really curious about the 6N23P!
> 
> I guess I got lucky about the price. I just read rb2013's shootout, was like "oh, let's take a look on ebay and have ourselves a good laugh" and bam, found one tube for 8 bucks... Just goes to show.
> 
> I see what you mean about those ebay adapters. Indeed one seller, happy something, sells adapters made from chopped up tubes, while the other seller seems more legit.


 
  
 Hey AFB...have only just noticed you're back - sorry and WELCOME HOME!!
  
 As you're the one who originally put me on the track of the C3g you have NO CHOICE but to go for them, lol! 
	

	
	
		
		

		
		
	


	



  
 And with ebayer tubemalls selling the adapters (which look infinitely better than 'happyDIYetc.!) for $36 a pair I would save yourself the trouble...but as Mikelap says, be so careful when inserting/removing the tubes...it cost me also 2 rather expensive NOS 'S's  
	

	
	
		
		

		
		
	


	




. And as he also says, if all is working OK...KEEP 'EM IN!... only remove them if ABSOLUTELY necessary...they must go in/come out STRAIGHT...NO 'WORKING' to-and-fro at all...


----------



## SonicTrance

hypnos1 said:


> Thanks -MX-...do these Lorenz with gold pins look any different inside to yours?
> 
> I must admit, the more I look at them the more I'm inclined to think they are indeed a different factory to the Siemens...unless Siemens decided on MAJOR changes to their design! There are so many glaring differences...


 
 To my eyes, the insides look identical. Can't see any difference. My Lorenz were really dirty under the cover though. I had to clean them. Have you cleaned yours?


----------



## hypnos1

sonictrance said:


> To my eyes, the insides look identical. Can't see any difference. My Lorenz were really dirty under the cover though. I had to clean them. Have you cleaned yours?


 
  
 Luckily mine were NOS and absolutely pristine...inside and out. Am really looking forward to seeing how they sound...will update as soon as I can get those darned adapters made!!


----------



## SonicTrance

hypnos1 said:


> Luckily mine were NOS and absolutely pristine...inside and out. Am really looking forward to seeing how they sound...will update as soon as I can get those darned adapters made!!


 
 Mine were also NOS but with dirty glass under the cover.


----------



## Oskari

sonictrance said:


> My Lorenz were really dirty under the cover though.


 
  
 With what?


----------



## SonicTrance

oskari said:


> With what?




I don't know. Must be something from the factory obviously. The glass looked " muddy" instead of clear if you know what I mean. I should have taken a pic of it. Had to use vinegar to get them clean, lol.


----------



## Oskari

Some sort of grease then?


----------



## SonicTrance

oskari said:


> Some sort of grease then?




Yeah, mixed with dust. That's the best way I can describe it.


----------



## SonicTrance

I recently rolled these Mullard 6080's in my new mkvi+. And they were very noisy, but dead quiet in the mkivse which isn't even made to run those type of tubes. I don't get it
	

	
	
		
		

		
		
	


	




 
  
 It's these tubes: http://www.ebay.com/itm/311154206725?_trksid=p2060353.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT


----------



## gibosi

sonictrance said:


> I recently rolled these Mullard 6080's in my new mkvi+. And they were very noisy, but dead quiet in the mkivse which isn't even made to run those type of tubes. I don't get it
> 
> 
> 
> ...


 
  
 I would say the MK4 runs 6AS7-type tubes rather "gently". These tubes were designed to run at a significantly higher plate voltage than the MK4 can provide. And therefore, in your MK4, less than perfect tubes can often sound very good. On the other hand, your MK6, which is biasing them them properly, is running them "harder". And typically, tubes that are run hard tend to reveal their imperfections...
  
 However, that said, the noise you are hearing could very well not be due to any imperfections. It is my experience that these tubes often quiet down after 50 or more hours. So I would suggest that you don't give up on using them in your MK6 quite yet. Give them some time.


----------



## mordy

Hi MisterX,
  
 Could you comment on the difference in sound between the MKIVSE and the MKVI?
  
 Also, how does the MKIV sound with the 6080 tubes?


----------



## SonicTrance

gibosi said:


> I would say the MK4 runs 6AS7-type tubes rather "gently". These tubes were designed to run at a significantly higher plate voltage than the MK4 can provide. And therefore, in your MK4, less than perfect tubes can often sound very good. On the other hand, your MK6, which is biasing them them properly, is running them "harder". And typically, tubes that are run hard tend to reveal their imperfections...
> 
> However, that said, the noise you are hearing could very well not be due to any imperfections. It is my experience that these tubes often quiet down after 50 or more hours. So I would suggest that you don't give up on using them in your MK6 quite yet. Give them some time.


 
 That makes a lot of sense. Thanks gibosi =)


----------



## SonicTrance

mordy said:


> Hi MisterX,
> 
> Could you comment on the difference in sound between the MKIVSE and the MKVI?
> 
> Also, how does the MKIV sound with the 6080 tubes?


 
 I'd say that they sound very similar when using the SE output on the vi+, if you can find a way to get rid of the noise from that output. But as soon as I had re-terminated my cans to balanced 4-pin XLR the difference was huge. Much bigger soundstage and tighter bass and detail. Everything is better really.
  
 The mkivse sounds very good with the Mullard 6080's. A bit more tube sounding and warmer than the 6H5C's I got. Good match with the C3GS's.


----------



## MIKELAP

sonictrance said:


> I recently rolled these Mullard 6080's in my new mkvi+. And they were very noisy, but dead quiet in the mkivse which isn't even made to run those type of tubes. I don't get it
> 
> 
> 
> ...


 
 Somebody on the Woo thread tried those from Langrex and his were noisy to


----------



## SonicTrance

mikelap said:


> Somebody on the Woo thread tried those from Langrex and his were noisy to


 
 Hm, interesting. It's to bad that they're noisy cause I like the sound signature. I guess I have to give them more time like gibosi advised.


----------



## MIKELAP

sonictrance said:


> mikelap said:
> 
> 
> > Somebody on the Woo thread tried those from Langrex and his were noisy to
> ...


 
 Guy im refering to is BADAS in Woo thread i know he has had them for 1 month or so ask him if he has many hours on them.he's on this page                                                                                                                     http://www.head-fi.org/t/428570/woo-audio-amp-owner-unite/33345


----------



## SonicTrance

mikelap said:


> Guy im refering to is BADAS in Woo thread i know he has had them for 1 month or so ask him if he has many hours on them.he's on this page                                                                                                                     http://www.head-fi.org/t/428570/woo-audio-amp-owner-unite/33345


 
 Thanks!
 Though the ones he has does look different than mine. Mine doesn't have the Mullard "shield" branding. It looks like they're selling different tubes on ebay vs their website
	

	
	
		
		

		
		
	


	




 Or maybe it's just the branding on the tubes that's different. They're also £5 cheaper on their website, lol.


----------



## gibosi

sonictrance said:


> Thanks!
> Though the ones he has does look different than mine. Mine doesn't have the Mullard "shield" branding. It looks like they're selling different tubes on ebay vs their website
> 
> 
> ...


 
  
 Mullard/Philips made these beginning in the 1950s and on into the 1970s, so there is some variation over time, and as one would expect, there are also sonic differences.


----------



## MIKELAP

sonictrance said:


> mikelap said:
> 
> 
> > Guy im refering to is BADAS in Woo thread i know he has had them for 1 month or so ask him if he has many hours on them.he's on this page                                                                                                                     http://www.head-fi.org/t/428570/woo-audio-amp-owner-unite/33345
> ...


 
 The ones i bought were cheaper on website to


----------



## MIKELAP

Was reading a review of the LD MK3 from 2013 in it the reviewer was saying in the cons department and i quote ¨ May run into some restrictions when looking to tube roll¨      Really ! lol.


----------



## DecentLevi

Hello guys, I just wanted to give a quick shout-out to say thank you for your advice and explanations earlier. I didn't mean to 'leave you high and dry', but I'm just dealing with some stuff these days. I'll chat later with you all about these cool tubes & stuff.


----------



## SonicTrance

mikelap said:


> Was reading a review of the LD MK3 from 2013 in it the reviewer was saying in the cons department and i quote ¨ May run into some restrictions when looking to tube roll¨      Really ! lol.


 
 Haha, lol =)


----------



## DecentLevi

Hello guys, does anybody have any other suggestions for a DAC that seems to pair well with the Little Dot MK3?
  
 I've read your advice on the Firestone audio Spitfire Mkii and Peachtree Dac It X but I'm hoping to get closer to about $150 (or a pricier one if used). I want a DAC that has good soundstage / instrument placement and detail retrieval and I'm hoping to do better than the Modi 2.
 Thanks again!


----------



## Shaffer

decentlevi said:


> Hello guys, does anybody have any other suggestions for a DAC that seems to pair well with the Little Dot MK3?
> 
> I've read your advice on the Firestone audio Spitfire Mkii and Peachtree Dac It X but I'm hoping to get closer to about $150 (or a pricier one if used). I want a DAC that has good soundstage / instrument placement and detail retrieval and I'm hoping to do better than the Modi 2.
> Thanks again!




AQ Dragonfly.


----------



## gibosi

sonictrance said:


> Though the ones he has does look different than mine. Mine doesn't have the Mullard "shield" branding. It looks like they're selling different tubes on ebay vs their website
> 
> 
> 
> ...


 
  
 Ebay listing #171753209145 is for a pair of Mullard 6080 from the middle 1960's, about ten years earlier than the ones pictured above. However, I can't say if they sound different, as I don't have the newer tube in my collection...


----------



## SonicTrance

I've got a pair of these Psvane CV181-T's and I really like them. Compared to the UK-6SN7's they're a little warmer with more more bass and fuller sound. These are only "classic grade"


----------



## hypnos1

sonictrance said:


> I've got a pair of these Psvane CV181-T's and I really like them. Compared to the UK-6SN7's they're a little warmer with more more bass and fuller sound. These are only "classic grade"


 
  
 Before the leap to 6AS7G tubes as powers in  my MKIV SE, I found the PsVane CV181 TIIs (premium matched) to be excellent, and extremely good as drivers in my Elise (before I managed to get the C3gSs working in her, that is! 
	

	
	
		
		

		
		
	


	




...).


----------



## hypnos1

Apologies for the LD not being the showcase here, but following on from my (and gibosi's) trialling of the gold-pin Lorenz C3g an interesting comparison to the Siemens 'S' version is emerging.
  
 Although I still don't have many hours on them for proper judgement, my own preliminary findings echo gibosi's - in that they appear to have fairly different sound signatures...viz the Siemens are 'brighter' and somewhat more forward in presentation - with the usual necessary caveat re the rest of the system, of course. Especially with regard to headphones used...this is where I personally prefer the Siemens, given my Beyer T1s. The extended treble and more prominent micro-detail provide (to my ears) a more open and 'airy' sound that the T1s take full advantage of, even though at the expense of a slight degree of soundstage depth. My HD650s just don't have the same resolving power or 3D soundstage to show this difference much, whereas the T1s do so par excellence.
  
 Both versions have the C3g magic however, and depending on the rest of the system's signature one could 'fine tune' by choosing one over the other.
  
 (Actually, I personally find the standard Siemens to veer somewhat closer to the Lorenz than its 'S' brother...but again, so much is system-dependant...).
  
 A quick pic of one in and one out of its canister (Lorenzes, that is...).


----------



## superdux

I've just seen a pricey pair of C3GS on Ebay Germany!NOS NIB!


----------



## gibosi

Just for fun, I picked up a Marconi-Osram VR102 / BL63. This tube is often called a 6F8G on steroids. It has the same pin-out as the 6F8G, but considering that it is taller, the adapter needs a longer wire so not every 6F8G adapter will work. Further, the heater draws about 1.3A. Following my rule-of-thumb, the heater supply should be about 1.5 times the draw, so I recommend at least a 2.0A source.
  
 And I am pleased to report that it lights up and plays in my Little Monster Dot. 
  
 Sylvania 6F8G on the left and Marconi-Osram VR102 on the right


----------



## mab1376

gibosi said:


> Just for fun, I picked up a Marconi-Osram VR102 / BL63. This tube is often called a 6F8G on steroids. It has the same pin-out as the 6F8G, but considering that it is taller, the adapter needs a longer wire so not every 6F8G adapter will work. Further, the heater draws about 1.3A. Following my rule-of-thumb, the heater supply should be about 1.5 times the draw, so I recommend at least a 2.0A source.
> 
> And I am pleased to report that it lights up and plays in my Little Monster Dot.
> 
> Sylvania 6F8G on the left and Marconi-Osram VR102 on the right




Interesting, can't wait to hear your impressions.


----------



## gibosi

mab1376 said:


> Interesting, can't wait to hear your impressions.


 
  
 Will do. 
  
 However, on the chance folks are thinking these might make good power tubes, similar to 6SN7 and 6F8G, the LD internal heaters are just not up to the task. An external heater circuit will be necessary, with a capacity of about 4.0A for a pair. But of course, if someone is already using 6AS7/6080, they are good to go.
  
 I am using one tube as a driver in a LD1+ and later, I will roll it into a Glenn OTL.


----------



## hypnos1

Well folks, once again I am dumbfounded by how the C3g family just keep on heaping one surprise on another.
  
 After my less-than-enthusiastic last post re. the Lorenz (gold pins), I must eat humble pie...and lots of it!!
  
 I know it was early days for trying to make any meaningful assessment, but I was going by how previous new Siemens 'S' tubes performed at a similar stage - BIG mistake! The early emissions with both Lorenz in place were very disappointing, to say the least - James Taylor's voice in "You've got a friend" was hardly recognisable as James Taylor, lol!! And as for trying to handle VERY complex instrumentals and voice (viz. Mike Oldfield's mad "Heaven's Open" track!)...forget it!
  
 But with a good few more hours on them these tubes have changed/improved more than any other driver I have ever encountered in such a relatively short period of time...quite incredible. They have opened up beautifully and the treble has moved closer to the Siemens 'S', but to not quite the same level of extension. This does indeed appear to smooth things somewhat in the treble arena, and bring the mids a bit more into play and the illusion of a tad more bass. The difference now is truly unbelievable. Although this brings a bit less 'air' to the overall sound, these changes do in fact help remedy quite well the Beyer T1 "treble spike" weak link in over-bright recordings.
 So now that I can swap around as necessary between the Siemens 'S' and the Lorenz I can get the best of both Worlds from the T1s...MAGIC  
	

	
	
		
		

		
		
	


	




  
	

	
	
		
		

		
		
	


	




 ...
  
 ps. That'll teach me to take more of my own medicine when advising people to give the C3gs a decent burn-in period...not forgetting adapters also 
	

	
	
		
		

		
		
	


	




 ...
  
 pps. Immense thanks go to gibosi for pointing me in the direction of the gold-pin Lorenzes...especially at such a good price for NOS tubes...(which I now only ever go for - too many close shaves with used tubes I'm afraid, especially with $1K worth of cans...sorry mordy!!.. 
	

	
	
		
		

		
		
	


	




 ).


----------



## gibosi

As my HD700s also have a bit of a treble spike, I find the more subdued Lorenz to be a great match in my Glenn with GEC and the slotted Bendix graphite 6080 output tubes, both of which have good highs and lots of air . And I suspect that the more forward and airy Siemens might be a very good match with the more subdued Mullard 6080, but I haven't tried this combination yet....
  
  
 Edit: OK, rolled in a pair of 1966 Mullard 6080 with Siemens C3g/s this evening for about an hour and quickly found myself listening to the music, not the equipment. 
  
 Given that the Mullard is typically considerably less expensive than the GEC and Bendix, it is my opinion that the Mullard 6080 together with the Siemens C3g/s offers a very satisfying compromise between affordability and performance.


----------



## hypnos1

gibosi said:


> As my HD700s also have a bit of a treble spike, I find the more subdued Lorenz to be a great match in my Glenn with GEC and the slotted Bendix graphite 6080 output tubes, both of which have good highs and lots of air . And I suspect that the more forward and airy Siemens might be a very good match with the more subdued Mullard 6080, but I haven't tried this combination yet....
> 
> 
> Edit: OK, rolled in a pair of 1966 Mullard 6080 with Siemens C3g/s this evening for about an hour and quickly found myself listening to the music, not the equipment.
> ...


 
  
 Hi gibosi.
  
 Very interesting...just might tempt me into trying those Mullards! (I presume those are GEC 6080s you mention...how do your 6AS7G equivs compare in the Siemens/Lorenz shoot-out?).
  
 Talking of which I am liking these Lorenz (gold pins) more by the day as they get more burn-in - they certainly remove the (occasional) need for some tinkering with the T1s to tame a bit of treble harshness. And do provide a bit more bass - in my gear at least - which would please lovers of the lower register!
 Micro detail/transients/air still not quite up to the Siemens 'S', but I just might be able to squeeze a little bit more by eliminating the adapter sockets and (as I normally do) mechanically tie the pure silver wire direct to the pins and then solder - I much prefer metal-to-metal contact wherever possible, with minimal solder inbetween...at least I can convince myself of the improvement, lol! 
	

	
	
		
		

		
			





.


----------



## gibosi

hypnos1 said:


> Very interesting...just might tempt me into trying those Mullards! (I presume those are GEC 6080s you mention...how do your 6AS7G equivs compare in the Siemens/Lorenz shoot-out?).


 
  
 I haven't rolled the GEC 6AS7 recently, so can't say for sure. As I find the GEC 6080 to be very similar, the 6AS7s are safely stored away for now.
  
 The treble with the Siemens C3g / Mullard 6080 is not quite as smooth as the Lorenz / slotted Bendix (my current default), but on the plus side, there is a bit more detail and air. I prefer the Lorenz / Bendix combination, but detail freaks may prefer the Siemens / Mullard.
  
 For those who might be interested, there are at least two, and maybe three, versions of the Mullard 6080. The short bottle on the left, with metal shields between the second and third spacers, is the first version. Mine are dated 1957. The taller bottle with a bit of smoke on the glass between the second and third spacers, is the second version. Mine are dated 1966. I have seen pictures of tubes dated into the 1970s, that look very much like the 1960's, with the primary difference being no smoke on the glass. However, I don't know if that is the only difference, so these 1970s tubes may or may not represent a third version.


----------



## SonicTrance

I just rolled in these Tung-Sol 6SL7GT's dated 1957 yesterday in my MK VI+. They don't have many hours on them yet as I bought them NOS, but I'm enjoying them so far. They have a warm and smooth sound to them.


----------



## gibosi

I didn't spend a lot of time with the 6SL7 in my LD1+, but as I recall, I liked the Tung Sol 6SU7GTY and the Sylvania Gold Brand 6SL7GT (same as the regular Sylvania JAN-CHS 6SL7WGT) the best.


----------



## SonicTrance

Update on the noisy Mullard 6080's:
  
 I decided to give them a try again in my MK VI+, this time with Tung-Sol 6SL7GT BGRP's driving them. I listened with three different headphones, HE-400i, ATH W1000X and LCD-XC. The tubes were only noisy with the W1000X. The sound however were not to my liking. Way to warm, almost muddy with little detail. I imagine they'd pair better with something like the UK-6SN7's which are "cold" and very detailed, haven't tried that though. But like I said before, they do pair nice with the C3GS's in the MK IVSE.


----------



## TomNC

About C3g to 6Ak5 converter:
  
 I am interested in trying C3g tubes with my Little Dot MKiii. I saw some C3g to 6Ak5 converters (from Hong Kong) on ebay which I suspect too large to fit the MKiii tube port.
  
 Does anybody have experience with these converters? If some other adapters are needed, any recommendations? Thanks for suggestions.
  
http://www.ebay.com/itm/2piece-Gold-plated-C3G-TO-6AK5-tube-converter-adapter/191424601510?_trksid=p2045573.c100033.m2042&_trkparms=aid%3D111001%26algo%3DREC.SEED%26ao%3D1%26asc%3D20131017132637%26meid%3D3932f0f6980a485e8bd772daa8928d77%26pid%3D100033%26rk%3D1%26rkt%3D4%26sd%3D191424601510


----------



## hypnos1

tomnc said:


> About C3g to 6Ak5 converter:
> 
> I am interested in trying C3g tubes with my Little Dot MKiii. I saw some C3g to 6Ak5 converters (from Hong Kong) on ebay which I suspect too large to fit the MKiii tube port.
> 
> ...


 
  
 Hi TomNC.
  
 Those adapters certainly look preferable to the others (happyDIY ones), but I myself haven't used them I'm afraid - make my own! But I'm sure other LD users will chime in with their advice - and also a link perhaps to the extenders you will need because of those rings (unless you do a bit of butchering as some have done!! 
	

	
	
		
		

		
		
	


	




).
  
 If you go ahead I am sure you will not be disappointed...plenty of previous posts to give you encouragement!...
	

	
	
		
		

		
		
	


	



  
 GOOD LUCK!


----------



## hypnos1

My final words (probably! 
	

	
	
		
		

		
		
	


	




) on Siemens C3g'S' v Lorenz (gold pins).
  
 After a good bit more burn-in, previous comparisons are confirmed - along gibosi's lines.
  
 But I must make one more observation that puts me personally back in the direction of the Siemens 'S' (given my own set-up). And it isn't just because I LOVE extra detail!...
 I suspect it's mostly down to the amazing Beyer T1s - on closer scrutiny, I find the Siemens bring out a greater range of subtle tones throughout the frequency range, with more treble extension and note decay...which combine to give more air and space, plus a certain "je ne sais quoi" ('tingle', I suppose). This is enough to even have me forgiving the T1s for the occasional 'wince' with bright recordings.
 But if less treble, more mids and _apparent_ bass is your thing then the Lorenz may be preferable...to each his/her own, lol! 
	

	
	
		
		

		
		
	


	




...Oh, and if you like to turn the volume up to insane levels, again the Lorenz would probably suit better!


----------



## gibosi

tomnc said:


> About C3g to 6Ak5 converter:
> 
> I am interested in trying C3g tubes with my Little Dot MKiii. I saw some C3g to 6Ak5 converters (from Hong Kong) on ebay which I suspect too large to fit the MKiii tube port.
> 
> Does anybody have experience with these converters? If some other adapters are needed, any recommendations? Thanks for suggestions.


 
  
 If you are unwilling and/or unable to remove the brass rings, then you will likely need a small 7-pin socket saver to act as an extender. I used the one from Leed's Radio:
  
 http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/6000#post_10512665


----------



## gibosi

hypnos1 said:


> But I must make one more observation that puts me personally back in the direction of the Siemens 'S' (given my own set-up). And it isn't just because I LOVE extra detail!...


 
  
 So it isn't just because you are detail freak? Really??  lol


----------



## hypnos1

gibosi said:


> So it isn't just because you are detail freak? Really??  lol


 
  
 You bet, g!! 
	

	
	
		
		

		
		
	


	




...


----------



## Shaffer

All the adapters finally came in and my LDIII is now on its third hour with 6SN7s. Wow, what a difference! Sounds like a different amplifier: more effortless, more clear, more detail, more space, more texture, and the bass of the godz (all in a comparative sense). So far, I've used mid-50s RCAs.

Clan't wait to see what Feliks Audio Elise will sound like. Should have it at the end of next week.


----------



## gibosi

sonictrance said:


> Update on the noisy Mullard 6080's:
> 
> I decided to give them a try again in my MK VI+, this time with Tung-Sol 6SL7GT BGRP's driving them. I listened with three different headphones, HE-400i, ATH W1000X and LCD-XC. The tubes were only noisy with the W1000X. The sound however were not to my liking. Way to warm, almost muddy with little detail. I imagine they'd pair better with something like the UK-6SN7's which are "cold" and very detailed, haven't tried that though. But like I said before, they do pair nice with the C3GS's in the MK IVSE.


 
  
 -MisterX- makes a very good point.
  
 One can say that almost every output tube will shine in a certain amp, with complimentary drivers/headphones/ears/brains. But on the other hand, I can assure you that the most vaunted and and sought-after tubes do not sound great in every amp or with every headphone, much less, with every set of ears.
  
 So I hope no one goes chasing after one particular tube thinking it is going to be the "The Tube." And don't be too disappointed when the tube you have been fervently chasing arrives and just doesn't sound all that good. Yes, most of these highly esteemed tubes are in fact extremely good, but it can take considerable time and money to assemble all the other pieces necessary to make them truly shine.


----------



## TomNC

@gibosi; @hypnos1
  
 Thanks a lot for the great information. I hope this C3g upgrade will give a significant boost of the LD III's performance. Though I've been using mostly vintage receivers lately, the LD is my first 'serious' head-fi amp and I would not give up on it. Cheers.


----------



## gibosi

If anyone is interested in trying the Lorenz C3g, H1 and I got ours from this listing: 261863163393
  
 The vendor puts 4 tubes up at a time. And after they sell, he puts up 4 more. This has been the pattern for some time now, but of course, I have no idea how long his inventory will last.


----------



## hypnos1

gibosi said:


> -MisterX- makes a very good point.
> 
> One can say that almost every output tube will shine in a certain amp, with complimentary drivers/headphones/ears/brains. But on the other hand, I can assure you that the most vaunted and and sought-after tubes do not sound great in every amp or with every headphone, much less, with every set of ears.
> 
> So I hope no one goes chasing after one particular tube thinking it is going to be the "The Tube." And don't be too disappointed when the tube you have been fervently chasing arrives and just doesn't sound all that good. Yes, most of these highly esteemed tubes are in fact extremely good, but it can take considerable time and money to assemble all the other pieces necessary to make them truly shine.


 
  
 SPOT ON g!...I would a add a good smattering of LUCK!...viz. our collective experiences with LDs (as other die-hard members might well attest to!), and mine with the Elise 
	

	
	
		
		

		
			





...
  
 ps. Thanks for pointing others in the direction of those very reasonably-priced and magnificent gold pin Lorenz C3gs (especially considering what some are trying to charge for not-so-goodlooking tubes!).
  


tomnc said:


> @gibosi; @hypnos1
> 
> Thanks a lot for the great information. I hope this C3g upgrade will give a significant boost of the LD III's performance. Though I've been using mostly vintage receivers lately, the LD is my first 'serious' head-fi amp and I would not give up on it. Cheers.


 
  
 I should certainly hope (and expect!) so too, Tom...notwithstanding gibosi's previous wise comments - particularly re. ears (and headphones!). Luckily, a good many experienced members can vouch for the performance of the C3g, over and above my (relentless!) espousing of their virtues...
	

	
	
		
		

		
		
	


	




...
  
 Happy listening!


----------



## BGRoberts

Houston,  we HAVE TUBE sound! 
  
 The move is mostly done.   The basement and detached garage moving will stretch out over the summer,  as I find help from time to time.   Not a problem,  as my brother is moving into the old house,  and has no need for that space for some time to come. 
  
 But guess what. 
  
 In bringing out boxes from the basement,  we discovered a SECOND Little Dot MKIII!   I had purchased it used shortly before the illness,  intending to give it to an audio buddy to try out its tubey goodness,  and totally forgotten about it through the little health journey these past 20 months.   I got it hooked up to my desktop system today (PC>>Dragonfly DAC>>LDIII)  and even with the humble Koss KSC75's the sound is sweet!   I am so excited I am doing my limited version of the happy dance! 
  
 There are a few sets of driver tube that came in the deal,  so some limited tube-Rolling is also in my future. 
  
 I'm facing a series of surgeries to try and improve conditions,  so this is going to be a wonderful diversion during recovery periods. 
 Who knows,  I may one day even be able to sample some of the more exotic areas y'all have been pioneering. 
  
 I will eventually get to testing out the other amp,  and my buddy may get it at some point. 
  
 I'm just so glad to be an active Little Dot enthusiast again that I had to share! 
 WOOOHOOOOO!!!


----------



## superdux

Get well soon BGRoberts! I hope you enjoy the LDMKIII just as much as we do with our C3Gs with adapters. This amp is so versatile!


----------



## siles1991

Anyone can point me in the right direction to DIY the C3G adapter? I can't seem to find it.


----------



## MIKELAP

siles1991 said:


> Anyone can point me in the right direction to DIY the C3G adapter? I can't seem to find it.


 

 Page 544 #8157or Page553 #8295


----------



## siles1991

mikelap said:


> Page 544 #8157or Page553 #8295


 
 many thanks!


----------



## SonicTrance

So, after months of searching for some Chatham 6AS7G's I finally found a pair. Only two though, so I'm trying them out in the MK IVSE. Both light up but only one plays
	

	
	
		
		

		
		
	


	




 Not happy about that. And this was the first time I bought used tubes.
  
 I also got 7 used 5998's on the way for the MK VI+. I hope I get better luck with those.


----------



## gibosi

sonictrance said:


> So, after months of searching for some Chatham 6AS7G's I finally found a pair. Only two though, so I'm trying them out in the MK IVSE. Both light up but only one plays
> 
> 
> 
> ...


 
  
 Before giving up on those Chathams, I would encourage you to scrape and clean the pins to ensure good electrical contact. Quite often, this does the trick.


----------



## SonicTrance

gibosi said:


> Before giving up on those Chathams, I would encourage you to scrape and clean the pins to ensure good electrical contact. Quite often, this does the trick.


 
 I tried that with no luck. Thanks anyway.


----------



## i luvmusic 2

WOW! 7 5998's............


----------



## SonicTrance

i luvmusic 2 said:


> WOW! 7 5998's............


 
 Yes, I need 4 of them for the MK VI+ and I got 7 used ones for about the same price as 4 NOS. According to the seller they test good so I took a shot


----------



## SonicTrance

I'm happy to report that I received the 5998's today and they all work flawlessly They sound like a big step up from the 6H5C's in my MK VI+. They sound more spacious and clean, if that makes any sense (I'm terrible at describing sound) Best of all is that they're all quiet.
  
 I even put a couple in the MK IVSE with very nice results. Can't imagine it's possible to push this little amp any further than this


----------



## Shaffer

Are 6SN7 and 6AS7G plug and play in the mkIV?


----------



## SonicTrance

shaffer said:


> Are 6SN7 and 6AS7G plug and play in the mkIV?


 
 No, you need adapters and external heater psu for the 6AS7's.


----------



## DecentLevi

Hello guys, I really hope to send this message out in a way that doesn't 'rain on your parade' because it seems the LD amps can be seriously good with tube rolling, etc.
  
 While I had plans to buy the MK4, I'm now leaning _much _closer to getting a Project Ember. This is a tube amp / solid state hybrid with only one tube yet a thicker one, also with tube rolling options of many of the same tube brands, for about the same price as the MK4, yet having about 25% more power. Has anybody else here tried the Project Ember, or heard of a comparison between it and the LD amps? If so then please do tell - there are other members of the P.E. threads that want to know how the LD compares too.


----------



## TrollDragon

decentlevi said:


> Hello guys, I really hope to send this message out in a way that doesn't 'rain on your parade' because it seems the LD amps can be seriously good with tube rolling, etc.
> 
> While I had plans to buy the MK4, I'm now leaning _much _closer to getting a Project Ember. This is a tube amp / solid state hybrid with only one tube yet a thicker one, also with tube rolling options of many of the same tube brands, for about the same price as the MK4, yet having about 25% more power. Has anybody else here tried the Project Ember, or heard of a comparison between it and the LD amps? If so then please do tell - there are other members of the P.E. threads that want to know how the LD compares too.


 
  
 I have not heard the Project Ember, but IMHO it does have a serious case of the fuglies and don't worry you are not raining on anyone's parade here...

 I am not a fan of the dust catching, wide open EMI magnet, lexan look. It probably sounds great considering it is mostly a solid state amplifier with a tube that in my opinion is there for more of a novelty purpose than functionality since it runs at a low voltage.

 I am more of a traditional all tube guy and I dislike anything that has multicolor LED's in the tube socket... So I am not looking to bring on the wrath of the Garage 1217 fanboys. But I do believe that the P.E. would be better suited for you than a LD MK IV as it seems to tick quite a few of your boxes and tube rolling in it only requires that you plug in the tube.


----------



## i luvmusic 2

Have you considered LD 1+?


----------



## DecentLevi

I've just checked it out and the LD1+ says it's more suited for low impendence 'cans, but it sure seems nice - like a tube version of the Asgard. I'm using mostly HD 650 headphones and plan to get HE-6. Maybe if the MK4 is great for those headphones I'll still get it sometime when the extra cash comes my way.


----------



## gibosi

decentlevi said:


> I've just checked it out and the LD1+ says it's more suited for low impendence 'cans, but it sure seems nice - like a tube version of the Asgard. I'm using mostly HD 650 headphones and plan to get HE-6. Maybe if the MK4 is great for those headphones I'll still get it sometime when the extra cash comes my way.


 
  
 Generally speaking, most hybrids, such as the PE, Lyr and LD1+, are better with low-Z cans than all-tube amps. Like most hybrids, the LD1+ does very well with 32-300 ohm cans. And while the LD+1 isn't all that bad with 600 ohm cans, all-tube Little Dots, such as the LDII, LDIII and LDIV are better.


----------



## i luvmusic 2

I have both the LD 1+ and MK III for my HD650,The difference between the two with 650 is that the 1+ sounds a bit brighter than the MK III.The 1+ can drive the HD650 with no problem.


----------



## gibosi

And that difference in brightness could well be the difference between the op-amp in the 1+ and the output tubes in the III. Rolling op-amps in the 1+ and output tubes in the III, in addition to the drivers, allows the sound to be tailored to suit most any taste.


----------



## i luvmusic 2

Is this the right pin out for 6n6pi?
  
 1----------A
 2----------G
 3----------K
 4----------H
 5----------H
 6----------A
 7----------G
 8----------K
 9----------S
  
 Thanks!


----------



## gibosi

i luvmusic 2 said:


> Is this the right pin out for 6n6pi?
> 
> 1----------A
> 2----------G
> ...


 
  
 Yes you have it right. And the 6N6PI has the same pin-out as a 6DJ8 and 6CG7.


----------



## i luvmusic 2

gibosi said:


> i luvmusic 2 said:
> 
> 
> > Is this the right pin out for 6n6pi?
> ...


 
 Thank You!


----------



## MIKELAP

Hey mordy do your Sylvania 6080 WB'S have a double getter on top and copper rods . Thanks


----------



## mordy

Yes, they do. Also has triple mica plates - it seems that you found the same ones I like. The double getter looks like a pair of round glasses.


----------



## i luvmusic 2

A while back i  asked about how to used a pre-amp yesterday i finished building my first DIY Passive pre amp and i connected it to all my amps.The MK III sounded a bit different it sound like the soundstage is bigger and quieter with the volume pot all the way up and using the pre amp(Glasswa#e Audio A3 Stepped Attenuator with a PRP Metal Film Resistors)Attenuator to control the volume.


----------



## i luvmusic 2

Does anybody know if RESISTORS need Burn-in?
  
 Thanks!


----------



## Bansaku

Just received my matched pair of 1966 Svetlana 6J1P-EV and GE 5654W JAN and I must say, the stock Chinese 6J1 are utter crap. So far I am mostly listening to the Svetlanas as I can only do so much swapping and listening, but I am loving the sound. Detailed, spacious, and so very clean. A good pairing for my HD598. The GEs I find to be very thick sounding with excellent impact and compliment my T 70s pretty good.
  
 I have a question. Do any of you who have the GE 5654 JAN notice that the pins are very stiff and are hard to socket? I can't get mine flush and there is a little gap between the bottom of the tube and the plate. Is this going to pose any long term problems or is a small gap ok?


----------



## gibosi

bansaku said:


> I have a question. Do any of you who have the GE 5654 JAN notice that the pins are very stiff and are hard to socket? I can't get mine flush and there is a little gap between the bottom of the tube and the plate. Is this going to pose any long term problems or is a small gap ok?


 
  
 That little gap is not a problem. Relax and enjoy.


----------



## i luvmusic 2

Anyone tried TALL BOTTLE 6SN7's Power tubes for the  LD MK's?


----------



## buldogge

i luvmusic 2 said:


> Anyone tried TALL BOTTLE 6SN7's Power tubes for the  LD MK's?


 

 What are you defining as "tall bottle"?  
  
 I have run TS "Mouse Ears:, NU Black Glass, and Ken-Rad VT-231s which are all taller than the Sylvania GTBs, I also have, for example.
  
 -Mark in St. Louis


----------



## i luvmusic 2

buldogge said:


> i luvmusic 2 said:
> 
> 
> > Anyone tried TALL BOTTLE 6SN7's Power tubes for the  LD MK's?
> ...


 
  I have a 12SN7 tall bottle and this one is taller than all of the tubes that i have,I compared them side by side i end up having 3 different height  the tallest one is this 12SN7.The problem is i only have singles of those 12SN7 tall bottles from different manufacturers.


----------



## gibosi

i luvmusic 2 said:


> I have a 12SN7 tall bottle and this one is taller than all of the tubes that i have,I compared them side by side i end up having 3 different height  the tallest one is this 12SN7.The problem is i only have singles of those 12SN7 tall bottles from different manufacturers.


 
  
 12 volt tubes? I assume you are using a 12 volt power supply?
  
 But still, I have no idea which tubes you are talking about....  Pictures are worth a thousand words.


----------



## i luvmusic 2

gibosi said:


> i luvmusic 2 said:
> 
> 
> > I have a 12SN7 tall bottle and this one is taller than all of the tubes that i have,I compared them side by side i end up having 3 different height  the tallest one is this 12SN7.The problem is i only have singles of those 12SN7 tall bottles from different manufacturers.
> ...


 
  Yes i'am using a external PS,The tall bottle are listed in ebay and they are a bit pricey than the short bottles.
 I'am not sure if it is worth the money to get those so called tall bottle.


----------



## gibosi

i luvmusic 2 said:


> Yes i'am using a external PS,The tall bottle are listed in ebay and they are a bit pricey than the short bottles.
> I'am not sure if it is worth the money to get those so called tall bottle.


 
  
 Very generally speaking, the height of the bottle should make no difference....


----------



## i luvmusic 2

gibosi said:


> i luvmusic 2 said:
> 
> 
> > Yes i'am using a external PS,The tall bottle are listed in ebay and they are a bit pricey than the short bottles.
> ...


 
 OK Thanks!


----------



## TomNC

Some impressions of update to Csg Siemens with LD MK3:
  
 Thanks to fellow head-fiers on this thread for instructions and tips for this update. So far I have been impressed by these tubes. For about $150, I consider this to be a significant and worthy update.
  
 As compared to some tubes I used previously, the C3gs produce an overall fuller sound, closer to what I get from three vintage receivers. I have been primarily using HD650 and Sony CD3000 for testing. The fullness seems to result from both an extension of dynamic range and an expansion of sound stage. For the former, the enhancement of bass is very obvious. The quality and texture of the bass are nice too. More to my pleasure, the trebles are improved too---the hotness and clipping I heard before with some other tubes are gone. This may come from both an extension of high frequency range or some roll-off or both. Anyway, I am pleased with the overall sound signature. 
  
 At this point, with the Csgs, I have no desire to explore other tubes. As some head-fiers noted, this may indeed be an, if not the, ultimate update with the LD MK3. Though I have been using headphones with vintage receivers  a lot lately, the LD with C3gs still offers some tube joy: that fresh, smooth, and 3-D sound effects. The other day I got a chance to audit a Fisher 500c. Though the unit has been restored, there were noises between the songs and during the songs. So I was not convinced that the Fisher would be a worthy and practical update to the LD (I am sure a perfect working Fisher would be much better, but it will need both significant money and good luck to get such a unit).
  
 Other observations: The C3gs, covered with metal, do not give that charming tube glow. They run pretty hot. There are some minor noises which I am not sure the source of. Could the tubes need more hours of burn-in? Or the 7-pin socket saver is not that good in construction: unclean pins and so on. I did try to scratch the pins and apply some deoxit. Maybe more cleaning is needed.
  
 Overall, I am pleased with the C3gs. They are the most significant update and improvement of the LD MK3 I have ever experienced.
  
 Edit (5/25/2015): I thoroughly scratched and deoxited the pins of both socket savers. This seems to completely get rid of the noise. The LD and C3gs sound really clean and nice now.


----------



## SonicTrance

tomnc said:


> Some impressions of update to Csg Siemens with LD MK3:
> 
> Thanks to fellow head-fiers on this thread for instructions and tips for this update. So far I have been impressed by these tubes. For about $150, I consider this to be a significant and worthy update.
> 
> ...


 
 I'm glad you like the C3G's but what power tubes are you running?


----------



## MIKELAP

tomnc said:


> Some impressions of update to Csg Siemens with LD MK3:
> 
> Thanks to fellow head-fiers on this thread for instructions and tips for this update. So far I have been impressed by these tubes. For about $150, I consider this to be a significant and worthy update.
> 
> ...


 

 If cleaning pins im shure you've read to be very careful removing tube from socket as they are very fragile and tend to break


----------



## TomNC

@-MisterX-
  
 Power tubes are 6N6P-IR. These are the only update I have had with power tubes. I got them partially for their reported longevity---10k hours.
  
@MIKELAP
  
Thanks for the reminder. The C3gs are NOS. The C3g to 6AK5 are also with new pins. It is the 7-pin socker saver that I am concerned with; the pins seems reused and tranish with residue from plastics during construction. If the noises persist for a few weeks, I will try to clean those male pins again. Last time I did not touch those female pins.


----------



## mordy

Hi TomNC,
  
 If you would get 2.5A tubes to use as power tubes, (6AS7, 6080 etc), you would get another very significant upgrade to your LD MKIII or IV. Need external power supply and special adapters etc.


----------



## mordy

Hi i luvmusic 2,
  
 I think I have three sizes of 6SN7 tubes as well - don't think that the size makes one tube sound better than another, but it could help in distinguishing which tube to buy if there are several choices from the same manufacturer, and one iteration may sound better.
  
 There is a lot of hype out there from professional sellers, claiming that this color base or this size, or this special treatment of the tube, make for the best sounding tubes. The truth is that some of the best sounding tubes are inexpensive and plentiful, but of course, they don't give you any bragging rights....
  
 Since each channel is completely independent from the other in the LD, you could run as 12SN7 and a 6SN7 together as power tubes, with the appropriate external voltage supply for the 12SN7. Wouldn't worry about running different brands together either. Sometimes running two different tubes will produce a synergy that is better sounding than a pair of the same tube.


----------



## TomNC

@mordy
  
    Thanks for raising the bar again! One step at a time. I'll come back to your suggestion at a later date.


----------



## SonicTrance

mordy said:


> Hi TomNC,
> 
> If you would get 2.5A tubes to use as power tubes, (6AS7, 6080 etc), you would get another very significant upgrade to your LD MKIII or IV. Need external power supply and special adapters etc.


 
 +1
 Your C3G's will truly come to life with the appropriate power tubes


----------



## hypnos1

tomnc said:


> Some impressions of update to Csg Siemens with LD MK3:
> 
> Thanks to fellow head-fiers on this thread for instructions and tips for this update. So far I have been impressed by these tubes. For about $150, I consider this to be a significant and worthy update.
> 
> ...


 
  
 Hi TomNC.
  
 So glad to see another pleased convert to the C3g...I suspected a long while ago now this tube could become a prime candidate for our LDs, but I never thought it would reach the star status it truly deserves. It is now also doing incredible wonders for my Feliks-Audio Elise...an amazing tube to be sure...
  
 And as mordy says, upgrading to 6AS7G/6080 powers REALLY shows their magic, lol!!


----------



## i luvmusic 2

mordy said:


> Hi i luvmusic 2,
> 
> I think I have three sizes of 6SN7 tubes as well - don't think that the size makes one tube sound better than another, but it could help in distinguishing which tube to buy if there are several choices from the same manufacturer, and one iteration may sound better.
> 
> ...


 
 Thanks Mordy!
  
   I should try that specially i have more 12SN7 than 6SN7 due to their price difference.
  
 Thanks Again!


----------



## MuZI

Hey guys, quick question. I don't have a tube amp but I'm planning to get one in the future. I'm not sure if this is the right place to ask but my local antique store has a few tubes for $4-$5. Are these worth picking up for anything?


----------



## spiderking31

You can only use certain tubes with a specific amp. So if you buy any tubes, make sure that you can use them in the amp you purchase. And if you buy yourself a bunch of random tunes, chances are that only one pair will work with the amp you decide to purchase. So just be aware of that.


----------



## MIKELAP

muzi said:


> Hey guys, quick question. I don't have a tube amp but I'm planning to get one in the future. I'm not sure if this is the right place to ask but my local antique store has a few tubes for $4-$5. Are these worth picking up for anything?


 
 We can only see one tube number and cant use it in LITTLEDOT amps dont no about the others cant see any numbers go on page 77 several types there or start reading thread from the end for more ideas and tube types there's also page 585 tubes there  for use with adapters.


----------



## WilliamLeonhart

Yep it'd be better if you study the basic on tubes first (it don't take much time and the people at Head-fi are really helpful). But to save time, please tell us the name of your LD model?


----------



## rovopio

Hiya...
  
 So... I'm waiting for LD i+ delivery. While waiting for my LD i+ to arrive, I just started reading LD i+ manual as well. and will read more on this thread on the coming days. For now... I've got 3 things I'd like to ask...
  
 The most important thing 1) How often do I need to clean tube pins with that deoxIT spray?
 Which deoxIT spray exactly do I need to get? There are 4 series I saw on their website...
  
 2) If i buy NOS tubes, in average, how many years / hours will it last? What are the signs of tubes nearing it's end-of-life?
  
 3) What should I pay attention to when buying NOS tubes from eBay? I just checked a 6ak5 I think, and the prices ranges from $11 per pair to $55 per pair. What should I pay attention to, to know which one I should get from the same say, Siemens 6ak5?
  
 4) If a tube series, say 6ak5 has 2 or 3 manufacturers, Siemens, Tung-Sol, and [Insert Name here]. Will all three sounds the same or all three will sound different?


----------



## mimart7

rovopio said:


> Hiya...
> 
> So... I'm waiting for LD i+ delivery. While waiting for my LD i+ to arrive, I just started reading LD i+ manual as well. and will read more on this thread on the coming days. For now... I've got 3 things I'd like to ask...
> 
> ...


----------



## gibosi

rovopio said:


> So... I'm waiting for LD i+ delivery. While waiting for my LD i+ to arrive, I just started reading LD i+ manual as well. and will read more on this thread on the coming days. For now... I've got 3 things I'd like to ask...
> 
> The most important thing 1) How often do I need to clean tube pins with that deoxIT spray?
> Which deoxIT spray exactly do I need to get? There are 4 series I saw on their website...
> ...


 
  
 I substantially agree with Mimart 7 
  
 1) I have never used the deoxit product on Little Dot tubes. That said, in another amp, I have found it to be very helpful with octal power tubes. With Little Dot tubes, I have borrowed a technique from Mordy. I use the back, or dull side, of an Exacto knife blade and scrape the pins to clean them. However, this is usually not necessary, only with tubes that seem unduly noisy. And sometimes it helps... and sometimes it doesn't.
  
 2) Most of these tubes will last thousands of hours. However, if you roll tubes like I do, with hundreds of tubes to choose from, it will take several lifetimes to get that many hours on any one single pair. lol 
  
 3) Matched pairs are a waste of money. Further, as nearly all the standard LD tubes on eBay are NOS, it is the integrity of the seller that is more of a concern than the quality of the tubes.
  
 Which ones to get? The reviews at the beginning of this thread, and the LD 1+ thread might be helpful. (Another hint: use the search function located at the top and bottom of these forums.)
  
 4) And yes, tubes manufactured in different factories by different companies will sound different. And in fact, tubes manufactured in the same factory, but at different times, will often sound different.
  
 Happy rolling!


----------



## mimart7

I have some Tung-Sol 6AK5 coming next week.  They made in 1945.  I also have a pair of Voshkod 6ZH1P-EV.  I'm looking forward to cooking them, and having even more audio goodness.  Thankfully, these purchases are easy enough to hide from the wife.


----------



## rovopio

mimart7 said:


> I have some Tung-Sol 6AK5 coming next week.  They made in 1945.  I also have a pair of Voshkod 6ZH1P-EV.  I'm looking forward to cooking them, and having even more audio goodness.  Thankfully, these purchases are easy enough to hide from the wife.


 
  
 mimart7, (and Gibosi)...
  
 thank you both for your answers. This LD i+ is going to be my first tube so I appreciate your guys answers. I've been narrowing my options to three or four tubes as well. The 6ak5, the 6zh1p-ev, the cv4010, and the 6am6.
  
 Okay one more follow-up question. I don't live in the US so our ebay seller listings will most likely not going to be the same. On mine, I've just searched Tung-Sol 6ak5 just now, the prices varies 24, 28, 33, and 35 USD... one or two listings even list them at 5 and 11 USD.

 1) That's where I'm confused... what should I pay attention to, in the ebay sellers descriptions... that justifies their widely varied price differences?
 The 24, and 28 USD even comes from the same seller. Why the price difference and how do I know which Tung-Sol 6ak5 I should buy?
  
 2) by the way, can I ask you the sellers where you buy both your 6zh1p-ev and you 6ak5 for reference?
  
 regards...
 -Rovopio-


----------



## gibosi

rovopio said:


> Okay one more follow-up question. I don't live in the US so our ebay seller listings will most likely not going to be the same. On mine, I've just searched Tung-Sol 6ak5 just now, the prices varies 24, 28, 33, and 35 USD... one or two listings even list them at 5 and 11 USD.
> 
> 1) That's where I'm confused... what should I pay attention to, in the ebay sellers descriptions... that justifies their widely varied price differences?
> The 24, and 28 USD even comes from the same seller. Why the price difference and how do I know which Tung-Sol 6ak5 I should buy?
> ...


 
  
 When searching for tubes, I use the worldwide setting on the left, so I think I see many of the same sellers.
  
 1) If the tubes are all NOS, I suggest you go for the cheapest. It is sometimes hard to know why one seller lists a pair for $35 and another for $5. But if they seem to be about the same, I always go for the cheapest ones. 
  
 2) It has been several years since I last purchased a 6ak5. In my opinion, the 6HM5 made by EI in Yugoslavia are better and they work in the EF95 setting. Many of us have purchased from this vendor:
  
 http://www.ebay.com/itm/6HM5-EC900-EI-Yugoslavia-NOS-matched-pair-Little-Dot-Amp-/251765500700?


----------



## rovopio

gibosi said:


> When searching for tubes, I use the worldwide setting on the left, so I think I see many of the same sellers.
> 
> 1) If the tubes are all NOS, I suggest you go for the cheapest. It is sometimes hard to know why one seller lists a pair for $35 and another for $5. But if they seem to be about the same, I always go for the cheapest ones.
> 
> ...


 
  
 Do you own Voshkod 6zh1p-ev,  gibosi?
 Do you still remember the ebay sellers / links you bought it from?
  
  
 ps: Even with Worldwide option, not all sellers listed every country in the world. If they don't list the South Asia contry country I live in, it still won't appear on my eBay listing. I originally have a Japan address so that's less of a problem for me personally, as long as I set my eBay primary shipping to address to my old Japan's address.
 But that is neither here nor there.
  
 I think from my short reading, I'm mostly interested on Voshkod 6zh and the 6ak5, so by extension, your recommended 6hm5 as well... I'm going to continue reading more since the LD i+ won't reach me until the end of the month... customs and everything.


----------



## SonicTrance

rovopio said:


> Do you own Voshkod 6zh1p-ev,  gibosi?
> Do you still remember the ebay sellers / links you bought it from?
> 
> 
> ...


 
 I can highly recommend the 6HM5's over the other two as well. They are a far superior tube in the little dot, and they're cheap as well. You wont regret it!


----------



## rovopio

sonictrance said:


> I can highly recommend the 6HM5's over the other two as well. They are a far superior tube in the little dot, and they're cheap as well. You wont regret it!


 
  
 By the other two, you mean 6zh1p-ev and the 6ak5 right?
   
 



gibosi said:


> When searching for tubes, I use the worldwide setting on the left, so I think I see many of the same sellers.
> 
> 1) If the tubes are all NOS, I suggest you go for the cheapest. It is sometimes hard to know why one seller lists a pair for $35 and another for $5. But if they seem to be about the same, I always go for the cheapest ones.
> 
> ...


 
  
  
 Thanks for all the good advice gibosi!
  
 Sure will going to save me some money from my shoestring wallet from reading your comments. Especially the matched pairs comments...
 I don't have to specifically look for matched pairs now if non-matched pairs sounds as good. 
  
 the 6hm5 is easy on my budget as well, so thank you for the recommendations guys.
  
 By the way Gibosi and -MisterX-, can I ask you both a question?

  


> Between the three... 6hm5 - 6zh1p-ev - 6ak5 -, let's and throw in the cv4010 also.
> 
> In your experience, disregarding any other factors, which one of the four fits the best if what I care about is primarily "lower and middle registers female vocals"?


----------



## SonicTrance

rovopio said:


> By the other two, you mean 6zh1p-ev and the 6ak5 right?
> ...
> By the way Gibosi and -MisterX-, can I ask you both a question?


 
 Correct.
 ...
 It's been a while since I listened to these type of tubes and I no longer have the amp for them. But I remember very clearly that the 6HM5's took the amp to another level. There's lots of posts in this thread about the 6HM5 tube, if you search for it you will find it


----------



## mimart7

rovopio said:


> Do you own Voshkod 6zh1p-ev,  gibosi?
> Do you still remember the ebay sellers / links you bought it from?
> 
> 
> ...


 
 What ever tubes you decide on, remember to let them "cook."  David (the maker of your amp) recommends that when your are "cooking" your tubes, that you have your headphones plugged in.  Tube rolling can be addictive, lol.


----------



## gibosi

rovopio said:


> Do you own Voshkod 6zh1p-ev,  gibosi?
> Do you still remember the ebay sellers / links you bought it from?


 
  
 I purchased mine from this vendor:
  
 http://www.ebay.com/itm/1-pc-or-more-6J1P-EV-EF95-6F32-6AK7-gold-plated-and-platinized-grid-NOS-NIB-/131455349947?
  
 Cheap! 
  
 Also, 6J1P = 6ZH1P.
  


rovopio said:


> .....I originally have a Japan address so that's less of a problem for me personally, as long as I set my eBay primary shipping to address to my old Japan's address.
> But that is neither here nor there.


 
  
 日本人かな。


----------



## rovopio

mimart7 said:


> What ever tubes you decide on, remember to let them "cook."  David (the maker of your amp) recommends that when your are "cooking" your tubes, that you have your headphones plugged in.  Tube rolling can be addictive, lol.


 
  
 thanks for the advice. In a few years, probably it will be addictive. As for know, I will narrow down my tube upgrade to just 1 tube, and will further read on which one will be the best one for my needs. Instant noodles diet and everything..
  


sonictrance said:


> Correct.
> ...
> It's been a while since I listened to these type of tubes and I no longer have the amp for them. But I remember very clearly that the 6HM5's took the amp to another level. There's lots of posts in this thread about the 6HM5 tube, if you search for it you will find it


 
  
 Thank you! I will search for the relevant posts.
  
 Quote:


gibosi said:


> I purchased mine from this vendor:
> 
> http://www.ebay.com/itm/1-pc-or-more-6J1P-EV-EF95-6F32-6AK7-gold-plated-and-platinized-grid-NOS-NIB-/131455349947?
> 
> ...


 
  
 いいえ、ただ。。日本に住んだことがあるだけ。。。
  
 By the way, Gibosi...Generally speaking, what's your primary recommendation of tubes if the primary point of what I'm looking for is lower-to-middle register female vocals (~midrange area)?
  
 If I'm on a tight budget and is going to just choose one upgrade tubes...
 Will it be the 6hm5 or the 6zh1p-ev? Or is there another tube I should consider? A tube that complements a cheap grado headphone for artists like バイジ or ソッテボッセ　or Couleur Cafe, or ☆marleys☆, or Thelma Aoyama...
  
 ps: Thanks again for all the cost-saving measures. I think I'm going to only get 1 pair of upgrade tubes at first before saving up to maybe buy more.
 Well maybe 1 pair of tube and that $1 tube, which is just awesome. perfect for my shoestring budget 
  
 pps: I'm reading the backlogs of this thread for the 6hm5, and after I'm done with that, I will read the 6zh1p-ev


----------



## gibosi

rovopio said:


> By the way, Gibosi...Generally speaking, what's your primary recommendation of tubes if the primary point of what I'm looking for is lower-to-middle register female vocals (~midrange area)?
> 
> If I'm on a tight budget and is going to just choose one upgrade tubes...
> Will it be the 6hm5 or the 6zh1p-ev? Or is there another tube I should consider? A tube that complements a cheap grado headphone for artists like バイジ or ソッテボッセ　or Couleur Cafe, or ☆marleys☆, or Thelma Aoyama...
> ...


 
  
 To my ears, the 6hm5 is better than the 6zh1p-ev in every respect. But it is important to remember that everyone's ears and gear are different. Not everyone agrees with me. lol 
  
 As Mordy, one of our colleagues, reminds us, tubes are like ice cream. Everyone has a different favorite flavor. And eating lots of ice cream is the only way to learn what your favorite flavor is. So in the end, eventually, you are going to have to purchase several different tubes to learn what which ones are your favorites. Given your shoestring budget, my advice is to start with either of these, the 6HM5 or the 6ZH1P, as they are both fairly inexpensive. And then as your wallet recovers, try the other, and then another, and then another....  
  
 As mimart7 warns, tube rolling can get addictive. I have about 900 tubes, 5 more arrived today, and there is no Tube-Aholics Anonymous group in my town. lol.


----------



## rovopio

^
  
 I've been reading the backlog of this thread and the LD i+ specific thread. I've narrow my choices down to the 2 options you guys suggested as well. A small question on the op-amp, during the past 5 hours of reading... I've read that Muses02 has fakes. When you bought your Muses02 op-amp... How do you and others know that you aren't getting a fake?
  
 I'm sure yours are the genuine one but um... locally Muses02 goes for $85-$90 due to this "Fake Scare" that I think is partially manufactured by the individual sellers importing varieties of op-amps from China...
 So, how do you know that yours are genuine when you bought it?

 Secondly, is it better to get upgraded op-amps (say, the Muses02), and get a tube 3 months later, or get a tube, and an op-amps 3 months later?
 I mean... which one in your opinion is more noticeable in Sound Upgrades?
  
 ps: i already have a decent, budget solid state amps (a Magni) so... neutrality and clarity is not my number one goal for this LD i+.
 More the "synergy" so-to-speak with a Grado headphone. And because I hang out too much on the Grado thread. And eventually were led here by the Grados people.


----------



## gibosi

rovopio said:


> I've been reading the backlog of this thread and the LD i+ specific thread. I've narrow my choices down to the 2 options you guys suggested as well. A small question on the op-amp, during the past 5 hours of reading... I've read that Muses02 has fakes. When you bought your Muses02 op-amp... How do you and others know that you aren't getting a fake?
> 
> I'm sure yours are the genuine one but um... locally Muses02 goes for $85-$90 due to this "Fake Scare" that I think is partially manufactured by the individual sellers importing varieties of op-amps from China...
> So, how do you know that yours are genuine when you bought it?
> ...


 
  
 I often read that there are fake Muses02  but I have never read an account by anyone who actually received one. If fake muses02 exist, they appear to be exceedingly rare, and in my opinion, and again, this is only my opinion, this is not as big of a problem as some would have us believe....
  
 I and a number of others have purchased from the vendor below. I purchased both the Muses01 and Muses02.
  
 http://www.ebay.com/itm/400418607953?
  
 This vendor specializes in IC devices and has a feedback score of 90425 with 99.4 positive feedback, so I feel the risk of getting a fake is very low.
  
 In my opinion, the op amp is more important. Once people find an opamp they like, most leave it in, and in effect, it becomes a fixed part of the amp. That settled, you can then focus on which tubes have the best synergy with the rest of your gear.


----------



## rovopio

gibosi said:


> I often read that there are fake Muses02  but I have never read an account by anyone who actually received one. If fake muses02 exist, they appear to be exceedingly rare, and in my opinion, and again, this is only my opinion, this is not as big of a problem as some would have us believe....
> 
> I and a number of others have purchased from the vendor below. I purchased both the Muses01 and Muses02.
> 
> ...


 
  
 Is the stock tube as bad as people report? Like really suck?
 My budget is $35 so I can swallow $40 for the op-amps but then I won't be able to get a tube upgrade.
  
 By the way, I've read your reports on Muses02 when that posts happened to have the same content where you also write 6hm5 as a keyword (searched by relevance). I haven't been able to found your proper impression of muses02 vs stock op-amps though because I've been going backwards based on 6hm5 and 6zh1p-ev relevance search.
 Have you made a muses02 -- stock op-amps impression in the past? Is it on this thread?
  
 What kind of improvements in SQ did you noticed when you upgrade from the stock op-amps?
  
 And lastly, is it essential to also buy this for a first time op-amp changer?
 http://www.ebay.com/itm/6pcs-New-8-Pin-Gold-Plated-Socket-For-OP-AMP-DIP8-/261179539940?pt=LH_DefaultDomain_0&hash=item3ccf8381e4&rmvSB=true


----------



## gibosi

rovopio said:


> Is the stock tube as bad as people report? Like really suck?
> My budget is $35 so I can swallow $40 for the op-amps but then I won't be able to get a tube upgrade.
> 
> By the way, I've read your reports on Muses02 when that posts happened to have the same content where you also write 6hm5 as a keyword (searched by relevance). I haven't been able to found your proper impression of muses02 vs stock op-amps though because I've been going backwards based on 6hm5 and 6zh1p-ev relevance search.
> ...


 
  
 Most believe that the stock tubes suck, yes. But again, there are some who actually like them. As always, different ears and gear....
  
 I have tried the stock MC33078, an OPA2107, an LME 49990 and the MUSES 01, and I like the MUSES 02 the best.
  
 I found the stock op amp to be very congested. The LME 49990 and MUSES 01 were much more transparent, but I found the bass lacking and too cool for my ears.The OPA2107 was a huge improvement, more transparent, better bass and with a bit of warmth. But after a while, I felt that the highs were somewhat rolled off and the mids a bit shouty. To my ears the MUSES02 is an improved OPA2107, with great bass, a nice bit of warmth, better highs and a smooth, silky midrange. But again, this is with my ears and gear.
  
 And no, it is not necessary to purchase one those sockets. What this does is act like a riser so that it is much easier to get your fingers on the opamp in order to remove it. Without it, you may have to use a small screwdriver or something similar to pry the opamp out. But of course, once you find an opamp you like, perhaps you will never to need to remove it again....
  
 It strikes me that given your budget, the OPA2107 and a few new tubes might give you the most bang for the buck. And later, after you have been able to spend some time with your LD, and after your wallet recovers, you will have a better idea what, if anything, you might to swap out next.
  
 Cheers


----------



## rovopio

gibosi said:


> Most believe that the stock tubes suck, yes. But again, there are some who actually like them. As always, different ears and gear....
> 
> I have tried the stock MC33078, an OPA2107, an LME 49990 and the MUSES 01, and I like the MUSES 02 the best.
> 
> ...


 
  
 I think I'm partially set on ordering the 6hm5. Let things sink in for a night before ordering... I have a question, the link you gave me <tubes-rs> sells a matched pair. So I can only buy either in 2 or 4. I've read one or two (rare) posts about tube imbalance. Since you and some other members here rolled a lot of tubes.. how often does tube imbalance fresh-off-delivery happens?
  
 Whenever somebody buys a tube.. is it considered good practice to buy extras to avoid imbalance or tube imbalance is so rare that getting 2 will likely be okay?


----------



## gibosi

rovopio said:


> I think I'm partially set on ordering the 6hm5. Let things sink in for a night before ordering... I have a question, the link you gave me <tubes-rs> sells a matched pair. So I can only buy either in 2 or 4. I've read one or two (rare) posts about tube imbalance. Since you and some other members here rolled a lot of tubes.. how often does tube imbalance fresh-off-delivery happens?
> 
> Whenever somebody buys a tube.. is it considered good practice to buy extras to avoid imbalance or tube imbalance is so rare that getting 2 will likely be okay?


 
  
 Fortunately, most LD tubes are NOS, and therefore, tube imbalance is not a significant problem. If the LD used the popular double triodes, such as 6SN7, 12AX7 and 6DJ8, NOS tubes are the exception and quite rare. And therefore, many if not most of these double triodes available on eBay are used. When buying used tubes, tube imbalance is a real possibility, and many vendors provide measurements to reassure buyers that the tubes are balanced and not on their last legs, or dead. But again, with the LD, this is not something we need to worry about.
  
 If tubes are really cheap, I like to get extras. But if they are rather expensive, I wait to see if I like them. No reason to have extras of tubes I don't like. lol.  And if I do like them, then I try to get a few backup pairs.


----------



## rovopio

gibosi said:


> Fortunately, most LD tubes are NOS, and therefore, tube imbalance is not a significant problem. If the LD used the popular double triodes, such as 6SN7, 12AX7 and 6DJ8, NOS tubes are the exception and quite rare. And therefore, many if not most of these double triodes available on eBay are used. When buying used tubes, tube imbalance is a real possibility, and many vendors provide measurements to reassure buyers that the tubes are balanced and not on their last legs, or dead. But again, with the LD, this is not something we need to worry about.
> 
> If tubes are really cheap, I like to get extras. But if they are rather expensive, I wait to see if I like them. No reason to have extras of tubes I don't like. lol.  And if I do like them, then I try to get a few backup pairs.


 
  
 I just did a quick search on ebay for opa2107. What kind of description should I pay attention to when choosing the seller? The price discrepancies are even wider than tubes model. Some sellers sell the opa2107 as low as $1 and a couple cents, some other sellers sells them as high as $12 and $18...
  
 Are the $1 and the $18 the same opa2107, generally speaking?


----------



## gibosi

rovopio said:


> I just did a quick search on ebay for opa2107. What kind of description should I pay attention to when choosing the seller? The price discrepancies are even wider than tubes model. Some sellers sell the opa2107 as low as $1 and a couple cents, some other sellers sells them as high as $12 and $18...
> 
> Are the $1 and the $18 the same opa2107, generally speaking?


 
  
 I can't imagine anyone making fakes as these are already cheap, so there really shouldn't be any difference. This listing is from the same vendor, Janeh2100, I purchased my MUSES from. Not as cheap as $1, but still quite cheap.
  
 http://www.ebay.com/itm/1PC-OPA2107AP-OPA2107-Dual-Low-Noise-OPAMP-DIP8-NEW-/330590537762?


----------



## rovopio

gibosi said:


> I can't imagine anyone making fakes as these are already cheap, so there really shouldn't be any difference. This listing is from the same vendor, Janeh2100, I purchased my MUSES from. Not as cheap as $1, but still quite cheap.
> 
> http://www.ebay.com/itm/1PC-OPA2107AP-OPA2107-Dual-Low-Noise-OPAMP-DIP8-NEW-/330590537762?


 
  
 ahhh, i'm confused. I sort of disliked shouty upper midrange.
  
 Well, natural preference-wise, I like them, but my inner ear has treble sensitivity (vestibular neurinitis) so I can't handle shouty midrange. Hence, my initial decision to experiment with getting a LD i+ to complement a shouty Grado that is currently plugged to a Magni (which sounds quite neutral).
  
 $3.5 is like, so big difference with $40 >_<. If only Muses02 is cheaper by half...


----------



## gibosi

I have no experience with Grados, but if they are as you say, then the 2107 might not be a good fit. Perhaps you should spend your budget on tubes. The MUSES can wait.
  
 And not only that, perhaps it would be best to wait until have listened to the stock LD  a while before buying any tubes or opamps.


----------



## rovopio

gibosi said:


> I have no experience with Grados, but if they are as you say, then the 2107 might not be a good fit. Perhaps you should spend your budget on tubes. The MUSES can wait.
> 
> And not only that, perhaps it would be best to wait until have listened to the stock LD  a while before buying any tubes or opamps.


 
  
 The standard shipping is pretty long isn't it? Isn't a standard Airmail like almost 3 weeks or something?
 My estimation is that the LD i+ will reach me at the end of this month. I e-mailed David regarding tracking number but he hasn't reply since the 18th. Once I got confirmation of delivery, I will most likely get the tubes so that both amps and tubes will reach me at the same time...
  
 3 weeks on top of whenever the ld i+ will arrive is pretty long wait 
  
 From the half a day readings that I've done I think I narrow done the purchase into three, first get the 6hm5. If the 6hm5 is too bright then I'll get the Mullard cv4010 next, if on the other hand i want more brightness, then I'll get the voskhod 6zh1p-ev next.
  
 Locally I can get the Mullard at $23 each. I hope I can get less on eBay when the time comes, if I have to try them out.


----------



## gibosi

rovopio said:


> The standard shipping is pretty long isn't it? Isn't a standard Airmail like almost 3 weeks or something?
> My estimation is that the LD i+ will reach me at the end of this month. I e-mailed David regarding tracking number but he hasn't reply since the 18th. Once I got confirmation of delivery, I will most likely get the tubes so that both amps and tubes will reach me at the same time...


 
  
 Here in the US, I get most shipments with two weeks. For example, a pair of tubes were shipped from Bulgaria on the 11th, and arrived today, the 20th. But I understand that it is different in every country....


----------



## mimart7

I got my LD MK III in a few days after ordering it, but that was to the US.  Tubes from Russia take about a week, but from Ukraine take longer (understandably so.)  Lucking tubes are low vale items and don't have to linger here in US Customs.  But, ymmv.


----------



## MIKELAP

gibosi said:


> rovopio said:
> 
> 
> > The standard shipping is pretty long isn't it? Isn't a standard Airmail like almost 3 weeks or something?
> ...


 

 10 workdays to Montreal .


----------



## gibosi

For those who might be rolling double triodes using an external 9-pin socket, another tube to try. 
  
 ECC804, which can also be found labeled as 6/30L2, 6GA8 and B729. As far as I can tell, it was made only by Brimar/Mazda. Most of the tubes I have seen carry the Mazda label. The ECC804 has the same pinout as the 6CG7 and 6DJ8. Further, the heaters pull only 0.3 amps, so no external heater power supply is necessary.
  
 Interestingly, the first time I became aware of this tube, it was labeled as a 6CG7. In fact, Upscale Audio will sell you one for $65! Fortunately, Oskari's sharp eye found a Brimar tube code on one of these "6CG7"s which reveals that it is actually a ECC804. Perhaps back in the day someone had this great idea of labeling these as 6CG7 and selling them in the US? lol. As they are quite cheap on eBay, decided to give one a try.
  
 I haven't been able to spend much time with this tube, but first impressions, it has the characteristic Brimar house sound, very smooth, liquid midrange, clean highs and a big bass. A very nice tube.


----------



## rovopio

gibosi said:


> Here in the US, I get most shipments with two weeks. For example, a pair of tubes were shipped from Bulgaria on the 11th, and arrived today, the 20th. But I understand that it is different in every country....


 
  
  


mimart7 said:


> I got my LD MK III in a few days after ordering it, but that was to the US.  Tubes from Russia take about a week, but from Ukraine take longer (understandably so.)  Lucking tubes are low vale items and don't have to linger here in US Customs.  But, ymmv.


 
  
  


mikelap said:


> 10 workdays to Montreal .


 
  
 Customs on the country doesn't use x-ray, instead opening box one-by-one so, it takes considerably longer time to send personal items to the country haha.
  
 I think I'm going for the 6hm5 for now. It seems like the best bet. Thank you for all the help guys!
 Also -misterX- which i didn't quote on this post


----------



## i luvmusic 2

mikelap said:


> >
> 
> 
> 
> ...


 
 A month to GTA from TAIWAN


----------



## rovopio

Guys... can I ask what are some good tips practices for using the amps?
  
 Other than the 8 hours - 1 hour  on-off instruction on the LD i+ manual. I mean, the manual said "only plug/unplug when LD is off", while what I read during my thread backlog search was, -I'm paraphrasing here-, _if tubes failed, it will usually fail on the on or_ _off time, plug headphones after the amp is on, and unplug before turning off._
  
 So... which practice should i follow?
 Also, I've heard that tubes amps in general needs some "warming-up" period. Is that true and how many minutes / hours is a tube warming-up period in general before I start listening to them?
 Any other practice I should follow?


----------



## SonicTrance

rovopio said:


> Guys... can I ask what are some good tips practices for using the amps?
> 
> Other than the 8 hours - 1 hour  on-off instruction on the LD i+ manual. I mean, the manual said "only plug/unplug when LD is off", while what I read during my thread backlog search was, -I'm paraphrasing here-, _if tubes failed, it will usually fail on the on or_ _off time, plug headphones after the amp is on, and unplug before turning off._
> 
> ...




I always power on the amp, let it warm up for a few minutes, then I plug in my headphones with the volume turned all the way down. And I always unplug the headphones before turning off the amp, also with the volume turned all the way down.


----------



## rovopio

mordy said:


>


 
  
 Will this happen every single time mordy? From the time you bought them up until now?
 I think that is unique and neat... Sort of looking forward to it.
  
 Do you mind if i ask... is it safe?


----------



## MIKELAP

rovopio said:


> mordy said:
> 
> 
> >
> ...


 
 Dont know exactly what you mean but is there a bright flash when you turn on amp and then it dimms again . I have a few tubes that do that its normal.its there way of warming up if i remember correctly


----------



## MIKELAP

sonictrance said:


> rovopio said:
> 
> 
> > Guys... can I ask what are some good tips practices for using the amps?
> ...


 

 In my  Woo Audio amps it is recommended to have a headphone plugged in on startup so i use a cheap pair, so if a tube goes and takes out my headphone its no big deal


----------



## rovopio

mikelap said:


> In my  Woo Audio amps it is recommended to have a headphone plugged in on startup so i use a cheap pair, so if a tube goes and takes out my headphone its no big deal


 
  
 As to the photo above.. yeah I meant the Flare / fireworks. It looks pretty nice.
  
 Well i have to get a $10 headphone now. I don't have any. What is the reason for Woo and Little Dot recommending headphones to be plugged in during startup? Is there anything to do with the vaccuum tubes or something?


----------



## MIKELAP

rovopio said:


> mikelap said:
> 
> 
> > In my  Woo Audio amps it is recommended to have a headphone plugged in on startup so i use a cheap pair, so if a tube goes and takes out my headphone its no big deal
> ...


 

 Here's the e-mail he sent me


----------



## Shaffer

As a FYI for anyone interested in getting into tube rolling, I just listed my LDIII for sale with many upgraded tubes:

http://www.head-fi.org/t/772250/fs-little-dot-mkiii-with-many-upgraded-tubes-some-of-the-best-available#post_11707625


----------



## gibosi

rovopio said:


> Well i have to get a $10 headphone now. I don't have any. What is the reason for Woo and Little Dot recommending headphones to be plugged in during startup? Is there anything to do with the vaccuum tubes or something?


 
  
 The Woo has an output transformer which can be damaged if the amp is run without a load. And it appears that Woo has incorporated a special circuit to protect the headphones when the amp is turned on and while it warms up. As for the LD, I have no idea why the company recommends that cans be plugged in before turning the amp on. Neither an OTL amp (LD II, III and IV) nor a hybrid (LD 1+) can be damaged if turned on without the cans plugged in. Following the advice of MisterX guarantees that your ears and/or headphones will not be damaged if the amp fails catastrophically. So to my way of thinking, protecting ears and expensive cans is the best practice, especially since it doesn't hurt the amp. And this is my standard operating procedure as well.


----------



## mordy

Hi rovopio,
  
 The Ei 6HM5 tubes have a flash heating feature (no doubt for military purposes) to heat up the filament quickly and get the tube up to operating temperature quickly. The start up flash is perfectly normal for this tube.
  
 However, when it happened to me the first time I was using the tube I got scared and thought something went wrong with my amp, but this is nothing to worry about  with this specific tube. Somewhere on this blog I managed to post a picture of it as well.
  
 As is generally agreed, the 6HM5 tubes are among the best plug and play driver tubes for the Little Dot MKIII. To get better performance, you need to upgrade to dual triodes with the required external voltage supply, voltage regulator and special adapters.
  
 Another simpler step is to stay with the 6HM5 tubes and upgrade to plug and play power tubes (will require socket adapters) such as 6SN7.
  
 Good luck!


----------



## Shaffer

mordy said:


> [...]
> 
> Another simpler step is to stay with the 6HM5 tubes and upgrade to plug and play power tubes (will require socket adapters) such as 6SN7.
> 
> Good luck!


 

That's the setup I used a lot. The Yugos compliment a lot of 6SN7s.


----------



## mimart7

These just arrived, and I have 2 cooking, now.  WW 2 vintage.


----------



## mordy

Hi m7,
  
 I have these tubes in a different box - not sure if u r going to like them. IMH experience the 6AK5 Tung Sol tubes from the 50s and 60s sounded better. Amazing that these tubes that are 70 years old still work well......


----------



## rovopio

gibosi said:


>


 
  
 I just paid for the OPA2107AP from Janeh2100. She replied very quickly to my questions. Mainly to ask about Express Shipping.
 ps: it's extra $4. Which is completely fine as I don't have to wait 3 weeks for it...
  
 Got the 6hm5 as well from Tachonz.


----------



## mimart7

mordy said:


> Hi m7,
> 
> I have these tubes in a different box - not sure if u r going to like them. IMH experience the 6AK5 Tung Sol tubes from the 50s and 60s sounded better. Amazing that these tubes that are 70 years old still work well......


 
 They are still cooking, but i will look into Tung-Sols with a later manufacturing date.


----------



## rovopio

So... my LD i+ arrived. Inside the Interconnect Cable Package I found the cable, a 6.3mm adapter, and 2 rectangular thing.
 1) What does that called and what is the purpose of that rectangular thing?
  


>


 
  
 2) By the way, May I ask what is the Factory Default Setting of the LD i+? Is it already at Low Gain with 6J1 tube setting?
  
 3) Also one more question, I don't get a paper invoice from David. Is that normal?
 The manuals for LD i+ stated that warranty claims need to be accompanied by proof of purchase. I only have PP screenshot as of now.
  
 I did ask him for Digital Invoice scan a week ago while waiting for shipping and while he answered my other questions in that same e-mail, he didn't reply to my request on asking for Digital Invoice. I figured at the time, maybe he didn't do Digital Invoice request, and I can always scan the paper by myself when the LD i+ arrived but... apparently I didn't get a paper invoice either.
  
 Is this normal or he just happened to forgot?
  
 Edited :: 4) David shipped me the US Power Cord also. The country I live in uses the UK-type plug.
 My question basically is... Can I use the supplied US Power Cord and plug it to Passive Traveller's All-in-One converter? Will that be safe?
  
 Or do I have to get a new 220V UK-plug Power Cord instead?
   
If there is any people here living in the Europe I'd appreciate the answer to this specific question. Cheers...


----------



## mimart7

rovopio said:


> So... my LD i+ arrived. Inside the Interconnect Cable Package I found the cable, a 6.3mm adapter, and 2 rectangular thing.
> 1) What does that called and what is the purpose of that rectangular thing?
> 
> 
> ...


 
 You can use a converter, or you buy a new cord, from a local shop.  They should be inexpensive.


----------



## rovopio

mimart7 said:


> You can use a converter, or you buy a new cord, from a local shop.  They should be inexpensive.


 
  
 Thanks mimart7. I bought a OPA2107 and 6hm5 as well, and are now waiting for them to arrived. I think my Stock Tube noticeably hisses. I read LD i+ manual and it said to clean them I have to use the deoxIT. Checked out the local price, they are selling them at $55. Wow, that's more expensive than a MUSES02 so I'll pass... lol 
  
 By the way, did you get a paper invoice when you bought your Little Dot amp? Or same like me, you don't get any invoice and only got that yellow chinese-written small paper (that seems like a warranty card) also?


----------



## mimart7

I believe I got the same card.  As far as the hissing goes, there really is zero need for that cleaning solution.  Try reseating the tubes, and they need to cook for at least 20 hours.  Your headphones need to be plugged in, and music does not have to be playing.  You can let them cook for up 8 hours at a time, with a minimum of 30 minutes of the amp being powered off.  Do you hear the hissing when you have the amp turned, with no music playing?


----------



## rovopio

mimart7 said:


> I believe I got the same card.  As far as the hissing goes, there really is zero need for that cleaning solution.  Try reseating the tubes, and they need to cook for at least 20 hours.  Your headphones need to be plugged in, and music does not have to be playing.  You can let them cook for up 8 hours at a time, with a minimum of 30 minutes of the amp being powered off.  Do you hear the hissing when you have the amp turned, with no music playing?


 
  
 Yes, only when the music is not playing.
 When the music is playing, it's so loud even at volume pot 10 (7 o'clock), I can't hear the hissing. It's quite loud for my Grado headphone.


----------



## mimart7

rovopio said:


> Yes, only when the music is not playing.
> When the music is playing, it's so loud even at volume pot 10 (7 o'clock), I can't hear the hissing. It's quite loud for my Grado headphone.


 
 Power down the amp, wait 10 minutes, swap the sockets the the tubes are in.


----------



## rovopio

mimart7 said:


> Power down the amp, wait 10 minutes, swap the sockets the the tubes are in.


 
  
 By swapping the sockets, do you mean I should move Tube A from the left side to the right side and vice-versa?
 Or do you mean I should open the amp's bottom chassis and swap the white sockets?
  
 By the way, is there a specific way to handle the tubes? Like I shouldn't touch them by hand or something?
 So far I use tissue to take them on and off to minimize fingerpirnts. But if there is a proper way of handling tubes... I will do it.


----------



## mimart7

Yes, Swap Socket A, with Socket B.  Just grab the tubes by the sides, and you can just wiggle them out out.  Don't be too rough.


----------



## rovopio

mimart7 said:


> Yes, Swap Socket A, with Socket B.  Just grab the tubes by the sides, and you can just wiggle them out out.  Don't be too rough.


 
  
 I just opened the Bottom Chassis just now. How do I swap Socket A with Socket B?
 It looks like it is soldered to the circuit board...


----------



## mimart7

rovopio said:


> I just opened the Bottom Chassis just now. How do I swap Socket A with Socket B?
> It looks like it is soldered to the circuit board...


 
  
 Don't swap the sockets, just the tubes.


----------



## MIKELAP

rovopio said:


> mimart7 said:
> 
> 
> > Power down the amp, wait 10 minutes, swap the sockets the the tubes are in.
> ...


 

 He means swap the tube what i use to swap tubes is a rubber finger that i fit over the tube doesnt slip when removing .about those rectangular pieces you talked about those are called jumpers and should be in your amp depending on the family of tube you are using check the thread for pictures or your manual because for example for EF 95 family of tuibes the jumpers should be on certain pins and for EF92 tubes on other pins this is imporant just research JUMPERS atop the page where   its writen SEARCH THIS THREAD .  pictures below are the longer version of jumpers that i use in the LDMK3  because i dont have to remove cover but the short jumpers in mk3 are a pain to remove .About cleaning pins personnally i refuse to pay $20.00 and more for deoxit i buy another brand   thats around $7.00 a can but first i use sandpaper to clean pins then the cleaner


----------



## MIKELAP

rovopio said:


> mimart7 said:
> 
> 
> > Yes, Swap Socket A, with Socket B.  Just grab the tubes by the sides, and you can just wiggle them out out.  Don't be too rough.
> ...


 

 In my picture the arrows show where the jumpers go ,at bottom theres no jumper on but at the top looks like there is one not shure its the jumpers location below its written EF92 on my MK3 is not like that check to make shure you have the right jumpers on in the right places also you can see where its written EF92 OR EF95 cant see very well  though


----------



## rovopio

mikelap said:


> He means swap the tube what i use to swap tubes is a rubber finger that i fit over the tube doesnt slip when removing .about those rectangular pieces you talked about those are called jumpers and should be in your amp depending on the family of tube you are using check the thread for pictures or your manual because for example for EF 95 family of tuibes the jumpers should be on certain pins and for EF92 tubes on other pins this is imporant just research JUMPERS atop the page where   its writen SEARCH THIS THREAD


 
  
 I read the manuals yeah, I didn't know that the small rectangular thing was the jumper though, before I opened the bottom chassis. Those jumpers of yours looks nice, maybe I'll find one off e-bay. When i opened the bottom chassis, my amp was open circuit on the gain setting, so i put 2 jumpers to close them to make the gain back to 3.5 Low Gain. And uh, I re-check the tube jumpers setting, moved it to make them 6J1.
  
 On that note, one of the jumper of mine gone bad though, the silver metal and the black plastic got separated from each other when I tried to remove them from the 408A side to the 6J1 side. But it's one of 6 and with 6J1 there are 2 unused jumpers so I'm covered. But that extended jumpers on your picture looks pretty convenient too.
  
 On the DeoxIT, there is only 1 store in the whole nation that is selling them and I'm not sure about shelling $55. So that's my update. Have also swap the tubes between A and B. I haven't try them again though because I only have one PC power cable. So I'll try them again when my PC are off.


----------



## mimart7

rovopio said:


> I read the manuals yeah, I didn't know that the small rectangular thing was the jumper though, before I opened the bottom chassis. Those jumpers of yours looks nice, maybe I'll find one off e-bay. When i opened the bottom chassis, my amp was open circuit on the gain setting, so i put 2 jumpers to close them to make the gain back to 3.5 Low Gain. And uh, I re-check the tube jumpers setting, moved it to make them 6J1.
> 
> On that note, one of the jumper of mine gone bad though, the silver metal and the black plastic got separated from each other when I tried to remove them from the 408A side to the 6J1 side. But it's one of 6 and with 6J1 there are 2 unused jumpers so I'm covered. But that extended jumpers on your picture looks pretty convenient too.
> 
> On the DeoxIT, there is only 1 store in the whole nation that is selling them and I'm not sure about shelling $55. So that's my update. Have also swap the tubes between A and B. I haven't try them again though because I only have one PC power cable. So I'll try them again when my PC are off.


 

 Unless the tubes are seriously corroded, (the pins are green) you have zero need for DeoxIT; save your money.  My tubes from 1945 have a little corrosion, and I was able to scrape that off, and clean up with alcohol.  Jumpers are jumpers, you can get them at any computer shop for very little money.


----------



## mordy

Hi rovopio,
  
 There are people that have studied the best way of removing oxidation on tube pins, and the simplest solution works the best. Just take a pocket knife or pen knife and use the little blade to gently scrape clean the pins. Or sandpaper, or even a little cup with sand in it - twirl the the bottom of the tube with the pins in the sand.


----------



## mimart7

mikelap said:


> He means swap the tube what i use to swap tubes is a rubber finger that i fit over the tube doesnt slip when removing .about those rectangular pieces you talked about those are called jumpers and should be in your amp depending on the family of tube you are using check the thread for pictures or your manual because for example for EF 95 family of tuibes the jumpers should be on certain pins and for EF92 tubes on other pins this is imporant just research JUMPERS atop the page where   its writen SEARCH THIS THREAD .  pictures below are the longer version of jumpers that i use in the LDMK3  because i dont have to remove cover but the short jumpers in mk3 are a pain to remove .About cleaning pins personnally i refuse to pay $20.00 and more for deoxit i buy another brand   thats around $7.00 a can but first i use sandpaper to clean pins then the cleaner


 
  
 Here is an ebay listing for those jumpers, http://www.ebay.com/itm/100pcs-2-54MM-STANDARD-COMPUTER-JUMPER-CAPS-WITH-HANDLE-/370412394037?pt=LH_DefaultDomain_0&hash=item563e4c9635


----------



## MIKELAP

For MK3 owners and others those long jumpers are just woderful no more stress when changing positions thru the peepholes .Or mordy made an extension for the jumpers you can see this on page 220 post#3297


----------



## rovopio

^
  
 I hope i can find one locally. On top of not needing 100 pcs of jumpers, regardless of price, anything that enters the country over 10 in quantity will be tagged as "Indication for Retail or Distribution", and it's just a mess to take care of, for individual entity.
  
 I really don't know where I can find htem though, tried Ace Hardware and the PC District in my city, and they don't have both Power Cable nor Jumpers. They do have varieties of Cables though. Maybe I should check out the DIY-Electronic-Parts section of the city to find both items.


----------



## MIKELAP

rovopio said:


> ^
> 
> I hope i can find one locally. On top of not needing 100 pcs of jumpers, regardless of price, anything that enters the country over 10 in quantity will be tagged as "Indication for Retail or Distribution", and it's just a mess to take care of, for individual entity.
> 
> I really don't know where I can find htem though, tried Ace Hardware and the PC District in my city, and they don't have both Power Cable nor Jumpers. They do have varieties of Cables though. Maybe I should check out the DIY-Electronic-Parts section of the city to find both items.


 

 One thing though do you really dont need long jumpers since you have to remove cover anyways if im not mistaken or do you have peepholes


----------



## mordy

The jumpers are standard 2.54mm ones. If you have an old hard drive it may be sitting there on the back - standard. The long jumpers I could only find on the Internet (Ebay). I am sure that you can find a source for just 10 of them.
  
 Found a source in Hong Kong:
  
 http://www.ebay.com/itm/10-piece-Standard-Size-2-54mm-Computer-Jumper-with-Long-Handle-Snowy-White-Color-/261573878675?pt=LH_DefaultDomain_0&hash=item3ce704a393
  
 Truth is that for 50c more u can get 100....


----------



## spiderking31

Just got a pair of JHY-6AK5 tubes in the mail today  made my Hytron in February, 1945. They sound beyond incredible! They actually had me tear a few times. Just listening and finally hearing what a tube from 70 years ago sounds like. It's such an honor to own a pair of these. Especially them being NIB!


----------



## rovopio

mordy said:


> The jumpers are standard 2.54mm ones. If you have an old hard drive it may be sitting there on the back - standard. The long jumpers I could only find on the Internet (Ebay). I am sure that you can find a source for just 10 of them.


 
 Thanks mordy! that looks  good, the fact that it's white is nice also.


----------



## mordy

If u check the Ebay listings u will find the same ones in different colors as well - red, green, yellow, black


----------



## rovopio

Been 15 days since I ordered 6hm5 and the opa2107, It took longer than I thought.
 I seriously thought it would arrived before the 4th.


----------



## WilliamLeonhart

Am I correct to assume that you're shipping from eBay? If so, it'll take very long indeed.
  
 Oh and can someone recommend me a opa2107 that's compatible with the I+ and from a trustable vendor? My thanks.


----------



## rovopio

williamleonhart said:


> Am I correct to assume that you're shipping from eBay? If so, it'll take very long indeed.
> 
> Oh and can someone recommend me a opa2107 that's compatible with the I+ and from a trustable vendor? My thanks.


 
 I order from this seller based on the recommendation of gibosi and others on this thread...
  
 ehttp://www.ebay.com/itm/1PC-OPA2107AP-OPA2107-Dual-Low-Noise-OPAMP-DIP8-NEW-/330590537762?pt=LH_DefaultDomain_0&hash=item4cf8bb4822
  
 they send it from Malay so... should be quick.


----------



## WilliamLeonhart

But the page says it's from China... If it were from Malaysia, esp KL... I'd ask my friend to go out and pick it up immediately.


----------



## rovopio

williamleonhart said:


> But the page says it's from China... If it were from Malaysia, esp KL... I'd ask my friend to go out and pick it up immediately.


 
  
 I know yeah! I don't know but when shipped, the tracking number ends with MY. And when I asked Libby, she said it's shipped from Malay.
 Also... I paid $4 extra to get Registered Mail with tracking number, and it did shipped from Malay.
  
 Maybe she has network of op-amps dealer or something? lol


----------



## rovopio

> Originally Posted by *MIKELAP* /img/forum/go_quote.gif


 
  
 Hi Mikelap...
  
 Can I ask you about the crown protector-thingy on your tubes...? What is that crown and where can I buy them?
 cheers... 
  
 ---
 Also to everybody here... my Yugo 6hm5 is currently in customs... Can I ask, should I change the Tube Setting on my Little Dot or does the 6hm5 works directly from the Default 6JI Tube Setting?
  
 cheers...


----------



## MIKELAP

rovopio said:


> > Originally Posted by *MIKELAP* /img/forum/go_quote.gif
> 
> 
> 
> ...


 

 Those tube protectors  i made , but you can get them on ebay under ¨TUBE GUARD PROTECTOR¨  also 6HM5 tube uses the  EF95 setting


----------



## rovopio

mikelap said:


> Those tube protectors  i made , but you can get them on ebay under ¨TUBE GUARD PROTECTOR¨  also 6HM5 tube uses the  EF95 setting


 
  
 May I ask what is the type of tube guard protector i need to pay attention to? There seems to be a lot of tube models on each guard protector, 6922, 12au7, etc. Which ones are good for 6hm5 and say, normal non-tall tubes like the mullard or the voskhod later on?


----------



## TrollDragon

rovopio said:


> May I ask what is the type of tube guard protector i need to pay attention to? There seems to be a lot of tube models on each guard protector, 6922, 12au7, etc. Which ones are good for 6hm5 and say, normal non-tall tubes like the mullard or the voskhod later on?


 
 They really only make the tube cages in two sizes, a 3 ring and a 4 ring. You can use the 3 ring for the 6HM5's and the 4 ring for your 6H6PI tubes in the back.
 Any shorter driver tubes like the 5654 and you will have to cut down a 3 ring so it looks good.


----------



## rovopio

trolldragon said:


> They really only make the tube cages in two sizes, a 3 ring and a 4 ring. You can use the 3 ring for the 6HM5's and the 4 ring for your 6H6PI tubes in the back.
> Any shorter driver tubes like the 5654 and you will have to cut down a 3 ring so it looks good.


 

 This is the 3 ring right?
 http://www.ebay.com/itm/1pc-Tube-Guard-Protector-Cover-For-EL84-6BQ5-6P14-Audio-Amp-Amplifier-Silver-/252016113007?pt=LH_DefaultDomain_0&hash=item3aad54b56f
  
 If i get that, how do I connect them to my Little Dot i+?


----------



## MIKELAP

rovopio said:


> trolldragon said:
> 
> 
> > They really only make the tube cages in two sizes, a 3 ring and a 4 ring. You can use the 3 ring for the 6HM5's and the 4 ring for your 6H6PI tubes in the back.
> ...


 

 At the bottom of the page they show the inner diameter of the cage and the lenght just compare it to your tube You just put the cage over over the tubes


----------



## MIKELAP

Try contacting this vendor and ask for the inner diameter and the lenght  of the cage 
                       http://www.ebay.com/itm/150628567039?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT


----------



## rovopio

Awesome! Thanks Mikelap
  
 So... I want to ask, my 6hm5 arrived. When I plugged them in, only 1 tube flared up in the beginning. The ohter one doesn't flare up at all. (pretty disappointing), i was looking forward to the quasi-firework.
  
 Is that normal or does that mean one of my tube is defect?
 I contacted the seller but haven't heard back...
  
 thanks


----------



## MIKELAP

rovopio said:


> Awesome! Thanks Mikelap
> 
> So... I want to ask, my 6hm5 arrived. When I plugged them in, only 1 tube flared up in the beginning. The ohter one doesn't flare up at all. (pretty disappointing), i was looking forward to the quasi-firework.
> 
> ...


 

 To be honest i dont remember about flare up havent listened in awhile maybe theres my chance to try them again ill get back to you in a few minutes to see if mine flareup or not  but meanwhile if the sound is good there's no problem .


----------



## rovopio

mikelap said:


> To be honest i dont remember about flare up havent listened in awhile maybe theres my chance to try them again ill get back to you in a few minutes to see if mine flareup or not  but meanwhile if the sound is good there's no problem .


 

  Like this?
  
 http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/3540#post_9895766


----------



## gibosi

rovopio said:


> So... I want to ask, my 6hm5 arrived. When I plugged them in, only 1 tube flared up in the beginning. The ohter one doesn't flare up at all. (pretty disappointing), i was looking forward to the quasi-firework.
> 
> Is that normal or does that mean one of my tube is defect?


 
  
 Do you have sound out of the one that doesn't flare up? If so, it's fine. But of course, if not, this is not good....
  
 And if you have no sound, try scraping the pins. I use an X-ACTO knife, not the sharp blade, but the dull top of the blade, to scrape them. And then try again.


----------



## MIKELAP

i just turned LD MK3 on and one tube flares up more than the other one but they sound good .By the way the flaring up is there way of heating up


----------



## rovopio

gibosi said:


> Do you have sound out of the one that doesn't flare up? If so, it's fine. But of course, if not, this is not good....
> 
> And if you have no sound, try scraping the pins. I use an X-ACTO knife, not the sharp blade, but the dull top of the blade, to scrape them. And then try again.


 
  
 feels like one of the side is imbalance to be honest. But it's not detectable enough unless i go loud. And i always listen on a average-to-lowish volume. Like 20 on a Fiio x1 and x3.
  
 I don't own an x-acto knife, and it's not sold here. Will Box Cutter do?


----------



## MIKELAP

rovopio said:


> gibosi said:
> 
> 
> > Do you have sound out of the one that doesn't flare up? If so, it's fine. But of course, if not, this is not good....
> ...


 

 Yes use the dull side of the blade or use plain sandpaper personnally thats what i use


----------



## rovopio

Awesome!
  
 So... one of the headphone side is imbalance, the right headphone sound. But I don't understand... the tube that doesn't flare up is the tube on the left side from me.
  
 Does that even makes sense? Or is that 2 totally unrelated stuff?


----------



## MIKELAP

rovopio said:


> Awesome!
> 
> So... one of the headphone side is imbalance, the right headphone sound. But I don't understand... the tube that doesn't flare up is the tube on the left side from me.
> 
> Does that even makes sense? Or is that 2 totally unrelated stuff?


 

 Try cleaning tube first  then switch them around if the imbalance is on the other side maybe its the tube


----------



## Meddlesome Duck

Hi Headfi-ers,
  
 I've lurked for a few weeks and today I've joined the forum, I didn't want to spam the forum with a question that's most definitely been asked before however I'm struggling to find an appropriate answer. Last week I purchased a little dot i+ amplifier and yesterday I received some nos EF1 tubes. I changed the jumpers, tried them out and everything is clipping, vocals are somewhat clear but everything else is just fuzzy. I've looked at the pins and they do seem dirty, I've ordered some deoxit but I thought I'd ask anyway since it wont be arriving for a few days. Is this a sign the tubes are faulty or do you think the pins oxidization could be the cause.
  
 Kind Regards,
 Duck


----------



## mimart7

meddlesome duck said:


> Hi Headfi-ers,
> 
> I've lurked for a few weeks and today I've joined the forum, I didn't want to spam the forum with a question that's most definitely been asked before however I'm struggling to find an appropriate answer. Last week I purchased a little dot i+ amplifier and yesterday I received some nos EF1 tubes. I changed the jumpers, tried them out and everything is clipping, vocals are somewhat clear but everything else is just fuzzy. I've looked at the pins and they do seem dirty, I've ordered some deoxit but I thought I'd ask anyway since it wont be arriving for a few days. Is this a sign the tubes are faulty or do you think the pins oxidization could be the cause.
> 
> ...


 
  
 Welcome!
  
 Rarely is deoxit needed.  Look at some of the posts above yours about cleaning the pins.  Since you have just received your amp, the tubes you have need need to cook; at least 20 hours.  You will notice things will sound better after that.


----------



## spiderking31

It's very possible that it's just oxidation causing the issue. If after using Deoxit on the pins, and the problem still exists, then I would without say that the tubes are defected. I own 2 pairs of vintage tubes made in 1945 actually, and one tube was defective! I had to have a replacement tube sent to me. And I use these tubes with my MK3  in EF95 mode. They're 6AK5's


----------



## Meddlesome Duck

Appreciate the replies, The stock tubes are working just fine I believe they are the Chinese 6J1's, they are quite noisy tubes very susceptible to magnetic fields it would seem. When I get some time this weekend I'll try running the new tubes in for a few hours, hopefully I will hear some improvements.


----------



## spiderking31

I would rather kill myself than use Chinese 6J1's! Including the Western Electric 403B as well!


----------



## TrollDragon

meddlesome duck said:


> Appreciate the replies, The stock tubes are working just fine I believe they are the Chinese 6J1's, they are quite noisy tubes very susceptible to magnetic fields it would seem. When I get some time this weekend I'll try running the new tubes in for a few hours, hopefully I will hear some improvements.


 

 I recommend you pick up a pair of Yugoslavian 6HM5's from eBay this seller here is excellent!
 http://www.ebay.com/itm/6HM5-6HA5-EC900-export-quality-audio-triode-tube-NOS-FREE-SHIPPING-/300879467071
  
 Pick up three on the off chance one breaks in shipping, otherwise you will have a spare. Once you have the tall Yugoslavian 6HM5's there is no need to look any further, unless you want to get into adapters and dual triodes.


----------



## spiderking31

I own Yugoslavian 6HM5, Mullard M8100 voshkod 6ZH1P-EV, Telefunken 6AK5W Philips EH900S as well as a few pairs from the 1940's dude....don't kid yourself....because Thank you mentioning 6HM5's like their the best, you need to EXPAND YOURSELF away from 6HM5


----------



## TrollDragon

spiderking31 said:


> I own Yugoslavian 6HM5, Mullard M8100 voshkod 6ZH1P-EV, Telefunken 6AK5W Philips EH900S as well as a few pairs from the 1940's dude....don't kid yourself....because Thank you mentioning 6HM5's like their the best, you need to EXPAND YOURSELF away from 6HM5


 

 They are one of the best B7G tubes you can get for the price, I do enjoy the 6N23P & 6BQ7A better.
  
  
  
 Even though I have only used a miniscule amount of tubes (38) in my MK IV, I do know what sounds good to me with my gear and my ears.

 You on the other hand need to learn how to spell Voskhod...


----------



## mab1376

trolldragon said:


> You on the other hand need to learn how to spell Voskhod...


 
  
 Burn!


----------



## spiderking31

Did you take those photos???? Only because it looks like you got those photos off the internet....


----------



## spiderking31

I also own 18 pairs to total, including Tesla 6F32....not 6F32V...I own two pairs of Hytron JHY-6AK5's that were made in 1945. I have a pair of RCA JRC-6AK5's that were made in 1948....and these are the best I've ever heard. Including my Tesla's. So please humor me some more about the 6HM5


----------



## TrollDragon

spiderking31 said:


> Did you take those photos???? Only because it looks like you got those photos off the internet....


 
  
 Yup those are my pictures.
  


spiderking31 said:


> I also own 18 pairs to total, including Tesla 6F32....not 6F32V...I own two pairs of Hytron JHY-6AK5's that were made in 1945. I have a pair of RCA JRC-6AK5's that were made in 1948....and these are the best I've ever heard. Including my Tesla's. So please humor me some more about the 6HM5


 
  
 Good for you, I didn't know it was a contest.

 I'll not waste my time bringing this excellent thread through the muck. This is not the first time you have posted here with your pompous attitude. I really suggest you go back to your FB group where you might be more welcomed.


----------



## spiderking31

Facebook groups seem to be better to me actually. Much more information...thanks Troll! I mean, dragon troll


----------



## gibosi

spiderking31 said:


> I also own 18 pairs to total, including Tesla 6F32....not 6F32V...I own two pairs of Hytron JHY-6AK5's that were made in 1945. I have a pair of RCA JRC-6AK5's that were made in 1948....and these are the best I've ever heard. Including my Tesla's. So please humor me some more about the 6HM5


 
  
 YOUR ears, YOUR gear and YOUR opinion. It's great that YOU have found a sound YOU like.
  
 But as for me, I have around 1000 tubes, pentodes, heptodes, triodes and double triodes. And in my opinion, my ears and my gear, no 6AK5, even those manufactured in the 1940's, is anywhere near the best I have ever heard.
  
 Cheers


----------



## Shaffer

spiderking31 said:


> *Facebook groups seem to be better to me actually.* Much more information...thanks Troll! I mean, dragon troll




I agree. They're pretty much the only place where one can speak freely. Sad.


----------



## mab1376

gibosi said:


> YOUR ears, YOUR gear and YOUR opinion. It's great that YOU have found a sound YOU like.
> 
> But as for me, I have around 1000 tubes, pentodes, heptodes, triodes and double triodes. And in my opinion, my ears and my gear, no 6AK5, even those manufactured in the 1940's, is anywhere near the best I have ever heard.
> 
> Cheers


 
  
 6AV6 sound better than any 6AK5, not to mention 6AH6.
  
 One day he'll move up to big boy club and get some c3gs'
  
 6HM5 is a great tube, slightly too sibilant for me, but YMMV as with anything in the subjective hobby of audio.


----------



## MIKELAP

Littledot mk3 for $210.00 U.S. +15.00 U.S. shipping to Canada on MASSDROP      2days left


----------



## mordy

*Hi All,*
  
*For years a number of people commented on how nice, informative and pleasant our forum is. Questions that had been asked many times before were patiently and lovingly answered again and again.*
  
*PLEASE - everybody is entitled to their personal opinion regarding what they like and don't like, and we respect this - we all have different equipment, ears and personalities. BUT PLEASE - no personal attacks and jabs.*
  
*A majority of people may reach a consensus on a group of tubes that are the best sounding (especially after listening to dozens of different tubes), but if somebody feels that something that most of us disliked is exactly what they like - it's just fine; nothing wrong with that. We must respect each other, and not vent any negative feelings.*
  
*We are here to help each other, share ideas and information, but not to be judgmental.*


----------



## spiderking31

I apologize, and you have a valid point


----------



## gibosi

@spiderking31
  
 Very frankly, the 6HM6 is not my favorite tube in the LD either. But when beginners ask for advice, I never hesitate to suggest the 6HM5 and the Voskhod because they are cheap and lots of people like them. And it helps beginners to begin to learn what they like and don't like.
  
 Now, 1940's era 6AK5s are pretty rare. For those of us who are into tube porn, do you have any pictures of your Hytrons and RCAs?


----------



## spiderking31

My Hytron JHY-6AK5's made in February, 1945
And my RCA JRC-6AK5's made in 1948


----------



## mordy

Hi S31,
  
 No apologies needed - just wanted that the forum should be non judgmental and informative and helpful. Thanks for the pictures.


----------



## Meddlesome Duck

I mentioned earlier I was having issue with some EF91 tubes in my little dot i+ well the seller has sent me a second pair of tubes next day delivery. I'm trying them now and it's the same problem. The sound is very quiet I have to set my source to 100% and my little dot to 20% in order to get decent level for listening and even then the bass is not really there and the highs clip slightly. If I increase the little dot's volume everything slowly starts clipping. Has anyone encountered a similar issue, the pins again are slightly dirty, the tubes are CV5377.


----------



## i luvmusic 2

To my ears the 6HM5 is the best 7 pins i've used for my MK III and 1+  and the best tubes for me so far is the C3g/6SN7 combo,maybe he/she should try C3g.


----------



## gibosi

meddlesome duck said:


> I mentioned earlier I was having issue with some EF91 tubes in my little dot i+ well the seller has sent me a second pair of tubes next day delivery. I'm trying them now and it's the same problem. The sound is very quiet I have to set my source to 100% and my little dot to 20% in order to get decent level for listening and even then the bass is not really there and the highs clip slightly. If I increase the little dot's volume everything slowly starts clipping. Has anyone encountered a similar issue, the pins again are slightly dirty, the tubes are CV5377.


 
  
 Since you have experienced this with two sets of EF91 tubes, I doubt that the tubes are at fault. I now suspect that the J1 and J2 jumpers are not making a good contact. And there is a way you can test this. First you will need two short pieces of small gauge stranded wire, 22 gauge or smaller. Strip both ends and in each socket insert one end in pin-hole 6 and the other in pin-hole 7. Do this in both sockets. And then carefully insert your tubes. This is precisely what the J1 and J2 jumpers do, they strap 6 and 7 together.
  
 Scroll to the bottom of Acapella11's post below, for pictures and diagrams to help you understand "strapping pins together in the socket.". Also, note that in the the LD 1+, the sockets are mirrored, left to right, whereas, in the LD III and IV, they have the same orientation, left to right.
  
 http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/1140#post_9392055
  
 After strapping, if the tubes sound good, then J1 and J2 are not making good contact, and you might want to open your amp up and clean them and also make sure the jumpers are tight and secure.
  
 Good luck! 
  
 Edit: Ummm... You did open your amp up and jumper J1 and J2 before running your EF91?, didn't you?


----------



## Meddlesome Duck

gibosi said:


> Edit: Ummm... You did open your amp up and jumper J1 and J2 before running your EF91?, didn't you?


 
  
 Hi gibosi,
  
 Thanks for the reply, referring to the little dot i+ reference guide it says I should have both jumper J1 and J2 closed for EF91 tubes.
 On a second glance at the amp I've noticed the gain is currently running in an open circuit which is probably too high for my fidelio x2's I also noticed two yellow wires connecting both tube sockets. I bought this amp pre-owned and the guy I bought it off never mentioned any modifications to the amplifier. The jumper housing is missing so I can't alter the gain for the moment I've had to order housing online. Below is a picture of my amp.
  
 Green: J3 + J4 (Gain)
 Purple: J1 + J2 (Housing installed)
 Red: Mystery wire
  
 Picture of my amp
http://postimg.org/image/j7vxsdlfj/
  
 little dot i+ Reference Guide
https://dl.dropboxusercontent.com/u/6037680/Little%20Dot%20I%2B%20Reference%20Guide.pdf


----------



## gibosi

spiderking31 said:


> My Hytron JHY-6AK5's made in February, 1945
> And my RCA JRC-6AK5's made in 1948


 
  
 Nice glass! And I am surprised to see that you were able to pick them up for a very reasonable price. Well done!


----------



## spiderking31

Thanks!  the Hytron's, I have 2 pairs of those, and 1 pair of the RCA's


----------



## Meddlesome Duck

gibosi said:


> Edit: Ummm... You did open your amp up and jumper J1 and J2 before running your EF91?, didn't you?


 
  
 Thanks for the reply, this is terribly embarrassing, I bought this amp second hand, the jumpers for gain control were missing which the pins are soldered directly onto the circuit board. J1 and J2 have plastic at the bottom of the pins before they touch the circuit board. I mistook these pieces of plastic as the jumpers. Oh dear, I realised last night on closer inspection when I tried to remove what I thought were jumpers.
  
 The tubes are sounding great I no longer have a slight buzzing sounds in the background, everything is very clear now.
  
 Appreciate the help.


----------



## gibosi

Gread! Glad to hear that it was something simple. Enjoy!


----------



## gibosi

meddlesome duck said:


> On a second glance at the amp I've noticed the gain is currently running in an open circuit which is probably too high for my fidelio x2's I also noticed two yellow wires connecting both tube sockets. I bought this amp pre-owned and the guy I bought it off never mentioned any modifications to the amplifier. The jumper housing is missing so I can't alter the gain for the moment I've had to order housing online. Below is a picture of my amp.


 
  
 The yellow wires power the tube heaters. The heater supply circuit is completely separate from the circuitry that actually runs the amplifier. While I haven't popped my amp open in a long time, everything looks normal to me.


----------



## CEddy10165

Thank you for taking the time to share you findings - VERY helpful.


----------



## mimart7

Sadly, my wife tells me to stop buying tubes.  I guess I have my purchases shipped to work, lol.


----------



## raybone0566

mimart7 said:


> Sadly, my wife tells me to stop buying tubes.  I guess I have my purchases shipped to work, lol.


My wife bought me this amp through the current massdrop promotion. She had no idea what tube rolling was. I'll be recieving all my tubes at work


----------



## mimart7

raybone0566 said:


> My wife bought me this amp through the current massdrop promotion. She had no idea what tube rolling was. I'll be recieving all my tubes at work


 
  
 A very wise decision


----------



## mordy

My wife asked me why I have so many of those little glass things - didn't really know what to answer, so I told her that they are all a little different, and I am looking for audio perfection....
  
 Funny thing is that they seem to appreciate in value, but unfortunately not so easy to sell LOL


----------



## Meddlesome Duck

I just received my second set of tubes, Canadian made northern electric NE-408A. I'm very surprised what a difference they have made, it blows both the stock 6J1 and the EF91 CV3577 out the water. Using Philips Fidelio x2 I christened them with the track Elegia by new order, the first minute of the track fades in with low bass tones with the EF91's It generates a subwoofer style bass that's very airy and somewhat irritating, the 408A's dials this way down, it actually allows the bass to build up and when it does it's very tight and clean, the mids and highs are very clear now too. During the middle of the track you have a few voices in the background which are very faint I could barely make these out with the EF91's genuinely forgot about these until last night, the 408A's made them stand out thought I could hear someone whispering in my ear very creepy. Overall it's a very bright tube and I absolutely love them, these will definitely be my daily drivers from now on. Now just eagerly awaiting my next batch of tubes the Russian made 6HM5 which where mentioned in previously in this thread.


----------



## fragger008

Hello all,
  
 First of all, thanks for this topic on wich we can find a huge amount of information concerning tube rolling !
  
 I've recently bought a Little Dot I+ for my AKG Q701. I've bought it with the standard 6J1 tubes and I found it souded great !
  
 Following the comments of many people I decided to buy a pair of Voskhod 6ZH1P-EV. I've also ordered an OPA2107 that I'm still waiting for.
  
 I've received the voskhod yesterday and I must say that I'm a bit disappointed about them. In fact, the mids and trebles are really detailed, and more "clean" than the 6J1, but I also find that there is less bass than with the 6J1, and maybe too loud high-mids. It is exactly what are, from my point of view, the 2 weak points of the Q701.
  
 But what is strange is that I read that Voskhod have really good bass, so I wonder why for the moment I found the bass less present than with the standard 6J1 ? Do they need some burn in ?
  
 Or maybe the Voskhod are well adapted for Sennheiser earphones, but less for AKG ?
  
 What do you think ?
  
 Thanks for your help.


----------



## MIKELAP

fragger008 said:


> Hello all,
> 
> First of all, thanks for this topic on wich we can find a huge amount of information concerning tube rolling !
> 
> ...


 

 Arent the 701 bright or neutral to start with ? What i found warmed up the sound on my MK3 with my SENNS HD800 was using the 6sn7 variety as power tubes but i needed an adapter for that  but if i remember correctly i dont remember the VOSHKOD as being bassy but being more on the brighter, clean sounding  side .And consensus on burnin is 100+ hours .Personnally i did not like them to neutral if i remember correctly its been awhile since i listened to those .As they say different strokes for different folks . Check out page 585 post # 8766


----------



## mimart7

fragger008 said:


> Hello all,
> 
> First of all, thanks for this topic on wich we can find a huge amount of information concerning tube rolling !
> 
> ...


 
  
 I had to let these tubes cook for more than 30 hours before they started to sound good.  Most if not all tubes benefit from a minimum of 20 hours of cooking. I have had tubes take well over 50 hours before they started to shine.


----------



## fragger008

Thanks for your answers. 
For the burn in, do I need to put sound coming to the LD ? Or just switching the amp ON is ok ?


----------



## mimart7

mimart7 said:


> I had to let these tubes cook for more than 30 hours before they started to sound good.  Most if not all tubes benefit from a minimum of 20 hours of cooking. I have had tubes take well over 50 hours before they started to shine.


 
  
 For the burn in, you only need to have your headphones connected to the amp, and obviously have it powered up.  There is no need to have music playing.


----------



## fragger008

Oh okay so I need to plug in the headphone even if I don't play music ? I was thinking it was not necessary... Thank you for your help


----------



## mordy

Hi fragger 008,
  
 Just close your eyes and count to 120 - just joking; the Voskhods really need some 110-120 hours of burn in to mellow out, and they will really change, all for the better.
  
 IMHO opinion it makes sense to play music or white noise when burning in the tubes; don't know if just leaving the amp on is the best way to go. I used a repeating track playing different frequencies that I got from jlab - it was free.
  
 http://www.jlabaudio.com/pages/audio-burn-in
  
 Good luck!


----------



## mimart7

mordy said:


> Hi fragger 008,
> 
> Just close your eyes and count to 120 - just joking; the Voskhods really need some 110-120 hours of burn in to mellow out, and they will really change, all for the better.
> 
> ...


 
  
 It has nothing to do with audio playing with the tubes, it actually is related to the tubes getting warm, hence the term "cooking."


----------



## fragger008

Ok thanks for your answers 
  
 So I'm waiting for a pair of matched Voskhod as the one that I ordered was not, and I will do the "cooking" of the Voskhof directly with these matched pair.


----------



## MIKELAP

fragger008 said:


> Ok thanks for your answers
> 
> So I'm waiting for a pair of matched Voskhod as the one that I ordered was not, and I will do the "cooking" of the Voskhof directly with these matched pair.


 

 By the way in our amps you dont need to buy match pairs i made that mistake once .as long as they are same brand and similar structure its good enough with matched pairs you just overpay for nothing


----------



## fragger008

mikelap said:


> By the way in our amps you dont need to buy match pairs i made that mistake once .as long as they are same brand and similar structure its good enough with matched pairs you just overpay for nothing


 
  
 Yes in fact I get this information after ordering a matched pair, but for next time I will be aware of that and I will not make the mistake anymore


----------



## mordy

Hi mimart7,
  
 I have a friend who is a retired A/V engineer and I asked him about burning in tubes. He agreed with you; it is just a case of burning off extra electrons, so I shall stand corrected.
  
 Apparently burn in with music or white noise etc is warranted for speakers and headphones with moving parts, but that's another story.


----------



## raybone0566

I have my mass drop mkiii due to arrive on Wednesday. Can anyone give me the numbers for the coal hod tubes & the best place to score them.thanks


----------



## raybone0566

raybone0566 said:


> I have my mass drop mkiii due to arrive on Wednesday. Can anyone give me the numbers for the coal hod tubes & the best place to score them.thanks


I meant voshkod. Damn smart phone.


----------



## bluewrx1025

This is a pretty reputable dealer on ebay. I'm about to pull the trigger on this set soon for my Little Dot I+
  
  
 http://www.ebay.com/itm/291043635707?_trksid=p2060353.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT


----------



## mimart7

bluewrx1025 said:


> This is a pretty reputable dealer on ebay. I'm about to pull the trigger on this set soon for my Little Dot I+
> 
> 
> http://www.ebay.com/itm/291043635707?_trksid=p2060353.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT


 

 You can do better on ebay, than that price


----------



## gibosi

bluewrx1025 said:


> This is a pretty reputable dealer on ebay. I'm about to pull the trigger on this set soon for my Little Dot I+
> 
> 
> http://www.ebay.com/itm/291043635707?_trksid=p2060353.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT


 
  
 In the past, I bought several pairs from this vendor:
  
 http://www.ebay.com/itm/1-pc-or-more-6J1P-EV-EF95-6F32-6AK7-gold-plated-and-platinized-grid-NOS-NIB-/131455349947
  
 Matching drivers is not required in the LD, so just buy two, or three, or four.


----------



## bluewrx1025

gibosi said:


> In the past, I bought several pairs from this vendor:
> 
> http://www.ebay.com/itm/1-pc-or-more-6J1P-EV-EF95-6F32-6AK7-gold-plated-and-platinized-grid-NOS-NIB-/131455349947
> 
> Matching drivers is not required in the LD, so just buy two, or three, or four.


 
 Ok awesome. Thanks for the link! Any problems coming from Russia?


----------



## fragger008

Hello all,
  
 I've received a pair of Svetlana 6J1P-E of 1966, with 2 pairs of Voskhod 6ZH1P-EV, one from 1978 and one from 1981.
  
 I have to burn in all of them, but I don't know the Svetlana, the seller has put it as a gift in the package, do you know them ? What kind of sound compared to the Voskhod ?
  
 And will I normally a sound color different from the 2 pairs of Voskhod ? Is the year, 1978 or 1981 in the kind of sound ?
  
 Thank you for your answer


----------



## MIKELAP

bluewrx1025 said:


> This is a pretty reputable dealer on ebay. I'm about to pull the trigger on this set soon for my Little Dot I+
> 
> 
> http://www.ebay.com/itm/291043635707?_trksid=p2060353.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT


 

 Before i was talking about a mistake i made well this seller is it ,not because of reputation but pricewize you can do alot better than that .


----------



## gibosi

bluewrx1025 said:


> Ok awesome. Thanks for the link! Any problems coming from Russia?


 
  
 No problems at all, other than shipping is a bit slow.....


----------



## gibosi

fragger008 said:


> Hello all,
> 
> I've received a pair of Svetlana 6J1P-E of 1966, with 2 pairs of Voskhod 6ZH1P-EV, one from 1978 and one from 1981.
> 
> ...


 
  
 I don't know that anyone has directly compared the Svetlana and Voshkods and posted their observations here. Further, I don't know that anyone has directly compared and posted about different years of Voshkods either.
  
 But yes, the year of manufacture can and often does make a difference in the sound. For example, in a different amp (Lyr), various years of Voshkod 6N23P have been compared and there is some consensus that those manufactured in the mid-1970s are the best. So I would expect that if you were able to obtain samples of Voshkod 6ZH1P-EV manufactured over any 10 year period, it is almost a given that they will not all sound the same.
  
 And the same is true regarding other manufacturers, whether American, European or Russian. Construction techniques and materials were constantly changing over the years, and thus the sonics were changing as well.


----------



## mordy

As a rule, Russian tubes made before the fall of Communism seem to be of better quality than later ones. In this category I am not including Tung Sol re-issue tubes and similar ones that are being manufactured today.
  
 If you can buy NOS Russian tubes, try to get from the 70s rather than the 80's when it come to tubes for the Little Dot.
  
 What Mikelap and Gibosi have pointed out is absolutely true - the tube you are paying $1 for from Russia is the same tube that goes for $18 elsewhere. The only drawback ordering from the Soviet Union is the shipping time, which can take 4 weeks to the US.
  
 (And in recognition of Trolldragon's and Oskari's efforts on this blog, the correct spelling is VOSKHOD, no vosh or whatever. And that famous maker is called Philips, not Phillips like in screwdriver - I hope I got it right LOL.)
  
  





  
 This picture shows the difference between Philips and Phillips:
  




  
 Have fun!


----------



## Rossliew

Just received my pair of C3G adapters and rolled them in...sounded pretty bad when paired with some generic 6SN7s as power tubes but improved noticeably when i used a pair of 6N1Ps as power tubes. There's no noticeable hum either.

Actually i kinda preferred the sound of 6SN7/12AU7 (single tube driving both channels with MIKELAP's adapter) pairing but there's some serious humming going on in the background which is irritating. Not sure if this is due to some ground loop issues or just sensitive tubes catching all the stray RF transmissions...


----------



## fragger008

Thanks for your answers 
  
 Now I have to wait for the burn in of these 3 pairs of tubes that I have (it will take a long time if I have to wait for 100h for each pair...) and after I will try to give my opinion about the sound if I can see a difference ! ^^ (and also if I can translate it in english because I'm from France  ).
  
 Just another question : all the tubes that I've received are in a new packaging (home made I think), and the tubes seem really brand new, their appearance are really shiny, both for the glass part and for the contacts.
 I wonder how the appearance can be so shiny for tubes that are approximately 50 years old.
 Could it be fake ones ? Are there a lot of fake tubes ? Or is it the "normal shape" if they have been well conserved ?
 Mine are coming from Russia so I assume that the probability of fake is less than if I order from other countries (for russian tubes of course) ?


----------



## mimart7

rossliew said:


> Just received my pair of C3G adapters and rolled them in...sounded pretty bad when paired with some generic 6SN7s as power tubes but improved noticeably when i used a pair of 6N1Ps as power tubes. There's no noticeable hum either.
> 
> Actually i kinda preferred the sound of 6SN7/12AU7 (single tube driving both channels with MIKELAP's adapter) pairing but there's some serious humming going on in the background which is irritating. Not sure if this is due to some ground loop issues or just sensitive tubes catching all the stray RF transmissions...


 
  
 Try reseating the tubes and adapter.  If you are using a power strip, try moving plug from one outlet on the adapter to another.


----------



## mimart7

fragger008 said:


> Thanks for your answers
> 
> Now I have to wait for the burn in of these 3 pairs of tubes that I have (it will take a long time if I have to wait for 100h for each pair...) and after I will try to give my opinion about the sound if I can see a difference ! ^^ (and also if I can translate it in english because I'm from France  ).
> 
> ...


 
  
 Countless tubes have been made there, so odds are they are the real deal.


----------



## Rossliew

mimart7 said:


> Try reseating the tubes and adapter.  If you are using a power strip, try moving plug from one outlet on the adapter to another.


 

 Thanks for the advice will try it out...after my listening session with the C3GS


----------



## MIKELAP

rossliew said:


> Just received my pair of C3G adapters and rolled them in...sounded pretty bad when paired with some generic 6SN7s as power tubes but improved noticeably when i used a pair of 6N1Ps as power tubes. There's no noticeable hum either.
> 
> Actually i kinda preferred the sound of 6SN7/12AU7 (single tube driving both channels with MIKELAP's adapter) pairing but there's some serious humming going on in the background which is irritating. Not sure if this is due to some ground loop issues or just sensitive tubes catching all the stray RF transmissions...


 

 I guess im lucky never had any hum problem with any of the adapters that includes the ones i made for the C3G'S Ive been using 6SN7 and C3G combo for awhile now and it sounds good i guess your problem is interference somewhere in the chain not pleasant for shure


----------



## Rossliew

Yeah Mike, methinks the power source is not too clean or there's too much interference from RF around the house...oh well, back to stock-ish tubes LOL


----------



## mab1376

mikelap said:


> I guess im lucky never had any hum problem with any of the adapters that includes the ones i made for the C3G'S Ive been using 6SN7 and C3G combo for awhile now and it sounds good i guess your problem is interference somewhere in the chain not pleasant for shure


 
 I've been using the same combo for well over a year, it's my HD650's best friend. I'm still using TungSol 6SN7 re-issue. I really wanna complete it with some nice VT-231 one day.
  
 That rig hasn't got much love recently with my new HE-500 and Lyr2.


----------



## mimart7

Keep the amp away from routers, phone bases, modem, etc.  The outlet might not be grounded, too.


----------



## hypnos1

rossliew said:


> Just received my pair of C3G adapters and rolled them in...sounded pretty bad when paired with some generic 6SN7s as power tubes but improved noticeably when i used a pair of 6N1Ps as power tubes. There's no noticeable hum either.
> 
> Actually i kinda preferred the sound of 6SN7/12AU7 (single tube driving both channels with MIKELAP's adapter) pairing but there's some serious humming going on in the background which is irritating. Not sure if this is due to some ground loop issues or just sensitive tubes catching all the stray RF transmissions...


 
  
 Hi R.
  
 You would appear to be one of the few very unlucky ones where something in the system/environment doesn't agree with the C3gs...it always saddens me to hear of such cases - denying people the wonderful potential of this tube...but don't forget they keep improving up to well over 50 hrs burn-in, as will the adapters (which may well not be helping to achieve full potential, alas!). It might just be worth seeking out any potential source of interference, or upgrading the power cord etc...and then giving them more time.
  
 I wish you the best of luck...
  
 Cheers!


----------



## mab1376

hypnos1 said:


> Hi R.
> 
> You would appear to be one of the few very unlucky ones where something in the system/environment doesn't agree with the C3gs...it always saddens me to hear of such cases - denying people the wonderful potential of this tube...but don't forget they keep improving up to well over 50 hrs burn-in, as will the adapters (which may well not be helping to achieve full potential, alas!). It might just be worth seeking out any potential source of interference, or upgrading the power cord etc...and then giving them more time.
> 
> ...


 
  
 They can't be paired with sensitive cans, my T70 have a slight buzz with the c3gs, my HD650 sound absolutely amazing with them.


----------



## hypnos1

mab1376 said:


> They can't be paired with sensitive cans, my T70 have a slight buzz with the c3gs, my HD650 sound absolutely amazing with them.


 

 Hi mab...long time no speak, mon ami - I'm afraid all my time and energies are now with my Elise...the MKIV SE sits pining in the attic I'm ashamed to say (I feel so _guilty_!).
  
 So your T70s buzz with the C3gs?...strange... I have the T1s, which have higher impedance but about the same sensitivity, and the sound I am now getting is truly wonderful. And have never had the slightest hint of buzz.
  
 The only possible occasional 'niggle' with the Siemens/T1 combo can come with recordings that are excessively biased in the treble arena, or with those unfortunates who are _extremely_ sensitive to certain treble frequencies. But this can usually be remedied by either slightly modding the T1s, or by careful choice of power tubes...depending as well of course on the source/DAC.
 I personally found another way of 'taming' the uber-extended treble, which also brought other unexpected benefits : as you know, I love my pure silver in the C3g adapters but that occasional sharpness got me thinking about the possibility of helping the silver by adding some single-crystal copper wire...and it worked!...smoother treble; more extended bass and mids, with even greater tonal range throughout the entire frequency spectrum. And as a tongue-in-cheek experiment I also added gold wire to them (only on g1 though!), and the best qualities of the other two metals were married together in a wonderful synergy...I was gobsmacked lol!
 This, especially when coupled with the fabulous GEC CV2523 (6AS7G) powers in my Elise has taken this amp to a whole new level...just as we did with our LDs...
	

	
	
		
		

		
			





...
  
 Oh happy day...
	

	
	
		
		

		
		
	


	



  
 CHEERS!


----------



## mab1376

hypnos1 said:


> Hi mab...long time no speak, mon ami - I'm afraid all my time and energies are now with my Elise...the MKIV SE sits pining in the attic I'm ashamed to say (I feel so _guilty_!).
> 
> So your T70s buzz with the C3gs?...strange... I have the T1s, which have higher impedance but about the same sensitivity, and the sound I am now getting is truly wonderful. And have never had the slightest hint of buzz.
> 
> ...


 
 Wow that Elise amp looks really nice, kinda like a single ended WA22 with no tube rectifier, jealous! Most of my listening is now on my Lyr2 with my HE-500, got some nice Valvo red E88CC.
  
 The T70 mostly didn't like the power of the 6SN7, they worked much better with the 6SU7GTY (6SL7) I picked up, gain 3 too! They really don't need much power. The cg3 is just so detailed you can hear the buzz even though it was subtle. 
  
 Good to hear from you!


----------



## hypnos1

mab1376 said:


> Wow that Elise amp looks really nice, kinda like a single ended WA22 with no tube rectifier, jealous! Most of my listening is now on my Lyr2 with my HE-500, got some nice Valvo red E88CC.
> 
> The T70 mostly didn't like the power of the 6SN7, they worked much better with the 6SU7GTY (6SL7) I picked up, gain 3 too! They really don't need much power. The cg3 is just so detailed you can hear the buzz even though it was subtle.
> 
> Good to hear from you!


 

 Nice to see you're still in head-fi land mab, and that you appear to be enjoying your Lyr2.
  
 This tube (and combination thereof)/amp/headphone synergy thing sure can be a very mysterious minefield, lol! Which makes these threads a godsend for at least _trying_ to avoid making too many (expensive!) blunders...but still we make them!! (All to aid in the advancement of what WAS a dying area of hi-fi, but which certainly now has quite an extensive following...
	

	
	
		
		

		
		
	


	




...especially with so many great guys in threads like this one...).
  
 As for the Elise, it has turned out to be beyond my greatest hopes and expectations...never even dreamt the Feliks-Audio guys would actually take up my suggestion for the amp in the first place! And everyone else so far seems to be delighted - if not ecstatic! - with it (thank goodness!! 
	

	
	
		
		

		
		
	


	




).
  
 Keep the faith, lol!
 CJ


----------



## darksolstice

been lurking here for awhile, just thought I would share this:
 I have been looking at a Little Dot Mark II forever daydreaming, three weeks ago I came home to a package on the porch? My Wife had ordered me one !
	

	
	
		
		

		
		
	


	




 First thing I did (besides thanking her !) I ordered some GE JAN 5654W 6AK5 tubes , listened to the stock tubes for awhile ,meh too subdued for my taste, rolled in the 5654W's and oh my god ! sweet wonderful sound
	

	
	
		
		

		
		
	


	




I can hear fine details I never heard in records I have had for years , next I'm getting some Russian 6N6P-IR to use as power tubes. My wife supports my hobby completely, I am blessed to have her ...
	

	
	
		
		

		
		
	


	




  My cans are Sennheiser HD598's, hmmm may have to buy some new cans also ,any suggestions under $500 ?


----------



## TomNC

@darksolstice
  
    I am using the exactly same type of power tubes with my LD MKIII. I had used 5654W driver tubes for a while and liked them very much. But if your LD MKII can take C3gs with some adapters, it is a significant update, which is what I have now. I am quite satisfied. Cost is about $150 though.


----------



## darksolstice

tomnc said:


> @darksolstice
> 
> I am using the exactly same type of power tubes with my LD MKIII. I had used 5654W driver tubes for a while and liked them very much. But if your LD MKII can take C3gs with some adapters, it is a significant update, which is what I have now. I am quite satisfied. Cost is about $150 though.


 

 I have read a huge amount of this thread but I'm not sure if the MKll can run C3gs, but if it can I'm all about the sound quality.


----------



## d4rkch1ld

It can use it, but in my humble opinion its not worth it if u dont use 6AS7 type power tubes.


----------



## buldogge

darksolstice said:


> I have read a huge amount of this thread but I'm not sure if the MKll can run C3gs, but if it can I'm all about the sound quality.


 
  
  


d4rkch1ld said:


> It can use it, but in my humble opinion its not worth it if u dont use 6AS7 type power tubes.


 

 I use C3Gs on my MK II in conjunction with 6SN7s and think it's quite "worth it".
  
 -Mark in St. Louis


----------



## MIKELAP

buldogge said:


> darksolstice said:
> 
> 
> > I have read a huge amount of this thread but I'm not sure if the MKll can run C3gs, but if it can I'm all about the sound quality.
> ...


 

 I also like the combo been on the mk3 for months now


----------



## mab1376

mikelap said:


> I also like the combo been on the mk3 for months now


 
 same combo i use in my MK IV for over a year now, no looking back.


----------



## Cmahesh

What is the best tube for classical music? Voshkod 6ZH1P-EV, Mullard M8100, or Mullard M8161? I am using Little Dot 1+ amp and Sennheiser HD 598 headphone.


----------



## Shaffer

cmahesh said:


> What is the best tube for classical music? Voshkod 6ZH1P-EV, Mullard M8100, or Mullard M8161? I am using Little Dot 1+ amp and Sennheiser HD 598 headphone.




I took a look at some of your other posts. I mean, Classical music spans +500 years and includes everything from bombastic orchestral works to Early Music featuring [very quiet] lutes, and everything in between. It was good to see you define your tastes. Given your predisposition for the violin, I'd suggest the Mullard M8100. Good luck.


----------



## kaboomooo

Telefunken is the best, most balanced and I don't care what you said but those Germans they made the best tube.


----------



## Shaffer

kaboomooo said:


> Telefunken is the best, most balanced and* I don't care what you said* but those Germans they made the best tube.




Who are you talking to? 

FWIW, I had a pair of Telefunken in my old LDIII and frankly used other tubes more often. It's not as if they were bad sounding, just nothing terribly special.


----------



## kaboomooo

I have been tube rolling for a few year. The only amp that I heard that does not sound good with my Telefunken is made in China. Thank you very much


----------



## Shaffer

kaboomooo said:


> I have been tube rolling for a few year. The only amp that I heard that does not sound good with my Telefunken is made in China. Thank you very much




Then, why are you in a Little Dot thread?


----------



## kaboomooo

shaffer said:


> Then, why are you in a Little Dot thread?


 
I am  just talking about my experience with tube rolling in general. I have not hear of Little Dot my self. But would like to try it out one day since you think it may be worthwhile my good sir


----------



## gulakpi

shaffer said:


> Then, why are you in a Little Dot thread?


 

 Very good question indeed!


----------



## darksolstice

it only took 1 week but I have read all 654 pages !!


----------



## SonicTrance

darksolstice said:


> it only took 1 week but I have read all 654 pages !!




Impressive! It took me a couple of months and the thread was about 600 pages then. I was only able to read about an hour each day though.


----------



## gulakpi

I started reading this thread say, 3 weeks ago, and now I've barely finished 1/4 of it!  You are fast!


----------



## gulakpi

This is a super useful and practical thread, and my thanks to all the contributors!


----------



## i luvmusic 2

BUT LITTLEDOT IS MADE IN CHINA.....................


----------



## mordy

Hi DarkS,
  
 Very admirable - I often felt that the best way to read this very useful thread is to read it backwards chronologically. So many great tubes were discovered over time, but it seems that most people just read a couple of pages in the beginning.
  
 Just finished a different thread (6AS7G tube rollers) of some 160 pages - took me two weeks.
  
 One beautiful thing about these threads is that people are very patient and helpful and genuinely try to help each other.


----------



## mordy

Yes, i luvmusic 2, it is made in China, built like a tank, and a tremendous value. I have thrown all kinds of stuff at it for several years, and it is holding up very well without any problems.
  
 Finally graduated to the Elise, which is another great value and on a different, higher level, but at three times the cost. There is no going back, but I will always remember the Little Dot MKIII very fondly. I learned a lot from my time with the MKIII, never having had a tube amp before - great fun, which is reflected in this thread.


----------



## i luvmusic 2

mordy said:


> Yes, i luvmusic 2, it is made in China, built like a tank, and a tremendous value. I have thrown all kinds of stuff at it for several years, and it is holding up very well without any problems.
> 
> Finally graduated to the Elise, which is another great value and on a different, higher level, but at three times the cost. There is no going back, but I will always remember the Little Dot MKIII very fondly. I learned a lot from my time with the MKIII, never having had a tube amp before - great fun, which is reflected in this thread.


 
 The MK III is not my first tube amp however it's the first amp that i rolled some tubes and butchered it thanks to all of the great guys in here i've learned a lot from this thread.


----------



## i luvmusic 2

BTW where is TD?


----------



## darksolstice

I have always been a fast reader and have made notes on the tubes I am interested in so it was a fantastic read, thanks to all to have tried these tubes so all I have to do is buy off your recommendations ! next purchase is the 6HM5 EC900 EI Yugoslavia


----------



## mordy

Hi darksolstice,
  
 Well done! Next, get two adapters and an inexpensive pair of Sylvania 6SN7 tubes for power tubes. It will upgrade the LD at least two levels; all plug and play.


----------



## darksolstice

mordy said:


> Hi darksolstice,
> 
> Well done! Next, get two adapters and an inexpensive pair of Sylvania 6SN7 tubes for power tubes. It will upgrade the LD at least two levels; all plug and play.


 
 my cans are Sennheiser HD 598 , impedance is 50 ohms, can I use those with the 6SN7 tubes?


----------



## hypnos1

mordy said:


> Yes, i luvmusic 2, it is made in China, built like a tank, and a tremendous value. I have thrown all kinds of stuff at it for several years, and it is holding up very well without any problems.
> 
> Finally graduated to the Elise, which is another great value and on a different, higher level, but at three times the cost. There is no going back, but I will always remember the Little Dot MKIII very fondly. I learned a lot from my time with the MKIII, never having had a tube amp before - great fun, which is reflected in this thread.


 
  
 Ditto m...I would never have got anywhere near proposing the idea of Elise if it weren't for the fabulous guys here these past 2 years...great thread and great words of wisdom/advice - not just about tubes, either!!
  
 So WELL DONE to those new here, and who manage to plough through the entire thread...and as you say mordy, it's a good idea to sometimes work _backwards_ - can certainly cut a lot of (possibly expensive) corners!!


----------



## gulakpi

Thank you for the suggestion to read backwards!
 To appreciate the efforts from all those who contributed in this post in the past several years, I still enjoy reading it from Page 1, and taking notes along!
 My Mk4 came in just a few months ago, and with this amazing thread, I still can be with you guys on this journey/quest to roll these tubes for the best sound with least money/efforts.
 This is an exceptional thread, with tons of information, and extremely friendly.  Many of the pioneers/contributors have been sharing their valuable experiences and were so patient with the new comers!


----------



## hypnos1

gulakpi said:


> Thank you for the suggestion to read backwards!
> To appreciate the efforts from all those who contributed in this post in the past several years, I still enjoy reading it from Page 1, and taking notes along!
> My Mk4 came in just a few months ago, and with this amazing thread, I still can be with you guys on this journey/quest to roll these tubes for the best sound with least money/efforts.
> This is an exceptional thread, with tons of information, and extremely friendly.  Many of the pioneers/contributors have been sharing their valuable experiences and were so patient with the new comers!


 
  
 Hi gulakpi...it always warms the heart when new blood takes such trouble to read and appreciate the efforts (and friendliness) of all those who have indeed contributed to this thread for some time now...ENJOY your MKIV - I certainly did mine...
	

	
	
		
		

		
			




  
 CJ


----------



## Trancedoc

I just joined headfi.  I have a Little Dot Mk3 with 6HM5 driver tubes and 5687WA power tubes.  It sounds very good with my low impedance headphones.  I wanted to upgrade further and ordered C3G drivers.  My question is what would be the best power tube to use with the C3Gs and low impedance headphones?  The chart on page 585 indicates the 6SN7 and 6SL7 do not work with low impedance cans.


----------



## gibosi

trancedoc said:


> I just joined headfi.  I have a Little Dot Mk3 with 6HM5 driver tubes and 5687WA power tubes.  It sounds very good with my low impedance headphones.  I wanted to upgrade further and ordered C3G drivers.  My question is what would be the best power tube to use with the C3Gs and low impedance headphones?  The chart on page 585 indicates the 6SN7 and 6SL7 do not work with low impedance cans.


 
  
 If the 5687 is driving your low-Z cans very well, then I suggest that you leave it in. It will work perfectly fine with the C3g.


----------



## Trancedoc

I had a hard time finding 7 pin tube socket savers for my LD Mk3 so I could use C3G to 6AK5 adapters.  I finally found these:
  
 http://www.ebay.com/itm/1PC-7pin-tube-test-saver-for-6AK5-EC90-EC92-6C4-6J1-6AU6-6X4-EL95-/201381958186?hash=item2ee34cd22a
  
 They look homemade but do work OK.  The pin holes are very tight.


----------



## hypnos1

trancedoc said:


> I had a hard time finding 7 pin tube socket savers for my LD Mk3 so I could use C3G to 6AK5 adapters.  I finally found these:
> 
> http://www.ebay.com/itm/1PC-7pin-tube-test-saver-for-6AK5-EC90-EC92-6C4-6J1-6AU6-6X4-EL95-/201381958186?hash=item2ee34cd22a
> 
> They look homemade but do work OK.  The pin holes are very tight.


 
  
 Hi Trancedoc.
  
 Speaking of tight pin holes, I do hope you bought the C3g adapters that use the silver plated 'roll-jaw' type receptors in the socket, as opposed to the split round ones used in cheaper ones. As you are probably already aware, you must be EXTRA careful when inserting/removing these tubes - their glass bases crack very easily if stressed. Hence you must NEVER 'roll' the tube with a side-to-side movement...always STRAIGHT in or out. Plus making sure the tube stays even all around the base as you do so. The roll-jaw type is far superior, both for safety and pin contact.
  
 You will, I am sure, be very impressed with what these tubes deliver...
  
 ENJOY!...but be careful out there!!
  
 Cheers.


----------



## NiMo7

Hi guys, I just got my lorenz C3G from the mail and i noticed that one of them has gold pins and other don't. When I touch the black pins my fingers become a little black too. Is there something wrong with it?
 I can't hear them right now because I'm still waiting for the adapters to arrive.
 Sorry for the bad english and thanks.


----------



## hypnos1

nimo7 said:


> Hi guys, I just got my lorenz C3G from the mail and i noticed that one of them has gold pins and other don't. When I touch the black pins my fingers become a little black too. Is there something wrong with it?
> I can't hear them right now because I'm still waiting for the adapters to arrive.
> Sorry for the bad english and thanks.


 
  
 Hi NiMo7...have never seen any that bad before myself...if you got them from omesa-electronic I would get back to him STRAIGHT AWAY - he has just one left (of this batch).
  
 No way should the gold-pin version look like that...
  
 Cheers,
  
 CJ


----------



## NiMo7

hypnos1 said:


> Hi NiMo7...have never seen any that bad before myself...if you got them from omesa-electronic I would get back to him STRAIGHT AWAY - he has just one left (of this batch).
> 
> No way should the gold-pin version look like that...
> 
> ...


 
 There is not a chance It was made like that and I just got two diffrent tubes?
 And if It does'nt, there are ways to clean it? Maybe with alcohol or even with a knife? (very carefully of course).


----------



## gibosi

nimo7 said:


> There is not a chance It was made like that and I just got two diffrent tubes?
> And if It does'nt, there are ways to clean it? Maybe with alcohol or even with a knife? (very carefully of course).


 
  
 It certainly does appear that you got two different tubes, one with gold pins and the other without. 
  
 However, it is also very likely that they will sound the same. So yes, I suggest you clean the pins. First, mechanically clean the standard pins (not the gold pins!) with a dull knife or sandpaper. And I usually follow that up by using a chemical cleaner. Personally, I have found the purple DeoxIT product works very well on both gold and standard pins.


----------



## Shaffer

...deleted...wrong thread.


----------



## hypnos1

nimo7 said:


> There is not a chance It was made like that and I just got two diffrent tubes?
> And if It does'nt, there are ways to clean it? Maybe with alcohol or even with a knife? (very carefully of course).


 
  
 Hi again.
  
 As gibosi says, a thorough clean (of the black pins) should still have the tube working...but did you buy them NOS from the ebayer I mentioned, or were they used tubes? If used, understandable...but if supposed to be gold-pin for both, not...


----------



## NiMo7

gibosi said:


> It certainly does appear that you got two different tubes, one with gold pins and the other without.
> 
> However, it is also very likely that they will sound the same. So yes, I suggest you clean the pins. First, mechanically clean the standard pins (not the gold pins!) with a dull knife or sandpaper. And I usually follow that up by using a chemical cleaner. Personally, I have found the purple DeoxIT product works very well on both gold and standard pins.


 
 Thanks, I will try it when I have time. Should the end result be the pins become silver?
  


hypnos1 said:


> Hi again.
> 
> As gibosi says, a thorough clean (of the black pins) should still have the tube working...but did you buy them NOS from the ebayer I mentioned, or were they used tubes? If used, understandable...but if supposed to be gold-pin for both, not...


 
 Yes, I bought them from omesa-electronic. Should I contact them? As an international buyer It will take me about 2 weeks to send It back and another 2 weeks to get a new one...


----------



## gibosi

nimo7 said:


> Thanks, I will try it when I have time. Should the end result be the pins become silver?


 
  
 They are going to look like the pins on an all-glass miniature tube, like a 6AK5 or 12AU7, Not a shiny silver, but more of a dull metallic sheen.


----------



## NiMo7

So I've used a sandpaper and it looks better:

  
 Unfortunately as I said earlier I'm still waiting for the adapers to arrive so I can't see If the tube works and If I hear a diffrence between the two.
 Although even If everything will turn out good I'm still quite disappointed about the whole thing..


----------



## mordy

Hi NiMo7,
  
 Recently I bought two used tubes from a German seller. They were advertised as C3gS tubes, and the picture showed two tubes - only one had the pins visible - gold pins.
  
 When the tubes arrived I realized that they were two different tubes, one with gold pins, and one regular silvery pins. In addition, they were not C3gS - just regular C3g.
  
 I emailed seller, who said that they were compatible with C3gS, which obviously is misleading and not the same as the specially selected C3gS tubes.
  
Silver lining: Both tubes sound good and sound the same. When they are stuck into their sockets I cannot see the color of the pins, so I pretend they are the same. Since I have a pair of C3gS tubes I know that they sound pretty much the same - don't feel I am missing anything.
  
 Unethical and misleading seller - yes, but not worth fighting about in this case since the tubes sound fine. And with a 10,000 hour life span I am not worried about them being used either.
  

 *?*

 
  
Details about  C3g – 1 Paar Siemens Röhren-Tube-Valve gebraucht gut /used good (=C3gS)  





  
 Caveat Emptor - Buyer Beware
  
 The seller had very good feedback - didn't want to send anything negative back so I just didn't give feedback.
  
 I am sure that once you get your adapters everything will sound splendid - IMHO I don't think you should worry about it.


----------



## NiMo7

mordy said:


>


 
  
 Thanks for the reply , I will wait for the adapters to arrive and then I'll contact the seller If there's something wrong.


----------



## bobbyblack

hypnos1 said:


> Hi Trancedoc.
> 
> Speaking of tight pin holes, I do hope you bought the C3g adapters that use the silver plated 'roll-jaw' type receptors in the socket, as opposed to the split round ones used in cheaper ones. As you are probably already aware, you must be EXTRA careful when inserting/removing these tubes - their glass bases crack very easily if stressed. Hence you must NEVER 'roll' the tube with a side-to-side movement...always STRAIGHT in or out. Plus making sure the tube stays even all around the base as you do so. The roll-jaw type is far superior, both for safety and pin contact.
> 
> ...



Hi Hypnos,me to I decided to upgrade to the C3g after some months with 6n6p-ir/ei-6hm5, allready bought some adapters for 5687 and 2 pairs Tung Sol and Sylvania 5687,and after that gonna be 6sn7-i try to enjoy the road lol,very short comparative with your work guyz on the Little Dot but im enjoying this!
Can you provide a link with the ''good''adapters for C3g?


----------



## Trancedoc

These are the ones that I bought.  They seem to have the "roll jaw" pin holders that bobbyblack described:
  
 http://www.ebay.com/itm/2piece-Gold-plated-C3G-TO-6AK5-tube-converter-adapter-/191424601510?hash=item2c91cb9da6
  
 I pushed half the point of a needle nose pliers into the pin holes first and the C3Gs went in easy.


----------



## hypnos1

bobbyblack said:


> Hi Hypnos,me to I decided to upgrade to the C3g after some months with 6n6p-ir/ei-6hm5, allready bought some adapters for 5687 and 2 pairs Tung Sol and Sylvania 5687,and after that gonna be 6sn7-i try to enjoy the road lol,very short comparative with your work guyz on the Little Dot but im enjoying this!
> Can you provide a link with the ''good''adapters for C3g?


 
  
 Hi b....good choice!
  
 Here's the link  :  http://www.ebay.com/itm/2pc-C3G-TO-6AK5-5654-6096-adapter-for-little-dot-MKIII-SE-Headphone-/201366974329?hash=item2ee2682f79
  
 If you have the MKIII with the rings, you will probably need the tube 'extenders', unless you remove them as some have done (not easy!). Mind you, the pins on these adapters look quite long and _might_ just make contact without the need for them (I'm sure someone found this, but can't be certain...).
  
 ENJOY!


----------



## bobbyblack

Thanks Hypnos you are very helpful like always,i know the need for the extenders i dont even think to remove the rings!
I have read all the Elise thread maybe i'm gonna be the next 00.. who knows.. right in time for the best choices of tubes for him!


----------



## hypnos1

bobbyblack said:


> Thanks Hypnos you are very helpful like always,i know the need for the extenders i dont even think to remove the rings!
> I have read all the Elise thread maybe i'm gonna be the next 00.. who knows..
> 
> 
> ...


 
  
 My pleasure, b...and congrats on ploughing through the Elise thread - never thought it would take off quite as much as that!
  
 And of course I'm gonna have to tell you to start saving and join the other LD guys who are discovering Elise's charms, lol!!


----------



## rovopio

To everybody here!! (you know who you are), THANK YOU, THANK YOU for the 6hm5 tip. It's really great when pair with the _brightest _Grado, the 325e 
 Maybe I should invest on that Muses02 after all.... hmm.


----------



## JazzVinyl

rovopio said:


> To everybody here!! (you know who you are), THANK YOU, THANK YOU for the 6hm5 tip. It's really great when pair with the _brightest _Grado, the 325e
> Maybe I should invest on that Muses02 after all.... hmm.


 
  
 Hello rovopio...
  
 Glad you discovered the 6MH5 option for the LD amps.
  
 The 6HM5's and standard power tubes provide a rich full sound for my LD MK IV, I like it better than some other combinations I have tried. 
  
 Not as "3D" as some other options, but the rich deep bass response is worth the reduction in sound stage, in my opinion.
  
 Cheers!!


----------



## UntilThen

rovopio said:


> To everybody here!! (you know who you are), THANK YOU, THANK YOU for the 6hm5 tip. It's really great when pair with the _brightest _Grado, the 325e
> Maybe I should invest on that Muses02 after all.... hmm.


 
  Hey rovopio, you're here.  How's it going. How are you liking your tube amp?​


----------



## rovopio

untilthen said:


> Hey rovopio, you're here.  How's it going. How are you liking your tube amp?​


 

 Great. I use them a lot and very happy with it. I followed advices from many very kind long-standing members here on tube and op-amp purchase (that is still relatively cheap). I got a opa2107 and a 6hm5. There was some mild snafu regarding the opa2107 delivery (got sent to the wrong continent), so in the end even though I ended up receiving them, I don't use them at all. But I'm happy enough with the stock opamp. So much so that I'm seriously considering getting a MUSES02 op-amp. I'm still considering the price though because it feels _really weird _for me to have to pay the local price of ~$80 for an opamp when the LD i+ itself only cost $110


----------



## UntilThen

It's all good. LD and hd650 pairing is a lovely combination.


----------



## rovopio

untilthen said:


> It's all good. LD and hd650 pairing is a lovely combination.


 
  
 That DarkVoice of yours looks real nice too!


----------



## UntilThen

Darkvoice is nice and cheap. Problem with tube amp love is you'll be itching for more soon. I'm getting Elise end of the month.


----------



## JazzVinyl

Anyone have a single C3gS they could part with?  I have one working example for my LD MK IV, need one more, to make a pair...
  
 Please PM if you have one you can sell.
  
 Appreciate...
  
 --JV--


----------



## WilliamLeonhart

Got a recommendation from rovopio to buy the 6hm5 yesterday. I'm thinking about 'em a lot. Right now I'm having the JAN 5654W, Mullards CV4010, Voshods 6N1P and Siemens 6ak5, all of which are great tubes (and cost me about 70% the cost of the I+ that I have). So I'd like your opinion, would the 6hm5 be a bit redundant in my lineup?
  
 By the way if the tubes are not matched, will the sound be imbalanced? I remember reading somewhere that since the I+ are hybrid, they will not suffer from channel imbalance with tubes.


----------



## Shaffer

Depends on your personal sense of curiosity. A pair of 6HM5 costs less than a pizza. They don't have to be matched.


----------



## MIKELAP

williamleonhart said:


> Got a recommendation from rovopio to buy the 6hm5 yesterday. I'm thinking about 'em a lot. Right now I'm having the JAN 5654W, Mullards CV4010, Voshods 6N1P and Siemens 6ak5, all of which are great tubes (and cost me about 70% the cost of the I+ that I have). So I'd like your opinion, would the 6hm5 be a bit redundant in my lineup?
> 
> By the way if the tubes are not matched, will the sound be imbalanced? I remember reading somewhere that since the I+ are hybrid, they will not suffer from channel imbalance with tubes.


 

 Tubes dont need to be match same brand and type should be sufficient i own the MK3


----------



## NiMo7

nimo7 said:


> Thanks for the reply , I will wait for the adapters to arrive and then I'll contact the seller If there's something wrong.


 
 So I finaly got the adapters, after they were siting at the post office for more than a week without them telling me to pick it up..
 But fortunately the tubes works  And I can't hear a difference between the one with gold pins and one with silver pins.
 I still need to let them burn in but they already sound great .
  
 By the way, there is a reason to remove the metal shields other for the looks? Maybe to let the tubes run less hot?


----------



## Amatak

Hi guys,
  
 Recent Little Dot MKIV SE purchaser here. I've already gotten tube rolling fever and am currently rocking a pair of 6ZH1P-EV and a pair of M8100. Love them both!
 However, I noticed that one of tubes always burns a little brighter than the other. Is this normal? Can't hear any channel imbalances.
  
 Cheers!


----------



## Rossliew

No issues with differences in brightness so long as the music continues to flow uninterrupted


----------



## WilliamLeonhart

shaffer said:


> Depends on your personal sense of curiosity. A pair of 6HM5 costs less than a pizza. They don't have to be matched.


 
  


mikelap said:


> Tubes dont need to be match same brand and type should be sufficient i own the MK3


 
 Thanks for your input. Yep the 6HM5 is really cheap but I'm in Vietnam right now so shipping is another level of difficulty..


----------



## JamesBr

untilthen said:


> It's all good. LD and hd650 pairing is a lovely combination.


 
 HD what ever is a good combination if you ask me


----------



## bobbyblack

Hi guyz,my c3g's arrived from Germany but need adapters for them and I want to ask experts from here or Elise,lol,if 8mm pins adapters are long enough to use the adapter without socket extenders(I asked the guy from China the dimension).
Thanks in advance!


----------



## MIKELAP

bobbyblack said:


> Hi guyz,my c3g's arrived from Germany but need adapters for them and I want to ask experts from here or Elise,lol,if 8mm pins adapters are long enough to use the adapter without socket extenders(I asked the guy from China the dimension).
> Thanks in advance!


 

 You would need extenders 8mm(5/16¨) rings are 5mm thick you would be left with less than 1/8¨ ( .115 ¨) not enough.


----------



## gibosi

Or find a way to remove the rings....


----------



## MIKELAP

gibosi said:


> Or find a way to remove the rings....


 

 Personnally that's what i did i cut them off very carefully with my Dremel and a cutting wheel  .These rings are held in place with 2 small screws at 3 and 9 o'clock .Just make shure to recuperate the screws because they will fall in the amp just unscrew front panel being careful not to break off pot wires they are very fragile and like on the picture dont cut right thru leave some material and pry them with a small screw driver at that point they will bend easily


----------



## NiMo7

I removed the Rings on my I+, it's not that hard took me about 15 minutes or so.
It's look better that way in my opinion, with the adapters it looks a little weird and too tall.


----------



## bobbyblack

Thanks Mike and Gibosi,Nimo yes u are right with socket savers look a little weird and tall, not elegant at all(but sound is GLORIOUS as someone said )!Hmm I think I am gonna try remove the rings-i remember Hypnos posted some photos with his LD mk4 with those goldish protectors removed and looked good.
Mike you removed the power rings to?,maybe some photos how it looks now,if you have time,it would be nice!
Thanks again!


----------



## MIKELAP

bobbyblack said:


> Thanks Mike and Gibosi,Nimo yes u are right with socket savers look a little weird and tall, not elegant at all(but sound is GLORIOUS as someone said )!Hmm I think I am gonna try remove the rings-i remember Hypnos posted some photos with his LD mk4 with those goldish protectors removed and looked good.
> Mike you removed the power rings to?,maybe some photos how it looks now,if you have time,it would be nice!
> Thanks again!


 
   And if you ever want to put rings back on they have different sizes available on Ebay


----------



## bobbyblack

Thank you, nice, after I remove the rings and run the C3g's with 6n6p-ir and 5687 as power i'm gonna post some photos and impressions about this combos!


----------



## i luvmusic 2

I was bored last night so i end up removing the metal shield of  my 3 sets of C3g's(2 sets-Siemens 1 set Lorenz)They look much better naked


----------



## mordy

Hi il2,
  
 Are the Siemens and Lorenz tubes identical - i.e., are the Lorenz re-branded Siemens tubes?


----------



## WilliamLeonhart

nimo7 said:


> I removed the Rings on my I+, it's not that hard took me about 15 minutes or so.
> It's look better that way in my opinion, with the adapters it looks a little weird and too tall.


 
 It looks IMPRESSIVE! My I+ now looks too boring to me


----------



## NiMo7

i luvmusic 2 said:


> I was bored last night so i end up removing the metal shield of  my 3 sets of C3g's(2 sets-Siemens 1 set Lorenz)They look much better naked




What's the pros and cons of removing the metal shields? (other from the looks). 
Maybe they run cooler without it? 





williamleonhart said:


> It looks IMPRESSIVE! My I+ now looks too boring to me


----------



## WilliamLeonhart

I do think we should have a post to sum up all the reviews on the tubes that we've tried. The 1st post is quite detailed already but somewhere in between someone'd post their review of _a list of tubes. _It's really a waste to let those post lost on page 781 or something.


----------



## MIKELAP

This list might help some of you new to the thread   and is by no means complete.


----------



## i luvmusic 2

mordy said:


> Hi il2,
> 
> Are the Siemens and Lorenz tubes identical - i.e., are the Lorenz re-branded Siemens tubes?


 
 They look like two different constructions to me.
  
 LORENZ(no 3 washers under the base)

  

  

  
 SIEMENS (with 3 washers under the base)


----------



## i luvmusic 2

nimo7 said:


> What's the pros and cons of removing the metal shields? (other from the looks).
> Maybe they run cooler without it?
> 
> 
> ...


 
 Just for looks.


----------



## boombastic

photo of my much loved mkIV se.


----------



## WilliamLeonhart

mikelap said:


> This list might help some of you new to the thread   and is by no means complete.


 
 Thanks Mike! 


boombastic said:


> photo of my much loved mkIV se.


 
 One of the most beautiful pics on LD I've ever seen!


----------



## rovopio

nimo7 said:


> I removed the Rings on my I+, it's not that hard took me about 15 minutes or so.
> It's look better that way in my opinion, with the adapters it looks a little weird and too tall.


 
 Hi NiMo7, can I ask you in general how do you remove the ring on your LD I+? and what sort of tools would I need to remove them?


----------



## boombastic

Thank you Lehoang!


----------



## NiMo7

rovopio said:


> Hi NiMo7, can I ask you in general how do you remove the ring on your LD I+? and what sort of tools would I need to remove them?


 
 It's pretty simple, I learned how to do it while doing it.. You will only need phillips screwdriver.
 Each ring is held by two screws underneath it. To reach those screws you need to remove the board by unscrewing all the screws that holding it to the top cover. After you remove the rings just screw back the board and you are done.
 Do all of this with attention not to tear the wires that connect the board the front and back of the amplifier.
  
 Hope you could understand from my bad english..


----------



## mordy

Hi il2,
  
 Thanks for the nice pictures - it really looks like they are two different productions. The next question is if the Telefunken and Valvo C3g tubes also are different.


----------



## f950506

Hey all,
  
 First of all, thank you all for putting so much effort into this thread while being so noob-friendly at the same time. The amount of information is overwhelming, as I'm only 50 pages in. However, it does seem like the consensus is that 6MH5>M8100=M8161=6ZH1P-EV are the more wallet-friendly options for the MK III which I own. I don't plan on rolling too many tubes, but these are definitely the ones that are worth a try, right? Is there a preferred brand for the 6MH5's? Lastly, what are the best power tubes, price-performance-wise, for the MK III?
  
 Best regards,
 Wayne


----------



## bobbyblack

f950506 said:


> Hey all,
> 
> First of all, thank you all for putting so much effort into this thread while being so noob-friendly at the same time. The amount of information is overwhelming, as I'm only 50 pages in. However, it does seem like the consensus is that 6MH5>M8100=M8161=6ZH1P-EV are the more wallet-friendly options for the MK III which I own. I don't plan on rolling too many tubes, but these are definitely the ones that are worth a try, right? Is there a preferred brand for the 6MH5's? Lastly, what are the best power tubes, price-performance-wise, for the MK III?
> 
> ...


Yugoslavian EI-6hm5 tall bottle are considered best driver tubes and 6N6P-IR for power.There are better options but use adapters,socket savers,PS,etc.


----------



## mordy

Hi f95xxx,
  
 Any 6SN7 power tube is better than the 6H30 family in the MKIII. Shop for a cheap pair of Sylvania and get the adapters - you will not regret it!


----------



## Shaffer

FWIW, I have a pair for sale of almost new 6N6P-IR, if anyone is interested.


----------



## f950506

These are the adapters that I should use, right? But why is it from 6cg7 to 6sn7? I thought the mk3 uses 6ak5. 
 http://www.ebay.com/itm/221065459067?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT&rmvSB=true
 And what will be a good price for sylvania 6sn7's? Does gta/gtb matter? They seem a bit pricey on eBay. From what I read, I assume it is okay to use unmatched power tubes, and all the 6sn7's work pretty well. 
  
 Man, I feel like I'm putting together a puzzle, except I don't even know what the pieces look like yet. I have the mk3 on the way, voskhod's on the way, rtc 5654rt's on the way (hopefully they are actually re-branded m8100s), 6hm5's on the way, and most importantly, the new headphones on the way. Now to add to the list, the adapters and power tubes. I can't wait to get this over with, this is too intense...


----------



## gibosi

f950506 said:


> These are the adapters that I should use, right?
> http://www.ebay.com/itm/221065459067?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT&rmvSB=true
> And what will be a good price for sylvania 6sn7's?


 
  
 If you are hoping to use 6SN7 as power tubes, then yes, those adapters will work fine.
  
 A nice pair of Sylvania 6SN7GT or 6SN7GTA (I would not encourage you to get 6SN7GTB) can often be purchased for around $50. For example:
  
 http://www.ebay.com/itm/6SN7GTA-vacuum-tubes-2-valve-Sylvania-chromed-top-radio-amplifier-tested-6SN7GT-/231683734199


----------



## mordy

Hi f95xxx,
  
 The bigger tubes in the back of the amp are power tubes (the ones in the front driver tubes). The back ones use sockets with 9 pins, the front ones with 7 pins.
  
 The LD MKIII uses 6AK5 type tubes with seven pins as driver tubes, but the 6SN7 should be used for power tubes.
  
 The 6SN7 tubes use a different base with 8 pins called an octal base. The purpose of the adapter is to allow octal 8 pin tubes to work in the 9 pin socket. It is very simple - literally plug and play.
  
 Gibosi is our resident tube expert and you cannot go wrong with any of his recommendations.


----------



## drofeel71

+1 on the recommendations of gibosi. Although he is a danger to your wallet too, my LD +1 has sounded sublime since I invested in the muses02 opamp along with a pair of 6HM5s that he recommended, has taken my listening pleasure to a whole new level, and my AKG K550s have never sounded so sweet.


----------



## f950506

Thanks for the input. It might take a while because of all the international shipping, but I will let you guys know how it goes.


----------



## JamesBr

f950506 said:


> Thanks for the input. It might take a while because of all the international shipping, but I will let you guys know how it goes.


 
 Can't wait!


----------



## WeirdChild

Hi guys! Can someone tell me what are the kind of adapters and extenders that will needed to run the *6SN7GT* *tubes (back sockets) *on a MK IV links will be much appreaciated! Much love!


----------



## MIKELAP

weirdchild said:


> Hi guys! Can someone tell me what are the kind of adapters and extenders that will needed to run the *6SN7GT* *tubes (back sockets) *on a MK IV links will be much appreaciated! Much love!


 
 http://www.ebay.com/itm/1pc-Gold-plated-6SN7-6n8p-CV181-TO-6CG7-6FQ7-tube-converter-adapter-/201115946751?hash=item2ed371ceff                                                                                                                                                                                                                                                                                                                                    http://www.partsconnexion.com/SOCKET-74490.html


----------



## pctazhp

weirdchild said:


> Hi guys! Can someone tell me what are the kind of adapters and extenders that will needed to run the *6SN7GT* *tubes (back sockets) *on a MK IV links will be much appreaciated! Much love!


 
  
 For the MK IV you might want to consider this extender: http://www.ebay.com/itm/Pomona-Electronics-Vectron-Model-1449-9-Pin-Tall-Tube-Socket-Test-Fixture-/151839808329?hash=item235a5b9b49.
  
 It looks funky and is expensive. But it will clear the MK IV's rear tube guards without having to remove them. I use the 7 pin version for the drivers. Of course, you will also need the adapter already suggested to you by MIKELAP.


----------



## f950506

mikelap said:


> http://www.ebay.com/itm/1pc-Gold-plated-6SN7-6n8p-CV181-TO-6CG7-6FQ7-tube-converter-adapter-/201115946751?hash=item2ed371ceff                                                                                                                                                                                                                                                                                                                                    http://www.partsconnexion.com/SOCKET-74490.html


 
 Are the pins on these (http://www.ebay.com/itm/1pc-Gold-plated-6SN7-6n8p-CV181-TO-6CG7-6FQ7-tube-converter-adapter-/201115946751?hash=item2ed371ceff&rmvSB=true) long enough? I tried these (http://www.ebay.com/itm/221065459067?_trksid=p2060353.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT) and they couldn't fit into the mk iii because of the brass ring. 
  
 Wayne


----------



## MIKELAP

f950506 said:


> mikelap said:
> 
> 
> > http://www.ebay.com/itm/1pc-Gold-plated-6SN7-6n8p-CV181-TO-6CG7-6FQ7-tube-converter-adapter-/201115946751?hash=item2ed371ceff                                                                                                                                                                                                                                                                                                                                    http://www.partsconnexion.com/SOCKET-74490.html
> ...


 
 i  bought the second pair of adapter but i removes those steel rings in the back with a Dremel. or buy some 9 pin extenders that you add to the 6cg7 to 6sn7 adapters


----------



## f950506

mikelap said:


> i  bought the second pair of adapter but i removes those steel rings in the back with a Dremel. or buy some 9 pin extenders that you add to the 6cg7 to 6sn7 adapters


 
 Wow, that is pretty brutal. Nice work. Unfortunately I don't have the tools to do this, and I can't seem to find the extenders on eBay :/


----------



## MIKELAP

I got them at Parts Connexions.in Canada.


----------



## f950506

I found the extenders. As it turned out, they are called socket savers on eBay. I guess that's the correct name for it technically.


----------



## WeirdChild

mikelap said:


> http://www.ebay.com/itm/1pc-Gold-plated-6SN7-6n8p-CV181-TO-6CG7-6FQ7-tube-converter-adapter-/201115946751?hash=item2ed371ceff                                                                                                                                                                                                                                                                                                                                    http://www.partsconnexion.com/SOCKET-74490.html


 
 I ordered a pair of this http://www.ebay.com/itm/251979290919 because of the quality plus Priority Mail shipping option. Would that work? I know those adapters work for the * 6080 / 6AS7G **with **the UPS workaround (in case I want to go that route). Have not bought the tubes yet, still deciding, thanks for your input.*


----------



## MIKELAP

weirdchild said:


> mikelap said:
> 
> 
> > http://www.ebay.com/itm/1pc-Gold-plated-6SN7-6n8p-CV181-TO-6CG7-6FQ7-tube-converter-adapter-/201115946751?hash=item2ed371ceff                                                                                                                                                                                                                                                                                                                                    http://www.partsconnexion.com/SOCKET-74490.html
> ...


 
 I pointed out to you the other adapters  because those cmc type sockets are good quality those are the types of sockets Woo Audio uses in there amps  .Also the lead solder from the pins that protrudes from under your  sockets i dont like that i prefer when everything is enclosed its safer imo.


----------



## i luvmusic 2

I don't think if you can used that adapter it is a fire hazard those exposed terminals could come in contact with the chassis and you will see the magic smoke.
 It's a high quality materials but it is very poorly assembled.I have seen some nice looking DIY adapters that was posted in this thread way better than the one in the picture.

 Like this one.

 Just kidding


----------



## MIKELAP

i luvmusic 2 said:


> I don't think if you can used that adapter it is a fire hazard those exposed terminals could come in contact with the chassis and you will see the magic smoke.


 
 Definitely wouldnt try those i would rather wait a month and order from China or maybe some seller has safer adapters made in U.S.A.


----------



## i luvmusic 2

mikelap said:


> i luvmusic 2 said:
> 
> 
> > I don't think if you can used that adapter it is a fire hazard those exposed terminals could come in contact with the chassis and you will see the magic smoke.
> ...


 
 Or you could make him one


----------



## MIKELAP

i luvmusic 2 said:


> I don't think if you can used that adapter it is a fire hazard those exposed terminals could come in contact with the chassis and you will see the magic smoke.
> It's a high quality materials but it is very poorly assembled.I have seen some nice looking DIY adapters that was posted in this thread way better than the one in the picture.
> 
> Like this one.
> ...


 
 I guess thats where the inspiration came from when we received a jolt we didnt feel a thing lol lol


----------



## WeirdChild

Shame, I paid for the adapters already  , I emailed the seller and asked if he could cover the terminals... somehow.. Anyway, I decided to go for the *6SN7GTA SYLVANIA * also got a pair of Siemens C3G-S with adapters I purchased on the head-fi trade forum.


----------



## i luvmusic 2

mikelap said:


> >
> 
> 
> 
> I guess thats where the inspiration came from when we received a jolt we didnt feel a thing lol lol


 
  
 LOL


weirdchild said:


> Shame, I paid for the adapters already  , I emailed the seller and asked if he could cover the terminals... somehow.. Anyway, I decided to go for the *6SN7GTA SYLVANIA * also got a pair of Siemens C3G-S with adapters I purchased on the head-fi trade forum.


 
 I hope your vendor will do something about it(You should mention to the vendor that that product is unsafe),GOOD LUCK!


----------



## i luvmusic 2

I look at the link for that adapter and just found out that the socket is just a regular gold plated cup style socket PCB mount not one of those premium ceramic socket.
  
 Premium Ceramic socket/PCB that i used for my AMPS.


----------



## MIKELAP

weirdchild said:


> Shame, I paid for the adapters already  , I emailed the seller and asked if he could cover the terminals... somehow.. Anyway, I decided to go for the *6SN7GTA SYLVANIA * also got a pair of Siemens C3G-S with adapters I purchased on the head-fi trade forum.


 
 Ask for a refund the worst that could happen is if he says no


----------



## WeirdChild

Solved the problem, seller was very friendly and replied quickly and he offered to do some modifications to avoid the problems you mentioned, also offered to send some socket savers too, all for no extra cost.

 He sells the adapters for the amps his company makes. Thanks to all of you guys, will post soon after I install all these thingies.


----------



## gulakpi

Hi!  I have a LD1+ and I'm interested to get a pair of C3m (much cheaper than the C3g).
 I understand the pin-out of the C3m is different from the C3g, so I have to build the adapters myself (and use the 20V heater voltage in the LD1+.)
 I found the Loctal sockets are rather difficult to get locally.   Is it possible if I use a Octal socket instead, provided once I carefully insert the C3m, I will not remove it?


----------



## MIKELAP

gulakpi said:


> Hi!  I have a LD1+ and I'm interested to get a pair of C3m (much cheaper than the C3g).
> I understand the pin-out of the C3m is different from the C3g, so I have to build the adapters myself (and use the 20V heater voltage in the LD1+.)
> I found the Loctal sockets are rather difficult to get locally.   Is it possible if I use a Octal socket instead, provided once I carefully insert the C3m, I will not remove it?


 
 You can get a good quality Loctal socket here  cannot use octal socket pins are alot bigger in octal socket                                                                              http://www.ebay.com/itm/191571487234?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT    or here            http://www.ebay.com/itm/381087439551?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT        i have an mk3 and i couldnt use a C3M Loctal with my amp with only adapters check out  the thread or maybe someone who has a LD1+ can help but not shure you can use C3M Loctals


----------



## gulakpi

Thank you Mikelap,
 I have purchased the parts and will experiment with them once they arrive.
  
 Another question:  On the Ld Mk4 (as well as the Mk2 & Mk3), are there 2 separate heater windings, each capable of 500mA max, supplying the driver tubes?  Or if there is a 6.3V/1A total winding for both driver tubes/
 Is that the reason we cannot use the internal heater circuit to supply a single 5687 or 6SN7 at >500mA, even we will be using one tube instead of 2 for the driver stage?


----------



## gibosi

First, you should know that we do not have an official schematic for any LD amp. Second, I am not an electrical engineer or journeyman electrician. In fact, I figure I know just enough to be dangerous. lol. And third, we always try to be safe rather than sorry in our recommendations. That said, it is my understanding that while it appears that there is a single 6.3V/1A winding to supply both driver sockets, a number of our more knowledgeable members harbor some doubt that the connecting wires from the transformer to each socket were designed to handle more than 0.5 amps, much less 1 amp. And therefore, we always advise folks to assume that is not safe to draw more than about 0.45 amps in either of the driver sockets. Thus our recommendation for the use of an external heater supply when running tubes drawing in excess of 0.45 amps.


----------



## gulakpi

gibosi said:


> First, you should know that we do not have an official schematic for any LD amp. Second, I am not an electrical engineer or journeyman electrician. In fact, I figure I know just enough to be dangerous. lol. And third, we always try to be safe rather than sorry in our recommendations. That said, it is my understanding that while it appears that there is a single 6.3V/1A winding to supply both driver sockets, a number of our more knowledgeable members harbor some doubt that the connecting wires from the transformer to each socket were designed to handle more than 0.5 amps, much less 1 amp. And therefore, we always advise folks to assume that is not safe to draw more than about 0.45 amps in either of the driver sockets. Thus our recommendation for the use of an external heater supply when running tubes drawing in excess of 0.45 amps.


 

 Many thanks Gibosi,  Well understood!
 It's always better be safe than sorry!
 I raised the question because I read a photo posted by TD in the early pages, that the LD transformer has a 3.3V*2/1A winding, and assumed that was the case.  Thank you for the caution!


----------



## i luvmusic 2

IMO it is always safe to use a EXTERNAL POWER SUPPLY no matter what type of tubes we used for this wonderful amp(except for those plug and play)at least for me anyway.


----------



## WeirdChild

Got the adapters I mentioned before with the safety mod so the terminals wont touch the case, but the 6s7n tubes just wont fire up. think I am screwed lol. The C3gs are just awesome tho!


----------



## hypnos1

weirdchild said:


> Got the adapters I mentioned before with the safety mod so the terminals wont touch the case, but the 6s7n tubes just wont fire up. think I am screwed lol. The C3gs are just awesome tho!


 
  
 Hi WeirdChild...afraid I haven't been around for a good while - my MKIV SE was ousted by my Feliks-Audio Elise, I'm afraid!
  
 But am really glad the C3g is still finding fans who appreciate its magic, lol!...
  
  
 Cheers,
 CJ


----------



## WeirdChild

hypnos1 said:


> Hi WeirdChild...afraid I haven't been around for a good while - my MKIV SE was ousted by my Feliks-Audio Elise, I'm afraid!
> 
> But am really glad the C3g is still finding fans who appreciate its magic, lol!...
> 
> ...


 
 Hi hypnos1, glad you are enjoying that great Amp, have read a lot about it! Unfortunately I havent been able to run the C3Gs with a decent pair of powertubes, the adapters I ordered didnt work, my big shame, well, as I am expecting a shipment from china that carries the adapters Mike sugested, along with some 9 pin socket savers. I have been reading this thread a lot and now I wonder if you could assist me in running some Tung-Sol 6080 (already got them), As I could see you ran this project before! Well the thing is that I made a diagram and just want to make sure everything is in order, will be a very fun weekend project anytime soon.  Please check the image and tell me what would you suggest in case something is missing, Help will be very much appreciated cheers!


----------



## gibosi

weirdchild said:


> ......As I could see you ran this project before! Well the thing is that I made a diagram and just want to make sure everything is in order, will be a very fun weekend project anytime soon.  Please check the image and tell me what would you suggest in case something is missing, Help will be very much appreciated cheers!


 
  
 Your diagram looks pretty good to me. However, I do not see one important step. You must cut off pins 4 and 5 on the two 9-pin socket savers. Since you are supplying power to the heaters externally, you need to sever the connection to the LD's heater circuit. I suspect you already know this, but since I do not see it on your diagram, I wanted to be sure.


----------



## WeirdChild

gibosi said:


> Your diagram looks pretty good to me. However, I do not see one important step. You must cut off pins 4 and 5 on the two 9-pin socket savers. Since you are supplying power to the heaters externally, you need to sever the connection to the LD's heater circuit. I suspect you already know this, but since I do not see it on your diagram, I wanted to be sure.


 
 You are right, forgot to mention pins 4 and 5 from the socket saver must be cut off or desoldered and must not be conected to the LD.  Thanks for all the help! Will report soon.


----------



## gibosi

weirdchild said:


> You are right, forgot to mention pins 4 and 5 from the socket saver must be cut off or desoldered and must not be conected to the LD.  Thanks for all the help! Will report soon.


 
  
 Mordy, Hypnos1 and others have blazed a very clear trail for you and I am sure you will be astounded and delighted with the results. Cheers!


----------



## hypnos1

weirdchild said:


> Hi hypnos1, glad you are enjoying that great Amp, have read a lot about it! Unfortunately I havent been able to run the C3Gs with a decent pair of powertubes, the adapters I ordered didnt work, my big shame, well, as I am expecting a shipment from china that carries the adapters Mike sugested, along with some 9 pin socket savers. I have been reading this thread a lot and now I wonder if you could assist me in running some Tung-Sol 6080 (already got them), As I could see you ran this project before! Well the thing is that I made a diagram and just want to make sure everything is in order, will be a very fun weekend project anytime soon.  Please check the image and tell me what would you suggest in case something is missing, Help will be very much appreciated cheers!


 
  
 Hi WeirdChild...very impressive! And glad you already know about gibosi's mention re disconnecting from the LD's heater supply.
  
 I hope you have no problems with hum from the external PS - if you do get any at all, try connecting the DC neg. out to a mains Earth point.
  
 And I wish you all the best with your project - you will be amazed at the difference! But I'm so sorry about your C3gs....I do hope the new adapters work OK - these tubes will also take your amp to whole new levels...CHEERS!


----------



## WeirdChild

gibosi said:


> Mordy, Hypnos1 and others have blazed a very clear trail for you and I am sure you will be astounded and delighted with the results. Cheers!


 
 Thank you guys for going down the road and coming back with buckets of knowledge for others to learn. It is a sweet ride. I appreciate it.


----------



## i luvmusic 2

You can open the 9 pin socket saver and de-solder the pins instead of cutting it.


----------



## hypnos1

weirdchild said:


> Thank you guys for going down the road and coming back with buckets of knowledge for others to learn. It is a sweet ride. I appreciate it.


 
  
 Hi WeirdC.
  
 That ride was sometimes a real 'hairy' one, lol! A whole bunch of great guys did some unbelievable (crazy, actually! 
	

	
	
		
		

		
		
	


	




) things that went in all kinds of directions...but which achieved amazing results without having to do major surgery _inside_ the LDs - and which has come in very handy since!
  
 Good luck once again in your own efforts...
  
 ps.  Are your C3gs still in the canisters? If so, you presumably wouldn't know if the heaters at least were working? Did you have to 'work' the tubes hard into the adapters' sockets?...some of us lost tubes because of this (as you probably read) - the base of the tube's glass is so fragile, any undue stress on the pins (especially from a side-to-side 'rocking/rolling' motion) can easily crack the glass. If still canistered, it can be difficult to tell if the tube has actually gone or not!  These tubes MUST be inserted/removed ONLY with a straight action, and preferably without having to use too much force.


----------



## WeirdChild

hypnos1 said:


> Hi WeirdC.
> 
> That ride was sometimes a real 'hairy' one, lol! A whole bunch of great guys did some unbelievable (crazy, actually!
> 
> ...


 
 Hi! hypnos1 Sorry I did not make myself clear, the adapters that didnt work were for a couple of 6SN7! Problem is I do not have another pair of these tubes to check what is wrong, anyway, I decided to go for the 6080 route and try the new adapters (still waiting for them) The CSGs are working wonderfully and waiting for the 6080s to join the party! Please tell me, what can of an improvement should I wait for, in your own experience?


----------



## hypnos1

weirdchild said:


> Hi! hypnos1 Sorry I did not make myself clear, the adapters that didnt work were for a couple of 6SN7! Problem is I do not have another pair of these tubes to check what is wrong, anyway, I decided to go for the 6080 route and try the new adapters (still waiting for them) The CSGs are working wonderfully and waiting for the 6080s to join the party! Please tell me, what can of an improvement should I wait for, in your own experience?


 
  
 Ah...that's good news then - re. the C3gs at least! 
	

	
	
		
		

		
		
	


	




 But sorry for the 6SN7 problem...However, no big deal, because once you have the 6080s in place (or some nice 6AS7Gs even!) you can forget the 6SN7 lol!... With the C3gs in the driving seat, you are in for a real treat, basically!! There is an overall boost in dynamics and authority, which helps to balance out a bit more the C3g's bass in relation to its treble that can sometimes - depending on gear/ears - be a tad OTT!. The resultant powerful presentation is quite remarkable, especially for such a modestly priced amp - the C3g just cries out for this family of power tubes, and rewards you handsomely... they highlight this driver's amazing qualities such that if you found the C3g wonderful before, you will be searching for even more superlatives when you treat these little wonders to their new partners!...a marriage made in Heaven, basically!!  
	

	
	
		
		

		
		
	


	



  
 So in effect, WC, just imagine all that you love about the C3g... *magnified!!!*...(Already I'm feeling excited _for_ you, lol! 
	

	
	
		
		

		
		
	


	




). CHEERS!


----------



## northendjazz

So I read the thread after buying a mkII and enjoyed working my way up to c3g's.
 They started with problems, I was thinking I spent money for a horrific buzz with the 5687 power tubes I had running so I went back to 6N6P Novosibirsk power tubes. That solved the problem If I gave the amp 30 mins warm up.
 I wanted to try 6sn7 as power tubes and I'm happy I did, all quiet no buzz so I can relax and enjoy the c3g's magic with no warm up needed but given anyway.
  
 I'm now running and enjoying Onkyo CD - Beresford Bushmaster DAC - Little Dot mkII - Siemens C3g - 6SN7GTB Sylvania Chrome dome -  DT880 600's.  With some Sylvania 6SN7WGTA on the way.
  
 One thing I have noticed with this combo is the running temp of the amp has dropped,  any clues as to why this happend?


----------



## Trancedoc

This also happened to my MK 3 also after I upgraded to C3Gs and 6SN7s.  I suspect it is from having the adapters and socket savers lifting the hot tubes above the chassis.


----------



## hypnos1

northendjazz said:


> So I read the thread after buying a mkII and enjoyed working my way up to c3g's.
> They started with problems, I was thinking I spent money for a horrific buzz with the 5687 power tubes I had running so I went back to 6N6P Novosibirsk power tubes. That solved the problem If I gave the amp 30 mins warm up.
> I wanted to try 6sn7 as power tubes and I'm happy I did, all quiet no buzz so I can relax and enjoy the c3g's magic with no warm up needed but given anyway.
> 
> ...


 
  
  


trancedoc said:


> This also happened to my MK 3 also after I upgraded to C3Gs and 6SN7s.  I suspect it is from having the adapters and socket savers lifting the hot tubes above the chassis.


 
  
 Glad to see you guys are also enjoying the magic of the C3g. And that you've also gone for different powers...the things we did with our poor LDs - and they just kept asking for more, lol!...amazing! 
	

	
	
		
		

		
		
	


	



 As mordy has often mentioned, another benefit of socket savers/extenders is that extra cooling effect....which certainly comes in handy with the mighty 6AS7G/6080s!! But even though our amps ended up running _very_ hot, they still didn't seem to object...even more amazing!!!


----------



## Shaffer

trancedoc said:


> This also happened to my MK 3 also after I upgraded to C3Gs and 6SN7s.  I suspect it is from having the adapters and socket savers lifting the hot tubes above the chassis.




6SN7s also draw a lot less juice - ~600mA vs close to 0.9A for the stock tubes.


----------



## gulakpi

I experienced serious distortions at higher volume after switching to 6SN7 as power tubes.  I'm using a pair of AKG K712  62 ohm cans, and that might have been the cause.
  
 If I played at lower volume, the sound from the 6SN7 is silky smooth though!
 I rolled different driver tubes with the 6SN7 to try to find a match. My beloved 6ZH1P was the worst one, followed by the 6HM5, EF900, 6915A and EF94.  To my surprise, the stock 5654W behaves quite nicely.  I can still hear the distortion, but they are almost gone unless I turn on the volume loud.
  
 I do not have a pair of the C3g, and I wonder if this will solve the problem?!!
  
 The temperature on the chassis is barely 1 or 2 degrees above ambient with the 6SN7!  It's amazing!


----------



## northendjazz

Makes sense, so my MkII will not be a room heater this winter. I have yet to try the 6sn7's with anything other than c3g's yet, I'll roll my way through my tube collection again. 
  
 If I have understood the info on page 585  6sn7's "classic high end tube, not compatible with low impedance cans" .
  
 Also Mullard EF95 cv850 (marked on tube) I found them better than the cv4010 I'm new to discribing the SQ of tubes so better will have to do and I only have one Cv850 left as the other failed.


----------



## gibosi

northendjazz said:


> If I have understood the info on page 585  6sn7's "classic high end tube, not compatible with low impedance cans" .


 
  
 Yes! The 6SN7 is not as powerful as the stock tube or a 5687, so it cannot driver low-Z cans well....


----------



## MIKELAP

I just remembered i had 2 pairs of the CV850 was wondering if anybobody has the date codes for these i think there Mullards     the codes are 2E2 R9C1


----------



## MIKELAP

Finally i used the search this thread function was forgetting about that and gibosi you gave me the answer to my question on the 6/16/2013  page 104 post 1547  date was 10 week 1969


----------



## northendjazz

It may be nothing but my cv850 doesn't have round hole in the plate just a small rectangle but the same overall construction, in the failed one you can see the D getter? I'll post pics if needed.


----------



## MIKELAP

northendjazz said:


> It may be nothing but my cv850 doesn't have round hole in the plate just a small rectangle but the same overall construction, in the failed one you can see the D getter? I'll post pics if needed.


 
 Found this about the different  CV850  .if your interested in this tube use the SEARCH FUNCTION atop the page


----------



## gibosi

mikelap said:


> I just remembered i had 2 pairs of the CV850 was wondering if anybobody has the date codes for these i think there Mullards     the codes are 2E2 R9C1


 
  
 The Philips production code tells us that this tube was manufactured in Mullard's Mitcham factory (R). "9C1" suggests the first week in March, 1969. The silk-screened CV code under the upward facing arrow, "6910", tells us the 10th week of 1969. So these correlate rather well.


----------



## Oskari

northendjazz said:


> It may be nothing but my cv850 doesn't have round hole in the plate just a small rectangle but the same overall construction, in the failed one you can see the D getter? I'll post pics if needed.


 
  
 Please post photos if you feel like it. Perhaps we'll all learn something. 
	

	
	
		
		

		
			





 Don't forget to show all the codes!


----------



## Ormia

Has anyone ever tried simulating the sonic effects of tube rolling by designing digital filters (in MATLAB or Labview)?


----------



## WeirdChild

*Built update 1.*

 Everything went nice and easy, was able to wire everything and got the tubes powered.   

 Test setup:
  

  

 Unfortunately one of the tubes died. How? Guess it was because of a blue spark! Tube lights up (as seen in picture) I have swapped adapters, tube and extenders and yes, confirmed, tube is dead, or well, almost. I get a faded out sound from it, and crackles. Any sugestions?

 I have no other similar tube to match the other as of now. Have to order another 6080? Has to be the same brand? Well, ran the 6080 along with the 6SN7 for a quite a while and wow, well, half wow! 

 Back to the 6SN7 + c3gs for now! And also noticed the amp runs cooler, the power supply doesnt even get hot like it used to after some hours. I was scared at first but then i realized everything was okay!


 Thanks!


----------



## i luvmusic 2

^^^
 Nice looking setup you got there.


----------



## WeirdChild

i luvmusic 2 said:


> ^^^
> Nice looking setup you got there.


 
 Cheers!


----------



## Johnnysound

[/quote]

This project is for the LDMKIV, it works the same with the MKIII ?


----------



## gibosi

weirdchild said:


> Unfortunately one of the tubes died. How? Guess it was because of a blue spark! Tube lights up (as seen in picture) I have swapped adapters, tube and extenders and yes, confirmed, tube is dead, or well, almost. I get a faded out sound from it, and crackles. Any sugestions?
> 
> I have no other similar tube to match the other as of now. Have to order another 6080? Has to be the same brand? Well, ran the 6080 along with the 6SN7 for a quite a while and wow, well, half wow!
> 
> Back to the 6SN7 + c3gs for now! And also noticed the amp runs cooler, the power supply doesnt even get hot like it used to after some hours. I was scared at first but then i realized everything was okay!


 
  
 Before completely giving up on that tube, if you haven't already, thoroughly clean the pins with sandpaper or a dull knife.


----------



## gibosi

johnnysound said:


>


 
 This project is for the LDMKIV, it works the same with the MKIII ?[/quote]

  
 Yes.


----------



## Johnnysound

Thanks, G. I am worried about the little red square which is not located above pins 4 & 5. If the extender is seen from above, "hole side", clockwise from 1 to 9.


----------



## gibosi

Seen from above, the "hole side", you count pins counterclockwise, from right to left. Turning the adapter upside down, the "pin side" facing up, you count pins clockwise, from left to right. It is a little confusing, but I think the red squares are positioned correctly.


----------



## WeirdChild

gibosi said:


> Before completely giving up on that tube, if you haven't already, thoroughly clean the pins with sandpaper or a dull knife.


 
 gibosi: Cleaned pins with alcohol. Used the scrap with knife thingy. Cleaned with alcohol again. Plugged in, turned them on. The heaters glow evenly and the temperature is somewhat equal to the other tube but still no sound. Swapped tubes into the sockets and the same.  anyway the replacement I ordered is arriving tomorrow.  I remember it well, first time I powerd them that tube light up blue and I saw a spark. Maybe it shorted? Thanks!


----------



## WeirdChild

johnnysound said:


> Thanks, G. I am worried about the little red square which is not located above pins 4 & 5. If the extender is seen from above, "hole side", clockwise from 1 to 9.


 
  

  

Hope this helps!
  
  
 EDITED IMAGE, CHECK LATEST!


----------



## Johnnysound

Thank you WeirdChild, now it is absolutely clear !!


----------



## Johnnysound

gibosi said:


> Seen from above, the "hole side", you count pins counterclockwise, from right to left. Turning the adapter upside down, the "pin side" facing up, you count pins clockwise, from left to right. It is a little confusing, but I think the red squares are positioned correctly.



Yes they are. And it is indeed a bit confusing, better to be sure before cutting the wrong pin !


----------



## bobbyblack

Hi guyz,
I finally received the adapters for my sweet C3G's from China and tested the vintage Sylvania 5687/Siemens C3G combo 3 days and all i can say is wow,amazing , a worthy upgrade even if i paid until now about 120$ wich for me is quite expensive.
Im so bad to describing the sound but for me is clearer,powerfull,more spacious and refined ,so better in all aspects on my system with Sennheiser HD600.Now i wait for a pair of Philips E182CC wich is possible to be better than Sylvania's(Gibosi maybe u tested them on your amp), will see and next i have reserved 2 pairs of 6SN7WGTA Sylvania and Tung Sol from a seller in my country(but i need adapters first).
Some photos including a playlist that i tested the tubes:





 With this ocasion i need to say THANKS to Hypnos1 who discovered the C3G's for our amps-you are amazing man,at first nobody hear you how good they are,Gibosi ''the GOD OF TUBES'' for me, who tested every possible combination for our LD'S,Mordy and Mikelap always nice to help and try everything,Acapella11,Audiofanboy,TrollDragon and I'm sure there are many others.
At first i wasn't so sure is gonna be a big change in comparison with 6N6P-IR/EI-6HM5 combo(i remember Mikelap said he did not notice big difference between WA6 and LD MK3 upgraded wich for me was hard to believe at that time)but for newcommers please make this upgrades you will no regret it.

THANKS!


----------



## gibosi

bobbyblack said:


> I finally received the adapters for my sweet C3G's from China and tested the vintage Sylvania 5687/Siemens C3G combo 3 days and all i can say is wow,amazing , a worthy upgrade even if i paid until now about 120$ wich for me is quite expensive.Im so bad to describing the sound but for me is clearer,powerfull,more spacious and refined ,so better in all aspects on my system with Sennheiser HD600.Now i wait for a pair of Philips E182CC wich is possible to be better than Sylvania's(Gibosi maybe u tested them on your amp),


 
  
 Glad you are enjoying them. 
  
 I have an LD 1+ so no power tubes. I do prefer the E182CC to the 5687 as a driver. However, the E182CC is not as powerful as the 5687, 0.6A heaters compared to 0.9A heaters. So it should be fine with HD600, but likely not as good as the 5687 with low-Z cans.
  
 The E182CC was manufactured in Heerlen, Holland (factory symbol ⊿) and Long Island, New York (factory symbol *). The Heerlen tube is a bit more lush, but both are very good.


----------



## WeirdChild

Hey guys. After replacing the Tung Sol 6080 that broke (?) with a new one. I can confirm the Little Dot IV has reached a new better level! Whan an upgrade! System has been stable for the last 2 hours.


----------



## northendjazz

Congrats on the stable setup
	

	
	
		
		

		
		
	


	




, new for me today a pair of grey glass RCA 6SN7GT's and a hard to find 0.5m '3.5mm to RCA' coaxial SPDIF cable to allow easy connection of my ibasso dx50 to the beresford dac.


----------



## Nicholasheadfi2

can i quickly ask i have just got into the world of tubes and wow what a variety we
 have to choose from , i just had my mk11 delivered , my laptop has packed up and all
 i have as a source is my dap the ibasso dx50 my question is how do i connect it to my little dot mk11
 i dont want to buy the wrong cable does anyone know how .
  
 cheers guys .


----------



## gibosi

nicholasheadfi2 said:


> can i quickly ask i have just got into the world of tubes and wow what a variety we
> have to choose from , i just had my mk11 delivered , my laptop has packed up and all
> i have as a source is my dap the ibasso dx50 my question is how do i connect it to my little dot mk11
> i dont want to buy the wrong cable does anyone know how .


 
  
 iBasso line out 3.5 jack to Little Dot RCA input jacks.


----------



## Nicholasheadfi2

Thank you for your help much appreciated.


----------



## bobbyblack

gibosi said:


> Glad you are enjoying them.
> 
> I have an LD 1+ so no power tubes. I do prefer the E182CC to the 5687 as a driver. However, the E182CC is not as powerful as the 5687, 0.6A heaters compared to 0.9A heaters. So it should be fine with HD600, but likely not as good as the 5687 with low-Z cans.
> 
> The E182CC was manufactured in Heerlen, Holland (factory symbol ⊿) and Long Island, New York (factory symbol *). The Heerlen tube is a bit more lush, but both are very good.


I know u have an LD 1+ but hoped you tested them on your Glenn as output tubes(probably are not compatible).I know, at least 
theoretical, tubes like 6SN7 or 6AS7 are better for high Z hphones like my SENN HD600 but right now the sound on my setup is quite good but definitely i'm gonna try everything on my LD(with C3G drivers) including the last step-6AS7.
I need to ask you something else maybe is a stupid question but...if right now i have 5687 to 6n6 adapters i can only buy 6sn7 to 5687 adapters? instead of buying socket savers for output.
I forgot to mention that all setup is dead silent,no hum at all because with that height i was little scared ,lol and the amp is colder probably heat dissipation is better.

Thanks!


----------



## Nicholasheadfi2

Hey guys
I just purchased the little dot mk11 and I'm pretty new to tube amps
I have looked at the manual and it's pretty confusing 
The part about the jumper pins 
Does the mk11 have two pins sets or three pin sets
Can't quite work out were to put the jumpers to accept
The EF95 tubes 
Can anyone help please .


----------



## gibosi

bobbyblack said:


> I need to ask you something else maybe is a stupid question but...if right now i have 5687 to 6n6 adapters i can only buy 6sn7 to 5687 adapters? instead of buying socket savers for output.
> I forgot to mention that all setup is dead silent,no hum at all because with that height i was little scared ,lol and the amp is colder probably heat dissipation is better.


 
  
 If I understand your question correctly, then yes, it is perfectly OK to stack the two adapters, a 6SN7 to 5687 and a 5687 to 6N6, to allow the use of 6SN7s as power tubes in your LD . In fact, since I have yet to purchase a 5687 to 6SN7 adapter, I do something like this to run 5687 in my Glenn: two stacked adapters, a 5687 to 6N6 and a 6N6 to 6SN7. It's ugly, but it works fine.
  
 Cheers


----------



## gibosi

nicholasheadfi2 said:


> Hey guys
> I just purchased the little dot mk11 and I'm pretty new to tube amps
> I have looked at the manual and it's pretty confusing
> The part about the jumper pins
> ...


 
  
 It depends on which version of the MKII you have. Over the years, some have switches, some have two-pin jumpers and some have three-pin jumpers. You will need to open up the amp to see which configuration you have.
  
 Which tubes did you order with the amp?


----------



## bobbyblack

gibosi said:


> If I understand your question correctly, then yes, it is perfectly OK to stack the two adapters, a 6SN7 to 5687 and a 5687 to 6N6, to allow the use of 6SN7s as power tubes in your LD . In fact, since I have yet to purchase a 5687 to 6SN7 adapter, I do something like this to run 5687 in my Glenn: two stacked adapters, a 5687 to 6N6 and a 6N6 to 6SN7. It's ugly, but it works fine.
> 
> Cheers


Yes G u understand perfectly, much appreciated your quick response!


----------



## hypnos1

weirdchild said:


> gibosi: Cleaned pins with alcohol. Used the scrap with knife thingy. Cleaned with alcohol again. Plugged in, turned them on. The heaters glow evenly and the temperature is somewhat equal to the other tube but still no sound. Swapped tubes into the sockets and the same.  anyway the replacement I ordered is arriving tomorrow.  I remember it well, first time I powerd them that tube light up blue and I saw a spark. Maybe it shorted? Thanks!


 
 Hi WeirdChild.
  
 Yep...blue flash + spark is pretty well guaranteed disaster...had a (used) GEC/OSRAM A1834 (6AS7G) power tube do that once - nearly gave me a heart attack, lol! 
	

	
	
		
		

		
		
	


	




...Luckily, the great guys at Langrex (UK) here sent me another...
	

	
	
		
		

		
		
	


	





weirdchild said:


> Hey guys. After replacing the Tung Sol 6080 that broke (?) with a new one. I can confirm the Little Dot IV has reached a new better level! Whan an upgrade! System has been stable for the last 2 hours.


 
 Glad you agree this upgrade does indeed make quite a difference...and is well worth the effort, if you can manage it...WELL DONE!   
	

	
	
		
		

		
		
	


	



  


bobbyblack said:


> Hi guyz,
> I finally received the adapters for my sweet C3G's from China and tested the vintage Sylvania 5687/Siemens C3G combo 3 days and all i can say is wow,amazing , a worthy upgrade even if i paid until now about 120$ wich for me is quite expensive.
> Im so bad to describing the sound but for me is clearer,powerfull,more spacious and refined ,so better in all aspects on my system with Sennheiser HD600.Now i wait for a pair of Philips E182CC wich is possible to be better than Sylvania's(Gibosi maybe u tested them on your amp), will see and next i have reserved 2 pairs of 6SN7WGTA Sylvania and Tung Sol from a seller in my country(but i need adapters first).
> Some photos including a playlist that i tested the tubes:
> ...


 
  
 And THANKS to you too, bb, for your appreciation. The C3g has indeed been taken on board by a good many now...(I even see it has appeared on a WooAudio amp, lol!)...and with good justification IMHO...
	

	
	
		
		

		
		
	


	




...CHEERS!


----------



## Nicholasheadfi2

hello there
  
 i have purchased the mullard m8100 Voshkod 6ZH1P-EV ef95 and Russian 6H6P-I power tubes

 this is the inside of my amp there are two jumpers one on each side .


----------



## gulakpi

Both Jumper J1 on your picture are "off" for EF95 tubes
 The M8100 and 6ZH1P-EV are EF95 type tubes.  So you can leave the jumpers as-is.  Just plug in and play.


----------



## Nicholasheadfi2

Thanks for your help guys that's great stuff no I can relax and enjoy well after a long boring burn in lol


----------



## bobbyblack

gibosi said:


> If I understand your question correctly, then yes, it is perfectly OK to stack the two adapters, a 6SN7 to 5687 and a 5687 to 6N6, to allow the use of 6SN7s as power tubes in your LD . In fact, since I have yet to purchase a 5687 to 6SN7 adapter, I do something like this to run 5687 in my Glenn: two stacked adapters, a 5687 to 6N6 and a 6N6 to 6SN7. It's ugly, but it works fine.
> 
> Cheers


Hi G
I found this adapter with 6.3V heat:http://www.ebay.co.uk/itm/191740279936?ru=http%3A%2F%2Fwww.ebay.co.uk%2Fsch%2Fi.html%3F_from%3DR40%26_sacat%3D0%26_nkw%3D191740279936%26_rdc%3D1
Is good?
Thanks!


----------



## gibosi

bobbyblack said:


> I found this adapter with 6.3V heat:http://www.ebay.co.uk/itm/191740279936?ru=http%3A%2F%2Fwww.ebay.co.uk%2Fsch%2Fi.html%3F_from%3DR40%26_sacat%3D0%26_nkw%3D191740279936%26_rdc%3D1
> Is good?


 
  
 Yep, it looks to be a quality socket with gold-plating, and since the 5687 can be configured to run using either 12.6 volt or 6.3 volt heaters, you definitely want the one built for 6.3 volts.


----------



## bobbyblack

gibosi said:


> Yep, it looks to be a quality socket with gold-plating, and since the 5687 can be configured to run using either 12.6 volt or 6.3 volt heaters, you definitely want the one built for 6.3 volts.


Yep looks like nice quality adapters,thanks again !


----------



## Johnnysound

Well, the nice diagrams by WeirdC renewed my interest about the ultimate mod for the MKIII involving 6AS7G powers with external PS. I do have the Siemens C3g as reference drivers, and it was (and still is of course) a truly entertaining experience rolling 6SN7Gs, last month I received a quartet of Tung Sol 6SN7GTB tall bottles, black plates, top getters, two NOS and two used, and this one is without doubt a great tube, full bodied and dynamic sound, linear from top to bottom, truly nice Tungsol family sound. The closest to my favorites, the ITT/Hitachi 6SN7GTBs, something special after a long warm up, delivering a spacious, ethereal, 3D presentation making my speakers dissapear from the room...never ceased to startle me in one way or another, and this is not a particularly "warm" tube, when new was very "solid state" like, super dynamic like the Tungsols, with strong, well defined bass, a prominent midband and extended highs, good but not exceptional. After 100 hours plus the tube reached a new personality, never seen before such an improvement, maybe is the construction of the tube, I dont know, but everything was more refined, more subtle, classic tube warmth appeared in the right proportion, and that liquid, captivating, natural sound. I have heard nothing better than this, with all due respect to my Hytrons and Sylvanias.

Of course, this is with my gear, SS amps and speakers, but also with my beloved Audio Technica M-50 LE, tubes sound splendid with this HP and dont be fooled by the price of less than $ 200, these are absolutely top class monitoring HPs with a sound quality far above its price, electrostatic like speed and definition plus a beautiful, dynamic bass that shows me one more time that no speaker can do what a good HP can. Period. For 
the owners of top class HPs my suggestion would be to get an M-50, just for fun. Of course, thru HPs you get pure tube sound, no other variables involved, but in my setup the MKIII OTL preamp out is very strong, driving a pair of 300 watt plus NAD monos that I had to set at less than half power, and output tubes do interact differently than with headphones. As H1 said, the C3g is such a high resolution tube that careful matching with the output triodes is mandatory. With the Tungsols, for example, the sound is hyper dynamic, great for shure with neutral, civilized HPs, but very hot, and super fun in my setup. I suspected rolling the 6AS7Gs would be too much of a good thing, but I was wrong, installed a weird test setup with one RCA 6AS7G (with separate PS) and one Tungsol 6SN7GTB, and was surprised by how similar they sounded, however, the RCA was not only taller, it sounded bigger also, full, round and beautiful, a truly NOS tube that needs a good burn in. Received this quartet, marked 926 and 6-43, I suspect from around 1951 or 52


----------



## bobbyblack

Hi guyz I need some help:I have to choose between Sylvania 6sn7wgta and Tung Sol 6sn7wgta nib for output(with C3g drivers) on my ld, how is the character of tubes,I ask because I need something detailed and not to warm, my Senn HD600 being allready warm with accentuated mid bass.

Thanks!


----------



## northendjazz

I have about a week into a pair of brown base Sylvania 6sn7wgta which I found they had more detail and are less warm than grey glass jan crc 6sn7gt . The wgta's suit what I want from my amp they also appear to have better instrument seperation and sound stage but I'm not sure if thats a result of the detail or less warmth.


----------



## gibosi

bobbyblack said:


> Hi guyz I need some help:I have to choose between Sylvania 6sn7wgta and Tung Sol 6sn7wgta nib for output(with C3g drivers) on my ld, how is the character of tubes,I ask because I need something detailed and not to warm, my Senn HD600 being allready warm with accentuated mid bass.


 
  
 In my opinion, the Sylvania is warmer than the Tung-Sol. That said, I do not consider the Sylvania to be too warm. It is certainly not as warm as the RCA.


----------



## northendjazz

While looking for a spare set of c3g's I came across D3a another "Poströhre" seems to be 6dj8 equiv don't no if I could use it on the little dot as a driver but maybe on darkvoice 336se, Does  anyone know about them?


----------



## gibosi

northendjazz said:


> While looking for a spare set of c3g's I came across D3a another "Poströhre" seems to be 6dj8 equiv don't no if I could use it on the little dot as a driver but maybe on darkvoice 336se, Does  anyone know about them?


 
  
 The D3a is a pentode, similar to the C3g, and therefore, it would be necessary to convert it into a triode for use in the Little Dot. While there are adapters on eBay which strap C3g's into triodes, I am not aware of any similar adapters for the D3a. It would be necessary to either build your own adapters or ask one of the eBay adapter vendors to build some for you. That said, there is no guarantee that it will sound good. lol. 
  
 And no, the D3a is not similar to a 6DJ8. Yes, both are 9-pin miniature all-glass bottles, but the 6DJ8 is a double triode whereas the D3a is a single pentode.


----------



## northendjazz

Ok thanks
 One for the back burner then.


----------



## hypnos1

johnnysound said:


> Well, the nice diagrams by WeirdC renewed my interest about the ultimate mod for the MKIII involving 6AS7G powers with external PS. I do have the Siemens C3g as reference drivers, and it was (and still is of course) a truly entertaining experience rolling 6SN7Gs, last month I received a quartet of Tung Sol 6SN7GTB tall bottles, black plates, top getters, two NOS and two used, and this one is without doubt a great tube, full bodied and dynamic sound, linear from top to bottom, truly nice Tungsol family sound. The closest to my favorites, the ITT/Hitachi 6SN7GTBs, something special after a long warm up, delivering a spacious, ethereal, 3D presentation making my speakers dissapear from the room...never ceased to startle me in one way or another, and this is not a particularly "warm" tube, when new was very "solid state" like, super dynamic like the Tungsols, with strong, well defined bass, a prominent midband and extended highs, good but not exceptional. After 100 hours plus the tube reached a new personality, never seen before such an improvement, maybe is the construction of the tube, I dont know, but everything was more refined, more subtle, classic tube warmth appeared in the right proportion, and that liquid, captivating, natural sound. I have heard nothing better than this, with all due respect to my Hytrons and Sylvanias.
> 
> Of course, this is with my gear, SS amps and speakers, but also with my beloved Audio Technica M-50 LE, tubes sound splendid with this HP and dont be fooled by the price of less than $ 200, these are absolutely top class monitoring HPs with a sound quality far above its price, electrostatic like speed and definition plus a beautiful, dynamic bass that shows me one more time that no speaker can do what a good HP can. Period. For
> the owners of top class HPs my suggestion would be to get an M-50, just for fun. Of course, thru HPs you get pure tube sound, no other variables involved, but in my setup the MKIII OTL preamp out is very strong, driving a pair of 300 watt plus NAD monos that I had to set at less than half power, and output tubes do interact differently than with headphones. As H1 said, the C3g is such a high resolution tube that careful matching with the output triodes is mandatory. With the Tungsols, for example, the sound is hyper dynamic, great for shure with neutral, civilized HPs, but very hot, and super fun in my setup. I suspected rolling the 6AS7Gs would be too much of a good thing, but I was wrong, installed a weird test setup with one RCA 6AS7G (with separate PS) and one Tungsol 6SN7GTB, and was surprised by how similar they sounded, however, the RCA was not only taller, it sounded bigger also, full, round and beautiful, a truly NOS tube that needs a good burn in. Received this quartet, marked 926 and 6-43, I suspect from around 1951 or 52


 
  
 Hi Johnnysound...good to see you back - shame it's not over on the Elise thread, lol! 
	

	
	
		
		

		
		
	


	




...
  
 And glad you have tasted what the 6AS7G can bring to the table...along with the C3g driver, these power tubes do indeed take the LDs to quite amazing levels, given their modest prices. And they do indeed repay the time and effort involved in getting them to work in amps that were never intended to take these beauties...WELL DONE!...and to all who take the plunge, lol!!...CHEERS!


----------



## 432789

What are these?. I have search everywhere but there is no info about them. Anyone?


----------



## MIKELAP

thebrunx said:


> What are these???. I have search everywhere but there is no info about them.


 
 Found this about amp tube are chinese described below


----------



## 432789

Thanks for this, It has really helped me more than you know, I appreciate. Now I have won it in an auction here in Germany and by grace I have also won Just the tubes I need, all in one Package. New tubes from 1954: 10xCV807 and 4xCV784 NOS "Valve Electronic" tubes (Just found out its another name Mullard was using back then, great!) Plus there are some 2xCV785s thrown in the box as well,  I don't know what im going to do with the excess of tubes, but oh well i got them for cheap. If anyone knows How This would compare to any other amp, that would be great as well, thank you.


----------



## Johnnysound

hypnos1 said:


> Hi Johnnysound...good to see you back - shame it's not over on the Elise thread, lol! :wink_face: ...
> 
> And glad you have tasted what the 6AS7G can bring to the table...along with the C3g driver, these power tubes do indeed take the LDs to quite amazing levels, given their modest prices. And they do indeed repay the time and effort involved in getting them to work in amps that were never intended to take these beauties...WELL DONE!...and to all who take the plunge, lol!!...CHEERS!


----------



## Johnnysound

Hey thanks H1 ! the PS/regulator part was easy, but not taking the cabling out of the extender with those @#$# decorative rings in
place !! the AWG table says 2.5 amps need minimum 18 AWG or 1.12 mm cable, and it barely fitted because of the insulation. You will like this one: I seriously considered using silver ribbons instead of round cable (!) I have some spare ribbons from an old project, but the equivalence was a bit on the low side. Also, I am using a 12V/6A PS which is not optimal, am waiting for a 10 amp one. And yes, no doubt the C3Gs/6AS7Gs take the little MKIII to a whole new level, even with NOS tubes that need a good burn in. 3 of my RCAs are marked 926 and one 6-43, which means 1949 and 1946 !! With all the adapters, they look like glass (flaming) towers...


----------



## d4rkch1ld

Nice setup. Could u give me info where to get 7 pin socket extender?


----------



## MIKELAP

These look like they could work just ask vendor he says tube tester                                                                                                                                                                                                                                                    http://www.ebay.com/itm/2PC-TOP-GOLD-PLATED-7pin-tube-tester-saver-for-EC92-6AK5-6C4-6AU6-CMC-Socket-/191404478168?hash=item2c90988ed8:g:wfgAAOSwEppUT3po                                                                                   What i did is just remove the rings since they are screwed in it is faster to cut them off with a dremel will look like this picture i removed front and back rings so adapters could clear if your interested let me know ill explain the procedure


----------



## d4rkch1ld

Thanks mike. I have Mk IV SE so i dont have problems with rings. I want to rid of slight hum when using double triodes as drivers. Contact is not ideal on my socket.


----------



## Johnnysound

d4rkch1ld said:


> Nice setup. Could u give me info where to get 7 pin socket extender?




Hi d4r, at Leeds Radio https://www.etsy.com/listing/213863594/vacuum-tube-test-socket-for-tube-rolling?ref=shop_home_active_1&ga_search_query=7%2Bpin%2Bsocket%2Bsaver


----------



## MIKELAP

d4rkch1ld said:


> Thanks mike. I have Mk IV SE so i dont have problems with rings. I want to rid of slight hum when using double triodes as drivers. Contact is not ideal on my socket.


 
 Well your not the only one a few guys have reported hum in the past personnally i had made my adapter and had no hum .Maybe try the SEARCH THIS THREAD FUNCTION atop the page maybe some guys found a fix as i dont remember to be honest .  This is my adapter that i used with 6DJ8 types of tubes


----------



## d4rkch1ld

When i stuck pieces of paper or pull between pins hum is gone so i know its contact problem.


----------



## WeirdChild

Unfortunately my Little Dot MK IV stopped working. Cannot say the tube modding caused it, the technician told me it could be the voltage variation coming from the wall. Anyway two resistances blew. So well yes, have to wait another week to get it back. Did not send it back to China, there{s a guy in my country that repairs, restores and build tube amps..


----------



## WeirdChild

johnnysound said:


> Well, the nice diagrams by WeirdC renewed my interest about the ultimate mod for the MKIII involving 6AS7G powers with external PS. I do have the Siemens C3g as reference drivers, and it was (and still is of course) a truly entertaining experience rolling 6SN7Gs, last month I received a quartet of Tung Sol 6SN7GTB tall bottles, black plates, top getters, two NOS and two used, and this one is without doubt a great tube, full bodied and dynamic sound, linear from top to bottom, truly nice Tungsol family sound. The closest to my favorites, the ITT/Hitachi 6SN7GTBs, something special after a long warm up, delivering a spacious, ethereal, 3D presentation making my speakers dissapear from the room...never ceased to startle me in one way or another, and this is not a particularly "warm" tube, when new was very "solid state" like, super dynamic like the Tungsols, with strong, well defined bass, a prominent midband and extended highs, good but not exceptional. After 100 hours plus the tube reached a new personality, never seen before such an improvement, maybe is the construction of the tube, I dont know, but everything was more refined, more subtle, classic tube warmth appeared in the right proportion, and that liquid, captivating, natural sound. I have heard nothing better than this, with all due respect to my Hytrons and Sylvanias.
> 
> Of course, this is with my gear, SS amps and speakers, but also with my beloved Audio Technica M-50 LE, tubes sound splendid with this HP and dont be fooled by the price of less than $ 200, these are absolutely top class monitoring HPs with a sound quality far above its price, electrostatic like speed and definition plus a beautiful, dynamic bass that shows me one more time that no speaker can do what a good HP can. Period. For
> the owners of top class HPs my suggestion would be to get an M-50, just for fun. Of course, thru HPs you get pure tube sound, no other variables involved, but in my setup the MKIII OTL preamp out is very strong, driving a pair of 300 watt plus NAD monos that I had to set at less than half power, and output tubes do interact differently than with headphones. As H1 said, the C3g is such a high resolution tube that careful matching with the output triodes is mandatory. With the Tungsols, for example, the sound is hyper dynamic, great for shure with neutral, civilized HPs, but very hot, and super fun in my setup. I suspected rolling the 6AS7Gs would be too much of a good thing, but I was wrong, installed a weird test setup with one RCA 6AS7G (with separate PS) and one Tungsol 6SN7GTB, and was surprised by how similar they sounded, however, the RCA was not only taller, it sounded bigger also, full, round and beautiful, a truly NOS tube that needs a good burn in. Received this quartet, marked 926 and 6-43, I suspect from around 1951 or 52


 
 Congrats on your build!


----------



## i luvmusic 2

weirdchild said:


> Unfortunately my Little Dot MK IV stopped working. Cannot say the tube modding caused it, the technician told me it could be the voltage variation coming from the wall. Anyway two resistances blew. So well yes, have to wait another week to get it back. Did not send it back to China, there{s a guy in my country that repairs, restores and build tube amps..


 
 If the FUSE does  what is supposed to do it should have BLOW before frying those resistors.Which tube you were using?Gave us more info so we could used your experienced from preventing any more blow up.


----------



## WeirdChild

Okay, lets see.
  
  
 RECAP:
  
 -Built the power supply mod. One 6080 flashed and sparkled. Replaced tube.

 -I was using the external power supply mod to power two 6080 functional with no issues whatsoever for about 12 days, from 4 to 6 hours each day. One day the sound from the amp was gone, but the amp and the tubes were still on. Replaced fuse. Tried power it on, was on but there was no sound. Just crackling noise when the volume was all the way up.
  
 -Opened the back panel to see if I could spot something unusual. Saw two rectangular ceramic resistances bulged. 
  
  
 -Did not take long to send it for service.
  
 This is what the technician told me:

 First he asked me to check the voltage coming from the wall outlet. checked it 3 times a day. Voltage variations: 117 to 125 during the day.

 He said the tubes were getting proper voltage and the problem was with the high voltage inside the amp. And the problem was caused because in total 4 resistances bulged. I explained the crazy mods we have tried here and he did not see this could cause the problem since we are taking load from the amps transformer. He addressed that in his experience those problems happen because of voltage variations coming from the wall, extreme heat, and cheap resistances inside amps. So, he is going to replace them with high grade ones to prevent this issue.
  
 He also said these devices are made to use 110V.

 He also recommended using a power regulator for the amp. So with the new resistances I should be using one UPS with constant 120V AC.
  
 This is so far what I know. I am happy the amp didnt become an expensive paper weight! LOL.

 Hope this helps.


----------



## WeirdChild

These are the ones that will be replaced. They are located at the back of the amp. Near the AC.


----------



## TrollDragon

Wow guys what's new?
  
 I have been gone for far too long and miss my good friend Shaffer and his Voshkod buddy!!!


----------



## Nicholasheadfi2

can anyone advise me on how to connect a dap to a dac and a tube amp .
  
 thanks guys


----------



## i luvmusic 2

Perhaps you've gone  for so long...............


----------



## i luvmusic 2

weirdchild said:


> "One 6080 flashed and sparkled. Replaced tube."
> 
> THIS IS MOST LIKELY THE COST OF THE BLOW UP OR SOME KIND OF A SHORT CIRCUIT.
> 
> ...


----------



## lglions

I do read this thread a lot (and I mean a lot). Initially got referred to it by MIKELAP (huge thanks for that and referral to 6HM5 - those were a certain upgrade from stock tubes I got with LD III).
  
 I also tried 6J1P (Voskhod) and, as you see from a picture below, Sylvania 6SN7GTA + Siemens c3g.
  
 All the info in the thread is invaluable, I had to create Evernote note to piece all the great advices together.
  
 It must've been mentioned many times: every advice has to be interpreted considering which headphones are being used. I learned that set of tubes that make my Oppo PM-3 sound great is not optimal for my Beyers (which I got from Massdrop to have something of high impedance at 600 Ohms).
  
 For Oppo PM-3 (low impedance) - 6N6P with 6J1P or 6HM5 sounds great to me. Updating power tubes to 6SN7 make Oppos rattle at medium to high volume (they rattle with any drivers). 
  
 For Beyers - 6SN7GTA / c3g proved to be the best. I bought two pair of c3g - one Siemens and one Telefunken. Will try to make a side by side comparison and figure if I can hear any difference.
  
*Question:* For 6SN7GTA / c3g advocates - what headphones do you use that make this tube combo a top choice of you?
  
 My setup so far (additional costs - 6SN7 ~$25, c3gs - ~$80, adapters for both - ~$60, socket savers - ~$15). I use Oppo HA-2 as a DAC fed from MacBook Pro / iTunes.
  
 I got 6HM5 for $5 a pair and Voskhods were $2+$8 shipping.


----------



## MIKELAP

lglions said:


> I do read this thread a lot (and I mean a lot). Initially got referred to it by MIKELAP (huge thanks for that and referral to 6HM5 - those were a certain upgrade from stock tubes I got with LD III).
> 
> I also tried 6J1P (Voskhod) and, as you see from a picture below, Sylvania 6SN7GTA + Siemens c3g.
> 
> ...


 
 Hi ,there is alot of stuff in the thread me to had to take notes .For my part i am still using the Senns HD800 i dont get tired of those HP are those the DT990 i listen to those once and i remember liking them ,by the way nice color  .That's probably my better sounding setup C3G and 6SN7on the MK3. without using a power supply to use the 6as7 tubes power tubes . i  eventually removed  those rings around the sockets brings everything a little closer to the ground  dont have to use extenders .Presently using 6GU7 and 6AU6 as drivers . that's the fun of it its possible to have decent tubes and sound for cheap .Keep on rollin .


----------



## lglions

Senns HD800 is what I wanted to get, when I stumbled upon this forum. At that time I probably had a question that most people here would have as lame: Senns vs Grados. 
  
 Then found very many other options and suggestions. Thus decided to try different HFs, amp styles before settling on something of a grade of HD800s or Woo Audio amps.
  
 Pretty sure HD 800s are amazing. DT990 are a bit too bright for my taste, but it's possible to tame the brightness a bit.
  
 Perhaps after all the journey I will end up with Senns (and something else), but so far it was fun.
  
 Going back to my question: do you think that 6SN7s will perform well only with high impedance HFs? Shall I play with gain settings (now I have them on high)?


----------



## d4rkch1ld

lglions said:


> Going back to my question: do you think that 6SN7s will perform well only with high impedance HFs? Shall I play with gain settings (now I have them on high)?


 
 In my experience yes they sound good with my DT 880 600ohm and HD 600 but with lower impedance phones sound is bloated even distorted.
 You should make the last step and go for 6AS7G powers u just need power supply and tubes. I think u will be amazed by performance even with cheap soviet tubes especialy with lower impedance headphones.


----------



## hypnos1

weirdchild said:


> Unfortunately my Little Dot MK IV stopped working. Cannot say the tube modding caused it, the technician told me it could be the voltage variation coming from the wall. Anyway two resistances blew. So well yes, have to wait another week to get it back. Did not send it back to China, there{s a guy in my country that repairs, restores and build tube amps..


 
  
 Hi WC...sad to hear of your disaster!
  
 As ilm2 says, our LDs are indeed pushed hard using these different tubes, and there is always a slight risk involved. However, although my MKIV SE ran a good bit hotter, I never had the slightest hint of a problem - and that was after MANY hours' use. And I can't recall anyone else having such a disaster as yours...from what your repair man did and said, it looks most likely to be down to the inevitably cheaper components used by many Chinese manufacturers in order to keep the prices so "attractive". Unfortunately, it then comes down to _luck_ with regard to the _quality control/__reliability _of said components. Sadly, those particular resistors in your unit were very probably in the _*un*lucky_ sector, lol!! 
	

	
	
		
		

		
		
	


	




. But with better quality replacements, I'm sure you should be fine to go - and I would hope none of the other components fall into this unfortunate category! 
	

	
	
		
		

		
		
	


	



  
 The LDs are truly good value-for-money nonetheless, but this long-term reliability factor is just one reason why I dug deeper into the wallet and went in search of something new - hence my foray into the world of the Elise!
  
 I do hope you have no further problems with your amp, and continue to gain much enjoyment from her...


----------



## d4rkch1ld

lemonjelly said:


> Just an update after installing 2 x Thomson 6080s (6SA7 type) instead of the 6n6ps.  The current draw from my old config went from less than 50mA with the 6n6ps to over 170mA with the 6080s (over 80mA per 6080)... so I wanted to reduce that.  And the increased current also meant the 6SN7 tube was getting a much lower voltage because of the power loss in the power resistors (the 2 180s), so it went down to around 3mA from the 5+mA previously.  The main reason I wanted to reduce the current was to find a better operating point for the 6080s + the 6SN7, but I wonder how well the transformer handles the increased current (the largest current with an "official" upgrade of DRs + EF91s would be less than 100mA), and the power resistors are also seeing pretty large wattage:
> V = IR, so @ 170mA, V = 0.17*180 = 30.6v... so P = VI = 30.6*0.17 =  5.202W (ie exceeding the rating of the 5W resistors).
> 
> And for anyone using the 6AS7s, I'd assume with the stock LD mk IV you might see less than 170mA (cos of the 120 resistors being replaced with 150s), but with the LD mk III I would possibly expect this current or higher (I had a larger cathode resistor @ 200 than the stock mk III which will have reduced the current a little).  These are assumptions though as I say... my amp is pretty far from stock at this point (although a lot of the values that matter are still the same), so YMMV.
> ...


 

 I rebembered this post when i was considering to mod my little dot. I guess this is explanation why resistors blew up.


----------



## MIKELAP

lglions said:


> Senns HD800 is what I wanted to get, when I stumbled upon this forum. At that time I probably had a question that most people here would have as lame: Senns vs Grados.
> 
> Then found very many other options and suggestions. Thus decided to try different HFs, amp styles before settling on something of a grade of HD800s or Woo Audio amps.
> 
> ...


 
 Maybe if you find the DT990's to be to bright you better try the Senns before buying them. For example when  i went from the Denon's D-5000 with that big bass to the Senns more neutral sounding sig  i needed my brain to ajust  but i never found them bright but some people do. After awhile i found the bass level to be more realistic than the Denon's.Most say the MK3 works well with high impedance HP not so much with low impedance HP imo i dont know if ajusting gain will change anything except volume level .As for the 6SN7 will have to give another listen but from what i remember it warms up the sound for shure .Of course YMMV.


----------



## lglions

d4rkch1ld said:


> In my experience yes they sound good with my DT 880 600ohm and HD 600 but with lower impedance phones sound is bloated even distorted.
> You should make the last step and go for 6AS7G powers u just need power supply and tubes. I think u will be amazed by performance even with cheap soviet tubes especialy with lower impedance headphones.


 
 Thanks, I will re-read 6AS7G mod guide to decide if I have chops and time to go with it.


----------



## lglions

mikelap said:


> Maybe if you find the DT990's to be to bright you better try the Senns before buying them. For example when  i went from the Denon's D-5000 with that big bass to the Senns more neutral sounding sig  i needed my brain to ajust  but i never found them bright but some people do. After awhile i found the bass level to be more realistic than the Denon's.Most say the MK3 works well with high impedance HP not so much with low impedance HP imo i dont know if ajusting gain will change anything except volume level .As for the 6SN7 will have to give another listen but from what i remember it warms up the sound for shure .Of course YMMV.


 
 Good thing about Senns they are quite popular and me leaving in Bay Area it won't be that hard to find a place where I can try them.
  
 I even went to Oppo office to try their HPs and amps. To their credit they had a wide variety of other company's HPs to compare with.
  
 DT990 have elevated treble, so brightness comes to them naturally. If not tamed by a darker tube amp or EQ, when song comes with a long "S" it can cut a hole in one's untrained ear. On a brighter side (no pun intended) it is possible to hear details in treble no other HPs exposed for me. 6SN7 / c3g made them sound warmer.


----------



## hypnos1

lglions said:


> Good thing about Senns they are quite popular and me leaving in Bay Area it won't be that hard to find a place where I can try them.
> 
> I even went to Oppo office to try their HPs and amps. To their credit they had a wide variety of other company's HPs to compare with.
> 
> DT990 have elevated treble, so brightness comes to them naturally. If not tamed by a darker tube amp or EQ, when song comes with a long "S" it can cut a hole in one's untrained ear. On a brighter side (no pun intended) it is possible to hear details in treble no other HPs exposed for me. 6SN7 / c3g made them sound warmer.


 
  
 Glad you found a 6SN7 to tame the C3g/Beyer treble somewhat...sometimes my Siemens C3gS's amazing treble was just a bit too much for my T1s, lol! But so long as there aren't _too_ many "Ssss"s, that detail is indeed phenomenal....(and does wonders for the more laid-back HD650s!!).


----------



## northendjazz

My new to me MKiV arrived today 
	

	
	
		
		

		
		
	


	




, put the C3g + 6sn7 + DT880 combo from the MKII in and whoosh straight to better sound stage more weight to the bass and controlled the treble.  Everything bigger and better so I think I'll go and enjoy it.


----------



## gibosi

Very interesting. I have always wondered if the MKIV sounded any different, with the same tubes, than the MKII (and MKIII). This is very good information.
  
 Cheers


----------



## northendjazz

Yep, it also feels good to give a tiny crumb of info back to this thread 
	

	
	
		
		

		
			





 I've not read every page but its been a big help. The MKII was a test about five months of daily use and it was cheap enough to get a taste for tube amps. I will send it to a new home and have some cash back in my pocket.


----------



## hypnos1

northendjazz said:


> My new to me MKiV arrived today
> 
> 
> 
> ...


 
  
 Great combination, northendjazz...lots of enjoyment ahead, I'm sure!...


----------



## WeirdChild

Hi! Got my MK IV back to me after the repair/upgrade thingy! Now it sounds better than ever, I have been able to use a pair of chatham 6AS7G I got for a cheap price and arrived after the poor MK IV got sick and was away from me, so it is the first time I am able to try them.
  
 Chatham 6AS7G compared to the Tung-Sol 6080, the coke bottles irradiate less heat (which is something good for our external power supply modded amps). 
  
 *Metals and strings sharper and more detailed.
  
 *Bass is tighter and more responsive.
  
 *When used as a preamp my Audioengines A5+ sound way better too!
  
  
 **** About my earlier and sad experience with the Little Dot the service guy did and amazing job repairing and upgrading the amp. These are the parts he replaced based on his recommendations, he changed them for better quality ones and said the power distribution inside the amp is better and more sturdy.
  
 You can see the bulged and burnout resistors, the other ones that look ok were upgraded to prevent any further problems related to heat or power variations. Power cables were upgraded too.
  
 Anyone who attemps to to the external supply mod just be careful. Although I dont recall making a big time mistake, I can just say I was unlucky, but is better to be protected. Always watch the temp of the amp. Check the PS voltage once in a while. 6.3. v. and If you can use a power regulator or UPS.
  
 Happy listening!


----------



## WeirdChild

hypnos1 said:


> Hi WC...sad to hear of your disaster!
> 
> As ilm2 says, our LDs are indeed pushed hard using these different tubes, and there is always a slight risk involved. However, although my MKIV SE ran a good bit hotter, I never had the slightest hint of a problem - and that was after MANY hours' use. And I can't recall anyone else having such a disaster as yours...from what your repair man did and said, it looks most likely to be down to the inevitably cheaper components used by many Chinese manufacturers in order to keep the prices so "attractive". Unfortunately, it then comes down to _luck_ with regard to the _quality control/__reliability _of said components. Sadly, those particular resistors in your unit were very probably in the _*un*lucky_ sector, lol!!
> 
> ...


 
  
 Hi hypnos1! I think I was just unlucky! Followed every safety measures and still got the problem, but got the thingy back and is rocking better than ever. Yes we are grinding gears and pushing the amps a lot! But hey, we were not born rich and well, modding is an enjoyable trip too hehe.
  
 While my was away I couldnt help but had to tinkle my sound card and upgraded some things on it too! Now that everything is set I am reaping the rewards of the craziness.  Glad you are enjoying your new amp! Sounds like a great future buy, but as of now I will enjoy my LD more and more, my first tube amp ever and have only had it for a a bit more than month now hehe.
  
 Ok back to tube rolling!


----------



## Johnnysound

hypnos1 said:


> Great combination, northendjazz...lots of enjoyment ahead, I'm sure!...




Great combination indeed in the MKIII, H1. I use it as a preamp 99% of the time (as Mordy does) and the C3Gs/6SN7s work extremely well in this role. Different from HPs, if the 6SN7GT family have any problems (as powers) with high impedance cans, this is not the case (of course) as preamp outs, due to the low input impedance of SS amps, in my case. Plenty of power, at 1/4 gain sound very loud, clear and musical, with plenty of body... There MUST be some technical reason why tube OTL preamps as the MK series and the Elise couple so well with SS amps, up to the point you forget they are SS!! Thats why I was not too excited about the 6AS7G mod, the big bottles get hot like an oven but sound splendid...and yes, ahead of the 6SN7gs but not by a very big margin in preamp duties...I feel. On the other hand, the HP outs are "pure tube" without any SS "contamination" !! (LOL) I really would like to find some impressions about these preamps paired with tube amps...


----------



## hypnos1

weirdchild said:


> Hi hypnos1! I think I was just unlucky! Followed every safety measures and still got the problem, but got the thingy back and is rocking better than ever. Yes we are grinding gears and pushing the amps a lot! But hey, we were not born rich and well, modding is an enjoyable trip too hehe.
> 
> While my was away I couldnt help but had to tinkle my sound card and upgraded some things on it too! Now that everything is set I am reaping the rewards of the craziness.  Glad you are enjoying your new amp! Sounds like a great future buy, but as of now I will enjoy my LD more and more, my first tube amp ever and have only had it for a a bit more than month now hehe.
> 
> Ok back to tube rolling!


 
 Yep WC...modding may have its trickier moments, but often brings great (and unexpected!) results..."Fortune favours the brave"!! 
	

	
	
		
		

		
		
	


	




...
  
 You have indeed chosen a very good, reasonably priced amp to start your journey in tubeland...but be warned : once the bug _really_ bites, it sure is hard to steer clear of gibosi's "rabbit hole", lol! 
	

	
	
		
		

		
		
	


	




. At least being forewarned, you can start saving now...and the Elise should be at the top of your list IMHO! 
	

	
	
		
		

		
		
	


	



  
 HAPPY LISTENING!  
	

	
	
		
		

		
		
	


	



  
  


johnnysound said:


> Great combination indeed in the MKIII, H1. I use it as a preamp 99% of the time (as Mordy does) and the C3Gs/6SN7s work extremely well in this role. Different from HPs, if the 6SN7GT family have any problems (as powers) with high impedance cans, this is not the case (of course) as preamp outs, due to the low input impedance of SS amps, in my case. Plenty of power, at 1/4 gain sound very loud, clear and musical, with plenty of body... There MUST be some technical reason why tube OTL preamps as the MK series and the Elise couple so well with SS amps, up to the point you forget they are SS!! Thats why I was not too excited about the 6AS7G mod, the big bottles get hot like an oven but sound splendid...and yes, ahead of the 6SN7gs but not by a very big margin in preamp duties...I feel. On the other hand, the HP outs are "pure tube" without any SS "contamination" !! (LOL) I really would like to find some impressions about these preamps paired with tube amps...


 
  
 Yes indeed, J...as preamp out into my Vincent integrated, both my MKIV SE and Elise (with fancy tubes - but as you say, not necessarily needing the power of the 6AS7G/6080 in the LD) take things to a much higher level. But into a _tube_ power amp has me drooling _*big*_ time, lol!...(shame I can hardly ever get to use the speakers, alas...hence now my  addiction to HPs - especially my Beyer T1s! 
	

	
	
		
		

		
		
	


	




). Let's just hope some lucky owner is able to get us all green with envy!


----------



## hypnos1

weirdchild said:


> Hi! Got my MK IV back to me after the repair/upgrade thingy! Now it sounds better than ever, I have been able to use a pair of chatham 6AS7G I got for a cheap price and arrived after the poor MK IV got sick and was away from me, so it is the first time I am able to try them.
> 
> Chatham 6AS7G compared to the Tung-Sol 6080, the coke bottles irradiate less heat (which is something good for our external power supply modded amps).
> 
> ...


 
  
 Great info for all LD-modders, WC (and not just LD owners, I wager!)...every cloud does indeed have a silver lining, lol..
	

	
	
		
		

		
		
	


	




...(And a great repair man you have there..._very_ handy!). Any chance of naming_ precisely _the make and rating of those replacements for folks?...
  
 And yes, those Chathams certainly are excellent tubes...you have to pay a _*lot*_ more to improve on those IMHO...and even then, that's only really worthwhile if everything else is upgraded a good few notches also (again IMHO...).
  
 CHEERS!


----------



## northendjazz

Severe rain/weather "modded" our local electric substation. So no power for the weekend but its good to be back up and running. I have a question about adapters for 6sn7's I have these
 http://www.ebay.co.uk/itm/221065459067 but they are a little tight on the pins so tube rolling is like a strength test.  I'd like to try some NU 6sn7's I have but they have cracks in the bases and I don't want to risk a breakage of the base. So can anyone recommend an adapter that its easier to swap different 6sn7's.


----------



## MIKELAP

northendjazz said:


> Severe rain/weather "modded" our local electric substation. So no power for the weekend but its good to be back up and running. I have a question about adapters for 6sn7's I have these
> http://www.ebay.co.uk/itm/221065459067 but they are a little tight on the pins so tube rolling is like a strength test.  I'd like to try some NU 6sn7's I have but they have cracks in the bases and I don't want to risk a breakage of the base. So can anyone recommend an adapter that its easier to swap different 6sn7's.


 
 These are better quality than the black plastic  ones i have the plastic ones had problems at first but they sent me another one   http://www.ebay.co.uk/itm/1piece-gold-plated-6SN7-B65-to-Mullard-6CG7-Tube-converter-adapter-/191628463526?hash=item2c9df24da6:g:VQAAAOSwyQtVoKwq                                                                                                                                                                                                                                                                                                                                                                                                                   I have those same brass adapters so far they work great. If you have cracks in your bases maybe you could use some crazy glue that's what i use when i have lose bases.


----------



## northendjazz

Ok, thanks I'll try the ones you pointed out, some glue and tape to the base.


----------



## Gezzaman

Hey everyone, 
  
  I want to try out some 6SN7 driver tubes and 6AS7 Power Tubes on my LD mk3
  

 I got a good idea how to attach a an external power supply to a voltage regulator to get 6.3v for the Power Tubes. 
  
 What i am puzzled at is how you guys attach the wires from the regulator to the converter sockets. ( not the best electrician... )


----------



## northendjazz

I wanted try 6AS7/6080 power tubes at some point but I'm not up to the skill level needed, so I bought this amp instead

  
 It uses 12AU7 and 6080's made in Germany I know its not the right thread but can some one confirm I can use 12AT7 12AX7 and 6SN7 via adapter? and 6AS7G as power tubes?
  
 I'll be keeping MKiv C3g / 6SN7 combo as I'm really enjoying it the more I listen, I'll have to split time between amps


----------



## gibosi

gezzaman said:


> Hey everyone,
> 
> I want to try out some 6SN7 driver tubes and 6AS7 Power Tubes on my LD mk3
> 
> ...


 
  
 Two posts that might be helpful:
  
 http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/6120#post_10544620
  
 http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/6405#post_10612269


----------



## gibosi

northendjazz said:


> I wanted try 6AS7/6080 power tubes at some point but I'm not up to the skill level needed, so I bought this amp instead
> 
> 
> It uses 12AU7 and 6080's made in Germany I know its not the right thread but can some one confirm I can use 12AT7 12AX7 and 6SN7 via adapter? and 6AS7G as power tubes?
> ...


 
  
 You might be able to use 12AT7 and 12AX7 in this amp. Or maybe I should say, that yes, you can plug them in and they will work, but they might not sound very good. Both the 12AU7 and 6SN7 have an Amplification Factor of about 20. So the 6SN7 should be fine. However, the 12AT7 has an AF of 60, three times that of a 12AU7. And the 12AX7 has an AF of 100, five times that of the 12AU7. As the circuit is designed around a tube with an AF of 20, these others may well have too much gain. However, you won't know until you try them. If the 12AT7 and 12AX7 sound pretty good, you might want to try some 5751.


----------



## northendjazz

Ok thanks gibosi, I have tried a 12AT7 it sounded good, I just don't want to start a small fire inside the amp. I'll keep the JAN CBRZ 12AU7's in for now and start rolling tubes in the new year.


----------



## gibosi

northendjazz said:


> Ok thanks gibosi, I have tried a 12AT7 it sounded good, I just don't want to start a small fire inside the amp. I'll keep the JAN CBRZ 12AU7's in for now and start rolling tubes in the new year.


 
  
 12AT7 and 12AX7 are perfectly safe to use. The only thing that matters is how they sound.
  
 Have fun!


----------



## dennis611

Hi guys
  
 Got myself a pre-loved LD MKIV SE pairing my HD650 and loving it so far.
 Previous owner provided some extra tubes which requires strapping.
 Have been reading this thread and frankly 600+ pages is no joke...
 Things is I haven't any clue how strapping is done and would appreciate if someone here can enlighten me
 Thanks so much


----------



## gibosi

"Strapping" involves the use of a small piece of "U" shaped wire to connect two pins together in the driver socket. 
  
 These posts might help....
  
 http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/870#post_9258255
  
 http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/1140#post_9392055


----------



## MIKELAP

dennis611 said:


> Hi guys
> 
> Got myself a pre-loved LD MKIV SE pairing my HD650 and loving it so far.
> Previous owner provided some extra tubes which requires strapping.
> ...


 
 You probably know about page 77 those are most of the tubes we tried but not all of them .About strapping lets say for example maybe you have the 6AU6 tube if you look at page 77 you see that it is a EF95 type tube you also see below the +2/7 socket wire mod that means that in order to be able to use this tube you need to strap or join socket holes 2 and 7 in your amp with a very small wire in both left and right driver socket (front) like on picture #2 left what i did is take the wire and make a U shape and insert in left and right socket then you insert tube same as usual in socket ,pin of the tube  will touch the wire That's the cheapest way to use the tubes but there's ready made adapters also which is better in the long run because inserting the tube pin and wire will loosen the socket hole if you strap tubes often .


----------



## dennis611

Thanks so much ..tried and worked.
My other tubes previously had humming and with strapping, it gone.


----------



## bjj51

Just wanted to double check, these are the tall 6hm5 driver tubes that are so highly recommended right? Just ordered 2 for $10:

http://m.ebay.com/itm/300879467071?_mwBanner=1


----------



## MIKELAP

bjj51 said:


> Just wanted to double check, these are the tall 6hm5 driver tubes that are so highly recommended right? Just ordered 2 for $10:
> 
> http://m.ebay.com/itm/300879467071?_mwBanner=


 
 Thats them .


----------



## WilliamLeonhart

Are these also the same? I ordered mine but have not received it yet
  
  
 http://www.ebay.com/itm/EI-6HM5-EC900-6HA5-6HQ5-former-Yugoslavia-MATCHED-PAIR-TUBE-NOS-/400771715218?hash=item5d4fdb1092:grcAAOSwDk5UEhHk


----------



## dennis611

bjj51 said:


> Just wanted to double check, these are the tall 6hm5 driver tubes that are so highly recommended right? Just ordered 2 for $10:
> 
> http://m.ebay.com/itm/300879467071?_mwBanner=1



Using these tubes too. Sounds great.


----------



## dennis611

Btw are there any other configuration on strapping besides the 2 -7 pin socket wire mod?


----------



## bjj51

dennis611 said:


> Using these tubes too. Sounds great.




Yea I'm excited to hear them. 

Can anyone compare their sound to the popular voshkod 6z or Mullard 8100?


----------



## gibosi

dennis611 said:


> Btw are there any other configuration on strapping besides the 2 -7 pin socket wire mod?


 
  
 It depends on the tube. The purpose of strapping in the socket is to allow tubes with a pinout different than that of EF91/EF92/EF95 tubes to be used in the Little Dot. On page 77 you can find a list of tubes we tried and the measures we used to make them work.
  
 http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/1140#post_9392055


----------



## dennis611

Ok .. Thanks so much gibosi


----------



## gr34td3str0y3r

Uhhh. What. 700 pages!? 

I just ordered my mark IV SE and a pair of 650s. Never read so much can praise for a pairing before. Had my eye on both for nearly two years and just found them both for 299 each (new). 

Sorry for being lazy... But I'm not reading through 700 pages. Anyone mind just giving me a TLR for the following question:
Do I really need to upgrade the tubes in the SE version? 
what kind of cash are we talking about to hear an upgrade. I read on the mark IV appreciation thread one user had tubes worth more than the amp. That's nuts. I think I would just get a wa22 instead.


----------



## d4rkch1ld

gr34td3str0y3r said:


> Do I really need to upgrade the tubes in the SE version?
> what kind of cash are we talking about to hear an upgrade. I read on the mark IV appreciation thread one user had tubes worth more than the amp. That's nuts. I think I would just get a wa22 instead.


 
 U can start with cheaper tubes to tailor the sound to your preferences. Soviet tubes are cheap and some sound really good or Yugoslavian 6HM5. Next step is getting adapters and move to bigger tubes and in last stage external power supply to power 6AS7 output tubes.
 Is it worth it? Hell yeah! From great sounding amp u get amazing sounding amp. I think u can make upgrade to stage 3 for like 100 dollars. But it requires some DIY skills to do it.


----------



## gibosi

gr34td3str0y3r said:


> Do I really need to upgrade the tubes in the SE version?
> what kind of cash are we talking about to hear an upgrade. I read on the mark IV appreciation thread one user had tubes worth more than the amp. That's nuts. I think I would just get a wa22 instead.


 
  
 If you are happy with the sound of a stock IV, then of course, you don't have to upgrade the tubes. As far as how much to spend, you can spend as little or as much as you want.
  
 And I should note, that if you get a wa22, it is just as easy to spend more on tubes than that amp costs too! lol


----------



## gulakpi

gibosi said:


> If you are happy with the sound of a stock IV, then of course, you don't have to upgrade the tubes. As far as how much to spend, you can spend as little or as much as you want.
> 
> And I should note, that if you get a wa22, it is just as easy to spend more on tubes than that amp costs too! lol


 
 Haha!  I couldn't agree more!   Once  you're into a hobby...........


----------



## Nicholasheadfi2

I am fairly new to tube amps just purchased the mk11 and am using my ibasso dx50 as a source
I know that the ibasso has a built in DAC but my newbie question is 
Is the dx50 the best choice as a source what would be better 
And can I connect a DAC to the mk11 and use the dx50 still as the source.
How do these things connect together please post a pic if someone has this set up .
Thanks people .


----------



## Nicholasheadfi2

I am fairly new to tube amps just purchased the mk11 and am using my ibasso dx50 as a source
I know that the ibasso has a built in DAC but my newbie question is 
Is the dx50 the best choice as a source what would be better 
And can I connect a DAC to the mk11 and use the dx50 still as the source.
How do these things connect together please post a pic if someone has this set up .
Thanks people .


----------



## gr34td3str0y3r

nicholasheadfi2 said:


> I am fairly new to tube amps just purchased the mk11 and am using my ibasso dx50 as a source
> I know that the ibasso has a built in DAC but my newbie question is
> Is the dx50 the best choice as a source what would be better
> And can I connect a DAC to the mk11 and use the dx50 still as the source.
> ...


 
 I was curious about your post:
 First off why do you want to use a different dac? Do you already have a better one? The Dx50 is supposed to be a really good dac to start off with. 
 but I was reading about your Dx50 and the it says you have an output on your Dx50 for exactly what you are talking about. if you want to bypass the Dx50s built in dac use the " line-level and mini (3.5mm) coaxial output ". From the pics its right next to your 3.5mm headphone out.


----------



## Nicholasheadfi2

gr34td3str0y3r said:


> I was curious about your post:
> First off why do you want to use a different dac? Do you already have a better one? The Dx50 is supposed to be a really good dac to start off with.
> but I was reading about your Dx50 and the it says you have an output on your Dx50 for exactly what you are talking about. if you want to bypass the Dx50s built in dac use the " line-level and mini (3.5mm) coaxial output ". From the pics its right next to your 3.5mm headphone out.


Yes it's a pretty decent dac in the dx50 and no I do not have a better one at the mo , I just was wondering if I use a more expensive dac in the chain the sound quality will be better , is this the case , I have no experience with dacs at all just want the best possible set up .
Surely the dac in the dx50 can't be better than say for example the musical fidelity m1 or any other dac in that price range , all I want to know is if that will be an improvement in sound quality .
Thank you for your reply greatly appreciated.


----------



## Gezzaman

Where would be a good place to get a pair of EF95  (7 pin) tube extenders?
 I live in Australia and the checked Leedsradio but does not ship over to here.
  
 Also what is the minimum Amps needed for the external power supply?


----------



## lglions

gezzaman said:


> Where would be a good place to get a pair of EF95  (7 pin) tube extenders?
> I live in Australia and the checked Leedsradio but does not ship over to here.
> 
> Also what is the minimum Amps needed for the external power supply?


 
 I have these: 
 http://www.ebay.com/itm/201381958186?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT
  
 He ships worldwide.
  
 Another option: http://www.ebay.com/itm/191404478168?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT
 But you will need to remove rings to use it.


----------



## Trancedoc

I also have the first listed.  They worked fine for extending the socket on my MK III so I could then use a C3G socket to 7 pin converter.  They are pretty flimsy and one fell apart while removing the converter.  As long as you don't use it as an actual socket saver, you will be satisfied with it.


----------



## MIKELAP

gezzaman said:


> Where would be a good place to get a pair of EF95  (7 pin) tube extenders?
> I live in Australia and the checked Leedsradio but does not ship over to here.
> 
> Also what is the minimum Amps needed for the external power supply?


 
 If you remove the rings you wont need socket savers and your tubes are going to sit  lower  in the amp nicer


----------



## Gezzaman

Thanks for the reply guys!

 Ill try the first ebay link as it is so much cheaper than the 2nd one. I agree the 2nd option will look better long term but that price difference is insane...
  
 Any idea where to get a 7 pin to Octo converter? ( i swear anything to do with 7 pins bottom is hard to find... either it is a converter for 7pin on top 8 pin bottom, or everything else is for octo and 9 pins)


----------



## GnuB

I have done a lot of studying on this thread (BTW Thanks D.o.A and other contributors) and am still a bit cornfused about a few things as posts may be for MKII, MKIII and MKIV without saying explicitly.
  
 My MK III was a recent MassDrop purchase and has the RTC 5654 RT drivers and 6H6 (some symbol) 1082 power tube and am considering my first foray into tube rolling keeping the MKIII stock (not interested in mods at the moment). First off, it is a sweet sounding amp as is (about 20 hrs burn in) and I tend to favor soundstage and vocal presentation (Nora Jones, Alison Krauss) but also enjoy the occasional rocker (Dream Theater, Eagles, Dire Straits). 
  
 So here are my questions:
  
 1. There is an ebay sale for the RTC 5654 RT which states "*Made by Mullard and branded by RTC. The tubes have black plate and large round holes on each side." *Is this the default tube for new MKIII builds?  I thought they used Chinese driver tubes.
  
 2. Some posts about the Power tubes indicate that the 6H30 series tubes could only be used in Version 2 of the MkIII without the resistor mod.  Do I have to open the case to tell the version or would the recent ship date make it a version 2 or higher?  I am considering the EH 6H30Pi.


----------



## GnuB

As usual, I find an answer just after I post.  The RTC 5654 RT tubes are a $17 upgrade on the little dot  site.


----------



## MIKELAP

gnub said:


> As usual, I find an answer just after I post.  The RTC 5654 RT tubes are a $17 upgrade on the little dot  site.


 
 This is one of the top plug&play drivers we found on this thread the 6HM5 tall bottle made in Yugoslavia $5.00 each  this link price is for 4 tubes look for pairs if you want on this sellers site but if your willing to buy ready made adapters things get even better im talking about 6sn7 as power tubes and c3g drivers this is with the mk3 model .                                                                                                                                                                          http://www.ebay.com/itm/251611916081?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT


----------



## MIKELAP

mikelap said:


> gnub said:
> 
> 
> > As usual, I find an answer just after I post.  The RTC 5654 RT tubes are a $17 upgrade on the little dot  site.
> ...


----------



## GnuB

>  2. Some posts about the Power tubes indicate that the 6H30 series tubes could only be used in Version 2 of the MkIII without the resistor mod.  Do I have to open the case to tell the version or would the recent ship date make it a version 2 or higher?  I am considering the EH 6H30Pi.
  
 So another find. The version number can be seen by looking in the peephole near the foot on the volume side.  Mine is version 4.


----------



## MIKELAP

gnub said:


> >  2. Some posts about the Power tubes indicate that the 6H30 series tubes could only be used in Version 2 of the MkIII without the resistor mod.  Do I have to open the case to tell the version or would the recent ship date make it a version 2 or higher?  I am considering the EH 6H30Pi.
> 
> So another find. The version number can be seen by looking in the peephole near the foot on the volume side.  Mine is version 4.


 
 Yes you can use the  6H30Pi in your amp but the 6n6p-ir are cheaper and better .I have 2 pairs of Elektro Harmonix 6h30pi-EH gold pins that i dont  use .i either use the 6N6P-IR or the 6SN7                                                                                                                                                                           http://www.ebay.com/itm/171310973012?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT


----------



## GnuB

Thanks MIKELAP.
 >This is one of the top plug&play drivers we found on this thread the 6HM5 tall bottle made in Yugoslavia $5.00 each.
  
 I did some research to find posts on the sound signature of the 6HM5.  Some posts suggested that they were warmer than the Voskhod and at least one suggested some apparent congestion on heavy instrumented tracks.  Hard for me to decide based on what I saw so far.  I like what I saw in the description of the Mullard M8100 at the beginning of this thread. I would go for it if the 6HM5 sounds like that description.
  
 Anyhoo, already got some Electro Harmonix power tubes and Voskhod 6J1P-EV driver tubes on the way.  Adding a matched pair of 6HM5 drivers might round out the selection if they sound better than the RTC 5654 RT drivers that I already have.


----------



## lglions

gnub said:


> Thanks MIKELAP.
> >This is one of the top plug&play drivers we found on this thread the 6HM5 tall bottle made in Yugoslavia $5.00 each.
> 
> I did some research to find posts on the sound signature of the 6HM5.  Some posts suggested that they were warmer than the Voskhod and at least one suggested some apparent congestion on heavy instrumented tracks.  Hard for me to decide based on what I saw so far.  I like what I saw in the description of the Mullard M8100 at the beginning of this thread. I would go for it if the 6HM5 sounds like that description.
> ...


 
 Just burn in Voskhod's. Out of the box they sounded like nothing special, but after heavy burn in they significantly improved.
  
 6HM5 is a real bargain for the price. MIKELAP hooked me up with those earlier and I loved them.


----------



## MIKELAP

lglions said:


> gnub said:
> 
> 
> > Thanks MIKELAP.
> ...


 
 Burn in time is said to be 100+ hours on Voskhod


----------



## GnuB

http://www.ebay.com/itm/251691711374
  
 Are these the Tall Bottle versions?


----------



## Oskari

gnub said:


> http://www.ebay.com/itm/251691711374
> 
> Are these the Tall Bottle versions?




Yes


----------



## MIKELAP

gnub said:


> http://www.ebay.com/itm/251691711374
> 
> Are these the Tall Bottle versions?


 
 Yes they are but those are more expensive the link above was 4 tubes for around $20.00 .By the way dont waste your money on matched pairs


----------



## GnuB

OK. Sold.  Ordered the lot of 4.


----------



## papy

Hello All, 
 It has been quite a long time since i had lurked that regularly on Head-Fi but I had to post in this thread to pass my thanks to all the contributors for shedding some light on the somewhat daunting world of tubes and Little Dots. I have been a relatively happy owner of HD650 / DT880 600 ohm / K702 ran through a Slee Solo Ultra Linear Amp directly from an Arcam CD73. I loved the laidback sound of the HD650 from the off although always found it a bit muffled. The DT880 brought a greater sound stage but the harshness of treble and the distant sound left a feeling of under-appreciation. The last addition of the K701 was an overall winner for me in terms of clarity, particularly for my main interest, classical music.
  
 This under-achievement for the Senns and the Beyers brought me back to Head-Fi 2-3 months ago and I started to look a little bit more into tube amps. Not so much for an upgrade, think more of a complementary side-step. Then came this thread and I took the plunge on the Little Dot Mark II early December. 
  
 In the last month, I replaced the stock power tubes with 6N6P's.
  
 Also bought up one pair of driver tubes for each of those for tube rolling initiation :
  
 GE JAN 5654W
 6HM5 Yougoslavia 
 Mullard 5654
 6J1P Voskhod
 Mullard EF95
  
 Needless to say I have properly fallen in love with my headphones, particularly with the DT880, but the HD650 is not far behind either. The combo DT880 + Mullard 5654 is to die for. I still get its great sound stage but the harshness has gone and the sound is so much closer and immediate, all topped up with greater details : for instance the fret work and instrument separation on Jordi Savall's Istanbul CD or Quatuor Mosaiques's Haydn String Quartets... or the now softer voices in Alessandrini's recording of Pergolesi's Stabat Mater. Some of my reference rock CD's for past headphone tests got such a new lease of life too !! (Clapton's unplugged, Jack Johnson's Brushfire Fairytales, Massive Attack 100th Window, Steely Dan's AJA etc...). Wow !
  
 When I finally "force" myself to remove the Mullards, I have been starting burning in the 6HM5 and the Voskhod with the HD650. The gain in clarity with those tubes is exactly what I searching for. Can't wait to hear what these tubes will bring in when fully burnt it. I am listening to Chris Rea's Dancing down the Stoney Road while typing this...pure bliss.
  
 So far, to accommodate the 300 ohm Senns and the 600 ohm DT880, I have set up the switches to Switch 1 On and Switch 2 Off. Serving both quite well. Don't want to make a habit of fiddling with the innards too much.  
  
 The Arcam CD player allows me to have both amps plugged in so I have been able to A/B while listening as well, just to make sure it was not just a new toy bias. The improvements go from extremely marginal to absolutely staggering, depending on the recordings. Not bad for the MKII at a quarter of the price. The Solo UL is pretty awesome in itself though, don't get me wrong. I have found myself many times forgetting about the ongoing A/B'ing halfway through, just getting pulled into the music, just to realise eventually the headphone was in the Solo UL. i think it is a nice testament to how good and complementary both amps will be. 
  
  
 Two quick question to wrap up please : 
  
 * Have you guys used http://tubes-store.com before ? no issues ? I am considering to order some 6N6P-I (or IR) and some Voskhod 6J1P-EV there. 
 * Would Elektro Harmonix 6H30PI Gold bring a substantial difference as power tubes ? Thought I'd ask, £50 a pair is still a bit steep for a tube beginner like me.   
  
 so yeah, otherwise...thank you very much !!


----------



## MIKELAP

papy said:


> Hello All,
> It has been quite a long time since i had lurked that regularly on Head-Fi but I had to post in this thread to pass my thanks to all the contributors for shedding some light on the somewhat daunting world of tubes and Little Dots. I have been a relatively happy owner of HD650 / DT880 600 ohm / K702 ran through a Slee Solo Ultra Linear Amp directly from an Arcam CD73. I loved the laidback sound of the HD650 from the off although always found it a bit muffled. The DT880 brought a greater sound stage but the harshness of treble and the distant sound left a feeling of under-appreciation. The last addition of the K701 was an overall winner for me in terms of clarity, particularly for my main interest, classical music.
> 
> This under-achievement for the Senns and the Beyers brought me back to Head-Fi 2-3 months ago and I started to look a little bit more into tube amps. Not so much for an upgrade, think more of a complementary side-step. Then came this thread and I took the plunge on the Little Dot Mark II early December.
> ...


 
 Yes ive bought from them before no problems to report.I have all of these power tubes and the one i liked the most was the 6N6P-IR and they usually cost around  $25.00 a pair cheap .Here's a review that was made awhile ago on the different power tubes p201 post# 3007. Have fun


----------



## bharat2580

papy said:


> Hello All,
> It has been quite a long time since i had lurked that regularly on Head-Fi but I had to post in this thread to pass my thanks to all the contributors for shedding some light on the somewhat daunting world of tubes and Little Dots. I have been a relatively happy owner of HD650 / DT880 600 ohm / K702 ran through a Slee Solo Ultra Linear Amp directly from an Arcam CD73. I loved the laidback sound of the HD650 from the off although always found it a bit muffled. The DT880 brought a greater sound stage but the harshness of treble and the distant sound left a feeling of under-appreciation. The last addition of the K701 was an overall winner for me in terms of clarity, particularly for my main interest, classical music.
> 
> This under-achievement for the Senns and the Beyers brought me back to Head-Fi 2-3 months ago and I started to look a little bit more into tube amps. Not so much for an upgrade, think more of a complementary side-step. Then came this thread and I took the plunge on the Little Dot Mark II early December.
> ...




I have the 6h30pi gold and to me they are good at heating up the unit but sound wise not so special 

The ir and i are great but depends on the drivers you use. And the dac and phones

With 6n6p-i i use the voskhods and the combination is great. Maybe a bit loose in the bottom end. But plenty of it. 

With the 6n6p-ir i use the mullards ef95 or 92 and they complement each other. The fast and tight ir's pair well with the smooth a bit lousy mullards overall good presentation, the mullards have lot of bass amaount and the ir's keep then tight and in check. 

I use the 30pi with both of them and they dont sound too different but they are more transparent then either of the other power tubes thats what i will say


----------



## bharat2580

papy said:


> Hello All,
> It has been quite a long time since i had lurked that regularly on Head-Fi but I had to post in this thread to pass my thanks to all the contributors for shedding some light on the somewhat daunting world of tubes and Little Dots. I have been a relatively happy owner of HD650 / DT880 600 ohm / K702 ran through a Slee Solo Ultra Linear Amp directly from an Arcam CD73. I loved the laidback sound of the HD650 from the off although always found it a bit muffled. The DT880 brought a greater sound stage but the harshness of treble and the distant sound left a feeling of under-appreciation. The last addition of the K701 was an overall winner for me in terms of clarity, particularly for my main interest, classical music.
> 
> This under-achievement for the Senns and the Beyers brought me back to Head-Fi 2-3 months ago and I started to look a little bit more into tube amps. Not so much for an upgrade, think more of a complementary side-step. Then came this thread and I took the plunge on the Little Dot Mark II early December.
> ...




Why you would replace the stock power tubes with the same ones ?? I think the unit comes with the 6n6p


----------



## Oskari

bharat2580 said:


> Why you would replace the stock power tubes with the same ones ?? I think the unit comes with the 6n6p




Chinese 6N6 --> Russian 6N6P?


----------



## papy

Thank you for the responses and the additional info/links.I think i will go through the whole thread again in the next few weeks, now that i have that little bit of use on the MKII and the added general understanding.
  
 I'll give a trial order on tube-stores for a pair of 6n6p-I and a pair of 6n6p-IR to start with, and a hanfdul of Voskhod. That will keep me entertained for a while. I'll take the plunge on the 6H30PI at another time.
  


> Chinese 6N6 --> Russian 6N6P?


 
  

 That's what I have done.


----------



## bharat2580

oskari said:


> Chinese 6N6 --> Russian 6N6P?


 

 mine had russian as far as i remember


----------



## GnuB

And so it begins.  I am a little late to the party and the thread but rolled in my first tubes today (EH 6H30Pi) and have several drivers and power tubes on order based on recommendations and reviews.
  
 I have had headphones and amps for several years, and while enjoyable, never thought anything was extraordinary until receiving the MK III.  I listened daily at work to my Corda Move with either ER4P's or Triple Fi 10's and there were a few "Wow" moments but mostly were just average to my ears.  Same at home with the Aune and DT880 / Senn 580's. I am experiencing my music with new ears with the MK III, revisiting my favorite tracks.  I am looking forward to investigating new dimensions with the tubes that are coming.  However, it is all about the enjoyment of the music and how the equipment can enhance the experience and not about endless experimentation for me.   I fell into that trap once before.  I once had a fairly sophisticated stereo setup with tube pre amp and amp and one night a friend of mine and I were comparatively listening to the same album played on the same model of turntable with the same model cartridge with different tone-arms thinking we seriously heard a difference.  While that foolishness may have been interesting from an experimental point of view, it had very little impact on the listening pleasure of the music itself.  So, I will not succumb to FOMO disease (Fear Of Missing Out).  At some point, soon I hope, that I will achieve the right combination of tubes in the MK III and be done, forever satisfied.  
  
 Sure, I believe that...  Really...


----------



## papy

I have just purchased a brand new pair of the (now "old") HD800. If you have used or are using the HD800 with the MKII, which types of driver tubes have given you the most rewarding results please ? thank you.


----------



## northendjazz

A Question for those using a mkiii or mkiv as a preamp, does the gain setting effect output as a preamp?  I just set the mkiv volume to normal level for my dt880's and adjusted the volume on the new Beresford Capella and all is fine infact rather good.


----------



## TrollDragon

northendjazz said:


> A Question for those using a mkiii or mkiv as a preamp, does the gain setting effect output as a preamp?  I just set the mkiv volume to normal level for my dt880's and adjusted the volume on the new Beresford Capella and all is fine infact rather good.


 

 Yes it does, the Line Out and Headphone jack have the exact same internal connection on the Little Dot MK III & IV.


----------



## WilliamLeonhart

My Voshkod 6ZH1P-EV has "07-81" marking... Don't know if it was for Cold War rockets or not. I'm rather unimpressed with it. Nothing special at all


----------



## Opeth1966

Joined last week after lurking about for a year or so. I have been running a little dot 3 with stock tubes Sennheiser Momentum 1·0 and a Quad Cd99p with transport upgrade and have just started my tube rolling adventures.
To be honest i was quite happy with the set up and was thinking of headphone upgrade.
However after reading the copious threads here I thought why not buy some tubes and see how that goes.
So spent £50 in total £21 for a matched pair of EF95 Mullard and £29·95 on 2x 6n6p Novosibirsk 2x 6j1p-ev Voskhod rockets both matched pairs. From 2 different dealers on ebay which I researched from the advice given here.
The mullard turned up the very next day in original boxes and shield stamped.
So out come the stock tubes in go the Mullards. Still have stock power tubes in.
Click the switch and off we go.
The tracks I listened to test were Opeth Ghost of perdition. Patti Rothberg Flicker and Ian Brown F.E.A.R.
Well straight from the off the harsh brightness of the stock tubes has dissappeared completely and vocals across the board are improved with female vocals sublime. Even the hard vocals on the Opeth track which sounded indecipherable in places have been smoothed out. There is a warmth and openness which just was not there. Rim shots and bass drum kicks are superb. This has got to be the best value for money upgrade ever £21!! 
I've been running them for a week now and they just get better. Soundstage is good on all tracks. However the do seem a bit laid back for the Opeth track but are superb on the Patti Rothberg. The Ian Brown track bubbles along.
The acoustic and harmonic parts of the Opeth track are open and warm the middle section with the chugging guitars made my hairs stand on end. 
All in all a great investment. The other tubes turned up a day later but are still in the box. I'll be trying the power tubes with the Mullards next an I'll post my findings.
Overall this felt like a vety decent upgrade.However as I listen mainly to metal there just seemed to be something lacking. But for folk female vocal these are superb.
At the end of the day my listening experience has been transformed and that's what it's all about. All I've got to do now is find the right headphone as good as the momentum are they are better suited to mobile use and they do become uncomfortable after a couple of albums listening a problem I believe they have resolved with the 2·0·
Hope this has been of use to someone if so let me know.
Next post next week. 
Happy listening.


----------



## Johnnysound

gnub said:


> And so it begins.  I am a little late to the party and the thread but rolled in my first tubes today (EH 6H30Pi) and have several drivers and power tubes on order based on recommendations and reviews.
> 
> I have had headphones and amps for several years, and while enjoyable, never thought anything was extraordinary until receiving the MK III.  I listened daily at work to my Corda Move with either ER4P's or Triple Fi 10's and there were a few "Wow" moments but mostly were just average to my ears.  Same at home with the Aune and DT880 / Senn 580's. I am experiencing my music with new ears with the MK III, revisiting my favorite tracks.  I am looking forward to investigating new dimensions with the tubes that are coming.  However, it is all about the enjoyment of the music and how the equipment can enhance the experience and not about endless experimentation for me.   I fell into that trap once before.  I once had a fairly sophisticated stereo setup with tube pre amp and amp and one night a friend of mine and I were comparatively listening to the same album played on the same model of turntable with the same model cartridge with different tone-arms thinking we seriously heard a difference.  While that foolishness may have been interesting from an experimental point of view, it had very little impact on the listening pleasure of the music itself.  So, I will not succumb to FOMO disease (Fear Of Missing Out).  At some point, soon I hope, that I will achieve the right combination of tubes in the MK III and be done, forever satisfied.
> 
> Sure, I believe that...  Really...


 
 Hi Gnub,  I started with the MKIII some 3 years ago and went all the way up to "ultimate" mods following the advice of the truly experts here in this thread.  Trust them, they will show you the way to a great ride, believe me.  I like your post, because I felt exactly the same when I listened to this little amp for the first time. And as good as it was  with headphones, its performance  as a preamp,  in its standard form  driving a serious and quite good setup, just throw me off base.  My reference ss preamp was perhaps more detailed and had stronger bass,  but  was kind of lifeless against the musical and enjoyable MKIII.  And this was in standard form,   tube mods will transform the MKIII into another thing, it is designed to be modded,  accepts a lot of variants,  and it can reach extraordinary sound quality. And I mean _really _ high quality.   IMHO, for the price will beat anything out there.  
  
  But I do not want to go ahead of things, for the moment the standard drivers have to go out first.    The Yugo 6HM5 are great F95 drop in replacements, but I liked the Voshkods a lot also. Great sounding.   However, my personal one was the Tung-Sol 6485, an EF92   type (requires changing internal pins)  with a lively, clear, punchy and dynamic sound I enjoyed a lot.  All this with the standard russian power tubes which I consider  excellent...


----------



## GnuB

johnnysound said:


> ... (snip) ...
> But I do not want to go ahead of things, for the moment the standard drivers have to go out first.    The Yugo 6HM5 are great F95 drop in replacements, but I liked the Voshkods a lot also. Great sounding.   However, my personal one was the Tung-Sol 6485, an EF92   type (requires changing internal pins)  with a lively, clear, punchy and dynamic sound I enjoyed a lot.  All this with the standard russian power tubes which I consider  excellent...


 
  
 Thanks for the encouragement.  I have the 6HM5 / 6N6P-IR combination in use now and am getting to know them but the initial impressions are very positive and the best I have tried so far (soundstage, detail and transparency).  The plan is to live with each combination for a while rather than swap-swap-swap. It takes time for me to recognize real improvements (non-placebo) but can quickly recognize downgrades.  I will keep an eye out for a deal on a pair of the Tung-Sol 6485 tubes and give them a try.  In the meanwhile, I am buying cd's of music that I used to have on vinyl and some new releases from favorite musicians.  It is a fun ride.


----------



## GnuB

This Tube Table: http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/8760#post_11155053
  
 Shows the 6N23P in both the Power and Driver positions with no adapter required.  It is a 9 pin tube so it should require an adapter in the driver position if it would work at all.  Is there an adapter for it and what would be the expected result of it as a driver?
  
 This tube works in the Aune T1 which I am buying from another Head-fier.  I am trying to anticipate a good combination of tubes in the Aune as the DAC and the MK III as the amp.


----------



## gibosi

gnub said:


> This Tube Table: http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/8760#post_11155053
> 
> Shows the 6N23P in both the Power and Driver positions with no adapter required.  It is a 9 pin tube so it should require an adapter in the driver position if it would work at all.  Is there an adapter for it and what would be the expected result of it as a driver?
> 
> This tube works in the Aune T1 which I am buying from another Head-fier.  I am trying to anticipate a good combination of tubes in the Aune as the DAC and the MK III as the amp.


 
  
 The "adapter" to use the 6N23P or other 9-pin dual triodes as drivers in the LD typically consists of an external 9-pin breadboard socket and two 7-pin test sockets. It is quite crude and ugly, but it works fine. And if one wants to run tubes drawing more than 0.45A and/or 12V tubes, an external heater power supply can be added.


----------



## Opeth1966

Hello again as promised just a bit of an update for anyone who is intersted.Following on from my last post. I had just put the Mullard EF95 into my little dot 3 and was running with standard power tubes and i have to say i am well pleased with the results. As the tubes settled in the sound became more open and smooth as i tried them with various female vocalists. Fiona Apple/Beth Orton/ P.J.Harvey/Beth Gibbons/Catherine Feeny all sounding excellent. Beth Gibbons Rusting Man sounding particularly haunting in parts and i found that these tubes were particularly suited to softer passages of music { this is only my opinion} Also the acoustic and piano parts of various Opeth tracks becoming more atmospheric the piano passage at the end of Leper Affinity absolutely sublime i never knew silence could sound so good. So all in all a great upgrade.
 So now to the stock power tubes come out  and in go the Russian 6n6p Novosibirsk. 
 I have to say  that the initial impact was not what i expected which was probably over expectation from the driver tube change and im struggeling to hear any vast difference there are subtle changes but nothing drastic. However after the recommended burn in of around 20-30 hours from the tube supplier its a different story.
 The whole sound has been tightened up and the same 3 test  tracks take on another life the smooth openness of the Mullard tubes has taken on another level soundstage is great and the bass is smooth its as though the music has been given room to breath. My only criticism is that for  me there is still that lack of punch that im looking for in the midrange on heavier tracks especially guitar but its still a whole lot better than the standard stock tubes. Highs are also great.
 I then put on Made in Japan  the remixed edition from last year and im blown away i listened to the 3rd night  strange kind of woman/lazy/space truckin and i may as well have been there in 1972 there is a passage in space trucking where  you can hear 2  japanese guys having a conversation incredible. To me its a perfect representation of what went on over those 3 nights. I have every release of this album that there is to have and have compared them all. 
 All in all im really pleased with the upgrades and im going to run these for another week. I have to say im looking forward to changeing the Mullard tubes for the voskhod rockets to see what  they can bring.
 My next dilemma is what to do about my headphones momentum 1.0 i just feel that  they need to go back out on the street for mobile listening. Im still not sure what to go for and by that i mean i listen to music in the living room where the wife  watches tv and im looking to go for open back headphones that im told leak sound so its not just about my listening pleasure but also trying not to get on the wives nerves. Anyone know where i can test some AKG/Sennhiser/Grados for sound quality and leakage Im in Caterham Surrey. UK
 As always this is only my humble opinion based on my ears. But if anyone out there is thinking of upgrading equipment try upgrading your tubes for me pound for pound its been the best upgrade ive done and there is lots of great advice on this site and i have to say its been an eye opener or should i say ear.
 Happy listening. Hope this has been of use to someone. Next post in a week or so to see how the russian rockets fair.


----------



## bjj51

I just ordered these from eBay:

http://m.ebay.com/itm/251818022323

These are the 6n6p ir tubes that people like right? I just realized the auction didn't have the ir suffix and now I'm worried..


----------



## Opeth1966

Yeah theses are the tubes everybody seem to recommend. I've just upgraded to these. (See my last post). But as always with any of this stuff listen to your ears it's all subjective. Happy listening.


----------



## MIKELAP

bjj51 said:


> I just ordered these from eBay:
> 
> http://m.ebay.com/itm/251818022323
> 
> These are the 6n6p ir tubes that people like right? I just realized the auction didn't have the ir suffix and now I'm worried..


 
 Those are the 6N6P tubes these are the 6N6P-IR you are looking for                                              http://www.ebay.com/itm/171310973012?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT


----------



## Opeth1966

bjj51 said:


> I just ordered these from eBay:
> 
> http://m.ebay.com/itm/251818022323
> 
> These are the 6n6p ir tubes that people like right? I just realized the auction didn't have the ir suffix and now I'm worried..


----------



## Opeth1966

mikelap said:


> Those are the 6N6P tubes these are the 6N6P-IR you are looking for                                              http://www.ebay.com/itm/171310973012?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT


Yeah theses are the right tubes I've just put theses in my little dot 3.See the quote I posted yesterday for my findings


----------



## bjj51

Darn, so the 6n6p's are inferior to the 6n6p-ir's? What is the difference exactly?


----------



## MIKELAP

bjj51 said:


> Darn, so the 6n6p's are inferior to the 6n6p-ir's? What is the difference exactly


 
 For one they last longer and were a favorite of this thread for differences here are reviews of the different power tubes page 201 #3007


----------



## lglions

mikelap said:


> For one they last longer and were a favorite of this thread for differences here are reviews of the different power tubes page 201 #3007


 
 I have 6N6P, 6N6P-I and 6N6P-IR. I can attest that "IR" version is sonically superior to the other two. For me it's better refined bass and wider soundstage.


----------



## bjj51

Thanks for the clarification guys, I managed to cancel the eBay order in time thankfully. Now I have the 6n6p-ir that mikelap linked on the way.

On a side note, I also got the Yugoslavia 6hm5 driver tubes and they sound fantastic. Thanks for the help, this thread is a great resource for tube rolling newcomers like myself.


----------



## SpecChum

Must admit I was pretty sceptical how much a tube transplant (TM) could alter the sound of my hybrid Little Dot I+.
  
 My *6ZH1P-EV* came in the post today and I've just put them in and left them to warm up for an hour and pressed play...
  
 ...wow
  
 It's almost like someone hit the bass boost button but still with nice sparkly highs too, mids are also non shrill like they were with the default tubes - when Whitney hit those high notes it sometimes became uncomfortable now it's silky smooth.
  
 My only complaint is the mids now sound ever so slightly thick, kinda heavy but that's maybe cos I used to the bright mids of the Chinese tubes.
  
 Overall, I'm very impressed!


----------



## MIKELAP

specchum said:


> Must admit I was pretty sceptical how much a tube transplant (TM) could alter the sound of my hybrid Little Dot I+.
> 
> My *6ZH1P-EV* came in the post today and I've just put them in and left them to warm up for an hour and pressed play...
> 
> ...


 
 Some have reported very long burnin time 100 hours + .Use the (Search this thread ) function atop the page it is very useful


----------



## eschell27

Hello, fairly new to the tube amp & little dot world... incredibly happy thus far, grabbed an MK IV se a few weeks ago and this things sounds great with my DT990 600 ohm and K7xx. One of the reasons i wanted to try out the world of tubes is the opportunity for tweaking sound by rolling tubes like most people probably and been doing a little research but decided to also put out a request for some recommendations for this amp with these two sets of cans. Just looking for suggestions and why you like the combo with these specific cans.
  
 Thanks in advance for any tips i may get and all the ones already in this thread....Little Dot so far is turning out to be as great as most claim they are, and i love it... next is to replace my dac (aune x1s, got it as my first dac/amp combo and quickly started upgrading hah, i'm hooked!) with an audio-gd dac-19 10th anniversary. (also looking for suggestions on dacs but i know thats not what this thread is for)


----------



## Centropolis

I've been looking online for tubes to upgrade the stock LD MKii.
  
 While I was able to find some of the recommended ones to replace my stock 6J1s, I am not able to determine whether the ones I am looking at indeed the same ones recommended.  It seems there are different versions variations.  Different years...and even look different.
  
 I've read certain years of Mullards are better than others.  Being a newbie at tubes, should I be worry much about this or any of the recommended ones will vastly improve the sound without thinking too much about the year?  Sorry about the newbie question.


----------



## WilliamLeonhart

eschell27 said:


> Hello, fairly new to the tube amp & little dot world... incredibly happy thus far, grabbed an MK IV se a few weeks ago and this things sounds great with my DT990 600 ohm and K7xx. One of the reasons i wanted to try out the world of tubes is the opportunity for tweaking sound by rolling tubes like most people probably and been doing a little research but decided to also put out a request for some recommendations for this amp with these two sets of cans. Just looking for suggestions and why you like the combo with these specific cans.
> 
> Thanks in advance for any tips i may get and all the ones already in this thread....Little Dot so far is turning out to be as great as most claim they are, and i love it... next is to replace my dac (aune x1s, got it as my first dac/amp combo and quickly started upgrading hah, i'm hooked!) with an audio-gd dac-19 10th anniversary. (also looking for suggestions on dacs but i know thats not what this thread is for)


I'm having the odac, but I'm not sure how much different it is from the aune xs. Aune do quite a good job with their entry level range.


----------



## WilliamLeonhart

There's plenty of choices that are cheap and sound nice. I recommend the Yugos 6hm5. I like my Mullard too but it's not true to say one brand of tubes is better than others. One pair of tubes may do the things that others do better, but I don't think we should compare a mid-centric to a bass-centric tube. 

And it's true different years make different sound. Best thing you can do is do some research on google and ask the seller if the tubes they sell are the same as what you want. 





centropolis said:


> I've been looking online for tubes to upgrade the stock LD MKii.
> 
> While I was able to find some of the recommended ones to replace my stock 6J1s, I am not able to determine whether the ones I am looking at indeed the same ones recommended.  It seems there are different versions variations.  Different years...and even look different.
> 
> I've read certain years of Mullards are better than others.  Being a newbie at tubes, should I be worry much about this or any of the recommended ones will vastly improve the sound without thinking too much about the year?  Sorry about the newbie question.


----------



## Centropolis

williamleonhart said:


> There's plenty of choices that are cheap and sound nice. I recommend the Yugos 6hm5. I like my Mullard too but it's not true to say one brand of tubes is better than others. One pair of tubes may do the things that others do better, but I don't think we should compare a mid-centric to a bass-centric tube.
> 
> And it's true different years make different sound. Best thing you can do is do some research on google and ask the seller if the tubes they sell are the same as what you want.


 
  
 Thanks.  It's sometimes funny to think that I spent $100 on the MKii used and now will spend another $100 or so just on upgrading the tubes.   
  
 I've looked up the Yugos 6HM5 and it says they are EF86?  So will I need an adaptor to use these on my MKii? 
  
 Another question, would it be stupid to upgrade just the driver tubes and not the power tubes at the same time to save some money?  Or it would just defeat the whole purpose?  The 6N6P Russian power tubes are even more expensive than the smaller ones.


----------



## MIKELAP

centropolis said:


> williamleonhart said:
> 
> 
> > There's plenty of choices that are cheap and sound nice. I recommend the Yugos 6hm5. I like my Mullard too but it's not true to say one brand of tubes is better than others. One pair of tubes may do the things that others do better, but I don't think we should compare a mid-centric to a bass-centric tube.
> ...


 
 The 6HM5 is a EF95 type tube check out page 77 of this thread and see for yourself  ive tried most of all the tubes in this thread that are plug & play or use an adapter it all depends what is your goal is it to explore the different tube sounds or get the best sounding tubes right away .One of the best power tubes we found here is the 6N6P-IR  they are around $30.00 a pair if you want to check out power tube reviews go here page 201 post #3007


----------



## Centropolis

mikelap said:


> The 6HM5 is a EF95 type tube check out page 77 of this thread and see for yourself  ive tried most of all the tubes in this thread that are plug & play or use an adapter it all depends what is your goal is it to explore the different tube sounds or get the best sounding tubes right away .One of the best power tubes we found here is the 6N6P-IR  they are around $30.00 a pair if you want to check out power tube reviews go here page 201 post #3007


 
  
 Thanks for the info.
  
 Last question for now, I've seen a lot of eBay listings that says "Matched codes" instead of just "matched".  I assume matched codes does not mean they actually measured to match but just that they were made around the same time?


----------



## MIKELAP

centropolis said:


> mikelap said:
> 
> 
> > The 6HM5 is a EF95 type tube check out page 77 of this thread and see for yourself  ive tried most of all the tubes in this thread that are plug & play or use an adapter it all depends what is your goal is it to explore the different tube sounds or get the best sounding tubes right away .One of the best power tubes we found here is the 6N6P-IR  they are around $30.00 a pair if you want to check out power tube reviews go here page 201 post #3007
> ...


 
 Usually when they say ¨matched¨it means that they measure within 10% of each other ¨matched codes¨ means that they come from same place and made at same time . First of all our amps dont need to have matched pairs that's a scam to make more money of you .When i buy a pair of tubes they have to be atleast same brand and same year or same structure .


----------



## Centropolis

mikelap said:


> Usually when they say ¨matched¨it means that they measure within 10% of each other ¨matched codes¨ means that they come from same place and made at same time . First of all our amps dont need to have matched pairs that's a scam to make more money of you .When i buy a pair of tubes they have to be atleast same brand and same year or same structure .


 
  
 Thanks for the information and for the patience with the noob.  
  
 I've looked around online in the past 2 hours or so trying to find a pair of the recommended driver tubes.  They seem to be a lot more money than what other people are buying them for.  I've looked at Voshkod 6ZH1P-EV, Mullard M8100 / CV4010 and Tung-Sol 6AK5.  I can't seem to find a pair that sells for anything less than almost CAD$45 shipped.  That's a lot of money.  I think I am looking at the wrong listings.


----------



## MIKELAP

centropolis said:


> mikelap said:
> 
> 
> > Usually when they say ¨matched¨it means that they measure within 10% of each other ¨matched codes¨ means that they come from same place and made at same time . First of all our amps dont need to have matched pairs that's a scam to make more money of you .When i buy a pair of tubes they have to be atleast same brand and same year or same structure .
> ...


 
  if your like me and live in Canada these days with our buck  its very expensive ,everything is in U.S. dollars. To be honest ive cut down alot on the tube buying .the link below is not to bad of a price for 4 tubes .Not many M8100 .Half the fun is the hunt lol.Have i mentionned page 77 of this thread the better tubes are towards the end  .A feature that is very helpful is the SEARCH THIS THREAD function atop the page i use it all the time when lm looking for infos very useful .One thing when ordering from Russian to Canada it use to take a month for order to get here hope your patient .Have fun.                           http://www.ebay.com/itm/MATCHED-OUAD-6J1P-EV-6ZH1P-EV-EF95-6F32-6AK7-Little-Dot-Pan-Am-Headphone-/151960252626?hash=item23618970d2:g:96cAAOSwUdlWfBhG


----------



## Centropolis

mikelap said:


> if your like me and live in Canada these days with our buck  its very expensive ,everything is in U.S. dollars. To be honest ive cut down alot on the tube buying .the link below is not to bad of a price for 4 tubes .Not many M8100 .Half the fun is the hunt lol.Have i mentionned page 77 of this thread the better tubes are towards the end  .A feature that is very helpful is the SEARCH THIS THREAD function atop the page i use it all the time when lm looking for infos very useful .One thing when ordering from Russian to Canada it use to take a month for order to get here hope your patient .Have fun.                           http://www.ebay.com/itm/MATCHED-OUAD-6J1P-EV-6ZH1P-EV-EF95-6F32-6AK7-Little-Dot-Pan-Am-Headphone-/151960252626?hash=item23618970d2:g:96cAAOSwUdlWfBhG


 
 I really do wonder if people do swap the tubes constantly when they listen to different types of music.  Although it's not that hard to swap the tubes, I don't imagine myself listening to Dr. Dre and then switch tubes when I put on Beethoven string quartets.  Lol  I am more likely to go from Ultrasone 900 Pro to my DT880 in this scenario.
  
 Thanks again for your help.  The quad you linked looks like a good price for 4.  Although I do wonder how they are different than these to warrant the price diference.  http://www.ebay.com/itm/301050977487?_trksid=p2060353.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT


----------



## MIKELAP

centropolis said:


> mikelap said:
> 
> 
> > if your like me and live in Canada these days with our buck  its very expensive ,everything is in U.S. dollars. To be honest ive cut down alot on the tube buying .the link below is not to bad of a price for 4 tubes .Not many M8100 .Half the fun is the hunt lol.Have i mentionned page 77 of this thread the better tubes are towards the end  .A feature that is very helpful is the SEARCH THIS THREAD function atop the page i use it all the time when lm looking for infos very useful .One thing when ordering from Russian to Canada it use to take a month for order to get here hope your patient .Have fun.                           http://www.ebay.com/itm/MATCHED-OUAD-6J1P-EV-6ZH1P-EV-EF95-6F32-6AK7-Little-Dot-Pan-Am-Headphone-/151960252626?hash=item23618970d2:g:96cAAOSwUdlWfBhG
> ...


 
 lol Its funny you ask because when i started in tubes the first pair i bought was from them yenaudio so back then i wasnt lucky nobody ever told me that this seller was expensive i learned on my own but i guess today is your lucky day .The main thing is to be patient and do your homework and you wont get screwed


----------



## GnuB

Here is another source:
  
 http://tubes-store.com/advanced_search_result.php?keywords=6J1P-EV+%2F+6AK5+%2F+EF95+%2F+6F32+Voskhod+tube
  
 I ordered these.  There is a minimum order so I ordered 2 of the 6n6P tubes.  
  
 4 x6J1P-EV / 6AK5 / EF95 / 6F32 Voskhod tube*$*6.00
 2 x6N6P / ECC99 / E182CC tube*$*6.00
  

Sub-Total:*$*12.00Shipping & Handling:*$*8.00Total:*$20.00*
  
 They also have the highly recommended 6N6P-IR
  
 http://tubes-store.com/advanced_search_result.php?keywords=6N6P-IR+%2F+ECC99+%2F+E182CC+high-durable+tube


----------



## Centropolis

Thanks for the links!  So this site doesn't have to option to select matched pairs, unlike others.  Some people mentioned that tubes being matched is little pointless when it's taken to the extreme.  When you bought 4 of these 6J1P-EV, you ddin't care if they were matched (atleast to a certain extend)?  Just wondering people's opinions.  I've read some that says it's important even for longevity of the tubes, some says it doesn't matter at all.
 
For the power tubes, I already bid on and won a pair of Russian 6N6P a few days ago.  I didn't read about the 6N6P-IR until afterwards.  Actually, I am not even sure if the 6N6P-IR works with MKii.


----------



## GnuB

centropolis said:


> Thanks for the links!  So this site doesn't have to option to select matched pairs, unlike others.  *Some people mentioned that tubes being matched is little pointless when it's taken to the extreme*.  When you bought 4 of these 6J1P-EV, you ddin't care if they were matched (atleast to a certain extend)?  Just wondering people's opinions.  I've read some that says it's important even for longevity of the tubes, some says it doesn't matter at all.
> 
> For the power tubes, I already bid on and won a pair of Russian 6N6P a few days ago.  I didn't read about the 6N6P-IR until afterwards.  Actually, I am not even sure if the 6N6P-IR works with MKii. 
  
 I can't answer that from an expert's point of view, only from a practical point of view.  I have a matched pair of Electro Harmonix power tubes and two different sets of unmatched Russian power tubes and while there are differences in sound signature that I attribute to the different tube types, I cannot discern any difference between matched and unmatched.  I don't detect channel imbalance or frequency differences between channels so in my experience I would not hesitate to buy unmatched tubes particularly if there is a significant price difference.  BTW. I ordered 4 6J1P-EV tubes from the Tube Store and they sent 6 so there were extras if I were to happen to get a bad tube.  I am listening to the cheapest pair of power tubes (6N6P at $3.00 each vs $50 for the matched pair of Electro Harmonix tubes) while I let them burn in and would now have a hard time justifying the added expense of the EH tubes if I hadn't bought them already.


----------



## Opeth1966

centropolis said:


> Thanks.  It's sometimes funny to think that I spent $100 on the MKii used and now will spend another $100 or so just on upgrading the tubes.
> 
> I've looked up the Yugos 6HM5 and it says they are EF86?  So will I need an adaptor to use these on my MKii?
> 
> Another question, would it be stupid to upgrade just the driver tubes and not the power tubes at the same time to save some money?  Or it would just defeat the whole purpose?  The 6N6P Russian power tubes are even more expensive than the smaller ones.


 
 I too have just started my tube rolling journey with my little dot 3 which i have run on stock tubes for a year. Im in the UK so pricing is different i spent £50 on 6 tubes a set of Mullard EF95 and a set of 4 Russian tubes  2 x 6n6p Novosibirsk and 6jip Voskhod rockets {see previous posts}. I changed just driver tubes first with the Mullard and run that for a while then changed the power tubes and run those with the Mullards then changed  the Mullards with the Russian rockets. Im going to do a post on that at the end of this week. What i can say is your comment regarding changing tubes for different types of music made me smile as thats exactly what ive been doing for the past week. Both sets of driver tubes are excellent in their own way as as always it depends on what you are looking for. I personally think that the Mullard give a more smoother open sound and are fantastic on vocals especially female vocal and quiter passages of music. The rockets for me bring the mid and bass up more. I listen to mainly metal but have a wide range of musical taste. So ive spent the last week changing the Mullards and Rockets over on a daily basis. Looks like this tube rolling has opened up a whole can of {enjoyable} worms. As always this is only my humble opinion and its mt ears and taste but what i can say is that the music i listen too has been given a new lease of life. Happy rolling and listening.


----------



## WilliamLeonhart

Not quite constantly since you'd have to wair for a few minutes before swapping out the tubes (wait for them to get cool). But it's true that I don't swap tubes in a single listening session. I just decide what kind of music I'd like to listem to today and put in the appropriate tubes. Sometimes it's also ok to play the song that don't go well with the current tubes as well. I just appreciate that different tubes give different sounds and after all it feels great to experiment. 





centropolis said:


> I really do wonder if people do swap the tubes constantly when they listen to different types of music.  Although it's not that hard to swap the tubes, I don't imagine myself listening to Dr. Dre and then switch tubes when I put on Beethoven string quartets.  Lol  I am more likely to go from Ultrasone 900 Pro to my DT880 in this scenario.
> 
> Thanks again for your help.  The quad you linked looks like a good price for 4.  Although I do wonder how they are different than these to warrant the price diference.  http://www.ebay.com/itm/301050977487?_trksid=p2060353.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT


----------



## buldogge

centropolis said:


> Thanks for the information and for the patience with the noob.
> 
> I've looked around online in the past 2 hours or so trying to find a pair of the recommended driver tubes.  They seem to be a lot more money than what other people are buying them for.  I've looked at Voshkod 6ZH1P-EV, Mullard M8100 / CV4010 and Tung-Sol 6AK5.  I can't seem to find a pair that sells for anything less than almost CAD$45 shipped.  That's a lot of money.  I think I am looking at the wrong listings.


 

 Centropolis...I have what you need, if you like.  I made my way thru al the tubes mentioned in this thread and have a lot of spares.  The pictured GE 6HQ5s are very similar to the Yugos and simply sound wonderful, as do the Mullards...alternatively, I have a lot of other options in the 2nd pic.
  
 LMK
 -Mark in St. Louis


----------



## Centropolis

buldogge said:


> Centropolis...I have what you need, if you like.  I made my way thru al the tubes mentioned in this thread and have a lot of spares.  The pictured GE 6HQ5s are very similar to the Yugos and simply sound wonderful, as do the Mullards...alternatively, I have a lot of other options in the 2nd pic.
> 
> LMK
> -Mark in St. Louis


 
  
 Thanks!  I've sent you a PM on this.
  
 I kind of regretting buying those 6N6P from eBay.  Althuogh I am sure they are better than my stock Chinese 6n6, I think I overpaid.


----------



## TrollDragon

centropolis said:


> Thanks for the links!  So this site doesn't have to option to select matched pairs, unlike others.  Some people mentioned that tubes being matched is little pointless when it's taken to the extreme.  When you bought 4 of these 6J1P-EV, you ddin't care if they were matched (atleast to a certain extend)?  Just wondering people's opinions.  I've read some that says it's important even for longevity of the tubes, some says it doesn't matter at all.
> 
> For the power tubes, I already bid on and won a pair of Russian 6N6P a few days ago.  I didn't read about the 6N6P-IR until afterwards.  Actually, I am not even sure if the 6N6P-IR works with MKii. 
 The old question of matched tubes...





  
 First off the Little Dot Amplifiers MK II/III/IV etc are Preamps, they have no output connecting to speakers and do not require Power Tubes. The Headphone Jack on the front of the case is the exact same connection as the Line Out RCA jacks in the rear, they both internally connect to the same point on the board.
  
 Matched pairs of power tubes are sold for amplifiers whose output circuitry is a Class AB Push Pull, each tube in that setup requires matching so that one tube doesn't draw more current than the other. Matched pairs are not required in that type of amplifier if there is a bias adjustment on the board for each tube, if not, then matched pairs are a must.
  
*All this has absolutely nothing to do with the LD MK II/III/IV, they do NOT require anything to be matched, it is a way for vendors to get more money from uninformed tube buyers.*
  
 If I go looking for a pair of 6HM5's I am not really worried that the vendor lists them as *MATCHED PAIR* in his listing as long as the price of the tubes do not reflect an increase for the addition of those words to the ad.

 Here is the seller that most everyone has bought their 6HM5's from, no mention of matched pairs in his Ad.
 http://www.ebay.ca/itm/6HM5-6HA5-EC900-export-quality-audio-triode-tube-NOS-FREE-SHIPPING-/300879467071
  
 And another that is selling the exact same tube for more, notice the MATCHED PAIR in the Ad.
 http://www.ebay.ca/itm/6HM5-EC900-EI-Yugoslavia-NOS-matched-pair-Little-Dot-Amp-FREE-SHIPPING-WW-/251691711374
  
 Not really a big difference in value between the two vendors and you could make an offer to each one to get a lower price. These 6HM5's were made by the 100K's back in the day and are not rare by any means, when you start getting into rare tubes then you really need to know what you are buying.
  
 All of the tubes you can Plug and Play like the ones from page 77 are very reasonable in price and readily available from eBay.  Once you get into non standard tubes in a modified LD, they can get expensive very quickly. Since these tubes are usually rare and come with a higher demand, you really need to know what you are looking at and what you are buying.


----------



## Centropolis

trolldragon said:


> The old question of matched tubes...
> 
> 
> 
> ...


 
  
 Thanks.  I will pay less attention to the word "Matched" going forward.


----------



## TrollDragon

centropolis said:


> Thanks.  I will pay less attention to the word "Matched" going forward.


 
 The offer from @buldogge sound to be a really sweet deal on getting great tubes that are plug and play, a really good place to start IMHO.


----------



## Rossliew

Using some RCA 6BZ7s as power tubes with WE403As as input tubes - great mids, strong punchy bass but may be slightly sibilant with female vocals.
  
 Good combo though


----------



## Kenjiwing

Hey guys really stupid question
  
 I ordered  6n6p-ir and 2 6HM5 tubes which slots will they go in on my LDMK3?


----------



## MIKELAP

kenjiwing said:


> Hey guys really stupid question
> 
> I ordered  6n6p-ir and 2 6HM5 tubes which slots will they go in on my LDMK3?


 
 6HM5 ARE DRIVERS (FRONT) 6N6P-IR are power tubes (back). By the way there's no stupid question i asked the same one when i started


----------



## bharat2580

kenjiwing said:


> Hey guys really stupid question
> 
> I ordered  6n6p-ir and 2 6HM5 tubes which slots will they go in on my LDMK3?


 

 even if you want you can't swap the slots, so don't worry its different pin configurations,


----------



## bharat2580

on the mkIV se i actually prefer the 30pi then the ir . they sound better and i am using the voskhods for drivers good dynamic configuration.


----------



## wwmhf

Thanks for clarifying the "matched" idea for this kind of amps.


----------



## wwmhf

Two types of 6ZH1P-EV: 
  
 I recently bought a Little Dot IV SE amp and started the tube rolling entertainment. Following your suggestions, I have bought the following driver tubes: tall 6HM5 and 6ZH1P-EV. They all sound acceptable in their initial services, but I have a couple surprises: 
  
 1. The 6HM5s show firework in the first second or so when the amp is turned on, never knew any tube could do that.
 2. I bought 6ZH1P-EVs from two sellers on Ebay and 2 distinct types of them showed up. The the first type has the conventional smooth glass tube, but the second type has 3 vertical notches long the tube and they are from 
  
  
 http://www.ebay.com/itm/182003142279?_trksid=p2060353.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT
  
 The first type with the conventional smooth glass tube performed very well in their early service. Those with notches on glass tubes sounded bad in their initial service, but they sounded better later. 
  
 I think those notches can enhance the integrity and reduce the vibration (if any) of the tube. 
  
 I like those 6ZH1P-EVs without notches.
  
 Have you used these two type 6ZH1P-EVs? Your impressions?


----------



## WilliamLeonhart

wwmhf said:


> Two types of 6ZH1P-EV:
> 
> I recently bought a Little Dot IV SE amp and started the tube rolling entertainment. Following your suggestions, I have bought the following driver tubes: tall 6HM5 and 6ZH1P-EV. They all sound acceptable in their initial services, but I have a couple surprises:
> 
> ...


 
 I have the one with notches unfortunately and they sound rather dull. There's definitely a bump in the bass but it's nothing to the level of Mullards. It feels like the bass is smoother than usual.


----------



## Rossliew

I've been using rca 6BZ7 as power with RT5654 as drivers - sounding very lovely with my T1 second gen. The RTs give a nice sparkle up top but may be a bit sibilant with poorer recorded tracks


----------



## wwmhf

Your impression and mine suggest me to avoid those 6ZH1P-EVs with notches on theirs glass tubes.


----------



## frogmeat69

My MkIII was purchased on Massdrop, came with power tubes with markings that show a pentagon symbol, with 6H6N under that, and 1082 under that, nothing else on tube.  Are these Russian? I thought the stock tubes were of Chinese origin.
 I was looking at the matched pair of Novosibirsk 6H6P-I Power Tubes from Yen Audio, but being a tube noob, would I benefit from these over the tubes that came with it, especially at the cost?
 Any good suggestions on better tubes, and where to get them?
 I have purchased a few driver tubes and have been enjoying the whole rolling adventure so far, and really enjoy the 6ZH1P-EVs I received with the notches and little rocket symbol, sorry you guys above don't like them.
 Thanks in advance!!


----------



## wwmhf

frogmeat69 said:


> My MkIII was purchased on Massdrop, came with power tubes with markings that show a pentagon symbol, with 6H6N under that, and 1082 under that, nothing else on tube.  Are these Russian? I thought the stock tubes were of Chinese origin.
> I was looking at the matched pair of Novosibirsk 6H6P-I Power Tubes from Yen Audio, but being a tube noob, would I benefit from these over the tubes that came with it, especially at the cost?
> Any good suggestions on better tubes, and where to get them?
> I have purchased a few driver tubes and have been enjoying the whole rolling adventure so far, and really enjoy the 6ZH1P-EVs I received with the notches and little rocket symbol, sorry you guys above don't like them.
> Thanks in advance!!


 
  
 According to what I read from here, "matched" or not does not matter much. I bought a few 6H6P from ebay for my LD MKIV SE, so far, I have no complain yet.


----------



## d4rkch1ld

frogmeat69 said:


> My MkIII was purchased on Massdrop, came with power tubes with markings that show a pentagon symbol, with 6H6N under that, and 1082 under that, nothing else on tube.  Are these Russian? I thought the stock tubes were of Chinese origin.
> I was looking at the matched pair of Novosibirsk 6H6P-I Power Tubes from Yen Audio, but being a tube noob, would I benefit from these over the tubes that came with it, especially at the cost?
> Any good suggestions on better tubes, and where to get them?
> I have purchased a few driver tubes and have been enjoying the whole rolling adventure so far, and really enjoy the 6ZH1P-EVs I received with the notches and little rocket symbol, sorry you guys above don't like them.
> Thanks in advance!!


 
 Pentagon is symbol of novosibirsk factory so yeah they are soviet.


----------



## frogmeat69

wwmhf said:


> According to what I read from here, "matched" or not does not matter much. I bought a few 6H6P from ebay for my LD MKIV SE, so far, I have no complain yet.


 
  
 Thanks for the info!


d4rkch1ld said:


> Pentagon is symbol of novosibirsk factory so yeah they are soviet.


 
 Cool, thanks. I have seen other tubes with that symbol on them, and usually were Soviet tubes, but wanted to be sure. So these are considered decent tubes? They have no problems with my Beyer or AKG cans, power to spare. And with the 6ZH1P-EVs it sounds really good, great bass, sweet vocals and awesome sound stage, just wondering if it can get better with more rolling the 6H6n's?


----------



## MIKELAP

frogmeat69 said:


> wwmhf said:
> 
> 
> > According to what I read from here, "matched" or not does not matter much. I bought a few 6H6P from ebay for my LD MKIV SE, so far, I have no complain yet.
> ...


 
 At Yen Audio tubes are overpriced if you want russian tubes you could look here   http://tubes-store.com/index.php


----------



## WilliamLeonhart

frogmeat69 said:


> My MkIII was purchased on Massdrop, came with power tubes with markings that show a pentagon symbol, with 6H6N under that, and 1082 under that, nothing else on tube.  Are these Russian? I thought the stock tubes were of Chinese origin.
> I was looking at the matched pair of Novosibirsk 6H6P-I Power Tubes from Yen Audio, but being a tube noob, would I benefit from these over the tubes that came with it, especially at the cost?
> Any good suggestions on better tubes, and where to get them?
> I have purchased a few driver tubes and have been enjoying the whole rolling adventure so far, and really enjoy the 6ZH1P-EVs I received with the notches and little rocket symbol, sorry you guys above don't like them.
> Thanks in advance!!


 
 Can you spot some number on them, like mine has "81-04", which I suppose means it was produced in April 1981.


----------



## frogmeat69

williamleonhart said:


> Can you spot some number on them, like mine has "81-04", which I suppose means it was produced in April 1981.


 
 Yeah, mine has the numbers 1082.


----------



## lglions

d4rkch1ld said:


> Pentagon is symbol of novosibirsk factory so yeah they are soviet.


 
 To be absolutely correct - pentagon symbol is a symbol that's been used in soviet union to mark items that went through special quality control. Sometimes you can see characters "OTK" inside which stands for Quality Control Department.


----------



## WilliamLeonhart

frogmeat69 said:


> Yeah, mine has the numbers 1082.


 
 That's quite close to mine. But mine don't have the rocket logos on the box


----------



## d4rkch1ld

lglions said:


> To be absolutely correct - pentagon symbol is a symbol that's been used in soviet union to mark items that went through special quality control. Sometimes you can see characters "OTK" inside which stands for Quality Control Department.


 

 I passed information i found here.
 http://www.ominous-valve.com/russtube.html


----------



## wwmhf

lglions said:


> To be absolutely correct - pentagon symbol is a symbol that's been used in soviet union to mark items that went through special quality control. Sometimes you can see characters "OTK" inside which stands for Quality Control Department.


 
  
 Depending on what kind of pentagon symbol. Yours is quality control, but many tubes made by Novosibirsk has a smaller pentagon logo.


----------



## bharat2580

TIME FOR SOME PICTURES


----------



## WilliamLeonhart

Wow. Really impressive.


----------



## Kenjiwing

mikelap said:


> 6HM5 ARE DRIVERS (FRONT) 6N6P-IR are power tubes (back). By the way there's no stupid question i asked the same one when i started


 
 Mike,
  
 I just got these and hooked them up today. Should I change any settings on my actually little dot mk3? Ive heard there is a dip switch or something to change based on your tubes.


----------



## MIKELAP

kenjiwing said:


> mikelap said:
> 
> 
> > 6HM5 ARE DRIVERS (FRONT) 6N6P-IR are power tubes (back). By the way there's no stupid question i asked the same one when i started
> ...


 
 The 6HM5 tubes are EF95 types check under your amp to see if jumpers left and right channel are on EF95 setting  theres 3 pins jumper should be on second and third pin from the left   . If EF92 type tube jumper should be on second and third pin from right  .Also i would recommend getting long jumpers way easier to remove than  the stock ones  it can be a pita  if they fall in the amp


----------



## Wreckgar7

Hi guys, im Kinda new to tube rolling, and i just placed an order of brimar 6ak6 thinking they were 6ak5, do the 6ak6 work with my LD mk IV se?


----------



## MIKELAP

wreckgar7 said:


> Hi guys, im Kinda new to tube rolling, and i just placed an order of brimar 6ak6 thinking they were 6ak5, do the 6ak6 work with my LD mk IV se?


 
 Never heard of those here return them if you can if you want to try tubes theres quite a few on page 77 of this thread one of the favorites here being the 6HM5 YUGO Tall bottle


----------



## TrollDragon

wreckgar7 said:


> Hi guys, im Kinda new to tube rolling, and i just placed an order of brimar 6ak6 thinking they were 6ak5, do the 6ak6 work with my LD mk IV se?


 

 You would have to strap pin 2 to pin 7 like the 6AU6 to use those.


----------



## Wreckgar7

trolldragon said:


> You would have to strap pin 2 to pin 7 like the 6AU6 to use those.




Alright, thanks alot  Have anyone tried the 6ak6? Impressions?


----------



## WilliamLeonhart

Looking at the specs I don't think they're compatible, the amperage is different. But I don't know for sure.
  
 http://www.radiomuseum.org/tubes/tube_6ak5.html
 http://www.radiomuseum.org/tubes/tube_6ak6.html


----------



## TrollDragon

williamleonhart said:


> Looking at the specs I don't think they're compatible, the amperage is different. But I don't know for sure.
> 
> http://www.radiomuseum.org/tubes/tube_6ak5.html
> http://www.radiomuseum.org/tubes/tube_6ak6.html


 

 Are you talking about heater current? As long as it is below the 400mA threshold we chose as a safety point for the transformer, I don't see a problem.
  
 The 6AK6 has tranconductance of 2300 where the 6AK5 is 5000, so it might be a little low in amplification.
 http://www.nj7p.org/Tubes/PDFs/Frank/127/6AK6.pdf
 http://www.nj7p.org/Tubes/PDFs/Frank/127/6AK5.pdf


----------



## Wreckgar7

Alright, well i already bought them so maby ill try em out later  another question about the c3g siemens, i think i can get a pair really cheap, but theyre not a so called "matched pair" how important is that with the C3gs?


----------



## gibosi

wreckgar7 said:


> Alright, well i already bought them so maby ill try em out later
> 
> 
> 
> ...


 
  
 The LD does not require matched pairs for drivers. That said, it is best if both tubes were manufactured by the same company at around the same time. And further, if one is brand new and the other is on its last legs, that would not be very good... 
  
 On the other hand, the C3g is a 10,000 hour tube, so even if they are used, they may still have lots of life left in them.


----------



## Wreckgar7

Hi guys, i just want to make sure i got this right, to use the c3g all i need is this adapter?
  
 http://www.ebay.com/itm/2piece-Gold-plated-C3G-TO-6AK5-tube-converter-adapter-/191424601510?hash=item2c91cb9da6:g:aY4AAOSwMmBVtGEM
  
 And if i decide to go into the 6sn7 game, which adapter(s) do i need?


----------



## gibosi

wreckgar7 said:


> Hi guys, i just want to make sure i got this right, to use the c3g all i need is this adapter?
> 
> http://www.ebay.com/itm/2piece-Gold-plated-C3G-TO-6AK5-tube-converter-adapter-/191424601510?hash=item2c91cb9da6:g:aY4AAOSwMmBVtGEM
> 
> And if i decide to go into the 6sn7 game, which adapter(s) do i need?


 
  
 Yes, that C3g to 6AK5 adapter should be fine.
  
 With respect to the 6SN7, I assume you are thinking of using a pair as power tubes? If so just search eBay for "6CG7 6SN7" and you will see a number of adapters. You want the 8-pin octal on top and 9-pin miniature on the bottom. The gold-plated metal-wrapped ones are more expensive and likely better quality, but the plastic ones should also work fine.


----------



## Wreckgar7

gibosi said:


> Yes, that C3g to 6AK5 adapter should be fine.
> 
> With respect to the 6SN7, I assume you are thinking of using a pair as power tubes? If so just search eBay for "6CG7 6SN7" and you will see a number of adapters. You want the 8-pin octal on top and 9-pin miniature on the bottom. The gold-plated metal-wrapped ones are more expensive and likely better quality, but the plastic ones should also work fine.


 

 Yeah exactly. Thanks a million man, im reading through the threads but there are quite a few pages and alot to take in


----------



## AzraelDarkangel

wreckgar7 said:


> Hi guys, i just want to make sure i got this right, to use the c3g all i need is this adapter?
> 
> http://www.ebay.com/itm/2piece-Gold-plated-C3G-TO-6AK5-tube-converter-adapter-/191424601510?hash=item2c91cb9da6:g:aY4AAOSwMmBVtGEM
> 
> And if i decide to go into the 6sn7 game, which adapter(s) do i need?


 

 I wonder if this will work with the Little Dot 1+? I assume it will if there is enough room for the adapters. What about the metal collar around the socket? It looks like it might be in the way of the adapter?


----------



## AzraelDarkangel

I answered my own question about the socket:
http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/6000#post_10512665


----------



## lglions

wreckgar7 said:


> Hi guys, i just want to make sure i got this right, to use the c3g all i need is this adapter?
> 
> http://www.ebay.com/itm/2piece-Gold-plated-C3G-TO-6AK5-tube-converter-adapter-/191424601510?hash=item2c91cb9da6:g:aY4AAOSwMmBVtGEM
> 
> And if i decide to go into the 6sn7 game, which adapter(s) do i need?


 
  
 You need 6SN7 to 6CG7 adapter. I found 6SN7 no good for low impedance cans.
  
 Please note - both adapters from the vendor you mentioned above will require socket extenders or you will need to remove rings on MK3.


----------



## gulakpi

While the 6SN7 sounds good and cool, it has serious distortion when used with low-Z cans!  Use it only with high-Z cans!


----------



## superdux

you might need socket savers as extenders for your adapters.


----------



## Wreckgar7

Since the c3g has 8 pins and no larger space between any of them, does it matter what pin goes in where?


----------



## MIKELAP

wreckgar7 said:


> Since the c3g has 8 pins and no larger space between any of them, does it matter what pin goes in where?


 

 There is a guide pin in center of tube and a slot to receive the tube guide pin in the socket ,did you by any chance remove outer shell ? if you did you have to put guide pin assembly in the same place as before .


----------



## Wreckgar7

mikelap said:


> There is a guide pin in center of tube and a slot to receive the tube guide pin in the socket ,did you by any chance remove outer shell ? if you did you have to put guide pin assembly in the same place as before .



No i didnt remove it, still waiting for The adapter. Ok let me see If i got this right, (at work so cant check) Theres a pin guide on the outer shell and also on the adapter? So i just need to compare and plug 1 to 1 and so on?


----------



## MIKELAP

wreckgar7 said:


> mikelap said:
> 
> 
> > There is a guide pin in center of tube and a slot to receive the tube guide pin in the socket ,did you by any chance remove outer shell ? if you did you have to put guide pin assembly in the same place as before .
> ...


 

 Yes ,check where male key is on tube and insert in female slot on socket


----------



## Wreckgar7

mikelap said:


> Yes ,check where male key is on tube and insert in female slot on socket



Aah okay, thanks alot! Cant wait to try em out


----------



## MIKELAP

One important thing DO NOT WIGGLE TUBE WHEN INSERTING OR REMOVING FROM  SOCKET i had one break they are very fragile


----------



## Wreckgar7

mikelap said:


> One important thing DO NOT WIGGLE TUBE WHEN INSERTING OR REMOVING FROM  SOCKET i had one break they are very fragile



Yeah that sounds familliar, ill do my best not to


----------



## MIKELAP

Last thing if you have a hard time inserting tube in socket , it might be the tab in the socket hole thats pushed out  to much towards  the center of socket .With a small screwdriver just push  tab back


----------



## Wreckgar7

mikelap said:


> Last thing if you have a hard time inserting tube in socket , it might be the tab in the socket hole thats pushed out  to much towards  the center of socket .With a small screwdriver just push  tab back



Ah Great tips man  this all got me wondering again, as said before i Will check for The male key to female socket, but if thats all I have to do, what Was all that about the pin manual on the shell and adapter? Sorry for being so amateurish about this :/


----------



## MIKELAP

wreckgar7 said:


> mikelap said:
> 
> 
> > Last thing if you have a hard time inserting tube in socket , it might be the tab in the socket hole thats pushed out  to much towards  the center of socket .With a small screwdriver just push  tab back
> ...


 

 If you mean the tab , maybe its best to cross that bridge when you get there, maybe it will be ok just be advised in case tube is hard to insert


----------



## Wreckgar7

mikelap said:


> There is a guide pin in center of tube and a slot to receive the tube guide pin in the socket ,did you by any chance remove outer shell ? if you did you have to put guide pin assembly in the same place as before .



No this that i quoted you on. I mean if all I need to connect the male key to female socket when i connect tube to adapter. What Was this all about then?


----------



## MIKELAP

Heres a shot of the underside of socket ,the tab im talking about is where the arrow is pointing it sticks out from under the socket .Sometimes its pushed in toward center of hole which makes it hard to insert tube, like i said just push it back out  a bit


----------



## Wreckgar7

mikelap said:


> Heres a shot of the underside of socket ,the tab im talking about is where the arrow is pointing it sticks out from under the socket .Sometimes its pushed in toward center of hole which makes it hard to insert tube, like i said just push it back out  a bit


 
 ah okay i get it now, it was probably a mix between being a noob at this, english being second language and working the graveyard shift right now, i misunderstood. But i get it now, thank you for your kindness and patience  much love


----------



## TrollDragon

I'd just cut the tab off...


----------



## Gezzaman

I modded the LDIII with an external heater for using 6SN7 as power tubes ... but i accidently bought 6AS7 tubes...
 when I plug the 6AS7 tubes into the 6SN7 to 6CG7 adapters , the light on the buck converter turns off... , when I take the tubes out leaving the adapters on the LD, the light turns back on.. so the tubes is cutting off the power supply somehow.
  
 I thought i modded the 9 pin socket saver wrong so I tried putting my normal power tubes into the modded 9 pin socket saver and it powers normally ( so I didn't wired them wrong)


 whatt is happening D:

 PS: followed this guide, I sniped off the 4 + 5 legs on both socket savers and attached the wires onto the legs for the external power supply


----------



## bharat2580

wouldn't you want a linear supply ? why not use the inbuilt transformer and use something like a passive divider or a zener maybe.


----------



## gibosi

gezzaman said:


> I modded the LDIII with an external heater for using 6SN7 as power tubes ... but i accidently bought 6AS7 tubes...
> when I plug the 6AS7 tubes into the 6SN7 to 6CG7 adapters , the light on the buck converter turns off... , when I take the tubes out leaving the adapters on the LD, the light turns back on.. so the tubes is cutting off the power supply somehow.
> 
> I thought i modded the 9 pin socket saver wrong so I tried putting my normal power tubes into the modded 9 pin socket saver and it powers normally ( so I didn't wired them wrong)
> ...


 
  
 What is the amperage rating of your external power supply? It should be at least 7.5 amps. And similarly, what is the maximum amperage of your buck converter? Otherwise, I have no idea what is happening....
  


bharat2580 said:


> wouldn't you want a linear supply ? why not use the inbuilt transformer and use something like a passive divider or a zener maybe.


 
  
 The inbuilt transformer is rated for about 2.5 amps, I believe. Thus the need for an external power supply able to provide 5 + amps for two 6AS7s. We generally recommend at least a 7.5 amp power supply to handle any power-on surges.


----------



## Gezzaman

i bought a 12V 8A external power supply and the buck convert supports up to 8A


----------



## gibosi

It seems that you bought the correct parts, so it must be something else..... Double check all your connections and when you get a pair of 6SN7, see if the same thing happens. And good luck!


----------



## Gezzaman

I just ordered some 6SN7, hope they work...
  
 just FYI the 6AS7 tubes i bought were these
  
 http://www.ebay.com/itm/111600090554?_trksid=p2060353.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT
  
 these SHOULD of worked on the modded LD3 ye?


----------



## gibosi

Yes, the Russian Svetlana 6N13S are plug-in replacements for the 6AS7G. So it shouldn't make any difference if you use these or a pair of RCA 6AS7G.


----------



## WilliamLeonhart

Ordered a pair of un-notched Voshs and RTC 5654 yesterday. This will be the first time I've got new tubes since the 6hm5 of a year ago. Can't say how excited I am.


----------



## ls2gto

Just ordered the mullard ef92 m8161's. What's the typical burn in for these, and tips with how long to leave the little dot on at a time while burning them in? Also thanks to everyone in this thread for all of the info! Looking forward to tube rolling.


----------



## MIKELAP

ls2gto said:


> Just ordered the mullard ef92 m8161's. What's the typical burn in for these, and tips with how long to leave the little dot on at a time while burning them in? Also thanks to everyone in this thread for all of the info! Looking forward to tube rolling.


 
 If i remember correctly 50 hours should be enough .And manufacturer says not to leave amp on more than 8 hours .Personnally i never leave my tube amps on when im not there .better safe than sorry .


----------



## gulakpi

I do not leave my Mk4 on when not in use.  Mike is right!  Better safe than sorry!
 However, I once or twice forgot to switch it off and left it on for 24 hrs.  No harm done and the LD is barely warm!  
 The LD's are ruggedly built and I knew someone who left it on for over a week for "better sound".  I cannot hear a significant difference in SQ once the amp is on for more than 30 minutes. YMMV!


----------



## WilliamLeonhart

I forgot and left my I+ on for about 15 hours (including the time I spent on listening during the evening). Thankfully it survived but I'm never careless like that again

The tubes benefit from burn-in but I don't believe the samething happens to the amp itself.


----------



## Wreckgar7

Can i use the 6SL7 in the 6SN7 adapter without any external power source? If so, is the SL better then the SN?
 And how about the ECC32?
  
 Which 6sn7 tubes are recommended?
 Btw, im planning on using these as powertubed


----------



## Gezzaman

gibosi said:


> It seems that you bought the correct parts, so it must be something else..... Double check all your connections and when you get a pair of 6SN7, see if the same thing happens. And good luck!


 
  
 The *6N8S *i bought just arrived, The rig fully works now! finally, been waiting so long for audio bliss
  
Still confused as to why the *6N13S *didnt work...


----------



## Gezzaman

wreckgar7 said:


> Can i use the 6SL7 in the 6SN7 adapter without any external power source? If so, is the SL better then the SN?
> And how about the ECC32?
> 
> Which 6sn7 tubes are recommended?
> Btw, im planning on using these as powertubed


 
  
 If you are planning on using 6SN7 as powertubes then yes you need an external heater.


----------



## MIKELAP

gezzaman said:


> wreckgar7 said:
> 
> 
> > Can i use the 6SL7 in the 6SN7 adapter without any external power source? If so, is the SL better then the SN?
> ...


 
 Only need 6CG7 TO 6SN7adapter to use 6SN7 as power tubes                       http://www.ebay.com/itm/221065459067?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT


----------



## gibosi

gezzaman said:


> The *6N8S *i bought just arrived, The rig fully works now! finally, been waiting so long for audio bliss
> 
> Still confused as to why the *6N13S *didnt work...


 
  
 The fact that the 6N8S work seems to indicate that you did everything right. As to why the 6N13S didn't work, we simply don't have enough data. If you stumble across a pair of inexpensive RCA 6AS7, I would encourage you to give them a try to see what happens.
  
 Cheers


----------



## i luvmusic 2

I have no clue why this  MK III makes my Kenwood KM-992 humming.Any suggestions from folks using their LD amps as a PRE-AMP?


----------



## Gezzaman

gibosi said:


> The fact that the 6N8S work seems to indicate that you did everything right. As to why the 6N13S didn't work, we simply don't have enough data. If you stumble across a pair of inexpensive RCA 6AS7, I would encourage you to give them a try to see what happens.
> 
> Cheers


 
  
 When i try plug the 6N13S tubes in, the LED light on my transformer and the buck converter nearly turns off (like power is being drawn heaps) and emitts a very high pitched sound.

 When i plug the 6SN7 in the same adapters, the LED lights just dim a little and slowly goes back to full brightness and no high pitch sound.


----------



## TrollDragon

gezzaman said:


> When i try plug the 6N13S tubes in, the LED light on my transformer and the buck converter nearly turns off (like power is being drawn heaps) and emitts a very high pitched sound.
> 
> When i plug the 6SN7 in the same adapters, the LED lights just dim a little and slowly goes back to full brightness and no high pitch sound.


 

 Without the LD turned on.
 Take a single 6N13S tube and test it on each side to see if it dims your external power supply.
 Repeat the test with each tube.
  
 If each tube glows one at a time on either side your tubes and connections should be okay. If you put both tubes in and the external power supply dims and emits a sound, your source adapter does not have enough voltage/current (have you measured it) or the buck converter is possibly defective. Does it have any adjustments other than output voltage?


----------



## WilliamLeonhart

Has anyone here tried the Little Bear P5 amp? I'm looking for a cheap preamp for my speaker system that can re-use my collections of EF95 tubes and only found these Little Bears so far.


----------



## hypnos1

williamleonhart said:


> Has anyone here tried the Little Bear P5 amp? I'm looking for a cheap preamp for my speaker system that can re-use my collections of EF95 tubes and only found these Little Bears so far.


 
  
 Hi there. Just had a look at my old stomping ground before I defected  to the Feliks-Audio Elise, and noticed your post lol.
  
 Just for fun I was tempted to give the cheap LB a try, and was very surprised by the sound quality for its price...HOWEVER...the old adage "you get what you pay for" seemed to apply here alas. First, I was rather dismayed by how hot the case got, and after very little use I gave it  to my brother who some weeks later said the pre-amp out packed up! Of course any amp can have problems, but in my bones I wasn't at all surprised...just my own (and my brother's!) experience...others may have found differently. I personally would advise spending more on a better quality unit...GOOD LUCK!!...


----------



## jamesbdh

I apologize if there is a post in here that i missed but all the rolls i saw were for the 650's.   
  
 I just bought the little dot mk3 and have an HD600. what are the recommended tubes now?  I have seen this pair recommended a lot and was going to pull the trigger but then information overload.  I am not looking to mod the amp at this point just swap the tubes.
  
 http://www.ebay.com/itm/2x-Voshkod-6ZH1P-EV-Matched-Pair-Little-Dot-Amp-III-IV-/291043635707
 http://www.ebay.com/itm/2x-Russian-6H6P-I-Power-Tubes-Little-Dot-Amp-Mk-II-6N6-/290582767617


----------



## WilliamLeonhart

jamesbdh said:


> I apologize if there is a post in here that i missed but all the rolls i saw were for the 650's.
> 
> I just bought the little dot mk3 and have an HD600. what are the recommended tubes now?  I have seen this pair recommended a lot and was going to pull the trigger but then information overload.  I am not looking to mod the amp at this point just swap the tubes.
> 
> ...


 
 I don't know about the power tubes but the Voskhods you posted are not only overpriced but also not the rocket logo version.
 As many others have said, there are at least 2 versions of the Voskhods 6zh1p, one of which have notches and one of which don't. I have both and much much prefer the later - it's a whole new level of clarity and soundstage, all the while retaining the distinct "tube sound".
 Anyway here's what mine look like:
 http://www.ebay.com/itm/6ZH1P-EV-6J1P-EV-EF95-5AK5-Matched-pair-Mil-Tubes-TOP-/131776334100?hash=item1eae7b4914:g:dvcAAOxyfpJSUZPV
  
 I think you will also like these
 http://www.ebay.com/itm/6HM5-EC900-EI-Yugoslavia-NOS-matched-pair-Little-Dot-Amp-/251765500700?hash=item3a9e64ab1c:g:dRUAAOxyeZNTQ491
  
 The Voskhods and the EI Yugos are perhaps the 2 most often-recommended tubes in the Little Dot threads, so I think it's best you start with these 2 first.


----------



## WilliamLeonhart

hypnos1 said:


> Hi there. Just had a look at my old stomping ground before I defected  to the Feliks-Audio Elise, and noticed your post lol.
> 
> Just for fun I was tempted to give the cheap LB a try, and was very surprised by the sound quality for its price...HOWEVER...the old adage "you get what you pay for" seemed to apply here alas. First, I was rather dismayed by how hot the case got, and after very little use I gave it  to my brother who some weeks later said the pre-amp out packed up! Of course any amp can have problems, but in my bones I wasn't at all surprised...just my own (and my brother's!) experience...others may have found differently. I personally would advise spending more on a better quality unit...GOOD LUCK!!...


 
 I guess that's not surprising as well. Thanks for saving me a few bucks  Cheers


----------



## jamesbdh

6hm5 as the


williamleonhart said:


> I don't know about the power tubes but the Voskhods you posted are not only overpriced but also not the rocket logo version.
> As many others have said, there are at least 2 versions of the Voskhods 6zh1p, one of which have notches and one of which don't. I have both and much much prefer the later - it's a whole new level of clarity and soundstage, all the while retaining the distinct "tube sound".
> Anyway here's what mine look like:
> http://www.ebay.com/itm/6ZH1P-EV-6J1P-EV-EF95-5AK5-Matched-pair-Mil-Tubes-TOP-/131776334100?hash=item1eae7b4914:g:dvcAAOxyfpJSUZPV
> ...


 
 So the 6HM5 are the power and 6zH1p as the drivers?


----------



## wwmhf

jamesbdh said:


> 6hm5 as the
> So the 6HM5 are the power and 6zH1p as the drivers?


 
  
 Both 6hM5 and 6ZH1P are drivers.


----------



## jamesbdh

wwmhf said:


> Both 6hM5 and 6ZH1P are drivers.



The 6hm5 looked too big for the drivers. Sorry. Are there recommended power tubes for those or in general?


----------



## MIKELAP

jamesbdh said:


> wwmhf said:
> 
> 
> > Both 6hM5 and 6ZH1P are drivers.
> ...


 
 Power tube reviews PAGE 201 POST# 3007 i also use 6SN7 tubes as power tubes but you will need adapters


----------



## jamesbdh

mikelap said:


> Power tube reviews PAGE 201 POST# 3007 i also use 6SN7 tubes as power tubes but you will need adapters



I saw those and seemed like 6N6P-ir were the ones I would be looking for but was not sure if someone had found something better since that post was a bit older. Also having a hard time finding them for sale through the recommended websites at the beginning post.


----------



## MIKELAP

jamesbdh said:


> mikelap said:
> 
> 
> > Power tube reviews PAGE 201 POST# 3007 i also use 6SN7 tubes as power tubes but you will need adapters
> ...


 
 Depending on sound signature you want 6SN7 are  warmer sounding it all depends what you like but the 6N6P-IR for the price is very good here's a link                       http://www.ebay.com/itm/171310973012?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT


----------



## WilliamLeonhart

Has anyone here got the mk3 with RTC tubes? I ordered a pair and the box says March 80, are the ones with the Mk3 the same?


----------



## bharat2580

Just got the 6HM5 today , hae rolled a few E95 and E92 before preferred the Voskhod and mullards, 
  
 something strange happened, the left tubes bottom elements glowed (heated up) from the top of the first plate to the bottom of the tube like a pulse.
  then stopped, sounds good, dint do it when i started it again ...
  
  
 any idea, what why.


----------



## wwmhf

bharat2580 said:


> Just got the 6HM5 today , hae rolled a few E95 and E92 before preferred the Voskhod and mullards,
> 
> something strange happened, the left tubes bottom elements glowed (heated up) from the top of the first plate to the bottom of the tube like a pulse.
> then stopped, sounds good, dint do it when i started it again ...
> ...


 
  
 Both 6HM5 do this on my little dot iv se, and I think this is a known bonus of using 6HM5 in addition to its good sound ....


----------



## WilliamLeonhart

Mine light up like that too. Every time.


----------



## bharat2580

wwmhf said:


> Both 6HM5 do this on my little dot iv se, and I think is a known bonus of using 6HM5 in addition to its good sound ....


 

 some kind of self heating ? they sound good for a new tube with no burn in.


----------



## bharat2580

burn in time for these ?


----------



## XSAMURAI

i'm looking for the best tube set for MK II , any suggestion ?


----------



## HungryPanda

xsamurai said:


> i'm looking for the best tube set for MK II , any suggestion ?


 
 I use russian 6N6P military stamped OTK power tubes and Golden Voskhod 6J1P-EV95 (for a bright sound) or Mullard M8100 for a warm lush sound


----------



## HungryPanda

I also like the Tung-Sol JTL 6AK5's. I'm using those at the moment with my HD650's and Beyer T1.2's


----------



## bharat2580

The 6hm5 are perfect, the speed the bass the extention perfect mids and perfect highs. Controlled and subtle. 

Love these way above the rest


----------



## Nin9

Hi guys, I have a mk2 circuit 3.0 revision. I know the 6N6P-I is supported as a power tube, is the 6N6P-IR also supported? Thanks.


----------



## HungryPanda

I'm pretty sure it is


----------



## leobigfield

Hi guys! Has anyone here listened the Little Bear P2-1 tube hybrid amp and can compare it to the Little Dot I+? I was looking for the Little dot when i stumbled across a Little Bear auction on E-bay so i got them for $26 and for compliment/upgrade i ordered a matched pair of Voshkod for $20 and rolled some LM4562NA and for $50 total package i pretty much never had my D2000 sound this good! The tubes really gave a very good signature to the amp and the LM4562 make everything soo cristal clear that really make the tubes shine!!
  
 I've always been a budget guy so my previous DAC/AMP was a fiio E10, then i got a Q1 that sounded really bad with my D2000 and now i'm with an SMSL M3 connected to the Little Bear and pretty much debating if i should jump to the little dot since this combination sounds soo damn good... What do you think guys?
  
 Also, has anyone some pairing experience with the Denon D2000? Any good pairing indication? The Voshkod are really good but would love to listen to a slightly thicker midrange while maintaining everything else from the Voshkod.
  
 Thanks!


----------



## WilliamLeonhart

leobigfield said:


> Hi guys! Has anyone here listened the Little Bear P2-1 tube hybrid amp and can compare it to the Little Dot I+? I was looking for the Little dot when i stumbled across a Little Bear auction on E-bay so i got them for $26 and for compliment/upgrade i ordered a matched pair of Voshkod for $20 and rolled some LM4562NA and for $50 total package i pretty much never had my D2000 sound this good! The tubes really gave a very good signature to the amp and the LM4562 make everything soo cristal clear that really make the tubes shine!!
> 
> I've always been a budget guy so my previous DAC/AMP was a fiio E10, then i got a Q1 that sounded really bad with my D2000 and now i'm with an SMSL M3 connected to the Little Bear and pretty much debating if i should jump to the little dot since this combination sounds soo damn good... What do you think guys?
> 
> ...


 
 I don't have the P2-1, but I also looked into their preamp and in the end decided against it, as I have found somewhere that Little Bear has build problems. But you seems to be enjoying the Little Bear tremendously without any hassle, so I guess all is fine.
 Anyway, the case for the LD is that it also improved greatly with good tubes and opamp, and for sure they sound better than the Vali 2 and the Aune T1 (which is a bit incorrect as the T1 has tube buffer for its DAC; I use my LD with ODAC). The LD I+ is aimed for low-imp cans, so depending on your headphones it may even be better than the mk2 or mk3. 
 So all in all I can say that the LD I+ is a great amp, but to get straight to the point I don't know how it fares in comparison with the Little Bear. But considering that I didn't like the LD I+ too much at first (the stock tubes and stock opamp were lousy), perhaps you should stick with the Bear.


----------



## leobigfield

williamleonhart said:


> I don't have the P2-1, but I also looked into their preamp and in the end decided against it, as I have found somewhere that Little Bear has build problems. But you seems to be enjoying the Little Bear tremendously without any hassle, so I guess all is fine.
> Anyway, the case for the LD is that it also improved greatly with good tubes and opamp, and for sure they sound better than the Vali 2 and the Aune T1 (which is a bit incorrect as the T1 has tube buffer for its DAC; I use my LD with ODAC). The LD I+ is aimed for low-imp cans, so depending on your headphones it may even be better than the mk2 or mk3.
> So all in all I can say that the LD I+ is a great amp, but to get straight to the point I don't know how it fares in comparison with the Little Bear. But considering that I didn't like the LD I+ too much at first (the stock tubes and stock opamp were lousy), perhaps you should stick with the Bear.


 
 Thanks for your thoughts!
  
 Any recommendation for a good complement for my Voshkod tubes? While they sound great with my D2000 they don't sound that great with my other gear.


----------



## WilliamLeonhart

For my LD buying new tubes is much more efficient than buying new opamps, if a change in sound is what you're after. Can't guarantee if you'll like these, but if the Voskhods don't match well with your other cans then perhaps the GE JAN 5654 will do, as they're much faster and put more emphasis in mids. Also, do try the EI Yugoslavia 6hm5


----------



## gulakpi

williamleonhart said:


> For my LD buying new tubes is much more efficient than buying new opamps, if a change in sound is what you're after. Can't guarantee if you'll like these, but if the Voskhods don't match well with your other cans then perhaps the GE JAN 5654 will do, as they're much faster and put more emphasis in mids. Also, do try the EI Yugoslavia 6hm5


 
  
 The 6HM5 can directly replace the EF95 stock tubes without jumper changes.  It is inexpensive and is highly recommended. Give it a try!


----------



## WilliamLeonhart

Received my burson v5 at the start of the week and still haven't got the chance to try it yet. I'm genuinely excited but also can't stand the wait. Gosh I hate the wait


----------



## drofeel71

williamleonhart said:


> Received my burson v5 at the start of the week and still haven't got the chance to try it yet. I'm genuinely excited but also can't stand the wait. Gosh I hate the wait



Do it! You won't regret it


----------



## GodsInHisHeaven

I have 3 Burson V5 in my Asus STX 2. Those were a huge upgrade in sound quality. I haven't heard 700€+ tube amps though.


----------



## ChrisP3

I'm thinking of selling my LD MK3 with 6N6P-IR power tubes and 6HM5 drivers to build a bottlehead crack. Anyone heard these two?


----------



## gulakpi

chrisp3 said:


> I'm thinking of selling my LD MK3 with 6N6P-IR power tubes and 6HM5 drivers to build a bottlehead crack. Anyone heard these two?


 
 Why not build the Crack before selling the LD?  Then you can have fun to compare and keep the one you like!


----------



## WilliamLeonhart

godsinhisheaven said:


> I have 3 Burson V5 in my Asus STX 2. Those were a huge upgrade in sound quality. I haven't heard 700€+ tube amps though.





drofeel71 said:


> Do it! You won't regret it


 only 5 days more till I go home


----------



## WilliamLeonhart

Can anyone help me identify these RCA tubes? Should they be worth $10 a pair?


----------



## GodsInHisHeaven

Is the little dot mk 3 with some Mullard M8100 / CV4010 powerful enough for the HD 800?


----------



## MIKELAP

godsinhisheaven said:


> Is the little dot mk 3 with some Mullard M8100 / CV4010 powerful enough for the HD 800?


 
 That's the HP i use with MK3


----------



## i luvmusic 2

chrisp3 said:


> I'm thinking of selling my LD MK3 with 6N6P-IR power tubes and 6HM5 drivers to build a bottlehead crack. Anyone heard these two?


 
 Sell the MK III don't build the CRACK get a vintage receiver and make a speaker tap for your Headphones.


----------



## WilliamLeonhart

williamleonhart said:


> Can anyone help me identify these RCA tubes? Should they be worth $10 a pair?


 
 Hullo


----------



## gibosi

williamleonhart said:


> Can anyone help me identify these RCA tubes? Should they be worth $10 a pair?


 
  
 I don't really understand what you are asking...
  
 To my eyes, there is no mystery here: 1960's vintage RCA 5654. Whether they are worth $10/pair is a question only you can answer. After all, everyone has different ears and different gear. That said, $10 seems pretty cheap to me....


----------



## WilliamLeonhart

Thanks for the reply. Actually before asking I did google "RCA 5654" but not much showed up and I can't imagine what their sound would be like, what year should be best, mil-spec or not etc. Too bad I can't audition them because I'm shipping from another country.


----------



## IvoTaze

Hi Guys 
  
 I am new to this forum, to Little Dot Amps and to tube rolling... well, to be honest, I know nothing at all about tubes 
  
 I have been reading thou, but I am still centuries behind you guys.  Yet, thanks to this forum, thread and specially to all of you, I have decided to buy my first tube headphone amp! And today I got confirmation my new Little Dot MK IV SE is on its way!
  
 So I've been trying to read trough this thread, but it's huuuuge, and it ends up being a little bit confusing because many of you have moded your amps, and it looks like there were different versions of LD amps with different compatibilities.
  
 So I have some questions for you, I hope you don't hate me for re-asking a lot of stuff, but I want to start my tube rolling adventures and I want to be sure of what I am doind before:
  
 1) Can I use E88CC and/or 7N7 as power tubes on my LD MK IV SE without any modding or external PSU? I understand 7N7 requires adapting, not so sure about E88CC...??
  
 1.1) So I understand there are switches for driver tube compatibility, but what about rolling these power tubes? I read somewhere that 6922/ECC88 are not directly compatible with 6H30... can someone help me understand why? I mean, pinouts match, right? and also heater voltage, and amperage is lower on ECC88 than on 6H30...
  
 2) Can I use C3g as driver tubes without any modding or external PSU? Only with adapters?
  
 2.1) I have ordered a few C3g removed from military equipment, so they may be damaged. How can I test them? Is it safe to plug them into my new LD? I think I can test for shorts, but not sure about testing anything else...
  
 2.2) How do I need to set the Amp switches to use C3gs?
  
 4) Can someone point me on the right direction on how to make adapters for all of these tubes?
  
 4.1) Using 7N7 as power tube = loctal to LD's 9-pin mini?
 4.2) Using E88CC as power tubes = same pin out? No adapter needed?
 4.3) Using C3g as drivers = loctal to LD's 7-pin?
  
 Sorry for the many many questions. I managed to put together a lot of info, but I am not sure if I got everything right, and being a noob, even while I have pinouts and specs for all of these tubes, I don't know how to read them properly and how they work together... I mean, it's a lot to digest, and I am not sure how they may affect my new LD's circuitery.
  
 Thanks! and many thanks again


----------



## gibosi

ivotaze said:


> So I have some questions for you, I hope you don't hate me for re-asking a lot of stuff, but I want to start my tube rolling adventures and I want to be sure of what I am doind before:
> 
> 1) Can I use E88CC and/or 7N7 as power tubes on my LD MK IV SE without any modding or external PSU? I understand 7N7 requires adapting, not so sure about E88CC...??
> 
> ...


----------



## IvoTaze

Ups, I got my message posted by mistake (CTRL+ENTER seems to submit the form)
  
 Anyway, Thank you for taking the time to answer all these questions for me Gibosi  !!!
  
 Quote:


gibosi said:


> For me, it is easier to purchase ready-made adapters. That said, I suggest that you consult the data sheets for these tubes in order to make a diagram showing how to reroute the pins corresponding to the heaters, cathodes, grids and anodes, from one tube to the other. But of course, actually building these adapters is another matter.


 
  
 I was going to buy adapters but when I was buying my C3Gs, as the price was good but I wasn't sure about the condition, I decided to buy 4 instead, and they come with 4 Loctal socket.
  
 So at least to start, maybe using the socket could be a good way to learn and also speed up things, cause I am in Argentina and it takes a while to get stuff shipped here.
  
 Anway, I will post all my diagrams here before attempting anything, but I'll also search through the thread before. I am almost sure I saw some rerouting tables for C3Gs already.
  


gibosi said:


> (...) However, I have rolled hundreds and hundreds of tubes through my LD without any damage to the amp. Either the tubes worked or they didn't.


 
  
 Hundreds, wow, like a said... I am centuries behind, but can I use your experience to get some recommendations? 'cause I would also like to buy some cheaper plug and play tubes to compare, and to get some different yet nice-sounding options...
  
 Viskhods for example were given some room at the beginning of this thread... are they worth? tung-sol?
  
 What would you recommend me on the cheap and also on the not so cheap? I don't want to go over the hundreds, and at least to start, maybe testing more will be more entertaining 
  
 And finally, do you have experience with PVSANE? Are the Marking II really worth the price? I love the look of those tubes...
  
 My new HD-800-S are also on the way, they are actually the reason behind my decision to get an amp. So my whole experience with this amp is going to be performed with them. But I also own HD-598 and HD-555).
  
 Is burning in tubes and headphones together a good idea?
  
 Thank you once more


----------



## gibosi

ivotaze said:


> Hundreds, wow, like a said... I am centuries behind, but can I use your experience to get some recommendations? 'cause I would also like to buy some cheaper plug and play tubes to compare, and to get some different yet nice-sounding options...
> 
> Viskhods for example were given some room at the beginning of this thread... are they worth? tung-sol?
> 
> ...


 
  
 I should say that I haven't listened to my LD in over a year now, so I am going by memory...
  
 As I recall, my favorite driver tubes were the C3g, the tall 6HM5 and 1950's 6AV6. As I have an LD1+, I rolled op amps rather than power tubes. However, I added an external 9-pin socket and heater supply, so I often rolled 6SN7, E88CC, and so forth, as drivers....
  
 And as I think on this a bit more, I would suggest that you use 6SN7 rather than the 7N7 for power tubes. The 7N7 was manufactured by only two companies, Sylvania and National Union, regardless of the labeled brand. Further, over 90% are Sylvania and less than 10% are National Union. So not much of a selection. On the other hand, there are hundreds of different 6SN7 to choose from, including the current production PSVANE and Shuguang. Speaking of which, I have no experience with current production Chinese and Russian tubes. First, they are more expensive than many, if not most of the old vintage tubes. And second, according to the ears of several people I respect, they are not good enough to justify their price. That said, if I could get some for cheap, I would definitely like to try....
  
 But of course, we all have different ears and different gear, so what I like the best and what you like the best could very well be different... and even very different... lol


----------



## IvoTaze

gibosi said:


> As I recall, my favorite driver tubes were the C3g, the tall 6HM5 and 1950's 6AV6. As I have an LD1+, I rolled op amps rather than power tubes. However, I added an external 9-pin socket and heater supply, so I often rolled 6SN7, E88CC, and so forth, as drivers....
> 
> And as I think on this a bit more, I would suggest that you use 6SN7 rather than the 7N7 for power tubes. The 7N7 was manufactured by only two companies, Sylvania and National Union, regardless of the labeled brand. Further, over 90% are Sylvania and less than 10% are National Union. So not much of a selection. On the other hand, there are hundreds of different 6SN7 to choose from, including the current production PSVANE and Shuguang. Speaking of which, I have no experience with current production Chinese and Russian tubes. First, they are more expensive than many, if not most of the old vintage tubes. And second, according to the ears of several people I respect, they are not good enough to justify their price. That said, if I could get some for cheap, I would definitely like to try....
> 
> But of course, we all have different ears and different gear, so what I like the best and what you like the best could very well be different... and even very different... lol


 
  
 Awesome! I'll look into those driver options right now! I only went ahead and looked for power tubes because I heard the C3Gs play nicely with 6SN7s.
  
 [edited]
  
 Sorry, forgot to add:
  
 Any particular brand or version of the 6HM5? Cause I just ran a quick search on eBay and there are several, and what about 6AV6?
  
 [/edited]
  
 As for the 7N7s I got the recommendation from Jac van de Walle (from "Jacmusic" in Germany), so I bought some Sylvania. Not only because they were 1/5th if not 1/10th of the price, but also because I am going to get 4 Loctal sockets with my C3Gs, and 7N7 use loctal too, so it was almost the perfect deal to start 
  
 As for the taste, I couldn't agree more... I'll share my experiences once I get my hands on everything I've ordered. As of now... all I have is waiting time and your great help  'cause EVERYTHING else is either flying or with a friend of mine in Germany... he's coming back to Argentina next Wednesday and bringing my cans and some of the tubes with him, but no Amp yet


----------



## gibosi

I should also point out that in order to use the 6AV6, it is necessary to cut off pins 5 and 6. And then, change the switches in your LD to use EF91/92 tubes.
  
 There is a chart somewhere in this long thread detailing most, if not all, of the tubes we tried and how to use them. However, I can't remember the page number... Perhaps someone else can help here?


----------



## IvoTaze

Well, now that you mention it.... I ran into that table (it's on the first pages) and also into the instructions to cut off pins for some tubes. It's just that the table didn't have the C3Gs so I assumed it was sort of outdated, but maybe it was limited to the plug and play or no socket adapter options?
  
 By the way, was there an specific year or brand for the ones you recommended? I mean, for 6AV6 its the 50s not sure about the brand, and what about the 6HM5s?
  
 I promise you this is the last one... for now  lol. Thanks gibosi


----------



## gibosi

ivotaze said:


> Well, now that you mention it.... I ran into that table (it's on the first pages) and also into the instructions to cut off pins for some tubes. It's just that the table didn't have the C3Gs so I assumed it was sort of outdated, but maybe it was limited to the plug and play or no socket adapter options?
> 
> By the way, was there an specific year or brand for the ones you recommended? I mean, for 6AV6 its the 50s not sure about the brand, and what about the 6HM5s?
> 
> I promise you this is the last one... for now  lol. Thanks gibosi


 
  
 The table at the beginning of this thread lists the standard EF95, EF92 and EF91 tubes suggested by the manufacturer. But a good bit later, a number of us began to roll through a bunch of tubes that were not on the "recommended" list, including the 6AV6. 
  
 Acapella11 compiled a chart... Oh, I found it! Page 77: Table of Compatible Tubes
  
 http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/1140#post_9392055
  
 Lots of good information there....
  
 As for the 6HM5, there are two versions, short bottle and tall bottle. To my ears, the short bottle versions are not good. However, all the tall-bottle versions are quite good. As I recall, some were manufactured by Mullard, some by Sylvania and some from an unknown manufacturer, but usually labeled GE. So if you are going to try them, go for any of the tall bottles. In fact, they are all cheap, so try all of them.


----------



## IvoTaze

Well, it looks like my Amp finally made it to Argentina! It still needs to go through customs, but I guess I'll have it sooner than expected 
 And my friend arrives this Wednesday from Germany, bringing my new HD-800-S with him! This is me 
	

	
	
		
		

		
			





 happy!
  
 So I am already thinking on my next steps, and I thought I can also use your help here:
  
 Considering the C3Gs I've bought have scratches all over their metal casings, which of the following would you do?
  
 a) Leave them just like they are, scratched. Not my preferred option.
  
 b) Removing the metal casings as explained before on this thread. Does this affect the life span?
  
 c) Re-Painting the casing. Do I need special paint? Can this affect the tube somehow? Interference for example?
  
 Thanks for all your great help!


----------



## bharat2580

i am not sure the little dot is the best match for the hd800s, i would go for the send hdvd600 or a nice warm SS amp to be honest. LD is good for the lower 600,650


----------



## IvoTaze

bharat2580 said:


> i am not sure the little dot is the best match for the hd800s, i would go for the send hdvd600 or a nice warm SS amp to be honest. LD is good for the lower 600,650


 
  
 Damn, it's too late! But don't worry, based on all the things I've been reading here, I may get a pair of 650 later. And when budget allows, then maybe the hdvd... when and if it allows! 
  
 Any recommendations on what to do with my C3Gs?


----------



## gibosi

a) Leave them just like they are, scratched.


----------



## IvoTaze

gibosi said:


> a) Leave them just like they are, scratched.


 
  
 I guess I will have to do that then... at least for now 
  
 As for removing two C3Gs from the loktal sockets they come with. Any recommendations? (I've heard their pins are very fragile)
  
 I bought 4 but I only need 2 on those sokets,because I would like to use the other 2 sockets for the 7N7, to build the adapters


----------



## gibosi

In my experience, this depends on the quality of the socket. The loctal socket in the adapters I used with my LD were not very good, and when removing tubes from these adapters, I felt it necessary to use a small screwdriver as a wedge. In the end, I decided to simply leave the C3gs plugged into the adapters permanently.
  
 However, my current amp has two loctal sockets and can run C3g natively. These installed loctal sockets are of much better quality, and inserting and removing C3g from these sockets is easy and there is no risk of damaging the tubes.


----------



## IvoTaze

I believe the ones I have bought together with the C3G are NOS Amphenol, just like these ones:

http://m.ebay.com/itm/5-Zoccoli-Amphenol-per-C3G-/281989307801

They were mentioned before in the thread as a decent alternative, somebody knows if they are good?


----------



## WilliamLeonhart

So does the HD800S pair well with the LD you have (as it mk2)? 


ivotaze said:


> Damn, it's too late! But don't worry, based on all the things I've been reading here, I may get a pair of 650 later. And when budget allows, then maybe the hdvd... when and if it allows!
> 
> Any recommendations on what to do with my C3Gs?


----------



## IvoTaze

To soon to know, my new HD-800S will be here this Wednesday, and my amp is still going through customs and it usually takes days until they categorize and release shipments here in Argentina.

Once I get my hands on them, I will still need to burn them both in. But don't worry, I am sure there are some great experienced fellows here that can help you with your question...

For example, Bharat2580 just told me a few posts ago he believes they are way better matched with hdvd600, and he's not the only one, I have been reading for a while about this and there are lots of posts recommending the same config.

I've only decided to go with LD because I really want to try tubes and I love the whole tube rolling idea, so LD was a great (yet not very expensive) alternative to get started  and I have also found a nice amount of posts with good experiences pairing HD-800 (not the S) to LD's.


----------



## Arcee

ivotaze said:


> To soon to know, my new HD-800S will be here this Wednesday, and my amp is still going through customs and it usually takes days until they categorize and release shipments here in Argentina.
> 
> Once I get my hands on them, I will still need to burn them both in. But don't worry, I am sure there are some great experienced fellows here that can help you with your question...
> 
> ...




I'm sure you will enjoy them! The LDMKIII is great with the HD800's but you need to experience with the tubes. I've got Yugoslavia 6HM5 drivers now, which makes the HD800's really shine. Also power tubes make a difference, I've now got 6N6P-I's which are a bargain on tubes-store.com just a few dollars, and which have a slower response which makes the otherwise somewhat clinical HD800's nice and round with fuller bass.


Sent from my iPad using Tapatalk


----------



## eschell27

Any suggestions for mk iv se tubes that will help tame the highs and bring out the mids of beyer dt990 600ohm while still pairing well with hd650?


----------



## bharat2580

eschell27 said:


> Any suggestions for mk iv se tubes that will help tame the highs and bring out the mids of beyer dt990 600ohm while still pairing well with hd650?


 

 the mallards should do the trick the EF95 and the 92 , the tung sol is ok too and so is the hm5 but its for me really very well extended, depends on what you want, the ef92 and 95 mallards is the best bet


----------



## bharat2580

ivotaze said:


> To soon to know, my new HD-800S will be here this Wednesday, and my amp is still going through customs and it usually takes days until they categorize and release shipments here in Argentina.
> 
> Once I get my hands on them, I will still need to burn them both in. But don't worry, I am sure there are some great experienced fellows here that can help you with your question...
> 
> ...


 

 for tubes; 
  
 get the mullards EF95,EF92 and the voskhod EF95, the 6HM5 thats all you need along with the 6n6p30 the gold pin power tube. investing more is not really worth it, better get a high end SS which would suit your 800
  
 also i am not sure why the hdvd800,600 is not so famous thats the best amp i ever heard, i heard it with the 650 and the 800, and could compare it to my ld mk 4 and other amps , and i was blown away, it was just perfect i can't want more from an amp. i can't afford it but if you can get it, take my word for it.


----------



## WilliamLeonhart

bharat2580 said:


> the mallards should do the trick the EF95 and the 92 , the tung sol is ok too and so is the hm5 but its for me really very well extended, depends on what you want, the ef92 and 95 mallards is the best bet


 
  


eschell27 said:


> Any suggestions for mk iv se tubes that will help tame the highs and bring out the mids of beyer dt990 600ohm while still pairing well with hd650?


 
 All the tubes Bharat listed will pair really nice with the DT990 but I do think some of them might be too much for the hd650. The DT990 is quite v-shaped and energetic IME while the HD650 is smooth and laid-back. Anyway some tubes are very cheap (6hm5, ge jan 5654w) so why don't you experiment instead?


----------



## IvoTaze

bharat2580 said:


> for tubes;
> 
> get the mullards EF95,EF92 and the voskhod EF95, the 6HM5 thats all you need along with the 6n6p30 the gold pin power tube. investing more is not really worth it, better get a high end SS which would suit your 800


 
  
 Will definitely do... Thanks for the recommendations 
  
 BTW, just received my Senns, it's a pitty I can only use them with my FiiO E17 for now... well, probably for a while, because I need to put a lot of paperwork in to get my LD out of customs!
  
 Apparently we are now enforcing "electric safety" meassures here in Argentina and I cannot get my amp out without homologation! arrgggg
  
 Anyway, together with my cans I also received the following:
  
*4 x C3G (+ 1 extra)... *used and removed from military equipment.
  
 Any ideas on how can I check them while I wait for my Amp? Some even have bumps on the metal covers... :S
  

  

  

  
*5 x Sylvania 7N7*... these are NOS and apparently they are in perfect shape.
  
 Regarding the 7N7... I was speaking with a technician here and he's telling me that 6SN7 (or in this case 7N7) cannot be used instead of the 6H30Pi because they output less milliamps per triode (20 mA max compared to 50 mA) and the also have very different internal resistances. I am really out of my area of expertise here, so I have no idea... 
  
 Can someone help me with the technical explaination on why they can be used? And what are the risks if any? (This is for an LD MK IV SE).
  
 Thanks!


----------



## Rattle

I am new to LDMKIII and HD600, been listening to with stock tubes for a few days now, I already want to tube roll ! Should I let this new setup burn in more ? How much more will it change?
  
 I was looking at getting these, thoughts ?
  
 http://www.ebay.com/itm/142019136831?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT
  
 http://www.ebay.com/itm/171310973012?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT
  
 I just gathered I'd like these just from reading this thread.


----------



## gibosi

ivotaze said:


> Anyway, together with my cans I also received the following:
> 
> *4 x C3G (+ 1 extra)... *used and removed from military equipment.
> 
> ...


 
  
 C3g: Unless you have access to an amp or a tube tester, I do not know of any way to check them. But apparently, you will have your amp soon, so I suggest you clean the pins and put them aside until your amp arrives.
  
 7N7: There is no risk. It is perfectly safe to use 7N7/6SN7 as power tubes. However, as the technician pointed out, they can't provide as much current as the 6H30P. They are not as powerful. And therefore, the 7N7/6SN7 do not drive low-Z cans nearly as well. That said, with high-Z cans, many prefer the 7N7/6SN7.
  
 The 5687 is closer to the 6H30P in terms of power, but the pin-out is different, and that means another, different adapter is necessary....


----------



## sallqvist

I have about 10 pairs of E180F 6688 tubes/valves that my late grandfather use to own. Is there any way these will work in a little bot amp? Do i need to buy some kind of adaptor or shall i buy another amp? if so which adaptor will work soldiring d.i.y is out of the question atleast for me. 6.3v 0,3a


----------



## gibosi

sallqvist said:


> I have about 10 pairs of E180F 6688 tubes/valves that my late grandfather use to own. Is there any way these will work in a little bot amp? Do i need to buy some kind of adaptor or shall i buy another amp? if so which adaptor will work soldiring d.i.y is out of the question atleast for me. 6.3v 0,3a


 
  
 These look to be nice tubes. However, the E180F is a 9-pin pentode, whereas, the LD is designed to use 7-pin pentodes. With 6.3V / 0.3A heaters, the E180F does not require an external heater power supply, but still, a simple pin-adapter would be necessary.
  
 Unfortunately, I don't see any adapters on eBay, but if you really want to use these tubes, you might want to contact one of the Chinese adapter vendors on eBay and request that they build you a pair of adapters, E180F on top and 6AK5 on the bottom. In the past, I have had good luck getting custom-made adapters from *xulingmrs*
  
 http://www.ebay.com/usr/xulingmrs?_trksid=p2047675.l2559
  
 A very quick search on Google did not turn up any commercially available amps using the E180F, so getting some custom-made adapters for use in the LD might be your best alternative.
  
 Good luck!


----------



## gulakpi

This amp seems to use teh E180F natively.
 Just for your reference!
 http://www.ebay.com.hk/itm/Nobsound-6J9-Vacuum-Tube-Integrated-Amplifier-Mini-Audio-HiFi-Stereo-Headphone-/121963064292?hash=item1c6590abe4:g:LGIAAOSwkEVXF-f3


----------



## gibosi

Good work! I thought that there had to be an amp that used these, but I spent only a few minutes searching Google and didn't see it. And as cheap as this little amp is, I think it would be better than trying to make them work in an LD.


----------



## frogmeat69

Just received in the mail today four 6DT6A tubes, got them for $8 shipped, 2 Sylvania with yellow paint, 1 with reddish paint, and 1 marked Raytheon. I read they can be used in the 1+ and MK III, but I'm not sure which jumper settings. I thought I read they can run in both EF95 and EF91/92 settings, is this correct?


----------



## MIKELAP

frogmeat69 said:


> Just received in the mail today four 6DT6A tubes, got them for $8 shipped, 2 Sylvania with yellow paint, 1 with reddish paint, and 1 marked Raytheon. I read they can be used in the 1+ and MK III, but I'm not sure which jumper settings. I thought I read they can run in both EF95 and EF91/92 settings, is this correct?


 
 page 77 post #1154 this page is your friend and this tube uses the EF95 setting  or if you use the wire mod in EF91/92


----------



## XSAMURAI

do i need change jumper for installing GE JAN 5654W on LD MK II ?


----------



## gibosi

xsamurai said:


> do i need change jumper for installing GE JAN 5654W on LD MK II ?


 
  
 It depends....  What tubes are you using now? If you are using 6J1 / 6AK5 / EF95, then no, it is not necessary to change the jumpers. If you are using EF91 / EF92, then yes, it is necessary to change the jumpers.


----------



## XSAMURAI

gibosi said:


> It depends....  What tubes are you using now? If you are using 6J1 / 6AK5 / EF95, then no, it is not necessary to change the jumpers. If you are using EF91 / EF92, then yes, it is necessary to change the jumpers.


 
  
 thanks for reply , now listening to 5654w and sound much more better than the stock tube , but i think need little bit time to burn in


----------



## Montres0r

Hello all, 
  
 I've recently purchased the LDMKiii from eBay and am interested in achieving the best sound stage for fps gaming.  The source is my Xonar STX and my HP are the DT990 600ohm.  I've been going through this thread trying to determine what the best tubes (and power tubes) would be and it's a big overwhelming.  Also, I'm not crazy about the idea of opening the thing and getting out the soldering iron / doing any sort of heavy modification.  
  
 Any help would be greatly appreciated,
  
 Thank you in advance.


----------



## WilliamLeonhart

For driver tube with big soundstage at cheap price go for the EI Yugoslavia 6hm5. For power tubes I can't tell as I use the LD I+


----------



## Montres0r

williamleonhart said:


> For driver tube with big soundstage at cheap price go for the EI Yugoslavia 6hm5. For power tubes I can't tell as I use the LD I+




Thanks for the recommendation. Price isn't really an issue (within reason), though. It came with a pair of (2x 6z1p (6Ж1П)) tubes, not sure if those are the same as the ones listed on the OP's review. Are the 6hm5s better than those?

Thanks.


----------



## WilliamLeonhart

Do those tubes come in boxes that have rocket logos? Do they have notches on their bodies?


----------



## MIKELAP

montres0r said:


> Hello all,
> 
> I've recently purchased the LDMKiii from eBay and am interested in achieving the best sound stage for fps gaming.  The source is my Xonar STX and my HP are the DT990 600ohm.  I've been going through this thread trying to determine what the best tubes (and power tubes) would be and it's a big overwhelming.  Also, I'm not crazy about the idea of opening the thing and getting out the soldering iron / doing any sort of heavy modification.
> 
> ...


 
 A good plug & play power tube is the Russian 6N6P-ir tube usually around  $25.00 to $30.00 a pair on Ebay


----------



## Montres0r

williamleonhart said:


> Do those tubes come in boxes that have rocket logos? Do they have notches on their bodies?


 

 No rocket logos.  I've seen those ones on the eBay during my research.  Here is what I was sent:
  
http://imgur.com/a/MBDO7


----------



## IvoTaze

Hey Guys! How have you been?!
  
 I have finally received my MK IV SE and HD-800-S!   
  
 So far I am amazed with both of them, but as soon as I started to listen through the HD-800-S I noticed my entire music collection needed a severe upgrade, so I've been downloading a lot of new stuff, or better put: I've been re-downloading a lot of new and old stuff... at way better quality 
  
 These cans hate some stuff, low-res, flat rock, poor recordings (or maybe it's better to say poorly mastered, cliped, compressed, etc.?), they are assassins!!! or just too damn good and accurate to allow me to enjoy those pieces, lol.
  
 I have already experienced this when jumping from HD-4XX to HD-5XX, but the change was massive this time... now I can understand why a lot of people keep their old beloved cans. Sometimes you want to enjoy listening to some of the crappy stuff too! 
  
 But have to admit, I love the way live recordings sound, jazz is simply amazing, electronic too, vocals are mind blowing, specificaly female signers... and the depth and spaciality... wow... I am blown away. I have been staying up late for the last entire week... I just can't stop listening them!
  
 Still haven't been able to make the adapters to try my new tubes, but I have my sister in germany and I want to see if I can send her a few extra tubes to roll 
  
 I am going to put together a few options here, and dedicate some time on eBay, but I would appreciate your help to find good deals or at least to validate the ones I may find, because I am just too new to this and I don't want to buy fake or simply pay in excess.
  
 I am considering buying a pair of Voskhod's 6N23P, I have found multiple listings, but I don't know their dates. Any seller to recommend?
  
 I'll also try to get the ones you recommended before some posts ago, but I need to leave now, so I'll be back and put together a list tonight 
  
 Thank you all for your great advice!


----------



## gibosi

ivotaze said:


> I have finally received my MK IV SE and HD-800-S!
> 
> [snip]
> 
> I am considering buying a pair of Voskhod's 6N23P, I have found multiple listings, but I don't know their dates. Any seller to recommend?


 
  
 I hope you are aware of the fact that the 6N23P is a double triode, usually considered as equivalent to the E88CC/6922. And as such it will not work in your LD without an external 9-pin socket and a pair of 7-pin test socket savers, or something similar.
  
 The dating system on these tubes uses Roman numerals for the month followed by two regular numbers for the year. For example, X11-75 (Dec, 1975) or VIII-78 (Aug, 1978).  The folks in the Lyr forums consider production from the mid to late 1970's to be the best, roughly 1974 through 1980.
  
 I can personally vouch for Head-Fi user rb2013 as a very safe and fair vendor. He tests every tube he sells, whereas most of the Russian and Ukrainian vendors do not. That said, as these central Asian vendors often sell them cheap, I bought bunches of them from several different vendors and most of them were fine.


----------



## IvoTaze

gibosi said:


> I hope you are aware of the fact that the 6N23P is a double triode, usually considered as equivalent to the E88CC/6922. And as such it will not work in your LD without an external 9-pin socket and a pair of 7-pin test socket savers, or something similar.
> 
> The dating system on these tubes uses Roman numerals for the month followed by two regular numbers for the year. For example, X11-75 (Dec, 1975) or VIII-78 (Aug, 1978).  The folks in the Lyr forums consider production from the mid to late 1970's to be the best, roughly 1974 through 1980.
> 
> I can personally vouch for Head-Fi user rb2013 as a very safe and fair vendor. He tests every tube he sells, whereas most of the Russian and Ukrainian vendors do not. That said, as these central Asian vendors often sell them cheap, I bought bunches of them from several different vendors and most of them were fine.




Oh man, sorry: I meant to say Voshkod 6ZH1P-EV. For some reason I had the 23 in my mind, probably because it was mentioned on a newer post.

Have you tried both? Are the 6N23P worth the effort of putting together such an adapter?

Sorry for the confusion! And thanks for replying so fast gibosi


----------



## MIKELAP

ivotaze said:


> gibosi said:
> 
> 
> > I hope you are aware of the fact that the 6N23P is a double triode, usually considered as equivalent to the E88CC/6922. And as such it will not work in your LD without an external 9-pin socket and a pair of 7-pin test socket savers, or something similar.
> ...


 
   actually they are called Voskhods  .


----------



## gibosi

ivotaze said:


> Oh man, sorry: I meant to say Voshkod 6ZH1P-EV. For some reason I had the 23 in my mind, probably because it was mentioned on a newer post.
> 
> Have you tried both? Are the 6N23P worth the effort of putting together such an adapter?
> Sorry for the confusion! And thanks for replying so fast gibosi


 
  
 Strictly in terms of sonics, if you have a pair of C3g, then in my opinion, the time and money spent putting together an adapter to allow the use of double triodes probably is not worth it. These double triodes are not better than a pair of C3g, they are just somewhat different. However, as we all have different ears and gear, you might very well prefer one over the other. A slightly different shade of your favorite color so to speak.
  
 In practice, the cost of putting such an adapter together is almost trivial compared to the cost of the tubes. Once you have such an adapter, you may well want to try every kind of double triode ever made and soon you could find yourself sliding down the slippery slope to vacuum tube addiction! lol. So again, chasing after these very subtle differences might not be worth the extra time and money.
  
 That said, I am more of a tube roller and collector than I am an audiophile, and being able to try new and different tubes is great fun and very rewarding. So for me, it was definitely worth it...
  
 But yes indeed, I am in fact a tube addict! I have well over 1000 tubes and counting... One came in the mail today, I have another on the way from Europe, and I am bidding on yet another...  lol


----------



## IvoTaze

Absolutely! And somehow I feel I will end up sharing the same cult... I haven't tried my C3G yet and I am already looking forward to my next tubes. Anxious perhaps? Maybe, but I feel I am going to enjoy the different colors, that's why I want at least 2-3 options to play with, to compare, etc.
  
 As for the adapters, I will probably wait until I have successfully built the ones for my C3G, before engaging on other projects 
  
 So what say you? Is this 6ZH1P-EV matched pair decently priced? (they are from from 77, but probably expensive for what I had in mind)
  
 http://www.ebay.com/itm/2x-Matched-Voskhod-Gold-pins-Gold-grid-6ZH1P-EV-6AK5-EF95-403B-5654-6J1-1977-NIB-/131446387039?hash=item1e9ad0b15f:g:K-AAAOSwBLlU3aaG
  
 I am also considering buying these 6HM5 from the 80s:
  
 http://www.ebay.com/itm/6HM5-EC900-EI-Yugoslavia-NOS-matched-pair-Little-Dot-Amp-/251765500700?hash=item3a9e64ab1c:g:dRUAAOxyeZNTQ491
  
 But I am going to PM rb2013 before buying anything... I guess he is in the states? Not sure if it makes much sense to ship to Germany, lol
  
 Thanks


----------



## gibosi

ivotaze said:


> Absolutely! And somehow I feel I will end up sharing the same cult... I haven't tried my C3G yet and I am already looking forward to my next tubes. Anxious perhaps? Maybe, but I feel I am going to enjoy the different colors, that's why I want at least 2-3 options to play with, to compare, etc.
> 
> As for the adapters, I will probably wait until I have successfully built the ones for my C3G, before engaging on other projects
> 
> ...


 
  
 I'm not sure the gold pin version of the 6ZH1P is worth the extra money. In fact, I wonder if they are the real deal. It is my impression that premium Russian tubes used rhodium pins, not gold. But I freely admit that I do not know for sure....
  
 The 6HM5 vendor is the same one that most of us have purchased from.
  
 And I should say that to my knowledge, the only tube rb2013 sells is the 6N23P.
  
 Have fun!


----------



## Rattle

rattle said:


> I am new to LDMKIII and HD600, been listening to with stock tubes for a few days now, I already want to tube roll ! Should I let this new setup burn in more ? How much more will it change?
> 
> I was looking at getting these, thoughts ?
> 
> ...


 
  
  
 I ordered the driver tubes listed here, going to order the power tubes eventually. Do I have to change any jumpers or need any adapter for the power tubes?


----------



## frogmeat69

rattle said:


> I ordered the driver tubes listed here, going to order the power tubes eventually. Do I have to change any jumpers or need any adapter for the power tubes?


 

 No changes needed, and those are nice power tubes, it's what I'm running with some Mullards for the drivers.


----------



## Rattle

frogmeat69 said:


> No changes needed, and those are nice power tubes, it's what I'm running with some Mullards for the drivers.




Sweet thanks for the info. My LDMKIII is probably 50 hours in usage wise. By the time I get the drivers I should be ready to swap and the LD will be burned in. Then I'll order those power tubes.


----------



## HungryPanda

Those are the very tubes I have in my Little Dot right now


----------



## Kenjiwing

See below.


----------



## MIKELAP

kenjiwing said:


> Guys.. need help with my little dot mk 3 it looks like it has stopped working all together.
> 
> It powers on and passes traffic but does nothing to the signal.
> 
> ...


 
 Have you checked your tubes


----------



## gulakpi

kenjiwing said:


> It powers on and passes traffic but does nothing to the signal.
> 
> If I turn the amp off it passes audio.. if I turn it on it passes audio but does not change the signal at all. The volume knob does nothing.


 
  
 Good chance is: you've connected your input cables to the Output jacks of your Little Dot!


----------



## WilliamLeonhart

kenjiwing said:


> Guys.. need help with my little dot mk 3 it looks like it has stopped working all together.
> 
> It powers on and passes traffic but does nothing to the signal.
> 
> ...


what?


----------



## Kenjiwing

.


----------



## Kenjiwing

Update on this.. im now plugged into the input with my RCA cables and I am getting audio out of the left can. The right can has no audio on it at all... any ideas?
  
 All I hear is static or a low hum in the right ear. 
  
 Also I know this is somehow related to the amp and not wiring bc as soon as I swap out my friends little dot 1+ in the exact same wiring everything works great..


----------



## superdux

swap the tubes, see if channel silence follows!


----------



## WilliamLeonhart

kenjiwing said:


> Update on this.. im now plugged into the input with my RCA cables and I am getting audio out of the left can. The right can has no audio on it at all... any ideas?
> 
> All I hear is static or a low hum in the right ear.
> 
> Also I know this is somehow related to the amp and not wiring bc as soon as I swap out my friends little dot 1+ in the exact same wiring everything works great..


 
 It's the amp then. I had the same problem with my first I+


----------



## IvoTaze

Hey Guys,

What do you think about these voskhods?

http://www.ebay.com/itm/291814506767?ssPageName=STRK:MESELX:IT&_trksid=p3984.m1558.l2649

They are from 1981, and have OTK 9, ruggedized, military.

I am about to order a few, but wanted to get your feedback before 

Thanks!!


----------



## HungryPanda

Those look just like the ones I have


----------



## HungryPanda

mine have OTK1 stamped on them though


----------



## IvoTaze

And how do yours sound? Did you have any chance to compare with other years? Thanks HungryPanda!


----------



## HungryPanda

They sound terrific, prefer them to the mullards and tung-sols


----------



## WilliamLeonhart

These have notches. Had ones similar but didn't like them too much. Sold them to another guy who has the mk3 and he likes it much better than his Siemens (which I think is among the smoothest tubes on the market...). Then I bought another pair of Voskhods, which has the rocket logo and don't have notches. It's one of my most favourite tubes. The sound sig is quite different from the old ones.


----------



## IvoTaze

williamleonhart said:


> These have notches. Had ones similar but didn't like them too much. Sold them to another guy who has the mk3 and he likes it much better than his Siemens (which I think is among the smoothest tubes on the market...). Then I bought another pair of Voskhods, which has the rocket logo and don't have notches. It's one of my most favourite tubes. The sound sig is quite different from the old ones.




So you didn't like these? Or maybe they needed some more time to break. 

So what say you? Avoid the ones with notches? I had some from the '75 in sight but they ran out of 

Where did you buy yours? I am being picky because I only have a limited amount of shipments allowed per year to Argentina, and I would like to use them wisely 

So any help will be highly appreciated!


----------



## droido256

Question, how long do tubes last? Are there any current producers of 6n6/6h6 power tubes, and the compatible driver tubes? Just kinda thinking down the road here, if 80's and older tube supplies dry up.


----------



## WilliamLeonhart

ivotaze said:


> So you didn't like these? Or maybe they needed some more time to break.
> 
> So what say you? Avoid the ones with notches? I had some from the '75 in sight but they ran out of
> 
> ...


 
 Got mine from a seller in Singapore. The notched Voskhods of mine were made in 1981 if my memory serves. They didn't have the rocket logo on the boxxes. You may like those, but in my experiences the one without notches are best. If you an't find them on ebay, go for the ones that at least have the rocket logo. 
  
 Oh and there are some gold pins that sell for crazy money on ebay too. Unfortunately I have no experiences with those, but nothing with gold pins should be wrong lol


----------



## gibosi

williamleonhart said:


> Got mine from a seller in Singapore. The notched Voskhods of mine were made in 1981 if my memory serves. They didn't have the rocket logo on the boxxes. You may like those, but in my experiences the one without notches are best. If you an't find them on ebay, go for the ones that at least have the rocket logo.
> 
> Oh and there are some gold pins that sell for crazy money on ebay too. Unfortunately I have no experiences with those, but nothing with gold pins should be wrong lol


 
  
 I am quite sure that when these were manufactured they had rhodium pins. And it is important to remember that the plating on the pins, whether gold or rhodium, has absolutely no affect on the sound. These platings were applied because they are resistant to corrosion, and never having to clean pins is a very good thing.
  
 However, there is something about gold pins that causes people to go a little crazy... lol. And while I have no proof, I believe that when you see Voskhods with gold pins, that plating was not done at the factory. Likely, it was done sometime after production, perhaps many years after, And very likely it was done in order to justify a higher selling price to audiophiles, such as those in this forum. lol.
  
 Regardless, Voskhod 6ZH1P with gold pins are not worth the extra cost. I consider them to be a novelty and a collectors item. If you are simply looking for a pair of Voskhods for your amp go for the inexpensive ones with rhodium pins.


----------



## droido256

Well after ordering a lot of 10 Russian power tubes, and 10 Russian driver tubes......, and researching a lot tubes last longer than i figured lol I.... I think im set for a few years


----------



## HungryPanda

droido256 said:


> Well after ordering a lot of 10 Russian power tubes, and 10 Russian driver tubes......, and researching a lot tubes last longer than i figured lol I.... I think im set for a few years


 
 I got mine in a lot of eight so I'm set too


----------



## droido256

hungrypanda said:


> I got mine in a lot of eight so I'm set too




Also discovered i had ebay bucks, so also snagged a pair of Raytheon CK5654. More or less because its well Raytheon hahahaha


----------



## HungryPanda

I have not gotten a hold of any Raytheon tubes yet


----------



## droido256

dxanex said:


> I have the Voshkods and I don't care for them on my HD650's, and with my K550's forget it. Painful highs to my ears. People say that they settle down after a hundred hours or so, but I'm not going to spend that much time on something like that if I'm not a fan out the gate. That's just me. First impressions are everything.
> 
> I have some Tung-Sols coming in the mail now, which are said to be a slightly less warm version of the Mullard 8100. I haven't tried the Mullards yet, but that all depends on how the Tung-Sols sound to me. I'll let you know my impressions when I get them.
> 
> If you want to try the Voshkods PM me. I have some I'll let go for a good price if you live in the USA.



Glad to hear actually about the sharper highs on the Voshies. I have a few vintage headphones, esp a k-160 i think will benefit. Which is primarily why i bought the MK-2, for my vintages.


----------



## droido256

hungrypanda said:


> I have not gotten a hold of any Raytheon tubes yet



Im going to run the stock tubes till they end first, and then try the Raytheons. Should be interesting lol. Just waiting to get the amp.


----------



## HungryPanda

Tung-Sols are very good


----------



## HungryPanda

Soon as I changed the stock power tubes for the Russian one my Little dot came to life with much more power


----------



## droido256

I wonder how long in actuality a set of tubes (2xpower, 2xdrive) last? Seems like a average of 5k hours.


----------



## gulakpi

I have not heard of too many cases that you can run a tube till it "ends"!
 Yes!  Tubes have a life span, but it does not usually mean they will stop working.  They just deteriorate in sound quality (become less dynamic compared to a healthy tube!) very gradually.
 Most of us have at least a few sets of tubes to roll, and from my (limited) experience with my audiophile friends, this never happens!
 We will find a new favorite set before the tubes get to much used.


----------



## droido256

Ah, i was thinking lol theyll just stop working. The only interaction i had with tubes was as a kid. I would collect them from junk tv's and radios primarily because they looked cool. Which being a 5 year old, meant they were eventually taped to wings of toy planes as either missiles, laser cannons or were used as mystical gems for some dumb role play game we were playing.


----------



## droido256

Just got the mk2 amp in wow, and on just the tubes that came with it(not sure what tubes they are) but they sound good. My Sansui SS50 never sounded so alive. How long is the burn in before they get really good?


----------



## HungryPanda

droido256 said:


> Just got the mk2 amp in wow, and on just the tubes that came with it(not sure what tubes they are) but they sound good. My Sansui SS50 never sounded so alive. How long is the burn in before they get really good?


 
 Glad you like it, it is a great little amp. Just wait till you try other tubes. I never count the burn in hours as I'm always too busy enjoying my music


----------



## WilliamLeonhart

I think burn-in should take about 20 - 100 hours depending on tubes, but practically all my tubes sound good from the start and even my less fav tubes, Siemens and Voshkhods (no rocket logo) improve with time.
  
 Currently I have 7 pairs of EF95 tubes to run with my I+. So it'll take dozens of years for them to run out. That, unless I find a pre-amp that uses EF95 too.


----------



## IvoTaze

gibosi said:


> I am quite sure that when these were manufactured they had rhodium pins. And it is important to remember that the plating on the pins, whether gold or rhodium, has absolutely no affect on the sound. These platings were applied because they are resistant to corrosion, and never having to clean pins is a very good thing.
> 
> However, there is something about gold pins that causes people to go a little crazy... lol. And while I have no proof, I believe that when you see Voskhods with gold pins, that plating was not done at the factory. Likely, it was done sometime after production, perhaps many years after, And very likely it was done in order to justify a higher selling price to audiophiles, such as those in this forum. lol.
> 
> Regardless, Voskhod 6ZH1P with gold pins are not worth the extra cost. I consider them to be a novelty and a collectors item. If you are simply looking for a pair of Voskhods for your amp go for the inexpensive ones with rhodium pins.


 
  
 And what do you guys think about these ones from 1979? For some reason the stamps on the boxes look too new... 
  
 http://www.ebay.com/itm/6J1P-EV-6ak5-EF95-USSR-1979-Lot-of-4-pcs-/172091890525?hash=item281179db5d:g:OjcAAOSwnLdWtmOg
  
 Thanks once more


----------



## gibosi

ivotaze said:


> And what do you guys think about these ones from 1979? For some reason the stamps on the boxes look too new...
> 
> http://www.ebay.com/itm/6J1P-EV-6ak5-EF95-USSR-1979-Lot-of-4-pcs-/172091890525?hash=item281179db5d:g:OjcAAOSwnLdWtmOg
> 
> Thanks once more


 
  
 It really depends on how they have been stored. If there were stored in a temperature and humidity-controlled environment all these years, the boxes would still look new. I have some boxes from the 1940's that look and feel new.


----------



## droido256

Wow, the Raytheon CK5654 sound wonderful!


----------



## droido256

Decided to pull the trigger on a 4x set of GE's ....... I think i have succumbed to valve sickness  4 GE's, 10 Voshkods, 7 Raytheons. 

Excuse me, I have to comfort my crying wallet. 

Nevermind, the wallet has burnt to a crisp.


----------



## HungryPanda

droido256 said:


> Decided to pull the trigger on a 4x set of GE's ....... I think i have succumbed to valve sickness  4 GE's, 10 Voshkods, 7 Raytheons.
> 
> Excuse me, I have to comfort my crying wallet.
> 
> Nevermind, the wallet has burnt to a crisp.


 
 yep you will soon have a drawer or box full of tubes


----------



## gulakpi

hungrypanda said:


> yep you will soon have a drawer or box full of tubes


 
  
 ............ like most of us!  Haha~!


----------



## droido256

Besides the 5654 are there any other Ratheon tubes that work with the mk2 amp? Including power tubes? I really like the Raytheon "sound".

Meanwhile my wallet is going no! No!


----------



## XSAMURAI

has anybody tried Electro-Harmonix 6H30Pi Gold Pins with GE jan 5654w ? i'm using stock power tube with 5654w but today i ordered Mullard M8100 & Voshkod 6ZH1P and i want change my power tubes , any suggestion about power tubes ? EH 6H30Pi Gold pins compare to russian 6H6P , is EH worth the extra money ?


----------



## MIKELAP

xsamurai said:


> has anybody tried Electro-Harmonix 6H30Pi Gold Pins with GE jan 5654w ? i'm using stock power tube with 5654w but today i ordered Mullard M8100 & Voshkod 6ZH1P and i want change my power tubes , any suggestion about power tubes ? EH 6H30Pi Gold pins compare to russian 6H6P , is EH worth the extra money ?


 
  I have the Electro Harmonix($75.00/pair approx.) i also have the Russian 6N6P-IR $25.00/PAIR personnally i prefer the 6N6P-IR                          http://www.ebay.com/itm/171310973012?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT


----------



## spiderking31

xsamurai said:


> has anybody tried Electro-Harmonix 6H30Pi Gold Pins with GE jan 5654w ? i'm using stock power tube with 5654w but today i ordered Mullard M8100 & Voshkod 6ZH1P and i want change my power tubes , any suggestion about power tubes ? EH 6H30Pi Gold pins compare to russian 6H6P , is EH worth the extra money ?


 I have a few pairs of Sovtek 6n30pi's, and i think that their definitely worth the extra few dollars that you'll pay for them  It depends on this. Are you using high impedance headphones? 300 ohms? Or even 600 ohms?? 300 ohm headphones aren't going to sound dramatically better. I have the Beyerdynamic DT990 600 ohm, and I find the Sovtek's to really make them sing (500mw per tube). I also have the Beyerdynamic Tesla T1.2 and those really sing! I also have the Sennheiser HD650's. All of my headphones sound amazing with the Sovtek power tubes. But the reason why I went with a more powerful tube (Sovtek) was because of the use of my DT990's. Also, for you to go with the gold pin 6n30pi's (DR version) is crazy! $100 USD per tube?!?! I paid $70 USD for a pair of the EV versions  They're just as good. IMHO anyways  And you'll save $130 on a pair


----------



## XSAMURAI

spiderking31 said:


> I have a few pairs of Sovtek 6n30pi's, and i think that their definitely worth the extra few dollars that you'll pay for them  It depends on this. Are you using high impedance headphones? 300 ohms? Or even 600 ohms?? 300 ohm headphones aren't going to sound dramatically better. I have the Beyerdynamic DT990 600 ohm, and I find the Sovtek's to really make them sing (500mw per tube). I also have the Beyerdynamic Tesla T1.2 and those really sing! I also have the Sennheiser HD650's. All of my headphones sound amazing with the Sovtek power tubes. But the reason why I went with a more powerful tube (Sovtek) was because of the use of my DT990's. Also, for you to go with the gold pin 6n30pi's (DR version) is crazy! $100 USD per tube?!?! I paid $70 USD for a pair of the EV versions  They're just as good. IMHO anyways  And you'll save $130 on a pair


 
 i forgot to mention , i'm using mk 2 not 3 , and i have different headphone from low impedance to high , but most of the time using with headphones around 150 to 300 ohm , and maybe with some planars


----------



## spiderking31

xsamurai said:


> i forgot to mention , i'm using mk 2 not 3 , and i have different headphone from low impedance to high , but most of the time using with headphones around 150 to 300 ohm , and maybe with some planars


Here's the question. Is the MK2 OTL? Or hybrid? Also, I very much doubt that you can use the 6n30pi's


----------



## HungryPanda

OTL for sure


----------



## HungryPanda

dip switches for changing the family sets


----------



## spiderking31

hungrypanda said:


> OTL for sure


Awesome  your amp is best for high impedance headphones 300-600 ohms Planars aren't going to be best with your mk2


----------



## XSAMURAI

spiderking31 said:


> Awesome  your amp is best for high impedance headphones 300-600 ohms Planars aren't going to be best with your mk2


 
 that's right it's otl , what is your suggestion ?


----------



## spiderking31

xsamurai said:


> that's right it's otl , what is your suggestion ?


Stick with your 6h6n's. They're great tubes for running headphones like the Sennheiser HD6xx. If your going to run your Planars, I would check out www.schiit.com for an amp that's a hybrid (if you still crave that tube sound), or go solid state. That's what you need for your Planars. BUT, a hybrid amp will be superb with your Planars, as well as your high impedance headphones as well  With Schiit Audio, you're sure to find an amp that'll fit your budget, and preferences


----------



## TrollDragon

xsamurai said:


> i forgot to mention , i'm using mk 2 not 3 , and i have different headphone from low impedance to high , but most of the time using with headphones around 150 to 300 ohm , and maybe with some planars


 

 I run the T50RP's on my MK IV perfectly as well as the DT880's.


----------



## spiderking31

trolldragon said:


> I have an updated revision on my MK3 circuit board, allowing me the 6n30pi power tubes  I'll agree with you for sure, on the performance with your DT880's
> I run the T50RP's on my MK IV perfectly as well as the DT880's.


----------



## droido256

How are the GE 5654? I just got in 8 of them. Currently im using the Raytheon 5654 which are doing fantastic.


----------



## XSAMURAI

spiderking31 said:


> Stick with your 6h6n's. They're great tubes for running headphones like the Sennheiser HD6xx. If your going to run your Planars, I would check out www.schiit.com for an amp that's a hybrid (if you still crave that tube sound), or go solid state. That's what you need for your Planars. BUT, a hybrid amp will be superb with your Planars, as well as your high impedance headphones as well  With Schiit Audio, you're sure to find an amp that'll fit your budget, and preferences


 
 i have some schiit like lyr 2 , magni 2 u ,... the reason i'm looking for the power tube because now i have 3 pair drive tube with stock chinese power tube , and actually i tried  low impdance cans like sony mdr100aap and philips x2 and both sound great with mk 2


----------



## spiderking31

xsamurai said:


> i have some schiit like lyr 2 , magni 2 u ,... the reason i'm looking for the power tube because now i have 3 pair drive tube with stock chinese power tube , and actually i tried  low impdance cans like sony mdr100aap and philips x2 and both sound great with mk 2


I don't think your MK2 can use the 6n30pi's. That's the issue


----------



## TrollDragon

The LD MK II v2.0 board supports the 6Н30П tubes without modification. You would have to gauge the cost vs a minimal sound upgrade.
 http://littledot.net/forum/viewtopic.php?t=431


----------



## XSAMURAI

I have a question about Mullard M8100 & Voshkod 6ZH1P-EV . Do I need to change the switch settings from the factory installed tubes ? using GE JAN5654W and Stock Power Tubes on MK 2


----------



## MIKELAP

xsamurai said:


> I have a question about Mullard M8100 & Voshkod 6ZH1P-EV . Do I need to change the switch settings from the factory installed tubes ? using GE JAN5654W and Stock Power Tubes on MK 2


 
 Check out page #1


----------



## spiderking31

xsamurai said:


> I have a question about Mullard M8100 & Voshkod 6ZH1P-EV . Do I need to change the switch settings from the factory installed tubes ? using GE JAN5654W and Stock Power Tubes on MK 2


No. You're fine with the Mullards and the Voshkods. No need to worry about the jumpers. Those two are used in EF95 configuration


----------



## muscleking

hi guys
 i have a MKIII arriving tomorrow. also got some 6ZH1P-EV and 6HM5 coming later. 
  
 will be using this with my new T1 2nd generation, which sound pretty bad through STX directly, compared to stax 4170 that is. 
  
 i will also try hooking up the MKIII as a "preamp" to the stax 006ts amplifier. is that how preamp works? connect an amp to another amp?
  
 just checking in before i mess up anything. 
  
 anybody have the T1 2nd with MKIII and how do you like it? i read that Beyerdynamic is bad with MKIII. but that person didn't mention tube rolling. 
  
 looks like i will be changing tubes a lot too, relatively cheap compare with buying selling camera lenses which i got out of that hobby now. the last time an audio wow'ed me was changing from onboard to STX sound card with DT1350 headphones. which i never heard from a sound card before. after that nothing really shock me that much. even from a sony ma900 to STAX 4170. right now i feel the sony ma900 sounds better from the STX than the T1 2nd, which doesn't really make sense. so that's why i got the MKIII. also tried o2 and odac. didn't notice any difference compared to stx so i sold it a long time ago. i think the ma900 is very warm maybe that's the sound i like. so hopefully everything works out. i will report back after i receive the MKIII.
  
 just some researched showed there are a notched 6ZH1P-EV and smooth glass one. people have different preferences. from all the ebay tube pictures there are 3 notches on the tubes. pretty sure that's the one i will receive. guess like everyone else i won't find out what i like until i try different things. something to keep me busy on my free time reading these tubes.
  
 oh also the MKIII been around for like 8 years or more? i see people mention this in 2007. so i should receive version 4 board.


----------



## gulakpi

muscleking said:


> hi guys
> i have a MKIII arriving tomorrow. also got some 6ZH1P-EV and 6HM5 coming later.
> 
> will be using this with my new T1 2nd generation, which sound pretty bad through STX directly, compared to stax 4170 that is.
> ...


 
  
  
 Are you trying to connect a headphone amp to another headphone amp?? 
  
 The Stax 006ts is a DC amp, and on the Mk3 manual, it recommends against connecting to another amplifier with a DC input stage.


----------



## gulakpi

The 6HM5 is still one of my favorites!


----------



## MIKELAP

gulakpi said:


> muscleking said:
> 
> 
> > hi guys
> ...


 
 page 188 post # 2811 i had asked about this awhile back and i couldnt use my Pioneer SX750 with LDMK3 as preamp                                         http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/2805#post_9781377


----------



## muscleking

gulakpi said:


> Are you trying to connect a headphone amp to another headphone amp??
> 
> The Stax 006ts is a DC amp, and on the Mk3 manual, it recommends against connecting to another amplifier with a DC input stage.


 
 sounds good. thanks guys. i will use it strictly for the dynamic headphones. didn't arrive yesterday. so hopefully today. the 6HM5 is cheap. 15 USD shipped for a matched pair on ebay. not gonna buy anything for a while after this.


----------



## J Mirra

I have the T1.1 and a LDmk2 with the mullard 8100 and 6N6P-IR and it sounds so good.
  
 Like you I have the Asus xonar st and its night and day difference.
  
 So thats Xonar outs to the LD, the tubes in the LD make all the difference.


----------



## muscleking

good to hear. i been refreshing the dhl tracking throughout the day and it's still in the local sorting delivery facility. lol times goes slowly waiting for this thing. definitely get the cv4010 later. and the IR power tube. plenty available online so not too big rush.


----------



## muscleking

so received the MKIII yesterday and played with it for an hour only. yeah it's noticable difference vs no amp and stax 4170. i actually like the MKIII with T1.2 better. it's like a much fuller sound and i actually hear some more those background sounds being amplified more than stax. the stock tubes are both warm and some bright recordings are still a bit bright. so the yugoslovian and russian blue rocket tubes are on their way so will share some thoughts after. very well made piece of professional equipment. great size too, for the amplifier. 
  
 can someone recommend a good quality "tube saver" since i will be changing tubes for a bit and don't want to damage the stock base tube socket. i have trouble pull the tubes straight up, it's pretty tight. have to jiggle it a little to take it out. is that ok? but i can see getting a socket extender will help. 
  
 oh and highly recommended everyone to get the MKIII, i can see the value for money product this thing is. i'll try burn in both more the headphone only has 4 hours or so and the tubes 1 hour. long way to go.


----------



## MIKELAP

muscleking said:


> so received the MKIII yesterday and played with it for an hour only. yeah it's noticable difference vs no amp and stax 4170. i actually like the MKIII with T1.2 better. it's like a much fuller sound and i actually hear some more those background sounds being amplified more than stax. the stock tubes are both warm and some bright recordings are still a bit bright. so the yugoslovian and russian blue rocket tubes are on their way so will share some thoughts after. very well made piece of professional equipment. great size too, for the amplifier.
> 
> can someone recommend a good quality "tube saver" since i will be changing tubes for a bit and don't want to damage the stock base tube socket. i have trouble pull the tubes straight up, it's pretty tight. have to jiggle it a little to take it out. is that ok? but i can see getting a socket extender will help.
> 
> oh and highly recommended everyone to get the MKIII, i can see the value for money product this thing is. i'll try burn in both more the headphone only has 4 hours or so and the tubes 1 hour. long way to go.


 
 Try a rubber finger just slip it on and pull, its non slip works great


----------



## gulakpi

muscleking said:


> can someone recommend a good quality "tube saver" since i will be changing tubes for a bit and don't want to damage the stock base tube socket. i have trouble pull the tubes straight up, it's pretty tight. have to jiggle it a little to take it out. is that ok? but i can see getting a socket extender will help.
> 
> oh and highly recommended everyone to get the MKIII, i can see the value for money product this thing is. i'll try burn in both more the headphone only has 4 hours or so and the tubes 1 hour. long way to go.


 
  Don't worry about damaging the stock base tube sockets if you pull and insert the tubes normally.  I did it hundreds of times and the LD sockets seem rugged.  They are still as good as new.
 Worst case, just replace the sockets when they fail.  They are not difficult to replace and you have a shorter signal path without the socket savers.


----------



## frogmeat69

mikelap said:


> Try a rubber finger just slip it on and pull, its non slip works great


 
 Where did you get the cages for the tubes?


----------



## MIKELAP

frogmeat69 said:


> mikelap said:
> 
> 
> > Try a rubber finger just slip it on and pull, its non slip works great
> ...


 
 Those i made myself ,you can buy here but there is different inside diametre and lenghts read description to see if they are good for you                                                   http://www.ebay.com/itm/150628567039?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT


----------



## frogmeat69

Thanks MIKELAP!!


----------



## muscleking

so with the included 120V 3 pin with ground power cord i get the hissing sound. then i tried the stax 2 pin power cord without the ground round pin and no more hissing sound unless set to 600ohm and max the sound. but for up to like 75% of the volume no hissing sound. wonder why they don't just include a 2 pin power cord which is probably cheaper. the one comes with it is huge thick power cord that looks like for my 1000w computer power supply cable. 
  
 i am looking into chaging the power tubes now while still waiting for the other tubes to come in. stock ones are ok but score only 61/100 like in the beginning of this thread says and the other ones i am getting are 95/100. so i sure hope it makes difference. so for the power tube is the 6n6p-IR significantly better in sound  than the stock 6n6p?


----------



## TrollDragon

muscleking said:


> so with the included 120V 3 pin with ground power cord i get the hissing sound. then i tried the stax 2 pin power cord without the ground round pin and no more hissing sound unless set to 600ohm and max the sound. but for up to like 75% of the volume no hissing sound. wonder why they don't just include a 2 pin power cord which is probably cheaper. the one comes with it is huge thick power cord that looks like for my 1000w computer power supply cable.


 

 A non ground power cord is dangerous on a device with a metal chassis. If the AC hot side somehow shorted to ground in the amplifier, the case could become lethal. Not a wise choice putting a non grounded power cord on the amplifier.


----------



## muscleking

ok thank you. I will use the original power cord. doesn't matter where I connect it I will hear buzz.
  
 so like everyone else said get the ground isolator is best choice? I live in older house in the 90s maybe that's why the electrical is not clear.
  
 I tried move away from computer, wifi and connect to same outlet. all have the buzz. only when change to that power cord works.
  
  
  
  


trolldragon said:


> A non ground power cord is dangerous on a device with a metal chassis. If the AC hot side somehow shorted to ground in the amplifier, the case could become lethal. Not a wise choice putting a non grounded power cord on the amplifier.


----------



## bharat2580

Hi there guys. My mark IV SE is on sale, as i can't use it anymore no time.
 link to the sale page.
  
 http://www.head-fi.org/t/801746/little-dot-mkiv-se-ton-of-tubes


----------



## shepperd

A big hand shake for the work involved initially and al the feedback since. I have to confess from the onset that I don't have a little dot! In fact I have never had headphones 
	

	
	
		
		

		
			








. Don't beat me up just yet though. I got a new pre-amp a while ago and it came with those wretched cj1 Chinese tubes. I was looking for better ones and chanced upon this thread. (more like a very long carpet!) I immediately ordered a set of Voshkod 6ZH1P-EV from Yen and then some *GE JAN5654W*. I didn't very much care for the latter. The russian tubes require a lot of patience...120 hrs + as stated. They were far and away the best until...by accident i opened a page at random and chanced upon someone here stating that the Tung Sol FAA-6AH6 were special. Being of a curious nature and disregarding the shrinkage of my wallet I found some (vintagelectrons.com). After about 12 hours running in I was blown away. I couldn't believe my ears and did a comparison test with an audiophile friend to confirm that these indeed are amazing. The only caveat is that they are noisey and tend to be microphonic. I wrote to the store asking if this was typical and if he would send me another pair and check every which way to try and get a quieter set. The Russian tubes are dead quiet, as are the GE. The Tung sols date from 1962, which would place them in the golden age of tubes manufacturing. Whatever the case, I'm grateful for having found a new obsession. Thanks and good hunting. 
 For whatever reason I can only reply to this old post and not start a new one. Anyway I have been bitten by the NOS craze and have to date a dozen pairs of various F95 gleaned from a variety of sources. I have a few more to discover and then I think I will give up the chase for the perfect tube. I will be unloading all the tubes I don't use, which include most of the ones mentioned on this forum and several that no one seems to have tried. I will list them is due course. They all have been run in; generally with 20 to 30 hrs to get a good handle on their characteristics. There are no bad tubes in the bunch, just ones I don't listen to. I have my favorites, which I will not sell and will mention them later. The thing is I only want to send a box full of tubes in europe. I trust people in the audio world so I am quite happy to send them to whoever says "yes I will". Once you have verified the contents you can send me a check or whatever. I dont have a Pay pal acct. or anything else like that. I reckon I have paid around 200 euros for all these but I will let them go for 100plus shipping (which isnt much more than 15 euros from here (France). There are no Mullards or Tungsol but there is a Voshhod and a bunch of crazy rare ones> Since I am ussing them in a tube buffer type pre-amp, your experiences will vary from mine.


----------



## MIKELAP

shepperd said:


> A big hand shake for the work involved initially and al the feedback since. I have to confess from the onset that I don't have a little dot! In fact I have never had headphones
> 
> 
> 
> ...


 
 You said you got your tubes from Yen Audio everybody makes this mistake once lol(over priced) made that mistake also ,and by the way you dont need matched pairs in case you didnt know


----------



## shepperd

I ordered from Yen in good faith, right from the first when I found this topic, because he figured in the "trusted" list on the first page of tube descriptions. I have no complaints; the service was rapid, the tubes well packaged and as described (as indeed have been all the orders I have put thru to other sellers) Regarding pricing; not to be contentious but it is a cut-throat market out there, especially for NOS tubes. The prices for some NOS tubes take one's breath away so I don't in any way feel I've been taken advantage of. I have since found other sources for other variants (especially those divine Tung Sol 62's) and the prices are well within reason. Given the kind of money some us have spend on other parts of out systems (myself included), I find that a pair of tubes of this quality for this price is very reasonable. On the subject of sources, given the length and breadth that members have gone thru, it might be useful to update the original list to include the best (and worst) of sellers: prices, quality/reliability of service. Just a thought...by the way, the microphonics I complained about, regarding the Tung Sol, seems mysteriously to have gone away...go figure. The seller I mentioned was quite happy to take them back and split the shipping costs. I said no way and ordered another set. Yes they are that good. I might try other tubes but I seriously doubt there's any point. Regarding matched pairs: the jury's out on that one. There are two schools of opinion. I like the idea, whether or not it factors into their sound, so I will continue to let myself be tempted 
	

	
	
		
		

		
		
	


	




.


----------



## TrollDragon

shepperd said:


> Regarding matched pairs: the jury's out on that one. There are two schools of opinion. I like the idea, whether or not it factors into their sound, so I will continue to let myself be tempted
> 
> 
> 
> ...


 
 If you amplifier has a class A/B Push/Pull output then you really should have a matched pair of tubes so they both draw the same plate current. That way one tube is not running hotter and wearing out quicker, also it is easier with a matched pair to dial in the sweet spot on the bias for optimum sound.
  
 The matching of preamp tubes is just a way for vendors to grab money from you as none of that applies.
  

 The Little Dot MK II/III/IV(se) amplifiers do not have "Power Tubes" and are not in a push/pull configuration on the output tubes.


----------



## bharat2580

i had harsh sounds (highs were fatiguing, very harsh)  on the 30pi gold and 6hm5 i don't know why on my IV se , now i switched to the ir and ef95 mallards much better. what might have been the problem ??


----------



## muscleking

shepperd said:


> A big hand shake for the work involved initially and al the feedback since. I have to confess from the onset that I don't have a little dot! In fact I have never had headphones
> 
> 
> 
> ...


 
 couldn't help myself after you mention the FAA. so i bought all 6 on ebay lol. i started hording these things now. i can see why people get a lot in the end. brought the 6n6p-IR as well.


----------



## Craig Moorhouse

Just purchased a MD LD MKii - acted to slow to upgrade the tubes - wondering if this soviet era tube set would be a worth while upgrade? 
 http://www.ebay.ca/itm/252290300716?rmvSB=true

 Thank you for your time 
 Craig


----------



## muscleking

craig moorhouse said:


> Just purchased a MD LD MKii - acted to slow to upgrade the tubes - wondering if this soviet era tube set would be a worth while upgrade?
> http://www.ebay.ca/itm/252290300716?rmvSB=true
> 
> Thank you for your time
> Craig


 
 i been reading this blog for like 2 months now. so 
  
 get the 6n6p-ir, 6hm5 yugoslovia, voshkod 6zh1p-ev, to start with those are good.
  
 i used the 6zh1p-ev for like 40 hours didn't notice anything different vs stock and just plug into the sound card directly lol. so i got a bunch more stuff to play around like a m8 dac and some more tubes. still waiting for 6hm5 but that one is universally appraised to be better than stock.


----------



## Acapella11

muscleking said:


> i been reading this blog for like 2 months now. so
> 
> get the 6n6p-ir, 6hm5 yugoslovia, voshkod 6zh1p-ev, to start with those are good.
> 
> i used the 6zh1p-ev for like 40 hours didn't notice anything different vs stock and just plug into the sound card directly lol. so i got a bunch more stuff to play around like a m8 dac and some more tubes. still waiting for 6hm5 but that one is universally appraised to be better than stock.


 
  
 Hi muscleking, that's right - afterwards these with those


----------



## MIKELAP

acapella11 said:


> muscleking said:
> 
> 
> > i been reading this blog for like 2 months now. so
> ...


 
 Saw these seemed better made .Hey man long time no see


----------



## Acapella11

mikelap said:


> Saw these seemed better made .Hey man long time no see


 
  
 Hi Mikelap, thanks, good to hear back from you mate!


----------



## Acapella11

bharat2580 said:


> i had harsh sounds (highs were fatiguing, very harsh)  on the 30pi gold and 6hm5 i don't know why on my IV se , now i switched to the ir and ef95 mallards much better. what might have been the problem ??


 
  
 Regular 6H30P are not the most amazing power tubes and 6HM5 like to show their treble, even though well presented


----------



## muscleking

I received my 6hm5 yesterday and one tube has this bright dot and no sound from that one, I tried switch side and made opposite channel not work. The other tube is fine glows orange like my other tubes. Seller is fantastic and will send me replacement. Anybody knows what this is? See picture. Put back the 6j1p-ev and no problem. It's set to EF95 so should be fine. Again one tube works perfectly.


----------



## gulakpi

Looks like these are the tall bottles -- the right type!


----------



## Planner

Hi,
  
 I'm sorry for this noob question, cuz I'm a newbie with tubeamps. Do you guys have the information or personal reviews of this Little Dot 1 (6 tubes)?
  
 This one


----------



## gibosi

It would appear that this is the very first Little Dot, introduced in 2004. From the chart linked to below, it uses 2P3 for output and 1B2 for drivers. I have never seen this amp and consequently have no experience with it.
  
 http://www.head-fi.org/t/355789/list-of-little-dot-amps#post_4638237


----------



## SomeGuyDude

Funny thing is it would have taken fewer keystrokes to just answer.


----------



## Planner

gibosi said:


> It would appear that this is the very first Little Dot, introduced in 2004. From the chart linked to below, it uses 2P3 for output and 1B2 for drivers. I have never seen this amp and consequently have no experience with it.
> 
> http://www.head-fi.org/t/355789/list-of-little-dot-amps#post_4638237


 
 Thank you so much for the link. This is really helpful.


----------



## WilliamLeonhart

It looks fun. Mesa wants it


----------



## shepperd

http://www.ebay.com/itm/2x-Matched-1957-Tesla-6F32-D-getter-vacuum-tubes-EF95-6AK5/112052765296?_trksid=p2047675.c100009.m1982&_trkparms=aid%3D888007%26algo%3DDISC.MBE%26ao%3D1%26asc%3D38530%26meid%3Dcdb41a85e1c14c0fa26398e4bd65f75a%26pid%3D100009%26rk%3D1%26rkt%3D1%26sd%3D252230073367
  
 I chanced upon the discussion relating to two types of these Tesla's; the one with the white hat and white lettering supposed to be the best. Any opinions as to whether the above are just mixed or worth the try?


----------



## shepperd

http://www.ebay.com/itm/2x-Matched-Voskhod-Gold-pins-Gold-grid-6ZH1P-EV-6AK5-EF95-403B-5654-6J1-1977-NIB/131446387039?_trksid=p2047675.c100009.m1982&_trkparms=aid%3D888007%26algo%3DDISC.MBE%26ao%3D1%26asc%3D20131227121020%26meid%3D6667defeb05742c8a7ba84595932fa43%26pid%3D100009%26rk%3D2%26rkt%3D2%26sd%3D112052765296
  
 likewise: I seem to recall reading here that the so-called gold pins was not original but an aftre-maket job. I have a pair of these (non gold pinned) from 81". These are earlier. Any difference in sound? I was not entirely convinced, especially after finding the Tung Sol's. The hunt goes on!


----------



## SomeGuyDude

shepperd said:


> http://www.ebay.com/itm/2x-Matched-Voskhod-Gold-pins-Gold-grid-6ZH1P-EV-6AK5-EF95-403B-5654-6J1-1977-NIB/131446387039?_trksid=p2047675.c100009.m1982&_trkparms=aid%3D888007%26algo%3DDISC.MBE%26ao%3D1%26asc%3D20131227121020%26meid%3D6667defeb05742c8a7ba84595932fa43%26pid%3D100009%26rk%3D2%26rkt%3D2%26sd%3D112052765296
> 
> likewise: I seem to recall reading here that the so-called gold pins was not original but an aftre-maket job. I have a pair of these (non gold pinned) from 81". These are earlier. Any difference in sound? I was not entirely convinced, especially after finding the Tung Sol's. The hunt goes on!


 
  
 The gold shouldn't really affect the sound per se, it's just a matter of connection.


----------



## TrollDragon

someguydude said:


> The gold shouldn't really affect the sound per se, it's just a matter of connection.


 

 He didn't mean that the gold pins would change the sound.
 The gold or non gold pins sometimes define different manufacturers, tube vintage or internal design which does impact the sound.


----------



## shepperd

"*The first grid is wound with wire made of an alloy of gold and platinum." I *was wondering more about this than the pins. The first set of these tubes I bought made no mention of either gold or platinum. These appear to be from a few years earlier. Having no luck finding the Tung Sols, I have turned my attention elsewhere and ordered a pair of Tesla vintage 57' A bit pricey but I found only one seller on the net. I'll report back on these when I get them. (I never thought I would catch the tube rolling bug!!!)


----------



## shepperd

For those of you with deep pockets or just curious, This caught my attention: http://vinylsavor.blogspot.fr/2016/09/news-from-elrog-tube-factory.html


----------



## muscleking

Just received these but i researched first and I need to either use a jumper on pin 2 and 7 or I can get adapter. I think adapter is easier. I didn't find links for adapter, does anyone knows what adapter I need? Im in a small town so it's easier to order stuff online. I don't mind spend a little to get 2 adapters vs buying wires and cut and risk mistake.


----------



## TrollDragon

muscleking said:


> Just received these but i researched first and I need to either use a jumper on pin 2 and 7 or I can get adapter. I think adapter is easier. I didn't find links for adapter, does anyone knows what adapter I need? Im in a small town so it's easier to order stuff online. I don't mind spend a little to get 2 adapters vs buying wires and cut and risk mistake.


 

 I doubt you will find a commercially made 6AH6 to EF95 adapter.
 You will probably have to DIY one or just use the straps like we all did when we were testing out those tubes.

 I soldered permanent straps on my Tungsol 6AH6WA's.


----------



## shepperd

This tube is a driver tube of the F95 family, not a power tube so I am curious why it should need an adapter. How are you using it may I ask? By the way, if these are the 62' Tung sols, like I bought, they are wonderful (at least in my pre-amp) If for some reason you don't like them I would happily take a pair off you!


----------



## muscleking

thank you.
  
 what happens if you don't use that jumper and would the whole thing catch fire? not gonna do it just interested to know what it would do. also i can keep EF95 once i put a jumper on like that?
  
 thanks for the picture i understand what to do now. now just need to find that wire. just some copper computer cable wire is good from those computer fans? too bad i sold my soldering machine so i have to maybe super glue it


----------



## muscleking

shepperd said:


> This tube is a driver tube of the F95 family, not a power tube so I am curious why it should need an adapter. How are you using it may I ask? By the way, if these are the 62' Tung sols, like I bought, they are wonderful (at least in my pre-amp) If for some reason you don't like them I would happily take a pair off you!


 
 yeah i think it was you who posted how good it is so i just snatched it off ebay the remaining 6. probably the same seller you got from. the box for these fall apart so easily. over 50 years old i feel it's real antique. i will try it in preamp and amp. i have a standalone solid state amp the SMSL VA2. hooks up nicely downstream with the little dot mk III which is what i use.


----------



## shepperd

So it was you! grrr. Anyway I hope you enjoy them. I am trying out another tube (on the way from far off lands) but for the moment I'm not saying a word about it because it's even rarer (and older!)


----------



## gibosi

shepperd said:


> This tube is a driver tube of the F95 family, not a power tube so I am curious why it should need an adapter. How are you using it may I ask? By the way, if these are the 62' Tung sols, like I bought, they are wonderful (at least in my pre-amp) If for some reason you don't like them I would happily take a pair off you!


 
  
 The 6AH6 and the 6AK5 have different pin-outs. And therefore, the 6AH6 cannot be used in the LD without some sort of an adapter.
  


muscleking said:


> what happens if you don't use that jumper and would the whole thing catch fire? not gonna do it just interested to know what it would do. also i can keep EF95 once i put a jumper on like that?
> 
> thanks for the picture i understand what to do now. now just need to find that wire. just some copper computer cable wire is good from those computer fans? too bad i sold my soldering machine so i have to maybe super glue it


 
  
 Nothing bad will happen if you don't use an adapter. But then again, nothing good will happen either. lol 
  
 Super glue is not a good conductor, so it might not work all that well....  In my opinion, the easiest way is to insert short pieces of very small gauge *stranded* wire into the socket holes as described earlier in this forum.


----------



## MIKELAP

muscleking said:


> thank you.
> 
> what happens if you don't use that jumper and would the whole thing catch fire? not gonna do it just interested to know what it would do. also i can keep EF95 once i put a jumper on like that?
> 
> thanks for the picture i understand what to do now. now just need to find that wire. just some copper computer cable wire is good from those computer fans? too bad i sold my soldering machine so i have to maybe super glue it


 
    Left picture give you a good idea where the wire goes very small wire as was said


----------



## dbaker1981

So the Mki+ uses the same 6ak5 tubes as the mkiii? I'm looking for a cheaper tube hybrid to use as a bed setup and if they use the same it would work out great.


----------



## gibosi

dbaker1981 said:


> So the Mki+ uses the same 6ak5 tubes as the mkiii? I'm looking for a cheaper tube hybrid to use as a bed setup and if they use the same it would work out great.


 
  
 The current Little Dot 1+, MK II, MK III and MK IV, all of them, can use 6AK5 (EF95), EF91 and EF92 as driver tubes. Further, the LD 1+ can also use 408A as well.
  
 The Little Dot MK I+ is a portable, solid-state amp, so no tubes.


----------



## dbaker1981

gibosi said:


> The current Little Dot 1+, MK II, MK III and MK IV, all of them, can use 6AK5 (EF95), EF91 and EF92 as driver tubes. Further, the LD 1+ can also use 408A as well.
> 
> The Little Dot MK I+ is a portable, solid-state amp, so no tubes.




Ah gotcha. Had the wrong model name. Thank you.


----------



## muscleking

Got the faa 6ah6 working. Yeah right away it's huge improvement over the vishkod. It's so natural and no more ssss sound to all vocals. I can turn volume loud and no ear fatigue. I only tried it at work using the dt1350.the tube runs super hot. The vishkod I can still put fingers on it at the end of day. Also this tube is quieter on the ground loop, but I can hear myself touching the headphone cable and even turn dial will get picked up. Only can hear those when music is paused. I will run these for 12 hours like the other guy said and see what happens. Very cool looking tubes.a lot more complicated inside than other tubes. 
	

	
	
		
		

		
			





[/IMG]


----------



## muscleking




----------



## shepperd

The other guy...that would be me...Mine don't run hot but then they are not being driven hard. This is a fabulous tube. Yes 12 hours is about what it took for them to bloom. I still haven't received my other, mystery tubes.If they are better or different than the tung sols (hard to imagine) I will report (after buying every available one this time!!!!)


----------



## shepperd

ps mine were very microphonic and hissy for the first 15 hours or so, then they miraculously stopped doing that.


----------



## muscleking

mine is not hissy, even without ground loop correction. but the smsl m8 + P1 is very quiet. mine just if you use finger tap on the tube you can hear it in the headphone. even turning dial when touching it I can hear it in headphone. my headphone is closed so it is definitely passed on from the tube. guess that's what vacuum does.
  
 my new hobby = finding rare tube and buy it all up.... PRICELESS.
  
 lol. I think I am done buying tubes. I wonder if the newer more available 6AH6 sounds similar to this 1962 FAA. somehow the military stuff sounds better. also you said 60s is the best. so that's the starting point for future tubes.
  
 I will take the little dot home with the m8 this weekend and run it on the beyer t1.2, also got a Philips shp9500 today in mail. then a month later i'll go to my other home to pick up the sony ma900.
  
 it would be interesting to run this setup I have with the little dot on stax electrostatic phones. but too bad can't connect to the stax vacuum tube amp.
  
 overall, the little dot is a fun amazing well built and yet affordable way to enjoy the audio hobby. now just need to find some better headphone to replace the DT1350 which I had for so many years. can't be this one for office. the isolation is world class.
  
 I am still waiting for the Yugo 6hm5 replacements. I think something about "tall bottles" sounds better. more volume is better. oh I still have the IR power tubes coming. infinite combinations. so fun.


----------



## shepperd

actually i meant tube rush when putting your ear near the tweeter (I guess headphones are just as revealing) The art of making tubes, other then for the marginal audio field, pretty much dies out in the 80's and 90's etc. Factories closed, skilled workers retired or died or went elsewhere. It takes time and the willingness to retool and retrain and some of the skills learned will be hard to duplicate.
 NOS, and old tubes in general, were made in the days when tubes were king and had to be well made and consistent, especially for the military. Most of the tubes used in audio have no application elsewhere anymore so it's a very specialist type of manufacturing and a lot more expensive than back in the day. Fortunately there are still tons of tubes to be found in all sorts of places and since they keep for a very long time, buying ones from 40 or more years ago is a safe bet. Other than some fearfully expensive types, these old tubes generally sound the best. It is wise to stock up (a bit) since once in use they do have a limited life span, even though in some cases that can be years, and the law of supply and demand means the prices can only go up unfortunately. These Tung Sol tubes we bought probably cost less than a dollar back then......there are videos about how tubes are made. It really is quite a demanding process.


----------



## muscleking

just by looking at these tubes and knowing it's made by hand. that's a lot of work. lots of little soldering work. yeah I will check some videos. I always love antique stuff so it's great I can use antique stuff in modern stuff. a dollar back then is a lot of money lol.
  
 I stay tuned to see what other tube you find next. every morning I turn the system on and it surprise me how good it is. but after 5 hours of listening I take it for granted a bit.
  
 how are these little dot driving orthodynamics? those are the only type of headphone I haven't tried. I am craving for some hit in the face type of bass now. but not like beats.
  
 things back then were much better made than today. hopefully the little dot and the m8 dac last me at least 10 years Im happy.


----------



## TrollDragon

muscleking said:


> how are these little dot driving orthodynamics? those are the only type of headphone I haven't tried. I am craving for some hit in the face type of bass now. but not like beats.


 
 My MK IV does a good job driving my T50RP's.


----------



## muscleking

nice headphone stand. that is some real DIY. interesting you get the two driver tube into one of those black tube. I saw those on ebay. tubes are taking so many different shapes.


----------



## shepperd

My 62" Tungsol 6AH6 suddenly went horribly microphonic. Anyone else have this experience or a cure? I am awaiting some old Tesla's, with the white hat I think, but I doubt they will sound better than the Tung sols. I have read many pages of this thread and am getting a bit lost I confess! Would it be possible to list all the tubes in the F95 family that have been discovered since the original list? Oh and I have a question for the experts; what is the difference between the D and the F versions of the Tesla?


----------



## MIKELAP

shepperd said:


> My 62" Tungsol 6AH6 suddenly went horribly microphonic. Anyone else have this experience or a cure? I am awaiting some old Tesla's, with the white hat I think, but I doubt they will sound better than the Tung sols. I have read many pages of this thread and am getting a bit lost I confess! Would it be possible to list all the tubes in the F95 family that have been discovered since the original list? Oh and I have a question for the experts; what is the difference between the D and the F versions of the Tesla?


 
 Have you checked page 77 there all there


----------



## shepperd

Thanks. It was easy to overlook...there are a lot of pages! That list is a bit bewildering but I will soldier thru it. Since I am using the F95 as preamp driver tubes, some of those probably are not compatible. As it is, there are still enough choices to make me crazy and just a bit poorer. I am on the lookout for another seller of the Tungsol 6485, as they clearly best the Vosktod and don't require a really tiresome lengthy break in.After 10-12 hours they come on song. I am intensely curious about the Tesla's that should be in the mailbox today. Quality control? Sound? Hopefully 57' was a vintage year.
 ps I still don't know the difference between the D,V and F versions of this Tesla tube.


----------



## muscleking

shepperd said:


> My 62" Tungsol 6AH6 suddenly went horribly microphonic. Anyone else have this experience or a cure? I am awaiting some old Tesla's, with the white hat I think, but I doubt they will sound better than the Tung sols. I have read many pages of this thread and am getting a bit lost I confess! Would it be possible to list all the tubes in the F95 family that have been discovered since the original list? Oh and I have a question for the experts; what is the difference between the D and the F versions of the Tesla?


 

 mine yesterday I had it on for over 10 hours hooked up to a speaker and set to high impedance and it got pretty hot. the 62's 6ah6 is hot to the touch and when I change back to the T1.2 headphone it is pouring with warmth. not sure if this is the "tube sound" but it's a big different when I use solid state right after. but overall it's pretty quiet nothing more than the MKIII's ground loop sound. mine is about over 20 hours now. again any vacuum tube if you tap my finger on it you can hear the glass sound. not sure why but fun to play with sometimes.


----------



## WilliamLeonhart

Is there any particular thing you must pay attention to when using the mk3 or mk4? My steps are like this: turn on the amp at 0 volume and no headphones plugged in, let it warm, plug in hp and turn up the volume. Is that ok?


----------



## frogmeat69

williamleonhart said:


> Is there any particular thing you must pay attention to when using the mk3 or mk4? My steps are like this: turn on the amp at 0 volume and no headphones plugged in, let it warm, plug in hp and turn up the volume. Is that ok?


 

 The manual recommends you only plug / unplug your headphones when the Little Dot is powered off.
  
 EDIT: Seems from what others have said, the manual is not right. Thanks to TrollDragon, MIKELAP and gibosi for being the great help around here they always are!!


----------



## wwmhf

williamleonhart said:


> Is there any particular thing you must pay attention to when using the mk3 or mk4? My steps are like this: turn on the amp at 0 volume and no headphones plugged in, let it warm, plug in hp and turn up the volume. Is that ok?


 
 For MK4, putting the volume to 0 when plugging in or out the headphone is better; otherwise, you will hear pop/click in the phones.


----------



## TrollDragon

williamleonhart said:


> Is there any particular thing you must pay attention to when using the mk3 or mk4? My steps are like this: turn on the amp at 0 volume and no headphones plugged in, let it warm, plug in hp and turn up the volume. Is that ok?


 

 On my MK IV I always turn the amp on and let it warm up first (a few minutes), then I check the volume is at 0 and plug in my headphones.
 When shutting down, I turn the volume to zero, unplug the headphones and power off the amp.

 I have done it this way since day one with the MK IV.


----------



## bharat2580

trolldragon said:


> On my MK IV I always turn the amp on and let it warm up first (a few minutes), then I check the volume is at 0 and plug in my headphones.
> When shutting down, I turn the volume to zero, unplug the headphones and power off the amp.
> 
> I have done it this way since day one with the MK IV.


 

 i think its good to have a load during start up and turn-off, and LD recommends the same. high impedance cans like the 600 & 650 are great for that. a 16 ohms load might not be the best though but the 300 works. 
  
 these things are not 100% accurate so during turn on and turn-off it helps to have a high imp load to absorb some of the leaked power. else its building up and amped.


----------



## MIKELAP

bharat2580 said:


> trolldragon said:
> 
> 
> > On my MK IV I always turn the amp on and let it warm up first (a few minutes), then I check the volume is at 0 and plug in my headphones.
> ...


 
 I agree with TrollDragon never turn an OTL  amp on or off with HP plugged in since the LITTLEDOT MK3 is an OTL amp I own a Woo Audio2 which is an OTL amp and this is also recommended by Jack Woo. and for my WA22 which is a TRANSFORMER COUPLED amp HP need to be plugged in


----------



## bharat2580

mikelap said:


> I agree with TrollDragon never turn an OTL  amp on or off with HP plugged in since the LITTLEDOT MK3 is an OTL amp I own a Woo Audio2 which is an OTL amp and this is also recommended by Jack Woo. and for my WA22 which is a TRANSFORMER COUPLED amp HP need to be plugged in


 
  
 well
  
 the mk IV manual says this


----------



## stoke1863

Just got a used little dot mk2 with matched Russian 6N6P+6J1P-EV 

I'm a complete novice how are these rated ? Should I be looking to try something else


----------



## HungryPanda

stoke1863 said:


> Just got a used little dot mk2 with matched Russian 6N6P+6J1P-EV
> 
> I'm a complete novice how are these rated ? Should I be looking to try something else


 

 That is a great start


----------



## gibosi

bharat2580 said:


> i think its good to have a load during start up and turn-off, and LD recommends the same. high impedance cans like the 600 & 650 are great for that. a 16 ohms load might not be the best though but the 300 works.
> 
> these things are not 100% accurate so during turn on and turn-off it helps to have a high imp load to absorb some of the leaked power. else its building up and amped.


 
  
 Transformer-coupled amps require a load when turned on or off. If they are not loaded, the amp can be damaged. On the other hand, OTL (Output Transformer-Less) amps do not need a load. You can run them for hours and hours with no load and with no worries.
  
 And in fact, as pointed out by Mikelap and TrollDragon, when using an OTL amp, the best practice is to make sure the headphones are disconnected before turning the power on and off. The reason for this is that output tubes often fail at the time power is turned on and off. Keep in mind, your headphones are connected directly to the plates of the output tubes. There is nothing in between. If they were to short out, they can damage your headphones. And they can damage your ears. So it really comes down to safety. Following this advice protects your ears and your headphones. And again, the amp doesn't care one bit if the headphones are plugged in when it is turned on and off.
  
 All that said, the output tubes used in the LDs are pretty puny, so perhaps if they do fail at startup, no harm will be done. But still, better safe than sorry. Therefore, I encourage anyone who has an OTL amp to wait a few minutes for the output tubes to reach normal operating temperature and stabilize before plugging in the headphones. And don't put them on your ears until after they are plugged in! And then again, when shutting down, disconnect the headphones first.
  
 Protect those expensive headphones, and especially, protect your ears. Be safe!


----------



## stoke1863

Wondering if someone could help.
  
 Got a used MKII with 6N6P+6J1P-EV tubes.
  
 I can barely tell a difference when comparing the sound vs my Solid State amp also not much difference with my ears to the stock tubes.
  
 What would be best combo for a more tubey sound? Or are my ears just broken?


----------



## kristylers2008

stoke1863 said:


> Just got a used little dot mk2 with matched Russian 6N6P+6J1P-EV
> 
> Should I be looking to try something else


 
  
 you can check  6N6P-I Novosibirsk and early 6J1P-EV Voskhods (1970-1972),
 sound will be amazing
  
 Regards, Mike


----------



## stoke1863

stoke1863 said:


> Wondering if someone could help.
> 
> Got a used MKII with 6N6P+6J1P-EV tubes.
> 
> ...


 
 I have to backtrack on this, I didnt allow my ears to adjust to the tubes, Just swapped back after many hours to stock and the Russian tubes are much much much better vs stock tubes.


----------



## muscleking

stoke1863 said:


> Wondering if someone could help.
> 
> Got a used MKII with 6N6P+6J1P-EV tubes.
> 
> ...


 
http://www.ebay.ca/itm/6HM5-EC900-EI-Yugoslavia-NOS-matched-pair-Little-Dot-Amp-FREE-SHIPPING-WW-/251691711374?hash=item3a99febb8e:g:~~QAAOSwyjBW6~mr
  
 these makes a difference vs stock tubes. also the older the better. bigger bottle are also better than short ones.
  
 great seller, I ordered 2 and one wasn't working and he sent me 4 more. so now I have 5 of these tubes.


----------



## stoke1863

ok i got an issue, id say every 10-30 mins i get an audible pop (from both channels i think) i switched back to Stock power tubes and they are less frequent but they still happen, its literally one pop and thats it for 30 minutes.
  
 Any ideas what the issue may be?


----------



## spiderking31

I would contact an electronics technician, as your amp may need servicing. To contact David in China, and shipping it to Asia is going to cost an arm and a leg  I would keep the cost and complications to a minimum. Hope I helped you


----------



## EinTheVariance

Just got the MK III today and have been enjoying them   I got them with a pair of voshkods also, but I noticed the 6J1P-EV (gold rocket logo, three grooves) makes the sound bright, it sounds good, but sounds more like an SS amp.  I'm sure these are great with the HD 650, but with the HD 600, it felt a tad too bright at times.  I much preferred the stock M8100, probably just because of my combo.
  
 I wanted to ask if you guys are disconnecting these every night or just leaving it plugged in always?  The manual seems to suggest unplugging it after you are done to minimize the risk of brownouts, surges, etc 
  
 Also, I noticed that my tubes don't get anywhere nearly as bright as some of the other pics I've seen.  Is this just a difference in tubes?  Or perhaps it's the gain or how long it's been on?  For instance, here's a pic I found:



  
 vs what mine looks like:


----------



## superdux

I disconnect from the power after I've finished listening.I guess it depends on your Fotografie skills how much the tubes are illuminated.


----------



## EinTheVariance

superdux said:


> I disconnect from the power after I've finished listening.I guess it depends on your Fotografie skills how much the tubes are illuminated.


 
 haha I do admit that my photography skills are close to nil.  My pic was taken with a smartphone after all, but you'd think it'd look brighter especially under what looks to be a lower light condition in the room.  Hell, my tubes don't look that bright even with my the lights off in the room.
  
 Another thing I'm noticing is that the amp seems to be transferring heat to the headphones itself...is this normal?  After wearing for about 15 min, my right ear especially is warm.  This definitely doesn't happen if I'm powering the HD 600 with the O2.  If I take the headphones off my head and keep the music playing, I can feel the warmness on the right earcup especially if I place the back of my fingers against the cup/foam covering the driver.


----------



## TrollDragon

I just flip the power switch to Off, that disconnects the hot side of the AC line from the amplifier.
  
 That's a new one for me, where the amplifier causes a headphone to warm up...


----------



## EinTheVariance

trolldragon said:


> I just flip the power switch to Off, that disconnects the hot side of the AC line from the amplifier.
> 
> That's a new one for me, where the amplifier causes a headphone to warm up...


 
 that's what I thought people would do usually, but not sure so I wanted to see how many people just turn off vs unplugging every time.
  
 Hmm...I guess it could just be a coincidence.  It's definitely not too warm or anything, kind of like hovering your hands above the tubes a bit.  Actually, the first time I auditioned the setup yesterday, I didn't notice it till I put the headphones down and went out to dinner.  I noticed that my right ear was oddly warm.  Then when I came back after dinner for another session, that's when I noticed the warmness from the right cup...It's not a big deal I guess.


----------



## SomeGuyDude

I will say, the tubes on this thing are STUPID HOT.


----------



## Gezzaman

Hi guys, a quick question,
  
 When trying to use 6AS7G  as powertubes for my LD3, is this external power supply usable?
  
 http://www.ebay.com.au/itm/12V-15A-180W-Switching-Power-Supply-Transformer-For-LED-Strip-Light-New-OK-/251742156213?hash=item3a9d0075b5:g:BMkAAOSwuMFUfsaw
  
 or should it find something else


----------



## ridhuankim

Hi, all. Please don't shoot me if I am asking wrong question at the wrong thread.
Any advice if I wanted to go for solid state tubes?

I currently have MK IV SE.
I use it at the office.
I found from googling there were solid state tubes and some people say they cannot replace real tubes.
But if it is reasonably good and will last a life time and hopefully use less electric, why not?
Has anyone tried solid state tubes?

There is Schiit LISST.
Would this work with MK IV SE?


----------



## WilliamLeonhart

No. Schiit themselves warned it would not work outside. Beside, the Lyr doesn't use the same kind of tubes as LD


----------



## Danosaurus

Hey guys! I am new to tube amps and I am planning on picking up the LD Mk II currently on Massdrop. I am trying to decide between the tube upgrade options. Can anyone give some opinions/recommendations between JAN 5654, RTC 5654 and CV4010?


----------



## XSAMURAI

danosaurus said:


> Hey guys! I am new to tube amps and I am planning on picking up the LD Mk II currently on Massdrop. I am trying to decide between the tube upgrade options. Can anyone give some opinions/recommendations between JAN 5654, RTC 5654 and CV4010?


 
  
 hi
  
 mullard M8100 : Warm mellow sound with good dynamic and very nice low end And perfect choice for bright sounding headphones ( treble sensetive )
  
 VOSHKOD 6ZH1P-EV : Warm tone but more bright than m8100 with nice dynamic and good impact on bass and overall smooth bright sound
  
 GE JAN 5654W : bright and smooth near analytical , less impact on bass compare to m8100 and 6zh1p overall very similar to voshkod 

 I haven't had much time to burn in tubes yet


----------



## shepperd

In addition ( remembering these are my ears and a preamp, not the Little Dot) : Originally I thought the Voshkod was the best sounding, despite taking a hellishly long time to break in. It has been replaced in my personal hyrarchy however by two others. First up is an early set of Tung Sols (62') and close behind Nos Tesla (unobtanium unless you are very lucky).The latter are very smooth and warm and musical but less extended and spacious than the Tung Sol. They are what I imagine good Mullard to be. I have ordered some more Voshkod, earlier and perhaps slightly different. Persistant yes, in spite of knowing I have at least 120 hrs to make a judgement. Oh yes and both the Tung Sol and Tesla come on song within 20 hrs or so. Both are extreemly scarce at the moment 
	

	
	
		
		

		
			





 and prices are going up sadly.


----------



## TrollDragon

Guys, can we at least type the names of the tubes properly?
  
*Voskhod* is the correct spelling of the tubes with the Rocket Logo...


----------



## MIKELAP

trolldragon said:


> Guys, can we at least type the names of the tubes properly?
> 
> *Voskhod* is the correct spelling of the tubes with the Rocket Logo...


----------



## AReasonableMan

Hey tube-gurus. I have an MKI+ with 70's 6JI Voskhods. I think i'm going to upgrade to a MKII, and keep the Voskhods for it. What power tubes pair well with them? I use HD600s, and the goal is a mid-centric and softened highs sound.


----------



## AReasonableMan

Looks like 6N6P-IR for me. Just found the power tube reviews on page 201. Thanks anyway.


----------



## MIKELAP

areasonableman said:


> Looks like 6N6P-IR for me. Just found the power tube reviews on page 201. Thanks anyway.


 
 More interesting stuff


----------



## Johnnysound

Hi Mikelap, great guide to this big thread, no doubt the "ultimate reference" on LD amps tube rolling and mods, specially useful for the new guys discovering the amazing sonic potential of these amps. Of course, most of their questions are already covered somewhere here, but it is not easy to find answers browsing 700 pages of posts !! My personal experience in this thread was a great ride, beginning from zero, step by step, not only obtaining better sound each time, but learning a lot about tubes... I think is the way to go, every listener have his own preferences and will obtain great SQ for his headphones with just a little tube rolling, and this is what separate LD amps from others...they are designed for just that. Maybe we can call this "level 1" mods, the Yugos EF95 are "plug and play" and excellent tubes, but some EF92 and EF94 tubes are really nice and worth experimenting with, (with the socket strapping trick to avoid cumbersome jumper changes), for example Tung Sol 6485 (EF92), I got a NOS pair from 61', and they sound more lively, detailed and precise than the Yugos, a matter of taste and sinergy with your own gear. All this to say that there are no such thing as the "perfect tube" for your LD...

And Level 2 and 3 mods are another matter...(LOL)


----------



## shepperd

Lazy mind=lazy fingers.I stand corrected


----------



## Moustache

I just bought a pair of 6ZH1P-EV, can't believe how good they sound comparatively to the stock ones. Why don't they sell it with them directly?

 (I bought them from this seller http://www.ebay.com/itm/261485347066?ssPageName=STRK:MESELX:IT&_trksid=p3984.m1555.l2649 , since the ones from yenaudio are quite a bit more expensive, I believe they're matched too)


----------



## muscleking

shepperd said:


> In addition ( remembering these are my ears and a preamp, not the Little Dot) : Originally I thought the Voshkod was the best sounding, despite taking a hellishly long time to break in. It has been replaced in my personal hyrarchy however by two others. First up is an early set of Tung Sols (62') and close behind Nos Tesla (unobtanium unless you are very lucky).The latter are very smooth and warm and musical but less extended and spacious than the Tung Sol. They are what I imagine good Mullard to be. I have ordered some more Voshkod, earlier and perhaps slightly different. Persistant yes, in spite of knowing I have at least 120 hrs to make a judgement. Oh yes and both the Tung Sol and Tesla come on song within 20 hrs or so. Both are extreemly scarce at the moment
> 
> 
> 
> ...


 
  
 i have been switching back and forth on the 62 FAA 6ah6 with viskrod and yugo 6hm5, i have 4 matched viskrod with 4 matching 6hm5. somehow i cannot go back to anything after the 62 FAA. thanks to your recommendations. it's the only tube that i like with the beyer t1.2. i also replaced the power tube with 6n6p-IR. not sure it needs breaking in but not much difference vs stock ones. which mine turned out to be made in 1970 6n6p. i think the IR didn't improve but made it worse but i will give it some time only spent 1 hour on it. the 1970 6n6p which comes with the LD MKiii works great with the FAA and after it is on for 8 hours the sound becomes extremely warm and it is quite additive. but i everytime that happens it's bed time i have to turn it off : (
  
 the yugo and viskrod are quite bright. almost sound like bone stock solid state amp. so far i have no desire of trying any other tube other than the 62 FAA 6ah6. you said you found some secret antique tubes did it work out for you?
  
 im just moving to a new home now and once settle down i will listen to music a lot more. but need to buy a computer desk first.


----------



## shepperd

Yes I thought I had hit gold with a pair of NOS Teslas.Sadly not. They are warm and cozy and quite listenable but are lacking in "air"and space, So at present I am breaking in a pair of Voskhod with gold pins and supposedly a different internal composition. Weather or not this is true (a part from the gold pins which do appear genuine), unlike the previous set they sound better in the early stage of burn in so maybe...Unless somebody comes up with a yet to be discovered tube in this family, it appears that the Nos Tung Sol and the early versions of the Voskhod are indeed the best.


----------



## vilhelm44

I've been going through this thread as I have my first tube amp coming, the Little Dot IV SE. I think it's coming with 6H30Pi and M8100 tubes.  What other good combos are there for HD650s? The GE JAN5654W, 6ZH1P-EV & Tung-Sol 6AK5 drivers look like a good bet for a balanced sound with good soundstage.
  
 Can anyone give me some combinations please for power and driver tubes with HD650 for a balanced sound with good balanced sound across the board with good soundstage?
  
 Thanks.


----------



## bharat2580

vilhelm44 said:


> I've been going through this thread as I have my first tube amp coming, the Little Dot IV SE. I think it's coming with 6H30Pi and M8100 tubes.  What other good combos are there for HD650s? The GE JAN5654W, 6ZH1P-EV & Tung-Sol 6AK5 drivers look like a good bet for a balanced sound with good soundstage.
> 
> Can anyone give me some combinations please for power and driver tubes with HD650 for a balanced sound with good balanced sound across the board with good soundstage?
> 
> Thanks.


 

 for me the mallards ef95 and the 6p6-ir works the best with the 650 , the 30pi and the tung sol the voskhod all are a little bright for me , they were good for the mk III but for the se i prefer the above mentioned.


----------



## vilhelm44

bharat2580 said:


> for me the mallards ef95 and the 6p6-ir works the best with the 650 , the 30pi and the tung sol the voskhod all are a little bright for me , they were good for the mk III but for the se i prefer the above mentioned.


 
  
 Thank you for that, that's great. I ended up being a bit trigger happy and buying some 6J1P-EV, RAYTHEON & JAN 6AK6 (although I think I've made a mistake with those as didn't notice they were 6AK6). I'll do a little write up soon.


----------



## gulakpi

For me, the M8100 and 6HM5 work best with my low-Z AKG (K712) cans..
 The Voskhod is a bit too bright, but is OK (still not my preference) with my HD650.
 If you are using the HD6xx, don't hesitate to try a pair of 6SN7 as power tubes (adapters needed) as recommended by the good guys here.  They are amazing for phones with 300 ohms and above and smooth as silk.
  
 Enjoy your new amp!  You will not regret your purchase!


----------



## vilhelm44

gulakpi said:


> For me, the M8100 and 6HM5 work best with my low-Z AKG (K712) cans..
> The Voskhod is a bit too bright, but is OK (still not my preference) with my HD650.
> If you are using the HD6xx, don't hesitate to try a pair of 6SN7 as power tubes (adapters needed) as recommended by the good guys here.  They are amazing for phones with 300 ohms and above and smooth as silk.
> 
> Enjoy your new amp!  You will not regret your purchase!


 
  
 Thank you, I should be getting it today...can't wait to give it a spine . What kind of adaptor do I need for the 6SN7?  I've seen this adaptor:
  
 http://www.ebay.com/itm/2piece-Gold-plated-C3G-TO-6AK5-tube-converter-adapter-/191424601510?rmvSB=true
  
 Is this the correct one?


----------



## shepperd

Don't do what I did, which is to judge tubes too quickly. Some, if not all, can require a lot of run-in. The best example I have is the Tesla's, which I judged to be nice but a bit soft at both ends and not very transparent. This was in spite of about 30 hours of use. I put them in again and around 50 hours they changed radically, much like the Voshkod (at 100+). So much so that I am reconsidering placing them above the Tung Sol. This is all very confusing and a bit tiresome but that's the nature of tube-rolling apparently.


----------



## MIKELAP

vilhelm44 said:


> gulakpi said:
> 
> 
> > For me, the M8100 and 6HM5 work best with my low-Z AKG (K712) cans..
> ...


 
 NO this adapter is for C3G tubes which by the way is probably the best tube youll ever use in a mk3-mk4  .This is the last setup i used in my MK3 6SN7 and  C3G'S as drivers with the adapters you just referred to .This is the adapter i used for 6SN7 tubes as power tubes 6SN7(TOP) TO 6CG7 ( IN AMP ) This is the better quality adapter http://www.ebay.com/itm/1pc-Gold-plated-6SN7-6n8p-CV181-TO-6CG7-6FQ7-tube-converter-adapter-/201115946751?hash=item2ed371ceff:g:J2oAAOSwQjNW-kSg


----------



## MIKELAP

mikelap said:


> vilhelm44 said:
> 
> 
> > gulakpi said:
> ...


 
 This is a C3G tube its a 8 pin Loctal the adapter shown in your link is the better quality one as those tube are fragile DO NOT WIGGLE THEM WHILE INSERTING OR REMOVING  the glass might break it happen to me. Search for C3G infos in this thread by the way only the C3G is used in this amp NOT THE C3M OR OTHERS .To remove tube from adapter  take a small flat screwdriver and pry it out evenly allaround .


----------



## vilhelm44

shepperd said:


> Don't do what I did, which is to judge tubes too quickly. Some, if not all, can require a lot of run-in. The best example I have is the Tesla's, which I judged to be nice but a bit soft at both ends and not very transparent. This was in spite of about 30 hours of use. I put them in again and around 50 hours they changed radically, much like the Voshkod (at 100+). So much so that I am reconsidering placing them above the Tung Sol. This is all very confusing and a bit tiresome but that's the nature of tube-rolling apparently.


 
  
 I think I've lucked out already as I have the unit I have has come with 6H30Pi and M8100 tubes, it's second hand so has some hours on it. The sound is already wonderful, I think I'll have a hard time beating this but I'll have fun trying . I've read in this thread and others that burn in is needed...and a lot of patience. 
  


mikelap said:


> NO this adapter is for C3G tubes which by the way is probably the best tube youll ever use in a mk3-mk4  .This is the last setup i used in my MK3 6SN7 and  C3G'S as drivers with the adapters you just referred to .This is the adapter i used for 6SN7 tubes as power tubes 6SN7(TOP) TO 6CG7 ( IN AMP ) This is the better quality adapter http://www.ebay.com/itm/1pc-Gold-plated-6SN7-6n8p-CV181-TO-6CG7-6FQ7-tube-converter-adapter-/201115946751?hash=item2ed371ceff:g:J2oAAOSwQjNW-kSg


 
  
 Thanks for your message. I'll look into those C3G tubes at some point, I think I'll enjoy what I have for the time being as it's really good already.  I don't know why it's taken me this long to get a tube amp!
  


mikelap said:


> This is a C3G tube its a 8 pin Loctal the adapter shown in your link is the better quality one as those tube are fragile DO NOT WIGGLE THEM WHILE INSERTING OR REMOVING  the glass might break it happen to me. Search for C3G infos in this thread by the way only the C3G is used in this amp NOT THE C3M OR OTHERS .To remove tube from adapter  take a small flat screwdriver and pry it out evenly allaround .


 
  
 Thanks again for the info, it's been a great help.  Those tubes look heavy duty...I'll do some research on them.


----------



## ArcanoCuori

Hello everyone,
  
I've currently got a Little Dot MK IV SE with the stock power tubes (6H30PI I believe?) I've never changed them out since I've gotten it. I used to use Mullard M8161 when I first had it, but I switched to the VOSKHOD 6ZH1P-EV, which I prefer when using my HD650's. 
  
Anyway, I got all this a while ago and I've been trying to search through this forum post; but it's a little convoluted and I was just wondering what everyone is recommending as for driver/power tubes nowadays for the IV and 650? I've heard some talk of 6SN7 and 6HM5 Yugoslavia's but I can't seem to find much information about them in regards to what they sound like.
  
 Thanks!


----------



## MIKELAP

arcanocuori said:


> Hello everyone,
> 
> I've currently got a Little Dot MK IV SE with the stock power tubes (6H30PI I believe?) I've never changed them out since I've gotten it. I used to use Mullard M8161 when I first had it, but I switched to the VOSKHOD 6ZH1P-EV, which I prefer when using my HD650's.
> 
> ...


 
 If i remember the 650's are warm sounding so maybe the 6SN7 isnt the route to go for you but maybe the C3G tubes as drivers would do the trick less warm more detailed sound. Here are a few post about happy user of C3G with HD 650 just use search function atop the page, just write C3G  .


----------



## shepperd

Damnation! Just as I was getting to like them, one of my Tesla's just died (it lights up but no sound) and the other flashes badly from a cold start. Since I cant find any more I'm giving up on that. Back to the Tungsol 6AH6 and the Voshkod gold pins. I haven't tried the JAN since I thought I didn't like them but now I will try them again.


----------



## lglions

arcanocuori said:


> Hello everyone,
> 
> I've currently got a Little Dot MK IV SE with the stock power tubes (6H30PI I believe?) I've never changed them out since I've gotten it. I used to use Mullard M8161 when I first had it, but I switched to the VOSKHOD 6ZH1P-EV, which I prefer when using my HD650's.
> 
> ...


 
 For power tubes - 6N6P-IR or 6SN7. First one doesn't require adapters, the second needs them. One warning - 6SN7 most likely won't work with low impedance HPs. Should be very good of your 650s though.
  
 For drivers - C3G. I acquired several kinds and I like Telefunken over Siemens. Warning here - adapters didn't go into my MK-III because of the rings. So I had to get spacers (test 7 pin sockets).
  
 My current setup is  6N6P-IR/ C3G. I use spacers for both power and driver tubes, as it cools down the whole setup significantly not letting tubes warm up the amp.


----------



## bangdomarkin

Hello guys, i want to start my journey with tubes and need some advice. For the Little Dot MKII i need a pair of tubes of my preference right? And you're can give me recommendations of websites for buy Tung-Sol 6AK5 and *Mullard M8161/CV401*?


----------



## Hitogoroshichan

Hey guys, I bought a Little Dot MKII a short while ago and have been hanging around here reading whatever I can find on the different tubes I can use in it and having loads of fun trying out different combinations. I'm currently using Yugo 6HM5s for drivers, which I love, and I've got a 6SL7 in the mail that I'm looking forward to trying out. For power tubes I've currently got two Soviet 6H8Cs and have been looking into getting the stuff needed to use 6SA7s. While I was looking around eBay I started wondering whether it was possible to use any of the dual tube to 6SN7 adapters like:
  
 http://www.ebay.co.uk/itm/1pcs-Tube-Amplifier-6J5-6J5-Replace-6SN7-Tube-Socket-Adapter-Suzier-B9-/172330795623?hash=item281fb74267:gPAAAOSwd0BV5EAG
 or
 http://www.ebay.co.uk/itm/1pcs-Tube-Amplifier-2C22-2C22-Replace-6SN7-Tube-Socket-Adapter-Suzier-C7-/172330795063?hash=item281fb74037:g:vrMAAOSwyQtV5rmU
  
 Has anyone tried these out or can tell whether they'd work or not?


----------



## janetello

bangdomarkin said:


> Hello guys, i want to start my journey with tubes and need some advice. For the Little Dot MKII i need a pair of tubes of my preference right? And you're can give me recommendations of websites for buy Tung-Sol 6AK5 and *Mullard M8161/CV401*?


 

 Hi, I've read a couple of months ago a review here in the beginning of the thread and saw that Voskhod 6ZH1P-EV have higher scores than Mullard and Tungsol. So I've bought a matched pair of 77s here and I'm completely satisfied with their service. Vintage Voskhod is great, really recommend it.


----------



## vilhelm44

I've now bought adapters for the C3G and 6SN7 tubes for my Little Dot IV SE. Are there any differences between the Siemens and Lorenze C3G tubes?  Also, what's the general feeling on the best 6SN7 tubes to use with the IV SE and HD650s?  Thanks.


----------



## vilhelm44

Which are the best C3Gs to pick up between  Siemens, Lorenze and Telefunken?


----------



## gibosi

If the C3g black cans are shiny with silk-screened logos and text, then they were manufactured by Siemens in the 1970's, regardless of the printed brand. If you want a C3g that was actually manufactured by Lorenz or Telefunken, you will have to obtain tubes manufactured in the 1950's and 60's.
  
 These earlier tubes tend to have flat-black cans with embossed logos and text. Unfortunately, I have yet to find an early embossed Telefunken. To my ears, the sound of the Lorenz to be a bit more laid-back while the Siemens is more forward. And the best way I can describe the difference between the older and newer Siemens, is the newer Siemens seems to have a bit more reverb in the mids.
  
 Lorenz, 1966
  

  
 Siemens, shiny black, silkscreened, 1970's. Flat-black, embossed, 1960's


----------



## vilhelm44

Thanks Gibosi, that's great info.  I've put a bid in for a pair of embossed 60s Seimens C3Gs.  Are there any recommendations for 6SN7 power tubes to pair with the C3Gs please?


----------



## gibosi

As I have a hybrid LD 1+, I have no experience with using 6SN7 as output tubes. But perhaps others will chime in here...


----------



## vilhelm44

gibosi said:


> As I have a hybrid LD 1+, I have no experience with using 6SN7 as output tubes. But perhaps others will chime in here...


 
  
 No problem, thanks again for your help with the C3Gs, much appreciated.


----------



## lglions

vilhelm44 said:


> No problem, thanks again for your help with the C3Gs, much appreciated.


 
 Great tubes. I use Telefunken. I have embossed Siemens as well, will roll them in tomorrow an re-compare.
  
 After I found great combination for my taste active rolling stopped.
  
 I am afraid to buy expensive amp now - afraid that it won't exceed what I have now.


----------



## vilhelm44

lglions said:


> Great tubes. I use Telefunken. I have embossed Siemens as well, will roll them in tomorrow an re-compare.
> 
> After I found great combination for my taste active rolling stopped.
> 
> I am afraid to buy expensive amp now - afraid that it won't exceed what I have now.


 
  
 Cool. I'll look forward to hearing about that. Which power tubes do you use with the C3G?


----------



## lglions

vilhelm44 said:


> Cool. I'll look forward to hearing about that. Which power tubes do you use with the C3G?


 
 6N6P-IR.
  
 6SN7 as power tubes didn't work for HPs I use the most.


----------



## vilhelm44

I have the IR tubes as well. I'm enjoying the EH PI Gold pins at the moment. I've been reading about different tubes and fancied experimenting with the LD IV SE. So got some adapters and C3Gs. Really looking forward to giving them a whirl with my HD650s. Also got a Schiit Modi Multibit coming today so will be interesting to how that sounds.


----------



## gibosi

lglions said:


> Great tubes. I use Telefunken. I have embossed Siemens as well, will roll them in tomorrow an re-compare.


 
  
 Are your Telefunkens embossed? I would like to see a picture, please.


----------



## lglions

gibosi said:


> Are your Telefunkens embossed? I would like to see a picture, please.


 
 No no ... My Telefunken C3gs are not embossed, my Siemens are.
  
 Pictures below - 2 kinds of Telefunken and embossed Siemens.


----------



## gibosi

I have a pair of Telefunkens that look like yours. The date code "qf" suggests March, 1965. However, with my ears and gear, I cannot reliably distinguish between these Telefunkens and the embossed Siemens. In my experience thus far, tubes manufactured in different factories by different companies always sound different. And therefore, until I can get my hands on a pair of embossed Telefunkens, I can't be sure if mine were manufactured by Telefunken or Siemens. I have seen embossed Telefunken C3m, so I am quite sure embossed C3g exist, but again, I have yet to find any.....
  
 Edit: Oh, and the pair of Telefunken installed in your amp appear to be shiny black. So I am quite sure these were manufactured by Siemens in the 1970's.


----------



## Johnnysound

I have a quartet of Siemens C3Gs, two bought NOS around 2 years ago and used about 200 hours, two used, and these are terrific driver tubes. I do not know about Telefunken or another brand C3Gs, but I suspect there is little difference between them. All were made in the sixties, or early seventies, under a strict West German, mil spec requirement typical of cold war for undeground telephone signal amplifiers that not only will survive a nuclear EMF pulse, but will amplify and forward even the tiniest communication signal, with utmost fidelity, and last a lifetime...cost no object, this class of tubes were designed to perform, with the very best and very expensive exotic metals, a Thorium alloy (I think) to absorb oxygen atoms inside the tube to preserve absolute vacuum...an all out assault to design a super reliable hybrid pentode/triode audio amplification tube. The specs of the C3G are unmatched, transconductance is enormous, something to expect in a tube designed to amplify weak signals reliably...this in itself does not relate necesarily to sound quality, but it does in the C3Gs. And power, dynamics, bandwidth, they will reveal ruthlessly the limitations of your power tubes. For example, 6SN7G double triodes were a clear step ahead over the stock tubes in my LD MKIII, and the C3Gs make them sing clear and loud, the differences just jump out, only a few were up to the task. I went all out to mod my little preamp to accept the mighty 6AS7G big bottles, and after that even the best 6SN7Gs sounded small, limited, restricted. The C3Gs clearly had the power and the amperes to control the big ones solidly, superior dynamics, fast, tight bass and a soundstage to die for... and the little thing is working as a preamp driving 2 mono SS NAD Amps. Extremely powerful as a Pre, I learned to set the NADs at about 1/4 output... Cheers to all !


----------



## gibosi

johnnysound said:


> I have a quartet of Siemens C3Gs, two bought NOS around 2 years ago and used about 200 hours, two used, and these are terrific driver tubes. I do not know about Telefunken or another brand C3Gs, but I suspect there is little difference between them. All were made in the sixties, or early seventies, under a strict West German, mil spec requirement typical of cold war for undeground telephone signal amplifiers that not only will survive a nuclear EMF pulse, but will amplify and forward even the tiniest communication signal, with utmost fidelity, and last a lifetime...cost no object, this class of tubes were designed to perform, with the very best and very expensive exotic metals, a Thorium alloy (I think) to absorb oxygen atoms inside the tube to preserve absolute vacuum...an all out assault to design a super reliable hybrid pentode/triode audio amplification tube. The specs of the C3G are unmatched, transconductance is enormous, something to expect in a tube designed to amplify weak signals reliably...this in itself does not relate necesarily to sound quality, but it does in the C3Gs. And power, dynamics, bandwidth, they will reveal ruthlessly the limitations of your power tubes. For example, 6SN7G double triodes were a clear step ahead over the stock tubes in my LD MKIII, and the C3Gs make them sing clear and loud, the differences just jump out, only a few were up to the task. I went all out to mod my little preamp to accept the mighty 6AS7G big bottles, and after that even the best 6SN7Gs sounded small, limited, restricted. The C3Gs clearly had the power and the amperes to control the big ones solidly, superior dynamics, fast, tight bass and a soundstage to die for... and the little thing is working as a preamp driving 2 mono SS NAD Amps. Extremely powerful as a Pre, I learned to set the NADs at about 1/4 output... Cheers to all !


 
  
 I will grant you that in the LD, the C3g is about as good as it can get. But with all due respect.....
  
 First it is important to remember that the LD was designed around the 6AK5, strapped to operate as a triode. If you put a 6SN7 into a circuit designed for a 6AK5, it simply cannot sound its best. The bias is too far from optimal. Fortunately for LD owners, a C3g, strapped to operate as a triode, is a much better fit, and yes, it does sound very good. However, in an amp designed to run 6SN7, I can assure you that the best 6SN7's do not sound "small, limited, restricted." I find them to be just as good as the C3g, but different.
  
 Second, there is this myth that the C3g has been engineered to such high specifications that it is virtually transparent and doesn't have it's own sound. In my experience, this is not true. Tubes manufactured in different factories sound different. And further, tubes manufactured in the same factory, but at different times, sound different. I have Lorenz and Siemens C3g, and I assure you that they really do sound significantly different.
  
 And third, yes, operated as a pentode, the engineering specifications of the C3g are among the very best of any vacuum tube ever manufactured. However, when it is operated as a strapped triode, the specifications are about the same as a 6SN7. This alone is a major engineering feat. Most pentodes, strapped as triodes, have relatively high levels of distortion and are not very linear, for example, the 6AK5. So again, while this is a major accomplishment, in the end, you have a "C3g triode" that compares well to a 6SN7. But in terms of specifications, if compared to an ultra-linear, low distortion double triode, such as an E80CC, a strapped C3g is really nothing to brag about.
  
 I should point out that my amp is designed from the ground up to run either a pair of C3g or a single 6SN7, so it is very easy for me to compare them with everything else being equal.
  
 So again, in an LD, the strapped C3g is perhaps among the very best, if not the best. But given that, it is simply not possible to extrapolate beyond the LD and come to any meaningful conclusions.
  
 Cheers


----------



## Johnnysound

Oh yes, G, let me say first that I am not talking about 6SN7Gs as driver tubes, only as power tubes in the MKIII, providing superior sound against the stock power tubes, with the C3Gs in front. In fact, after rolling many 6SN7Gs in this unconventional role, including super nice Sylvanias chrome tops, vintage CBS Hytrons, RCAs and my favorite Tung-Sols, from different vintages, I was hooked with the ITT branded, Hitachi Japan made tubes, of which I bought a quartet. After a good warm up, these 6SN7Gs are magical, in terms of dimension and space. Not a warm or euphonic tube, they can sound very solid state like, dynamic but dry, but after an hour operating, exceptional air and sound comes through. All the opposite from "small, thin and restricted" and I have to agree that these great tubes could not be described that way. They are not, and my comment is valid only in comparative terms with 6AS7Gs as power tubes. I was so happy with my setup, it sounded so good that I doubted that the effort to go all out for the big tubes would offer something better. And my dear G, you, among other experts, concur that the upgrade was worthwile. And it was, of course. So, you get a grand sound, more open, unrestricted, dynamic, dimensional. In contrast, the 6SN7Gs, any of them, even the very best sounded ,well, smaller, if you know what I mean. As power tubes, of course...


----------



## gibosi

Oh, I didn't catch the fact that you were using 6SN7 as output tubes. For sure, while they are superb, small-signal tubes, a pair of 6SN7 simply cannot provide enough current to be effective output tubes. But perhaps 4 or 5, in parallel, per side, might do the trick. lol 
  
 And I commend you for going the extra mile to mod your LD to handle 6AS7s. The 6AS7 pushes something like 100ma, compared to about 20ma for the stock output tube, or a 6SN7. Being able to push this much current as well as a relatively low plate resistance to gain ratio, makes the 6AS7 a very effective output tube when used in an OTL. And beefing up the associated circuitry in your LD to handle the extra current was very wise and prudent.
  
 Cheers


----------



## rosgr63

Hi Ken,
 The SinglePower PPX3-6SN7 uses one 6SN7 as a driver and two 6SN7s for output.
 Not a bad amp at all.
 I'm side tracking from the LD just for info.


----------



## gibosi

I can only conclude that there must be some very ingenious circuitry in the SinglePower. For sure, two 6SN7s are quite inadequate in more conventional OTLs like the LD and Glenn's OTL.
  
 It appears that these amps are not being made anymore... too bad....


----------



## rosgr63

I suppose I'm lucky I got one LOL


----------



## vilhelm44

When you guys mention spacers, where do you buy them from?  My C3Gs arrived today but they don't quite fit with the adaptors I have in the LD IV SE even without the grill, which is a pain.


----------



## vilhelm44

I just found the Leeds Radio site for the spacers but they don't ship to the UK.


----------



## vilhelm44

It's all good now, Richard from Leeds Radio was kind enough to ship to the UK


----------



## dbaker1981

Are 12AX7 tube compatable with the mk 1+ and mkiii?


----------



## gibosi

dbaker1981 said:


> Are 12AX7 tube compatable with the mk 1+ and mkiii?


 
  
 Not really. But where there is a will there is a way. For example, an external 9-pin breadboard socket plus a couple of 7-pin test sockets will do the trick.


----------



## dbaker1981

gibosi said:


> Not really. But where there is a will there is a way. For example, an external 9-pin breadboard socket plus a couple of 7-pin test sockets will do the trick.




Im looking for that gold lion sound and it seems that they dont make any in the ef95. Any suggestions on similar sq tubes that fit?


----------



## gibosi

dbaker1981 said:


> Im looking for that gold lion sound and it seems that they dont make any in the ef95. Any suggestions on similar sq tubes that fit?


 
  
 I've never heard a gold lion, so I have no idea...  Sorry....


----------



## Hitogoroshichan

Just wondering, do 6AS7/6080s have the same problem as 6SN7s have with HE-500s?


----------



## gibosi

hitogoroshichan said:


> Just wondering, do 6AS7/6080s have the same problem as 6SN7s have with HE-500s?


 
  
 No. The 6AS7/6080 is a much more powerful tube, and it can drive the HE500 better than a 6SN7 or a 6N6PI. However, the LD was not designed to use such a powerful tube and this presents a couple problems. First, the 6AS7 heater draws 2.5 amps, whereas the 6N6PI draws about 1.0 amps, and therefore, it is absolutely necessary to use an external heater power supply.
  
 The second problem, alluded to above, is the fact that the plate current of a 6AS7 is about 100 mA, whereas, it is around 30 mA for a 6N6PI. And again, the associated circuitry was not designed to handle 100 mA. As a result, resisters and capacitors in the signal path may well burn out. And therefore, I would encourage anyone wanting to run 6AS7 to follow Johnnysound's example and upgrade their LD to handle this tube.
  
 That said, some in this forum have been running the 6AS7 without any circuit modifications, only an external heater power supply, and have not had any problems. Even so, there is still considerable risk that the circuit will eventually fail due to the excessive current. Thus, I cannot recommend the use of the 6AS7 without circuit modifications.


----------



## SomeGuyDude

Quick thanks to this thread! Bought a pair of Mullard M8100s to go with my HD700s. I'm thinking they should warm 'em up just right.


----------



## Jallen

Hey there guys, not sure if this thread is very active but I'd like to get an opinion on my pick for my LD mkII.
 I've found that the amp is solid out of the box, but people have told me it really excels with some new valves.
  
 I was thinking of going for a kit of:
  
  2 x M8100/CV4010/EF95 Mullard
 2 x 6H6PI/6H6N Novosibirsk “NEVZ-Soyuz"
  
 I have heard praises of the m8100, but has anyone uses the Novos? thanks in advance.


----------



## HungryPanda

That set is a great upgrade to the stock tubes


----------



## Jallen

hungrypanda said:


> That set is a great upgrade to the stock tubes


 
 Brilliant, good to know. Thanks for helping.


----------



## ScottieB

Apologies if this is a bad place for this question but I thought people here would know... My Little Dot MKIII has finally died. I'm not really looking to fix it (again) but since I have all these tubes (EF95 5654 6AK5, EF92, EF91 etc) I bought, are there any other amps I could get that can use them? I know the other little dots (I'm thinking of just getting an MKIV) but was wondering if anything else out there can use these same tubes? I did some searching but didn't find anything but little dot. Thanks.


----------



## SomeGuyDude

scottieb said:


> Apologies if this is a bad place for this question but I thought people here would know... My Little Dot MKIII has finally died. I'm not really looking to fix it (again) but since I have all these tubes (EF95 5654 6AK5, EF92, EF91 etc) I bought, are there any other amps I could get that can use them? I know the other little dots (I'm thinking of just getting an MKIV) but was wondering if anything else out there can use these same tubes? I did some searching but didn't find anything but little dot. Thanks.


 
 Seems like only the Little Dots and something called the Pan Am, from what I've seen.


----------



## WilliamLeonhart

Get the mk4 se. You won't regret it one bit


----------



## MIKELAP

scottieb said:


> Apologies if this is a bad place for this question but I thought people here would know... My Little Dot MKIII has finally died. I'm not really looking to fix it (again) but since I have all these tubes (EF95 5654 6AK5, EF92, EF91 etc) I bought, are there any other amps I could get that can use them? I know the other little dots (I'm thinking of just getting an MKIV) but was wondering if anything else out there can use these same tubes? I did some searching but didn't find anything but little dot. Thanks.


 
 I could use these adapters with 6AK5/EF95 types on top to 6922 in my WA2, but how would it sound i dont know
                                                                                                                                                                                    http://www.ebay.com/itm/1pc-Dual-6AK5-5654-EF95-TO-ECC88-6922-6DJ8-tube-converter-adapter-For-little-dot-/191900199784?hash=item2cae24ab68:g:z-AAAOSwmtJXZVRB


----------



## gibosi

mikelap said:


> I could use these adapters with 6AK5/EF95 types on top to 6922 in my WA2, but how would it sound i dont know
> http://www.ebay.com/itm/1pc-Dual-6AK5-5654-EF95-TO-ECC88-6922-6DJ8-tube-converter-adapter-For-little-dot-/191900199784?hash=item2cae24ab68:g:z-AAAOSwmtJXZVRB


 
  
 My guess is they wouldn't sound all that good in your WA2, which was designed to use 6922 double triodes. The correct bias for the 6922 is very different than that for the 5654. And further, the 5654, being a pentode, was not designed for use as a strapped triode. So it might be fun to try, but I wouldn't get my hopes up. lol


----------



## MIKELAP

gibosi said:


> mikelap said:
> 
> 
> > I could use these adapters with 6AK5/EF95 types on top to 6922 in my WA2, but how would it sound i dont know
> ...


 
 At the price they are selling the adapters wasnt going to try it anyway still have my LDMK3 to use still works fine


----------



## ScottieB

OK thanks for the info...
  
 So then, if I already have lots of tubes, is the SE version worth the extra over the regular MKIV? And are there other options I'm missing in the little dot lineup? (2, 3 and 4/se?)


----------



## MIKELAP

scottieb said:


> OK thanks for the info...
> 
> So then, if I already have lots of tubes, is the SE version worth the extra over the regular MKIV? And are there other options I'm missing in the little dot lineup? (2, 3 and 4/se?)


 
 After talking about the Littledot amp decided to plug it in (MK3) and fired it up used the 6N6P-IR as power tubes  and 6HM5 tall bottles as drivers  and to be honest i was pleasantly surprised i liked what i heard. Personnally from what i remember i would of went for the MK4 myself  not enough to warrant the extra cost for the SE which is i think better tubes for the most part and i think the MK4 is more neutral sounding then the MK3 .If you search the thread you will find your answers especially from TrollDragon he has a MK4


----------



## Hansolo76

scottieb said:


> Apologies if this is a bad place for this question but I thought people here would know... My Little Dot MKIII has finally died. I'm not really looking to fix it (again) but since I have all these tubes (EF95 5654 6AK5, EF92, EF91 etc) I bought, are there any other amps I could get that can use them? I know the other little dots (I'm thinking of just getting an MKIV) but was wondering if anything else out there can use these same tubes? I did some searching but didn't find anything but little dot. Thanks.


 
  
 From what I have seen, I'm pretty sure the Schiit Valhalla 2 uses the same tubes, but don't quote me.
  
 http://schiit.com/products/valhalla-2


----------



## ScottieB

Thanks for that but from what I can see they use similar, but different tubes in the Valhala 2 (6N1P dual triode input, 6N6P dual triode output, 1 each per channel. 6N1Ps rollable to 6DJ8, E88CC, 6922, 6BZ7, and similar types.)


----------



## Hansolo76

scottieb said:


> Thanks for that but from what I can see they use similar, but different tubes in the Valhala 2 (6N1P dual triode input, 6N6P dual triode output, 1 each per channel. 6N1Ps rollable to 6DJ8, E88CC, 6922, 6BZ7, and similar types.)


 
  
 Ahhhh, I see my error.
  
 I was running 6J1P and 6N6P in my MK III.  Thanks for the clarification.  I was actually considering getting the Valhalla 2 to be able to use my current tube inventory :/


----------



## codyg326

. 



What power tubes are in the back?


----------



## GotNoRice

codyg326 said:


> .
> 
> 
> 
> What power tubes are in the back?


 
 Those are Chinese 4P1S-J tubes.  Russian 4P1L tubes work also.


----------



## DjBobby

Changed all 4 tubes on my LD MKII at once. Mullard M8100/CV4010 and Russian 6N6P. Now the right channel pops and crackles. Left it for a long burn in, but have a feeling that it got worse. Which tubes are more probable to make audible trouble, driver or power tubes, or it could be any of them?


----------



## Hitogoroshichan

djbobby said:


> Changed all 4 tubes on my LD MKII at once. Mullard M8100/CV4010 and Russian 6N6P. Now the right channel pops and crackles. Left it for a long burn in, but have a feeling that it got worse. Which tubes are more probable to make audible trouble, driver or power tubes, or it could be any of them?


 
 I don't know which is more likely, but it's easy enough to find the problem tube, just swap the driver tubes out for the stock ones, if the crackle goes you know it's one of the driver tubes and if it's still there then it's one of the power tubes, if it's only crackling in the right channel then the left tubes should be fine.


----------



## dharkharma

Just wanna say thanks to OP for the starter guide, really helped me narrow down my choices for me to play around and explore different tubes.


----------



## MIKELAP

dharkharma said:


> Just wanna say thanks to OP for the starter guide, really helped me narrow down my choices for me to play around and explore different tubes.


 
 check out page 77 other cheaper alternatives for the most part


----------



## ScottieB

Wanted to say thanks again for the info. Just as I was about to get a new MKIV (settling for the non-SE version), a used SE for a nice price popped up on ebay and I jumped on it! I'm excited to get in to rolling some tubes again after months of solid state exclusivity. Also grabbed some Sylvania Golds because I remember the last time I was tube shopping they were like $75/pair or something absurd but I'd always wanted to try them. 
  
 By the way does anyone know where to edit the signature at the end of my posts? I remember typing that years ago but it's way out of date and I can't seem to find where to edit it (I checked my site settings and profile info)... thanks


----------



## TrollDragon

scottieb said:


> Wanted to say thanks again for the info. Just as I was about to get a new MKIV (settling for the non-SE version), a used SE for a nice price popped up on ebay and I jumped on it! I'm excited to get in to rolling some tubes again after months of solid state exclusivity. Also grabbed some Sylvania Golds because I remember the last time I was tube shopping they were like $75/pair or something absurd but I'd always wanted to try them.
> 
> By the way does anyone know where to edit the signature at the end of my posts? I remember typing that years ago but it's way out of date and I can't seem to find where to edit it (I checked my site settings and profile info)... thanks


 
 Got to your profile page.
 http://www.head-fi.org/u/48304/scottieb

 It's near the bottom just before your lists.


----------



## ScottieB

Thanks!


----------



## shepperd

I bought a set of Tesla 6f32 a while back and one died. It lights up but no sound. The other flares at start up but sounds fine. Anyone got a stash of these? I would be happy to buy. Also I have a pair of Voshkod with the gold pins. They have about 70 hours on them.Honestly I cant tell the difference with the non gold pin version. I would be happy to do a trade fro something interesting. Also I got a pair of Tung Sol 6AJ5. They sounded ok but are horribly microphonic. I dont know if I got a bad set or they are somehow incompatible. Anyone have a clue?


----------



## mordy

Hi DjBobby,
  
 You write that you changed all four tubes at once. Many times the crackling and noise could come from a bad contact from corroded pins. Take a small knife (doesn't have to be sharp) or something similar, and gently scrape each individual pin so that that it looks more shiny. Oftentimes you can see the oxidation and dirt on the pins.
  
 If the tube shows a white coating inside it is finished - lost vacuum.
  
 IMHO don't bother with expensive de-oxidation sprays - the mechanical scraping works best.
  
 Good luck!


----------



## DjBobby

mordy said:


> Hi DjBobby,
> 
> You write that you changed all four tubes at once. Many times the crackling and noise could come from a bad contact from corroded pins. Take a small knife (doesn't have to be sharp) or something similar, and gently scrape each individual pin so that that it looks more shiny. Oftentimes you can see the oxidation and dirt on the pins.
> 
> ...


 

 Thanks a lot mordy, will try that.
 No white coating inside, so I guess tubes are still OK. Old Russian 6N6Ps look like they would need some scrapping. I was listening yesterday, or better said tried to listen, but crackling drove me mad.


----------



## shepperd

Having gotten the bug, I now have too many tubes I dont use. Of course I spent too much on them, being greedy and impatient, but I am more than happy to let them go for less than half price. Let's see: a nice set (=2) of Voshkod with the gold pins that have about 80 hours of burn in time. A pair of *GE JAN5654W* with about 50hours.  Tung sol 6AH6 and one tung sol 6AJ5 ( can't find it's mate) and one Tesla 6F32.It's mate died. So I am in France and I will send these nicely packed within europe only. The bunch for 30 euros. If I find the missing ones Ill put them in.


----------



## shepperd

Correction! I know what happened to the missing ones. Strike that off the list but Ill add the original chinese CJ1 just so you remember why we seek out those good old ones


----------



## Hitogoroshichan

I finally got my hands on a couple on C3Gs and I'm really loving them, but It got me wondering if anyone knows if there's any other loctal pentodes or triodes you can use for drivers?


----------



## OctavianH

Anyone knows a tube-shop in EU where I can find something for MK2? All my links are from US, I prefer an EU reliable shop. Thanks!


----------



## DjBobby

octavianh said:


> Anyone knows a tube-shop in EU where I can find something for MK2? All my links are from US, I prefer an EU reliable shop. Thanks!


 

 Buying all my tubes through e-bay from UK. Never had an issue with this shop, highly recommended: http://stores.ebay.com/langrex/


----------



## OctavianH

Additional question related to MK2, it is not very clear for me how to pair Power and Driver tubes. Pairing (2 of the same model in both Driver and Power for each channel) is clear to me. But as far as I see, MK II can only accept 6N6/6H6P in the power area.
 I currently have the stock 6J1 / 6N6 and I was thinking to upgrade them for something with more "precision" like it seems to be Mullard M8100 / CV4010 but it was not clear to me what Power tubes to add, or if to keep stock ones. Please advise.
  
*Any other opinion is welcomed, because I am quite a newbie in the tube area.*
  
 What I listen, quite intense music like rock/metal and usually "fast"stuff where I need presicion, good mids/highs and why not, some bass. But in the bass area I do not expect a lot, this was the reason to retire HD650 because they sounded too bassy for me.
  
 Curenly I listen to Beyerdynamic on the MK2, and seems a quite good pair.
 Directly on the DAC (audio-gd NFB11) I use a pair of HD600 which sound good also, but the sound of the MKII + Beyer is somehow better.
  
 Thank is in advance.


----------



## DjBobby

octavianh said:


> Additional question related to MK2, it is not very clear for me how to pair Power and Driver tubes. Pairing (2 of the same model in both Driver and Power for each channel) is clear to me. But as far as I see, MK II can only accept 6N6/6H6P in the power area.
> I currently have the stock 6J1 / 6N6 and I was thinking to upgrade them for something with more "precision" like it seems to be Mullard M8100 / CV4010 but it was not clear to me what Power tubes to add, or if to keep stock ones. Please advise.
> 
> *Any other opinion is welcomed, because I am quite a newbie in the tube area.*
> ...


 

 As far as I understand, driver tubes have much more influence on the sound sig. That's why is the driver tubes section is so long, where for the power tubes you will find nothing of importance.


----------



## MIKELAP

octavianh said:


> Anyone knows a tube-shop in EU where I can find something for MK2? All my links are from US, I prefer an EU reliable shop. Thanks!


 
 This is Langrex U.K. site usually tube prices are cheaper than Ebay   http://www.langrex.co.uk/


----------



## LugBug1

http://stores.ebay.co.uk/COLOMOR-VALVES-TUBES-COMPONENTS?_trksid=p2047675.l2563
  
 These have huge stocklist and are very reliable. Tubes come professionally boxed and within 24 hrs. (for uk)


----------



## Scutey

Finally got to try my Siemens C3GSs on my LD MKIII today after waiting for the adapters to come from China, well worth the wait, I can see why these tubes are well regarded, the bass in particular is fab, powerful, and detailed, just what I love.


----------



## Scutey

Something I forgot to mention was how scarce and expensive the C3Gs are but I did notice that the C3M is a (bit) more plentiful and a (bit) cheaper, but they never seem to be mentioned as a an option for LDs is this because of heater current, or some other reason?.


----------



## gibosi

The C3m has a 20V heater compared to 6.3V for the C3g. And further, the pin-out is different. However, those with the LD1+, which can run 20V 408A, should be able to run a pair of C3m providing they can obtain suitable adapters. Perhaps they could build their own, or persuade one of the eBay adapter vendors to build a pair.


----------



## Scutey

gibosi said:


> The C3m has a 20V heater compared to 6.3V for the C3g. And further, the pin-out is different. However, those with the LD1+, which can run 20V 408A, should be able to run a pair of C3m providing they can obtain suitable adapters. Perhaps they could build their own, or persuade one of the eBay adapter vendors to build a pair.


 
 I guessed it had to be something like that, just a shame C3Gs aren't as plentifull as C3Ms, think i've reached the endgame with my mkiii, will just have to keep my eyes open for some more C3Gs. 
	

	
	
		
		

		
			





.


----------



## LugBug1

I used to own an amp based around the C3m tube. Very hard to find a couple of tubes that weren't noisy.. They get very hot as well as you can imagine with the voltage. Nice sound otherwise though... The amp was handmade by some German bloke I bought off online. The case was wood - I think if it had had metal housing it may have been too hot to touch.


----------



## Scutey

gibosi said:


> The C3m has a 20V heater compared to 6.3V for the C3g. And further, the pin-out is different. However, those with the LD1+, which can run 20V 408A, should be able to run a pair of C3m providing they can obtain suitable adapters. Perhaps they could build their own, or persuade one of the eBay adapter vendors to build a pair.


 
  
  


lugbug1 said:


> I used to own an amp based around the C3m tube. Very hard to find a couple of tubes that weren't noisy.. They get very hot as well as you can imagine with the voltage. Nice sound otherwise though... The amp was handmade by some German bloke I bought off online. The case was wood - I think if it had had metal housing it may have been too hot to touch.


 
 Well I think that's my question emphatically answered, don't want my LD MKIII overheating!, stick with the C3Gs, Thanks guys!.


----------



## gulakpi

lugbug1 said:


> I used to own an amp based around the C3m tube. Very hard to find a couple of tubes that weren't noisy.. They get very hot as well as you can imagine with the voltage. Nice sound otherwise though... The amp was handmade by some German bloke I bought off online. The case was wood - I think if it had had metal housing it may have been too hot to touch.


 
  
 I do not see there is much difference between the heater power between the C3g and C3m.   From their specifications, they use 2.35W and 2.5W respectively.  Will you kindly explain?  Any chance that the heat was caused by the ventilation of the wood cabinet?
 My C3g's are warm, but never hot.


----------



## LugBug1

gulakpi said:


> I do not see there is much difference between the heater power between the C3g and C3m.   From their specifications, they use 2.35W and 2.5W respectively.  Will you kindly explain?  Any chance that the heat was caused by the ventilation of the wood cabinet?
> My C3g's are warm, but never hot.


 
 If I could I would  The honest answer is I've no idea. I never built the amp, so... Just know it used to get very hot indeed. I've owned a few tube amps and none got as hot as that one


----------



## gibosi

gulakpi said:


> I do not see there is much difference between the heater power between the C3g and C3m.   From their specifications, they use 2.35W and 2.5W respectively.  Will you kindly explain?  Any chance that the heat was caused by the ventilation of the wood cabinet?
> My C3g's are warm, but never hot.


 
  
 One possible explanation is adapters. When we run C3g in our LD, the adapters provide a good bit of space and isolation between the tubes and the chassis. In that amp designed to run C3m, there is no isolation between the metal tube base and chassis. And it may well be that C3m amp was simply not designed to handle heat dissipation as well as the LD.
  
 Otherwise, I tend to agree. With the LD1+, a 408A running at 20V didn't seem any hotter than 6AK5 running at 6.3V. And in fact, the 408A is nothing more than a 6AK5 with a 20V heater. That is, these tubes are identical except for the heater.
  
 In my amp, the 6AH6 were the hottest.


----------



## djpeder

Has anyone tried Sylvania Gold Brand 1217 in LD I+?


----------



## gibosi

djpeder said:


> Has anyone tried Sylvania Gold Brand 1217 in LD I+?


 
  
 I have no idea what a 1217 is. Can you tell us more?


----------



## djpeder

​I read on page77 in this thread that you could use 1217 tubes(the same as 6BE6 tubes) in EF91 mode. Sylvania made some Gold Brand 1217 tubes. I wonder how these will sound. Today I am using some Mullard CV4014.


----------



## gibosi

djpeder said:


> ​I read on page77 in this thread that you could use 1217 tubes(the same as 6BE6 tubes) in EF91 mode. Sylvania made some Gold Brand 1217 tubes. I wonder how these will sound. Today I am using some Mullard CV4014.


 
  
 Searching back through this thread, I don't know that anyone tried the Sylvania 1217. However, the Sylvania 1217 should sound substantially the same as the Sylvania 6BE6. So if you can get a pair of the 1217 cheap, they are certainly worth trying. And then roll them in using EF91 and EF95 to see which setting you prefer.


----------



## Xicu

I'm currently looking at the drop for the Little Dot 1+, what is the difference in term of sound with the WE408 and 6CQ6 ? What would be the better choice if I'm mostly  listening to EDM, country and a bit of rock.


----------



## LugBug1

Does anyone have any experience or knowledge on these Russian tubes? Just looking at rolling options, the description does sound attractive. The link is below pic 
  
*4 pc matched 6J1P-EV (EF95 6F32 6AK7) gold platinum grid 1980's NEW NOS NIB!*
  

  
 http://www.ebay.co.uk/itm/4-pc-matched-6J1P-EV-EF95-6F32-6AK7-gold-platinum-grid-1980s-NEW-NOS-NIB-/111732434382?hash=item1a03c5a5cem62KC9qFxNIbo8xQ634CO2w


----------



## MIKELAP

lugbug1 said:


> Does anyone have any experience or knowledge on these Russian tubes? Just looking at rolling options, the description does sound attractive. The link is below pic
> 
> *4 pc matched 6J1P-EV (EF95 6F32 6AK7) gold platinum grid 1980's NEW NOS NIB!*
> 
> ...


 
 http://tubes-store.com/product_info.php?products_id=955


----------



## LugBug1

mikelap said:


> http://tubes-store.com/product_info.php?products_id=955


 
 Thank you!
  
 Now they don't look so attractive all of a sudden


----------



## MIKELAP

lugbug1 said:


> mikelap said:
> 
> 
> > http://tubes-store.com/product_info.php?products_id=955
> ...


 
 Got loads of tubes i tried in my MK3 you probably saw page 77 in the thread. Whats fun about them is they are cheap .NAD still going strong ?.


----------



## LugBug1

mikelap said:


> Got loads of tubes i tried in my MK3 you probably saw page 77 in the thread. Whats fun about them is they are cheap .NAD still going strong ?.


 
 Yes indeed my friend  
  
 My NAD amps are all I've used the last couple of years. I still recommend them highly as headphone amps. The thing is, I forget how good they sound when the impulse to try something new comes along. I always fall back on them.
  
 I see you've got both the top senns - I'm looking to possibly buy either the original again or the 's'. Undecided..  Enjoying the little brothers at the mo HD700


----------



## MIKELAP

lugbug1 said:


> mikelap said:
> 
> 
> > Got loads of tubes i tried in my MK3 you probably saw page 77 in the thread. Whats fun about them is they are cheap .NAD still going strong ?.
> ...


 
 I like the S model a little more bass a little less on top end ,i like em i sold the 800 sold a few thing due for an  update lol .Getting into guitars, you know what they say your never to old to Rock&Roll lol


----------



## TrollDragon

mikelap said:


> I like the S model a little more bass a little less on top end ,i like em i sold the 800 sold a few thing due for an  update lol .Getting into guitars, you know what they say your never _*to old to Rock&Roll*_ lol


 
  
 One of my favorite Tull tunes!


----------



## LugBug1

mikelap said:


> I like the S model a little more bass a little less on top end ,i like em i sold the 800 sold a few thing due for an  update lol .Getting into guitars, you know what they say your never to old to Rock&Roll lol


 
 Haha good for you! I used to play guitar - spent half my life playing in bands. Only got one guitar left from those days.. My trusty Fender Strat. An 80's model, black and white with maple neck. Love the tone of the Fenders. Used to use a les paul (sunburst red) as well which is great for rock and probably the coolest looking guitar ever designed. I'm a lefty so it was a nightmare trying to find guitars. Had to blind order my les paul without even trying it out! 
  
 What have you got up to now? (I'm sure the folk won't mind a little diversion to the subject of guitars) I used to have a tube amp for my Fender


----------



## MIKELAP

lugbug1 said:


> mikelap said:
> 
> 
> > I like the S model a little more bass a little less on top end ,i like em i sold the 800 sold a few thing due for an  update lol .Getting into guitars, you know what they say your never to old to Rock&Roll lol
> ...


 
 Im really basically just  starting out got myself a cigar box style guitar  and a  license plate style guitar 3 strings, but now eyeing a 6 string Gretsch Hollow Body G5422T i dont deserve to own a guitar like that but its so pleasing to the eye a classic so this one is in the works there's aLso   Brian Setzer Signature model 6120SLVO im looking at expensive though a few pictures


----------



## LugBug1

mikelap said:


> Im really basically just  starting out got myself a cigar box style guitar  and a  license plate style guitar 3 strings, but now eyeing a 6 string Gretsch Hollow Body G5422T i dont deserve to own a guitar like that but its so pleasing to the eye a classic so this one is in the works there's aLso   Brian Setzer Signature model 6120SLVO im looking at expensive though a few pictures


 
 Those are beautiful. I love the classic designs and the Gretsch are timeless. The guitar which I always wanted but never got round to getting was the Telecaster. My guitar heros are Hendrix and Jimmy Page. I remember when I was started out playing early gigs, all my musician friends and other bands I played with had Ibanez (Steve Vai) types and racks of effect pedals. I had my Strat, a boss distortion and Wah pedal plugged straight into a combo fender amp. Thats all I needed!! Good times 
  
 Guitars are beautiful toys and I can totally understand the collecting of them. (I used to sleep with my Fender...haha)


----------



## Scutey

Regarding the Electro Harmonix 6H30PI, they make my mkiii run pretty hot, does anybody know of any possible effects/lifespan on the mkiii?.


----------



## gibosi

scutey said:


> Regarding the Electro Harmonix 6H30PI, they make my mkiii run pretty hot, does anybody know of any possible effects/lifespan on the mkiii?.


 
  
 To state the obvious, tubes get hot, often very hot. As long as you are using tubes from the approved list, such as the 6H30PI, the LD was designed and built to handle this heat. IMO, worrying about the lifespan of the MKIII should be the least of your concerns.


----------



## Scutey

Thanks for that, at least I know for sure now , I wasn't worried more that I just wondered as the chassis gets quite hot compared to the 6N6/P/IR and 6SN7, so I thought as I didn't know for sure it was worth asking, and as always there is always someone who will know on Head-Fi, and in this case you, so thanks again!.


----------



## OctavianH

Does anyone 6J1P-EV are the same with 6ZH1P-EV?
  
 Found this offer on ebay and I am not sure if they are a good match:
 http://www.ebay.com/itm/LITTLE-DOT-MKII-MK-III-HEADPHONE-AMPLIFIER-ULTIMATE-VALVE-TUBE-UPGRADE-UK-STOCK-/252130624590?hash=item3ab428044e:gxgAAOSw5VFWI2YA


----------



## bogde

octavianh said:


> Does anyone 6J1P-EV are the same with 6ZH1P-EV?
> 
> Found this offer on ebay and I am not sure if they are a good match:
> http://www.ebay.com/itm/LITTLE-DOT-MKII-MK-III-HEADPHONE-AMPLIFIER-ULTIMATE-VALVE-TUBE-UPGRADE-UK-STOCK-/252130624590?hash=item3ab428044e:gxgAAOSw5VFWI2YA


 
 yes, most likely. see here: https://en.wikipedia.org/wiki/Russian_tube_designations
  

*Zh* (Russian: *Ж*) – sharp-cutoff pentode (also transliterated *sh* or *j*).

  
 and: http://www.radiomuseum.org/tubes/tube_6j1p-ev.html


----------



## Oskari

oskari said:


> The Russian designation is 6Ж1П-ЕВ.
> 
> 6Zh1P-EV and 6J1P-EV are merely transliterations of that.


----------



## OctavianH

Thanks for clarifications. I ordered them.
  
 Any advice for a good DAC to this little amp? I think to keep my NFB11 for the A5X and HD650 and to add a new DAC to the Littledot MKII. I wouold prefer a small USB only one with 2 RCA (don't need anything more).
  
 I read something interesting about HRT Music Streamer II+ but unfortunately I cannot order it in my country. We will see if I manage to order it in another way.


----------



## Share2Care

Morning Gents & Ladies.
  
 I am the proud order of the beast that is the Little Dot MK1. As I have spent a long time looking into this amp, tubes, tube types and tube rolling it does feel for every hour gained, another 2 hours land back in its place! I of course do not mind this as I love to learn, especially about one of my few passions!
  
 THe long and short is that from the excellent review, I sourced some matched Mullard 8100 tubes. I am based in the UK and am really interested in a variety of tubes to get a feel for any differences that may make themselves apparent. The reason why I say I am in the UK is that a UK source would be great, but no the end of the World! Also, there was mentioned in the review a back plate tube which leant more towards more bass.I would love to try this, amongst many others.
  
 Any and all help, advice and guidance would be wholeheartedly appreciated with a source of where to buy the tubes at a reasonable price as many are rather pricey. Pricey is fine if they are worth it, are truly matched etc, but I do not have much faith in any suppliers. 
  
 I am most certainly falling in love with this little amp! Last thing is if anyone has available tubes etc, and want to help a new tube user I would be over the moon and if required, I am happy to buy from any trusted source.
  
 Thank you very much.


----------



## OctavianH

Hi,
  
 These guys seem reliable, but I haven't ordered anything from them. They have a list of nice upgrade kits for several types of Little dots, and I plan to take one for them for my own MKII. I like the details they provide and they seem to be a good option.
  
 https://www.watfordvalves.com/products.asp?ID=35&man=347


----------



## gulakpi

I recommend Langrex highly - they are in the UK!
 They have very good services and good prices!  I bought from them several times.
 BTW:  the Little Dot does not require matched pairs to work well.


----------



## frogmeat69

gulakpi said:


> I recommend Langrex highly - they are in the UK!
> They have very good services and good prices!  I bought from them several times.
> BTW:  the Little Dot does not require matched pairs to work well.


 

 +1, Langrex is very good!!


----------



## OctavianH

Just received my russians babies from ebay (sent from UK):
  

  
 The left ones are the 6N6P and the right ones are the 6J1P-EV. I guess the red pads are for the power tubes? to put them under them for isolation?
  

  
 I will try them lately this weekend and inform about the improvement compared to the stock tubes.
 What I would like to have is more detail and clear bass, because on the chinese ones is quite distorted (maybe not enough burn in time).
 We will see how pleased I will be with these ones.
  
 Later Edit:
  
 I found my answer:
  


> You will receive a fully matched and tested set with a free pair of silicone dampers for use with the 6J1P-EV for improved microphonics.
> These valves are pre-burnt in, however, please allow 20hrs running in time for full benefit. You may hear some pops and hiss at first, this is normal and they will usually settle down quite quickly.
> 
> These valves will transform the sound of your amplifier.


 
  
 So silicone dampers for the drivers. Are these really improving sound?


----------



## bogde

> So silicone dampers for the drivers. Are these really improving sound?


 
 supposedly, those should reduce microphonics. for instance if you touch the tubes while the amp is running you may hear an undesired noise in the headphones. but that may also happen due to some other type of mechanical vibration and those rings should somewhat help with reducing that.


----------



## OctavianH

Ah ok, well, the Little Dot itself is very stable, and the tubes are quite hot. I am not touching them, but I will mount these if they were provided.


----------



## bogde

octavianh said:


> Ah ok, well, the Little Dot itself is very stable, and the tubes are quite hot. I am not touching them, but I will mount these if they were provided.


 
 yeah, i was trying to describe what "microphonic" means. some tubes may even pick up noise in the room, like whistle noise and such. enjoy your new tubes!


----------



## LugBug1

share2care said:


> Morning Gents & Ladies.
> 
> I am the proud order of the beast that is the Little Dot MK1. As I have spent a long time looking into this amp, tubes, tube types and tube rolling it does feel for every hour gained, another 2 hours land back in its place! I of course do not mind this as I love to learn, especially about one of my few passions!
> 
> ...


 
 Congrats on the amp! Those Mullard tubes should do you nicely for starters  Here's a few that I've tried with the LD1.
  
 Mullard EF95 8100- Very popular. Big warm bass  - treble is nice but there are smoother options. Warmth can colour the sound and you do lose detail in the lower fr. 
 Mullard EF92  8161 - Warm but much better controlled sound - more neutral. Very quiet. May be boring for some. (probs my favourite) 
 Mullard EF91 8083 - Lifted in both the top and bottom fr compared to the EF92 and also not quite as refined. I really liked these and they are cheap as chips. 
 Western Electric 408A - Similar balance to EF95 but with a little better control and refinement. Not worth the cost of shipping from US IMO.


----------



## Share2Care

Thank you for the information ladies & gents. 

Advice will be followed and will come back with my thoughts and feelings. 

On another note, I am IN NEED of a Darkvoice 336SE. I missed the Massdrop but am looking for anyone who is selling. Please contact me for a rapid sale! 

Much Appreciated


----------



## OctavianH

Heard that the Darkvoice is more forgiving than the Little Dot. But never owned one. Any opinions on that? Which one is better and for what?


----------



## i luvmusic 2

I'am wondering how the Darkvoice 336 compare to BH CRACK............Anyone?


----------



## BoHan700

I use a Cambridge Audio Dac Magic Plus. It is an upgrade from my Schitt Modi 2. The CADM+ really made a huge difference with my MK3. I'm still running the Stock tubes and it sounds Fantastic.


----------



## OctavianH

lugbug1 said:


> Congrats on the amp! Those Mullard tubes should do you nicely for starters  Here's a few that I've tried with the LD1.
> 
> Mullard EF95 8100- Very popular. Big warm bass  - treble is nice but there are smoother options. Warmth can colour the sound and you do lose detail in the lower fr.
> Mullard EF92  8161 - Warm but much better controlled sound - more neutral. Very quiet. May be boring for some. (probs my favourite)
> ...


 
  
 So the most controlled and clear ones are the 8161? Better than 8083? I upgraded recently to russian ones (6ZH1P-EV) and I am quite pleased, but I am not 100% pleased with the detail, for example in the cymbal section. I still feel some distort or lack of detail.
 For rock/fast/intense music which Mullard are you recommending from the 3 pairs you owned and described? Thanks in advance.


----------



## LugBug1

octavianh said:


> So the most controlled and clear ones are the 8161? Better than 8083? I upgraded recently to russian ones (6ZH1P-EV) and I am quite pleased, but I am not 100% pleased with the detail, for example in the cymbal section. I still feel some distort or lack of detail.
> For rock/fast/intense music which Mullard are you recommending from the 3 pairs you owned and described? Thanks in advance.



Yes mate i'd recommend the ef92. Great control through out the frequencies and bcause of the very black background details seem to come through better. They're also quite smooth aswell so not aggressive in treble.


----------



## OctavianH

lugbug1 said:


> Yes mate i'd recommend the ef92. Great control through out the frequencies and bcause of the very black background details seem to come through better. They're also quite smooth aswell so not aggressive in treble.


 
  
 OK, I will add them to my next "to buy" list. In the meantime I will change the iDAC2 to audio-gd NFB11 to see if the problem is not coming from the DAC side (iDAC2 to be to "warm" and distorted for my taste in conjunction with the Littledot and russian tubes). If this helps, I can use iDAC2 as a simple pre-amp for my A5X (current job of NFB11). But still, EF92 ones will remain on a "to buy" list.


----------



## bharat2580

I feel the 92'lack the dynamics of the 95s. They are rolled off and dull. My LD mk iii lost its verginity to them. 

Now i have the mk iv se with the mullards ef95 and the 6n6p-ir. The EH gold pins are sibilant and have too much treble energyfor me


----------



## OctavianH

I think I am going to try them. I am reluctant to 8100 for "extra bass" and V-shape. I had the same problem with HD650 vs HD600 and I kept the last one.
 Regarding dynamics, I don't know what to say...


----------



## BoHan700

​Hi Mike- I'm new to this forum. I have read quite a bit. You appear in many posts, and it appears that your advice is very good. I have a question for you. (I'm sure it's been answered 100 times within the 700+ pages of posts ) but I'd like to get a direct answer from you on a recommendation. I have Sennheiser HD 700's. I am running Tidal off my PC. I have a Cambridge audio Dac Magic Plus running into my Little Dot III. From where I started a few months ago, This to me is a great sounding setup. Although I am starting to listen more and feel I am not getting everything available. I enjoy all sorts of music. From Classic Rock, Jazz Classics, and Classical Piano. Female Jazz Vocals Norah Jones and Diana Krall.
 My question is this. Without having to re strap, change ,alter, rewire or do any beyond taking out the existing, and replacing them......What tubes would you reccomend I get to maximize the LDMk3 with my HD 700's.
  
 Thanks


----------



## OctavianH

Question related to the power tubes:
  
 I see in the main post of this thread:
  


> So here’s my short list: I would recommend the Voshkod 6ZH1P-EV as the best place to start as it is a clear upgrade from the stock tubes, followed by the Mullard M8083 for its impressive treble clarity and top-octave ‘air’ (provided you have matched power tubes).


 
  
 M8083 need different power tubes than the others?
  
 Any difference between "6H6PI/6H6N Novosibirsk NEVZ-Soyuz" and "6N6P NEVS, Novosibirsk"?
  
 From what I knew, MKII uses the same power tubes for all EF91,EF92 and EF95 families, and 6H6PI or 6N6P are quite the same, no impact on sound or something else.


----------



## LugBug1

bharat2580 said:


> I feel the 92'lack the dynamics of the 95s. They are rolled off and dull. My LD mk iii lost its verginity to them.
> 
> Now i have the mk iv se with the mullards ef95 and the 6n6p-ir. The EH gold pins are sibilant and have too much treble energyfor me


 
 Yes, like I said earlier I can understand some finding the EF92 boring. Suppose everything in the chain needs to be considered. I'm currently using the HD700 and LD MK2 at the mo and the bass was ruined with the EF95.. Really quite bloated and details were lost. The EF92 has tightened the bass up considerably and the freq's top to bottom seem flatter - more natural. I'm rebuying some HD600 so I'll see how they get on with both EF95 and EF92.


----------



## OctavianH

I ordered some Mullard M8161 and some Siemens 5654W. I am too curious to try them. For me HD600 are somehow warm, coming from years of "beyer sound". But I like them because they are relaxing and decently clear. I think the most analitic sound is the Beyer one, incredible headphones for complex passages. I will see how M8161 will sound to me, it seems I am more one the neutral side than the others, who enjoy HD650 and consider HD600 neutral. We will see.


----------



## BoHan700

I'm new to this forum. I have read quite a bit. You appear in many posts, and it appears that your advice is very good. I have a question for you. (I'm sure it's been answered 100 times within the 700+ pages of posts ) but I'd like to get a direct answer from you on a recommendation. I have Sennheiser HD 700's. I am running Tidal off my PC. I have a Cambridge audio Dac Magic Plus running into my Little Dot III. From where I started a few months ago, This to me is a great sounding setup. Although I am starting to listen more and feel I am not getting everything available. I enjoy all sorts of music. From Classic Rock, Jazz Classics, and Classical Piano. Female Jazz Vocals Norah Jones and Diana Krall.
 My question is this. Without having to re strap, change ,alter, rewire or do any beyond taking out the existing, and replacing them......What tubes would you reccomend I get to maximize the LDMk3 with my HD 700's.


----------



## TrollDragon

bohan700 said:


> I'm new to this forum. I have read quite a bit. You appear in many posts, and it appears that your advice is very good. I have a question for you. (I'm sure it's been answered 100 times within the 700+ pages of posts ) but I'd like to get a direct answer from you on a recommendation. I have Sennheiser HD 700's. I am running Tidal off my PC. I have a Cambridge audio Dac Magic Plus running into my Little Dot III. From where I started a few months ago, This to me is a great sounding setup. Although I am starting to listen more and feel I am not getting everything available. I enjoy all sorts of music. From Classic Rock, Jazz Classics, and Classical Piano. Female Jazz Vocals Norah Jones and Diana Krall.
> My question is this. Without having to re strap, change ,alter, rewire or do any beyond taking out the existing, and replacing them......What tubes would you reccomend I get to maximize the LDMk3 with my HD 700's.


 
 A good and inexpensive start would be the 6HM5 tall tubes, they are a great upgrade from stock drivers. Other than those I would suggest going directly to the "end game" C3g's and adapters, but they might be a little hard to find.
  
 Yugoslavia 6HM5
 http://www.ebay.com/itm/6HM5-6HA5-EC900-export-quality-audio-triode-tube-NOS-FREE-SHIPPING/300879467071

 With tube sound being 90% personal preference, it will be a hard choice to recommend what tubes will sound great to you.


----------



## ScottieB

A few years back I had a LD MKIII, and tried all kinds of tubes for it. I found overall that the EF95 type (and equivalents) sounded better to me than the EF92/91 styles. My MKIII died a couple years ago and a few weeks ago I replaced it with a (slightly used) MKIV SE. Now when I try the 92/91 style tubes I really like how they sound. They don't have the dynamics of the EF95's but the extended bass is quite nice. I remember it being more boomy and less controlled with the MKIII (these are the same tubes).
  
 Is it possible that it's the extra oomph of the MKIV and it's upgraded power tubes (from the MKIII) really allow the EF92/91 to shine?


----------



## bharat2580

bohan700 said:


> I'm new to this forum. I have read quite a bit. You appear in many posts, and it appears that your advice is very good. I have a question for you. (I'm sure it's been answered 100 times within the 700+ pages of posts ) but I'd like to get a direct answer from you on a recommendation. I have Sennheiser HD 700's. I am running Tidal off my PC. I have a Cambridge audio Dac Magic Plus running into my Little Dot III. From where I started a few months ago, This to me is a great sounding setup. Although I am starting to listen more and feel I am not getting everything available. I enjoy all sorts of music. From Classic Rock, Jazz Classics, and Classical Piano. Female Jazz Vocals Norah Jones and Diana Krall.
> My question is this. Without having to re strap, change ,alter, rewire or do any beyond taking out the existing, and replacing them......What tubes would you reccomend I get to maximize the LDMk3 with my HD 700's.


 
 6n6p-ir
 mullards ef95 ,m8xxx


----------



## Scutey

bohan700 said:


> I'm new to this forum. I have read quite a bit. You appear in many posts, and it appears that your advice is very good. I have a question for you. (I'm sure it's been answered 100 times within the 700+ pages of posts ) but I'd like to get a direct answer from you on a recommendation. I have Sennheiser HD 700's. I am running Tidal off my PC. I have a Cambridge audio Dac Magic Plus running into my Little Dot III. From where I started a few months ago, This to me is a great sounding setup. Although I am starting to listen more and feel I am not getting everything available. I enjoy all sorts of music. From Classic Rock, Jazz Classics, and Classical Piano. Female Jazz Vocals Norah Jones and Diana Krall.
> My question is this. Without having to re strap, change ,alter, rewire or do any beyond taking out the existing, and replacing them......What tubes would you reccomend I get to maximize the LDMk3 with my HD 700's.


 

 ​For powers definitely the 6N6P-IR or 6SN7 (with adapters), for drivers I can only agree with TrollDragon that the C3G is the pinnacle for the LDMK3, the clarity, detail, imaging, and bass are by far the best I've heard, however they are rare and expensive.


----------



## OctavianH

Anyone tried MKII with T1 or any 600 Ohm headphone? Works ok?


----------



## J Mirra

octavianh said:


> Anyone tried MKII with T1 or any 600 Ohm headphone? Works ok?


 

 Yes I use the MKII with the T1 1.1 with the Mullard 8100 and 6N6P-IR and it sounds great, so liquid with the highs tamed.


----------



## HungryPanda

I have a MKII  and use is it with the T1.2 with either Mullard 8100  or Voskhod 6J1P-EV if wanting a brighter sound


----------



## OctavianH

I was thinking to sell my T5p because lately I am not travelling a lot, and to buy a T1.2 but I was not sure if the MK2 is enough.
 I own Voskhod 6J1P-EV, but I was expecting to be too bright with the T1.2. Of course, my plan depends of the price I get for the T5p because it does not make sense to give them in perfect condition under 500EUR. I am still reading and finding out that they made some "sound enhancements" for the 2nd version I am not sure what impact has that on the sound.


----------



## HungryPanda

I love the T1.2 it is a great headphone


----------



## LugBug1

scottieb said:


> A few years back I had a LD MKIII, and tried all kinds of tubes for it. I found overall that the EF95 type (and equivalents) sounded better to me than the EF92/91 styles. My MKIII died a couple years ago and a few weeks ago I replaced it with a (slightly used) MKIV SE. Now when I try the 92/91 style tubes I really like how they sound. They don't have the dynamics of the EF95's but the extended bass is quite nice. I remember it being more boomy and less controlled with the MKIII (these are the same tubes).
> 
> Is it possible that it's the extra oomph of the MKIV and it's upgraded power tubes (from the MKIII) really allow the EF92/91 to shine?


 
 Quite possibly. My experience with the EF92 (on my lowly MKII) is that the bass is considerably tighter, the EF95 by contrast are the boomy ones.. I found the more burned in the EF95 where, the boomier they got. They just kept getting warmer! 
  
 Must stress that there two types of Mullard EF92 and they sound different. The first post lists them and I more or less agree with the description. The M8161 are the ones that I use and I find these ones to be more controlled and less coloured.


----------



## ScottieB

Yeah cool - I have those too the M8161's -- I didn't like them much with my MKIII, but since I am really enjoying the EF91's (Sonotone I think - will have to check later) I'm ready to give the 92's a chance again too. Plus they just look cooler!


----------



## OctavianH

What power tubes do you use with EF92? Do they make any change to the sound?


----------



## LugBug1

octavianh said:


> What power tubes do you use with EF92? Do they make any change to the sound?




Mine are 6n6p russian. Cant say because l changed the chinese ones straight away as one of the tubes was DOA. Havent tried any others.


----------



## Typhoon859

Any Genalex - Gold Lion ​tubes compatible with Little Dot MK III?​


----------



## TrollDragon

typhoon859 said:


> Any Genalex - Gold Lion ​tubes compatible with Little Dot MK III?​


 

 Not without a heavily modified adapter. Those are all dual triodes and the LD needs single triodes or strapped pentodes etc...


----------



## ScottieB

So I do have Sonotone EF91's but the ones I was enjoying all this week were actually Ediswan CV138's, which I believe are an EF91 equivalent. I could be wrong. I've now got the M8161's in there, and they sound much better than I recall on my MKIII. (I'm using my HD600s for all of this by the way). The Mullards (M8161) are a bit more controlled, while the Ediswans were more 'fun' especially with rock music. They really brought out the lower end like the EF95's usually didn't, though they sacrifice some detail. So, it could be that the MKIV se is better with these tubes, or maybe my ears have simply evolved lol.
  
 Can someone tell me the basic differences between the EF92/91 and EF95's? Is it true the EF92/91 require more current? I thought I read that somewhere. That's what I'm basing the assumption that the MKIV works better with them on... it certainly has more oomph that the MKIII did.
  
 There's not a ton of info out there on these tube, and what there is isn't the most easily approachable, so I appreciate any info!
  
 edit: according to this the CV138 is the military version of the EF91: http://www.mullardmagic.co.uk/cv138-military-variant-of-the-ef91-6am6-z77-valve-for-little-dot-amp


----------



## LugBug1

scottieb said:


> Can someone tell me the basic differences between the EF92/91 and EF95's? Is it true the EF92/91 require more current? I thought I read that somewhere. That's what I'm basing the assumption that the MKIV works better with them on... it certainly has more oomph that the MKIII did.


 
 IME, EF95 are fun sounding, big warm bass with slight edge in treble. EF92 (8161) more neutral and balanced - bass is especially more controlled - treble has a more rounded sound -less edge very quiet tube. EF91 is a less refined EF92 with more bass and treble. (kind of the best of both worlds but not as good as either... If that makes sense.)
  
 The EF92 require more power than the EF95 and the EF91 require more power than both. The EF92/91 require a short circuit with jumpers in place (not the woolly kind you wear on a cold day  sorry little joke there...) And the EF95 require an open circuit with no jumper. The more power the tube requires, the hotter your machine will get. With higher end Little dots this should not be an issue. 
  
 On paper I would be looking to use the more powerful tube with the highest impedance headphones. EF95 are great with Grado etc. But I prefer EF92/91 with Sennheiser.
  
 This is just my experience with these tubes...


----------



## ScottieB

Of course, one man's 'fun' is another's 'boring' but yeah I think we are mostly on the same page. The synergy with the music and the headphones (and maybe even the source?) can affect all of these things as well but to me that just makes it more fun to talk about and try different combos. Tubes are so fun!
  
 It totally makes sense, then, too that the 92/91 style tubes would sound better on my MKIV than I remember on the MKIII (though admittedly it was a while ago). I was quite surprised at how much bigger the MKIV is! And it doesn't get nearly as warm. Lol also the bigger EF92/91 tubes are much easier to roll in the MKIV - those tube guards (or whatever you call them) make the EF95's kind of a bitch to remove! 
  
 Can you tell me more about what is actually happening when I move the jumper for the EF92/91? Is it bypassing something? Or adding something to the signal path?


----------



## OctavianH

Rockin' my pair of EF92 Mullard 8161 ordered from Langrex. Very good service and fast delivery. So I recommend them to anyone.
  
 Here are sitting near my previous Voskhod EF95 6J1P-EV.
  

  
 And here "on the job":
  

  
 Honestly I like them, and I do not feel them dull. I think it depends on the type on music and the rest of the setup.
  
 In my case, with NFB11 as a DAC and HD600 as the headphones sound really nice, very clear but somehow "mellow".
  
 The music is a kind of 70-80s prog rock, so a lot of guitar, cymbals and sometime piano and complex instrumental work.
  
 Works really well in this setup with this kind of music.


----------



## TontoGoldstein

Hello, new to the site. Today I received an MK2 and I've already ordered JAN 5654W tubes to replace the stock. Did I order replacements for the little ones in the front or the big ones in the back? Question 2: I'm using this as a PreAmp, not a headphone amp, do I need to replace the power tubes? Would that make any difference?


----------



## LugBug1

tontogoldstein said:


> Hello, new to the site. Today I received an MK2 and I've already ordered JAN 5654W tubes to replace the stock. Did I order replacements for the little ones in the front or the big ones in the back? Question 2: I'm using this as a PreAmp, not a headphone amp, do I need to replace the power tubes? Would that make any difference?


 
 The Jan tubes are driver ones and are the little ones at the front. You don't need to replace power ones if you are happy with them. If you do then you can't go wrong with Russian 6n6p these are popular and fairly cheap.
  
 Just make sure your power amp is not DC coupled when using the LD as a pre, as the results can be disastrous. Its mentioned in the manual. Enjoy


----------



## Share2Care

Good Afternoon Ladies & Gents. 

As tube rolling is starting to infiltrate my mind, I jad a Little Red Dot MK1. Picked up a few different tubes as I am looking forward to see the amount of differences with of course keeping burn and quality of music being played. What a terrible day having to listen to tunes all day and warm up my hands on the tubes (not touching of course lol!) 

Need some advice please. Looking to purchase two matched pairs of this tube RCA 5654 (Black Plate) Good for a range but lows and bass seem to be mentioned. Are any of these tubes Russian or were Russian made at any point as I have someone who is so kind to match and send it over. 

So thanks for the advice. It is appreciated


----------



## Whelkie D

Yes Mordy, I've just swapped the stock Chinese power tubes on the LD MK2 for some Soviet 6N6P ones. There is a huge difference to the bass - sounds much fuller. I wasn't expecting such a huge difference as people had said that the power tubes don't really alter sound quality. Would recommend upgrading them as well as the driver tubes.


----------



## NotSoTastyPi

Hey guys, any tips on power tube replacements? I am already rockin' M8100 on my mk2 + Hd600's and i love it. Thought about adding some 6N6P* *ECC99 because ive heard the lows and mids are the best, anyone had any experience with those?


----------



## dobigstuff

scutey said:


> Regarding the Electro Harmonix 6H30PI, they make my mkiii run pretty hot, does anybody know of any possible effects/lifespan on the mkiii?.


 
 Scutey:
  
 I use my HD 700's with a Little Dot MK III with these tubes:  
  
 Electro-Harmonix 6H30Pi for the Power Tubes. 
 Telefunken 5654 for the Driver Tubes.   
  
 Sounds Awesome.  Tight Bass.    
 (I also use an MIT Magnum Power Cord and MIT Matrix 6 Interconnects)
  
 Thx


----------



## ScottieB

Does the MKIII need a mod for the 6h30-PI tubes? Or did they maybe change it? I'm pretty sure back in the day at least (like 2008/2009) it needed a mod, and trying to run those tubes in my MKIII is what killed it (though it worked for a couple weeks). Sorry - don't want to add any confusion I'm legit curious!


----------



## OctavianH

Would be very nice if someone can update the main post with new info, there are a lot of tubes missing which are described here, for example Telefunken and Siemens and so on..
  
 In the meantime I plan to buy some Beyers T1.2 600Ohm. Let's hope I will not regret this decision.


----------



## dobigstuff

scottieb said:


> Does the MKIII need a mod for the 6h30-PI tubes? Or did they maybe change it? I'm pretty sure back in the day at least (like 2008/2009) it needed a mod, and trying to run those tubes in my MKIII is what killed it (though it worked for a couple weeks). Sorry - don't want to add any confusion I'm legit curious!


 
 ScottieB:
  
 I did not have to adjust settings nor did the Little Dot III need any Mod.  Sorry I don't know the year of manufacture.


----------



## Share2Care

share2care said:


> Good Afternoon Ladies & Gents.
> 
> Need some advice please. Looking to purchase two matched pairs of this tube RCA 5654 (Black Plate) Good for a range but lows and bass seem to be mentioned. Are any of these tubes Russian or were Russian made at any point as I have someone who is so kind to match and send it over.
> 
> So thanks for the advice. It is appreciated




Any help please?


----------



## MIKELAP

share2care said:


> share2care said:
> 
> 
> > Good Afternoon Ladies & Gents.
> ...


 
 Its a well known  fact that you do not need matched pairs in these amps


----------



## MIKELAP

dobigstuff said:


> scottieb said:
> 
> 
> > Does the MKIII need a mod for the 6h30-PI tubes? Or did they maybe change it? I'm pretty sure back in the day at least (like 2008/2009) it needed a mod, and trying to run those tubes in my MKIII is what killed it (though it worked for a couple weeks). Sorry - don't want to add any confusion I'm legit curious!
> ...


 
  


dobigstuff said:


> scottieb said:
> 
> 
> > Does the MKIII need a mod for the 6h30-PI tubes? Or did they maybe change it? I'm pretty sure back in the day at least (like 2008/2009) it needed a mod, and trying to run those tubes in my MKIII is what killed it (though it worked for a couple weeks). Sorry - don't want to add any confusion I'm legit curious!
> ...


 
 i own a Littledot MK3 and  my board is version v2.0 and i can use the 6H30PI with it . you can find your version # by looking under the amp with volume knob on top (north) and to the top right of the amp with a flashlight look in hole towards the side of the board and you should see your version


----------



## MIKELAP

This is v1.0 cannot use the 6H30PI tubes with this version


----------



## dobigstuff

Thanks for your help!!!


----------



## dobigstuff

share2care said:


> Any help please?


 

 Share2Care:
  
 These are excellent Driver Tubes:
  
 Telefunken 5654.  Also the Jan 5654 sound great as well.
  
 I hope this helps.


----------



## Scutey

Has anybody used or had any experience with the Foton 6N6P in a LD MK3 or any LD?,  just wondered as I've noticed some for sale on ebay and I can't say I've seen a Foton version before.


----------



## TontoGoldstein

_Just make sure your power amp is not DC coupled when using the LD as a pre, as the results can be disastrous. Its mentioned in the manual. Enjoy  _
  
 Lugbug, I don't know what the sh!t DC coupled means but luckily my setup sounds great, so I guess my QSC RMX 1450 isn't DC coupled but one thing it is, is badass. 240 wpc fed from the MK2. 
  
 I just got the JAN 5654W tubes installed and I swear it sounds better. Before I had the treble turned down because it was grating and even started browsing for tweeter upgrades (I still might) but now I have the treble turned back to flat on the iTunes EQ and it sounds clear. I'll know if it's a placebo effect because I don't like overly bright music and eventually I'll turn it down if it bothers me. 
  
*Question: is there a burn in time for the JAN 5654W tubes like the stock tubes? *
  
 Love this forum, I've discovered a whole new world with tubes. However, I think I'm done, these JAN 5654W tubes sound great and could be the end of the road for me.


----------



## Brumas7

I have seen the warning about not using the LD Mk3 with a DC-coupled power amp and always wondered what/how can I tell what is a DC-coupled amp. So I didn't dare to hook up my LD mk3 as a pre-amp to the NAD integrated amp C356BEE that I am using in my simple main system for fear of blowing my speakers. Can anyone tell me if it is safe for me to hook up the LD mk3 into the power amp section of the NAD 356BEE? I got this amp a few years ago particularly because the pre-amp and power amp sections could be used separately.


----------



## Flex2d

Hi I bought these on ebay :  *MATCHED Pair 6Z1P-EV 6J1 NOS Audio Little Bear NOS EF95*  
 and they arrived today, but they dont have the same markings, on the wrappings of the tube the person has stated para 11 but when i opened them one had 11 marking and the other 18!?
  
 Im guessing they are not the same batch and the same yuear and probably not going to sound the same even though they are matched.. could someone advise me as i am new to the tube rolling business and aprehensive to use them?
 should i send them back?
  
 I also noticed the writing looks to be worn off and the lettering can only just be made out. they are both different again.
  
 one ends in X1-76 and the other tube is 05-83
  
 I'm guessing they are not the same tubes..
  
 Any advise greatly appreciated.
  
 Thanks
  
 Daniel
  
 edit: they are to be used in my new LD mk2


----------



## Whelkie D

brumas7 said:


> I have seen the warning about not using the LD Mk3 with a DC-coupled power amp and always wondered what/how can I tell what is a DC-coupled amp. So I didn't dare to hook up my LD mk3 as a pre-amp to the NAD integrated amp C356BEE that I am using in my simple main system for fear of blowing my speakers. Can anyone tell me if it is safe for me to hook up the LD mk3 into the power amp section of the NAD 356BEE? I got this amp a few years ago particularly because the pre-amp and power amp sections could be used separately.


 
 I've been playing my LD MK2 through the "Main amp" section of a NAD 320 BEE without any problems (so far), bypassing the preamp section of the NAD. I assumed this was OK but I'm not so sure now. Is this a disaster waiting to happen?


----------



## Share2Care

dobigstuff said:


> Share2Care:
> 
> These are excellent Driver Tubes:
> 
> ...


 
 Thank you kind Sir!
  
 Would those be their full names for searching? I am a complete noob but looking forward to tubes and solids being part of my setups. Best website to get them from as I am in the UK but am used to ordering World Wide.
  
 Lastly, the tubes on a little MK1, should they be matched? Better sound? Better acoustics after burn in? Bettor life of the tube or just pick two of the same, roughly same year and good to go LOL?    I see many different views on this. Would matching be more important in high end amps?
  
 Thank you my friend! 
  
 Cheers


----------



## dobigstuff

share2care said:


> Thank you kind Sir!
> 
> Would those be their full names for searching? I am a complete noob but looking forward to tubes and solids being part of my setups. Best website to get them from as I am in the UK but am used to ordering World Wide.
> 
> ...


 

 Share2Care:
  
 Just search 5654 Tubes (Tube Depot is one good place) and many brands will come up in the search.  Get a matched pair.  If you get them from Tube Depot you can select High Gain, Low noise and Matched Pairs on some of their tubes.
  
 Good Luck


----------



## dobigstuff

tontogoldstein said:


> _Just make sure your power amp is not DC coupled when using the LD as a pre, as the results can be disastrous. Its mentioned in the manual. Enjoy  _
> 
> Lugbug, I don't know what the sh!t DC coupled means but luckily my setup sounds great, so I guess my QSC RMX 1450 isn't DC coupled but one thing it is, is badass. 240 wpc fed from the MK2.
> 
> ...


 

 TontoGoldstein:
  
 Those Jan 5654 are awesome.  They will need some break in as did the stock tubes.  Just check the Little Dot user guide as they don't recommend lengthy burn-in for many hours straight.
  
 Happy Listening!


----------



## TrollDragon

share2care said:


> Thank you kind Sir!
> 
> Would those be their full names for searching? I am a complete noob but looking forward to tubes and solids being part of my setups. Best website to get them from as I am in the UK but am used to ordering World Wide.
> 
> ...


 

 Matched tubes are NOT required for a LD MK1/2/3/4, matching preamp tubes is a way for the vendor to get an extra $5-$10 from you, that's all. Power tubes that are in a Push/Pull configuration must be matched to equalize the pairs current. Our LD amps do not use power tubes and are not in a Push/Pull configuration.

 Matched pairs of preamp tubes will not sound better or last longer than a pair that is not matched.


----------



## Share2Care

trolldragon said:


> Matched tubes are NOT required for a LD MK1/2/3/4, matching preamp tubes is a way for the vendor to get an extra $5-$10 from you, that's all. Power tubes that are in a Push/Pull configuration must be matched to equalize the pairs current. Our LD amps do not use power tubes and are not in a Push/Pull configuration.
> 
> Matched pairs of preamp tubes will not sound better or last longer than a pair that is not matched.


 
  
 Really appreciate the straight forward clarification @TrollDragon on the Little Do MK1. I have been reading posts fter posts, reviews after reviews and some is subjective, some really do make a difference but I never could understand a worthwhile improvement on a Little Dot MK1.
  
 I will be getting a Darkvoice 336SE OTL very shortly. May be needing some more tube guidance I am afraid. Do not want to be a burden or annoying but believe tubes really do play a role!
  
 Thanks for your help.


----------



## dobigstuff

trolldragon said:


> Matched tubes are NOT required for a LD MK1/2/3/4, matching preamp tubes is a way for the vendor to get an extra $5-$10 from you, that's all. Power tubes that are in a Push/Pull configuration must be matched to equalize the pairs current. Our LD amps do not use power tubes and are not in a Push/Pull configuration.
> 
> Matched pairs of preamp tubes will not sound better or last longer than a pair that is not matched.


 
 TollDragon:
  
 Thanks for the clarification.  I just thought a matched pair would be better than an unmatched pair (that is if the pair is way off with bench measurements)
  
 Thanks again.


----------



## TrollDragon

tontogoldstein said:


> _Just make sure your power amp is not DC coupled when using the LD as a pre, as the results can be disastrous. Its mentioned in the manual. Enjoy  _
> 
> Lugbug, I don't know what the sh!t DC coupled means but luckily my setup sounds great, so I guess my QSC RMX 1450 isn't DC coupled but one thing it is, is badass. 240 wpc fed from the MK2.
> 
> ...


 
 Your RMX 1450 is DC coupled, but it is supposed to have protection according to the QSC website.
  
 Quote: QSC 





> Independent DC and thermal overload protection on each channel automatically protects amplifier and speakers.


 

 DC coupling won't make it sound good or bad either way. The problem with DC coupled amp hooked to the LD is if you encounter a catastrophic failure on one of the output tubes, the LD can  send 150V+ out the RCA jacks and into your amplifier. This will take out the complete amplifier and your speakers in a split second. The warning is put in the manual surrounded by a box for a reason, not to be taken lightly by any means.


----------



## TrollDragon

brumas7 said:


> I have seen the warning about not using the LD Mk3 with a DC-coupled power amp and always wondered what/how can I tell what is a DC-coupled amp. So I didn't dare to hook up my LD mk3 as a pre-amp to the NAD integrated amp C356BEE that I am using in my simple main system for fear of blowing my speakers. Can anyone tell me if it is safe for me to hook up the LD mk3 into the power amp section of the NAD 356BEE? I got this amp a few years ago particularly because the pre-amp and power amp sections could be used separately.


 
  
  


whelkie d said:


> I've been playing my LD MK2 through the "Main amp" section of a NAD 320 BEE without any problems (so far), bypassing the preamp section of the NAD. I assumed this was OK but I'm not so sure now. Is this a disaster waiting to happen?


 
  
 You guys would have to contact NAD and see if your amps are DC or not. The chance of the LD failing so that it would take out your amp is probably slim, but it could happen... The same thing can happen with your headphones plugged into the LD, the headphone jack and the line out RCA's are connected to exactly the same spot inside the amp.

 IMHO, connecting a non OTL tube preamp to your system would be a much safer choice.


----------



## TontoGoldstein

trolldragon said:


> Your RMX 1450 is DC coupled, but it is supposed to have protection according to the QSC website.
> 
> 
> DC coupling won't make it sound good or bad either way. The problem with DC coupled amp hooked to the LD is if you encounter a catastrophic failure on one of the output tubes, the LD can  send 150V+ out the RCA jacks and into your amplifier. This will take out the complete amplifier and your speakers in a split second. The warning is put in the manual surrounded by a box for a reason, not to be taken lightly by any means.


 
 I appreciate you looking into my amp. However, like drones delivering my online purchases, this sounds like a far fetched scenario and it's never gonna happen. Besides, I've finally discovered good sound so it's worth the risk.


----------



## Brumas7

Thanks @TrollDragon for your reply. I have sent an email at the NAD site inquiring if both the NAD amps 356BEE and 320BEE are DC coupled and if an OTL amp could be used as pre-amp with them. Will report back when receive any updates from them.
 As an upgrade from my LD Mk3 I am thinking of ordering the Mk9 which is non-OTL.


----------



## Whelkie D

Thanks,@Brumas7 looking forward to their reply. If, and when you do decide to hook up your LD to your NAD I would recommend putting in a couple of in-line attenuators. Without these my LD through the NAD was just TOO LOUD! I couldn't get the volume dial on the LD past the "7 o'clock" mark which meant that there was a slight channel imbalance at that level. With the attenuators I can set the volume comfortably at around the "12 o'clock" mark which sounds pretty good.


----------



## Flex2d

ok figured out the sender sent the wrong ones.. glad i didn't try them..


----------



## Flex2d

Guys just wondering if i need to get a DAC to accompany the LD MK2.. I am however running a new Motherboard MSI ACK9 x99 .. think its got quiet good audio but not sure if it will do the LD MK2 justice. I running the LDMK" on the 1770 pro 250ohm head phone
  
 Any advice welcome for a newbie!
  
 Thanks


----------



## Johnnysound

trolldragon said:


> You guys would have to contact NAD and see if your amps are DC or not. The chance of the LD failing so that it would take out your amp is probably slim, but it could happen... The same thing can happen with your headphones plugged into the LD, the headphone jack and the line out RCA's are connected to exactly the same spot inside the amp.
> 
> 
> IMHO, connecting a non OTL tube preamp to your system would be a much safer choice




Hi TrollDragon, interesting topic, since I use my modded MKIII (C3Gs, ext power supply and 6AS7Gs) to drive a pair of NAD 2400 PE power amps in mono. 20 years plus old, not the latest model as the NAD BEE integrateds owned by several people here. I don't know where to begin,I have posted this before in this very forum, but just to sum up, IMHO the OTL preamp is a marriage made in heaven with the NAD amps.

I mean my NAD amps. They have what they called "power envelope", a propietary circuit that increases dynamic output in milliseconds, in response to signals, to 2X or even 3 or 4X the RMS output. My amps are a mild 120 W/channel RMS, 240 watts in mono, but reach nearly 500 watts in peaks !!. Marketing hype ? I thought so, until they blew a pair of big speakers, first the tweeters on one, then tweets & mids on another, bypassing protection and fuses...the peak was too fast. Only then I learned to respect those really powerful and outright dangerous amps. And that was with a solid state preamp, nothing compared with the OTL, which is way more powerful. 

Thankfully, the amps have a level control, so 1/4 power is now my absolute limit. The OTL is the very best sounding preamp with the NADs, by miles and miles, and not only that, every single tube rolled in the last 4 years revealed himself, with virtues and defects. I have no technical explanation. These are vintage SS amps, nearly top of the line at the time, with a very neutral sound, but they just come alive with the OTL, and never sounded better. And I do not mean only great highs and lows, I mean space, air, and a 3D rendition I never heard before with these amps. The tubes, of course, and the OTL...maybe the high voltage, or the inmediate, dynamic signal of this type of preamp is the reason why, I dont know.

Anyway, forget about any limiting devices. I really believe the new NADs have the same feature with another name, the same house sound, and yes, the OTL will be very loud. You have to limit the output of the power amp, assuming you have, first, a separate PA section, and second, a way to control the PA output. If you don't have this one, then we are entering dangerous waters...but believe me, great sound is worth the risks.

Cheers,

Johnnysound


----------



## Johnnysound

flex2d said:


> Guys just wondering if i need to get a DAC to accompany the LD MK2.. I am however running a new Motherboard MSI ACK9 x99 .. think its got quiet good audio but not sure if it will do the LD MK2 justice. I running the LDMK" on the 1770 pro 250ohm head phone
> 
> Any advice welcome for a newbie!
> 
> ...




Hi Flex2D, I was out of this site for some months, and now I am posting one after another !!

Let me say that I was also a newbie some years ago, and learned everything about the great LD gear and tubes in general, thanks to the experts here, which I am not of course. But know a few things about DACs, and the answer to your question is absolutely yes ! You do need an external DAC to really appreciate the sound potential of your MKII. On the other hand, you have a very nice MSI MB, and a brief look showed me that it has a separate audio spdif/optical output. This is great, since DACs work natively with spdif digital, not with USB, and the USB converters in many DACs are a weak link. There are many good DACs, at every price point, but keep in mind that you already have a very nice tube preamp, and it will not hide anything, so you can't feed it with any DAC. You need a good one, and make sure that it has an optical input. Please let me know your choices, maybe I can help with this. Cheers,


----------



## Flex2d

Thanks for the reply!
  
 I was looking at this one
 SMSL M3 or M6 version..
 £120 is max budget tbh for the DAC
  
 whats your thoughts?
  
 Thanks
  
 Daniel


----------



## TrollDragon

johnnysound said:


> Hi TrollDragon, interesting topic, since I use my modded MKIII (C3Gs, ext power supply and 6AS7Gs) to drive a pair of NAD 2400 PE power amps in mono. 20 years plus old, not the latest model as the NAD BEE integrateds owned by several people here. I don't know where to begin,I have posted this before in this very forum, but just to sum up, IMHO the OTL preamp is a marriage made in heaven with the NAD amps.
> 
> I mean my NAD amps. They have what they called "power envelope", a propietary circuit that increases dynamic output in milliseconds, in response to signals, to 2X or even 3 or 4X the RMS output. My amps are a mild 120 W/channel RMS, 240 watts in mono, but reach nearly 500 watts in peaks !!. Marketing hype ? I thought so, until they blew a pair of big speakers, first the tweeters on one, then tweets & mids on another, bypassing protection and fuses...the peak was too fast. Only then I learned to respect those really powerful and outright dangerous amps. And that was with a solid state preamp, nothing compared with the OTL, which is way more powerful.
> 
> ...


 
 Hey Johnnysound!

 Congrats! It sounds like you have found an excellent configuration for your LD and mono blocks! 

 I only post about the LD as a preamp issue to warn new owners there is the possibility of it taking out their system. A shorted tube from a shady eBay seller and you've blown your system or your headphones if you are not using the LD as a preamp. I always use a pair of cheap junk headphones to test any new tubes that arrive from eBay.


----------



## Flex2d

So you shouldn't trust ebay tubes?..
 Just been buying some in anticipation of my LD MK2 arriving in the next week or so..
  
 So I should test them with crappy cans before using 1770 pro's?
  
  
 Best
  
 Daniel


----------



## Flex2d

If thats the case i have blown about £100 down the ebay drain.. can you recommend where I can find a good supplier of tubes in the UK?
  
 Cheers
  
 Daniel


----------



## Whelkie D

So far I've bought about 4 pairs of tubes off Ebay. All OK. Just check feedback for ratings from other tube-buyers!


----------



## gibosi

flex2d said:


> So you shouldn't trust ebay tubes?..
> Just been buying some in anticipation of my LD MK2 arriving in the next week or so..
> 
> So I should test them with crappy cans before using 1770 pro's?


 
  
 I have something like 1500 tubes, most of them purchased on eBay. Yes, of course, there are dishonest sellers, but the vast majority of sellers are good and decent people. To date, I have bought from only two dishonest sellers. And in both cases, I asked eBay to step in and received a full refund, including shipping.
  
 But it is important to remember that tube testing equipment is not all that reliable. I have received a number of tubes that tested fine in tube testers, but didn't work in my amp. That is, the only way to really test a tube is to put it in a working circuit. And since most sellers are good people, in almost every case, they were willing to make things right.
  
 Like Whelkie D, I check the information in the Seller's Information box. I prefer to deal with sellers who have a good feedback score and have sold at least several hundred items.


----------



## Oskari

flex2d said:


> So you shouldn't trust ebay tubes?..
> Just been buying some in anticipation of my LD MK2 arriving in the next week or so..
> 
> So I should test them with crappy cans before using 1770 pro's?




There's no reason to panic but that's always a good idea.




flex2d said:


> If thats the case i have blown about £100 down the ebay drain.. can you recommend where I can find a good supplier of tubes in the UK?




Still no reason to panic. 

There's Langrex, for example, known as yitry on ebay.



 http://www.langrex.co.uk/


----------



## djgriff

What are considered the best overall tubes?
 for LD MK2


----------



## TrollDragon

djgriff said:


> What are considered the best overall tubes?
> for LD MK2


 

 There are no "best" tubes... The tubes that Johnnysound uses in his MK3 are considered by most as endgame tubes for the LD  MK2/3/4 series.

 A pair of C3g's for the preamp tubes and a pair of 6AS7G's as output tubes are considered the best setup you can use. The C3g's require socket adapters and the 6AS7G's require a modified socket adapter with an external power supply for the heater current.


----------



## Doge91

I've been using my MK III for over a month now and didn't have any problems (apart from initial ground loop that I managed to fix easily by using a power extension cord that doesn't have ground pins). But recently the amp has developed a humming problem. It hums at very low frequencies for about 2 seconds, then 2 seconds of silence, then it repeats the cycle infinitely. It's a quiet humminh and I don't notice it when I listen to music, but when there's no music it's very irritating. Do I need to replace the power tubes?


----------



## TrollDragon

doge91 said:


> I've been using my MK III for over a month now and didn't have any problems (apart from initial ground loop that I managed to fix easily by using a power extension cord that doesn't have ground pins). But recently the amp has developed a humming problem. It hums at very low frequencies for about 2 seconds, then 2 seconds of silence, then it repeats the cycle infinitely. It's a quiet humminh and I don't notice it when I listen to music, but when there's no music it's very irritating. Do I need to replace the power tubes?


 

 Does not sound like a tube problem to me.
 It sounds like electrical interference on your lines or something running on the same circuit. Disabling the AC ground introduces all kinds of opportunity for random electrical noise. Try plugging the MK3 in to a different outlet (different part of your house) to see if the noise continues. If it does then take it to work one day or to a friends house to see if the noise continues.

 You need to figure out if it is the AC power, the amp or another component.


----------



## Flex2d

cool


----------



## Flex2d

​Following on from this is there a *best* tube that doesn't require modification? .. i'm guessing the Mullard 8100 are quite good.
 does any one have or recommend these 6H30-EB-GOLD-ELECTRO HARMONIX?
Do they match up to the Russian power tubes?
  
​Thanks


----------



## Flex2d

Forgive me for asking but i am super newbie to valves.. How do I know what type will work with LD MK2 ?
 There seems to be so many different types.
  
 Thanks


----------



## Whelkie D

Yes, the Mullard 8100 are very good - very "warm" sounding. The bass can sometimes seem a little "muddy" with these. Having said that, mine probably haven't burnt-in properly yet. Also the Voskhod 6ZH1P are really nice and crisp sounding. And the GE Jan 565t4W are good (again mine have not had time to burn in yet - so many tubes, so little time!) All are EF95 family, so you should'nt have to change the default settings on the LD MK2. I'm running these with the Russian 6N6P power tubes with no problems.


----------



## Flex2d

Lol i just can't wait to get started 
 I'll look to get a pair of these GE Jan 565t4​ as suggested.. Got the other 2  all in preparation for the arrival of the LD mk2 lol


----------



## TrollDragon

flex2d said:


> ​Following on from this is there a *best* tube that doesn't require modification? .. i'm guessing the Mullard 8100 are quite good.
> does any one have or recommend these 6H30-EB-GOLD-ELECTRO HARMONIX?
> Do they match up to the Russian power tubes?
> 
> ​Thanks


 
 The tall version Yugoslavian 6HM5 are considered by many in this thread to be one of the best sounding, inexpensive plug and play tubes. After that you start getting into modified adapters and possible external power supplies.

 Cheap to try, get three in case one breaks in transit.
 http://www.ebay.com/itm/6HM5-6HA5-EC900-export-quality-audio-triode-tube-NOS-FREE-SHIPPING-/300879467071

 The output tubes have a lesser impact on sound but you can try the 6N6P-IR's they are quite popular and well regarded here.
 http://www.ebay.com/sch/i.html?_from=R40&_sacat=0&_nkw=6n6p-ir&_sop=15


----------



## TrollDragon

flex2d said:


> Lol i just can't wait to get started
> I'll look to get a pair of these GE Jan 565t4​ as suggested.. Got the other 2  all in preparation for the arrival of the LD mk2 lol


 
 It's a rabbit hole... I have a case full of tubes that I don't even use anymore as I have found other tubes that I like much better. A lot of fun checking out cheap tubes, once you start paying more than $10 for them, the unused tubes can turn into costly dust catchers really quickly.

 They are not Pokemon you don't gotta Catch Em All...  
	

	
	
		
		

		
			





 I have *nothing* compared to some on this thread...


----------



## TrollDragon

flex2d said:


> Forgive me for asking but i am super newbie to valves.. How do I know what type will work with LD MK2 ?
> There seems to be so many different types.
> 
> Thanks


 

 Back in the day, the chart in this post was our bible of replacement type tubes and how to strap them or use them directly.

 Many of the tubes in this list are still viable and are all quite inexpensive.
 http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/1140#post_9392055


----------



## Flex2d

​Wow , thanks for the info and nice pics.. yeah can't wait for next pay check  and get the ones mentioned. fingers crossed the amp should arrive this week.
 Cheers
  
 Daniel


----------



## frogmeat69

trolldragon said:


> It's a rabbit hole... I have a case full of tubes that I don't even use anymore as I have found other tubes that I like much better. A lot of fun checking out cheap tubes, once you start paying more than $10 for them, the unused tubes can turn into costly dust catchers really quickly.
> 
> They are not Pokemon you don't gotta Catch Em All...
> 
> ...


 

 Lol, reminds me of..... me. At least yours are nicely stored, mine are in a beat up cardboard box! I fell down the rabbit hole hard with this hobby, tubes, headphones and  amps everywhere.


----------



## Share2Care

flex2d said:


> Lol i just can't wait to get started
> 
> I'll look to get a pair of these GE Jan 565t4​ as suggested.. Got the other 2  all in preparation for the arrival of the LD mk2 lol




I have been looking at ways of storing my tubes and you Sir have found a damn good solution! Would you be so kind to let me know where you sourced it from? Is it a foam small inserts you pull out to get the right fit? 

If Ebay, I am based in the UK but would hope available here! 

Tip top and thank you for your help!


----------



## djgriff

Hi, yeah it is small cubes you either pull away or cut with scissors. I purchased the case on amazon and you can find it here: case
  
 https://www.amazon.co.uk/gp/product/B00BM3RCOQ/ref=oh_aui_detailpage_o01_s00?ie=UTF8&psc=1
  
 works a treat, i also make a note on card and slot inbetween the cubes if i forget which is which.
  
 Best 
  
 Daniel


----------



## djgriff

Please excuse me din't realise i had a different account on my mac to my pc!!


----------



## i luvmusic 2

trolldragon said:


> flex2d said:
> 
> 
> > Forgive me for asking but i am super newbie to valves.. How do I know what type will work with LD MK2 ?
> ...


 
 YUP those were the days i've learned a lot from you guys in this thread i miss those days,Thanks!


----------



## i luvmusic 2

flex2d said:


> Lol i just can't wait to get started
> I'll look to get a pair of these GE Jan 565t4​ as suggested.. Got the other 2  all in preparation for the arrival of the LD mk2 lol


 
 Nice tube box mine is in the shoe box.


----------



## TrollDragon

i luvmusic 2 said:


> YUP those were the days i've learned a lot from you guys in this thread i miss those days,Thanks!


 
 Those were indeed great days ILM2!
 Many thread pages per day, it was hard to keep up sometimes.


----------



## i luvmusic 2

I guess most of us move on but for me still learning from this hobby (Tube gears).
 My MK III is being used as a Preamp for my set-up haven't listen to it with headphones for awhile.


----------



## i luvmusic 2

BTW around April or May i'am planning to build a tube amp base on the tubes that i have maybe you could guide me(TD).


----------



## gibosi

i luvmusic 2 said:


> I guess most of us move on but for me still learning from this hobby (Tube gears).
> My MK III is being used as a Preamp for my set-up haven't listen to it with headphones for awhile.


 
  
 Yes, indeed, those were great days, scouring eBay for new tubes and then trying to figure out how to run them in our Little Dots.
  
 And for me, even though I now have a very different amp, nothing has really changed. That is, I am still scouring eBay for new tubes and then trying to figure out how to rum them. For example, pictured below, using four 6BX7 in place of two 6AS7, one ECC31, a common cathode double triode, in place of a 6SN7, and one UU8, a 4-volt rectifier, in place of a 5U4G.
  
 And I am having a blast!


----------



## gulakpi

trolldragon said:


> Those were indeed great days ILM2!
> Many thread pages per day, it was hard to keep up sometimes.


 
 Those were great days indeed!
 I've been longing to read the new threads every day!
 I've learned a lot from you folks and still enjoying my LD, though I've a few other headphone amps.


----------



## gulakpi

doge91 said:


> I've been using my MK III for over a month now and didn't have any problems (apart from initial ground loop that I managed to fix easily by using a power extension cord that doesn't have ground pins). But recently the amp has developed a humming problem. It hums at very low frequencies for about 2 seconds, then 2 seconds of silence, then it repeats the cycle infinitely. It's a quiet humminh and I don't notice it when I listen to music, but when there's no music it's very irritating. Do I need to replace the power tubes?


 
  
  
  
 Any chance that the LD is located near a router or other WIFI card, or microwave oven etc.?
 The vacuum tube preamps are quite susceptible to induced noises, especially you are using a floating (ungrounded) power cable!


----------



## Whelkie D

Not sure if this has been discussed on here already but, do damper rings on tubes make a difference to SQ or are they just a gimmick to prise more money from our shrinking wallets?


----------



## TrollDragon

whelkie d said:


> Not sure if this has been discussed on here already but, do damper rings on tubes make a difference to SQ or are they just a gimmick to prise more money from our shrinking wallets?


 

 They look really neat and add the same performance as chrome (go faster) tail lights.


----------



## Whelkie D

Great - will order a crate load immediately.


----------



## i luvmusic 2

gibosi said:


> i luvmusic 2 said:
> 
> 
> > I guess most of us move on but for me still learning from this hobby (Tube gears).
> ...


 
  WOW!That's a lot of tubes on  amp it looks good  i'am  sure it sounds good as will.I only listen to headphone occasionally currently i'am listening to my PIONEER SA-7700, SANSUI SPX-6900 Technics SL-1700(Shure M97xe/Ortofon 2M Red),LD MK III,KENWOOD KM 992,BOSE 901 Series I my setup is not a higher end vintage gear but i can tell you it sound much better than my Headphones.


----------



## Share2Care

Aloha Amigos! 

I have upgraded to a MK2 Little Dot which has the delight of power tubes and driving tubes. Someone on Ebay is siggesting a 30 year old matched pair of power tubes but they are very expensive and not sure a MKII would really get a benefit? 

So I can bond (lol) with my MK2, I would really appreciate 3 types of power tubes and 3 types of driving tubes. I am looking to get some hearing as to the differences between the tubes as the tubes burn in and also the MK2. 

I do not mind spending big bucks for a matched pair, so long as the on route Little Dot MK2 will reveal what the tubes has to offer? I take it that matched is is advised? 

Thank you as ever for your help and the 3 driving pairs and 3 power pairs with a link would be whole heartedly appreciated. I am in the UK so local is preferable but not a barrier! 

Excited!


----------



## Whelkie D

share2care said:


> Aloha Amigos!
> 
> I have upgraded to a MK2 Little Dot which has the delight of power tubes and driving tubes. Someone on Ebay is siggesting a 30 year old matched pair of power tubes but they are very expensive and not sure a MKII would really get a benefit?
> 
> ...


 
 I have a apir of these power tubes..........................................http://www.ebay.co.uk/itm/252104424414?_trksid=p2060353.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT
  
 Driver tube links...................................
  
 http://www.ebay.co.uk/itm/111919574030?_trksid=p2060353.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT
  
 http://www.ebay.co.uk/itm/380926712989?_trksid=p2060353.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT
  
 http://www.ebay.co.uk/itm/2x-Voshkod-6ZH1P-EV-6J1P-EV-Matched-Pair-Little-Dot-Amp-III-IV-/142138665883?hash=item21181feb9b:g:bfYAAOSwUKxYkHgt (these come from Latvia but mine only took 4 days to arrive - I'm in UK also)


----------



## MIKELAP

share2care said:


> Aloha Amigos!
> 
> I have upgraded to a MK2 Little Dot which has the delight of power tubes and driving tubes. Someone on Ebay is siggesting a 30 year old matched pair of power tubes but they are very expensive and not sure a MKII would really get a benefit?
> 
> ...


 
 For your information its a well known fact that tubes dont need to be matched for these amps Here's a power tube review on page 201post 3007


----------



## Brumas7

whelkie d said:


> Thanks,@Brumas7 looking forward to their reply. If, and when you do decide to hook up your LD to your NAD I would recommend putting in a couple of in-line attenuators. Without these my LD through the NAD was just TOO LOUD! I couldn't get the volume dial on the LD past the "7 o'clock" mark which meant that there was a slight channel imbalance at that level. With the attenuators I can set the volume comfortably at around the "12 o'clock" mark which sounds pretty good.


 
 Hi @Whelkie D -- NAD replied and said that both our NAD amps are not DC-coupled. Instead they are AC-Coupled. So that means we could now be at peace when using LD Mk3 as pre-amp for those NAD amps .
 Thanks for the tips about using in-line attenuators.


----------



## Whelkie D

Thanks for that @Brumas7 - really good to have that confirmed. Let me know how you get on once you have the LD hooked up to your amp.


----------



## Brumas7

Most welcome. My speakers setup is not having too much attention these days while I pay more attention to headphones and tubes amps. Sure if/when I get round to hooking my LD to NAD amp, will alert you. I have not used any in-line attenuators presently. I checked online and it seems Rothwell is popular and I would need a pair with RCA connectors. I will probably check if I could find cheaper alternatives at audio stores locally or I would order on-line. Johnnysound had shared his positive experience pairing LD and his NAD amps, it is worth a try.


----------



## Share2Care

whelkie d said:


> I have a apir of these power tubes..........................................http://www.ebay.co.uk/itm/252104424414?_trksid=p2060353.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT
> 
> Driver tube links...................................
> 
> ...




Thank you very much indeed for taking the time to select out some tubes for me to purchase. I still have my MK1 as well. If you ever have some tubes you believe would be great to hear, feel free to PM me as I woukd be happy to pay! 

For anyone that can help someone at the start of their tybe rolling journey I would like to say thank you. We all have to start from the beginning. It is fantastic that there is this resource for us. 

I am also tempted by getting a Darkvoice. Any thoughts on that?


----------



## MIKELAP

share2care said:


> whelkie d said:
> 
> 
> > I have a apir of these power tubes..........................................http://www.ebay.co.uk/itm/252104424414?_trksid=p2060353.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT
> ...


 
 Next logical step is a tube amp using 6AS7 and 6SN7 type tubes if your ready to invest about $900.00US and depending also on where you live (duty's and taxes) i would suggest the ELISE by Feliks Audio its made in Poland and from the same company the newly released Euforia which is an upgraded Elise very good reviews on this amp here'a link http://feliksaudio.pl/en/products.php


----------



## Share2Care

mikelap said:


> Next logical step is a tube amp using 6AS7 and 6SN7 type tubes if your ready to invest about $900.00US and depending also on where you live (duty's and taxes) i would suggest the ELISE by Feliks Audio its made in Poland and from the same company the newly released Euforia which is an upgraded Elise very good reviews on this amp here'a link http://feliksaudio.pl/en/products.php




Hi There!

This is a great recommendation for me as based in the UK, getting hammered by import customs is starting to hurt whereas they are based in the EU, which we are for about another 25 months! Lets not get into that. 

Any chance of more personal information on them? I have been on their website and they do offer ehat seems to be high quality different amp finishes and tubes from as you say, $900 USD onwards. 

I would prefer to save for a little longer to possibly skip the DarkVoice. 

Thanks for the help. Appreciated


----------



## MIKELAP

share2care said:


> mikelap said:
> 
> 
> > Next logical step is a tube amp using 6AS7 and 6SN7 type tubes if your ready to invest about $900.00US and depending also on where you live (duty's and taxes) i would suggest the ELISE by Feliks Audio its made in Poland and from the same company the newly released Euforia which is an upgraded Elise very good reviews on this amp here'a link http://feliksaudio.pl/en/products.php
> ...


 
 There are several threads on the Elise amp and the new Euforia this is current Elise thread http://www.head-fi.org/t/813488/feliks-audio-elise-impressions-thread-a-new-start-please-read-first-post-for-summary/6105#post_13244256 The  older Elise thread  lots of tube rolling ideas     http://www.head-fi.org/t/782754/feliks-audio-elise-new-thread/13290#post_13223481


----------



## MIKELAP

mikelap said:


> share2care said:
> 
> 
> > mikelap said:
> ...


 
 I might ad that they are a family business i dont have the Elise myself but know several hedfiers that do and they only have good things to say about  it and by the way for 2017 the Elise was updated and it has a 3 year warranty i guess you have some reading to do lol .Have fun . This is the Euforia thread only a couple guys have this amp so far http://www.head-fi.org/t/831743/feliks-audio-euforia-a-wolf-in-sheeps-clothing/840#post_13247807


----------



## rudra

May I suggest a LD MKV1+ which will allow you to roll your existing 6AS7 and 6SN7 tubes. I went from a DV 336SE to the MKVI+. Best upgrade.


----------



## Johnnysound

flex2d said:


> Thanks for the reply!
> 
> I was looking at this one
> SMSL M3 or M6 version..
> ...




Hi Daniel, after a brief check on the net, go for the M6 !. Nice reviews, a very good AKM processor, and most important, asynchronous operation which means that the DAC takes control of your computer audio output, a great feature for sound quality. The M6 has a nice USB input, but also an optical SPDIF one, and your MSI computer have a direct link. All you need here is a good fiber optic cable to the DAC, and you are set.

I have no personal experience with this particular brand, but their M8 top of the line DAC features the latest Sabre 9 series D/A converters, and got great reviews from specialists. What convinced me is the SMSL Audio T1, a tubed DAC that impressed some reviewers and costs $ 350. Cheap for a tubed DAC. Anyway, the message here is that SMSL DACs are really good...


----------



## Flex2d

johnnysound said:


> Hi Daniel, after a brief check on the net, go for the M6 !. Nice reviews, a very good AKM processor, and most important, asynchronous operation which means that the DAC takes control of your computer audio output, a great feature for sound quality. The M6 has a nice USB input, but also an optical SPDIF one, and your MSI computer have a direct link. All you need here is a good fiber optic cable to the DAC, and you are set.
> 
> I have no personal experience with this particular brand, but their M8 top of the line DAC features the latest Sabre 9 series D/A converters, and got great reviews from specialists. What convinced me is the SMSL Audio T1, a tubed DAC that impressed some reviewers and costs $ 350. Cheap for a tubed DAC. Anyway, the message here is that SMSL DACs are really good...


 

 ​Thanks for the advice Jonnysound, yeah it looks pretty cool however could you recommend any other brands to consider for a good DAC.
  
 Oh just got my LD mk2 on Thursday - Woohoo! I swapped out the valves for Mullard m8100 and some Russian 6n6p gold grid. The sounds really nice and spacious just the way I like it but feel the mids are lack detail and warmth.
  
 do you think this is something that will mature over time or could you recommend a very similar tube with a little more depth in the middle without muddling the clarity and spaciousness
  
  
  
 Many Thanks
  
 Daniel


----------



## Flex2d

Guys quick question: I am amazed at the sound coming from my LD mk2 with m8100 and Russian tubes.. if I was to take this further as in a £500 tube amp would I see a vast improvement in the sound?
  
 Thanks
  
 Daniel


----------



## Whelkie D

Has anyone had any experience with the Raytheon 5654 6AK5W tubes in a LD MK2? How do they compare to the Mullard 8100s or Voskhods? Do they need a long burn-in? Any info would be greatly appreciated.


----------



## Flex2d

Hey Guys/Gals,
  
 I have noticed that the version of LD mk2 does not match up to the manual.
  
 It states that the board will not have jumpers as standard but mine has jumpers in.
 Also there are 3 pins not 2 .
  
 So I am confused as to how I can switch the mode to EF92.
  
 Should I remove the jumpers or move the jumper to the centre other one.
  
 not really sure what to do.
  
 Also I am running EF85 M8100 tubes currently with the jumpers in
  
 If anyone know would be cool or at least some help
  
 the board state v.3
  
 Thanks
  
 Daniel


----------



## MIKELAP

flex2d said:


> Hey Guys/Gals,
> 
> I have noticed that the version of LD mk2 does not match up to the manual.
> 
> ...


 

  
 Does it look like in the picture if so when using EF92 tubes you use the 2 pins furthest  to the left if EF95 2 pins furthest to the right


----------



## MIKELAP

mikelap said:


> flex2d said:
> 
> 
> > Hey Guys/Gals,
> ...


 
 Another thing since your board is version v.3 you can use 6H30PI power tubes in case you didnt know


----------



## Flex2d

​Yes, Perfect thank you!
  
 lol if you visit the domain printed on the board you go to a dating site.. not sure that is intended but a funny quirk
  
 Best
  
 Daniel


----------



## Whelkie D

flex2d said:


> Hey Guys/Gals,
> 
> I have noticed that the version of LD mk2 does not match up to the manual.
> 
> ...


 
 My LD MK2 also has 3 jumper pins. Here's what the Little Dot MK11 guide says;
  
 "2-pin sets: If the jumper caps are removed, you can use the 5654/6JI driver tubes (default). If the jumper
 caps are placed over the pins, you can use EF92 type driver tubes.

 3-pin sets: Place the jumper cap over the middle pin and the pin to the side of the “E95” text to use the
 default 6JI/5654 tubes. Place the jumper cap over the middle pin and the pin to the side of the E92 text to
 use EF92 type tubes."
 Hope this is useful. I haven't tried changing the jumper pins yet so would be curious to see how you get on with swapping them!


----------



## Flex2d

​Hi WhelkieD,
  
 Switched the jumpers and all good. plugged in some M8161/EF92/6065/CV4015 MULLARD NOS​ and they pretty darn good if I must say so. Slight more fuller maybe slightly less on the spaciousness in the sound maybe not quiet the same instrument isolation as the M8100, but having said this I have to burn them both in for 60hrs I think is the mark to aim for.
  
 otherwise all working good!
  
 Thanks
  
 Daniel


----------



## Flex2d

​Aah ok didn't realise I could use different power tube! are they better than the 6n6 power tubes or do you have a recommendation on a power tube I could try?
  
 Is there any settgins/switchs to use the new power tubes?
  
 Thanks
  
 Daniel


----------



## Flex2d

Just a thought.. Has anyone tried modifying the case of the LD mk2? i.e drill some air vent holes.. it does get kinda hot.. thinking this would help with the thermals.
  
 Anyone investigated this?
  
 Thanks
  
 Daniel


----------



## Whelkie D

AAAArgh!! Turned on my LD MK2 today and the left channel is DEAD!. No signal in either headphones or pre amp on left side. Have changed tubes and cables etc but still only getting the right channel coming through. I've only had it 5 weeks and have emailed the place I bought it from but while I'm waiting to hear from them, is there anything that I may have overlooked?  Feeling gutted.


----------



## Flex2d

shoot dude that sucks!! is it a v3 board?
  
 best
  
 Daneil


----------



## Whelkie D

Not sure. How can I tell?


----------



## MIKELAP

whelkie d said:


> AAAArgh!! Turned on my LD MK2 today and the left channel is DEAD!. No signal in either headphones or pre amp on left side. Have changed tubes and cables etc but still only getting the right channel coming through. I've only had it 5 weeks and have emailed the place I bought it from but while I'm waiting to hear from them, is there anything that I may have overlooked?  Feeling gutted.


 
 That happened to me once in my MK3 it ended up being a bad solder joint in the pot, the wire had broken off.


----------



## feinanng

Looking for tube rolling on MK2.
 Which tubes sounds good on hd650? I am looking for warm sounding and bright to get rid of the Sennheiser 'Veil'.
 Thanks


----------



## OctavianH

feinanng said:


> Looking for tube rolling on MK2.
> Which tubes sounds good on hd650? I am looking for warm sounding and bright to get rid of the Sennheiser 'Veil'.
> Thanks


 
 In my opinion you cannot get rid of the "veil" but for sure obtain a more detailed and neutral sound with EF92 M8161 (Mullard). These are used in my current setup and sound good with HD600 and T1. I previously owned HD650 and I think they are close to HD600, but more bassy. Try M8161 and you will be fine.


----------



## gulakpi

feinanng said:


> Looking for tube rolling on MK2.
> Which tubes sounds good on hd650? I am looking for warm sounding and bright to get rid of the Sennheiser 'Veil'.
> Thanks


 
 Undoubtedly, the C3g, as recommended by some other good guys in this post!   
 I'm using the C3g with my HD650.    I tried quite a number of different tubes before.  The C3g has the detail, clarity as well as clean bass I need.


----------



## feinanng

octavianh said:


> In my opinion you cannot get rid of the "veil" but for sure obtain a more detailed and neutral sound with EF92 M8161 (Mullard). These are used in my current setup and sound good with HD600 and T1. I previously owned HD650 and I think they are close to HD600, but more bassy. Try M8161 and you will be fine.


 
  
  


gulakpi said:


> Undoubtedly, the C3g, as recommended by some other good guys in this post!
> I'm using the C3g with my HD650.    I tried quite a number of different tubes before.  The C3g has the detail, clarity as well as clean bass I need.


 
 Thanks! I just ordered M8161 for MK2. Will definitely try C3g later!
  
 Do I need swap out the stock Power Tube as well?


----------



## OctavianH

No, but I advise you to do it because as far as I know they have an impact on bass precision. I changed them with 6N6P NEVS.


----------



## dobigstuff

feinanng said:


> Looking for tube rolling on MK2.
> Which tubes sounds good on hd650? I am looking for warm sounding and bright to get rid of the Sennheiser 'Veil'.
> Thanks


 

 Feinanng:
  
 Just a suggestion.......I have a Little Dot MK III and HD 700's.  Try to upgrade your stock headphone cable (if you haven't already)  A good aftermarket cable sound than the stock cable.
 Again, some don't want to spend the additional money.  I have a Black Dragon v2 Cable, and for me, it cleared up my HD 700's.  Tight bass, clean Mids and not real bright highs.
 Good Luck.


----------



## TrollDragon

IMHO the LD MKIII would be better served with a C3g/6AS7G endgame tube combo with that money, instead of a $250 cable.
  
 Like everything in the game of audio, YMMV.


----------



## Scutey

feinanng said:


> Looking for tube rolling on MK2.
> Which tubes sounds good on hd650? I am looking for warm sounding and bright to get rid of the Sennheiser 'Veil'.
> Thanks


 

 ​The M8161  are very good, also try Voskhod 6zh1p-ev, another highly recommended tube is the EI 6hm5, they are cheap, but as others have said the c3g is the pinnacle for the LD but they are expensive and hard to get.


----------



## i luvmusic 2

Did someone said cable?This should do it however it may require a long BURN-IN time.....


----------



## Scutey




----------



## Typhoon859

feinanng said:


> Looking for tube rolling on MK2.
> Which tubes sounds good on hd650? I am looking for warm sounding and bright to get rid of the Sennheiser 'Veil'.
> Thanks


 
 I kind of expected you were going to get different answers, but to me, it almost sounds like you were directly describing the Voskhod 6ZH1P-EV.  I would recommend getting ones with the OTK1 and military diamond/rhombus stamp.  A seller I'd strongly recommend is Ebay user *glaz_25*.  It might take a while to ship but he has great quality tubes and provides excellent care of your order.  The only thing is, nothing can really help the "veil" on the 650's, even EQ, as it's less a veil as it is the higher frequencies just somehow squashed/suppressed.  That along with more bloated bass/lower mids and a more limited soundstage (due to the differences in the reproduction of the treble) is precisely why I prefer the HD 600's (which ironically has the opposite problem where even though smooth, the upper frequencies can get quite overbearing with extended listening).
  
*^If anyone is looking for Voskhod tubes, I would definitely recommend this seller.^*
  
 One seller I definitely wouldn't recommend is *Tubes Unlimited at nosvacuumtubes.net*, especially for the Voskhods.  *Do not buy from there!*  He sells some other brand, AEL, and were NOT manufactured at the Voskhod factory (claiming that they actually were), and is the most pretentious, arrogant, pointlessly prideful, know-nothing "business owner" - the biggest deluded nobody I've come across in a long time.  I'm the last person to typically label someone as arrogant, but if that person exists, it would definitely be him.  If there are any problems, he's the last person you'd want to deal with - just perhaps a warning for future buyers.


----------



## Typhoon859

I haven't tried the C3G.  Is this what everyone is talking about?  I've never seen one with an additional connector (or whatever it is) in the center.  How would it fit? XD


----------



## gibosi

typhoon859 said:


> I haven't tried the C3G.  Is this what everyone is talking about?  I've never seen one with an additional connector (or whatever it is) in the center.  How would it fit? XD


 
  
 The links are likely outdated by now, but this shows one way people are using the C3g:
  
 http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/6000#post_10512665


----------



## Typhoon859

gibosi said:


> The links are likely outdated by now, but this shows one way people are using the C3g:
> 
> http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/6000#post_10512665


 
 Oh, that's interesting.  I see.  Ok, so I'm not crazy then XD
  
 Lol, thanks for the clarification.


----------



## TrollDragon

typhoon859 said:


> *^If anyone is looking for Voshkod tubes, I would definitely recommend this seller.^*


 
 The pet peeve of this thread... 
	

	
	
		
		

		
		
	


	




_*Voskhod*_ is the correct spelling.


----------



## Typhoon859

trolldragon said:


> The pet peeve of this thread...
> 
> 
> 
> ...


 
 Ok, fixed.  Does it really matter though?  I linked directly to where you can find them so there wouldn't really be any confusion on that end.
  
 Also, ironically, I actually speak Russian, and I know what the word is supposed to sound like.  Neither spelling makes sense.  It's technically just supposed to be pronounced "vas-hoh'd".  No idea where the "k" comes from.


----------



## Oskari

typhoon859 said:


> Also, ironically, I actually speak Russian, and I know what the word is supposed to sound like.  Neither spelling makes sense.  It's technically just supposed to be pronounced "vas-hoh'd".  No idea where the "k" comes from.




The "k" is a clue for English speakers that the s and h should be separate; otherwise they'd see the "sh" as /ʃ/.


----------



## Typhoon859

oskari said:


> The "k" is a clue for English speakers that the s and h should be separate, otherwise they'd see the "sh" as /ʃ/.


 
 Right, but it just ends up changing it to a "k" sound.  You could just put a dash XD
  
 In any case, not the most relevant thing.  Don't want to fill the board up with this.


----------



## MIKELAP

trolldragon said:


> typhoon859 said:
> 
> 
> > *^If anyone is looking for Voshkod tubes, I would definitely recommend this seller.^*
> ...


 
            Sorry couldnt resist.


----------



## OctavianH

gibosi said:


> The links are likely outdated by now, but this shows one way people are using the C3g:
> 
> http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/6000#post_10512665


 
 Ok but where we can find the adaptors and so on, to be able to use these on MK2? I would be interested to buy as a kit (not sure what to buy separately to adapt them).
  
 LATER EDIT:
 It seems there are some direct adapters for c3g to 6AK5 here which seem to work for MK2/3:
  
 http://www.ebay.com/itm/1pc-C3G-TO-6AK5-5654-6096-6J1-Tube-adapter-for-little-dot-MKIII-SE-Headphone-/201330219735?hash=item2ee0375ad7:g:ZHcAAOSw9N1VwVKM


----------



## gibosi

octavianh said:


> Ok but where we can find the adaptors and so on, to be able to use these on MK2? I would be interested to buy as a kit (not sure what to buy separately to adapt them).
> 
> LATER EDIT:
> It seems there are some direct adapters for c3g to 6AK5 here which seem to work for MK2/3:
> ...


 
  
 Yes, these adapters will work with LD1+, II, III and IV.
  
 And if you don't want to remove the gold rings, the spacers from Leeds Radio are still available. So while there isn't an actual "kit" out there, if you buy the tubes, the adapters and the spacers, you are good to go.


----------



## OctavianH

Good to know and very interesting, but compared to Mullard 8161 how is the sound improved? Or at least judging by the 5 cryterias used in this thread (bass/mid/treble/detail/soundstage)? Because "they sound great" does not say anything to me.
 I replaced my Voskhods because M8161 had better detail (clarity) on cymbals and seemed for me a better choice. Now, since I do not have the chance to try them, I would like to know what will be better on c3g compared to my current setup before spending 200$ on it (except 10000h which is already a huge improvement).


----------



## gibosi

octavianh said:


> Good to know and very interesting, but compared to Mullard 8161 how is the sound improved? Or at least judging by the 5 cryterias used in this thread (bass/mid/treble/detail/soundstage)? Because "they sound great" does not say anything to me.
> I replaced my Voskhods because M8161 had better detail (clarity) on cymbals and seemed for me a better choice. Now, since I do not have the chance to try them, I would like to know what will be better on c3g compared to my current setup before spending 200$ on it (except 10000h which is already a huge improvement).


 
  
 In a nutshell, when pentodes are strapped as triodes, linearity typically goes out the window and distortion increases. And this is the model used in a Little Dot. That is, a pair of 6AK5, pentodes, are strapped as triodes.
  
 The C3g, also a pentode, is unique in that it was deliberately designed to be strapped as a triode, with linearity and distortion levels comparable to a 6SN7, one of the finest tubes available for use in vacuum tube audio.
  
 As an aside, one of the reasons the 6HM5 and the 6AV6 sound as good as they do, is that they are not triode-strapped pentodes. They are true triodes, with better linearity and lower distortion than any 6AK5.
  
 So, the sonic signature of pair of C3g is comparable in linearity and distortion to a 6DJ8, used in a number of Schiit products, or a 6SN7, used in countless other audio products.
  
 But of course, YMMV. There is no guarantee that they will sound better to your ears.


----------



## Scutey

Quote: 





octavianh said:


> Good to know and very interesting, but compared to Mullard 8161 how is the sound improved? Or at least judging by the 5 cryterias used in this thread (bass/mid/treble/detail/soundstage)? Because "they sound great" does not say anything to me.
> I replaced my Voskhods because M8161 had better detail (clarity) on cymbals and seemed for me a better choice. Now, since I do not have the chance to try them, I would like to know what will be better on c3g compared to my current setup before spending 200$ on it (except 10000h which is already a huge improvement).


 

 ​Ok, I've been using the C3G in my LD MKIII for two months now so I will attempt to give you and idea of what they are like.
  
 The first thing I noticed was the clarity/detail, my usual tubes are m8161/m8100 Ei 6hm5, there seems to my ears to be an extra level of detail over all other tubes I've tried, for instance one of my favourite albums  in Rush's Moving Pictures album the c3g picks out every single note of Geddy Lee's bass guitar with fantastic detail and texture, snare drums have a snap and energy I've not noticed in other tubes, bass is very powerful but never loose always tight, they also have a very low noise floor, classical music also sounds spectacular giving instruments space to breath, it gives me a sense that you are in the recording studio with the musicians, there is a level of realism the c3g that I just can't get from any other tube, also it doesn't seem to matter how long i'm listening for as they never get fatiguing, another thing as well they seem to pair very well with all the power tubes I have,6n6p, 6n6p-ir, and my 6sn7's.


----------



## OctavianH

First of all thanks for all who provided me this very useful info. I cannot provide you more information in return, but at least I can press the "Thanks" button.
  
 It is clear to me that the c3g seem to be a good improvement over my M8161. But the investment needed makes me think on the following aspects:
  
 1) I own MK2 and, adding the tubes I changed already, I can say I invested a sum of 250EUR. Not much, but I never intended to spend more because the major purpose was to learn and try. Upgrading MK2 with c3g makes me go for a 500EUR investment. Money are not a problem, but I have to see if MK2 is a solid performer for the following years to come or maybe the best choice would be to upgrade the tube amp completely, because the c3g investment will not be maximal beneficial because of MK2 limitations (entry level design, components used, and so on). Any advice on my concern? MK2+c3g will be fine and be a better investment over a more expensive tube amp?
  
 2) I play mostly FLAC encoded CDs because my main genre is rock/metal and in this area SACD or quality recordings are very limited. More than this, what I think it is the most important for me is the clarity, detail and good medium frequencies, because this music is fast, dense and the electrical instruments need to "vibrate" good in my ears (electrical bass, guitar, fast drumming). I listen also to movie soundtracks or classical, but not more than the previously mentioned genres. My main headphones are Beyers T1.2 which are by far the best I've owned, but still, I am not sure if I obtain the maximum from them with my MK2 and the iDAC2, which is the DAC I use. Here the question related to c3g would be, it makes sense to upgrade the MK2 with C3G (to maximum as seen in previous posts) and obtain more detailed sound, or maybe the limitation comes from MK2 specs or the iDAC2 PCM1793 chip which has its own signature and limitations?
 I tried the MK2 with my other 2 DACs (all entry level: NFB11 and Dr.Dac Prime) and the iDAC2 seemed to be, at least for me, the most appropriate. NFB2 sounded a little bit metalic, and the Dr.Dac somehow mufled and a little bit harsh. But solving these problems might introduce other limitations using the iDAC2.
  
 Well, these are my 2 cents on the C3G upgrade, based on my current setup and expectations. Any advice is welcomed.


----------



## Johnnysound

flex2d said:


> ​Thanks for the advice Jonnysound, yeah it looks pretty cool however could you recommend any other brands to consider for a good DAC.
> 
> Oh just got my LD mk2 on Thursday - Woohoo! I swapped out the valves for Mullard m8100 and some Russian 6n6p gold grid. The sounds really nice and spacious just the way I like it but feel the mids are lack detail and warmth.
> 
> ...



Hi Daniel, I think that the russian 6N6p are really good power tubes. The sound of the preamp will depend mostly on the driver tubes. I found the Yugo 6HM5 (a true triode as Gibosi says) to be the best sounding overall, with the advantage that, being an EF95 type, is just plug and play, and is not expensive. The C3G that people are talking about here is another breed of tube, but is rare, expensive, and need special adapters. I think it belongs to another stage of mods of the preamp, involving also power tubes. For the moment, the Yugo is a great option, in my opinion...

And about the DAC, there are many, but the SMSL M6 still looks great to me at the price. If you have other options, let me know...


----------



## Scutey

octavianh said:


> First of all thanks for all who provided me this very useful info. I cannot provide you more information in return, but at least I can press the "Thanks" button.
> 
> It is clear to me that the c3g seem to be a good improvement over my M8161. But the investment needed makes me think on the following aspects:
> 
> ...


 
 Hi OctavianH,
  
 You make some valid points about the mkii, I can't comment the mkii as I've never owned it, however since I bought my LD MKiii last summer I've seen incremental increases in sound with the different combinations of tubes used, I thought I'd found the best with the m8161/m8100/EI chm5 but then heard about the c3g, I have to say that for me it was worth it, I have two used pairs of c3g's at a cost of about $110.and has improved the sound far beyond what I thought possible from when I first bought it but for me it is now the end game sound and cost wise.


----------



## Flex2d

johnnysound said:


> Hi Daniel, I think that the russian 6N6p are really good power tubes. The sound of the preamp will depend mostly on the driver tubes. I found the Yugo 6HM5 (a true triode as Gibosi says) to be the best sounding overall, with the advantage that, being an EF95 type, is just plug and play, and is not expensive. The C3G that people are talking about here is another breed of tube, but is rare, expensive, and need special adapters. I think it belongs to another stage of mods of the preamp, involving also power tubes. For the moment, the Yugo is a great option, in my opinion...
> 
> And about the DAC, there are many, but the SMSL M6 still looks great to me at the price. If you have other options, let me know...


 

 ​Thanks again for the reply Johnnysound, I have bought some of these which I am currently using 6N6P / ECC99 / E182CC Novosibirsk Tubes GOLD grid
 I'm guessing these are the one you mean. I haven't tried the Yugo 6hm5 yet.. i'll try and pick some up.
  
 Thanks for the recommendations though appreciated!
  
 Best
  
 Daniel


----------



## gibosi

octavianh said:


> First of all thanks for all who provided me this very useful info. I cannot provide you more information in return, but at least I can press the "Thanks" button.
> 
> It is clear to me that the c3g seem to be a good improvement over my M8161. But the investment needed makes me think on the following aspects:
> 
> ...


 
  
 1) Given the initial cost of the LD, I totally understand your reluctance to invest in relatively expensive tubes. And the C3g is especially problematic in that the number of commercially available amps that use this tube is minuscule. And thus, it is likely that you won't be able to roll C3g in your next amp. That said, you can always sell them in Head-Fi's For-Sale forum for a good price allowing you to recover much of the original cost.
  
 In my case, I pushed the LD envelope even further and rolled a significant number of double triodes as well as the C3g. When it came time to purchase my next amp, I consciously considered my tube collection as a significant investment, one that would be difficult and expensive to replace, and deliberately purchased a custom-built amp that would allow me to maximally take advantage of my existing tube collection, including the C3g.
  
 2) Unfortunately, I have no experience with the iDAC, but perhaps others can comment. I can say that in my experience, if one component is changed, it is very hard to predict how it will impact the rest of the system. Sometimes all the parts play very nicely together and there seems to be a wonderful synergy. But other times, swapping in a new component changes everything for the worse. The only way to know for sure is to try.


----------



## Flex2d

Guys what would be the next set up from a LD mk2 for under £500 which i could still use my already purchased tubes?
  
 Suggestions welcome
  
 Thanks


----------



## Scutey

​I guess the obvious ones are the LD MK3 and the MK4, not heard the MK4 myself but from what I can remember it is regarded as superior to the MK3, that is well under £500.


----------



## OctavianH

scutey said:


> ​Ok, I've been using the C3G in my LD MKIII for two months now so I will attempt to give you and idea of what they are like.
> 
> The first thing I noticed was the clarity/detail, my usual tubes are m8161/m8100 Ei 6hm5, there seems to my ears to be an extra level of detail over all other tubes I've tried, for instance one of my favourite albums  in Rush's Moving Pictures album the c3g picks out every single note of Geddy Lee's bass guitar with fantastic detail and texture, snare drums have a snap and energy I've not noticed in other tubes, bass is very powerful but never loose always tight, they also have a very low noise floor, classical music also sounds spectacular giving instruments space to breath, it gives me a sense that you are in the recording studio with the musicians, there is a level of realism the c3g that I just can't get from any other tube, also it doesn't seem to matter how long i'm listening for as they never get fatiguing, another thing as well they seem to pair very well with all the power tubes I have,6n6p, 6n6p-ir, and my 6sn7's.


 
  
 From the picture I see that you use some adapters also for the power tubes. What power tubes do you use?


----------



## Scutey

​The power tubes in the pic are 6sn7 with a 6sn7 to ecc88 adapter, very highly regarded by Head-Fi'ers, they give a more refined sound than the 6n6 type, that particular 6sn7 is the Philips 6sn7wgta and this combination with c3g for drivers is the best sound I've heard in my LD.


----------



## fluffyberry

Hi i just got a pair of 'valvo 6CQ6' tubes for my Little Dot 1+, been running them for about an hour and I noticed black patches had formed at the top of the tube that kind of look like burn marks, is that normal?


----------



## shepperd

I have been badly bitten by the NOS craze and have to date a dozen pairs of various F95 gleaned from a variety of sources. I have a few more to discover and then I think I will give up the chase for the perfect tube. I will be unloading all the tubes I don't use, which include most of the ones mentioned on this forum and several that no one seems to have tried. I will list them is due course. They all have been run in; generally with 20 to 30 hrs to get a good handle on their characteristics. There are no bad tubes in the bunch, just ones I don't listen to. I have my favorites, which I will not sell and will mention them later. The thing is I only want to send a box full of tubes in Europe. I trust people in the audio world so I am quite happy to send them to whoever says "yes I will". Once you have verified the contents you can send me a check or whatever. I don't have a Pay pal acct. or anything else like that. I reckon I have paid around 200 euros for all these but I will let them go for 100 plus shipping (which isn't much more than 15 euros from here (France). There are no Mullards or Tungsol but there is a Voshhod and a bunch of crazy rare ones.  Since I am using them in a tube buffer type pre-amp, your experiences will vary from mine. At present I am going to try and find the Yugo (true triode) and maybe one or two more. It's exhausting listening to all these tubes and in the end there are only a few that meet my taste. By the way, for those who haven't tried, The standard Voshhod is a wonderful tube, one I keep coming back to as a reference.There seem to be a lot of them still out there but I notice prices are creeping up. They MUST have at LEAST 100+ hours on them to sound there best. Cheers and good listening.


----------



## Scutey

fluffyberry said:


> Hi i just got a pair of 'valvo 6CQ6' tubes for my Little Dot 1+, been running them for about an hour and I noticed black patches had formed at the top of the tube that kind of look like burn marks, is that normal?


 

 ​Hi, I think that's quite normal, had that on some of my tubes, I think
 that's filaments?, touching the top inside of the glass, I think!.


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## Scutey

Hi Shepperd, the Ei 6hm5 (yugo tube) is very good and quite cheap, there are a few sellers on Ebay.


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## TrollDragon

fluffyberry said:


> Hi i just got a pair of 'valvo 6CQ6' tubes for my Little Dot 1+, been running them for about an hour and I noticed black patches had formed at the top of the tube that kind of look like burn marks, is that normal?


 
 If you could post a picture of the tubes, that would help. I do believe what you are seeing is splash back from the getter flash (the silvery part on the tube glass) and is nothing to worry about.

 Bad leaking/gassy tubes will usually leave a white residue on the glass.


----------



## fluffyberry

trolldragon said:


> If you could post a picture of the tubes, that would help. I do believe what you are seeing is splash back from the getter flash (the silvery part on the tube glass) and is nothing to worry about.
> 
> Bad leaking/gassy tubes will usually leave a white residue on the glass.


 
 Hi i don't currently have any photos of my tubes but they do look alot like the one on the right, although it wasn't as silvery and had more of a dark colour tone to it


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## OctavianH

My Voskhods look the same as the ones on right, and they were like this even from the beginning. But what I have thought is that it is a kind of shield/paint on them and not a defect.
 What is also strange, is that I feel like the left channel is not so clear as the right one (might be a problem of the recording, of the Voskhods, of the Littledot or of my ears). When switching to EF92 and M8161 the problem is gone, they sound very good but since I switched from HD650 to T1.2 they provide too much bass (T1.2 is somehow V shaped) and the mids are somehow in the "back".
 So Yesterday I decided to switch again to EF95 and try the Voskhods. Maybe they are not fully burned in, I tried them somehow at 20h. But the M8161 sounded clearer from the beginning, so the detail level seemed a little bit better. Anyway, this is the last chance for me to keep the Voskhods, since the screws of the MK2 started to work harder, so if I switch again to EF92 I will remain there, at least until I find other 4 screws to replace these ones.
  

  
 Additional question to the "C3G" guys: When switching to c3g+adapters, what setting you have on Littledot? EF92? EF95?


----------



## Scutey

octavianh said:


> My Voskhods look the same as the ones on right, and they were like this even from the beginning. But what I have thought is that it is a kind of shield/paint on them and not a defect.
> What is also strange, is that I feel like the left channel is not so clear as the right one (might be a problem of the recording, of the Voskhods, of the Littledot or of my ears). When switching to EF92 and M8161 the problem is gone, they sound very good but since I switched from HD650 to T1.2 they provide too much bass (T1.2 is somehow V shaped) and the mids are somehow in the "back".
> So Yesterday I decided to switch again to EF95 and try the Voskhods. Maybe they are not fully burned in, I tried them somehow at 20h. But the M8161 sounded clearer from the beginning, so the detail level seemed a little bit better. Anyway, this is the last chance for me to keep the Voskhods, since the screws of the MK2 started to work harder, so if I switch again to EF92 I will remain there, at least until I find other 4 screws to replace these ones.
> 
> ...


 

 ​With my MK3, C3G is on the ef95 setting, so as long as you're set to ef95 it will be plug and play (with adapters of course!).
  
 With the M8161 I found the same thing, I have to say I can't really get on with the Voskhod, I know they are quite well regarded but I have 3 pairs and only one pair sounds good, 1 sounds ok, and 1 sounds terrible.
  
 On the other point about the "black patches" I have a pair of ef91 Osram with this, later today i'll dig em out and post a pic to see if this is what fluffyberry means.


----------



## OctavianH

scutey said:


> ​With my MK3, C3G is on the ef95 setting, so as long as you're set to ef95 it will be plug and play (with adapters of course!).
> 
> With the M8161 I found the same thing, I have to say I can't really get on with the Voskhod, I know they are quite well regarded but I have 3 pairs and only one pair sounds good, 1 sounds ok, and 1 sounds terrible.
> 
> On the other point about the "black patches" I have a pair of ef91 Osram with this, later today i'll dig em out and post a pic to see if this is what fluffyberry means.


 
  
 My Voskhods are made in '79 (I received some russian paper with them) but seem somehow to provide an inconsisstent sound (maybe like the volume or cleariness is somehow variable). This might be caused by not enought burn-in time. But unfortunately I do not know exactly how many hours I have listened to them or how many hours has the vendor burned them. Do not get me wrong, they sound good, but not as good as M8161 which are quite perfect if mids were more forward and bass less up-front (I guess here also my T1.2 comes in place to add more bass than original T1 and so on). The black patches seem to be a shield, because they have a perfect form, not a kind of gas or defect problem.
 What I will do, I will keep 1-2 weeks these Voskhods in place to see if the sound improves. I wait for some EI-Yugo 6HM5 to arrive and I will try them also. If I will not be 100% pleased, I will switch to EF92 and M8161.
 Regarding the C3G upgrade, I still wait to decide, because I like the Feliks Audio Espressivo because it has 3 Inputs and I have several DACs at home. I would like to have a Tube-amp where I do not have to switch the input cables all the time if I want to change the DAC... but I am not sure if Espresivo is much better than MK2. I like also the Elise, Euforia but I am not sure if they will be such a big improvement, on the music genres I am listening to, compared to the price difference.


----------



## Scutey

octavianh said:


> My Voskhods are made in '79 (I received some russian paper with them) but seem somehow to provide an inconsisstent sound (maybe like the volume or cleariness is somehow variable). This might be caused by not enought burn-in time. But unfortunately I do not know exactly how many hours I have listened to them or how many hours has the vendor burned them. Do not get me wrong, they sound good, but not as good as M8161 which are quite perfect if mids were more forward and bass less up-front (I guess here also my T1.2 comes in place to add more bass than original T1 and so on). The black patches seem to be a shield, because they have a perfect form, not a kind of gas or defect problem.
> What I will do, I will keep 1-2 weeks these Voskhods in place to see if the sound improves. I wait for some EI-Yugo 6HM5 to arrive and I will try them also. If I will not be 100% pleased, I will switch to EF92 and M8161.
> Regarding the C3G upgrade, I still wait to decide, because I like the Feliks Audio Espressivo because it has 3 Inputs and I have several DACs at home. I would like to have a Tube-amp where I do not have to switch the input cables all the time if I want to change the DAC... but I am not sure if Espresivo is much better than MK2. I like also the Elise, Euforia but I am not sure if they will be such a big improvement, on the music genres I am listening to, compared to the price difference.


 

 Yes it's always worthwhile burning them in longer as they might change/improve. The EI 6hm5 is a very nice tube, for me it's only second to the mighty c3g.
  
 I also was interested in the Elise after Mordy mentioned it however it is quite a lot more expensive than the LDs and I decided I could get fairly close sound wise to the Elise with the c3g for less money but of course everybody's situation is different.
  
 This is the tubes I have with scorch  marks, is this the sort of thing you both meant?, they have a nice sound, slightly microphonic and rather bright but the scorch marks have not affected the sound when in use.


----------



## OctavianH

scutey said:


> Yes it's always worthwhile burning them in longer as they might change/improve. The EI 6hm5 is a very nice tube, for me it's only second to the mighty c3g.
> 
> I also was interested in the Elise after Mordy mentioned it however it is quite a lot more expensive than the LDs and I decided I could get fairly close sound wise to the Elise with the c3g for less money but of course everybody's situation is different.
> 
> This is the tubes I have with scorch  marks, is this the sort of thing you both meant?, they have a nice sound, slightly microphonic and rather bright but the scorch marks have not affected the sound when in use.


 
  
 My decision for MK2 vs MK3 was simple, it is smaller and cheaper and with the difference I will try several sets of tubes. In my opinion, an MK2 upgraded with better tubes is almost the same as MK3 with the same tubes and much better than MK3 with stock tubes. At that time I knew only about Little Dot and Darkvoice, but regarding Darkvoice 336SE I read some reviews and all were considering it more "forgiving" and "warm" than the little dot. Others were complaining about "humming". So I decided to try the MK2. The smaller footprint helped me organize better my stuff on my desk. But now, when knowing about Feliks Audio and Woo Audio WA models, I start to think what would be the next step. Specwise, THD of Littledots is better than on Elise, so hard to say which one is the best option. What I would like to have, and I do not know any LD with this option, is to have 2-3 inputs, and connect all my DACs via RCA to it. It is then much simple to switch to different sources. This is why Espressivo made me think about it, but that one is the "low end" of Feliks and it is made in Europe. So it might be worse and just more expensive than the LDs. I will wait for the 6HM5 (I bought 4 pieces) and see how they compare to what I already own.
 Regarding power tubes, I saw that my board is V3, so it has to accept, according to the User Manual, power tubes like 6H30PI but on a search via ebay I observed astronomical prices. One guy from Russia was selling a matched pair with 300EUR!!! So I will keep my 6N6P. I guess it does not make sense to buy at this price, even if he claim 10 000 hours on them. I guess the capacitors and other parts of MK2 will fail before that...
  
 Later edit: Oooops, it seems I made a confusion between 6N30P-DR and 6H30PI but still they are 30EUR/piece. Any real improvement with these? Russian or Electro-Harmonix? Which one is better?


----------



## Scutey

octavianh said:


> My decision for MK2 vs MK3 was simple, it is smaller and cheaper and with the difference I will try several sets of tubes. In my opinion, an MK2 upgraded with better tubes is almost the same as MK3 with the same tubes and much better than MK3 with stock tubes. At that time I knew only about Little Dot and Darkvoice, but regarding Darkvoice 336SE I read some reviews and all were considering it more "forgiving" and "warm" than the little dot. Others were complaining about "humming". So I decided to try the MK2. The smaller footprint helped me organize better my stuff on my desk. But now, when knowing about Feliks Audio and Woo Audio WA models, I start to think what would be the next step. Specwise, THD of Littledots is better than on Elise, so hard to say which one is the best option. What I would like to have, and I do not know any LD with this option, is to have 2-3 inputs, and connect all my DACs via RCA to it. It is then much simple to switch to different sources. This is why Espressivo made me think about it, but that one is the "low end" of Feliks and it is made in Europe. So it might be worse and just more expensive than the LDs. I will wait for the 6HM5 (I bought 4 pieces) and see how they compare to what I already own.
> Regarding power tubes, I saw that my board is V3, so it has to accept, according to the User Manual, power tubes like 6H30PI but on a search via ebay I observed astronomical prices. One guy from Russia was selling a matched pair with 300EUR!!! So I will keep my 6N6P. I guess it does not make sense to buy at this price, even if he claim 10 000 hours on them. I guess the capacitors and other parts of MK2 will fail before that...
> 
> Later edit: Oooops, it seems I made a confusion between 6N30P-DR and 6H30PI but still they are 30EUR/piece. Any real improvement with these? Russian or Electro-Harmonix? Which one is better?


 
 I've never heard the mk2 but I guess with good tubes the difference between the mk2 and mk3 could be minimal. I guess with this audio thing we are always striving for a better sound, although I love my LD I started wondering about other amps, but I think I'll be keeping mine for awhile yet, as for the EH and 6n6p-ir, I did have both but sold the EH, of the two I think the 6n6p-ir is the better, maybe a bit cooler, I would say it has the edge over the EH but difference is again minimal.


----------



## gibosi

If anyone is rolling the 6AV6, you might also want to take a look at the 6BF6. The 6AV6 uses one section of a 12AX7, while the 6BF6 uses one section of a 12AU7, so less gain. The pin-out is the same, so simply cut off pins 5 and 6, set the LD for EF92, and they are plug-and-play.


----------



## MIKELAP

gibosi said:


> If anyone is rolling the 6AV6, you might also want to take a look at the 6BF6. The 6AV6 uses one section of a 12AX7, while the 6BF6 uses one section of a 12AU7, so less gain. The pin-out is the same, so simply cut off pins 5 and 6, set the LD for EF92, and they are plug-and-play.


----------



## Scutey

gibosi said:


> If anyone is rolling the 6AV6, you might also want to take a look at the 6BF6. The 6AV6 uses one section of a 12AX7, while the 6BF6 uses one section of a 12AU7, so less gain. The pin-out is the same, so simply cut off pins 5 and 6, set the LD for EF92, and they are plug-and-play.


 

 ​Would you say they are an upgrade from the EF92/95 tubes?


----------



## gibosi

scutey said:


> ​Would you say they are an upgrade from the EF92/95 tubes?


 
  
 I have not tried the 6BF6. However, back in the day, my favorite plug-and-play tube in the LD was a pair of 1950's GE 6VA6. 
  
 (Well, the 6VA6 and 6BF6 are "plug-and-play" after being "mutilated" by cutting off pins 5 and 6. lol. That is, they do not need pin-adapters.)
  
 I would expect the 6BF6 to sound similar to the 6AV6 and maybe even better due to its lower amplification factor. And again, a true triode is going to have less distortion and more linearity than any triode-strapped EF92/95. But of course, until someone tries them and tells us, I can't say for sure that they are an upgrade.....


----------



## Scutey

Thanks for that gibosi.


----------



## HondoMUC

Hi all,
will this fit also into LD 1+?

http://m.ebay.de/itm/142138665883?_trksid=p2349526.m2548.l4275&_mwBanner=1

BR


----------



## Barndoor

Yes, they'll fit and you don't even need to change any jumper settings from stock.


----------



## HondoMUC

barndoor said:


> Yes, they'll fit and you don't even need to change any jumper settings from stock.


 
  
 Thanks! I'm hoping so but I bought a used one. So I need to open it anyway to see whats going on inside


----------



## Riddick

Hi,
  
 long time lurker here.
  
 After a long Journey with the Beyerdynamic DT-770 Edition 250ohm, Sennheiser HD-25-1 II, Audio Technica ATH-M50x, Beyerdynamic T50p and the AKG K545, I finally found myself buying the Beyerdynamic T90.
  
 After powering it with my Technics Solid State-Amplifier, I decided to get the Little Dot MK2 as a dedicated HP-Amp and the Fiio E10k as a DAC.
  
 Now this Guide came into play and I ordered the VOSKHOD 6ZH1P-EV as driver tubes and some Novosibirsk 6N6P-i as power tubes, because I found the sound with the stock tubes a bit harsh in the high-ends.
  
 I hope I made the right choice and the signature sound "warms" a little more... I know the T90's are not very forgiving with some kind of music.
  
 I mostly listen to 90's Hip-Hop, Punk, Electronic/IDM and Jazz...
  
 Question: Can I just roll the new tubes without changing any jumper settings?


----------



## OctavianH

riddick said:


> Hi,
> 
> long time lurker here.
> 
> ...


 
 Answer: YES. No jumper setting is needed for Voskhod since they are EF95 as the stock tubes and the "factory setting" of jumpers is EF95.
  
 Regarding to your concerns, the Voshkods are more neutral than the stock tubes, but more detailed also. Do not judge them in the first hours, because many claim they need 60-120hrs to burn in and provide the final sound. I have the same problem as you will have, I am still somewhere at 20-30hrs and wait for them to "evolve". Using them with Beyerdynamic T1.2 and no harshness or other thing is present.


----------



## Riddick

Thanks for the quick answer!
  
 I'm quite pleased with the stock tubes, maybe to the fact the LD MKII is my first "real" Tube Amp. But the sound can get harsh by times.
  
 Do the Voskhod run well with the Novosibirsk, also? And does the jumper only affect the Driver Tubes used?


----------



## OctavianH

Yes, I think I have exactly the same setup like you at the moment.


----------



## Riddick

That sounds promising. 
  
 Waiting for the tubes to arrive.
  
 Will give them their time, when they are here.
  
 Do you bother to burn-in with pink noise?


----------



## Scutey

riddick said:


> Hi,
> 
> long time lurker here.
> 
> ...


 

 Hi Riddick,
  
 The 6N6P-I is a good tube, another decent tube for taming highs is the 6N6P they have a slightly warmer, softer sound.
  
 I had the T90s and was very impressed with the detail but slightly disappointed with the bass, however I only kept them for two weeks, but i'm now beginning to think I might have been a bit hasty!..
  
 On the burn in you could use pink noise but I usually just use a playlist of the sort of stuff i'm going to be listening with them, another thing and this of course is just preference and open to debate!, but I only do  about 5 hours of burn in (not listening) and then just listen to them and (hopefully!) enjoy any changes I hear.


----------



## Johnnysound

scutey said:


> ​The power tubes in the pic are 6sn7 with a 6sn7 to ecc88 adapter, very highly regarded by Head-Fi'ers, they give a more refined sound than the 6n6 type, that particular 6sn7 is the Philips 6sn7wgta and this combination with c3g for drivers is the best sound I've heard in my LD.




Hi Scutey, I do agree with your sonic impressions of the C3G/6sn7 combo in the LDIII. Definitely more refined than the 6n6 type, at first sight. But after some good listening hours this "refinement" shows itself as a real step ahead in sound quality. More open, relaxed, and at the same time detailed, dynamic, with tuneful bass and a much greater sense of dimensionality for the musical presentation. Another level, clearly superior to the stock tubes. And, while this quality was obvious thru my nice Audio Technica headphones, it really shined with the LDIII in preamp duties, and a pair of good monitor speakers. You know, with all due respect for the great, hi tech headphones around, there is no substitute for real air and space between you and the music. This is of course a different kind of test, and a tough one by the way, with ss amplifiers in the middle of it. And, have to admit that this is not "pure tube" as with headphones. Anyway, the C3gs are terrific driver tubes, powerful, neutral, with extreme bandwith, can sound raw if not properly matched, and will show all the flaws of the output tubes. And remember, 6SN7s are not designed as power tubes. Some well regarded 6SN7 tubes sounded mediocre with the C3gs in front. A few were a great match, for example the ATT (Hitachi Japan) 6SN7GTB, or the Tung Sols 6SN7GT, tall bottles from the fifties. Some Sylvanias also sounded great... of course, true output tubes, like the big 6AS7Gs can be driven beautifully by the C3gs, but this is another chapter...


----------



## Riddick

scutey said:


> Hi Riddick,
> 
> The 6N6P-I is a good tube, another decent tube for taming highs is the 6N6P they have a slightly warmer, softer sound.
> 
> ...


 
  
 I first had the same opinion as you regarding the Bass on the T90. But these Headphones are very picky with the Music you feed them with. Sometimes when I think this or that Album won't sound great on them, it happens that they surprise me...
  
 I think they need a real good Production to develop their full potential. Obvious Bass heavy productions by the likes of Dr. Dre, Dead Prez, Gucci Mane, Timbaland etc.
 They really surprised me when I put on a Vinyl Rip of Rage against the Machine's first Album. Or old Slayer. But you can't always tell...


----------



## Scutey

johnnysound said:


> Hi Scutey, I do agree with your sonic impressions of the C3G/6sn7 combo in the LDIII. Definitely more refined than the 6n6 type, at first sight. But after some good listening hours this "refinement" shows itself as a real step ahead in sound quality. More open, relaxed, and at the same time detailed, dynamic, with tuneful bass and a much greater sense of dimensionality for the musical presentation. Another level, clearly superior to the stock tubes. And, while this quality was obvious thru my nice Audio Technica headphones, it really shined with the LDIII in preamp duties, and a pair of good monitor speakers. You know, with all due respect for the great, hi tech headphones around, there is no substitute for real air and space between you and the music. This is of course a different kind of test, and a tough one by the way, with ss amplifiers in the middle of it. And, have to admit that this is not "pure tube" as with headphones. Anyway, the C3gs are terrific driver tubes, powerful, neutral, with extreme bandwith, can sound raw if not properly matched, and will show all the flaws of the output tubes. And remember, 6SN7s are not designed as power tubes. Some well regarded 6SN7 tubes sounded mediocre with the C3gs in front. A few were a great match, for example the ATT (Hitachi Japan) 6SN7GTB, or the Tung Sols 6SN7GT, tall bottles from the fifties. Some Sylvanias also sounded great... of course, true output tubes, like the big 6AS7Gs can be driven beautifully by the C3gs, but this is another chapter...


 

 Hi Johnnysound.
  
 I agree with you too!. The first time I used C3Gs the difference was fairly subtle at first but the more I listened with my favourite sounds the more I realised that the reputation these tubes have was correct, I won't go into detail again on their sound as you've explained it so eloquently but everything you said is true, the C3G along with a good 6SN7 pushes the LD way beyond the stock tubes, and indeed, many of the popular upgrade ef92/92/6n6 combos.


----------



## Scutey

riddick said:


> I first had the same opinion as you regarding the Bass on the T90. But these Headphones are very picky with the Music you feed them with. Sometimes when I think this or that Album won't sound great on them, it happens that they surprise me...
> 
> I think they need a real good Production to develop their full potential. Obvious Bass heavy productions by the likes of Dr. Dre, Dead Prez, Gucci Mane, Timbaland etc.
> They really surprised me when I put on a Vinyl Rip of Rage against the Machine's first Album. Or old Slayer. But you can't always tell...


 

 ​Agreed, I found most of my disappointment with the T90 was with (some) rock/metal but with less aggressive music and especially classical I found them to be spectacular, Detail, imaging and soundstage was wonderful, unfortunately I bought them at the same time as my LD MK3 and the tubes I was trying at the time probably didn't compliment them, if I had persevered with them a bit longer and used them with the C3g's I'd probably still have them.


----------



## OctavianH

Where do you still find T90? I thought they are out of production.
  
 By the way, since talking about Slayer, the latest album still does not sound as I expect on any cans I have. After the intro goes out, the Repentless does not sound so powerful/fast as I wound expect... Hard to say why, maybe like Machine Head was saying, it is "all in my head"...


----------



## Scutey

octavianh said:


> Where do you still find T90? I thought they are out of production.
> 
> By the way, since talking about Slayer, the latest album still does not sound as I expect on any cans I have. After the intro goes out, the Repentless does not sound so powerful/fast as I wound expect... Hard to say why, maybe like Machine Head was saying, it is "all in my head"...


 

 ​There appears to be some still available in England, I guess the remaining stock is gradually filtering through the retail system.
  
 If the Slayer album doesn't sound so good on any of your gear maybe it's the recording/production of the album.


----------



## Riddick

You can find T90's still everywhere in Germany. And maybe the old Production of Slayer Albums was something different.
  
 We're talking about Rick Rubin, after all.


----------



## Scutey

riddick said:


> You can find T90's still everywhere in Germany. And maybe the old Production of Slayer Albums was something different.
> 
> We're talking about Rick Rubin, after all.


 

 ​Lol he didn't exactly do a great job on Metallica's Death Magnetic either!.


----------



## Riddick

The 45rpm Vinyl sounds great... Oh wait...


----------



## OctavianH

riddick said:


> The 45rpm Vinyl sounds great... Oh wait...


 
 I am exchanging DACs here to understand the best option I have. Hard to say if it is a real problem or a mental one. Tried also the latest Paradise Lost album and sounds at 9/10. Maybe a Chord 2Qute will be the solution, all say it is very detailed...


----------



## i luvmusic 2

riddick said:


> The 45rpm Vinyl sounds great... Oh wait...


 
 VINYL'S are great...............


----------



## Riddick

> Now this Guide came into play and I ordered the VOSKHOD 6ZH1P-EV as driver tubes and some Novosibirsk 6N6P-i as power tubes, because I found the sound with the stock tubes a bit harsh in the high-ends.


 
  
 The new Tube Set arrived savely, today.
  
 The first thing I noticed when I plugged them in was that they are dead quiet, whereas the Stock Tubes left a slighty hum in one Channel.
  
 I'm impressed!
  
 First time listening I noticed an increase in the details and it's slightly more "airy" (that's a really good thing, because the stock tubes already satisfied me in that matter)
  
 Now it's time for extensive listening...


----------



## OctavianH

I have only one problem with the Voskhods, the clarity of the drum kit, more exactly the cymbals. Hard to explain because I am no "drummer" or expert but according to this:
  

 I guess my problem is with the "Hi-Hat cymbals" or maybe "Ride cymbal"? Anyway, do they sound clear to you? For me they seem to be somehow muddy.


----------



## Riddick

octavianh said:


> I have only one problem with the Voskhods, the clarity of the drum kit, more exactly the cymbals. Hard to explain because I am no "drummer" or expert but according to this:
> 
> 
> I guess my problem is with the "Hi-Hat cymbals" or maybe "Ride cymbal"? Anyway, do they sound clear to you? For me they seem to be somehow muddy.


 

  Can you recommend me a Song for Reference?
  
I think I read a review of the T90's somewhere and the reviewer said something with a problem with cymbals, because of the Beyer-Peak... I'll post a link, if I find it...
  
 nvm
  
 Listening to Niagara's "City Walk" right now, and all appears to be quite clear... But like you said, I'm no Drummer or Expert, either...


----------



## OctavianH

I guess it was Paradise Lost - Terminal. This track has a lot of "drumming" in it and those cymbals. But I guess you need to have it at least FLAC encoded... might be a Beyer issue?
  
 https://www.youtube.com/watch?v=FOXrpTL1OTg


----------



## Riddick

octavianh said:


> I guess it was Paradise Lost - Terminal. This track has a lot of "drumming" in it and those cymbals. But I guess you need to have it at least FLAC encoded... might be a Beyer issue?
> 
> https://www.youtube.com/watch?v=FOXrpTL1OTg


 
  
 So, you have this problem with all your Tubes, or only with the Voskhod's?
  
 Paradise Lost? Great. Wanted to revisit them anyhow... I listen to Flac's 98% of the time, since I have the T90's...


----------



## OctavianH

riddick said:


> So, you have this problem with all your Tubes, or only with the Voskhod's?
> 
> Paradise Lost? Great. Wanted to revisit them anyhow... I listen to Flac's 98% of the time, since I have the T90's...


 
 Well, hard to say because I have the following tubes:
  
 - stock chinese ones - removed a long time ago, sounded crappy to me
 - Voskhod drivers - this very small "unclarity" on some drumming and cymbals
 - Mullard 8161 - these seem to be better but have a different sound signature, much more bass so maybe this is why I cannot identify the problem...
  
 I will wait until Voskhods have 120hrs, because many claim that they need a lot of burn in, and also some claim that I need 100hrs on T1 also.
  
 But judging from the comparison on this thread, even the creator assigned Deetail = 19 to Voskhod and Detail = 20 to Mullard 8161. So maybe this is the problem.


----------



## Riddick

octavianh said:


> Well, hard to say because I have the following tubes:
> 
> - stock chinese ones - removed a long time ago, sounded crappy to me
> - Voskhod drivers - this very small "unclarity" on some drumming and cymbals
> ...


 
  
 I have to say, the Voskhod's make a HUGE improvement for me with the T90's...
  
 As I consider to buy the Mullard's also later this year, what are your "go to" Tubes with your Beyer's? Do you like the Voskhod's or the Mullard's more?
  
 What Power Tube's do you use with either?


----------



## OctavianH

riddick said:


> I have to say, the Voskhod's make a HUGE improvement for me with the T90's...
> 
> As I consider to buy the Mullard's also later this year, what are your "go to" Tubes with your Beyer's? Do you like the Voskhod's or the Mullard's more?
> 
> What Power Tube's do you use with either?


 
 I have as power tubes only 6N6P russians. I never change them, only the drivers. And I listen 99% to metal, so keep that in mind.
  
 I would say Voskhod sound more "direct" and somehow "fast", which are good ingredients to rock music.
  
 The Mullards (8161) are more detailed, bassy and sound more refined, but for me, since I started using the T1 they are not enough aggressive.
  
 I think these Mullards are better on other genres than the Voskhods. I will give you an example: I listened to some Primordial last week, for example "Gallows Hymn".
  
 The guitar sounded too "polite" on the Mullards, where the Voskhods added some harshness and aggressivity. But this came with a small cost, a little lack of detail in the cymbals.
  
 What to say, it is not very easy do describe what you hear. Both tubes are very good ones and a huge improvement over the stock ones.
  
 But I guess a very big influence has the source used (DAC). I use here at the moment the iDAC2 which is somehow warm in tonality. And it might add some of this warmness to the overall sound.


----------



## Scutey

riddick said:


> I have to say, the Voskhod's make a HUGE improvement for me with the T90's...
> 
> As I consider to buy the Mullard's also later this year, what are your "go to" Tubes with your Beyer's? Do you like the Voskhod's or the Mullard's more?
> 
> What Power Tube's do you use with either?


 

 ​The 6n6p-ir is a very good power tube, it's a little cooler than the 6n6p, also faster, has more attack in drums, cymbals and a tad more detail, we're not talking a huge difference but it is there, don't get me wrong the 6n6p is good as well, the slightly warmer signature works well with, bright ish Beyers.
  
 As for drivers, just my experience of course!, I found the warmish m8161/m8100, paired well with the coolish 6np-ir, which I found good with metal/rock and also classical.


----------



## Scutey

octavianh said:


> I have as power tubes only 6N6P russians. I never change them, only the drivers. And I listen 99% to metal, so keep that in mind.
> 
> I would say Voskhod sound more "direct" and somehow "fast", which are good ingredients to rock music.
> 
> ...


 
 OctavianH,
  
 Going on what you've said I think you'd like the 6n6p-ir, it is quite a fast power tube, good detail and bass thump, That  (might!) compliment the Voskhods.


----------



## OctavianH

scutey said:


> OctavianH,
> 
> Going on what you've said I think you'd like the 6n6p-ir, it is quite a fast power tube, good detail and bass thump, That  (might!) compliment the Voskhods.


 
  
 OK Scutey, I value your opinion, so I will try to find some 6N6P-IR to try. I guess these "-IR" ones works on MK2.


----------



## Riddick

scutey said:


> ​The 6n6p-ir is a very good power tube, it's a little cooler than the 6n6p, also faster, has more attack in drums, cymbals and a tad more detail, we're not talking a huge difference but it is there, don't get me wrong the 6n6p is good as well, the slightly warmer signature works well with, bright ish Beyers.
> 
> As for drivers, just my experience of course!, I found the warmish m8161/m8100, paired well with the coolish 6np-ir, which I found good with metal/rock and also classical.


 
  
 My power tubes are the 6N6P-i, to be exact... I'll have to say I like the sound in complimentation with the Voskhod's right out the box!
  
 The sound signature is bright overall, but not harsh... The details and soundstage are phenomenal to my (new to tube-sound) ears...
  
 I think I've made a good decision... The drivers of the T90 are swinging and the HP begins to "sing" with the right music.
  
 I consider to get Mullards for a warmer signature, then... (if needed in the future)
  
 EDIT: I'm fascinated by how quiet the tubes are... I turn up the Volume to max., absolutely no noise floor...


----------



## Scutey

octavianh said:


> OK Scutey, I value your opinion, so I will try to find some 6N6P-IR to try. I guess these "-IR" ones works on MK2.


 

 ​Yes there shouldn't be a problem in a mk2. Don't get me wrong the differences are not huge, but there is a difference, it's a case the more you listen the more you notice.


----------



## Scutey

riddick said:


> My power tubes are the 6N6P-i, to be exact... I'll have to say I like the sound in complimentation with the Voskhod's right out the box!
> 
> The sound signature is bright overall, but not harsh... The details and soundstage are phenomenal to my (new to tube-sound) ears...
> 
> ...


 

 Yes that makes a difference!, there's less difference between the -I and the -ir.
  
 I only had the T90 for about 2 weeks, the thing I remember about the T90 was detail, imaging and soundstage, I have to say that I'm thinking of getting another pair and giving them another go!..
  
 Btw if you try the mullards you should notice they are warmer, especially the m8100.
  
 Enjoy your T90s!.


----------



## OctavianH

scutey said:


> ​Yes there shouldn't be a problem in a mk2. Don't get me wrong the differences are not huge, but there is a difference, it's a case the more you listen the more you notice.


 
  
 I found some 6N6P-IR with silver marking:
  

  
 These are the ones you are talking about? I've seen also some "gold marked" ones but I am not sure if it is a difference.
 The seller calls these "high durable". Why? More working hours than average? I cannot find anywhere the guaranteed working hours (2000hrs or 5000hrs or whatever)


----------



## Scutey

Quote: 





octavianh said:


> I found some 6N6P-IR with silver marking:
> 
> 
> 
> ...


 
 Here is a pic of my 6n6p-ir
  
 Yes those are the ones, I don't think there is much difference for  "gold marked", as to the working hours I wasn't able to find much info on the ir, I did find a site that said they were good for 10,000 hours but I can't be sure about that, the 6n6p-i  is a minimum of 500 hours and I think that was due to it's application, but in a less demanding role ie home audio it should be considerably more so, I think, using this as a guide the 6n6p-ir should be 1000 + hours, but don't take that as absolute!, there might be others on here with more knowledge than I have of this tube!.


----------



## MIKELAP

octavianh said:


> scutey said:
> 
> 
> > ​Yes there shouldn't be a problem in a mk2. Don't get me wrong the differences are not huge, but there is a difference, it's a case the more you listen the more you notice.
> ...


 
 Guaranteed is a big word but they are very durable and for $25.00 a pair a good deal  i also have these tubes they are made in 1989 of the ones that are around  they seem to be all made in that year i got them 3-4 years ago  here'a a link that's what i paid    http://www.ebay.com/itm/6N6P-IR-ECC99-E182CC-Tubes-NOS-GOLD-grid-Same-Date-Codes-Lot-of-2-Pcs-/331583956458?hash=item4d33f1a5ea:g:cToAAOSw5cNYH7R1                                                                                                                                          http://www.ebay.com/itm/6N6P-IR-ECC99-E182CC-high-durable-double-triode-tubes-Lot-of-2-NOS/262456704789?_trksid=p2047675.c100005.m1851&_trkparms=aid%3D222007%26algo%3DSIC.MBE%26ao%3D1%26asc%3D41404%26meid%3Df614a7c17b0b41f1abf87cd005f66258%26pid%3D100005%26rk%3D2%26rkt%3D6%26sd%3D331583956458


----------



## Scutey

mikelap said:


> Guaranteed is a big word but they are very durable and for $25.00 a pair a good deal  i also have these tubes they are made in 1989 of the ones that are around  they seem to be all made in that year i got them 3-4 years ago  here'a a link that's what i paid    http://www.ebay.com/itm/6N6P-IR-ECC99-E182CC-Tubes-NOS-GOLD-grid-Same-Date-Codes-Lot-of-2-Pcs-/331583956458?hash=item4d33f1a5ea:g:cToAAOSw5cNYH7R1                                                                                                                                          http://www.ebay.com/itm/6N6P-IR-ECC99-E182CC-high-durable-double-triode-tubes-Lot-of-2-NOS/262456704789?_trksid=p2047675.c100005.m1851&_trkparms=aid%3D222007%26algo%3DSIC.MBE%26ao%3D1%26asc%3D41404%26meid%3Df614a7c17b0b41f1abf87cd005f66258%26pid%3D100005%26rk%3D2%26rkt%3D6%26sd%3D331583956458


 

 ​Seeing as these are power tubes, shouldn't they be matched?


----------



## Riddick

Excuse me, if this is a dumb question...
  
 I want to change my Headphone chain a bit, because I want to play my Vinyl records through my Headphones.
  
 The new chain would be as followed:
  
 Technics SL-1200 & Laptop w/ FiiO E10k -> Pioneer SX535 (Phono & Aux) -> Tape-out -> (Dynavox TPR-2 with Telefunken ECC82] -> Little Dot MK2 -> T90
  
 or maybe just:
  
 Technics SL-1200 & Laptop w/ FiiO E10k -> Dynavox TPR-2 (Phono & Line-In) -> Little Dot MK2 -> T90
  
 But for the Phono Stage alone, I think it'll sound better through the SX535?
  
 In general, this is possible without breaking the LD Mk2 due to Voltage Issues... Should I integrate the TPR-2 in this chain or better leave it out?


----------



## MIKELAP

scutey said:


> mikelap said:
> 
> 
> > Guaranteed is a big word but they are very durable and for $25.00 a pair a good deal  i also have these tubes they are made in 1989 of the ones that are around  they seem to be all made in that year i got them 3-4 years ago  here'a a link that's what i paid    http://www.ebay.com/itm/6N6P-IR-ECC99-E182CC-Tubes-NOS-GOLD-grid-Same-Date-Codes-Lot-of-2-Pcs-/331583956458?hash=item4d33f1a5ea:g:cToAAOSw5cNYH7R1                                                                                                                                          http://www.ebay.com/itm/6N6P-IR-ECC99-E182CC-high-durable-double-triode-tubes-Lot-of-2-NOS/262456704789?_trksid=p2047675.c100005.m1851&_trkparms=aid%3D222007%26algo%3DSIC.MBE%26ao%3D1%26asc%3D41404%26meid%3Df614a7c17b0b41f1abf87cd005f66258%26pid%3D100005%26rk%3D2%26rkt%3D6%26sd%3D331583956458
> ...


 
 I never bothered with that and never heard a difference as long as they have similar structure and date, like same year  its good


----------



## Scutey

mikelap said:


> I never bothered with that and never heard a difference as long as they have similar structure and date, like same year  its good


 

 ​that's good to know as matched are always more expensive (surprise!).
  
 On a separate issue have you ever used Foton 6N8S in your LD, or know of anyone who had?, my curiosity has got the better of me, again!.


----------



## gibosi

scutey said:


> On a separate issue have you ever used Foton 6N8S in your LD, or know of anyone who had?, my curiosity has got the better of me, again!.


 
  
 The 6N8S is simply the Russian version of the 6SN7GT. And in my amp which is designed to use 6SN7 as a driver, I don't find them to be all that good. But of course, my ears and my gear... YMMV.


----------



## TrollDragon

scutey said:


> ​Seeing as these are power tubes, shouldn't they be matched?


 

 Power tubes is a bit of a misnomer, the LD amplifiers are really just preamps.
  
 The matching of power tubes is required in Push/Pull configurations where both tubes are required to draw the same amount of current. The output tubes of the LD amps are configured in a Cathode Follower configuration and tube matching is not required.


----------



## Scutey

trolldragon said:


> Power tubes is a bit of a misnomer, the LD amplifiers are really just preamps.
> 
> The matching of power tubes is required in Push/Pull configurations where both tubes are required to draw the same amount of current. The output tubes of the LD amps are configured in a Cathode Follower configuration and tube matching is not required.


 

 ​Thanks for that TrollDragon, that's that cleared up


----------



## misteral201103

Hi Everyone,
  
 I have a couple of questions and I apologize in advance if they have already been asked and answered! I have, of course, gone through the guide at the start of the thread (brilliant!) and have gone through the first ten and last ten pages. I have a LD MkIII, fed by a Fiio X5 (first gen), feeding Audioquest Nighthawks (and sometimes LZA4s, though not often)
  
 I'm looking for tubes which will give a good representation across the frequency range (if either end were more important, perhaps it's high frequency, since I have Nighthawks and probably can't afford much roll-off up there!) but most importantly, soundstage! Both width and depth (but perhaps especially width!)
  
 Currently on order, I'm waiting for Mullard M8161 and Tung Sol 6AK5. I'd love to try the Sylvania 5654W but they are currently out of stock (and I don't know if they'll be back). I'm in China so it's easy to find a wide range of tubes, but some are elusive!
  
 Does anyone have any recommendations for hands-down, "you won't believe how out of your head this is!" soundstaging? Ok, maybe that's too much! I'll settle for - 'this is the widest/deepest soundstage I have heard through the Little Dot'
 Also - for a tube like the JAN 5654W - how much difference does the manufacturer make? I was aiming for Sylvania but I think I can get some GE JANs - would they be comparable?
  
 Many thanks in advance for any advice!


----------



## MIKELAP

You want a bigger soundstage get Senns HD800 series


----------



## HondoMUC

Hi all,
  
 just got my Voshkod 6ZH1P-EV (6J1P-EV) for 1+.
 They do not sound as warm as the original ones. A bit harsh with some buzzing on some instruments.
  
 Do they just need burn-in? Or in case I like the warmer more tubey sound signature, which tubes would you suggest?
  
 BR


----------



## gulakpi

hondomuc said:


> .........Or in case I like the warmer more tubey sound signature, which tubes would you suggest?
> 
> BR


 
  
 I suggest the Mullards M8100 and the Western Electric's 408 (or do you have the Western Electric 408 as stock tubes?)


----------



## Scutey

I would try and burn them in for a few houras they might mellow out, or it could be you have a duff pair, i've had that problem with Voskhods, as memtioned you will get a nice tubey sound from the m8100 especially with 6n6p for powers, another cheap option is the EI 6hm5, this produces a lovely sound


----------



## HondoMUC

gulakpi said:


> I suggest the Mullards M8100 and the Western Electric's 408 (or do you have the Western Electric 408 as stock tubes?)


 
  
 No, I did have the chines ones-- 6Ji or so. I was surprised they were pretty good already despite of what was said. Thanks for the suggestions, I plannned to get the Mullards also.
 Because why tubey rock n' rolla when you just try two pair


----------



## HondoMUC

scutey said:


> I would try and burn them in for a few houras they might mellow out, or it could be you have a duff pair, i've had that problem with Voskhods, as memtioned you will get a nice tubey sound from the m8100 especially with 6n6p for powers, another cheap option is the EI 6hm5, this produces a lovely sound


 
  
 Ok thanks. I will try some burn in. Mullards are on my list. Hope to get the 6n6p version.


----------



## gulakpi

gibosi said:


> In a nutshell, when pentodes are strapped as triodes, linearity typically goes out the window and distortion increases. And this is the model used in a Little Dot. That is, a pair of 6AK5, pentodes, are strapped as triodes.
> 
> The C3g, also a pentode, is unique in that it was deliberately designed to be strapped as a triode, with linearity and distortion levels comparable to a 6SN7, one of the finest tubes available for use in vacuum tube audio.
> 
> ...


 
 Hi Gibosi,
  
 Reading your suggestions, I am keen to try out the 12AX7 and 6DJ8/6922 --- which I have a few on hand.  
 I plan to build myself an adapter which will use one of these dual-triode tube for both L&R channels, and hopefully do not have worry about the unused halves of these dual triodes.
  
 Having said that, can I expect the sound from these "true triodes" comparable to the 6HM5 and 6AV6?  
 An interesting project, may take some patience to mount the pins mechanically!


----------



## MIKELAP

Quote: 





gulakpi said:


> gibosi said:
> 
> 
> > In a nutshell, when pentodes are strapped as triodes, linearity typically goes out the window and distortion increases. And this is the model used in a Little Dot. That is, a pair of 6AK5, pentodes, are strapped as triodes.
> ...


 
 This is how I made these adapters


----------



## TrollDragon

mikelap said:


> This is how I made these adapters.


 
  
 Those were really great times in this thread!


----------



## gibosi

gulakpi said:


> Having said that, can I expect the sound from these "true triodes" comparable to the 6HM5 and 6AV6?
> An interesting project, may take some patience to mount the pins mechanically!


 
  
 Personally, I found 6SN7 and 6DJ8 to be better than 12A-7, and significantly better than 6HM5 and 6AV6.
  
 My "adapter" cannot be called elegant (TrollDragon) or steampunk (Mikelap). It was simply butt ugly. lol  But in its favor, it was very simple and easy to configure.
  
 Although some of the links are broken, here is the list of parts I used:
  
 http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/5760#post_10435226
  
 My Little "Monster" Dot
  

  
 And the 7-pin test sockets allowed me to roll C3g with no disassembly.


----------



## HondoMUC

Hey, I got some IEm or whatever (like the buzzing of a fly) on my LD 1+. Not constantly but contantly repeating itself. It is only on the right channel.
 Voluming up from 0, right channel is also the first one to hear. Is it the source, the amp interior or the tube (connector)?


----------



## i luvmusic 2

mikelap said:


> Quote:
> 
> 
> 
> ...


 
  
  


trolldragon said:


> mikelap said:
> 
> 
> > This is how I made these adapters.
> ...


 
  
  


gibosi said:


> gulakpi said:
> 
> 
> > Having said that, can I expect the sound from these "true triodes" comparable to the 6HM5 and 6AV6?
> ...


 
 Those were the days(Really good times).


----------



## TrollDragon

The liquor bottle tube adapters were one of the best!!


----------



## i luvmusic 2

trolldragon said:


> The liquor bottle tube adapters were one of the best!!


 
 The CROWN ROYAL have the smoothest sound


----------



## gulakpi

mikelap said:


> This is how I made these adapters


 
 Hi Mikelap, thank you!  You are helpful all the time!
 The setup is elegant, but probably beyond my skills in DIY plumbing !  
 Quite a bit of precision work there with the brass tubing there, which I'm not too confident!  Haha!


----------



## gulakpi

trolldragon said:


> Those were really great times in this thread!


 
  
 This thread has always been great!    
 We all found it very informative, people sharing experiences and joy!
 Nicest people here!


----------



## gulakpi

i luvmusic 2 said:


> The CROWN ROYAL have the smoothest sound


 
  
 Rolling booze?!!


----------



## MIKELAP

gulakpi said:


> mikelap said:
> 
> 
> > This is how I made these adapters
> ...


 

 ​Atleast the C3G and the 6SN7 adapters can be purchased ready made which is pretty much all you need really ,BUT half the fun is trying new tubes .Have fun.


----------



## gulakpi

I will work on the adapters as soon as the materials come in.
 I have built the C3g adapters before and would like to work on the 6DJ8 now, and will post photos when it is done!
  
 I have a few used Siemens and Russian ECC88/6922 on hand.  Are there any inexpensive (U$15-50 each) 6DJ8 you folks have good results in?  Some of these vintage  6DJ8 can be a bit costly (to me!) which I probably don't  want to spend on now.


----------



## gibosi

gulakpi said:


> I have a few used Siemens and Russian ECC88/6922 on hand.  Are there any inexpensive (U$15-50 each) 6DJ8 you folks have good results in?  Some of these vintage  6DJ8 can be a bit costly (to me!) which I probably don't  want to spend on now.


 
  
 I haven't been in the market for 6DJ8/ECC88 for a long time, but I would think that if you are patient, you can find tubes manufactured by Philips, in their Heerlen, Holland factory, often labeled Amperex, and in their Blackburn, Britain factory, often labeled Mullard, in this price range. Also, Tesla-brand tubes might be worth trying.


----------



## MIKELAP

gulakpi said:


> I will work on the adapters as soon as the materials come in.
> I have built the C3g adapters before and would like to work on the 6DJ8 now, and will post photos when it is done!
> 
> I have a few used Siemens and Russian ECC88/6922 on hand.  Are there any inexpensive (U$15-50 each) 6DJ8 you folks have good results in?  Some of these vintage  6DJ8 can be a bit costly (to me!) which I probably don't  want to spend on now.


. In the past some have reported some hum when using 6DJ8 tubes in my case adapter was fine no hum


----------



## OctavianH

Anyone noticed this new model?
  
 [size=20.007px]Little Dot MK III SE[/size]
 http://littledot.net/forum/viewtopic.php?f=9&t=10332&sid=3900954372c5dbe339d5faaf0673b1c5


----------



## HondoMUC

Hi, just ordered these: 6HM5 EC900 EI Yugoslavia
 Could not find them in the Guide. Are they running on standard  settings or do I need to switch jumpers?
 Thx!


----------



## gulakpi

hondomuc said:


> Hi, just ordered these: 6HM5 EC900 EI Yugoslavia
> Could not find them in the Guide. Are they running on standard  settings or do I need to switch jumpers?
> Thx!


 
 No need to change jumpers if you've been using 6AK5 or other EF95 family tubes.


----------



## Scutey

octavianh said:


> Anyone noticed this new model?
> 
> [size=20.007px]Little Dot MK III SE[/size]
> http://littledot.net/forum/viewtopic.php?f=9&t=10332&sid=3900954372c5dbe339d5faaf0673b1c5


 

 ​This the first I've heard of it. Will be interesting to see if anybody buys one.


----------



## TrollDragon

octavianh said:


> Anyone noticed this new model?
> 
> [size=20.007px]Little Dot MK III SE[/size]
> http://littledot.net/forum/viewtopic.php?f=9&t=10332&sid=3900954372c5dbe339d5faaf0673b1c5


 
 Hey @MIKELAP it has a _*balanced output*_!
  
 Don't say that too loudly as we don't want to drag *you know who* into this thread.


----------



## i luvmusic 2

I don't think if he  still around(in Head-Fi) i haven't see any post from him.


----------



## TrollDragon

i luvmusic 2 said:


> I don't think if he  still around(in Head-Fi) i haven't see any post from him.


 
 Whew, that was close...


----------



## OctavianH

trolldragon said:


> Whew, that was close...


 
 Bringing this to the table, honestly I do not know any big advantage of a balanced output. So please enlighten me.


----------



## TrollDragon

octavianh said:


> Bringing this to the table, honestly I do not know any big advantage of a balanced output. So please enlighten me.


 

 The "balanced output" thing is a long time running joke here on HF across many threads. Whenever balanced was mentioned about an amp or headphone, there was a user who always popped into that thread and professed (to an annoying level) the amazing benefits of balanced...


 For those that don't know about a balanced setup, here is a great explanation.
  
 Quote: headphone.com 





> Balanced-drive delivers a noted increase in audio performance due to the *doubling* of the amp's voltage slew rate and voltage swing range, a reduction of THD (Total Harmonic Distortion) components and the avoidance of crosstalk due to the elimination of the common ground plane.
> 
> The end acoustic result lends an expansive, open-toned quality to the musical presentation with quicker dynamics, more refined detail, tighter low bass and very clearly pronounced mid-ranges.


 
 https://www.headphone.com/pages/balanced-headphones-guide


 I have never dabbled in balanced setup, so I don't have an opinion either way as to the improved audio quality.


----------



## Thenewguy007

Anyone know a alternative to 6H30P-DR tubes for getting stronger bass?

How are the 6N6P/6H6P variation tubes? Is there one that is considered the best?


----------



## MIKELAP

thenewguy007 said:


> Anyone know a alternative to 6H30P-DR tubes for getting stronger bass?
> 
> How are the 6N6P/6H6P variation tubes? Is there one that is considered the best?


 

 ​Using 6SN7 with adapters as power tubes will bring you more bass


----------



## MIKELAP

On Massdrop the new Littledot MK3 SE Balanced : A Hybrid with tube pre-stage $499.99US+ Shipping                                                                                            
  

  

  

  

  
 ​


----------



## i luvmusic 2

^^^
 Really No thanks!
	

	
	
		
		

		
		
	


	




 
  
 I'll take my PIONEER SX-3700(with speaker taps) anytime any day to drive all my Headphones.......


----------



## xuan87

This has been a week of blast from the blast nostalgia. New Future Sonics customs (first customs that I lusted after), and now an update to the MKIII, my first tube amp as well as desktop amp. Lovely amp from my memory, I always wanted to get the MKIV after selling the MKIII but never got around to it.
  
 The MKIII SE looks interesting, a hybrid design with Class A, as well as balanced.


----------



## gulakpi

From what I see, this new MK3SE amp uses 6DJ8 as drivers, and has a full balanced discrete transistor power stage.
 It is, in my opinion, it is closer to the LD Mk8, but at a lower price, more than the Mk3.
  
 The only reason for naming this as the Mk3SE, is probably the aesthetic and size.
 It is priced quite close to the Mk4SE, so it can be a difficult choice for us.
 If I have low-Z cans or opting for balanced operation , this can be a better choice, or the Mk4SE is more interesting (more tube rolling)
 Let's wait to see if the sound quality reviews are favorable......


----------



## gibosi

gulakpi said:


> From what I see, this new MK3SE amp uses 6DJ8 as drivers, and has a full balanced discrete transistor power stage.
> It is, in my opinion, it is closer to the LD Mk8, but at a lower price, more than the Mk3.
> 
> The only reason for naming this as the Mk3SE, is probably the aesthetic and size.
> ...


 
  
 Another reason to choose this is the use of 6DJ8. In terms of audio, these are much better than the 6AK5. But then, they are considerably more expensive too.


----------



## Pinoyjaa

This is an awesome thread. Thanks DoA for the extensive review and for starting this thread. I am a newbie on tube rolling, and this is a gold mine. I just ordered my first LD mkII with the upgraded tubes based on this review.


----------



## xuan87

gulakpi said:


> From what I see, this new MK3SE amp uses 6DJ8 as drivers, and has a full balanced discrete transistor power stage.
> It is, in my opinion, it is closer to the LD Mk8, but at a lower price, more than the Mk3.
> 
> The only reason for naming this as the Mk3SE, is probably the aesthetic and size.
> ...


 
  


gibosi said:


> Another reason to choose this is the use of 6DJ8. In terms of audio, these are much better than the 6AK5. But then, they are considerably more expensive too.


 
  
 Thanks both for the clarification.
  
 Always a struggle for me: The MKIII SE will probably be a better fit for me right now given that I'm gravitating towards a SS and neutral setup, but on the other hand, the MKIV will provide a nice change in sound and add some variety to my setup. 
  
 However, probably won't get either one in the near future; loads other more interesting stuff to get.


----------



## dc430

Thank you for this great guide, bought a pair of M8100 yesterday and started my first ever tube rolling section, the MK3 is so much better sounding with my HE400i. Bought both around black Friday last year, wasn't impressed but after changing into those M8100 I can't get them off.


----------



## Scutey

dc430 said:


> Thank you for this great guide, bought a pair of M8100 yesterday and started my first ever tube rolling section, the MK3 is so much better sounding with my HE400i. Bought both around black Friday last year, wasn't impressed but after changing into those M8100 I can't get them off.


 

 ​They are a great sounding tube and one of my favs, more of a fun sound than the EF type92,  M8161.


----------



## MIKELAP

Quote: 





dc430 said:


> Thank you for this great guide, bought a pair of M8100 yesterday and started my first ever tube rolling section, the MK3 is so much better sounding with my HE400i. Bought both around black Friday last year, wasn't impressed but after changing into those M8100 I can't get them off.


 

 ​Here are more tube rolling options most tubes on that page you can get for little money page 77 post #1154 and also this page 585 post# 8766 and 8767


----------



## OctavianH

Tomorrow I will receive my 6N6P-IR power tubes. But before that, I read something related to the difference between 6N6P and them. It seems 6N6P need 750mA and 6N6P-IR need more, 900mA.
 I am sure these work fine on the MK3 which does not get as hot as the MK2 but can anyone confirm me that on MK2 these tubes are not creating any problems? I think about the circuitry and heat which might decrease lifetime or create other problems.


----------



## Scutey

octavianh said:


> Tomorrow I will receive my 6N6P-IR power tubes. But before that, I read something related to the difference between 6N6P and them. It seems 6N6P need 750mA and 6N6P-IR need more, 900mA.
> I am sure these work fine on the MK3 which does not get as hot as the MK2 but can anyone confirm me that on MK2 these tubes are not creating any problems? I think about the circuitry and heat which might decrease lifetime or create other problems.


 
  
 Hi OctavianH,
  
 One of the power tubes mentioned in the mk2 user manual is the 6N6P-I which also has a 900mA heater current so you shouldn't have trouble with the 6N6P-IR, (but I stand to be corrected) Little Dot i'm guessing would have tested the mk2 with the higher current power tubes so the components should be able to take the extra heat.


----------



## OctavianH

I think you are right, I am worrying too much. In the meantime I made a spreadsheet with a comparison of the specs of MK2,3 and 4:
https://docs.google.com/spreadsheets/d/1KoAQwmx_JDGqV4L5PpufFsREhiESPU8ZiSRvmVyj-Q0/edit?usp=sharing
 If anyone is interested, just click on it. What I wanted to find out is the difference between the models in a more simple way (than just open each one's spec sheet). Link is public via Google Drive, and 2 remarks: dimensions are EU metric and price is the "worldwide" price from Little dot website.


----------



## Scutey

octavianh said:


> I think you are right, I am worrying too much. In the meantime I made a spreadsheet with a comparison of the specs of MK2,3 and 4:
> https://docs.google.com/spreadsheets/d/1KoAQwmx_JDGqV4L5PpufFsREhiESPU8ZiSRvmVyj-Q0/edit?usp=sharing
> If anyone is interested, just click on it. What I wanted to find out is the difference between the models in a more simple way (than just open each one's spec sheet). Link is public via Google Drive, and 2 remarks: dimensions are EU metric and price is the "worldwide" price from Little dot website.


 

 ​Well I was the same with the EH6H30PI, no harm in asking!, nice work with the comparison spreadsheet.


----------



## OctavianH

scutey said:


> ​Well I was the same with the EH6H30PI, no harm in asking!, nice work with the comparison spreadsheet.


 
 I see that people are apreciating it, so I will continue to improve it. I could not see anywhere in the internet a centralized version.
 My conclusion is that MK 2,3 and 4 are basicly the same amp with 90% of the same specs but different quality components and stock tubes.
 What was interesting for me was to see that only on MK2 they are specifying Max Input Voltage of 4V RMS. This is interesting since I ordered a Chord 2Qute to use with this amp and it has 3V on line out. I thought to order a 2Qute + MCRU power supply until GB goes out of EU and shipment might become more complicated for me. Impressions related to my new Chord + Littledot family will follow.


----------



## Riddick

Mullard 8100's arrived today...
 After some time burning in the Voskhod's for 70h,
 I decided to give the Mullard's their try...
 Out of the Box I think hear they fit a bit much better with the Beyerdynamic T90.
 I'm not afraid to leave the volume knob alone, anymore...
  
 I'm afraid the Tube rolling bug got me, next some 6H30 Power Tubes, maybe?!


----------



## gulakpi

octavianh said:


> I think you are right, I am worrying too much. In the meantime I made a spreadsheet with a comparison of the specs of MK2,3 and 4:
> https://docs.google.com/spreadsheets/d/1KoAQwmx_JDGqV4L5PpufFsREhiESPU8ZiSRvmVyj-Q0/edit?usp=sharing
> If anyone is interested, just click on it. What I wanted to find out is the difference between the models in a more simple way (than just open each one's spec sheet). Link is public via Google Drive, and 2 remarks: dimensions are EU metric and price is the "worldwide" price from Little dot website.


 
 Nice Job!  Thank you!


----------



## HungryPanda

@OctavianH great spreadsheet, thanks for uploading it.


----------



## Scutey

riddick said:


> Mullard 8100's arrived today...
> After some time burning in the Voskhod's for 70h,
> I decided to give the Mullard's their try...
> Out of the Box I think hear they fit a bit much better with the Beyerdynamic T90.
> ...


 

 ​Join the club Riddick!, I think we have all been bitten by the tube rolling bug!, seems to come with buying a tube amp!.
  
 The M8100 is a great sounding tube, I like for it's fun sound and pumping bass, the 6H30 power tubes should go quite well with the M8100 and the T90, another slightly cheaper option and, if anything slightly better sounding is the 6N6-IR, that might work with your set up.


----------



## Scutey

octavianh said:


> I see that people are apreciating it, so I will continue to improve it. I could not see anywhere in the internet a centralized version.
> My conclusion is that MK 2,3 and 4 are basicly the same amp with 90% of the same specs but different quality components and stock tubes.
> What was interesting for me was to see that only on MK2 they are specifying Max Input Voltage of 4V RMS. This is interesting since I ordered a Chord 2Qute to use with this amp and it has 3V on line out. I thought to order a 2Qute + MCRU power supply until GB goes out of EU and shipment might become more complicated for me. Impressions related to my new Chord + Littledot family will follow.


 

 ​What you've done is make it easier for anyone thinking of getting a LD who has more than one of them in mind, I think you'll find a lot of people using it in future. 
  
 Btw have your 6N6P-IR arrived yet?.


----------



## OctavianH

scutey said:


> ​What you've done is make it easier for anyone thinking of getting a LD who has more than one of them in mind, I think you'll find a lot of people using it in future.
> 
> Btw have your 6N6P-IR arrived yet?.


 
  
 Yes, they are at the Postal Office but today I didn't had time to go and get them. I plan this to happen tomorrow morning.
 I ordered 4x6N6P-IR and 4xVoskhods... just to have some more


----------



## Scutey

octavianh said:


> Yes, they are at the Postal Office but today I didn't had time to go and get them. I plan this to happen tomorrow morning.
> I ordered 4x6N6P-IR and 4xVoskhods... just to have some more


 

 ​Well I will be interested to hear what you think, hope you enjoy them!.


----------



## OctavianH

scutey said:


> ​Well I will be interested to hear what you think, hope you enjoy them!.


 
 I really look forward. I expect also some 6HM5 to arrive sometime next week. And tomorrow I might receive the Chord DAC, so maybe that one wil be an improvement in the source and the 6N6P-IR + Voskhod and Chord will be the winning triple. We will see.


----------



## Scutey

octavianh said:


> I really look forward. I expect also some 6HM5 to arrive sometime next week. And tomorrow I might receive the Chord DAC, so maybe that one wil be an improvement in the source and the 6N6P-IR + Voskhod and Chord will be the winning triple. We will see.


 

 ​Sounds like you're going to be having some fun with your new gear, the Chord dac should do a good job for you, those 6HM5 are pretty damn fine tubes, for me, they are the best driver tubes for the LD, without resorting to adapters for the C3G, they are in my LD now with the 6n6p-ir, rocking out to some wicked tunes .


----------



## Riddick

> Originally Posted by *Scutey* /img/forum/go_quote.gif
> 
> ​Join the club Riddick!, I think we have all been bitten by the tube rolling bug!, seems to come with buying a tube amp!.
> 
> The M8100 is a great sounding tube, I like for it's fun sound and pumping bass, the 6H30 power tubes should go quite well with the M8100 and the T90, another slightly cheaper option and, if anything slightly better sounding is the 6N6-IR, that might work with your set up.


 
  
 I already have the 6N6P-i as power tubes.
 You said the 6N6P-ir are more laid back than the 6N6P-i, right?
  
 If so, I will try to get some...
  
 I'm loving the Mullard's so far. The Highs are tamed but lush. They give a bit more punch. Overall a more "organic" sound. They go really well with the Beyer's...
  
 I've some 6HM5 EC900 EI Yugoslavia on the way,too. What do think about these? Got them quite cheap to give them a try...
  
 Any other suggestions for Power Tubes?


----------



## Scutey

riddick said:


> I already have the 6N6P-i as power tubes.
> You said the 6N6P-ir are more laid back than the 6N6P-i, right?
> 
> If so, I will try to get some...
> ...


 

 ​No, it was the 6N6P that are a bit more laid back (slightly warmer),it's the 6N6P-IR, they are just a bit more dynamic, slightly cooler, a bit more detail and attack, we are only talking small amounts btw, not a night and day difference, imo they are the best of the 6n6 type, not including the 6H30DR which I doubt I will ever try!.
  
 Those 6HM5 are a great tube, musical, detailed, good tight base, good soundstage and dead quiet, again just my opinion of course but, apart from the C3G (expensive) the best tube you can get for the LD, another worth trying the M8161, and although I've not tried it myself the tung sol gets a lot of love on Head-Fi, another cheap option is the GE JAN5654W. Hope this helps


----------



## Whelkie D

octavianh said:


> I really look forward. I expect also some 6HM5 to arrive sometime next week. And tomorrow I might receive the Chord DAC, so maybe that one wil be an improvement in the source and the 6N6P-IR + Voskhod and Chord will be the winning triple. We will see.


 
 Good choice. I have some 6HM5 + 6N6P-IR in at the moment and this is the best combination I've come across (so far!).  It seems to be the best of both worlds - the warmth you get with Mullards with the clarity of Voskhods.


----------



## OctavianH

Good morning gents,
  
 I just received a new shipment of "tubes", "valves" or however you want to call them.
 The complete order was 4 x 6N6P-IR + 4 x Voskhod 6J1P-EV and the sum including shipment was 70EUR.
 I say it is a decent price.
  
 What I have received are some Voshkods from '73 and 6N6P-IR from 88:

  
 The complete package:

  
 Any comments related to the manufacturing years? I did not had time to try them but my currently used Voskhods are from '79 and the 6N6P from '85.
 I will test them during the weekend and inform about any findings, impressions and so on.
  
 Later Edit: First impression of the "IR" power tubes is that they are "cooler" but more precise. So less bass but somehow better defined. I guess I need to wait for some "burn in" here. The overall sound is more metalic, at least when listening to Judas Priest's Painkiller which is one of may favourite tests for drums and stuff like that.


----------



## Scutey

octavianh said:


> Good morning gents,
> 
> I just received a new shipment of "tubes", "valves" or however you want to call them.
> The complete order was 4 x 6N6P-IR + 4 x Voskhod 6J1P-EV and the sum including shipment was 70EUR.
> ...


 

 Hi OctavianH,
  
 Glad to see you've got your valves/tubes, I would say your first impression of the IR's is spot on, I think they work very well with the 6HM5.
  
 As for the manufacturing years, the consensus for the Voskhods seems to pre 1980 are better, as for the IR I think they were an update of the 6N6P-I so I don't think you will see pre 1980 for them so probably 1980's are best.


----------



## OctavianH

Ok, I understand.  I just receive my Chord 2 Qute.
  

  
 Now trying to figure out about Chord - Littledot - tubes pairing.


----------



## Flex2d

Hey JohnnySound,
 I final got a DAC to go with my LD mk2. I went  with a SMSL Sanskrit to see how it is.. only been running it for 30 mins  and have to say the sound is more beefier if that makes sense. Bass is maybe fuller and maybe  more crowded ... Maybe not so much space in the music. Kind of waiting to see if that sound will settle down but not sure. I looked at the Z review guy on youtube and reddit regarding this and he seems to think its good... whats your thoughts.
 The sound is also a lot louder for some reason . Not sure how as the dac doesn't have any amplification?!.. 
  
 Should i keep this dac or wait a month till next paycheck and get a m6/m8 ..
  
 Not sure, any advice from yourself or anyone with knowledge in this area, would be great.
  
 edit: seems the separation isn't great.. My motherboard is is x99a ack 9 MSI.. not sure  sounds is fuller and not such clear separation. could be i'm used to worse DAC lol
  
 edit: using optical output @24Bit 192k
  
  
 Edit again: Returned as faulty.. not getting an SMSL agian
 Thanks
  
 Daniel


----------



## perfect-pitch

Hello guys. I am selling some nice upgrade tubes for Little Dot MK III. If you are interested please look at the for sale section.


----------



## MPH91

Hey guys, how important is it for the power tubes to be matched? I've ordered a Little Dot MK II and I'm currently considering to buy a pair of 6N6P from ebay. However they don't seem to be matched, so should I go for them or is it better to look for a matched pair?


----------



## Scutey

mph91 said:


> Hey guys, how important is it for the power tubes to be matched? I've ordered a Little Dot MK II and I'm currently considering to buy a pair of 6N6P from ebay. However they don't seem to be matched, so should I go for them or is it better to look for a matched pair?


 
  
  


trolldragon said:


> Power tubes is a bit of a misnomer, the LD amplifiers are really just preamps.
> 
> The matching of power tubes is required in Push/Pull configurations where both tubes are required to draw the same amount of current. The output tubes of the LD amps are configured in a Cathode Follower configuration and tube matching is not required


 
 Hi MPH91
  
 This is the reply I received when I asked the same question.


----------



## MPH91

Thanks very much!
  
 http://www.ebay.de/itm/6N6P-E182CC-2-Stk-2-pcs-USSR-Elektronenroehren-Radioroehre-Goldgitter-/182473848803
  
 Does anybody have an opinion on those? Should I buy them or is it better to look for a different pair? Sorry for all those questions but I'm new to the whole tube rolling thing.
  
 Edit: Alright forget about it guys I didn't get it anyway


----------



## Scutey

mph91 said:


> Thanks very much!
> 
> http://www.ebay.de/itm/6N6P-E182CC-2-Stk-2-pcs-USSR-Elektronenroehren-Radioroehre-Goldgitter-/182473848803
> 
> ...


 
 Hi there MPH91, the 6N6P is a decent power tube, others worth considering are the 6N6P-I and the 6N6P-IR, the latter two have the edge sound wise, but if cost is a consideration then the 6N6P is a bit cheaper. Here is a link to another ebay sale if you are still interested the the 6N6P.
  
 http://www.ebay.com/itm/6N6P-ECC99-E182CC-Novosibirsk-Tubes-GOLD-grid-Lot-of-2-Pcs/272492040874?_trksid=p2047675.c100005.m1851&_trkparms=aid%3D222007%26algo%3DSIC.MBE%26ao%3D2%26asc%3D41669%26meid%3D4d9514a9848d4a93b78636ec7c028930%26pid%3D100005%26rk%3D5%26rkt%3D6%26sd%3D322402779820


----------



## MPH91

scutey said:


> Hi there MPH91, the 6N6P is a decent power tube, others worth considering are the 6N6P-I and the 6N6P-IR, the latter two have the edge sound wise, but if cost is a consideration then the 6N6P is a bit cheaper. Here is a link to another ebay sale if you are still interested the the 6N6P.
> 
> http://www.ebay.com/itm/6N6P-ECC99-E182CC-Novosibirsk-Tubes-GOLD-grid-Lot-of-2-Pcs/272492040874?_trksid=p2047675.c100005.m1851&_trkparms=aid%3D222007%26algo%3DSIC.MBE%26ao%3D2%26asc%3D41669%26meid%3D4d9514a9848d4a93b78636ec7c028930%26pid%3D100005%26rk%3D5%26rkt%3D6%26sd%3D322402779820


 

 Thank you very much for the info!
 I'm currently also considering to upgrade the driver tubes but I'm not sure weather to get the Voshkod 6ZH1P or the Mullard M8100/CV4010. I like a warmer sound signature and the Mullards seem to have a slight bass advantage however many people here seem to rave about the Voshkods. Are there any other facts to consider when deciding between these two? And would any of them match better with the 6N6P?


----------



## OctavianH

Well, it seems my setup is final: added MCRU linear power supply for 2Qute. It looks like a studio, but this is life, I need a lot of stuff to be happy.
  

  
 And yes, 2Qute + MCRU kicks major ass. By far my best setup using Voshkod 6J1P-EV + 6N6P-IR. Quite neutral and clear sound. 
 I will do only 1 change from now on, try the 6HM5 when they arrive.


----------



## Whelkie D

mph91 said:


> I like a warmer sound signature and the Mullards seem to have a slight bass advantage however many people here seem to rave about the Voshkods.


 
 I find the Mullards have a much warmer sound than the Voskhods. Perhaps the Voskhods have a touch more detail on the highs but for warmth the Mullards can't be beaten


----------



## MPH91

Next question:
  
 Is there a difference in sound between square getter and ring getter? As far as I found out the getters themselves don't have an effect on the sound but they affect other things that do. So has anyone an opinion on which getter shape sound better for Mullards?


----------



## Scutey

mph91 said:


> Thank you very much for the info!
> I'm currently also considering to upgrade the driver tubes but I'm not sure weather to get the Voshkod 6ZH1P or the Mullard M8100/CV4010. I like a warmer sound signature and the Mullards seem to have a slight bass advantage however many people here seem to rave about the Voshkods. Are there any other facts to consider when deciding between these two? And would any of them match better with the 6N6P?


 
 If you like a warmer sound the Mullard M8100 might be a better bet, both are good tubes, the M8100 has a smooth detailed midrange, quite warm, powerfull bass and good extended highs. the Voskhod is cooler/drier, nicely detailed, good strong bass, good detailed highs, both are mill spec so are very sturdy and should last, just my opinion of course but of the two I prefer the M8100, for me it has a fun sound, although many prefer the Voskhod, the 6N6P is on the warmish side and will pair well with the M8100, also with the Voskhod, as it might take the edge off the cooler sound.


----------



## Scutey

octavianh said:


> Well, it seems my setup is final: added MCRU linear power supply for 2Qute. It looks like a studio, but this is life, I need a lot of stuff to be happy.
> 
> 
> 
> ...


 
 Nice set up you have there!.


----------



## gibosi

mph91 said:


> Is there a difference in sound between square getter and ring getter? As far as I found out the getters themselves don't have an effect on the sound but they affect other things that do. So has anyone an opinion on which getter shape sound better for Mullards?


 
  
 True, the getters themselves have no effect on the sound. And further, they have no effect on other things that do.
  
 For those of us who collect tubes, the primary importance of the getter shape is that it provides an important clue as to when the tube was manufactured. For example, halo getters were first introduced in the late 1950's, and became common in the 1960's and into the 1970's. And therefore, a Mullard M8100 with halo getters was likely manufactured in the 1960's, or later. Prior to that, Mullard M8100's had rectangular getters.
  
 So your question could be rephrased:  Do the older Mullard M8100 from the 1950's sound better than the newer ones?
  
 (And as I haven't listened to those tubes in a several years, I will leave it to others to jump in here....)


----------



## Riddick

scutey said:


> If you like a warmer sound the Mullard M8100 might be a better bet, both are good tubes, the M8100 has a smooth detailed midrange, quite warm, powerfull bass and good extended highs. the Voskhod is cooler/drier, nicely detailed, good strong bass, good detailed highs, both are mill spec so are very sturdy and should last, just my opinion of course but of the two I prefer the M8100, for me it has a fun sound, although many prefer the Voskhod, the 6N6P is on the warmish side and will pair well with the M8100, also with the Voskhod, as it might take the edge off the cooler sound.


 

 You hit the nail on the head there.


----------



## Scutey

riddick said:


> You hit the nail on the head there.


 

 ​Thanks!, other opinions, are of course, available!.


----------



## OctavianH

I avoid making recommendations because I am a novice learning from others here. But recently I tried several pair of tubes and also exchanged several DAC models, in my quest to find best possible sound for rock music. My reference, in my memory, was an old tape analog system I previously owned as a child (more exactly my father's equipment) which remained in my mind as the best possible sound system. Most probably this was placebo. I cannot remember exactly what model was the amplifier or the other components, because it was a tower system formed by 3-4 pieces, the only thing I remember is that I used at that time some Panasonic headphones. That one was for me the analogue and perfect sound which made me discover the music.
 Ok, why I am telling this in this thread is because of my recently tests and listening sessions, and I have spent some time for this, I observed how important is also the source and headphones in the whole equation. Reading the posts related to 6N6P and Voskhod, which I own, I have to say the following:
 - Voskhod + 6N6P sounded good on T5p Beyers, but not perfect
 - when changing with T1.2 the same setup had too much bass
 - when changing drivers to M8161 it was more refined and classy somehow but bass increased and mids somehow were too laid back
 - when putting back Voskhods + 6N6P-IR the extra bass disappeared, the mids problem was solved but I felt that I need more bass and somehow the sound is missing something
 - the miracle happened when changing the DAC with Chord 2Qute which made my music sound somehow on fast forward, more detail and speed which were essential ingredients for my recipe
 - and in the end, adding a MCRU Linear Power Supply of app 200EUR to this DAC made a really incredible turn, I have to say that the missing bass is gone, sound is much more powerfull and somehow better defined, the overall sound increased a lot.
  
 So conclusions to my story are, each one has to follow his own path because of the rest of the line, cables and power sources make difference even if a lot of people claim they are not, and the best improvement for me was a power supply. 6N6P + Voskhod can sound very different on different setups only if you change a power supply. Ok, lesson learned, my quest is over.


----------



## Scutey

octavianh said:


> I avoid making recommendations because I am a novice learning from others here. But recently I tried several pair of tubes and also exchanged several DAC models, in my quest to find best possible sound for rock music. My reference, in my memory, was an old tape analog system I previously owned as a child (more exactly my father's equipment) which remained in my mind as the best possible sound system. Most probably this was placebo. I cannot remember exactly what model was the amplifier or the other components, because it was a tower system formed by 3-4 pieces, the only thing I remember is that I used at that time some Panasonic headphones. That one was for me the analogue and perfect sound which made me discover the music.
> Ok, why I am telling this in this thread is because of my recently tests and listening sessions, and I have spent some time for this, I observed how important is also the source and headphones in the whole equation. Reading the posts related to 6N6P and Voskhod, which I own, I have to say the following:
> - Voskhod + 6N6P sounded good on T5p Beyers, but not perfect
> - when changing with T1.2 the same setup had too much bass
> ...


 

 ​Very well put OctavianH. Ive been a member of Head-Fi for 5 years and it's only in the last few months that I've felt able to and give my experiences/opinions,  after  reading  and picking up tips, recommendations etc from various threads and then acting on them, which, in turn has given me the confidence to share those experiences, in the end, as you say, it's all about how we act on what is on here. It's good to hear that you've finally found a set up that works for you, fortunately for me I have now find my own ideal set up, two in fact!, it's taken a while to get there, and a fair amount of money as well, but above all, it's been very enjoyable, and rewarding.


----------



## MIKELAP

Hey guys if any of you are looking for a bundle of 2-C3G and 3- rare C3GS tubes make me an offer in the for sale thread .Thanks                                                                                                     http://www.head-fi.org/t/839887/1-pair-siemens-c3g-and-3-siemens-c3gs


----------



## lglions

mikelap said:


> Hey guys if any of you are looking for a bundle of 2-C3G and 3- rare C3GS tubes make me an offer in the for sale thread .Thanks                                                                                                     http://www.head-fi.org/t/839887/1-pair-siemens-c3g-and-3-siemens-c3gs


 
 They went fast


----------



## lglions

Speaking of C3Gs - haven't seen them from this manufacturer:

 If anyone keen to try (I have several pairs already of C3Gs from Telefunken and Siemens):
 http://www.ebay.com/itm/2-NOS-tubes-Valvo-C3g-72-60-matched-100-/112313671313


----------



## gibosi

lglions said:


> Speaking of C3Gs - haven't seen them from this manufacturer:


 
  
 From my experience, and that of others, all C3g with whilte silkscreened logos and text on shiny-black cans were manufactured in the 1970's by Siemens. In the 1950's and 60's, both Lorenz and Siemens manufactured this tube, characterized by flat-black cans and embossed logos. And I am fairly sure that Telefunken also manufactured this tube during that time, with similar flat-black cans and embossed logos, but they would appear to be very rare.
  
 While I can't be positive, I seriously doubt that Valvo ever manufactured this tube. They simply rebranded tubes sourced from Siemens.


----------



## Scutey

​Just got a NOS pair of those Valvo C3G's from the same seller, burning them in now.


----------



## MIKELAP

If you own a Littledot 1+MK2,MK3,MK4,MK4SE maybe you would possibly need some of these, priced to sell .Thanks                                                                                                                                   http://www.head-fi.org/t/840068/tubes-compatible-with-littledot-1-mk2-mk3-mk4-mk4se-for-sale


----------



## MIKELAP

If anyone is Interested in Ei 6HM5 tall bottles i have 2 pairs and a single tube to sell  also have a pair of ribbed Voskhod 6ZHIP-EV and lots more .pm me if interested  check out my ad in the For Sale section .Thanks


----------



## pichu

Any opinion on the Novoisbirsk power tubes? I just picked them up and they sound pretty good so far! Am i crazy to say i feel like i got more soundstage by rolling these guys in over the stock power tubes?


----------



## Scutey

pichu said:


> Any opinion on the Novoisbirsk power tubes? I just picked them up and they sound pretty good so far! Am i crazy to say i feel like i got more soundstage by rolling these guys in over the stock power tubes?


 
 Hi pichu

 No you're not crazy!. By Novosibirsk I assume you mean the 6n6p?, in which case you have a good power tube, I find them to have a warmer, more of a fun sound with powerful bass, there is a general consensus that the 6n6p-ir has the edge sonically but only by a small amount. But IMO there is nothing wrong with the 6n6p.


----------



## gulakpi

scutey said:


> Hi pichu
> 
> No you're not crazy!. By Novosibirsk I assume you mean the 6n6p?, in which case you have a good power tube, I find them to have a warmer, more of a fun sound with powerful bass, there is a general consensus that the 6n6p-ir has the edge sonically but only by a small amount. But IMO there is nothing wrong with the 6n6p.


 
 Hello Scutey,
 From the pictures you posted, you've been using 6SN7 as power tubes on your LD.  
 I'm also using a pair of PSvane 6SN7UK too. 
 Will you share your experience with your 6SN7 rolling?


----------



## lglions

gulakpi said:


> Hello Scutey,
> From the pictures you posted, you've been using 6SN7 as power tubes on your LD.
> I'm also using a pair of PSvane 6SN7UK too.
> Will you share your experience with your 6SN7 rolling?


 
 Not Scutey, but I tried 6SN7s in my LD MK3.
  
 Liked them with high impedance HPs (tried with 600 Ohm Beyers). And they didn't work with low impedance HPs (clear sound deformation, rattling etc. on Oppo and Fostex). I tried two sets of 6SN7s.
  
 So I shelved them and now use 6n6p-ir. The best power tube for my ears.


----------



## Scutey

gulakpi said:


> Hello Scutey,
> From the pictures you posted, you've been using 6SN7 as power tubes on your LD.
> I'm also using a pair of PSvane 6SN7UK too.
> Will you share your experience with your 6SN7 rolling?


 

 ​Hi gulakpi,
  
 Yes I have been using 3 sets of different 6SN7's the Electro Harmonix 6SN7, Philips JAN6SN7WGTA,  and PSVANE UK-6SN7, my experience has been that it is a more linear, more refined than 6N6P and IR, I would say more clarity/detail with good soundstage, one thing I have noticed, maybe this is just my experience but they seem to be less forgiving, more revealing of older, or poorer recordings than the 6N6 type.
  
 Of my 3 sets I would say the Philips JAN is the most audiophile, a tad cool, detailed highs and mids, with decent but not powerful bass, I found these to be very good with classical, acoustic, and some rock, the PSVANE a bit warmer, smooth high's, for me, don't extend quite as much as the Philips, smooth mids, a touch less detail, but more airy, and just a tad more in the bass, the Electro Harmonix is the most fun sounding, closest sounding to the 6N6P and IR, a bit rougher round the edges than the other two, highs can be a bit too extended, good fairly detailed mids and the most powerful bass of the three, I find these the best for rock/metal or anything more aggressive/fast.
  
 Although I do like the 6SN7 for the last week i've been back on the 6N6P-IR and I have to say sonically, for me at least there is very little difference, what they lack in a tad less refinement they make up for with having a more energetic fun sound, which I think I prefer, they're also, at least what I listen to a bit more forgiving of some recordings over the 6SN7, so if you're after the extra refinement, more audiophile sound then I think the 6SN7 is the way to go, especially paired with either the C3G, or the EI 6HM5, if not then you can't go too far wrong with the 6N6P-IR, or even the 6N6P, please bear in mind that this is just my opinion, for what it's worth! .


----------



## gulakpi

Thank you Iglions and Scutey,
  
 My Mk 4 came with a pair of EH 6H30Pi.
 I've been rolling many driver tubes as suggested on this thread and have been enjoying the process!
 For power tubes, I only have the (stock) 6H30Pi and 2 pairs of 6SN7 I have on hand.  One pair is the PSVane UK-6SN7 and the other is Russian 6N8P. The PSVane sounds a tad better in the mid and is a bit more airy than the Russian 6N8P.
 As you have mentioned, the PSVane sounds silky smooth on my 300 ohm Senns, but I have serious distortions heard on my other 62 ohm AKGs (K702 and K550), which I like much.  I would like to find out if any other 6SN7's have better results when used on low-Z cans, and it was just my 2 pairs.
  
 Thanks for the reply!   I have not tried the 6N6P/ir tubes yet and for sure I will get some to try and see if they are better than the 6H30Pi, which I think have 2000+ hours already.  Time to try new tubes!  
  
 For driver tubes, my preference is still the C3g and 6HM5, and the M8100.  I already have more than a dozen sets of driver tubes. I do find the JAN 5654 stock tubes are not bad at all.  I'm waiting for the last components to build my 6DJ8/12AX7 adapters.  I will post photos when its ready!


----------



## pichu

Currently the only driver tubes ive rolled into are the Jan 5654w, if i were only to pick up another driver tube ( finance/budget issues ), what should i pick up?


----------



## gibosi

gulakpi said:


> I would like to find out if any other 6SN7's have better results when used on low-Z cans, and it was just my 2 pairs.


 
  
 I doubt it...
  
 Low-Z cans, especially inefficient low-Z cans, require a lot of current. And the 6SN7 simply isn't up to the job. While not a perfect predictor, the amount of required heater current often correlates pretty well with the amount of DC current the tube can provide to the headphone driver.
  
 The 6SN7 draws 0.6A whereas the 6H30Pi draws 0.9A. By comparison, a 6AS7 draws 2.5A. making it the tube of choice for many OTL designs. And in a very few amps, the 6336 and 6528, which draw 5.0A, are able to drive low-Z cans with considerable authority.
  
 However, the LD is limited to about 1.0A of heater current. And even with the use of an external heater power supply, the amount of DC current running through a 6AS7 may well overheat the internal circuitry of the LD, so this is not something I would encourage.
  
 In addition to tubes like the 6H30, you might want to consider the 5687 and 7044, both of which draw 0.9A. These will do a better job than the 6SN7 with low-Z cans, similar to the 6H30, but also require pin-adapters.


----------



## gulakpi

Thank you much for clarifying this Gibosi!
  
 I guess I will use my PSVane 6SN7 for my Senns, and replace my tired 6H30Pi with some 6N6P-ir when I want to use my AKGs.
 I will try to roll some other 6SN7 too, just to find out if this makes any differences.  I just like the look (and sound as well) of the PSVane coke bottles!


----------



## Scutey

If you want to try another, the EI 6HM5 is very good, and cheap too!.


----------



## OctavianH

My Yugoslavia 6HM5 arrived yesterday. Compared to the Voskhods they are a little bit bigger. But no year on them, only "YUGOSLAVIA 6HM5". So that's it. Since they were cheap I bought 6 pieces but I cannot tell when I will try them, since my current setup seems perfect.


----------



## Scutey

octavianh said:


> My Yugoslavia 6HM5 arrived yesterday. Compared to the Voskhods they are a little bit bigger. But no year on them, only "YUGOSLAVIA 6HM5". So that's it. Since they were cheap I bought 6 pieces but I cannot tell when I will try them, since my current setup seems perfect.


 

 ​I think they were mostly made in the 80's, mostly for military use.


----------



## lglions

octavianh said:


> My Yugoslavia 6HM5 arrived yesterday. Compared to the Voskhods they are a little bit bigger. But no year on them, only "YUGOSLAVIA 6HM5". So that's it. Since they were cheap I bought 6 pieces but I cannot tell when I will try them, since my current setup seems perfect.


 
 I believe these tubes would've won or tied "Best Value" award for LD amp. But as of "Best Overall" - I don't think the'd be at the top.


----------



## i luvmusic 2

Anyone remember this tube?I can't remember what it's called.THANKS!


----------



## MIKELAP

i luvmusic 2 said:


> Anyone remember this tube?I can't remember what it's called.THANKS!


 
 mordy played with those tubes


----------



## i luvmusic 2

I recall few of us tried this tube i think TD have this one too i just can't remember what it's called.


----------



## gibosi

I am pretty sure it is a 6832. These were manufactured by Raytheon.


----------



## i luvmusic 2

gibosi said:


> I am pretty sure it is a 6832. These were manufactured by Raytheon.


 
 THANK YOU VERY MUCH!


----------



## i luvmusic 2

Here it is that tube being used........


----------



## MIKELAP

the 7963 mordy was trying was a Sylvania


----------



## gibosi

To my mind, the Sylvania 7963 was the best of the sub-miniatures I tried, but the Raytheon 6832 was a close second, stuffed into an octal base.


----------



## i luvmusic 2

Now that brings back the good ole days...........


----------



## TrollDragon

i luvmusic 2 said:


> I recall few of us tried this tube i think TD have this one too i just can't remember what it's called.


 
 We played with the Raytheon 6832 like Gibosi said earlier.

 Literally a great little tube!


----------



## i luvmusic 2

^^^^ WOW!That is one good looking 6832 adapter.
 Mine is like so for the CRACK.


----------



## Gezzaman

apart from aesthetics, is there any point in upgrading my modded MK3 using the C3g and 6AS7G to a MK4 to use the same tubes?


----------



## i luvmusic 2

IMO no the two amps are pretty much the same.


----------



## Pinoyjaa

My LD mkII amp just arrived today. Plugged it in and I have been listening for the last 4 hours. Awesome, better than the Bravo Audio amp that I have been using for the last two years. I am ready to try tube rolling. Any recommendations on the first tube I should try?


----------



## Gezzaman

Page 1 is a good place to start off..


----------



## OctavianH

pinoyjaa said:


> My LD mkII amp just arrived today. Plugged it in and I have been listening for the last 4 hours. Awesome, better than the Bravo Audio amp that I have been using for the last two years. I am ready to try tube rolling. Any recommendations on the first tube I should try?


 
 People around here are using:
 1) power tubes: 6N6P (warmer) or 6N6P-IR (colder but more refined)
 2) driver tubes:
 a) EF92 (do not forget to set internal jumpers to EF92) - Mullard 8161 (detailed)
 b) EF95 (no setting needed since default jumpers are set for EF95) - Mullard 8100 (warm), Voshkod 6ZH1P-EV (detailed, fast) or Yugoslavia 6HM5 (somewhere in the mid of previously mentioned)
  
 These tubes work without other modding or adapters. But the best possible sounding driver tubes, according to many here, are Siemens C3G. But those are expensive and you need some special adapters to use with MK2.
  
 These impressions are specific for everyone. They depend on the DAC, file, Headphones and so on. You need to find your best pair by yourself.
  
 This is a short list. For more details see post 1 of this topic.


----------



## Flex2d

I gotta say i dito the Mullard M8100 and the Yugoslavia 6HM5.
  
 Not impressed with the Voshkod 6ZH1P-EV, bought 3 different variations and just not feeling it from them at all. Haven't run the Mullard 8161 extensively but sound good.
  
 Cheers


----------



## MIKELAP

gezzaman said:


> Page 1 is a good place to start off..


 
 Or page 77 ,and i would start reading from the end 


flex2d said:


> I gotta say i dito the Mullard M8100 and the Yugoslavia 6HM5.
> 
> Not impressed with the Voshkod 6ZH1P-EV, bought 3 different variations and just not feeling it from them at all. Haven't run the Mullard 8161 extensively but sound good.
> 
> Cheers


 
 Your not alone never really liked those  russian tubes


----------



## Pinoyjaa

Thanks for the recommendations on tubes and section of this forum to get info. I will need to do a lot of reading to familiarize myself with tube rolling. Sounds like a fun hobby. What tubes would you recommend for the LD mkII and a pair of sennheiser hd800?


----------



## dobigstuff

Finally have all the pieces in play.  See Below:  (Still need to get some NOS 6SN7's)


----------



## dobigstuff

And the Little Guy......


----------



## OctavianH

What power tubes do you use for c3g? (for MK2/MK3)


----------



## Scutey

octavianh said:


> What power tubes do you use for c3g? (for MK2/MK3)


 

 ​Everything I've used with the c3g's has sounded good, 6n6p/ir , and my 6sn7's, EH, Philips JAN6sn7wgta and PSAVENE UK-6SN7. At the mo I've got hold of some Foton 1965 6n6p and they sound great with them too, my experience so far is that they pair well with most tubes.


----------



## OctavianH

Ok, then maybe in the summer I'll order some of these:
 http://www.ebay.de/itm/2pc-C3G-TO-6AK5-5654-6096-adapter-for-little-dot-MKIII-SE-Headphone-/201366974329?hash=item2ee2682f79:g:ZYUAAOSwu4BVwVN8
  
 At the moment I try to use what I have, because I already have a "stockpile" of tubes and I still haven't tried the 6HM5.
 And again comes in my mind the question: C3G or MK4 or Feliks Audio Elise? And for Feliks I cannot use the "stockpile" so another tube quest is starting and so on. I feel like a hamster trying to keep busy


----------



## output555

Question: I was looking through my collection of tubes and found a pair of Mullard E88CC/01 NOS. Will these work in a Little Dot MkIII?
 Also, how about a pair of Amperex 6DJ8 Bugle Boys?


----------



## MIKELAP

output555 said:


> Question: I was looking through my collection of tubes and found a pair of Mullard E88CC/01 NOS. Will these work in a Little Dot MkIII?
> Also, how about a pair of Amperex 6DJ8 Bugle Boys?


 
 Back in the day I made a couple of 6dj8 adapters and as far as i know there is no ready made adapter adapters on Ebay for use with this tube here's are  the ones i made and the schematic if you want to make one or if your interested in mine send me a pm.if you want to know more about this use the SEARCH FUNCTION atop the page 
  

  
  
  

  
 .


----------



## Scutey

octavianh said:


> Ok, then maybe in the summer I'll order some of these:
> http://www.ebay.de/itm/2pc-C3G-TO-6AK5-5654-6096-adapter-for-little-dot-MKIII-SE-Headphone-/201366974329?hash=item2ee2682f79:g:ZYUAAOSwu4BVwVN8
> 
> At the moment I try to use what I have, because I already have a "stockpile" of tubes and I still haven't tried the 6HM5.
> And again comes in my mind the question: C3G or MK4 or Feliks Audio Elise? And for Feliks I cannot use the "stockpile" so another tube quest is starting and so on. I feel like a hamster trying to keep busy


 

 ​I think a lot can sympathise with that !.


----------



## hypnos1

dobigstuff said:


> Finally have all the pieces in play.  See Below:  (Still need to get some NOS 6SN7's)


 
  
  


scutey said:


> ​Everything I've used with the c3g's has sounded good, 6n6p/ir , and my 6sn7's, EH, Philips JAN6sn7wgta and PSAVENE UK-6SN7. At the mo I've got hold of some Foton 1965 6n6p and they sound great with them too, my experience so far is that they pair well with most tubes.


 
  
  


octavianh said:


> Ok, then maybe in the summer I'll order some of these:
> http://www.ebay.de/itm/2pc-C3G-TO-6AK5-5654-6096-adapter-for-little-dot-MKIII-SE-Headphone-/201366974329?hash=item2ee2682f79:g:ZYUAAOSwu4BVwVN8
> 
> At the moment I try to use what I have, because I already have a "stockpile" of tubes and I still haven't tried the 6HM5.
> And again comes in my mind the question: C3G or MK4 or Feliks Audio Elise? And for Feliks I cannot use the "stockpile" so another tube quest is starting and so on. I feel like a hamster trying to keep busy


 

 Hi guys.
  
 It warms my heart that the C3g is still well regarded after all this time, and since I defected to kick start the Feliks-Audio Elise (in the hope I could adapt these wonderful tubes to also work in its 6SN7/6AS7G configuration...and which it does very well indeed lol!..even though I've since betrayed my beloved C3g'S' by adapting other tubes in its place 
	

	
	
		
		

		
			





...).
  
 And of course therefore, OctavianH, I have to recommend you go for the Elise...it surpassed by a good margin even my MKIV SE, complete with Siemens C3g 'S'/GEC CV2523 (6AS7G) combo!!
 But good luck with whatever you finally choose...


----------



## gibosi

I won't go so far as to endorse any one amp, but I do not believe that the MK4 is enough of an upgrade over the MK2 to be worth the money. On the other hand, if and when you decide that an upgrade is in your future, a 6AS7 / 6SN7 amp, such as the Elise, will blow the MK4 out of the water.
  
 But of course, an improvement of this magnitude comes with price to match. These amps are more expensive and the tubes are more expensive. So if you can find a way to stay happy with the MK2, your wallet will thank you.


----------



## OctavianH

This is exactly my opinion guys about the MK series.MK2-3-4 are almost the same design but with better components and better tubes. I guess the guys at Little dot designed MK2, then saw it was getting quite hot so they changed the chasis and improved some of the design and sold it as MK3. And then they continued to add more expensive capacitors and jacks and stuff and created the MK4. But an upgraded MK2 like mine has to be very near of his bigger brothers and the price difference for the upgrade does not provide the same amount of performance increase.
 Now, since I own the MK2 for less than a year I plan to keep it, at least now.
  
 But can anyone describe me more the difference of the sound of Elise?
  
 How is the sound compared to MK series and what is much better there?


----------



## gibosi

I haven't heard the Elise, so I can't really say... But my Glenn is better in every way imaginable....


----------



## CJG888

I am considering replacing the Mullard CV4010 driver valves in my LD Mk III with C3Gs. Do you think they will be a good match with the NOS Sylvania 5687 (on adapters) which I am currently using as output valves? Are they a drop-in replacement (with the correct adapters), or do I need to adjust the jumpers?

Also, is there a reversible, non-destructive way of removing the brass rings? I don't really want to be stacking adapters on top of socket savers!

The amp is primarily used with 600 Ohm DT880s and modified 250 Ohm DT770s (occasionally 25 Ohm DT48E).


----------



## MIKELAP

cjg888 said:


> I am considering replacing the Mullard CV4010 driver valves in my LD Mk III with C3Gs. Do you think they will be a good match with the NOS Sylvania 5687 (on adapters) which I am currently using as output valves? Are they a drop-in replacement (with the correct adapters), or do I need to adjust the jumpers?
> 
> Also, is there a reversible, non-destructive way of removing the brass rings? I don't really want to be stacking adapters on top of socket savers!
> 
> The amp is primarily used with 600 Ohm DT880s and modified 250 Ohm DT770s (occasionally 25 Ohm DT48E).


 
 The rings have to be unscrewed from the inside of the chasis so you have to remove the board inside to get to those screws .i used a dremel to cut them way way easier. and if you want rings you can always get them on Ebay maybe even to fit the bigger tubes you will be using.                                                                                                                                                                                                                                 
  
 .                                                                                                                                                                                                               .


----------



## CJG888

I presume removing the board entails disconnecting the transformer...


----------



## CJG888

... I guess I could use this as an excuse to upgrade the capacitors!


----------



## TrollDragon

cjg888 said:


> I presume removing the board entails disconnecting the transformer...


 
 You have to unsolder the front and rear panels from the board as well as the transformer connections.


----------



## Whelkie D

Almost finished my LD Mk2 cooling "device"...........................................


----------



## XSAMURAI

whelkie d said:


> Almost finished my LD Mk2 cooling "device"...........................................


 
 what is that ? a time machine


----------



## lglions

You need to feed your creation from this:


----------



## CJG888

Only in Shenzhen....


----------



## Whelkie D

xsamurai said:


> what is that ? a time machine


 
 Not yet, but with a bit more copper pipe I could add a time travel function to it. (I may need an old alarm clock for that)


----------



## Scutey

whelkie d said:


> Almost finished my LD Mk2 cooling "device"...........................................


 
 Wow!, that's a very impressive looking piece of kit!, seriously steampunk!.


----------



## Whelkie D

scutey said:


> Wow!, that's a very impressive looking piece of kit!, seriously steampunk!.


 
 Thanks Scutey. The top box has 3 fans in it drawing air up the pipes near the tubes and blowing it out of the back. So far it seems to be keeping things cooler without too much noise


----------



## gulakpi

whelkie d said:


> Thanks Scutey. The top box has 3 fans in it drawing air up the pipes near the tubes and blowing it out of the back. So far it seems to be keeping things cooler without too much noise


 

 ​Surely impressive!  Must have been a fun project!


----------



## Whelkie D

gulakpi said:


> ​Surely impressive!  Must have been a fun project!


 
 Thanks gulakpi. Yes , it's a project that I can add bit to in future.


----------



## OctavianH

scutey said:


> ​Everything I've used with the c3g's has sounded good, 6n6p/ir , and my 6sn7's, EH, Philips JAN6sn7wgta and PSAVENE UK-6SN7. At the mo I've got hold of some Foton 1965 6n6p and they sound great with them too, my experience so far is that they pair well with most tubes.


 
  
 Ok, challenge accepted. I had this week the chance to sell ony of my DACs which I was not using anymore to a friend, so I have decided to reinvest some of the money into more fun.
 I ordered 2 Siemens C3G + a pair of adapters from Hong Kong. But it will take 3 weeks to receive them. Since I am not in a hurry I decided to take standard shipping.
 We will hear in one month with some impressions. And it seems to me that I am the lucky person who does not have to cut any rings, since MK2 does not have them.


----------



## Scutey

octavianh said:


> Ok, challenge accepted. I had this week the chance to sell ony of my DACs which I was not using anymore to a friend, so I have decided to reinvest some of the money into more fun.
> I ordered 2 Siemens C3G + a pair of adapters from Hong Kong. But it will take 3 weeks to receive them. Since I am not in a hurry I decided to take standard shipping.
> We will hear in one month with some impressions. And it seems to me that I am the lucky person who does not have to cut any rings, since MK2 does not have them.


 

 ​Hi OctavianH,
  
 Welcome to the C3G club! 
	

	
	
		
		

		
			





​. I wont bore you again with what they sound like as I'm sure I've already done that just hope you enjoy em!.


----------



## dobigstuff

octavianh said:


> Ok, challenge accepted. I had this week the chance to sell ony of my DACs which I was not using anymore to a friend, so I have decided to reinvest some of the money into more fun.
> I ordered 2 Siemens C3G + a pair of adapters from Hong Kong. But it will take 3 weeks to receive them. Since I am not in a hurry I decided to take standard shipping.
> We will hear in one month with some impressions. And it seems to me that I am the lucky person who does not have to cut any rings, since MK2 does not have them.


 
 OctavianH:
  
 As Scutey said,  You will love them.  They are dead quiet.  Look what they made me do (Ha Ha Ha)


----------



## Scutey

dobigstuff said:


> OctavianH:
> 
> As Scutey said,  You will love them.  They are dead quiet.  Look what they made me do (Ha Ha Ha)


 
 Lol. That was the first thing I did when I put them in, just couldn't help myself!.


----------



## gulakpi

​ 
	

	
	
		
		

		
			





  The C3g fun club!


----------



## OctavianH

I think I will have exactly the same adapters. They were shipped today from Hong Kong. But it will take some time to reach the end of the world where I am living. I plan to use these C3G with 6N6P-IR and check if I like them more than the Voskhods. I looked also on the 6H30P-DR but the price is astronomical. I do not think I will spend more than 100EUR on a powertube.
  
 I see that you use some adapters also for the powertubes to be able to put 6SN7. It is such a big difference?


----------



## Scutey

http://www.head-fi.org/t/117677/the-reference-6sn7-threadQuote: 





octavianh said:


> I think I will have exactly the same adapters. They were shipped today from Hong Kong. But it will take some time to reach the end of the world where I am living. I plan to use these C3G with 6N6P-IR and check if I like them more than the Voskhods. I looked also on the 6H30P-DR but the price is astronomical. I do not think I will spend more than 100EUR on a powertube.
> 
> I see that you use some adapters also for the powertubes to be able to put 6SN7. It is such a big difference?


 

 ​You need the adapters as the 6SN7 is an octal base. The 6SN7 is a more refined sound than the 6n6 type, depends on the tube of course but they also tend to have slightly better detail, imaging, soundstage etc, also there is a far greater number of options with this type, from the very cheap to the insanely expensive. This is a link to the 6SN7 thread.


----------



## OctavianH

scutey said:


> ​You need the adapters as the 6SN7 is an octal base. The 6SN7 is a more refined sound than the 6n6 type, depends on the tube of course but they also tend to have slightly better detail, imaging, soundstage etc, also there is a far greater number of options with this type, from the very cheap to the insanely expensive. This is a link to the 6SN7 thread.


 
  
 As far as I know, 6SN7 need more current to work properly. This does not create any overheating problems?
 I guess I will to try this on MK2. Maybe on MK3 or MK4 the circuit handles these ones but I am not sure to try something like this on mine.
  
 And regarding C3G, setting remains to EF95, but should I worry about something? Or just plug and play and no other problems.


----------



## Scutey

octavianh said:


> As far as I know, 6SN7 need more current to work properly. This does not create any overheating problems?
> I guess I will to try this on MK2. Maybe on MK3 or MK4 the circuit handles these ones but I am not sure to try something like this on mine.
> 
> And regarding C3G, setting remains to EF95, but should I worry about something? Or just plug and play and no other problems.


 

 ​Yes with the C3G it is the EF95 setting, you shouldn't have any problems as it is plug and play with the adapters.
  
 As for the 6SN7 I have the MK3 so can only say from my experiences with that but I had no problems with overheating, in fact the opposite was the case all the 6SN7's I've used in my LD run cooler than the 6N6 type.


----------



## OctavianH

scutey said:


> ​Yes with the C3G it is the EF95 setting, you shouldn't have any problems as it is plug and play with the adapters.
> 
> As for the 6SN7 I have the MK3 so can only say from my experiences with that but I had no problems with overheating, in fact the opposite was the case all the 6SN7's I've used in my LD run cooler than the 6N6 type.


 
  
 So you advise to try also some 6SN7 power tubes for these C3G?
  
 In that case I will need another adapters and I have to decide which power tubes to order (manufacturer, if 6SN7G or without G and so on).


----------



## Scutey

octavianh said:


> So you advise to try also some 6SN7 power tubes for these C3G?
> 
> In that case I will need another adapters and I have to decide which power tubes to order (manufacturer, if 6SN7G or without G and so on).


 

 ​The 6SN7 works very well with the C3G, of course we all have different set ups, tastes and the way we hear but the consensus on Head-Fi seems to be that the 6SN7/C3G is probably about as good as you can get with LD MK2/3/4, the adapters you need are the 6SN7 to ECC88, as for what type of 6SN7  to go for well you have a huge amount of types to choose from, the best thing I can suggest is to read that 6SN7 Reference thread, I found it to be invaluable.


----------



## OctavianH

scutey said:


> ​The 6SN7 works very well with the C3G, of course we all have different set ups, tastes and the way we hear but the consensus on Head-Fi seems to be that the 6SN7/C3G is probably about as good as you can get with LD MK2/3/4, the adapters you need are the 6SN7 to ECC88, as for what type of 6SN7  to go for well you have a huge amount of types to choose from, the best thing I can suggest is to read that 6SN7 Reference thread, I found it to be invaluable.


 
  
 Yep, I think these adapters will fit:
 http://www.ebay.com/itm/1piece-gold-plated-6SN7-B65-to-Mullard-ECC88-6922-6DJ8-Tube-converter-adapter-/201816047925?hash=item2efd2c8135:g:NA8AAOSwLVZVoK06
  
 Am I right?


----------



## dobigstuff

octavianh said:


> Yep, I think these adapters will fit:
> http://www.ebay.com/itm/1piece-gold-plated-6SN7-B65-to-Mullard-ECC88-6922-6DJ8-Tube-converter-adapter-/201816047925?hash=item2efd2c8135:g:NA8AAOSwLVZVoK06
> 
> Am I right?


 
 OctavianH
  
 These are the ones you need:
  
 http://www.ebay.com/itm/201330219735?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT


----------



## dobigstuff

OctavianH:
  
 These are for the C3G's:
  
 http://www.ebay.com/itm/201330219735?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT


----------



## Scutey

dobigstuff said:


> OctavianH
> 
> These are the ones you need:
> 
> http://www.ebay.com/itm/201330219735?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT


 
  


dobigstuff said:


> OctavianH:
> 
> These are for the C3G's:
> 
> http://www.ebay.com/itm/201330219735?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT


 

 ​Apologies for not replying sooner, as dobigstuff says those are the correct adapters, from the same seller I bought mine.


----------



## gibosi

octavianh said:


> As far as I know, 6SN7 need more current to work properly. This does not create any overheating problems?
> I guess I will to try this on MK2. Maybe on MK3 or MK4 the circuit handles these ones but I am not sure to try something like this on mine.


 
  
 No, the 6SN7 requires less current than the stock Russian tubes, 0.6A versus 0.9A. And as a result, the 6SN7 cannot drive low-Z headphones as well as the Russian tubes.


----------



## OctavianH

I read some stuff on the 6SN7 reference thread and I am quite confused at the moment. Hopefully for the first phase the 6N6P-IR+C3G will make a difference. At least until I realize what Power tubes I need from this 6SN7 family. I look for fast/clean/colder sound to match with my T1 (similar to 6N6P-IR)


----------



## Scutey

http://www.ebay.co.uk/itm/222464803258?_trksid=p2060353.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AITQuote: 





octavianh said:


> I read some stuff on the 6SN7 reference thread and I am quite confused at the moment. Hopefully for the first phase the 6N6P-IR+C3G will make a difference. At least until I realize what Power tubes I need from this 6SN7 family. I look for fast/clean/colder sound to match with my T1 (similar to 6N6P-IR)


 

 ​I've found the 6N6P-IR and the C3G to be a good match, the clarity and detail with this combo is very good.
  
 The first time I read the 6SN7reference thread it was enough to make my head spin!, one I'd read it a couple times it started to make sense.
  
 One that might be right for you going on what you've said is the Philips JAN6SN7WGTA, it's a rebadged Sylvania, from the mid eighties, it's a coolish, quite fast tube, with good detail, sonically similar to the 6N6P-IR, the only thing there's not much info on them, anywhere, there is some for sale on ebay at the mo, this is the link if you are interested.


----------



## OctavianH

I have to thank you again Scutey for all your help and advices. I am like a kid asking daily for stuff and I hope I am not becoming annoying.
 I just took a look on ebay and saw that these tubes have much smaller prices in the US than Europe (almost half the price?).
 For example these ones in UK:
 http://www.ebay.de/itm/6SN7WGTA-JAN-PHILIPS-ECG-NOS-/270762188350?hash=item3f0aaf1e3emalxRgSUgLyK7SLP2Qjuh8w
 I will continue to check the offers since the adapters will come in 1 month. Then, who knows, maybe I will try some 6SN7 just to see how they sound. If possible I will choose to buy from EU since I avoid extra taxes and transport. But of course, if the price difference is big I can try to oder directly from US. I have 4 pieces of 6N6P-IR so there is no hurry.
 Maybe I have worse ears than others, but for me the 2Qute with Voskhods and 6N6P-IR sounds heavenly. It has that amount of aggressivity and speed I always wanted and makes T1 sound very clean and full.


----------



## OctavianH

By the way I found by mistake these russian 6H8C:
 https://www.olx.ro/oferta/vand-6-tuburi-electronice-rusesti-6h8c-6sn7-ID8fuyZ.html#91d380aaac
 Anyone knows if these are ok for MK series? The price is cheap, and they are 6 ('73 and '77 from what I see on the picture)
 It seems these are russian equivalents of 6SN7 but I do not know anything about them.


----------



## MIKELAP

octavianh said:


> By the way I found by mistake these russian 6H8C:
> https://www.olx.ro/oferta/vand-6-tuburi-electronice-rusesti-6h8c-6sn7-ID8fuyZ.html#91d380aaac
> Anyone knows if these are ok for MK series? The price is cheap, and they are 6 ('73 and '77 from what I see on the picture)
> It seems these are russian equivalents of 6SN7 but I do not know anything about them.


 
 i have some 6H8C from Reflektor plant dated 1962 . I was  told they were the  good ones to have with the tab each side on top .


----------



## OctavianH

So, should I try these as power tubes when my adapters arrive or I should go "the normal way" finding some Philips as Scutey suggested?


----------



## MIKELAP

octavianh said:


> So, should I try these as power tubes when my adapters arrive or I should go "the normal way" finding some Philips as Scutey suggested?


 
 Half the fun is trying them out since Russian tubes  are not expensive. Philips why not .There's no really bad choices just many flavors find yours .That's the way i look at it .


----------



## Scutey

octavianh said:


> So, should I try these as power tubes when my adapters arrive or I should go "the normal way" finding some Philips as Scutey suggested?


 

 ​Maybe narrow it down to 2 or 3 types of tubes you like the look of, see what the consensus is on them and then check the sort of prices on ebay etc and then make a decision. take your time looking and deciding. Unless you can try them first, and that's probably impossible most of the time, there is going to be a leap of faith when buying some tubes, you could go the cheap route something like the Foton, and if you don't like it you haven't lost too much, or the more expensive old stock/ NOS route, Sylvania, RCA, Raytheon etc and, if you don't like them you could resell them and probably get back most, if not all what you paid for them. BTW keep on asking the questions when your not sure about something, that's what Head-Fi is all about, after all it's what I do!


----------



## i luvmusic 2

WOW! It's nice to see this thread blossoming again.


----------



## OctavianH

mikelap said:


> Half the fun is trying them out since Russian tubes  are not expensive. Philips why not .There's no really bad choices just many flavors find yours .That's the way i look at it .


 
 You are right Mike, the pleasure is in the trip and not only in the destination. I wrote to the guy since he sells them very cheap (25USD for 6 pieces) and the transport is almost free since he lives in the same country as me. So for 25USD I think I will buy them and we will see what will happen later. I will try to find more info about them because it seems they are not "well known" as other brands.
  
 Later edit: I talked to the guy and seemed a nice person. So for 25 bucks I decided to take them. Hopefully I will find something good in them otherwise I will soon need a new house to keep all my unused tubes. And of course, I have to wait for the adapters. If I will not like them I will add 6 new ones in my collection.
 A good friend of mine makes already jokes on me like "there are several nuclear rocket powers in the world and one of them is me, so he tries not to upset me".
 What to say, if I will get upset I will put my HPs on his head and put him to 20hrs of Black Sabbath. Might be a torture, might be a relief. He knows.


----------



## MIKELAP

octavianh said:


> mikelap said:
> 
> 
> > Half the fun is trying them out since Russian tubes  are not expensive. Philips why not .There's no really bad choices just many flavors find yours .That's the way i look at it .
> ...


 
 Talking about these russian tubes i started looking on Ebay and found these tubes there's 6 of them from fifties NOS  guy was asking $30.00 igot them for $20.00 and are similar to the ones i have so they should be good


----------



## Scutey

mikelap said:


> Talking about these russian tubes i started looking on Ebay and found these tubes there's 6 of them from fifties NOS  guy was asking $30.00 igot them for $20.00 and are similar to the ones i have so they should be good


 
 Hi MIke, what are those Foton tubes like, are they any good?.


----------



## MIKELAP

scutey said:


> mikelap said:
> 
> 
> > Talking about these russian tubes i started looking on Ebay and found these tubes there's 6 of them from fifties NOS  guy was asking $30.00 igot them for $20.00 and are similar to the ones i have so they should be good
> ...


 
 For the price i like them there not the bassiest of tubes like the Kenrad VT-231 but they have a nice clean balanced sound this is on a Crack with Speedball and Senns HD 800S sounded a little thinner on MK3 but as they say your ears and your gear


----------



## OctavianH

The tubes from this guy are from '73 and '77 (the ones I asked about) and I think it is a very big difference from the ones from '50s and '60s and these. And they do not seem to be made by Foton.
 I read some forums and all claim some of them are good, some very bad. I have to call him again to send them, because he asked me to confirm this evening.
 I have to decide fast if I take them or not.
  
 OK, decided, life is too short to think too much for 25USD:
 - I took the russian 6H8C and I will try them when adapters arrive
 - I took also 2 Philips 6SN7WGTA (green marking) (the ones which Scutey advised)
  
 My shopping is done, now let's hope adapters arrive and I can try them. I am curious to see if C3G + any of these will sound better than actual setup.


----------



## Scutey

octavianh said:


> The tubes from this guy are from '73 and '77 (the ones I asked about) and I think it is a very big difference from the ones from '50s and '60s and these. And they do not seem to be made by Foton.
> I read some forums and all claim some of them are good, some very bad. I have to call him again to send them, because he asked me to confirm this evening.
> I have to decide fast if I take them or not.
> 
> ...


 
 I hope you enjoy your new tubes Octavian, getting new tubes is always a bit of a gamble until you hear them for yourself, I've just busted my wallet on some Ken-Rad JAN-CKR GT's and am wondering if I did the right thing, but, as you say, life is too short, so if I don't like em i'll have a bit of a grumble and sell them on and just put it down to one of life's little mistakes!. Oh and i'll be keeping me fingers crossed you like those WGTA's! .


----------



## gibosi

While the 6SN7 is a great audio tube, don't forget about the 5687. This tube was developed for use in early computer circuits and as a result it is very linear with low distortion. Further, the heater current draw is 0.9A at 6.3V, which makes it better suited to drive low-Z cans.
  
 Like the 12AU7, these can be used in both 6.3 and 12.6 volt circuits. So you need to use an adapter to allow it to be used in an ECC88 socket, such as this one:
  
 http://www.ebay.com/itm/1-5687-To-6N6-6N2-ECC88-Vacuum-Tube-Amplifier-Convert-Socket-Adapter-/152506153990


----------



## Scars Unseen

So despite having owned my little Dot mk III for about 5 year now, I never got into tube rolling.  I decided that needs to change.  I'm starting out looking for some relatively inexpensive tubes to try out, and I started with a matched pair of Voshkod 6ZH1P-EVs that I found for $16 on ebay.  It'll be interesting seeing what sort of difference they make.


----------



## Scutey

scars unseen said:


> So despite having owned my little Dot mk III for about 5 year now, I never got into tube rolling.  I decided that needs to change.  I'm starting out looking for some relatively inexpensive tubes to try out, and I started with a matched pair of Voshkod 6ZH1P-EVs that I found for $16 on ebay.  It'll be interesting seeing what sort of difference they make.


 

 ​If you have just had the stock tubes in then you will notice a difference with the Voskhod, they are quite a fast tube, rather cool/dry sounding with good detail and slam, if you don't want to spend too much another very good tube is the EI 6HM5, slightly warmer than the Voskhod, has very good clarity/detail, good extended highs tight bass and detailed mids, they are at least as cheap, if not cheaper. Here's a link to these tubes.http://www.ebay.co.uk/itm/261943723655?_trksid=p2060353.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT


----------



## Scars Unseen

scutey said:


> ​If you have just had the stock tubes in then you will notice a difference with the Voskhod, they are quite a fast tube, rather cool/dry sounding with good detail and slam, if you don't want to spend too much another very good tube is the EI 6HM5, slightly warmer than the Voskhod, has very good clarity/detail, good extended highs tight bass and detailed mids, they are at least as cheap, if not cheaper. Here's a link to these tubes.http://www.ebay.co.uk/itm/261943723655?_trksid=p2060353.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT


 
 I'll take that advice, thanks.  I figure I'll slowly build up a collection to try out and see what I like.


----------



## Policar

Why does the little dot mkii sound considerably better when turned off and fed through the "output" RCA jacks (disabling the potentiometer) than turned on and fed through the "input" RCA jacks? Will replacing the tubes fix this?
  
 Overall... I am not a fan of this amp out of box but I was curious to try it. Weirdly it sounds pretty good hooked up wrong.


----------



## TrollDragon

policar said:


> Why does the little dot mkii sound considerably better when turned off and fed through the "output" RCA jacks (disabling the potentiometer) than turned on and fed through the "input" RCA jacks? Will replacing the tubes fix this?
> 
> Overall... I am not a fan of this amp out of box but I was curious to try it. Weirdly it sounds pretty good hooked up wrong.


 
 The RCA line out jacks are directly connected to the headphone out jack on the board. You are not disabling the volume control connecting it up that way, you are bypassing the amplifier.

 If it is loud enough that way, then what are you using as a source and what headphones?


----------



## Policar

trolldragon said:


> The RCA line out jacks are directly connected to the headphone out jack on the board. You are not disabling the volume control connecting it up that way, you are bypassing the amplifier.
> 
> If it is loud enough that way, then what are you using as a source and what headphones?


 

 It's barely loud enough but still sounds good. I'm using a gamma2 DAC and HD650s with everything at maximum volume, and running the tube am as a pre-amp into my ESP950s, which have their own amp.
  
 That makes sense, though. So far, the only amp that sounds better than the gamma2 with the HD650s is the bottlehead crack with speedball but I'm going to try some Mullard tubes now. That makes sense, though. The stock tubes sound congested, muddy bass, sibilant treble.


----------



## MIKELAP

If anybody is interested in purchasing  LITTLEDOT COMPATIBLE tubes i have some for sale on the FOR SALE FORUM here's the link .6HM5,8100,6AK5,6AU6 with adapters ects. Thank you                                                                                                                       http://www.head-fi.org/t/840068/tubes-compatible-with-littledot-1-mk2-mk3-mk4-mk4se-for-sale


----------



## OctavianH

Happy Easter everybody,
  
 If you need some Light I recommend you better tubes


----------



## Policar

I've got some Mullard tubes on the way, should I also replace the power tubes? I would like to reclaim my Crack (which sounds great btw) for my HD650s. :/ The stock sound is very disappointing to me but I'll wait to try out the new tubes.


----------



## OctavianH

I have no idea how the Crack sounds, but I say you should replace your power tubes with 6N6P-IR or 6N6P.


----------



## Policar

octavianh said:


> I have no idea how the Crack sounds, but I say you should replace your power tubes with 6N6P-IR or 6N6P.


 

 What kind of difference will that make in sound? 
  
 I'm sure this as a pre-amp for my ESP950s btw, but also for dynamic headphones as an amp from time to time.


----------



## OctavianH

I do not remember clearly how the stock tubes sounded because I changed them in the first days. But what can I say is that there is a big improvement on clarity/detail if you upgrade both driver and power tubes. For me, the perfect sound was quite neutral. But everything depends on the rest of your line. All I say is that you should upgrade both driver and power tubes, since the Chinese stock ones sound quite crappy. I cannot say very much about HD650 since I sold my pair, for me they sounded too bassy and the "Sennheiser veil" was too pronounced. Being a fan of neutral/clear/fast sound I always enjoyed the Beyerdynamic Testla headphones and for my setup the best power tubes are 6N6P-IR. 6N6P are somehow warmer, with more bass.


----------



## Policar

octavianh said:


> I do not remember clearly how the stock tubes sounded because I changed them in the first days. But what can I say is that there is a big improvement on clarity/detail if you upgrade both driver and power tubes. For me, the perfect sound was quite neutral. But everything depends on the rest of your line. All I say is that you should upgrade both driver and power tubes, since the Chinese stock ones sound quite crappy. I cannot say very much about HD650 since I sold my pair, for me they sounded too bassy and the "Sennheiser veil" was too pronounced. Being a fan of neutral/clear/fast sound I always enjoyed the Beyerdynamic Testla headphones and for my setup the best power tubes are 6N6P-IR. 6N6P are somehow warmer, with more bass.


 

 Thanks, that's helpful. The Crack for whatever reason lifts a lot of the veil, while I have not used any other amp that does. It's kind of amazing, the HD650s sound _good _all of a sudden instead of good through five layers of felt. But still a little felty. I preferred my DT1350s (apparently quite similar to a mini-T1 in sound character if not sound quality) until I added that amp and they are still my go-to for work etc.

 But I want to use this as a pre-amp for my ESP950 electrostatic headphones since they benefit from some smoothing out, too, and some warm bass. The stock tubes sound awful to me, worse than nothing. Tinny, congested, no bass. I will try the Mullards and 6N6P? Those work together well? Where should I order the 6N6P from? (I already have the Mullards, just haven't installed them yet.)


----------



## OctavianH

HD650 are good headphones, but not for what I listen. I listen to rock/metal which is fast and complicated. HD650 sounded great on soundtracks or Depeche Mode, but for rock they are far below T1s. And T1s are quite great on tube amps. If you prefer more detail and clarity I say you should go for 6N6P-IR as power tubes and Mullard 8161 (EF92) as drivers (do not forget to change jumpers). If you prefer more aggressive/fast sound on mids, for rock, the best are Voskhod 6J1P-EV.


----------



## Policar

I'm not crazy about the HD650s either but I do think they get less veiled with th right amp, and the Little dot has not improved them. I just want to use this as a pre-amp for my elecrtostats, though
  
 I bought these
  
 http://www.ebay.com/itm/122440660580?ul_noapp=true
  
 Is that the wrong one? It looked like it would be EF95 compatible. 
  
 Anyhow, which tubes should I get? I can still return them.


----------



## Scutey

> JPosted by *Policar* /img/forum/go_quote.gif
> I'm not crazy about the HD650s either but I do think they get less veiled with th right amp, and the Little dot has not improved them. I just want to use this as a pre-amp for my elecrtostats, though
> 
> I bought these
> ...


 

 Policar,
  
 I had those as stock tubes with my MK III, i'm fairly sure they are French RTC tubes NOT Mullard, they are ok but not as good as Mullard, if you want Mullard the ones to go for are the mill spec versions, the M8100 (EF95), or the M8161 (EF92), and as for the power tubes Octavian is right, the 6N6P and 6N6P-IR are a definite improvement over the stock, as to which is better as always it's very subjective, the 6N6P is slightly warmer with stronger bass, the 6N6P-IR is cooler slightly better clarity/detail and a tad less bass.  Here is a link to some Mullard M8100 to give you an idea.
  
 http://www.ebay.co.uk/itm/M8100-CV4010-EF95-MULLARD-BLACK-PLATE-8140-NOS-E-MATCHED-PAIR-VALVE-TUBE-A16-/371599617046?
 hash=item5685102c16:gy4AAOSw7KJXDpk


----------



## Policar

scutey said:


> Policar,
> 
> I had those as stock tubes with my MK III, i'm fairly sure they are French RTC tubes NOT Mullard, they are ok but not as good as Mullard, if you want Mullard the ones to go for are the mill spec versions, the M8100 (EF95), or the M8161 (EF92), and as for the power tubes Octavian is right, the 6N6P and 6N6P-IR are a definite improvement over the stock, as to which is better as always it's very subjective, the 6N6P is slightly warmer with stronger bass, the 6N6P-IR is cooler slightly better clarity/detail and a tad less bass.  Here is a link to some Mullard M8100 to give you an idea.
> 
> ...


 

 Thanks, I'll return these and get some of those. Where should I buy them or should I just trawl eBay? Now I want to go somewhere reliable.
  
 Will it make a big difference? Right now the amp sounds awful compared with the crack, which has good tubes. The 6N6P sounds prefect for me, I need more bass.


----------



## Scutey

: 





policar said:


> Thanks, I'll return these and get some of those. Where should I buy them or should I just trawl eBay? Now I want to go somewhere reliable.
> 
> Will it make a big difference? Right now the amp sounds awful compared with the crack, which has good tubes. The 6N6P sounds prefect for me, I need more bass.


 

 ​Well I've never heard the crack so can't comment on that but you should see a significant difference with the Mullard, although, as always. these things are very subjective. if you need more bass then the M8100 should give you that as will the 6N6P for powers, although its worth bearing in mind that both are quite warm bassy tubes, the 6N6P-IR is also worth considering. Here is a link for a good seller in the UK who I've bought tubes from and is reliable. http://www.ebay.co.uk/itm/M8100-CV4010-5654-MULLARD-VINTAGE-MATCHED-PAIR-VALVE-TUBES-SQUARE-GETTER-/272442375482?hash=item3f6ed4bd3a​
 Quote
  
 http://www.ebay.co.uk/itm/6N6P-ECC99-LITTLE-DOT-MK2-3-USSR-MATCHED-PAIR-VALVE-TUBE-/262564320395?hash=item3d220d948b


----------



## TrollDragon

policar said:


> Thanks, I'll return these and get some of those. Where should I buy them or should I just trawl eBay? Now I want to go somewhere reliable.
> 
> Will it make a big difference? Right now the amp sounds awful compared with the crack, which has good tubes. The 6N6P sounds prefect for me, I need more bass.


 
 IMHO I really don't think you will get the LD MKII to sound anywhere close to the Crack, but I could be wrong. You would have to modify the LD MKII to accept a dual triode like the 6DJ8/6922 as a preamp and a 6080/6AS7G as output.
  
 Maybe @MIKELAP can chime in here as he chased a massive quantity of tubes for his LD MKIII before he obtained his Crack.


----------



## MIKELAP

trolldragon said:


> policar said:
> 
> 
> > Thanks, I'll return these and get some of those. Where should I buy them or should I just trawl eBay? Now I want to go somewhere reliable.
> ...


 
 I had the the MK3 and the best setup i found with only adapters was with C3G's up front and 6SN7 as power tubes and even then to me amp sounded  thinner compared to a WA6 or a Crack. so it has its limits i would say. But for what it is it sounds great call it a different flavor That was with Senns HD800 so YMMV.


----------



## OctavianH

My 6H8Cs arrived today, but I cannot try them yet because the adapters are somewhere on the road.
  
 So, some pictures with the monkey:
  

  

  
 They seem quite similar with what MIKELAP posted here a few pages ago. Anyhow, no "OKT" on them, which as far as I know was the Quality Control OK. This one is from '77, made in CCCP, but other 2 of them are from '73.


----------



## OctavianH

Guys,
  
 Adapter question because I am quite confused.
 What is the difference between:
  
 http://www.ebay.com/itm/1pc-Gold-plated-6SN7-6n8p-CV181-TO-6CG7-6FQ7-tube-converter-adapter-/201115946751
  
 and
  
 http://www.ebay.de/itm/201816047925?_trksid=p2060353.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT
  
 And which one will work with 6SN7 as power tubes? For me they look the same, even if they seem different products used for different tube types.


----------



## gibosi

octavianh said:


> Guys,
> 
> Adapter question because I am quite confused.
> What is the difference between:
> ...


 
  
 Both will work. The ECC88, 6DJ8, 6922, 6FQ7 and 6CG7 all have the same pinout.


----------



## OctavianH

Ah ok, pfuu, they look the same but I thought maybe wiring is different or something. 
  
 Later edit: 
  
 More goodies for me, but no year on these ones:


----------



## kamzak88

i looking for tubes for LD+ and grado. I want buy *6ZH1P-EV*
  
 this seller is ok?
 http://www.ebay.com/itm/2x-Voshkod-6ZH1P-EV-6J1P-EV-Matched-Pair-Little-Dot-Amp-III-IV-/142138665883?hash=item21181feb9b:g:bfYAAOSwUKxYkHgt
  
 or
  
 Mullard M8161/CV401
  
 http://www.ebay.com/itm/122459688105?ssPageName=STRK:MESINDXX:IT&_trksid=p3984.m1436.l2649


----------



## TrollDragon

kamzak88 said:


> i looking for tubes for LD+ and grado. I want buy *6ZH1P-EV*
> 
> this seller is ok?
> http://www.ebay.com/itm/2x-Voshkod-6ZH1P-EV-6J1P-EV-Matched-Pair-Little-Dot-Amp-III-IV-/142138665883?hash=item21181feb9b:g:bfYAAOSwUKxYkHgt
> ...


 
 Matched pairs are not required...

 You can get 4 of those 6Ж1П-EB from this seller for less than $10 shipped.
 http://www.ebay.com/itm/6J1P-EV-6ZH1P-EF95-6F32-6AK7-Lot-of-4-tubes-Voskhod-Little-Dot-Amplitrex-/282297663940


----------



## dobigstuff

octavianh said:


> Ah ok, pfuu, they look the same but I thought maybe wiring is different or something.
> 
> Later edit:
> 
> More goodies for me, but no year on these ones:


 
 OctavianH:
  
 How do those Jan Philips 6SN7's sound?  I have been trying to find a good pair of those.  They are supposed to be excellent.


----------



## Scutey

octavianh said:


> Ah ok, pfuu, they look the same but I thought maybe wiring is different or something.
> 
> Later edit:
> 
> More goodies for me, but no year on these ones:


 

 ​They are identical to mine. The box mine came in had a 7/86 date code, so I guess they will be of a similar date, give or take a year or two.


----------



## Scutey

dobigstuff said:


> OctavianH:
> 
> How do those Jan Philips 6SN7's sound?  I have been trying to find a good pair of those.  They are supposed to be excellent.


 

 ​They are very good, fast, clear/detailed I find them quite linear, bass isn't over pronounced, just tells you what's there, highs extend well mids nicely detailed, good imaging, coolish. There is a good UK ebay seller, LANGREX,http://www.ebay.co.uk/itm/6SN7WGTA-JAN-PHILIPS-ECG-NOS-/270762188350?hash=item3f0aaf1e3emalxRgSUgLyK7SLP2Qjuh8wQuote:


----------



## gibosi

dobigstuff said:


> How do those Jan Philips 6SN7's sound?  I have been trying to find a good pair of those.  They are supposed to be excellent.


 
  
 These are essentially Sylvania 6SN7GTB. Around 1980, Philips sold off their Holland and British vacuum tube assets, and in a move to obtain a stronger position in the US market, purchased Sylvania's Electronic Components and Consumer Electronics divisions, including the vacuum tube manufacturing business. So these "Philips" tubes were made in that same Sylvania factory. Only the brand name changed. Evidently, production at the factory ceased around 1987.


----------



## kamzak88

trolldragon said:


> Matched pairs are not required...
> 
> 
> You can get 4 of those 6Ж1П-EB from this seller for less than $10 shipped.
> http://www.ebay.com/itm/6J1P-EV-6ZH1P-EF95-6F32-6AK7-Lot-of-4-tubes-Voskhod-Little-Dot-Amplitrex-/282297663940




What is the difference between http://rover.ebay.com/rover/1/711-53200-19255-0/1?campid=5337413452&toolid=10001&mpre=http%3A%2F%2Fwww.ebay.com%2Fitm%2F2x-Voshkod-6ZH1P-EV-6J1P-EV-Matched-Pair-Little-Dot-Amp-III-IV-%2F142138665883%3Fhash%3Ditem21181feb9b%3Ag%3AbfYAAOSwUKxYkHgt and http://www.ebay.com/itm/6J1P-EV-6ZH1P-EF95-6F32-6AK7-Lot-of-4-tubes-Voskhod-Little-Dot-Amplitrex-/282297663940 lamps?


----------



## Scutey

kamzak88 said:


> What is the difference between http://rover.ebay.com/rover/1/711-53200-19255-0/1?campid=5337413452&toolid=10001&mpre=http%3A%2F%2Fwww.ebay.com%2Fitm%2F2x-Voshkod-6ZH1P-EV-6J1P-EV-Matched-Pair-Little-Dot-Amp-III-IV-%2F142138665883%3Fhash%3Ditem21181feb9b%3Ag%3AbfYAAOSwUKxYkHgt and http://www.ebay.com/itm/6J1P-EV-6ZH1P-EF95-6F32-6AK7-Lot-of-4-tubes-Voskhod-Little-Dot-Amplitrex-/282297663940 lamps?


 

 ​There is no difference, they are one and the same, I think one is Russian translation and one is an anglicised version of the same code/name, I could be wrong about the last bit but they are both the same tubes.


----------



## kamzak88

Same price but several times more expensive


----------



## J Mirra

I would like to thank everyone that has spoke about the C3g tubes and adaptors for the LDMK11

I had the Mullard 8100 & 6N6P-IR I have just swapped out the 8100's for the Lorenz C3g and what a difference, the hight of the stage is taller the width is wider and the music sounds more powerful and punchy using the T1.1

Everything I have read is true, thanks again.


----------



## Barndoor

Did you need to use extenders for the tubes to clear the LD case (the c3g are wider than standard LD tubes if I recall correctly)? If so do you have a link please. When I had a look at doing this in the past I managed to find tubes and an adapter but not an extender, so gave in.


----------



## J Mirra

I bought these adaptors and do not need an extender with these which is lucky as I did not realize you needed one.

http://www.ebay.co.uk/itm/201366974329?_trksid=p2060353.m2749.l2649&ssPageName=STRK:MEBIDX:IT


----------



## dobigstuff

J Mirra said:


> I bought these adaptors and do not need an extender with these which is lucky as I did not realize you needed one.
> 
> http://www.ebay.co.uk/itm/201366974329?_trksid=p2060353.m2749.l2649&ssPageName=STRK:MEBIDX:IT



You will get a better connection if you remove the Brass Trim Rings.  Aren't they are just barely making contact in the socket?


----------



## J Mirra (Apr 27, 2017)

They seem in fine in the socket and the adaptor.

I have just taken one adaptor out then back in and there is plenty of pin going in to the LDMK11


----------



## dobigstuff

Sorry, I thought you had the MK III.  Yes the MK II does not have the Brass Trim Rings.  You're Good.
Thanks,


----------



## J Mirra

No worries, better being safe, thanks.


----------



## OctavianH

So these adapters work with MK3 without cutting the rings? Good to know.


----------



## J Mirra

You do not have to cut rings on the MK11 as there is non on mine if you have the MK111 you have too.


----------



## dobigstuff

Correct.  You would need to take the front off, then disconnect the volume pot (white snap in connector) then take off the back.  Slide the board back to expose (2) screws in each Brass Trim Ring.
I hope that helps.


----------



## Hefeweizen

Hello all.  I am a relative newbie and could use a few suggestions for power tubes.   I currently have a Little Dot MKII, Beyerdynamic DT 990 and Sennheiser 598.   I conducted my own personal tube review on a variety of music using both headphones.    

Results:
1) Original Chinese power and signal tubes were quite good overall, warm tube sound, incredible power and dynamics, etc.    Keep in mind this is my first experience with a tube pre/power amp ever.
2) Mullard 8100 with the Chinese power tubes (6N6) were nice, maybe a little better overall (not that big of a change).
3) Voshkod 6ZH1P-EV with Chinese power tubes a little more dynamic, seemed more of an overall positive effect. 
4) Voshkod 6ZH1P-EV with Russian 6N6P-IR seemed very harsh. The noise floor and treble was increased to where I can not bear to listen to it - horrible combination.
5) Mullard 8100 and the Russian 6N6P-IR seemed best overall. The Mullards are very smooth, dynamic, powerful quick bass, extended treble without harshness.

I was quite surprised the power tubes could make that big of a difference. The Voshkods went from an improvement on the 6N6 to harsh/horrible on the 6N6P-IR, at least to my ears.

Given all this. I would like to stay with the Mullard 8100. 

Would a good 6N6P be a good choice as well? Any improvement over the Chinese 6N6 or Russian 6N6P-IR? 
I am really looking for smooth "tube" overall sound with a heavy quick bass without harsh treble.   I realize some of the harshness comes from the DT990.  The 598 are much much less harsh, but don't seem near as alive or real to me.   

I believe many also recommend the E288CC SIEMENS as best power tube.   Are these worth the price?   Do they pair well with the Mullard 8100?

Thank you all so much in advance.


----------



## Whelkie D

Hefeweizen said:


> Hello all.  I am a relative newbie and could use a few suggestions for power tubes.   I currently have a Little Dot MKII, Beyerdynamic DT 990 and Sennheiser 598.   I conducted my own personal tube review on a variety of music using both headphones.
> 
> Results:
> 1) Original Chinese power and signal tubes were quite good overall, warm tube sound, incredible power and dynamics, etc.    Keep in mind this is my first experience with a tube pre/power amp ever.
> ...


I found the Russian 6N6P (without the IR) to be a good match with the Mullard 8100. Slightly warmer than the IR version. Also recommend the Mullard 8161 as driver tube with the 6N6P although you would have to change the jumper to the EF92 setting but well worth the effort. Good luck and keep us posted.


----------



## Scutey

Hefeweizen said:


> Hello all.  I am a relative newbie and could use a few suggestions for power tubes.   I currently have a Little Dot MKII, Beyerdynamic DT 990 and Sennheiser 598.   I conducted my own personal tube review on a variety of music using both headphones.
> 
> Results:
> 1) Original Chinese power and signal tubes were quite good overall, warm tube sound, incredible power and dynamics, etc.    Keep in mind this is my first experience with a tube pre/power amp ever.
> ...



A driver tube worth trying is the EI 6HM5 (EF 95) setting, it has good detail  and fairly neutral, quite cheap too.


----------



## wendyKL

Hi I'm thinking about a Little Dot I+, how does it do with IEMs? I'm looking to connect it to an Audioquest Dragonfly RED from my laptop. Also how long do the tubes take to warm up?  I'm using Shure IEMs


----------



## Hefeweizen

Scutey said:


> A driver tube worth trying is the EI 6HM5 (EF 95) setting, it has good detail  and fairly neutral, quite cheap too.


Thank you very much.  I will look into these as well.


----------



## Hefeweizen

Whelkie D said:


> I found the Russian 6N6P (without the IR) to be a good match with the Mullard 8100. Slightly warmer than the IR version. Also recommend the Mullard 8161 as driver tube with the 6N6P although you would have to change the jumper to the EF92 setting but well worth the effort. Good luck and keep us posted.


Thank you.    How important is it to have 6N6P power tubes to be matched?  Is same date code enough, or is it essential to have all the characteristics to be matched within say 1% of each other?


----------



## gibosi

Hefeweizen said:


> Thank you.    How important is it to have 6N6P power tubes to be matched?  Is same date code enough, or is it essential to have all the characteristics to be matched within say 1% of each other?



Strict matching is not necessary. Two tubes manufactured at about the same time, in the same factory, with the same construction is close enough.


----------



## Hefeweizen

Thank you!   Makes things much easier.   Many selling with same date code, same factory, etc.    I will try some Russian 6N6P gold grids.       What about the Siemens E288CC?  Are they the best in the world?  Worth the price?  Or no better than the standard 6N6P?


----------



## Whelkie D

Hefeweizen said:


> Thank you.    How important is it to have 6N6P power tubes to be matched?  Is same date code enough, or is it essential to have all the characteristics to be matched within say 1% of each other?


There are conflicting views on this. I usually try to use power tubes that are matched to within 5%. I don't think it matters for the driver tubes although I'm sure some people will disagree.


----------



## MIKELAP

I never used matched pairs for power or driver tubes and never noticed anything different that would make me want to pay more for a match pair and i use 3 tube amps .The most matching i do is buy same brand same year same internal structure with the money you save there you can get more tubes


----------



## gibosi (Apr 30, 2017)

While I have no experience with the E288CC, I doubt that it would be as good as the 6N6P. The major, and to my mind, critical difference is that the 6N6P and similar tubes require about 750ma to 900ma of heater current. The E288CC requires only 450ma. In general, higher heater current yields higher plate output current.

Given that the 6SN7, with 600ma of heater current, is not up to the task of driving low-Z, inefficient headphones, I would supect that the E288CC would very likely be less "powerful" than a 6SN7.

Apart from the 6N6P family, the only other double triode with a heater current of around 900ma I am aware of is the 5687. However, the 5687 has a different pinout than the 6N6P and thus requires an adapter to reroute the pins.


----------



## Hefeweizen

Thank you all for the responses.   Has anyone tried to modify a Little Dot to a "choke" power supply?    I tried searching but count not find any reference.   Some say it will eliminate any phase distortion.


----------



## TrollDragon

Hefeweizen said:


> Thank you all for the responses.   Has anyone tried to modify a Little Dot to a "choke" power supply?    I tried searching but count not find any reference.   Some say it will eliminate any phase distortion.


There is not a lot of room inside the LD case, you would have to mount your choke and capacitors externally.


----------



## Scars Unseen

Okay, so I got the Voshkods that I ordered, and I'm trying out tube rolling for the first time.  No burn in time yet; just fresh into the socket.  First test using _Bela Fleck - Tales from the Acoustic Planet_.  My headphones are Beyerdynamic DT 880 Premiums.

First thing I noticed was that I actually _noticed_ the bass.  The stock tubes combined with my headphones always kept the bass a bit more subdued than this.  The difference isn't massive, but the upright bass has a bit of an extra pop to it that wasn't there before.  So mark that down a big plus.  

Actually, that might not just be on the bass.  It may be my imagination(I wish I could do a side by side listen), but it kind of feels like all of the plucked instruments are standing out more than before.  The same is probably true of the percussion, but this album doesn't put a lot of focus on the drums(which are actually coming from a synthesizer).  I'll have to try it with some rock or more traditional jazz to be sure.

The other thing I'm noticing is that the I find myself paying attention more to the background instruments in general.  Of course, I can't be sure that what I'm hearing is really something I couldn't hear as well before, or if I'm just paying more attention now.  I probably need some more casual listening time to get a full impression of the new tubes.

Overall, I'm pleased with the change, and it will be interesting seeing how these sound as they've settled in.


----------



## OctavianH

My c3g tubes arrived. Impressive packaging, seem new, but I am not sure if they are identical. On one of them the font seems somehow greyed and on the other white. Well, hopefully these will work fine when the adapters arrive.


----------



## kamzak88

I bought 6ZH1P 

http://www.ebay.pl/itm/282297664387?_trksid=p2057872.m2749.l2649&ssPageName=STRK:MEBIDX:IT


How to set gain (for Grado sr325e)?


----------



## Scutey

OctavianH said:


> My c3g tubes arrived. Impressive packaging, seem new, but I am not sure if they are identical. On one of them the font seems somehow greyed and on the other white. Well, hopefully these will work fine when the adapters arrive.


Nice pics. You've got some great sound coming your way!.


----------



## Scutey

kamzak88 said:


> I bought 6ZH1P
> 
> http://www.ebay.pl/itm/282297664387?_trksid=p2057872.m2749.l2649&ssPageName=STRK:MEBIDX:IT
> 
> ...


Hi Kamzak88,

Which LD do you have, have you not got the reference guide?. If you have the LD MK3 there will be a hole on the underside with two sets of red gain switches, one for right and left channels, here is the LD MK3 ref guide explaining what to do,go to page 8, hope this helps.http://195.84.101.101/~goranl/projects/nad_stereo/little_dot/LittleDot_MKII_Guide.pdf


----------



## gibosi

Yes, indeed, enjoy!

And if you can find them at a good price, the older embossed C3gs are well worth trying, IMHO. The embossed Siemens is very close to the silk-screened version, with a little less mid-range bloom to my ears. And the Lorenz is quite different, with less treble and air, and correspondingly, more bass and lower mid-range presence.


----------



## kamzak88

Scutey said:


> Hi Kamzak88,
> 
> Which LD do you have, have you not got the reference guide?. If you have the LD MK3 there will be a hole on the underside with two sets of red gain switches, one for right and left channels, here is the LD MK3 ref guide explaining what to do,go to page 8, hope this helps.http://195.84.101.101/~goranl/projects/nad_stereo/little_dot/LittleDot_MKII_Guide.pdf



I have LD I+ and I dont have manual. I know where is gain switches but i dont know how set this


----------



## dobigstuff

kamzak88 said:


> I have LD I+ and I dont have manual. I know where is gain switches but i dont know how set this


kamzak88:

If your Little Dot 1+ has the small red box (with the gain switches) when switch 1 is "on" and switch 2 is "on" that will be low gain (2.5)


----------



## dobigstuff

Use your ears.  everyone is different but usually your range on the Volume Knob is about 9:00-12:00


----------



## Ronvdp

You will love those! Completely changed my view of the LD MK3. Just getting back into the headphone thing and I’m really glad I held onto this amp. I did get a DAC which I never tried before and it is a serious upgrade to go along with the nice quality audio from TIDAL.


----------



## dobigstuff

Ronvdp said:


> You will love those! Completely changed my view of the LD MK3. Just getting back into the headphone thing and I’m really glad I held onto this amp. I did get a DAC which I never tried before and it is a serious upgrade to go along with the nice quality audio from TIDAL.



Ronvdp:

Did you also change your Power Tubes to the 6SN7's?


----------



## OctavianH

gibosi said:


> Yes, indeed, enjoy!
> 
> And if you can find them at a good price, the older embossed C3gs are well worth trying, IMHO. The embossed Siemens is very close to the silk-screened version, with a little less mid-range bloom to my ears. And the Lorenz is quite different, with less treble and air, and correspondingly, more bass and lower mid-range presence.



Ok, mine are different, I guess based on the serial number they are newer. These were the ones I could find at a decent price here. I will try them and see later if I will want also embrossed ones.


----------



## gibosi

OctavianH said:


> Ok, mine are different, I guess based on the serial number they are newer. These were the ones I could find at a decent price here. I will try them and see later if I will want also embrossed ones.



Based on your pictures, I would say that my silk-screened C3g are newer than yours. Mine came in those bright orange and blue boxes, which are definitely from the mid-1970's. Your yellow and blue boxes are older. And further, on mine, the serial number is silkscreened on top while yours have the paper band around the middle.

Regardless, they are all wonderful tubes and the differences are subtle. Enjoy.


----------



## OctavianH

I was worried that they are not identical, but I guess I have to ignore this. This guy I have received them from lives in Budapest and claims they are brand new. When the adapters will come I will try them with the Jan Philips 6SN7 WGTA. I guess this is my last upgrade for LD.


----------



## gibosi

Yours might not have been manufactured in the same month, but still given the similar boxes and labeling, I would guess they were manufactured around the same time, perhaps within a few years of each other. So for all intents and purposes, I would say yours are identical.

For example, I have a backup pair of embossed Siemens shown below. Notice that the difference in the serial numbers is quite large. And further, the one of the right has gold pins while the other doesn't. Still, swapping these tubes from left to right, I can hear no difference.



Moreover, this backup pair sounds identical to my closely matched pair shown below. So I keep the matched pair safely stored away and listen to my backup pair. 

So again, no reason to worry. I am sure that your two tubes are virtually identical.


----------



## gibosi

wendyKL said:


> Hi I'm thinking about a Little Dot I+, how does it do with IEMs? I'm looking to connect it to an Audioquest Dragonfly RED from my laptop. Also how long do the tubes take to warm up?  I'm using Shure IEMs



It looks like no one has responded? 

The Little Dot 1+ was explicitly designed for low-Z headphones, such as IEMs. So it is a much better choice for your Shure than the LD II, III or IV.

The tubes used in the LD 1+ heat up rather quickly, less than 5 minutes.

So I encourage you to go for it!


----------



## Johnnysound

Hi Gibosi !  My Siemens C3G are s/n 59737-59738, bought NOS (along with a used backup pair) from a german guy that offered the tubes in this forum a long time ago...at a quite reasonable price.  Swapping for the backup ones makes absolutely no difference in sound.  And the backup tubes are obviously much older,  have lost the band with the s/n, all that remains is a small piece of a blue/yellow sticker, as you can see... I understand C3Gs appeared in late sixties or so, and I am wondering if my backup ones are around first generation.  In any case, these are from a very different batch from the new ones, probably many years older, but sound virtually the same,  showing great consistency, and obviously great quality control in the C3gs production.  This is not very usual with many other tubes....


----------



## Topodomain

C3g's seem to get ridiculously expensive and rare. I wonder would it be possible to make adapters and heater voltage source (like in 6as7 power tube mod.) and get c3m or something similar working? Would it be safe for LD IV SE?

C3c's would look cool


----------



## Johnnysound

Searching a little bit,  the C3g was first introduced in 1952 (that's way older than I tought !) and there are C3gs with all kind of labels:  blue/yellow, blue/white, blue/yellow/white, plain yellow and even white bands with the serial number. No idea how is this related to the year of manufacture,  and C3gs have no date code,  I think it appears only in the original box. I can say that narrow, yellow bands (the most common) belong surely to later models made in the seventies, while wider blue/yellow labels can be much older. Finally,  found a pic of a Siemens C3g with blue/yellow label from 1961, positively dated.  This was a great find, because the broken labels of my backup tubes  do look really old, and now I know they are vintage units. Really nice, of course, have to hear these tubes in detail,  and even risking contradicting myself about my last post,  no seventies tube can sound as good as a late fifties or early sixties tube, I don't know why, this is just one of the tube myths...


----------



## gibosi (May 7, 2017)

Johnnysound said:


> Searching a little bit,  the C3g was first introduced in 1952 (that's way older than I tought !) and there are C3gs with all kind of labels:  blue/yellow, blue/white, blue/yellow/white, plain yellow and even white bands with the serial number. No idea how is this related to the year of manufacture,  and C3gs have no date code,  I think it appears only in the original box. I can say that narrow, yellow bands (the most common) belong surely to later models made in the seventies, while wider blue/yellow labels can be much older. Finally,  found a pic of a Siemens C3g with blue/yellow label from 1961, positively dated.  This was a great find, because the broken labels of my backup tubes  do look really old, and now I know they are vintage units. Really nice, of course, have to hear these tubes in detail,  and even risking contradicting myself about my last post,  no seventies tube can sound as good as a late fifties or early sixties tube, I don't know why, this is just one of the tube myths...



My best guess is that you are off by about a decade. 

Yes, the earliest version was introduced in the 1950's, but it has a different pin-out and is quite rare. And it won't work with the adapters available on eBay. These have serial numbers in the range, 501-10000.

Sometime after that, probably in the late 1950's or early 1960's, the final version was introduced. Outwardly, these are characterized by embossed flat-black cans. As best I can tell, Telefunken, Lorenz and Siemens manufactured these tubes. (However, I have never seen a Telefunken C3g with an embossed flat-black can.)

By the 1970's, Telefunken and Lorenz had shut down their production lines and only Siemens manufactured the C3g. 1970's production is characterized by silk-screened shiny-black cans. (And if you closely compare the 1960's and 1970's Siemens, pictured below, you can see other small differences in the shape of the can.) To my knowledge, every C3g with these shiny-black cans was manufactured by Siemens, regardless of the silk-screened brand printed on the tube.

To my ears, the later 1970's Siemens have a touch more mid-range bloom than the 1960's Siemens, but this difference is very subtle.


----------



## gibosi

Topodomain said:


> C3g's seem to get ridiculously expensive and rare. I wonder would it be possible to make adapters and heater voltage source (like in 6as7 power tube mod.) and get c3m or something similar working? Would it be safe for LD IV SE?
> 
> C3c's would look cool



Yes, compared to the standard recommended LD tubes, C3g are expensive. However, compared to other premium tubes used in audio, such as 6AS7, 6SN7 and 6DJ8, they are not ridiculously expensive. A pair of C3g can often be found for around 100 US dollars. Premium double triodes (equivalent to a pair of C3g) often go for hundreds of dollars. Further, these are 10,000 hour tubes, so two pairs will very likely outlast your amp. 

As to running a C3m? Sure. As the old adage goes, "If there is a will there is a way." 

First, you would need to be provide the tube with 20 volts to heat it. Second, the pinout is completely different than a C3g, so you would need to built a custom adapter, 8-pin loctal to 7-pin miniature, to reroute the pins. This should not be all that hard to do, but would the end result be worth the required time and treasure? I have no idea....


----------



## OctavianH

Two pairs? Do you mean like use C3G also for the power tubes? What I have tried was to put C3G as driver + 6SN7 as power tubes, but I see that these 6SN7 are usually found on other amps in driver position. It is not very clear to me what to choose best as power and what to choose best as driver....


----------



## gibosi

The C3g is not suitable for use as an output tube. What I am suggesting is one pair for daily use as drivers and a second pair for backup. And given their 10,000 hour life time, it is likely that they would never need to be replaced.

Yes, 6SN7 are often used as drivers in other amps. However, these amps typically use the 6AS7 as an output tube, which draws 2.5A of heater current and is much more powerful than the 6H30-types recommended for the LD. The LD cannot use the 6AS7 without serious modification, including an external heater power supply, and in my opinion, upgrading key resisters on the circuit board to handle significantly more DC current.

I suggest that it is best to respect the design limitations of the LD and use output tubes drawing at most 0.9A of heater current. The 6SN7, which draws 0.6A works well with efficient high-Z cans. For less efficient low-Z cans, output tubes requiring more heater current, up to 0.9A, such as the 6H30 or the 5687 (which draws 0.9A) will work better. And if money is no object, the Mullard ECC32, which also draws 0.9A, would be a good choice.


----------



## OctavianH

Thanks gibosi for your help and explanations. Unfortunately the new design of the forum, which I have to say does not please me very much, does not have the Thanks button but a Like one. This new design adds too much advertising and looses the simplicity of the other one, or maybe I am too old to accept changes anymore.
Anyway, I will stick than to the plan of C3G as drivers + 6SN7 as output for my T1. Impedance should not be a problem.


----------



## gibosi

Yes, the new design doesn't please me either...  The link below provides some explanation regarding "why?"

https://www.head-fi.org/f/threads/why-we-switched-forum-platforms.846861/


----------



## TrollDragon

gibosi said:


> Yes, the new design doesn't please me either...  The link below provides some explanation regarding "why?"
> 
> https://www.head-fi.org/f/threads/why-we-switched-forum-platforms.846861/


I am on two other major forums that use the Xeno software. One has 260M users and 17B messages, both are very easy to navigate and use.  It would be great if Head-Fi brought in a programmer to get the site tweaked properly for better use, rather than a learn as you go type thing.


----------



## kamzak88 (May 10, 2017)

I have LIttle DOt with 6J1P-EV tubes.

And i have some questions:
1. How long does it take to light up the tubes?
2.I have as source AIM808 card and ordered the 2x LME49720NA + LM6172IN.
Will the AIM with LD in conjunction with the sr325 be too insecure now, and what will the retail "disappear"?
3. This is *Mullard CV131/6CQ6 ?
http://www.ebay.pl/itm/162417262921?ssPageName=STRK:MESINDXX:IT&_trksid=p3984.m1436.l2649*


----------



## OctavianH

My adapters just arrived. I think I might try them today or latest tomorrow. But before that, I am wondering if it makes sens to test them somehow.
Can they damage in any way the LD? Or just plug-n-play and nothing bad can happen?


----------



## gibosi

OctavianH said:


> My adapters just arrived. I think I might try them today or latest tomorrow. But before that, I am wondering if it makes sens to test them somehow.
> Can they damage in any way the LD? Or just plug-n-play and nothing bad can happen?



If you want to check them, use a multimeter to see if there is continuity between the socket holes on top and the associated pins on the bottom according to the pin-out diagrams on the datasheets.

http://drtube.com/datasheets/ecc88-philips1958.pdf

http://www.nj7p.org/Tubes/PDFs/Frank/093-GE/6SN7GTB.pdf

https://frank.pocnet.net/sheets/190/c/C3g.pdf

But in my experience, even if the adapter is defective, nothing bad happens. Either the tube heats up and plays or it doesn't. And if it doesn't, then you might want to pull out the muitimeter to see which connections are bad.


----------



## OctavianH (May 15, 2017)

It seems I need some help. I mounted the adapters and the new tubes, but I hear a quite loud buzz in the headphones, more pregnant in the left channel.
I assumed it is related to the power tubes, so I replaced them with the old 6N6P-IR and the problem seems solved. I switched them left-right and the buzz remained in the same form (I was expecting to move to right channel). I switched Jan Philips 6SN7WGTA with russian 6HC8 and the same.
So the tubes seem fine, the adapters seem fine... what is the problem?


----------



## J Mirra

The buzzing happens with the C3g's on my LDMK11 in low gain, mid and high do not display the symptoms.


----------



## OctavianH (May 15, 2017)

So question, should I switch to high gain? Will damage the sound in any way? Because yes, I remember I let it to low gain.

These C3G need burn in like other normal tubes?

Later edit:

It seems I have solved the mistery via Gain settings. But I think mine was on high gain and now it is set to low. I mean both jumpers are towards 1 and 2 and not ON on the switch:






Before both were towards ON (which I think is high gain according to the manual)
Even the volume knob now is lower for the same output level. Anyway, many thanks for help.


----------



## J Mirra (May 15, 2017)

Depends on your headphone impedance and also how you like the sound, high gain can add tad more slam and sparkle.

I have the monoprice M1060 and they like high gain even though the are 50ohm.

Med gain is also good.

Mine sounded great right away, I would say after 30 minutes of every listening session they start to really sound their best for me.


----------



## OctavianH (May 15, 2017)

I use T1 here, 600Ohm, but the only Gain setting which does not buzz is this one. So I think it is a kind of "take it or leave it". I have no choice of setting the gain in other way.
Another option would be to replace 6SN7WGTA with 6N6P-IR but I want to try these new ones to see what is happening.

Last but not least, a picture with the "monkey":


----------



## J Mirra

High gain for the T1 anyhow which I also have (T1.1)

Seems like its the adaptors making the issue.


----------



## OctavianH

Might be the adapters but I have no idea what I can do to them...


----------



## kamzak88

Is it worth to exchange stock oamp LD on OPA2107AP http://allegro.pl/show_item.php?item=6673849042

At this moment I have 6ZH1P-EV, sometime M8161 or 6CQ6 

Which Mullard ebay deals are worth paying attention to?


----------



## dobigstuff

OctavianH said:


> Before both were towards ON (which I think is high gain according to the manual)
> Even the volume knob now is lower for the same output level. Anyway, many thanks for help.


Octavian:
The Gain in the Manual for the MK II is the Same as the MK III.
Switch 1 & 2 OFF = Gain 10
Switch 1 ON, 2 OFF = Gain 5  
Switch 1 OFF, 2 ON = Gain 4
Switch 1 & 2 ON = Gain 3
Possible Buzzing due to high Gain?
Yes the C3G's need to break in as do your 6SN7's


----------



## gulakpii

OctavianH said:


> Might be the adapters but I have no idea what I can do to them...



Do you have a multi-tester?
If so, I suggest to try Gibosi's suggesting!


----------



## J Mirra

The buzz if it is the same as mine in low gain is not a ground like hum it is a full on loud as hell buzz in one channel.

It only does it in low gain though any other combo of switches it is fine.


----------



## OctavianH (May 16, 2017)

dobigstuff said:


> Octavian:
> The Gain in the Manual for the MK II is the Same as the MK III.
> Switch 1 & 2 OFF = Gain 10
> Switch 1 ON, 2 OFF = Gain 5
> ...



Yes, now both my 1 & 2 switches are pointing towards  OFF so I have Gain 10 (for low impedance).
In the past, when the buzzing was occuring I had them towards ON which means Gain 3.



J Mirra said:


> The buzz if it is the same as mine in low gain is not a ground like hum it is a full on loud as hell buzz in one channel.
> 
> It only does it in low gain though any other combo of switches it is fine.



Yes, it is that kind of buzz, like you describe, and it is gone with Gain = 10.

OK, so my preliminary conclusions are:
- related to Gain and adapters
1) the output tubes (6SN7) work fine only on Gain = 10
2) the sound changed somehow changing the Gain from 3 -> 10
- related to overall sound
1) Siemens C3G + Jan Philips 6SN7WGTA => clean but somehow harsh and metallic, perfect ballance of tonality
2) Siemens C3G + 6N6P-IR => clean but a little bit too cold (need more bass here)

I will try today some 6H8C in the output, too see if the harshness goes out.
What I described at 1) might be related also to lack of burn-in but I think that Gain settings are also affecting the sound somehow.

Some guys talking about gain settings influence:
https://www.head-fi.org/f/threads/little-dot-mk-iii-gain-settings-affect-sq.410545/

And yes, I think they are right, so I might give up the 6SN7 only to put back Gain = 3.

My overall best setup remains Voskhod 6J1P-EV + 6N6P-IR but I still dig into these C3G because they have great potential co redefine my taste.

PS. I realize that MK2 has a problem because you need to open it every time for adjustment of the gain settings. The screws already are damaged and I will need soon to replace them. I would need to have a mixture of MK2 and MK3: an amp without any rings and with direct accessible gain switches.


----------



## J Mirra (May 16, 2017)

I have left my screw's out for easy access 1& 2 off is high gain.

I always have to bump the EQ in the 30Hz bass on my T1.1, M1060 and MDRMA900's with any tube config, I like a warm sound signature.

Edit : What I noticed with the C3g's and 6N6P-IR combo over the Mullard 8100 and 6N6P-IR is that I could turn the volume louder with complete coherence, no harshness I have never had that before it would always get to harsh.

The separation and sound stage is just brilliant as well, give them time


----------



## OctavianH

I will definitely give them time, but I think that if 6SN7 will not change, I will stick back to 6N6P-IR because I saw no real improvement.
C3G will remain there for some time to see what is happening.


----------



## J Mirra

I am running C3g with the 6N6P-IR and it is definitely an upgrade in quality, sounds great with the T1.1 and the Monoprice M1060 I am really happy with my purchase.

Once the C3g have had some time to open up then you will hear what I do I am sure. At first I was the same thinking I am not sure there is a difference but relaxing and turning it up a little more than I used to yielded the results I hoped for.


----------



## OctavianH

Ok, back to Gain = 3 and 6N6P-IR in the output. The sound is more "natural" than with the 6SN7 which was somehow muffled. I will let the C3G for a few days to see if they improve because at the moment they are behind the Voskhods.
The sound is a little bit harsh and I still have the problems with the "cymbals" which I had with M8161. We will see, this was my last investment on MK2 because I do not really see what I can do more. If C3G remain like this I will which back to Voskhods and leave them there forever. Best sound for my taste.


----------



## J Mirra

If you do not get on with the C3g let me know if you do not mind and I would buy them from you.


----------



## TrollDragon

I'll just leave this here, quoted from the DIY Audio forums where people were discussing the sound characteristics of tubes...

_



			A tube doesn't make a sound, it only has a transfer curve that must be considered before designing a circuit and running signals through it. Most "tube rollers" haven't got the foggiest idea how a tube really works, or what the transfer characteristics mean.

A bad sounding tube is simply one used in a circuit that wasn't designed for it. It really is that simple.
		
Click to expand...

_
So when tubes sound "muddy" or "harsh" it is not the tube that sounds that way, but it's improper use in a circuit that doesn't meet the design requirements of the tube.


----------



## OctavianH

I played with 6SN7 and gain settings again, and the conclusion is that on MK2 on Gain = 5 and Gain = 10 we have no buzz with 6SN7 on output. With Gain = 3 we have a significant buzz, and with Gain  = 4 a reduced one, but still hearing. If no one complained about this on MK3 it seems that its PCB does not behave identically, which makes me wonder on other differences between MK2 and MK3. I will leave the Gain = 5 and see how the sound changes during some listening hours.


----------



## waflet

TrollDragon said:


> I'll just leave this here, quoted from the DIY Audio forums where people were discussing the sound characteristics of tubes...
> 
> 
> 
> So when tubes sound "muddy" or "harsh" it is not the tube that sounds that way, but it's improper use in a circuit that doesn't meet the design requirements of the tube.


Hideeho
LOL!
That reminds me of the difference between a scientist & an engineer...


----------



## i luvmusic 2

TrollDragon said:


> I'll just leave this here, quoted from the DIY Audio forums where people were discussing the sound characteristics of tubes...
> 
> 
> 
> So when tubes sound "muddy" or "harsh" it is not the tube that sounds that way, but it's improper use in a circuit that doesn't meet the design requirements of the tube.



This is so true i have used 6SN7 with all my amps but none are designed for it,The 6SN7 works/sound good with all my amps so i thought these tube is really good until i build these amp(see pictures)that is designed to run 6SN7 and WOW! these tube really shine it sound much much better than before.


----------



## TrollDragon (May 18, 2017)

i luvmusic 2 said:


> This is so true i have used 6SN7 with all my amps but none are designed for it,The 6SN7 works/sound good with all my amps so i thought these tube is really good until i build these amp(see pictures)that is designed to run 6SN7 and WOW! these tube really shine it sound much much better than before.


Exactly!

Sweet looking amp, nice build!


----------



## i luvmusic 2 (May 18, 2017)

TrollDragon said:


> Exactly!
> 
> Sweet looking amp, nice build!



The beauty of this amp i can use 6/12SN7.Thanks!


----------



## Hefeweizen

I have a question on the 6N6p-IR power tubes.   I am getting black "burn" marks on the sides of the tube.  Is this normal?  The entire MK2 seems hot after a while.   I am not getting any black burn marks using standard 6N6P gold grids. I will attach a few pictures for detail.  

    

 Thanks!


----------



## gulakpii

These black "burnt" marks came with the tubes during manufacturing on mine.  You probably just didn't notice them before.  
If you check the pictures they post on new tubes, you'll see them there!


----------



## Hefeweizen

Thanks.  I have a few more sets coming.  I will look over each carefully.     They do look like heat or burn marks though.


----------



## OctavianH

Mine look the same, and I observed them before using the MK2. I used here 3 months 6N6P-IR without problems so I guess they are fine.


----------



## i luvmusic 2

I do have a 6SN7 that developed that burnt marks it still working fine after all tubes gets really hot,Just my opinion i'am not a tube expert.


----------



## kamzak88

Hi I have a question. CV4015 (mullard m8161) and CV131 (6Cq6) are the same tubes?


----------



## TrollDragon

kamzak88 said:


> Hi I have a question. CV4015 (mullard m8161) and CV131 (6Cq6) are the same tubes?


Yes, Radiomuseum says they are basically the same tube.
http://www.radiomuseum.org/tubes/tube_cv4015.html
http://www.radiomuseum.org/tubes/tube_cv131.html


----------



## gibosi

For all intents and purposes they can be considered the same. The CV4015 is a special quality ruggedized version of the CV131. That is, it was designed to withstand severe vibration and shock allowing it to be used in difficult military and industrial operating conditions. Assuming that your Little Dot is not being used in such an environment, there is no advantage to using a CV4015 over a CV131.


----------



## kamzak88

so why such a different 

"*2.3 Mullard CV131/6CQ6*

These are very nice sounding tubes with a laid back character that feels like you’re sitting a few rows back from the center of a concert hall. Keeping with the typical Mullard family sound, these tubes emphasize warmth and fullness, a characteristic I find very complimentary for my collection of Grado headphones. Bass quality is excellent in terms of texture and nuance, this is toe-tapping bass without being overpowering. Overall these are very nice tubes with no obvious faults and much to love.
                Bass: 17
                Mid: 18
                Treble: 16
                Detail: 14
                Soundstage: 16
                Total: 81/100

*2.4 Mullard M8161/CV401*

Focus is the word. This mil-spec version of the Mullard CV131 is one of the best sounding EF92 tubes around. It brings to the table all of the fine qualities of the Mullard CV131 and adds to it a background so extraordinarily quiet you will actually _notice_ the silence between notes. A low noise floor lets details stand out, and music with female vocals in particular is presented with a magical sense of focused intimacy that draws you in and makes you feel as if the singer is standing right next to you, singing into your ears with all the inflections and emotions preserved. Overall this tube is well balanced and ‘audiophile’ sounding and is one of my personal favorites.
                Bass: 19
                Mid: 18
                Treble: 19
                Detail: 20
                Soundstage: 19
                Total: 95/100
 "

??


----------



## TrollDragon

kamzak88 said:


> so why such a different
> 
> "*2.3 Mullard CV131/6CQ6*
> 
> ...


A very subjective description of a pair of tubes. 
If you use the exact same tubes that he had for that trial, you might get similar results. 

Don't forget that 95% of all the tubes we use in the LD as drivers were designed for high frequency RF & IF circuits. It's a bonus that we can strap these pentode's to run as a triode's and use them for audio purposes.


----------



## gibosi (May 22, 2017)

And I would add.... Tubes manufactured at different times and in different factories often sound different. That is, tubes manufactured in the 1950's often sound different than those manufactured later, even in the same factory. Plus, tubes manufactured in different factories owned by different companies typically sound different. For example, Mullard is not the only manufacturer of these tubes. I have also seen CV131 manufactured by STC, Brimar, British Mazda (Ediswan) and MOV.

IMHO, unless we know precisely which tubes -- factory and date of manufacture -- are being compared, as well as the other equipment in the reviewers system, I suggest one should not take these reviews too seriously.

And given that the prices are not exorbitant, I would encourage you to try Brimar, STC, MOV, Mazda and Mullard versions of these tubes to see which sound best in your system with your ears.


----------



## kamzak88

Thanks for advice and information


----------



## OctavianH

Ok guys, I spent 10-15 hours to evaluate the C3G in conjunction with Jan Philips 6SN7 via adapters. Gain set to 5 to avoid the buzz (minimum value for this). My final statement is 9/10.
I tried then C3G with 6N6P, 6N6P-IR, Gain = 3 and I think the score remained close. So the output tubes do not really make a difference here, or I have bad ears and I do not sense it.
I tried also the 6HM5 in conjunction with 6N6P=IR and the score was 8/10. Quite good, nice surprise. But in the end I put my Voskhods near the same 6N6P=IR and the score was 10/10.
The magic was back. The perfect balance of what I need. So I will keep these ones and the others in a box. I will not sell anything at the moment because the pleasure of rolling them remains.
So I am one of those crazy guys who prefer Voskhod over the C3G. Hell knows why when all arguments and science contradicts me.


----------



## kamzak88

Does anyone know what is the difference in the Voskhod 6J1P-EV Gold-platinum grid. MIL SPEC!
http://www.ebay.pl/itm/6ZH1P-EV-6J1...286102?hash=item25d7248a56:g:RKcAAOSw9OFZIKZD

or

http://www.ebay.pl/itm/Matched-pair...ittle-dot-/131990927882?hash=item1ebb45ba0a:g : Yp4AAOSwHMJYGftE

  And ordinary

http://www.ebay.pl/itm/282297664387?_trksid=p2057872.m2749.l2649&ssPageName=STRK:MEBIDX:IT

And what sound difference is in the '70 a '80 vintage


----------



## Whelkie D

OctavianH said:


> Ok guys, I spent 10-15 hours to evaluate the C3G in conjunction with Jan Philips 6SN7 via adapters. Gain set to 5 to avoid the buzz (minimum value for this). My final statement is 9/10.
> I tried then C3G with 6N6P, 6N6P-IR, Gain = 3 and I think the score remained close. So the output tubes do not really make a difference here, or I have bad ears and I do not sense it.
> I tried also the 6HM5 in conjunction with 6N6P=IR and the score was 8/10. Quite good, nice surprise. But in the end I put my Voskhods near the same 6N6P=IR and the score was 10/10.
> The magic was back. The perfect balance of what I need. So I will keep these ones and the others in a box. I will not sell anything at the moment because the pleasure of rolling them remains.
> So I am one of those crazy guys who prefer Voskhod over the C3G. Hell knows why when all arguments and science contradicts me.


I love the Voskhods with the 6N6P, but found them too harsh with the 6N6P-IR. Anyone else had this?


----------



## OctavianH

It depends on the rest of the setup. For me 6N6P have too much bass because T1.2 are a kind of T1 V-shaped (or at least the bass is enhanced). The 6N6P-IR perfect balanced, no harshness and anything.


----------



## kamzak88

what i choose? 

gold platinum grid MILspec http://www.ebay.pl/itm/162523286102?_trksid=p2060353.m1438.l2649&ssPageName=STRK:MEBIDX:IT
or
silver grid http://www.ebay.pl/itm/252143894112?_trksid=p2060353.m1438.l2649&ssPageName=STRK:MEBIDX:IT

The best for LD+ (with oamp 2107) and grado?


----------



## Whelkie D

Anyone know anything about this?????
http://www.elusivedisc.com/The-Tube-Only-Violin-Hybrid-Stereo-SACD/productinfo/TACSA117/
It says; " veritable audiophile delicacy - lovingly preserved historic microphones, a mixing desk consisting of nostalgic V72 amplifiers and W85 regulators, the analogue M5 Telefunken tape recorder - each item a legend in itself! Tacet proudly presents this illustrious combination of equipment, here to preserve beautiful music “TUBE ONLY”, in other words without transistors."


----------



## OctavianH

So the C3G saga continues. I upgraded my T1.2 with a new cable made by some guys at Custom Cans (UK). This new cable brought me less highs and more bass. Or at least this is the initial impression.
Because of the new cable, I needed a tube change and somehow I decided to try again the C3G with the Jan Philips 6SN7 on the output and Gain set to 5. And what to say, it is a quite big improvement over my last session with them.







So a cable changed my stuff here. I will let these a while and try to see if some burn in of the C3G and also of the cable will make me put this combination on position #1.
Until now, this setup using C3G is better than the previous one, and the only change is a headphone cable. Incredible.
Anyhow, this cable is really nice and flexible, and it has only 1.5m length, which suits me better.
The stock cable had 3m and I had to keep it rolled because it was too long. And judging by the price, Beyer stock cables are usually expensive, so a custom one is no big difference.


----------



## simon740

Hello,

What do you guys think about LD MK2 with these tubes: https://www.watfordvalves.com/product_detail.asp?id=4218
Such a combination would be OK for the HD800?

regards,
Simon


----------



## DjBobby

simon740 said:


> Hello,
> 
> What do you guys think about LD MK2 with these tubes: https://www.watfordvalves.com/product_detail.asp?id=4218
> Such a combination would be OK for the HD800?
> ...


I have this combination, but not HD800. It works splendidly with HD650.


----------



## Johnnysound (Jun 20, 2017)

[/ATTACH]


----------



## Johnnysound (Jun 20, 2017)

Little Monster:  LDIII with Siemens C3Gs and RCAs 6AS7G, ext power supply


----------



## OctavianH

Those socket savers are available somewhere in Europe to order? Because for that value I do not see a reason to order them in US and pay double value for shipping.


----------



## controllerboy

Hello

I'm quite new at this while tube rolling thing, but my grandparents seem to have quite a collection of tubes from the old days and I want to test them all.
I've also ordered some '70s Voskhod 6N23P tubes to use in both my Little Dot and my Hifiman EF2A.

Anyways, I found that it's possible to create an adapter to use one 9-pin tube in your otherwise exclusively 7-pin device (the Hifiman). 
I've already ordered a "B9D 9 Pin Tube sockets experiment" broadboard for a reasonable price. (here)

I understand that I now need two socket savers/tube testers with 7 pins and attach wiring from the leads on the top of both socket savers to attach to the indicated places on the breadboard on which I mount the 9-pin tube. 

Something like this:






Anyhow, even after hours of searching, I haven't found a single pair that's affordable. If I recall correctly, I can't even find a pair of similar adapters at all!

Would someone perhaps know a place where they can be had cheaper? I really want to swap different types of tubes, but this is just an experiment for me. I don't want to spend big $$ on something I mightn't use in the future...

Thank you!


----------



## gibosi

Radio Daze doesn't seem to have these 7-pin test sockets anymore and I am not aware of another source. It is certainly possible that a pair might pop up on eBay, but it is impossible to know when. So in the end, if you can't purchase a pair, you might want to build a couple as outlined in this youtube video:



Good luck and have fun!


----------



## Johnnysound

You can try Leeds Radio, they used to have both 7 and 9 pin socket savers...
https://www.etsy.com/listing/213863...y=7+pin+socket+savers&ref=shop_items_search_1


----------



## gibosi

The last time I checked Leeds Radio stock, this is the 7-pin socket saver they had. I tried to solder wires to the wire pins extending out of the top, but didn't have any luck.

 

I used these to reroute the pins to allow me to run other pentodes, such as the 6AH6, However, it just might be possible to disassemble the saver, solder some wires to the pins inside and then route them out the top, But given that I had the Radio Daze test sockets, I didn't bother trying....


----------



## controllerboy

Thanks to both of you for the very speedy replies. 

I'm in no hurry since it'll take at least a month for the breadboard to arrive. I'll keep cheking ebay and when I see nothing comes along, I'll try to find some time to make two of my own.

Greetings

Jan Mestdagh


----------



## smashing

Quick question, are the power tubes for the LD III+ the same as the Mk III? 

My power tubes are starting to give me some issues on the LD III+ with buzzing and occasional absence of sound from one channel. I'm trying to find the specs for replacements.


----------



## gibosi

smashing said:


> Quick question, are the power tubes for the LD III+ the same as the Mk III?
> 
> My power tubes are starting to give me some issues on the LD III+ with buzzing and occasional absence of sound from one channel. I'm trying to find the specs for replacements.



It appears that the LD III+ was manufactured around 10 years ago and as best as I can determine, it came with 4P1L / 4L1S / RL2 / 4P6 installed as power tubes. Unfortunately, the current MK III uses very different tubes.

If my conclusions are correct, search eBay for 4P1L.

Good luck!


----------



## smashing

gibosi said:


> It appears that the LD III+ was manufactured around 10 years ago and as best as I can determine, it came with 4P1L / 4L1S / RL2 / 4P6 installed as power tubes. Unfortunately, the current MK III uses very different tubes.
> 
> If my conclusions are correct, search eBay for 4P1L.
> 
> Good luck!



I was surprised to find the rather odd configuration from the power tubes and have the nagging suspicion that it's not the same as the Mk III. Thanks for pointing me with the right configuration. 
Apparently the stock tube were Beijing made 4P1S. I'd probably get something similar from taobao (cheap!), and message sword_yang to see if there's other compatible tubes for the model. 

And yar, I'd gotten my LD III+ for ten years now and it's still running fine (except for the recent problem with the power tube). So the craftmanship is definitely something to write home about.


----------



## c0d3r (Jul 15, 2017)

Hi to you all.

First of all let me thank you all for this amazing thread about the Little Dot.
My adventure started with a USB DAC 2 weeks ago, that in the last 3 to 4 days, with the help from this thread made me jump to a CHORD Mojo, a pair of YU6 Speakers, and a LD MK 2 !! ( USB DAC sent back )
I need to stop reading it, or I'll end up living under the bridge lol !

I was quite impressed with the Stock Tubes,very good sound indeed.
Got a new pair of CV4015 already installed, and I'm waiting for the Power Tubes 6N6P, and a pair of driver tubes 6J1P-EV to arrive.
Will replace the Power ones with the 6N6P, but not sure about the driver ones, as I'm really loving the clarity of the sound from the CV4015.
Can be on the speaker or the K702 headphones, the sound is just crazy.
LD MK2 gives the valve/tube touch to the already super amazing Mojo sound.
It's like listening to an all new collection of music !

Ok, this, was really to just say Thank you all !!


----------



## controllerboy

After your instructions, I made some tube adapters and soldered some wires, which I connected to the breadboard. Confirmed working on Hifiman EF2A! I do need to dial up the (normally immensely overpowered ) gain to around the maximum as well as the volume on my Macbook to get a decent output on my Sennheiser HD800's.

I suspect the tube could use some extra power since it doesn't get anywhere near warm and doesn't give off any glow.


----------



## i luvmusic 2

I do not suggest leaving those exposed metals/terminals like that LETHAL VOLTAGE/CURRENT is flowing through those terminals.Be safe!


----------



## TrollDragon

i luvmusic 2 said:


> I do not suggest leaving those exposed metals/terminals like that LETHAL VOLTAGE/CURRENT is flowing through those terminals.Be safe!


The EF2A runs off of a 16V wall wart, there is nothing lethal on those pins...


----------



## TrollDragon

controllerboy said:


> After your instructions, I made some tube adapters and soldered some wires, which I connected to the breadboard. Confirmed working on Hifiman EF2A! I do need to dial up the (normally immensely overpowered ) gain to around the maximum as well as the volume on my Macbook to get a decent output on my Sennheiser HD800's.
> 
> I suspect the tube could use some extra power since it doesn't get anywhere near warm and doesn't give off any glow.


It's hard to say what the issue is without knowing what the new tube is or how you have it wired, the tubes in the EF2A are only preamp tubes as it is a hybrid amp.  
I am surprised you use it with the HD800's, I read that the amp has some really bad channel separation and a poor volume control.


----------



## i luvmusic 2

TrollDragon said:


> The EF2A runs off of a 16V wall wart, there is nothing lethal on those pins...



Oops!Did not know that so it's not a REAL tube amp....

Thanks!


----------



## controllerboy (Jul 17, 2017)

I just got a really nice deal on the amp, just like I did on th HD800's. It was my first experience with tubes and I really like it, even tho I know the volume control has WAY too much gain. Channel seperation is decent enough for me, but then again I have nothing better to compare it too.

I'm thinking of upgrading to a Schiit Lyr or Valhalla or a Little Dot MKIII. I'm just waiting for a good deal somewhere, preferably second hand. I just don't have the deep pockets some of the people on this board seem to have


----------



## brownstd (Jul 21, 2017)

c0d3r said:


> Hi to you all.
> 
> First of all let me thank you all for this amazing thread about the Little Dot.
> My adventure started with a USB DAC 2 weeks ago, that in the last 3 to 4 days, with the help from this thread made me jump to a CHORD Mojo, a pair of YU6 Speakers, and a LD MK 2 !! ( USB DAC sent back )
> ...


If you are new to this "tube" thing watch out...I thought I was addicted to headphones until I discovered tubes... very very dangerous
Glad to see you are liking the MK 2.  I've had a 1+ for years (and thanks to this forum I've gone through quite a few opamps and rolled endless numbers of tubes). That led me to the Dark Voice where I discovered the wonders of the 6SN7 family of tubes.

I purchased a MK2 on a whim from Massdrop about a year ago. I swapped out the power tubes for a pair of Novo 6N6p-IR's (again thanks to this forum) and planned on using it as a bedroom amp. I have to say, I was initially underwhelmed...until...I read about the c3g tube (search this forum for an in-depth discussion).

The c3g tube (used as a driver tube with a c3g to 6AK5 converter, which is readily available on eBay) is beyond phenomenal. Shockingly good. Blows away ANY driver tube I've used for the Little Dots (including the Sylvania gold pins or Voshkods).

While I prefer the Darkvoice for my HD650's, the MK2 with the c3g tubed has become my amp of choice for many of my other headphones. The k702's pairs especially well. Even my heavily modded Fostex TR50rp's sound fantastic (with the exception of the MK2 with the c3g tubes, I've found that planar magnetic and orthodynamic headphones do not pair well with tubes).

The c3g tubes are pricey (there are some on eBay at the moment for $99... I've gotten them for as low as $65) and the adapters add about another $35. While I generally wouldn't recommend spending so much on a pair of tubes for an amp that costs around $130, I STRONGLY recommend the investment (as others in this forum have). The c3g tubes are very special and unique tubes that will pay off in spades.

BTW... while I have few posts to my name I am an avid reader of many forums here. I greatly appreciate what so many of you have taught me (although my wallet, wife and fatigued mind and body... from lack of sleep...do not  ).


----------



## J Mirra

I too Bought the C3g's after reading this thread, it has been really hot here in the UK lately so I stopped using the LD MK11 to keep the room temp down.

The next morning I woke to listen to music even though the night before I felt like the music sounded fine something was not pulling me into the music.

Fired up the LD MK2 with the C3g's and there is was music playing at me from in front of my head like a speaker in that liquid 3D format I was amazed once more.

So glad I read this thread and recommend them to anyone who has the chance to try them, music is my life and this has made music listening so much sweeter.


----------



## c0d3r

brownstd said:


> If you are new to this "tube" thing watch out...I thought I was addicted to headphones until I discovered tubes... very very dangerous
> Glad to see you are liking the MK 2.  I've had a 1+ for years (and thanks to this forum I've gone through quite a few opamps and rolled endless numbers of tubes). That led me to the Dark Voice where I discovered the wonders of the 6SN7 family of tubes.
> 
> I purchased a MK2 on a whim from Massdrop about a year ago. I swapped out the power tubes for a pair of Novo 6N6p-IR's (again thanks to this forum) and planned on using it as a bedroom amp. I have to say, I was initially underwhelmed...until...I read about the c3g tube (search this forum for an in-depth discussion).
> ...




Ok, decided !

This forum thread will be my complete ruin ! haha

Thank you for your advice, and be sure that Ill take a look onto what you just said.  

At the moment I have installed on my MKII,
the 6N6P Power valves – NOS Soviet from 1979 and the USSR military spec 6J1P-EV Voskhod from 1987.
I'm giving the CV4015 MULLARD NOS a free holidays. 

Once again, thank you all !

My Mojo, with this fella and the YU6 speakers are a match made in heaven !

Cheers,


----------



## gulakpii

You will not regret, I'm sure!  
This can be the best investment you ever had!


----------



## gulakpii

But make sure you handle the C3g's with utmost care!
They are extremely fragile mechanically (than most other tubes)!


----------



## c0d3r

Hi guys,

Now, I got really confused.
I was searching through ebay, and I did find the 6AK5, but it says, 6AK5 EF95, so, if this is a EF95, then I don't need any adapter, as its just plug in, my Little Dot MK II is compatible with the E95, the 6J1P-EV I'm using now are EF95.
So, is ebay wrong, is it me, or is both of us. Or none. lol


Cheers,


----------



## gibosi

The Radio Museum site can be very helpful in determining equivalents:
http://www.radiomuseum.org/tubes/tube_6ak5.html

~~~~~~~~
Identical to    6AK5 = EF95 = 6Ж1П = 6069 = 6F32V = 6F32 = 403A = 731A = PM05

Similar Tubes  

Other shape (e.g. bulb type):
  CK604A

Normally replaceable-slightly different:
  6AK5A-TS ; 6J1

Other class quality (otherwise equal):
  5654 ; 6AK5W ; 6J1-Q ; CV850 ; GL-5654 ; M8100
~~~~~~~~~

I am not sure what tube you are referring to, but you can run any of the above tubes using the EF95 setting, without adapters.

If you are talking about the C3g, compared to the EF95/6AK5, it has a different base and different connections and definitely requires an adapter. However, with an adapter it is pin compatible with the EF95.


----------



## c0d3r

gibosi said:


> The Radio Museum site can be very helpful in determining equivalents:
> http://www.radiomuseum.org/tubes/tube_6ak5.html
> 
> ~~~~~~~~
> ...




Thank you gibosi !

I think I was confused with the references. ( noob alert ! ) lol
Ill dig a lot more, and take a look at the link you just posted.


Cheers


----------



## Topodomain

Should Russian 6h8c tubes work as power tubes in IV SE? I have pair of those with adapters, but can't get anything out of them.


----------



## gulakpii

Topodomain said:


> Should Russian 6h8c tubes work as power tubes in IV SE? I have pair of those with adapters, but can't get anything out of them.



I'm using the 6H8C, 6N8S and other 6SN7 on adapters as power tubles on my Mk4SE.  
They work well when coupled with my HiZ cans.   Not recommended for phones with <100 ohm impedance, you will hear distortions at peaks.


----------



## Topodomain

Hmm, that's odd. Maybe my tubes are busted or adapters are not what they should be. I'll have to find out pinouts and at least measure adapter.


----------



## Tony51

Dept_of_Alchemy said:


> *[size=18.0pt]5. CONCLUSION[/size]*
> *5.1 Can’t Decide Which Tube to Buy?*
> 
> To Little Dot’s credit, their Mk-series amps have an impressive number of tube rolling options and there are more than a few very informative threads dedicated to this topic.  I would recommend anybody interested in upgrading their stock tubes to take advantage of our collective knowledge and take a look at those threads.  Occasionally I have received PMs from new members who are overwhelmed by the sheer number of tube rolling options, and asked for my recommendations so they can stop reading forums and get back to listening to their music.  So here’s my short list: I would recommend the Voshkod 6ZH1P-EV as the best place to start as it is a clear upgrade from the stock tubes, followed by the Mullard M8083 for its impressive treble clarity and top-octave ‘air’ (provided you have matched power tubes). The RCA 5654 (black plate) is also a wonderful option for its solid all-around performance, great bass response and availability.
> ...


I have just replaced the chinese junk drivers on my LD mk2 for the Jan5654w Drivers, what a great difference in sound. However i am a little confuse on the power tube, which do you recommend?


----------



## MIKELAP

Tony51 said:


> I have just replaced the chinese junk drivers on my LD mk2 for the Jan5654w Drivers, what a great difference in sound. However i am a little confuse on the power tube, which do you recommend?


These power tubes were very popular http://www.ebay.com/itm/6N6P-IR-ECC...e=STRK:MEBIDX:IT&_trksid=p2055119.m1438.l2649


----------



## MIKELAP

[


MIKELAP said:


> These power tubes were very popular http://www.ebay.com/itm/6N6P-IR-ECC99-E182CC-Matched-Pair-High-DurableDoubleTriode-Gold-Grid-NEW-OTK/171310973012?ssPageName=STRK:MEBIDX:IT&_trksid=p2055119.m1438.l2649



QUOTE="Tony51, post: 13648385, member: 425917"]I have just replaced the chinese junk drivers on my LD mk2 for the Jan5654w Drivers, what a great difference in sound. However i am a little confuse on the power tube, which do you recommend?[/QUOTE]
These power tubes were very popular http://www.ebay.com/itm/6N6P-IR-ECC...e=STRK:MEBIDX:IT&_trksid=p2055119.m1438.l2649                                                                                                                      Also power tube reviews page 201 post 3007 of thid thread


----------



## scottsays

Recently purchased a Little Dot MKIII through Massdrop and have been experimenting with various tubes--from suggestions from this thread. A big thank you for all the contributors--I have no clue about this stuff and am happy to get any advice.
I have a set of Fostex TH 900 with the Silver Dragon cord from Moon Audio--hoping to tamp down the excessive high end.
Really want to know if there is a good tube to match to these headphones that will tame the high end--
I really love the bass and sound of these headphones but---damn, the high end can get really piercing and frankly unlistenable with certain tracks.
If anyone has any knowledge and experience with this I would be grateful for any advice--
thanks!


----------



## i luvmusic 2

Try to use EQ instead of tube rolling,Tube rolling can get expensive(at least for me).


----------



## scottsays

i luvmusic 2 said:


> Try to use EQ instead of tube rolling,Tube rolling can get expensive(at least for me).


Good advice--
I use EQ when I am playing tracks on my AK 120 II--plugged into the Little Dot.
I recently bought a stand alone Tascam cd player and have it plugged in directly to the Little Dot.
I just ordered a Behringer FBQ1502HD EQ--that should do the trick.


----------



## robboffard

_(Mods, if this is in the wrong place, please let me know)_

LDMKIV tube rolling question from a newbie.

Bought my first tube to roll with: a pair of Mesa Boogie EL84/6BQ5s, recommended by a local dealer. They aren't working right: there's hardly any sound, just horrible static.

They are seated correctly, and I have de-oxidised the pins. They do not appear to be damaged or dead (silver top, no purple glow etc), and I bought them from a reputable dealer. Stock tubes working fine, with good sound, so it's not the amp itself. Before I send them back: it occurs to me that I may need to change the jumper switches. But I don't know what these look like, and Google is no help. Neither unfortunately is the LD manual/reference guide.

Do I need to change the jumper switches? If so, where are they? And please don't say 'next to the capacitors' - assume I'm an idiot please! Muchas gracias


----------



## gibosi

The 6BQ5 will not work in the LD4. See below for compatible tubes.

http://littledot.net/forum/viewtopic.php?f=9&t=820&sid=0e615810f969d644902c79770bea6e8d


----------



## robboffard

gibosi said:


> The 6BQ5 will not work in the LD4. See below for compatible tubes.
> 
> http://littledot.net/forum/viewtopic.php?f=9&t=820&sid=0e615810f969d644902c79770bea6e8d



Ugh. So much for good recommendations! Thanks mate.


----------



## Bryce.E

The brightness of these stock 6J1's in conjunction with my new pair of grado sr325e's makes my ears bleed. I can't wait for my Voshkod 6ZH1P-EV to get here.


----------



## dobigstuff

scottsays said:


> Recently purchased a Little Dot MKIII through Massdrop and have been experimenting with various tubes--from suggestions from this thread. A big thank you for all the contributors--I have no clue about this stuff and am happy to get any advice.
> I have a set of Fostex TH 900 with the Silver Dragon cord from Moon Audio--hoping to tamp down the excessive high end.
> Really want to know if there is a good tube to match to these headphones that will tame the high end--
> I really love the bass and sound of these headphones but---damn, the high end can get really piercing and frankly unlistenable with certain tracks.
> ...


Scottsays:

See below on what I finally settled on:





Happy Rolling


----------



## MIKELAP

Bryce.E said:


> The brightness of these stock 6J1's in conjunction with my new pair of grado sr325e's makes my ears bleed. I can't wait for my Voshkod 6ZH1P-EV to get here.


Dont think there gonna help your ear bleed


----------



## Tony51 (Sep 1, 2017)

Bryce.E said:


> The brightness of these stock 6J1's in conjunction with my new pair of grado sr325e's makes my ears bleed. I can't wait for my Voshkod 6ZH1P-EV to get here.



I found the Voshkod 6ZH1P-EV  to be on the bright side on my LD mk2 and less bass than my jan5654w drivers. So far the Jan5654w and the blue glass by siemen are my best tubes. You may want to try the Mullard RTC 5654RT
Tony


----------



## mordy

Bryce.E said:


> The brightness of these stock 6J1's in conjunction with my new pair of grado sr325e's makes my ears bleed. I can't wait for my Voshkod 6ZH1P-EV to get here.


Hi Bryce.E,

The Voskhod tubes are bright sounding - don't think that they will help. In addition, they need a very long time to burn in - around 120 hours (compared to 20-50 hours for most tubes).

In my LD MKIII days we rolled tons of tubes, and one of the best driver tubes was the Yugoslavian Ei 6HM5. It is not very expensive at all, and is a good recommendation.

http://www.ebay.com/itm/EI-6HM5-EC9...051561&hash=item5d4fdb1092:g:prcAAOSwDk5UEhHk

Be aware that they have a quick heat-up feature that looks like a fiery flash when you turn on the tubes - nothing to be concerned about.


----------



## Whelkie D

mordy said:


> Hi Bryce.E,
> 
> The Voskhod tubes are bright sounding - don't think that they will help. In addition, they need a very long time to burn in - around 120 hours (compared to 20-50 hours for most tubes).
> 
> ...


Yep.I'd second that about the Yugoslavian 6HM5s - really nice, detailed & rounded sound ( almost like a mix between the best bits of the Mullards and the Voskhods).


----------



## shepperd

I've been meaning to add to the discussion for some time but haven't gotten to the end of my tube rolling or reached any definitive opinion. First a big thanks to Mordy who started me off with his original post and second a disclaimer; I dont use head phones but I do have a very good system and because I bought a tube buffer/pre with those awful chinese tubes, I found this discussion and it set me off on a long NOS journey. Not counting the dead tubes and a few I haven't tried, I've been thru about 14 variants of the ef95 family, including some that have never been mentioned as far as I know.. I have been pleasantly surprised by the efficient honest and reactive service provided by 99% of the ebay sellers, especially Russian and Ukrainian. A few even sent me extra tubes or ones I didn't ask for!
The reason I'm jumping in is because I have 4 different variants of the Voskhod and while they do take time to break in, none have been bright. The first pair were marked 83, the second were the gold pin variety followed by a very early set (73') which do not have the ribbed glass, finally a set dated 88' To my surprise the last sound the best and have blossomed at around the 50 hour mark. 
Granted head phones offer a different sound than speakers and what I hear is no doubt different than what others do. Each tube has a slightly different perspective/sound and it is hard to grade them with any degree of certainty (which hasn't stopped me from trying!) Some tubes just are not as musical and satisfying as others and this is not just audiophilia nitpicking. But I have to say, having spent many hours breaking in each and every set and listening carefully, I always return to the Voskhod as being the best all round tube, especially the 88' variant. I had high hopes for the older variety but they are a bit too polite. Anyway none of this will help anyone who has different ears and equipment. Just my tale and it has been fun (and rather expensive) ordering NOS tubes from far off lands, waiting for days by the mail box, unpacking, inserting, listening...serious fun.


----------



## mordy

shepperd said:


> I've been meaning to add to the discussion for some time but haven't gotten to the end of my tube rolling or reached any definitive opinion. First a big thanks to Mordy who started me off with his original post and second a disclaimer; I dont use head phones but I do have a very good system and because I bought a tube buffer/pre with those awful chinese tubes, I found this discussion and it set me off on a long NOS journey. Not counting the dead tubes and a few I haven't tried, I've been thru about 14 variants of the ef95 family, including some that have never been mentioned as far as I know.. I have been pleasantly surprised by the efficient honest and reactive service provided by 99% of the ebay sellers, especially Russian and Ukrainian. A few even sent me extra tubes or ones I didn't ask for!
> The reason I'm jumping in is because I have 4 different variants of the Voskhod and while they do take time to break in, none have been bright. The first pair were marked 83, the second were the gold pin variety followed by a very early set (73') which do not have the ribbed glass, finally a set dated 88' To my surprise the last sound the best and have blossomed at around the 50 hour mark.
> Granted head phones offer a different sound than speakers and what I hear is no doubt different than what others do. Each tube has a slightly different perspective/sound and it is hard to grade them with any degree of certainty (which hasn't stopped me from trying!) Some tubes just are not as musical and satisfying as others and this is not just audiophilia nitpicking. But I have to say, having spent many hours breaking in each and every set and listening carefully, I always return to the Voskhod as being the best all round tube, especially the 88' variant. I had high hopes for the older variety but they are a bit too polite. Anyway none of this will help anyone who has different ears and equipment. Just my tale and it has been fun (and rather expensive) ordering NOS tubes from far off lands, waiting for days by the mail box, unpacking, inserting, listening...serious fun.


Hi shepperd,

Thanks for your thoughtful post. As you say, everybody has different gear and different tastes, and the main thing is to find what you like. Even though there seemed to be some consensus that the Voskhods were on the bright side, it does not mean that they will sound like that to everybody and in every system. 
As regards Russian tubes, and tubes in general, it seems that the older tubes were made to higher quality standards than later ones, but there are always exceptions.
The main thing is to derive enjoyment from your system. For me part of the tube mystique is to search for tubes (especially bargains) and to roll different ones.
The Little Dot MKIII came with 6N6P type power tubes. A simple and inexpensive plug in upgrade is the 6SN7(or variants)  with an adapter.


----------



## shepperd

My tube buffer/pre has only the two driver tubes, so no power tubes to play with. Regarding old vs new (er), my oldest ones were some 44' Tungsols that neither sounded special nor lasted long. One just went dead. I have had a few nos tubes just die...after searching for weeks I got a set of Tesla (the ones with the white tip) They lasted all of a week. I totally get why older tubes should sound better but unless I'm going deaf, the youngest of the bunch, these 88' Voskhods are my favorites. For the adventurous among you, there are some interesting tubes that may have escaped your attention; namely Melz, svetlana, fryazino, anod, novosibirsk, refrector. I am partial to the anod. There may be yet more discover. I have not tried Mullard or Telefunken.


----------



## Tony51 (Sep 4, 2017)

shepperd said:


> I've been meaning to add to the discussion for some time but haven't gotten to the end of my tube rolling or reached any definitive opinion. First a big thanks to Mordy who started me off with his original post and second a disclaimer; I dont use head phones but I do have a very good system and because I bought a tube buffer/pre with those awful chinese tubes, I found this discussion and it set me off on a long NOS journey. Not counting the dead tubes and a few I haven't tried, I've been thru about 14 variants of the ef95 family, including some that have never been mentioned as far as I know.. I have been pleasantly surprised by the efficient honest and reactive service provided by 99% of the ebay sellers, especially Russian and Ukrainian. A few even sent me extra tubes or ones I didn't ask for!
> The reason I'm jumping in is because I have 4 different variants of the Voskhod and while they do take time to break in, none have been bright. The first pair were marked 83, the second were the gold pin variety followed by a very early set (73') which do not have the ribbed glass, finally a set dated 88' To my surprise the last sound the best and have blossomed at around the 50 hour mark.
> Granted head phones offer a different sound than speakers and what I hear is no doubt different than what others do. Each tube has a slightly different perspective/sound and it is hard to grade them with any degree of certainty (which hasn't stopped me from trying!) Some tubes just are not as musical and satisfying as others and this is not just audiophilia nitpicking. But I have to say, having spent many hours breaking in each and every set and listening carefully, I always return to the Voskhod as being the best all round tube, especially the 88' variant. I had high hopes for the older variety but they are a bit too polite. Anyway none of this will help anyone who has different ears and equipment. Just my tale and it has been fun (and rather expensive) ordering NOS tubes from far off lands, waiting for days by the mail box, unpacking, inserting, listening...serious fun.



Perhaps, I need to burn my Voshkod EV some more. I know they are not at the 50 hour mark. Mine are ribbed and while at the moment are on the brighter side, they are indeed very good sounding in fact pretty darn clear. The ebayer I purchased from sells 4 at a time for a whopping 4.51plus 3 something for shipping. Can you tell me exactly the eBayer you purchased the 1988 from? I am also tube rolling and having fun with it. Thanks
Tony


----------



## shepperd

I will get back with the link. This is the seller who send this pair unasked and had previously sold me the older, non-ribbed variety. I want to stress that this could be a fluke. By rights 1988 must have been at the very end of production. I have never seen any later ones. Likewise, one can assume that the people making these must have been packing their bags and not very motivated! By then the whole system was falling apart, the most skilled workers looking for other jobs, the machines aging...
I dont have a paypal account so I have a neighbor order for me and he has no doubt erased his browser history and paypal orders because hew is fed up with my obsession! I do have a mailing address though. Anyway they are cheap so in the worse case you can say my ears are unreliable. What I did notice was that the boxes were original and obviously never opened. The pins on the tubes were shiny and the lettering perfect, showing exact date, the rocket logo and batch number which were identical, none of which I have seen before. Some tubes I have bought had no indication of what they were anymore so I just took it on faith!


----------



## Tony51

kamzak88 said:


> so why such a different
> 
> "*2.3 Mullard CV131/6CQ6*
> 
> ...




Where can one purchase these Mullard? i cant find them with these exact numbers *Mullard M8161/CV401?*


----------



## Tony51

shepperd said:


> I will get back with the link. This is the seller who send this pair unasked and had previously sold me the older, non-ribbed variety. I want to stress that this could be a fluke. By rights 1988 must have been at the very end of production. I have never seen any later ones. Likewise, one can assume that the people making these must have been packing their bags and not very motivated! By then the whole system was falling apart, the most skilled workers looking for other jobs, the machines aging...
> I dont have a paypal account so I have a neighbor order for me and he has no doubt erased his browser history and paypal orders because hew is fed up with my obsession! I do have a mailing address though. Anyway they are cheap so in the worse case you can say my ears are unreliable. What I did notice was that the boxes were original and obviously never opened. The pins on the tubes were shiny and the lettering perfect, showing exact date, the rocket logo and batch number which were identical, none of which I have seen before. Some tubes I have bought had no indication of what they were anymore so I just took it on faith!




Ok, thanks, i am standing by for the link.


----------



## gibosi

Tony51 said:


> Where can one purchase these Mullard? i cant find them with these exact numbers *Mullard M8161/CV401?*



It should be CV4015. However, the Common Valve number, CV4015, is not at all important. It is simply an old British military inventory number for this kind of tube. And in fact, the British military considers the CV4015 and CV131 to be identical. CV4015 is the older number and CV13 is the newer.

The number that matters is M8161 (or 6065). This tube number indicates that it was considered to be somewhat better than the consumer grade EF92. Here, "better" typically means a longer lifetime, more resistance to shock and vibration and so forth. That is, it was designed to be used in more severe environments, such as a military setting or on a factor floor. And this does not mean it will sound better. After all,  these pentodes were never designed for use in audio circuits.

IMO, when comparing tubes as above, it is most important to know in which factory and in what year the tubes were manufactured. Without these facts, the above comparison is relatively meaningless. Again, in my opinion.


----------



## carlosgab

Recently I bought a matched pair of yugoslavian 6hm5 driver tubes which Im still waiting to arrive. I would like to know if siemens 6hm5 has any difference or improvement than a telefunken 6hm5? Considering that it is a few dollars more expensive.


----------



## gibosi

I felt that the Yugoslavian, Mullard and GE 6HM5 were vastly superior to the Siemens. Based on that, I have always recommended "tall" bottle 6HM5s over the "short" bottles. Since the Telefunkens I have seen look like relabeled Siemens short bottles I never tried them...

Although labeled RCA, these were manufactured by Siemens.


----------



## scottsays

I also really like the 6HM5 tubes---purchased on the recommendations on this thread.
Was reading this thread yesterday and switched out the Voshkod 6ZHIP-
was pleasantly surprised with the superior sound quality. I have had both for about 3 weeks--just experimenting with them.
I am new to all this--really enjoying all the suggestions and advice.
Is there any benefit to upgrading the LD MKIII to another LD model?
Or is the real upgrades in the tubes?


----------



## mordy

scottsays said:


> I also really like the 6HM5 tubes---purchased on the recommendations on this thread.
> Was reading this thread yesterday and switched out the Voshkod 6ZHIP-
> was pleasantly surprised with the superior sound quality. I have had both for about 3 weeks--just experimenting with them.
> I am new to all this--really enjoying all the suggestions and advice.
> ...


Hi Scottsays,

Upgrading is a slippery slope (hill?) You can definitively get much improved sound with better tubes, but there is a limit. Some members of the LD thread upgraded to the Polish made Elise amp which is a big step up, but also much more money in comparison to the LD MKIII. There is an LD MKIV, but I think that the difference is not major in sound.

It all depends on what makes you happy and how much you are willing to spend. There is always better, but above a certain level the increase in performance is more incremental and at significant cost.

After owning the LD MKIII for a couple of years and rolling many dozens of tubes, I bought the Elise, and the MKIII has been gathering dust since.
I also own an upgrade of the Elise called Euforia. It is better, but not a quantum leap.

I think that Gibosi upgraded to a Glenn amp which I think he still owns and he would be able to describe the difference compared to the Little Dot.

The other side of the coin is that there are now available solid state amps that may be as satisfying as tube amps, but that is another story.....


----------



## gibosi

mordy said:


> Hi Scottsays,
> 
> Upgrading is a slippery slope (hill?) You can definitively get much improved sound with better tubes, but there is a limit. Some members of the LD thread upgraded to the Polish made Elise amp which is a big step up, but also much more money in comparison to the LD MKIII. There is an LD MKIV, but I think that the difference is not major in sound......
> 
> ...



Like the Elise, the Glenn is a quantum leap over any of the LD I, II, III and IV series of amps. But again, like the Elise, the Glenn is considerably more expensive. In general, I would venture to say that any OTL running 6AS7 output tubes and a quality double triode, such as a 6SN7 or 6DJ8, will be a quantum leap over any of the LDs. But not only are these amps more expensive, the tubes are also more expensive. So for sure, upgrading is a very slippery slopt/hill/mountain. lol 

That said, for the money the LDs are very tough to beat in terms of build quality and sonics. And as long as the LD continues to please, your wallet will be happy as well.


----------



## dobigstuff

As Mordy stated in another Post, the fun is searching and trying many different types of tubes as well as finding out what other tube compliments are out there that will work.  

One suggestion for the Little Dot MK III:




NOS Tung-Sol 6NS7 Power Tubes (w/ Adapters) and C3G Driver Tubes (w/ Adapters).  

This combo raises the performance of the Little Dot MK III and is one of the best combos out there.  Again it depends on your source, type of music, Headphones, etc.  I use this with the HD 700's.  Note:  I recently picked up a Darkvoice 336 SE and with the HD 700's, for me, it is even better than the Little Dot MK III.


----------



## scottsays

Thanks guys--really appreciate the input. As you know this is a really fun but expensive hobby---as we progress up the food chain--we hear things better and going back is unacceptable--but at some point you have to say--Enough! I'm searching for the Holy Grail and just have to be happy with what I have. It's good to upgrade, but eventually it just gets to the point where the money spent versus the slight upgrade is not worth it.
I am gonna enjoy and experiment more with the LD MKIII--I just got the damn thing and am already want better! Argh---gonna enjoy what I have now---
maybe upgrade in a year or so (?)--
APPRECIATE all the advice and input--THANKS!


----------



## OctavianH

When I bought the MK2, the strategy was to go with the cheaper one (MK2 vs MK3) and spend more on the tube replacements, because I was at the beginning in this area and I was realizing that I will need several tries to reach what I expect soundwise.  And I was right about this. But now, when I already start to think about an upgrade, I guess I have to decide if next time I will follow the same strategy. 
So I would be curious to know you opinion regarding the best choice between Elise, Elise upgraded (PSVane) and Euforia?

Prices currently are:

Euforia = 1399 USD
Elise upgraded with PSVane = 999 USD
Elise stock Tung Sol = 849 USD

I will make this upgrade sometime in the future, I have no idea when. At the moment I am just curious to see which of these 3 versions is the preferred option amongst others.
I think that the Elise + PSVane is very close to Euforia, at a difference of 400USD. But this is just an assumption.


----------



## gibosi

Most folks with considerable experience with the 6SN7 do not believe that the PSVane competes all that well with many of the NOS tubes available on eBay and elsewhere. It is important to keep in mind, that from a manufacturer's standpoint, a reliable and plentiful supply of new tubes, for inclusion in shipped amps and for spare parts, is paramount. And therefore, Feliks and most other manufacturers ship their units with current production tubes from Russia and China. They typically do not ship their amps with 50 year old tubes, even if they might sound better...

Therefore, IMO, it is necessary to consider these two amps, Euphoria and Elise, without tubes. After all, you can put the same tubes in either one. So it comes down to a decision regarding the purported differences in materials and build quality. As I have no experience with either, I cannot say if the Euphoria is worth $400 more (equipped with the same tubes.)


----------



## mordy (Sep 6, 2017)

gibosi said:


> Most folks with considerable experience with the 6SN7 do not believe that the PSVane competes all that well with many of the NOS tubes available on eBay and elsewhere. It is important to keep in mind, that from a manufacturer's standpoint, a reliable and plentiful supply of new tubes, for inclusion in shipped amps and for spare parts, is paramount. And therefore, Feliks and most other manufacturers ship their units with current production tubes from Russia and China. They typically do not ship their amps with 50 year old tubes, even if they might sound better...
> 
> Therefore, IMO, it is necessary to consider these two amps, Euphoria and Elise, without tubes. After all, you can put the same tubes in either one. So it comes down to a decision regarding the purported differences in materials and build quality. As I have no experience with either, I cannot say if the Euphoria is worth $400 more (equipped with the same tubes.)


Hi OctavianH and Gibosi,

As an owner of both the Elise and the Euforia I can speak from experience; however, the present Elise has been upgraded and from what I read sounds even closer to the Euforia.
I own the original Elise. In comparison, the sound is similar, with the Euforia having a more fleshed out sound and the Elise sounding leaner. Some people who have heard both even prefer the Elise over the Euforia. Personally, I think that the Euforia sounds a little better, but I am not sure if it merits the price difference. The build quality is the same, but the Euforia uses premium parts. It also seems that the Euforia brings out the best in any tubes used and that it is not as sensitive as the Elise to tube choices. (Could be that the upgraded Elise has this quality as well - don't know).
Gibosi is 100% on target with his comment about availability of tubes. A manufacturer has to be able to have a reliable and plentiful supply of tubes and cannot rely on the availability or rare or old tubes, even if they sound better.

The Psvane tubes (6SN7-CV181 UK version) can be bought from China for $89/pair on eBay so if you decide to go with the Elise you could get the standard tubes and save some money by buying them separately. (My guess is that shipping and customs to Poland explains the price difference.) However, most people who have them have substituted other tubes (many of which are much cheaper) with very good results. Just take a look at the Euforia threads for tube suggestions.
I found a true bargain tube complement that sounds very good - Russian Foton 6H8C tubes paired with RCA 6AS7G. If you shop carefully, these can be had for less than $35 including shipping.
The other end of the price spectrum are GEC 6080/6AS7 power tubes and Sylvania 6SN7W/Tung Sol 6SN7 RBP driver tubes which could cost as much as the amp or more.....

The main point is that these two Feliks amps can give you tremendous musical pleasure. They are also very flexible in terms of tube rolling with many choices available.


----------



## OctavianH

Thanks a lot Mordy and gibosi for all your advices. It seems that the upgrade implies a new quest for "the perfect tube". So I will delay it as much as possible since these days I am quite tired of searching and I am also quite pleased about my MK2.
Regarding 6H8C, I have 6 tubes like these:








These are the ones you mention?

They were quite a disappointment when I tried in MK2 via adapters, but if these are the ones you describe, I will definitely try sometime in the future on my future Elise/Euforia amp.


----------



## mordy

OctavianH said:


> Thanks a lot Mordy and gibosi for all your advices. It seems that the upgrade implies a new quest for "the perfect tube". So I will delay it as much as possible since these days I am quite tired of searching and I am also quite pleased about my MK2.
> Regarding 6H8C, I have 6 tubes like these:
> 
> 
> ...


Hi OH,

What I have looks similar but made in the 60's. I am waiting for a pair from 1952-3 which are supposed to be better sounding, but they have been "lost" in the US Customs for three weeks - don't know when they will show up.

In the past I read that the Fotons weren't good sounding tubes. It could very well be that they are not a good match in the Little Dot amps. However, in my Elise/Euforia amps they shine when paired with RCA 6AS7G and GEC 6080 power tubes. It is a question of synergy and amps - not everything works in every environment.

The 6SN7 is supposed to draw 0.6A and even though the 6H8C is said to be an equivalent, they draw 0.9A - maybe it has something to do with how they sound in the LD amps....


----------



## Oskari

OctavianH said:


>


Same type, different factory. This is from NEVZ-Soyuz in Novosibirsk.


----------



## OctavianH

OK, and about the sound quality? I have to admit I obtained them very cheap from a guy who tried them in a handmade amp and changed the design later.


----------



## Oskari

I'll let others answer that.


----------



## gibosi

mordy said:


> The 6SN7 is supposed to draw 0.6A and even though the 6H8C is said to be an equivalent, they draw 0.9A - maybe it has something to do with how they sound in the LD amps....



According to this datasheet, the 6H8C draws 0.6A, the same as the 6SN7:

http://www.mif.pg.gda.pl/homepages/frank/sheets/113/6/6N8S.pdf


----------



## mordy

gibosi said:


> According to this datasheet, the 6H8C draws 0.6A, the same as the 6SN7:
> 
> http://www.mif.pg.gda.pl/homepages/frank/sheets/113/6/6N8S.pdf


Thanks Gibosi, I may have mixed it up with a different 6SN7 variant - maybe the CV181


----------



## i luvmusic 2

OMG those mentioned AMPS are expensive.


----------



## gibosi

mordy said:


> Thanks Gibosi, I may have mixed it up with a different 6SN7 variant - maybe the CV181



Yep, the "real" CV181, the one that was manufactured by Mullard, draws 0.9A.


----------



## Tony51

gibosi said:


> It should be CV4015. However, the Common Valve number, CV4015, is not at all important. It is simply an old British military inventory number for this kind of tube. And in fact, the British military considers the CV4015 and CV131 to be identical. CV4015 is the older number and CV13 is the newer.
> 
> The number that matters is M8161 (or 6065). This tube number indicates that it was considered to be somewhat better than the consumer grade EF92. Here, "better" typically means a longer lifetime, more resistance to shock and vibration and so forth. That is, it was designed to be used in more severe environments, such as a military setting or on a factor floor. And this does not mean it will sound better. After all,  these pentodes were never designed for use in audio circuits.
> 
> IMO, when comparing tubes as above, it is most important to know in which factory and in what year the tubes were manufactured. Without these facts, the above comparison is relatively meaningless. Again, in my opinion.




Thank you buddy! I found them and are on order. I will soon find out if these will top my Jan5654W which are a great match to my Senn HD600.


----------



## DylanF

mordy said:


> Hi Bryce.E,
> 
> The Voskhod tubes are bright sounding - don't think that they will help. In addition, they need a very long time to burn in - around 120 hours (compared to 20-50 hours for most tubes).
> 
> ...



Please don't cringe, but I just ordered these and I have the LD MKII not the III, is that OK?


----------



## Whelkie D

DylanF said:


> Please don't cringe, but I just ordered these and I have the LD MKII not the III, is that OK?


What have you just ordered, the Voskhods or the Yugo 6HM5s? Both are good in the MKII although I think I prefer the 6HM5s (just).


----------



## DylanF

Whelkie D said:


> What have you just ordered, the Voskhods or the Yugo 6HM5s? Both are good in the MKII although I think I prefer the 6HM5s (just).



The Yugo 6HM5 matched pair.  Thanks for helping, I'll give them a good run on my headset/LDMKII daily on my PC.


----------



## jon parker

I hope this a cool place to ask this buttt...  (I'll post some tube reviews later!)

Ive just got a LD 1+ It came with the wonderful Mullard 8100's
To start I plugged in my 300ohm Senn, HD 540 and it sounded phenomenal - Even my 600ohm AKG 240 Sextetts sounded amazing
BUT 
When I plugged in 300ohm Senn. 560 Ovations there was a buzzing like it was clipping or > the sound a battery powered amp makes as its running out of battery <
Ive been tube rolling using just the AKG's
I just plugged in the Senn. 540's again and now they too are having the same sound issues as the 560 Ovation ??

Does anyone have a clue what is happening here?  
Thanks


----------



## mordy

gibosi said:


> Yep, the "real" CV181, the one that was manufactured by Mullard, draws 0.9A.





jon parker said:


> I hope this a cool place to ask this buttt...  (I'll post some tube reviews later!)
> 
> Ive just got a LD 1+ It came with the wonderful Mullard 8100's
> To start I plugged in my 300ohm Senn, HD 540 and it sounded phenomenal - Even my 600ohm AKG 240 Sextetts sounded amazing
> ...


Hi JP,

I am not familiar with the LD 1+, but my suggestion is to carefully check all connections that they are good and tight. Also to take out the tubes and clean the pins. The best method IMHO is to gently scrape them with a thin knife blade (does not have to be sharp) or similar, making sure that the pins are clean and shiny.
Sometimes hum and buzz come from a portable phone or electronic device nearby - you need to check for this too.
Good luck!


----------



## rexhu100

Just getting started on the rube rolling game on my LD MKIII. Very excited!


----------



## jon parker

mordy said:


> Hi JP,
> 
> I am not familiar with the LD 1+, but my suggestion is to carefully check all connections that they are good and tight. Also to take out the tubes and clean the pins. The best method IMHO is to gently scrape them with a thin knife blade (does not have to be sharp) or similar, making sure that the pins are clean and shiny.
> Sometimes hum and buzz come from a portable phone or electronic device nearby - you need to check for this too.
> Good luck!



SOLVED:
Thanks Buddy - Quite by accident I solved it on a flash of inspiration / logical thinking!
Thought I would post the solution here as it is a very strange and misleading problem

I realized that my headphones with 1/4" jacks had no issues - Basically with small jacks with adapters, when they buzz, if I slowly turn the adapter round I reach a 'sweet' point where everything is there as it should be 
Very deceptive because the issue has ALL the hallmark, actual sounds that come from faulty tubes !!

Anyhoo, in keeping with this thread, currently tube rolling BUT the Mullards are by far the 'best' although the other 3 types i've tried thus far all
have unique qualities that with certain headphones add something wonderful


----------



## mordy

jon parker said:


> SOLVED:
> Thanks Buddy - Quite by accident I solved it on a flash of inspiration / logical thinking!
> Thought I would post the solution here as it is a very strange and misleading problem
> 
> ...


Hi JP. 
Glad that you found the problem - can be very challenging at times......


----------



## rexhu100

Just gotten my RCA 5654 today, and swapped with the GE JAN-5654W that I have been using. WOW! I did not expect to hear such a big difference in sound. The bass is immediately extended. I heard many people say that RCA tubes are more 'bassy', and I has always been very skeptical, but it was no hype/myth at all! GE JAN-5654W in comparison has better clarity in the mid and high, but man these RCA tubes are awesome. 

I'm just getting started in the rube rolling game. This is fun!


----------



## Tony51

rexhu100 said:


> Just gotten my RCA 5654 today, and swapped with the GE JAN-5654W that I have been using. WOW! I did not expect to hear such a big difference in sound. The bass is immediately extended. I heard many people say that RCA tubes are more 'bassy', and I has always been very skeptical, but it was no hype/myth at all! GE JAN-5654W in comparison has better clarity in the mid and high, but man these RCA tubes are awesome.
> 
> I'm just getting started in the rube rolling game. This is fun!




You might change your mind again if you give the Mullard 8161/4015 from 1969 a try. I use them with the LD mk2 and the Super Power Tubes 6H30P-i (Sovtek) (cryoset certified) plus it yielded more overall power output. I bit more than the Russian Gold Grid which is just as good, way cheaper but supplies a tad less power output. I also connected a Nobsound bass/treble PreAmp selling for 45.00 on amazon and that gave me even more power output combines. A match made in heaven. The HD600 sound fantastic and so those my Grados RS2e. I mostly keep the treble/bass flat at 12 oclock but if i need a tad of either for those mediocre recordings, it responds well. Usually no more than 2 o'clock is needed. Happy tube rolling!


----------



## dobigstuff

I have the HD 700's.  The GE 5654 Drivers are great.  I also had the Telefunken 5654 Drivers which were even better.  But one of the best Drivers for the Little Dots are the C3G.


----------



## rexhu100

dobigstuff said:


> I have the HD 700's.  The GE 5654 Drivers are great.  I also had the Telefunken 5654 Drivers which were even better.  But one of the best Drivers for the Little Dots are the C3G.



Looks good! Where did you get those adapters on the driver tube sockets?


----------



## Tony51

dobigstuff said:


> I have the HD 700's.  The GE 5654 Drivers are great.  I also had the Telefunken 5654 Drivers which were even better.  But one of the best Drivers for the Little Dots are the C3G.


Ah? better picture please, that looks gorgeous worthy of a nicer picture for us to drool. Thank you.


----------



## gibosi

Tony51 said:


> Ah? better picture please, that looks gorgeous worthy of a nicer picture for us to drool. Thank you.



Some info I put together a few years ago on using a pair of C3g as drivers:

https://www.head-fi.org/threads/lit...e-rolling-guide.563884/page-401#post-10512665


----------



## Tony51

Well, that was interesting info. I have the LD mk2......hmmm thinking.


----------



## dobigstuff

Tony51 said:


> Ah? better picture please, that looks gorgeous worthy of a nicer picture for us to drool. Thank you.


Tony51:

I hope these are better:


----------



## dobigstuff

rexhu100 said:


> Looks good! Where did you get those adapters on the driver tube sockets?


rexhu100:

This is the link for the C3G Adapters:

http://www.ebay.com/itm/201330219735?_trksid=p2057872.m2749.l2649&ssPageName=STRK:MEBIDX:IT


----------



## rexhu100

dobigstuff said:


> rexhu100:
> 
> This is the link for the C3G Adapters:
> 
> http://www.ebay.com/itm/201330219735?_trksid=p2057872.m2749.l2649&ssPageName=STRK:MEBIDX:IT



Thanks!


----------



## Tony51

dobigstuff said:


> Tony51:
> 
> I hope these are better:


Wow, niceeee


----------



## rexhu100

Almost ruin my LD3 just now... I bought a pair of 6SN7 tubes that I wanted to try, but I got the wrong adapter 6SN7 -> 12AX7. The transformer got really hot as if I have had it on for like an hour, but fortunately I turned it off quickly. I switched back to the stock tubes after the unit cools down and tested it. I think the amp survived stupidity this time... 

Anyway, I just wanted to post this experience here so folks will now steer clear of the wrong type of adapter.


----------



## Scutey

rexhu100 said:


> Just getting started on the rube rolling game on my LD MKIII. Very excited!


rexhu100,

Just thought I'd add my little bit. As dobigstuff has said you can't get better than the c3g for drivers, that and old stock 6sn7's is really about as good as you can get for the LD MKIII. I've been tube rolling the LD for more than a year and my personal endgame with the LD is c3g and Jan CKR Ken Rad's, they are a bit on the cool side but wonderfully airy, clear, detailed and tight deep bass, although they are expensive, another cheaper alternative in the Electro Harmonix, which although not as refined as old stock stuff is still very good. 

The c3g's in the pic are Telefunken..


----------



## Scutey

For some reason the pic won't load!.


----------



## mordy

rexhu100 said:


> Almost ruin my LD3 just now... I bought a pair of 6SN7 tubes that I wanted to try, but I got the wrong adapter 6SN7 -> 12AX7. The transformer got really hot as if I have had it on for like an hour, but fortunately I turned it off quickly. I switched back to the stock tubes after the unit cools down and tested it. I think the amp survived stupidity this time...
> 
> Anyway, I just wanted to post this experience here so folks will now steer clear of the wrong type of adapter.


You are lucky - I unknowingly used a defective adapter and fried one channel in my LD MKIII.
Does anybody have a suggestion where to have it fixed at a reasonable cost?
The shipping to China two ways will cost me $130 which is too much.
All four tubes light up, but one channel is dead. I suspect that it just needs changing a resistor or two, but I don’t know.


----------



## Scutey

Finally managed to work it out, my end game set up for the LD MKIII.


----------



## MIKELAP

Scutey said:


> Finally managed to work it out, my end game set up for the LD MKIII.


That's why we always suggested for several years now to start reading the thread from the end


----------



## dobigstuff (Sep 29, 2017)

Scutey:
See above what I settled on:  NOS USA Tall Bottle Tung-Sol 6SN7 Power Tubes and Siemens C3G Driver Tubes


----------



## DylanF (Sep 29, 2017)

dobigstuff said:


> Scutey:
> See above what I settled on:  NOS USA Tall Bottle Tung-Sol 6*NS*7 Power Tubes and Siemens C3G Driver Tubes



Will this work for the LDMKII and do I need some tube adapters for the Tun-Sols?
Since I'm a noob at this stuff, can you confirm that Tung-Sol again... Are these a good example of them?  (is the *NS* or *SN* swapped in description for 6*NS*7?)
*Tung-Sol 6SN7GTB tubes tall glass black plates D-getter Balanced*
http://www.ebay.com/itm/2-USA-Tung-...775205?hash=item1c8c59bb65:g:mOQAAOSwgchZdOyT


----------



## Scutey (Sep 29, 2017)

Think I've read every page some more than once, absolutely invaluable, now I'm doing the same thing with the LD tube Rolling thread.


----------



## dobigstuff

DylanF said:


> Will this work for the LDMKII and do I need some tube adapters for the Tun-Sols?
> Since I'm a noob at this stuff, can you confirm that Tung-Sol again... Are these a good example of them?  (is the *NS* or *SN* swapped in description for 6*NS*7?)
> *Tung-Sol 6SN7GTB tubes tall glass black plates D-getter Balanced*
> http://www.ebay.com/itm/2-USA-Tung-...775205?hash=item1c8c59bb65:g:mOQAAOSwgchZdOyT


DylanF:

Those look legit.  I corrected my post.  They are 6SN7.  I inadvertantly switched the SN.  Sorry.


----------



## DylanF (Sep 29, 2017)

dobigstuff said:


> DylanF:
> 
> Those look legit.  I corrected my post.  They are 6SN7.  I inadvertantly switched the SN.  Sorry.


I appreciate the reply, thank you (bought them just now). One other thing, I know I need those c3g adapters on my LDMKII on the front tubes, what adapters do I need for the rear Tung-Sol's?  All your help is really appreciated, it saves myself and others a bunch of research time...

Something like this: http://www.ebay.com/itm/1pc-6SN7-6n...588465?hash=item2ed22be831:g:Yc4AAOSwv0tVJf1i

1pc 6SN7 6n8p CV181 TO 6N1 ECC85 6N6 6N11 tube adapter 6.3V (CNC Copper body)


----------



## MIKELAP

DylanF said:


> I appreciate the reply, thank you. One other thing, I know I need those c3g adapters on my LDMKII on the front tubes, what adapters do I need for the rear Tung-Sol's?  All your help is really appreciated, it saves myself and others a bunch of research time...


http://www.ebay.com/itm/1piece-gold...922595?hash=item2efdc32e23:g:VQAAAOSwyQtVoKwq


----------



## dobigstuff

MIKELAP:

As always you are quickly there with help.  Thanks for posting the adapters.


----------



## DylanF

dobigstuff said:


> MIKELAP:
> 
> As always you are quickly there with help.  Thanks for posting the adapters.



Are the ones I posted good to go as well?


----------



## MIKELAP

DylanF said:


> Are the ones I posted good to go as well?


Nope ,about the link i posted the adapter is expensive yes but is of good quality


----------



## Jacobal

Voshkods. Terrific sounding gear, wished build was better. Heck they put some amps 10x of worth to shame.


----------



## Modulateur-75

Yep, I still listen to 6ZH1P-EVs sometimes, still sound magnificent for the price.


----------



## Modulateur-75

gibosi said:


> I felt that the Yugoslavian, Mullard and GE 6HM5 were vastly superior to the Siemens. Based on that, I have always recommended "tall" bottle 6HM5s over the "short" bottles. Since the Telefunkens I have seen look like relabeled Siemens short bottles I never tried them...
> 
> Although labeled RCA, these were manufactured by Siemens.



Hi Gibosi,
About the 6HM5 : are the settings the same as ef95?
Thanks


----------



## MIKELAP

Modulateur-75 said:


> Hi Gibosi,
> About the 6HM5 : are the settings the same as ef95?
> Thanks


Yes


----------



## gibosi

Modulateur-75 said:


> Hi Gibosi,
> About the 6HM5 : are the settings the same as ef95?
> Thanks



Mikelap beat me to it!


----------



## Modulateur-75

Well thanks both of you 
I began to read this thread a few weeks ago. I am around page 100 lol. 
This thread is like an Explorer mission but not in space, rather in audiophily  I feel sorry I didn't join you earlier !
I am looking right now for Tung Sols 6AH6. Quite difficult to get... In comparison, do the Sylvania sound ok (years 60')?


----------



## OctavianH

Noob question: Guys, do you power off your Littledots after 3-4 hours to let the tubes loose heat? Because I usually listen 8h without any pause and I am not sure if this can damage somehow the amp.


----------



## jon parker

OctavianH said:


> Noob question: Guys, do you power off your Littledots after 3-4 hours to let the tubes loose heat? Because I usually listen 8h without any pause and I am not sure if this can damage somehow the amp.



In terms of Amp burn in they recommend to let the amp cool down every 24 hours so you should be fine for 8 hour sessions although they also say if you do use it for long sessions just to make sure they have plenty of air movement around the unit so perhaps best not have it on your duvet!


----------



## Whelkie D

jon parker said:


> In terms of Amp burn in they recommend to let the amp cool down every 24 hours so you should be fine for 8 hour sessions although they also say if you do use it for long sessions just to make sure they have plenty of air movement around the unit so perhaps best not have it on your duvet!


I made a cooling device using an old computer fan in a wooden box which blows air onto and around the amp via the copper tubes. this seems to keep it fairly cool even after several hours of use............


----------



## mdr944

Whelkie D said:


> I made a cooling device using an old computer fan in a wooden box which blows air onto and around the amp via the copper tubes. this seems to keep it fairly cool even after several hours of use............



That is a really elaborate piece of hardware you have made.  BRAVO!


----------



## jon parker

mdr944 said:


> That is a really elaborate piece of hardware you have made.  BRAVO!



GOOD LORD!! - Ahhhhh of course, its the English 'mushroom' season. A truly magical time


----------



## MIKELAP

Modulateur-75 said:


> Well thanks both of you
> I began to read this thread a few weeks ago. I am around page 100 lol.
> This thread is like an Explorer mission but not in space, rather in audiophily  I feel sorry I didn't join you earlier !
> I am looking right now for Tung Sols 6AH6. Quite difficult to get... In comparison, do the Sylvania sound ok (years 60')?


i have 3 tungsol 6ah6 +many others 6au6,6136 that are the same type and i also have a pair of new adapters for these tubes .No longer have the amp. If your interested in these tubes let me know .


----------



## Modulateur-75 (Oct 7, 2017)

MIKELAP said:


> i have 3 tungsol 6ah6 +many others 6au6,6136 that are the same type and i also have a pair of new adapters for these tubes .No longer have the amp. If your interested in these tubes let me know .


Hi Mikelap,
Thanks a lot. Yes I am interested. A lot!
TS 6ah6 are not the ones with "O" getter as I can see from the pics. I don't know if I am right but it has been said that the "right" ones are the "O" getter. 
The adapters won't fit in my amp (Zhilai D2). It is a good and cheap preamp. Between a Pro-ject Dac and a amp, I can clearly hear the difference with or without.
My amp is only ef95 and I can do strapping, no pb. Are the 6136 ok for the ef95 settings? They are some kind 6AU6 (mil specs?) aren't they?
I see you have Tektronix 6AU6  Do you sell some?


----------



## MIKELAP

Modulateur-75 said:


> Hi Mikelap,
> Thanks a lot. Yes I am interested. A lot!
> My amp is only ef95 and I can do strapping, no pb. Are the 6136 ok for the ef95 settings? Are the TS 6ah6 the ones with "O" getter?
> The adapters won't fit in my amp (Zhilai D2)


The millitary TUNG SOL U.S.A.F. 6AH6WA i have  are with square getters.You can  use the 6AH6 tube strappIng pin 2and 7 on EF95 setting .As for the 6136 they are a 6AU6 equivalent and are used on EF95 setting with pins 2 and 7 strapped .The Tektronix 6AU6 ,i have a pair that i could let go since i dont have the amp anymore .PM me if your interested. Thanks.


----------



## i luvmusic 2

Hi Guys,Anyone remember the page where it have the list of  all the compatible tubes and how to strap them.

Thanks!


----------



## gibosi

I think you mean page 77?

https://www.head-fi.org/threads/lit...ube-rolling-guide.563884/page-77#post-9392055


----------



## i luvmusic 2

gibosi said:


> I think you mean page 77?
> 
> https://www.head-fi.org/threads/lit...ube-rolling-guide.563884/page-77#post-9392055


Thank You!


----------



## i luvmusic 2

Ok so i made an adapter for the 6HM5 and 5654 to 6SN7,The 6HM5 sound darn good and for the 5654 it's ok this(5654) tube sound better on the LD MKIII.Another question how do i configure the EF91/EF92 to 6SN7?Thanks again!!


----------



## gibosi (Oct 8, 2017)

First it is necessary to convert an EF91/EF92 into a triode. To begin strap pins 5 and 6 together as you did for the 5654. Next, strap pin 7 to either pin 5 or 6 and you will have a triode-strapped pentode. That is, both the screen grid and the suppressor grid will be strapped to the plate. After that, it is a simple matter to connect the cathode, grid 1 and plate of the two EF91/EF92 to each section of the 6SN7, in the same way as you did with the 5654.

And I am not surprised that the EF95/5654 was just OK stuffed into a 6SN7 socket. These sharp-cutoff pentodes, EF91, EF92 and EF95 are not all that comfortable in a 6SN7 socket as they require very different bias values.

Have fun!


----------



## i luvmusic 2

gibosi said:


> First it is necessary to convert an EF91/EF92 into a triode. To begin strap pins 5 and 6 together as you did for the 5654. Next, strap pin 7 to either pin 5 or 6 and you will have a triode-strapped pentode. That is, both the screen grid and the suppressor grid will be strapped to the plate. After that, it is a simple matter to connect the cathode, grid 1 and plate of the two EF91/EF92 to each section of the 6SN7, in the same way as you did with the 5654.
> 
> And I am not surprised that the EF95/5654 was just OK stuffed into a 6SN7 socket. These sharp-cutoff pentodes, EF91, EF92 and EF95 are not all that comfortable in a 6SN7 socket as they require very different bias values.
> 
> Have fun!


 Thank You Very Much!


----------



## i luvmusic 2 (Oct 8, 2017)

gibosi said:


> First it is necessary to convert an EF91/EF92 into a triode. To begin strap pins 5 and 6 together as you did for the 5654. Next, strap pin 7 to either pin 5 or 6 and you will have a triode-strapped pentode. That is, both the screen grid and the suppressor grid will be strapped to the plate. After that, it is a simple matter to connect the cathode, grid 1 and plate of the two EF91/EF92 to each section of the 6SN7, in the same way as you did with the 5654.
> 
> And I am not surprised that the EF95/5654 was just OK stuffed into a 6SN7 socket. These sharp-cutoff pentodes, EF91, EF92 and EF95 are not all that comfortable in a 6SN7 socket as they require very different bias values.
> 
> Have fun!




Hi Gibosi,
 In my adapter(EF95 to 6SN7)Pins 6 and 7 are shorted so i just put a Switch between Pin 5 and 6 now i can use EF91 tubes.Thanks again G!

  Since i have a hard time selling all my 7 Pins tubes i use them for my DIY amp instead....


----------



## DylanF

rexhu100 said:


> Almost ruin my LD3 just now... I bought a pair of 6SN7 tubes that I wanted to try, but I got the wrong adapter 6SN7 -> 12AX7. The transformer got really hot as if I have had it on for like an hour, but fortunately I turned it off quickly. I switched back to the stock tubes after the unit cools down and tested it. I think the amp survived stupidity this time...
> 
> Anyway, I just wanted to post this experience here so folks will now steer clear of the wrong type of adapter.


And the right adapter is? 6SN7 to ?   Thanks ! Dylan


----------



## MIKELAP

DylanF said:


> And the right adapter is? 6SN7 to ?   Thanks ! Dylan


6sn7 to 6cg7 http://www.ebay.com/itm/1piece-gold...e=STRK:MEBIDX:IT&_trksid=p2055119.m1438.l2649


----------



## rexhu100

DylanF said:


> And the right adapter is? 6SN7 to ?   Thanks ! Dylan



Or ECC88 (not sure if they are equivalent to 6CG7), which is what I ended up buying.


----------



## gibosi

rexhu100 said:


> Or ECC88 (not sure if they are equivalent to 6CG7), which is what I ended up buying.



Both the ECC88 and 6CG7 have the same pinout as the 6H30 so an adapter with 6SN7 on top and any of these tubes on the bottom will work. But otherwise, they are not equivalent. The ECC88 is a premium version of the 6DJ8 and the 6CG7 is a 9-pin version of the 6SN7.


----------



## DylanF (Oct 17, 2017)

I want to thank all those answers everyone has provided on these easy (albeit a bit expensive) upgrades to my LDMKII.  I've had my MKII for a few years and use it daily. It deserves an upgrade. I've got the tubes/adapters on the way!  Thanks, Dylan

(what I meant by easy, is that no soldering is required...)


----------



## Hitogoroshichan

Has anyone ever tried using a 6n6p as a driver tube for their LD? I've seen schematics for other amps use them as preamp tubes so I was wondering if they'll work in my LD since they have the same pin out as all the other 6.3v 9 pin double triodes that I've tried and I use an external heater supply so the .9A heater current isn't a problem. I would have just tried them myself instead of asking here but I wasn't sure whether there was a reason I'd never seen anyone using them this way or not.


----------



## gibosi

I tried one as a driver on my LD 1+ and it worked fine.


----------



## i luvmusic 2

If my MK III can only push more BASS and a bit more MIDS into my HD 700 this amp should be perfect for this  bright headphone.


----------



## rexhu100

i luvmusic 2 said:


> If my MK III can only push more BASS and a bit more MIDS into my HD 700 this amp should be perfect for this  bright headphone.


Have you tried RCA 5654 driver tubes? They produce really good bass.


----------



## i luvmusic 2

Yes C3g,6SN7,6HM5,12@#7 but none can push the Bass the amp just can't do it.


----------



## rexhu100

i luvmusic 2 said:


> Yes C3g,6SN7,6HM5,12@#7 but none can push the Bass the amp just can't do it.



I think the RCA driver tubes have just the right amount of bass for my HD 600. That being said, I never heard the HD 700. Can these cans achieve good bass for you on other amps?


----------



## i luvmusic 2

Yes  specially with my DIY amp,with all the amp that i have only the MK III have the thinnest sound the treble is nice tho.


----------



## DylanF

Wow, amp porn, nice !


----------



## dobigstuff

i luvmusic 2 said:


> Yes C3g,6SN7,6HM5,12@#7 but none can push the Bass the amp just can't do it.


i luvmusic 2:
Here is my setup and I have the HD 700's.  Plenty of Bass and Power.


----------



## i luvmusic 2

Will the bass is there but nothing compares to my other setup.


----------



## Topodomain

Kind of noob question here, but does switching of tubes affect amp's capability to drive planars? Will tube rolling change output amperage? I've been drooling over LCD-2's or LCD-3's but for a fear of wife and wallet i cannot justify change of amp. Which of those (in other words, lower or higher impedance) would be better match for LD IV se? I'm running C3g's now, would 6sn7's or even 6080's with external power source help?


----------



## unclebrudy (Oct 29, 2017)

Topodomain said:


> Kind of noob question here, but does switching of tubes affect amp's capability to drive planars? Will tube rolling change output amperage? I've been drooling over LCD-2's or LCD-3's but for a fear of wife and wallet i cannot justify change of amp. Which of those (in other words, lower or higher impedance) would be better match for LD IV se? I'm running C3g's now, would 6sn7's or even 6080's with external power source help?


While certain tubes can push a bit louder volume than others, your MKIV isn't designed to push low-efficiency planars, plain and simple. Look into hybrid tube amps like the Lyr/Lyr 2 if you want to continue on your tube journey, or a solid state amp if your heart is set on a planar such as the LCD line.


----------



## Acapella11

Topodomain said:


> Kind of noob question here, but does switching of tubes affect amp's capability to drive planars? Will tube rolling change output amperage? I've been drooling over LCD-2's or LCD-3's but for a fear of wife and wallet i cannot justify change of amp. Which of those (in other words, lower or higher impedance) would be better match for LD IV se? I'm running C3g's now, would 6sn7's or even 6080's with external power source help?



Dear Topodomain, I had the Hifiman HE-500 and I have the LCD-XC and both work with 6H6N and 6H30P Type tubes but not so well with 6SN7 tubes, especially the HE-500. For 6080, you would need to read the output power specs. I think the LCD-X are easier to drive than 2 or 3 though but I also much prefer them over 2s and I prefer the signature over 3s.
I agree that it is a good idea to buy your Perfect headphone in the beginning and then build the system around it. My favourite is the HD800 (not HD800S) and the Beyerdynamic T1 is smother great dynamic headphone. Both of these are perfect with tube amps and also the right solid state amp. Even though I like the planar sound a lot, I still slightly prefer the dynamic driver sound which I find a bit sharper for details.
However, if you are eyeballing more with planars, my wholehearted suggestion goes to a Chord Mojo, which then also acts as an amazing DAC for your LD.
Enjoy your journey of sounds


----------



## rexhu100

Topodomain said:


> Kind of noob question here, but does switching of tubes affect amp's capability to drive planars? Will tube rolling change output amperage? I've been drooling over LCD-2's or LCD-3's but for a fear of wife and wallet i cannot justify change of amp. Which of those (in other words, lower or higher impedance) would be better match for LD IV se? I'm running C3g's now, would 6sn7's or even 6080's with external power source help?



I tried HE560 on my LD III, and it sounded terrible. HE560 is rated 90db on sensitivity. I also tried the Fostex t-x0(95db), and it sounded OK. I'm not quite sure what the sensitivity is on the LCDs, but I think it is generally a bad idea to use cans with low impedance and low sensitivity on LD III.


----------



## araxiscentauri

Hi all, just a question...I have a Little Dot MK3 and a spare pair of 6H1N-EB power tubes. Are those tubes compatible? I don't want to try them out as I'm scared it'll damage the amp. Thanks for your help in advance.


----------



## jamesbdh

So I broke my power tubes. I was using the 6hm5 with what looks like 6n6p-IR.  Does anyone have a better suggestion or place to get replacements reasonably?


----------



## mordy

jamesbdh said:


> So I broke my power tubes. I was using the 6hm5 with what looks like 6n6p-IR.  Does anyone have a better suggestion or place to get replacements reasonably?


Hi jamesbdh,

Sorry to hear that - how did the tubes break? From being incompatible with the amp or dropping them?
In the past I tried a number of variants of the standard 6N6P power tubes. Even though the IR tubes sounded the best (did not try the DR tubes because the prices went through the roof), the regular inexpensive power tubes sound quite good.
However, if you would buy suitable adapters and any 6SN7 tubes you will get better sound from the Little Dot amp than the OEM power tubes.


----------



## jamesbdh

mordy said:


> Hi jamesbdh,
> 
> Sorry to hear that - how did the tubes break? From being incompatible with the amp or dropping them?
> In the past I tried a number of variants of the standard 6N6P power tubes. Even though the IR tubes sounded the best (did not try the DR tubes because the prices went through the roof), the regular inexpensive power tubes sound quite good.
> However, if you would buy suitable adapters and any 6SN7 tubes you will get better sound from the Little Dot amp than the OEM power tubes.


Apparently my headphone cord was around the tube when I went to put them on.  I saw the post above about the adapters but looks like it would be almost $60 for the tubes and adapters?


----------



## rexhu100

jamesbdh said:


> So I broke my power tubes. I was using the 6hm5 with what looks like 6n6p-IR.  Does anyone have a better suggestion or place to get replacements reasonably?



Definitely get the 6sn7 if you have the money. I can't quite hear the difference among various 6n6p tubes, but 6sn7 makes a big difference.


----------



## rexhu100

jamesbdh said:


> So I broke my power tubes. I was using the 6hm5 with what looks like 6n6p-IR.  Does anyone have a better suggestion or place to get replacements reasonably?



This is what I'm currently using


----------



## jamesbdh (Oct 30, 2017)

rexhu100 said:


> This is what I'm currently using


Looks like the tubes I found on eBay were used. So $60 for the tubes any cheaper on the adapters? Almost as much as what I paid for the amp lol

https://m.ebay.com/itm/2-NOS-Matche...rome-Dome-Audio-Tubes-USA-1950s-/202092964603


----------



## rexhu100

jamesbdh said:


> Looks like the tubes I found on eBay were used. So $60 for the tubes any cheaper on the adapters? Almost as much as what I paid for the amp lol
> 
> https://m.ebay.com/itm/2-NOS-Matche...rome-Dome-Audio-Tubes-USA-1950s-/202092964603



I think the price is pretty good for these (if they are indeed NOS). It is unfortunate that good tubes cost an arm and a leg, but for pure tube driven amp, it often does make a difference.


----------



## unclebrudy

rexhu100 said:


> This is what I'm currently using


Would you be so kind as to elaborate on why you're running these power tubes, and how they compare to say, tubes that don't need adapters? Thanks.


----------



## mordy

rexhu100 said:


> I think the price is pretty good for these (if they are indeed NOS). It is unfortunate that good tubes cost an arm and a leg, but for pure tube driven amp, it often does make a difference.


Hi jamesbdh,

There are very good sounding 6SN7 equivalents that are quite inexpensive and really underrated: The Russian 6N8S/6H8C. 

https://www.ebay.com/sch/i.html?_fr....TR5.TRC4.A0.H1.X6N8S.TRS1&_nkw=6n8s&_sacat=0

I paid less than $8 for a pair including shipping, and I use them every day. ATM I can't find the seller, but you will find similar low prices in the link above. I have several Sylvania 6SN7 variants and IMHO the 6N8S stand up very well in comparison.


----------



## rexhu100

unclebrudy said:


> Would you be so kind as to elaborate on why you're running these power tubes, and how they compare to say, tubes that don't need adapters? Thanks.



I have tried the Russian 6N6P (stock), Russian 6N6P-IR, and Shuguang 6N6-T. Keep in mind that these tubes get extremely hot when operating, so when I'm comparing them among themselves or against 6SN7 tubes, I have to wait a few minutes before switching tubes. Also, the newly inserted tubes need about half a minute to heat up to operating temperature. I'm emphasizing these aspects because I don't have very good 'hearing memories', so it is entirely possible that some details in the difference is lost when I'm waiting/switching. So take my opinion with a grain of salt. Also, I used VE Zen 2.0 and HD 600 for the audition.

That being said, I believe here is a significant improvement in sound quality moving from stock 6N6P to 6N6P-IR, and again form 6N6P-IR to 6SN7. Also, the improvements are more noticeable on HD 600 than Zen, probably due to the change in sensitivity, among other factors. 

The biggest improvement is the tonal clarity across the frequency range. The sound is just more crisp to my ears. Another big improvement is the reduced harshness in the treble. This is especially noticeable on the HD 600 where I have to turn up the volume. HD 600 can be fatiguing sometime, mostly due to the harshness in the high. This is the case before switching to 6SN7. With 6N6* tubes, the cymbals or high octave guitar will pierce my eardrum at the volume where I find bass and mid are appropriate. Also, the sound of the cymbals sounds muddled/distorted in some rock/jazz tracks. This improvements is less pronounced on the VE Zen. My theory is that Zen is a lot more sensitive than HD 600, and I don't need to turn the pot as high to produced the same perceived volume to my ears. The 6N6* tubes just won't hold up at a higher output level.

I have multiple sets of 6SN7 tubes, but I haven't gotten around to fully audition them all. I'll post my impressions on them later.


----------



## rexhu100

jamesbdh said:


> Looks like the tubes I found on eBay were used. So $60 for the tubes any cheaper on the adapters? Almost as much as what I paid for the amp lol
> 
> https://m.ebay.com/itm/2-NOS-Matche...rome-Dome-Audio-Tubes-USA-1950s-/202092964603



On a side note, the 6SN7 tubes are widely used in various amps. Even if you upgrade to a better amp (WA5, IHA-1, Eddie Current Balancing Act, etc.) later, these tubes will keep improving the sounds on those bigger guys.


----------



## unclebrudy

rexhu100 said:


> I have tried the Russian 6N6P (stock), Russian 6N6P-IR, and Shuguang 6N6-T. Keep in mind that these tubes get extremely hot when operating, so when I'm comparing them among themselves or against 6SN7 tubes, I have to wait a few minutes before switching tubes. Also, the newly inserted tubes need about half a minute to heat up to operating temperature. I'm emphasizing these aspects because I don't have very good 'hearing memories', so it is entirely possible that some details in the difference is lost when I'm waiting/switching. So take my opinion with a grain of salt. Also, I used VE Zen 2.0 and HD 600 for the audition.
> 
> That being said, I believe here is a significant improvement in sound quality moving from stock 6N6P to 6N6P-IR, and again form 6N6P-IR to 6SN7. Also, the improvements are more noticeable on HD 600 than Zen, probably due to the change in sensitivity, among other factors.
> 
> ...


You're awesome. Thanks for taking the time to write that up!

I currently have the MK2 with the tubes in my sig, and they're less than 2 hours burned in and I'm missing extension on both ends of the FR, which is contradictory to what I've read about these two sets of tubes. (Mind you, I'm very new to tube-rolling and could have completely read the wrong thing.) If, after a full burn-in, I still feel these tubes lacking, I will look into what you have discussed.

Thanks again. It's really appreciated.


----------



## dobigstuff

rexhu100:

See below for what I have finally settled on for my Little Dot III.  This is one of the best combos out there.  (I have the HD 700's)







Little Dot III w/ NOS USA Tung-Sol Tall Bottle 6SN7 GTB Power Tubes and Siemens C3G Driver Tubes


----------



## rexhu100

dobigstuff said:


> rexhu100:
> 
> See below for what I have finally settled on for my Little Dot III.  This is one of the best combos out there.  (I have the HD 700's)
> 
> ...



That's a pretty sick setup. Mine is similar


----------



## J Mirra (Oct 31, 2017)

Hi guy's I have an MK11 with C3g & 6N6P-IR and love the sound right now.

What differences would I hear if I bought some 6SN7GTB with the adapters? Can you describe what makes them a better choice than the 6N6P-IR?

What are the audible differences between brands if any?

I see some are quite cheap then some are more expensive.

Thank you.


----------



## gulakpii

And I ended up with something very similar!


----------



## OctavianH

I've seen that everyone who remained on C3G + 6SN7 uses MK3. I tried this combo on MK2 and I was not very pleased. 
And the circuitry of the models is not the same. I remember that I had to change also Gain settings to avoid some unpleasant buzzing on both channels. 
*What I try to say:* I think that the combo is great, but only on MK3 which is more powerful, on MK2 you might not have the same experience as other users. 

I am very curious to see if someone tries this combo on MK2 and has the same pleasant surprise as those with MK3.


----------



## J Mirra

I get buzzing on the lowest gain setting with the C3G, but any other setting and it is fine, it may be the tube it may be the adaptor.


----------



## OctavianH

J Mirra said:


> I get buzzing on the lowest gain setting with the C3G, but any other setting and it is fine, it may be the tube it may be the adaptor.



Exactly, same here. I set Gain = 5 and all was fine, but I still preferred Voskhods + 6N6P-IR. Most probabily the circuitry was not designed for C3G instead of a tube/adapter problem.


----------



## J Mirra (Oct 31, 2017)

OctavianH said:


> Exactly, same here. I set Gain = 5 and all was fine, but I still preferred Voskhods + 6N6P-IR. Most probabily the circuitry was not designed for C3G instead of a tube/adapter problem.


I had the Mullard 8100 & the 6N6P-IR , I find that the CG3's are much better.

You can drive them louder than the 8100's without the image becoming shouty .


----------



## dobigstuff

The best non 6SN7/C3G setup for the Little Dot MK III that I used was this:

Electro-Harmonix 6H30PI Power Tubes and NOS Telefunken 5654 Driver Tubes.


----------



## gulakpii

While the C3G + Shuguang "coke-bottle" 6SN7 combo is great with my HD650, I experienced some distortions when using my low-Z AKG K712.
The stock 6H30Pi on my Mk4 performs best with the 6HM5 when I listen to my K712.
That is just my own experience and YMMV.


----------



## Acapella11

gulakpii said:


> While the C3G + Shuguang "coke-bottle" 6SN7 combo is great with my HD650, I experienced some distortions when using my low-Z AKG K712.
> The stock 6H30Pi on my Mk4 performs best with the 6HM5 when I listen to my K712.
> That is just my own experience and YMMV.


This agrees with my finding that the 6SN7 does not work with the HE-500 but the 6H30P and 6N6P-IR do.
Btw., I had 6H30P-DR tubes from 1984 I believe, which outperformed my 6SN7 tubes and they also allow lower Z cans but it is quite a steep price point for those. However, that was my best power tubes (without external power) and they ran with C3Gs.
The obvious cheap solution to get your MKIII on steroids are 6HM5 with 6N6P-IR.
YMMV


----------



## Caribou679

Acapella11 said:


> The obvious cheap solution to get your MKIII on steroids are 6HM5 with 6N6P-IR.



Is this also good for the MK IV SE ?


----------



## gulakpii

I have the 6HM5 running with the 6H30Pi.  In my opinion, this combo sounds a tad better than the 6N6P-ir which I also have, but again, YMMV depending on what kind of cans you have.
The 6H30Pi are stock tubes that came with my LD Mk4 (not SE)!

The 6HM5 is warm and airy which I like much.  It probably is the best value for your money before you move onto the more pricy C3g.


----------



## TrollDragon

gulakpii said:


> I have the 6HM5 running with the 6H30Pi.  In my opinion, this combo sounds a tad better than the 6N6P-ir which I also have, but again, YMMV depending on what kind of cans you have.
> The 6H30Pi are stock tubes that came with my LD Mk4 (not SE)!
> 
> The 6HM5 is warm and airy which I like much.  It probably is the best value for your money before you move onto the more pricy C3g.


I run the exact same setup in my Mk IV, the 6HM5's are a great bang for your buck.


----------



## rexhu100

I like the sound of RCA 5654 too. Really good bass. I was told M8100 is even better in that regard, but I haven't tried it.


----------



## Acapella11

Caribou679 said:


> Is this also good for the MK IV SE ?


Yes


----------



## Caribou679

Acapella11 said:


> The obvious cheap solution to get your MKIII on steroids are 6HM5 with 6N6P-IR.
> YMMV



Thanks! I just ordered :
LOT OF 2 .
 Russian (USSR) triode tube 6N6P-IR for Hi-End amplifying in audio amplifiers.
NEW/ NOS.
 NOVOSIBIRSK  plant. 
Awaiting for Best Offer on 6HM5.

Not That cheap: $42 US for 6N6P-IR, and about $15 US for 2 X 6HM5

regards,


----------



## jamesbdh

gulakpii said:


> I have the 6HM5 running with the 6H30Pi.  In my opinion, this combo sounds a tad better than the 6N6P-ir which I also have, but again, YMMV depending on what kind of cans you have.
> The 6H30Pi are stock tubes that came with my LD Mk4 (not SE)!
> 
> The 6HM5 is warm and airy which I like much.  It probably is the best value for your money before you move onto the more pricy C3g.



Do you have to change any settings from the 6N6P-IR? Looking at these as a cheaper option then redoing all the tubes right now.


----------



## gulakpii

No!  You don't need to change any settings to run the 6H30Pi and the 6N6P or the 6n6P-ir.
If you want to try the 6SN7 etc., you will need adapters, but you still don't need to change settings on the amplifiers.
In fact, the jumpers on the LD MkII, III, IV are for the driver tubes, not for the power tubes.


----------



## rexhu100

I have a questions about 6HM5. What is the jumper setting on MKIII when using 6HM5 tubes?


----------



## OctavianH

EF95, just like the ones you had when you bought it.


----------



## rexhu100

OctavianH said:


> EF95, just like the ones you had when you bought it.



Thanks!


----------



## grig

AlexRoma said:


> Impulsive, Voshkod 6ZH1P-EV = mine 6J1P-EV .  The trick is getting the ones made from 1970 to 1980.
> 
> Take in consideration, the tubes on ebay called 6ZH1P-EV are 10 times more expensive (30$ for a matched pair).
> 
> ...


so basically the Voshkod 6ZH1P-EV is = 6J1P-EV ? cause i found a russian guy on ebay that sells a pack of 10 6J1P-EV for $20 shipped otherwise for still $20 shipped i can get only 2 6ZH1P-EV...


----------



## Oskari

grig said:


> so basically the Voshkod 6ZH1P-EV is = 6J1P-EV ? cause i found a russian guy on ebay that sells a pack of 10 6J1P-EV for $20 shipped otherwise for still $20 shipped i can get only 2 6ZH1P-EV...





Oskari said:


> The Russian designation is 6Ж1П-ЕВ.
> 
> 6Zh1P-EV and 6J1P-EV are merely transliterations of that.


----------



## grig

there's fake on ebay of this tubes, or the price looks allright ?


----------



## Oskari

grig said:


> there's fake on ebay of this tubes, or the price looks allright ?


The tubes are inexpensive, hardly worth faking. Check that you see 6Ж1П-ЕВ in the photos.


----------



## grig

Oskari said:


> The tubes are inexpensive, hardly worth faking. Check that you see 6Ж1П-ЕВ in the photos.


i thought so... they are still in production or it's pretty much all new old stock ?


----------



## Oskari

grig said:


> they are still in production


Unlikely.


----------



## grig

Oskari said:


> Unlikely.


thanks mate, can't wait to test them in my little elemental amp


----------



## grig

.


----------



## Highend75

Adam2211 said:


> Does anywhere know where I can buy these tubes in the UK?
> 
> Thanks.


https://www.watfordvalves.com


----------



## Highend75

siles1991 said:


> I feel that davidzhezhe communication is really slow...I've waited an entire day for a respond than I replied him the same minute I got the response and I have to wait until tomorrow for another respond. Does he only open his email once a day for few minutes? I've already requested twice for him to send me the invoice for the little dot and its been 3 days, he responded to my email but didn't send me the invoice...


Same experience here, sometimes takes days.


----------



## grig

just an information guys, i recently bought a couple of mullards on ebay for $20aud and the seller sent me actually 4 rather than two but i'm just concerned that actually those might be a fake. i don't have previous experience perhaps is just me.... here are few pictures


----------



## gibosi (Nov 21, 2017)

Mullard was a wholly owned subsidiary of Philips. So.... can you see the Philips production code? This should be a 7-digit code etched into the glass on the side of the tube near the pins.

http://tubedata.milbert.com/other/Philips/PhilipsCodeListAB-v10.pdf

Otherwise, I am inclined to think that these tubes were actually manufactured by RTC (La Radiotechnique) located in Suresnes, France, as is indicated by the labeling.

And no, I seriously doubt that these are fakes. The 5654 is too cheap to be worth the trouble. But unless they bear Mullard production codes, then I might think that the seller misrepresented these tubes. On the other hand, many sellers don't know all that much about the tubes they sell, and the seller may well think that they are Mullards. But again, the Philips production code, if it exists, will tell the story.


----------



## grig

gibosi said:


> Mullard was a wholly owned subsidiary of Philips. So.... can you see the Philips production code? This should be a 7-digit code etched into the glass on the side of the tube near the pins.
> 
> http://tubedata.milbert.com/other/Philips/PhilipsCodeListAB-v10.pdf
> 
> ...


There's no Philips production code, the only thing i could find is a letter at the bottom we're the pins are located right in the middle. Two of them are "Z" and the other two are "L" on the other hand on the plastic cap on the external side theres an "EPL 7" on all 4 plastic caps and i have no idea if this could mean anything at all.....


----------



## gibosi

Since there are no Philips codes, I am inclined to believe that these were not manufactured by Mullard. But I wonder if I am reading "8318" correctly....  If so, this might be a date code, 18th week of 1983. And if these really were manufactured in the early 1980's, there weren't many vacuum tube factories still operating in Western Europe. Again, perhaps RTC did in fact manufacture them in France. But it is also possible that they could have been manufactured somewhere else, and then labeled and sold by RTC.

In the end, you may never know for sure who manufactured them and where. But as long as they sound good, it shouldn't matter.


----------



## grig

gibosi said:


> Since there are no Philips codes, I am inclined to believe that these were not manufactured by Mullard. But I wonder if I am reading "8318" correctly....  If so, this might be a date code, 18th week of 1983. And if these really were manufactured in the early 1980's, there weren't many vacuum tube factories still operating in Western Europe. Again, perhaps RTC did in fact manufacture them in France. But it is also possible that they could have been manufactured somewhere else, and then labeled and sold by RTC.
> 
> In the end, you may never know for sure who manufactured them and where. But as long as they sound good, it shouldn't matter.


indeed on the label is 8318, the sound is not bad is not as good as the previous GE JAN 5654W so far.... Some "effects" present in some musical mix like some instrument are presented differently, better/worst is to soon to say that i just started my testing session....


----------



## Oskari

gibosi said:


> In the end, you may never know for sure who manufactured them and where.


Whoever it was, they had access to Philips tooling.


----------



## mattrudy80

Please forgive me if this has already been answered. Is there any difference between 6ZH1P-EV and the non - EV variant?


----------



## grig

Oskari said:


> Whoever it was, they had access to Philips tooling.


too bad that there's no way to say that for sure .....


----------



## Oskari

grig said:


> too bad that there's no way to say that for sure .....


There's plenty of way to say that for sure.


----------



## gibosi

grig said:


> too bad that there's no way to say that for sure .....



Tubes manufactured with Philips equipment have construction characteristics that are unique to Philips and easy to recognize. So tubes manufactured by Philips subsidiaries, such as Valvo, RTC, Mullard and Amperex all share the same construction details.

Later, as Philips exited the vacuum tube business they often sold their factory equipment to other companies, for example, EI (Elektronska industrija Niš) in old Yugoslavia. And therefore, even though EI tubes were not manufactured by Philips, they are said to have "Philips tooling".

Going back to your RTC 5654, apparently manufactured in the 1980's... If they were not actually manufactured by RTC, the tooling suggests that they were manufactured using Philips equipment. But again, the actual factory and its location remains a mystery....


----------



## Oskari

gibosi said:


> Tubes manufactured with Philips equipment have construction characteristics that are unique to Philips and easy to recognize. …


Thanks for the longer version.


----------



## mordy

mattrudy80 said:


> Please forgive me if this has already been answered. Is there any difference between 6ZH1P-EV and the non - EV variant?


These are Russian tube designations - because the Cyrillic alphabet is used the translation has some variants. 
As far as I know the EV (EB) designation indicates longer life - 5000 hours. Otherwise the tubes should be the same. The DR designation indicates 10,000 hour life.
A regular tube should last approximately 3000 hours. The IR designation is only rated 500 hours, but it could mean in conditions in a tank and not an amp......


----------



## mordy

Oskari said:


> Thanks for the longer version.


In the early 50's National in Japan (Matsushiiita/Panasonic) bought tooling from Philips. As Oskari discovered, certain German tubes were made in Japan.


----------



## Oskari

mordy said:


> In the early 50's National in Japan (Matsushiiita/Panasonic) bought tooling from Philips.


It seems that Matsush¡ta may have actually made 6AK5s. 

No, I'm not saying that @grig's RTCs were made by Matsush¡ta.


----------



## grig

Oskari said:


> There's plenty of way to say that for sure.


like ???


----------



## Oskari

grig said:


> like ???


The seams on top. The way the tip was shaped.


----------



## gibosi

Here's a fairly good example of Philips tooling -- the four seams at the top and the shape of the tip:

An E91H / 6687 (Philips production code: 3L7 ⊿2L4)


----------



## Scutey

mattrudy80 said:


> Please forgive me if this has already been answered. Is there any difference between 6ZH1P-EV and the non - EV variant?


Hi mattrudy80,

I think you will find that most if not all 6ZH1P have the suffix EV. I have several pairs of 6ZH1P and they all have EV on the end.


----------



## rexhu100

Learned a lot about tubes in the recent posts!


----------



## Scutey

rexhu100 said:


> Learned a lot about tubes in the recent posts!


When I got my LD I found this thread, and others absolutely invaluable. Some of the older posts are also full of useful info too.


----------



## grig

gibosi said:


> Here's a fairly good example of Philips tooling -- the four seams at the top and the shape of the tip:
> 
> An E91H / 6687 (Philips production code: 3L7 ⊿2L4)


mine is quite different, and i will put two picture and in case i can take many more....


----------



## Oskari

grig said:


> mine is quite different, and i will put two picture and in case i can take many more....


Different but same…


----------



## grig

Oskari said:


> Different but same…


the internal structure looks similar or almost the same, but is the sound as well .... ?


----------



## gibosi

From factory to factory, there are often small differences in the way Philips tooling was implemented. For example, in some factories, all four seams are not equally prominent and it appears that there are only two seams.

With regard to the internal structure of a tube, for example, an EF95 / 6AK5, again, there are often small differences from factory to factory, even though they are all constructed according to the instructions provided by Philips.

But no, tubes manufactured in different factories do not sound the same even though they appear to have the same construction. Since Philips purchased existing companies, for example Mullard, then one might say that the original company's "DNA" remains in that factory. And this residual "DNA" explains why tubes manufactured by Mullard sound different than those manufactured by Valvo, in Hamburg, Germany, or by Philips, in Heerlen, Holland.


----------



## mattrudy80

I picked up a lot of 6 International Servicemasters marked EF91/6AM6 GT BRITAIN. At first glance they appeared to be Mullard EF91 but I could not find any Mullards that had the tab bent up towards the top getter. Any help identifying would be much appreciated as they sound great.


----------



## gibosi

Do you see Mullard production codes on this tube?


----------



## mattrudy80

Other markings I found:       Thanks gibosi!


----------



## mattrudy80

mattrudy80 said:


> Other markings I found:       Thanks gibosi!


2nd marking says E42.


----------



## gibosi

E42 doesn't seem to correspond to a Mullard production code....

So I have no idea what factory manufactured these tubes....


----------



## Oskari

Could be BEL, India. They seem to have made the type and sometimes used nonstandard codes.


----------



## mattrudy80

Oskari said:


> Could be BEL, India. They seem to have made the type and sometimes used nonstandard codes.


Thanks. I'll see if I can find any that are similar. The closest I have found so far that physically look similar with the tab bent up towards the getter are Sylvanias.


----------



## mordy

mattrudy80 said:


> Thanks. I'll see if I can find any that are similar. The closest I have found so far that physically look similar with the tab bent up towards the getter are Sylvanias.


Hi m80,
Try Google images - type in the tube designation and scroll through the pictures; you may find what you are looking for.
I had a different Channel Master tube that said Japan, and I finally found a NEC tube that was identical so I found out who made it.


----------



## Oskari

mattrudy80 said:


> Thanks. I'll see if I can find any that are similar. The closest I have found so far that physically look similar with the tab bent up towards the getter are Sylvanias.


BELs on ebay:

https://www.ebay.ie/itm/True-NOS-NI...-6AM6-EF91-Silver-Plate-Tube-100/152793008598
https://www.ebay.ie/itm/True-NOS-NI...nics-India-CV138-6AM6-EF91-Tubes/152792995962
https://www.ebay.ie/itm/True-NOS-NI...nics-India-CV138-6AM6-EF91-Tubes/152793012824


----------



## mattrudy80

New set in today! Can't wait to give em a try.


----------



## mattrudy80

mattrudy80 said:


> New set in today! Can't wait to give em a try.


Amazing how Tung Sol JAN-6AJ5 from '44 sound so much better than Tung Sol JTL-6AJ5 form '56.


----------



## mattrudy80

Anyone have any experience with National Union 6AG5's? I found an old pair that look new at a surplus store and didn't expect much, wasn't even sure if they worked. Thus far in my tube rolling journey these are by far the most relaxed sounding, great for male vocals such as Ray lamontagne and seem to be a good all arounder.


----------



## mattrudy80

Something I cooked up today. 1-7, 2-7, and 6-7 pin strapping socket saver. Number two is in the hopper. I'll give 'em a proper test later tonight.


----------



## sghound

does anybody know what the difference is between v2 and v3 of the mk2 circuit board?


----------



## xenithon

Quick question - has anyone used the 6SN7  (or similar) tubes in place of the 6H30P in the MkVIII / Mk8 and, if so, which adapters did you use?


----------



## Scutey

Don't know about the mk8 but you can in the mkiii, you need 6sn7 to ecc88 adapters, here's a couple pics.


----------



## bjj51

Would the ld3 work with sensitive headphones like the fostex x-00 or would I have to get an ss amp?


----------



## Scutey

I


bjj51 said:


> Would the ld3 work with sensitive headphones like the fostex x-00 or would I have to get an ss amp?


 I used my 32 ohm Beyer 990 on my LD mkiii without any problems, you don't say what amp You're using?.


----------



## dobigstuff

You can also adjust the Gain to allow for sensitive Headphones.


----------



## HungryPanda

I have used mine with my Little Dot II on low gain


----------



## bjj51

Scutey said:


> I
> 
> I used my 32 ohm Beyer 990 on my LD mkiii without any problems, you don't say what amp You're using?.



I'm using the little dot mkiii, just bought a used fostex tx-00


----------



## Scutey

bjj51 said:


> I'm using the little dot mkiii, just bought a used fostex tx-00


As others have said either of the two lowest gain settings should work well.


----------



## bjj51

Thanks for the reassurance guys


----------



## vampirehunterd

bjj51 said:


> fostex x-00



I have the LD Mk3 and recently my headphone collection transitioned to low impedance cans (Audioquest Nighthawk/Nightowl @ 25 Ohm).  The sound from the Mk3 was good but suboptimal (to my ears) so I tracked down a used LD Mk1+ and like the sound much better for those particular 25 Ohm headphones.  I'm also using one of Garage1217's attenuation adapters so the volume control is usable over a greater range versus 25% or less maxing out the volume level my ears can tolerate.  The adapter has also dropped the noise floor tremendously on the LD amps.

For me it was definitely well worth $100-130 to track down a LD Mk1+ and I was fortunate to find a used one with several great sets of tubes and an upgraded opamp.  I actually bought two (one from Head-Fi and one from Ebay).  One had the LT1364 opamp and some great 408 tubes while the other had the opa2107 with tong sol and voshkod tubes.  To my ears it's a pretty dramatic improvement for the NH/NO over what I heard out of the Mk3.


----------



## jasonlookhope

Thanks for this wonderful guide


----------



## Scutey

jasonlookhope said:


> Thanks for this wonderful guide


If you have a LD this thread is a mine of info, plenty to read for a long time, I found it invaluable.


----------



## dobigstuff

I agree with Scutey!!


----------



## gulakpii

I've spent months reading this entire thread carefully!   The time spent was well worth!


----------



## caenlenfromOCN

I just bought LittelDotII from massdrop and paid extra $20 to upgrade to JAN5654  but it doesn't have the W next to it like the review on this first post of this topic does... so can anyone confirm for me that that I will indeed be getting the best rated one of the three listed below? im tempted to pay $25 more on top of the $20 more for the Mullards... but I am not sure, heh.



3.5 GE 5654

GE is one of the most widely available manufacturer of the EF95 family of tubes and comes stock with many LD amps.  Sound quality is average with a more upfront in-your-face sound.  Listening to the notoriously close-mic’d Jack Johnson’s “On and On” can be a claustrophobic experience with these tubes due to its up front qualities but chamber music is complimentary.
                Bass: 12
                Mid: 15
                Treble: 13
                Detail: 13
                Soundstage: 10
                Total: 63/100

3.6 GE 5Star 5654

These hand-picked broadcast quality tubes are surprisingly unlike the standard GE tubes. I like these tubes for their evenness and silence which really lets you focus your mind on the music, and their soundstage is even and expansive as long as you have a matched pair.  I find myself tapping my toes listening to music with these tubes.
                Bass: 17
                Mid: 16
                Treble: 17
                Detail: 19
                Soundstage: 18
                Total: 87/100

3.7 GE JAN5654W

These military spec tubes really have a sense of quality construction about them.  The first thing I noticed about these tubes when they arrived is just how neat and solid its internals look.  Their sound doesn’t disappoint either with incredibly good treble extension, clarity and quietness that reminds me of the GE 5 Star tubes reviewed above.  Its upfront sound is in keeping with the GE family sound, violins sounded desperately beautiful with these tubes. In the bass department, PRAT and OOMPH are the first adjectives that come to mind. Compared to the Mullard M8100, these tubes are airier and their bass not as soupy.  These tubes also have exceptionally clean vocal and lends itself well to modern jazz recordings such as Eva Cassidy’s “Live at Blues Valley” where the reverb of the room is clearly audible.
                Bass: 19
                Mid: 19
                Treble: 20
                Detail: 18
                Soundstage: 17
                Total: 93/100


----------



## Whelkie D

caenlenfromOCN said:


> I just bought LittelDotII from massdrop and paid extra $20 to upgrade to JAN5654  but it doesn't have the W next to it like the review on this first post of this topic does... so can anyone confirm for me that that I will indeed be getting the best rated one of the three listed below? im tempted to pay $25 more on top of the $20 more for the Mullards... but I am not sure, heh.
> 
> Not sure whether the "W" makes a difference. Do they have green writing on them?


----------



## caenlenfromOCN

I have no way of knowing if they have green writing, I just backed it on massdrop.


----------



## buldogge

caenlenfromOCN said:


> I have no way of knowing if they have green writing, I just backed it on massdrop.



Skip past trying all of those tubes, and go straight to one of these:

-Mullard M8083
-6HM5/6HQ5 (no adapters needed)
*-or preferably* C3Gs (adaptors needed)

Save the $$$ a lot of us spent rolling far too many tubes...My 2c.

-Mark in St. Louis


----------



## gibosi

In my opinion, the GE 5654, GE 5654W and GE 5Star 5654 are all the same tube. GE did not manufacture multiple versions of the 5654. The 5654 was designed to be more shock and vibration resistant than the 6AK5 for use in severe operating environments, such as in an industrial factory setting or the military theater.

Again, in my opinion, the differences the reviewer heard are largely due to the fact that these tubes were very likely manufactured at different times. For example, in my experience, a tube manufactured in 1950 will often sound slightly different compared to tubes manufactured in the same factory in 1955, 1960 or 1965. 

Over the years, the materials and processes used in the fabrication of vacuum tubes changed and as a result, the sound also changed. In the beginning, when tubes were state-of-the-art, changes were made to improve their performance. But towards the end of the tube era, changes were made to reduce costs. And since the 5654 was not designed for use as an audio amplifier, it is impossible to predict how these changes might play out in an audio circuit.

So again, in my opinion, the fact that the reviewer did not specify the date of manufacture makes his review relatively worthless. We do not know precisely which tubes he evaluated.

My advice: Obtain several GE 5654, ranging from the earliest, around 1948, to the latest, around 1980, and judge for yourself which sound best in your system.


----------



## dobigstuff

Happy Rolling


----------



## Scutey (Jan 14, 2018)

For refinement and detail it's the C3G's, for tubes that don't need an adapter my fave has always been the Mullard m8100, great bass with these.


----------



## Scutey

dobigstuff said:


> Happy Rolling


Great pic dobigstuff


----------



## dobigstuff

Scutey said:


> Great pic dobigstuff


Thanks Scutey


----------



## mordy

buldogge said:


> Skip past trying all of those tubes, and go straight to one of these:
> 
> -Mullard M8083
> -6HM5/6HQ5 (no adapters needed)
> ...


Hi bd,

Concur 100% - just wanted to add that the 6HM5/6HQ5 may be the least expensive of these - if you shop carefully only a couple of bucks a piece.


----------



## Scutey

I've been thinking the unthinkable, selling my LD, would not have considered it six months ago, dare I say it, I need the funds for my Feliks Elise.


----------



## gibosi

I hear you...  I haven't listened to my LD1+ since the Glenn OTL arrived on the scene...  about three years ago...

And as I was shoveling about 6 inches of snow today, for some reason, it popped into my head that maybe I should sell the LD1+, including all the tubes, several hundred I would guess, and adapters, as a package deal... Again, I have just begun to think about it... Haven't made a decision yet....


----------



## buldogge

mordy said:


> Hi bd,
> 
> Concur 100% - just wanted to add that the 6HM5/6HQ5 may be the least expensive of these - if you shop carefully only a couple of bucks a piece.



Agreed...and really, a great way to go if on a budget...a great full sound IMHO.

-Mark


----------



## Scutey

gibosi said:


> I hear you...  I haven't listened to my LD1+ since the Glenn OTL arrived on the scene...  about three years ago...
> 
> And as I was shoveling about 6 inches of snow today, for some reason, it popped into my head that maybe I should sell the LD1+, including all the tubes, several hundred I would guess, and adapters, as a package deal... Again, I have just begun to think about it... Haven't made a decision yet....


I haven't decided yet, it probably makes sense as It has not been used for several months, had many happy hours with my MKIII though, but I'm after another pair of Tung Sol 5998 and they are not cheap, decisions, decisions...


----------



## attmci

gibosi said:


> I hear you...  I haven't listened to my LD1+ since the Glenn OTL arrived on the scene...  about three years ago...
> 
> And as I was shoveling about 6 inches of snow today, for some reason, it popped into my head that maybe I should sell the LD1+, including all the tubes, _*several hundred*_ I would guess, and adapters, as a package deal... Again, I have just begun to think about it... Haven't made a decision yet....




Ken, no wonder you cannot find the tube you are looking for. LOL


----------



## gibosi

Between the LD and the OTL, I have well over 1000 tubes. lol


----------



## i luvmusic 2

I've been trying to sell my MK III with all the tubes with it so far no luck most buyers in my area only want the amp,selling the amp is easy but the tubes or with all the tubes aint easy for me,cheap bustards....


----------



## Scutey

gibosi said:


> Between the LD and the OTL, I have well over 1000 tubes. lol


That's an impressive number!


----------



## capetownwatches

TrollDragon said:


> Power tubes is a bit of a misnomer, the LD amplifiers are really just preamps.
> 
> The matching of power tubes is required in Push/Pull configurations where both tubes are required to draw the same amount of current. The output tubes of the LD amps are configured in a Cathode Follower configuration and tube matching is not required.



I don't think this is correct. My MKll is a SEPP configuration, no cathode follower required. 
It's been that way since the LD II++ was replaced by the MKll as far as I know.

Thus tube matching is important, both for power and driver tubes.

Please correct me if I am off base here.


----------



## TrollDragon

capetownwatches said:


> I don't think this is correct. My MKll is a SEPP configuration, no cathode follower required.
> It's been that way since the LD II++ was replaced by the MKll as far as I know.
> 
> Thus tube matching is important, both for power and driver tubes.
> ...


There is still only one driver and one output per channel, I really don't know why you would want matched tubes. Power output tubes are usually in pairs and are matched so that each tube shares the output power equally. Since the Little Dot has no power tubes and they are not in pairs, there is no benefit for using matched tubes.


----------



## MIKELAP

gibosi said:


> I hear you...  I haven't listened to my LD1+ since the Glenn OTL arrived on the scene...  about three years ago...
> 
> And as I was shoveling about 6 inches of snow today, for some reason, it popped into my head that maybe I should sell the LD1+, including all the tubes, several hundred I would guess, and adapters, as a package deal... Again, I have just begun to think about it... Haven't made a decision yet....


I sold my Littledot MK3 about a year ago and i also have plenty of tubes that i tried selling and nobody wants them . I guess there's no more adventurous rollers out there


----------



## MIKELAP

gibosi said:


> Between the LD and the OTL, I have well over 1000 tubes. lol


Your in deep my friend . That rabbit hole is endless


----------



## Scutey

Think I'm going to have the same problem as I have amassed a pile of tubes and would like to sell all in one go.


----------



## i luvmusic 2

It's difficult to sell the amp and all the tubes aii at once that is my goal but so far no luck so i'am holding on to them  until someone want the whole lot(wish me luck).I made an adapter for the LD's tubes to be used in my DIY amp and most of these tubes they do sucks in my DIY amp or maybe my DIY amp sucks....


----------



## i luvmusic 2

That rabbit hole is endless [/QUOTE]

That is true,Have you seen the Parts Conn3X10n 6080 tube sale $2.49 ea if you buy ten tubes?I bought 50 tubes i have a plan on making a speaker amp with these 6080 tube.


----------



## gibosi

MIKELAP said:


> I sold my Littledot MK3 about a year ago and i also have plenty of tubes that i tried selling and nobody wants them . I guess there's no more adventurous rollers out there



Again, I have several hundred tubes that will work in the LD, but not in my OTL. So my thinking is that whoever buys the tubes gets the amp for free. After all, given how inexpensive a new LD1+ is, I wouldn't get enough for a used, battle-worn LD+1 to be worth the trouble. And besides it still leaves me with the problem of what to do with all these tubes. They are useless without the amp. So if no one is interested in a package deal, I will just put everything in a box and store it away. And maybe after I pass, one of my heirs will be happy to have it. lol


----------



## capetownwatches

TrollDragon said:


> There is still only one driver and one output per channel, I really don't know why you would want matched tubes. Power output tubes are usually in pairs and are matched so that each tube shares the output power equally. Since the Little Dot has no power tubes and they are not in pairs, there is no benefit for using matched tubes.



Forgive me but I don't understand what you mean by saying my LD MKll does NOT have power tubes..? I may be missing something but what are those two 6N6P sticking out of it if not power tubes..? 

I'm obviously misunderstanding something rather fundamental here. I'd be most grateful for some clarity since it would be useful not to have to worry about matched tubes going forward.


----------



## OctavianH

I received a very good offer for an MK3, but I do not really think I will see a big difference from my actual MK2. Still, for that price I am thinking about it...
My logical step would be Elise sometime in the future, but I ask for an advice: should I step to MK3 in the meantime if the price is very good? Or just keep my MK2 and wait patiently for Elise?


----------



## MIKELAP

OctavianH said:


> I received a very good offer for an MK3, but I do not really think I will see a big difference from my actual MK2. Still, for that price I am thinking about it...
> My logical step would be Elise sometime in the future, but I ask for an advice: should I step to MK3 in the meantime if the price is very good? Or just keep my MK2 and wait patiently for Elise?


Elise did go up in price alot recently .I would wait and save up youll get there faster if its Elise you really want .What gets me is when Elise was launched a few years ago price was $500.USD now well i guess you saw the price still worth it ?


----------



## OctavianH

I was thinking exactly at the same thing regarding ELISE. How much is marketing compared to a real improvement. I have no timeline for ELISE so I can wait and see what is happening. But I do not expect a decrease in price since it received a lot of good reviews and people seem to buy it. And the rest of the Littledot line-up seems to be very close in sound and quality with my upgraded MK2... I guess the best decision is to stick with it and use it as long as I can.


----------



## mordy

OctavianH said:


> I received a very good offer for an MK3, but I do not really think I will see a big difference from my actual MK2. Still, for that price I am thinking about it...
> My logical step would be Elise sometime in the future, but I ask for an advice: should I step to MK3 in the meantime if the price is very good? Or just keep my MK2 and wait patiently for Elise?


Hi OH,
I have both the LD MKIII and the Elise. The Elise is a really significant upgrade. Once I got it I stopped using the MKIII.
If you want to get the Elise my suggestion is to get a good used one which should be much cheaper than a new one, considering the sizable price increase.


----------



## OctavianH

I doubt there are too many offers of used Elise amps, and if I decide to buy one I have to start again collecting tubes. My old "repository" from the Littledots will not be usable anymore.
I guess my existing collection can be used on Espressivo but that one will only be a half-upgrade.
So hard choice.


----------



## capetownwatches

So it's time for me to get a few new 6N6P for my LD MKll, and I've found a local stash of NOS (about 50 of them). 

Seller is offering them to me at $8 each, and $15 each if he matches and balances them.

They are Novosibirsk dated 1963 - lovely!

Question is though, is it worth paying double for matched tubes? Many around here seem to think it is not necessary.

Opinions??


----------



## TrollDragon

capetownwatches said:


> So it's time for me to get a few new 6N6P for my LD MKll, and I've found a local stash of NOS (about 50 of them).
> 
> Seller is offering them to me at $8 each, and $15 each if he matches and balances them.
> 
> ...


Since many here actually know it is not necessary... You should get the matched ones just for your piece of mind.


----------



## capetownwatches (Feb 1, 2018)

TrollDragon said:


> Since many here actually know it is not necessary... You should get the matched ones just for your piece of mind.



Thanks. I respect your opinion and appreciate your feedback and experience.

We are not talking money here, the tubes are cheap.
Therefore I will grab a pair of matched/balanced and two random pairs and simply compare them.

I am certain I won't hear any difference at all and I'll have enough tubes for the rest of my life!

As a newcomer to Little Dot products in particular and tubes in general, please can I ask you to explain what you meant by "Since the Little Dot has no power tubes and they are not in pairs, there is no benefit for using matched tubes."?

It's bugging me...!


----------



## TrollDragon

capetownwatches said:


> Thanks. I respect your opinion and appreciate your feedback and experience.
> 
> We are not talking money here, the tubes are cheap.
> Therefore I will grab a pair of matched/balanced and two random pairs and simply compare them.
> ...


To me, power tubes are usually in multiples and drive full size speakers. Since the LD amplifier is a preamp, (the line out and headphone jack are connected together) it has no "power tubes".  It does have preamp output tubes that are not in pairs, don't require any matched biasing and don't drive speakers.

A lot of people here call them power tubes, sort of like calling a motorized bicycle a motorcycle.


----------



## KeithEmo

Most tube amps that put out more than a few watts operate in some form of push-pull mode; each channel uses a PAIR of output tubes. In those amplifiers, in order to get the least amount of distortion, the two tubes in the pair should be as closely matched as possible in terms of gain and other electrical characteristics. Therefore, while such amplifiers will work with unmatched tubes, they generally perform better with matched ones. (Since you have two channels, each with two tubes, you want a matched set of four tubes. Note that some designs are also affected by this much more than others.) However, that sort of design is limited almost entirely to power amplifiers, like the sort intended to run speakers. Headphones require much less power, and so headphone amps almost never operate that way. Headphone amps usually use one output tube per channel, or even a single dual tube, with one section powering each channel. (I'm pretty sure that's how the Little Dot is arranged.)

If your headphone amp uses a separate output tube for each channel, then you would still want those to be matched, so both channels perform the same. If your headphone amp uses the same output tube for both channels (it's a dual tube, and one half is used for each channel), then you don't have to worry about matching two separate tubes either. However, it is still possible for two sections in the same tube to be mismatched, but it's less likely that they'll be badly mismatched than with two separate tubes.

Also note that, in amplifier terms, a headphone amplifier like the Little Dot doesn't put out much power, so its output tubes are not generally considered to be "power tubes". 



capetownwatches said:


> Thanks. I respect your opinion and appreciate your feedback and experience.
> 
> We are not talking money here, the tubes are cheap.
> Therefore I will grab a pair of matched/balanced and two random pairs and simply compare them.
> ...


----------



## Scutey

mordy said:


> Hi OH,
> I have both the LD MKIII and the Elise. The Elise is a really significant upgrade. Once I got it I stopped using the MKIII.
> If you want to get the Elise my suggestion is to get a good used one which should be much cheaper than a new one, considering the sizable price increase.





OctavianH said:


> I doubt there are too many offers of used Elise amps, and if I decide to buy one I have to start again collecting tubes. My old "repository" from the Littledots will not be usable anymore.
> I guess my existing collection can be used on Espressivo but that one will only be a half-upgrade.
> So hard choice.


Hi OH,

I can echo mordy on this, it is a major step up in audio quality, I had been looking for a second hand example for months and then, finally  a few months ago,one came up for auction, a one year old mint example, and managed to win the auction for a bit less than half the price of a new one, I have to say I love it, don't regret it for a second, and since I got it I've not touched my mkIII.  fortunately I had a few tubes that I had been using in the LD mkIII, that could be used in the Elise (6sn7 and C3g, via adapter of course,) so I didn't have to tube roll right away.

I take your point about the tubes being redundant, I sold my mkIII last week, with about a third of the tubes I had amassed, and although I did get a good price there is going to be some loss financially, the other two third of my tubes I'll try and sell a few at a time, and recoup some of the loss, unfortunately I think it comes with moving to a different tube amp. One thing though I shall remember the mkIII with fondness as it was my first tube amp.

All I can say OH, although they don't come up second hand very often they do sometimes, just keep looking, bide your time and you will get the chance to get one like I did.


----------



## OctavianH

Thank you all for your advice, all your opinions are somehow similar, that a real upgrade to Little Dot would be an Elise or Euforia (this one I do not really think I will afford in the near future). The MK3 or even MK4 are no match for it and the idea to keep the current "tube" collection is not feasible, since even this might be a drawback of the Little Dot family.
I know the title and focus of this thread, and I do not want to continue discussing other models here, where our purpose is to talk about LD tube rolling, but I will ask only 2 last questions about Elise, since I found someone who owned both LD and FA models.
1) How are the Elise stock tubes? They are decent and usable? Because the MK2 stock ones were pure garbage according to my taste and expectations.
2) I already own 2 C3G (Siemens) and 2 6SN7WGTA Jan Philips '86. Can I use these ones on Elise (of course changing current adapters)? (I guess both as drivers according to the manual, so for power tubes I will have to buy some 6N13S or keep stock ones).
I own also some 6H8C from 70s but they did not sound as expected on LD, I have not idea if these ones are usable on Elise or other amps and sound better.


----------



## capetownwatches

KeithEmo said:


> Most tube amps that put out more than a few watts operate in some form of push-pull mode; each channel uses a PAIR of output tubes. In those amplifiers, in order to get the least amount of distortion, the two tubes in the pair should be as closely matched as possible in terms of gain and other electrical characteristics. Therefore, while such amplifiers will work with unmatched tubes, they generally perform better with matched ones. (Since you have two channels, each with two tubes, you want a matched set of four tubes. Note that some designs are also affected by this much more than others.) However, that sort of design is limited almost entirely to power amplifiers, like the sort intended to run speakers. Headphones require much less power, and so headphone amps almost never operate that way. Headphone amps usually use one output tube per channel, or even a single dual tube, with one section powering each channel. (I'm pretty sure that's how the Little Dot is arranged.)
> 
> If your headphone amp uses a separate output tube for each channel, then you would still want those to be matched, so both channels perform the same. If your headphone amp uses the same output tube for both channels (it's a dual tube, and one half is used for each channel), then you don't have to worry about matching two separate tubes either. However, it is still possible for two sections in the same tube to be mismatched, but it's less likely that they'll be badly mismatched than with two separate tubes.
> 
> Also note that, in amplifier terms, a headphone amplifier like the Little Dot doesn't put out much power, so its output tubes are not generally considered to be "power tubes".



Many thanks Keith, very informative.

Especially this:  "_If your headphone amp uses a separate output tube for each channel, then you would still want those to be matched, so both channels perform the same_."

This makes logical sense, but there seem to be many here that would disagree regarding the need for tube matching when it comes to the MKll and MKlll. 

I look forward to being able to test whether I can hear a difference or not. It really seems to boil down to peace of mind of knowing that the tubes one is using are in fact operating at optimum because they match.


----------



## gibosi (Feb 2, 2018)

I very much doubt that most eBay vendors have the skill or the equipment to "match" these tubes. "Matched" power tubes are electrically identical in every way. That is, it is necessary to take a large number of different measurements. But it is very likely that these eBay vendors take only one measurement and if the tubes measure within a certain percentage, they are called "matched". But not really....

Output tubes in the LD or preamp do not have to be electrically identical. But this doesn't mean that you shouldn't do any screening. Of course, both output tubes should have been manufactured in the same factory at about the same time. And to the naked eye, their construction should appear to be identical. And of course, one NOS output tube and one at the end of its useful life wouldn't be good. But since most LD tubes are NOS, this isn't usually a problem.

So I would submit that selecting two NOS tubes manufactured in the same factory at about the same time is all that is necessary in the LD. And paying extra for so-called "matched" tubes is a waste of money....


----------



## capetownwatches

gibosi said:


> I very much doubt that most eBay vendors have the skill or the equipment to "match" these tubes. "Matched" power tubes are electrically identical in every way. That is, it is necessary to take a large number of different measurements. But it is very likely that these eBay vendors take only one measurement and if the tubes measure within a certain percentage, they are called "matched". But not really....
> 
> Output tubes in the LD or preamp do not have to be electrically identical. But this doesn't mean that you shouldn't do any screening. Of course, both output tubes should have been manufactured in the same factory at about the same time. And to the naked eye, their construction should appear to be identical. And of course, one NOS output tube and one at the end of its useful life wouldn't be good. But since most LD tubes are NOS, this isn't usually a problem.
> 
> So I would submit that selecting two NOS tubes manufactured in the same factory at about the same time is all that is necessary in the LD. And paying extra for so-called "matched" tubes is a waste of money....



Duly noted. 

I would opine that the most significant electrical characteristic when it comes to output tubes for a MKll would thus be gain. 
And if the tubes are made in the same factory at the same time, there ought to be little to no variance in this parameter.

Therefore, as you submit, there is no need for any further matching apart from factory and date.

That's what I love about these forums - always learning something new!


----------



## DRKreiger

Just got my LD MK2. I have had a 6J1 Preamp i built before, and love the Russian variant of tube for it. have like 10 i got for 7.99 way back when. Now i am interested in swapping out the 6n6 tubes for the 6h30-pi. I have rev. 3.0 PCB in the amp. Will i need to do any modding for these tubes?

TIA


----------



## capetownwatches

DRKreiger said:


> Just got my LD MK2. I have had a 6J1 Preamp i built before, and love the Russian variant of tube for it. have like 10 i got for 7.99 way back when. Now i am interested in swapping out the 6n6 tubes for the 6h30-pi. I have rev. 3.0 PCB in the amp. Will i need to do any modding for these tubes?
> 
> TIA



No you will not - they are drop in replacements for 6N6, as per LD MKll manual: 

_If your circuit version is 2.0 or above, you can also use the 6H30 type power tubes (6H30EB, 6H30PI, 6H30P-DR, etc)._


----------



## Whelkie D

capetownwatches said:


> No you will not - they are drop in replacements for 6N6, as per LD MKll manual:
> 
> _If your circuit version is 2.0 or above, you can also use the 6H30 type power tubes (6H30EB, 6H30PI, 6H30P-DR, etc)._


How can I tell what circuit version I have in my MK2?


----------



## KeithEmo

Absolutely......

Tubes made by the same company, at the same factory, and at about the same time are likely to be similar in characteristics - but there's no guarantee of that.
And, yes, some particular tube numbers or manufacturers tend to be more consistent than others as well.
And some may be more prone to having their parameters change more significantly as they age.
Likewise, some manufacturers do a better job of ensuring that the two halves of a dual tube are actually the same.

As someone noted, there are also different degrees of matching, and many sellers only match the gain or some other parameter at one point.

A lot also depends on the circuit itself...
Some circuits use feedback to control the gain, while others let the tube "run more or less wide open".
The former will be relatively immune to tube differences, while the latter will be very sensitive to them.
(Most circuits are somewhere in-between.)

In a circuit where the gain is controlled by the tube, as long as the channels sound about equal in level, then "they're matched well enough".
In a circuit with lots of feedback, if one tube has a lot more gain than the other, then it may have lower distortion (it has to do with how feedback works).
However, again, if the two channels _SOUND_ the same, then I guess the matching between them is "good enough" 



capetownwatches said:


> Duly noted.
> 
> I would opine that the most significant electrical characteristic when it comes to output tubes for a MKll would thus be gain.
> And if the tubes are made in the same factory at the same time, there ought to be little to no variance in this parameter.
> ...


----------



## capetownwatches

Whelkie D said:


> How can I tell what circuit version I have in my MK2?



You'll need to remove the base plate of the amp, as you would do if wanting to access the gain switches.

 The version is printed on the edge of the PCB.


----------



## DRKreiger

Thanks for the reply.  I had to ask because the manual was not in line with how the amp shipped.  All dip switches were set to lowest gain and the tube family jumper was set to ef92. That is another point.  The manual days no jumper for ef95. But labeled ef95 for one pair of pins. But manuals says "no jumper" for ef95. Wierd.

Side note. The main roll of my mk2 is a preamp for my 7868 tube power amp. Is there any change in the circuit for Rca out or headphones?


----------



## capetownwatches

DRKreiger said:


> Thanks for the reply.  I had to ask because the manual was not in line with how the amp shipped.  All dip switches were set to lowest gain and the tube family jumper was set to ef92. That is another point.  The manual days no jumper for ef95. But labeled ef95 for one pair of pins. But manuals says "no jumper" for ef95. Wierd.
> 
> Side note. The main roll of my mk2 is a preamp for my 7868 tube power amp. Is there any change in the circuit for Rca out or headphones?



No, no change. Preamp outs are permanently functional, as is the headphone jack. Both are affected by the gain set.


----------



## mordy

capetownwatches said:


> Thanks. I respect your opinion and appreciate your feedback and experience.
> 
> We are not talking money here, the tubes are cheap.
> Therefore I will grab a pair of matched/balanced and two random pairs and simply compare them.
> ...


Hi cape town watches,
Don’t bother with matched tubes.
In addition, a quick eBay check shows 6N6P


OctavianH said:


> Thank you all for your advice, all your opinions are somehow similar, that a real upgrade to Little Dot would be an Elise or Euforia (this one I do not really think I will afford in the near future). The MK3 or even MK4 are no match for it and the idea to keep the current "tube" collection is not feasible, since even this might be a drawback of the Little Dot family.
> I know the title and focus of this thread, and I do not want to continue discussing other models here, where our purpose is to talk about LD tube rolling, but I will ask only 2 last questions about Elise, since I found someone who owned both LD and FA models.
> 1) How are the Elise stock tubes? They are decent and usable? Because the MK2 stock ones were pure garbage according to my taste and expectations.
> 2) I already own 2 C3G (Siemens) and 2 6SN7WGTA Jan Philips '86. Can I use these ones on Elise (of course changing current adapters)? (I guess both as drivers according to the manual, so for power tubes I will have to buy some 6N13S or keep stock ones).
> I own also some 6H8C from 70s but they did not sound as expected on LD, I have not idea if these ones are usable on Elise or other amps and sound better.





OctavianH said:


> Thank you all for your advice, all your opinions are somehow similar, that a real upgrade to Little Dot would be an Elise or Euforia (this one I do not really think I will afford in the near future). The MK3 or even MK4 are no match for it and the idea to keep the current "tube" collection is not feasible, since even this might be a drawback of the Little Dot family.
> I know the title and focus of this thread, and I do not want to continue discussing other models here, where our purpose is to talk about LD tube rolling, but I will ask only 2 last questions about Elise, since I found someone who owned both LD and FA models.
> 1) How are the Elise stock tubes? They are decent and usable? Because the MK2 stock ones were pure garbage according to my taste and expectations.
> 2) I already own 2 C3G (Siemens) and 2 6SN7WGTA Jan Philips '86. Can I use these ones on Elise (of course changing current adapters)? (I guess both as drivers according to the manual, so for power tubes I will have to buy some 6N13S or keep stock ones).
> I own also some 6H8C from 70s but they did not sound as expected on LD, I have not idea if these ones are usable on Elise or other amps and sound better.


Hi OH,

It is very important to know that since most vacuum tubes are not being made any more, a manufacturer is limited to a reliable supply of either current production tubes, or out of production tubes that still exist in large quantities. These factors dictate the choice of tubes offered,
The factory supplied driver tubes for the Elise have changed over time, but the power tubes have remained the same. The tubes supplied are a good combination to start with.
There are better options, but such tubes often are harder to come by and only available in small numbers.
I think originally the Elise came with Foton tubes, then Russian Reissue Tung Sol 6SN7GTB, and now Psvane tubes (with some upgrade choices). The power tubes have remained Svetlana 6N13C.
The C3g (with adapters), the 6H8C and 6SN7 will work fine in the Elise, and the Fotons will sound better than in the LD.
By reading this thread you will get a good idea of what to choose. In addition, synergy between different combinations of driver/power tubes is very important.
Happy tube rolling!


----------



## Whelkie D

capetownwatches said:


> You'll need to remove the base plate of the amp, as you would do if wanting to access the gain switches.
> 
> The version is printed on the edge of the PCB.


Thanks for that.


----------



## Scutey

OctavianH said:


> Thank you all for your advice, all your opinions are somehow similar, that a real upgrade to Little Dot would be an Elise or Euforia (this one I do not really think I will afford in the near future). The MK3 or even MK4 are no match for it and the idea to keep the current "tube" collection is not feasible, since even this might be a drawback of the Little Dot family.
> I know the title and focus of this thread, and I do not want to continue discussing other models here, where our purpose is to talk about LD tube rolling, but I will ask only 2 last questions about Elise, since I found someone who owned both LD and FA models.
> 1) How are the Elise stock tubes? They are decent and usable? Because the MK2 stock ones were pure garbage according to my taste and expectations.
> 2) I already own 2 C3G (Siemens) and 2 6SN7WGTA Jan Philips '86. Can I use these ones on Elise (of course changing current adapters)? (I guess both as drivers according to the manual, so for power tubes I will have to buy some 6N13S or keep stock ones).
> I own also some 6H8C from 70s but they did not sound as expected on LD, I have not idea if these ones are usable on Elise or other amps and sound better.


H OH,

I won't try and add much more as mordy has already explained very well, but like you I used the Philips 6sn7 wgta and C3g in my mk III, the Elise makes better use of both, the C3g in particular sounds fantastic.


----------



## capetownwatches

mordy said:


> Hi cape town watches,
> Don’t bother with matched tubes.
> In addition, a quick eBay check shows 6N6P



Thanks Mordy! 

I'm not going to bother with matching.

Visiting the seller tomorrow and will choose a few pairs that look perfect.
They are date matched so I'm confident all will be good.


----------



## capetownwatches (Feb 4, 2018)

So I drove the 35 odd miles to go collect the tubes, and the seller let me have a closely matched pair at no additional charge.
Nice value-add, and the tubes look like they left the factory yesterday. Really mint.

We had a nice chat, he reckons he's bought numerous separate lots of 6N6P and they have all been of very high quality.
They almost all test new and with minimal variances, save for a couple here and there, and those are still eminently usable.

Mine are dated 85-05 and without further ado I rolled them into Little Dot with RCA 5654.
lets see what these 33 year old Russians can do.

Frankly I wasn't expecting the immediate and stark improvements. Like I was using new cans.

Deeper and tighter bass (which is deepening further with burn in), gone was the treble glare of the 6N6 that I only recognized in hindsight. 

There is now more heft and weight to the sound.

Smoother, creamier mids and *way* more detail in the music with DT990 Pro 250 and HD600.

Even the DT990 seems more relaxed now, I can only surmise that the 6N6P has rolled off the treble a tad?
I'm not even sure that an output tube can have that kind of effect?

I could (and will) listen to this combination for hours - I really am amazed at the difference.
Best $16 plus gas I ever spent in this hobby.


----------



## Scutey

capetownwatches said:


> So I drove the 35 odd miles to go collect the tubes, and the seller let me have a closely matched pair at no additional charge.
> Nice value-add, and the tubes look like they left the factory yesterday. Really mint.
> 
> We had a nice chat, he reckons he's bought numerous separate lots of 6N6P and they have all been of very high quality.
> ...


The 6N6P was a favourite of mine in my LD, you're also right about the treble being a bit rolled off, I found it to be warm and very punchy in the bass as you mentioned, I also feel the power tube has more influence than some believe in the overall sound.

Enjoy your 6N6P!.


----------



## JazzVinyl

I see the LD MK 6+ has a pair of fans inside to keep things cool.  Does anyone know if the LD MK9 has a fan inside?


----------



## Whelkie D

Scutey said:


> The 6N6P was a favourite of mine in my LD, you're also right about the treble being a bit rolled off, I found it to be warm and very punchy in the bass as you mentioned, I also feel the power tube has more influence than some believe in the overall sound.
> 
> Enjoy your 6N6P!.


Yes, I'd read that the power tubes  affected the overall sound by about 15%. I was shocked when I put the Russian 6N6Ps in. I found them to be much warmer. I reckon it's more like 25% - 30% of the sound character comes from the power tubes.


----------



## Scutey

Agreed, that's been my feeling for awhile, I also used to use 6n6p-ir with my LD, and the difference was instantly noticeable when changing between the two.


----------



## Whelkie D

Scutey said:


> Agreed, that's been my feeling for awhile, I also used to use 6n6p-ir with my LD, and the difference was instantly noticeable when changing between the two.


I found the "IR"s had a bit more treble. Did you notice that?


----------



## Scutey

Whelkie D said:


> I found the "IR"s had a bit more treble. Did you notice that?


Definitely, and with it a bit more detail too, maybe a touch more refined, not as much bass as the 6N6P, which is why I loved them so much, it gives them very much a fun sound imo.


----------



## capetownwatches (Feb 6, 2018)

Whelkie D said:


> Yes, I'd read that the power tubes  affected the overall sound by about 15%. I was shocked when I put the Russian 6N6Ps in. I found them to be much warmer. I reckon it's more like 25% - 30% of the sound character comes from the power tubes.



Tubes themselves don't have a "sound". It's the way the amp has been designed to work with a tube type that determines sound output (simply put, all other things being equal).

The 'sound" depends on working conditions such as currents, voltages, impedance and physical construction et al.
This determines the tubes' transfer functions - power dissipated by electrodes changes their temperatures and hence transfer functions.

What matters is how close the electrical parameters of the tube are (especially dependencies of currents on voltages) to what the rig was designed for.
There are no "bad" tubes or "good" tubes.
It all depends on how suitably built (electrical and physical characteristics) a certain tube is for a certain circuit.

Like DAC chips - implementation is a huge part of the success or failure of the design, not just the chip.

And of course then there is the subjective hearing of the listener, who prefers the interaction of a certain tube/amp combo.

I love the way the 6N6P works with my LD MKll - there is a synergy that appeals to my hearing using my cans. YMMV.

This is what makes this hobby such fun!


----------



## DRKreiger

Does anyone know of an accurate schematic for the MK2?? I almost feel like the negative feedback is shifting with the volume. Maybe i am crazy, but my other preamp didn't have odd spots with distortion. same everything other than adding the LD MK2.

Any help would be greatly appreciated.


----------



## Whelkie D

People have mentioned the 6H30 as a power tube for the MK2. How do they compare with the 6N6Ps and would I need an adaptor to try them or can they just drop straight in?


----------



## capetownwatches

Whelkie D said:


> People have mentioned the 6H30 as a power tube for the MK2. How do they compare with the 6N6Ps and would I need an adaptor to try them or can they just drop straight in?



There have been _*numerous*_ posts in this thread that will tell you all you need to know...start here:

https://www.head-fi.org/threads/lit...ube-rolling-guide.563884/page-96#post-9480971


----------



## KeithEmo

Thank you for bringing that up.... 

I always find it entertaining how much people are paying for certain tubes, and how they discuss specific variants of certain tube numbers as if they were fine vintages of wine. Back when tubes were current technology, the whole idea of tube numbers was that tubes were standardized. You went into a store and ordered "a 12AX7", and were handed whatever brand they happened to have in stock. There were a few companies offering "premium tubes", which they claimed were slightly quieter, or otherwise had some desirable characteristic, but they were treated like soda or gasoline.... you might pay an extra few cents a gallon for a bottle of soda, and you might well prefer one brand of gasoline over another, or even be quite sure that one brand "runs better in your car", but imagine if your local store started selling "premium soda" for $25 a liter....  (Bear in mind that, when they were current, a cheap signal tube, like a 12AX7, probably cost $2.... and a really premium 12AX7 might cost 50 cents more.)

The simple reality is that the only difference between different batches of tubes are slight variations in a whole slew of minor details - like electrode spacing, cathode coating, heater temperature, and even vacuum pressure - all of which are supposed to have negligible effect on the actual performance of the tube. And, yes, a slight difference in the inter-electrode capacitance of one version may cause it to sound slightly different in a certain circuit, but that difference will be RANDOM. It's not "better" or "worse" - it's just a tiny bit different. And how that difference affects it's performance will depend on the circuit you use it with.

That last point is the really important one..... 

_THE FACT THAT A CERTAIN TUBE SOUNDS A CERTAIN WAY IN A CERTAIN PIECE OF EQUIPMENT DOES *NOT* MEAN THAT IT WILL SOUND THE SAME WAY IN A DIFFERENT PIECE OF EQUIPMENT. While it is true that certain characteristics, such as an unusually low inter-electrode capacitance, may tend to make a certain tube sound "a little bright" in several different similar pieces of equipment, that isn't necessarily true. And, more to the point, it may not have the same exact effect in other different pieces of equipment. The idea that a certain tube that sounds wonderful in a certain piece of equipment will sound equally wonderful in a different piece of equipment is a fallacy. At best, with luck, it will sound the same in another of the same exact make and model.... and, even then, it may not. (The sort of differences we're talking about are about the same as the difference between routing a wire between two tubes around one side or the other... and larger and more significant differences may be present in the equipment itself. if you're going to obsess over this level of detail, then we should be discussing whether the wire connecting that driver tube to the output tube has three twists or four between them - and whether those are _right_ twists or _left_ twists.)_

And, yes, it is true that certain brands may be more consistent than others, or may share certain specific characteristics, but, again, think different brands of soda, or different brands of gasoline... and _NOT_ expensive wines.

By all means, pick and choose, and find tubes that sound just the way you like in your particular amplifier or preamp, or buy the same ones that sound great in the same model owned by your buddy, but don't fall into the trap of thinking that a particular brand or date of tube, or one with a certain color plate, or a certain shape getter, is somehow vastly superior to another - or that it justifies a huge difference in price. Knowing this also makes the hobby a lot more fun.... because it means that, if you buy a dozen cheap tubes on eBay, that nobody's ever heard of, you may just find one that sounds better in your particular amplifier than one of those uber-expensive ones that you can't afford. (And, after all, it's no fun prospecting for gold if you pay market price for it, right?)  



capetownwatches said:


> Tubes themselves don't have a "sound". It's the way the amp has been designed to work with a tube type that determines sound output (simply put, all other things being equal).
> 
> The 'sound" depends on working conditions such as currents, voltages, impedance and physical construction et al.
> This determines the tubes' transfer functions - power dissipated by electrodes changes their temperatures and hence transfer functions.
> ...


----------



## DjBobby

Getting some fast rhythmical crackling on the right channel with the LD MK2. Sounds like a wood crackling on fire, but somehow with a regular rhythm. Swapped the tubes left-right, changed both pair of tubes, went back also to the stock tubes, always the same. It happens with a volume muted to zero and it doesn't get any louder with the volume up. Any suggestions?


----------



## DRKreiger (Feb 10, 2018)

Rhythmic sounds not tied to volume or tube swapping sounds like emi. Is it near any strong digital gear? Do tour signal rcas pass near anything?


----------



## DjBobby

DRKreiger said:


> Rhythmic sounds not tied to volume or tube swapping sounds like emi. Is it near any strong digital gear? Do tour signal rcas pass near anything?


Well not exactly. This rhythmical thing comes and goes away. When it comes it's like fast ts, ts, ts, ts....sound. Like a telegraph code. The RCA cable is shielded. Also disconnected completely the RCA, nothing changes. Sometimes it is only short crackle like putting some drops of water on the candle fire. What drives me crazy is that it is not dependent on tubes. Tried all the combinations, like moving to another place and switching phone to flight modus, still crackles.


----------



## Whelkie D

DjBobby said:


> Well not exactly. This rhythmical thing comes and goes away. When it comes it's like fast ts, ts, ts, ts....sound. Like a telegraph code. The RCA cable is shielded. Also disconnected completely the RCA, nothing changes. Sometimes it is only short crackle like putting some drops of water on the candle fire. What drives me crazy is that it is not dependent on tubes. Tried all the combinations, like moving to another place and switching phone to flight modus, still crackles.


Have recently used an RF meter and found that WiFi routers in paticular have the sort of regular rhythmic frequency you seem to be describing. Is your LD near a Wifi?


----------



## DjBobby

Whelkie D said:


> Have recently used an RF meter and found that WiFi routers in paticular have the sort of regular rhythmic frequency you seem to be describing. Is your LD near a Wifi?


At least 6 meters (20 feet) and 2 walls between.


----------



## mordy

DjBobby said:


> At least 6 meters (20 feet) and 2 walls between.


Hi DjB,

It sounds like some kind of interference. There are many sources - appliances, portable phones, fluorescent lights, routers etc etc. Try to think of something that might cause it - not always easy; sometimes a portable phone is the culprit.
You can also try a Faraday cage to shield the tubes. The simplest way is to take some aluminum foil and wrap around the tubes in different positions.


----------



## mattrudy80

mordy said:


> Hi DjB,
> 
> It sounds like some kind of interference. There are many sources - appliances, portable phones, fluorescent lights, routers etc etc. Try to think of something that might cause it - not always easy; sometimes a portable phone is the culprit.
> You can also try a Faraday cage to shield the tubes. The simplest way is to take some aluminum foil and wrap around the tubes in different positions.


My cell phone makes my LDMKIVSE do exactly what you're describing when it's to close (Samsung galaxy s7).


----------



## gulakpii

This is very likely caused by RF interference on the circuit (especially the tubes).
If you cannot switch off the nearby appliances (especially routers) to test this, you may consider to bring your LD to some place else and test it again.


----------



## DjBobby

mordy said:


> Hi DjB,
> 
> It sounds like some kind of interference. There are many sources - appliances, portable phones, fluorescent lights, routers etc etc. Try to think of something that might cause it - not always easy; sometimes a portable phone is the culprit.
> You can also try a Faraday cage to shield the tubes. The simplest way is to take some aluminum foil and wrap around the tubes in different positions.





mattrudy80 said:


> My cell phone makes my LDMKIVSE do exactly what you're describing when it's to close (Samsung galaxy s7).





gulakpii said:


> This is very likely caused by RF interference on the circuit (especially the tubes).
> If you cannot switch off the nearby appliances (especially routers) to test this, you may consider to bring your LD to some place else and test it again.


Thanks a lot mordy, mattrudy80 and gulakpii fo the heads up, really appreciate your advices. I might try to move the LD into another room, the furthest one from the router and see if it still happens. What I still don't understand is that it is only on the right channel. If it is some kind interference shouldn't it affect all tubes equally?


----------



## kousik1946

DjBobby said:


> Thanks a lot mordy, mattrudy80 and gulakpii fo the heads up, really appreciate your advices. I might try to move the LD into another room, the furthest one from the router and see if it still happens. What I still don't understand is that it is only on the right channel. If it is some kind interference shouldn't it affect all tubes equally?


One more advice, if you have bad earthing in your electrical circuit this also happens. If you are connecting your dac to a laptop, which is connected via three pin connector this noise can happen. What also happened to me before. So I used a 2 pin extensension to connect my laptop and noise is gone. You can try this also.


----------



## i luvmusic 2

Woooo!Eliminating the EARTH/SAFETY GROUND it may cut the ground loop and at the same time you eliminate the grounding in your appliance earth/safety ground without these ground connection you could easily energize the chassis and if you ever touch it while it is energize you are pretty much FU@K.I'am not an Engineer so i could be wrong and it won't be the first time if iam wrong.


----------



## kousik1946

i luvmusic 2 said:


> Woooo!Eliminating the EARTH/SAFETY GROUND it may cut the ground loop and at the same time you eliminate the grounding in your appliance earth/safety ground without these ground connection you could easily energize the chassis and if you ever touch it while it is energize you are pretty much FU@K.I'am not an Engineer so i could be wrong and it won't be the first time if iam wrong.


Yes I know it is not wise. But in my case I do not have other options.


----------



## DjBobby

Thanks everybody for pointing me to the RFI cause.  I went with the LD to the basement where there is no wifi reception at all. Have waited and waited and waited...and there was no crackling at all! Pleasing silence. So it must definitely be the RFI. 
I am using LD mostly streaming Tidal through Audirvana from MacBook Pro - Chord Mojo feeding LD or streaming hi-rez files stored on the NAS to Audirvana. Both involves heavy duty wifi streaming in the room so the RFI is unavoidable. Now I have 2 options: either to make a Faraday cage and shield the tubes, or just leave it down under in the basement, which is actually a wine cellar .


----------



## mattrudy80

kousik1946 said:


> Yes I know it is not wise. But in my case I do not have other options.


I have very bad ground loop issues and also live near a major AM radio transmitter which causes the broadcast to be injected into my stereo equipment. I found a HumX made by EBTECH at a local guitar dealer and it fixed 99% of my issues (nice to find local for returns if it doesn't work). They're a bit spendy at $80, but considering the investment I have in all of my audio equipment it was peanuts. I found mine at Guitar Center. They are also sold on Amazon: https://www.amazon.com/Ebtech-Hum-G...pID=513iD2nS3hL&preST=_SY300_QL70_&dpSrc=srch


----------



## i luvmusic 2

I have these,I haven't find a time to work on it I plug-in my MK III to these and it's quiet i don't hear the slight HUM that i hear when i turned the volume pot all the way up.


----------



## steph280

Sorry if this sounds like noob question, but is there a way to use the Little Dot II as a phono pre-amp?


----------



## capetownwatches

steph280 said:


> Sorry if this sounds like noob question, but is there a way to use the Little Dot II as a phono pre-amp?



No.


----------



## Whelkie D (Feb 22, 2018)

steph280 said:


> Sorry if this sounds like noob question, but is there a way to use the Little Dot II as a phono pre-amp?


 Not as a phono pre-amp, no.


----------



## steph280

Thanks.


----------



## tim273

This might also be good for noise, I haven't tried it yet but looks promising: https://www.arraysolutions.com/ac-7b


----------



## Johnybuchar (Mar 8, 2018)

Hello everyone,
I have  LittleDot3 + Shure940. Drive tubes - Tesla 6F32, Voskhod 6sh1p-ev, Yugoslavia 6AK5.

Recently i have changed an original russian power 6h6p for 6h6p NOS with gold grids (1970s) on my LT3. I am suprised that overall sound is "brighter" with thin bass. I assumed an improvement but the original tubes sound better with more "drift" for my ears . Does anybody have similar experience? Do you recommend to try tubes 6h6p-i? Thank you for an advice.

Ebay auction:
https://www.ebay.com/itm/182879364513


----------



## mordy

Hi JB,
As with all new tubes, they require a break in period, usually in the range of 30-50 hours (although some tubes take make longer to come to full potential).
First see if they improve over time.
The IR tubes sound better than the regular ones and are not too expensive;
https://www.ebay.com/itm/Lot-of-4-p...hash=item1edb1b6775:m:mRLUi3yYPe7Vw1tV0J9INXA
Then there is 6H30 DR which are very expensive in the range of $400-500/pair (I never tried them) that are supposed to be the best of this type but probably not worth the price in terms of improvement.
However, my suggestion is to go a different route: Buy a pair of 6SN7 octal tubes (cheapest works just fine) and a pair of adapters for use in the LD MKIII. It is just plug and play, and this combination with the Ei 6HM5 Yugoslavian tubes is pretty much the best sound you can get from the LD MKIII.
If you look on the Little Dot blogs you will find a wealth of information.


----------



## Johnybuchar (Mar 9, 2018)

Hi Mordy,

Firstly thank you very much for detail answer. I have seen the adapters for 6SN7 but I didn't have a trust with them . I have a tube integrated amplifier Yaqin with cathode followers 6N8S(6SN7) NOS Photon . But I know that many tube beginners make a tube rolling without a knowledge and don't care about specific parameters of tubes which can damage an amplifier (e.g. overload transformers). I will read the forum with LT3/6SN7 through. Thank you for tip.


----------



## gulakpii

I have both the 6SN7 and 6N6P-ir tubes, and honestly I like the 6SN7 sound better.
However, the 6sn7 works only with my >300 ohm headphones.  
I heard distorted sound using the 6SN7 with my low-Z cans (AKG 712, 701).  As your Shure's impedance is about 40 ohm , I suggest you stay with the 6H30 or 6N6P, which I have no problem with low-Z cans.
Of course, YMMV!


----------



## Johnybuchar

I was very satisfied with a combination AKG702+LT3 but I had to change them for a closed headphones. I have just put tubes GE 5star 5654 into my LT. First expression is the same as on the opening page of thread (clear, airy, wide soundstage). A tasting is going to begin because I bought JAN GE 5654W, RAYTHEON JAN5654 too .


----------



## sghound

i dun seem to be able to register on http://www.littledot.net/forum/index.php

nor is there a link to the board admin's contact.

can anyone help by providing email contacts please?

much appreciated.


----------



## TrollDragon

sghound said:


> i dun seem to be able to register on http://www.littledot.net/forum/index.php
> 
> nor is there a link to the board admin's contact.
> 
> ...


Their forum has it's new member registration option disabled and the admin contact is disabled as well. 

You can contact the creator on eBay:
https://www.ebay.com/usr/davidzhezhe

Or through the listed gmail address:
little.tube@gmail.com

I have no idea if anything sent to those places will be answered, if it's a "will tube XXX or headphone XXX work" question, then I doubt you will even get a reply.


----------



## Johnybuchar

Testing of RAYTHEON JAN5654 ...  a vigorous, engaging sound maybe no clear like Tesla 6F32 but it doesn't matter .


----------



## bobbyblack

Tf is this?:https://m.ebay.com/itm/Little-Dot-M...881858?hash=item3f76038542:g:0A4AAOSwx6pYqrRc


----------



## mordy

bobbyblack said:


> Tf is this?:https://m.ebay.com/itm/Little-Dot-M...881858?hash=item3f76038542:g:0A4AAOSwx6pYqrRc


Don't know what this is, but looks like a hybrid tube/transistor balanced amp. If you decide to buy, this seller will save you $140.00:
https://www.ebay.com/itm/Little-Dot...m=112845291311&_trksid=p2047675.c100005.m1851


----------



## bobbyblack

Pleasure to see you again mordy,helpfull like always,thanks.No, actually i was just browsing ebay for tube amps and saw this amp that i  never heard of.
I'm set on the La Figaro 339 and waiting to drop again on Massdrop.

Cheers!


----------



## mordy

bobbyblack said:


> Pleasure to see you again mordy,helpfull like always,thanks.No, actually i was just browsing ebay for tube amps and saw this amp that i  never heard of.
> I'm set on the La Figaro 339 and waiting to drop again on Massdrop.
> Hi bb,
> 
> ...


----------



## Ggroch

TrollDragon said:


> The LD forum has it's new member registration option disabled and the admin contact is disabled as well.
> 
> You can contact the creator on eBay:
> https://www.ebay.com/usr/davidzhezhe
> ...



Apparently David is no longer at Little Dot.  When I sent an Email to the above gmail address I got bounce-back that said the new address is little_dot@vip.163.com 

When I emailed this vip.163 address I got a reply from Sword Yang (the designer) who said David Zhezhe is no longer at Little Dot and that their eBay store is closed.  You can buy directly from Sword using the above address using Paypal. 

The reply I god seems genuine, but I have not confirmed any of this (ie, I did not purchase anything), so be cautious, but I can confirm that when I emailed the old official g-mail address that you get a reply to use the vip.163 address which is apparently Sword Yang.


----------



## bobbyblack

Ggroch said:


> Apparently David is no longer at Little Dot.  When I sent an Email to the above gmail address I got bounce-back that said the new address is little_dot@vip.163.com
> 
> When I emailed this vip.163 address I got a reply from Sword Yang (the designer) who said David Zhezhe is no longer at Little Dot and that their eBay store is closed.  You can buy directly from Sword using the above address using Paypal.
> 
> The reply I god seems genuine, but I have not confirmed any of this (ie, I did not purchase anything), so be cautious, but I can confirm that when I emailed the old official g-mail address that you get a reply to use the vip.163 address which is apparently Sword Yang.


A little risky to order on that email,much safer on ebay but if they do not sell anymore there...i ordered my LD MK3(3 years ago)from David.


----------



## mordy (Mar 24, 2018)

bobbyblack said:


> A little risky to order on that email,much safer on ebay but if they do not sell anymore there...i ordered my LD MK3(3 years ago)from David.


Hi bb,

Just as a point of information, Massdrop just announced the Little Dot MKIII SE (and the MKIII) for $230.00 including US shipping.
https://www.massdrop.com/buy/littledot-tube-amp?
utm_placement=0&referer=YMFN92&mode=guest_open&utm_campaign=Automated%20Daily%20Promotional%202018-03-24&utm_source=SparkPost&utm_medium=email&utm_term=Daily%20Promotional&utm_content=1521872549532.610746630529346084923340
I do not know anything about the SE model and have not found any reviews on this two-tube hybrid balanced amp.
I did order earbuds and a Sennheiser HD650 in the past from Massdrop and would not consider Massdrop a gamble.


----------



## Ggroch

mordy said:


> Hi bb,
> 
> Just as a point of information, Massdrop just announced the Little Dot MKIII SE (and the MKIII) for $230.00 including US shipping.



This drop is confusing, but the MKIII is $230 and the MKIII SE (the balenced one) is $460.


----------



## mordy

Ggroch said:


> This drop is confusing, but the MKIII is $230 and the MKIII SE (the balenced one) is $460.


Hi Gg,

Thanks for the correction - I thought that the price sounded strange, but when I looked I could not find the higher price listing that you found for the SE.
It seems that Little Dot has undergone changes in ownership, and David Zhe Zhe has left the company, which now seems run by the amp designer Sword Yang.


----------



## bobbyblack

Yea so it seems that LD MK3SE it is double the price of MK3, nevertheless a very interesting option for whom want balanced out but with ss output stage idk if you get that full tube sound.


----------



## sghound

Little Dot 2 question:

can anyone explain the difference between ver3 and ver2 board of this amp? thx!


----------



## frogmeat69

I bought my Mkiii from Massdrop, plus many other things. Never had a problem with any orders, but I don't think you get a warranty on those Little Dot amps when purchased through Massdrop, just a heads up in case you're thinking of joining the drop.


----------



## gulakpii

I have my LD Mk4 for 4 years now and it never developed a problem.  It is rather rugged even I rolled dozens of tubes on it with wiring mod's. ( I change tubes every other day for fun)
Just that the industrial design was not to my best liking.  May be its just a personal taste problem.


----------



## matthew23

Hi all, I have a quick question. Total tube newb here (and I am sorry if this is answered somewhere in the 765 pages that preceded it!).   

I bought a Little Dot MKII headphone amp to use with my Sennheiser 6XX that I plan to hook up to my Outlaw 2160 stereo receiver. However, I was reading that i can also use the Little Dot as a preamp and experiment with tube rolling and sound out of my speakers as well. But, I am unclear how to do this. The Dot has left and right inputs and outputs on the back. Here is a link to the back of the 2160 receiver: https://www.outlawaudio.com/images/RR2160RP.jpg

Can someone explain to a newb how I hook up the Little Dot as a headphone amp and as a preamp to use with the speakers?  Which inputs/outputs do I connect on my receiver?

Also, I just purchased a Voskhod 6J1P-EV / 6ZH1P-EV, Matched Pair from Ebay.  It is my understanding that these are the signal tubes?  Do I need power tubes as well?  Or will these work with the stock ones in the LD?

Thank you so much!!


----------



## Ggroch

matthew23 said:


> ......I bought a Little Dot MKII headphone amp to use with my Sennheiser 6XX that I plan to hook up to my Outlaw 2160 stereo receiver.
> 
> Can someone explain to a newb how I hook up the Little Dot as a headphone amp and as a preamp to use with the speakers?  Which inputs/outputs do I connect on my receiver?



You have several ways you could hook it up.

If you want to listen to the Little Dot as a pre-amp (really a "tube buffer because you are still controlling, switching through the Outlaw) your receiver can do this very well using the "External Processor" Out and In.   The user guide says the Processor Out remains at full level independent of the Outlaws volume control.  Perfect.  Hook the Outlaw Processor OUT to the LD Input, and the LD output to the Processor IN.   Your Outlaw will work as normal on your speakers, but when you want to hear the effect of your tube buffer on the speakers, you just hit the "External Loop" button on the Outlaw.  Keep the volume on the  LD low when you start to try this until you figure out where it should be to just match the volume of the system when the loop is not being used.

If you decide just to use your Outlaw to send sources to The Little Dot, a different, simple safe way to do it is to hook the Input on the Little Dot to the "REC OUT" on the back of the Outlaw.  This is nice because it does not change anything in the way you use the system now.  The volume control/bass/treble etc of the Outlaw will not effect the Little Dot.... You control the Little Dot just as normal as well.   You do NOT have the option of listening to the tube pre-amp through your speakers this way.



matthew23 said:


> Also, I just purchased a Voskhod 6J1P-EV / 6ZH1P-EV, Matched Pair from Ebay.  It is my understanding that these are the signal tubes?  Do I need power tubes as well?  Or will these work with the stock ones in the LD?


Others are a lot more experience than I am on this question, but I understand that there are not many choices for changing the power tubes...most people just change the signal tubes and the ones you got should work great with the stock ones.


----------



## Whelkie D

matthew23 said:


> Hi all, I have a quick question. Total tube newb here (and I am sorry if this is answered somewhere in the 765 pages that preceded it!).
> 
> I bought a Little Dot MKII headphone amp to use with my Sennheiser 6XX that I plan to hook up to my Outlaw 2160 stereo receiver. However, I was reading that i can also use the Little Dot as a preamp and experiment with tube rolling and sound out of my speakers as well. But, I am unclear how to do this. The Dot has left and right inputs and outputs on the back. Here is a link to the back of the 2160 receiver: https://www.outlawaudio.com/images/RR2160RP.jpg
> 
> ...



I am using  my Little Dot  MK2 as a pre amp by running the source (CD player etc) through the inputs in the little dot them running the outputs from that into the "main in" section on my NAD amp. This is effectively using the NAD to power my speakers and the LD as a preamp. Hope this helps.


----------



## matthew23

Ggroch said:


> You have several ways you could hook it up.
> 
> If you want to listen to the Little Dot as a pre-amp (really a "tube buffer because you are still controlling, switching through the Outlaw) your receiver can do this very well using the "External Processor" Out and In.   The user guide says the Processor Out remains at full level independent of the Outlaws volume control.  Perfect.  Hook the Outlaw Processor OUT to the LD Input, and the LD output to the Processor IN.   Your Outlaw will work as normal on your speakers, but when you want to hear the effect of your tube buffer on the speakers, you just hit the "External Loop" button on the Outlaw.  Keep the volume on the  LD low when you start to try this until you figure out where it should be to just match the volume of the system when the loop is not being used.
> 
> ...



Wow, thank you so much!  That makes total sense. Just a few more questions - If I use the External Processor out and in, will the Little Dot still work as a headphone amp at the same time (do I just plug my headphones into the Little Dot)?  Also, if it is hooked up to the External Processor, does the Little Dot take over all volume controls when the External Loop button is pressed?  Do I have to worry about damaging the receiver or Little Dot with overload or gain issues?


----------



## Ggroch (Mar 27, 2018)

matthew23 said:


> .....If I use the External Processor out and in, will the Little Dot still work as a headphone amp at the same time (do I just plug my headphones into the Little Dot)?  Also, if it is hooked up to the External Processor, does the Little Dot take over all volume controls when the External Loop button is pressed?  Do I have to worry about damaging the receiver or Little Dot with overload or gain issues?



1. I have an LD  III, and on it the pre-outs stay on all the time whether you have headphones plugged in or not...they do not shut off when you plug in headphones.  And the volume knob on the LD controls its Pre-outs too.  So, when you have the external loop button pressed on the Outlaw you will have 2 volume controls for your speakers, both the receivers and the LD. (the Outlaw volume control will not effect Headphones plugged into the LD), So you need to be careful when learning what levels to set when you start, and careful when you are switching between headphones and speakers...just get used to turning the volume on the LD & Outlaw down when you switch til you have it figured out.

What I am not certain of is whether the External OUT on the Outlaw has a signal all the time, even when the loop is not chosen.  I think it probably does, which is what you want. So the LD will still play your Outlaw sources for headphones even when you are not using speaker loop button.    

 .....edit, cancel my 2nd suggestion, would not work.


----------



## matthew23

This is good stuff!  Thanks for taking the time to help me out. 

Why wouldn’t the 2nd suggestion work?  Does the loop need to be completed (in/out)?


----------



## Ggroch (Mar 27, 2018)

matthew23 said:


> Why wouldn’t the 2nd suggestion work?  Does the loop need to be completed (in/out)?



No, my concern is that the Rec Out alway plays whatever source your choose....and the Outlaw user guide says that the External In can be used as an additional source, even if you do not hook up anything to the External Out...so, I think if you hooked the input of the LD to the Outlaw's Rec Out...when you choose the External Loop button, the Rec Out might play the External source...it would be playing into itself.    So try method 1 first. 

if that does not work as you expect then PM me or post again here, there are more ways to do it. The Outlaw is a very flexible receiver.


----------



## matthew23

Cool, thanks so much. It arrived today so I’ll mess with it after I put my kids to bed!


----------



## mordy

Whelkie D said:


> I am using  my Little Dot  MK2 as a pre amp by running the source (CD player etc) through the inputs in the little dot them running the outputs from that into the "main in" section on my NAD amp. This is effectively using the NAD to power my speakers and the LD as a preamp. Hope this helps.


Hi M23,
I have an Outlaw RR2150 receiver which I assume is similar to the 2160. On the back of it is a u-shaped jumper that connects the preamp section to the power amp. If you have this feature, you should be able to pull out the jumpers and just use the amp section in the 2160. This means that the tone controls won't work, and the volume is controlled by the LD if I understand correctly.
I am using my tube preamp as a tube buffer plugged into an equalizer circuit in an old Sony integrated amp. Even though the Sony has it's own preamp, this works well with good synergy, although I am not sure that all integrated amps will have the same synergy.
Personally, I enjoy being able to use the tone controls and the balance control, plus the ability to use multiple sources, all with glorious tube sound.


----------



## matthew23

So that means using the external processor approach suggested by Gg would still be the better option so I maintain control of those features, correct?


----------



## Tony51

I put these on and I swear by them, they put a tad more power and runs my cans with ease when the stock power tubes didn't.
*6H30P SOVTEK - MATCHED PAIR*
*You can them at audiophiletubes.com*


----------



## Ggroch

matthew23 said:


> So that means using the external processor approach suggested by Gg would still be the better option so I maintain control of those features, correct?



The equalizer circuit Mordy describes on his Sony is just different terminology for external processor loop, they are the same, so that is where I would start. Just keep the volume low on everything until you know how it all works. 

 You can also (as Mordy mentions) just plug the LD to your Main Power Input, the problem is that since the LD  Pre-Outs are always live...ie, do not shut off when you plug in headphones, the switching back and forth gets more complicated. 

Start with the equalizer/external processor loop plan and let us know if you have issues. .


----------



## matthew23

Ggroch said:


> The equalizer circuit Mordy describes on his Sony is just different terminology for external processor loop, they are the same, so that is where I would start. Just keep the volume low on everything until you know how it all works.
> 
> You can also (as Mordy mentions) just plug the LD to your Main Power Input, the problem is that since the LD  Pre-Outs are always live...ie, do not shut off when you plug in headphones, the switching back and forth gets more complicated.
> 
> Start with the equalizer/external processor loop plan and let us know if you have issues. .


Will do. Thanks again for looking out!


----------



## Ggroch

There is a 15% off everything over $25 code til 8PM Pacific on eBay right now.  So I am trying to choose my 2nd set of Preamp tubes for my MK III  

I already have, and very much like, a pair of GE JAN 5654W.         At the very start of the thread it was suggested Voshkod 67H1P-EVs are a great match, and Yenaudio seems a reliable vendor.  I am equally intrigued by the Mullard 8100 option, but there seem to be a lot more versions of them, or at least a lot more brands of the same thing which is confusing.    Is the Voshkod the best safe choice?   At this point I would rather not deal with socket adapters or changing the internal jumpers unless there is a strong reason.  Have to decide quick.


----------



## matthew23

So the external processor method worked!  But I do get some clipping if I try to turn the LD up too much. If I keep it at 30% or so or less, it’s fine as long as I use the receiver to turn it up higher. Is that normal?  Do you think adjusting the gain in the LD would help?


----------



## Ggroch

matthew23 said:


> So the external processor method worked!  But I do get some clipping if I try to turn the LD up too much.......



Great.  The distortion you describe when turning up the LD volume too high is normal.  When you are using the speakers (external loop button pushed) the perfect volume position on the LD is where your speakers are at the exact same volume with the LD tube buffer on (External Loop button pushed) as when it is not in the circuit (External Button Off).   Just determine where that Is on the LD control, and then leave it there all the time when you are using your speakers.  Adjust the volume for your speakers with the Outlaw Volume.

When you are using headphones only (external loop off), then adjust the LD volume however you want, it should not distort.     You did test it with headphones only (external button off) right?  that worked?


----------



## matthew23

Ggroch said:


> Great.  The distortion you describe when turning up the LD volume too high is normal.  When you are using the speakers (external loop button pushed) the perfect volume position on the LD is where your speakers are at the exact same volume with the LD tube buffer on (External Loop button pushed) as when it is not in the circuit (External Button Off).   Just determine where that Is on the LD control, and then leave it there all the time when you are using your speakers.  Adjust the volume for your speakers with the Outlaw Volume.
> 
> When you are using headphones only (external loop off), then adjust the LD volume however you want, it should not distort.     You did test it with headphones only (external button off) right?  that worked?


Perfect!  I adjusted the volume and everything works great!  I did test the headphones with the EB off and everything checks out. Thanks so much!!!  The amp thing is all new but I think I’m going to have fun trying out new tubes. The stock tubes are a bit harsh but I’ve ordered some that were recommended and can’t wait to try them. 

You said you had a LD MKiii?  How do you like that?  I’d it worth an upgrade from the mkii?  Any tubes you recommend?


----------



## mordy (Mar 27, 2018)

Ggroch said:


> Great.  The distortion you describe when turning up the LD volume too high is normal.  When you are using the speakers (external loop button pushed) the perfect volume position on the LD is where your speakers are at the exact same volume with the LD tube buffer on (External Loop button pushed) as when it is not in the circuit (External Button Off).   Just determine where that Is on the LD control, and then leave it there all the time when you are using your speakers.  Adjust the volume for your speakers with the Outlaw Volume.
> 
> When you are using headphones only (external loop off), then adjust the LD volume however you want, it should not distort.     You did test it with headphones only (external button off) right?  that worked?


Can't remember why, but the best results with speakers are supposed to be when you turn up the volume on the LD as much as you can without getting distortion. I also seem to remember that using headphones together with the speakers, lowers the volume on the headphones.
You have to watch out that you lower the volume before using headphones - could be way too loud using the same setting as for speakers.

Here is the link to the Little Dot MKIII manual:
https://www.dropbox.com/s/5f8jzzwbxhulf3a/Little Dot MK III Reference Guide.docx?dl=0
Page 9 reads:
Little Dot MK III Pre-Amplifier Use

The Little Dot MK III is not

to

be used with a DC or direct coupled power amplifie

r. Doing so may

result in damage to your Little Dot and/or downstre

am components! The Little Dot MK III should only

be used with AC / capacitor coupled power amplifier

s. If you are unsure if your power amplifier or

receiver is AC or DC coupled, please contact the ma

nufacturer

’

s support line.

The pre-amplification signal in the Little Dot MK III

includes both the driver and power tubes for better

compatibility with power amplifiers with low input im

pedance (for example, transistor-based power amps).

Always

power on your Little Dot MK III pre-amplifier befor

e you power on your connected power amplifier

as

this is good practice for any pre-power combination (i

.e. power on components from upstream to

downstream).

It is also

highly recommended

to wait at least a minute after powering on your Li

ttle Dot

before turning on your power amplifier so that the Li

ttle Dot

’

s tubes have time to stabilize.

When powering your system off,

always

switch everything off from downstream to upstream, i.e

. first turn off

your power amplifier, then your pre-amp, and finally y

our source.

For best sound quality and lowest noise, first maximize

your source

’

s output level without introducing gain

(i.e. to 0 dB), and then set your Little Dot MK III

’

s volume to a relatively high level. Amplification d

one at the

pre-amp stage will result in less noise than amplificat

ion done at the power amplifier stage (if the ampli

fier

you are using as a power amp has volume control at all

).

One last thing to remember is keep all your components

connected to the same ground, as introducing

another amplifier in a pre-power setup increases the l

ikelihood of introducing a ground loop.
_As far as I know, my Outlaw RR2150 is a DC coupled amp, and I did experience a meltdown of one channel (the amp blew up). Don't know if it was connected to the Little Dot or a blown speaker or both, but it was very unpleasant. I also don't know if the RR2160 incorporates protective circuitry, which apparently my old Sony amp has. 
Just be forewarned and careful...._
Sorry for the poor layout when I copied the manual.


----------



## Ggroch

matthew23 said:


> You said you had a LD MKiii?  How do you like that?  I’d it worth an upgrade from the mkii?  Any tubes you recommend?



i have never used an MKII, so cannot comment on the difference.  I owned a Darkvoice 336SE for a while and like the MKiii a lot better for what some may think is a strange reason.  The 336SE does not have adjustable gain switches like the MKiii has, so it has lots of gain all the time.  I could only use the first 1/4 of the volume control with half of my headphones.   The MKiii has 4 different gain adjustment settings, so I can use both high efficiency phones, and my Powered Montitors (preamp mode) and still have great volume control.     I think they both sounded great.  I did not own them at the same time, so I cannot directly compare.  I am very happy with the MKiii.

Best tubes: As my above post 11456 indicates, I have very little experience with different tubes. My 1st upgrades are GE JAN 5654W.  Chosen because they are very highly rated in the first posts on this thread, and because they are in very good supply (cheap).    I think they sound great.

I have just ordered 2 more tested pairs to try:  Voskhod 6J1P-EV , and Tung Sol JTL-6AK5 - I got them from highly rated sellers, but not Yenaudio because these sellers were cheaper.

I am pretty convinced that the quality of sound when you tube roll is not at all related to how much you paid for the tubes.  In fact, if we assume that back in the tube days radio manufacturers and other users, like the military, chose tubes because they were the best functionally, then it makes sense that many of the very best tubes were made in large quantities...and should be pretty cheap now.  So in many cases (but certainly not all) some of the more common tubes, like the GE JAN 5654W, a military tube, can be some of the best.


----------



## Ggroch (Mar 27, 2018)

mordy said:


> Can't remember why, but the best results with speakers are supposed to be when you turn up the volume on the LD as much as you can without getting distortion. I also seem to remember that using headphones together with the speakers, lowers the volume on the headphones.
> You have to watch out that you lower the volume before using headphones - could be way too loud using the same setting as for speakers.....


  Then LD Manual text


All good info Mordy...but the settings you describe are mostly valid when you are connecting the LD between the Outlaw Pre-Out, and the Outlaw Main In loop....  Not in the external loop like we are doing here.

The instructions for the Outlaw say that the External Out Loop volume is fixed, not variable.  So the volume control on the Outlaw should not effect the External Out (the LD input) at all.   The Outlaw volume, (and other pre-amp adjustments like tone controls) comes AFTER the External In (LD output).    If the manual is right, this means that if you are listening to headphones on the LD, the volume control on the Outlaw should not effect it  at all.

If the instructions are correct (easy for Mathew to test), then the Outlaw's External Processor loop works totally within the Pre-amp section of the Outlaw...and would not be direct coupled to the amp. (I am not an expert here).

All of the other precautions the user guide mentions seem like very good advice.



mordy said:


> ......One last thing to remember is keep all your components connected to the same ground, as introducing another amplifier in a pre-power setup increases the likelihood of introducing a ground loop.
> _As far as I know, my Outlaw RR2150 is a DC coupled amp, and I did experience a meltdown of one channel (the amp blew up). Don't know if it was connected to the Little Dot or a blown speaker or both, but it was very unpleasant. I also don't know if the RR2160 incorporates protective circuitry, which apparently my old Sony amp has...Just be forewarned and careful..._.



WOW!...... you might have mentioned the risk of the LD blowing up your Outlaw before I offered all of this free advice  

I am hoping and expecting that inserting the LD into the external loop bypasses most of the danger....just keep the gain of the LD buffer to Zero (same volume as out of the circuit.  This has always been the best advice when using other processors too, like graphic equalizers.  You set the EQ to the way you like it first, and then set the overall gain (master Equalizer volume) so that it is about the same when it is in and out of the circuit.


----------



## matthew23

mordy said:


> Can't remember why, but the best results with speakers are supposed to be when you turn up the volume on the LD as much as you can without getting distortion. I also seem to remember that using headphones together with the speakers, lowers the volume on the headphones.
> You have to watch out that you lower the volume before using headphones - could be way too loud using the same setting as for speakers.
> 
> Here is the link to the Little Dot MKIII manual:
> ...


That is really scary. We’re you able to get it fixed?


----------



## matthew23

Ggroch said:


> i have never used an MKII, so cannot comment on the difference.  I owned a Darkvoice 336SE for a while and like the MKiii a lot better for what some may think is a strange reason.  The 336SE does not have adjustable gain switches like the MKiii has, so it has lots of gain all the time.  I could only use the first 1/4 of the volume control with half of my headphones.   The MKiii has 4 different gain adjustment settings, so I can use both high efficiency phones, and my Powered Montitors (preamp mode) and still have great volume control.     I think they both sounded great.  I did not own them at the same time, so I cannot directly compare.  I am very happy with the MKiii.
> 
> Best tubes: As my above post 11456 indicates, I have very little experience with different tubes. My 1st upgrades are GE JAN 5654W.  Chosen because they are very highly rated in the first posts on this thread, and because they are in very good supply (cheap).    I think they sound great.
> 
> ...


I just ordered the Voskhod 6J1P-EV earlier today after reading how bad the stock tubes are. Looking forward to trying them out. Good info on the military tubes as well, what you say makes a lot of sense. Maybe I’ll try the 5654W’s next...they can be found very cheap on eBay. Can you PM me the links to the seller?


----------



## Ggroch (Mar 27, 2018)

The GE JAN tubes I got were like these from oletronix.   They were very cheap, matched, arrived looking new (very well packed), and sound great.   Only thing I have ever purchased from them, but with 2800 plus feedback mentions, all positive, you are not risking much.

I think oletronix sells a lot of these GE JANs at slightly different prices depending on how strong they test, so you can spend a bit more with his other listings if you want matched tubes that test stronger. 

IMHO: If tubes test as new (like this particular set) I do not think there is an advantage in sound or expected lifespan over picking a set with even stronger output, but there is very little cost difference as well.


----------



## matthew23

That’s actually the seller I had in my cart...thanks. Heading to bed but thanks for your help, I learned a lot!


----------



## Ggroch

matthew23 said:


> That’s actually the seller I had in my cart...thanks. Heading to bed but thanks for your help, I learned a lot!



ONE More thing...based on Mordy's input.   When you are first trying any of the new tubes, disconnect from the Outlaw and just use the LD by itself at first.  As I understand it some of the biggest risk at damaging an amp comes when tubes go bad...sends nasty stuff out the preamp outputs.


----------



## mordy

matthew23 said:


> That is really scary. We’re you able to get it fixed?


Hi M23,
Outlaw Audio were very gracious and fixed my receiver for free (I had to pay for shipping).
One of my Polk Monitor50 speakers blew a driver, and I got new ones under the warranty and was able to install them myself. I don't know the reason why it went bad, whether from the speaker or the amp, but still an unpleasant and sobering experience.
Sent an email to Outlaw customer service to ask if the new RR2160 has protective circuitry.


----------



## matthew23

mordy said:


> Hi M23,
> Outlaw Audio were very gracious and fixed my receiver for free (I had to pay for shipping).
> One of my Polk Monitor50 speakers blew a driver, and I got new ones under the warranty and was able to install them myself. I don't know the reason why it went bad, whether from the speaker or the amp, but still an unpleasant and sobering experience.
> Sent an email to Outlaw customer service to ask if the new RR2160 has protective circuitry.


That is great.  I am glad to know that my receiver is backed by a good company...


----------



## matthew23

Ggroch said:


> ONE More thing...based on Mordy's input.   When you are first trying any of the new tubes, disconnect from the Outlaw and just use the LD by itself at first.  As I understand it some of the biggest risk at damaging an amp comes when tubes go bad...sends nasty stuff out the preamp outputs.


Thanks - new tubes arrive tonight so I will detach RCAs in back and let them run a bit.


----------



## mordy

matthew23 said:


> Thanks - new tubes arrive tonight so I will detach RCAs in back and let them run a bit.


Here is the definitive answer on how to connect the Little Dot to the RR2160:

_The EPL loop input on the RR2160 is direct coupled to the input switching chip.
Therefore, you cannot use that headphone pre-amp connected to that input.

The input of the main amp stage is capacitor coupled.
So, if you intend on using this headphone pre-amp with the RR2160, I would recommend you
only connect via the pre-out/main-in jacks.

Best Regards,
Jim Michelson_

In other words, do NOT use the external processor loop.


----------



## Ggroch (Mar 28, 2018)

mordy said:


> In other words, do NOT use the external processor loop.



Wow, I was wrong then.  I hope Mathew sees this.  Only been wrong once before 

If I understood you correctly, you hooked your LD to the  Main in of your different model Outlaw when it failed, so that may have been caused by something else. 

I think with this new information from Jim Michelson who should know, and from your experience, if it was my gear I would probably just hook the input of the LD to the tape REC OUT on the Outlaw.  Don't connect the Pre-out at all.  Use the LD for headphones and share the Outlaw as a source switcher.  

Otherwise, you are right, it looks like the Pre/Main is how to do it.  The problem is that then you have to physically disconnect the LD to get it out of the circuit if you do not want to use the tube preamp/buffer.


----------



## Johnybuchar

I can accept this awful experience. I wanted to use LD3 as a preamp with power part of Classé CAP151 (250w/4ohm/Channel!). I didn't know the instructions to wait for a while than LD3 stabilizes. I turned the power amplifier on and It sounded very loud hum from my standspeakers. Result was totally burnt bass speakers! That was LD3 as preamp for the first and last time .

I am tasting the Phillips JAN 5654W at this moment and I have to say WOOOW! I highly recommend them together with Tesla 6F32 and military Voshkod 6zh1p.


----------



## matthew23

mordy said:


> Here is the definitive answer on how to connect the Little Dot to the RR2160:
> 
> _The EPL loop input on the RR2160 is direct coupled to the input switching chip.
> Therefore, you cannot use that headphone pre-amp connected to that input.
> ...


Thanks for doing that!!!  I will unhook it and just like Ggroch suggests, use it in the REC out for headphone use only.  A bit disappointing because I wanted the "tube sound" through the receiver/speakers as well, but better to not risk frying anything.  Thanks so much to you both for all of your help!!


----------



## mordy

Ggroch said:


> Wow, I was wrong then.  I hope Mathew sees this.  Only been wrong once before
> 
> If I understood you correctly, you hooked your LD to the  Main in of your different model Outlaw when it failed, so that may have been caused by something else.
> 
> ...


Hi Gg,
When my receiver failed it was hooked up to the external processor loop - I did not know any better. It is possible that a voltage spike from the LD fried a speaker driver, which caused a short in the receiver, but I am only guessing.


----------



## mordy

matthew23 said:


> Thanks for doing that!!!  I will unhook it and just like Ggroch suggests, use it in the REC out for headphone use only.  A bit disappointing because I wanted the "tube sound" through the receiver/speakers as well, but better to not risk frying anything.  Thanks so much to you both for all of your help!!


Hi M23,

If you disconnect the U-shaped connector on the back of the receiver, you can connect the Little Dot in as a preamp, and use the amp in the receiver, and this will give you the tube sound through your speakers.


----------



## matthew23

mordy said:


> Hi M23,
> 
> If you disconnect the U-shaped connector on the back of the receiver, you can connect the Little Dot in as a preamp, and use the amp in the receiver, and this will give you the tube sound through your speakers.


If I do that, what functionality do I lose with the amp?  I primarily use it with my turntable but also use the network connection to stream over DLNA. If I do hook it up and get the "tube sound" does that mean I have to unhook it if I want to turn the amp off and run stock or is there a way to leave it plugged in and bypass it to run stock?

Also, does that effect the way it is used as a headphone amplifier too?

Thanks!


----------



## mordy (Mar 28, 2018)

I assume that you lose all the preamp functions such as volume control, bass treble, balance etc. Everything will be controlled by the LD.
However, it’s a long time ago that I had this setup, and you have the newest model, so my suggestion is to email Outlaw customer service with all your questions.
They are very responsive and knowledgeable and will help you with your setup.


----------



## pichu

So my little dot mk2 has a problem. On the front face of the amp there is a connection or pressure problem and I’m not sure what to do. When I plug in the headphones there is a big channel imbalance and the volume is a lot lower than it reads on the volume pot. The only way to fix this is to put a lot of pressure on the front face panel. If I use my hand to push down next to the volume pot, then the amp pushes out the right sound. I want to fix this but I’m not sure what I would have to do? Is it a bad connection with the volume pot? Is the headphone output messed up? Any advice on this?


----------



## mattrudy80

pichu said:


> So my little dot mk2 has a problem. On the front face of the amp there is a connection or pressure problem and I’m not sure what to do. When I plug in the headphones there is a big channel imbalance and the volume is a lot lower than it reads on the volume pot. The only way to fix this is to put a lot of pressure on the front face panel. If I use my hand to push down next to the volume pot, then the amp pushes out the right sound. I want to fix this but I’m not sure what I would have to do? Is it a bad connection with the volume pot? Is the headphone output messed up? Any advice on this?


I had a similar problem with my MKIV. I had to pull the headphone plug out about 1/16" to 1/8" for the R/L channels and ground to line up correctly. If you're using a 1/8" to 1/4" adapter it may be wise to try a different one. I just left mine pulled out slightly.


----------



## pichu

mattrudy80 said:


> I had a similar problem with my MKIV. I had to pull the headphone plug out about 1/16" to 1/8" for the R/L channels and ground to line up correctly. If you're using a 1/8" to 1/4" adapter it may be wise to try a different one. I just left mine pulled out slightly.


It’s frustrating to have it this way. Sometimes makes me second guess if I’m getting the correct sound out of the amp


----------



## Whelkie D

pichu said:


> So my little dot mk2 has a problem. On the front face of the amp there is a connection or pressure problem and I’m not sure what to do. When I plug in the headphones there is a big channel imbalance and the volume is a lot lower than it reads on the volume pot. The only way to fix this is to put a lot of pressure on the front face panel. If I use my hand to push down next to the volume pot, then the amp pushes out the right sound. I want to fix this but I’m not sure what I would have to do? Is it a bad connection with the volume pot? Is the headphone output messed up? Any advice on this?


I had a similar problem with mine a while ago - only one channel working unless I pressed hard on the top surface. Couldn't work out what was happening. Then I tried re-seating the main fuse (next to the power input). For some reason this seemed to sort it out. Also make sure the power lead is firmly in the socket on the LD. Hope this helps.


----------



## pichu

Whelkie D said:


> I had a similar problem with mine a while ago - only one channel working unless I pressed hard on the top surface. Couldn't work out what was happening. Then I tried re-seating the main fuse (next to the power input). For some reason this seemed to sort it out. Also make sure the power lead is firmly in the socket on the LD. Hope this helps.


Seems like a QC thing. Thanks for this. I will try it out when I get home


----------



## TrollDragon (Mar 30, 2018)

I've had the board out of my MK IV long ago to replace the cheap stock "Neutrik style" headphone jack and to make a schematic for it.  I touched up all the sketchy solder joints on the board at that point in time.

Getting proper sound by pressing on the case would most likely be a cold solder joint in the amp and that would be an easy fix for someone with basic soldering skills. The tedious part is pulling the board out of the case on a MK III or MK IV.

The MK II would be quite easy since the case is in two pieces.


----------



## shepperd (Apr 8, 2018)

A bit off the present discussion but nonetheless...Of all the tubes I have tried, I still find the Voshkod the best all-round. I found an earlier version, 74' I think, and was hoping for something special but...it's a nice tube but is a step down from it's later version. It is non-ribbed and dooesn't look to be as rugged. That's probably why they changed the construction. There are still some I haven't tried but I got kind of tird of the obsession. The one tube I miss was the pair of Teslas that died on me before they were broken in. Never could find another set. If anyone has had experience with those rather pricey Telefunken I would like to know their experience. I was listening just to a pair of very old (44') Tungsols and found them rather harsh. So age is not necissarily the most important criteria. My two sets of Voshkod are from the late 80's and they are really quite special. It's worth repeating, at the expense of being a bore, that they need a LOT of time to burn in, more than any tube I have tried.


----------



## capetownwatches

shepperd said:


> My two sets of Voshkod are from the late 80's and they are really quite special..



Interesting. Most opinions reckon the earlier versions are "better" and that production values had already started dropping by the early '80s in USSR.

Are your tubes 6ZH1P with OTK marking?


----------



## shepperd

Yes, common thought says older is better and there are reasons why but in this case apparently not. I doubt these 73' Voshkod need the same length of time to burn in as the newer ones since after 30 hours they haven't changed so...so in the end all one can say with any certainty is tubes are like anything else: how they will sound is system dependant and of course a matter of taste. The elusive perfect tube will remain just that...elusive! Markings...OTK1, rocket symbol, a losange with a 2, and in Russian 6Xsomething-EB and then 73. same as the later version excepting the date. The inner construction appears identical. The only thing that has changed is the ribbed glass. Weird...


----------



## mordy

shepperd said:


> Yes, common thought says older is better and there are reasons why but in this case apparently not. I doubt these 73' Voshkod need the same length of time to burn in as the newer ones since after 30 hours they haven't changed so...so in the end all one can say with any certainty is tubes are like anything else: how they will sound is system dependant and of course a matter of taste. The elusive perfect tube will remain just that...elusive! Markings...OTK1, rocket symbol, a losange with a 2, and in Russian 6Xsomething-EB and then 73. same as the later version excepting the date. The inner construction appears identical. The only thing that has changed is the ribbed glass. Weird...


The common wisdom is that the earlier tubes were better made because of worker pressure under communism. As communism began to crumble, the quality went down.
But there are always exceptions to every rule....
The OTK symbol is supposed to mean nothing - it is akin to being inspected by #3 or whatever number the inspector had.


----------



## shepperd

I knew that. I was just replying to the question; "Are your tubes 6ZH1P with OTK marking?". As for old tubes, yes it's pretty clear that when tubes were in their hey-day, being made by people skilled and using machines that were still fresh, they should be of better quality and hence sound better. I will have to bite the bullet and go back and listen to the whole lot to re-test my appreciation. I am pretty sure though that my 88' Vosh. will come out on top. It's supremely ironic that many of the tubes we talk about were intended for military use and no one had an inkling they would find a second life in audio applications. I find that rather sweet and oddly comforting. From missles and migs to headphone rigs!


----------



## Whelkie D

shepperd said:


> I knew that. I was just replying to the question; "Are your tubes 6ZH1P with OTK marking?". As for old tubes, yes it's pretty clear that when tubes were in their hey-day, being made by people skilled and using machines that were still fresh, they should be of better quality and hence sound better. I will have to bite the bullet and go back and listen to the whole lot to re-test my appreciation. I am pretty sure though that my 88' Vosh. will come out on top. It's supremely ironic that many of the tubes we talk about were intended for military use and no one had an inkling they would find a second life in audio applications. I find that rather sweet and oddly comforting. From missles and migs to headphone rigs!


My thoughts exactly sheppherd.


----------



## L0rdGwyn

I no longer have a 6N6P compatible amp, maybe someone here can use these?  Check my signature.


----------



## tha_freak

capetownwatches said:


> Interesting. Most opinions reckon the earlier versions are "better" and that production values had already started dropping by the early '80s in USSR.
> 
> Are your tubes 6ZH1P with OTK marking?



Hi I'm new here... have a LittleDot Mk III and a pair of Senn HD579 that I like quite a lot…

After reading the article on the tube rolling for the LittleDot, I decided to try the Voshkod 6ZH1P-EV to replace the standard 5654 driver tubes since they seems the nicest of the lot in the “95” category.

My question, will I have to change jumpers positions for these or they are the same as the 5654 ?

Thanks in advance !!


----------



## Ggroch (Apr 16, 2018)

tha_freak said:


> My question, will I have to change jumpers positions for these or they are the same as the 5654 ?
> 
> Thanks in advance !!



No jumper changing needed.  Same as the 5654 This Post is very helpful on the topic.


----------



## tha_freak

Ggroch said:


> No jumper changing needed.  Same as the 5654 This Post is very helpful on the topic.



Thanks, I red the article and I was not sure what they meant by « factory configured » just wanted do be sure...

Are they good upgrades ? In the article they where rated 95/100...

Another question, any gain changing the « power tubes » ?


----------



## Tony51

tha_freak said:


> Thanks, I red the article and I was not sure what they meant by « factory configured » just wanted do be sure...
> 
> Are they good upgrades ? In the article they where rated 95/100...
> 
> Another question, any gain changing the « power tubes » ?



The jan5654w are my second best. But if you go with the Mullard M8161/CV4015 you will acchieve higher dynamics and a tad of better bass. They are fantastic!! Also as you raise the volume, all frequencies stay together, the treble doesn't run ahead leaving the bass behind neither will the bass run ahead of the treble. So I can blast my ears and not get ear fatigue because the treble ran way ahead of the rest of the instruments. As for power tubed, I use the 50 bucks super tubes which are Russian Sovtek cryoset matched and these supplied a little more overall power output over the regular gold grid Russian power tubes.


----------



## Whelkie D

tha_freak said:


> Thanks, I red the article and I was not sure what they meant by « factory configured » just wanted do be sure...
> 
> Are they good upgrades ? In the article they where rated 95/100...
> 
> Another question, any gain changing the « power tubes » ?


 The Voskhod are very good as are the Mullard 8100s but both for different reasons. One tube that (to me) has the best characteristics of both of these is the Yugoslavian 6HM5 which (surprisingly) is not reviewed in the original post. Again, no jumper change is required for these.  

https://www.ebay.co.uk/itm/6HM5-EC9...e=STRK:MEBIDX:IT&_trksid=p2060353.m1438.l2649


----------



## sghound (Apr 16, 2018)

guys the 1st page recs are outdated.

pls refer to the last endgame list

https://www.head-fi.org/threads/lit...e-rolling-guide.563884/page-585#post_11155053


----------



## sghound

Whelkie D said:


> The Voskhod are very good as are the Mullard 8100s but both for different reasons. One tube that (to me) has the best characteristics of both of these is the Yugoslavian 6HM5 which (surprisingly) is not reviewed in the original post. Again, no jumper change is required for these.
> 
> https://www.ebay.co.uk/itm/6HM5-EC900-Lot-of-four-4-tubes-EI-Yugoslavia-NOS-free-shipping/251611916081?ssPageName=STRK:MEBIDX:IT&_trksid=p2060353.m1438.l2649



yep 6HM5 is the best driver option before entering C3G territory.


----------



## Johnybuchar (Apr 17, 2018)

And a smaller version https://www.ebay.co.uk/itm/EC900-6HM5-Lot-of-four-4-tubes-EI-Yugoslavia-Philips-construction-1987/261599117610?_trkparms=aid=222007&algo=SIM.MBE&ao=1&asc=43630&meid=55af112840db40f58032ceb808f3a0a9&pid=100005&rk=1&rkt=3&sd=251611916081&itm=261599117610&_trksid=p2047675.c100005.m1851 ? Has someone compared with former "taller" 6HM5? I own these small 6HM5, they sound slightly bright. BTW I am burning-in Mullard 8100 ..... superb .


----------



## sghound

yeah the taller ones are legit.


----------



## Johnybuchar

Ok I will complete a collection . The small EI 6HM5 tubes sound very good too but aren't all-rounders as e.g. Tesla 6F32 for my ears.


----------



## gibosi

Johnybuchar said:


> And a smaller version https://www.ebay.co.uk/itm/EC900-6HM5-Lot-of-four-4-tubes-EI-Yugoslavia-Philips-construction-1987/261599117610?_trkparms=aid=222007&algo=SIM.MBE&ao=1&asc=43630&meid=55af112840db40f58032ceb808f3a0a9&pid=100005&rk=1&rkt=3&sd=251611916081&itm=261599117610&_trksid=p2047675.c100005.m1851 ? Has someone compared with former "taller" 6HM5? I own these small 6HM5, they sound slightly bright. BTW I am burning-in Mullard 8100 ..... superb .



I have a pair of short bottles manufactured by Siemens and I was not impressed. However, I had no idea that EI manufactured the small bottle version and thus I can't say how they might sound.


----------



## Whelkie D

gibosi said:


> I have a pair of short bottles manufactured by Siemens and I was not impressed. However, I had no idea that EI manufactured the small bottle version and thus I can't say how they might sound.


Yes, I've only recently started seeing the short bottle Ei version. Wonder where they've been hiding.


----------



## frogmeat69

Have some 6DT6A Sylvania tubes, and can't remember what settings, and if they are compatible with either the 1+, Mkiii, or both.
And for the life of me, I can't remember the page with all of the tube settings, sorry. Please help, lol.


----------



## mattrudy80

frogmeat69 said:


> Have some 6DT6A Sylvania tubes, and can't remember what settings, and if they are compatible with either the 1+, Mkiii, or both.
> And for the life of me, I can't remember the page with all of the tube settings, sorry. Please help, lol.


I think it's page 77.


----------



## frogmeat69

mattrudy80 said:


> I think it's page 77.


Yes it is, thank you.


----------



## WilliamLeonhart

I've just decided to stash 10 more tall-bottle EI 6hm5 in my house. I love this addictive colored sound. It turns my mk4 clone into something else entirely.


----------



## gulakpii

I rolled many tubes on my LD Mk4 and I have the 6ZH1P-EV and the 6HM5. 
IMHO, the 6HM5 is a much better all-arounder, that is, before you tried the C3g, which is much pricier and needs adapters!
Luckily, the 6HM5's are surprisingly inexpensive and are plug-in compatible to EF95, which is the greatest news to us!


----------



## TrollDragon

mickyjohn said:


> you can always see robot vacuums for dog hairs here.


A little confused are we??


----------



## doordie97

So guys, quick Mk 2 suggestion. 

Going for voskhods 6zh1p and also sylvania GB5654. Might pick up some 6hm5 along the way and are GE JAN 5654 worth it? 

Power tube recommendations? Seems like 6N6P-IR are well sought after here and cheap. Can those 6H30P work with MK2 without an adapter or changing jumper settings? 

Much appreciated guys and happy rolling!


----------



## Whelkie D

doordie97 said:


> So guys, quick Mk 2 suggestion.
> 
> Going for voskhods 6zh1p and also sylvania GB5654. Might pick up some 6hm5 along the way and are GE JAN 5654 worth it?
> 
> ...



Personally. I've found the GE "5 Star" a slightly better choice than the JAN5654. Seem a bit more detailed. Maybe just my ears though. Definitely try the 6HM5s but make sure you get the taller version. Good luck.


----------



## doordie97

Whelkie D said:


> Personally. I've found the GE "5 Star" a slightly better choice than the JAN5654. Seem a bit more detailed. Maybe just my ears though. Definitely try the 6HM5s but make sure you get the taller version. Good luck.


Thanks man. Suggestions for power tubes? Tbh i'd like to play safe and go for the swap and play types without messing around too much with the circuitry.


----------



## WilliamLeonhart

Whelkie D said:


> Personally. I've found the GE "5 Star" a slightly better choice than the JAN5654. Seem a bit more detailed. Maybe just my ears though. Definitely try the 6HM5s but make sure you get the taller version. Good luck.


Are the GE 5 star carry the same sound sig as the JAN5654 though? I do like the JAN because its tubey neutral sound  play really  well with Rock music. An improvement over that very sound will be very welcome


----------



## Whelkie D

doordie97 said:


> Thanks man. Suggestions for power tubes? Tbh i'd like to play safe and go for the swap and play types without messing around too much with the circuitry.


I use either the Russian 6N6P or the 6N6 IRs. Both are very good, however I found the IR version a bit too bright with the Voskhod drivers, but again that may be just me and my ears.


----------



## Whelkie D

WilliamLeonhart said:


> Are the GE 5 star carry the same sound sig as the JAN5654 though? I do like the JAN because its tubey neutral sound  play really  well with Rock music. An improvement over that very sound will be very welcome


As I say, the 5 Star seemed a bit more detailed to me than the JAN5654. Not much between them TBH though, and both really good for rock. Both seem to go well with female vocals as well, (Joni Mitchell's Hejira album sounds amazing with them.)


----------



## Johnybuchar (Apr 22, 2018)

JAN 5654W are a better choice than 5Star tubes for me. Incredible ratio quality/price has Tesla 6F32 and Voshgod 6zh1p-ev. I've tested Voshgod date 1985. Russian power tubes are very affordable.


----------



## doordie97

Guys, Sylvania GB5654 or Telefunken/AEG 5654? I just can’t decide which ones to get. I already have the Raytheon 5654 and Ge Jan 5654W.


----------



## Johnybuchar

I assume that Telefunken is a better choice. This brand is one of the most famous tube producers and you can't do a mistake with them .


----------



## CatBroiler (Apr 28, 2018)

I decided to get a Little dot Mk.II, and I got Novosibirsk 6N6Ps and British Mullard M8100s.
Compared to my solid state amp (Sabaj D3), the tubes have made my DT990s a lot less bitey in the highs (though admittedly I do sometimes enjoy the bitieness) and a lot warmer in the mids and lows.
As a side note I'm still using the DAC in the Sabaj D3, and I've ordered a pair of Voshkod 6J1P-EVs and GE5654Ws to try out.


----------



## doordie97

Still wondering which power tubes to get.... Can't decide between the 6H6P and the 6H6P-IRs, or even 6H30Ps are a welcome edition, tho they are expensive. Thoughts?


----------



## frogmeat69

doordie97 said:


> Still wondering which power tubes to get.... Can't decide between the 6H6P and the 6H6P-IRs, or even 6H30Ps are a welcome edition, tho they are expensive. Thoughts?


I have the 6N6p-IR tubes which seem to be a good choice from this seller 2 years ago, https://www.ebay.com/itm/6N6P-IR-EC...eDoubleTriode-Gold-Grid-NEW-OTK-/171310973012 .
Search around, you can prolly find them cheaper.


----------



## shepperd

Anyone have a pair of Tesla 6F32 to sell? Mine died imidiately after using them and I would like to hear them again. I'm in France.


----------



## Johnybuchar

I know the czech seller, I bought them from him. Total bargain. I am going to check it if he still offers and let you know.


----------



## shepperd

Thanks. Appreciated


----------



## Johnybuchar

This seller on the eBay:
https://www.ebay.com/usr/petr0888?_trksid=p2047675.l2559

You will contact him on his email "ko@email.cz" if he is unavailable on ebay .


----------



## shepperd

No luck with him. one of our members has kindly answered my request and I will go with that. Damn these things are incredibly hard to find! I would/should live happily ever after with the tubes I have but the urge has come upon me and there's no denying it .


----------



## willne1

Are all of the 6N6P-IR Tubes created equally or do I need to look to make sure they were manufactured in a certain factory? Also I see Gold Grid mentioned in the description of some of them, is that something I need to look out for or are they all the same?


----------



## mordy

willne1 said:


> Are all of the 6N6P-IR Tubes created equally or do I need to look to make sure they were manufactured in a certain factory? Also I see Gold Grid mentioned in the description of some of them, is that something I need to look out for or are they all the same?


Hi w1,
I would just go for the least expensive IRs - did not see anywhere that different factories make a difference.
The gold grid was invented by US manufacturers but they never made any splash about it and I don't think it matters much - just good ol' marketing hype. The amount of gold is minuscule.
From experience I have seen that tubes with copper rods may sound better, and the Russian tube pins make be coated with Rhodium which is good since they do not corrode easily.


----------



## willne1

mordy said:


> Hi w1,
> I would just go for the least expensive IRs - did not see anywhere that different factories make a difference.
> The gold grid was invented by US manufacturers but they never made any splash about it and I don't think it matters much - just good ol' marketing hype. The amount of gold is minuscule.
> From experience I have seen that tubes with copper rods may sound better, and the Russian tube pins make be coated with Rhodium which is good since they do not corrode easily.


Thanks for the fast response mordy, that makes the hunt a little easier.


----------



## warp2600 (May 17, 2018)

Hi fellow forum members,

I have recently replaced the driver tubes (for Sylvania) in my MK III and just now I noticed that one of the tubes has a black spot (ca. 1cm) on the top, where there is the silvery coating. I don't think it has been there when I inserted the tubes. The sound seems to be OK in both channels though. Do you think I should remove the tubes?


----------



## mordy

warp2600 said:


> Hi fellow forum members,
> 
> I have recently replaced the driver tubes (for Sylvania) in my MK III and just now I noticed that one of the tubes has a black spot (ca. 1cm) on the top, where there is the silvery coating. I don't think it has been there when I inserted the tubes. The sound seems to be OK in both channels though. Do you think I should remove the tubes?


Hi w2600,
As long as everything sounds fine I would just ignore it. The silver coating (getter flash) is just a coating of Barium to help to maintain a vacuum in the tube. Sometimes this coating is brownish or blackish - doesn't matter. 
The only time to worry is when the coating turns white. This means the kiss of death to the tube, because it indicates that the vacuum is lost.


----------



## warp2600

mordy said:


> Hi w2600,
> As long as everything sounds fine I would just ignore it. The silver coating (getter flash) is just a coating of Barium to help to maintain a vacuum in the tube. Sometimes this coating is brownish or blackish - doesn't matter.
> The only time to worry is when the coating turns white. This means the kiss of death to the tube, because it indicates that the vacuum is lost.


Thanks, Mordy.
In the meantime I took the Sylvania out just to be safe. I didn't want it to explode or something. I inserted a pair of Russian tubes 6zh1p-EV but I am not so fond of their sound. I loved the Mullards the most. They were wonderful. The Sylvania pair was very good too. I remember that the Russian tubes are said to require a long burn-in period.


----------



## doordie97

Guys, is this seller for the Tesla’s reputable? https://rover.ebay.com/rover/0/0/0?mpre=https://www.ebay.com.my/ulk/itm/183204647134


----------



## housekrl

Hello,
I do a fair amount of tube rolling in my mk3. Does anyone know where I can buy 7 pin socket savers that will work for this amp? I have hunted high an low.
Btw, i love this thread


----------



## Whelkie D

housekrl said:


> Hello,
> I do a fair amount of tube rolling in my mk3. Does anyone know where I can buy 7 pin socket savers that will work for this amp? I have hunted high an low.
> Btw, i love this thread


https://www.ebay.co.uk/itm/1-7Pin-G...859400?hash=item284779d848:g:0eAAAOSwCGVX~FOp


----------



## housekrl

Thanks alot. I ordered a couple.


----------



## frogmeat69

housekrl said:


> Hello,
> I do a fair amount of tube rolling in my mk3. Does anyone know where I can buy 7 pin socket savers that will work for this amp? I have hunted high an low.
> Btw, i love this thread


Leeds Radio on Etsy carries them, but from his page it looks like he only has 1 left, could check if he will get more,  https://www.etsy.com/listing/213863...ch_query=7+pin+socket&ref=shop_items_search_1


----------



## TrollDragon

Whelkie D said:


> https://www.ebay.co.uk/itm/1-7Pin-G...859400?hash=item284779d848:g:0eAAAOSwCGVX~FOp


Those look a little big in diameter, you might have to remove the bezel rings on the MKIII. They are screwed on from underneath though.


----------



## Whelkie D

housekrl said:


> Thanks alot. I ordered a couple.


Found these as well............................https://www.ebay.co.uk/itm/1Piece-M...5-6AQ5-6AU6-/192126068641?hash=item2cbb9b27a1


----------



## doordie97

Guys, does anyone know whether these socket savers work?
https://www.amazon.co.uk/Cayyi-Bake...pID=51fYHWwnSCL&preST=_SY300_QL70_&dpSrc=srch


----------



## mordy

doordie97 said:


> Guys, does anyone know whether these socket savers work?
> https://www.amazon.co.uk/Cayyi-Bake...pID=51fYHWwnSCL&preST=_SY300_QL70_&dpSrc=srch





doordie97 said:


> Guys, does anyone know whether these socket savers work?
> https://www.amazon.co.uk/Cayyi-Bake...pID=51fYHWwnSCL&preST=_SY300_QL70_&dpSrc=srch


Hi d97,
Your best bet is to measure the hole of the socket on the MKIII and then contact the seller for the measurements of the socket saver.
It is quite difficult to remove the bezel rings around the socket cut outs. 
'In the past I used cheap socket savers from Cary for 9pin tubes (not 7pin) to be able to insert adapters for power tubes that did not fit into the cutouts because of the bezels.


----------



## doordie97

mordy said:


> Hi d97,
> Your best bet is to measure the hole of the socket on the MKIII and then contact the seller for the measurements of the socket saver.
> It is quite difficult to remove the bezel rings around the socket cut outs.
> 'In the past I used cheap socket savers from Cary for 9pin tubes (not 7pin) to be able to insert adapters for power tubes that did not fit into the cutouts because of the bezels.



Hi Mordy, I am using the mk2 instead of the mk3. Would contact the seller if necessary but my main question is that how would these work with the mk2 coz the standard ones i see have the pins coming out from it whereas this one has holes coming out of it. Any insight on this. Thanks


----------



## frogmeat69 (May 27, 2018)

doordie97 said:


> Guys, does anyone know whether these socket savers work?
> https://www.amazon.co.uk/Cayyi-Bake...pID=51fYHWwnSCL&preST=_SY300_QL70_&dpSrc=srch


Has to be for a 7 pin mini, and there is no center post on mine, no place for it to go on the socket, AFAIK.


----------



## Whelkie D

doordie97 said:


> Hi Mordy, I am using the mk2 instead of the mk3. Would contact the seller if necessary but my main question is that how would these work with the mk2 coz the standard ones i see have the pins coming out from it whereas this one has holes coming out of it. Any insight on this. Thanks


I am using these with the MK2 and they work fine. However when they arrived I found the pins were a bit too long but after a bit of trimming they fit perfectly
https://www.ebay.co.uk/itm/1Piece-M...5-6AQ5-6AU6-/192126068641?hash=item2cbb9b27a1


----------



## mordy

Whelkie D said:


> I am using these with the MK2 and they work fine. However when they arrived I found the pins were a bit too long but after a bit of trimming they fit perfectly
> https://www.ebay.co.uk/itm/1Piece-Mini-7Pin-tube-test-saver-for-6X4-6AK5-5654-EC90-EC92-6J1-EF95-6AQ5-6AU6-/192126068641?
> hash=item2cbb9b27a1


Hi WD,
Which method do you use to trim the pins? I tried cutting pliers in the past, but the edges are too sharp.


----------



## Whelkie D

mordy said:


> Hi WD,
> Which method do you use to trim the pins? I tried cutting pliers in the past, but the edges are too sharp.


I used some wire snips and then "rounded" the ends off with a small file. Fiddly, but it seems to work.


----------



## mordy

Whelkie D said:


> I used some wire snips and then "rounded" the ends off with a small file. Fiddly, but it seems to work.


Thanks


----------



## doordie97

Guys, ive just changed to a pir of 6n6p on my little dot mk2 and when i turn off the amp after a session i hear crackling noises... probably from the tubes is this normal?


----------



## frogmeat69

I always unplug my headphones before I turn off my Mk3, and plug them in after letting it warm up for around 20 minutes, so never hear anything except for a bit of ringing from the tubes when first inserting the plug.


----------



## doordie97

frogmeat69 said:


> I always unplug my headphones before I turn off my Mk3, and plug them in after letting it warm up for around 20 minutes, so never hear anything except for a bit of ringing from the tubes when first inserting the plug.


I’m pretty sure it’s from the power tubes not from the headphones... tried every possible combination of unplugging and plugging in but the crackle is still present... audible from the power tubes


----------



## doordie97

doordie97 said:


> I’m pretty sure it’s from the power tubes not from the headphones... tried every possible combination of unplugging and plugging in but the crackle is still present... audible from the power tubes


So guys, any insight on this. I’ve read the previous threads and I’m pretty sure it’s not RF noise, it comes from the tubes themselves and it’s not audible in my headphones. Thanks guys


----------



## willne1

It might be a long shot but did you check the pins on the tubes to make sure they're clean of any corrosion?


----------



## doordie97

willne1 said:


> It might be a long shot but did you check the pins on the tubes to make sure they're clean of any corrosion?


Did check them out they seem to be fine. Doesn’t corrosion affect the overall sound as well? The sound is fine, just that there are crackling noises from the tubes after I turn it off, lasts for about 10-15 seconds... could it be a grounding issue?


----------



## gibosi

I wonder if what you are hearing is similar to the sounds a hot automobile engine makes after it is turned off, those popping and tinkling sounds. In a similar way, as tubes cool down, the metal components inside begin to contract. And as they cool down and contract, they need to move a bit, relative to each other, but some pieces are joined together. So as they begin to cool down, tension builds up until one piece suddenly slips against another piece. And as they slip-and-catch, slip-and-catch, we hear pops and tinkling sounds.

Obviously, some tubes are more prone to this than others. In a different amp, the 5998, which is an enhanced version of the 6AS7, is notorious for these popping and tinkling sounds, both as it heats up and as it cools down.

So if this is what you are hearing, then it is perfectly normal, nothing to worry about....


----------



## mordy

gibosi said:


> I wonder if what you are hearing is similar to the sounds a hot automobile engine makes after it is turned off, those popping and tinkling sounds. In a similar way, as tubes cool down, the metal components inside begin to contract. And as they cool down and contract, they need to move a bit, relative to each other, but some pieces are joined together. So as they begin to cool down, tension builds up until one piece suddenly slips against another piece. And as they slip-and-catch, slip-and-catch, we hear pops and tinkling sounds.
> 
> Obviously, some tubes are more prone to this than others. In a different amp, the 5998, which is an enhanced version of the 6AS7, is notorious for these popping and tinkling sounds, both as it heats up and as it cools down.
> 
> So if this is what you are hearing, then it is perfectly normal, nothing to worry about....


Hi d97,
Just to cover all bases, take a dull little knife and gently scrape the tube pins all around. Many times the various sounds from the tube disappear after burning in the the tubes - usually in the 30-50 hour range.


----------



## Whelkie D

I've had this with newly installed NOS tubes. Odd clicks and pops. With me these have disappeared after burn-in of 15 - 20 hours. I think it is just bits of oxidisation on the pins which "burns off" after a bit of use.


----------



## doordie97

Whelkie D said:


> I've had this with newly installed NOS tubes. Odd clicks and pops. With me these have disappeared after burn-in of 15 - 20 hours. I think it is just bits of oxidisation on the pins which "burns off" after a bit of use.


Thanks for the info man, at least now i know what i'm dealing with. Cheers


----------



## doordie97

Any 6hm5 listing recommendations? thanks  should i go for the yugoslavian ones or the general electric ones. both are tall tubes what is the difference. Thanks again guys you peeps are awesome


----------



## mordy

Hi d97,
I have the Yugoslavian Ei tubes and they are very good. Here is a seller that will sell you a pair for $14 shipped:
https://www.ebay.com/itm/6HM5-6HA5-...467071?hash=item460dd0523f:g:UJ0AAOxyyF5RN3~H


----------



## sghound

doordie97 said:


> Any 6hm5 listing recommendations? thanks  should i go for the yugoslavian ones or the general electric ones. both are tall tubes what is the difference. Thanks again guys you peeps are awesome



yugo tall boy


----------



## doordie97

mordy said:


> Hi d97,
> I have the Yugoslavian Ei tubes and they are very good. Here is a seller that will sell you a pair for $14 shipped:
> https://www.ebay.com/itm/6HM5-6HA5-...467071?hash=item460dd0523f:g:UJ0AAOxyyF5RN3~H


thanks mordy. Appreciate it. will get them ASAP


----------



## TrollDragon (Jun 3, 2018)

Did someone say Yugo...


----------



## mordy

TrollDragon said:


> Did someone say Yugo...


Hi TD,
The first time I used the Yugo Ei 6HM5 I thought my amp was going to blow up because of the flash from the pre-heat feature of these tubes......
Nothing to worry about, though.


----------



## shepperd

I had the same experience and they got so hot I stopped using them. I just found these, which I had never seen before. Anyone heard them? https://www.ebay.com/p/Ei-6HA5-EC900-Vintage-Tube/168051561?iid=362168495484


----------



## Johnybuchar (Jun 4, 2018)

Hi Shepperd,
I bought these little 6AH5 from the Yugoslavia. They sound a little bright with my LD3+Shure940. I usually put them if I have a taste to listen vocal and instrumental music. They light up like a comet after turning on . High recommendations.


----------



## tim273

Whew, glad it's not just me having them light up when they first turn on, I got freaked out too, but for me it's only one of them and not the other.  Thought it was going to blow out or something.


----------



## mordy

shepperd said:


> I had the same experience and they got so hot I stopped using them. I just found these, which I had never seen before. Anyone heard them? https://www.ebay.com/p/Ei-6HA5-EC900-Vintage-Tube/168051561?iid=362168495484


Hi shepperd,
It is normal for tubes to get hot in operation - some of the 2.5A tubes (not for LD MKIII) can run 250F. I would not worry if the tube gets hot. The real worry is if the amp itself gets too hot. Good ventilation is a must, and I routinely have a fan going (old 4" PC fan) that draws hot air away from my amp.
Another way to reduce heat build-up in the amp is to use a socket saver between the amp socket and the tube with the added benefit that your amp socket does not wear out if you roll tubes often.
Is there any tube roller that didn't burn his fingers from the tubes?


----------



## shepperd

I guess I have to confess, yet again, that I am piggy backing on the experience of you chaps and all my tube rolling has to do with a pre amp.
I actually prefer the other tall boy variant. It doen't flash and runs reasonably hot. Before I invest in any new tubes, I want to get those Tesla's if they are still available. Unfortunately money goes thru my fingers and ends up in my car for repairs so no joy


----------



## gibosi

tim273 said:


> Whew, glad it's not just me having them light up when they first turn on, I got freaked out too, but for me it's only one of them and not the other.  Thought it was going to blow out or something.



This heater flash is relatively common with tubes manufactured in Europe, and especially those manufactured using Philip's equipment, as is the case with the Ei 6HM5. It is most certainly not a defect.

Without going into too much detail, the flash is a result of the way the heater is constructed. In the US, a number of runs of straight wire was typical. While some American tubes do exhibit this heater flash, it is not common. However, in Europe, one or more runs of tightly coiled wire was more common. And as result of using coiled wire, the uncoated section below the cathode is longer, and thus it heats up more quickly, resulting in the flash we often see. And since the flash was merely an unintended side-effect and not considered a defect, no attempt was ever made to eliminate it. And further, the amount of flash is inconsistent from tube to tube, with some flashing quite a bit and others hardly at all.


----------



## mordy

gibosi said:


> This heater flash is relatively common with tubes manufactured in Europe, and especially those manufactured using Philip's equipment, as is the case with the Ei 6HM5. It is most certainly not a defect.
> 
> 
> Without going into too much detail, the flash is a result of the way the heater is constructed. In the US, a number of runs of straight wire was typical. While some American tubes do exhibit this heater flash, it is not common. However, in Europe, one or more runs of tightly coiled wire was more common. And as result of using coiled wire, the uncoated section below the cathode is longer, and thus it heats up more quickly, resulting in the flash we often see. And since the flash was merely an unintended side-effect and not considered a defect, no attempt was ever made to eliminate it. And further, the amount of flash is inconsistent from tube to tube, with some flashing quite a bit and others hardly at all.


Hi gibosi,
Somebody stated that the heater flash heats up the tube quicker to working temperature. Is this incorrect?


----------



## gibosi

No. Again, this is the uncoated section of the heater located below the cathode. This flashing has no effect on the coated section located inside the cathode.


----------



## KeithEmo (Jun 5, 2018)

In general, wire has a lower resistance when it cold... so, for example, incandescent light bulbs actually draw more current until they get hot.

I definitely remember a few tubes in the old days that were specifically designed to heat up quickly and their filament would flare yellow hot for a few seconds.
That flash was the filament drawing a lot of current while cold so it would warm up more quickly...
(Having to wait for tubes to warm up was considered a major drawback...)

>
EDIT - more info....
This is widely reported with tubes of many different brands - mostly Mullard.
In general it should NOT affect performance or life expectancy.
I have definitely seen this claimed to be "a fast heat filament" in some old tube guides and ads.
The only recent mention I could find was here:  http://www.ozvalveamps.org/standby.htm
(search under "rapid" - claimed as a feature on some RCA tubes - including their 12AX7)




tim273 said:


> Whew, glad it's not just me having them light up when they first turn on, I got freaked out too, but for me it's only one of them and not the other.  Thought it was going to blow out or something.


----------



## doordie97

well, mk2 starting to smoke after a while of use. How can i contact little dot?


----------



## doordie97

doordie97 said:


> well, mk2 starting to smoke after a while of use. How can i contact little dot?


Guys, any help?


----------



## gibosi

I don't really know, but you might want to poke around their web site:

http://www.littledot.net/forum/index.php


----------



## doordie97

gibosi said:


> I don't really know, but you might want to poke around their web site:
> 
> http://www.littledot.net/forum/index.php


Yeah searched around and found their email. Sent an email directly to David hope he replies soon thanks anyway bro


----------



## mordy (Jun 12, 2018)

doordie97 said:


> Guys, any help?





gibosi said:


> I don't really know, but you might want to poke around their web site:
> 
> 
> doordie97 said:
> ...



Hi d97,
I empathize with you - it is a terrible feeling when your beloved amps blows up. This is what happened to my Little Dot MKIII two years ago when I used a faulty adapter. One channel went dead after a puff of acrid smoke. All four tubes light up but the right channel is dead.
I contacted David Zhe Zhe of Little Dot. The repair would cost $20-30 depending of what the problem was, BUT the shipping would be around $90 to China + $45 return shipping.
I did not think it would be worth the expense and the trouble since I could buy a used one for the same price or not much more. I am not handy with electronics and a soldering iron, but my guess is that it is just a resistor or two.
It seems that David is no longer involved with Little Dot and that it was taken over by the designer Sword Yang, but I am not sure of this information.
If you can find somebody local to repair it it may be worth it; otherwise it may be time for new and better things....
BTW, just saw on eBay a new MKII for $140 shipped:
https://www.ebay.com/itm/Little-Dot...774308?hash=item5d7d8432e4:g:RZcAAOSwQola-dEf
PS: I never got to repair my MKIII - it is for sale as is if somebody is interested.


----------



## Ggroch

As of last year, Sword Lang's Email Address was: little_dot@vip.163.com

He indicated as mentioned above that David was no longer involved with Little Dot.


----------



## doordie97

mordy said:


> Hi d97,
> I empathize with you - it is a terrible feeling when your beloved amps blows up. This is what happened to my Little Dot MKIII two years ago when I used a faulty adapter. One channel went dead after a puff of acrid smoke. All four tubes light up but the right channel is dead.
> I contacted David Zhe Zhe of Little Dot. The repair would cost $20-30 depending of what the problem was, BUT the shipping would be around $90 to China + $45 return shipping.
> I did not think it would be worth the expense and the trouble since I could buy a used one for the same price or not much more. I am not handy with electronics and a soldering iron, but my guess is that it is just a resistor or two.
> ...


Hey, thanks for the info. I’m living in MALAYSIA so shipping my actually be cheaper  anyway just contacted sword and awaiting his reply


----------



## mordy

doordie97 said:


> Hey, thanks for the info. I’m living in MALAYSIA so shipping my actually be cheaper  anyway just contacted sword and awaiting his reply


Good to hear - good luck!


----------



## willne1 (Jun 16, 2018)

Hey guys, I have been learning a lot about tubes from this thread and I really appreciate it. Can someone tell me if this tube on the right looks like a legitimate Mullard? Personally I think the tube on the left is legit but the one on the right I have my doubts about. It has one row of numbers etched in it whereas the one on the left has two, check out the plates.


----------



## HungryPanda

These are the Mullards I have


----------



## gibosi

willne1 said:


> Hey guys, I have been learning a lot about tubes from this thread and I really appreciate it. Can someone tell me if this tube on the right looks like a legitimate Mullard? Personally I think the tube on the left is legit but the one on the right I have my doubts about. It has one row of numbers etched in it whereas the one on the left has two, check out the plates.



I assume these are M8100 / 6AK5W? These tubes are not worth enough money for anyone to go to the trouble to make fakes. Rather, it is likely that they were made at different times, and this would explain why the tube on the right has extra bracing at the plate/mica junction while the other does not.


----------



## willne1

Thanks for the response gibosi, they are indeed 6ak5w. So if you are correct do you think they would sound close enough to each other that it would not be an issue? the tube on the right after closer inspection (now that it's a sunny day) appears to have the bottom row of etching warn off so it's unreadable. But the top row is definitely numbered 590.


----------



## gibosi

I assume that they both have rectangular getter holders (can't make out the construction above the top mica on the right tube, but the extra bracing suggests it is the oldest of the two), so both were likely manufactured in the 1950's. So yes, I would think that they were manufactured close enough in time to sound about the same.

On the other hand, I have a pair labeled CV4010 manufactured in the 1980's, some thirty years later, and I am much less confident that these would sound the same as yours.


----------



## willne1

Both of my tubes have the rectangular getter, I saw some of those tubes you have pictured above on ebay and also the RTC labeled Mullard tubes. I was thinking about getting one or the other but I was searching on here and can't really find anything about there sound. Anyhow, I feel a little better about the two we're talking about in my post so thanks for your help on that.


----------



## superdux

Hi,

i bought a violectric v200 recently and wondered if i could use my ldmkiii as a preamp with it?


----------



## mordy

superdux said:


> Hi,
> 
> i bought a violectric v200 recently and wondered if i could use my ldmkiii as a preamp with it?


Hi Superdux,
From the little I know, people who fed one preamp into another one ended up with an exaggerated unpleasant sound, but that was two tube preamps.
You could try and see if you like it with your setup.


----------



## WilliamLeonhart

superdux said:


> Hi,
> 
> i bought a violectric v200 recently and wondered if i could use my ldmkiii as a preamp with it?





mordy said:


> Hi Superdux,
> From the little I know, people who fed one preamp into another one ended up with an exaggerated unpleasant sound, but that was two tube preamps.
> You could try and see if you like it with your setup.


Sorry it took me 1 month to write this... The LD MK3 will serve as a preamp just fine. I used the MK4 SE to preamp my power speakers and the result was a surprise gain in clarity (crazy, right?).

How much distortion you'll have depends on how you set the volume on each amp. But, as @mordy said, the general rule of thumb is don't ever have 2 amps (pre + power) in your system. Once I just used my Aune T1 (which was DAC > tube buffer) with my Little Dot and it sounds really crapty. Too much of a good thing is never a good thing.


----------



## WilliamLeonhart

Guys I have something to ask... For the past year my tube collection has practically shrunk to: GE JAN 5654W, EI Yugo 6hm5 (tall bottle) and Voskhod 6zh1p EV (rocket logo on the box). Right now I feel like there's not much to try any more. I liked the Mullard 8100's warmth, but the cost really didn't make too much sense. Siemens 6ak5 practically sound the same. I had RCA and Brimar, nothing special I could tell. 
Of the ones I have left, I liked the GE JAN's "sharp-ish" sound, which make them very good for Rock. EI Yugo are like, honey-sweet, perfect for softer music. Voskhod sort of in between, tubey-neutral, all-around good for everything.

What should I go next? I noticed the C3g years ago, but budget would be a problem. Among the cheaper driver tubes, what would bring something new to the table? I'm in the US so I'll pick up some tubes before going home, and I hope to make a decision soon. Otherwise I'll just stash up more GE JAN, El Yugo and Voskhods.


----------



## mordy

WilliamLeonhart said:


> Guys I have something to ask... For the past year my tube collection has practically shrunk to: GE JAN 5654W, EI Yugo 6hm5 (tall bottle) and Voskhod 6zh1p EV (rocket logo on the box). Right now I feel like there's not much to try any more. I liked the Mullard 8100's warmth, but the cost really didn't make too much sense. Siemens 6ak5 practically sound the same. I had RCA and Brimar, nothing special I could tell.
> Of the ones I have left, I liked the GE JAN's "sharp-ish" sound, which make them very good for Rock. EI Yugo are like, honey-sweet, perfect for softer music. Voskhod sort of in between, tubey-neutral, all-around good for everything.
> 
> What should I go next? I noticed the C3g years ago, but budget would be a problem. Among the cheaper driver tubes, what would bring something new to the table? I'm in the US so I'll pick up some tubes before going home, and I hope to make a decision soon. Otherwise I'll just stash up more GE JAN, El Yugo and Voskhods.


Hi WL,
You already have the best drivers and I don’t think that you will gain significantly with the C3g, not to speak about the cost of the tubes and the adapters.
The next upgrade would be a different amp, but that is a whole other story.


----------



## JKWiig

Hello guys  I have been a lurker for many years and I have a Little Dot MKIII that I use as a pre-amp which is also a superb use for the LD 

I run the Military spec Mullard 4015 EF92 driver tubes and a pair of Sovtek 6H30P-EV power tubes

I have been using two solid state D amps in vertical bi-amping mode on a set of XTZ 99.25`s Now I upgraded to a Naim NAP250 Clone amp and started tube rolling again 
I have been happy with this setup for many years now. But the new amp has a different soundscape that needs some tweaking.

I noticed the C3G upgrade with adapters and the 6SN7 power tubes with adapters. I have removed my brass rings today and I have ordered adapters for both power and drivers.

So I have some questions for you guys.

1. It is basically the same what C3G`s I get since only Lorentz & Siemens made the C3G`s? And the jumpers need to be in EF95 mode? An eBay seller from Germany has some brand new Siemens that I am considering.
2. For power tubes, some Tung-Sol reissue 6SN7GTB should be good or a couple of Sylvania 6SN7GTB?

Thanks :3


----------



## gibosi

JKWiig said:


> Hello guys  I have been a lurker for many years and I have a Little Dot MKIII that I use as a pre-amp which is also a superb use for the LD
> 
> I run the Military spec Mullard 4015 EF92 driver tubes and a pair of Sovtek 6H30P-EV power tubes
> 
> ...



To the best of my knowledge, If the black cans are shiny with white silk screened text and graphics, Siemens made them, no matter the brand -- Siemens, Lorens, Valvo or Telefunken. Most of these tubes were manufactured in the 1970's. If the cans are flat-black with embossed text and graphics, then they were manufactured by the company whose name appears on the tube. These tubes were typically manufactured in the 1960's and earlier.

And yes, use the EF95 mode.

As I had an LD1+, that is it had no power tubes, I will defer to others regarding the various reissues versus old-stock 6SN7.....


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## mordy

gibosi said:


> To the best of my knowledge, If the black cans are shiny with white silk screened text and graphics, Siemens made them, no matter the brand -- Siemens, Lorens, Valvo or Telefunken. Most of these tubes were manufactured in the 1970's. If the cans are flat-black with embossed text and graphics, then they were manufactured by the company whose name appears on the tube. These tubes were typically manufactured in the 1960's and earlier.
> 
> And yes, use the EF95 mode.
> 
> As I had an LD1+, that is it had no power tubes, I will defer to others regarding the various reissues versus old-stock 6SN7.....


Hi JKW,
I have the Tung Sol reissue 6SN7GTB tubes, and IMHO you are better off to buy an inexpensive pair of old production 6SN7 tubes instead.
The problem that all tube equipment manufacturers are facing today is that there are very few factories left, and to be able to have a stable supply of tubes you have to go to Russia or China for re-issues (or to Russia for large quantities of older tubes).
For an individual that just needs a pair or two it is not too difficult to find old tubes.
I found the 6SN7 power tubes better in the LD MKIII than the 6N6 variants.
I also have the C3g tubes which should work just fine.
Good luck!


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## JKWiig (Jul 23, 2018)

Thank you very much for your responses.

I will upgrade my power with adapters and 6SN7 tubes and a pair of matched tall Ei 6HM5`s for drivers for now and I have the option to run C3g`s when I find a good bargain. I have bought the necessary adapters, though so I have them.

For my 6SN7 options, I got some matched Shuguang Chinese 6N8P (metal bottoms) and a pair of Russian Foton 6N8S. Looking forward to trying them out when they arrive here in Norway


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## mordy

JKWiig said:


> Thank you very much for your responses.
> 
> I will upgrade my power with adapters and 6SN7 tubes and a pair of matched tall Ei 6HM5`s for drivers for now and I have the option to run C3g`s when I find a good bargain. I have bought the necessary adapters, though so I have them.
> 
> For my 6SN7 options, I got some matched Shuguang Chinese 6N8P (metal bottoms) and a pair of Russian Foton 6N8S. Looking forward to trying them out when they arrive here in Norway


Lycka till! I was born in Sweden but left over 50 years ago men jag talar fortfarande flytande svenska.


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## gulakpii

I'm also on Valvo C3g's on my LD mk4.   
For the "power tubes", I tried both the Shuguang 6N6P and the Foton 6N8S before.  These were good, but I found the PSVANE UK-6SN7 are better (did somebody said they were also made by Shuguang?).
They are silky smooth,especially on the highs, on my HD-650, but all these are not for my low-Z AKG's.  The 6SN7 family probably will not work well with the low-Z cans.

One of the many reasons I like the PSVANE UK-6SN7 is, probably because of the "coke-bottle" shape of the tubes!  Seeing them glow in dimmed light is a treat!

My special thanks to the 2 gentlemen above (among many others in this forum), who shared their experience with us!


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## JKWiig (Jul 25, 2018)

Since I use my LD as pre-amp and not very much for cans I go by the guidelines and general advice of the can people but have to tweak a little for my setup. I will, however, try the PSVanes later when I have some moneys for more tubes. Just starting the 6SN7 & C3g journey. I might even be so bold as to go full external heater and 6AS7 when I can muster up the nerve.

These are the Shuguang Chinese 6N8P I want to try. Reviews sound promising.


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## mordy

JKWiig said:


> Since I use my LD as pre-amp and not very much for cans I go by the guidelines and general advice of the can people but have to tweak a little for my setup. I will, however, try the PSVanes later when I have some moneys for more tubes. Just starting the 6SN7 & C3g journey. I might even be so bold as to go full external heater and 6AS7 when I can muster up the nerve.
> 
> These are the Shuguang Chinese 6N8P I want to try. Reviews sound promising.


Hi JKW,
IMHO, once you have upgraded the drivers to the Ei 6HM5/C3g and the power tubes to the 6SN7 family, you have basically reached the limits how much you can upgrade the Little Dot MKIII/IV amps.
I am not knowledgeable about the electric circuitry in the LD amps, but it is very possible that using external power and 2.5A power tubes (6AS7/6080), the resistors may be overloaded and the amp may be fried. However, I defer to others since I do not know enough about this.
Once you reach the top level of performance in the LD it is logical to upgrade to a 
different amp, but it will cost more....


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## JKWiig (Jul 25, 2018)

No worries 

I can call it a day after this. I just need to find a combination I like with 6SN7`s. I am a little skeptical running external voltage for the heaters in 6AS7/6080`s anyways 

And since I am using the MKIII as a pre-amp I have many other options to tweak the amplification stage anyways. I must say, though, that the tubes have a very significant impact on soundscape even used as a pre-amp only. I am so in love with this little thing. I have had it for 8 years now and it is still going strong.

I am betting this upgrade will keep me more than happy for another 8 

EDIT: I am tremendously grateful to the pioneers on this forum that have worked very hard to bring these upgrades and modifications out to the rest of us. You guys ROCK!


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## mordy

JKWiig said:


> No worries
> 
> I can call it a day after this. I just need to find a combination I like with 6SN7`s. I am a little skeptical running external voltage for the heaters in 6AS7/6080`s anyways
> 
> ...





JKWiig said:


> No worries
> 
> I can call it a day after this. I just need to find a combination I like with 6SN7`s. I am a little skeptical running external voltage for the heaters in 6AS7/6080`s anyways
> 
> ...


I used my MKIII almost exclusively as a preamp with a speaker system, and this little amp makes a very big difference - enjoy!
In terms of external power I used an inexpensive voltage regulator with an old PC power supply in order to be able to use tubes of different voltage such as 12V and 8V tubes. Many times such tubes are the same as their 6V equivalents but much cheaper.


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## lumohomo06

New to little dot, which tube is a good fit for Grados? Appreciate it.


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## Tony51 (Jul 25, 2018)

lumohomo06 said:


> New to little dot, which tube is a good fit for Grados? Appreciate it.


What Grados you have? I have the sr60e, sr325e and the RS2E. All three sound very good with my LDmk2 with the power tubes Russian made called the Super Tube Sovtek 6H30pi, (Cryoset certified

 )these are the most powerful of all my tube rolling. As for the driver tubes, I finally settled with the Mullard M8161/cv4015 hard to find on eBay. So if you want to spare yourself the grief of tube rolling, find the above. The super tubes are found between 50-75 dollars. The Mullard we're much cheaper at about 30 dollars. You may find yourself setting the LD on medium gain since the Grados are so easily driven. I keep mine on high gain since my LDMK2 is more dedicated to my Sennheiser hd600 and my Beyerdynamic dt1990 pro.
A close second best driver tubed are the jan5654w by GE, found cheap on eBay or 20 dollars on Amazon which I have on my nobsound bass/ treble preAmp connected to my LDMK2 for that extra bass when needed.
The Mullard outshined the GE by a tad in dynamics otherwise a pretty close tie.
With these Mullard (taller tubes) the family changes from ef95 to the ef92 so you have to put the jumpers inside the case on the board pins reading ef92 or there will be no sound.
Tony


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## lumohomo06

Tony51 said:


> What Grados you have? I have the sr60e, sr325e and the RS2E. All three sound very good with my LDmk2 with the power tubes Russian made called the Super Tube Sovtek 6H30pi, (Cryoset certified )these are the most powerful of all my tube rolling. As for the driver tubes, I finally settled with the Mullard M8161/cv4015 hard to find on eBay. So if you want to spare yourself the grief of tube rolling, find the above. The super tubes are found between 50-75 dollars. The Mullard we're much cheaper at about 30 dollars. You may find yourself setting the LD on medium gain since the Grados are so easily driven. I keep mine on high gain since my LDMK2 is more dedicated to my Sennheiser hd600 and my Beyerdynamic dt1990 pro.
> A close second best driver tubed are the jan5654w by GE, found cheap on eBay or 20 dollars on Amazon which I have on my nobsound bass/ treble preAmp connected to my LDMK2 for that extra bass when needed.
> The Mullard outshined the GE by a tad in dynamics otherwise a pretty close tie.
> With these Mullard (taller tubes) the family changes from ef95 to the ef92 so you have to put the jumpers inside the case on the board pins reading ef92 or there will be no sound.
> Tony



Thank you, Sir.  My LD 1 will arrive this Friday, I will try the stock tube and later I will try your recommendations. 
I have SR60, 125, 325. PS500. 
I really like the RS2e, let me know if you want to get rid of yours. Thanks.


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## Tony51

lumohomo06 said:


> Thank you, Sir.  My LD 1 will arrive this Friday, I will try the stock tube and later I will try your recommendations.
> I have SR60, 125, 325. PS500.
> I really like the RS2e, let me know if you want to get rid of yours. Thanks.



Wait, I thought you had the LD Mk2, you typed LD 1? Is this correct? If so, you don't have power tubes to change since it's a hybrid not a true class A amp. If that is the case you only need to change the driver tubes (2). I thought you had the 4 valve LDMK2.

P.s the stock tubes suck pretty bad and distort even after burn in. Anyway nice Grado set up you have. Not selling my Grados, but I am selling my Hifiman Edition S and my Sennheiser hd579 which I just don't use. Both in like new condition.
Tony


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## lumohomo06

Yes, I bought the 
Little Dot I+ 6JI X2 Tube standard Hybrid Headphone Tube Amplifier, with stock tube only.  Do you think LD MK2 will be better than this? 

The RS2e is really good, I listened one time， really impressed with the vocal, and really non-fatiguing.  Compared to RS1e, RS2e is my type. 
Have you listened to RS2i, RS1i, or RS1? Which one is similar to RS2e? 

Thanks!


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## Tony51

lumohomo06 said:


> Yes, I bought the
> Little Dot I+ 6JI X2 Tube standard Hybrid Headphone Tube Amplifier, with stock tube only.  Do you think LD MK2 will be better than this?
> 
> The RS2e is really good, I listened one time， really impressed with the vocal, and really non-fatiguing.  Compared to RS1e, RS2e is my type.
> ...



Yes sir, if you want a true analog tube experience, I've would have purchased the LD MK2 since its the real deal, however the LD 1 should sound pretty good and has 800mW at 32 ohms which will drive your Grados to deafening level. But you are not going to get the full analog experience since you will not have tubes supplying the power.

As to the Grados RS2i, RS1i and RS1, i have not listened to them, only the three i have mentioned before. The RS2e are the most analog sounding of the bunch. My sr325e are bright but man do they sparkle and sound pretty darn good on the LDmk2 and even better on Solid State amps. I have swapped the original pads on my Grados to the Earzonk G cushions that supplies a bit of more bass from the get go.


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## lumohomo06

Thanks for the detailed explanation.  I did not know that little dot 1+ is not a full tube amp.  
Have you used any solid state amp that is a good pair with Grados? Thanks.


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## Tony51 (Jul 27, 2018)

lumohomo06 said:


> Thanks for the detailed explanation.  I did not know that little dot 1+ is not a full tube amp.
> Have you used any solid state amp that is a good pair with Grados? Thanks.


A solid state for desktop I don't have as I am more about portability than anything else. However, I just sold my Emotiva A100 which sounded very very clean, the downside was that the A100 lacked a little bass so the Schiit Loki EQ was a very good welcome to pair with the Emotiva. Since I barely used it, I sold it. Now that was my desktop, if that is what you're after, the combo mentioned is excellent but an over kill for Grados since they are so easily driven. This combo would set you back 229.00 for the Emotiva n 165.00 for the Schiit Loki EQ.

Now for portability which is what I use 99% of the times. I'm using my Sony Walkman ZX2 paired with the Fiio E12 portable amp that has a bass boost on the fly. The Grados sound great in this combo.
My other combo is my Fiio X7mk2 paired with my other Fiio A5 portable amp with bass boost.
The Sony combo supplies a more analog sound than the Fiio X7mk2 combo.
I don't know what you use as your music source but sound is different between devices.
The Fiio X7mk2 has a hump in the 2k-4khz region while the Sony is the reverse in that region. I love both signatures it supplies.
I also have the Little Bear 4 portable tube amp which I'm testing as we speak and sounds pretty darn good but can't tell you as to the best paring yet because I have not tested with all my headphones.
On a side note, I have another tube amp in route from China which I want to try out and if I like it, I might be selling my LDMK2 with the great tubes it had installed. It's only because my LD Mk2 is almost exclusively used for my Sennheiser hd600 and I have it on high gain and for the Grados it should be set on medium to low gain so that it would sound best and I don't want to open the case up to set the switch to low Everytime I grad a headphone that is easily driven, so I have it set to high gain at all times. If you get yours I'd set it to med-low gain and see which settings give you the most balanced sound and leave it there. The LD Mk2 sounds very very good.
Tony


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## lumohomo06

Damn it, I got my MK 1+ today, and to my surprise, it is 220 V with UK plug. Amazon must be kidding with me. Sad day for me.


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## Tony51

lumohomo06 said:


> Damn it, I got my MK 1+ today, and to my surprise, it is 220 V with UK plug. Amazon must be kidding with me. Sad day for me.


That completely sucks.


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## Tony51

lumohomo06 said:


> Damn it, I got my MK 1+ today, and to my surprise, it is 220 V with UK plug. Amazon must be kidding with me. Sad day for me.



Another good set up is the Little Bear 4 portable amp paired with the Sony Walkman ZX2. Will test with the Fiio X7mk2 later.


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## lumohomo06

Ur RS2e looks shiny, awesome, did you mod this? 


Tony51 said:


> Another good set up is the Little Bear 4 portable amp paired with the Sony Walkman ZX2. Will test with the Fiio X7mk2 later.


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## Tony51 (Jul 28, 2018)

lumohomo06 said:


> Ur RS2e looks shiny, awesome, did you mod this?


Yes it has the gorgeous aluminum gimbals from rholupat in Indonesia. Also have three sets of pads, the L cushions for when I want over ear coverage, the g cushions by Earzonk when I want to hear music a little different but more bass, and the geekria flat pads for when I want details down my ear canal.
https://m.facebook.com/flx/warn/?u=...TuvK46Y_SfAxaE9YodlTpGoJBxTk2ncPPlsihR45ICje8


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## lumohomo06

Tony51 said:


> Yes it has the gorgeous aluminum gimbals from rholupat in Indonesia. Also have three sets of pads, the L cushions for when I want over ear coverage, the g cushions by Earzonk when I want to hear music a little different but more bass, and the geekria flat pads for when I want details down my ear canal.
> https://m.facebook.com/flx/warn/?u=http://rholupat.com/&h=AT37XvYJ76ARCFDb1oQI622P0dWlRL0K2LC5JYcnvBoKp8qWysgZa3_IOPjJMRUXVOa_NakqzqwC5GdO-kPNlxrP6vituUFmE3TuvK46Y_SfAxaE9YodlTpGoJBxTk2ncPPlsihR45ICje8



Wahh, You are having so much fun out of it.  Thanks for the link, will check it out.


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## Tony51

lumohomo06 said:


> Wahh, You are having so much fun out of it.  Thanks for the link, will check it out.


I did the same with the 325e, they also have the aluminum gimbals.


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## lumohomo06

I checked the website, the gimbals are out of stock, sad.


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## Tony51

lumohomo06 said:


> I checked the website, the gimbals are out of stock, sad.


Yup, he runs out super quick. However you can leave him a message to let you know when he makes some new ones and he will. I've purchased several times from him so even though you might get a flag from the website security, it's ok and legit. The gimbals in aluminum are very well made and gorgeous.
Tony


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## lumohomo06

Sir, does this work with little dot mk 3? Thanks. 

https://www.ebay.com/itm/M8161-EF92...e=STRK:MEBIDX:IT&_trksid=p2060353.m1438.l2649


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## Tony51

lumohomo06 said:


> Sir, does this work with little dot mk 3? Thanks.
> 
> https://www.ebay.com/itm/M8161-EF92-6065-CV4015-MULLARD-NOS/310391381072?ssPageName=STRK:MEBIDX:IT&_trksid=p2060353.m1438.l2649


They sure do buddy, those are my bad boys. A little hard to find but they are great. This one belongs to the Ef92 family not the Ef95.
Tony


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## lumohomo06

Oh, Can you please send me a link of the tubes you use? Any difference between Ef92 or Ef95? I have no clue. 
Also, there are two sets, one short, one long for the little dot, four tubes in total? Should I replace all of them?
Appreciate it.


----------



## Tony51

lumohomo06 said:


> Oh, Can you please send me a link of the tubes you use? Any difference between Ef92 or Ef95? I have no clue.
> Also, there are two sets, one short, one long for the little dot, four tubes in total? Should I replace all of them?
> Appreciate it.



The two shorter ones up front are the driver tubes, those you will replace for the Mullard cv4015 which are great tubes and they are a tad taller than the stock Chinese garbage the LD MK2 comes with. You will have to remove 4 screws from the body chassis on the LD to look into the board and you will see 3 pins on the left and 3 pins on the right, indication right and left channel. You will have to place the very small black pins on the side closest to the ef92 reading, do the same to the other channel. Ill tell you about the gain settings when we cross that bridge. 

The back Larger tubes are the power tubes and those are called the power tubes. The stock chinese power tubes are actually not bad but if you want a tad more power output and a finer sound, replace them for the Sovtek 6H30Pi which are the best ive found for my use. They are 55.00 for a match pair. You want a match pair. Its important.  Hit the link

https://www.ebay.com/itm/SOVTEK-Fac...tched+pair&_from=R40&rt=nc&_trksid=m570.l1313


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## lumohomo06

Thanks for the detailed info, now things are clearer to me.  I just bought a used MK 3 from eBay, will roll the tubes based on your suggestions. 
Thanks a million.


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## lumohomo06

I was going to use Little dot as a pre-amp, should I use the RCA output on the back and connected to another amp, Or should I use the little dot headphone output and use the 6.5mm to RCA and connect it the other amp? Thanks.


----------



## Tony51

lumohomo06 said:


> I was going to use Little dot as a pre-amp, should I use the RCA output on the back and connected to another amp, Or should I use the little dot headphone output and use the 6.5mm to RCA and connect it the other amp? Thanks.


I'm using mine as a stand alone, nothing is connected to it but the nobsNobs preAmp bass/treble.
However, you can use it both ways you mentioned. 
RCA out from the LDOT to the external amp rca in. This way it should function as a preAmp.
If you intend to use the amp of the LDot, RCA/3.5mm input to source, ie mp3 player.
If you get noise, try stand alone use to ensure it's not your tubes. Because connecting to other amps, preAmps and so forth can bring in static  or noise hum. Mine is dead silent. But I have never used it any other way. Are you using the LDot strictly with Grados? If so remember, you probably will have to switch to low or medium gain for best results. Forget using planar magnetic headphones, these work best on Solid amps.


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## lumohomo06

I see. Just found out how to change the gain. The tube amp is so much different from the solid amp. Really love the LD. 
Thank you for your time. 
Appreciate it.


----------



## TrollDragon

lumohomo06 said:


> I was going to use Little dot as a pre-amp, should I use the RCA output on the back and connected to another amp, Or should I use the little dot headphone output and use the 6.5mm to RCA and connect it the other amp? Thanks.



The Headphone Jack and Line out jacks on the Little Dots are connected to the same spot on the board inside.  You can use either one as it's the same connection.


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## lumohomo06

Very helpful, thanks a million.


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## lumohomo06

Anyone knows a nice and good tube shield cover for LD? Thanks.


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## cardoski

Thank you to the OP very helpful and inspiring to this greenhorn.


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## RyokoZekem (Aug 28, 2018)

I have been using my Little Dot Mk II for almost a year now and its still sounding great, although I recently upgraded the audio cable lines inside to 18 AWG which seems to have helped a lot with dynamic range and detail. Maybe its because of my cheapy DAC (Signtek Mini USB DAC) not being able to push detail through the smaller gauge cable, seeing I wouldn't normally expect any difference in basically a few inches of wire inside the case. I use Sennheiser 598HD headphones with Brainwaves Sheepskin pads.. (however that matters, although I'm slightly concerned it might not work well with the 6SN7).

I'm looking to buy 6SN7 to use on my amp but I'm not sure what adapter to buy. Also Mullard M8100 but I expect all Mullard M8100 sound similar.. I think? I see many different labels but the same manufacturing basically? Or should I skip above and just get C3g with adapter?
I've been using either 5654W Jan or 6HM5 with 6N6P Novosibirsk gold grid tubes. Little too bright for my ears, so I'm hoping to mellow that out, while bringing out some more bass and soundstage.


----------



## MIKELAP

RyokoZekem said:


> I have been using my Little Dot Mk II for almost a year now and its still sounding great, although I recently upgraded the audio cable lines inside to 18 AWG which seems to have helped a lot with dynamic range and detail. Maybe its because of my cheapy DAC (Signtek Mini USB DAC) not being able to push detail through the smaller gauge cable, seeing I wouldn't normally expect any difference in basically a few inches of wire inside the case. I use Sennheiser 598HD headphones with Brainwaves Sheepskin pads.. (however that matters, although I'm slightly concerned it might not work well with the 6SN7).
> 
> I'm looking to buy 6SN7 to use on my amp but I'm not sure what adapter to buy. Also Mullard M8100 but I expect all Mullard M8100 sound similar.. I think? I see many different labels but the same manufacturing basically? Or should I skip above and just get C3m with adapter?
> I've been using either 5654W Jan or 6HM5 with 6N6P Novosibirsk gold grid tubes. Little too bright for my ears, so I'm hoping to mellow that out, while bringing out some more bass and soundstage.


This adapter i used on my Littledot MK3  6SN7 to 6CG7 https://www.ebay.ca/itm/1pc-Gold-pl...946751?hash=item2ed371ceff:g:J2oAAOSwQjNW-kSg


----------



## WilliamLeonhart

RyokoZekem said:


> I have been using my Little Dot Mk II for almost a year now and its still sounding great, although I recently upgraded the audio cable lines inside to 18 AWG which seems to have helped a lot with dynamic range and detail. Maybe its because of my cheapy DAC (Signtek Mini USB DAC) not being able to push detail through the smaller gauge cable, seeing I wouldn't normally expect any difference in basically a few inches of wire inside the case. I use Sennheiser 598HD headphones with Brainwaves Sheepskin pads.. (however that matters, although I'm slightly concerned it might not work well with the 6SN7).
> 
> I'm looking to buy 6SN7 to use on my amp but I'm not sure what adapter to buy. Also Mullard M8100 but I expect all Mullard M8100 sound similar.. I think? I see many different labels but the same manufacturing basically? Or should I skip above and just get C3m with adapter?
> I've been using either 5654W Jan or 6HM5 with 6N6P Novosibirsk gold grid tubes. Little too bright for my ears, so I'm hoping to mellow that out, while bringing out some more bass and soundstage.


Hmm 5654W and 6hm5 are like 2 different ends of the spectrum for me (5654w energetic, 6hm5 mellowed)... That said I've only used them with my I+.


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## RyokoZekem (Aug 28, 2018)

MIKELAP said:


> This adapter i used on my Littledot MK3  6SN7 to 6CG7 https://www.ebay.ca/itm/1pc-Gold-pl...946751?hash=item2ed371ceff:g:J2oAAOSwQjNW-kSg


Does the MK III use the same kind of power tubes as the Mk II? Edit: nevermind, answered my own question, thanks a lot for the link. I will buy that. Now to find some cheap 6SN7 to try along side some Mullard M8100s. 



WilliamLeonhart said:


> Hmm 5654W and 6hm5 are like 2 different ends of the spectrum for me (5654w energetic, 6hm5 mellowed)... That said I've only used them with my I+.


Yeah I used the Little Dot I+ before this amp with the LT1364 as the OPAMP with those very tubes. It behaved very much like you said in that amp. 6HM5 was very natural and had a large sound stage and the bass was pretty slamming sometimes, whereas 5654w sounded sweet and was great for metal and the bass was pretty clean.  My little dot I+ lost its left channel, not sure how but I think one of the mosfet died. I decided rather than fix it, I'd just move on.


----------



## AthenaZephyrian

I've tried stock, GE JAN5654W, and Voskhod 6ZH1P-EV as far as tubes are concerned, and stock, AD823, and LT1364 for op-amps.  I was gonna try the AD8656, but connected it backwards absentmindedly, and literally fried it.  It started smoking.  

The two tubes worth discussing sound very similar, but the 5654 is a bit more mellow and warm, while the Voskhod is a bit clearer and more detailed.  The AD823 is very, very detailed, clear, and pretty spacious but has some distortion problems with high-amperage loads at higher volume (15 mA max output, compared to the usual ~40 mA), while the LT1364 is a bit more intimate, warm, and slightly smoother.  There's really litle point getting a Little Dot I+ unless you roll the tubes _and the op-amps_.  The stock op-amp congests the whole thing, and really decreases sound quality, easily as much as the stock tubes do.  WIth both switched... great, great sound for the money.


----------



## AthenaZephyrian

RyokoZekem said:


> I recently upgraded the audio cable lines inside to 18 AWG which seems to have helped a lot with dynamic range and detail.



Have you also tried rolling op-amps?  How big a difference did this make in comparison?


----------



## gibosi

AthenaZephyrian said:


> There's really litle point getting a Little Dot I+ unless you roll the tubes _and the op-amps_. The stock op-amp congests the whole thing, and really decreases sound quality, easily as much as the stock tubes do. WIth both switched... great, great sound for the money.



I agree wholeheartedly!


----------



## AthenaZephyrian

gibosi said:


> I agree wholeheartedly!


Another great sound for the money is the SMSL M6.  The amp is quite decent, but not quite as quality as the O2/Magni.  When you pair its internal DAC with a pimped Little Dot though.....hoooo boy.  Very nice.  It's a sweet (not aurally--sweet as in awesome!) DAC. 

Some Little Dot pron for your viewing pleasure :


----------



## gibosi

Great pics! Especially with Halloween just around the corner.

My Little "Monster" Dot. 

Apologies to those who have seen this before....     Set up to run a pair of C3g or one 9-pin double triode, with Muses 02 inside.


----------



## AthenaZephyrian (Aug 29, 2018)

gibosi said:


> Great pics! Especially with Halloween just around the corner.
> 
> My Little "Monster" Dot.
> 
> Apologies to those who have seen this before....     Set up to run a pair of C3g or one 9-pin double triode, with Muses 02 inside.



You're a bloody madlad.  Here, take your gold.  Oh, this isn't reddit, sorry.  We need a head-fi silver... *NOW WITH FREE HEAD-FI GOLD!!1!!1*


----------



## RyokoZekem

@AthenaZephyrian
Well agreed but my Little Dot I+ is in my closet graveyard of old PC's and such now. I could probably repair it with some effort but I like my Little Dot MK II just fine. I have been looking at SMSL Sanskrit 6th (DAC only), I might get that for a DAC solution. Very nice looking Little Dot. I loved my Little Dot I+ to death, and yep the LT1364 really were a nice mix with 5654W JAN. I had the most success when my old soundcard (Auzentech Prelude:Also KIA) had the LT1364 in it too, so.. LT1364x2 + 5654W JAN = very airy and super sweet. Made me cry when I listened to Amazing Grace. I kinda miss it even though my current setup has its own niceness. I can just never replicate any setup I have had in the past. Equalizers just don't do it. My current goal has been pretty much to tame the highs and make the vocals sweet with a soupy texture. If that makes any sense, I just want to listen to hymnals without pain. 

@gibosi That looks like a lot of fun.


----------



## gibosi

RyokoZekem said:


> @gibosi That looks like a lot of fun.



For sure, it was a lot of fun. But my Little Monster is resting nicely in it's box now. I have moved on to a Glenn OTL, and I am having lots of fun with it too.


----------



## Trogdor420

I have recently had a lot of NOS 6AJ5 tubes fall into my lap.  Would anybody be interested in purchasing a set?


----------



## Johnybuchar

BTW I have put 5654W Joint Army Navy Sylvania (black plates) into my LT3 and I am very satisfied with them. Frequency response a little bit into V-shape but listening is very airy with punchy bass without any fatiguing feedback . Overall Impression is very positive and high position in my tube-ladder around Mullard 8100, Tesla 6F32 . Highly recommend try them.


----------



## Astonish

Any good places to buy that are in the Usa?


----------



## Tony51

Astonish said:


> Any good places to buy that are in the Usa?


TubeDepot
The TubeStore

Tony


----------



## Astonish

Tony51 said:


> TubeDepot
> The TubeStore
> 
> Tony



Thanks Tony


----------



## Tony51

Astonish said:


> Thanks Tony


Your welcome, I just purchased 4 Tung-Sol 6v6GT power tubes
2 Gold Lion 6922 (6N1)w/gold grids
1 Jan5670w GE (6N3) for my newly purchased amplifier, the Audioromy 6v6 12wattx2 amplifier with headphone jack. Dave at the tubestore adviced me that the above tubes would be an excellent upgrade to my headphone amp and he was so right. The sound id fantastic.
Tony


----------



## BreadFi

Unfortunately I've recently bought a pair of DT770 for work/portable use and am now spoiled for sub bass in a headphone.

My old DT880 250ohm/LD Mk3 home arrangement still sounds fantastic with a very pleasant low end, but I'm wondering if there's a valve that will bring out that <80hz range specifically (understanding it's probably more down to the 880's enclosure design).

I've ordered a pair of Mullard CV4010/M8100 based on opinions here, but not sure if its just going to be more dark, mid-bassy/boomy compared to what I have.

Which is my second question.
Can anyone identify this 5654?
I bought a new set years ago, but these might even be the stock ones.
No other labelling on them other than 5654 USA and the logo that looks like a Z/Sig out of dots (may just be worn).

Cheers.


----------



## gibosi

The sandblasted block lettering and dots suggest that GE manufactured this tube. The dot pattern represents the date of manufacture.

http://antiqueradios.com/forums/viewtopic.php?f=19&t=230932


----------



## TrollDragon

BreadFi said:


> My old DT880 250ohm/LD Mk3 home arrangement still sounds fantastic with a very pleasant low end, but I'm wondering if there's a valve that will bring out that <80hz range specifically (understanding it's probably more down to the 880's enclosure design).


There isn't a tube out there that will bring out the sub bass in a pair of DT880's, I use them on my LD MKIV with the 6HM5 drivers and it is what it is. When I want more bass I fire up the Ultrasone HFI-780's on the solid state amp or pull out the JVC 77x's for even more thump.


----------



## BreadFi

Thanks. Having a good listen last night I really do like how the bass is presented on them with the current 5654 - better than out of a solid state to my ears (and now I can just pull out the DT770s/SS when I want sub).
Sweetening the mids/hi's on the DT770 might be a better goal.


----------



## TrollDragon

There might be some mods in Bill-P's thread that would help .
https://www.head-fi.org/threads/bil...diary-including-sibilance-elimination.707992/


----------



## BreadFi

Received the Mullards yesterday but prefer the GE set I had. GE's noticably punchier bass and thicker mids (sweeter treble to my ears too). Mullard, counter to the first page description is brighter and maybe a little more upper mid clarity and openness - nice on acoustic tracks, but the GE's a better rock tube with the 880s IMO - just nails high gain guitars and hefty bass.
I reckon the Mullard M8100 would fit Sennheisers better.


----------



## jimtaylor

Hello!

I just got a Little Dot Mk III which is my first Tube Amp. I'm stoked to give some tube rolling a try as I already love the amp just straight out of the box. The sound compared to my solid state amp is just so different. Anyhow, I've tried to read as much of this thread as possible but a lot of it is going over my head. So I hope nobody minds that I am going to ask some simple, stupid questions and recommendations. To pair with my Little Dot Mk III I've already purchased the following:

2 x 9pin tube testing saver (I read enough times on here that these are good to have if you are going to be tube rolling)
2 x 7pin tube testing saver

Driver Tubes:
Matched pair of Voshkod 6ZH1P-EV (Still waiting for this)
2 x Matched pair of GE JAN 5654W (It was a better deal to get a set of 4)

Any other recommendations? I am open to suggestions and would like to start with 4 sets to get a baseline going. 

Power Tubes:
2 x Matched pairs of 6N6P power tubes (They came with the amp from the seller I purchased it from)

Here is where I get a little more confused on being able to determine what tube's I can use. I've also read conflicting advice on how worth it is to role power tubes? So any recommendations? And what would be needed to use that recommendation? I read through a number of the power amp reviews on this thread but started getting confused at some of the modifications required. I don't mind having to buy tube converter adapters if you can point me in the right direction but I don't feel confident enough at this point to take out my soldering iron and start going nuts.... not yet at least.


----------



## MIKELAP

jimtaylor said:


> Hello!
> 
> I just got a Little Dot Mk III which is my first Tube Amp. I'm stoked to give some tube rolling a try as I already love the amp just straight out of the box. The sound compared to my solid state amp is just so different. Anyhow, I've tried to read as much of this thread as possible but a lot of it is going over my head. So I hope nobody minds that I am going to ask some simple, stupid questions and recommendations. To pair with my Little Dot Mk III I've already purchased the following:
> 
> ...


                                                                                                                                                                                                                                                                                                                                       Hi first of all you dont need matched pairs for the MK3 this will save you money . Well regarded power tubes and not to expensive are 6n6pIR tubes https://www.ebay.ca/sch/i.html?_osa...RC0.A0.H0.X6n6p+ir.TRS0&_nkw=6n6p+ir&_sacat=0         For driver tubes theres the 6HM5 yugo TALL BOTTLE  might get them for $5.00 EACH   https://www.ebay.ca/itm/6HM5-6HA5-E...467071?hash=item460dd0523f:g:UJ0AAOxyyF5RN3~H  .Also what i liked as power tubes were the 6SN7 OCTALS but you need a pair of adapters for them and probably a pair of socket savers for the adapters to clear the rings on the amp these are good quality  adapters https://www.ebay.ca/itm/1pc-Gold-pl...946751?hash=item2ed371ceff:g:J2oAAOSwQjNW-kSg  That will keep you busy .Have fun


----------



## jimtaylor

MIKELAP said:


> Hi first of all you dont need matched pairs for the MK3 this will save you money . Well regarded power tubes and not to expensive are 6n6pIR tubes https://www.ebay.ca/sch/i.html?_osa...RC0.A0.H0.X6n6p+ir.TRS0&_nkw=6n6p+ir&_sacat=0         For driver tubes theres the 6HM5 yugo TALL BOTTLE  might get them for $5.00 EACH   https://www.ebay.ca/itm/6HM5-6HA5-E...467071?hash=item460dd0523f:g:UJ0AAOxyyF5RN3~H  .Also what i liked as power tubes were the 6SN7 OCTALS but you need a pair of adapters for them and probably a pair of socket savers for the adapters to clear the rings on the amp these are good quality  adapters https://www.ebay.ca/itm/1pc-Gold-pl...946751?hash=item2ed371ceff:g:J2oAAOSwQjNW-kSg  That will keep you busy .Have fun




Thank you so much for all the input! I read that the Little Dot Mk III doesn't need matched, is there a reason for that?


----------



## Whelkie D

jimtaylor said:


> Thank you so much for all the input! I read that the Little Dot Mk III doesn't need matched, is there a reason for that?


You've already bought some very decent tubes there. Another few to try are the Yugoslavian 6HM5 (tall) and for a really warm sound some Mullard 8100. I found that changing the power tubes DOES alter the sound by about 20%. The power tubes you already have are good ones (6N6P). If you decide to alter the jumper pins inside the amp so that you can use EF91/EF92 family of tubes you might want to try some old Osram Z77 but this is something to do in the future. Happy rolling!


----------



## TrollDragon

jimtaylor said:


> Thank you so much for all the input! I read that the Little Dot Mk III doesn't need matched, is there a reason for that?


Little dot amps (MK2/3/4) do not use "power tubes",  calling the output tubes that is a bit of a misnomer as the amplifier is just a preamp. Matched tubes are required for push pull amplifiers that output to speakers. You need to match the tubes so they have the same plate current, unmatched tubes with one tube drawing more current will wear that tube out earlier than the other.

Matching of preamp tubes is a way for sellers to squeeze more money out of you.


----------



## jimtaylor

TrollDragon said:


> Little dot amps (MK2/3/4) do not use "power tubes",  calling the output tubes that is a bit of a misnomer as the amplifier is just a preamp. Matched tubes are required for push pull amplifiers that output to speakers. You need to match the tubes so they have the same plate current, unmatched tubes with one tube drawing more current will wear that tube out earlier than the other.
> 
> Matching of preamp tubes is a way for sellers to squeeze more money out of you.




Thanks for the information. I won't waste my money then.


----------



## jimtaylor (Sep 22, 2018)

Hi, another question. I got a pair of 1960's made Sylvania 6ah6wa's for a good price and was curious about how to be able to plug them into the little dot? Can anyone point me to where in the thread there is a guide to be able to convert it the Little Dot sockets to be able to use them?


----------



## Scutey

jimtaylor said:


> Hi, another question. I got a pair of 1960's made Sylvania 6ah6wa's for a good price and was curious about how to be able to plug them into the little dot? Can anyone point me to where in the thread there is a guide to be able to convert it the Little Dot sockets to be able to use them?


I could be wrong about this but I don't ever remember these tubes mentioned as being useable in the LD.


----------



## TrollDragon (Sep 22, 2018)

jimtaylor said:


> Hi, another question. I got a pair of 1960's made Sylvania 6ah6wa's for a good price and was curious about how to be able to plug them into the little dot? Can anyone point me to where in the thread there is a guide to be able to convert it the Little Dot sockets to be able to use them?


You have to strap pins 2 and 7 together to use those tubes.

You can do it with a jumper in the socket or solder directly to the pins.  Soldering has a chance to crack the glass when heating the pin. Make sure the pin is well cleaned with sandpaper or a file before tinning, put the wire on the pins, apply solder flux and use only as much heat to get the wire to stick.

_**Do this at your own risk**_



 

Table from this post and strapping info at the end of it.
https://www.head-fi.org/threads/lit...ube-rolling-guide.563884/page-77#post-9392055


----------



## jimtaylor

TrollDragon said:


> You have to strap pins 2 and 7 together to use those tubes.
> 
> You can do it with a jumper in the socket or solder directly to the pins.  Soldering has a chance to crack the glass when heating the pin. Make sure the pin is well cleaned with sandpaper or a file before tinning, put the wire on the pins, apply solder flux and use only as much heat to get the wire to stick.
> 
> ...



What gauge of wire did you use? That's some small wire.


----------



## TrollDragon

jimtaylor said:


> What gauge of wire did you use? That's some small wire.


That is 30AWG wrap wire. 
https://www.adafruit.com/product/1446


----------



## jimtaylor

Thanks for answering all my questions, this is an addicting hobby. It's fun trying to figure it all out. I was thinking about getting the wire and doing the bridge inside a socket saver. I am still waiting for my first set of 7 pin socket savers to come in the mail. Do you think any of these would also work:

http://www.radiodaze.com/7-pin-minature-printed-circuit-socket-brown-item-nos-skt-23/


----------



## gibosi

That link looks to be a socket, not a socket saver. And unfortunately, it seems that 7-pin socket savers are not all that easy to find....  

But yes, back in the day, I took apart 7-pin socket savers and used 30 gauge connecting wire to strap pins 2 (cathode) and 7 (grid 3) internally. The same strapping will allow you to run 6AU6.


----------



## gibosi

gibosi said:


> That link looks to be a socket, not a socket saver. And unfortunately, it seems that 7-pin socket savers are not all that easy to find....
> 
> But yes, back in the day, I took apart 7-pin socket savers and used 30 gauge connecting wire to strap pins 2 (cathode) and 7 (grid 3) internally. The same strapping will allow you to run 6AU6.



It looks like Leeds Radio still has 7-pin socket savers

Test socket 7 pin miniature                           $8.00

http://leedsradio.com/parts-sockets.html#savers


----------



## Whelkie D

gibosi said:


> It looks like Leeds Radio still has 7-pin socket savers
> 
> Test socket 7 pin miniature                           $8.00
> 
> http://leedsradio.com/parts-sockets.html#savers


Or here................https://www.ebay.co.uk/itm/1-7Pin-G...m=173505021099&_trksid=p2045573.c100033.m2042


----------



## gibosi (Sep 23, 2018)

Whelkie D said:


> Or here................https://www.ebay.co.uk/itm/1-7Pin-Gold-plated-tube-socket-saver-for-6AU6-6AQ5-6X4-ECC91-and-so-on/173505021099?_trkparms=aid=111001&algo=REC.SEED&ao=1&asc=20131017132637&meid=271d50e53b6e40ed8ef616e7c1e4482a&pid=100033&rk=1&rkt=8&sd=173505021099&itm=173505021099&_trksid=p2045573.c100033.m2042



In the pictures provided in that eBay listing, I see a screw head on the bottom between the pins, but still, I am not sure you can actually disassemble this socket saver in order to solder wire connections.

I bought these from Leeds Radio several years ago. And as you can see, they are easy to disassemble. That said, I am not sure if the ones that Leeds now has are the same,


----------



## TrollDragon

Be aware that any socket saver/tester with exposed pins like the one above has *very dangerous voltages* on those pins when the amplifier is running.


----------



## jimtaylor

TrollDragon said:


> Be aware that any socket saver/tester with exposed pins like the one above has *very dangerous voltages* on those pins when the amplifier is running.



Which one, the leads radio one? Or these gold ones? 

https://www.ebay.com/itm/1-7Pin-Gol...m=173505021099&_trksid=p2045573.c100033.m2042


----------



## gibosi

Leeds Radio. Notice that on top of the test socket, next to the pin holes, there are exposed metal pins. Since these are test sockets, the exposed metal pins allow one to take electrical measurements while the tube is in operation. So per TrollDragon's warning, when the amp is powered on, *DO NOT TOUCH!*


----------



## jimtaylor

gibosi said:


> Leeds Radio. Notice that on top of the test socket, next to the pin holes, there are exposed metal pins. Since these are test sockets, the exposed metal pins allow one to take electrical measurements while the tube is in operation. So per TrollDragon's warning, when the amp is powered on, *DO NOT TOUCH!*



Would electrical tape around them help make them just a little safer?


----------



## gibosi

Sure. While I have never felt the urge to touch these pins while listening to music, if you think you might be tempted, then electrical tape would do the trick.


----------



## jimtaylor

gibosi said:


> Sure. While I have never felt the urge to touch these pins while listening to music, if you think you might be tempted, then electrical tape would do the trick.



The temptation is just too much... No honestly, I just have a touchy daughter. I could just imagine it happening now, I get up to go to the bathroom and she shocks herself. I rather not have the wife kill me.


----------



## gibosi

For sure, better safe than sorry.


----------



## mordy

Back in they days I got shocked twice - 155V. Not fun.


----------



## Theabs

Looking for some guidance here: I purchased some Voskhod 6J1P-EV tubes from The Tube Store online for my Little Dot II++. I swapped them in, no output. These are EF95-type tubes, I thought they'd be compatible. Is there an internal setting I need to change? Thanks for the help!


----------



## Theabs

Theabs said:


> Looking for some guidance here: I purchased some Voskhod 6J1P-EV tubes from The Tube Store online for my Little Dot II++. I swapped them in, no output. These are EF95-type tubes, I thought they'd be compatible. Is there an internal setting I need to change? Thanks for the help!


Anyone have thoughts on this? I was going by the tube guide on page one, assuming that EF95 tubes can be used with a LD II++. Thanks in advance for any assistance!


----------



## MIKELAP

Theabs said:


> Looking for some guidance here: I purchased some Voskhod 6J1P-EV tubes from The Tube Store online for my Little Dot II++. I swapped them in, no output. These are EF95-type tubes, I thought they'd be compatible. Is there an internal setting I need to change? Thanks for the help!


Hi i had the Tesla 6F32 with is similar ti the 6jip LDMK3 and they worked


Theabs said:


> Anyone have thoughts on this? I was going by the tube guide on page one, assuming that EF95 tubes can be used with a LD II++. Thanks in advance for any assistance!


Try search function ,also your 6j1p seems similar to the 6F32 tube that i use to run in LDMK3 here's link https://www.ebay.ca/itm/10-X-6J1P-E...003661?hash=item3b0458df4d:g:JC0AAOSwt2paoTme


----------



## Theabs

MIKELAP said:


> Hi i had the Tesla 6F32 with is similar ti the 6jip LDMK3 and they worked
> 
> Try search function ,also your 6j1p seems similar to the 6F32 tube that i use to run in LDMK3 here's link https://www.ebay.ca/itm/10-X-6J1P-E...003661?hash=item3b0458df4d:g:JC0AAOSwt2paoTme



I'm wondering if there's a compatibility issue with the EF95/6J1p-EV & the LD II++, which is an older model.


----------



## MIKELAP (Oct 3, 2018)

Theabs said:


> I'm wondering if there's a compatibility issue with the EF95/6J1p-EV & the LD II++, which is an older model.[/QUOTE





Theabs said:


> I'm wondering if there's a compatibility issue with the EF95/6J1p-EV & the LD II++, which is an older model.


You sure your on ef95 setting ? also from what i see 6j1 are stock driver tubes (front tubes)and on a side note  if you look at page 77 the littledot 2+ is listed there and able to use the tubes on that list some are plug n play .


----------



## Theabs

MIKELAP said:


> You sure your on ef95 setting ? also from what i see 6j1 are stock driver tubes (front tubes)and on a side note  if you look at page 77 the littledot 2+ is listed there and able to use the tubes on that list some are plug n play .



No I'm not sure: is this a setting change inside, accessed by removing the bottom screws? Thanks.


----------



## MIKELAP

Theabs said:


> No I'm not sure: is this a setting change inside, accessed by removing the bottom screws? Thanks.


First of all do you have an other pair of ef95 tubes you could try ,maybe its the tubes? if the other pair you try doesnt work your probably not on the right setting i had a little mk 3 to change from ef95 to ef 92 settings we had jumpers accessible thru peep holes under but yours i think you remove the cover yes .i would check on the thread for pictures of inside


----------



## gibosi

Theabs said:


> I'm wondering if there's a compatibility issue with the EF95/6J1p-EV & the LD II++, which is an older model.



I believe that the LD II++ shipped with EF92 as drivers. I don't know if it is possible to run EF95 tubes in this amp, but if so, it would be necessary to change some jumpers as the EF95 has a different pinout. Unfortunately, since the LD II++ was first introduced in 2006, it is difficult to find much info on this amp....


----------



## Theabs

MIKELAP said:


> First of all do you have an other pair of ef95 tubes you could try ,maybe its the tubes? if the other pair you try doesnt work your probably not on the right setting i had a little mk 3 to change from ef95 to ef 92 settings we had jumpers accessible thru peep holes under but yours i think you remove the cover yes .i would check on the thread for pictures of inside



I tried 2 sets of tubes, no output. I'll search for some internal pics of the II++, and I'll open it up tonight, to see what I can figure out. Thanks.


----------



## TrollDragon

Theabs said:


> I'm wondering if there's a compatibility issue with the EF95/6J1p-EV & the LD II++, which is an older model.


The old Little Dot II++ uses CV131 driver tubes and 6C19 output tubes. It does not have the option to use EF95 tubes so you're limited to EF92 compatible tubes only.


----------



## MIKELAP

gibosi said:


> I believe that the LD II++ shipped with EF92 as drivers. I don't know if it is possible to run EF95 tubes in this amp, but if so, it would be necessary to change some jumpers as the EF95 has a different pinout. Unfortunately, since the LD II++ was first introduced in 2006, it is difficult to find much info on this amp....


Ok its a ++ model didnt know that one was thinking typo .good to know.


----------



## Theabs

TrollDragon said:


> The old Little Dot II++ uses CV131 driver tubes and 6C19 output tubes. It does not have the option to use EF95 tubes so you're limited to EF92 compatible tubes only.



That's what I was afraid of. Guess I have 6 EF95 tubes available......


----------



## mordy

Theabs said:


> That's what I was afraid of. Guess I have 6 EF95 tubes available......


Hi T,
Don't feel bad; I have maybe 200 different EF95, 6AK5, 5654, 6J1P, M8100, CV 4010, CV850 etc from my Little Dot MKIII days.
Don't use them any more.
Many of them were bought as used. If anybody is interested in something, please PM me.


----------



## Theabs

mordy said:


> Hi T,
> Don't feel bad; I have maybe 200 different EF95, 6AK5, 5654, 6J1P, M8100, CV 4010, CV850 etc from my Little Dot MKIII days.
> Don't use them any more.
> Many of them were bought as used. If anybody is interested in something, please PM me.


PM sent.


----------



## gibosi

Theabs said:


> PM sent.



And if you need more, I have a bunch too.


----------



## Theabs

gibosi said:


> And if you need more, I have a bunch too.



I only need EF92 type, all of mordy's are EF95.


----------



## mordy

gibosi said:


> And if you need more, I have a bunch too.


Hi gibosi,
I was thinking of you when I wrote it lol.......
Do you a remember a British chap that posted on the LD thread way back that had over 7000 tubes?


----------



## shepperd

I'm still interested in some Tesla's... the one's with the white hat I believe! Mine died suddenly before I could get a sense for them. (EF95 of course) I stopped tube rolling a while back, finding the Voshkod and the yugo the best for my ears but the itch still remains.


----------



## Johnybuchar

I own them all . Now i am listening via SYLVANIA JAN 5654W/6AK5W Black Plate and I am riveting by airy trebles and space. I like my collection of tubes.


----------



## Tony51

Johnybuchar said:


> I own them all . Now i am listening via SYLVANIA JAN 5654W/6AK5W Black Plate and I am riveting by airy trebles and space. I like my collection of tubes.


When I took a first listen to my Sylvania jhs 5670 from 1962 I had the same reaction but further listening against the Western Electric 396a(5670) truly outperformed the Sylvania in refinement, vocals, bass and treble. But you are right about the airy treble on the Sylvania and that was what had me at hello. Bass lacks. Add  Western Electric to your collection.....expensive though.


----------



## gibosi

Tony51 said:


> When I took a first listen to my Sylvania jhs 5670 from 1962 I had the same reaction but further listening against the Western Electric 396a(5670) truly outperformed the Sylvania in refinement, vocals, bass and treble. But you are right about the airy treble on the Sylvania and that was what had me at hello. Bass lacks. Add  Western Electric to your collection.....expensive though.



What amp are you running these in? The 5670/2C51 is a double triode and won't work natively in the LD....


----------



## Tony51

gibosi said:


> What amp are you running these in? The 5670/2C51 is a double triode and won't work natively in the LD....


I am running the WE 396a(5670) on my Audioromy 6v6 amplifier. But I know that WE 5654 makes them because I just bought a set for the Little Dot mk2 which I am burning them in as we speak. Not listened to sound yet on my LD but my W.E 5670 are sounding pretty great on my Audioromy amp.


----------



## shepperd

I have a question; on several occasions I have had tubes light up normally but no sound. They have low hours and came in their original boxes with the codes corresponding. One set were teslas, another Voshkod  which are supposedly indestructable. I cannot for the life of me understand this. I know they are compatable because they worked for a long time with no problem. Any thoughts?


----------



## Johnybuchar

Oogh nice tubeamp. Do you use it as standard amplifier too? I have headamp LittleDot3 and integrated tubeamp Yaqin MC100B + AurumCantus V3M and I am still surprised their listening, great products from China! 

BTW my tube collection will be appended by Siemens or Telefunken .


----------



## gibosi

shepperd said:


> I have a question; on several occasions I have had tubes light up normally but no sound. They have low hours and came in their original boxes with the codes corresponding. One set were teslas, another Voshkod  which are supposedly indestructable. I cannot for the life of me understand this. I know they are compatable because they worked for a long time with no problem. Any thoughts?



Just guessing, perhaps it is a pin/socket problem. While the heater connection is good, evidenced by the fact that they light up, if the cathode or grid or plate pins are not making a good connection in the socket, there would be no sound.

I suggest you aggressively clean the pins. Many here scrape the pins with the dull edge of an x-acto blade.


----------



## Tony51 (Oct 6, 2018)

Johnybuchar said:


> Oogh nice tubeamp. Do you use it as standard amplifier too? I have headamp LittleDot3 and integrated tubeamp Yaqin MC100B + AurumCantus V3M and I am still surprised their listening, great products from China!
> 
> BTW my tube collection will be appended by Siemens or Telefunken .


I only use it as a headphone amp but I did connected to my SVS Ultra Towers and at 12watts per channel into 8 Ohms and it pushed them well. Not better then a solid state but very good considering my towers have 88 db and the Audioromy asks for 90db if my memory serves me well.
Telefunken is in my bucket list I hear nothing but praise.
Which Siemens are you using? The blue glass?


----------



## Johnybuchar

I am generally looking for products of Siemens/Telefunken, i am reading and collecting information because I do not have opportunity to listen them. About listening via speakers, Yaqin is beast , no problem with Quadral Amun mk4 - 3way, sensitivity 84dB!


----------



## Tony51

What's the model of your yaqin?


----------



## Johnybuchar

Yaqin MC100B, I know low-cost but superb sound. Great to switch triode vs pentode according to mood and taste . Outcome depends on tube rolling, do not hesitate to spend sum approaching value of the amplifier bacause of fully tube amplifier is "live instrument". I cannot imagine a listening without tubes!


----------



## Tony51

What is the difference between pentiode and tridiode?
I'm running Tung-Sol 6v6GT Russian made
2 Gold Lion gold pin 6n1(6922)russ Rus made
1 6n3(5670/396a) Western Electric


----------



## TrollDragon

Tony51 said:


> I am running the WE 396a(5670) on my Audioromy 6v6 amplifier. But I know that WE 5654 makes them because I just bought a set for the Little Dot mk2 which I am burning them in as we speak. Not listened to sound yet on my LD but my W.E 5670 are sounding pretty great on my Audioromy amp.


Nice, I have a pair of JAN GE 5670s in my Quinpu A3, good tube.


----------



## Tony51

TrollDragon said:


> Nice, I have a pair of JAN GE 5670s in my Quinpu A3, good tube.


The Jan GE 5670 is darn good too. Mine has triple mica, I also have the jan5670w.


----------



## shepperd

gibosi said:


> Just guessing, perhaps it is a pin/socket problem. While the heater connection is good, evidenced by the fact that they light up, if the cathode or grid or plate pins are not making a good connection in the socket, there would be no sound.
> 
> I suggest you aggressively clean the pins. Many here scrape the pins with the dull edge of an x-acto blade.


----------



## shepperd

The pins looked squeeky clean but I used some Craig's conditioner and cleaner on them anyway and the tubes work again. Pretty strange behavior but tubes are strange little beasts.


----------



## Anomalia

What tubes would be best option when using hifiman 400i (35 ohms) with LD 3? Now using standard power tubes with mullard cv4010 and sounding great.
6N6P-IR + 6HM5?
6SN7 not compatible with low impedance? Or should I try, 400i are quite easy to drive.


----------



## Ad720

Hi all, I just received a second hand Little Dot MKii and the previous owner included a few different tubes. I had already ordered a set of Voshod 6ZH1P-EV preamp tubes.

 In the meantime time, I spent some time listening with the tubes furnished by the seller which include GE Jan 5654w preamp tubes and 6h6n power amp tubes of unknown manufacturer. 

My impression was very good but I felt that the bass was a little boomy and uncontrolled. 

Should I expect my incoming preamp tubes upgrade to help with that or should I be looking to upgrade these power tubes as well?


----------



## TrollDragon

Anomalia said:


> What tubes would be best option when using hifiman 400i (35 ohms) with LD 3? Now using standard power tubes with mullard cv4010 and sounding great.
> 6N6P-IR + 6HM5?
> 6SN7 not compatible with low impedance? Or should I try, 400i are quite easy to drive.


OTL amps like the LDMK2/3/4 are not really designed to work well with low Z headphones, there is a bass roll off because of the low resistance.

Hybrid amps like the LD I+ are better suited for low Z.


----------



## TrollDragon

Ad720 said:


> Hi all, I just received a second hand Little Dot MKii and the previous owner included a few different tubes. I had already ordered a set of Voshod 6ZH1P-EV preamp tubes.
> 
> In the meantime time, I spent some time listening with the tubes furnished by the seller which include GE Jan 5654w preamp tubes and 6h6n power amp tubes of unknown manufacturer.
> 
> ...


Which headphones are you using with the MK2?


----------



## Ad720

TrollDragon said:


> Which headphones are you using with the MK2?



HD6xx and DT880 (250 ohm) mostly. The rest of my collection are all lower impedence.


----------



## Anomalia

TrollDragon said:


> OTL amps like the LDMK2/3/4 are not really designed to work well with low Z headphones, there is a bass roll off because of the low resistance.
> 
> Hybrid amps like the LD I+ are better suited for low Z.



Hifiman + LD is great sounding combination. There is no bass roll off and there is power more than enought. OTL is not designed for these, but in this case perfect match!

If I remember right only he400 series sounds great using LD.


----------



## Ad720

Can anything help identify these power tubes?


----------



## gibosi

Not sure exactly what information you are asking for... They appear to be 6N6P, a fairly common Soviet tube. However, I am inclined to think that these might actually be Chinese-made

http://www.sovtube.com/tubes/282-6n6p.html

https://frank.pocnet.net/sheets/113/6/6N6P.pdf


----------



## mordy

gibosi said:


> Not sure exactly what information you are asking for... They appear to be 6N6P, a fairly common Soviet tube. However, I am inclined to think that these might actually be Chinese-made
> 
> http://www.sovtube.com/tubes/282-6n6p.html
> 
> https://frank.pocnet.net/sheets/113/6/6N6P.pdf


Here are pictures of the logos of Russian vacuum tube manufacturers - none of them look like the logo with the star on the tubes of AD720.
http://www.ominous-valve.com/russtube.html


----------



## Ad720

Thanks..mostly I am trying to determine which of these sets are the stock tubes for the LDMkii. I'm clear that the first picture is the Soviet standard 6n6p but I'm not sure if those were the stock tubes. My guess for the second pic was something of Chinese manufacture.


----------



## Oskari

Ad720 said:


> Can anything help identify these power tubes?


1987 NEVZ-Soyuz, Novosibirsk 6N6P


Ad720 said:


>


1980 Beijing 6N6-T (I think, the one in front)


----------



## Ad720

Oskari said:


> 1987 NEVZ-Soyuz, Novosibirsk 6N6P
> 
> 1980 Beijing 6N6-T (I think, the one in front)



Thank you! 

In the second picture the markings on the tubes are identical, however the markings are printed in opposite directions of each other. 

So, in your opinion, would it be safe to say that neither of these sets are original to the MKii? I'm using the NEVZ-Soyuz now and I'm pretty happy with them but I have been researching power amp tube upgrades.


----------



## Oskari

Ad720 said:


> So, in your opinion, would it be safe to say that neither of these sets are original to the MKii? I'm using the NEVZ-Soyuz now and I'm pretty happy with them but I have been researching power amp tube upgrades.


I see Beijing tubes in the photos.

https://www.littledot.net/forum/viewtopic.php?f=9&t=816


----------



## Ad720

Oskari said:


> I see Beijing tubes in the photos.
> 
> https://www.littledot.net/forum/viewtopic.php?f=9&t=816



Thank you!


----------



## mordy

Ad720 said:


> Thank you!


Hi Ad7,
I do want to point out that the manufacturer of the amp and the user of the amp have different goals when it comes to choosing tubes.
The manufacturer has to make sure that he has a good supply of tubes on hand and that of course it sounds good. Most tube manufacturers are long gone, and the only tubes available in quantity are from Russia and China.
An individual user only need a couple of tubes, and can therefore pick from many choices of old discontinued tubes which oftentimes sound better than the OEM tubes supplied.
Based on the above I would not be concerned about getting the same tubes that the manufacturer supplied, especially since many times the manufacturer switches between different tubes, depending on what is available and price etc. .


----------



## Ad720

mordy said:


> Hi Ad7,
> I do want to point out that the manufacturer of the amp and the user of the amp have different goals when it comes to choosing tubes.
> The manufacturer has to make sure that he has a good supply of tubes on hand and that of course it sounds good. Most tube manufacturers are long gone, and the only tubes available in quantity are from Russia and China.
> An individual user only need a couple of tubes, and can therefore pick from many choices of old discontinued tubes which oftentimes sound better than the OEM tubes supplied.
> Based on the above I would not be concerned about getting the same tubes that the manufacturer supplied, especially since many times the manufacturer switches between different tubes, depending on what is available and price etc. .



Totally. I just wanted to figure out what I had to here in my hands before I jump into the upgrades.


----------



## Johnybuchar (Oct 29, 2018)

Can you recommend some interesting tubes 5654/6AK5 which shouldn't missed in my collection (excluding senseless expensive), please? I have the collection: Mullard 8100, Tesla 6F32,  Voshgod 6zh1p-ev, JAN 5654W, Sylvania 5654W blackplate(Green print),RAYTHEON JAN 5654 Black Plate, 5Star, RCA 5654, Yugoslavia EI 6hm5 EH900 small. My favorite are Sylvania, Voshgod, Tesla 6F32.. I am looking for Siemens . I like tube collection as well bottles of wine .


----------



## mordy

Johnybuchar said:


> Can you recommend some interesting tubes 5654/6AK5 which shouldn't missed in my collection (excluding senseless expensive), please? I have the collection: Mullard 8100, Tesla 6F32,  Voshgod 6zh1p-ev, JAN 5654W, Sylvania 5654W blackplate(Green print),RAYTHEON JAN 5654 Black Plate, 5Star, RCA 5654, Yugoslavia EI 6hm5 EH900 small. My favorite are Sylvania, Voshgod, Tesla 6F32.. I am looking for Siemens . I like tube collection as well bottles of wine .


Try some Tung Sol tubes


----------



## Tony51

Johnybuchar said:


> Can you recommend some interesting tubes 5654/6AK5 which shouldn't missed in my collection (excluding senseless expensive), please? I have the collection: Mullard 8100, Tesla 6F32,  Voshgod 6zh1p-ev, JAN 5654W, Sylvania 5654W blackplate(Green print),RAYTHEON JAN 5654 Black Plate, 5Star, RCA 5654, Yugoslavia EI 6hm5 EH900 small. My favorite are Sylvania, Voshgod, Tesla 6F32.. I am looking for Siemens . I like tube collection as well bottles of wine .



Dont forget the Western Electric 5654 ...very good tube


----------



## gibosi

Johnybuchar said:


> Can you recommend some interesting tubes 5654/6AK5 which shouldn't missed in my collection (excluding senseless expensive), please? I have the collection: Mullard 8100, Tesla 6F32,  Voshgod 6zh1p-ev, JAN 5654W, Sylvania 5654W blackplate(Green print),RAYTHEON JAN 5654 Black Plate, 5Star, RCA 5654, Yugoslavia EI 6hm5 EH900 small. My favorite are Sylvania, Voshgod, Tesla 6F32.. I am looking for Siemens . I like tube collection as well bottles of wine .



And very generally speaking, most people prefer the sound of the tall 6HM5 over the short one.


----------



## Johnybuchar

Thanks for tips . I'm going to get some Siemens or Tungsol tubes.


----------



## KukoCL

I just ordered the MK2 with the Mullard CV4010 from Massdrop before reading this thread.
I will use it with my Senns HD6XX. ¿Is it too warm or dark for these cans?. Actually i want a warm, soft sound with relaxed treble and maybe deep bass (if posible), but not boomy and excesive.

I'm asking because i think i still can change the selected tubes for the Jan5654W which is the second selectable option in massdrop.


----------



## Tony51

KukoCL said:


> I just ordered the MK2 with the Mullard CV4010 from Massdrop before reading this thread.
> I will use it with my Senns HD6XX. ¿Is it too warm or dark for these cans?. Actually i want a warm, soft sound with relaxed treble and maybe deep bass (if posible), but not boomy and excesive.
> 
> I'm asking because i think i still can change the selected tubes for the Jan5654W which is the second selectable option in massdrop.


What power tubes are you running?
As to the driver tubes, 
You want warm and precision...look into the Western Electric 5654, expensive but smooth sailing.
Tony


----------



## KukoCL

Tony51 said:


> What power tubes are you running?
> As to the driver tubes,
> You want warm and precision...look into the Western Electric 5654, expensive but smooth sailing.
> Tony



It comes with the stock power tubes.
When ordering it I can only choose between the stock driver tubes, Jan5654w and CV4010, so I was wondering which one of those has a better approach to the sound I described.


----------



## Tony51 (Nov 6, 2018)

KukoCL said:


> It comes with the stock power tubes.
> When ordering it I can only choose between the stock driver tubes, Jan5654w and CV4010, so I was wondering which one of those has a better approach to the sound I described.



I have both, I'd go for the jan5654w, they are all around wonderful. Now if you could find the cv4015, these Mullard are even better sound than both. Right now I am using the Siemens with the blue glass which are sounding even better than all of the above. But it's not by far so believe me you will love the jan5654w.

What about the power tubes? Stock Chinese? If so, you might get away for a while but you really need to swap those also for better pure power.
I have the voshkod 6h30p-i these are top notch that will yield you a tad of more power and clarity.


----------



## Whelkie D

KukoCL said:


> I just ordered the MK2 with the Mullard CV4010 from Massdrop before reading this thread.
> I will use it with my Senns HD6XX. ¿Is it too warm or dark for these cans?. Actually i want a warm, soft sound with relaxed treble and maybe deep bass (if posible), but not boomy and excesive.
> 
> I'm asking because i think i still can change the selected tubes for the Jan5654W which is the second selectable option in massdrop.


If you are wanting a warm sound definitely go for the Mullards. I have a MK2 and am using some old Osram Z77 tubes with it. These give a very warm sound so I'd recommend these if you can get hold of some. You would have to change the internal jumper pins setting to accept EF91/EF92 though, but this is easy to do.


----------



## Tony51

KukoCL said:


> I just ordered the MK2 with the Mullard CV4010 from Massdrop before reading this thread.
> I will use it with my Senns HD6XX. ¿Is it too warm or dark for these cans?. Actually i want a warm, soft sound with relaxed treble and maybe deep bass (if posible), but not boomy and excesive.
> 
> I'm asking because i think i still can change the selected tubes for the Jan5654W which is the second selectable option in massdrop.



In that case, I think you'll like the Mullard, they are warmer than the jan5654w.


----------



## Onik

which tubes are compatible with LD MK II??


----------



## HungryPanda

EF95 is the one it is set for as standard


----------



## TrollDragon

Onik said:


> which tubes are compatible with LD MK II??


All the ones from the table in this post is a good start.
https://www.head-fi.org/threads/lit...ube-rolling-guide.563884/page-77#post_9392055


----------



## WilliamLeonhart

Actually it depends on the default tubes that your amp is shipped with


HungryPanda said:


> EF95 is the one it is set for as standard


----------



## Onik (Nov 13, 2018)

If I wanna swap my front tubes with Mullard CV4010 do I also need to swap the big/power tubes 6N6?


----------



## Tony51

Onik said:


> If I wanna swap my front tubes with Mullard CV4010 do I also need to swap the big/power tubes 6N6?


 You can swap the driver tubes independent of the rear power tubes.


----------



## KukoCL

Onik said:


> If I wanna swap my front tubes with Mullard CV4010 do I also need to swap the big/power tubes 6N6?


It's not needed. In fact, the MKII I bought from Massdrop comes with the cv4010 and the stock power tubes.


----------



## Onik

*is there any sound difference between LD I+ v2 or V4(2015) board?*


----------



## ChrisGoatpher

just bought a used LD1+ that comes with a pair of mullard cv401 and burr brown opamps. just got a ge jan 5654w and voshkod 6zh1p-eb thanks to this thread!


----------



## gulakpii

ChrisGoatpher said:


> just bought a used LD1+ that comes with a pair of mullard cv401 and burr brown opamps. just got a ge jan 5654w and voshkod 6zh1p-eb thanks to this thread!



Enjoy!    How do you like it?


----------



## KukoCL (Dec 7, 2018)

I noticed with my LD MKII, when i set the volume knob over 40% it starts to distort badly and the bass sounds unpowered. Anyways, at 40% the volume is very high and uncomfortable, but I would want to fix this for music or movies with higher dynamic range where I need to put the volume higher.

I guess the problem is I'm using the stock chinese power tubes.

What power tubes can I pair with the cv4010 I'm using right now?
I can't expend more than $50 right now.

Thanks.


----------



## TrollDragon

KukoCL said:


> I noticed with my LD MKII, when i set the volume knob over 40% it starts to distort badly and the bass sounds unpowered. Anyways, at 40% the volume is very high and uncomfortable, but I would want to fix this for music or movies with higher dynamic range where I need to put the volume higher.
> 
> I guess the problem is I'm using the stock chinese power tubes.
> 
> ...


What headphones are you using and have you tried changing the gain switches?


----------



## Tony51

KukoCL said:


> I noticed with my LD MKII, when i set the volume knob over 40% it starts to distort badly and the bass sounds unpowered. Anyways, at 40% the volume is very high and uncomfortable, but I would want to fix this for music or movies with higher dynamic range where I need to put the volume higher.
> 
> I guess the problem is I'm using the stock chinese power tubes.
> 
> ...



I had the same issues with distortion at high volume. I replaced the power tubes also for the russian sovtek 6h30pi and it works fantastic, these have more power than the cheaper 6n6 russian tubes. No need to replace the mullard but you can try the jan5654w which are cheap and sound very freaking good. As for the switches i have them on high gain because i used it with my beyerdynamic dt1990 pro which have 250 ohm impedance, so high gain should be used.


----------



## Acapella11

As Trolldragon asked, it would be relevant to know your headphones. Distortions can more likely happen with lower impedance headphones. The 6H30-PI are somewhat more powerful, but the former conclusion in the forum, and IMHO, the 6N6P-IR sound better. Maybe it is helpful if you take a look at the tube table in the sig below


----------



## Whelkie D

I'm considering trying some 6DJ8 tubes instead of the 6N6p as power tubes in my LD mk2. Can I just replace them or do I have to make any adaptations etc? Thanks


----------



## Acapella11

Don’t think you need to adapt anything. This was the note we had in the tube table below.


----------



## KukoCL (Dec 9, 2018)

TrollDragon said:


> What headphones are you using and have you tried changing the gain switches?


I'm using HD6XX with the higher gain setting. I didn't try the other gain configurations.

Thanks for the tubes table. I'll check some prices from the recommended power tubes in the table.

Edit: this one looks good. https://www.ebay.com/itm/6N6P-IR-EC...m=171310973012&_trksid=p2056116.c100935.m2460


----------



## gibosi

Whelkie D said:


> I'm considering trying some 6DJ8 tubes instead of the 6N6p as power tubes in my LD mk2. Can I just replace them or do I have to make any adaptations etc? Thanks



They are plug and play in the LD. However, the 6DJ8 is not nearly as powerful as the 6N6p and therefore, when used as output tubes, they may not be able to drive inefficient and/or low Z cans well.


----------



## Whelkie D

gibosi said:


> They are plug and play in the LD. However, the 6DJ8 is not nearly as powerful as the 6N6p and therefore, when used as output tubes, they may not be able to drive inefficient and/or low Z cans well.


Thanks for the heads-up on that. I'll probably try a pair just to satisfy my obsessive curiosity. Is there a big difference in sound quality (good or bad) with the 6DJ8? I guess it depends on the make. Any recomendations for a (cheapish) decent make?


----------



## gibosi

The 6DJ8 was made by many manufacturers. And given that we all have different ears and different gear, determining what is "good" and "bad" is very subjective. That said, many believe that the early Holland-made white-label Bugle Boys are very good for the money. The legendary Joe's Tube Lore is a good place to start:

https://www.audioasylum.com/audio/faq/joes-tubes.html#6DJ8

However, unlike Joe, I really like the mid-1970's 6N23P (6H23N) manufactured by Reflector and Voskhod.

Have fun!


----------



## KukoCL

Sorry for the noob question, but does changing the power tubes produce a sound improvement? or just more power for higher volumes?.
Not being skeptical, just never had the chance to try different power tubes, only driver tubes.


----------



## Whelkie D

KukoCL said:


> Sorry for the noob question, but does changing the power tubes produce a sound improvement? or just more power for higher volumes?.
> Not being skeptical, just never had the chance to try different power tubes, only driver tubes.


I upgraded the power tubes from the stock chinese ones on my LDmk2 to Russian 6n6p. The improvement in sound was very noticeable. Affected about 20% of the overall sound quality.


----------



## KukoCL

I bought a matched pair of 6N1P russian power tubes by mistake.. 
Can i put these in my Little dot Mkii?


----------



## Tony51

KukoCL said:


> I bought a matched pair of 6N1P russian power tubes by mistake..
> Can i put these in my Little dot Mkii?



No sir.


----------



## nofacemonster

I just ordered my first fully tube headphone amplifier little dot MKII for my HD-6XX. That's the best of money that i have could buy. It is a big relief to know that these doesn't require matched tubes. In a time that everything keep getting expensive it sure is a relief to know.


----------



## Tony51

It's a pretty darn good tube amp but you do need some tube rolling.


----------



## Onik

whats the best sounding tubes for LD I+ and MKII?


----------



## nofacemonster

I bought a little dot MKII for my HD6XX and it sounds wonderful. I just want to buy few extra power tubes just keep as spares. Does it require matched pairs? Because matched pairs are expensive. I have seen some headfiers saying MKII doesn't need matched pairs because the channels are running separately and independently. I don't understand all the technical stuff behind this so please enlighten me with your wisdom.



TrollDragon said:


> Matched pairs are absolutely pointless on the Little Dot MK II, III & IV since the tubes are not run in parallel.
> 
> If you think that the tubes are suspect and possibly shorted then by all means get them tested. Paying someone to match them for you will not give you any benefit in the sound and will just make the guy who tests them an easy $20 or more...


----------



## TrollDragon

nofacemonster said:


> I bought a little dot MKII for my HD6XX and it sounds wonderful. I just want to buy few extra power tubes just keep as spares. Does it require matched pairs? Because matched pairs are expensive. I have seen some headfiers saying MKII doesn't need matched pairs because the channels are running separately and independently. I don't understand all the technical stuff behind this so please enlighten me with your wisdom.


Little dot amps (MK2/3/4) do not use "power tubes", calling the output tubes that is a bit of a misnomer as the amplifier is just a preamp. Matched tubes are required for push pull amplifiers that output to speakers. You need to match the tubes so they have the same plate current, unmatched tubes with one tube drawing more current will wear that tube out earlier than the other.

Matching of preamp tubes is a way for sellers to squeeze more money out of you.


----------



## nofacemonster

TrollDragon said:


> Little dot amps (MK2/3/4) do not use "power tubes", calling the output tubes that is a bit of a misnomer as the amplifier is just a preamp. Matched tubes are required for push pull amplifiers that output to speakers. You need to match the tubes so they have the same plate current, unmatched tubes with one tube drawing more current will wear that tube out earlier than the other.
> 
> Matching of preamp tubes is a way for sellers to squeeze more money out of you.



I may not be a pro but mk2 has power tubes. They call those two big tubes power tubes.


----------



## nofacemonster

TrollDragon said:


> Little dot amps (MK2/3/4) do not use "power tubes", calling the output tubes that is a bit of a misnomer as the amplifier is just a preamp. Matched tubes are required for push pull amplifiers that output to speakers. You need to match the tubes so they have the same plate current, unmatched tubes with one tube drawing more current will wear that tube out earlier than the other.
> 
> Matching of preamp tubes is a way for sellers to squeeze more money out of you.



Doesn't SEPP means single ended push pull


----------



## Tony51

TrollDragon said:


> Little dot amps (MK2/3/4) do not use "power tubes", calling the output tubes that is a bit of a misnomer as the amplifier is just a preamp. Matched tubes are required for push pull amplifiers that output to speakers. You need to match the tubes so they have the same plate current, unmatched tubes with one tube drawing more current will wear that tube out earlier than the other.
> 
> Matching of preamp tubes is a way for sellers to squeeze more money out of you.


Little Dot Mk2 has power tubes, the two tallest ones out of the 4 tubes. Or am I missing something?


----------



## KukoCL

Tony51 said:


> Little Dot Mk2 has power tubes, the two tallest ones out of the 4 tubes. Or am I missing something?


Yeah, I thought the same. I know the tallest tubes are the power tubes and the small the driver tubes. I have the MKII too and now I'm confused lol.

So, unmatched pairs only gives you less lifetime? I thought I was going to get more volume in one channel.


----------



## gibosi

Over the years, this topic has been discussed in this forum many times. And if you read through the postings, you will discover that TrollDragon knows what he is talking about. The "tallest tubes" are not power tubes. All they do is provide a bit more gain.

Yes, you will get the best sound if you choose two output tubes manufactured by the same manufacturer at about the same time with similar measurements. But if you ignore this advice, it won't matter. It won't hurt a thing. So again, purchasing so-called "matching" tubes at premium prices is a waste of money. But of course, in the end, it is your money. So if it makes you feel good, go for it.

Cheers


----------



## Tony51

gibosi said:


> Over the years, this topic has been discussed in this forum many times. And if you read through the postings, you will discover that TrollDragon knows what he is talking about. The "tallest tubes" are not power tubes. All they do is provide a bit more gain.
> 
> Yes, you will get the best sound if you choose two output tubes manufactured by the same manufacturer at about the same time with similar measurements. But if you ignore this advice, it won't matter. It won't hurt a thing. So again, purchasing so-called "matching" tubes at premium prices is a waste of money. But of course, in the end, it is your money. So if it makes you feel good, go for it.
> 
> Cheers




interesting indeed.


----------



## mordy

Tony51 said:


> interesting indeed.


I also want to add that in the tube era a pair of tubes that measured within 10% of each other was considered perfectly acceptable.
This was told to me by an old friend who is an A/V engineer.


----------



## Tony51

mordy said:


> I also want to add that in the tube era a pair of tubes that measured within 10% of each other was considered perfectly acceptable.
> This was told to me by an old friend who is an A/V engineer.



We learn something new every day. Thanks for the info.


----------



## nofacemonster

TrollDragon said:


> Little dot amps (MK2/3/4) do not use "power tubes", calling the output tubes that is a bit of a misnomer as the amplifier is just a preamp. Matched tubes are required for push pull amplifiers that output to speakers. You need to match the tubes so they have the same plate current, unmatched tubes with one tube drawing more current will wear that tube out earlier than the other.
> 
> Matching of preamp tubes is a way for sellers to squeeze more money out of you.



Sir...! if this is really true, those two big tubes it has doesn't work like in one of those big tube amplifiers with multiple output tubes for each channel (Specially speaker amps). Alright according to you they are output tubes and not power tubes, so we need no worrying about matching. It's a relief to know it because i am about to order some russian 6N6 power tubes for my amp.


----------



## TrollDragon

Tony51 said:


> Little Dot Mk2 has power tubes, the two tallest ones out of the 4 tubes. Or am I missing something?



https://carvinaudio.com/blogs/guita...ower-amp-tubes-what-they-are-and-what-they-do


----------



## TrollDragon

Voshkod, Phillips or Power tubes... 

At the end of the day it really doesn't matter as long as you enjoy the music.


----------



## KukoCL

TrollDragon said:


> Voshkod, Phillips or Power tubes...
> 
> At the end of the day it really doesn't matter as long as you enjoy the music.


I was asking just because I don't want to expend unnecessary money on matched power tubes if I can buy unmatched.


----------



## TrollDragon

KukoCL said:


> I was asking just because I don't want to expend unnecessary money on matched power tubes if I can buy unmatched.


Not a problem, you do not need to purchase matched pairs.


----------



## Tony51

TrollDragon said:


> https://carvinaudio.com/blogs/guita...ower-amp-tubes-what-they-are-and-what-they-do



Interesting read...thanks for the link.


----------



## BattousaiX26

Hi guys, I just wanna ask if there is any difference between an AEG 6ak5 tube with diamond on bottom and one that has not?


----------



## DaaDaa

is the 6HM5 equivalent to 6J1?


----------



## Whelkie D

Dadbeh said:


> is the 6HM5 equivalent to 6J1?


Yes. I use the (former) Yugoslavian EI 6hm5 tall tubes in the EF95 position. They are some of my favourites. I recommend them.


----------



## mat.1 (Jan 29, 2019)

what year is this tube and is it original 6h30 DR ?
can i use in rolling with 6922 amp ?
Thanks.
​


----------



## mordy

mat.1 said:


> what year is this tube and is it original 6h30 DR ?
> can i use in rolling with 6922 amp ?
> Thanks.
> ​


1086 means October 1986


----------



## mat.1

mordy said:


> 1086 means October 1986


Thanks.


----------



## gibosi

mat.1 said:


> what year is this tube and is it original 6h30 DR ?
> can i use in rolling with 6922 amp ?
> Thanks.
> ​



Maybe you can roll this in your 6922 amp...  The pinout is the same, but the heater current is different. The 6922 draws 0.3 amps while the 6H30 draws 0.9 amps. This is significant. It is very possible that your amp was not designed to provide this much current, and the amp could over-heat and fail. Further, the 6922 has an amplification factor of 33 while the AF for the 6H30 is half of that, 15. So it is not a direct replacement, but it will work in some amps. Be careful...


----------



## perfect-pitch

Hello guys. I am selling my Mullard Master Series EF95 6AK5 tubes which i've bought some years ago as backup for my Little Dot. PM if interested


----------



## nofacemonster

I just received these. Tested and labelled but i don't know how to choose the closest matching pair. Which numbers should i match.


----------



## mordy

I assume that you need one pair. Just pick two that the four numbers are close.
Even if you picked numbers that are very different, I doubt that you will be able to hear a difference since they are all close.


----------



## Onik

EF 91 VS EF 95 which one sounds the best ?


----------



## gibosi

Not all EF 91 sound the same. And not all EF 95 sound the same. Further, everyone has different ears and different gear. So what one person considers the "best" is just OK for another. The only way to know what is "best" for you is to read as much as you can about these tubes, select one or two, and start rolling....


----------



## Whelkie D

Onik said:


> EF 91 VS EF 95 which one sounds the best ?


As gibosi said, they don't all sound the same. I have some EF95s that suit some moods/styles of music and others that suit different ones. Same goes for EF91s, although I must admit that I really like the warm sound of some old Osram z77 tubes that I got cheap on ebay.


----------



## Onik

Does the size makes any difference as the EF95 is smaller than EF91, I just thought bigger is better LOL


----------



## mordy

Onik said:


> Does the size makes any difference as the EF95 is smaller than EF91, I just thought bigger is better LOL


Within the same type of tube size does not matter. However, construction, materials  and age can make a difference, although there are no hard and fast rules.
You will find that tubes with more internal bracing such as triple mica discs and more support rods may sound better since these factors can effect the microphonics of the tube.
As a rule ( but always with exceptions) you may assume that older versions of tubes may sound better because of greater care in selecting materials and quality control.
About size, certain tube equivalents can be found in different incarnations over the years. My personal impression is that an older shoulder type (big glass bulb) tube many times sounds better than a similar, newer and smaller tube with straight glass. However, I don’t know if your amp can use these types of tubes.


----------



## nutsfortubes

Dumb question. Can 6N6 tube be replaced with 6N6P?


----------



## OctavianH (Feb 10, 2019)

Yes, I used 6N6P and 6N6P-IR on the Littledot MK2. You can see here (on the right) the 6N6P-IR:






On the left is my favorite driver, Voshkod 6ZH1P-EV. The difference between 6N6P and 6N6P-IR was that the last one was more neutral than the other. The same specs.


----------



## nutsfortubes

Thanks


----------



## Onik (Feb 11, 2019)

is rolling power tubes really necessary to improve sound quality for LD MK II? if yes which power tube can shine amp?


----------



## Tony51

You can get by using stock but if you roll it will sound a bit better. Power tubes affect the overall sound but not more than the driver tubes will.


----------



## nutsfortubes

Which driver tubes would that be?


----------



## Tony51

nutsfortubes said:


> Which driver tubes would that be?


There's a whole mess but I settled on the jan5654w, cheap and very good sounding.


----------



## Onik

Tony51 said:


> You can get by using stock but if you roll it will sound a bit better. Power tubes affect the overall sound but not more than the driver tubes will.



Which Power Tube would you recommend?


----------



## Johnybuchar

My current driver tube ladder:
1) Sylvania 5654W (black plates with green label)
2) Voshkod 6ZH1P-EV
3) Tesla 6F32
4) Mullard 8100
5) JAN 5654W
6) RCA 5654
7) GE 5 stars
8) Raytheon 5654

Position in ladder depends on base my daily state of mind )) however Sylvania the best all rounder! I am looking for sisters 12AX7 for Yaqin MC100MB.


----------



## Tony51

For power tubes, I settled on the sovtek 6h30p-i they put out the most power. A bit pricey at about 50-75 bucks but very good Russian made tubes.


----------



## nutsfortubes

sovtek 6h30p-i Is this a direct replacement for 6n6p tubes?


----------



## Tony51

Yes sir, I have them on my Little Dot Mk2 as we speak for 2 years now.


----------



## OctavianH

Tony51 said:


> Yes sir, I have them on my Little Dot Mk2 as we speak for 2 years now.



From the user guide:

11Little Dot MK II Power Tube RollingThe Little Dot MK II uses 6n6 power tubes by default, and these can be replaced with 6H6PI, 6H6n, 6H6n-N, 6N6P, and 6N6P-Ipower tubes*.If your circuit version is 2.0 or above, you can also use the 6H30* type power tubes (6H30EB, 6H30PI, 6H30P-DR, etc).

so check your PCB version.


----------



## Onik

OctavianH said:


> From the user guide:
> 
> 11Little Dot MK II Power Tube RollingThe Little Dot MK II uses 6n6 power tubes by default, and these can be replaced with 6H6PI, 6H6n, 6H6n-N, 6N6P, and 6N6P-Ipower tubes*.If your circuit version is 2.0 or above, you can also use the 6H30* type power tubes (6H30EB, 6H30PI, 6H30P-DR, etc).
> 
> so check your PCB version.



Is there any made in Germany Power Tubes for LD MKII? ( just not a fan of Russian made LOL)


----------



## OctavianH

I never used non-Russian powers but they are some of the best in the world, so you should not worry.


----------



## Onik (Feb 14, 2019)

OctavianH said:


> I never used non-Russian powers but they are some of the best in the world, so you should not worry.



and I never used any Russian Audio Brands in my life and I don't really like "made in Russia" doesn't sound good to me I just don't know why. maybe because Im a fan of "made in USA,GERMANY, and JAPAN "


----------



## gibosi (Feb 14, 2019)

The Little Dot was designed around these output tubes. And in fact, "made in Russia" does not imply poor quality. For example, some consider the 6H30P-DR to be among the very best double triodes available.

If you are determined to use only western tubes then you need to accept the fact that there are no suitable substitutes that are plug-and-play. All of them require an adapter of some sort. In my opinion, the 5687 is the most similar to the 6N6, 6H6 and 6H30.


----------



## mordy

Johnybuchar said:


> My current driver tube ladder:
> 1) Sylvania 5654W (black plates with green label)
> 2) Voshkod 6ZH1P-EV
> 3) Tesla 6F32
> ...


Hi Johnnybuchar,
The tube you list as #5 on your list is lacking the brand name. JAN is an abbreviation for "Joint Army and Navy" and indicates that the tube was made for military use. If the there is no name, look for a three letter designation such as CRC (RCA) or similar which will indicate the manufacturer. Also you can look for a three digit combination like 312 (Sylvania) that will also indicate the manufacturer.


----------



## Johnybuchar (Feb 15, 2019)

mordy said:


> Hi Johnnybuchar,
> The tube you list as #5 on your list is lacking the brand name. JAN is an abbreviation for "Joint Army and Navy" and indicates that the tube was made for military use. If the there is no name, look for a three letter designation such as CRC (RCA) or similar which will indicate the manufacturer. Also you can look for a three digit combination like 312 (Sylvania) that will also indicate the manufacturer.



Yes, you are right. My mistake, #5 GE JAN 5654W. I know the abbreviation. I like military tubes .


----------



## Ad720

Has anyone sprung for the telefunkens? Worth it?


----------



## Andrew LB

I'm currently in the process of getting my Little Dot MK III back in working order after being shelved about 4 years ago after i had a bit of lightning action inside a tube that had way too many hours on it. Some resistors were replaced  back then and since i didn't recall if i had used it after the repair, i decided to take out the PCB to see if everything looked good. Unfortunately two of the three Nippon Chemicon KMH 330uf 250v caps were bulging a bit and looking over the board it was clear that this thing had some pretty shoddy soldering work done when it was made with quite a few cold joints. So i ordered 3x EPCOS (TDK) 330uf 250v 10k hrs caps and while i was in there, figured i'd also replace the 2x 220uf 200v Nippon Chemicon caps with some higher quality Nichicon UCY caps, and replaced the two film caps up front with Panasonic ECQ's of similar rating. The 4x Nichicon 16v 220uf caps are being replaced by new Panasonic FR series caps of the same value. Only thing left to replace are the yellow Carli and red WIMA film caps with some better quality polyprop film caps. I've also been re-soldering the tube sockets, extended the transformer wires, improving the PCB ground connection, and making sure all the factory soldering is solid. Probably gonna get an Alps K27 100k pot for it as well.

New tubes are also on the agenda. I'm gonna start by picking up some 6n6p NOS and JAN 5654w on the cheap and once i make sure the amp is working properly, ill then consider looking into some of those tube adapters.A lot has changed since i last browsed this thread. Its good to see people still trying to improve these amps.


----------



## stuntmanx8

I am about 3 months in on my LD2. The tubes I have tried were the factory Chinese finals 6n6 with the factory Chinese drivers. The set up was moderate at best listening on my Sennheiser pxc550's.
It was better than many of my solid state rigs. Then I changed the drivers to the highly recomended GE JAN 5654w matched from riverside Audio. This really opened up the frequency response ranges.
The low end got just a tad punchier and the mids really opened up right out of the box. After about 50-60hrs on this set up, I could really hear the driver GE's set in nicely. I enjoyed this set up listening to lots of classical, jazz, electro-swing and other various EDM variants of music. 60s and 70s erra rock sounds pretty good with this combo is great.

I found what looked like a deal on some NOS russian Final 6n6p/6h6n at 10 bucks from a trade show here locally in Portland OR. These were sold as never used and tested good (not matched) however.
These had no distinguishing manufacture markings and had no box. They have only 6H6n with 11-69 under them on the glass. The filament on one of these finals is slightly dimmer than the other one, so I doubt they are a matched pair.
I feel they might be a little on the weak side, because when I crank the volume nob up passed 50 on my LD2, the sound starts to really distort. My Chinese finals wouldn't do this until the volume knob got to around 75.
The audio on these Russian 6h6n's finals sounds a little stronger on the low end with more punch. I will report back after these final tubes set in some more.


----------



## stuntmanx8

Onik said:


> and I never used any Russian Audio Brands in my life and I don't really like "made in Russia" doesn't sound good to me I just don't know why. maybe because Im a fan of "made in USA,GERMANY, and JAPAN "


I encourage you do some reading on soviet era tube manufacturing processes and quality. Especially the military version of their tubes. It was not uncommon for a builder to be executed for sub-par quality in their tubes back in the 60s and 70s.   
I have used lots of Soviet tubes in various projects over the years and would say they are on the same level as US made products. Stay away from the Chinese junk btw.


----------



## peterq

I'm curious about MK3SE, a hybrid model from little dot, anyone has experience on this model? Thanks.


----------



## Onik

peterq said:


> I'm curious about MK3SE, a hybrid model from little dot, anyone has experience on this model? Thanks.



How is it hybrid?


----------



## peterq

mk3se uses tube as driver stage only.


----------



## Tony51

stuntmanx8 said:


> I encourage you do some reading on soviet era tube manufacturing processes and quality. Especially the military version of their tubes. It was not uncommon for a builder to be executed for sub-par quality in their tubes back in the 60s and 70s.
> I have used lots of Soviet tubes in various projects over the years and would say they are on the same level as US made products. Stay away from the Chinese junk btw.



My Russian gold lion on my end game in tubes.


----------



## nwavesailor

I already have and use Siemens and Tele C3G's and like them . 

What do folks feel about the Lorenz version with the engraved top? I see them with a yellow or blue paper band near the base and wondered if indicated a production time frame or construction?


----------



## snowsurfer

Just received my LD MK2 yesterday from Shenzhen Audio, along with some GE JAN5654W driver tubes. Still very early to say but it's a completely new experience. I do not have any more "tube-friendly" cans, looking for something now, so on my low impedance AKG 551 it is probably not the best match. I use low gain and at around half volume. There is a veeeery slight hiss in the left channel, but I could swear that it was starting to disappear last night after 4-5 hours. Also, I now ordered a set of Novosibirsk 6N6P matched gold grid 1971 NOS tubes from Russia for the power section. Haven't tried the stock driver tubes and probably won't for the time being. I am thinking about getting some 600Ohm Beyer 880s for this, any suggestions on options that won't break the bank and that should play nice with tubes?


----------



## gibosi

nwavesailor said:


> I already have and use Siemens and Tele C3G's and like them .
> 
> What do folks feel about the Lorenz version with the engraved top? I see them with a yellow or blue paper band near the base and wondered if indicated a production time frame or construction?



All C3g with shiny black cans and white silk-screened lettering and graphics were manufactured by Siemens, regardless of the brand. However, the earlier embossed Telefunken and Lorenz production were actually manufactured by those companies.

The embossed Telefunken and Siemens sound very similar, with the Telefunkens having just a bit more treble presence. On the other hand, the embossed Lorenz sound much darker.

I have no idea if the color of the paper band has any significance. And unfortunately, there are no date-codes on Lorenz C3g so dating them is difficult. If they come in military boxes, then the packing date is useful, but still, they could have been in storage for months or even years before packaging. And I suppose that the serial number could be used to date them, but I am unaware of any information that correlates serial number to production date.


----------



## snowsurfer (Feb 21, 2019)

I just ordered https://www.ebay.es/itm/273431241668 as power tubes for my LD MK2. Will report back when I receive them (I reckon it will be a couple of weeks at least). Had a look at Yen Audio but the prices are just crazy. Add shipping, customs, taxes...no way.


----------



## nwavesailor

nwavesailor said: ↑
I already have and use Siemens and Tele C3G's and like them .

What do folks feel about the Lorenz version with the engraved top? I see them with a yellow or blue paper band near the base and wondered if indicated a production time frame or construction?​All C3g with shiny black cans and white silk-screened lettering and graphics were manufactured by Siemens, regardless of the brand. However, the earlier embossed Telefunken and Lorenz production were actually manufactured by those companies.

The embossed Telefunken and Siemens sound very similar, with the Telefunkens having just a bit more treble presence. On the other hand, the embossed Lorenz sound much darker.

I have no idea if the color of the paper band has any significance. And unfortunately, there are no date-codes on Lorenz C3g so dating them is difficult. If they come in military boxes, then the packing date is useful, but still, they could have been in storage for months or even years before packaging. And I suppose that the serial number could be used to date them, but I am unaware of any information that correlates serial number to production date.

*Thanks, gibosi!

I am not looking  for a darker version of the C3G so I'll stay with what I have. I don't have any of the earlier embossed Siemens or Tele's just the versions with silk screened printing. *


----------



## Tony51

snowsurfer said:


> I just ordered https://www.ebay.es/itm/273431241668 as power tubes for my LD MK2. Will report back when I receive them (a reckon it will be a couple of weeks at least). Had a look at Yen Audio but the prices are just crazy. Add shipping, customs, taxes...no way.



Keep us posted, maybe I'll upgrade to yours.
Tony


----------



## nwavesailor

Question for gibosi:

Do the embossed Siemen's sound differ from the more common shiny can w/ silk screen Siemens? My Siemens and Tele are all this later version.


----------



## gibosi

nwavesailor said:


> nwavesailor said: ↑
> I already have and use Siemens and Tele C3G's and like them .
> 
> What do folks feel about the Lorenz version with the engraved top? I see them with a yellow or blue paper band near the base and wondered if indicated a production time frame or construction?​All C3g with shiny black cans and white silk-screened lettering and graphics were manufactured by Siemens, regardless of the brand. However, the earlier embossed Telefunken and Lorenz production were actually manufactured by those companies.
> ...



Just an FYI:


----------



## gibosi

nwavesailor said:


> Question for gibosi:
> 
> Do the embossed Siemen's sound differ from the more common shiny can w/ silk screen Siemens? My Siemens and Tele are all this later version.



The older embossed Siemens and the newer shiny-black Siemens sound virtually identical. Sometimes I think the embossed are just a bit less warm, but I can't always hear the difference. So I think it is safe to say that they sound very similar if not identical.


----------



## nwavesailor

gibosi said:


> The older embossed Siemens and the newer shiny-black Siemens sound virtually identical. Sometimes I think the embossed are just a bit less warm, but I can't always hear the difference. So I think it is safe to say that they sound very similar if not identical.




Thanks gibosi! You just save me some $$$. I was going to snag the Lorenz but I am not looking for anything darker than what I have. I'm sure if embossed Tele's come up they will cost REAL money. I'm fine with the 3 pairs I have. One is supposed to be the 'S' version and they are by far the least microphonic pair I have.

Thanks again!!!


----------



## Onik (Feb 23, 2019)

peterq said:


> mk3se uses tube as driver stage only.



Is there any significant difference between LD MK3 and SE others than balanced out?


----------



## capetownwatches

snowsurfer said:


> I am thinking about getting some 600Ohm Beyer 880s for this, any suggestions on options that won't break the bank and that should play nice with tubes?



I use HD600 and DT990Pro 250. The Sennheiser is legendary, the Beyer offers lots of V-shaped fun.

HD6xx and DT880 are both excellent too. As always, try listen first.

MKII outputs 300mW into both 300 and 600 ohm. I've long wanted to try a 600 ohm headphone on mine.
One of these days...


----------



## Onik

capetownwatches said:


> I use HD600 and DT990Pro 250. The Sennheiser is legendary, the Beyer offers lots of V-shaped fun.
> 
> HD6xx and DT880 are both excellent too. As always, try listen first.
> 
> ...



I’m now trying hd600 with LD I+(JAN 5654+v5i opa installed) I find it really warm and fits perfectly to my ears. compare to ATH-R70X. But my one is made in Ireland which really disappointed me.


----------



## capetownwatches

Onik said:


> I’m now trying hd600 with LD I+(JAN 5654+v5i opa installed) I find it really warm and fits perfectly to my ears. compare to ATH-R70X. But my one is made in Ireland which really disappointed me.


Why were you disappointed? Did you expect it was made in Germany?
*ALL* HD600 are made in Ireland so do NOT be disappointed!
The quality remains excellent.


----------



## ColinMacLaren

Hi, I just bought a used LD MK III of ebay. It came with a bunch of tubes. For now, I am sticking with my own tubes, since I am a tube noob I don't wanna break something. Can someone please help me identify these?







The power tubes read 
*6Н6П 6484 - 6Н6П 6484 - 6Н6П 6484 - 6Н6П 8906*

The manual states I have to close jumpers for EF92 tubes (the ones on the left I presume?). However, there are three pins and I don't know which to I have to bridge.


----------



## Onik

capetownwatches said:


> Why were you disappointed? Did you expect it was made in Germany?
> *ALL* HD600 are made in Ireland so do NOT be disappointed!
> The quality remains excellent.



Yes I was expecting because “Made in Germany” sounds cooler
(for Sennheiser/ Beyerdynamic) than some random country imo there’s also build quality difference.


----------



## gibosi (Feb 26, 2019)

Onik said:


> Yes I was expecting because “Made in Germany” sounds cooler
> (for Sennheiser/ Beyerdynamic) than some random country imo there’s also build quality difference.



I'm glad you wrote "imo". In the end, regarding the HD600, Sendheiser sets the build quality standards. And the nationalities of the folks who actually put these together is not a factor.


----------



## snowsurfer

Onik said:


> Yes I was expecting because “Made in Germany” sounds cooler
> (for Sennheiser/ Beyerdynamic) than some random country imo there’s also build quality difference.



Wait a minute, you seem to live in the UK and consider Ireland "some random country"?


----------



## HungryPanda

snowsurfer said:


> Wait a minute, you seem to live in the UK and consider Ireland "some random country"?


 Some in the UK do not even think about Ireland, never mind other countries


----------



## Onik

snowsurfer said:


> Wait a minute, you seem to live in the UK and consider Ireland "some random country"?



as a matter of fact yes I do


----------



## ColinMacLaren

Two quick question before I break something. 

According to the guide on page 77 one doesn't have to switch the jumpers all the time in order to use Ef92 tubes.

I have three pins. So I put the jumpers like this? Or do I leave them off completely when using EF95 tubes? 






When using EF92 tubes I short the pins like this?






Thank you for your help.


----------



## Andrew LB

There's a little trick you can use which makes switching the jumper super easy. Find a suitible piece of scrap plastic and a dab of CA glue and attach the piece of plastic to the jumper so it sticks out through the access hole just a little bit. No more tweezers or jumpers rattling around inside your amp.


----------



## naillos

I've got a couple of questions if anyone is able to help me out! 

The first is whether the guys at the little dot forum are still active. I'm planning on ordering a mk3 and have emailed them a few days ago and yesterday trying to get some info but haven't gotten a reply yet. Not sure how else to contact them. Has anyone else ordered their little dot from ebay recently and have a recommended seller?

Secondly, I am fairly set on going with the Voshkod 6ZH1P-EV but (and I'm sure it has been answered) what is the opinion on going with a different power tube from the stocks off the bat? If so what is your most recent recommendation?

Thanks!


----------



## Tony51

I don't have the LD mk3 but did come off the LD Mk2 and no longer use it because I now use a real percent class A tube amp. Its the Audioromy M6v6 with Gold Lion Power Russian tubes and driver's driver's except the center driver which is a Sylvania 6n3 (5670) and the sound is so good that is actually better than all my solid state portable amps. I did a lot of tube rolling and finally settled on the above.


----------



## ColinMacLaren

naillos said:


> I've got a couple of questions if anyone is able to help me out!
> 
> The first is whether the guys at the little dot forum are still active. I'm planning on ordering a mk3 and have emailed them a few days ago and yesterday trying to get some info but haven't gotten a reply yet. Not sure how else to contact them. Has anyone else ordered their little dot from ebay recently and have a recommended seller?
> 
> ...



I don't know wether they are still active. I would buy it from a seller on ebay that has a good reputation or from amazon.

Voshkod 6ZH1P-E is a good choice. The power tubes don't make that much of a difference. Since I bought my LD3 used I don't know if it comes with Chinese power tube or with 6N1P. If in doubt I would get the 6N1P (not the 6N1P-I), they are cheap and easy to come by.


----------



## snowsurfer

naillos said:


> I've got a couple of questions if anyone is able to help me out!
> 
> The first is whether the guys at the little dot forum are still active. I'm planning on ordering a mk3 and have emailed them a few days ago and yesterday trying to get some info but haven't gotten a reply yet. Not sure how else to contact them. Has anyone else ordered their little dot from ebay recently and have a recommended seller?
> 
> ...



No idea about the official forums, but I have very good experience with Shenzhen Audio, which is where I bought my LDMK2 a month or so ago. Using rolled driver tubes (GE JAN5654W) and very happy with the sound (jazz, acoustic/vocal/unplugged, classical...). On completely silent passages I get the tiniest bit of background noise, but I am now using very low impedance/high sensivity headphones which are far from ideal for using with an OTL amp, and I suspect its the pairing, but it is only slightly noticeable when there is nothing playing, and even then it is so slight that I am not even sure I always hear it. Also, my Novosibirsk power tubes arrived this very moment from the Ukraine, I will report back after some burn in and weekend listening.

I will order those Voshkods you have this month, but I think they should be fairly similar to the GEs I have. They are so cheap that it's cool that we can try several good options without selling a kidney. As long as you don't look for the Mullard EF92s, the prices on those are a bit silly.


----------



## TrollDragon

Voskhod guys...


----------



## django1

Hi guys!  Can anyone identify this tube?  I bought it a few years ago for my LD MarkII .  They are the best sounding tubes that I have and I have no idea what they are...


----------



## mordy

django1 said:


> Hi guys!  Can anyone identify this tube?  I bought it a few years ago for my LD MarkII .  They are the best sounding tubes that I have and I have no idea what they are...


Hi django1,
I assume that these are the same:
https://www.ebay.com/itm/2PCS-6J1P-...972103?hash=item2ce6a28707:g:eAEAAOSwNSZbFlmr




Voskhod 6J1P.
Since the Cyrillic alphabet is used in Russian tube designations it can translate a little different into English, but this tube is a 6AK5 equivalent.
EV or EB designations after the tube tube designation indicate longer life - 5000 hours (compared to 3000 for a standard tube. A DR designation indicates extra long life -10,000 hours.
OTK simply means Quality Control - usually followed by a number (inspector #?).
The consensus is that earlier Russian tubes were better made than those made after the fall of communism. So if you can find a specific tube made in 50's to 70's it is possible that it may sound better than the same tube made later.
Here is a link to a chart of Russian tube makers and their trade symbols:
http://www.ominous-valve.com/russtube.html
Voskhod used a symbol of a rocket - maybe you can find it on the tube:




I used the Voskhod tubes in my LD MKIII. Very good tubes, but take an inordinately long time to burn in - around 120 hours.


----------



## django1

mordy said:


> Hi django1,
> I assume that these are the same:
> https://www.ebay.com/itm/2PCS-6J1P-...972103?hash=item2ce6a28707:g:eAEAAOSwNSZbFlmr
> 
> ...



Thanks mordy!  I never thought I would get a reply, let alone such a helpful and very well informed one.  I'm too tired to think right now but I'll be back with a few more questions and hopefully you will be around.


----------



## mordy

django1 said:


> Thanks mordy!  I never thought I would get a reply, let alone such a helpful and very well informed one.  I'm too tired to think right now but I'll be back with a few more questions and hopefully you will be around.


Thanks


----------



## snowsurfer

django1 said:


> Hi guys!  Can anyone identify this tube?  I bought it a few years ago for my LD MarkII .  They are the best sounding tubes that I have and I have no idea what they are...



On the image on the left, but on the other side of the tube, I think I see the Cyrillic letter: Ж (commonly transliterated to Zh or J). If this is the case these could be the EF95 equivalent: 6Ж1П (Sometimes referred to 6Zh1P, 6J1P, 6Zh1Pi...). They are a 6AK5 equivalent as pointed out above by Mordy. If this is what you have then you have some of the best driver tubes for your LD amp/s.


----------



## django1

snowsurfer said:


> On the image on the left, but on the other side of the tube, I think I see the Cyrillic letter: Ж (commonly transliterated to Zh or J). If this is the case these could be the EF95 equivalent: 6Ж1П (Sometimes referred to 6Zh1P, 6J1P, 6Zh1Pi...). They are a 6AK5 equivalent as pointed out above by Mordy. If this is what you have then you have some of the best driver tubes for your LD amp/s.


Thanks!  Not sure that that is good news because I just bought some tubes from Ukraine and now I'm wondering if I got the same or inferior...


----------



## mordy

What did you buy? Link to offering?


----------



## django1

mordy said:


> What did you buy? Link to offering?


https://www.etsy.com/ca/transaction/1574867889


----------



## ColinMacLaren

That link requires registration. However, these tubes are fairly cheap, widespread and easy to come by.


----------



## django1

ColinMacLaren said:


> That link requires registration. However, these tubes are fairly cheap, widespread and easy to come by.


Sorry, what about this one?
https://www.etsy.com/ca/listing/632...ak5-6j1?ref=landingpage_similar_listing_top-2


----------



## mordy

I think you did very well - the item is the right one and the price is very good (but I don't know how much shipping is).


----------



## django1

mordy said:


> I think you did very well - the item is the right one and the price is very good (but I don't know how much shipping is).



The shipping was $8.50$ and the seller seems really excellent. The tubes took a while to get here and when I mentioned that to him he refunded me right away even though I asked him to hold off.  The tubes arrived two days later...
So, I guess I could look this up myself but you guys are so good at this, are these the same tubes as the ones in my initial post?  They sure don't sound the same but maybe that is down to burn in?


----------



## django1

An additional question and this one might be a bit off topic. 

A little background first.  I seem to have this thing with speakers and headphones sounding bright to me.  I got the Little Dot about 3 or 4 years ago along with some Grado SR 80s and was non plussed.  I had no fun whatsoever listening to these and I ended up using the LD as a pre amp.  It didn't get much use because my system, although pretty good sounding, was kind of complicated.  Anyway, fast forward, in January I decided I wanted to get some good headphones.  I auditioned the Sennheisers at a high end place, models up to the 650s.  I can honestly say that not only did I not like them but I disliked them.  I actually wouldn't want any if you gave them to me.  I was nonplussed again.  So, remembering a friend's Maggies, which I liked, I did a little research to see if there was similar technology in headphones.  Long story short, I bought some Hifiman He 400i and absolutely love them.  This is the best audio purchase I have ever made.

 Ok, I'm finally at my point: everywhere I read people saying that the 400i is not a good match with the LD and to get something else to power the 400i.  But I love the sound.  There might be some background noise depending on the gain but I've listened to more music in the last two months than in the last 10 years.  Here is my question:  would I be doing better with a solid state amp (something like a Schiit)?  I would of course like better sound but I'm kind of wary that I might end up with a sound that doesn't fit my musical tastes.  I realize that this is not an easy question to answer but maybe someone, has an opinion on the subject...


----------



## django1 (Mar 8, 2019)

django1 said:


> Hi guys!  Can anyone identify this tube?  I bought it a few years ago for my LD MarkII .  They are the best sounding tubes that I have and I have no idea what they are...


Is this the box for the above tube?


----------



## snowsurfer

django1 said:


> The shipping was $8.50$ and the seller seems really excellent. The tubes took a while to get here and when I mentioned that to him he refunded me right away even though I asked him to hold off.  The tubes arrived two days later...
> So, I guess I could look this up myself but you guys are so good at this, are these the same tubes as the ones in my initial post?  They sure don't sound the same but maybe that is down to burn in?



I've purchased power tubes from that seller's shop on eBay, he is impeccable, absolutely recommended: fair prices (shipping to EU is actually free), honest, quick shipping, perfect packaging, etc. And yes, those are the "same tubes", but they will be from a different year, different spec, etc, so they can actually sound quite different.


----------



## django1

snowsurfer said:


> I've purchased power tubes from that seller's shop on eBay, he is impeccable, absolutely recommended: fair prices (shipping to EU is actually free), honest, quick shipping, perfect packaging, etc. And yes, those are the "same tubes", but they will be from a different year, different spec, etc, so they can actually sound quite different.



Thanks!


----------



## Onik

how much Electricity does LD I+ and LD MK II uses? asking because I wanna leave it turned on for 24hr so it can 100% burn-in.


----------



## DjBobby

Onik said:


> how much Electricity does LD I+ and LD MK II uses? asking because I wanna leave it turned on for 24hr so it can 100% burn-in.


From the LD MK II manual: 
_While it’s OK and even recommended to burn-in your Little Dot amplifier, it is not recommended to leave your Little Dot running 24 hours a day. We suggest for every 6-8 hours of burn-in, you allow your Little Dot to cool-down for 30 minutes to an hour._


----------



## Onik

DjBobby said:


> From the LD MK II manual:
> _While it’s OK and even recommended to burn-in your Little Dot amplifier, it is not recommended to leave your Little Dot running 24 hours a day. We suggest for every 6-8 hours of burn-in, you allow your Little Dot to cool-down for 30 minutes to an hour._



Why is it not? what can really happen if I leave it on for whole day?


----------



## DjBobby

Onik said:


> Why is it not? what can really happen if I leave it on for whole day?


I am not sure, just quoted the manual. I think it's more about the tubes life span.


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## mordy

I am also not really sure why you can't leave on the amp for extended periods, but heat builds up with extended use, and heat is enemy #1 to electronics.
Different tubes generate different amounts of heat as well, and some tubes can make the LD amps really hot.
I solved it by using a fan drawing away air from the amp. My amp was sitting on a rack and I mounted a discarded 4" PC fan above it and powered it with a 12V wall power supply.
This airflow lowered the temperature of the amp at least 10-20F and I would let the amp run for an extended time. It is always a good idea to feel the part of the transformer chassis with your hand - if it is too hot to touch it is time to give the amp a rest.
The tubes themselves are engineered to work at high temperatures. The normal life span is usually 3000 hours, with EV or EB designation tubes rated at 5000 hours. There are tubes rated at 10,000 hours as well. Tubes should last a very long time under normal operating conditions and you are more likely to loose a tube by dropping it than use....


----------



## Ad720

Hey LD friends, I sold my MKii a while back but cleaning up yesterday I found 4 standard 6n6 tubes. If anyone needs them I'd be happy to send for the cost of shipping. PM me!


----------



## dolgen

I'm having trouble with my LD MK1+ having too much gain, even in the low gain position. When the volume knob is barely turned up, most of the sound is in the right channel, and as I make it louder, the sound moves to the left. But to get the sound smack in the middle, I have to play the music too loud for comfort. 
  I'm using the WE408A tube... is there a lower gain tube, that sounds good, that I can use to solve this problem?


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## mateusfig

Didn't you think this is potentiometer issue? Or bad tube?


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## dolgen (Apr 3, 2019)

mateusfig said:


> Didn't you think this is potentiometer issue? Or bad tube?


When I switch the tubes, the slight imbalance remains. I think that lots of amps have a bad channel balance at very low volumes but resolve when used at normal volumes. The problem here is that the gain is so high, that, even with my planar headphones, the volume never gets past less than 9:00, and so the channel imbalance never completely resolves.


----------



## Whelkie D

dolgen said:


> When I switch the tubes, the slight imbalance remains. I think that lots of amps have a bad channel balance at very low volumes but resolve when used at normal volumes. The problem here is that the gain is so high, that, even with my planar headphones, the volume never gets past less than 9:00, and so the channel imbalance never completely resolves.


I use Rothwell attenuators to overcome this problem. Might be worth looking into them.


----------



## dolgen

Whelkie D said:


> I use Rothwell attenuators to overcome this problem. Might be worth looking into them.


Thanks... good idea. Kind of expensive though, as they cost about half the price of the amp itself! Do you find the Rothwells effect the sound at all?


----------



## Thenewbie76

Guys I am planning to get the little dot mk3 but I am completely new to the idea of tubes. The link at the first page to show which amps work with which little dot amp does not work. My question is since the mk3 has two input tubes and output tubes,  if I were to replace one input tube do I need to replace the 2nd input tube with the same tube as the 1st?


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## TrollDragon

dolgen said:


> I'm having trouble with my LD MK1+ having too much gain, even in the low gain position. When the volume knob is barely turned up, most of the sound is in the right channel, and as I make it louder, the sound moves to the left. But to get the sound smack in the middle, I have to play the music too loud for comfort.
> I'm using the WE408A tube... is there a lower gain tube, that sounds good, that I can use to solve this problem?


Is your source level too high, can you turn it down?


----------



## dolgen

TrollDragon said:


> Is your source level too high, can you turn it down?


Yeah, I'm using a cd player with a 2.3V output. Pretty strong. Not adjustable of course.


----------



## ColinMacLaren

dolgen said:


> Thanks... good idea. Kind of expensive though, as they cost about half the price of the amp itself! Do you find the Rothwells effect the sound at all?



You can also use an ifi Ear buddy. It is still overpriced for  such a simple circuit, but works fine.


----------



## Whelkie D

dolgen said:


> Thanks... good idea. Kind of expensive though, as they cost about half the price of the amp itself! Do you find the Rothwells effect the sound at all?


I found the Rothwells actually improve the sound. All the detail is still there but the signal to noise ratio is much better resulting in much better definition IMO.


----------



## dolgen

ColinMacLaren said:


> You can also use an ifi Ear buddy. It is still overpriced for  such a simple circuit, but works fine.


I just ordered the Ifi..... looks like a good solution. Thanks to all for the help.


----------



## gibosi

I use the Schiit SYS to adjust the output level from my DAC. And while I don't use it, the ability to switch between two inputs could be useful. It is not too expensive at $49.

https://www.schiit.com/products/sys


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## rotaspeed

might be able to get a mk2 soon so from what im seeing, almost all these tubes are the front 2 but what about the rear 2 power tubes?


----------



## nofacemonster

rotaspeed said:


> might be able to get a mk2 soon so from what im seeing, almost all these tubes are the front 2 but what about the rear 2 power tubes?



The taller tubes closer to the transformer are the power tubes. You can change the stock chinese ones to russian variant.


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## rotaspeed

nofacemonster said:


> The taller tubes closer to the transformer are the power tubes. You can change the stock chinese ones to russian variant.


 do the power tubes nakema huge difference? From my knowledge the driver tubes make the most difference


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## nofacemonster

rotaspeed said:


> do the power tubes nakema huge difference? From my knowledge the driver tubes make the most difference


Driver tubes makes the biggest difference. You are right... I got ge jan tubes and they sounds pretty good. I guess changing power tubes may have a slight difference and bigger difference is in the usage life of tubes. According to what i was told, russian power tubes last longer.


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## Whelkie D

rotaspeed said:


> do the power tubes nakema huge difference? From my knowledge the driver tubes make the most difference


Yes, the Driver (front) tubes make the most noticable difference to the sound, but I was surprised when I changed the Power tubes how much they affected the quality. I would say about 15-20% of the sound quality can be affected by the power tubes.


----------



## mat.1

is this  genuine siemens cca holly grail ?


----------



## rotaspeed

nofacemonster said:


> Driver tubes makes the biggest difference. You are right... I got ge jan tubes and they sounds pretty good. I guess changing power tubes may have a slight difference and bigger difference is in the usage life of tubes. According to what i was told, russian power tubes last longer.





Whelkie D said:


> Yes, the Driver (front) tubes make the most noticable difference to the sound, but I was surprised when I changed the Power tubes how much they affected the quality. I would say about 15-20% of the sound quality can be affected by the power tubes.



so should i even bother with upgrading the power tubes at all then?i just bought some voskhod tubes to replace the drivers


----------



## gibosi

mat.1 said:


> is this  genuine siemens cca holly grail ?



CCA = E88CC = 6922. 

Unfortunately, you are asking this question in the wrong thread. This tube is not suitable for use in the LD amps discussed here. You might want to take this to one of the Schiit Lyr tube rolling threads.


----------



## nofacemonster

rotaspeed said:


> so should i even bother with upgrading the power tubes at all then?i just bought some voskhod tubes to replace the drivers


If you already bought better tubes for power section, then by all means use them.


----------



## rotaspeed

nofacemonster said:


> If you already bought better tubes for power section, then by all means use them.


I haven't purchased any power tubes I've onkyobought the voskhod driver tubes


----------



## Acapella11

rotaspeed said:


> so should i even bother with upgrading the power tubes at all then?i just bought some voskhod tubes to replace the drivers



I found sound quality differences expressed  in percentages misleading because what does 10% mean for you and what for me? If a given sound would be just a somewhat darker or lighter or more spacious or punchier, would it then sound right? IMHO, the power tube change has enough impact in changing the sound that it is worth doing and in this thread are good suggestions as to which ones to try, so you are not fishing the dark.

Enjoy your search for tubes


----------



## snowsurfer

rotaspeed said:


> so should i even bother with upgrading the power tubes at all then?i just bought some voskhod tubes to replace the drivers



I upgraded them to the recommended Novosibirsk power tubes, and the difference is audible, but slight. They are cheap enough that I don't really mind, it is a cheap upgrade. I have a feeling that these power tubes get along better with my Voshkod driver tubes than with the GE JANs, they seem to work exceptionally well together.


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## Johnybuchar (Apr 25, 2019)

Woooow i have recently replaced drive tubes back to 5654 GE 5star and i have absolutely fallen in love with them. I'm not sure if they burnt-in themselves but their organic sound is amazing! I highly recommend them and look for 5751 5star for my Yaqin .


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## nofacemonster (May 13, 2019)

I am already using GE JAN 5654W with Little Dot MKII and HD-6XX. I am thinking of giving Mullard CV4010 a try. When i go to eBay, it says "RING GETTER" and "SQUARE GETTER". Which tubes should buy...? i don't know what it means by "Square and Ring Getter"....! which one sound the warmest...? i am lost in there now.


----------



## Johnybuchar

Mullard sounds definitely warmer and fuller than GE JAN 5654W but a little bit tight soundstage at least in my audio system. I like Sylvania 5654W (green printing) - details, top ends, glad mids, amazing soundstage and "silence between notes" .


----------



## gibosi

Ring getters were introduced around 1960, replacing square getters. Ring getters were cheaper to manufacture and further, they did a better job of keeping the getter splash away from the other internal components. However, tubes with one style of getter do not necessarily sound better than the other. For most of us, the most important thing about getter style is that it simply helps in dating tubes.

That said, it might be that tubes manufactured prior to 1960, with square getters, might sound different than those manufactured later.


----------



## nofacemonster

gibosi said:


> Ring getters were introduced around 1960, replacing square getters. Ring getters were cheaper to manufacture and further, they did a better job of keeping the getter splash away from the other internal components. However, tubes with one style of getter do not necessarily sound better than the other. For most of us, the most important thing about getter style is that it simply helps in dating tubes.
> 
> That said, it might be that tubes manufactured prior to 1960, with square getters, might sound different than those manufactured later.



Thank you for the clarification. So I think I should get the ring getter since they might last longer.


----------



## nofacemonster

Johnybuchar said:


> Mullard sounds definitely warmer and fuller than GE JAN 5654W but a little bit tight soundstage at least in my audio system. I like Sylvania 5654W (green printing) - details, top ends, glad mids, amazing soundstage and "silence between notes" .



I am actually planning on buying Mullards mainly because of curiosity. I already have GE JAN5654W. According to you, it should sound fuller and warmer than GE's but soundstage will be tighter. Well first news is pretty good but i don't want the soundstage to get narrower than what it is now with my HD-6XX. I kind of enjoy the current soundstage even though it is like in a room and very intimate, i don't want it to be in my head.


----------



## gibosi

nofacemonster said:


> Thank you for the clarification. So I think I should get the ring getter since they might last longer.



No, they will not last longer. The getter type has no affect on how long a tube will last. IMO, you should ignore the getter type. Instead, you should read the reviews and get tubes that will sound best with your ears and gear.


----------



## nofacemonster

I am planing on getting Mullard CV4010 to replace Ge JAN5654W on my LD MKII. (I use a HD-6XX), The improvement in bass and mids will be noticeable or very subtle...? the whole purpose of getting the mullards is to improve the bass department and increase the overall warmth in sound.


----------



## nofacemonster

I just did a bit of tube rolling back and forth then figured out something strange with my Little Dot MKII amplifier. I am using a HD-6XX with it and FX Audio DAC-X6 (as a dac). I upgraded the stock tubes with Russian power tubes (Matching) and GE Jan5654W (Matching - Green letters) about three months back and i was listening as usual. Things were all good and today i thought of switching back and forth with DAC-X6 and Little dot to see because when i bought the little dot with stock tube there was a clear night and day like difference (Little dot in a good way). But today i noticed that DAC-X6 sounded much better with better low end bass etc. I decided to do this because i really felt something is lacking in my little dot.

Then as a solution i put the stock tubes back. Suddenly the LD MKII is back where it was, i can't believe for the life of me that these Chinese tubes were better sounding with more power in the bass than Russian + GE Jans combines. So for the testing purposes i left the chinese power tubes and changed it back to 5654 and the sound became less bassy to me.Then i tried the Russian power tubes and Chinese 6J1 (Stock) and there wasn't much to notice but still good bass and when i put all the chinese tubes back the sound was damn good.

Why is this...? is something wrong with my ears or the tubes? Does GE Jan 5654W sounds less bassy than chinese 6j1?

I am not sure how many hours i have used the GE and Russian tubes so far, maybe they need longer break in time...? i think i have probably use them maximum of 30 hours or so during last month or two. Does this mean they need burn in time and things will get better afterwards.....?

I don't have any other tubes to try on because i am new to this.

please shed some light on this matter.


----------



## sevenbrides (May 27, 2019)

It is my first intervention in this forum, but I have been following it for some time.
I want to congratulate *Acapella11* for the very beautiful table posted in pg 77 of this thread (table which I recently discovered), but I do not agree with the placement of the *Shuguang 6K4 *tube in the 6BA6 family.

 In fact it appears from the datasheet of Shuguang 6K4 (in Chinese) as for the similar Russian 6K4P and 6K4P-EV tubes that both pins 2 and 7 are both already connected to cathode, grid (3) and screen, just like for the 6j1 ( 6j1p-EV etc).

So you don't really need the recommended connection between pins 2 and 7.
In my opinion it is enough to simply use the tube with jumper in position E95.

I will be very grateful to those who will kindly provide me with some information on the audio performance of Shuguang 6k4, 6K4P and 6K4P-EV maybe compared to the Russian Voskhod 6j1P-EV tube that I know very well.

Thanks, see you.


----------



## sevenbrides (May 27, 2019)

for *nofacemonster* * "don't have any other tubes to try on because i am new to this.please shed some light on this matter."
*
I have several preamplifiers with both valves and solid state and I have since bought a Little Dot MKii that I took out of curiosity and tried to compare (as buffer-preamplifier) with my others.
 Little Dot with *6j1 chinese* in stock sounds pretty good but I expected a lot more.
 It's definitely improved by changing the tubes with* Voskhod (rocket) 6j1p-EV, * even if at this time (as a buffer) I still prefer others 3-4 my tube preamps also  less expensive.
 But we can't talk about these because the topic of this thread is *Rolling tubes for  the LIttle Dot used as a headphone amplifier*.
But even as a headphone amplifier the use of the Voskhod 6j1p-EV  (gold pins and not) has clearly improved the tone in general and the soundstage for which I recommend them without a doubt.
 Instead the change of the Chinese power tubes with the 6N6 Russians brought very small changes.
 Now I have ordered others tubes recommended in this forum by experts like *Acapella11* or *Gibosi* or *AudiofanBoy*  (and others)  like *GE 6AU6WA , 6J5P*
 and I want to try them to see if I can improve this very famous Little Dot, but for now quite behind three or four my others terrible " tube toys".


----------



## nofacemonster

I see plenty of 6j1p russian tubes available online for cheap price and they are voshkods. Then there is this 6j1p-ev tubes which are expensive. Are they same or two different tubes? They looks physically identical to me.


----------



## warp2600

nofacemonster said:


> I see plenty of 6j1p russian tubes available online for cheap price and they are voshkods. Then there is this 6j1p-ev tubes which are expensive. Are they same or two different tubes? They looks physically identical to me.


AFAIK the -ev extension means military grade i.e. manufactured to stricter specs and made to last longer.


----------



## mordy

warp2600 said:


> AFAIK the -ev extension means military grade i.e. manufactured to stricter specs and made to last longer.


Regular tubes are supposed to last 3000 hours; EV tubes 5000 hours and DR tubes 10000 hours. IR tubes have a shorter rated life span, but probably predicated on severe use in military applications. All the above designations only apply to Russian tubes.
For all practical purposes I doubt that anyone will wear out these tubes in their amps.


----------



## sevenbrides

nofacemonster said:


> I see plenty of 6j1p russian tubes available online for cheap price and they are voshkods. Then there is this 6j1p-ev tubes which are expensive. Are they same or two different tubes? They looks physically identical to me.



I not many used the Little Dot as a headphone amp, but as a buffer I can say that the 6j1 Chinese stock tubes are not bad but they have less bass with important mid-highs The Russian 6J1Ps improve the bass, the detail and the soundstage and finally the 6jP- EV, which have versions with richer platinum and gold grids (in traces ..), have a warmer and more full-bodied response with powerful bass, very natural voices and crystalline and airy highs, never harsh. Also soundstage and dynamics are very good. I thought they were the best tubes in the 6J1 family.
Audiofanboy and others put the 6J1P-EV in the A or B category. I'm curious to try the A +++ and A ++ category tubes I ordered.


----------



## BreadFi

I've owned a LD MKIII for many years now, and purchased a 1+ hybrid a couple of months ago to try some tubiness with my low impedance 32 ohm DT770 (and for some volume to my DT880s in the lounge room).
It's interesting how the tubes tone translates across both amps - seems kind of obvious, but it sounds how you'd expect a hybrid tube/solid state amp to.
I'm using my preferred GE JAN 5654 (fat sounding and gives rock snares a nice crack), the stock 6j1 sounded pretty good (clean, not so much bottom end though). I still don't like the Mullard 8100's with the Beyers (highs not so smooth).
I'm a bit disappointed with how it plays with the DT770's though, bass becomes very loose. Not sure if it's just the characteristic of the tube or if the amp is still too high impedance for them (doesn't seem particularly loose on the 250ohm '880's). Would anyone happen to know the output impedance of the 1+?


----------



## cheungtsw

I am torn between MK3 and Valhalla 2.
Seems Valhalla 2 has much less choices in tubes but some says Val 2 is a much better amp.

Any opinions?

ps. I am currently using the FX audio tube 3 with GE JAN5654W as tube buffer.


----------



## sevenbrides

A matched pair of GE 6AU6 (rank A ++ for this thread's experts) has arrived. 4 hours of burn and then spectacular sound! 
Powerful and tight bass, high mid-range presence, very detailed highs, crystal clear and airy.
Excellent dynamics and soundstage. Absolutely awesome! 
But after a bit of listening the voices also seem too forward and overbearing and the general tone is very engaging but sometimes too aggressive. 
They are certainly the best for headphones (or amp + boxes) rather relaxed but with my components after a while a bit of listening effort comes. 
Of course, they are NOS tubes never used and, after only 4 hours of burning, these are only my initial impressions. 
If the GE 6AU6 (as I hope) will calm down a bit we are very close to the top, but for now I have decided to rest a bit by switching the output of my audio DVD player to other less aggressive buffers. Then I will resume the burning (with great pleasure).


----------



## sevenbrides

cheungtsw said:


> I am torn between MK3 and Valhalla 2.
> Seems Valhalla 2 has much less choices in tubes but some says Val 2 is a much better amp.
> 
> Any opinions?
> ...





 Also have an FX tube 03 (with controls) and FX tube 01 in my buffer collection.
 They sound pretty good, but to improve them I replaced the stock 6j1 Chinese tubes with the Russians 6j1P-EV
 which in other buffers (including Little Dot MKii) work wonders.
Instead with both buffers FX did not change practically nothing.
So I put the stock tubes back!
 If you want to buy an inexpensive but absolutely exceptional buffer I recommend the Matisse Guanzo by mounting two GE 5670 tubes.
It's a bomb with a sublime sound! Better than buffers that cost hundreds of euros (which I tried)!


----------



## nofacemonster

sevenbrides said:


> I not many used the Little Dot as a headphone amp, but as a buffer I can say that the 6j1 Chinese stock tubes are not bad but they have less bass with important mid-highs The Russian 6J1Ps improve the bass, the detail and the soundstage and finally the 6jP- EV, which have versions with richer platinum and gold grids (in traces ..), have a warmer and more full-bodied response with powerful bass, very natural voices and crystalline and airy highs, never harsh. Also soundstage and dynamics are very good. I thought they were the best tubes in the 6J1 family.
> Audiofanboy and others put the 6J1P-EV in the A or B category. I'm curious to try the A +++ and A ++ category tubes I ordered.



Today I received the matched pair of Mullard CV8100 I ordered a couple of weeks back. I totally fell in love with the Mullard house sound within the first few minutes of listening. Probably the best sound I ever heard in my life. Laid back, warm, so smooth I haven't got the right words to describe it. Like many audiophiles and experts say the sound is something personal, it is different from person to person and I guess I just found the sound I am looking for.

Right now I am listening to "Gerry Mulligan - The Art of Gerry Mulligan (Final recordings)",

I think my journey to find the perfect sound that could please me 100% has come to an end with Mullards on the MKII.


----------



## T3RIAD

Does anyone know if the Little Dot 1+ and the MK III SE use the same tubes?

I'm currently using the 1+ with WE408A tubes and love the sound, but I'd like to upgrade to something with balanced output. The MK III SE is also a hybrid amp, so it looks like it might be what I need.

Would the same tubes work?


----------



## BreadFi

T3RIAD said:


> Does anyone know if the Little Dot 1+ and the MK III SE use the same tubes?
> 
> I'm currently using the 1+ with WE408A tubes and love the sound, but I'd like to upgrade to something with balanced output. The MK III SE is also a hybrid amp, so it looks like it might be what I need.
> 
> Would the same tubes work?



1+ (and regular OTL mk III) uses 7 pin 5654 etc, looks like the III "SE" uses 9 pin tubes.


----------



## abman

nofacemonster said:


> I see plenty of 6j1p russian tubes available online for cheap price and they are voshkods. Then there is this 6j1p-ev tubes which are expensive. Are they same or two different tubes? They looks physically identical to me.


Yes they are the "same" by the overall construction, but there are some differences:

The prefixes on the Russian tubes means (Google translate):
V (Cyrillic "B") - tubes of increased reliability and mechanical strength;
D (Cyrillic "Д") - tubes of special durability with guaranteed operating time of more than 10,000 hours;
E - tubes of increased durability with guaranteed operating time of more than 5000 hours;
I (Cyrillic "И")  - the tubes intended for work in the pulse mode; characterized by increased emissivity of the cathode;
K - tubes with high vibration resistance;
R (Cyrillic "Р") - tubes of special reliability and mechanical strength;
So we can understand like:
- EV (Cyrillic "-ЕB") - tubes of increased reliability, mechanical strength and durability (5000 h);
- DR (Cyrillic "-ДР") - tubes of special reliability, mechanical strength and durability (10000 h).
...and so on


----------



## nofacemonster

abman said:


> Yes they are the "same" by the overall construction, but there are some differences:
> 
> The prefixes on the Russian tubes means (Google translate):
> V (Cyrillic "B") - tubes of increased reliability and mechanical strength;
> ...


 
Thanks for the clarification. So it doesn't effect the sound quality right? Just longevity.


----------



## abman (Jun 27, 2019)

nofacemonster said:


> Thanks for the clarification. So it doesn't effect the sound quality right? Just longevity.


I have not yet had the opportunity to compare directly, but I think there "may be" difference (thinking logically there should be some differences in construction, for example - cathode to provide 5,000 working hours (-EV version) instead of 2000 (original 6J1p)) - your ears will tell you exactly


----------



## mordy

The DR versions of the 6N6P (6H30P etc) are priced very high, and there are some differences in how they sound, but not justifying the high price IMHO.
The IR version of the 6N6P sounded the best of the less expensive ones.
For all practical purposes I can't remember wearing out a tube from use. I have heard of some people using other kinds of tubes for 10 years before they replaced them.
Some of the ratings regarding vibrations resistance etc applies to military applications (tanks, jets) and not the regular situation in somebody's home. But more support rods and more rugged construction could impact the sound - less microphonics etc.


----------



## abman (Jun 28, 2019)

mordy said:


> Hi DonLuca,
> 
> Please let us know if there is a difference with the gold 6J1p-EV compared to the non-gold variants once they arrive.
> .......................................
> ...


Someone may have written about this before, but however I will clarify what I know from here, on this side of the iron curtain:
1) Inside the tubes is NOT a gold grid (!!!). An alloy of gold and platinum is applied to the grid. In the amount of 0.259 mg. Sorry guys that so not much 
2) The fact described in clause 1. is part of the technological requirements of the production process of ALL AND ANY TUBE 6ZH1P-EV at all plants throughout the USSR. So it could not be produced these tubes WITH GOLD grids (!!!). THEY ALL HAVE GOLD AND PLATINUM ALLOY ON A GRID. And other options for these tubes simply can not be.
So forgive me guys, but it looks like you were wasting your time listening to tubes with a “golden grid” and “not a golden grid”.
Yes, there is certainly a difference in the sound, but perhaps for other reasons, independent of the grid material, since it is the same for everyone.
...as I know....
may be later I will add some


----------



## mordy

As far as I know GE was the inventor of the gold grid, but they never made any effort to use it in advertising. The amounts are minuscule.
My impression of the OTK stamp, which is always followed by a number, is that it a quality control stamp followed by an inspector number.


----------



## abman (Jun 28, 2019)

mordy said:


> As far as I know GE was the inventor of the gold grid, but they never made any effort to use it in advertising. The amounts are minuscule.
> My impression of the OTK stamp, which is always followed by a number, is that it a quality control stamp followed by an inspector number.



from my post at diyAudio forum:

"As I know:
*"OTK"* - sign of QC department, means that standard quality control passed. In the Soviet times ANY PRODUCT of ANY factory or other production MUST BE checked by "OTK" department - it was guaranty to civil buyers/users that this device is good and safe for use. It is *"civil"* sign.

*"<>"* empty rhombus or rhombus with only digits inside (since last '60-s - till present), also letters *"ВП"* and some two digits between them and inside rhombus - like "*<В 171 П>*" (before last '60-s) means that device passed *Military quality control *.
As I can find, digits inside rhombus *does not mean* any special concerning tube parameters - it's just personal provisory number of person who control QC process for military.

Rhombus signs also used and uses now for any other electronic components and devices which pass QC for military uses.

Sign like star and "CCCP" inside pentagone - is "Sign of Highest Quality USSR" - civil sign.
Words "Сделано в СССР" - means "Made in USSR"......."
Also I have one tube from '60-s which have very old Military Q control sign - letters "ВП" + digits (military QC inspector personal number) inside the star - I need to find it, will make photo and then post here.


----------



## mordy

abman said:


> from my post at diyAudio forum:
> 
> "As I know:
> *"OTK"* - sign of QC department, means that standard quality control passed. In the Soviet times ANY PRODUCT of ANY factory or other production MUST BE checked by "OTK" department - it was guaranty to civil buyers/users that this device is good and safe for use. It is *"civil"* sign.
> ...


Hi abman,
Somehow I thought that all Russian tubes were military production.....


----------



## abman (Jun 30, 2019)

mordy said:


> Hi abman,
> Somehow I thought that all Russian tubes were military production.....



Hi Mordy,

You can easily find out some Russian tubes with OTK sign, but without <> rhombus sign - this is the tubes made for civil purposes only, or maybe the tubes which did not pass hard parameters military QC.


This does not mean that they are "bad" or "worse" than the diamond tubes, maybe they just have a slightly larger variation of parameters than military requirements allow (maybe the tube did not fit into military requirements of only 1 milliampere, by ear you will never hear it, but the controller
 cannot miss it according to indications of devices),
And it certainly does not say that they sound "worse" than a diamond tube.


----------



## mordy

Thanks for the information.
Did they use different designations for the same tube for military vs civilian tubes?
6H13C vs 6N5P?


----------



## abman

mordy said:


> Thanks for the information.
> Did they use different designations for the same tube for military vs civilian tubes?


As I know, not. the presence of a rhombus sign indicates military suitability.


mordy said:


> 6H13C vs 6N5P?


I'm not a big tubeworm, as I can see 6H13C is the Russian and 6N5P - Chines made
What is the question?


----------



## Datun Walnut

Over the past few weeks I've been trying all sorts out in my MkII.
Finally settled on a pair of CV4014s and a pair of 1959s Sylvania 6SN7GTs with adaptors. My cans are quite old Beyer DT44Os (600ohm 1980s vintage). Now they've fully warmed up,  I feel the gain on the power tubes is a bit lower. That being said, the bass is really detailed and crisp. And the sound in general had opened up in a way, I don't really understand. Highs are not overpowering and vocals sound gorgeous.


----------



## sghound

Datun Walnut said:


> Over the past few weeks I've been trying all sorts out in my MkII.
> Finally settled on a pair of CV4014s and a pair of 1959s Sylvania 6SN7GTs with adaptors. My cans are quite old Beyer DT44Os (600ohm 1980s vintage). Now they've fully warmed up,  I feel the gain on the power tubes is a bit lower. That being said, the bass is really detailed and crisp. And the sound in general had opened up in a way, I don't really understand. Highs are not overpowering and vocals sound gorgeous.



i have almost the same config on the mk2. in place of the sylvies are a pair of cbs 5962 triple mica brown base.

i swapped out the siemens c3s for the cv4014 and they sound way better. as u described it the vox rocks.

running the 600ohms beyer 880 effortlessly


----------



## Onik

sghound said:


> i have almost the same config on the mk2. in place of the sylvies are a pair of cbs 5962 triple mica brown base.
> 
> i swapped out the siemens c3s for the cv4014 and they sound way better. as u described it the vox rocks.
> 
> running the 600ohms beyer 880 effortlessly



Which Adapter did you buy for the power tubes? Is it just plug and play with the adapter or you have to swap the pins inside mkii?


----------



## marcomalaca

nofacemonster said:


> Today I received the matched pair of Mullard CV8100 I ordered a couple of weeks back. I totally fell in love with the Mullard house sound within the first few minutes of listening. Probably the best sound I ever heard in my life. Laid back, warm, so smooth I haven't got the right words to describe it. Like many audiophiles and experts say the sound is something personal, it is different from person to person and I guess I just found the sound I am looking for.
> 
> Right now I am listening to "Gerry Mulligan - The Art of Gerry Mulligan (Final recordings)",
> 
> I think my journey to find the perfect sound that could please me 100% has come to an end with Mullards on the MKII.



can you share the link where you got the tubes. thanks


----------



## nofacemonster

Got it off the ebay. Just search mullard cv8100


----------



## nofacemonster

marcomalaca said:


> can you share the link where you got the tubes. thanks


Got it off the ebay. Just search mullard cv8100. You will get plenty.


----------



## mordy

marcomalaca said:


> can you share the link where you got the tubes. thanks


Hi marcomalaca,
CV means Common Valve (civilian use) as opposed to the M designation which means Military.
Searching for CV8100 on eBay I did not get any hits, but many for M8100. You can also look for Mullard E95 which is another designation for the same tube.
Other Mullard designation for the M8100 is CV 4010 and also CV850, but the last tube is harder to find.
I admit that it is confusing with all these designations for the same tube. Think of synonyms or the same word in different languages. US made tubes of this type could be called 6AK5, 5654, not to mention Czechoslovakian 6F32 and various Russian designations such as  6Ж1П and 61JP etc. And there are more....
One seller called this small tubes "peanut tubes"!


----------



## marcomalaca

mordy said:


> Hi marcomalaca,
> CV means Common Valve (civilian use) as opposed to the M designation which means Military.
> Searching for CV8100 on eBay I did not get any hits, but many for M8100. You can also look for Mullard E95 which is another designation for the same tube.
> Other Mullard designation for the M8100 is CV 4010 and also CV850, but the last tube is harder to find.
> ...



thanks!


----------



## westsounds

Hi I have a little dot tube amp already and really enjoy using it. I am thinking of getting another valve pre amp though and I see there are ones which use 6J2 tubes as well. Can anyone tell me please if 6J1 and 6J2 tubes are compatible?


----------



## Datun Walnut

Onik said:


> Which Adapter did you buy for the power tubes? Is it just plug and play with the adapter or you have to swap the pins inside mkii?


  On ebay I searched for: 6SN7 TO 6CG7 6FQ7


----------



## westsounds

Hi All

Anyone tried any of these Little DOT tube rolling kits. Really dont want to modify my unit just plug and play tubes. Just wondering if these kits are any good?

https://www.ebay.co.uk/itm/252130624590 

https://www.watfordvalves.com/product_detail.asp?id=4842

Any suggestions greatly appreciated.


----------



## HungryPanda

The first link uses the very tubes I am using


----------



## westsounds

HungryPanda said:


> The first link uses the very tubes I am using



And, are you a happy Panda 

In other words do you like them?

Give us some superlatives then


----------



## westsounds

A new site just opened and the owner who was very helpful so far tells me

'We specialise in the USSR Russian Military ruggedized Originals since 2007 as they are the exact (but far Superior) vacuum tube that the Chinese 6N1 & 6N6 are based on. Because of that fact they tend to perform very well indeed.'

https://www.audiozomba.com/product-category/vacuum-tubes-for-sale/nos-tubes/little-dot-vacuum-tubes/


----------



## HungryPanda

Those sound very good with the headphones I use with a tube amp. I prefer them to the mullard set up. More lively sounding.


----------



## westsounds

HungryPanda said:


> Those sound very good with the headphones I use with a tube amp. I prefer them to the mullard set up. More lively sounding.



Interesting.

And Wow Panda I just clicked the link to your gear! That is some impressive list, you are a top dog (or Panda) with regards to collector status.


----------



## marcomalaca (Oct 13, 2019)

hi guys,
Im in the market for power tubes on the little dot mk3.
Currently have the Voshkod 6ZH1P-EV for preamp tubes.
What is the difference between 6H6P-I and 6N6P-IR in sound signature?
which one would you think will go well with my current tubes and hp (hd660s).


----------



## abman

westsounds said:


> Hi I have a little dot tube amp already and really enjoy using it. I am thinking of getting another valve pre amp though and I see there are ones which use 6J2 tubes as well. Can anyone tell me please if 6J1 and 6J2 tubes are compatible?


Hi, as I can find not - 6J2P gives almost twice less power than 6J1P


----------



## cirodts

I have a mini t20 audio amp that brings the 6j4s as "pentodi" tubes I have replaced with g5654 "triodes", I always hear a less powerful speaker than the other, do you think it may depend on what?

are the 6j4 not compatible with the ge 5654? can the amp be broken if I use the gs 5654 instead of its 6j4?


----------



## daniboun (Oct 29, 2019)

Hi amigos,

My name is Danny, I've been living in Lyon (South of France). I have been playing drums for 20 years and my father is a classical guitarist.
I want to share my quick review about some Tubes I tested, from Triode to Heptode.  Keep in mind that this is not a review based on scientific measurements but a test based musician's ear.

My Setup :
-Pair of DACS 25 Hi End floor speakers handmade in France, 2.5 Way.
-Audio source : HD Audio 24 bit : Classical music / Blues femal + male voices / World Music
- Audiophonics high end A/B Amplifier
-  P1 DK Preamplifier Tube QCC3008 Aptx + CM6642 chip + NES5532 AOP + Little Dot Tube


*6HM5  NOS Yougoslavia TRIODE :
*








These triodes are made in Yougoslavie by Elektronska Industrija for Mullard / Philips). Out of the box they immedialty sound fantastic. They are very linear, ultra low noise = dead silence between songs
I found of these tubes something really unique, they are accurate, plenty of details.  balance between Bass / Medium and Treble is absolutely incredible. 3D Image / Sound stage are seplendid as well. But what struck me the most is how the pianos recordings stand out ! I can really feel the difference between my others tubes of these ones when I listen to pianos.


*5654W GE JAN PENTODE :
*







These pentode are made by General Electric in the USA. These are sepcially made for HIFI amplifier and stamped as JAN / Military grade.
Out of the box, they sound great with a very low noise.  I found them very linear as well with a great 3D image. They are less detailed than the 6HM5 Nos / Yougoslavia. They remains nevertheless, very precise, sweet and warm.


*6AH6WA Sylvania NOS Pentode
*







These Pentode are made in the USA and they are Military grade tubes.
Before I listen to the 6BE6W; these tubes were my favorites. Out of the box, you can feel a real "sound signature". They inflate the bass so very soflty and Medium + Treble still sound really great and detailed.  They are more powerful than my 6HM5, I need less gain to feel the consistency of the tubes. I noticed thath they were heating up a lot....


*6BE6W  Brimar CV4012 Heptode
*







These Heptode were made in UK by Brimar. (I see 1968 stanmped into the packaging).  Out of the box they sound AWESOME !  Not too boomy, voices and instruments are perfecty distinguished when listening. These tubes are surgical and all the micro details are audible.
Someone wrote a review about the Fivre 6BE6 on page 140, and I share his point of view about 6BE6 tubes, they have something magical, it's like the tubes have been filled with steroids lol )
THESE are the tubes to get ! Next review = Sylvania 6BE6W  made in the USA.


----------



## cirodts

Hi, but if I insert the 5654 instead of the 6j4 can I break the amplifier being a triode and the other pentode?


----------



## daniboun

cirodts said:


> I have a mini t20 audio amp that brings the 6j4s as "pentodi" tubes I have replaced with g5654 "triodes", I always hear a less powerful speaker than the other, do you think it may depend on what?
> 
> are the 6j4 not compatible with the ge 5654? can the amp be broken if I use the gs 5654 instead of its 6j4?



Don't get me wrong : but 5654 = 6AK5W are pentode tubes... not triodes.


----------



## willne1

Do the jumpers need to be changed or the 6BE6 tubes? I'm on the default EF95


----------



## gibosi

cirodts said:


> Hi, but if I insert the 5654 instead of the 6j4 can I break the amplifier being a triode and the other pentode?



The 6j4s is a triode. The 5654 is a pentode. It is not a good idea to use 5654 in your amp.


----------



## cirodts

thanks this I wanted to know, I will take a fx audio 01 for the ge 5654.


----------



## daniboun

cirodts said:


> thanks this I wanted to know, I will take a fx audio 01 for the ge 5654.



6BE6W will sound far away better on a FX Audio 01..... I own it and have both tubes...


----------



## willne1

willne1 said:


> Do the jumpers need to be changed or the 6BE6 tubes? I'm on the default EF95


NM, I found my answer on page 77.


----------



## TrollDragon

willne1 said:


> NM, I found my answer on page 77.


This post here has a chart of which modes to use compatible tubes in.
https://www.head-fi.org/threads/lit...ube-rolling-guide.563884/page-77#post-9392055


----------



## willne1

TrollDragon said:


> This post here has a chart of which modes to use compatible tubes in.
> https://www.head-fi.org/threads/lit...ube-rolling-guide.563884/page-77#post-9392055


Thanks TrollDragon, pretty confusing for me I should probably just forget it.


----------



## cirodts

daniboun said:


> 6BE6W will sound far away better on a FX Audio 01..... I own it and have both tubes...


Is the coupled fx audio 01 good with this?
https://www.amazon.it/gp/product/B07KPSYHWF/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1


----------



## daniboun (Oct 30, 2019)

cirodts said:


> Is the coupled fx audio 01 good with this?
> https://www.amazon.it/gp/product/B07KPSYHWF/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1



I have 4 class D amp, and trust me, go for this one !  TDA7498E chip is awesome and works fine with FX 01.  This audio chip is far away better than the TPA3116.

https://www.amazon.fr/gp/product/B07T5KFJXM/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1

This AMP is absolutely crazy, very powerful and the soundstage is excellent ! Moreover you will find on it high ends capacitors and a QC3008 APTX LL Bluetooth chip which is awesome.

If you have a little more budget, go for this one, the TPA3250 is a crazy Purepath chip !

https://www.amazon.fr/gp/product/B07WCTX7MX/ref=ppx_yo_dt_b_asin_title_o04_s00?ie=UTF8&psc=1

Then, change the OPA NE5532 and get a pair of LME49720NA ($10)  on it : you'll have a great Amp that performs as well as a $1000 amp )  See my review on Amazon.fr and the pictures I put )
For $70 only you have THE AMP !

And to finish : If you need a very very great Tube Preamp, go for this one.
The DK P1 with some goods 6BE6W valves works far away better than the FX Audio 01
I own both... and Have been testing lots of Tubes on it )

https://www.amazon.fr/gp/product/B07TMZ8G7H/ref=ppx_yo_dt_b_asin_title_o02_s00?ie=UTF8&psc=1

PS : Another secret if you want to get all the befenit of your Tubes, change the DC Power Supply. Leicke Power Supplies will provide you very great results !
Example a 12V @6A Leicke (Germany) Power Supply will perform very very well with the FX Audio Tube 01 or DK P1.  This is the same for any Class D Amp... A Stable Wattage is very important.


----------



## cirodts

you have been very kind for your explanations, mine
Breeze Mini Dual TPA3116 because it is not good compared to the TDA7498E?
Easy to change op amps, are they interlocking?


----------



## daniboun (Oct 30, 2019)

cirodts said:


> you have been very kind for your explanations, mine
> Breeze Mini Dual TPA3116 because it is not good compared to the TDA7498E?
> Easy to change op amps, are they interlocking?



I just prefer the TDA7498E over the TPA3116... TDA is better, more detailed, more powerfull and offers lower distortion.
TP3250 is my reference for Class D amps. on the model I suggested you, the OPA is really easy to switch, a kid could do it ) (removable OPA)


----------



## cirodts

Thanks, TP3250 better than the TDA7498E?


----------



## daniboun (Oct 30, 2019)

cirodts said:


> Thanks, TP3250 better than the TDA7498E?



I would say, better with the LME49720NA AOPs.  But keep in mind that if you drive some 8 ohm Speakers or some powerfull Floor speakers, the TDA7498 will fit better (160W vs 50W)

What is your budget ?


----------



## cirodts

My speakers are klipsch r51m 93db sensitivity, do you think that Breeze Mini Dual TPA3116 will be enough?
Is the TDA7498 too powerful for my speakers?


----------



## daniboun

cirodts said:


> My speakers are klipsch r51m 93db sensitivity, do you think that Breeze Mini Dual TPA3116 will be enough?
> Is the TDA7498 too powerful for my speakers?



klipsch r51m are 8 ohms speakers, go for the TDA7498 without any doubt ) You won't be disappointed.


----------



## cirodts

I forgot, I have to pair it with a fx audio tube 01 better in this case the tpa or tda.


----------



## daniboun

cirodts said:


> I forgot, I have to pair it with a fx audio tube 01 better in this case the tpa or tda.



I definitively prefer the TDA in any case )


----------



## cirodts

I will buy the tda, in the meantime I recommend the best op amp for my tpa 3116d2.


----------



## Acapella11

cirodts said:


> I will buy the tda, in the meantime I recommend the best op amp for my tpa 3116d2.


Hey guys, great that you share  an in interest in class D amps and op amps but this is a tube rolling thread and it is off topic. Please have your correspondence in private messages or another thread. Cheers


----------



## daniboun

Acapella11 said:


> Hey guys, great that you share  an in interest in class D amps and op amps but this is a tube rolling thread and it is off topic. Please have your correspondence in private messages or another thread. Cheers



Sorry that's right ! We will go on via private message )


----------



## NYGator (Nov 4, 2019)

Long story, short punchline/questions from an amateur audiophile.  I purchased a little Dot MKii about 5 years ago and initially changed out the stock tubes and replaced them with 2x Voshkod 6ZH1P-EV and 2x Novosibirsk 6H6P-I.  I never wound up using the amp all that much because I had ground loop issues and I must not have explored solutions at the time or realized they existed.  I recently became interested again and solved the loop issue with a device I found on Amazon that worked real well.  (If someone thinks there is a better solution I would appreciate it, but this removed the static and did not appear to interfere with the sound quality.)

https://www.amazon.com/gp/product/B01L1NP7YI/ref=ppx_yo_dt_b_asin_title_o05_s00?ie=UTF8&psc=1

I also just acquired a Dragonfly Cobalt and I got the Little Dot sounding really good with a number of different headphones...Sennheiser HD600, HD6xx, EE-MU Teak's, etc. streaming through Tidal on Master quality.

In any case, I just ordered a bunch of tubes to roll into it (GE JAN5654W,  Mullard M8100 / CV4010, Tung-Sol 6AK5) and honestly didn't even remember what I ordered the first time (and couldn't read the labels) but I must have used this thread to order the first time, because apparently I ordered the exact same Voshkod/Novosibirsk Tubes from the exact same company (Yen Audio) without even meaning to. 

First off, thanks for the advice that led me down this road!  I just received the first pair and I think they already sound great and better than the older versions, which must have deteriorated over time.

That said, I have read a bunch about burning in the tubes, but literally as soon as I put the same combo in they sounded livelier and drove louder than the existing tubes.  The question I have is whether or not there is in fact a burn in period for all tubes, and if so, what can I expect to hear differently?  In Addition, I haven't seen much mentioned about power tubes.  Do they impact the quality also, and if so is there a chart similar to that on the first page of this thread that someone can point me to that has reviews?  if not, recommendations?

Thanks in advance!


----------



## Moak

I own a Grado GH2, an Oppo PM3 and a Hifiman HE400i.  
Which of the Little Dot (MK1+, MK2 or MK3) would fit best with the headphones?  
Which tubes work best with it?


----------



## sghound

Monolaf said:


> I own a Grado GH2, an Oppo PM3 and a Hifiman HE400i.
> Which of the Little Dot (MK1+, MK2 or MK3) would fit best with the headphones?
> Which tubes work best with it?



mk 1


----------



## daniboun

Monolaf said:


> I own a Grado GH2, an Oppo PM3 and a Hifiman HE400i.
> Which of the Little Dot (MK1+, MK2 or MK3) would fit best with the headphones?
> Which tubes work best with it?



For me 6BE6W tubes are the best ! see my review )


----------



## Whelkie D

daniboun said:


> For me 6BE6W tubes are the best ! see my review )


What setting would you have the jumper pins to use the 6BE6W on a Little Dt MK11? Ef95 or EF91/92?


----------



## cirodts

can I replace 6k4 valves with ge 5654?


----------



## daniboun

Whelkie D said:


> What setting would you have the jumper pins to use the 6BE6W on a Little Dt MK11? Ef95 or EF91/92?



Recommended strapping: NS > 2/7 > 1/7, take a look here on page 153 for Heptodes.
I use it now on my P1 tubes Preamplifier.... I will share my Sylvania 6BE6W review asap.


----------



## Acapella11 (Nov 9, 2019)

NYGator said:


> Long story, short punchline/questions from an amateur audiophile.  I purchased a little Dot MKii about 5 years ago and initially changed out the stock tubes and replaced them with 2x Voshkod 6ZH1P-EV and 2x Novosibirsk 6H6P-I.  I never wound up using the amp all that much because I had ground loop issues and I must not have explored solutions at the time or realized they existed.  I recently became interested again and solved the loop issue with a device I found on Amazon that worked real well.  (If someone thinks there is a better solution I would appreciate it, but this removed the static and did not appear to interfere with the sound quality.)
> 
> https://www.amazon.com/gp/product/B01L1NP7YI/ref=ppx_yo_dt_b_asin_title_o05_s00?ie=UTF8&psc=1
> 
> ...




Hi NY, see my sig for a link to a page with the low down of our findings at the time.
This covers tubes including adapters but not plus additional external power supplies
Power tubes also make a difference, even though a little less than driver tubes, but significant enough. The best combination without socket adapters were the 6N6P-IR, ideally up to 1984 or so, when the Cold War QC was still in place. Best value driver were the 6HA5 long bottle. With socket adapters, you can use 6SN7 as power tubes, but bear in mind that they don’t power lower impedance headphones like the HE-400i or 500 well. Best drivers with adapters were the C3G/S.
This is all a matter of taste of course but quite a few people agreed.
Possibly, a power regenerator could solve the power loop as it generates a new power sine wave signal from a battery. Also, the amps sound better with cleaner power. An quite affordable model comes from PowerInspired, the AG500.
Good luck on your journey!


----------



## Datun Walnut

Anybody thought of using CV181 power tubes ? 
I'm running 1950s Sylvania 6SNGTs with adapters at the moment (my all time favourite tube for the LD mk2) along with Mullard CV4014s
The CV181 should be a direct replacement for the 6SN7GTs


----------



## gibosi (Nov 9, 2019)

Datun Walnut said:


> Anybody thought of using CV181 power tubes ?
> I'm running 1950s Sylvania 6SNGTs with adapters at the moment (my all time favourite tube for the LD mk2) along with Mullard CV4014s
> The CV181 should be a direct replacement for the 6SN7GTs



If you are talking about the original Mullard CV181 / ECC32, it might be OK. My only reservation would be heater current. The 6N6P draws at most 0.8 amps while the CV181 draws 0.95 amps. The difference is small enough that it might be OK, but since I do not know the maximum rating for the LD transformer I have to assume that there is some risk of transformer failure.

On the other hand, if you are talking about the Chinese Shuguang CV181, it is electrically identical to the 6SN7, drawing 0.6 amps, and is as safe as any other 6SN7.


----------



## djpeder

Two old Sylvania 6BU6 for my Little Dot Mk II.


----------



## TrollDragon

djpeder said:


> Two old Sylvania 6BU6 for my Little Dot Mk II.


Double-Diode Triodes won't work.


----------



## djpeder

Works fine if you cut pin 5 and 6.


----------



## mxxl

I just ordered a mkiii, I remember with the mkii it was recommended to upgrade the opamps, should I do the same with the mkiii?


----------



## Datun Walnut

AFAIK, there are no opamps in the MKII.


----------



## MIKELAP

mxxl said:


> I just ordered a mkiii, I remember with the mkii it was recommended to upgrade the opamps, should I do the same with the mkiii?


There is no opamps to change  in LDMK3 .The only thing you will have to possibly swithch around  are the gain switches and the jumpers depending on what type of tubes you are using for example EF92, EF95 ectcs . What i would recommend is to get those 2.54mm 
 extended jumpers they are alot easier to reposition than the stock ones when rolling different type tubes


----------



## Whelkie D

Just to double-check. Can I use 6BE6 tubes in the LD MK2 without any strapping? Would the jumpers have to be in the EF95 position? Thanks.


----------



## MIKELAP (Dec 31, 2019)

Whelkie D said:


> Just to double-check. Can I use 6BE6 tubes in the LD MK2 without any strapping? Would the jumpers have to be in the EF95 position? Thanks.


      From what i saw you can use ef92 and ef95 settings ef92 having a more detailed sound page 77


----------



## SHIMACM

Hello people. Although I read a lot, I have little participation in the forum. I've been following your guidance when rolling tubes on my Little Dot MK IV. I am currently using the C3G tubes as a driver and the Sylvania 6SN7 tubes (black skirt) as power tubes. Regarding the Siemens C3G tubes I know they are the driver end tubes. But for power tubes, what would be the next update. I want to make it clear that my limit goes to the use of adapters. I do not want to use external power source. Therefore, the 6080 / 6AS7 pipes are already immediately excluded. Thanks!


----------



## MIKELAP

SHIMACM said:


> Hello people. Although I read a lot, I have little participation in the forum. I've been following your guidance when rolling tubes on my Little Dot MK IV. I am currently using the C3G tubes as a driver and the Sylvania 6SN7 tubes (black skirt) as power tubes. Regarding the Siemens C3G tubes I know they are the driver end tubes. But for power tubes, what would be the next update. I want to make it clear that my limit goes to the use of adapters. I do not want to use external power source. Therefore, the 6080 / 6AS7 pipes are already immediately excluded. Thanks!


Personnally the C3G and 6SN7 combo is as far as i went with adapters


----------



## gibosi

While maybe more of a lateral move than an update, the 5687 might be worth a try. It needs a simple pin-adapter, but no external power supply is needed.


----------



## Acapella11 (Jan 3, 2020)

SHIMACM said:


> Hello people. Although I read a lot, I have little participation in the forum. I've been following your guidance when rolling tubes on my Little Dot MK IV. I am currently using the C3G tubes as a driver and the Sylvania 6SN7 tubes (black skirt) as power tubes. Regarding the Siemens C3G tubes I know they are the driver end tubes. But for power tubes, what would be the next update. I want to make it clear that my limit goes to the use of adapters. I do not want to use external power source. Therefore, the 6080 / 6AS7 pipes are already immediately excluded. Thanks!


Hi Shimacm, I tried three different 6SN7 tubes, and I don’t remember which ones exactly. At the same time, I had an (expensive) 6N30P-DR (1982), which I found superior. Besides this, it also drove my Hifiman HE-500, that I had at the time. I think the pair of DRs was £250. This was the best MKIII/IV power tube I have heard, of which all were with the regular power supply only.


----------



## mxxl

Currently have a mkiii with voshkod 6zh1p-ev tubes, they sound amazing with my dt880s. I plan to purchase a pair of t1s or similar phones, and I have a pair of m8100 and m8161 and 6n13s power tubes on the way. Can yall suggest any more tubes to try for cans like these?


----------



## willne1 (Jan 14, 2020)

I love my 6HM5 tubes from Yugoslavia better than anything else I've tried which isn't a whole lot I'll admit. They're not expensive either. I should mention I am using Massdrop Sennheiser HD 6XX


----------



## Whelkie D

willne1 said:


> I love my 6HM5 tubes from Yugoslavia better than anything else I've tried which isn't a whole lot I'll admit. They're not expensive either. I should mention I am using Massdrop Sennheiser HD 6XX


Yes, I'll second the Yugo 6HM5. Just make sure you get the taller ones as I've heard people say that the "short" ones can be a bit sibilant.


----------



## mxxl

Acapella11 said:


> Hi Shimacm, I tried three different 6SN7 tubes, and I don’t remember which ones exactly. At the same time, I had an (expensive) 6N30P-DR (1982), which I found superior. Besides this, it also drove my Hifiman HE-500, that I had at the time. I think the pair of DRs was £250. This was the best MKIII/IV power tube I have heard, of which all were with the regular power supply only.


Would you mind pointing me in the direction of a good 6ns7 adapter? I found one that had the right pin layout on tube depot, but it is listed as a 6922 and I’m not sure if the power tubes are different than the drivers at all


----------



## Datun Walnut

mxxl said:


> Would you mind pointing me in the direction of a good 6ns7 adapter? I found one that had the right pin layout on tube depot, but it is listed as a 6922 and I’m not sure if the power tubes are different than the drivers at all


These were the ones I ordered:


----------



## mxxl

So I just got a pair of m8161s and m8100s in. The m8100s sound great, but the m8161s are both much lower volume and one of them is noticeably lower than the other. Could this be from oxidation or did I likely get bad tubes?


----------



## gibosi

Have you mechanically cleaned to pins? For example, I would scrape them with a knife and then roll them in again.


----------



## mxxl

gibosi said:


> Have you mechanically cleaned to pins? For example, I would scrape them with a knife and then roll them in again.


Just tried that, they’re shiny now and still same issue. About 4db of channel imbalance and still too quiet at max volume


----------



## gibosi

If you swap them right to left and left to right and the problem follows the tubes, then I would say that you have some bad tubes. Good luck!


----------



## mordy

mxxl said:


> So I just got a pair of m8161s and m8100s in. The m8100s sound great, but the m8161s are both much lower volume and one of them is noticeably lower than the other. Could this be from oxidation or did I likely get bad tubes?


Please check out if the M8161 is of the same tube family as the M8100.
From memory the 8161 is from the EF92 family and may require a different jumper setting than the 8100 that I think is from the EF95 family of tubes.
If I am correct this could account for your problem with the 8161 tubes.


----------



## mxxl

mordy said:


> Please check out if the M8161 is of the same tube family as the M8100.
> From memory the 8161 is from the EF92 family and may require a different jumper setting than the 8100 that I think is from the EF95 family of tubes.
> If I am correct this could account for your problem with the 8161 tubes.


Omg I can’t believe I forgot about this, that’s most likely the problem. I’ll go try it with the proper jumper setting


----------



## Sigs1978

Hi Guys,  I have a LD 1+ incoming that has NE 408A's installed as well as an upgraded opamp.  My only headphones are AKG k7xx's.  I've been looking through this thread and learning a lot, but I'm hoping someone can help me cheat - I'd like to get a "jump" on the correct jumper settings for both the 408a's and my headphones.  Can anyone recommend the correct settings?


----------



## mordy

mxxl said:


> Omg I can’t believe I forgot about this, that’s most likely the problem. I’ll go try it with the proper jumper setting


All is good?


----------



## mxxl

mordy said:


> All is good?


Yup, finally got tweezers to switch the jumpers, and the m8161s may be better than my m8100s
Still have to burn them in more and compare


----------



## mordy (Jan 26, 2020)

mxxl said:


> Yup, finally got tweezers to switch the jumpers, and the m8161s may be better than my m8100s
> Still have to burn them in more and compare


You could get jumpers with litle extension handles on them very cheap - makes it easier to handle (pun intended) lol...





I think that I remember sticking on a toothpick and piece of lollipop stick on them to make it even easier to change - just cut them off so that they don't hit the surface the amp is standing on.


----------



## mxxl

mordy said:


> You could get jumpers with litle extension handles on them very cheap - makes it easier to handle (pun intended) lol...
> 
> 
> 
> ...


Yeah, I just ordered some of the longer jumpers, should do the trick. I’m just gonna burn these in for now and then a/b when those come in


----------



## mxxl

Has anyone had both the yugoslavian 6hm5 and the m8161? If so, how do they compare to each other?


----------



## mordy

mxxl said:


> Has anyone had both the yugoslavian 6hm5 and the m8161? If so, how do they compare to each other?


I had both but much preferred the sound of Ei 6HM5. The 8161 also made my LD MKIII run really hot.


----------



## Whelkie D

mxxl said:


> Has anyone had both the yugoslavian 6hm5 and the m8161? If so, how do they compare to each other?


Both sound equally good but for different reasons.  The M8161 have the edge on "warmth" but the 6HM5s are a little more detailed, particularly in the mid to high section. Just my opinion, obviously, but I like both these tubes and would be hard pushed to choose between them. Sorry if this isn't very helpful.


----------



## mxxl (Feb 9, 2020)

Whelkie D said:


> Both sound equally good but for different reasons.  The M8161 have the edge on "warmth" but the 6HM5s are a little more detailed, particularly in the mid to high section. Just my opinion, obviously, but I like both these tubes and would be hard pushed to choose between them. Sorry if this isn't very helpful.


That’s actually really helpful. I picked up some sylvania 6sn7gta which made the treble smoother and are generally more detailed, so I’m looking for something that will up the detail retrieval and take away the remaining veil.
I picked up a magni 3+ recently to see what all of the hype was about and my mkiii with my current setup sounds much better


----------



## kousik1946

I have 3 pairs- Mullard, Yugoslovia and Voshkod. Mullard is the most warm and Voshkod is the least warm. Because the tube sound is always warm, I like the Voshkod most. Yugoslovia is also very good. I use it with my mkiii and HD600.


----------



## mxxl (Mar 3, 2020)

I’ve recently upgraded to the t1 gen 2. They’re quite warm, so I’ve rediscovered my love for the voshkods. I have a pair of 6hm5 coming in as well, looking forward to seeing how they perform. The ge jan 5654w are also a winner as far as mids go, I think it’s awesome that tube rolling can add so much versatility to your setup.


----------



## lupoal (Mar 29, 2020)

Hi,
I have one Little Dot MKII (last hardware release) and I've read roughly half of this huge thread... I've already bought many different NOS 5654 versions (Mullard, GE, a couple of amazing and expensive Siemens, etc. etc.) and then I've seen people talking about EK90, so I bought couple of them NOS NIB 12/69 Telefunken because of curiosity (only 10 euros on e-bay... amazing)... now, before to plug-in and turn ON... are those still ok? I mean... compatible/safe in EF95 mode as listed at page 77 in this thread? (I don't want to damage my Little Dot, I love it)
.
then, always about valves, now I'm running a couple of 6N6P Foton gold grid... but I've read good things about 6N6P-IR (not just "I"), these costs roughly double then the Foton... does it make sense to buy a couple of them? Or, as spare part, another couple of Foton are more then enough that there are not so big differences between those two variants?

thank you in advance for help


----------



## vixro (Mar 28, 2020)

Just got around to rolling some tubes I bought years ago (my little dot had a broken cap that I just spent the last 2 days taking apart and repairing, that space is TIGHT!!!!!!!).  Now that I've had a chance to really test my RCA 6AK5W's and these Voskhod's I'm happy to say the Voskhod's are more open and better bass.  The RCA's feel just a bit tight for me when listening to electronic dance music but I'm going to give them another shot next time I have some classical music playing.

I have an extra pair of 6J1P-EV's, number 13, VII - 77, platinum plated unused old stock if anyone wants.  I bought 4 about 5 years ago from two different sellers but they appear to sound identical to each other.  Anyone want to trade my pair with some tubes they might recommend for EDM?  Shoot me a PM.

Next up I need to try the gold Voskhod's!


----------



## HungryPanda

My favourite tubes are the Voskhod's followed by the Mullards


----------



## mxxl

If anyone needs tubes, I have a bunch of ef95/91 I’m looking to get rid of. They’re all used for less than 200 hours, some are barely used at all. Pm me if interested


----------



## RikudouGoku

I got my 1+ today and I got 4 stock tubes. Are they all the same and they just give 1 pair as a replacement? They all have the 6j1 and some other number to the upper left. 
1.73
2.79 or it could be 19...(barely visible but most likely 79)
3.81
4.80


----------



## dhm78

I can't seem to find any information on my model. It's a Little Dot 2 vs MK 2. Does anyone have any recommendations?


----------



## TrollDragon

dhm78 said:


> I can't seem to find any information on my model. It's a Little Dot 2 vs MK 2. Does anyone have any recommendations?


That is a really old version and you will have a hard time finding tubes for it with basically no options for rolling.


----------



## BattousaiX26

Anyone knows where can I still find sylvania gb 5654 on US?


----------



## jubjubb

Hey guys.
I'm enjoying a lot reading this tread!
I've decided to try the 6SN7 route to complement my GE JAN 5654Ws with my beloved MKIII.

I've ordered a set of these adapters: https://www.ebay.ca/itm/1PC-6SN7-TO...118686?hash=item3618c9e59e:g:dEwAAOSwXetZXP2f
to use with these Sylvania made Canadian tubes, that I tought would sound great: https://www.ebay.ca/itm/Pair-of-6SN...e=STRK:MEBIDX:IT&_trksid=p2057872.m2749.l2649

The thing is, these power tubes don't seems to light up. No light inside the vacuum when I power on... NO SOUND!
Does anybody have an idea if i'm missing something, or maybe BOTH of my NOS tubes are bad 
Thanks.


----------



## jubjubb

jubjubb said:


> Hey guys.
> I'm enjoying a lot reading this tread!
> I've decided to try the 6SN7 route to complement my GE JAN 5654Ws with my beloved MKIII.
> 
> ...


I left the amp powered on for 15 minutes to see if it would help. To my suprise, the amp got so hot that I just unplugged it right away!
Oh my god! It smells like plastic burned 😦
I really think I messed up now.
I’m just letting it cool down for an hour before trying to turn it on again with stock tubes. Gosh 😣


----------



## TrollDragon

jubjubb said:


> I left the amp powered on for 15 minutes to see if it would help. To my suprise, the amp got so hot that I just unplugged it right away!
> Oh my god! It smells like plastic burned 😦
> I really think I messed up now.
> I’m just letting it cool down for an hour before trying to turn it on again with stock tubes. Gosh 😣


The 12AU7 is the wrong adapter. Pin 9 on the socket of the LD amp is tied to ground and pin 9 on the 12AU7 adapter connects to the center tap on the heater filaments, which is why the tubes never lit up as they were looking for 12V on the filaments.

The proper adapter is a 6SN7 to 6CG7.
https://www.ebay.ca/itm/1PC-6SN7-TO...-Socket-Adapter-Socket-Converter/233168869898


----------



## jubjubb

TrollDragon said:


> The 12AU7 is the wrong adapter. Pin 9 on the socket of the LD amp is tied to ground and pin 9 on the 12AU7 adapter connects to the center tap on the heater filaments, which is why the tubes never lit up as they were looking for 12V on the filaments.
> 
> The proper adapter is a 6SN7 to 6CG7.
> https://www.ebay.ca/itm/1PC-6SN7-TO...-Socket-Adapter-Socket-Converter/233168869898


This is really confusing hehe. So many adapters. Thanks for your link TrollDragon, I just bought these and I will try to send back the other adapters to the seller.
By the way, the amp is back to life! The thin plastic layer around the toroidal transformer melted a little bit. I see how it can be dangerous when unexperiented user mods occurs. So glad the Little Dot still works! Have to say, this is a tank!


----------



## macaltec

Tons of information here. I have read a lot but havent come across any deep discussion about 6sn7 tubes yet. Will any 6sn7 work provided I have the proper adapters? I have several 6SN7GTB tubes is why I ask. Thanks.


----------



## shepperd (May 9, 2020)

Just an added experience. There was a very good seller from the Ukraine. His site is down sadly but he had a lot of interesting and unusual tubes. If he reappears I will post the link. Anyway he once had an early version of the justifiably well known Voskhod. Unlike those it is not ribbed (which was probably done to make the tube more stable and resistant to vibration; remember it was used in fighter planes and maybe rockets) If I remember it dates from 74' and I think the ribbed version appears in 79'...that's just a guess because I have ones from 82. This older tube is ever so slightly warmer in tone and didn't take as long to break in. Non microphonic. I've been using it for a while now and haven't had the itch to try others from my tube stash. Out of curiosity, has anyone tried the rather infamous Telefunken, the one made in Germany with the diamond on the bottom? I say infamous because the prices are absurd for these now. By the way, sonically there is absolutely no difference between the so-called gold version of the Voskhod and the normal. I have had both.


----------



## muths66

Anyone know is 6j1 and 6j1pany different?
i have a preamp using a pair of 6j1 looking at vosh tube now.


----------



## naillos

I've currently been running a pair of Voskhod 6ZH1P-EV's for the past year which I swapped in immediately when I purchased my mk3. Have loved the sound but after reading more recent posts here I also ordered a pair of the Yugoslovia 6H5M which I am waiting for in the mail now to see if I'd enjoy them even more so. 
Looking to move from the stock power tubes as well and I am torn between going for the simpler and cheaper option of ordering a pair of 6N6P-ir or going with adaptors to some 6SN7's which would be about ~$40 more of investment.

Both seem to have great reviews from everyones comments here and I am finding it hard to decide between the two. Any words of advice? Is the difference between these 2 tubes worth the extra money spent on the adaptors?

thanks!


----------



## Dickymint

TrollDragon said:


> That is a really old version and you will have a hard time finding tubes for it with basically no options for rolling.


You can still get tubes for them, I have one of them and I got a full set.


----------



## TrollDragon

Dickymint said:


> You can still get tubes for them, I have one of them and I got a full set.


That's good to know, but there are still no options when it comes to rolling.


----------



## Dickymint

Not that I know of.


----------



## wavid (Jun 23, 2020)

Can someone please help me buy some genuine Mullard m8100 tubes in the UK?
It is my first time buying tubes and I dont want to mess up
There are so many on ebay and a lot of them look different. Are any of the stores more trusted and known here?
Also how important is getting a matched pair?


----------



## MIKELAP (Jun 23, 2020)

wavid said:


> Can someone please help me buy some genuine Mullard m8100 tubes in the UK?
> It is my first time buying tubes and I dont want to mess up
> There are so many on ebay and a lot of them look different. Are any of the stores more trusted and known here?
> Also how important is getting a matched pair?


Dont have to be matched  tubes 
Bought several time from them  https://www.langrex.co.uk/products/m8100-cv4010-5654-mullard-vintage-pair-valve-tube-ring-getter/


----------



## wavid (Jun 23, 2020)

MIKELAP said:


> Dont have to be matched  tubes
> Bought several time from them  https://www.langrex.co.uk/products/m8100-cv4010-5654-mullard-vintage-pair-valve-tube-ring-getter/


nice one thanks!
I was worried about getting a rebranded one or something. I read about some being made in Sydney or something and them being inferior.
EDIT: wow they have been around for 50 years apparently, 
this is exactly the type of people i like to order from, rather than some random seller on ebay.


----------



## chinerino

what power tubes should i get for my LD Mk II? currently i have Mullard m8100,  Voskhod 6ZH1P-EV  and GE JAN 5654W


----------



## MIKELAP

chinerino said:


> what power tubes should i get for my LD Mk II? currently i have Mullard m8100,  Voskhod 6ZH1P-EV  and GE JAN 5654W


Checkout page 201 post 3007


----------



## aclef

Hello guys, I just registered to comment this:
Little Dot LD1+ seems to be very forgiving for tube rolling, and I've tried several cheap Chinese tubes in default setting:

Tubes that works out of the box:
6J1(of course, it's the default tube , sharp cut-off pentode)
6K4(6BA6 equivalent, remote cut-off pentode, I feel the sound is warmer, some crispness is lost but it's still quite enjoyable. I've tried 6K4 from multiple brands, the sonic characteristic is very similar)

Tubes that will work if put a staple on to connect 2-7 pin:
6J4(sharp cut-off pentode, sound similar to 6J1, bass seems to be a little bit more pronounced)
6J5(sharp cut-off beam tetrode, brighter, it's sound characteristic is some what not tubey)
6K5(remote cut-off pentode, almost identical to 6K4)

Tubes I think might work but haven't tried:
6A2
other tubes in 6J family: 6J2 6J3
other tubes in 6K family: 6K7


----------



## Whelkie D

Hi, I'm finally thinking of getting some C3Gs for my LD MK2. Have seen some adaptors for them but was wondering what setting to put the jumper pins on to use them ( EF91/92 or EF95). Sorry if this has already been talked about, but I did a search for it and cannot find any info. Thanks


----------



## gibosi

Whelkie D said:


> Hi, I'm finally thinking of getting some C3Gs for my LD MK2. Have seen some adaptors for them but was wondering what setting to put the jumper pins on to use them ( EF91/92 or EF95). Sorry if this has already been talked about, but I did a search for it and cannot find any info. Thanks



All the adapters I have seen are C3g to 6AK5. And therefore, you would use the EF95 setting.


----------



## jahk20

Hi all,
I’ve just bought a lovely little dot mk iv.
I am super happy with the sound, it is well over what I was expecting. 
I am currently on probably stock tubes, but I do have some around and I will be swapping them around,
Would I be able to use these ones as power tubes with the required adaptors?


----------



## Whelkie D

gibosi said:


> All the adapters I have seen are C3g to 6AK5. And therefore, you would use the EF95 setting.


Thanks gibosi. I should have thought of that. Make sense now that you've pointed it out. Yet another of my "senior moments". Oh dear.


----------



## Ultrainferno

No mentions here at all on Head-Fi about the LD H1, using two 6SN7. I'm thinking of getting one, but to run with the PSVANE CV181-TII.
Has anyone heard this amp anywhere?


----------



## EnubisTheGalka

Hello everyone. I have a Fosi T20 that uses the same tube size.  I read a bit through the thread and was checking for some suggestions for a tube that would provide clean bright sound for competitive FPS gaming.  I would rather it be light on the bass and the main aim would be to have the most precise imaging. 

Thanks!


----------



## MIKELAP

EnubisTheGalka said:


> Hello everyone. I have a Fosi T20 that uses the same tube size.  I read a bit through the thread and was checking for some suggestions for a tube that would provide clean bright sound for competitive FPS gaming.  I would rather it be light on the bass and the main aim would be to have the most precise imaging.
> 
> Thanks!


If memory serves me  these were clean sounding i have the tubes but dont have the amp anymore: ELECTRO HARMONIX 6H30Pi and VOSKHOD 6ZHiP-EV .


----------



## EnubisTheGalka

MIKELAP said:


> If memory serves me  these were clean sounding i have the tubes but dont have the amp anymore: ELECTRO HARMONIX 6H30Pi and VOSKHOD 6ZHiP-EV .


Thanks!


----------



## TrollDragon

jahk20 said:


> Hi all,
> I’ve just bought a lovely little dot mk iv.
> I am super happy with the sound, it is well over what I was expecting.
> I am currently on probably stock tubes, but I do have some around and I will be swapping them around,
> Would I be able to use these ones as power tubes with the required adaptors?


I think you will have a hard time finding an adapter for that tube as it's a voltage regulator and not a dual triode.


----------



## Flex2d

Hello, just picked up some mullard 8083 tubes, however i just discovered my little dot mk2 does not have ef91 settings. I can only see EF92 and EF 95. Is it ok to run these tubes on the EF92 setting? - Am i running a fire risk here?


Thanks

Daniel


----------



## Whelkie D

Flex2d said:


> Hello, just picked up some mullard 8083 tubes, however i just discovered my little dot mk2 does not have ef91 settings. I can only see EF92 and EF 95. Is it ok to run these tubes on the EF92 setting? - Am i running a fire risk here?
> 
> 
> Thanks
> ...


I always run EF91 on the EF92 setting with no problems.


----------



## Flex2d

Whelkie D said:


> I always run EF91 on the EF92 setting with no problems.


Ok cool, just concerned by the extra voltage needed would cause issues . Have to say the Mullard 8038 are sounding rather nice!


----------



## Whelkie D

Flex2d said:


> Ok cool, just concerned by the extra voltage needed would cause issues . Have to say the Mullard 8038 are sounding rather nice!


I'd also recommend the Osram Z77s.
https://www.ebay.co.uk/itm/New-Old-...e=STRK:MEBIDX:IT&_trksid=p2060353.m1438.l9372


----------



## Flex2d

Whelkie D said:


> I'd also recommend the Osram Z77s.
> https://www.ebay.co.uk/itm/New-Old-Stock-Osram-Z77-6AM6-6F12-8D3-CV138-CV4014-EF91-HP6/333580063339?ssPageName=STRK:MEBIDX:IT&_trksid=p2060353.m1438.l9372


cheers, just picked up a pair


----------



## aclef

gibosi said:


> Quote:
> 
> 
> Yes indeed, I tested several pairs of 6BA6 in my LD1+, including a pair manufactured in 1947, and they sounds fine... maybe not great, but at least average.
> ...



Hi, I bought LD1+ few weeks ago and I'm experimenting different tubes on it, and LD1+ indeed is very forgiving for tubes!
When I'm surfing this thread for information I found your informative reply on using 6BA6(a remote cut-off pentode) on LD1+, I tried it myself and found the result to be pleasing.

I'm not very familiar with tube amp design, you said the first stage of LD1+ is configured as cathode follower/buffer which provides no voltage gain, and replace the tube with a straight wire will work fine(which I haven't tried yet). Does that mean tube on LD1+ won't make any difference? Is it essentially a solid state amp?

Also I tried plug in a 6A2(6BE6 equivalent, Pentagrid-converter/Heptode), and it also worked. I do feel there seems to be some volume/sound change when I'm changing different tubes, but that maybe just my brain.


----------



## gibosi

aclef said:


> Does that mean tube on LD1+ won't make any difference? Is it essentially a solid state amp?



Yes, the LD1+ is essentially a solid state amp. The tubes are used only to add "flavor" to the sound.  But yes, sometimes swapping out tubes does seems to change the volume. For example, a tube with a strong mid range emphasis might sound louder than another tube with a more subdued mid range emphasis. But again, tubes provide no gain in the LD1+, and the volume is the same for every tube.


----------



## aclef

gibosi said:


> Yes, the LD1+ is essentially a solid state amp. The tubes are used only to add "flavor" to the sound.  But yes, sometimes swapping out tubes does seems to change the volume. For example, a tube with a strong mid range emphasis might sound louder than another tube with a more subdued mid range emphasis. But again, tubes provide no gain in the LD1+, and the volume is the same for every tube.



Thanks for your reply! I understand that the tube doesn't do any amplification, but it still changed the sonic characteristic right? I'm okay with it not amplifying, but I'd like it at least to be doing something


----------



## gibosi

aclef said:


> Thanks for your reply! I understand that the tube doesn't do any amplification, but it still changed the sonic characteristic right? I'm okay with it not amplifying, but I'd like it at least to be doing something



Yes indeed, each tube adds its unique sonic signature to the sound. And there are many different tubes to try. Have fun!


----------



## Flex2d

Hello, does anyone know the official little dot website url? can't find it on google..

thanks


----------



## Flex2d

Just another question  does anyone know if the little dot mk2 tubes will work with the little dot mk8?
thanks


----------



## TrollDragon

Flex2d said:


> Hello, does anyone know the official little dot website url? can't find it on google..
> 
> thanks


It's long gone, has been for years.


----------



## TrollDragon

Flex2d said:


> Just another question  does anyone know if the little dot mk2 tubes will work with the little dot mk8?
> thanks


No they won't work, the LD MK8SE uses 2x12AT7 as drivers and 4x6H30PI as output. The drivers are socket B9A dual triodes and the drivers for the MK2 are socket B7G pentodes.


----------



## Flex2d

TrollDragon said:


> No they won't work, the LD MK8SE uses 2x12AT7 as drivers and 4x6H30PI as output. The drivers are socket B9A dual triodes and the drivers for the MK2 are socket B7G pentodes.


Thanks for letting me know, between the mk6 and mk8 whats is the primary difference? is it just the tube types?
thanks


----------



## Flex2d

I would like to step up in the Little dot family, and would like balanced out put. currently running a little dot Mk2 and think it is fantastic with hd6xx. but i hear that the hd6xx do well on balanced. I really enjoy the tube rolling aspect and dont think the new mk3 will be a big enough step up. I am assuming the only difference between the mk6 and mk8 is the type of tubes. From a tube rolling aspect which would be recommended for the hd6xx cans?
Thanks


----------



## TrollDragon

Flex2d said:


> Thanks for letting me know, between the mk6 and mk8 whats is the primary difference? is it just the tube types?
> thanks


The Little Dot MK VIII SE has a single ended output as well as balanced, also it is basically two mono blocks in one case, each with their own power supply. (It uses two power cords.)


----------



## TrollDragon

Flex2d said:


> I would like to step up in the Little dot family, and would like balanced out put. currently running a little dot Mk2 and think it is fantastic with hd6xx. but i hear that the hd6xx do well on balanced. I really enjoy the tube rolling aspect and dont think the new mk3 will be a big enough step up. I am assuming the only difference between the mk6 and mk8 is the type of tubes. From a tube rolling aspect which would be recommended for the hd6xx cans?
> Thanks


Balanced headphone output is a bit of a misnomer in the headphone game and is a term adopted by the manufacturers for marketing purposes.

If you volume match a balanced headphone output with the singles ended output on the same amp you should hear zero difference between the two.  Mind you some manufacturers have designed their amps with poor single ended outputs just to show how much of an improvement balanced is, but those are underhanded shenanigans by crooked manufacturers.

You will see benefit from balanced output if the single ended side of the amp can't provide enough power to drive your headphones properly.  If the MK II drives the HD6xx properly now you will not see any benefit from driving them balanced. The common misconception is that balanced output is some sort of magic pill that will make headphones sound better.

You might find the LD MK VI better sounding than the MK II, but that would be due to the Octal tubes in it and not the balanced output.

I listened to the HD6xx at my daughters place on a Monolith AAA THX DAC/Amp and was underwhelmed, especially for all the hype they get. I will have to borrow them one day to try on my LD MK IV and see it they are any better.


----------



## Flex2d

Wow interesting, didn’t know that was the case with balanced headphone amps!
How do you find the little dot mk4?
If you were underwhelmed by the hd6xx, what headphone would you recommend?

cheers


----------



## Flex2d (Jul 26, 2020)

Could anyone recommend a good power tube, i have stuck with the 6n6p novosibirsk gold grid since i got the amp.

Thanks


----------



## aclef

Hmmm I noticed one of the 6K4(6BA6) I'm using on LD1+ is causing white noise in one channel, and the volume is slightly smaller. 

The getter inside the tube is getting thinner, almost transparent by now. I guess it's leaking very slowly. Turns out the condition of the tube do affect the sound! 

I'll see how long that tube lasts since the amp is almost on 24/7. It's the cheapest tube I have at hand and they're sold as defective tubes anyway.

What's the common lifespan of a B7G-based pentode/beam tetrode like 6BA6?


----------



## Yaska729

Flex2d said:


> Hello, does anyone know the official little dot website url? can't find it on google..
> 
> thanks


Their old website (a forum site) just came back online, which is www.littledot.net Also, they have a new website to shop, Mr. Yang has posted on the Chinese forum section, which is https://littledotus.com
I thought I may have replied this in the other thread?


----------



## TrollDragon

Yaska729 said:


> Their old website (a forum site) just came back online, which is www.littledot.net Also, they have a new website to shop, Mr. Yang has posted on the Chinese forum section, which is https://littledotus.com
> I thought I may have replied this in the other thread?


That's good to know, they have been gone a long time.


----------



## TrollDragon

Flex2d said:


> Wow interesting, didn’t know that was the case with balanced headphone amps!
> How do you find the little dot mk4?
> If you were underwhelmed by the hd6xx, what headphone would you recommend?
> 
> cheers


My go-to are the DT880 on the MK IV and modified T50RP MK2 on solid state. That Sennheiser veil was the first thing that jumped out at me when I tried the HD6xx and that was all I could hear. It might be different if I used them with tubes on a daily basis though. I also tried the HE4xx that day too and would take my T50RPs over them any day.  Different ears, different gears so they say, there are a lot of people who don't like the DT880s and even some who enjoy Grado.


----------



## TrollDragon

Flex2d said:


> How do you find the little dot mk4?


I love it!  Drivers are Yugoslavia EI 6HM5 (5 years running) and a pair of 6H30Pi-EV outputs.  I did change out the headphone jack to a proper locking version from Neutrik as that cheap clone one Little Dot used for the MK IV is pure junk.


----------



## Flex2d

TrollDragon said:


> My go-to are the DT880 on the MK IV and modified T50RP MK2 on solid state. That Sennheiser veil was the first thing that jumped out at me when I tried the HD6xx and that was all I could hear. It might be different if I used them with tubes on a daily basis though. I also tried the HE4xx that day too and would take my T50RPs over them any day.  Different ears, different gears so they say, there are a lot of people who don't like the DT880s and even some who enjoy Grado.


yeah I tried the 1770pro and just couldn't get on with them, so then got the foster 610's which I also didn't get on with. So I decided to try the 1990pro's which I read great things about,. to my dismay I dint like these either, so I figured I didn't like the byerdynamic sound. So I thought I would try the hd6xx as they are so highly spoken about. When pairs with the little dot they really are great (personally ) it just made sense, sweet low end great mids and instruments and female vocals just popped with all the detail and texture I was looking for.  I have started rolling the power tubes and realised they really effect the overall presentation and details of the music. The adventure continues!
I was eyeing up the t60rp the other day, they look very attractive for the money the t50rp also look really nice. maybe I should try planar with the little dot mk2 .


----------



## MIKELAP

Flex2d said:


> Hello, does anyone know the official little dot website url? can't find it on google..
> 
> thanks


If you want general infos about amps http://littledot.net/


----------



## TrollDragon

Flex2d said:


> yeah I tried the 1770pro and just couldn't get on with them, so then got the foster 610's which I also didn't get on with. So I decided to try the 1990pro's which I read great things about,. to my dismay I dint like these either, so I figured I didn't like the byerdynamic sound. So I thought I would try the hd6xx as they are so highly spoken about. When pairs with the little dot they really are great (personally ) it just made sense, sweet low end great mids and instruments and female vocals just popped with all the detail and texture I was looking for.  I have started rolling the power tubes and realised they really effect the overall presentation and details of the music. The adventure continues!
> I was eyeing up the t60rp the other day, they look very attractive for the money the t50rp also look really nice. maybe I should try planar with the little dot mk2 .


Low Z planars don't really pair well with OTL amps, you get bass roll off. The T50RPs really shine with an amp that can put out 1W or more.  If I do get another solid state amp it will be the Emotiva BasX A-100 to bring my Fostex to life. 

Also, stock T50RPs sound horrible out of the box, they have to be modded. Get yourself a pair of Argon's that already have the modding done.
https://www.modhouseaudio.com/


----------



## Yaska729

TrollDragon said:


> That's good to know, they have been gone a long time.


Yeah, it's been a long while. It seems like they have not done any marketing for a long while. I found out about the new site couple of weeks ago, and they've got quite a line of interesting products.


----------



## Flex2d

TrollDragon said:


> Low Z planars don't really pair well with OTL amps, you get bass roll off. The T50RPs really shine with an amp that can put out 1W or more.  If I do get another solid state amp it will be the Emotiva BasX A-100 to bring my Fostex to life.
> 
> Also, stock T50RPs sound horrible out of the box, they have to be modded. Get yourself a pair of Argon's that already have the modding done.
> https://www.modhouseaudio.com/


Thanks for the heads up! I picked up a pair of t60rp last night, should arrive today. Will see how they behave on LDMk2 plus as-701.


----------



## TrollDragon

Flex2d said:


> Thanks for the heads up! I picked up a pair of t60rp last night, should arrive today. Will see how they behave on LDMk2 plus as-701.


Nice! I do love the look of the T60RP and would like to get a chance to hear them one of these days, Fostex makes great heaphones.


----------



## Flex2d

TrollDragon said:


> Nice! I do love the look of the T60RP and would like to get a chance to hear them one of these days, Fostex makes great heaphones.


So, yeah i am impressed, definetly more high end and low end, really nice to listen to in fact and i have to say you are right! They sound a lot better on my as-701 vs LDmk2. And they really highlight the HD6xx deficiencies in the high and low end. I am really struggling to find an issue with the them. defo take more juice, and dont run so well on valve amp. very clean sounding, but still musical. very nice! think i will be keeping these 
(sorry for going off piste with the thread)


----------



## TrollDragon

Flex2d said:


> So, yeah i am impressed, definetly more high end and low end, really nice to listen to in fact and i have to say you are right! They sound a lot better on my as-701 vs LDmk2. And they really highlight the HD6xx deficiencies in the high and low end. I am really struggling to find an issue with the them. defo take more juice, and dont run so well on valve amp. very clean sounding, but still musical. very nice! think i will be keeping these
> (sorry for going off piste with the thread)


Awesome! I love my planars and wouldn't give them up for love nor money.

Now I am going to see if I can test out a pair of T60RPs  
I really hate this place...


----------



## Whelkie D

OK, so my C3Gs and adaptors arrived. Put them in my LD mk2 and got a mind-bendingly loud buzzing from the left channel. So took advice from some of the earlier posts on here and changed the gain settings from "3" (which I normally use) to "5". Buzzing disappeared and the tubes sound pretty good. However there is a definite background hum which I have not noticed before. Swapped the C3Gs out for some Mullard 8100s and the hum is still there (although not quite as loud). Is this just the gain change that has caused the hum  or is it something I should worry about. If this cannot be cured I may have to try going back to Gain "3" and see if it disappears. Sad, if that's the case, as I love the sound of the C3Gs but not sure if I can live with the hum, particularly on quiet tracks. Any advice much appreciated.


----------



## MIKELAP

Whelkie D said:


> OK, so my C3Gs and adaptors arrived. Put them in my LD mk2 and got a mind-bendingly loud buzzing from the left channel. So took advice from some of the earlier posts on here and changed the gain settings from "3" (which I normally use) to "5". Buzzing disappeared and the tubes sound pretty good. However there is a definite background hum which I have not noticed before. Swapped the C3Gs out for some Mullard 8100s and the hum is still there (although not quite as loud). Is this just the gain change that has caused the hum  or is it something I should worry about. If this cannot be cured I may have to try going back to Gain "3" and see if it disappears. Sad, if that's the case, as I love the sound of the C3Gs but not sure if I can live with the hum, particularly on quiet tracks. Any advice much appreciated.


If you change around the tubes does the hum follow to the other channel? i dont remember my homemade adapters ever having a hum


----------



## Whelkie D

MIKELAP said:


> If you change around the tubes does the hum follow to the other channel? i dont remember my homemade adapters ever having a hum


The hum is on both channels. The deafening buzzing was just the left channel.


----------



## MIKELAP

Whelkie D said:


> The hum is on both channels. The deafening buzzing was just the left channel.


Could problem be adapters ?


----------



## Whelkie D

MIKELAP said:


> Could problem be adapters ?


Possibly Mike, but there seems to be a slight hum now when using the Mullard 8100s. It's not earth-shattering, but I notice it in the gaps between notes on quieter pieces of music. Maybe it is just something that I am only just noticing now that I have the Gain up higher than normal. And I really like your adaptor tutorial by-the-way. One day I may attempt it when I'm feeling more confident!


----------



## TrollDragon

I only get hum on the LD MK IV with low impedance headphones such as my Ultrasone HFI-780.  I run at gain 5 as 3 sounded horrible to me with the DT880s. 

It's possible one of the connectors on your amps tube socket is dirty or expanded too much from the adapter. If the hum is happening with all tubes, then I would suspect that or possible a cold solder where the socket attaches to the board.


----------



## Datun Walnut

Flex2d said:


> Could anyone recommend a good power tube, i have stuck with the 6n6p novosibirsk gold grid since i got the amp.
> 
> Thanks


If you have the Mk-2, I can wholeheartedly recommend a pair of Brimar 6SN7GTs with adaptors. Ive been running NOS Sylvanias and loved them till I picked up the Brimars. Very warm with silky vass.


----------



## Datun Walnut

chinerino said:


> what power tubes should i get for my LD Mk II? currently i have Mullard m8100,  Voskhod 6ZH1P-EV  and GE JAN 5654W


Try some 6SN7GTs with adaptors. A matched pair of Russian 6H8Cs are nice as are Sylvania 6SN7s I'm running Brimar 6SN7s at the moment and they are truly gorgeous sounding.


----------



## Datun Walnut

macaltec said:


> Tons of information here. I have read a lot but havent come across any deep discussion about 6sn7 tubes yet. Will any 6sn7 work provided I have the proper adapters? I have several 6SN7GTB tubes is why I ask. Thanks.


That's what I use: 
Sylvania 6SN7GT. Nice all rounder lovely detailed highs 
Sovtek 6h8c - surprisingly good for the price. 
Brimar- gorgeous velvety bass.


----------



## Flex2d

Datun Walnut said:


> If you have the Mk-2, I can wholeheartedly recommend a pair of Brimar 6SN7GTs with adaptors. Ive been running NOS Sylvanias and loved them till I picked up the Brimars. Very warm with silky vass.


Don’t suppose you have a link to the adapter?
Cheers


----------



## Datun Walnut

Flex2d said:


> Don’t suppose you have a link to the adapter?
> Cheers


Hi, they are 6SN7 to 6CG7 adaptors from ebay. Just make sure it's 6sn7 top to 6cg7 bottom


----------



## Datun Walnut

Datun Walnut said:


> Hi, they are 6SN7 to 6CG7 adaptors from ebay. Just make sure it's 6sn7 top to 6cg7 bottom


https://www.ebay.com/itm/303542012598


----------



## Flex2d

Datun Walnut said:


> https://www.ebay.com/itm/303542012598


Thanks!


----------



## Flex2d

With the tubes Brimar 6SN7GT  , are these ok: https://brimaruk.com/valves/triodes/brimar-6sn7gt/
They seem alot cheaper then some at 200


----------



## Datun Walnut

Flex2d said:


> With the tubes Brimar 6SN7GT  , are these ok: https://brimaruk.com/valves/triodes/brimar-6sn7gt/
> They seem alot cheaper then some at 200


I don't know to be honest. These are new Brimars and I've never tried them. You could do a lot worse than a pair of old sylvanias. They are cheaper than Brimars.


----------



## tubebuyer2020

Flex2d said:


> With the tubes Brimar 6SN7GT  , are these ok: https://brimaruk.com/valves/triodes/brimar-6sn7gt/
> They seem alot cheaper then some at 200



That is re-branded Chinese Shuguang: https://www.google.com/search?q=shuguang+6sn7gt&tbm=isch


----------



## Flex2d

Just picked up second hand pair of sylvanias from 50’s. Should do the trick


----------



## Datun Walnut

Flex2d said:


> Just picked up second hand pair of sylvanias from 50’s. Should do the trick


They will. Nice one.


----------



## Datun Walnut

Just picked up a load of TV and Radio valves and found a pair of unopened CV138 from GEC in amongst the dross. They are a type of EF91. I'm very happy with my CV4014 but I've just tried tbe GECs and I really like them. May be a bit brighter. Certainly less laconic. I think they may be my 'Rock' choice.


----------



## Datun Walnut

My latest pair: NOS Brimar 6AM6. The jury's out at the moment. The top end sounds a bit brittle and the overall sound seems a bit uninteresting. Perhaps I'm being a bit harsh as they haven't broken in


----------



## TrollDragon

Datun Walnut said:


> My latest pair: NOS Brimar 6AM6. The jury's out at the moment. The top end sounds a bit brittle and the overall sound seems a bit uninteresting. Perhaps I'm being a bit harsh as they haven't broken in


I thought that picture looked familiar from the Tube group.


----------



## Datun Walnut

TrollDragon said:


> I thought that picture looked familiar from the Tube group.


I've been sussed. This is my alter ego


----------



## Flex2d

Whelkie D said:


> I'd also recommend the Osram Z77s.
> https://www.ebay.co.uk/itm/New-Old-Stock-Osram-Z77-6AM6-6F12-8D3-CV138-CV4014-EF91-HP6/333580063339?ssPageName=STRK:MEBIDX:IT&_trksid=p2060353.m1438.l9372


So i picked up a pair of these and been running my new t60rp head phones. and yeah these tubes are fantastic! thanks for the recommendation! very impressed with the sound of these!
best

Daniel


----------



## Datun Walnut

Flex2d said:


> So i picked up a pair of these and been running my new t60rp head phones. and yeah these tubes are fantastic! thanks for the recommendation! very impressed with the sound of these!
> best
> 
> Daniel


Must try a pair. Thanks


----------



## Flex2d (Aug 11, 2020)

So just received my converters for the 6sn7 sylvania, does anyone know what EF setting i should have the LT mk2 set to?
Edit: plugged em in and worked straight away! 

Thanks
Daniel


----------



## Flex2d

Ok whos got some good 6sn7 recommendations for my LDMk2?


Thanks
Daniel


----------



## Yaska729

Flex2d said:


> Ok whos got some good 6sn7 recommendations for my LDMk2?
> 
> 
> Thanks
> Daniel


I’ve tried a pair of Mullard CV181 on my LD H1, and man the sound is amazing. These tubes go for ridiculous price now though, I beg weeks until my friend let me tried them.


----------



## Flex2d

Yaska729 said:


> I’ve tried a pair of Mullard CV181 on my LD H1, and man the sound is amazing. These tubes go for ridiculous price now though, I beg weeks until my friend let me tried them.


Wow those are expensive 600-800


----------



## Datun Walnut

Flex2d said:


> Ok whos got some good 6sn7 recommendations for my LDMk2?
> 
> 
> Thanks
> Daniel


Sylvanias are nice and very neutral. Sovtek 6H8Cs are quite similar and really cheap.
As said elsewhere, Mullards are gorgeous but my all time favourites are Brimar 6SN7GT or CV1988 the bass is deep and chocolatey and paired with a pair of Mullard CV4014s, they are hard to beat.
Sometimes you can be lucky on eBay but look for oval plate ones.


----------



## Eric M

I'm new to tube amps and my introduction is a Little Dot MK3 that came with Voskhod Rocket 6J1P-EV driver tubes and the stock power tubes.

My first impressions of this new tube sound is that it sounds... gritier? Dirtier? Not as clean as my Topping amp. A bit courser / rougher feel. Would any tube replacements give me a smoother/cleaner sound?


----------



## Yaska729

Eric M said:


> I'm new to tube amps and my introduction is a Little Dot MK3 that came with Voskhod Rocket 6J1P-EV driver tubes and the stock power tubes.
> 
> My first impressions of this new tube sound is that it sounds... gritier? Dirtier? Not as clean as my Topping amp. A bit courser / rougher feel. Would any tube replacements give me a smoother/cleaner sound?


Tube amplifier is there to make distortion, to the good way I supposed. You really won’t be able to be get the clean background like solid state.


----------



## Flex2d

Eric M said:


> I'm new to tube amps and my introduction is a Little Dot MK3 that came with Voskhod Rocket 6J1P-EV driver tubes and the stock power tubes.
> 
> My first impressions of this new tube sound is that it sounds... gritier? Dirtier? Not as clean as my Topping amp. A bit courser / rougher feel. Would any tube replacements give me a smoother/cleaner sound?


ooh start the tube rolling! this is when you discover the perfect sound for your ears!
good luck and have fun

Best

Daniel


----------



## MIKELAP

Eric M said:


> I'm new to tube amps and my introduction is a Little Dot MK3 that came with Voskhod Rocket 6J1P-EV driver tubes and the stock power tubes.
> 
> My first impressions of this new tube sound is that it sounds... gritier? Dirtier? Not as clean as my Topping amp. A bit courser / rougher feel. Would any tube replacements give me a smoother/cleaner sound?
> QUOTE]





Eric M said:


> I'm new to tube amps and my introduction is a Little Dot MK3 that came with Voskhod Rocket 6J1P-EV driver tubes and the stock power tubes.
> 
> My first impressions of this new tube sound is that it sounds... gritier? Dirtier? Not as clean as my Topping amp. A bit courser / rougher feel. Would any tube replacements give me a smoother/cleaner sound?


If memory serves me these were clean sounding i have the tubes but dont have the amp anymore: ELECTRO HARMONIX 6H30Pi and VOSKHOD 6ZHiP-EV .


----------



## Eric M

Yaska729 said:


> Tube amplifier is there to make distortion, to the good way I supposed. You really won’t be able to be get the clean background like solid state.


Yep, I was aware tube amps cause distortion, but I wasn't sure how it would manifest itself until finally trying it. I kept hearing about this "warmer" sound (vs cold and clean modern DAC/amps), but if this distortion is "gritier" sounding to me, then maybe tubes aren't for me.


----------



## Whelkie D

Eric M said:


> Yep, I was aware tube amps cause distortion, but I wasn't sure how it would manifest itself until finally trying it. I kept hearing about this "warmer" sound (vs cold and clean modern DAC/amps), but if this distortion is "gritier" sounding to me, then maybe tubes aren't for me.


Not sure what you mean by "grittier". I found the tube sound definitely warmer and clearer,. The Voskhods have a slightly "brighter" sound compared to some other tubes , but I'm not sure I would describe them as gritty or dirty sounding. I wonder if there is some other issue going on with your amp.


----------



## Flex2d

Eric M said:


> Yep, I was aware tube amps cause distortion, but I wasn't sure how it would manifest itself until finally trying it. I kept hearing about this "warmer" sound (vs cold and clean modern DAC/amps), but if this distortion is "gritier" sounding to me, then maybe tubes aren't for me.


I would try some other tubes, I don’t experience any gritty sound with my little dot mk2 . Quite the opposite! Just added some 6ns7 tube with adapter and osram z77 and it a silky presentation. The sound signature will change a lot with good tubes. The closest I have had to ‘gritty’ is cheap tubes. 
best
Daniel


----------



## bigjako (Aug 16, 2020)

I have had the Little Dot Mk2 for a couple months.  I ordered the 'best' tubes, based on my research, and found some nice ones.  I did the same for my other setup (Darkvoice 336SE), and went down that same path, too.  I will point out that, for the LD, I rarely found 'noisy' tubes in the way that I did for the DV.  I honestly think the DV is the better amp, which is not that crazy a statement.  I keep the DV in my living room as a statement piece, or whatever you wanna call it - it looks awesome, and it generally sounds awesome when you have the right things on it.

Today I recieved these Voshkods: https://www.ebay.com/itm/193246429693?ul_noapp=true

Absolutely bonkers.  They make this LD sound like the big, spacious, and warm DV.  I ordered another matched pair within minutes, in case I lost out on them.  They were sealed like little treasures, and that's how I'm treating them.  I do think they're so much more amazing than the Riverstones that everyone talks about (and I have 2 pairs of).


----------



## Yaska729

Eric M said:


> Yep, I was aware tube amps cause distortion, but I wasn't sure how it would manifest itself until finally trying it. I kept hearing about this "warmer" sound (vs cold and clean modern DAC/amps), but if this distortion is "gritier" sounding to me, then maybe tubes aren't for me.



You might wanna check a few things, Little Dot has a post at their old website and talking about the noise and such, I’ll link below:

http://www.littledot.net/viewtopic.php?f=3&t=597

Hope this helps.


----------



## Datun Walnut (Aug 18, 2020)

Just some notes:
When I first changed from EF95 to EF91 variants, I experienced the low end distortion previously discussed. I put in a pair of socket savers and the distortion disappeared. I can only assume that they subtly changed the impedance somehow.

In my opinion, I've noticed much bigger differences in sound when rolling the the power tubes rather than the little' uns.
When rolling 6SN7GTs, & CV1988s in the differences were massive. I found the EF91, 92 and 95 variants to be a much more subtle change. The difference was there but changing the back line was a smack in the teeth difference. (I'll have to post my findings up as I'm getting quite a collection of EF91 & 95s now)

Has anyone ever tried some 6CG7s in their machines?. They are electrically identical to 6SN7 but have the same 9 pin out as the original 6N6s so should be a drop in replacement.

Finally a pair of 6F8Gs with adaptors has anybody tried these? Come on don't leave it to me to do the heavy lifting - my wife will kill me if I spend any more.


----------



## MIKELAP

Datun Walnut said:


> Just some notes:
> When I first changed from EF95 to EF91 variants, I experienced the low end distortion previously discussed. I put in a pair of socket savers and the distortion disappeared. I can only assume that they subtly changed the impedance somehow.
> 
> In my opinion, I've noticed much bigger differences in sound when rolling the the power tubes rather than the little' uns.
> ...


About 6cg7 .Check page 510 Post  7637  all your question will be answered using the search Function Because while your searching your not spending lol.The 6c8g tube I use in my WA 22 very good tube but can be microphonic. In my Littledot days my last 
setup was 6sn7 and C3g as drivers with my homemade copper adapters.


----------



## Ultrainferno

I see LD is saying the LD-H1 uses 6SN7, but it came equipped with 6SL7GT, which are not interchangeable with 6SN7. Typo or....?


----------



## Datun Walnut

Ultrainferno said:


> I see LD is saying the LD-H1 uses 6SN7, but it came equipped with 6SL7GT, which are not interchangeable with 6SN7. Typo or....?


Weird, I can't see anything anywhere about 6SL7s. Have you tried it with the 6SL7s?


----------



## Ultrainferno

I have only used the 6SL7 so far, but I don't feel like popping in my 6SN7 just to try. I will ask LD and report back


----------



## Ultrainferno

From LD:  "I checked with the engineer, so with the design it is good to run both of these tubes on the machine, and the sound quality would be the same."
They forgot to translate and mention that it can run both 6SN7 and 6SL7 in their communications, so they will be adding that everywhere.
Case solved. Thanks!


----------



## TrollDragon

Ultrainferno said:


> I have only used the 6SL7 so far, but I don't feel like popping in my 6SN7 just to try. I will ask LD and report back


They are only using those tubes in the preamp section so you should be able to swap them without any issue. The 6SN7 has a amplification factor of 20 where the 6SL7 is 70, you will probably need to turn up the volume or gain for the 6SN7s.


----------



## MIKELAP

TrollDragon said:


> They are only using those tubes in the preamp section so you should be able to swap them without any issue. The 6SN7 has a amplification factor of 20 where the 6SL7 is 70, you will probably need to turn up the volume or gain for the 6SN7s.


Exactly i use both


----------



## Datun Walnut

MIKELAP said:


> Exactly i use both


It gives you the chance for a lot more tube rolling fun then


----------



## MIKELAP

Datun Walnut said:


> It gives you the chance for a lot more tube rolling fun then


Oh ya did plenty of that .Result is 4 +vacuum tube caddy's similar to this one filled with these glass beauty's .


----------



## Datun Walnut

MIKELAP said:


> Oh ya did plenty of that .Result is 4 +vacuum tube caddy's similar to this one filled with these glass beauty's .


Wow!


----------



## triod750

Most interesting combination for me in Little Dot MKIVse so far is Siemens C3g as input and Melz 6H12C/6N12S as output. This combination is very transparent. I have tried 6N6P, 5687 and several different 6SN7 brands as output but right now this combination is my favourite. 5687 heaters are about 0,9A and 6H12C 0,95A. I don't use external PSU for this. I have been told that this is safe but can't guarantee it. Little Dot was previously sold with E182CC as output and this is comparable with 5687 regarding heaters.
I mostly listen to acoustical music, jazz and blues. If the music is badly recorded or mixed, these 6H12C are merciless. Mistakes has nowhere to hide as it seems.


----------



## TrollDragon

triod750 said:


> Most interesting combination for me in Little Dot MKIVse so far is Siemens C3g as input and Melz 6H12C/6N12S as output. This combination is very transparent. I have tried 6N6P, 5687 and several different 6SN7 brands as output but right now this combination is my favourite. 5687 heaters are about 0,9A and 6H12C 0,95A. I don't use external PSU for this. I have been told that this is safe but can't guarantee it. Little Dot was previously sold with E182CC as output and this is comparable with 5687 regarding heaters.
> I mostly listen to acoustical music, jazz and blues. If the music is badly recorded or mixed, these 6H12C are merciless. Mistakes has nowhere to hide as it seems.


Nice! I'd like to hear a pair of C3g one day in my MK IV.


----------



## MIKELAP (Sep 2, 2020)

TrollDragon said:


> Nice! I'd like to hear a pair of C3g one day in my MK IV.
> [/QUOTE                                                                                                                                                                               You never made adapters for the C3g?


----------



## TrollDragon

MIKELAP said:


> You never made adapters for the C3g?


No sir, I didn't make any adapters since I don't have any C3gs .


----------



## MIKELAP

TrollDragon said:


> No sir, I didn't make any adapters since I don't have any C3gs .


I still have the copper adapters but sold off all my tubes a few years ago since i cant use them in my WA22 .


----------



## Datun Walnut

My rainy Saturday project: When tube rolling, I was sick of having to remove the bottom of my Little Dot Mk2 headphone amp to change the jumpers between EF91/92 variants and EF95 types. I didn't want to do anything irreversible so I removed one of the unused output RCAs and fitted a locking switch in its place This is then wired to the jumper pins on push fit wires. Let the fun begin!


----------



## MIKELAP (Sep 5, 2020)

Datun Walnut said:


> My rainy Saturday project: When tube rolling, I was sick of having to remove the bottom of my Little Dot Mk2 headphone amp to change the jumpers between EF91/92 variants and EF95 types. I didn't want to do anything irreversible so I removed one of the unused output RCAs and fitted a locking switch in its place This is then wired to the jumper pins on push fit wires. Let the fun begin!


     Ok its MK2 not MK3 i was going to say to get the extended jumpers


----------



## Datun Walnut

It still means taking the case apart though. I can change with the amp in situ in the rack now


----------



## mikeypas

Tube rolling question for the MK3
- been reading a lot, want to try some 6SN7GT for power tube. I understand I would need a 6SN7 to ECC88 adapter.
- also read alot about the c3g driver tubes. I understand I would need a C3G to 6AK5 adapter.
I also read that because of the brass bands on the mk3, I would need extenders or socket savers. 
I read that I would need the socket saver for the c3g (7 pin to 7pin). 
Would I also need for the 6sn7gt??
Does the rest of my info sound correct?


Alot of suggestions with links to ebay for the various 6sn7gt and c3g , however, as they as old, the links no longer work.
Was wondering if anyone had any newer links to suggestions ?


----------



## MIKELAP

mikeypas said:


> Tube rolling question for the MK3
> - been reading a lot, want to try some 6SN7GT for power tube. I understand I would need a 6SN7 to ECC88 adapter.
> - also read alot about the c3g driver tubes. I understand I would need a C3G to 6AK5 adapter.
> I also read that because of the brass bands on the mk3, I would need extenders or socket savers.
> ...


The adapter is the 6SN7 to 6CG7 here, link   https://www.ebay.ca/itm/1PC-Tube-DI...012598?hash=item46ac838ab6:g:IfcAAOSwOoVemDDi                                                                                                                                                                                                          C3g to 6AK5 Adapter       https://www.ebay.ca/itm/2pc-C3G-TO-...974329?hash=item2ee2682f79:g:ZYUAAOSwu4BVwVN8                                                                                                                                                                                                       Yes for extenders what i did is remove the rings they are held in place by 2 screws at 9 oclock and 3 oclock check thread i cut them in 2 there's pictures in the thread. Yes for socket savers because tubes dont fit in the rings .I had made my own adapters so they would fit in ring without removing them .Sounds good .this will help you you know about page 77 for tube rolling ,there is also this good to know page


----------



## MIKELAP

Ring removal= the ring are held in place by 2 screws that are screwed from the inside grind slowly with dremel  so not to damage the shell as you see in picture no need to cut completely to remove them the top of the screws will fall in the amp i removed them  page 728 post 10920


----------



## mikeypas

thank you so much for your reply

is ECC88 and 6CG7 equivalent?
I emailed little dot support directly and they said I should get 6sn7 to ecc88

so the extender for driver tube is 7 pin to 7 pin and the power tube is 9 pin to 9 pin? 




MIKELAP said:


> The adapter is the 6SN7 to 6CG7 here, link   https://www.ebay.ca/itm/1PC-Tube-DI...012598?hash=item46ac838ab6:g:IfcAAOSwOoVemDDi                                                                                                                                                                                                          C3g to 6AK5 Adapter       https://www.ebay.ca/itm/2pc-C3G-TO-...974329?hash=item2ee2682f79:g:ZYUAAOSwu4BVwVN8                                                                                                                                                                                                       Yes for extenders what i did is remove the rings they are held in place by 2 screws at 9 oclock and 3 oclock check thread i cut them in 2 there's pictures in the thread. Yes for socket savers because tubes dont fit in the rings .I had made my own adapters so they would fit in ring without removing them .Sounds good .this will help you you know about page 77 for tube rolling ,there is also this good to know page


----------



## MIKELAP

MIKELAP said:


> Ring removal= the ring are held in place by 2 screws that are screwed from the inside grind slowly with dremel  so not to damage the shell as you see in picture no need to cut completely to remove them the top of the screws will fall in the amp i removed them  page 728 post 10920





mikeypas said:


> thank you so much for your reply
> 
> is ECC88 and 6CG7 equivalent?
> I emailed little dot support directly and they said I should get 6sn7 to ecc88
> ...


I used the 6SN7 to 6CG7 Adapters one or the other. Use what your comfortable with . youll need a pair of 9 pins for power tubes and 7 pins for drivers .WORD OF ADVICE be very careful inserting and removing C3G tubes there are very fragile dont wiggle them when inserting, the glass might crack it happened to me ounce .That said i always left them in the adapters so nothing would happen


----------



## MIKELAP

These are the good socket type                                                                                                                                                                                                             https://www.ebay.ca/itm/2pc-C3G-TO-...974329?hash=item2ee2682f79:g:ZYUAAOSwu4BVwVN8


----------



## gibosi

mikeypas said:


> thank you so much for your reply
> 
> is ECC88 and 6CG7 equivalent?
> I emailed little dot support directly and they said I should get 6sn7 to ecc88
> ...



> is ECC88 and 6CG7 equivalent?

A 6SN7 to ECC88 adapter is identical to a 6SN7 to 6CG7 adapter. The 6SN7 has 8 pins and the ECC88 and 6CG7 have 9 pins. The adapter redirects the 8 pins of the 6SN7 so they can be used in the 9-pin output tube sockets in your amp.

> so the extender for driver tube is 7 pin to 7 pin

The C3g has 8 pins and the 6AK5 has 7 pins. And as above, the adapter redirects the 8 pins of the C3g so they can be used in the 7-pin driver tube sockets in your amp. And as MIKELAP recommends, it is best to leave the C3g permanently inserted in their adapters. So if you want to get another pair of C3g, get another pair of adapters too.


----------



## Datun Walnut (Sep 28, 2020)

.


----------



## TrollDragon

You can't advertise or sell outside of the Classified section. I'd list them there then remove your post.


----------



## Datun Walnut

TrollDragon said:


> You can't advertise or sell outside of the Classified section. I'd list them there then remove your post.


Not sure how to remove the post.


----------



## TrollDragon

Datun Walnut said:


> Not sure how to remove the post.


Sorry, I forgot you can't remove posts here, just edit it and leave a . instead.


----------



## lupoal

Hi, I’ve just added today a couple of 6sn7gtb to my little dot 2 and... wow!
I have one question: what the expected lifespan ? ... as preamplifier i know they can last up to 10000 hours, but as power tubes? 
LD drives Sennheiser HD650, gain 5, typical volume at 12
thks for help


----------



## Datun Walnut

lupoal said:


> Hi, I’ve just added today a couple of 6sn7gtb to my little dot 2 and... wow!
> I have one question: what the expected lifespan ? ... as preamplifier i know they can last up to 10000 hours, but as power tubes?
> LD drives Sennheiser HD650, gain 5, typical volume at 12
> thks for help


I'm using a pair of old Brimar cv1988 and have been for about a year. I'm thinking maybe 200hrs?  Also, to be fair, I've no idea how many hours where on them when I got them. You're right though: wow! They make more of a difference than the driver tubes


----------



## lupoal (Oct 3, 2020)

Datun Walnut said:


> I'm using a pair of old Brimar cv1988 and have been for about a year. I'm thinking maybe 200hrs



 ... those Brimar are quite rare and very expensive (190 - 400 euro matched pair here in Italy... crazy expensive)

but... you mean... 200 or 2000 hours?
as 200 hours are maybe 4 moth operating time (I mean how I will use them)... it would be a nightmare


----------



## Nooborghini

Does anyone have the MK8 / MK VIII with rolled tubes?
I was thinking of replacing my Little Dot Mk 2 w/ CV4010 as my setup has evolved into a pair of HD800 and HD820s.
Deciding between the MK8 vs WA22. 

My MK 2 right now is great but I still prefer the clarity of my SP200 amp as my MK 2 loses clarity but in turn, has a bit more distorted bass.

Any suggestions?


----------



## Datun Walnut

lupoal said:


> ... those Brimar are quite rare and very expensive (190 - 400 euro matched pair here in Italy... crazy expensive)
> 
> but... you mean... 200 or 2000 hours?
> as 200 hours are maybe 4 moth operating time (I mean how I will use them)... it would be a nightmare


I meant I'd used them about 300 hours so far plus what was on them when I got them. I hope they don't burn out soon as I love them so much. I was very lucky to get two pairs in a box of mixed tv tubes. 
I've notice Farranti 6sn7gt are the same as the Brimar but with a different badge. One was going on UK ebay for approx 80euros. I already have one. And don't know whether to sell it or buy the other to make a pair. I like Sylvanias too. Very neutral and cheaper


----------



## TrollDragon

lupoal said:


> Hi, I’ve just added today a couple of 6sn7gtb to my little dot 2 and... wow!
> I have one question: what the expected lifespan ? ... as preamplifier i know they can last up to 10000 hours, but as power tubes?
> LD drives Sennheiser HD650, gain 5, typical volume at 12
> thks for help


The Little Dot is a preamp, the headphone jack and RCA line outs are in parallel so the term power tubes is a bit of a misnomer. I prefer to call them output tubes as they are no different than what is used in a tube preamp (milliwatts of output) and don't have the same stress put on them like regular power tubes would have.  So I wouldn't worry too much about stressing the tubes, my 6H30Pi EH outputs have been in my MK IV since it arrived 6+ years ago.

I use my amp for music and gaming 6-8 hours a day with DT880 250 ohm, gain of 5 and volume somewhere between 11 and 1.


----------



## lupoal (Oct 3, 2020)

@TrollDragon ... thank you! that's a very positive news for me... with 6N6P (Foton... I've some matched pairs of those.. all NOS) I used to power on the LD roughly two hours before start listening music as I discovered that was the right warm up time to have the best performance, now with these 6SN7GTB I was scared ... but now I'm fine, I will buy another couple matched pair NOS but not in a hurry, just as spare part.
thanks again.


----------



## TrollDragon

lupoal said:


> @TrollDragon ... thank you! that's a very positive news for me... with 6N6P (Foton... I've some matched pairs of those.. all NOS) I used to power on the LD roughly two hours before start listening music as I discovered that was the right warm up time to have the best performance, now with these 6SN7GTB I was scared ... but now I'm fine, I will buy another couple matched pair NOS but not in a hurry, just as spare part.
> thanks again.


You are welcome. 
Don't worry about the longevity of tubes, eventually some will stop working and you just replace them. It's always good idea to have spares of the ones you like. 

You also don't need to specifically seek out matched pairs of tubes for the Little Dot amp. Matched pairs are a must have in push pull amps to keep the plate current draw equal on both tubes, if they are not equal one of the tubes will dissipate more power and can burn out prematurely. The Little Dot amps are not configured in a push pull arrangement and do not require matched tubes. Some sellers will use the term matched in the ads just so they can charge more for the tubes.

If your amplifer has two or more output tubes per channel then you should purchase matched sets, the Little Dot amps in this thread only use one output tube per channel so matching is not required. Just something to keep in mind, it won't hurt buying matched pairs but you don't need to pay extra for that service if a seller offers it.


----------



## MIKELAP

lupoal said:


> ... those Brimar are quite rare and very expensive (190 - 400 euro matched pair here in Italy... crazy expensive)
> 
> but... you mean... 200 or 2000 hours?
> as 200 hours are maybe 4 moth operating time (I mean how I will use them)... it would be a nightmare


Research match pairs in this thread you wont get any recommendation to do so .


----------



## Datun Walnut

MIKELAP said:


> Research match pairs in this thread you wont get any recommendation to do so .


Mine aren't really matched to any great degree - I tested all four Brimars and put them together as best I could ( though they are still out a bit on Gm and anode current) and they sound fantastic.


----------



## lupoal

thank to all for help 

"matching pair" was a temptative to filter junk stuff, some people I know in hi-fi business told me real NOS are almost over... and I can't test tubes... yesterday searching in ebay I found a 6SN7 with printed on the glass "made in China" and perfect T shape black plates, angled, inside 

anyway... at the moment my LD2 has two 6HM5, long version made in Jugoslavia, and two 6SN7GTB no brand on glass but for sure Sylvania... I've found some potentially interesting tubes in ebay... 

one is Sylvania




then another one ...




and then a nice couple of RCA...




any suggestion?
what does it mean "ANF" ?


----------



## Datun Walnut

lupoal said:


> thank to all for help
> 
> "matching pair" was a temptative to filter junk stuff, some people I know in hi-fi business told me real NOS are almost over... and I can't test tubes... yesterday searching in ebay I found a 6SN7 with printed on the glass "made in China" and perfect T shape black plates, angled, inside
> 
> ...


I've got cheap Soviet 6sn7s that look internally like Sylvanias and sound almost the same £15 a pair. Bargain


----------



## TrollDragon

lupoal said:


> what does it mean "ANF" ?


Do you have a link?


----------



## lupoal (Oct 4, 2020)

it's printed on the tube, pls see above... the 2nd picture ... ANF USA (?)

I've found also another interesting tube...




sylvania or Tung-sol? ... same price and similar plates, diferent mica spacer, the bottom one, sound?... boh


----------



## MIKELAP

.


----------



## gibosi

lupoal said:


> it's printed on the tube, pls see above... the 2nd picture ... ANF USA (?)
> 
> I've found also another interesting tube...
> 
> ...



Regarding the Sylvania code, ANF, unfortunately, I have yet to find the key to deciphering this three-letter code. What I can say is the first digit, "A" indicates the factory at Altoona, PA. But again, the precise meaning of the remaining two letters is not known to me. However, the font and graphics on these tubes suggests that they were manufactured between 1979 and 1983.

The Tung Sol with the open date code on the right indicates this tube was labeled and shipped in 1956, week 47. While I do not  have any information on Tung -Sol's two-letter date code on the left, the fact that the construction appears to be identical to that on the right suggests that it was manufactured about the same time.


----------



## lupoal

Thank a lot gibbosi,

then I will go for Tung-sol that are old enough to be... old enough (let hope they are true *New* Old Stock) !


----------



## lupoal (Oct 5, 2020)

... wait a moment... I'm only looking for GTB types as... are GT verion compatible with LD2 ?


----------



## Datun Walnut

lupoal said:


> ... wait a moment... I'm only looking for GTB types as... are GT verion compatible with LD2 ?


I'm running GTs with no problems


----------



## gibosi

lupoal said:


> ... wait a moment... I'm only looking for GTB types as... are GT verion compatible with LD2 ?



As above, GT, GTA and GTB are all compatible with your LD2.


----------



## lupoal (Oct 7, 2020)

fantastic!
now... with my 6HM5 + Sylvania I'm having low frequencies a little too long, a little muddy, especially with classical music... orchestra... for example the last movement of Bruckner Symphony #1 when there is a big mass, big impact... texture in low frequency get lost, it was different with Foton 6N6P... less musical, with less armonics and more glare highs, but better texture/control in low frequency, more fast and punchy

so I tried changing the 6HM5 with Voskhod 5654 with terrible result, simply unlistenable... I stiil have to try with Mullard M8100, I think these are too bassy so not the right choise... GE JAN 5654... Siemens 5654, these are very dry with the middle, maybe too dry... EK90 Telefunken... boh

what could be in your experience a 6SN7 having the same musicality as the Sylvania but more controlled on low frequencies?
GE... RCA... Tung sol... Brimar... uff...


----------



## Datun Walnut

lupoal said:


> fantastic!
> now... with my 6HM5 + Sylvania I'm having low frequencies a little too long, a little muddy, especially with classical music... orchestra... for example the last movement of Bruckner Symphony #1 when there is a big mass, big impact... texture in low frequency get lost, it was different with Foton 6N6P... less musical, with less armonics and more glare highs, but better texture/control in low frequency, more fast and punchy
> 
> so I tried changing the 6HM5 with Voskhod 5654 with terrible result, simply unlistenable... I stiil have to try with Mullard M8100, I think these are too bassy so not the right choise... GE JAN 5654... Siemens 5654, these are very dry with the middle, maybe too dry... EK90 Grundig... boh
> ...


I'd avoid Brimar. To me, I always thought the Sylvanias were very neutral. I've got Brimars and they have a lot of bass I suspect you wouldn't like them as it's a very rich sound and not too controlled. I love them but it's a hell of a price to buy a pair of old ones to find out they aren't for you. I like Mullard CV4014 I think they give good bass when combined with Sylvanias


----------



## lupoal (Oct 6, 2020)

this kind of 4014 ...






or





or





... these are all "Mullard 4014" in ebay... as usual, for a rookie like me, a mess


----------



## Datun Walnut

lupoal said:


> this kind of 4014 ...
> 
> 
> 
> ...


I've not trued the m8083s. I understand that they are a special quality version of the CV4014. Though they look the same internally. Mine are the blue glass Mullards. Don't confuse them with Mullard blue glass EF91 though, they aren't as nice to my ears as the CVs.


----------



## lupoal

ok, so I have to get the first one... not cheap but not crazy expensive, are roughly 15$ each + shipment


----------



## Datun Walnut

My mate is insisting that an ECC88 will drop in to the power sockets on the Mk2. Looking at the datasheet, they are pin compatible with the 6n6. The Ih is higher (but considering I'm running 6sn7gts that shouldnt be a problem). As far as I can tell they seem quite similar but my Cyrillic isn't too hot for reading the 6n6p datasheet. Anybody had any experience?


----------



## triod750

You can use them but they are not very powerful for use as ouput tubes. The sound is clean but lacking.


----------



## triod750

If you want to try something else than 6N6P and 6SN7 I would suggest 5687 or Melz 6H12C/6N12S. Both of these need adapters but the latter uses the same adapter as 6SN7. I have tried Brimar, Melz, Ken-Rad, Raytheon, RCA and Sylvania 6SN7 tubes but prefer 6H12C/6N12S. I have had best result with C3g as input. They need their own adapter. All these tubes run on original transformer in my LD MKIVSE.


----------



## lupoal

so I placed orders for Tung-sol and CV4014... in the mean time I tryied some other alchemy (all NOS)... GE JAN 5654, bad, poor low frequencies, no soundstage... Siemens 5654 harsh, dry, no bass... at the end Grundig EK90 and... et voilà! bass controlled and with texture, not very deep, good sound stage, wide and deep, good instrument separation... so at the moment these EK90 are the better alternative to 6HM5, as EK still have to partially do burn in I hope they will get also the musicality that 6HM5 have that is partially missing at the moment

and then we will see what happen with the new tubes are coming... have to wait one week


----------



## lupoal

thank you triod750 

I will also look for Metz... I hope they will be reasonably cheap like this damn LD2 is costing me a lot of money because of the "tube rolling crazyness"...


----------



## Datun Walnut (Oct 6, 2020)

lupoal said:


> thank you triod750
> 
> I will also look for Metz... I hope they will be reasonably cheap like this damn LD2 is costing me a lot of money because of the "tube rolling crazyness"...


Tell me about it. This is just a bit of my collection of tubes for the little dot. - not counting my selection of 6SN7GTs both modern and old and the tubes for my other amps, DAC and CD player. It's been fascinating playing with them and hearing the difference and I've modified the amp now so that I can change from Ef95 to ef91 types without taking the case apart. My current favourites are Old CV1988 back line with NOS Mullard EF95 front end. The Metz will have to wait this month.


----------



## TrollDragon

@MIKELAP and I were just reminiscing about a member of this group and his LD amp he modified for better cooling.






bbmiller... I wonder what ever happened to him or if he burnt his house down by running his amp 24/7 because it sounded better when left on.


----------



## Datun Walnut

TrollDragon said:


> @MIKELAP and I were just reminiscing about a member of this group and his LD amp he modified for better cooling.
> 
> 
> 
> ...


Jeeze. Classy bit of work that. 
To be fair I have thought about recasing mine. It would allow more room for Mundorf caps and a bigger transformer.


----------



## triod750

You are a true enthusiast when you go all in like that but maybe Mordy's fans were wiser. I don't remember what tubes he used but heat hasn't been a problem for me, so far.


----------



## TrollDragon

Datun Walnut said:


> Jeeze. Classy bit of work that.
> To be fair I have thought about recasing mine. It would allow more room for Mundorf caps and a bigger transformer.


Yes he was an odd duck for sure. 
There have been a few in the group that have used bigger cases.


----------



## Datun Walnut

triod750 said:


> You are a true enthusiast when you go all in like that but maybe Mordy's fans were wiser. I don't remember what tubes he used but heat hasn't been a problem for me, so far.


No, can't say I've had a problem. If I can find a cheap 'spares or repair' one on ebay, I might have a go.


----------



## TrollDragon

triod750 said:


> You are a true enthusiast when you go all in like that but maybe Mordy's fans were wiser. I don't remember what tubes he used but heat hasn't been a problem for me, so far.


He ran stock tubes.


----------



## Datun Walnut

TrollDragon said:


> He ran stock tubes.


I wonder what the rest of his system was like?


----------



## TrollDragon

Datun Walnut said:


> I wonder what the rest of his system was like?


I forget, but he was a little hard on the head. You can search his old posts, bbmiller was his username.


----------



## triod750

TrollDragon said:


> He ran stock tubes.



Stock tubes make the amp hotter than 5687, 6SN7 or 6H12C do. The adapters isolate a lot of the heat from the chassis.


----------



## MIKELAP

TrollDragon said:


> @MIKELAP and I were just reminiscing about a member of this group and his LD amp he modified for better cooling.
> 
> 
> 
> ...


            Man what a waste .Better off buying a better Amp .Extreme modding that's for sure


----------



## TrollDragon

triod750 said:


> Stock tubes make the amp hotter than 5687, 6SN7 or 6H12C do. The adapters isolate a lot of the heat from the chassis.


The problem was he wanted to run his LD 24/7 and we advised him against that. I would never leave a tube amp running unattended.


----------



## Datun Walnut

TrollDragon said:


> The problem was he wanted to run his LD 24/7 and we advised him against that. I would never leave a tube amp running unattended.


No. Not a clever thing to do.


----------



## lupoal (Oct 7, 2020)

Datun Walnut said:


> ...and I've modified the amp now so that I can change from Ef95 to ef91 types without taking the case apart. ...



interesting!
could you post details/picture about this mod? did you also change the capacitors at the output?
... I was thinking to remove the transformer, maybe replacing it with something more audio-grade and more powerful, and put it in an external housing to avoid vibration transmission to the valves, then between the transformer and the mechanics of the LD a cable with a female MIL connector (the green ones) and a male MIL connector on a small plate to close the hole in the housing of the LD... but it is just another crazy thought (well... not so crazy, it is a solution you can find in many high quality dac and ampli, for example Estro Armonico https://www.ilgazeboaudiofilo.com/t27363-ampli-estroarmonico-otl-signature )


----------



## Datun Walnut

lupoal said:


> interesting!
> could you post details/picture about this mod? did you also change the capacitors at the output?
> ... I was thinking to remove the transformer, maybe replacing it with something more audio-grade and more powerful, and put it in an external housing to avoid vibration transmission to the valves, then between the transformer and the mechanics of the LD a cable with a female MIL connector (the green ones) and a male MIL connector on a small plate to close the hole in the housing of the LD... but it is just another crazy thought (well... not so crazy, it is a solution you can find in many high quality dac and ampli, for example Estro Armonico https://www.ilgazeboaudiofilo.com/t27363-ampli-estroarmonico-otl-signature )


No, it's not crazy. The LDs are great amps and would respond well to modding. I didn't want to drill the case at all on my mod. So I removed one of the audio out RCAs and fitted a dpdt switch (locking type to avoid dusting accidents) in its place. I then ran wires with little push fit connectors back to the jumper positions on the PCB. Some people have experienced hum doing this but my machine is silent. I'd like to change the caps to better but space is an issue. My favourite budget caps are Russian PIOs bypassed with a low value polystyrene. I've used them on my CD mod and highs sparkle. Sadly, I'd never find space for them in an LD.


----------



## lupoal (Oct 7, 2020)

thank you! very interesting
I've seen somewhere a mod with different caps, they barely fit in but seems was ok.... here
I've read somewhere else that the most useful mod was about power supply capacitors instead of output caps, I tried some tuning adding mass to LDII to lower resonance frequencies or dumping feets... but it never liked those care with, as result, dryer sound and, mainly, poorer bass
so because of that I'm a little scared in removing the transformer ... in the meantime talking with and audio engineer, in the field with success since decades, he explained me how important can be transformers in audio application and how big are differencies between transformers for common use and dedicated one (in terms of material, geometry, etc.) ... as this kind of transformers can cost easily more then the entire LD2 I'm thinking that all our games/efforts could are probably limited in results by poor quality transformer installed

in the meantime, to keep everything as fun and simple as possible I've done one of this ... is in burn-in now, under the fridge in the kitchen


----------



## TrollDragon

I installed switches in my MK IV to facilitate easy tube rolling, unfortunately they induced hum and microphonics. Too bad as it was very convenient.

Red up EF92, Black switches disabled.
Red down EF95, Black toggle strapping 1-7, NS or 2-7.

If the MK IV was easy to work on like the MK II, I would have tried to correct the problem. With the MK IV you have to unsolder the transformer to remove the board, then put it all back together for testing each time.


----------



## Datun Walnut

TrollDragon said:


> I installed switches in my MK IV to facilitate easy tube rolling, unfortunately they induced hum and microphonics. Too bad as it was very convenient.
> 
> Red up EF92, Black switches disabled.
> Red down EF95, Black toggle strapping 1-7, NS or 2-7.
> ...


Shame. It's a nice looking mod.


----------



## TrollDragon (Oct 7, 2020)

lupoal said:


> thank you! very interesting
> I've seen somewhere a mod with different caps, they barely fit in but seems was ok.... here
> I've read somewhere else that the most useful mod was about power supply capacitors instead of output caps, I tried some tuning adding mass to LDII to lower resonance frequencies or dumping feets... but it never liked those care with, as result, dryer sound and, mainly, poorer bass
> so because of that I'm a little scared in removing the transformer ... in the meantime talking with and audio engineer, in the field with success since decades, he explained me how important can be transformers in audio application and how big are differencies between transformers for common use and dedicated one (in terms of material, geometry, etc.) ... as this kind of transformers can cost easily more then the entire LD2 I'm thinking that all our games/efforts could are probably limited in results by poor quality transformer installed
> ...


Output transformers in OTC tube amps are very important and usually make up the majority of the cost of those amps.  The Little Dot MK 2/3/4 only uses a power transformer since it is OTL and should only affect the sound if it is not providing enough power, changing it would probably do nothing for you except possibly provide higher filament current to run 6AS7G or 6080 output tubes.

The power transformer in the Little Dot is a custom wound transformer with no off the shelf replacements available, so one needs to be careful rolling tubes that you don't draw too much current from the filament windings.  Trying to incorporate a different transformer would require modifications to the power supply circuit of the amp.

If you are looking to turn your amp into something similar to the Woo WA6SE you might be better served actually picking up a WA6SE.


----------



## TrollDragon

Datun Walnut said:


> Shame. It's a nice looking mod.


Yes I was quite stoked to incorporate it and if the MK IV didn't him when out of the case it would have been an easy fix.


----------



## lupoal

Telefunken EK90 + Sylvania 6SN7GTB --> amazing !


----------



## Datun Walnut

lupoal said:


> Telefunken EK90 + Sylvania 6SN7GTB --> amazing !


I've not heard an EK90. I suppose I'll have to buy more valves now.


----------



## gibosi

Datun Walnut said:


> I've not heard an EK90. I suppose I'll have to buy more valves now.



Have fun! 

https://www.head-fi.org/threads/lit...ube-rolling-guide.563884/page-77#post-9392055


----------



## lupoal

ok, the TNT TTS cable burn-in is over and I tested it and... do yourself a big favour, try it... the change in performance are simply unbelievable, at least for me that I'm cable skeptic... but... wow

here are very few words about it in an italian forum (google translator will help you easily)
--> click


----------



## Datun Walnut (Oct 9, 2020)

lupoal said:


> ok, the TNT TTS cable burn-in is over and I tested it and... do yourself a big favour, try it... the change in performance are simply unbelievable, at least for me that I'm cable skeptic... but... wow
> 
> here are very few words about it in an italian forum (google translator will help you easily)
> --> click


I'm afraid it won't sound good on mine - it went 'phut!' last night. LED flickers slightly on power up and there's a massive hum.


----------



## lupoal

really? 

that cable? there must be something wrong somewhere... did you checked it for short circuit? 
if "electrically" is fine it should give you in the worst case... nothing... not that bad result


----------



## Datun Walnut

lupoal said:


> really?
> 
> that cable? there must be something wrong somewhere... did you checked it for short circuit?
> if "electrically" is fine it should give you in the worst case... nothing... not that bad result


I'm thinking the power supply side of things as the LED is off. I've ordered a capacitor tester. The smoothing caps are rated at 250v max yet the schematic shows the transformer has 175v output. After smoothing that dangerously close to the max of the cap. 
I'm gutted, I love my liitle dot.


----------



## Arro

Great thread. I've using it as a reference to get the most out of my I+ and my MKIVSE.

Recently I've been looking at other Russian double triodes that might work as output tubes and I came across the 6N26P (6Н26П) among a few others. It can currently be found on eBay for around $30 a pair and is being sold as a 6H30P-DR alternative. It draws less heater current than a 6N6P but it has a plate voltage of 150, compared to the 6N6P's plate voltage of 120. It's pin out appears to be the same as the 5670. Would the 6N26P be safe to use in the Little Dot amps?
This is the closest I've come to finding a data sheet - http://www.russiantubes.com/prop.php?t=12&p=230


----------



## gibosi

Arro said:


> Great thread. I've using it as a reference to get the most out of my I+ and my MKIVSE.
> 
> Recently I've been looking at other Russian double triodes that might work as output tubes and I came across the 6N26P (6Н26П) among a few others. It can currently be found on eBay for around $30 a pair and is being sold as a 6H30P-DR alternative. It draws less heater current than a 6N6P but it has a plate voltage of 150, compared to the 6N6P's plate voltage of 120. It's pin out appears to be the same as the 5670. Would the 6N26P be safe to use in the Little Dot amps?
> This is the closest I've come to finding a data sheet - http://www.russiantubes.com/prop.php?t=12&p=230



While it is certainly safe, with the heater drawing only 0.6amps, I suspect that it will be somewhat under-powered as an output tube, similar to a 6SN7GT.


----------



## TrollDragon

Datun Walnut said:


> I'm thinking the power supply side of things as the LED is off. I've ordered a capacitor tester. The smoothing caps are rated at 250v max yet the schematic shows the transformer has 175v output. After smoothing that dangerously close to the max of the cap.
> I'm gutted, I love my liitle dot.


Check to see if you have AC off of the transformer and what is coming out of the DC side, possibly fried the bridge rectifier... Should be easy enough to hunt down.


----------



## mikeypas

Took a long time to get everything from ebay, but finally got the setup i"m very happy with. Thanks to everyone for guidance and help! 
6SN7GT VT-231 JAN Sylvania and C3G Siemens
Adapters and socket savers as I did not remove the gold rings.
Sounding great!


----------



## MIKELAP

Arro said:


> Great thread. I've using it as a reference to get the most out of my I+ and my MKIVSE.
> 
> Recently I've been looking at other Russian double triodes that might work as output tubes and I came across the 6N26P (6Н26П) among a few others. It can currently be found on eBay for around $30 a pair and is being sold as a 6H30P-DR alternative. It draws less heater current than a 6N6P but it has a plate voltage of 150, compared to the 6N6P's plate voltage of 120. It's pin out appears to be the same as the 5670. Would the 6N26P be safe to use in the Little Dot amps?
> This is the closest I've come to finding a data sheet - http://www.russiantubes.com/prop.php?t=12&p=230


I use these tubes (6N26P)with my WA22 with  5670 to 6SN7 adapters its a very nice sounding tube can also use 5670,6N3P,396A ,according to my notes


----------



## MIKELAP (Oct 9, 2020)

I remember liking the 6AU6 tubes alot bought 6AU6 to 6AK5 adapters for them and many tubes .Here are some of them


----------



## lupoal

talking about 6BE6... I have couple of Telefunken but no way to find some more (well, at cray price of 33 euro/each are available... I'm not available for that as I paid roughly 4,50 euro/each for those I have) but there are many other brands avaliable... looking for nos and excluding Siemens, too hard, and Mullard, maybe too boomy/soft, wich other brand could be similar to TFK I have?
btw... I've received the CV4014... as soon as I feel like opening the LD and setting in EF91 I will see if/how well they sound... to be beautiful they are beautiful


----------



## mab1376 (Oct 10, 2020)

6av6 was a personal fav of mine until I got some c3gs. requires snipping 2 pins and ef92 jumper settings.

I have a set of Mullard 10m series that sound very rich in bass with sweet highs and forward mids. Ideal for HD650.

https://www.head-fi.org/threads/little-dot-tube-amps-vacuum-tube-rolling-guide.563884/post-9709904


----------



## Datun Walnut

mab1376 said:


> 6av6 was a personal fav of mine until I got some c3gs. requires snipping 2 pins and ef92 jumper settings.
> 
> I have a set of Mullard 10m series that sound very rich in bass with sweet highs and forward mids. Ideal for HD650.
> 
> https://www.head-fi.org/threads/little-dot-tube-amps-vacuum-tube-rolling-guide.563884/post-9709904


When I've my LD is running properly again, I must get some C3Gs.


----------



## MIKELAP

mab1376 said:


> 6av6 was a personal fav of mine until I got some c3gs. requires snipping 2 pins and ef92 jumper settings.
> 
> I have a set of Mullard 10m series that sound very rich in bass with sweet highs and forward mids. Ideal for HD650.
> 
> https://www.head-fi.org/threads/little-dot-tube-amps-vacuum-tube-rolling-guide.563884/post-9709904


Yup 6AV6 was also a favorite of mine


----------



## cddc

mab1376 said:


> 6av6 was a personal fav of mine until I got some c3gs.* requires snipping 2 pins* and ef92 jumper settings.
> 
> I have a set of Mullard 10m series that sound very rich in bass with sweet highs and forward mids. Ideal for HD650.
> 
> https://www.head-fi.org/threads/little-dot-tube-amps-vacuum-tube-rolling-guide.563884/post-9709904




That is blasphemy to tube addicts like me...LOL 😉


----------



## TrollDragon

I didn't care much for the 6AV6 or 6AT6 way too bright for me.

And don't forget how to count when cutting off the pins with the Dremel...


----------



## cddc

Instead of snipping off 2 pins, I think it is better to use 2 adapters where you disconnect the 2 pins inside. 

That way you will have 2 new tubes when the 2 halves in use are depleted many years later. Just switch left and right, and you will have 2 new tubes.

Snipping 2 pins off is just a waste of tubes and blasphemy to me


----------



## TrollDragon

cddc said:


> Instead of snipping off 2 pins, I think it is better to use 2 adapters where you disconnect the 2 pins inside.
> 
> That way you will have 2 new tubes when the 2 halves in use are depleted many years later. Just switch left and right, and you will have 2 new tubes.
> 
> Snipping 2 pins off is just a waste of tubes and blasphemy to me


The tubes weren't that special, also finding B7G socket savers to modify is just about impossible.


----------



## TrollDragon

After today I'm off till Wednesday, so I think it will be time to pull the tube cage from the MK IV drivers and install the pair of C3g.


----------



## triod750

Then you will have to give them time to show their best. I believe that a lot of people jump to conclusions when evaluating the qualities of newly installed tubes. They don't give them enough time to show their colours. I have used my Melz 6H12C/6N12S about 200 hours by now and imagine that they are still getting incrementally better. I wasn't very impressed by the C3g from the beginning but they changed and kept on changing. At least they changed my view of them. No mean feat.


----------



## gibosi (Oct 10, 2020)

cddc said:


> Instead of snipping off 2 pins, I think it is better to use 2 adapters where you disconnect the 2 pins inside.
> 
> That way you will have 2 new tubes when the 2 halves in use are depleted many years later. Just switch left and right, and you will have 2 new tubes.
> 
> Snipping 2 pins off is just a waste of tubes and blasphemy to me



It is worth noting that the 6AT6 (and 6AQ6 and 6AV6) are double diode-triodes. That is, there is one triode and two diodes inside each bottle. They are not double triodes so the notion that after some years, you can simply switch the left and right sections and have two new tubes isn't valid. In order to use them in the LD, you have to somehow disconnect those diodes. And while cutting off pins 5 and 6 could be called "butchering", it's cheap, expeditious and it works. lol


----------



## TrollDragon

triod750 said:


> Then you will have to give them time to show their best. I believe that a lot of people jump to conclusions when evaluating the qualities of newly installed tubes. They don't give them enough time to show their colours. I have used my Melz 6H12C/6N12S about 200 hours by now and imagine that they are still getting incrementally better. I wasn't very impressed by the C3g from the beginning but they changed and kept on changing. At least they changed my view of them. No mean feat.


I intend to give them just that, really looking forward to it.


----------



## MIKELAP

TrollDragon said:


> I didn't care much for the 6AV6 or 6AT6 way too bright for me.
> 
> And don't forget how to count when cutting off the pins with the Dremel...


That's what i liked about them crisp and clean .  Still have alot of them but didnt cutoff the pins did that as needed. LD has been gone a few years now


----------



## cddc

gibosi said:


> It is worth noting that the 6AT6 (and 6AQ6 and 6AV6) are double diode-triodes. That is, there is one triode and two diodes inside each bottle. They are not double triodes so the notion that after some years, you can simply switch the left and right sections and have two new tubes isn't valid. In order to use them in the LD, you have to somehow disconnect those diodes. And while cutting off pins 5 and 6 could be called "butchering", it's cheap, expeditious and it works. lol




Thought 6av6 is a dual triodes  and folks cut pins to use half of it.

Anyway feeling bad when I heard snipping tube pins...


----------



## MIKELAP

cddc said:


> Thought 6av6 is a dual triodes  and folks cut pins to use half of it.
> 
> Anyway feeling bad when I heard snipping tube pins...


That's called R&D lol


----------



## cddc (Oct 10, 2020)

MIKELAP said:


> That's called R&D lol



R&D is fine, but don't cut the pins please ...need to R&D some other way to avoid snipping pins


----------



## cddc

TrollDragon said:


> I didn't care much for the 6AV6 or 6AT6 way too bright for me.
> 
> And don't forget how to count when cutting off the pins with the Dremel...



Thou I hate snipping tube pins, the soldering job in the pic was well done


----------



## Datun Walnut (Oct 13, 2020)

Can anyone explain to me what the jumpers do when swapping between ef95 and EF91 tubes? As far as I can make out, for EF91 the jumper connects the cathode to the g3. Whereas the jumper is off for EF95 as the connection is already made in the tube. Am I correct?


----------



## TrollDragon

Datun Walnut said:


> Can anyone explain to me what the jumpers do when swapping between rf91 and EF91 tubes? As far as I can make out, for EF91 the jumper connects the cathode to the g3. Whereas the jumper is off for EF95 as the connection is already made in the tube. Am I correct?


Pins 5 (anode) and 6 (grid) are permanently connected to each other on the board. The jumper bridges pin 7 to that arrangement for EF92 tubes to tie up g3 so it's not floating.  The jumper is not installed in EF95 mode as pin 7 is tied to the cathode on pin 2 and bridging that jumper would short the anode to the cathode.

Here is a good read on strapping pentodes as triodes which is what we use in the Little Dot.
http://www.audiodesignguide.com/New2A3/ETF06TS.pdf


----------



## triod750

Only trouble with this reply is that one has to really understand what is written. To some of us that is a problem. Even if we understand every single word we can have difficulties interpreting what they mean together


----------



## Datun Walnut

triod750 said:


> Only trouble with this reply is that one has to really understand what is written. To some of us that is a problem. Even if we understand every single word we can have difficulties interpreting what they mean together


We're all learning. I'm slow but getting there.


----------



## Datun Walnut

TrollDragon said:


> Pins 5 (anode) and 6 (grid) are permanently connected to each other on the board. The jumper bridges pin 7 to that arrangement for EF92 tubes to tie up g3 so it's not floating.  The jumper is not installed in EF95 mode as pin 7 is tied to the cathode on pin 2 and bridging that jumper would short the anode to the cathode.
> 
> Here is a good read on strapping pentodes as triodes which is what we use in the Little Dot.
> http://www.audiodesignguide.com/New2A3/ETF06TS.pdf


I'll DL that and have a read. Thank you. I have a small but useful homebuilt triode tester. I'm wondering I'd I made a box with a 7 pin socket on strapped up like a triode, I could test my pentodes.


----------



## TrollDragon

Datun Walnut said:


> I'll DL that and have a read. Thank you. I have a small but useful homebuilt triode tester. I'm wondering I'd I made a box with a 7 pin socket on strapped up like a triode, I could test my pentodes.


I can't see why that wouldn't work.


----------



## TrollDragon

triod750 said:


> Only trouble with this reply is that one has to really understand what is written. To some of us that is a problem. Even if we understand every single word we can have difficulties interpreting what they mean together


I could have included pinouts of EF92 and EF95 tubes to show the difference of how they are wired up internally.  The jumper on the board of the LD allows us to use both types of tubes.


----------



## triod750

TrollDragon said:


> I could have included pinouts of EF92 and EF95 tubes to show the difference of how they are wired up internally.  The jumper on the board of the LD allows us to use both types of tubes.



You did fine. It's difficult to teach blockheads.


----------



## lupoal (Oct 18, 2020)

my two tungsol 6SN7GTB, are driven by two CV4014 (thank you Datum Walnut!) and... they sound really fine but... the two tubes seems to have (well, I think they have) a quite different operating temperature, I swipped the tubes between the two position and the hotter one is always the same (tube, not position), I've done the same with the CV4014 (thinking could be from differences in those but no, the hotter 6SN7 remain unchanged)...here is a picture, what do you think about? all normal or one of the tubes is fault?


----------



## Datun Walnut

lupoal said:


> my two tungsol 6SN7GTB, are driven by two CV4014 (thank you Datum Walnut!) and... they sound really fine but... the two tubes seems to have (well, I think they have) a quite different operating temperature, I swipped the tubes between the two position and the hotter one is always the same (tube, not position), I've done the same with the CV4014 (thinking could be from differences in those but no, the hotter 6SN7 remain unchanged)...here is a picture, what do you think about? all normal or one of the tubes is fault?


Do you have a multimeter? Can you check the heater voltages on the sockets. They should be 6.3v or there abouts (mine are 6.5) if it the fault moves with the valve it's probably the valve itself. Sometines the heater wire might be slightly different. You could measure the resistance across the heater pins and see if the is a difference between the two valves. I can send you the pin details if it will help.


----------



## lupoal (Oct 18, 2020)

Datun Walnut said:


> I can send you the pin details if it will help



yes please,
how do you measure the heater voltage? do you remove valve and measure inside the socket (I mean the adapter) or do you opend the LD and measure it on the pcb soldering point? (much more dangerous)


----------



## lupoal

... so here...





between 7 and 8... so, looking at from the bottom to the valve the first two pins moving in counterclowise direction... right?
unfortunately no way to measure each heater inside as they are in parallel on noly two pins (and two resistors in parallel... well the gap in the values could be higher then evaluated via multimeter)


----------



## TrollDragon

If the tubes sound good I really wouldn't worry about one filament brighter than the other.


----------



## lupoal

in the mean time I've measured the voltage at the heater... it is roughly 6,7Vac (the voltage at home is 240Vac instead of the nominal 220Vac)
I've tried also to get the value of resistance between pin 7 and 8 but no way... I always get 0... tested both Tungsl and both Sylvania... always 0 but there is electrical continuity as testing for that I get a nice "beeeep" from multimeter


----------



## Datun Walnut

lupoal said:


> yes please,
> how do you measure the heater voltage? do you remove valve and measure inside the socket (I mean the adapter) or do you opend the LD and measure it on the pcb soldering point? (much more dangerous)


I'll put something together for you. Do you have a multimeter?


----------



## lupoal

Datun... please read two messages above... I've measured the voltage and is 6,7Vac... no way for the heater impedance, between 7 and 8 always 0


----------



## gibosi

lupoal said:


> my two tungsol 6SN7GTB, are driven by two CV4014 (thank you Datum Walnut!) and... they sound really fine but... the two tubes seems to have (well, I think they have) a quite different operating temperature, I swipped the tubes between the two position and the hotter one is always the same (tube, not position), I've done the same with the CV4014 (thinking could be from differences in those but no, the hotter 6SN7 remain unchanged)...here is a picture, what do you think about? all normal or one of the tubes is fault?



How do you know that they have quite different operating temperatures? Have you measured the temperature? Or is it that one is brighter than the other?


----------



## Datun Walnut

Sorry, I was in the pub . I'd say that sounds ok to me too


----------



## cddc

lupoal said:


> ... so here...
> 
> 
> between 7 and 8... so, looking at from the bottom to the valve the first two pins moving in counterclowise direction... right?
> unfortunately no way to measure each heater inside as they are in parallel on noly two pins (and two resistors in parallel... well the gap in the values could be higher then evaluated via multimeter)




Look at the tube from the bottom (as in the pic above), you should count pins clockwise (instead of countclockwise).

I guess you measured wrong pins, and that's why you got zero reading.


----------



## cddc

lupoal said:


> in the mean time I've measured the voltage at the heater... it is roughly 6,7Vac (the voltage at home is 240Vac instead of the nominal 220Vac)
> I've tried also to get the value of resistance between pin 7 and 8 but no way... I always get 0... tested both Tungsl and both Sylvania... always 0 but there is electrical continuity as testing for that I get a nice "beeeep" from multimeter




The tube on the right does look much brighter than the one on the left.

You can measure the temp with a laser gun or some DMM with temp function. 

But I think measuring the heater resistance should be much easier. You can find if there is any short or problem which could possibly lead to the difference in resistance or brightness. 

The 2 filaments inside 6SN7 are indeed wired in parallel, so it's impossible to measure only one of them, you can only measure the overall combined resistance.


----------



## cddc (Oct 18, 2020)

lupoal said:


> Datun... please read two messages above... I've measured the voltage and is 6,7Vac... no way for the heater impedance, between 7 and 8 always 0




Also, make sure when you measure the resistance you need to unplug the tubes, and then measure them. You can not measure the resistance when they are still sitting in the sockets.


Edit: also make sure your DMM is set on the right range (e.g. 20 ohms). I have measured 6SN7 filaments before, it's somewhere between 1 to 3 ohms, I think. If you set your DMM on the 20K or 2M ohms range or on the continuity range, you will definitely get a zero reading.


----------



## TrollDragon

cddc said:


> I guess you measured wrong pins, and that's why you got zero reading.


No combination of pins would give him 0 ohms unless the tube was shorted. I think the scale was too high on the meter.


----------



## cddc (Oct 18, 2020)

TrollDragon said:


> No combination of pins would give him 0 ohms unless the tube was shorted. I think the scale was too high on the meter.



lupoal was asking if he should count the pins countclockwise, so I was telling him that this is the wrong way of counting and getting the wrong pins is a possibility if using the wrong way.

Now, how to display an open circuit on different multimeters would be tricky. Some may show OP and lupoal thought it's a zero with a suffix P, this could be a possibility; or some may show the infinity sign which looks like 2 zeros, this is also a possibility; or some just use 0 to show open circuit, it is also a possibility.

We can't conclude anything from what lupoal told us. So we can only give him the possible reasons.


----------



## cddc

Anyway, I've told lupoal all the possibilities. It is not rocket science, I think he should be smart enough to figure it out.


----------



## lupoal

gibosi said:


> How do you know that they have quite different operating temperatures? Have you measured the temperature? Or is it that one is brighter than the other?



just because it looks brighter (as you can see in teh picture)... well, to be nore precise, one is orange (hot) the onther tube is almost grey/metal that should means much colder


----------



## lupoal

cddc said:


> Look at the tube from the bottom (as in the pic above), you should count pins clockwise (instead of countclockwise).



that what I've done... counterclockwise

when you "touch" with the miltimeter all the other pins there is no connection between them, the only two pemanentluìy connected are  those to the heater... I have the doubt they measure 0 because it just a wire, better to say two wires in parallel, so almost no resistance... very close to look like a short-circuit


----------



## lupoal

TrollDragon said:


> No combination of pins would give him 0 ohms unless the tube was shorted. I think the scale was too high on the meter.



I tried switching the multimeter between 2 - 20 - 2k - 2M - 20M... in all the case I got 0... and I got 0 measuring a couple of Sylvenia too, it can't be possible I have all 4 different tube shorted... I'm doing something wrong and/or there is something I don't understand

today I will measure the current consumption, only heaters, on all the four tubes... let see if I get more useful values


----------



## cddc

lupoal said:


> that what I've done... counterclockwise
> 
> when you "touch" with the miltimeter all the other pins there is no connection between them, the only two pemanentluìy connected are  those to the heater... I have the doubt they measure 0 because it just a wire, better to say two wires in parallel, so almost no resistance... very close to look like a short-circuit



The heater pins are easy to find...as you said only 2 pins in 6SN7 will beep.

But heater is not like a short, if it's like a short, the fuse in your amp would have been blown.

The heaters are 2 pieces of short tungsten wires, just like the ones in old light bulbs, so there is some resistance value. I have measured 6SN7 heaters before, it's somewhere between ohms 1 and 3 ohms.

I am now thinking you possibly did not set up your multimeter correctly, or your multimeter has problems.


----------



## cddc

You can measure the current consumption too, but it will be more difficult.


----------



## lupoal

cddc said:


> .... I was telling him that this is the wrong way of counting and getting the wrong pins is a possibility if using the wrong way.



form the tube datasheet ...




and here is how I counted them


----------



## lupoal (Oct 19, 2020)

thanks cddc,
hope is not my multimeter... anyway the info about probable resistance value between 1 to 2 ohms is very useful, I'll try again

I can't find in the tube data sheet the nominal value of heater current consumption (here) ... what could be a correct value?


----------



## cddc

lupoal said:


> form the tube datasheet ...
> 
> and here is how I counted them




That's right, we call this clockwise, and you call it counterclockwise?


----------



## lupoal

well ... I meant moving counteclowise from the key... not about the pin value... ... just a misunderstanding (we call it in the same way also here in Italy)

anyway... I can't find in the tube data sheet the nominal value of heater current consumption (here) ... what could be a correct value?


----------



## cddc

LOL...okay then, it's the same thing as long as you can locate them


----------



## lupoal (Oct 19, 2020)

ok, yesterday was the wrong day as today I've done again the resistance measure and both the Tungsol give me a value of 1,7 - 1,8 Ohm... I've measured three times and the value is repeteable


----------



## TrollDragon

lupoal said:


> I can't find in the tube data sheet the nominal value of heater current consumption (here) ... what could be a correct value?


The second page shows the typical heater current draw of 0.6A


----------



## gibosi

lupoal said:


> just because it looks brighter (as you can see in teh picture)... well, to be nore precise, one is orange (hot) the onther tube is almost grey/metal that should means much colder



It is important to remember that these tubes were handmade, and therefore, inevitably, there are small construction differences when comparing one tube to another, some visible to the naked eye and some hidden. And thus, it is not at all uncommon that one tube appears to be brighter than the next and typically this difference in brightness is of no real consequence.

>  my two tungsol 6SN7GTB, are driven by two CV4014 (thank you Datum Walnut!) and... they sound really fine but...

Since they sound "really fine" I suggest that you relax and enjoy them. On the other hand, you are learning how to make meaningful measurements and this is a good thing.


----------



## lupoal

... yes.. I have to relax

in the mean time I was surfing ebay, with picclick, for some other 6SN7 and... wow, in USA there is a huge offer of those tubes and some of them really interesting ... I mean quality (hopefully) and good price... unfortunately shipment cost and customs cost push USA suppliers too far from me... here there is much less choise and they are much more expensive (average the double)


----------



## gibosi

lupoal said:


> ... yes.. I have to relax
> 
> in the mean time I was surfing ebay, with picclick, for some other 6SN7 and... wow, in USA there is a huge offer of those tubes and some of them really interesting ... I mean quality (hopefully) and good price... unfortunately shipment cost and customs cost push USA suppliers too far from me... here there is much less choise and they are much more expensive (average the double)



Since it appears that you live in Italy, perhaps Fivre 6SN7GT are relatively easy to find and not too expensive? To my ears, they are excellent.


----------



## mab1376

its definitely possible there's some corrosion on the heater pins or the heater itself. more resistance equals more heat.


----------



## lupoal

pin are perfect, I’ve cleaned and treated them with Deoxid Gold... about the heater I can’t say anything but at the multimeter they measure identical


----------



## lupoal

gibosi said:


> Since it appears that you live in Italy, perhaps Fivre 6SN7GT are relatively easy to find and not too expensive? To my ears, they are excellent.



yes, I live in Italy, Milan

what about the Russian tubes OTK? Do they sound terrible? they are really cheap
Fivre... well there are some from 30 euro up to more then 200 euro... and not so many

so all 6SN7... 6SN7GT / GTA / GTB are compatible with Little Dot MK2? No risk about overload because of inrush current? ( not with GTB obviously)


----------



## gibosi

lupoal said:


> yes, I live in Italy, Milan
> 
> what about the Russian tubes OTK? Do they sound terrible? they are really cheap
> Fivre... well there are some from 30 euro up to more then 200 euro... and not so many
> ...



I quite like the Russian Melz and Foton 6N8S. My advice is to go for 1950's production, if you can. 

The 6SN7GTA and GTB were introduced to handle larger television screens, but the LD doesn't take adantage of the increased voltage and power ratings. One might say that the LD runs them very gently, so you can use any of them in the LD. However, in my opinion, when used in audio, the GT usually sounds better than the GTA and GTB, but not always. For example, a number of folks think the Westinghouse 6SN7GTB from the mid-1950's is a very fine tube.


----------



## Ric4001 (Oct 19, 2020)

What converter are people using to put 6SN7 tubes in the LD mk2?  I looked at the various pictures posted in this thread, but can't see the full converter name and the links posted are to ebay sales that are no longer available.


----------



## gibosi

Ric4001 said:


> What converter are people using to put 6SN7 tubes in the LD mk2?  I looked at the various pictures posted in this thread, but can't see the full converter name and the links posted are to ebay sales that are no longer available.



On top is an 8-pin 6SN7 socket and on the bottom, a 9-pin 6CG7 and 6FQ7 base. The 6CG7 and 6FQ7 have the same pinout as the stock 6Н6П so this adapter works perfectly.

For example:

https://www.ebay.com/itm/1PC-6SN7-C...-Socket-Adapter-Socket-Converter/233593598968


----------



## lupoal

Ric4001 said:


> What converter are people using to put 6SN7 tubes in the LD mk2?  I looked at the various pictures posted in this thread, but can't see the full converter name and the links posted are to ebay sales that are no longer available.



that is what I'm using now


----------



## lupoal

gibosi said:


> I quite like the Russian Melz and Foton 6N8S. My advice is to go for 1950's production, if you can.



done!
10pcs Foton from 1950's are on the road to me... 39$ for tubes (total) and 32$ for shipment... absolutely crazy


----------



## Arro

The 5670 to ECC88 socket adaptor arrived along with a few of the tubes I ordered. I can confirm that using a pair of Western Electric 396As as output tubes works perfectly with higher impedance headphones. HD650s, 600 ohm DT880s and 600 ohm K240s all sounded good. The Shanghai 6N3 also works without any problems. It's the best sounding Chinese tube I've heard so far. Now I just need to wait for the 6N3Ps and the 6N26P.



gibosi said:


> While it is certainly safe, with the heater drawing only 0.6amps, I suspect that it will be somewhat under-powered as an output tube, similar to a 6SN7GT.


I thought that might be the case. I always use higher impedance headphones with the MKIV and I haven't run into any issues while using 6SN7 tubes.



MIKELAP said:


> I use these tubes (6N26P)with my WA22 with  5670 to 6SN7 adapters its a very nice sounding tube can also use 5670,6N3P,396A ,according to my notes


The 6N3P would have been my next question so thank you for answering that.


----------



## MIKELAP

Arro said:


> The 5670 to ECC88 socket adaptor arrived along with a few of the tubes I ordered. I can confirm that using a pair of Western Electric 396As as output tubes works perfectly with higher impedance headphones. HD650s, 600 ohm DT880s and 600 ohm K240s all sounded good. The Shanghai 6N3 also works without any problems. It's the best sounding Chinese tube I've heard so far. Now I just need to wait for the 6N3Ps and the 6N26P.
> 
> 
> I thought that might be the case. I always use higher impedance headphones with the MKIV and I haven't run into any issues while using 6SN7 tubes.
> ...


I  have a pair of Reflektor 6N3P-DR tubes should try them its been a while


----------



## CADCAM

Quick question for the experienced MKIII tube rollers here~I have a MKIII with Tung-Sol 6AK5 drivers and 6H6n power tubes.
It sounds great especially since I installed the Tung-Sol driver tubes so my question is how much more does the amp have to give?
If I move on and try different tubes is the time and $$ worth it or am I close to the top of what this amp has to offer.


----------



## triod750

I have LD MKIVSE so I cannot compare directly (have listened to MKIII for a while though) but in my opinion you have just started. With use of adapters for other tubes there is a lot more ahead of you. I use C3g as input and 6N12S as output right now and that is very good but there are other alternatives. It all depends on your preference. And a lot of other aspects.


----------



## Arro

MIKELAP said:


> I have a pair of Reflektor 6N3P-DR tubes should try them its been a while


The Russian tubes I've tried have been some of favourite tubes, so I'm looking forward to see how these sound. I've ordered some different variations of the 6N3P from the Reflector and Oktyabr factories.



CADCAM said:


> Quick question for the experienced MKIII tube rollers here~I have a MKIII with Tung-Sol 6AK5 drivers and 6H6n power tubes.
> It sounds great especially since I installed the Tung-Sol driver tubes so my question is how much more does the amp have to give?
> If I move on and try different tubes is the time and $$ worth it or am I close to the top of what this amp has to offer.


The best bang for your buck tubes without adaptors are probably going to be the 6N6P-IR as output tubes and EF91/EF92 as driver tubes. I've collected over 200 tubes and the best sounding pair of driver tubes that I've found has been some CV138s that I bought for £2 each. Using adaptors will open up your options to C3g driver tubes and 6SN7 output tubes but this is where it can start to get expensive. I use Telefunken C3g driver tubes with Raytheon 6SN7GTB output tubes and it definitely provides a noticeable upgrade.


----------



## Ultrainferno

Ultrainferno said:


> No mentions here at all on Head-Fi about the LD H1, using two 6SN7. I'm thinking of getting one, but to run with the PSVANE CV181-TII.
> Has anyone heard this amp anywhere?



3 months later and the LD H1 has been reviewed. I dedicated a small part to the 6SN7/6SL7GT/CV181-TII. I'm still surprised no one is talking about this amp. Could it be purely because of the looks and price? Because sound-wise it's actually very nice.


----------



## mikeypas

mikeypas said:


> Took a long time to get everything from ebay, but finally got the setup i"m very happy with. Thanks to everyone for guidance and help!
> 6SN7GT VT-231 JAN Sylvania and C3G Siemens
> Adapters and socket savers as I did not remove the gold rings.
> Sounding great!



I wanted to post a quick follow-up after getting my new setup with the mkiii
I am hearing a low level hum, it is not super intrusive, but noticeably present.
Doesn't really change with volume control

Now since I have 6sn7gt , 6sn7gt converter, 9 pin socket saver and c3g, c3g converter, 7 pin socket saver
I thought it would be difficult to track down the noise, however, when I removed the c3g and placed my voshkod , dead silence. I then tried the voshkod with the 7pin saver, and still dead silence.
Therefore it must either be the c3g tubes themselves, or the c3g converter. However, I am unable to do any further testing because I don't have other tubes or other converters to try. 

If I gently try to reposition the tubes, sometimes it feels like the hum is diminished, but then seems to come back after I am done fiddling. 
I tried cleaning as much of the pins with some 99% isopropyl, but hasn't helped.

Any suggestions? Thanks in advance


----------



## gibosi

mikeypas said:


> I wanted to post a quick follow-up after getting my new setup with the mkiii
> I am hearing a low level hum, it is not super intrusive, but noticeably present.
> Doesn't really change with volume control
> 
> ...



I suspect there is a good chance that it is the C3g. A C3g, strapped as a triode, has an amplification factor (AF) of around 40, which is fairly high for a driver in an OTL. And higher AF usually equates to more noise. None of the datasheets I have seen for the 6AK5 show an AF so I don't know what it might be, but I would guess that it is less than 40. So it just might be that if you want to use the C3g in the LD, you have to be willing to tolerate a little more noise.


----------



## mikeypas

gibosi said:


> I suspect there is a good chance that it is the C3g. A C3g, strapped as a triode, has an amplification factor (AF) of around 40, which is fairly high for a driver in an OTL. And higher AF usually equates to more noise. None of the datasheets I have seen for the 6AK5 show an AF so I don't know what it might be, but I would guess that it is less than 40. So it just might be that if you want to use the C3g in the LD, you have to be willing to tolerate a little more noise.



Thank you for the response and explanation. Definitely something I could live with, just thought if there was anything else I could do..
Cheers!


----------



## TrollDragon

mikeypas said:


> I wanted to post a quick follow-up after getting my new setup with the mkiii
> I am hearing a low level hum, it is not super intrusive, but noticeably present.
> Doesn't really change with volume control
> 
> ...


What do you have the gain set at on the amp? Try moving the switches to a lower gain and see if that solves the problem.


----------



## mikeypas

TrollDragon said:


> What do you have the gain set at on the amp? Try moving the switches to a lower gain and see if that solves the problem.



I'm a bit embarrassed of not having thought of that. I had it set to maximum gain 10 for 300 impedance (i'm using HD6XX). 
I tried lowering it to Gain 5, but still hum. I then put it to lowest gain (3) for high sensitivity headphones and the hum was gone!
I do need to turn the volume knob slightly higher, but not that much. I'm at halfway and comfortable.

Any downside to using lower gain for the high impedance headphone except for needing to raise the volume a little more? Everything sounds nice to my ears


----------



## TrollDragon

mikeypas said:


> I'm a bit embarrassed of not having thought of that. I had it set to maximum gain 10 for 300 impedance (i'm using HD6XX).
> I tried lowering it to Gain 5, but still hum. I then put it to lowest gain (3) for high sensitivity headphones and the hum was gone!
> I do need to turn the volume knob slightly higher, but not that much. I'm at halfway and comfortable.
> 
> Any downside to using lower gain for the high impedance headphone except for needing to raise the volume a little more? Everything sounds nice to my ears


None what so ever, I run 250 ohm beyers with a gain of 5 and the volume between 11 - 1 depending on the source.
Enjoy the hum free sound!


----------



## TrollDragon

@mikeypas how are you liking the HD6xx on the Little Dot? I heard them through a Monoprice THX 788 DAC/Amp and was not really all that impressed, but never got to try them on my LD.


----------



## mikeypas (Oct 27, 2020)

TrollDragon said:


> @mikeypas how are you liking the HD6xx on the Little Dot? I heard them through a Monoprice THX 788 DAC/Amp and was not really all that impressed, but never got to try them on my LD.



First time I heard the hd650, hated them. But with the LD mk3 and hd6xx - Absolutely love them! With the right tubes , they “sing” !
I have some Hifiman He400i which sound awful on the LD but great with schiit Asgard.

I actually put the gain back to 10 - sounds better in my opinion, I’ll live with a little low level hum


----------



## CADCAM (Oct 28, 2020)

The best bang for your buck tubes without adaptors are probably going to be the 6N6P-IR as output tubes and EF91/EF92 as driver tubes. I've collected over 200 tubes and the best sounding pair of driver tubes that I've found has been some CV138s that I bought for £2 each. Using adaptors will open up your options to C3g driver tubes and 6SN7 output tubes but this is where it can start to get expensive. I use Telefunken C3g driver tubes with Raytheon 6SN7GTB output tubes and it definitely provides a noticeable upgrade.
[/QUOTE]

Arro ~ Are these the tubes you are talking about? They go in the LD MKIII?

https://www.ebay.com/itm/4x-CV138-Vacuum-Pentode-Tubes-Valves-Rohres-EF91-6AM6-Military/254089121239?_trkparms=aid=111001&algo=REC.SEED&ao=1&asc=225086&meid=2d7f07975839485d9b5cf33edec591bf&pid=100675&rk=2&rkt=15&mehot=none&sd=124263104512&itm=254089121239&pmt=1&noa=1&pg=2380057&_trksid=p2380057.c100675.m4236&_trkparms=pageci:d4b23069-1944-11eb-be19-eae775284f39|parentrq:704d08d61750ada58a9e09d0fffeaa76|iid:1

or how about these?

https://www.ebay.com/itm/MULLARD-EF...758426?hash=item3fce38a51a:g:~j8AAOSwrklVKV5V


----------



## Arro

CADCAM said:


> Arro ~ Are these the tubes you are talking about? They go in the LD MKIII?
> 
> https://www.ebay.com/itm/4x-CV138-Vacuum-Pentode-Tubes-Valves-Rohres-EF91-6AM6-Military/254089121239?_trkparms=aid=111001&algo=REC.SEED&ao=1&asc=225086&meid=2d7f07975839485d9b5cf33edec591bf&pid=100675&rk=2&rkt=15&mehot=none&sd=124263104512&itm=254089121239&pmt=1&noa=1&pg=2380057&_trksid=p2380057.c100675.m4236&_trkparms=pageci:d4b23069-1944-11eb-be19-eae775284f39|parentrq:704d08d61750ada58a9e09d0fffeaa76|iid:1
> 
> ...



The top link are the right tubes but there not all from the same factory. Two of them are made by Thorn-AEI in Sunderland, one of them is MOV and I can't make out the factory code of the left most tube. If you want to decode the CV markings a guide can be found here https://www.valvecollector.uk/cv-valves.htm.

I think the Mullard EF91s are over priced. You can get better sounding EF91/6AM6 tubes for less. Langrex in the UK sells a pair of late production Mullard CV4015 for the same money.
https://www.ebay.com/itm/M8161-EF92...49c50:g:iKkAAOSwIWNdeqX5&shqty=1&isGTR=1#shId

An alternative is the 6HM5/6HQ5/6HA5 which is another highly regarded driver tube. These were made in the US so there's plenty of stock available locally and you won't risk getting a surprise customs charge.
NOS Sylvania 6HQ5
https://www.ebay.com/itm/two-NOS-6H...310153?hash=item1ce6ebfec9:g:1ZcAAOSwPjNef5Dm


----------



## CADCAM

Arro said:


> The top link are the right tubes but there not all from the same factory. Two of them are made by Thorn-AEI in Sunderland, one of them is MOV and I can't make out the factory code of the left most tube. If you want to decode the CV markings a guide can be found here https://www.valvecollector.uk/cv-valves.htm.
> 
> I think the Mullard EF91s are over priced. You can get better sounding EF91/6AM6 tubes for less. Langrex in the UK sells a pair of late production Mullard CV4015 for the same money.
> https://www.ebay.com/itm/M8161-EF92...49c50:g:iKkAAOSwIWNdeqX5&shqty=1&isGTR=1#shId
> ...


I believe I had the 6HM5 in the LD and replaced them with the https://www.ebay.com/itm/Pair-Vinta...e=STRK:MEBIDX:IT&_trksid=p2057872.m2749.l2649
Which sounded superior IMO.
Are the Mullard you suggested which are EF92 drop in replacements?

Thanks for the info btw


----------



## triod750 (Oct 29, 2020)

As I recall it, several users have insisted on that the tall tube 6HM5, for instance EI 6HM5, have been the best sounding tubes of that kind. These, EI,  were produced in former Yugoslavia and of very good quality. Very cheap too. Some people held them as 'endgame input tubes' if you want to avoid adapters. Me, I can't say, since that is the only 6HM5 tube I have used. Next tube I used, that bettered 6HM5 with most output tubes, was C3g with adapters.


----------



## CADCAM

That's what I pulled from the LD... tall bottle 6HM5 if I'm remembering correctly... will check when I get home. If that's true then the Tung-Sol 6AK5W I replaced them with sounded better (again IMHO) than my tall 6HM5's.


----------



## triod750

And with some output tubes my Philips 5654 SQ sounded better (than 6HM5 tall bottle). It's all about synergy and personal preference. My main personal preference is that acoustical music shall sound authentic, voices included.


----------



## CADCAM

It was the 6HM5 Yugoslavian tubes I took out of the LD and replaced with the Tung-Sol 6AK5. They were a pretty substantial upgrade as I remember, I fell in love with their detail retrieval and they have been in ever since. I had a pair of 67 Sylvania 5654 in before that but don't remember how much I liked them... if I had to guess not enough.
Those CV138 look tempting...


----------



## triod750

"5654 is the special quality version of 6AK5". See http://www.r-type.org/exhib/aaq0062.htm That doesn't mean that you will like them. Or that I will. Different combinations give different outcome. Of what I have tried so far, the detail retrieval of C3g with Melz 6H8C and Melz 6H12C (6N8S, 6N12S) is unsurpassed. Siemens C3g with Melz 6H8C might even be a bit too much. They match 6H12C/6N12S better. When I have other adapters I will explore different drivers. The journey may never end. Or maybe it will. I enjoy the ride.


----------



## Arro

CADCAM said:


> I believe I had the 6HM5 in the LD and replaced them with the https://www.ebay.com/itm/Pair-Vintage-TUNG-SOL-6AK5W-JTL-Black-Plate-Hipped-Sq-Getter-Tubes-Tested-2/333575114735?ssPageName=STRK:MEBIDX:IT&_trksid=p2057872.m2749.l2649
> Which sounded superior IMO.
> Are the Mullard you suggested which are EF92 drop in replacements?
> 
> Thanks for the info btw



With the Ei tall envelope 6HM5 I found that the treble on them was excellent. Clear, defined and resolute is how I would describe it. Their fault for me was that they were slightly boomy and felt lacking in the lower mids. If that was also your issue with them then a pair of M8161/CV4015 or a pair of CV138s would be the better option as I find a good EF91/EF92 tube to be more balanced. To me the Mullard M8161 has a very smooth natural presentation that sounds great with any genre. These were my favourite driver tube before I found the Thorn-AEI CV138 and tried the C3g. I still enjoy pairing them with Mullard ECC88 output tubes. The CV138s are more clear and less smooth in the treble which I prefer with classical music.

Link for Mullard CV4015
https://www.ebay.com/itm/M8161-EF92...381072?hash=item4844c49c50:g:iKkAAOSwIWNdeqX5
These are special quality EF92 tubes and require the EF92 jumper setting.


----------



## CADCAM

Anyone rolled the Tung-Sol 6AK5 in the MKIII? Now that I've been listening to it it's fantastic! BTW I'm using the Novosibirsk 6H6P power tubes.


----------



## dany9107 (Nov 3, 2020)

Hi guys, this thread helped me a lot in choosing my tubes for the Little Dot Mk3, I chose the Voskhod and the Mullard 8100. I wanted to ask you now if I want to replace the power cable with a better quality one what should I buy?  Possibly from Amazon or Ebay.


----------



## TrollDragon

dany9107 said:


> Hi guys, this thread helped me a lot in choosing my tubes for the Little Dot Mk3, I chose the Voskhod and the Mullard 8100. I wanted to ask you now if I want to replace the power cable with a better quality one what should I buy?  Possibly from Amazon or Ebay.


Personally I'm not a believer in power cables, but people swear that the Pangea AC-9SE improves their audio..
https://www.pangeaaudio.com/Pangea-Audio-AC-9SEMKII-Power-Cable


----------



## gibosi

dany9107 said:


> Hi guys, this thread helped me a lot in choosing my tubes for the Little Dot Mk3, I chose the Voskhod and the Mullard 8100. I wanted to ask you now if I want to replace the power cable with a better quality one what should I buy?  Possibly from Amazon or Ebay.



Likewise, I am not a believer in exotic power cables. But it seemed to me that perhaps hospital grade power cables might be better than stock and they are relatively inexpensive. That said, I can't hear any difference. lol 

https://www.ebay.com/itm/Hospital-G...3-AWG-Clear-Blue-Gray-Power-Cord/391528221285


----------



## dany9107

Thank you very much for the suggestions, I would like something less exotic and the second cable seems to be more suitable also in terms of price.  I change the cable also because the one supplied is quite short 80cm if I'm not mistaken, I would need 2m. I had seen cables from AliExpress as well but I didn't trust their quality very much, even though I don't think there anyway.  want to be better than the cable provided. I also wanted to ask you if you could put some cables with the Italian socket, so as not to have to use an adapter.  Thanks.


----------



## gibosi (Nov 4, 2020)

dany9107 said:


> Thank you very much for the suggestions, I would like something less exotic and the second cable seems to be more suitable also in terms of price.  I change the cable also because the one supplied is quite short 80cm if I'm not mistaken, I would need 2m. I had seen cables from AliExpress as well but I didn't trust their quality very much, even though I don't think there anyway.  want to be better than the cable provided. I also wanted to ask you if you could put some cables with the Italian socket, so as not to have to use an adapter.  Thanks.



In order to find a cable that can be used in Italian sockets, I suggest that you go to eBay's Italian site and search there for hospital power cables:

https://www.ebay.it/

And you might want to send a message to the vendor asking if they have power cords that can be used in Italy without an adapter.

Good luck!


----------



## dany9107 (Nov 4, 2020)

gibosi said:


> In order to find a cable that can be used in Italian sockets, I suggest that you go to eBay's Italian site and search there for hospital power cables:
> 
> https://www.ebay.it/
> 
> ...




I will do as you told me, meanwhile wandering around on Amazon I came across this cable, could the one you recommend be fine or better?
https://www.amazon.it/dp/B08LG1TDXR/ref=cm_sw_r_cp_api_i_SJUOFbZXKQ74Q


----------



## gibosi

dany9107 said:


> [QUOTE = "gibosi, post: 15956922, membro: 345424"]
> Per trovare un cavo che possa essere utilizzato nelle prese italiane, ti consiglio di andare sul sito italiano di eBay e cercare lì i cavi elettrici ospedalieri:
> 
> https://www.ebay.it/
> ...



Farò come mi hai detto, intanto girovagando su Amazon mi sono imbattuto in questo cavo, potrebbe andar bene quello da te consigliato o migliore?
https://www.amazon.it/dp/B08LG1TDXR/ref=cm_sw_r_cp_api_i_SJUOFbZXKQ74Q
[/QUOTE]

That Amazon power cord looks very nice and the price seems reasonable to me.


----------



## dany9107 (Nov 4, 2020)

gibosi said:


> Farò come mi hai detto, intanto girovagando su Amazon mi sono imbattuto in questo cavo, potrebbe andar bene quello da te consigliato o migliore?
> https://www.amazon.it/dp/B08LG1TDXR/ref=cm_sw_r_cp_api_i_SJUOFbZXKQ74Q



That Amazon power cord looks very nice and the price seems reasonable to me. 
[/QUOTE]
Good, as specs it is fine for my Little Dot Mk3? On the cable I found in the package I read 10A 250V.


----------



## lupoal

5A-152M ... is there anybody that tryied it instead of C3g?
application field is the same and same is the value of Uf=6,3V and similar is If=0,47A ... pin out? I still have to check but looks the same
... and costs very few bucks


----------



## Seriosha

Hello, I need a little help. Want to change the volume pot in my Little dot MKIII but I can't get it out, don't want to break anything but I don't know what to do after unscrewing the front panel, the pot seems fit in place by two little brackets, how to get it out without breaking anything?
By the way the pot in mine read 323G 50KAX2, so I was thinking about an Alps blue velvet 50K, right? Thanks in advance.


----------



## MIKELAP

Seriosha said:


> Hello, I need a little help. Want to change the volume pot in my Little dot MKIII but I can't get it out, don't want to break anything but I don't know what to do after unscrewing the front panel, the pot seems fit in place by two little brackets, how to get it out without breaking anything?
> By the way the pot in mine read 323G 50KAX2, so I was thinking about an Alps blue velvet 50K, right? Thanks in advance.


Use search function you will find what you are looking for and Alps pot is 100kA  X 2   check page  611 post  9163


----------



## TrollDragon

lupoal said:


> 5A-152M ... is there anybody that tryied it instead of C3g?
> application field is the same and same is the value of Uf=6,3V and similar is If=0,47A ... pin out? I still have to check but looks the same
> ... and costs very few bucks


The Little Dot shares a 1A filament current with both driver tubes and those 5A-152M are getting very close to pushing that limit at 0.47A each. Don't forget tubes can briefly draw up to three times the listed filament current during startup.


----------



## Seriosha

Thanks, but I need not that, I'd like to know how to dismount the original one from the face plate without problems. Anyone that has done that already can give me some tips?


----------



## TrollDragon

Seriosha said:


> Thanks, but I need not that, I'd like to know how to dismount the original one from the face plate without problems. Anyone that has done that already can give me some tips?


There should be a retaining nut or screws behind the volume knob.


----------



## MIKELAP

Seriosha said:


> Hello, I need a little help. Want to change the volume pot in my Little dot MKIII but I can't get it out, don't want to break anything but I don't know what to do after unscrewing the front panel, the pot seems fit in place by two little brackets, how to get it out without breaking anything?
> By the way the pot in mine read 323G 50KAX2, so I was thinking about an Alps blue velvet 50K, right? Thanks in advance.


Did you unplug it ?


----------



## gibosi

lupoal said:


> 5A-152M ... is there anybody that tryied it instead of C3g?
> application field is the same and same is the value of Uf=6,3V and similar is If=0,47A ... pin out? I still have to check but looks the same
> ... and costs very few bucks



As TrollDragon points out, the filament current is higher than the C3g, and might be too much for the LD to handle. And further, even if you were willing to accept the risk, the pin-outs of these two tubes are different, and thus you would need another different adapter.


----------



## Seriosha

TrollDragon said:


> There should be a retaining nut or screws behind the volume knob.


Yeah, I unscrewed that...but the pot doesn't come off...tried to but after some force applied was scared to break something and gave up.


----------



## MIKELAP

Seriosha said:


> Yeah, I unscrewed that...but the pot doesn't come off...tried to but after some force applied was scared to break something and gave up.


             A picture would help


----------



## lupoal

thks to everybody for reply and help


----------



## lupoal

... ok now pls excuse me for the stupid question of the day but... about C3g I can read inside quite reliable site here in Europe: " They show their extreme low distortion only as pentodes. They can be used triode connected, but then gain comes down a lot, and the distortion increases to a level just below triodes like 6SN7." ... so as I'm a true rookie... is the C3g in LD2 used as triode or as pentode?

then... available are... TFK... Siemens... Lorenz ITT.... Valvo ... TFK are crazy expensive, roughly the double then the others... what is the scale in terms of sound quality?


----------



## gibosi

lupoal said:


> ... ok now pls excuse me for the stupid question of the day but... about C3g I can read inside quite reliable site here in Europe: " They show their extreme low distortion only as pentodes. They can be used triode connected, but then gain comes down a lot, and the distortion increases to a level just below triodes like 6SN7." ... so as I'm a true rookie... is the C3g in LD2 used as triode or as pentode?
> 
> then... available are... TFK... Siemens... Lorenz ITT.... Valvo ... TFK are crazy expensive, roughly the double then the others... what is the scale in terms of sound quality?



First, Valvo never manufactured the C3g. Only Lorenz, Telefunken and Siemens manufactured this tube.

Second, if the C3g has a shiny black can it was manufactured by Siemens, regardless of the branding.

And third, the only way to know for sure that you have a Telefunken or Lorenz is 1) the cans are flat black, that is, no shine. And two, the maker's logo and text is embossed into the top.

Both of these are Siemens. The newer ones have shiny black cans and white stenciling. The older ones have flat black cans with embossed tops.





Again, note the flat black cans and embossed tops




So again, all C3g with shiny black cans were made by Siemens regardless of the branding. So don't pay a premium for a shiny-black "Telefunken."


----------



## TrollDragon

lupoal said:


> They show their extreme low distortion only as pentodes. They can be used triode connected, but then gain comes down a lot, and the distortion increases to a level just below triodes like 6SN7." ... so as I'm a true rookie... is the C3g in LD2 used as triode or as pentode?


All pentodes are strapped as triodes internally on the Little Dot circuit board, you cannot run them as pentodes.


----------



## lupoal

... but so if I can’t run them as pentodes ... is the gap in price ( cuouple of tube is about 140 bucks and two adapters are about e5 bucks) compared to 6HM5 jugo justified by much better performance?


----------



## lupoal (Nov 9, 2020)

@gibosi

... in practis you are telling me that all the tube with shiny black surface has been made by Siemens, the brand on them doesn’t matter... and because of that they all sound the same... right?

but... between a shiny Siemens and an matt embossed lLorenz... would should I get ?

I’ve seen mat black Telefunken, not embossed brand, reach crazy price level... double then Siemens ... mah


----------



## gibosi

lupoal said:


> @gibosi
> 
> ... in practis you are telling me that all the tube with shiny black surface has been made by Siemens, the brand on them doesn’t matter... and because of that they all sound the same... right?
> 
> ...



Yes, all C3g with shiny black cans sound the same. They were all made by Siemens.

And in my experience, the flat black Telefunken sounds about the same as the Siemens. I would say that the TFK have a bit more treble presence than the Siemens, but othewise sound very similar. And in my opinion, the difference is so small that the TFK are not worth the extra money.

So now the decision is between flat black Lorenz and shiny Siemens. They sound very different. The Lorenz has more bass presence and generally speaking is darker than the Siemens. So how to decide? Since the Siemen are less money, I suggest that you get a pair. And if you like them, relax and enjoy. But if you discover that you prefer a darker sound, then you can patiently wait for a pair of Lorenz to appear for a decent price.

Good luck!


----------



## lupoal (Nov 10, 2020)

thanks a lot! 

... and/but... what about this question here: " ... but so if I can’t run them as pentodes ... is the gap in price ( cuouple of tube is about 140 bucks and two adapters are about e5 bucks) compared to 6HM5 jugo justified by much better performance? "

this is my last question then I promise I stop  (till my next one that still have to popup in my mind )


----------



## triod750

I use a pair of flat black Siemens C3g and would never go back to yugo 6HM5. To me, the difference is well worth the money. They make my acoustical music much cleaner and more authentic. If I find a Lorenz pair at a decent price I will buy them too. This far, I have mostly been using various 6SN7 with C3g but lately the Melz 6H12C/6N12S has been my preference. They use the same adapter. Melz 6H8C/6N8S is a somewhat lean and very clean Russian version of 6SN7. I am eager to try these with the Lorenz C3g as I expect them to be a very good combination to suit my taste. I have also tried 5687 as output tubes. I like them better than the 6N6P. They are good and powerful but I much prefer 6N12S that are electrically close.

But it is all a matter of preference. And it is fun to experiment.


----------



## lupoal (Nov 10, 2020)

... I placed my order for two lightly used Siemens (90 USD + 10 USD for shipment)... I thought, as Gibosi indicate, the Lorenz be maybe too much bassy for my taste... at least with Sylvania or Marconi (waiting for them from Canada)... I have some doubt about how Siemens will work with Tungsol... the 6H8C (Foton) are really punchy, with powerful bass, and clean, maybe for them Lorentz is better, we will see









now I have to try to solve a problem with the power supply... at my home instead of 230Vac I have 240Vac... that give me at the tube 6,7 instead of 6,3... ok 6,3 +/-5% is 6,7 but this is exactly the operating limit specify in Siemens and Telefunken data sheet, for voltage higher then that (slightly higher?) the expected life is specify less then the 10.000 hours otherwise guarantee... uff


----------



## triod750

lupoal said:


> ... I placed my order for two lightly used Siemens (90 USD + 10 USD for shipment)... I thought, as Gibosi indicate, the Lorenz be maybe too much bassy for my taste... at least with Sylvania or Marconi (waiting for them from Canada)... I have some doubt about how Siemens will work with Tungsol... the 6H8C (Foton) are really punchy, with powerful bass, and clean, maybe for them Lorentz is better, we will see
> 
> 
> 
> ...



I would not worry about the voltage. I have 242 - 245Vac and have been running tubes on that voltage for years with no trouble. All
 you have to do is to restrict your listening to about 24 hours/day, no more  .

Good luck!


----------



## lupoal

thank you 

... changing a little the argument but not the product... I noticed, unfortunaltely only after I placed my order and payed, that the tube on the left has a small damage in the housing, top border close to number "7"... what do you think about? the dealer declared tested tubes with 16mA and 17mA... I've read somewere (don't remember where and about which tube) that a small fall down could cause problems in transconductance but not in the other parameters normally mesured/declared? are those b.s. or there is a truth?


----------



## Arro

I now have the 6N26P and I've been listening to them for a few days. I think that they are well worth trying as power tubes. To me they sound better than the 6H30Pi and the 6N6P-IR.




Their construction seems to be closer to the 6H30Pi than the 6N6P-IR. They have a flat round double braced getter and the spacing of the anodes is further apart.


----------



## gibosi

lupoal said:


> thank you
> 
> ... changing a little the argument but not the product... I noticed, unfortunaltely only after I placed my order and payed, that the tube on the left has a small damage in the housing, top border close to number "7"... what do you think about? the dealer declared tested tubes with 16mA and 17mA... I've read somewere (don't remember where and about which tube) that a small fall down could cause problems in transconductance but not in the other parameters normally mesured/declared? are those b.s. or there is a truth?



In my experience, vacuum tubes are not nearly as fragile and delicate as people often think, and a few scratches and dents in the black metal cans of a C3g should not be a problem. When you finally get them, your ears will be able to tell you if they are good or not.


----------



## lupoal

thank you


----------



## CADCAM

OK so I rolled the Tung-Sol 6AK5 into my LD MKIII and have been listening for a while now...absolutely amazing! It's a Maverick Audio D2 DAC & Beyer DT990 600ohm system and the LD never sounded this good. 
So clean and detailed, it's amazing to me that swapping out the driver tubes makes this much difference. My gain is set at 5 and the volume is right at 9:00 with the 990's. 
Acoustic Alchemy is drifting into my mind like smoke in an old jazz club. Good Lord this is good! This is what this hobby is all about...


----------



## CADCAM

I'm still thinking about how freakin' good Acoustic Alchemy sounded last night on the LD with those Tung-Sol's...
I'll have to try some different material and see\hear if everything sounds that good...


----------



## lupoal

C3o vs. C3g ... is there any difference in sound? 
specs of C3o declare is like a C3m but at 6,3V... and C3m should be the older version of C3g... so... ?


----------



## triod750

CADCAM said:


> I'm still thinking about how freakin' good Acoustic Alchemy sounded last night on the LD with those Tung-Sol's...
> I'll have to try some different material and see\hear if everything sounds that good...



I often find that different tubes suits different music or different recordings better. Let us know of your findings. I haven't tried T-S 6AK5.


----------



## gibosi

lupoal said:


> C3o vs. C3g ... is there any difference in sound?
> specs of C3o declare is like a C3m but at 6,3V... and C3m should be the older version of C3g... so... ?



The C3o and C3g have different pinouts, so it would be necessary to obtain yet another different adapter. My thinking was that it was likely not worth the extra money and hassle, so I have no experience with the C3o and can't say how it compares to the C3g.

I suggest that you get a  pair and let us know?


----------



## lupoal

gibosi said:


> I suggest that you get a  pair and let us know?



... thank you ... and no thank you


----------



## Arro

I was thinking about other potential tubes that could be used for the Little Dot and I wondered if anyone had considered octal pentodes as driver tubes?
The 6SJ7, 6SG7 and 6SH7 all have a heater current of 0.3 and adaptors exist for them to be used in place of a 6AK5.


----------



## TrollDragon

Arro said:


> I was thinking about other potential tubes that could be used for the Little Dot and I wondered if anyone had considered octal pentodes as driver tubes?
> The 6SJ7, 6SG7 and 6SH7 all have a heater current of 0.3 and adaptors exist for them to be used in place of a 6AK5.


I don't think we ever tried them since they are metal can tubes and you don't get to see that awesome glow.


----------



## Seriosha

MIKELAP said:


> A picture would help


Sorry for late reply, here some pics to the point I stopped. The little screw inside the pot is removed but still the metal pot does not come out. What to do now?


----------



## TrollDragon

Seriosha said:


> Sorry for late reply, here some pics to the point I stopped. The little screw inside the pot is removed but still the metal pot does not come out. What to do now?


You have to remove the volume knob and unscrew the pot from the front plate.
The pot will also unplug from the board via the white connector on the end of the wire.


----------



## Arro

Seriosha said:


> Sorry for late reply, here some pics to the point I stopped. The little screw inside the pot is removed but still the metal pot does not come out. What to do now?



Turn the volume knob down to zero. You should see a hole. Inside is a screw. Loosen the screw and you will be able to slide the knob off the shaft.


----------



## MIKELAP (Nov 20, 2020)

Seriosha said:


> Sorry for late reply, here some pics to the point I stopped. The little screw inside the pot is removed but still the metal pot does not come out. What to do now?


  Loosen the scew for the knob ,remove knob you will see this hex nut this is what is preventing you from removing the pot disconnect plug and remove it .be extra careful with the pot wires they are very fragile


----------



## lupoal (Nov 23, 2020)

Does anyone have experience with these Brimar 6064/EF91 on an LD2?


----------



## Whelkie D

lupoal said:


> Does anyone have experience with these Brimar 6064/EF91 on an LD2?


I just bought some. They sound pretty good, but did notice the bass can be "slack" as mentioned in the review on page 1 of this thread. I did find the detail pretty good though. Would definitely recommend trying them if you can find them at a decent price.


----------



## lupoal

thank you 
I forgot there was a review about that in the first page, well I already have the a couple of CV4014 (and two couples recently bought as backup)... so having already the EF91 that seems to be one of the best options I think I will put my money in something different... I will look for Mullard CV401


----------



## Whelkie D

lupoal said:


> thank you
> I forgot there was a review about that in the first page, well I already have the a couple of CV4014 (and two couples recently bought as backup)... so having already the EF91 that seems to be one of the best options I think I will put my money in something different... I will look for Mullard CV401


I also got some Brimar EF92. They sound much more "rounded" than the EF91s so if you manage to find some, I would also recommend those.


----------



## lupoal

in the mean time, few minutes ago, I've received the two C3g Siemens (lightly used.. hopefully) I've ordered two weeks ago (adatpters from China are at custom office here i Italy now.. so few day I hope) ... because of the shape they have I can't use the small cup supplied with Deoxid Gold to clean the pins... how do C3g owners proceed in this case? suggestions and/or tricks?


----------



## lupoal

Whelkie D said:


> I also got some Brimar EF92. They sound much more "rounded" than the EF91s so if you manage to find some, I would also recommend those.



thank you  ... I will look for those too


----------



## lupoal

so, the two C3g... one is perfect (at least looks perfect... I still have to turn it ON), the other one... here are some pictures, what do you think about?


----------



## MIKELAP

lupoal said:


> in the mean time, few minutes ago, I've received the two C3g Siemens (lightly used.. hopefully) I've ordered two weeks ago (adatpters from China are at custom office here i Italy now.. so few day I hope) ... because of the shape they have I can't use the small cup supplied with Deoxid Gold to clean the pins... how do C3g owners proceed in this case? suggestions and/or tricks?


To clean pins i always use a fine grit sandpaper it will remove all the grime .One piece of advice you probably saw this before if you read the thread .Ounce you insert C3G tubes in there adapters i would leave them in there because they are very fragile ,also dont wiggle them when inserting them  and like i said it is best to leave them in


----------



## lupoal

yes I remember your suggestions... I'm little bit scared by that (looks like) deep corrosion, do you think it could has caused serious damage to the pins (mechanical and electrical)? what your experience about? in some point it looks like gold is not there any more


----------



## MIKELAP

lupoal said:


> yes I remember your suggestions... I'm little bit scared by that (looks like) deep corrosion, do you think it could has caused serious damage to the pins (mechanical and electrical)? what your experience about? in some point it looks like gold is not there any more


  Seller tested them ? i would clean the pins should be ok .


----------



## tubebuyer2020 (Nov 24, 2020)

lupoal said:


> ... because of the shape they have I can't use the small cup supplied with Deoxid Gold to clean the pins... how do C3g owners proceed in this case? suggestions and/or tricks?



Can you not use a pen applicator? http://store.caig.com/s.nl/it.A/id.1554/.f

Though you might need the other pen as well: "if the surface looks dirty/oxidized, preclean with DeoxIT D-Series contact cleaner".


----------



## lupoal (Nov 24, 2020)

MIKELAP said:


> Seller tested them ? i would clean the pins should be ok .



well... so he declared... ok, at the beginning I will try with deoxid,it should be able to penetrate deep inside metal metal flakes (if there are any) and better fix/reconstruct (at least that what they declare)

btw... thks


----------



## lupoal (Nov 24, 2020)

tubebuyer2020 said:


> Can you not use a pen applicator? http://store.caig.com/s.nl/it.A/id.1554/.f
> 
> Though you might need the other pen as well: "if the surface looks dirty/oxidized, preclean with DeoxIT D-Series contact cleaner".



some time ago I bought this kit ... I will apply D25 with a little brush, maybe more then one time removing it between the applications, and then at the end protect the pins with Gold GXMD ... normally, with smaller tubes, I left them inside the liquid overnight and then clean and protect but with these C3g I would need a special cup and one liter of liquid (and it is extremely expensive!)

I will put pictures here about results tomorrow


----------



## gibosi

lupoal said:


> some time ago I bought this kit ... I will apply D25 with a little brush, maybe more then one time removing it between the applications, and then at the end protect the pins with Gold GXMD ... normally, with smaller tubes, I left them inside the liquid overnight and then clean and protect but with these C3g I would need a special cup and one liter of liquid (and it is extremely expensive!)
> 
> I will put pictures here about results tomorrow



I would clean them mechanically first, and then use the chemical.


----------



## triod750

Like MIKELAP I've always used fine grit sandpaper since I believe mechanical cleaning is most effective. I think the gold plating of the pins is more of protection for the pins during storage. Sellers like to use it as a reson for higher price. My Siemens C3g don't have golden pins but sound very good. Chemical cleaning might work for the last percent when you have done the first 99 percent of mechanical  cleaning. This is an opinion, not science. As a final measure, I use PRF 6-68 contact cleaner. I apply it to a cotton pin and clean the pins until the next cotton pin is clean.


----------



## TrollDragon

Dremel with a 3mm rubber polishing cone does an excellent job cleaning pins.


----------



## lupoal (Nov 25, 2020)

so, here are the results of my efforts... I left the tubes with chemical overnight, then (as suggested  ) super fine sand paper (very carefully), then four more times chemicals and cleaning in between the applications...





now... the alluminum housing is there as shielding against external electrical noise but, if I'm right, it is not connected to ground when used in LD... is there anybody that tried an external connection to earth?


----------



## gibosi

lupoal said:


> so, here are the results of my efforts... I left the tubes with chemical overnight, then (as suggested  ) super fine sand paper (very carefully), then four more times chemicals and cleaning in between the applications...
> 
> 
> 
> ...



The pins look great! 

I don't remember anyone trying to ground the case in their LD. And since my amp is not operating in an environment with a lot of external noise, I did not consider that extra shielding necessary.


----------



## Whelkie D

lupoal said:


> so, here are the results of my efforts... I left the tubes with chemical overnight, then (as suggested  ) super fine sand paper (very carefully), then four more times chemicals and cleaning in between the applications...
> 
> 
> 
> ...


 Yes, I found that the C3Gs had a hum to them so I connected a thin piece of copper wire from each aluminium case to one of the screws on the front casing of the LD2. Works fine now without the hum. Hope this helps. Oh, and I got a really loud buzzing sound when the LD was on the lowest gain setting which disappeared when I changed the setting. Good luck.


----------



## lupoal

I will try... I recently discovered how sensible is the LD to the quality of the cable used for power supply ( nothing esoteric, just a diy TNT  is enough to make a very big difference... at least in my set up), I will check if anything improve with grounding of C3g


----------



## lupoal

does 6N7 makes any sense instead of 6SN7? 
i‘ve seen from specs the 6N7 heater require 50mA more then 6N6P so could not be a problem for LDII and.adapters 6N7 to 6SN7 are available in eBay...but... does it worth?


----------



## gibosi

lupoal said:


> does 6N7 makes any sense instead of 6SN7?
> i‘ve seen from specs the 6N7 heater require 50mA more then 6N6P so could not be a problem for LDII and.adapters 6N7 to 6SN7 are available in eBay...but... does it worth?



It's hard to say without trying them. The 6N7 has a common cathode shared by both sections whereas, a 6SN7 (and a 6Н30П) has two separate cathodes. So the adapter has to tie that common cathode to two separate cathode connections in the amp. And even though there are 6N7 to 6SN7 adapters, some amps don't like this.

So unless someone who as tried these in the LD chimes in to tell us his/her experience, it is not clear to me that they would be worth it. On the other hand, if you feel like a pioneer, you could try them and tell us!


----------



## TrollDragon

The common cathode with not work in our amps unless you use dual 6N7 wired up as single triodes. 
Converting 4 UX7 sockets to dual B9A adds another level of why?


----------



## triod750

I am a pioneer. An adapter is on its way to me to try 6N7 as input in Little Dot MKIVSE. Will it work? I don't know. Why do I want to try? I am very fond of Melz 6H8C for their transparency and detail but they are somewhat lean with C3g as drivers. It's kind of too much of a good thing. I wanted to try Ken-Rad 6N7 to see if that would give me a synergy that I like.

Quite a few other adapters are joining that one, and an external PSU for heaters that are too hungry for the Dotty transformer.


----------



## lupoal

gibosi said:


> ... if you feel like a pioneer, you could try them and tell us!



... if you are looking for an hero... you are watching in the wrong direction 

anyway, thks... I didn’t notice that “problem” with the cathode... risk escaped


----------



## lupoal (Dec 1, 2020)

... so I've plugged in my two C3g and obtained... a very serious HUMMMMMMM mainly on the left channel ... but a little on the right channel too

here is how i tried to track/fix the problem

- I swappd the two tubes togheter with their adapter... problem unchanged (from now P.U.)
- I left the two adapters in place and swapped only tubes... P.U.
- I left the tubes in place and swapped only the adapters... P.U.
- I reduced the gain inside from 5 to 3... lower UHMMM volume but ... P.U.
- I tried putting to ground the two valve's housing, no result, some additional noises when touching the tubes with the copper wire but... P.U.
- I changed the "power" tubes from 6H8C Foton to 6SN7GTB Tungsol... P.U.
- I tried with unplug-plug all the RCA in-out (no sense but who knows)... P.U.

leaving same configuration as yesterday, 6H8C + EF95 Mullard... dead quiet, no noise at all even with volume at max (without music clearly)

before to use the adapters (china stuff... chinese rubbish... but NOS ceramic socket) I checked both with tester verifying no shorts and correct pin in-out... the adpters has been cleaned as I've done with tubes (same chemicals)... contacts in the adapters don't look very clampy, but the sound, in the backgrond of noise, comes out so the connections should all be there (or not?)

suggestions? helps/tricks/miracles ?


----------



## Whelkie D

lupoal said:


> ... so I've plugged in my two C3g and obtained... a very serious HUMMMMMMM mainly on the left channel ... but a little on the right channel too
> 
> here is how i tried to track/fix the problem
> 
> ...


Try making the gain higher. Just a thought, but it seemed to work with mine, so worth a try. Good luck.


----------



## lupoal

thks 
tomorrow I will try it and will also open the adapters... just to see how high is the Chinese quality inside (and if necessary redo the soldering)


----------



## lupoal

... so it seams that I'm the only one that instead of a magical unicorne bought a angry pitbull... strange... anyway, as said I opened the adapters ad discovered this simply incredible "quality" ... well high quality real rubbish... here are the pictures:





























ok, the name of the dealer in ebay is xulingmrs ... clearly problems could happen even to the best supplier and is correct to give him possibility to recover but, in this case, imho there is nothing to recover... the quality is simply absent at every degree


anyway, I've redone the solderings but nothing changed... the HUMMMM is still there even at gain 10... I'm have the idea the problems could come from couple of factors acting togheter... tollerances in the components inside tha LD (righ e left circuits slightly different) and a little to high power supply at home, here I have roughly 260Vac instead of nominal 230Vac so at the output of LD transformer the voltages are probably 10% higher than nominal and, togheter with components, that cause HUUMMMMMM


----------



## triod750

Strange. My adapters come from Mrs Xu Ling (or is it Ling Xu) and they are completely silent. Bought a few years ago. I'm not sure if they look like that. Is it this item? https://www.ebay.co.uk/itm/1pc-C3G-...219735?hash=item2ee0375ad7:g:ZHcAAOSw9N1VwVKM


----------



## Whelkie D

lupoal said:


> ... so it seams that I'm the only one that instead of a magical unicorne bought a angry pitbull... strange... anyway, as said I opened the adapters ad discovered this simply incredible "quality" ... well high quality real rubbish... here are the pictures:
> 
> 
> 
> ...


That's where I got my adapters from! Perhaps I ought to open mine up and see what they look like inside.


----------



## lupoal (Dec 1, 2020)

I'm using an adapter for 6SN7 to 6N6P too and come from the same supplier... the only differenve is the housing, the second one plastic black with very different housing constuction, instead of the C3gblabla that is metal (in my case not completely shiny but with some spot of corrosion)... anyway, that one for 6SN7 works flowless, I'm not going to open it and check ... I'm quite scared the the inside could be horrible like the other one, I prefer to ignore and hope it is completely different... what is sure is that for C3g is pure rubbish (both pieces I have I mean)

in any case I think the problem is not only from the adapter but, as I wrote, also from C3g tubes that are much more critical then those we use to use with our LD... no problem, in the future I will look less for unicorns, these two now go into a bin and let's move on


----------



## triod750

Very unfortunate experience. I have, from xulingmrs, adapters from C3g to 5654, from 6SN7 to 6CG7/ECC88/6N6P and from 5687 to 6CG7/ECC88/6N6P. They all work flawlessly.


----------



## lupoal (Dec 2, 2020)

no problem, I've spoken with the C3g seller and he decided to refund me the whole amount, shipment charge included (very gentle man)... the adapters are already in the condo bin basket... episode over, let's move on... two 6SN7 RCA should arrive from USA... and two Bad Boy (true or fake? we will see) from Canada


----------



## Arro

The 6SJ7 octal pentodes work in both the I+ and the MK IV. I've been testing it out with a pair of Ken-Rad VT-116 while I wait for more tubes to arrive from America. To fit them in the I+ without modifying the amp I needed to use a pair of Pomona socket tester adaptors. Without this the pins on the 6SJ7 adaptor won't reach far enough into the socket. So far I've tested the VT-116 with 6N6P-IR and MELZ 6N8S as output tubes in the MK IV without problems. The effect on sound is similar to using 6SN7GT driver tubes. The sound just feels bigger and the sound stage is wider. Listening with HD650s it's as though the distance between instruments has been increased. Not bad for tubes that can be picked up for as little as £5 each.


----------



## lupoal (Dec 5, 2020)

- edit -


----------



## lupoal

here inside there are two pages that summarise the info about tubes... the first one is the 77... the second one I can only remember is the 400+ area... I need help, where is the second one? I can’t find it


----------



## triod750

Could it be this? I have saved it as a document.

Posted by Acapella 2014, I think.
___________________________________________________________________________

Hi, Just for Christmas I have put together a table as a reminder for everyone in the thread  and to help new arrivals. The table is now pretty much complete.

Please, let me know if you find any additions or anything that requires correction.

*Little Dot I" / II/ III / IV Endgame Tube Table*



*Power            Tube*
 
 
 
*Name*
*Adapter*
*Heater            Current (A) / 6.3 V*
*Notes*
5687/7044/7119(E182CC)
5687            Powersocket Adapter 
0.9
easily usable            substitutes, sound great
6AS7G/6080
Adapter +            External Power Supply, see 1            and 2            and 3
2.5
this is            probably the icing of the power tube cake
12AU7/12AT7/12AX7/7025/5751/ECC83/6057
Powersocket            Adapter
0.35
 
6BL7/6BX7/6BQ7
Adapter +            External Power Supply, see 1            and 2            and 3
1.5
 
6DJ8
not needed
0.365
 
6GU7/6CG7/6FQ7
not needed
0.6
not            compatible with 12AX7 driver tubes
6N23P
not needed
0.31
 
6SL7*
6SN7            Powersocket Adapter
0.3
lower gain            than 6SN7, not compatible with low impedance cans
6SN7*
6SN7            Powersocket Adapter
0.6
classic high            end tube, not compatible with low impedance cans
6N6P-IR
not needed
0.9
high quality,            long lasting version of the 6N6P-I and considered best sounding            6N6P before the very expensive 6N6P-DR
 
 
 
 
Maximum            recommended heater current for power tubes is 1.0 A. Tubes            exceeding this are highlighted in red.
 
 
 
 
 
 
*Driver            Tube*
 
 
 
*Name*
*Adapter*
*Heater            Current (A) / 6.3 V*
*Notes*
5687/7044/7119(E182CC)
External            driver socket ^, external power supply
0.9
6.3 V / 12.6            V **
6350/6463/ECC813
External            driver socket ^, external power supply
0.9
6.3 V / 12.6            V**
2C51 / 396A /            5670
External            driver socket ^ + driver            socket adapter
0.35
 
7AU7
External            driver socket ^
0.6
3. 5 V / 7            V**
12AU7
External            driver socket ^
0.3
6.3 V / 12.6            V**
12AU7/12AT7/12AX7/7025/5751/ECC83/6057*
External            driver socket ^
0.3
One triode            can be used besides a non-powered one, 6.3 or 12.6 V**
6BQ7A
Adapter
0.4
 
6DJ8
External            driver socket ^
0.365
probably            noisiest double triode, both triodes must be powered
6HM5
none
0.19
probably best            standard AK5-type option
6N23P
none
0.31
 
6SL7*
6SL7            driver adapter
0.3
 
6SN7*
External            driver socket ^, external power supply
0.6
 
C3G(S)* ^^
C3G            AK5 Adapter
0.37
C3G(S) tubes            sound great but they are produced with a fragile glass base. Widen            the socket holes before inserting the tube to avoid breaking.
ECC81
External            driver socket ^
0.3
 
ECC40
External            driver socket ^, external power supply
0.6
 
E80CC/6085
External            driver socket ^, external power supply
0.6 
6.3 V / 12.6            V **
 
 
 
 
Maximum            recommended heater current for driver tubes is 0.4 A. Tubes            exceeding this are highlighted in red.
 
 
 
*: Requires            socket extenders for LD MKIII
": For            Little Dot I only driver tubes.
 
 
9            Pin power socket extender
 
 
 
7            Pin driver socket vector extender
 
 
 
**:            Generally, when doubling the voltage, the apparent current is            halved.
 
 
^:            The external driver socket adaper uses a breadboard and allows the            use of a single double triode to drive both channels.
 
^^ Hypnos1            (post 5670):            How to remove the C3Gs metal shielding, this requires care to            not break the fragile tubes.            


 

 


 
 
 
Power            Tube Requirements (Gibosi post #7937)
 
 
1) Double            triode
 
 
 
2)            Separate cathodes (there are some double triodes such as the E90CC            where the triodes "share" a cathode. These will not            work.)
 
3) Heater            current 1.0A or less
 
 
 
4) 6.3 Volts
 
 
 
 
 
 
 
List            of compatible tubes and 6DJ8, 6SL7, 6SN7, 12AX7 wiring            instructions
 
 




For old school driver tubes operable without adapter, see page 77.

Driver Tube 7-Pin Vector Socket Adapter






Power Tube 9-Pin Socket Adapter


_Revisions 1 & 2, 24/12/2014:_ Thanks for the input Gibosi and Mordy, thanks for sending the socket extender pictures Mordy, which are now included. Added a reference to Hypnos1 on how to remove the C3G(S) metal shielding.
Added ECC40 and E80CC/6085 as suggested by Gibosi, thanks.
Merry Christmas.
Revision 3, 09/01/2015: Added links to the implementation of 6AS7G/6080 power tubes, thanks Gibosi for finding the posts and suggesting the implementation and Mordy making it work. Added link to page 77 and 6N6P-IR.
Revision 4, 10/02/2015: Updated power tube links for 6080/6AS7G by Mordy's post 9059 on page 604 (3)


----------



## lupoal

@triod750

exactly what I was looking for! thank you! 

I'm waiting for my new printer, should be here middle next week... then I will print it too... precious info


----------



## Arro

Images of the 6SJ7 in the I+ and the MK IV SE. The weather was much brighter this morning so I was able to take some pictures with my ancient digital camera.



I also tried solving the issue about reaching into the MK IV to get to the jumpers. I had the idea of attaching jumper wires to the internal pins which would then allow the jumpers to be changed externally. However the access holes on the bottom of the amp don't leave enough room for me to be able to fit the female end of the jumper wires to the internal pins with tweezers. I'll have to rethink that one.
Link if anyone is unsure what I mean by jumper wires


----------



## johanchandy (Dec 6, 2020)

So I got the LD1+, installed the burson v6 classic opamp and the mullard m8100 tubes, and it sounds pretty decent but I find it fatiguing with my Grado hemp, I was hoping for a smoother more relaxed sound. I even find the stock tubes better in this regard. What is a nice warm bassy tube that would work for my setup? I'm using the modi 3 as a dac and the schiit heresy is amazing with the hemp for a live sound, I was hoping the LD1+ would give me a more relaxed alternative. Could this also be because it probably needs more burn-in as well?

I'm really loving the stock tubes soo much more paired with the burson v6c, really smooth and musical, but they're a tad noisy, what would be an upgrade to the stock tubes that share a similar sound?

Would the  Sylvania _5654W_ 's be the tubes for me?


----------



## MIKELAP

lupoal said:


> @triod750
> 
> exactly what I was looking for! thank you!
> 
> I'm waiting for my new printer, should be here middle next week... then I will print it too... precious info


Dont know if you have this .Its a list i made regarding interesting infos in this thread


----------



## mab1376

Here is the tube chart I saved in excel: https://www.dropbox.com/s/sencw7s57iy92sw/Tube Chart.xls?dl=0


----------



## Arro

johanchandy said:


> what would be an upgrade to the stock tubes that share a similar sound?



Shanghai 6J1. They're an improvement over the stock Beijing 6J1 in every way while still keeping the soft treble that seems to be a characteristic of NOS Chinese tubes. You can tell them apart from the Beijing and Shuguang 6J1 by the atomic whirl logo.

The one problem you might have is finding them. There's very little information about the different Chinese tube factories available on the English speaking internet and Chinese sellers don't usually distinguish tubes by the factory that made them.


----------



## lupoal (Dec 6, 2020)

@MIKELAP @mab1376

thanks a lot!
very useful tools to not get lost inside this really huge thread

one question... I’ve read many of the pages, not all 800 but for sure a lot of them, and didn’t find a word about changing the output capacitors... now I understand that here is about tube rolling and for modding there’s another thread but... that possible mod it is not mentioned here (to be honest I don’t even know if it is mentioned there) because of... not applicable in MK3 or MK4 that are the most common LD here? ... or... because it does not improve the sound so much, it doesn’t worth? ... it is more difficult / dangerous then rolling tubes? (well, I’ve seen here some quite complicate DIY adapters... so I don’t think it a matter of difficulty)


----------



## triod750

triod750 said:


> Could it be this? I have saved it as a document.
> 
> Posted by Acapella 2014, I think.
> ___________________________________________________________________________
> ...



To this list from Acapella I would like to add Melz 6H12C/6N12S that is close to 5687 in electric parameters but more resolving soundwise. 5687, while sounding good, to me are more 'distant' and closed in as 'power tubes'. I have not yet tried them as 'drivers'. They have the same pinout as 6SN7 so the same adapters can be used and they don't need external heater PSU.


----------



## johanchandy (Dec 6, 2020)

Arro said:


> Shanghai 6J1. They're an improvement over the stock Beijing 6J1 in every way while still keeping the soft treble that seems to be a characteristic of NOS Chinese tubes. You can tell them apart from the Beijing and Shuguang 6J1 by the atomic whirl logo.
> 
> The one problem you might have is finding them. There's very little information about the different Chinese tube factories available on the English speaking internet and Chinese sellers don't usually distinguish tubes by the factory that made them.


Thank you! I'll try to find a pair!

Edit: found a nos matched pair an ebay, can't wait to get them!


----------



## lupoal

... any opinion about GE 6SN7 GTA?


----------



## TrollDragon

Arro said:


> Images of the 6SJ7 in the I+ and the MK IV SE. The weather was much brighter this morning so I was able to take some pictures with my ancient digital camera.
> 
> 
> 
> ...


I did this with my MK IV. 
The red DPST switches toggled EF92/95. The black DPDT (Center Off) switched did the strapping. Unfortunately there was a hum with certain tubes and was most likely due to the way I routed the strapping wires from the switches to the sockets. The only problem with the MK IV is once you remove the face or backplate you get hum. In order to test the layout you have to put the amp back together again. The board is a PiTA to remove so I spent a fair bit of time trying to solve the hum issue and eventually abandoned the switches.

If you only put switches in for EF92/95 I don't think that would generate any hum. I believe that it was once I tied into the grids, the problem surfaced. Probably better shielding and routing on those wires would have fixed it.


----------



## TrollDragon

Majestic version... 

Voskhod 6Н2П-ЕБ driver.


----------



## TrollDragon (Dec 7, 2020)

lupoal said:


> @MIKELAP @mab1376
> 
> thanks a lot!
> very useful tools to not get lost inside this really huge thread
> ...


If you have a look at this post here, this user did quite a bit of circuit modification to his LD MK III, there might be something in that you can apply to your amp.
https://www.head-fi.org/threads/little-dot-mk-iii-mods.439449/page-10#post-10697619

The big problem with modifying a LD MK III/IV is getting the board out of the case as you have to unsolder the transformer connections to slide it out and work on it. You can't run the amp with the board removed from the chassis due to the transformer wires not being long enough.  It should be much easier to mod the MK II since the whole bottom comes off of the amp.


----------



## Arro

TrollDragon said:


> I did this with my MK IV.
> The red DPST switches toggled EF92/95. The black DPDT (Center Off) switched did the strapping. Unfortunately there was a hum with certain tubes and was most likely due to the way I routed the strapping wires from the switches to the sockets. The only problem with the MK IV is once you remove the face or backplate you get hum. In order to test the layout you have to put the amp back together again. The board is a PiTA to remove so I spent a fair bit of time trying to solve the hum issue and eventually abandoned the switches.
> 
> If you only put switches in for EF92/95 I don't think that would generate any hum. I believe that it was once I tied into the grids, the problem surfaced. Probably better shielding and routing on those wires would have fixed it.



I remember reading about your mod earlier in the thread. It would have been a great mod if not for the hum. My solution is much less impressive. The jumper wire would just act as an extension to the jumper pins on the circuit board. Instead of needing to reach inside the amp with either pliers or tweezers it would be possible to just flip it over and change the jumpers on the male end of the jumper wire.


----------



## lupoal

@TrollDragon 
thank you


----------



## TrollDragon

Arro said:


> I remember reading about your mod earlier in the thread. It would have been a great mod if not for the hum. My solution is much less impressive. The jumper wire would just act as an extension to the jumper pins on the circuit board. Instead of needing to reach inside the amp with either pliers or tweezers it would be possible to just flip it over and change the jumpers on the male end of the jumper wire.


I think the jumper wires will work perfectly.


----------



## triod750

I have received my adapters and psu from @Deyan. I previously posted a photo of them. First one put to use is one made after MIKELAP:s design; 6AK5 to whatever - in my case ECC88, 6CG7, 6N6P etc. 



Using this adapter I have been trying a NOS Mazda ECC804 as per previous recommendations from Gibosi and JazzVinyl. Until now C3g have been my endgame tubes as drivers with Melz 6H8C/6N8S and Melz 6H12C/6N12S. Although my ECC804 has few hours so far I have to say it has my preference with the music I have tried; an acoustical jazz quintet and Joe Bonamassa. It gives a better balance to the frequency range, a more natural tone to instruments and better texture to especially the upright bass. And the piano. And the trumpet. And the saxophone. And I can listen to Bonamassa at a much higher volume. 
Most impressive.

Mind you- this is early impressions. I bet they won't change.

Thank you, Deyan, Gibosi, JazzVinyl.

I have plenty more combinations to explore. I'm happily retired.


----------



## triod750

Right now listening to Sylvania 6SN7W as driver and a pair of GE 6BX7GT as power. All adapters working well and dead silent background. All heaters fed from Deyan made PSU. Input is a tower of power - three stacked adapters. First ; bottom dual 6AK5 to single ECC88, next; bottom ECC88 with heater input to top ECC88 or, with the use of a switch, ECC81,82 or 83, next; ECC88 to 6SN7. On its way also; bottom ECC88 to 6N7. Forgot to mention the secret weapon; adapters with bottom 6SN7 to top dual GEC A2293. Thank you @Deyan


----------



## triod750

Today I have tried Tung-Sol Chatham 6080 with Mazda 804. First strong impression is that they in my amp are far behind Melz, both 6H8C and 6H12C, in presenting my jazz quintet in a natural way. Red Mitchell tuned his up-right bass like a cello. That was his trade mark. The sound is very special and T-S Chatham makes a blur of it. Even if these tubes could develop with use they are so far behind in this amp that it's highly unlikely they ever will be on par. Maybe for some other music but I doubt it.
(I'm well aware of that this circuit wasn't designed for this tube. 6H12C is much closer to what it was designed for).

I also tried a pair of 6H13C Winged C from 1963 that I have had waiting 'forever'. They are much closer to Melz and could very well become an interesting alternative, especially for other kinds of music. The right (for them) driver might make them deliver. Since they are NOS they might become even better. Right now they are 'leaner' than Melz. I have a few 6SN7 that might change this.


----------



## triod750

Today I have tried the pair of 6H13C first with Ken-Rad 6SN7GTA with a less favoured outcome and now with a Brimar 6SN7GT (marked with a P over a 4 to the left and 1 over a 4 to the right of the 'BRIMAR' on the socket. @gibosi will probably tell you what that means). This combination has a lot going for it. So much so that I don't want to make any changes for a while. I can't say that it is better than 804 with 6N12S but somewhat different. More agile maybe. More bite, but not overly so, at least not with this jazz quintet. (Yes, I will listen to something else too). But if you want to, you can find 'West of the moon' with Bosse Broberg, Gosta Rundqvist, Joakim Milder, Thomas Lofgren and, not least, Red Mitchell on Spotify. My version is better than that. I listen to CD. Semi-old school.


----------



## MIKELAP




----------



## gibosi

triod750 said:


> Today I have tried the pair of 6H13C first with Ken-Rad 6SN7GTA with a less favoured outcome and now with a Brimar 6SN7GT (marked with a P over a 4 to the left and 1 over a 4 to the right of the 'BRIMAR' on the socket. @gibosi will probably tell you what that means). This combination has a lot going for it. So much so that I don't want to make any changes for a while. I can't say that it is better than 804 with 6N12S but somewhat different. More agile maybe. More bite, but not overly so, at least not with this jazz quintet. (Yes, I will listen to something else too). But if you want to, you can find 'West of the moon' with Bosse Broberg, Gosta Rundqvist, Joakim Milder, Thomas Lofgren and, not least, Red Mitchell on Spotify. My version is better than that. I listen to CD. Semi-old school.



Unfortunately, those characters (P414) don't appear to conform to a normal Brimar production code, and I have no idea how to interpret them. 

http://www.g8hqp.me.uk/audio/brimarcodes.html


----------



## mordy

gibosi said:


> Unfortunately, those characters (P414) don't appear to conform to a normal Brimar production code, and I have no idea how to interpret them.
> 
> http://www.g8hqp.me.uk/audio/brimarcodes.html


Add to this that towards the end of the tube era Brimar imported many tubes from Eastern Europe and put their name on them. 
A wild guess: P 
                      4 
         could mean March 1964


----------



## triod750

MIKELAP said:


>


But...there are a lot of pics in this thread. My posts are worthless due to losing my Kodak Instamatic more than forty or maybe fifty years ago. Neither me nor my phone is smart. But I am clever - I save my money for tubes.


----------



## triod750

gibosi said:


> Unfortunately, those characters (P414) don't appear to conform to a normal Brimar production code, and I have no idea how to interpret them.
> 
> http://www.g8hqp.me.uk/audio/brimarcodes.html



They look like this, the tubes I mean, but you don't see the codes on this photo: http://www.tangotubes.com/bilder/0608/Brimar6SN7GT(2).jpg


----------



## triod750

mordy said:


> Add to this that towards the end of the tube era Brimar imported many tubes from Eastern Europe and put their name on them.
> A wild guess: P
> 4
> could mean March 1964



And: 1
        4
could mean one for you?


----------



## gibosi

triod750 said:


> They look like this, the tubes I mean, but you don't see the codes on this photo: http://www.tangotubes.com/bilder/0608/Brimar6SN7GT(2).jpg



Yes, I have a similar tube with 12 and 3 on the right. And I am inclined to guess it is December, 1953, but this is just a guess. And so yours, with 1 and 4 might be January, 1954. But again, this is just a WAG.  And I have no idea what P and 4 might indicate. Mine has only one digit on the left, a 3.


----------



## triod750

gibosi said:


> Yes, I have a similar tube with 12 and 3 on the right. And I am inclined to guess it is December, 1953, but this is just a guess. And so yours, with 1 and 4 might be January, 1954. But again, this is just a WAG.  And I have no idea what P and 4 might indicate. Mine has only one digit on the left, a 3.



Sounds reasonable. I was told they were from the early fiftees. They can also be seen here: https://www.head-fi.org/threads/the-reference-6sn7-thread.117677/page-46
The P 4 might mean peace for you? Or maybe they have to be two or more to mean that. (Sorry, just pulling Mordy's leg. Didn't want to mention pee. Won't mention pee).


----------



## mordy

triod750 said:


> And: 1
> 4
> could mean one for you?


Based on the picture it is a Brimar made 6SN7GT - somewhat pricey today with people asking over $300 for a single.
However, it looks like I found a bargain - a G.E.C 6SN7GT for GBP 40 ($54) and free shipping!
Too good to be true? Well, let's find out...
https://www.ebay.com/itm/G-E-C-6SN7...572316?hash=item1aa7fdb75c:g:UOAAAOSw9wVfmb6e
So here we have a rebranded Eico American made GE 6SN7GT that you can buy for $10.
The free shipping is only GBP 23 ($30).
Since I recently dealt with a different unpleasant British seller that repairs TVs and seeing that this seller is into vintage radios I have to draw the conclusion that some British people are strange. The other guy claimed that he has 60 years experience and knows everything about date codes, but then he was unable to explain a Mazda date code. And yes, he said that all tubes sound the same.....
Caveat emptor!


----------



## triod750

mordy said:


> Based on the picture it is a Brimar made 6SN7GT - somewhat pricey today with people asking over $300 for a single.
> However, it looks like I found a bargain - a G.E.C 6SN7GT for GBP 40 ($54) and free shipping!
> Too good to be true? Well, let's find out...
> https://www.ebay.com/itm/G-E-C-6SN7...572316?hash=item1aa7fdb75c:g:UOAAAOSw9wVfmb6e
> ...



If only I had known about the price I would have paid much more. My pair cost me about $23, measuring almost NOS from a reliable seller.


----------



## mordy

triod750 said:


> If only I had known about the price I would have paid much more. My pair cost me about $23, measuring almost NOS from a reliable seller.


I have the 25V version (13D1) of the Brimar 6SN7and paid $10....


----------



## mordy

mordy said:


> I have the 25V version (13D1) of the Brimar 6SN7and paid $10....


Triod750 inspired me to dig out my Brimar 25SN7 AKA 13D1. It is rebranded Haltron and from 1962. The 25V tubes were intended for aircraft use. There is a US made tube 1633 that is a similar 25V tube. 
The obligatory picture:




This tube has a nice, mellow sound. It is one of the favorites of amp builder Glenn and the reason my amp has a 25V switch.


----------



## triod750

Mellow is good to make biting behave!!


----------



## Arro

triod750 said:


> Today I have tried the pair of 6H13C first with Ken-Rad 6SN7GTA with a less favoured outcome and now with a Brimar 6SN7GT (marked with a P over a 4 to the left and 1 over a 4 to the right of the 'BRIMAR' on the socket. @gibosi will probably tell you what that means). This combination has a lot going for it. So much so that I don't want to make any changes for a while. I can't say that it is better than 804 with 6N12S but somewhat different. More agile maybe. More bite, but not overly so, at least not with this jazz quintet. (Yes, I will listen to something else too). But if you want to, you can find 'West of the moon' with Bosse Broberg, Gosta Rundqvist, Joakim Milder, Thomas Lofgren and, not least, Red Mitchell on Spotify. My version is better than that. I listen to CD. Semi-old school.



With British made tubes with an indecipherable factory code, it can be useful to look up images of the CV equivalent and see if there are any tubes resembling the ones that you have. It's not exact but if you also factor in the suspected date of your tubes it should give you a hint as to what factory had the equipment to manufacture that type of tube at the time. The clear glass Brimar CV1988s with the scalloped top mica and 50s date codes have the factory code FB which is Foots Cray.


----------



## triod750

Last night I listened to 6H13C with Yugo 6HM5 as drivers. In this combination 6HM5 were elevated to a new level. But in the long run I experienced a nagging grating feeling. Today I changed drivers to Philips 5654SQ. The listening became much more relaxed. I will have to wait with a comparison. It is almost ridiculous to look at the amp. These 5654 are soo small compared to the big bottles. It's a pity I lost that Instamatic since this is a sight to be seen.


----------



## triod750

Forgot to mention that the amp seems to be as warm with these monster tubes as with 6N6P. No measurements, just touching it with my fingers. The 6080 tubes generates much more heat. I guess the adapter and socket saver with heater inlet isolates a lot of generated heat from getting into the amp.


----------



## mordy

triod750 said:


> Forgot to mention that the amp seems to be as warm with these monster tubes as with 6N6P. No measurements, just touching it with my fingers. The 6080 tubes generates much more heat. I guess the adapter and socket saver with heater inlet isolates a lot of generated heat from getting into the amp.
> [/QUOTE
> The socket savers act as insulators, but it seems to me that the main reason the amp does not get so hot is because of the external power supply driving the 6H13C - the transformer in the amp does not have to work so hard.
> An inexpensive infra-red thermometer works fine on tubes and amps and is fun to use. As a rule, the amp should not exceed 80C to run safely.


----------



## triod750

You might well be right about the reason but how about the very big difference to the touch compared to 6080? (That difference doesn't contradict your suggestion).


----------



## triod750

Just now I'm listening to 6H13C with the trusty C3g. It's like riding a sportscar instead of a bike. Never mind the inadequate comparison. Just wanted to say that it's a big difference. Much more coming through. Plenty of detail without being too much, at least not yet. Well textured bass for instance. Will take some time to find out if something is lacking.


----------



## mordy

triod750 said:


> You might well be right about the reason but how about the very big difference to the touch compared to 6080? (That difference doesn't contradict your suggestion).


You are right - the 6080 tubes tend to run much hotter than the 6AS7 family even though they both draw 2.5A. Don't know why, but it could have to do with the materials, internal construction and the size of tube.


----------



## triod750

Just lighting up a pair of coin base RCA 6BX7GT before going to bed. They don't look exactly robust. First impression is that they are rather powerful. Next impression - not bad at all. Three minutes of experience...
With C3gee...


----------



## mordy

triod750 said:


> Just lighting up a pair of coin base RCA 6BX7GT before going to bed. They don't look exactly robust. First impression is that they are rather powerful. Next impression - not bad at all. Three minutes of experience...
> With C3gee...


The best sounding 6BX7 tubes are supposed to be the early 50’s Sylvania parallel plates, but in general it is a good sounding tube. I am not aware of a current production of such a 1.5A tube but if it was available I think it would find use in many amps.


----------



## triod750

Regarding heat - although 6N6P and 6N12S are electrically very close,and both fed from Dotty's own transformer, 6N12S runs much cooler than 6N6P. Big difference.

Regarding 6BX7GT; I found this RCA pair and a GE pair NOS on a local auction site and had to try them. As luck would have it, they were pretty cheap (and more cheap than pretty).


----------



## triod750

Quite a surprise, really, these RCA 6BX7GT made from obtanium. They are to my ears and my music clearly better than the 6N6P versions I have tried. They have 'cooked' for several hours and are reproducing voices and music more freely and expansive than I ever expected. They have quite a 'naturalness' to them. Better than a few 6SN7 versions I have tried too, as well as 5687. Easy listening. Nothing congested. Notes are breathing. (Company is C3g).
This ride is a riot! Tasting all these different flavours, I mean.


----------



## triod750

Spaciousness was the word I unconsciously was looking for. I use the humble Sennheiser HD650 and this combination (right now GE 6BX7GT) gives a fuller experience than 'standard' tubes has been able to. I just might want a little more 'body' which I can get by experimenting with drivers/input. I don't say that they (6BX7GT) are better than anything or everything else - I just say that they surprise me. 

The box for the external heater psu has the same footprint as my Dotty MKIVSE and I have the amp standing on the psu. I was a little worried of electrical interference of som sort but can't hear anything of the kind.


----------



## gibosi

triod750 said:


> Spaciousness was the word I unconsciously was looking for. I use the humble Sennheiser HD650 and this combination (right now GE 6BX7GT) gives a fuller experience than 'standard' tubes has been able to. I just might want a little more 'body' which I can get by experimenting with drivers/input. I don't say that they (6BX7GT) are better than anything or everything else - I just say that they surprise me.
> 
> The box for the external heater psu has the same footprint as my Dotty MKIVSE and I have the amp standing on the psu. I was a little worried of electrical interference of som sort but can't hear anything of the kind.



I personally like the 6BX7. And in a very different amp, I especially like the Tung-Sol 6BX7, but the GE and RCA are not far behind. And if you want to go crazy, Fivre and Toshiba also made this tube.


----------



## triod750

I am crazy already and I guess there's no cure for that. Toshivre, you say? And Tong-Syl? Have to go looking. But I'm not a good looker...

I am wondering about something else. My 'socket saver' heater adapter for ECC88 to next adapter which are ECC88 to 6SN7 and ECC88 to 6N7/ECC31 is switchable from ECC88 to ECC81,82,83. I wonder what pinout that gives me for those adapters (6SN7 and 6N7) when switched to ECC81. What tubes could be used there, as input?


----------



## gibosi

triod750 said:


> I am crazy already and I guess there's no cure for that. Toshivre, you say? And Tong-Syl? Have to go looking. But I'm not a good looker...
> 
> I am wondering about something else. My 'socket saver' heater adapter for ECC88 to next adapter which are ECC88 to 6SN7 and ECC88 to 6N7/ECC31 is switchable from ECC88 to ECC81,82,83. I wonder what pinout that gives me for those adapters (6SN7 and 6N7) when switched to ECC81. What tubes could be used there, as input?



One wonderful tube that has the same pinout as 12A-7, that is, ECC81,82,83, but sometimes a bit expensive, is an E80CC / 6085.    This tube was manufactured by Philips and Hungarian Tungsram.


----------



## triod750

gibosi said:


> One wonderful tube that has the same pinout as 12A-7, that is, ECC81,82,83, but sometimes a bit expensive, is an E80CC / 6085.    This tube was manufactured by Philips and Hungarian Tungsram.



Thanks, Gibosi. I will look for a NOS cheepy. Wonderful is pretty good to me. Right now I am trying something wonderful. I was going to compare 6BX7GT with 6N12S and decided to feed the latter from the external PSU. Could that result in a difference compared to Dotty's own transformer? Don't know yet, but Red Mitchell's cello tuned upright bass sounds just wonderful. Better texture than with raw 6BX7GT. They might change with more time but this pair of 6N12S has not seen much use yet either.


----------



## mordy

triod750 said:


> Thanks, Gibosi. I will look for a NOS cheepy. Wonderful is pretty good to me. Right now I am trying something wonderful. I was going to compare 6BX7GT with 6N12S and decided to feed the latter from the external PSU. Could that result in a difference compared to Dotty's own transformer? Don't know yet, but Red Mitchell's cello tuned upright bass sounds just wonderful. Better texture than with raw 6BX7GT. They might change with more time but this pair of 6N12S has not seen much use yet either.


It seems entirely plausible that a different transformer will have an effect on the sound. We are always told that the transformer is the most important and most expensive component of a tube amp.
A lot of equipment have options of an upgraded power supply.


----------



## TrollDragon

mordy said:


> It seems entirely plausible that a different transformer will have an effect on the sound. We are always told that the transformer is the most important and most expensive component of a tube amp.
> A lot of equipment have options of an upgraded power supply.


Audio output transformers are important and quality ones are quite expensive due to the core materials required. It takes quite a bit of engineering to make a transformer that has a frequency response of 20Hz - 20kHz with minimal output deviation across that range. The old rule of thumb is, the bigger the core the better the frequency response.
https://www.aikenamps.com/index.php/output-transformers-explained

Not quite the same for power transformers, as long as they can provide the voltage and current needed, it wouldn't make any difference. If the transformer is not up to spec or has too much of a requirement on it, then that would alter the sound due to all the voltages being off.


----------



## mordy

TrollDragon said:


> Audio output transformers are important and quality ones are quite expensive due to the core materials required. It takes quite a bit of engineering to make a transformer that has a frequency response of 20Hz - 20kHz with minimal output deviation across that range. The old rule of thumb is, the bigger the core the better the frequency response.
> https://www.aikenamps.com/index.php/output-transformers-explained
> 
> Not quite the same for power transformers, as long as they can provide the voltage and current needed, it wouldn't make any difference. If the transformer is not up to spec or has too much of a requirement on it, then that would alter the sound due to all the voltages being off.


Thanks for the information. I don't understand that much about these things, but I do remember when I mentioned somewhere that I was using an old PC power supply for external power to tubes that I was told that some inexpensive power supplies can be noisy. If I understood correctly, even though the voltage and current are OK, electric noise can be introduced by a power supply.


----------



## TrollDragon

mordy said:


> Thanks for the information. I don't understand that much about these things, but I do remember when I mentioned somewhere that I was using an old PC power supply for external power to tubes that I was told that some inexpensive power supplies can be noisy. If I understood correctly, even though the voltage and current are OK, electric noise can be introduced by a power supply.


Yes indeed, switching power supplies can be very noisy.


----------



## lupoal

need suggestion/help from very expertise people here ... I’ve recently bought a pair of Marconi 6SN7GT made in Canada... bad boys three holes black plates, togheter with 6HM5 gain 5 they sound marvellous to me

so I would like to buy a spare couple without paying a fortune (the Marconi costed me roughly 50 bucks) and without buying something that sound different (or is a fake)... so the problem of rebranding... here is a picture of my tubes, could you suggest me what looking for and what avoid? Thks a lot


----------



## gibosi

lupoal said:


> need suggestion/help from very expertise people here ... I’ve recently bought a pair of Marconi 6SN7GT made in Canada... bad boys three holes black plates, togheter with 6HM5 gain 5 they sound marvellous to me
> 
> so I would like to buy a spare couple without paying a fortune (the Marconi costed me roughly 50 bucks) and without buying something that sound different (or is a fake)... so the problem of rebranding... here is a picture of my tubes, could you suggest me what looking for and what avoid? Thks a lot



The most important thing to look for is "made in Canada" etched into the glass. And then, three holes, black plates.

However, only Sylvania manufactured the "Bad Boy", and they manufactured it in the US, not Canada. And if you were to purchase a Sylvania with three holes and black plates, it will likely sound different. But as I don't have the Canadian Marconi, I can't say for sure.


----------



## mordy

lupoal said:


> need suggestion/help from very expertise people here ... I’ve recently bought a pair of Marconi 6SN7GT made in Canada... bad boys three holes black plates, togheter with 6HM5 gain 5 they sound marvellous to me
> 
> so I would like to buy a spare couple without paying a fortune (the Marconi costed me roughly 50 bucks) and without buying something that sound different (or is a fake)... so the problem of rebranding... here is a picture of my tubes, could you suggest me what looking for and what avoid? Thks a lot


There is a possibility that these tubes were made by GE Canada for Marconi Canada. To get a better price you would have to look for a tube labelled GE with the identical construction, Made In Canada and try to find a private seller on eBay with a better price. Or look for the Marconi brand from a private seller.
There are several different Marconi versions from different countries and manufacturers so it is important to look for the identical one that you like.
*PPO* - patience pays off....
Found this seller in India that has Canadian GE labeled tubes that look similar to the Marconi Canada tubes you have but the price is too high....



https://www.ebay.com/itm/1MP-6SN7GT...068686?hash=item2f382f05ce:g:BAQAAOSw5PldsCBq



Possibly it is the same tube....


----------



## mordy

lupoal said:


> need suggestion/help from very expertise people here ... I’ve recently bought a pair of Marconi 6SN7GT made in Canada... bad boys three holes black plates, togheter with 6HM5 gain 5 they sound marvellous to me
> 
> so I would like to buy a spare couple without paying a fortune (the Marconi costed me roughly 50 bucks) and without buying something that sound different (or is a fake)... so the problem of rebranding... here is a picture of my tubes, could you suggest me what looking for and what avoid? Thks a lot


There is a possibility that these tubes were made by GE Canada for Marconi Canada. To get a better price you would have to look for a tube labelled GE with the identical construction, Made In Canada and try to find a private seller on eBay with a better price. Or look for the Marconi brand from a private seller.
There are several different Marconi versions from different countries and manufacturers so it is important to look for the identical one that you like.
*PPO* - patience pays off....
Found this seller in India that has Canadian GE labeled tubes that look similar to the Marconi Canada tubes you have but the price is too high....



https://www.ebay.com/itm/1MP-6SN7GT...068686?hash=item2f382f05ce:g:BAQAAOSw5PldsCBq


----------



## lupoal

@gibosi @mordy 

thank you both 

yes I tough the description “bad boy” was a fake description but... ok, I just tried and sound is very good so ok... what could be the right price level? I’ve found a couple of GE Canada (same as those in my hands) declared NOS from Italian dealer... but he ask 135$... quite expensive


----------



## triod750

lupoal said:


> @gibosi @mordy
> 
> thank you both
> 
> yes I tough the description “bad boy” was a fake description but... ok, I just tried and sound is very good so ok... what could be the right price level? I’ve found a couple of GE Canada (same as those in my hands) declared NOS from Italian dealer... but he ask 135$... quite expensive



If I want expensive tubes it seems as a good option to buy from Italy. That's my impression when looking at eBay.


----------



## gibosi

lupoal said:


> @gibosi @mordy
> 
> thank you both
> 
> yes I tough the description “bad boy” was a fake description but... ok, I just tried and sound is very good so ok... what could be the right price level? I’ve found a couple of GE Canada (same as those in my hands) declared NOS from Italian dealer... but he ask 135$... quite expensive



As you paid about $50 for yours, I think $50 or less would be a good price.


----------



## mordy (Dec 20, 2020)

Can anybody tell me what is "bad" and "boy" about tubes? IMHO these are now just fictitious imaginations of unscrupulous sellers trying to jack up the prices. A whole plethora of fake "bad boys" seem to exist in addition to the original Sylvania one.
My theory is that to the average person tubes of the same category look pretty much the same. Sellers are seizing on obvious clues that make certain tubes easy to identify in order to drive up prices. Such examples are a red base, pinched waist, curved base, blacked out glass etc - these are things anybody can notice. And, obviously, the most expensive tubes sound the best...
On the flip side (and for us plus side) there are great sounding very inexpensive tubes that get no publicity such as certain US made all metal tubes because they are ugly, have no tube glow and oftentimes rust on them (which has no effect on the sound).
Anyhow - found an account how the term "Bad Boy" came about:

"The name "bad boy" was first applied to this particular vintage Sylvania 6SN7 by Robert Hutton back in 2001 or 2002. Just as the Tung Sol BGRP is possessed of certain special sonic characteristics that make it a highly sought after tube, so too the '52 Sylvania. It has a sonic presentation unlike any other Sylvania 6SN7. A substantial cache of US Navy surplus '52 bad boys was unearthed in Australia early in the past decade, and at first the gentleman that discovered the cache was selling them on eBay for $50/pair. Robert was among the first, if not the first, to write about their virtues. _*He dubbed them bad boys due mainly to their staggering ability to produce bass.*_"

Another definition:
_*The "bad boy" designation signifies a tube that has a high market value, regardless of whether it actually has superior sonics. *_

And here is how you can determine if it is a real one:
1)3 hole black T plates
2)Bottom getter flashing 1/3 way up the tube
3)Shiny silver top and bottom rectangular mica. The top mica has three small triangular edges bent down on each side.
4)Copper grid posts
5) Date code of 2xx(or possibly 1xx or 3xx) were 1, 2 or 3 represent 1951, 1952 or 1953 and xx represents the week.
6)Full black bottom base with Sylvania or JAN-CHS-6SN7GT in green letters

(In short, only three hole plate JAN-CHS Sylvania tubes with green print from 1951-1953 qualify)


Buyer beware!


----------



## triod750

The true Bad Boys are the sellers .


----------



## MIKELAP

mordy said:


> Can anybody tell me what is "bad" and "boy" about tubes? IMHO these are now just fictitious imaginations of unscrupulous sellers trying to jack up the prices. A whole plethora of fake "bad boys" seem to exist in addition to the original Sylvania one.
> My theory is that to the average person tubes of the same category look pretty much the same. Sellers are seizing on obvious clues that make certain tubes easy to identify in order to drive up prices. Such examples are a red base, pinched waist, curved base, blacked out glass etc - these are things anybody can notice. And, obviously, the most expensive tubes sound the best...
> On the flip side (and for us plus side) there are great sounding very inexpensive tubes that get no publicity such as certain US made all metal tubes because they are ugly, have no tube glow and oftentimes rust on them (which has no effect on the sound).
> Anyhow - found an account how the term "Bad Boy" came about:
> ...


Am i rich mordy ?


----------



## triod750

MIKELAP said:


> Am i rich mordy ?



Can't answer for Mordy but that is a pretty good boy but in my opinion not as good as 6SN7W. But I prefer the tone in Melz 6H8C/6N8S. With the right synergy, that is.


----------



## lupoal

you know.., the problem with all these bad-good-what?-boy is that there are too many different versions of the same tube code... year ... manufacturer... bla bla bla... a nightmare...

ok many very useful info are inside this thread and many others inside the 6SN7 thread... but both together are more than 1000 pages and billions of words... here inside there are two very useful chart collecting all the info, it would be very useful something similar where, over the time, people add pictures with descriptions so when a rookie need to double-check to avoid surprise a place to go exist


----------



## triod750

MIKELAP, you showing your Sylvania 6SN7WGT made me visit them again. I now used them with C3g and external psu playing acoustical music. They  were as I remembered them, a bit coloured. That might work well with some electrical music but to me they are like a somewhat dirty window. I changed to the Brimar pair I mentioned previously and the window immediately became clean and clear. In my setup, with my music. With my ears and gear, as Gibosi use to say.

Earlier today I tried RCA 6BX7GT coinbase with Mullard M8100 and CV4010. M8100 was also very colouring but CV4010 was not bad at all. If I had not heard C3g I might have been pretty satisfied with that combination. It needs external psu but is much cheaper than a lot of other combinations in this long and winding thread.

I've had a little mishap with my input adapter. When I am back on track I will try a Melz 6H8C with both 6SN7WGT and these Brimar to hear what change that will result in.


----------



## mordy

MIKELAP said:


> Am i rich mordy ?


If you are satisfied and happy with what you have, then you are rich....

The tube in the picture is a WGT and not the real BB. I have this tube, as well as the Sylvania 6SN7W (and some fake BBs), Tung Sol 6SN7 BGRP and the 7N7 "Frankie" but I could never get myself to really like any of them. (Am I allowed to say this?)
But give me a 6N7/6N7G or 6C5/6J5 variants and now we are talking!


----------



## triod750

I have to add something about these Brimars. I can't remember them sounding this good when used without the external PSU. That is something to compare I think but now I have to go to bed. Almost 02:00 where I live.


----------



## mordy

MIKELAP said:


> Am i rich mordy ?


Mikelap inspired me to check my 6SN7 box to see what's there - any buried riches?
Found six Sylvanias. One is from 1953 6SN7GT but it does not have all the signs of the real BB even though it looks similar with the three hole plate and green print; I think it is called a Chrome Dome. Then a pair of 1954 GTA and four GTBs from 1955-60.

Another box has a Sylvania 1955 GTW Mikelap clone and a couple of 1945 6SN7W rescued by lodkolv from the minefields of pops and explosions. They share the box with a quad of aircraft quality RCA 12SX7.

In the first box there is also a quad of Japanese NEC 6SN7GTB under the Channel Master label - these are good sounding tubes and can still be found inexpensive. And a bunch of others....


----------



## gibosi

lupoal said:


> you know.., the problem with all these bad-good-what?-boy is that there are too many different versions of the same tube code... year ... manufacturer... bla bla bla... a nightmare...
> 
> ok many very useful info are inside this thread and many others inside the 6SN7 thread... but both together are more than 1000 pages and billions of words... here inside there are two very useful chart collecting all the info, it would be very useful something similar where, over the time, people add pictures with descriptions so when a rookie need to double-check to avoid surprise a place to go exist



The following thread is very useful in identifying 6SN7GT

http://www.head-fi.org/t/209782/the-6sn7-identification-guide

And from that thread:

*Sylvania 6SN7GT 1952 “Bad Boy” *
_Also JAN-CHS-6SN7GT
Made only from late 1951 (‘1-48’ examples seen) to 1952. Differs slightly in construction from ‘regular’ Sylvania rectangular top mica 6SN7GTs. Re-labeled bad boys are known to exist._
Base: black, green labels marked ‘2-XX’ (where XX is the week of the year)
Glass: clear
Plates: black, T-plate with 3 holes per plate
Getter: bottom, foil, flashing can extend up to 1/3 of way up tube
Top mica: rectangular with 3 spikes on each of the shorter edges
Other significant features: bottom mica is rectangular. When seen, date codes are vertically arranged (from top to bottom) ‘YWW’ with Y underlined. Y = last digit of year, WW = week number of year.

(I should note that I have seen some Bad Boys manufactured as late as 1953.)


----------



## MIKELAP

This was reach for the sky setup,complete with cloud lol


----------



## mordy

I remember the picture but not the tubes....
Where are the copper pipe adapters?


----------



## MIKELAP

mordy said:


> I remember the picture but not the tubes....
> Where are the copper pipe adapters?


I think those adapters were the first ones I got not sure but tubes are 6AU6 I use to like those a lot still have all of them with new adapters not those Dont know if possible to use these with WA22 in 6SN7 slots with adapters ?


----------



## lupoal

@gibosi 

thank you


----------



## triod750

I have now listened to my Brimars without the external PSU. Yes, they did sound really good, but....laidback compared to when fed by Deyan's PSU. Serious comparison takes time and careful sound level matching and careful listening to different kinds of music and.....I won't go into that. I will most likely use external electrons now when I have them and then, some time in the future, revisit the internal transformer to check my reaction. Imagination is powerful - I can't promise that you would hear what I think I hear.


----------



## mordy

It's simple: Trust your ears! (Barring first time immediate impressions)


----------



## triod750

mordy said:


> It's simple: Trust your ears! (Barring first time immediate impressions)



Yes, my ears are my only instrument. But if there is a difference it can take some time to find out all the aspects of it. Not all of them might be good. Some of them can be bad and eventually take over. I've been there before. What is out of focus in the beginning can develop  to become quite annoying.

I received my adapter for 6N7 today...


----------



## warp2600

I have just received an order of 2pcs TUNG SOL 5654 tubes listed as NOS on ebay. The measurements were not listed in the description but the boxes they came in have them: one is 13.7/5.1 but the other one says 6.5/4.5  Annoyingly different. Does anyone around here know anything about test measurements and minimum values? Thanks.


----------



## mordy

warp2600 said:


> I have just received an order of 2pcs TUNG SOL 5654 tubes listed as NOS on ebay. The measurements were not listed in the description but the boxes they came in have them: one is 13.7/5.1 but the other one says 6.5/4.5  Annoyingly different. Does anyone around here know anything about test measurements and minimum values? Thanks.


The problem is that every tester is different and the testers themselves are not showing accurate readings unless they have recently been calibrated professionally.
People who calibrate testers claim that almost every one they receive  is inaccurate . 
Each tester’s readings have to be compared to it’s own minimum or good readings.
Different manufacturers use different parameters.
You are left with the most sensitive instrument of all - your ears. If it sounds good, that’s it, and don’t worry!


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## warp2600 (Dec 22, 2020)

mordy said:


> The problem is that every tester is different and the testers themselves are not showing accurate readings unless they have recently been calibrated professionally.
> People who calibrate testers claim that almost every one they receive  is inaccurate .
> Each tester’s readings have to be compared to it’s own minimum or good readings.
> Different manufacturers use different parameters.
> You are left with the most sensitive instrument of all - your ears. If it sounds good, that’s it, and don’t worry!


Thanks, Mordy for this lightning fast reply. The seller also responded to my query. I've been concerned because the measurements were so "out of tune" (although they were not listed as a matched pair). He says he used an AVO vcm 163 tester and  both tubes tested NOS and that book values for new tubes are 7.7/4.9
Tomorrow I will try them in the MK3


----------



## triod750

Recently I was very disappointed when listening to a pair of Tung-Sol Chatham 6080. In the same lot a pair of 'ordinary' Tung-Sol 6080 were included. I am listening to them right now with CV4010 as input and they are clearly better, in fact not bad att all. Maybe the first pair is 'tired'. At least it's useless. This pair is quite listenable. That means that I can't write off the 6080 type tubes. Thougt it would be fair to report this. It took about an hour of warming up until they started to sound decent. Another hour had me warmed up to them.


----------



## gibosi

triod750 said:


> Recently I was very disappointed when listening to a pair of Tung-Sol Chatham 6080. In the same lot a pair of 'ordinary' Tung-Sol 6080 were included. I am listening to them right now with CV4010 as input and they are clearly better, in fact not bad att all. Maybe the first pair is 'tired'. At least it's useless. This pair is quite listenable. That means that I can't write off the 6080 type tubes. Thougt it would be fair to report this. It took about an hour of warming up until they started to sound decent. Another hour had me warmed up to them.



It would be useful to know if these tubes look identical? There are two versions of the Tung-Sol / Chatham 6080. One has metal plates and one has graphite plates.  ???


----------



## triod750

gibosi said:


> It would be useful to know if these tubes look identical? There are two versions of the Tung-Sol / Chatham 6080. One has metal plates and one has graphite plates.  ???



They look the same to me. I can see no difference at all. I just changed the CV4010 for C3g and wow! Just better from top to bottom. I will have to listen to this for a while but it's time for bed. Bad timing!


----------



## Rakyat02

Wanna ask some questions relating to the spreadsheet at page 77. Kinda confused as it is but according to the spreadsheet 6BE6 can be used to the socket as it is without tinkering with anything correct?, then how do I use the 6AU6 cause the picture on that page has gone corrupt


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## gibosi (Dec 22, 2020)

Rakyat02 said:


> Wanna ask some questions relating to the spreadsheet at page 77. Kinda confused as it is but according to the spreadsheet 6BE6 can be used to the socket as it is without tinkering with anything correct?, then how do I use the 6AU6 cause the picture on that page has gone corrupt



It is true that the 6BE6 can be run as an EF91/92 or an EF95, with or without the various strappings (socket wire mods). But it will sound different in each of these configurations. So you might want to try all of them to see which sound best to you.

The 6AU6 can be used only in a socket configured as EF95 with the 2/7-Socket Wire Mod.


----------



## triod750

I have given the GE 6BX7GT a lot more time in Dotty together with C3g and think they are better than T-S 6080, 6H13C and coin base 6BX7GT for my music. They have 'matured' and I have adapted, probably. A lot of bang for the buck. That tube type is very popular among owners of another amp, the Glenn OTL. They try a lot of tubes, just like we do. 
Another plus than sound is that the tube, with external heater PSU, runs very cool in Little Dot. It taxes the components less than 6N6P does, I guess. Just guesswork, mind you.


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## triod750

I have something odd to report. When exploring some of the output tubes I found a Raytheon 6SN7GT Bad Boy lookalike and one Sylvania VT231 and put this odd pair together with @Deyan heater PSU. Both were NOS when I received them, the Sylvania pretty cheap since the triodes were unbalanced (something we know is of little importance in Dotty).  Unexpectedly they made some slightly aggressive sounding music quite listenable. I tried a few recordings and enjoyed them. They give a relaxed listening. So much so that they have stayed in service and I have listened to quite a few rock albums. I imagine that the external PSU make them sound a little livelier but still relaxed. (Notice that I wrote 'imagine').


----------



## triod750

Another report. In the late sixties I bought an integrated 'music center'- a BSR Ferguson with a Garrard integrated record player. I also bought, around that time, a set of headphones - the revolutionary Sennheiser HD414. I have needed a set of headphones for my laptop and last week I found at a local auction site a pair of Sennheiser HD414 for about $12:50. They were delivered today and I plugged them in to Dotty. The sound is as charming today as it was back then. Ethereal with Jobim and no disturbing bass .
It gives about 25-35% of what HD650 does (with the same settings). But it is clean.


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## MIKELAP (Dec 30, 2020)

Rakyat02 said:


> Wanna ask some questions relating to the spreadsheet at page 77. Kinda confused as it is but according to the spreadsheet 6BE6 can be used to the socket as it is without tinkering with anything correct?, then how do I use the 6AU6 cause the picture on that page has gone corrupt
> 
> I still have a lot of those with the adapters barely used


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## iansu

Hi 

I am just got the LD mkII, search the drive tube and power tube. Have any suggestions

Drive tube may be mullard M8100, GE5654W and Voshkod 6ZH1P-EV

Power tube, not idea 💡


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## MIKELAP (Jan 1, 2021)

iansu said:


> Hi
> 
> I am just got the LD mkII, search the drive tube and power tube. Have any suggestions
> 
> ...


----------



## MIKELAP

I was looking at the old power tubes review ,where are all the pictures???? like on page 1 there use to be pictures there gone and i've noticed  this on a few thread .What the hell Headfi .A picture worth a thousand words .Really .dissapointed .


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## iansu

Mikelap

Thanks a lot
However Too expensive for 6H30P-DR, Reflektor


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## MIKELAP

iansu said:


> Mikelap
> 
> Thanks a lot
> However Too expensive for 6H30P-DR, Reflektor


The last setup i had with my MK3 was 6sn7 as power tubes with adapter 6sn7 to 6cg7 adapters and C3G as driver tubes with adapters C3G to 6AK5


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## lupoal

iansu said:


> Hi
> 
> I am just got the LD mkII, search the drive tube and power tube. Have any suggestions
> 
> ...



gain 5
EF95
... RCA 6SN7 GTB (adapter to 6N6P required )
... Telefunken EK90


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## lupoal (Jan 9, 2021)

hi,

I‘m driving now couple of 6H8C (1952) with two Telefunken EK90 (EF95) and I’m very happy... I would buy a couple of TFK EK90 as spare parts but they are quite rare... what other brand could I consider to not go too far away from that sound signature?


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## triod750

Looking for spare tubes? https://www.ebay.com/itm/ONE-LOT-OF-19-NOS-TELEFUNKEN-EK90-6BE6-TUBE-/383700152436 

I haven't tried those so I don't know what your sound signature is. But I wish you good luck with your hunt for ultimate synergy.


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## lupoal (Jan 10, 2021)

wow... those would be perfect but... there are more working hours in total in that package then residual in my life   ... just two of those would more then enough (estimated life should be around 10.000 hours)

I will send him a message to see if is possible to buy a smaller quantity... thks for help


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## triod750

lupoal said:


> wow... those would be perfect but... there are more working hours in total in that package then residual in my life   ... just two of those would more then enough (estimated life should be around 10.000 hours)
> 
> I will send him a message to see if is possible to buy a smaller quantity... thks for help



If you enjoy the sound you will hang on to your life as long as the tubes still work


----------



## lupoal

Ok, I’ve found a supplier having 6BE6, all NOS from these brands... Brimar, Philips, Fivre, Zenit, Tungsram... which one should I choose to match with 6H8C?
target is something a little softer then TFK but very different form Siemens (too dry, quite bad imho) and not as soft as Mullard


----------



## MIKELAP

lupoal said:


> Ok, I’ve found a supplier having 6BE6, all NOS from these brands... Brimar, Philips, Fivre, Zenit, Tungsram... which one should I choose to match with 6H8C?
> target is something a little softer then TFK but very different form Siemens (too dry, quite bad imho) and not as soft as Mullard


i have tried these  6BE6 to from Tungsol ,and IBM (1680)6BE6


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## gibosi

MIKELAP said:


> i have tried these  6BE6 to from Tungsol ,and IBM (1680)6BE6



And on the IBM tubes, I see RCA's EIA code, 274.


----------



## Chezpi

Good dear, I am new to this world of high quality audio, and I decided to start this year with an initial setup that gives me good listening quality. I subscribed to Tidal and Quboz so that they can offer me good sound quality and buy some equipment, now this past blackfriday, my first Sennheiser HD6xx from Drop that cost me $ 200, also seeing reviews encouraged me to buy a dac, because previously I didn't have, I also bought the Topping E30, and now I was looking for a good amp. Reading reviews they always strongly recommend that I get myself a tube amp, as compared to a solid amp, the tube amp could get the most out of my purchased headphones, that's why I made it to this part of the forum. I am encouraging myself to buy the Little Dot Mk2 for its cost benefit (180 $) and because it is a good amplifier to start with, reading the first pages and being new in this world it is difficult for me to read the more than 800 pages of this great post. That is why I ask you to help me please, I would like to update the tubes that come by default with the LD Mk2 (2x 6JI + 2x 6N6), according to my Aliexpress seller, he wants to sell me 2x 6JI for 10 USD and 2x 6N6 for 20 USD only For replacement in case the default ones get damaged, he also offered me M8100 / CV4010 for 50 USD and the pair of tubes JAN 5654 for 15 USD but it seems a bit excessive, since looking at the first page of this post, Dept_of_Alchemy recommended the Voshkod 6ZH1P-EV and the pair of these cost $ 24 shipping included and I feel they are the best I can get for now, because my budget is short, I found them on ebay: https://www.ebay.es/itm/ Voshkod-6ZH1P-EV-6J1P-EV-EF95-Matched-Pair-2-Difference-New-Old-Stock / 142890748468 My question is if I am doing well to buy these upgrade tubes on ebay, and if I need a replacement for the 6N6 to order them on aliexpress ($ 16 pair) in case the ones that come by default should fail, or maybe there are better power tubes on ebay and what would they be. Thanks a lot.


----------



## gibosi

Chezpi said:


> Good dear, I am new to this world of high quality audio, and I decided to start this year with an initial setup that gives me good listening quality. I subscribed to Tidal and Quboz so that they can offer me good sound quality and buy some equipment, now this past blackfriday, my first Sennheiser HD6xx from Drop that cost me $ 200, also seeing reviews encouraged me to buy a dac, because previously I didn't have, I also bought the Topping E30, and now I was looking for a good amp. Reading reviews they always strongly recommend that I get myself a tube amp, as compared to a solid amp, the tube amp could get the most out of my purchased headphones, that's why I made it to this part of the forum. I am encouraging myself to buy the Little Dot Mk2 for its cost benefit (180 $) and because it is a good amplifier to start with, reading the first pages and being new in this world it is difficult for me to read the more than 800 pages of this great post. That is why I ask you to help me please, I would like to update the tubes that come by default with the LD Mk2 (2x 6JI + 2x 6N6), according to my Aliexpress seller, he wants to sell me 2x 6JI for 10 USD and 2x 6N6 for 20 USD only For replacement in case the default ones get damaged, he also offered me M8100 / CV4010 for 50 USD and the pair of tubes JAN 5654 for 15 USD but it seems a bit excessive, since looking at the first page of this post, Dept_of_Alchemy recommended the Voshkod 6ZH1P-EV and the pair of these cost $ 24 shipping included and I feel they are the best I can get for now, because my budget is short, I found them on ebay: https://www.ebay.es/itm/ Voshkod-6ZH1P-EV-6J1P-EV-EF95-Matched-Pair-2-Difference-New-Old-Stock / 142890748468 My question is if I am doing well to buy these upgrade tubes on ebay, and if I need a replacement for the 6N6 to order them on aliexpress ($ 16 pair) in case the ones that come by default should fail, or maybe there are better power tubes on ebay and what would they be. Thanks a lot.



You can't go wrong with the Voshkod 6ZH1P-EV. But before you spend too much money on more tubes, I would encourage you to wait until the amp arrives and you can spend some time listening to the default tubes. You just might like them and then no need to upgrade.


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## Chezpi (Jan 14, 2021)

Thank you, and maybe Do you have sellers that you can recommend me?


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## lupoal

before to replace the tube I strongly suggest you to replace the power cable... I replaced the tubes too but the step I've heard replacing the cable was quite important, bigger then replacing, for example, the standard tubes with GE JAN 5654 (please note I'm living in a modern house with almost perfect power net) ... I've done my cable following this project https://www.tnt-audio.com/clinica/ttse.html


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## Chezpi

gibosi said:


> You can't go wrong with the Voshkod 6ZH1P-EV. But before you spend too much money on more tubes, I would encourage you to wait until the amp arrives and you can spend some time listening to the default tubes. You just might like them and then no need to upgrade.


Thanks for the answer, it sounds good to wait for the amplifier and then make decisions, the bad thing is that I am somewhat desperate and I want to have everything at hand because waiting 30-40 days is stressful .. 


lupoal said:


> before to replace the tube I strongly suggest you to replace the power cable... I replaced the tubes too but the step I've heard replacing the cable was quite important, bigger then replacing, for example, the standard tubes with GE JAN 5654 (please note I'm living in a modern house with almost perfect power net) ... I've done my cable following this project https://www.tnt-audio.com/clinica/ttse.html


Thanks for the answer, a question, does the cable have to be of better quality?, because I have a thick cable that was left over from my UPS tower.


----------



## gibosi

Chezpi said:


> Thanks for the answer, it sounds good to wait for the amplifier and then make decisions, the bad thing is that I am somewhat desperate and I want to have everything at hand because waiting 30-40 days is stressful ..



It is important to remember that audio is very subjective. A tube you might think is the very best, another person might think is just OK. Until you know what you like and don't like, it is impossible to know in advance what your favorite tubes will be. So again, my advice is to wait. And after you have listened to your amp with the default tubes for awhile, you will have a better idea what you like and don't like. And then, you can search for tubes that have the sonic character you desire: maybe more bass or more treble, or a more forward midrange or whatever.

Again, patience is a good thing.


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## lupoal (Jan 14, 2021)

@Chezpi
important points are
- geometry: the geometry used in that cable is the same you can find in this patent, search it and read it... you will understand why geometry is the first and most important factor and why doing that cable is important to not braid wires in wrong way





- wire quality: just search for a nice industrial cable, it doesn’t has to be huge... it is important the shielding quality and flexibility ... till now I’ve always used standard cooper cables, I don’t know if 7N does make any sense...I’ve used this one
- braiding the cable will consume roughly the 20% of your target length... so if you want a cable 2m long (sorry I’m not familiar with foot or inch and so on) you need 2m x 3 = 6m + 20% ... roughly 7,2m plus some margin to recover errors in cutting etc.

if you curious about the cable I have done you can look here —> https://melius.club/topic/311948-diy-tnt-tts/#comments


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## Chezpi

lupoal said:


> @Chezpi
> important points are
> - geometry: the geometry used in that cable is the same you can find in this patent, search it and read it... you will understand why geometry is the first and most important factor and why doing that cable is important to not braid wires in wrong way
> 
> ...


Thank you for the info, i will check.


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## TrollDragon

Power cables...   I suppose magic fuses will be next...


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## lupoal (Jan 15, 2021)

are you going to experiment with fuses?

I use to have exactly the same feeling/position you have (about cables I mean)... then because of these Covid boring days I decided to build one... and I changed my opinion about it... but I can understand, playing with tubes, that glows and are thousand all different each other, that are nice in the picture... ok, it is more fun then braid a cable

to keep it simple I'm doing both... you know curiosity is a powerful engine some times bringing unespcted surprises

I discovered that LDII is quite cable sensible ... you know, those misterious things called electrical pollution that could require shielded cable (LD one from factory isn't)... anyway, you will decide to play with fuses or not I'm happy in any case


----------



## Geo70

Hi everyone. I wanted to give a warmer sound to my chain as follows: Pc-usb -> DAC-toppinge30 -> pre-ampTube-03 -> ampli-Icepower-classD final without potentiometer. Which tubes should I upgrade my Tube-03 with that can give me deep bass, not too dry bass.? I had thought of the Mullards. 
 Maybe there is someone here who knows the sound of the ICEpowe 125asx2 amps. Ty


----------



## TrollDragon

Geo70 said:


> Hi everyone. I wanted to give a warmer sound to my chain as follows: Pc-usb -> DAC-toppinge30 -> pre-ampTube-03 -> ampli-Icepower-classD final without potentiometer. Which tubes should I upgrade my Tube-03 with that can give me deep bass, not too dry bass.? I had thought of the Mullards.
> Maybe there is someone here who knows the sound of the ICEpowe 125asx2 amps. Ty


Very few of us here would use those cheap tube buffer amps. IMHO they are a novelty and the tubes are just a selling feature, they run with just enough voltage to get the tube to conduct and alter the sound.

The Little Dot MK 2/3/4 amps used in this thread are all tube OTL amplifiers that run at the proper voltage for optimal operation. How these tubes sound in our amps will not relate to your "tube buffer" amp as the use of tubes in those amps is mostly a gimmick.

There is a large FX-Audio thread over on Audiokarma, they would probably have better suggestions for replacement tubes.


----------



## dtbach

Been lurking here for awhile after getting my little dot mk3 ( not that I ever made it through all 834 pages) and have gotten a variety of driver tubes from the suggestions on the first few pages  (voskod, Millard 8100 and 8161, tung sol and GE JAN).  Just love what the amp can do.  The one thing I will state is I just can’t hear much difference between the various tubes.  I think I like the Tung Sol best but no way in heck could I ever tell what is what in a blind test.  Perhaps by the time I listen to one tube, let it cool down, replace with the next one, let that one warm up I have lost all memory of the nuances of the first.  Anyway my regards to you Golden Ear audiophiles!  Is there a method to your techniques? On the other hand I will be saving money on tubes.  
However I can readily hear differences between headphones so guess will be spending my bucks there.


----------



## triod750

I am happy to report very good result with 12AU7 as input tube via adapter from @Deyan to, for example, General Electric 6BX7GT, RCA 'bisquit' 6BX7GT (impressively and unexpectedly clean sound) and GEC A2293 (four of them - two per channel in adapters from @Deyan) as output tubes. Both input and output tubes get their filament feeding from external psu via adapters , all of it made by @Deyan.

I have had C3g as favourite input tubes for quite some time but they are more 'strident' in the higher registers than 12AU7/ECC82. So far I have tried one Telefunken and two Philips I already had on hand. 12AU7 gives a more relaxed listening without any impression of that something is missing.

I have something else on its way from @Deyan that might provide an alternative to C3g, also without use of external psu. I have high hopes for this, inspired by @gibosi .

Mind you, these are early impressions so don't make too much of it. I want to listen to more music before saying too much. But to me, this seems to possibly be a giant leap in sound quality to my ears. But...we are all different.

(GEC A2293 is supposed to be half a 6AS7g so two of them is a real powerhouse. Compared to the Soviet version of 6AS7g - 6H13C/6N13S - they sound a lot better. I use Sennheiser HD650 with a Mobius cable. I don't know how well these tubes mentioned would cater for the needs of more power hungry headphones. They could easily blow my brains out without sounding distorted).


----------



## triod750

Today , or tonight, I am trying a Ken-Rad 6N7 as input tube via adapter for external psu to cater for the filaments (and to split the dual triodes to 6AK5). The tube is totally NOS and probably needs time to show its colours but it is very promising. For this I was inspired by @mordy . @Deyan provided the neccessary adapters and I found the tube in Portugal. I have shown the adapters and psu in a previous post. The photo is taken by @Deyan.

When listening to a jazz tune a few minutes ago I could not sit still. I found myself dancing around, making all sorts of weird moves. My dog looked both disturbed and disgusted. If you had seen what she saw, you might have looked the same way. Thank you, @mordy, for the inspiration.

(This just might be a first in Dotty. One 6N7 to four A2293. Very versatile amplifier, my LD MKIVSE. I really enjoy the ride). Thank you, @Deyan, for the hardware.


----------



## mordy

triod750 said:


> Today , or tonight, I am trying a Ken-Rad 6N7 as input tube via adapter for external psu to cater for the filaments (and to split the dual triodes to 6AK5). The tube is totally NOS and probably needs time to show its colours but it is very promising. For this I was inspired by @mordy . @Deyan provided the neccessary adapters and I found the tube in Portugal. I have shown the adapters and psu in a previous post. The photo is taken by @Deyan.
> 
> When listening to a jazz tune a few minutes ago I could not sit still. I found myself dancing around, making all sorts of weird moves. My dog looked both disturbed and disgusted. If you had seen what she saw, you might have looked the same way. Thank you, @mordy, for the inspiration.
> 
> (This just might be a first in Dotty. One 6N7 to four A2293. Very versatile amplifier, my LD MKIVSE. I really enjoy the ride). Thank you, @Deyan, for the hardware.


In these days of quarantine exercise is very important lol!


----------



## carrots99 (Jan 31, 2021)

Hi, I was planning on trying either some EF91, EF92 or 6AH6 tubes on my FX Audio Tube 03, but will it make a difference (considering the fxaudio has 2-7 and 5-6 straps, hence they'll be in triode mode)? Just wanted to try something different, other then the regular Ef93 or Ef95 tubes (I've just tried a Brimar 6BE6W -and like it a lot) 
Thanks


----------



## triod750

Tonight I changed output tubes from A2293 with external psu to Melz 6N12S with Dotty's own transformer. While not as powerful I think this combination is truer to tone. It is a different flavour that is very transparent with more space between instruments. Ken-Rad 6N7 still used as input. Worth to remember that my A2293 has not seen much use yet. They might open up eventually. But this combination gives great twang to the strings of upright bass and great piano tones.

I will try the same setup with external psu eventually.


----------



## triod750 (Feb 1, 2021)

Today I have tried Melz 6N12S with Dotty's own transformer after having used the external psu for a while. Using the internal transformer gives a truer tone and more relaxed sound. I am using the 6N7 for input. This tube needs external psu but is very rewarding. I believe it to be a better match for these output tubes than C3g is. I really want to find something to better this but expect that quest to be difficult. I find myself more involved in the music - it is much easier for me to follow what is happening. I give most of the credit for this to the Melz 6N12S. I will keep on trying to find the ultimate input tube for them. I have a pair of adapters on its way to try a pair of tubes that need no external psu.
But remember, as @gibosi always reminds you, my ears and my gear.

(I have a 6N7G on its way too).

Just wanted to add that the 6N12S needs the same adapter that 6SN7 does. It has the same pinout. You can't just use it in Dotty's own sockets.


----------



## triod750

I have now compared the 6N7 to the 12AU7/ECC82 as input tubes to the 6N12S. Preliminary impressions, they couldn't be anything else, is that they both sound very good. With the 12AU7 I am able to enjoy a very clean and relaxed presentation of the music. I could go on listening like forever.
With the 6N7, on the other hand, I am within the music. It's so involving and engaging that I become overwhelmed, in a good way. It's not as relaxing as the first one since it makes me really concentrate on what is going on.
In my opinion they complement each other. If I had to choose between them I would take both, since I can. If I couldn't, I would probably take the 6N7. Or...
Too early to say. But if I had to choose only one pair of output tubes, I would take the Melz 6H12C/6N12S. I haven't listened to all tubes that could be made to work in Dotty and am aware of that I can change my mind in the future but this is where I am today.

My only other experience of tube amps is Audion Silver Night 300B SET, my main amp Triod 750 Push-Pull (4x6B4G with 6922/6DJ8/ECC88 as input) and an EL84 PP. I enjoy listening to Dotty as much as listening to them. It's all about the music.


----------



## triod750

Right now I am listening to the same jazz recording as before, using 6N12S with internal transformer as output and a good Brimar 6SN7GT with external transformer for input. While sounding very good it's interesting to notice that the tone of the piano now comes closer to when using 6N7 and the external psu for the 6N12S. When comparing that setup with and without external psu I found the piano tone more natural without external psu for the 6N12S. This is another proof of that it is all about synergy. The piano tone in this setup is less natural. The difference isn't between bad and good, more between good and better. (I hear the same difference when concentrating on the trumpet).

I don't believe that there is one tube combination that is best for all kinds of music or for all recordings of one kind of music. Too many factors involved.


----------



## triod750

I'm in no way trying to give a masterclass on tubes or on Little Dot, I'm only sharing my impressions. When I first visited this topic/ thread there was an awful lot of pages written, with lots of valuable information. I read it from the beginning, a couple of hundred pages, and then decided to instead read it from the end. By doing this I could jump a lot of tubes and start with so-called end game tubes. So I haven't tried all tubes present in this thread (thanks heaven) and saved some money by doing this. That way I have some money left to spend on tubes that, to my ears, surpass those end game tubes. To my ears. 

I have made these posts aiming at people new to tubes. Main message is that it is all about synergy and to trust one's ears and there is no combination that is good for everything. At least this is my conclusion. And never stop experimenting. It can be very rewarding.
_______________________

I can add that a few hours later this combination sounds a lot better; Brimar 6SN7GT as input and Melz 6N12S as output. I always find that Little Dot (MKIVSE) performs a lot better after several hours of warming up. (It might all be in my head).


----------



## dtbach

triod750 said:


> I'm in no way trying to give a masterclass on tubes or on Little Dot, I'm only sharing my impressions. When I first visited this topic/ thread there was an awful lot of pages written, with lots of valuable information. I read it from the beginning, a couple of hundred pages, and then decided to instead read it from the end. By doing this I could jump a lot of tubes and start with so-called end game tubes. So I haven't tried all tubes present in this thread (thanks heaven) and saved some money by doing this. That way I have some money left to spend on tubes that, to my ears, surpass those end game tubes. To my ears.
> 
> I have made these posts aiming at people new to tubes. Main message is that it is all about synergy and to trust one's ears and there is no combination that is good for everything. At least this is my conclusion. And never stop experimenting. It can be very rewarding.
> _______________________
> ...


I’ve had my little dot now for a couple of months and have tried mullards, voshkods, tung sol, GE, and others.  I can’t tell any difference between any of them.  The main reason is that there is no way to do good A/B comparisons.  By the time you let the first tubes cool down, take them out, put different ones in, power on, let warm up you have at least 5-10 minutes of elapsed time.  A/B comparisons need to b done in less than.2 seconds to be reliable.  Have fun with tube rolling, I’ll spend my money on headphones.


----------



## MIKELAP

The guy having fun and sharing is findings like we all did at one point or another .Nothing wrong with that in my book .its being part of a group and trying stuff


----------



## dtbach

MIKELAP said:


> The guy having fun and sharing is findings like we all did at one point or another .Nothing wrong with that in my book .its being part of a group and trying stuff


I guess it shouldn't have been a reply vs a new post, so you are right.  I guess I expected more of a difference between the various tubes.  Apparently it is extremely subtle at least for me.  I can easily discern differences in speakers and headphones, very slightly in mps vs flac, or in phono stylus.  But none when it comes to cables, DACs or the tubes I got from the recommendations on the first couple of pages of this thread.  I agree it is fun trying out the different tubes, just wish it were more apparent.  I will hand it to you guys for being able to do it.  Has anyone had a buddy change the tubes for you (blind test) and had you tell which ones they put in?  Might be fun to see what happens.


----------



## MIKELAP

dtbach said:


> I guess it shouldn't have been a reply vs a new post, so you are right.  I guess I expected more of a difference between the various tubes.  Apparently it is extremely subtle at least for me.  I can easily discern differences in speakers and headphones, very slightly in mps vs flac, or in phono stylus.  But none when it comes to cables, DACs or the tubes I got from the recommendations on the first couple of pages of this thread.  I agree it is fun trying out the different tubes, just wish it were more apparent.  I will hand it to you guys for being able to do it.  Has anyone had a buddy change the tubes for you (blind test) and had you tell which ones they put in?  Might be fun to see what happens.
> [/QUOTE


 i guess its never been that important for most of us to be very critical about the tubes we tried its just a hobby and when you like your hobby its going to cost you mony some more than others lol.


----------



## mordy

dtbach said:


> I’ve had my little dot now for a couple of months and have tried mullards, voshkods, tung sol, GE, and others.  I can’t tell any difference between any of them.  The main reason is that there is no way to do good A/B comparisons.  By the time you let the first tubes cool down, take them out, put different ones in, power on, let warm up you have at least 5-10 minutes of elapsed time.  A/B comparisons need to b done in less than.2 seconds to be reliable.  Have fun with tube rolling, I’ll spend my money on headphones.


Hi dtb,
You are lucky that all tubes sound the same to you - don't need to spend money on finding the best sounding ones, which for most of us doing it, is never ending....
I have come across other people saying the same thing - all tubes sound the same, so you are not alone. Regarding myself I can hear differences, but I have found long term listening more beneficial than A/Bing, especially if the differences (to me) are subtle. 
A tube combination can sound great to begin with, but over time there could be a grating feeling that something isn't just right. Sometimes I can put my finger on it and describe to myself what I perceive is wrong (treble too bright as an example or voices don't sound natural) and sometimes it is just an uncomfortable feeling after prolonged listening. 
It also takes me time to appreciate or dislike a tube. Some people claim that they can listen for a couple of minutes and already know how it sounds, but I can't do that.
However, since you say that you want to spend money on headphones it maybe means that different headphones sound different to you.
One thing that sets apart tubes/headphones is bass. It seems to me that if you play a familiar piece with strong bass presence you should be able to hear differences with different equipment. How are the lowest frequencies reproduced? How are dynamics, attack, slam?
It is also worth mentioning that tubes need burn in to sound their best. Usually  30-50 hours is enough, but some tubes require much more, f. ex. the Voskhods need upwards of 120 hours.


----------



## dtbach

Fair enough.  I really haven't put the hours on any of these tubes so will let them burn in more.  I have some different power tubes coming so will try them in combination with the drivers.  The one set of tubes I feel have a nice sound for me are the Tung Sol.  When I played Simon and Garfunkel "Only living boy in New York" it was magical with them.  My first tube amp was the Schiit Vali 1 which is a great little amp, but nothing compared to the Little Dot.  I'm in love with it and love the tube sound.


----------



## triod750

I don't mind having my experiences challenged. They are all in my head since we hear with our brains and remember with our brains. Everyones experience is unique. 
I bought my Little Dot second hand with a whole assortment of input tubes. Even if I sometimes could hear a slight difference in sound between them none of them helped me in my quest for the natural tone of acoustical instruments that I have appreciated since my early childhood. Thus I share the experience of not being able to hear significant differences between different tubes.

If I had to compare and choose tubes listening to rock music or other 'electrical music' I would have extreme difficulties because of lack of reference how it should sound. The only question I might be able to answer would be 'do I like how this sounds'? Myself, I mostly listen to acoustical music ever since I was about four years old. Acoustical instruments, especially string instruments, are instrumental for me to enjoy my music. How my audio equipment can reproduce that is what dictates my decisions. I listen to other music as well but I rarely get that 'grating feeling' Mordy speaks of doing this, that something 'isn't right' because I don't know how it is supposed to sound. I can get listening fatigue because of a bad production; oh yes, but that is something else. When string instruments, and other instruments that I have a mental picture of, don't sound right to me, well, it isn't music to me - it is sound. I can't enjoy it.

But I am talking of synergy. Your headphones are a vital part of that, and your source, and yourself and your mood. Everything works together to give you your musical experience. Or not.

I like to experiment with tubes to find those who have the best synergy with the rest of my chain to give me my music in a way I can appreciate. I don't expect anyone to follow suit, making the same decisions I have made or coming to the same conclusions. On the contrary, trust your ears and find your own way to enjoy your music.


----------



## TrollDragon

Exactly! It's all about the joy of rolling tubes and finding out what sounds great for you.


----------



## TrollDragon

dtbach said:


> I’ve had my little dot now for a couple of months and have tried mullards, voshkods, tung sol, GE, and others.  I can’t tell any difference between any of them.  The main reason is that there is no way to do good A/B comparisons.  By the time you let the first tubes cool down, take them out, put different ones in, power on, let warm up you have at least 5-10 minutes of elapsed time.  A/B comparisons need to b done in less than.2 seconds to be reliable.  Have fun with tube rolling, I’ll spend my money on headphones.


You could pick up a silicon tube puller from PS audio to remove the tubes while they are hot, but any thick piece of silicon would work. 
https://www.psaudio.com/products/tube-puller/#tab-description


----------



## triod750

The reason for me to try other tubes than those included when I bought my pre-owned Dotty was that I didn't like the way those tubes presented the music. Especially some Mullard input tubes in combination with Electro Harmonix (?) 6N30P made the music sound 'beautified' and brittle in comparison to how the instruments sound live. A violin, for example, can be very harsh sometimes and aggressive. I don't want my amp to polish this.

I don't do A/B comparisons. But if our memory is so short as stated, our amps should sound differently all the time. Every time you turn it on it is new. And how can we recognize voices on the phone? (To be honest, I don't trust my memory anymore. Neither does my wife).

I dont compare tubes, I try to hear if the piano sounds right, or other instruments and voices. Right now I listen to Grayson Capps; 'If you knew my mind'. (His wife Trina Shoemaker got a Grammy award as audio engineer, but not for that record). It sounds good but I don't know if it sounds right. And I don't care, as long as I can enjoy it. When trying to find a tube combination that works to my liking (yes, you could say that I compare tubes) I listen to a few well known tunes many times. When I like what I hear, I listen to other tunes and recordings to 'see' if they sound good too. Often they do, but not always.

My conclusion is: var och en blir salig på sin fason!


----------



## mordy

TrollDragon said:


> You could pick up a silicon tube puller from PS audio to remove the tubes while they are hot, but any thick piece of silicon would work.
> https://www.psaudio.com/products/tube-puller/#tab-description


Here is an inexpensive solution from any stationary store - rubber finger grips. Size XL works well for 9pin tubes.


----------



## mordy

triod750 said:


> The reason for me to try other tubes than those included when I bought my pre-owned Dotty was that I didn't like the way those tubes presented the music. Especially some Mullard input tubes in combination with Electro Harmonix (?) 6N30P made the music sound 'beautified' and brittle in comparison to how the instruments sound live. A violin, for example, can be very harsh sometimes and aggressive. I don't want my amp to polish this.
> 
> I don't do A/B comparisons. But if our memory is so short as stated, our amps should sound differently all the time. Every time you turn it on it is new. And how can we recognize voices on the phone? (To be honest, I don't trust my memory anymore. Neither does my wife).
> 
> ...


Here is the translation from Swahili:

_Var och en blir salig på sin fason! _  Everyone gets blissful in their own way!


----------



## marusanek52 (Feb 5, 2021)

Hey guys, I picked up the LD MkII and a few days ago and love them, but as I've read it can be improved with better tubes. I use it with hd650s, what should I start with? Can tube selection help make them a little brighter (or lift the "veil") and widen the soundstage? Would the JAN5654W be a good choice?


----------



## RockstarRmgddn (Feb 5, 2021)

@marusanek52 They seem like a good pair of tubes. I'm thinking of buying a pair myself.

So guys I'm in the same boat as the guy above. I've recently bought a Little Dot MK II second hand to pair with my HD600. The guy I got them from gave me a decent number of tubes along with the unit and recommended to use them with the mullard 8161. Now thing is, while they sound good with the mullard I've tried the 6ZH1P-EV and they sound much better with that. Better bass, better mids, more holographic soundstage. Apart from one fact. The highs make them unbearable. I've heard the  6ZH1P-EV need burn-in, mine are basically unused. You guys have any experience if the highs mellow out a little after burn-in?

I also have some 6J1P-EV I haven't tried yet.


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## MIKELAP (Feb 5, 2021)

marusanek52 said:


> Hey guys, I picked up the LD MkII and a few days ago and love them, but as I've read it can be improved with better tubes. I use it with hd650s, what should I start with? Can tube selection help make them a little brighter (or lift the "veil") and widen the soundstage? Would the JAN5654W be a good choice?


I would try Electro harmonix 6H30Pi as power tubes and a pair of Russian Voskhod 6ZHiP-EV should clear things up .


----------



## mothbhai

Hi I recently got a Little Dot MkII and this guide has been super helpful. I can't say that I have read all 835 pages, but have scanned a few. I replaced my stock driver tubes with the GE JAN 5654W and the Voshkod 6ZH1P-EV. To my ears, the GEs have sounded a lot more engaging, airy and easy to listen. The Voshkods sounded a bit recessed, with the mids and highs slightly muddy, but with stronger bass. I got the GE ones from Riverstone Audio via Amazon and the Voshkods from ebay here. I am wondering I got the right Voshkods. These have the rocket logo, so from the Voshkod factory. Labled OTK1, and have the numbers 11-80 under the EB - indicating that these are from Nov 1980 - which should be during the good years still. I have run them in for about 48 hours so far - some say 100+ is needed, so will run some more. Any advice would be great. Given how many people say the Voshkods are fantastic, I am wondering if I am missing something. Meanwhile enjoying the GE JANs a LOT!


----------



## marusanek52

MIKELAP said:


> I would try Electro harmonix 6H30Pi as power tubes and a pair of Russian Voskhod 6ZHiP-EV should clear things up .


Thanks for the response, I think I'm going to try the Voskhods. Do you think this is a good listing? https://www.ebay.com/itm/1-x-Matche...sh=item2afc748411:g:BRAAAOSwJ6xgAzW8#viTabs_0
It's really close to where I live, but they don't seem to have the rocket logo, do the different versions have different sounds?


----------



## MIKELAP

marusanek52 said:


> Thanks for the response, I think I'm going to try the Voskhods. Do you think this is a good listing? https://www.ebay.com/itm/1-x-Matche...sh=item2afc748411:g:BRAAAOSwJ6xgAzW8#viTabs_0
> It's really close to where I live, but they don't seem to have the rocket logo, do the different versions have different sounds?


.If the tubes are tested and seller has good ratings go for it .Remember they dont need to be matched pairs so dont pay extra for this . As for any difference in sound i wouldnt know about the rocket branded 6ZHiP-EV i know the ones i had  to me  sounded very clean but again like Gibosi would say My ears and my gear lol .You have to try to see .


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## RockstarRmgddn (Feb 10, 2021)

Ok, I found a quick fix for Voskhods 6ZH1P-EV / 6J1P-EV if you find the cymbals too loud like I did. It's called APO Equalizer. Just google it. It will work on all sounds from within windows on the selected output source. Turn off example.txt filter - it's an extended bass boost and not needed. On the right the values  -2 for 16khz and -1 for 10khz worked for me. The sound is now pretty much perfect.


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## MIKELAP

RockstarRmgddn said:


> Ok, I found a quick fix for Voskhods 6ZH1P-EV / 6J1P-EV if you find the cymbals too loud like I did. It's called APO Equalizer. Just google it. It will work on all sounds from within windows on the selected output source. Turn off example.txt filter - it's an extended bass boost and not needed. On the right the values  -2 for 16khz and -1 for 10khz worked for me. The sound is now pretty much perfect.


I use APO and PEACE together to adjust my gaming mic nice programs or i also have a 15 band equalizer with MUSICBEE the music player .


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## lupoal (Feb 28, 2021)

hi,

so I decided to build C3G to 6AK5 adapter by myself but... I've lost (again! ) the page with that fantastic diy guide (I mean that one starting with the pin production and then step by step to the final perfect result) to follow/get suggestions

in the last hour I'm searching this thread with all the keywords I can immagine without success ... ... could anybody help me?

edit ... page 553! yeah! (now I saved the address as "C3G to 6AK5 DIY adapter"... so I will find it also in the future  )


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## MIKELAP

This will help


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## lupoal (Feb 28, 2021)

Thanks a lot Mike...
now I’ve some doubts about pin out ... I’ve read at page 544 and the pin out doesn’t fit to what I’ve found using my tester inside the broken adapter in my hand... here is the picture of the adapter (inside)






this is the pin out

5654      C3G
1.           6
2 / 7.     2 / 7
3.          8
4.          1
5.          3
6.          4
7 / 2.     7 / 2

I’m confused


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## MIKELAP

lupoal said:


> Thanks a lot Mike...
> now I’ve some doubts about pin out ... I’ve read at page 544 and the pin out doesn’t fit to what I’ve found using my tester inside the broken adapter in my hand... here is the picture of the adapter (inside)
> 
> 
> ...


This is the diagram i used page 553 post 8295


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## MIKELAP (Feb 28, 2021)

MIKELAP said:


> This is the diagram i used page 553 post 8295


My schematic has pin 7 to pin 1. Heater pin 1 and 8


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## lupoal (Mar 1, 2021)

ok, does it mean that there are many possible different ways to connect pins (sound quite strange) or that those schematic connections name pins in diffent ways or the adapter from China in my hands is wrong or... ?

so I've checked again ad the pin #5 at C3G is not connected to anything in the adapter but just lived floating (the adapetr is the in-famous one you all know from ebay)... that adapter is terrible ... I will do mine following your scheme


----------



## MIKELAP

lupoal said:


> ok, does it mean that there are many possible different ways to connect pins (sound quite strange) or that those schematic connections name pins in diffent ways or the adapter from China in my hands is wrong or... ?
> 
> so I've checked again ad the pin #5 at C3G is not connected to anything in the adapter but just lived floating (the adapetr is the in-famous one you all know from ebay)... that adapter is terrible ... I will do mine following your scheme


Look closely at the pictures you cant go wrong pins are reversed


----------



## Shane D

TrollDragon said:


> Power cables...   I suppose magic fuses will be next...


Are the 6HM5's your "go-to" tubes? I have an LD MKIII on its way to me and it has three sets of driver tubes:
2 X 6HM5 Yugoslavia
2 X Voshkad 6ZHIP-EV
2 X RTC 5654

I have already been looking at others, but I know that I just need to calm down, wait and try these out first.


----------



## TrollDragon

Shane D said:


> Are the 6HM5's your "go-to" tubes? I have an LD MKIII on its way to me and it has three sets of driver tubes:
> 2 X 6HM5 Yugoslavia
> 2 X Voshkad 6ZHIP-EV
> 2 X RTC 5654
> ...


I've had the Yugoslavian 6HM5s in my MKIV for the past 5+ years and have been my goto tubes.  I have a pair of C3g but still have not had a chance to remove the tube cage from the MKIV and plug them in yet, I know they will be amazing and most likely replace the 6HM5.

I've rolled a tube or two in my MKIV.


----------



## Shane D

TrollDragon said:


> I've had the Yugoslavian 6HM5s in my MKIV for the past 5+ years and have been my goto tubes.  I have a pair of C3g but still have not had a chance to remove the tube cage from the MKIV and plug them in yet, I know they will be amazing and most likely replace the 6HM5.
> 
> I've rolled a tube or two in my MKIV.


Wow!


----------



## lupoal (Mar 9, 2021)

after a bad experience with two chinese adapters with serious quality problems (and engineering problems that are defective already in design), that gave me a strong "hummmm" with the C3G, I decided to make myself a pair.
I disassembled this crap...





and then using cyanacrylate adhesive, to hold the pins in place in the pin-saver that sometimes comes with valves, and successivalent two-component epoxy resin, to lock everything in place and ensure electrical isolation, I assembled my adapters starting from a commercial bulb holder (cost 1 euro each).
The two conductors that carry the 6.3Vac are twisted and shielded, the shield is connected to the center pin of the valve, so the aluminum valve housing acts as an effective shield at his best, the shielding braid then crosses the mechanics and is connected to an external copper shielding, this is also connected a connector to connect shielding-circuit then this to earth through an independent cable (so not the ground conductor of the power cable and not even the shield of the power cable).









the piece of screw you can see in the middle is there to increase the coupling/holding force of cyanacrylate between plastic parts



















The result of the work could be aesthetically better but from an electrical point of view is perfect .... no HUMMM even with maximum volume and in the absence of musical content. Very silent!

last but not least... thank you MIKELAP for precious help!


----------



## carloc

Congrats Lupoal!

Well done!


----------



## triod750

This is cheating, Luopal!! 

I am very confused if your original adapters came from 'xulingmrs'. I bought mine from her a few years ago and they have been working perfectly. I have never had any trouble and my Little Dot has always been dead quiet (except from the music) when using them. My adapters from 6N6P to 6SN7 etc come from the same source and has that same quality. Since they are working well I will not butcher them to check their innards.

I am impressed by your solution!


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## lupoal (Mar 9, 2021)

Yes they are the original Chinese stuff..... I’ve no idea, maybe I’ve been a little unlucky but, in any case, from mechanical point of view those adapters  are pure rubbish... so use them gently, very gently

now talking about tubes...  those C3G... what is the best match with them? RCA... Tungsol... Sylvania... ? now are playing with couple of 6H8C from year 52 and the sound is not as wide as expected... also in the low register the sound a little too dry...the same 6H8C with 6BE6 from RCA or Brimar sound completely different, with Brimar good low register but also fast and punchy, with RCA the bass go even deeper but a little bit slower, warmer... with both head stage is wider and deep and with more air between instruments, compare with C3G clearly... so suggestions about C3G matching?


----------



## triod750

It took quite some time before my C3g sounded any good. Don't remember how long but I was sceptical for a long while. But I have that same experience from my main tube amps for loudspeakers so I had patience. Still I sometimes jump to conclusions when trying new tubes. I only have Melz made 6H8C and they don't work that well with C3g to my ears. The combination is too much of a good thing. Both are very resolving tubes and together they tend to give much detail and less 'body'. I'm speaking of Siemens made C3g here. They are the only C3g I have experience of. So I'm only telling of my experience of this combination, my ears and my gear and mostly acoustical music. Resolving is good for my music but I'm looking for better balance to find the all important 'tone' I am searching for.

(We cannot be speaking of the same adapters since my adapters are very robust mechanically).


----------



## MIKELAP

Most of my adapters were made by that seller and a few others . In general they work good .i try to buy adapters that use the CMC  sockets ,better quality .


----------



## lupoal (Mar 10, 2021)

@triod750
you got the point... almost (  )... as my C3G are not new (the dealers declared they are still good, but as I remember the condition of the pins of those tubes I have some doubts they tested them) I think burn-in should not be required

my 6H8C are from Foton but have the same behaviour as yours Melz... togheter with Siemens C3G (mine are Siemns too) I have the same feeling there is not enough body... I will try today with a couple of 6SN7GTB RCA


----------



## triod750

There should be a lot of hours between burn-in and burnt-out. If you are comfortable with being adventurous you could go for external psu for the heaters and try 6BX7GT. They will give you a lot of body. I haven't tried RCA 6SN7GTB but a few others in that family, such as Ken-Rad 6SN7GTA, Brimar 6SN7GT, Sylvania 6SN7GTW, RCA 6SN7GT and a single Raytheon 6SN7GT tall bottle and a single Sylvania VT231 and maybe som I have forgotten.

I enjoy the ride and am looking for 'the right tone' but would not mind finding it. Even if I find it I am convinced that I will keep on experimenting for the fun of it. Right now I am listening to a choir work by Arvo Pärt, using EL42 as input via adapters from @Deyan  and Melz 6H12C as output via adapters from xulingmrs. No external heater psu used for this. The music is beautiful!


----------



## lupoal

Ok, with RCA those C3G are much much much (not a typing error) better... let say still a little on the bright side especially with the piano, but that could also be matter of recording... this is the album (Qobuz) I’m using for test, very nice live session





now... I would like to investigate the possibility of 6AS7G/6080 with external power supply togheter with C3G... is it so good as declared here ?


----------



## triod750

I have just tried 6080 (Tung-Sol and Tung-Sol Chatham) shortly and also -62 Svetlana 6N13S shortly and wasn't impressed enough to take it any further there and then. Maybe I will revisit, I don't know. Two GEC A2293 single triodes (one A2293 is the equivalent of one half 6AS7G) per channel seems more promising to me. But sound and tone and presentation is a very personal thing and very little science when it comes to comparisons. I have to admit that I haven't tried 6080/6AS7G with EL42. Maybe they work better together?
In my opinion, 6BX7GT is a better alternative in Little Dot. Same psu and same adapters. A lot less heat to the components. Enough power (for my HD650).


----------



## cddc (Mar 10, 2021)

lupoal said:


> after a bad experience with two chinese adapters with serious quality problems (and engineering problems that are defective already in design), that gave me a strong "hummmm" with the C3G, I decided to make myself a pair.
> I disassembled this crap...
> 
> 
> ...




Nice workmanship, very handy man!

I like the way you ground the adapters.

Where did you find the base and pins for the miniature 7-pin socket? Are the 8 holes in the base spaced out exactly as the miniature 7-pin socket, and you just simply glued the pins to the base?


----------



## TrollDragon

Nice to see the modding active again in this thread. I remember the old days when we were trying dual triodes.

My Mk IV with a 6SL7GT in a DIY adapter.


----------



## lupoal

triod750 said:


> ...
> In my opinion, 6BX7GT is a better alternative in Little Dot. Same psu and same adapters. A lot less heat to the components. Enough power (for my HD650).



I’m using the same headphone... I will investigate about 6BX7GT, I don’t know anything about this... ok, let’s start searching info


----------



## lupoal (Mar 11, 2021)

cddc said:


> Nice workmanship, very handy man!
> 
> I like the way you ground the adapters.
> 
> Where did you find the base and pins for the miniature 7-pin socket? Are the 8 holes in the base spaced out exactly as the miniature 7-pin socket, and you just simply glued the pins to the base?



thank you 

the base if one of those pin saver (hope is the right way to call them, I’m not sure as I’m Italian ) you get sometimes together with tubes... I received two of them with the last couple of  Brimar 6BE6 I bought... so the pin position is already perfect... you should be able to find them also in eBay 

the pins are from the Chinese adapter I cannibalized, same source for the octal socket... yes, first I glued the pins, already soldered to wires, with cyanacrylate... you have to use the gel one otherwise is too much thin and fluid and unable to fill the gap between pins and holder... after that you assemble the pin holder to the housing with some epoxy glue, at this stage I suggest to protect the pins with some paper tape... once the epoxy hardened then, if you use roughly the same housing I’ve used, you can inject additional/higher quantity of epoxy from inside and between wires using a syringe without needle


----------



## cddc

lupoal said:


> Ok, with RCA those C3G are much much much (not a typing error) better... let say still a little on the bright side especially with the piano, but that could also be matter of recording... this is the album (Qobuz) I’m using for test, very nice live session
> 
> 
> 
> now... I would like to investigate the possibility of 6AS7G/6080 with external power supply togheter with C3G... is it so good as declared here ?



Thanks a lot for explaining where you got the bases, they are from pin protectors/savers, that explains why they match so well with the miniature 7-pin socket.  I was thinking it's a miracle to find some rubber base that happened to have 7 holes matching exactly with the 7-pin socket.

My experience with Melz 6H8C tubes matches yours and @triod750's , they have clean & detailed sounding but a little bit lean to my taste, I guess that could be the "house sound" of Melz, so Melz 6H12C could have the same signature.

If you like the warmth from RCA 6SN7GTB, you can possibly try the RCA 6SN7GT grey glass or VT-231, they come with the RCA warmth but with better resolution than the RCA GTB's.

If you can run 6080/6AS7 tubes with external heaters, I think you will get much more power from them. Worth a try in my opinion.


----------



## triod750

I would not suggest that you try either 6080/6AS7G or 6BX7GT. Try both. Same external psu, same adapters. But I am sure that 6BX7GT and 6BL7GT are much kinder to the components in Little Dot. @mordy used a computer fan to evacuate hot air from the tubes, not to overheat the amp. I don't believe 6BX/BL7 runs any hotter than 6N6P but 6080 makes the amp very hot. (The adapters and heater input adapters elevate the 6BX7 tubes from the chassis so they don't transmit as much heat to the chassis as 6N6P does. This goes for 6BX7 but 6080/6AS7 produces so much more heat that the distance isn't enough). But if they are good for the music, your phones and your ears....

If you don't try it you will never know. But HD650 don't need as much power as some other phones.


----------



## lupoal

well... heat and capacitors are declared enemy, I'm happy that with 6SN7 the LDII remain quite cold compare to the use wth 6N6P so 6BX7GT are more reassuring to me ... but before to proceed one question (maybe stupid): from 6SN7, or 7n7 with adapter (cheap and very good), to 6BX7GT is the gap in performance worth the efforts? or is mainly matter of fun in doing that (that is also important)?
I'm also wondering if, at this stage, is now better to put attention in, maybe, changing output capacitors... but this is argument for different thread


----------



## triod750

If rock music was my main preference I would definitely go for 6BX7 for more powerful presentation than 6SN7. To me, the difference isn't subtle. And 6BX7 is cheaper than 6SN7 that sound good. 6BX7 give a lot more 'body' than 6N6P and 6SN7 in my opinion.

Acoustical music is my preference but I still like 6BX7. To my ears, the 6080/6AS7 had no advantage but I have only tried three different; used Tung-Sol and Tung-Sol Chatham 6080 and NOS Svetlana 6N13S (6AS7G). They were kind of 'syrupy'. Maybe I didn't give them enough time. A2293 could be said to belong to that family and I will give them more time to shine since they seem more promising in my amp. They are NOS with not many hours in adapters from @Deyan. The 6080 tubes were used and I don't know how much life they have left so the comparison isn't fair. But I won't look for NOS since I don't think I need them. Yet.

The reason for me to choose GEC A2293 was that a lot of people seem to regard GEC 6080 and GEC 6AS7G as very good, or better, and thus they are very expensive. I was hoping that two GEC A2293 per channel would give me some of that flavour to a lower cost.

As always, you can't discuss input or output tubes separately. You have to create the right synergy for your own ears. I don't claim or say that you should do this or that, only what you could do. It's too early for me to say how I like these A2293 since I am going to give my EL42 input and Melz 6N12S output a lot of time in my amp to be able to evaluate the combination.

Photo of adapter for A2293 below. And I can say that A2293 are very powerful!


----------



## lupoal

sorry for the stupid question of the day... just a doubt before to buy a couple of C3G as spare parts tube... with LDII those C3G are used as pentode or as triode?


----------



## gibosi

lupoal said:


> sorry for the stupid question of the day... just a doubt before to buy a couple of C3G as spare parts tube... with LDII those C3G are used as pentode or as triode?


In the LD, these are configured as triodes, grid 2 strapped to the anode and grid 3 strapped to the cathode.

https://frank.pocnet.net/sheets/190/c/C3g.pdf


----------



## lupoal

Ok thks... but is it correct that as triode they are just average and as pentode as fantastic? I mean... a couple NOS (I mean real new) cost roughly 120 -140 euros... used as triode is the price justified?


----------



## gibosi (Mar 15, 2021)

lupoal said:


> Ok thks... but is it correct that as triode they are just average and as pentode as fantastic? I mean... a couple NOS (I mean real new) cost roughly 120 -140 euros... used as triode is the price justified?



In audio the C3g is almost always configured as a triode. In fact, I am personally not aware of a single instance when it has been used as a pentode in a audio amplifier. But then I am not an audio engineer.

I think there are a couple things to keep in mind. Low distortion and high linearity do not guarantee good sound. In fact, solid state devices measure much better than tubes, "fantastic," but still, many people believe tubes sound better. And among tubes, the E80CC, a double triode, sometimes called a "super 12AU7", rivals the C3g when configured as a pentode. But many are not all the impressed with the E80CC.

Further, tubes are thought to sound better than solid state because of the nature of their distortion. The distortion in tubes is mostly even-order harmonic distortion whereas solid state is mostly odd-order. Many consider even-order to sound more musical and odd-order to sound more harsh.

So in the end, what one is doing is choosing tubes which have the best "musical" distortion. lol 

Anyway, I would urge you to not worry about the comparative distortion, pentode versus triode-strapped. Rather consider that most designers, if not all, use the C3g as a triode-strapped pentode. And finally, trust your ears. 

edit: fixed a couple errors.


----------



## Shane D

I also asked this in the amp thread, but I am curious about what headphones the veteran tube rollers have landed on for the LD MKIII?

I have HD660's, DT880's (600 Ohm) and HD6XX's on the way.


----------



## triod750

I use Sennheiser HD-650, not because they are best but since that was what I already had. I bought them used with a Zu Mobius aftermarket cable and find that they respond well to better tubes. Or.....they clearly 'show' differences. Some find them boring. I mostly listen to acoustical music. I don't know what would do me most good; a 'better' amp or 'better' headphones.


----------



## Benno1988

Litte dot maniacs.

For low imepdance cans, which is the best model? MK IV SE or MK9 or another? Looking for something for light use with MDR-Z1R and Meze Empyrean.


----------



## TrollDragon

Shane D said:


> I also asked this in the amp thread, but I am curious about what headphones the veteran tube rollers have landed on for the LD MKIII?
> 
> I have HD660's, DT880's (600 Ohm) and HD6XX's on the way.


I only run high Z headphones on my MKIV, DT880 (250Ω)  and the GMP8.300D Pro (300Ω). I heard the HD6xx on a THX amp and wasn't really impressed with them, I should try them again on the OTL amp as everyone claims it is a better pairing.  Would love to get my hands on a pair of DT150 (250Ω) and the GMP400 (300Ω) as I like the German Maestro house sound.

If Ultrasone made high Z headphones there would be a pair of those in the stable as well.


----------



## TrollDragon

Benno1988 said:


> Litte dot maniacs.
> 
> For low imepdance cans, which is the best model? MK IV SE or MK9 or another? Looking for something for light use with MDR-Z1R and Meze Empyrean.


Definately not the MK IV SE as it is an OTL tube amp designed for high Z headphones, same with the OCL MK 9. OTL cannot provide the current that low Z headphones require, and due to the high output impedance of those amps you will experience bass roll off.

For your headphones a better choice would be to look into OTC (Output Transformer Coupled) amplifiers like the Woo WA6SE, Cayin HA-1A MK2 or similar, the quality output transformers add greatly to the cost of these amplifiers.  

If you are not looking to go full tube, then a cheaper Hybrid tube amplifier (tube driver/solid state output) would be a better choice but the sound will still be mostly solid state.


----------



## dtbach

Shane D said:


> I also asked this in the amp thread, but I am curious about what headphones the veteran tube rollers have landed on for the LD MKIII?
> 
> I have HD660's, DT880's (600 Ohm) and HD6XX's on the way.


I enjoy my HD6XX and Beyer DT-990 with my little dot the best.  My AKG712 Pro and HE-560 like solid state better.


----------



## Benno1988

Thanks guys!

Will keep hunting then.

I had a Cayin and a mate had two Cayins and they all died early lifes. So not sure I'm keen to go back there.


----------



## Shane D

My first day of tube rolling with my LD MKIII. I started with the Yugoslavia tubes and it was great at first. Then when I turned the unit of and on a few times the left side got and then even cut out.

Gave it 90 minutes to drain capacitors or whatever. No improvement.

I reversed the power tubes and put it in the 5654 tubes. Dead quiet, but the sound seemed kind of small.

Then I put in the Voshkods and now it is sounding great. I am running Beyer DT880's (600 Ohm) and they take every bit of power this little amp can put out.


----------



## TrollDragon

Shane D said:


> My first day of tube rolling with my LD MKIII. I started with the Yugoslavia tubes and it was great at first. Then when I turned the unit of and on a few times the left side got and then even cut out.
> 
> Gave it 90 minutes to drain capacitors or whatever. No improvement.
> 
> ...


I'd suggest cleaning the pins on the Yugoslavian tubes as well as any other tube that gives you noise or cuts out.  I clean the pins of every new to me tube before use.


----------



## Shane D

TrollDragon said:


> I'd suggest cleaning the pins on the Yugoslavian tubes as well as any other tube that gives you noise or cuts out.  I clean the pins of every new to me tube before use.


Do you use de-oxit? Now that I have three tube amps I should probably splurge on a can.


----------



## Shane D

On my first day with my MKIII, I was getting noise out of my 6HM5 Yugoslavia tubes. When.i was talking to the seller, he mentioned that they were new to him and he hadn't tried them.
So I decided to run them last night while watching TV. Maybe they just needed breaking in. After a few hours of being on, with all four tubes in and no mysic playing I started to hear noises. It was like a hiss and  a crackling. It seemed to be coming from the power bar and not the amp. As soon as I  turned the amp off, it was gone. Bad tubes? Lustening today with the Voshkods in and it sounds great.

Are these defective tubes? Could they be the wrong tubes?
Pics:


----------



## triod750

I carefully clean the pins on all tubes - new or used - before I use them. Before I made this a habit I once had the same problem as you describe. Other people have described the same problem and solution. I use fine emery board. Some use a dull small knife. I then use contact spray on a 'cotton pin'. 'PRF 6-68' is a contact spray for electronics that leaves no residue. There must be plenty of others that work as well.

Your tubes look the same as mine.


----------



## TrollDragon (Mar 20, 2021)

Shane D said:


> Do you use de-oxit? Now that I have three tube amps I should probably splurge on a can.


I've never used Deoxit but do have a can of LPS Contact cleaner around to clean electronics.

I clean the pins of tubes with a Dremel 4mm bullet point polishing burr, it makes fast work of cleaning pins.




I'd definitely give those pins a good cleaning either with a similar Dremel bit, an emery board like Triod750 mentioned, a strip of fine emery cloth or something.


----------



## TrollDragon

It's really too bad that thousands of pictures from this thread and others were lost when they changed forum software...


----------



## Shane D

TrollDragon said:


> It's really too bad that thousands of pictures from this thread and others were lost when they changed forum software...


I noticed that when I was researching. Too bad.


----------



## Jolterrrr

Hello 

I am new to tube Rolling 😊  can i use 6AS7G's power tubes in My Ld mk2? Or is it only for mk3? (With that strange cut pin thing) 🤔??


----------



## lupoal (Mar 21, 2021)

@Shane D
... if you don't have Deoxid then just put them inside Coca Cola... don't leave them inside too long (start with a couple of hours and then inspect them with magnifier... the app Lente d'ingrandimento for android works really well) otherwise you loose your pins, then whasm them with warm water and then, if you like, the pins with a toohbrush and some alcool


----------



## TrollDragon

Jolterrrr said:


> Hello
> 
> I am new to tube Rolling 😊  can i use 6AS7G's power tubes in My Ld mk2? Or is it only for mk3? (With that strange cut pin thing) 🤔??


6AS7G draw 2.5A each on the heaters, you must use an external heater power supply to use them in your MK II.


----------



## Jolterrrr

mordy said:


> http://www.ebay.com/itm/NEW-DC-DC-S...037?pt=LH_DefaultDomain_0&hash=item3a901724dd
> 
> http://www.ebay.com/itm/1pc-6SN7-6SL7-TO-12AU7





TrollDragon said:


> 6AS7G draw 2.5A each on the heaters, you must use an external heater power suppl





TrollDragon said:


> 6AS7G draw 2.5A each on the heaters, you must use an external heater power supply to use them in your MK II.


Aha! Can i use this device ??? 

https://www.ebay.com/itm/XL4015-5A-...-/132816365155?_trksid=p2349624.m46890.l49292

And to what pins do i solder ? 4 and 5 ? 😊


----------



## Jolterrrr

TrollDragon said:


> 6AS7G draw 2.5A each on the heaters, you must use an external heater power supply to use them in your MK II.


And what adapter/s is it enough to buy 2 of these 6SN7-6SL7-TO-12AU7? Cut pin 4-5 and solder Them to an external heater? It Will fit in My mk2 ?


----------



## TrollDragon

Jolterrrr said:


> Aha! Can i use this device ???
> 
> https://www.ebay.com/itm/XL4015-5A-...-/132816365155?_trksid=p2349624.m46890.l49292
> 
> And to what pins do i solder ? 4 and 5 ? 😊


Too bad all the old information (pictures) on this mod was lost when Head-Fi updated the forum software.

You will need a pair of adapters to convert the 6AS7G tubs to 6CG7 compatible pinout.
https://www.ebay.com/itm/1PC-Tube-D...O-6CG7-for-Vacuum-tube-amplifier/303542012598

A pair of B9G socket savers so you can cut off pins 4 & 5 and attach the external power supply wires.
https://www.ebay.com/itm/NEW-9-PIN-...7-5751-12AT7-etc-FAST-USA-SELLER/254612574139

Finally I'd go with at least a 8A DC converter as the one you linked has a maximum output rating of 5A and will require cooling if you are running both tubes from it. If you use one for each tube that would be better and probably not require cooling.  You will also need a decent power supply to provide enough source power for the DC converter board, a lot of the members here used old laptop power supplies.

Note that this will make your MKII run hotter, the biasing of the circuit is all wrong since the amp was never designed to run those tubes.

I've never bothered to play with any octal tubes as outputs, many others have and YMMV with results.


----------



## Jolterrrr

TrollDragon said:


> Too bad all the old information (pictures) on this mod was lost when Head-Fi updated the forum software.
> 
> You will need a pair of adapters to convert the 6AS7G tubs to 6CG7 compatible pinout.
> https://www.ebay.com/itm/1PC-Tube-D...O-6CG7-for-Vacuum-tube-amplifier/303542012598
> ...


Thank you soo much ! 👍😃


----------



## triod750

Jolterrrr said:


> Thank you soo much ! 👍😃


Jag har skickat ett PM på ditt eget språk .


----------



## lupoal

.... just received my new couple of C3g NOS NIB, comparing with the others I have there are some small differences... here are some pictures, as you can see there are mechanical diffences in pins shape... the total tube length.... and others... what do you think  about?


----------



## gibosi

lupoal said:


> .... just received my new couple of C3g NOS NIB, comparing with the others I have there are some small differences... here are some pictures, as you can see there are mechanical diffences in pins shape... the total tube length.... and others... what do you think  about?



Tubes made in the same factory at different times are often different due to new processes, new technologies, new materials and feedback from the field. So in my opinion, perfectly normal.


----------



## lupoal

yes... I’m listening them right now and can confirm they sound the same... just amazing!


----------



## triod750 (Mar 30, 2021)

Some more information about C3g:
https://www.radiomuseum.org/tubes/tube_c3g.html
https://www.radiomuseum.org/tubes/tube_c3g_newi.html
https://www.radiomuseum.org/tubes/tube_c3gs.html
https://www.radiomuseum.org/tubes/tube_c3g_old.html


----------



## lupoal

thank you triod750...
what I would like to do now is to load the ampli scheme into Spice and substitute the default tubes, 6N6P and 5654, with 6SN7GT and C3g just to check if the default working points are correct (roughly) for the new tubes too...
the problem is that Spice is a kind of nightmare... especially for a rookie like me


----------



## triod750

What would you do if you found out that the working points are far from perfect but it still sounds good? Would you trust your ears?

I hope you share what you find. It would be interesting to know.


----------



## lupoal (Mar 31, 2021)

if they will be close enough to be good enough I will not care... if they will be far then I could start thinking to diy LDII ( this ) with the same circuit layout but optimized components (that doesn't mean crazy expensive)

if I reach something I will share... I think will take time and i'm absolutely not sure I will be able to run a decent simulation... but it's an hobby so I can take it easy

... or I could built THIS


----------



## triod750

Ten years ago someone promised me to build that Heinrich Siemens C3g amp you linked to. For me. Haven't seen it yet. So I suggest that you build it and tell us how it compares to Little Dot. I know of another person who built it and was very satisfied with it. Unfortunately I haven't listened to it yet.
Even better would be if you built both. Yes. Build both!


----------



## lupoal

ahahahahah.... you make it so easy 

no problem, send me all components required and I will build both 

just kidding 

anyway... the fact that the Siemens one use only two tubes instead of the most common four/six give me some doubts about the expected life of C3g used in that way... mmmm


----------



## cottoff

Hi all, recently bought a Little Dot MK2 - just wondering has anyone used EI 6HM5's as power tubes? And if so how do they compare to Russian 6n6p?
For reference these are the 6Hm5's I'm interested in:
https://www.ebay.com.au/itm/6HM5-EC...m3a9e64ab1c:g:~fkAAOSw4DJYe-Ce&frcectupt=true

Thanks in advance.


----------



## triod750

cottoff said:


> Hi all, recently bought a Little Dot MK2 - just wondering has anyone used EI 6HM5's as power tubes? And if so how do they compare to Russian 6n6p?
> For reference these are the 6Hm5's I'm interested in:
> https://www.ebay.com.au/itm/6HM5-EC...m3a9e64ab1c:g:~fkAAOSw4DJYe-Ce&frcectupt=true
> 
> Thanks in advance.


The 6HM5 is used as input tubes in Little Dot. They are pentodes that become strapped as single triodes in the amp. 6N6P are dual triodes that are used as output tubes. 6HM5 have 7 pins and 6N6P has 9 pins. 6HM5 in the 'large bottle' you are linking to are considered good input tubes in Little Dot.


----------



## TrollDragon

cottoff said:


> Hi all, recently bought a Little Dot MK2 - just wondering has anyone used EI 6HM5's as power tubes? And if so how do they compare to Russian 6n6p?
> For reference these are the 6Hm5's I'm interested in:
> https://www.ebay.com.au/itm/6HM5-EC...m3a9e64ab1c:g:~fkAAOSw4DJYe-Ce&frcectupt=true
> 
> Thanks in advance.


Like triod750 said those are driver tubes only.

One of the best IMHO.


----------



## lupoal

triod750 said:


> Some more information about C3g:
> https://www.radiomuseum.org/tubes/tube_c3g.html
> https://www.radiomuseum.org/tubes/tube_c3g_newi.html
> https://www.radiomuseum.org/tubes/tube_c3gs.html
> https://www.radiomuseum.org/tubes/tube_c3g_old.html



so I took my part in the auction (ebay) and I won... these are the two tubes I'm waiting now




am I right when I say that they have the same pin-out as all the other I already have? (sr. nr. 150401 and 150407) ? ... that story about "old" "new" "last more common" is a little bit worringsome




with these I'm going to start the Siemens amp  (probably)


----------



## triod750

I checked a C3g lying right beside me and the number on that was 1162738. I have four more with slightly lower number but seem to remember that they all have 7 digits. I suppose we could call our tubes 'standard C3g', the one we normally speak of and use. Don't think you have to worry the least.

I wish you luck with your Siemens amp. I have a pair of Lorenz made C3g on their way to me. They would not be a proper choice in a Siemens amp  .


----------



## lupoal (Apr 3, 2021)

do you expect they will sound very different from Siemens labeled ?
here are some info/history about C3g... unfortunately many pictures are lost... click


----------



## triod750

lupoal said:


> do you expect they will sound very different from Siemens labeled ?
> here are some info/hystory about C3g... unfortunately many pictures are lost... click


I will let you know when I have them. I just wanted to try them. Previously in this thread @gibosi has written about C3g branding and that most of these later made tubes with shiny black cans and white silk screened text were actually all made by Siemens, even if they are branded Valvo, Telefunken, Lorenz or ITT. I don't know where to find it right now. Perhaps he might comment on this.


----------



## gibosi

triod750 said:


> I will let you know when I have them. I just wanted to try them. Previously in this thread @gibosi has written about C3g branding and that most of these later made tubes with shiny black cans and white silk screened text were actually all made by Siemens, even if they are branded Valvo, Telefunken, Lorenz or ITT. I don't know where to find it right now. Perhaps he might comment on this.



Yes to the best of my knowledge, all C3g with shiny black cans and white silk-screened text and logos were manufactured by Siemens, regardless of branding. If the tube has a flat-black can and embossed top, it was manufactured by the company indicated on the can. Again, to my knowledge, only Siemens, Telefunken and Lorenz manufactured this tube. And to my ears, the Siemens and Telefunken sound very similar, but the Lorenz is noticeably darker and warmer.


----------



## triod750

I have received my Lorenz made C3g in embossed flat black cans and am listening to them right now. I prefer the treble in them to the somewhat aggressive treble (in combination with some output tubes) in Siemens made C3g. I was very lucky and just paid EUR20 + shipping for the pair. I have been looking for them to and fro for a very long time. I have not wanted to pay the premium prices they usually go for. They sound clean and not lacking, to me. I agree with @gibosi's evaluation of them.


----------



## Itzi (Apr 17, 2021)

Hello! I've recently joined after lurking this thread for a while because I have some questions to ask about my Little Dot II. I've been enjoying it recently with Sylvania 6SN7 power tubes and Mullard EF92 driver tubes, and im loving this setup. I also have some Voshkod drivers coming in soon, excited to try those. However, I do have one issue.

When I was first setting up my LD, I was struggling to find out how to open it to change the internal dip switches, and I tried removing the front panel. This damaged the volume potentiometer, and now the LD can only go to about 20% volume before the right channel cuts out completely. The knob can also rotate a full 360 degrees (which I havent done while its powered on).  I've looked into this and have heard about people replacing the potentiometer with an Alps Blue 100k, should I do this? I have a friend who's experienced in electronics and soldering, I just want to be sure that theres not another easier solution to my problem.

I've been circumventing this issue by using the LD as a pre-amp and raising the volume through my FiiO K5, but I'd like to just fix the issue anyway so I wont have to worry about whether or not its causing distortion or something.

Thank you!


----------



## TrollDragon

Itzi said:


> Hello! I've recently joined after lurking this thread for a while because I have some questions to ask about my Little Dot II. I've been enjoying it recently with Sylvania 6SN7 power tubes and Mullard EF92 driver tubes, and im loving this setup. I also have some Voshkod drivers coming in soon, excited to try those. However, I do have one issue.
> 
> When I was first setting up my LD, I was struggling to find out how to open it to change the internal dip switches, and I tried removing the front panel. This damaged the volume potentiometer, and now the LD can only go to about 20% volume before the right channel cuts out completely. The knob can also rotate a full 360 degrees (which I havent done while its powered on).  I've looked into this and have heard about people replacing the potentiometer with an Alps Blue 100k, should I do this? I have a friend who's experienced in electronics and soldering, I just want to be sure that theres not another easier solution to my problem.
> 
> ...


You have damaged the potentiometer and it needs to be replaced, there is no easy fix.  I highly doubt that an ALPS Blue Velvet pot would fit in the MK2 without modifications to the board as the pin spacing is very different.

IMHO the best thing would be to just replace the broken pot with another one of the same type. 

ALPS Blue Velvet specs.






Existing A100K pot specs:


----------



## Itzi (Apr 18, 2021)

TrollDragon said:


> You have damaged the potentiometer and it needs to be replaced, there is no easy fix.  I highly doubt that an ALPS Blue Velvet pot would fit in the MK2 without modifications to the board as the pin spacing is very different.
> 
> IMHO the best thing would be to just replace the broken pot with another one of the same type.
> 
> ...


Okay, thank you for the advice. Which potentiometer would that be? I've tried looking it up but nobody has specified, unless I just dont know how to search properly. I tried reverse searching on TinEye but none of the results links work.

Edit: After using Reverse Image Search on google, I think I worked out the right one. Is it the b100k? I've found a few sets on amazon and if these are right, which do you think is the best? Thanks!
https://www.amazon.com/Taiss-Rotary...00k+potentiometer&qid=1618762699&sr=8-14&th=1
https://www.amazon.com/uxcell-Varia...9d1e3&pd_rd_wg=knFtz&pd_rd_i=B07JM2MZRW&psc=1


----------



## TrollDragon (Apr 21, 2021)

Itzi said:


> Okay, thank you for the advice. Which potentiometer would that be? I've tried looking it up but nobody has specified, unless I just dont know how to search properly. I tried reverse searching on TinEye but none of the results links work.
> 
> Edit: After using Reverse Image Search on google, I think I worked out the right one. Is it the b100k? I've found a few sets on amazon and if these are right, which do you think is the best? Thanks!
> https://www.amazon.com/Taiss-Rotary-Linear-Potentiometer-Control/dp/B07DJ7N6PH/ref=sr_1_14?dchild=1&keywords=b100k+potentiometer&qid=1618762699&sr=8-14&th=1
> https://www.amazon.com/uxcell-Varia...9d1e3&pd_rd_wg=knFtz&pd_rd_i=B07JM2MZRW&psc=1


The pictures I have seen of the Little Dot MK II uses an "A" type of pot, the ones you have linked on Amazon are "B" type and will not work correctly.
The best thing to do is take the bottom off of your amp and look at the pot to make sure it says A100K like the image below.




I can't find any "A" type pots on Amazon, but there are some on eBay from a US seller.
https://www.ebay.ca/itm/302359721877


----------



## lupoal

I think those two 220uF are the output caps... is there anybody here that replace them with something else with better quality? Which one and with what kind of results ?


----------



## Itzi (Apr 29, 2021)

Hi again people 

I've been listening to a few different tubes the past weeks on my MkII, and I wanna know if anyone has had a similar experience to me with the Voskhod 6J1P-EV's with a pair of Sennheiser 650's? Going from the Mullard 6CQ6 to these was a pretty drastic change, and now comparing them to my GE JAN 5654s I have identified why I havent really gone back to them. I loved the bass response, the "fullness", and the highs of the Voskhods, but the soundstage felt very claustrophobic. Like, with the GEs, Mullards, and even stock drivers, although the soundstage is different, I can pick out where different instruments are and things at least sound distinct. With the Voskhods, everything feels very in my head and overwhelming. It does fine with slower music, like laid back jazz or rnb, but taking it anywhere near electronic, rock, and metal, leaves me fatigued within an hour or so. Vocals also feel distinctly _too_ close.

As of now, the 5654s are the tubes I feel the most comfortable with. They dont have as wide a soundstage as the Mullards, but things just feel right and I tend to forget about the differences and just get lost in music easier, which the Mullards prevented me from doing with most albums due to their strong warmth. I really want to like the Voskhods, has anyone else had this experience and found it changes? I saw a lot of users talking about their long burn in time, but none of those posts mentioned anything about the soundstage, only that the harshness goes away. Thanks


----------



## triod750

Itzi said:


> Hi again people
> 
> I've been listening to a few different tubes the past weeks on my MkII, and I wanna know if anyone has had a similar experience to me with the Voskhod 6J1P-EV's with a pair of Sennheiser 650's? Going from the Mullard 6CQ6 to these was a pretty drastic change, and now comparing them to my GE JAN 5654s I have identified why I havent really gone back to them. I loved the bass response, the "fullness", and the highs of the Voskhods, but the soundstage felt very claustrophobic. Like, with the GEs, Mullards, and even stock drivers, although the soundstage is different, I can pick out where different instruments are and things at least sound distinct. With the Voskhods, everything feels very in my head and overwhelming. It does fine with slower music, like laid back jazz or rnb, but taking it anywhere near electronic, rock, and metal, leaves me fatigued within an hour or so. Vocals also feel distinctly _too_ close.
> 
> As of now, the 5654s are the tubes I feel the most comfortable with. They dont have as wide a soundstage as the Mullards, but things just feel right and I tend to forget about the differences and just get lost in music easier, which the Mullards prevented me from doing with most albums due to their strong warmth. I really want to like the Voskhods, has anyone else had this experience and found it changes? I saw a lot of users talking about their long burn in time, but none of those posts mentioned anything about the soundstage, only that the harshness goes away. Thanks


Have to admit that I haven't listened to the 6J1P-EV's but your description immediately struck me as something to try with the 5687 output tube that is sounding good to me, compared to 6N6P, but too 'distant'. These two tubes might actually be a good match as input and output. 5687 need an adapter that also can be used with E182CC which was the tube Little Dot intially was designed for and shipped with, until this E182CC became too scarce and expensive. I bought my adapters from 'xulingmrs' on eBay.

5687 is electrically close to Melz 6N12S/6H12C that I am using but much easier to find and cheaper too.


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## Itzi (May 4, 2021)

triod750 said:


> Have to admit that I haven't listened to the 6J1P-EV's but your description immediately struck me as something to try with the 5687 output tube that is sounding good to me, compared to 6N6P, but too 'distant'. These two tubes might actually be a good match as input and output. 5687 need an adapter that also can be used with E182CC which was the tube Little Dot intially was designed for and shipped with, until this E182CC became too scarce and expensive. I bought my adapters from 'xulingmrs' on eBay.
> 
> 5687 is electrically close to Melz 6N12S/6H12C that I am using but much easier to find and cheaper too.


I've looked into the 5687, and honestly I might try this. Im really happy with my 6sn7's but I cant help but want to have fun with different combos, so Ill look into a pair of em with some adaptors sometime!

I finally replaced the malfunctioning potentiometer in my MKII with the one TrollDragon recommended, and even though I didnt expect it, there is a definite improvement in the sound of my amp! The Voskhods dont feel as cramped anymore, though I still prefer the GE's because of the clarity and slight soundstage they gain in exchange for weaker bass compared to the Voskhods. I also got a pair of Gold Brand Sylvania 5654's pretty cheap with Ebay's 5$ off code, so those will be coming in later this month for some more fun


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## TrollDragon

Itzi said:


> I've looked into the 5687, and honestly I might try this. Im really happy with my 6sn7's but I cant help but want to have fun with different combos, so Ill look into a pair of em with some adaptors sometime!
> 
> I finally replaced the malfunctioning potentiometer in my MKII with the one TrollDragon recommended, and even though I didnt expect it, there is a definite improvement in the sound of my amp! The Voskhods dont feel as cramped anymore, though I still prefer the GE's because of the clarity and slight soundstage they gain in exchange for weaker bass compared to the Voskhods. I also got a pair of Gold Brand Sylvania 5654's pretty cheap with Ebay's 5$ off code, so those will be coming in later this month for some more fun


Glad to read that you got the pot fixed and all is good. Enjoy!


----------



## lupoal

people ... WARNING!

I discoverd something not nice about C3g with our LD... at least with LDII (last hardware version)... unsing the adapter C3g works with LDII but works badly, if you measure the voltage at the heaters pins you discover that it is only 5,7V instead of the NOT lower then 6,0V admitted

from where this behaviour? from the C3g that has a heater current load of 390mA (each) against the nominal load of 175mA of a 5654... in practice the load is the double and the transformer, at that output, collapse

what is the problem? the problem is that a underpowerd heater can cause a shortening of the tube life down to few hours instead of the expected 10.000... and C3g are rare and expensive!

at the moment I replace the C3g with the 6HM5, that unfortunately are quite far to be the same, waiting to modify those adapters I've done for the C3g to be able to power those heaters with an external linear power supply (probably based on LM317 or 7805)

to better understand about underpowered heaters:
https://www.diyaudio.com/forums/tubes-valves/211731-heater-wiring-bad-ugly-3.html
https://audioxpress.com/article/the-internal-life-of-vacuum-tubes


----------



## TrollDragon

lupoal said:


> people ... WARNING!
> 
> I discoverd something not nice about C3g with our LD... at least with LDII (last hardware version)... unsing the adapter C3g works with LDII but works badly, if you measure the voltage at the heaters pins you discover that it is only 5,7V instead of the NOT lower then 6,0V admitted
> 
> ...


Have you pulled the top cover off to see what the actual rating is on the transformer?  If you could post a picture of the label that would be great for the thread as we already have a few other models.


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## lupoal

pulling is enough or I have before to unscrew something?


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## triod750

lupoal said:


> pulling is enough or I have before to unscrew something?


Some screws maybe?  

The cover on my MKIVSE has four of them.


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## lupoal

uffff.... inside probably... outsid is completely flat, no screw ... nothing

ok, tomorrow I will check


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## mordy

lupoal said:


> people ... WARNING!
> 
> I discoverd something not nice about C3g with our LD... at least with LDII (last hardware version)... unsing the adapter C3g works with LDII but works badly, if you measure the voltage at the heaters pins you discover that it is only 5,7V instead of the NOT lower then 6,0V admitted
> 
> ...


I cannot speak from a scientific point of view, but based on my understanding tolerances up to 10% are acceptable in tube manufacturing. In addition, the electric grid itself is almost never spot on and voltages vary there as well; it is almost never exactly 120/220V etc. 
The C3g tubes were developed for underwater transatlantic telephone cable transmissions and must have been made for rugged use. The glass is tempered to withstand pressure (although fragile when "rolling" the tube). 10% of 6.3V = 5.67V.
However, if the manufacturer's spec sheet specifies other voltage limits that takes precedence.
The C3g tube has a life span in excess of 10,000 hours - I am not aware of tube failures.


----------



## Jolterrrr

Itzi said:


> Hello! I've recently joined after lurking this thread for a while because I have some questions to ask about my Little Dot II. I've been enjoying it recently with Sylvania 6SN7 power tubes and Mullard EF92 driver tubes, and im loving this setup. I also have some Voshkod drivers coming in soon, excited to try those. However, I do have one issue.
> 
> When I was first setting up my LD, I was struggling to find out how to open it to change the internal dip switches, and I tried removing the front panel. This damaged the volume potentiometer, and now the LD can only go to about 20% volume before the right channel cuts out completely. The knob can also rotate a full 360 degrees (which I havent done while its powered on).  I've looked into this and have heard about people replacing the potentiometer with an Alps Blue 100k, should I do this? I have a friend who's experienced in electronics and soldering, I just want to be sure that theres not another easier solution to my problem.
> 
> ...


I use Sylvania 6SN7 Also with pair of Siemens c3g  and pair of lorenz c3g. Buy those and you Will be happy! Trust me 🤤


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## lupoal

@mordy ... we have the same point of view but, unfortunately, in Siemens, or Lorentz etc, data sheet is clearly specified that the heater MUST work in the range 6,3 +/- 5%... that means from 6 to 6,7... and that sound strange to me too as the main power supply is never 230Vac ... in my case is almost all the time around 223, but can also be 240, but in both cases is roughly 5%

to be honest I’m quite annoyed by this fog around tubes and how to properly use them... somebody says “don’t worry” somebody else “are you crazy? That will destroy them in short time” ... is It possible doesn’t exist a single true rule? Uff


----------



## mordy

lupoal said:


> @mordy ... we have the same point of view but, unfortunately, in Siemens, or Lorentz etc, data sheet is clearly specified that the heater MUST work in the range 6,3 +/- 5%... that means from 6 to 6,7... and that sound strange to me too as the main power supply is never 230Vac ... in my case is almost all the time around 223, but can also be 240, but in both cases is roughly 5%
> 
> to be honest I’m quite annoyed by this fog around tubes and how to properly use them... somebody says “don’t worry” somebody else “are you crazy? That will destroy them in short time” ... is It possible doesn’t exist a single true rule? Uff


Very hard to find the real truth, but over the years I have not come across people complaining that the C3g tubes blew up or were short lived, so based on that I personally would not worry. But that is only my personal feeling and if you are worried you should not rely on that. Again, experience has not showed that the C3g tubes have problems.
Here is my favorite tube photo - a C3g without the shield at 425V plate current:




I believe that the blue color comes from a Beryllium getter.


----------



## gibosi

lupoal said:


> @mordy ... we have the same point of view but, unfortunately, in Siemens, or Lorentz etc, data sheet is clearly specified that the heater MUST work in the range 6,3 +/- 5%... that means from 6 to 6,7... and that sound strange to me too as the main power supply is never 230Vac ... in my case is almost all the time around 223, but can also be 240, but in both cases is roughly 5%
> 
> to be honest I’m quite annoyed by this fog around tubes and how to properly use them... somebody says “don’t worry” somebody else “are you crazy? That will destroy them in short time” ... is It possible doesn’t exist a single true rule? Uff



Well, if you were going to install them into an underwater transatlantic telephone cable transmission system and run them 24 hours a day, for a very long time, then yes, it would be most wise to follow the data sheet. But in your application if the heater voltage is a bit low or high, it's not going to make a measurable difference. My advice, relax and enjoy these tubes.


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## lupoal

yes, I have the same opinion about... I'm just a little scared by this diagram 





https://www.diyaudio.com/forums/tubes-valves/211731-heater-wiring-bad-ugly-post3012333.html

well, in the same thread there are more then one guy with doubts about that... I was wondering if the writer is another hi-fi guru declaring strange things... it would be interesting to find that RCA document, just for personal knowledge

here I founded another discussion about ... I still have to read it, so just for info  https://groupdiy.com/threads/reduced-filament-voltage.32746/

@mordy  the C3g without housing is really nice!


----------



## Jolterrrr

lupoal said:


> yes, I have the same opinion about... I'm just a little scared by this diagram
> 
> 
> 
> ...


You worry to much. 😉


----------



## lupoal

... ok


----------



## TrollDragon

lupoal said:


> yes, I have the same opinion about... I'm just a little scared by this diagram
> 
> 
> 
> ...


The first thing to keep in mind in these other threads is that most of the discussion is based around guitar amps that have power tubes.  The amplifiers we use are preamps that have no power output section.



> From that same thread on diyaudio post #53
> 
> This is why amps such as Scott, Fisher and such, which routinely ran 12AX7s (nominally 12.6v heaters) at 11v, sometimes even lower, work as well as they do. If the tube that can deliver 1.25ma, is only being asked to deliver .3ma current... then there is NO PROBLEM. In many phono and input preamp sections, this is the case!



You would have to do the math using the LD MK2 input circuit components and C3g to see if this is the case or not...


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## lupoal

TrollDragon said:


> You would have to do the math using the LD MK2 input circuit components and C3g to see if this is the case or not...



unfortunately I'm not able...

in any case a man in another forum pointed something interesting... it is not only a matter if the tube will lst longer or die earlier, it is also the fact that if that part of the transformer should, and do normally that, supply 6,3Vac when we see it collapsing down to 5,7V it means that the transformer in overloaded... the tube underpowered maybe will live two times longer in a LD2 condition... but the transformer?


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## triod750

lupoal said:


> unfortunately I'm not able...
> 
> in any case a man in another forum pointed something interesting... it is not only a matter if the tube will lst longer or die earlier, it is also the fact that if that part of the transformer should, and do normally that, supply 6,3Vac when we see it collapsing down to 5,7V it means that the transformer in overloaded... the tube underpowered maybe will live two times longer in a LD2 condition... but the transformer?


Does your amp with its tubes sound good to you?

(I have stopped trying to understand electric matters and this has made life easier for me. But there is nothing wrong in trying to understand and being pro-active).


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## lupoal (May 6, 2021)

... yes I like how it sounds... but, for example, not all the times with all the possible mix I can arrange with the tubes I have...

my target is not to understand the concept of “infinite” or the meaning of the life but if, as it is now, it can be set to work better or if, as it is, it is already fine and safe...  if there is something wrong that I can fix, if there is something I could improve without looking for Boson X ... I’m not looking for anything absurd, I will never buy a power cord at 4000 euro per meter... but this rolling tube fun sometimes could look approached in a little too easy way... just doubts, nothing serious

but i agree with you... knowledge is not, most of the time, the way to happiness ... but is that transformer overloaded or not?


----------



## Jolterrrr

lupoal said:


> ... yes I like how it sounds... but, for example, not all the times with all the possible mix I can arrange with the tubes I have...
> 
> my target is not to understand the concept of “infinite” or the meaning of the life but if, as it is now, it can be set to work better or if, as it is, it is already fine and safe...  if there is something wrong that I can fix, if there is something I could improve without looking for Boson X ... I’m not looking for anything absurd, I will never buy a power cord at 4000 euro per meter... but this rolling tube fun sometimes could look approached in a little too easy way... just doubts, nothing serious
> 
> but i agree with you... knowledge is not, most of the time, the way to happiness ... but is that transformer overloaded or not?


Unrelated. But have you tried hardware EQ your sound going into your dotty? I bought this one and now everything is perfect 🥰🥰🥰

Leicozic Dual 31 Bands Equaliser Digital Equalizador De Audio Equalizers A3 Profesional Sound System Stage & Karaoke Equipment
https://a.aliexpress.com/_mql6Gyt


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## triod750

lupoal said:


> ... yes I like how it sounds... but, for example, not all the times with all the possible mix I can arrange with the tubes I have...
> 
> my target is not to understand the concept of “infinite” or the meaning of the life but if, as it is now, it can be set to work better or if, as it is, it is already fine and safe...  if there is something wrong that I can fix, if there is something I could improve without looking for Boson X ... I’m not looking for anything absurd, I will never buy a power cord at 4000 euro per meter... but this rolling tube fun sometimes could look approached in a little too easy way... just doubts, nothing serious
> 
> but i agree with you... knowledge is not, most of the time, the way to happiness ... but is that transformer overloaded or not?


I know naathing about my transformer and even less about your transformer. My runs cool with most tubes. It runs much hotter with 6N6P than with 6SN7 or 6H12C for example. With 6BX7, 6BL7, A2293 and tubes of that kind I use an external psu. A2293, 6080 and 6AS7G generate a lot of heat and I don't expect them to be kind to the innards of any Small Dot. The other tubes mentioned give me no worries.

Right now I am listening to GE 5687 as outputs with a dual triode ECC82/12AU7 (Telefunken) as input. I believe the 5687 runs cooler than 6N6P, maybe because it uses an adapter that isolates it from the chassis. I have found the GE 5687 somewhat recessed previously, distant as I commented to Itzi. Since I find TFK ECC82/12AU7 a little on the bright side I wanted to check this combination. I think the TFK made the GE better to my ears. I will try a Philips 12AU7 later. These 12AU7 are tubes I already had. They are tubes that can be expensive today, at least as NOS. But who needs NOS? Use NOS tubes for a while and they are not NOS anymore. Are they less good then?


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## lupoal

Ok, I missed the point about NOS or NOT NOS anymore (sound like ... to be or not to be...   )

I will touch my transformer... unfortunately is not sexy at all


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## triod750 (May 7, 2021)

I have listened to this piece of music for a couple of hours, using 6J5GT/G in the 6AK5 position and GE 5687 in the 6N6P position, using adapters but no external power supply since it's not needed. I have been listening to the cd, being old school.

https://www.isrbx.net/3136605293-lina-nyberg-esbjrn-svensson-close.html



It sounds very beautiful - almost too beautiful to my ears since I am now spoiled with more meat to the bones. But if I had heard this from the beginning I would probably not have looked further.

I paid 2 EUR a piece for these input tubes. I will now listen to 6C5 in the same input adapters to compare. They cost me almost 4 EUR. If you don't want to spend on C3g, these are a good alternative. (I mean either of these tube types - or both). Some would say a better alternative. It's a matter of taste, ears and gear.

Please notice that I haven't listened to 5687 for quite a while and never with these input tubes. So take this for what it's worth; nothing, until you have compared for yourself.
Your own opinion is the one that counts.

(These input tubes tax the transformer even less than C3g does).


----------



## triod750

Have now listened for a while to the same tunes using this 6C5 as input http://www.r-type.org/exhib/aaa0060.htm
It gives more blood and sweat and less tears. In other words; it's not as beautiful/beautified - more real. The tone from the grand piano sounds more true to me, with a little more body.

Listening to another recording might give a different result but I doubt it.

@Itzi made me do this...


----------



## lupoal

triod750 said:


> ....
> 
> I paid 2 EUR a piece for these input tubes. I will now listen to 6C5 in the same input adapters to compare. They cost me almost 4 EUR. If you don't want to spend on C3g, these are a good alternative. (I mean either of these tube types - or both). Some would say a better alternative. It's a matter of taste, ears and gear.
> ...



man you live in a marvelous country as searching in ebay I can only find those tubes from roughly 20 euros/each... but anyway, I already have 3 couples (6pcs) C3g, I would like to use them


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## triod750

lupoal said:


> man you live in a marvelous country as searching in ebay I can only find those tubes from roughly 20 euros/each... but anyway, I already have 3 couples (6pcs) C3g, I would like to use them


C3g is a very good tube so I don't feel sorry for you if you decide to use them.  

I tried to verify my impressions of the above mentioned tube combination; RCA 6C5 and GE 5687 by listening to other kinds of music. I picked John Brannen; 'The Good Thief' and Tom Waits; 'Mule variations'. Very different from the first jazz vocalist/ grand piano but the impressions are the same. Very pleasant and enjoyable. Highly recommendable.

I use a Sony CDP XB-930 QS, Beresford Caiman SEG dac with linear power supply and  power supply enhancer, Little Dot MKIVSE and Sennheiser HD-650 with ZU Mobius cable. Nothing of this is regarded as high end.

I have tried a lot of tube combinations so far, and intend to keep on doing this, and the importance of synergy between all links in the chain becomes more and more clear to me. That is why you shouldn't blindly trust other people's recommendations. There might be golden nuggets to be found where you don't expect them. But if a lot of people recommend the same combinations they could be worth trying.

It was @mordy who suggested some years ago that I could try the GE 5687. I found it to be pretty good with C3g but I wasn't excited since I had recently found other tubes I liked more. I found them to be 'too distant' in their presentation. This combination with 6C5 gives much better synergy with my gear and ears.


----------



## triod750

When I looked for these 5687 tubes I found a seller in Germany with a pair of GE 5687 and one Sylvania 5687WA and one Tung-Sol 5687. I haven't bought any more since I found other tubes that interested me more. So I don't know what the other tubes have to offer in terms of synergy.

And @lupoal; @mordy use to say something like this; 'cheap tubes come to those who wait'.


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## lupoal

right!  but a C3g at two euros... it is more easy to walk on the water or listen Trump telling the truth


----------



## mordy

lupoal said:


> right!  but a C3g at two euros... it is more easy to walk on the water or listen Trump telling the truth


I think the other tubes mentioned were in the 2 Euro price range - not the C3g tubes. However, when I quote prices paid I always add in the shipping and tax which sometimes can be high.


----------



## triod750

lupoal said:


> right!  but a C3g at two euros... it is more easy to walk on the water or listen Trump telling the truth


Well, it was the 6J5GT/G that cost me two EUR. But I have for several years been on the lookout for real Lorenz C3g and found a pair recently for 20 EUR for the pair. That was cheap too.


----------



## lupoal

yes I remeber... 10 euros/each for C3g is extremely cheap... you should test them, especially about Gm, if they are fine then you are a very lucky man as, usually, they are between 40 to 70 euros/each ( 40 used... 70 NOS)

but, anyway, I was interested in reliability of C3g with LD2... not so much in price level


----------



## triod750

lupoal said:


> but, anyway, I was interested in reliability of C3g with LD2


My comment wasn't supposed to adress your worry  . But I have used C3g as my standard input tube for many years in my MKIVSE, listening for many hours almost every night without any problems. How that translates to your LD2 I don't know. I haven't ever read anything about electrical failure with C3g - just mechanical when removing them from sockets or adapters without proper care.



lupoal said:


> you should test them, especially about Gm


My only means to test them is by using them and they sound fine.



lupoal said:


> 10 euros/each for C3g is extremely cheap


Especially if they are genuine Lorenz. I was looking for a photo of the embossed logo on a genuine Lorenz C3g. When I had copied that photo I followed the link to where it came from and found a company selling 'electric surplus'. They had a few tubes, among them this pair. So I bought them and received them within a week - covid or no covid. My point of telling this was to underline what @mordy was saying - good things come to those who wait for it (not a direct quote).

I have a couple of 12AU7 testing weak and sounding good. Since I don't listen to the test result I don't worry. Since I didn't pay good money for them I don't worry.

I bought a Sylvania 6SN7GT - VT231 that was NOS but unbalanced between the triodes according to the seller. I got it very cheap. This tube sounds very good in my amp and neither me nor anybody else is able to tell in which channel it is positioned without seeing.

I am happier and enjoy listening a lot more when I relax.


----------



## lupoal

ok... you win


----------



## triod750

lupoal said:


> ok... you win


No, I don't, since I don't compete  . I am just sharing my opinion. To each their own.

This is just a hobby and everybody is allowed to go their own way. Then we can tell each other about our choices.


----------



## Jolterrrr

triod750 said:


> My comment wasn't supposed to adress your worry  . But I have used C3g as my standard input tube for many years in my MKIVSE, listening for many hours almost every night without any problems. How that translates to your LD2 I don't know. I haven't ever read anything about electrical failure with C3g - just mechanical when removing them from sockets or adapters without proper care.
> 
> 
> My only means to test them is by using them and they sound fine.
> ...


Exactly what company did you buy those Cheap genuine Lorenz from????


----------



## mordy

From Triod750: 
_"I have a couple of 12AU7 testing weak and sounding good. Since I don't listen to the test result I don't worry."_

A fellow Hi-Fier bought some 8 tubes. He has his own calibrated tester, and although all the tubes were supposed to be NOS, one of them measured low and below acceptable.
I asked him to put in one tube that measured very well and the tube that did not make the grade och compare them. (He has a high end amp in the $2000 range). He was astounded that he could not tell the difference in how they sounded! It was a real eye opener for him!
There are people that have used the same tubes for 10 or even 20 years and they are still good.
Personally, I think that the quest for only NOS tubes isn't necessary all the time. Seriuosly, how many tubes have actually worn out by use? Most failures come from electrical shorts and breakage by dropping them...


----------



## lupoal (May 9, 2021)

all correct but maybe appliable only at the game we are playing here inside... plug and play this or that because is "compatible", more or less, and the ampli seems will not be explode... good, I'm doing the same and I like it

... but there outside there are also people that build amplifier, or pre-amplifire or whatever, going trough a project that is calculated considering specific values from data-sheet were, for example, values like Gm or Vkf has a meaning and has to be taken in serious consideration... so probably a good tube and an end-of-the life one are not the same, otherwise people, in industry for example, or military application, will never replace tube

so, imho, what we are doing here is a nice/funny game... but it is all except science and the fact we are lucky that nothing explode doen't elevate that at science level... an example: the catode resistance should be, as from tube C3g manufacturer application specs, 180Ohm.... inside the LD Mk2 is 680Ohm, and probably has the same value inside the Mk3 and Mk4 too, not exactly the same thing isn't it?


----------



## triod750

lupoal said:


> so, imho, what we are doing here is a nice/funny game... but it is all except science and the fact we are lucky that nothing explode doen't elevate that at science level... an example: the catode resistance should be, as from tube C3g manufacturer application specs, 180Ohm.... inside the LD Mk2 is 680Ohm, and probably has the same value inside the Mk3 and Mk4 too, not exactly the same thing isn't it?


You are completely right in that we, or at least I, don't discuss at science level. We, or I, just discuss how to get the best out of Little Dot without breaking the bank. 

But real knowledge isn't just to know things, it's the combination of both knowing and having experience. In this community we are trying to help each other with this. Maybe we gather more experience than knowledge  .

I welcome science too, even when it is above my understanding.


----------



## mordy

lupoal said:


> all correct but maybe appliable only at the game we are playing here inside... plug and play this or that because is "compatible", more or less, and the ampli seems will not be explode... good, I'm doing the same and I like it
> 
> ... but there outside there are also people that build amplifier, or pre-amplifire or whatever, going trough a project that is calculated considering specific values from data-sheet were, for example, values like Gm or Vkf has a meaning and has to be taken in serious consideration... so probably a good tube and an end-of-the life one are not the same, otherwise people, in industry for example, or military application, will never replace tube
> 
> so, imho, what we are doing here is a nice/funny game... but it is all except science and the fact we are lucky that nothing explode doen't elevate that at science level... an example: the catode resistance should be, as from tube C3g manufacturer application specs, 180Ohm.... inside the LD Mk2 is 680Ohm, and probably has the same value inside the Mk3 and Mk4 too, not exactly the same thing isn't it?


When you speak to a tube amplifier designer - any such designer - they will tell you that it is all about making compromises. This is not an exact science.
Just sit back, relax, and enjoy what you are listening to, whether you are listening to your amp or listening to the music...
Both listening methods are valid, and I suspect that we all are doing both at different times.


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## triod750 (May 14, 2021)

When you find something that sounds good in your amp you can stop there and call it a day. You have what you need.

But you don't have to. I am now listening to a combination that is very pleasing. For input I use a Sittard made Philips E80CC, inspired by @gibosi  a long while back in this thread. As output  tubes I am using GEC made A2293 - four of them. Each of these equals half a 6AS7g (or 6080). They are single triodes while 6N6P are dual/double triodes. That is why I am using four. All these tubes needs adapters and external power supply. You don't need these tubes to enjoy your music. But I enjoy using them to enjoy my music.

Before trying these, I used a Ken-Rad made 6N7 for input and two Sylvania 6BL7GT for output. I enjoyed that combination too. Do I recommend it? I recommend you to enjoy your music in a way that makes you happy.

Little Dot is a very flexible amp. That much can be said.

Edit: I made a mistake; this E80CC isn't made in Sittard (since they didn't make that tube type) but in Heerlen. I mixed it up with another tube I have. Thank you @gibosi .


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## lupoal (May 16, 2021)

TrollDragon said:


> Have you pulled the top cover off to see what the actual rating is on the transformer?  If you could post a picture of the label that would be great for the thread as we already have a few other models.



here we are, at the end I've done a set of measurement using the original set of tubes from factory...
first of all the picture about the transformer, is somebody is able to traslate from chinese would be nice... well number are self-explaining






and how wires are connected inside the LD2 ... input, those two black-red in between are joined togher to reach the 240Vac, the Green is to OVdc at the output of the bridge whic is connected to ground, so porobaly the transofermer is shielded





and output, heaters ... a is twisted with b... c is twisted with d... the black wire is the connection to elevate the heater voltage... those connetion are all Vac and, in theory, sould be around 6,3V +/- 5% (maximun /-10% but not valid for all tubes models)  (sorry... blu mean blue ... and verde means green)





while checking for connection I've seen that the transformer has been quite poorely assembled... so I squeezed the external mtal part to avoid potential vibrations (that can cause electrical noise in the circuits that can damage audio quality)









now the funny part... with the original tubes, so no overload because of tube not considered in the original project, I've measured, with constant voltage from the wall of 220Vac ---> 144Vac at the output instead of 151,25Vac (from (165/240)*220)... not a big gap but 5% lower then target...

then I measured the values at tubes...









so, before somebody will start telling me "take it easy" or "it sounds good so who care" consider that (let's forget for a moment potential problems about shorter tube life)... too low voltage at heaters means lower temperature... that means lower level of electron emitted by katode... that means lower Gm... that means lower dinamic range, lower sound quality

the reason why the transformer has so poor quality is simple, the transformer is the most expensive part inside a tube amplifier... so our chinese friends declared some values and installed something that can't reach those values saving money... oh well, no, for sure it is only my unit that is under-powered

anyway... I'm thinking to remove that transformer and realize an external "brick" with better transformer and two regulated linear power stage to DC supply heaters (from Amazon roughly 10 bucks each), deleting in this way any variation/fluctuation in the 6,3V because of the Vac fluctuations

in the mean time I switched to some other tube well sounding but not so expensive


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## TrollDragon (May 16, 2021)

@lupoal thanks for the transformer label, too bad they didn't print the current output on it like they did the others.

Yes your best be might be a pair of external regulators to provide a solid 6.3V heater supply directly to the tube sockets. I would have a look at the board to make sure the filament pins don't go anywhere else before you unsolder the wires from the transformer I think the black wire for the input pair goes to the board someplace.

Edit Add: They do take the power for the LED from the input heater wires.


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## triod750

I have previously said that my output 6SN7/6H12C might sound a little more 'on their toes' (don't remember how I worded it) with external heating power, although they don't need it. I haven't checked what transformer I have. The only parts I have removed from my amp is all the brass. This gives better ventilation. I guess I have the same chassis as MK9.


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## lupoal

TrollDragon said:


> ...
> Edit Add: They do take the power for the LED from the input heater wires.



... that's another doubt I have... the 6N6P heaters are connected directly to the transformer, the 5654 winding on the transformer has a center tap that is connected to +Vdc to pull-up the heater voltage... I have no idea where this LED is connected , I will open the LD again to try to map it... but it's really crowdy


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## triod750

Before buying my MKIVSE I was lent a MKIII for a few months. I was told that the MKIV was the same amp with some better components. Then sombody told me that this MKIVSE was for sale as used. I bought it and compared them for a while before returning the MKIII. I liked my MKIV much better, thought it had a fuller, more relaxed sound but told myself that it was only in my head since it was mine.

Anyway, I just removed the transformer cover and found a toroidal transformer underneith upon a 'tray' with flanges, tightly bolted to the chassis. The tray is also screwed to the chassis and the transformer cover is then screwed to the flanges of that 'tray'. This seems very well made. The text on the transformer as follows:

MKIV Se    A few chinese 'letters' here.

I/P 0V----------220V            RED------RED

0/P 3,2V---0V---3,2V           BLU--BLK--BLU

0V-----6,6V                          GRN-----GRN

0V----175V                          YEL------YEL

               20160428   

Sorry, still no camera. But I am sharing, old school.


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## TrollDragon

I can't find the picture of the label in my MK IV (it was probably lost in the forum upgrade), but I do believe mine had current ratings on it as well as the voltage.

I'll have to dig through the pictures on my PC.


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## triod750

There are currently no ratings...  

But you have a toroidal transformer too?


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## triod750

With my external heater power supply  and additional adapters I have been able to experiment with a lot of not so common tube combinations. One of the tubes that I have liked since I first used it is the Melz 6H8C/6N8S. This is a Soviet version of 6SN7GT that I have used as output tubes. It is very transparent but a bit too much on the bright side of neutral. I have now revisited this old favourite using other input tubes. First I tried a Tung-Sol 6N7GT/G and this tamed the brightness without detracting from transparency. It made for relaxed listening. Then I tried Philips E80CC which also compliments the Melz 6H8C well, while being a little livelier than the Tung-Sol combination. Right now I'm listening to something unexpected; I am using a Sylvania 6BL7GT as input. It's probably a far fetched combination but it sounds really good too. The downside with this last combination is the slightest of hum in silent passages. They are better used as output tubes but the experiment was interesting.

Before this, I tried another Tung-Sol combination; 6N7GT/G for input and 6080 WA for output. The outcome was relaxed and neutral sound that might become a little boring in the long run. While the sound was more than acceptable the heat from these 6080 tubes (an electrical equivalent to 6AS7G) is a bit too much in our amps in my opinion. This isn't based on knowledge, I am just trying to avoid being careless. But four A2293 tubes - two per channel in adapters - runs cooler than 6080 in my amp and sounds a lot better in my opinion with the 'right' input tubes. They are single triodes while 6080/6AS7G are double triodes. 2xA2293 is about equal to one 6080/6AS7G.

But I get a long way towards that sound quality using 6BX7GT or 6BL7GT as output. These latter tubes run much cooler which is good and relevant during the summer months.

Just wanted to share some impressions...


----------



## mordy

triod750 said:


> With my external heater power supply  and additional adapters I have been able to experiment with a lot of not so common tube combinations. One of the tubes that I have liked since I first used it is the Melz 6H8C/6N8S. This is a Soviet version of 6SN7GT that I have used as output tubes. It is very transparent but a bit too much on the bright side of neutral. I have now revisited this old favourite using other input tubes. First I tried a Tung-Sol 6N7GT/G and this tamed the brightness without detracting from transparency. It made for relaxed listening. Then I tried Philips E80CC which also compliments the Melz 6H8C well, while being a little livelier than the Tung-Sol combination. Right now I'm listening to something unexpected; I am using a Sylvania 6BL7GT as input. It's probably a far fetched combination but it sounds really good too. The downside with this last combination is the slightest of hum in silent passages. They are better used as output tubes but the experiment was interesting.
> 
> Before this, I tried another Tung-Sol combination; 6N7GT/G for input and 6080 WA for output. The outcome was relaxed and neutral sound that might become a little boring in the long run. While the sound was more than acceptable the heat from these 6080 tubes (an electrical equivalent to 6AS7G) is a bit too much in our amps in my opinion. This isn't based on knowledge, I am just trying to avoid being careless. But four A2293 tubes - two per channel in adapters - runs cooler than 6080 in my amp and sounds a lot better in my opinion with the 'right' input tubes. They are single triodes while 6080/6AS7G are double triodes. 2xA2293 is about equal to one 6080/6AS7G.
> 
> ...


One reason the 6080 runs hotter is that each tube is 2.5A for a total of 5A, whereas A2293 is 0.95A for a total of 3.8A. Nevertheless, it appears to me that the 6080 runs hotter than the 6AS7 which is an equivalent but has a larger envelope.
IMHO you will not run into problems if you use external fan cooling.


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## triod750

mordy said:


> One reason the 6080 runs hotter is that each tube is 2.5A for a total of 5A, whereas A2293 is 0.95A for a total of 3.8A. Nevertheless, it appears to me that the 6080 runs hotter than the 6AS7 which is an equivalent but has a larger envelope.
> IMHO you will not run into problems if you use external fan cooling.


I agree with you that 6080 subjectively seems hotter than 6AS7G and that external fan cooling could prevent problems. However, long term effects from excessive heat might shorten the life of components. (I might worry too much about that. I can still hold my hand on transformer cover or on the chassis without being bothered). That wouldn't matter that much if I thought that the sound quality difference from using 'hotter tubes' was rewarding but I don't. Not in my amp. I don't doubt that those hotter tubes can give better reward in amps designed for them. But for me the A2293 sounds better and are cooler.


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## hamcha

*Amperex 6AK5/E95 (Orange Globe)*

Really wide sound stage but still very intimate. I catch myself turning my head hearing things outside of my headphones but quickly realize that the sound is coming from the headphones. COOL!!! Clear upfront trebles/highs & vocals.  Moderate punchy bass and low end.

FOR REFERENCE - Adding this as I have not seen much if any about these tubes and thought it might be worthy contribution.   I am a noobie so take this will a grain of salt. Also, I just got my LD1+.  I love this tube amp and really brings so much to the listening experience.  I have been listening to E95 tubes which are highly rated (Voskhod 6ZH1P-EV , Mullard M8100 / CV4010) but recently switched to Amperex 6AK5/E95 (Orange Globe) that came with the used LD1+ and had to reply to this thread with above notes.  Really enjoying these tubes..  Thanks.


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## gibosi

hamcha said:


> *Amperex 6AK5/E95 (Orange Globe)*
> 
> Really wide sound stage but still very intimate. I catch myself turning my head hearing things outside of my headphones but quickly realize that the sound is coming from the headphones. COOL!!! Clear upfront trebles/highs & vocals.  Moderate punchy bass and low end.
> 
> FOR REFERENCE - Adding this as I have not seen much if any about these tubes and thought it might be worthy contribution.   I am a noobie so take this will a grain of salt. Also, I just got my LD1+.  I love this tube amp and really brings so much to the listening experience.  I have been listening to E95 tubes which are highly rated (Voskhod 6ZH1P-EV , Mullard M8100 / CV4010) but recently switched to Amperex 6AK5/E95 (Orange Globe) that came with the used LD1+ and had to reply to this thread with above notes.  Really enjoying these tubes..  Thanks.



It's been many years since I had my LD, but I am not sure that Amperex actually made the 6AK5. Yours might be Mullard?


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## hamcha

gibosi said:


> It's been many years since I had my LD, but I am not sure that Amperex actually made the 6AK5. Yours might be Mullard?



Many years indeed.  I am late to the LD1+ party, but gotta say it still ROCKIN 
Here are a couple of photos for reference.  They came with Amperex Green & Yellow boxes too.

You got reccos/favorites on your LD experiences?
Blessings.
H


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## gibosi

Amperex, Mullard and a number of others were actually subsidiary companies of Philips based in Holland. And nearly every tube manufactured by Philips or one of it's subsidiaries had a production code etched into the glass.

I can't put my hands on a 6AK5 / EF95 manufactured by one of Philips subsidiaries at this time, but I can use a 6463, image below, to show you an example of Philips production code.

Cd indicates the tube is a 6463. The next character, 1, is the revision code.

The character at the beginning of the next row is a sideways triangle, which indicates that it was manufactured at the Heerlen factory in Holland

And 9 indicates 1959 and G indicates July.

So if you are still following along

The product code for 6AK5 / EF95 is 2E.

If yours were actually manufactured by Amperex, which was located in Long Island, NY, you would see an asterisk indicating that factory. However, Amperex was used as a brand name for nearly all Philips production sold in the US, so the tube could have been manufactured at any of their factories. 

I encourage you to grab a magnifying glass and with good light, check if you can see any etched codes in your tubes. The etching is pretty durable but sometimes it does rub off.

And if you do see etched codes, the following document will help you decipher them. Good luck! 

https://frank.pocnet.net/other/Philips/PhilipsCodeListAB.pdf


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## lupoal (Jun 1, 2021)

... one question for all you guys that have used, or are using, tubes tha required, because of power consumption or voltage, and external power supply for heaters... the filament of output tubes is floating from factory (that because the LD does a SRPP using the two trides inside the same tube that has only one connection for both flaments... so is not possible to elevate only one and elevating both is not sane in this case) but what about the input tubes?

from factory the input tubes filaments are elevated of roughly +5Vdc from a voltage divider in the main power stage... using external power supply you guys referenced it to the internal ground via that +5 (connected to dc 0V of external dc source) or left it floating?


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## mordy

lupoal said:


> ... one question for all you guys that have used, or are using, tubes tha required, because of power consumption or voltage, and external power supply for heaters... the filament of output tubes is floating from factory (that because the LD does a SRPP using the two trides inside the same tube that has only one connection for both flaments... so is not possible to elevate only one and elevating both is not sane in this case) but what about the input tubes?
> 
> from factory the input tubes filaments are elevated of roughly +5Vdc from a voltage divider in the main power stage... using external power supply you guys referenced it to the internal ground via that +5 (connected to dc 0V of external dc source) or left it floating?


I am not sure that I understand your question well. All I know is that supplying 6.3V from an external power supply that has adequate power works fine.
With adequate power I mean at least three times the current draw of the tube since the in-rush current can approach that at startup. In other words, if the externally powered tubes draw 5A in total you want a 15A power supply.


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## TrollDragon

I don't think we have ever used an external power supply for the input tubes, they have their own filament winding on the power transformer.  Any of the tubes we use that require external power usually don't have enough gain to be used as input tubes.

I really don't understand all the concern over heater voltages...  If you are going to use tubes not designed for this amp then just bypass the heater pins with a socket extender like many of the members have done.


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## triod750

Well, I use external power supply to feed both input and output tubes. I don't know the data of this psu - I just told @Deyan what I needed it for and he made it for me. I have an adapter system he also made for me where I can use several different input and output tubes. Some of the input tubes I have used require more juice than the internal transformer winding can provide. Recently I tried a 6BL7GT as input, just out of curiosity. While sounding pretty good it also had a tiny bit of hum and since I have better alternatives this was just an experiment. But this tube needs 1,5A for heater filaments.

Right now I am using E80CC, feeding it from external psu. Theoretically the internal psu would be enough since it needs just 0,6A but the adapter system is built on external heater feeding. I also have adapters for other tubes, like EL42 and 6J5 - one per channel, using internal transformer.

@lupoal, you are taking the discussion to a level where I unfortunately can't follow. I'm sorry for this. Enjoy your ride and let us know how it works out for you.


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## lupoal

mordy said:


> All I know is that supplying 6.3V from an external power supply that has adequate power works fine.
> With adequate power I mean at least three times the current draw of the tube since the in-rush current can approach that at startup. In other words, if the externally powered tubes draw 5A in total you want a 15A power supply.



hummm... I bought a trafo with 50VA output, 2 x 12Vac... that will feed two LM317T (after bridge rectifier and filter) with maximum output current of 2,2A each... so two 6SN7 are roughly 1,2A nominal total... two C3g are roughly 0,8A... bad news, I do hope the LM driving the 6SN7 will not shut down because overload protected...


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## triod750

The original transformer in my MKIVSE had no problem providing heater current for a pair of C3g and a pair of 5687. That is about 2,6A. I don't know if that information is of any use to you but maybe to somebody else.


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## lupoal (Jun 2, 2021)

it has no problem because you measured the real values or because it doesn't explode?
even the trafo inside my LDII seems to have no problems at all... but when you measure it you discover that all the voltages are below the suggested limits, that normally, in worst case, should not be below 6,3 -10% = 5,7V... now that probably also comes from the voltage in the appartment that, in may case, is (now) 225Vac instead of 230Vac (nominal)

but there are problems to be fixed
- first: the voltage we recevive at home is not stable, it change during the day and those changes influence the voltage inside our equipment... the voltage applide to the filament is critical as it has important influence on the sound quality... it has to be keeped within the limits in the tube manufacturer's data sheet and as more stable as possible... linear power supply and dc voltage is the best possible solution (but expensive... and LD has the target to be cheap.. so...)
- second: too low voltage at filament is recognized (not my opinion, search the web about) to have big influence in life time of the tubes... if is too low the life time can be greatly reduced
- third: if be at the limit of the -10% can be tollerate by many tubes with the C3g there is explicit information, inside the data sheet of all the three main manufaturers, that it MUST not be below -5%... that means 6V

well... at the moment I'm running my LD with coulpe of very good 6H8C (1952) and a couple of Brimar 6BE6W... it runs well and if tubes will die soon for sure I will not be happy but I can survive (those 6H8C are quite rare), at the end are less of 40 euros in total... normally I run LD with couple of C3g and couple of 6SN7GT Canada, in total are roughly 200 euros and those tube from Canada (real NOS I mean) are very rare (I could only find 4pcs of them in many months)... these tubes togheter sound, imho, in a fantastic way... I don't want to kill them because I think the power supply stage in the LD is fine but, in reality, it is doing an awful job instead

I hope with this I've also replied to those asking me... why?


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## mordy

lupoal said:


> it has no problem because you measured the real values or because it doesn't explode?
> even the trafo inside my LDII seems to have no problems at all... but when you measure it you discover that all the voltages are below the suggested limits, that normally, in worst case, should not be below 6,3 -10% = 5,7V... now that probably also comes from the voltage in the appartment that, in may case, is (now) 225Vac instead of 230Vac (nominal)
> 
> but there are problems to be fixed
> ...


You will be bored of them before they die - don’t worry!


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## triod750

If you have the knowledge and skills needed to give your amp a better psu, just go ahead and then tell this community what you have done and how you have sourced your components. The only measurements I have made is my incoming voltage and that is always 242V, at least every time I measure it. Day or night. I mostly listen late night to sometimes early morning when there is less disturbance of quality of electricity. Maybe my amp has a better transformer. And yes, I measured the voltage from my external psu and that is 6,35V so I can relax there. I make do with what I get from the internal transformer, trying not to worry too much since that isn't good for me  .

I have almost never heard of tubes giving in. Probably they gradually deteriorate but this is difficult to notice.

Keep on doing what makes you happy. You learn something in the process and you share this knowledge with others.


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## lupoal

triod750 said:


> just go ahead and then tell this community


for sure... as soon as it will be assembled and tested I will share pictures and the few necessary details


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## lupoal (Jun 14, 2021)

... under stress test (before to modify the LD2)

the 6N6P are quite serious load as are declared 750mA +/-50mA each... so at the limit of the regulator inside that is 1,5A nominal working load
the 6SN7, that are those I will use, are "only" 600mA each... so if the PSU survive now will have no problems in the future

next time pictures about few mods necessary inside the LD2 (very easy) and list of items used


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## lupoal (Jun 17, 2021)

Ciao,
here are the steps I've done to build an external PSU for LD MK2 tube's heaters...

the background: because of tube rolling game I've reached a configuration using two 6SN7 GE Canada and two Siemens C3g... the result was amazing, so good I decided to buy some more C3g and to check the heaters operating point (voltage) of the two C3g as the manufacturer strictly declare that the voltage, at heaters, MUST be within 6,3 +/-5% for expected life of 10.000 hours (I believe in continuos operating mode)... it is in many places available the info about serious life reduction if voltage at heaters is too low... well, I measured then and discovered that inside my LD2 it was seriously low, so low I switched to 6H8C + 6BE6W until and external PSU was ultimate. C3g are too precious to sacrifice them using in that way.

The targets:  
- an external PSU with adjustable voltage output, DC output (LD2 works very well powering filaments with AC but voltage is variable over the time and    AC could vehicle inside electrical noise form the 230Vac, or 110Vac), the DC output must be linear regulated to be independent    from main voltage variations
- the DC output must be separated for input tubes and output tubes... in LD2 the input tubes' heaters are connected to ground, and a little elevated via voltage divider in the Vdc circuit, the output tubes heaters are    completely floating as this is one good trick with SRPP configuration to keep the voltage heater-catode within safe values
- as output tubes and input tube will charge with different load the two circuits those have to be adjustable to be able to properly regulate the value at the tubes 
- as the tube rolling is a game that is difficult to stop a regulated/adjustable output is useful also for different tubes with different load characteristics in the future 
- regulation must not be easy accessible as it is necessary to avoid wrong values at the output because unwanted setting variation (for example …  touched by error during cleaning of the room) 
- it must be safe for electronic connected, the LD2, and for user 
- it should not look hugly

ok... here are links to components I've bought to realize it
- trafo ... just one
- pre-wired cables ... 2pcs
- fuse holder ... 2pcs
- for DIY PG
- housing
- socket with fuse
- for DIY PG
- power cable
- for marking wires I have to cut inside... to be able to reverse mod
- LM317 based electronics ... 2pcs
- cooling fan... I already had them (from a very old XBOX cooling accessory) so used something similar... nominal 12Vdc brushless, at 6Vdc run high enough but not noisy
- delta capacitor ... to be installed right behind the wall socket to prevent HF noise go into transformer and jump from primary to secondary winding


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## lupoal (Jun 17, 2021)

here are pictures about PSU construction






















not so much space left inside...

at the firts run, just one stage with two 6N6P (quote serious load as are 750mA +/-50mA each) the LM317 went in protection because of overheating in less the one minute... so the charge values declared by seller are pure b.s. with haet sink so small... but, as I don't trust chinese, I realized the ventilation grid with dimensions right to accept two fan 40x40 (all millimeters  )... so, one LM317 plate will drive the two output tubes, here I estimate a typical load with tube I'm going to use roughly 1,2A total... the other one will drive the input tubes + the two fan, two C3g are 300mA each + 300mA total for the two fan = 1A total.. fine





I've done measures under load... driving the two 6N6P there is a voltage drop between the value on the display and that on the tube's pins of about -0,3Vdc... driving the C3g shold be roughly half. Those values are important to know as potentiometer are too much sensible and, therefore, it is necessary to regulate the output without load to avoid supplying by error too much tension to tubes burning them


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## lupoal (Jun 18, 2021)

ok, it's time to put hands inside the LD...
following the original project and some suggestions from people here inside but also from other italian formuns and one of my friends (he is a appreciated hi-fi manufacturer) I left the two output tubes floating, that means no connection between the 0Vdc supplying them and the 0Vdc inside the LD electronic, and I grounded the two inputs tube connection the 0Vdc supply not were is in the original project (that is elevated of few volts) but at the 0Vdc of the electronic... the first picture is about this connection, the others are about cutted and identified cables from original transformer and DIY cable gland output (the holes inside the LD2 backplate are only 10mm diameters.. I've not been able to find any industrial PG with out 10mm and inside 4,5mm) so I had to realize one by myself






















about the cables, those are 4x0,34mmq which more then enough to drive the tubes... I named "high" that one dedicated to the two output tubes... as both are M12 male + M12 female just cut them in two parts and you will have a perfect prewired cables that will allow you to disconnect PSU from LD if/when necessary and reconect with reliability

then comes the time to connect them togheter, without any powering on the LD and without tubes, just for check there are no shorts or missing connections and to measure the voltages at the valves sockets





ok... no smoke... good  ... the voltage with no load at sockets is 0,1Vdc below the value on the display


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## lupoal (Jun 21, 2021)

ok... my expectation was to have maybe something slight better in the sound and much more reliability about tubes now with proper power supply...

I installed four tubes I can sacrifice n case of troubles ... two 6N6P dated 1984 and two 5654 JAN brand Penta, made in USA probably by GE... to be honest nothing really special... I also plugged in my old, but in MINT conditions, HD530 that I tried with LD2 without any fun, not enough bass response, not enough details and dynamic, not deep stage, nothing I would lie to use to listen music, something to leave in his cardboard box (that HD530 was amazing with cd player Marantz CD63 KIS)... the dac is my IFi nano BL iDSD, that I use with mobile and for tubes burn in, a nice dac but not really special.. I mean it is not a Mojo, source my mobile with Qobuz... mobile with USB Audio PLayer Pro





now... I'm simply surprised by the differences... it sound quite better ….
I should have done it before... it is really, to my hears, a quite big jump forward... almost speechless...

few additional notes:
- I've read in an old post about MK3 mods about problems of hisss coming from use of LT317... that's wrong, no hiss at all... in that case there were probably something wrong somewere else
- if you don't want to add cooling fan then you have to choose different way and build the electronic by yourself,just follow one of the many scheme you can find in the web (for example --> here ) and use much bigger heat sink... if you build the circuit by yourself consider to do something with higher output current capability, you can do that even with the LM317 adding a transistor like in the scheme you can find at the link I posted

*please note: if you want to use with loudspeakers then is a MUST to go for passive cooling with bigger heat sink, or maybe you can try with a larger fan like a Noctua 100mm diameter, as the 40x40mm fan even underpowered do emit a noise clearly  audible without headphone...in some moments I think I can hear them even trough the headphone, ummm, I have to change the place where it is now

June 21st 2021... see* update here


----------



## lior777 (Jun 17, 2021)

hey all !

I purchased a Little Dot 2 + maverick d2 dac with headphones hifiaman Sundra

I would like a recommendation for which tubes to upgrade and from where to buy? Hear mostly ethnic instruments, male voice, like this:





thanks


----------



## TrollDragon

lior777 said:


> hey all !
> 
> I purchased a Little Dot 2 + maverick d2 dac with headphones hifiaman Sundra
> 
> ...



The Sundara is a 37Ω/ 94dB planar headphone that really comes to life with a little bit of power behind it. The Little Dot MK 2 is an OTL tube amp designed for high impedance headphones of 150Ω or higher and it can't really provide the current required to properly drive low impedance planar headphones like the Sundara. You will also find that the output resistance of OTL amplifiers is higher than those headphones and will mess with the sound.  You might find that the MK 2 will power the Sundaras, but IMHO you are doing yourself a disservice by not pairing those headphones with an amp that has better synergy. 

What you need is an OTC (Output Transformer Coupled) tube amp or a Hybrid (tube input/solid state output). The OTC amps are quite expensive and generally start around $1000 where the Hybrids can be found for much cheaper.


----------



## triod750

lupoal said:


> not so much space left inside...


How about right inside?


----------



## lupoal

triod750 said:


> How about right inside?


 nice joke...

but only that? nothing to say about all the other things?
ummm... maybe a should use more audiophile-maniac sentencies... I would like to avoid but... ok, more black between instruments, improved high register with better reproduction of piano, better low frequencies with more articulated infos and more details, slightly improved sense of space (that could also be because of HD530).... bla bla bla...

now... I've done and verified that power supply really matter for both better silent background (my LD had no hummm or hissss at all) and better heaters temperature (that meand better electrons emission)... there is the list of items to be used and a quasi-step-by-step instruction... it is your time to move fingers not only on keyboard


----------



## triod750

lupoal said:


> nice joke...
> 
> but only that? nothing to say about all the other things?
> ummm... maybe a should use more audiophile-maniac sentencies... I would like to avoid but... ok, more black between instruments, improved high register with better reproduction of piano, better low frequencies with more articulated infos and more details, slightly improved sense of space (that could also be because of HD530).... bla bla bla...
> ...


I saw your posts in the middle of the night when I was going to shut down for bed. A lot of information not yet read. Will have to get back on this but thank you for the full report. Great contribution. 

(Watching European Championships consumes a lot of hours).


----------



## lior777

TrollDragon said:


> The Sundara is a 37Ω/ 94dB planar headphone that really comes to life with a little bit of power behind it. The Little Dot MK 2 is an OTL tube amp designed for high impedance headphones of 150Ω or higher and it can't really provide the current required to properly drive low impedance planar headphones like the Sundara. You will also find that the output resistance of OTL amplifiers is higher than those headphones and will mess with the sound.  You might find that the MK 2 will power the Sundaras, but IMHO you are doing yourself a disservice by not pairing those headphones with an amp that has better synergy.
> 
> What you need is an OTC (Output Transformer Coupled) tube amp or a Hybrid (tube input/solid state output). The OTC amps are quite expensive and generally start around $1000 where the Hybrids can be found for much cheaper.



thanks. i also buy it 

so i pull down the volume of dac and its good sound.

where i can buy new small and big tubes?


----------



## TrollDragon

lior777 said:


> thanks. i also buy it
> 
> so i pull down the volume of dac and its good sound.
> 
> where i can buy new small and big tubes?


eBay is your best source for replacement tubes.


----------



## lior777

i find the big tubes..how i search for the 2 small tubes?


----------



## TrollDragon

lior777 said:


> i find the big tubes..how i search for the 2 small tubes?


What do you mean by big tubes? Which ones did you find?

The input tubes (2 in front) have a lot of compatible choices, it all depends on what you want to try and which ones you like the sound of.  This thread is full of different tubes members have used in their amplifier.

This post has the table of compatible tube you can choose from.
https://www.head-fi.org/threads/lit...ube-rolling-guide.563884/page-77#post-9392055


----------



## triod750

lupoal said:


> nice joke...
> 
> but only that? nothing to say about all the other things?
> ummm... maybe a should use more audiophile-maniac sentencies... I would like to avoid but... ok, more black between instruments, improved high register with better reproduction of piano, better low frequencies with more articulated infos and more details, slightly improved sense of space (that could also be because of HD530).... bla bla bla...
> ...


I enjoy reading about other people's projects but I am not up to copying them due to lack of knowledge and skills. I have followed another path than you have to arrive at where I am right now. I can't be proud of my own doings as you can and should be but I can be satisfied with the result I have achieved, so far. I'm convinced that you will not stop here and am looking forward to further reports. Congratulations!

Regarding the more important European Championships, I expect the Italian team to be more successful this year since they are playing so well. I don't expect my team to beat your team this time, if they meet each other  .


----------



## lior777

TrollDragon said:


> What do you mean by big tubes? Which ones did you find?
> 
> The input tubes (2 in front) have a lot of compatible choices, it all depends on what you want to try and which ones you like the sound of.  This thread is full of different tubes members have used in their amplifier.
> 
> ...


hey, the little dot mk2 have 2 big tube and 2 small tube...

i find this:
https://www.ebay.com/itm/224482318506


----------



## lupoal (Jun 22, 2021)

update to this post

the problem with noisy fan has been solved replacing the two 50x50x20 with a single 80 x 80 from Noiseblocker... this fan has nominal voltage of 12Vdc but start running at 6Vdc, the speed is slower but more then enough to not go in overheating

two little problems are still open... supplying DC to all tubes via pcb, and cutting the wire from the transormer, put the status led into dc circuit.. that could also be fine but... the circuit in LD is done in a way that the led has roughly the same voltage at both sides, so it doesn't work... now
- I could connect on side of led to Ground, leaving it connected on the other side to heater +Vdc... that would probably work but showing only the PSU status or
- I could connect the led directly to the 6Vac free in the trafo... putting in between a diode + a resistor... in this case the led show the ampli status, but I have to place two additional wires inside the ampli (easy) but should disassemble the ampli again to reach the trafo... boring 





in any case I wanted to push a single button and start everything .... or start first the PSU for pre-heating and then the ampli... to reach the first possibility I've added a solid state relay (was in one of my drawer doing nothing) driven by one of the heaters power units... if I leave the switch back the ampli ON and use the switch of the PSU all go OFF or ON as required


----------



## Shane D

Just got some tubes in today. Not sure what to expect. They were pretty affordable and bought off Amazon. I will try them out tomorrow morning.


----------



## TrollDragon

Shane D said:


> Just got some tubes in today. Not sure what to expect. They were pretty affordable and bought off Amazon. I will try them out tomorrow morning.


Nice, my MK IV came with GE 5654 installed as stock, they were the first things I changed out.


----------



## Shane D (Jul 9, 2021)

TrollDragon said:


> Nice, my MK IV came with GE 5654 installed as stock, they were the first things I changed out.


Mine came with extra tubes, including 5654's, but they made a horrible sound and never settled down. I ended up throwing them away. I LOVE the Voshkods, but am curious about others.

I am actually using this amp right now, with a Schiit Loki in the chain. I have it on it mid-gain and am using my new T60 Argons.
Really nice sound. Very full and bassy, but it needs to be run at 2:00-3:00, depending on the music. If I was going to use just these, I might bump it up to high gain.

Before I turn everything on in the morning I will change the tubes and let it run for an hour or two. As long as there is no immediate noise.


----------



## TrollDragon

Shane D said:


> Mine came with extra tubes, including 5654's, but they made a horrible sound and never settled down. I ended up throwing them away. I LOVE the Voshkods, but am curious about others.
> 
> I am actually using this amp right now, with a Schiit Loki in the chain. I have it on it mid-gain and am using my new T60 Argons.
> Really nice sound. Very full and bassy, but it needs to be run at 2:00-3:00, depending on the music. If I was going to use just these, I might bump it up to high gain.
> ...


I'm out on the deck at the moment running my T50RP MK2 from the FiiO E12, would love to hear a pair of T60 Argons, very nice enjoy. 

Hopefully the 5654W perform well.


----------



## Shane D

TrollDragon said:


> I'm out on the deck at the moment running my T50RP MK2 from the FiiO E12, would love to hear a pair of T60 Argons, very nice enjoy.
> 
> Hopefully the 5654W perform well.


Right out of the gate they sound wonderful. No noise, no static and no channel imbalance. They sound very smooth and I am going through my test list.
Laptop to BF2 to Schiit Loki to LD MKIII to T60 Argons.
I wish I could do an instant back and forth with the Voshkods.


----------



## lupoal

production date?


----------



## Shane D

lupoal said:


> production date?


No idea. I will have a look later.


----------



## xxAMAROKxx

gibosi said:


> True, the getters themselves have no effect on the sound. And further, they have no effect on other things that do.
> 
> For those of us who collect tubes, the primary importance of the getter shape is that it provides an important clue as to when the tube was manufactured. For example, halo getters were first introduced in the late 1950's, and became common in the 1960's and into the 1970's. And therefore, a Mullard M8100 with halo getters was likely manufactured in the 1960's, or later. Prior to that, Mullard M8100's had rectangular getters.
> 
> ...


Hmm, I can hear smoother, more laid-back hieghts with the ring getter. Square getter is a bit brighter and maybe more extended.


----------



## gibosi

xxAMAROKxx said:


> Hmm, I can hear smoother, more laid-back hieghts with the ring getter. Square getter is a bit brighter and maybe more extended.



I have no trouble believing this. But I strongly doubt that any sonic differences you hear are solely due to the shape of the getter. It is more likely that coincident with the introduction of halo getters, Mullard made other changes to the construction of this tube due to new materials, new technologies and feedback from the field, and it is likely that some of these are not visible to the naked eye. Enjoy.


----------



## CADCAM

I have the LD MKIII and really enjoy the Yugo 6HM5 tall bottle tubes in it. Is the 6HM5 and 6HQ5 used safely in the LD MKIII? Is there any issue's running a 6HQ5? I don't want to do anything negative. The amp came stock with 5654's I believe. Is that whole family of 6J1, 5654, 6AK5 interchangeable with the 6HM5, 6HQ5 tube?


----------



## gibosi

CADCAM said:


> I have the LD MKIII and really enjoy the Yugo 6HM5 tall bottle tubes in it. Is the 6HM5 and 6HQ5 used safely in the LD MKIII? Is there any issue's running a 6HQ5? I don't want to do anything negative. The amp came stock with 5654's I believe. Is that whole family of 6J1, 5654, 6AK5 interchangeable with the 6HM5, 6HQ5 tube?



The 6HM5 and 6HQ5 are very similar. And in the LD, they can be considered identical.

The amp was actually designed around the 6J1, 5654, 6AK5. And as a lucky coincidence, the 6HM5 / 6HQ5 are also plug and play. Enjoy.


----------



## CADCAM

Tried the 6HQ5, and while good, I still prefer the Tung-Sol 6AK5W. My power tubes https://www.ebay.com/itm/313238472630 with the Tung-Sol drivers is so musical to me that I think I could keep this combo in for quite some time. Great hobby!


----------



## CADCAM (Jul 23, 2021)

I just got a Xduoo MT-602 hybrid headphone amp and have been rolling tubes in it with some great results. I was listening to Widespread Panic ~ Everyday and it sounded good being fed from my SMSL SU-8 DAC and NAD C542. Just to compare I put the same tracks on the Little Dot MKIII, itself being fed from a Maverick Audio D2 DAC and another NAD C542 I have (I love this CD player) and the LD thrashed the Xduoo completely. I know it should sound better the LD retails for almost three times the little Xduoo does and to be (un)fair I was using my Superlux HD668b cans with the Xduoo and my DT990 Premium (600 OHM) with the LD but man not even close. Maybe it's time to re-evaluate if I need 5 headphone amps...


----------



## amorrish

mordy said:


> Hi Mojo35,
> 
> There is no such a thing as Sylvania gold grid tubes. What you are referring to are Sylvania tubes with gold plated pins. Some people are getting insane prices for these JAN (Joint Army and Navy) 5654 tubes.
> As mentioned previously on this site, inexpensive Sylvania JAN 5654 tubes made in the 60' and 70's are identical to the ones with the gold plated pins, but without the gold plating on the pins, and they sound exactly the same. The way to identify these inexpensive tubes is to look for Contract Number DSA 900  on the box. Here is an example of the print line on the box: CONT. NO. DSA 900-67-C-9983 (This tube is from 1967).
> ...


issue. always have is I have to pay more for the shipping to the UK than the cost of the tubes


----------



## TrollDragon

amorrish said:


> issue. always have is I have to pay more for the shipping to the UK than the cost of the tubes


Same here in Canada, it is what it is...


----------



## triod750

You should buy more expensive tubes. That would solve the problem. Try Italy!


----------



## Deleeh

Hello,
I have always wondered why the left channel hisses as soon as you accidentally touch the tube, and also why the channel was usually not there when warming up.
And have found the cause. What is a bit annoying.
The capacitor circled in red wobbles a lot compared to the other one.
Does anyone know if I can replace it with something else?
Maybe Vcaps against Audionote.
And what is it responsible for?
A circuit diagram would be helpful.
The black capacitor says 25V 2200 uf.
I think they are through.

The other question is what are the capacitors marked with a red arrow for? I would swap them while I'm at it.
It says 16V 470 on it.

Would be grateful for help.


----------



## TrollDragon

Deleeh said:


> Hello,
> I have always wondered why the left channel hisses as soon as you accidentally touch the tube, and also why the channel was usually not there when warming up.
> And have found the cause. What is a bit annoying.
> The capacitor circled in red wobbles a lot compared to the other one.
> ...


I would take the board out and reflow the solder going to that capacitor, as it's probably just a bad joint.

As long as you replace caps with the same value you will be fine. I wouldn't worry too much about upgrading caps on a hybrid amplifer. Money is better spent on different tubes or headphones IMHO.


----------



## Deleeh

TrollDragon said:


> I would take the board out and reflow the solder going to that capacitor, as it's probably just a bad joint.
> 
> As long as you replace caps with the same value you will be fine. I wouldn't worry too much about upgrading caps on a hybrid amplifer. Money is better spent on different tubes or headphones IMHO.


Thank you for your answer.
I took the board out and like you I thought that the contact had probably loosened due to the last longer start-up of the small one.
But it didn't look like it, the wire sits relatively well in it and the wobble comes more from inside the capacitor.
I think it would have failed soon, and it was already beginning to show.
I haven't taken it out yet and have only ordered the parts for now, I'll see when they arrive because they are connected to the power supply on the back of the board.
I don't want to do anything wrong.
I saw two or three things that I didn't like.
The Rca sockets were a bit strange when I bought them, so I'll replace them when I get to them with a LAPP Olflex Classic 110 mains cable.
And I will also replace the sockets with higher quality ones with gold pins.
The current socket is a real horror, the tubes wobble on it which I don't like.

Capacitors I got from 
2200uF 25V Audio Note Kaisei NON-POLAR Electrolytic Capacitor,unfortunately I didn't find anything cheaper on Hificollektiv.if so it was not available.
The most expensive was 2 pieces just under 50 £.🙈
And the two small capacitors 
470uF 16V Nichicon FG type 2 pieces just under 2£.🙈🙈🙈

It's a bit annoying that Little Dot didn't invest in some better small parts. If the one capacitor wasn't so expensive or if they had found cheaper ones, we'd be talking about 20 max 30€, which I would have been happy to pay if Little Dot had included them in the assembly.

Otherwise it's not a bad amplifier, you just notice that they saved on the components and it didn't run too much, maybe 300 hours at the most.
Maybe I got a product that came from a mint.


----------



## TrollDragon

Deleeh said:


> Thank you for your answer.
> I took the board out and like you I thought that the contact had probably loosened due to the last longer start-up of the small one.
> But it didn't look like it, the wire sits relatively well in it and the wobble comes more from inside the capacitor.
> I think it would have failed soon, and it was already beginning to show.
> ...


Glad to read you sorted it, sometimes capacitors are not made well and can have a loose pin, best to replace it.  I changed out the headphone jack on my MK IV with a locking Neutrik version as the one that came installed from the factory was a 10 cent knockoff.  They cut corners to keep the price down, thankfully most replacement parts are cheap and even better if you have some soldering skills.  I was a board level repair technician for years working in the repair industry, so soldering and modification is second nature to me.

Good luck with your parts upgrade and keep us posted on how it turns out.


----------



## Deleeh

TrollDragon said:


> Glad to read you sorted it, sometimes capacitors are not made well and can have a loose pin, best to replace it.  I changed out the headphone jack on my MK IV with a locking Neutrik version as the one that came installed from the factory was a 10 cent knockoff.  They cut corners to keep the price down, thankfully most replacement parts are cheap and even better if you have some soldering skills.  I was a board level repair technician for years working in the repair industry, so soldering and modification is second nature to me.
> 
> Good luck with your parts upgrade and keep us posted on how it turns out.


Thank you very much,😊

I have nothing to do with electronics myself, which is a shame.
I can solder because I do it all the time and have a steady hand.🤗😇

I can still manage small things like replacing parts on the circuit board, but as soon as I have to measure, I'm out.
I have no knowledge of that.

I still have a problem with the 470uF 16V Nichicon FG type capacitor, which is not bipolar like the other one, but has plus and minus.
I could only find the name of the capacitor on the circuit board but no polarisation.
How can I find out where the polarisation is on the PCB?

If I can find out, I think I just need to be patient when moving it.


----------



## TrollDragon

Deleeh said:


> Thank you very much,😊
> 
> I have nothing to do with electronics myself, which is a shame.
> I can solder because I do it all the time and have a steady hand.🤗😇
> ...


Usually the negative side of the silk screening is filled in on the PCB. Have a look at this blog entry on capacitor markings.
https://macrofab.com/blog/the-footprint-files-electrolytic-capacitors/


----------



## Deleeh

Suuuppper, thank you so much, I'll look out for it when the material arrives and the fun can begin.


----------



## Deleeh

TrollDragon said:


> Usually the negative side of the silk screening is filled in on the PCB. Have a look at this blog entry on capacitor markings.
> https://macrofab.com/blog/the-footprint-files-electrolytic-capacitors/


Hello again,
Does it make sense to replace the film capacitor installed by Mex with the Wima or is it unnecessary to do the work?
I think I read that you once had problems with the Wima's not getting along with the power supply, but I can't remember exactly which Dot it was.

Here is the Mex in the link:
https://www.conrad.de/de/p/tru-comp...mm-l-x-b-x-h-18-1564957.html#productDownloads

And here the Wima:
https://www.conrad.de/de/p/wima-mkx...2-f-275-v-ac-10-15-mm-l-x-b-x-h-1-451671.html


----------



## TrollDragon

Deleeh said:


> Hello again,
> Does it make sense to replace the film capacitor installed by Mex with the Wima or is it unnecessary to do the work?
> I think I read that you once had problems with the Wima's not getting along with the power supply, but I can't remember exactly which Dot it was.
> 
> ...


I haven't changed any caps in my MK IV as it is a PiTA to get the board out of the case. The transformer cables are quite short and you can't run the amplifier with the board half out due to the hum.  

Like anything in this hobby YMMV and if you perceive better sound from a few inexpensive cap changes then it's all good.

For me it's not worth my time as I don't know enough tube theory to fully optimize my MK IV and I don't have the test equipment required to perform those changes.  There is a Little Dot MK III thread where a user optimizes his amp but most of his mods wouldn't apply to the hybrid.


----------



## Deleeh

TrollDragon said:


> I haven't changed any caps in my MK IV as it is a PiTA to get the board out of the case. The transformer cables are quite short and you can't run the amplifier with the board half out due to the hum.
> 
> Like anything in this hobby YMMV and if you perceive better sound from a few inexpensive cap changes then it's all good.
> 
> For me it's not worth my time as I don't know enough tube theory to fully optimize my MK IV and I don't have the test equipment required to perform those changes.  There is a Little Dot MK III thread where a user optimizes his amp but most of his mods wouldn't apply to the hybrid.


Hello,
Thank you for your suggestions.
I have seen the Threath, that would be too much of a good thing for me, and that is where my knowledge stops.

I will tend to only improve the small one, nothing more.
Or improve what you missed in the soldering.
Not really tuning.

As already mentioned, replace the capacitors, mainly the one that is broken.
The others are only a small test.
The tube sockets are replaced because a tube floats in it instead of being fixed.
The Rca line in sockets are silver plated and the cable is shielded for better signal transmission.
I will try to align the Wima's better because one presses on the solder joint and the other on the PCB.
Maybe drill 3-4 holes on the side of the case so that the heat can circulate better.

I think that's all I can do.
I don't think a "mod" would make sense either, or the intended improvements will be rather minimal and hopefully guarantee a more stable function. Everything else would only be a bonus if there are sound bonuses.
Of course you could do something about the power supply, but I would rather tackle that when it is broken and there is an improvement that might be cheap.


----------



## Deleeh

Hello,
it would be nice anyone can help me here for the resolve  my concerns.

https://www.head-fi.org/threads/little-dot-1-repairing.958968/


----------



## CADCAM

Listening to Mozart Sinfonia 364 Concertante on my Little Dot MKIII being fed from a Maverick Audio D2 in turn being fed from my NAD C542 on Beyerdynamic DT990 (600ohm) old skool rules...


----------



## triod750

lupoal said:


> Ciao,
> here are the steps I've done to build an external PSU for LD MK2 tube's heaters...
> 
> the background: because of tube rolling game I've reached a configuration using two 6SN7 GE Canada and two Siemens C3g... the result was amazing, so good I decided to buy some more C3g and to check the heaters operating point (voltage) of the two C3g as the manufacturer strictly declare that the voltage, at heaters, MUST be within 6,3 +/-5% for expected life of 10.000 hours (I believe in continuos operating mode)... it is in many places available the info about serious life reduction if voltage at heaters is too low... well, I measured then and discovered that inside my LD2 it was seriously low, so low I switched to 6H8C + 6BE6W until and external PSU was ultimate. C3g are too precious to sacrifice them using in that way.
> ...



@lupoal I just read this, following a link from another thread. I thought you might be interested: 

"LOW-VOLTAGE  OPERATION 
Tubes are designed  to be operated  at their  rated  fila
ment  voltages.  To get  the best over-all  satisfaction  from 
their  use,  they  should  be  operated  as  near  this  value  as 
possible.  However,  where  this  is  not  possible,  it  is safer 
to err on the low side  than it is on the  high  side.  In other 
words, if they are operated at 5 to 10 percent below their 
rated  center  value,  they  may  possibly  fail  to  give  quite 
as  many  hours of  service  at the remote end of their  life 
span, but they are not apt to suffer from as many compli
cations, or be prone to catastrophic failures as if they are 
operated  at  5  to  10 percent  above  their  ratings.  Where 
line  voltages  are  known  to  be  high  or  unstable,  the  use 
of  auto  transformers  to  reduce  the  voltage  a  fixed  per
centage  will  be a great  help  in stretching tube  life".

https://www.pearl-hifi.com/06_Lit_A...s/Tomer_Bud/Getting_the_Most-Vacuum_Tubes.pdf


----------



## mordy

triod750 said:


> @lupoal I just read this, following a link from another thread. I thought you might be interested:
> 
> "LOW-VOLTAGE  OPERATION
> Tubes are designed  to be operated  at their  rated  fila
> ...


----------



## lupoal

@triod750 

right! … my target was nominal voltage -5%… that is the limit in C3g data sheet… = 6,00 Vdc…that because tubes can run without problems down to -10% of nominal heater voltage but, do ask me why, with C3g the limit is… more limited 

anyway… in the last days I’m following a DIY forum to try to improve my knowledge about how to build a tube amplifier in “ classical” mode, without pcb, and, in the mean time I’m also reading about other improvement I could add to my LD MK2 rebuild… it is everywhere specified that one of the most important part of a tube amp is the power supply of heaters as everything start there, heaters are the engine of the tube… electrons start from there… and extremely important is the voltage, as close to nominal as possible, and purity power supply… that should be DC an not AC as commonly used (probably because cheaper) and with less noise as possible

anyway… thanks for interesting link you posted, saved in my library


----------



## TrollDragon

lupoal said:


> I’m following a DIY forum to try to improve my knowledge about how to build a tube amplifier in “ classical” mode, without pcb


Good luck and have fun, there are thousands of amps designs out there to build on. 


Building a PTP wired amp would be a great project, nothing looks nicer than PTP IMHO.


----------



## Deleeh

Little Dot 1+

Hello,
My repair on the Little Dot 1+ was slow at first with a few difficulties after the rebuild/repair.
Thanks to 2 guys who helped me Diy Threath to find the causes, he runs again.Here again a big thank you.

As a reminder, an electrolytic capacitor from the power supply was defective on one of the poles and the left tube socket was also defective.

I replaced the 2200uf/ 25 v electrolytic capacitors with the Audio Note standard ones. (Hificollektiv)
The 2 tube sockets were replaced by ones with gold pins and set a little higher for more stability.(Hificollektiv)
The Elna electrolytic capacitors were replaced with 470 uf/16 v Nichicon Fg.(Hificollektiv)
Replaced the film capacitors with 2 new ones from Mex.(conrad electronik germany)
Some of them were bent to 90 degrees, one was pressing on the PCB and the other on the tube socket.
Replaced the Rca sockets with Audio note ones and re-soldered the wiring with silver instead of copper.(Hificollektiv and supermarket)

I kept the standard values for the capacitors, but replaced them with higher quality ones.

I kept running the little one to give burn in in a few hours.
I used the Brimar Ef92 tubes.
I left the Opa original for now.
(more about that later)
Headphones are currently the Aeon R/T.

I was glad that it was running again.
During the burn in I noticed that the bass had increased a bit and that the treble range had gained a bit more shine (probably due to the Nichicon Fg).
This remained the same afterwards, and it was remarkable that the overall temperature of the device was reduced by quite a bit and remained stable throughout, even after 4 hours and more.
I suspect that the Audio Note standard electrolytic capacitors contribute a lot to this.

With time I noticed that I was missing a bit of the final touch that it had before.
I spontaneously remembered that I still have a Burson V5i Opa.
I used it and gave it some time.
I didn't like the Burson as much as the original Opa before the rebuild and found it more than a step backwards compared to the original.
I thought it coloured the sound a bit too much and the bass was a bit off.
After rebuilding and replacing the Elna's with the Nichicon Fg, I think the Burson suits it better.
I think it brightened up the stage a bit more, and the breaks and separations are more coherent and fit better together in terms of tuning.
And brings a bit more stage freedom and closer to the vocals.
The bass has also become crisper and more to the point with a bit of pressure and in the right place.

What I was still missing after the rebuild was the light syrupy and fluid flow of the music.
That came back with the Burson.
I am blown away even though I personally did not know much about capacitors etc.
The result was positively surprising and not even expected.

Finally, it is worth making the small investment.
The capacitors are not too expensive.
In fact, you would probably only have to replace the Elna with the Nichicon Fg to get right down to the cost with the Burson V5i.
I can't say whether the Audio Note standard really has an additional influence.
Possibly they do.
The most expensive will probably be the Burson, which costs around 50€ at the time.

It's a pity that Little Dot saved money because of two or four capacitors in order to do without a better result.
This would have been a good added value and would have reduced the failure rate.

You are welcome to use this excursion as inspiration from me or as help for a repair or tuning possibility.
If the results were not so good, I would have left it uncommented.Have fun,✌️.


----------



## aviationwiz

I've done some searching and haven't found much - are there any socket savers people would recommend to use with the Little Dot Mk2?


----------



## jonathan c

aviationwiz said:


> I've done some searching and haven't found much - are there any socket savers people would recommend to use with the Little Dot Mk2?


The LD MKII, using 6JI and 6N6 tubes which are nine-pin (nonal), should accommodate these. (https://pulsetubestore.com for more information). PTS is located in India.


----------



## mordy

jonathan c said:


> The LD MKII, using 6JI and 6N6 tubes which are nine-pin (nonal), should accommodate these. (https://pulsetubestore.com for more information). PTS is located in India.


I am sure that the $28 socket savers are of great quality. The low cost Chinese alternative is not the greatest quality but usable - 4 for less than $10:
https://www.ebay.com/itm/153592404771?hash=item23c2d21b23:g:fc8AAOSw3hFdSMMM


----------



## aviationwiz

jonathan c said:


> The LD MKII, using 6JI and 6N6 tubes which are nine-pin (nonal), should accommodate these. (https://pulsetubestore.com for more information). PTS is located in India.



Excellent, thanks. Looks like this will work excellently for the larger (preamp?) tubes, though the driver tubes are 7 pin.


----------



## jonathan c (Aug 23, 2021)

aviationwiz said:


> Excellent, thanks. Looks like this will work excellently for the larger (preamp?) tubes, though the driver tubes are 7 pin.


The adapters should work for the seven-pin tubes if the tube pins are similar in thickness to those of the adapters. One question does come to mind. Do the tube sockets for the driver tubes have nine outer “holes”?


----------



## aviationwiz

jonathan c said:


> The adapters should work for the seven-pin tubes if the tube pins are similar in thickness to those of the adapters. One question does come to mind. Do the tube sockets for the driver tubes have nine outer “holes”?


Nope, just 7.


----------



## jonathan c

aviationwiz said:


> Nope, just 7.


In that case, you should private message fellow Head-Fier @Deyan. He has made for quite a few Head-Fiers, including me, custom tube adapters. His workmanship is of a very high standard! I cannot imagine that adapters for LD MKII driver tubes would be a problem for him.


----------



## gibosi

Several years ago, when I had my LD, I used these NOS 7-pin socket savers. I suspect that they are pretty rare now, but they do exist.


----------



## TrollDragon

Seven pin socket saver are just about impossible to find these days.


----------



## triod750

TrollDragon said:


> Seven pin socket saver are just about impossible to find these days.


I don't know about other Little Dot models but the sockets in my MKIVSE seem like they can take a lot of abuse. I have changed tubes a lot and the grip is as snug as when I received the amp. Socket savers can be of help in the output position to isolate the chassis from heat though, depending on tubes used. 6SN7 and 6H12C run a lot cooler than 6N6P but since you use these with adapters you have extra isolation anyway.


----------



## mordy (Aug 24, 2021)

TrollDragon said:


> Seven pin socket saver are just about impossible to find these days.


You can still find them, but some prices are crazy. The one to look for is this one - $49 at this site:
(TUA) TVS-7
*Pomona* 7 pin miniature tube socket saver test adapter. Eyelets for hook clip leads for each pin.



https://www.surplussales.com/Tube-Sockets/TubeSkts-1.html
There are some offers on eBay for better prices. As always, PP - Patience Pays, and if you take your time you will be able to find them at more reasonable prices.
Here is another listing for $23:
https://picclick.com/Vintage-Vector®-Model-7-Pin-Miniature-Extended-Tube-Socket-324705644406.html?refresh=1
One search tool, in addition to eBay, that I found useful is to bring up the item on Google Images and then click on individual items to see what is for sale:
https://www.google.com/search?q=7+pin+vacuum+tube+socket+tester+adapter&sxsrf=ALeKk03_-LWbQaPgHL13-svpmyXRt-V76Q:1629835752066&tbm=isch&source=iu&ictx=1&fir=O8Gd1L684PT5XM%2C7YGaq6-wA2Ta_M%2C_&vet=1&usg=AI4_-kRJC9KmaNy2abK4G1KJPi4jOX2tBw&sa=X&ved=2ahUKEwjJy6you8ryAhUuElkFHctLCVYQ9QF6BAgLEAE#imgrc=odefUf5trNhtMM

You can also try Leeds Radio:
https://www.etsy.com/shop/LeedsRadio?ref=shop_sugg


Good luck!


----------



## TrollDragon

Good find on the socket savers but they are way too pricey and sit way too tall IMHO.


----------



## TrollDragon

triod750 said:


> I don't know about other Little Dot models but the sockets in my MKIVSE seem like they can take a lot of abuse. I have changed tubes a lot and the grip is as snug as when I received the amp. Socket savers can be of help in the output position to isolate the chassis from heat though, depending on tubes used. 6SN7 and 6H12C run a lot cooler than 6N6P but since you use these with adapters you have extra isolation anyway.


Yes they are quite durable, I've have jumpers in mine as well as tubes with crooked pins etc.  If they do get sloppy it would be easy enough to resolder a new pair of ceramic machined pin sockets onto the board.


----------



## mordy

TrollDragon said:


> Good find on the socket savers but they are way too pricey and sit way too tall IMHO.


Agree. But if you have patience they sometimes came up for much less.
I used them a lot when we experimented with oddball tubes in the LD MKIII in the old days.


----------



## ToxicRisk

I'm going to buy a Little DOT MK3 SE, what is your advice for DAC pairing ?
Thanks


----------



## TrollDragon

ToxicRisk said:


> I'm going to buy a Little DOT MK3 SE, what is your advice for DAC pairing ?
> Thanks


dCS Bartok.


----------



## ToxicRisk

Hmm a little bit pricey


----------



## vmiguel (Aug 30, 2021)

ToxicRisk said:


> I'm going to buy a Little DOT MK3 SE, what is your advice for DAC pairing ?
> Thanks


I have a Little Dot Mk II and it pairs very well with Cambridge DacMagic 200M, my current dac.
If it's still out of budget, I also liked it very much with Topping D10S and Allo BOSS2 player/streamer.
I believe the tubes and headphones will have a bigger impact on sound quality and sound signature than the dac.

Maybe if you state your budget you will get better help...


----------



## ToxicRisk

Thanks,
I was also thinking of the Bifrost 2 in balanced.

I've a question about the Mk3 SE, is a OTL amp ?


----------



## vmiguel

The Cambridge also have balanced output.


----------



## TrollDragon

ToxicRisk said:


> Thanks,
> I was also thinking of the Bifrost 2 in balanced.
> 
> I've a question about the Mk3 SE, is a OTL amp ?


The MK 3 SE is not an OTL amp, it's a hybrid with transistor output.


----------



## CADCAM (Sep 16, 2021)

Quick question - does anyone have info on the Tung-Sol 6AK5  0-getter vs the square getter??
I have 2 pair of the square and love the sound but wondered if the round was even better...
Using them in my LD MKIII

OK so I can answer my own question, the square getter is the original older type from the 50's and the 0 or round getter is the "newer" style or so I just read on another site.
The square getter are said to sound better than the round, so it seems with 2 pairs I'm good to go!
Carry on...


----------



## kgs51

I just purchased the little dot MK3 and was wondering what upgradeable replacement tubes I should purchase for this unit to improve the sound further.
Thanks for your help


----------



## ToxicRisk (Sep 23, 2021)

Just buy a little dot Mk3 SE (hybrid balanced).
Anyone know the output impedance?
Please someone can explain me how to use the internal switch to match all the headphone impedance ?
Thanks


----------



## TrollDragon

ToxicRisk said:


> Just buy a little dot Mk3 SE (hybrid balanced).
> Anyone know the output impedance?
> Please someone can explain me how to use the internal switch to match all the headphone impedance ?
> Thanks


Did you not get a manual with your amp?

The output impedance is not published from Little Dot so someone would have to measure it with test gear.  The switches on the bottom control the gain of the amplifier and there are only 2 settings, all 4 on for 4.5 (low) gain and all 4 off for 9 (high) gain.  Unlike the regular MK III there are no other combinations of switch settings on the SE.


----------



## TrollDragon

kgs51 said:


> I just purchased the little dot MK3 and was wondering what upgradeable replacement tubes I should purchase for this unit to improve the sound further.
> Thanks for your help


I've run these drivers in my MK IV for the past 5+ years, they are a great sounding tube.
https://www.ebay.com/itm/401082139160


----------



## mordy

TrollDragon said:


> I've run these drivers in my MK IV for the past 5+ years, they are a great sounding tube.
> https://www.ebay.com/itm/401082139160


Since you will need a pair this listing might be less:
https://www.ebay.com/itm/252408982540?epid=168051561&hash=item3ac4bf6c0c:g:rrYAAOSwDk5UHHgE
There is also a best offer feature - way back they accepted $5 but don't know what the current low price is. Perhaps you can bid $5 on Trolldragon's tube and ask if they combine shipping with the same price shipping for two.


----------



## TrollDragon

mordy said:


> Since you will need a pair this listing might be less:
> https://www.ebay.com/itm/252408982540?epid=168051561&hash=item3ac4bf6c0c:g:rrYAAOSwDk5UHHgE
> There is also a best offer feature - way back they accepted $5 but don't know what the current low price is. Perhaps you can bid $5 on Trolldragon's tube and ask if they combine shipping with the same price shipping for two.


That listing is for the short version of the tube, you definitely do not want those. 

The tall version of the 6HM5 is the one to buy.


----------



## mordy

TrollDragon said:


> That listing is for the short version of the tube, you definitely do not want those.
> 
> The tall version of the 6HM5 is the one to buy.


Thanks - I did not know that there are two versions; only have the tall one.
BTW, I have made an observation over the years that larger tubes often sound better. I am sure that there are exceptions, but somehow it appears to me that the larger/taller tubes are better sounding in general.


----------



## CADCAM

kgs51 said:


> I just purchased the little dot MK3 and was wondering what upgradeable replacement tubes I should purchase for this unit to improve the sound further.
> Thanks for your help


I run these power tubes https://www.ebay.com/itm/313238472630
and my favorite driver is the 1950's Tung-Sol 6AK5 square getter.
I have had my amp for many years and this is the best sound I have come up with.


----------



## CADCAM

Like TrollDragon I also ran the Yugo 6HM5 tall bottles, great tube in my LD. The Sylvania 6HQ5 is also an option.


----------



## lior777

Hey guys, 

i buy little dot 2 + sundara , now i connect him to Maverick D1 dac - do you recommend me to switch to another  dac?

also i would like to get a recommendation for lamps to little dot 2, most of my music is authentic musical instruments, male voice, lots of emotion, looking for an intimate stage, as close as the attached youtube:




thank you all


----------



## TrollDragon

lior777 said:


> Hey guys,
> 
> i buy little dot 2 + sundara , now i connect him to Maverick D1 dac - do you recommend me to switch to another  dac?
> 
> ...



The Little Dot MK 2 is an OTL amplifier with a high output impedance not designed to drive low impedance planars like the Sundara. It cannot provide the current required to make planars come to life and sound their best. You would find better synergy using a hybrid amplifier or solid state with those headphones.


----------



## TrollDragon (Oct 5, 2021)

Just looking at the specs for the Maverick D1 and it has a 1W headphone amplifier that should drive the Sundaras very nicely.


----------



## lior777

TrollDragon - hey so i will sell it..i love the sundara. 
i didnt like the amp mavrick d1..


----------



## TrollDragon

lior777 said:


> TrollDragon - hey so i will sell it..i love the sundara.
> i didnt like the amp mavrick d1..


You would need a hybrid amplifier if you want a tube type sound with the Sundara or you would have to go to an OTC (Output Transformer Coupled) tube amp if you want a pure tube experience, but those start around $1K and go up from there.


----------



## henree

Can someone tell me what these tubes are. I am trying to figure out which tube family they belong to. So I can set my jumpers on my amplifier correctly.
Its hard to make out the writing on the tube. it says 6 and HQ5 below.


----------



## mordy

henree said:


> Can someone tell me what these tubes are. I am trying to figure out which tube family they belong to. So I can set my jumpers on my amplifier correctly.
> Its hard to make out the writing on the tube. it says 6 and HQ5 below.


The 6HQ5 is a triode. From the lettering it looks like a GE tube.


----------



## jonathan c

TrollDragon said:


> You would need a hybrid amplifier if you want a tube type sound with the Sundara or you would have to go to an OTC (Output Transformer Coupled) tube amp if you want a pure tube experience, but those start around $1K and go up from there.


Don’t forget the Schiit Valhalla II at $349. I use it (among a few other h/p/a) to run Audeze LCD-X through ZMF Auteur. Great results 🎶🎉👍.


----------



## henree

mordy said:


> The 6HQ5 is a triode. From the lettering it looks like a GE tube.


My little dot has settings for certain families of tubes.
I can use the 6JI,6A5K,5654 tubes on one setting
AND EF91,92 CV131,138 tubes on another setting
Do you know which of these settings are for this triode?


----------



## mordy

henree said:


> My little dot has settings for certain families of tubes.
> I can use the 6JI,6A5K,5654 tubes on one setting
> AND EF91,92 CV131,138 tubes on another setting
> Do you know which of these settings are for this triode?


If you go to the Radiomuseum and type in 6HQ5 you will find listings of other tubes with the same or similar characteristics and pinout such as the 6HM5.
https://www.radiomuseum.org/tubes/tube_6hm5.html
https://www.radiomuseum.org/tubes/tube_6hq5.html
If I remember correctly, people use the 6HM5 in the Little Dot on the 6AK5/EF95 setting so the 6HQ5 may be compatible.  But I am not sure and do not want to give the OK to use it. You may want to ask Trolldragon or gibosi. Or you can ask Deyan as well.
The voltage and current draw of the 6HQ5 are certainly compatible with the Little Dot MKIII.


----------



## henree

mordy said:


> If you go to the Radiomuseum and type in 6HQ5 you will find listings of other tubes with the same or similar characteristics and pinout such as the 6HM5.
> https://www.radiomuseum.org/tubes/tube_6hm5.html
> https://www.radiomuseum.org/tubes/tube_6hq5.html
> If I remember correctly, people use the 6HM5 in the Little Dot on the 6AK5/EF95 setting so the 6HQ5 may be compatible.  But I am not sure and do not want to give the OK to use it. You may want to ask Trolldragon or gibosi. Or you can ask Deyan as well.
> The voltage and current draw of the 6HQ5 are certainly compatible with the Little Dot MKIII.


Thanks. You were correct. They belong to the 6AK5 FAMILY.


----------



## CADCAM

I tried the Sylvania 6HQ5 in my LDMKIII without issue, I prefer the Yugo 6HM5 tall bottles to them and my favorite thus far has been the Tung-Sol 6AK5 (square getters).
My LD, with a Maverick Audio D2 DAC and Beyerdynamic DT990 (600ohm) still impress the $#!+ out of me for the cost.


----------



## triod750

My Little Dot MKIVSE was delivered with EH 6N30Pi as output tubes. I listened to them for a while before starting my tube rolling journey. I have posted just a little about it. Tonight I revisited these 6N30Pi with 6J5GT/G in adapters to the 6AK5 input sockets. They were like I remembered them, a little anemic. It's like looking at a picture with few pixels - you see the picture but there is a lot missing. I pulled out other tubes to compare them to, without using external power supply. I chose the dual triode 5687 that is electrically close to E182CC and Melz 6N12S but more available and thus cheaper. American tube manufacturers made loads of them and they are good quality tubes. With this tube the picture has a lot more pixels. I can see it much better with less strain. They also need adapters but are well worth it - in my opinion. They are not my best tubes but might be best value for money, at least for me. But I rarely use them.


----------



## triod750

For input tubes I have used the common ones up to 6HM5 and C3g. With adapters but without external power supply I have used C3g but also EL42 and 6J5 types and 6C5 types. With external power supply and adapters I have also used different dual triodes as 6N7, 6SN7/6N8S, 12AU7/ECC82, 12AT7/ECC81/6201, E80CC, 6F8G and probably one or two other tubes.

For output tubes I have used 6N6P variants, 6N30Pi, different 6SN7GT, 6F8G, 5687, 6N8S, 6N12S, these without external psu and 6BX7GT, 6BL7GT, A2293 (half a 6AS7G so two per channel), 6080, 6AS7G, 6N13S and, and, and...don't remember but these latter tubes with external psu and adapters.

As you can understand there are a lot of possible combinations to tailor the sound of our small dots. I don't use 6080 or 6AS7G on a regular basis. They produce a lot of heat and I don't expect our dots to be able to take that in the long run. The very powerful 2 x A2293 per channel runs a lot cooler in spite of being equal to one 6080 or 6AS7G.

I have some favourite combinations that suit my mood and the music I play. I use a pair of Sennheiser HD-650 with a Zu Mobius cable and a Beresford Caiman SEG dac with Dorado psu enhancer and only play cd. I have enjoyed my experiments and still do and have some new adapters and tubes on their way to me. A sensible thing to do would be to put your money in a 'better' amp but that would be boooring. Just imagine how much I have experienced and learnt! And if I eventually want another amp I probably have a lot of good tubes for it already. But as for now the journey continues.


----------



## mordy

triod750 said:


> For input tubes I have used the common ones up to 6HM5 and C3g. With adapters but without external power supply I have used C3g but also EL42 and 6J5 types and 6C5 types. With external power supply and adapters I have also used different dual triodes as 6N7, 6SN7/6N8S, 12AU7/ECC82, 12AT7/ECC81/6201, E80CC, 6F8G and probably one or two other tubes.
> 
> For output tubes I have used 6N6P variants, 6N30Pi, different 6SN7GT, 6F8G, 5687, 6N8S, 6N12S, these without external psu and 6BX7GT, 6BL7GT, A2293 (half a 6AS7G so two per channel), 6080, 6AS7G, 6N13S and, and, and...don't remember but these latter tubes with external psu and adapters.
> 
> ...


I don't think an upgraded amp would be boring....
Many of the things that you have learned using your Little Dot MKIV SE will apply to other amps as well. As a previous owner of the Little Dot MKIII and having expiremented quite a lot with it I can tell you that no matter what tube combination you try, the amp has inherent limitiations as how far you can improve the sound. 
In order to take proper advantage of the possibilities that tube rolling offers with all the tubes you already own, you will need a more capable amp.
And if you decide to upgrade you are going to realize the sizeable improvements in sound - there is no turning back.


----------



## triod750

mordy said:


> I don't think an upgraded amp would be boring....


The amp in itself would not be boring, I agree on that. But my intention was to explore how far I could take this Little Dot. I have enjoyed the ride very much and so far I can not see 'the end'. But if the better amp would be the end, well, I'm not sure I would be satisfied by that. And even with a better amp there are even better amps out there. So you have to stop somewhere. I don't know whether a lot of people have listened to 6BX7 or A2293 with really good input tubes in Little Dot and know how this perform. I am sure there are amps designed for these tubes where they might sound even better but 'better' is a personal thing.

Eventually I might end up with a more capable amp - I probably will - but if I won't, I won't lose any sleep due to this. I enjoy my music and I enjoy my experiments. I have listened to a lot of capable loudspeaker amps, and own one or two, so I know what is possible in sound reproduction. I'm feeling good!


----------



## triod750

Right now I am listening to Arvo Pärt 'Summa' with 6J5GT/G as input (Brimar branded but Ken-Rad manufactured) and Brimar 6SN7GT as output. It feels as if it would be impossible to make it sound better. I know this is totally wrong but it is how it feels. And the 5687 I listened to the other day are too powerful for this kind of music. The music right now is engaging, involving and relaxed.

(I use the input tubes with adapters and with the amps own transformer. I use the output tubes with adapters and although I can use them with the amps own transformer I use the external psu since it seems to give the output tube just a little more sound quality. This might be my imagination though).

If my memory serves me, I paid EUR26 for the tubes.


----------



## mordy

triod750 said:


> Right now I am listening to Arvo Pärt 'Summa' with 6J5GT/G as input (Brimar branded but Ken-Rad manufactured) and Brimar 6SN7GT as output. It feels as if it would be impossible to make it sound better. I know this is totally wrong but it is how it feels. And the 5687 I listened to the other day are too powerful for this kind of music. The music right now is engaging, involving and relaxed.
> 
> (I use the input tubes with adapters and with the amps own transformer. I use the output tubes with adapters and although I can use them with the amps own transformer I use the external psu since it seems to give the output tube just a little more sound quality. This might be my imagination though).
> 
> If my memory serves me, I paid EUR26 for the tubes.


Yes, those prices were yesterday in time. A pair of Brimar 6SN7GT will set you back around $300 today...
I have been playing with tube amps for around twelve years now and it is really amazing how much the prices have gone up.


----------



## triod750

mordy said:


> Yes, those prices were yesterday in time. A pair of Brimar 6SN7GT will set you back around $300 today...
> I have been playing with tube amps for around twelve years now and it is really amazing how much the prices have gone up.


I think I bought these Brimar 6SN7GT two years ago and the 6J5GT/G early this year. But you are right, I could have found much more expensive siblings). I have an audio friend that has taught me to have patience when looking for tubes. 'Eventually something good will turn up'. His name is mordy  .


----------



## mordy

triod750 said:


> I think I bought these Brimar 6SN7GT two years ago and the 6J5GT/G early this year. But you are right, I could have found much more expensive siblings). I have an audio friend that has taught me to have patience when looking for tubes. 'Eventually something good will turn up'. His name is mordy  .


PP - patience pays!


----------



## Khitzi

Does anyone have any recommendations for power tubes on the Little Dot MK II?


----------



## triod750

Khitzi said:


> Does anyone have any recommendations for power tubes on the Little Dot MK II?


What sound qualities do you want from them? I am not familiar with MKII - what are the standard tubes for input and output?


----------



## Khitzi

triod750 said:


> What sound qualities do you want from them? I am not familiar with MKII - what are the standard tubes for input and output?


To be honest, I'm just looking for some general recommendations of where to start. I love the list on page 1 of this thread, but there's no info for the power tubes. This is my first tube amp so I'm just enjoying trying new tubes out. 

I'm using HD 800S, which I love for detail and soundstage. So I look for the tubes to add just a bit of body and warmth, but not so much that I lose lots of detail. Currently using some Mullard EF95 M8100 Ring Getter driver tubes, and they've warmed up the signature quite nicely. Just wondering what I can do with the stock power tubes now to see if I can improve it at all. 

The stock power tube is 2x 6N6 - came with some cheap Chinese ones as standard.


----------



## triod750

Khitzi said:


> To be honest, I'm just looking for some general recommendations of where to start. I love the list on page 1 of this thread, but there's no info for the power tubes. This is my first tube amp so I'm just enjoying trying new tubes out.
> 
> I'm using HD 800S, which I love for detail and soundstage. So I look for the tubes to add just a bit of body and warmth, but not so much that I lose lots of detail. Currently using some Mullard EF95 M8100 Ring Getter driver tubes, and they've warmed up the signature quite nicely. Just wondering what I can do with the stock power tubes now to see if I can improve it at all.
> 
> The stock power tube is 2x 6N6 - came with some cheap Chinese ones as standard.


I would recommend a pair of 5687 as an alternative to 6N6P. To me they give a bit more flesh to the sound. They need adapters. You can get them from that bay or from Deyan, I suppose. There are other alternatives but this is where I wish that I had started myself. In the same adapters you can use E182CC that Little Dot originally was designed for and delivered with a long time ago. These tubes have become very expensive and I haven't tried them myself since I took another path.
Mind you, we all have different ears so I leave no guarantee. If you become disappointed you could punish me by sending me your 800S. Just a suggestion .


----------



## triod750

Right now I listen to my Little Dot MKIVSE without external PSU. For input I use a pair of 6C5G, One of them arrived today and sounds good from the start. It is a BU version to some people:







It has a metal shield cover to prevent hum. This is soldered to pin number one (m). I could remove it but I won't. (BU means Butt Ugly. It could also mean BeaUtiful).

In the other channel is another 6C5G without such cover. I have used it for a while and it is beginning to sound good. It looks similar to this:





and there is no markings other than 6C5G. But the sound is there.

For outputs i use a Soviet near equivalent to 5687 that isn't very common and has become expensive; Melz 6N12S. This combination has taken me far from the original tubes in my amp. Today I would not recommend people to look for 6N12S when 5687 is available for much less. And to my ears, my 6J5GT/G pairs somewhat better with 5687 than these 6C5G. But 6C5 and 6J5 use the same adapter and can be had cheapish in different versions.

I have just tried a few different tubes from the 6C5 and 6J5 families and don't have any strong opinions. But I have fun.


----------



## TrollDragon

Khitzi said:


> To be honest, I'm just looking for some general recommendations of where to start. I love the list on page 1 of this thread, but there's no info for the power tubes. This is my first tube amp so I'm just enjoying trying new tubes out.
> 
> I'm using HD 800S, which I love for detail and soundstage. So I look for the tubes to add just a bit of body and warmth, but not so much that I lose lots of detail. Currently using some Mullard EF95 M8100 Ring Getter driver tubes, and they've warmed up the signature quite nicely. Just wondering what I can do with the stock power tubes now to see if I can improve it at all.
> 
> The stock power tube is 2x 6N6 - came with some cheap Chinese ones as standard.


The first part of the table on page 585 shows output tubes that we can use, some need external power supplies and most need adapters.  The eBay links in the table to the Powersocket adapters are long since dead, but there are other adapters available.
https://www.head-fi.org/threads/lit...e-rolling-guide.563884/page-585#post-11155053


----------



## triod750

Our Italian member @lupoal discussed the importance of correct heater voltage previously. I found this quote on this site tonight: .http://www.emissionlabs.com/datasheets/EML300B-25V.html

"*Heater Voltage:* Some people experiment with lower filament voltage, to expect better lifetime. This is essentially wrong to do. If the magic was that easy, we would make the tubes like this ourselves. Under Heating can lead to early loss of emission,  though new EML tubes will fully recover once the heater voltage is corrected, older tubes will recover only partially. The specified filament voltage at 0% tolerance is the one for best lifetime.  The voltage we specify,   is at the *TUBE PINS* itself.  Any voltage drop by the socket contacts must be compensated for.  For 2A3 tubes,  some sockets have 50mV voltage drop per pin, because the heater current of 2.5 Ampere is very high.    Causing a total drop of 0.1V for both pins together.   So a voltage of 2.6Volts at the socket pins is needed,  to make sure there is 2.5 Volts at the tube pins".

I have nothing to add to this due to lack of knowledge and experience. I don't know the magnitude of loss of lifetime, if so.


----------



## mordy

triod750 said:


> Our Italian member @lupoal discussed the importance of correct heater voltage previously. I found this quote on this site tonight: .http://www.emissionlabs.com/datasheets/EML300B-25V.html
> 
> "*Heater Voltage:* Some people experiment with lower filament voltage, to expect better lifetime. This is essentially wrong to do. If the magic was that easy, we would make the tubes like this ourselves. Under Heating can lead to early loss of emission,  though new EML tubes will fully recover once the heater voltage is corrected, older tubes will recover only partially. The specified filament voltage at 0% tolerance is the one for best lifetime.  The voltage we specify,   is at the *TUBE PINS* itself.  Any voltage drop by the socket contacts must be compensated for.  For 2A3 tubes,  some sockets have 50mV voltage drop per pin, because the heater current of 2.5 Ampere is very high.    Causing a total drop of 0.1V for both pins together.   So a voltage of 2.6Volts at the socket pins is needed,  to make sure there is 2.5 Volts at the tube pins".
> 
> I have nothing to add to this due to lack of knowledge and experience. I don't know the magnitude of loss of lifetime, if so.


In my Little Dot days, using external power supplies and voltage regulators, I used to measure the voltage at the tube pins. For power tubes there was always a drop, but not much. With 2.5A tubes the voltage regulator had to be set to 6.7V to get 6.3V at the tube pins with certain tubes.
Usually data sheets for a tube will show the specified voltage +- a percentage range.
https://frank.pocnet.net/sheets/049/6/6080.pdf
If you look at this data sheet for an RCA 6080 you will find the factory voltage specification 6.3V +-10%. That means that this tube will function according to factory specifications between 5.67V - 6.93V.
Perhaps certain tubes must be run at a very specific voltage without any variations, but IMHO all the tubes we normally use have a range where they perform according to factory specifications.
It seems to me to be unnecessary to fuss over minor voltage variations. Many people report using the same tubes for years without problems, and slight variations in the voltage are not going to affect tube life.


----------



## TrollDragon

Back in the day, tubes ran for years and years just off of a filament transformer. The AC mains voltage would fluctuate by 10% at times and the tubes kept right on going.  I think there might be a little too much worry over tube longevity.

Plug them in, turn them on and enjoy!  Keep a few spares on hand just in case one dies down the road.


----------



## triod750

TrollDragon said:


> Plug them in, turn them on and enjoy!


Most important part in this hobby!!


----------



## mordy

TrollDragon said:


> Back in the day, tubes ran for years and years just off of a filament transformer. The AC mains voltage would fluctuate by 10% at times and the tubes kept right on going.  I think there might be a little too much worry over tube longevity.
> 
> Plug them in, turn them on and enjoy!  Keep a few spares on hand just in case one dies down the road.


And while we are speaking about obsessing over tubes I would like to bring up something else - something that was a real insigt into measurements for me.
I discovered that I could not tell the difference in sound between tubes that measure just above good and tubes that measure as new. (I do not have a tube tester and have to rely on the values provided by the seller.)
A fellow headfier has a calibrated good quality tube tester, and he wrote that he bought eight tubes as NOS. When he measured them all were good, except for one. I asked him to pair the NOS tube with the one that did not measure good to see if he could hear a difference - to his great surprise they sounded the same.
There are headfiers that have used the same tubes for ten or even twenty years, and they still measure acceptable and work fine.
Perhaps there are very fussy amps where everything has to be just so, but IMHO most of the amps we use are not in that category.


----------



## TrollDragon

mordy said:


> And while we are speaking about obsessing over tubes I would like to bring up something else - something that was a real insigt into measurements for me.
> I discovered that I could not tell the difference in sound between tubes that measure just above good and tubes that measure as new. (I do not have a tube tester and have to rely on the values provided by the seller.)
> A fellow headfier has a calibrated good quality tube tester, and he wrote that he bought eight tubes as NOS. When he measured them all were good, except for one. I asked him to pair the NOS tube with the one that did not measure good to see if he could hear a difference - to his great surprise they sounded the same.
> There are headfiers that have used the same tubes for ten or even twenty years, and they still measure acceptable and work fine.
> Perhaps there are very fussy amps where everything has to be just so, but IMHO most of the amps we use are not in that category.


Exactly, and then there are the people that insist you have to have matched tubes. The only time matched tubes are required are for push pull output amps, these are power output tubes and need to be matched so you can bias them to have the same current draw, otherwise one of the tubes will be burning out long before the other.


----------



## mordy

TrollDragon said:


> Exactly, and then there are the people that insist you have to have matched tubes. The only time matched tubes are required are for push pull output amps, these are power output tubes and need to be matched so you can bias them to have the same current draw, otherwise one of the tubes will be burning out long before the other.


And I thought that matched tubes were required to increase profits for tube sellers - now I see that there is another reason lol...


----------



## TrollDragon

mordy said:


> And I thought that matched tubes were required to increase profits for tube sellers - now I see that there is another reason lol...


That too.


----------



## lupoal (Oct 29, 2021)

I’m going to upgrade my heaters power supply in these days… now it is based on LM317, I will add an additional stage and will become like a Teddy Pardo, I will do two of them, one per channel … to be honest I’ve no idea if that will improve the sound or not, I’m convinced the quality of power supply is a key factor for a good sound, in any case this is just a game for me giving me opportunity to discover something new

this is the circuit http://www.acoustica.org.uk/t/teddyreg.html


----------



## lupoal (Oct 29, 2021)

Khitzi said:


> Does anyone have any recommendations for power tubes on the Little Dot MK II?


input … C3g… or 6BE6 (Brimar or Telefunken )
output… 6SN7… with Mouse Ears 6BE6… 6H8C from Russia can be good too, unluckily in the last times seems they are crazy increasing prices too


----------



## triod750

lupoal said:


> I’m convinced the quality of power supply is a key factor for a good sound


You are probably right here, good enough is needed, but maybe that is mostly about the rest of the electrical operation and not that much about the heaters. Just a guess from me. But there is no reason for not making things better if you are capable of doing it. Just like tube rolling; it might not be neccessary but it can be fun.


----------



## lupoal (Oct 30, 2021)

tube rolling without proper power supply imho could be like put Ferrari engine inside a Zastava chassis… the engine could push more but the chassis is what it is

the power stage inside LD MK2, last hardware version, is not bad… one of my friends with big deep knowledge in electronic and hifi told me that the components used are not bad at all, capacitors for example are quite good… imho what could be better is the rectifier that is just a standard one instead of a scotky one, I’m going to install four bypass capacitors around that to improve, or to say better minimise, high frequency commutation noise coming from diodes inside (pass easily trough the filter capacitors in psu stage)

heaters… if you consider how bad is the transformer inside the LD (see my post with measured values) and the fact that the voltage from the wall in not stable over the time, unfortunately, the result is that the tube are probably not working at proper working point almost all the time… the quantity of heat produced not constant, not repeatable

the fact is that 6,3Vac are cheap … 6,3Vdc are more expensive, more complicate, require space and dissipate some heat in the psu… in short are not compatible with target selling price for products like LD Mk2 

p.s. sorry for boring speeches… I promise, next time I will post picture about my new, but NOS, Mouse Ears… quite rare tubes… slurp


----------



## triod750

lupoal said:


> p.s. sorry for boring speeches…


Not boring at all. All contributions are welcome, at least in my opinion. I cannot comment on LDMKII, neither on unstable voltage from the wall since I have utterly stable voltage and a MKIV. I don't doubt that upgrading an amp might be beneficial if there are problems of one kind or another. Some are of the opinion that it is more reasonable to get a better amp from the start. Pushing the limits with what you have has always been interesting to me. I am a clever fellow who realises that it is better for me to keep my hands off from the innards of my amp. But I welcome your reports from your endeavours. Posts like these makes it interesting to visit the thread.


----------



## Freia (Nov 3, 2021)

Hello, I've bought the LD I+ a week ago, and I am having a blast playing around with it.
Seems that this thread is quite inactive and as a layman I would like to share some initial impressions.

Tubes I got are the GE JAN 5654W and Voshkods, there really is no reason using the stock Chinese tubes.
While the original one was decent, I also rolled the op amp with two OPA445BM-1. One thing I find interesting is that when you turn on the amp, a faint pop is heard, and when I changed the op amp, the pop was louder and distinct.
The high and low gain switch is confusing too as the manual's description and the amp is in fact reversed. I didn't realized I was on high gain for the first few hours and to this day I am still not 100% sure if I am correct about the settings.

One flaw I do find is the pot. As the amp is loud I normally have the knob under 20, however there are times I need to dial it down and the left channel will be silent. I see people recommend upgrading it to a Alps, but I'm a total noob to DIYing and was wondering if it can be done. Are there any alternative pots that are the same size as the stock ones?


----------



## triod750

I read a good post in another thread here on head-fi and want to share it on this tube rolling thread: https://www.head-fi.org/threads/woo-audio-amp-owner-unite.428570/post-16644158


----------



## Deleeh

Hello,
Is there anything new for the Little Dot 1+?

Yes, there is. After the repair months ago, it runs mostly stable and normal and better than ever before.
I have no problems with the temperature, after x hours of listening it stays warm to the touch.
So the repair was worth it.

The second point.
By chance I got a set of Lm Ecrission W403B tubes.
And it's really divine to listen to music with them.
Great tubes, the best I've had so far, which I don't think will be topped.
The Ef 92 Brimar were already relatively good, but the Ecrisson are a good deal better in all areas of music.
So if anyone sees them, go ahead and pair them with the Little Dot 1+.
Just don't forget to remove the two dip switches if you haven't switched to Ef 95.
Also, the Little Dot remains stable through the conversion.

In summary, the small investment in the LD1+ was in all respects a huge advantage and leap forward that can be recommended.


----------



## mordy

Deleeh said:


> Hello,
> Is there anything new for the Little Dot 1+?
> 
> Yes, there is. After the repair months ago, it runs mostly stable and normal and better than ever before.
> ...


Good to hear everything worked out! - I know the crummy feeling when your equipment isn't working or waiting to be fixed...


----------



## lupoal

… not the Mouse Ears as promised (next time) but a very nice sounding couple of Shuguang when matched with Fivre 6BE6 (not sounding so well with C3g)


----------



## lupoal (Nov 17, 2021)

a little update… the Shuguang with Voshkod 6ZH1P-EV… tried today just for curiosity, to see if the russian tubes were able to add a little more light and… wow… simply fantastic combo! prefect with piano… church organ… strings…  voices… chorus… details, light, air and depth, texture and very good low register, space between instruments, head stage … considering how cheap is this combo I’m really surprised… in my set (sennheiser HD580 with DIY 7N cable based on American patent) this combo can easy compete with other solutions (and set) much more expensive…


----------



## stuntmanx8 (Dec 22, 2021)

On my Little Dot2 tube roll.
 Voshkod 6ZH1P-EV military are amazing. I upgraded just now from the GE JAN 5654w which were a killer upgrade from the factory chineese tubes. I was able to track down a matched pair of the Voshkod's from 1976! People say these open up after a good burn in, but I can already tell the amazing quality over my GE's right out of the box...... If these do in fact open up more, my jaw will drop because these are about the best sounding valves I have ever heard on this amp. The lows are punchy and solid, the mids are crystal clear and the highs are right there in the front. Just killer all around. I guess my JANS are now the back ups.
Now I'm still waiting on the Russian 6N6P Gold grid power finals to show up from Romania!
I would like to hear if anyone has a better combo.


----------



## triod750

stuntmanx8 said:


> I would like to hear if anyone has a better combo.


Congratulations. As long as you are pleased with what you have you should just enjoy. What others have is just irrelevant. Comparison is difficult.


----------



## Whelkie D

stuntmanx8 said:


> On my Little Dot2 tube roll.
> Voshkod 6ZH1P-EV military are amazing. I upgraded just now from the GE JAN 5654w which were a killer upgrade from the factory chineese tubes. I was able to track down a matched pair of the Voshkod's from 1976! People say these open up after a good burn in, but I can already tell the amazing quality over my GE's right out of the box...... If these do in fact open up more, my jaw will drop because these are about the best sounding valves I have ever heard on this amp. The lows are punchy and solid, the mids are crystal clear and the highs are right there in the front. Just killer all around. I guess my JANS are now the back ups.
> Now I'm still waiting on the Russian 6N6P Gold grid power finals to show up from Romania!
> I would like to hear if anyone has a better combo.


You should find the Russian 6N6 will add something to the sound, although not quite as much as the driver tubes. I am running the same combination at the moment. Whether or not it is a "better" combo or not, but I also like the Yugoslavian 6HM5s (tall version) for an interesting alternative sometimes. Happy listening!


----------



## lupoal (Dec 24, 2021)

@stuntmanx8
6N6P… well probably I have 8 -10pcs of them, 3 - 4 different manufactures and production date... they are all just nice, nothing really special (imho)… they drain a lot of current and transfer heat to the amp body

if you really want to have an upgrade buy/build an adapter 6N6P to 6SN7… then do not search for white unicorn, just a good Russian NOS tube is fine and cost few bucks… or GE… or Sylvania… Tungsol are, imho, too light and doesn’t match well with Voshkod… RCA are also nice, a little slow and fat… the modern Chinese are good too, probably not the same quality as the nos from Russia and not the same expected life time, but modern sound fast and with punch, and cheap

but before of all a couple of 6H8C, the older the better, for few bucks


----------



## Whelkie D (Dec 26, 2021)

Can anyone help? I am running my LD MK2 through my amp. I have a NAD 320 and have the LD between the Pre-out and Main-in which seems to work fine. Discovered last night that if I turn the LD off while leaving the amp and source playing, the sound fades away as you would expect, and then comes back and carries on being audible. Left it like this for an hour or so as I thought it may just be some residual current left in the LD, but it just carries on. Does this mean the LD is doing nothing when it is actually turned on? Totally confused now. Thanks for any explanations.


----------



## Freia

After much contemplating on a pair of 6HM5 for my Ld I+, I bit the bullet and ordered a pair of C3g instead. Talk about impulsive buy, lol. 
Now browsing for a set of adapters on Ebay, I find two options, the expensive ones that most people have in there pictures, and a much cheaper one sold by tubemalls. 
Is there any reason to not choose the cheaper ones aside from aesthetic reasons?


----------



## TrollDragon (Dec 28, 2021)

Whelkie D said:


> Can anyone help? I am running my LD MK2 through my amp. I have a NAD 320 and have the LD between the Pre-out and Main-in which seems to work fine. Discovered last night that if I turn the LD off while leaving the amp and source playing, the sound fades away as you would expect, and then comes back and carries on being audible. Left it like this for an hour or so as I thought it may just be some residual current left in the LD, but it just carries on. Does this mean the LD is doing nothing when it is actually turned on? Totally confused now. Thanks for any explanations.


The local negative feedback gain stage is allowing the music to pass through from your source.

This is the gain circuit in my LD MK IV and should be very similar in your MK II, the red line is the way the audio is getting through when the LD is off. There should be a difference in the audio level coming out of your speakers when the LD is on or off.


----------



## Deleeh

Whelkie D said:


> Can anyone help? I am running my LD MK2 through my amp. I have a NAD 320 and have the LD between the Pre-out and Main-in which seems to work fine. Discovered last night that if I turn the LD off while leaving the amp and source playing, the sound fades away as you would expect, and then comes back and carries on being audible. Left it like this for an hour or so as I thought it may just be some residual current left in the LD, but it just carries on. Does this mean the LD is doing nothing when it is actually turned on? Totally confused now. Thanks for any explanations.


Hello,
Yes of course now that @TrollDragon says it.
To put it simply the Little Dot loops the signal which is normal.
That means you can listen to music and the signal goes through it whether it is on or off.

I didn't really understand what you meant from your wording.
But with the sketch and text from Trolldragon it was clear.

So there is nothing to worry about.


----------



## Whelkie D

TrollDragon said:


> The local negative feedback gain stage is allowing the music to pass through from your source.
> 
> This is the gain circuit in my LD MK IV and should be very similar in your MK II, the red line is the way the audio is getting through when the LD is off. There should be a difference in the audio level coming out of your speakers when the LD is on or off.
> 
> ...





Deleeh said:


> Hello,
> Yes of course now that @TrollDragon says it.
> To put it simply the Little Dot loops the signal which is normal.
> That means you can listen to music and the signal goes through it whether it is on or off.
> ...


Thank you so much for the replies. It makes sense now and has reassured me that all is OK. I guess it is just something that I had never noticed before, so started to panic! I now need to go and have a whisky and calm down!


----------



## Deleeh

Whelkie D said:


> Thank you so much for the replies. It makes sense now and has reassured me that all is OK. I guess it is just something that I had never noticed before, so started to panic! I now need to go and have a whisky and calm down!


Sounds good.
I would also have a glass of whisky with it.😁
Hope it's a good bottle.


----------



## Whelkie D

Deleeh said:


> Sounds good.
> I would also have a glass of whisky with it.😁
> Hope it's a good bottle.


Yes, a single cask Laphroaig matured in a port cask!


----------



## Deleeh

Oouu is a good Bottle,cheers 😉.


----------



## dany9107

Hi, I should buy some power tubes for my Little Dot Mk3. What do you recommend? Could you recommend some links, I've seen dozens of 6N6P tube listings on eBay.


----------



## mordy

dany9107 said:


> Hi, I should buy some power tubes for my Little Dot Mk3. What do you recommend? Could you recommend some links, I've seen dozens of 6N6P tube listings on eBay.


Buy adapters and then get the least expensive 6SN7 tubes you can find - will sound better than any 6N6 tubes.


----------



## dany9107

mordy said:


> Buy adapters and then get the least expensive 6SN7 tubes you can find - will sound better than any 6N6 tubes.


Could you link the whole thing to me?  I am quite inexperienced on power tubes, I would pair them with Mullard M8100.


----------



## sghound (Jan 12, 2022)

dany9107 said:


> Could you link the whole thing to me?  I am quite inexperienced on power tubes, I would pair them with Mullard M8100.


search sovtek 6sn7 on ebay. use the appropriate plug in adapter also from ebay. also mullard cv4015 nos on ebay. this is way better than the 8100. just remember to switch the jumpers to ef92.

this is way.


----------



## mordy

sghound said:


> search sovtek 6sn7 on ebay. use the appropriate plug in adapter also from ebay. also mullard cv4015 nos on ebay. this is way better than the 8100. just remember to switch the jumpers to ef92.
> 
> this is way.


From memory this adapter should work, but I need somebody to confirm it:
https://www.ebay.com/itm/202978063457?hash=item2f426f7461:g:1SoAAOSwMmBV2wGi
You will need two such adapters.


----------



## mordy

mordy said:


> From memory this adapter should work, but I need somebody to confirm it:
> https://www.ebay.com/itm/202978063457?hash=item2f426f7461:g:1SoAAOSwMmBV2wGi
> You will need two such adapters.


Here is a listing of 6SN7 tubes or equivalents - no need to spend big bucks:
https://www.ebay.com/sch/i.html?_from=R40&_trksid=p2047675.m570.l1313&_nkw=pair+6SN7+tube&_sacat=0


----------



## MIKELAP

Or these  https://www.ebay.ca/itm/202978079369?hash=item2f426fb289:g:hwEAAOSwiLdV951Y


----------



## sghound

dany9107 said:


> Could you link the whole thing to me?  I am quite inexperienced on power tubes, I would pair them with Mullard M8100.


6sn7gt x 2 https://www.ebay.com/itm/373642870224?hash=item56fed9bdd0:g:bgsAAOSwdDVg5xQk&LH_BIN=1

adapters x 2 https://www.ebay.com/itm/191082281033?hash=item2c7d643849:g:7TMAAOSwYHxWLiMM&LH_BIN=1

cv4015 x 2 (change the internal jumpers to ef92) https://www.ebay.com/itm/3103913810...sh=item4844c49c50:g:KWgAAOSwdfdhqMQA&LH_BIN=1

END GAME SONIC HEAVEN SORTED.


----------



## dany9107

Thanks to everyone for your help, could my current 6N6Ps be consumed given the significant decrease in volume?


----------



## Freia (Jan 15, 2022)

Hi, are there any veterans with experience on C3g?
The adapters I ordered arrived in terrible shape. As you can see I was able to straighten the pins but not much I can do with the base. It was difficult to get the tubes in place, and having read horror stories of C3g cracking at the base, I was hesitant to use too much force. This is the most I can do( 2nd pic), but the pins are still visible and the center loctal isn't fully locked in place.
I've tried widening the center but to no avail . Should I brute force it or is removing the metal in the center hole a good idea?


----------



## triod750

I would return them and try these instead https://www.ebay.com/itm/2013669743...L%2FNI9NGl4OSHja|clp:2334524|tkp:BFBM5OPE1Mtf

Not everyone agree but mine are perfect. Listen also to other suggestions...


----------



## Whelkie D (Jan 15, 2022)

MIKELAP has done a really good tutorial on home made C3G adapters on this page 553 of this thread.


----------



## Freia (Jan 15, 2022)

Well as long the adapters are functional, I'm okay with them being squished. That aside, the seller was reputable as they were brought up a few times in this thread, so I was wondering if I am doing something wrong when assembling the tubes.
*update: Initially I thought it is the center hole that was too tight, but after prying out the metal in the center I realized its the pins that didn't fit.


----------



## MIKELAP (Jan 15, 2022)

Freia said:


> Hi, are there any veterans with experience on C3g?
> The adapters I ordered arrived in terrible shape. As you can see I was able to straighten the pins but not much I can do with the base. It was difficult to get the tubes in place, and having read horror stories of C3g cracking at the base, I was hesitant to use too much force. This is the most I can do( 2nd pic), but the pins are still visible and the center loctal isn't fully locked in place.
> I've tried widening the center but to no avail . Should I brute force it or is removing the metal in the center hole a good idea?


Personnally i always found those adapters dangerous since there's no protection against electric shock if you touch them ,i would rather get  these(picture) that are way better quality  .Also as you  know dont wiggle them when inserting them and ounce they are in leave them in the adapter its the safest thing to do. Maybe center pin in adapter should be bent so the tube could slide in ?


----------



## triod750

I agree, the adapter on the attached photo is robust and safe.


----------



## Freia (Jan 15, 2022)

Thanks to you guys it's finally in!
In the end I pressed real hard, applying pressure straight down without wiggling the tubes. Guess I was too scared of it breaking. MIKELAP is right though, one shouldn't skimp on quality adapters.
So here it is, my LD I+ in all its glory. Looks wonky AF but apart from aesthetics goes, it works.


----------



## Deleeh

Do not buy sockets from China.
They are not worth the money.
I bought the same ones as socket savers for 6SN7 and they were really crappy.
The tube wobbled at the top so it wasn't nice and made noise.
When I removed the socketsavers, there was no more noise and everything was fine again.


MIKELAP said:


> Personnally i always found those adapters dangerous since there's no protection against electric shock if you touch them ,i would rather get  these(picture) that are way better quality  .Also as you  know dont wiggle them when inserting them and ounce they are in leave them in the adapter its the safest thing to do. Maybe center pin in adapter should be bent so the tube could slide in ?


----------



## triod750

Deleeh said:


> Do not buy sockets from China.
> They are not worth the money.
> I bought the same ones as socket savers for 6SN7 and they were really crappy.
> The tube wobbled at the top so it wasn't nice and made noise.
> When I removed the socketsavers, there was no more noise and everything was fine again.


I don't agree. You can buy either good adapters or bad adapters from anywhere. My first adapters were from China; C3g to 6AK5 as previously shown, and 6SN7 to 6N6P/ECC88/6CG7 etc. I have rolled a lot of tubes and these are good. Nowadays I buy my adapters from @Deyan , member of this forum and they are superb. My comment was based on that @Freia  is based in Taiwan. That is very close to China - maybe too close. But @Deyan is a great source who makes custom adapters for almost anything you want to try. He has also built an adapter so I can use a dual triode for input and a power supply for using more power hungry tubes than Little Dot can handle.




The photo shows a prototype.




This photo shows a collection of some adapters and also the power supply for power hungry heaters.


This adapter makes it possible to use two A2293/CV4079 in the 6N6P socket. (You need two of them).

Just a few examples of what I have bought from him.


----------



## MIKELAP (Jan 15, 2022)

triod750 said:


> I don't agree. You can buy either good adapters or bad adapters from anywhere. My first adapters were from China; C3g to 6AK5 as previously shown, and 6SN7 to 6N6P/ECC88/6CG7 etc. I have rolled a lot of tubes and these are good. Nowadays I buy my adapters from @Deyan , member of this forum and they are superb. My comment was based on that @Freia  is based in Taiwan. That is very close to China - maybe too close. But @Deyan is a great source who makes custom adapters for almost anything you want to try. He has also built an adapter so I can use a dual triode for input and a power supply for using more power hungry tubes than Little Dot can handle.
> 
> 
> The photo shows a prototype.
> ...


Looks familiar lol  .Here are a few i made


----------



## triod750

MIKELAP said:


> Looks familiar lol  .Here are a few i made


Absolutely. You were the inspiration. I tried to contact you to discuss it but failed to come through. You probably never noticed my PM. You are always very helpful like a few other veterans.


----------



## aviationwiz

Would this adapter work to use the 6SN7 on a LD Mk2? Using “option 3” on the listing? Otherwise, does anyone know of where to grab some good adapters from? Thanks!

12SN7 / 6SN7 TO 12AU7 / 6922


----------



## TrollDragon (Jan 19, 2022)

aviationwiz said:


> Would this adapter work to use the 6SN7 on a LD Mk2? Using “option 3” on the listing? Otherwise, does anyone know of where to grab some good adapters from? Thanks!
> 
> 12SN7 / 6SN7 TO 12AU7 / 6922


No, those will not work.
I must have missed the Option 3 part when I first looked at the ad. Yes, if it is wired 6SN7 to 6922 then that adapter will work.

Or

You need a 6SN7 to 6CG7/6FQ7 adapter.
https://www.ebay.com/itm/201115946751


----------



## FinHifi

Has someone tried 6k4 and voskhod tubes ? Would like to have a comparison


----------



## triod750

FinHifi said:


> Has someone tried 6k4 and voskhod tubes ? Would like to have a comparison


Do you mean these 6k4 http://www.r-type.org/exhib/abh0213.htm ?

And since Voskhod was a factory, what tubes do you mean? They made plenty  .


----------



## FinHifi

triod750 said:


> Do you mean these 6k4 http://www.r-type.org/exhib/abh0213.htm ?
> 
> And since Voskhod was a factory, what tubes do you mean? They made plenty  .


6ZH1P-EV  is the type, i tought that voskhod was the tubes name  im newbie when it comes to tubes


----------



## triod750

That tube type could be a good starting point. Give yourself plenty of time to get to know its sound signature before you try something else. This tube is said to develop with time, meaning that its sound incrementally changes and gets better with use. Take your time and decide for yourself whether you agree or not.

Enjoy! We all were new once.


----------



## califmike33 (Feb 26, 2022)

Wow am i late to this party 856 pages.  Just bought this amp for my first tube amp, yeeeeeeee.  So i have the Hd 6xx and looking to do some tube rolling, is there any one set that really stands out ?   I have one other question how is this amp for a pre amp ?  thanks guys this is going be fun.

So what tubes would i get for the ultimate sound package on this amp ? any suggestions ?


----------



## califmike33

Wow guess this thread is dead no replies ???????????


----------



## jonathan c

Which Little Dot do you have?


----------



## califmike33

Little Dot Mark ii


----------



## jonathan c

For the 6N6 tubes, an upgrade would be Foton 6N6P tubes. For the 6J1 tubes, a good ‘roll’ would be the GE 5654s.


----------



## califmike33 (Feb 28, 2022)

* Voshkod 6ZH1P-EV  Would these work ?  I will check those tubes you recomended, thanks.  Was reading on the first page of this thread about all the tubes and how they sound, do those apply to my Mark ii ?

Cant find the Foton 6N6P, I found the GE 5654*


----------



## jonathan c

califmike33 said:


> * Voshkod 6ZH1P-EV  Would these work ?  I will check those tubes you recomended, thanks.  Was reading on the first page of this thread about all the tubes and how they sound, do those apply to my Mark ii ?
> 
> Cant find the Foton 6N6P, I found the GE 5654*


Those specific Voshkod will be fine for LD Mk-II. For the Fotons, you will have to wait. Most sellers are in Russia or in the Ukraine…


----------



## califmike33

Thanks for your reply can you suggest something else beside the Fotons, Russia and Ukraine could be a long wait with the war, any other tubes what could replace the Foton ? and thank you very much for your help.


----------



## jonathan c

califmike33 said:


> Thanks for your reply can you suggest something else beside the Fotons, Russia and Ukraine could be a long wait with the war, any other tubes what could replace the Foton ? and thank you very much for your help.


Here is one Russian brand of 6N6P at the Tube Store.


 (The 6N6P is a Soviet design that has no equivalent. A 6N6P can only be replaced by a 6N6P albeit a different brand).


----------



## califmike33

Got it thanks, so im set i will getthe Novosibirsk and the Voskhod Red Rockets 6ZH1P-EV and i should be set for my first roll.  I think it should improve the sound.  Thanks again for all your help.


----------



## FinHifi

califmike33 said:


> Got it thanks, so im set i will getthe Novosibirsk and the Voskhod Red Rockets 6ZH1P-EV and i should be set for my first roll.  I think it should improve the sound.  Thanks again for all your help.


Just got my voskhod 6j1p-ev and swapped out my 6k4 tubes from fxaudio-tube and those are really good sounding, mellow compared to 6k4.
​


----------



## califmike33

Mine are on the way based on the first page on this thread which is very good in the description of all the tubes those sound like the best tubes for my type of sound.

Hope you enjoy them don't they take time to break in?


----------



## califmike33

I guess my biggest concern is is this amp strong enough to drive the Sennheiser HD 6xx?


----------



## sghound

califmike33 said:


> Little Dot Mark ii


read page 855 for latest clues


----------



## triod750

I'm right now listening to a pair of General Electric 5687 for output using adapters from Chinese xulingmrs on eBay: https://www.ebay.co.uk/itm/193442943917?hash=item2d0a1913ad:g:c5AAAOSwV0RXtEY6

For input I am using a pair of JAN-CKR-6C5 using adapters from @Deyan , member of this forum. (I already had the Chinese 5687 adapters when I ordered my first adapters from him). They look like these and complement the GE 5687 tubes very well:




The tubes I use were made by Ken-Rad during the war. RCA made are probably easier to come by.

Adapters from Deyan that takes either 6J5 or 6C5 type tubes (a lot of these to choose from):





I have experimented with an awful lot of tubes in my Little Dot, albeit a MKIVSE. If I weren't an adventurous person I could easily have stopped when I had reached this level. But for the music, the amp is dead silent and the music is presented in a very balanced way. Genuine Ken-Rad tubes are known for their good bass. 5687 tubes has a beautiful glow that compensates for the secret glow of the input metal tubes. 5687 is an underrated tube compared to a lot of expensive tubes.

Just take this as information, meant to make you curious. I don't make recommendations anymore - at least I try not to. But if you absolutely need a recommendation you can use it as such. The choice is yours.


----------



## califmike33

Latest clues i should be using adapters and other tubes.  Got tubes today and amp comes tomorrow will post my findings.


----------



## califmike33 (Mar 3, 2022)

Got my amp today and tried the stock tubes and messed with the jumpers.  I then put my Russian tubes in and i hear a little differance, i wouldnt say dramatic, but subtle.  I thought the tube sound took off the edge and shapness, im still getting sharp highs.


----------



## TrollDragon

califmike33 said:


> Got my amp today and tried the stock tubes and messed with the jumpers.  I then put my Russian tubes in and i hear a little differance, i wouldnt say dramatic, but subtle.  I thought the tube sound took off the edge and shapness, im still getting sharp highs.


You will probably need to try quite a few different driver tubes to find some that have a good synergy with what ever headphones you are using.


----------



## califmike33

Oh really ok thanks, have to see what other driver tubes are out there.


----------



## TrollDragon

califmike33 said:


> Oh really ok thanks, have to see what other driver tubes are out there.


We have all rolled a tube or two in our amps to find the best...  






My favorite tube for the past 7 years with my DT880s has been the Yugoslavian EI 6HM5 tall version. 

The chances of getting a pair out of Serbia anytime soon might be quite difficult though.
https://www.ebay.com/itm/401082139160


----------



## triod750 (Mar 4, 2022)

To be honest, I don't regret that I have tried many other tubes in my Dotty. It's possible to elevate these amps to a higher level with a 'fuller' sound. Right now I am listening to one Sylvania 6SN7W and one Sylvania 7N7 as output tubes and the sound quality is much higher than with GE 5687 but so can the price be. (These two specimens are actually the same tube with different pinout and I have been lucky to find them for cheap). For inputs I use Sylvania 6C5GT which is slightly warmer than Ken-Rad 6C5.

Another way to reach the same SQ could be to buy a better amp...


----------



## califmike33

Yeah you got a crazy amount of two and I can definitely get into tube rolling.  I got to say my first roll with the ones I bought over the stock made quite a bit of difference not major but definitely noticeable and I'm going to listen to him closer let him get burned in and see if there's anything that I don't like about the sound.

But I'm still learning about where to set the gain because it comes on the lowest setting which I had to turn my amp up to 3:00 to get enough volume I've moved it up to the third setting which definitely made a difference but from what I hear each game is going to give you a little bit different sound so I may play with some of the other games and see what it does it just kind of sucks that the gain you have to open up the case.


----------



## triod750

It is a good idea to get to know the amp with cheap and easily available tubes before moving forward. Tubes also often needs to be used for quite a while before performing their best. Don't rush anything - take your time with incremental changes that you thoroughly evaluate before making next change...


----------



## califmike33 (Mar 4, 2022)

Well i just got a new dac SMSL D300 and im playing with optical out of my computer soundcard to dac, or usb from computer and bypass computer soundcard and go directly usb into dac.

I will say im enjoying my amp and sound, one thing is it seems a little underpowered for my HD 650, im one setting below the max gain, i may try max gain but i hear people say it gets noisy, hissy, one wish is this thing had a little more kick.


----------



## califmike33

Well im back again and after several days of listing i have to say this amp is under powered for HD 6xx just aint enough kick for me.  Thinking about moving up to something more powerful.  I love the sound but the kick aint there.  Any suggestions of a stronger amp under 500 us dollars ?


----------



## TrollDragon

califmike33 said:


> Well im back again and after several days of listing i have to say this amp is under powered for HD 6xx just aint enough kick for me.  Thinking about moving up to something more powerful.  I love the sound but the kick aint there.  Any suggestions of a stronger amp under 500 us dollars ?


My Little Dot MK IV puts out 500mW @ 300Ω and will push my DT880 (250Ω) too loud anywhere past 12:00 on the volume dial. I'm using a gain of 5 on the amp.  The Mk 2 is only 300mW @ 300Ω and your HD6XX are actually easier to drive than the beyers.

Under $500 I would suggest the XDuoo TA-26, the Darkvoice 336SE or the Little Dot MK IV.


----------



## califmike33

Thank you I was looking at the ta-26 to me that things ugly looking I wouldn't want that on my desktop but I've heard excellent things about it.  I guess I could turn my little dot mark 2 up to the highest gain and see if that helps.


----------



## mab1376

califmike33 said:


> Well im back again and after several days of listing i have to say this amp is under powered for HD 6xx just aint enough kick for me.  Thinking about moving up to something more powerful.  I love the sound but the kick aint there.  Any suggestions of a stronger amp under 500 us dollars ?


The Jotunheim 2 and a balanced cable (dont need a balanced dac for this) has really good slam.


----------



## califmike33

I have a balanced DAC is that jottenheim a tube amp?


----------



## mab1376 (Mar 6, 2022)

califmike33 said:


> I have a balanced DAC is that jottenheim a tube amp?


Oh no, sorry didn't realize that was a requirement. Not sure offhand, but anything that uses 6080/6as7 power tubes should give the effect you want. It might be hard to find under 500, though. Trolldragon's suggestions look good. Never tried an XDuoo Amp first hand, but I've seen good reviews.


----------



## califmike33 (Mar 6, 2022)

Yeah Xduoo TA-26 cant find a bad review on it, hard for me to get past the looks of it.  Im thinking Xduoo 26 spanks little dot mark ii.  Wonder if the little dot tubes will work on Xduoo 26.


----------



## jonathan c

TrollDragon said:


> My Little Dot MK IV puts out 500mW @ 300Ω and will push my DT880 (250Ω) too loud anywhere past 12:00 on the volume dial. I'm using a gain of 5 on the amp.  The Mk 2 is only 300mW @ 300Ω and your HD6XX are actually easier to drive than the beyers.
> 
> Under $500 I would suggest the XDuoo TA-26, the Darkvoice 336SE or the Little Dot MK IV.


I agree - especially with the Xduoo TA-26 recommendation for the HD6XX (and other h/p with impedance of 250+ ohms).


----------



## TrollDragon

califmike33 said:


> Yeah Xduoo TA-26 cant find a bad review on it, hard for me to get past the looks of it.  Im thinking Xduoo 26 spanks little dot mark ii.  Wonder if the little dot tubes will work on Xduoo 26.


No the tubes on the TA-26 are different.


----------



## califmike33 (Mar 7, 2022)

Bummer about the tubes the tubes are non returnable so I'll have to put the money eBay.

Let me know if anybody's interested in some Russian tubes for this amp real cheap I'm getting rid of them.


----------



## califmike33

Well Well i put the amp on the hightest setting before i was going to give up on it.  Now it has more power and volume, but seems like more distortion, im playing with it for a few days before i totally give up.

Are there any internal mods you can do to improve sound quality ?


----------



## FinHifi

califmike33 said:


> Well Well i put the amp on the hightest setting before i was going to give up on it.  Now it has more power and volume, but seems like more distortion, im playing with it for a few days before i totally give up.
> 
> Are there any internal mods you can do to improve sound quality ?


https://www.head-fi.org/threads/little-dot-mk-iii-mods.439449/

Nothing too simple.


----------



## TrollDragon

califmike33 said:


> Well Well i put the amp on the hightest setting before i was going to give up on it.  Now it has more power and volume, but seems like more distortion, im playing with it for a few days before i totally give up.
> 
> Are there any internal mods you can do to improve sound quality ?


I found gain 10 way to noisy to be anywhere useful.  There are literally pages and pages of happy HD650/6XX LDMK2 owners out there so It's boggling as to why it doesn't supply enough power for your pair.  Have you tried a different source than the SMSL?


----------



## Shane D

Anybody here using the Mark 9? I got rid of the Mark III a few months ago, but I was really surprised with how well it handled my Grado's. I was wondering if the Mark 9 would do well with a few different pairs of efficient headphones?


----------



## triod750

I use HD650 with my LD MKIV and have never felt that they are underpowered. Maybe this depends on source and choice of music, I don't know. My source is a CD-player (!). Lower register in a grand piano is very demanding...
I don't listen to a lot of rock music so I can't compare.
Original tubes, though, left me disappointed.


----------



## mab1376 (Mar 10, 2022)

triod750 said:


> I use HD650 with my LD MKIV and have never felt that they are underpowered. Maybe this depends on source and choice of music, I don't know. My source is a CD-player (!). Lower register in a grand piano is very demanding...
> I don't listen to a lot of rock music so I can't compare.
> Original tubes, though, left me disappointed.


Yeah, a true 2v source will make an impact on perceived loudness, and the gain jumpers on the amp too, I have mine set at 5 out of 10 and with stock (EH 6h30Pi, and an upgraded AEG 6AK5W) and custom (C3Gs and 6SN7) both sound great and 10/10 on the volume knob is ear-bleeding with my HD650.

Unrelated:
Preamp out seems to be unbalanced now (left sounds louder) after 10 years of owning it some caps may be dying. Headphone out still seems fine.


----------



## TrollDragon

mab1376 said:


> Unrelated:
> Preamp out seems to be unbalanced now (left sounds louder) after 10 years of owning it some caps may be dying. Headphone out still seems fine.


It might be a dirty or loose connection on your RCA cables at either end.  
The preamp out RCAs and the headphone jack are actually wired in parallel, there are no extra components in the preamp out circuitry.


----------



## mab1376

TrollDragon said:


> It might be a dirty or loose connection on your RCA cables at either end.
> The preamp out RCAs and the headphone jack are actually wired in parallel, there are no extra components in the preamp out circuitry.


The terminal in the rear for output doesn't look any worse than the one used for input, I used straight wire musicable II cables for inputs and outputs. I see what you mean by parallel, I popped off the from and rear panel and all solder points look good with very minimal corrosion. So not sure what it could be.


----------



## TrollDragon

mab1376 said:


> The terminal in the rear for output doesn't look any worse than the one used for input, I used straight wire musicable II cables for inputs and outputs. I see what you mean by parallel, I popped off the from and rear panel and all solder points look good with very minimal corrosion. So not sure what it could be.


If you swap the L/R RCAs does the louder sound still stay on the Left?


----------



## mab1376

TrollDragon said:


> If you swap the L/R RCAs does the louder sound still stay on the Left?


I'd have to plug it back in and check, it was pumping into my Jotunheim 2 at the time.

My new WA22 has taken it's place on the desk


----------



## Shane D

mab1376 said:


> I'd have to plug it back in and check, it was pumping into my Jotunheim 2 at the time.
> 
> My new WA22 has taken it's place on the desk


That is Quite an upgrade!


----------



## mab1376

Shane D said:


> That is Quite an upgrade!


Was on my wishlist since 2012, so finally pulled the trigger on it!

My MK IV SE will be moved into my bedroom hooked to a Fiio BTR5


----------



## TrollDragon

mab1376 said:


> My new WA22 has taken it's place on the desk


Very Nice!


----------



## Shane D

Not tube related except that I just got my tube amp, the Little Dot MK9.





I was surprised that the power tubes are from France?


----------



## Shane D

Not tube related except that I just got my tube amp, the Little Dot MK9.




I was surprised that the the power tubes are from France?


----------



## mordy

Shane D said:


> Not tube related except that I just got my tube amp, the Little Dot MK9.
> 
> 
> 
> ...


Thomson power tubes - I guess the manufacturer has stock of these (originally I think they wanted to supply RCA 6080).
I am very curious how this amp sounds - please let us know your initial impressions!


----------



## Shane D

mordy said:


> Thomson power tubes - I guess the manufacturer has stock of these (originally I think they wanted to supply RCA 6080).
> I am very curious how this amp sounds - please let us know your initial impressions!


Right off the bat I am very impressed. Nice, full sound with bass, the mids are present and the treble is very mellow. I hate to say anything firm as this is day one, but I think this was a good choice.


----------



## mordy

Shane D said:


> Right off the bat I am very impressed. Nice, full sound with bass, the mids are present and the treble is very mellow. I hate to say anything firm as this is day one, but I think this was a good choice.


Thanks, keep us posted. Russian driver tube?


----------



## Shane D

It is the stock tube, a 6H9C. A member on here was kind enough to send me an extra 6SL7 that he has. I am thinking about trying a few different 6SL7's.

That is how messed up this hobby has made me. I am perfectly happy with the initial sound, but I can't stop thinking about other tubes that I have never heard before.


----------



## jonathan c

Shane D said:


> It is the stock tube, a 6H9C. A member on here was kind enough to send me an extra 6SL7 that he has. I am thinking about trying a few different 6SL7's.
> 
> That is how messed up this hobby has made me. I am perfectly happy with the initial sound, but I can't stop thinking about other tubes that I have never heard before.


…the glass is always tubier on the other side 🤪


----------



## GPJ7

Shane D said:


> Right off the bat I am very impressed. Nice, full sound with bass, the mids are present and the treble is very mellow. I hate to say anything firm as this is day one, but I think this was a good choice.


Looks like a cool amp. I've had 4 different Little Dot amps and they were all great. I have none currently.

There were a bunch of people with failed Thompson 6080's (self included). I hope you got a legit good pair.

Mine worked very briefly and then quit instantly with no warning in a Bottlehead Crack. I also had them in a Woo Audio 2 and thought they sounded very good. But now I am gun shy to ever try them again.


----------



## JazzVinyl

mordy said:


> Thanks, keep us posted. Russian driver tube?


Chinese made 6H9C (6SL7 equiv).


----------



## JazzVinyl

GPJ7 said:


> Looks like a cool amp. I've had 4 different Little Dot amps and they were all great. I have none currently.
> 
> There were a bunch of people with failed Thompson 6080's (self included). I hope you got a legit good pair.
> 
> Mine worked very briefly and then quit instantly with no warning in a Bottlehead Crack. I also had them in a Woo Audio 2 and thought they sounded very good. But now I am gun shy to ever try them again.



I heard about a bunch of Thomson 6080's that were purchased from folks in Eastern Europe that were bad, or went bad quickly as you describe.  
There appears to be a bunch in Taiwan (imported long ago) and I wonder if some of these were obtained by Little Dot?

See:
https://www.ebay.com/itm/174881300951

One of the photos there, shows a big pallet full of them...

Did you obtain yours from Taiwan?  Or an Eastern Europe seller?  Just curious.


----------



## JazzVinyl (Apr 12, 2022)

Shane says the MK9 runs quite warm. 

@mordy is an expirenced tube man, who kept his Elise out of "too warm" danger by employing a fan from day one.  Several of us bought the initial Elise, everyone suffered heat damage, except Mordy, who was savvy enough to employ that fan to blow away excessive heat before it could linger under the hood of his Elise and cause damage.


----------



## Shane D

GPJ7 said:


> Looks like a cool amp. I've had 4 different Little Dot amps and they were all great. I have none currently.
> 
> There were a bunch of people with failed Thompson 6080's (self included). I hope you got a legit good pair.
> 
> Mine worked very briefly and then quit instantly with no warning in a Bottlehead Crack. I also had them in a Woo Audio 2 and thought they sounded very good. But now I am gun shy to ever try them again.


I was thinking about getting a back up set of 6080's, but these seem really nice. Now you're making me think.


----------



## GPJ7

JazzVinyl said:


> I heard about a bunch of Thomson 6080's that were purchased from folks in Eastern Europe that were bad, or went bad quickly as you describe.
> There appears to be a bunch in Taiwan (imported long ago) and I wonder if some of these were obtained by Little Dot?
> 
> See:
> ...



Mine were from a store called The Tube Maze.

https://www.ebay.com/sch/i.html?_dm...tubemazestore&store_name=tubemazestore&_oac=1

They must have got burned when receiving them but they wouldn't refund me and I don't support them anymore.

Hopefully the people who received sets of good ones get many enjoyable hours from them. It is a good sounding tube otherwise.


----------



## GPJ7

Shane D said:


> I was thinking about getting a back up set of 6080's, but these seem really nice. Now you're making me think.



It could be possible it was just a bad batch that got out .....  would be a great thing if it could be confirmed they are no longer out in the wild. 

I hate to be negative but don't want people to be burned like I was. Thankfully they were not expensive when I bought them.


----------



## Shane D

GPJ7 said:


> It could be possible it was just a bad batch that got out .....  would be a great thing if it could be confirmed they are no longer out in the wild.
> 
> I hate to be negative but don't want people to be burned like I was. Thankfully they were not expensive when I bought them.


I appreciate the info, regardless.

It only makes sense to have a back up set, so I will get on that soon.


----------



## JazzVinyl

Shane D said:


> Right off the bat I am very impressed. Nice, full sound with bass, the mids are present and the treble is very mellow. I hate to say anything firm as this is day one, but I think this was a good choice.



Sounds like good synergy with your Grado's.


----------



## Shane D

JazzVinyl said:


> Sounds like good synergy with your Grado's.


Yes it is. I will use the Grado's for another day or two and then start trying something different.


----------



## mordy

I would suggest inexpensive Sylvania 6080 tubes; they sound very good. And if they are too inexpensive, you can always look for Mullard branded Sylvania 6080 and pay 10 times more lol.
https://www.ebay.com/itm/265486320330?hash=item3dd037c2ca:g:zq4AAOSwnz9h1jKK


----------



## Shane D

mordy said:


> I would suggest inexpensive Sylvania 6080 tubes; they sound very good. And if they are too inexpensive, you can always look for Mullard branded Sylvania 6080 and pay 10 times more lol.
> https://www.ebay.com/itm/265486320330?hash=item3dd037c2ca:g:zq4AAOSwnz9h1jKK


A lady got back to me with this: We also have the JAN 6080WC tubes by motorola , RCA or others @ US$25.00/C$31.25 each.


----------



## triod750

Or you could look for Telefunken branded General Electric...https://www.ebay.co.uk/itm/264912109312?hash=item3dadfdff00:g:KZcAAOSwunJflVJc
Look at the GE dots in the third photo. At least he is showing them. I don't think everyone does.


----------



## mordy

triod750 said:


> Or you could look for Telefunken branded General Electric...https://www.ebay.co.uk/itm/264912109312?hash=item3dadfdff00:g:KZcAAOSwunJflVJc
> Look at the GE dots in the third photo. At least he is showing them. I don't think everyone does.


Try Eskimofridge in Canada and ask what he has in stock:
https://www.ebay.com/itm/373788809062?hash=item57078c9766:g:pxwAAOSwYZdhjeNj


----------



## JazzVinyl

Parts Express still has new GE 6AS7GA's for cheap:

https://www.parts-express.com/6AS7GA-6AS7-GE-JAN-Vacuum-Tube-072-612

.


----------



## GPJ7 (Apr 13, 2022)

JazzVinyl said:


> Parts Express still has new GE 6AS7GA's for cheap:
> 
> https://www.parts-express.com/6AS7GA-6AS7-GE-JAN-Vacuum-Tube-072-612
> 
> .



I have a bunch of 6080 and 6AS7G's and decided to try those tubes you linked a while back. They are light weight and feel cheap but I have to tell you they sound as good as any tube of that family I've used. I recommend them.

I have also bought tubes from mercedesman on ebay and he it a great seller. Most, if not everything he sells is NOS or above. I think these look really good and they are super affordable. Take a look at the info in his description.

https://www.ebay.com/itm/325114893615?hash=item4bb25b952f:g:zMEAAOSwNy9iOzRK


----------



## Freia (Apr 14, 2022)

Update about noise floor with C3gs.
My C3g were noisier compared to my other tubes. Eventually I found out the static only comes out from one side. If I would to guess it may be the adapters at fault, will be ordering a new pair to see if it fixes the problem.

My plan was to switch the left and right tubes with their adapters to see if the noise will change. Then change the adapters to determine if one of the adapter really is the root of my problems. However, turns out the noise still remains in the left channel after my first swap. Was not expecting this. This may very mean it is my amp that was causing the hum. In quick intervals while the amp still warm, I popped in a pair of Voskhods in. Interestingly when I powered on the amp the noise floor was full on, then quickly dissipated leaving me with a dark background that I initially experienced. 

Are there any LD I+ users that roll C3g? Now I'm not sure if my amp is bad or C3g was just not meant for it in the first place.


----------



## gibosi

Freia said:


> Update about noise floor with C3gs.
> My C3g were noisier compared to my other tubes. Eventually I found out the static only comes out from one side. If I would to guess it may be the adapters at fault, will be ordering a new pair to see if it fixes the problem.
> 
> My plan was to switch the left and right tubes with their adapters to see if the noise will change. Then change the adapters to determine if one of the adapter really is the root of my problems. However, turns out the noise still remains in the left channel after my first swap. Was not expecting this. This may very mean it is my amp that was causing the hum. In quick intervals while the amp still warm, I popped in a pair of Voskhods in. Interestingly when I powered on the amp the noise floor was full on, then quickly dissipated leaving me with a dark background that I initially experienced.
> ...



For sure, the LD was not designed to run C3g. But years ago, I used the C3g in my LD1+ and don't remember them being noisy.


----------



## Freia

gibosi said:


> For sure, the LD was not designed to run C3g. But years ago, I used the C3g in my LD1+ and don't remember them being noisy.


Kind of odd with how only one channel is noisy though; this means one of the channels is not working as intended. But technically since it’s flawless with original tubes, I can’t really say it is broken. Shame tho, I really enjoyed the spacious soundstage of the c3gs.


----------



## mordy

Freia said:


> Kind of odd with how only one channel is noisy though; this means one of the channels is not working as intended. But technically since it’s flawless with original tubes, I can’t really say it is broken. Shame tho, I really enjoyed the spacious soundstage of the c3gs.


I don't have experience with the LD 1+ but I had a similar problem with one channel being noisy in the LD MKIII. It may be worthwhile to see if you can identify an external source for the hum such as a portable phone, router, flourescent light etc. Moving the amp further away from souch a source may be helpful.


----------



## Estratica

O

One help please. I bought a Little Dot MKII that came with 4 otk7 6k1n eb tubes, plus 4 otk1 6k1n eb tubes and 4 6h6n ix power tubes. Does anyone know which family these tubes belong to? EF95(6j1) or EF92? Thanks.


----------



## mordy

Estratica said:


> O
> 
> One help please. I bought a Little Dot MKII that came with 4 otk7 6k1n eb tubes, plus 4 otk1 6k1n eb tubes and 4 6h6n ix power tubes. Does anyone know which family these





Estratica said:


> tubes belong to? EF95(6j1) or EF92? Thanks.


OTK is a Russian term for “inspected by” inspector #7 or #1 as of above - it has nothing to do with the tube designation. It has to be surmised that the quality control was stricter in the earlier years of communism (1950-1970s).
EB is a suffix denoting longer life. 
EB = 5000 hours
DR = 10,000 hours
Regular tubes are supposed to last 3000 hours.
IMHO opinion the longevity of the tube bears no relation to the sound.
It could also be that the hour ratings are made under harsh conditions in a tank or fighter jet - the tubes usually last very long.
The 6H6N tubes have a date code on them - IX is September and there should be a year there as well. If my memory serves me right a two digit year code like 86 for 1986.
The 6J1 tubes belong to the EF95 family.


----------



## Estratica

mordy said:


> OTK is a Russian term for “inspected by” inspector #7 or #1 as of above - it has nothing to do with the tube designation. It has to be surmised that the quality control was stricter in the earlier years of communism (1950-1970s).
> EB is a suffix denoting longer life.
> EB = 5000 hours
> DR = 10,000 hours
> ...


Thanks for the quick response.
Power tubes 6H6"N" (resembles an N) installed and spares indicate IX/77 and XI/75, none are dated.
Excuse my ignorance, wasn't it clear 6H6N are equivalent to 6J1 that belong to the EF95 family?
As I understand the LD MKII jumpers are specific to the power tubes.
Is the deduction correct?
The pre tubes have some numbers that I don't understand, I'll attach photos.
Thank you for your help.


----------



## TrollDragon

Estratica said:


> Thanks for the quick response.
> Power tubes 6H6"N" (resembles an N) installed and spares indicate IX/77 and XI/75, none are dated.
> Excuse my ignorance, wasn't it clear 6H6N are equivalent to 6J1 that belong to the EF95 family?
> As I understand the LD MKII jumpers are specific to the power tubes.
> ...


The 6H6N tubes are output tubes, the 6J1 are driver tubes, they are not the same.  The jumpers and switches are for the driver tubes only.

Do you not have a manual for the amp?
http://www.popular-hifi.com/projects/nad_stereo/little_dot/little_dot_mk2_manual.pdf


----------



## triod750

6H6N (as it looks like) is kyrillic lettering. We call it 6N6P and this is a respected output tube, available in different versions from different Soviet factories. To some they sound different, to others not, and as TrollDragon writes they are the output/power tubes.
_
"spares indicate IX/77 and XI/75, none are dated"_.
They are actually dated. IX means September and XI November. September 1977 and November 1975.


----------



## mordy (Apr 21, 2022)

triod750 said:


> 6H6N (as it looks like) is kyrillic lettering. We call it 6N6P and this is a respected output tube, available in different versions from different Soviet factories. To some they sound different, to others not, and as TrollDragon writes they are the output/power tubes.
> 
> _"spares indicate IX/77 and XI/75, none are dated"_.
> They are actually dated. IX means September and XI November. September 1977 and November 1975.


And the rhomboid figure in the middle of the date code is the logo of the Nevz factory in Novosibirsk. Originally Russian vacuum tubes were manufactured in Petersburg and Moscow, but during WWII production was moved very far away to places like Siberia and Kazakhstan.
To recap, driver tubes are very different from power tubes. The 6J1 is a driver tube that needs the settings from the EF95 family.


----------



## Shane D

Being repetitive but, here are some tubes I got today for my LD MK9:
Matched set of RCA 6080's from a vendor in Vancouver along with a 6SL7WGT.

I also got a 6SL7 from JazzVinyl down in New Mexico.
Pic's attached.
Early comments: The "new" 6080''s are a few decibels quieter. The tube from down south is not as thick and bassy/gooey. Gives the amp a thinner sound. Hmmmm.


----------



## JazzVinyl

The RCA driver sounding thinner than the supplied Chinese 6SL7 is certainly a surprise….


----------



## Shane D (Apr 21, 2022)

JazzVinyl said:


> The RCA driver sounding thinner than the supplied Chinese 6SL7 is certainly a surprise….


Nice change though. And I am not sure thinner is the right word. Lighter? More mid or treble focused?
Very different from the stock tube.


----------



## triod750

Would 'cleaner' suit?


----------



## Shane D

triod750 said:


> Would 'cleaner' suit?


Maybe. Today the system is wildly different, but that is part tube and part headphone.
Starting tomorrow, i am going to start rolling all the driver tubes with each headphone.

I need a spreadsheet!


----------



## triod750

Or you might need a rest ...


----------



## Shane D

triod750 said:


> Or you might need a rest ...


Nah, I love it.


----------



## JazzVinyl

More mid-centric would be a typical RCA house sound attribute.   More detail in the mids and treble is possible as well 
Spreadsheet of impressions is a good idea.


----------



## Estratica (Apr 21, 2022)

Thank you TrollDragon and

triod750 for the help.

Ok, the jumpers must be configured according to the family of the tubes of the drive.
So my LD 2 is fine for the tubes I'm using.

I bought the LD 2 with the aim of making the DIY Class A/B amplifier sound with a wider and deeper soundstage.

The results on the Philips SHP9500 headphones were lovely, three-dimensional (I changed the gain switches to 1 off/2 on), but on the speakers (Monitor Audio Bronze 2) almost nothing changed on stage.

I was in doubt if the LD 2 being used as a preamp the headphone should stay on, so I decided to use a low cost headphone while using the preamp.

Something interesting happened when I turned off the headphones while the music was playing through the speakers: the volume increased a little, but the soundstage was wide and very deep!

The question is, can I use the LD 2 as a preamp without headphones connected?

Thank you for your help.

hugs


----------



## Estratica (Apr 21, 2022)

This is my first forum contribution, the goal is to quickly solve the LD 2 strong blue LED problem.
I just bought an LD 2 and the high-brightness blue LED is very annoying, especially if the LD 2 is close to eye level.
How to solve without disassembling the entire LD 2, using a soldering iron to remove the original led and install another one with lower brightness?
The procedure is simple and uses only two tools: a phillips screwdriver to remove the 4 screws from the front panel - keep them in a closed box because they fall to the floor and disappear - and a 10mm wrench to remove the screw that secures the volume control on the panel.
The sequence: pull the volume knob, remove the 4 screws and the volume control screw and washer, remove the front panel, take the nail polish, shake to mix the pigments well and paint the led, avoid excess on the nail polish brush until it is homogeneous, without flaws in the painting.
Wait 10 minutes, repaint, wait 15 minutes, mount the panel in reverse order and enjoy a discreetly bright LED.


----------



## JazzVinyl (Apr 21, 2022)

In the past, I have used flat black fingernail polish.  Cover the LED, let it dry completely use an exacto knife to uncover a tiny portion of the LED.

Very nice first post, @Estratica !!


----------



## TrollDragon

Estratica said:


> The question is, can I use the LD 2 as a preamp without headphones connected?


Nice job on the LED change, I converted my MK IV over to an amber LED within the first week. 

The headphone jack on the MK2/3/4 series LD is directly in parallel with the RCA pre out jacks. There is no circuitry difference between the two outputs, you can most definitely use the pre outs to your speaker amplifier without headphones attached.

The only problem is that Little Dot highly suggests that you do NOT connect the pre outs to a Direct Coupled amplifier. If you end up getting an extremely rare output tube short, the LD can send high voltage DC out the RCA ports into your amp and that could take out your whole audio chain all the way to the speakers. It would also take out any headphone you have plugged in for that matter.  I think during the whole history of this thread there has only been one user with that experience but I don't remember the details as it was quite a few years back.

This is just something for you to be aware of if your amp is Direct Coupled (check product literature or contact the dealer/manufacturer).


----------



## Estratica

TrollDragon thanks for answering my question!

I have a DIY Class A/B amplifier with a DC protection board, I don't understand electronics, but it looks like my speakers are protected, am I right?

Thanks.


----------



## Shane D

New tube today. May be my favourite. It is a JAN CHS 6SL7WGT by Sylvania. Really clean sound. The "noisiest" song in my test list is Around the World by Red Hot Chili Peppers. This tube slides smoothly though it.
Not as bass focused as the stock tube and a little cleaner than the re-branded RCA.
BF2 to MK9 to LSA HP-2's is very nice. My third tube and the winner with these 'phones.
Now I want to run back to the Grado's and Elex's and try them with this tube.

Not a bass monster now, but a great sounding amp.


----------



## TrollDragon

Estratica said:


> TrollDragon thanks for answering my question!
> 
> I have a DIY Class A/B amplifier with a DC protection board, I don't understand electronics, but it looks like my speakers are protected, am I right?
> 
> Thanks.


Yes the DC protection board should keep your speakers safe.


----------



## Estratica (Apr 22, 2022)

TrollDragon said:


> Sim, a placa de proteção DC deve manter seus alto-falantes seguros.



Thanks, the instructions helped a lot. Hugs.


----------



## JazzVinyl

Shane D said:


> New tube today. May be my favourite. It is a JAN CHS 6SL7WGT by Sylvania. Really clean sound. The "noisiest" song in my test list is Around the World by Red Hot Chili Peppers. This tube slides smoothly though it.
> Not as bass focused as the stock tube and a little cleaner than the re-branded RCA.
> BF2 to MK9 to LSA HP-2's is very nice. My third tube and the winner with these 'phones.
> Now I want to run back to the Grado's and Elex's and try them with this tube.
> ...



i knew if you liked Grado cans, that you would dig the Sylvania tube “house sound”.


----------



## jonathan c

Interesting that your favourite (?) is the Sylvania 6SL7WGT. In the Woo WA6SE, my favourite driver tube (pair) is the Sylvania 13DE7….very clear, detailed, extended…


----------



## JazzVinyl

jonathan c said:


> Interesting that your favourite (?) is the Sylvania 6SL7WGT. In the Woo WA6SE, my favourite driver tube (pair) is the Sylvania 13DE7….very clear, detailed, extended…



Yep, just about the opposite of the RCA house sound...which tends to be lazier, laid back and a bit darker


----------



## Shane D (Apr 22, 2022)

JazzVinyl said:


> i knew if you liked Grado cans, that you would dig the Sylvania tube “house sound”.


Now it is a tube amp without being thick and bassy. Going with this for a few days and then back to the Grado's and Elex's.
Nice to know that this amp will be more than a one dimensional bass monster, with tube rolling. Every week I like this amp more.

I am sure these headphones (LSA HP-2's) make a big difference too.

I am now thinking I should go back to the Grado's in the morning.


----------



## Shane D

Today I put my Elex's back on to try out that clean new tube. A funny thing happened after one run through the test list...I went back to the stock tube.
It turns out that thick and bassy was why I bought this amp and why I like it.


----------



## triod750

I hear you. But remember that a new tube might need plenty of time to perform at its best and that the change can go either way.


----------



## mordy

Estratica said:


> This is my first forum contribution, the goal is to quickly solve the LD 2 strong blue LED problem.
> I just bought an LD 2 and the high-brightness blue LED is very annoying, especially if the LD 2 is close to eye level.
> How to solve without disassembling the entire LD 2, using a soldering iron to remove the original led and install another one with lower brightness?
> The procedure is simple and uses only two tools: a phillips screwdriver to remove the 4 screws from the front panel - keep them in a closed box because they fall to the floor and disappear - and a 10mm wrench to remove the screw that secures the volume control on the panel.
> ...


I am not handy enough to open up the amp and solder etc etc. I have solved bright LEDs by putting a little piece of colored tape over it. Not elegant, but it works.


----------



## mordy

TrollDragon said:


> Nice job on the LED change, I converted my MK IV over to an amber LED within the first week.
> 
> The headphone jack on the MK2/3/4 series LD is directly in parallel with the RCA pre out jacks. There is no circuitry difference between the two outputs, you can most definitely use the pre outs to your speaker amplifier without headphones attached.
> 
> ...


I had a Little Dot MKIII and didn't see that it said in the manual not to use it plugged in into an equalizer circuit. As you mention, a very large spike of high voltage could occur. It did, and fried the circuit board in my ss 100W amp. It actually happened twice - until I finally understood what was happening. Nothing happend to the tube amp though.


----------



## triod750

mordy said:


> I had a Little Dot MKIII and didn't see that it said in the manual not to use it plugged in into an equalizer circuit. As you mention, a very large spike of high voltage could occur. It did, and fried the circuit board in my ss 100W amp. It actually happened twice - until I finally understood what was happening. Nothing happend to the tube amp though.


Tube amps rule! They are real solid state killers!!


----------



## lapmic

lupoal said:


> @stuntmanx8
> 6N6P… well probably I have 8 -10pcs of them, 3 - 4 different manufactures and production date... they are all just nice, nothing really special (imho)… they drain a lot of current and transfer heat to the amp body
> 
> if you really want to have an upgrade buy/build an adapter 6N6P to 6SN7… then do not search for white unicorn, just a good Russian NOS tube is fine and cost few bucks… or GE… or Sylvania… Tungsol are, imho, too light and doesn’t match well with Voshkod… RCA are also nice, a little slow and fat… the modern Chinese are good too, probably not the same quality as the nos from Russia and not the same expected life time, but modern sound fast and with punch, and cheap
> ...


I know it's been a while since your comment, but can I ask what 6SN7s are you using (with adapter to 6n6)?
Thanks!


----------



## TrollDragon

mordy said:


> I had a Little Dot MKIII and didn't see that it said in the manual not to use it plugged in into an equalizer circuit. As you mention, a very large spike of high voltage could occur. It did, and fried the circuit board in my ss 100W amp. It actually happened twice - until I finally understood what was happening. Nothing happend to the tube amp though.


Nothing specific about an equalizer but it definitely mentions Direct Coupled amplifiers.

Little Dot MK III Pre-Amplifier Use​The Little Dot MK III is not to be used with a DC or direct coupled power amplifier. Doing so may
result in damage to your Little Dot and/or downstream components!

Little Dot MK IV / SE Pre-Amplifier Use​The Little Dot MK IV / SE is not to be used with a DC or direct coupled power amplifier. Doing somay result in damage to your Little Dot and/or downstream components! The Little Dot MK IV / SE should only be used with AC / capacitor coupled power amplifiers. If you are unsure if your power amplifier or receiver is AC or DC coupled, please contact the manufacturer’s support line.


----------



## mordy

TrollDragon said:


> Nothing specific about an equalizer but it definitely mentions Direct Coupled amplifiers.
> 
> Little Dot MK III Pre-Amplifier Use​The Little Dot MK III is not to be used with a DC or direct coupled power amplifier. Doing so may
> result in damage to your Little Dot and/or downstream components!
> ...


Thanks - I did not make myself clear in my post. What I meant was that I unfortunately plugged in the Little Dot MKIII  into the jacks of the equalizer circuit on the back of my direct coupled receiver.
*POOF!*


----------



## triod750

But it was an exquisite *POOF!*, wasn't it?


----------



## mordy

triod750 said:


> But it was an exquisite *POOF!*, wasn't it?


Naw, just a dead channel and despair...


----------



## triod750

mordy said:


> Naw, just a dead channel and despair...


----------



## JazzVinyl

mordy said:


> Thanks - I did not make myself clear in my post. What I meant was that I unfortunately plugged in the Little Dot MKIII  into the jacks of the equalizer circuit on the back of my direct coupled receiver.
> *POOF!*



Did it happen upon turning the LD on?


----------



## mordy

JazzVinyl said:


> Did it happen upon turning the LD on?


As I recall I used my setup with the LD MKIII connected to my receiver via the eq jacks for a while, but one day the circuit board blew up on one channel. It could have been on start-up - but I don't remember clearly. Seems that a large voltage spike of 155V could occur.


----------



## JazzVinyl (May 10, 2022)

A $5.00 RCA 12SL7 in the MK9. 

Scary tube! It gives the TS BGRP a run for it’s money!!

Deep Bass, not as dark as the TS but not “too bright” either.


----------



## Estratica

I have a doubt.
The tube in the photo looks like the 6J1P EB am I right?
I have two spare units and I was thinking of trying it on the Fx Audio Tube 03 that has the GE JAN 5654W tube.
Can I make the exchange without damage to the device or the 6J1P tubes?
Thanks.


----------



## mordy (May 12, 2022)

The 6J1P and the 5654W are interchangeable. Cannot tell from the picture if it is a 6J1P but if it says 6Ж1П then it is.


----------



## warp2600

Estratica said:


> The tube in the photo looks like the 6J1P EB am I right?





mordy said:


> Cannot tell from the picture if it is a 6J1P but if it says 6Ж1П then it is.


Yes, the tube in the photo has the cyrillic "6Ж1П" and below that the  "EB" lettering.


----------



## Estratica

mordy said:


> The 6J1P and the 5654W are interchangeable. Cannot tell from the picture if it is a 6J1P but if it says 6Ж1П then it is.


W

Thanks for the quick guidance. Hugs.


----------



## Estratica

mordy said:


> The 6J1P and the 5654W are interchangeable. Cannot tell from the picture if it is a 6J1P but if it says 6Ж1П then it is.


Thanks Mordy.


----------



## mordy

Estratica said:


> Thanks Mordy.


There is a source called Radiomuseum. All you do is type in Radiomuseum5654 or whatever tube you want to know about. Then a window opens up  with other designations of the same tube, or similar tubes.
https://www.radiomuseum.org/tubes/tube_56545.html
Sometimes you need to search under different designations to get the answer:
https://www.radiomuseum.org/tubes/tube_6j1p.html
6J1P and 5654W don't appear on the same page, but they are both in the EF95 family and then you know that they are compatible.


----------



## Estratica

mordy thanks for the guidance.
Hugs.


----------



## mordy

Estratica said:


> mordy thanks for the guidance.
> Hugs.


Thanks


----------



## RaynFox

So after a while, I've been reading a lot about tube rolling and I finally got to tube roll my Little Dot Mk3. I must say, simply amazing. I'm currently using JJ 6SN7 in adapters + socket savers (didn't want to remove the golden rings) and Voskhod Rocket 6ZH1P-EV for the driver tubes. It's a great combo, I can actually hear a lot of new things in msuic that I couldn't before - I'm surprised by this. What I noticed the most going from the stock tubes tho is more bass. It's smoother and nicer sounding but there is more of it. It's a very audible difference with Sennheiser HD 6XX that I'm using. Overall tho, very nice sound and I can recommend this combo! Of course also attaching pictures. Wouldn't win a beauty contest but it's worth it. They look absolutely stunning in total darkness.


----------



## lupoal

Freia said:


> Now I'm not sure if my amp is bad or C3g was just not meant for it in the first place.



check the voltage at the heater pins under load… I discovered in my MKII it was way too low to drive C3g within tube specs


----------



## rev92

Does anyone know what happened with the brand? Their Facebook is dead, the website is down, no responses to e-mails for like a year now.


----------



## Shane D

I dealt with Shenzhen when I bought my amp recently and everything went pretty smoothly.


----------



## GotNoRice

rev92 said:


> Does anyone know what happened with the brand? Their Facebook is dead, the website is down, no responses to e-mails for like a year now.



I got my first Little-Dot amp back in 2006 and in all that time they've gone through quite a few different websites.  I wouldn't read too much into it as long as they remain in-stock at other places.  Here is one of their older sites that mostly still works: https://www.littledot.net/


----------



## jonathan c

Little Dot gear is also available through Shenzhen Audio.


----------



## Shane D

jonathan c said:


> Little Dot gear is also available through Shenzhen Audio.


You have Got to stop copying me!


----------



## jonathan c

Oops, I just saw your post….🤦🏻🐼**

(** panda = self-inflicted 2 black eyes…😖)


----------



## Shane D

jonathan c said:


> Oops, I just saw your post….🤦🏻🐼**
> 
> (** panda = self-inflicted 2 black eyes…😖)


If you are wracked by guilt, feel free to fire off one of your excess Woo amps WAY up north...


----------



## jonathan c

There are no excess Woos. There are no excess headphones, either. 🤣🤣🤣


----------



## triod750

There is just excess excess.


----------



## jonathan c

As stated by Oscar Wilde, “nothing succeeds like excess”. 🤪😜🤣.


----------



## majo123

Unashamed plug. . I have a little dot mkii for sale in the ads of anyone is interested.
Cheers.!


----------



## GotNoRice

Anyone else really love "Ultron" EF92 tubes? Ever since I got my Little-Dot II+ (MKII predecessor) back in 2006 I've tried lots of EF92 tubes and these have been my favorite.  A few years ago one tube started to get noisy (background static/hiss) so I had to retire them.  Finally found another pair on eBay this last week.  They definitely have the sound that I remember.  I love them in my Little-Dot II+.  I like them a lot in my Little-Dot I+ also but with that amp, the 408A tubes tend to have a bit more gain so not really a fair comparison; I generally gravitate to the 408A, where a pair of Sylvania 408A tubes are my favorite.


----------



## gibosi

GotNoRice said:


> Anyone else really love "Ultron" EF92 tubes? Ever since I got my Little-Dot II+ (MKII predecessor) back in 2006 I've tried lots of EF92 tubes and these have been my favorite.  A few years ago one tube started to get noisy (background static/hiss) so I had to retire them.  Finally found another pair on eBay this last week.  They definitely have the sound that I remember.  I love them in my Little-Dot II+.  I like them a lot in my Little-Dot I+ also but with that amp, the 408A tubes tend to have a bit more gain so not really a fair comparison; I generally gravitate to the 408A, where a pair of Sylvania 408A tubes are my favorite.



Ultron didn't manufacture tubes. They simply bought them from various manufacturers, relabeled them and sold them under their own name. So it may or may not be true that all "Ultron" EF92 tubes were sourced from the same maker. It sounds like you got lucky, but it would be a good idea to compare the internal construction to be sure.


----------



## Estratica

I ask friends for advice.
I bought a Little Dot MKII with the 6ZH1P-EV and 6N23P Voskhod tubes that worked without distortion with the Philips SHP9500 headphones.
I sold the SHP9500 and bought the HiFiMan HE400SE which has distortions when I turn up the volume.
I tried it with the GE Jan 5654W and the distortion subsided, but it didn't go away.
Little Dot MKII did not come with the original valve kit.
It is set to EF95 (6J1).
I have tried every possible gain adjustment and the distortions at high volume continue.
Does anyone have any ideas on how to get rid of the distortions?
HiFiMan HE400SE works perfectly with Topping L30.
I appreciate the help.


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## triod750

I don't know anything about your headphones but 6N23P are not suitable in that service. The amp is designed to use 6N6P type tubes that are much more powerful. I did try, out of curiosity, 6N23P in my LD MKIVSE and there wasn't much output from them into my Sennheiser HD650. The sound was 'sweet' but far from powerful enough. You could use other output tubes too, mostly with adapters, but 6N6P is the most common type. Different 5687 versions could be an alternative if you find them (I like them better) but you would need adapters for them. They are very powerful with good sound quality.


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## triod750

https://www.ebay.co.uk/itm/193442943917 This is the adapter I use in my Little Dot for 5687 power tubes.

Here is another that I have no experience of: https://www.ebay.com/itm/125380559991

But the last few years I have bought all my adapters from @Deyan, a member on this forum. He is reliable and makes adapters with good quality.


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## TrollDragon

Estratica said:


> I ask friends for advice.
> I bought a Little Dot MKII with the 6ZH1P-EV and 6N23P Voskhod tubes that worked without distortion with the Philips SHP9500 headphones.
> I sold the SHP9500 and bought the HiFiMan HE400SE which has distortions when I turn up the volume.
> I tried it with the GE Jan 5654W and the distortion subsided, but it didn't go away.
> ...


OTL amplifiers like the Little Dot Mk II are not designed to run low impedance planar headphones like the HE400SE. You will find it works the best with headphones over 150 ohms.  Your best bet would be to connect the Line Out of the Mk II to the Line In of the L30 and use the tubes as a preamp.

The Mk II just doesn't have enough current to drive the planars properly, also the output impedance is too high.


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## Estratica

Hello TrollDragon!
I turned on the dac on the LD2 and the pre-out of the LD2 on the L30 and the distortions really disappeared.
The sound changed little, it became enveloping, musical.
Keeping the LD2 feeding the L30 generates small gains that do not justify using the LD2 exclusively as a preamp.
Thanks for the sugestion.

I decided to install this XLR input board in the snare amplifier.
If the sound is not good I will change the cis INA137PA for the AD827AQ.
It's a low-cost bet, the alternative is to buy a new amp with original XLR inputs.

https://pt.aliexpress.com/item/1005003229618282.html


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## GotNoRice

Estratica said:


> I ask friends for advice.
> I bought a Little Dot MKII with the 6ZH1P-EV and 6N23P Voskhod tubes that worked without distortion with the Philips SHP9500 headphones.
> I sold the SHP9500 and bought the HiFiMan HE400SE which has distortions when I turn up the volume.
> I tried it with the GE Jan 5654W and the distortion subsided, but it didn't go away.
> ...



Here is what I see:
Philips SHP9500
-Sensitivity 101 dB
-Impedance 32 Ohms

HIFIMAN HE400SE
-Sensitivity 91 dB
-Impedance 25 Ohms

Little-Dot MKII Power Output:
300 mW (600/300 ohm)
200 mW (120 ohm)
100 mW (32 ohm)

So really, neither of those headphones are ideal for the MKII.  The MKII, being a tube amp with no output transformer (aka OTL), will put out more power into HIGHER impedance headphones, and less power into lower impedance headphones.  This is the opposite of what you see in Solid-State devices, or tube amps that do have an output transformer.  The reason is because low impedance requires a lot of current, while high impedance requires a lot of voltage.  The MKII design can supply a lot of voltage, but not much current.

With the Philips SHP9500, you were already pushing the limit of the amp with only 100mw of power available, but at least they had a pretty high 101dB Sensitivity.  Moving to the HIFIMAN HE400SE, you not only decreased impedance from 32 to 25 Ohms, but those headphones also have significantly less sensitivity at 91dB.

So, simply put, the Little-Dot MKII doesn't have enough power for those headphones.  The distortion that you are hearing is almost certainly a result of clipping (soft-clipping and/or hard-clipping).

Unfortunately you don't have any great options other than to get a headphone with a higher impedance or get a different amp that is able to deliver more power into low-impedance headphones.

Compare the output of the Little-Dot MKII with the output of the Little-Dot I+ for example.  The Little-Dot I+ is a hybrid tube amp that uses transistors in the output stage.

Little-Dot I+ Power Output:
150 mW (600/300 ohm)
300 mW (120 ohm)
800 mW (32 ohm)

You can see that this would give you 8 times as much power output when using your Philips SHP9500, and likely even more than that when using the HIFIMAN HE400SE.  I use my Little-Dot I+ with my 24 Ohm Sony XB700 Headphones and they are a perfect match, with the Little-Dot I+ potentially putting out close to an entire watt (1000mW) at 24 ohms, and it definitely needs that power when playing bass-heavy music.  I also have a Little-Dot II+, which is basically a predecessor to the MKII, also an OTL design, with similar power output to the MKII.  It simply doesn't have enough power for the 24-ohm XB700 headphones, very similar to your situation with the HIFIMAN HE400SE and the MKII.  I keep both amps, using the Little-Dot I+ with my low-impedance headphones, and my Little-Dot II+ with my high-impedance headphones.


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## AnalogEuphoria

*Electro Harmonix **6H30Pi EH Gold work with Littledot mk2?*​


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## triod750

AnalogEuphoria said:


> *Electro Harmonix **6H30Pi EH Gold work with Littledot mk2?*​


In an amp designed for 6N6P you can use EH 6H30Pi (6N30Pi). My Little Dot MKIVSE was delivered with those tubes. However, I prefered to use 6N6P. But it's about synergy with the rest of the chain, music chosen and personal preferences.


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## balvan

I picked up an old used *Little Dot MKVI+*. 

It says it uses:
Driver Tubes: 2x 6H9C
Power Tubes: 4x 6080WC

This is my first tube amp, so I know nothing about tubes or socket adapters and such.

Which tubes should I get for it for a nice warm and some what dark sound signature? I am not looking to spend so much on it, so if you could kindly recommend tubers that are good value for money that would be great.


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## gibosi

The Russian 6H9C is equivalent to the American 6SL7GT. IMO, for warm and dark, RCA 6SL7GT and 6080 would be inexpensive tubes to start with.

Have fun!


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## mordy

gibosi said:


> The Russian 6H9C is equivalent to the American 6SL7GT. IMO, for warm and dark, RCA 6SL7GT and 6080 would be inexpensive tubes to start with.
> 
> Have fun!


Another inexpensive suggestion is Sylvania 6080


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## balvan

gibosi said:


> The Russian 6H9C is equivalent to the American 6SL7GT. IMO, for warm and dark, RCA 6SL7GT and 6080 would be inexpensive tubes to start with.
> 
> Have fun!


thanks for the help - is this what you mean: https://www.ebay.com/itm/304688327524

?


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## gibosi

balvan said:


> thanks for the help - is this what you mean: https://www.ebay.com/itm/304688327524
> 
> ?



Yes, RCA 6SL7GT.


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## balvan

I ended up returning it as it had a buzz, noticble even when playing music.


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## gibosi

balvan said:


> I ended up returning it as it had a buzz, noticble even when playing music.



Typically what I do is thoroughly clean the pins with 220 grit sandpaper. This often works. But sometimes these old tubes need to run for several hours, "cook" if you will, before they finally quiet down.


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## balvan

gibosi said:


> Typically what I do is thoroughly clean the pins with 220 grit sandpaper. This often works. But sometimes these old tubes need to run for several hours, "cook" if you will, before they finally quiet down.


I couldn't get the tubes to come out, I just decided to return it, I was not looking for a restoration project. 
Ended up ordering this instead: http://anodeacoustics.in/index.php/...ube-headphone-amplifier-ecl82-pcl82-hp-amp-1/


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## Deleeh

balvan said:


> I couldn't get the tubes to come out, I just decided to return it, I was not looking for a restoration project.
> Ended up ordering this instead: http://anodeacoustics.in/index.php/...ube-headphone-amplifier-ecl82-pcl82-hp-amp-1/


Looking nicly,what have you paid for it?


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## balvan

Deleeh said:


> Looking nicly,what have you paid for it?


580$


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## Deleeh

year is okay for the price ,can‘t say wrong.Have fun with it.
By the way,you know the price for the HP 3?


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## balvan

Deleeh said:


> year is okay for the price ,can‘t say wrong.Have fun with it.
> By the way,you know the price for the HP 3?


The prices are specified at the bottom of the product pages.


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## Shane D

balvan said:


> I couldn't get the tubes to come out, I just decided to return it, I was not looking for a restoration project.
> Ended up ordering this instead: http://anodeacoustics.in/index.php/...ube-headphone-amplifier-ecl82-pcl82-hp-amp-1/


That looks very cool! What is the time frame for delivery? Love to hear your thoughts on the sound.

I checked out the link but I need to check a currency converter.


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## balvan

Shane D said:


> That looks very cool! What is the time frame for delivery? Love to hear your thoughts on the sound.
> 
> I checked out the link but I need to check a currency converter.


Two weeks, but mine will probably be ready on Monday.


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## svmusa

Any LD H1 owners? Curious if the amp has any background noise on headphones and if any one using it as a preamp? Not many reviews from real owners for me to pull the plug other than one on Headfonia hence my question.


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## RockstarRmgddn

Hi guys, I have a problem.

I've recently upgraded to Hifiman Edition XS cans which are planar 18ohm.

My amp is a Little Dot MK2. Due the way it works I have to keep it on the 300ohm highest gain setting for good sound.

*Is there a chance of damaging the cans or the amp because of this?*

Some impressions on the cans:
I've come from the HD600 paired with Mullard 8161. These sound better with Voshkod 6ZH1P-EV. The difference from Sennheisers to these is immense. Way bigger soundstage, better bass, more detail, way faster cans.
These can run just fine out of the DAC, no sound problems like little bass etc but they don't sound nearly as sweet as on the amp.


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## TrollDragon

RockstarRmgddn said:


> Hi guys, I have a problem.
> 
> I've recently upgraded to Hifiman Edition XS cans which are planar 18ohm.
> 
> ...


Little Dot OTL amps don't have the current output that planar headphones require, you are doing yourself a real disservice by not powering the headphones properly.  OTL amplifiers are designed for high impedance headphones and sound their best with them.

The XS are 18 ohms which is well below the output resistance of Little Dot OTL amps so these headphones won't sound their best no matter what jumpers or switches you change.  The best thing would be to use the MK 2 as a preamp for a solid state amp properly driving the XS.


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## haywireman

mordy said:


> Hi all,
> 
> Sometimes you buy a tube that does not have the manufacturers name on it, but some letters are visible. I just found a little guide that identifies US manufacturers that made tubes for the military - JAN (or Joint Army and Navy tubes). May come in handy:
> 
> ...


----------



## haywireman

This is an old thread, but you say you found a little guide for the JAN tubes.  Is that something that was just put together as a simple reference, or was it published somewhere?  If so, could you provide a title, or where it could be found online?  I am trying to find out what authority made those designations.  The only military authority I know is the MIL-E-1 series of documents, but I could not find it there.  Thanks.


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## triod750

https://www.radiomuseum.org/tubes/tube_jan-.html


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## mordy

triod750 said:


> https://www.radiomuseum.org/tubes/tube_jan-.html


Thanks for the reference and comprehensive list!


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