# 1101 Audio custom crafted headphone amps



## leftside

Here are my impressions of the 1101 Audio "V6" custom headphone amp.

I was looking for a custom OTL amp that would sound at least as good as my Glenn 300B custom headphone amp, but with a vast range of tube rolling possibilities. In April of this year I decided to start contacting custom tube amp builders. Mischa was the only person who I connected with straight away, and from his first emails I could tell this guy understood what I was trying to do (even if he thought I was a little crazy!) and from the outset he provided a detailed design.

The amp arrived last week and I've had a few extensive listening sessions since then. The amp is huge! Here are a couple of pictures showing the amp on it's own and also with other pieces to provide some perspective:


----------



## leftside (Nov 17, 2019)

I've only rolled in a few tubes so far, but initial impressions are the 6J5's are like very, very good 6SN7's with similar qualities. Thunderous base when paired with the TS 5998. Superb depth with a hint of warmth. The C3g make the amp sound more like the Glenn 300B with superb clarity, detail and "airiness". The C3g also give the amp greater power than the 6J5 or 6SN7. It's quite the combo with 4 or 6 TS 5998. The TS 12SN7 BGRP sound about the same as their 6SN7 counterpart - which is a very good thing! But, for much cheaper.

Some say the LCD4 is a slightly dark headphone (not me). That's simple to adjust  by using the C3g tubes. For an extended listening session (more than 2-3 hours), I can see myself starting with a bassier tube(s) early on, and then moving to the C3g later.

A similar bass level, perhaps even more so, is with the early Mullard ECC31/6N7 foil getters in the two 6J5 sockets. First time I've heard these running without adapters. Very nice.


----------



## leftside (Nov 17, 2019)

Here are some technical details about the amp:

- OTL topology
- Up to 6 power tubes (5998/6080/6AS7) or 4 6336.
- Switch for 6AS7G/5998 power tubes on the  front of the power supply chassis
- Selector switch for 6SN7/12SN7/6SL7/12SL7 (same single socket) and C3g (two sockets) and 6J5 (two sockets). ECC31/6N7 can also be used in the 6J5 sockets.
- All driver tubes can be plugged in at the same time. Selector switch indicates which are "active".
- 2 piece amp with power supply and amp as separate pieces and connected by an umbilical cord.
- Vu meters on the amp chassis
- Volt meter to measure/display voltage (obviously) and Millamperes meter to show/display milliamperes DC. This value goes up with more power tubes used - each pair of power tubes takes about 95-105 ma, plus an extra 5-10 ma for the biasing and these values are recorded/displayed on this milliamperes meter.

- Using 6SN7, 12SN7 or 6J5 as driver approx. 4.5 watts into 100 ohm, and 3.05 watts into 200 ohm. (Mischa to confirm)
- With C3G as driver it gives slightly more power output: up to 5-6 watts into 200 ohm. (Mischa to confirm)

- Hammond heater transformers for the power tubes (all indirectly heated tubes run on regulated DC).
- Lundahl LL1651 for the high voltage. Power taken from the LL1651 to supply the low voltage for generating regulated DC
for the driver tubes (6SN7/12SN7/6SL7/12SL7/C3g/6J5).
- LT3081 DC regulators to generate super low noise DC for the driver tubes. Driver tubes are also indirectly heated.
- 21st century Maida style regulator for high voltage regulation. Uses a slow start, so allows the heaters to warm up
before full high voltage is applied to the tubes.

- Solid state rectification for high voltage supply.

- Jupiter 0.22uF copper foil paper & wax coupling capacitors: Sit between the driver tube and the output tubes. One for each channel.
- ClarityCap Output capacitors link the cathodes of the power tubes to the headphone jacks. One for every power tube.

All the tubes are employing constant current sources/sinks (CCS) meaning the current going through the high voltage line does not vary over time.

All of the signal circuitry stays inside the amplifier chassis, and all of the unfiltered power stays within the power supply chassis, with only highly filtered DC being sent from the power supply chassis to the amplifier chassis.

The resistors, caps and other components chosen for the build have all been overspec'd to make sure everything is extremely long lived and stable for many decades (Mischa provides a 10 year warranty with the amps because of this). 2% silver leaded solder used as it is the most robust long term.

Most critical resistors have been chosen as very low noise military rated Vishay/Dale resistors. Military rated resistors are overspec'd for their dissipation and long term stability as they have to remain stable and functioning in critical applications within the field (people's lives quite literally depend on it at times). Reviews for the RN55/RN60 series of resistors online are very good.

Notes on impedance:
The LCD-4 would work well with an OTL amp, and even one 6BL7/6080/5998/6AS7G/6336 per sidewould provide enough power to fully drive them to ear splitting levels (you could hit 120+ db levels from the power from one tube per side).

A typical amplifier using one 6080 per channel gives an output impedance of about 50-60 ohm. Using 3 tubes per side could bring theoutput impedance down to 15 ohms or so.


----------



## leftside (Nov 17, 2019)

A tremendous amount of effort went into this amp. The exterior design and idea for features were mainly mine, but obviously the internals of the amp design were from Mischa. I did insist on a few parts though, such as the Jupiter caps.

I took photos such as these to give Mischa an idea of how I'd like the tubes positioned:





And he'd reply with a sketch like the following:


----------



## leftside

Lot's of design diagrams and various ideas were produced along the way, like this initial design:


----------



## leftside

Early internal build of the power chassis:






Completed:


----------



## leftside

Lazering of front panels:


----------



## leftside

I did well for the first day just using the GE 6AS7GA power tubes, and even with cheaper tubes the amp sounds great. But today, I couldn't resist rolling in 6 TS 5998 with TS 12SN7 BGRP and TS 6SN7 BGRP:



 

And TS 5998 with Mullard ECC31/6N7 and Mullard ECC32:


----------



## leftside

The amp sounds fantastic. It's great to hear fairly significant differences with the C3g vs the 6SN7 and related family of tubes. I still have a LOT of power and driver tubes to roll/try out...

Any downsides? The amp does run a little warm with 6 power tubes! I certainly won't need the radiator turned on in the room during the winter when running the amp with 6 power tubes. 2 power tubes also sound very good though.

Feel free to ask and questions. I'm sure I or Mischa will do our best to reply.


----------



## Sound Trooper

Oh my... this amp looks totally bad-ass! I'm sure it sounds fantastic as well. @leftside congrats!!


----------



## Monsterzero

leftside said:


> Feel free to ask and questions. I'm sure I or Mischa will do our best to reply


 Well,yeah,how much does it cost,and how does it stack up vs. your Glenn?


----------



## L0rdGwyn

Beautiful!  Love all the detailed info, looks to be a killer amp.  Very nice you can keep all of your driver tubes in place.  Do they receive power even though they are not "activated"?

Given the highly filtered power and DC on the heaters, is the noise floor quite low?


----------



## leftside

Monsterzero said:


> Well,yeah,how much does it cost,and how does it stack up vs. your Glenn?


You'll have to ask Mischa regarding cost. I'm not sure he'll ever want to build a complex beast like this again lol. He assures me a simpler amp with 2 or 4 power tubes will sound just as good.

Initial impressions are the amp sounds very similar to the Glenn 300B when using the C3g tubes (which is a good thing). It starts to sound quite different when using the 6SN7 and related family of tubes. With tubes like the TS BGRP (6 or 12 volt), Mullard ECC32 or ECC31 there is thunderous bass, and fantastic depth with a hint of warmth. I still have a whole bunch of power and driver tubes to roll.

The Glenn 300B acts as a great baseline. I run both amps at the same time (with the windows open... even in the winter...), swap tubes in the "V6" and then compare sound signatures by simply moving the headphones from one amp to another. I'll also want extended listening sessions with some of my favorite tubes to give further impressions.


----------



## leftside

L0rdGwyn said:


> Beautiful!  Love all the detailed info, looks to be a killer amp.  Very nice you can keep all of your driver tubes in place.  Do they receive power even though they are not "activated"?
> 
> Given the highly filtered power and DC on the heaters, is the noise floor quite low?


The tubes do not receive power if not activated. No "triplets" 

The noise floor is amazingly low considering how many tubes are in my system. I'll try vinyl tomorrow. Just been using the DAC so far.

I've also used the amp with the high sensitive Focal Stellia - and even with those the amp has a very black background. You can only hear the slightest hiss at ear destroying volume levels. It really shines with harder to drive (like planars) with higher ohm ratings (which is what it was designed for).


----------



## L0rdGwyn

Very much undermining the old adage that planars cannot be effectively run on an OTL, very cool.  Well I am sure Mischa will attract some more interested parties based on what you two have created here, well done, will be very interested to see what other projects head his way. 

You have a lot of tube rolling to do


----------



## whirlwind (Nov 18, 2019)

Fantastic little review with some awesome pics.

Good lord I bet the LCD-4 bass about knock you out of your chair when using 6 Tung Sol 5998 and the ECC31/32

Good stuff!  I love the tube layout.


----------



## rosgr63

Beautiful amp, congratulations!

I hope it gives you lots of listening pleasure.

Thanks for the detailed info and photos, a work of art.

Enjoy, Happy Listening!


----------



## leftside

For those who have asked, you can PM Mischa on here:
https://www.head-fi.org/members/a2029.68207/


----------



## Xcalibur255

Congrats on the new amp!  It certainly looks like the ultimate tube rolling machine.

Does Mischa laser these front panels, or is it sent out to some place like Front Panel Express?  Being able to laser the control labels onto the chassis really takes the professionalism and look to the next level on these custom builds.


----------



## A2029

Xcalibur255 said:


> Congrats on the new amp!  It certainly looks like the ultimate tube rolling machine.
> 
> Does Mischa laser these front panels, or is it sent out to some place like Front Panel Express?  Being able to laser the control labels onto the chassis really takes the professionalism and look to the next level on these custom builds.



I have access to an Epilog Mini Laser Cutter to do the engraving


----------



## A2029

leftside said:


> - Using 6SN7, 12SN7 or 6J5 as driver approx. 4.5 watts into 100 ohm, and 3.05 watts into 200 ohm. (Mischa to confirm)
> - With C3G as driver it gives slightly more power output: up to 5-6 watts into 200 ohm. (Mischa to confirm)



Some more specs on the amp:
*
Power output when running with 6 power tubes:*
6AS7 & C3G Driver:
4.5W into 100 Ohm
5W into 200 Ohm
2.7W into 300 Ohm

6AS7 & 6SN7/12SN7/6J5 Driver:
4.5W into 100 Ohm
3W into 200 Ohm
2.3W into 300 Ohm

5998 & C3G Driver:
4.25W into 100 Ohm
2.7W into 200 Ohm
1.6W into 300 Ohm

5998 & 6SN7/12SN7/6J5 Driver:
4.25W into 100 Ohm
2.7W into 200 Ohm
1.6W into 300 Ohm

*Damping factor:*
6AS7:
>10 into 300 Ohm
>8.5 into 200 Ohm
>4 into 100 Ohm
5998:
>25 into 300 Ohm
>16.5 into 200 Ohm
>8 into 100 Ohm

*-3dB Point:* 2.5 Hz

*Power consumption: *
500W at max loading

*Here are some other features of the amp:*
-Zero feedback, pure class A
-Acoustic Dimensions 41-step attenuator
-Input impedance: 100Kohm
-Balanced and unbalanced headphones can be plugged in simultaneously. Can run up to three headphones at a time (Imagine running 3 HD650/HD800 from the amp at the same time)!
-510uF of oil filled polypropylene capacitance in the high voltage supply
-Over 356000uF of capacitance in 6.3V heater supply!
-ZERO electrolytic capacitors in the signal path (and the signal path includes the high voltage power supply)


----------



## A2029 (Nov 9, 2020)

.


----------



## whirlwind

A2029 said:


> Some more specs on the amp:
> *
> Power output when running with 6 power tubes:*
> 6AS7 & C3G Driver:
> ...




Very cool....thanks for posting.


----------



## leftside

@A2029 does the amp have similar power specs with 2 or 4 power tubes? Is it just the output impedance that changes with more power tubes?

When I first contacted you, I seem to remember you saying 6 power tubes was overkill, but I said I'd still like an amp with 6 power tubes  If I understand correctly, I think an amp with 2 or 4 power tubes will be less complex and therefore cheaper, but should sound very similar to the one with 6 power tubes?


----------



## A2029 (Nov 19, 2019)

leftside said:


> @A2029 does the amp have similar power specs with 2 or 4 power tubes? Is it just the output impedance that changes with more power tubes?



Output impedance goes down the more power tubes per side:
1 tube per side -> ~70 ohm output impedance
2 tubes per side -> ~35 ohm output impedance
3 tubes per side -> ~23 ohm output impedance

Power generally goes down the less power tubes running, here is an example with the 6AS7 and C3G:

6 power tube 6AS7 & C3G Driver:
4.5W into 100 Ohm
5W into 200 Ohm
2.7W into 300 Ohm

4 power tube 6AS7 & C3G Driver:
2.1W into 100 Ohm
4.7W into 200 Ohm
2.7W into 300 Ohm

2 power tube 6AS7 & C3G Driver:
0.5W into 100 Ohm
1.05W into 200 Ohm
2.55W into 300 Ohm




leftside said:


> When I first contacted you, I seem to remember you saying 6 power tubes was overkill, but I said I'd still like an amp with 6 power tubes :) If I understand correctly, I think an amp with 2 or 4 power tubes will be less complex and therefore cheaper, but should sound very similar to the one with 6 power tubes?



An amp with 6 power tubes definitely has more than enough power for the most challenging high impedance loads! 

An amp with 2 or 4 power tubes would be less complex, smaller, cheaper, and overall have similar distortion profiles (i.e. quite similar clarity, bass, tone, and other qualities). There is some slight effect of output impedance on the tone/frequency response of certain high impedance headphones such as the Sennheiser HD650/HD800. Here is a good reference to understand this effect more: https://www.innerfidelity.com/content/musings-headphone-amplifier-output-impedance


The optimal number of tubes for a 200 Ohm headphone such as the LCD-4's is four or six. For 300 Ohm headphones such as Sennheiser HD650/HD800, 4 power tubes (2 power tube per channel) is definitely good and gives a damping factor of >8 which is ideal. 2 power tubes (1 per channel) gives a damping factor of over 4, which is still good enough for most 300 ohm headphones (Senn HD650/800 and ZMF Verite).


----------



## mordy

Hi A2029,
Is there a change in the aggregate multiplifaction factor when using 2, 4 or 6 power tubes? 
If you use pairs of tubes with different mu, is there a way of knowing what the total mu is?


----------



## A2029 (Nov 19, 2019)

mordy said:


> Hi A2029,
> Is there a change in the aggregate multiplifaction factor when using 2, 4 or 6 power tubes?
> If you use pairs of tubes with different mu, is there a way of knowing what the total mu is?



Hi mordy,
Not sure what you mean by aggregate multiplication factor. The output swing from the cathode of power tubes on a cathode coupled OTL amp will always have an amplification factor of less than 1. If using only 6AS7 tubes, more tubes brings the amplification factor slightly closer to 1. E.g. for an input signal of 20V at the power tube grids, One 6AS7 will have an amplification factor of 0.499 into 300 ohms whereas two in parallel will have an amplification factor of 0.555 into 300 ohms.

If you were to try to use a 5998 and 6AS7 tube at the same time on @leftside's amp, then the 5998 would hog most of the current and the overall amplification factor for the power tubes would be higher (i.e. closer to 1 on the power tubes) with the 5998+6AS7 than with two 6AS7.

For two 6AS7 per channel without balancing resistors (4 power tubes total) the 6AS7 with the highest transconductance will hog slightly more of the current and it's amplification factor will dominate. Balancing resistors help to balance the current between tubes when tubes aren't precisely matched (i.e. slightly different mu, transconductance, rp).


----------



## leftside

Picture of the amp section with the Clarity caps showing, I almost decided to keep the caps exposed, but once the tubes have been inserted I think it looks better with the enclosures on:


----------



## leftside

The amp is sounding great. Currently going through the 6N7 tubes at the moment as I've never been able to use those before without adapters. Things that really stand out are bass, depth and separation with a hint of warmth. 

Nice and quiet even with vinyl last night.


----------



## leftside

It's a metal base kinda evening. Super smooth sounding. Textures are amazing. Was running a pair of Fivre 6N7G from 1940 in there the last couple of nights, and they have a bit more punch/impact with slightly more bass, but I think I prefer these 6J5/L63 and B36/12SN7 drivers. The amp already packs a punch in the bass department anyway.

Vocals are gorgeous - especially female vocals.

Will compare to 6J5 coke bottle and B65 at the weekend.


----------



## leftside (Nov 23, 2019)

After a long week of work I decided to remove the LCD-4 and plug in the Stellia. Just went with a pair of power tubes for these. The LCD-4 and amp combo have such a thunderous bass, but I wanted something lighter tonight and therefore the reason to bring out the Stellia.

Well first of all, I've never heard the Stellia have such good bass, but certainly not as thunderous as with the LCD-4. This was perfectly fine for tonight. Even though this amp hasn't been designed for such a high sensitive/low impedance set of headphones, the Stellia still sounds very, very good. The best I've ever heard it. Far better than with the WA22.

Over on the Glenn thread people have asked if there are differences between the GEC B36/12SN7 metal base and pair of GEC L63 metal base. All three of mine are from the early 50's with the inverted saucer getter. I think there is a difference. I found the L63 to be slightly more detailed and clear, with a slightly wider soundstage. Bass is about the same. Will also try with a pair of GEC 6J5 coke bottle from 1949 tomorrow night.


----------



## Ichos

You've got a killer set up!


----------



## leftside

Ichos said:


> You've got a killer set up!


Thanks Ichos. I'm actually visiting Greece next year. Haven't been since I was a young teenager, so really looking forward to the trip as a slightly older man.


----------



## Ichos

Great if you are traveling to Thessaloniki shoot me a pm!


----------



## leftside

Ichos said:


> Great if you are traveling to Thessaloniki shoot me a pm!


That fine city was close to the top of our list, but we ended up deciding upon Athens and a couple of the islands a ferry ride away from Athens. Next time


----------



## mordy

leftside said:


> After a long week of work I decided to remove the LCD-4 and plug in the Stellia. Just went with a pair of power tubes for these. The LCD-4 and amp combo have such a thunderous bass, but I wanted something lighter tonight and therefore the reason to bring out the Stellia.
> 
> Well first of all, I've never heard the Stellia have such good bass, but certainly not as thunderous as with the LCD-4. This was perfectly fine for tonight. Even though this amp hasn't been designed for such a high sensitive/low impedance set of headphones, the Stellia still sounds very, very good. The best I've ever heard it. Far better than with the WA22.
> 
> Over on the Glenn thread people have asked if there are differences between the GEC B36/12SN7 metal base and pair of GEC L63 metal base. All three of mine are from the early 50's with the inverted saucer getter. I think there is a difference. I found the L63 to be slightly more detailed and clear, with a slightly wider soundstage. Bass is about the same. Will also try with a pair of GEC 6J5 coke bottle from 1949 tomorrow night.


It appears to me, that there is a some kind of consensus that having two separate triodes instead of a dual triode of the same kind of tube, yields better sound. From the comments I have been reading it seems to be so across the board. It is not a night and day difference, but still easily recognized by many people.


----------



## leftside

I forgot that two of my power tubes had broken spigots/guides. Obviously inserting two power tubes incorrectly into an amp isn't exactly good for the amp. Luckily, I know my local tech guy quite well from the times I used to go and see him when I had vintage amps and preamps. 

This was totally my fault, but Mischa has been great to work with, and has emailed my local tech guy diagrams and schematics to assist with the repairs. Hoping to be up and running again soon!


----------



## mordy

Hi leftside,
Broken guide pins happen to all of us as well as inserting the tubes the wrong way....I did it a few times with driver tubes but luckily the amp survived.
Here is a post from another thread that I posted - perhaps it will be of help:

These things happen. For me the easiest way is to stick on a little piece of red tape indicating the location of the ridge on the guide pin. If you look carefully at the base, you can almost always see a little notch where that ridge was located.





If you really are worried about the right orientation, you can buy octal rings with a guide pin and attach to the tube.
https://www.ebay.com/itm/6-Pcs-Vacu...115670?hash=item236ccb4316:g:QtIAAOSwacdZbjxB


----------



## leftside

Thanks @mordy. I did indeed mark on the tube base where the pin guide would have been, but totally forgot about it. I now have in big red letters on the tube white cardboard box "Missing pin guide!".


----------



## Zachik

@mordy - are you familiar with rounded ones for "fixing" KT66 with broken key (and rounded bottom)?


----------



## mordy

I am afraid not, but you could contact the people at VIVA tubes  and ask them - they seem to offer good customer service and sell the KT tubes as well.
https://www.vivatubes.com/about-us-contact/
(They have a 25% sale for another day or so)


----------



## mordy

Hi leftside,
Another thought occurred to me: Since you are communicating with the amp designer, perhaps it is possible to incorporate a protective circuit that shuts off the amp if something is shorting out etc? 
I know that this is feasible because the Feliks Audio Euforia has such a circuit and it saved my amp when I used a defective adapter.


----------



## A2029

mordy said:


> Hi leftside,
> Another thought occurred to me: Since you are communicating with the amp designer, perhaps it is possible to incorporate a protective circuit that shuts off the amp if something is shorting out etc?
> I know that this is feasible because the Feliks Audio Euforia has such a circuit and it saved my amp when I used a defective adapter.



Unfortunately a complete shutdown of the amp could not be built into this particular circuit. However, all of the supplies in the amp are regulated, current limited, and reverse voltage protected. If there is a short, the heater supplies have thermal shutdowns. Unfortunately, it was not possible to build a thermal shutdown into the regulated high voltage supply, so a prolonged short will eventually kill the big beefy 9 amp MOSFET in that supply (this happened in leftside's amp).


----------



## mordy

I am sorry to hear about leftside's mishap - since the 9A MOSFET is very inexpensive I am hopeful that it won't be an extensive repair.


----------



## leftside

mordy said:


> I am sorry to hear about leftside's mishap - since the 9A MOSFET is very inexpensive I am hopeful that it won't be an extensive repair.


S*** happens  I'll be extra careful in the future to make sure I don't make the same mistake again.


----------



## leftside (Dec 17, 2019)

I wanted to give it a few weeks until I listened to the Woo WA22 again. I'm running a set of top tier tubes in the WA22: Bendix 6080 slotted plates, ECC32 early foil getters and early Osram U52.

The WA22 simply doesn't compete with the 1101 Audio amp. The sound is good, but lightweight compared to the 1101 Audio amp - even if I run the cheapest tubes in the 1101 amp such as GE 6AS7G and later/more common 6SN7's. The bass and depth is amazing on the 1101 amp.


----------



## UntilThen

You have got a beast of an amp there Leftside. Is it quiet when powered on with no music playing?

Congrats and enjoy !


----------



## leftside

UntilThen said:


> You have got a beast of an amp there Leftside. Is it quiet when powered on with no music playing?
> 
> Congrats and enjoy !


Through the headphones it is very quiet - even with 6 power tubes and 2 driver tubes - with the volume cranked to totally unbearable levels. The power section has a slight buzzing sound if you get close to it.


----------



## UntilThen

leftside said:


> Through the headphones it is very quiet - even with 6 power tubes and 2 driver tubes - with the volume cranked to totally unbearable levels. The power section has a slight buzzing sound if you get close to it.



It is remarkable that with 6 power tubes it is very quiet. This amp must have great control in full song.


----------



## Xcalibur255

leftside said:


> S*** happens  I'll be extra careful in the future to make sure I don't make the same mistake again.



What a bummer that you had to go through the same ordeal I did more or less.    I think there is a greater chance of your amp sounding the same as it did before though.


----------



## rosgr63

leftside said:


> Thanks @mordy. I did indeed mark on the tube base where the pin guide would have been, but totally forgot about it. I now have in big red letters on the tube white cardboard box "Missing pin guide!".



Sorry to hear this.

If the guide pin its missing I put a small red triangular sticker on the base with the arrow pointing to the pin guide position.
This way I always know even if the tube is out of the box.


----------



## Pink Freud

Hi! I'm curious about this amp, how much could a 2 or 4 power tubes version cost?
Thanks


----------



## A2029

Pink Freud said:


> Hi! I'm curious about this amp, how much could a 2 or 4 power tubes version cost?
> Thanks



Hi Pink Freud, costs depend on chosen components to go within the amp. An amp with high end boutique parts such as Jupiter capacitors and Lundahl transformers is more expensive. Please PM me and I can give you a quote after selecting some components


----------



## leftside (Jan 25, 2020)

A couple of you have asked for the complete list of parts in this particular build. This was my "no holds barred" build. With the CCS design, other builds should also sound very good.

Most of this is up-to-date, probably about 95% accurate.

Chassis Material:
Chassis 2 Pesante 2U 400mm (with 10mm front plate) - Black
Aluminum Transformer Covers (Black 134x134x130)  JJTC165
Vented Bottom Cover
Anti-Vibration feet

Front Panel Parts: 
VU Meters 2 VM-B10R 200uA

Power Supply Parts:
Lundahl LL1651 Transformer 1 LL1651
Hammond 10V Transformer 185G20 2 185G20
Power Supply 80+5uF oil caps 5 Gobal Industrial
Power Input 1 719W-00/04
6AS7/5998 Power Selector Switch (on power supply chassis) 1 SRB23A2BBBNN
Neutrik NL4MP For Umbilical Power - Panel Connectors 4 Neutrik NL4MP
Neutrik NL4FX - Wire Connectors 4 Neutrik NL4FX
Color Rings for NL4FX 2 Neutrik LCR
Power Button (On Power supply chassis) AV1911D712Q04 1 AV1911D712Q04
Weston Round Model Panel Meter DC 0-500 Volts in Original Box 1 Weston 301-57
Weston Round Model Panel Meter 0-500 Milliamperes in Original Box 1 Weston 301 DC 0-500
BAT 46 Diode 2 497-3768-1-ND
Relay SPST-NO (1 Form A) 12VDC Coil Chassis Mount (50.29mm 27.43mm 27.94mm) 1 T9AP1D52-12-ND
CAP FILM 4.7UF 10% 450VDC RADIAL 2 ECW-FE2W475K
470R Resistor 2 Yageo
100R Resistor 2 Yageo
1N4148 Diode 8 1N4148FSCT-ND
10K Trimmer 2 25SR10KLF
NTC Thermister 3 SL12 12102
0.15uF capacitor film through hole 6 ECQ-E2154KF
RC Snubber Resistor 8 Yageo
Shunt Resistor 1

Misc. Parts/Supplies:
Solder 1 QuickChip Silver/Lead/Tin Solder
Wire (18 Guage Red) 600V Rated 1 KSW-18AWG
Power supply circuit boards 8 JLCPCB
2 ton epoxy 1 Devcon 2-Ton
Small heatsinks for inside chassis 7 530002B02500G

Amplifier Section parts :  
Jupiter Capacitors (0.22uF copper) 2 Jupiter Copper Paper in Wax
TC600 175uF capacitors 6 TC175 ClarityCap
Volume Knob 1 Dia40x18H Black ring
Selector Knobs (For Driver tube selector and power tube selector) 1 Dia40x18H Black ring
6as7/6SN7 sockets (Belton 8pin) 7 Belton (8pin)
C3G Sockets 2 USSR C3G Sockets
6J5 Sockets 2 Belton (8pin)
RCA Input 2 Neutrik NF2D-B-
XLR Input 2 Neutrik NC3FP-1-B
Volume Control 1 Acoustic Dimensions 41 Step 100K Stereo 45 x 45 X 53 (75)
TRS Output 1 Neutrik NJ3FP6C-B TRS w/Gold Contacts
4Pin XLR Out 1 Neutrik NC4FP-1-B
3 Pin XLR Headphone Out 2 Neutrik NC3FP-1-B
Canary StarQuad Signal Cable (20ft) 1 Canare L-4E6AT
10K 1/8 watt leakage current resistors (on output) 3 10KYCT-ND
AES Cables (Impedance controlled) (20ft) 1 REdco TGS-D1
Capacitor Clamp 11 CLAMPS-70245
5 Lug Terminal Strips 14
Selector Switch (Voltage, tube type) 1 A30405RNZQ

Tube Socket Related:
HLMP-6000 LED's 14 HLMP-6000
Grid Resistors (RN60) 12 RN55/RN60
Grid Stopper Resistors (RN60) 24 RN55/RN60
Plate Stopper Resistors (RN60) 12 RN55/RN60
Screen Stopper Resistors (RN60) 4 RN55/RN60

21st Century Maida Parts:  
Large Heatsink for Back of chassis 1 Size: 60*150*25mm Aluminum
BC2626-ND 3uF Capacitor 3 BC2626-ND
3 1 C2 2u2/630V Radial, leaded 495-2928-ND 1 3 1 C2 2u2/630V Radial, leaded 495-2928-ND
4 1 C3 10uF X7R 0805 587-2396-1-ND 1 4 1 C3 10uF X7R 0805 587-2396-1-ND
5 1 C5 220nF/630V Radial, leaded EF6224-ND 1 5 1 C5 220nF/630V Radial, leaded EF6224-ND
6 3 D1,D5,D6 1N4007 DO214 641-1018-1-ND 3 6 3 D1,D5,D6 1N4007 DO214 641-1018-1-ND
7 2 D2,D4 10V, low current SOD123 MMSZ4697T1GOSCT-ND 2 7 2 D2,D4 10V, low current SOD123 MMSZ4697T1GOSCT-ND
8 1 D3 SMA6J18A DO214 SMA6J18A-TPMSCT-ND 1 8 1 D3 SMA6J18A DO214 SMA6J18A-TPMSCT-ND
9 2 J1,J2 Terminal block Leaded 609-3937-ND 2 9 2 J1,J2 Terminal block Leaded 609-3937-ND
10 1 Q1 STW12NK95Z TO-247 497-5167-5-ND 1 10 1 Q1 STW12NK95Z TO-247 497-5167-5-ND
11 1 Q1 Thermal pad TO-247 BER178-ND 1 11 1 Q1 Thermal pad TO-247 BER178-ND
12 2 R1,R10 499k 1206 311-499KFRCT-ND 2 12 2 R1,R10 499k 1206 311-499KFRCT-ND
13 1 R2 220R 0805 311-220ARCT-ND 1 13 1 R2 220R 0805 311-220ARCT-ND
14 1 R3 10R/2W Axial, leaded 10W-2-ND 1 14 1 R3 10R/2W Axial, leaded 10W-2-ND
15 1 R4 2k Leaded 3362H-202LF-ND 1 15 1 R4 2k Leaded 3362H-202LF-ND
16 1 R5 953R 0805 311-953CRCT-ND 1 16 1 R5 953R 0805 311-953CRCT-ND
17 1 R6 1k82 0805 311-1.82KCRCT-ND 1 17 1 R6 1k82 0805 311-1.82KCRCT-ND
18 1 R7 137k 0805 311-137KCRCT-ND 1 18 1 R7 137k 0805 311-137KCRCT-ND
19 1 R8 100R 0805 311-100ARCT-ND 1 19 1 R8 100R 0805 311-100ARCT-ND
20 1 R9 200k/3W Axial, leaded PPC200KW-3JCT-ND 1 20 1 R9 200k/3W Axial, leaded PPC200KW-3JCT-ND
21 1 U1 LT3080 SOT-223 LT3080IST#PBF-ND 1 21 1 U1 LT3080 SOT-223 LT3080IST#PBF-ND

Constant Current Source Parts (for 2): 
ixtp01n100d 2 IXTP01N100D
Current set resistor (500ohm) 2 RN55/RN60
Stopper resistor 2 RN55/RN60

Constant Current Sink Parts (for 6):
Tip50C or MJE340 6 Tip50C
2N2222 6 2N2222
HLMP-6000 12 HLMP-6000
24k 2W resistors (2 in series) led bias resistors metal film 12 PPC10KW-3JCT-ND

LV Board Parts (For 2):
16V 68000uF caps 4 Epcos B41231A689M000
20V caps 33000uF caps 4 B41231A5339M000
Rectifiers 8 SBR10E45P5-7DICT-ND
5mm 50V caps 2.2uF 10 495-1127-ND
RC resistors 8 RN55/RN60

High Voltage Rectifier Board Parts:  
RC capacitor 15mm 2 495-4911-1-ND
RC resistor 2 RN55/RN60
3uF filter cap 1 BC2626-ND
Rectifier 1 RS407GL-BPMS-ND

6.3V Regulator Boards:  
LM1084 Regulator 5 LM1084-IT
121R Resistor 5 Yageo
500R Resistor 5 Yageo
1n4002 Diodes 10 ONSemi
100uF 25V tant 5 TAP107K020CCS
  5 TKT151M1005AR

12.6V Regulator Boards :  
LT3081 Regulator 1 LT3081ET7#PBF-ND
47uF 35V Tant Cap 1 TAP476M035CCS
1000uF 16V Electrolytic 105degree cap 1 UPW1C102MPD

3D printed capacitor clamps to hold the large caps in place.

And the new MOSFET that has been added for high voltage regulation is the ON Semiconductor FDH44N50. Rated at close to 700 watt power handling and super fast switching. Can take the heat for a very prolonged slow start.


----------



## leftside (Feb 7, 2020)

The amp can also take L77/6C4 tubes in the 6J5 sockets with adapters. Just waiting for the adapters to arrive from Bulgaria before I try this stash.

Top row:
National Union, long black laddered plate, triple mica, D getter.
Raytheon, long grey laddered plate, D getter.
Sylvania, 1950's, long black laddered plate, D getter, yellow print
Sylvania, 1950's, long black laddered plate, D getter, green print
Sylvania (Heintz branded), 1960's, short grey plate, triple mica, halo getter

Bottom Row:
Mullard short grey plate, military, D getter
Mullard (branded Valvo), short grey plate, "Eagle Crest BMVtdg 468" O getter
GEC, long black laddered plates, D getter
Marconi Osram,  long black laddered plates, D getter
Telefunken? (come with German military boxes indicating made in Britain), short grey plates, "Eagle Crest BMB 448", O getter


----------



## leftside (Feb 20, 2020)

Needles in the dark. 

The background of the meters are actually more of a soft orange color, but my phone video appears to make them white.


----------



## leftside




----------



## leftside (Feb 21, 2020)

Found a perfect fitting set of shelves on the local used market to keep the amps playing nicely together.


----------



## leftside

Started to bring out the adapters tonight. Started with 12AU7 and 12BH7 to 6SN7. Tried a few 12AU7, including early Mullard 12AU7 from 1953 which sounds great in one of my DAC's. Sounds good in the V6, but lacks a bit of the 3D holographic feeling I get with other premium tubes in this amp.  Will be interesting to see how the 6C4 compare when I get my 6C4 to 6J5 adapters.

Tried a Brimar 12BH7 and I was really impressed with this tube. Does it beat the GEC 6J5? No, it doesn't beat it, but very close. Certainly worth a try if you're a tube roller.

If you google 6SN7 vs 12AU7 you will get a lot of differing opinions, and I think the 12AU7 is very dependent on the amp design. This tube amp is a CCS design. I tend to agree with these thoughts here when using these tubes with my amp:
http://oldstockaudio.blogspot.com/2010/02/12au7-12bh7-6cg7-whats-best.html

There's some nice history of these tubes here:
http://www.fourwater.com/files/hist6sn7.txt


----------



## A2029 (Feb 25, 2020)

leftside said:


> Started to bring out the adapters tonight. Started with 12AU7 and 12BH7 to 6SN7. Tried a few 12AU7, including early Mullard 12AU7 from 1953 which sounds great in one of my DAC's. Sounds good in the V6, but lacks a bit of the 3D holographic feeling I get with other premium tubes in this amp.  Will be interesting to see how the 6C4 compare when I get my 6C4 to 6J5 adapters.
> 
> Tried a Brimar 12BH7 and I was really impressed with this tube. Does it beat the GEC 6J5? No, it doesn't beat it, but very close. Certainly worth a try if you're a tube roller.
> 
> ...



The CCS design tends to show off differences in how linear each tube is. 12AU7 is a family of tubes that are known to be less linear. 12AU7 often get chosen to give amps more "color" and ability to roll the tone, but many lack some refinement of other tube types because of their internal construction.

Out of all the 12AU7 brands and variants that I've tried (including 5814A, 5963, 7316, 6680, CV4003 and others) my best sounding tube was an Amparex Bugle Boy from Holland. Lively 3D with sweet highs and nice midrange. 6SN7s and 12BH7s were a step up though. I enjoy listening with RCA 12BH7. Not the most resolving or 3D, but super rich and creamy.

I'm looking forward to trying out these 12GN7 beasts next. Rated at 11.5 watts dissipation in a tube the same size as a 12BH7 (12BH7 rated at only 3.5 watts per plate)! For comparison, a 6AS7 is rated for 13 watts per plate in its much bigger bottle. Video tubes such as the 12GN7 are super linear when triode strapped and have very low distortion (but some say that they can sound almost solid state, so we'll see).


----------



## leftside

Tried out a pair of tubes not talked about too often on here: 6L5G. This pair are National Union with the foil getter. These have a slightly warmer tone than the GEC 6J5G that I had in there previously. Don't quite grab your attention like the GEC, but still very nice. Excellent sound stage and tight bass. Can't complain at $30/pair with boxes. Definitely keepers.


----------



## leftside (Mar 5, 2020)

Some crazy tube rolling... GEC E3375/EL38 to C3g. As if there weren't enough tube rolling possibilities with this amp...

Mischa took a look at the data sheets for these tubes, and thought they might not sound too good, but they are surprisingly fine. Lower gain than GEC L63. I'm having a tough time deciding if they are better or about the same as the L63. I'll have to listen again tomorrow when it is earlier in the evening and I'm less tired. Anyway, the tube rolling possibilities are endless! I'm going to spend a few more evenings rolling in various EL38, EL11, EL3N, etc, but won't post too many more pictures as I think you get the "picture" that there are a lot of tube rolling possibilities with this amp 

Edit: thanks to @Deyan for these adapters.


----------



## A2029

leftside said:


> Some crazy tube rolling... GEC E3375/EL38 to C3g. As if there weren't enough tube rolling possibilities with this amp...
> 
> Mischa took a look at the data sheets for these tubes, and thought they might not sound too good, but they are surprisingly fine. Lower gain than GEC L63. I'm having a tough time deciding if they are better or about the same as the L63. I'll have to listen again tomorrow when it is earlier in the evening and I'm less tired. Anyway, the tube rolling possibilities are endless! I'm going to spend a few more evenings rolling in various EL38, EL11, EL3N, etc, but won't post too many more pictures as I think you get the "picture" that there are a lot of tube rolling possibilities with this amp
> 
> Edit: thanks to @Deyan for these adapters.



Love the look of the E3375 with plate caps; looks cool at the center of the rest of the tubes. Check out where the operating point of the E3375's running in driver duty (Look at the *green line* below). Found this graph of triode curves on the web. The red line intersecting with the blue line at 27mA was for a speaker amp application. These tubes can do 25W dissipation. They are run at ~0.14W in the C3G sockets here, so 0.56% of the dissipation they are capable of. Should last a looooooong time in that position 





Note how the operating point is very close to the bottom where the tube is less linear, but I've learned more and more over time that datasheets don't tell the whole story on how a tube will sound!


----------



## L0rdGwyn

A2029 said:


> Love the look of the E3375 with plate caps; looks cool at the center of the rest of the tubes. Check out where the operating point of the E3375's running in driver duty (Look at the *green line* below). Found this graph of triode curves on the web. The red line intersecting with the blue line at 27mA was for a speaker amp application. These tubes can do 25W dissipation. They are run at ~0.14W in the C3G sockets here, so 0.56% of the dissipation they are capable of. Should last a looooooong time in that position
> 
> 
> 
> Note how the operating point is very close to the bottom where the tube is less linear, but I've learned more and more over time that datasheets don't tell the whole story on how a tube will sound!



Well hey, if you are gonna run them with 3mA on the plates, that is the place to do it!


----------



## leftside

I have a friend coming over tonight who knows absolutely nothing about tubes. I'll ask him what setting he prefers (without telling him which tubes are in operation) and see what he thinks.


----------



## A2029

How do you find the Mullard 6080's in this amp vs. the other 6080s/6AS7s in your collection @leftside?

I've tried the Mullard before in another amp and found it warm/lush, but sold it as I preferred the bigger soundstage of other tubes. I actually find cheap tubes such as the 6H13C's to be pretty decent for the price to my ears, but I've never had the pleasure to try out 5998s or GEC 6AS7s.


----------



## leftside

A2029 said:


> How do you find the Mullard 6080's in this amp vs. the other 6080s/6AS7s in your collection @leftside?
> 
> I've tried the Mullard before in another amp and found it warm/lush, but sold it as I preferred the bigger soundstage of other tubes. I actually find cheap tubes such as the 6H13C's to be pretty decent for the price to my ears, but I've never had the pleasure to try out 5998s or GEC 6AS7s.


I love them in this amp. With the WA22 I thought they were actually a little lightweight, but in the V6 "Thunder" I think they are perfect - definitely not warm or overly lush in this amp. Two is no good with the LCD4. Definitely better with four or six. Will roll in some of the "premium" power tubes again later to compare, but currently going through my driver tubes whenever I get the chance. I haven't even tried the GEC 6AS7G yet.... I remember the TS 5998 definitely made Thunder even more "Thunderous"


----------



## A2029 (Mar 5, 2020)

L0rdGwyn said:


> Well hey, if you are gonna run them with 3mA on the plates, that is the place to do it!



True, I wonder if they would sound as good if run within this area of the curves


----------



## mordy

A2029 said:


> How do you find the Mullard 6080's in this amp vs. the other 6080s/6AS7s in your collection @leftside?
> 
> I've tried the Mullard before in another amp and found it warm/lush, but sold it as I preferred the bigger soundstage of other tubes. I actually find cheap tubes such as the 6H13C's to be pretty decent for the price to my ears, but I've never had the pleasure to try out 5998s or GEC 6AS7s.


Hi A2029,
I was under the impression that the driver tubes are the ones mainly responsible for the size and shape of the soundstage. Are you saying that the power tubes impact the sound stage as well?


----------



## A2029 (Mar 5, 2020)

mordy said:


> Hi A2029,
> I was under the impression that the driver tubes are the ones mainly responsible for the size and shape of the soundstage. Are you saying that the power tubes impact the sound stage as well?



Driver tubes have the much bigger impact on amplifier tone/soundstage, but output tubes do contribute as well, just not quite as much.

In a perfect world you could have the driver tube do the voltage amplification and add a bit of character (e.g. harmonics, etc.), then have a perfect "buffer" that just takes that signal and adds current to it without adding or removing any harmonics, and without adding noise. When I finish working on a KT150 based SET amp build that I'm currently finishing up, just such a tube + buffer amp will be my next build. The buffer won't ever be "perfect" though as that is not possible in the physical world!


----------



## leftside

Well after an extensive listening session this evening, my friend declared the L63 the winner. Better midrange and treble, and I agree. But, the differences weren't huge. Sure would like to hear the E3375 in an amp made for it.

Also played the same tracks at the same time on vinyl and through the DAC. Asked my friend to pick a winner, and he couldn't. Best he could come up with was that he would need more time on his own to decide, and that there were definitely "differences", but couldn't say which was "better". Accused me of "f**king with him" when I was switching between the two input sources via the preamp remote


----------



## Xcalibur255

A2029 said:


> Driver tubes have the much bigger impact on amplifier tone/soundstage, but output tubes do contribute as well, just not quite as much.
> 
> In a perfect world you could have the driver tube do the voltage amplification and add a bit of character (e.g. harmonics, etc.), then have a perfect "buffer" that just takes that signal and adds current to it without adding or removing any harmonics, and without adding noise. When I finish working on a KT150 based SET amp build that I'm currently finishing up, just such a tube + buffer amp will be my next build. The buffer won't ever be "perfect" though as that is not possible in the physical world!



VERY interested in hearing more about the KT150 build if you are open to sharing more information about it.  I was strongly considering taking this route myself, but life has forced me to push "pause" on new audio purchases for now.


----------



## Xcalibur255

A2029 said:


> I've never had the pleasure to try out 5998s or GEC 6AS7s.



This is just my opinion, but I find the 5998 to be a highly mis-characterized tube.  99% of the listening impressions you read are from people who have the tube poorly biased.  The sound of the 5998 changes a lot with operating points, and when ideally biased it is an amazing sounding tube.  I don't know if this makes any sense, but "bold without being loud" is kind of how I would put it.  It's both refined and brings out the delicacy in music but somehow at the same time is ballsy and huge in dynamics.  With the other tubes in this family of voltage regulators I find you have to pick one sound or the other, only the 5998 lets you have both at the same time.  It's a shame most people don't know how great this tube is, it runs so under-biased in the 6AS7 OTL amps people drop them into.


----------



## A2029

Xcalibur255 said:


> VERY interested in hearing more about the KT150 build if you are open to sharing more information about it.  I was strongly considering taking this route myself, but life has forced me to push "pause" on new audio purchases for now.



Will share more on the KT150 SET build as I work on it some more this weekend (and hopefully finish it).


----------



## A2029

Xcalibur255 said:


> This is just my opinion, but I find the 5998 to be a highly mis-characterized tube.  99% of the listening impressions you read are from people who have the tube poorly biased.  The sound of the 5998 changes a lot with operating points, and when ideally biased it is an amazing sounding tube.  I don't know if this makes any sense, but "bold without being loud" is kind of how I would put it.  It's both refined and brings out the delicacy in music but somehow at the same time is ballsy and huge in dynamics.  With the other tubes in this family of voltage regulators I find you have to pick one sound or the other, only the 5998 lets you have both at the same time.  It's a shame most people don't know how great this tube is, it runs so under-biased in the 6AS7 OTL amps people drop them into.



Agreed on the 5998 bias. I believe the Bottlehead Crack runs the tubes at around 30-35mA which runs them at something like 25-30% of their max (pretty cold running). I thought about that while designing @leftside's amp to be able to take both 6AS7 and 5998s. The 6AS7 and 5998s both run at about 65-75% of their max in his amp which I think is a nice sweetspot for longevity, high power production, and optimal bias point.


----------



## Xcalibur255

I bet the 5998 sounds awesome in the "Thunder V6" with that kind of biasing.  Personal preference always plays a part but I have always really liked the tonal balance and overall presentation of the 5998 when it's getting enough juice.


----------



## leftside

Xcalibur255 said:


> I bet the 5998 sounds awesome in the "Thunder V6" with that kind of biasing.  Personal preference always plays a part but I have always really liked the tonal balance and overall presentation of the 5998 when it's getting enough juice.


Now I've had the Mullards in for a while, and am used to their sound in this amp, I'm going to roll the TungSol's in again this weekend. I must remember to flick the 5998 switch on the front of the amp!


----------



## leftside

Was rolling some of the more expensive drivers this evening. I do believe the coke bottle GEC 6J5G sound better than the metal base L63, but I don't think there is much in it. Just sound like the instruments with the coke bottle have a little more force than the metal base counterparts.

6J5G vs early Mullard foil getter ECC32? That's a tough one - have to give a very slight edge to the ECC32, but ask me another day and I might change my mind.

Also tried the EL3N in the 6J5 sockets with adapters. Very nice. A little warmer than the earlier tubes mentioned, with perhaps a bit of clarity lost. Worth having for a change of sound. I think Glenn finds the same in one of the amps he builds.

So how about the power tubes? Well to be honest, I'm not finding too much difference between the various brands/makes. More power with 5998. Mischa told me this evening this is what he would have expected from the amp design. There is a marked difference with the LCD4's though when going from 2 to 4 power tubes, but not much difference from 4 to 6.


----------



## chrisdrop

leftside said:


> Was rolling some of the more expensive drivers this evening. I do believe the coke bottle GEC 6J5G sound better than the metal base L63, but I don't think there is much in it. Just sound like the instruments with the coke bottle have a little more force than the metal base counterparts.
> 
> 6J5G vs early Mullard foil getter ECC32? That's a tough one - have to give a very slight edge to the ECC32, but ask me another day and I might change my mind.
> 
> ...


I do love this thread FYI. Beautiful amp. Given what seems to be a pretty deep tube-stash, you are in for eons of fun.


----------



## leftside

Compared my different ECC32 tubes tonight. Foil, pan and D getter. The good news is if you're looking for one of these to purely listen to, and not necessarily collect, they all sound the same - well at least in my amp. The latter D getters tend to be a little cheaper than the earlier foil or pan getters. These are absolutely some of the best drivers out there. I can't think of anything I don't like about them - and the bass with this amp is superb. Spun up tonight with 4 Tungsol 5998 and a pair of Bendix 6080.

Having listened further to the various power tubes, I do think I am hearing a slight difference with the TS 5998 over the 6AS7 and 6080 family of tubes. These are my preference right now - even more than the GEC 6AS7G - in this amp. It might be because there is extra gain with the 5998. Further listening is required.... which is fine by me 

Mischa, the power section runs cooler when running the 5998's and the 5998 switch engaged. I like this, but I would have expected the amp to have run warmer with this setting/tubes. Shows what I know...


----------



## A2029 (Mar 11, 2020)

leftside said:


> Compared my different ECC32 tubes tonight. Foil, pan and D getter. The good news is if you're looking for one of these to purely listen to, and not necessarily collect, they all sound the same - well at least in my amp. The latter D getters tend to be a little cheaper than the earlier foil or pan getters. These are absolutely some of the best drivers out there. I can't think of anything I don't like about them - and the bass with this amp is superb. Spun up tonight with 4 Tungsol 5998 and a pair of Bendix 6080.
> 
> Having listened further to the various power tubes, I do think I am hearing a slight difference with the TS 5998 over the 6AS7 and 6080 family of tubes. These are my preference right now - even more than the GEC 6AS7G - in this amp. It might be because there is extra gain with the 5998. Further listening is required.... which is fine by me
> 
> Mischa, the power section runs cooler when running the 5998's and the 5998 switch engaged. I like this, but I would have expected the amp to have run warmer with this setting/tubes. Shows what I know...



The 5998's have a lower heater current, so less current to be regulated within the power supply, and less heat. The higher voltage on the 5998 setting means that less voltage needs to be dropped in the power supply, so less heat produced in the power supply. More voltage on the tubes means more heat from the tubes themselves (but the tubes can take the heat as they are still only running at 65-75% of their max dissipation) 

Would you say that the ECC32 is better than 6J5 variants? What driver tube have you found to be best so far? 

I'm trying to narrow down tube socket choices for my next hybrid amp but there are so many darn choices. Right now I'm leaning towards a 6SN7 socket, a pair of 12BY7 sockets, and a pair of 6J5 sockets.


----------



## whirlwind

leftside said:


> Compared my different ECC32 tubes tonight. Foil, pan and D getter. The good news is if you're looking for one of these to purely listen to, and not necessarily collect, they all sound the same - well at least in my amp. The latter D getters tend to be a little cheaper than the earlier foil or pan getters. These are absolutely some of the best drivers out there. I can't think of anything I don't like about them - and the bass with this amp is superb. Spun up tonight with 4 Tungsol 5998 and a pair of Bendix 6080.
> 
> Having listened further to the various power tubes, I do think I am hearing a slight difference with the TS 5998 over the 6AS7 and 6080 family of tubes. These are my preference right now - even more than the GEC 6AS7G - in this amp. It might be because there is extra gain with the 5998. Further listening is required.... which is fine by me
> 
> Mischa, the power section runs cooler when running the 5998's and the 5998 switch engaged. I like this, but I would have expected the amp to have run warmer with this setting/tubes. Shows what I know...




Very nice and I could not agree more about both the 5998 power tubes, and the Mullard ECC32

This is one of my favorite combos in my GOTL and to be honest you can roll hundreds of tubes IMO and not beat this combo.
This amp looks killer


----------



## leftside

A2029 said:


> The 5998's have a lower heater current, so less current to be regulated within the power supply, and less heat. The higher voltage on the 5998 setting means that less voltage needs to be dropped in the power supply, so less heat produced in the power supply. More voltage on the tubes means more heat from the tubes themselves (but the tubes can take the heat as they are still only running at 65-75% of their max dissipation)
> 
> Would you say that the ECC32 is better than 6J5 variants? What driver tube have you found to be best so far?
> 
> I'm trying to narrow down tube socket choices for my next hybrid amp but there are so many darn choices. Right now I'm leaning towards a 6SN7 socket, a pair of 12BY7 sockets, and a pair of 6J5 sockets.


My slight preference is ECC32. But, 6J5 are plentiful and you can still find NOS of even the most popular 6J5 including the GEC. Good luck finding a NOS ECC32. 6SN7 and 6J5 gives you the best of both worlds and plenty of tube rolling options - for example 6N7 in the 6J5 sockets. I also like the C3g because it sounds quite different to the 6SN7/6J5 family of tubes. 12BY7 would also be a great option!

I've had the V6 Thunder for a few months now and there's nothing I would change.


----------



## L0rdGwyn

Great impressions @leftside , assuming comparisons are apples-to-apples across different amplifiers, agree with you on the different ECC32 variants (I only have D and foil getter, black plates), they sound the same to me by and large.  I have found the shouldered GEC L63 to have the larger soundstage than the ECC32, but the ECC32 has an absolutely addictive warm tonality and certainly doesn't lack for soundstage itself.  I don't know if I could rank them, but easily two of the best drivers I have ever heard.  Does the same soundstage pattern hold true in the V6?

On NOS ECC32 availability, if you are willing to take some risk, I have had some success in the Japanese tube market.  I have gotten NOS pairs of ECC32 for around $300 USD + shipping.  Sounds like a lot, but that is a crazy good price for these tubes.  Not the greatest time to pursue this, but it is an option!


----------



## cedboe (Apr 1, 2020)

Hey there !

Showing here my amp. I bought it from Mischa last year, it's my first OTL but I can say it sounds as good as a high-end amp (my speaker setup is very high-end), so silent, detailed, fast but still sounding natural ! Amazing with my Eikons ! I mostly listen to vinyl. Thanks so much Mischa !!! Keep on the great work !!

The wave is my wall carpet, it's not on the amp  But I love the effect !


----------



## A2029

cedboe said:


> Hey there !
> 
> Showing here my amp. I bought it from Mischa last year, it's my first OTL but I can say it sounds as good as a high-end amp (my speaker setup is very high-end), so silent, detailed, fast but still sounding natural ! Amazing with my Eikons ! I mostly listen to vinyl. Thanks so much Mischa !!! Keep on the great work !!
> 
> The wave is my wood carpet, it's not on the amp  But I love the effect !



That's a really cool reflective effect of the wall hanging you have above it!


----------



## leftside

Been rolling in a few metal base 6J5GT's this weekend. Ken-Rad, Mullard, GEC, Fivres, Mullard, TungSol's, Brimar and Sylvania's. What can I say. They all sound superb. Try out the Ken-Rads - they are usually super cheap! I'm currently running the TungSol black ladder plate, foil getter. I'll probably leave these in for a while


----------



## A2029

leftside said:


> Been rolling in a few metal base 6J5GT's this weekend. Ken-Rad, Mullard, GEC, Fivres, Mullard, TungSol's, Brimar and Sylvania's. What can I say. They all sound superb. Try out the Ken-Rads - they are usually super cheap! I'm currently running the TungSol black ladder plate, foil getter. I'll probably leave these in for a while



Looks awesome! Do the 5998s give the amp more of their signature, or is the sound somewhere in between the 6080 and 5998?


----------



## leftside

A2029 said:


> Looks awesome! Do the 5998s give the amp more of their signature, or is the sound somewhere in between the 6080 and 5998?


I'll compare 6080 vs 5998 tonight


----------



## leftside (Apr 7, 2020)

A2029 said:


> Looks awesome! Do the 5998s give the amp more of their signature, or is the sound somewhere in between the 6080 and 5998?


Tried the 5998 vs the Bendix and I preferred the 5998 in this amp with the LCD4.

Been going down the 6N7 rabbit hole tonight and comparing against the 6J5. First of all, the 6N7 have way more gain than the 6J5. Had to decrease the volume about 20% to get the same volume level as the 6J5.

First up, the Visseaux. Not quite as good as the TS 6J5GT imo. Just sounded a little flatter. At first I thought it might be the 6N7 in general in this amp, so I bought out some of my favorites from previous amps - a pair of 1940's Fivre 6N7G. Oh yes - these are still really good. Right up there with the 6J5 - perhaps slightly more dynamic/fresher with a tiny less amount of warmth. Not that I consider the 6J5 warm... I think the Visseaux might simply have been abused too much in a previous life.

Next up - early foil getter Mullard ECC31. I still prefer the Fivre's. I'm going to have to try the NU, KenRad, Sylvania, TungSol 6N7 at some point.

Gratuitous photo of all the big tubes at once.


----------



## whirlwind

leftside said:


> Been rolling in a few metal base 6J5GT's this weekend. Ken-Rad, Mullard, GEC, Fivres, Mullard, TungSol's, Brimar and Sylvania's. What can I say. They all sound superb. Try out the Ken-Rads - they are usually super cheap! I'm currently running the TungSol black ladder plate, foil getter. I'll probably leave these in for a while




Oh my!  I bet the bass slam sound powerful with all of those 5998's


----------



## leftside

whirlwind said:


> Oh my!  I bet the bass slam sound powerful with all of those 5998's


Yeah can be a bit crazy on bass heavy tracks.


----------



## whirlwind

leftside said:


> Yeah can be a bit crazy on bass heavy tracks.




LOL! You inspired me to listen to my GOTL with the 5998 and the Atty!
I really dig these tubes.

I really like how your amp is laid out with the tubes and switches, great idea.  Talk about tube rolling possibilities!


----------



## leftside (Apr 26, 2020)

Did an extended session this afternoon listening to new (to me vinyl). Compared Mullard 6080 to TungSol 5998. Was also running the Glenn 300B for 2 reasons: 1) As a benchmark/source of reference and 2) So I could still listen to music whilst waiting for tubes to cool down between rolling.

In my Woo WA22 I much preferred the TS 5998 over the Mullard 6080. But, in Thunder I think they are a little too much (bass) when listening to bass heavy music such as Morcheeba. I'm going to leave the Mullard 6080 in for the time being. The TungSols will be bought back in when I feel the tunes need a bit more bass.



Edit: I would like to add that the drivers used were Mullard ECC32 or Fivre 6N7G. Both have very, very good strong bass and more gain than a regular 6SN7 or 6J5. But combined with 6 TS 5998 (which also have more gain) and bass heavy tracks, it's simply "too much of a good thing".


----------



## leftside

It’s a Mullard and Underworld evening. Mullard 6080 and 6C5G.


----------



## Velozity

@leftside did you ever try the 6C4 in this amp?  Curious as to your impressions of it.


----------



## leftside

Velozity said:


> @leftside did you ever try the 6C4 in this amp?  Curious as to your impressions of it.


I did indeed. I think I posted my thoughts a page or two back. I really like the 12AU7 in one of my DAC's, but the 6C4 wasn't the best fit for Thunder. Felt a little subdued, but like I said I know the 12AU7/6C4 sound great in other pieces of equipment. Really enjoying Mullard 6C5G at the moment.


----------



## leftside (May 1, 2020)

Bought out the C3g driver tubes tonight. They have a wonderful freshness/cleanliness, but perhaps don't have the magical mids or as deep bass of the 6C5/6J5 tubes. I think others with amps that have compared the two also experience something similar. Really good for some added airiness and cleanliness to heavy hard techno that I sometimes listen to.


----------



## leftside

One of the unexpected things with this amp was finding out the 6J5 sockets could also be used for 6N7G tubes.

I tried a 6N7G in the 6SN7 socket (with adapter) and it sounds half dead compared to when it’s paired with another 6N7G in the 6J5 sockets. I ordered a bunch of tubes from a guy in France recently, and was going to roll in a bunch of different 6N7G this evening - but these early Mazda foil getters will be staying put. At least for one evening. 🙂


----------



## L0rdGwyn

leftside said:


> One of the unexpected things with this amp was finding out the 6J5 sockets could also be used for 6N7G tubes.
> 
> I tried a 6N7G in the 6SN7 socket (with adapter) and it sounds half dead compared to when it’s paired with another 6N7G in the 6J5 sockets. I ordered a bunch of tubes from a guy in France recently, and was going to roll in a bunch of different 6N7G this evening - but these early Mazda foil getters will be staying put. At least for one evening. 🙂



How do you like a pair of 6N7G compared to the TOTL 6J5 @leftside ?  I've thought about giving it a try in my 45 amp.


----------



## leftside

L0rdGwyn said:


> How do you like a pair of 6N7G compared to the TOTL 6J5 @leftside ?  I've thought about giving it a try in my 45 amp.


Good question. I'll do a compare tomorrow evening. 6N7G definitely have more gain. Obviously, if you can build an amp to take both in the same sockets that would be ideal. Both are definitely great tubes. From a purely aesthetic reason, the Mazda 6N7G have a nice glow


----------



## L0rdGwyn

leftside said:


> Good question. I'll do a compare tomorrow evening. 6N7G definitely have more gain. Obviously, if you can build an amp to take both in the same sockets that would be ideal. Both are definitely great tubes. From a purely aesthetic reason, the Mazda 6N7G have a nice glow



Thanks! I'll look forward to it.  Curious if there is some sonic advantage, I would definitely be interested in giving it a try, a pretty simple wiring change.  The Mazda 6N7G is a nice looking tube, and so is the Fivre 6N7G, still have a small collection of these from the GOTL, haven't heard them with the two sections paralleled, I think this is the more common way they are used given the shared cathode.


----------



## leftside (May 7, 2020)

Mazda 6N7G vs Fivre 76 vs Osram L63:

The Mazda 6N7G have more gain. More pronounced/heavier bass. Slightly warmer. Sweet minds. Perhaps have more of that typical romantic "tubey" (?) sound.

Fivre 76. First time I've ever listened to a 76 as my 76 to 6J5 adapters only arrived today. Love it. Super dynamic, detailed, tight bass.
"Crisp and clear" are words that spring to mind. Others might argue these are a little "lightweight" compared to the Mazda 6N7G.

Osram L63. Closer to the 76 than the 6N7G. Perhaps slightly more detail, and slightly more revealing. 

Soundstage and imaging seemed to be about equal.

Need to pull out my other 76 tubes... see if the US versions are just as good....


----------



## Zachik

leftside said:


> Mazda 6N7G vs Fivre 76 vs Osram L63


I am confused... 6N7G is Double Triode, whereas 76 and L63 are Single Triode. So, did you compare 1 x 6N7G vs. 2 x 76 vs. 2 x L63 ?


----------



## chrisdrop

Oooh. Those pairs are all beautiful. Looks like 76 is ~6P5 with a different base? More tubes and adapters to find! 

A few questions:

GT vs G. Same brand/era - Do you expect similar or different sound-wise? 
M-OV (Marconi-Osram Valve Company) GEC. There are several related brands in there. Do you expect them to all sound the same or different? I assume at some point they were independent (different) and at some point they conglomerated and therefore may just have been relabelling of the same valves. Due to this lack of my understanding, I haven't gotten similar tubes across the different brands.


----------



## whirlwind (May 8, 2020)

leftside said:


> Mazda 6N7G vs Fivre 76 vs Osram L63:
> 
> The Mazda 6N7G have more gain. More pronounced/heavier bass. Slightly warmer. Sweet minds. Perhaps have more of that typical romantic "tubey" (?) sound.
> 
> ...




Thanks for this comparison, good stuff!


----------



## A2029

Zachik said:


> I am confused... 6N7G is Double Triode, whereas 76 and L63 are Single Triode. So, did you compare 1 x 6N7G vs. 2 x 76 vs. 2 x L63 ?



In his amp he can plug the 6N7 tubes directly into the 6J5 sockets. It parallels the sections to form an overall single triode. He can also use an 6N7 to 6SN7 adapter to use a single 6N7 in the 6SN7 socket (run on the 6SL7 setting for biasing).


----------



## leftside

A2029 said:


> In his amp he can plug the 6N7 tubes directly into the 6J5 sockets. It parallels the sections to form an overall single triode. He can also use an 6N7 to 6SN7 adapter to use a single 6N7 in the 6SN7 socket (run on the 6SL7 setting reyfor biasing).


Which I've yet to try. Will be interesting to compare 2 * 6N7 in the 6J5 sockets vs 1 * 6N7 in the 6SN7 socket (on the 6SL7 setting). Which reminds me.... I really need to find the time to try the 6SL7'a and 12SL7's.


----------



## leftside (May 8, 2020)

chrisdrop said:


> Oooh. Those pairs are all beautiful. Looks like 76 is ~6P5 with a different base? More tubes and adapters to find!
> 
> A few questions:
> 
> ...


The early L63/6J5 ST MOV tubes all sound about the same to my ears. Looks like they made the ST type from 1945 - 1952 before the black base "tube type"/thinner tubes were made. Cup getter first, then D getter. Then brown base.

It was @gibosi who introduced me to the 76 tubes over on the GOTL thread. I think he really likes them (as I do too).


----------



## Zachik

A2029 said:


> In his amp he can plug the 6N7 tubes directly into the 6J5 sockets. It parallels the sections to form an overall single triode. He can also use an 6N7 to 6SN7 adapter to use a single 6N7 in the 6SN7 socket (run on the 6SL7 setting for biasing).





leftside said:


> Which I've yet to try. Will be interesting to compare 2 * 6N7 in the 6J5 sockets vs 1 * 6N7 in the 6SN7 socket (on the 6SL7 setting). Which reminds me.... I really need to find the time to try the 6SL7'a and 12SL7's.


Thanks for the clarification. Interesting stuff!!



leftside said:


> The early L63/6J5 ST MOV tubes all sound about the same to my ears. Looks like they made the ST type from 1945 - 1952 before the black base "tube type"/thinner tubes were made. Cup getter first, then D getter. Then brown base.
> 
> It was @gibosi who introduced me to the 76 tubes over on the GOTL thread. I think he really likes them (as I do too).


VERY nice collection! <jealous>


----------



## leftside (May 9, 2020)

Received a bunch of tubes from France last week. Some of the pins were rather dirty. I cleaned up 4 6C5V tubes: 3 RT and 1 Miniwatt. It took me over an hour. I'm thinking to myself "is this really worth the effort for 6 euro tubes?!" I'm happy to say it was. These RT 6C5V tubes are super sweet sounding.
https://www.radiomuseum.org/tubes/tube_6c5v.html

Here's one where the pin on the left has been cleaned up, and the pins on the right hadn't yet.


----------



## leftside

The VU meters proved very useful this afternoon. I inserted new (to me) tubes and as the amp was warming up I noticed the right VU meter go very high and stay there. Obviously it shouldn’t move at all with no music playing. This immediately told me “do not insert headphone cable.” I shut down the amp and inserted other tubes and all was good.
Potentially saved a headphone driver.


----------



## mordy

Do you think by for example heating up the tube pins you would be able to see a change on the meters if the tube became better behaved?


----------



## A2029 (Jun 21, 2020)

mordy said:


> Do you think by for example heating up the tube pins you would be able to see a change on the meters if the tube became better behaved?



It was likely because of a short that the meter would fly to full scale like that, so another good reason to check tubes for shorts after shipping.

Edit: A quick and dirty way to check tubes for shorts upon arrival is to look up the datasheet for the tube for its "Basing Diagram" then use a multimeter to check for shorted pins. For instance, on the 6J5 tubes only pins 2 and 7 should show as connected. Many multimeters have a diode test/beep function so you can get an audible beep when there's a connection between the probe tips.


----------



## leftside (Jul 10, 2020)

Super heavy bass and low end with these Telefunken EL11. Perhaps a little too much -  but would be great for music that needs it. Certainly not this track though. This is better with the Fivre 76.


----------



## mordy

In my GOTL I use the ST type TFK EL11 with a RCA 6N7G + a pair of Bendix 6080WB. Somehow this combination hits all the right spots and I am truly enjoying the sound.
Tried the tubular TFK EL11 (from the 50's) that are in your picture - also very good but with the above combination the older 40's ST EL11 are better sounding.
As always - YMMV.....


----------



## chrisdrop

leftside said:


> Super heavy bass and low end with these Telefunken EL11. Perhaps a little too much -  but would be great for music that needs it. Certainly not this track though. This is better with the Fivre 76.



Are all of those tubes run in parallel, or does the switch turn some on/off?


----------



## leftside

mordy said:


> In my GOTL I use the ST type TFK EL11 with a RCA 6N7G + a pair of Bendix 6080WB. Somehow this combination hits all the right spots and I am truly enjoying the sound.
> Tried the tubular TFK EL11 (from the 50's) that are in your picture - also very good but with the above combination the older 40's ST EL11 are better sounding.
> As always - YMMV.....


I think I see what you're doing there in the GOTL with those tubes. Great tubes to have in the toolbelt for sure. I know @UntilThen liked them a lot as well before he went all sane on us and stopped tube rolling. I also have the more slender ST type and the more bulbous ST type.

I'd really like to hear the Tele EL11's in a circuit designed for them (which is certainly not my current amp). @whirlwind or @Zachik have you tried them in the GLE3N? @A2029 I presume they will work well as powers in the EL34/KT66 amp (with EL11 to EL34 adapters).

I know different manufacturers and years have different sonics, but at a very high-level In my amp I'm finding the following (from light/airy to oomph/bass). Oomph is a technical term btw.
76/6C5, 6J5, 6SL7, 6N7, EL11/EL3N. 6J5 being the most neutral.  And as @mordy rightfully says "my amp, my gear, YMMV". I'm not even sure I should include the EL11/EL3N here as my amp certainly wasn't designed for them, and I'm fairly sure they would sound different in an amp designed for them. 

Disclaimer: The 6SL7 and 6N7 have higher gain (certainly in my amp). My findings are far from scientific. I haven't done any measurements - apart from with my ears with multiple different sets of recordings. Possibly under the slight influence of a single malt or a vape with a live resin.


----------



## leftside

chrisdrop said:


> Are all of those tubes run in parallel, or does the switch turn some on/off?


The switch simply turns on the appropriate driver tubes. They are not run at the same time/in parallel. The power tubes can be run at the same time. I'm currently running 4 TS 5998 and 2 Bendix 6080 - which works great with the LCD-4. For more sensitive headphones it's best just to run 2 power tubes.


----------



## mordy

That's some serious horse power - 20A?


----------



## whirlwind

leftside said:


> I think I see what you're doing there in the GOTL with those tubes. Great tubes to have in the toolbelt for sure. I know @UntilThen liked them a lot as well before he went all sane on us and stopped tube rolling. I also have the more slender ST type and the more bulbous ST type.
> 
> I'd really like to hear the Tele EL11's in a circuit designed for them (which is certainly not my current amp). @whirlwind or @Zachik have you tried them in the GLE3N? @A2029 I presume they will work well as powers in the EL34/KT66 amp (with EL11 to EL34 adapters).
> 
> ...




I have not tried the EL11  in my SET amp, I would need EL3N to EL11 adapters.

I don't think I will be trying them as I am in the midst of upgrading my headphones and headphone cables and for once tubes or amps have not gotten in the way.


----------



## Monsterzero

whirlwind said:


> I am in the midst of upgrading my headphones


Is there a VC in your future?


----------



## A2029

mordy said:


> That's some serious horse power - 20A?



Absolute max heater current in his amp is a massive 20 amps, DC, fully regulated. Heck of a lot of heat and heavy iron - why his amp needs the separate power supply chassis.


----------



## A2029

leftside said:


> I'd really like to hear the Tele EL11's in a circuit designed for them (which is certainly not my current amp). @whirlwind or @Zachik have you tried them in the GLE3N? @A2029 I presume they will work well as powers in the EL34/KT66 amp (with EL11 to EL34 adapters).



I'd likely need to implement some kind of biasing switch for the EL11 vs EL34/KT66 to have them both function at their optimal operating point (for most power/best sound).


----------



## whirlwind

Monsterzero said:


> Is there a VC in your future?



Yes indeed there is.


----------



## L0rdGwyn

leftside said:


> I think I see what you're doing there in the GOTL with those tubes. Great tubes to have in the toolbelt for sure. I know @UntilThen liked them a lot as well before he went all sane on us and stopped tube rolling. I also have the more slender ST type and the more bulbous ST type.
> 
> I'd really like to hear the Tele EL11's in a circuit designed for them (which is certainly not my current amp). @whirlwind or @Zachik have you tried them in the GLE3N? @A2029 I presume they will work well as powers in the EL34/KT66 amp (with EL11 to EL34 adapters).
> 
> ...



Beautiful tubes.  I love the Telefunken logo, I think it is a masterwork of graphic design, very crisp on the left pair.  I've had an interest in trying these tubes lately, your pic has pushed me over the edge, I'm buying a pair!


----------



## L0rdGwyn

A2029 said:


> Absolute max heater current in his amp is a massive 20 amps, DC, fully regulated. Heck of a lot of heat and heavy iron - why his amp needs the separate power supply chassis.



Any idea of the output impedance Mischa with all six tubes in place?


----------



## leftside

whirlwind said:


> Yes indeed there is.


Nice! As we are both fans of Audeze, I'd be very interested in your opinion on those. They definitely have my interest based upon what everyone else says about them. I had the Auteur for a while, but I think perhaps my expectations were too high, and so I sold them.


----------



## Monsterzero

leftside said:


> Nice! As we are both fans of Audeze, I'd be very interested in your opinion on those. They definitely have my interest based upon what everyone else says about them. I had the Auteur for a while, but I think perhaps my expectations were too high, and so I sold them.


Im guessing you will like the VC with the Universe non-perf pads. It makes the VC warmer and with more bass at the cost of some staging width,depth and height.
I personally prefer the auteur non perf pads,which make the VC sound most closely to the auteur,which i also sold.


----------



## leftside

L0rdGwyn said:


> Any idea of the output impedance Mischa with all six tubes in place?


https://www.head-fi.org/threads/1101-audio-custom-crafted-headphone-amps.919425/page-2#post-15317173


----------



## L0rdGwyn

leftside said:


> https://www.head-fi.org/threads/1101-audio-custom-crafted-headphone-amps.919425/page-2#post-15317173



Whoops, thanks for the link!  That was my birthday, maybe I was off eating cake and ice cream


----------



## L0rdGwyn (Jul 10, 2020)

L0rdGwyn said:


> Beautiful tubes.  I love the Telefunken logo, I think it is a masterwork of graphic design, very crisp on the left pair.  I've had an interest in trying these tubes lately, your pic has pushed me over the edge, I'm buying a pair!



I shouldn't have hesitated, someone beat me to this nice pair of Tele's.  The seller is a Head-Fier, I PM'd him to see if I could save him eBay fees, too slow 

https://www.ebay.com/itm/114270259204

I am bidding on these Valvos, you've been warned!

https://www.ebay.com/itm/313129349252


----------



## UntilThen

leftside said:


> I know @UntilThen liked them a lot as well before he went all sane on us and stopped tube rolling. I also have the more slender ST type and the more bulbous ST type.
> 
> I'd really like to hear the Tele EL11's in a circuit designed for them (which is certainly not my current amp).



So would I love to hear the EL11, EL12, EL12 spez in an amp designed for them. Someday when I become insane again, I'll pull out those Telefunken and Siemen tubes and get an amp build for it.  

EL11 as drivers and EL12 spez as powers.


----------



## UntilThen

L0rdGwyn said:


> I shouldn't have hesitated, someone here beat me to this nice pair of Tele's.  The seller is a Head-Fier, I PM'd him to see if I could save him eBay fees, too slow
> 
> https://www.ebay.com/itm/114270259204
> 
> ...



Lovely tubes. I have 4 pairs of those in Telefunken and Siemens branding. 3 other pairs in some other branding. I first heard these tubes in Felix Audio Elise tube amp .... in an amp that wasn't supposed to be able to run them but they show great potential and sounded great. Imagine in an amp specially designed to run these tubes.


----------



## L0rdGwyn (Jul 10, 2020)

UntilThen said:


> Lovely tubes. I have 4 pairs of those in Telefunken and Siemens branding. 3 other pairs in some other branding. I first heard these tubes in Felix Audio Elise tube amp .... in an amp that wasn't supposed to be able to run them but they show great potential and sounded great. Imagine in an amp specially designed to run these tubes.



The EL11 at least are equivalent to the EL3, with the proper adapter they should be able to be run optimally in Glenn's EL3N amp.  I do wonder how the EL12 sound, I have never come across triode curves for them.  You will have to let us know if that amp is built  with the high gain of the EL11, I think they would be fun to try in a little "spud" parafeed amplifier.


----------



## leftside

L0rdGwyn said:


> I shouldn't have hesitated, someone beat me to this nice pair of Tele's.  The seller is a Head-Fier, I PM'd him to see if I could save him eBay fees, too slow
> 
> https://www.ebay.com/itm/114270259204
> 
> ...


Sorry that was me! Someone sent me the link and asked if I had those boxes. But, what grabbed my attention was the included adapters - as I'm going to need those - and that made the complete package a good deal. I'm not bidding on the Valvo's!


----------



## leftside

L0rdGwyn said:


> The EL11 at least are equivalent to the EL3, with the proper adapter they should be able to be run optimally in Glenn's EL3N amp.


That was why I asked earlier. I think the main reason would be able to use the Telefunken, as I've seen plenty of Telefunken EL11, but very few Telefunken EL3N (maybe none?).


----------



## L0rdGwyn (Jul 10, 2020)

leftside said:


> Sorry that was me! Someone sent me the link and asked if I had those boxes. But, what grabbed my attention was the included adapters - as I'm going to need those - and that made the complete package a good deal. I'm not bidding on the Valvo's!



No worries! I'm sure another pair will show up, I'm gonna try for the Valvos.



leftside said:


> That was why I asked earlier. I think the main reason would be able to use the Telefunken, as I've seen plenty of Telefunken EL11, but very few Telefunken EL3N (maybe none?).



Yeah they are the same tube, just different bases.  All of the German-made I have seen are EL11 (Telefunken, Siemens, RFT, Valvo) and have the 8-pin Y8A base.  The EL3N obviously have the side contact P8A base, then there is the EL33 which has a standard octal base.  All the same tube, just different manufacturers and bases, with adapters, any of them can be subbed.  I'm surprised the EL33 haven't gotten more discussion around the tube threads since they are an octal equivalent.  Billington at one point had a pretty large stock of them for good prices.  All of the EL33 I have seen have been Mullard / Phillips.


----------



## chrisdrop

L0rdGwyn said:


> No worries! I'm sure another pair will show up, I'm gonna try for the Valvos.
> 
> Yeah they are the same tube, just different bases.  All of the German-made I have seen are EL11 (Telefunken, Siemens, RFT, Valvo) and have the 8-pin Y8A base.  The EL3N obviously have the side contact P8A base, then there is the EL33 which has a standard octal base.  All the same tube, just different manufacturers and bases, with adapters, any of them can be subbed.  I'm surprised the EL33 haven't gotten more discussion around the tube threads since they are an octal equivalent.  Billington at one point had a pretty large stock of them for good prices.  All of the EL33 I have seen have been Mullard / Phillips.


This thread sent me listening to EL3Ns and EL11s yesterday (both of mine are Phillips). One of my EL3Ns is a bit noisy. Sadly so is 1 of my EL11s. Both sets are usable but it is not silent. I did go looking yesterday for EL11s too and I am glad I didn't add to the head-fi bid-off.  IMO both of these are warmer, but quite spacious and a good compliment for crisper outputs.


----------



## UntilThen

leftside said:


> Compared my different ECC32 tubes tonight. Foil, pan and D getter. The good news is if you're looking for one of these to purely listen to, and not necessarily collect, they all sound the same - well at least in my amp. The latter D getters tend to be a little cheaper than the earlier foil or pan getters. These are absolutely some of the best drivers out there. I can't think of anything I don't like about them - and the bass with this amp is superb. Spun up tonight with 4 Tungsol 5998 and a pair of Bendix 6080.
> 
> Having listened further to the various power tubes, I do think I am hearing a slight difference with the TS 5998 over the 6AS7 and 6080 family of tubes. These are my preference right now - even more than the GEC 6AS7G - in this amp. It might be because there is extra gain with the 5998. Further listening is required.... which is fine by me
> 
> Mischa, the power section runs cooler when running the 5998's and the 5998 switch engaged. I like this, but I would have expected the amp to have run warmer with this setting/tubes. Shows what I know...



That's a staggering number of good tubes together ! I can see there are 4 x Tung Sol 5998, 2 x Mullard EL38, 2 x Bendix 6080wb, 2 x Mullard EL8 and a Mullard ECC32. What are the 3 most prominent sound characteristics you can think of to describe this combination. 

This is certainly one amp to beat them all in terms of flexibility of tube combinations.


----------



## whirlwind

L0rdGwyn said:


> No worries! I'm sure another pair will show up, I'm gonna try for the Valvos.
> 
> 
> 
> Yeah they are the same tube, just different bases.  All of the German-made I have seen are EL11 (Telefunken, Siemens, RFT, Valvo) and have the 8-pin Y8A base.  The EL3N obviously have the side contact P8A base, then there is the EL33 which has a standard octal base.  All the same tube, just different manufacturers and bases, with adapters, any of them can be subbed.  I'm surprised the EL33 haven't gotten more discussion around the tube threads since they are an octal equivalent.  Billington at one point had a pretty large stock of them for good prices.  All of the EL33 I have seen have been Mullard / Phillips.



I agree the EL33 has what IMO would be the best socket/pins as being the octal equivilent to the EL3N can't be a bad thing.


----------



## leftside

chrisdrop said:


> This thread sent me listening to EL3Ns and EL11s yesterday (both of mine are Phillips). One of my EL3Ns is a bit noisy. Sadly so is 1 of my EL11s. Both sets are usable but it is not silent. I did go looking yesterday for EL11s too and I am glad I didn't add to the head-fi bid-off.  IMO both of these are warmer, but quite spacious and a good compliment for crisper outputs.


Most are noisy in my amp as well. It's probably due to the extra gain of these tubes. They are typically used in most amps as power, not driver tubes. I think this extra warmth might simply be a little distortion (which measures terribly, but can be pleasing to the human ear). They don't sound "warm" in my amp, but the bass is definitely "different".

I'll be looking for an KT66/6L6/EL3/EL34/EL37 selector switch in my next amp if possible/reasonable. @A2029 thinks "oh no - here we go again...."


----------



## leftside

UntilThen said:


> That's a staggering number of good tubes together ! I can see there are 4 x Tung Sol 5998, 2 x Mullard EL38, 2 x Bendix 6080wb, 2 x Mullard EL8 and a Mullard ECC32. What are the 3 most prominent sound characteristics you can think of to describe this combination.
> 
> This is certainly one amp to beat them all in terms of flexibility of tube combinations.


The driver tubes are not used at the same time. The selector switch enables the circuit for the tubes selected. The TS + 2 6080 or 2 6AS7 is my favorite power combo. 6 TS is just a little "too much". Sound wise, there isn't too much difference between the various brands of power tubes due to the circuit design. I'm considering this a "good thing" (for me), as I do find sonic differences between say 76/6J5/6N7 and that's good enough. 

The amp is extremely detailed, with a defined powerful bass that I've never heard from another headphone amp. I'm completely honest when I say the 6 power tubes are overkill, and Mischa ensures me he can build a cheaper and smaller amp with the same sound signature and less power tubes. The 6 driver tube selections can be seen as great flexibility or a path to madness


----------



## UntilThen

Ah I thought the EL38 were used as power tubes but in this instance you had it in the c3g sockets as drivers. Just read your 1st page and realised that you can use 4 x 6336 as power tubes. I could use that 'warmth' in the winter of Sydney now.  

Have you run it with 4 x 6336 as power tubes?


----------



## leftside

UntilThen said:


> Ah I thought the EL38 were used as power tubes but in this instance you had it in the c3g sockets as drivers. Just read your 1st page and realised that you can use 4 x 6336 as power tubes. I could use that 'warmth' in the winter of Sydney now.
> 
> Have you run it with 4 x 6336 as power tubes?


I don't have those tubes. I bet 4 would be nice and toasty.


----------



## A2029 (Jul 18, 2020)

NEW PRODUCT:   *BLUE HALO *(Amplifier)













BLUE HALO is a dedicated amp for high impedance headphones such as the Sennheiser HD600/650/800, ZMF Verite/Verite C, Beyerdynamic, etc. (anything with 200+ ohm impedance).   It's a design that eliminates the need for 6AS7/6080/5998 power tubes for output power. It has two 6J5 sockets and a 6SN7 socket. You can plug in a pair or 6J5, a single 6SN7, or both at the same time. With the use of adapters (purchased separately), hundreds (even thousands) of other types of tubes can be used within the sockets as well (including C3G, 12AU7, 12BH7, and many many others). A 12V switch is also included at the back of the unit in order to use 12V tubes. It produces ~1 watt into 300ohms, more than enough for all high impedance headphones.

BLUE HALO is designed to have a clean, neutral, detailed and smooth sound with great bass. Tube rolling alters the tone of the amp at your preference (e.g. warmer tubes, more detailed tubes, more mids, etc.). The tubes get "supercharged" so that they can produce as much power as 6AS7/6080 power tubes, while fully determining the tone. Not having the 6AS7/6080 tubes means one less gain stage between the input and output = More clarity. The high voltage power supply uses only high quality wax/oil filled polypropylene film caps. Output capacitor are also high quality wax/oil filled polypropylene film capacitors. _This means there are zero electrolytics within the signal path - something that no other OTL tube amp has!_

BLUE HALO does not use tube rectification, it uses my own custom designed circuit using critically damped and resistivily bounded HEXFRED rectification followed by a high voltage Maida style super regulator and utilizing a wax/oil polypropylene capacitor. This is a much better alternative to tube rectification as it leads to better overall tonal quality, better bass and cleaner overall tone. This also gives deeper blacks and bigger soundstage than tube rectification. It also uses regulated DC on the heaters for a silent black background and zero hum.

BLUE HALO has a base build that includes Neutrik RCA & XLR inputs, Neutrik TRS and 4pin XLR outputs, CNC Engraving, QQQ sockets, Alps Blue velvet pot, and high quality copper internal wiring.

Potential upgrade options include: Lundahl power transformer, Stepped Attenuator (e.g. Acoustic Dimension, Goldpoint, Khozmo, etc.), Kiwame power resistor upgrade, Vishay/Dale RN55/RN60 signal resistor upgrade, Supercharger capacitor upgrades, vibration isolation feet, tube socket upgrades, and RCA/XLR connector upgrades. VU Meters are also possible.

More Photos of BLUE HALO here: https://photos.app.goo.gl/yhVnwuC9Tp25vXdD8

_If interested in a custom build, please contact for more details, pricing and build time._


----------



## L0rdGwyn

Looks fantastic, awesome work @A2029 looking forward to hearing impressions, maybe even laying ears on one some day!


----------



## whirlwind

Looks nice!


----------



## LoryWiv

A2029 said:


> ...*The tubes get "supercharged" so that they can produce as much power as 6AS7/6080 power tubes*, while fully determining the tone. Not having the 6AS7/6080 tubes means one less gain stage between the input and output = More clarity. The high voltage power supply uses only high quality wax/oil filled polypropylene film caps. Output capacitor are also high quality wax/oil filled polypropylene film capacitors. _This means there are zero electrolytics within the signal path - something that no other OTL tube amp has!_


Really intriguing, thanks @A2029! Wondering if this design / tube implementation impacts tube lifespan or other operating characteristics.


----------



## A2029 (Aug 15, 2020)

New Product: *PURE POWER C2029   *(Power Conditioner + Surge Protection)



 




 



The PURE POWER C2029 is built for those looking to clean up noise from their house power lines. It has high, medium and low current outlets so that you can plug a whole audio system into the conditioner. The high current line features zero current limiting for heavy current devices (up to 15 Amps) while still offering mild line filtering. The low current outlet offers a high amount of filtering for low current devices (up to 4 Amps), and is best suited to digital devices most sensitive to line noise. Low current devices with switching power supplies can also be plugged into the low current outlet for the most decoupling of their RFI/EMI noise from the rest of the audio system. Medium current outlet offers a middle ground between filtering and un-impeded current flow (up to 8 Amps), and can sound best with medium current analog devices such as headphone amplifiers. All outlets are decoupled from each other and RC damped to reduce power line ringing during transformer pulses. All lines are triple surge protected against massive surges (up to 40 kA!!) by combinations of UltraMOVs and GDTs, all without affecting the delivery of filtered AC.

Base build uses Leviton 5262-GY outlets with nice brass backstraps and tremendous gripping force. Cheaper outlets use steel backstraps, meaning that ground currents have to run through high resistance magnetic steel. Not here I say! Further outlet upgrades are available on request. _Also possible to put analog current and voltage panel meters on the front to get an indication of line voltage and current._

Here we can see the BLUE HALO amp stacked on top of the C2029 conditioner (same footprint):



 



_The Pure Power C2029 is available as a stand alone build, or paired with the Blue Halo amplifier. If interested in a build, please contact for more details, pricing and build time. _


----------



## A2029 (Jul 19, 2020)

LoryWiv said:


> Really intriguing, thanks @A2029! Wondering if this design / tube implementation impacts tube lifespan or other operating characteristics.



It actually runs the tubes pretty conservatively, about 1.25W dissipation on each plate of a 6SN7 or 6J5 - so not even 50% of max dissipation per plate. Tubes should have nice long life in the Blue Halo. Runs the tubes with a flat loadline as well for most linear operation of the tubes.


----------



## leftside

Love it! You must be very happy with how it turned out. I'm sure the new owner will be as well! It looks so clean and very professional.

One place up the ladder for those of us on the waitlist


----------



## A2029

leftside said:


> Love it! You must be very happy with how it turned out. I'm sure the new owner will be as well! It looks so clean and very professional.
> 
> One place up the ladder for those of us on the waitlist



Turned out fantastic! During burn in I sat down for a 10 min listen between some chores that I had to do... Ended up getting out of the chair 3 hours later, chores be damned!


----------



## A2029

NEW PRODUCTS: *CUSTOMIZED POWER CABLES*




 






Customized power cables built to your spec, with choices of wire, cable coverings, and connector ends. Featured here is a gorgeous cable with Uptown gold covering and rhodium plated carbon fibre plugs. Lots of options available. Contact for more details.


----------



## A2029

NEW PRODUCTS: *CUSTOMIZED ANALOG AUDIO CABLES (RCA & XLR)*



 





 

 



Just as with the power cables I offer, analog audio cables are built to your spec, with choices of wire, cable coverings, and connector ends. Lots of options available. Contact for more details.


----------



## Celty

A2029 said:


> NEW PRODUCT:   *BLUE HALO *(Amplifier)
> 
> 
> 
> ...


That appears to be an intriguing  design, just about the sort of amp I have been interested in finding for my Auteur! I look forward to learning more about it. I have been on the waiting list for a Glenn, but that might require a lengthy wait still from what I am hearing. My other considerations at this point have been the ZMF Pendant and the DNA Starlett. Looks like a Blue Halo should be in the running now!  Great name BTW


----------



## A2029 (Jul 19, 2020)

Celty said:


> That appears to be an intriguing  design, just about the sort of amp I have been interested in finding for my Auteur! I look forward to learning more about it. I have been on the waiting list for a Glenn, but that might require a lengthy wait still from what I am hearing. My other considerations at this point have been the ZMF Pendant and the DNA Starlett. Looks like a Blue Halo should be in the running now!  Great name BTW



Thanks Celty, but I can't take credit for the name - Mad props goes out to @magicman2020 for suggesting the name of the Blue Halo amp and C2029 power conditioner, and for his ideas on engraving locations on the faceplates. I really enjoy collabs with great members of this community!


My company name, 1101 Audio, is conceived from IC1101 - the largest supergiant elliptical galaxy at the center of the Abell 2029 (A2029) galaxy cluster. The name Blue Halo has relation to several astronomical phenomena including the galactic halo; Wikipedia describes a galactic halo as an "extended, roughly spherical component of a galaxy which extends beyond the main, visible component".


----------



## Jaeger18

Celty said:


> That appears to be an intriguing  design, just about the sort of amp I have been interested in finding for my Auteur! I look forward to learning more about it. I have been on the waiting list for a Glenn, but that might require a lengthy wait still from what I am hearing. My other considerations at this point have been the ZMF Pendant and the DNA Starlett. Looks like a Blue Halo should be in the running now!  Great name BTW




exactly the same options that i had in mind.. dna stratus, GOTL, pendant... but finally decided to buy BLUE HALO..


----------



## Celty

Jaeger18 said:


> exactly the same options that i had in mind.. dna stratus, GOTL, pendant... but finally decided to buy BLUE HALO..


Cool! I'll be excited to read your experience with it.


----------



## chrisdrop

A2029 said:


> NEW PRODUCT:   *BLUE HALO *(Amplifier)
> 
> 
> 
> ...


Congrats Mischa & to the new soon-to-be-even-happier owner  
It looks lovely and I am betting it sounds lovely too!


----------



## Jaeger18 (Jul 19, 2020)

Celty said:


> Cool! I'll be excited to read your experience with it.



im not an expert by any means... with that said.. i do believe listening music to any audio gear comes down to your personal preference.  For me personaly,the main reason why i bought BLUE HALO is based on Mischa's description... and i cant wait to share my thoughts of BLUE HALO in the future...


----------



## Xcalibur255

Congrats Mischa on the launch.  The amp looks lovely.

So Blue Halo is OTL?  There must be some neat tricks to get the output impedance down to something reasonable with that output stage.

If I had a crystal ball I would also guess that a version of this with OPTs to better suit low-Z headphones will land sooner or later too.


----------



## A2029 (Jul 20, 2020)

Xcalibur255 said:


> Congrats Mischa on the launch.  The amp looks lovely.
> 
> So Blue Halo is OTL?  There must be some neat tricks to get the output impedance down to something reasonable with that output stage.



Thank you fine sir!  That's correct, OTL. Output impedance is in the realm of 20-30 ohm. Zero negative feedback design, pure class A. Supercharged driver tubes that determine all of the harmonics and tone of the output. The driver tube is the only gain stage and to top it off the signal passes through very few components. PSRR across the audioband of greater than -170dB gives a dead quiet background when using good tubes (non-noisy tubes).



Xcalibur255 said:


> If I had a crystal ball I would also guess that a version of this with OPTs to better suit low-Z headphones will land sooner or later too.



We'll see what comes down the road; between building amps and finishing off a PhD I'm pretty swamped at the moment


----------



## maxpudding

Congratulations Mischa, the design of the amp is excellent, it looks lovely too. It’s always exciting to see more custom products available in the market. Cheers!


----------



## Jaeger18

im having a hard time finding a good cable for my headphone that will complement my future BLUE HALO and my ZMF VC.. anyone has any recommendation? 
i am on the verge of getting silver or copper wire to upgrade from my stock cable, initially i was thinking of buying 2k copper / Verite 4 strand pure silver 
(i bet zmf offers a very good silver and copper wires) but since it cost a fortune, i changed my mind and decide to find a 3rd party cable that sounds as good 
or better than what ZMF offers but with a friendlier price tag ...  Which leads me to my last question, what type of material is best for cables? do you think OCC 
is good? im planning to go straight to end game . Any suggestions, or better sharing links is favorable thanks..


----------



## chrisdrop

Jaeger18 said:


> im having a hard time finding a good cable for my headphone that will complement my future BLUE HALO and my ZMF VC.. anyone has any recommendation?
> i am on the verge of getting silver or copper wire to upgrade from my stock cable, initially i was thinking of buying 2k copper / Verite 4 strand pure silver
> (i bet zmf offers a very good silver and copper wires) but since it cost a fortune, i changed my mind and decide to find a 3rd party cable that sounds as good
> or better than what ZMF offers but with a friendlier price tag ...  Which leads me to my last question, what type of material is best for cables? do you think OCC
> is good? im planning to go straight to end game . Any suggestions, or better sharing links is favorable thanks..


My 2p; Make it. Get Neotech UPOCC silver, order some Furu or other connectors. check the DIY forums. Still expensive, but you save. If you don't want silver, get Neotech UPOCC copper.


----------



## Jaeger18 (Aug 9, 2020)

chrisdrop said:


> My 2p; Make it. Get Neotech UPOCC silver, order some Furu or other connectors. check the DIY forums. Still expensive, but you save. If you don't want silver, get Neotech UPOCC copper.



As always you are very helpful Chris. Sadly i tend to mess things up on DIY stuff, i know my limits and it is better for me to stay away. Instead.. what do you think about these two pre made wires:

https://www.toxic-cables.co.uk/product/black-widow-22-occ-copper-litz-headphone-cable/

https://www.toxic-cables.co.uk/product/hydra-22-22awg-litz-occ-pure-silver-cable/


----------



## chrisdrop

Jaeger18 said:


> As always you are very helpful Chris. Sadly i tend to mess things up on DIY stuff, i know my limits and it is better for me to stay away. Instead.. what do you think about these two pre made wires:
> 
> https://www.toxic-cables.co.uk/product/black-widow-22-occ-copper-litz-headphone-cable/
> 
> https://www.toxic-cables.co.uk/product/hydra-22-22awg-litz-occ-pure-silver-cable/


The only cable I have really used is (by recommendation) by Neotech. This may fit; https://www.cosmic-cables.co.uk/product-page/neptune-sleeved-pure-silver. If not, the about page says you can just message them and ask for what you want. I think I got my parts and cable from them and that is pretty close to my VC headphone cable. All that said, I am sure there are other good cables out there. I was guided by another DIY'er (who often led me somewhere good) and landed here.


----------



## Jaeger18

chrisdrop said:


> The only cable I have really used is (by recommendation) by Neotech. This may fit; https://www.cosmic-cables.co.uk/product-page/neptune-sleeved-pure-silver. If not, the about page says you can just message them and ask for what you want. I think I got my parts and cable from them and that is pretty close to my VC headphone cable. All that said, I am sure there are other good cables out there. I was guided by another DIY'er (who often led me somewhere good) and landed here.



Nice... thanks alot for the link...


----------



## Marutks

Jaeger18 said:


> https://www.toxic-cables.co.uk/product/black-widow-22-occ-copper-litz-headphone-cable/



I use Black Widow cable with my ZMF VC !  It is very good.   It sounds like my Norne S3 silver cable. 
I couldn't hear any difference.   Copper and silver cables sound the same to me.


----------



## Celty

Jaeger18 said:


> im having a hard time finding a good cable for my headphone that will complement my future BLUE HALO and my ZMF VC.. anyone has any recommendation?
> i am on the verge of getting silver or copper wire to upgrade from my stock cable, initially i was thinking of buying 2k copper / Verite 4 strand pure silver
> (i bet zmf offers a very good silver and copper wires) but since it cost a fortune, i changed my mind and decide to find a 3rd party cable that sounds as good
> or better than what ZMF offers but with a friendlier price tag ...  Which leads me to my last question, what type of material is best for cables? do you think OCC
> is good? im planning to go straight to end game . Any suggestions, or better sharing links is favorable thanks..


When it comes to headphones, Dac's, and amps, I do think there are big differences in sound quality (the most with headphones, then amps, and to a degree, dacs).

With cables I think that is more snake oil and marketing past the point of a well made cable constructed of quality materials. Have you ever seen a legitimate blind headphone cable test in which the subjects could make accurate identifications of which cables they were listening to? Nuff said.

Personally I have liked Periapt and Hart Audio cables.
https://periaptcables.com/





https://hartaudiocables.com/



I do like the easily switchable interconnects for the Hart cables, one cable connects to just about anything (I went for the full interconnect kit with matching sleeveing).


----------



## maxpudding

Jaeger18 said:


> As always you are very helpful Chris. Sadly i tend to mess things up on DIY stuff, i know my limits and it is better for me to stay away. Instead.. what do you think about these two pre made wires:
> 
> https://www.toxic-cables.co.uk/product/black-widow-22-occ-copper-litz-headphone-cable/
> 
> https://www.toxic-cables.co.uk/product/hydra-22-22awg-litz-occ-pure-silver-cable/



I read good reviews from the people who own toxic cables, but YMMV. Either that, or I am going down the diy path like what CD mentioned. Still thinking about it.


----------



## Jaeger18

Marutks said:


> I use Black Widow cable with my ZMF VC !  It is very good.   It sounds like my Norne S3 silver cable.
> I couldn't hear any difference.   Copper and silver cables sound the same to me.



Performance aside, Black widow + Translucent Black color combination sure knocked it out of the park on its aesthetic...


----------



## Jaeger18 (Aug 10, 2020)

Celty said:


> When it comes to headphones, Dac's, and amps, I do think there are big differences in sound quality (the most with headphones, then amps, and to a degree, dacs).
> 
> With cables I think that is more snake oil and marketing past the point of a well made cable constructed of quality materials. Have you ever seen a legitimate blind headphone cable test in which the subjects could make accurate identifications of which cables they were listening to? Nuff said.
> 
> ...




nice cable collection uve got there, i see where you are going with your cable, color wise it fits so well with your Auteur....
First of this is my setup, mind that IHA-1 will most likely to be replaced by my upcoming BLUE HALO:





I know i know.. i have to work on taking a better picture...
All that aside, the cable that i use for my HD800s is BESPOKE ARES II. Ive compared it to my HD800s cable (not directly but of the
same tracks), dont quote me on this but i tend to enjoy more with my copper cable than i did with the stock cable... it might be the
aesthetic and the 'feel' of the cable or because the sound pierce less with the copper cable ever so slightly, that makes me enjoy the
music more as a whole if that even makes any sense.I hvnt done a blind test before, you might be right, i might be completely wrong
on this (i hope im wrong because im not ready to spend more money on cables for my zmf VC...)


----------



## Jaeger18

maxpudding said:


> I read good reviews from the people who own toxic cables, but YMMV. Either that, or I am going down the diy path like what CD mentioned. Still thinking about it.



Damn i wish i could be good at DIY stuff... why dont u make me one lol...


----------



## chrisdrop

maxpudding said:


> I read good reviews from the people who own toxic cables, but YMMV. Either that, or I am going down the diy path like what CD mentioned. Still thinking about it.


*I am a non-handy person. *If I could do it, _anyone_ can do it. Really. 1) Get soldering iron & multimeter. Get some cheap wire and bits to solder together for practice. 2) Build a cheaper HP cable - Neotech UP OCC Copper w/ inexpensive connectors. Get a few extra mini-XLR plugs, they are tiny and I melted a few by sucking at it. It worked eventually, however. Then make some RCA cables, same - inexpensive 1st. Then make a more expensive set for your main HPs. I emphasise - I am absolutely not a handy person. It is a humbling experience to be laid low by a crappy solder joint! The reward of making a functional physical thing is nice, however. Even easier, start with a power cable, no soldering! Just get wire, connectors, screw it all together! 

Alternatively - I bet @A2029 can make just about anything you ask in this space.


----------



## maxpudding

chrisdrop said:


> *I am a non-handy person. *If I could do it, _anyone_ can do it. Really. 1) Get soldering iron & multimeter. Get some cheap wire and bits to solder together for practice. 2) Build a cheaper HP cable - Neotech UP OCC Copper w/ inexpensive connectors. Get a few extra mini-XLR plugs, they are tiny and I melted a few by sucking at it. It worked eventually, however. Then make some RCA cables, same - inexpensive 1st. Then make a more expensive set for your main HPs. I emphasise - I am absolutely not a handy person. It is a humbling experience to be laid low by a crappy solder joint! The reward of making a functional physical thing is nice, however. Even easier, start with a power cable, no soldering! Just get wire, connectors, screw it all together!
> 
> Alternatively - I bet @A2029 can make just about anything you ask in this space.



If you could build a crack, then you are heading the right way already. Everyone has to start somewhere


----------



## maxpudding

Jaeger18 said:


> Damn i wish i could be good at DIY stuff... why dont u make me one lol...



I have just started doing audio diy stuffs, you’ll be better off with established diy’ers


----------



## Celty

Jaeger18 said:


> nice cable collection uve got there, i see where you are going with your cable, color wise it fits so well with your Auteur....
> First of this is my setup, mind that IHA-1 will most likely to be replaced by my upcoming BLUE HALO:
> 
> 
> ...


Ha Ha, thanks, yes that is exactly why I chose that particular sleeve color (that is another thing I like about Hart, you can choose from a huge array of custom colors and patterns for a nominal fee). I look forward to reading your impressions of the Blue Halo, what is your expected time frame for delivery?


----------



## Jaeger18 (Aug 12, 2020)

Celty said:


> Ha Ha, thanks, yes that is exactly why I chose that particular sleeve color (that is another thing I like about Hart, you can choose from a huge array of custom colors and patterns for a nominal fee). I look forward to reading your impressions of the Blue Halo, what is your expected time frame for delivery?




i've been informed by Mischa that a lot of the parts that he ordered to build my amp are currently
on back order due to the pandemic, so the amp will take a little longer than originally anticipated.
But I'm perfectly fine... I believe someone will get his new Blue Halo soon thou, So i guess we will
have his impression of the Blue Halo near future. (You should be more excited to look forward to reading
his impression of the Blue Halo rather than my take on the Blue Halo... haha... ) i might be wrong but
i guess im next in line.

Anyways... Back to cables, do you guys think 8 cores vs 4 cores OCC silver makes a difference regarding
sonic performance?


----------



## ScornDefeat

I took receipt of the Pure Power C2029 Power Conditioner this week. Immediate reaction; feels and looks like an exceptionally well-built piece!

First thing to note is the service from 1101 Audio. Mischa is the best client service I've yet to experience in this industry; incredibly knowledgeable, wonderful communication, highly flexible. Not a single flaw to the service or entire process. Answered every question in detail. If I could get every component for any past, present or future head-fi gear through Mischa, I would.

I finally got a chance properly give the new set-up a spin. This chain with the C2029 is Ampsandsound Pendant in the H bank, DIY HTPC Roon Core/Streamer in the M bank, and Chord Qutest DAC in the L bank.

Very happy with the sound so far! My perception was that the tube amp had a lower noise floor than before and that the macro-dynamics popped out more. Subtle, possibly psychoacoustic, but I felt like I couldn't recall the Pendant being this quiet and slamming this hard until now. Obviously, I'm quite satisfied with the improvement. 

Ultimately, the aesthetics of the C2029 in my set-up is such a plus. It just looks badass for a power con! I had mine customized with symmetrical ammeter, voltmeter and LED-ring power push button in the center. I'll let this in-the-dark tube glow/power con LED photo do all the talking. Perfect synergy!


----------



## magicman2020

Jaeger18 said:


> i've been informed by Mischa that a lot of the parts that he ordered to build my amp are currently
> on back order due to the pandemic, so the amp will take a little longer than originally anticipated.
> But I'm perfectly fine... I believe someone will get his new Blue Halo soon thou, So i guess we will
> have his impression of the Blue Halo near future. (You should be more excited to look forward to reading
> ...


Hold on. It might be later rather then sooner. 
I UNFORTUNATELY don't have a dac to supply my soon to be shipped Blue Halo Amp yet, as my dac is on back order. Rest assured as soon as it arrives I'll be passing along my impressions along. 
Congrats on your upcoming Blue Halo.


----------



## Jaeger18

magicman2020 said:


> Hold on. It might be later rather then sooner.
> I UNFORTUNATELY don't have a dac to supply my soon to be shipped Blue Halo Amp yet, as my dac is on back order. Rest assured as soon as it arrives I'll be passing along my impressions along.
> Congrats on your upcoming Blue Halo.




i bet its gonna be great....cant wait to get mine


----------



## magicman2020

Agreed, I believe It will be absolutely sublime


----------



## canfabulous

magicman2020 said:


> Hold on. It might be later rather then sooner.
> I UNFORTUNATELY don't have a dac to supply my soon to be shipped Blue Halo Amp yet, as my dac is on back order. Rest assured as soon as it arrives I'll be passing along my impressions along.
> Congrats on your upcoming Blue Halo.



Ah man... can't believe you are still waiting for the Rockna!


----------



## magicman2020

canfabulous said:


> Ah man... can't believe you are still waiting for the Rockna!


Me too. My amp, power Conditioner, and almost every cable are done. There's a cable part Mischa is waiting on. 
Other then that, I'm pleased to report the VC's are nicely burned in.


----------



## UntilThen

ScornDefeat said:


> First thing to note is the service from 1101 Audio. Mischa is the best client service I've yet to experience in this industry



Amazing testimony.  

Now to wait see what Leftside gets for his EL34 amp. I might get the itch to use my EL11 / EL12 spez tubes.


----------



## chrisdrop

Look what arrived yesterday...

Certainly not the best photos, but they'll do for now. I managed to get only a short while last night, and I'll have a few hours to listen now. 

!Tx Mischa!


----------



## Jaeger18

OMG THAT LOOKS STUNNING


----------



## mordy

chrisdrop said:


> Look what arrived yesterday...
> 
> Certainly not the best photos, but they'll do for now. I managed to get only a short while last night, and I'll have a few hours to listen now.
> 
> !Tx Mischa!


Congratulatons! Can't wait to hear your listening impressions, especially a comparison with the GOTL.....


----------



## ScornDefeat

chrisdrop said:


> Look what arrived yesterday...
> 
> Certainly not the best photos, but they'll do for now. I managed to get only a short while last night, and I'll have a few hours to listen now.
> 
> !Tx Mischa!



This would stack exceptionally well with the C2029 Pure Power Conditioner 😏


----------



## chrisdrop

ScornDefeat said:


> This would stack exceptionally well with the C2029 Pure Power Conditioner 😏


I'm sure it would. That said, I have a reasonably comprehensive power setup in the cupboard beneath


----------



## Zachik

chrisdrop said:


> I managed to get only a short while last night, and I'll have a few hours to listen now.


Cannot wait for your impressions, especially in comparison to your GOTL (with the floor-noise-reduction-dongle...)


----------



## Xcalibur255

I think you'll be the first one to offer listening impressions on a Blue Halo.  Looking forward to reading.


----------



## UntilThen

chrisdrop said:


> Look what arrived yesterday...



Very nice. I like clean and simple design. It looks smart. So much so I have to re-read the product announcement again - https://www.head-fi.org/threads/1101-audio-custom-crafted-headphone-amps.919425/post-15747309


----------



## canfabulous

chrisdrop said:


> Look what arrived yesterday...
> 
> Certainly not the best photos, but they'll do for now. I managed to get only a short while last night, and I'll have a few hours to listen now.
> 
> !Tx Mischa!



ooh.  Congrats!  Can’t wait to hear what you think of it!


----------



## chrisdrop (Sep 17, 2020)

I've only had 4-5 hours so far. I'm back at the office nowadays so evenings it is. I swapped tubes for the 1st time ~30 mins ago; moving from 2x GEC 6J5G to 2x RCA 6N7G. It is a cool feature; 6J5 and 6N7 in the same socket. I believe @leftside's monster amp has (inspired?) this feature. I wanted to see the effect of rolling in the amp. How much does it change the sound? ... it does 

It is too soon to start offering any meaningful sound commentary. For now, I'll say it is certainly a pleasing listen right out of the box. It also aesthetically presents very well. It is clean professional, very polished and good looking. Comparing vs GOTL, will take some real time listening, alternating, developing non-capricious opinions, etc. To be clear; I love my GOTL. I am super thankful to have it. I think I will _also love_ the BH. Maybe we're on a killer 1st date right now? I feel pretty spoilt! _Ampolygamy_?

Others have also said that Mischa is great to work with. Confirmed. We've gone _slightly_ different than the "base spec" of the BH in one material way. Here are the short options/ details:

2x octal sockets that take 6J5 (and related) tubes. These also take 6N7 tubes, as mentioned above. I'm a big fan of these tubes and I've got a solid collection of 'em.
6v 12v switch for the octal sockets
_[this is the difference]_ 2x loctal-8 C3G sockets. (The "base spec" has 1x 6SN7 socket.) Clearly one can run C3Gs. These sockets were wired to be compatible with the various C3G related adapters/tubes I have already. Mischa spoke to @Deyan to coordinate. In this way, I can leverage tubes I have in the collection. The dialogue with Mischa on this variation was great and I like where we landed.
You can run _either or both_ (pairs of) tubes in the the Octal / Loctal-8 sockets.
Other options; Lundahl transformer, Goldpoint stepped-attenuator, Jupiter Copper caps,  Kiwame power resistors, Vishay/Dale RN55/60 signal resistors
_The rest of the specs you can see in the product announcement that UT was kind enough to post. _
For now, happy listening. I'm really thankful to have amps from great builders like we have here in the head-fi community. Thanks again Mischa.

-Chris-

N.B. here are my Blue Halo notes for any interested readers. (You'll see I was inspired by @Zachik's GOTL compatibility sheet).






This post brought to you by Blue Halo and Molife...


----------



## mordy

chrisdrop said:


> I've only had 4-5 hours so far. I'm back at the office nowadays so evenings it is. I swapped tubes for the 1st time ~30 mins ago; moving from 2x GEC 6J5G to 2x RCA 6N7G. It is a cool feature; 6J5 and 6N7 in the same socket. I believe @leftside's monster amp has (inspired?) this feature. I wanted to see the effect of rolling in the amp. How much does it change the sound? ... it does
> 
> It is too soon to start offering any meaningful sound commentary. For now, I'll say it is certainly a pleasing listen right out of the box. It also aesthetically presents very well. It is clean professional, very polished and good looking. Comparing vs GOTL, will take some real time listening, alternating, developing non-capricious opinions, etc. To be clear; I love my GOTL. I am super thankful to have it. I think I will _also love_ the BH. Maybe we're on a killer 1st date right now? I feel pretty spoilt! _Ampolygamy_?
> 
> ...



If I understand correctly no option to use 6SN7 family tubes?
To use the 6J7 you will need the EL32 adapter to C3g.


----------



## chrisdrop

mordy said:


> If I understand correctly no option to use 6SN7 family tubes?
> To use the 6J7 you will need the EL32 adapter to C3g.


Yes. I don't have a massive 6SN7 collection, more in the 6J5 family. I do have/ really like 6J7s, and I'll use those via the C3G sockets (like on the GOTL).


----------



## Zachik

@chrisdrop - how is the noise-floor like? Totally non-audible?
I am very curious how this single-stage amp compares with 2-stage amps like GOTL. If memory serves, Mischa wrote at some point that less gain stages results in much quieter (less noise) amps...


----------



## chrisdrop (Sep 17, 2020)

Zachik said:


> @chrisdrop - how is the noise-floor like? Totally non-audible?
> I am very curious how this single-stage amp compares with 2-stage amps like GOTL. If memory serves, Mischa wrote at some point that less gain stages results in much quieter (less noise) amps...


Yes. This amp is just quiet.  I've managed, with a load of tricks and effort which you are familiar with, to get the GOTL to be mostly quiet. This amp is quiet with no effort. I think this is a core design feature that Mischa feels very strongly about. If I listen hard in a dead quiet room, with closed back headphones only, I can probably hear something quite faint. I think with open backs I don't see how I'd hear anything audible above ambient noise. This was a was a goal of mine, I am very happy to say that it was met.


----------



## UntilThen

Thanks for sharing the specs Chris. Blue Halo starts to sound more appealing when you mention 6N7 tubes because I still have a bunch of rare and mint Fivre, Visseaux 6N7Gs. Now if I could have EL11 sockets there because I have a bunch of brand new EL11s. I'm thinking out loud.  

Good to hear that the Blue Halo is quiet. Great specs by the way.


----------



## leftside

UntilThen said:


> Thanks for sharing the specs Chris. Blue Halo starts to sound more appealing when you mention 6N7 tubes because I still have a bunch of rare and mint Fivre, Visseaux 6N7Gs. Now if I could have EL11 sockets there because I have a bunch of brand new EL11s. I'm thinking out loud.
> 
> Good to hear that the Blue Halo is quiet. Great specs by the way.


Maybe EL11 as power and 6J5/6N7G as drivers? I'll have EL34/6L6 sockets in the next amp for power, but I might well have an EL11 option on the power tube selector switch.

In my amp (which also uses a CCS design) I don't hear huge differences between the various 6J5's, but I definitely notice a difference if I go from a 6J5 to a 76 to a 6C5 to a 6N7, etc.


----------



## mordy

leftside said:


> Maybe EL11 as power and 6J5/6N7G as drivers? I'll have EL34/6L6 sockets in the next amp for power, but I might well have an EL11 option on the power tube selector switch.
> 
> In my amp (which also uses a CCS design) I don't hear huge differences between the various 6J5's, but I definitely notice a difference if I go from a 6J5 to a 76 to a 6C5 to a 6N7, etc.


Am I right in that the Blue Halo does not have power tubes?


----------



## leftside

mordy said:


> Am I right in that the Blue Halo does not have power tubes?


Yep: https://www.head-fi.org/threads/110...d-headphone-amps.919425/page-10#post-15747309


----------



## UntilThen

leftside said:


> Maybe EL11 as power and 6J5/6N7G as drivers? I'll have EL34/6L6 sockets in the next amp for power, but I might well have an EL11 option on the power tube selector switch.
> 
> In my amp (which also uses a CCS design) I don't hear huge differences between the various 6J5's, but I definitely notice a difference if I go from a 6J5 to a 76 to a 6C5 to a 6N7, etc.



I'm thinking more of using EL34 / EL12 spez as power tubes. Choice to use either as a pair or quad. Choice to use either EL11 / 6N7 / 12SL7gt as drivers because I have a mint pair of Tung Sol 12SL7gt bgrp.  

This is deviating from the simple clean looks of the Blue Halo though.


----------



## Zachik

chrisdrop said:


> Yes. This amp is just quiet.  I've managed, with a load of tricks and effort which you are familiar with, to get the GOTL to be mostly quiet. This amp is quiet with no effort. I think this is a core design feature that Mischa feels very strongly about. If I listen hard in a dead quiet room, with closed back headphones only, I can probably hear something quite faint. I think with open backs I don't see how I'd hear anything audible above ambient noise. This was a was a goal of mine, I am very happy to say that it was met.


Once you spend more time with your new toy - try to compare to the GOTL in term of sound signature difference between the single stage BH and the 2-stage (driver + output) GOTL.
I understand the BH is very quiet, but I am curious whether the sound signature is much different between them (using similar tubes, say the 6J5s).
On a similar note, my 6EL3N amp has a switch to toggle between 1- or 2-stage operation (bypassing the output tubes in the 1-stage mode). I wonder if the GOTL (with the proper modification) can also become 1-stage amp (bypassing either the drivers or the output tubes)...


----------



## whirlwind

leftside said:


> Maybe EL11 as power and 6J5/6N7G as drivers? I'll have EL34/6L6 sockets in the next amp for power, but I might well have an EL11 option on the power tube selector switch.
> 
> In my amp (which also uses a CCS design) I don't hear huge differences between the various 6J5's, but I definitely notice a difference if I go from a 6J5 to a 76 to a 6C5 to a 6N7, etc.



I agree about the CCS load as I had it installed in my GOTL.....all 6J5 tubes sound killer, separation is fantastic even when using the cheapest of 6J5 tubes...I am a believer


----------



## Xcalibur255

whirlwind said:


> I agree about the CCS load as I had it installed in my GOTL.....all 6J5 tubes sound killer, separation is fantastic even when using the cheapest of 6J5 tubes...I am a believer


I have heard from a few people now that using a CCS tends to minimize variation from tube rolling somewhat, akin to pulling the extremes in I guess you could say.  I think if the technical aspects become more grouped together but the tone flavor variations you hear from brand to brand remain that would be absolutely ideal in my mind.


----------



## chrisdrop

Xcalibur255 said:


> I have heard from a few people now that using a CCS tends to minimize variation from tube rolling somewhat, akin to pulling the extremes in I guess you could say.  I think if the technical aspects become more grouped together but the tone flavor variations you hear from brand to brand remain that would be absolutely ideal in my mind.


Is there a technical rationale for this that someone can explain to us, laypersons?


----------



## A2029

chrisdrop said:


> Is there a technical rationale for this that someone can explain to us, laypersons?



When using a CCS, it makes the loadline almost completely horizontal across the tube curves. This makes the tubes act in their most "linear" range as possible, and reduces their distortion produced as they swing through this linear range as they do their voltage amplification. Different tubes of the same type have slightly different voltage curves. Some are more or less linear than others. The CCS minimizes these differences because the loadline is through the most linear area of these curves. Using a CCS also allows for the elimination of the cathode capacitor, so you can get rid of electrolytic cap distortion and non-linear effects of the cap on tube amplification.

Here is a graphical representation of what a CCS does to the loadline. First is a loadline on a 6J5 tube loaded with a ~25K plate load resistor (not a CCS). You'll notice that the loadline is sloped downwards:







There is a lot of non-linear distortion introduced when the voltage swing along the loadline goes through the curved portions of the voltage curves where the curves are more squashed together, especially if the tube swings through this region down here:






Instead of a plate resistor, a CCS presents a huge AC impedance, equivalent to a 2-10 million ohm plate resistor. This makes the loadline almost completely horizontal so that it isn't swinging through the curves where the lines are more squashed together:





Note how if you look in this area here, the blue lines are about the same distance on either side of the red dot (the red dot is the operating point in this example):


----------



## mordy

A2029 said:


> When using a CCS, it makes the loadline almost completely horizontal across the tube curves. This makes the tubes act in their most "linear" range as possible, and reduces their distortion produced as they swing through this linear range as they do their voltage amplification. Different tubes of the same type have slightly different voltage curves. Some are more or less linear than others. The CCS minimizes these differences because the loadline is through the most linear area of these curves. Using a CCS also allows for the elimination of the cathode capacitor, so you can get rid of electrolytic cap distortion and non-linear effects of the cap on tube amplification.
> 
> Here is a graphical representation of what a CCS does to the loadline. First is a loadline on a 6J5 tube loaded with a ~25K plate load resistor (not a CCS). You'll notice that the loadline is sloped downwards:
> 
> ...


Thanks for the clarification. How does the sound change using the CCS?
Does it also mean that when using a CCS the tube itself does not matter that much, as long as it has the same designation/specifications? 
Do the applications for CCS involve both input and output tubes?


----------



## A2029 (Sep 19, 2020)

mordy said:


> Thanks for the clarification. How does the sound change using the CCS?



Using generalities, a CCS gives a more clear/defined/transparent and "hifi-ish" tone, so to speak. It can lift veils that let you hear more of the nuances of the recording (micro/macrodynamics) and of the upstream gear. It comes at the cost of being more transparent and having less distortion/warmth, so there is the potential of hearing more of the "junk" in some poorly recorded tracks, and potentially hearing more nuances of the DAC. If your ears are sensitive to delta-sigma oversampling DACs (especially certain poor implementation of the older Sabre chips), then having a delta-sigma DAC + highly transparent amp with CCSs + highly transparent headphone can give so much transparency of the DAC that it could be overwhelming/annoying.



mordy said:


> Does it also mean that when using a CCS the tube itself does not matter that much, as long as it has the same designation/specifications?



Tube still matters, but maybe slightly less so. Tubes with the same designation will generally sound more similar to each other as their tube curves will be more similar to each other by design, but there will be slight variances in certain parameters based on the manufacturer making the tube and the quality/properties of their machinery. Tubes also vary in the quality and composition of the metals used. Different families of tubes will most often sound much more different as @leftside was mentioning previously.



mordy said:


> Do the applications for CCS involve both input and output tubes?



Depends on the design of the amp. Usually constant current sources (CCSs) are used for preamp/driver tubes. More rare to see a constant current source on the output tube. Sometimes see constant current sinks (also shortened to CCSs confusingly) on the output tubes. @leftside's amp for instance has CCSources on the input tubes and CCSinks on the output tubes.


----------



## chrisdrop

A2029 said:


> Using generalities, a CCS gives a more clear/defined/transparent and "hifi-ish" tone, so to speak. It can lift veils that let you hear more of the nuances of the recording (micro/macrodynamics) and of the upstream gear. It comes at the cost of being more transparent and having less distortion/warmth, so there is the potential of hearing more of the "junk" in some poorly recorded tracks, and potentially hearing more nuances of the DAC. If your ears are sensitive to delta-sigma oversampling DACs (especially certain poor implementation of the older Sabre chips), then having a delta-sigma DAC + highly transparent amp with CCSs + highly transparent headphone can give so much transparency of the DAC that it could be overwhelming/annoying.
> 
> 
> 
> ...


Hi all,

First, @A2029 - thanks for the explanation, graphs, and knowledge-sharing on CCS.

I’ve had several (quite welcome) PMs asking for thoughts on the _Blue Halo_, so why not post some? I'll share some _extremely initial impressions_ starting with a few caveats; 

I’ve had < 1w with the amp. We are all realistic enough to know that _it takes real time to generate real impressions_. Who knows how much of this will change as I listen more so _legit cave_!
I firmly believe this (or any) amp needs 100-200h to burn in the components. It is at ~70h.
My past year of listening has been generally with the GOTL, so that is my primary point of reference. That amp is a tube exploring versatility machine. When comparing vs GOTL, I mean comparing vs the "best" relevant setups (IMO) _I’ve_ had. I have gotten many and some expensive tubes for use on the GOTL. One key goal for the Blue Halo was to use a bunch of tubes from within my collection. 
I also have had a Bottlehead Crack for a little while now. It has also inspired some commentary and is a point of reference. _(While I like the Crack FYI, it is not at the same level as the Blue Halo or GOTL.) _
I listen to 90+% electronic music, so that does frame my listening.
So far, the Blue Halo evokes a few keywords like; _clear, controlled, _and_ dynamic_.

Tube-wise, so far I’ve only tried 1) GEC 6J5Gs, 2) Fivre 6C5Gs, and 3) RCA 6N7Gs. So far, while they all sound good, I'm loving the Fivres.
On GOTL I thought the Fivre 6C5Gs sounded delicate and spacious, but somewhat lacking in low end. You could compensate somewhat by changing outputs FWIW. _These tubes_ sound excellent/better on Blue Halo IMO

The clarity and imaging is generally strong. I can sense the space between instruments well. The individual images seem "genuine" and palpable, not sketched or insubstantial. (Often, IMO solid state amps fail this "image genuineness" criteria, they can be very clean/clear but somehow sound wrong)
Micro-dynamics; I’ve even had some “I’ve never heard that sound before” (in songs I know well) moments. 

The amp is tonally balanced (no part of the frequency spectrum is unduly emphasised) 
Very good resolution, able to reveal details quite capably 
The bass is nicely controlled and amply present. It isn’t loose, wobbly or lacking at all. This aspect of the dynamics in the low end is pretty great.
Perhaps not rational, but I feel like I can hear the CCS-effects similarity to my experience with the Crack. When I moved from no-CCS to CCS on the Crack I felt a veiling removed, more clarity - especially in the upper part of the range. 
Solid soundstage width/ presentation. 
Very quiet background.  This was a design priority for Mischa and specific design aspects address this directly. Noisy tubes will still be audibly noisy of course, but the amp itself is quiet.
With all this talk of "clean" and "quiet", I don’t want to evoke unduly solid-state amp feelings (not that there is anything wrong with 'em!). This thing is quite clearly a valve amp, with all the character and good things that means for the sound. 
GOTL evokes words like: _versatile, smooth, _and_ 3d_.

It is like a Swiss army knife of _tube exploration_. (The Blue Halo does offer plenty of exploration options mind you!). 
So far my impression is that the GOTL has slightly less clarity compared to the Blue Halo. This is likely the (often desired) harmonic distortions generated by all sorts of different tubes, and the presence of output tubes at all. In GOTL, I suspect as you vary compatible tubes, some will be less well optimised than others, but still produce pleasing sounds. 
You can control the sound many varied and lovely places (even to places you wouldn’t want it!). For example, if you want bass THUNDER, you can construct it, but at cost of other qualities. This is sometimes what you want of course, to make the sound you want. I imagine this will be true to some degree w/ Blue Halo too, especially through mixing “double drivers” (i.e.; using all 4 slots at once on the Blue Halo). 
Perhaps some more 3dness vs Blue Halo, but at cost of clarity probably (again, this is probably that "sometimes desired harmonic distortion” that causes this).
It took me more work to get a quiet background. I’ve gotten pretty it quiet but it was work. 
This is _far from my final word_, and may in fact be substantially different after some time passes. What I am sure will not change is that the _Blue Halo is certainly a quality, very enjoyable amp_. 

I have a lot more listening to do. Some things I will to try/do. This will take some time. 

Try C3Gs
Try AnM 6J7Gs via adapters
Try N within the same tube family (For 6J5*s I'll try; Osram 6J5G, Mullard 6J5G, KenRad 6J5, Fivre 6J5GT). To feel out the range of differences, I’d like to explore the changes within the same family. I believe this will be less than with the GOTL, but some amount TBD (largely due to the CCS as mentioned by Mischa above). 
Try Visseaux 6J7Gs (they are NOS, so I’d like to let the amp burn in 1st). 
I plan to use Blue Halo for 1M, then rotate back GOTL for a few weeks to get perspective.
A/B compare/contrast after 1M w/ Blue Halo, burn-in completed and some rotation back to GOTL. 
As I imagined, I love my GOTL, and I my dating with Blue Halo seems ever more promising! <<swoons>> #ampolygamy 

So far, these offer very pleasant and complimentary designs for "amp rolling". 

While the Blue Halo is early on the product’s life, I wager Mischa will get busier with requests as initial users start commenting and the good words get out. For now the BH is attainable, so … think about it if you are seeking a lovely OTL amp. It is a _very competitive amp in its range_. The build finish/polish is also excellent FYI. I’m looking forward to spending more time listening. 

Cheers,
Chris

And as this post draws to a close, I'm listening to this presently:


Here is the amp with those nice Fivres in there. I think @raindownthunda also likes these tubes at the moment.


----------



## Zachik

chrisdrop said:


> #ampolygamy


Love it


----------



## canfabulous

I think juggling multiple sweethearts is a pre-requisite skillset to dating head-fi...


----------



## LoryWiv

canfabulous said:


> I think juggling multiple sweethearts is a pre-requisite skillset to dating head-fi...


Funny this topic should arise. Please see my post in another thread just moments ago *here*.


----------



## canfabulous

LoryWiv said:


> Funny this topic should arise. Please see my post in another thread just moments ago *here*.


Aha Hah!  Feliks Audio... I saw her first!!!  

Seems like the Blue Halo might be the hot new thing on the block though.


----------



## LoryWiv

canfabulous said:


> Ahhh Feliks Audio... I saw her first!!!


Elise is mine, damnit...but have you seen her older sister Euforia?


----------



## magicman2020

canfabulous said:


> Seems like the Blue Halo might be the hot new thing on the block though.


#BlueHalo
Don't worry I only have eyes.. err ears for you.


----------



## LoryWiv

magicman2020 said:


> #BlueHalo
> Don't worry I only have eyes.. err ears for you.


Right, until the next sexy thing glows blue and orange at you. Woo Woo.


----------



## canfabulous

LoryWiv said:


> Elise is mine, damnit...but have you seen her older sister Euforia?



Dating her right now!


----------



## mordy

A2029 said:


> Using generalities, a CCS gives a more clear/defined/transparent and "hifi-ish" tone, so to speak. It can lift veils that let you hear more of the nuances of the recording (micro/macrodynamics) and of the upstream gear. It comes at the cost of being more transparent and having less distortion/warmth, so there is the potential of hearing more of the "junk" in some poorly recorded tracks, and potentially hearing more nuances of the DAC. If your ears are sensitive to delta-sigma oversampling DACs (especially certain poor implementation of the older Sabre chips), then having a delta-sigma DAC + highly transparent amp with CCSs + highly transparent headphone can give so much transparency of the DAC that it could be overwhelming/annoying.
> 
> 
> 
> ...


Hi A2029,
Thank you for your detailed reply. What comes to my mind is the difference between an impressionist painting and a photograph....




 I I am wondering if the CCS endowed amp captures the "soul" of the music to the same extent as a good tube amp without CCS.....


----------



## A2029

mordy said:


> Hi A2029,
> Thank you for your detailed reply. What comes to my mind is the difference between an impressionist painting and a photograph....
> I I am wondering if the CCS endowed amp captures the "soul" of the music to the same extent as a good tube amp without CCS.....



Hi Mordy,

I like that analogy. There are those who like a purely solid state design with ultra ultra low distortion - kind of like a super high resolution 40+ megapixel photo or an 8K video. Continuing the analogy, some solid state seems to make the images overly sharp, to make certain features stand out even more, and their images are unnatural looking and the over-sharp nature can become unpleasant to look at for very long. At the other extreme, there are tube amps that are very "tubey", akin to an impressionist painting where the color/line boundaries are blurred and a lot of creative license is used. Makes for very relaxing art to view as the brain can just relax and doesn't overwhelm with detail, but it doesn't have the highest accuracy in representing the original scene and it homogenizes a good deal of the microscopic elements (i.e. less of those "I've never heard that sound before" moments). 

I think what it all comes down to is personal preference. My personal preference is for amps using a CCS that convey as much of the original scene (aka as much of the original sound recordings - with warts and all) but with just enough 2nd harmonic distortion from the tubes to "smooth over" some of the micro rough edges and prevent the sound from being "too sharp" or unnatural, so to speak. In my mind, that gives the closest representation of what the truth of the recording is, while still being pleasant to listen to long term. The Blue Halo, for instance, has very low distortion for a tube amp - somewhere in the range of 0.03-0.06% THD at ~1.4V rms using a 6SN7 tube (6.5mW into 300ohm load, ~107dB listening level on a Verite C). This means IMO that it will be very transparent to what the recording holds, showing off the sharp/etched nature of poorly recorded material, and really shining on well recorded albums. With very linear & low distortion tubes such as the 6SN7 or 6J5s this also means that there is not much tube distortion/warmth added to the sound. Other tubes (e.g. 12AU7 and others) are less linear than the 6SN7/6J5s, so give more distortion and more tube qualities to the tone of the Blue Halo. I have a nice Philips Holland 12AU7 that I enjoy rolling in to the Blue Halo during testing to give more warmth and a relaxing listen. To go far into the sphere of higher distortion asks for the use of bigger power tubes and an output transformer - with the output transformer especially giving a lot of the transformer distortion tone.

Best,
Mischa


----------



## mordy

Thanks again for your thoughtful answer. 
Many years ago I heard a Dynaco preamplifier (PAS 3X) that had a three position switch that allowed you to expand the sound stage. I am wondering if an amp could be made that allows you to switch from musical to analytical, or stages in between. along the lines you described above.


----------



## Zachik

mordy said:


> Thanks again for your thoughtful answer.
> Many years ago I heard a Dynaco preamplifier (PAS 3X) that had a three position switch that allowed you to expand the sound stage. I am wondering if an amp could be made that allows you to switch from musical to analytical, or stages in between. along the lines you described above.


@mordy - some amps have a switch to change from Triode to Ultra Linear mode. Cayin's amps come to mind.
That is definitely something I will seriously consider in my next amp, whenever and whatever that happens... 
As for playing with sound stage expansion - funny coincidence as I have enroute the following little gadget:





The Foz SS-X is a small box that does 4 things:
1) Tube buffer
2) Bass Control
*3) Soundstage Expander*
4) Three position input switcher 

So, if you plug it between your DAC and amp - you can play with sound stage width (and some bass control)  
Pretty cool for less than $400...


----------



## A2029

mordy said:


> Thanks again for your thoughtful answer.
> Many years ago I heard a Dynaco preamplifier (PAS 3X) that had a three position switch that allowed you to expand the sound stage. I am wondering if an amp could be made that allows you to switch from musical to analytical, or stages in between. along the lines you described above.



Hmmm, that's a really cool idea, something that I'd have to think a good deal about how to do well. Some headphone amps use proprietary crossfeed circuits to give a more "speaker like", out of head experience. Simple crossfeed can also be done using software on the computer. In some amp circuits it could potentially be possible to implement a CCS bypass switch and some other tweaks to increase distortion; I'll have to think more about how exactly this would be done when I have more free time (probably next summer) and it may become an available upgrade option a ways down the road.


----------



## canfabulous

A2029 said:


> Hmmm, that's a really cool idea, something that I'd have to think a good deal about how to do well. Some headphone amps use proprietary crossfeed circuits to give a more "speaker like", out of head experience. Simple crossfeed can also be done using software on the computer. In some amp circuits it could potentially be possible to implement a CCS bypass switch and some other tweaks to increase distortion; I'll have to think more about how exactly this would be done when I have more free time (probably next summer) and it may become an available upgrade option a ways down the road.



Crossfeed is an interesting one.  The Chord DACs do a pretty good job of it in my experience.  The Euforia has a cross feed circuit... I switched it on once... immediately switched it off as it was the least like speaker presentation I'd ever heard as everything became muddy and muffled (to my ears anyhow).  A nice feature to have, if it's done well though.


----------



## canfabulous (Sep 21, 2020)

mordy said:


> Thank you for your detailed reply. What comes to my mind is the difference between an impressionist painting and a photograph....
> I am wondering if the CCS endowed amp captures the "soul" of the music to the same extent as a good tube amp without CCS.....



This talk of soul reminds me of the following video from one of my favourite YouTubers and music professionals.  I think he very eloquently explains why some of us prefer that dose of harmonic chaos.  There's a few thought provoking things said in the comments section too.


----------



## mordy

canfabulous said:


> This talk of soul reminds me of the following video from one of my favourite YouTubers and music professionals.  I think he very eloquently explains why some of us prefer that dose of harmonic chaos.  There's a few thought provoking things said in the comments section too.


Link?


----------



## canfabulous

mordy said:


> Link?


LOL Fixed.


----------



## leftside

I received a new DAC on Friday, so I thought I'd do the "black background" test. I can confirm that even the bigger brother to the Blue Halo - the "V6" (aka Thunder) is also very quiet. Obviously, this is also dependant upon source components and tubes, but with my preamp at 90 (100 is the max) and the V6 at max, it is silent. It's only when I take the preamp past 90 that I can hear any hiss at all. And this might well be from the DAC (3 tubes), preamp (4 tubes in the linestage) or one of the 8 tubes in the V6. 

I'm very careful to do these tests, because if I accidentally played music I'd probably not only blow my headphones, but also my ears, head, and roof off the house. Typically I listen at about the 12 o clock position on the V6 (half way on the dial) and 50 on the preamp. Anything past 65 is painful after a few seconds (even though the pain is good...)

Having a black background at ear splitting levels is not my primary goal when buying music equipment though. As long as I can't hear any noise during quiet passages, then I am happy.


----------



## chrisdrop

leftside said:


> I received a new DAC on Friday



You can't just leave that out there... picture or it didn't happen! What'd ya get?!


----------



## magicman2020

leftside said:


> I received a new DAC on Friday,


I guess this is what's known as a Leftside cliffhanger. 
You have to stay tuned.


----------



## leftside

chrisdrop said:


> You can't just leave that out there... picture or it didn't happen! What'd ya get?!





magicman2020 said:


> I guess this is what's known as a Leftside cliffhanger.
> You have to stay tuned.


 Since @Monsterzero told me about his TRP, I've been waiting and saving very patiently (for over a year) to also get one. A TRP appeared on the used market, so I grabbed it. I posted some thoughts here:
https://www.whatsbestforum.com/threads/lampizator-golden-atlantic-trp.27809/page-62#post-675029

I'm happy to report that the 1101 Audio headphone amp scales very nicely with the new DAC, and I can hear the improvements with the DAC through the amp and headphones, as I can with my main speakers.


----------



## Zachik

leftside said:


> Since @Monsterzero told me about his TRP, I've been waiting and saving very patiently (for over a year) to also get one. A TRP appeared on the used market, so I grabbed it. I posted some thoughts here:
> https://www.whatsbestforum.com/threads/lampizator-golden-atlantic-trp.27809/page-62#post-675029
> 
> I'm happy to report that the 1101 Audio headphone amp scales very nicely with the new DAC, and I can hear the improvements with the DAC through the amp and headphones, as I can with my main speakers.


I upgraded a year ago to the little brother - the Lampizator Amber 3. 
I have been a skeptic, expecting not to hear an improvement vs. my Metrum Amethyst which I thought was pretty good. Boy, was I wrong... 
I can only imagine the TRP is yet another step up.


----------



## leftside

Zachik said:


> I upgraded a year ago to the little brother - the Lampizator Amber 3.
> I have been a skeptic, expecting not to hear an improvement vs. my Metrum Amethyst which I thought was pretty good. Boy, was I wrong...
> I can only imagine the TRP is yet another step up.


I was highly skeptical that the TRP was simply a GA with tube rolling capabilities. I too was wrong. That new 53 engine is superb. Your Amber 3 has that engine, and I presume the Amber 3 is very close to the TRP. Perhaps the TRP can be viewed as the Amber 3 with tube rolling capabilities.


----------



## Monsterzero

leftside said:


> Since @Monsterzero told me about his TRP, I've been waiting and saving very patiently (for over a year) to also get one. A TRP appeared on the used market, so I grabbed it. I posted some thoughts here:
> https://www.whatsbestforum.com/threads/lampizator-golden-atlantic-trp.27809/page-62#post-675029
> 
> I'm happy to report that the 1101 Audio headphone amp scales very nicely with the new DAC, and I can hear the improvements with the DAC through the amp and headphones, as I can with my main speakers.


Yeah,I love my TRP. Its a great sounding DAC. Speaking of which Fred is gonna lend me his pair of Tesla EI51s this weekend. Curious about what the hype is about and how they stack up vs. my Gold Lion Kt77s


----------



## Xcalibur255

Welp, the gamble I took on those tubes from India seem to have paid off.  I got exactly what was shown in the pictures, and the tubes appear to be true NOS in their original packaging.  I thought the 5 year old amplitrex test result were a little questionable, but the tubes sure seem to be the real deal.  The shipping was also extremely fast.  They came much faster than the estimate.

So with that said I have something of a public service announcement.  For whatever reason this seller's items don't seem to show up in the main search results on eBay, but if you look directly at their item listings and search within that for 6J5 these tubes DO show up.  They have quite a few nice listings right now including Mullard and Brimar pairs in original boxes.  There are also some GEC L63 and Ferranti pairs but they don't have the same nice looking test figures that the Mullards and Brimars do.  Assuming those test numbers are genuine, but like I said the pair I received absolutely appears to be real NOS so I'm inclined to think everything is on the up and up with these listings including their test figures.

https://www.ebay.com/sch/m.html?_ssn=totempole_999&_armrs=1&_from=R40&_sacat=0&_nkw=6j5&rt=nc

One thing I can't do is run them in an amp and verify there are no noise or other issues, but that's the risk I took buying tubes for an amp I don't have yet.  Hopefully all will be well when the time comes to use them.


----------



## Xcalibur255

My phone takes crappy pictures unfortunately.  Or maybe I do.


----------



## Xcalibur255

*smacks forehead*  I actually meant to post this in the 6J5 tube lover's thread.  I guess it's fine for it to be here too, I'll just drop a link over there.


----------



## paradoxper

Mischa, with the Blue Halo taking precedent for nominal dynamic loads, do you have any playful ideas for an amplifier solely with more insensitive drive in-mind?
Driving an Abyss in ultra-linear seems a common idea to eek out as much power output.

If you'd prefer this be taken to PM, please let me know.

Thank you.


----------



## A2029

paradoxper said:


> Mischa, with the Blue Halo taking precedent for nominal dynamic loads, do you have any playful ideas for an amplifier solely with more insensitive drive in-mind?
> Driving an Abyss in ultra-linear seems a common idea to eek out as much power output.
> 
> If you'd prefer this be taken to PM, please let me know.
> ...



Hi paradoxper,

You bet, I have two products that can meet the demands of high output power into low impedance, low sensitivity loads:

1) SET transformer coupled amplifier. I can use any driver tube and any output tube of preference. Common output tubes for high(er) power output into low impedance loads include the 300B or the EL34/6L6/KT77/KT88/KT120/KT150 family of tubes. I tend to stay away from ultra-linear as it can potentially sound less clean than a triode/pseudotriode wiring scheme.

2) Sometime in the near(ish) future I will be releasing a pure class A tube-hybrid amplifier that can produce large amount of power into low impedance loads and can even be used for highly efficient speakers. In this tube-hybrid, the output mosfet doesn't do any amplification, just follows the output from the tube, so nice 2nd harmonic distortion from the tube combined with the output power of solid state. A little more distortion than the Blue Halo, and less power into high impedance loads than the Blue Halo, but able to drive difficult low impedance loads such as the HE-6. Will also likely have the ability to increase or decrease output power in order to decide how hot running the amp should be (user selectable Class A bias current).

Cheers,
Mischa


----------



## chrisdrop

Hey Mischa (tagging you @A2029),

Question for you on the Blue Halo. When running 6N7*s in the amp, how are the 2 triodes in each tube used?

Tx v much,
Chris

N.B. just to provide photo entertainment, here is the Blue Halo with 2x 1953 Visseaux 6N7GTs. Tx for the tip @GDuss.


----------



## A2029

chrisdrop said:


> Hey Mischa (tagging you @A2029),
> 
> Question for you on the Blue Halo. When running 6N7*s in the amp, how are the 2 triodes in each tube used?
> 
> ...



Hi Chris,
It wires both of the anodes in parallel, and both of the grids in parallel.
Best,
Mischa


----------



## Zachik

A2029 said:


> SET transformer coupled amplifier. I can use any driver tube and any output tube of preference. Common output tubes for high(er) power output into low impedance loads include the 300B or the EL34/6L6/KT77/KT88/KT120/KT150 family of tubes. I tend to stay away from ultra-linear as it can potentially sound less clean than a triode/pseudotriode wiring scheme.


Already owning (and loving) Glenn's OTL and EL3N SET amps, the latter with customization for using EL34/6L6/KT77/KT88/KT120/KT150 family of tubes - I am thinking my next amp (*in addition*) might be a 300B amp... needs to be different sounding, and I think 300B would sound different.
@A2029 Mischa, I am curious... when you think of 300B amp:
What would the topology be?  Which drivers?  Is it possible to add a switch for Triode vs. ultra-linear mode (to get 2 sound signatures / flavors)?
Would it be able to drive speakers in addition to headphones (and how much wattage can it produce for speakers)?

Very dangerous for me to even start thinking about those things... never ends well (for my wallet)!


----------



## A2029 (Sep 25, 2020)

Zachik said:


> Already owning (and loving) Glenn's OTL and EL3N SET amps, the latter with customization for using EL34/6L6/KT77/KT88/KT120/KT150 family of tubes - I am thinking my next amp (*in addition*) might be a 300B amp... needs to be different sounding, and I think 300B would sound different.
> @A2029 Mischa, I am curious... when you think of 300B amp:
> What would the topology be?  Which drivers?  Is it possible to add a switch for Triode vs. ultra-linear mode (to get 2 sound signatures / flavors)?
> Would it be able to drive speakers in addition to headphones (and how much wattage can it produce for speakers)?
> ...



Topology would be pure class A, zero feedback, SET. The 300B is a triode, so can't do ultralinear as ultralinear requires a tetrode/pentode with screen (EL34/6L6/KT77/KT88/KT120/KT150 family usually used). Driver choice is pretty open ended. I'm inclined to go with a 6SN7 socket and dual 6J5 sockets (either 6SN7 or the 6J5s used, not at the same time). Through the use of adapters the C3G and many other tubes could be used.

Usually speaker SET amps and headphone SET amps are exclusive. It is hard for transformer winders to make transformers that would have very good performance for both headphone and speaker use, and usually some compromises have to be made. A 5000 ohm primary output transformer with 8 ohm secondary for speaker use can give around 8W power using the 300B. Same 8W can be had into a headphone with a secondary winding specific for that headphone (e.g. 300ohm winding). If you would like to do both headphones and speakers, IMO best to get a transformer made for the speakers, then when you plug headphones in you'd flip a switch for headphones that would put an 8 ohm load in parallel with the output - but this would only give slightly over 100mW output power into 300ohms. 100mW would allow you to hit just over 115dB peaks with the Verite's (usually enough power unless you listen very loud or listen to some insanely dynamic music).


----------



## Zachik

A2029 said:


> The 300B is a triode, so can't do ultralinear as ultralinear requires a tetrode/pentode with screen


Got it.



A2029 said:


> I'm inclined to go with a 6SN7 socket and dual 6J5 sockets


Interesting - a friend own the Cayin HA-300, which I have auditioned just before covid landed upon us, and it sounded pretty great (with stock Chinese new production tubes).
Here is the amp I am referring to:  https://en.cayin.cn/products_info?itemid=112
This one also uses 6SN7 as drivers (no 6J5 option).



A2029 said:


> Through the use of adapters the C3G and many other tubes could be used.


I think the 300B amps that Glenn has built in the past use C3g as drivers. Unless there is a good reason to use C3g - I personally would probably opt for the 6SN7 and/or 6J5. Love those tubes as drivers (on my GOTL). 6N7 are also great, BTW, and it seems on Blue Halo can be used without an adapter if I am not mistaken.



A2029 said:


> Usually speaker SET amps and headphone SET amps are exclusive. It is hard for transformer winders to make transformers that would have very good performance for both headphone and speaker use, and usually some compromises have to be made. A 5000 ohm primary output transformer with 8 ohm secondary for speaker use can give around 8W power. Same 8W can be had into a headphone with a secondary winding specific for that headphone (e.g. 300ohm winding). If you would like to do both headphones and speakers, IMO best to get a transformer made for the speakers, then when you plug headphones in you'd flip a switch for headphones that would put an 8 ohm load in parallel with the output - but this would only give slightly over 100mW output power into 300ohms. 100mW would allow you to hit just over 115dB peaks with the Verite's (usually enough power unless you listen very loud or listen to some insanely dynamic music).


The Cayin HA-300 that I was referring to above does have speaker taps, claims to have the same 8W / channel for speakers that you mention above, but does output 1.1W / channel in Low Impedance, up to 5W / channel in high Impedance!  No idea if they're doing something smart there, or some painful compromise that hurt sound quality... So in theory the 5W is into 250 ohm??? Quite a bit more than 100mW 
To clarify: I am not interested in headphone and speakers being active at the same time!


----------



## A2029

Zachik said:


> I think the 300B amps that Glenn has built in the past use C3g as drivers. Unless there is a good reason to use C3g - I personally would probably opt for the 6SN7 and/or 6J5. Love those tubes as drivers (on my GOTL). 6N7 are also great, BTW, and it seems on Blue Halo can be used without an adapter if I am not mistaken.




C3G are often used as they have higher amplification factor than the 6J5. Running the 6J5, may not be able to get the same 8W out of the amp from a standard 2V rms DAC input. May only get 7-7.5W. If the DAC doesn't give the standard 2V rms, then the C3G (or other high amplification factor tube) would be needed to get max power from the amp. 6J5 sockets can usually be wired for running the 6N7 as well.




Zachik said:


> The Cayin HA-300 that I was referring to above does have speaker taps, claims to have the same 8W / channel for speakers that you mention above, but does output 1.1W / channel in Low Impedance, up to 5W / channel in high Impedance!  No idea if they're doing something smart there, or some painful compromise that hurt sound quality... So in theory the 5W is into 250 ohm??? Quite a bit more than 100mW
> To clarify: I am not interested in headphone and speakers being active at the same time!



Interesting, the Cayin HA-300 has low, medium and high impedance switch. The output transformers must either have separate windings for each impedance, or multiple windings that are linked in series for the higher impedance output. It would affect the performance of the transformer to some degree having the windings for both (I believe it would have more high frequency roll off), but as you've found out can still sound very good (I wasn't trying to suggest that having a transformer built for both headphones and speakers would sound bad necessarily, just slightly less performance than a transformer specifically made for one or the other). If a transformer winder does just two impedances (e.g. 8 ohm and 300 ohm) with completely separate windings that may give the best performance for an amp built to do both. If you had a separate winding for 300 ohm, you may be able to get close to the full 8W output into the 300ohm - headphones could easily die if turned up to full, lol


----------



## Zachik

A2029 said:


> C3G are often used as they have higher amplification factor than the 6J5. Running the 6J5, may not be able to get the same 8W out of the amp from a standard 2V rms DAC input. May only get 7-7.5W. If the DAC doesn't give the standard 2V rms, then the C3G (or other high amplification factor tube) would be needed to get max power from the amp.


Got it. So, if 7W / channel is enough - no need to go with C3g drivers? 
Might sound naive, but if 7W is too weak, would really 8W be enough? 



A2029 said:


> Interesting, the Cayin HA-300 has low, medium and high impedance switch. The output transformers must either have separate windings for each impedance, or multiple windings that are linked in series for the higher impedance output. It would affect the performance of the transformer to some degree having the windings for both (I believe it would have more high frequency roll off), but as you've found out can still sound very good (I wasn't trying to suggest that having a transformer built for both headphones and speakers would sound bad necessarily, just slightly less performance than a transformer specifically made for one or the other). If a transformer winder does just two impedances (e.g. 8 ohm and 300 ohm) with completely separate windings that may give the best performance for an amp built to do both


I have auditioned the Cayin HA-300 only with headphones (which sounded awesome!). 
No idea how speakers driven by it sound, to be 100% honest. 



A2029 said:


> If you had a separate winding for 300 ohm, you may be able to get close to the full 8W output into the 300ohm - headphones could easily die if turned up to full, lol


Honestly, 1W into 300ohm is probably more than enough. Not looking for 8W into 300ohm 
But, the 100mW you mentioned earlier is too wimpy...


----------



## A2029

Zachik said:


> Got it. So, if 7W / channel is enough - no need to go with C3g drivers?
> Might sound naive, but if 7W is too weak, would really 8W be enough?
> 
> 
> ...



Exactly, if using sources that put out 2V RMS (most, but not all DACs) and if not hitting 100% power is okay (some guys are all about how big of a number they have ) then no need for the C3G drivers.

Yup, the 100mW is on the wimpy side. Having 8W capability means that the first watt (or first 100mW even) will have less distortion


----------



## Xcalibur255

I found myself wondering the other day what would happen if one were to put a 6SN7 into a socket meant for a 6J5.  Would just one section operate perhaps?  I was tempted to ask, then scolded myself for being lazy because I'm capable of looking up the data sheet and finding out for myself.  Seeing that pin 2 is for a heater on the 6J5 and for a plate on a 6SN7 definitely answers the question!


----------



## leftside

There is a reason why Glenn uses the C3g with the 300B amp (with his design), and it's not to do with extracting the most amount of power. From Glenn when talking about the Woo WA5 using the 6SN7/300B combo:

"The 6SN7 is not a proper driver for a 300B The Woo only uses 1/2 of the 6SN7 to do the driving so this is essentially the same as the one 6SN7 in the BA. After 10 or more years of dealing with the 300B trying the 6SN7 then going to the 6DN7 that is really 1/2 a 6SN7 and 1/2 a 6BL7 and also trying the 6BM8/ECL82. I found that #1) the 6SN7 cannot drive the 300B properly #2) even though the 6DN7 and 6BM8 can drive the 300B neither of these tubes sound that great in the first place.
So I went to the #10/210 this sounded fantastic but I had to go through the DC on the filament thing to use this tube. Especially as the driver It had to run it on DC. The #10 can drive the 300B with 1.5 watts.  Recently I have experimented with the C3g and this tube can also drive the 300B with 1.5 watts of drive and not have to run the filament on DC. And these tubes sound almost as good as the #10 and have more gain I have sold a couple of amps that use this tube as the driver for a 300B to Clayton you can ask him about the SQ. These company's have to give the people what they want and everyone wants a 6SN7 so they can tube roll."

I appreciate the above is only relevant to Glenn's design, and this might not be the same in other designs, but I wanted to provide some background on why the decision to use the C3g in the 300B amp has been made. The C3g + 300B gives a very neutral, airy and detailed sound. Again, as the designer intended. I also really like having the C3g tubes in the amp Mischa made for me, as it changes the sound more than any variation between 6SN7 or 6J5 tubes.


----------



## A2029 (Sep 26, 2020)

leftside said:


> There is a reason why Glenn uses the C3g with the 300B amp (with his design), and it's not to do with extracting the most amount of power. From Glenn when talking about the Woo WA5 using the 6SN7/300B combo:
> 
> "The 6SN7 is not a proper driver for a 300B The Woo only uses 1/2 of the 6SN7 to do the driving so this is essentially the same as the one 6SN7 in the BA. After 10 or more years of dealing with the 300B trying the 6SN7 then going to the 6DN7 that is really 1/2 a 6SN7 and 1/2 a 6BL7 and also trying the 6BM8/ECL82. I found that #1) the 6SN7 cannot drive the 300B properly #2) even though the 6DN7 and 6BM8 can drive the 300B neither of these tubes sound that great in the first place.
> So I went to the #10/210 this sounded fantastic but I had to go through the DC on the filament thing to use this tube. Especially as the driver It had to run it on DC. The #10 can drive the 300B with 1.5 watts.  Recently I have experimented with the C3g and this tube can also drive the 300B with 1.5 watts of drive and not have to run the filament on DC. And these tubes sound almost as good as the #10 and have more gain I have sold a couple of amps that use this tube as the driver for a 300B to Clayton you can ask him about the SQ. These company's have to give the people what they want and everyone wants a 6SN7 so they can tube roll."
> ...



It's true, a 6SN7 using a plate loading resistor has high output impedance (10K ohm) that it is not good to feed into the large capacitance of the 300B grid. A 6SN7 using a CCS with the output taken from the tube plate also has high output impedance (10K ohm) that it is not good to feed into the large capacitance of the 300B grid. To get around this, the "Mu" output from a CCS can be taken - this drops the output impedance down from 10K to between 200-500 ohm, allowing even tubes with extremely high plate resistance to drive the 300B. When using the CCS Mu output with 6SN7 or 6J5 tube, the only loss is a loss of output power from the amp due to having less amplification per section. Good thing about the 6J5 socket is that it is easy to get C3G to 6J5 adapters so that the C3G can be used when desiring full output power from the amp. Personal preference will dictate which sound signature between the 6J5 and the C3G is preferred to be matched with the 300B tube. The Mu output is the reason why the Thunder amp is able to drive the grids of six 6AS7 sections no matter which tube is being run


----------



## leftside

A2029 said:


> It's true, a 6SN7 using a plate loading resistor has high output impedance (10K ohm) that it is not good to feed into the large capacitance of the 300B grid. A 6SN7 using a CCS with the output taken from the tube plate also has high output impedance (10K ohm) that it is not good to feed into the large capacitance of the 300B grid. To get around this, the "Mu" output from a CCS can be taken - this drops the output impedance down from 10K to between 200-500 ohm, allowing even tubes with extremely high plate resistance to drive the 300B. When using the CCS Mu output with 6SN7 or 6J5 tube, the only loss is a loss of output power from the amp due to having less amplification per section. Good thing about the 6J5 socket is that it is easy to get C3G to 6J5 adapters so that the C3G can be used when desiring full output power from the amp. Personal preference will dictate which sound signature between the 6J5 and the C3G is preferred to be matched with the 300B tube. The Mu output is the reason why the Thunder amp is able to drive the grids of six 6AS7 sections no matter which tube is being run


Great info!


----------



## Zachik

A2029 said:


> It's true, a 6SN7 using a plate loading resistor has high output impedance (10K ohm) that it is not good to feed into the large capacitance of the 300B grid. A 6SN7 using a CCS with the output taken from the tube plate also has high output impedance (10K ohm) that it is not good to feed into the large capacitance of the 300B grid. To get around this, the "Mu" output from a CCS can be taken - this drops the output impedance down from 10K to between 200-500 ohm, allowing even tubes with extremely high plate resistance to drive the 300B. When using the CCS Mu output with 6SN7 or 6J5 tube, the only loss is a loss of output power from the amp due to having less amplification per section. Good thing about the 6J5 socket is that it is easy to get C3G to 6J5 adapters so that the C3G can be used when desiring full output power from the amp. Personal preference will dictate which sound signature between the 6J5 and the C3G is preferred to be matched with the 300B tube. The Mu output is the reason why the Thunder amp is able to drive the grids of six 6AS7 sections no matter which tube is being run


Thanks Mischa.  I wonder if that is the architecture used in the Cayin HA-300. That is probably the only 300B amp I have ever auditioned, at least longer than 3-4 minutes at CanJam, and really liked the way it sounded (with the stock Chinese 6SN7 and 300B tubes).


----------



## chrisdrop

Just a minor report for any interested listeners or Blue-Halo-anticipators. Mischa sent the amp with ~50h of amp use time. The amp changed nicely when getting probably just over 150 or so hours. A bit more smoothness added and subtle congestion removed - especially in the upper mids.

There is one confounder in here; the valves were also NOS (like 10h from use on my other amp), so it could be _them_ burning in. Hard to say!

I'm still sitting on largely the same inputs; ~90% of the total time. Minimising changing variables helps me hear more of what (I think) is going on. I couldn't resist a play for a few hours with some other tubes. Recently Fivre 6J5GTs also sounded nice - but not as nice as these 6C5Gs. Also rolled in some Visseaux 6N7GTs, but went back. I think those need some hours on them and I didn't want to start another pair of NOS tubes from scratch at this point of getting acquainted w/ Blue Halo. 

Sound good in my ear at the moment (if you like at all, get a quality version. The production sounds glorious).


----------



## chrisdrop

I hit the 200h of burn-in on the amp and swapped tubes today, as planned. C3Gs sounding solid so far. I think the Fivres, which I love, have somewhat emphasised mids. These C3Gs seem a bit more neutral. They are not shy in the low-end, nor are they bright/etched. With slightly less crowded mids, I think the imaging in some of the other areas is stronger.

Listening to a favourite:


----------



## magicman2020

It's beginning to look a lot like Xmas.
I just received my package from Santa Mischa. 
Folks it looks gorgeous!!


----------



## Zachik

@A2029 Mischa (or should I call you Santa Mischa ) - do you have a website? 
or do you list your Pure Power, cables, and amps just here on this thread?


----------



## magicman2020

Hi guys,

I'm just gonna drop this link for those of you searching for additional 
information/reviews on the Rockna Wavelight.
http://v2.stereotimes.com/post/rockna-audio-wavelight-pre-dac-–-followup-by-mike-wright/
Hope it helps.

Stay Safe,

Terry


----------



## A2029

Zachik said:


> @A2029 Mischa (or should I call you Santa Mischa ) - do you have a website?
> or do you list your Pure Power, cables, and amps just here on this thread?



I have the domain name (1101audio.com), but have yet to put together anything substantial for the site. All my current products are listed throughout this thread. I'll likely throw together a very simple site sometime soon (next 2-3 months) to give more info on everything I offer and more details on upgrade options, part selections, etc. (things that I get asked about quite often through PM).


----------



## Zachik

A2029 said:


> I have the domain name (1101audio.com), but have yet to put together anything substantial for the site. All my current products are listed throughout this thread. I'll likely throw together a very simple site sometime soon (next 2-3 months) to give more info on everything I offer and more details on upgrade options, part selections, etc. (things that I get asked about quite often through PM).


Mischa - an easier and faster option for you (for now at least):
Create a new thread ("1101 Audio Products" or something similar), and on the very 1st post list all the info that is spread out... That way, if someone like me want to read more about your products - super easy to find! 
Also, add a link in your signature.

In the future, all you have to do is update this 1st post to add products or update or discontinue products, etc.

Just my 2 cents...


----------



## leftside

magicman2020 said:


> It's beginning to look a lot like Xmas.
> I just received my package from Santa Mischa.
> Folks it looks gorgeous!!


Great looking stack.


----------



## L0rdGwyn

I am late to the party, but wanted to add a comment on the 300B driver stuff and mention some cool tubes.  The point was already made so sorry if I am repeating it, but the ideal 300B driver is one that is A) high enough gain to drive the 300B to clipping (maximize power output) B) low enough output impedance to drive the input / Miller capacitance of the 300B.  A low-pass filter is formed by the output impedance of the previous stage and the input capacitance of the 300B, using a lower plate resistance tube will increase the cut off frequency of that RC filter out of the audio band such that the amplifier can hit 20kHz bandwidth, that is what Glenn and others are referring to when they say "drive the 300B".  

The triode-strapped C3g is a good 300B driver as it has both of these features, adequate gain and low plate resistance (and thus, output impedance).  The D3a is commonly used as a 300B driver for the same reasons.  But like Mischa said, taking the mu-output of the driver tube CCS load pretty much solves the output impedance issue for many driver tubes.  Another popular approach is to use a buffer stage between the input tube and the 300B, either a cathode follower or FET source follower direct-coupled to the 300B grid.  This provides a very low output impedance and the ability to drive the 300B into partial A2 territory due to direct-coupling, eking out a bit more power.  The buffer also provides a very easy load for the input tube.

Some highly sought-after / unobtainium 300B driver triodes are the Western Electric 437A and the Telefunken EC8020.  These are very high transconductance high-gain triodes with low plate resistance, 437A go for around $600 a pair and EC8020 are pretty much extinct!  BUT you can get pretty similar specs to these guys though using triode-strapped pentodes like the C3g / D3a, or just take the mu-output of a CCS load.

Okay sorry, I hope I am not being intrusive, don't mean to hijack or anything, I mostly wanted to draw attention to these rare and interesting triodes!


----------



## A2029

L0rdGwyn said:


> I am late to the party, but wanted to add a comment on the 300B driver stuff and mention some cool tubes.  The point was already made so sorry if I am repeating it, but the ideal 300B driver is one that is A) high enough gain to drive the 300B to clipping (maximize power output) B) low enough output impedance to drive the input / Miller capacitance of the 300B.  A low-pass filter is formed by the output impedance of the previous stage and the input capacitance of the 300B, using a lower plate resistance tube will increase the cut off frequency of that RC filter out of the audio band such that the amplifier can hit 20kHz bandwidth, that is what Glenn and others are referring to when they say "drive the 300B".
> 
> The triode-strapped C3g is a good 300B driver as it has both of these features, adequate gain and low plate resistance (and thus, output impedance).  The D3a is commonly used as a 300B driver for the same reasons.  But like Mischa said, taking the mu-output of the driver tube CCS load pretty much solves the output impedance issue for many driver tubes.  Another popular approach is to use a buffer stage between the input tube and the 300B, either a cathode follower or FET source follower direct-coupled to the 300B grid.  This provides a very low output impedance and the ability to drive the 300B into partial A2 territory due to direct-coupling, eking out a bit more power.  The buffer also provides a very easy load for the input tube.
> 
> ...



Not intrusive at all, love the post.

Beautiful tubes! Only $1300 for the 437A over on tubedepot.com   

Another useful tube that fits the bill is the 6C45P - a very low distortion triode tube used in the Bottlehead Mainline and the ECP-L2. Problem with the 6C45P is that it is so high gm that people say that it "oscillates even while still in its box". Even when using a huge number of stoppers (plate, grid, and cathode), it tends to be very excitable with some ringing in the high frequencies if it is driven with much current (likes currents under 10mA).


----------



## L0rdGwyn

A2029 said:


> Not intrusive at all, love the post.
> 
> Beautiful tubes! Only $1300 for the 437A over on tubedepot.com
> 
> Another useful tube that fits the bill is the 6C45P - a very low distortion triode tube used in the Bottlehead Mainline and the ECP-L2. Problem with the 6C45P is that it is so high gm that people say that it "oscillates even while still in its box". Even when using a huge number of stoppers (plate, grid, and cathode), it tends to be very excitable with some ringing in the high frequencies if it is driven with much current (likes currents under 10mA).



$1,300 wow!  A set of five sold on auction the other day for around $500, a steal considering what they usually go for.  I was watching until the last second, I stayed my hand, but boy I was tempted...I have a problem with rare tubes  they say admitting it is the first step.  I'll have to take a look at the 6C45P, sounds interesting if it can be tamed, somehow I have never managed to lay ears on the Bottlehead Mainline...


----------



## Zachik

I for one prefer NOT to buy a custom amp with tubes that are impossible to buy. Maybe that's just me... 
I know Mischa already commented on that, but I am still curious why Cayin (for example) chose to use 6SN7s for drivers (in their HA-300 amp)?
Even compared to the C3g, the 6SN7 tubes are more common, and some (like their stock ST Chinese 6SN7s) are very pretty next to the 300B...





That is one very pretty amp!!!


----------



## A2029 (Oct 2, 2020)

Zachik said:


> I for one prefer NOT to buy a custom amp with tubes that are impossible to buy. Maybe that's just me...
> I know Mischa already commented on that, but I am still curious why Cayin (for example) chose to use 6SN7s for drivers (in their HA-300 amp)?
> Even compared to the C3g, the 6SN7 tubes are more common, and some (like their stock ST Chinese 6SN7s) are very pretty next to the 300B...
> 
> ...



I'm guessing that Cayin chose the 6SN7 because it's a well known tube that has a good reputation, sounds good and there is still a lot of stock on the market (plus the ST bottle tubes look great for photos). In psychology there is the "mere-exposure" effect, where people tend to prefer things merely because they see them so often. May be harder to sell an amp that uses tubes that few have heard about before such as an 6688 as a driver, even if the tube is cheaply available on the market and could sound as good.


----------



## magicman2020

Hey Guys,
The day anticipated for 7 months is finally here.
My Rockna Wavelight the last piece of my dream system has arrived.
Full review will follow after I have some time with it.
I want to thank @L0rdGwyn again for his brilliant recommendation to use @A2029 . Mischa's professionalism, knowledge and service made it one of the best buying experiences that I've ever had. No,Mischa is not paying me to say this. I wish lol. Seriously Mischa I can't thank you enough..
A huge shout out to @koven for his dac recommendation of the Rockna Wavelight. I'm not sure if you've seen the latest review in addition to Terry London’s very favourable one,  but here it is.
http://v2.stereotimes.com/post/rockna-audio-wavelight-pre-dac-–-followup-by-mike-wright/
Of course I gotta thank @Monsterzero for his recommendation of the ZMF Verite C. It's everything you said it was!!
Finally to @zach915m Zack and Bevin for your absolutely wonderful creation. I can tell you with certainty, It will be the centerpiece of my audio system forever!!


----------



## Monsterzero

magicman2020 said:


> Hey Guys,
> The day anticipated for 7 months is finally here.
> My Rockna Wavelight the last piece of my dream system has arrived.
> Full review will follow after I have some time with it.
> ...


Man I remember not too long ago you asking me for recs, and now look at you!!! Zero to game over in half a year! Well done. I hope you enjoy your setup. I bet it will sound killer!


----------



## magicman2020

Monsterzero said:


> Man I remember not too long ago you asking me for recs, and now look at you!!! Zero to game over in half a year! Well done. I hope you enjoy your setup. I bet it will sound killer!


Hi Darren, 
That almost seems like a lifetime ago when I look back on my audio journey to this point. I don't think Im done adding to this system.  Next year (after my wallet starts talking to me again) I will be adding a Rockna server. It will then be possible to connect my source to the dac via I2S. 
I know I've just got the system and  2 components still need burn in time. It still sounds incredible right out of the box. 
A monsterzero-like(ish) review to follow.


----------



## magicman2020

Hey Guys 

Sorry I feel like Robin Williams forgetting to thank his Mother in his Oscar winning speech. How you ask? Because I'm old lol
It was actual @leftside and @L0rdGwyn who pointed me to @A2029 Mischa . @leftside was instrumental in my decision after he relayed his thoughts on his newly built 1101 Audio "V6" amp Mischa had built him. My apologizes Leftside.


----------



## Zachik

A2029 said:


> I'm guessing that Cayin chose the 6SN7 because it's a well known tube that has a good reputation, sounds good and there is still a lot of stock on the market (plus the ST bottle tubes look great for photos). In psychology there is the "mere-exposure" effect, where people tend to prefer things merely because they see them so often. May be harder to sell an amp that uses tubes that few have heard about before such as an 6688 as a driver, even if the tube is cheaply available on the market and could sound as good.


I am of the opinion that a tube amp should look good!  Nothing wrong with ST bottle 6SN7 tubes - they really do look great  
Granted, if they make it sound bad - that won't be acceptable (but I did audition this amp, and it sounds great).
I have never heard of 6688, but if they sound better and are easy to buy (at reasonable prices) - I have no problem with that!  Hopefully, they would look good, too...


----------



## A2029

Zachik said:


> I am of the opinion that a tube amp should look good!  Nothing wrong with ST bottle 6SN7 tubes - they really do look great
> Granted, if they make it sound bad - that won't be acceptable (but I did audition this amp, and it sounds great).
> I have never heard of 6688, but if they sound better and are easy to buy (at reasonable prices) - I have no problem with that!  Hopefully, they would look good, too...



Agreed, the visual aspect is the cherry on top of great sound from an amp!

I just chose the 6688 at random (to fit with the sentence on the mere-exposure effect), haven't ever used it so not sure if it sounds good or not, may have to try it some day


----------



## Zachik

Mischa - I've asked you before about switch to toggle between triode and ultra linear modes.
You answered 300B tubes won't support it. 
How about driver tubes that support both modes and can drive 300B tubes? 
Just thinking out loud here...


----------



## A2029

Zachik said:


> Mischa - I've asked you before about switch to toggle between triode and ultra linear modes.
> You answered 300B tubes won't support it.
> How about driver tubes that support both modes and can drive 300B tubes?
> Just thinking out loud here...



Hmm, good question. Ultralinear operation usually uses a transformer tapped at some percentage (e.g. 43% for the KT88 family). With the use of an interstage transformer I believe that ultralinear for the driver tube could be possible when using a pentode/tetrode driver tube. One difficulty is that the optimal tap percentage changes from tube to tube. There were some white papers that came out in the past looking at different tapping points for certain families of tubes, but there are very few tubes that these studies were done for. Selecting an optimal tapping point for a driver tube may be a bit of a guessing game.

I didn't forget about your previous questions on the 300B a while back; it got my creative gears turning   It got me thinking about how to put in a switch to switch between CCS feeding the plate or resistor plate loading. I think the CCS vs resistor would be a better alternative than a triode vs ultralinear driver tube. I'm not the biggest fan of ultralinear in general as it is actually less linear than triode operation (despite the ultralinear name). The primary benefit to ultralinear is that for output tubes it gives greater power than triode, while maintaining lower distortion than pentode operation. I believe that the CCS & plate resistor switch would be feasible and a neat option.


----------



## chrisdrop

Today's roll:

2x RCA 6N7G matched (I think 1942). I really like the feature that you can plonk 6N7s into the 6J5 slots. These are sounding lovely. The amp is now just over ~200h and continuing to open up.


----------



## magicman2020

Day 3

I can't confirm much yet. However, 
I can confirm the co-pilot works as intended. No weight issues whatsoever. I'm off work right now, so my listening session are kind of all day affairs. 

One observation to report on the dac that is most noticeable right off the bat is how elongated the decay has gotten. Most enjoyable. 
Still primarily rocking the Osram/GEC L63's, although I have rotated thru all my pairs to see if they work. Happy that they do.


----------



## magicman2020

Day 8

The song does not remain the same....

It just keeps on improving over the previous day. 

Believe it or not, I started this review several times in the last couple of days and have struggled trying to find the right words to describe my early impressions of  my Blue Halo OTL , and the absolute sheer level of AWE and mind blowing moments it's delivering multiple times daily without gushing like a little school girl. 
I can offer you this much. I love this amp so much my wife is jealous!

I'm sure with the great popularity of the Glenn OTL in this community, I'll be asked, "is it better than a Glenn"? 
The simple answer Is, I have no idea. I've never heard one, so I can't say. 
What I can tell you is that the BH is really something special.
 Here we are at approximately 120 hours of burn in time. 
The amps' signature trade mark is its ultra black noise floor. Mischa has certainly delivered on his claim. All I hear at start up is equivalent to open air. The amp's transparency is also quite apparent. It simply just acts like sponge absorbing the sound and characteristics of whichever tube you decide to put in. 
My favourite tubes so far is the Tesla ECC 88 6922's. They're slightly brighter then the L63's while retaining a deep full natural sounding bass. The most jaw dropping thing about this tube, at least in my case,  is how it moved the sound stage back about 10-12 feet revealing an immersive 3D sound stage that is addictive to explore. 
To put it in a more visual context. I've been using Pretty Reckless's "Death by Rock and Roll“ as one of my comparison test tracks. 
At the beginning of this track you hear a woman in heels walking across the stage. 
In all other tubes, She seems to be walking behind you from left to right.
Not so in 6922's. The woman now walks from the stage TOWARDS YOU. This level of imagery plus the kaleidoscope of 3D effects has turned me into a Blue Halo junkie. @A2029 Mischa may have to start up support groups.

More impressions to come.


----------



## magicman2020

One point to add.....
I decided to conduct a Noise floor test. I had my Wife listen with the amp on and nothing playing. She was asking me "what's the point of this"? I asked her so what do you hear? 
My wife said , "nothing" !! thank you Honey.


----------



## A2029 (Oct 9, 2020)

magicman2020 said:


> One point to add.....
> I decided to conduct a Noise floor test. I had my Wife listen with the amp on and nothing playing. She was asking me "what's the point of this"? I asked her so what do you hear?
> My wife said , "nothing" !! thank you Honey.



Now you just have to convince her to sit for a while and listen to some of her favorite music  

I once heard a theory that women are more likely to enjoy listening to music if it is playing through speakers instead of headphones, and if done in social situations. Something about how evolutionarily when humans made music late in the evenings one aspect of musical enjoyment for women was the chance to wave their bodies around in tune with the musical flow. Men may become attracted to how well the woman could coordinate her movements along with the sound and the jiggling of body parts was also likely a big attractor


----------



## magicman2020

A2029 said:


> I once heard a theory that women are more likely to enjoy listening to music if it is playing through speakers instead of headphones, and if done in social situations. Something about how evolutionarily when humans made music late in the evenings one aspect of musical enjoyment for women was the chance to wave their bodies around in tune with the musical flow. Men may become attracted to how well the woman could coordinate her movements along with the sound and the jiggling of body parts was also likely a big attractor


*Burlesque Music _ great idea Mishca*
Excuse Me Honey. ....yes something new for you to listen too....oh nothing, Mischa recommended it.


----------



## magicman2020

I just showed the wife the thread . she got a big kick out of it. let the music begin


----------



## chrisdrop

First time using adapters today. AnM 6J7Gs. Dead silent and fully pleasing.  Thanks Mischa for coordinating w/ @Deyan so that my existing adapters would be wired correctly and work


----------



## Zachik

Glenn, Mischa and Dayan are all very bad for our wallets!!!


----------



## chrisdrop

Channeling @GDuss with 2x 1942 RCA 6C5s. 

It is hard to make the amp sound poorly I admit, but these are sounding pretty excellent...


----------



## GDuss

chrisdrop said:


> Channeling @GDuss with 2x 1942 RCA 6C5s.
> 
> It is hard to make the amp sound poorly I admit, but these are sounding pretty excellent...



Highly underrated tubes!!!


----------



## chrisdrop

FYI - I finally consolidated my notes and such into a more fulsome review of the Blue Halo here. I debated posting here, but the "reviews" may get more looks to get the Blue Halo in front of some more people. 

Cheers
Chris


----------



## chrisdrop

chrisdrop said:


> FYI - I finally consolidated my notes and such into a more fulsome review of the Blue Halo here. I debated posting here, but the "reviews" may get more looks to get the Blue Halo in front of some more people.
> 
> Cheers
> Chris


A first dual-driver roll. Adding C3Gs to 6C5Gs. So far, so good. The C3Gs straight away added some more space to the already pretty spacious Fivres. The C3Gs can get some minor metallic ring on occasion. I'll try to dampen them down with some tube dampers or some such. I should perhaps get another pair of C3Gs, maybe it is just mine.


----------



## chrisdrop

OK one more. Lots of listening today!! Another 1st go; 2x Phillips EL3N (inspired by chatter on the Glenn thread). These are nice today . They are dead silent and lovely inputs. With the adapters, they are TALL!


----------



## chrisdrop

These Visseaux 6N7GTs took a long time to settle in. I couldn't do it in one go. Left them overnight a few times, rotated them into listening etc. I could tell that if they kept opening they'd be nice. Really appreciative of them today.


----------



## chrisdrop

chrisdrop said:


> These Visseaux 6N7GTs took a long time to settle in. I couldn't do it in one go. Left them overnight a few times, rotated them into listening etc. I could tell that if they kept opening they'd be nice. Really appreciative of them today.


I guess it is clear what these tubes are for: Guerre:


----------



## magicman2020

@chrisdrop mentioned in one of his comparison impressions between the Blue Halo and Glenn OTL, that great tubes in the Glenn don't necessarily translate well into a Blue Halo and visa-versa. 
I have an interesting tube for your Blue Halo Amp collection. It's the Russian 6N6P. Up til now my favorite tube in a Blue Halo was the Tesla ECC88 6922's. Oddly enough the 6N6P is another 9-pin. Could it be that 9 pins just shine in a Blue Halo? I aim to find out. My next 9 pin will be the Tung Sol 5867. I'll let you know. 
Anyway back to the 6N6P. The most noticeable differences you can pick up on right away over the 6922s was the sound stage moved back substantially, therefore slightly less bright, deepened bass, enriched 3D effect. These truely are pleasure. Insert standard YMMV


----------



## Xcalibur255

I looked up the 5867 and it's used in industrial heating applications.    Just giving you a hard time of course.  

I've always liked the 5687 and think it sounds great in Glenn OTLs designed to use a single driver tube.  They seem to become just a hint lush and euphoric when subbing for a 6SN7 which is a sound that suits me just fine.  This family of "space" tubes seems to fly under a lot of radars which is interesting because they all sound very good.


----------



## chrisdrop

magicman2020 said:


> @chrisdrop mentioned in one of his comparison impressions between the Blue Halo and Glenn OTL, that great tubes in the Glenn don't necessarily translate well into a Blue Halo and visa-versa.
> I have an interesting tube for your Blue Halo Amp collection. It's the Russian 6N6P. Up til now my favorite tube in a Blue Halo was the Tesla ECC88 6922's. Oddly enough the 6N6P is another 9-pin. Could it be that 9 pins just shine in a Blue Halo? I aim to find out. My next 9 pin will be the Tung Sol 5867. I'll let you know.
> Anyway back to the 6N6P. The most noticeable differences you can pick up on right away over the 6922s was the sound stage moved back substantially, therefore slightly less bright, deepened bass, enriched 3D effect. These truely are pleasure. Insert standard YMMV


What are the characteristics of "little tubes" vs "big tubes". I am not sure if many general statements can really be made. I think Mischa mentioned that the little tubes are more linear? Perhaps my biases from the GOTL (which as still true _there_) are that older valves are better. Little tubes tend to be newer. Are there any other general characteristics of "little tubes"? I don't really have any of them, any adapters for them, etc. Perhaps it is time to get some? Tx for the inspiration @magicman2020.


----------



## Marutks

magicman2020 said:


> I have an interesting tube for your Blue Halo Amp collection. It's the Russian 6N6P. Up til now my favorite tube in a Blue Halo was the Tesla ECC88 6922's.



Do you run one ECC88 tube in 6J5 socket and one ECC88 tube in 6NS7 socket?

I have ordered the Blue Halo amplifier.   Perhaps I should get some adapters for ECC88 tubes.  They are much cheaper than NOS 6J5 tubes.


----------



## L0rdGwyn

Marutks said:


> They are much cheaper than NOS 6J5 tubes.



Depends on which ones!  The most sought after 6DJ8 tubes can be double or triple the cost of the most choice 6J5s.

Take these for example, Siemens CCa.  They are $700 on eBay  😯


----------



## chrisdrop

Marutks said:


> run one ECC88 tube in 6J5 socket and one ECC88 tube in 6NS7 socket?


I also thought that was very, very odd!


----------



## magicman2020

Marutks said:


> Do you run one ECC88 tube in 6J5 socket and one ECC88 tube in 6NS7 socket?


No,  I'm using a dual adapter in my 6J5's.


----------



## chrisdrop

magicman2020 said:


> No,  I'm using a dual adapter in my 6J5's.


Interesting idea


----------



## A2029

chrisdrop said:


> What are the characteristics of "little tubes" vs "big tubes". I am not sure if many general statements can really be made. I think Mischa mentioned that the little tubes are more linear? Perhaps my biases from the GOTL (which as still true _there_) are that older valves are better. Little tubes tend to be newer. Are there any other general characteristics of "little tubes"? I don't really have any of them, any adapters for them, etc. Perhaps it is time to get some? Tx for the inspiration @magicman2020.



Each tube has particular characteristics based on their internal construction (e.g. cathode-grid-plate spacing, and structure) and the materials used, such as plate and cathode metal composition. Some little tubes are thought to be quite non-linear, such as the 12AU7s as compared to the 6SN7, but other little tubes are thought to be very linear, such as the 6N6P/6H30P-DR or a triode strapped pentode such as the 12BY7. Difficulty in predicting which tube will sound best in a particular amp is that there is an interplay between the distortion produced by the amp circuitry and the distortion produced by the characteristics of the tube, such that you can get distortion cancellation or augmentation based on the combo. Whether distortion cancellation or augmentation is better for tonal quality is also likely somewhat subjective, so it really becomes a matter of rolling through tube types to find the best combos to suit to taste


----------



## magicman2020

So I guess the moral of this story is tube size doesn't matter.


----------



## Xcalibur255

Drilling down into this a bit more I have always found the debates between short and long plate or square and round plate to be very interesting.  Often tubes that have variation in plate length such as a 12AX7 you'll see the popular opinion that the ones with longer plates are better sounding.  I really wonder how much truth there is in that, or if it is more expectation bias.  Same with plate shape.  Round plate tubes often get characterized as having a more three dimensional soundstage than a ladder plate.  It begs the question of why these design variations even exist in the first place actually.  Maybe it was just to get around patents and had nothing to do with performance?

It will be quite a while before my upcoming amp is real and built but I have a fun experiment queued up along these lines ready to go.  I was able to get my hands on two pairs of 6J5G tubes:  both Raytheons (and I am decently confident Raytheon is the real manufacturer of both pairs), both manufactured in 1937, but one has round plates and the other ladder plates.  I'm very curious whether these tubes will sound the same or different in some way.


----------



## L0rdGwyn

Xcalibur255 said:


> Drilling down into this a bit more I have always found the debates between short and long plate or square and round plate to be very interesting.  Often tubes that have variation in plate length such as a 12AX7 you'll see the popular opinion that the ones with longer plates are better sounding.  I really wonder how much truth there is in that, or if it is more expectation bias.  Same with plate shape.  Round plate tubes often get characterized as having a more three dimensional soundstage than a ladder plate.  It begs the question of why these design variations even exist in the first place actually.  Maybe it was just to get around patents and had nothing to do with performance?
> 
> It will be quite a while before my upcoming amp is real and built but I have a fun experiment queued up along these lines ready to go.  I was able to get my hands on two pairs of 6J5G tubes:  both Raytheons (and I am decently confident Raytheon is the real manufacturer of both pairs), both manufactured in 1937, but one has round plates and the other ladder plates.  I'm very curious whether these tubes will sound the same or different in some way.



On this subject, I will say that at one time I did own two versions of the Tung-Sol 6SN7GT, the typical black glass round plate, and the very uncommon black glass ladder plate.  From memory, they sounded _very_ similar, despite the shapes of the plates being so different.


----------



## Zachik

L0rdGwyn said:


> On this subject, I will say that at one time I did own two versions of the Tung-Sol 6SN7GT, the typical black glass round plate, and the very uncommon black glass ladder plate.  From memory, they sounded _very_ similar, despite the shapes of the plates being so different.


I am surprised the round plate tube did not produce a more "well rounded up" sound...


----------



## L0rdGwyn

Zachik said:


> I am surprised the round plate tube did not produce a more "well rounded up" sound...



Good one, Zachi....LOL.


----------



## LoryWiv

Zachik said:


> I am surprised the round plate tube did not produce a more "well rounded up" sound...


Maybe you should "circle" back and listen again for that.


----------



## leftside

Marutks said:


> Do you run one ECC88 tube in 6J5 socket and one ECC88 tube in 6NS7 socket?
> 
> I have ordered the Blue Halo amplifier.   Perhaps I should get some adapters for ECC88 tubes.  They are much cheaper than NOS 6J5 tubes.


I've been buying ECC88 and related for my new preamp. Some of these are very expensive.
http://www.audiotubes.com/6dj8.htm




L0rdGwyn said:


> Depends on which ones!  The most sought after 6DJ8 tubes can be double or triple the cost of the most choice 6J5s.
> 
> Take these for example, Siemens CCa.  They are $700 on eBay  😯


Beat me to it. 



Xcalibur255 said:


> Drilling down into this a bit more I have always found the debates between short and long plate or square and round plate to be very interesting.  Often tubes that have variation in plate length such as a 12AX7 you'll see the popular opinion that the ones with longer plates are better sounding.  I really wonder how much truth there is in that, or if it is more expectation bias.  Same with plate shape.  Round plate tubes often get characterized as having a more three dimensional soundstage than a ladder plate.  It begs the question of why these design variations even exist in the first place actually.  Maybe it was just to get around patents and had nothing to do with performance?


I use 12AX7 in my main amps and previous preamp. I definitely prefer the long black plate tubes. RCA, Mullard, Telefunken, etc. Early Mullard are more revealing like GEC tubes from the same era. From 1958 onwards they are a little warmer. Anyone got any spare 1953 Mullard 12AX7? Check out the price on eBay the last pair sold for. Singles are rare as hens teeth, let alone matching pairs.

You can still pick up plenty of 6J5 tubes with early construction - i.e. metal base, black plates, foil or D getters for reasonable prices. Check out the equivalent early 6SN7 prices.


----------



## Xcalibur255

@leftside 

Have you tried the new production Gold Lion B759?  I'm running these in my Luxman SQ-N150 and they stand toe to toe with the Sylvania Gold Brand 5751s that were in there before. They're a bit more linear than the Sylvanias, not quite as "honey dipped" in that lovely way the best Sylvanias are, but they do absolutely nothing wrong tonally and on a technical level I think they actually beat the Sylvanias.  I've been quite impressed.


----------



## leftside

Xcalibur255 said:


> @leftside
> 
> Have you tried the new production Gold Lion B759?  I'm running these in my Luxman SQ-N150 and they stand toe to toe with the Sylvania Gold Brand 5751s that were in there before. They're a bit more linear than the Sylvanias, not quite as "honey dipped" in that lovely way the best Sylvanias are, but they do absolutely nothing wrong tonally and on a technical level I think they actually beat the Sylvanias.  I've been quite impressed.


Indeed I have. They came with both my Mac amps and Mac preamp. Best new production tubes out there imo. I'm selling my Mac preamp this weekend with 4 Gold Lion B759/12AX7 in the line stage and 4 B759/12AX7 in the phono stages.


----------



## chrisdrop

Wishing all of you 1101 Audio fans a very Merry Christmas. May your amps be forever tube-driven!


----------



## UntilThen

Merry Christmas all. May 2021 see a new super tube amp here.


----------



## A2029

Merry Christmas everyone!! Wishing you health and happiness through the holidays and into 2021!!!


----------



## LoryWiv

Zachik said:


> I am surprised the round plate tube did not produce a more "well rounded up" sound...


Right, and the ladder plate had "elevated" top end!


----------



## chrisdrop

Quiet over here...

Pair of KenRad 76s that I've been enjoying in my other amp, also lovely in the BH today.


----------



## UntilThen

^^ Nice. I'm waiting to see how @Xcalibur255 's KT150 or @leftside next EL34 turn out. There will be one last amp for me in 9 months time and I've started looking around.

Will be culling some of my amps in the next 3 months.


----------



## Xcalibur255 (Jan 11, 2021)

It's a shame the two amps won't ever be in the same room at the same time.  A fun experiment would be to make a direct comparison of leftside and my builds with my build operating in the EL34 output mode.  Both amps would be 6J5 >>> EL34.  In theory a lot of the difference in sound would be coming from the difference in the output transformers, along with some small details.  It would be interesting to see just how different the sound ends up being between two different brands of OPT.

I can't remember if leftside asked for a tube rectifier though, if that's present it would be a significant contributor to any difference as well.


----------



## UntilThen

Would be even more interesting comparing your KT150 build with Leftside's EL34, Glenn 300b and his other super monster 6as7g / 5998 build. Not apples to apples comparison but interesting none the less. You probably need 3 pairs of ears to verify results but of course you may / will get 3 different answers. 

Not forgetting your Glenn 45 build


----------



## Xcalibur255

UntilThen said:


> Would be even more interesting comparing your KT150 build with Leftside's EL34, Glenn 300b and his other super monster 6as7g / 5998 build. Not apples to apples comparison but interesting none the less. You probably need 3 pairs of ears to verify results but of course you may / will get 3 different answers.
> 
> Not forgetting your Glenn 45 build



Sadly the Glenn 45 is sick again.  I've never been able to figure out why it sounds good sometimes and other times does not.  I won't give up on it though.  It's a "for the future" project at the moment.


----------



## leftside

No rectifier for me in this amp. I have rectifiers in my preamp and DAC though.

2 * EL34 (and a whole bunch of other related power tubes can be used, as Mischa has come up with a clever design), 2 * 6J5, 1 * 6SN7 and an impedance selector for different headphones. Custom transformers from Sowter - wait time for the transformers is 2 - 4 months.


----------



## Xcalibur255

Yeah I think it took Keenan a good while to get his transformers from Sowter as well.


----------



## L0rdGwyn

I was told by Martin at Sowter that they are bringing on new staff for 2021, they are hoping to clear their backlog, so the wait times should go down.


----------



## UntilThen

leftside said:


> No rectifier for me in this amp. I have rectifiers in my preamp and DAC though.
> 
> 2 * EL34 (and a whole bunch of other related power tubes can be used, as Mischa has come up with a clever design), 2 * 6J5, 1 * 6SN7 and an impedance selector for different headphones. Custom transformers from Sowter - wait time for the transformers is 2 - 4 months.


I’m for simplicity. That configuration is good and will look neat. Problem is getting 6J5 tubes if you’re starting now. Or are there still plenty of good ones.

Auris Nirvana use one ECC82 to 2 * EL34 and I really love the tone of LCD4 from that amp with Qutest.


----------



## leftside

UntilThen said:


> I’m for simplicity. That configuration is good and will look neat. Problem is getting 6J5 tubes if you’re starting now. Or are there still plenty of good ones.


I have a couple of 6J5 tubes. They still seem plentiful.


----------



## Xcalibur255

UntilThen said:


> I’m for simplicity. That configuration is good and will look neat. Problem is getting 6J5 tubes if you’re starting now. Or are there still plenty of good ones.
> 
> Auris Nirvana use one ECC82 to 2 * EL34 and I really love the tone of LCD4 from that amp with Qutest.



If you're an eBay shopper they kind of come and go in waves in my experience.  I was able to buy just about every brand and plate style I was interested in trying within the space of a month, but the couple of months before and after there were no listing that caught my eye.  Just keep an eye out and some good ones will come along.

One other tact would be to just grab a pair of the L63 straight glass from Langrex and wait until after you have an amp to hunt down the rest.  You would be starting out with one of the best and they're readily obtainable.


----------



## UntilThen

Xcalibur255 said:


> If you're an eBay shopper they kind of come and go in waves in my experience.  I was able to buy just about every brand and plate style I was interested in trying within the space of a month, but the couple of months before and after there were no listing that caught my eye.  Just keep an eye out and some good ones will come along.
> 
> One other tact would be to just grab a pair of the L63 straight glass from Langrex and wait until after you have an amp to hunt down the rest.  You would be starting out with one of the best and they're readily obtainable.



I did have a pair of straight glass Gec L63 from Langrex but I gave it away when I sold off GOTL.

I’m very fussy when it comes to tubes. They have to be in tip top shape. Very new preferably. So that could be where it’s difficult to find 6J5.

By very new tubes I mean these.... @leftside get your wallet ready  

https://www.ebay.co.uk/itm/265013952551

https://www.ebay.co.uk/itm/KT66-GEC-MATCHED-QUAD-NOS-BOXED-VALVE-TUBE-LC60/274647163383

https://www.ebay.co.uk/itm/KT66-GEC-NOS-BOXED-MATCHED-PAIR-VALVE-TUBE-LC1/265013882340

https://www.ebay.co.uk/itm/265013952551



leftside said:


> I have a couple of 6J5 tubes. They still seem plentiful.



I want your address. I'm coming whether invited or not.


----------



## Galapac

UntilThen said:


> By very new tubes I mean these.... @leftside get your wallet ready
> 
> https://www.ebay.co.uk/itm/265013952551?ViewItem=&item=265013952551&category=0&ssPageName=ADME:B:SEMK:UK:SHOWI&emailtemplateid=145307560&sellerid=FpRekKD1aqAWsCi2/SAKqA==&buyerid=OT1C29eGPzQ qD9nQ2vYrw==&refid=store
> 
> ...


Easy now...don't hoard all the tubes @UntilThen, save some for the rest of us.


----------



## A2029 (Jan 15, 2021)

UntilThen said:


> By very new tubes I mean these.... @leftside get your wallet ready
> 
> https://www.ebay.co.uk/itm/265013952551
> 
> ...



 **wallet screams in fear


----------



## chrisdrop

Whilst the group here on head-fi has run up the demand on 6J5 & friends, there is pretty wide availability still.


----------



## UntilThen

Galapac said:


> Easy now...don't hoard all the tubes @UntilThen, save some for the rest of us.



They are all yours. I'm not buying those. 2000 pounds won't get me the amp I've in mind but it's half way there.   

Strangely I'm really intrigued by solid states at the moment.... or a godzilla EL34, KT66 transfo couple amp or the improved smurf. Although just thinking of the Auris Nirvana and how it moved me (sonically and bodily), I think a step in the godzilla direction sounds very exciting.

The solid states are Benchmark HPA4 or Niimbus US 4.



chrisdrop said:


> Whilst the group here on head-fi has run up the demand on 6J5 & friends, there is pretty wide availability still.



Good to know Chris. But phantoms are watching as we speak.


----------



## leftside

I wouldn't touch those later clear glass double ring getter KT66:
https://jacmusic.com/nos/images/Fakes/index.html

Stick to the late 60's or earlier versions. For some reason these seem to be much rarer.... (see above).

However, Langrex did have 10 Osram metal base L63 for sale last night for 125 GBP each. But it looks like they all sold!!
https://www.ebay.com/itm/L63-6J5G-VINTAGE-OSRAM-METAL-BASE-NOS-BOXED-VALVE-TUBE-LC93/274647215601

I wonder if this person is on headfi?







m***3
	

	
	
		
		

		
		
	


	




( 290
	

	
	
		
		

		
		
	


	




)​


----------



## UntilThen

Yes I saw the L63 metal glass just one left but next moment I look, it's gone ! 

It's not easy to get the earlier version of KT66 anymore, especially new ones.

So @datka3  welcome to this 1101-audio thread. This is the thread where progressive custom tube amps are made by the very talented mischa. He's qualified in other disciplines so I'm not sure why he's creating tube amps, maybe just his passion.  

Now you've heard the Bartok and own Dave and still want an equivalent nice tube amp, perhaps have a look here. I could refer you to Woo Audio Wa33 or the Auris Nirvana but here is where people have owned lovely HiFi gear, also talk about their custom tube amps. 2 amps are on the horizon. One is Xcalibur KT150 version and Leftside's EL34, Kt66 variant. The choice is wide here and elsewhere but it's starting to get interesting here. I'm not sure why I keep repeating 'here' but that's an omen. 

2 setups have left a mark on me. They are:-

Woo Audio Wa33 > HiFiMan Susvara. Heard this combination only once at the HiFi show but it's an unforgettable experience.

Qutest > Auris Nirvana > Audeze LCD-4. This is classic creamy and at the same time very clear EL34 tone combined with the gorgeous LCD-4 at it's best. 

Now, Leftside has 2 custom tube amps that he has. I've no doubt he's getting similar experience with his LCD-4 and Stellia. However it's the next 2 amps being built here that I'm watching with interest. The KT150 and EL34 version. 

So stay awhile and ask questions.


----------



## Xcalibur255

I'm not worried about 6J5 availability, but I am worried about price.  I think we're going to see a fairly steady climb from here on out as more people become aware of them as a 6SN7 alternative.

That said the metal can ones are still dirt cheap and are going to stay that way because they're not "cool" so the value proposition is only limited by how fussy we decide to be.  Not being able to see the internal construction is a little frustrating but you're only risking $10.


----------



## mordy

leftside said:


> I wouldn't touch those later clear glass double ring getter KT66:
> https://jacmusic.com/nos/images/Fakes/index.html
> 
> Stick to the late 60's or earlier versions. For some reason these seem to be much rarer.... (see above).
> ...


----------



## UntilThen

Hahaha @mordy , US4299 for that pair. I rather be a celibate lol.



Xcalibur255 said:


> I'm not worried about 6J5 availability, but I am worried about price.



That's right. With demand, so will the price go up. I'm on my precious pair of Tung Sol 5998 now with less than 200 hours. Bought new from Vietnam 4 years ago. It arrived brand new in a tupperware box with shiny pins. It's so quiet I can hear my own breathing with no music playing.

The pair on the left with green letterings. New pair from Woo Audio cost US$900.


----------



## Xcalibur255

5998 prices are crazy now.  Knowing 90% of them get used in amps that bias them poorly breaks my heart a little too.  1/2 of the pair I use in my GOTL is still from the original set that blasted the right side driver in my K701 straight through the plastic slots in it's ear cup.  The things we put up with for the tubes we love.......


----------



## UntilThen

Xcalibur255 said:


> 5998 prices are crazy now.  Knowing 90% of them get used in amps that bias them poorly breaks my heart a little too.  1/2 of the pair I use in my GOTL is still from the original set that blasted the right side driver in my K701 straight through the plastic slots in it's ear cup.  The things we put up with for the tubes we love.......



You know you have bad luck with 5998. Sometimes people have a bad experience with something and it puts them off. 

Here's an example. Friend of mine has been through lots of gear. He had a Cayin HA300 but it played up right from the beginning. Hum, whistles and pops. Took it back to the shop to be fixed. Came back happen again. Returned it finally. Then when I told him about Auris Nirvana, he got that too ! It came with the separate power supply in a wooden enclosure just like the main amp. But on getting it home, the power supply fail ! Change fuse but it leads to other problems. In the ends return it and swap for a Mogwai Se and now he's happy. Now those are unfortunate and frightening experience. The Auris Nirvana that I heard with LCD-4 is gorgeous but if I had such an experience as him, I would be put off completely, especially for a AUD $10,000 amp.


----------



## Galapac

UntilThen said:


> That's right. With demand, so will the price go up. I'm on my precious pair of Tung Sol 5998 now with less than 200 hours. Bought new from Vietnam 4 years ago. It arrived brand new in a tupperware box with shiny pins. It's so quiet I can hear my own breathing with no music playing.
> 
> The pair on the left with green letterings. New pair from Woo Audio cost US$900.


Yes but did you reuse the Tupperware for food? I’m kidding of course, no need to answer.


----------



## UntilThen

Galapac said:


> Yes but did you reuse the Tupperware for food? I’m kidding of course, no need to answer.



There was an unfortunate story to the 5998 though. After the seller send the tubes to me, he told me the 5998 tubes were left behind by the US military in the Fall of Saigon..... 

How they are use in the military I don't know. As for the tupperware, I bin it. It is new but I'm not taking a chance.


----------



## LoryWiv

UntilThen said:


> By very new tubes I mean these.... @leftside get your wallet ready
> 
> https://www.ebay.co.uk/itm/265013952551?ViewItem=&item=265013952551&category=0&ssPageName=ADME:B:SEMK:UK:SHOWI&emailtemplateid=145307560&sellerid=FpRekKD1aqAWsCi2/SAKqA==&buyerid=OT1C29eGPzQ qD9nQ2vYrw==&refid=store
> 
> ...


That's a bit discouraging @UntilThen. I've been hunting for a pair of GEC KT88's for over a year and can't find any in good condition (ideally NOS) that aren't  selling for my than my first car. The hunt continues!


----------



## UntilThen

Speaking of GEC KT88, I once had a contact who was going to sell me a bunch of Marconi KT66 and KT88 but somehow I have forgotten about him or his details ! When I got Oblivion amp by Ultransonic Studio, I thought I have given up tubes. 

I believe he wanted AUD$2000 for these quad of GEC KT88 - which I would be ok if I was really going into an amp using KT88 but you know you can get Gold Lion KT88 for much cheaper but it's not the same.


----------



## LoryWiv

UntilThen said:


> Speaking of GEC KT88, I once had a contact who was going to sell me a bunch of Marconi KT66 and KT88 but somehow I have forgotten about him or his details ! When I got Oblivion amp by Ultransonic Studio, I thought I have given up tubes.
> 
> I believe he wanted AUD$2000 for these quad of GEC KT88 - which I would be ok if I was really going into an amp using KT88 but you know you can get Gold Lion KT88 for much cheaper but it's not the same.


I have the new production Gold Lions and actually enjoy them in Elise very much, in deed that's what intrigues me to try to OG GEC! Live leads welcomed!!!


----------



## UntilThen

Too much going on at work and in my head-fi life. I have to try and hunt down that contact now. I believe I bought a single GEC 6as7g from him.

Would you believe it, what's rocking my boat is now a very odd setup:-

Questyle CMA Twelve (using as dac - ak4490 ds chipset) > SMSL SP200 > He1000se. This is the reason I'm interested in buying the Benchmark HPA4. I believe my Yggdrasil into HPA4 and Hekse would be stunning but I'm still interested in one final last tube amp.


----------



## Xcalibur255

UntilThen said:


> There was an unfortunate story to the 5998 though. After the seller send the tubes to me, he told me the 5998 tubes were left behind by the US military in the Fall of Saigon.....
> 
> How they are use in the military I don't know. As for the tupperware, I bin it. It is new but I'm not taking a chance.


Their most common job as voltage regulators were in the computers of the era.


----------



## UntilThen

Xcalibur255 said:


> Their most common job as voltage regulators were in the computers of the era.



I was on British ICL computers in the late 70s before moving on to IBM. I've not come across the 5998 being used in computers but it probably predates that - like in the 60s. !


----------



## Xcalibur255

Some 5998 are actually labeled IBM for this exact reason.


----------



## UntilThen

I've seen 5998a that are labelled IBM but not 5998 and we do know those are 2 entirely different tubes. Heard both and the 5998a is not fit for my ears consumption.


----------



## Xcalibur255

There are domino plate 5998s with the IBM labeling too.  I had forgotten the 5998A even existed.


----------



## UntilThen

In another development, Elon Mask twittered buy 'Signal Advance' and shares in that medical company rose 11,708 per cent in just 3 days. What the investors didn't realise was that Elon was actually saying use 'Signal' in response to using Whatsapp. 

Difference in 5998 and 5998a could have disastrous effect lol. 

Just kidding but developments these days are astonishing. The world we live in....


----------



## leftside

LoryWiv said:


> That's a bit discouraging @UntilThen. I've been hunting for a pair of GEC KT88's for over a year and can't find any in good condition (ideally NOS) that aren't  selling for my than my first car. The hunt continues!


KT88 in good condition are harder to find than KT66 in good condition. NOS very rarely come up for sale. The fading/browning getter flashing on the sides give those away as being well used. And if they came up for sale and you purchased them, would you use them? I'd feel guilty. This is why I prefer lightly used tubes. TT21 (with adapters) is an alternative, but those are getting pricey these days as well. Luckily the new production Gold Lion are very good!

The ones that UntilThen showed are from the 1970's, so not as desirable as the ones from the 1950's, but they do indeed look NOS. 

Did you know, the very first version KT88 had a brown base and different shaped glass. Good luck finding those


----------



## UntilThen (Jan 15, 2021)

Leftside has all those that's why I'm going to Canada once restrictions are lifted.

GEC TT21 are still available but please DON'T buy it all. Leave some for me !!!
https://www.ebay.com.au/itm/GEC-TT2...e-also-available-in-pairs-quads-/203075264809

Omg those are in Australia. Hands off everyone.

Ummmm light bulb moment. @Xcalibur255  what do you think of using GEC TT21 in the build? I think it will sound gorgeous.


----------



## Xcalibur255

They seem to be rare and expensive.  One of the design goals for the amp was that it not be crazy expensive to tube and re-tube while still sounding great.  I also like the power output I'm going to be able to get from the KT150.  It's pretty hard to get above 10 watts single-ended without doing crazy voltages and stuff like the 211 or 840 which was a league above where I wanted to go.


----------



## LoryWiv

I currently have Feliks-Audio Elise although follow this thread with interest as I plot my future . Question: Will my 6L6 / KT88 adapters (from @Deyan ) --> allow me to use TT21 in Elise or do I need different adapters, anode cap etc...


----------



## maxpudding

I have an upcoming amp from Mischa as well, I asked Mischa to build me an OTL amp that would run on 6AS7Gs, with the 6J5Gs or 6SN7. Because the BH was originally designed to operate without power tubes, I also asked him if he could incorporate a switch to change the operational mode of the amp (with or without distortion from power tubes). He came back after a few days and told me he could install a bypass circuitry with a switch, and it would be a complicated build. He probably should patent it 😆

Mischa is a great guy, and a talented amp builder, can’t wait to see his creations here in the upcoming months and years.


----------



## UntilThen

What’s that mean with or without distortions on power tubes. What would that do. Just trying to understand from a layman’s perspective.


----------



## maxpudding

UntilThen said:


> What’s that mean with or without distortions on power tubes. What would that do. Just trying to understand from a layman’s perspective.



Basically it means to turn the power tubes on or off that’s all 😂 but to do that simple operation would still require a complicated circuitry due to the supercharger in the amp that can’t be turned off.


----------



## Xcalibur255

If the supercharger portion of the circuit acts as a gain stage or has gain of its own then such a switch would allow the amp to operate in a solid state mode if desired.  That's the way I interpret it anyway, maybe I'm wrong.


----------



## Galapac (Jan 15, 2021)

Xcalibur255 said:


> If the supercharger portion of the circuit acts as a gain stage or has gain of its own then such a switch would allow the amp to operate in a solid state mode if desired.  That's the way I interpret it anyway, maybe I'm wrong.


🤔 That would be very cool, 2 different amps in one. Like a distortion pedal effect on a guitar.


----------



## A2029

Xcalibur255 said:


> If the supercharger portion of the circuit acts as a gain stage or has gain of its own then such a switch would allow the amp to operate in a solid state mode if desired.  That's the way I interpret it anyway, maybe I'm wrong.



Not quite, the supercharger essentially works in tandem with the tube by pulling a constant current as a sink. It has no gain of its own and if working properly pulls a constant current no matter what voltage is at the tube anode, such that the tube fully determines the voltage swing that occurs at the anode. The voltage at the tube anode is determined by a constant current source that keeps approx 6.2mA passing through the tube.


----------



## leftside

LoryWiv said:


> I currently have Feliks-Audio Elise although follow this thread with interest as I plot my future . Question: Will my 6L6 / KT88 adapters (from @Deyan ) --> allow me to use TT21 in Elise or do I need different adapters, anode cap etc...


Not quite sure I know what you mean. I have TT21 to KT88 adapters for my Mac amps. I definitely can't use 6L6 with those amps.



maxpudding said:


> I have an upcoming amp from Mischa as well, I asked Mischa to build me an OTL amp that would run on 6AS7Gs, with the 6J5Gs or 6SN7. Because the BH was originally designed to operate without power tubes, I also asked him if he could incorporate a switch to change the operational mode of the amp (with or without distortion from power tubes). He came back after a few days and told me he could install a bypass circuitry with a switch, and it would be a complicated build. He probably should patent it 😆
> 
> Mischa is a great guy, and a talented amp builder, can’t wait to see his creations here in the upcoming months and years.


I'm very happy with my OTL amp from Mischa using 6AS7G and 6J5 or 6SN7. I think having the 6SN7 socket is still nice to have, as it allows you to use ECC32 and ECC33 and a whole bunch of other tubes with adapters (and of course 6SN7!). I also have a 6080/5998 switch that you might want to consider.


----------



## Zachik

maxpudding said:


> Mischa is a great guy, and a talented amp builder, can’t wait to see his creations here in the upcoming months and years.


I have corresponded with Mischa a few months ago, and agree he's a great guy and very knowledgeable! Good chance my next amp, once I decide what I want, will be commissioned to him 
I have 2 tube amps built by Glenn (GOTL and 6EL3N) which I love.  Glenn is also a great guy, but he seems to be buried deep in build commitments so the wait is extra long...


----------



## maxpudding (Jan 16, 2021)

leftside said:


> I'm very happy with my OTL amp from Mischa using 6AS7G and 6J5 or 6SN7. I think having the 6SN7 socket is still nice to have, as it allows you to use ECC32 and ECC33 and a whole bunch of other tubes with adapters (and of course 6SN7!). I also have a 6080/5998 switch that you might want to consider.



Your amp is the inspiration for this upcoming amp of mine 😉

I am not sure about the power tube selector switch, but I did mention to him that I want to run 6x6BX7 tubes, or 4/2 x 6080/5998/6AS7G.

edit: I’d like to think it’s a smaller version of your amp 😊


----------



## LoryWiv

leftside said:


> _Not quite sure I know what you mean. I have _*TT21 to KT88*_ adapters for my Mac amps. I definitely can't use 6L6 with those amps._
> 
> I'm very happy with my OTL amp from Mischa using 6AS7G and 6J5 or 6SN7. I think having the 6SN7 socket is still nice to have, as it allows you to use *ECC32* and ECC33 and a whole bunch of other tubes with adapters (and of course 6SN7!). I also have a 6080/5998 switch that you might want to consider.



Noted, thanks. Do the TT21 adapters require a wire from base to anode cap?

I thought ECC32 primary difference is higher heater current, and they could be used in 6SN7 socket w/o adapter, correct?

Thanks for helping me learn how to roll without blowing up my amp!!!


----------



## cdanguyen08

I've been lurking this thread for awhile. I first PMed @A2029 last year about the Blue Halo amp but decided to hold off till I move back to the states. Then a few days ago I asked Mischa about making a build similar to @Zachik. Happy to say I've put my deposit down for a KT150 amp like @Xcalibur255  and a bit of inspiration from @leftside  build as well.  Mischa has been very patient with my questions and helpful in explaining the many options as I am new to tube amps. Now to go down this rabbit hole of buying tubes!


----------



## UntilThen

I just came back from https://www.minidisc.com.au/ to collect my LCD-3f. Totally renewed. Very pleased with new headband and new earpads and new yoke.

While there I ask to audition Susvara with Chord Hugo TT 2 and M'Scaler. As expected it's a neutral, transparent tone, full of details and clarity. Not as bright as SMSL SP200 of course. Up the volume and it can go loud but it does not move me. I think I am too used to the organic 3D tone of tube amps.



Then I had the Auris Nirvana added to the mix. So :-
Chord Hugo TT2 (AUD$8500) + M'Scaler (AUd$7500) > Auris Nirvana (AUD $9299) > HiFiMan Susvara (AUD $7499).

Now it's a lovely organic 3D tone but with so much details and clarity. I could totally love Susvara in this setup but that's a total cost of AUD $32,800. I don't think I'll forget this 2 hours audition. It's a dream. All items in this setup is pure class in build and SQ. Seriously this is end game for me.


Having said that, I actually prefer what I heard in the shop 3 weeks ago. Qutest > Auris Nirvana > LCD-4. Perhaps not as detailed as the above but the visceral impact is there due to LCD-4. Susvara is lighter in tone but can still kick the heck out of kick drums but just not as hard as LCD-4. However tonally Susvara is like a group of angels singing. I'm moved with this setup.

So out of this, I realise that I like a tube amp that runs on EL34 and not out straight from Hugo TT2 + M'Scaler. My opinion of course. I have not heard one with KT88 or KT150 and if I did, I might like that too. So will see how Xcalibur and Leftside amps turn out to be and impressions. I have Yggdrasil and He1000se. Get another LCD-4 and another EL34 transformer coupled tube amp and I'm set plus I get to keep the Schiit Moljnir 2 and Violectric v280 and La Figaro 339i and Woo Audio Wa22 and Oblivion.


----------



## UntilThen

It's kind of strange. This AUD $5300 setup consisting of Questyle CMA Twelve + Audeze LCD-3f has me tapping my feet too. I'll forget the $33,000 system above and just enjoy this and retain my golf membership.


----------



## whirlwind

I can't wait to see @leftside  amp when it is completed.  I am a huge fan of the EL34 tube and now that he has a dictionary of info on that tube...this is going to be fun.
I often wonder what the EL34 tube sounds like when being pushed a little bit harder than the 250 volts that mine are...but then I think, the tubes should last longer and there should be less distortion at 250 volts.

Regardless, these tubes sound great and I am excited to see this amp.


----------



## UntilThen

EL34 on Auris Nirvana sound so smooth and yet powerful and forceful. Having heard that, I don't think I need to use my EL12 spez anymore. 

Likewise I'm waiting to see Leftside's forthcoming EL34 amp. I have a feeling it's going to be just great - or sensational.  Of course all eyes will be on Mischa because he's the creator.


----------



## UntilThen (Jan 16, 2021)

After hearing the end game system today, I decided to buy these 3 amps from the shop so I can run them in series or parallel. Need to think outside the box, right @UsoppNoKami @bcowen  ?


----------



## bcowen

UntilThen said:


> After hearing the end game system today, I decided to buy these 3 amps from the shop so I can run them in series or parallel. Need to think outside the box, right @UsoppNoKami @bcowen  ?



I don't see even a hint of a tube in there.  Fail.


----------



## Zachik

bcowen said:


> I don't see even a hint of a tube in there.  Fail.


UT has switched to the dark side   
What's next? Beats headphones?


----------



## UntilThen

bcowen said:


> I don't see even a hint of a tube in there.  Fail.



Not everything in life requires tubes. Do you have tubes in your 4k TV?   



Zachik said:


> UT has switched to the dark side
> What's next? Beats headphones?



I'm buying over Beats and revamping the whole lineup. It will sound great with Beat It.


----------



## leftside

maxpudding said:


> Your amp is the inspiration for this upcoming amp of mine 😉
> 
> I am not sure about the power tube selector switch, but I did mention to him that I want to run 6x6BX7 tubes, or 4/2 x 6080/5998/6AS7G.
> 
> edit: I’d like to think it’s a smaller version of your amp 😊


This is the amp that Mischa wanted to build for me! I insisted on six 5998/6080/6AS7G power tubes, and Mischa said "but that is going to require a ridiculous power supply" I said "yes I know" 



LoryWiv said:


> Noted, thanks. Do the TT21 adapters require a wire from base to anode cap?
> 
> I thought ECC32 primary difference is higher heater current, and they could be used in 6SN7 socket w/o adapter, correct?
> 
> Thanks for helping me learn how to roll without blowing up my amp!!!


Yes TT21 adapters require a wire from base to anode cap. No adapter required for ECC32.



UntilThen said:


> EL34 on Auris Nirvana sound so smooth and yet powerful and forceful. Having heard that, I don't think I need to use my EL12 spez anymore.


I'm looking forward to using EL12 and spez with this amp! Already have the adapters and am using the tubes in my DAC and preamp.

There is a great seller in the US who I've purchased from before who is selling GEC KT88. I just grabbed a pair as they are a very early version. First version and first year (N) with that glass shape, and the single getter at the top. Later 1950's versions have the 3 getters (two at the side and one at the top). He also has another pair with the single getter at the top and only 2 years newer.
https://www.usaudiomart.com/details/649695132-original-genalex-kt-88s-4


----------



## UntilThen (Jan 16, 2021)

leftside said:


> I'm looking forward to using EL12 and spez with this amp! Already have the adapters and am using the tubes in my DAC and preamp.



Do you mind posting a very nice picture of the EL12 spez with the adapters on your dac? I want to see if the adapter is nice and worthy of getting. I'm OCD and adapters or anything has to be near perfect.  So far I think Woo Audio adapters are ok... or more than ok. Those from china are just so ..... well what can I say. I try to blindfold myself when using them.

You have just make me very keen to see the outcome of your amp now. If I can run EL34 and EL12 spez or EL11 or EL12 or EL12n on that amp then that's sufficient. Problem is adapters kills me. Unless Mischa can get a multi-function tube socket for EL34 and EL12 haha.... please tell me it's possible.


----------



## leftside

UntilThen said:


> Do you mind posting a very nice picture of the EL12 spez with the adapters on your dac? I want to see if the adapter is nice and worthy of getting. I'm OCD and adapters or anything has to be near perfect.  So far I think Woo Audio adapters are ok... or more than ok. Those from china are just so ..... well what can I say. I try to blindfold myself when using them.


Will do. Just got back from a ride, so need to clean the bike and all the muddy gear first (mid winter here). These are white Chinese adapters.


----------



## UntilThen

leftside said:


> Will do. Just got back from a ride, so need to clean the bike and all the muddy gear first (mid winter here). These are white Chinese adapters.



You're living dangerously. I just play golf and get @bcowen to drive my golf cart without it going into the lake. That's excitement.

Is this motorbike or bicycle? I mean the rugged kind. I was into those at one time. These days I just do cross country free fall skiing.


----------



## LoryWiv

leftside said:


> This is the amp that Mischa wanted to build for me! I insisted on six 5998/6080/6AS7G power tubes, and Mischa said "but that is going to require a ridiculous power supply" I said "yes I know"
> 
> 
> Yes TT21 adapters require a wire from base to anode cap. No adapter required for ECC32.
> ...


@leftside, thank you so much! His KT88 price seems reasonable if they are in good condition, may go for it myself!


----------



## UntilThen (Jan 16, 2021)

There are a lot on ebay but just so expensive. I will stick with vanilla EL34 and my Telefunken EL12 spez. 

Look at this outrageous price for a quad of GEC KT88.
https://www.ebay.com/itm/Vintage-1960s-Matched-GEC-KT88-Tubes-Quad-Set/284124923433

Found a very nice 6J5 for a reasonable price
https://www.ebay.com/itm/Mullard-6J...rsOtherItemsV2&_trksid=p2047675.c100047.m2108


----------



## mordy

Xcalibur255 said:


> Their most common job as voltage regulators were in the computers of the era.


The thing is that several others reported 5998 tubes arcing and causing damage- one well known designer will not go near them....


----------



## UntilThen

mordy said:


> The thing is that several others reported 5998 tubes arcing and causing damage- one well known designer will not go near them....



Several bad experiences with 5998 does not make them bad. Many on the La Figaro 339 and Crack BH thread have use them and are still using them with no issues. My pair have been working like a charm since 2017. Any tube can go bad. 5998 is no exception or more prone.


----------



## mordy

UntilThen said:


> Several bad experiences with 5998 does not make them bad. Many on the La Figaro 339 and Crack BH thread have use them and are still using them with no issues. My pair have been working like a charm since 2017. Any tube can go bad. 5998 is no exception or more prone.


I do have two 5998 tubes and never had a problem - just reporting what I read.
One of my 5998 tubes was made for IBM - if there are lots of 3s and 9s in the numbers on the base of the tube it was made for IBM:




This tube was made by Tung Sol in 1961.


----------



## bcowen

UntilThen said:


> Not everything in life requires tubes.



Yes it does.


----------



## UntilThen (Jan 16, 2021)

bcowen said:


> Yes it does.



Tell me about it. For 30 mins, I was trying to get the tubes out of my Mjolnir 2 - without adapters and I couldn't. Mjolnir is Thor's hammer in the mythology. Such is my frustration I want to use Thor's hammer and smash this amp.

But a light bulb moment - I put some scrotch tape and wrap it around the tube and wiggle and pull it up. Relief ! See what tubes does to me.

So now I make sure I use the socket savers as it raise the tubes for my fingers to pull it up. And I found a 5 pack of RCA 6BQ7A / 6BZ7 tubes and these replace the Amperex Orange globes.... I must say it's now no longer Thor's hammer but his crown. 

So Mjolnir 2 has replaced Ragnarok who I so savagely sold off. Such is my affinity with tubes that anything that doesn't have tubes will be sold off !

Mjolnir 2 with Yggdrasil - perfect !

Only problem is I need bigger tubes in Mjolnir 2. Can I roll in a EL34 @bcowen  ?


----------



## bcowen

UntilThen said:


> Tell me about it. For 30 mins, I was trying to get the tubes out of my Mjolnir 2 - without adapters and I couldn't. Mjolnir is Thor's hammer in the mythology. Such is my frustration I want to use Thor's hammer and smash this amp.
> 
> But a light bulb moment - I put some scrotch tape and wrap it around the tube and wiggle and pull it up. Relief ! See what tubes does to me.
> 
> So now I make sure I use the socket savers as it raise the tubes for my fingers to pull it up. And I found a 5 pack of RCA 6BQ7A / 6BZ7 tubes and these replace the Amperex Orange globes.... I must say it's now no longer Thor's hammer but his crown.



Just wait until you try and get the socket savers out.  LOL!!

If you like the 6BQ7A's, get some Brimars  The RCA's will immediately go into storage.


----------



## UntilThen

bcowen said:


> Just wait until you try and get the socket savers out.  LOL!!
> 
> If you like the 6BQ7A's, get some Brimars  The RCA's will immediately go into storage.



Yes but what about EL34 or KT88. I want to roll those in Mjolnir 2. Might be the biggest Thor's hammer.


----------



## bcowen

UntilThen said:


> Yes but what about EL34 or KT88. I want to roll those in Mjolnir 2. Might be the biggest Thor's hammer.



Why go halfway?  Go with an 845 or 211.


----------



## Xcalibur255

whirlwind said:


> I can't wait to see @leftside  amp when it is completed.  I am a huge fan of the EL34 tube and now that he has a dictionary of info on that tube...this is going to be fun.
> I often wonder what the EL34 tube sounds like when being pushed a little bit harder than the 250 volts that mine are...but then I think, the tubes should last longer and there should be less distortion at 250 volts.
> 
> Regardless, these tubes sound great and I am excited to see this amp.


My variant will likely operate the EL34 at higher voltages.  It's not clear to me at the moment whether or not the KT150 and EL34 are actually sharing a plate voltage or not, but if they are then the EL34 is going to be pushed hard in this design because I wanted the bias points to favor the KT150 which is capable of handling more than the EL34 is.



mordy said:


> The thing is that several others reported 5998 tubes arcing and causing damage- one well known designer will not go near them....


Oh I know, I'm one of them.  Both Glenn and I lost headphones to arcing 5998s in the same year even.  It's very much a legitimate concern with these tubes.



UntilThen said:


> Several bad experiences with 5998 does not make them bad. Many on the La Figaro 339 and Crack BH thread have use them and are still using them with no issues. My pair have been working like a charm since 2017. Any tube can go bad. 5998 is no exception or more prone.


They are severely underbiased in the Darkvoice/LaFigaro amps.  I suspect they are in the bottlehead too but I won't assert that because I'm only guessing on that one.  The much more conservative operating points make issues less likely.  Many times a tube will only misbehave when it is being pushed fairly hard, otherwise the issue lies dormant.  The thing about the 5998 is, like with many tubes, it sounds quite different when driven hard vs. driven gently.  I personally think the 5998 changes character more than most other tubes in this regard.  Those Darkvoice users are hearing something totally different from the 5998 than I am when I use the tube in my GOTL.  I don't think the 5998 is a very good sounding tube at conservative operating points, it needs to be pushed for its sound to bloom.

This is dependent on amp circuit and bias design of course.


----------



## UntilThen

Xcalibur255 said:


> They are severely underbiased in the Darkvoice/LaFigaro amps.  I suspect they are in the bottlehead too but I won't assert that because I'm only guessing on that one.  The much more conservative operating points make issues less likely.  Many times a tube will only misbehave when it is being pushed fairly hard, otherwise the issue lies dormant.  The thing about the 5998 is, like with many tubes, it sounds quite different when driven hard vs. driven gently.  I personally think the 5998 changes character more than most other tubes in this regard.  Those Darkvoice users are hearing something totally different from the 5998 than I am when I use the tube in my GOTL.  I don't think the 5998 is a very good sounding tube at conservative operating points, it needs to be pushed for its sound to bloom.



I beg to differ. My previous Glenn OTL amp has the 5998 boost switch. In the on position, I don't hear any difference. So I have always left it off. At some point in fact I heard some 'urgency' in the 5998 tubes in the 'on' position. I have heard 5998 in GOTL with the on position and also on La Figaro 339 and Wa22 and they certainly don't sound underperforming on the latter 2 amps. Same 5998 magic even if each amp has it's own sonic signature.


----------



## mordy

UntilThen said:


> Tell me about it. For 30 mins, I was trying to get the tubes out of my Mjolnir 2 - without adapters and I couldn't. Mjolnir is Thor's hammer in the mythology. Such is my frustration I want to use Thor's hammer and smash this amp.
> 
> But a light bulb moment - I put some scrotch tape and wrap it around the tube and wiggle and pull it up. Relief ! See what tubes does to me.
> 
> ...


In the past we found this simple solution to pull out recalcitrant tubes - rubber finger grips:



The extra size large fits easily over the 9pin tubes and makes it easy to pull them out and also protects your fingers if the tubes are warm.


----------



## leftside

UntilThen said:


> You're living dangerously. I just play golf and get @bcowen to drive my golf cart without it going into the lake. That's excitement.
> 
> Is this motorbike or bicycle? I mean the rugged kind. I was into those at one time. These days I just do cross country free fall skiing.


Downhill mountain biking. From today:






Here’s those EL12 Spez with adapters:


----------



## UntilThen

Brilliant idea @mordy. That should work but now with socket savers it’s easy to pull out.

Thanks Leftside for both pictures they look lovely. I’ve a colleague who loves mountain biking. Some days he would come to work with his arm in a sling or leg in a cast. Then he would be back at it again. Might as well be adventurous. I’ve seen those sockets before and they don’t look too bad.

What I didn’t share or I may have, about my GOTL 5998 boost switch is this - on several occasions with 5998 in it and the boost switch on - after 30 mins or so, the amp starts to shudder. If I prolong it, it starts to vibrate. I can’t see that as a great experience for music or 5998.


----------



## A2029

Xcalibur255 said:


> My variant will likely operate the EL34 at higher voltages.  It's not clear to me at the moment whether or not the KT150 and EL34 are actually sharing a plate voltage or not, but if they are then the EL34 is going to be pushed hard in this design because I wanted the bias points to favor the KT150 which is capable of handling more than the EL34 is.



Both the KT150 and the EL34 run off of ~475V in the variant of your amp. Bias current for the KT150 is close to double that of the EL34. Bias current for the EL34 can be set to preference based on percent of max tube dissipation. The higher the percent of max dissipation, the less distortion and more power can be gotten out of the EL34, but at the cost of shorter tube life. I like the range of 70-85% for class A biased power tubes; that often gives a good balance between tube life, and still using the tube to its potential


----------



## leftside (Jan 17, 2021)

How about these big tubes @UntilThen? That's a Cossor 53KU at the front, which is a pretty big tube, but the ones at the back are much bigger. Compare to the size of the EL12.


----------



## UntilThen

leftside said:


> How about these big tubes @UntilThen? That's a Cossor 53KU at the front, which is a pretty big tube. Compare to the size of the EL12.


 
Are we comparing size?    Those aren't EL12 are they? Your previous picture yes but not these ones in the last pic.

While we're are talking 5v rectifiers, I have the same Cossor 53ku and 2 x Mullard GZ32. They are in the Woo Audio Wa22 which I'll be turning on in a tick.  Have you heard your Wa22 with 3 rectifiers running? It's da BEST.  

P/S anyone trying to emulate me and not knowing I'm joking with a straight face, do so at your own peril !



Also I'll be buying these back from @paramesh in 3 months time. Such a buddy from India. One day I'm sample your chicken biryani. 
The GEC U52 is 3rd from right. The rest you know. They were once my jewels of the Nile.


Btw Leftside, nice pictures and lovely glow. You have your Lampizator but I'll stick with Yggdrasil. You realise the 'O' is missing in Lampizator?


----------



## LoryWiv

LoryWiv said:


> @leftside, thank you so much! His KT88 price seems reasonable if they are in good condition, may go for it myself!


Thanks headfi...went for it! This pair of KT88's is most I've EVER spent on tubes, but as @UntilThen notes comparatively they are fairly priced. One of these days instead of Elise with adapters maybe I'll hit up one of you custom builders and see what this "*king of power tubes*" can do in it's native habitat. For now I need to rest my wallet and enjoy the music. 

@leftside I went for pair # 2 *here*  Any idea what year they were made?


----------



## UntilThen

@LoryWiv  ampandsound Mogwai Se uses KT88 amongst other tubes like EL34. Friend of mine has it and loves it. You can however get Mischa to custom build you one. KT88 has more bite while EL34 is smoother. General impressions going with my previous Primaluna Dialogue Premium HP running on 8 x KT88 and also after hearing Auris Nirvana running 2 x EL34.


----------



## leftside

UntilThen said:


> Are we comparing size?   Those aren't EL12 are they?


Yet another EL tube. This time EL51.


----------



## leftside

LoryWiv said:


> Thanks headfi...went for it! This pair of KT88's is most I've EVER spent on tubes, but as @UntilThen notes comparatively they are fairly priced. One of these days instead of Elise with adapters maybe I'll hit up one of you custom builders and see what this "*king of power tubes*" can do in it's native habitat. For now I need to rest my wallet and enjoy the music.
> 
> @leftside I went for pair # 2 *here*  Any idea what year they were made?


1959 and 1960. Very rare. Check out how many turn up on eBay with just the single top getter. Not very often... Between us we have (or will have) every year the version with the single getter were made 🙂


----------



## bcowen

UntilThen said:


> Are we comparing size?    Those aren't EL12 are they? Your previous picture yes but not these ones in the last pic.
> 
> While we're are talking 5v rectifiers, I have the same Cossor 53ku and 2 x Mullard GZ32. They are in the Woo Audio Wa22 which I'll be turning on in a tick.  Have you heard your Wa22 with 3 rectifiers running? It's da BEST.
> 
> ...



 I can't afford 53KU's and forced to slum with these CV378's.  Some play golf, some can only drive the cart.


----------



## mordy

With the right attitude you can be very happy driving the cart....


----------



## bcowen

mordy said:


> With the right attitude you can be very happy driving the cart....



LOL!  I'm perfectly happy driving the cart....much closer to the beer.


----------



## Zachik

LoryWiv said:


> I went for pair # 2 *here*


If you do not like them in your amp - I will be happy to buy them from you


----------



## UntilThen

bcowen said:


> I can't afford 53KU's and forced to slum with these CV378's.  Some play golf, some can only drive the cart.





mordy said:


> With the right attitude you can be very happy driving the cart....





bcowen said:


> LOL!  I'm perfectly happy driving the cart....much closer to the beer.



Probably the reason I come on head-fi. The jokes are legendary. Who needs rectifiers. I'm hitting the golf course in 2 weeks time when I get back to Canberra.


----------



## bcowen

UntilThen said:


> Probably the reason I come on head-fi. The jokes are legendary. Who needs rectifiers. I'm hitting the golf course in 2 weeks time when I get back to Canberra.



LOL! I'll be ready. Just could you please maybe think about possibly selecting a golf course _without_ lakes? I know, I know, a lot to ask, but it's me. 

PS: Canberra's not on Guam, is it?


----------



## UntilThen

Sure this is where I play or one of the golf courses. You can pick any of the golf carts to drive. Got your license now?


----------



## bcowen

UntilThen said:


> Sure this is where I play or one of the golf courses. You can pick any of the golf carts to drive. Got your license now?



I want whichever one is fastest.  And waterproof.


----------



## jonathan c

bcowen said:


> I want whichever one is fastest.  And waterproof.


...and has flotation devices close to the exits...


----------



## Xcalibur255

UntilThen said:


> I beg to differ. My previous Glenn OTL amp has the 5998 boost switch. In the on position, I don't hear any difference. So I have always left it off. At some point in fact I heard some 'urgency' in the 5998 tubes in the 'on' position. I have heard 5998 in GOTL with the on position and also on La Figaro 339 and Wa22 and they certainly don't sound underperforming on the latter 2 amps. Same 5998 magic even if each amp has it's own sonic signature.


As always, trust your own ears.  Your experience and mine differs and that's okay.


----------



## Curtisvill

I have placed my deposit and have my name in the queue for one of Mischa's White Dwarf hybrid amps.  The White Dwarf fits my current needs better than the Blue Halo or a custom OTL amp but who knows what the future brings.  My experience with tubes is currently limited to a Liquid Platinum and 6922, 12au7, EC88, and 7316 tubes so I have a lot to learn from you gents, I do not include my foray into tube amps for my 2 channel system over 20 years ago.  I have to say I feel a bit intimidated about the wealth of knowledge and experience on this thread but look forward to joining the journey with all of you.

John


----------



## mordy

Curtisvill said:


> I have placed my deposit and have my name in the queue for one of Mischa's White Dwarf hybrid amps.  The White Dwarf fits my current needs better than the Blue Halo or a custom OTL amp but who knows what the future brings.  My experience with tubes is currently limited to a Liquid Platinum and 6922, 12au7, EC88, and 7316 tubes so I have a lot to learn from you gents, I do not include my foray into tube amps for my 2 channel system over 20 years ago.  I have to say I feel a bit intimidated about the wealth of knowledge and experience on this thread but look forward to joining the journey with all of you.
> 
> John


Where can I find a link to the White Dwarf amp?


----------



## Curtisvill

mordy said:


> Where can I find a link to the White Dwarf amp?



White Dwarf Hybrid


----------



## Xcalibur255 (Jan 22, 2021)

The White Dwarf might be the most interesting of all of Mischa's offerings.  It seems to achieve almost the same output numbers that my amp will hit while being lighter and less expensive because it doesn't rely on a BAT (big ass tube) for its second gain stage.  In my case I was quite okay with the additional 2nd order harmonic distortion that comes with having two tube stages, it's really just a question of which flavor you're after at the end of the day.


----------



## mordy

Curtisvill said:


> White Dwarf Hybrid


Thanks


----------



## UntilThen

Curtisvill said:


> White Dwarf Hybrid



Ah that's what @chrisdrop has.


----------



## mordy (Jan 22, 2021)

UntilThen said:


> Ah that's what @chrisdrop has.


Chrisdrop has the Blue Halo amp:



Here is a preview of a white dwarf:



As far as I know no picture of the WD amp is available yet.


----------



## Curtisvill

UntilThen said:


> Ah that's what @chrisdrop has.



Mischa is currently working on a White Dwarf for his collection.  I believe mine will be the second, but I could be wrong.


----------



## UntilThen

Curtisvill said:


> Mischa is currently working on a White Dwarf for his collection.  I believe mine will be the second, but I could be wrong.



Yes I was mistaken by looking at White Dwarf tube combination and thinking it look the same as the Blue Halo. I don't follow this straightly so the model names are still new to me. White Dwarf is a hybrid and produces 5.5w at 30 ohms. This will drive Susvara and impressions later would be good.


----------



## Zachik

Curtisvill said:


> Mischa is currently working on a White Dwarf for his collection.  I believe mine will be the second, but I could be wrong.


Any idea what are the dimensions of this guy?  The "dwarf" part make me hopeful it is tiny...   
Seriously though - I long ago ran out of space for "yet another amp"   (but I really do want "just 1 more amp")


----------



## Xcalibur255

I think they're all supposed to use the same chassis as the Blue Halo.  I probably shouldn't answer for Mischa, but my amp is using the Blue Halo chassis and if that's possible then the White Dwarf should work in it no problem.


----------



## bcowen

mordy said:


> Chrisdrop has the Blue Halo amp:
> 
> Here is a preview of a white dwarf:
> 
> As far as I know no picture of the WD amp is available yet.



That looks _*seriously*_ scary.

Guess I better get an order put in.


----------



## Curtisvill

The chassis is the same size as the Blue Halo.

This is Mischa's explanation of the White Dwarf name -  "White Dwarf" - in relation to White Dwarf stars; as compact in volume as the earth, yet with as much mass as the sun.


----------



## A2029

UntilThen said:


> Yes I was mistaken by looking at White Dwarf tube combination and thinking it look the same as the Blue Halo. I don't follow this straightly so the model names are still new to me. White Dwarf is a hybrid and produces 5.5w at 30 ohms. This will drive Susvara and impressions later would be good.



Same tubes as the Blue Halo (1x 6SN7 and 2x 6J5). Same tube rolling as the Blue Halo, so only have to make a single tube rolling document   Could hit ~115-118dB peaks with the Susvara.



Zachik said:


> Any idea what are the dimensions of this guy?  The "dwarf" part make me hopeful it is tiny...
> Seriously though - I long ago ran out of space for "yet another amp"   (but I really do want "just 1 more amp")



Approx 35cm width by 33cm length, same as the Blue Halo.


----------



## Zachik

A2029 said:


> Approx 35cm width by 33cm length, same as the Blue Halo.


So that is a full shelf in the rack... 
What is the physical height, and what clearance does it need above that height for thermals? (my rack has no side walls, so totally open for airflow)


----------



## A2029 (Jan 22, 2021)

Zachik said:


> So that is a full shelf in the rack...
> What is the physical height, and what clearance does it need above that height for thermals? (my rack has no side walls, so totally open for airflow)



Approx 21-22cm height from bottom of feet to top of the transformer covers. Taller if you use tall tubes or tubes with adapters. No clearance above for thermals is needed if there is sufficient airflow from the sides*. Tubes produce very little heat, it's the sides of the chassis that can get up to 60-65 celcius (140F).

*edit: but maybe give a little space above your tallest tube if you are using a heat sensitive rack (e.g. wood or painted) so that it doesn't discolor over time from the warmth of the tube.


----------



## UntilThen

A2029 said:


> Could hit ~115-118dB peaks with the Susvara.



That is very interesting indeed. Could you describe the tonality of White Dwarf with 6sn7 and / or dual 6j5. Basically I want an idea of whether it's strictly transparent and neutral which I doubt would be the case here as the preamp section are tubes. On the other hand I wouldn't expect 300b kind of mid range and tubiness. Just invented the word there.  

So if you could describe how White Dwarf sound, that would be great. Thanks.


----------



## maxpudding

Seems Mischa will be very busy throughout the year (and next year?) with orders coming in 😎

I have already started thinking what’s next for my audio adventures.


----------



## Zachik

A2029 said:


> Approx 21-22cm height from bottom of feet to top of the transformer covers. Taller if you use tall tubes or tubes with adapters. No clearance above for thermals is needed if there is sufficient airflow from the sides*. Tubes produce very little heat, it's the sides of the chassis that can get up to 60-65 celcius (140F).
> 
> *edit: but maybe give a little space above your tallest tube if you are using a heat sensitive rack (e.g. wood or painted) so that it doesn't discolor over time from the warmth of the tube.


My rack is made of metal, so not heat sensitive. 
Need to figure out if I could get the the exiting shelves closer together and squeeze another shelf... otherwise, will have to figure out if I am willing to let go of 1 of my big amps 

Thanks Mischa!


----------



## leftside

@A2029 We could call my upcoming (late spring/summer) amp the Red Dwarf? It used to be one of my favorite TV shows when I was in my late teens/early 20's


----------



## bcowen

Zachik said:


> My rack is made of metal, so not heat sensitive.
> Need to figure out if I could get the the exiting shelves closer together and squeeze another shelf... otherwise, will have to figure out if I am willing to let go of 1 of my big amps
> 
> Thanks Mischa!



Get rid of an amp?!?  What? Sacrilege!  Heathen!   Just buy another rack. Sheeez.

I mean if your wife runs out of room for new shoes, does she just stop buying more?  Of course not...she just annexes more of _your_ closet space.  Fair is fair, right?


----------



## Zachik

bcowen said:


> Get rid of an amp?!? What? Sacrilege! Heathen! Just buy another rack. Sheeez.


With all honesty, if I could fit another rack in that room - I would have... Not joking!



bcowen said:


> I mean if your wife runs out of room for new shoes, does she just stop buying more? Of course not...she just annexes more of _your_ closet space. Fair is fair, right?


My GF actually does get rid of older shoes when she buys new ones... But hey, she does have 30+ pairs...

The name "White *Dwarf*" had me optimistic for a minute that it could actually be small.


----------



## chrisdrop

mordy said:


> Chrisdrop has the Blue Halo amp:
> 
> Here is a preview of a white dwarf:
> 
> As far as I know no picture of the WD amp is available yet.


I do have a Blue Halo, but slight difference from that picture, 2x C3G sockets (so I could also use the adapters/tubes I have for the GOTL). I don't have a much of a collection of 6SN7s to speak of. Here it is as I type with 2x Mullard 6J5Gs (which have been a stead pair of favourites to return to!)


----------



## A2029

leftside said:


> @A2029 We could call my upcoming (late spring/summer) amp the Red Dwarf? It used to be one of my favorite TV shows when I was in my late teens/early 20's



Sure thing, that would be appropriate with the red power button


----------



## Galapac

A2029 said:


> Sure thing, that would be appropriate with the red power button


Then the White Dwarf has a white light power button?


----------



## A2029

Galapac said:


> Then the White Dwarf has a white light power button?



Yup    It will be quite dim so that there isn't a bright white flashlight blasting out of the front of the amp.


----------



## Zachik

A2029 said:


> Yup    It will be quite dim so that there isn't a bright white flashlight blasting out of the front of the amp.


Looking forward to see photos of 1st unit build...


----------



## mordy

Congratulations on the new amp!  Very impressive!
Since you have all those meters, is there a measurable in-rush current when it starts up, or is that cancelled by the slow start circuitry?
I was told that a tube amp could require 3x the current on start-up.
How many amps can it handle? 30A?


----------



## A2029

mordy said:


> Congratulations on the new amp!  Very impressive!
> Since you have all those meters, is there a measurable in-rush current when it starts up, or is that cancelled by the slow start circuitry?
> I was told that a tube amp could require 3x the current on start-up.
> How many amps can it handle? 30A?



Thanks mordy!
All amps have some amount of inrush current that is higher than the steady state current. The White Dwarf does have inrush current limiting to reduce the inrush current. Normal current draw will be somewhere around 2 amps at 120V.


----------



## mordy

A2029 said:


> Thanks mordy!
> All amps have some amount of inrush current that is higher than the steady state current. The White Dwarf does have inrush current limiting to reduce the inrush current. Normal current draw will be somewhere around 2 amps at 120V.


Thanks. Now, how many hp er amps is that V6? (Or, as Rolls Royce would answer such a question: Adequate)


----------



## A2029

mordy said:


> Thanks. Now, how many hp er amps is that V6? (Or, as Rolls Royce would answer such a question: Adequate)



Approx 4-5 amps at 120V for the V6. 6080/6AS7/5998 are very power hungry tubes


----------



## paramesh

UntilThen said:


> Are we comparing size?    Those aren't EL12 are they? Your previous picture yes but not these ones in the last pic.
> 
> While we're are talking 5v rectifiers, I have the same Cossor 53ku and 2 x Mullard GZ32. They are in the Woo Audio Wa22 which I'll be turning on in a tick.  Have you heard your Wa22 with 3 rectifiers running? It's da BEST.
> 
> ...


OH .. thats my loot of classic beauties !!.. how spoilt am i  and be rest assured that  Woo  @UntilThen hands for sure will be running on steriods !! hahaha


----------



## leftside (Feb 4, 2021)

LoryWiv said:


> Thanks headfi...went for it! This pair of KT88's is most I've EVER spent on tubes, but as @UntilThen notes comparatively they are fairly priced. One of these days instead of Elise with adapters maybe I'll hit up one of you custom builders and see what this "*king of power tubes*" can do in it's native habitat. For now I need to rest my wallet and enjoy the music.
> 
> @leftside I went for pair # 2 *here*  Any idea what year they were made?


Did you receive them yet? When I took a look at mine I got quite the surprise. I expected to see a single halo getter at the top, which are only seen on the early versions. But, instead I see two saucer getters. I haven't seen this version mentioned anywhere - not even in the book by Pasquale Russo. I've been driving Pasquale nuts with the EL34 variations I've been finding - and also a whole bunch of related tubes - so much so that he's going to write an entirely new chapter or two in the next revision of the EL34 book (drafts already complete). Looks like he's going to need to make some amendments to his 6L6/6550/KT66/KT88 book as well 
https://musica-parole.it/manuali/guide-to-6l6-6550-kt66-kt88-by-pasquale-russo/


----------



## leftside

It looks to me that these tubes from above fit inbetween the version with the first glass shape ('M' and 'N' year codes) and the following year ('P' year code). This version with the twin saucer were probably only made for a few months with the new glass shape before GEC switched to the single top halo getter, and then later to the more common 3 getter version (one getter on top and two on the sides).


----------



## UntilThen

paramesh said:


> OH .. thats my loot of classic beauties !!.. how spoilt am i  and be rest assured that  Woo  @UntilThen hands for sure will be running on steriods !! hahaha



Para, it's going to cost me a bomb on tubes - looks like down the tube rabbit hole I go again !



leftside said:


> It looks to me that these tubes from above fit inbetween the version with the first glass shape ('M' and 'N' year codes) and the following year ('P' year code). This version with the twin saucer were probably only made for a few months with the new glass shape before GEC switched to the single top halo getter, and then later to the more common 3 getter version (one getter on top and two on the sides).



I will have a pair of NOS GEC KT88 incoming, along with GEC KT66 and Philips Miniwatt 6CA7 / EL34 xf2 with brownish black base. Quite unique. I will also have a pair of lightly used GEC KT77 and Tung Sol 6550 NOS version later. All booked along with Radiotron 807 with the D^D sign on base. Thinking of getting 5881 and some GE 6L6gc. Then that's it. Use on the Elekit 8200 in the interim while I see how your amp turns out. Ah yes going to use the EL12 spez too - have ordered the adapters from mrsxuling.

What version do you think this is? I am getting a pair of these. Is it worth the salt?


----------



## leftside

UntilThen said:


> Para, it's going to cost me a bomb on tubes - looks like down the tube rabbit hole I go again !
> 
> 
> 
> ...


Yep very nice. Big silver getter flashing on the sides. The ones you see on eBay are usually extremely well used with small and browning getter flashings. Yours are from 1978 with the 3 getters (two on the sides and one on the top) - the "classic" version. I have some of those - great tubes.


----------



## UntilThen (Feb 5, 2021)

leftside said:


> Yep very nice. Big silver getter flashing on the sides. The ones you see on eBay are usually extremely well used with small and browning getter flashings. Yours are from 1978 with the 3 getters (two on the sides and one on the top) - the "classic" version. I have some of those - great tubes.



It’s going to cost me AUD$1100 a match pair  but good to know they are ok

These were send out to me in the mail yesterday. Should get it next week as it's from Australia.

GEC KT66


Philips Miniwatt 6CA7 xf2


----------



## UntilThen

leftside said:


> Yep very nice. Big silver getter flashing on the sides. The ones you see on eBay are usually extremely well used with small and browning getter flashings. Yours are from 1978 with the 3 getters (two on the sides and one on the top) - the "classic" version. I have some of those - great tubes.



All these tubes I'm getting are brand new NOS. Not used.


----------



## LoryWiv

@UntilThen those incoming GEC's are impressive, please let us know how they sound. GEC KT88 are my favorite powers by a substantial margin! Also, if it's not a secret can you share where you are able top source these NOS beauties at high, but probably fair, prices it seems? Thanks, man!


----------



## leftside

UntilThen said:


> It’s going to cost me AUD$1100 a match pair  but good to know they are ok
> 
> These were send out to me in the mail yesterday. Should get it next week as it's from Australia.
> 
> ...


Post up the codes on those Philips EL34 when you get them and I'll tell you where they were made. Look like Mullard Blackburn but I don't know for sure. The getters at the top will also give them away.




LoryWiv said:


> @UntilThen those incoming GEC's are impressive, please let us know how they sound. GEC KT88 are my favorite powers by a substantial margin! Also, if it's not a secret can you share where you are able top source these NOS beauties at high, but probably fair, prices it seems? Thanks, man!


So, did you get yours yet?


----------



## LoryWiv

leftside said:


> Post up the codes on those Philips EL34 when you get them and I'll tell you where they were made. Look like Mullard Blackburn but I don't know for sure. The getters at the top will also give them away.
> 
> 
> 
> So, did you get yours yet?


Listenin' to em right now: Sylvania VT-107A drivers, GEC KT88 powers. A terrific combo. in my amp., I 'm sure GEC KT88 could complement any well-designed tube amp, , including Dwarfs of various colors from the skilled hand of @A2029.


----------



## UntilThen

leftside said:


> Post up the codes on those Philips EL34 when you get them and I'll tell you where they were made. Look like Mullard Blackburn but I don't know for sure. The getters at the top will also give them away.



Seller friend told me they are double ‘O’ getters and xf2. So likely Mullard Blackburn equivalent. I’ll post pictures when they arrived.

It’s the lightly used GEC KT77 that I am excited about. Very hard to find a good pair now and when you do they are super expensive. I am currently using a Genalex Gold Lion KT77 and I prefer it over Gold Lion KT88 and Electro Harmonix 6l6gc. Most tube amp lovers like the KT77.

That pair of Tung Sol 6550 NOS from the 60s is also super rare and expensive and I’m a sucker to want to buy it. Either now or will not see these tubes again.


----------



## UntilThen

LoryWiv said:


> Listenin' to em right now: Sylvania VT-107A drivers, GEC KT88 powers. A terrific combo. in my amp., I 'm sure GEC KT88 could complement any well-designed tube amp, , including Dwarfs of various colors from the skilled hand of @A2029.



Do you know that I’m selling off my Schiit Mjolnir 2 nearly new to buy that pair of NOS GEC KT88. It better be worth it but then I have 6 amps now. I could sell a few more lol.


----------



## UntilThen

It’s strange this Elekit TU-8200 amp transform with change of different type of tubes so much. The 12au7 drivers can be very expensive too if looking at Amperex, rare Sylvania, Radiotron and Brimar long plates.


----------



## Zachik

You guys, with your tube porn and tube talk - are really bad influence...


----------



## Galapac

Zachik said:


> You guys, with your tube porn and tube talk - are really bad influence...


Tell me about it. Do they use music to listen to amps instead of use amps to listen to music?


----------



## LoryWiv

Galapac said:


> Tell me about it. Do they use music to listen to amps instead of use amps to listen to music?


Yes, and yes.


----------



## UntilThen

Zachik said:


> You guys, with your tube porn and tube talk - are really bad influence...



It’s highly addictive but wait till you pop them in your amp. You will readily sell your cat for them. When my seller told me what he has, my knees grow weak with excitement. Fortunately I already have 6 pairs of NOS EL12 spez in original Telefunken boxes.

So I think a very well conceive EL34 and variant amp by Mescha will be the ultimate. What I want is a classic tube tone amp that will bring out the best in these NOS tubes. I would prefer auto bias for convenience at the expense of some compromise. The Elekit 8200 is auto bias and totally convenient.


----------



## UntilThen

Galapac said:


> Tell me about it. Do they use music to listen to amps instead of use amps to listen to music?



I use to think that but I don’t anymore because the right gear setup will transform your listening experience. I was at the HiFi shop today for turntable replacement cartridge and while waiting for them to install it, the proprietor let me into the listening room and I was literally blown away by what I heard. I wanted to give up head-fi and go to the very dark side call HiFi.

This is the demo room and the B&W 802D is singing from that $37000 cartridge and Chord power amp and Denson preamp.


----------



## Zachik

UntilThen said:


> It’s highly addictive but wait till you pop them in your amp. You will readily sell your cat for them.


I do not have a cat, so no such danger!  
BTW, any idea how many GEC KT-88 one could get for a kidney?    asking for a friend......


----------



## LoryWiv

Zachik said:


> I do not have a cat, so no such danger!
> BTW, any idea how many GEC KT-88 one could get for a kidney?    asking for a friend......


(Age of GEC) - (Age of Kidney) x 100 = Price per tube. If your kidney is older than the tube, your hearing is too far gone to enjoy the tube, so no sale.


----------



## whirlwind

UntilThen said:


> Para, it's going to cost me a bomb on tubes - looks like down the tube rabbit hole I go again !
> 
> 
> 
> ...



Nice tube haul!


----------



## UntilThen

whirlwind said:


> Nice tube haul!



Fortunately the amp uses a pair of each type otherwise I'll be in big trouble. Can you imagine getting quads of each type. I could from the supplier but the cost will be very big.


----------



## bcowen

UntilThen said:


> Para, it's going to cost me a bomb on tubes - looks like down the tube rabbit hole I go again !



I have a spare room in the hole available to rent until you can find your own place to purchase. Getting awful crowded down here though...  



UntilThen said:


> Thinking of getting 5881 and some GE 6L6gc.* Then that's it.*



Hahahahahahahahahahahahahahahahahahahahahahahahahaha!!!


----------



## bcowen

Zachik said:


> You guys, with your tube porn and tube talk - are really bad influence...



There's something about pots, kettles, and the color black that comes to mind here.  Just can't put my finger on it.


----------



## mordy

Galapac said:


> Tell me about it. Do they use music to listen to amps instead of use amps to listen to music?


There is no doubt in my mind that some people listen to music and some people listen to their equipment. Probably often a combination of the two - when you finally find the sound you want it is time to concentrate on the music.
Until the upgrade bug hits again - it never ends....
It seems to me that most people here keep on changing or adding to their equipment, including myself.
Why are we never completely happy with what we have? WHY?
(Maybe the stupendous sound you got after years of experimentation and spending tons of money becomes the “New Normal “ and it gets boring?)


----------



## jonathan c

mordy said:


> There is no doubt in my mind that some people listen to music and some people listen to their equipment. Probably often a combination of the two - when you finally find the sound you want it is time to concentrate on the music.
> Until the upgrade bug hits again - it never ends....
> It seems to me that most people here keep on changing or adding to their equipment, including myself.
> Why are we never completely happy with what we have? WHY?
> (Maybe the stupendous sound you got after years of experimentation and spending tons of money becomes the “New Normal “ and it gets boring?)


While I espouse monogamy....my ears stray...and monogampy is difficult 🤷🏻‍♂️ ...


----------



## Zachik

UntilThen said:


> Fortunately the amp uses a pair of each type otherwise I'll be in big trouble. Can you imagine getting quads of each type. I could from the supplier but the cost will be very big.


I wonder if that tube shipment will be hand delivered by 2 men in armored truck... 
Seems like it is worth as much as a small shipment to a jewelry store


----------



## mordy

jonathan c said:


> While I espouse monogamy....my ears stray...and monogampy is difficult 🤷🏻‍♂️ ...


ATM I have three tube amps but I am only using two because a) they are very different and b) I like them both. A third amp is collecting dust....- maybe time to sell it.... But what if one amp conks out? - then I would need a back-up.


----------



## bcowen

mordy said:


> ATM I have three tube amps but I am only using two because a) they are very different and b) I like them both. A third amp is collecting dust....- maybe time to sell it.... But what if one amp conks out? - then I would need a back-up.



Math has never been my strong suit, but if you have 3 amps and sell one, you'd have two left. So if one of those conks out, then the other one is the backup.  Or is my math all fubar'ed as usual?  

OTOH, there's no such thing as _too many amps_, so instead of selling one you'd be better to go ahead and buy a 4th one.


----------



## mordy

bcowen said:


> Math has never been my strong suit, but if you have 3 amps and sell one, you'd have two left. So if one of those conks out, then the other one is the backup.  Or is my math all fubar'ed as usual?
> 
> OTOH, there's no such thing as _too many amps_, so instead of selling one you'd be better to go ahead and buy a 4th one.


Your math is good - I realize that I did not explain myself clearly. The amp that is not being used sounds similar to one of the amps I use all the time but has less performance; the other amp sounds very different but I like it as well.
So if my main amp with superlative performance is not in service, I could fall back on the similar sounding amp I don't use.
Re a fourth amp:
One of my kids had left a very old ss integrated amp in the house that I found the other day. It is a Lafayette 10A from the early 70's and probably made by Kenwood in Japan. It sounds surprisingly good but one channel is very noisy. And I am not supposed to mention any transistor stuff anyhow...


----------



## UntilThen

Zachik said:


> BTW, any idea how many GEC KT-88 one could get for a kidney?  asking for a friend......



I'm afraid it's just one GEC KT88 to one NOS kidney. If it's a used kidney, it can only fetch a GE tube. @bcowen will know.  



LoryWiv said:


> (Age of GEC) - (Age of Kidney) x 100 = Price per tube. If your kidney is older than the tube, your hearing is too far gone to enjoy the tube, so no sale.



This guy knows what he is talking about.



bcowen said:


> Hahahahahahahahahahahahahahahahahahahahahahahahahaha!!!



I am glad you're entertained - makes a better golf cart driver. Btw I head back to Canberra this Sunday morning as the sun comes up, with all the gear in my SUV.



mordy said:


> There is no doubt in my mind that some people listen to music and some people listen to their equipment. Probably often a combination of the two - when you finally find the sound you want it is time to concentrate on the music.
> Until the upgrade bug hits again - it never ends....
> It seems to me that most people here keep on changing or adding to their equipment, including myself.
> *Why are we never completely happy with what we have? WHY?*
> (Maybe the stupendous sound you got after years of experimentation and spending tons of money becomes the “New Normal “ and it gets boring?)



Because we're humans and also head-fiers and being such we need change. As long as you frequent these forums you WILL upgrade unless you are a lurker. There's nothing wrong with upgrading as long as it's until then. The time between until and then varies between enthusiasts of course.


----------



## UntilThen

Zachik said:


> I wonder if that tube shipment will be hand delivered by 2 men in armored truck...
> Seems like it is worth as much as a small shipment to a jewelry store



Nah it's only tubes and 2 grand. My seller send off the KT66 and EL34 by express posts to me without insuring it. I told him if its broken or lost, I want a pair of GEC KT88 NOS as replacement. 

Can you imagine Mike Tyson showing up at your front door with a GEC KT88 on each palm and grinning at you?


----------



## UntilThen (Feb 5, 2021)

I'm interested in not only tubes. Tubes are useless without an amp. I bought this monster Kenwood KA 3300D vintage amp that is more rare than 20 GEC KT88. It's 150w into 8 ohm RMS. This drives a pair of Legacy Focus Se to insane level. I just got it home last night. Intend on using it with my tower Axis LS88 and some headphones. There's a headphone out jack and I'll try speaker taps too because those He6se aficionados love to speaker tap it. Incidentally this vintage monster is a bit warm and organic sounding and it trounce the McIntosh MC275 next to it at my friend's place.

At that time when this KA 3300D was produced, Kenwood and Accuphase were one company. That's the kind of lineage here. Oh there's a capable build in DAC too.

https://www.hifiengine.com/manual_library/kenwood/ka-3300d.shtml


----------



## jonathan c

Can you imagine Mike Tyson showing up at your front door with a GEC KT88 on each palm and grinning at you?
[/QUOTE]
...with AKM 4499 chips in lieu of front teeth...


----------



## UntilThen

jonathan c said:


> Can you imagine Mike Tyson showing up at your front door with a GEC KT88 on each palm and grinning at you?


...with AKM 4499 chips in lieu of front teeth...
[/QUOTE]

Mike will show up at your front door with a GEC KT88 inside each glove. When I say those KT88 will throw a punch I mean it and mine atm is only Genalex Gold Lion. GEC will throw you off the cliff.


----------



## Galapac

UntilThen said:


> Because we're humans and also head-fiers and being such we need change. As long as you frequent these forums you WILL upgrade unless you are a lurker. There's nothing wrong with upgrading as long as it's until then. The time between until and then varies between enthusiasts of course.


There is nothing wrong with upgrading and looking for the next best thing....it's just that some do it like I change my clothes and I was wondering if one just needs to pause to enjoy the experience....but I get it...some are moving at a faster pace then others...nothing wrong in that...some of you go by me like whoosh! A blur like the flash ...I guess I am the turtle.


----------



## jonathan c

OTOH, there's no such thing as _too many amps_
[/QUOTE]
Just for starters:  one tube transformer-coupled hpa for low-impedance hp, one tube OTL hpa for high-impedance hp, one tube/SS hpa for all impedance hp, one Violectric V280 to use as backup pending deliveries of NOS tubes & adapters for the first three hpa.


----------



## UntilThen

Galapac said:


> There is nothing wrong with upgrading and looking for the next best thing....it's just that some do it like I change my clothes and I was wondering if one just needs to pause to enjoy the experience....but I get it...some are moving at a faster pace then others...nothing wrong in that...some of you go by me like whoosh! A blur like the flash ...I guess I am the turtle.



When I started with just a Dark Voice 336se in 2015, I used to think that of other head-fiers too. These days I don't. Everyone has different capacities at different stage of their lives and INTERESTs. If you have no interest in audio equipment then all this is frivolous and a waste of time. It's just like a vinyl collector. Why do some collect 1000s of LP and some only own 300. The question is choice and affordability and of course passion. If you're a young dad then your priorities is to bring up your kids and provide for them. Others are past that ....


----------



## mordy

UntilThen said:


> I'm interested in not only tubes. Tubes are useless without an amp. I bought this monster Kenwood KA 3300D vintage amp that is more rare than 20 GEC KT88. It's 150w into 8 ohm RMS. This drives a pair of Legacy Focus Se to insane level. I just got it home last night. Intend on using it with my tower Axis LS88 and some headphones. There's a headphone out jack and I'll try speaker taps too because those He6se aficionados love to speaker tap it. Incidentally this vintage monster is a bit warm and organic sounding and it trounce the McIntosh MC275 next to it at my friend's place.
> 
> At that time when this KA 3300D was produced, Kenwood and Accuphase were one company. That's the kind of lineage here. Oh there's a capable build in DAC too.
> 
> https://www.hifiengine.com/manual_library/kenwood/ka-3300d.shtml


My daily driver amp is a 150W/ch Tandberg power amp from the same vintage (1984). It puts out 220W/ch at 4 ohm and is stable down to 2 ohm. My speakers are rated 6 ohm and I use a quad which I think means the amp sees 3ohms.



At least 60% of the amp is a heat sink:



https://www.hifiengine.com/manual_library/tandberg/tpa-3006.shtml


----------



## UntilThen

mordy said:


> My daily driver amp is a 150W/ch Tandberg power amp from the same vintage (1984). It puts out 220W/ch at 4 ohm and is stable down to 2 ohm. My speakers are rated 6 ohm and I use a quad which I think means the amp sees 3ohms.



Now we're talking. Keep that well Mordy ... I sold off my Sansui and got the Kenwood. I think it's a fair trade. Both are monsters. One of these vintage amps driving a big pair of Tannoys will move your kidneys and bowels.


----------



## UntilThen

jonathan c said:


> OTOH, there's no such thing as _too many amps_


Just for starters:  one tube transformer-coupled hpa for low-impedance hp, one tube OTL hpa for high-impedance hp, one tube/SS hpa for all impedance hp, one Violectric V280 to use as backup pending deliveries of NOS tubes & adapters for the first three hpa.
[/QUOTE]

LOL Jonathan, you're getting a Elekit TU-8200R and it's arriving in a few days time. I'm selling off 2 amps to make room in my wallet for down payment on a nice amp to run EL34 and variants. That's why I'm lurking here and see how @leftside amp is turning out. It will be my final amp and I mean it. I am so done with amps. Don't even talk to me about amps after this.


----------



## Galapac

UntilThen said:


> It will be my final amp and I mean it. I am so done with amps. Don't even talk to me about amps after this.


Hahahahahaahahahahahahaha


----------



## jonathan c

UntilThen said:


> Now we're talking. Keep that well Mordy ... I sold off my Sansui and got the Kenwood. I think it's a fair trade. Both are monsters. One of these vintage amps driving a big pair of Tannoys will move your kidneys and bowels.


Speaking of Tannoys, you might have heard of Fyne Audio...the people there are en masse alumni / alumnae of Tannoy...I have heard a couple of the FA floorstanders....dynamic & musical ! ....


----------



## UntilThen

bcowen said:


> OTOH, there's no such thing as _too many amps_, so instead of selling one you'd be better to go ahead and buy a 4th one.



Nail it Mr Bcowen! At the start of 2021, my mission is to explore solid state amps. So I bought a Questyle CMA 12 first. Next followed the v280. Then SMSL SP200. Then Mjolnir 2. Then Elekit TU-8200. There will come a time soon where I will release them all for a nice tube amp and a nah ... I don't really care about solid states that's what I found after owning all the above... except for one monster vintage amp. My preference is not some clinical, cold sounding, audiophile tone. I prefer a slightly warm, organic, analogue and 2nd harmonic distortion filled kind of tone. Pretty much like I prefer vinyl over digital. There's a big difference in tone. Despite having a Rega Rp8, I upgraded my Denon DP300F (gift from wife 4 years ago) cartridge to a 2M Blue and I was shocked at how good that is for a cheap $300.

Ortofon 2M blue in action on my turntable since yesterday.


----------



## UntilThen

jonathan c said:


> Speaking of Tannoys, you might have heard of Fyne Audio...the people there are en masse alumni / alumnae of Tannoy...I have heard a couple of the FA floorstanders....dynamic & musical ! ....



Oh man, why do you have to talk to me about Fyne Audio.... guess I'll not stopped talking here and the topic will traverse all over the world. I've my friend coming over at 10 am to help me set up the Kenwood properly. Then at 12 - 3pm, I'm heading over to a friend's place where 13 of us are gathered for a mini head-fi meet with the Australian representative of ZMF headphones and ampandsound tube amps present with all of their complete range, including a Sonnet Morpheus dac. I've a packed day coming up but before that I have to mow the lawn at 9am. Then after 4pm, I've to pack up my gear in the car for a drive off to Canberra on Sunday morning. Life is good. I've never felt so good in my life. Every stage is incredibly beautiful even when I was changing the kids nappies too many years ago.

Fyne speakers....


----------



## UntilThen

jonathan c said:


> While I espouse monogamy....my ears stray...and monogampy is difficult 🤷🏻‍♂️ ...



Hahaha I laugh so hard at this. It's the quote of the day. I always knew you are Shakespeare reincarnated.


----------



## jonathan c

Oh man, why do you have to talk to me about Fyne Audio.... guess I'll not stopped talking here and the topic will traverse all over the world. I've my friend coming over at 10 am to help me set up the Kenwood properly. Then at 12 - 3pm, I'm heading over to a friend's place where 13 of us are gathered for a mini head-fi meet with the Australian representative of ZMF headphones and ampandsound tube amps present with all of their complete range, including a Sonnet Morpheus dac. I've a packed day coming up but before that I have to mow the lawn at 9am. Then after 4pm, I've to pack up my gear in the car for a drive off to Canberra on Sunday morning. Life is good. I've never felt so good in my life. Every stage is incredibly beautiful even when I was changing the kids nappies too many years ago. 

Speaking of ZMF, I love my limbawood Auteurs. In the listening chapel of @jonathan c was heard: “I now pronounce you headphone & amp”.


----------



## whirlwind

UntilThen said:


> Just for starters:  one tube transformer-coupled hpa for low-impedance hp, one tube OTL hpa for high-impedance hp, one tube/SS hpa for all impedance hp, one Violectric V280 to use as backup pending deliveries of NOS tubes & adapters for the first three hpa.



LOL Jonathan, you're getting a Elekit TU-8200R and it's arriving in a few days time. I'm selling off 2 amps to make room in my wallet for down payment on a nice amp to run EL34 and variants. That's why I'm lurking here and see how @leftside amp is turning out. It will be my final amp and I mean it. I am so done with amps. Don't even talk to me about amps after this.
[/QUOTE]

No way pal...it is the "amp mafia" and once you are in....you are in!


----------



## bcowen

jonathan c said:


> OTOH, there's no such thing as _too many amps_


Just for starters:  one tube transformer-coupled hpa for low-impedance hp, one tube OTL hpa for high-impedance hp, one tube/SS hpa for all impedance hp, one Violectric V280 to use as backup pending deliveries of NOS tubes & adapters for the first three hpa.
[/QUOTE]

And then you always need to keep one that sounds like crap so you can listen to it once a year (for 5 minutes) and realize how great your other amps sound.  I have an EAR down in the basement.  330wpc into 8 ohms, 660 into 4 ohms, 1200 into 2 ohms IIRC (and if that's not exact, it's close).  Who was it that said if the first watt sounds like a$$, why would you want more after that?  Nelson Pass maybe?  He must have heard this amp.


----------



## bcowen

UntilThen said:


> Nail it Mr Bcowen! At the start of 2021, my mission is to explore solid state amps. So I bought a Questyle CMA 12 first. Next followed the v280. Then SMSL SP200. Then Mjolnir 2. Then Elekit TU-8200.



Dang it.  I was hoping you'd get an Elekit TU-8600S and let me know how it sounds with headphones.  So much for depending on _you_. 



UntilThen said:


> Ortofon 2M blue in action on my turntable since yesterday.



Not to nitpick or anything, but your azimuth is off by 3 degrees.  

More seriously, whoever came up with this thing should get a Nobel prize or something.  Ingenious, cheap and effective. I already have a suitcase full of cartridge setup jigs, but had to order one of these anyway.  No such thing as too many cartridge setup tools.  

https://www.ebay.com/itm/LP-Vinyl-Record-Player-Measuring-Phono-Tonearm-VTA-Cartridge-Azimuth-Ruler-10-mm/363075102088?


----------



## Zachik

UntilThen said:


> One of these vintage amps driving a big pair of Tannoys will move your kidneys and bowels.


Perfect (with the right music) for breaking up those damn kidney stones...


----------



## Galapac

UntilThen said:


> Nail it Mr Bcowen! At the start of 2021, my mission is to explore solid state amps. So I bought a Questyle CMA 12 first. Next followed the v280. Then SMSL SP200. Then Mjolnir 2. Then Elekit TU-8200. There will come a time soon where I will release them all for a nice tube amp and a nah ... I don't really care about solid states that's what I found after owning all the above... except for one monster vintage amp. My preference is not some clinical, cold sounding, audiophile tone. I prefer a slightly warm, organic, analogue and 2nd harmonic distortion filled kind of tone. Pretty much like I prefer vinyl over digital. There's a big difference in tone. Despite having a Rega Rp8, I upgraded my Denon DP300F (gift from wife 4 years ago) cartridge to a 2M Blue and I was shocked at how good that is for a cheap $300.
> 
> Ortofon 2M blue in action on my turntable since yesterday.


Nice cartridge, I use the same after having the red for a few years.


----------



## Zachik

whirlwind said:


> No way pal...it is the "amp mafia" and once you are in....you are in!


First rule of amp mafia:
You do not talk about amp mafia!


----------



## bcowen

Zachik said:


> First rule of amp mafia:
> You do not talk about amp mafia!



Vinnie and Guido have already been dispatched with aluminum baseball bats ('cause they broke the wood ones).


----------



## leftside (Feb 5, 2021)

UntilThen said:


> Seller friend told me they are double ‘O’ getters and xf2. So likely Mullard Blackburn equivalent. I’ll post pictures when they arrived.
> 
> It’s the lightly used GEC KT77 that I am excited about. Very hard to find a good pair now .


Yes very hard to find. Impossible to find NOS. I have a lightly used pair and a well used pair.



UntilThen said:


> Do you know that I’m selling off my Schiit Mjolnir 2 nearly new to buy that pair of NOS GEC KT88. It better be worth it but then I have 6 amps now. I could sell a few more lol.


Worth it from a collectors viewpoint yes - it's a piece of British music history from one of the most famous tube manufacturers in the world. Legendary KT88. Arguable if it's worth it "music wise". If they are genuine NOS/NIB I wouldn't use them as I always feel guilty about "spoiling" such historic antiques.



Galapac said:


> Tell me about it. Do they use music to listen to amps instead of use amps to listen to music?


It's a fair point and I'm guilty as charged sometimes. But, there are many many evenings when I will head up to the music room and just enjoy the music. If I'm on a tube buying spree and discovering new tubes (as I am now...) then I'll tend to listen to the differences between the tubes. But, I'll get over it and back to the music soon 



UntilThen said:


> Fortunately the amp uses a pair of each type otherwise I'll be in big trouble. Can you imagine getting quads of each type. I could from the supplier but the cost will be very big.


Another reason I went with two power tubes for the upcoming power pentode Red Dwarf. Six power tubes in the Thunder OTL was a bit OTT!

5 amps is a good number I think?
Tube monos for hifi listening
Tube 6080/5998/6AS7G headphone amp
Tube 300B headphone amp

5 channel solid state for movies (different room from above)
Tube EL34/KT66 headphone amp (different room from above)

Ok... 5 is probably a little overkill. I could survive with 4.


----------



## jonathan c

bcowen said:


> Vinnie and Guido have already been dispatched with aluminum baseball bats ('cause they broke the wood ones).


Those who breach the amp mafia ethic of silence are usually found as d(ead)-getters in a concrete tube...


----------



## Xcalibur255

bcowen said:


> And then you always need to keep one that sounds like crap so you can listen to it once a year (for 5 minutes) and realize how great your other amps sound.



I thought this was what factory car stereos were for?


----------



## LoryWiv (Feb 6, 2021)

leftside said:


> Worth it from a collectors viewpoint yes - it's a piece of British music history from one of the most famous tube manufacturers in the world. Legendary KT88. Arguable if it's worth it "music wise". If they are genuine NOS/NIB I wouldn't use them as I always feel guilty about "spoiling" such historic antiques.


@leftside I'm using my GEC KT88 now and already hunting for a backup pair. I've had some "holy grail" tubes before (Tung Sol 6SN7 BGRP) that I didn't use and treated like a museum piece, BUT theses KT88's bring me so much musical pleasure I can't see rolling them out anytime soon. The "*King of Power Tubes*" indeed!


----------



## UntilThen

leftside said:


> Worth it from a collectors viewpoint yes - it's a piece of British music history from one of the most famous tube manufacturers in the world. Legendary KT88. Arguable if it's worth it "music wise". If they are genuine NOS/NIB I wouldn't use them as I always feel guilty about "spoiling" such historic antiques.



I will use the NOS GEC KT66 and NOS Philips Miniwatt 6CA7 when it comes but I'll probably keep the GEC KT88 NOS untouched. Like you say, it's a piece of history and at $1100, I'm reluctant to burn it up.



leftside said:


> 5 amps is a good number I think?



4 is a good number.
. 300b amp probably an Elekit 8600R
. a EL34, KT66, KT88, 6L6gc, KT77 amp with 6SL7 as input. Choice here is a custom amp or a Mogwai Se. I heard the Encore today with Meze Empyrean and Dan Clark Ether 2 and it was soooo lovely. Encore uses a poor man's 300b tubes and one 6SL7.
. one solid state amp - could be the Benchmark HPA4.
. a vintage amp - I've already make my pick - it's a Kenwood KA 3300D. Driving both speakers and headphones.
. Wa22 - this is what I will keep for 6as7 / 6080.


----------



## bcowen

UntilThen said:


> I will use the NOS GEC KT66 and NOS Philips Miniwatt 6CA7 when it comes but I'll probably keep the GEC KT88 NOS untouched. Like you say, it's a piece of history and at $1100, I'm reluctant to burn it up.
> 
> 
> 
> ...



One nice thing with 6SL7's is you can get primo ones for (comparatively) cheap prices today since they aren't as 'fashionable' as 6SN7's. Only problem is with their (much) higher gain there's a higher incident rate of noise.  But if you can find ones that are good and quiet, they're a very good sounding tube IMO.


----------



## leftside (Feb 6, 2021)

LoryWiv said:


> @leftside I'm using my GEC KT88 now and already hunting for a backup pair. I've had some "holy grail" tubes before (Tung Sol 6SN7 BGRP) that I didn't use and treated like a museum piece, BUT theses KT88's bring me so much musical pleasure I can't see rolling them out anytime soon. The "*King of Power Tubes*" indeed!


Good idea! Also check the getters on yours. I have a pair of TS BGRP that I use and also a couple of "museum" pairs that I don't even want to open:


----------



## UntilThen

bcowen said:


> One nice thing with 6SL7's is you can get primo ones for (comparatively) cheap prices today since they aren't as 'fashionable' as 6SN7's. Only problem is with their (much) higher gain there's a higher incident rate of noise. But if you can find ones that are good and quiet, they're a very good sounding tube IMO.



I was using Tung Sol 12SL7gt on my previous Glenn OTL amp and it was great. A cheap version of the famed TS BGRP. AmpandSound Encore with that stock 6SL7 - I saw the label RCA on it and 1626 tubes ( poor man's 300b) was so good I wanted to buy that and be done with it but I have higher standard. 



leftside said:


> I have a pair of TS BGRP that I use and also a couple of "museum" pairs that I don't even want to open:



Leftside, you make collecting NOS tubes totally logical. The amount and variety you have of all kinds of expensive and gorgeous tubes makes your tube stash a walking gold mine. Well done and when you're bored with them, let me try some.


----------



## leftside

UntilThen said:


> I was using Tung Sol 12SL7gt on my previous Glenn OTL amp and it was great. A cheap version of the famed TS BGRP. AmpandSound Encore with that stock 6SL7 - I saw the label RCA on it and 1626 tubes ( poor man's 300b) was so good I wanted to buy that and be done with it but I have higher standard.
> 
> 
> 
> Leftside, you make collecting NOS tubes totally logical. The amount and variety you have of all kinds of expensive and gorgeous tubes makes your tube stash a walking gold mine. Well done and when you're bored with them, let me try some.


Totally agree that the TS 12SL7, 6SL7 and also 12SN7 and 6J5 are really good tubes. Some of the best.


----------



## UntilThen

leftside said:


> Totally agree that the TS 12SL7, 6SL7 and also 12SN7 and 6J5 are really good tubes. Some of the best.



I'm starting to like the 12au7 and 12at7 too. Getting a Brimar 12au7 long plates for a start. Friend wanted to sell me his NOS brand new Amperex 12au7 for $200 a piece. There's also a Sylvania 12au7 that he says is super rare and NOS brand new. They say that in the TU-8200, preamp tubes alter the sound more than power tubes but I love the power tubes looks. Who wouldn't be moved by holding a GEC KT88 in their hands.  

just don't drop it @bcowen  !


----------



## bcowen (Feb 6, 2021)

UntilThen said:


> I'm starting to like the 12au7 and 12at7 too. Getting a Brimar 12au7 long plates for a start. Friend wanted to sell me his NOS brand new Amperex 12au7 for $200 a piece. There's also a Sylvania 12au7 that he says is super rare and NOS brand new. They say that in the TU-8200, preamp tubes alter the sound more than power tubes but I love the power tubes looks. Who wouldn't be moved by holding a GEC KT88 in their hands.
> 
> just don't drop it @bcowen  !



LOL!  You know, that NEC 6AS7G is the first tube I've ever broken. I've worn some out, broken the guide pin off an octal or two, bent a pin on a noval or two, but in my long and illustrious tube career that's the first one that I've truly busted into a small pile of glass shards.  I stared at it for a moment not sure what to do.  Hold a memorial service? Go into a week-long depression? Yell at the wife (just because)? All three?  I finally just stuck a Chatham graphite plate in, played some really sad songs, and started to cry even before the Chatham had warmed up.  That was a $25 tube.  OK, fine -- it sounded like a $37 tube, but I only paid $25 for it. 

Now if I broke a genuine NOS GEC KT-anything, there'd be one less tube buyer around 'cause I'd probably commit Hari-Kari.


----------



## Zachik

bcowen said:


> I stared at it for a moment not sure what to do. Hold a memorial service? Go into a week-long depression? Yell at the wife (just because)? All three?


The correct answer on how to properly mourn the loss of a good tube:
Plug in a GE tube, and use it for a whole week. After that self-punishment, you'll never ever EVER break a tube again!!


----------



## UntilThen

bcowen said:


> You know, that NEC 6AS7G is the first tube I've ever broken.



Meh, these days I don't even get excited with GEC 6as7g anymore much less NEC 6as7g? Is there such a tube? Maybe there's a NEC KT88? 

However I did score a pair of nearly new Bendix 6080wb. Going to use that in my drone to spy on you in ... where did you say you live again?  Atlanta, Georgia, Texas?


----------



## Zachik

UntilThen said:


> Going to use that in my drone to spy on you in ... where did you say you live again?  Atlanta, Georgia, Texas?


He used to live (up until 2 weeks ago) on:
1600 Pennsylvania Avenue
Washington, D.C.


----------



## leftside

Today’s rescue mission:


----------



## whirlwind

leftside said:


> Today’s rescue mission:



nice....they look great!


----------



## bcowen

UntilThen said:


> Meh, these days I don't even get excited with GEC 6as7g anymore much less NEC 6as7g? Is there such a tube? Maybe there's a NEC KT88?
> 
> However I did score a pair of nearly new Bendix 6080wb. Going to use that in my drone to spy on you in ... where did you say you live again?  Atlanta, Georgia, Texas?



My bust.  It was actually a 6520.  Probably made by RCA.  That's it on the left (pre-accident), and a run-of-the-mill RCA 6AS7G on the right.  But it had Japanese text silkscreened on it, which was cool enough that the sonic quality was irrelevant.


----------



## bcowen

Zachik said:


> The correct answer on how to properly mourn the loss of a good tube:
> Plug in a GE tube, and use it for a whole week. After that self-punishment, you'll never ever EVER break a tube again!!



That's not punishment -- that's torture. 

After I park @UntilThen 's golf cart at the bottom of the lake, I'm gonna go break all of his GEC's to see if he gets mad.


----------



## leftside

whirlwind said:


> nice....they look great!


Sound good as well. EL3N from 1954. Once I cleaned them up I could see the date codes on both.


----------



## Zachik

bcowen said:


> After I park @UntilThen 's golf cart at the bottom of the lake


Cannot stop having these images in my mind now...












...and eventually:


----------



## leftside

bcowen said:


> My bust.  It was actually a 6520.  Probably made by RCA.  That's it on the left (pre-accident), and a run-of-the-mill RCA 6AS7G on the right.  But it had Japanese text silkscreened on it, which was cool enough that the sonic quality was irrelevant.


Ouch. That would be a painful one to drop. 6520 are rare.


----------



## Zachik

leftside said:


> Ouch. That would be a painful one to drop. 6520 are rare.


@bcowen always had style! Not even bothering himself with smashing a GE tube...


----------



## paramesh (Feb 7, 2021)

leftside said:


> Yep very nice. Big silver getter flashing on the sides. The ones you see on eBay are usually extremely well used with small and browning getter flashings. Yours are from 1978 with the 3 getters (two on the sides and one on the top) - the "classic" version. I have some of those - great tubes.


----------



## paramesh

UntilThen said:


> Para, it's going to cost me a bomb on tubes - looks like down the tube rabbit hole I go again !
> 
> 
> 
> ...


woaah ... !!... the GEC kt88 !! you have almost run through the entire GEC line up !.... do share your impressions .and the 6ca7 as well ...i am looking for a NOS Quad for my leben cs600 .. Seems like there's a Harem building around the Elikit like the GOTL ..


----------



## UntilThen

paramesh said:


> woaah ... !!... the GEC kt88 !! you have almost run through the entire GEC line up !.... do share your impressions .and the 6ca7 as well ...i am looking for a NOS Quad for my leben cs600 .. Seems like there's a Harem building around the Elikit like the GOTL ..



Hi Paramesh, my brother from the other continent.  

Not as much as I love Oblivion now. Elekit TU-8200 is cheap and very good but Oblivion is special. https://www.head-fi.org/threads/oblivion-ultrasonic-studios.902926/post-16162337


----------



## Xcalibur255

bcowen said:


> My bust.  It was actually a 6520.  Probably made by RCA.  That's it on the left (pre-accident), and a run-of-the-mill RCA 6AS7G on the right.  But it had Japanese text silkscreened on it, which was cool enough that the sonic quality was irrelevant.



It does indeed look like the RCA construction style, but I do see one notable difference.  The 6520 has copper grid posts.  I don't think I've seen an RCA 6AS7 that used copper, they always seem to be steel.  The Chathams, on the other hand, seem to usually be copper.  My ears tell me the copper rods change the sound.  Who knows if that's true but it's what my ears have told me over the years.

Perhaps these RCAs get upgraded to copper because they are uprated to be 6520s.


----------



## UntilThen

@leftside, KT66 and 6CA7 arrived. In spanking new condition. Just amazing sound from the Elekit combo now. The Elekit preamp / phono stage arrives too. This combination is now high end, to my ears at least.

6CA7 has double 'O' getters and the word xf2 is very faint on the glass but I can make it out. Drivers are Brimar 12au7 long plates and Philips Miniwatt 12au7. I do not doubt that NOS tubes sound so much better than current production tubes now and I'm only 2 hours into using the tubes. Already the sweetness is seeping through. Totally worth getting the NOS tubes even if it cost a bomb.


----------



## bcowen

UntilThen said:


> Totally worth getting the NOS tubes even if it cost a bomb.



You're spoiled.


----------



## UntilThen

bcowen said:


> You're spoiled.



I know and you spoil me by driving my golf cart.


----------



## jonathan c

UntilThen said:


> I know and you spoil me by driving my golf cart.


Drive for show, swim for dough...


----------



## bcowen

UntilThen said:


> I know and you spoil me by driving my golf cart.



It's an honor to be granted the privilege of driving your golf cart. As an added bonus, it keeps me perpetually closer to the beer.


----------



## chrisdrop

Just a small post to *appreciate*; Blue Halo sounding lovely tonight. Tight, punchy bass, air, clarity, sweetness. Really enjoying today's sounds...


----------



## chrisdrop

Today enjoying some C3Gs driving the BH. Changing tubes in this amp tweaks the colour but it always stays solid sounding in any tube setup.


----------



## UntilThen

leftside said:


> I think I see what you're doing there in the GOTL with those tubes. Great tubes to have in the toolbelt for sure. I know @UntilThen liked them a lot as well before he went all sane on us and stopped tube rolling. I also have the more slender ST type and the more bulbous ST type.



The saneness is about to end soon.  I am listening to the EL12 spez in an Elekit TU-8200 amp and it's a gorgeous sound. A custom amp incorporating EL11 and EL12 spez along with 6SL7 and KT88, EL34 plus a tube rectification base on GZ34 will be happening in 4 months time.


----------



## leftside

UntilThen said:


> The saneness is about to end soon.  I am listening to the EL12 spez in an Elekit TU-8200 amp and it's a gorgeous sound. A custom amp incorporating EL11 and EL12 spez along with 6SL7 and KT88, EL34 plus a tube rectification base on GZ34 will be happening in 4 months time.


Glad to hear. Let me add to the refound insanity. For the last few months I've been researching and searching for EL34, EL11 and EL12 relatives after reading the EL34 book by Pasquale Russo. Based upon some of my discussions with Pasquale and some of our findings, he is now going to include a chapter (and perhaps even a separate book...) on these tubes. The tubes are mainly 4689, 4699, 4654, EL50. The 4654 and EL50 are easier to find, although not exactly common. These are fantastic sounding tubes, and some believe they are better than the EL34:
https://jacmusic.com/nos/EL50/index.htm

As with most tubes, there are many variations. Different getters, etc, but I think most 4654 from the same manufacturer sound the same no matter when they were produced. I find the bulbous to be a little warmer than the metal base. Very much looking forward to using them in the Red Dwarf.


----------



## leftside

Here's a few more:

4654, 4689/EL5, EL6, EL51, EL5.


----------



## UntilThen

Haha you’ve gone down a giant rabbit hole. Besides kt88 KT77 kt66 EL34, 6l6gc, 6550, 807, I can also use kt120 and kt150.

I’m about to enter a big rabbit hole or I’ve already started.


----------



## leftside

UntilThen said:


> Haha you’ve gone down a giant rabbit hole. Besides kt88 KT77 kt66 EL34, 6l6gc, 6550, 807, I can also use kt120 and kt150.
> 
> I’m about to enter a big rabbit hole or I’ve already started.


807 are meant to be bargain KT66 although I don't have any. No 6L6GC, 6550, KT120 or KT150 for me either. Let me know what you think.


----------



## UntilThen

I’m getting 2 pairs of 807, a Canadian brand because there is a maple leaf on the base. Was told it’s very rare and a Radiotron.

I have already sampled EH 6l6gc in Elekit and while I like it - it’s very slightly warm - I prefer the KT77. Love the Miniwatt EL34 too. All these tubes I can use now on Elekit while waiting for the custom amp.


----------



## leftside

UntilThen said:


> I’m getting 2 pairs of 807, a Canadian brand because there is a maple leaf on the base. Was told it’s very rare and a Radiotron.


I should get those! A bit nicer than the symbol on one of those Philips wartime tubes from above I posted.


----------



## Galapac

leftside said:


> Glad to hear. Let me add to the refound insanity. For the last few months I've been researching and searching for EL34, EL11 and EL12 relatives after reading the EL34 book by Pasquale Russo. Based upon some of my discussions with Pasquale and some of our findings, he is now going to include a chapter (and perhaps even a separate book...) on these tubes. The tubes are mainly 4689, 4699, 4654, EL50. The 4654 and EL50 are easier to find, although not exactly common. These are fantastic sounding tubes, and some believe they are better than the EL34:
> https://jacmusic.com/nos/EL50/index.htm
> 
> As with most tubes, there are many variations. Different getters, etc, but I think most 4654 from the same manufacturer sound the same no matter when they were produced. I find the bulbous to be a little warmer than the metal base. Very much looking forward to using them in the Red Dwarf.


One of your 4654 tubes has the Nazi eagle emblem which would put in the late 1930s - 1940s timeframe. What a unique piece of history you have there. That the tube survived Nazi era Germany is amazing in of itself.


----------



## leftside

Galapac said:


> One of your 4654 tubes has the Nazi eagle emblem which would put in the late 1930s - 1940s timeframe. What a unique piece of history you have there. That the tube survived Nazi era Germany is amazing in of itself.


That's right. I have a few of those 4654. I'm a bit of a history buff, but it still felt very strange handling such tubes knowing where they came from. I was also amazed they survived. They sound really good! At least they have a good use now.


----------



## mordy

leftside said:


> Here's a few more:
> 
> 4654, 4689/EL5, EL6, EL51, EL5.


I think that Zachik already is using EL6 in his EL3N amp. You also have to look for the EL 6spez with an anode cap.



(Not to be confused with an EL 6spec which is a 4699)


----------



## UntilThen

The unmistakable grey colour of Telefunken tubes.


----------



## LoryWiv

UntilThen said:


> I’m getting 2 pairs of 807, a Canadian brand because there is a maple leaf on the base. Was told it’s very rare and a Radiotron.
> 
> I have already sampled EH 6l6gc in Elekit and while I like it - it’s very slightly warm - I prefer the KT77. Love the Miniwatt *EL34* too. All these tubes I can use now on Elekit while waiting for the custom amp.


Hey @UntilThen can EL34 run in the same adapters one uses for 6L6?


----------



## UntilThen

LoryWiv said:


> Hey @UntilThen can EL34 run in the same adapters one uses for 6L6?



I don’t use 6L6. I use 6L6GC. They are different. In Elekit TU8200 and Mogwai Se, kt88 KT77 kt66 6l6gc, 6550, EL34 use the same socket without adapters. Odyssey and @leftside forthcoming amp would be the same. 807 and EL12 spez need adapters in those same tube sockets.

You use the word adapters. I think you meant the tube sockets in the amp.

6L6, 6L6G, 6L6GA are different from 6L6GC. You need to check with your amp builder for compatibility.


----------



## Zachik

mordy said:


> I think that Zachik already is using EL6 in his EL3N amp. You also have to look for the EL 6spez with an anode cap.
> 
> (Not to be confused with an EL 6spec which is a 4699)


Always had bad experience with top cap tubes. Trying to stay away from those...


----------



## mordy

Zachik said:


> Always had bad experience with top cap tubes. Trying to stay away from those...


There is a simple little fix to keep the tube anode cap from falling off. I brush on a tiny bit of crazy glue around the bottom of the cap where it meets the glass, let it dry overnight, and have not had any problems with the anode caps after doing this.
Deyan’s adapters have a little set screw in the cap - a very light twist with a small flat blade screwdriver and the cap will stay on securely.


----------



## Zachik

mordy said:


> There is a simple little fix to keep the tube anode cap from falling off. I brush on a tiny bit of crazy glue around the bottom of the cap where it meets the glass, let it dry overnight, and have not had any problems with the anode caps after doing this.
> Deyan’s adapters have a little set screw in the cap - a very light twist with a small flat blade screwdriver and the cap will stay on securely.


My issue was RF interference related... I doubt crazy glue would help 
Others suggested various things to try - none helped. Maybe my place is just infested with RF noise and the towel needs to be thrown in. Plenty other (non-top-cap) tubes, so I guess it is what it is for me...


----------



## leftside

It’s a metal base kind of evening


----------



## UntilThen

Lots of rolling options there Leftside. Are the c3g on or you switch it off via a switch?


----------



## bcowen

leftside said:


> It’s a metal base kind of evening



Sweet!  Try and get a pic like that with transistors...


----------



## leftside (Feb 16, 2021)

UntilThen said:


> Lots of rolling options there Leftside. Are the c3g on or you switch it off via a switch?


Just one set of driver tubes can be engaged at once. In this case 12SN7. C3g and 6J5 are inactive.


----------



## UntilThen (Feb 16, 2021)

leftside said:


> Just one set driver of driver tubes can be engaged at once. In this case 12SN7. C3g and 6J5 are inactive.



I have kind of forgotten in my conversations with you but does your headphones amp (5998 Galileo and Glenn 300b amp) drives speakers? I.e have speakers out? I think unlikely as like me. you have nice and sexy stereo amps for that task. I've specified speakers out because after living with Elekit TU-8200, I was amaze at what 8 quality watts in ultralinear mode can do and sound with even inefficient speakers. I'm expecting 10w in triode mode, more in ultralinear for my next custom amp. It's just convenient sitting at my big desk with speakers flanking the wide monitor, to be able to have your headphone amp also drive that adequately as well.

Sorry I don't know what your other amp is call and I've call it Galileo


----------



## leftside

UntilThen said:


> I have kind of forgotten in my conversations with you but does your headphones amp (5998 Galileo and Glenn 300b amp) drives speakers? I.e have speakers out? I think unlikely as like me. you have nice and sexy stereo amps for that task. I've specified speakers out because after living with Elekit TU-8200, I was amaze at what 8 quality watts in ultralinear mode can do and sound with even inefficient speakers. I'm expecting 10w in triode mode, more in ultralinear for my next custom amp. It's just convenient sitting at my big desk with speakers flanking the wide monitor, to be able to have your headphone amp also drive that adequately as well.
> 
> Sorry I don't know what your other amp is call and I've call it Galileo


Called 1101 amp “V6” or “Thunder”. No speaker outs for me as I have speaker amps. I agree that you can drive a lot with 8-10 watts, but my speakers are Dynaudio and B&W and they need a little more oomph.


----------



## whirlwind

leftside said:


> It’s a metal base kind of evening



Oh man....power tube overload


----------



## A2029

Enjoying some EL34 rolls tonight in a Blue Halo via adapters.





Also some of these little guys:


----------



## chrisdrop

I've been enjoying 2x Foton 6N6Ps via a pair of your adapters lately. Fun times. You suggested as much, but these 6N6Ps are super-duper quiet for some reason. I also have one of these tubes in my DAC FWIW...


----------



## L0rdGwyn

A2029 said:


> Also some of these little guys:



The KT150 remind of me of little rocket ships, really round out the space vibes 🚀☄️🛰️🧑‍🚀


----------



## L0rdGwyn

leftside said:


> Here's a few more:
> 
> 4654, 4689/EL5, EL6, EL51, EL5.



I was able to find triode curves for the EL6 and EL51, but not for the others, maybe they are out in the interwebs somewhere.

Do you still think you might get an etracer @leftside ?  Could then trace curves for all of these old tubes, would be interesting to see their linearity relative to the EL34, EL3, etc.


----------



## UntilThen

A2029 said:


> Enjoying some EL34 rolls tonight in a Blue Halo via adapters.


Pop in a pair of Telefunken EL12 spez and I like to know what you think of them. They sounded with more bite and clarity than my Philips Miniwatt 6CA7 / EL34. However there are no bad tubes here. Both are just sterling in their tone. Even the RFT EL34 from Germany is just as amazing and it's slightly cheaper.


----------



## Zachik

A2029 said:


> Enjoying some EL34 rolls tonight in a Blue Halo via adapters.


I sure hope you're enjoying this amp, while building the next!  
(and I am not even on the queue...  )


----------



## A2029 (Feb 20, 2021)

This is quite interesting: EL34 tubes (Svetlana in this case) run in the BH have over 10X the 2nd harmonic distortion than a 6SN7 (Rogers branded Sylvania). This was at ~80dB into HD650's. The spikes at 8Khz and 16Khz can be ignored as they are from the switching power supply hooked up to the DAC feeding into the amp.

Edit: These results are to be expected as EL34 run in a BH are run near the "knee" of their plate curves, so more distortion is normal and predicted from simulations of these tubes.

EL34 - 2nd harmonic at 0.035%






6SN7 - 2nd harmonic at 0.0031%


----------



## Zachik

A2029 said:


> This is quite interesting: EL34 tubes (Svetlana in this case) run in the BH have over 10X the 2nd harmonic distortion than a 6SN7 (Rogers branded Sylvania). This was at ~80dB into HD650's. The spikes at 8Khz and 16Khz can be ignored as they are from the switching power supply hooked up to the DAC feeding into the amp.
> 
> EL34 - 2nd harmonic at 0.035%
> 
> ...


I am curious: how did you generate those graphs? Can you please share with us the setup and measurement tools used?
Thanks!


----------



## A2029

Zachik said:


> I am curious: how did you generate those graphs? Can you please share with us the setup and measurement tools used?
> Thanks!



Quite simple setup: Schiit Modius DAC fed from a laptop, going into a Blue Halo amp. Output from the BH going into a Motu M4. REW running on laptop to capture the distortion plots. After tubes were in place, amp was turned on and given 20 mins warmup and volume set to produce 80dB volume (sinewave of 1 Khz) into HD650s. Headphones unplugged prior to measurements.


----------



## Zachik

A2029 said:


> Quite simple setup: Schiit Modius DAC fed from a laptop, going into a Blue Halo amp. Output from the BH going into a Motu M4. REW running on laptop to capture the distortion plots. After tubes were in place, amp was turned on and given 20 mins warmup and volume set to produce 80dB volume (sinewave of 1 Khz) into HD650s. Headphones unplugged prior to measurements.


Interesting. What is the connection from the Motu M4 to the laptop? USB? (so Motu acts as an ADC?)


----------



## A2029

Zachik said:


> Interesting. What is the connection from the Motu M4 to the laptop? USB? (so Motu acts as an ADC?)


That's correct, USB with the Motu M4 acting as the ADC.


----------



## leftside

L0rdGwyn said:


> I was able to find triode curves for the EL6 and EL51, but not for the others, maybe they are out in the interwebs somewhere.
> 
> Do you still think you might get an etracer @leftside ?  Could then trace curves for all of these old tubes, would be interesting to see their linearity relative to the EL34, EL3, etc.


Definitely will get the etracer. Just did a few mountain bike upgrades, so etracer will be Spring time.


----------



## Zachik

A2029 said:


> That's correct, USB with the Motu M4 acting as the ADC.


Cool. Maybe I should get one of those... 
@L0rdGwyn - I know you use a different gadget for lowering from headphone out to line level (2V) and then feed it to sound card. Why not use the Motu M4 as well, fed straight from headphone out of your amp? or are you using the M4 but still need to lower the signal amplitude to 2V swing?


----------



## L0rdGwyn (Feb 20, 2021)

A2029 said:


> That's correct, USB with the Motu M4 acting as the ADC.



Hey I have the same ADC in my measurements rig!  Whatdoyaknow.  Think I posted some loopback measurements over at Audio Science Review when the thing had just come out, pretty impressive for the price.



Zachik said:


> Cool. Maybe I should get one of those...
> @L0rdGwyn - I know you use a different gadget for lowering from headphone out to line level (2V) and then feed it to sound card. Why not use the Motu M4 as well, fed straight from headphone out of your amp? or are you using the M4 but still need to lower the signal amplitude to 2V swing?



This works fine for headphone voltages, but not for speaker amplifier voltages.  You can run a headphone out into the line input of a typical ADC without issue, but the signal needs to be attenuated for speaker level amplification, assuming the output swing it is greater than line level.  For that, I use the Linear Audio Autoranger.


----------



## Zachik

L0rdGwyn said:


> This works fine for headphone voltages, but not for speaker amplifier voltages. You can run a headphone out into the line input of a typical ADC without issue, but the signal needs to be attenuated for speaker level amplification, assuming the output swing it is greater than line level. For that, I use the Linear Audio Autoranger.


Yeah, the Autoranger... forgot its name from when you mentioned it before 
Cool - will get myself an M2 or M4. Should be fun being able to take basic measurements to compare *headphone* amps, or compare different tubes in the same amp  
Any relevant difference between the M2 vs. M4 for that ADC application?


----------



## A2029 (Feb 20, 2021)

Zachik said:


> Yeah, the Autoranger... forgot its name from when you mentioned it before
> Cool - will get myself an M2 or M4. Should be fun being able to take basic measurements to compare *headphone* amps, or compare different tubes in the same amp
> Any relevant difference between the M2 vs. M4 for that ADC application?



M2 doesn't have line level inputs on the back, so has to go through the pre input on the front which I believe slightly reduces accuracy of the input and increases noise very slightly, but not a big deal unless you are doing sensitive measurements.


----------



## Zachik

A2029 said:


> M2 doesn't have line level inputs on the back, so has to go through the pre input on the front which I believe slightly reduces accuracy of the input and increases noise very slightly, but not a big deal unless you are doing sensitive measurements.


I guess for extra $50 - I may as well splurge and get the M4 then...


----------



## Jaeger18

I cant help but to post this


----------



## Zachik

Jaeger18 said:


> I cant help but to post this


Beautiful amp! 
I am jealous - none of my amps (and I have quite a few) have VU meter...


----------



## leftside

Jaeger18 said:


> I cant help but to post this


I found those meters  We had a bit of "trial and error" getting them to work properly, but I'm glad Mischa did as they do look nice. You are teasing us tho..... by only showing one...


----------



## Zachik

leftside said:


> I found those meters  We had a bit of "trial and error" getting them to work properly, but I'm glad Mischa did as they do look nice.


Maybe I should add one of those to my rack...   




Poor man's VU meters...



leftside said:


> You are teasing us tho..... by only showing one...


My "interesting" amps (i.e. not counting pedestrian Lyr3 and the such) are 2 Glenns (6EL3N and GOTL), 2 Cavallis, and a custom 2-in-1 eStat amp


----------



## Zachik

A2029 said:


> Output from the BH going into a Motu M4.


Mischa - are you using a stereo 1/4" male (into BH headphone jack) --> 2 x mono 1/4" males (into M4's "LINE IN" on the back)?
Something like: https://www.amazon.com/Tisino-Stereo-Y-Splitter-Return-Insert/dp/B07K59P692/


----------



## A2029

Zachik said:


> Mischa - are you using a stereo 1/4" male (into BH headphone jack) --> 2 x mono 1/4" males (into M4's "LINE IN" on the back)?
> Something like: https://www.amazon.com/Tisino-Stereo-Y-Splitter-Return-Insert/dp/B07K59P692/



That cable will work. On your amp you also need to provide a load similar to what the amp will see. An easy way to do this is if you have a 4pin XLR out as well as the 1/4" out on your amp, then you can buy a male 4pin XLR connector and solder in some 300 ohm resistors for each channel (to mimic a 300 ohm Sennheiser or ZMF load). Plug that 4pin XLR connector with resistors in at the same time as you are running the 1/4" out to the Motu.


----------



## raindownthunda

Jaeger18 said:


> I cant help but to post this


Looks awesome! Which VU meters are those?


----------



## A2029

raindownthunda said:


> Looks awesome! Which VU meters are those?



Those are the S45's 45mm


----------



## Zachik

A2029 said:


> That cable will work.


If you recommend a different one - I am all ears!  



A2029 said:


> On your amp you also need to provide a load similar to what the amp will see. An easy way to do this is if you have a 4pin XLR out as well as the 1/4" out on your amp, then you can buy a male 4pin XLR connector and solder in some 300 ohm resistors for each channel (to mimic a 300 ohm Sennheiser or ZMF load). Plug that 4pin XLR connector with resistors in at the same time as you are running the 1/4" out to the Motu.


Wait... Why not just use a 300 Ohm headphone instead of dummy load on the XLR jack?


----------



## jonathan c

Zachik said:


> If you recommend a different one - I am all ears!
> 
> 
> Wait... Why not just use a 300 Ohm headphone instead of dummy load on the XLR jack?


Besides, the 300 ohm headphone is unlikely to be purely resistive? Would not its impedance vary with frequency?


----------



## A2029

Zachik said:


> If you recommend a different one - I am all ears!



Nope, that one should work great!



Zachik said:


> Wait... Why not just use a 300 Ohm headphone instead of dummy load on the XLR jack?



You can definitely do that as well if you are only testing each tube or amplifier swap at a specific frequency. That would give you the particular distortion measurement at that specific frequency for that specific headphone.  But as jonathan says, the impedance of a headphone will vary with frequency, so a frequency sweep (for measuring frequency response and distortion measurement across frequencies) would be affected by the headphone plugged in.


----------



## bcowen

Jaeger18 said:


> I cant help but to post this



Sweet!  Totally gorgeous.  But the VU meter indicates you need to turn the volume up. Lots.


----------



## Zachik

A2029 said:


> You can definitely do that as well if you are only testing each tube or amplifier swap at a specific frequency. That would give you the particular distortion measurement at that specific frequency for that specific headphone. But as jonathan says, the impedance of a headphone will vary with frequency, so a frequency sweep (for measuring frequency response and distortion measurement across frequencies) would be affected by the headphone plugged in.


Got it. Maybe I should build a load box, like the one @L0rdGwyn uses...


----------



## jonathan c

leftside said:


> I found those meters  We had a bit of "trial and error" getting them to work properly, but I'm glad Mischa did as they do look nice. You are teasing us tho..... by only showing one...


A mono amp?......cyclamp?


----------



## Xcalibur255

I rather like the decibel meter implementation on my Luxman amp.  I feel as far as meters go this is one of the more practical ones to have as it shows you visually how much headroom you have left at the volume level you are currently playing at.


----------



## Zachik (Feb 22, 2021)

A2029 said:


> You can definitely do that as well if you are only testing each tube or amplifier swap at a specific frequency. That would give you the particular distortion measurement at that specific frequency for that specific headphone. But as jonathan says, the impedance of a headphone will vary with frequency, so a frequency sweep (for measuring frequency response and distortion measurement across frequencies) would be affected by the headphone plugged in.





Zachik said:


> Got it. Maybe I should build a load box, like the one @L0rdGwyn uses...


Keep thinking about this... So, any advantage or disadvantage of using such box as a dummy load on the 2nd headphone jack vs. being a pass-through between the headphone amp and the Motu M4? 

This?




Or this?


----------



## A2029

Zachik said:


> Keep thinking about this... So, any advantage or disadvantage of using such box as a dummy load on the 2nd headphone jack vs. being a pass-through between the headphone amp and the Motu M4?
> 
> This?
> 
> ...



As long as the 4pin XLR and the 1/4" outputs are the same (i.e. you aren't trying to measure an amplifier that has separate balanced and summed single ended outputs), then either of these will be equivalent. If you plan to measure solid state amps that are inherently balanced but have summed single ended, then go with scenario 2. If just using for single ended tube amps, then you can go with either


----------



## Zachik

A2029 said:


> As long as the 4pin XLR and the 1/4" outputs are the same (i.e. you aren't trying to measure an amplifier that has separate balanced and summed single ended outputs), then either of these will be equivalent. If you plan to measure solid state amps that are inherently balanced but have summed single ended, then go with scenario 2. If just using for single ended tube amps, then you can go with either


Thanks Mischa. For the dummy load resistors - would 5W resistors be enough? I know @L0rdGwyn used much more substantial resistors, but then again he plugs it to the speaker taps. Not headphone out...


----------



## A2029

Zachik said:


> Thanks Mischa. For the dummy load resistors - would 5W resistors be enough? I know @L0rdGwyn used much more substantial resistors, but then again he plugs it to the speaker taps. Not headphone out...



For headphone amp measurements, even 2-3W metal film should be plenty. Stay away from inductive wirewounds if possible.


----------



## Jaeger18 (Feb 22, 2021)

Zachik said:


> Beautiful amp!
> I am jealous - none of my amps (and I have quite a few) have VU meter...



It really changes the listening experience, so instead of ONLY using  your ear, now there is a reason to use your eye.




leftside said:


> I found those meters  We had a bit of "trial and error" getting them to work properly, but I'm glad Mischa did as they do look nice. You are teasing us tho..... by only showing one...



Only if you call me "daddy" lol, jk... Tbh the reason why i got attracted to 1101 AUDIO in the first place is because of you. You were the one who gave Mischa showcase his work. So i thank you for luring me to Mischa...  Nw, more pictures coming, but i think you will be disapointed since out of the 50 pictures that i took i think this is the best one lol... 



raindownthunda said:


> Looks awesome! Which VU meters are those?



If money wasnt the issue i wouldve gone with ( https://www.don-audio.com/Vintage-Meters-VM-B10R-LED-1mA-Retro-VU-Meter-LED-Illuminated ) but after lots of consideration i took Mischa advice and use S45 500UA VU Meter ( http://www.jjyaudio.com/productview.asp?sid=1491 ) instead. It is much cheaper but still retains the vintage aesthetic.



bcowen said:


> Sweet!  Totally gorgeous.  But the VU meter indicates you need to turn the volume up. Lots.



i cannot go past 11 o clock, 9 oclock is the ideal volume to me... One more thing to mention, i think VU meter's needle fluctuates depending more on the volume of the DAC rather than the volume of the AMP. so in my case, eventhough the volume of the AMP is 0, the needle still goes up and down whenever i maxed out my DAC.


----------



## L0rdGwyn (Feb 22, 2021)

Zachik said:


> Thanks Mischa. For the dummy load resistors - would 5W resistors be enough? I know @L0rdGwyn used much more substantial resistors, but then again he plugs it to the speaker taps. Not headphone out...



I think I used 25W non-inductive wirewounds, which is way overkill for headphones lol.  I put BNC connectors on the output, works great for connecting the Autoranger or a scope.  Having a switchable dummy load is convenient for quickly seeing how load affects distortion, frequency response, or making quick output impedance measurements.  I have been meaning to build one for speakers as well.  Would use 4, 6, 8, 16ohm dummies with speaker binding post inputs and BNC outputs, just haven't gotten around to it yet, maybe I will make a shopping list today.


----------



## Zachik

L0rdGwyn said:


> I think I used 25W non-inductive wirewounds, which is way overkill for headphones lol.  I put BNC connectors on the output, works great for connecting the Autoranger or a scope.  Having a switchable dummy load is convenient for quickly seeing how load affects distortion, frequency response, or making quick output impedance measurements.  I have been meaning to build one for speakers as well.  Would use 4, 6, 8, 16ohm dummies with speaker binding post inputs and BNC outputs, just haven't gotten around to it yet, maybe I will make a shopping list today.


I think I will avoid going overboard, and use 3W resistors... 
Probably 300, 150 or 120, 64 and 32 ohms?   
Still thinking of a way to avoid the expensive 3P switch from Goldpoint - maybe use 3 or 4 plugs for 1/4" out for the discrete loads? but how do I make it such that only plug with plugged-in cable loads the amp? maybe switching 1/4" jack?
(sorry for my rumblings...)
Also need a project box / case. (or do I want to throw more money Dave's way for a nice case??)
BNC is a nice idea for scope connection, but I think I would more likely use it straight to the Motu M4. If I end up using 1 OUT jack - maybe I will just put both!
@L0rdGwyn - if I throw in a BNC connector, do I need to do anything special when wiring it? A resistor or anything? or is it just going to be in parallel wired to the 1/4" jack?

At least that gives me something to think about and eventually to keep me doing some DIY stuff (when I get to the execution phase)


----------



## L0rdGwyn (Feb 22, 2021)

Zachik said:


> I think I will avoid going overboard, and use 3W resistors...
> Probably 300, 150 or 120, 64 and 32 ohms?
> Still thinking of a way to avoid the expensive 3P switch from Goldpoint - maybe use 3 or 4 plugs for 1/4" out for the discrete loads? but how do I make it such that only plug with plugged-in cable loads the amp? maybe switching 1/4" jack?
> (sorry for my rumblings...)
> ...



I just used a Hammond case, don't think it is worth the cost of a custom case, for me it is a tool, so it doesn't need to look nice.

Just like an RCA, BNC is hot and ground, nothing special needed.  I use BNC to RCA adapters if I want to run the output directly into the ADC.  Keep in mind with a DAC/ADC measurements setup, you will not be able to do square wave analysis.  Due to bandwidth limitations of the DAC, it cannot create an accurate square wave, you need a dedicated signal generator for that and the output needs to be read on an oscilloscope.  So, I prefer BNC for flexibility.


----------



## Xcalibur255

Sooo....... I feel like I'm the only person here who mainly listens with his eyes closed?


----------



## Galapac (Feb 22, 2021)

Xcalibur255 said:


> Sooo....... I feel like I'm the only person here who mainly listens with his eyes closed?


That is the only way I can truly enjoy the music and "feel" the landscape of the music around me.
Otherwise my other senses get in the way and it becomes background noise, sometimes like this thread.


----------



## bcowen

Xcalibur255 said:


> Sooo....... I feel like I'm the only person here who mainly listens with his eyes closed?



LOL!  You're not.  I'm just hoping @L0rdGwyn doesn't do his test measurements with his eyes closed.


----------



## Zachik

L0rdGwyn said:


> I just used a Hammond case, don't think it is worth the cost of a custom case, for me it is a tool, so it doesn't need to look nice.


Agreed! Will probably do the same.



L0rdGwyn said:


> Just like an RCA, BNC is hot and ground, nothing special needed. I use BNC to RCA adapters if I want to run the output directly into the ADC.


I am thinking maybe have both (RCA or 1/4" *and* BNC) for convenience. Did you use a Goldpoint 3P selector for the various loads? Those are pretty pricey, especially since it is for a novelty tool and all...



L0rdGwyn said:


> Keep in mind with a DAC/ADC measurements setup, you will not be able to do square wave analysis. Due to bandwidth limitations of the DAC, it cannot create an accurate square wave, you need a dedicated signal generator for that and the output needs to be read on an oscilloscope. So, I prefer BNC for flexibility.


I actually have a dedicated signal generator  
To measure FR of an amp - don't you need a sine wave? and do a frequency sweep from 20Hz to 20KHz? feed the amp with said sweep, and measure the output from headphone jack (through the load box and the M4)?


----------



## L0rdGwyn

Zachik said:


> Agreed! Will probably do the same.
> 
> 
> I am thinking maybe have both (RCA or 1/4" *and* BNC) for convenience. Did you use a Goldpoint 3P selector for the various loads? Those are pretty pricey, especially since it is for a novelty tool and all...
> ...



I think I did use a Goldpoint, I was on a kick, but I'm sure you can come up with something cheaper.

If you use a program like Arta or REW, you can do it multiple ways.  Arta uses pink noise, you can do sweeps in REW.


----------



## Xcalibur255

Galapac said:


> That is the only way I can truly enjoy the music and "feel" the landscape of the music around me.
> Otherwise my other senses get in the way and it becomes background noise, sometimes like this thread.


I was going to click the like button on your post but it appears the like buttons have vanished!


----------



## cdanguyen08

Xcalibur255 said:


> I was going to click the like button on your post but it appears the like buttons have vanished!


Just liked your post to see if they really vanished!


----------



## Xcalibur255

cdanguyen08 said:


> Just liked your post to see if they really vanished!


I figured it out.  Just within the last hour the uBlockOrigin Firefox extension started blocking and hiding the like buttons on the site.  Weird.


----------



## A2029

Zachik said:


> Agreed! Will probably do the same.
> 
> I am thinking maybe have both (RCA or 1/4" *and* BNC) for convenience. Did you use a Goldpoint 3P selector for the various loads? Those are pretty pricey, especially since it is for a novelty tool and all...
> 
> ...



You can get away with using a super cheap 2 pole rotary switch. Number of positions will be your number of desired resistances to test. I.e. If you wanted a switch for 300, 150 or 120, 64 and 32 ohms, you would get a 2 pole, 5+ position switch.


----------



## LoryWiv

Xcalibur255 said:


> Sooo....... I feel like I'm the only person here who mainly listens with his eyes closed?


Yes, this is the best way to really appreciate music! Not always practical, but definitely best!


----------



## Zachik

A2029 said:


> You can get away with using a super cheap 2 pole rotary switch. Number of positions will be your number of desired resistances to test. I.e. If you wanted a switch for 300, 150 or 120, 64 and 32 ohms, you would get a 2 pole, 5+ position switch.


So just connect input (1.4" female) ground to output (RCA / 1/4" / BNC) ground, and run R and L signal wires through the 2-pole rotary switch?


----------



## A2029

Zachik said:


> So just connect input (1.4" female) ground to output (RCA / 1/4" / BNC) ground, and run R and L signal wires through the 2-pole rotary switch?


Like this (quickly drawn in Paint, lol). Only one channel shown:


----------



## Zachik

A2029 said:


> Like this (quickly drawn in Paint, lol). Only one channel shown:


Just as I thought 
Thanks Mischa!!


----------



## leftside

Jaeger18 said:


> If money wasnt the issue i wouldve gone with ( https://www.don-audio.com/Vintage-Meters-VM-B10R-LED-1mA-Retro-VU-Meter-LED-Illuminated ) but after lots of consideration i took Mischa advice and use S45 500UA VU Meter ( http://www.jjyaudio.com/productview.asp?sid=1491 ) instead. It is much cheaper but still retains the vintage aesthetic.
> 
> 
> i cannot go past 11 o clock, 9 oclock is the ideal volume to me... One more thing to mention, i think VU meter's needle fluctuates depending more on the volume of the DAC rather than the volume of the AMP. so in my case, eventhough the volume of the AMP is 0, the needle still goes up and down whenever i maxed out my DAC.


Oh I thought those were the Don Audio meters, but those S45 look really good! And much cheaper. I believe I could only find the Don Audio at the time my amp was being designed.

Yes, the VU meters fluctuate depending upon the DAC or preamp output.



Xcalibur255 said:


> Sooo....... I feel like I'm the only person here who mainly listens with his eyes closed?


I do too, but sometimes it's nice to see the glow of tubes and meters in a darkened room. Adds to the ambience - especially with a scotch


----------



## Jaeger18 (Feb 24, 2021)

I feel that im incapable of reviewing this glorious amp, so these few paragprahs is going to be more towards sharing my expectation and experience with Mischa and BH from my point of view, so take this with a grain of salt...

Lets start from the person himself.  When it comes to Amplifier, this guy is a walking encyclopedia. He answers all my questions so vividly to the point that i feel wrong to waste his time answering my questions and he is one of the kindest man that ive ever encountered.

After going back and forth deciding to wait for Glenn to build me a GOTL or Blue Halo, i took a leep of faith and ordered BH. I told Mischa what my past amp is lacking (from my point of view) and wish that BH would correct it and be a better fit for my personal taste. 

To be honest, until a week ago i was still skeptical about the BH (aestheticly and how it sounds). But my heart melts when i saw BH for the first time, look at it.. i meaan LOOOK AT IT...

Aesthetic:
i discuss with Mischa about having the 3 capacitor casing painted in black / carbon, but by the end of the day i chose black and am so pleased with the end result...  

SQ:
Long story short.. this sounds way way waaaayyy better than what i expected...
The micro detail is also something to mention, it is very clear / revealing. One of the few things  that my past amp is lacking (for my taste) is its bass and sub bass  (the reason might  be having limited tubes so it cant really elevate to its potential) .BH in the other hand, delivers a good bass and sub bass. it is tight , responsive / quick, you can feel the impact of the bass (not too much but just the right amount). I did mention to Mischa that the bass is like 'Mayweather punching me on the face multiple of times', which i muuuch prefer rather than 'Mike tyson punching me and get KO ed in the 1st round'. 

Second is the volume level, while using my previous amp ive to crank it up to around 5 o clock where as using BH i can only handle up to 11 o clock max ( i usually stay at around 9 o clock). 

Transformer Rolling:
i might as well mention the difference between with and without CINEMAG from my point of view... Mischa did mention that this amp is not  designed to be a balance amp...so in MY CASE, what differs between XLR and RCA is MAINLY with and without CINEMAG transformer.

The funny thing is at the time of the purchase, i didnt even know the usage of CINEMAG, i just thought the word 'CINEMAG' sounds unique so i decided to let Mischa put it into the amp. After i got the amp and tried it THEN i started to realize the change in SQ with / without cinemag. ONLY after noticing the difference in SQ then i decided to search it online, so i feel that im not BIAS at all.

At first i thought it is more lively but later found out that it takes 4V and convert it to 2.2-2.4V RMS which is more than without CINEMAG 2V RMS, which means more volume i guess? After further listen I find it a little bit more natural.

Tube rolling:
Correct me if im wrong but i believe the SQ difference between tube rolling within the same tube family is not going to be that apparent becase of CCS. is it a con? not for my wallet. But some told me that the SQ difference will be more revealing if you use a different kind of tube family... for ex. using kt-88 tube (with kt-88 to 6j5 adapter) in 6j5 socket will have more changes in SQ than using 6j5 tube. ivent play around with different family type of tubes but i will definately tinker around in the future.

6sn7:
-sophia electric 6sn7 
-sylvania 6sn7 
verdict: its too close to differentiate, but i think sophia is a little bit harsher at the highs ever so slightly, but then again ive only used sophia for 30 hrs max so its too soon to say

6j5:
-L63 GEC (2x)
-RCA 6j5 (2x)
verdict: cant tell the difference, maybe needs more time to burn it...  too soon to say 

side note:
-L63 (+-20 hours of use)
-RCA (+-15 hours of use)
-Sylvania (more than 500 hours of use)
-Sophia (+- 40 hours of use)

One last note: the tubes above that ive tested provides a silent black background, and produce a very pleasing SQ.

Final words:
There are lots of talented people that can build a good amp BUT a person that has the ABILITY to build a magnificent amp AND offers a GOOD SERVICE like Mischa provides... is pretty rare to come by these days, im so lucky to hv known him... 

Do i expect more from BLUE HALO? Honestly i expect less than this... so all in all, i can confidently say that this is the better product (out of the two amps that ive tried)  in my case for my personal needs.


Conclusion:
Amp Aesthetic: 10/10
Amp SQ: 10/10
Tube rolling: 7/10 
(if kt-88 to 6j5 adapter arrives  9/10 )
Service: 10/10
money: 10/10
____________ +
money: 0/10
my happiness: 10000000/10
wife's happiness: 0/10


----------



## L0rdGwyn

Jaeger18 said:


> I feel that im incapable of reviewing this glorious amp, so these few paragprahs is going to be more towards sharing my expectation and experience with Mischa and BH from my point of view, so take this with a grain of salt...
> 
> Lets start from the person himself.  When it comes to Amplifier, this guy is a walking encyclopedia. He answers all my questions so vividly to the point that i feel wrong to waste his time answering my questions and he is one of the kindest man that ive ever encountered.
> 
> ...



Very sharp with the VU meters, blue glass, and black caps  great writeup!


----------



## Galapac

Jaeger18 said:


> I feel that im incapable of reviewing this glorious amp, so these few paragprahs is going to be more towards sharing my expectation and experience with Mischa and BH from my point of view, so take this with a grain of salt...
> 
> Lets start from the person himself.  When it comes to Amplifier, this guy is a walking encyclopedia. He answers all my questions so vividly to the point that i feel wrong to waste his time answering my questions and he is one of the kindest man that ive ever encountered.
> 
> ...


 Simply magnificent and elegant. One of these is in my long term wish list. End gamer for sure as a tube amp.


----------



## leftside

Jaeger18 said:


> I feel that im incapable of reviewing this glorious amp, so these few paragprahs is going to be more towards sharing my expectation and experience with Mischa and BH from my point of view, so take this with a grain of salt...
> 
> Lets start from the person himself.  When it comes to Amplifier, this guy is a walking encyclopedia. He answers all my questions so vividly to the point that i feel wrong to waste his time answering my questions and he is one of the kindest man that ive ever encountered.
> 
> ...


Great write up. The bass was also the first thing I noticed with my amp - hence the nickname "Thunder". 

Thanks for the photos. I showed my wife, and said the amp I'm planning for the living room isn't going to be as big as "that amp upstairs" and will look more like yours. It got a semi-approving nod. That's good enough for me


----------



## whirlwind

Jaeger18 said:


> I feel that im incapable of reviewing this glorious amp, so these few paragprahs is going to be more towards sharing my expectation and experience with Mischa and BH from my point of view, so take this with a grain of salt...
> 
> Lets start from the person himself.  When it comes to Amplifier, this guy is a walking encyclopedia. He answers all my questions so vividly to the point that i feel wrong to waste his time answering my questions and he is one of the kindest man that ive ever encountered.
> 
> ...



Nice! Killer amp and some Leopard Woods!
Enjoy 

Ha....I understand the wife's happiness rating!


----------



## raindownthunda

Jaeger18 said:


> I feel that im incapable of reviewing this glorious amp, so these few paragprahs is going to be more towards sharing my expectation and experience with Mischa and BH from my point of view, so take this with a grain of salt...
> 
> Lets start from the person himself.  When it comes to Amplifier, this guy is a walking encyclopedia. He answers all my questions so vividly to the point that i feel wrong to waste his time answering my questions and he is one of the kindest man that ive ever encountered.
> 
> ...


Great impressions and photos! I bet it sounds amazing. 

I love the low light close up photo of the front panel... Very cool old school / retro vibes. This song started playing in my head immediately:


----------



## cdanguyen08

Jaeger18 said:


> I feel that im incapable of reviewing this glorious amp, so these few paragprahs is going to be more towards sharing my expectation and experience with Mischa and BH from my point of view, so take this with a grain of salt...
> 
> Lets start from the person himself.  When it comes to Amplifier, this guy is a walking encyclopedia. He answers all my questions so vividly to the point that i feel wrong to waste his time answering my questions and he is one of the kindest man that ive ever encountered.
> 
> ...


These photos makes me want to put VU meters on my amp! Really dig em.


----------



## Zachik

Jaeger18 said:


> I feel that im incapable of reviewing this glorious amp, so these few paragprahs is going to be more towards sharing my expectation and experience with Mischa and BH from my point of view, so take this with a grain of salt...
> 
> Lets start from the person himself.  When it comes to Amplifier, this guy is a walking encyclopedia. He answers all my questions so vividly to the point that i feel wrong to waste his time answering my questions and he is one of the kindest man that ive ever encountered.
> 
> ...


I way WAY prefer the black (vs. chrome) capacitor covers!
I would love to add an amp by Mischa to my amp collection. Just need to figure out what topology and tubes it would use... 
@Jaeger18 / @A2029 - what are those 2 "plugs?" on the back? between the XLR and RCA jacks?


----------



## A2029 (Feb 23, 2021)

Zachik said:


> I way WAY prefer the black (vs. chrome) capacitor covers!
> I would love to add an amp by Mischa to my amp collection. Just need to figure out what topology and tubes it would use...
> @Jaeger18 / @A2029 - what are those 2 "plugs?" on the back? between the XLR and RCA jacks?


Those are the Cinemag input transformers (optional for XLR input). They take the balanced XLR and convert it to a single ended signal for the amp to use.


----------



## bcowen

> I feel that im incapable of reviewing this glorious amp....



I think you did a *very* capable job.  Thanks for sharing your thoughts....and all the photos!



> wife's happiness: 0/10



The importance of this fades proportionally with every additional year of marriage.


----------



## Zachik

bcowen said:


> The importance of this fades proportionally with every additional year of marriage.


...and then drops to zero when you divorce her!  
(speaking from personal experience)


----------



## Xcalibur255

@Jaeger18 

Congrats on the new amp!  May it bring you years of enjoyment.

Your tube rolling comments kind of struck me, especially that you cannot tell the difference between an RCA and GEC 65J.  I am sold on the benefits of the CCS implementation, but personally I'm hoping that in my amp I'll be able to tell the difference between different 6J5 a *little* bit more than that.  Otherwise I'm going to feel pretty silly for buying so many different kinds.  Then again leaving amp performance on the table just to be able to get more 'flavors' from tube rolling is pretty illogical too so again I agree with the idea of the CCS implementation on the driver stage.

There is something so satisfying about finding *just* the right tube combo that delivers that exact flavor you've been looking for.  It's a shame we can't just eat our cake and have it too here.


----------



## Jaeger18 (Feb 24, 2021)

Xcalibur255 said:


> @Jaeger18
> 
> Congrats on the new amp!  May it bring you years of enjoyment.
> 
> ...




I forgot to mention this, the only tube that has undergo the 'burn in' process is sylvania 6sn7. and for the time being i prefer using sylvania 6n7 compare to sophia.  Every other 6j5, 6sn7 tubes and the amp itself is new, ive only used it for a week.  Its too soon to say.

side note:
-L63 (+-20 hours of use)
-RCA (+-15 hours of use)
-Sylvania (more than 500 hours of use)
- Sophia (+- 40 hours of use)


----------



## chrisdrop

Xcalibur255 said:


> @Jaeger18
> 
> Your tube rolling comments kind of struck me, especially that you cannot tell the difference between an RCA and GEC 65J.  I am sold on the benefits of the CCS implementation, but personally I'm hoping that in my amp I'll be able to tell the difference between different 6J5 a *little* bit more than that.  Otherwise I'm going to feel pretty silly for buying so many different kinds.  Then again leaving amp performance on the table just to be able to get more 'flavors' from tube rolling is pretty illogical too so again I agree with the idea of the CCS implementation on the driver stage.
> 
> There is something so satisfying about finding *just* the right tube combo that delivers that exact flavor you've been looking for.  It's a shame we can't just eat our cake and have it too here.


FYI, whilst I agree that there is a _bigger_ difference swapping tube types, I _believe_ I can tell the difference between different versions of the same tube. Now, the differences are smaller than the GOTL for example, which is very sensitive, but IMO it is there that *little* bit methinks. 

I think the CCS is a solid trade-off. YMMV, caveats, etc.


----------



## bcowen

Xcalibur255 said:


> @Jaeger18
> 
> Congrats on the new amp!  May it bring you years of enjoyment.
> 
> ...


Perhaps this is a glass half empty, glass half full kind of thing.  Maybe a $5 GE would start to sound pretty good.   

(OK, biiiig stretch on that one...)


----------



## Jaeger18

chrisdrop said:


> FYI, whilst I agree that there is a _bigger_ difference swapping tube types, I _believe_ I can tell the difference between different versions of the same tube. Now, the differences are smaller than the GOTL for example, which is very sensitive, but IMO it is there that *little* bit methinks.
> 
> I think the CCS is a solid trade-off. YMMV, caveats, etc.



i started to get into audio gears 1.5 years ago, but eversince my past amp was broken for 6 months + 1 month shipping to and from reparation, i didnt listen to music much. so im considered new to this. so much to learn, maybe for some it is an obvious difference but i might missed it...  sorry if ive misguided all of you for the review that i made. really would like to learn more from this forum...


----------



## Xcalibur255

bcowen said:


> Perhaps this is a glass half empty, glass half full kind of thing.  Maybe a $5 GE would start to sound pretty good.
> 
> (OK, biiiig stretch on that one...)


You don't really want this to be true, do you?


----------



## chrisdrop

Jaeger18 said:


> i started to get into audio gears 1.5 years ago, but eversince my past amp was broken for 6 months + 1 month shipping to and from reparation, i didnt listen to music much. so im considered new to this. so much to learn, maybe for some it is an obvious difference but i might missed it...  sorry if ive misguided all of you for the review that i made. really would like to learn more from this forum...


New is good! Enjoy! I had no desire to refute your comments, just to offer some others. There is no such thing as a professional enjoyer of music - but we all aspire to it!


----------



## bcowen

Xcalibur255 said:


> You don't really want this to be true, do you?


LOL!  No.  I guess I could switch to picking on Philips ECG's, but that's a lot more letters to type on a regular basis.


----------



## Xcalibur255

bcowen said:


> LOL!  No.  I guess I could switch to picking on Philips ECG's, but that's a lot more letters to type on a regular basis.


If you get a coin base GE 6SN7 for Christmas this year just remember it wasn't me.


----------



## Jaeger18 (Feb 24, 2021)

chrisdrop said:


> New is good! Enjoy! I had no desire to refute your comments, just to offer some others. There is no such thing as a professional enjoyer of music - but we all aspire to it!



dont get me wrong chris, ive no intention what so ever or even think that way... all good im just saying so ppl know that im new so that they wont be misguided... thats all nothing more nothing less.. we are all here because we want to know more about Mischa's amp, what it is capable of.. All the comments here really encourage me to discover more about BH... im all ears... trying to improve my listening skill now.


----------



## Marutks

Xcalibur255 said:


> Otherwise I'm going to feel pretty silly for buying so many different kinds.



On the other hand it is good news for our wallets!  No need to buy those expensive Neotrons

https://www.ebay.co.uk/itm/6j5-g-tu...-quad-l63-6sn7-6c5-2a3-b65-valve/254799948487

I have got some 6c5c tubes.  They are NOS/NIB and they dont cost a bomb!


----------



## hpamdr

Marutks said:


> On the other hand it is good news for our wallets!  No need to buy those expensive Neotrons
> 
> https://www.ebay.co.uk/itm/6j5-g-tu...-quad-l63-6sn7-6c5-2a3-b65-valve/254799948487
> 
> I have got some 6c5c tubes.  They are NOS/NIB and they dont cost a bomb!


6c5c or 6s5s are Equivalent to 6C5G family with this nice screen/grid. for 6j5 it is 6c2c/6s2s. _



_


----------



## LoryWiv (Feb 24, 2021)

Xcalibur255 said:


> If you get a coin base GE 6SN7 for Christmas this year just remember it wasn't me.


I think he'd prefer a lump of coal in his stocking. But question: have you guys actually heard this tube or is it just fun to bash GE tubes generall?  I have not heard their 6SN7, but the one GE I do own (7581A) is actually quite good.


----------



## Zachik

LoryWiv said:


> I think he'd prefer a lump of coal in his stocking. But question: have you guys actually heard this tube or is it just fun to bash GE tubes generall?  I have not heard their 6SN7, but the one GE I do own (7581A) is actually quite good.


I strongly suspect that @bcowen actually loves GE tubes! He keeps bashing them, so nobody would buy them, and then *he* buys them for pennies...


----------



## Xcalibur255

LoryWiv said:


> I think he'd prefer a lump of coal in his stocking. But question: have you guys actually heard this tube or is it just fun to bash GE tubes generall?  I have not heard their 6SN7, but the one GE I do own (7581A) is actually quite good.


Joking aside most of the RCA and GE 6SN7s made in the 70s are generally not good sounding.  They tend to undermine some of the primary reasons people go for tubes in the first place by having a rough sound that tends to be particularly ragged in the upper frequencies.  That's only a generalization though.  I will say some of those tall glass coin base tubes *look* pretty neat but while I'd have one on my desk I wouldn't have one in my amp.

There are some tubes from the late era (late 60's onward more or less) that sound good, and they're often very affordable too.  Tubes that don't have a particular reputation attached to them like the "bad boy" Sylvania or the round plate black glass Tung Sol can be good value bets.  Tung Sol and Raytheon tubes from the 60's in particular are nice tubes that can be bought for very little money.


----------



## bcowen

Xcalibur255 said:


> If you get a coin base GE 6SN7 for Christmas this year just remember it wasn't me.


I'll blame it on @Zachik .  Seems logical.     And if I do, I'll let it join the RCA and Sylvania coin bases in the junk tube bin.  They suck too.


----------



## bcowen

Zachik said:


> I strongly suspect that @bcowen actually loves GE tubes! He keeps bashing them, so nobody would buy them, and then *he* buys them for pennies...



This has been working well...please shhhhh.


----------



## bcowen

LoryWiv said:


> I think he'd prefer a lump of coal in his stocking. But question: have you guys actually heard this tube or is it just fun to bash GE tubes generall?  I have not heard their 6SN7, but the one GE I do own (7581A) is actually quite good.


In addition to @Xcalibur255 's comments (that I agree with), there are a lot of GE tubes that don't just sound bad -- they sound _horrid_.  Grating, grainy, screechy, fatiguing....just nasty.  I tend to beat on GE regularly because I've been unfortunate to have purchased some of those tubes (and they're likely late 60's or 70's production). But obviously I haven't heard every GE, and in fact my listening has been confined to only a handful of tube types (and compatibles).  There are some that speak favorably of several GE types that I haven't ever heard, and they could well be wonderful tubes.  And perhaps some that I personally consider horrid some others like a lot, who knows.  To each his own of course, and if they are happy with the sound that's all that really matters.


----------



## Galapac

bcowen said:


> In addition to @Xcalibur255 's comments (that I agree with), there are a lot of GE tubes that don't just sound bad -- they sound _horrid_.  Grating, grainy, screechy, fatiguing....just nasty.  I tend to beat on GE regularly because I've been unfortunate to have purchased some of those tubes (and they're likely late 60's or 70's production). But obviously I haven't heard every GE, and in fact my listening has been confined to only a handful of tube types (and compatibles).  There are some that speak favorably of several GE types that I haven't ever heard, and they could well be wonderful tubes.  And perhaps some that I personally consider horrid some others like a lot, who knows.  To each his own of course, and if they are happy with the sound that's all that really matters.


Do you know if the tubes you mention were possibly made for other electronics back in the day like televisions? It could that these were just not for audio but I am just wondering out of curiosity. When all else fails, you could always set them up for target practice if you had a range.


----------



## bcowen

Galapac said:


> Do you know if the tubes you mention were possibly made for other electronics back in the day like televisions? It could that these were just not for audio but I am just wondering out of curiosity. When all else fails, you could always set them up for target practice if you had a range.


Possibly.  Most of my experience though has been with 6SN7's and 12AU7's (and derivatives) that were primarily used for audio amplification, but they could be used for other applications as well (oscillator, phase inverter, etc).


----------



## Xcalibur255

If you want to hear what might be the worst sounding 6SN7 type tube ever, just track down the GE 6SN7GTB from the early 70's that has the weird extra wire running along the outside of the plate.


----------



## L0rdGwyn

Two GE tubes that stick out in my mind as being of good quality are the GE Five Star 5670 and GE 6BX7GT.  6BX7GT can be hard to find in large quantities, so for many GOTL owners they are the only 6BX7GT used and with pretty good results.  I tried others but they held their own.


----------



## jonathan c

bcowen said:


> This has been working well...please shhhhh.


Remember that tube "alchemy"?:  from GE to WE with a touch from a paintbrush ===>  $0.50 (?) to $4770+ _per tube_...


----------



## hpamdr

Xcalibur255 said:


> Joking aside most of the RCA and GE 6SN7s made in the 70s are generally not good sounding.


You are right for most of 6SN7 GE. But RCA 6SN7 have a specific tone a bit warm some like it ! The drawback is that it is not precise and a micro-details are not revealed. 
This can be sometime not so bad with loosy mp3 format it is like a anti compression hysteresis filter 
I personally like 7N7 (JAN from Sylvania) not so expensive and regular sound quality (bright and precise) but you have to use an adapter.


----------



## chrisdrop

I think my worst set of tubes ever FYI was 6x ~1970s GE coin base 6BL7s. Combining all of @bcowen's love into one tube !

2x GEC5 tin cans are absolutely fine - _good even _(esp compare to most dual triode alts).


----------



## bcowen

hpamdr said:


> I personally like 7N7 (JAN from Sylvania) not so expensive and regular sound quality (bright and precise) but you have to use an adapter.


One of my favorites as well in the tall bottle, full oval mica (top and bottom) version.  An example of a "good" GE below....because it was made by Sylvania.


----------



## Xcalibur255

hpamdr said:


> You are right for most of 6SN7 GE. But RCA 6SN7 have a specific tone a bit warm some like it ! The drawback is that it is not precise and a micro-details are not revealed.
> This can be sometime not so bad with loosy mp3 format it is like a anti compression hysteresis filter
> I personally like 7N7 (JAN from Sylvania) not so expensive and regular sound quality (bright and precise) but you have to use an adapter.


IMO the 60's RCAs exhibit the warm sound you're referring to, but once you get into the 70's they become harsh like the GE.


----------



## hpamdr

Xcalibur255 said:


> IMO the 60's RCAs exhibit the warm sound you're referring to, but once you get into the 70's they become harsh like the GE.


You are right deadhorse I did a quick check and the only RCA 6SN7 left in my collection are VT-231 grey glass from 195x... I've sold all the 6sn7 that i did not liked (_all the one inferior to my taste to the russian 6H8S from the 60 _)


----------



## bcowen

hpamdr said:


> You are right deadhorse I did a quick check and the only RCA 6SN7 left in my collection are VT-231 grey glass from 195x... I've sold all the 6sn7 that i did not liked (_all the one inferior to my taste to the russian 6H8S from the 60 _)


Have you tried the 1951 - 1955 (and some 1956) Foton 6N8S (6H8C)?  They have ribbed plates that were changed to smooth plates sometime during '56, but they are my favorite Russian 6SN7 type.  There's also the Melz 1578 which is excellent, but the genuine ones that are NOS are pretty pricey (~$100 each).


----------



## hpamdr (Feb 26, 2021)

The oldest 6H8C i have are from 58 they really sound great, I also have some from 64,66 which are frankly not so bad but sold all the 70' for almost nothing. I also have a pair from 0880 for the fun 
Those tubes are very stable once hot (no hum, no rfi, autobias of CTH never drop).
_The one with silver paint on the left is from 58, the one on the right from 67.._


----------



## bcowen

hpamdr said:


> The oldest 6H8C i have are from 58 they really sound great, I also have some from 64,66 which are frankly not so bad but sold all the 70' for almost nothing. I also have a pair from 0880 for the fun
> Those tubes are very stable once hot (no hum, no rfi, autobias of CTH never drop).
> _The one with silver paint on the left is from 58, the one on the right from 67.._


Any of the 1950's production dates sound great to me.  The ribbed plate versions sound just a bit better than the smooth plates, but the difference isn't huge.  I wouldn't pay a huge premium for a ribbed versus smooth plate one, but if you run across some '55 or earlier for a decent price, they're worth the grab (IMO). 

1953 with the ribbed plates:


----------



## L0rdGwyn

hpamdr said:


> The oldest 6H8C i have are from 58 they really sound great, I also have some from 64,66 which are frankly not so bad but sold all the 70' for almost nothing. I also have a pair from 0880 for the fun
> Those tubes are very stable once hot (no hum, no rfi, autobias of CTH never drop).
> _The one with silver paint on the left is from 58, the one on the right from 67.._





bcowen said:


> Any of the 1950's production dates sound great to me.  The ribbed plate versions sound just a bit better than the smooth plates, but the difference isn't huge.  I wouldn't pay a huge premium for a ribbed versus smooth plate one, but if you run across some '55 or earlier for a decent price, they're worth the grab (IMO).
> 
> 1953 with the ribbed plates:



It's funny you should mention these tubes.  I have very few 6SN7 left after selling my collection, but needed 6SN7 to use the DarkVoice.  I rummaged through some drawers and found these tubes, three of them, looks like all from 1956, two with ribbed plates, one with smooth plates.  I was pretty impressed by the sound, I have to admit!  And here I thought I was using junk tubes


----------



## leftside

Difficult decision to make today. I had an existing EL6. I also managed to find an EL6 that was sealed in original box. I was going to leave it sealed, but ended up opening it to make a nice pair with my existing EL6. I don't think I've had too many old tubes that were still sealed - and it was a tough decision deciding to open this one up and use it. It's now being used for the first time ever! Would have been in that box for about 70 years.

Interestingly, the pins still looked used - but it must simply be from age. I will clean them later with my Dremel. The cleaner pins (on the right) is a used tube - but pins were cleaned with my Dremel.

These EL6/4699 are great sounding tubes.


----------



## hpamdr

For those tube, you only need to cleanup the external border as only this part will be in contact with the socket...
This is a very nice cleaning job and much nicer like this !

Do you use some fine lapping paste or just the polishing disk ?


----------



## leftside

hpamdr said:


> For those tube, you only need to cleanup the external border as only this part will be in contact with the socket...
> This is a very nice cleaning job and much nicer like this !
> 
> Do you use some fine lapping paste or just the polishing disk ?


https://www.amazon.ca/gp/product/B015PK3BI2


----------



## bcowen

leftside said:


> Difficult decision to make today. I had an existing EL6. I also managed to find an EL6 that was sealed in original box. I was going to leave it sealed, but ended up opening it to make a nice pair with my existing EL6. I don't think I've had too many old tubes that were still sealed - and it was a tough decision deciding to open this one up and use it. It's now being used for the first time ever! Would have been in that box for about 70 years.
> 
> Interestingly, the pins still looked used - but it must simply be from age. I will clean them later with my Dremel. The cleaner pins (on the right) is a used tube - but pins were cleaned with my Dremel.
> 
> These EL6/4699 are great sounding tubes.


Nice!  Do you replace the solder in those pins (one on the right, anyway)?  Looks like a lot of the factory solder is conspicuous by its absence...


----------



## leftside

bcowen said:


> Nice!  Do you replace the solder in those pins (one on the right, anyway)?  Looks like a lot of the factory solder is conspicuous by its absence...


I haven't. But you raise a very good point. I have checked the pins and they seemed firm, but I will double check again.... I have a soldering iron, and know how to solder. Any particular type of solder you recommend for these pins?


----------



## bcowen

leftside said:


> I haven't. But you raise a very good point. I have checked the pins and they seemed firm, but I will double check again.... I have a soldering iron, and know how to solder. Any particular type of solder you recommend for these pins?


Any quality solder with a rosin flux core should work fine, but preferably one that has some silver content to it.  I've used Cardas for years, and @Paladin79 recommended this Kester solder which I like too.  The .020" diameter works very nicely for tube pins.

https://www.amazon.com/gp/product/B004DEUYBY/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1


----------



## leftside

bcowen said:


> Any quality solder with a rosin flux core should work fine, but preferably one that has some silver content to it.  I've used Cardas for years, and @Paladin79 recommended this Kester solder which I like too.  The .020" diameter works very nicely for tube pins.
> 
> https://www.amazon.com/gp/product/B004DEUYBY/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1


Great thanks


----------



## hpamdr (Mar 2, 2021)

bcowen said:


> Any quality solder with a rosin flux core should work fine, but preferably one that has some silver content to it. I've used Cardas for years, and @Paladin79 recommended this Kester solder which I like too. The .020" diameter works very nicely for tube pins.





Spoiler: removed



I'm using this cardas equivalent 3% silver professional grade from a known brand. _(you should get it from farnell instead of amz)_

// the kester is for sure a good product easy to work with but it contain lead.


---- Edited
*@A2029 Misha () is right and I missed that re-soldering pin need to match old soldering material pre rohs*.. Another advantage is that fusion temp is lower <= 180° C instead of >= 220.


----------



## A2029

I'd recommend either a good rosin core 63/37 solder, or the 62/36/2 that bcowen suggested. Back in the day ROHS (lead free) requirements were not in place, so it's more likely that they were using a lead based solder (either 60/40 or 63/37). You don't want to mix a lead free solder into the lead based solder as it can give very poor joints and much higher temperature required for the solder to flow.

Also recommended putting a small bit of flux into the pin hole, as that will help the solder flow more easily and produce a better solder joint. You want an electronics rosin flux such as this: https://www.amazon.ca/SRA-Soldering-Products-Rosin-2-Ounce/dp/B008ZIV85A


----------



## Galapac

Is it true in a pinch you can use Vasoline as flux? I'm not that cheap and have never used it but was wondering if that was true or BS.


----------



## A2029 (Mar 2, 2021)

Galapac said:


> Is it true in a pinch you can use Vasoline as flux? I'm not that cheap and have never used it but was wondering if that was true or BS.


Hmm, never heard of that before. I'd not recommend it and I lean towards it being BS as oils (e.g. even oils from your skin) are seen as contaminants to a proper solder joint that can affect the joint quality.


----------



## Zachik

Galapac said:


> Is it true in a pinch you can use Vasoline as flux? I'm not that cheap and have never used it but was wondering if that was true or BS.





A2029 said:


> Hmm, never heard of that before. I'd not recommend it and I lean towards it being BS as oils (e.g. even oils from your skin) are seen as contaminants to a proper solder joint that can affect the joint quality.



In a pinch, I would recommend the oil left on the fryer from the morning bacon!  🤣 















*(I am just kidding - please do NOT do it!!!!!)*


----------



## Galapac

..Firing up my amp takes on a new meaning..._what's that bacony smell?  _
Sorry for the derailment_, _please back to the subject of 1101 Audio custom crafted headphone amps...


----------



## Marutks (Mar 3, 2021)

My BH amp arrived today.

- Lundahl power transformer.
- Goldpoint attenuator.
- Kiwame resistors.
- Vishay RN55/60 resistors.
- Jupiter Copper capacitors.
- Upgraded tube sockets.


----------



## bcowen

Marutks said:


> My BH amp arrived today.
> 
> - Lundahl power transformer.
> - Goldpoint attenuator.
> ...


Nice!!!!!


----------



## whirlwind

Marutks said:


> My BH amp arrived today.
> 
> - Lundahl power transformer.
> - Goldpoint attenuator.
> ...


 Very nice....killer cans too!


----------



## UntilThen

whirlwind said:


> Very nice....killer cans too!


Is that all you notice?  The amp caught my attention first.


----------



## raindownthunda

Marutks said:


> My BH amp arrived today.
> 
> - Lundahl power transformer.
> - Goldpoint attenuator.
> ...


Very nice setup - congrats! Are those Brimar 6C5G tubes?


----------



## Marutks

yes, they are 6C5G Brimars


----------



## whirlwind

UntilThen said:


> Is that all you notice?  The amp caught my attention first.


Yeah the amp first, then the killer cans to go with it.


----------



## UntilThen

whirlwind said:


> Yeah the amp first, then the killer cans to go with it.


Apologies I read wrongly.


----------



## Xcalibur255

All I see is a picture full of great things.


----------



## jonathan c

UntilThen said:


> Is that all you notice?  The amp caught my attention first.


I thought that the curtains were A-1 😜


----------



## UntilThen

jonathan c said:


> I thought that the curtains were A-1 😜


Curtains are a class act that's for sure. Did anyone Head-Fi screen go wonky all of a sudden?


----------



## Galapac

UntilThen said:


> Curtains are a class act that's for sure. Did anyone Head-Fi screen go wonky all of a sudden?


Yes...for a bit...server crash or web server upgrade me thinks


----------



## chrisdrop

I think I've posted these tubes before, but they are worth posting again. These are KenRad 76s with 2x Deyan adapters. Whilst the BH sound very good with whatever you pop into it, these are very pleasing and not expensive tubes. As others have suggested, different tube TYPES makes a bigger difference than the variations within a tube (although there are still reasonable differences IMO).


----------



## Zachik

chrisdrop said:


> I think I've posted these tubes before, but they are worth posting again. These are KenRad 76s with 2x Deyan adapters. Whilst the BH sound very good with whatever you pop into it, these are very pleasing and not expensive tubes. As others have suggested, different tube TYPES makes a bigger difference than the variations within a tube (although there are still reasonable differences IMO).


Great... more adapters and tube rabbit holes...   
Just to confirm - those are 76 to 6J5 adapters. Right?


----------



## chrisdrop

Zachik said:


> Great... more adapters and tube rabbit holes...
> Just to confirm - those are 76 to 6J5 adapters. Right?


They are. They are in the lineage 56(wrong voltage)>76>6C5>6J5.


----------



## leftside

Do you really need to add solder to the pins? Here is another I received today NOS. Pins look secure. Precleaned (but already pretty clean as is).


----------



## A2029

leftside said:


> Do you really need to add solder to the pins? Here is another I received today NOS. Pins look secure. Precleaned (but already pretty clean as is).


As long as the pins are secure I wouldn't worry about adding solder. Only if it develops noise down the road would you need to worry about it.


----------



## leftside

A2029 said:


> As long as the pins are secure I wouldn't worry about adding solder. Only if it develops noise down the road would you need to worry about it.


I’m more worried about the pins coming off in the adapter. But these look like they were made like this.


----------



## leftside (Mar 4, 2021)

There are three types of getters with EL34 metal base and siblings. The more “common” (still rare...) type is with solid saucer getter. Next is ring getter. Then there is this one which is like a combo of the two later getters. This one has a solid ring on the inside, and a ring getter on the outside. Hopefully my pictures show them ok. Hurry up Sowter with my transformers - I want to use these tubes in Red Dwarf 😅


----------



## UntilThen

Ah you’re using Sowter too.


----------



## whirlwind

leftside said:


> There are three types of getters with EL34 metal base and siblings. The more “common” (still rare...) type is with solid saucer getter. Next is ring getter. Then there is this one which is like a combo of the two later getters. This one has a solid ring on the inside, and a ring getter on the outside. Hopefully my pictures show them ok. Hurry up Sowter with my transformers - I want to use these tubes in Red Dwarf 😅


Killer


----------



## Marutks

Do you use Verite Closed headphones with the Blue Halo?   What tubes?
I tried my VC with the BH and the noise and hum is too much.   I tried to find some quiet tubes.  
CBS Hytron 5692 is supposed to be quiet but it doesn't help much.  

Are 6N6P tubes better?   I will try them when I get adapters.


----------



## chrisdrop

In the BH, these are all relatively quiet for me: Foton 6n6p, GEC L63 "GT style", GEC 6J5G, Osram 6J5G, Fivre 6J5GT, NU 6P5GT, Mullard 6J5G, Fivre 6C5G, Cossor 6C5G, Brimar 6C5G, Sylvania 12J5GT, Sylvania 6J5GT, Sylvania 6P5G, RCA 6C5,  KenRad 76s, (and in my BH with C3G sockets; Visseaux 6J7, AnM 6J7, EL3N, C3G), and more. The only tubes I think are louder are 6N7* family tubes. Notwithstanding the 6N7*s, it is a quiet OTL amplifier IMO.

"Hum" is often ~50hz mains power noise. In my setup presently - at most I can hear a faint air-like sound that you can only hear with music stopped. You can put a spectral analyser app (like this one) on your phone, shove it in your headphones and see what frequency the noise is. If it is ~50Hz (or even harmonics of) you may be suffering from mains hum. This is a hack, but probably not a bad one to guide your next steps. Battling mains hum, I had some success with a voltage regulator at one point and more success with a regenerator, but these are admittedly non-free options.

Another item, if your amp is on a hard surface, you can see if lifting it up quiets the noise. If it does, springy feet under the amp can help absorb any wobbles. I've only seen this be the case with power transformer wobble due to ... mains noise.

FYI - the Foton 6N6Ps (generally recommended brand of those) are available via eBay but took a long time to arrive from the Russia.

-Chris


----------



## magicman2020

Hey Guys,

In @A2029 Blue Halo, I can confirm what @chrisdrop is saying.  I've tried VR101, 12BH7, 6N6P, 6N1P, 6N23P, Tesla 6922,  Osram L63, Fivre 6J5GT, Fivre 6C5G plus I've ran all these tubes in various triplet combinations with no noise issues. Currently running with a pair of Firve 6C5G's plus a 6N23P riding shotgun. Imo the sound is quite pleasing. 
A fairly wide sound stage. 
Full rich tones with soothing mids, bass is deep and extended with and brings a very realistic slam when called on. The highs are detailed yet rounded enough as to not be fatiguing. YMMV 

The sound is extremely immersive w/amazing 3D EFFECTS and super quiet. 
Now I also use a 1101 Audio Pure Power C2029 power conditioner . That could be the difference maker. 
I would say the worst the noise gets would be like " open air".

Stay safe,

Terry


----------



## leftside

Marutks said:


> Do you use Verite Closed headphones with the Blue Halo?   What tubes?
> I tried my VC with the BH and the noise and hum is too much.   I tried to find some quiet tubes.
> CBS Hytron 5692 is supposed to be quiet but it doesn't help much.
> 
> Are 6N6P tubes better?   I will try them when I get adapters.


The dreaded noise is very frustrating. I've had my share of battles - especially as I have a turntable and tube preamp in the mix. Your  headphones are not particularly sensitive, so they shouldn't be too noisy at all (throw something like the highly sensitive Focal Stellia at a powerful tube amp - and you'll probably get bad results).

Is the noise better/worse during different times of day? Do you have any nearby interference - cell phone for example? Have you tried different cables - power and interconnect? A Tripp Lite Isolator helped one of my (solid state) amps tremendously. Do you know someone else where you can take your amp to try? Other times with my tube gear the noise just disappeared after a certain amount of time.


----------



## Marutks (Mar 13, 2021)

Today I left the amp to heat up / play some music for ~10 hours before listening.
Now almost all noise is gone !  Even on VC the background is barely audible. 

I hope this trick will work with other tubes too.   I am currently running metal base Sylvania 6J5G tubes and a CBS Hytron 5692.


----------



## Marutks

leftside said:


> the highly sensitive Focal Stellia at a powerful tube amp - and you'll probably get bad results).



I had Focal Stellia. It didn't work well even with powerful solid state amps. 
I think it would be fine with my ECP T4 amplifier.  It has zero background noise (like solid state) with all headphones I tried.


----------



## leftside

Marutks said:


> I had Focal Stellia. It didn't work well even with powerful solid state amps.
> I think it would be fine with my ECP T4 amplifier.  It has zero background noise (like solid state) with all headphones I tried.


I reserve using mine with my DAP when in the yard in the summer.


----------



## A2029 (Mar 13, 2021)

Marutks said:


> Do you use Verite Closed headphones with the Blue Halo?   What tubes?
> I tried my VC with the BH and the noise and hum is too much.   I tried to find some quiet tubes.
> CBS Hytron 5692 is supposed to be quiet but it doesn't help much.
> 
> Are 6N6P tubes better?   I will try them when I get adapters.





Marutks said:


> Today I left the amp to heat up / play some music for ~10 hours before listening.
> Now almost all noise is gone !  Even on VC the background is barely audible.
> 
> I hope this trick will work with other tubes too.   I am currently running metal base Sylvania 6J5G tubes and a CBS Hytron 5692.



Glad to hear noise went way down  

Sounds as though the tubes needed some burn in to sound their best. For some true NOS tubes, small amounts of gas may have crept in over the time they were sitting in their boxes. During burn in they will continue to get lower noise as they are burned in more and more (some continue to decrease noise up to the 100-200hr mark). After the burn in, any tube generally takes up to 30mins run time after turn on for it to reach it's settling point and sound best. Also check the tube pins to see if there is oxidation on the pins. With NOS tubes it's usually necessary to use sandpaper to gently sand off all discoloration/oxidation from the pins, followed by isopropyl alcohol (99%) on cotton swabs to remove grease/oils/contamination from the pins. Once sanded/cleaned initially, the tube is usually good for a good long while before it would need sanding/cleaning again.

After burn in, some tubes (because of their design, cathode material, etc.) will naturally have a higher noise floor than others. Tubes such as some of the Russian supertubes (6N6P, 6N1P, 6N23P, 6H30P-DR, etc.) are generally very low noise tubes, which is why they are often used for the output stage of tube DACs. Other tubes that were designed for video or oscilloscope use (e.g. 12BY7/12HL7/12HG7) can also be very low noise and very "linear" when triode strapped as well.

Another possibility is that there may have been some heavy machinery or other device in the area that contaminated the electricity or the ground feeding into your setup. If that was the case then a conditioner/voltage regulator/AC regenerator would help for AC line noise. Ground noise is the real hard one to deal with, as the only things that I can think of trying if there is huge noise on the ground line is to try different wall sockets, or worse comes to worse set up some type of legal alternate grounding scheme (e.g. having a separate ground spike put in and new ground run by a certified electrician).


----------



## chrisdrop

FYI - for Blue Halo owners - I can’t get enough of the Foton 6n6p tubes. The ones I’m using have square getters and they are dead dead silent. Get some adapters and go get em!


----------



## bcowen

chrisdrop said:


> FYI - for Blue Halo owners - I can’t get enough of the Foton 6n6p tubes. The ones I’m using have square getters and they are dead dead silent. Get some adapters and go get em!



Seems that some of them are going up in price a bit.  LOL!

Also, Schiit will be releasing an amp that uses 8 of these puppies in the near future, so best stash up now.    

https://www.head-fi.org/threads/sch...bable-start-up.701900/page-5018#post-16302515


----------



## mordy

bcowen said:


> Seems that some of them are going up in price a bit.  LOL!
> 
> Also, Schiit will be releasing an amp that uses 8 of these puppies in the near future, so best stash up now.
> 
> https://www.head-fi.org/threads/sch...bable-start-up.701900/page-5018#post-16302515


The first ones I got cost $2 incl shipping but that was 10 years ago...


----------



## bcowen

mordy said:


> The first ones I got cost $2 incl shipping but that was 10 years ago...


Seems the the box anodes with square (dimpled) getters are becoming few and far between.  Lots of cheap ones still out there from other factories and later years, but I'm assuming the square mica Fotons are the preferred ones.


----------



## leftside (May 4, 2021)

Thunder into the Abyss. Gets a big thumbs up from me.

Mischa says 2.2 watts into 50 ohms with this amp (and says good job I asked for those massive 170uF output caps!). The Abyss are 47 ohms, so near enough.


----------



## mordy

leftside said:


> Thunder into the Abyss. Gets a big thumbs up from me.


Using this amp, can you switch between different drivers instantly, or do you have to wait for the different drivers to warm up?


----------



## leftside

mordy said:


> Using this amp, can you switch between different drivers instantly, or do you have to wait for the different drivers to warm up?


Need to switch the amp off. Wait a minute. Then select different driver. Then turn amp on again.


----------



## UntilThen

leftside said:


> Thunder into the Abyss. Gets a big thumbs up from me.


Congrats. Will be getting mine soon to partner LCD4 and He1000se.


----------



## leftside (May 4, 2021)

UntilThen said:


> Congrats. Will be getting mine soon to partner LCD4 and He1000se.


I've only had a few hours on the Abyss, but I think you'll find they compliment the LCD4 quite nicely. More thoughts in a few days. I've been keeping my eye on the local used market, and a pair appeared. Don't think I've ever purchased a new set of full sized headphones.


----------



## UntilThen

I've found the LCD4 pairing very well with my 300b amp. Several years ago listening to the then original Abyss 1266 phi with Woo Audio WA5le and Takatsuki tubes was also a very good outcome.

If you find a very good condition Abyss why not but I'll be getting new. More like end of year timeframe though but these timeframes have a notorious way of getting shorter for me. The LCD4 and 2 tube amps are very recent purchases.


----------



## UntilThen

I must say that is a great picture of Abyss on Omega stand on top of your tube amp.

It’s a masterclass shot that only the Sennheiser HE1 can compete.


----------



## leftside

UntilThen said:


> I must say that is a great picture of Abyss on Omega stand on top of your tube amp.
> 
> It’s a masterclass shot that only the Sennheiser HE1 can compete.


Thanks! But honestly it was just a quick snap with the phone.


----------



## UntilThen

leftside said:


> Mischa says 2.2 watts into 50 ohms with this amp (and says good job I asked for those massive 170uF output caps!). The Abyss are 47 ohms, so near enough.


Just saw this. That’s a great coupling.

Your next custom amp will be even better.


----------



## leftside

UntilThen said:


> Just saw this. That’s a great coupling.
> 
> Your next custom amp will be even better.


It's probably not going to be better. Smaller footprint, different design, hopefully passes the WAF - as we'd both like this headphone amp in the living room. And I certainly don't have any more room upstairs for a 3rd headphone amp.


----------



## Velozity (May 5, 2021)

leftside said:


> Thunder into the Abyss. Gets a big thumbs up from me.
> 
> Mischa says 2.2 watts into 50 ohms with this amp (and says good job I asked for those massive 170uF output caps!). The Abyss are 47 ohms, so near enough.



 That's a beast of an amp.  Very nice!  I'm going to be joining the 1101 Audio club this year myself.  Really looking forward to it!


----------



## Zachik

Velozity said:


> I'm going to be joining the 1101 Audio club this year myself. Really looking forward to it!


Awesome! Will be looking forward to hear more... 
I am on Mischa's queue as well


----------



## Marutks

Is it possible to use type 76 tubes in the Blue Halo amplifier  ( with 76 to 6J5 adapters )  ?


----------



## chrisdrop

Yes you can


Marutks said:


> Is it possible to use type 76 tubes in the Blue Halo amplifier  ( with 76 to 6J5 adapters )  ?


----------



## Marutks (May 19, 2021)

The 12 volt heater option in the Blue Halo amp is very useful.  One of my favourite tube combinations is Osram B36 and 12J5GT Sylvania tubes.


----------



## Curtisvill

I will be receiving a White Dwarf and power conditioner from Mischa in the near future, it will be replacing a Liquid Platinum I am currently using. The LP uses 6992 tubes, and with adapters I have been using 6992s as well as 12Au7 and EC88 tubes. The White Dwarf uses 6Sn7 and 6J5 tubes. Mischa is also making for me a 6SN7 to 12AU7/12BH7 and a 6Sn7 to 6922/6DJ8/6N6P/6N1P adapters so I will be able to use some of my current collection.

I would like to explore some of the different 6S7N and 6J5 tubes and am looking for recommendations as I do not have much knowledge about these variants. I would like to purchase some different tubes before the amp arrives so am looking for help or recommendations from the experts.  Any guidance you can offer would be most appreciated. Thanks!


----------



## Zachik

Curtisvill said:


> I would like to explore some of the different 6S7N and 6J5 tubes and am looking for recommendations as I do not have much knowledge about these variants. I would like to purchase some different tubes before the amp arrives so am looking for help or recommendations from the experts. Any guidance you can offer would be most appreciated. Thanks!


I think @chrisdrop is the 6J5 expert, and in fact he has created a thread focusing on those tubes! (plus he's using them in another 1101 Audio amp, the Blue Halo)
https://www.head-fi.org/threads/the-reference-6j5-thread-l63-6c5-12j5-6p5-etc.934653/


----------



## chrisdrop

Zachik said:


> I think @chrisdrop is the 6J5 expert, and in fact he has created a thread focusing on those tubes! (plus he's using them in another 1101 Audio amp, the Blue Halo)
> https://www.head-fi.org/threads/the-reference-6j5-thread-l63-6c5-12j5-6p5-etc.934653/


I can't claim expertise with these (or any) tubes. I'll leave that to people like @leftside and others have much more experience and vast collections. I can claim experience cost accrued to my own humble standard! I do enjoy 6J5-like-tubes as a primary preoccupation in the Blue Halo. There is a reasonable coverage of those tubes on that thread and several knowledgable folks have catalogued  their many and varied experiences.


----------



## Zachik

chrisdrop said:


> I can't claim expertise with these (or any) tubes.


It's the internet - anyone can claim anything!


----------



## chrisdrop

Zachik said:


> It's the internet - anyone can claim anything!


Yes. I DID invent the internet after all (for example - just citing one of my many minor creations).


----------



## mordy

Curtisvill said:


> I will be receiving a White Dwarf and power conditioner from Mischa in the near future, it will be replacing a Liquid Platinum I am currently using. The LP uses 6992 tubes, and with adapters I have been using 6992s as well as 12Au7 and EC88 tubes. The White Dwarf uses 6Sn7 and 6J5 tubes. Mischa is also making for me a 6SN7 to 12AU7/12BH7 and a 6Sn7 to 6922/6DJ8/6N6P/6N1P adapters so I will be able to use some of my current collection.
> 
> I would like to explore some of the different 6S7N and 6J5 tubes and am looking for recommendations as I do not have much knowledge about these variants. I would like to purchase some different tubes before the amp arrives so am looking for help or recommendations from the experts.  Any guidance you can offer would be most appreciated. Thanks!


I assume that you mean 6SN7 (not 6S7N).
The 6J5 is half of a 6SN7 and IMHO the 6J5 sound better. In addition many of the 6J5 family of tubes are much cheaper than the 6SN7 tubes, and often even cheaper in 12V versions if your amp comes with such a switch.
6J5 metal tubes are real bargains och RCA, Tung Sol and Ken-Rad sound very good among others.
6J5GT are straight glass versions and the above brands plus Sylvania are not hard to find and very nice sounding.
The larger ST type 6J5G tubes fetch more money and they have been well covered on the 6J5 thread.
Bottom line: Inexpensive 6J5 tubes will leave you very happy....


----------



## leftside

chrisdrop said:


> I can't claim expertise with these (or any) tubes. I'll leave that to people like @leftside and others have much more experience and vast collections. I can claim experience cost accrued to my own humble standard! I do enjoy 6J5-like-tubes as a primary preoccupation in the Blue Halo. There is a reasonable coverage of those tubes on that thread and several knowledgable folks have catalogued  their many and varied experiences.


Certainly not an expert, but I try and become more knowledgeable all the time. The hive mind is strong over on that thread though!


----------



## Zachik

chrisdrop said:


> I can't claim expertise





leftside said:


> Certainly not an expert


Guys - you're too modest! How will you ever run for president, if you down-play your talent and expertise?? Has to be the other way around... 

Here, I will provide some pointers for your reference:
"Yes, I invented 6J5 tubes. In fact, I discovered vacuum and its benefit for audio amplification!"


----------



## mordy

Fact check: Were you around in 1937 lol?


----------



## Zachik (May 20, 2021)

Edit: removed my off-topic silliness...


----------



## Zachik

I have just booked my flights and hotel for CanJam SoCal (Sep. 25-26)   
Any chance I will be able to (finally) audition one of Mischa's creations?
@A2029 - any idea if one of your amps be there? (or better yet - will YOU be there?)


----------



## Marutks (May 22, 2021)

I have got metal base GEC B36 but it seems to have identical internal structure to brown base Osram B36.
And I think those Westinghouse 12J5GT tubes are rebranded Sylvania tubes ( round plate ).


----------



## OctavianH

chrisdrop said:


> Yes. I DID invent the internet after all (for example - just citing one of my many minor creations).


I hope you have not invented the commercials in the youtube videos. I have a small problem with those.


----------



## magicman2020

leftside said:


> Certainly not an expert, but I try and become more knowledgeable all the time. The hive mind is strong over on that thread though!


I couldn't agree more about this communities collective mind. I guarantee that if you go with consensus winners on here. You will not be disappointed. I know I did. I still get wowed listening to a system I've had since last August. 
A HUGE shoutout  to this amazing Head fi community along with my eternal thanks.


----------



## Marutks

My tube adapters arrived today ( thanks Mischa ).   

6N6P tubes are great,  very quiet.


----------



## Marutks

I decided to try 6080 tubes and I bought this:





This tube makes the Blue Halo amp super quiet.   There is no tube noise whatsoever (like hybrid ECP T4 amp) !

It sounds great with Raytheon 6J5G tubes.   Definitely better than all 6SN7 tubes I have tried.


----------



## A2029

Marutks said:


> I decided to try 6080 tubes and I bought this:
> 
> 
> 
> ...



You can likely run the 6080 alone without the 6J5 tubes as the 6J5s would be pretty much idle when the 6080 is running (6080 tubes are so powerful that they do all the work when run as a combo with other tubes). Generally the most powerful tube (lowest anode/cathode resistance) will do most of the amplification/work when running the amp in combo with the 6SN7 and 6J5 sockets filled.

For a super quiet amp, also try running a pair of 6N6P in the 6J5 sockets via adapters. Try the pair in 6J5 sockets alone (nothing in the 6SN7 socket) or in combo with other tubes in the 6SN7 socket to see what gives good tone/super low noise. You could also use a 6N6P to 6SN7 at the same time (so three 6N6P running at the same time ) . When dual section (dual triode) tubes such as the 6N6P are run the in the 6J5 sockets, the adapters parallel their sections which reduces the anode resistance by half, and cuts down on overall tube noise.

Tubes that have lower amplification factor, or tubes with low anode/cathode resistance, will generally have lower tube noise. Big tubes such as the 6080/6AS7/6BX7/6BL7 have very low anode resistance and most should be very low noise. Tubes such as EL34 also have low anode/cathode resistance and would be very low noise in the Blue Halo. Some other small tubes such as 6C45P, 12BY7/12HG7/12GN7, and others also have quite low anode/cathode resistance despite being small tubes, and should be low noise as well.


----------



## Curtisvill

My White Dwarf will be shipping this week along with the power conditioner Mischa has made for me.  Very excited!


----------



## raindownthunda

Curtisvill said:


> My White Dwarf will be shipping this week along with the power conditioner Mischa has made for me.  Very excited!


Another great looking 1101 amp - congrats! Can’t wait to hear your impressions.


----------



## Curtisvill

My White Dwarf, Pure Power conditioner, and adapters from Mischa have arrived and are currently burring-in. I need to give it some more time before I feel I will be ready to give an honest review, but I am already floored by the musicality of the White Dwarf. When I first fired up the amp there was a low-level hum present that has since disappeared as the burn-in continues. I have ordered a Sylvania 6SN7GT VT-231 which should be here tomorrow so I can listen to the amp as designed, currently I am running a 6N6P using one of Mischa’s adapters. Picture of the amp is on a table next to my desk where the amp is burning-in and will be moved to its permanent spot in the next week. Updates to follow.

John


----------



## HPAholic

Just been added to the waitlist and hopefully the days fly by, Thanks Mischa ...


----------



## leftside

Been a little quiet on here, so thought I'd make a post. Had a friend come over yesterday evening and we were listening on the V6 Thunder. Loaded her up with 6 5998 tubes and 2 6N7G and plugged in the hard to drive LCD4 and Abyss at the same time. The LCD4 and Abyss are quite hard to drive headphones and the Abyss also has low impedance. There's no way an OTL amp should be able to drive these two headphones so well at the same time - but it does. Thanks again Mischa!


----------



## bcowen

leftside said:


> Been a little quiet on here, so thought I'd make a post. Had a friend come over yesterday evening and we were listening on the V6 Thunder. Loaded her up with 6 5998 tubes and 2 6N7G and plugged in the hard to drive LCD4 and Abyss at the same time. The LCD4 and Abyss are quite hard to drive headphones and the Abyss also has low impedance. There's no way an OTL amp should be able to drive these two headphones so well at the same time - but it does. Thanks again Mischa!


LOL!  When I first read that, I thought your friend was female and you gave her 6 5998 tubes.  I was wanting to be your friend too.


----------



## leftside

bcowen said:


> LOL!  When I first read that, I thought your friend was female and you gave her 6 5998 tubes.  I was wanting to be your friend too.


Haha yes I've read it again. I'll leave it as is  You'd need to be a particularly nice female for me to hand over 6 5998 tubes - so that rules you out my friend.


----------



## UntilThen

leftside said:


> Been a little quiet on here, so thought I'd make a post. Had a friend come over yesterday evening and we were listening on the V6 Thunder. Loaded her up with 6 5998 tubes and 2 6N7G and plugged in the hard to drive LCD4 and Abyss at the same time. The LCD4 and Abyss are quite hard to drive headphones and the Abyss also has low impedance. There's no way an OTL amp should be able to drive these two headphones so well at the same time - but it does. Thanks again Mischa!



I came here because I thought your new KT88 / EL34 amp is ready.


----------



## leftside

UntilThen said:


> I came here because I thought your new KT88 / EL34 amp is ready.


We're working on it  Just my "bright idea" of having a copper case that is causing a hold up. But, if we can figure this out, this will also provide a nice option for future potential buyers.


----------



## UntilThen

You're going to need racks soon.  For your headphone amps.


----------



## UntilThen

Headroom is important. My LCD4 sound different with my new amp compared to other amps I've before. The 300b amp also drives it very well. I will know about Abyss 1266 TC when I get it to demo at home .... very soon.


----------



## whirlwind

leftside said:


> Been a little quiet on here, so thought I'd make a post. Had a friend come over yesterday evening and we were listening on the V6 Thunder. Loaded her up with 6 5998 tubes and 2 6N7G and plugged in the hard to drive LCD4 and Abyss at the same time. The LCD4 and Abyss are quite hard to drive headphones and the Abyss also has low impedance. There's no way an OTL amp should be able to drive these two headphones so well at the same time - but it does. Thanks again Mischa!


Ha 6 5998 tubes....that is some serious tube output power!


----------



## maxpudding

whirlwind said:


> Ha 6 5998 tubes....that is some serious tube output power!



expensive heaters!


----------



## whirlwind

maxpudding said:


> expensive heaters!


Yeah....like $900 worth of glass!


----------



## UntilThen

whirlwind said:


> Yeah....like $900 worth of glass!



$900 worth of glass is still less than a pair of GEC KT88. Granted they won't sound the same but it's all in the name of this hobby. A pair of WE 300b is $1500. Tubes are expensive these days but Leftside would have had them for cheap a long time ago.

The right tube combination in a well crafted amp will sound out of this world. I'm running Philips Miniwatt EL11 with Tung Sol 6550 now and it's the best way to spend Friday night.


----------



## whirlwind

UntilThen said:


> $900 worth of glass is still less than a pair of GEC KT88. Granted they won't sound the same but it's all in the name of this hobby. A pair of WE 300b is $1500. Tubes are expensive these days but Leftside would have had them for cheap a long time ago.
> 
> The right tube combination in a well crafted amp will sound out of this world. I'm running Philips Miniwatt EL11 with Tung Sol 6550 now and it's the best way to spend Friday night.


I am aware of all of this….regardless what he paid for them they are still $900 for 6 of them


----------



## leftside

maxpudding said:


> expensive heaters!


Can get a bit warm in the summer! Cooler temps here now tho after a blistering June-August.


----------



## leftside

whirlwind said:


> I am aware of all of this….regardless what he paid for them they are still $900 for 6 of them


How about 6 WE421A or GEC 6AS7G?  I don't mind running the TungSols as I have backups, but to be honest, I typically run 6 Mullard 6080. Those can still be found for good prices and I have a good stash of used ones.


----------



## Zachik

leftside said:


> I don't mind running the TungSols as I have backups, but to be honest, I typically run 6 Mullard 6080. Those can still be found for good prices and I have a good stash of used ones.


I guess you were "rewarded" for entering the game early on (relatively speaking)...


----------



## leftside

Zachik said:


> I guess you were "rewarded" for entering the game early on (relatively speaking)...


I've got to know a few of the guys who have been around for a long time. Some guys were hording tubes when people were moving to transistors as they worked in the tube business and simply preferred the sound of tube gear. I guess similar to the guys hording vinyl when CD's came out. Some of these guys are apparently sitting on crates of unopened still sealed highly desirable tubes such as GEC KT88...


----------



## Zachik

leftside said:


> I've got to know a few of the guys who have been around for a long time. Some guys were hording tubes when people were moving to transistors as they worked in the tube business and simply preferred the sound of tube gear. I guess similar to the guys hording vinyl when CD's came out. Some of these guys are apparently sitting on crates of unopened still sealed highly desirable tubes such as GEC KT88...


If you find any of these guys, and they are not too greedy - let me know!


----------



## LoryWiv

Zachik said:


> If you find any of these guys, and they are not too greedy - let me know!


Yes. me as well!!!


----------



## leftside

I haven't managed to prise anything from them. I guess we may end up seeing some turn up on eBay.


----------



## magicman2020

Hi Guys,
It's been a while since my last post. I hope everyone is finally returning to a more normal daily routine and that your friends and family are safe.
As for my musical odyssey, I'm a Blue Halo fanboy for life. The synergy of it , plus my Rockna Wavelight and my ZMF VC ltd (Lepardwood ) is nothing short of heaven. Yes gentlemen, I'm drawing a hard line in the sand. I challenge you to pay the sticker price I did and experience it for yourself, and tell me I'm wrong.  Anyway, my musical journey took another turn for the better , as I went back to Mischa for an end game headphone cable, and some more adapters for my Blue Halo . I have to say , the RCA 12HG7(12HG7 adapter into 6J5 sockets)  coupled with a 6N23P riding shotgun is my personal favourite glass combo in a Blue Halo. The sound is clear, very 3 dimensional , wide sound stage,  while improving everything without making the sound fatiguing with is amazing giving this level of realism.  More info on the headphone cable to follow.


----------



## magicman2020

@A2029 I will tell you sir, you are an amazing person to deal with. You are a certified genius and have created a masterpiece and I'm just grateful to know you. thank you Mischa!


----------



## bcowen

leftside said:


> I've got to know a few of the guys who have been around for a long time. Some guys were hording tubes when people were moving to transistors as they worked in the tube business and simply preferred the sound of tube gear. I guess similar to the guys hording vinyl when CD's came out. Some of these guys are apparently sitting on crates of unopened still sealed highly desirable tubes such as GEC KT88...


I first "discovered" NOS tubes with some RCA 5AR4's.  $1 each at a radio store with racks full of tubes (long since out of business).   I thought I splurged buying 6 of them even though my amp only used a pair.    Too bad I was such a tube newb at the time....no telling what treasures they had that I didn't even know to look for.


----------



## jonathan c

bcowen said:


> I first "discovered" NOS tubes with some RCA 5AR4's.  $1 each at a radio store with racks full of tubes (long since out of business).   I thought I splurged buying 6 of them even though my amp only used a pair.    Too bad I was such a tube newb at the time....no telling what treasures they had that I didn't even know to look for.


Just think of how your audio journey would have gone had your first tubes been GE…


----------



## bcowen

jonathan c said:


> Just think of how your audio journey would have gone had your first tubes been GE…


LOL!  Probably would have saved me a bunch of money because I'd have switched to solid state and never looked back.


----------



## jonathan c

bcowen said:


> LOL!  Probably would have saved me a bunch of money because I'd have switched to solid state and never looked back.


However, just as Afghanistan sits on a world key supply of lithium, you sit on a world key supply of Fotons…🤨…


----------



## bcowen

jonathan c said:


> However, just as Afghanistan sits on a world key supply of lithium, you sit on a world key supply of Fotons…🤨…


No such thing as 'too many' Fotons.


----------



## leftside

jonathan c said:


> However, just as Afghanistan sits on a world key supply of lithium, you sit on a world key supply of Fotons…🤨…


Funnily enough, I've been investing in lithium companies for quite a few years, and have learnt a lot about what it takes to establish a battery grade lithium mine online from scratch. Even in countries with established infrastructure like Argentina, Canada and Australia it takes many years to do. And then you also need a chemical plant to convert the lithium into carbonate or hydroxide which can then be used in EV batteries. These plants are very expensive. Companies around the world (VW, Ford, GM, etc and of course Tesla) are spending billions building battery plants right now, but the same amount of thought/money hasn't gone into developing the actual mines that will supply the chemical processing plants that in turn will supply the battery plants... So, no chance the Taliban are ever going to mine that lithium (it's nowhere near as simple as say coal or iron ore), but the danger might be they get a little help from the Chinese, and then there is a chance they will have mines up and running by the end of the decade. Sorry for the OT post, but I guess some might find it mildly interesting.


----------



## jonathan c

leftside said:


> Funnily enough, I've been investing in lithium companies for quite a few years, and have learnt a lot about what it takes to establish a battery grade lithium mine online from scratch. Even in countries with established infrastructure like Argentina, Canada and Australia it takes many years to do. And then you also need a chemical plant to convert the lithium into carbonate or hydroxide which can then be used in EV batteries. These plants are very expensive. Companies around the world (VW, Ford, GM, etc and of course Tesla) are spending billions building battery plants right now, but the same amount of thought/money hasn't gone into developing the actual mines that will supply the chemical processing plants that in turn will supply the battery plants... So, no chance the Taliban are ever going to mine that lithium (it's nowhere near as simple as say coal or iron ore), but the danger might be they get a little help from the Chinese, and then there is a chance they will have mines up and running by the end of the decade. Sorry for the OT post, but I guess some might find it mildly interesting.


…and if the Chinese provide assistance in building/maintaining the lithium extraction infrastructure, the Chinese will be the preferred / designated customers…


----------



## maxpudding

leftside said:


> Funnily enough, I've been investing in lithium companies for quite a few years, and have learnt a lot about what it takes to establish a battery grade lithium mine online from scratch. Even in countries with established infrastructure like Argentina, Canada and Australia it takes many years to do. And then you also need a chemical plant to convert the lithium into carbonate or hydroxide which can then be used in EV batteries. These plants are very expensive. Companies around the world (VW, Ford, GM, etc and of course Tesla) are spending billions building battery plants right now, but the same amount of thought/money hasn't gone into developing the actual mines that will supply the chemical processing plants that in turn will supply the battery plants... So, no chance the Taliban are ever going to mine that lithium (it's nowhere near as simple as say coal or iron ore), but the danger might be they get a little help from the Chinese, and then there is a chance they will have mines up and running by the end of the decade. Sorry for the OT post, but I guess some might find it mildly interesting.



The CCP has started investing in Afghanistan in 2016 through their Belt and Road Initiative. The BRI has been proposed to many Asian countries with the promise of large "investments" from Chinese companies; some countries have started letting them in, building infrastructures and whatnot; however, those are just "loans" (some countries have succumbed to these debt-traps, or in other words, economic colonization). So returning to Afghanistan, the CCP government would need a stable Afghanistan if they ever wanted to get that lithium or any other natural resources that the country can offer. I'm not sure what's the endgame in Afghanistan, seems like it would be another country that will be plagued with decades of civil wars.

Anyways, I digress...looking forward to seeing more discussion about the amps!


----------



## jonathan c

maxpudding said:


> The CCP has started investing in Afghanistan in 2016 through their Belt and Road Initiative. The BRI has been proposed to many Asian countries with the promise of large "investments" from Chinese companies; some countries have started letting them in, building infrastructures and whatnot; however, those are just "loans" (some countries have succumbed to these debt-traps, or in other words, economic colonization). So returning to Afghanistan, the CCP government would need a stable Afghanistan if they ever wanted to get that lithium or any other natural resources that the country can offer. I'm not sure what's the endgame in Afghanistan, seems like it would be another country that will be plagued with decades of civil wars.
> 
> Anyways, I digress...looking forward to seeing more discussion about the amps!


Ampghanistan?


----------



## maxpudding

jonathan c said:


> Ampghanistan?



 The country that had an excess of Russian-made tubes, and now US-made tubes. Next up, Chinese-made tubes.


----------



## jonathan c

maxpudding said:


> The country that had an excess of Russian-made tubes, and now US-made tubes. Next up, Chinese-made tubes.


Ampghanistan….future home of the lithium battery external power supply for……….


----------



## mvneufeld

Curtisvill said:


> My White Dwarf, Pure Power conditioner, and adapters from Mischa have arrived and are currently burring-in. I need to give it some more time before I feel I will be ready to give an honest review, but I am already floored by the musicality of the White Dwarf. When I first fired up the amp there was a low-level hum present that has since disappeared as the burn-in continues. I have ordered a Sylvania 6SN7GT VT-231 which should be here tomorrow so I can listen to the amp as designed, currently I am running a 6N6P using one of Mischa’s adapters. Picture of the amp is on a table next to my desk where the amp is burning-in and will be moved to its permanent spot in the next week. Updates to follow.
> 
> John


Would love to hear your impression of the White Dwarf now that you've had it for a while.  
Thinking of pulling the trigger myself.


----------



## leftside

A Red Dwarf is starting to form over the Western skies.


----------



## Zachik

Very pretty case!!!
Can you tell more about the amp?


----------



## leftside

Zachik said:


> Very pretty case!!!
> Can you tell more about the amp?


2 * EL34/KT66/related and a whole bunch of other power tubes like 4654/EL11/etc with adapters. Mischa has come up with a clever design where I just need to select the most appropriate setting of 30mA or 60mA and the amp will take care of the rest/auto bias.
2 * 6J5 drivers
1 * 6SN7 driver 

Select 6J5 or 6SN7. If I didn't already have a bunch of great 6SN7 I would have just gone with 6J5.

More to come...


----------



## Zachik

leftside said:


> Mischa has come up with a clever design


Mischa tends to do that...


----------



## magicman2020

I'm not sure if the word is out. However, As the first Blue Halo, A2029 , power conditioner , and adaptors owner, I will stamp it here. Mischa is the absolute best person to deal with both in terms of his customer service, however in terms of his audio designs that are absolutely ground-breaking . He firmly stands behind everything he does and sadly no @A2029 isnt paying me a cent for my raving about is work over a year after I've received it.


----------



## Zachik

magicman2020 said:


> Mischa is the absolute best person to deal with both in terms of his customer service, however in terms of his audio designs that are absolutely ground-breaking


I have been working with Mischa for several months now, on a new ground-breaking design (details will follow when the amp is finally built) and I can absolutely agree that Mischa is:
a. Very patient!!! Sorry Mischa for the hundreds of questions... or so it feels... 
b. Very smart and outside-the-box thinker, which enables:
c. Open to crazy (and I mean wildly crazy) ideas  
Half the crazy (or was it just insane) ideas for my amp started with "that cannot be done". When I asked "why?", Mischa explained patiently, but added "let me think some more about it", followed (the next day) by "I think I have a solution to implement that idea" and concluded by "Yeah, I can do it" 

Cannot wait for my number to come up in Mischa's queue. As promised, details WILL follow, but that would take a little while...


----------



## leftside

Looking forward to it. Great to see all these options coming from all the custom amp builders on here.


----------



## mvneufeld

Still hoping some White Dwarf owners will contribute their impressions. A lot has been posted on the Blue Halo but precious little on the White Dwarf...


----------



## maxpudding (Sep 17, 2021)

Zachik said:


> I have been working with Mischa for several months now, on a new ground-breaking design (details will follow when the amp is finally built) and I can absolutely agree that Mischa is:
> a. Very patient!!! Sorry Mischa for the hundreds of questions... or so it feels...
> b. Very smart and outside-the-box thinker, which enables:
> c. Open to crazy (and I mean wildly crazy) ideas
> ...


Agreed, I think Mischa is a very talented amp builder. My discussion with him also started with one crazy idea, and after a few days he came back and presented a solution to me that could work. He’s a very humble guy and I would imagine that he’ll be very busy making these great amps in the coming months.


----------



## magicman2020 (Sep 17, 2021)

mvneufeld said:


> Still hoping some White Dwarf owners will contribute their impressions. A lot has been posted on the Blue Halo but precious little on the White Dwarf...


@mvneufeld I'm sorry I can't speak directly to the characteristics of a White Dwarf. I know if it's designed by @A2029 it's done so with the goal of a low impedance headphone amp in mind, and done to perfection like its big brother the Blue Halo amp that's designed specifically for high impedance headphones. I'm a strong believer in synergy. 1101 Audio = outstanding components Period . End of Story ,and sadly no Mischa is still not paying me for the love. lol


----------



## magicman2020

mvneufeld said:


> Still hoping some White Dwarf owners will contribute their impressions. A lot has been posted on the Blue Halo but precious little on the White Dwarf...


@mvneufeld I'm sorry that I can't speak directly to the characteristics of a White Dwarf. All I know if it's designed as
 the lower impedance phones. I'm a strong believer in synergy.


----------



## whirlwind

leftside said:


> Looking forward to it. Great to see all these options coming from all the custom amp builders on here.


Could not agree more.


----------



## Xcalibur255

leftside said:


> A Red Dwarf is starting to form over the Western skies.


Is this an extra piece that wraps around the chassis?

Seeing other people's ideas I'm starting to regret being so boring and "inside the box" with mine...... but I'm sure it'll blow my shirt off the first time I hear it and none of those thoughts will matter anymore after that.


----------



## leftside (Sep 17, 2021)

Xcalibur255 said:


> Is this an extra piece that wraps around the chassis?


Yes. And it only matters to me as I'm trying to match the color scheme of my DAC.


----------



## kamui

leftside said:


> Yes. And it only matters to me as I'm trying to match the color scheme of my DAC.


Do you have a Holo May then?


----------



## whirlwind

kamui said:


> Do you have a Holo May then?


I think @leftside is referring to this
https://www.lampizator.com/the-golden-atlantic-1


----------



## leftside

whirlwind said:


> I think @leftside is referring to this
> https://www.lampizator.com/the-golden-atlantic-1


Close. But it’s actually the earlier version - the regular R2R (non TRP version) Golden Atlantic I have in the living room.

Mischa has done an amazing job working with that copper case. I don’t think either of us realized how difficult copper is to work with. Big shout out to Lampizator and the guys in Poland for sharing some tips!


----------



## UntilThen

leftside said:


> A Red Dwarf is starting to form over the Western skies.



and the chassis is ready. Looking good.  I suppose the Sowter output transformers will be colour match with it.


----------



## leftside

UntilThen said:


> and the chassis is ready. Looking good.  I suppose the Sowter output transformers will be colour match with it.


I think that might be a “bit much”. Sticking with silver Sowter.


----------



## mvneufeld (Sep 19, 2021)

Decided to go with the Blue Halo. I'm happy to say I've just joined the queue!


----------



## UntilThen

leftside said:


> I think that might be a “bit much”. Sticking with silver Sowter.


Holy Toledo looks just like my Sowters


----------



## Marutks (Sep 20, 2021)

5687 Tung Sol and 2 x 6N6P tubes


----------



## Galapac

Very nice. New amp?


----------



## Marutks

Galapac said:


> Very nice. New amp?



New tubes.   I bought this amp in March.


----------



## Xcalibur255

5687 tubes are nice.  Never understood why more amps aren't designed around the "space era" tubes.


----------



## raindownthunda

Marutks said:


> New tubes.   I bought this amp in March.


What do you think of the 5687 tubes compared to the other types you’ve tried?


----------



## Marutks

raindownthunda said:


> What do you think of the 5687 tubes compared to the other types you’ve tried?



They are super quiet, like other small tubes in the Blue Halo.   I haven't noticed any sonic differences though (compared to 6N6P).


----------



## A2029

Marutks said:


> They are super quiet, like other small tubes in the Blue Halo.   I haven't noticed any sonic differences though (compared to 6N6P).



For your sonic impressions of the 5687, was that with the 6N6P in the 6J5 sockets at the same time?

The 6N6P are more powerful tubes, so they'll likely dictate most of the tone when combined with the 5687 in the 6SN7 position. If you run just the 5687 (nothing in the 6J5 sockets), it should give you more of the 5687 flavor


----------



## L0rdGwyn

Near-equivalent to the 5687 is the Philips E182CC, might be another good one to try if it is compatible.


----------



## Marutks

A2029 said:


> For your sonic impressions of the 5687, was that with the 6N6P in the 6J5 sockets at the same time?



Yes


----------



## A2029

L0rdGwyn said:


> Near-equivalent to the 5687 is the Philips E182CC, might be another good one to try if it is compatible.



Yup, compatible in the 5687 adapter


----------



## leftside

Someone outdid V6 Thunder. Here is a V16:
https://www.facebook.com/groups/VTAgroup/permalink/10157858477836333/


----------



## UntilThen

Eight EL34 per channel.  I link a picture of it sometime ago.


----------



## bcowen

leftside said:


> Someone outdid V6 Thunder. Here is a V16:
> https://www.facebook.com/groups/VTAgroup/permalink/10157858477836333/


Beauty is of course in the eye of the beholder, but to these eyes that looks more like a science project than a serious amplifier. 

I'll go with the (un)V-24's.


----------



## Xcalibur255

I think I'll stick with single-ended and high sensitivity speakers myself.

I guess it would save on house heating costs in the winter at least.


----------



## bcowen

Xcalibur255 said:


> *I think I'll stick with single-ended and high sensitivity speakers myself.*
> 
> I guess it would save on house heating costs in the winter at least.


Me too.  Those were from days gone by, but still one of the few I wish I _hadn't _sold.  My Jota amp will play more than loud enough at any sane decibel level, but the Cary's offered insanity which I've always found compelling.


----------



## jonathan c

leftside said:


>


“Warning!….Danger!….Danger!….”


----------



## edward1900

where can i buy this 1101 audio amp


----------



## cdanguyen08 (Oct 10, 2021)

edward1900 said:


> where can i buy this 1101 audio amp


Shoot @A2029 a PM! Real easy to work with and quick to respond. Here's the a link to Mischa stuff as well https://www.1101audio.com/?i=1


----------



## magicman2020

leftside said:


> Someone outdid V6 Thunder. Here is a V16:
> https://www.facebook.com/groups/VTAgroup/permalink/10157858477836333/


Now that's audio-Hemi ! Wow!!


----------



## leftside

Red Dwarf is now flying through the western skies. Hopefully touchdown will be before the weekend. Will report back more when it arrives. 

Here are a few interesting features:

- Custom Sowter transformers with 22/88/198/352 impedance settings.
- There is a constant current source/ anode resistor switch. The driver tubes can be either fed through the CCS (flat, super low distortion loadline), or through Kiwame anode resistors (more angled loadline, more harmonic distortion)
- The dynamic bias on the amp is really neat; it starts the amp somewhere around -70 on the grid which allows the cathode to develop a good space charge before the power tubes start conducting anything - a soft start for the anode current. The bias current switch can be toggled when the amp is on, and it takes around a minute for it to adjust between the two settings. So you can try the two current settings for sound (for power tubes that can take the two settings) without having to turn off the amp


----------



## Zachik

leftside said:


> - There is a constant current source/ anode resistor switch. The driver tubes can be either fed through the CCS (flat, super low distortion loadline), or through Kiwame anode resistors (more angled loadline, more harmonic distortion)


...and I thought my upcoming (still under wraps) amp will be the 1st to have that super cool feature!
Cannot wait to read your impressions once you get the amp, hopefully before the weekend


----------



## cdanguyen08

Mischa cranking em out! Can't wait for my build as well!


----------



## leftside

cdanguyen08 said:


> Mischa cranking em out! Can't wait for my build as well!


A KT150 amp. Looking forward to seeing that.


----------



## leftside

Zachik said:


> ...and I thought my upcoming (still under wraps) amp will be the 1st to have that super cool feature!
> Cannot wait to read your impressions once you get the amp, hopefully before the weekend


Looking forward to seeing your amp as well!


----------



## cdanguyen08

leftside said:


> A KT150 amp. Looking forward to seeing that.


I took inspiration from you and @Xcalibur255 ! Haven't had a tube amp since Little Dot Mkiii many years ago.


----------



## Zachik

leftside said:


> Looking forward to seeing your amp as well!


That makes 2 of us!! (paying attention, Mischa? )


----------



## bcowen

leftside said:


> Red Dwarf is now flying through the western skies. Hopefully touchdown will be before the weekend. Will report back more when it arrives.
> 
> Here are a few interesting features:
> 
> ...


Sweet!  Look forward to your impressions.

I like Kiwames.  Now that Rikens are no longer made and the remaining stocks are drying up and becoming stupidly priced, the Kiwames are a worthy replacement.


----------



## L0rdGwyn

bcowen said:


> Sweet!  Look forward to your impressions.
> 
> I like Kiwames.  Now that Rikens are no longer made and the remaining stocks are drying up and becoming stupidly priced, the Kiwames are a worthy replacement.



Agreed, it will be sad when Rikens are gone.  Kiwame's (or KOA Spear) are very good.  Stay away from Takman, they are garbage.


----------



## UntilThen

leftside said:


> Red Dwarf is now flying through the western skies. Hopefully touchdown will be before the weekend. Will report back more when it arrives.
> 
> Here are a few interesting features:
> 
> ...



FedEx or DHL? I'm waiting for the unboxing.


----------



## tubebuyer2020

L0rdGwyn said:


> ...Kiwame's (or KOA Spear) are very good...



Is there a good source for them? Mouser doesn't stock many values.


----------



## L0rdGwyn

tubebuyer2020 said:


> Is there a good source for them? Mouser doesn't stock many values.



Not sure where you're located @tubebuyer2020 , but Hificollective in the UK and Parts Connexion in Canada both stock Kiwame.  There are other online shops as well (e.g., DIY Hifi Supply, Acoustic-Dimension).


----------



## tubebuyer2020

L0rdGwyn said:


> Not sure where you're located @tubebuyer2020 , but Hificollective in the UK and Parts Connexion in Canada both stock Kiwame.  There are other online shops as well (e.g., DIY Hifi Supply, Acoustic-Dimension).



Thank you for taking a moment to list all of them. Yes, I have been buying some from Hifi Collective. Unfortunately, all of these places are capitalising on the dwindling supply to various degrees of greediness. No hate, though! It's a fair game and I would do the same. There was a time apparently a few years ago when these could have been bought at 10 cent per item. At least these still are not tube sort of prices .


----------



## bcowen

tubebuyer2020 said:


> Thank you for taking a moment to list all of them. Yes, I have been buying some from Hifi Collective. Unfortunately, all of these places are capitalising on the dwindling supply to various degrees of greediness. No hate, though! It's a fair game and I would do the same. There was a time apparently a few years ago when these could have been bought at 10 cent per item. At least these still are not tube sort of prices .


Yeah I know what you mean.  I saw an Ebay listing not too long ago for 1k, 1/2 watt Rikens for $50 *each*.  LOL!  The Rikens were (comparatively) expensive even when being produced at around $2 a pop IIRC, but the only time I've spent long green on resistors was some cast graphite Duelands and I'm reasonably confident I'll never do that again.


----------



## whirlwind

leftside said:


> Red Dwarf is now flying through the western skies. Hopefully touchdown will be before the weekend. Will report back more when it arrives.
> 
> Here are a few interesting features:
> 
> ...


constant current source/ anode resistor switch....very cool. Can't wait to hear your impressions with this feature.


----------



## leftside

I’ve been listening for a couple of hours now with the LCD4. Things that spring to mind are hard-hitting, clarity and detail. Loving it so far. It might be a long night…

Only tried the CCS setting so far, but have changed the impedance to all 4 settings for the LCD4. The LCD4 loses control of the bass on lower impedance settings. It’s quite noticeable. Just goes to show how important it is to match your headphones with the correct amp.


----------



## leftside

Also gets cat approval. Wife hasn’t seen it yet, but even if she doesn’t like it, she’s been out voted 2-1.


----------



## L0rdGwyn

leftside said:


> I’ve been listening for a couple of hours now with the LCD4. Things that spring to mind are hard-hitting, clarity and detail. Loving it so far. It might be a long night…
> 
> Only tried the CCS setting so far, but have changed the impedance to all 4 settings for the LCD4. The LCD4 loses control of the bass on lower impedance settings. It’s quite noticeable. Just goes to show how important it is to match your headphones with the correct amp.



Looks excellent, congrats to both you and @A2029 !


----------



## leftside (Oct 14, 2021)

I managed to catch the copper color better in the previous photo,  but here is a front shot. The copper color is definitely deeper and more radiant than in this photo.


----------



## Xcalibur255

It looks stunning!  Congrats!  Those are the best kind of long nights.


----------



## UntilThen

Looks compact and matching with your dac colour. Good choice of EL34 metal base to start off with. 

Congrats !


----------



## raindownthunda

leftside said:


> I’ve been listening for a couple of hours now with the LCD4. Things that spring to mind are hard-hitting, clarity and detail. Loving it so far. It might be a long night…
> 
> Only tried the CCS setting so far, but have changed the impedance to all 4 settings for the LCD4. The LCD4 loses control of the bass on lower impedance settings. It’s quite noticeable. Just goes to show how important it is to match your headphones with the correct amp.


The copper chassis is stunning. Very cool looking amp. Well done, Mischa. Congrats and enjoy!


----------



## cdanguyen08

leftside said:


> I managed to catch the copper color better in the previous photo,  but here is a front shot. The copper color is definitely deeper and more radiant than in this photo.


Beautiful shot of a beautiful amp and dac. My dream dac! One day!


----------



## magicman2020

leftside said:


> I managed to catch the copper color better in the previous photo,  but here is a front shot. The copper color is definitely deeper and more radiant than in this photo.


Congrats @leftside , I'm telling you the whole look with the copper , meters, glass, and tubes just hits the bullseye! Well done. I'm looking forward to some more sonic details because I know @A2029 stuff sounds every bit as good as it looks .


----------



## UntilThen

leftside said:


> I’ve been listening for a couple of hours now with the LCD4. Things that spring to mind are hard-hitting, clarity and detail. Loving it so far. It might be a long night…
> 
> Only tried the CCS setting so far, but have changed the impedance to all 4 settings for the LCD4. The LCD4 loses control of the bass on lower impedance settings. It’s quite noticeable. Just goes to show how important it is to match your headphones with the correct amp.


LCD4 needs an amp with drive to make it sound great. Looks like Red Dwarf hits it off at the starting block and hard hitting, clarity and details will suit the Audeze to a T.

Let me know later how your Abyss respond to the amp.


----------



## maxpudding

The copper chassis looks awesome! Congratulations  I am sure there would be many more great amps to come


----------



## leftside

I tried out the CCS/RES setting. Definitely noticed a difference. RES I found warmer, "dirtier" and boomier bass. I prefer the CCS setting, but will try the RES setting again in the future for sure. I will hear more tube differences through the RES setting.

Also noticed a difference when using the 30mA bias setting on tubes that can handle 60mA. It's not just the volume that increased. The tubes seemed to handle the music better and sounds were more coherent.

Here's a different look. This time with brown base tubes. I don't think I have anything new to report on the tubes I've used so far. Sonic and performance characteristics of tubes like Fivre 6SN7, Sylvania 6SN7 metal base (Sylvania 6J5 metal base are a far cheaper option - look for ones with similar construction to the 6SN7), MWT/Osram 6J5, Tungsol BGRP are pretty well known and sound no different in this amp. The bass on TS BGRP is still killer (and again similar construction 6J5 are well worth a try).


----------



## cdanguyen08

leftside said:


> I tried out the CCS/RES setting. Definitely noticed a difference. RES I found warmer, "dirtier" and boomier bass. I prefer the CCS setting, but will try the RES setting again in the future for sure. I will hear more tube differences through the RES setting.
> 
> Also noticed a difference when using the 30mA bias setting on tubes that can handle 60mA. It's not just the volume that increased. The tubes seemed to handle the music better and sounds were more coherent.
> 
> Here's a different look. This time with brown base tubes. I don't think I have anything new to report on the tubes I've used so far. Sonic and performance characteristics of tubes like Fivre 6SN7, Sylvania 6SN7 metal base (Sylvania 6J5 metal base are a far cheaper option - look for ones with similar construction to the 6SN7), MWT/Osram 6J5, Tungsol BGRP are pretty well known and sound no different in this amp. The bass on TS BGRP is still killer (and again similar construction 6J5 are well worth a try).


That glow from the meters with that Chassis!


----------



## UntilThen

leftside said:


> I tried out the CCS/RES setting. Definitely noticed a difference. RES I found warmer, "dirtier" and boomier bass. I prefer the CCS setting, but will try the RES setting again in the future for sure. I will hear more tube differences through the RES setting.
> 
> Also noticed a difference when using the 30mA bias setting on tubes that can handle 60mA. It's not just the volume that increased. The tubes seemed to handle the music better and sounds were more coherent.
> 
> Here's a different look. This time with brown base tubes. I don't think I have anything new to report on the tubes I've used so far. Sonic and performance characteristics of tubes like Fivre 6SN7, Sylvania 6SN7 metal base (Sylvania 6J5 metal base are a far cheaper option - look for ones with similar construction to the 6SN7), MWT/Osram 6J5, Tungsol BGRP are pretty well known and sound no different in this amp. The bass on TS BGRP is still killer (and again similar construction 6J5 are well worth a try).



When you get tired of that KT77, can you send them to me?

Fabulous tubes you have there. What can you report about noise hum from the amp or is it non-existent?


----------



## whirlwind

Love that color brother!


----------



## leftside

whirlwind said:


> Love that color brother!


Thanks bud! We were working on materials, design and finishing for quite a while. Mischa found a great place nearby to help out. Obvious "borrowing" of ideas from Lampizator...


----------



## leftside (Oct 15, 2021)

UntilThen said:


> When you get tired of that KT77, can you send them to me?
> 
> Fabulous tubes you have there. What can you report about noise hum from the amp or is it non-existent?


Noise and hum externally and through the headphones is basically non-existent with good tubes even at very loud volumes. I got three of those KT77 from the same guy a couple of years ago. Good price for the three - for KT77 anyway. One has a broken spigot, one tests low (but still works fine) and two of them "only" test around 80%. Perfect for me - so I don't feel guilty using them!


----------



## maxpudding (Oct 15, 2021)

leftside said:


> I tried out the CCS/RES setting. Definitely noticed a difference. RES I found warmer, "dirtier" and boomier bass. I prefer the CCS setting, but will try the RES setting again in the future for sure. I will hear more tube differences through the RES setting.
> 
> Also noticed a difference when using the 30mA bias setting on tubes that can handle 60mA. It's not just the volume that increased. The tubes seemed to handle the music better and sounds were more coherent.
> 
> Here's a different look. This time with brown base tubes. I don't think I have anything new to report on the tubes I've used so far. Sonic and performance characteristics of tubes like Fivre 6SN7, Sylvania 6SN7 metal base (Sylvania 6J5 metal base are a far cheaper option - look for ones with similar construction to the 6SN7), MWT/Osram 6J5, Tungsol BGRP are pretty well known and sound no different in this amp. The bass on TS BGRP is still killer (and again similar construction 6J5 are well worth a try).


I know CCS, but what is the RES setting? And what does the RES setting do actually?


----------



## A2029

maxpudding said:


> I know CCS, but what is the RES setting? And what does the RES setting do actually?



Res setting stands for resistor. There are two ways to feed the anode of the driver tubes in his amp. The first is the constant current source (CCS) that acts to linearize the loadline on the driver tubes, leading to lower distortion and more consistent high performance across tube rolls. The second method is a more traditional method of feeding the driver tube anodes with resistors (in this case Kiwame resistors). Feeding the driver tube anodes with resistors instead of the CCS leads to less linear tube operation, with an angled loadline, more distortion (primarily second harmonic, leading to warmer and less controlled sound in most cases) and much more variability between tube rolls.


----------



## L0rdGwyn

The clear topcoat on the copper looks fantastic!  And matches those micanol base tubes very well.  Getting all of that sorted must have been a lot of work.


----------



## UntilThen

leftside said:


> Noise and hum externally and through the headphones is basically non-existent with good tubes even at very loud volumes.



Excellent. A quiet amp with a pitch black background is the hallmark of a great tube amp. Congrats once again. This amp will respond to changes in driver and power tubes and you have the most enviable collection of great NOS tubes.


----------



## leftside

maxpudding said:


> I know CCS, but what is the RES setting? And what does the RES setting do actually?


Fun to use RES for tube rolling. There is no denying for me tho that CCS is better. Everything is simply tighter and more coherent.


----------



## maxpudding

leftside said:


> Fun to use RES for tube rolling. There is no denying for me tho that CCS is better. Everything is simply tighter and more coherent.


All in all, an excellent amp, thanks for the photos and review!


----------



## leftside

maxpudding said:


> All in all, an excellent amp, thanks for the photos and review!


I’ll try and give more of a sound review in a few weeks time. Will also compare to the Thunder V6 (can’t believe it’s been 2 years since I received that amp from Mischa) and the Glenn 300B.


----------



## whirlwind

leftside said:


> Fun to use RES for tube rolling. There is no denying for me tho that CCS is better. Everything is simply tighter and more coherent.


@L0rdGwyn  put CCS load in my OTL when he put 6/12J5 sockets in it and I feel the same way...more coherent is a good description.


----------



## whirlwind

A2029 said:


> Res setting stands for resistor. There are two ways to feed the anode of the driver tubes in his amp. The first is the constant current source (CCS) that acts to linearize the loadline on the driver tubes, leading to lower distortion and more consistent high performance across tube rolls. The second method is a more traditional method of feeding the driver tube anodes with resistors (in this case Kiwame resistors). Feeding the driver tube anodes with resistors instead of the CCS leads to less linear tube operation, with an angled loadline, more distortion (primarily second harmonic, leading to warmer and less controlled sound in most cases) and much more variability between tube rolls.


Really nice feature.


----------



## L0rdGwyn

A2029 said:


> Res setting stands for resistor. There are two ways to feed the anode of the driver tubes in his amp. The first is the constant current source (CCS) that acts to linearize the loadline on the driver tubes, leading to lower distortion and more consistent high performance across tube rolls. The second method is a more traditional method of feeding the driver tube anodes with resistors (in this case Kiwame resistors). Feeding the driver tube anodes with resistors instead of the CCS leads to less linear tube operation, with an angled loadline, more distortion (primarily second harmonic, leading to warmer and less controlled sound in most cases) and much more variability between tube rolls.





leftside said:


> Fun to use RES for tube rolling. There is no denying for me tho that CCS is better. Everything is simply tighter and more coherent.





whirlwind said:


> @L0rdGwyn  put CCS load in my OTL when he put 6/12J5 sockets in it and I feel the same way...more coherent is a good description.



@Monsterzero


----------



## Monsterzero

L0rdGwyn said:


> @Monsterzero


After hearing your amp, I know you know what you're doing. I dont mind 2nd order harmonics though. 
As long as it doesnt come out sounding like a solid state amp with 0.0001 THD, I say go for it.


----------



## leftside

Monsterzero said:


> After hearing your amp, I know you know what you're doing. I dont mind 2nd order harmonics though.
> As long as it doesnt come out sounding like a solid state amp with 0.0001 THD, I say go for it.


There's still some 2nd order harmonics. I think Mischa was going to post these, but as the question has been asked, I'm going to beat him to it!


----------



## HPAholic

Added to the wait list on July 28, 2021 and it's only been 3 months   Mischa hurry up and take my $$$$$, lol


----------



## leftside

One thing I've noticed is how revealing this amp is. I think this is a good thing, but it does no favors to poor recordings. The detail extraction is superb. Now it's got me thinking about comparisons to the V6. I wasn't going to compare both amps for a few more weeks, but I'm having a strong urge to take the Red Dwarf upstairs for a little shoot out. And it's raining all weekend here... I think me, the amps, and my trusty Crafty+ vape are going to be in for a fun afternoon. Got to do some exercise first, and then I'll be at it.


----------



## A2029 (Oct 16, 2021)

Monsterzero said:


> After hearing your amp, I know you know what you're doing. I dont mind 2nd order harmonics though.
> As long as it doesnt come out sounding like a solid state amp with 0.0001 THD, I say go for it.





leftside said:


> There's still some 2nd order harmonics. I think Mischa was going to post these, but as the question has been asked, I'm going to beat him to it!



So this is a good time to show an interesting comparison between an OTL tube amp, and a transformer coupled SET amp. The transformer coupled SET amp has harmonic distortion from driver tube, power tube, and from the magnetic coupling within the output transformer. An OTL amp forgoes the output transformers, so only has harmonic distortion added from the driver tube and power tube, so no transformer distortion. The tubes in an OTL generally don't have to amplify as much as in a transformer coupled SET amp as well (less voltage swing), which generally means lower distortion. A CCS was used for the driver tube in both these cases below.

Below is a measurement for a 1 khz sine wave showing the harmonic distortion from a 6SN7 running in a Blue Halo amplifier (zero feedback, class A OTL amp). Notice how at this volume level (-29.2dBFS, corresponding to approx 80dB listening volume in a pair of HD650 headphones), there is the big fundamental frequency ("1"), but the harmonic frequencies are way down and almost not visible. 2nd harmonic ("2") is down at only 0.0031% and third harmonic ("3") at 0.0016%. There is what appears to be an 8th harmonic that you see ("8") at 0.0067% and even a 16th harmonic, but those are one thing that can happen when the windows mixer messes with the audio signal - A good reason to use exclusive mode in your audio software  






Here is the same Blue Halo amp, but using EL34's for the amplification duty. Notice how with this bigger power tube being used in driver tube duty, 2nd harmonic jumps up to 0.035%, a 10X jump in 2nd harmonic distortion. 3rd harmonic stays almost non-existent at 0.0017%:







Now compare these graphs above to approximately the same voltage level coming from a transformer coupled SET amp and I think the difference is pretty obvious. Much more 2nd, 3rd, and 4th harmonic. To re-iterate, this is a result of the more voltage swing from the driver tube, the power tube, and the interaction of that voltage swing in the magnetic coupling of the signal within the output transformer.







All of this to say that OTL amps in general have much lower distortion overall than a transformer coupled SET amp. The good thing is that a zero feedback OTL amp is still a 2nd harmonic producing tube amp and doesn't produce nearly as much 3rd and higher harmonics, so it still gives the tube tonality/smoothness. A CCS will reduce overall harmonics, but definitely won't eliminate the 2nd harmonic, so shouldn't sound like a solid state amp. OTL amps are a great addition to a tube amp arsenal as they give a different presentation than the transformer coupled SET amps. Transformer coupled SET amps will, on average, give more of the harmonic richness and transformer tone to the audio output. Both "delicious flavors" (lol!) and with slightly different tonality, but still tube amps with primarily 2nd harmonics, and low higher harmonics.

A problem with certain solid state amps (though certainly not all) is that with too much feedback, they have the potential to eliminate their low order harmonic distortion (2nd, 3rd, 4th, etc.), but some of them retain their higher order harmonics (7th, 8th, 9th, 10th, ...., etc.). The problem with this is that higher order distortion can't be "masked" by the fundamental frequency, so it more readily able to be heard, and IMO leads to the steely/hard quality that you get in some solid state.


----------



## Monsterzero

A2029 said:


> So this is a good time to show an interesting comparison between an OTL tube amp, and a transformer coupled SET amp. The transformer coupled SET amp has harmonic distortion from driver tube, power tube, and from the magnetic coupling within the output transformer. An OTL amp forgoes the output transformers, so only has harmonic distortion added from the driver tube and power tube, so no transformer distortion. The tubes in an OTL generally don't have to amplify as much as in a transformer coupled SET amp as well (less voltage swing), which generally means lower distortion. A CCS was used for the driver tube in both these cases below.
> 
> Below is a measurement for a 1 khz sine wave showing the harmonic distortion from a 6SN7 running in a Blue Halo amplifier (zero feedback, class A OTL amp). Notice how at this volume level (-29.2dBFS, corresponding to approx 80dB listening volume in a pair of HD650 headphones), there is the big fundamental frequency ("1"), but the harmonic frequencies are way down and almost not visible. 2nd harmonic ("2") is down at only 0.0031% and third harmonic ("3") at 0.0016%. There is what appears to be an 8th harmonic that you see ("8") at 0.0067% and even a 16th harmonic, but those are one thing that can happen when the windows mixer messes with the audio signal - A good reason to use exclusive mode in your audio software
> 
> ...


Thanks Mischa for the explanation. Is it safe to extrapolate from your comments then that there is less tube influence going on? In other words will the difference between a GE and GEC tube be less noticeable?


----------



## A2029

Monsterzero said:


> Thanks Mischa for the explanation. Is it safe to extrapolate from your comments then that there is less tube influence going on? In other words will the difference between a GE and GEC tube be less noticeable?



When using CCS over the driver tube, the differences between different brands of the same tube type are minimized, but still there to a degree. E.g. I still find that some of my cheap (well used, low measuring) 6J5's that I have still sound harsher/thinner. So IMO the CCS doesn't get rid of inherent strengths/weaknesses that certain tubes may have, it just makes the tube perform at their best, whatever the best it can manage happens to be - In the case of my 58% measuring Marconi, it tries it's best, haha


----------



## LoryWiv

A2029 said:


> So this is a good time to show an interesting comparison between an OTL tube amp, and a transformer coupled SET amp. The transformer coupled SET amp has harmonic distortion from driver tube, power tube, and from the magnetic coupling within the output transformer. An OTL amp forgoes the output transformers, so only has harmonic distortion added from the driver tube and power tube, so no transformer distortion. The tubes in an OTL generally don't have to amplify as much as in a transformer coupled SET amp as well (less voltage swing), which generally means lower distortion. A CCS was used for the driver tube in both these cases below.
> 
> Below is a measurement for a 1 khz sine wave showing the harmonic distortion from a 6SN7 running in a Blue Halo amplifier (zero feedback, class A OTL amp). Notice how at this volume level (-29.2dBFS, corresponding to approx 80dB listening volume in a pair of HD650 headphones), there is the big fundamental frequency ("1"), but the harmonic frequencies are way down and almost not visible. 2nd harmonic ("2") is down at only 0.0031% and third harmonic ("3") at 0.0016%. There is what appears to be an 8th harmonic that you see ("8") at 0.0067% and even a 16th harmonic, but those are one thing that can happen when the windows mixer messes with the audio signal - A good reason to use exclusive mode in your audio software
> 
> ...


 Thank you for an explanation that the non-audio engineers amongst can still (mostly) understand, very clear and helpful.


----------



## Xcalibur255

leftside said:


> Fun to use RES for tube rolling. There is no denying for me tho that CCS is better. Everything is simply tighter and more coherent.


Mischa did a really good job of explaining to me what is going on electrically with the tubes while using a CCS load.  Once I understood better I lost interest in the Res switch option because I knew I would only ever listen to it in CCS mode.  For somebody who has more fun tube rolling than I do though it certainly is a fun feature.


----------



## bcowen

leftside said:


> I’ve been listening for a couple of hours now with the LCD4. Things that spring to mind are hard-hitting, clarity and detail. Loving it so far. It might be a long night…
> 
> Only tried the CCS setting so far, but have changed the impedance to all 4 settings for the LCD4. The LCD4 loses control of the bass on lower impedance settings. It’s quite noticeable. Just goes to show how important it is to match your headphones with the correct amp.


Sweet!!!


----------



## bcowen

leftside said:


> Also gets cat approval. Wife hasn’t seen it yet, but even if she doesn’t like it, she’s been out voted 2-1.


Cats get 2 votes by default, so it's actually 3-1.


----------



## Xcalibur255

Monsterzero said:


> Thanks Mischa for the explanation. Is it safe to extrapolate from your comments then that there is less tube influence going on? In other words will the difference between a GE and GEC tube be less noticeable?


Don't think of it as getting "less" of something you value (i.e. less tube flavor).  Think of it more as maximizing the potential for the tube itself to perform as best as it possibly can.  What you get less of is bad stuff like high order distortion that makes the sound worse.


----------



## Zachik

Xcalibur255 said:


> Don't think of it as getting "less" of something you value (i.e. less tube flavor).  Think of it more as maximizing the potential for the tube itself to perform as best as it possibly can.  What you get less of is bad stuff like high order distortion that makes the sound worse.


GE vs. GEC become more of a: GE vs. GEc


----------



## bcowen

Zachik said:


> GE vs. GEC become more of a: GE vs. GEc


Wait...Mischa said it just makes a tube perform at its best.

In other news, a 1972 Ford Pinto performing at its best was still not a very desirable car.


----------



## Monsterzero

leftside said:


> Also gets cat approval. Wife hasn’t seen it yet, but even if she doesn’t like it, she’s been out voted 2-1.


Damn dude, you have some killer gear!! Congrats!


----------



## A2029

A2029 said:


> When using CCS over the driver tube, the differences between different brands of the same tube type are minimized, but still there to a degree. E.g. I still find that some of my cheap (well used, low measuring) 6J5's that I have still sound harsher/thinner. So IMO the CCS doesn't get rid of inherent strengths/weaknesses that certain tubes may have, it just makes the tube perform at their best, whatever the best it can manage happens to be - In the case of my 58% measuring Marconi, it tries it's best, haha



I should mention that along with the above explanation, there are times when the warmer, slightly boomier sound that you get from the RES (resistor) setting (tube dependent of course) actually works well for certain types of listening experiences. E.g. during burn in of the amp I flipped the switch over to the RES setting to try out when playing Battlefield 2042 with some friends. I paired it with a Tung-sol 6SN7GTB as the driver tube and KT150's for power tubes on the high current (60mA) setting, and using HD650 headphones. That was one heck of an experience; very good 3D soundscape - gunshots with good body, satisfying thwacks of bullets hitting soil and trees around me, and cannon blasts that had really good texture/grunt. Would likely pair well with certain types of music as well based on listener preference, e.g. EDM, etc.


----------



## leftside

I had a fun and interesting afternoon comparing the amps. Certainly didn't need the heating on in that room with the 3 amps on.

I started with the Abyss. The OTL V6 was warmer and I could feel the bass more. The SET Red Dwarf is more detailed. Glenn SET 300B is more airy. Red Dwarf is slightly more forward. Pinpoint accuracy with the Red Dwarf. With the Aybss, both the 300B are more detailed and clearer than the V6. I prefer the 300B and Red Dwarf with the Abyss. Remember the V6 is OTL, and in theory OTL amps have no right to play well with such a low impedance planar headphone like the Abyss. Mischa says it does so well because of the massive Clarity caps. Most people think this amp has output transformers due to the 3 cases on top, but those cases are covering massive Clarity caps.

Next onto the LCD4. Remember to turn the volume down if switching between Abyss and LCD4... I thought all 3 amps were closer together in sound signature with the LCD4. V6 fills the headphone with sound, whereas 300B and Red Dwarf are a bit more selective where the sound goes. Touch of bloom with V6 as I noticed with the Abyss. All amps have outstanding bass with the Abyss, V6 slightly warmer, Red Dwarf goes slightly deeper. Wouldn't say I have much of a preference between amps when using the LCD4.

I was using Tungsol 6SN7 BGRP and GEC L63 drivers in both the Red Dwarf and V6. I swapped power tubes from Neotron 6L6G to Spanish Marconi 6F6 in the Red Dwarf and I definitely noticed a warmer sound. 

All amps are dead silent when the preamp was set to the max. I couldn't even hear a faint sound of air/hiss which I was surprised about. Ive found the SOTM device works well here. USB straight from the PC or laptop generated quite a lot of noise (but only at very loud levels).

What pairing would I listen to the most? Probably Red Dwarf with Abyss and warmer tubes. But, at no point this afternoon did I think "this particular amp has to go, it's not as good as the others".


----------



## Xcalibur255

That's a lot of happiness in just a couple of photos right there.


----------



## maxpudding

Wonderful! I always wondered whether an OTL system would be a good pair with the abyss, given what we know about its driver and sound signature. Well done Mischa 👍🏼


----------



## whirlwind

leftside said:


> I had a fun and interesting afternoon comparing the amps. Certainly didn't need the heating on in that room with the 3 amps on.
> 
> I started with the Abyss. The OTL V6 was warmer and I could feel the bass more. The SET Red Dwarf is more detailed. Glenn SET 300B is more airy. Red Dwarf is slightly more forward. Pinpoint accuracy with the Red Dwarf. With the Aybss, both the 300B are more detailed and clearer than the V6. I prefer the 300B and Red Dwarf with the Abyss. Remember the V6 is OTL, and in theory OTL amps have no right to play well with such a low impedance planar headphone like the Abyss. Mischa says it does so well because of the massive Clarity caps. Most people think this amp has output transformers due to the 3 cases on top, but those cases are covering massive Clarity caps.
> 
> ...


Thanks for the write up    
I am guessing you are self biasing these tubes ?


----------



## chrisdrop

leftside said:


> I had a fun and interesting afternoon comparing the amps. Certainly didn't need the heating on in that room with the 3 amps on.
> 
> I started with the Abyss. The OTL V6 was warmer and I could feel the bass more. The SET Red Dwarf is more detailed. Glenn SET 300B is more airy. Red Dwarf is slightly more forward. Pinpoint accuracy with the Red Dwarf. With the Aybss, both the 300B are more detailed and clearer than the V6. I prefer the 300B and Red Dwarf with the Abyss. Remember the V6 is OTL, and in theory OTL amps have no right to play well with such a low impedance planar headphone like the Abyss. Mischa says it does so well because of the massive Clarity caps. Most people think this amp has output transformers due to the 3 cases on top, but those cases are covering massive Clarity caps.
> 
> ...


Sorry for your suffering with all of that sweet tube gear. We are here for you 

All seems awesome. Enjoy the heck out of it. Thanks for sharing your experiences.


----------



## leftside

whirlwind said:


> Thanks for the write up
> I am guessing you are self biasing these tubes ?


No tube rolling on the Glenn 300B... So, I just set the bias on the top and leave it. V6 - no need to bias the tubes - there is a 5998/6080 switch. On Red Dwarf, I gave Mischa a list of all the power tubes I wanted to have run in the amp. Originally, we were going to have a crazy 10 position switch to choose bias point for each tube, but Mischa came up with a design where just a switch for 30mA and 60mA was sufficient. All tubes listed  at 60mA can also be tried at 30mA.


----------



## musicman59

leftside said:


> I had a fun and interesting afternoon comparing the amps. Certainly didn't need the heating on in that room with the 3 amps on.
> 
> I started with the Abyss. The OTL V6 was warmer and I could feel the bass more. The SET Red Dwarf is more detailed. Glenn SET 300B is more airy. Red Dwarf is slightly more forward. Pinpoint accuracy with the Red Dwarf. With the Aybss, both the 300B are more detailed and clearer than the V6. I prefer the 300B and Red Dwarf with the Abyss. Remember the V6 is OTL, and in theory OTL amps have no right to play well with such a low impedance planar headphone like the Abyss. Mischa says it does so well because of the massive Clarity caps. Most people think this amp has output transformers due to the 3 cases on top, but those cases are covering massive Clarity caps.
> 
> ...


A lot of glass between those 3 amplifiers.
They look awesome! Congrats!!


----------



## magicman2020

musicman59 said:


> A lot of glass between those 3 amplifiers.
> They look awesome! Congrats!!


Am I looking in a mirror ? LOL


----------



## leftside

A couple of people have asked me about what some of the components are, like what transformers, etc. I thought I might as well post them here:

Sowter Output custom transformers * 2    
Lundahl LL1650 Transformer
Khozmo Ladder attenuator    
Kiwame Resistors  
Miflex 0.47uF KPCU pair (Coupling Cap)
High voltage polypropylene oil capacitors (2 x 15uF)
2 - 68000uF Capacitors 
+ lots of other resistors, diodes, caps ,etc


----------



## musicman59 (Oct 19, 2021)

I have dibs on the avatar since I have it in the forum since 2004 and own the real thing framed…


----------



## jonathan c

musicman59 said:


> I have dibs on the avatar since I have it in the forum since 2004 and own the real thing framed…


I still have an Advent 201 cassette player with Maxell chromium cassette tape (both in hibernation…)


----------



## magicman2020

musicman59 said:


> I have dibs on the avatar since I have it in the forum since 2004 and own the real thing framed…


Its unreal at how close the accounts are , even the names are so similar. I chose it as Maxell tapes were my cassette tape of choice back in the day and I was on this site to find a sound that blew me away. Happy to report that this community did not let me down. So where do I send the royalty fees for usage ?


----------



## musicman59

magicman2020 said:


> Am I looking in a mirror ? LOL





magicman2020 said:


> Its unreal at how close the accounts are , even the names are so similar. I chose it as Maxell tapes were my cassette tape of choice back in the day and I was on this site to find a sound that blew me away. Happy to report that this community did not let me down. So where do I send the royalty fees for usage ?


Ha ha ha! A beer at one of the CanJam events will do!

My first cassette deck was back in 1980. It was the top of the line Yamaha. It was the most expensive part of my equipment. I did that because I loved to record my own mixed tapes.
Then I upgraded to a Nakamichi CR-5A. I used Maxell and TDK Chrome. The best one I tried was the TDK that had the frame of aluminum and plastic covers.

Then I upgraded to DAT and got a Denon deck and a Sony DAT car deck.


----------



## magicman2020

musicman59 said:


> Ha ha ha! A beer at one of the CanJam events will do!
> 
> My first cassette deck was back in 1980. It was the top of the line Yamaha. It was the most expensive part of my equipment. I did that because I loved to record my own mixed tapes.
> Then I upgraded to a Nakamichi CR-5A. I used Maxell and TDK Chrome. The best one I tried was the TDK that had the frame of aluminum and plastic covers.
> ...


Very Nice, and done on the beer at Cam Jam! I love your equip. I wanted a Nakamichi , in the end I had to settle for an SAE C4.


----------



## paradoxper (Oct 21, 2021)

leftside said:


> A couple of people have asked me about what some of the components are, like what transformers, etc. I thought I might as well post them here:
> 
> Sowter Output custom transformers * 2
> Lundahl LL1650 Transformer
> ...


Do you know if Mischa is limited to these component choices?

The Sowter transformer are ok but far better performance through superior custom options from Trafomatic or Audio Note transformers as well as using far better attenuator choices would allow these amps to shine with the best. I understand sourcing is a long-leading pain but thought I'd ask if the game was open to elevation or only streamline.


----------



## chrisdrop

paradoxper said:


> Do you know if Mischa is limited to these component choices?
> 
> The Sowter transformer are ok but far better performance through superior custom options from Trafomatic or Audio Note transformers as well as using far better attenuator choices would allow these amps to shine with the best. I understand sourcing is a long-leading pain but thought I'd ask if the game was open to elevation or only streamline.


In my experience Mischa is basically open to engage on your preferences. He will, of course , also have informed opinions. I bet you would land wherever you wanted. Basically he is pretty great to work with.


----------



## A2029 (Oct 21, 2021)

paradoxper said:


> Do you know if Mischa is limited to these component choices?
> 
> The Sowter transformer are ok but far better performance through superior custom options from Trafomatic or Audio Note transformers as well as using far better attenuator choices would allow these amps to shine with the best. I understand sourcing is a long-leading pain but thought I'd ask if the game was open to elevation or only streamline.



Nope, not limited; World's your oyster when it comes to my amps. I hold the Sowter and Khozmo attenuators in higher regard though (which is okay to disagree on ).

Sowter is able to produce customized transformers with multiple secondaries, such that amps using those transformers can be impedance matched to the chosen headphones. They also work with your specifications to optimize bandwidth and power requirements. That said, I do agree that there are companies on the market that are able to make custom transformers with amorphous/nanocrystalline/etc. cores with higher performance, but those also generally come with a big jump in their price tag. It's all a matter of performance per dollar for a given spec/customization level, of which I see Sowter as being a very good choice IMO, YMMV.

Khozmo attenuators had a rocky start in the past, and some were known to have quality control issues, but those issues have long been solved (as of the release of their MK2 line of attenuators) and generally Khozmo has great price to performance ratio IMO. The ladder attenuator in Leftside's amp is at the top of the Khozmo range but is no longer produced. It uses gold plated contacts and SMD thin film resistors as most attenuators under a certain price point do (including Goldpoint and Acoustic Dimension), and is also a ladder attenuator instead of the more common series attenuator.


----------



## leftside

Canadian amp with Spanish, Italian and Dutch tubes.


----------



## Xcalibur255

Getting super excited to see mine for the first time!


----------



## leftside (Nov 21, 2021)

Been playing around with brown base tubes this afternoon. I can highly recommend the Fivre 6C5G that Langrex has. They also have the black base, but the brown base are earlier versions with foil getters. The amp totally rocks.


----------



## jonathan c

leftside said:


> Been playing around with brown base tubes this afternoon. I can highly recommend the Fivre 6C5G that Langrex has. They also have the black base, but the brown base are earlier versions with foil getters. The amp totally rocks.


It seems that the ‘foil getter’ variety of a tube is the best of that tube. Q for experts: is this because of the larger surface area that a ‘foil’ getter presents (than a ‘D’, ‘halo’, or ‘square’ getter) to capture gaseous impurities inside the tube?


----------



## leftside

jonathan c said:


> It seems that the ‘foil getter’ variety of a tube is the best of that tube. Q for experts: is this because of the larger surface area that a ‘foil’ getter presents (than a ‘D’, ‘halo’, or ‘square’ getter) to capture gaseous impurities inside the tube?


Personally, I don't think the getter really makes a difference, but I do find "earlier the better" tube is often quite true. And as foil getter tubes tend to be quite early...


----------



## kamui

jonathan c said:


> It seems that the ‘foil getter’ variety of a tube is the best of that tube. Q for experts: is this because of the larger surface area that a ‘foil’ getter presents (than a ‘D’, ‘halo’, or ‘square’ getter) to capture gaseous impurities inside the tube?


The getter has zero impact on how a tube sounds. It is purely an indication of production year, as getter styles changed over production years.


----------



## maxpudding

I think the placement of the getters has some effect on how a tube sounds, rather than the shape of the getters.


----------



## kamui

maxpudding said:


> I think the placement of the getters has some effect on how a tube sounds, rather than the shape of the getters.


It doesn't. It's purely an indication of manufacturing style. Typically, top vs. bottom getters were just a year change, as in older tubes were bottom getter, and they later changed to top getter, likely due to a change in manufacturing process. Getters have zero impact on how a tube sounds.


----------



## maxpudding

kamui said:


> It doesn't. It's purely an indication of manufacturing style. Typically, top vs. bottom getters were just a year change, as in older tubes were bottom getter, and they later changed to top getter, likely due to a change in manufacturing process. Getters have zero impact on how a tube sounds.


Yeah you are right, and I still stand by my opinion, because I forgot to mention that the placement of the getter did include the change of manufacturing process, and by doing so, there are subtle changes to how a tube sounds. And that’s why maybe the bottom getter 6as7 is more preferred than the top getter 6as7. Hence, the tendency to prefer older tubes than the newer ones.


----------



## kamui

maxpudding said:


> Yeah you are right, and I still stand by my opinion, because I forgot to mention that the placement of the getter did include the change of manufacturing process, and by doing so, there are subtle changes to how a tube sounds. And that’s why maybe the bottom getter 6as7 is more preferred than the top getter 6as7. Hence, the tendency to prefer older tubes than the newer ones.


Yeah, exactly. Typically bottom getters are older production, but not always. 5998 tubes seem to have had both at the same time, but I think they are the exception.


----------



## maxpudding

kamui said:


> Yeah, exactly. Typically bottom getters are older production, but not always. 5998 tubes seem to have had both at the same time, but I think they are the exception.



I have a pair of 5998 tubes with the bottom and top getters, they sound great. Unfortunately I cannot make comparisons with the bottom or top getter versions of the 5998 because I don’t have them


----------



## leftside

maxpudding said:


> I have a pair of 5998 tubes with the bottom and top getters, they sound great. Unfortunately I cannot make comparisons with the bottom or top getter versions of the 5998 because I don’t have them


I've got 5998 with top getters and 5998 with bottom getters, but don't have the your version with both top and bottom getters


----------



## maxpudding

leftside said:


> I've got 5998 with top getters and 5998 with bottom getters, but don't have the your version with both top and bottom getters


Sounds like an invitation


----------



## triod750

kamui said:


> It doesn't. It's purely an indication of manufacturing style. Typically, top vs. bottom getters were just a year change, as in older tubes were bottom getter, and they later changed to top getter, likely due to a change in manufacturing process. Getters have zero impact on how a tube sounds.


I don't doubt what you are saying but you speak 'the truth' without qualifying it in any way. You just rely in my logical capacity. If I questioned what you are saying, how would you go about to convince me if you wanted to? I am just interested in an elaborated explanation.


----------



## kamui

triod750 said:


> I don't doubt what you are saying but you speak 'the truth' without qualifying it in any way. You just rely in my logical capacity. If I questioned what you are saying, how would you go about to convince me if you wanted to? I am just interested in an elaborated explanation.


The getter holds the metal for creating a hard vacuum, and serves no other purpose. It can't possibly have any effect on how a tube sounds. If you do some basic googling, you can find multiple sources that support this.


----------



## bcowen

kamui said:


> The getter holds the metal for creating a hard vacuum, and serves no other purpose. It can't possibly have any effect on how a tube sounds. If you do some basic googling, you can find multiple sources that support this.


So long as we're being technical, the getter IS the metal (usually a mixture containing mostly barium).  What we all commonly refer to as 'the getter' is actually the getter _holder_, or what holds the getter material itself in position until it is fired during manufacture.


----------



## jonathan c

maxpudding said:


> I have a pair of 5998 tubes with the bottom and top getters, they sound great. Unfortunately I cannot make comparisons with the bottom or top getter versions of the 5998 because I don’t have them


You need them all to _get_ to the _bottom_ of this…🤨…


----------



## jonathan c

bcowen said:


> So long as we're being technical, the getter IS the metal (usually a mixture containing mostly barium).  What we all commonly refer to as 'the getter' is actually the getter _holder_, or what holds the getter material itself in position until it is fired during manufacture.


Would not a foil getter holder have a larger surface area than other getter holder types, hold more getter material ‘until it is fired during manufacture’? I was musing that this might be _a_ reason for a ‘foil getter’ tube being the best within the tube type/brand.


----------



## kamui

jonathan c said:


> Would not a foil getter holder have a larger surface area than other getter holder types, hold more getter material ‘until it is fired during manufacture’? I was musing that this might be _a_ reason for a ‘foil getter’ tube being the best within the tube type/brand.


The amount of getter material still wouldn't have an impact on how a tube sounds, only on if it were enough material to get a good vacuum on the tube.


----------



## triod750

kamui said:


> The getter holds the metal for creating a hard vacuum, and serves no other purpose. It can't possibly have any effect on how a tube sounds. If you do some basic googling, you can find multiple sources that support this.


Thank you for your response. Since you didn't say 'in my opinion there is no reason to believe that either getter shape or placement has influence on a tube's performance' I expected your statement to be received as a fact and was interested in the background. I have sometimes or often presented my opinion as a fact but am more sensitive when others do the same. I am always willing to learn from other people's knowledge or experience. This is easier if one understands what people are really saying.


----------



## kamui

triod750 said:


> Thank you for your response. Since you didn't say 'in my opinion there is no reason to believe that either getter shape or placement has influence on a tube's performance' I expected your statement to be received as a fact and was interested in the background. I have sometimes or often presented my opinion as a fact but am more sensitive when others do the same. I am always willing to learn from other people's knowledge or experience. This is easier if one understands what people are really saying.


If it wasn't something I was absolutely sure about, I would have said "in my opinion" too, and I do understand that it's a very common misconception. I didn't learn what the getter actually does until I searched for it, as I don't often see it discussed in forums, and hadn't come across the info in any of the tube threads I had read.


----------



## triod750

kamui said:


> If it wasn't something I was absolutely sure about, I would have said "in my opinion" too, and I do understand that it's a very common misconception. I didn't learn what the getter actually does until I searched for it, as I don't often see it discussed in forums, and hadn't come across the info in any of the tube threads I had read.


Do you or don't you need some kind of proof to be sure?


----------



## kamui

What do you mean by proof? My information came from a reputable source, and there are multiple other solid sources that say the same thing.


----------



## triod750 (Nov 24, 2021)

kamui said:


> What do you mean by proof? My information came from a reputable source, and there are multiple other solid sources that say the same thing.


I don't have either the knowledge, experience or inclination to question your conclusions, I was merely interested in what knowledge you had that made you capable of drawing them. By now I know a little more, but just a little. By the way you presented your opinion I was misled (by my expectations) to believe that you had important knowledge that I have missed. Again, thank you for your response. Most welcome.

My opinion is that your conclusions are sensible but I am just guessing.


----------



## triod750

My tube mentor, @gibosi, use to say that older is usually better (probably because I am a few years younger than him) and that getter shape might give you a clue to  time of manufacturing.  'Common knowledge', whatever that is, often surmise that square getter tubes predates halo getter tubes. Inspired by gibosi, I have tried EL42 as input tubes and like them very much. I have mostly used a 1958 pair with small halo getters. Recently I bought a pair of Valvo branded tubes with square getters. (I have several older square getter EL42:s). The getter (holder) didn't look as any other I have seen. The wire was much thinner. Philips factory code was G2F. I consulted with gibosi and there was in theory two alternative interpretations of this code. I will tell the second one and that was the one gibosi suggested; that the '2' meant 1962 and, if so, the 'G' meant Loewe/Opta as manufacturer. I bet that gibosi was convinced of this but he is careful with his facts so he suggested this as his opinion. So in this case the square getter tube is younger than the halo getter one and in my opinion the sound quality is much lesser, used with the same output tubes.

So, if they had been manufactured 1952, as I first suspected, what factory would then have been responsible?


----------



## kamui

triod750 said:


> I don't have either the knowledge, experience or inclination to question your conclusions, I was merely interested in what knowledge you had that made you capable of drawing them. By now I know a little more, but just a little. By the way you presented your opinion I was misled (by my expectations) to believe that you had important knowledge that I have missed. Again, thank you for your response. Most welcome.
> 
> My opinion is that your conclusions are sensible but I am just guessing.


In short, it's understanding what the getter is/does, and like bcowen said, the actual getter is the material that ends up being adhered to the inside of the glass, and what we all call the getter is the remaining holder. Once that concept is understood, it's easy to see that it won't have an impact on sound, due to it's purpose. With some searching, the information isn't difficult to find. If what I and others are saying doesn't make sense to you (or you don't trust what is being said) you can easily find the information for yourself to verify it and understand it better.


----------



## kamui

triod750 said:


> My tube mentor, @gibosi, use to say that older is usually better (probably because I am a few years younger than him) and that getter shape might give you a clue to  time of manufacturing.  'Common knowledge', whatever that is, often surmise that square getter tubes predates halo getter tubes. Inspired by gibosi, I have tried EL42 as input tubes and like them very much. I have mostly used a 1958 pair with small halo getters. Recently I bought a pair of Valvo branded tubes with square getters. (I have several older square getter EL42:s). The getter (holder) didn't look as any other I have seen. The wire was much thinner. Philips factory code was G2F. I consulted with gibosi and there was in theory two alternative interpretations of this code. I will tell the second one and that was the one gibosi suggested; that the '2' meant 1962 and, if so, the 'G' meant Loewe/Opta as manufacturer. I bet that gibosi was convinced of this but he is careful with his facts so he suggested this as his opinion. So in this case the square getter tube is younger than the halo getter one and in my opinion the sound quality is much lesser, used with the same output tubes.
> 
> So, if they had been manufactured 1952, as I first suspected, what factory would then have been responsible?


Getter styles are different depending on who they were manufactured by, and to some degree the tube type as well. That G2F tube would be a Loewe Opta (after 22 Feb 1954) if it were made in 1962, and I don't know enough about them to know when they changed the getter style. From my experience it's usually around 1960, but I've seen it into the early 60's depending on tube type. You would need to compare to other examples of that tube to try to figure out if it's 1962, or a Mullard from 1952. Typically older is better, but different plants made different sounding tubes, so just because it's old, doesn't mean it's as good as everything else that age.


----------



## triod750

kamui said:


> In short, it's understanding what the getter is/does, and like bcowen said, the actual getter is the material that ends up being adhered to the inside of the glass, and what we all call the getter is the remaining holder. Once that concept is understood, it's easy to see that it won't have an impact on sound, due to it's purpose. With some searching, the information isn't difficult to find. If what I and others are saying doesn't make sense to you (or you don't trust what is being said) you can easily find the information for yourself to verify it and understand it better.


You might have missed this last sentence: "My opinion is that your conclusions are sensible but I am just guessing". I am not discussing technical matters, just the difference between facts and opinions/ suggestions.

My suggestion is that we leave this now.


----------



## triod750

kamui said:


> Getter styles are different depending on who they were manufactured by, and to some degree the tube type as well. That G2F tube would be a Loewe Opta (after 22 Feb 1954) if it were made in 1962, and I don't know enough about them to know when they changed the getter style. From my experience it's usually around 1960, but I've seen it into the early 60's depending on tube type. You would need to compare to other examples of that tube to try to figure out if it's 1962, or a Mullard from 1952. Typically older is better, but different plants made different sounding tubes, so just because it's old, doesn't mean it's as good as everything else that age.


This correlates with what little I know. I have compared it to several other EL42 from different manufacturers and years and getter styles and it was easy for me to accept gibosi's suggestion. Mullard's 'G' facility might not have made any EL42. Those I have, branded Adzam, Philips and Mullard are made in Blackburn.


----------



## A2029

Happy Thanksgiving to all those celebrating today!! 🎉🦃


----------



## triod750 (Nov 25, 2021)

triod750 said:


> This correlates with what little I know. I have compared it to several other EL42 from different manufacturers and years and getter styles and it was easy for me to accept gibosi's suggestion. Mullard's 'G' facility might not have made any EL42. Those I have, branded Adzam, Philips and Mullard are made in Blackburn.


And 'G' was Mullard, Fleetwood up to 22 Feb 1954, then Loewe/Opta for some reason...

Happy old year!


----------



## leftside (Dec 1, 2021)

Decided to try out a few of the old classic tubes tonight. Fivre 6C5G, Mullard ECC33, Brimar CV1988, Sylvania 6SN7 WGTA, Mullard 6J5G, MWT L63, Fivre 6SN7. The thing they all have in common apart from sounding superb? Brown bases.

Things that stood out. Fivre 6C5G:lively and dynamic. Mullard ECC33: the bass! Brimar CV1988: warmest. Sylvania: closer to the Fivre. Mullard 6J5G: detail and textures. MWT L63: does everything right with a hint of warmth and strong bass.

Favorites: Mullard ECC33 and MWT L63. The bass with this amp, tubes and electronic music is stellar.


----------



## A2029

Merry Christmas and Happy New Year everyone!!!   🎁🎉🎇


----------



## leftside

A2029 said:


> Merry Christmas and Happy New Year everyone!!!   🎁🎉🎇


Same. Wife has just gone to bed. Time for some Xmas listening with the V6.


----------



## jonathan c

leftside said:


> Same. Wife has just gone to bed. Time for some Xmas listening with the V6.


Xmas listening?…get a head start on headphoning in the new year…in your time zone, you could use the head start 😆…


----------



## Xcalibur255

The latest 1101 Audio creation has landed.  Took me a few days to get around to posting this due to an awkward living situation I'm currently dealing with.  The same situation also limits my ability to do any serious listening on the amp, especially on speakers which is what this amp was primarily meant for.





Here it is powered on and with a different set of output tubes in place (Gold Lion KT66 new production).





And this is the Sophia EL34ST "blue glass" new production tube.

From the few brief chances I have had to listen on the headphone out I have been very impressed so far.  I think my favorite out of the three output tubes I chose to start out with is the Sophia.  Was quite worried they would be a waste of money but there is a certain wow factor to their tone that really grabbed me right away.  The Tung Sol KT150 is the most resolving of the three, and reaches deepest into the music, but it's tone is a bit more whitewashed compared to the Sophia.  The KT66 is probably the least resolving of the three but has a fun cheerful tonal presentation that's easy to enjoy.

I might form whatever listening impressions I can in the format of comparison to my Glenn 45 amp.  It feels easier to contrast the impressions that way.  What I can say for now is that I'm very happy with what I'm hearing from the headphone jack of this amp.  I honestly didn't think the Ethers were *capable* of sounding this balanced and open.  How the amp sounds with my Omega full range speakers will sadly have to be left to imagination for the foreseeable future until some other circumstances sort themselves out.  Since the amp has landed though I wanted to get something posted to share with the community even though the circumstances are not idea for now.


----------



## cdanguyen08

Xcalibur255 said:


> The latest 1101 Audio creation has landed.  Took me a few days to get around to posting this due to an awkward living situation I'm currently dealing with.  The same situation also limits my ability to do any serious listening on the amp, especially on speakers which is what this amp was primarily meant for.
> 
> 
> 
> ...



Stoked for you @Xcalibur255 !! I took inspiration from your build. I hope your living situation becomes better so that you may enjoy your new amp with your speakers. I'm currently waiting to move in a few months that will allow me more space for my setup.  Baby took over my listening room!


----------



## whirlwind

Xcalibur255 said:


> The latest 1101 Audio creation has landed.  Took me a few days to get around to posting this due to an awkward living situation I'm currently dealing with.  The same situation also limits my ability to do any serious listening on the amp, especially on speakers which is what this amp was primarily meant for.
> 
> 
> 
> ...



Nice! Looks great!

Hope you can get settled in and enjoy.


----------



## ThanatosVI

Xcalibur255 said:


> The latest 1101 Audio creation has landed.  Took me a few days to get around to posting this due to an awkward living situation I'm currently dealing with.  The same situation also limits my ability to do any serious listening on the amp, especially on speakers which is what this amp was primarily meant for.
> 
> 
> 
> ...


Nice amp, van you give us some more Details about used parts etc?


----------



## Xcalibur255

ThanatosVI said:


> Nice amp, van you give us some more Details about used parts etc?


Did you have anything specific in mind?  It's using the same chassis Mischa uses for his Blue Halo amps, only the front panel design and layout is custom/unique to this build.  This is a dual function speaker/headphone design with a targeted output of 12 watts on the speaker taps in KT150 mode.  The tubes are operated as triodes.  Drivers are 6J5, I opted to not do any other driver sockets for 6SN7 or voltage switch for 12/25 volt versions in the name of simplicity.  I find 6J5 tubes to sound excellent and have a good selection collected and thus decided to keep it simple.  On the output side it's designed primarily as a KT150 amplifier, but it also has the ability to run EL34 and other tubes with similar dissipation ratings such as KT66 and 6L6GC.  Some of this was bet hedging in case I didn't care for the tonal presentation of the KT150, I wanted something to fall back on.  Also the EL34 is pretty famous for its tone and I just wanted the option for a different flavor.  

The amp features a dual B+ implementation for the EL34 and KT150.  Both voltage and current are different creating unique operating points for each tube.  The KT150 specific bias mode would nuke an EL34 tube, it is setup for higher voltage specifically to get the KT150 to a more optimum operating point.  

Off the top of my head the big ticket items for components are:

Output transformers - Monolith Summit S14
Primary interstage cap - Miflex KPCU-01
Driver stage is CCS load, output stage is a custom circuit by Mischa.
Many of the other smaller component details I left to Mischa and I believe are mostly the same as his premium upgrade selections he offers on his other amps.

I have tried the KT150 using the EL34 bias mode and I can say that how "hot" or "cold" you run the operating points on these tubes really makes a difference.  There is a substantial difference in sound between the two bias points, with the higher bias being the better one.  Even the high bias mode is not operating the tube anywhere near it's max ratings (in fact it's more gentle than the EL34 mode is for an EL34 tube) so I will still get good tube life.


----------



## Xcalibur255

Of course I also have to mention that Mischa has been an absolute pleasure to work with from beginning to end.  He is extremely generous with his time and energy explaining how things work and making sure you are satisfied with the choices you are making.  This has been said by others too but it is well worth repeating again.


----------



## ThanatosVI

Xcalibur255 said:


> Did you have anything specific in mind?  It's using the same chassis Mischa uses for his Blue Halo amps, only the front panel design and layout is custom/unique to this build.  This is a dual function speaker/headphone design with a targeted output of 12 watts on the speaker taps in KT150 mode.  The tubes are operated as triodes.  Drivers are 6J5, I opted to not do any other driver sockets for 6SN7 or voltage switch for 12/25 volt versions in the name of simplicity.  I find 6J5 tubes to sound excellent and have a good selection collected and thus decided to keep it simple.  On the output side it's designed primarily as a KT150 amplifier, but it also has the ability to run EL34 and other tubes with similar dissipation ratings such as KT66 and 6L6GC.  Some of this was bet hedging in case I didn't care for the tonal presentation of the KT150, I wanted something to fall back on.  Also the EL34 is pretty famous for its tone and I just wanted the option for a different flavor.
> 
> The amp features a dual B+ implementation for the EL34 and KT150.  Both voltage and current are different creating unique operating points for each tube.  The KT150 specific bias mode would nuke an EL34 tube, it is setup for higher voltage specifically to get the KT150 to a more optimum operating point.
> 
> ...


That's pretty much everything I wanted to know


----------



## Xcalibur255

cdanguyen08 said:


> Stoked for you @Xcalibur255 !! I took inspiration from your build. I hope your living situation becomes better so that you may enjoy your new amp with your speakers. I'm currently waiting to move in a few months that will allow me more space for my setup.  Baby took over my listening room!


Thank you!  I'm very happy with how it turned out.  I added the headphone output more or less because we could and it cost very little to include it, this really was meant to be a speaker amplifier.  That said so far I've only been able to use it as a headphone amp and it sounds really good as one!  It took me about 15 seconds to conclude that it's outperforming my Glenn 45 (I say that with mixed feelings to be honest because I love that amp) and I intend to compose some thoughts and go into more detail on that at some point in the future.


----------



## whirlwind

Xcalibur255 said:


> Did you have anything specific in mind?  It's using the same chassis Mischa uses for his Blue Halo amps, only the front panel design and layout is custom/unique to this build.  This is a dual function speaker/headphone design with a targeted output of 12 watts on the speaker taps in KT150 mode.  The tubes are operated as triodes.  Drivers are 6J5, I opted to not do any other driver sockets for 6SN7 or voltage switch for 12/25 volt versions in the name of simplicity.  I find 6J5 tubes to sound excellent and have a good selection collected and thus decided to keep it simple.  On the output side it's designed primarily as a KT150 amplifier, but it also has the ability to run EL34 and other tubes with similar dissipation ratings such as KT66 and 6L6GC.  Some of this was bet hedging in case I didn't care for the tonal presentation of the KT150, I wanted something to fall back on.  Also the EL34 is pretty famous for its tone and I just wanted the option for a different flavor.
> 
> The amp features a dual B+ implementation for the EL34 and KT150.  Both voltage and current are different creating unique operating points for each tube.  The KT150 specific bias mode would nuke an EL34 tube, it is setup for higher voltage specifically to get the KT150 to a more optimum operating point.
> 
> ...



Yeah, you should get a nice long tube life.

I would like to hear the EL34 & Mullard EL37 at their max bias.....just to say I did     

Enjoy!


----------



## chrisdrop

Xcalibur255 said:


> The latest 1101 Audio creation has landed.  Took me a few days to get around to posting this due to an awkward living situation I'm currently dealing with.  The same situation also limits my ability to do any serious listening on the amp, especially on speakers which is what this amp was primarily meant for.
> 
> 
> 
> ...


Congrats on this beauty.


----------



## Xcalibur255 (Mar 8, 2022)

So I think I have managed to sneak in just enough time here and there to get some idea of the character of this amp.  Most of it has been characterized by burn-in progression, more so from the output tubes (all of which were new production with no hours on them) than the amp itself I am thinking.  Also a warm-up behavior that is somewhat different than what I'm used to from other tubes amps and can't tell if it's the amp circuit or the KT150s at the source of it (I suspect the latter).

What has been steadily growing in me, though, is a profound appreciation for what this amp does NOT do.  I'm one of those people who is kind of both a left brain and right brain music listener at the same time.  The primary experience is very much an emotional one, but as soon as any little thing turns on the analytical side of my mind the experience suddenly becomes entirely about focusing on that.  My mind has a strong natural tendency to seek faults in things, so any negative qualities in the sound automatically become the focus of the listening.  Shout, edge, glare, sibilance, honk, and the dozen other words we use to describe negative qualities in music reproduction, as soon as I hear one of them it is the ONLY thing I hear.  This has been the great curse of my relationship with this hobby.

Thus, for me the ideal amplifier is one that is completely devoid of these negative qualities.  That's my holy grail.  I used to think I was fussy about tone and other qualitative aspects of the sound, but what I am discovering more recently is that I'm actually not as long as these distracting negative components are not present.  I think Mischa's amp is the first and only amplifier I have heard in my life that seems like it actually fulfills this need.  I have yet to ever hear it sound harsh or edgy, exhibit glare or shout, or highlight sibilance or other negative aspects of a recording.  It is extraordinarily well-behaved even when working with fresh tubes or before warm-up.  It does sound different under these conditions, but the gremlins are still kept at bay.

The other thing I have found interesting about all of this is the other side of the coin:  questions about how transparent it sounds, how layered, how expansive, how expressive, how REAL........ all of those thoughts just sort of melt away.  Because all of this just seems to naturally fall into place when the ugly stuff is banished.  Here, though, there is definitely a difference between warmed up and not, and between fresh tubes and ones that have some hours on them.  The key difference is depth.  When I finally got a few hours on some of the output tubes the sense of depth and layering was beyond anything I've experienced before.  All of the other technical aspects, timbre accuracy, tone saturation, dynamic expression, these are all excellent and well sorted too, but this sense of being able to listen deeply into the mix is what continues to draw my fascination.

The exciting thing is I still don't think I have heard 100% of what this amplifier has to offer, but I feel like I've gotten a couple of really good glimpses now and it's been exciting.  Enough so that I felt the time was right to share for a bit.  Even more staggering is that this was supposed to be a speaker amp and all of these listening impressions have been from headphone listening, so I'm being impressed by the amplifier's secondary functionality.  Hats off to Mischa for his talent and effort.  I can't wait to see where it goes from here.


----------



## Monsterzero

Xcalibur255 said:


> So I think I have managed to sneak in just enough time here and there to get some idea of the character of this amp.  Most of it has been characterized by burn-in progression, more so from the output tubes (all of which were new production with no hours on them) than the amp itself I am thinking.  Also a warm-up behavior that is somewhat different than what I'm used to from other tubes amps and can't tell if it's the amp circuit or the KT150s at the source of it (I suspect the latter).
> 
> What has been steadily growing in me, though, is a profound appreciation for what this amp does NOT do.  I'm one of those people who is kind of both a left brain and right brain music listener at the same time.  The primary experience is very much an emotional one, but as soon as any little thing turns on the analytical side of my mind the experience suddenly because entirely about focusing on that.  My mind has a strong natural tendency to seek faults in things, so any negative qualities in the sound automatically become the focus of the listening.  Shout, edge, glare, sibilance, honk, and the dozen other words we use to describe negative qualities in music reproduction, as soon as I hear one of them it is the ONLY thing I hear.  This has been the great curse of my relationship with this hobby.
> 
> ...


Very well written. I'm looking forward to more of your thoughts on the amp down the line


----------



## cdanguyen08

Xcalibur255 said:


> So I think I have managed to sneak in just enough time here and there to get some idea of the character of this amp.  Most of it has been characterized by burn-in progression, more so from the output tubes (all of which were new production with no hours on them) than the amp itself I am thinking.  Also a warm-up behavior that is somewhat different than what I'm used to from other tubes amps and can't tell if it's the amp circuit or the KT150s at the source of it (I suspect the latter).
> 
> What has been steadily growing in me, though, is a profound appreciation for what this amp does NOT do.  I'm one of those people who is kind of both a left brain and right brain music listener at the same time.  The primary experience is very much an emotional one, but as soon as any little thing turns on the analytical side of my mind the experience suddenly because entirely about focusing on that.  My mind has a strong natural tendency to seek faults in things, so any negative qualities in the sound automatically become the focus of the listening.  Shout, edge, glare, sibilance, honk, and the dozen other words we use to describe negative qualities in music reproduction, as soon as I hear one of them it is the ONLY thing I hear.  This has been the great curse of my relationship with this hobby.
> 
> ...


I'm glad you were able to find some time to listen. Thank you for the impressions! I can only imagine how long Mischa waitlist is now.


----------



## leftside

Xcalibur255 said:


> So I think I have managed to sneak in just enough time here and there to get some idea of the character of this amp.  Most of it has been characterized by burn-in progression, more so from the output tubes (all of which were new production with no hours on them) than the amp itself I am thinking.  Also a warm-up behavior that is somewhat different than what I'm used to from other tubes amps and can't tell if it's the amp circuit or the KT150s at the source of it (I suspect the latter).
> 
> What has been steadily growing in me, though, is a profound appreciation for what this amp does NOT do.  I'm one of those people who is kind of both a left brain and right brain music listener at the same time.  The primary experience is very much an emotional one, but as soon as any little thing turns on the analytical side of my mind the experience suddenly becomes entirely about focusing on that.  My mind has a strong natural tendency to seek faults in things, so any negative qualities in the sound automatically become the focus of the listening.  Shout, edge, glare, sibilance, honk, and the dozen other words we use to describe negative qualities in music reproduction, as soon as I hear one of them it is the ONLY thing I hear.  This has been the great curse of my relationship with this hobby.
> 
> ...


Great review. I too tend to focus on anything "negative" about what I am listening to and once it's been identified my brain will also fixate on it. On the flip side, once you find a well produced recording with music you like with good tubes/gear then it is a very pleasant experience and the emotional side can take over.


----------



## mordy

leftside said:


> Great review. I too tend to focus on anything "negative" about what I am listening to and once it's been identified my brain will also fixate on it. On the flip side, once you find a well produced recording with music you like with good tubes/gear then it is a very pleasant experience and the emotional side can take over.


I cannot describe things as well as Xcalibur or leftside but in determining if I like a certain sound I sort of get a feeling that “nothing bothers me.”
But the setup I really like does not sound the same every time I turn on my equipment. There are times when it seems to be more engaging and sound better. Often the sound appeals more to me late at night - don’t know if it has something to do with that the electric grid has less interference
 then, or maybe it’s just me…haven’t been able to figure it out yet….
Sometimes the listening experience is wonderful, and at other times just ok, even listening to the same recording.


----------



## Xcalibur255 (Mar 9, 2022)

mordy said:


> I cannot describe things as well as Xcalibur or leftside but in determining if I like a certain sound I sort of get a feeling that “nothing bothers me.”
> But the setup I really like does not sound the same every time I turn on my equipment. There are times when it seems to be more engaging and sound better. Often the sound appeals more to me late at night - don’t know if it has something to do with that the electric grid has less interference
> then, or maybe it’s just me…haven’t been able to figure it out yet….
> Sometimes the listening experience is wonderful, and at other times just ok, even listening to the same recording.


I've spent a fair amount of time pondering this phenomenon (that your system sounds different to you on different days).  If we assume that the gear itself isn't exhibiting variability and use it as a control reference, it's helpful to look at some of the external things that can influence this.  Some things that I'm fairly confident play a factor are barometric pressure and the static resting pressure in your ears, and also your blood pressure levels.  For myself, for example, music sounds much worse if I have had any alcohol which has a number of effects on your cardiovascular system.  For headphones in particular I've also come to realize over time that most of them vary in performance a surprisingly large amount due to small changes in how they are sitting on your head from session to session.  We also cannot discount the mood we are in.  The brain does a LOT of messing around with the raw information that comes from our senses, all in the background in your minds subconscious processes.  It's entirely possible to hear the same music differently on two different days because your mental processes caused you to focus on it in different ways during each of those sessions.

On the gear side I suspect for tube amps in particular small changes in voltage from your wall may also be audible, such as differences between peak and non-peak consumption times for the grid.  I've also grown confident over the years that something 'settles' when it comes to physical connections such as RCA line jacks, the headphone cable jack, and the interface between tube socket and tube pin.  When you unplug one of these things after they have gone untouched for a long time I can definitely pick up a shift in the sound from it.

Those are a few things that come to mind off the top of my head.


----------



## bcowen (Mar 9, 2022)

Xcalibur255 said:


> I've spent a fair amount of time pondering this phenomenon (that your system sounds different to you on different days).  If we assume that the gear itself isn't exhibiting variability and use it as a control reference, it's helpful to look at some of the external things that can influence this.  Some things that I'm fairly confident play a factor are barometric pressure and the static resting pressure in your ears, and also your blood pressure levels.  For myself, for example, music sounds much worse if I have had any alcohol which has a number of effects on your cardiovascular system.  For headphones in particular I've also come to realize over time that most of them vary in performance a surprisingly large amount due to small changes in how they are sitting on your head from session to session.  We also cannot discount the mood we are in.  The brain does a LOT of messing around with the raw information that comes from our senses, all in the background in your minds subconscious processes.  It's entirely possible to hear the same music differently on two different days because your mental processes caused you to focus on it in different ways during each of those sessions.
> 
> On the gear side I suspect for tube amps in particular small changes in voltage from your wall may also be audible, such as differences between peak and non-peak consumption times for the grid.  I've also grown confident over the years that something 'settles' when it comes to physical connections such as RCA line jacks, the headphone cable jack, and the interface between tube socket and tube pin.  When you unplug one of these things after they have gone untouched for a long time I can definitely pick up a shift in the sound from it.
> 
> Those are a few things that come to mind off the top of my head.


I think all of those things can be a factor.  I chalk a lot of it up as well to "emotional reception," if you will.  There are times I sit down prepared to enjoy some music for a bit and I just don't connect with it.  Beyond the external variables that you note, nothing has physically changed, and I was jammin' and rocking out with it the day before.  Then I can sit down the next day and I'm fully engaged again.  Brain clutter, maybe. Just this afternoon I was in the middle of some other stuff but turned on the amp to let it warm up for later.  Popped on the headphones (not even optimally situated on my head) just for a quick sound check.  CSN&Y "Country Girl" was on Tidal, and even with tubes that weren't up to full operating temperature and a recording that can best be described as really bad, I was transported back to high school -- 6 guys sardined into an AMC Javelin, holding our beer cans as microphones and singing every word by heart at the top of our lungs, pot smoke curling out of the cracked windows.  I mean the memory was so vivid...only music can do that for me.  That emotional connection, I guess.  Two hours later I got back to what I was doing.  LOL!


----------



## Zachik

bcowen said:


> I was transported back to high school


The horrors...


----------



## LoryWiv

bcowen said:


> I was transported back to high school


As long as there was no accompanying acne or teen angst. Our minds romanticize our youth, which is a good thing! There is a book I (almost) made it through called "This is Your Brain on Music" by Daniel Leviton. Amongst other fascinating topics is how / why the music we hear and love when we are young, coming of age is so uniquely imprinted in our brains and has a special resonance throughout our lives.


----------



## bcowen

LoryWiv said:


> As long as there was no accompanying acne or teen angst. Our minds romanticize our youth, which is a good thing! There is a book I (almost) made it through called "This is Your Brain on Music" by Daniel Leviton. Amongst other fascinating topics is how / why the music we hear and love when we are young, coming of age is so uniquely imprinted in our brains and has a special resonance throughout our lives.


The only angst I had at that point revolved around sitting in a car with 5 guys instead of 5 girls.  😂😂


----------



## jonathan c

bcowen said:


> The only angst I had at that point revolved around sitting in a car with 5 guys instead of 5 girls.  😂😂


…and who got that sixth can of beer…😳


----------



## bcowen

jonathan c said:


> …and who got that sixth can of beer…😳


Well, I was the 6th, so I always got it. But IIRC, we all brought a 6-pack, so 6 each.


----------



## jonathan c

LoryWiv said:


> As long as there was no accompanying acne or teen angst. Our minds romanticize our youth, which is a good thing! There is a book I (almost) made it through called "This is Your Brain on Music" by Daniel Leviton. Amongst other fascinating topics is how / why the music we hear and love when we are young, coming of age is so uniquely imprinted in our brains and has a special resonance throughout our lives.


…Cannot explain the ‘bromance’ of bcowen & Marilyn Manson…🤔🤪…


----------



## Xcalibur255

bcowen said:


> 6 guys sardined into an AMC Javelin


Thank goodness it was a Javelin and not a Pacer or Gremlin.


----------



## jonathan c

bcowen said:


> I think all of those things can be a factor.  I chalk a lot of it up as well to "emotional reception," if you will.  There are times I sit down prepared to enjoy some music for a bit and I just don't connect with it.  Beyond the external variables that you note, nothing has physically changed, and I was jammin' and rocking out with it the day before.  Then I can sit down the next day and I'm fully engaged again.  Brain clutter, maybe. Just this afternoon I was in the middle of some other stuff but turned on the amp to let it warm up for later.  Popped on the headphones (not even optimally situated on my head) just for a quick sound check.  CSN&Y "Country Girl" was on Tidal, and even with tubes that weren't up to full operating temperature and a recording that can best be described as really bad, I was transported back to high school -- 6 guys sardined into an AMC Javelin, holding our beer cans as microphones and singing every word by heart at the top of our lungs, pot smoke curling out of the cracked windows.  I mean the memory was so vivid...only music can do that for me.  That emotional connection, I guess.  Two hours later I got back to what I was doing.  LOL!


…the real magic is that you still have memory…!…🤣🤪…


----------



## jonathan c

bcowen said:


> I was transported *back *to high school -- 6 guys sardined into an *AMC Javelin* …


Back?…….The ‘phone booth wasn’t good enough?……


----------



## Monsterzero

Man, i would kill for a fully restored Javelin! I love early 70s muscle cars almost as much as I love headphones and dogs!


----------



## musicman59

A friend of mine has a fully original in perfect shape Yellow Javelin with Black interiors stored. Once in a while he takes it out for a ride. He is the original owner.


----------



## bcowen

musicman59 said:


> A friend of mine has a fully original in perfect shape Yellow Javelin with Black interiors stored. Once in a while he takes it out for a ride. He is the original owner.


My friend's Javelin was a 6 cylinder, and while responsive and fairly sporty in those days it wasn't a muscle car at all. He found a '71 AMX (2-seat version) with the 401 cubic inch engine our senior year. Now THAT was a muscle car.  IIRC it was over 300 HP which was _mega _horsepower in those days, and especially potent in a tiny 2-seater.  I think it lasted about 3 months and 3 sets of rear tires before he blew the engine.


----------



## Xcalibur255

For those who might be interested I posted an initial impression of the KR KT150 tubes I bought for my 1101 Amp in the KT tubes thread:

https://www.head-fi.org/threads/the...t63-kt61-6v6-etc.959519/page-20#post-16881971


----------



## maxpudding

Hey guys, Mischa was very kind to share some photos of the BH+ with me a couple of days ago, and now he has permitted me to share this sneak peek photo of the first ever BH+ with you.


----------



## UntilThen

Congrats maxpudding. Nothing beats the thrill of a new amp arriving and this one looks good !


----------



## Xcalibur255

maxpudding said:


> Hey guys, Mischa was very kind to share some photos of the BH+ with me a couple of days ago, and now he has permitted me to share this sneak peek photo of the first ever BH+ with you.


That looks more like Blue Halo++ to me.  

So we've got 6SN7 and 6J5 options in the front three sockets, and I'm guessing the next two are for 6080/6AS7, but what are the other four sockets for?  Plenty of tube rolling opportunities here for sure!

It's nice to see some activity around here too.


----------



## mordy

Xcalibur255 said:


> That looks more like Blue Halo++ to me.
> 
> So we've got 6SN7 and 6J5 options in the front three sockets, and I'm guessing the next two are for 6080/6AS7, but what are the other four sockets for?  Plenty of tube rolling opportunities here for sure!
> 
> It's nice to see some activity around here too.


I think that there are 6 power tube sockets.


----------



## maxpudding

Xcalibur255 said:


> That looks more like Blue Halo++ to me.
> 
> So we've got 6SN7 and 6J5 options in the front three sockets, and I'm guessing the next two are for 6080/6AS7, but what are the other four sockets for?  Plenty of tube rolling opportunities here for sure!
> 
> It's nice to see some activity around here too.



Almost correct  6 sockets for power tubes. It can run 2 or 4 6080/6AS7/5998 tubes or six 6BL7/6BX7. Also, there's an optional upgrade to use the 6336/6528 family tubes. Yeah, plenty of rolling opportunities. This amp also has a 12V switch.

The nice thing about this amp is that there's an "off" switch for the power tubes, basically turning it into a BH amp, with only the driver tubes dictating the sound characteristics.


----------



## L0rdGwyn

maxpudding said:


> Also, there's an optional upgrade to use the 6336/6528 family tubes.



YESSSS.  Be ready to crank that AC


----------



## A2029 (Aug 17, 2022)

Hi Guys! It's been a while! I took somewhat of a Head-Fi hiatus to focus on finishing off my PhD this past while, so I haven't been around much, and amp building has been pretty turtle pace. Thank you to everyone who has been waiting on an amp for your huge patience!!!



maxpudding said:


> It can run 2 or 4 6080/6AS7/5998 tubes or six 6BL7/6BX7



Technically it can even run 6 of the 6080/6AS7/5998 family of tubes 😲, but the chassis would become a volcano/inferno of heat, and parts lifespan would start to degrade, so only 2-4 6080/6AS7G/5998 are recommended for running long term.


----------



## Xcalibur255

maxpudding said:


> Almost correct  6 sockets for power tubes. It can run 2 or 4 6080/6AS7/5998 tubes or six 6BL7/6BX7. Also, there's an optional upgrade to use the 6336/6528 family tubes. Yeah, plenty of rolling opportunities. This amp also has a 12V switch.
> 
> The nice thing about this amp is that there's an "off" switch for the power tubes, basically turning it into a BH amp, with only the driver tubes dictating the sound characteristics.


6 x 6BX7 makes perfect sense.  I'm guessing the main power transformer is under one of those covers?  That will help with the heat somewhat.  The mains transformer had to go inside the chassis in my amp because of the BAoTs (big ass output transformers), so my chassis also gets pretty hot because of that heat source despite only running 4 tubes total.


----------



## kamui

L0rdGwyn said:


> YESSSS.  Be ready to crank that AC


I suspect I'm the source of that upgrade option. I've been wanting an amp that can run them for a while, so bugged Mischa about it and it was an easy mod to be able to run a pair.


----------



## mordy

kamui said:


> I suspect I'm the source of that upgrade option. I've been wanting an amp that can run them for a while, so bugged Mischa about it and it was an easy mod to be able to run a pair.


Do you mean one pair of 6336 tubes? I have tried it in the GOTL and while it gets hot it is not unbearable. But watch out not to touch those 5A tubes by mistake - ouch!!!
One 6336/6528 is equivalent to a double 6AS7G.
Re running multiple power tubes, I have found that 6 x 0.9A tubes can give excellent results.


----------



## A2029

Xcalibur255 said:


> I'm guessing the main power transformer is under one of those covers?



Under one of the covers is a Lundahl transformer, and under the other cover is two big beefy toroidal transformers, for a total of ~570 VA of transformer potential. Up to 21 amps of 6.3V current just for the tube heaters 



mordy said:


> Do you mean one pair of 6336 tubes?



Just one pair of 6336 (one per side) as they demand such high current each.


----------



## mordy

I am using this external power supply (from a PC) to supply current to the power tubes in one of my amps. The electricity goes from one of the 12V connectors to a 15A voltage regulator set at 6.3V.
Based on the specs of this PS, can someone tell me how many amps I am getting to the tubes?




Some people claim that such an inexpensive power supply would be noisy in a Hi-Fi application, bit I have not noted any problems with it.


----------



## A2029

mordy said:


> I am using this external power supply (from a PC) to supply current to the power tubes in one of my amps. The electricity goes from one of the 12V connectors to a 15A voltage regulator set at 6.3V.
> Based on the specs of this PS, can someone tell me how many amps I am getting to the tubes?
> 
> Some people claim that such an inexpensive power supply would be noisy in a Hi-Fi application, bit I have not noted any problems with it.



The number of amps would depend on what tubes are being powered. Approximately 2.5amps for each 6080/6AS7, 0.3 amps for each 6J5, etc., Just have to add them up to get your total draw.

IDHT tubes have the good fortune of having the heater mostly out of the audio circuit (except for capacitive coupling and a bit of diode-like leakage between heater and cathode), so switch mode supplies can be used for the heater supply, especially if there is a bit more filtering or a linear regulator on their output. DHT tubes aren't so lucky, and on those you would notice the SMPS noise a lot more.


----------



## mordy

A2029 said:


> The number of amps would depend on what tubes are being powered. Approximately 2.5amps for each 6080/6AS7, 0.3 amps for each 6J5, etc., Just have to add them up to get your total draw.
> 
> IDHT tubes have the good fortune of having the heater mostly out of the audio circuit (except for capacitive coupling and a bit of diode-like leakage between heater and cathode), so switch mode supplies can be used for the heater supply, especially if there is a bit more filtering or a linear regulator on their output. DHT tubes aren't so lucky, and on those you would notice the SMPS noise a lot more.


Thanks for the answer. I am using this PS for 5.4A now, and I know that it can handle one pair of 6336 tubes at 10A.
However, what I don’t understand from the ratings of the PS is if it can handle  four 6336 tubes at 20 amps.
Don’t have an electronic background, but I know that the start-up current (in -rush current) is higher than the current draw when everything is powered up. This in-rush current could be maybe 30% (?) more than the regular current draw and may overload the PS and voltage regulator.
If I know the maximum current this setup can handle it would be helpful to me.
Sorry if I did not express myself clearly but this is from my non- technical perspective.


----------



## A2029

mordy said:


> Thanks for the answer. I am using this PS for 5.4A now, and I know that it can handle one pair of 6336 tubes at 10A.
> However, what I don’t understand from the ratings of the PS is if it can handle  four 6336 tubes at 20 amps.
> Don’t have an electronic background, but I know that the start-up current (in -rush current) is higher than the current draw when everything is powered up. This in-rush current could be maybe 30% (?) more than the regular current draw and may overload the PS and voltage regulator.
> If I know the maximum current this setup can handle it would be helpful to me.
> Sorry if I did not express myself clearly but this is from my non- technical perspective.



Thermaltake TR2-430 has a rated wattage of 430W, so you could run all four 6336 tubes when they are heated as long as you run two of the 6336 off of 12V rail 1 and two of the 6336 off of 12V rail 2. But you're right about the inrush on power up; some switchmode power supplies will fully shut off when they go into overload, and only turn back on when power is manually cycled off then on again. Other supplies will keep trying to push their max current, and just turn on/off a whole bunch over and over (producing a huge amount of high frequency noise) until the current draw drops below their max rating. If the TR2-430 is of the 2nd type, then it could potentially start with the high inrush, and the inrush will decrease as the tube filaments reach their operating temperature. Modern computer power supplies like that are protected against faults like current overloads, so I don't see any harm in trying to see if you can get it to start with the 4x 6336.


P.s. 4x 6336 - Able to turn your furnace off during the winter  lol!


----------



## Zachik

A2029 said:


> P.s. 4x 6336 - Able to turn your furnace off during the winter  lol!


4 x 6336 could accelerate global warming!


----------



## mordy

A2029 said:


> Thermaltake TR2-430 has a rated wattage of 430W, so you could run all four 6336 tubes when they are heated as long as you run two of the 6336 off of 12V rail 1 and two of the 6336 off of 12V rail 2. But you're right about the inrush on power up; some switchmode power supplies will fully shut off when they go into overload, and only turn back on when power is manually cycled off then on again. Other supplies will keep trying to push their max current, and just turn on/off a whole bunch over and over (producing a huge amount of high frequency noise) until the current draw drops below their max rating. If the TR2-430 is of the 2nd type, then it could potentially start with the high inrush, and the inrush will decrease as the tube filaments reach their operating temperature. Modern computer power supplies like that are protected against faults like current overloads, so I don't see any harm in trying to see if you can get it to start with the 4x 6336.
> 
> 
> P.s. 4x 6336 - Able to turn your furnace off during the winter  lol!


Thanks for the extensive answer. As of now I am only using one of the 12V rails. It seems to me that if I want to use 4 x 6336 I would need a second voltage regulator for a dual setup, using both 12V rails.


----------



## whirlwind

Zachik said:


> 4 x 6336 could accelerate global warming!



Ha...no truer words have ever been spoken


----------



## raindownthunda

A2029 said:


> just one pair of 6336 (one per side) as they demand such high current each.


Does anyone know if there is a difference between 6336A and 6336B tubes? The graphite plate versions look identical to me. Safe to assume they were all made by the same manufacturer?


----------



## L0rdGwyn (Aug 20, 2022)

raindownthunda said:


> Does anyone know if there is a difference between 6336A and 6336B tubes? The graphite plate versions look identical to me. Safe to assume they were all made by the same manufacturer?



6336B is a more ruggedized version of the 6336A, meant to handle prolonged exposure to vibration, appears that it uses ceramic spacers as opposed to mica and gold plated strap frame grids.  Electrically, they are the same as 6336A.

You can put those ruggedized tubes to good use bringing your amp along for off-roading, bull riding, theme parks, the options are endless!


----------



## Monsterzero

L0rdGwyn said:


> 6336B is a more ruggedized version of the 6336A, meant to handle prolonged exposure to vibration, appears that it uses ceramic spacers as opposed to mica and gold plated strap frame grids.  Electrically, they are the same as 6336A.
> 
> You can put those ruggedized tubes to good use bringing your amp along for off-roading, bull riding, theme parks, the options are endless!


 Same goes for other tubes, including the Chatham potato masher. I've tried both versions and they sound the same in my system


----------



## L0rdGwyn

Monsterzero said:


> Same goes for other tubes, including the Chatham potato masher. I've tried both versions and they sound the same in my system



B for badass.  Old military designation, or so I'm told.


----------



## bcowen

L0rdGwyn said:


> 6336B is a more ruggedized version of the 6336A, meant to handle prolonged exposure to vibration, appears that it uses ceramic spacers as opposed to mica and gold plated strap frame grids.  Electrically, they are the same as 6336A.
> 
> You can put those ruggedized tubes to good use bringing your amp along for* off-roading, bull riding, theme parks,* the options are endless!


Even playing Marilyn Manson at 105 dB? * Definitely* badass.


----------



## Zachik

L0rdGwyn said:


> You can put those ruggedized tubes to good use bringing your amp along for off-roading, bull riding, theme parks, the options are endless!


Maybe I should talk to Mischa, to ruggedize my upcoming amp...


----------



## mordy

L0rdGwyn said:


> 6336B is a more ruggedized version of the 6336A, meant to handle prolonged exposure to vibration, appears that it uses ceramic spacers as opposed to mica and gold plated strap frame grids.  Electrically, they are the same as 6336A.
> 
> You can put those ruggedized tubes to good use bringing your amp along for off-roading, bull riding, theme parks, the options are endless!


All better options than ballistic missiles…- I think these tubes were designed for such military use. From the spec sheet:
"If cooling is provided to keep bulb temperature within ratings, altitude rating can be extended to 60,000 feet."


----------



## mordy

raindownthunda said:


> Does anyone know if there is a difference between 6336A and 6336B tubes? The graphite plate versions look identical to me. Safe to assume they were all made by the same manufacturer?


It seems that Tung Sol made all of them even though they appear under several different brands.
https://www.antiqueradios.com/forums/viewtopic.php?t=165872


----------



## Zachik

mordy said:


> "If cooling is provided to keep bulb temperature within ratings, altitude rating can be extended to 60,000 feet."


Maybe I should start using my GOTL on airplane's seat tray...


----------



## L0rdGwyn

bcowen said:


> Even playing Marilyn Manson at 105 dB? * Definitely* badass.



The US military of course predicted these harsh operating conditions would come to pass.  For that, you will need the 6336MM, insulated and damped to attenuate such destructive frequencies.


----------



## mordy

raindownthunda said:


> Does anyone know if there is a difference between 6336A and 6336B tubes? The graphite plate versions look identical to me. Safe to assume they were all made by the same manufacturer?


Finally took the plunge and removed my sextet of power tubes and put in a pair of 1972 Cetron 6336B graphite tubes. Drivers are top hat K-Rs 6N7 from 1942. Almost 12A of tubes...




First impression is wide sound stage and punchy bass - quite nice.
The poor 15A voltage regulator is working it's massive heat sinks overtime - glowing red:



- Just kidding; the red hue is from the temperature sensor beam of the infrared thermometer. After 15 minutes the heat sinks are up to almost 60C; the 5A tubes up to 139C; I expect the temperatures to go higher.
The 6N7 runs hot - the KRs are up to 80C.
The amp chassis is 35C with the two fans on.
6336B/6N7 seems to be a very nice combination.
Funny, but the temperatures of the various tubes have dropped a little - is it possible that the type of music influences the temperature of the tubes? More bass content and drums - the tubes work harder?


----------



## mordy

mordy said:


> Finally took the plunge and removed my sextet of power tubes and put in a pair of 1972 Cetron 6336B graphite tubes. Drivers are top hat K-Rs 6N7 from 1942. Almost 12A of tubes...
> 
> First impression is wide sound stage and punchy bass - quite nice.
> The poor 15A voltage regulator is working it's massive heat sinks overtime - glowing red:
> ...


Really enjoying this combination - Cetron 6336B and Ken-Rad 6N7; excellent slam and dynamics.
Tried to capture some tube glow; these pictures are from my iPhone with delayed exposure nightmode:



Another view - it's hot in there!



The camera doesn't lie, but this is how it looks to the eye:



Have fun!
The 6336 tube glow makes up for the lack thereof in the 6N7...


----------



## raindownthunda

Hey Blue Halo owners - have any of you tried EL34
as input tubes? If so curious how you like them? sounds like they would have much more distortion as input tubes than say a 6j5.


----------



## Xcalibur255

I would think an EL34 would be somewhat less linear than a 6J5, but it might be very good for tone.

It's funny I was just thinking before you bumped this thread that's it's been far too quiet in here.  Time for a pic!

I thought the way the evening sunlight was hitting the amp was pretty striking and had to snap this, only to look at it and go "DUST!" after seeing it.  Oh well, it's still a nice shot.


----------



## Xcalibur255

@A2029 I meant to tell you, I finally am able to use the amp with the speakers the amp was intended for and it sounds just as lovely as it does driving headphones.  The gain ended up being a total non-issue, the amp seems very content driving the Omegas.  The room, on the other hand, is a disaster and a half but that's a totally different issue.    I don't understand why people like vaulted ceilings so much, all it does is turn the room into a giant echo chamber.  I didn't get a choice in the matter though so that's how it goes I guess.

The dozen acoustic panels I added to the room helped, but not enough.  It's a work in progress.


----------



## DecentLevi

Xcalibur255 said:


> @A2029 I meant to tell you, I finally am able to use the amp with the speakers the amp was intended for and it sounds just as lovely as it does driving headphones.  The gain ended up being a total non-issue, the amp seems very content driving the Omegas.  The room, on the other hand, is a disaster and a half but that's a totally different issue.    I don't understand why people like vaulted ceilings so much, all it does is turn the room into a giant echo chamber.  I didn't get a choice in the matter though so that's how it goes I guess.
> 
> The dozen acoustic panels I added to the room helped, but not enough.  It's a work in progress.


Probably because most people aren't HiFi audio enthusiasts, and say everything sounds great haha. We have a vaulted ceiling upstairs, and I was hoping maybe acoustic dampening would help. To what extent did it with you? And EL34/ 6J5 are usually not interchangeable. That's interesting - are they with your amp?


----------



## A2029 (Oct 5, 2022)

raindownthunda said:


> Hey Blue Halo owners - have any of you tried EL34
> as input tubes? If so curious how you like them? sounds like they would have much more distortion as input tubes than say a 6j5.



In my limited time testing EL34's via EL34 to 6J5 adapters on BH I found them to be overall slightly warmer/bolder than a 6J5, with a loss of some of the fine technicalities. Soundstage was smaller and details were more obscured by the additional warmth/distortion. Their distortion is over 10X that of a 6J5 in the BH. This was testing with some pretty low end EL34 though (A few different vintages of Electro-harmonic and Svetlana). In the BH+, EL34's could also be run as OTL output tubes (via EL34 to 6AS7 adapters), but the output impedance of the amp jumps up so high that it could do some wonky things to the frequency response of dynamic headphones (boosting certain frequencies and subduing others).


----------



## A2029

Xcalibur255 said:


> @A2029 I meant to tell you, I finally am able to use the amp with the speakers the amp was intended for and it sounds just as lovely as it does driving headphones.  The gain ended up being a total non-issue, the amp seems very content driving the Omegas.  The room, on the other hand, is a disaster and a half but that's a totally different issue.    I don't understand why people like vaulted ceilings so much, all it does is turn the room into a giant echo chamber.  I didn't get a choice in the matter though so that's how it goes I guess.
> 
> The dozen acoustic panels I added to the room helped, but not enough.  It's a work in progress.



Awesome! Good to hear you are finally getting some listening time with the Omega's! The right speaker pairing makes all the difference for low power SET amps


----------



## mordy

Xcalibur255 said:


> I would think an EL34 would be somewhat less linear than a 6J5, but it might be very good for tone.
> 
> It's funny I was just thinking before you bumped this thread that's it's been far too quiet in here.  Time for a pic!
> 
> I thought the way the evening sunlight was hitting the amp was pretty striking and had to snap this, only to look at it and go "DUST!" after seeing it.  Oh well, it's still a nice shot.


It’s really funny - I only see the dust on my amps after I take pictures…


----------



## raindownthunda

A2029 said:


> In the BH+, EL34's could also be run as OTL output tubes (via EL34 to 6AS7 adapters), but the output impedance of the amp jumps up so high that it could do some wonky things to the frequency response of dynamic headphones (boosting certain frequencies and subduing others).


Out of morbid curiosity, what would the output impedance be running 6x EL34 in BH+ power stage?


----------



## maxpudding

raindownthunda said:


> Out of morbid curiosity, what would the output impedance be running 6x EL34 in BH+ power stage?


Interesting…


----------



## A2029

raindownthunda said:


> Out of morbid curiosity, what would the output impedance be running 6x EL34 in BH+ power stage?



Surprisingly not as bad as I had in my mind for some reason (after I looked up the numbers and did the math)  Output impedance would be somewhere around 90-100 ohms for a single EL34 per channel, 45-50 for a pair per channel, and 30-35 ohms for an EL34 triplet per channel.


----------



## leftside

Listening to some bass heavy/warm sounding music this evening. Kind of sounded a little too heavy compared to when I listen with speakers. Switched the amp to use C3g tubes. Freshens everything up nicely.

Haven’t used the C3g tubes for a long time in the “Thunder” amp, but they are a nice option to have.


----------



## MIKELAP

leftside said:


> Listening to some bass heavy/warm sounding music this evening. Kind of sounded a little too heavy compared to when I listen with speakers. Switched the amp to use C3g tubes. Freshens everything up nicely.
> 
> Haven’t used the C3g tubes for a long time in the “Thunder” amp, but they are a nice option to have.



So, are the C3G tubes i sold you years ago still going strong ?


----------



## leftside

MIKELAP said:


> So, are the C3G tubes i sold you years ago still going strong ?


Yeah probably. I have quite a few pairs, and to be honest I'm not sure if I'm using yours in the Glenn 300B and V6 Thunder or not  Great tubes. Definitely have their own sound signature.


----------



## Xcalibur255

C3g tubes last a very long time.  The bigger issue is that sometimes they can become noisy over time.


----------



## whirlwind

Xcalibur255 said:


> C3g tubes last a very long time.  The bigger issue is that sometimes they can become noisy over time.



I remember many years ago, some people were prying off the metal shields because they looked better.
Those shield's are nice to have on those tubes for noise issues.

They are about the most transparent sounding tubes that I have ever heard.  Great tubes.


----------



## Xcalibur255

My opinion back in 2013 was that removing the shield made them sound a little worse.  I actually tried my old pair of 'naked' C3g again recently in the Glenn 45 and my ears say they sound fine now.  That could be more to do with the amplifier than anything though.  I've had various issues with the amp sounding "off" over the years but ever since I moved into this house it's been doing well.  Maybe EFI/RFI or high/low voltage in other places was making the amp unhappy.  The way it would randomly sound fine and then not fine was always a mystery, I'm just glad that it's happy right now.


----------



## Xcalibur255

It's kind of a shame this place is so quiet, but I guess that's to be expected without new owners joining the ranks.  I'm still loving my KT150 amp very much.  Now that the room acoustics have been addressed just enough to make my speakers not sound like arse I've been going through all of my 6J5 again to see what has good synergy with the speakers.  I'm finding that my impressions from demoing these tubes in the GOTL are actually translating over pretty well for the most part.  Best listening session so far has been the Raytheon 4-Pillar 6J5G roundplates, and not by a small margin either.  I'm kind of bummed that these tubes are mismatched in gain enough that it actually causes the stereo center image to "lean" in the direction of the stronger tube, but they sound so good that it pushes that bit of disappointment aside.  Absolutely massive three dimensional soundstage that extends deeply behind the listening position with these tubes in the amp, and it's not just back wall reflection from the room either.  I have a few more pairs to try but it'll be tough to beat this.


----------



## Zachik

Xcalibur255 said:


> It's kind of a shame this place is so quiet, but I guess that's to be expected without new owners joining the ranks.


God Mischa willing, I will join the ranks soon-ish


----------



## cdanguyen08

Zachik said:


> God Mischa willing, I will join the ranks soon-ish


Waiting right there with ya! 🤘🤘


----------



## leftside

whirlwind said:


> I remember many years ago, some people were prying off the metal shields because they looked better.
> Those shield's are nice to have on those tubes for noise issues.
> 
> They are about the most transparent sounding tubes that I have ever heard.  Great tubes.


Yeah Glenn told me that's why he used them in his 300B amp. He wanted to produce the most neutral and transparent sounding amp that he could. 

Ask me which amp I prefer Glenn 300B with C3g vs Thunder V6 with 6J5 or 6SN7 vs Thunder V6 with C3g and you'll probably get a different answer each time you ask  The Thunder V6 with C3g does sound closer to the Glenn 300B with C3g tho, but there are still differences.


----------



## leftside

Xcalibur255 said:


> It's kind of a shame this place is so quiet, but I guess that's to be expected without new owners joining the ranks.


Yeah I have nothing new to add. Apart from saying my two amps from Mischa aren't going anywhere soon.


----------



## maxpudding

According to Dr Mischa, mine will be completed, and ready to ship soon. Can’t wait!


----------



## A2029

Merry Christmas/Happy Holidays everyone!!


----------



## Zachik

A2029 said:


> Merry Christmas/Happy Holidays everyone!!


Same to you Mischa!
For the new year, may 2023 bring you simpler amp builds...


----------

